feat(ebpf):[WIP] add eBPF support (#948)

* feat(kprobe): Add basic kprobe support for x86_64

* feat: add ebpf support (#912)

- 实现bpf()一部分命令，包括几种基本map，相关的helper函数
- 实现部分perf相关的数据结构
- 暂时为文件实现简单mmap
- 实现一个使用kprobe统计syscall 调用次数的ebpf程序

对eBPF支持程度(基本)：

- 简单的eBPF程序(没有指定特殊的Map)
- 使用内核已经实现的Map的eBPF程序
- 可以和kprobe配合使用
- 内核Map相关的接口定义已经实现，添加新的Map较为简单

不支持的功能:
- 区分不同的eBPF程序类型(Network/Cgroup)并限定可调用的helper函数集
- 与内核其它跟踪机制配合(tracepoint)
- 其它helper和Map


todo

- [ ]  修改mmap，需要讨论，因为这个和块缓存层相关
- [x]  添加文档
- [x]  修复可能的错误
- [x] 增加rbpf版本信息

* feat: add /sys/devices/system/cpu/possible file

* feat: add /sys/devices/system/cpu/online

kernel/crates/kprobe/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "kprobe"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+log = "0.4.21"
+
+[target.'cfg(target_arch = "x86_64")'.dependencies]
+yaxpeax-x86 = { version = "2", default-features = false, features = ["fmt"] }
+yaxpeax-arch = { version = "0", default-features = false }

kernel/crates/kprobe/src/arch/loongarch64/mod.rs

@@ -0,0 +1,112 @@
+use alloc::sync::Arc;
+use core::ops::{Deref, DerefMut};
+
+use crate::{KprobeBasic, KprobeBuilder, KprobeOps};
+
+const BRK_KPROBE_BP: u64 = 10;
+const BRK_KPROBE_SSTEPBP: u64 = 11;
+const EBREAK_INST: u32 = 0x002a0000;
+
+#[derive(Debug)]
+pub struct Kprobe {
+    basic: KprobeBasic,
+    point: Arc<LA64KprobePoint>,
+}
+#[derive(Debug)]
+pub struct LA64KprobePoint {
+    addr: usize,
+    inst_tmp: [u8; 8],
+}
+
+impl Deref for Kprobe {
+    type Target = KprobeBasic;
+
+    fn deref(&self) -> &Self::Target {
+        &self.basic
+    }
+}
+
+impl DerefMut for Kprobe {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.basic
+    }
+}
+
+impl Kprobe {
+    pub fn probe_point(&self) -> &Arc<LA64KprobePoint> {
+        &self.point
+    }
+}
+
+impl Drop for LA64KprobePoint {
+    fn drop(&mut self) {
+        let address = self.addr;
+        let inst_tmp_ptr = self.inst_tmp.as_ptr() as usize;
+        let inst_32 = unsafe { core::ptr::read(inst_tmp_ptr as *const u32) };
+        unsafe {
+            core::ptr::write(address as *mut u32, inst_32);
+        }
+        log::trace!(
+            "Kprobe::uninstall: address: {:#x}, old_instruction: {:?}",
+            address,
+            inst_32
+        );
+    }
+}
+
+impl KprobeBuilder {
+    pub fn install(self) -> (Kprobe, Arc<LA64KprobePoint>) {
+        let probe_point = match &self.probe_point {
+            Some(point) => point.clone(),
+            None => self.replace_inst(),
+        };
+        let kprobe = Kprobe {
+            basic: KprobeBasic::from(self),
+            point: probe_point.clone(),
+        };
+        (kprobe, probe_point)
+    }
+    /// # 安装kprobe
+    ///
+    /// 不同的架构下需要保存原指令，然后替换为断点指令
+    fn replace_inst(&self) -> Arc<LA64KprobePoint> {
+        let address = self.symbol_addr + self.offset;
+        let point = LA64KprobePoint {
+            addr: address,
+            inst_tmp: [0u8; 8],
+        };
+        let inst_tmp_ptr = point.inst_tmp.as_ptr() as usize;
+        let inst_32 = unsafe { core::ptr::read(address as *const u32) };
+        unsafe {
+            core::ptr::write(address as *mut u32, EBREAK_INST);
+            // inst_32 :0-32
+            // ebreak  :32-64
+            core::ptr::write(inst_tmp_ptr as *mut u32, inst_32);
+            core::ptr::write((inst_tmp_ptr + 4) as *mut u32, EBREAK_INST);
+        }
+        log::trace!(
+            "Kprobe::install: address: {:#x}, func_name: {:?}, opcode: {:x?}",
+            address,
+            self.symbol,
+            inst_32
+        );
+    }
+}
+
+impl KprobeOps for LA64KprobePoint {
+    fn return_address(&self) -> usize {
+        self.addr + 4
+    }
+
+    fn single_step_address(&self) -> usize {
+        self.inst_tmp.as_ptr() as usize
+    }
+
+    fn debug_address(&self) -> usize {
+        self.inst_tmp.as_ptr() as usize + 4
+    }
+
+    fn break_address(&self) -> usize {
+        self.addr
+    }
+}

kernel/crates/kprobe/src/arch/mod.rs

@@ -0,0 +1,211 @@
+use alloc::boxed::Box;
+use alloc::string::String;
+use alloc::sync::Arc;
+use core::{any::Any, fmt::Debug};
+
+#[cfg(target_arch = "loongarch64")]
+mod loongarch64;
+#[cfg(target_arch = "riscv64")]
+mod rv64;
+#[cfg(target_arch = "x86_64")]
+mod x86;
+
+#[cfg(target_arch = "loongarch64")]
+pub use loongarch64::*;
+#[cfg(target_arch = "riscv64")]
+pub use rv64::*;
+#[cfg(target_arch = "x86_64")]
+pub use x86::*;
+
+#[cfg(target_arch = "x86_64")]
+pub type KprobePoint = X86KprobePoint;
+#[cfg(target_arch = "riscv64")]
+pub type KprobePoint = Rv64KprobePoint;
+#[cfg(target_arch = "loongarch64")]
+pub type KprobePoint = LA64KprobePoint;
+
+pub trait ProbeArgs: Send {
+    /// 用于使用者转换到特定架构下的TrapFrame
+    fn as_any(&self) -> &dyn Any;
+    /// 返回导致break异常的地址
+    fn break_address(&self) -> usize;
+    /// 返回导致单步执行异常的地址
+    fn debug_address(&self) -> usize;
+}
+
+pub trait KprobeOps: Send {
+    /// # 返回探测点的下一条指令地址
+    ///
+    /// 执行流需要回到正常的路径中，在执行完探测点的指令后，需要返回到下一条指令
+    fn return_address(&self) -> usize;
+    /// # 返回单步执行的指令地址
+    ///
+    /// 通常探测点的处的原指令被保存在一个数组当中。根据架构的不同, 在保存的指令后面，可能会填充必要的指令。
+    /// 例如x86架构下支持单步执行的特性， 而其它架构下通常没有，因此我们使用break异常来进行模拟，所以会填充
+    /// 一条断点指令。
+    fn single_step_address(&self) -> usize;
+    /// # 返回单步执行指令触发异常的地址
+    ///
+    /// 其值等于`single_step_address`的值加上探测点指令的长度
+    fn debug_address(&self) -> usize;
+    /// # 返回设置break断点的地址
+    ///
+    /// 其值与探测点地址相等
+    fn break_address(&self) -> usize;
+}
+
+struct ProbeHandler {
+    func: fn(&dyn ProbeArgs),
+}
+
+impl ProbeHandler {
+    pub fn new(func: fn(&dyn ProbeArgs)) -> Self {
+        ProbeHandler { func }
+    }
+    /// 调用探测点处理函数
+    pub fn call(&self, trap_frame: &dyn ProbeArgs) {
+        (self.func)(trap_frame);
+    }
+}
+
+pub struct KprobeBuilder {
+    symbol: Option<String>,
+    symbol_addr: usize,
+    offset: usize,
+    pre_handler: ProbeHandler,
+    post_handler: ProbeHandler,
+    fault_handler: Option<ProbeHandler>,
+    event_callback: Option<Box<dyn CallBackFunc>>,
+    probe_point: Option<Arc<KprobePoint>>,
+    enable: bool,
+}
+
+pub trait EventCallback: Send {
+    fn call(&self, trap_frame: &dyn ProbeArgs);
+}
+
+impl KprobeBuilder {
+    pub fn new(
+        symbol: Option<String>,
+        symbol_addr: usize,
+        offset: usize,
+        pre_handler: fn(&dyn ProbeArgs),
+        post_handler: fn(&dyn ProbeArgs),
+        enable: bool,
+    ) -> Self {
+        KprobeBuilder {
+            symbol,
+            symbol_addr,
+            offset,
+            pre_handler: ProbeHandler::new(pre_handler),
+            post_handler: ProbeHandler::new(post_handler),
+            event_callback: None,
+            fault_handler: None,
+            probe_point: None,
+            enable,
+        }
+    }
+
+    pub fn with_fault_handler(mut self, func: fn(&dyn ProbeArgs)) -> Self {
+        self.fault_handler = Some(ProbeHandler::new(func));
+        self
+    }
+
+    pub fn with_probe_point(mut self, point: Arc<KprobePoint>) -> Self {
+        self.probe_point = Some(point);
+        self
+    }
+
+    pub fn with_event_callback(mut self, event_callback: Box<dyn CallBackFunc>) -> Self {
+        self.event_callback = Some(event_callback);
+        self
+    }
+
+    /// 获取探测点的地址
+    ///
+    /// 探测点的地址 == break指令的地址
+    pub fn probe_addr(&self) -> usize {
+        self.symbol_addr + self.offset
+    }
+}
+
+pub struct KprobeBasic {
+    symbol: Option<String>,
+    symbol_addr: usize,
+    offset: usize,
+    pre_handler: ProbeHandler,
+    post_handler: ProbeHandler,
+    fault_handler: ProbeHandler,
+    event_callback: Option<Box<dyn CallBackFunc>>,
+    enable: bool,
+}
+
+pub trait CallBackFunc: Send + Sync {
+    fn call(&self, trap_frame: &dyn ProbeArgs);
+}
+
+impl Debug for KprobeBasic {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        f.debug_struct("Kprobe")
+            .field("symbol", &self.symbol)
+            .field("symbol_addr", &self.symbol_addr)
+            .field("offset", &self.offset)
+            .finish()
+    }
+}
+
+impl KprobeBasic {
+    pub fn call_pre_handler(&self, trap_frame: &dyn ProbeArgs) {
+        self.pre_handler.call(trap_frame);
+    }
+
+    pub fn call_post_handler(&self, trap_frame: &dyn ProbeArgs) {
+        self.post_handler.call(trap_frame);
+    }
+
+    pub fn call_fault_handler(&self, trap_frame: &dyn ProbeArgs) {
+        self.fault_handler.call(trap_frame);
+    }
+
+    pub fn call_event_callback(&self, trap_frame: &dyn ProbeArgs) {
+        if let Some(ref call_back) = self.event_callback {
+            call_back.call(trap_frame);
+        }
+    }
+
+    pub fn update_event_callback(&mut self, callback: Box<dyn CallBackFunc>) {
+        self.event_callback = Some(callback);
+    }
+
+    pub fn disable(&mut self) {
+        self.enable = false;
+    }
+
+    pub fn enable(&mut self) {
+        self.enable = true;
+    }
+
+    pub fn is_enabled(&self) -> bool {
+        self.enable
+    }
+    /// 返回探测点的函数名称
+    pub fn symbol(&self) -> Option<&str> {
+        self.symbol.as_deref()
+    }
+}
+
+impl From<KprobeBuilder> for KprobeBasic {
+    fn from(value: KprobeBuilder) -> Self {
+        let fault_handler = value.fault_handler.unwrap_or(ProbeHandler::new(|_| {}));
+        KprobeBasic {
+            symbol: value.symbol,
+            symbol_addr: value.symbol_addr,
+            offset: value.offset,
+            pre_handler: value.pre_handler,
+            post_handler: value.post_handler,
+            event_callback: value.event_callback,
+            fault_handler,
+            enable: value.enable,
+        }
+    }
+}

kernel/crates/kprobe/src/arch/rv64/mod.rs

@@ -0,0 +1,157 @@
+use alloc::sync::Arc;
+use core::{
+    arch::riscv64::sfence_vma_all,
+    fmt::Debug,
+    ops::{Deref, DerefMut},
+};
+
+use crate::{KprobeBasic, KprobeBuilder, KprobeOps};
+const EBREAK_INST: u32 = 0x00100073; // ebreak
+const C_EBREAK_INST: u32 = 0x9002; // c.ebreak
+const INSN_LENGTH_MASK: u16 = 0x3;
+const INSN_LENGTH_32: u16 = 0x3;
+
+#[derive(Debug)]
+pub struct Kprobe {
+    basic: KprobeBasic,
+    point: Arc<Rv64KprobePoint>,
+}
+
+#[derive(Debug)]
+enum OpcodeTy {
+    Inst16(u16),
+    Inst32(u32),
+}
+#[derive(Debug)]
+pub struct Rv64KprobePoint {
+    addr: usize,
+    old_instruction: OpcodeTy,
+    inst_tmp: [u8; 8],
+}
+
+impl Deref for Kprobe {
+    type Target = KprobeBasic;
+
+    fn deref(&self) -> &Self::Target {
+        &self.basic
+    }
+}
+
+impl DerefMut for Kprobe {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.basic
+    }
+}
+
+impl Kprobe {
+    pub fn probe_point(&self) -> &Arc<Rv64KprobePoint> {
+        &self.point
+    }
+}
+
+impl Drop for Rv64KprobePoint {
+    fn drop(&mut self) {
+        let address = self.addr;
+        match self.old_instruction {
+            OpcodeTy::Inst16(inst_16) => unsafe {
+                core::ptr::write(address as *mut u16, inst_16);
+            },
+            OpcodeTy::Inst32(inst_32) => unsafe {
+                core::ptr::write(address as *mut u32, inst_32);
+            },
+        }
+        unsafe {
+            sfence_vma_all();
+        }
+        log::trace!(
+            "Kprobe::uninstall: address: {:#x}, old_instruction: {:?}",
+            address,
+            self.old_instruction
+        );
+    }
+}
+
+impl KprobeBuilder {
+    pub fn install(self) -> (Kprobe, Arc<Rv64KprobePoint>) {
+        let probe_point = match &self.probe_point {
+            Some(point) => point.clone(),
+            None => self.replace_inst(),
+        };
+        let kprobe = Kprobe {
+            basic: KprobeBasic::from(self),
+            point: probe_point.clone(),
+        };
+        (kprobe, probe_point)
+    }
+    /// # 安装kprobe
+    ///
+    /// 不同的架构下需要保存原指令，然后替换为断点指令
+    fn replace_inst(&self) -> Arc<Rv64KprobePoint> {
+        let address = self.symbol_addr + self.offset;
+        let inst_16 = unsafe { core::ptr::read(address as *const u16) };
+        // See https://elixir.bootlin.com/linux/v6.10.2/source/arch/riscv/kernel/probes/kprobes.c#L68
+        let is_inst_16 = if (inst_16 & INSN_LENGTH_MASK) == INSN_LENGTH_32 {
+            false
+        } else {
+            true
+        };
+        let mut point = Rv64KprobePoint {
+            old_instruction: OpcodeTy::Inst16(0),
+            inst_tmp: [0; 8],
+            addr: address,
+        };
+        let inst_tmp_ptr = point.inst_tmp.as_ptr() as usize;
+        if is_inst_16 {
+            point.old_instruction = OpcodeTy::Inst16(inst_16);
+            unsafe {
+                core::ptr::write(address as *mut u16, C_EBREAK_INST as u16);
+                // inst_16 :0-16
+                // c.ebreak:16-32
+                core::ptr::write(inst_tmp_ptr as *mut u16, inst_16);
+                core::ptr::write((inst_tmp_ptr + 2) as *mut u16, C_EBREAK_INST as u16);
+            }
+        } else {
+            let inst_32 = unsafe { core::ptr::read(address as *const u32) };
+            point.old_instruction = OpcodeTy::Inst32(inst_32);
+            unsafe {
+                core::ptr::write(address as *mut u32, EBREAK_INST);
+                // inst_32 :0-32
+                // ebreak  :32-64
+                core::ptr::write(inst_tmp_ptr as *mut u32, inst_32);
+                core::ptr::write((inst_tmp_ptr + 4) as *mut u32, EBREAK_INST);
+            }
+        }
+        unsafe {
+            sfence_vma_all();
+        }
+        log::trace!(
+            "Kprobe::install: address: {:#x}, func_name: {:?}, opcode: {:x?}",
+            address,
+            self.symbol,
+            point.old_instruction
+        );
+        Arc::new(point)
+    }
+}
+
+impl KprobeOps for Rv64KprobePoint {
+    fn return_address(&self) -> usize {
+        let address = self.addr;
+        match self.old_instruction {
+            OpcodeTy::Inst16(_) => address + 2,
+            OpcodeTy::Inst32(_) => address + 4,
+        }
+    }
+    fn single_step_address(&self) -> usize {
+        self.inst_tmp.as_ptr() as usize
+    }
+    fn debug_address(&self) -> usize {
+        match self.old_instruction {
+            OpcodeTy::Inst16(_) => self.inst_tmp.as_ptr() as usize + 2,
+            OpcodeTy::Inst32(_) => self.inst_tmp.as_ptr() as usize + 4,
+        }
+    }
+    fn break_address(&self) -> usize {
+        self.addr
+    }
+}

kernel/crates/kprobe/src/arch/x86/mod.rs

@@ -0,0 +1,135 @@
+use crate::{KprobeBasic, KprobeBuilder, KprobeOps};
+use alloc::string::ToString;
+use alloc::sync::Arc;
+use core::{
+    fmt::Debug,
+    ops::{Deref, DerefMut},
+};
+use yaxpeax_arch::LengthedInstruction;
+
+const EBREAK_INST: u8 = 0xcc; // x86_64: 0xcc
+const MAX_INSTRUCTION_SIZE: usize = 15; // x86_64 max instruction length
+
+pub struct Kprobe {
+    basic: KprobeBasic,
+    point: Arc<X86KprobePoint>,
+}
+
+#[derive(Debug)]
+pub struct X86KprobePoint {
+    addr: usize,
+    old_instruction: [u8; MAX_INSTRUCTION_SIZE],
+    old_instruction_len: usize,
+}
+
+impl Drop for X86KprobePoint {
+    fn drop(&mut self) {
+        let address = self.addr;
+        unsafe {
+            core::ptr::copy(
+                self.old_instruction.as_ptr(),
+                address as *mut u8,
+                self.old_instruction_len,
+            );
+            core::arch::x86_64::_mm_mfence();
+        }
+        let decoder = yaxpeax_x86::amd64::InstDecoder::default();
+        let inst = decoder.decode_slice(&self.old_instruction).unwrap();
+        log::trace!(
+            "Kprobe::uninstall: address: {:#x}, old_instruction: {:?}",
+            address,
+            inst.to_string()
+        );
+    }
+}
+
+impl Debug for Kprobe {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        f.debug_struct("Kprobe")
+            .field("basic", &self.basic)
+            .field("point", &self.point)
+            .finish()
+    }
+}
+
+impl Deref for Kprobe {
+    type Target = KprobeBasic;
+
+    fn deref(&self) -> &Self::Target {
+        &self.basic
+    }
+}
+
+impl DerefMut for Kprobe {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.basic
+    }
+}
+
+impl KprobeBuilder {
+    pub fn install(self) -> (Kprobe, Arc<X86KprobePoint>) {
+        let probe_point = match &self.probe_point {
+            Some(point) => point.clone(),
+            None => self.replace_inst(),
+        };
+        let kprobe = Kprobe {
+            basic: KprobeBasic::from(self),
+            point: probe_point.clone(),
+        };
+        (kprobe, probe_point)
+    }
+    /// # 安装kprobe
+    ///
+    /// 不同的架构下需要保存原指令，然后替换为断点指令
+    fn replace_inst(&self) -> Arc<X86KprobePoint> {
+        let address = self.symbol_addr + self.offset;
+        let mut inst_tmp = [0u8; MAX_INSTRUCTION_SIZE];
+        unsafe {
+            core::ptr::copy(
+                address as *const u8,
+                inst_tmp.as_mut_ptr(),
+                MAX_INSTRUCTION_SIZE,
+            );
+        }
+        let decoder = yaxpeax_x86::amd64::InstDecoder::default();
+        let inst = decoder.decode_slice(&inst_tmp).unwrap();
+        let len = inst.len().to_const();
+        log::trace!("inst: {:?}, len: {:?}", inst.to_string(), len);
+        let point = Arc::new(X86KprobePoint {
+            addr: address,
+            old_instruction: inst_tmp,
+            old_instruction_len: len as usize,
+        });
+        unsafe {
+            core::ptr::write_volatile(address as *mut u8, EBREAK_INST);
+            core::arch::x86_64::_mm_mfence();
+        }
+        log::trace!(
+            "Kprobe::install: address: {:#x}, func_name: {:?}",
+            address,
+            self.symbol
+        );
+        point
+    }
+}
+
+impl Kprobe {
+    pub fn probe_point(&self) -> &Arc<X86KprobePoint> {
+        &self.point
+    }
+}
+
+impl KprobeOps for X86KprobePoint {
+    fn return_address(&self) -> usize {
+        self.addr + self.old_instruction_len
+    }
+    fn single_step_address(&self) -> usize {
+        self.old_instruction.as_ptr() as usize
+    }
+    fn debug_address(&self) -> usize {
+        self.old_instruction.as_ptr() as usize + self.old_instruction_len
+    }
+    fn break_address(&self) -> usize {
+        self.addr
+    }
+}

kernel/crates/kprobe/src/lib.rs

@@ -0,0 +1,7 @@
+#![cfg_attr(target_arch = "riscv64", feature(riscv_ext_intrinsics))]
+#![no_std]
+extern crate alloc;
+
+mod arch;
+
+pub use arch::*;

kernel/crates/rbpf/.appveyor.yml

@@ -0,0 +1,21 @@
+version: 1.0.{build}
+branches:
+  only:
+    - main
+os:
+  - Visual Studio 2015
+clone_depth: 1
+configuration:
+  - Debug
+platform:
+  - x64
+environment:
+  matrix:
+    - TOOLCHAIN_VERSION: 14.0
+      RUST: 1.76.0
+    - TOOLCHAIN_VERSION: 14.0
+      RUST: beta
+    - TOOLCHAIN_VERSION: 14.0
+      RUST: nightly
+
+build_script: mk/appveyor.bat

kernel/crates/rbpf/.gitignore

@@ -0,0 +1,2 @@
+target
+Cargo.lock

kernel/crates/rbpf/Cargo.toml

@@ -0,0 +1,78 @@
+[package]
+
+# Project metadata
+name = "rbpf"
+version = "0.2.0"
+authors = ["Quentin <quentin@isovalent.com>"]
+
+# Additional metadata for packaging
+description = "Virtual machine and JIT compiler for eBPF programs"
+repository = "https://github.com/qmonnet/rbpf"
+readme = "README.md"
+keywords = ["BPF", "eBPF", "interpreter", "JIT", "filtering"]
+license = "Apache-2.0/MIT"
+edition = "2021"
+
+# Packaging directives
+include = [
+    "src/**",
+    "examples/**",
+    "tests/**",
+    "bench/**",
+    "LICENSE*",
+    "Cargo.toml",
+]
+
+[dependencies]
+
+# Default features (std) are disabled so that the dependencies don't pull in the
+# standard library when the crate is compiled for no_std
+byteorder = { version = "1.2", default-features = false }
+log = {version = "0.4.21", default-features = false }
+combine = { version = "4.6", default-features = false }
+
+# Optional Dependencies when using the standard library
+libc = { version = "0.2", optional = true }
+time = { version = "0.2", optional = true }
+
+# Optional Dependencies for the CraneLift JIT
+cranelift-codegen = { version = "0.99", optional = true }
+cranelift-frontend = { version = "0.99", optional = true }
+cranelift-jit = { version = "0.99", optional = true }
+cranelift-native = { version = "0.99", optional = true }
+cranelift-module = { version = "0.99", optional = true }
+
+[dev-dependencies]
+
+elf = "0.0.10"
+json = "0.11"
+hex = "0.4.3"
+
+[features]
+#default = ["std", "user", "cranelift"]
+cargo-clippy = []
+std = ["dep:time", "dep:libc", "combine/std"]
+cranelift = [
+    "dep:cranelift-codegen",
+    "dep:cranelift-frontend",
+    "dep:cranelift-jit",
+    "dep:cranelift-native",
+    "dep:cranelift-module",
+]
+user = []
+
+# Examples that depend on the standard library should be disabled when
+# testing the `no_std` configuration.
+[[example]]
+name = "disassemble"
+required-features = ["std"]
+
+[[example]]
+name = "uptime"
+required-features = ["std"]
+
+[[example]]
+name = "to_json"
+
+[[example]]
+name = "rbpf_plugin"

kernel/crates/rbpf/LICENSE-APACHE

@@ -0,0 +1,202 @@
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kernel/crates/rbpf/LICENSE-MIT

@@ -0,0 +1,25 @@
+Copyright (c) 2016 6WIND S.A.
+
+Permission is hereby granted, free of charge, to any
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+
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+of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
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+TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
+SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.

kernel/crates/rbpf/README.md

@@ -0,0 +1,743 @@
+# rbpf
+
+<picture>
+  <source media="(prefers-color-scheme: dark)" srcset="misc/rbpf_256_border.png">
+  <img src="misc/rbpf_256.png">
+</picture>
+
+Rust (user-space) virtual machine for eBPF
+
+[![Build Status](https://github.com/qmonnet/rbpf/actions/workflows/test.yaml/badge.svg)](https://github.com/qmonnet/rbpf/actions/workflows/test.yaml)
+[![Build status](https://ci.appveyor.com/api/projects/status/ia74coeuhxtrcvsk/branch/main?svg=true)](https://ci.appveyor.com/project/qmonnet/rbpf/branch/main)
+[![Coverage Status](https://coveralls.io/repos/github/qmonnet/rbpf/badge.svg?branch=main)](https://coveralls.io/github/qmonnet/rbpf?branch=main)
+[![Crates.io](https://img.shields.io/crates/v/rbpf.svg)](https://crates.io/crates/rbpf)
+
+* [Description](#description)
+* [Link to the crate](#link-to-the-crate)
+* [API](#api)
+* [Example uses](#example-uses)
+* [Building eBPF programs](#building-ebpf-programs)
+* [Build Features](#build-features)
+* [Feedback welcome!](#feedback-welcome)
+* [Questions / Answers](#questions--answers)
+* [Caveats](#caveats)
+* [_To do_ list](#to-do-list)
+* [License](#license)
+* [Inspired by](#inspired-by)
+* [Other resources](#other-resources)
+
+## Description
+
+This crate contains a virtual machine for eBPF program execution. BPF, as in
+_Berkeley Packet Filter_, is an assembly-like language initially developed for
+BSD systems, in order to filter packets in the kernel with tools such as
+tcpdump so as to avoid useless copies to user-space. It was ported to Linux,
+where it evolved into eBPF (_extended_ BPF), a faster version with more
+features. While BPF programs are originally intended to run in the kernel, the
+virtual machine of this crate enables running it in user-space applications;
+it contains an interpreter, an x86_64 JIT-compiler for eBPF programs, as well as
+a disassembler.
+
+It is based on Rich Lane's [uBPF software](https://github.com/iovisor/ubpf/),
+which does nearly the same, but is written in C.
+
+The crate is supposed to compile and run on Linux, MacOS X, and Windows,
+although the JIT-compiler does not work with Windows at this time.
+
+## Link to the crate
+
+This crate is available from [crates.io](https://crates.io/crates/rbpf), so it
+should work out of the box by adding it as a dependency in your `Cargo.toml`
+file:
+
+```toml
+[dependencies]
+rbpf = "0.2.0"
+```
+
+You can also use the development version from this GitHub repository. This
+should be as simple as putting this inside your `Cargo.toml`:
+
+```toml
+[dependencies]
+rbpf = { git = "https://github.com/qmonnet/rbpf" }
+```
+
+Of course, if you prefer, you can clone it locally, possibly hack the crate,
+and then indicate the path of your local version in `Cargo.toml`:
+
+```toml
+[dependencies]
+rbpf = { path = "path/to/rbpf" }
+```
+
+Then indicate in your source code that you want to use the crate:
+
+```rust,ignore
+extern crate rbpf;
+```
+
+## API
+
+The API is pretty well documented inside the source code. You should also be
+able to access [an online version of the documentation from
+here](https://docs.rs/rbpf/), automatically generated from the
+[crates.io](https://crates.io/crates/rbpf) version (may not be up-to-date with
+the main branch). [Examples](../../tree/main/examples) and [unit
+tests](../../tree/main/tests) should also prove helpful. Here is a summary of
+how to use the crate.
+
+Here are the steps to follow to run an eBPF program with rbpf:
+
+1. Create a virtual machine. There are several kinds of machines, we will come
+   back on this later. When creating the VM, pass the eBPF program as an
+   argument to the constructor.
+2. If you want to use some helper functions, register them into the virtual
+   machine.
+3. If you want a JIT-compiled program, compile it.
+4. Execute your program: either run the interpreter or call the JIT-compiled
+   function.
+
+eBPF has been initially designed to filter packets (now it has some other hooks
+in the Linux kernel, such as kprobes, but this is not covered by rbpf). As a
+consequence, most of the load and store instructions of the program are
+performed on a memory area representing the packet data. However, in the Linux
+kernel, the eBPF program does not immediately access this data area: initially,
+it has access to a C `struct sk_buff` instead, which is a buffer containing
+metadata about the packet—including memory addresses of the beginning and of
+the end of the packet data area. So the program first loads those pointers from
+the `sk_buff`, and then can access the packet data.
+
+This behavior can be replicated with rbpf, but it is not mandatory. For this
+reason, we have several structs representing different kinds of virtual
+machines:
+
+* `struct EbpfVmMbuffer` mimics the kernel. When the program is run, the
+  address provided to its first eBPF register will be the address of a metadata
+  buffer provided by the user, and that is expected to contain pointers to the
+  start and the end of the packet data memory area.
+
+* `struct EbpfVmFixedMbuff` has one purpose: enabling the execution of programs
+  created to be compatible with the kernel, while saving the effort to manually
+  handle the metadata buffer for the user. In fact, this struct has a static
+  internal buffer that is passed to the program. The user has to indicate the
+  offset values at which the eBPF program expects to find the start and the end
+  of packet data in the buffer. On calling the function that runs the program
+  (JITted or not), the struct automatically updates the addresses in this
+  static buffer, at the appointed offsets, for the start and the end of the
+  packet data the program is called upon.
+
+* `struct EbpfVmRaw` is for programs that want to run directly on packet data.
+  No metadata buffer is involved, the eBPF program directly receives the
+  address of the packet data in its first register. This is the behavior of
+  uBPF.
+
+* `struct EbpfVmNoData` does not take any data. The eBPF program takes no
+  argument whatsoever and its return value is deterministic. Not so sure there
+  is a valid use case for that, but if nothing else, this is very useful for
+  unit tests.
+
+All these structs implement the same public functions:
+
+```rust,ignore
+// called with EbpfVmMbuff:: prefix
+pub fn new(prog: &'a [u8]) -> Result<EbpfVmMbuff<'a>, Error>
+
+// called with EbpfVmFixedMbuff:: prefix
+pub fn new(prog: &'a [u8],
+           data_offset: usize,
+           data_end_offset: usize) -> Result<EbpfVmFixedMbuff<'a>, Error>
+
+// called with EbpfVmRaw:: prefix
+pub fn new(prog: &'a [u8]) -> Result<EbpfVmRaw<'a>, Error>
+
+// called with EbpfVmNoData:: prefix
+pub fn new(prog: &'a [u8]) -> Result<EbpfVmNoData<'a>, Error>
+```
+
+This is used to create a new instance of a VM. The return type is dependent of
+the struct from which the function is called. For instance,
+`rbpf::EbpfVmRaw::new(Some(my_program))` would return an instance of `struct
+rbpf::EbpfVmRaw` (wrapped in a `Result`). When a program is loaded, it is
+checked with a very simple verifier (nothing close to the one for Linux
+kernel). Users are also able to replace it with a custom verifier.
+
+For `struct EbpfVmFixedMbuff`, two additional arguments must be passed to the
+constructor: `data_offset` and `data_end_offset`. They are the offset (byte
+number) at which the pointers to the beginning and to the end, respectively, of
+the memory area of packet data are to be stored in the internal metadata buffer
+each time the program is executed. Other structs do not use this mechanism and
+do not need those offsets.
+
+```rust,ignore
+// for struct EbpfVmMbuff, struct EbpfVmRaw and struct EbpfVmRawData
+pub fn set_program(&mut self, prog: &'a [u8]) -> Result<(), Error>
+
+// for struct EbpfVmFixedMbuff
+pub fn set_program(&mut self, prog: &'a [u8],
+                data_offset: usize,
+                data_end_offset: usize) -> Result<(), Error>
+```
+
+You can use for example `my_vm.set_program(my_program);` to change the loaded
+program after the VM instance creation. This program is checked with the
+verifier attached to the VM. The verifying function of the VM can be changed at
+any moment.
+
+```rust,ignore
+pub type Verifier = fn(prog: &[u8]) -> Result<(), Error>;
+
+pub fn set_verifier(&mut self,
+                    verifier: Verifier) -> Result<(), Error>
+```
+
+Note that if a program has already been loaded into the VM, setting a new
+verifier also immediately runs it on the loaded program. However, the verifier
+is not run if no program has been loaded (if `None` was passed to the `new()`
+method when creating the VM).
+
+```rust,ignore
+pub type Helper = fn (u64, u64, u64, u64, u64) -> u64;
+
+pub fn register_helper(&mut self,
+                       key: u32,
+                       function: Helper) -> Result<(), Error>
+```
+
+This function is used to register a helper function. The VM stores its
+registers in a hashmap, so the key can be any `u32` value you want. It may be
+useful for programs that should be compatible with the Linux kernel and
+therefore must use specific helper numbers.
+
+```rust,ignore
+// for struct EbpfVmMbuff
+pub fn execute_program(&self,
+                 mem: &'a mut [u8],
+                 mbuff: &'a mut [u8]) -> Result<(u64), Error>
+
+// for struct EbpfVmFixedMbuff and struct EbpfVmRaw
+pub fn execute_program(&self,
+                 mem: &'a mut [u8]) -> Result<(u64), Error>
+
+// for struct EbpfVmNoData
+pub fn execute_program(&self) -> Result<(u64), Error>
+```
+
+Interprets the loaded program. The function takes a reference to the packet
+data and the metadata buffer, or only to the packet data, or nothing at all,
+depending on the kind of the VM used. The value returned is the result of the
+eBPF program.
+
+```rust,ignore
+pub fn jit_compile(&mut self) -> Result<(), Error>
+```
+
+JIT-compile the loaded program, for x86_64 architecture. If the program is to
+use helper functions, they must be registered into the VM before this function
+is called. The generated assembly function is internally stored in the VM.
+
+```rust,ignore
+// for struct EbpfVmMbuff
+pub unsafe fn execute_program_jit(&self, mem: &'a mut [u8],
+                            mbuff: &'a mut [u8]) -> Result<(u64), Error>
+
+// for struct EbpfVmFixedMbuff and struct EbpfVmRaw
+pub unsafe fn execute_program_jit(&self, mem: &'a mut [u8]) -> Result<(u64), Error>
+
+// for struct EbpfVmNoData
+pub unsafe fn execute_program_jit(&self) -> Result<(u64), Error>
+```
+
+Calls the JIT-compiled program. The arguments to provide are the same as for
+`execute_program()`, again depending on the kind of VM that is used. The result of
+the JIT-compiled program should be the same as with the interpreter, but it
+should run faster. Note that if errors occur during the program execution, the
+JIT-compiled version does not handle it as well as the interpreter, and the
+program may crash. For this reason, the functions are marked as `unsafe`.
+
+## Example uses
+
+### Simple example
+
+This comes from the unit test `test_vm_add`.
+
+```rust
+extern crate rbpf;
+
+fn main() {
+
+    // This is the eBPF program, in the form of bytecode instructions.
+    let prog = &[
+        0xb4, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov32 r0, 0
+        0xb4, 0x01, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, // mov32 r1, 2
+        0x04, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, // add32 r0, 1
+        0x0c, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // add32 r0, r1
+        0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00  // exit
+    ];
+
+    // Instantiate a struct EbpfVmNoData. This is an eBPF VM for programs that
+    // takes no packet data in argument.
+    // The eBPF program is passed to the constructor.
+    let vm = rbpf::EbpfVmNoData::new(Some(prog)).unwrap();
+
+    // Execute (interpret) the program. No argument required for this VM.
+    assert_eq!(vm.execute_program().unwrap(), 0x3);
+}
+```
+
+### With JIT, on packet data
+
+This comes from the unit test `test_jit_ldxh`.
+
+```rust
+extern crate rbpf;
+
+fn main() {
+    let prog = &[
+        0x71, 0x10, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, // ldxh r0, [r1+2]
+        0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00  // exit
+    ];
+
+    // Let's use some data.
+    let mem = &mut [
+        0xaa, 0xbb, 0x11, 0xcc, 0xdd
+    ];
+
+    // This is an eBPF VM for programs reading from a given memory area (it
+    // directly reads from packet data)
+    let mut vm = rbpf::EbpfVmRaw::new(Some(prog)).unwrap();
+
+    #[cfg(any(windows, not(feature = "std")))] {
+        assert_eq!(vm.execute_program(mem).unwrap(), 0x11);
+    }
+    #[cfg(all(not(windows), feature = "std"))] {
+        // This time we JIT-compile the program.
+        vm.jit_compile().unwrap();
+
+        // Then we execute it. For this kind of VM, a reference to the packet
+        // data must be passed to the function that executes the program.
+        unsafe { assert_eq!(vm.execute_program_jit(mem).unwrap(), 0x11); }
+    }
+}
+```
+### Using a metadata buffer
+
+This comes from the unit test `test_jit_mbuff` and derives from the unit test
+`test_jit_ldxh`.
+
+```rust
+extern crate rbpf;
+
+fn main() {
+    let prog = &[
+        // Load mem from mbuff at offset 8 into R1
+        0x79, 0x11, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00,
+        // ldhx r1[2], r0
+        0x69, 0x10, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+    ];
+    let mem = &mut [
+        0xaa, 0xbb, 0x11, 0x22, 0xcc, 0xdd
+    ];
+
+    // Just for the example we create our metadata buffer from scratch, and
+    // we store the pointers to packet data start and end in it.
+    let mut mbuff = &mut [0u8; 32];
+    unsafe {
+        let mut data     = mbuff.as_ptr().offset(8)  as *mut u64;
+        let mut data_end = mbuff.as_ptr().offset(24) as *mut u64;
+        *data     = mem.as_ptr() as u64;
+        *data_end = mem.as_ptr() as u64 + mem.len() as u64;
+    }
+
+    // This eBPF VM is for program that use a metadata buffer.
+    let mut vm = rbpf::EbpfVmMbuff::new(Some(prog)).unwrap();
+
+    #[cfg(any(windows, not(feature = "std")))] {
+        assert_eq!(vm.execute_program(mem, mbuff).unwrap(), 0x2211);
+    }
+    #[cfg(all(not(windows), feature = "std"))] {
+        // Here again we JIT-compile the program.
+        vm.jit_compile().unwrap();
+
+        // Here we must provide both a reference to the packet data, and to the
+        // metadata buffer we use.
+        unsafe {
+            assert_eq!(vm.execute_program_jit(mem, mbuff).unwrap(), 0x2211);
+        }
+    }
+}
+```
+
+### Loading code from an object file; and using a virtual metadata buffer
+
+This comes from unit test `test_vm_block_port`.
+
+This example requires the following additional crates, you may have to add them
+to your `Cargo.toml` file.
+
+```toml
+[dependencies]
+rbpf = "0.2.0"
+elf = "0.0.10"
+```
+
+It also uses a kind of VM that uses an internal buffer used to simulate the
+`sk_buff` used by eBPF programs in the kernel, without having to manually
+create a new buffer for each packet. It may be useful for programs compiled for
+the kernel and that assumes the data they receive is a `sk_buff` pointing to
+the packet data start and end addresses. So here we just provide the offsets at
+which the eBPF program expects to find those pointers, and the VM handles the
+buffer update so that we only have to provide a reference to the packet data
+for each run of the program.
+
+```rust
+extern crate elf;
+use std::path::PathBuf;
+
+extern crate rbpf;
+use rbpf::helpers;
+
+fn main() {
+    // Load a program from an ELF file, e.g. compiled from C to eBPF with
+    // clang/LLVM. Some minor modification to the bytecode may be required.
+    let filename = "examples/load_elf__block_a_port.elf";
+
+    let path = PathBuf::from(filename);
+    let file = match elf::File::open_path(&path) {
+        Ok(f) => f,
+        Err(e) => panic!("Error: {:?}", e),
+    };
+
+    // Here we assume the eBPF program is in the ELF section called
+    // ".classifier".
+    let text_scn = match file.get_section(".classifier") {
+        Some(s) => s,
+        None => panic!("Failed to look up .classifier section"),
+    };
+
+    let prog = &text_scn.data;
+
+    // This is our data: a real packet, starting with Ethernet header
+    let packet = &mut [
+        0x01, 0x23, 0x45, 0x67, 0x89, 0xab,
+        0xfe, 0xdc, 0xba, 0x98, 0x76, 0x54,
+        0x08, 0x00,             // ethertype
+        0x45, 0x00, 0x00, 0x3b, // start ip_hdr
+        0xa6, 0xab, 0x40, 0x00,
+        0x40, 0x06, 0x96, 0x0f,
+        0x7f, 0x00, 0x00, 0x01,
+        0x7f, 0x00, 0x00, 0x01,
+        0x99, 0x99, 0xc6, 0xcc, // start tcp_hdr
+        0xd1, 0xe5, 0xc4, 0x9d,
+        0xd4, 0x30, 0xb5, 0xd2,
+        0x80, 0x18, 0x01, 0x56,
+        0xfe, 0x2f, 0x00, 0x00,
+        0x01, 0x01, 0x08, 0x0a, // start data
+        0x00, 0x23, 0x75, 0x89,
+        0x00, 0x23, 0x63, 0x2d,
+        0x71, 0x64, 0x66, 0x73,
+        0x64, 0x66, 0x0a
+    ];
+
+    // This is an eBPF VM for programs using a virtual metadata buffer, similar
+    // to the sk_buff that eBPF programs use with tc and in Linux kernel.
+    // We must provide the offsets at which the pointers to packet data start
+    // and end must be stored: these are the offsets at which the program will
+    // load the packet data from the metadata buffer.
+    let mut vm = rbpf::EbpfVmFixedMbuff::new(Some(prog), 0x40, 0x50).unwrap();
+
+    // We register a helper function, that can be called by the program, into
+    // the VM. The `bpf_trace_printf` is only available when we have access to
+    // the standard library.
+    #[cfg(feature = "std")] {
+        vm.register_helper(helpers::BPF_TRACE_PRINTK_IDX,
+                           helpers::bpf_trace_printf).unwrap();
+    }
+
+    // This kind of VM takes a reference to the packet data, but does not need
+    // any reference to the metadata buffer: a fixed buffer is handled
+    // internally by the VM.
+    let res = vm.execute_program(packet).unwrap();
+    println!("Program returned: {:?} ({:#x})", res, res);
+}
+```
+
+## Building eBPF programs
+
+Besides passing the raw hexadecimal codes for building eBPF programs, two other
+methods are available.
+
+### Assembler
+
+The first method consists in using the assembler provided by the crate.
+
+```rust
+extern crate rbpf;
+use rbpf::assembler::assemble;
+
+let prog = assemble("add64 r1, 0x605
+                     mov64 r2, 0x32
+                     mov64 r1, r0
+                     be16 r0
+                     neg64 r2
+                     exit").unwrap();
+
+#[cfg(feature = "std")] {
+    println!("{:?}", prog);
+}
+```
+
+The above snippet will produce:
+
+```rust,ignore
+Ok([0x07, 0x01, 0x00, 0x00, 0x05, 0x06, 0x00, 0x00,
+    0xb7, 0x02, 0x00, 0x00, 0x32, 0x00, 0x00, 0x00,
+    0xbf, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0xdc, 0x00, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00,
+    0x87, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00])
+```
+
+Conversely, a disassembler is also available to dump instruction names from
+bytecode in a human-friendly format.
+
+```rust
+extern crate rbpf;
+use rbpf::disassembler::disassemble;
+
+let prog = &[
+    0x07, 0x01, 0x00, 0x00, 0x05, 0x06, 0x00, 0x00,
+    0xb7, 0x02, 0x00, 0x00, 0x32, 0x00, 0x00, 0x00,
+    0xbf, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0xdc, 0x00, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00,
+    0x87, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+];
+
+disassemble(prog);
+```
+
+This will produce the following output:
+
+```txt
+add64 r1, 0x605
+mov64 r2, 0x32
+mov64 r1, r0
+be16 r0
+neg64 r2
+exit
+```
+
+Please refer to [source code](src/assembler.rs) and [tests](tests/assembler.rs)
+for the syntax and the list of instruction names.
+
+### Building API
+
+The other way to build programs is to chain commands from the instruction
+builder API. It looks less like assembly, maybe more like high-level functions.
+What's sure is that the result is more verbose, but if you prefer to build
+programs this way, it works just as well. If we take again the same sample as
+above, it would be constructed as follows.
+
+```rust
+extern crate rbpf;
+use rbpf::insn_builder::*;
+
+let mut program = BpfCode::new();
+program.add(Source::Imm, Arch::X64).set_dst(1).set_imm(0x605).push()
+       .mov(Source::Imm, Arch::X64).set_dst(2).set_imm(0x32).push()
+       .mov(Source::Reg, Arch::X64).set_src(0).set_dst(1).push()
+       .swap_bytes(Endian::Big).set_dst(0).set_imm(0x10).push()
+       .negate(Arch::X64).set_dst(2).push()
+       .exit().push();
+```
+
+Again, please refer to [the source and related tests](src/insn_builder.rs) to
+get more information and examples on how to use it.
+
+## Build features
+
+### `no_std`
+
+The `rbpf` crate has a Cargo feature named "std" that is enabled by default. To
+use `rbpf` in `no_std` environments this feature needs to be disabled. To do
+this, you need to modify your dependency on `rbpf` in Cargo.toml to disable the
+enabled-by-default features.
+
+```toml
+[dependencies]
+rbpf = { version = "1.0", default-features = false }
+```
+
+Note that when using this crate in `no_std` environments, the `jit` module
+isn't available. This is because it depends on functions provided by `libc`
+(`libc::posix_memalign()`, `libc::mprotect()`) which aren't available on
+`no_std`.
+
+The `assembler` module is available, albeit with reduced debugging features. It
+depends on the `combine` crate providing parser combinators. Under `no_std`
+this crate only provides simple parsers which generate less descriptive error
+messages.
+
+## Feedback welcome!
+
+This is the author's first try at writing Rust code. He learned a lot in the
+process, but there remains a feeling that this crate has a kind of C-ish style
+in some places instead of the Rusty look the author would like it to have. So
+feedback (or PRs) are welcome, including about ways you might see to take
+better advantage of Rust features.
+
+Note that the project expects new commits to be covered by the
+[Developer's Certificate of Origin](https://wiki.linuxfoundation.org/dco).
+When contributing Pull Requests, please sign off your commits accordingly.
+
+## Questions / Answers
+
+### Why implementing an eBPF virtual machine in Rust?
+
+As of this writing, there is no particular use case for this crate at the best
+of the author's knowledge. The author happens to work with BPF on Linux and to
+know how uBPF works, and he wanted to learn and experiment with Rust—no more
+than that.
+
+### What are the differences with uBPF?
+
+Other than the language, obviously? Well, there are some differences:
+
+* Some constants, such as the maximum length for programs or the length for the
+  stack, differs between uBPF and rbpf. The latter uses the same values as the
+  Linux kernel, while uBPF has its own values.
+
+* When an error occurs while a program is run by uBPF, the function running the
+  program silently returns the maximum value as an error code, while rbpf
+  returns Rust type `Error`.
+
+* The registration of helper functions, that can be called from within an eBPF
+  program, is not handled in the same way.
+
+* The distinct structs permitting to run program either on packet data, or with
+  a metadata buffer (simulated or not) is a specificity of rbpf.
+
+* As for performance: theoretically the JITted programs are expected to run at
+  the same speed, while the C interpreter of uBPF should go slightly faster
+  than rbpf. But this has not been asserted yet. Benchmarking both programs
+  would be an interesting thing to do.
+
+### Can I use it with the “classic” BPF (a.k.a cBPF) version?
+
+No. This crate only works with extended BPF (eBPF) programs. For cBPF programs,
+such as used by tcpdump (as of this writing) for example, you may be interested
+in the [bpfjit crate](https://crates.io/crates/bpfjit) written by Alexander
+Polakov instead.
+
+### What functionalities are implemented?
+
+Running and JIT-compiling eBPF programs work. There is also a mechanism to
+register user-defined helper functions. The eBPF implementation of the Linux
+kernel comes with [some additional
+features](https://github.com/iovisor/bcc/blob/master/docs/kernel-versions.md):
+a high number of helpers, several kinds of maps, tail calls.
+
+* Additional helpers should be easy to add, but very few of the existing Linux
+  helpers have been replicated in rbpf so far.
+
+* Tail calls (“long jumps” from an eBPF program into another) are not
+  implemented. This is probably not trivial to design and implement.
+
+* The interaction with maps is done through the use of specific helpers, so
+  this should not be difficult to add. The maps themselves can reuse the maps
+  in the kernel (if on Linux), to communicate with in-kernel eBPF programs for
+  instance; or they can be handled in user space. Rust has arrays and hashmaps,
+  so their implementation should be pretty straightforward (and may be added to
+  rbpf in the future).
+
+### What about program validation?
+
+The ”verifier” of this crate is very short and has nothing to do with the
+kernel verifier, which means that it accepts programs that may not be safe. On
+the other hand, you probably do not run this in a kernel here, so it will not
+crash your system. Implementing a verifier similar to the one in the kernel is
+not trivial, and we cannot “copy” it since it is under GPL license.
+
+### What about safety then?
+
+Rust has a strong emphasis on safety. Yet to have the eBPF VM work, some
+`unsafe` blocks of code are used. The VM, taken as an eBPF interpreter, can
+return an error but should not crash. Please file an issue otherwise.
+
+As for the JIT-compiler, it is a different story, since runtime memory checks
+are more complicated to implement in assembly. It _will_ crash if your
+JIT-compiled program tries to perform unauthorized memory accesses. Usually, it
+could be a good idea to test your program with the interpreter first.
+
+Oh, and if your program has infinite loops, even with the interpreter, you're
+on your own.
+
+## Caveats
+
+* This crate is **under development** and the API may be subject to change.
+
+* The JIT compiler produces an unsafe program: memory access are not tested at
+  runtime (yet). Use with caution.
+
+* A small number of eBPF instructions have not been implemented yet. This
+  should not be a problem for the majority of eBPF programs.
+
+* Beware of turnips. Turnips are disgusting.
+
+## _To do_ list
+
+* Implement some traits (`Clone`, `Drop`, `Debug` are good candidates).
+* Provide built-in support for user-space array and hash BPF maps.
+* Improve safety of JIT-compiled programs with runtime memory checks.
+* Add helpers (some of those supported in the kernel, such as checksum update,
+  could be helpful).
+* Improve verifier. Could we find a way to directly support programs compiled
+  with clang?
+* Maybe one day, tail calls?
+* JIT-compilers for other architectures?
+* …
+
+## License
+
+Following the effort of the Rust language project itself in order to ease
+integration with other projects, the rbpf crate is distributed under the terms
+of both the MIT license and the Apache License (Version 2.0).
+
+See
+[LICENSE-APACHE](https://github.com/qmonnet/rbpf/blob/main/LICENSE-APACHE)
+and [LICENSE-MIT](https://github.com/qmonnet/rbpf/blob/main/LICENSE-MIT) for
+details.
+
+## Version
+[The last commit](https://github.com/qmonnet/rbpf/commit/fe7021b07b08a43b836743a77796d07ce1f4902e)
+
+
+## Inspired by
+
+* [uBPF](https://github.com/iovisor/ubpf), a C user-space implementation of an
+  eBPF virtual machine, with a JIT-compiler and disassembler (and also
+  including the assembler from the human-readable form of the instructions,
+  such as in `mov r0, 0x1337`), by Rich Lane for Big Switch Networks (2015)
+
+* [_Building a simple JIT in
+  Rust_](https://www.sophiajt.com/building-a-simple-jit-in-rust),
+  by Sophia Turner (2015)
+
+* [bpfjit](https://github.com/polachok/bpfjit) (also [on
+  crates.io](https://crates.io/crates/bpfjit)), a Rust crate exporting the cBPF
+  JIT compiler from FreeBSD 10 tree to Rust, by Alexander Polakov (2016)
+
+## Other resources
+
+* Cilium project documentation about BPF: [_BPF and XDP Reference
+  Guide_](http://docs.cilium.io/en/latest/bpf/)
+
+* [Kernel documentation about BPF](https://docs.kernel.org/bpf/)
+
+* [_Dive into BPF: a list of reading
+  material_](https://qmonnet.github.io/whirl-offload/2016/09/01/dive-into-bpf),
+  a blog article listing documentation for BPF and related technologies (2016)
+
+* [The Rust programming language](https://www.rust-lang.org)

kernel/crates/rbpf/clippy.toml

@@ -0,0 +1 @@
+doc-valid-idents = ["eBPF", "uBPF"] 

kernel/crates/rbpf/examples/disassemble.rs

@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: (Apache-2.0 OR MIT)
+// Copyright 2017 6WIND S.A. <quentin.monnet@6wind.com>
+
+extern crate rbpf;
+use rbpf::disassembler;
+
+// Simply disassemble a program into human-readable instructions.
+fn main() {
+    let prog = &[
+        0xb7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x79, 0x12, 0x50, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x79, 0x11, 0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0xbf, 0x13, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x07, 0x03, 0x00, 0x00, 0x36, 0x00, 0x00, 0x00, 0x2d, 0x23, 0x12, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x69, 0x12, 0x0c, 0x00, 0x00, 0x00, 0x00, 0x00, 0x55, 0x02, 0x10, 0x00,
+        0x08, 0x00, 0x00, 0x00, 0x71, 0x12, 0x17, 0x00, 0x00, 0x00, 0x00, 0x00, 0x55, 0x02, 0x0e,
+        0x00, 0x06, 0x00, 0x00, 0x00, 0x18, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x79, 0x11, 0x22, 0x00, 0x00, 0x00, 0x00, 0x00, 0xbf,
+        0x12, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x57, 0x02, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00,
+        0x15, 0x02, 0x08, 0x00, 0x99, 0x99, 0x00, 0x00, 0x18, 0x02, 0x00, 0x00, 0x00, 0x00, 0xff,
+        0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x5f, 0x21, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0xb7, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0x18, 0x02, 0x00, 0x00, 0x00,
+        0x00, 0x99, 0x99, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1d, 0x21, 0x01, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0xb7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x95, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00,
+    ];
+    disassembler::disassemble(prog);
+}

kernel/crates/rbpf/examples/helper.rs

@@ -0,0 +1,3 @@
+fn main() {
+    rbpf::helpers::show_helper();
+}

kernel/crates/rbpf/examples/load_elf.rs

@@ -0,0 +1,115 @@
+// SPDX-License-Identifier: (Apache-2.0 OR MIT)
+// Copyright 2016 6WIND S.A. <quentin.monnet@6wind.com>
+
+#![allow(clippy::unreadable_literal)]
+
+extern crate elf;
+use std::path::PathBuf;
+
+extern crate rbpf;
+use rbpf::helpers;
+
+// The following example uses an ELF file that has been compiled from the C program available in
+// `load_elf__block_a_port.c` in the same directory.
+//
+// It was compiled with the following command:
+//
+// ```bash
+// clang -O2 -emit-llvm -c load_elf__block_a_port.c -o - | \
+//     llc -march=bpf -filetype=obj -o load_elf__block_a_port.o
+// ```
+//
+// Once compiled, this program can be injected into Linux kernel, with tc for instance. Sadly, we
+// need to bring some modifications to the generated bytecode in order to run it: the three
+// instructions with opcode 0x61 load data from a packet area as 4-byte words, where we need to
+// load it as 8-bytes double words (0x79). The kernel does the same kind of translation before
+// running the program, but rbpf does not implement this.
+//
+// In addition, the offset at which the pointer to the packet data is stored must be changed: since
+// we use 8 bytes instead of 4 for the start and end addresses of the data packet, we cannot use
+// the offsets produced by clang (0x4c and 0x50), the addresses would overlap. Instead we can use,
+// for example, 0x40 and 0x50.
+//
+// These change were applied with the following script:
+//
+// ```bash
+// xxd load_elf__block_a_port.o | sed '
+//     s/6112 5000 0000 0000/7912 5000 0000 0000/ ;
+//     s/6111 4c00 0000 0000/7911 4000 0000 0000/ ;
+//     s/6111 2200 0000 0000/7911 2200 0000 0000/' | xxd -r > load_elf__block_a_port.tmp
+
+// mv load_elf__block_a_port.tmp load_elf__block_a_port.o
+// ```
+//
+// The eBPF program was placed into the `.classifier` ELF section (see C code above), which means
+// that you can retrieve the raw bytecode with `readelf -x .classifier load_elf__block_a_port.o` or
+// with `objdump -s -j .classifier load_elf__block_a_port.o`.
+//
+// Once the bytecode has been edited, we can load the bytecode directly from the ELF object file.
+
+fn main() {
+    let filename = "examples/load_elf__block_a_port.elf";
+
+    let path = PathBuf::from(filename);
+    let file = match elf::File::open_path(path) {
+        Ok(f) => f,
+        Err(e) => panic!("Error: {:?}", e),
+    };
+
+    let text_scn = match file.get_section(".classifier") {
+        Some(s) => s,
+        None => panic!("Failed to look up .classifier section"),
+    };
+
+    let prog = &text_scn.data;
+
+    let packet1 = &mut [
+        0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xfe, 0xdc, 0xba, 0x98, 0x76, 0x54, 0x08,
+        0x00, // ethertype
+        0x45, 0x00, 0x00, 0x3b, // start ip_hdr
+        0xa6, 0xab, 0x40, 0x00, 0x40, 0x06, 0x96, 0x0f, 0x7f, 0x00, 0x00, 0x01, 0x7f, 0x00, 0x00,
+        0x01,
+        // Program matches the next two bytes: 0x9999 returns 0xffffffff, else return 0.
+        0x99, 0x99, 0xc6, 0xcc, // start tcp_hdr
+        0xd1, 0xe5, 0xc4, 0x9d, 0xd4, 0x30, 0xb5, 0xd2, 0x80, 0x18, 0x01, 0x56, 0xfe, 0x2f, 0x00,
+        0x00, 0x01, 0x01, 0x08, 0x0a, // start data
+        0x00, 0x23, 0x75, 0x89, 0x00, 0x23, 0x63, 0x2d, 0x71, 0x64, 0x66, 0x73, 0x64, 0x66, 0x0au8,
+    ];
+
+    let packet2 = &mut [
+        0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xfe, 0xdc, 0xba, 0x98, 0x76, 0x54, 0x08,
+        0x00, // ethertype
+        0x45, 0x00, 0x00, 0x3b, // start ip_hdr
+        0xa6, 0xab, 0x40, 0x00, 0x40, 0x06, 0x96, 0x0f, 0x7f, 0x00, 0x00, 0x01, 0x7f, 0x00, 0x00,
+        0x01,
+        // Program matches the next two bytes: 0x9999 returns 0xffffffff, else return 0.
+        0x98, 0x76, 0xc6, 0xcc, // start tcp_hdr
+        0xd1, 0xe5, 0xc4, 0x9d, 0xd4, 0x30, 0xb5, 0xd2, 0x80, 0x18, 0x01, 0x56, 0xfe, 0x2f, 0x00,
+        0x00, 0x01, 0x01, 0x08, 0x0a, // start data
+        0x00, 0x23, 0x75, 0x89, 0x00, 0x23, 0x63, 0x2d, 0x71, 0x64, 0x66, 0x73, 0x64, 0x66, 0x0au8,
+    ];
+
+    let mut vm = rbpf::EbpfVmFixedMbuff::new(Some(prog), 0x40, 0x50).unwrap();
+    vm.register_helper(helpers::BPF_TRACE_PRINTK_IDX, helpers::bpf_trace_printf)
+        .unwrap();
+
+    let res = vm.execute_program(packet1).unwrap();
+    println!("Packet #1, program returned: {res:?} ({res:#x})");
+    assert_eq!(res, 0xffffffff);
+
+    #[cfg(not(windows))]
+    {
+        vm.jit_compile().unwrap();
+
+        let res = unsafe { vm.execute_program_jit(packet2).unwrap() };
+        println!("Packet #2, program returned: {res:?} ({res:#x})");
+        assert_eq!(res, 0);
+    }
+
+    #[cfg(windows)]
+    {
+        let res = vm.execute_program(packet2).unwrap();
+        println!("Packet #2, program returned: {:?} ({:#x})", res, res);
+        assert_eq!(res, 0);
+    }
+}

kernel/crates/rbpf/examples/load_elf__block_a_port.c

@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: (APACHE-2.0 OR MIT)
+// Copyright 2016 6WIND S.A. <quentin.monnet@6wind.com>
+
+// Block TCP packets on source or destination port 0x9999.
+
+#include <linux/ip.h>
+#include <linux/in.h>
+#include <linux/tcp.h>
+#include <linux/bpf.h>
+
+#define ETH_ALEN 6
+#define ETH_P_IP 0x0008 /* htons(0x0800) */
+#define TCP_HDR_LEN 20
+
+#define BLOCKED_TCP_PORT 0x9999
+
+struct eth_hdr {
+    unsigned char   h_dest[ETH_ALEN];
+    unsigned char   h_source[ETH_ALEN];
+    unsigned short  h_proto;
+};
+
+#define SEC(NAME) __attribute__((section(NAME), used))
+SEC(".classifier")
+int handle_ingress(struct __sk_buff *skb)
+{
+    void *data = (void *)(long)skb->data;
+    void *data_end = (void *)(long)skb->data_end;
+    struct eth_hdr *eth = data;
+    struct iphdr *iph = data + sizeof(*eth);
+    struct tcphdr *tcp = data + sizeof(*eth) + sizeof(*iph);
+
+    /* single length check */
+    if (data + sizeof(*eth) + sizeof(*iph) + sizeof(*tcp) > data_end)
+        return 0;
+    if (eth->h_proto != ETH_P_IP)
+        return 0;
+    if (iph->protocol != IPPROTO_TCP)
+        return 0;
+    if (tcp->source == BLOCKED_TCP_PORT || tcp->dest == BLOCKED_TCP_PORT)
+        return -1;
+    return 0;
+}

kernel/crates/rbpf/examples/rbpf_plugin.rs

@@ -0,0 +1,126 @@
+// Copyright Microsoft Corporation
+// SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+// Path: examples/rbpf_plugin.rs
+use std::io::Read;
+
+// Helper function used by https://github.com/Alan-Jowett/bpf_conformance/blob/main/tests/call_unwind_fail.data
+fn _unwind(a: u64, _b: u64, _c: u64, _d: u64, _e: u64) -> u64 {
+    a
+}
+
+// This is a plugin for the bpf_conformance test suite (https://github.com/Alan-Jowett/bpf_conformance)
+// It accepts a single argument, the memory contents to pass to the VM.
+// It reads the program from stdin.
+fn main() {
+    let mut args: Vec<String> = std::env::args().collect();
+    #[allow(unused_mut)] // In no_std the jit variable isn't mutated.
+    let mut jit: bool = false;
+    let mut cranelift: bool = false;
+    let mut program_text = String::new();
+    let mut memory_text = String::new();
+
+    args.remove(0);
+
+    // Memory is always the first argument.
+    if !args.is_empty() {
+        memory_text.clone_from(&args[0]);
+        // Strip whitespace
+        memory_text.retain(|c| !c.is_whitespace());
+        args.remove(0);
+    }
+
+    // Process the rest of the arguments.
+    while !args.is_empty() {
+        match args[0].as_str() {
+            "--help" => {
+                println!("Usage: rbpf_plugin [memory] < program");
+                return;
+            }
+            "--jit" => {
+                #[cfg(any(windows, not(feature = "std")))]
+                {
+                    println!("JIT not supported");
+                    return;
+                }
+                #[cfg(all(not(windows), feature = "std"))]
+                {
+                    jit = true;
+                }
+            }
+            "--cranelift" => {
+                cranelift = true;
+
+                #[cfg(not(feature = "cranelift"))]
+                {
+                    let _ = cranelift;
+                    println!("Cranelift is not enabled");
+                    return;
+                }
+            }
+            "--program" => {
+                if args.len() < 2 {
+                    println!("Missing argument to --program");
+                    return;
+                }
+                args.remove(0);
+                if !args.is_empty() {
+                    program_text.clone_from(&args[0]);
+                    args.remove(0);
+                }
+            }
+            _ => panic!("Unknown argument {}", args[0]),
+        }
+        args.remove(0);
+    }
+
+    if program_text.is_empty() {
+        // Read program text from stdin
+        std::io::stdin().read_to_string(&mut program_text).unwrap();
+    }
+
+    // Strip whitespace
+    program_text.retain(|c| !c.is_whitespace());
+
+    // Convert program from hex to bytecode
+    let bytecode = hex::decode(program_text).unwrap();
+
+    // Convert memory from hex to bytes
+    let mut memory: Vec<u8> = hex::decode(memory_text).unwrap();
+
+    // Create rbpf vm
+    let mut vm = rbpf::EbpfVmRaw::new(Some(&bytecode)).unwrap();
+
+    // Register the helper function used by call_unwind_fail.data test.
+    vm.register_helper(5, _unwind).unwrap();
+
+    let result: u64;
+    if jit {
+        #[cfg(any(windows, not(feature = "std")))]
+        {
+            println!("JIT not supported");
+            return;
+        }
+        #[cfg(all(not(windows), feature = "std"))]
+        {
+            unsafe {
+                vm.jit_compile().unwrap();
+                result = vm.execute_program_jit(&mut memory).unwrap();
+            }
+        }
+    } else if cranelift {
+        #[cfg(not(feature = "cranelift"))]
+        {
+            println!("Cranelift is not enabled");
+            return;
+        }
+        #[cfg(feature = "cranelift")]
+        {
+            vm.cranelift_compile().unwrap();
+            result = vm.execute_program_cranelift(&mut memory).unwrap();
+        }
+    } else {
+        result = vm.execute_program(&mut memory).unwrap();
+    }
+    println!("{result:x}");
+}

kernel/crates/rbpf/examples/to_json.rs

@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: (Apache-2.0 OR MIT)
+// Copyright 2017 6WIND S.A. <quentin.monnet@6wind.com>
+
+#[macro_use]
+extern crate json;
+
+extern crate elf;
+use std::path::PathBuf;
+
+extern crate rbpf;
+use rbpf::disassembler;
+
+// Turn a program into a JSON string.
+//
+// Relies on `json` crate.
+//
+// You may copy this function and adapt it according to your needs. For instance, you may want to:
+//
+// * Remove the "desc" (description) attributes from the output.
+// * Print integers as integers, and not as strings containing their hexadecimal representation
+//   (just replace the relevant `format!()` calls by the commented values.
+fn to_json(prog: &[u8]) -> String {
+    // This call returns a high-level representation of the instructions, with the two parts of
+    // `LD_DW_IMM` instructions merged, and name and descriptions of the instructions.
+    // If you prefer to use a lower-level representation, use `ebpf::to_insn_vec()` function
+    // instead.
+    let insns = disassembler::to_insn_vec(prog);
+    let mut json_insns = vec![];
+    for insn in insns {
+        json_insns.push(object!(
+            "opc"  => format!("{:#x}", insn.opc), // => insn.opc,
+            "dst"  => format!("{:#x}", insn.dst), // => insn.dst,
+            "src"  => format!("{:#x}", insn.src), // => insn.src,
+            "off"  => format!("{:#x}", insn.off), // => insn.off,
+            // Warning: for imm we use a i64 instead of a i32 (to have correct values for
+            // `lddw` operation. If we print a number in the JSON this is not a problem, the
+            // internal i64 has the same value with extended sign on 32 most significant bytes.
+            // If we print the hexadecimal value as a string however, we want to cast as a i32
+            // to prevent all other instructions to print spurious `ffffffff` prefix if the
+            // number is negative. When values takes more than 32 bits with `lddw`, the cast
+            // has no effect and the complete value is printed anyway.
+            "imm"  => format!("{:#x}", insn.imm as i32), // => insn.imm,
+            "desc" => insn.desc
+        ));
+    }
+    json::stringify_pretty(
+        object!(
+        "size"  => json_insns.len(),
+        "insns" => json_insns
+        ),
+        4,
+    )
+}
+
+// Load a program from an object file, and prints it to standard output as a JSON string.
+fn main() {
+    // Let's reuse this file from `load_elf/example`.
+    let filename = "examples/load_elf__block_a_port.elf";
+
+    let path = PathBuf::from(filename);
+    let file = match elf::File::open_path(path) {
+        Ok(f) => f,
+        Err(e) => panic!("Error: {:?}", e),
+    };
+
+    let text_scn = match file.get_section(".classifier") {
+        Some(s) => s,
+        None => panic!("Failed to look up .classifier section"),
+    };
+
+    let prog = &text_scn.data;
+
+    println!("{}", to_json(prog));
+}

kernel/crates/rbpf/examples/uptime.rs

@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: (Apache-2.0 OR MIT)
+// Copyright 2017 6WIND S.A. <quentin.monnet@6wind.com>
+
+extern crate rbpf;
+use rbpf::helpers;
+
+// The main objectives of this example is to show:
+//
+// * the use of EbpfVmNoData function,
+// * and the use of a helper.
+//
+// The two eBPF programs are independent and are not related to one another.
+fn main() {
+    let prog1 = &[
+        0xb4, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov32 r0, 0
+        0xb4, 0x01, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, // mov32 r1, 2
+        0x04, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, // add32 r0, 1
+        0x0c, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // add32 r0, r1
+        0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // exit and return r0
+    ];
+
+    // We use helper `bpf_time_getns()`, which is similar to helper `bpf_ktime_getns()` from Linux
+    // kernel. Hence rbpf::helpers module provides the index of this in-kernel helper as a
+    // constant, so that we can remain compatible with programs for the kernel. Here we also cast
+    // it to a u8 so as to use it directly in program instructions.
+    let hkey = helpers::BPF_KTIME_GETNS_IDX as u8;
+    let prog2 = &[
+        0xb7, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov64 r1, 0
+        0xb7, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov64 r1, 0
+        0xb7, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov64 r1, 0
+        0xb7, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov64 r1, 0
+        0xb7, 0x05, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // mov64 r1, 0
+        0x85, 0x00, 0x00, 0x00, hkey, 0x00, 0x00, 0x00, // call helper <hkey>
+        0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // exit and return r0
+    ];
+
+    // Create a VM: this one takes no data. Load prog1 in it.
+    let mut vm = rbpf::EbpfVmNoData::new(Some(prog1)).unwrap();
+    // Execute prog1.
+    assert_eq!(vm.execute_program().unwrap(), 0x3);
+
+    // As struct EbpfVmNoData does not takes any memory area, its return value is mostly
+    // deterministic. So we know prog1 will always return 3. There is an exception: when it uses
+    // helpers, the latter may have non-deterministic values, and all calls may not return the same
+    // value.
+    //
+    // In the following example we use a helper to get the elapsed time since boot time: we
+    // reimplement uptime in eBPF, in Rust. Because why not.
+
+    vm.set_program(prog2).unwrap();
+    vm.register_helper(helpers::BPF_KTIME_GETNS_IDX, helpers::bpf_time_getns)
+        .unwrap();
+
+    let time;
+
+    #[cfg(all(not(windows), feature = "std"))]
+    {
+        vm.jit_compile().unwrap();
+
+        time = unsafe { vm.execute_program_jit().unwrap() };
+    }
+
+    #[cfg(any(windows, not(feature = "std")))]
+    {
+        time = vm.execute_program().unwrap();
+    }
+
+    let days = time / 10u64.pow(9) / 60 / 60 / 24;
+    let hours = (time / 10u64.pow(9) / 60 / 60) % 24;
+    let minutes = (time / 10u64.pow(9) / 60) % 60;
+    let seconds = (time / 10u64.pow(9)) % 60;
+    let nanosec = time % 10u64.pow(9);
+
+    println!(
+        "Uptime: {:#x} ns == {} days {:02}:{:02}:{:02}, {} ns",
+        time, days, hours, minutes, seconds, nanosec
+    );
+}

kernel/crates/rbpf/mk/appveyor.bat

@@ -0,0 +1,72 @@
+echo on
+SetLocal EnableDelayedExpansion
+
+REM This is the recommended way to choose the toolchain version, according to
+REM Appveyor's documentation.
+SET PATH=C:\Program Files (x86)\MSBuild\%TOOLCHAIN_VERSION%\Bin;%PATH%
+
+set VCVARSALL="C:\Program Files (x86)\Microsoft Visual Studio %TOOLCHAIN_VERSION%\VC\vcvarsall.bat"
+
+if [%Platform%] NEQ [x64] goto win32
+set TARGET_ARCH=x86_64
+set TARGET_PROGRAM_FILES=%ProgramFiles%
+call %VCVARSALL% amd64
+if %ERRORLEVEL% NEQ 0 exit 1
+goto download
+
+:win32
+echo on
+if [%Platform%] NEQ [Win32] exit 1
+set TARGET_ARCH=i686
+set TARGET_PROGRAM_FILES=%ProgramFiles(x86)%
+call %VCVARSALL% amd64_x86
+if %ERRORLEVEL% NEQ 0 exit 1
+goto download
+
+:download
+REM vcvarsall turns echo off
+echo on
+
+mkdir windows_build_tools
+mkdir windows_build_tools\
+echo Downloading Yasm...
+powershell -Command "(New-Object Net.WebClient).DownloadFile('http://www.tortall.net/projects/yasm/releases/yasm-1.3.0-win64.exe', 'windows_build_tools\yasm.exe')"
+if %ERRORLEVEL% NEQ 0 (
+  echo ...downloading Yasm failed.
+  exit 1
+)
+
+set RUST_URL=https://static.rust-lang.org/dist/rust-%RUST%-%TARGET_ARCH%-pc-windows-msvc.msi
+echo Downloading %RUST_URL%...
+mkdir build
+powershell -Command "(New-Object Net.WebClient).DownloadFile('%RUST_URL%', 'build\rust-%RUST%-%TARGET_ARCH%-pc-windows-msvc.msi')"
+if %ERRORLEVEL% NEQ 0 (
+  echo ...downloading Rust failed.
+  exit 1
+)
+
+start /wait msiexec /i build\rust-%RUST%-%TARGET_ARCH%-pc-windows-msvc.msi INSTALLDIR="%TARGET_PROGRAM_FILES%\Rust %RUST%" /quiet /qn /norestart
+if %ERRORLEVEL% NEQ 0 exit 1
+
+set PATH="%TARGET_PROGRAM_FILES%\Rust %RUST%\bin";%cd%\windows_build_tools;%PATH%
+
+if [%Configuration%] == [Release] set CARGO_MODE=--release
+
+set
+
+link /?
+cl /?
+rustc --version
+cargo --version
+
+cargo test --all-features -vv %CARGO_MODE%
+if %ERRORLEVEL% NEQ 0 exit 1
+
+REM Verify that `cargo build`, independent from `cargo test`, works; i.e.
+REM verify that non-test builds aren't trying to use test-only features.
+cargo build -vv %CARGO_MODE%
+if %ERRORLEVEL% NEQ 0 exit 1
+
+REM Verify that we can build with all features
+cargo build --all-features -vv %CARGO_MODE%
+if %ERRORLEVEL% NEQ 0 exit 1

kernel/crates/rbpf/rustfmt.toml

@@ -0,0 +1,3 @@
+group_imports="StdExternalCrate"
+reorder_imports=true
+imports_granularity="Crate"

kernel/crates/rbpf/src/asm_parser.rs

@@ -0,0 +1,642 @@
+// SPDX-License-Identifier: (Apache-2.0 OR MIT)
+// Copyright 2017 Rich Lane <lanerl@gmail.com>
+
+// Rust-doc comments were left in the module, but it is no longer publicly exposed from the root
+// file of the crate. Do not expect to find those comments in the documentation of the crate.
+
+//! This module parses eBPF assembly language source code.
+
+use alloc::{
+    string::{String, ToString},
+    vec::Vec,
+};
+
+#[cfg(feature = "std")]
+use combine::EasyParser;
+use combine::{
+    attempt, between, eof, many, many1, one_of, optional,
+    parser::char::{alpha_num, char, digit, hex_digit, spaces, string},
+    sep_by,
+    stream::position::{self},
+    ParseError, Parser, Stream,
+};
+
+/// Operand of an instruction.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum Operand {
+    /// Register number.
+    Register(i64),
+    /// Jump offset or immediate.
+    Integer(i64),
+    /// Register number and offset.
+    Memory(i64, i64),
+    /// Used for pattern matching.
+    Nil,
+}
+
+/// Parsed instruction.
+#[derive(Debug, PartialEq, Eq)]
+pub struct Instruction {
+    /// Instruction name.
+    pub name: String,
+    /// Operands.
+    pub operands: Vec<Operand>,
+}
+
+fn ident<I>() -> impl Parser<I, Output = String>
+where
+    I: Stream<Token = char>,
+    I::Error: ParseError<I::Token, I::Range, I::Position>,
+{
+    many1(alpha_num())
+}
+
+fn integer<I>() -> impl Parser<I, Output = i64>
+where
+    I: Stream<Token = char>,
+    I::Error: ParseError<I::Token, I::Range, I::Position>,
+{
+    let sign = optional(one_of("-+".chars())).map(|x| match x {
+        Some('-') => -1,
+        _ => 1,
+    });
+    let hex = string("0x")
+        .with(many1(hex_digit()))
+        .map(|x: String| u64::from_str_radix(&x, 16).unwrap() as i64);
+    let dec = many1(digit()).map(|x: String| x.parse::<i64>().unwrap());
+    (sign, attempt(hex).or(dec)).map(|(s, x)| s * x)
+}
+
+fn register<I>() -> impl Parser<I, Output = i64>
+where
+    I: Stream<Token = char>,
+    I::Error: ParseError<I::Token, I::Range, I::Position>,
+{
+    char('r')
+        .with(many1(digit()))
+        .map(|x: String| x.parse::<i64>().unwrap())
+}
+
+fn operand<I>() -> impl Parser<I, Output = Operand>
+where
+    I: Stream<Token = char>,
+    I::Error: ParseError<I::Token, I::Range, I::Position>,
+{
+    let register_operand = register().map(Operand::Register);
+    let immediate = integer().map(Operand::Integer);
+    let memory = between(char('['), char(']'), (register(), optional(integer())))
+        .map(|t| Operand::Memory(t.0, t.1.unwrap_or(0)));
+    register_operand.or(immediate).or(memory)
+}
+
+fn instruction<I>() -> impl Parser<I, Output = Instruction>
+where
+    I: Stream<Token = char>,
+    I::Error: ParseError<I::Token, I::Range, I::Position>,
+{
+    let operands = sep_by(operand(), char(',').skip(spaces()));
+    (ident().skip(spaces()), operands, spaces()).map(|t| Instruction {
+        name: t.0,
+        operands: t.1,
+    })
+}
+
+/// Parse a string into a list of instructions.
+///
+/// The instructions are not validated and may have invalid names and operand types.
+pub fn parse(input: &str) -> Result<Vec<Instruction>, String> {
+    let mut with = spaces().with(many(instruction()).skip(eof()));
+
+    #[cfg(feature = "std")]
+    {
+        match with.easy_parse(position::Stream::new(input)) {
+            Ok((insts, _)) => Ok(insts),
+            Err(err) => Err(err.to_string()),
+        }
+    }
+    #[cfg(not(feature = "std"))]
+    {
+        match with.parse(position::Stream::new(input)) {
+            Ok((insts, _)) => Ok(insts),
+            Err(err) => Err(err.to_string()),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use alloc::{string::ToString, vec};
+
+    use combine::Parser;
+
+    use super::{ident, instruction, integer, operand, parse, register, Instruction, Operand};
+
+    // Unit tests for the different kinds of parsers.
+
+    #[test]
+    fn test_ident() {
+        assert_eq!(ident().parse("nop"), Ok(("nop".to_string(), "")));
+        assert_eq!(ident().parse("add32"), Ok(("add32".to_string(), "")));
+        assert_eq!(ident().parse("add32*"), Ok(("add32".to_string(), "*")));
+    }
+
+    #[test]
+    fn test_integer() {
+        assert_eq!(integer().parse("0"), Ok((0, "")));
+        assert_eq!(integer().parse("42"), Ok((42, "")));
+        assert_eq!(integer().parse("+42"), Ok((42, "")));
+        assert_eq!(integer().parse("-42"), Ok((-42, "")));
+        assert_eq!(integer().parse("0x0"), Ok((0, "")));
+        assert_eq!(
+            integer().parse("0x123456789abcdef0"),
+            Ok((0x123456789abcdef0, ""))
+        );
+        assert_eq!(integer().parse("-0x1f"), Ok((-31, "")));
+    }
+
+    #[test]
+    fn test_register() {
+        assert_eq!(register().parse("r0"), Ok((0, "")));
+        assert_eq!(register().parse("r15"), Ok((15, "")));
+    }
+
+    #[test]
+    fn test_operand() {
+        assert_eq!(operand().parse("r0"), Ok((Operand::Register(0), "")));
+        assert_eq!(operand().parse("r15"), Ok((Operand::Register(15), "")));
+        assert_eq!(operand().parse("0"), Ok((Operand::Integer(0), "")));
+        assert_eq!(operand().parse("42"), Ok((Operand::Integer(42), "")));
+        assert_eq!(operand().parse("[r1]"), Ok((Operand::Memory(1, 0), "")));
+        assert_eq!(operand().parse("[r3+5]"), Ok((Operand::Memory(3, 5), "")));
+        assert_eq!(
+            operand().parse("[r3+0x1f]"),
+            Ok((Operand::Memory(3, 31), ""))
+        );
+        assert_eq!(
+            operand().parse("[r3-0x1f]"),
+            Ok((Operand::Memory(3, -31), ""))
+        );
+    }
+
+    #[test]
+    fn test_instruction() {
+        assert_eq!(
+            instruction().parse("exit"),
+            Ok((
+                Instruction {
+                    name: "exit".to_string(),
+                    operands: vec![],
+                },
+                ""
+            ))
+        );
+
+        assert_eq!(
+            instruction().parse("call 2"),
+            Ok((
+                Instruction {
+                    name: "call".to_string(),
+                    operands: vec![Operand::Integer(2)],
+                },
+                ""
+            ))
+        );
+
+        assert_eq!(
+            instruction().parse("addi r1, 2"),
+            Ok((
+                Instruction {
+                    name: "addi".to_string(),
+                    operands: vec![Operand::Register(1), Operand::Integer(2)],
+                },
+                ""
+            ))
+        );
+
+        assert_eq!(
+            instruction().parse("ldxb r2, [r1+12]"),
+            Ok((
+                Instruction {
+                    name: "ldxb".to_string(),
+                    operands: vec![Operand::Register(2), Operand::Memory(1, 12)],
+                },
+                ""
+            ))
+        );
+
+        assert_eq!(
+            instruction().parse("lsh r3, 0x8"),
+            Ok((
+                Instruction {
+                    name: "lsh".to_string(),
+                    operands: vec![Operand::Register(3), Operand::Integer(8)],
+                },
+                ""
+            ))
+        );
+
+        assert_eq!(
+            instruction().parse("jne r3, 0x8, +37"),
+            Ok((
+                Instruction {
+                    name: "jne".to_string(),
+                    operands: vec![
+                        Operand::Register(3),
+                        Operand::Integer(8),
+                        Operand::Integer(37)
+                    ],
+                },
+                ""
+            ))
+        );
+
+        // Whitespace between operands is optional.
+        assert_eq!(
+            instruction().parse("jne r3,0x8,+37"),
+            Ok((
+                Instruction {
+                    name: "jne".to_string(),
+                    operands: vec![
+                        Operand::Register(3),
+                        Operand::Integer(8),
+                        Operand::Integer(37)
+                    ],
+                },
+                ""
+            ))
+        );
+    }
+
+    // Other unit tests: try to parse various set of instructions.
+
+    #[test]
+    fn test_empty() {
+        assert_eq!(parse(""), Ok(vec![]));
+    }
+
+    #[test]
+    fn test_exit() {
+        // No operands.
+        assert_eq!(
+            parse("exit"),
+            Ok(vec![Instruction {
+                name: "exit".to_string(),
+                operands: vec![],
+            }])
+        );
+    }
+
+    #[test]
+    fn test_lsh() {
+        // Register and immediate operands.
+        assert_eq!(
+            parse("lsh r3, 0x20"),
+            Ok(vec![Instruction {
+                name: "lsh".to_string(),
+                operands: vec![Operand::Register(3), Operand::Integer(0x20)],
+            }])
+        );
+    }
+
+    #[test]
+    fn test_ja() {
+        // Jump offset operand.
+        assert_eq!(
+            parse("ja +1"),
+            Ok(vec![Instruction {
+                name: "ja".to_string(),
+                operands: vec![Operand::Integer(1)],
+            }])
+        );
+    }
+
+    #[test]
+    fn test_ldxh() {
+        // Register and memory operands.
+        assert_eq!(
+            parse("ldxh r4, [r1+12]"),
+            Ok(vec![Instruction {
+                name: "ldxh".to_string(),
+                operands: vec![Operand::Register(4), Operand::Memory(1, 12)],
+            }])
+        );
+    }
+
+    #[test]
+    fn test_tcp_sack() {
+        // Sample program from ubpf.
+        // We could technically indent the instructions since the parser support white spaces at
+        // the beginning, but there is another test for that.
+        let src = "\
+ldxb r2, [r1+12]
+ldxb r3, [r1+13]
+lsh r3, 0x8
+or r3, r2
+mov r0, 0x0
+jne r3, 0x8, +37
+ldxb r2, [r1+23]
+jne r2, 0x6, +35
+ldxb r2, [r1+14]
+add r1, 0xe
+and r2, 0xf
+lsh r2, 0x2
+add r1, r2
+mov r0, 0x0
+ldxh r4, [r1+12]
+add r1, 0x14
+rsh r4, 0x2
+and r4, 0x3c
+mov r2, r4
+add r2, 0xffffffec
+mov r5, 0x15
+mov r3, 0x0
+jgt r5, r4, +20
+mov r5, r3
+lsh r5, 0x20
+arsh r5, 0x20
+mov r4, r1
+add r4, r5
+ldxb r5, [r4]
+jeq r5, 0x1, +4
+jeq r5, 0x0, +12
+mov r6, r3
+jeq r5, 0x5, +9
+ja +2
+add r3, 0x1
+mov r6, r3
+ldxb r3, [r4+1]
+add r3, r6
+lsh r3, 0x20
+arsh r3, 0x20
+jsgt r2, r3, -18
+ja +1
+mov r0, 0x1
+exit
+";
+
+        assert_eq!(
+            parse(src),
+            Ok(vec![
+                Instruction {
+                    name: "ldxb".to_string(),
+                    operands: vec![Operand::Register(2), Operand::Memory(1, 12)],
+                },
+                Instruction {
+                    name: "ldxb".to_string(),
+                    operands: vec![Operand::Register(3), Operand::Memory(1, 13)],
+                },
+                Instruction {
+                    name: "lsh".to_string(),
+                    operands: vec![Operand::Register(3), Operand::Integer(8)],
+                },
+                Instruction {
+                    name: "or".to_string(),
+                    operands: vec![Operand::Register(3), Operand::Register(2)],
+                },
+                Instruction {
+                    name: "mov".to_string(),
+                    operands: vec![Operand::Register(0), Operand::Integer(0)],
+                },
+                Instruction {
+                    name: "jne".to_string(),
+                    operands: vec![
+                        Operand::Register(3),
+                        Operand::Integer(8),
+                        Operand::Integer(37)
+                    ],
+                },
+                Instruction {
+                    name: "ldxb".to_string(),
+                    operands: vec![Operand::Register(2), Operand::Memory(1, 23)],
+                },
+                Instruction {
+                    name: "jne".to_string(),
+                    operands: vec![
+                        Operand::Register(2),
+                        Operand::Integer(6),
+                        Operand::Integer(35)
+                    ],
+                },
+                Instruction {
+                    name: "ldxb".to_string(),
+                    operands: vec![Operand::Register(2), Operand::Memory(1, 14)],
+                },
+                Instruction {
+                    name: "add".to_string(),
+                    operands: vec![Operand::Register(1), Operand::Integer(14)],
+                },
+                Instruction {
+                    name: "and".to_string(),
+                    operands: vec![Operand::Register(2), Operand::Integer(15)],
+                },
+                Instruction {
+                    name: "lsh".to_string(),
+                    operands: vec![Operand::Register(2), Operand::Integer(2)],
+                },
+                Instruction {
+                    name: "add".to_string(),
+                    operands: vec![Operand::Register(1), Operand::Register(2)],
+                },
+                Instruction {
+                    name: "mov".to_string(),
+                    operands: vec![Operand::Register(0), Operand::Integer(0)],
+                },
+                Instruction {
+                    name: "ldxh".to_string(),
+                    operands: vec![Operand::Register(4), Operand::Memory(1, 12)],
+                },
+                Instruction {
+                    name: "add".to_string(),
+                    operands: vec![Operand::Register(1), Operand::Integer(20)],
+                },
+                Instruction {
+                    name: "rsh".to_string(),
+                    operands: vec![Operand::Register(4), Operand::Integer(2)],
+                },
+                Instruction {
+                    name: "and".to_string(),
+                    operands: vec![Operand::Register(4), Operand::Integer(60)],
+                },
+                Instruction {
+                    name: "mov".to_string(),
+                    operands: vec![Operand::Register(2), Operand::Register(4)],
+                },
+                Instruction {
+                    name: "add".to_string(),
+                    operands: vec![Operand::Register(2), Operand::Integer(4294967276)],
+                },
+                Instruction {
+                    name: "mov".to_string(),
+                    operands: vec![Operand::Register(5), Operand::Integer(21)],
+                },
+                Instruction {
+                    name: "mov".to_string(),
+                    operands: vec![Operand::Register(3), Operand::Integer(0)],
+                },
+                Instruction {
+                    name: "jgt".to_string(),
+                    operands: vec![
+                        Operand::Register(5),
+                        Operand::Register(4),
+                        Operand::Integer(20)
+                    ],
+                },
+                Instruction {
+                    name: "mov".to_string(),
+                    operands: vec![Operand::Register(5), Operand::Register(3)],
+                },
+                Instruction {
+                    name: "lsh".to_string(),
+                    operands: vec![Operand::Register(5), Operand::Integer(32)],
+                },
+                Instruction {
+                    name: "arsh".to_string(),
+                    operands: vec![Operand::Register(5), Operand::Integer(32)],
+                },
+                Instruction {
+                    name: "mov".to_string(),
+                    operands: vec![Operand::Register(4), Operand::Register(1)],
+                },
+                Instruction {
+                    name: "add".to_string(),
+                    operands: vec![Operand::Register(4), Operand::Register(5)],
+                },
+                Instruction {
+                    name: "ldxb".to_string(),
+                    operands: vec![Operand::Register(5), Operand::Memory(4, 0)],
+                },
+                Instruction {
+                    name: "jeq".to_string(),
+                    operands: vec![
+                        Operand::Register(5),
+                        Operand::Integer(1),
+                        Operand::Integer(4)
+                    ],
+                },
+                Instruction {
+                    name: "jeq".to_string(),
+                    operands: vec![
+                        Operand::Register(5),
+                        Operand::Integer(0),
+                        Operand::Integer(12)
+                    ],
+                },
+                Instruction {
+                    name: "mov".to_string(),
+                    operands: vec![Operand::Register(6), Operand::Register(3)],
+                },
+                Instruction {
+                    name: "jeq".to_string(),
+                    operands: vec![
+                        Operand::Register(5),
+                        Operand::Integer(5),
+                        Operand::Integer(9)
+                    ],
+                },
+                Instruction {
+                    name: "ja".to_string(),
+                    operands: vec![Operand::Integer(2)],
+                },
+                Instruction {
+                    name: "add".to_string(),
+                    operands: vec![Operand::Register(3), Operand::Integer(1)],
+                },
+                Instruction {
+                    name: "mov".to_string(),
+                    operands: vec![Operand::Register(6), Operand::Register(3)],
+                },
+                Instruction {
+                    name: "ldxb".to_string(),
+                    operands: vec![Operand::Register(3), Operand::Memory(4, 1)],
+                },
+                Instruction {
+                    name: "add".to_string(),
+                    operands: vec![Operand::Register(3), Operand::Register(6)],
+                },
+                Instruction {
+                    name: "lsh".to_string(),
+                    operands: vec![Operand::Register(3), Operand::Integer(32)],
+                },
+                Instruction {
+                    name: "arsh".to_string(),
+                    operands: vec![Operand::Register(3), Operand::Integer(32)],
+                },
+                Instruction {
+                    name: "jsgt".to_string(),
+                    operands: vec![
+                        Operand::Register(2),
+                        Operand::Register(3),
+                        Operand::Integer(-18)
+                    ],
+                },
+                Instruction {
+                    name: "ja".to_string(),
+                    operands: vec![Operand::Integer(1)],
+                },
+                Instruction {
+                    name: "mov".to_string(),
+                    operands: vec![Operand::Register(0), Operand::Integer(1)],
+                },
+                Instruction {
+                    name: "exit".to_string(),
+                    operands: vec![],
+                }
+            ])
+        );
+    }
+
+    /// When running without `std` the `EasyParser` provided by `combine`
+    /// cannot be used. Because of this we need to use the `Parser` and the
+    /// error messages are different.
+    #[test]
+    fn test_error_eof() {
+        let expected_error;
+        #[cfg(feature = "std")]
+        {
+            expected_error = Err(
+                "Parse error at line: 1, column: 6\nUnexpected end of input\nExpected digit\n"
+                    .to_string(),
+            );
+        }
+        #[cfg(not(feature = "std"))]
+        {
+            expected_error = Err("unexpected parse".to_string());
+        }
+        // Unexpected end of input in a register name.
+        assert_eq!(parse("lsh r"), expected_error);
+    }
+
+    /// When running without `std` the `EasyParser` provided by `combine`
+    /// cannot be used. Because of this we need to use the `Parser` and the
+    /// error messages are different.
+    #[test]
+    fn test_error_unexpected_character() {
+        let expected_error;
+        #[cfg(feature = "std")]
+        {
+            expected_error = Err(
+                "Parse error at line: 2, column: 1\nUnexpected `^`\nExpected letter or digit, whitespaces, `r`, `-`, `+`, `[` or end of input\n".to_string()
+            );
+        }
+        #[cfg(not(feature = "std"))]
+        {
+            expected_error = Err("unexpected parse".to_string());
+        }
+        // Unexpected character at end of input.
+        assert_eq!(parse("exit\n^"), expected_error);
+    }
+
+    #[test]
+    fn test_initial_whitespace() {
+        assert_eq!(
+            parse(
+                " 
+                          exit"
+            ),
+            Ok(vec![Instruction {
+                name: "exit".to_string(),
+                operands: vec![],
+            }])
+        );
+    }
+}

kernel/crates/rbpf/src/assembler.rs

@@ -0,0 +1,277 @@
+// SPDX-License-Identifier: (Apache-2.0 OR MIT)
+// Copyright 2017 Rich Lane <lanerl@gmail.com>
+
+//! This module translates eBPF assembly language to binary.
+
+use alloc::{
+    collections::BTreeMap,
+    format,
+    string::{String, ToString},
+    vec,
+    vec::Vec,
+};
+
+use self::InstructionType::{
+    AluBinary, AluUnary, Call, Endian, JumpConditional, JumpUnconditional, LoadAbs, LoadImm,
+    LoadInd, LoadReg, NoOperand, StoreImm, StoreReg,
+};
+use crate::{
+    asm_parser::{
+        parse, Instruction, Operand,
+        Operand::{Integer, Memory, Nil, Register},
+    },
+    ebpf::{self, Insn},
+};
+
+#[derive(Clone, Copy, Debug, PartialEq)]
+enum InstructionType {
+    AluBinary,
+    AluUnary,
+    LoadImm,
+    LoadAbs,
+    LoadInd,
+    LoadReg,
+    StoreImm,
+    StoreReg,
+    JumpUnconditional,
+    JumpConditional,
+    Call,
+    Endian(i64),
+    NoOperand,
+}
+
+fn make_instruction_map() -> BTreeMap<String, (InstructionType, u8)> {
+    let mut result = BTreeMap::new();
+
+    let alu_binary_ops = [
+        ("add", ebpf::BPF_ADD),
+        ("sub", ebpf::BPF_SUB),
+        ("mul", ebpf::BPF_MUL),
+        ("div", ebpf::BPF_DIV),
+        ("or", ebpf::BPF_OR),
+        ("and", ebpf::BPF_AND),
+        ("lsh", ebpf::BPF_LSH),
+        ("rsh", ebpf::BPF_RSH),
+        ("mod", ebpf::BPF_MOD),
+        ("xor", ebpf::BPF_XOR),
+        ("mov", ebpf::BPF_MOV),
+        ("arsh", ebpf::BPF_ARSH),
+    ];
+
+    let mem_sizes = [
+        ("w", ebpf::BPF_W),
+        ("h", ebpf::BPF_H),
+        ("b", ebpf::BPF_B),
+        ("dw", ebpf::BPF_DW),
+    ];
+
+    let jump_conditions = [
+        ("jeq", ebpf::BPF_JEQ),
+        ("jgt", ebpf::BPF_JGT),
+        ("jge", ebpf::BPF_JGE),
+        ("jlt", ebpf::BPF_JLT),
+        ("jle", ebpf::BPF_JLE),
+        ("jset", ebpf::BPF_JSET),
+        ("jne", ebpf::BPF_JNE),
+        ("jsgt", ebpf::BPF_JSGT),
+        ("jsge", ebpf::BPF_JSGE),
+        ("jslt", ebpf::BPF_JSLT),
+        ("jsle", ebpf::BPF_JSLE),
+    ];
+
+    {
+        let mut entry = |name: &str, inst_type: InstructionType, opc: u8| {
+            result.insert(name.to_string(), (inst_type, opc))
+        };
+
+        // Miscellaneous.
+        entry("exit", NoOperand, ebpf::EXIT);
+        entry("ja", JumpUnconditional, ebpf::JA);
+        entry("call", Call, ebpf::CALL);
+        entry("lddw", LoadImm, ebpf::LD_DW_IMM);
+
+        // AluUnary.
+        entry("neg", AluUnary, ebpf::NEG64);
+        entry("neg32", AluUnary, ebpf::NEG32);
+        entry("neg64", AluUnary, ebpf::NEG64);
+
+        // AluBinary.
+        for &(name, opc) in &alu_binary_ops {
+            entry(name, AluBinary, ebpf::BPF_ALU64 | opc);
+            entry(&format!("{name}32"), AluBinary, ebpf::BPF_ALU | opc);
+            entry(&format!("{name}64"), AluBinary, ebpf::BPF_ALU64 | opc);
+        }
+
+        // LoadAbs, LoadInd, LoadReg, StoreImm, and StoreReg.
+        for &(suffix, size) in &mem_sizes {
+            entry(
+                &format!("ldabs{suffix}"),
+                LoadAbs,
+                ebpf::BPF_ABS | ebpf::BPF_LD | size,
+            );
+            entry(
+                &format!("ldind{suffix}"),
+                LoadInd,
+                ebpf::BPF_IND | ebpf::BPF_LD | size,
+            );
+            entry(
+                &format!("ldx{suffix}"),
+                LoadReg,
+                ebpf::BPF_MEM | ebpf::BPF_LDX | size,
+            );
+            entry(
+                &format!("st{suffix}"),
+                StoreImm,
+                ebpf::BPF_MEM | ebpf::BPF_ST | size,
+            );
+            entry(
+                &format!("stx{suffix}"),
+                StoreReg,
+                ebpf::BPF_MEM | ebpf::BPF_STX | size,
+            );
+        }
+
+        // JumpConditional.
+        for &(name, condition) in &jump_conditions {
+            entry(name, JumpConditional, ebpf::BPF_JMP | condition);
+            entry(
+                &format!("{name}32"),
+                JumpConditional,
+                ebpf::BPF_JMP32 | condition,
+            );
+        }
+
+        // Endian.
+        for &size in &[16, 32, 64] {
+            entry(&format!("be{size}"), Endian(size), ebpf::BE);
+            entry(&format!("le{size}"), Endian(size), ebpf::LE);
+        }
+    }
+
+    result
+}
+
+fn insn(opc: u8, dst: i64, src: i64, off: i64, imm: i64) -> Result<Insn, String> {
+    if !(0..16).contains(&dst) {
+        return Err(format!("Invalid destination register {dst}"));
+    }
+    if dst < 0 || src >= 16 {
+        return Err(format!("Invalid source register {src}"));
+    }
+    if !(-32768..32768).contains(&off) {
+        return Err(format!("Invalid offset {off}"));
+    }
+    if !(-2147483648..2147483648).contains(&imm) {
+        return Err(format!("Invalid immediate {imm}"));
+    }
+    Ok(Insn {
+        opc,
+        dst: dst as u8,
+        src: src as u8,
+        off: off as i16,
+        imm: imm as i32,
+    })
+}
+
+// TODO Use slice patterns when available and remove this function.
+fn operands_tuple(operands: &[Operand]) -> Result<(Operand, Operand, Operand), String> {
+    match operands.len() {
+        0 => Ok((Nil, Nil, Nil)),
+        1 => Ok((operands[0], Nil, Nil)),
+        2 => Ok((operands[0], operands[1], Nil)),
+        3 => Ok((operands[0], operands[1], operands[2])),
+        _ => Err("Too many operands".to_string()),
+    }
+}
+
+fn encode(inst_type: InstructionType, opc: u8, operands: &[Operand]) -> Result<Insn, String> {
+    let (a, b, c) = (operands_tuple(operands))?;
+    match (inst_type, a, b, c) {
+        (AluBinary, Register(dst), Register(src), Nil) => insn(opc | ebpf::BPF_X, dst, src, 0, 0),
+        (AluBinary, Register(dst), Integer(imm), Nil) => insn(opc | ebpf::BPF_K, dst, 0, 0, imm),
+        (AluUnary, Register(dst), Nil, Nil) => insn(opc, dst, 0, 0, 0),
+        (LoadAbs, Integer(imm), Nil, Nil) => insn(opc, 0, 0, 0, imm),
+        (LoadInd, Register(src), Integer(imm), Nil) => insn(opc, 0, src, 0, imm),
+        (LoadReg, Register(dst), Memory(src, off), Nil)
+        | (StoreReg, Memory(dst, off), Register(src), Nil) => insn(opc, dst, src, off, 0),
+        (StoreImm, Memory(dst, off), Integer(imm), Nil) => insn(opc, dst, 0, off, imm),
+        (NoOperand, Nil, Nil, Nil) => insn(opc, 0, 0, 0, 0),
+        (JumpUnconditional, Integer(off), Nil, Nil) => insn(opc, 0, 0, off, 0),
+        (JumpConditional, Register(dst), Register(src), Integer(off)) => {
+            insn(opc | ebpf::BPF_X, dst, src, off, 0)
+        }
+        (JumpConditional, Register(dst), Integer(imm), Integer(off)) => {
+            insn(opc | ebpf::BPF_K, dst, 0, off, imm)
+        }
+        (Call, Integer(imm), Nil, Nil) => insn(opc, 0, 0, 0, imm),
+        (Endian(size), Register(dst), Nil, Nil) => insn(opc, dst, 0, 0, size),
+        (LoadImm, Register(dst), Integer(imm), Nil) => insn(opc, dst, 0, 0, (imm << 32) >> 32),
+        _ => Err(format!("Unexpected operands: {operands:?}")),
+    }
+}
+
+fn assemble_internal(parsed: &[Instruction]) -> Result<Vec<Insn>, String> {
+    let instruction_map = make_instruction_map();
+    let mut result: Vec<Insn> = vec![];
+    for instruction in parsed {
+        let name = instruction.name.as_str();
+        match instruction_map.get(name) {
+            Some(&(inst_type, opc)) => {
+                match encode(inst_type, opc, &instruction.operands) {
+                    Ok(insn) => result.push(insn),
+                    Err(msg) => return Err(format!("Failed to encode {name}: {msg}")),
+                }
+                // Special case for lddw.
+                if let LoadImm = inst_type {
+                    if let Integer(imm) = instruction.operands[1] {
+                        result.push(insn(0, 0, 0, 0, imm >> 32).unwrap());
+                    }
+                }
+            }
+            None => return Err(format!("Invalid instruction {name:?}")),
+        }
+    }
+    Ok(result)
+}
+
+/// Parse assembly source and translate to binary.
+///
+/// # Examples
+///
+/// ```
+/// use rbpf::assembler::assemble;
+/// let prog = assemble("add64 r1, 0x605
+///                      mov64 r2, 0x32
+///                      mov64 r1, r0
+///                      be16 r0
+///                      neg64 r2
+///                      exit");
+/// println!("{:?}", prog);
+/// # assert_eq!(prog,
+/// #            Ok(vec![0x07, 0x01, 0x00, 0x00, 0x05, 0x06, 0x00, 0x00,
+/// #                    0xb7, 0x02, 0x00, 0x00, 0x32, 0x00, 0x00, 0x00,
+/// #                    0xbf, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+/// #                    0xdc, 0x00, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00,
+/// #                    0x87, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+/// #                    0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]));
+/// ```
+///
+/// This will produce the following output:
+///
+/// ```test
+/// Ok([0x07, 0x01, 0x00, 0x00, 0x05, 0x06, 0x00, 0x00,
+///     0xb7, 0x02, 0x00, 0x00, 0x32, 0x00, 0x00, 0x00,
+///     0xbf, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+///     0xdc, 0x00, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00,
+///     0x87, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+///     0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00])
+/// ```
+pub fn assemble(src: &str) -> Result<Vec<u8>, String> {
+    let parsed = (parse(src))?;
+    let insns = (assemble_internal(&parsed))?;
+    let mut result: Vec<u8> = vec![];
+    for insn in insns {
+        result.extend_from_slice(&insn.to_array());
+    }
+    Ok(result)
+}

kernel/crates/rbpf/src/disassembler.rs

@@ -0,0 +1,807 @@
+// SPDX-License-Identifier: (Apache-2.0 OR MIT)
+// Copyright 2017 6WIND S.A. <quentin.monnet@6wind.com>
+
+//! Functions in this module are used to handle eBPF programs with a higher level representation,
+//! for example to disassemble the code into a human-readable format.
+
+use alloc::{
+    format,
+    string::{String, ToString},
+    vec,
+    vec::Vec,
+};
+
+use log::warn;
+
+use crate::ebpf;
+
+#[inline]
+fn alu_imm_str(name: &str, insn: &ebpf::Insn) -> String {
+    format!("{name} r{}, {:#x}", insn.dst, insn.imm)
+}
+
+#[inline]
+fn alu_reg_str(name: &str, insn: &ebpf::Insn) -> String {
+    format!("{name} r{}, r{}", insn.dst, insn.src)
+}
+
+#[inline]
+fn byteswap_str(name: &str, insn: &ebpf::Insn) -> String {
+    match insn.imm {
+        16 | 32 | 64 => {}
+        _ => warn!("[Disassembler] Warning: Invalid offset value for {name} insn"),
+    }
+    format!("{name}{} r{}", insn.imm, insn.dst)
+}
+
+#[inline]
+fn ld_st_imm_str(name: &str, insn: &ebpf::Insn) -> String {
+    if insn.off >= 0 {
+        format!("{name} [r{}+{:#x}], {:#x}", insn.dst, insn.off, insn.imm)
+    } else {
+        format!(
+            "{name} [r{}-{:#x}], {:#x}",
+            insn.dst,
+            -(insn.off as isize),
+            insn.imm
+        )
+    }
+}
+
+#[inline]
+fn ld_reg_str(name: &str, insn: &ebpf::Insn) -> String {
+    if insn.off >= 0 {
+        format!("{name} r{}, [r{}+{:#x}]", insn.dst, insn.src, insn.off)
+    } else {
+        format!(
+            "{name} r{}, [r{}-{:#x}]",
+            insn.dst,
+            insn.src,
+            -(insn.off as isize)
+        )
+    }
+}
+
+#[inline]
+fn st_reg_str(name: &str, insn: &ebpf::Insn) -> String {
+    if insn.off >= 0 {
+        format!("{name} [r{}+{:#x}], r{}", insn.dst, insn.off, insn.src)
+    } else {
+        format!(
+            "{name} [r{}-{:#x}], r{}",
+            insn.dst,
+            -(insn.off as isize),
+            insn.src
+        )
+    }
+}
+
+#[inline]
+fn ldabs_str(name: &str, insn: &ebpf::Insn) -> String {
+    format!("{name} {:#x}", insn.imm)
+}
+
+#[inline]
+fn ldind_str(name: &str, insn: &ebpf::Insn) -> String {
+    format!("{name} r{}, {:#x}", insn.src, insn.imm)
+}
+
+#[inline]
+fn jmp_imm_str(name: &str, insn: &ebpf::Insn) -> String {
+    if insn.off >= 0 {
+        format!("{name} r{}, {:#x}, +{:#x}", insn.dst, insn.imm, insn.off)
+    } else {
+        format!(
+            "{name} r{}, {:#x}, -{:#x}",
+            insn.dst,
+            insn.imm,
+            -(insn.off as isize)
+        )
+    }
+}
+
+#[inline]
+fn jmp_reg_str(name: &str, insn: &ebpf::Insn) -> String {
+    if insn.off >= 0 {
+        format!("{name} r{}, r{}, +{:#x}", insn.dst, insn.src, insn.off)
+    } else {
+        format!(
+            "{name} r{}, r{}, -{:#x}",
+            insn.dst,
+            insn.src,
+            -(insn.off as isize)
+        )
+    }
+}
+
+/// High-level representation of an eBPF instruction.
+///
+/// In addition to standard operation code and various operand, this struct has the following
+/// properties:
+///
+/// * It stores a name, corresponding to a mnemonic for the operation code.
+/// * It also stores a description, which is a mnemonic for the full instruction, using the actual
+///   values of the relevant operands, and that can be used for disassembling the eBPF program for
+///   example.
+/// * Immediate values are stored in an `i64` instead of a traditional i32, in order to merge the
+///   two parts of (otherwise double-length) `LD_DW_IMM` instructions.
+///
+/// See <https://www.kernel.org/doc/Documentation/networking/filter.txt> for the Linux kernel
+/// documentation about eBPF, or <https://github.com/iovisor/bpf-docs/blob/master/eBPF.md> for a
+/// more concise version.
+#[derive(Debug, PartialEq, Eq)]
+pub struct HLInsn {
+    /// Operation code.
+    pub opc: u8,
+    /// Name (mnemonic). This name is not canon.
+    pub name: String,
+    /// Description of the instruction. This is not canon.
+    pub desc: String,
+    /// Destination register operand.
+    pub dst: u8,
+    /// Source register operand.
+    pub src: u8,
+    /// Offset operand.
+    pub off: i16,
+    /// Immediate value operand. For `LD_DW_IMM` instructions, contains the whole value merged from
+    /// the two 8-bytes parts of the instruction.
+    pub imm: i64,
+}
+
+/// Return a vector of `struct HLInsn` built from an eBPF program.
+///
+/// This is made public to provide a way to manipulate a program as a vector of instructions, in a
+/// high-level format, for example for dumping the program instruction after instruction with a
+/// custom format.
+///
+/// Note that the two parts of `LD_DW_IMM` instructions (that have the size of two standard
+/// instructions) are considered as making a single immediate value. As a consequence, the number
+/// of instructions stored in the vector may not be equal to the size in bytes of the program
+/// divided by the length of an instructions.
+///
+/// To do so, the immediate value operand is stored as an `i64` instead as an i32, so be careful
+/// when you use it (see example `examples/to_json.rs`).
+///
+/// This is to oppose to `ebpf::to_insn_vec()` function, that treats instructions on a low-level
+/// ground and do not merge the parts of `LD_DW_IMM`. Also, the version in `ebpf` module does not
+/// use names or descriptions when storing the instructions.
+///
+/// # Examples
+///
+/// ```
+/// use rbpf::disassembler;
+///
+/// let prog = &[
+///     0x18, 0x00, 0x00, 0x00, 0x88, 0x77, 0x66, 0x55,
+///     0x00, 0x00, 0x00, 0x00, 0x44, 0x33, 0x22, 0x11,
+///     0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+/// ];
+///
+/// let v = disassembler::to_insn_vec(prog);
+/// assert_eq!(v, vec![
+///     disassembler::HLInsn {
+///         opc: 0x18,
+///         name: "lddw".to_string(),
+///         desc: "lddw r0, 0x1122334455667788".to_string(),
+///         dst: 0,
+///         src: 0,
+///         off: 0,
+///         imm: 0x1122334455667788
+///     },
+///     disassembler::HLInsn {
+///         opc: 0x95,
+///         name: "exit".to_string(),
+///         desc: "exit".to_string(),
+///         dst: 0,
+///         src: 0,
+///         off: 0,
+///         imm: 0
+///     },
+/// ]);
+/// ```
+pub fn to_insn_vec(prog: &[u8]) -> Vec<HLInsn> {
+    if prog.len() % ebpf::INSN_SIZE != 0 {
+        panic!(
+            "[Disassembler] Error: eBPF program length must be a multiple of {:?} octets",
+            ebpf::INSN_SIZE
+        );
+    }
+    if prog.is_empty() {
+        return vec![];
+    }
+
+    let mut res = vec![];
+    let mut insn_ptr: usize = 0;
+
+    while insn_ptr * ebpf::INSN_SIZE < prog.len() {
+        let insn = ebpf::get_insn(prog, insn_ptr);
+
+        let name;
+        let desc;
+        let mut imm = insn.imm as i64;
+        match insn.opc {
+            // BPF_LD class
+            ebpf::LD_ABS_B => {
+                name = "ldabsb";
+                desc = ldabs_str(name, &insn);
+            }
+            ebpf::LD_ABS_H => {
+                name = "ldabsh";
+                desc = ldabs_str(name, &insn);
+            }
+            ebpf::LD_ABS_W => {
+                name = "ldabsw";
+                desc = ldabs_str(name, &insn);
+            }
+            ebpf::LD_ABS_DW => {
+                name = "ldabsdw";
+                desc = ldabs_str(name, &insn);
+            }
+            ebpf::LD_IND_B => {
+                name = "ldindb";
+                desc = ldind_str(name, &insn);
+            }
+            ebpf::LD_IND_H => {
+                name = "ldindh";
+                desc = ldind_str(name, &insn);
+            }
+            ebpf::LD_IND_W => {
+                name = "ldindw";
+                desc = ldind_str(name, &insn);
+            }
+            ebpf::LD_IND_DW => {
+                name = "ldinddw";
+                desc = ldind_str(name, &insn);
+            }
+
+            ebpf::LD_DW_IMM => {
+                insn_ptr += 1;
+                let next_insn = ebpf::get_insn(prog, insn_ptr);
+                imm = ((insn.imm as u32) as u64 + ((next_insn.imm as u64) << 32)) as i64;
+                name = "lddw";
+                desc = format!("{name} r{:}, {imm:#x}", insn.dst);
+            }
+
+            // BPF_LDX class
+            ebpf::LD_B_REG => {
+                name = "ldxb";
+                desc = ld_reg_str(name, &insn);
+            }
+            ebpf::LD_H_REG => {
+                name = "ldxh";
+                desc = ld_reg_str(name, &insn);
+            }
+            ebpf::LD_W_REG => {
+                name = "ldxw";
+                desc = ld_reg_str(name, &insn);
+            }
+            ebpf::LD_DW_REG => {
+                name = "ldxdw";
+                desc = ld_reg_str(name, &insn);
+            }
+
+            // BPF_ST class
+            ebpf::ST_B_IMM => {
+                name = "stb";
+                desc = ld_st_imm_str(name, &insn);
+            }
+            ebpf::ST_H_IMM => {
+                name = "sth";
+                desc = ld_st_imm_str(name, &insn);
+            }
+            ebpf::ST_W_IMM => {
+                name = "stw";
+                desc = ld_st_imm_str(name, &insn);
+            }
+            ebpf::ST_DW_IMM => {
+                name = "stdw";
+                desc = ld_st_imm_str(name, &insn);
+            }
+
+            // BPF_STX class
+            ebpf::ST_B_REG => {
+                name = "stxb";
+                desc = st_reg_str(name, &insn);
+            }
+            ebpf::ST_H_REG => {
+                name = "stxh";
+                desc = st_reg_str(name, &insn);
+            }
+            ebpf::ST_W_REG => {
+                name = "stxw";
+                desc = st_reg_str(name, &insn);
+            }
+            ebpf::ST_DW_REG => {
+                name = "stxdw";
+                desc = st_reg_str(name, &insn);
+            }
+            ebpf::ST_W_XADD => {
+                name = "stxxaddw";
+                desc = st_reg_str(name, &insn);
+            }
+            ebpf::ST_DW_XADD => {
+                name = "stxxadddw";
+                desc = st_reg_str(name, &insn);
+            }
+
+            // BPF_ALU class
+            ebpf::ADD32_IMM => {
+                name = "add32";
+                desc = alu_imm_str(name, &insn);
+            }
+            ebpf::ADD32_REG => {
+                name = "add32";
+                desc = alu_reg_str(name, &insn);
+            }
+            ebpf::SUB32_IMM => {
+                name = "sub32";
+                desc = alu_imm_str(name, &insn);
+            }
+            ebpf::SUB32_REG => {
+                name = "sub32";
+                desc = alu_reg_str(name, &insn);
+            }
+            ebpf::MUL32_IMM => {
+                name = "mul32";
+                desc = alu_imm_str(name, &insn);
+            }
+            ebpf::MUL32_REG => {
+                name = "mul32";
+                desc = alu_reg_str(name, &insn);
+            }
+            ebpf::DIV32_IMM => {
+                name = "div32";
+                desc = alu_imm_str(name, &insn);
+            }
+            ebpf::DIV32_REG => {
+                name = "div32";
+                desc = alu_reg_str(name, &insn);
+            }
+            ebpf::OR32_IMM => {
+                name = "or32";
+                desc = alu_imm_str(name, &insn);
+            }
+            ebpf::OR32_REG => {
+                name = "or32";
+                desc = alu_reg_str(name, &insn);
+            }
+            ebpf::AND32_IMM => {
+                name = "and32";
+                desc = alu_imm_str(name, &insn);
+            }
+            ebpf::AND32_REG => {
+                name = "and32";
+                desc = alu_reg_str(name, &insn);
+            }
+            ebpf::LSH32_IMM => {
+                name = "lsh32";
+                desc = alu_imm_str(name, &insn);
+            }
+            ebpf::LSH32_REG => {
+                name = "lsh32";
+                desc = alu_reg_str(name, &insn);
+            }
+            ebpf::RSH32_IMM => {
+                name = "rsh32";
+                desc = alu_imm_str(name, &insn);
+            }
+            ebpf::RSH32_REG => {
+                name = "rsh32";
+                desc = alu_reg_str(name, &insn);
+            }
+            ebpf::NEG32 => {
+                name = "neg32";
+                desc = format!("{name} r{:}", insn.dst);
+            }
+            ebpf::MOD32_IMM => {
+                name = "mod32";
+                desc = alu_imm_str(name, &insn);
+            }
+            ebpf::MOD32_REG => {
+                name = "mod32";
+                desc = alu_reg_str(name, &insn);
+            }
+            ebpf::XOR32_IMM => {
+                name = "xor32";
+                desc = alu_imm_str(name, &insn);
+            }
+            ebpf::XOR32_REG => {
+                name = "xor32";
+                desc = alu_reg_str(name, &insn);
+            }
+            ebpf::MOV32_IMM => {
+                name = "mov32";
+                desc = alu_imm_str(name, &insn);
+            }
+            ebpf::MOV32_REG => {
+                name = "mov32";
+                desc = alu_reg_str(name, &insn);
+            }
+            ebpf::ARSH32_IMM => {
+                name = "arsh32";
+                desc = alu_imm_str(name, &insn);
+            }
+            ebpf::ARSH32_REG => {
+                name = "arsh32";
+                desc = alu_reg_str(name, &insn);
+            }
+            ebpf::LE => {
+                name = "le";
+                desc = byteswap_str(name, &insn);
+            }
+            ebpf::BE => {
+                name = "be";
+                desc = byteswap_str(name, &insn);
+            }
+
+            // BPF_ALU64 class
+            ebpf::ADD64_IMM => {
+                name = "add64";
+                desc = alu_imm_str(name, &insn);
+            }
+            ebpf::ADD64_REG => {
+                name = "add64";
+                desc = alu_reg_str(name, &insn);
+            }
+            ebpf::SUB64_IMM => {
+                name = "sub64";
+                desc = alu_imm_str(name, &insn);
+            }
+            ebpf::SUB64_REG => {
+                name = "sub64";
+                desc = alu_reg_str(name, &insn);
+            }
+            ebpf::MUL64_IMM => {
+                name = "mul64";
+                desc = alu_imm_str(name, &insn);
+            }
+            ebpf::MUL64_REG => {
+                name = "mul64";
+                desc = alu_reg_str(name, &insn);
+            }
+            ebpf::DIV64_IMM => {
+                name = "div64";
+                desc = alu_imm_str(name, &insn);
+            }
+            ebpf::DIV64_REG => {
+                name = "div64";
+                desc = alu_reg_str(name, &insn);
+            }
+            ebpf::OR64_IMM => {
+                name = "or64";
+                desc = alu_imm_str(name, &insn);
+            }
+            ebpf::OR64_REG => {
+                name = "or64";
+                desc = alu_reg_str(name, &insn);
+            }
+            ebpf::AND64_IMM => {
+                name = "and64";
+                desc = alu_imm_str(name, &insn);
+            }
+            ebpf::AND64_REG => {
+                name = "and64";
+                desc = alu_reg_str(name, &insn);
+            }
+            ebpf::LSH64_IMM => {
+                name = "lsh64";
+                desc = alu_imm_str(name, &insn);
+            }
+            ebpf::LSH64_REG => {
+                name = "lsh64";
+                desc = alu_reg_str(name, &insn);
+            }
+            ebpf::RSH64_IMM => {
+                name = "rsh64";
+                desc = alu_imm_str(name, &insn);
+            }
+            ebpf::RSH64_REG => {
+                name = "rsh64";
+                desc = alu_reg_str(name, &insn);
+            }
+            ebpf::NEG64 => {
+                name = "neg64";
+                desc = format!("{name} r{:}", insn.dst);
+            }
+            ebpf::MOD64_IMM => {
+                name = "mod64";
+                desc = alu_imm_str(name, &insn);
+            }
+            ebpf::MOD64_REG => {
+                name = "mod64";
+                desc = alu_reg_str(name, &insn);
+            }
+            ebpf::XOR64_IMM => {
+                name = "xor64";
+                desc = alu_imm_str(name, &insn);
+            }
+            ebpf::XOR64_REG => {
+                name = "xor64";
+                desc = alu_reg_str(name, &insn);
+            }
+            ebpf::MOV64_IMM => {
+                name = "mov64";
+                desc = alu_imm_str(name, &insn);
+            }
+            ebpf::MOV64_REG => {
+                name = "mov64";
+                desc = alu_reg_str(name, &insn);
+            }
+            ebpf::ARSH64_IMM => {
+                name = "arsh64";
+                desc = alu_imm_str(name, &insn);
+            }
+            ebpf::ARSH64_REG => {
+                name = "arsh64";
+                desc = alu_reg_str(name, &insn);
+            }
+
+            // BPF_JMP class
+            ebpf::JA => {
+                name = "ja";
+                desc = if insn.off >= 0 {
+                    format!("{name} +{:#x}", insn.off)
+                } else {
+                    format!("{name} -{:#x}", -insn.off)
+                }
+            }
+            ebpf::JEQ_IMM => {
+                name = "jeq";
+                desc = jmp_imm_str(name, &insn);
+            }
+            ebpf::JEQ_REG => {
+                name = "jeq";
+                desc = jmp_reg_str(name, &insn);
+            }
+            ebpf::JGT_IMM => {
+                name = "jgt";
+                desc = jmp_imm_str(name, &insn);
+            }
+            ebpf::JGT_REG => {
+                name = "jgt";
+                desc = jmp_reg_str(name, &insn);
+            }
+            ebpf::JGE_IMM => {
+                name = "jge";
+                desc = jmp_imm_str(name, &insn);
+            }
+            ebpf::JGE_REG => {
+                name = "jge";
+                desc = jmp_reg_str(name, &insn);
+            }
+            ebpf::JLT_IMM => {
+                name = "jlt";
+                desc = jmp_imm_str(name, &insn);
+            }
+            ebpf::JLT_REG => {
+                name = "jlt";
+                desc = jmp_reg_str(name, &insn);
+            }
+            ebpf::JLE_IMM => {
+                name = "jle";
+                desc = jmp_imm_str(name, &insn);
+            }
+            ebpf::JLE_REG => {
+                name = "jle";
+                desc = jmp_reg_str(name, &insn);
+            }
+            ebpf::JSET_IMM => {
+                name = "jset";
+                desc = jmp_imm_str(name, &insn);
+            }
+            ebpf::JSET_REG => {
+                name = "jset";
+                desc = jmp_reg_str(name, &insn);
+            }
+            ebpf::JNE_IMM => {
+                name = "jne";
+                desc = jmp_imm_str(name, &insn);
+            }
+            ebpf::JNE_REG => {
+                name = "jne";
+                desc = jmp_reg_str(name, &insn);
+            }
+            ebpf::JSGT_IMM => {
+                name = "jsgt";
+                desc = jmp_imm_str(name, &insn);
+            }
+            ebpf::JSGT_REG => {
+                name = "jsgt";
+                desc = jmp_reg_str(name, &insn);
+            }
+            ebpf::JSGE_IMM => {
+                name = "jsge";
+                desc = jmp_imm_str(name, &insn);
+            }
+            ebpf::JSGE_REG => {
+                name = "jsge";
+                desc = jmp_reg_str(name, &insn);
+            }
+            ebpf::JSLT_IMM => {
+                name = "jslt";
+                desc = jmp_imm_str(name, &insn);
+            }
+            ebpf::JSLT_REG => {
+                name = "jslt";
+                desc = jmp_reg_str(name, &insn);
+            }
+            ebpf::JSLE_IMM => {
+                name = "jsle";
+                desc = jmp_imm_str(name, &insn);
+            }
+            ebpf::JSLE_REG => {
+                name = "jsle";
+                desc = jmp_reg_str(name, &insn);
+            }
+            ebpf::CALL => {
+                name = "call";
+                desc = format!("{name} {:#x}", insn.imm);
+            }
+            ebpf::TAIL_CALL => {
+                name = "tail_call";
+                desc = name.to_string();
+            }
+            ebpf::EXIT => {
+                name = "exit";
+                desc = name.to_string();
+            }
+
+            // BPF_JMP32 class
+            ebpf::JEQ_IMM32 => {
+                name = "jeq32";
+                desc = jmp_imm_str(name, &insn);
+            }
+            ebpf::JEQ_REG32 => {
+                name = "jeq32";
+                desc = jmp_reg_str(name, &insn);
+            }
+            ebpf::JGT_IMM32 => {
+                name = "jgt32";
+                desc = jmp_imm_str(name, &insn);
+            }
+            ebpf::JGT_REG32 => {
+                name = "jgt32";
+                desc = jmp_reg_str(name, &insn);
+            }
+            ebpf::JGE_IMM32 => {
+                name = "jge32";
+                desc = jmp_imm_str(name, &insn);
+            }
+            ebpf::JGE_REG32 => {
+                name = "jge32";
+                desc = jmp_reg_str(name, &insn);
+            }
+            ebpf::JLT_IMM32 => {
+                name = "jlt32";
+                desc = jmp_imm_str(name, &insn);
+            }
+            ebpf::JLT_REG32 => {
+                name = "jlt32";
+                desc = jmp_reg_str(name, &insn);
+            }
+            ebpf::JLE_IMM32 => {
+                name = "jle32";
+                desc = jmp_imm_str(name, &insn);
+            }
+            ebpf::JLE_REG32 => {
+                name = "jle32";
+                desc = jmp_reg_str(name, &insn);
+            }
+            ebpf::JSET_IMM32 => {
+                name = "jset32";
+                desc = jmp_imm_str(name, &insn);
+            }
+            ebpf::JSET_REG32 => {
+                name = "jset32";
+                desc = jmp_reg_str(name, &insn);
+            }
+            ebpf::JNE_IMM32 => {
+                name = "jne32";
+                desc = jmp_imm_str(name, &insn);
+            }
+            ebpf::JNE_REG32 => {
+                name = "jne32";
+                desc = jmp_reg_str(name, &insn);
+            }
+            ebpf::JSGT_IMM32 => {
+                name = "jsgt32";
+                desc = jmp_imm_str(name, &insn);
+            }
+            ebpf::JSGT_REG32 => {
+                name = "jsgt32";
+                desc = jmp_reg_str(name, &insn);
+            }
+            ebpf::JSGE_IMM32 => {
+                name = "jsge32";
+                desc = jmp_imm_str(name, &insn);
+            }
+            ebpf::JSGE_REG32 => {
+                name = "jsge32";
+                desc = jmp_reg_str(name, &insn);
+            }
+            ebpf::JSLT_IMM32 => {
+                name = "jslt32";
+                desc = jmp_imm_str(name, &insn);
+            }
+            ebpf::JSLT_REG32 => {
+                name = "jslt32";
+                desc = jmp_reg_str(name, &insn);
+            }
+            ebpf::JSLE_IMM32 => {
+                name = "jsle32";
+                desc = jmp_imm_str(name, &insn);
+            }
+            ebpf::JSLE_REG32 => {
+                name = "jsle32";
+                desc = jmp_reg_str(name, &insn);
+            }
+
+            _ => {
+                panic!(
+                    "[Disassembler] Error: unknown eBPF opcode {:#2x} (insn #{:?})",
+                    insn.opc, insn_ptr
+                );
+            }
+        };
+
+        let hl_insn = HLInsn {
+            opc: insn.opc,
+            name: name.to_string(),
+            desc,
+            dst: insn.dst,
+            src: insn.src,
+            off: insn.off,
+            imm,
+        };
+
+        res.push(hl_insn);
+
+        insn_ptr += 1;
+    }
+    res
+}
+
+/// Disassemble an eBPF program into human-readable instructions and prints it to standard output.
+///
+/// The program is not checked for errors or inconsistencies.
+///
+/// # Examples
+///
+/// ```
+/// use rbpf::disassembler;
+/// let prog = &[
+///     0x07, 0x01, 0x00, 0x00, 0x05, 0x06, 0x00, 0x00,
+///     0xb7, 0x02, 0x00, 0x00, 0x32, 0x00, 0x00, 0x00,
+///     0xbf, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+///     0xdc, 0x00, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00,
+///     0x87, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+///     0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+/// ];
+/// disassembler::disassemble(prog);
+/// # // "\nadd64 r1, 0x605\nmov64 r2, 0x32\nmov64 r1, r0\nbe16 r0\nneg64 r2\nexit"
+/// ```
+///
+/// This will produce the following output:
+///
+/// ```test
+/// add64 r1, 0x605
+/// mov64 r2, 0x32
+/// mov64 r1, r0
+/// be16 r0
+/// neg64 r2
+/// exit
+/// ```
+pub fn disassemble(prog: &[u8]) {
+    #[cfg(feature = "std")]
+    {
+        for insn in to_insn_vec(prog) {
+            println!("{}", insn.desc);
+        }
+    }
+    #[cfg(not(feature = "std"))]
+    {
+        for insn in to_insn_vec(prog) {
+            log::info!("{}", insn.desc);
+        }
+    }
+}

kernel/crates/rbpf/src/ebpf.rs

@@ -0,0 +1,635 @@
+// SPDX-License-Identifier: (Apache-2.0 OR MIT)
+// Copyright 2016 6WIND S.A. <quentin.monnet@6wind.com>
+
+//! This module contains all the definitions related to eBPF, and some functions permitting to
+//! manipulate eBPF instructions.
+//!
+//! The number of bytes in an instruction, the maximum number of instructions in a program, and
+//! also all operation codes are defined here as constants.
+//!
+//! The structure for an instruction used by this crate, as well as the function to extract it from
+//! a program, is also defined in the module.
+//!
+//! To learn more about these instructions, see the Linux kernel documentation:
+//! <https://www.kernel.org/doc/Documentation/networking/filter.txt>, or for a shorter version of
+//! the list of the operation codes: <https://github.com/iovisor/bpf-docs/blob/master/eBPF.md>
+
+use alloc::{vec, vec::Vec};
+
+use byteorder::{ByteOrder, LittleEndian};
+
+/// The maximum call depth is 8
+pub const RBPF_MAX_CALL_DEPTH: usize = 8;
+
+/// Maximum number of instructions in an eBPF program.
+pub const PROG_MAX_INSNS: usize = 1000000;
+/// Size of an eBPF instructions, in bytes.
+pub const INSN_SIZE: usize = 8;
+/// Maximum size of an eBPF program, in bytes.
+pub const PROG_MAX_SIZE: usize = PROG_MAX_INSNS * INSN_SIZE;
+/// Stack for the eBPF stack, in bytes.
+pub const STACK_SIZE: usize = 512;
+
+// eBPF op codes.
+// See also https://www.kernel.org/doc/Documentation/networking/filter.txt
+
+// Three least significant bits are operation class:
+/// BPF operation class: load from immediate.
+pub const BPF_LD: u8 = 0x00;
+/// BPF operation class: load from register.
+pub const BPF_LDX: u8 = 0x01;
+/// BPF operation class: store immediate.
+pub const BPF_ST: u8 = 0x02;
+/// BPF operation class: store value from register.
+pub const BPF_STX: u8 = 0x03;
+/// BPF operation class: 32 bits arithmetic operation.
+pub const BPF_ALU: u8 = 0x04;
+/// BPF operation class: jump (64-bit wide operands for comparisons).
+pub const BPF_JMP: u8 = 0x05;
+/// BPF operation class: jump (32-bit wide operands for comparisons).
+pub const BPF_JMP32: u8 = 0x06;
+// [ class 6 unused, reserved for future use ]
+/// BPF operation class: 64 bits arithmetic operation.
+pub const BPF_ALU64: u8 = 0x07;
+
+// For load and store instructions:
+// +------------+--------+------------+
+// |   3 bits   | 2 bits |   3 bits   |
+// |    mode    |  size  | insn class |
+// +------------+--------+------------+
+// (MSB)                          (LSB)
+
+// Size modifiers:
+/// BPF size modifier: word (4 bytes).
+pub const BPF_W: u8 = 0x00;
+/// BPF size modifier: half-word (2 bytes).
+pub const BPF_H: u8 = 0x08;
+/// BPF size modifier: byte (1 byte).
+pub const BPF_B: u8 = 0x10;
+/// BPF size modifier: double word (8 bytes).
+pub const BPF_DW: u8 = 0x18;
+
+// Mode modifiers:
+/// BPF mode modifier: immediate value.
+pub const BPF_IMM: u8 = 0x00;
+/// BPF mode modifier: absolute load.
+pub const BPF_ABS: u8 = 0x20;
+/// BPF mode modifier: indirect load.
+pub const BPF_IND: u8 = 0x40;
+/// BPF mode modifier: load from / store to memory.
+pub const BPF_MEM: u8 = 0x60;
+// [ 0x80 reserved ]
+// [ 0xa0 reserved ]
+/// BPF mode modifier: exclusive add.
+pub const BPF_XADD: u8 = 0xc0;
+
+// For arithmetic (BPF_ALU/BPF_ALU64) and jump (BPF_JMP) instructions:
+// +----------------+--------+--------+
+// |     4 bits     |1 b.|   3 bits   |
+// | operation code | src| insn class |
+// +----------------+----+------------+
+// (MSB)                          (LSB)
+
+// Source modifiers:
+/// BPF source operand modifier: 32-bit immediate value.
+pub const BPF_K: u8 = 0x00;
+/// BPF source operand modifier: `src` register.
+pub const BPF_X: u8 = 0x08;
+
+// Operation codes -- BPF_ALU or BPF_ALU64 classes:
+/// BPF ALU/ALU64 operation code: addition.
+pub const BPF_ADD: u8 = 0x00;
+/// BPF ALU/ALU64 operation code: subtraction.
+pub const BPF_SUB: u8 = 0x10;
+/// BPF ALU/ALU64 operation code: multiplication.
+pub const BPF_MUL: u8 = 0x20;
+/// BPF ALU/ALU64 operation code: division.
+pub const BPF_DIV: u8 = 0x30;
+/// BPF ALU/ALU64 operation code: or.
+pub const BPF_OR: u8 = 0x40;
+/// BPF ALU/ALU64 operation code: and.
+pub const BPF_AND: u8 = 0x50;
+/// BPF ALU/ALU64 operation code: left shift.
+pub const BPF_LSH: u8 = 0x60;
+/// BPF ALU/ALU64 operation code: right shift.
+pub const BPF_RSH: u8 = 0x70;
+/// BPF ALU/ALU64 operation code: negation.
+pub const BPF_NEG: u8 = 0x80;
+/// BPF ALU/ALU64 operation code: modulus.
+pub const BPF_MOD: u8 = 0x90;
+/// BPF ALU/ALU64 operation code: exclusive or.
+pub const BPF_XOR: u8 = 0xa0;
+/// BPF ALU/ALU64 operation code: move.
+pub const BPF_MOV: u8 = 0xb0;
+/// BPF ALU/ALU64 operation code: sign extending right shift.
+pub const BPF_ARSH: u8 = 0xc0;
+/// BPF ALU/ALU64 operation code: endianness conversion.
+pub const BPF_END: u8 = 0xd0;
+
+// Operation codes -- BPF_JMP or BPF_JMP32 classes:
+/// BPF JMP operation code: jump.
+pub const BPF_JA: u8 = 0x00;
+/// BPF JMP operation code: jump if equal.
+pub const BPF_JEQ: u8 = 0x10;
+/// BPF JMP operation code: jump if greater than.
+pub const BPF_JGT: u8 = 0x20;
+/// BPF JMP operation code: jump if greater or equal.
+pub const BPF_JGE: u8 = 0x30;
+/// BPF JMP operation code: jump if `src` & `reg`.
+pub const BPF_JSET: u8 = 0x40;
+/// BPF JMP operation code: jump if not equal.
+pub const BPF_JNE: u8 = 0x50;
+/// BPF JMP operation code: jump if greater than (signed).
+pub const BPF_JSGT: u8 = 0x60;
+/// BPF JMP operation code: jump if greater or equal (signed).
+pub const BPF_JSGE: u8 = 0x70;
+/// BPF JMP operation code: helper function call.
+pub const BPF_CALL: u8 = 0x80;
+/// BPF JMP operation code: return from program.
+pub const BPF_EXIT: u8 = 0x90;
+/// BPF JMP operation code: jump if lower than.
+pub const BPF_JLT: u8 = 0xa0;
+/// BPF JMP operation code: jump if lower or equal.
+pub const BPF_JLE: u8 = 0xb0;
+/// BPF JMP operation code: jump if lower than (signed).
+pub const BPF_JSLT: u8 = 0xc0;
+/// BPF JMP operation code: jump if lower or equal (signed).
+pub const BPF_JSLE: u8 = 0xd0;
+
+// Op codes
+// (Following operation names are not “official”, but may be proper to rbpf; Linux kernel only
+// combines above flags and does not attribute a name per operation.)
+
+/// BPF opcode: `ldabsb src, dst, imm`.
+pub const LD_ABS_B: u8 = BPF_LD | BPF_ABS | BPF_B;
+/// BPF opcode: `ldabsh src, dst, imm`.
+pub const LD_ABS_H: u8 = BPF_LD | BPF_ABS | BPF_H;
+/// BPF opcode: `ldabsw src, dst, imm`.
+pub const LD_ABS_W: u8 = BPF_LD | BPF_ABS | BPF_W;
+/// BPF opcode: `ldabsdw src, dst, imm`.
+pub const LD_ABS_DW: u8 = BPF_LD | BPF_ABS | BPF_DW;
+/// BPF opcode: `ldindb src, dst, imm`.
+pub const LD_IND_B: u8 = BPF_LD | BPF_IND | BPF_B;
+/// BPF opcode: `ldindh src, dst, imm`.
+pub const LD_IND_H: u8 = BPF_LD | BPF_IND | BPF_H;
+/// BPF opcode: `ldindw src, dst, imm`.
+pub const LD_IND_W: u8 = BPF_LD | BPF_IND | BPF_W;
+/// BPF opcode: `ldinddw src, dst, imm`.
+pub const LD_IND_DW: u8 = BPF_LD | BPF_IND | BPF_DW;
+
+#[allow(unknown_lints)]
+#[allow(clippy::eq_op)]
+/// BPF opcode: `lddw dst, imm` /// `dst = imm`.
+pub const LD_DW_IMM: u8 = BPF_LD | BPF_IMM | BPF_DW;
+/// BPF opcode: `ldxb dst, [src + off]` /// `dst = (src + off) as u8`.
+pub const LD_B_REG: u8 = BPF_LDX | BPF_MEM | BPF_B;
+/// BPF opcode: `ldxh dst, [src + off]` /// `dst = (src + off) as u16`.
+pub const LD_H_REG: u8 = BPF_LDX | BPF_MEM | BPF_H;
+/// BPF opcode: `ldxw dst, [src + off]` /// `dst = (src + off) as u32`.
+pub const LD_W_REG: u8 = BPF_LDX | BPF_MEM | BPF_W;
+/// BPF opcode: `ldxdw dst, [src + off]` /// `dst = (src + off) as u64`.
+pub const LD_DW_REG: u8 = BPF_LDX | BPF_MEM | BPF_DW;
+/// BPF opcode: `stb [dst + off], imm` /// `(dst + offset) as u8 = imm`.
+pub const ST_B_IMM: u8 = BPF_ST | BPF_MEM | BPF_B;
+/// BPF opcode: `sth [dst + off], imm` /// `(dst + offset) as u16 = imm`.
+pub const ST_H_IMM: u8 = BPF_ST | BPF_MEM | BPF_H;
+/// BPF opcode: `stw [dst + off], imm` /// `(dst + offset) as u32 = imm`.
+pub const ST_W_IMM: u8 = BPF_ST | BPF_MEM | BPF_W;
+/// BPF opcode: `stdw [dst + off], imm` /// `(dst + offset) as u64 = imm`.
+pub const ST_DW_IMM: u8 = BPF_ST | BPF_MEM | BPF_DW;
+/// BPF opcode: `stxb [dst + off], src` /// `(dst + offset) as u8 = src`.
+pub const ST_B_REG: u8 = BPF_STX | BPF_MEM | BPF_B;
+/// BPF opcode: `stxh [dst + off], src` /// `(dst + offset) as u16 = src`.
+pub const ST_H_REG: u8 = BPF_STX | BPF_MEM | BPF_H;
+/// BPF opcode: `stxw [dst + off], src` /// `(dst + offset) as u32 = src`.
+pub const ST_W_REG: u8 = BPF_STX | BPF_MEM | BPF_W;
+/// BPF opcode: `stxdw [dst + off], src` /// `(dst + offset) as u64 = src`.
+pub const ST_DW_REG: u8 = BPF_STX | BPF_MEM | BPF_DW;
+
+/// BPF opcode: `stxxaddw [dst + off], src`.
+pub const ST_W_XADD: u8 = BPF_STX | BPF_XADD | BPF_W;
+/// BPF opcode: `stxxadddw [dst + off], src`.
+pub const ST_DW_XADD: u8 = BPF_STX | BPF_XADD | BPF_DW;
+
+/// BPF opcode: `add32 dst, imm` /// `dst += imm`.
+pub const ADD32_IMM: u8 = BPF_ALU | BPF_K | BPF_ADD;
+/// BPF opcode: `add32 dst, src` /// `dst += src`.
+pub const ADD32_REG: u8 = BPF_ALU | BPF_X | BPF_ADD;
+/// BPF opcode: `sub32 dst, imm` /// `dst -= imm`.
+pub const SUB32_IMM: u8 = BPF_ALU | BPF_K | BPF_SUB;
+/// BPF opcode: `sub32 dst, src` /// `dst -= src`.
+pub const SUB32_REG: u8 = BPF_ALU | BPF_X | BPF_SUB;
+/// BPF opcode: `mul32 dst, imm` /// `dst *= imm`.
+pub const MUL32_IMM: u8 = BPF_ALU | BPF_K | BPF_MUL;
+/// BPF opcode: `mul32 dst, src` /// `dst *= src`.
+pub const MUL32_REG: u8 = BPF_ALU | BPF_X | BPF_MUL;
+/// BPF opcode: `div32 dst, imm` /// `dst /= imm`.
+pub const DIV32_IMM: u8 = BPF_ALU | BPF_K | BPF_DIV;
+/// BPF opcode: `div32 dst, src` /// `dst /= src`.
+pub const DIV32_REG: u8 = BPF_ALU | BPF_X | BPF_DIV;
+/// BPF opcode: `or32 dst, imm` /// `dst |= imm`.
+pub const OR32_IMM: u8 = BPF_ALU | BPF_K | BPF_OR;
+/// BPF opcode: `or32 dst, src` /// `dst |= src`.
+pub const OR32_REG: u8 = BPF_ALU | BPF_X | BPF_OR;
+/// BPF opcode: `and32 dst, imm` /// `dst &= imm`.
+pub const AND32_IMM: u8 = BPF_ALU | BPF_K | BPF_AND;
+/// BPF opcode: `and32 dst, src` /// `dst &= src`.
+pub const AND32_REG: u8 = BPF_ALU | BPF_X | BPF_AND;
+/// BPF opcode: `lsh32 dst, imm` /// `dst <<= imm`.
+pub const LSH32_IMM: u8 = BPF_ALU | BPF_K | BPF_LSH;
+/// BPF opcode: `lsh32 dst, src` /// `dst <<= src`.
+pub const LSH32_REG: u8 = BPF_ALU | BPF_X | BPF_LSH;
+/// BPF opcode: `rsh32 dst, imm` /// `dst >>= imm`.
+pub const RSH32_IMM: u8 = BPF_ALU | BPF_K | BPF_RSH;
+/// BPF opcode: `rsh32 dst, src` /// `dst >>= src`.
+pub const RSH32_REG: u8 = BPF_ALU | BPF_X | BPF_RSH;
+/// BPF opcode: `neg32 dst` /// `dst = -dst`.
+pub const NEG32: u8 = BPF_ALU | BPF_NEG;
+/// BPF opcode: `mod32 dst, imm` /// `dst %= imm`.
+pub const MOD32_IMM: u8 = BPF_ALU | BPF_K | BPF_MOD;
+/// BPF opcode: `mod32 dst, src` /// `dst %= src`.
+pub const MOD32_REG: u8 = BPF_ALU | BPF_X | BPF_MOD;
+/// BPF opcode: `xor32 dst, imm` /// `dst ^= imm`.
+pub const XOR32_IMM: u8 = BPF_ALU | BPF_K | BPF_XOR;
+/// BPF opcode: `xor32 dst, src` /// `dst ^= src`.
+pub const XOR32_REG: u8 = BPF_ALU | BPF_X | BPF_XOR;
+/// BPF opcode: `mov32 dst, imm` /// `dst = imm`.
+pub const MOV32_IMM: u8 = BPF_ALU | BPF_K | BPF_MOV;
+/// BPF opcode: `mov32 dst, src` /// `dst = src`.
+pub const MOV32_REG: u8 = BPF_ALU | BPF_X | BPF_MOV;
+/// BPF opcode: `arsh32 dst, imm` /// `dst >>= imm (arithmetic)`.
+///
+/// <https://en.wikipedia.org/wiki/Arithmetic_shift>
+pub const ARSH32_IMM: u8 = BPF_ALU | BPF_K | BPF_ARSH;
+/// BPF opcode: `arsh32 dst, src` /// `dst >>= src (arithmetic)`.
+///
+/// <https://en.wikipedia.org/wiki/Arithmetic_shift>
+pub const ARSH32_REG: u8 = BPF_ALU | BPF_X | BPF_ARSH;
+
+/// BPF opcode: `le dst` /// `dst = htole<imm>(dst), with imm in {16, 32, 64}`.
+pub const LE: u8 = BPF_ALU | BPF_K | BPF_END;
+/// BPF opcode: `be dst` /// `dst = htobe<imm>(dst), with imm in {16, 32, 64}`.
+pub const BE: u8 = BPF_ALU | BPF_X | BPF_END;
+
+/// BPF opcode: `add64 dst, imm` /// `dst += imm`.
+pub const ADD64_IMM: u8 = BPF_ALU64 | BPF_K | BPF_ADD;
+/// BPF opcode: `add64 dst, src` /// `dst += src`.
+pub const ADD64_REG: u8 = BPF_ALU64 | BPF_X | BPF_ADD;
+/// BPF opcode: `sub64 dst, imm` /// `dst -= imm`.
+pub const SUB64_IMM: u8 = BPF_ALU64 | BPF_K | BPF_SUB;
+/// BPF opcode: `sub64 dst, src` /// `dst -= src`.
+pub const SUB64_REG: u8 = BPF_ALU64 | BPF_X | BPF_SUB;
+/// BPF opcode: `div64 dst, imm` /// `dst /= imm`.
+pub const MUL64_IMM: u8 = BPF_ALU64 | BPF_K | BPF_MUL;
+/// BPF opcode: `div64 dst, src` /// `dst /= src`.
+pub const MUL64_REG: u8 = BPF_ALU64 | BPF_X | BPF_MUL;
+/// BPF opcode: `div64 dst, imm` /// `dst /= imm`.
+pub const DIV64_IMM: u8 = BPF_ALU64 | BPF_K | BPF_DIV;
+/// BPF opcode: `div64 dst, src` /// `dst /= src`.
+pub const DIV64_REG: u8 = BPF_ALU64 | BPF_X | BPF_DIV;
+/// BPF opcode: `or64 dst, imm` /// `dst |= imm`.
+pub const OR64_IMM: u8 = BPF_ALU64 | BPF_K | BPF_OR;
+/// BPF opcode: `or64 dst, src` /// `dst |= src`.
+pub const OR64_REG: u8 = BPF_ALU64 | BPF_X | BPF_OR;
+/// BPF opcode: `and64 dst, imm` /// `dst &= imm`.
+pub const AND64_IMM: u8 = BPF_ALU64 | BPF_K | BPF_AND;
+/// BPF opcode: `and64 dst, src` /// `dst &= src`.
+pub const AND64_REG: u8 = BPF_ALU64 | BPF_X | BPF_AND;
+/// BPF opcode: `lsh64 dst, imm` /// `dst <<= imm`.
+pub const LSH64_IMM: u8 = BPF_ALU64 | BPF_K | BPF_LSH;
+/// BPF opcode: `lsh64 dst, src` /// `dst <<= src`.
+pub const LSH64_REG: u8 = BPF_ALU64 | BPF_X | BPF_LSH;
+/// BPF opcode: `rsh64 dst, imm` /// `dst >>= imm`.
+pub const RSH64_IMM: u8 = BPF_ALU64 | BPF_K | BPF_RSH;
+/// BPF opcode: `rsh64 dst, src` /// `dst >>= src`.
+pub const RSH64_REG: u8 = BPF_ALU64 | BPF_X | BPF_RSH;
+/// BPF opcode: `neg64 dst, imm` /// `dst = -dst`.
+pub const NEG64: u8 = BPF_ALU64 | BPF_NEG;
+/// BPF opcode: `mod64 dst, imm` /// `dst %= imm`.
+pub const MOD64_IMM: u8 = BPF_ALU64 | BPF_K | BPF_MOD;
+/// BPF opcode: `mod64 dst, src` /// `dst %= src`.
+pub const MOD64_REG: u8 = BPF_ALU64 | BPF_X | BPF_MOD;
+/// BPF opcode: `xor64 dst, imm` /// `dst ^= imm`.
+pub const XOR64_IMM: u8 = BPF_ALU64 | BPF_K | BPF_XOR;
+/// BPF opcode: `xor64 dst, src` /// `dst ^= src`.
+pub const XOR64_REG: u8 = BPF_ALU64 | BPF_X | BPF_XOR;
+/// BPF opcode: `mov64 dst, imm` /// `dst = imm`.
+pub const MOV64_IMM: u8 = BPF_ALU64 | BPF_K | BPF_MOV;
+/// BPF opcode: `mov64 dst, src` /// `dst = src`.
+pub const MOV64_REG: u8 = BPF_ALU64 | BPF_X | BPF_MOV;
+/// BPF opcode: `arsh64 dst, imm` /// `dst >>= imm (arithmetic)`.
+///
+/// <https://en.wikipedia.org/wiki/Arithmetic_shift>
+pub const ARSH64_IMM: u8 = BPF_ALU64 | BPF_K | BPF_ARSH;
+/// BPF opcode: `arsh64 dst, src` /// `dst >>= src (arithmetic)`.
+///
+/// <https://en.wikipedia.org/wiki/Arithmetic_shift>
+pub const ARSH64_REG: u8 = BPF_ALU64 | BPF_X | BPF_ARSH;
+
+/// BPF opcode: `ja +off` /// `PC += off`.
+pub const JA: u8 = BPF_JMP | BPF_JA;
+/// BPF opcode: `jeq dst, imm, +off` /// `PC += off if dst == imm`.
+pub const JEQ_IMM: u8 = BPF_JMP | BPF_K | BPF_JEQ;
+/// BPF opcode: `jeq dst, src, +off` /// `PC += off if dst == src`.
+pub const JEQ_REG: u8 = BPF_JMP | BPF_X | BPF_JEQ;
+/// BPF opcode: `jgt dst, imm, +off` /// `PC += off if dst > imm`.
+pub const JGT_IMM: u8 = BPF_JMP | BPF_K | BPF_JGT;
+/// BPF opcode: `jgt dst, src, +off` /// `PC += off if dst > src`.
+pub const JGT_REG: u8 = BPF_JMP | BPF_X | BPF_JGT;
+/// BPF opcode: `jge dst, imm, +off` /// `PC += off if dst >= imm`.
+pub const JGE_IMM: u8 = BPF_JMP | BPF_K | BPF_JGE;
+/// BPF opcode: `jge dst, src, +off` /// `PC += off if dst >= src`.
+pub const JGE_REG: u8 = BPF_JMP | BPF_X | BPF_JGE;
+/// BPF opcode: `jlt dst, imm, +off` /// `PC += off if dst < imm`.
+pub const JLT_IMM: u8 = BPF_JMP | BPF_K | BPF_JLT;
+/// BPF opcode: `jlt dst, src, +off` /// `PC += off if dst < src`.
+pub const JLT_REG: u8 = BPF_JMP | BPF_X | BPF_JLT;
+/// BPF opcode: `jle dst, imm, +off` /// `PC += off if dst <= imm`.
+pub const JLE_IMM: u8 = BPF_JMP | BPF_K | BPF_JLE;
+/// BPF opcode: `jle dst, src, +off` /// `PC += off if dst <= src`.
+pub const JLE_REG: u8 = BPF_JMP | BPF_X | BPF_JLE;
+/// BPF opcode: `jset dst, imm, +off` /// `PC += off if dst & imm`.
+pub const JSET_IMM: u8 = BPF_JMP | BPF_K | BPF_JSET;
+/// BPF opcode: `jset dst, src, +off` /// `PC += off if dst & src`.
+pub const JSET_REG: u8 = BPF_JMP | BPF_X | BPF_JSET;
+/// BPF opcode: `jne dst, imm, +off` /// `PC += off if dst != imm`.
+pub const JNE_IMM: u8 = BPF_JMP | BPF_K | BPF_JNE;
+/// BPF opcode: `jne dst, src, +off` /// `PC += off if dst != src`.
+pub const JNE_REG: u8 = BPF_JMP | BPF_X | BPF_JNE;
+/// BPF opcode: `jsgt dst, imm, +off` /// `PC += off if dst > imm (signed)`.
+pub const JSGT_IMM: u8 = BPF_JMP | BPF_K | BPF_JSGT;
+/// BPF opcode: `jsgt dst, src, +off` /// `PC += off if dst > src (signed)`.
+pub const JSGT_REG: u8 = BPF_JMP | BPF_X | BPF_JSGT;
+/// BPF opcode: `jsge dst, imm, +off` /// `PC += off if dst >= imm (signed)`.
+pub const JSGE_IMM: u8 = BPF_JMP | BPF_K | BPF_JSGE;
+/// BPF opcode: `jsge dst, src, +off` /// `PC += off if dst >= src (signed)`.
+pub const JSGE_REG: u8 = BPF_JMP | BPF_X | BPF_JSGE;
+/// BPF opcode: `jslt dst, imm, +off` /// `PC += off if dst < imm (signed)`.
+pub const JSLT_IMM: u8 = BPF_JMP | BPF_K | BPF_JSLT;
+/// BPF opcode: `jslt dst, src, +off` /// `PC += off if dst < src (signed)`.
+pub const JSLT_REG: u8 = BPF_JMP | BPF_X | BPF_JSLT;
+/// BPF opcode: `jsle dst, imm, +off` /// `PC += off if dst <= imm (signed)`.
+pub const JSLE_IMM: u8 = BPF_JMP | BPF_K | BPF_JSLE;
+/// BPF opcode: `jsle dst, src, +off` /// `PC += off if dst <= src (signed)`.
+pub const JSLE_REG: u8 = BPF_JMP | BPF_X | BPF_JSLE;
+
+/// BPF opcode: `jeq dst, imm, +off` /// `PC += off if (dst as u32) == imm`.
+pub const JEQ_IMM32: u8 = BPF_JMP32 | BPF_K | BPF_JEQ;
+/// BPF opcode: `jeq dst, src, +off` /// `PC += off if (dst as u32) == (src as u32)`.
+pub const JEQ_REG32: u8 = BPF_JMP32 | BPF_X | BPF_JEQ;
+/// BPF opcode: `jgt dst, imm, +off` /// `PC += off if (dst as u32) > imm`.
+pub const JGT_IMM32: u8 = BPF_JMP32 | BPF_K | BPF_JGT;
+/// BPF opcode: `jgt dst, src, +off` /// `PC += off if (dst as u32) > (src as u32)`.
+pub const JGT_REG32: u8 = BPF_JMP32 | BPF_X | BPF_JGT;
+/// BPF opcode: `jge dst, imm, +off` /// `PC += off if (dst as u32) >= imm`.
+pub const JGE_IMM32: u8 = BPF_JMP32 | BPF_K | BPF_JGE;
+/// BPF opcode: `jge dst, src, +off` /// `PC += off if (dst as u32) >= (src as u32)`.
+pub const JGE_REG32: u8 = BPF_JMP32 | BPF_X | BPF_JGE;
+/// BPF opcode: `jlt dst, imm, +off` /// `PC += off if (dst as u32) < imm`.
+pub const JLT_IMM32: u8 = BPF_JMP32 | BPF_K | BPF_JLT;
+/// BPF opcode: `jlt dst, src, +off` /// `PC += off if (dst as u32) < (src as u32)`.
+pub const JLT_REG32: u8 = BPF_JMP32 | BPF_X | BPF_JLT;
+/// BPF opcode: `jle dst, imm, +off` /// `PC += off if (dst as u32) <= imm`.
+pub const JLE_IMM32: u8 = BPF_JMP32 | BPF_K | BPF_JLE;
+/// BPF opcode: `jle dst, src, +off` /// `PC += off if (dst as u32) <= (src as u32)`.
+pub const JLE_REG32: u8 = BPF_JMP32 | BPF_X | BPF_JLE;
+/// BPF opcode: `jset dst, imm, +off` /// `PC += off if (dst as u32) & imm`.
+pub const JSET_IMM32: u8 = BPF_JMP32 | BPF_K | BPF_JSET;
+/// BPF opcode: `jset dst, src, +off` /// `PC += off if (dst as u32) & (src as u32)`.
+pub const JSET_REG32: u8 = BPF_JMP32 | BPF_X | BPF_JSET;
+/// BPF opcode: `jne dst, imm, +off` /// `PC += off if (dst as u32) != imm`.
+pub const JNE_IMM32: u8 = BPF_JMP32 | BPF_K | BPF_JNE;
+/// BPF opcode: `jne dst, src, +off` /// `PC += off if (dst as u32) != (src as u32)`.
+pub const JNE_REG32: u8 = BPF_JMP32 | BPF_X | BPF_JNE;
+/// BPF opcode: `jsgt dst, imm, +off` /// `PC += off if (dst as i32) > imm (signed)`.
+pub const JSGT_IMM32: u8 = BPF_JMP32 | BPF_K | BPF_JSGT;
+/// BPF opcode: `jsgt dst, src, +off` /// `PC += off if (dst as i32) > (src as i32) (signed)`.
+pub const JSGT_REG32: u8 = BPF_JMP32 | BPF_X | BPF_JSGT;
+/// BPF opcode: `jsge dst, imm, +off` /// `PC += off if (dst as i32) >= imm (signed)`.
+pub const JSGE_IMM32: u8 = BPF_JMP32 | BPF_K | BPF_JSGE;
+/// BPF opcode: `jsge dst, src, +off` /// `PC += off if (dst as i32) >= (src as i32) (signed)`.
+pub const JSGE_REG32: u8 = BPF_JMP32 | BPF_X | BPF_JSGE;
+/// BPF opcode: `jslt dst, imm, +off` /// `PC += off if (dst as i32) < imm (signed)`.
+pub const JSLT_IMM32: u8 = BPF_JMP32 | BPF_K | BPF_JSLT;
+/// BPF opcode: `jslt dst, src, +off` /// `PC += off if (dst as i32) < (src as i32) (signed)`.
+pub const JSLT_REG32: u8 = BPF_JMP32 | BPF_X | BPF_JSLT;
+/// BPF opcode: `jsle dst, imm, +off` /// `PC += off if (dst as i32) <= imm (signed)`.
+pub const JSLE_IMM32: u8 = BPF_JMP32 | BPF_K | BPF_JSLE;
+/// BPF opcode: `jsle dst, src, +off` /// `PC += off if (dst as i32) <= (src as i32) (signed)`.
+pub const JSLE_REG32: u8 = BPF_JMP32 | BPF_X | BPF_JSLE;
+
+/// BPF opcode: `call imm` /// helper function call to helper with key `imm`.
+pub const CALL: u8 = BPF_JMP | BPF_CALL;
+/// BPF opcode: tail call.
+pub const TAIL_CALL: u8 = BPF_JMP | BPF_X | BPF_CALL;
+/// BPF opcode: `exit` /// `return r0`.
+pub const EXIT: u8 = BPF_JMP | BPF_EXIT;
+
+// Used in JIT
+/// Mask to extract the operation class from an operation code.
+pub const BPF_CLS_MASK: u8 = 0x07;
+/// Mask to extract the arithmetic operation code from an instruction operation code.
+pub const BPF_ALU_OP_MASK: u8 = 0xf0;
+
+/// Prototype of an eBPF helper function.
+pub type Helper = fn(u64, u64, u64, u64, u64) -> u64;
+
+/// An eBPF instruction.
+///
+/// See <https://www.kernel.org/doc/Documentation/networking/filter.txt> for the Linux kernel
+/// documentation about eBPF, or <https://github.com/iovisor/bpf-docs/blob/master/eBPF.md> for a
+/// more concise version.
+#[derive(Debug, PartialEq, Eq, Clone)]
+pub struct Insn {
+    /// Operation code.
+    pub opc: u8,
+    /// Destination register operand.
+    pub dst: u8,
+    /// Source register operand.
+    pub src: u8,
+    /// Offset operand.
+    pub off: i16,
+    /// Immediate value operand.
+    pub imm: i32,
+}
+
+impl Insn {
+    /// Turn an `Insn` back into an array of bytes.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use rbpf::ebpf;
+    ///
+    /// let prog: &[u8] = &[
+    ///     0xb7, 0x12, 0x56, 0x34, 0xde, 0xbc, 0x9a, 0x78,
+    ///     ];
+    /// let insn = ebpf::Insn {
+    ///     opc: 0xb7,
+    ///     dst: 2,
+    ///     src: 1,
+    ///     off: 0x3456,
+    ///     imm: 0x789abcde
+    /// };
+    /// assert_eq!(insn.to_array(), prog);
+    /// ```
+    pub fn to_array(&self) -> [u8; INSN_SIZE] {
+        [
+            self.opc,
+            self.src.wrapping_shl(4) | self.dst,
+            (self.off & 0xff) as u8,
+            self.off.wrapping_shr(8) as u8,
+            (self.imm & 0xff) as u8,
+            (self.imm & 0xff_00).wrapping_shr(8) as u8,
+            (self.imm as u32 & 0xff_00_00).wrapping_shr(16) as u8,
+            (self.imm as u32 & 0xff_00_00_00).wrapping_shr(24) as u8,
+        ]
+    }
+
+    /// Turn an `Insn` into an vector of bytes.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use rbpf::ebpf;
+    ///
+    /// let prog: Vec<u8> = vec![
+    ///     0xb7, 0x12, 0x56, 0x34, 0xde, 0xbc, 0x9a, 0x78,
+    ///     ];
+    /// let insn = ebpf::Insn {
+    ///     opc: 0xb7,
+    ///     dst: 2,
+    ///     src: 1,
+    ///     off: 0x3456,
+    ///     imm: 0x789abcde
+    /// };
+    /// assert_eq!(insn.to_vec(), prog);
+    /// ```
+    pub fn to_vec(&self) -> Vec<u8> {
+        vec![
+            self.opc,
+            self.src.wrapping_shl(4) | self.dst,
+            (self.off & 0xff) as u8,
+            self.off.wrapping_shr(8) as u8,
+            (self.imm & 0xff) as u8,
+            (self.imm & 0xff_00).wrapping_shr(8) as u8,
+            (self.imm as u32 & 0xff_00_00).wrapping_shr(16) as u8,
+            (self.imm as u32 & 0xff_00_00_00).wrapping_shr(24) as u8,
+        ]
+    }
+}
+
+/// Get the instruction at `idx` of an eBPF program. `idx` is the index (number) of the
+/// instruction (not a byte offset). The first instruction has index 0.
+///
+/// # Panics
+///
+/// Panics if it is not possible to get the instruction (if idx is too high, or last instruction is
+/// incomplete).
+///
+/// # Examples
+///
+/// ```
+/// use rbpf::ebpf;
+///
+/// let prog = &[
+///     0xb7, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+///     0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+///     ];
+/// let insn = ebpf::get_insn(prog, 1);
+/// assert_eq!(insn.opc, 0x95);
+/// ```
+///
+/// The example below will panic, since the last instruction is not complete and cannot be loaded.
+///
+/// ```rust,should_panic
+/// use rbpf::ebpf;
+///
+/// let prog = &[
+///     0xb7, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+///     0x95, 0x00, 0x00, 0x00, 0x00, 0x00              // two bytes missing
+///     ];
+/// let insn = ebpf::get_insn(prog, 1);
+/// ```
+pub fn get_insn(prog: &[u8], idx: usize) -> Insn {
+    // This guard should not be needed in most cases, since the verifier already checks the program
+    // size, and indexes should be fine in the interpreter/JIT. But this function is publicly
+    // available and user can call it with any `idx`, so we have to check anyway.
+    if (idx + 1) * INSN_SIZE > prog.len() {
+        panic!(
+            "Error: cannot reach instruction at index {:?} in program containing {:?} bytes",
+            idx,
+            prog.len()
+        );
+    }
+    Insn {
+        opc: prog[INSN_SIZE * idx],
+        dst: prog[INSN_SIZE * idx + 1] & 0x0f,
+        src: (prog[INSN_SIZE * idx + 1] & 0xf0) >> 4,
+        off: LittleEndian::read_i16(&prog[(INSN_SIZE * idx + 2)..]),
+        imm: LittleEndian::read_i32(&prog[(INSN_SIZE * idx + 4)..]),
+    }
+}
+
+/// Return a vector of `struct Insn` built from a program.
+///
+/// This is provided as a convenience for users wishing to manipulate a vector of instructions, for
+/// example for dumping the program instruction after instruction with a custom format.
+///
+/// Note that the two parts of `LD_DW_IMM` instructions (spanning on 64 bits) are considered as two
+/// distinct instructions.
+///
+/// # Examples
+///
+/// ```
+/// use rbpf::ebpf;
+///
+/// let prog = &[
+///     0x18, 0x00, 0x00, 0x00, 0x88, 0x77, 0x66, 0x55,
+///     0x00, 0x00, 0x00, 0x00, 0x44, 0x33, 0x22, 0x11,
+///     0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+/// ];
+///
+/// let v = ebpf::to_insn_vec(prog);
+/// assert_eq!(v, vec![
+///     ebpf::Insn {
+///         opc: 0x18,
+///         dst: 0,
+///         src: 0,
+///         off: 0,
+///         imm: 0x55667788
+///     },
+///     ebpf::Insn {
+///         opc: 0,
+///         dst: 0,
+///         src: 0,
+///         off: 0,
+///         imm: 0x11223344
+///     },
+///     ebpf::Insn {
+///         opc: 0x95,
+///         dst: 0,
+///         src: 0,
+///         off: 0,
+///         imm: 0
+///     },
+/// ]);
+/// ```
+pub fn to_insn_vec(prog: &[u8]) -> Vec<Insn> {
+    if prog.len() % INSN_SIZE != 0 {
+        panic!(
+            "Error: eBPF program length must be a multiple of {:?} octets",
+            INSN_SIZE
+        );
+    }
+
+    let mut res = vec![];
+    let mut insn_ptr: usize = 0;
+
+    while insn_ptr * INSN_SIZE < prog.len() {
+        let insn = get_insn(prog, insn_ptr);
+        res.push(insn);
+        insn_ptr += 1;
+    }
+    res
+}

kernel/crates/rbpf/src/helpers.rs

@@ -0,0 +1,488 @@
+// SPDX-License-Identifier: (Apache-2.0 OR MIT)
+// Copyright 2015 Big Switch Networks, Inc
+//      (Algorithms for uBPF helpers, originally in C)
+// Copyright 2016 6WIND S.A. <quentin.monnet@6wind.com>
+//      (Translation to Rust, other helpers)
+
+//! This module implements some built-in helpers that can be called from within an eBPF program.
+//!
+//! These helpers may originate from several places:
+//!
+//! * Some of them mimic the helpers available in the Linux kernel.
+//! * Some of them were proposed as example helpers in uBPF and they were adapted here.
+//! * Other helpers may be specific to rbpf.
+//!
+//! The prototype for helpers is always the same: five `u64` as arguments, and a `u64` as a return
+//! value. Hence some helpers have unused arguments, or return a 0 value in all cases, in order to
+//! respect this convention.
+
+// Helpers associated to kernel helpers
+// See also linux/include/uapi/linux/bpf.h in Linux kernel sources.
+
+// bpf_ktime_getns()
+
+/// Index of helper `bpf_ktime_getns()`, equivalent to `bpf_time_getns()`, in Linux kernel, see
+/// <https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/include/uapi/linux/bpf.h>.
+pub const BPF_KTIME_GETNS_IDX: u32 = 5;
+
+/// Get monotonic time (since boot time) in nanoseconds. All arguments are unused.
+///
+/// # Examples
+///
+/// ```
+/// use rbpf::helpers;
+///
+/// let t = helpers::bpf_time_getns(0, 0, 0, 0, 0);
+/// let d =  t / 10u64.pow(9)  / 60   / 60  / 24;
+/// let h = (t / 10u64.pow(9)  / 60   / 60) % 24;
+/// let m = (t / 10u64.pow(9)  / 60 ) % 60;
+/// let s = (t / 10u64.pow(9)) % 60;
+/// let ns = t % 10u64.pow(9);
+/// println!("Uptime: {:#x} == {} days {}:{}:{}, {} ns", t, d, h, m, s, ns);
+/// ```
+#[allow(dead_code)]
+#[allow(unused_variables)]
+#[allow(deprecated)]
+#[cfg(feature = "std")]
+pub fn bpf_time_getns(unused1: u64, unused2: u64, unused3: u64, unused4: u64, unused5: u64) -> u64 {
+    time::precise_time_ns()
+}
+
+// bpf_trace_printk()
+
+/// Index of helper `bpf_trace_printk()`, equivalent to `bpf_trace_printf()`, in Linux kernel, see
+/// <https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/include/uapi/linux/bpf.h>.
+pub const BPF_TRACE_PRINTK_IDX: u32 = 6;
+
+/// Prints its **last three** arguments to standard output. The **first two** arguments are
+/// **unused**. Returns the number of bytes written.
+///
+/// By ignoring the first two arguments, it creates a helper that will have a behavior similar to
+/// the one of the equivalent helper `bpf_trace_printk()` from Linux kernel.
+///
+/// # Examples
+///
+/// ```
+/// use rbpf::helpers;
+///
+/// let res = helpers::bpf_trace_printf(0, 0, 1, 15, 32);
+/// assert_eq!(res as usize, "bpf_trace_printf: 0x1, 0xf, 0x20\n".len());
+/// ```
+///
+/// This will print `bpf_trace_printf: 0x1, 0xf, 0x20`.
+///
+/// The eBPF code needed to perform the call in this example would be nearly identical to the code
+/// obtained by compiling the following code from C to eBPF with clang:
+///
+/// ```c
+/// #include <linux/bpf.h>
+/// #include "path/to/linux/samples/bpf/bpf_helpers.h"
+///
+/// int main(struct __sk_buff *skb)
+/// {
+///     // Only %d %u %x %ld %lu %lx %lld %llu %llx %p %s conversion specifiers allowed.
+///     // See <https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/kernel/trace/bpf_trace.c>.
+///     char *fmt = "bpf_trace_printk %llx, %llx, %llx\n";
+///     return bpf_trace_printk(fmt, sizeof(fmt), 1, 15, 32);
+/// }
+/// ```
+///
+/// This would equally print the three numbers in `/sys/kernel/debug/tracing` file each time the
+/// program is run.
+#[allow(dead_code)]
+#[allow(unused_variables)]
+#[cfg(feature = "std")]
+pub fn bpf_trace_printf(unused1: u64, unused2: u64, arg3: u64, arg4: u64, arg5: u64) -> u64 {
+    println!("bpf_trace_printf: {arg3:#x}, {arg4:#x}, {arg5:#x}");
+    let size_arg = |x| {
+        if x == 0 {
+            1
+        } else {
+            (x as f64).log(16.0).floor() as u64 + 1
+        }
+    };
+    "bpf_trace_printf: 0x, 0x, 0x\n".len() as u64 + size_arg(arg3) + size_arg(arg4) + size_arg(arg5)
+}
+
+// Helpers coming from uBPF <https://github.com/iovisor/ubpf/blob/master/vm/test.c>
+
+/// The idea is to assemble five bytes into a single `u64`. For compatibility with the helpers API,
+/// each argument must be a `u64`.
+///
+/// # Examples
+///
+/// ```
+/// use rbpf::helpers;
+///
+/// let gathered = helpers::gather_bytes(0x11, 0x22, 0x33, 0x44, 0x55);
+/// assert_eq!(gathered, 0x1122334455);
+/// ```
+pub fn gather_bytes(arg1: u64, arg2: u64, arg3: u64, arg4: u64, arg5: u64) -> u64 {
+    arg1.wrapping_shl(32)
+        | arg2.wrapping_shl(24)
+        | arg3.wrapping_shl(16)
+        | arg4.wrapping_shl(8)
+        | arg5
+}
+
+/// Same as `void *memfrob(void *s, size_t n);` in `string.h` in C. See the GNU manual page (in
+/// section 3) for `memfrob`. The memory is directly modified, and the helper returns 0 in all
+/// cases. Arguments 3 to 5 are unused.
+///
+/// # Examples
+///
+/// ```
+/// use rbpf::helpers;
+///
+/// let val: u64 = 0x112233;
+/// let val_ptr = &val as *const u64;
+///
+/// helpers::memfrob(val_ptr as u64, 8, 0, 0, 0);
+/// assert_eq!(val, 0x2a2a2a2a2a3b0819);
+/// helpers::memfrob(val_ptr as u64, 8, 0, 0, 0);
+/// assert_eq!(val, 0x112233);
+/// ```
+#[allow(unused_variables)]
+pub fn memfrob(ptr: u64, len: u64, unused3: u64, unused4: u64, unused5: u64) -> u64 {
+    for i in 0..len {
+        unsafe {
+            let mut p = (ptr + i) as *mut u8;
+            *p ^= 0b101010;
+        }
+    }
+    0
+}
+
+// TODO: Try again when asm!() is available in stable Rust.
+// #![feature(asm)]
+// #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+// #[allow(unused_variables)]
+// pub fn memfrob (ptr: u64, len: u64, arg3: u64, arg4: u64, arg5: u64) -> u64 {
+//     unsafe {
+//         asm!(
+//                 "mov $0xf0, %rax"
+//             ::: "mov $0xf1, %rcx"
+//             ::: "mov $0xf2, %rdx"
+//             ::: "mov $0xf3, %rsi"
+//             ::: "mov $0xf4, %rdi"
+//             ::: "mov $0xf5, %r8"
+//             ::: "mov $0xf6, %r9"
+//             ::: "mov $0xf7, %r10"
+//             ::: "mov $0xf8, %r11"
+//         );
+//     }
+//     0
+// }
+
+/// Compute and return the square root of argument 1, cast as a float. Arguments 2 to 5 are
+/// unused.
+///
+/// # Examples
+///
+/// ```
+/// use rbpf::helpers;
+///
+/// let x = helpers::sqrti(9, 0, 0, 0, 0);
+/// assert_eq!(x, 3);
+/// ```
+#[allow(dead_code)]
+#[allow(unused_variables)]
+#[cfg(feature = "std")] // sqrt is only available when using `std`
+pub fn sqrti(arg1: u64, unused2: u64, unused3: u64, unused4: u64, unused5: u64) -> u64 {
+    (arg1 as f64).sqrt() as u64
+}
+
+/// C-like `strcmp`, return 0 if the strings are equal, and a non-null value otherwise.
+///
+/// # Examples
+///
+/// ```
+/// use rbpf::helpers;
+///
+/// let foo = "This is a string.\0".as_ptr() as u64;
+/// let bar = "This is another sting.\0".as_ptr() as u64;
+///
+/// assert!(helpers::strcmp(foo, foo, 0, 0, 0) == 0);
+/// assert!(helpers::strcmp(foo, bar, 0, 0, 0) != 0);
+/// ```
+#[allow(dead_code)]
+#[allow(unused_variables)]
+pub fn strcmp(arg1: u64, arg2: u64, arg3: u64, unused4: u64, unused5: u64) -> u64 {
+    // C-like strcmp, maybe shorter than converting the bytes to string and comparing?
+    if arg1 == 0 || arg2 == 0 {
+        return u64::MAX;
+    }
+    let mut a = arg1;
+    let mut b = arg2;
+    unsafe {
+        let mut a_val = *(a as *const u8);
+        let mut b_val = *(b as *const u8);
+        while a_val == b_val && a_val != 0 && b_val != 0 {
+            a += 1;
+            b += 1;
+            a_val = *(a as *const u8);
+            b_val = *(b as *const u8);
+        }
+        if a_val >= b_val {
+            (a_val - b_val) as u64
+        } else {
+            (b_val - a_val) as u64
+        }
+    }
+}
+
+// Some additional helpers
+
+/// Returns a random u64 value comprised between `min` and `max` values (inclusive). Arguments 3 to
+/// 5 are unused.
+///
+/// Relies on `rand()` function from libc, so `libc::srand()` should be called once before this
+/// helper is used.
+///
+/// # Examples
+///
+/// ```
+/// extern crate libc;
+/// extern crate rbpf;
+/// extern crate time;
+///
+/// unsafe {
+///     libc::srand(time::precise_time_ns() as u32)
+/// }
+///
+/// let n = rbpf::helpers::rand(3, 6, 0, 0, 0);
+/// assert!(3 <= n && n <= 6);
+/// ```
+#[allow(dead_code)]
+#[allow(unused_variables)]
+#[cfg(feature = "std")]
+pub fn rand(min: u64, max: u64, unused3: u64, unused4: u64, unused5: u64) -> u64 {
+    let mut n = unsafe { (libc::rand() as u64).wrapping_shl(32) + libc::rand() as u64 };
+    if min < max {
+        n = n % (max + 1 - min) + min;
+    };
+    n
+}
+/// Prints the helper functions name and it's index.
+#[cfg(feature = "std")]
+pub fn show_helper() {
+    for (index, name) in BPF_FUNC_MAPPER.iter().enumerate() {
+        println!("{}:{}", index, name);
+    }
+}
+
+/// See https://github.com/torvalds/linux/blob/master/include/uapi/linux/bpf.h
+pub const BPF_FUNC_MAPPER: &[&str] = &[
+    "unspec",
+    "map_lookup_elem",
+    "map_update_elem",
+    "map_delete_elem",
+    "probe_read",
+    "ktime_get_ns",
+    "trace_printk",
+    "get_prandom_u32",
+    "get_smp_processor_id",
+    "skb_store_bytes",
+    "l3_csum_replace",
+    "l4_csum_replace",
+    "tail_call",
+    "clone_redirect",
+    "get_current_pid_tgid",
+    "get_current_uid_gid",
+    "get_current_comm",
+    "get_cgroup_classid",
+    "skb_vlan_push",
+    "skb_vlan_pop",
+    "skb_get_tunnel_key",
+    "skb_set_tunnel_key",
+    "perf_event_read",
+    "redirect",
+    "get_route_realm",
+    "perf_event_output",
+    "skb_load_bytes",
+    "get_stackid",
+    "csum_diff",
+    "skb_get_tunnel_opt",
+    "skb_set_tunnel_opt",
+    "skb_change_proto",
+    "skb_change_type",
+    "skb_under_cgroup",
+    "get_hash_recalc",
+    "get_current_task",
+    "probe_write_user",
+    "current_task_under_cgroup",
+    "skb_change_tail",
+    "skb_pull_data",
+    "csum_update",
+    "set_hash_invalid",
+    "get_numa_node_id",
+    "skb_change_head",
+    "xdp_adjust_head",
+    "probe_read_str",
+    "get_socket_cookie",
+    "get_socket_uid",
+    "set_hash",
+    "setsockopt",
+    "skb_adjust_room",
+    "redirect_map",
+    "sk_redirect_map",
+    "sock_map_update",
+    "xdp_adjust_meta",
+    "perf_event_read_value",
+    "perf_prog_read_value",
+    "getsockopt",
+    "override_return",
+    "sock_ops_cb_flags_set",
+    "msg_redirect_map",
+    "msg_apply_bytes",
+    "msg_cork_bytes",
+    "msg_pull_data",
+    "bind",
+    "xdp_adjust_tail",
+    "skb_get_xfrm_state",
+    "get_stack",
+    "skb_load_bytes_relative",
+    "fib_lookup",
+    "sock_hash_update",
+    "msg_redirect_hash",
+    "sk_redirect_hash",
+    "lwt_push_encap",
+    "lwt_seg6_store_bytes",
+    "lwt_seg6_adjust_srh",
+    "lwt_seg6_action",
+    "rc_repeat",
+    "rc_keydown",
+    "skb_cgroup_id",
+    "get_current_cgroup_id",
+    "get_local_storage",
+    "sk_select_reuseport",
+    "skb_ancestor_cgroup_id",
+    "sk_lookup_tcp",
+    "sk_lookup_udp",
+    "sk_release",
+    "map_push_elem",
+    "map_pop_elem",
+    "map_peek_elem",
+    "msg_push_data",
+    "msg_pop_data",
+    "rc_pointer_rel",
+    "spin_lock",
+    "spin_unlock",
+    "sk_fullsock",
+    "tcp_sock",
+    "skb_ecn_set_ce",
+    "get_listener_sock",
+    "skc_lookup_tcp",
+    "tcp_check_syncookie",
+    "sysctl_get_name",
+    "sysctl_get_current_value",
+    "sysctl_get_new_value",
+    "sysctl_set_new_value",
+    "strtol",
+    "strtoul",
+    "sk_storage_get",
+    "sk_storage_delete",
+    "send_signal",
+    "tcp_gen_syncookie",
+    "skb_output",
+    "probe_read_user",
+    "probe_read_kernel",
+    "probe_read_user_str",
+    "probe_read_kernel_str",
+    "tcp_send_ack",
+    "send_signal_thread",
+    "jiffies64",
+    "read_branch_records",
+    "get_ns_current_pid_tgid",
+    "xdp_output",
+    "get_netns_cookie",
+    "get_current_ancestor_cgroup_id",
+    "sk_assign",
+    "ktime_get_boot_ns",
+    "seq_printf",
+    "seq_write",
+    "sk_cgroup_id",
+    "sk_ancestor_cgroup_id",
+    "ringbuf_output",
+    "ringbuf_reserve",
+    "ringbuf_submit",
+    "ringbuf_discard",
+    "ringbuf_query",
+    "csum_level",
+    "skc_to_tcp6_sock",
+    "skc_to_tcp_sock",
+    "skc_to_tcp_timewait_sock",
+    "skc_to_tcp_request_sock",
+    "skc_to_udp6_sock",
+    "get_task_stack",
+    "load_hdr_opt",
+    "store_hdr_opt",
+    "reserve_hdr_opt",
+    "inode_storage_get",
+    "inode_storage_delete",
+    "d_path",
+    "copy_from_user",
+    "snprintf_btf",
+    "seq_printf_btf",
+    "skb_cgroup_classid",
+    "redirect_neigh",
+    "per_cpu_ptr",
+    "this_cpu_ptr",
+    "redirect_peer",
+    "task_storage_get",
+    "task_storage_delete",
+    "get_current_task_btf",
+    "bprm_opts_set",
+    "ktime_get_coarse_ns",
+    "ima_inode_hash",
+    "sock_from_file",
+    "check_mtu",
+    "for_each_map_elem",
+    "snprintf",
+    "sys_bpf",
+    "btf_find_by_name_kind",
+    "sys_close",
+    "timer_init",
+    "timer_set_callback",
+    "timer_start",
+    "timer_cancel",
+    "get_func_ip",
+    "get_attach_cookie",
+    "task_pt_regs",
+    "get_branch_snapshot",
+    "trace_vprintk",
+    "skc_to_unix_sock",
+    "kallsyms_lookup_name",
+    "find_vma",
+    "loop",
+    "strncmp",
+    "get_func_arg",
+    "get_func_ret",
+    "get_func_arg_cnt",
+    "get_retval",
+    "set_retval",
+    "xdp_get_buff_len",
+    "xdp_load_bytes",
+    "xdp_store_bytes",
+    "copy_from_user_task",
+    "skb_set_tstamp",
+    "ima_file_hash",
+    "kptr_xchg",
+    "map_lookup_percpu_elem",
+    "skc_to_mptcp_sock",
+    "dynptr_from_mem",
+    "ringbuf_reserve_dynptr",
+    "ringbuf_submit_dynptr",
+    "ringbuf_discard_dynptr",
+    "dynptr_read",
+    "dynptr_write",
+    "dynptr_data",
+    "tcp_raw_gen_syncookie_ipv4",
+    "tcp_raw_gen_syncookie_ipv6",
+    "tcp_raw_check_syncookie_ipv4",
+    "tcp_raw_check_syncookie_ipv6",
+    "ktime_get_tai_ns",
+    "user_ringbuf_drain",
+    "cgrp_storage_get",
+    "cgrp_storage_delete",
+];

kernel/crates/rbpf/src/interpreter.rs

@@ -0,0 +1,708 @@
+// SPDX-License-Identifier: (Apache-2.0 OR MIT)
+// Derived from uBPF <https://github.com/iovisor/ubpf>
+// Copyright 2015 Big Switch Networks, Inc
+//      (uBPF: VM architecture, parts of the interpreter, originally in C)
+// Copyright 2016 6WIND S.A. <quentin.monnet@6wind.com>
+//      (Translation to Rust, MetaBuff/multiple classes addition, hashmaps for helpers)
+
+use crate::{
+    ebpf::{self, Insn},
+    helpers::BPF_FUNC_MAPPER,
+    stack::StackFrame,
+    *,
+};
+
+#[cfg(not(feature = "user"))]
+#[allow(unused)]
+fn check_mem(
+    addr: u64,
+    len: usize,
+    access_type: &str,
+    insn_ptr: usize,
+    mbuff: &[u8],
+    mem: &[u8],
+    stack: &[u8],
+) -> Result<(), Error> {
+    log::trace!(
+        "check_mem: addr {:#x}, len {}, access_type {}, insn_ptr {}",
+        addr,
+        len,
+        access_type,
+        insn_ptr
+    );
+    log::trace!(
+        "check_mem: mbuff: {:#x}/{:#x}, mem: {:#x}/{:#x}, stack: {:#x}/{:#x}",
+        mbuff.as_ptr() as u64,
+        mbuff.len(),
+        mem.as_ptr() as u64,
+        mem.len(),
+        stack.as_ptr() as u64,
+        stack.len()
+    );
+    Ok(())
+}
+
+#[cfg(feature = "user")]
+fn check_mem(
+    addr: u64,
+    len: usize,
+    access_type: &str,
+    insn_ptr: usize,
+    mbuff: &[u8],
+    mem: &[u8],
+    stack: &[u8],
+) -> Result<(), Error> {
+    if let Some(addr_end) = addr.checked_add(len as u64) {
+        if mbuff.as_ptr() as u64 <= addr && addr_end <= mbuff.as_ptr() as u64 + mbuff.len() as u64 {
+            return Ok(());
+        }
+        if mem.as_ptr() as u64 <= addr && addr_end <= mem.as_ptr() as u64 + mem.len() as u64 {
+            return Ok(());
+        }
+        if stack.as_ptr() as u64 <= addr && addr_end <= stack.as_ptr() as u64 + stack.len() as u64 {
+            return Ok(());
+        }
+    }
+
+    Err(Error::new(ErrorKind::Other, format!(
+        "Error: out of bounds memory {} (insn #{:?}), addr {:#x}, size {:?}\nmbuff: {:#x}/{:#x}, mem: {:#x}/{:#x}, stack: {:#x}/{:#x}",
+        access_type, insn_ptr, addr, len,
+        mbuff.as_ptr() as u64, mbuff.len(),
+        mem.as_ptr() as u64, mem.len(),
+        stack.as_ptr() as u64, stack.len()
+    )))
+}
+
+#[inline]
+fn do_jump(insn_ptr: &mut usize, insn: &Insn) {
+    *insn_ptr = (*insn_ptr as i16 + insn.off) as usize;
+}
+
+#[allow(unknown_lints)]
+#[allow(cyclomatic_complexity)]
+pub fn execute_program(
+    prog_: Option<&[u8]>,
+    mem: &[u8],
+    mbuff: &[u8],
+    helpers: &HashMap<u32, ebpf::Helper>,
+) -> Result<u64, Error> {
+    const U32MAX: u64 = u32::MAX as u64;
+    const SHIFT_MASK_64: u64 = 0x3f;
+
+    let prog = match prog_ {
+        Some(prog) => prog,
+        None => Err(Error::new(
+            ErrorKind::Other,
+            "Error: No program set, call prog_set() to load one",
+        ))?,
+    };
+    let mut stacks = Vec::new();
+    let stack = StackFrame::new();
+    // R1 points to beginning of memory area, R10 to stack
+    let mut reg: [u64; 11] = [
+        0,
+        0,
+        0,
+        0,
+        0,
+        0,
+        0,
+        0,
+        0,
+        0,
+        stack.as_ptr() as u64 + stack.len() as u64,
+    ];
+    stacks.push(stack);
+    if !mbuff.is_empty() {
+        reg[1] = mbuff.as_ptr() as u64;
+    } else if !mem.is_empty() {
+        reg[1] = mem.as_ptr() as u64;
+    }
+    let check_mem_load =
+        |stack: &[u8], addr: u64, len: usize, insn_ptr: usize| -> Result<(), Error> {
+            check_mem(addr, len, "load", insn_ptr, mbuff, mem, stack)
+        };
+    let check_mem_store =
+        |stack: &[u8], addr: u64, len: usize, insn_ptr: usize| -> Result<(), Error> {
+            check_mem(addr, len, "store", insn_ptr, mbuff, mem, stack)
+        };
+
+    // Loop on instructions
+    let mut insn_ptr: usize = 0;
+    while insn_ptr * ebpf::INSN_SIZE < prog.len() {
+        let insn = ebpf::get_insn(prog, insn_ptr);
+        insn_ptr += 1;
+        let _dst = insn.dst as usize;
+        let _src = insn.src as usize;
+
+        match insn.opc {
+            // BPF_LD class
+            // LD_ABS_* and LD_IND_* are supposed to load pointer to data from metadata buffer.
+            // Since this pointer is constant, and since we already know it (mem), do not
+            // bother re-fetching it, just use mem already.
+            ebpf::LD_ABS_B => {
+                reg[0] = unsafe {
+                    let x = (mem.as_ptr() as u64 + (insn.imm as u32) as u64) as *const u8;
+                    check_mem_load(stacks.last().unwrap().as_slice(), x as u64, 8, insn_ptr)?;
+                    x.read_unaligned() as u64
+                }
+            }
+            ebpf::LD_ABS_H => {
+                reg[0] = unsafe {
+                    let x = (mem.as_ptr() as u64 + (insn.imm as u32) as u64) as *const u16;
+                    check_mem_load(stacks.last().unwrap().as_slice(), x as u64, 8, insn_ptr)?;
+                    x.read_unaligned() as u64
+                }
+            }
+            ebpf::LD_ABS_W => {
+                reg[0] = unsafe {
+                    let x = (mem.as_ptr() as u64 + (insn.imm as u32) as u64) as *const u32;
+                    check_mem_load(stacks.last().unwrap().as_slice(), x as u64, 8, insn_ptr)?;
+                    x.read_unaligned() as u64
+                }
+            }
+            ebpf::LD_ABS_DW => {
+                log::info!("executing LD_ABS_DW, set reg[{}] to {:#x}", _dst, insn.imm);
+                reg[0] = unsafe {
+                    let x = (mem.as_ptr() as u64 + (insn.imm as u32) as u64) as *const u64;
+                    check_mem_load(stacks.last().unwrap().as_slice(), x as u64, 8, insn_ptr)?;
+                    x.read_unaligned()
+                }
+            }
+            ebpf::LD_IND_B => {
+                reg[0] = unsafe {
+                    let x =
+                        (mem.as_ptr() as u64 + reg[_src] + (insn.imm as u32) as u64) as *const u8;
+                    check_mem_load(stacks.last().unwrap().as_slice(), x as u64, 8, insn_ptr)?;
+                    x.read_unaligned() as u64
+                }
+            }
+            ebpf::LD_IND_H => {
+                reg[0] = unsafe {
+                    let x =
+                        (mem.as_ptr() as u64 + reg[_src] + (insn.imm as u32) as u64) as *const u16;
+                    check_mem_load(stacks.last().unwrap().as_slice(), x as u64, 8, insn_ptr)?;
+                    x.read_unaligned() as u64
+                }
+            }
+            ebpf::LD_IND_W => {
+                reg[0] = unsafe {
+                    let x =
+                        (mem.as_ptr() as u64 + reg[_src] + (insn.imm as u32) as u64) as *const u32;
+                    check_mem_load(stacks.last().unwrap().as_slice(), x as u64, 8, insn_ptr)?;
+                    x.read_unaligned() as u64
+                }
+            }
+            ebpf::LD_IND_DW => {
+                reg[0] = unsafe {
+                    let x =
+                        (mem.as_ptr() as u64 + reg[_src] + (insn.imm as u32) as u64) as *const u64;
+                    check_mem_load(stacks.last().unwrap().as_slice(), x as u64, 8, insn_ptr)?;
+                    x.read_unaligned()
+                }
+            }
+
+            ebpf::LD_DW_IMM => {
+                let next_insn = ebpf::get_insn(prog, insn_ptr);
+                insn_ptr += 1;
+                // log::warn!(
+                //     "executing LD_DW_IMM, set reg[{}] to {:#x}",
+                //     _dst,
+                //     ((insn.imm as u32) as u64) + ((next_insn.imm as u64) << 32)
+                // );
+                reg[_dst] = ((insn.imm as u32) as u64) + ((next_insn.imm as u64) << 32);
+            }
+
+            // BPF_LDX class
+            ebpf::LD_B_REG => {
+                reg[_dst] = unsafe {
+                    #[allow(clippy::cast_ptr_alignment)]
+                    let x = (reg[_src] as *const u8).offset(insn.off as isize);
+                    check_mem_load(stacks.last().unwrap().as_slice(), x as u64, 1, insn_ptr)?;
+                    x.read_unaligned() as u64
+                }
+            }
+            ebpf::LD_H_REG => {
+                reg[_dst] = unsafe {
+                    #[allow(clippy::cast_ptr_alignment)]
+                    let x = (reg[_src] as *const u8).offset(insn.off as isize) as *const u16;
+                    check_mem_load(stacks.last().unwrap().as_slice(), x as u64, 2, insn_ptr)?;
+                    x.read_unaligned() as u64
+                }
+            }
+            ebpf::LD_W_REG => {
+                reg[_dst] = unsafe {
+                    #[allow(clippy::cast_ptr_alignment)]
+                    let x = (reg[_src] as *const u8).offset(insn.off as isize) as *const u32;
+                    check_mem_load(stacks.last().unwrap().as_slice(), x as u64, 4, insn_ptr)?;
+                    // log::warn!(
+                    //     "executing LD_W_REG, the ptr is REG:{} -> [{:#x}] + {:#x}",
+                    //     _src,
+                    //     reg[_src],
+                    //     insn.off
+                    // );
+                    x.read_unaligned() as u64
+                }
+            }
+            ebpf::LD_DW_REG => {
+                reg[_dst] = unsafe {
+                    #[allow(clippy::cast_ptr_alignment)]
+                    let x = (reg[_src] as *const u8).offset(insn.off as isize) as *const u64;
+                    check_mem_load(stacks.last().unwrap().as_slice(), x as u64, 8, insn_ptr)?;
+                    x.read_unaligned()
+                }
+            }
+
+            // BPF_ST class
+            ebpf::ST_B_IMM => unsafe {
+                let x = (reg[_dst] as *const u8).offset(insn.off as isize) as *mut u8;
+                check_mem_store(stacks.last().unwrap().as_slice(), x as u64, 1, insn_ptr)?;
+                x.write_unaligned(insn.imm as u8);
+            },
+            ebpf::ST_H_IMM => unsafe {
+                #[allow(clippy::cast_ptr_alignment)]
+                let x = (reg[_dst] as *const u8).offset(insn.off as isize) as *mut u16;
+                check_mem_store(stacks.last().unwrap().as_slice(), x as u64, 2, insn_ptr)?;
+                x.write_unaligned(insn.imm as u16);
+            },
+            ebpf::ST_W_IMM => unsafe {
+                #[allow(clippy::cast_ptr_alignment)]
+                let x = (reg[_dst] as *const u8).offset(insn.off as isize) as *mut u32;
+                check_mem_store(stacks.last().unwrap().as_slice(), x as u64, 4, insn_ptr)?;
+                x.write_unaligned(insn.imm as u32);
+            },
+            ebpf::ST_DW_IMM => unsafe {
+                #[allow(clippy::cast_ptr_alignment)]
+                let x = (reg[_dst] as *const u8).offset(insn.off as isize) as *mut u64;
+                check_mem_store(stacks.last().unwrap().as_slice(), x as u64, 8, insn_ptr)?;
+                x.write_unaligned(insn.imm as u64);
+            },
+
+            // BPF_STX class
+            ebpf::ST_B_REG => unsafe {
+                let x = (reg[_dst] as *const u8).offset(insn.off as isize) as *mut u8;
+                check_mem_store(stacks.last().unwrap().as_slice(), x as u64, 1, insn_ptr)?;
+                x.write_unaligned(reg[_src] as u8);
+            },
+            ebpf::ST_H_REG => unsafe {
+                #[allow(clippy::cast_ptr_alignment)]
+                let x = (reg[_dst] as *const u8).offset(insn.off as isize) as *mut u16;
+                check_mem_store(stacks.last().unwrap().as_slice(), x as u64, 2, insn_ptr)?;
+                x.write_unaligned(reg[_src] as u16);
+            },
+            ebpf::ST_W_REG => unsafe {
+                #[allow(clippy::cast_ptr_alignment)]
+                let x = (reg[_dst] as *const u8).offset(insn.off as isize) as *mut u32;
+                check_mem_store(stacks.last().unwrap().as_slice(), x as u64, 4, insn_ptr)?;
+                x.write_unaligned(reg[_src] as u32);
+            },
+            ebpf::ST_DW_REG => unsafe {
+                #[allow(clippy::cast_ptr_alignment)]
+                let x = (reg[_dst] as *const u8).offset(insn.off as isize) as *mut u64;
+                check_mem_store(stacks.last().unwrap().as_slice(), x as u64, 8, insn_ptr)?;
+                x.write_unaligned(reg[_src]);
+            },
+            ebpf::ST_W_XADD => unimplemented!(),
+            ebpf::ST_DW_XADD => unimplemented!(),
+
+            // BPF_ALU class
+            // TODO Check how overflow works in kernel. Should we &= U32MAX all src register value
+            // before we do the operation?
+            // Cf ((0x11 << 32) - (0x1 << 32)) as u32 VS ((0x11 << 32) as u32 - (0x1 << 32) as u32
+            ebpf::ADD32_IMM => reg[_dst] = (reg[_dst] as i32).wrapping_add(insn.imm) as u64, //((reg[_dst] & U32MAX) + insn.imm  as u64)     & U32MAX,
+            ebpf::ADD32_REG => reg[_dst] = (reg[_dst] as i32).wrapping_add(reg[_src] as i32) as u64, //((reg[_dst] & U32MAX) + (reg[_src] & U32MAX)) & U32MAX,
+            ebpf::SUB32_IMM => reg[_dst] = (reg[_dst] as i32).wrapping_sub(insn.imm) as u64,
+            ebpf::SUB32_REG => reg[_dst] = (reg[_dst] as i32).wrapping_sub(reg[_src] as i32) as u64,
+            ebpf::MUL32_IMM => reg[_dst] = (reg[_dst] as i32).wrapping_mul(insn.imm) as u64,
+            ebpf::MUL32_REG => reg[_dst] = (reg[_dst] as i32).wrapping_mul(reg[_src] as i32) as u64,
+            ebpf::DIV32_IMM if insn.imm as u32 == 0 => reg[_dst] = 0,
+            ebpf::DIV32_IMM => reg[_dst] = (reg[_dst] as u32 / insn.imm as u32) as u64,
+            ebpf::DIV32_REG if reg[_src] as u32 == 0 => reg[_dst] = 0,
+            ebpf::DIV32_REG => reg[_dst] = (reg[_dst] as u32 / reg[_src] as u32) as u64,
+            ebpf::OR32_IMM => reg[_dst] = (reg[_dst] as u32 | insn.imm as u32) as u64,
+            ebpf::OR32_REG => reg[_dst] = (reg[_dst] as u32 | reg[_src] as u32) as u64,
+            ebpf::AND32_IMM => reg[_dst] = (reg[_dst] as u32 & insn.imm as u32) as u64,
+            ebpf::AND32_REG => reg[_dst] = (reg[_dst] as u32 & reg[_src] as u32) as u64,
+            // As for the 64-bit version, we should mask the number of bits to shift with
+            // 0x1f, but .wrappping_shr() already takes care of it for us.
+            ebpf::LSH32_IMM => reg[_dst] = (reg[_dst] as u32).wrapping_shl(insn.imm as u32) as u64,
+            ebpf::LSH32_REG => reg[_dst] = (reg[_dst] as u32).wrapping_shl(reg[_src] as u32) as u64,
+            ebpf::RSH32_IMM => reg[_dst] = (reg[_dst] as u32).wrapping_shr(insn.imm as u32) as u64,
+            ebpf::RSH32_REG => reg[_dst] = (reg[_dst] as u32).wrapping_shr(reg[_src] as u32) as u64,
+            ebpf::NEG32 => {
+                reg[_dst] = (reg[_dst] as i32).wrapping_neg() as u64;
+                reg[_dst] &= U32MAX;
+            }
+            ebpf::MOD32_IMM if insn.imm as u32 == 0 => (),
+            ebpf::MOD32_IMM => reg[_dst] = (reg[_dst] as u32 % insn.imm as u32) as u64,
+            ebpf::MOD32_REG if reg[_src] as u32 == 0 => (),
+            ebpf::MOD32_REG => reg[_dst] = (reg[_dst] as u32 % reg[_src] as u32) as u64,
+            ebpf::XOR32_IMM => reg[_dst] = (reg[_dst] as u32 ^ insn.imm as u32) as u64,
+            ebpf::XOR32_REG => reg[_dst] = (reg[_dst] as u32 ^ reg[_src] as u32) as u64,
+            ebpf::MOV32_IMM => reg[_dst] = insn.imm as u32 as u64,
+            ebpf::MOV32_REG => reg[_dst] = (reg[_src] as u32) as u64,
+            // As for the 64-bit version, we should mask the number of bits to shift with
+            // 0x1f, but .wrappping_shr() already takes care of it for us.
+            ebpf::ARSH32_IMM => {
+                reg[_dst] = (reg[_dst] as i32).wrapping_shr(insn.imm as u32) as u64;
+                reg[_dst] &= U32MAX;
+            }
+            ebpf::ARSH32_REG => {
+                reg[_dst] = (reg[_dst] as i32).wrapping_shr(reg[_src] as u32) as u64;
+                reg[_dst] &= U32MAX;
+            }
+            ebpf::LE => {
+                reg[_dst] = match insn.imm {
+                    16 => (reg[_dst] as u16).to_le() as u64,
+                    32 => (reg[_dst] as u32).to_le() as u64,
+                    64 => reg[_dst].to_le(),
+                    _ => unreachable!(),
+                };
+            }
+            ebpf::BE => {
+                reg[_dst] = match insn.imm {
+                    16 => (reg[_dst] as u16).to_be() as u64,
+                    32 => (reg[_dst] as u32).to_be() as u64,
+                    64 => reg[_dst].to_be(),
+                    _ => unreachable!(),
+                };
+            }
+
+            // BPF_ALU64 class
+            ebpf::ADD64_IMM => reg[_dst] = reg[_dst].wrapping_add(insn.imm as u64),
+            ebpf::ADD64_REG => reg[_dst] = reg[_dst].wrapping_add(reg[_src]),
+            ebpf::SUB64_IMM => reg[_dst] = reg[_dst].wrapping_sub(insn.imm as u64),
+            ebpf::SUB64_REG => reg[_dst] = reg[_dst].wrapping_sub(reg[_src]),
+            ebpf::MUL64_IMM => reg[_dst] = reg[_dst].wrapping_mul(insn.imm as u64),
+            ebpf::MUL64_REG => reg[_dst] = reg[_dst].wrapping_mul(reg[_src]),
+            ebpf::DIV64_IMM if insn.imm == 0 => reg[_dst] = 0,
+            ebpf::DIV64_IMM => reg[_dst] /= insn.imm as u64,
+            ebpf::DIV64_REG if reg[_src] == 0 => reg[_dst] = 0,
+            ebpf::DIV64_REG => reg[_dst] /= reg[_src],
+            ebpf::OR64_IMM => reg[_dst] |= insn.imm as u64,
+            ebpf::OR64_REG => reg[_dst] |= reg[_src],
+            ebpf::AND64_IMM => reg[_dst] &= insn.imm as u64,
+            ebpf::AND64_REG => reg[_dst] &= reg[_src],
+            ebpf::LSH64_IMM => reg[_dst] <<= insn.imm as u64 & SHIFT_MASK_64,
+            ebpf::LSH64_REG => reg[_dst] <<= reg[_src] & SHIFT_MASK_64,
+            ebpf::RSH64_IMM => reg[_dst] >>= insn.imm as u64 & SHIFT_MASK_64,
+            ebpf::RSH64_REG => reg[_dst] >>= reg[_src] & SHIFT_MASK_64,
+            ebpf::NEG64 => reg[_dst] = -(reg[_dst] as i64) as u64,
+            ebpf::MOD64_IMM if insn.imm == 0 => (),
+            ebpf::MOD64_IMM => reg[_dst] %= insn.imm as u64,
+            ebpf::MOD64_REG if reg[_src] == 0 => (),
+            ebpf::MOD64_REG => reg[_dst] %= reg[_src],
+            ebpf::XOR64_IMM => reg[_dst] ^= insn.imm as u64,
+            ebpf::XOR64_REG => reg[_dst] ^= reg[_src],
+            ebpf::MOV64_IMM => reg[_dst] = insn.imm as u64,
+            ebpf::MOV64_REG => reg[_dst] = reg[_src],
+            ebpf::ARSH64_IMM => {
+                reg[_dst] = (reg[_dst] as i64 >> (insn.imm as u64 & SHIFT_MASK_64)) as u64
+            }
+            ebpf::ARSH64_REG => {
+                reg[_dst] = (reg[_dst] as i64 >> (reg[_src] as u64 & SHIFT_MASK_64)) as u64
+            }
+
+            // BPF_JMP class
+            // TODO: check this actually works as expected for signed / unsigned ops
+            ebpf::JA => do_jump(&mut insn_ptr, &insn),
+            ebpf::JEQ_IMM => {
+                if reg[_dst] == insn.imm as u64 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JEQ_REG => {
+                if reg[_dst] == reg[_src] {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JGT_IMM => {
+                if reg[_dst] > insn.imm as u64 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JGT_REG => {
+                if reg[_dst] > reg[_src] {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JGE_IMM => {
+                if reg[_dst] >= insn.imm as u64 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JGE_REG => {
+                if reg[_dst] >= reg[_src] {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JLT_IMM => {
+                if reg[_dst] < insn.imm as u64 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JLT_REG => {
+                if reg[_dst] < reg[_src] {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JLE_IMM => {
+                if reg[_dst] <= insn.imm as u64 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JLE_REG => {
+                if reg[_dst] <= reg[_src] {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JSET_IMM => {
+                if reg[_dst] & insn.imm as u64 != 0 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JSET_REG => {
+                if reg[_dst] & reg[_src] != 0 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JNE_IMM => {
+                if reg[_dst] != insn.imm as u64 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JNE_REG => {
+                if reg[_dst] != reg[_src] {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JSGT_IMM => {
+                if reg[_dst] as i64 > insn.imm as i64 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JSGT_REG => {
+                if reg[_dst] as i64 > reg[_src] as i64 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JSGE_IMM => {
+                if reg[_dst] as i64 >= insn.imm as i64 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JSGE_REG => {
+                if reg[_dst] as i64 >= reg[_src] as i64 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JSLT_IMM => {
+                if (reg[_dst] as i64) < insn.imm as i64 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JSLT_REG => {
+                if (reg[_dst] as i64) < reg[_src] as i64 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JSLE_IMM => {
+                if reg[_dst] as i64 <= insn.imm as i64 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JSLE_REG => {
+                if reg[_dst] as i64 <= reg[_src] as i64 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+
+            // BPF_JMP32 class
+            ebpf::JEQ_IMM32 => {
+                if reg[_dst] as u32 == insn.imm as u32 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JEQ_REG32 => {
+                if reg[_dst] as u32 == reg[_src] as u32 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JGT_IMM32 => {
+                if reg[_dst] as u32 > insn.imm as u32 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JGT_REG32 => {
+                if reg[_dst] as u32 > reg[_src] as u32 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JGE_IMM32 => {
+                if reg[_dst] as u32 >= insn.imm as u32 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JGE_REG32 => {
+                if reg[_dst] as u32 >= reg[_src] as u32 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JLT_IMM32 => {
+                if (reg[_dst] as u32) < insn.imm as u32 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JLT_REG32 => {
+                if (reg[_dst] as u32) < reg[_src] as u32 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JLE_IMM32 => {
+                if reg[_dst] as u32 <= insn.imm as u32 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JLE_REG32 => {
+                if reg[_dst] as u32 <= reg[_src] as u32 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JSET_IMM32 => {
+                if reg[_dst] as u32 & insn.imm as u32 != 0 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JSET_REG32 => {
+                if reg[_dst] as u32 & reg[_src] as u32 != 0 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JNE_IMM32 => {
+                if reg[_dst] as u32 != insn.imm as u32 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JNE_REG32 => {
+                if reg[_dst] as u32 != reg[_src] as u32 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JSGT_IMM32 => {
+                if reg[_dst] as i32 > insn.imm {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JSGT_REG32 => {
+                if reg[_dst] as i32 > reg[_src] as i32 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JSGE_IMM32 => {
+                if reg[_dst] as i32 >= insn.imm {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JSGE_REG32 => {
+                if reg[_dst] as i32 >= reg[_src] as i32 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JSLT_IMM32 => {
+                if (reg[_dst] as i32) < insn.imm {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JSLT_REG32 => {
+                if (reg[_dst] as i32) < reg[_src] as i32 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JSLE_IMM32 => {
+                if reg[_dst] as i32 <= insn.imm {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+            ebpf::JSLE_REG32 => {
+                if reg[_dst] as i32 <= reg[_src] as i32 {
+                    do_jump(&mut insn_ptr, &insn);
+                }
+            }
+
+            // Do not delegate the check to the verifier, since registered functions can be
+            // changed after the program has been verified.
+            ebpf::CALL => {
+                // See https://www.kernel.org/doc/html/latest/bpf/standardization/instruction-set.html#id16
+                let src_reg = _src;
+                let call_func_res = match src_reg {
+                    0 => {
+                        // Handle call by address to external function.
+                        if let Some(function) = helpers.get(&(insn.imm as u32)) {
+                            reg[0] = function(reg[1], reg[2], reg[3], reg[4], reg[5]);
+                            Ok(())
+                        }else {
+                            Err(format!(
+                                "Error: unknown helper function (id: {:#x}) [{}], (instruction #{})",
+                                insn.imm as u32,BPF_FUNC_MAPPER[insn.imm as usize],insn_ptr
+                            ))
+                        }
+                    }
+                    1 => {
+                        // bpf to bpf call
+                        // The function is in the same program, so we can just jump to the address
+                        if stacks.len() >= ebpf::RBPF_MAX_CALL_DEPTH{
+                            Err(format!(
+                                "Error: bpf to bpf call stack limit reached (instruction #{}) max depth: {}",
+                                insn_ptr, ebpf::RBPF_MAX_CALL_DEPTH
+                            ))
+                        }else {
+                            let mut pre_stack = stacks.last_mut().unwrap();
+                            // Save the callee saved registers
+                            pre_stack.save_registers(&reg[6..=9]);
+                            // Save the return address
+                            pre_stack.save_return_address(insn_ptr as u16);
+                            // save the stack pointer
+                            pre_stack.save_sp(reg[10] as u16);
+                            let mut stack = StackFrame::new();
+                            log::trace!("BPF TO BPF CALL: new pc: {} + {} = {}",insn_ptr ,insn.imm,insn_ptr + insn.imm as usize);
+                            reg[10] = stack.as_ptr() as u64 + stack.len() as u64;
+                            stacks.push(stack);
+                            insn_ptr += insn.imm as usize;
+                            Ok(())
+                        }
+                    }
+                    _ =>{
+                        Err(format!(
+                            "Error: the function call type (id: {:#x}) [{}], (instruction #{}) not supported",
+                            insn.imm as u32,BPF_FUNC_MAPPER[insn.imm as usize],insn_ptr
+                        ))
+                    }
+                };
+                if let Err(e) = call_func_res {
+                    Err(Error::new(ErrorKind::Other, e))?;
+                }
+            }
+            ebpf::TAIL_CALL => unimplemented!(),
+            ebpf::EXIT => {
+                if stacks.len() == 1 {
+                    return Ok(reg[0]);
+                } else {
+                    // Pop the stack
+                    stacks.pop();
+                    let stack = stacks.last().unwrap();
+                    // Restore the callee saved registers
+                    reg[6..=9].copy_from_slice(&stack.get_registers());
+                    // Restore the return address
+                    insn_ptr = stack.get_return_address() as usize;
+                    // Restore the stack pointer
+                    reg[10] = stack.get_sp() as u64;
+                    log::trace!("EXIT: new pc: {}", insn_ptr);
+                }
+            }
+
+            _ => unreachable!(),
+        }
+    }
+
+    unreachable!()
+}

kernel/crates/rbpf/src/no_std_error.rs

@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+//! This module provides a simple implementation of the Error struct that is
+//! used as a drop-in replacement for `std::io::Error` when using `rbpf` in `no_std`.
+
+use alloc::string::String;
+
+/// Implementation of Error for no_std applications.
+/// Ensures that the existing code can use it with the same interface
+/// as the Error from std::io::Error.
+#[derive(Debug)]
+pub struct Error {
+    #[allow(dead_code)]
+    kind: ErrorKind,
+    #[allow(dead_code)]
+    error: String,
+}
+
+impl Error {
+    /// New function exposing the same signature as `std::io::Error::new`.
+    #[allow(dead_code)]
+    pub fn new<S: Into<String>>(kind: ErrorKind, error: S) -> Error {
+        Error {
+            kind,
+            error: error.into(),
+        }
+    }
+}
+
+/// The current version of `rbpf` only uses the [`Other`](ErrorKind::Other) variant
+/// from the [std::io::ErrorKind] enum. If a dependency on other variants were
+/// introduced in the future, this enum needs to be updated accordingly to maintain
+/// compatibility with the real `ErrorKind`. The reason all available variants
+/// aren't included in the first place is that [std::io::ErrorKind] exposes
+/// 40 variants, and not all of them are meaningful under `no_std`.
+#[derive(Debug)]
+pub enum ErrorKind {
+    /// The no_std code only uses this variant.
+    #[allow(dead_code)]
+    Other,
+}

kernel/crates/rbpf/src/stack.rs

@@ -0,0 +1,75 @@
+use crate::{ebpf::STACK_SIZE, vec, Vec};
+
+pub struct StackFrame {
+    return_address: u16,
+    saved_registers: [u64; 4],
+    sp: u16,
+    frame: Vec<u8>,
+}
+
+impl StackFrame {
+    /// Create a new stack frame
+    ///
+    /// The stack frame is created with a capacity of `STACK_SIZE` == 512 bytes
+    pub fn new() -> Self {
+        Self {
+            sp: 0,
+            return_address: 0,
+            saved_registers: [0; 4],
+            frame: vec![0; STACK_SIZE],
+        }
+    }
+
+    /// Create a new stack frame with a given capacity
+    #[allow(unused)]
+    pub fn with_capacity(capacity: usize) -> Self {
+        Self {
+            sp: 0,
+            return_address: 0,
+            saved_registers: [0; 4],
+            frame: vec![0; capacity],
+        }
+    }
+
+    /// The capacity of the stack frame
+    pub fn len(&self) -> usize {
+        self.frame.len()
+    }
+
+    pub fn as_ptr(&self) -> *const u8 {
+        self.frame.as_ptr()
+    }
+
+    pub fn as_slice(&self) -> &[u8] {
+        self.frame.as_slice()
+    }
+    /// Save the callee-saved registers
+    pub fn save_registers(&mut self, regs: &[u64]) {
+        self.saved_registers.copy_from_slice(regs);
+    }
+
+    /// Get the callee-saved registers
+    pub fn get_registers(&self) -> [u64; 4] {
+        self.saved_registers
+    }
+
+    /// Save the return address
+    pub fn save_return_address(&mut self, address: u16) {
+        self.return_address = address;
+    }
+
+    /// Get the return address
+    pub fn get_return_address(&self) -> u16 {
+        self.return_address
+    }
+
+    /// Save the stack pointer
+    pub fn save_sp(&mut self, sp: u16) {
+        self.sp = sp;
+    }
+
+    /// Get the stack pointer
+    pub fn get_sp(&self) -> u16 {
+        self.sp
+    }
+}

kernel/crates/rbpf/src/verifier.rs

@@ -0,0 +1,386 @@
+// SPDX-License-Identifier: (Apache-2.0 OR MIT)
+// Derived from uBPF <https://github.com/iovisor/ubpf>
+// Copyright 2015 Big Switch Networks, Inc
+//      (uBPF: safety checks, originally in C)
+// Copyright 2016 6WIND S.A. <quentin.monnet@6wind.com>
+//      (Translation to Rust)
+
+// This “verifier” performs simple checks when the eBPF program is loaded into the VM (before it is
+// interpreted or JIT-compiled). It has nothing to do with the much more elaborated verifier inside
+// Linux kernel. There is no verification regarding the program flow control (should be a Direct
+// Acyclic Graph) or the consistency for registers usage (the verifier of the kernel assigns types
+// to the registers and is much stricter).
+//
+// On the other hand, rbpf is not expected to run in kernel space.
+//
+// Improving the verifier would be nice, but this is not trivial (and Linux kernel is under GPL
+// license, so we cannot copy it).
+//
+// Contrary to the verifier of the Linux kernel, this one does not modify the bytecode at all.
+
+use alloc::format;
+
+use crate::{ebpf, Error, ErrorKind};
+
+fn reject<S: AsRef<str>>(msg: S) -> Result<(), Error> {
+    let full_msg = format!("[Verifier] Error: {}", msg.as_ref());
+    Err(Error::new(ErrorKind::Other, full_msg))
+}
+
+fn check_prog_len(prog: &[u8]) -> Result<(), Error> {
+    if prog.len() % ebpf::INSN_SIZE != 0 {
+        reject(format!(
+            "eBPF program length must be a multiple of {:?} octets",
+            ebpf::INSN_SIZE
+        ))?;
+    }
+    if prog.len() > ebpf::PROG_MAX_SIZE {
+        reject(format!(
+            "eBPF program length limited to {:?}, here {:?}",
+            ebpf::PROG_MAX_INSNS,
+            prog.len() / ebpf::INSN_SIZE
+        ))?;
+    }
+
+    if prog.is_empty() {
+        reject("no program set, call set_program() to load one")?;
+    }
+    let last_opc = ebpf::get_insn(prog, (prog.len() / ebpf::INSN_SIZE) - 1).opc;
+    if last_opc & ebpf::BPF_CLS_MASK != ebpf::BPF_JMP {
+        reject("program does not end with “EXIT” instruction")?;
+    }
+
+    Ok(())
+}
+
+fn check_imm_endian(insn: &ebpf::Insn, insn_ptr: usize) -> Result<(), Error> {
+    match insn.imm {
+        16 | 32 | 64 => Ok(()),
+        _ => reject(format!(
+            "unsupported argument for LE/BE (insn #{insn_ptr:?})"
+        )),
+    }
+}
+
+fn check_load_dw(prog: &[u8], insn_ptr: usize) -> Result<(), Error> {
+    // We know we can reach next insn since we enforce an EXIT insn at the end of program, while
+    // this function should be called only for LD_DW insn, that cannot be last in program.
+    let next_insn = ebpf::get_insn(prog, insn_ptr + 1);
+    if next_insn.opc != 0 {
+        reject(format!("incomplete LD_DW instruction (insn #{insn_ptr:?})"))?;
+    }
+
+    Ok(())
+}
+
+fn check_jmp_offset(prog: &[u8], insn_ptr: usize) -> Result<(), Error> {
+    let insn = ebpf::get_insn(prog, insn_ptr);
+    if insn.off == -1 {
+        reject(format!("infinite loop (insn #{insn_ptr:?})"))?;
+    }
+
+    let dst_insn_ptr = insn_ptr as isize + 1 + insn.off as isize;
+    if dst_insn_ptr < 0 || dst_insn_ptr as usize >= (prog.len() / ebpf::INSN_SIZE) {
+        reject(format!(
+            "jump out of code to #{dst_insn_ptr:?} (insn #{insn_ptr:?})"
+        ))?;
+    }
+
+    let dst_insn = ebpf::get_insn(prog, dst_insn_ptr as usize);
+    if dst_insn.opc == 0 {
+        reject(format!(
+            "jump to middle of LD_DW at #{dst_insn_ptr:?} (insn #{insn_ptr:?})"
+        ))?;
+    }
+
+    Ok(())
+}
+
+fn check_registers(insn: &ebpf::Insn, store: bool, insn_ptr: usize) -> Result<(), Error> {
+    if insn.src > 10 {
+        reject(format!("invalid source register (insn #{insn_ptr:?})"))?;
+    }
+
+    match (insn.dst, store) {
+        (0..=9, _) | (10, true) => Ok(()),
+        (10, false) => reject(format!(
+            "cannot write into register r10 (insn #{insn_ptr:?})"
+        )),
+        (_, _) => reject(format!("invalid destination register (insn #{insn_ptr:?})")),
+    }
+}
+
+pub fn check(prog: &[u8]) -> Result<(), Error> {
+    check_prog_len(prog)?;
+
+    let mut insn_ptr: usize = 0;
+    while insn_ptr * ebpf::INSN_SIZE < prog.len() {
+        let insn = ebpf::get_insn(prog, insn_ptr);
+        let mut store = false;
+
+        match insn.opc {
+            // BPF_LD class
+            ebpf::LD_ABS_B => {}
+            ebpf::LD_ABS_H => {}
+            ebpf::LD_ABS_W => {}
+            ebpf::LD_ABS_DW => {}
+            ebpf::LD_IND_B => {}
+            ebpf::LD_IND_H => {}
+            ebpf::LD_IND_W => {}
+            ebpf::LD_IND_DW => {}
+
+            ebpf::LD_DW_IMM => {
+                store = true;
+                check_load_dw(prog, insn_ptr)?;
+                insn_ptr += 1;
+            }
+
+            // BPF_LDX class
+            ebpf::LD_B_REG => {}
+            ebpf::LD_H_REG => {}
+            ebpf::LD_W_REG => {}
+            ebpf::LD_DW_REG => {}
+
+            // BPF_ST class
+            ebpf::ST_B_IMM => store = true,
+            ebpf::ST_H_IMM => store = true,
+            ebpf::ST_W_IMM => store = true,
+            ebpf::ST_DW_IMM => store = true,
+
+            // BPF_STX class
+            ebpf::ST_B_REG => store = true,
+            ebpf::ST_H_REG => store = true,
+            ebpf::ST_W_REG => store = true,
+            ebpf::ST_DW_REG => store = true,
+            ebpf::ST_W_XADD => {
+                unimplemented!();
+            }
+            ebpf::ST_DW_XADD => {
+                unimplemented!();
+            }
+
+            // BPF_ALU class
+            ebpf::ADD32_IMM => {}
+            ebpf::ADD32_REG => {}
+            ebpf::SUB32_IMM => {}
+            ebpf::SUB32_REG => {}
+            ebpf::MUL32_IMM => {}
+            ebpf::MUL32_REG => {}
+            ebpf::DIV32_IMM => {}
+            ebpf::DIV32_REG => {}
+            ebpf::OR32_IMM => {}
+            ebpf::OR32_REG => {}
+            ebpf::AND32_IMM => {}
+            ebpf::AND32_REG => {}
+            ebpf::LSH32_IMM => {}
+            ebpf::LSH32_REG => {}
+            ebpf::RSH32_IMM => {}
+            ebpf::RSH32_REG => {}
+            ebpf::NEG32 => {}
+            ebpf::MOD32_IMM => {}
+            ebpf::MOD32_REG => {}
+            ebpf::XOR32_IMM => {}
+            ebpf::XOR32_REG => {}
+            ebpf::MOV32_IMM => {}
+            ebpf::MOV32_REG => {}
+            ebpf::ARSH32_IMM => {}
+            ebpf::ARSH32_REG => {}
+            ebpf::LE => {
+                check_imm_endian(&insn, insn_ptr)?;
+            }
+            ebpf::BE => {
+                check_imm_endian(&insn, insn_ptr)?;
+            }
+
+            // BPF_ALU64 class
+            ebpf::ADD64_IMM => {}
+            ebpf::ADD64_REG => {}
+            ebpf::SUB64_IMM => {}
+            ebpf::SUB64_REG => {}
+            ebpf::MUL64_IMM => {}
+            ebpf::MUL64_REG => {}
+            ebpf::DIV64_IMM => {}
+            ebpf::DIV64_REG => {}
+            ebpf::OR64_IMM => {}
+            ebpf::OR64_REG => {}
+            ebpf::AND64_IMM => {}
+            ebpf::AND64_REG => {}
+            ebpf::LSH64_IMM => {}
+            ebpf::LSH64_REG => {}
+            ebpf::RSH64_IMM => {}
+            ebpf::RSH64_REG => {}
+            ebpf::NEG64 => {}
+            ebpf::MOD64_IMM => {}
+            ebpf::MOD64_REG => {}
+            ebpf::XOR64_IMM => {}
+            ebpf::XOR64_REG => {}
+            ebpf::MOV64_IMM => {}
+            ebpf::MOV64_REG => {}
+            ebpf::ARSH64_IMM => {}
+            ebpf::ARSH64_REG => {}
+
+            // BPF_JMP class
+            ebpf::JA => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JEQ_IMM => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JEQ_REG => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JGT_IMM => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JGT_REG => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JGE_IMM => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JGE_REG => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JLT_IMM => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JLT_REG => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JLE_IMM => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JLE_REG => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JSET_IMM => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JSET_REG => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JNE_IMM => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JNE_REG => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JSGT_IMM => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JSGT_REG => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JSGE_IMM => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JSGE_REG => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JSLT_IMM => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JSLT_REG => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JSLE_IMM => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JSLE_REG => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+
+            // BPF_JMP32 class
+            ebpf::JEQ_IMM32 => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JEQ_REG32 => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JGT_IMM32 => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JGT_REG32 => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JGE_IMM32 => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JGE_REG32 => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JLT_IMM32 => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JLT_REG32 => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JLE_IMM32 => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JLE_REG32 => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JSET_IMM32 => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JSET_REG32 => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JNE_IMM32 => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JNE_REG32 => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JSGT_IMM32 => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JSGT_REG32 => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JSGE_IMM32 => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JSGE_REG32 => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JSLT_IMM32 => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JSLT_REG32 => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JSLE_IMM32 => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+            ebpf::JSLE_REG32 => {
+                check_jmp_offset(prog, insn_ptr)?;
+            }
+
+            ebpf::CALL => {}
+            ebpf::TAIL_CALL => {
+                unimplemented!()
+            }
+            ebpf::EXIT => {}
+
+            _ => {
+                reject(format!(
+                    "unknown eBPF opcode {:#2x} (insn #{insn_ptr:?})",
+                    insn.opc
+                ))?;
+            }
+        }
+
+        check_registers(&insn, store, insn_ptr)?;
+
+        insn_ptr += 1;
+    }
+
+    // insn_ptr should now be equal to number of instructions.
+    if insn_ptr != prog.len() / ebpf::INSN_SIZE {
+        reject(format!("jumped out of code to #{insn_ptr:?}"))?;
+    }
+
+    Ok(())
+}

kernel/crates/rbpf/tests/assembler.rs

@@ -0,0 +1,655 @@
+// SPDX-License-Identifier: (Apache-2.0 OR MIT)
+// Copyright 2017 Rich Lane <lanerl@gmail.com>
+
+#![allow(clippy::unreadable_literal)]
+
+extern crate rbpf;
+mod common;
+
+use common::{TCP_SACK_ASM, TCP_SACK_BIN};
+use rbpf::{assembler::assemble, ebpf};
+
+fn asm(src: &str) -> Result<Vec<ebpf::Insn>, String> {
+    Ok(ebpf::to_insn_vec(&(assemble(src))?))
+}
+
+fn insn(opc: u8, dst: u8, src: u8, off: i16, imm: i32) -> ebpf::Insn {
+    ebpf::Insn {
+        opc,
+        dst,
+        src,
+        off,
+        imm,
+    }
+}
+
+#[test]
+fn test_empty() {
+    assert_eq!(asm(""), Ok(vec![]));
+}
+
+// Example for InstructionType::NoOperand.
+#[test]
+fn test_exit() {
+    assert_eq!(asm("exit"), Ok(vec![insn(ebpf::EXIT, 0, 0, 0, 0)]));
+}
+
+// Example for InstructionType::AluBinary.
+#[test]
+fn test_add64() {
+    assert_eq!(
+        asm("add64 r1, r3"),
+        Ok(vec![insn(ebpf::ADD64_REG, 1, 3, 0, 0)])
+    );
+    assert_eq!(
+        asm("add64 r1, 5"),
+        Ok(vec![insn(ebpf::ADD64_IMM, 1, 0, 0, 5)])
+    );
+}
+
+// Example for InstructionType::AluUnary.
+#[test]
+fn test_neg64() {
+    assert_eq!(asm("neg64 r1"), Ok(vec![insn(ebpf::NEG64, 1, 0, 0, 0)]));
+}
+
+// Example for InstructionType::LoadReg.
+#[test]
+fn test_ldxw() {
+    assert_eq!(
+        asm("ldxw r1, [r2+5]"),
+        Ok(vec![insn(ebpf::LD_W_REG, 1, 2, 5, 0)])
+    );
+}
+
+// Example for InstructionType::StoreImm.
+#[test]
+fn test_stw() {
+    assert_eq!(
+        asm("stw [r2+5], 7"),
+        Ok(vec![insn(ebpf::ST_W_IMM, 2, 0, 5, 7)])
+    );
+}
+
+// Example for InstructionType::StoreReg.
+#[test]
+fn test_stxw() {
+    assert_eq!(
+        asm("stxw [r2+5], r8"),
+        Ok(vec![insn(ebpf::ST_W_REG, 2, 8, 5, 0)])
+    );
+}
+
+// Example for InstructionType::JumpUnconditional.
+#[test]
+fn test_ja() {
+    assert_eq!(asm("ja +8"), Ok(vec![insn(ebpf::JA, 0, 0, 8, 0)]));
+    assert_eq!(asm("ja -3"), Ok(vec![insn(ebpf::JA, 0, 0, -3, 0)]));
+}
+
+// Example for InstructionType::JumpConditional.
+#[test]
+fn test_jeq() {
+    assert_eq!(
+        asm("jeq r1, 4, +8"),
+        Ok(vec![insn(ebpf::JEQ_IMM, 1, 0, 8, 4)])
+    );
+    assert_eq!(
+        asm("jeq r1, r3, +8"),
+        Ok(vec![insn(ebpf::JEQ_REG, 1, 3, 8, 0)])
+    );
+}
+
+// Example for InstructionType::Call.
+#[test]
+fn test_call() {
+    assert_eq!(asm("call 300"), Ok(vec![insn(ebpf::CALL, 0, 0, 0, 300)]));
+}
+
+// Example for InstructionType::Endian.
+#[test]
+fn test_be32() {
+    assert_eq!(asm("be32 r1"), Ok(vec![insn(ebpf::BE, 1, 0, 0, 32)]));
+}
+
+// Example for InstructionType::LoadImm.
+#[test]
+fn test_lddw() {
+    assert_eq!(
+        asm("lddw r1, 0x1234abcd5678eeff"),
+        Ok(vec![
+            insn(ebpf::LD_DW_IMM, 1, 0, 0, 0x5678eeff),
+            insn(0, 0, 0, 0, 0x1234abcd)
+        ])
+    );
+    assert_eq!(
+        asm("lddw r1, 0xff11ee22dd33cc44"),
+        Ok(vec![
+            insn(ebpf::LD_DW_IMM, 1, 0, 0, 0xdd33cc44u32 as i32),
+            insn(0, 0, 0, 0, 0xff11ee22u32 as i32)
+        ])
+    );
+}
+
+// Example for InstructionType::LoadAbs.
+#[test]
+fn test_ldabsw() {
+    assert_eq!(asm("ldabsw 1"), Ok(vec![insn(ebpf::LD_ABS_W, 0, 0, 0, 1)]));
+}
+
+// Example for InstructionType::LoadInd.
+#[test]
+fn test_ldindw() {
+    assert_eq!(
+        asm("ldindw r1, 2"),
+        Ok(vec![insn(ebpf::LD_IND_W, 0, 1, 0, 2)])
+    );
+}
+
+// Example for InstructionType::LoadReg.
+#[test]
+fn test_ldxdw() {
+    assert_eq!(
+        asm("ldxdw r1, [r2+3]"),
+        Ok(vec![insn(ebpf::LD_DW_REG, 1, 2, 3, 0)])
+    );
+}
+
+// Example for InstructionType::StoreImm.
+#[test]
+fn test_sth() {
+    assert_eq!(
+        asm("sth [r1+2], 3"),
+        Ok(vec![insn(ebpf::ST_H_IMM, 1, 0, 2, 3)])
+    );
+}
+
+// Example for InstructionType::StoreReg.
+#[test]
+fn test_stxh() {
+    assert_eq!(
+        asm("stxh [r1+2], r3"),
+        Ok(vec![insn(ebpf::ST_H_REG, 1, 3, 2, 0)])
+    );
+}
+
+// Test all supported AluBinary mnemonics.
+#[test]
+fn test_alu_binary() {
+    assert_eq!(
+        asm("add r1, r2
+                    sub r1, r2
+                    mul r1, r2
+                    div r1, r2
+                    or r1, r2
+                    and r1, r2
+                    lsh r1, r2
+                    rsh r1, r2
+                    mod r1, r2
+                    xor r1, r2
+                    mov r1, r2
+                    arsh r1, r2"),
+        Ok(vec![
+            insn(ebpf::ADD64_REG, 1, 2, 0, 0),
+            insn(ebpf::SUB64_REG, 1, 2, 0, 0),
+            insn(ebpf::MUL64_REG, 1, 2, 0, 0),
+            insn(ebpf::DIV64_REG, 1, 2, 0, 0),
+            insn(ebpf::OR64_REG, 1, 2, 0, 0),
+            insn(ebpf::AND64_REG, 1, 2, 0, 0),
+            insn(ebpf::LSH64_REG, 1, 2, 0, 0),
+            insn(ebpf::RSH64_REG, 1, 2, 0, 0),
+            insn(ebpf::MOD64_REG, 1, 2, 0, 0),
+            insn(ebpf::XOR64_REG, 1, 2, 0, 0),
+            insn(ebpf::MOV64_REG, 1, 2, 0, 0),
+            insn(ebpf::ARSH64_REG, 1, 2, 0, 0)
+        ])
+    );
+
+    assert_eq!(
+        asm("add r1, 2
+                    sub r1, 2
+                    mul r1, 2
+                    div r1, 2
+                    or r1, 2
+                    and r1, 2
+                    lsh r1, 2
+                    rsh r1, 2
+                    mod r1, 2
+                    xor r1, 2
+                    mov r1, 2
+                    arsh r1, 2"),
+        Ok(vec![
+            insn(ebpf::ADD64_IMM, 1, 0, 0, 2),
+            insn(ebpf::SUB64_IMM, 1, 0, 0, 2),
+            insn(ebpf::MUL64_IMM, 1, 0, 0, 2),
+            insn(ebpf::DIV64_IMM, 1, 0, 0, 2),
+            insn(ebpf::OR64_IMM, 1, 0, 0, 2),
+            insn(ebpf::AND64_IMM, 1, 0, 0, 2),
+            insn(ebpf::LSH64_IMM, 1, 0, 0, 2),
+            insn(ebpf::RSH64_IMM, 1, 0, 0, 2),
+            insn(ebpf::MOD64_IMM, 1, 0, 0, 2),
+            insn(ebpf::XOR64_IMM, 1, 0, 0, 2),
+            insn(ebpf::MOV64_IMM, 1, 0, 0, 2),
+            insn(ebpf::ARSH64_IMM, 1, 0, 0, 2)
+        ])
+    );
+
+    assert_eq!(
+        asm("add64 r1, r2
+                    sub64 r1, r2
+                    mul64 r1, r2
+                    div64 r1, r2
+                    or64 r1, r2
+                    and64 r1, r2
+                    lsh64 r1, r2
+                    rsh64 r1, r2
+                    mod64 r1, r2
+                    xor64 r1, r2
+                    mov64 r1, r2
+                    arsh64 r1, r2"),
+        Ok(vec![
+            insn(ebpf::ADD64_REG, 1, 2, 0, 0),
+            insn(ebpf::SUB64_REG, 1, 2, 0, 0),
+            insn(ebpf::MUL64_REG, 1, 2, 0, 0),
+            insn(ebpf::DIV64_REG, 1, 2, 0, 0),
+            insn(ebpf::OR64_REG, 1, 2, 0, 0),
+            insn(ebpf::AND64_REG, 1, 2, 0, 0),
+            insn(ebpf::LSH64_REG, 1, 2, 0, 0),
+            insn(ebpf::RSH64_REG, 1, 2, 0, 0),
+            insn(ebpf::MOD64_REG, 1, 2, 0, 0),
+            insn(ebpf::XOR64_REG, 1, 2, 0, 0),
+            insn(ebpf::MOV64_REG, 1, 2, 0, 0),
+            insn(ebpf::ARSH64_REG, 1, 2, 0, 0)
+        ])
+    );
+
+    assert_eq!(
+        asm("add64 r1, 2
+                    sub64 r1, 2
+                    mul64 r1, 2
+                    div64 r1, 2
+                    or64 r1, 2
+                    and64 r1, 2
+                    lsh64 r1, 2
+                    rsh64 r1, 2
+                    mod64 r1, 2
+                    xor64 r1, 2
+                    mov64 r1, 2
+                    arsh64 r1, 2"),
+        Ok(vec![
+            insn(ebpf::ADD64_IMM, 1, 0, 0, 2),
+            insn(ebpf::SUB64_IMM, 1, 0, 0, 2),
+            insn(ebpf::MUL64_IMM, 1, 0, 0, 2),
+            insn(ebpf::DIV64_IMM, 1, 0, 0, 2),
+            insn(ebpf::OR64_IMM, 1, 0, 0, 2),
+            insn(ebpf::AND64_IMM, 1, 0, 0, 2),
+            insn(ebpf::LSH64_IMM, 1, 0, 0, 2),
+            insn(ebpf::RSH64_IMM, 1, 0, 0, 2),
+            insn(ebpf::MOD64_IMM, 1, 0, 0, 2),
+            insn(ebpf::XOR64_IMM, 1, 0, 0, 2),
+            insn(ebpf::MOV64_IMM, 1, 0, 0, 2),
+            insn(ebpf::ARSH64_IMM, 1, 0, 0, 2)
+        ])
+    );
+
+    assert_eq!(
+        asm("add32 r1, r2
+                    sub32 r1, r2
+                    mul32 r1, r2
+                    div32 r1, r2
+                    or32 r1, r2
+                    and32 r1, r2
+                    lsh32 r1, r2
+                    rsh32 r1, r2
+                    mod32 r1, r2
+                    xor32 r1, r2
+                    mov32 r1, r2
+                    arsh32 r1, r2"),
+        Ok(vec![
+            insn(ebpf::ADD32_REG, 1, 2, 0, 0),
+            insn(ebpf::SUB32_REG, 1, 2, 0, 0),
+            insn(ebpf::MUL32_REG, 1, 2, 0, 0),
+            insn(ebpf::DIV32_REG, 1, 2, 0, 0),
+            insn(ebpf::OR32_REG, 1, 2, 0, 0),
+            insn(ebpf::AND32_REG, 1, 2, 0, 0),
+            insn(ebpf::LSH32_REG, 1, 2, 0, 0),
+            insn(ebpf::RSH32_REG, 1, 2, 0, 0),
+            insn(ebpf::MOD32_REG, 1, 2, 0, 0),
+            insn(ebpf::XOR32_REG, 1, 2, 0, 0),
+            insn(ebpf::MOV32_REG, 1, 2, 0, 0),
+            insn(ebpf::ARSH32_REG, 1, 2, 0, 0)
+        ])
+    );
+
+    assert_eq!(
+        asm("add32 r1, 2
+                    sub32 r1, 2
+                    mul32 r1, 2
+                    div32 r1, 2
+                    or32 r1, 2
+                    and32 r1, 2
+                    lsh32 r1, 2
+                    rsh32 r1, 2
+                    mod32 r1, 2
+                    xor32 r1, 2
+                    mov32 r1, 2
+                    arsh32 r1, 2"),
+        Ok(vec![
+            insn(ebpf::ADD32_IMM, 1, 0, 0, 2),
+            insn(ebpf::SUB32_IMM, 1, 0, 0, 2),
+            insn(ebpf::MUL32_IMM, 1, 0, 0, 2),
+            insn(ebpf::DIV32_IMM, 1, 0, 0, 2),
+            insn(ebpf::OR32_IMM, 1, 0, 0, 2),
+            insn(ebpf::AND32_IMM, 1, 0, 0, 2),
+            insn(ebpf::LSH32_IMM, 1, 0, 0, 2),
+            insn(ebpf::RSH32_IMM, 1, 0, 0, 2),
+            insn(ebpf::MOD32_IMM, 1, 0, 0, 2),
+            insn(ebpf::XOR32_IMM, 1, 0, 0, 2),
+            insn(ebpf::MOV32_IMM, 1, 0, 0, 2),
+            insn(ebpf::ARSH32_IMM, 1, 0, 0, 2)
+        ])
+    );
+}
+
+// Test all supported AluUnary mnemonics.
+#[test]
+fn test_alu_unary() {
+    assert_eq!(
+        asm("neg r1
+                    neg64 r1
+                    neg32 r1"),
+        Ok(vec![
+            insn(ebpf::NEG64, 1, 0, 0, 0),
+            insn(ebpf::NEG64, 1, 0, 0, 0),
+            insn(ebpf::NEG32, 1, 0, 0, 0)
+        ])
+    );
+}
+
+// Test all supported LoadAbs mnemonics.
+#[test]
+fn test_load_abs() {
+    assert_eq!(
+        asm("ldabsw 1
+                    ldabsh 1
+                    ldabsb 1
+                    ldabsdw 1"),
+        Ok(vec![
+            insn(ebpf::LD_ABS_W, 0, 0, 0, 1),
+            insn(ebpf::LD_ABS_H, 0, 0, 0, 1),
+            insn(ebpf::LD_ABS_B, 0, 0, 0, 1),
+            insn(ebpf::LD_ABS_DW, 0, 0, 0, 1)
+        ])
+    );
+}
+
+// Test all supported LoadInd mnemonics.
+#[test]
+fn test_load_ind() {
+    assert_eq!(
+        asm("ldindw r1, 2
+                    ldindh r1, 2
+                    ldindb r1, 2
+                    ldinddw r1, 2"),
+        Ok(vec![
+            insn(ebpf::LD_IND_W, 0, 1, 0, 2),
+            insn(ebpf::LD_IND_H, 0, 1, 0, 2),
+            insn(ebpf::LD_IND_B, 0, 1, 0, 2),
+            insn(ebpf::LD_IND_DW, 0, 1, 0, 2)
+        ])
+    );
+}
+
+// Test all supported LoadReg mnemonics.
+#[test]
+fn test_load_reg() {
+    assert_eq!(
+        asm("ldxw r1, [r2+3]
+                    ldxh r1, [r2+3]
+                    ldxb r1, [r2+3]
+                    ldxdw r1, [r2+3]"),
+        Ok(vec![
+            insn(ebpf::LD_W_REG, 1, 2, 3, 0),
+            insn(ebpf::LD_H_REG, 1, 2, 3, 0),
+            insn(ebpf::LD_B_REG, 1, 2, 3, 0),
+            insn(ebpf::LD_DW_REG, 1, 2, 3, 0)
+        ])
+    );
+}
+
+// Test all supported StoreImm mnemonics.
+#[test]
+fn test_store_imm() {
+    assert_eq!(
+        asm("stw [r1+2], 3
+                    sth [r1+2], 3
+                    stb [r1+2], 3
+                    stdw [r1+2], 3"),
+        Ok(vec![
+            insn(ebpf::ST_W_IMM, 1, 0, 2, 3),
+            insn(ebpf::ST_H_IMM, 1, 0, 2, 3),
+            insn(ebpf::ST_B_IMM, 1, 0, 2, 3),
+            insn(ebpf::ST_DW_IMM, 1, 0, 2, 3)
+        ])
+    );
+}
+
+// Test all supported StoreReg mnemonics.
+#[test]
+fn test_store_reg() {
+    assert_eq!(
+        asm("stxw [r1+2], r3
+                    stxh [r1+2], r3
+                    stxb [r1+2], r3
+                    stxdw [r1+2], r3"),
+        Ok(vec![
+            insn(ebpf::ST_W_REG, 1, 3, 2, 0),
+            insn(ebpf::ST_H_REG, 1, 3, 2, 0),
+            insn(ebpf::ST_B_REG, 1, 3, 2, 0),
+            insn(ebpf::ST_DW_REG, 1, 3, 2, 0)
+        ])
+    );
+}
+
+// Test all supported JumpConditional mnemonics.
+#[test]
+fn test_jump_conditional() {
+    assert_eq!(
+        asm("jeq r1, r2, +3
+                    jgt r1, r2, +3
+                    jge r1, r2, +3
+                    jlt r1, r2, +3
+                    jle r1, r2, +3
+                    jset r1, r2, +3
+                    jne r1, r2, +3
+                    jsgt r1, r2, +3
+                    jsge r1, r2, +3
+                    jslt r1, r2, +3
+                    jsle r1, r2, +3"),
+        Ok(vec![
+            insn(ebpf::JEQ_REG, 1, 2, 3, 0),
+            insn(ebpf::JGT_REG, 1, 2, 3, 0),
+            insn(ebpf::JGE_REG, 1, 2, 3, 0),
+            insn(ebpf::JLT_REG, 1, 2, 3, 0),
+            insn(ebpf::JLE_REG, 1, 2, 3, 0),
+            insn(ebpf::JSET_REG, 1, 2, 3, 0),
+            insn(ebpf::JNE_REG, 1, 2, 3, 0),
+            insn(ebpf::JSGT_REG, 1, 2, 3, 0),
+            insn(ebpf::JSGE_REG, 1, 2, 3, 0),
+            insn(ebpf::JSLT_REG, 1, 2, 3, 0),
+            insn(ebpf::JSLE_REG, 1, 2, 3, 0)
+        ])
+    );
+
+    assert_eq!(
+        asm("jeq r1, 2, +3
+                    jgt r1, 2, +3
+                    jge r1, 2, +3
+                    jlt r1, 2, +3
+                    jle r1, 2, +3
+                    jset r1, 2, +3
+                    jne r1, 2, +3
+                    jsgt r1, 2, +3
+                    jsge r1, 2, +3
+                    jslt r1, 2, +3
+                    jsle r1, 2, +3"),
+        Ok(vec![
+            insn(ebpf::JEQ_IMM, 1, 0, 3, 2),
+            insn(ebpf::JGT_IMM, 1, 0, 3, 2),
+            insn(ebpf::JGE_IMM, 1, 0, 3, 2),
+            insn(ebpf::JLT_IMM, 1, 0, 3, 2),
+            insn(ebpf::JLE_IMM, 1, 0, 3, 2),
+            insn(ebpf::JSET_IMM, 1, 0, 3, 2),
+            insn(ebpf::JNE_IMM, 1, 0, 3, 2),
+            insn(ebpf::JSGT_IMM, 1, 0, 3, 2),
+            insn(ebpf::JSGE_IMM, 1, 0, 3, 2),
+            insn(ebpf::JSLT_IMM, 1, 0, 3, 2),
+            insn(ebpf::JSLE_IMM, 1, 0, 3, 2)
+        ])
+    );
+
+    assert_eq!(
+        asm("jeq32 r1, r2, +3
+                    jgt32 r1, r2, +3
+                    jge32 r1, r2, +3
+                    jlt32 r1, r2, +3
+                    jle32 r1, r2, +3
+                    jset32 r1, r2, +3
+                    jne32 r1, r2, +3
+                    jsgt32 r1, r2, +3
+                    jsge32 r1, r2, +3
+                    jslt32 r1, r2, +3
+                    jsle32 r1, r2, +3"),
+        Ok(vec![
+            insn(ebpf::JEQ_REG32, 1, 2, 3, 0),
+            insn(ebpf::JGT_REG32, 1, 2, 3, 0),
+            insn(ebpf::JGE_REG32, 1, 2, 3, 0),
+            insn(ebpf::JLT_REG32, 1, 2, 3, 0),
+            insn(ebpf::JLE_REG32, 1, 2, 3, 0),
+            insn(ebpf::JSET_REG32, 1, 2, 3, 0),
+            insn(ebpf::JNE_REG32, 1, 2, 3, 0),
+            insn(ebpf::JSGT_REG32, 1, 2, 3, 0),
+            insn(ebpf::JSGE_REG32, 1, 2, 3, 0),
+            insn(ebpf::JSLT_REG32, 1, 2, 3, 0),
+            insn(ebpf::JSLE_REG32, 1, 2, 3, 0)
+        ])
+    );
+
+    assert_eq!(
+        asm("jeq32 r1, 2, +3
+                    jgt32 r1, 2, +3
+                    jge32 r1, 2, +3
+                    jlt32 r1, 2, +3
+                    jle32 r1, 2, +3
+                    jset32 r1, 2, +3
+                    jne32 r1, 2, +3
+                    jsgt32 r1, 2, +3
+                    jsge32 r1, 2, +3
+                    jslt32 r1, 2, +3
+                    jsle32 r1, 2, +3"),
+        Ok(vec![
+            insn(ebpf::JEQ_IMM32, 1, 0, 3, 2),
+            insn(ebpf::JGT_IMM32, 1, 0, 3, 2),
+            insn(ebpf::JGE_IMM32, 1, 0, 3, 2),
+            insn(ebpf::JLT_IMM32, 1, 0, 3, 2),
+            insn(ebpf::JLE_IMM32, 1, 0, 3, 2),
+            insn(ebpf::JSET_IMM32, 1, 0, 3, 2),
+            insn(ebpf::JNE_IMM32, 1, 0, 3, 2),
+            insn(ebpf::JSGT_IMM32, 1, 0, 3, 2),
+            insn(ebpf::JSGE_IMM32, 1, 0, 3, 2),
+            insn(ebpf::JSLT_IMM32, 1, 0, 3, 2),
+            insn(ebpf::JSLE_IMM32, 1, 0, 3, 2)
+        ])
+    );
+}
+
+// Test all supported Endian mnemonics.
+#[test]
+fn test_endian() {
+    assert_eq!(
+        asm("be16 r1
+                    be32 r1
+                    be64 r1
+                    le16 r1
+                    le32 r1
+                    le64 r1"),
+        Ok(vec![
+            insn(ebpf::BE, 1, 0, 0, 16),
+            insn(ebpf::BE, 1, 0, 0, 32),
+            insn(ebpf::BE, 1, 0, 0, 64),
+            insn(ebpf::LE, 1, 0, 0, 16),
+            insn(ebpf::LE, 1, 0, 0, 32),
+            insn(ebpf::LE, 1, 0, 0, 64)
+        ])
+    );
+}
+
+#[test]
+fn test_large_immediate() {
+    assert_eq!(
+        asm("add64 r1, 2147483647"),
+        Ok(vec![insn(ebpf::ADD64_IMM, 1, 0, 0, 2147483647)])
+    );
+    assert_eq!(
+        asm("add64 r1, -2147483648"),
+        Ok(vec![insn(ebpf::ADD64_IMM, 1, 0, 0, -2147483648)])
+    );
+}
+
+#[test]
+fn test_tcp_sack() {
+    assert_eq!(assemble(TCP_SACK_ASM), Ok(TCP_SACK_BIN.to_vec()));
+}
+
+#[test]
+fn test_error_invalid_instruction() {
+    assert_eq!(asm("abcd"), Err("Invalid instruction \"abcd\"".to_string()));
+}
+
+#[test]
+fn test_error_unexpected_operands() {
+    assert_eq!(
+        asm("add 1, 2"),
+        Err("Failed to encode add: Unexpected operands: [Integer(1), Integer(2)]".to_string())
+    );
+}
+
+#[test]
+fn test_error_too_many_operands() {
+    assert_eq!(
+        asm("add 1, 2, 3, 4"),
+        Err("Failed to encode add: Too many operands".to_string())
+    );
+}
+
+#[test]
+fn test_error_operands_out_of_range() {
+    assert_eq!(
+        asm("add r16, r2"),
+        Err("Failed to encode add: Invalid destination register 16".to_string())
+    );
+    assert_eq!(
+        asm("add r1, r16"),
+        Err("Failed to encode add: Invalid source register 16".to_string())
+    );
+    assert_eq!(
+        asm("ja -32769"),
+        Err("Failed to encode ja: Invalid offset -32769".to_string())
+    );
+    assert_eq!(
+        asm("ja 32768"),
+        Err("Failed to encode ja: Invalid offset 32768".to_string())
+    );
+    assert_eq!(
+        asm("add r1, 4294967296"),
+        Err("Failed to encode add: Invalid immediate 4294967296".to_string())
+    );
+    assert_eq!(
+        asm("add r1, 2147483648"),
+        Err("Failed to encode add: Invalid immediate 2147483648".to_string())
+    );
+    assert_eq!(
+        asm("add r1, -2147483649"),
+        Err("Failed to encode add: Invalid immediate -2147483649".to_string())
+    );
+}

kernel/crates/rbpf/tests/common.rs

@@ -0,0 +1,97 @@
+// SPDX-License-Identifier: (Apache-2.0 OR MIT)
+// Converted from the tests for uBPF <https://github.com/iovisor/ubpf>
+// Copyright 2015 Big Switch Networks, Inc
+// Copyright 2016 6WIND S.A. <quentin.monnet@6wind.com>
+
+// Assembly code and data for tcp_sack testcases.
+
+#[allow(dead_code)]
+pub const TCP_SACK_ASM: &str = "
+    ldxb r2, [r1+12]
+    ldxb r3, [r1+13]
+    lsh r3, 0x8
+    or r3, r2
+    mov r0, 0x0
+    jne r3, 0x8, +37
+    ldxb r2, [r1+23]
+    jne r2, 0x6, +35
+    ldxb r2, [r1+14]
+    add r1, 0xe
+    and r2, 0xf
+    lsh r2, 0x2
+    add r1, r2
+    mov r0, 0x0
+    ldxh r4, [r1+12]
+    add r1, 0x14
+    rsh r4, 0x2
+    and r4, 0x3c
+    mov r2, r4
+    add r2, -20
+    mov r5, 0x15
+    mov r3, 0x0
+    jgt r5, r4, +20
+    mov r5, r3
+    lsh r5, 0x20
+    arsh r5, 0x20
+    mov r4, r1
+    add r4, r5
+    ldxb r5, [r4]
+    jeq r5, 0x1, +4
+    jeq r5, 0x0, +12
+    mov r6, r3
+    jeq r5, 0x5, +9
+    ja +2
+    add r3, 0x1
+    mov r6, r3
+    ldxb r3, [r4+1]
+    add r3, r6
+    lsh r3, 0x20
+    arsh r3, 0x20
+    jsgt r2, r3, -18
+    ja +1
+    mov r0, 0x1
+    exit";
+
+#[allow(dead_code)]
+pub const TCP_SACK_BIN: [u8; 352] = [
+    0x71, 0x12, 0x0c, 0x00, 0x00, 0x00, 0x00, 0x00, 0x71, 0x13, 0x0d, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x67, 0x03, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x4f, 0x23, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0xb7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x55, 0x03, 0x25, 0x00, 0x08, 0x00, 0x00, 0x00,
+    0x71, 0x12, 0x17, 0x00, 0x00, 0x00, 0x00, 0x00, 0x55, 0x02, 0x23, 0x00, 0x06, 0x00, 0x00, 0x00,
+    0x71, 0x12, 0x0e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x07, 0x01, 0x00, 0x00, 0x0e, 0x00, 0x00, 0x00,
+    0x57, 0x02, 0x00, 0x00, 0x0f, 0x00, 0x00, 0x00, 0x67, 0x02, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00,
+    0x0f, 0x21, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xb7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x69, 0x14, 0x0c, 0x00, 0x00, 0x00, 0x00, 0x00, 0x07, 0x01, 0x00, 0x00, 0x14, 0x00, 0x00, 0x00,
+    0x77, 0x04, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x57, 0x04, 0x00, 0x00, 0x3c, 0x00, 0x00, 0x00,
+    0xbf, 0x42, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x07, 0x02, 0x00, 0x00, 0xec, 0xff, 0xff, 0xff,
+    0xb7, 0x05, 0x00, 0x00, 0x15, 0x00, 0x00, 0x00, 0xb7, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x2d, 0x45, 0x14, 0x00, 0x00, 0x00, 0x00, 0x00, 0xbf, 0x35, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x67, 0x05, 0x00, 0x00, 0x20, 0x00, 0x00, 0x00, 0xc7, 0x05, 0x00, 0x00, 0x20, 0x00, 0x00, 0x00,
+    0xbf, 0x14, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0f, 0x54, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x71, 0x45, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x15, 0x05, 0x04, 0x00, 0x01, 0x00, 0x00, 0x00,
+    0x15, 0x05, 0x0c, 0x00, 0x00, 0x00, 0x00, 0x00, 0xbf, 0x36, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x15, 0x05, 0x09, 0x00, 0x05, 0x00, 0x00, 0x00, 0x05, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x07, 0x03, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0xbf, 0x36, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x71, 0x43, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0f, 0x63, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x67, 0x03, 0x00, 0x00, 0x20, 0x00, 0x00, 0x00, 0xc7, 0x03, 0x00, 0x00, 0x20, 0x00, 0x00, 0x00,
+    0x6d, 0x32, 0xee, 0xff, 0x00, 0x00, 0x00, 0x00, 0x05, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0xb7, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+];
+
+#[allow(dead_code)]
+pub const TCP_SACK_MATCH: [u8; 78] = [
+    0x00, 0x26, 0x62, 0x2f, 0x47, 0x87, 0x00, 0x1d, 0x60, 0xb3, 0x01, 0x84, 0x08, 0x00, 0x45, 0x00,
+    0x00, 0x40, 0xa8, 0xde, 0x40, 0x00, 0x40, 0x06, 0x9d, 0x58, 0xc0, 0xa8, 0x01, 0x03, 0x3f, 0x74,
+    0xf3, 0x61, 0xe5, 0xc0, 0x00, 0x50, 0xe5, 0x94, 0x3f, 0x77, 0xa3, 0xc4, 0xc4, 0x80, 0xb0, 0x10,
+    0x01, 0x3e, 0x34, 0xb6, 0x00, 0x00, 0x01, 0x01, 0x08, 0x0a, 0x00, 0x17, 0x95, 0x6f, 0x8d, 0x9d,
+    0x9e, 0x27, 0x01, 0x01, 0x05, 0x0a, 0xa3, 0xc4, 0xca, 0x28, 0xa3, 0xc4, 0xcf, 0xd0,
+];
+
+#[allow(dead_code)]
+pub const TCP_SACK_NOMATCH: [u8; 66] = [
+    0x00, 0x26, 0x62, 0x2f, 0x47, 0x87, 0x00, 0x1d, 0x60, 0xb3, 0x01, 0x84, 0x08, 0x00, 0x45, 0x00,
+    0x00, 0x40, 0xa8, 0xde, 0x40, 0x00, 0x40, 0x06, 0x9d, 0x58, 0xc0, 0xa8, 0x01, 0x03, 0x3f, 0x74,
+    0xf3, 0x61, 0xe5, 0xc0, 0x00, 0x50, 0xe5, 0x94, 0x3f, 0x77, 0xa3, 0xc4, 0xc4, 0x80, 0x80, 0x10,
+    0x01, 0x3e, 0x34, 0xb6, 0x00, 0x00, 0x01, 0x01, 0x08, 0x0a, 0x00, 0x17, 0x95, 0x6f, 0x8d, 0x9d,
+    0x9e, 0x27,
+];

kernel/crates/rbpf/tests/disassembler.rs

@@ -0,0 +1,377 @@
+// SPDX-License-Identifier: (Apache-2.0 OR MIT)
+// Copyright 2017 Jan-Erik Rediger <badboy@archlinux.us>
+//
+// Adopted from tests in `tests/assembler.rs`
+
+extern crate rbpf;
+mod common;
+
+use rbpf::{assembler::assemble, disassembler::to_insn_vec};
+
+// Using a macro to keep actual line numbers in failure output
+macro_rules! disasm {
+    ($src:expr) => {{
+        let src = $src;
+        let asm = assemble(src).expect("Can't assemble from string");
+        let insn = to_insn_vec(&asm);
+        let reasm = insn
+            .into_iter()
+            .map(|ins| ins.desc)
+            .collect::<Vec<_>>()
+            .join("\n");
+
+        assert_eq!(src, reasm);
+    }};
+}
+
+#[test]
+fn test_empty() {
+    disasm!("");
+}
+
+// Example for InstructionType::NoOperand.
+#[test]
+fn test_exit() {
+    disasm!("exit");
+}
+
+// Example for InstructionType::AluBinary.
+#[test]
+fn test_add64() {
+    disasm!("add64 r1, r3");
+    disasm!("add64 r1, 0x5");
+}
+
+// Example for InstructionType::AluUnary.
+#[test]
+fn test_neg64() {
+    disasm!("neg64 r1");
+}
+
+// Example for InstructionType::LoadReg.
+#[test]
+fn test_ldxw() {
+    disasm!("ldxw r1, [r2+0x5]");
+}
+
+// Example for InstructionType::StoreImm.
+#[test]
+fn test_stw() {
+    disasm!("stw [r2+0x5], 0x7");
+}
+
+// Example for InstructionType::StoreReg.
+#[test]
+fn test_stxw() {
+    disasm!("stxw [r2+0x5], r8");
+}
+
+// Example for InstructionType::JumpUnconditional.
+#[test]
+fn test_ja() {
+    disasm!("ja +0x8");
+}
+
+// Example for InstructionType::JumpConditional.
+#[test]
+fn test_jeq() {
+    disasm!("jeq r1, 0x4, +0x8");
+    disasm!("jeq r1, r3, +0x8");
+}
+
+// Example for InstructionType::Call.
+#[test]
+fn test_call() {
+    disasm!("call 0x3");
+}
+
+// Example for InstructionType::Endian.
+#[test]
+fn test_be32() {
+    disasm!("be32 r1");
+}
+
+// Example for InstructionType::LoadImm.
+#[test]
+fn test_lddw() {
+    disasm!("lddw r1, 0x1234abcd5678eeff");
+    disasm!("lddw r1, 0xff11ee22dd33cc44");
+}
+
+// Example for InstructionType::LoadAbs.
+#[test]
+fn test_ldabsw() {
+    disasm!("ldabsw 0x1");
+}
+
+// Example for InstructionType::LoadInd.
+#[test]
+fn test_ldindw() {
+    disasm!("ldindw r1, 0x2");
+}
+
+// Example for InstructionType::LoadReg.
+#[test]
+fn test_ldxdw() {
+    disasm!("ldxdw r1, [r2+0x3]");
+}
+
+// Example for InstructionType::StoreImm.
+#[test]
+fn test_sth() {
+    disasm!("sth [r1+0x2], 0x3");
+}
+
+// Example for InstructionType::StoreReg.
+#[test]
+fn test_stxh() {
+    disasm!("stxh [r1+0x2], r3");
+}
+
+// Test all supported AluBinary mnemonics.
+#[test]
+fn test_alu_binary() {
+    disasm!(
+        "add64 r1, r2
+sub64 r1, r2
+mul64 r1, r2
+div64 r1, r2
+or64 r1, r2
+and64 r1, r2
+lsh64 r1, r2
+rsh64 r1, r2
+mod64 r1, r2
+xor64 r1, r2
+mov64 r1, r2
+arsh64 r1, r2"
+    );
+
+    disasm!(
+        "add64 r1, 0x2
+sub64 r1, 0x2
+mul64 r1, 0x2
+div64 r1, 0x2
+or64 r1, 0x2
+and64 r1, 0x2
+lsh64 r1, 0x2
+rsh64 r1, 0x2
+mod64 r1, 0x2
+xor64 r1, 0x2
+mov64 r1, 0x2
+arsh64 r1, 0x2"
+    );
+
+    disasm!(
+        "add32 r1, r2
+sub32 r1, r2
+mul32 r1, r2
+div32 r1, r2
+or32 r1, r2
+and32 r1, r2
+lsh32 r1, r2
+rsh32 r1, r2
+mod32 r1, r2
+xor32 r1, r2
+mov32 r1, r2
+arsh32 r1, r2"
+    );
+
+    disasm!(
+        "add32 r1, 0x2
+sub32 r1, 0x2
+mul32 r1, 0x2
+div32 r1, 0x2
+or32 r1, 0x2
+and32 r1, 0x2
+lsh32 r1, 0x2
+rsh32 r1, 0x2
+mod32 r1, 0x2
+xor32 r1, 0x2
+mov32 r1, 0x2
+arsh32 r1, 0x2"
+    );
+}
+
+// Test all supported AluUnary mnemonics.
+#[test]
+fn test_alu_unary() {
+    disasm!(
+        "neg64 r1
+neg32 r1"
+    );
+}
+
+// Test all supported LoadAbs mnemonics.
+#[test]
+fn test_load_abs() {
+    disasm!(
+        "ldabsw 0x1
+ldabsh 0x1
+ldabsb 0x1
+ldabsdw 0x1"
+    );
+}
+
+// Test all supported LoadInd mnemonics.
+#[test]
+fn test_load_ind() {
+    disasm!(
+        "ldindw r1, 0x2
+ldindh r1, 0x2
+ldindb r1, 0x2
+ldinddw r1, 0x2"
+    );
+}
+
+// Test all supported LoadReg mnemonics.
+#[test]
+fn test_load_reg() {
+    disasm!(
+        r"ldxw r1, [r2+0x3]
+ldxh r1, [r2+0x3]
+ldxb r1, [r2+0x3]
+ldxdw r1, [r2+0x3]"
+    );
+}
+
+// Test all supported StoreImm mnemonics.
+#[test]
+fn test_store_imm() {
+    disasm!(
+        "stw [r1+0x2], 0x3
+sth [r1+0x2], 0x3
+stb [r1+0x2], 0x3
+stdw [r1+0x2], 0x3"
+    );
+}
+
+// Test all supported StoreReg mnemonics.
+#[test]
+fn test_store_reg() {
+    disasm!(
+        "stxw [r1+0x2], r3
+stxh [r1+0x2], r3
+stxb [r1+0x2], r3
+stxdw [r1+0x2], r3"
+    );
+}
+
+// Test all supported JumpConditional mnemonics.
+#[test]
+fn test_jump_conditional() {
+    disasm!(
+        "jeq r1, r2, +0x3
+jgt r1, r2, +0x3
+jge r1, r2, +0x3
+jlt r1, r2, +0x3
+jle r1, r2, +0x3
+jset r1, r2, +0x3
+jne r1, r2, +0x3
+jsgt r1, r2, +0x3
+jsge r1, r2, -0x3
+jslt r1, r2, +0x3
+jsle r1, r2, -0x3"
+    );
+
+    disasm!(
+        "jeq r1, 0x2, +0x3
+jgt r1, 0x2, +0x3
+jge r1, 0x2, +0x3
+jlt r1, 0x2, +0x3
+jle r1, 0x2, +0x3
+jset r1, 0x2, +0x3
+jne r1, 0x2, +0x3
+jsgt r1, 0x2, +0x3
+jsge r1, 0x2, -0x3
+jslt r1, 0x2, +0x3
+jsle r1, 0x2, -0x3"
+    );
+
+    disasm!(
+        "jeq32 r1, r2, +0x3
+jgt32 r1, r2, +0x3
+jge32 r1, r2, +0x3
+jlt32 r1, r2, +0x3
+jle32 r1, r2, +0x3
+jset32 r1, r2, +0x3
+jne32 r1, r2, +0x3
+jsgt32 r1, r2, +0x3
+jsge32 r1, r2, -0x3
+jslt32 r1, r2, +0x3
+jsle32 r1, r2, -0x3"
+    );
+
+    disasm!(
+        "jeq32 r1, 0x2, +0x3
+jgt32 r1, 0x2, +0x3
+jge32 r1, 0x2, +0x3
+jlt32 r1, 0x2, +0x3
+jle32 r1, 0x2, +0x3
+jset32 r1, 0x2, +0x3
+jne32 r1, 0x2, +0x3
+jsgt32 r1, 0x2, +0x3
+jsge32 r1, 0x2, -0x3
+jslt32 r1, 0x2, +0x3
+jsle32 r1, 0x2, -0x3"
+    );
+}
+
+// Test all supported Endian mnemonics.
+#[test]
+fn test_endian() {
+    disasm!(
+        "be16 r1
+be32 r1
+be64 r1
+le16 r1
+le32 r1
+le64 r1"
+    );
+}
+
+#[test]
+fn test_large_immediate() {
+    disasm!("add64 r1, 0x7fffffff");
+    disasm!("add64 r1, 0x7fffffff");
+}
+
+// Non-regression tests for overflow when trying to negate offset 0x8000i16.
+#[test]
+fn test_offset_overflow() {
+    let insns = [
+        0x62, 0x01, 0x00, 0x80, 0x01, 0x00, 0x00, 0x00, // stw
+        0x6a, 0x01, 0x00, 0x80, 0x01, 0x00, 0x00, 0x00, // sth
+        0x72, 0x01, 0x00, 0x80, 0x01, 0x00, 0x00, 0x00, // stb
+        0x7a, 0x01, 0x00, 0x80, 0x01, 0x00, 0x00, 0x00, // stdw
+        0x61, 0x01, 0x00, 0x80, 0x00, 0x00, 0x00, 0x00, // ldxw
+        0x69, 0x01, 0x00, 0x80, 0x00, 0x00, 0x00, 0x00, // ldxh
+        0x71, 0x01, 0x00, 0x80, 0x00, 0x00, 0x00, 0x00, // ldxb
+        0x79, 0x01, 0x00, 0x80, 0x00, 0x00, 0x00, 0x00, // ldxdw
+        0x15, 0x01, 0x00, 0x80, 0x02, 0x00, 0x00, 0x00, // jeq (imm)
+        0x1d, 0x21, 0x00, 0x80, 0x00, 0x00, 0x00, 0x00, // jeq (reg)
+        0x16, 0x01, 0x00, 0x80, 0x02, 0x00, 0x00, 0x00, // jeq32 (imm)
+        0x1e, 0x21, 0x00, 0x80, 0x00, 0x00, 0x00, 0x00, // jeq32 (reg)
+    ];
+
+    let expected_output = "stw [r1-0x8000], 0x1
+sth [r1-0x8000], 0x1
+stb [r1-0x8000], 0x1
+stdw [r1-0x8000], 0x1
+ldxw r1, [r0-0x8000]
+ldxh r1, [r0-0x8000]
+ldxb r1, [r0-0x8000]
+ldxdw r1, [r0-0x8000]
+jeq r1, 0x2, -0x8000
+jeq r1, r2, -0x8000
+jeq32 r1, 0x2, -0x8000
+jeq32 r1, r2, -0x8000";
+
+    let prog = to_insn_vec(&insns);
+    let asm = prog
+        .into_iter()
+        .map(|ins| ins.desc)
+        .collect::<Vec<_>>()
+        .join("\n");
+
+    assert_eq!(asm, expected_output);
+}

kernel/crates/rbpf/tests/misc.rs

@@ -0,0 +1,571 @@
+// SPDX-License-Identifier: (Apache-2.0 OR MIT)
+// Copyright 2016 6WIND S.A. <quentin.monnet@6wind.com>
+
+// There are unused mut warnings due to unsafe code.
+#![allow(unused_mut)]
+#![allow(clippy::unreadable_literal)]
+
+// This crate would be needed to load bytecode from a BPF-compiled object file. Since the crate
+// is not used anywhere else in the library, it is deactivated: we do not want to load and compile
+// it just for the tests. If you want to use it, do not forget to add the following
+// dependency to your Cargo.toml file:
+//
+// ---
+// elf = "0.0.10"
+// ---
+//
+// extern crate elf;
+// use std::path::PathBuf;
+
+extern crate rbpf;
+
+#[cfg(feature = "std")]
+use rbpf::helpers;
+use rbpf::{assembler::assemble, Error, ErrorKind};
+
+// The following two examples have been compiled from C with the following command:
+//
+// ```bash
+//  clang -O2 -emit-llvm -c <file.c> -o - | llc -march=bpf -filetype=obj -o <file.o>
+// ```
+//
+// The C source code was the following:
+//
+// ```c
+// #include <linux/ip.h>
+// #include <linux/in.h>
+// #include <linux/tcp.h>
+// #include <linux/bpf.h>
+//
+// #define ETH_ALEN 6
+// #define ETH_P_IP 0x0008 /* htons(0x0800) */
+// #define TCP_HDR_LEN 20
+//
+// #define BLOCKED_TCP_PORT 0x9999
+//
+// struct eth_hdr {
+//     unsigned char   h_dest[ETH_ALEN];
+//     unsigned char   h_source[ETH_ALEN];
+//     unsigned short  h_proto;
+// };
+//
+// #define SEC(NAME) __attribute__((section(NAME), used))
+// SEC(".classifier")
+// int handle_ingress(struct __sk_buff *skb)
+// {
+//     void *data = (void *)(long)skb->data;
+//     void *data_end = (void *)(long)skb->data_end;
+//     struct eth_hdr *eth = data;
+//     struct iphdr *iph = data + sizeof(*eth);
+//     struct tcphdr *tcp = data + sizeof(*eth) + sizeof(*iph);
+//
+//     /* single length check */
+//     if (data + sizeof(*eth) + sizeof(*iph) + sizeof(*tcp) > data_end)
+//         return 0;
+//     if (eth->h_proto != ETH_P_IP)
+//         return 0;
+//     if (iph->protocol != IPPROTO_TCP)
+//         return 0;
+//     if (tcp->source == BLOCKED_TCP_PORT || tcp->dest == BLOCKED_TCP_PORT)
+//         return -1;
+//     return 0;
+// }
+// char _license[] SEC(".license") = "GPL";
+// ```
+//
+// This program, once compiled, can be injected into Linux kernel, with tc for instance. Sadly, we
+// need to bring some modifications to the generated bytecode in order to run it: the three
+// instructions with opcode 0x61 load data from a packet area as 4-byte words, where we need to
+// load it as 8-bytes double words (0x79). The kernel does the same kind of translation before
+// running the program, but rbpf does not implement this.
+//
+// In addition, the offset at which the pointer to the packet data is stored must be changed: since
+// we use 8 bytes instead of 4 for the start and end addresses of the data packet, we cannot use
+// the offsets produced by clang (0x4c and 0x50), the addresses would overlap. Instead we can use,
+// for example, 0x40 and 0x50. See comments on the bytecode below to see the modifications.
+//
+// Once the bytecode has been (manually, in our case) edited, we can load the bytecode directly
+// from the ELF object file. This is easy to do, but requires the addition of two crates in the
+// Cargo.toml file (see comments above), so here we use just the hardcoded bytecode instructions
+// instead.
+
+#[test]
+#[cfg(feature = "std")]
+fn test_vm_block_port() {
+    // To load the bytecode from an object file instead of using the hardcoded instructions,
+    // use the additional crates commented at the beginning of this file (and also add them to your
+    // Cargo.toml). See comments above.
+    //
+    // ---
+    // let filename = "my_ebpf_object_file.o";
+    //
+    // let path = PathBuf::from(filename);
+    // let file = match elf::File::open_path(&path) {
+    //     Ok(f) => f,
+    //     Err(e) => panic!("Error: {:?}", e),
+    // };
+    //
+    // let text_scn = match file.get_section(".classifier") {
+    //     Some(s) => s,
+    //     None => panic!("Failed to look up .classifier section"),
+    // };
+    //
+    // let prog = &text_scn.data;
+    // ---
+
+    let prog = &[
+        0xb7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x79, 0x12, 0x50, 0x00, 0x00, 0x00, 0x00,
+        0x00, // 0x79 instead of 0x61
+        0x79, 0x11, 0x40, 0x00, 0x00, 0x00, 0x00,
+        0x00, // 0x79 instead of 0x61, 0x40 i.o. 0x4c
+        0xbf, 0x13, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x07, 0x03, 0x00, 0x00, 0x36, 0x00, 0x00,
+        0x00, 0x2d, 0x23, 0x12, 0x00, 0x00, 0x00, 0x00, 0x00, 0x69, 0x12, 0x0c, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x55, 0x02, 0x10, 0x00, 0x08, 0x00, 0x00, 0x00, 0x71, 0x12, 0x17, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x55, 0x02, 0x0e, 0x00, 0x06, 0x00, 0x00, 0x00, 0x18, 0x00, 0x00, 0x00,
+        0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x79, 0x11, 0x22,
+        0x00, 0x00, 0x00, 0x00, 0x00, // 0x79 instead of 0x61
+        0xbf, 0x12, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x57, 0x02, 0x00, 0x00, 0xff, 0xff, 0x00,
+        0x00, 0x15, 0x02, 0x08, 0x00, 0x99, 0x99, 0x00, 0x00, 0x18, 0x02, 0x00, 0x00, 0x00, 0x00,
+        0xff, 0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x5f, 0x21, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0xb7, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0x18, 0x02, 0x00, 0x00,
+        0x00, 0x00, 0x99, 0x99, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1d, 0x21, 0x01,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0xb7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x95, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    ];
+
+    let packet = &mut [
+        0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xfe, 0xdc, 0xba, 0x98, 0x76, 0x54, 0x08,
+        0x00, // ethertype
+        0x45, 0x00, 0x00, 0x3b, // start ip_hdr
+        0xa6, 0xab, 0x40, 0x00, 0x40, 0x06, 0x96, 0x0f, 0x7f, 0x00, 0x00, 0x01, 0x7f, 0x00, 0x00,
+        0x01,
+        // Program matches the next two bytes: 0x9999 returns 0xffffffff, else return 0.
+        0x99, 0x99, 0xc6, 0xcc, // start tcp_hdr
+        0xd1, 0xe5, 0xc4, 0x9d, 0xd4, 0x30, 0xb5, 0xd2, 0x80, 0x18, 0x01, 0x56, 0xfe, 0x2f, 0x00,
+        0x00, 0x01, 0x01, 0x08, 0x0a, // start data
+        0x00, 0x23, 0x75, 0x89, 0x00, 0x23, 0x63, 0x2d, 0x71, 0x64, 0x66, 0x73, 0x64, 0x66, 0x0au8,
+    ];
+
+    let mut vm = rbpf::EbpfVmFixedMbuff::new(Some(prog), 0x40, 0x50).unwrap();
+    vm.register_helper(helpers::BPF_TRACE_PRINTK_IDX, helpers::bpf_trace_printf)
+        .unwrap();
+
+    let res = vm.execute_program(packet).unwrap();
+    println!("Program returned: {res:?} ({res:#x})");
+    assert_eq!(res, 0xffffffff);
+}
+
+#[test]
+#[cfg(all(not(windows), feature = "std"))]
+fn test_jit_block_port() {
+    // To load the bytecode from an object file instead of using the hardcoded instructions,
+    // use the additional crates commented at the beginning of this file (and also add them to your
+    // Cargo.toml). See comments above.
+    //
+    // ---
+    // let filename = "my_ebpf_object_file.o";
+    //
+    // let path = PathBuf::from(filename);
+    // let file = match elf::File::open_path(&path) {
+    //     Ok(f) => f,
+    //     Err(e) => panic!("Error: {:?}", e),
+    // };
+    //
+    // let text_scn = match file.get_section(".classifier") {
+    //     Some(s) => s,
+    //     None => panic!("Failed to look up .classifier section"),
+    // };
+    //
+    // let prog = &text_scn.data;
+    // ---
+
+    let prog = &[
+        0xb7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x79, 0x12, 0x50, 0x00, 0x00, 0x00, 0x00,
+        0x00, // 0x79 instead of 0x61
+        0x79, 0x11, 0x40, 0x00, 0x00, 0x00, 0x00,
+        0x00, // 0x79 instead of 0x61, 0x40 i.o. 0x4c
+        0xbf, 0x13, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x07, 0x03, 0x00, 0x00, 0x36, 0x00, 0x00,
+        0x00, 0x2d, 0x23, 0x12, 0x00, 0x00, 0x00, 0x00, 0x00, 0x69, 0x12, 0x0c, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x55, 0x02, 0x10, 0x00, 0x08, 0x00, 0x00, 0x00, 0x71, 0x12, 0x17, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x55, 0x02, 0x0e, 0x00, 0x06, 0x00, 0x00, 0x00, 0x18, 0x00, 0x00, 0x00,
+        0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x79, 0x11, 0x22,
+        0x00, 0x00, 0x00, 0x00, 0x00, // 0x79 instead of 0x61
+        0xbf, 0x12, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x57, 0x02, 0x00, 0x00, 0xff, 0xff, 0x00,
+        0x00, 0x15, 0x02, 0x08, 0x00, 0x99, 0x99, 0x00, 0x00, 0x18, 0x02, 0x00, 0x00, 0x00, 0x00,
+        0xff, 0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x5f, 0x21, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0xb7, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0x18, 0x02, 0x00, 0x00,
+        0x00, 0x00, 0x99, 0x99, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1d, 0x21, 0x01,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0xb7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x95, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    ];
+
+    let packet = &mut [
+        0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xfe, 0xdc, 0xba, 0x98, 0x76, 0x54, 0x08,
+        0x00, // ethertype
+        0x45, 0x00, 0x00, 0x3b, // start ip_hdr
+        0xa6, 0xab, 0x40, 0x00, 0x40, 0x06, 0x96, 0x0f, 0x7f, 0x00, 0x00, 0x01, 0x7f, 0x00, 0x00,
+        0x01,
+        // Program matches the next two bytes: 0x9999 returns 0xffffffff, else return 0.
+        0x99, 0x99, 0xc6, 0xcc, // start tcp_hdr
+        0xd1, 0xe5, 0xc4, 0x9d, 0xd4, 0x30, 0xb5, 0xd2, 0x80, 0x18, 0x01, 0x56, 0xfe, 0x2f, 0x00,
+        0x00, 0x01, 0x01, 0x08, 0x0a, // start data
+        0x00, 0x23, 0x75, 0x89, 0x00, 0x23, 0x63, 0x2d, 0x71, 0x64, 0x66, 0x73, 0x64, 0x66, 0x0au8,
+    ];
+
+    let mut vm = rbpf::EbpfVmFixedMbuff::new(Some(prog), 0x40, 0x50).unwrap();
+    vm.register_helper(helpers::BPF_TRACE_PRINTK_IDX, helpers::bpf_trace_printf)
+        .unwrap();
+    vm.jit_compile().unwrap();
+
+    unsafe {
+        let res = vm.execute_program_jit(packet).unwrap();
+        println!("Program returned: {res:?} ({res:#x})");
+        assert_eq!(res, 0xffffffff);
+    }
+}
+
+// Program and memory come from uBPF test ldxh.
+#[test]
+fn test_vm_mbuff() {
+    let prog = &[
+        // Load mem from mbuff into R1
+        0x79, 0x11, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, // ldhx r1[2], r0
+        0x69, 0x10, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00,
+    ];
+    let mem = &[0xaa, 0xbb, 0x11, 0x22, 0xcc, 0xdd];
+
+    let mbuff = [0u8; 32];
+    unsafe {
+        let mut data = mbuff.as_ptr().offset(8) as *mut u64;
+        let mut data_end = mbuff.as_ptr().offset(24) as *mut u64;
+        data.write_unaligned(mem.as_ptr() as u64);
+        data_end.write_unaligned(mem.as_ptr() as u64 + mem.len() as u64);
+    }
+
+    let vm = rbpf::EbpfVmMbuff::new(Some(prog)).unwrap();
+    assert_eq!(vm.execute_program(mem, &mbuff).unwrap(), 0x2211);
+}
+
+// Program and memory come from uBPF test ldxh.
+#[test]
+fn test_vm_mbuff_with_rust_api() {
+    use rbpf::insn_builder::*;
+
+    let mut program = BpfCode::new();
+    program
+        .load_x(MemSize::DoubleWord)
+        .set_dst(0x01)
+        .set_src(0x01)
+        .set_off(0x00_08)
+        .push()
+        .load_x(MemSize::HalfWord)
+        .set_dst(0x00)
+        .set_src(0x01)
+        .set_off(0x00_02)
+        .push()
+        .exit()
+        .push();
+
+    let mem = &[0xaa, 0xbb, 0x11, 0x22, 0xcc, 0xdd];
+
+    let mbuff = [0u8; 32];
+    unsafe {
+        let mut data = mbuff.as_ptr().offset(8) as *mut u64;
+        let mut data_end = mbuff.as_ptr().offset(24) as *mut u64;
+        *data = mem.as_ptr() as u64;
+        *data_end = mem.as_ptr() as u64 + mem.len() as u64;
+    }
+
+    let vm = rbpf::EbpfVmMbuff::new(Some(program.into_bytes())).unwrap();
+    assert_eq!(vm.execute_program(mem, &mbuff).unwrap(), 0x2211);
+}
+
+// Program and memory come from uBPF test ldxh.
+#[test]
+#[cfg(all(not(windows), feature = "std"))]
+fn test_jit_mbuff() {
+    let prog = &[
+        // Load mem from mbuff into R1
+        0x79, 0x11, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, // ldhx r1[2], r0
+        0x69, 0x10, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00,
+    ];
+    let mem = &mut [0xaa, 0xbb, 0x11, 0x22, 0xcc, 0xdd];
+
+    let mut mbuff = [0u8; 32];
+    unsafe {
+        let mut data = mbuff.as_ptr().offset(8) as *mut u64;
+        let mut data_end = mbuff.as_ptr().offset(24) as *mut u64;
+        *data = mem.as_ptr() as u64;
+        *data_end = mem.as_ptr() as u64 + mem.len() as u64;
+    }
+
+    unsafe {
+        let mut vm = rbpf::EbpfVmMbuff::new(Some(prog)).unwrap();
+        vm.jit_compile().unwrap();
+        assert_eq!(vm.execute_program_jit(mem, &mut mbuff).unwrap(), 0x2211);
+    }
+}
+
+#[cfg(all(not(windows), feature = "std"))]
+#[test]
+fn test_vm_jit_ldabsb() {
+    let prog = &[
+        0x30, 0x00, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00,
+    ];
+    let mem = &mut [
+        0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee,
+        0xff,
+    ];
+    let mut vm = rbpf::EbpfVmRaw::new(Some(prog)).unwrap();
+    assert_eq!(vm.execute_program(mem).unwrap(), 0x33);
+
+    vm.jit_compile().unwrap();
+    unsafe {
+        assert_eq!(vm.execute_program_jit(mem).unwrap(), 0x33);
+    };
+}
+
+#[cfg(all(not(windows), feature = "std"))]
+#[test]
+fn test_vm_jit_ldabsh() {
+    let prog = &[
+        0x28, 0x00, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00,
+    ];
+    let mem = &mut [
+        0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee,
+        0xff,
+    ];
+    let mut vm = rbpf::EbpfVmRaw::new(Some(prog)).unwrap();
+    assert_eq!(vm.execute_program(mem).unwrap(), 0x4433);
+
+    vm.jit_compile().unwrap();
+    unsafe {
+        assert_eq!(vm.execute_program_jit(mem).unwrap(), 0x4433);
+    };
+}
+
+#[cfg(all(not(windows), feature = "std"))]
+#[test]
+fn test_vm_jit_ldabsw() {
+    let prog = &[
+        0x20, 0x00, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00,
+    ];
+    let mem = &mut [
+        0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee,
+        0xff,
+    ];
+    let mut vm = rbpf::EbpfVmRaw::new(Some(prog)).unwrap();
+    assert_eq!(vm.execute_program(mem).unwrap(), 0x66554433);
+    vm.jit_compile().unwrap();
+
+    unsafe {
+        assert_eq!(vm.execute_program_jit(mem).unwrap(), 0x66554433);
+    };
+}
+
+#[cfg(all(not(windows), feature = "std"))]
+#[test]
+fn test_vm_jit_ldabsdw() {
+    let prog = &[
+        0x38, 0x00, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00,
+    ];
+    let mem = &mut [
+        0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee,
+        0xff,
+    ];
+    let mut vm = rbpf::EbpfVmRaw::new(Some(prog)).unwrap();
+    assert_eq!(vm.execute_program(mem).unwrap(), 0xaa99887766554433);
+    vm.jit_compile().unwrap();
+
+    unsafe {
+        assert_eq!(vm.execute_program_jit(mem).unwrap(), 0xaa99887766554433);
+    };
+}
+
+#[test]
+#[should_panic(expected = "Error: out of bounds memory load (insn #1),")]
+fn test_vm_err_ldabsb_oob() {
+    let prog = &[
+        0x38, 0x00, 0x00, 0x00, 0x33, 0x00, 0x00, 0x00, 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00,
+    ];
+    let mem = &mut [
+        0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee,
+        0xff,
+    ];
+    let vm = rbpf::EbpfVmRaw::new(Some(prog)).unwrap();
+    vm.execute_program(mem).unwrap();
+
+    // Memory check not implemented for JIT yet.
+}
+
+#[test]
+#[should_panic(expected = "Error: out of bounds memory load (insn #1),")]
+fn test_vm_err_ldabsb_nomem() {
+    let prog = &[
+        0x38, 0x00, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00,
+    ];
+    let vm = rbpf::EbpfVmNoData::new(Some(prog)).unwrap();
+    vm.execute_program().unwrap();
+
+    // Memory check not implemented for JIT yet.
+}
+
+#[cfg(all(not(windows), feature = "std"))]
+#[test]
+fn test_vm_jit_ldindb() {
+    let prog = &[
+        0xb7, 0x01, 0x00, 0x00, 0x05, 0x00, 0x00, 0x00, 0x50, 0x10, 0x00, 0x00, 0x03, 0x00, 0x00,
+        0x00, 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    ];
+    let mem = &mut [
+        0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee,
+        0xff,
+    ];
+    let mut vm = rbpf::EbpfVmRaw::new(Some(prog)).unwrap();
+    assert_eq!(vm.execute_program(mem).unwrap(), 0x88);
+
+    vm.jit_compile().unwrap();
+    unsafe {
+        assert_eq!(vm.execute_program_jit(mem).unwrap(), 0x88);
+    };
+}
+
+#[cfg(all(not(windows), feature = "std"))]
+#[test]
+fn test_vm_jit_ldindh() {
+    let prog = &[
+        0xb7, 0x01, 0x00, 0x00, 0x05, 0x00, 0x00, 0x00, 0x48, 0x10, 0x00, 0x00, 0x03, 0x00, 0x00,
+        0x00, 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    ];
+    let mem = &mut [
+        0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee,
+        0xff,
+    ];
+    let mut vm = rbpf::EbpfVmRaw::new(Some(prog)).unwrap();
+    assert_eq!(vm.execute_program(mem).unwrap(), 0x9988);
+
+    vm.jit_compile().unwrap();
+    unsafe {
+        assert_eq!(vm.execute_program_jit(mem).unwrap(), 0x9988);
+    };
+}
+
+#[cfg(all(not(windows), feature = "std"))]
+#[test]
+fn test_vm_jit_ldindw() {
+    let prog = &[
+        0xb7, 0x01, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, 0x40, 0x10, 0x00, 0x00, 0x01, 0x00, 0x00,
+        0x00, 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    ];
+    let mem = &mut [
+        0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee,
+        0xff,
+    ];
+    let mut vm = rbpf::EbpfVmRaw::new(Some(prog)).unwrap();
+    assert_eq!(vm.execute_program(mem).unwrap(), 0x88776655);
+    vm.jit_compile().unwrap();
+
+    unsafe {
+        assert_eq!(vm.execute_program_jit(mem).unwrap(), 0x88776655);
+    };
+}
+
+#[cfg(all(not(windows), feature = "std"))]
+#[test]
+fn test_vm_jit_ldinddw() {
+    let prog = &[
+        0xb7, 0x01, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x58, 0x10, 0x00, 0x00, 0x03, 0x00, 0x00,
+        0x00, 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    ];
+    let mem = &mut [
+        0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee,
+        0xff,
+    ];
+    let mut vm = rbpf::EbpfVmRaw::new(Some(prog)).unwrap();
+    assert_eq!(vm.execute_program(mem).unwrap(), 0xccbbaa9988776655);
+    vm.jit_compile().unwrap();
+
+    unsafe {
+        assert_eq!(vm.execute_program_jit(mem).unwrap(), 0xccbbaa9988776655);
+    };
+}
+
+#[test]
+#[should_panic(expected = "Error: out of bounds memory load (insn #2),")]
+fn test_vm_err_ldindb_oob() {
+    let prog = &[
+        0xb7, 0x01, 0x00, 0x00, 0x05, 0x00, 0x00, 0x00, 0x38, 0x10, 0x00, 0x00, 0x33, 0x00, 0x00,
+        0x00, 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    ];
+    let mem = &mut [
+        0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee,
+        0xff,
+    ];
+    let vm = rbpf::EbpfVmRaw::new(Some(prog)).unwrap();
+    vm.execute_program(mem).unwrap();
+
+    // Memory check not implemented for JIT yet.
+}
+
+#[test]
+#[should_panic(expected = "Error: out of bounds memory load (insn #2),")]
+fn test_vm_err_ldindb_nomem() {
+    let prog = &[
+        0xb7, 0x01, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0x38, 0x10, 0x00, 0x00, 0x03, 0x00, 0x00,
+        0x00, 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    ];
+    let vm = rbpf::EbpfVmNoData::new(Some(prog)).unwrap();
+    vm.execute_program().unwrap();
+
+    // Memory check not implemented for JIT yet.
+}
+
+#[test]
+#[should_panic(expected = "Error: No program set, call prog_set() to load one")]
+fn test_vm_exec_no_program() {
+    let vm = rbpf::EbpfVmNoData::new(None).unwrap();
+    assert_eq!(vm.execute_program().unwrap(), 0xBEE);
+}
+
+fn verifier_success(_prog: &[u8]) -> Result<(), Error> {
+    Ok(())
+}
+
+fn verifier_fail(_prog: &[u8]) -> Result<(), Error> {
+    Err(Error::new(ErrorKind::Other, "Gaggablaghblagh!"))
+}
+
+#[test]
+fn test_verifier_success() {
+    let prog = assemble(
+        "mov32 r0, 0xBEE
+         exit",
+    )
+    .unwrap();
+    let mut vm = rbpf::EbpfVmNoData::new(None).unwrap();
+    vm.set_verifier(verifier_success).unwrap();
+    vm.set_program(&prog).unwrap();
+    assert_eq!(vm.execute_program().unwrap(), 0xBEE);
+}
+
+#[test]
+#[should_panic(expected = "Gaggablaghblagh!")]
+fn test_verifier_fail() {
+    let prog = assemble(
+        "mov32 r0, 0xBEE
+         exit",
+    )
+    .unwrap();
+    let mut vm = rbpf::EbpfVmNoData::new(None).unwrap();
+    vm.set_verifier(verifier_fail).unwrap();
+    vm.set_program(&prog).unwrap();
+    assert_eq!(vm.execute_program().unwrap(), 0xBEE);
+}

kernel/crates/rbpf/tests/ubpf_verifier.rs

@@ -0,0 +1,177 @@
+// SPDX-License-Identifier: (Apache-2.0 OR MIT)
+// Converted from the tests for uBPF <https://github.com/iovisor/ubpf>
+// Copyright 2015 Big Switch Networks, Inc
+// Copyright 2016 6WIND S.A. <quentin.monnet@6wind.com>
+
+// The tests contained in this file are extracted from the unit tests of uBPF software. Each test
+// in this file has a name in the form `test_verifier_<name>`, and corresponds to the
+// (human-readable) code in `ubpf/tree/master/tests/<name>`, available at
+// <https://github.com/iovisor/ubpf/tree/master/tests> (hyphen had to be replaced with underscores
+// as Rust will not accept them in function names). It is strongly advised to refer to the uBPF
+// version to understand what these program do.
+//
+// Each program was assembled from the uBPF version with the assembler provided by uBPF itself, and
+// available at <https://github.com/iovisor/ubpf/tree/master/ubpf>.
+// The very few modifications that have been realized should be indicated.
+
+// These are unit tests for the eBPF “verifier”.
+
+extern crate rbpf;
+
+use rbpf::{assembler::assemble, ebpf};
+
+#[test]
+#[should_panic(expected = "[Verifier] Error: unsupported argument for LE/BE (insn #0)")]
+fn test_verifier_err_endian_size() {
+    let prog = &[
+        0xdc, 0x01, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0xb7, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    ];
+    let vm = rbpf::EbpfVmNoData::new(Some(prog)).unwrap();
+    vm.execute_program().unwrap();
+}
+
+#[test]
+#[should_panic(expected = "[Verifier] Error: incomplete LD_DW instruction (insn #0)")]
+fn test_verifier_err_incomplete_lddw() {
+    // Note: ubpf has test-err-incomplete-lddw2, which is the same
+    let prog = &[
+        0x18, 0x00, 0x00, 0x00, 0x88, 0x77, 0x66, 0x55, 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00,
+    ];
+    let vm = rbpf::EbpfVmNoData::new(Some(prog)).unwrap();
+    vm.execute_program().unwrap();
+}
+
+#[test]
+#[should_panic(expected = "[Verifier] Error: infinite loop")]
+fn test_verifier_err_infinite_loop() {
+    let prog = assemble(
+        "
+        ja -1
+        exit",
+    )
+    .unwrap();
+    let vm = rbpf::EbpfVmNoData::new(Some(&prog)).unwrap();
+    vm.execute_program().unwrap();
+}
+
+#[test]
+#[should_panic(expected = "[Verifier] Error: invalid destination register (insn #0)")]
+fn test_verifier_err_invalid_reg_dst() {
+    let prog = assemble(
+        "
+        mov r11, 1
+        exit",
+    )
+    .unwrap();
+    let vm = rbpf::EbpfVmNoData::new(Some(&prog)).unwrap();
+    vm.execute_program().unwrap();
+}
+
+#[test]
+#[should_panic(expected = "[Verifier] Error: invalid source register (insn #0)")]
+fn test_verifier_err_invalid_reg_src() {
+    let prog = assemble(
+        "
+        mov r0, r11
+        exit",
+    )
+    .unwrap();
+    let vm = rbpf::EbpfVmNoData::new(Some(&prog)).unwrap();
+    vm.execute_program().unwrap();
+}
+
+#[test]
+#[should_panic(expected = "[Verifier] Error: jump to middle of LD_DW at #2 (insn #0)")]
+fn test_verifier_err_jmp_lddw() {
+    let prog = assemble(
+        "
+        ja +1
+        lddw r0, 0x1122334455667788
+        exit",
+    )
+    .unwrap();
+    let vm = rbpf::EbpfVmNoData::new(Some(&prog)).unwrap();
+    vm.execute_program().unwrap();
+}
+
+#[test]
+#[should_panic(expected = "[Verifier] Error: jump out of code to #3 (insn #0)")]
+fn test_verifier_err_jmp_out() {
+    let prog = assemble(
+        "
+        ja +2
+        exit",
+    )
+    .unwrap();
+    let vm = rbpf::EbpfVmNoData::new(Some(&prog)).unwrap();
+    vm.execute_program().unwrap();
+}
+
+#[test]
+#[should_panic(expected = "[Verifier] Error: program does not end with “EXIT” instruction")]
+fn test_verifier_err_no_exit() {
+    let prog = assemble(
+        "
+        mov32 r0, 0",
+    )
+    .unwrap();
+    let vm = rbpf::EbpfVmNoData::new(Some(&prog)).unwrap();
+    vm.execute_program().unwrap();
+}
+
+#[test]
+fn test_verifier_err_no_exit_backward_jump() {
+    let prog = assemble(
+        "
+        ja +1
+        exit
+        ja -2",
+    )
+    .unwrap();
+    let vm = rbpf::EbpfVmNoData::new(Some(&prog)).unwrap();
+    vm.execute_program().unwrap();
+}
+
+#[test]
+#[should_panic(expected = "[Verifier] Error: eBPF program length limited to 1000000, here 1000001")]
+fn test_verifier_err_too_many_instructions() {
+    // uBPF uses 65637 instructions, because it sets its limit at 65636.
+    // We use the classic 4096 limit from kernel, so no need to produce as many instructions.
+    let mut prog = (0..(1_000_000 * ebpf::INSN_SIZE))
+        .map(|x| match x % 8 {
+            0 => 0xb7,
+            1 => 0x01,
+            _ => 0,
+        })
+        .collect::<Vec<u8>>();
+    prog.append(&mut vec![0x95, 0, 0, 0, 0, 0, 0, 0]);
+
+    let vm = rbpf::EbpfVmNoData::new(Some(&prog)).unwrap();
+    vm.execute_program().unwrap();
+}
+
+#[test]
+#[should_panic(expected = "[Verifier] Error: unknown eBPF opcode 0x6 (insn #0)")]
+fn test_verifier_err_unknown_opcode() {
+    let prog = &[
+        0x06, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x95, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00,
+    ];
+    let vm = rbpf::EbpfVmNoData::new(Some(prog)).unwrap();
+    vm.execute_program().unwrap();
+}
+
+#[test]
+#[should_panic(expected = "[Verifier] Error: cannot write into register r10 (insn #0)")]
+fn test_verifier_err_write_r10() {
+    let prog = assemble(
+        "
+        mov r10, 1
+        exit",
+    )
+    .unwrap();
+    let vm = rbpf::EbpfVmNoData::new(Some(&prog)).unwrap();
+    vm.execute_program().unwrap();
+}