Parse netlink message

kernel/src/net/socket/netlink/message/segment/ack.rs

@@ -0,0 +1,90 @@
+// SPDX-License-Identifier: MPL-2.0
+
+//! This module defines segments that only appear in acknowledgment messages.
+//!
+//! An acknowledgment segment appears as the final segment in a response message from the kernel.
+//! Netlink utilizes two classes of acknowledgment segments:
+//! 1. Done Segment: Indicates the conclusion of a message comprised of multiple segments.
+//! 2. Error Segment: Indicates that an error occurred while the kernel processed the user space request.
+//!
+
+use super::{
+    common::SegmentCommon,
+    header::{CMsgSegHdr, SegHdrCommonFlags},
+    CSegmentType, SegmentBody,
+};
+use crate::{net::socket::netlink::message::NoAttr, prelude::*};
+
+pub type DoneSegment = SegmentCommon<DoneSegmentBody, NoAttr>;
+
+#[repr(C)]
+#[derive(Debug, Clone, Copy, Pod)]
+pub struct DoneSegmentBody {
+    error_code: i32,
+}
+
+impl SegmentBody for DoneSegmentBody {
+    type CType = DoneSegmentBody;
+}
+
+impl DoneSegment {
+    pub fn new_from_request(request_header: &CMsgSegHdr, error: Option<Error>) -> Self {
+        let header = CMsgSegHdr {
+            len: 0,
+            type_: CSegmentType::DONE as _,
+            flags: SegHdrCommonFlags::empty().bits(),
+            seq: request_header.seq,
+            pid: request_header.pid,
+        };
+
+        let body = {
+            let error_code = error_to_error_code(error);
+            DoneSegmentBody { error_code }
+        };
+
+        Self::new(header, body, Vec::new())
+    }
+}
+
+pub type ErrorSegment = SegmentCommon<ErrorSegmentBody, NoAttr>;
+
+#[derive(Debug, Pod, Clone, Copy)]
+#[repr(C)]
+pub struct ErrorSegmentBody {
+    error_code: i32,
+    request_header: CMsgSegHdr,
+}
+
+impl SegmentBody for ErrorSegmentBody {
+    type CType = ErrorSegmentBody;
+}
+
+impl ErrorSegment {
+    pub fn new_from_request(request_header: &CMsgSegHdr, error: Option<Error>) -> Self {
+        let header = CMsgSegHdr {
+            len: 0,
+            type_: CSegmentType::ERROR as _,
+            flags: SegHdrCommonFlags::empty().bits(),
+            seq: request_header.seq,
+            pid: request_header.pid,
+        };
+
+        let body = {
+            let error_code = error_to_error_code(error);
+            ErrorSegmentBody {
+                error_code,
+                request_header: *request_header,
+            }
+        };
+
+        Self::new(header, body, Vec::new())
+    }
+}
+
+const fn error_to_error_code(error: Option<Error>) -> i32 {
+    if let Some(error) = error {
+        -(error.error() as i32)
+    } else {
+        0
+    }
+}