Add itimer-related syscalls

kernel/aster-nix/src/syscall/timer_settime.rs

@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: MPL-2.0
+
+use core::time::Duration;
+
+use super::SyscallReturn;
+use crate::{
+    prelude::*,
+    time::{itimerspec_t, timer::Timeout, timespec_t, TIMER_ABSTIME},
+    util::{read_val_from_user, write_val_to_user},
+};
+
+pub fn sys_timer_settime(
+    timer_id: usize,
+    flags: i32,
+    new_itimerspec_addr: Vaddr,
+    old_itimerspec_addr: Vaddr,
+) -> Result<SyscallReturn> {
+    if new_itimerspec_addr == 0 {
+        return_errno_with_message!(Errno::EINVAL, "invalid pointer to new value");
+    }
+
+    let new_itimerspec = read_val_from_user::<itimerspec_t>(new_itimerspec_addr)?;
+    let interval = Duration::from(new_itimerspec.it_interval);
+    let expire_time = Duration::from(new_itimerspec.it_value);
+
+    let current_process = current!();
+    let Some(timer) = current_process.timer_manager().find_posix_timer(timer_id) else {
+        return_errno_with_message!(Errno::EINVAL, "invalid timer ID");
+    };
+
+    if old_itimerspec_addr > 0 {
+        let old_interval = timespec_t::from(timer.interval());
+        let remain = timespec_t::from(timer.remain());
+        let old_itimerspec = itimerspec_t {
+            it_interval: old_interval,
+            it_value: remain,
+        };
+        write_val_to_user(old_itimerspec_addr, &old_itimerspec)?;
+    }
+
+    timer.set_interval(interval);
+    if expire_time == Duration::ZERO {
+        // Clear previous timer
+        timer.cancel();
+    } else {
+        let timeout = if flags == 0 {
+            Timeout::After(expire_time)
+        } else if flags == TIMER_ABSTIME {
+            Timeout::When(expire_time)
+        } else {
+            unreachable!()
+        };
+        timer.set_timeout(timeout);
+    }
+
+    Ok(SyscallReturn::Return(0))
+}
+
+pub fn sys_timer_gettime(timer_id: usize, itimerspec_addr: Vaddr) -> Result<SyscallReturn> {
+    if itimerspec_addr == 0 {
+        return_errno_with_message!(Errno::EINVAL, "invalid pointer to return value");
+    }
+    let current_process = current!();
+    let Some(timer) = current_process.timer_manager().find_posix_timer(timer_id) else {
+        return_errno_with_message!(Errno::EINVAL, "invalid timer ID");
+    };
+
+    let interval = timespec_t::from(timer.interval());
+    let remain = timespec_t::from(timer.remain());
+    let itimerspec = itimerspec_t {
+        it_interval: interval,
+        it_value: remain,
+    };
+    write_val_to_user(itimerspec_addr, &itimerspec)?;
+
+    Ok(SyscallReturn::Return(0))
+}