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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use std::{
io::{Error, Read, Result, Write},
num::TryFromIntError,
os::fd::{AsRawFd, FromRawFd as _, OwnedFd},
sync::atomic::Ordering,
};
use libc::{fsync, read, socket, write, SOCK_RAW};
use crate::unlikely_err;
#[cfg(any(target_os = "linux", target_os = "android"))]
type AtomicRouteSocketSeq = std::sync::atomic::AtomicU32;
#[cfg(any(target_os = "linux", target_os = "android"))]
type RouteSocketSeq = u32;
#[cfg(not(any(target_os = "linux", target_os = "android")))]
type AtomicRouteSocketSeq = std::sync::atomic::AtomicI32;
#[cfg(not(any(target_os = "linux", target_os = "android")))]
type RouteSocketSeq = i32;
static SEQ: AtomicRouteSocketSeq = AtomicRouteSocketSeq::new(0);
pub struct RouteSocket(OwnedFd);
impl RouteSocket {
pub fn new(domain: libc::c_int, protocol: libc::c_int) -> Result<Self> {
let fd = unsafe { socket(domain, SOCK_RAW, protocol) };
if fd == -1 {
return Err(Error::last_os_error());
}
Ok(Self(unsafe { OwnedFd::from_raw_fd(fd) }))
}
pub fn new_seq() -> RouteSocketSeq {
SEQ.fetch_add(1, Ordering::Relaxed)
}
}
impl AsRawFd for RouteSocket {
fn as_raw_fd(&self) -> i32 {
self.0.as_raw_fd()
}
}
fn check_result(res: isize) -> Result<usize> {
if res == -1 {
Err(Error::last_os_error())
} else {
Ok(res
.try_into()
.map_err(|e: TryFromIntError| unlikely_err(e.to_string()))?)
}
}
impl Write for RouteSocket {
fn write(&mut self, buf: &[u8]) -> Result<usize> {
let res = unsafe { write(self.as_raw_fd(), buf.as_ptr().cast(), buf.len()) };
check_result(res)
}
fn flush(&mut self) -> Result<()> {
let res = unsafe { fsync(self.as_raw_fd()) };
check_result(res as isize).and(Ok(()))
}
}
impl Read for RouteSocket {
fn read(&mut self, buf: &mut [u8]) -> Result<usize> {
// If we've written a well-formed message into the kernel via `write`, we should be able to
// read a well-formed message back out, and not block.
let res = unsafe { read(self.as_raw_fd(), buf.as_mut_ptr().cast(), buf.len()) };
check_result(res)
}
}