rustix/backend/linux_raw/net/
netdevice.rs

1//! Wrappers for netdevice ioctls.
2
3#![allow(unsafe_code)]
4
5use crate::backend::io::syscalls::ioctl;
6use crate::fd::BorrowedFd;
7use crate::io;
8use core::ptr::addr_of_mut;
9use core::{slice, str};
10use linux_raw_sys::ctypes::c_char;
11use linux_raw_sys::ioctl::{SIOCGIFINDEX, SIOCGIFNAME};
12use linux_raw_sys::net::{ifreq, ifreq__bindgen_ty_1, ifreq__bindgen_ty_2, IFNAMSIZ};
13
14pub(crate) fn name_to_index(fd: BorrowedFd<'_>, if_name: &str) -> io::Result<u32> {
15    let if_name_bytes = if_name.as_bytes();
16    if if_name_bytes.len() >= IFNAMSIZ as usize {
17        return Err(io::Errno::NODEV);
18    }
19    if if_name_bytes.contains(&0) {
20        return Err(io::Errno::NODEV);
21    }
22
23    // SAFETY: Convert `&[u8]` to `&[c_char]`.
24    let if_name_bytes = unsafe {
25        slice::from_raw_parts(if_name_bytes.as_ptr().cast::<c_char>(), if_name_bytes.len())
26    };
27
28    let mut ifreq = ifreq {
29        ifr_ifrn: ifreq__bindgen_ty_1 { ifrn_name: [0; 16] },
30        ifr_ifru: ifreq__bindgen_ty_2 { ifru_ivalue: 0 },
31    };
32    unsafe { ifreq.ifr_ifrn.ifrn_name[..if_name_bytes.len()].copy_from_slice(if_name_bytes) };
33
34    unsafe { ioctl(fd, SIOCGIFINDEX, addr_of_mut!(ifreq).cast()) }?;
35    let index = unsafe { ifreq.ifr_ifru.ifru_ivalue };
36    Ok(index as u32)
37}
38
39pub(crate) fn index_to_name(fd: BorrowedFd<'_>, index: u32) -> io::Result<(usize, [u8; 16])> {
40    let mut ifreq = ifreq {
41        ifr_ifrn: ifreq__bindgen_ty_1 { ifrn_name: [0; 16] },
42        ifr_ifru: ifreq__bindgen_ty_2 {
43            ifru_ivalue: index as _,
44        },
45    };
46
47    unsafe { ioctl(fd, SIOCGIFNAME, addr_of_mut!(ifreq).cast()) }?;
48
49    if let Some(nul_byte) = unsafe { ifreq.ifr_ifrn.ifrn_name }
50        .iter()
51        .position(|ch| *ch == 0)
52    {
53        let ifrn_name = unsafe { &ifreq.ifr_ifrn.ifrn_name[..nul_byte] };
54
55        // SAFETY: Convert `&[c_char]` to `&[u8]`.
56        let ifrn_name =
57            unsafe { slice::from_raw_parts(ifrn_name.as_ptr().cast::<u8>(), ifrn_name.len()) };
58
59        let mut name_buf = [0; 16];
60        name_buf[..ifrn_name.len()].copy_from_slice(ifrn_name);
61
62        Ok((nul_byte, name_buf))
63    } else {
64        Err(io::Errno::INVAL)
65    }
66}
rustix/backend/linux_raw/net/netdevice.rs

rustix/backend/linux_raw/net/
netdevice.rs
