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::AsFd;
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;
12#[cfg(feature = "alloc")]
13use linux_raw_sys::ioctl::SIOCGIFNAME;
14use linux_raw_sys::net::{ifreq, ifreq__bindgen_ty_1, ifreq__bindgen_ty_2, IFNAMSIZ};
15#[cfg(feature = "alloc")]
16use {alloc::borrow::ToOwned, alloc::string::String};
17
18pub(crate) fn name_to_index(fd: impl AsFd, if_name: &str) -> io::Result<u32> {
19    let if_name_bytes = if_name.as_bytes();
20    if if_name_bytes.len() >= IFNAMSIZ as usize {
21        return Err(io::Errno::NODEV);
22    }
23    if if_name_bytes.contains(&0) {
24        return Err(io::Errno::NODEV);
25    }
26
27    // SAFETY: Convert `&[u8]` to `&[c_char]`.
28    let if_name_bytes = unsafe {
29        slice::from_raw_parts(if_name_bytes.as_ptr().cast::<c_char>(), if_name_bytes.len())
30    };
31
32    let mut ifreq = ifreq {
33        ifr_ifrn: ifreq__bindgen_ty_1 { ifrn_name: [0; 16] },
34        ifr_ifru: ifreq__bindgen_ty_2 { ifru_ivalue: 0 },
35    };
36    unsafe { ifreq.ifr_ifrn.ifrn_name[..if_name_bytes.len()].copy_from_slice(if_name_bytes) };
37
38    unsafe { ioctl(fd.as_fd(), SIOCGIFINDEX, addr_of_mut!(ifreq).cast()) }?;
39    let index = unsafe { ifreq.ifr_ifru.ifru_ivalue };
40    Ok(index as u32)
41}
42
43#[cfg(feature = "alloc")]
44pub(crate) fn index_to_name(fd: impl AsFd, index: u32) -> io::Result<String> {
45    let mut ifreq = ifreq {
46        ifr_ifrn: ifreq__bindgen_ty_1 { ifrn_name: [0; 16] },
47        ifr_ifru: ifreq__bindgen_ty_2 {
48            ifru_ivalue: index as _,
49        },
50    };
51
52    unsafe { ioctl(fd.as_fd(), SIOCGIFNAME, addr_of_mut!(ifreq).cast()) }?;
53
54    if let Some(nul_byte) = unsafe { ifreq.ifr_ifrn.ifrn_name }
55        .iter()
56        .position(|ch| *ch == 0)
57    {
58        let ifrn_name = unsafe { &ifreq.ifr_ifrn.ifrn_name[..nul_byte] };
59
60        // SAFETY: Convert `&[c_char]` to `&[u8]`.
61        let ifrn_name =
62            unsafe { slice::from_raw_parts(ifrn_name.as_ptr().cast::<u8>(), ifrn_name.len()) };
63
64        str::from_utf8(ifrn_name)
65            .map_err(|_| io::Errno::ILSEQ)
66            .map(ToOwned::to_owned)
67    } else {
68        Err(io::Errno::INVAL)
69    }
70}
rustix/backend/linux_raw/net/netdevice.rs

rustix/backend/linux_raw/net/
netdevice.rs
