1 #![allow(unsafe_code)]
2
3 use crate::backend::io::syscalls::ioctl;
4 use crate::fd::AsFd;
5 use crate::io;
6 use core::slice;
7 use core::str;
8 use linux_raw_sys::ctypes::c_char;
9 use linux_raw_sys::ioctl::SIOCGIFINDEX;
10 #[cfg(feature = "alloc")]
11 use linux_raw_sys::ioctl::SIOCGIFNAME;
12 use linux_raw_sys::net::{ifreq, ifreq__bindgen_ty_1, ifreq__bindgen_ty_2, IFNAMSIZ};
13 #[cfg(feature = "alloc")]
14 use {alloc::borrow::ToOwned, alloc::string::String};
15
name_to_index(fd: impl AsFd, if_name: &str) -> io::Result<u32>16 pub(crate) fn name_to_index(fd: impl AsFd, if_name: &str) -> io::Result<u32> {
17 let if_name_bytes = if_name.as_bytes();
18 if if_name_bytes.len() >= IFNAMSIZ as usize {
19 return Err(io::Errno::NODEV);
20 }
21 if if_name_bytes.contains(&0) {
22 return Err(io::Errno::NODEV);
23 }
24
25 // SAFETY: Convert `&[u8]` to `&[c_char]`.
26 let if_name_bytes = unsafe {
27 slice::from_raw_parts(if_name_bytes.as_ptr().cast::<c_char>(), if_name_bytes.len())
28 };
29
30 let mut ifreq = ifreq {
31 ifr_ifrn: ifreq__bindgen_ty_1 { ifrn_name: [0; 16] },
32 ifr_ifru: ifreq__bindgen_ty_2 { ifru_ivalue: 0 },
33 };
34 unsafe { ifreq.ifr_ifrn.ifrn_name[..if_name_bytes.len()].copy_from_slice(if_name_bytes) };
35
36 unsafe { ioctl(fd.as_fd(), SIOCGIFINDEX, &mut ifreq as *mut ifreq as _) }?;
37 let index = unsafe { ifreq.ifr_ifru.ifru_ivalue };
38 Ok(index as u32)
39 }
40
41 #[cfg(feature = "alloc")]
index_to_name(fd: impl AsFd, index: u32) -> io::Result<String>42 pub(crate) fn index_to_name(fd: impl AsFd, index: u32) -> io::Result<String> {
43 let mut ifreq = ifreq {
44 ifr_ifrn: ifreq__bindgen_ty_1 { ifrn_name: [0; 16] },
45 ifr_ifru: ifreq__bindgen_ty_2 {
46 ifru_ivalue: index as _,
47 },
48 };
49
50 unsafe { ioctl(fd.as_fd(), SIOCGIFNAME, &mut ifreq as *mut ifreq as _) }?;
51
52 if let Some(nul_byte) = unsafe { ifreq.ifr_ifrn.ifrn_name }
53 .iter()
54 .position(|ch| *ch == 0)
55 {
56 let ifrn_name = unsafe { &ifreq.ifr_ifrn.ifrn_name[..nul_byte] };
57
58 // SAFETY: Convert `&[c_char]` to `&[u8]`.
59 let ifrn_name =
60 unsafe { slice::from_raw_parts(ifrn_name.as_ptr().cast::<u8>(), ifrn_name.len()) };
61
62 str::from_utf8(ifrn_name)
63 .map_err(|_| io::Errno::ILSEQ)
64 .map(ToOwned::to_owned)
65 } else {
66 Err(io::Errno::INVAL)
67 }
68 }
69