79 lines
2.4 KiB
Rust
79 lines
2.4 KiB
Rust
use std::io;
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use std::os::unix::io::{RawFd, AsRawFd};
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use libc;
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use super::*;
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use crate::wire::EthernetFrame;
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#[derive(Debug)]
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pub struct TapInterfaceDesc {
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lower: libc::c_int,
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ifreq: ifreq
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}
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impl AsRawFd for TapInterfaceDesc {
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fn as_raw_fd(&self) -> RawFd {
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self.lower
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}
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}
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impl TapInterfaceDesc {
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pub fn new(name: &str) -> io::Result<TapInterfaceDesc> {
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let lower = unsafe {
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let lower = libc::open("/dev/net/tun\0".as_ptr() as *const libc::c_char,
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libc::O_RDWR | libc::O_NONBLOCK);
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if lower == -1 { return Err(io::Error::last_os_error()) }
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lower
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};
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Ok(TapInterfaceDesc {
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lower: lower,
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ifreq: ifreq_for(name)
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})
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}
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pub fn attach_interface(&mut self) -> io::Result<()> {
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self.ifreq.ifr_data = imp::IFF_TAP | imp::IFF_NO_PI;
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ifreq_ioctl(self.lower, &mut self.ifreq, imp::TUNSETIFF).map(|_| ())
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}
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pub fn interface_mtu(&mut self) -> io::Result<usize> {
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let lower = unsafe {
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let lower = libc::socket(libc::AF_INET, libc::SOCK_DGRAM, libc::IPPROTO_IP);
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if lower == -1 { return Err(io::Error::last_os_error()) }
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lower
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};
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let ip_mtu = ifreq_ioctl(lower, &mut self.ifreq, imp::SIOCGIFMTU).map(|mtu| mtu as usize);
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unsafe { libc::close(lower); }
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// SIOCGIFMTU returns the IP MTU (typically 1500 bytes.)
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// smoltcp counts the entire Ethernet packet in the MTU, so add the Ethernet header size to it.
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Ok(ip_mtu? + EthernetFrame::<&[u8]>::header_len())
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}
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pub fn recv(&mut self, buffer: &mut [u8]) -> io::Result<usize> {
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unsafe {
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let len = libc::read(self.lower, buffer.as_mut_ptr() as *mut libc::c_void,
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buffer.len());
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if len == -1 { return Err(io::Error::last_os_error()) }
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Ok(len as usize)
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}
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}
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pub fn send(&mut self, buffer: &[u8]) -> io::Result<usize> {
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unsafe {
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let len = libc::write(self.lower, buffer.as_ptr() as *const libc::c_void,
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buffer.len());
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if len == -1 { Err(io::Error::last_os_error()).unwrap() }
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Ok(len as usize)
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}
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}
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}
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impl Drop for TapInterfaceDesc {
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fn drop(&mut self) {
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unsafe { libc::close(self.lower); }
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}
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}
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