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authorMathias Hall-Andersen <mathias@hall-andersen.dk>2019-11-27 22:39:52 +0100
committerMathias Hall-Andersen <mathias@hall-andersen.dk>2019-11-27 22:39:52 +0100
commit68b04e8074a703e61a30d4ef0bbc638109f107a8 (patch)
treefd75f43851d9b57823cc55d980af25d32ae86651 /src/platform/linux/tun.rs
parentWork on netlink IF event code for Linux (diff)
downloadwireguard-rs-68b04e8074a703e61a30d4ef0bbc638109f107a8.tar.xz
wireguard-rs-68b04e8074a703e61a30d4ef0bbc638109f107a8.zip
Fetch updated MTU on linux
Diffstat (limited to '')
-rw-r--r--src/platform/linux/tun.rs95
1 files changed, 75 insertions, 20 deletions
diff --git a/src/platform/linux/tun.rs b/src/platform/linux/tun.rs
index 442d9bc..d9bda07 100644
--- a/src/platform/linux/tun.rs
+++ b/src/platform/linux/tun.rs
@@ -55,6 +55,8 @@ pub struct LinuxTunWriter {
pub struct LinuxTunStatus {
events: Vec<TunEvent>,
+ index: i32,
+ name: [u8; libc::IFNAMSIZ],
fd: RawFd,
}
@@ -63,6 +65,8 @@ pub enum LinuxTunError {
InvalidTunDeviceName,
FailedToOpenCloneDevice,
SetIFFIoctlFailed,
+ GetMTUIoctlFailed,
+ NetlinkFailure,
Closed, // TODO
}
@@ -77,6 +81,8 @@ impl fmt::Display for LinuxTunError {
write!(f, "set_iff ioctl failed (insufficient permissions?)")
}
LinuxTunError::Closed => write!(f, "The tunnel has been closed"),
+ LinuxTunError::GetMTUIoctlFailed => write!(f, "ifmtu ioctl failed"),
+ LinuxTunError::NetlinkFailure => write!(f, "Netlink listener error"),
}
}
}
@@ -123,6 +129,45 @@ impl Writer for LinuxTunWriter {
}
}
+fn get_ifindex(name: &[u8; libc::IFNAMSIZ]) -> i32 {
+ let name = *name;
+ let idx = unsafe {
+ let ptr: *const libc::c_char = mem::transmute(&name);
+ libc::if_nametoindex(ptr)
+ };
+ idx as i32
+}
+
+fn get_mtu(name: &[u8; libc::IFNAMSIZ]) -> Result<usize, LinuxTunError> {
+ #[repr(C)]
+ struct arg {
+ name: [u8; libc::IFNAMSIZ],
+ mtu: u32,
+ }
+
+ // create socket
+ let fd = unsafe { libc::socket(libc::AF_INET, libc::SOCK_DGRAM, 0) };
+ if fd < 0 {
+ return Err(LinuxTunError::GetMTUIoctlFailed);
+ }
+
+ // do SIOCGIFMTU ioctl
+ let buf = arg {
+ name: *name,
+ mtu: 0,
+ };
+ let err = unsafe {
+ let ptr: &libc::c_void = mem::transmute(&buf);
+ libc::ioctl(fd, libc::SIOCGIFMTU, ptr)
+ };
+ if err != 0 {
+ return Err(LinuxTunError::GetMTUIoctlFailed);
+ }
+
+ // upcast to usize
+ Ok(buf.mtu as usize)
+}
+
impl Status for LinuxTunStatus {
type Error = LinuxTunError;
@@ -144,7 +189,7 @@ impl Status for LinuxTunStatus {
let size: libc::ssize_t =
unsafe { libc::recv(self.fd, mem::transmute(&mut buf), buf.len(), 0) };
if size < 0 {
- break Err(LinuxTunError::Closed);
+ break Err(LinuxTunError::NetlinkFailure);
}
// cut buffer to size
@@ -156,9 +201,11 @@ impl Status for LinuxTunStatus {
while remain.len() >= HDR_SIZE {
// extract the header
assert!(remain.len() > HDR_SIZE);
- let mut hdr = [0u8; HDR_SIZE];
- hdr.copy_from_slice(&remain[..HDR_SIZE]);
- let hdr: libc::nlmsghdr = unsafe { mem::transmute(hdr) };
+ let hdr: libc::nlmsghdr = unsafe {
+ let mut hdr = [0u8; HDR_SIZE];
+ hdr.copy_from_slice(&remain[..HDR_SIZE]);
+ mem::transmute(hdr)
+ };
// upcast length
let body: &[u8] = &remain[HDR_SIZE..];
@@ -172,13 +219,13 @@ impl Status for LinuxTunStatus {
libc::RTM_NEWLINK => {
// extract info struct
if body.len() < INFO_SIZE {
- return Err(LinuxTunError::Closed);
+ return Err(LinuxTunError::NetlinkFailure);
}
-
- let mut info = [0u8; INFO_SIZE];
- info.copy_from_slice(&body[..INFO_SIZE]);
- log::debug!("netlink, RTM_NEWLINK {:?}", &info[..]);
- let info: IfInfomsg = unsafe { mem::transmute(info) };
+ let info: IfInfomsg = unsafe {
+ let mut info = [0u8; INFO_SIZE];
+ info.copy_from_slice(&body[..INFO_SIZE]);
+ mem::transmute(info)
+ };
// trace log
log::trace!(
@@ -191,13 +238,16 @@ impl Status for LinuxTunStatus {
);
debug_assert_eq!(info.__ifi_pad, 0);
- // handle up / down
- if info.ifi_flags & (libc::IFF_UP as u32) != 0 {
- log::trace!("netlink, up event");
- self.events.push(TunEvent::Up(1420));
- } else {
- log::trace!("netlink, down event");
- self.events.push(TunEvent::Down);
+ if info.ifi_index == self.index {
+ // handle up / down
+ if info.ifi_flags & (libc::IFF_UP as u32) != 0 {
+ let mtu = get_mtu(&self.name)?;
+ log::trace!("netlink, up event, mtu = {}", mtu);
+ self.events.push(TunEvent::Up(mtu));
+ } else {
+ log::trace!("netlink, down event");
+ self.events.push(TunEvent::Down);
+ }
}
}
_ => (),
@@ -215,7 +265,7 @@ impl LinuxTunStatus {
const RTNLGRP_IPV4_IFADDR: libc::c_uint = 5;
const RTNLGRP_IPV6_IFADDR: libc::c_uint = 9;
- fn new() -> Result<LinuxTunStatus, LinuxTunError> {
+ fn new(name: [u8; libc::IFNAMSIZ]) -> Result<LinuxTunStatus, LinuxTunError> {
// create netlink socket
let fd = unsafe { libc::socket(libc::AF_NETLINK, libc::SOCK_RAW, libc::NETLINK_ROUTE) };
if fd < 0 {
@@ -244,7 +294,12 @@ impl LinuxTunStatus {
if res != 0 {
Err(LinuxTunError::Closed)
} else {
- Ok(LinuxTunStatus { events: vec![], fd })
+ Ok(LinuxTunStatus {
+ events: vec![],
+ index: get_ifindex(&name),
+ fd,
+ name,
+ })
}
}
}
@@ -289,7 +344,7 @@ impl PlatformTun for LinuxTun {
Ok((
vec![LinuxTunReader { fd }], // TODO: enable multi-queue for Linux
LinuxTunWriter { fd },
- LinuxTunStatus::new()?,
+ LinuxTunStatus::new(req.name)?,
))
}
}