blob: 32c27ab6e9e8d4cb2247befc969929dcc4d44d95 [file] [log] [blame]
use crate::cmp;
use crate::ffi::CStr;
use crate::io;
use crate::io::{IoSlice, IoSliceMut};
use crate::mem;
use crate::net::{Shutdown, SocketAddr};
use crate::str;
use crate::sys::fd::FileDesc;
use crate::sys_common::net::{getsockopt, setsockopt, sockaddr_to_addr};
use crate::sys_common::{AsInner, FromInner, IntoInner};
use crate::time::{Duration, Instant};
use libc::{self, c_int, c_void, size_t, sockaddr, socklen_t, EAI_SYSTEM, MSG_PEEK};
pub use crate::sys::{cvt, cvt_r};
#[allow(unused_extern_crates)]
pub extern crate libc as netc;
pub type wrlen_t = size_t;
pub struct Socket(FileDesc);
pub fn init() {}
pub fn cvt_gai(err: c_int) -> io::Result<()> {
if err == 0 {
return Ok(());
}
// We may need to trigger a glibc workaround. See on_resolver_failure() for details.
on_resolver_failure();
if err == EAI_SYSTEM {
return Err(io::Error::last_os_error());
}
let detail = unsafe {
str::from_utf8(CStr::from_ptr(libc::gai_strerror(err)).to_bytes()).unwrap().to_owned()
};
Err(io::Error::new(
io::ErrorKind::Other,
&format!("failed to lookup address information: {}", detail)[..],
))
}
impl Socket {
pub fn new(addr: &SocketAddr, ty: c_int) -> io::Result<Socket> {
let fam = match *addr {
SocketAddr::V4(..) => libc::AF_INET,
SocketAddr::V6(..) => libc::AF_INET6,
};
Socket::new_raw(fam, ty)
}
pub fn new_raw(fam: c_int, ty: c_int) -> io::Result<Socket> {
unsafe {
let fd = cvt(libc::socket(fam, ty, 0))?;
let fd = FileDesc::new(fd);
fd.set_cloexec()?;
let socket = Socket(fd);
Ok(socket)
}
}
pub fn new_pair(_fam: c_int, _ty: c_int) -> io::Result<(Socket, Socket)> {
unimplemented!();
}
pub fn connect_timeout(&self, addr: &SocketAddr, timeout: Duration) -> io::Result<()> {
self.set_nonblocking(true)?;
let r = unsafe {
let (addrp, len) = addr.into_inner();
cvt(libc::connect(self.0.raw(), addrp, len))
};
self.set_nonblocking(false)?;
match r {
Ok(_) => return Ok(()),
// there's no ErrorKind for EINPROGRESS :(
Err(ref e) if e.raw_os_error() == Some(libc::EINPROGRESS) => {}
Err(e) => return Err(e),
}
let mut pollfd = libc::pollfd { fd: self.0.raw(), events: libc::POLLOUT, revents: 0 };
if timeout.as_secs() == 0 && timeout.subsec_nanos() == 0 {
return Err(io::Error::new(
io::ErrorKind::InvalidInput,
"cannot set a 0 duration timeout",
));
}
let start = Instant::now();
loop {
let elapsed = start.elapsed();
if elapsed >= timeout {
return Err(io::Error::new(io::ErrorKind::TimedOut, "connection timed out"));
}
let timeout = timeout - elapsed;
let mut timeout = timeout
.as_secs()
.saturating_mul(1_000)
.saturating_add(timeout.subsec_nanos() as u64 / 1_000_000);
if timeout == 0 {
timeout = 1;
}
let timeout = cmp::min(timeout, c_int::MAX as u64) as c_int;
match unsafe { libc::poll(&mut pollfd, 1, timeout) } {
-1 => {
let err = io::Error::last_os_error();
if err.kind() != io::ErrorKind::Interrupted {
return Err(err);
}
}
0 => {}
_ => {
// linux returns POLLOUT|POLLERR|POLLHUP for refused connections (!), so look
// for POLLHUP rather than read readiness
if pollfd.revents & libc::POLLHUP != 0 {
let e = self.take_error()?.unwrap_or_else(|| {
io::Error::new(io::ErrorKind::Other, "no error set after POLLHUP")
});
return Err(e);
}
return Ok(());
}
}
}
}
pub fn accept(&self, storage: *mut sockaddr, len: *mut socklen_t) -> io::Result<Socket> {
let fd = cvt_r(|| unsafe { libc::accept(self.0.raw(), storage, len) })?;
let fd = FileDesc::new(fd);
fd.set_cloexec()?;
Ok(Socket(fd))
}
pub fn duplicate(&self) -> io::Result<Socket> {
self.0.duplicate().map(Socket)
}
fn recv_with_flags(&self, buf: &mut [u8], flags: c_int) -> io::Result<usize> {
let ret = cvt(unsafe {
libc::recv(self.0.raw(), buf.as_mut_ptr() as *mut c_void, buf.len(), flags)
})?;
Ok(ret as usize)
}
pub fn read(&self, buf: &mut [u8]) -> io::Result<usize> {
self.recv_with_flags(buf, 0)
}
pub fn peek(&self, buf: &mut [u8]) -> io::Result<usize> {
self.recv_with_flags(buf, MSG_PEEK)
}
pub fn read_vectored(&self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
self.0.read_vectored(bufs)
}
#[inline]
pub fn is_read_vectored(&self) -> bool {
self.0.is_read_vectored()
}
fn recv_from_with_flags(
&self,
buf: &mut [u8],
flags: c_int,
) -> io::Result<(usize, SocketAddr)> {
let mut storage: libc::sockaddr_storage = unsafe { mem::zeroed() };
let mut addrlen = mem::size_of_val(&storage) as libc::socklen_t;
let n = cvt(unsafe {
libc::recvfrom(
self.0.raw(),
buf.as_mut_ptr() as *mut c_void,
buf.len(),
flags,
&mut storage as *mut _ as *mut _,
&mut addrlen,
)
})?;
Ok((n as usize, sockaddr_to_addr(&storage, addrlen as usize)?))
}
pub fn recv_from(&self, buf: &mut [u8]) -> io::Result<(usize, SocketAddr)> {
self.recv_from_with_flags(buf, 0)
}
pub fn peek_from(&self, buf: &mut [u8]) -> io::Result<(usize, SocketAddr)> {
self.recv_from_with_flags(buf, MSG_PEEK)
}
pub fn write(&self, buf: &[u8]) -> io::Result<usize> {
self.0.write(buf)
}
pub fn write_vectored(&self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
self.0.write_vectored(bufs)
}
#[inline]
pub fn is_write_vectored(&self) -> bool {
self.0.is_write_vectored()
}
pub fn set_timeout(&self, dur: Option<Duration>, kind: libc::c_int) -> io::Result<()> {
let timeout = match dur {
Some(dur) => {
if dur.as_secs() == 0 && dur.subsec_nanos() == 0 {
return Err(io::Error::new(
io::ErrorKind::InvalidInput,
"cannot set a 0 duration timeout",
));
}
let secs = if dur.as_secs() > libc::time_t::MAX as u64 {
libc::time_t::MAX
} else {
dur.as_secs() as libc::time_t
};
let mut timeout = libc::timeval {
tv_sec: secs,
tv_usec: (dur.subsec_nanos() / 1000) as libc::suseconds_t,
};
if timeout.tv_sec == 0 && timeout.tv_usec == 0 {
timeout.tv_usec = 1;
}
timeout
}
None => libc::timeval { tv_sec: 0, tv_usec: 0 },
};
setsockopt(self, libc::SOL_SOCKET, kind, timeout)
}
pub fn timeout(&self, kind: libc::c_int) -> io::Result<Option<Duration>> {
let raw: libc::timeval = getsockopt(self, libc::SOL_SOCKET, kind)?;
if raw.tv_sec == 0 && raw.tv_usec == 0 {
Ok(None)
} else {
let sec = raw.tv_sec as u64;
let nsec = (raw.tv_usec as u32) * 1000;
Ok(Some(Duration::new(sec, nsec)))
}
}
pub fn shutdown(&self, how: Shutdown) -> io::Result<()> {
let how = match how {
Shutdown::Write => libc::SHUT_WR,
Shutdown::Read => libc::SHUT_RD,
Shutdown::Both => libc::SHUT_RDWR,
};
cvt(unsafe { libc::shutdown(self.0.raw(), how) })?;
Ok(())
}
pub fn set_nodelay(&self, nodelay: bool) -> io::Result<()> {
setsockopt(self, libc::IPPROTO_TCP, libc::TCP_NODELAY, nodelay as c_int)
}
pub fn nodelay(&self) -> io::Result<bool> {
let raw: c_int = getsockopt(self, libc::IPPROTO_TCP, libc::TCP_NODELAY)?;
Ok(raw != 0)
}
pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
let mut nonblocking = nonblocking as libc::c_int;
cvt(unsafe { libc::ioctl(*self.as_inner(), libc::FIONBIO, &mut nonblocking) }).map(drop)
}
pub fn take_error(&self) -> io::Result<Option<io::Error>> {
let raw: c_int = getsockopt(self, libc::SOL_SOCKET, libc::SO_ERROR)?;
if raw == 0 { Ok(None) } else { Ok(Some(io::Error::from_raw_os_error(raw as i32))) }
}
}
impl AsInner<c_int> for Socket {
fn as_inner(&self) -> &c_int {
self.0.as_inner()
}
}
impl FromInner<c_int> for Socket {
fn from_inner(fd: c_int) -> Socket {
Socket(FileDesc::new(fd))
}
}
impl IntoInner<c_int> for Socket {
fn into_inner(self) -> c_int {
self.0.into_raw()
}
}
// In versions of glibc prior to 2.26, there's a bug where the DNS resolver
// will cache the contents of /etc/resolv.conf, so changes to that file on disk
// can be ignored by a long-running program. That can break DNS lookups on e.g.
// laptops where the network comes and goes. See
// https://sourceware.org/bugzilla/show_bug.cgi?id=984. Note however that some
// distros including Debian have patched glibc to fix this for a long time.
//
// A workaround for this bug is to call the res_init libc function, to clear
// the cached configs. Unfortunately, while we believe glibc's implementation
// of res_init is thread-safe, we know that other implementations are not
// (https://github.com/rust-lang/rust/issues/43592). Code here in libstd could
// try to synchronize its res_init calls with a Mutex, but that wouldn't
// protect programs that call into libc in other ways. So instead of calling
// res_init unconditionally, we call it only when we detect we're linking
// against glibc version < 2.26. (That is, when we both know its needed and
// believe it's thread-safe).
#[cfg(target_env = "gnu")]
fn on_resolver_failure() {
/*
use crate::sys;
// If the version fails to parse, we treat it the same as "not glibc".
if let Some(version) = sys::os::glibc_version() {
if version < (2, 26) {
unsafe { libc::res_init() };
}
}
*/
}
#[cfg(not(target_env = "gnu"))]
fn on_resolver_failure() {}
#[cfg(all(test, taget_env = "gnu"))]
mod test {
use super::*;
#[test]
fn test_res_init() {
// This mostly just tests that the weak linkage doesn't panic wildly...
res_init_if_glibc_before_2_26().unwrap();
}
#[test]
fn test_parse_glibc_version() {
let cases = [
("0.0", Some((0, 0))),
("01.+2", Some((1, 2))),
("3.4.5.six", Some((3, 4))),
("1", None),
("1.-2", None),
("1.foo", None),
("foo.1", None),
];
for &(version_str, parsed) in cases.iter() {
assert_eq!(parsed, parse_glibc_version(version_str));
}
}
}