3 use crate::io::{self, IoSlice, IoSliceMut};
5 use crate::net::{Shutdown, SocketAddr};
7 use crate::sys::fd::FileDesc;
8 use crate::sys_common::net::{getsockopt, setsockopt, sockaddr_to_addr};
9 use crate::sys_common::{AsInner, FromInner, IntoInner};
10 use crate::time::{Duration, Instant};
12 use libc::{c_int, c_void, size_t, sockaddr, socklen_t, EAI_SYSTEM, MSG_PEEK};
14 pub use crate::sys::{cvt, cvt_r};
16 #[allow(unused_extern_crates)]
17 pub extern crate libc as netc;
19 pub type wrlen_t = size_t;
21 pub struct Socket(FileDesc);
25 pub fn cvt_gai(err: c_int) -> io::Result<()> {
30 // We may need to trigger a glibc workaround. See on_resolver_failure() for details.
31 on_resolver_failure();
33 if err == EAI_SYSTEM {
34 return Err(io::Error::last_os_error());
38 str::from_utf8(CStr::from_ptr(libc::gai_strerror(err)).to_bytes()).unwrap().to_owned()
42 &format!("failed to lookup address information: {}", detail)[..],
47 pub fn new(addr: &SocketAddr, ty: c_int) -> io::Result<Socket> {
48 let fam = match *addr {
49 SocketAddr::V4(..) => libc::AF_INET,
50 SocketAddr::V6(..) => libc::AF_INET6,
52 Socket::new_raw(fam, ty)
55 pub fn new_raw(fam: c_int, ty: c_int) -> io::Result<Socket> {
58 if #[cfg(target_os = "linux")] {
59 // On Linux we pass the SOCK_CLOEXEC flag to atomically create
60 // the socket and set it as CLOEXEC, added in 2.6.27.
61 let fd = cvt(libc::socket(fam, ty | libc::SOCK_CLOEXEC, 0))?;
62 Ok(Socket(FileDesc::new(fd)))
64 let fd = cvt(libc::socket(fam, ty, 0))?;
65 let fd = FileDesc::new(fd);
67 let socket = Socket(fd);
69 // macOS and iOS use `SO_NOSIGPIPE` as a `setsockopt`
70 // flag to disable `SIGPIPE` emission on socket.
71 #[cfg(target_vendor = "apple")]
72 setsockopt(&socket, libc::SOL_SOCKET, libc::SO_NOSIGPIPE, 1)?;
80 #[cfg(not(target_os = "vxworks"))]
81 pub fn new_pair(fam: c_int, ty: c_int) -> io::Result<(Socket, Socket)> {
86 if #[cfg(target_os = "linux")] {
87 // Like above, set cloexec atomically
88 cvt(libc::socketpair(fam, ty | libc::SOCK_CLOEXEC, 0, fds.as_mut_ptr()))?;
89 Ok((Socket(FileDesc::new(fds[0])), Socket(FileDesc::new(fds[1]))))
91 cvt(libc::socketpair(fam, ty, 0, fds.as_mut_ptr()))?;
92 let a = FileDesc::new(fds[0]);
93 let b = FileDesc::new(fds[1]);
96 Ok((Socket(a), Socket(b)))
102 #[cfg(target_os = "vxworks")]
103 pub fn new_pair(_fam: c_int, _ty: c_int) -> io::Result<(Socket, Socket)> {
107 pub fn connect_timeout(&self, addr: &SocketAddr, timeout: Duration) -> io::Result<()> {
108 self.set_nonblocking(true)?;
110 let (addrp, len) = addr.into_inner();
111 cvt(libc::connect(self.0.raw(), addrp, len))
113 self.set_nonblocking(false)?;
116 Ok(_) => return Ok(()),
117 // there's no ErrorKind for EINPROGRESS :(
118 Err(ref e) if e.raw_os_error() == Some(libc::EINPROGRESS) => {}
119 Err(e) => return Err(e),
122 let mut pollfd = libc::pollfd { fd: self.0.raw(), events: libc::POLLOUT, revents: 0 };
124 if timeout.as_secs() == 0 && timeout.subsec_nanos() == 0 {
125 return Err(io::Error::new(
126 io::ErrorKind::InvalidInput,
127 "cannot set a 0 duration timeout",
131 let start = Instant::now();
134 let elapsed = start.elapsed();
135 if elapsed >= timeout {
136 return Err(io::Error::new(io::ErrorKind::TimedOut, "connection timed out"));
139 let timeout = timeout - elapsed;
140 let mut timeout = timeout
142 .saturating_mul(1_000)
143 .saturating_add(timeout.subsec_nanos() as u64 / 1_000_000);
148 let timeout = cmp::min(timeout, c_int::MAX as u64) as c_int;
150 match unsafe { libc::poll(&mut pollfd, 1, timeout) } {
152 let err = io::Error::last_os_error();
153 if err.kind() != io::ErrorKind::Interrupted {
159 // linux returns POLLOUT|POLLERR|POLLHUP for refused connections (!), so look
160 // for POLLHUP rather than read readiness
161 if pollfd.revents & libc::POLLHUP != 0 {
162 let e = self.take_error()?.unwrap_or_else(|| {
163 io::Error::new(io::ErrorKind::Other, "no error set after POLLHUP")
174 pub fn accept(&self, storage: *mut sockaddr, len: *mut socklen_t) -> io::Result<Socket> {
175 // Unfortunately the only known way right now to accept a socket and
176 // atomically set the CLOEXEC flag is to use the `accept4` syscall on
177 // Linux. This was added in 2.6.28, glibc 2.10 and musl 0.9.5.
179 if #[cfg(target_os = "linux")] {
180 let fd = cvt_r(|| unsafe {
181 libc::accept4(self.0.raw(), storage, len, libc::SOCK_CLOEXEC)
183 Ok(Socket(FileDesc::new(fd)))
185 let fd = cvt_r(|| unsafe { libc::accept(self.0.raw(), storage, len) })?;
186 let fd = FileDesc::new(fd);
193 pub fn duplicate(&self) -> io::Result<Socket> {
194 self.0.duplicate().map(Socket)
197 fn recv_with_flags(&self, buf: &mut [u8], flags: c_int) -> io::Result<usize> {
198 let ret = cvt(unsafe {
199 libc::recv(self.0.raw(), buf.as_mut_ptr() as *mut c_void, buf.len(), flags)
204 pub fn read(&self, buf: &mut [u8]) -> io::Result<usize> {
205 self.recv_with_flags(buf, 0)
208 pub fn peek(&self, buf: &mut [u8]) -> io::Result<usize> {
209 self.recv_with_flags(buf, MSG_PEEK)
212 pub fn read_vectored(&self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
213 self.0.read_vectored(bufs)
217 pub fn is_read_vectored(&self) -> bool {
218 self.0.is_read_vectored()
221 fn recv_from_with_flags(
225 ) -> io::Result<(usize, SocketAddr)> {
226 let mut storage: libc::sockaddr_storage = unsafe { mem::zeroed() };
227 let mut addrlen = mem::size_of_val(&storage) as libc::socklen_t;
232 buf.as_mut_ptr() as *mut c_void,
235 &mut storage as *mut _ as *mut _,
239 Ok((n as usize, sockaddr_to_addr(&storage, addrlen as usize)?))
242 pub fn recv_from(&self, buf: &mut [u8]) -> io::Result<(usize, SocketAddr)> {
243 self.recv_from_with_flags(buf, 0)
246 pub fn peek_from(&self, buf: &mut [u8]) -> io::Result<(usize, SocketAddr)> {
247 self.recv_from_with_flags(buf, MSG_PEEK)
250 pub fn write(&self, buf: &[u8]) -> io::Result<usize> {
254 pub fn write_vectored(&self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
255 self.0.write_vectored(bufs)
259 pub fn is_write_vectored(&self) -> bool {
260 self.0.is_write_vectored()
263 pub fn set_timeout(&self, dur: Option<Duration>, kind: libc::c_int) -> io::Result<()> {
264 let timeout = match dur {
266 if dur.as_secs() == 0 && dur.subsec_nanos() == 0 {
267 return Err(io::Error::new(
268 io::ErrorKind::InvalidInput,
269 "cannot set a 0 duration timeout",
273 let secs = if dur.as_secs() > libc::time_t::MAX as u64 {
276 dur.as_secs() as libc::time_t
278 let mut timeout = libc::timeval {
280 tv_usec: dur.subsec_micros() as libc::suseconds_t,
282 if timeout.tv_sec == 0 && timeout.tv_usec == 0 {
287 None => libc::timeval { tv_sec: 0, tv_usec: 0 },
289 setsockopt(self, libc::SOL_SOCKET, kind, timeout)
292 pub fn timeout(&self, kind: libc::c_int) -> io::Result<Option<Duration>> {
293 let raw: libc::timeval = getsockopt(self, libc::SOL_SOCKET, kind)?;
294 if raw.tv_sec == 0 && raw.tv_usec == 0 {
297 let sec = raw.tv_sec as u64;
298 let nsec = (raw.tv_usec as u32) * 1000;
299 Ok(Some(Duration::new(sec, nsec)))
303 pub fn shutdown(&self, how: Shutdown) -> io::Result<()> {
304 let how = match how {
305 Shutdown::Write => libc::SHUT_WR,
306 Shutdown::Read => libc::SHUT_RD,
307 Shutdown::Both => libc::SHUT_RDWR,
309 cvt(unsafe { libc::shutdown(self.0.raw(), how) })?;
313 pub fn set_nodelay(&self, nodelay: bool) -> io::Result<()> {
314 setsockopt(self, libc::IPPROTO_TCP, libc::TCP_NODELAY, nodelay as c_int)
317 pub fn nodelay(&self) -> io::Result<bool> {
318 let raw: c_int = getsockopt(self, libc::IPPROTO_TCP, libc::TCP_NODELAY)?;
322 #[cfg(not(any(target_os = "solaris", target_os = "illumos")))]
323 pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
324 let mut nonblocking = nonblocking as libc::c_int;
325 cvt(unsafe { libc::ioctl(*self.as_inner(), libc::FIONBIO, &mut nonblocking) }).map(drop)
328 #[cfg(any(target_os = "solaris", target_os = "illumos"))]
329 pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
330 // FIONBIO is inadequate for sockets on illumos/Solaris, so use the
331 // fcntl(F_[GS]ETFL)-based method provided by FileDesc instead.
332 self.0.set_nonblocking(nonblocking)
335 pub fn take_error(&self) -> io::Result<Option<io::Error>> {
336 let raw: c_int = getsockopt(self, libc::SOL_SOCKET, libc::SO_ERROR)?;
337 if raw == 0 { Ok(None) } else { Ok(Some(io::Error::from_raw_os_error(raw as i32))) }
341 impl AsInner<c_int> for Socket {
342 fn as_inner(&self) -> &c_int {
347 impl FromInner<c_int> for Socket {
348 fn from_inner(fd: c_int) -> Socket {
349 Socket(FileDesc::new(fd))
353 impl IntoInner<c_int> for Socket {
354 fn into_inner(self) -> c_int {
359 // In versions of glibc prior to 2.26, there's a bug where the DNS resolver
360 // will cache the contents of /etc/resolv.conf, so changes to that file on disk
361 // can be ignored by a long-running program. That can break DNS lookups on e.g.
362 // laptops where the network comes and goes. See
363 // https://sourceware.org/bugzilla/show_bug.cgi?id=984. Note however that some
364 // distros including Debian have patched glibc to fix this for a long time.
366 // A workaround for this bug is to call the res_init libc function, to clear
367 // the cached configs. Unfortunately, while we believe glibc's implementation
368 // of res_init is thread-safe, we know that other implementations are not
369 // (https://github.com/rust-lang/rust/issues/43592). Code here in libstd could
370 // try to synchronize its res_init calls with a Mutex, but that wouldn't
371 // protect programs that call into libc in other ways. So instead of calling
372 // res_init unconditionally, we call it only when we detect we're linking
373 // against glibc version < 2.26. (That is, when we both know its needed and
374 // believe it's thread-safe).
375 #[cfg(all(target_env = "gnu", not(target_os = "vxworks")))]
376 fn on_resolver_failure() {
379 // If the version fails to parse, we treat it the same as "not glibc".
380 if let Some(version) = sys::os::glibc_version() {
381 if version < (2, 26) {
382 unsafe { libc::res_init() };
387 #[cfg(any(not(target_env = "gnu"), target_os = "vxworks"))]
388 fn on_resolver_failure() {}