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> {
59 target_os = "android",
60 target_os = "dragonfly",
61 target_os = "freebsd",
62 target_os = "illumos",
65 target_os = "opensbd",
67 // On platforms that support it we pass the SOCK_CLOEXEC
68 // flag to atomically create the socket and set it as
69 // CLOEXEC. On Linux this was added in 2.6.27.
70 let fd = cvt(libc::socket(fam, ty | libc::SOCK_CLOEXEC, 0))?;
71 Ok(Socket(FileDesc::new(fd)))
73 let fd = cvt(libc::socket(fam, ty, 0))?;
74 let fd = FileDesc::new(fd);
76 let socket = Socket(fd);
78 // macOS and iOS use `SO_NOSIGPIPE` as a `setsockopt`
79 // flag to disable `SIGPIPE` emission on socket.
80 #[cfg(target_vendor = "apple")]
81 setsockopt(&socket, libc::SOL_SOCKET, libc::SO_NOSIGPIPE, 1)?;
89 #[cfg(not(target_os = "vxworks"))]
90 pub fn new_pair(fam: c_int, ty: c_int) -> io::Result<(Socket, Socket)> {
96 target_os = "android",
97 target_os = "dragonfly",
98 target_os = "freebsd",
99 target_os = "illumos",
101 target_os = "netbsd",
102 target_os = "opensbd",
104 // Like above, set cloexec atomically
105 cvt(libc::socketpair(fam, ty | libc::SOCK_CLOEXEC, 0, fds.as_mut_ptr()))?;
106 Ok((Socket(FileDesc::new(fds[0])), Socket(FileDesc::new(fds[1]))))
108 cvt(libc::socketpair(fam, ty, 0, fds.as_mut_ptr()))?;
109 let a = FileDesc::new(fds[0]);
110 let b = FileDesc::new(fds[1]);
113 Ok((Socket(a), Socket(b)))
119 #[cfg(target_os = "vxworks")]
120 pub fn new_pair(_fam: c_int, _ty: c_int) -> io::Result<(Socket, Socket)> {
124 pub fn connect_timeout(&self, addr: &SocketAddr, timeout: Duration) -> io::Result<()> {
125 self.set_nonblocking(true)?;
127 let (addrp, len) = addr.into_inner();
128 cvt(libc::connect(self.0.raw(), addrp, len))
130 self.set_nonblocking(false)?;
133 Ok(_) => return Ok(()),
134 // there's no ErrorKind for EINPROGRESS :(
135 Err(ref e) if e.raw_os_error() == Some(libc::EINPROGRESS) => {}
136 Err(e) => return Err(e),
139 let mut pollfd = libc::pollfd { fd: self.0.raw(), events: libc::POLLOUT, revents: 0 };
141 if timeout.as_secs() == 0 && timeout.subsec_nanos() == 0 {
142 return Err(io::Error::new_const(
143 io::ErrorKind::InvalidInput,
144 &"cannot set a 0 duration timeout",
148 let start = Instant::now();
151 let elapsed = start.elapsed();
152 if elapsed >= timeout {
153 return Err(io::Error::new_const(io::ErrorKind::TimedOut, &"connection timed out"));
156 let timeout = timeout - elapsed;
157 let mut timeout = timeout
159 .saturating_mul(1_000)
160 .saturating_add(timeout.subsec_nanos() as u64 / 1_000_000);
165 let timeout = cmp::min(timeout, c_int::MAX as u64) as c_int;
167 match unsafe { libc::poll(&mut pollfd, 1, timeout) } {
169 let err = io::Error::last_os_error();
170 if err.kind() != io::ErrorKind::Interrupted {
176 // linux returns POLLOUT|POLLERR|POLLHUP for refused connections (!), so look
177 // for POLLHUP rather than read readiness
178 if pollfd.revents & libc::POLLHUP != 0 {
179 let e = self.take_error()?.unwrap_or_else(|| {
180 io::Error::new_const(
181 io::ErrorKind::Other,
182 &"no error set after POLLHUP",
194 pub fn accept(&self, storage: *mut sockaddr, len: *mut socklen_t) -> io::Result<Socket> {
195 // Unfortunately the only known way right now to accept a socket and
196 // atomically set the CLOEXEC flag is to use the `accept4` syscall on
197 // platforms that support it. On Linux, this was added in 2.6.28,
198 // glibc 2.10 and musl 0.9.5.
201 target_os = "android",
202 target_os = "dragonfly",
203 target_os = "freebsd",
204 target_os = "illumos",
206 target_os = "netbsd",
207 target_os = "opensbd",
209 let fd = cvt_r(|| unsafe {
210 libc::accept4(self.0.raw(), storage, len, libc::SOCK_CLOEXEC)
212 Ok(Socket(FileDesc::new(fd)))
214 let fd = cvt_r(|| unsafe { libc::accept(self.0.raw(), storage, len) })?;
215 let fd = FileDesc::new(fd);
222 pub fn duplicate(&self) -> io::Result<Socket> {
223 self.0.duplicate().map(Socket)
226 fn recv_with_flags(&self, buf: &mut [u8], flags: c_int) -> io::Result<usize> {
227 let ret = cvt(unsafe {
228 libc::recv(self.0.raw(), buf.as_mut_ptr() as *mut c_void, buf.len(), flags)
233 pub fn read(&self, buf: &mut [u8]) -> io::Result<usize> {
234 self.recv_with_flags(buf, 0)
237 pub fn peek(&self, buf: &mut [u8]) -> io::Result<usize> {
238 self.recv_with_flags(buf, MSG_PEEK)
241 pub fn read_vectored(&self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
242 self.0.read_vectored(bufs)
246 pub fn is_read_vectored(&self) -> bool {
247 self.0.is_read_vectored()
250 fn recv_from_with_flags(
254 ) -> io::Result<(usize, SocketAddr)> {
255 let mut storage: libc::sockaddr_storage = unsafe { mem::zeroed() };
256 let mut addrlen = mem::size_of_val(&storage) as libc::socklen_t;
261 buf.as_mut_ptr() as *mut c_void,
264 &mut storage as *mut _ as *mut _,
268 Ok((n as usize, sockaddr_to_addr(&storage, addrlen as usize)?))
271 pub fn recv_from(&self, buf: &mut [u8]) -> io::Result<(usize, SocketAddr)> {
272 self.recv_from_with_flags(buf, 0)
276 target_os = "android",
277 target_os = "dragonfly",
278 target_os = "emscripten",
279 target_os = "freebsd",
281 target_os = "netbsd",
282 target_os = "openbsd",
284 pub fn recv_msg(&self, msg: &mut libc::msghdr) -> io::Result<usize> {
285 let n = cvt(unsafe { libc::recvmsg(self.0.raw(), msg, libc::MSG_CMSG_CLOEXEC) })?;
289 pub fn peek_from(&self, buf: &mut [u8]) -> io::Result<(usize, SocketAddr)> {
290 self.recv_from_with_flags(buf, MSG_PEEK)
293 pub fn write(&self, buf: &[u8]) -> io::Result<usize> {
297 pub fn write_vectored(&self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
298 self.0.write_vectored(bufs)
302 pub fn is_write_vectored(&self) -> bool {
303 self.0.is_write_vectored()
307 target_os = "android",
308 target_os = "dragonfly",
309 target_os = "emscripten",
310 target_os = "freebsd",
312 target_os = "netbsd",
313 target_os = "openbsd",
315 pub fn send_msg(&self, msg: &mut libc::msghdr) -> io::Result<usize> {
316 let n = cvt(unsafe { libc::sendmsg(self.0.raw(), msg, 0) })?;
320 pub fn set_timeout(&self, dur: Option<Duration>, kind: libc::c_int) -> io::Result<()> {
321 let timeout = match dur {
323 if dur.as_secs() == 0 && dur.subsec_nanos() == 0 {
324 return Err(io::Error::new_const(
325 io::ErrorKind::InvalidInput,
326 &"cannot set a 0 duration timeout",
330 let secs = if dur.as_secs() > libc::time_t::MAX as u64 {
333 dur.as_secs() as libc::time_t
335 let mut timeout = libc::timeval {
337 tv_usec: dur.subsec_micros() as libc::suseconds_t,
339 if timeout.tv_sec == 0 && timeout.tv_usec == 0 {
344 None => libc::timeval { tv_sec: 0, tv_usec: 0 },
346 setsockopt(self, libc::SOL_SOCKET, kind, timeout)
349 pub fn timeout(&self, kind: libc::c_int) -> io::Result<Option<Duration>> {
350 let raw: libc::timeval = getsockopt(self, libc::SOL_SOCKET, kind)?;
351 if raw.tv_sec == 0 && raw.tv_usec == 0 {
354 let sec = raw.tv_sec as u64;
355 let nsec = (raw.tv_usec as u32) * 1000;
356 Ok(Some(Duration::new(sec, nsec)))
360 pub fn shutdown(&self, how: Shutdown) -> io::Result<()> {
361 let how = match how {
362 Shutdown::Write => libc::SHUT_WR,
363 Shutdown::Read => libc::SHUT_RD,
364 Shutdown::Both => libc::SHUT_RDWR,
366 cvt(unsafe { libc::shutdown(self.0.raw(), how) })?;
370 pub fn set_nodelay(&self, nodelay: bool) -> io::Result<()> {
371 setsockopt(self, libc::IPPROTO_TCP, libc::TCP_NODELAY, nodelay as c_int)
374 pub fn nodelay(&self) -> io::Result<bool> {
375 let raw: c_int = getsockopt(self, libc::IPPROTO_TCP, libc::TCP_NODELAY)?;
379 #[cfg(any(target_os = "android", target_os = "linux",))]
380 pub fn set_passcred(&self, passcred: bool) -> io::Result<()> {
381 setsockopt(self, libc::SOL_SOCKET, libc::SO_PASSCRED, passcred as libc::c_int)
384 #[cfg(any(target_os = "android", target_os = "linux",))]
385 pub fn passcred(&self) -> io::Result<bool> {
386 let passcred: libc::c_int = getsockopt(self, libc::SOL_SOCKET, libc::SO_PASSCRED)?;
390 #[cfg(not(any(target_os = "solaris", target_os = "illumos")))]
391 pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
392 let mut nonblocking = nonblocking as libc::c_int;
393 cvt(unsafe { libc::ioctl(*self.as_inner(), libc::FIONBIO, &mut nonblocking) }).map(drop)
396 #[cfg(any(target_os = "solaris", target_os = "illumos"))]
397 pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
398 // FIONBIO is inadequate for sockets on illumos/Solaris, so use the
399 // fcntl(F_[GS]ETFL)-based method provided by FileDesc instead.
400 self.0.set_nonblocking(nonblocking)
403 pub fn take_error(&self) -> io::Result<Option<io::Error>> {
404 let raw: c_int = getsockopt(self, libc::SOL_SOCKET, libc::SO_ERROR)?;
405 if raw == 0 { Ok(None) } else { Ok(Some(io::Error::from_raw_os_error(raw as i32))) }
409 impl AsInner<c_int> for Socket {
410 fn as_inner(&self) -> &c_int {
415 impl FromInner<c_int> for Socket {
416 fn from_inner(fd: c_int) -> Socket {
417 Socket(FileDesc::new(fd))
421 impl IntoInner<c_int> for Socket {
422 fn into_inner(self) -> c_int {
427 // In versions of glibc prior to 2.26, there's a bug where the DNS resolver
428 // will cache the contents of /etc/resolv.conf, so changes to that file on disk
429 // can be ignored by a long-running program. That can break DNS lookups on e.g.
430 // laptops where the network comes and goes. See
431 // https://sourceware.org/bugzilla/show_bug.cgi?id=984. Note however that some
432 // distros including Debian have patched glibc to fix this for a long time.
434 // A workaround for this bug is to call the res_init libc function, to clear
435 // the cached configs. Unfortunately, while we believe glibc's implementation
436 // of res_init is thread-safe, we know that other implementations are not
437 // (https://github.com/rust-lang/rust/issues/43592). Code here in libstd could
438 // try to synchronize its res_init calls with a Mutex, but that wouldn't
439 // protect programs that call into libc in other ways. So instead of calling
440 // res_init unconditionally, we call it only when we detect we're linking
441 // against glibc version < 2.26. (That is, when we both know its needed and
442 // believe it's thread-safe).
443 #[cfg(all(target_env = "gnu", not(target_os = "vxworks")))]
444 fn on_resolver_failure() {
447 // If the version fails to parse, we treat it the same as "not glibc".
448 if let Some(version) = sys::os::glibc_version() {
449 if version < (2, 26) {
450 unsafe { libc::res_init() };
455 #[cfg(any(not(target_env = "gnu"), target_os = "vxworks"))]
456 fn on_resolver_failure() {}