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, 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 #[cfg(not(target_os = "espidf"))]
34 if err == libc::EAI_SYSTEM {
35 return Err(io::Error::last_os_error());
38 #[cfg(not(target_os = "espidf"))]
40 str::from_utf8(CStr::from_ptr(libc::gai_strerror(err)).to_bytes()).unwrap().to_owned()
43 #[cfg(target_os = "espidf")]
47 io::ErrorKind::Uncategorized,
48 &format!("failed to lookup address information: {}", detail)[..],
53 pub fn new(addr: &SocketAddr, ty: c_int) -> io::Result<Socket> {
54 let fam = match *addr {
55 SocketAddr::V4(..) => libc::AF_INET,
56 SocketAddr::V6(..) => libc::AF_INET6,
58 Socket::new_raw(fam, ty)
61 pub fn new_raw(fam: c_int, ty: c_int) -> io::Result<Socket> {
65 target_os = "android",
66 target_os = "dragonfly",
67 target_os = "freebsd",
68 target_os = "illumos",
71 target_os = "openbsd",
73 // On platforms that support it we pass the SOCK_CLOEXEC
74 // flag to atomically create the socket and set it as
75 // CLOEXEC. On Linux this was added in 2.6.27.
76 let fd = cvt(libc::socket(fam, ty | libc::SOCK_CLOEXEC, 0))?;
77 Ok(Socket(FileDesc::new(fd)))
79 let fd = cvt(libc::socket(fam, ty, 0))?;
80 let fd = FileDesc::new(fd);
82 let socket = Socket(fd);
84 // macOS and iOS use `SO_NOSIGPIPE` as a `setsockopt`
85 // flag to disable `SIGPIPE` emission on socket.
86 #[cfg(target_vendor = "apple")]
87 setsockopt(&socket, libc::SOL_SOCKET, libc::SO_NOSIGPIPE, 1)?;
95 #[cfg(not(target_os = "vxworks"))]
96 pub fn new_pair(fam: c_int, ty: c_int) -> io::Result<(Socket, Socket)> {
102 target_os = "android",
103 target_os = "dragonfly",
104 target_os = "freebsd",
105 target_os = "illumos",
107 target_os = "netbsd",
108 target_os = "openbsd",
110 // Like above, set cloexec atomically
111 cvt(libc::socketpair(fam, ty | libc::SOCK_CLOEXEC, 0, fds.as_mut_ptr()))?;
112 Ok((Socket(FileDesc::new(fds[0])), Socket(FileDesc::new(fds[1]))))
114 cvt(libc::socketpair(fam, ty, 0, fds.as_mut_ptr()))?;
115 let a = FileDesc::new(fds[0]);
116 let b = FileDesc::new(fds[1]);
119 Ok((Socket(a), Socket(b)))
125 #[cfg(target_os = "vxworks")]
126 pub fn new_pair(_fam: c_int, _ty: c_int) -> io::Result<(Socket, Socket)> {
130 pub fn connect_timeout(&self, addr: &SocketAddr, timeout: Duration) -> io::Result<()> {
131 self.set_nonblocking(true)?;
133 let (addrp, len) = addr.into_inner();
134 cvt(libc::connect(self.0.raw(), addrp, len))
136 self.set_nonblocking(false)?;
139 Ok(_) => return Ok(()),
140 // there's no ErrorKind for EINPROGRESS :(
141 Err(ref e) if e.raw_os_error() == Some(libc::EINPROGRESS) => {}
142 Err(e) => return Err(e),
145 let mut pollfd = libc::pollfd { fd: self.0.raw(), events: libc::POLLOUT, revents: 0 };
147 if timeout.as_secs() == 0 && timeout.subsec_nanos() == 0 {
148 return Err(io::Error::new_const(
149 io::ErrorKind::InvalidInput,
150 &"cannot set a 0 duration timeout",
154 let start = Instant::now();
157 let elapsed = start.elapsed();
158 if elapsed >= timeout {
159 return Err(io::Error::new_const(io::ErrorKind::TimedOut, &"connection timed out"));
162 let timeout = timeout - elapsed;
163 let mut timeout = timeout
165 .saturating_mul(1_000)
166 .saturating_add(timeout.subsec_nanos() as u64 / 1_000_000);
171 let timeout = cmp::min(timeout, c_int::MAX as u64) as c_int;
173 match unsafe { libc::poll(&mut pollfd, 1, timeout) } {
175 let err = io::Error::last_os_error();
176 if err.kind() != io::ErrorKind::Interrupted {
182 // linux returns POLLOUT|POLLERR|POLLHUP for refused connections (!), so look
183 // for POLLHUP rather than read readiness
184 if pollfd.revents & libc::POLLHUP != 0 {
185 let e = self.take_error()?.unwrap_or_else(|| {
186 io::Error::new_const(
187 io::ErrorKind::Uncategorized,
188 &"no error set after POLLHUP",
200 pub fn accept(&self, storage: *mut sockaddr, len: *mut socklen_t) -> io::Result<Socket> {
201 // Unfortunately the only known way right now to accept a socket and
202 // atomically set the CLOEXEC flag is to use the `accept4` syscall on
203 // platforms that support it. On Linux, this was added in 2.6.28,
204 // glibc 2.10 and musl 0.9.5.
207 target_os = "android",
208 target_os = "dragonfly",
209 target_os = "freebsd",
210 target_os = "illumos",
212 target_os = "netbsd",
213 target_os = "openbsd",
215 let fd = cvt_r(|| unsafe {
216 libc::accept4(self.0.raw(), storage, len, libc::SOCK_CLOEXEC)
218 Ok(Socket(FileDesc::new(fd)))
220 let fd = cvt_r(|| unsafe { libc::accept(self.0.raw(), storage, len) })?;
221 let fd = FileDesc::new(fd);
228 pub fn duplicate(&self) -> io::Result<Socket> {
229 self.0.duplicate().map(Socket)
232 fn recv_with_flags(&self, buf: &mut [u8], flags: c_int) -> io::Result<usize> {
233 let ret = cvt(unsafe {
234 libc::recv(self.0.raw(), buf.as_mut_ptr() as *mut c_void, buf.len(), flags)
239 pub fn read(&self, buf: &mut [u8]) -> io::Result<usize> {
240 self.recv_with_flags(buf, 0)
243 pub fn peek(&self, buf: &mut [u8]) -> io::Result<usize> {
244 self.recv_with_flags(buf, MSG_PEEK)
247 pub fn read_vectored(&self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
248 self.0.read_vectored(bufs)
252 pub fn is_read_vectored(&self) -> bool {
253 self.0.is_read_vectored()
256 fn recv_from_with_flags(
260 ) -> io::Result<(usize, SocketAddr)> {
261 let mut storage: libc::sockaddr_storage = unsafe { mem::zeroed() };
262 let mut addrlen = mem::size_of_val(&storage) as libc::socklen_t;
267 buf.as_mut_ptr() as *mut c_void,
270 &mut storage as *mut _ as *mut _,
274 Ok((n as usize, sockaddr_to_addr(&storage, addrlen as usize)?))
277 pub fn recv_from(&self, buf: &mut [u8]) -> io::Result<(usize, SocketAddr)> {
278 self.recv_from_with_flags(buf, 0)
282 target_os = "android",
283 target_os = "dragonfly",
284 target_os = "emscripten",
285 target_os = "freebsd",
287 target_os = "netbsd",
288 target_os = "openbsd",
290 pub fn recv_msg(&self, msg: &mut libc::msghdr) -> io::Result<usize> {
291 let n = cvt(unsafe { libc::recvmsg(self.0.raw(), msg, libc::MSG_CMSG_CLOEXEC) })?;
295 pub fn peek_from(&self, buf: &mut [u8]) -> io::Result<(usize, SocketAddr)> {
296 self.recv_from_with_flags(buf, MSG_PEEK)
299 pub fn write(&self, buf: &[u8]) -> io::Result<usize> {
303 pub fn write_vectored(&self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
304 self.0.write_vectored(bufs)
308 pub fn is_write_vectored(&self) -> bool {
309 self.0.is_write_vectored()
313 target_os = "android",
314 target_os = "dragonfly",
315 target_os = "emscripten",
316 target_os = "freebsd",
318 target_os = "netbsd",
319 target_os = "openbsd",
321 pub fn send_msg(&self, msg: &mut libc::msghdr) -> io::Result<usize> {
322 let n = cvt(unsafe { libc::sendmsg(self.0.raw(), msg, 0) })?;
326 pub fn set_timeout(&self, dur: Option<Duration>, kind: libc::c_int) -> io::Result<()> {
327 let timeout = match dur {
329 if dur.as_secs() == 0 && dur.subsec_nanos() == 0 {
330 return Err(io::Error::new_const(
331 io::ErrorKind::InvalidInput,
332 &"cannot set a 0 duration timeout",
336 let secs = if dur.as_secs() > libc::time_t::MAX as u64 {
339 dur.as_secs() as libc::time_t
341 let mut timeout = libc::timeval {
343 tv_usec: dur.subsec_micros() as libc::suseconds_t,
345 if timeout.tv_sec == 0 && timeout.tv_usec == 0 {
350 None => libc::timeval { tv_sec: 0, tv_usec: 0 },
352 setsockopt(self, libc::SOL_SOCKET, kind, timeout)
355 pub fn timeout(&self, kind: libc::c_int) -> io::Result<Option<Duration>> {
356 let raw: libc::timeval = getsockopt(self, libc::SOL_SOCKET, kind)?;
357 if raw.tv_sec == 0 && raw.tv_usec == 0 {
360 let sec = raw.tv_sec as u64;
361 let nsec = (raw.tv_usec as u32) * 1000;
362 Ok(Some(Duration::new(sec, nsec)))
366 pub fn shutdown(&self, how: Shutdown) -> io::Result<()> {
367 let how = match how {
368 Shutdown::Write => libc::SHUT_WR,
369 Shutdown::Read => libc::SHUT_RD,
370 Shutdown::Both => libc::SHUT_RDWR,
372 cvt(unsafe { libc::shutdown(self.0.raw(), how) })?;
376 pub fn set_nodelay(&self, nodelay: bool) -> io::Result<()> {
377 setsockopt(self, libc::IPPROTO_TCP, libc::TCP_NODELAY, nodelay as c_int)
380 pub fn nodelay(&self) -> io::Result<bool> {
381 let raw: c_int = getsockopt(self, libc::IPPROTO_TCP, libc::TCP_NODELAY)?;
385 #[cfg(any(target_os = "android", target_os = "linux",))]
386 pub fn set_passcred(&self, passcred: bool) -> io::Result<()> {
387 setsockopt(self, libc::SOL_SOCKET, libc::SO_PASSCRED, passcred as libc::c_int)
390 #[cfg(any(target_os = "android", target_os = "linux",))]
391 pub fn passcred(&self) -> io::Result<bool> {
392 let passcred: libc::c_int = getsockopt(self, libc::SOL_SOCKET, libc::SO_PASSCRED)?;
396 #[cfg(not(any(target_os = "solaris", target_os = "illumos")))]
397 pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
398 let mut nonblocking = nonblocking as libc::c_int;
399 cvt(unsafe { libc::ioctl(*self.as_inner(), libc::FIONBIO, &mut nonblocking) }).map(drop)
402 #[cfg(any(target_os = "solaris", target_os = "illumos"))]
403 pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
404 // FIONBIO is inadequate for sockets on illumos/Solaris, so use the
405 // fcntl(F_[GS]ETFL)-based method provided by FileDesc instead.
406 self.0.set_nonblocking(nonblocking)
409 pub fn take_error(&self) -> io::Result<Option<io::Error>> {
410 let raw: c_int = getsockopt(self, libc::SOL_SOCKET, libc::SO_ERROR)?;
411 if raw == 0 { Ok(None) } else { Ok(Some(io::Error::from_raw_os_error(raw as i32))) }
415 impl AsInner<c_int> for Socket {
416 fn as_inner(&self) -> &c_int {
421 impl FromInner<c_int> for Socket {
422 fn from_inner(fd: c_int) -> Socket {
423 Socket(FileDesc::new(fd))
427 impl IntoInner<c_int> for Socket {
428 fn into_inner(self) -> c_int {
433 // In versions of glibc prior to 2.26, there's a bug where the DNS resolver
434 // will cache the contents of /etc/resolv.conf, so changes to that file on disk
435 // can be ignored by a long-running program. That can break DNS lookups on e.g.
436 // laptops where the network comes and goes. See
437 // https://sourceware.org/bugzilla/show_bug.cgi?id=984. Note however that some
438 // distros including Debian have patched glibc to fix this for a long time.
440 // A workaround for this bug is to call the res_init libc function, to clear
441 // the cached configs. Unfortunately, while we believe glibc's implementation
442 // of res_init is thread-safe, we know that other implementations are not
443 // (https://github.com/rust-lang/rust/issues/43592). Code here in libstd could
444 // try to synchronize its res_init calls with a Mutex, but that wouldn't
445 // protect programs that call into libc in other ways. So instead of calling
446 // res_init unconditionally, we call it only when we detect we're linking
447 // against glibc version < 2.26. (That is, when we both know its needed and
448 // believe it's thread-safe).
449 #[cfg(all(target_env = "gnu", not(target_os = "vxworks")))]
450 fn on_resolver_failure() {
453 // If the version fails to parse, we treat it the same as "not glibc".
454 if let Some(version) = sys::os::glibc_version() {
455 if version < (2, 26) {
456 unsafe { libc::res_init() };
461 #[cfg(any(not(target_env = "gnu"), target_os = "vxworks"))]
462 fn on_resolver_failure() {}