| use crate::ffi::CStr; |
| use crate::io::{self, IoVec, IoVecMut}; |
| use crate::mem; |
| use crate::net::{SocketAddr, Shutdown}; |
| use crate::str; |
| use crate::sys::fd::FileDesc; |
| use crate::sys_common::{AsInner, FromInner, IntoInner}; |
| use crate::sys_common::net::{getsockopt, setsockopt, sockaddr_to_addr}; |
| use crate::time::{Duration, Instant}; |
| use crate::cmp; |
| |
| use libc::{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; |
| |
| // See below for the usage of SOCK_CLOEXEC, but this constant is only defined on |
| // Linux currently (e.g., support doesn't exist on other platforms). In order to |
| // get name resolution to work and things to compile we just define a dummy |
| // SOCK_CLOEXEC here for other platforms. Note that the dummy constant isn't |
| // actually ever used (the blocks below are wrapped in `if cfg!` as well. |
| #[cfg(target_os = "linux")] |
| use libc::SOCK_CLOEXEC; |
| #[cfg(not(target_os = "linux"))] |
| const SOCK_CLOEXEC: c_int = 0; |
| |
| // Another conditional constant for name resolution: Macos et iOS use |
| // SO_NOSIGPIPE as a setsockopt flag to disable SIGPIPE emission on socket. |
| // Other platforms do otherwise. |
| #[cfg(target_vendor = "apple")] |
| use libc::SO_NOSIGPIPE; |
| #[cfg(not(target_vendor = "apple"))] |
| const SO_NOSIGPIPE: c_int = 0; |
| |
| 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 { |
| // On linux we first attempt to pass the SOCK_CLOEXEC flag to |
| // atomically create the socket and set it as CLOEXEC. Support for |
| // this option, however, was added in 2.6.27, and we still support |
| // 2.6.18 as a kernel, so if the returned error is EINVAL we |
| // fallthrough to the fallback. |
| if cfg!(target_os = "linux") { |
| match cvt(libc::socket(fam, ty | SOCK_CLOEXEC, 0)) { |
| Ok(fd) => return Ok(Socket(FileDesc::new(fd))), |
| Err(ref e) if e.raw_os_error() == Some(libc::EINVAL) => {} |
| Err(e) => return Err(e), |
| } |
| } |
| |
| let fd = cvt(libc::socket(fam, ty, 0))?; |
| let fd = FileDesc::new(fd); |
| fd.set_cloexec()?; |
| let socket = Socket(fd); |
| if cfg!(target_vendor = "apple") { |
| setsockopt(&socket, libc::SOL_SOCKET, SO_NOSIGPIPE, 1)?; |
| } |
| Ok(socket) |
| } |
| } |
| |
| pub fn new_pair(fam: c_int, ty: c_int) -> io::Result<(Socket, Socket)> { |
| unsafe { |
| let mut fds = [0, 0]; |
| |
| // Like above, see if we can set cloexec atomically |
| if cfg!(target_os = "linux") { |
| match cvt(libc::socketpair(fam, ty | SOCK_CLOEXEC, 0, fds.as_mut_ptr())) { |
| Ok(_) => { |
| return Ok((Socket(FileDesc::new(fds[0])), Socket(FileDesc::new(fds[1])))); |
| } |
| Err(ref e) if e.raw_os_error() == Some(libc::EINVAL) => {}, |
| Err(e) => return Err(e), |
| } |
| } |
| |
| cvt(libc::socketpair(fam, ty, 0, fds.as_mut_ptr()))?; |
| let a = FileDesc::new(fds[0]); |
| let b = FileDesc::new(fds[1]); |
| a.set_cloexec()?; |
| b.set_cloexec()?; |
| Ok((Socket(a), Socket(b))) |
| } |
| } |
| |
| 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_value() 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> { |
| // Unfortunately the only known way right now to accept a socket and |
| // atomically set the CLOEXEC flag is to use the `accept4` syscall on |
| // Linux. This was added in 2.6.28, however, and because we support |
| // 2.6.18 we must detect this support dynamically. |
| if cfg!(target_os = "linux") { |
| syscall! { |
| fn accept4( |
| fd: c_int, |
| addr: *mut sockaddr, |
| addr_len: *mut socklen_t, |
| flags: c_int |
| ) -> c_int |
| } |
| let res = cvt_r(|| unsafe { |
| accept4(self.0.raw(), storage, len, SOCK_CLOEXEC) |
| }); |
| match res { |
| Ok(fd) => return Ok(Socket(FileDesc::new(fd))), |
| Err(ref e) if e.raw_os_error() == Some(libc::ENOSYS) => {} |
| Err(e) => return Err(e), |
| } |
| } |
| |
| 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 [IoVecMut<'_>]) -> io::Result<usize> { |
| self.0.read_vectored(bufs) |
| } |
| |
| 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: &[IoVec<'_>]) -> io::Result<usize> { |
| self.0.write_vectored(bufs) |
| } |
| |
| 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_value() as u64 { |
| libc::time_t::max_value() |
| } 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(|_| ()) |
| } |
| |
| 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() {} |
