diff options
Diffstat (limited to 'library/std/src/sys/unix/net.rs')
| -rw-r--r-- | library/std/src/sys/unix/net.rs | 382 |
1 files changed, 382 insertions, 0 deletions
diff --git a/library/std/src/sys/unix/net.rs b/library/std/src/sys/unix/net.rs new file mode 100644 index 00000000000..011325fddc5 --- /dev/null +++ b/library/std/src/sys/unix/net.rs @@ -0,0 +1,382 @@ +use crate::cmp; +use crate::ffi::CStr; +use crate::io::{self, 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::{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 { + cfg_if::cfg_if! { + if #[cfg(target_os = "linux")] { + // On Linux we pass the SOCK_CLOEXEC flag to atomically create + // the socket and set it as CLOEXEC, added in 2.6.27. + let fd = cvt(libc::socket(fam, ty | libc::SOCK_CLOEXEC, 0))?; + Ok(Socket(FileDesc::new(fd))) + } else { + let fd = cvt(libc::socket(fam, ty, 0))?; + let fd = FileDesc::new(fd); + fd.set_cloexec()?; + let socket = Socket(fd); + + // macOS and iOS use `SO_NOSIGPIPE` as a `setsockopt` + // flag to disable `SIGPIPE` emission on socket. + #[cfg(target_vendor = "apple")] + setsockopt(&socket, libc::SOL_SOCKET, libc::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]; + + cfg_if::cfg_if! { + if #[cfg(target_os = "linux")] { + // Like above, set cloexec atomically + cvt(libc::socketpair(fam, ty | libc::SOCK_CLOEXEC, 0, fds.as_mut_ptr()))?; + Ok((Socket(FileDesc::new(fds[0])), Socket(FileDesc::new(fds[1])))) + } else { + 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 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, glibc 2.10 and musl 0.9.5. + cfg_if::cfg_if! { + if #[cfg(target_os = "linux")] { + let fd = cvt_r(|| unsafe { + libc::accept4(self.0.raw(), storage, len, libc::SOCK_CLOEXEC) + })?; + Ok(Socket(FileDesc::new(fd))) + } else { + 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_micros() 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) + } + + #[cfg(not(any(target_os = "solaris", target_os = "illumos")))] + 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) + } + + #[cfg(any(target_os = "solaris", target_os = "illumos"))] + pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> { + // FIONBIO is inadequate for sockets on illumos/Solaris, so use the + // fcntl(F_[GS]ETFL)-based method provided by FileDesc instead. + self.0.set_nonblocking(nonblocking) + } + + 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() {} |