src/libstd/sys/unix/net.rs

   1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 use prelude::v1::*;
  12
  13 use ffi::CStr;
  14 use io;
  15 use libc::{self, c_int, size_t, sockaddr, socklen_t};
  16 use net::{SocketAddr, Shutdown};
  17 use str;
  18 use sys::fd::FileDesc;
  19 use sys_common::{AsInner, FromInner, IntoInner};
  20 use sys_common::net::{getsockopt, setsockopt};
  21 use time::Duration;
  22
  23 pub use sys::{cvt, cvt_r};
  24 pub extern crate libc as netc;
  25
  26 pub type wrlen_t = size_t;
  27
  28 // See below for the usage of SOCK_CLOEXEC, but this constant is only defined on
  29 // Linux currently (e.g. support doesn't exist on other platforms). In order to
  30 // get name resolution to work and things to compile we just define a dummy
  31 // SOCK_CLOEXEC here for other platforms. Note that the dummy constant isn't
  32 // actually ever used (the blocks below are wrapped in `if cfg!` as well.
  33 #[cfg(target_os = "linux")]
  34 use libc::SOCK_CLOEXEC;
  35 #[cfg(not(target_os = "linux"))]
  36 const SOCK_CLOEXEC: c_int = 0;
  37
  38 pub struct Socket(FileDesc);
  39
  40 pub fn init() {}
  41
  42 pub fn cvt_gai(err: c_int) -> io::Result<()> {
  43     if err == 0 { return Ok(()) }
  44
  45     let detail = unsafe {
  46         str::from_utf8(CStr::from_ptr(libc::gai_strerror(err)).to_bytes()).unwrap()
  47             .to_owned()
  48     };
  49     Err(io::Error::new(io::ErrorKind::Other,
  50                        &format!("failed to lookup address information: {}",
  51                                 detail)[..]))
  52 }
  53
  54 impl Socket {
  55     pub fn new(addr: &SocketAddr, ty: c_int) -> io::Result<Socket> {
  56         let fam = match *addr {
  57             SocketAddr::V4(..) => libc::AF_INET,
  58             SocketAddr::V6(..) => libc::AF_INET6,
  59         };
  60         Socket::new_raw(fam, ty)
  61     }
  62
  63     pub fn new_raw(fam: c_int, ty: c_int) -> io::Result<Socket> {
  64         unsafe {
  65             // On linux we first attempt to pass the SOCK_CLOEXEC flag to
  66             // atomically create the socket and set it as CLOEXEC. Support for
  67             // this option, however, was added in 2.6.27, and we still support
  68             // 2.6.18 as a kernel, so if the returned error is EINVAL we
  69             // fallthrough to the fallback.
  70             if cfg!(linux) {
  71                 match cvt(libc::socket(fam, ty | SOCK_CLOEXEC, 0)) {
  72                     Ok(fd) => return Ok(Socket(FileDesc::new(fd))),
  73                     Err(ref e) if e.raw_os_error() == Some(libc::EINVAL) => {}
  74                     Err(e) => return Err(e),
  75                 }
  76             }
  77
  78             let fd = cvt(libc::socket(fam, ty, 0))?;
  79             let fd = FileDesc::new(fd);
  80             fd.set_cloexec();
  81             Ok(Socket(fd))
  82         }
  83     }
  84
  85     pub fn new_pair(fam: c_int, ty: c_int) -> io::Result<(Socket, Socket)> {
  86         unsafe {
  87             let mut fds = [0, 0];
  88
  89             // Like above, see if we can set cloexec atomically
  90             if cfg!(linux) {
  91                 match cvt(libc::socketpair(fam, ty | SOCK_CLOEXEC, 0, fds.as_mut_ptr())) {
  92                     Ok(_) => {
  93                         return Ok((Socket(FileDesc::new(fds[0])), Socket(FileDesc::new(fds[1]))));
  94                     }
  95                     Err(ref e) if e.raw_os_error() == Some(libc::EINVAL) => {},
  96                     Err(e) => return Err(e),
  97                 }
  98             }
  99
 100             cvt(libc::socketpair(fam, ty, 0, fds.as_mut_ptr()))?;
 101             let a = FileDesc::new(fds[0]);
 102             a.set_cloexec();
 103             let b = FileDesc::new(fds[1]);
 104             b.set_cloexec();
 105             Ok((Socket(a), Socket(b)))
 106         }
 107     }
 108
 109     pub fn accept(&self, storage: *mut sockaddr, len: *mut socklen_t)
 110                   -> io::Result<Socket> {
 111         // Unfortunately the only known way right now to accept a socket and
 112         // atomically set the CLOEXEC flag is to use the `accept4` syscall on
 113         // Linux. This was added in 2.6.28, however, and because we support
 114         // 2.6.18 we must detect this support dynamically.
 115         if cfg!(target_os = "linux") {
 116             weak! {
 117                 fn accept4(c_int, *mut sockaddr, *mut socklen_t, c_int) -> c_int
 118             }
 119             if let Some(accept) = accept4.get() {
 120                 let res = cvt_r(|| unsafe {
 121                     accept(self.0.raw(), storage, len, SOCK_CLOEXEC)
 122                 });
 123                 match res {
 124                     Ok(fd) => return Ok(Socket(FileDesc::new(fd))),
 125                     Err(ref e) if e.raw_os_error() == Some(libc::ENOSYS) => {}
 126                     Err(e) => return Err(e),
 127                 }
 128             }
 129         }
 130
 131         let fd = cvt_r(|| unsafe {
 132             libc::accept(self.0.raw(), storage, len)
 133         })?;
 134         let fd = FileDesc::new(fd);
 135         fd.set_cloexec();
 136         Ok(Socket(fd))
 137     }
 138
 139     pub fn duplicate(&self) -> io::Result<Socket> {
 140         self.0.duplicate().map(Socket)
 141     }
 142
 143     pub fn read(&self, buf: &mut [u8]) -> io::Result<usize> {
 144         self.0.read(buf)
 145     }
 146
 147     pub fn read_to_end(&self, buf: &mut Vec<u8>) -> io::Result<usize> {
 148         self.0.read_to_end(buf)
 149     }
 150
 151     pub fn write(&self, buf: &[u8]) -> io::Result<usize> {
 152         self.0.write(buf)
 153     }
 154
 155     pub fn set_timeout(&self, dur: Option<Duration>, kind: libc::c_int) -> io::Result<()> {
 156         let timeout = match dur {
 157             Some(dur) => {
 158                 if dur.as_secs() == 0 && dur.subsec_nanos() == 0 {
 159                     return Err(io::Error::new(io::ErrorKind::InvalidInput,
 160                                               "cannot set a 0 duration timeout"));
 161                 }
 162
 163                 let secs = if dur.as_secs() > libc::time_t::max_value() as u64 {
 164                     libc::time_t::max_value()
 165                 } else {
 166                     dur.as_secs() as libc::time_t
 167                 };
 168                 let mut timeout = libc::timeval {
 169                     tv_sec: secs,
 170                     tv_usec: (dur.subsec_nanos() / 1000) as libc::suseconds_t,
 171                 };
 172                 if timeout.tv_sec == 0 && timeout.tv_usec == 0 {
 173                     timeout.tv_usec = 1;
 174                 }
 175                 timeout
 176             }
 177             None => {
 178                 libc::timeval {
 179                     tv_sec: 0,
 180                     tv_usec: 0,
 181                 }
 182             }
 183         };
 184         setsockopt(self, libc::SOL_SOCKET, kind, timeout)
 185     }
 186
 187     pub fn timeout(&self, kind: libc::c_int) -> io::Result<Option<Duration>> {
 188         let raw: libc::timeval = getsockopt(self, libc::SOL_SOCKET, kind)?;
 189         if raw.tv_sec == 0 && raw.tv_usec == 0 {
 190             Ok(None)
 191         } else {
 192             let sec = raw.tv_sec as u64;
 193             let nsec = (raw.tv_usec as u32) * 1000;
 194             Ok(Some(Duration::new(sec, nsec)))
 195         }
 196     }
 197
 198     pub fn shutdown(&self, how: Shutdown) -> io::Result<()> {
 199         let how = match how {
 200             Shutdown::Write => libc::SHUT_WR,
 201             Shutdown::Read => libc::SHUT_RD,
 202             Shutdown::Both => libc::SHUT_RDWR,
 203         };
 204         cvt(unsafe { libc::shutdown(self.0.raw(), how) })?;
 205         Ok(())
 206     }
 207
 208     pub fn set_nodelay(&self, nodelay: bool) -> io::Result<()> {
 209         setsockopt(self, libc::IPPROTO_TCP, libc::TCP_NODELAY, nodelay as c_int)
 210     }
 211
 212     pub fn nodelay(&self) -> io::Result<bool> {
 213         let raw: c_int = getsockopt(self, libc::IPPROTO_TCP, libc::TCP_NODELAY)?;
 214         Ok(raw != 0)
 215     }
 216
 217     pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
 218         let mut nonblocking = nonblocking as libc::c_ulong;
 219         cvt(unsafe { libc::ioctl(*self.as_inner(), libc::FIONBIO, &mut nonblocking) }).map(|_| ())
 220     }
 221
 222     pub fn take_error(&self) -> io::Result<Option<io::Error>> {
 223         let raw: c_int = getsockopt(self, libc::SOL_SOCKET, libc::SO_ERROR)?;
 224         if raw == 0 {
 225             Ok(None)
 226         } else {
 227             Ok(Some(io::Error::from_raw_os_error(raw as i32)))
 228         }
 229     }
 230 }
 231
 232 impl AsInner<c_int> for Socket {
 233     fn as_inner(&self) -> &c_int { self.0.as_inner() }
 234 }
 235
 236 impl FromInner<c_int> for Socket {
 237     fn from_inner(fd: c_int) -> Socket { Socket(FileDesc::new(fd)) }
 238 }
 239
 240 impl IntoInner<c_int> for Socket {
 241     fn into_inner(self) -> c_int { self.0.into_raw() }
 242 }