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//! Socket interface functions //! //! [Further reading](http://man7.org/linux/man-pages/man7/socket.7.html) use {Error, Result}; use errno::Errno; use libc::{self, c_void, c_int, socklen_t, size_t}; use std::{fmt, mem, ptr, slice}; use std::os::unix::io::RawFd; use sys::time::TimeVal; use sys::uio::IoVec; mod addr; pub mod sockopt; /* * * ===== Re-exports ===== * */ pub use self::addr::{ AddressFamily, SockAddr, InetAddr, UnixAddr, IpAddr, Ipv4Addr, Ipv6Addr, LinkAddr, }; #[cfg(any(target_os = "android", target_os = "linux"))] pub use ::sys::socket::addr::netlink::NetlinkAddr; pub use libc::{ cmsghdr, msghdr, sa_family_t, sockaddr, sockaddr_in, sockaddr_in6, sockaddr_storage, sockaddr_un, }; /// These constants are used to specify the communication semantics /// when creating a socket with [`socket()`](fn.socket.html) #[derive(Clone, Copy, PartialEq, Eq, Debug)] #[repr(i32)] pub enum SockType { /// Provides sequenced, reliable, two-way, connection- /// based byte streams. An out-of-band data transmission /// mechanism may be supported. Stream = libc::SOCK_STREAM, /// Supports datagrams (connectionless, unreliable /// messages of a fixed maximum length). Datagram = libc::SOCK_DGRAM, /// Provides a sequenced, reliable, two-way connection- /// based data transmission path for datagrams of fixed /// maximum length; a consumer is required to read an /// entire packet with each input system call. SeqPacket = libc::SOCK_SEQPACKET, /// Provides raw network protocol access. Raw = libc::SOCK_RAW, /// Provides a reliable datagram layer that does not /// guarantee ordering. Rdm = libc::SOCK_RDM, } /// Constants used in [`socket`](fn.socket.html) and [`socketpair`](fn.socketpair.html) /// to specify the protocol to use. #[repr(i32)] #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)] pub enum SockProtocol { /// TCP protocol ([ip(7)](http://man7.org/linux/man-pages/man7/ip.7.html)) Tcp = libc::IPPROTO_TCP, /// UDP protocol ([ip(7)](http://man7.org/linux/man-pages/man7/ip.7.html)) Udp = libc::IPPROTO_UDP, /// Allows applications and other KEXTs to be notified when certain kernel events occur /// ([ref](https://developer.apple.com/library/content/documentation/Darwin/Conceptual/NKEConceptual/control/control.html)) #[cfg(any(target_os = "ios", target_os = "macos"))] KextEvent = libc::SYSPROTO_EVENT, /// Allows applications to configure and control a KEXT /// ([ref](https://developer.apple.com/library/content/documentation/Darwin/Conceptual/NKEConceptual/control/control.html)) #[cfg(any(target_os = "ios", target_os = "macos"))] KextControl = libc::SYSPROTO_CONTROL, } libc_bitflags!{ /// Additional socket options pub struct SockFlag: c_int { /// Set non-blocking mode on the new socket #[cfg(any(target_os = "android", target_os = "dragonfly", target_os = "freebsd", target_os = "linux", target_os = "netbsd", target_os = "openbsd"))] SOCK_NONBLOCK; /// Set close-on-exec on the new descriptor #[cfg(any(target_os = "android", target_os = "dragonfly", target_os = "freebsd", target_os = "linux", target_os = "netbsd", target_os = "openbsd"))] SOCK_CLOEXEC; /// Return `EPIPE` instead of raising `SIGPIPE` #[cfg(target_os = "netbsd")] SOCK_NOSIGPIPE; /// For domains `AF_INET(6)`, only allow `connect(2)`, `sendto(2)`, or `sendmsg(2)` /// to the DNS port (typically 53) #[cfg(target_os = "openbsd")] SOCK_DNS; } } libc_bitflags!{ /// Flags for send/recv and their relatives pub struct MsgFlags: c_int { /// Sends or requests out-of-band data on sockets that support this notion /// (e.g., of type [`Stream`](enum.SockType.html)); the underlying protocol must also /// support out-of-band data. MSG_OOB; /// Peeks at an incoming message. The data is treated as unread and the next /// [`recv()`](fn.recv.html) /// or similar function shall still return this data. MSG_PEEK; /// Enables nonblocking operation; if the operation would block, /// `EAGAIN` or `EWOULDBLOCK` is returned. This provides similar /// behavior to setting the `O_NONBLOCK` flag /// (via the [`fcntl`](../../fcntl/fn.fcntl.html) /// `F_SETFL` operation), but differs in that `MSG_DONTWAIT` is a per- /// call option, whereas `O_NONBLOCK` is a setting on the open file /// description (see [open(2)](http://man7.org/linux/man-pages/man2/open.2.html)), /// which will affect all threads in /// the calling process and as well as other processes that hold /// file descriptors referring to the same open file description. MSG_DONTWAIT; /// Receive flags: Control Data was discarded (buffer too small) MSG_CTRUNC; /// For raw ([`Packet`](addr/enum.AddressFamily.html)), Internet datagram /// (since Linux 2.4.27/2.6.8), /// netlink (since Linux 2.6.22) and UNIX datagram (since Linux 3.4) /// sockets: return the real length of the packet or datagram, even /// when it was longer than the passed buffer. Not implemented for UNIX /// domain ([unix(7)](https://linux.die.net/man/7/unix)) sockets. /// /// For use with Internet stream sockets, see [tcp(7)](https://linux.die.net/man/7/tcp). MSG_TRUNC; /// Terminates a record (when this notion is supported, as for /// sockets of type [`SeqPacket`](enum.SockType.html)). MSG_EOR; /// This flag specifies that queued errors should be received from /// the socket error queue. (For more details, see /// [recvfrom(2)](https://linux.die.net/man/2/recvfrom)) #[cfg(any(target_os = "android", target_os = "linux"))] MSG_ERRQUEUE; /// Set the `close-on-exec` flag for the file descriptor received via a UNIX domain /// file descriptor using the `SCM_RIGHTS` operation (described in /// [unix(7)](https://linux.die.net/man/7/unix)). /// This flag is useful for the same reasons as the `O_CLOEXEC` flag of /// [open(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/open.html). /// /// Only used in [`recvmsg`](fn.recvmsg.html) function. #[cfg(any(target_os = "android", target_os = "dragonfly", target_os = "freebsd", target_os = "linux", target_os = "netbsd", target_os = "openbsd"))] MSG_CMSG_CLOEXEC; } } cfg_if! { if #[cfg(any(target_os = "android", target_os = "linux"))] { /// Unix credentials of the sending process. /// /// This struct is used with the `SO_PEERCRED` ancillary message for UNIX sockets. #[repr(C)] #[derive(Clone, Copy)] pub struct UnixCredentials(libc::ucred); impl UnixCredentials { /// Returns the process identifier pub fn pid(&self) -> libc::pid_t { self.0.pid } /// Returns the user identifier pub fn uid(&self) -> libc::uid_t { self.0.uid } /// Returns the group identifier pub fn gid(&self) -> libc::gid_t { self.0.gid } } impl PartialEq for UnixCredentials { fn eq(&self, other: &Self) -> bool { self.0.pid == other.0.pid && self.0.uid == other.0.uid && self.0.gid == other.0.gid } } impl Eq for UnixCredentials {} impl From<libc::ucred> for UnixCredentials { fn from(cred: libc::ucred) -> Self { UnixCredentials(cred) } } impl Into<libc::ucred> for UnixCredentials { fn into(self) -> libc::ucred { self.0 } } impl fmt::Debug for UnixCredentials { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { f.debug_struct("UnixCredentials") .field("pid", &self.0.pid) .field("uid", &self.0.uid) .field("gid", &self.0.gid) .finish() } } } } /// Request for multicast socket operations /// /// This is a wrapper type around `ip_mreq`. #[repr(C)] #[derive(Clone, Copy)] pub struct IpMembershipRequest(libc::ip_mreq); impl IpMembershipRequest { /// Instantiate a new `IpMembershipRequest` /// /// If `interface` is `None`, then `Ipv4Addr::any()` will be used for the interface. pub fn new(group: Ipv4Addr, interface: Option<Ipv4Addr>) -> Self { IpMembershipRequest(libc::ip_mreq { imr_multiaddr: group.0, imr_interface: interface.unwrap_or_else(Ipv4Addr::any).0, }) } } impl PartialEq for IpMembershipRequest { fn eq(&self, other: &Self) -> bool { self.0.imr_multiaddr.s_addr == other.0.imr_multiaddr.s_addr && self.0.imr_interface.s_addr == other.0.imr_interface.s_addr } } impl Eq for IpMembershipRequest {} impl fmt::Debug for IpMembershipRequest { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { let mref = &self.0.imr_multiaddr; let maddr = mref.s_addr; let iref = &self.0.imr_interface; let ifaddr = iref.s_addr; f.debug_struct("IpMembershipRequest") .field("imr_multiaddr", &maddr) .field("imr_interface", &ifaddr) .finish() } } /// Request for ipv6 multicast socket operations /// /// This is a wrapper type around `ipv6_mreq`. #[repr(C)] #[derive(Clone, Copy)] pub struct Ipv6MembershipRequest(libc::ipv6_mreq); impl Ipv6MembershipRequest { /// Instantiate a new `Ipv6MembershipRequest` pub fn new(group: Ipv6Addr) -> Self { Ipv6MembershipRequest(libc::ipv6_mreq { ipv6mr_multiaddr: group.0, ipv6mr_interface: 0, }) } } impl PartialEq for Ipv6MembershipRequest { fn eq(&self, other: &Self) -> bool { self.0.ipv6mr_multiaddr.s6_addr == other.0.ipv6mr_multiaddr.s6_addr && self.0.ipv6mr_interface == other.0.ipv6mr_interface } } impl Eq for Ipv6MembershipRequest {} impl fmt::Debug for Ipv6MembershipRequest { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { f.debug_struct("Ipv6MembershipRequest") .field("ipv6mr_multiaddr", &self.0.ipv6mr_multiaddr.s6_addr) .field("ipv6mr_interface", &self.0.ipv6mr_interface) .finish() } } /// Copy the in-memory representation of `src` into the byte slice `dst`. /// /// Returns the remainder of `dst`. /// /// Panics when `dst` is too small for `src` (more precisely, panics if /// `mem::size_of_val(src) >= dst.len()`). /// /// Unsafe because it transmutes `src` to raw bytes, which is only safe for some /// types `T`. Refer to the [Rustonomicon] for details. /// /// [Rustonomicon]: https://doc.rust-lang.org/nomicon/transmutes.html unsafe fn copy_bytes<'a, T: ?Sized>(src: &T, dst: &'a mut [u8]) -> &'a mut [u8] { let srclen = mem::size_of_val(src); ptr::copy_nonoverlapping( src as *const T as *const u8, dst[..srclen].as_mut_ptr(), srclen ); &mut dst[srclen..] } /// Fills `dst` with `len` zero bytes and returns the remainder of the slice. /// /// Panics when `len >= dst.len()`. fn pad_bytes(len: usize, dst: &mut [u8]) -> &mut [u8] { for pad in &mut dst[..len] { *pad = 0; } &mut dst[len..] } cfg_if! { // Darwin and DragonFly BSD always align struct cmsghdr to 32-bit only. if #[cfg(any(target_os = "dragonfly", target_os = "ios", target_os = "macos"))] { type align_of_cmsg_data = u32; } else { type align_of_cmsg_data = size_t; } } /// A structure used to make room in a cmsghdr passed to recvmsg. The /// size and alignment match that of a cmsghdr followed by a T, but the /// fields are not accessible, as the actual types will change on a call /// to recvmsg. /// /// To make room for multiple messages, nest the type parameter with /// tuples: /// /// ``` /// use std::os::unix::io::RawFd; /// use nix::sys::socket::CmsgSpace; /// let cmsg: CmsgSpace<([RawFd; 3], CmsgSpace<[RawFd; 2]>)> = CmsgSpace::new(); /// ``` #[repr(C)] #[allow(missing_debug_implementations)] pub struct CmsgSpace<T> { _hdr: cmsghdr, _pad: [align_of_cmsg_data; 0], _data: T, } impl<T> CmsgSpace<T> { /// Create a CmsgSpace<T>. The structure is used only for space, so /// the fields are uninitialized. pub fn new() -> Self { // Safe because the fields themselves aren't accessible. unsafe { mem::uninitialized() } } } #[derive(Debug)] pub struct RecvMsg<'a> { // The number of bytes received. pub bytes: usize, cmsg_buffer: &'a [u8], pub address: Option<SockAddr>, pub flags: MsgFlags, } impl<'a> RecvMsg<'a> { /// Iterate over the valid control messages pointed to by this /// msghdr. pub fn cmsgs(&self) -> CmsgIterator { CmsgIterator { buf: self.cmsg_buffer, } } } #[derive(Debug)] pub struct CmsgIterator<'a> { /// Control message buffer to decode from. Must adhere to cmsg alignment. buf: &'a [u8], } impl<'a> Iterator for CmsgIterator<'a> { type Item = ControlMessage<'a>; // The implementation loosely follows CMSG_FIRSTHDR / CMSG_NXTHDR, // although we handle the invariants in slightly different places to // get a better iterator interface. fn next(&mut self) -> Option<ControlMessage<'a>> { if self.buf.len() == 0 { // The iterator assumes that `self.buf` always contains exactly the // bytes we need, so we're at the end when the buffer is empty. return None; } // Safe if: `self.buf` is `cmsghdr`-aligned. let cmsg: &'a cmsghdr = unsafe { &*(self.buf[..mem::size_of::<cmsghdr>()].as_ptr() as *const cmsghdr) }; let cmsg_len = cmsg.cmsg_len as usize; // Advance our internal pointer. let cmsg_data = &self.buf[cmsg_align(mem::size_of::<cmsghdr>())..cmsg_len]; self.buf = &self.buf[cmsg_align(cmsg_len)..]; // Safe if: `cmsg_data` contains the expected (amount of) content. This // is verified by the kernel. unsafe { Some(ControlMessage::decode_from(cmsg, cmsg_data)) } } } /// A type-safe wrapper around a single control message. More types may /// be added to this enum; do not exhaustively pattern-match it. /// [Further reading](http://man7.org/linux/man-pages/man3/cmsg.3.html) #[allow(missing_debug_implementations)] pub enum ControlMessage<'a> { /// A message of type `SCM_RIGHTS`, containing an array of file /// descriptors passed between processes. /// /// See the description in the "Ancillary messages" section of the /// [unix(7) man page](http://man7.org/linux/man-pages/man7/unix.7.html). /// /// Using multiple `ScmRights` messages for a single `sendmsg` call isn't recommended since it /// causes platform-dependent behaviour: It might swallow all but the first `ScmRights` message /// or fail with `EINVAL`. Instead, you can put all fds to be passed into a single `ScmRights` /// message. ScmRights(&'a [RawFd]), /// A message of type `SCM_CREDENTIALS`, containing the pid, uid and gid of /// a process connected to the socket. /// /// This is similar to the socket option `SO_PEERCRED`, but requires a /// process to explicitly send its credentials. A process running as root is /// allowed to specify any credentials, while credentials sent by other /// processes are verified by the kernel. /// /// For further information, please refer to the /// [`unix(7)`](http://man7.org/linux/man-pages/man7/unix.7.html) man page. // FIXME: When `#[repr(transparent)]` is stable, use it on `UnixCredentials` // and put that in here instead of a raw ucred. #[cfg(any(target_os = "android", target_os = "linux"))] ScmCredentials(&'a libc::ucred), /// A message of type `SCM_TIMESTAMP`, containing the time the /// packet was received by the kernel. /// /// See the kernel's explanation in "SO_TIMESTAMP" of /// [networking/timestamping](https://www.kernel.org/doc/Documentation/networking/timestamping.txt). /// /// # Examples /// // Disable this test on FreeBSD i386 // https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=222039 #[cfg_attr(not(all(target_os = "freebsd", target_arch = "x86")), doc = " ```")] #[cfg_attr(all(target_os = "freebsd", target_arch = "x86"), doc = " ```no_run")] /// use nix::sys::socket::*; /// use nix::sys::uio::IoVec; /// use nix::sys::time::*; /// use std::time::*; /// /// // Set up /// let message = "Ohayō!".as_bytes(); /// let in_socket = socket( /// AddressFamily::Inet, /// SockType::Datagram, /// SockFlag::empty(), /// None).unwrap(); /// setsockopt(in_socket, sockopt::ReceiveTimestamp, &true).unwrap(); /// let localhost = InetAddr::new(IpAddr::new_v4(127, 0, 0, 1), 0); /// bind(in_socket, &SockAddr::new_inet(localhost)).unwrap(); /// let address = getsockname(in_socket).unwrap(); /// // Get initial time /// let time0 = SystemTime::now(); /// // Send the message /// let iov = [IoVec::from_slice(message)]; /// let flags = MsgFlags::empty(); /// let l = sendmsg(in_socket, &iov, &[], flags, Some(&address)).unwrap(); /// assert_eq!(message.len(), l); /// // Receive the message /// let mut buffer = vec![0u8; message.len()]; /// let mut cmsgspace: CmsgSpace<TimeVal> = CmsgSpace::new(); /// let iov = [IoVec::from_mut_slice(&mut buffer)]; /// let r = recvmsg(in_socket, &iov, Some(&mut cmsgspace), flags).unwrap(); /// let rtime = match r.cmsgs().next() { /// Some(ControlMessage::ScmTimestamp(&rtime)) => rtime, /// Some(_) => panic!("Unexpected control message"), /// None => panic!("No control message") /// }; /// // Check the final time /// let time1 = SystemTime::now(); /// // the packet's received timestamp should lie in-between the two system /// // times, unless the system clock was adjusted in the meantime. /// let rduration = Duration::new(rtime.tv_sec() as u64, /// rtime.tv_usec() as u32 * 1000); /// assert!(time0.duration_since(UNIX_EPOCH).unwrap() <= rduration); /// assert!(rduration <= time1.duration_since(UNIX_EPOCH).unwrap()); /// // Close socket /// nix::unistd::close(in_socket).unwrap(); /// ``` ScmTimestamp(&'a TimeVal), #[cfg(any( target_os = "android", target_os = "ios", target_os = "linux", target_os = "macos" ))] Ipv4PacketInfo(&'a libc::in_pktinfo), #[cfg(any( target_os = "android", target_os = "freebsd", target_os = "ios", target_os = "linux", target_os = "macos" ))] Ipv6PacketInfo(&'a libc::in6_pktinfo), /// Catch-all variant for unimplemented cmsg types. #[doc(hidden)] Unknown(UnknownCmsg<'a>), } // An opaque structure used to prevent cmsghdr from being a public type #[doc(hidden)] #[allow(missing_debug_implementations)] pub struct UnknownCmsg<'a>(&'a cmsghdr, &'a [u8]); // Round `len` up to meet the platform's required alignment for // `cmsghdr`s and trailing `cmsghdr` data. This should match the // behaviour of CMSG_ALIGN from the Linux headers and do the correct // thing on other platforms that don't usually provide CMSG_ALIGN. #[inline] fn cmsg_align(len: usize) -> usize { let align_bytes = mem::size_of::<align_of_cmsg_data>() - 1; (len + align_bytes) & !align_bytes } impl<'a> ControlMessage<'a> { /// The value of CMSG_SPACE on this message. fn space(&self) -> usize { cmsg_align(self.len()) } /// The value of CMSG_LEN on this message. fn len(&self) -> usize { cmsg_align(mem::size_of::<cmsghdr>()) + match *self { ControlMessage::ScmRights(fds) => { mem::size_of_val(fds) }, #[cfg(any(target_os = "android", target_os = "linux"))] ControlMessage::ScmCredentials(creds) => { mem::size_of_val(creds) } ControlMessage::ScmTimestamp(t) => { mem::size_of_val(t) }, #[cfg(any( target_os = "android", target_os = "ios", target_os = "linux", target_os = "macos" ))] ControlMessage::Ipv4PacketInfo(pktinfo) => { mem::size_of_val(pktinfo) }, #[cfg(any( target_os = "android", target_os = "freebsd", target_os = "ios", target_os = "linux", target_os = "macos" ))] ControlMessage::Ipv6PacketInfo(pktinfo) => { mem::size_of_val(pktinfo) }, ControlMessage::Unknown(UnknownCmsg(_, bytes)) => { mem::size_of_val(bytes) } } } /// Returns the value to put into the `cmsg_level` field of the header. fn cmsg_level(&self) -> libc::c_int { match *self { ControlMessage::ScmRights(_) => libc::SOL_SOCKET, #[cfg(any(target_os = "android", target_os = "linux"))] ControlMessage::ScmCredentials(_) => libc::SOL_SOCKET, ControlMessage::ScmTimestamp(_) => libc::SOL_SOCKET, #[cfg(any( target_os = "android", target_os = "ios", target_os = "linux", target_os = "macos" ))] ControlMessage::Ipv4PacketInfo(_) => libc::IPPROTO_IP, #[cfg(any( target_os = "android", target_os = "freebsd", target_os = "ios", target_os = "linux", target_os = "macos" ))] ControlMessage::Ipv6PacketInfo(_) => libc::IPPROTO_IPV6, ControlMessage::Unknown(ref cmsg) => cmsg.0.cmsg_level, } } /// Returns the value to put into the `cmsg_type` field of the header. fn cmsg_type(&self) -> libc::c_int { match *self { ControlMessage::ScmRights(_) => libc::SCM_RIGHTS, #[cfg(any(target_os = "android", target_os = "linux"))] ControlMessage::ScmCredentials(_) => libc::SCM_CREDENTIALS, ControlMessage::ScmTimestamp(_) => libc::SCM_TIMESTAMP, #[cfg(any( target_os = "android", target_os = "ios", target_os = "linux", target_os = "macos" ))] ControlMessage::Ipv4PacketInfo(_) => libc::IP_PKTINFO, #[cfg(any( target_os = "android", target_os = "freebsd", target_os = "ios", target_os = "linux", target_os = "macos" ))] ControlMessage::Ipv6PacketInfo(_) => libc::IPV6_PKTINFO, ControlMessage::Unknown(ref cmsg) => cmsg.0.cmsg_type, } } // Unsafe: start and end of buffer must be cmsg_align'd. Updates // the provided slice; panics if the buffer is too small. unsafe fn encode_into(&self, buf: &mut [u8]) { let final_buf = if let ControlMessage::Unknown(ref cmsg) = *self { let &UnknownCmsg(orig_cmsg, bytes) = cmsg; let buf = copy_bytes(orig_cmsg, buf); let padlen = cmsg_align(mem::size_of_val(&orig_cmsg)) - mem::size_of_val(&orig_cmsg); let buf = pad_bytes(padlen, buf); copy_bytes(bytes, buf) } else { let cmsg = cmsghdr { cmsg_len: self.len() as _, cmsg_level: self.cmsg_level(), cmsg_type: self.cmsg_type(), ..mem::zeroed() // zero out platform-dependent padding fields }; let buf = copy_bytes(&cmsg, buf); let padlen = cmsg_align(mem::size_of_val(&cmsg)) - mem::size_of_val(&cmsg); let buf = pad_bytes(padlen, buf); match *self { ControlMessage::ScmRights(fds) => { copy_bytes(fds, buf) }, #[cfg(any(target_os = "android", target_os = "linux"))] ControlMessage::ScmCredentials(creds) => { copy_bytes(creds, buf) }, ControlMessage::ScmTimestamp(t) => { copy_bytes(t, buf) }, #[cfg(any( target_os = "android", target_os = "ios", target_os = "linux", target_os = "macos" ))] ControlMessage::Ipv4PacketInfo(pktinfo) => { copy_bytes(pktinfo, buf) }, #[cfg(any( target_os = "android", target_os = "freebsd", target_os = "ios", target_os = "linux", target_os = "macos" ))] ControlMessage::Ipv6PacketInfo(pktinfo) => { copy_bytes(pktinfo, buf) } ControlMessage::Unknown(_) => unreachable!(), } }; let padlen = self.space() - self.len(); pad_bytes(padlen, final_buf); } /// Decodes a `ControlMessage` from raw bytes. /// /// This is only safe to call if the data is correct for the message type /// specified in the header. Normally, the kernel ensures that this is the /// case. "Correct" in this case includes correct length, alignment and /// actual content. unsafe fn decode_from(header: &'a cmsghdr, data: &'a [u8]) -> ControlMessage<'a> { match (header.cmsg_level, header.cmsg_type) { (libc::SOL_SOCKET, libc::SCM_RIGHTS) => { ControlMessage::ScmRights( slice::from_raw_parts(data.as_ptr() as *const _, data.len() / mem::size_of::<RawFd>())) }, #[cfg(any(target_os = "android", target_os = "linux"))] (libc::SOL_SOCKET, libc::SCM_CREDENTIALS) => { ControlMessage::ScmCredentials( &*(data.as_ptr() as *const _) ) } (libc::SOL_SOCKET, libc::SCM_TIMESTAMP) => { ControlMessage::ScmTimestamp( &*(data.as_ptr() as *const _)) }, #[cfg(any( target_os = "android", target_os = "freebsd", target_os = "ios", target_os = "linux", target_os = "macos" ))] (libc::IPPROTO_IPV6, libc::IPV6_PKTINFO) => { ControlMessage::Ipv6PacketInfo( &*(data.as_ptr() as *const _)) } #[cfg(any( target_os = "android", target_os = "ios", target_os = "linux", target_os = "macos" ))] (libc::IPPROTO_IP, libc::IP_PKTINFO) => { ControlMessage::Ipv4PacketInfo( &*(data.as_ptr() as *const _)) } (_, _) => { ControlMessage::Unknown(UnknownCmsg(header, data)) } } } } /// Send data in scatter-gather vectors to a socket, possibly accompanied /// by ancillary data. Optionally direct the message at the given address, /// as with sendto. /// /// Allocates if cmsgs is nonempty. pub fn sendmsg<'a>(fd: RawFd, iov: &[IoVec<&'a [u8]>], cmsgs: &[ControlMessage<'a>], flags: MsgFlags, addr: Option<&'a SockAddr>) -> Result<usize> { let mut capacity = 0; for cmsg in cmsgs { capacity += cmsg.space(); } // Note that the resulting vector claims to have length == capacity, // so it's presently uninitialized. let mut cmsg_buffer = unsafe { let mut vec = Vec::<u8>::with_capacity(capacity); vec.set_len(capacity); vec }; { let mut ofs = 0; for cmsg in cmsgs { let ptr = &mut cmsg_buffer[ofs..]; unsafe { cmsg.encode_into(ptr); } ofs += cmsg.space(); } } let (name, namelen) = match addr { Some(addr) => { let (x, y) = unsafe { addr.as_ffi_pair() }; (x as *const _, y) } None => (ptr::null(), 0), }; let cmsg_ptr = if capacity > 0 { cmsg_buffer.as_ptr() as *const c_void } else { ptr::null() }; let mhdr = unsafe { let mut mhdr: msghdr = mem::uninitialized(); mhdr.msg_name = name as *mut _; mhdr.msg_namelen = namelen; mhdr.msg_iov = iov.as_ptr() as *mut _; mhdr.msg_iovlen = iov.len() as _; mhdr.msg_control = cmsg_ptr as *mut _; mhdr.msg_controllen = capacity as _; mhdr.msg_flags = 0; mhdr }; let ret = unsafe { libc::sendmsg(fd, &mhdr, flags.bits()) }; Errno::result(ret).map(|r| r as usize) } /// Receive message in scatter-gather vectors from a socket, and /// optionally receive ancillary data into the provided buffer. /// If no ancillary data is desired, use () as the type parameter. pub fn recvmsg<'a, T>(fd: RawFd, iov: &[IoVec<&mut [u8]>], cmsg_buffer: Option<&'a mut CmsgSpace<T>>, flags: MsgFlags) -> Result<RecvMsg<'a>> { let mut address: sockaddr_storage = unsafe { mem::uninitialized() }; let (msg_control, msg_controllen) = match cmsg_buffer { Some(cmsg_buffer) => (cmsg_buffer as *mut _, mem::size_of_val(cmsg_buffer)), None => (ptr::null_mut(), 0), }; let mut mhdr = unsafe { let mut mhdr: msghdr = mem::uninitialized(); mhdr.msg_name = &mut address as *mut _ as *mut _; mhdr.msg_namelen = mem::size_of::<sockaddr_storage>() as socklen_t; mhdr.msg_iov = iov.as_ptr() as *mut _; mhdr.msg_iovlen = iov.len() as _; mhdr.msg_control = msg_control as *mut _; mhdr.msg_controllen = msg_controllen as _; mhdr.msg_flags = 0; mhdr }; let ret = unsafe { libc::recvmsg(fd, &mut mhdr, flags.bits()) }; let cmsg_buffer = if msg_controllen > 0 { // got control message(s) debug_assert!(!mhdr.msg_control.is_null()); unsafe { // Safe: The pointer is not null and the length is correct as part of `recvmsg`s // contract. slice::from_raw_parts(mhdr.msg_control as *const u8, mhdr.msg_controllen as usize) } } else { // No control message, create an empty buffer to avoid creating a slice from a null pointer &[] }; Ok(unsafe { RecvMsg { bytes: Errno::result(ret)? as usize, cmsg_buffer, address: sockaddr_storage_to_addr(&address, mhdr.msg_namelen as usize).ok(), flags: MsgFlags::from_bits_truncate(mhdr.msg_flags), } }) } /// Create an endpoint for communication /// /// The `protocol` specifies a particular protocol to be used with the /// socket. Normally only a single protocol exists to support a /// particular socket type within a given protocol family, in which case /// protocol can be specified as `None`. However, it is possible that many /// protocols may exist, in which case a particular protocol must be /// specified in this manner. /// /// [Further reading](http://pubs.opengroup.org/onlinepubs/9699919799/functions/socket.html) pub fn socket<T: Into<Option<SockProtocol>>>(domain: AddressFamily, ty: SockType, flags: SockFlag, protocol: T) -> Result<RawFd> { let protocol = match protocol.into() { None => 0, Some(p) => p as c_int, }; // SockFlags are usually embedded into `ty`, but we don't do that in `nix` because it's a // little easier to understand by separating it out. So we have to merge these bitfields // here. let mut ty = ty as c_int; ty |= flags.bits(); let res = unsafe { libc::socket(domain as c_int, ty, protocol) }; Errno::result(res) } /// Create a pair of connected sockets /// /// [Further reading](http://pubs.opengroup.org/onlinepubs/9699919799/functions/socketpair.html) pub fn socketpair<T: Into<Option<SockProtocol>>>(domain: AddressFamily, ty: SockType, protocol: T, flags: SockFlag) -> Result<(RawFd, RawFd)> { let protocol = match protocol.into() { None => 0, Some(p) => p as c_int, }; // SockFlags are usually embedded into `ty`, but we don't do that in `nix` because it's a // little easier to understand by separating it out. So we have to merge these bitfields // here. let mut ty = ty as c_int; ty |= flags.bits(); let mut fds = [-1, -1]; let res = unsafe { libc::socketpair(domain as c_int, ty, protocol, fds.as_mut_ptr()) }; Errno::result(res)?; Ok((fds[0], fds[1])) } /// Listen for connections on a socket /// /// [Further reading](http://pubs.opengroup.org/onlinepubs/9699919799/functions/listen.html) pub fn listen(sockfd: RawFd, backlog: usize) -> Result<()> { let res = unsafe { libc::listen(sockfd, backlog as c_int) }; Errno::result(res).map(drop) } /// Bind a name to a socket /// /// [Further reading](http://pubs.opengroup.org/onlinepubs/9699919799/functions/bind.html) pub fn bind(fd: RawFd, addr: &SockAddr) -> Result<()> { let res = unsafe { let (ptr, len) = addr.as_ffi_pair(); libc::bind(fd, ptr, len) }; Errno::result(res).map(drop) } /// Accept a connection on a socket /// /// [Further reading](http://pubs.opengroup.org/onlinepubs/9699919799/functions/accept.html) pub fn accept(sockfd: RawFd) -> Result<RawFd> { let res = unsafe { libc::accept(sockfd, ptr::null_mut(), ptr::null_mut()) }; Errno::result(res) } /// Accept a connection on a socket /// /// [Further reading](http://man7.org/linux/man-pages/man2/accept.2.html) #[cfg(any(target_os = "android", target_os = "freebsd", target_os = "linux", target_os = "openbsd"))] pub fn accept4(sockfd: RawFd, flags: SockFlag) -> Result<RawFd> { let res = unsafe { libc::accept4(sockfd, ptr::null_mut(), ptr::null_mut(), flags.bits()) }; Errno::result(res) } /// Initiate a connection on a socket /// /// [Further reading](http://pubs.opengroup.org/onlinepubs/9699919799/functions/connect.html) pub fn connect(fd: RawFd, addr: &SockAddr) -> Result<()> { let res = unsafe { let (ptr, len) = addr.as_ffi_pair(); libc::connect(fd, ptr, len) }; Errno::result(res).map(drop) } /// Receive data from a connection-oriented socket. Returns the number of /// bytes read /// /// [Further reading](http://pubs.opengroup.org/onlinepubs/9699919799/functions/recv.html) pub fn recv(sockfd: RawFd, buf: &mut [u8], flags: MsgFlags) -> Result<usize> { unsafe { let ret = libc::recv( sockfd, buf.as_ptr() as *mut c_void, buf.len() as size_t, flags.bits()); Errno::result(ret).map(|r| r as usize) } } /// Receive data from a connectionless or connection-oriented socket. Returns /// the number of bytes read and the socket address of the sender. /// /// [Further reading](http://pubs.opengroup.org/onlinepubs/9699919799/functions/recvfrom.html) pub fn recvfrom(sockfd: RawFd, buf: &mut [u8]) -> Result<(usize, SockAddr)> { unsafe { let addr: sockaddr_storage = mem::zeroed(); let mut len = mem::size_of::<sockaddr_storage>() as socklen_t; let ret = Errno::result(libc::recvfrom( sockfd, buf.as_ptr() as *mut c_void, buf.len() as size_t, 0, mem::transmute(&addr), &mut len as *mut socklen_t))?; sockaddr_storage_to_addr(&addr, len as usize) .map(|addr| (ret as usize, addr)) } } /// Send a message to a socket /// /// [Further reading](http://pubs.opengroup.org/onlinepubs/9699919799/functions/sendto.html) pub fn sendto(fd: RawFd, buf: &[u8], addr: &SockAddr, flags: MsgFlags) -> Result<usize> { let ret = unsafe { let (ptr, len) = addr.as_ffi_pair(); libc::sendto(fd, buf.as_ptr() as *const c_void, buf.len() as size_t, flags.bits(), ptr, len) }; Errno::result(ret).map(|r| r as usize) } /// Send data to a connection-oriented socket. Returns the number of bytes read /// /// [Further reading](http://pubs.opengroup.org/onlinepubs/9699919799/functions/send.html) pub fn send(fd: RawFd, buf: &[u8], flags: MsgFlags) -> Result<usize> { let ret = unsafe { libc::send(fd, buf.as_ptr() as *const c_void, buf.len() as size_t, flags.bits()) }; Errno::result(ret).map(|r| r as usize) } /* * * ===== Socket Options ===== * */ /// The protocol level at which to get / set socket options. Used as an /// argument to `getsockopt` and `setsockopt`. /// /// [Further reading](http://pubs.opengroup.org/onlinepubs/9699919799/functions/setsockopt.html) #[repr(i32)] #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)] pub enum SockLevel { Socket = libc::SOL_SOCKET, Tcp = libc::IPPROTO_TCP, Ip = libc::IPPROTO_IP, Ipv6 = libc::IPPROTO_IPV6, Udp = libc::IPPROTO_UDP, #[cfg(any(target_os = "android", target_os = "linux"))] Netlink = libc::SOL_NETLINK, } /// Represents a socket option that can be accessed or set. Used as an argument /// to `getsockopt` pub trait GetSockOpt : Copy { type Val; #[doc(hidden)] fn get(&self, fd: RawFd) -> Result<Self::Val>; } /// Represents a socket option that can be accessed or set. Used as an argument /// to `setsockopt` pub trait SetSockOpt : Copy { type Val; #[doc(hidden)] fn set(&self, fd: RawFd, val: &Self::Val) -> Result<()>; } /// Get the current value for the requested socket option /// /// [Further reading](http://pubs.opengroup.org/onlinepubs/9699919799/functions/getsockopt.html) pub fn getsockopt<O: GetSockOpt>(fd: RawFd, opt: O) -> Result<O::Val> { opt.get(fd) } /// Sets the value for the requested socket option /// /// [Further reading](http://pubs.opengroup.org/onlinepubs/9699919799/functions/setsockopt.html) /// /// # Examples /// /// ``` /// use nix::sys::socket::setsockopt; /// use nix::sys::socket::sockopt::KeepAlive; /// use std::net::TcpListener; /// use std::os::unix::io::AsRawFd; /// /// let listener = TcpListener::bind("0.0.0.0:0").unwrap(); /// let fd = listener.as_raw_fd(); /// let res = setsockopt(fd, KeepAlive, &true); /// assert!(res.is_ok()); /// ``` pub fn setsockopt<O: SetSockOpt>(fd: RawFd, opt: O, val: &O::Val) -> Result<()> { opt.set(fd, val) } /// Get the address of the peer connected to the socket `fd`. /// /// [Further reading](http://pubs.opengroup.org/onlinepubs/9699919799/functions/getpeername.html) pub fn getpeername(fd: RawFd) -> Result<SockAddr> { unsafe { let addr: sockaddr_storage = mem::uninitialized(); let mut len = mem::size_of::<sockaddr_storage>() as socklen_t; let ret = libc::getpeername(fd, mem::transmute(&addr), &mut len); Errno::result(ret)?; sockaddr_storage_to_addr(&addr, len as usize) } } /// Get the current address to which the socket `fd` is bound. /// /// [Further reading](http://pubs.opengroup.org/onlinepubs/9699919799/functions/getsockname.html) pub fn getsockname(fd: RawFd) -> Result<SockAddr> { unsafe { let addr: sockaddr_storage = mem::uninitialized(); let mut len = mem::size_of::<sockaddr_storage>() as socklen_t; let ret = libc::getsockname(fd, mem::transmute(&addr), &mut len); Errno::result(ret)?; sockaddr_storage_to_addr(&addr, len as usize) } } /// Return the appropriate `SockAddr` type from a `sockaddr_storage` of a certain /// size. In C this would usually be done by casting. The `len` argument /// should be the number of bytes in the `sockaddr_storage` that are actually /// allocated and valid. It must be at least as large as all the useful parts /// of the structure. Note that in the case of a `sockaddr_un`, `len` need not /// include the terminating null. pub unsafe fn sockaddr_storage_to_addr( addr: &sockaddr_storage, len: usize) -> Result<SockAddr> { if len < mem::size_of_val(&addr.ss_family) { return Err(Error::Sys(Errno::ENOTCONN)); } match addr.ss_family as c_int { libc::AF_INET => { assert!(len as usize == mem::size_of::<sockaddr_in>()); let ret = *(addr as *const _ as *const sockaddr_in); Ok(SockAddr::Inet(InetAddr::V4(ret))) } libc::AF_INET6 => { assert!(len as usize == mem::size_of::<sockaddr_in6>()); Ok(SockAddr::Inet(InetAddr::V6(*(addr as *const _ as *const sockaddr_in6)))) } libc::AF_UNIX => { let sun = *(addr as *const _ as *const sockaddr_un); let pathlen = len - offset_of!(sockaddr_un, sun_path); Ok(SockAddr::Unix(UnixAddr(sun, pathlen))) } #[cfg(any(target_os = "android", target_os = "linux"))] libc::AF_NETLINK => { use libc::sockaddr_nl; Ok(SockAddr::Netlink(NetlinkAddr(*(addr as *const _ as *const sockaddr_nl)))) } af => panic!("unexpected address family {}", af), } } #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)] pub enum Shutdown { /// Further receptions will be disallowed. Read, /// Further transmissions will be disallowed. Write, /// Further receptions and transmissions will be disallowed. Both, } /// Shut down part of a full-duplex connection. /// /// [Further reading](http://pubs.opengroup.org/onlinepubs/9699919799/functions/shutdown.html) pub fn shutdown(df: RawFd, how: Shutdown) -> Result<()> { unsafe { use libc::shutdown; let how = match how { Shutdown::Read => libc::SHUT_RD, Shutdown::Write => libc::SHUT_WR, Shutdown::Both => libc::SHUT_RDWR, }; Errno::result(shutdown(df, how)).map(drop) } }