diff options
Diffstat (limited to 'src/sys/socket/mod.rs')
| -rw-r--r-- | src/sys/socket/mod.rs | 425 |
1 files changed, 154 insertions, 271 deletions
diff --git a/src/sys/socket/mod.rs b/src/sys/socket/mod.rs index de6644bb..771ce8bf 100644 --- a/src/sys/socket/mod.rs +++ b/src/sys/socket/mod.rs @@ -333,13 +333,13 @@ pub trait CmsgBuffer { /// # use nix::sys::time::TimeVal; /// # use std::os::unix::io::RawFd; /// # fn main() { -/// // Create a buffer for a `ControlMessage::ScmTimestamp` message +/// // Create a buffer for a `ControlMessageOwned::ScmTimestamp` message /// let _ = cmsg_space!(TimeVal); -/// // Create a buffer big enough for a `ControlMessage::ScmRights` message +/// // Create a buffer big enough for a `ControlMessageOwned::ScmRights` message /// // with two file descriptors /// let _ = cmsg_space!([RawFd; 2]); -/// // Create a buffer big enough for a `ControlMessage::ScmRights` message -/// // and a `ControlMessage::ScmTimestamp` message +/// // Create a buffer big enough for a `ControlMessageOwned::ScmRights` message +/// // and a `ControlMessageOwned::ScmTimestamp` message /// let _ = cmsg_space!(RawFd, TimeVal); /// # } /// ``` @@ -440,15 +440,15 @@ pub struct CmsgIterator<'a> { } impl<'a> Iterator for CmsgIterator<'a> { - type Item = ControlMessage<'a>; + type Item = ControlMessageOwned; - fn next(&mut self) -> Option<ControlMessage<'a>> { + fn next(&mut self) -> Option<ControlMessageOwned> { match self.cmsghdr { None => None, // No more messages Some(hdr) => { // Get the data. // Safe if cmsghdr points to valid data returned by recvmsg(2) - let cm = unsafe { Some(ControlMessage::decode_from(hdr))}; + let cm = unsafe { Some(ControlMessageOwned::decode_from(hdr))}; // Advance the internal pointer. Safe if mhdr and cmsghdr point // to valid data returned by recvmsg(2) self.cmsghdr = unsafe { @@ -461,36 +461,25 @@ impl<'a> Iterator for CmsgIterator<'a> { } } -/// A type-safe wrapper around a single control message. More types may -/// be added to this enum; do not exhaustively pattern-match it. +/// A type-safe wrapper around a single control message, as used with +/// [`recvmsg`](#fn.recvmsg). +/// /// [Further reading](http://man7.org/linux/man-pages/man3/cmsg.3.html) +// Nix version 0.13.0 and earlier used ControlMessage for both recvmsg and +// sendmsg. However, on some platforms the messages returned by recvmsg may be +// unaligned. ControlMessageOwned takes those messages by copy, obviating any +// alignment issues. +// +// See https://github.com/nix-rust/nix/issues/999 #[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. +pub enum ControlMessageOwned { + /// Received version of + /// [`ControlMessage::ScmRights`][#enum.ControlMessage.html#variant.ScmRights] + ScmRights(Vec<RawFd>), + /// Received version of + /// [`ControlMessage::ScmCredentials`][#enum.ControlMessage.html#variant.ScmCredentials] #[cfg(any(target_os = "android", target_os = "linux"))] - ScmCredentials(&'a libc::ucred), + ScmCredentials(libc::ucred), /// A message of type `SCM_TIMESTAMP`, containing the time the /// packet was received by the kernel. /// @@ -533,7 +522,7 @@ pub enum ControlMessage<'a> { /// 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(ControlMessageOwned::ScmTimestamp(rtime)) => rtime, /// Some(_) => panic!("Unexpected control message"), /// None => panic!("No control message") /// }; @@ -549,14 +538,14 @@ pub enum ControlMessage<'a> { /// nix::unistd::close(in_socket).unwrap(); /// # } /// ``` - ScmTimestamp(&'a TimeVal), + ScmTimestamp(TimeVal), #[cfg(any( target_os = "android", target_os = "ios", target_os = "linux", target_os = "macos" ))] - Ipv4PacketInfo(&'a libc::in_pktinfo), + Ipv4PacketInfo(libc::in_pktinfo), #[cfg(any( target_os = "android", target_os = "freebsd", @@ -564,7 +553,7 @@ pub enum ControlMessage<'a> { target_os = "linux", target_os = "macos" ))] - Ipv6PacketInfo(&'a libc::in6_pktinfo), + Ipv6PacketInfo(libc::in6_pktinfo), #[cfg(any( target_os = "freebsd", target_os = "ios", @@ -572,7 +561,7 @@ pub enum ControlMessage<'a> { target_os = "netbsd", target_os = "openbsd", ))] - Ipv4RecvIf(&'a libc::sockaddr_dl), + Ipv4RecvIf(libc::sockaddr_dl), #[cfg(any( target_os = "freebsd", target_os = "ios", @@ -580,17 +569,138 @@ pub enum ControlMessage<'a> { target_os = "netbsd", target_os = "openbsd", ))] - Ipv4RecvDstAddr(&'a libc::in_addr), - + Ipv4RecvDstAddr(libc::in_addr), /// Catch-all variant for unimplemented cmsg types. #[doc(hidden)] - Unknown(UnknownCmsg<'a>), + Unknown(UnknownCmsg), +} + +impl ControlMessageOwned { + /// Decodes a `ControlMessageOwned` 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. + /// + /// Returns `None` if the data may be unaligned. In that case use + /// `ControlMessageOwned::decode_from`. + unsafe fn decode_from(header: &cmsghdr) -> ControlMessageOwned + { + let p = CMSG_DATA(header); + let len = header as *const _ as usize + header.cmsg_len as usize + - p as usize; + match (header.cmsg_level, header.cmsg_type) { + (libc::SOL_SOCKET, libc::SCM_RIGHTS) => { + let n = len / mem::size_of::<RawFd>(); + let mut fds = Vec::with_capacity(n); + for i in 0..n { + let fdp = (p as *const RawFd).offset(i as isize); + fds.push(ptr::read_unaligned(fdp)); + } + let cmo = ControlMessageOwned::ScmRights(fds); + cmo + }, + #[cfg(any(target_os = "android", target_os = "linux"))] + (libc::SOL_SOCKET, libc::SCM_CREDENTIALS) => { + let cred: libc::ucred = ptr::read_unaligned(p as *const _); + ControlMessageOwned::ScmCredentials(cred) + } + (libc::SOL_SOCKET, libc::SCM_TIMESTAMP) => { + let tv: libc::timeval = ptr::read_unaligned(p as *const _); + ControlMessageOwned::ScmTimestamp(TimeVal::from(tv)) + }, + #[cfg(any( + target_os = "android", + target_os = "freebsd", + target_os = "ios", + target_os = "linux", + target_os = "macos" + ))] + (libc::IPPROTO_IPV6, libc::IPV6_PKTINFO) => { + let info = ptr::read_unaligned(p as *const libc::in6_pktinfo); + ControlMessageOwned::Ipv6PacketInfo(info) + } + #[cfg(any( + target_os = "android", + target_os = "ios", + target_os = "linux", + target_os = "macos" + ))] + (libc::IPPROTO_IP, libc::IP_PKTINFO) => { + let info = ptr::read_unaligned(p as *const libc::in_pktinfo); + ControlMessageOwned::Ipv4PacketInfo(info) + } + #[cfg(any( + target_os = "freebsd", + target_os = "ios", + target_os = "macos", + target_os = "netbsd", + target_os = "openbsd", + ))] + (libc::IPPROTO_IP, libc::IP_RECVIF) => { + let dl = ptr::read_unaligned(p as *const libc::sockaddr_dl); + ControlMessageOwned::Ipv4RecvIf(dl) + }, + #[cfg(any( + target_os = "freebsd", + target_os = "ios", + target_os = "macos", + target_os = "netbsd", + target_os = "openbsd", + ))] + (libc::IPPROTO_IP, libc::IP_RECVDSTADDR) => { + let dl = ptr::read_unaligned(p as *const libc::in_addr); + ControlMessageOwned::Ipv4RecvDstAddr(dl) + }, + (_, _) => { + let sl = slice::from_raw_parts(p, len); + let ucmsg = UnknownCmsg(*header, Vec::<u8>::from(&sl[..])); + ControlMessageOwned::Unknown(ucmsg) + } + } + } +} + +/// A type-safe zero-copy wrapper around a single control message, as used wih +/// [`sendmsg`](#fn.sendmsg). 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), } // 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]); +pub struct UnknownCmsg(cmsghdr, Vec<u8>); impl<'a> ControlMessage<'a> { /// The value of CMSG_SPACE on this message. @@ -617,57 +727,12 @@ impl<'a> ControlMessage<'a> { fn data(&self) -> *const u8 { match self { &ControlMessage::ScmRights(fds) => { - fds as *const [RawFd] as *const u8 + fds as *const _ as *const u8 }, #[cfg(any(target_os = "android", target_os = "linux"))] &ControlMessage::ScmCredentials(creds) => { creds as *const libc::ucred as *const u8 } - &ControlMessage::ScmTimestamp(t) => { - t as *const TimeVal as *const u8 - }, - #[cfg(any( - target_os = "android", - target_os = "ios", - target_os = "linux", - target_os = "macos" - ))] - &ControlMessage::Ipv4PacketInfo(pktinfo) => { - pktinfo as *const libc::in_pktinfo as *const u8 - }, - #[cfg(any( - target_os = "android", - target_os = "freebsd", - target_os = "ios", - target_os = "linux", - target_os = "macos" - ))] - &ControlMessage::Ipv6PacketInfo(pktinfo) => { - pktinfo as *const libc::in6_pktinfo as *const u8 - }, - #[cfg(any( - target_os = "freebsd", - target_os = "ios", - target_os = "macos", - target_os = "netbsd", - target_os = "openbsd", - ))] - &ControlMessage::Ipv4RecvIf(dl) => { - dl as *const libc::sockaddr_dl as *const u8 - }, - #[cfg(any( - target_os = "freebsd", - target_os = "ios", - target_os = "macos", - target_os = "netbsd", - target_os = "openbsd", - ))] - &ControlMessage::Ipv4RecvDstAddr(in_addr) => { - in_addr as *const libc::in_addr as *const u8 - }, - &ControlMessage::Unknown(UnknownCmsg(_, bytes)) => { - bytes as *const _ as *const u8 - } } } @@ -681,51 +746,6 @@ impl<'a> ControlMessage<'a> { &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) - }, - #[cfg(any( - target_os = "freebsd", - target_os = "ios", - target_os = "macos", - target_os = "netbsd", - target_os = "openbsd", - ))] - &ControlMessage::Ipv4RecvIf(dl) => { - mem::size_of_val(dl) - }, - #[cfg(any( - target_os = "freebsd", - target_os = "ios", - target_os = "macos", - target_os = "netbsd", - target_os = "openbsd", - ))] - &ControlMessage::Ipv4RecvDstAddr(inaddr) => { - mem::size_of_val(inaddr) - }, - &ControlMessage::Unknown(UnknownCmsg(_, bytes)) => { - mem::size_of_val(bytes) - } } } @@ -735,39 +755,6 @@ impl<'a> ControlMessage<'a> { &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, - #[cfg(any( - target_os = "freebsd", - target_os = "ios", - target_os = "macos", - target_os = "netbsd", - target_os = "openbsd", - ))] - &ControlMessage::Ipv4RecvIf(_) => libc::IPPROTO_IP, - #[cfg(any( - target_os = "freebsd", - target_os = "ios", - target_os = "macos", - target_os = "netbsd", - target_os = "openbsd", - ))] - &ControlMessage::Ipv4RecvDstAddr(_) => libc::IPPROTO_IP, - &ControlMessage::Unknown(ref cmsg) => cmsg.0.cmsg_level, } } @@ -777,39 +764,6 @@ impl<'a> ControlMessage<'a> { &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, - #[cfg(any( - target_os = "freebsd", - target_os = "ios", - target_os = "macos", - target_os = "netbsd", - target_os = "openbsd", - ))] - &ControlMessage::Ipv4RecvIf(_) => libc::IP_RECVIF, - #[cfg(any( - target_os = "freebsd", - target_os = "ios", - target_os = "macos", - target_os = "netbsd", - target_os = "openbsd", - ))] - &ControlMessage::Ipv4RecvDstAddr(_) => libc::IP_RECVDSTADDR, - &ControlMessage::Unknown(ref cmsg) => cmsg.0.cmsg_type, } } @@ -826,77 +780,6 @@ impl<'a> ControlMessage<'a> { self.len() ); } - - /// 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) -> ControlMessage<'a> - { - let p = CMSG_DATA(header); - let len = header as *const _ as usize + header.cmsg_len as usize - - p as usize; - match (header.cmsg_level, header.cmsg_type) { - (libc::SOL_SOCKET, libc::SCM_RIGHTS) => { - ControlMessage::ScmRights( - slice::from_raw_parts(p as *const RawFd, - len / mem::size_of::<RawFd>())) - }, - #[cfg(any(target_os = "android", target_os = "linux"))] - (libc::SOL_SOCKET, libc::SCM_CREDENTIALS) => { - ControlMessage::ScmCredentials(&*(p as *const _)) - } - (libc::SOL_SOCKET, libc::SCM_TIMESTAMP) => { - ControlMessage::ScmTimestamp(&*(p 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(&*(p as *const _)) - } - #[cfg(any( - target_os = "android", - target_os = "ios", - target_os = "linux", - target_os = "macos" - ))] - (libc::IPPROTO_IP, libc::IP_PKTINFO) => { - ControlMessage::Ipv4PacketInfo(&*(p as *const _)) - } - #[cfg(any( - target_os = "freebsd", - target_os = "ios", - target_os = "macos", - target_os = "netbsd", - target_os = "openbsd", - ))] - (libc::IPPROTO_IP, libc::IP_RECVIF) => { - ControlMessage::Ipv4RecvIf(&*(p as *const _)) - } - #[cfg(any( - target_os = "freebsd", - target_os = "ios", - target_os = "macos", - target_os = "netbsd", - target_os = "openbsd", - ))] - (libc::IPPROTO_IP, libc::IP_RECVDSTADDR) => { - ControlMessage::Ipv4RecvDstAddr(&*(p as *const _)) - } - - (_, _) => { - let data = slice::from_raw_parts(p, len); - ControlMessage::Unknown(UnknownCmsg(header, data)) - } - } - } } |