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Diffstat (limited to '')
| -rw-r--r-- | library/std/src/os/unix/net/ancillary.rs | 674 |
1 files changed, 674 insertions, 0 deletions
diff --git a/library/std/src/os/unix/net/ancillary.rs b/library/std/src/os/unix/net/ancillary.rs new file mode 100644 index 000000000..7cc901a79 --- /dev/null +++ b/library/std/src/os/unix/net/ancillary.rs @@ -0,0 +1,674 @@ +// FIXME: This is currently disabled on *BSD. + +use super::{sockaddr_un, SocketAddr}; +use crate::io::{self, IoSlice, IoSliceMut}; +use crate::marker::PhantomData; +use crate::mem::{size_of, zeroed}; +use crate::os::unix::io::RawFd; +use crate::path::Path; +use crate::ptr::{eq, read_unaligned}; +use crate::slice::from_raw_parts; +use crate::sys::net::Socket; + +// FIXME(#43348): Make libc adapt #[doc(cfg(...))] so we don't need these fake definitions here? +#[cfg(all(doc, not(target_os = "linux"), not(target_os = "android"), not(target_os = "netbsd")))] +#[allow(non_camel_case_types)] +mod libc { + pub use libc::c_int; + pub struct ucred; + pub struct cmsghdr; + pub type pid_t = i32; + pub type gid_t = u32; + pub type uid_t = u32; +} + +pub(super) fn recv_vectored_with_ancillary_from( + socket: &Socket, + bufs: &mut [IoSliceMut<'_>], + ancillary: &mut SocketAncillary<'_>, +) -> io::Result<(usize, bool, io::Result<SocketAddr>)> { + unsafe { + let mut msg_name: libc::sockaddr_un = zeroed(); + let mut msg: libc::msghdr = zeroed(); + msg.msg_name = &mut msg_name as *mut _ as *mut _; + msg.msg_namelen = size_of::<libc::sockaddr_un>() as libc::socklen_t; + msg.msg_iov = bufs.as_mut_ptr().cast(); + msg.msg_iovlen = bufs.len() as _; + msg.msg_controllen = ancillary.buffer.len() as _; + // macos requires that the control pointer is null when the len is 0. + if msg.msg_controllen > 0 { + msg.msg_control = ancillary.buffer.as_mut_ptr().cast(); + } + + let count = socket.recv_msg(&mut msg)?; + + ancillary.length = msg.msg_controllen as usize; + ancillary.truncated = msg.msg_flags & libc::MSG_CTRUNC == libc::MSG_CTRUNC; + + let truncated = msg.msg_flags & libc::MSG_TRUNC == libc::MSG_TRUNC; + let addr = SocketAddr::from_parts(msg_name, msg.msg_namelen); + + Ok((count, truncated, addr)) + } +} + +pub(super) fn send_vectored_with_ancillary_to( + socket: &Socket, + path: Option<&Path>, + bufs: &[IoSlice<'_>], + ancillary: &mut SocketAncillary<'_>, +) -> io::Result<usize> { + unsafe { + let (mut msg_name, msg_namelen) = + if let Some(path) = path { sockaddr_un(path)? } else { (zeroed(), 0) }; + + let mut msg: libc::msghdr = zeroed(); + msg.msg_name = &mut msg_name as *mut _ as *mut _; + msg.msg_namelen = msg_namelen; + msg.msg_iov = bufs.as_ptr() as *mut _; + msg.msg_iovlen = bufs.len() as _; + msg.msg_controllen = ancillary.length as _; + // macos requires that the control pointer is null when the len is 0. + if msg.msg_controllen > 0 { + msg.msg_control = ancillary.buffer.as_mut_ptr().cast(); + } + + ancillary.truncated = false; + + socket.send_msg(&mut msg) + } +} + +fn add_to_ancillary_data<T>( + buffer: &mut [u8], + length: &mut usize, + source: &[T], + cmsg_level: libc::c_int, + cmsg_type: libc::c_int, +) -> bool { + let source_len = if let Some(source_len) = source.len().checked_mul(size_of::<T>()) { + if let Ok(source_len) = u32::try_from(source_len) { + source_len + } else { + return false; + } + } else { + return false; + }; + + unsafe { + let additional_space = libc::CMSG_SPACE(source_len) as usize; + + let new_length = if let Some(new_length) = additional_space.checked_add(*length) { + new_length + } else { + return false; + }; + + if new_length > buffer.len() { + return false; + } + + buffer[*length..new_length].fill(0); + + *length = new_length; + + let mut msg: libc::msghdr = zeroed(); + msg.msg_control = buffer.as_mut_ptr().cast(); + msg.msg_controllen = *length as _; + + let mut cmsg = libc::CMSG_FIRSTHDR(&msg); + let mut previous_cmsg = cmsg; + while !cmsg.is_null() { + previous_cmsg = cmsg; + cmsg = libc::CMSG_NXTHDR(&msg, cmsg); + + // Most operating systems, but not Linux or emscripten, return the previous pointer + // when its length is zero. Therefore, check if the previous pointer is the same as + // the current one. + if eq(cmsg, previous_cmsg) { + break; + } + } + + if previous_cmsg.is_null() { + return false; + } + + (*previous_cmsg).cmsg_level = cmsg_level; + (*previous_cmsg).cmsg_type = cmsg_type; + (*previous_cmsg).cmsg_len = libc::CMSG_LEN(source_len) as _; + + let data = libc::CMSG_DATA(previous_cmsg).cast(); + + libc::memcpy(data, source.as_ptr().cast(), source_len as usize); + } + true +} + +struct AncillaryDataIter<'a, T> { + data: &'a [u8], + phantom: PhantomData<T>, +} + +impl<'a, T> AncillaryDataIter<'a, T> { + /// Create `AncillaryDataIter` struct to iterate through the data unit in the control message. + /// + /// # Safety + /// + /// `data` must contain a valid control message. + unsafe fn new(data: &'a [u8]) -> AncillaryDataIter<'a, T> { + AncillaryDataIter { data, phantom: PhantomData } + } +} + +impl<'a, T> Iterator for AncillaryDataIter<'a, T> { + type Item = T; + + fn next(&mut self) -> Option<T> { + if size_of::<T>() <= self.data.len() { + unsafe { + let unit = read_unaligned(self.data.as_ptr().cast()); + self.data = &self.data[size_of::<T>()..]; + Some(unit) + } + } else { + None + } + } +} + +#[cfg(all(doc, not(target_os = "android"), not(target_os = "linux"), not(target_os = "netbsd")))] +#[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] +#[derive(Clone)] +pub struct SocketCred(()); + +/// Unix credential. +#[cfg(any(target_os = "android", target_os = "linux",))] +#[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] +#[derive(Clone)] +pub struct SocketCred(libc::ucred); + +#[cfg(target_os = "netbsd")] +#[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] +#[derive(Clone)] +pub struct SocketCred(libc::sockcred); + +#[doc(cfg(any(target_os = "android", target_os = "linux")))] +#[cfg(any(target_os = "android", target_os = "linux"))] +impl SocketCred { + /// Create a Unix credential struct. + /// + /// PID, UID and GID is set to 0. + #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] + #[must_use] + pub fn new() -> SocketCred { + SocketCred(libc::ucred { pid: 0, uid: 0, gid: 0 }) + } + + /// Set the PID. + #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] + pub fn set_pid(&mut self, pid: libc::pid_t) { + self.0.pid = pid; + } + + /// Get the current PID. + #[must_use] + #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] + pub fn get_pid(&self) -> libc::pid_t { + self.0.pid + } + + /// Set the UID. + #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] + pub fn set_uid(&mut self, uid: libc::uid_t) { + self.0.uid = uid; + } + + /// Get the current UID. + #[must_use] + #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] + pub fn get_uid(&self) -> libc::uid_t { + self.0.uid + } + + /// Set the GID. + #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] + pub fn set_gid(&mut self, gid: libc::gid_t) { + self.0.gid = gid; + } + + /// Get the current GID. + #[must_use] + #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] + pub fn get_gid(&self) -> libc::gid_t { + self.0.gid + } +} + +#[cfg(target_os = "netbsd")] +impl SocketCred { + /// Create a Unix credential struct. + /// + /// PID, UID and GID is set to 0. + #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] + pub fn new() -> SocketCred { + SocketCred(libc::sockcred { + sc_pid: 0, + sc_uid: 0, + sc_euid: 0, + sc_gid: 0, + sc_egid: 0, + sc_ngroups: 0, + sc_groups: [0u32; 1], + }) + } + + /// Set the PID. + #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] + pub fn set_pid(&mut self, pid: libc::pid_t) { + self.0.sc_pid = pid; + } + + /// Get the current PID. + #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] + pub fn get_pid(&self) -> libc::pid_t { + self.0.sc_pid + } + + /// Set the UID. + #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] + pub fn set_uid(&mut self, uid: libc::uid_t) { + self.0.sc_uid = uid; + } + + /// Get the current UID. + #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] + pub fn get_uid(&self) -> libc::uid_t { + self.0.sc_uid + } + + /// Set the GID. + #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] + pub fn set_gid(&mut self, gid: libc::gid_t) { + self.0.sc_gid = gid; + } + + /// Get the current GID. + #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] + pub fn get_gid(&self) -> libc::gid_t { + self.0.sc_gid + } +} + +/// This control message contains file descriptors. +/// +/// The level is equal to `SOL_SOCKET` and the type is equal to `SCM_RIGHTS`. +#[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] +pub struct ScmRights<'a>(AncillaryDataIter<'a, RawFd>); + +#[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] +impl<'a> Iterator for ScmRights<'a> { + type Item = RawFd; + + fn next(&mut self) -> Option<RawFd> { + self.0.next() + } +} + +#[cfg(all(doc, not(target_os = "android"), not(target_os = "linux"), not(target_os = "netbsd")))] +#[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] +pub struct ScmCredentials<'a>(AncillaryDataIter<'a, ()>); + +/// This control message contains unix credentials. +/// +/// The level is equal to `SOL_SOCKET` and the type is equal to `SCM_CREDENTIALS` or `SCM_CREDS`. +#[cfg(any(target_os = "android", target_os = "linux",))] +#[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] +pub struct ScmCredentials<'a>(AncillaryDataIter<'a, libc::ucred>); + +#[cfg(target_os = "netbsd")] +#[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] +pub struct ScmCredentials<'a>(AncillaryDataIter<'a, libc::sockcred>); + +#[cfg(any(doc, target_os = "android", target_os = "linux", target_os = "netbsd",))] +#[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] +impl<'a> Iterator for ScmCredentials<'a> { + type Item = SocketCred; + + fn next(&mut self) -> Option<SocketCred> { + Some(SocketCred(self.0.next()?)) + } +} + +/// The error type which is returned from parsing the type a control message. +#[non_exhaustive] +#[derive(Debug)] +#[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] +pub enum AncillaryError { + Unknown { cmsg_level: i32, cmsg_type: i32 }, +} + +/// This enum represent one control message of variable type. +#[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] +pub enum AncillaryData<'a> { + ScmRights(ScmRights<'a>), + #[cfg(any(doc, target_os = "android", target_os = "linux", target_os = "netbsd",))] + ScmCredentials(ScmCredentials<'a>), +} + +impl<'a> AncillaryData<'a> { + /// Create an `AncillaryData::ScmRights` variant. + /// + /// # Safety + /// + /// `data` must contain a valid control message and the control message must be type of + /// `SOL_SOCKET` and level of `SCM_RIGHTS`. + unsafe fn as_rights(data: &'a [u8]) -> Self { + let ancillary_data_iter = AncillaryDataIter::new(data); + let scm_rights = ScmRights(ancillary_data_iter); + AncillaryData::ScmRights(scm_rights) + } + + /// Create an `AncillaryData::ScmCredentials` variant. + /// + /// # Safety + /// + /// `data` must contain a valid control message and the control message must be type of + /// `SOL_SOCKET` and level of `SCM_CREDENTIALS` or `SCM_CREDS`. + #[cfg(any(doc, target_os = "android", target_os = "linux", target_os = "netbsd",))] + unsafe fn as_credentials(data: &'a [u8]) -> Self { + let ancillary_data_iter = AncillaryDataIter::new(data); + let scm_credentials = ScmCredentials(ancillary_data_iter); + AncillaryData::ScmCredentials(scm_credentials) + } + + fn try_from_cmsghdr(cmsg: &'a libc::cmsghdr) -> Result<Self, AncillaryError> { + unsafe { + let cmsg_len_zero = libc::CMSG_LEN(0) as usize; + let data_len = (*cmsg).cmsg_len as usize - cmsg_len_zero; + let data = libc::CMSG_DATA(cmsg).cast(); + let data = from_raw_parts(data, data_len); + + match (*cmsg).cmsg_level { + libc::SOL_SOCKET => match (*cmsg).cmsg_type { + libc::SCM_RIGHTS => Ok(AncillaryData::as_rights(data)), + #[cfg(any(target_os = "android", target_os = "linux",))] + libc::SCM_CREDENTIALS => Ok(AncillaryData::as_credentials(data)), + #[cfg(target_os = "netbsd")] + libc::SCM_CREDS => Ok(AncillaryData::as_credentials(data)), + cmsg_type => { + Err(AncillaryError::Unknown { cmsg_level: libc::SOL_SOCKET, cmsg_type }) + } + }, + cmsg_level => { + Err(AncillaryError::Unknown { cmsg_level, cmsg_type: (*cmsg).cmsg_type }) + } + } + } + } +} + +/// This struct is used to iterate through the control messages. +#[must_use = "iterators are lazy and do nothing unless consumed"] +#[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] +pub struct Messages<'a> { + buffer: &'a [u8], + current: Option<&'a libc::cmsghdr>, +} + +#[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] +impl<'a> Iterator for Messages<'a> { + type Item = Result<AncillaryData<'a>, AncillaryError>; + + fn next(&mut self) -> Option<Self::Item> { + unsafe { + let mut msg: libc::msghdr = zeroed(); + msg.msg_control = self.buffer.as_ptr() as *mut _; + msg.msg_controllen = self.buffer.len() as _; + + let cmsg = if let Some(current) = self.current { + libc::CMSG_NXTHDR(&msg, current) + } else { + libc::CMSG_FIRSTHDR(&msg) + }; + + let cmsg = cmsg.as_ref()?; + + // Most operating systems, but not Linux or emscripten, return the previous pointer + // when its length is zero. Therefore, check if the previous pointer is the same as + // the current one. + if let Some(current) = self.current { + if eq(current, cmsg) { + return None; + } + } + + self.current = Some(cmsg); + let ancillary_result = AncillaryData::try_from_cmsghdr(cmsg); + Some(ancillary_result) + } + } +} + +/// A Unix socket Ancillary data struct. +/// +/// # Example +/// ```no_run +/// #![feature(unix_socket_ancillary_data)] +/// use std::os::unix::net::{UnixStream, SocketAncillary, AncillaryData}; +/// use std::io::IoSliceMut; +/// +/// fn main() -> std::io::Result<()> { +/// let sock = UnixStream::connect("/tmp/sock")?; +/// +/// let mut fds = [0; 8]; +/// let mut ancillary_buffer = [0; 128]; +/// let mut ancillary = SocketAncillary::new(&mut ancillary_buffer[..]); +/// +/// let mut buf = [1; 8]; +/// let mut bufs = &mut [IoSliceMut::new(&mut buf[..])][..]; +/// sock.recv_vectored_with_ancillary(bufs, &mut ancillary)?; +/// +/// for ancillary_result in ancillary.messages() { +/// if let AncillaryData::ScmRights(scm_rights) = ancillary_result.unwrap() { +/// for fd in scm_rights { +/// println!("receive file descriptor: {fd}"); +/// } +/// } +/// } +/// Ok(()) +/// } +/// ``` +#[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] +#[derive(Debug)] +pub struct SocketAncillary<'a> { + buffer: &'a mut [u8], + length: usize, + truncated: bool, +} + +impl<'a> SocketAncillary<'a> { + /// Create an ancillary data with the given buffer. + /// + /// # Example + /// + /// ```no_run + /// # #![allow(unused_mut)] + /// #![feature(unix_socket_ancillary_data)] + /// use std::os::unix::net::SocketAncillary; + /// let mut ancillary_buffer = [0; 128]; + /// let mut ancillary = SocketAncillary::new(&mut ancillary_buffer[..]); + /// ``` + #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] + pub fn new(buffer: &'a mut [u8]) -> Self { + SocketAncillary { buffer, length: 0, truncated: false } + } + + /// Returns the capacity of the buffer. + #[must_use] + #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] + pub fn capacity(&self) -> usize { + self.buffer.len() + } + + /// Returns `true` if the ancillary data is empty. + #[must_use] + #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] + pub fn is_empty(&self) -> bool { + self.length == 0 + } + + /// Returns the number of used bytes. + #[must_use] + #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] + pub fn len(&self) -> usize { + self.length + } + + /// Returns the iterator of the control messages. + #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] + pub fn messages(&self) -> Messages<'_> { + Messages { buffer: &self.buffer[..self.length], current: None } + } + + /// Is `true` if during a recv operation the ancillary was truncated. + /// + /// # Example + /// + /// ```no_run + /// #![feature(unix_socket_ancillary_data)] + /// use std::os::unix::net::{UnixStream, SocketAncillary}; + /// use std::io::IoSliceMut; + /// + /// fn main() -> std::io::Result<()> { + /// let sock = UnixStream::connect("/tmp/sock")?; + /// + /// let mut ancillary_buffer = [0; 128]; + /// let mut ancillary = SocketAncillary::new(&mut ancillary_buffer[..]); + /// + /// let mut buf = [1; 8]; + /// let mut bufs = &mut [IoSliceMut::new(&mut buf[..])][..]; + /// sock.recv_vectored_with_ancillary(bufs, &mut ancillary)?; + /// + /// println!("Is truncated: {}", ancillary.truncated()); + /// Ok(()) + /// } + /// ``` + #[must_use] + #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] + pub fn truncated(&self) -> bool { + self.truncated + } + + /// Add file descriptors to the ancillary data. + /// + /// The function returns `true` if there was enough space in the buffer. + /// If there was not enough space then no file descriptors was appended. + /// Technically, that means this operation adds a control message with the level `SOL_SOCKET` + /// and type `SCM_RIGHTS`. + /// + /// # Example + /// + /// ```no_run + /// #![feature(unix_socket_ancillary_data)] + /// use std::os::unix::net::{UnixStream, SocketAncillary}; + /// use std::os::unix::io::AsRawFd; + /// use std::io::IoSlice; + /// + /// fn main() -> std::io::Result<()> { + /// let sock = UnixStream::connect("/tmp/sock")?; + /// + /// let mut ancillary_buffer = [0; 128]; + /// let mut ancillary = SocketAncillary::new(&mut ancillary_buffer[..]); + /// ancillary.add_fds(&[sock.as_raw_fd()][..]); + /// + /// let buf = [1; 8]; + /// let mut bufs = &mut [IoSlice::new(&buf[..])][..]; + /// sock.send_vectored_with_ancillary(bufs, &mut ancillary)?; + /// Ok(()) + /// } + /// ``` + #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] + pub fn add_fds(&mut self, fds: &[RawFd]) -> bool { + self.truncated = false; + add_to_ancillary_data( + &mut self.buffer, + &mut self.length, + fds, + libc::SOL_SOCKET, + libc::SCM_RIGHTS, + ) + } + + /// Add credentials to the ancillary data. + /// + /// The function returns `true` if there was enough space in the buffer. + /// If there was not enough space then no credentials was appended. + /// Technically, that means this operation adds a control message with the level `SOL_SOCKET` + /// and type `SCM_CREDENTIALS` or `SCM_CREDS`. + /// + #[cfg(any(doc, target_os = "android", target_os = "linux", target_os = "netbsd",))] + #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] + pub fn add_creds(&mut self, creds: &[SocketCred]) -> bool { + self.truncated = false; + add_to_ancillary_data( + &mut self.buffer, + &mut self.length, + creds, + libc::SOL_SOCKET, + #[cfg(not(target_os = "netbsd"))] + libc::SCM_CREDENTIALS, + #[cfg(target_os = "netbsd")] + libc::SCM_CREDS, + ) + } + + /// Clears the ancillary data, removing all values. + /// + /// # Example + /// + /// ```no_run + /// #![feature(unix_socket_ancillary_data)] + /// use std::os::unix::net::{UnixStream, SocketAncillary, AncillaryData}; + /// use std::io::IoSliceMut; + /// + /// fn main() -> std::io::Result<()> { + /// let sock = UnixStream::connect("/tmp/sock")?; + /// + /// let mut fds1 = [0; 8]; + /// let mut fds2 = [0; 8]; + /// let mut ancillary_buffer = [0; 128]; + /// let mut ancillary = SocketAncillary::new(&mut ancillary_buffer[..]); + /// + /// let mut buf = [1; 8]; + /// let mut bufs = &mut [IoSliceMut::new(&mut buf[..])][..]; + /// + /// sock.recv_vectored_with_ancillary(bufs, &mut ancillary)?; + /// for ancillary_result in ancillary.messages() { + /// if let AncillaryData::ScmRights(scm_rights) = ancillary_result.unwrap() { + /// for fd in scm_rights { + /// println!("receive file descriptor: {fd}"); + /// } + /// } + /// } + /// + /// ancillary.clear(); + /// + /// sock.recv_vectored_with_ancillary(bufs, &mut ancillary)?; + /// for ancillary_result in ancillary.messages() { + /// if let AncillaryData::ScmRights(scm_rights) = ancillary_result.unwrap() { + /// for fd in scm_rights { + /// println!("receive file descriptor: {fd}"); + /// } + /// } + /// } + /// Ok(()) + /// } + /// ``` + #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")] + pub fn clear(&mut self) { + self.length = 0; + self.truncated = false; + } +} |