Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

refactor: I/O safety for control msg ScmRights #2494

Open
wants to merge 4 commits into
base: master
Choose a base branch
from
Open

refactor: I/O safety for control msg ScmRights #2494

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
d0c48f4
refactor: I/O safety for control msg ScmRights
SteveLauC Sep 9, 2024
fb8701c
test: try to fix test on Linux
SteveLauC Sep 9, 2024
fbbccff
test: try to fix test on Linux
SteveLauC Sep 9, 2024
57ebe0a
test: try to fix test on Linux
SteveLauC Sep 9, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
32 changes: 17 additions & 15 deletions src/sys/socket/mod.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -19,7 +19,7 @@ use libc::{
use std::io::{IoSlice, IoSliceMut};
#[cfg(feature = "net")]
use std::net;
use std::os::unix::io::{AsFd, AsRawFd, FromRawFd, OwnedFd, RawFd};
use std::os::unix::io::{AsFd, AsRawFd, FromRawFd, OwnedFd, RawFd, BorrowedFd};
use std::{mem, ptr};

#[deny(missing_docs)]
Expand All @@ -35,6 +35,9 @@ pub mod sockopt;

pub use self::addr::{SockaddrLike, SockaddrStorage};

#[cfg(feature = "net")]
use crate::sys::socket::addr::{ipv4addr_to_libc, ipv6addr_to_libc};

#[cfg(solarish)]
pub use self::addr::{AddressFamily, UnixAddr};
#[cfg(not(solarish))]
Expand Down Expand Up @@ -62,9 +65,6 @@ pub use libc::{sa_family_t, sockaddr, sockaddr_storage, sockaddr_un};
#[cfg(feature = "net")]
pub use libc::{sockaddr_in, sockaddr_in6};

#[cfg(feature = "net")]
use crate::sys::socket::addr::{ipv4addr_to_libc, ipv6addr_to_libc};

/// These constants are used to specify the communication semantics
/// when creating a socket with [`socket()`](fn.socket.html)
#[derive(Clone, Copy, PartialEq, Eq, Debug)]
Expand Down Expand Up @@ -556,16 +556,16 @@ feature! {
/// ```
/// # #[macro_use] extern crate nix;
/// # use nix::sys::time::TimeVal;
/// # use std::os::unix::io::RawFd;
/// # use std::os::fd::OwnedFd;
/// # fn main() {
/// // Create a buffer for a `ControlMessageOwned::ScmTimestamp` message
/// let _ = cmsg_space!(TimeVal);
/// // Create a buffer big enough for a `ControlMessageOwned::ScmRights` message
/// // with two file descriptors
/// let _ = cmsg_space!([RawFd; 2]);
/// let _ = cmsg_space!([OwnedFd; 2]);
/// // Create a buffer big enough for a `ControlMessageOwned::ScmRights` message
/// // and a `ControlMessageOwned::ScmTimestamp` message
/// let _ = cmsg_space!(RawFd, TimeVal);
/// let _ = cmsg_space!(OwnedFd, TimeVal);
/// # }
/// ```
#[macro_export]
Expand Down Expand Up @@ -655,11 +655,11 @@ impl<'a> Iterator for CmsgIterator<'a> {
// alignment issues.
//
// See https://github.com/nix-rust/nix/issues/999
#[derive(Clone, Debug, Eq, PartialEq)]
#[derive(Debug)]
#[non_exhaustive]
pub enum ControlMessageOwned {
/// Received version of [`ControlMessage::ScmRights`]
ScmRights(Vec<RawFd>),
ScmRights(Vec<OwnedFd>),
/// Received version of [`ControlMessage::ScmCredentials`]
#[cfg(linux_android)]
ScmCredentials(UnixCredentials),
Expand Down Expand Up @@ -908,11 +908,11 @@ impl ControlMessageOwned {
- p as usize;
match (header.cmsg_level, header.cmsg_type) {
(libc::SOL_SOCKET, libc::SCM_RIGHTS) => {
let n = len / mem::size_of::<RawFd>();
let n = len / mem::size_of::<OwnedFd>();
let mut fds = Vec::with_capacity(n);
for i in 0..n {
unsafe {
let fdp = (p as *const RawFd).add(i);
let fdp = (p as *const OwnedFd).add(i);
fds.push(ptr::read_unaligned(fdp));
}
}
Expand Down Expand Up @@ -1094,7 +1094,7 @@ impl ControlMessageOwned {
/// pattern-match it.
///
/// [Further reading](https://man7.org/linux/man-pages/man3/cmsg.3.html)
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
#[derive(Clone, Copy, Debug)]
#[non_exhaustive]
pub enum ControlMessage<'a> {
/// A message of type `SCM_RIGHTS`, containing an array of file
Expand All @@ -1108,7 +1108,7 @@ pub enum ControlMessage<'a> {
/// 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]),
ScmRights(&'a [BorrowedFd<'a>]),
/// A message of type `SCM_CREDENTIALS`, containing the pid, uid and gid of
/// a process connected to the socket.
///
Expand Down Expand Up @@ -1586,13 +1586,14 @@ impl<'a> ControlMessage<'a> {
/// # use nix::unistd::pipe;
/// # use std::io::IoSlice;
/// # use std::os::unix::io::AsRawFd;
/// # use std::os::unix::io::AsFd;
/// let (fd1, fd2) = socketpair(AddressFamily::Unix, SockType::Stream, None,
/// SockFlag::empty())
/// .unwrap();
/// let (r, w) = pipe().unwrap();
///
/// let iov = [IoSlice::new(b"hello")];
/// let fds = [r.as_raw_fd()];
/// let fds = [r.as_fd()];
/// let cmsg = ControlMessage::ScmRights(&fds);
/// sendmsg::<()>(fd1.as_raw_fd(), &iov, &[cmsg], MsgFlags::empty(), None).unwrap();
/// ```
Expand All @@ -1602,14 +1603,15 @@ impl<'a> ControlMessage<'a> {
/// # use nix::unistd::pipe;
/// # use std::io::IoSlice;
/// # use std::str::FromStr;
/// # use std::os::unix::io::AsFd;
/// # use std::os::unix::io::AsRawFd;
/// let localhost = SockaddrIn::from_str("1.2.3.4:8080").unwrap();
/// let fd = socket(AddressFamily::Inet, SockType::Datagram, SockFlag::empty(),
/// None).unwrap();
/// let (r, w) = pipe().unwrap();
///
/// let iov = [IoSlice::new(b"hello")];
/// let fds = [r.as_raw_fd()];
/// let fds = [r.as_fd()];
/// let cmsg = ControlMessage::ScmRights(&fds);
/// sendmsg(fd.as_raw_fd(), &iov, &[cmsg], MsgFlags::empty(), Some(&localhost)).unwrap();
/// ```
Expand Down
54 changes: 22 additions & 32 deletions test/sys/test_socket.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -5,6 +5,7 @@ use nix::sys::socket::{getsockname, AddressFamily, UnixAddr};
use std::collections::hash_map::DefaultHasher;
use std::hash::{Hash, Hasher};
use std::net::{SocketAddrV4, SocketAddrV6};
use std::os::fd::AsFd;
use std::os::unix::io::{AsRawFd, RawFd};
use std::path::Path;
use std::slice;
Expand Down Expand Up @@ -846,8 +847,9 @@ pub fn test_scm_rights() {
recvmsg, sendmsg, socketpair, AddressFamily, ControlMessage,
ControlMessageOwned, MsgFlags, SockFlag, SockType,
};
use nix::unistd::{close, pipe, read, write};
use nix::unistd::{pipe, read, write};
use std::io::{IoSlice, IoSliceMut};
use std::os::fd::OwnedFd;

let (fd1, fd2) = socketpair(
AddressFamily::Unix,
Expand All @@ -857,11 +859,11 @@ pub fn test_scm_rights() {
)
.unwrap();
let (r, w) = pipe().unwrap();
let mut received_r: Option<RawFd> = None;
let mut received_r: Option<OwnedFd> = None;

{
let iov = [IoSlice::new(b"hello")];
let fds = [r.as_raw_fd()];
let fds = [r.as_fd()];
let cmsg = ControlMessage::ScmRights(&fds);
assert_eq!(
sendmsg::<()>(
Expand Down Expand Up @@ -890,10 +892,10 @@ pub fn test_scm_rights() {
.unwrap();

for cmsg in msg.cmsgs().unwrap() {
if let ControlMessageOwned::ScmRights(fd) = cmsg {
assert_eq!(received_r, None);
if let ControlMessageOwned::ScmRights(mut fd) = cmsg {
assert!(received_r.is_none());
assert_eq!(fd.len(), 1);
received_r = Some(fd[0]);
received_r = Some(fd.pop().unwrap());
} else {
panic!("unexpected cmsg");
}
Expand All @@ -908,15 +910,8 @@ pub fn test_scm_rights() {
// Ensure that the received file descriptor works
write(&w, b"world").unwrap();
let mut buf = [0u8; 5];
// SAFETY:
// should be safe since we don't use it after close
let borrowed_received_r =
unsafe { std::os::fd::BorrowedFd::borrow_raw(received_r) };
read(borrowed_received_r, &mut buf).unwrap();
read(&received_r, &mut buf).unwrap();
assert_eq!(&buf[..], b"world");
// SAFETY:
// there shouldn't be double close
unsafe { close(received_r).unwrap() };
}

// Disable the test on emulated platforms due to not enabled support of AF_ALG in QEMU from rust cross
Expand Down Expand Up @@ -1333,7 +1328,8 @@ fn test_scm_rights_single_cmsg_multiple_fds() {
recvmsg, sendmsg, ControlMessage, ControlMessageOwned, MsgFlags,
};
use std::io::{IoSlice, IoSliceMut};
use std::os::unix::io::{AsRawFd, RawFd};
use std::os::fd::BorrowedFd;
use std::os::unix::io::AsRawFd;
use std::os::unix::net::UnixDatagram;
use std::thread;

Expand All @@ -1342,7 +1338,7 @@ fn test_scm_rights_single_cmsg_multiple_fds() {
let mut buf = [0u8; 8];
let mut iovec = [IoSliceMut::new(&mut buf)];

let mut space = cmsg_space!([RawFd; 2]);
let mut space = cmsg_space!([BorrowedFd; 2]);
let msg = recvmsg::<()>(
receive.as_raw_fd(),
&mut iovec,
Expand Down Expand Up @@ -1374,7 +1370,9 @@ fn test_scm_rights_single_cmsg_multiple_fds() {

let slice = [1u8, 2, 3, 4, 5, 6, 7, 8];
let iov = [IoSlice::new(&slice)];
let fds = [libc::STDIN_FILENO, libc::STDOUT_FILENO]; // pass stdin and stdout
let stdin_owned = std::io::stdin();
let stdout_owned = std::io::stdout();
let fds = [stdin_owned.as_fd(), stdout_owned.as_fd()]; // pass stdin and stdout
let cmsg = [ControlMessage::ScmRights(&fds)];
sendmsg::<()>(send.as_raw_fd(), &iov, &cmsg, MsgFlags::empty(), None)
.unwrap();
Expand Down Expand Up @@ -1556,7 +1554,7 @@ fn test_impl_scm_credentials_and_rights(
recvmsg, sendmsg, setsockopt, socketpair, ControlMessage,
ControlMessageOwned, MsgFlags, SockFlag, SockType,
};
use nix::unistd::{close, getgid, getpid, getuid, pipe, write};
use nix::unistd::{getgid, getpid, getuid, pipe, write};
use std::io::{IoSlice, IoSliceMut};

let (send, recv) = socketpair(
Expand All @@ -1569,7 +1567,7 @@ fn test_impl_scm_credentials_and_rights(
setsockopt(&recv, PassCred, &true).unwrap();

let (r, w) = pipe().unwrap();
let mut received_r: Option<RawFd> = None;
let mut received_r = None;

{
let iov = [IoSlice::new(b"hello")];
Expand All @@ -1579,7 +1577,7 @@ fn test_impl_scm_credentials_and_rights(
gid: getgid().as_raw(),
}
.into();
let fds = [r.as_raw_fd()];
let fds = [r.as_fd()];
let cmsgs = [
ControlMessage::ScmCredentials(&cred),
ControlMessage::ScmRights(&fds),
Expand Down Expand Up @@ -1613,10 +1611,10 @@ fn test_impl_scm_credentials_and_rights(

for cmsg in msg.cmsgs()? {
match cmsg {
ControlMessageOwned::ScmRights(fds) => {
assert_eq!(received_r, None, "already received fd");
ControlMessageOwned::ScmRights(mut fds) => {
assert!(received_r.is_none(), "already received fd");
assert_eq!(fds.len(), 1);
received_r = Some(fds[0]);
received_r = Some(fds.pop().unwrap());
}
ControlMessageOwned::ScmCredentials(cred) => {
assert!(received_cred.is_none());
Expand All @@ -1639,16 +1637,8 @@ fn test_impl_scm_credentials_and_rights(
// Ensure that the received file descriptor works
write(&w, b"world").unwrap();
let mut buf = [0u8; 5];
// SAFETY:
// It should be safe if we don't use this BorrowedFd after close.
let received_r_borrowed =
unsafe { std::os::fd::BorrowedFd::borrow_raw(received_r) };
read(received_r_borrowed, &mut buf).unwrap();
read(&received_r, &mut buf).unwrap();
assert_eq!(&buf[..], b"world");
// SAFETY:
// double-close won't happen
unsafe { close(received_r).unwrap() };

Ok(())
}

Expand Down
Loading