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

recvmsg: Check if CMSG buffer was too small and return an error #2413

Merged
merged 1 commit into from
May 22, 2024
Merged

recvmsg: Check if CMSG buffer was too small and return an error #2413

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
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
1 change: 1 addition & 0 deletions changelog/2413.changed.md
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1 @@
`RecvMsg::cmsgs()` now returns a `Result`, and checks that cmsgs were not truncated.
19 changes: 13 additions & 6 deletions src/sys/socket/mod.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -13,6 +13,7 @@ use libc::{self, c_int, size_t, socklen_t};
#[cfg(all(feature = "uio", not(target_os = "redox")))]
use libc::{
c_void, iovec, CMSG_DATA, CMSG_FIRSTHDR, CMSG_LEN, CMSG_NXTHDR, CMSG_SPACE,
MSG_CTRUNC,
};
#[cfg(not(target_os = "redox"))]
use std::io::{IoSlice, IoSliceMut};
Expand Down Expand Up @@ -599,13 +600,19 @@ pub struct RecvMsg<'a, 's, S> {
}

impl<'a, S> RecvMsg<'a, '_, S> {
/// Iterate over the valid control messages pointed to by this
/// msghdr.
pub fn cmsgs(&self) -> CmsgIterator {
CmsgIterator {
/// Iterate over the valid control messages pointed to by this msghdr. If
/// allocated space for CMSGs was too small it is not safe to iterate,
/// instead return an `Error::ENOBUFS` error.
pub fn cmsgs(&self) -> Result<CmsgIterator> {

if self.mhdr.msg_flags & MSG_CTRUNC == MSG_CTRUNC {
return Err(Errno::ENOBUFS);
}

Ok(CmsgIterator {
cmsghdr: self.cmsghdr,
mhdr: &self.mhdr
}
})
}
}

Expand Down Expand Up @@ -700,7 +707,7 @@ pub enum ControlMessageOwned {
/// let mut iov = [IoSliceMut::new(&mut buffer)];
/// let r = recvmsg::<SockaddrIn>(in_socket.as_raw_fd(), &mut iov, Some(&mut cmsgspace), flags)
/// .unwrap();
/// let rtime = match r.cmsgs().next() {
/// let rtime = match r.cmsgs().unwrap().next() {
/// Some(ControlMessageOwned::ScmTimestamp(rtime)) => rtime,
/// Some(_) => panic!("Unexpected control message"),
/// None => panic!("No control message")
Expand Down
64 changes: 39 additions & 25 deletions test/sys/test_socket.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -55,7 +55,7 @@ pub fn test_timestamping() {
.unwrap();

let mut ts = None;
for c in recv.cmsgs() {
for c in recv.cmsgs().unwrap() {
if let ControlMessageOwned::ScmTimestampsns(timestamps) = c {
ts = Some(timestamps.system);
}
Expand Down Expand Up @@ -117,7 +117,7 @@ pub fn test_timestamping_realtime() {
.unwrap();

let mut ts = None;
for c in recv.cmsgs() {
for c in recv.cmsgs().unwrap() {
if let ControlMessageOwned::ScmRealtime(timeval) = c {
ts = Some(timeval);
}
Expand Down Expand Up @@ -179,7 +179,7 @@ pub fn test_timestamping_monotonic() {
.unwrap();

let mut ts = None;
for c in recv.cmsgs() {
for c in recv.cmsgs().unwrap() {
if let ControlMessageOwned::ScmMonotonic(timeval) = c {
ts = Some(timeval);
}
Expand Down Expand Up @@ -889,7 +889,7 @@ pub fn test_scm_rights() {
)
.unwrap();

for cmsg in msg.cmsgs() {
for cmsg in msg.cmsgs().unwrap() {
if let ControlMessageOwned::ScmRights(fd) = cmsg {
assert_eq!(received_r, None);
assert_eq!(fd.len(), 1);
Expand Down Expand Up @@ -1330,7 +1330,7 @@ fn test_scm_rights_single_cmsg_multiple_fds() {
.flags
.intersects(MsgFlags::MSG_TRUNC | MsgFlags::MSG_CTRUNC));

let mut cmsgs = msg.cmsgs();
let mut cmsgs = msg.cmsgs().unwrap();
match cmsgs.next() {
Some(ControlMessageOwned::ScmRights(fds)) => {
assert_eq!(
Expand Down Expand Up @@ -1399,7 +1399,7 @@ pub fn test_sendmsg_empty_cmsgs() {
)
.unwrap();

if msg.cmsgs().next().is_some() {
if msg.cmsgs().unwrap().next().is_some() {
panic!("unexpected cmsg");
}
assert!(!msg
Expand Down Expand Up @@ -1466,7 +1466,7 @@ fn test_scm_credentials() {
.unwrap();
let mut received_cred = None;

for cmsg in msg.cmsgs() {
for cmsg in msg.cmsgs().unwrap() {
let cred = match cmsg {
#[cfg(linux_android)]
ControlMessageOwned::ScmCredentials(cred) => cred,
Expand Down Expand Up @@ -1497,7 +1497,7 @@ fn test_scm_credentials() {
#[test]
fn test_scm_credentials_and_rights() {
let space = cmsg_space!(libc::ucred, RawFd);
test_impl_scm_credentials_and_rights(space);
test_impl_scm_credentials_and_rights(space).unwrap();
}

/// Ensure that passing a an oversized control message buffer to recvmsg
Expand All @@ -1509,11 +1509,23 @@ fn test_scm_credentials_and_rights() {
#[test]
fn test_too_large_cmsgspace() {
let space = vec![0u8; 1024];
test_impl_scm_credentials_and_rights(space);
test_impl_scm_credentials_and_rights(space).unwrap();
}

#[cfg(linux_android)]
fn test_impl_scm_credentials_and_rights(mut space: Vec<u8>) {
#[test]
fn test_too_small_cmsgspace() {
let space = vec![0u8; 4];
assert_eq!(
test_impl_scm_credentials_and_rights(space),
Err(nix::errno::Errno::ENOBUFS)
);
}

#[cfg(linux_android)]
fn test_impl_scm_credentials_and_rights(
mut space: Vec<u8>,
) -> Result<(), nix::errno::Errno> {
use libc::ucred;
use nix::sys::socket::sockopt::PassCred;
use nix::sys::socket::{
Expand Down Expand Up @@ -1573,9 +1585,9 @@ fn test_impl_scm_credentials_and_rights(mut space: Vec<u8>) {
.unwrap();
let mut received_cred = None;

assert_eq!(msg.cmsgs().count(), 2, "expected 2 cmsgs");
assert_eq!(msg.cmsgs()?.count(), 2, "expected 2 cmsgs");

for cmsg in msg.cmsgs() {
for cmsg in msg.cmsgs()? {
match cmsg {
ControlMessageOwned::ScmRights(fds) => {
assert_eq!(received_r, None, "already received fd");
Expand Down Expand Up @@ -1606,6 +1618,8 @@ fn test_impl_scm_credentials_and_rights(mut space: Vec<u8>) {
read(received_r.as_raw_fd(), &mut buf).unwrap();
assert_eq!(&buf[..], b"world");
close(received_r).unwrap();

Ok(())
}

// Test creating and using named unix domain sockets
Expand Down Expand Up @@ -1837,7 +1851,7 @@ pub fn test_recv_ipv4pktinfo() {
.flags
.intersects(MsgFlags::MSG_TRUNC | MsgFlags::MSG_CTRUNC));

let mut cmsgs = msg.cmsgs();
let mut cmsgs = msg.cmsgs().unwrap();
if let Some(ControlMessageOwned::Ipv4PacketInfo(pktinfo)) = cmsgs.next()
{
let i = if_nametoindex(lo_name.as_bytes()).expect("if_nametoindex");
Expand Down Expand Up @@ -1929,11 +1943,11 @@ pub fn test_recvif() {
assert!(!msg
.flags
.intersects(MsgFlags::MSG_TRUNC | MsgFlags::MSG_CTRUNC));
assert_eq!(msg.cmsgs().count(), 2, "expected 2 cmsgs");
assert_eq!(msg.cmsgs().unwrap().count(), 2, "expected 2 cmsgs");

let mut rx_recvif = false;
let mut rx_recvdstaddr = false;
for cmsg in msg.cmsgs() {
for cmsg in msg.cmsgs().unwrap() {
match cmsg {
ControlMessageOwned::Ipv4RecvIf(dl) => {
rx_recvif = true;
Expand Down Expand Up @@ -2027,10 +2041,10 @@ pub fn test_recvif_ipv4() {
assert!(!msg
.flags
.intersects(MsgFlags::MSG_TRUNC | MsgFlags::MSG_CTRUNC));
assert_eq!(msg.cmsgs().count(), 1, "expected 1 cmsgs");
assert_eq!(msg.cmsgs().unwrap().count(), 1, "expected 1 cmsgs");

let mut rx_recvorigdstaddr = false;
for cmsg in msg.cmsgs() {
for cmsg in msg.cmsgs().unwrap() {
match cmsg {
ControlMessageOwned::Ipv4OrigDstAddr(addr) => {
rx_recvorigdstaddr = true;
Expand Down Expand Up @@ -2113,10 +2127,10 @@ pub fn test_recvif_ipv6() {
assert!(!msg
.flags
.intersects(MsgFlags::MSG_TRUNC | MsgFlags::MSG_CTRUNC));
assert_eq!(msg.cmsgs().count(), 1, "expected 1 cmsgs");
assert_eq!(msg.cmsgs().unwrap().count(), 1, "expected 1 cmsgs");

let mut rx_recvorigdstaddr = false;
for cmsg in msg.cmsgs() {
for cmsg in msg.cmsgs().unwrap() {
match cmsg {
ControlMessageOwned::Ipv6OrigDstAddr(addr) => {
rx_recvorigdstaddr = true;
Expand Down Expand Up @@ -2214,7 +2228,7 @@ pub fn test_recv_ipv6pktinfo() {
.flags
.intersects(MsgFlags::MSG_TRUNC | MsgFlags::MSG_CTRUNC));

let mut cmsgs = msg.cmsgs();
let mut cmsgs = msg.cmsgs().unwrap();
if let Some(ControlMessageOwned::Ipv6PacketInfo(pktinfo)) = cmsgs.next()
{
let i = if_nametoindex(lo_name.as_bytes()).expect("if_nametoindex");
Expand Down Expand Up @@ -2357,7 +2371,7 @@ fn test_recvmsg_timestampns() {
flags,
)
.unwrap();
let rtime = match r.cmsgs().next() {
let rtime = match r.cmsgs().unwrap().next() {
Some(ControlMessageOwned::ScmTimestampns(rtime)) => rtime,
Some(_) => panic!("Unexpected control message"),
None => panic!("No control message"),
Expand Down Expand Up @@ -2418,7 +2432,7 @@ fn test_recvmmsg_timestampns() {
)
.unwrap()
.collect();
let rtime = match r[0].cmsgs().next() {
let rtime = match r[0].cmsgs().unwrap().next() {
Some(ControlMessageOwned::ScmTimestampns(rtime)) => rtime,
Some(_) => panic!("Unexpected control message"),
None => panic!("No control message"),
Expand Down Expand Up @@ -2508,7 +2522,7 @@ fn test_recvmsg_rxq_ovfl() {
MsgFlags::MSG_DONTWAIT,
) {
Ok(r) => {
drop_counter = match r.cmsgs().next() {
drop_counter = match r.cmsgs().unwrap().next() {
Some(ControlMessageOwned::RxqOvfl(drop_counter)) => {
drop_counter
}
Expand Down Expand Up @@ -2687,7 +2701,7 @@ mod linux_errqueue {
assert_eq!(msg.address, Some(sock_addr));

// Check for expected control message.
let ext_err = match msg.cmsgs().next() {
let ext_err = match msg.cmsgs().unwrap().next() {
Some(cmsg) => testf(&cmsg),
None => panic!("No control message"),
};
Expand Down Expand Up @@ -2878,7 +2892,7 @@ fn test_recvmm2() -> nix::Result<()> {
#[cfg(not(any(qemu, target_arch = "aarch64")))]
let mut saw_time = false;
let mut recvd = 0;
for cmsg in rmsg.cmsgs() {
for cmsg in rmsg.cmsgs().unwrap() {
if let ControlMessageOwned::ScmTimestampsns(timestamps) = cmsg {
let ts = timestamps.system;

Expand Down