Add new linux symbol for multicast-all

unistd: Increase maximum passwd/group buffer to 1MB

We have one UNIX group that contains most of our users whose size is
about 20 kB, so `Group::from_name` is failing with ERANGE.

The discussion on PR nix-rust#864 suggests that 1 MB is a reasonable maximum -
it follows what FreeBSD's libc does. (glibc appears to have no maximum
on the _r function and will just double the buffer until malloc fails,
but that's not particularly Rusty.)

Use memoffset::offset_of instead of homegrown macro

The homegrown macro was fine in 2016, but at some point it technically
became UB.  The memoffset crate does the same thing, but avoids UB when
using rustc 1.51.0 or later.

Fixes nix-rust#1415

Check all tests in CI

Travis didn't compile check tests on platforms that couldn't run tests
in CI, so they bitrotted.  Let's see how bad they are.

Most annoyingly, 32-bit Android defines mode_t as 16 bits, but
stat.st_mode as 32-bits.

Fix spurious errors using `sendmmsg` with multiple cmsgs

Before this fix, the buffer that holds cmsgs may move due to the resize()
call. That causes msg_hdr pointing to invalid memory, which ends up
breaking the sendmmsg() call, resulting in EINVAL.

This change fixes it by avoiding re-allocating the buffers.

Support TIMESTAMPNS for linux

.cirrus.yml

@@ -22,6 +22,7 @@ task:
     - cargo test --target i686-unknown-freebsd
   before_cache_script: rm -rf $CARGO_HOME/registry/index
 
+# Test OSX and iOS in a full VM
 task:
   matrix:
     - name: OSX x86_64
@@ -162,24 +163,20 @@ task:
     - name: Linux x32
       env:
         TARGET: x86_64-unknown-linux-gnux32
-        CHECK_TESTS: true
     - name: NetBSD x86_64
       env:
         TARGET: x86_64-unknown-netbsd
     - name: Fuchsia x86_64
       env:
         TARGET: x86_64-fuchsia
-        CHECK_TESTS: true
   container:
     image: rust:1.40
   setup_script:
     - rustup target add $TARGET
   script:
     - cargo +$TOOLCHAIN check --target $TARGET
     - cargo +$TOOLCHAIN check --target $TARGET --release
-    - 'if [ "$CHECK_TESTS" == true ]; then cargo +$TOOLCHAIN check --all-targets --target $TARGET; fi'
-    # TODO: check the tests, too.  The old Travis CI setup didn't do that, so
-    # they don't build on all platforms.
+    - cargo +$TOOLCHAIN check --all-targets --target $TARGET
   before_cache_script: rm -rf $CARGO_HOME/registry/index
 
 # illumos toolchain isn't available via rustup until 1.50

CHANGELOG.md

@@ -5,6 +5,10 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased] - ReleaseDate
 ### Added
+- Add new symbol for linux IP_MULTICAST_ALL
+  (#[]())
+- Added TIMESTAMPNS support for linux
+  (#[1402](https://github.com/nix-rust/nix/pull/1402))
 
 ### Changed
 - Made `forkpty` unsafe, like `fork`
@@ -13,6 +17,8 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 ### Fixed
 - Allow `sockaddr_ll` size, as reported by the Linux kernel, to be smaller then it's definition
   (#[1395](https://github.com/nix-rust/nix/pull/1395))
+- Fix spurious errors using `sendmmsg` with multiple cmsgs
+  (#[1414](https://github.com/nix-rust/nix/pull/1414))
 
 ### Removed
 

Cargo.toml

@@ -32,10 +32,13 @@ targets = [
 ]
 
 [dependencies]
-libc = { version = "0.2.82", features = [ "extra_traits" ] }
+libc = { version = "0.2.93", features = [ "extra_traits" ] }
 bitflags = "1.1"
 cfg-if = "1.0"
 
+[target.'cfg(not(target_os = "redox"))'.dependencies]
+memoffset = "0.6.3"
+
 [target.'cfg(target_os = "dragonfly")'.build-dependencies]
 cc = "1"
 

src/macros.rs

@@ -203,16 +203,3 @@ macro_rules! libc_enum {
         }
     };
 }
-
-/// A Rust version of the familiar C `offset_of` macro.  It returns the byte
-/// offset of `field` within struct `ty`
-#[cfg(not(target_os = "redox"))]
-macro_rules! offset_of {
-    ($ty:ty, $field:ident) => {{
-        // Safe because we don't actually read from the dereferenced pointer
-        #[allow(unused_unsafe)] // for when the macro is used in an unsafe block
-        unsafe {
-            &(*(ptr::null() as *const $ty)).$field as *const _ as usize
-        }
-    }}
-}

src/sys/socket/addr.rs

@@ -1,6 +1,7 @@
 use super::sa_family_t;
 use crate::{Error, Result, NixPath};
 use crate::errno::Errno;
+use memoffset::offset_of;
 use std::{fmt, mem, net, ptr, slice};
 use std::ffi::OsStr;
 use std::hash::{Hash, Hasher};

src/sys/socket/mod.rs

@@ -5,8 +5,11 @@ use cfg_if::cfg_if;
 use crate::{Error, Result, errno::Errno};
 use libc::{self, c_void, c_int, iovec, socklen_t, size_t,
         CMSG_FIRSTHDR, CMSG_NXTHDR, CMSG_DATA, CMSG_LEN};
+use memoffset::offset_of;
 use std::{mem, ptr, slice};
 use std::os::unix::io::RawFd;
+#[cfg(all(target_os = "linux"))]
+use crate::sys::time::TimeSpec;
 use crate::sys::time::TimeVal;
 use crate::sys::uio::IoVec;
 
@@ -554,6 +557,11 @@ pub enum ControlMessageOwned {
     /// # }
     /// ```
     ScmTimestamp(TimeVal),
+    /// Nanoseconds resolution timestamp
+    ///
+    /// [Further reading](https://www.kernel.org/doc/html/latest/networking/timestamping.html)
+    #[cfg(all(target_os = "linux"))]
+    ScmTimestampns(TimeSpec),
     #[cfg(any(
         target_os = "android",
         target_os = "ios",
@@ -645,6 +653,11 @@ impl ControlMessageOwned {
                 let tv: libc::timeval = ptr::read_unaligned(p as *const _);
                 ControlMessageOwned::ScmTimestamp(TimeVal::from(tv))
             },
+            #[cfg(all(target_os = "linux"))]
+            (libc::SOL_SOCKET, libc::SCM_TIMESTAMPNS) => {
+                let ts: libc::timespec = ptr::read_unaligned(p as *const _);
+                ControlMessageOwned::ScmTimestampns(TimeSpec::from(ts))
+            }
             #[cfg(any(
                 target_os = "android",
                 target_os = "freebsd",
@@ -1101,23 +1114,22 @@ pub fn sendmmsg<'a, I, C>(
 
     let mut output = Vec::<libc::mmsghdr>::with_capacity(reserve_items);
 
-    let mut cmsgs_buffer = vec![0u8; 0];
+    let mut cmsgs_buffers = Vec::<Vec<u8>>::with_capacity(reserve_items);
 
     for d in iter {
-        let cmsgs_start = cmsgs_buffer.len();
-        let cmsgs_required_capacity: usize = d.cmsgs.as_ref().iter().map(|c| c.space()).sum();
-        let cmsgs_buffer_need_capacity = cmsgs_start + cmsgs_required_capacity;
-        cmsgs_buffer.resize(cmsgs_buffer_need_capacity, 0);
+        let capacity: usize = d.cmsgs.as_ref().iter().map(|c| c.space()).sum();
+        let mut cmsgs_buffer = vec![0u8; capacity];
 
         output.push(libc::mmsghdr {
             msg_hdr: pack_mhdr_to_send(
-                &mut cmsgs_buffer[cmsgs_start..],
+                &mut cmsgs_buffer,
                 &d.iov,
                 &d.cmsgs,
                 d.addr.as_ref()
             ),
             msg_len: 0,
         });
+        cmsgs_buffers.push(cmsgs_buffer);
     };
 
     let ret = unsafe { libc::sendmmsg(fd, output.as_mut_ptr(), output.len() as _, flags.bits() as _) };

src/sys/socket/sockopt.rs

@@ -238,6 +238,8 @@ cfg_if! {
 }
 sockopt_impl!(Both, IpMulticastTtl, libc::IPPROTO_IP, libc::IP_MULTICAST_TTL, u8);
 sockopt_impl!(Both, IpMulticastLoop, libc::IPPROTO_IP, libc::IP_MULTICAST_LOOP, bool);
+[cfg(any(target_os = "linux", target_os = "android"))]
+sockopt_impl!(Both, IpMulticastAll, libc::IPPROTO_IP, libc::IP_MULTICAST_ALL, bool);
 sockopt_impl!(Both, ReceiveTimeout, libc::SOL_SOCKET, libc::SO_RCVTIMEO, TimeVal);
 sockopt_impl!(Both, SendTimeout, libc::SOL_SOCKET, libc::SO_SNDTIMEO, TimeVal);
 sockopt_impl!(Both, Broadcast, libc::SOL_SOCKET, libc::SO_BROADCAST, bool);
@@ -272,6 +274,8 @@ sockopt_impl!(Both, BindToDevice, libc::SOL_SOCKET, libc::SO_BINDTODEVICE, OsStr
 #[cfg(any(target_os = "android", target_os = "linux"))]
 sockopt_impl!(GetOnly, OriginalDst, libc::SOL_IP, libc::SO_ORIGINAL_DST, libc::sockaddr_in);
 sockopt_impl!(Both, ReceiveTimestamp, libc::SOL_SOCKET, libc::SO_TIMESTAMP, bool);
+#[cfg(all(target_os = "linux"))]
+sockopt_impl!(Both, ReceiveTimestampns, libc::SOL_SOCKET, libc::SO_TIMESTAMPNS, bool);
 #[cfg(any(target_os = "android", target_os = "linux"))]
 sockopt_impl!(Both, IpTransparent, libc::SOL_IP, libc::IP_TRANSPARENT, bool);
 #[cfg(target_os = "openbsd")]

src/unistd.rs

@@ -2641,10 +2641,10 @@ impl User {
               libc::size_t,
               *mut *mut libc::passwd) -> libc::c_int
     {
-        let buflimit = 16384;
+        let buflimit = 1048576;
         let bufsize = match sysconf(SysconfVar::GETPW_R_SIZE_MAX) {
             Ok(Some(n)) => n as usize,
-            Ok(None) | Err(_) => buflimit as usize,
+            Ok(None) | Err(_) => 16384,
         };
 
         let mut cbuf = Vec::with_capacity(bufsize);
@@ -2762,10 +2762,10 @@ impl Group {
               libc::size_t,
               *mut *mut libc::group) -> libc::c_int
     {
-        let buflimit = 16384;
+        let buflimit = 1048576;
         let bufsize = match sysconf(SysconfVar::GETGR_R_SIZE_MAX) {
             Ok(Some(n)) => n as usize,
-            Ok(None) | Err(_) => buflimit as usize,
+            Ok(None) | Err(_) => 16384,
         };
 
         let mut cbuf = Vec::with_capacity(bufsize);

test/sys/mod.rs

@@ -41,5 +41,5 @@ mod test_pthread;
           target_os = "netbsd",
           target_os = "openbsd"))]
 mod test_ptrace;
-#[cfg(any(target_os = "android", target_os = "linux"))]
+#[cfg(target_os = "linux")]
 mod test_timerfd;

test/sys/test_socket.rs

@@ -757,6 +757,7 @@ pub fn test_af_alg_aead() {
         target_os = "netbsd"))]
 #[test]
 pub fn test_sendmsg_ipv4packetinfo() {
+    use cfg_if::cfg_if;
     use nix::sys::uio::IoVec;
     use nix::sys::socket::{socket, sendmsg, bind,
                            AddressFamily, SockType, SockFlag, SockAddr,
@@ -778,11 +779,21 @@ pub fn test_sendmsg_ipv4packetinfo() {
     let iov = [IoVec::from_slice(&slice)];
 
     if let InetAddr::V4(sin) = inet_addr {
-        let pi = libc::in_pktinfo {
-            ipi_ifindex: 0, /* Unspecified interface */
-            ipi_addr: libc::in_addr { s_addr: 0 },
-            ipi_spec_dst: sin.sin_addr,
-        };
+        cfg_if! {
+            if #[cfg(target_os = "netbsd")] {
+                drop(sin);
+                let pi = libc::in_pktinfo {
+                    ipi_ifindex: 0, /* Unspecified interface */
+                    ipi_addr: libc::in_addr { s_addr: 0 },
+                };
+            } else {
+                let pi = libc::in_pktinfo {
+                    ipi_ifindex: 0, /* Unspecified interface */
+                    ipi_addr: libc::in_addr { s_addr: 0 },
+                    ipi_spec_dst: sin.sin_addr,
+                };
+            }
+        }
 
         let cmsg = [ControlMessage::Ipv4PacketInfo(&pi)];
 
@@ -1472,13 +1483,13 @@ pub fn test_recv_ipv6pktinfo() {
             Some(ControlMessageOwned::Ipv6PacketInfo(pktinfo)) => {
                 let i = if_nametoindex(lo_name.as_bytes()).expect("if_nametoindex");
                 assert_eq!(
-                    pktinfo.ipi6_ifindex,
+                    pktinfo.ipi6_ifindex as libc::c_uint,
                     i,
                     "unexpected ifindex (expected {}, got {})",
                     i,
                     pktinfo.ipi6_ifindex
                 );
-            }
+            },
             _ => (),
         }
         assert!(cmsgs.next().is_none(), "unexpected additional control msg");
@@ -1535,3 +1546,111 @@ pub fn test_vsock() {
     close(s1).unwrap();
     thr.join().unwrap();
 }
+
+// Disable the test on emulated platforms because it fails in Cirrus-CI.  Lack of QEMU
+// support is suspected.
+#[cfg_attr(not(any(target_arch = "x86_64")), ignore)]
+#[cfg(all(target_os = "linux"))]
+#[test]
+fn test_recvmsg_timestampns() {
+    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::ReceiveTimestampns, &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 = nix::cmsg_space!(TimeSpec);
+    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(ControlMessageOwned::ScmTimestampns(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_nsec() as u32);
+    assert!(time0.duration_since(UNIX_EPOCH).unwrap() <= rduration);
+    assert!(rduration <= time1.duration_since(UNIX_EPOCH).unwrap());
+    // Close socket
+    nix::unistd::close(in_socket).unwrap();
+}
+
+// Disable the test on emulated platforms because it fails in Cirrus-CI.  Lack of QEMU
+// support is suspected.
+#[cfg_attr(not(any(target_arch = "x86_64")), ignore)]
+#[cfg(all(target_os = "linux"))]
+#[test]
+fn test_recvmmsg_timestampns() {
+    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::ReceiveTimestampns, &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 = nix::cmsg_space!(TimeSpec);
+    let iov = [IoVec::from_mut_slice(&mut buffer)];
+    let mut data = vec![
+        RecvMmsgData {
+            iov,
+            cmsg_buffer: Some(&mut cmsgspace),
+        },
+    ];
+    let r = recvmmsg(in_socket, &mut data, flags, None).unwrap();
+    let rtime = match r[0].cmsgs().next() {
+        Some(ControlMessageOwned::ScmTimestampns(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_nsec() as u32);
+    assert!(time0.duration_since(UNIX_EPOCH).unwrap() <= rduration);
+    assert!(rduration <= time1.duration_since(UNIX_EPOCH).unwrap());
+    // Close socket
+    nix::unistd::close(in_socket).unwrap();
+}