Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2628 insertions, 0 deletions

diff --git a/third_party/rust/nix/test/sys/test_socket.rs b/third_party/rust/nix/test/sys/test_socket.rs
new file mode 100644
index 0000000000..5adc77ed6b
--- /dev/null
+++ b/third_party/rust/nix/test/sys/test_socket.rs
@@ -0,0 +1,2628 @@
+#[cfg(any(target_os = "linux", target_os = "android"))]
+use crate::*;
+use libc::{c_char, sockaddr_storage};
+#[allow(deprecated)]
+use nix::sys::socket::InetAddr;
+use nix::sys::socket::{
+    getsockname, sockaddr, sockaddr_in6, AddressFamily, UnixAddr,
+};
+use std::collections::hash_map::DefaultHasher;
+use std::hash::{Hash, Hasher};
+use std::mem::{self, MaybeUninit};
+use std::net::{self, Ipv6Addr, SocketAddr, SocketAddrV4, SocketAddrV6};
+use std::os::unix::io::RawFd;
+use std::path::Path;
+use std::slice;
+use std::str::FromStr;
+
+#[allow(deprecated)]
+#[test]
+pub fn test_inetv4_addr_to_sock_addr() {
+    let actual: net::SocketAddr = FromStr::from_str("127.0.0.1:3000").unwrap();
+    let addr = InetAddr::from_std(&actual);
+
+    match addr {
+        InetAddr::V4(addr) => {
+            let ip: u32 = 0x7f00_0001;
+            let port: u16 = 3000;
+            let saddr = addr.sin_addr.s_addr;
+
+            assert_eq!(saddr, ip.to_be());
+            assert_eq!(addr.sin_port, port.to_be());
+        }
+        _ => panic!("nope"),
+    }
+
+    assert_eq!(addr.to_string(), "127.0.0.1:3000");
+
+    let inet = addr.to_std();
+    assert_eq!(actual, inet);
+}
+
+#[allow(deprecated)]
+#[test]
+pub fn test_inetv4_addr_roundtrip_sockaddr_storage_to_addr() {
+    use nix::sys::socket::{sockaddr_storage_to_addr, SockAddr};
+
+    let actual: net::SocketAddr = FromStr::from_str("127.0.0.1:3000").unwrap();
+    let addr = InetAddr::from_std(&actual);
+    let sockaddr = SockAddr::new_inet(addr);
+
+    let (storage, ffi_size) = {
+        let mut storage = MaybeUninit::<sockaddr_storage>::zeroed();
+        let storage_ptr = storage.as_mut_ptr().cast::<sockaddr>();
+        let (ffi_ptr, ffi_size) = sockaddr.as_ffi_pair();
+        assert_eq!(mem::size_of::<sockaddr>(), ffi_size as usize);
+        unsafe {
+            storage_ptr.copy_from_nonoverlapping(ffi_ptr as *const sockaddr, 1);
+            (storage.assume_init(), ffi_size)
+        }
+    };
+
+    let from_storage =
+        sockaddr_storage_to_addr(&storage, ffi_size as usize).unwrap();
+    assert_eq!(from_storage, sockaddr);
+    let from_storage =
+        sockaddr_storage_to_addr(&storage, mem::size_of::<sockaddr_storage>())
+            .unwrap();
+    assert_eq!(from_storage, sockaddr);
+}
+
+#[cfg(any(target_os = "linux"))]
+#[cfg_attr(qemu, ignore)]
+#[test]
+pub fn test_timestamping() {
+    use nix::sys::socket::{
+        recvmsg, sendmsg, setsockopt, socket, sockopt::Timestamping,
+        ControlMessageOwned, MsgFlags, SockFlag, SockType, SockaddrIn,
+        TimestampingFlag,
+    };
+    use std::io::{IoSlice, IoSliceMut};
+
+    let sock_addr = SockaddrIn::from_str("127.0.0.1:6790").unwrap();
+
+    let ssock = socket(
+        AddressFamily::Inet,
+        SockType::Datagram,
+        SockFlag::empty(),
+        None,
+    )
+    .expect("send socket failed");
+
+    let rsock = socket(
+        AddressFamily::Inet,
+        SockType::Datagram,
+        SockFlag::empty(),
+        None,
+    )
+    .unwrap();
+    nix::sys::socket::bind(rsock, &sock_addr).unwrap();
+
+    setsockopt(rsock, Timestamping, &TimestampingFlag::all()).unwrap();
+
+    let sbuf = [0u8; 2048];
+    let mut rbuf = [0u8; 2048];
+    let flags = MsgFlags::empty();
+    let iov1 = [IoSlice::new(&sbuf)];
+    let mut iov2 = [IoSliceMut::new(&mut rbuf)];
+
+    let mut cmsg = cmsg_space!(nix::sys::socket::Timestamps);
+    sendmsg(ssock, &iov1, &[], flags, Some(&sock_addr)).unwrap();
+    let recv = recvmsg::<()>(rsock, &mut iov2, Some(&mut cmsg), flags).unwrap();
+
+    let mut ts = None;
+    for c in recv.cmsgs() {
+        if let ControlMessageOwned::ScmTimestampsns(timestamps) = c {
+            ts = Some(timestamps.system);
+        }
+    }
+    let ts = ts.expect("ScmTimestampns is present");
+    let sys_time =
+        ::nix::time::clock_gettime(::nix::time::ClockId::CLOCK_REALTIME)
+            .unwrap();
+    let diff = if ts > sys_time {
+        ts - sys_time
+    } else {
+        sys_time - ts
+    };
+    assert!(std::time::Duration::from(diff).as_secs() < 60);
+}
+
+#[allow(deprecated)]
+#[test]
+pub fn test_inetv6_addr_roundtrip_sockaddr_storage_to_addr() {
+    use nix::sys::socket::{sockaddr_storage_to_addr, SockAddr};
+
+    let port: u16 = 3000;
+    let flowinfo: u32 = 1;
+    let scope_id: u32 = 2;
+    let ip: Ipv6Addr = "fe80::1".parse().unwrap();
+
+    let actual =
+        SocketAddr::V6(SocketAddrV6::new(ip, port, flowinfo, scope_id));
+    let addr = InetAddr::from_std(&actual);
+    let sockaddr = SockAddr::new_inet(addr);
+
+    let (storage, ffi_size) = {
+        let mut storage = MaybeUninit::<sockaddr_storage>::zeroed();
+        let storage_ptr = storage.as_mut_ptr().cast::<sockaddr_in6>();
+        let (ffi_ptr, ffi_size) = sockaddr.as_ffi_pair();
+        assert_eq!(mem::size_of::<sockaddr_in6>(), ffi_size as usize);
+        unsafe {
+            storage_ptr.copy_from_nonoverlapping(
+                (ffi_ptr as *const sockaddr).cast::<sockaddr_in6>(),
+                1,
+            );
+            (storage.assume_init(), ffi_size)
+        }
+    };
+
+    let from_storage =
+        sockaddr_storage_to_addr(&storage, ffi_size as usize).unwrap();
+    assert_eq!(from_storage, sockaddr);
+    let from_storage =
+        sockaddr_storage_to_addr(&storage, mem::size_of::<sockaddr_storage>())
+            .unwrap();
+    assert_eq!(from_storage, sockaddr);
+}
+
+#[test]
+pub fn test_path_to_sock_addr() {
+    let path = "/foo/bar";
+    let actual = Path::new(path);
+    let addr = UnixAddr::new(actual).unwrap();
+
+    let expect: &[c_char] = unsafe {
+        slice::from_raw_parts(path.as_ptr() as *const c_char, path.len())
+    };
+    assert_eq!(unsafe { &(*addr.as_ptr()).sun_path[..8] }, expect);
+
+    assert_eq!(addr.path(), Some(actual));
+}
+
+fn calculate_hash<T: Hash>(t: &T) -> u64 {
+    let mut s = DefaultHasher::new();
+    t.hash(&mut s);
+    s.finish()
+}
+
+#[test]
+pub fn test_addr_equality_path() {
+    let path = "/foo/bar";
+    let actual = Path::new(path);
+    let addr1 = UnixAddr::new(actual).unwrap();
+    let mut addr2 = addr1;
+
+    unsafe { (*addr2.as_mut_ptr()).sun_path[10] = 127 };
+
+    assert_eq!(addr1, addr2);
+    assert_eq!(calculate_hash(&addr1), calculate_hash(&addr2));
+}
+
+#[cfg(any(target_os = "android", target_os = "linux"))]
+#[test]
+pub fn test_abstract_sun_path_too_long() {
+    let name = String::from("nix\0abstract\0tesnix\0abstract\0tesnix\0abstract\0tesnix\0abstract\0tesnix\0abstract\0testttttnix\0abstract\0test\0make\0sure\0this\0is\0long\0enough");
+    let addr = UnixAddr::new_abstract(name.as_bytes());
+    addr.expect_err("assertion failed");
+}
+
+#[cfg(any(target_os = "android", target_os = "linux"))]
+#[test]
+pub fn test_addr_equality_abstract() {
+    let name = String::from("nix\0abstract\0test");
+    let addr1 = UnixAddr::new_abstract(name.as_bytes()).unwrap();
+    let mut addr2 = addr1;
+
+    assert_eq!(addr1, addr2);
+    assert_eq!(calculate_hash(&addr1), calculate_hash(&addr2));
+
+    unsafe { (*addr2.as_mut_ptr()).sun_path[17] = 127 };
+    assert_ne!(addr1, addr2);
+    assert_ne!(calculate_hash(&addr1), calculate_hash(&addr2));
+}
+
+// Test getting/setting abstract addresses (without unix socket creation)
+#[cfg(any(target_os = "android", target_os = "linux"))]
+#[test]
+pub fn test_abstract_uds_addr() {
+    let empty = String::new();
+    let addr = UnixAddr::new_abstract(empty.as_bytes()).unwrap();
+    let sun_path: [u8; 0] = [];
+    assert_eq!(addr.as_abstract(), Some(&sun_path[..]));
+
+    let name = String::from("nix\0abstract\0test");
+    let addr = UnixAddr::new_abstract(name.as_bytes()).unwrap();
+    let sun_path = [
+        110u8, 105, 120, 0, 97, 98, 115, 116, 114, 97, 99, 116, 0, 116, 101,
+        115, 116,
+    ];
+    assert_eq!(addr.as_abstract(), Some(&sun_path[..]));
+    assert_eq!(addr.path(), None);
+
+    // Internally, name is null-prefixed (abstract namespace)
+    assert_eq!(unsafe { (*addr.as_ptr()).sun_path[0] }, 0);
+}
+
+// Test getting an unnamed address (without unix socket creation)
+#[cfg(any(target_os = "android", target_os = "linux"))]
+#[test]
+pub fn test_unnamed_uds_addr() {
+    use crate::nix::sys::socket::SockaddrLike;
+
+    let addr = UnixAddr::new_unnamed();
+
+    assert!(addr.is_unnamed());
+    assert_eq!(addr.len(), 2);
+    assert!(addr.path().is_none());
+    assert_eq!(addr.path_len(), 0);
+
+    assert!(addr.as_abstract().is_none());
+}
+
+#[test]
+pub fn test_getsockname() {
+    use nix::sys::socket::bind;
+    use nix::sys::socket::{socket, AddressFamily, SockFlag, SockType};
+
+    let tempdir = tempfile::tempdir().unwrap();
+    let sockname = tempdir.path().join("sock");
+    let sock = socket(
+        AddressFamily::Unix,
+        SockType::Stream,
+        SockFlag::empty(),
+        None,
+    )
+    .expect("socket failed");
+    let sockaddr = UnixAddr::new(&sockname).unwrap();
+    bind(sock, &sockaddr).expect("bind failed");
+    assert_eq!(sockaddr, getsockname(sock).expect("getsockname failed"));
+}
+
+#[test]
+pub fn test_socketpair() {
+    use nix::sys::socket::{socketpair, AddressFamily, SockFlag, SockType};
+    use nix::unistd::{read, write};
+
+    let (fd1, fd2) = socketpair(
+        AddressFamily::Unix,
+        SockType::Stream,
+        None,
+        SockFlag::empty(),
+    )
+    .unwrap();
+    write(fd1, b"hello").unwrap();
+    let mut buf = [0; 5];
+    read(fd2, &mut buf).unwrap();
+
+    assert_eq!(&buf[..], b"hello");
+}
+
+#[test]
+pub fn test_std_conversions() {
+    use nix::sys::socket::*;
+
+    let std_sa = SocketAddrV4::from_str("127.0.0.1:6789").unwrap();
+    let sock_addr = SockaddrIn::from(std_sa);
+    assert_eq!(std_sa, sock_addr.into());
+
+    let std_sa = SocketAddrV6::from_str("[::1]:6000").unwrap();
+    let sock_addr: SockaddrIn6 = SockaddrIn6::from(std_sa);
+    assert_eq!(std_sa, sock_addr.into());
+}
+
+mod recvfrom {
+    use super::*;
+    use nix::sys::socket::*;
+    use nix::{errno::Errno, Result};
+    use std::thread;
+
+    const MSG: &[u8] = b"Hello, World!";
+
+    fn sendrecv<Fs, Fr>(
+        rsock: RawFd,
+        ssock: RawFd,
+        f_send: Fs,
+        mut f_recv: Fr,
+    ) -> Option<SockaddrStorage>
+    where
+        Fs: Fn(RawFd, &[u8], MsgFlags) -> Result<usize> + Send + 'static,
+        Fr: FnMut(usize, Option<SockaddrStorage>),
+    {
+        let mut buf: [u8; 13] = [0u8; 13];
+        let mut l = 0;
+        let mut from = None;
+
+        let send_thread = thread::spawn(move || {
+            let mut l = 0;
+            while l < std::mem::size_of_val(MSG) {
+                l += f_send(ssock, &MSG[l..], MsgFlags::empty()).unwrap();
+            }
+        });
+
+        while l < std::mem::size_of_val(MSG) {
+            let (len, from_) = recvfrom(rsock, &mut buf[l..]).unwrap();
+            f_recv(len, from_);
+            from = from_;
+            l += len;
+        }
+        assert_eq!(&buf, MSG);
+        send_thread.join().unwrap();
+        from
+    }
+
+    #[test]
+    pub fn stream() {
+        let (fd2, fd1) = socketpair(
+            AddressFamily::Unix,
+            SockType::Stream,
+            None,
+            SockFlag::empty(),
+        )
+        .unwrap();
+        // Ignore from for stream sockets
+        let _ = sendrecv(fd1, fd2, send, |_, _| {});
+    }
+
+    #[test]
+    pub fn udp() {
+        let std_sa = SocketAddrV4::from_str("127.0.0.1:6789").unwrap();
+        let sock_addr = SockaddrIn::from(std_sa);
+        let rsock = socket(
+            AddressFamily::Inet,
+            SockType::Datagram,
+            SockFlag::empty(),
+            None,
+        )
+        .unwrap();
+        bind(rsock, &sock_addr).unwrap();
+        let ssock = socket(
+            AddressFamily::Inet,
+            SockType::Datagram,
+            SockFlag::empty(),
+            None,
+        )
+        .expect("send socket failed");
+        let from = sendrecv(
+            rsock,
+            ssock,
+            move |s, m, flags| sendto(s, m, &sock_addr, flags),
+            |_, _| {},
+        );
+        // UDP sockets should set the from address
+        assert_eq!(AddressFamily::Inet, from.unwrap().family().unwrap());
+    }
+
+    #[cfg(target_os = "linux")]
+    mod udp_offload {
+        use super::*;
+        use nix::sys::socket::sockopt::{UdpGroSegment, UdpGsoSegment};
+        use std::io::IoSlice;
+
+        #[test]
+        // Disable the test under emulation because it fails in Cirrus-CI.  Lack
+        // of QEMU support is suspected.
+        #[cfg_attr(qemu, ignore)]
+        pub fn gso() {
+            require_kernel_version!(udp_offload::gso, ">= 4.18");
+
+            // In this test, we send the data and provide a GSO segment size.
+            // Since we are sending the buffer of size 13, six UDP packets
+            // with size 2 and two UDP packet with size 1 will be sent.
+            let segment_size: u16 = 2;
+
+            let sock_addr = SockaddrIn::new(127, 0, 0, 1, 6791);
+            let rsock = socket(
+                AddressFamily::Inet,
+                SockType::Datagram,
+                SockFlag::empty(),
+                None,
+            )
+            .unwrap();
+
+            setsockopt(rsock, UdpGsoSegment, &(segment_size as _))
+                .expect("setsockopt UDP_SEGMENT failed");
+
+            bind(rsock, &sock_addr).unwrap();
+            let ssock = socket(
+                AddressFamily::Inet,
+                SockType::Datagram,
+                SockFlag::empty(),
+                None,
+            )
+            .expect("send socket failed");
+
+            let mut num_packets_received: i32 = 0;
+
+            sendrecv(
+                rsock,
+                ssock,
+                move |s, m, flags| {
+                    let iov = [IoSlice::new(m)];
+                    let cmsg = ControlMessage::UdpGsoSegments(&segment_size);
+                    sendmsg(s, &iov, &[cmsg], flags, Some(&sock_addr))
+                },
+                {
+                    let num_packets_received_ref = &mut num_packets_received;
+
+                    move |len, _| {
+                        // check that we receive UDP packets with payload size
+                        // less or equal to segment size
+                        assert!(len <= segment_size as usize);
+                        *num_packets_received_ref += 1;
+                    }
+                },
+            );
+
+            // Buffer size is 13, we will receive six packets of size 2,
+            // and one packet of size 1.
+            assert_eq!(7, num_packets_received);
+        }
+
+        #[test]
+        // Disable the test on emulated platforms because it fails in Cirrus-CI.
+        // Lack of QEMU support is suspected.
+        #[cfg_attr(qemu, ignore)]
+        pub fn gro() {
+            require_kernel_version!(udp_offload::gro, ">= 5.3");
+
+            // It's hard to guarantee receiving GRO packets. Just checking
+            // that `setsockopt` doesn't fail with error
+
+            let rsock = socket(
+                AddressFamily::Inet,
+                SockType::Datagram,
+                SockFlag::empty(),
+                None,
+            )
+            .unwrap();
+
+            setsockopt(rsock, UdpGroSegment, &true)
+                .expect("setsockopt UDP_GRO failed");
+        }
+    }
+
+    #[cfg(any(
+        target_os = "linux",
+        target_os = "android",
+        target_os = "freebsd",
+        target_os = "netbsd",
+    ))]
+    #[test]
+    pub fn udp_sendmmsg() {
+        use std::io::IoSlice;
+
+        let std_sa = SocketAddrV4::from_str("127.0.0.1:6793").unwrap();
+        let std_sa2 = SocketAddrV4::from_str("127.0.0.1:6794").unwrap();
+        let sock_addr = SockaddrIn::from(std_sa);
+        let sock_addr2 = SockaddrIn::from(std_sa2);
+
+        let rsock = socket(
+            AddressFamily::Inet,
+            SockType::Datagram,
+            SockFlag::empty(),
+            None,
+        )
+        .unwrap();
+        bind(rsock, &sock_addr).unwrap();
+        let ssock = socket(
+            AddressFamily::Inet,
+            SockType::Datagram,
+            SockFlag::empty(),
+            None,
+        )
+        .expect("send socket failed");
+
+        let from = sendrecv(
+            rsock,
+            ssock,
+            move |s, m, flags| {
+                let batch_size = 15;
+                let mut iovs = Vec::with_capacity(1 + batch_size);
+                let mut addrs = Vec::with_capacity(1 + batch_size);
+                let mut data = MultiHeaders::preallocate(1 + batch_size, None);
+                let iov = IoSlice::new(m);
+                // first chunk:
+                iovs.push([iov]);
+                addrs.push(Some(sock_addr));
+
+                for _ in 0..batch_size {
+                    iovs.push([iov]);
+                    addrs.push(Some(sock_addr2));
+                }
+
+                let res = sendmmsg(s, &mut data, &iovs, addrs, [], flags)?;
+                let mut sent_messages = 0;
+                let mut sent_bytes = 0;
+                for item in res {
+                    sent_messages += 1;
+                    sent_bytes += item.bytes;
+                }
+                //
+                assert_eq!(sent_messages, iovs.len());
+                assert_eq!(sent_bytes, sent_messages * m.len());
+                Ok(sent_messages)
+            },
+            |_, _| {},
+        );
+        // UDP sockets should set the from address
+        assert_eq!(AddressFamily::Inet, from.unwrap().family().unwrap());
+    }
+
+    #[cfg(any(
+        target_os = "linux",
+        target_os = "android",
+        target_os = "freebsd",
+        target_os = "netbsd",
+    ))]
+    #[test]
+    pub fn udp_recvmmsg() {
+        use nix::sys::socket::{recvmmsg, MsgFlags};
+        use std::io::IoSliceMut;
+
+        const NUM_MESSAGES_SENT: usize = 2;
+        const DATA: [u8; 2] = [1, 2];
+
+        let inet_addr = SocketAddrV4::from_str("127.0.0.1:6798").unwrap();
+        let sock_addr = SockaddrIn::from(inet_addr);
+
+        let rsock = socket(
+            AddressFamily::Inet,
+            SockType::Datagram,
+            SockFlag::empty(),
+            None,
+        )
+        .unwrap();
+        bind(rsock, &sock_addr).unwrap();
+        let ssock = socket(
+            AddressFamily::Inet,
+            SockType::Datagram,
+            SockFlag::empty(),
+            None,
+        )
+        .expect("send socket failed");
+
+        let send_thread = thread::spawn(move || {
+            for _ in 0..NUM_MESSAGES_SENT {
+                sendto(ssock, &DATA[..], &sock_addr, MsgFlags::empty())
+                    .unwrap();
+            }
+        });
+
+        let mut msgs = std::collections::LinkedList::new();
+
+        // Buffers to receive exactly `NUM_MESSAGES_SENT` messages
+        let mut receive_buffers = [[0u8; 32]; NUM_MESSAGES_SENT];
+        msgs.extend(
+            receive_buffers
+                .iter_mut()
+                .map(|buf| [IoSliceMut::new(&mut buf[..])]),
+        );
+
+        let mut data =
+            MultiHeaders::<SockaddrIn>::preallocate(msgs.len(), None);
+
+        let res: Vec<RecvMsg<SockaddrIn>> =
+            recvmmsg(rsock, &mut data, msgs.iter(), MsgFlags::empty(), None)
+                .expect("recvmmsg")
+                .collect();
+        assert_eq!(res.len(), DATA.len());
+
+        for RecvMsg { address, bytes, .. } in res.into_iter() {
+            assert_eq!(AddressFamily::Inet, address.unwrap().family().unwrap());
+            assert_eq!(DATA.len(), bytes);
+        }
+
+        for buf in &receive_buffers {
+            assert_eq!(&buf[..DATA.len()], DATA);
+        }
+
+        send_thread.join().unwrap();
+    }
+
+    #[cfg(any(
+        target_os = "linux",
+        target_os = "android",
+        target_os = "freebsd",
+        target_os = "netbsd",
+    ))]
+    #[test]
+    pub fn udp_recvmmsg_dontwait_short_read() {
+        use nix::sys::socket::{recvmmsg, MsgFlags};
+        use std::io::IoSliceMut;
+
+        const NUM_MESSAGES_SENT: usize = 2;
+        const DATA: [u8; 4] = [1, 2, 3, 4];
+
+        let inet_addr = SocketAddrV4::from_str("127.0.0.1:6799").unwrap();
+        let sock_addr = SockaddrIn::from(inet_addr);
+
+        let rsock = socket(
+            AddressFamily::Inet,
+            SockType::Datagram,
+            SockFlag::empty(),
+            None,
+        )
+        .unwrap();
+        bind(rsock, &sock_addr).unwrap();
+        let ssock = socket(
+            AddressFamily::Inet,
+            SockType::Datagram,
+            SockFlag::empty(),
+            None,
+        )
+        .expect("send socket failed");
+
+        let send_thread = thread::spawn(move || {
+            for _ in 0..NUM_MESSAGES_SENT {
+                sendto(ssock, &DATA[..], &sock_addr, MsgFlags::empty())
+                    .unwrap();
+            }
+        });
+        // Ensure we've sent all the messages before continuing so `recvmmsg`
+        // will return right away
+        send_thread.join().unwrap();
+
+        let mut msgs = std::collections::LinkedList::new();
+
+        // Buffers to receive >`NUM_MESSAGES_SENT` messages to ensure `recvmmsg`
+        // will return when there are fewer than requested messages in the
+        // kernel buffers when using `MSG_DONTWAIT`.
+        let mut receive_buffers = [[0u8; 32]; NUM_MESSAGES_SENT + 2];
+        msgs.extend(
+            receive_buffers
+                .iter_mut()
+                .map(|buf| [IoSliceMut::new(&mut buf[..])]),
+        );
+
+        let mut data = MultiHeaders::<SockaddrIn>::preallocate(
+            NUM_MESSAGES_SENT + 2,
+            None,
+        );
+
+        let res: Vec<RecvMsg<SockaddrIn>> = recvmmsg(
+            rsock,
+            &mut data,
+            msgs.iter(),
+            MsgFlags::MSG_DONTWAIT,
+            None,
+        )
+        .expect("recvmmsg")
+        .collect();
+        assert_eq!(res.len(), NUM_MESSAGES_SENT);
+
+        for RecvMsg { address, bytes, .. } in res.into_iter() {
+            assert_eq!(AddressFamily::Inet, address.unwrap().family().unwrap());
+            assert_eq!(DATA.len(), bytes);
+        }
+
+        for buf in &receive_buffers[..NUM_MESSAGES_SENT] {
+            assert_eq!(&buf[..DATA.len()], DATA);
+        }
+    }
+
+    #[test]
+    pub fn udp_inet6() {
+        let addr = std::net::Ipv6Addr::from_str("::1").unwrap();
+        let rport = 6789;
+        let rstd_sa = SocketAddrV6::new(addr, rport, 0, 0);
+        let raddr = SockaddrIn6::from(rstd_sa);
+        let sport = 6790;
+        let sstd_sa = SocketAddrV6::new(addr, sport, 0, 0);
+        let saddr = SockaddrIn6::from(sstd_sa);
+        let rsock = socket(
+            AddressFamily::Inet6,
+            SockType::Datagram,
+            SockFlag::empty(),
+            None,
+        )
+        .expect("receive socket failed");
+        match bind(rsock, &raddr) {
+            Err(Errno::EADDRNOTAVAIL) => {
+                println!("IPv6 not available, skipping test.");
+                return;
+            }
+            Err(e) => panic!("bind: {}", e),
+            Ok(()) => (),
+        }
+        let ssock = socket(
+            AddressFamily::Inet6,
+            SockType::Datagram,
+            SockFlag::empty(),
+            None,
+        )
+        .expect("send socket failed");
+        bind(ssock, &saddr).unwrap();
+        let from = sendrecv(
+            rsock,
+            ssock,
+            move |s, m, flags| sendto(s, m, &raddr, flags),
+            |_, _| {},
+        );
+        assert_eq!(AddressFamily::Inet6, from.unwrap().family().unwrap());
+        let osent_addr = from.unwrap();
+        let sent_addr = osent_addr.as_sockaddr_in6().unwrap();
+        assert_eq!(sent_addr.ip(), addr);
+        assert_eq!(sent_addr.port(), sport);
+    }
+}
+
+// Test error handling of our recvmsg wrapper
+#[test]
+pub fn test_recvmsg_ebadf() {
+    use nix::errno::Errno;
+    use nix::sys::socket::{recvmsg, MsgFlags};
+    use std::io::IoSliceMut;
+
+    let mut buf = [0u8; 5];
+    let mut iov = [IoSliceMut::new(&mut buf[..])];
+
+    let fd = -1; // Bad file descriptor
+    let r = recvmsg::<()>(fd, &mut iov, None, MsgFlags::empty());
+
+    assert_eq!(r.err().unwrap(), Errno::EBADF);
+}
+
+// Disable the test on emulated platforms due to a bug in QEMU versions <
+// 2.12.0.  https://bugs.launchpad.net/qemu/+bug/1701808
+#[cfg_attr(qemu, ignore)]
+#[test]
+pub fn test_scm_rights() {
+    use nix::sys::socket::{
+        recvmsg, sendmsg, socketpair, AddressFamily, ControlMessage,
+        ControlMessageOwned, MsgFlags, SockFlag, SockType,
+    };
+    use nix::unistd::{close, pipe, read, write};
+    use std::io::{IoSlice, IoSliceMut};
+
+    let (fd1, fd2) = socketpair(
+        AddressFamily::Unix,
+        SockType::Stream,
+        None,
+        SockFlag::empty(),
+    )
+    .unwrap();
+    let (r, w) = pipe().unwrap();
+    let mut received_r: Option<RawFd> = None;
+
+    {
+        let iov = [IoSlice::new(b"hello")];
+        let fds = [r];
+        let cmsg = ControlMessage::ScmRights(&fds);
+        assert_eq!(
+            sendmsg::<()>(fd1, &iov, &[cmsg], MsgFlags::empty(), None).unwrap(),
+            5
+        );
+        close(r).unwrap();
+        close(fd1).unwrap();
+    }
+
+    {
+        let mut buf = [0u8; 5];
+
+        let mut iov = [IoSliceMut::new(&mut buf[..])];
+        let mut cmsgspace = cmsg_space!([RawFd; 1]);
+        let msg = recvmsg::<()>(
+            fd2,
+            &mut iov,
+            Some(&mut cmsgspace),
+            MsgFlags::empty(),
+        )
+        .unwrap();
+
+        for cmsg in msg.cmsgs() {
+            if let ControlMessageOwned::ScmRights(fd) = cmsg {
+                assert_eq!(received_r, None);
+                assert_eq!(fd.len(), 1);
+                received_r = Some(fd[0]);
+            } else {
+                panic!("unexpected cmsg");
+            }
+        }
+        assert_eq!(msg.bytes, 5);
+        assert!(!msg
+            .flags
+            .intersects(MsgFlags::MSG_TRUNC | MsgFlags::MSG_CTRUNC));
+        close(fd2).unwrap();
+    }
+
+    let received_r = received_r.expect("Did not receive passed fd");
+    // Ensure that the received file descriptor works
+    write(w, b"world").unwrap();
+    let mut buf = [0u8; 5];
+    read(received_r, &mut buf).unwrap();
+    assert_eq!(&buf[..], b"world");
+    close(received_r).unwrap();
+    close(w).unwrap();
+}
+
+// Disable the test on emulated platforms due to not enabled support of AF_ALG in QEMU from rust cross
+#[cfg(any(target_os = "linux", target_os = "android"))]
+#[cfg_attr(qemu, ignore)]
+#[test]
+pub fn test_af_alg_cipher() {
+    use nix::sys::socket::sockopt::AlgSetKey;
+    use nix::sys::socket::{
+        accept, bind, sendmsg, setsockopt, socket, AddressFamily, AlgAddr,
+        ControlMessage, MsgFlags, SockFlag, SockType,
+    };
+    use nix::unistd::read;
+    use std::io::IoSlice;
+
+    skip_if_cirrus!("Fails for an unknown reason Cirrus CI.  Bug #1352");
+    // Travis's seccomp profile blocks AF_ALG
+    // https://docs.docker.com/engine/security/seccomp/
+    skip_if_seccomp!(test_af_alg_cipher);
+
+    let alg_type = "skcipher";
+    let alg_name = "ctr-aes-aesni";
+    // 256-bits secret key
+    let key = vec![0u8; 32];
+    // 16-bytes IV
+    let iv_len = 16;
+    let iv = vec![1u8; iv_len];
+    // 256-bytes plain payload
+    let payload_len = 256;
+    let payload = vec![2u8; payload_len];
+
+    let sock = socket(
+        AddressFamily::Alg,
+        SockType::SeqPacket,
+        SockFlag::empty(),
+        None,
+    )
+    .expect("socket failed");
+
+    let sockaddr = AlgAddr::new(alg_type, alg_name);
+    bind(sock, &sockaddr).expect("bind failed");
+
+    assert_eq!(sockaddr.alg_name().to_string_lossy(), alg_name);
+    assert_eq!(sockaddr.alg_type().to_string_lossy(), alg_type);
+
+    setsockopt(sock, AlgSetKey::default(), &key).expect("setsockopt");
+    let session_socket = accept(sock).expect("accept failed");
+
+    let msgs = [
+        ControlMessage::AlgSetOp(&libc::ALG_OP_ENCRYPT),
+        ControlMessage::AlgSetIv(iv.as_slice()),
+    ];
+    let iov = IoSlice::new(&payload);
+    sendmsg::<()>(session_socket, &[iov], &msgs, MsgFlags::empty(), None)
+        .expect("sendmsg encrypt");
+
+    // allocate buffer for encrypted data
+    let mut encrypted = vec![0u8; payload_len];
+    let num_bytes = read(session_socket, &mut encrypted).expect("read encrypt");
+    assert_eq!(num_bytes, payload_len);
+
+    let iov = IoSlice::new(&encrypted);
+
+    let iv = vec![1u8; iv_len];
+
+    let msgs = [
+        ControlMessage::AlgSetOp(&libc::ALG_OP_DECRYPT),
+        ControlMessage::AlgSetIv(iv.as_slice()),
+    ];
+    sendmsg::<()>(session_socket, &[iov], &msgs, MsgFlags::empty(), None)
+        .expect("sendmsg decrypt");
+
+    // allocate buffer for decrypted data
+    let mut decrypted = vec![0u8; payload_len];
+    let num_bytes = read(session_socket, &mut decrypted).expect("read decrypt");
+
+    assert_eq!(num_bytes, payload_len);
+    assert_eq!(decrypted, payload);
+}
+
+// Disable the test on emulated platforms due to not enabled support of AF_ALG
+// in QEMU from rust cross
+#[cfg(any(target_os = "linux", target_os = "android"))]
+#[cfg_attr(qemu, ignore)]
+#[test]
+pub fn test_af_alg_aead() {
+    use libc::{ALG_OP_DECRYPT, ALG_OP_ENCRYPT};
+    use nix::fcntl::{fcntl, FcntlArg, OFlag};
+    use nix::sys::socket::sockopt::{AlgSetAeadAuthSize, AlgSetKey};
+    use nix::sys::socket::{
+        accept, bind, sendmsg, setsockopt, socket, AddressFamily, AlgAddr,
+        ControlMessage, MsgFlags, SockFlag, SockType,
+    };
+    use nix::unistd::{close, read};
+    use std::io::IoSlice;
+
+    skip_if_cirrus!("Fails for an unknown reason Cirrus CI.  Bug #1352");
+    // Travis's seccomp profile blocks AF_ALG
+    // https://docs.docker.com/engine/security/seccomp/
+    skip_if_seccomp!(test_af_alg_aead);
+
+    let auth_size = 4usize;
+    let assoc_size = 16u32;
+
+    let alg_type = "aead";
+    let alg_name = "gcm(aes)";
+    // 256-bits secret key
+    let key = vec![0u8; 32];
+    // 12-bytes IV
+    let iv_len = 12;
+    let iv = vec![1u8; iv_len];
+    // 256-bytes plain payload
+    let payload_len = 256;
+    let mut payload =
+        vec![2u8; payload_len + (assoc_size as usize) + auth_size];
+
+    for i in 0..assoc_size {
+        payload[i as usize] = 10;
+    }
+
+    let len = payload.len();
+
+    for i in 0..auth_size {
+        payload[len - 1 - i] = 0;
+    }
+
+    let sock = socket(
+        AddressFamily::Alg,
+        SockType::SeqPacket,
+        SockFlag::empty(),
+        None,
+    )
+    .expect("socket failed");
+
+    let sockaddr = AlgAddr::new(alg_type, alg_name);
+    bind(sock, &sockaddr).expect("bind failed");
+
+    setsockopt(sock, AlgSetAeadAuthSize, &auth_size)
+        .expect("setsockopt AlgSetAeadAuthSize");
+    setsockopt(sock, AlgSetKey::default(), &key).expect("setsockopt AlgSetKey");
+    let session_socket = accept(sock).expect("accept failed");
+
+    let msgs = [
+        ControlMessage::AlgSetOp(&ALG_OP_ENCRYPT),
+        ControlMessage::AlgSetIv(iv.as_slice()),
+        ControlMessage::AlgSetAeadAssoclen(&assoc_size),
+    ];
+
+    let iov = IoSlice::new(&payload);
+    sendmsg::<()>(session_socket, &[iov], &msgs, MsgFlags::empty(), None)
+        .expect("sendmsg encrypt");
+
+    // allocate buffer for encrypted data
+    let mut encrypted =
+        vec![0u8; (assoc_size as usize) + payload_len + auth_size];
+    let num_bytes = read(session_socket, &mut encrypted).expect("read encrypt");
+    assert_eq!(num_bytes, payload_len + auth_size + (assoc_size as usize));
+    close(session_socket).expect("close");
+
+    for i in 0..assoc_size {
+        encrypted[i as usize] = 10;
+    }
+
+    let iov = IoSlice::new(&encrypted);
+
+    let iv = vec![1u8; iv_len];
+
+    let session_socket = accept(sock).expect("accept failed");
+
+    let msgs = [
+        ControlMessage::AlgSetOp(&ALG_OP_DECRYPT),
+        ControlMessage::AlgSetIv(iv.as_slice()),
+        ControlMessage::AlgSetAeadAssoclen(&assoc_size),
+    ];
+    sendmsg::<()>(session_socket, &[iov], &msgs, MsgFlags::empty(), None)
+        .expect("sendmsg decrypt");
+
+    // allocate buffer for decrypted data
+    let mut decrypted =
+        vec![0u8; payload_len + (assoc_size as usize) + auth_size];
+    // Starting with kernel 4.9, the interface changed slightly such that the
+    // authentication tag memory is only needed in the output buffer for encryption
+    // and in the input buffer for decryption.
+    // Do not block on read, as we may have fewer bytes than buffer size
+    fcntl(session_socket, FcntlArg::F_SETFL(OFlag::O_NONBLOCK))
+        .expect("fcntl non_blocking");
+    let num_bytes = read(session_socket, &mut decrypted).expect("read decrypt");
+
+    assert!(num_bytes >= payload_len + (assoc_size as usize));
+    assert_eq!(
+        decrypted[(assoc_size as usize)..(payload_len + (assoc_size as usize))],
+        payload[(assoc_size as usize)..payload_len + (assoc_size as usize)]
+    );
+}
+
+// Verify `ControlMessage::Ipv4PacketInfo` for `sendmsg`.
+// This creates a (udp) socket bound to localhost, then sends a message to
+// itself but uses Ipv4PacketInfo to force the source address to be localhost.
+//
+// This would be a more interesting test if we could assume that the test host
+// has more than one IP address (since we could select a different address to
+// test from).
+#[cfg(any(target_os = "linux", target_os = "macos", target_os = "netbsd"))]
+#[test]
+pub fn test_sendmsg_ipv4packetinfo() {
+    use cfg_if::cfg_if;
+    use nix::sys::socket::{
+        bind, sendmsg, socket, AddressFamily, ControlMessage, MsgFlags,
+        SockFlag, SockType, SockaddrIn,
+    };
+    use std::io::IoSlice;
+
+    let sock = socket(
+        AddressFamily::Inet,
+        SockType::Datagram,
+        SockFlag::empty(),
+        None,
+    )
+    .expect("socket failed");
+
+    let sock_addr = SockaddrIn::new(127, 0, 0, 1, 4000);
+
+    bind(sock, &sock_addr).expect("bind failed");
+
+    let slice = [1u8, 2, 3, 4, 5, 6, 7, 8];
+    let iov = [IoSlice::new(&slice)];
+
+    cfg_if! {
+        if #[cfg(target_os = "netbsd")] {
+            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: sock_addr.as_ref().sin_addr,
+            };
+        }
+    }
+
+    let cmsg = [ControlMessage::Ipv4PacketInfo(&pi)];
+
+    sendmsg(sock, &iov, &cmsg, MsgFlags::empty(), Some(&sock_addr))
+        .expect("sendmsg");
+}
+
+// Verify `ControlMessage::Ipv6PacketInfo` for `sendmsg`.
+// This creates a (udp) socket bound to ip6-localhost, then sends a message to
+// itself but uses Ipv6PacketInfo to force the source address to be
+// ip6-localhost.
+//
+// This would be a more interesting test if we could assume that the test host
+// has more than one IP address (since we could select a different address to
+// test from).
+#[cfg(any(
+    target_os = "linux",
+    target_os = "macos",
+    target_os = "netbsd",
+    target_os = "freebsd"
+))]
+#[test]
+pub fn test_sendmsg_ipv6packetinfo() {
+    use nix::errno::Errno;
+    use nix::sys::socket::{
+        bind, sendmsg, socket, AddressFamily, ControlMessage, MsgFlags,
+        SockFlag, SockType, SockaddrIn6,
+    };
+    use std::io::IoSlice;
+
+    let sock = socket(
+        AddressFamily::Inet6,
+        SockType::Datagram,
+        SockFlag::empty(),
+        None,
+    )
+    .expect("socket failed");
+
+    let std_sa = SocketAddrV6::from_str("[::1]:6000").unwrap();
+    let sock_addr: SockaddrIn6 = SockaddrIn6::from(std_sa);
+
+    if let Err(Errno::EADDRNOTAVAIL) = bind(sock, &sock_addr) {
+        println!("IPv6 not available, skipping test.");
+        return;
+    }
+
+    let slice = [1u8, 2, 3, 4, 5, 6, 7, 8];
+    let iov = [IoSlice::new(&slice)];
+
+    let pi = libc::in6_pktinfo {
+        ipi6_ifindex: 0, /* Unspecified interface */
+        ipi6_addr: sock_addr.as_ref().sin6_addr,
+    };
+
+    let cmsg = [ControlMessage::Ipv6PacketInfo(&pi)];
+
+    sendmsg::<SockaddrIn6>(
+        sock,
+        &iov,
+        &cmsg,
+        MsgFlags::empty(),
+        Some(&sock_addr),
+    )
+    .expect("sendmsg");
+}
+
+// Verify that ControlMessage::Ipv4SendSrcAddr works for sendmsg. This
+// creates a UDP socket bound to all local interfaces (0.0.0.0). It then
+// sends message to itself at 127.0.0.1 while explicitly specifying
+// 127.0.0.1 as the source address through an Ipv4SendSrcAddr
+// (IP_SENDSRCADDR) control message.
+//
+// Note that binding to 0.0.0.0 is *required* on FreeBSD; sendmsg
+// returns EINVAL otherwise. (See FreeBSD's ip(4) man page.)
+#[cfg(any(
+    target_os = "netbsd",
+    target_os = "freebsd",
+    target_os = "openbsd",
+    target_os = "dragonfly",
+))]
+#[test]
+pub fn test_sendmsg_ipv4sendsrcaddr() {
+    use nix::sys::socket::{
+        bind, sendmsg, socket, AddressFamily, ControlMessage, MsgFlags,
+        SockFlag, SockType, SockaddrIn,
+    };
+    use std::io::IoSlice;
+
+    let sock = socket(
+        AddressFamily::Inet,
+        SockType::Datagram,
+        SockFlag::empty(),
+        None,
+    )
+    .expect("socket failed");
+
+    let unspec_sock_addr = SockaddrIn::new(0, 0, 0, 0, 0);
+    bind(sock, &unspec_sock_addr).expect("bind failed");
+    let bound_sock_addr: SockaddrIn = getsockname(sock).unwrap();
+    let localhost_sock_addr: SockaddrIn =
+        SockaddrIn::new(127, 0, 0, 1, bound_sock_addr.port());
+
+    let slice = [1u8, 2, 3, 4, 5, 6, 7, 8];
+    let iov = [IoSlice::new(&slice)];
+    let cmsg = [ControlMessage::Ipv4SendSrcAddr(
+        &localhost_sock_addr.as_ref().sin_addr,
+    )];
+
+    sendmsg(
+        sock,
+        &iov,
+        &cmsg,
+        MsgFlags::empty(),
+        Some(&localhost_sock_addr),
+    )
+    .expect("sendmsg");
+}
+
+/// Tests that passing multiple fds using a single `ControlMessage` works.
+// Disable the test on emulated platforms due to a bug in QEMU versions <
+// 2.12.0.  https://bugs.launchpad.net/qemu/+bug/1701808
+#[cfg_attr(qemu, ignore)]
+#[test]
+fn test_scm_rights_single_cmsg_multiple_fds() {
+    use nix::sys::socket::{
+        recvmsg, sendmsg, ControlMessage, ControlMessageOwned, MsgFlags,
+    };
+    use std::io::{IoSlice, IoSliceMut};
+    use std::os::unix::io::{AsRawFd, RawFd};
+    use std::os::unix::net::UnixDatagram;
+    use std::thread;
+
+    let (send, receive) = UnixDatagram::pair().unwrap();
+    let thread = thread::spawn(move || {
+        let mut buf = [0u8; 8];
+        let mut iovec = [IoSliceMut::new(&mut buf)];
+
+        let mut space = cmsg_space!([RawFd; 2]);
+        let msg = recvmsg::<()>(
+            receive.as_raw_fd(),
+            &mut iovec,
+            Some(&mut space),
+            MsgFlags::empty(),
+        )
+        .unwrap();
+        assert!(!msg
+            .flags
+            .intersects(MsgFlags::MSG_TRUNC | MsgFlags::MSG_CTRUNC));
+
+        let mut cmsgs = msg.cmsgs();
+        match cmsgs.next() {
+            Some(ControlMessageOwned::ScmRights(fds)) => {
+                assert_eq!(
+                    fds.len(),
+                    2,
+                    "unexpected fd count (expected 2 fds, got {})",
+                    fds.len()
+                );
+            }
+            _ => panic!(),
+        }
+        assert!(cmsgs.next().is_none(), "unexpected control msg");
+
+        assert_eq!(msg.bytes, 8);
+        assert_eq!(*iovec[0], [1u8, 2, 3, 4, 5, 6, 7, 8]);
+    });
+
+    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 cmsg = [ControlMessage::ScmRights(&fds)];
+    sendmsg::<()>(send.as_raw_fd(), &iov, &cmsg, MsgFlags::empty(), None)
+        .unwrap();
+    thread.join().unwrap();
+}
+
+// Verify `sendmsg` builds a valid `msghdr` when passing an empty
+// `cmsgs` argument.  This should result in a msghdr with a nullptr
+// msg_control field and a msg_controllen of 0 when calling into the
+// raw `sendmsg`.
+#[test]
+pub fn test_sendmsg_empty_cmsgs() {
+    use nix::sys::socket::{
+        recvmsg, sendmsg, socketpair, AddressFamily, MsgFlags, SockFlag,
+        SockType,
+    };
+    use nix::unistd::close;
+    use std::io::{IoSlice, IoSliceMut};
+
+    let (fd1, fd2) = socketpair(
+        AddressFamily::Unix,
+        SockType::Stream,
+        None,
+        SockFlag::empty(),
+    )
+    .unwrap();
+
+    {
+        let iov = [IoSlice::new(b"hello")];
+        assert_eq!(
+            sendmsg::<()>(fd1, &iov, &[], MsgFlags::empty(), None).unwrap(),
+            5
+        );
+        close(fd1).unwrap();
+    }
+
+    {
+        let mut buf = [0u8; 5];
+        let mut iov = [IoSliceMut::new(&mut buf[..])];
+
+        let mut cmsgspace = cmsg_space!([RawFd; 1]);
+        let msg = recvmsg::<()>(
+            fd2,
+            &mut iov,
+            Some(&mut cmsgspace),
+            MsgFlags::empty(),
+        )
+        .unwrap();
+
+        for _ in msg.cmsgs() {
+            panic!("unexpected cmsg");
+        }
+        assert!(!msg
+            .flags
+            .intersects(MsgFlags::MSG_TRUNC | MsgFlags::MSG_CTRUNC));
+        assert_eq!(msg.bytes, 5);
+        close(fd2).unwrap();
+    }
+}
+
+#[cfg(any(
+    target_os = "android",
+    target_os = "linux",
+    target_os = "freebsd",
+    target_os = "dragonfly",
+))]
+#[test]
+fn test_scm_credentials() {
+    use nix::sys::socket::{
+        recvmsg, sendmsg, socketpair, AddressFamily, ControlMessage,
+        ControlMessageOwned, MsgFlags, SockFlag, SockType, UnixCredentials,
+    };
+    #[cfg(any(target_os = "android", target_os = "linux"))]
+    use nix::sys::socket::{setsockopt, sockopt::PassCred};
+    use nix::unistd::{close, getgid, getpid, getuid};
+    use std::io::{IoSlice, IoSliceMut};
+
+    let (send, recv) = socketpair(
+        AddressFamily::Unix,
+        SockType::Stream,
+        None,
+        SockFlag::empty(),
+    )
+    .unwrap();
+    #[cfg(any(target_os = "android", target_os = "linux"))]
+    setsockopt(recv, PassCred, &true).unwrap();
+
+    {
+        let iov = [IoSlice::new(b"hello")];
+        #[cfg(any(target_os = "android", target_os = "linux"))]
+        let cred = UnixCredentials::new();
+        #[cfg(any(target_os = "android", target_os = "linux"))]
+        let cmsg = ControlMessage::ScmCredentials(&cred);
+        #[cfg(any(target_os = "freebsd", target_os = "dragonfly"))]
+        let cmsg = ControlMessage::ScmCreds;
+        assert_eq!(
+            sendmsg::<()>(send, &iov, &[cmsg], MsgFlags::empty(), None)
+                .unwrap(),
+            5
+        );
+        close(send).unwrap();
+    }
+
+    {
+        let mut buf = [0u8; 5];
+        let mut iov = [IoSliceMut::new(&mut buf[..])];
+
+        let mut cmsgspace = cmsg_space!(UnixCredentials);
+        let msg = recvmsg::<()>(
+            recv,
+            &mut iov,
+            Some(&mut cmsgspace),
+            MsgFlags::empty(),
+        )
+        .unwrap();
+        let mut received_cred = None;
+
+        for cmsg in msg.cmsgs() {
+            let cred = match cmsg {
+                #[cfg(any(target_os = "android", target_os = "linux"))]
+                ControlMessageOwned::ScmCredentials(cred) => cred,
+                #[cfg(any(target_os = "freebsd", target_os = "dragonfly"))]
+                ControlMessageOwned::ScmCreds(cred) => cred,
+                other => panic!("unexpected cmsg {:?}", other),
+            };
+            assert!(received_cred.is_none());
+            assert_eq!(cred.pid(), getpid().as_raw());
+            assert_eq!(cred.uid(), getuid().as_raw());
+            assert_eq!(cred.gid(), getgid().as_raw());
+            received_cred = Some(cred);
+        }
+        received_cred.expect("no creds received");
+        assert_eq!(msg.bytes, 5);
+        assert!(!msg
+            .flags
+            .intersects(MsgFlags::MSG_TRUNC | MsgFlags::MSG_CTRUNC));
+        close(recv).unwrap();
+    }
+}
+
+/// Ensure that we can send `SCM_CREDENTIALS` and `SCM_RIGHTS` with a single
+/// `sendmsg` call.
+#[cfg(any(target_os = "android", target_os = "linux"))]
+// qemu's handling of multiple cmsgs is bugged, ignore tests under emulation
+// see https://bugs.launchpad.net/qemu/+bug/1781280
+#[cfg_attr(qemu, ignore)]
+#[test]
+fn test_scm_credentials_and_rights() {
+    let space = cmsg_space!(libc::ucred, RawFd);
+    test_impl_scm_credentials_and_rights(space);
+}
+
+/// Ensure that passing a an oversized control message buffer to recvmsg
+/// still works.
+#[cfg(any(target_os = "android", target_os = "linux"))]
+// qemu's handling of multiple cmsgs is bugged, ignore tests under emulation
+// see https://bugs.launchpad.net/qemu/+bug/1781280
+#[cfg_attr(qemu, ignore)]
+#[test]
+fn test_too_large_cmsgspace() {
+    let space = vec![0u8; 1024];
+    test_impl_scm_credentials_and_rights(space);
+}
+
+#[cfg(any(target_os = "android", target_os = "linux"))]
+fn test_impl_scm_credentials_and_rights(mut space: Vec<u8>) {
+    use libc::ucred;
+    use nix::sys::socket::sockopt::PassCred;
+    use nix::sys::socket::{
+        recvmsg, sendmsg, setsockopt, socketpair, ControlMessage,
+        ControlMessageOwned, MsgFlags, SockFlag, SockType,
+    };
+    use nix::unistd::{close, getgid, getpid, getuid, pipe, write};
+    use std::io::{IoSlice, IoSliceMut};
+
+    let (send, recv) = socketpair(
+        AddressFamily::Unix,
+        SockType::Stream,
+        None,
+        SockFlag::empty(),
+    )
+    .unwrap();
+    setsockopt(recv, PassCred, &true).unwrap();
+
+    let (r, w) = pipe().unwrap();
+    let mut received_r: Option<RawFd> = None;
+
+    {
+        let iov = [IoSlice::new(b"hello")];
+        let cred = ucred {
+            pid: getpid().as_raw(),
+            uid: getuid().as_raw(),
+            gid: getgid().as_raw(),
+        }
+        .into();
+        let fds = [r];
+        let cmsgs = [
+            ControlMessage::ScmCredentials(&cred),
+            ControlMessage::ScmRights(&fds),
+        ];
+        assert_eq!(
+            sendmsg::<()>(send, &iov, &cmsgs, MsgFlags::empty(), None).unwrap(),
+            5
+        );
+        close(r).unwrap();
+        close(send).unwrap();
+    }
+
+    {
+        let mut buf = [0u8; 5];
+        let mut iov = [IoSliceMut::new(&mut buf[..])];
+        let msg =
+            recvmsg::<()>(recv, &mut iov, Some(&mut space), MsgFlags::empty())
+                .unwrap();
+        let mut received_cred = None;
+
+        assert_eq!(msg.cmsgs().count(), 2, "expected 2 cmsgs");
+
+        for cmsg in msg.cmsgs() {
+            match cmsg {
+                ControlMessageOwned::ScmRights(fds) => {
+                    assert_eq!(received_r, None, "already received fd");
+                    assert_eq!(fds.len(), 1);
+                    received_r = Some(fds[0]);
+                }
+                ControlMessageOwned::ScmCredentials(cred) => {
+                    assert!(received_cred.is_none());
+                    assert_eq!(cred.pid(), getpid().as_raw());
+                    assert_eq!(cred.uid(), getuid().as_raw());
+                    assert_eq!(cred.gid(), getgid().as_raw());
+                    received_cred = Some(cred);
+                }
+                _ => panic!("unexpected cmsg"),
+            }
+        }
+        received_cred.expect("no creds received");
+        assert_eq!(msg.bytes, 5);
+        assert!(!msg
+            .flags
+            .intersects(MsgFlags::MSG_TRUNC | MsgFlags::MSG_CTRUNC));
+        close(recv).unwrap();
+    }
+
+    let received_r = received_r.expect("Did not receive passed fd");
+    // Ensure that the received file descriptor works
+    write(w, b"world").unwrap();
+    let mut buf = [0u8; 5];
+    read(received_r, &mut buf).unwrap();
+    assert_eq!(&buf[..], b"world");
+    close(received_r).unwrap();
+    close(w).unwrap();
+}
+
+// Test creating and using named unix domain sockets
+#[test]
+pub fn test_named_unixdomain() {
+    use nix::sys::socket::{accept, bind, connect, listen, socket, UnixAddr};
+    use nix::sys::socket::{SockFlag, SockType};
+    use nix::unistd::{close, read, write};
+    use std::thread;
+
+    let tempdir = tempfile::tempdir().unwrap();
+    let sockname = tempdir.path().join("sock");
+    let s1 = socket(
+        AddressFamily::Unix,
+        SockType::Stream,
+        SockFlag::empty(),
+        None,
+    )
+    .expect("socket failed");
+    let sockaddr = UnixAddr::new(&sockname).unwrap();
+    bind(s1, &sockaddr).expect("bind failed");
+    listen(s1, 10).expect("listen failed");
+
+    let thr = thread::spawn(move || {
+        let s2 = socket(
+            AddressFamily::Unix,
+            SockType::Stream,
+            SockFlag::empty(),
+            None,
+        )
+        .expect("socket failed");
+        connect(s2, &sockaddr).expect("connect failed");
+        write(s2, b"hello").expect("write failed");
+        close(s2).unwrap();
+    });
+
+    let s3 = accept(s1).expect("accept failed");
+
+    let mut buf = [0; 5];
+    read(s3, &mut buf).unwrap();
+    close(s3).unwrap();
+    close(s1).unwrap();
+    thr.join().unwrap();
+
+    assert_eq!(&buf[..], b"hello");
+}
+
+// Test using unnamed unix domain addresses
+#[cfg(any(target_os = "android", target_os = "linux"))]
+#[test]
+pub fn test_unnamed_unixdomain() {
+    use nix::sys::socket::{getsockname, socketpair};
+    use nix::sys::socket::{SockFlag, SockType};
+    use nix::unistd::close;
+
+    let (fd_1, fd_2) = socketpair(
+        AddressFamily::Unix,
+        SockType::Stream,
+        None,
+        SockFlag::empty(),
+    )
+    .expect("socketpair failed");
+
+    let addr_1: UnixAddr = getsockname(fd_1).expect("getsockname failed");
+    assert!(addr_1.is_unnamed());
+
+    close(fd_1).unwrap();
+    close(fd_2).unwrap();
+}
+
+// Test creating and using unnamed unix domain addresses for autobinding sockets
+#[cfg(any(target_os = "android", target_os = "linux"))]
+#[test]
+pub fn test_unnamed_unixdomain_autobind() {
+    use nix::sys::socket::{bind, getsockname, socket};
+    use nix::sys::socket::{SockFlag, SockType};
+    use nix::unistd::close;
+
+    let fd = socket(
+        AddressFamily::Unix,
+        SockType::Stream,
+        SockFlag::empty(),
+        None,
+    )
+    .expect("socket failed");
+
+    // unix(7): "If a bind(2) call specifies addrlen as `sizeof(sa_family_t)`, or [...], then the
+    // socket is autobound to an abstract address"
+    bind(fd, &UnixAddr::new_unnamed()).expect("bind failed");
+
+    let addr: UnixAddr = getsockname(fd).expect("getsockname failed");
+    let addr = addr.as_abstract().unwrap();
+
+    // changed from 8 to 5 bytes in Linux 2.3.15, and rust's minimum supported Linux version is 3.2
+    // (as of 2022-11)
+    assert_eq!(addr.len(), 5);
+
+    close(fd).unwrap();
+}
+
+// Test creating and using named system control sockets
+#[cfg(any(target_os = "macos", target_os = "ios"))]
+#[test]
+pub fn test_syscontrol() {
+    use nix::errno::Errno;
+    use nix::sys::socket::{
+        socket, SockFlag, SockProtocol, SockType, SysControlAddr,
+    };
+
+    let fd = socket(
+        AddressFamily::System,
+        SockType::Datagram,
+        SockFlag::empty(),
+        SockProtocol::KextControl,
+    )
+    .expect("socket failed");
+    SysControlAddr::from_name(fd, "com.apple.net.utun_control", 0)
+        .expect("resolving sys_control name failed");
+    assert_eq!(
+        SysControlAddr::from_name(fd, "foo.bar.lol", 0).err(),
+        Some(Errno::ENOENT)
+    );
+
+    // requires root privileges
+    // connect(fd, &sockaddr).expect("connect failed");
+}
+
+#[cfg(any(
+    target_os = "android",
+    target_os = "freebsd",
+    target_os = "ios",
+    target_os = "linux",
+    target_os = "macos",
+    target_os = "netbsd",
+    target_os = "openbsd",
+))]
+fn loopback_address(
+    family: AddressFamily,
+) -> Option<nix::ifaddrs::InterfaceAddress> {
+    use nix::ifaddrs::getifaddrs;
+    use nix::net::if_::*;
+    use nix::sys::socket::SockaddrLike;
+    use std::io;
+    use std::io::Write;
+
+    let mut addrs = match getifaddrs() {
+        Ok(iter) => iter,
+        Err(e) => {
+            let stdioerr = io::stderr();
+            let mut handle = stdioerr.lock();
+            writeln!(handle, "getifaddrs: {:?}", e).unwrap();
+            return None;
+        }
+    };
+    // return first address matching family
+    addrs.find(|ifaddr| {
+        ifaddr.flags.contains(InterfaceFlags::IFF_LOOPBACK)
+            && ifaddr.address.as_ref().and_then(SockaddrLike::family)
+                == Some(family)
+    })
+}
+
+#[cfg(any(
+    target_os = "android",
+    target_os = "ios",
+    target_os = "linux",
+    target_os = "macos",
+    target_os = "netbsd",
+))]
+// qemu doesn't seem to be emulating this correctly in these architectures
+#[cfg_attr(
+    all(
+        qemu,
+        any(
+            target_arch = "mips",
+            target_arch = "mips64",
+            target_arch = "powerpc64",
+        )
+    ),
+    ignore
+)]
+#[test]
+pub fn test_recv_ipv4pktinfo() {
+    use nix::net::if_::*;
+    use nix::sys::socket::sockopt::Ipv4PacketInfo;
+    use nix::sys::socket::{bind, SockFlag, SockType, SockaddrIn};
+    use nix::sys::socket::{getsockname, setsockopt, socket};
+    use nix::sys::socket::{recvmsg, sendmsg, ControlMessageOwned, MsgFlags};
+    use std::io::{IoSlice, IoSliceMut};
+
+    let lo_ifaddr = loopback_address(AddressFamily::Inet);
+    let (lo_name, lo) = match lo_ifaddr {
+        Some(ifaddr) => (
+            ifaddr.interface_name,
+            ifaddr.address.expect("Expect IPv4 address on interface"),
+        ),
+        None => return,
+    };
+    let receive = socket(
+        AddressFamily::Inet,
+        SockType::Datagram,
+        SockFlag::empty(),
+        None,
+    )
+    .expect("receive socket failed");
+    bind(receive, &lo).expect("bind failed");
+    let sa: SockaddrIn = getsockname(receive).expect("getsockname failed");
+    setsockopt(receive, Ipv4PacketInfo, &true).expect("setsockopt failed");
+
+    {
+        let slice = [1u8, 2, 3, 4, 5, 6, 7, 8];
+        let iov = [IoSlice::new(&slice)];
+
+        let send = socket(
+            AddressFamily::Inet,
+            SockType::Datagram,
+            SockFlag::empty(),
+            None,
+        )
+        .expect("send socket failed");
+        sendmsg(send, &iov, &[], MsgFlags::empty(), Some(&sa))
+            .expect("sendmsg failed");
+    }
+
+    {
+        let mut buf = [0u8; 8];
+        let mut iovec = [IoSliceMut::new(&mut buf)];
+
+        let mut space = cmsg_space!(libc::in_pktinfo);
+        let msg = recvmsg::<()>(
+            receive,
+            &mut iovec,
+            Some(&mut space),
+            MsgFlags::empty(),
+        )
+        .expect("recvmsg failed");
+        assert!(!msg
+            .flags
+            .intersects(MsgFlags::MSG_TRUNC | MsgFlags::MSG_CTRUNC));
+
+        let mut cmsgs = msg.cmsgs();
+        if let Some(ControlMessageOwned::Ipv4PacketInfo(pktinfo)) = cmsgs.next()
+        {
+            let i = if_nametoindex(lo_name.as_bytes()).expect("if_nametoindex");
+            assert_eq!(
+                pktinfo.ipi_ifindex as libc::c_uint, i,
+                "unexpected ifindex (expected {}, got {})",
+                i, pktinfo.ipi_ifindex
+            );
+        }
+        assert!(cmsgs.next().is_none(), "unexpected additional control msg");
+        assert_eq!(msg.bytes, 8);
+        assert_eq!(*iovec[0], [1u8, 2, 3, 4, 5, 6, 7, 8]);
+    }
+}
+
+#[cfg(any(
+    target_os = "freebsd",
+    target_os = "ios",
+    target_os = "macos",
+    target_os = "netbsd",
+    target_os = "openbsd",
+))]
+// qemu doesn't seem to be emulating this correctly in these architectures
+#[cfg_attr(
+    all(
+        qemu,
+        any(
+            target_arch = "mips",
+            target_arch = "mips64",
+            target_arch = "powerpc64",
+        )
+    ),
+    ignore
+)]
+#[test]
+pub fn test_recvif() {
+    use nix::net::if_::*;
+    use nix::sys::socket::sockopt::{Ipv4RecvDstAddr, Ipv4RecvIf};
+    use nix::sys::socket::{bind, SockFlag, SockType, SockaddrIn};
+    use nix::sys::socket::{getsockname, setsockopt, socket};
+    use nix::sys::socket::{recvmsg, sendmsg, ControlMessageOwned, MsgFlags};
+    use std::io::{IoSlice, IoSliceMut};
+
+    let lo_ifaddr = loopback_address(AddressFamily::Inet);
+    let (lo_name, lo) = match lo_ifaddr {
+        Some(ifaddr) => (
+            ifaddr.interface_name,
+            ifaddr.address.expect("Expect IPv4 address on interface"),
+        ),
+        None => return,
+    };
+    let receive = socket(
+        AddressFamily::Inet,
+        SockType::Datagram,
+        SockFlag::empty(),
+        None,
+    )
+    .expect("receive socket failed");
+    bind(receive, &lo).expect("bind failed");
+    let sa: SockaddrIn = getsockname(receive).expect("getsockname failed");
+    setsockopt(receive, Ipv4RecvIf, &true)
+        .expect("setsockopt IP_RECVIF failed");
+    setsockopt(receive, Ipv4RecvDstAddr, &true)
+        .expect("setsockopt IP_RECVDSTADDR failed");
+
+    {
+        let slice = [1u8, 2, 3, 4, 5, 6, 7, 8];
+        let iov = [IoSlice::new(&slice)];
+
+        let send = socket(
+            AddressFamily::Inet,
+            SockType::Datagram,
+            SockFlag::empty(),
+            None,
+        )
+        .expect("send socket failed");
+        sendmsg(send, &iov, &[], MsgFlags::empty(), Some(&sa))
+            .expect("sendmsg failed");
+    }
+
+    {
+        let mut buf = [0u8; 8];
+        let mut iovec = [IoSliceMut::new(&mut buf)];
+        let mut space = cmsg_space!(libc::sockaddr_dl, libc::in_addr);
+        let msg = recvmsg::<()>(
+            receive,
+            &mut iovec,
+            Some(&mut space),
+            MsgFlags::empty(),
+        )
+        .expect("recvmsg failed");
+        assert!(!msg
+            .flags
+            .intersects(MsgFlags::MSG_TRUNC | MsgFlags::MSG_CTRUNC));
+        assert_eq!(msg.cmsgs().count(), 2, "expected 2 cmsgs");
+
+        let mut rx_recvif = false;
+        let mut rx_recvdstaddr = false;
+        for cmsg in msg.cmsgs() {
+            match cmsg {
+                ControlMessageOwned::Ipv4RecvIf(dl) => {
+                    rx_recvif = true;
+                    let i = if_nametoindex(lo_name.as_bytes())
+                        .expect("if_nametoindex");
+                    assert_eq!(
+                        dl.sdl_index as libc::c_uint, i,
+                        "unexpected ifindex (expected {}, got {})",
+                        i, dl.sdl_index
+                    );
+                }
+                ControlMessageOwned::Ipv4RecvDstAddr(addr) => {
+                    rx_recvdstaddr = true;
+                    if let Some(sin) = lo.as_sockaddr_in() {
+                        assert_eq!(sin.as_ref().sin_addr.s_addr,
+                                   addr.s_addr,
+                                   "unexpected destination address (expected {}, got {})",
+                                   sin.as_ref().sin_addr.s_addr,
+                                   addr.s_addr);
+                    } else {
+                        panic!("unexpected Sockaddr");
+                    }
+                }
+                _ => panic!("unexpected additional control msg"),
+            }
+        }
+        assert!(rx_recvif);
+        assert!(rx_recvdstaddr);
+        assert_eq!(msg.bytes, 8);
+        assert_eq!(*iovec[0], [1u8, 2, 3, 4, 5, 6, 7, 8]);
+    }
+}
+
+#[cfg(any(target_os = "android", target_os = "freebsd", target_os = "linux"))]
+#[cfg_attr(qemu, ignore)]
+#[test]
+pub fn test_recvif_ipv4() {
+    use nix::sys::socket::sockopt::Ipv4OrigDstAddr;
+    use nix::sys::socket::{bind, SockFlag, SockType, SockaddrIn};
+    use nix::sys::socket::{getsockname, setsockopt, socket};
+    use nix::sys::socket::{recvmsg, sendmsg, ControlMessageOwned, MsgFlags};
+    use std::io::{IoSlice, IoSliceMut};
+
+    let lo_ifaddr = loopback_address(AddressFamily::Inet);
+    let (_lo_name, lo) = match lo_ifaddr {
+        Some(ifaddr) => (
+            ifaddr.interface_name,
+            ifaddr.address.expect("Expect IPv4 address on interface"),
+        ),
+        None => return,
+    };
+    let receive = socket(
+        AddressFamily::Inet,
+        SockType::Datagram,
+        SockFlag::empty(),
+        None,
+    )
+    .expect("receive socket failed");
+    bind(receive, &lo).expect("bind failed");
+    let sa: SockaddrIn = getsockname(receive).expect("getsockname failed");
+    setsockopt(receive, Ipv4OrigDstAddr, &true)
+        .expect("setsockopt IP_ORIGDSTADDR failed");
+
+    {
+        let slice = [1u8, 2, 3, 4, 5, 6, 7, 8];
+        let iov = [IoSlice::new(&slice)];
+
+        let send = socket(
+            AddressFamily::Inet,
+            SockType::Datagram,
+            SockFlag::empty(),
+            None,
+        )
+        .expect("send socket failed");
+        sendmsg(send, &iov, &[], MsgFlags::empty(), Some(&sa))
+            .expect("sendmsg failed");
+    }
+
+    {
+        let mut buf = [0u8; 8];
+        let mut iovec = [IoSliceMut::new(&mut buf)];
+        let mut space = cmsg_space!(libc::sockaddr_in);
+        let msg = recvmsg::<()>(
+            receive,
+            &mut iovec,
+            Some(&mut space),
+            MsgFlags::empty(),
+        )
+        .expect("recvmsg failed");
+        assert!(!msg
+            .flags
+            .intersects(MsgFlags::MSG_TRUNC | MsgFlags::MSG_CTRUNC));
+        assert_eq!(msg.cmsgs().count(), 1, "expected 1 cmsgs");
+
+        let mut rx_recvorigdstaddr = false;
+        for cmsg in msg.cmsgs() {
+            match cmsg {
+                ControlMessageOwned::Ipv4OrigDstAddr(addr) => {
+                    rx_recvorigdstaddr = true;
+                    if let Some(sin) = lo.as_sockaddr_in() {
+                        assert_eq!(sin.as_ref().sin_addr.s_addr,
+                                   addr.sin_addr.s_addr,
+                                   "unexpected destination address (expected {}, got {})",
+                                   sin.as_ref().sin_addr.s_addr,
+                                   addr.sin_addr.s_addr);
+                    } else {
+                        panic!("unexpected Sockaddr");
+                    }
+                }
+                _ => panic!("unexpected additional control msg"),
+            }
+        }
+        assert!(rx_recvorigdstaddr);
+        assert_eq!(msg.bytes, 8);
+        assert_eq!(*iovec[0], [1u8, 2, 3, 4, 5, 6, 7, 8]);
+    }
+}
+
+#[cfg(any(target_os = "android", target_os = "freebsd", target_os = "linux"))]
+#[cfg_attr(qemu, ignore)]
+#[test]
+pub fn test_recvif_ipv6() {
+    use nix::sys::socket::sockopt::Ipv6OrigDstAddr;
+    use nix::sys::socket::{bind, SockFlag, SockType, SockaddrIn6};
+    use nix::sys::socket::{getsockname, setsockopt, socket};
+    use nix::sys::socket::{recvmsg, sendmsg, ControlMessageOwned, MsgFlags};
+    use std::io::{IoSlice, IoSliceMut};
+
+    let lo_ifaddr = loopback_address(AddressFamily::Inet6);
+    let (_lo_name, lo) = match lo_ifaddr {
+        Some(ifaddr) => (
+            ifaddr.interface_name,
+            ifaddr.address.expect("Expect IPv6 address on interface"),
+        ),
+        None => return,
+    };
+    let receive = socket(
+        AddressFamily::Inet6,
+        SockType::Datagram,
+        SockFlag::empty(),
+        None,
+    )
+    .expect("receive socket failed");
+    bind(receive, &lo).expect("bind failed");
+    let sa: SockaddrIn6 = getsockname(receive).expect("getsockname failed");
+    setsockopt(receive, Ipv6OrigDstAddr, &true)
+        .expect("setsockopt IP_ORIGDSTADDR failed");
+
+    {
+        let slice = [1u8, 2, 3, 4, 5, 6, 7, 8];
+        let iov = [IoSlice::new(&slice)];
+
+        let send = socket(
+            AddressFamily::Inet6,
+            SockType::Datagram,
+            SockFlag::empty(),
+            None,
+        )
+        .expect("send socket failed");
+        sendmsg(send, &iov, &[], MsgFlags::empty(), Some(&sa))
+            .expect("sendmsg failed");
+    }
+
+    {
+        let mut buf = [0u8; 8];
+        let mut iovec = [IoSliceMut::new(&mut buf)];
+        let mut space = cmsg_space!(libc::sockaddr_in6);
+        let msg = recvmsg::<()>(
+            receive,
+            &mut iovec,
+            Some(&mut space),
+            MsgFlags::empty(),
+        )
+        .expect("recvmsg failed");
+        assert!(!msg
+            .flags
+            .intersects(MsgFlags::MSG_TRUNC | MsgFlags::MSG_CTRUNC));
+        assert_eq!(msg.cmsgs().count(), 1, "expected 1 cmsgs");
+
+        let mut rx_recvorigdstaddr = false;
+        for cmsg in msg.cmsgs() {
+            match cmsg {
+                ControlMessageOwned::Ipv6OrigDstAddr(addr) => {
+                    rx_recvorigdstaddr = true;
+                    if let Some(sin) = lo.as_sockaddr_in6() {
+                        assert_eq!(sin.as_ref().sin6_addr.s6_addr,
+                                   addr.sin6_addr.s6_addr,
+                                   "unexpected destination address (expected {:?}, got {:?})",
+                                   sin.as_ref().sin6_addr.s6_addr,
+                                   addr.sin6_addr.s6_addr);
+                    } else {
+                        panic!("unexpected Sockaddr");
+                    }
+                }
+                _ => panic!("unexpected additional control msg"),
+            }
+        }
+        assert!(rx_recvorigdstaddr);
+        assert_eq!(msg.bytes, 8);
+        assert_eq!(*iovec[0], [1u8, 2, 3, 4, 5, 6, 7, 8]);
+    }
+}
+
+#[cfg(any(
+    target_os = "android",
+    target_os = "freebsd",
+    target_os = "ios",
+    target_os = "linux",
+    target_os = "macos",
+    target_os = "netbsd",
+    target_os = "openbsd",
+))]
+// qemu doesn't seem to be emulating this correctly in these architectures
+#[cfg_attr(
+    all(
+        qemu,
+        any(
+            target_arch = "mips",
+            target_arch = "mips64",
+            target_arch = "powerpc64",
+        )
+    ),
+    ignore
+)]
+#[test]
+pub fn test_recv_ipv6pktinfo() {
+    use nix::net::if_::*;
+    use nix::sys::socket::sockopt::Ipv6RecvPacketInfo;
+    use nix::sys::socket::{bind, SockFlag, SockType, SockaddrIn6};
+    use nix::sys::socket::{getsockname, setsockopt, socket};
+    use nix::sys::socket::{recvmsg, sendmsg, ControlMessageOwned, MsgFlags};
+    use std::io::{IoSlice, IoSliceMut};
+
+    let lo_ifaddr = loopback_address(AddressFamily::Inet6);
+    let (lo_name, lo) = match lo_ifaddr {
+        Some(ifaddr) => (
+            ifaddr.interface_name,
+            ifaddr.address.expect("Expect IPv6 address on interface"),
+        ),
+        None => return,
+    };
+    let receive = socket(
+        AddressFamily::Inet6,
+        SockType::Datagram,
+        SockFlag::empty(),
+        None,
+    )
+    .expect("receive socket failed");
+    bind(receive, &lo).expect("bind failed");
+    let sa: SockaddrIn6 = getsockname(receive).expect("getsockname failed");
+    setsockopt(receive, Ipv6RecvPacketInfo, &true).expect("setsockopt failed");
+
+    {
+        let slice = [1u8, 2, 3, 4, 5, 6, 7, 8];
+        let iov = [IoSlice::new(&slice)];
+
+        let send = socket(
+            AddressFamily::Inet6,
+            SockType::Datagram,
+            SockFlag::empty(),
+            None,
+        )
+        .expect("send socket failed");
+        sendmsg(send, &iov, &[], MsgFlags::empty(), Some(&sa))
+            .expect("sendmsg failed");
+    }
+
+    {
+        let mut buf = [0u8; 8];
+        let mut iovec = [IoSliceMut::new(&mut buf)];
+
+        let mut space = cmsg_space!(libc::in6_pktinfo);
+        let msg = recvmsg::<()>(
+            receive,
+            &mut iovec,
+            Some(&mut space),
+            MsgFlags::empty(),
+        )
+        .expect("recvmsg failed");
+        assert!(!msg
+            .flags
+            .intersects(MsgFlags::MSG_TRUNC | MsgFlags::MSG_CTRUNC));
+
+        let mut cmsgs = msg.cmsgs();
+        if let Some(ControlMessageOwned::Ipv6PacketInfo(pktinfo)) = cmsgs.next()
+        {
+            let i = if_nametoindex(lo_name.as_bytes()).expect("if_nametoindex");
+            assert_eq!(
+                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");
+        assert_eq!(msg.bytes, 8);
+        assert_eq!(*iovec[0], [1u8, 2, 3, 4, 5, 6, 7, 8]);
+    }
+}
+
+#[cfg(any(target_os = "android", target_os = "linux"))]
+#[cfg_attr(graviton, ignore = "Not supported by the CI environment")]
+#[test]
+pub fn test_vsock() {
+    use nix::errno::Errno;
+    use nix::sys::socket::{
+        bind, connect, listen, socket, AddressFamily, SockFlag, SockType,
+        VsockAddr,
+    };
+    use nix::unistd::close;
+    use std::thread;
+
+    let port: u32 = 3000;
+
+    let s1 = socket(
+        AddressFamily::Vsock,
+        SockType::Stream,
+        SockFlag::empty(),
+        None,
+    )
+    .expect("socket failed");
+
+    // VMADDR_CID_HYPERVISOR is reserved, so we expect an EADDRNOTAVAIL error.
+    let sockaddr_hv = VsockAddr::new(libc::VMADDR_CID_HYPERVISOR, port);
+    assert_eq!(bind(s1, &sockaddr_hv).err(), Some(Errno::EADDRNOTAVAIL));
+
+    let sockaddr_any = VsockAddr::new(libc::VMADDR_CID_ANY, port);
+    assert_eq!(bind(s1, &sockaddr_any), Ok(()));
+    listen(s1, 10).expect("listen failed");
+
+    let thr = thread::spawn(move || {
+        let cid: u32 = libc::VMADDR_CID_HOST;
+
+        let s2 = socket(
+            AddressFamily::Vsock,
+            SockType::Stream,
+            SockFlag::empty(),
+            None,
+        )
+        .expect("socket failed");
+
+        let sockaddr_host = VsockAddr::new(cid, port);
+
+        // The current implementation does not support loopback devices, so,
+        // for now, we expect a failure on the connect.
+        assert_ne!(connect(s2, &sockaddr_host), Ok(()));
+
+        close(s2).unwrap();
+    });
+
+    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(qemu, ignore)]
+#[cfg(all(target_os = "linux"))]
+#[test]
+fn test_recvmsg_timestampns() {
+    use nix::sys::socket::*;
+    use nix::sys::time::*;
+    use std::io::{IoSlice, IoSliceMut};
+    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 = SockaddrIn::new(127, 0, 0, 1, 0);
+    bind(in_socket, &localhost).unwrap();
+    let address: SockaddrIn = getsockname(in_socket).unwrap();
+    // Get initial time
+    let time0 = SystemTime::now();
+    // Send the message
+    let iov = [IoSlice::new(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 mut iov = [IoSliceMut::new(&mut buffer)];
+    let r = recvmsg::<()>(in_socket, &mut 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(qemu, ignore)]
+#[cfg(all(target_os = "linux"))]
+#[test]
+fn test_recvmmsg_timestampns() {
+    use nix::sys::socket::*;
+    use nix::sys::time::*;
+    use std::io::{IoSlice, IoSliceMut};
+    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 = SockaddrIn::from_str("127.0.0.1:0").unwrap();
+    bind(in_socket, &localhost).unwrap();
+    let address: SockaddrIn = getsockname(in_socket).unwrap();
+    // Get initial time
+    let time0 = SystemTime::now();
+    // Send the message
+    let iov = [IoSlice::new(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 cmsgspace = nix::cmsg_space!(TimeSpec);
+    let iov = vec![[IoSliceMut::new(&mut buffer)]];
+    let mut data = MultiHeaders::preallocate(1, Some(cmsgspace));
+    let r: Vec<RecvMsg<()>> =
+        recvmmsg(in_socket, &mut data, iov.iter(), flags, None)
+            .unwrap()
+            .collect();
+    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();
+}
+
+// Disable the test on emulated platforms because it fails in Cirrus-CI.  Lack
+// of QEMU support is suspected.
+#[cfg_attr(qemu, ignore)]
+#[cfg(any(target_os = "android", target_os = "fuchsia", target_os = "linux"))]
+#[test]
+fn test_recvmsg_rxq_ovfl() {
+    use nix::sys::socket::sockopt::{RcvBuf, RxqOvfl};
+    use nix::sys::socket::*;
+    use nix::Error;
+    use std::io::{IoSlice, IoSliceMut};
+
+    let message = [0u8; 2048];
+    let bufsize = message.len() * 2;
+
+    let in_socket = socket(
+        AddressFamily::Inet,
+        SockType::Datagram,
+        SockFlag::empty(),
+        None,
+    )
+    .unwrap();
+    let out_socket = socket(
+        AddressFamily::Inet,
+        SockType::Datagram,
+        SockFlag::empty(),
+        None,
+    )
+    .unwrap();
+
+    let localhost = SockaddrIn::from_str("127.0.0.1:0").unwrap();
+    bind(in_socket, &localhost).unwrap();
+
+    let address: SockaddrIn = getsockname(in_socket).unwrap();
+    connect(out_socket, &address).unwrap();
+
+    // Set SO_RXQ_OVFL flag.
+    setsockopt(in_socket, RxqOvfl, &1).unwrap();
+
+    // Set the receiver buffer size to hold only 2 messages.
+    setsockopt(in_socket, RcvBuf, &bufsize).unwrap();
+
+    let mut drop_counter = 0;
+
+    for _ in 0..2 {
+        let iov = [IoSlice::new(&message)];
+        let flags = MsgFlags::empty();
+
+        // Send the 3 messages (the receiver buffer can only hold 2 messages)
+        // to create an overflow.
+        for _ in 0..3 {
+            let l =
+                sendmsg(out_socket, &iov, &[], flags, Some(&address)).unwrap();
+            assert_eq!(message.len(), l);
+        }
+
+        // Receive the message and check the drop counter if any.
+        loop {
+            let mut buffer = vec![0u8; message.len()];
+            let mut cmsgspace = nix::cmsg_space!(u32);
+
+            let mut iov = [IoSliceMut::new(&mut buffer)];
+
+            match recvmsg::<()>(
+                in_socket,
+                &mut iov,
+                Some(&mut cmsgspace),
+                MsgFlags::MSG_DONTWAIT,
+            ) {
+                Ok(r) => {
+                    drop_counter = match r.cmsgs().next() {
+                        Some(ControlMessageOwned::RxqOvfl(drop_counter)) => {
+                            drop_counter
+                        }
+                        Some(_) => panic!("Unexpected control message"),
+                        None => 0,
+                    };
+                }
+                Err(Error::EAGAIN) => {
+                    break;
+                }
+                _ => {
+                    panic!("unknown recvmsg() error");
+                }
+            }
+        }
+    }
+
+    // One packet lost.
+    assert_eq!(drop_counter, 1);
+
+    // Close sockets
+    nix::unistd::close(in_socket).unwrap();
+    nix::unistd::close(out_socket).unwrap();
+}
+
+#[cfg(any(target_os = "linux", target_os = "android",))]
+mod linux_errqueue {
+    use super::FromStr;
+    use nix::sys::socket::*;
+
+    // Send a UDP datagram to a bogus destination address and observe an ICMP error (v4).
+    //
+    // Disable the test on QEMU because QEMU emulation of IP_RECVERR is broken (as documented on PR
+    // #1514).
+    #[cfg_attr(qemu, ignore)]
+    #[test]
+    fn test_recverr_v4() {
+        #[repr(u8)]
+        enum IcmpTypes {
+            DestUnreach = 3, // ICMP_DEST_UNREACH
+        }
+        #[repr(u8)]
+        enum IcmpUnreachCodes {
+            PortUnreach = 3, // ICMP_PORT_UNREACH
+        }
+
+        test_recverr_impl::<sockaddr_in, _, _>(
+            "127.0.0.1:6800",
+            AddressFamily::Inet,
+            sockopt::Ipv4RecvErr,
+            libc::SO_EE_ORIGIN_ICMP,
+            IcmpTypes::DestUnreach as u8,
+            IcmpUnreachCodes::PortUnreach as u8,
+            // Closure handles protocol-specific testing and returns generic sock_extended_err for
+            // protocol-independent test impl.
+            |cmsg| {
+                if let ControlMessageOwned::Ipv4RecvErr(ext_err, err_addr) =
+                    cmsg
+                {
+                    if let Some(origin) = err_addr {
+                        // Validate that our network error originated from 127.0.0.1:0.
+                        assert_eq!(origin.sin_family, AddressFamily::Inet as _);
+                        assert_eq!(
+                            origin.sin_addr.s_addr,
+                            u32::from_be(0x7f000001)
+                        );
+                        assert_eq!(origin.sin_port, 0);
+                    } else {
+                        panic!("Expected some error origin");
+                    }
+                    *ext_err
+                } else {
+                    panic!("Unexpected control message {:?}", cmsg);
+                }
+            },
+        )
+    }
+
+    // Essentially the same test as v4.
+    //
+    // Disable the test on QEMU because QEMU emulation of IPV6_RECVERR is broken (as documented on
+    // PR #1514).
+    #[cfg_attr(qemu, ignore)]
+    #[test]
+    fn test_recverr_v6() {
+        #[repr(u8)]
+        enum IcmpV6Types {
+            DestUnreach = 1, // ICMPV6_DEST_UNREACH
+        }
+        #[repr(u8)]
+        enum IcmpV6UnreachCodes {
+            PortUnreach = 4, // ICMPV6_PORT_UNREACH
+        }
+
+        test_recverr_impl::<sockaddr_in6, _, _>(
+            "[::1]:6801",
+            AddressFamily::Inet6,
+            sockopt::Ipv6RecvErr,
+            libc::SO_EE_ORIGIN_ICMP6,
+            IcmpV6Types::DestUnreach as u8,
+            IcmpV6UnreachCodes::PortUnreach as u8,
+            // Closure handles protocol-specific testing and returns generic sock_extended_err for
+            // protocol-independent test impl.
+            |cmsg| {
+                if let ControlMessageOwned::Ipv6RecvErr(ext_err, err_addr) =
+                    cmsg
+                {
+                    if let Some(origin) = err_addr {
+                        // Validate that our network error originated from localhost:0.
+                        assert_eq!(
+                            origin.sin6_family,
+                            AddressFamily::Inet6 as _
+                        );
+                        assert_eq!(
+                            origin.sin6_addr.s6_addr,
+                            std::net::Ipv6Addr::LOCALHOST.octets()
+                        );
+                        assert_eq!(origin.sin6_port, 0);
+                    } else {
+                        panic!("Expected some error origin");
+                    }
+                    *ext_err
+                } else {
+                    panic!("Unexpected control message {:?}", cmsg);
+                }
+            },
+        )
+    }
+
+    fn test_recverr_impl<SA, OPT, TESTF>(
+        sa: &str,
+        af: AddressFamily,
+        opt: OPT,
+        ee_origin: u8,
+        ee_type: u8,
+        ee_code: u8,
+        testf: TESTF,
+    ) where
+        OPT: SetSockOpt<Val = bool>,
+        TESTF: FnOnce(&ControlMessageOwned) -> libc::sock_extended_err,
+    {
+        use nix::errno::Errno;
+        use std::io::IoSliceMut;
+
+        const MESSAGE_CONTENTS: &str = "ABCDEF";
+        let std_sa = std::net::SocketAddr::from_str(sa).unwrap();
+        let sock_addr = SockaddrStorage::from(std_sa);
+        let sock = socket(af, SockType::Datagram, SockFlag::SOCK_CLOEXEC, None)
+            .unwrap();
+        setsockopt(sock, opt, &true).unwrap();
+        if let Err(e) = sendto(
+            sock,
+            MESSAGE_CONTENTS.as_bytes(),
+            &sock_addr,
+            MsgFlags::empty(),
+        ) {
+            assert_eq!(e, Errno::EADDRNOTAVAIL);
+            println!("{:?} not available, skipping test.", af);
+            return;
+        }
+
+        let mut buf = [0u8; 8];
+        let mut iovec = [IoSliceMut::new(&mut buf)];
+        let mut cspace = cmsg_space!(libc::sock_extended_err, SA);
+
+        let msg = recvmsg(
+            sock,
+            &mut iovec,
+            Some(&mut cspace),
+            MsgFlags::MSG_ERRQUEUE,
+        )
+        .unwrap();
+        // The sent message / destination associated with the error is returned:
+        assert_eq!(msg.bytes, MESSAGE_CONTENTS.as_bytes().len());
+        // recvmsg(2): "The original destination address of the datagram that caused the error is
+        // supplied via msg_name;" however, this is not literally true.  E.g., an earlier version
+        // of this test used 0.0.0.0 (::0) as the destination address, which was mutated into
+        // 127.0.0.1 (::1).
+        assert_eq!(msg.address, Some(sock_addr));
+
+        // Check for expected control message.
+        let ext_err = match msg.cmsgs().next() {
+            Some(cmsg) => testf(&cmsg),
+            None => panic!("No control message"),
+        };
+
+        assert_eq!(ext_err.ee_errno, libc::ECONNREFUSED as u32);
+        assert_eq!(ext_err.ee_origin, ee_origin);
+        // ip(7): ee_type and ee_code are set from the type and code fields of the ICMP (ICMPv6)
+        // header.
+        assert_eq!(ext_err.ee_type, ee_type);
+        assert_eq!(ext_err.ee_code, ee_code);
+        // ip(7): ee_info contains the discovered MTU for EMSGSIZE errors.
+        assert_eq!(ext_err.ee_info, 0);
+
+        let bytes = msg.bytes;
+        assert_eq!(&buf[..bytes], MESSAGE_CONTENTS.as_bytes());
+    }
+}
+
+// Disable the test on emulated platforms because it fails in Cirrus-CI.  Lack
+// of QEMU support is suspected.
+#[cfg_attr(qemu, ignore)]
+#[cfg(target_os = "linux")]
+#[test]
+pub fn test_txtime() {
+    use nix::sys::socket::{
+        bind, recvmsg, sendmsg, setsockopt, socket, sockopt, ControlMessage,
+        MsgFlags, SockFlag, SockType, SockaddrIn,
+    };
+    use nix::sys::time::TimeValLike;
+    use nix::time::{clock_gettime, ClockId};
+
+    require_kernel_version!(test_txtime, ">= 5.8");
+
+    let sock_addr = SockaddrIn::from_str("127.0.0.1:6802").unwrap();
+
+    let ssock = socket(
+        AddressFamily::Inet,
+        SockType::Datagram,
+        SockFlag::empty(),
+        None,
+    )
+    .expect("send socket failed");
+
+    let txtime_cfg = libc::sock_txtime {
+        clockid: libc::CLOCK_MONOTONIC,
+        flags: 0,
+    };
+    setsockopt(ssock, sockopt::TxTime, &txtime_cfg).unwrap();
+
+    let rsock = socket(
+        AddressFamily::Inet,
+        SockType::Datagram,
+        SockFlag::empty(),
+        None,
+    )
+    .unwrap();
+    bind(rsock, &sock_addr).unwrap();
+
+    let sbuf = [0u8; 2048];
+    let iov1 = [std::io::IoSlice::new(&sbuf)];
+
+    let now = clock_gettime(ClockId::CLOCK_MONOTONIC).unwrap();
+    let delay = std::time::Duration::from_secs(1).into();
+    let txtime = (now + delay).num_nanoseconds() as u64;
+
+    let cmsg = ControlMessage::TxTime(&txtime);
+    sendmsg(ssock, &iov1, &[cmsg], MsgFlags::empty(), Some(&sock_addr))
+        .unwrap();
+
+    let mut rbuf = [0u8; 2048];
+    let mut iov2 = [std::io::IoSliceMut::new(&mut rbuf)];
+    recvmsg::<()>(rsock, &mut iov2, None, MsgFlags::empty()).unwrap();
+}