Match BSD-family IPv4 multicast TTL/loopback ABI to system headers

src/socket.rs

@@ -16,6 +16,16 @@ use std::net::Ipv6Addr;
 use std::net::{self, Ipv4Addr, Shutdown};
 #[cfg(any(unix, all(target_os = "wasi", not(target_env = "p1"))))]
 use std::os::fd::{FromRawFd, IntoRawFd};
+#[cfg(any(
+    target_os = "dragonfly",
+    target_os = "freebsd",
+    target_os = "openbsd",
+    target_os = "netbsd",
+    target_os = "solaris",
+    target_os = "illumos",
+    target_os = "nto",
+))]
+use std::os::raw::c_uchar;
 #[cfg(windows)]
 use std::os::windows::io::{FromRawSocket, IntoRawSocket};
 use std::time::Duration;
@@ -27,6 +37,30 @@ use crate::{Domain, Protocol, SockAddr, TcpKeepalive, Type};
 #[cfg(not(any(target_os = "redox", target_os = "wasi")))]
 use crate::{MaybeUninitSlice, MsgHdr, RecvFlags};
 
+// Match the system headers for these IPv4 multicast socket options. These
+// targets declare `unsigned char` rather than `int`.
+#[cfg(any(
+    target_os = "dragonfly",
+    target_os = "freebsd",
+    target_os = "openbsd",
+    target_os = "netbsd",
+    target_os = "solaris",
+    target_os = "illumos",
+    target_os = "nto",
+))]
+type IpV4MultiCastType = c_uchar;
+
+#[cfg(not(any(
+    target_os = "dragonfly",
+    target_os = "freebsd",
+    target_os = "openbsd",
+    target_os = "netbsd",
+    target_os = "solaris",
+    target_os = "illumos",
+    target_os = "nto",
+)))]
+type IpV4MultiCastType = c_int;
+
 /// Owned wrapper around a system socket.
 ///
 /// This type simply wraps an instance of a file descriptor (`c_int`) on Unix
@@ -1546,7 +1580,7 @@ impl Socket {
     /// [`set_multicast_loop_v4`]: Socket::set_multicast_loop_v4
     pub fn multicast_loop_v4(&self) -> io::Result<bool> {
         unsafe {
-            getsockopt::<c_int>(self.as_raw(), sys::IPPROTO_IP, sys::IP_MULTICAST_LOOP)
+            getsockopt::<IpV4MultiCastType>(self.as_raw(), sys::IPPROTO_IP, sys::IP_MULTICAST_LOOP)
                 .map(|loop_v4| loop_v4 != 0)
         }
     }
@@ -1561,7 +1595,7 @@ impl Socket {
                 self.as_raw(),
                 sys::IPPROTO_IP,
                 sys::IP_MULTICAST_LOOP,
-                loop_v4 as c_int,
+                loop_v4 as IpV4MultiCastType,
             )
         }
     }
@@ -1573,7 +1607,7 @@ impl Socket {
     /// [`set_multicast_ttl_v4`]: Socket::set_multicast_ttl_v4
     pub fn multicast_ttl_v4(&self) -> io::Result<u32> {
         unsafe {
-            getsockopt::<c_int>(self.as_raw(), sys::IPPROTO_IP, sys::IP_MULTICAST_TTL)
+            getsockopt::<IpV4MultiCastType>(self.as_raw(), sys::IPPROTO_IP, sys::IP_MULTICAST_TTL)
                 .map(|ttl| ttl as u32)
         }
     }
@@ -1591,7 +1625,7 @@ impl Socket {
                 self.as_raw(),
                 sys::IPPROTO_IP,
                 sys::IP_MULTICAST_TTL,
-                ttl as c_int,
+                ttl as IpV4MultiCastType,
             )
         }
     }

tests/socket.rs

@@ -21,7 +21,7 @@ use std::io::Write;
 #[cfg(not(target_os = "vita"))]
 use std::mem::MaybeUninit;
 use std::mem::{self};
-use std::net::{Ipv4Addr, SocketAddr, SocketAddrV4, TcpStream};
+use std::net::{Ipv4Addr, SocketAddr, SocketAddrV4, TcpStream, UdpSocket};
 #[cfg(not(any(target_os = "redox", target_os = "vita")))]
 use std::net::{Ipv6Addr, SocketAddrV6};
 #[cfg(all(
@@ -1970,3 +1970,52 @@ fn set_busy_poll() {
         assert!(socket.busy_poll().unwrap() == i);
     }
 }
+
+/// A helper type to allow testing socket options on both `Socket` and `UdpSocket`.
+pub enum SocketRef<'a> {
+    Socket(&'a Socket),
+    UdpSocket(&'a UdpSocket),
+}
+
+impl<'a> From<&'a Socket> for SocketRef<'a> {
+    fn from(socket: &'a Socket) -> Self {
+        SocketRef::Socket(socket)
+    }
+}
+
+impl<'a> From<&'a UdpSocket> for SocketRef<'a> {
+    fn from(socket: &'a UdpSocket) -> Self {
+        SocketRef::UdpSocket(socket)
+    }
+}
+
+/// Assert that `multicast_ttl_v4` is set to a given value on `socket`.
+#[track_caller]
+pub fn assert_multicast_ttl_v4<'a>(socket: impl Into<SocketRef<'a>>, want: u32) {
+    let socket = socket.into();
+    let ttl = match socket {
+        SocketRef::Socket(socket) => socket.multicast_ttl_v4().unwrap(),
+        SocketRef::UdpSocket(socket) => socket.multicast_ttl_v4().unwrap(),
+    };
+    assert_eq!(ttl, want, "multicast_ttl_v4 option");
+}
+
+#[cfg(any(
+    target_os = "dragonfly",
+    target_os = "freebsd",
+    target_os = "openbsd",
+    target_os = "netbsd",
+    target_os = "solaris",
+    target_os = "illumos",
+    target_os = "nto",
+))]
+#[test]
+fn multicast_v4_bsd_abi() {
+    let socket = UdpSocket::bind((Ipv4Addr::LOCALHOST, 0)).unwrap();
+    socket.set_multicast_ttl_v4(258).unwrap();
+    assert_multicast_ttl_v4(&socket, 2);
+
+    let socket = Socket::new(Domain::IPV4, Type::DGRAM, Some(Protocol::UDP)).unwrap();
+    socket.set_multicast_ttl_v4(258).unwrap();
+    assert_multicast_ttl_v4(&socket, 2);
+}