Expand ECN support

.travis.yml

@@ -37,7 +37,7 @@ before_script:
 script:
 - cargo clean
 - cargo build --all-features
-- cargo test --all-features
+- RUST_BACKTRACE=1 cargo test --all-features
 - if [[ "$TRAVIS_RUST_VERSION" == stable ]]; then
     cargo fmt -- --check;
   fi

quinn/Cargo.toml

@@ -35,7 +35,7 @@ untrusted = "0.6.2"
 webpki = "0.19"
 webpki-roots = "0.16"
 ct-logs = "0.5"
-libc = "0.2.46"
+libc = "0.2.49"
 mio = "0.6"
 
 [dev-dependencies]

quinn/src/platform/cmsg.rs

@@ -36,7 +36,7 @@ impl<'a> Encoder<'a> {
         assert!(mem::align_of::<T>() <= mem::align_of::<libc::cmsghdr>());
         let space = unsafe { libc::CMSG_SPACE(mem::size_of_val(&value) as _) as usize };
         assert!(
-            self.hdr.msg_controllen >= self.len + space,
+            self.hdr.msg_controllen as usize >= self.len + space,
             "control message buffer too small"
         );
         let cmsg = self.cmsg.take().expect("no control buffer space remaining");
@@ -60,7 +60,7 @@ impl<'a> Encoder<'a> {
 // by `sendmsg`.
 impl<'a> Drop for Encoder<'a> {
     fn drop(&mut self) {
-        self.hdr.msg_controllen = self.len;
+        self.hdr.msg_controllen = self.len as _;
     }
 }
 

quinn/src/platform/mod.rs

@@ -2,15 +2,13 @@
 use quinn_proto::EcnCodepoint;
 use std::{io, net::SocketAddr};
 
-// The Linux code should work for most unixes, but as of this writing nobody's ported the
-// CMSG_... macros to the libc crate for any of the BSDs.
-#[cfg(target_os = "linux")]
+#[cfg(unix)]
 mod cmsg;
-#[cfg(target_os = "linux")]
-mod linux;
+#[cfg(unix)]
+mod unix;
 
 // No ECN support
-#[cfg(not(target_os = "linux"))]
+#[cfg(not(unix))]
 mod fallback;
 
 pub trait UdpExt {

quinn/src/platform/linux.rs → quinn/src/platform/unix.rs

@@ -11,6 +11,11 @@ use quinn_proto::EcnCodepoint;
 
 use super::cmsg;
 
+#[cfg(target_os = "freebsd")]
+type IpTosTy = libc::c_uchar;
+#[cfg(not(target_os = "freebsd"))]
+type IpTosTy = libc::c_int;
+
 impl super::UdpExt for UdpSocket {
     fn init_ext(&self) -> io::Result<()> {
         // Safety
@@ -22,24 +27,26 @@ impl super::UdpExt for UdpSocket {
             mem::size_of::<SocketAddrV6>(),
             mem::size_of::<libc::sockaddr_in6>()
         );
-        assert_eq!(CMSG_LEN, unsafe {
-            libc::CMSG_SPACE(mem::size_of::<libc::c_int>() as _) as usize
-        });
+        assert!(
+            CMSG_LEN >= unsafe { libc::CMSG_SPACE(mem::size_of::<libc::c_int>() as _) as usize }
+        );
         assert!(
             mem::align_of::<libc::cmsghdr>() <= mem::align_of::<cmsg::Aligned<[u8; 0]>>(),
             "control message buffers will be misaligned"
         );
 
         let addr = self.local_addr()?;
 
-        if addr.is_ipv4() || !self.only_v6()? {
+        // macos doesn't support IP_RECVTOS on dual-stack sockets :(
+        if addr.is_ipv4() || (!cfg!(target_os = "macos") && !self.only_v6()?) {
+            let on: libc::c_int = 1;
             let rc = unsafe {
                 libc::setsockopt(
                     self.as_raw_fd(),
                     libc::IPPROTO_IP,
                     libc::IP_RECVTOS,
-                    &true as *const _ as _,
-                    1,
+                    &on as *const _ as _,
+                    mem::size_of_val(&on) as _,
                 )
             };
             if rc == -1 {
@@ -54,7 +61,7 @@ impl super::UdpExt for UdpSocket {
                     libc::IPPROTO_IPV6,
                     libc::IPV6_RECVTCLASS,
                     &on as *const _ as _,
-                    mem::size_of::<libc::c_int>() as _,
+                    mem::size_of_val(&on) as _,
                 )
             };
             if rc == -1 {
@@ -100,7 +107,7 @@ impl super::UdpExt for UdpSocket {
         };
         let mut encoder = unsafe { cmsg::Encoder::new(&mut hdr, &mut ctrl.0) };
         if is_ipv4 {
-            encoder.push(libc::IPPROTO_IP, libc::IP_TOS, ecn);
+            encoder.push(libc::IPPROTO_IP, libc::IP_TOS, ecn as IpTosTy);
         } else {
             encoder.push(libc::IPPROTO_IPV6, libc::IPV6_TCLASS, ecn);
         }
@@ -148,7 +155,10 @@ impl super::UdpExt for UdpSocket {
         };
         let ecn_bits = if let Some(cmsg) = unsafe { cmsg::Iter::new(&hdr).next() } {
             match (cmsg.cmsg_level, cmsg.cmsg_type) {
-                (libc::IPPROTO_IP, libc::IP_TOS) => unsafe { cmsg::decode::<u8>(cmsg) },
+                // FreeBSD uses IP_RECVTOS here, and we can be liberal because cmsgs are opt-in.
+                (libc::IPPROTO_IP, libc::IP_TOS) | (libc::IPPROTO_IP, libc::IP_RECVTOS) => unsafe {
+                    cmsg::decode::<u8>(cmsg)
+                },
                 (libc::IPPROTO_IPV6, libc::IPV6_TCLASS) => unsafe {
                     cmsg::decode::<libc::c_int>(cmsg) as u8
                 },

quinn/src/tests.rs

@@ -25,7 +25,7 @@ fn echo_v4() {
 }
 
 #[test]
-#[cfg(target_os = "linux")] // Dual-stack sockets aren't the default anywhere else.
+#[cfg(any(target_os = "linux", target_os = "macos"))] // Dual-stack sockets aren't the default anywhere else.
 fn echo_dualstack() {
     run_echo(
         SocketAddr::new(IpAddr::V6(Ipv6Addr::UNSPECIFIED), 0),