Improve tests

Author: Gleb Pomykalov

test/sys/test_socket.rs

@@ -169,10 +169,10 @@ mod recvfrom {
 
     const MSG: &'static [u8] = b"Hello, World!";
 
-    fn sendrecv<Fs, Fr>(rsock: RawFd, ssock: RawFd, f_send: Fs, f_recv: Fr) -> Option<SockAddr>
+    fn sendrecv<Fs, Fr>(rsock: RawFd, ssock: RawFd, f_send: Fs, mut f_recv: Fr) -> Option<SockAddr>
         where
             Fs: Fn(RawFd, &[u8], MsgFlags) -> Result<usize> + Send + 'static,
-            Fr: Fn(usize, Option<SockAddr>),
+            Fr: FnMut(usize, Option<SockAddr>),
     {
         let mut buf: [u8; 13] = [0u8; 13];
         let mut l = 0;
@@ -240,6 +240,11 @@ mod recvfrom {
         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 std_sa = SocketAddr::from_str("127.0.0.1:6791").unwrap();
             let inet_addr = InetAddr::from_std(&std_sa);
             let sock_addr = SockAddr::new_inet(inet_addr);
@@ -249,9 +254,8 @@ mod recvfrom {
                                None
             ).unwrap();
 
-            let segment_size = 2;
-
-            setsockopt(rsock, UdpGsoSegment, &segment_size).expect("setsockopt UDP_SEGMENT failed");
+            setsockopt(rsock, UdpGsoSegment, &(segment_size as _))
+                .expect("setsockopt UDP_SEGMENT failed");
 
             bind(rsock, &sock_addr).unwrap();
             let ssock = socket(
@@ -261,48 +265,45 @@ mod recvfrom {
                 None,
             ).expect("send socket failed");
 
-            let from = sendrecv(rsock, ssock, move |s, m, flags| {
+            let mut num_packets_received: i32 = 0;
+
+            sendrecv(rsock, ssock, move |s, m, flags| {
                 let iov = [IoVec::from_slice(m)];
-                let cmsg = ControlMessage::UdpGsoSegments(&2);
+                let cmsg = ControlMessage::UdpGsoSegments(&segment_size);
                 sendmsg(s, &iov, &[cmsg], flags, Some(&sock_addr))
-            }, |len, _| {
-                assert!(len <= segment_size as usize);
+            }, {
+                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;
+                }
             });
-            // UDP sockets should set the from address
-            assert_eq!(AddressFamily::Inet, from.unwrap().family());
+
+            // 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]
         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 std_sa = SocketAddr::from_str("127.0.0.1:6792").unwrap();
             let inet_addr = InetAddr::from_std(&std_sa);
-            let sock_addr = SockAddr::new_inet(inet_addr);
             let rsock = socket(AddressFamily::Inet,
                                SockType::Datagram,
                                SockFlag::empty(),
                                None
-            ).unwrap();
-
-            setsockopt(rsock, UdpGroSegment, &true).expect("setsockopt UDP_GRO failed");
-
-            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 iov = [IoVec::from_slice(m)];
-                let cmsg = ControlMessage::UdpGsoSegments(&2);
-                sendmsg(s, &iov, &[cmsg], flags, Some(&sock_addr))
-            }, |_, _| {});
+            ).unwrap();I
 
-            // UDP sockets should set the from address
-            assert_eq!(AddressFamily::Inet, from.unwrap().family());
+            setsockopt(rsock, UdpGroSegment, &true)
+                .expect("setsockopt UDP_GRO failed");
         }
     }
 }