verify the accepted peer in the win32 socketpair emulation

1 files changed, 30 insertions, 1 deletions

diff --git a/tests/compat/pipe2.c b/tests/compat/pipe2.c
index 9d93a55..c0189db 100644
--- a/tests/compat/pipe2.c
+++ b/tests/compat/pipe2.c
@@ -74,8 +74,15 @@ int socketpair(int domain, int type, int protocol, int socket_vector[2])
                 .sin_port = 0,
         };
 
+        struct sockaddr_in self, peer;
         int yes = 1, e;
-        if (setsockopt(listener, SOL_SOCKET, SO_REUSEADDR,
+
+        /*
+         * SO_REUSEADDR does not mean here what it means on unix: it lets any
+         * other process bind the same address and port and take over the
+         * rendezvous. SO_EXCLUSIVEADDRUSE is the flag that keeps the port ours.
+         */
+        if (setsockopt(listener, SOL_SOCKET, SO_EXCLUSIVEADDRUSE,
                         (void *)&yes, sizeof yes) == -1)
                 goto err;
 
@@ -104,6 +111,28 @@ int socketpair(int domain, int type, int protocol, int socket_vector[2])
         if (socket_vector[1] == -1)
                 goto err;
 
+        /*
+         * The listening port is enumerable by anything running as the user, so
+         * the connection we just accepted is not necessarily the one we made.
+         * Pair the two halves only if they are each other's peer.
+         */
+        memset(&self, 0, sizeof self);
+        addrlen = sizeof self;
+        if (getsockname(socket_vector[0], (struct sockaddr *)&self, &addrlen) != 0)
+                goto err;
+
+        memset(&peer, 0, sizeof peer);
+        addrlen = sizeof peer;
+        if (getpeername(socket_vector[1], (struct sockaddr *)&peer, &addrlen) != 0)
+                goto err;
+
+        if (self.sin_family != peer.sin_family ||
+            self.sin_addr.s_addr != peer.sin_addr.s_addr ||
+            self.sin_port != peer.sin_port) {
+                WSASetLastError(WSAECONNREFUSED);
+                goto err;
+        }
+
         closesocket(listener);
 
         create_issue_1069_sentinels(socket_vector);