api: raise an error if the socket path is too long

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

Author: giuseppe

api.c

@@ -21,6 +21,11 @@ int api_bindlisten(const char *api_socket)
     }
     memset(&addr, 0, sizeof(addr));
     addr.sun_family = AF_UNIX;
+    if (strlen(api_socket) >= sizeof(addr.sun_path)) {
+        fprintf(stderr, "the specified API socket path is too long (>= %lu)\n",
+                sizeof(addr.sun_path));
+        return -1;
+    }
     strncpy(addr.sun_path, api_socket, sizeof(addr.sun_path) - 1);
     if (bind(fd, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
         perror("api_bindlisten: bind");

tests/test-slirp4netns-api-socket.sh

@@ -10,6 +10,15 @@ wait_for_network_namespace $child
 
 tmpdir=$(mktemp -d /tmp/slirp4netns-bench.XXXXXXXXXX)
 apisocket=${tmpdir}/slirp4netns.sock
+apisocketlongpath=${tmpdir}/slirp4netns-TOO-LONG-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA.sock
+
+if slirp4netns -c $child --api-socket $apisocketlongpath tun11; then
+    echo "expected failure with apisocket path too long" >&2
+    kill -9 $child
+    rm -rf $tmpdir
+    exit 1
+fi
+
 slirp4netns -c $child --api-socket $apisocket tun11 &
 slirp_pid=$!