New nsock regression test: TestConnectFailure.

Trigger a ENETUNREACH error on connect() and check if properly reported.

As of now the test fails, the error isn't delivered.

nsock/tests/connect.c

@@ -80,6 +80,21 @@ static int connect_tcp(void *tdata) {
   return ctd->connect_result;
 }
 
+static int connect_tcp_failure(void *tdata) {
+  struct connect_test_data *ctd = (struct connect_test_data *)tdata;
+  struct sockaddr_in peer;
+
+  memset(&peer, 0, sizeof(peer));
+  peer.sin_family = AF_INET;
+  inet_aton("192.0.2.1", &peer.sin_addr);   /* Unreachable by RFC5737 */
+
+  nsock_connect_tcp(ctd->nsp, ctd->nsi, connect_handler, 4000, NULL,
+                    (struct sockaddr *)&peer, sizeof(peer), PORT_TCP);
+
+  nsock_loop(ctd->nsp, 4000);
+  return ctd->connect_result == -ENETUNREACH ? 0 : ctd->connect_result;
+}
+
 
 const struct test_case TestConnectTCP = {
   .t_name     = "simple tcp connection",
@@ -87,3 +102,10 @@ const struct test_case TestConnectTCP = {
   .t_run      = connect_tcp,
   .t_teardown = connect_teardown
 };
+
+const struct test_case TestConnectFailure = {
+  .t_name     = "tcp connection failure case",
+  .t_setup    = connect_setup,
+  .t_run      = connect_tcp_failure,
+  .t_teardown = connect_teardown
+};

nsock/tests/tests_main.c

@@ -30,6 +30,7 @@ extern const struct test_case TestTimer;
 extern const struct test_case TestLogLevels;
 extern const struct test_case TestErrLevels;
 extern const struct test_case TestConnectTCP;
+extern const struct test_case TestConnectFailure;
 extern const struct test_case TestGHLists;
 extern const struct test_case TestGHHeaps;
 extern const struct test_case TestHeapOrdering;
@@ -48,6 +49,7 @@ static const struct test_case *TestCases[] = {
   &TestErrLevels,
   /* ---- connect.c */
   &TestConnectTCP,
+  &TestConnectFailure,
   /* ---- ghlists.c */
   &TestGHLists,
   /* ---- ghheaps.c */