Problem: TIPC availability check is too strict (#2977)

* Problem: TIPC availability check is too strict

Solution: at build time only check if the API is available. In the tests
do a first check and a skip if the functionality is not available.

TIPC needs an in-tree but not loaded by default kernel module, tipc.ko
to be loaded, which requires root, so it is unlikely to be available on
any build system by default.
This will allow most distributions to ship with TIPC support built in,
and to avoid tests failure if the module is not there.

* Problem: no Travis tests for TIPC

Solution: mark one job with sudo: required and load the kernel module

* Problem: CMake fails when test returns 77 (skip)

Solution: set property to let it mark the test as skipped as intended

.travis.yml

@@ -57,8 +57,9 @@ matrix:
         - libsodium-dev
         - asciidoc
         - xmlto
-  - env: BUILD_TYPE=default CURVE=libsodium DRAFT=enabled GSSAPI=enabled PGM=enabled NORM=enabled
+  - env: BUILD_TYPE=default CURVE=libsodium DRAFT=enabled GSSAPI=enabled PGM=enabled NORM=enabled TIPC=enabled
     os: linux
+    sudo: required
     addons:
       apt:
         sources:

builds/cmake/Modules/ZMQSourceRunChecks.cmake

@@ -195,19 +195,12 @@ int main(int argc, char *argv [])
 {
     struct sockaddr_tipc topsrv;
     int sd = socket(AF_TIPC, SOCK_SEQPACKET, 0);
-    if (sd == -EAFNOSUPPORT) {
-        return 1;
-    }
     memset(&topsrv, 0, sizeof(topsrv));
     topsrv.family = AF_TIPC;
     topsrv.addrtype = TIPC_ADDR_NAME;
     topsrv.addr.name.name.type = TIPC_TOP_SRV;
     topsrv.addr.name.name.instance = TIPC_TOP_SRV;
     fcntl(sd, F_SETFL, O_NONBLOCK);
-    if (connect(sd, (struct sockaddr *)&topsrv, sizeof(topsrv)) != 0) {
-        if (errno != EINPROGRESS)
-            return -1;
-    }
 }
 "
     ZMQ_HAVE_TIPC)

ci_build.sh

@@ -48,6 +48,10 @@ if [ $BUILD_TYPE == "default" ]; then
         CONFIG_OPTS+=("--with-norm=yes")
     fi
 
+    if [ -n "$TIPC" ] && [ "$TIPC" == "enabled" ]; then
+        sudo modprobe tipc
+    fi
+
     if [ -n "$POLLER" ]; then
         CONFIG_OPTS+=("--with-poller=${POLLER}")
     fi

configure.ac

@@ -93,19 +93,12 @@ AC_RUN_IFELSE(
         ]],[[
             struct sockaddr_tipc topsrv;
             int sd = socket(AF_TIPC, SOCK_SEQPACKET, 0);
-            if (sd == -EAFNOSUPPORT) {
-                return 1;
-            }
             memset(&topsrv, 0, sizeof(topsrv));
             topsrv.family = AF_TIPC;
             topsrv.addrtype = TIPC_ADDR_NAME;
             topsrv.addr.name.name.type = TIPC_TOP_SRV;
             topsrv.addr.name.name.instance = TIPC_TOP_SRV;
             fcntl(sd, F_SETFL, O_NONBLOCK);
-            if (connect(sd, (struct sockaddr *)&topsrv, sizeof(topsrv)) != 0) {
-                if (errno != EINPROGRESS)
-                    return -1;
-            }
         ]])
     ],
     [libzmq_tipc_support=yes],

tests/CMakeLists.txt

@@ -203,6 +203,7 @@ foreach(test ${tests})
     add_test(NAME ${test} COMMAND ${test})
   endif()
   set_tests_properties(${test} PROPERTIES TIMEOUT 10)
+  set_tests_properties(${test} PROPERTIES SKIP_RETURN_CODE 77)
 endforeach()
 
 #override timeout for these tests

tests/test_address_tipc.cpp

@@ -131,6 +131,11 @@ int main ()
 {
     setup_test_environment ();
 
+    if (!is_tipc_available ()) {
+        printf ("TIPC environment unavailable, skipping test\n");
+        return 77;
+    }
+
     UNITY_BEGIN ();
     RUN_TEST (test_tipc_port_name_and_domain);
     RUN_TEST (test_tipc_port_identity);

tests/test_connect_delay_tipc.cpp

@@ -31,6 +31,11 @@
 
 int main (void)
 {
+    if (!is_tipc_available ()) {
+        printf ("TIPC environment unavailable, skipping test\n");
+        return 77;
+    }
+
     int val;
     int rc;
     char buffer[16];

tests/test_pair_tipc.cpp

@@ -32,6 +32,11 @@
 
 int main (void)
 {
+    if (!is_tipc_available ()) {
+        printf ("TIPC environment unavailable, skipping test\n");
+        return 77;
+    }
+
     fprintf (stderr, "test_pair_tipc running...\n");
 
     void *ctx = zmq_init (1);

tests/test_reqrep_device_tipc.cpp

@@ -31,6 +31,11 @@
 
 int main (void)
 {
+    if (!is_tipc_available ()) {
+        printf ("TIPC environment unavailable, skipping test\n");
+        return 77;
+    }
+
     fprintf (stderr, "test_reqrep_device_tipc running...\n");
 
     void *ctx = zmq_init (1);

tests/test_reqrep_tipc.cpp

@@ -31,6 +31,11 @@
 
 int main (void)
 {
+    if (!is_tipc_available ()) {
+        printf ("TIPC environment unavailable, skipping test\n");
+        return 77;
+    }
+
     fprintf (stderr, "test_reqrep_tipc running...\n");
 
     void *ctx = zmq_init (1);

tests/test_router_mandatory_tipc.cpp

@@ -32,6 +32,11 @@
 
 int main (void)
 {
+    if (!is_tipc_available ()) {
+        printf ("TIPC environment unavailable, skipping test\n");
+        return 77;
+    }
+
     fprintf (stderr, "test_router_mandatory_tipc running...\n");
 
     void *ctx = zmq_init (1);

tests/test_shutdown_stress_tipc.cpp

@@ -49,6 +49,11 @@ static void *worker (void *s)
 
 int main (void)
 {
+    if (!is_tipc_available ()) {
+        printf ("TIPC environment unavailable, skipping test\n");
+        return 77;
+    }
+
     void *ctx;
     void *s1;
     void *s2;

tests/test_sub_forward_tipc.cpp

@@ -31,6 +31,11 @@
 
 int main (void)
 {
+    if (!is_tipc_available ()) {
+        printf ("TIPC environment unavailable, skipping test\n");
+        return 77;
+    }
+
     fprintf (stderr, "test_sub_forward running...\n");
 
     void *ctx = zmq_init (1);

tests/test_term_endpoint_tipc.cpp

@@ -31,6 +31,11 @@
 
 int main (void)
 {
+    if (!is_tipc_available ()) {
+        printf ("TIPC environment unavailable, skipping test\n");
+        return 77;
+    }
+
     int rc;
     char buf[32];
     const char *ep = "tipc://{5560,0,0}";

tests/testutil.hpp

@@ -389,6 +389,29 @@ int is_ipv6_available (void)
 #endif // _WIN32_WINNT < 0x0600
 }
 
+// check if tipc is available (0/false if not, 1/true if it is)
+// only way to reliably check is to actually open a socket and try to bind it
+// as it depends on a non-default kernel module to be already loaded
+int is_tipc_available (void)
+{
+#ifndef ZMQ_HAVE_TIPC
+    return 0;
+#else
+    int tipc = 0;
+
+    void *ctx = zmq_init (1);
+    assert (ctx);
+    void *rep = zmq_socket (ctx, ZMQ_REP);
+    assert (rep);
+    tipc = zmq_bind (rep, "tipc://{5560,0,0}");
+
+    zmq_close (rep);
+    zmq_ctx_term (ctx);
+
+    return tipc == 0;
+#endif // ZMQ_HAVE_TIPC
+}
+
 #if defined(ZMQ_HAVE_WINDOWS)
 
 int close (int fd)