lldp: add test coverage for sd_lldp_get_neighbors() with multiple neighbors

In particular, check that the order of the results is consistent.

This test coverage will be useful in order to refactor the compare_func
used while sorting the results.

When introduced, this test also uncovered a memory leak in sd_lldp_stop(),
which was then fixed by a separate commit using a specialized function
as destructor of the LLDP Hashmap.

Tested:
  $ ninja -C build/ test
  $ valgrind --leak-check=full build/test-lldp

1 files changed, 130 insertions, 0 deletions

diff --git a/src/libsystemd-network/test-lldp.c b/src/libsystemd-network/test-lldp.c
index e0d4d9a85..cb4545d90 100644
--- a/src/libsystemd-network/test-lldp.c
+++ b/src/libsystemd-network/test-lldp.c
@@ -229,6 +229,135 @@ static void test_receive_oui_packet(sd_event *e) {
         assert_se(stop_lldp(lldp) == 0);
 }
 
+static void test_multiple_neighbors_sorted(sd_event *e) {
+
+        static const uint8_t frame1[] = {
+                /* Ethernet header */
+                0x01, 0x80, 0xc2, 0x00, 0x00, 0x03,     /* Destination MAC */
+                0x01, 0x02, 0x03, 0x04, 0x05, 0x06,     /* Source MAC */
+                0x88, 0xcc,                             /* Ethertype */
+                /* LLDP mandatory TLVs */
+                0x02, 0x04, 0x01, '1', '/', '2',        /* Chassis component: "1/2" */
+                0x04, 0x04, 0x02, '2', '/', '3',        /* Port component: "2/3" */
+                0x06, 0x02, 0x00, 0x78,                 /* TTL: 120 seconds */
+                0x00, 0x00                              /* End Of LLDPDU */
+        };
+        static const uint8_t frame2[] = {
+                /* Ethernet header */
+                0x01, 0x80, 0xc2, 0x00, 0x00, 0x03,     /* Destination MAC */
+                0x01, 0x02, 0x03, 0x04, 0x05, 0x06,     /* Source MAC */
+                0x88, 0xcc,                             /* Ethertype */
+                /* LLDP mandatory TLVs */
+                0x02, 0x04, 0x01, '2', '/', '1',        /* Chassis component: "2/1" */
+                0x04, 0x04, 0x02, '1', '/', '3',        /* Port component: "1/3" */
+                0x06, 0x02, 0x00, 0x78,                 /* TTL: 120 seconds */
+                0x00, 0x00                              /* End Of LLDPDU */
+        };
+        static const uint8_t frame3[] = {
+                /* Ethernet header */
+                0x01, 0x80, 0xc2, 0x00, 0x00, 0x03,     /* Destination MAC */
+                0x01, 0x02, 0x03, 0x04, 0x05, 0x06,     /* Source MAC */
+                0x88, 0xcc,                             /* Ethertype */
+                /* LLDP mandatory TLVs */
+                0x02, 0x05, 0x01, '2', '/', '1', '0',   /* Chassis component: "2/10" */
+                0x04, 0x04, 0x02, '1', '/', '0',        /* Port component: "1/0" */
+                0x06, 0x02, 0x00, 0x78,                 /* TTL: 120 seconds */
+                0x00, 0x00                              /* End Of LLDPDU */
+        };
+        static const uint8_t frame4[] = {
+                /* Ethernet header */
+                0x01, 0x80, 0xc2, 0x00, 0x00, 0x03,     /* Destination MAC */
+                0x01, 0x02, 0x03, 0x04, 0x05, 0x06,     /* Source MAC */
+                0x88, 0xcc,                             /* Ethertype */
+                /* LLDP mandatory TLVs */
+                0x02, 0x05, 0x01, '2', '/', '1', '9',   /* Chassis component: "2/19" */
+                0x04, 0x04, 0x02, '1', '/', '0',        /* Port component: "1/0" */
+                0x06, 0x02, 0x00, 0x78,                 /* TTL: 120 seconds */
+                0x00, 0x00                              /* End Of LLDPDU */
+        };
+        static const uint8_t frame5[] = {
+                /* Ethernet header */
+                0x01, 0x80, 0xc2, 0x00, 0x00, 0x03,     /* Destination MAC */
+                0x01, 0x02, 0x03, 0x04, 0x05, 0x06,     /* Source MAC */
+                0x88, 0xcc,                             /* Ethertype */
+                /* LLDP mandatory TLVs */
+                0x02, 0x04, 0x01, '1', '/', '2',        /* Chassis component: "1/2" */
+                0x04, 0x05, 0x02, '2', '/', '1', '0',   /* Port component: "2/10" */
+                0x06, 0x02, 0x00, 0x78,                 /* TTL: 120 seconds */
+                0x00, 0x00                              /* End Of LLDPDU */
+        };
+        static const uint8_t frame6[] = {
+                /* Ethernet header */
+                0x01, 0x80, 0xc2, 0x00, 0x00, 0x03,     /* Destination MAC */
+                0x01, 0x02, 0x03, 0x04, 0x05, 0x06,     /* Source MAC */
+                0x88, 0xcc,                             /* Ethertype */
+                /* LLDP mandatory TLVs */
+                0x02, 0x04, 0x01, '1', '/', '2',        /* Chassis component: "1/2" */
+                0x04, 0x05, 0x02, '2', '/', '3', '9',   /* Port component: "2/10" */
+                0x06, 0x02, 0x00, 0x78,                 /* TTL: 120 seconds */
+                0x00, 0x00                              /* End Of LLDPDU */
+        };
+        static const char* expected[] = {
+                /* ordered pairs of Chassis+Port */
+                "1/2", "2/10",
+                "1/2", "2/3",
+                "1/2", "2/39",
+                "2/1", "1/3",
+                "2/10", "1/0",
+                "2/19", "1/0",
+        };
+
+        sd_lldp *lldp;
+        sd_lldp_neighbor **neighbors;
+        int i;
+        uint8_t type;
+        const void *data;
+        size_t length, expected_length;
+        uint16_t ttl;
+
+        lldp_handler_calls = 0;
+        assert_se(start_lldp(&lldp, e, lldp_handler, NULL) == 0);
+
+        assert_se(write(test_fd[1], frame1, sizeof(frame1)) == sizeof(frame1));
+        sd_event_run(e, 0);
+        assert_se(write(test_fd[1], frame2, sizeof(frame2)) == sizeof(frame2));
+        sd_event_run(e, 0);
+        assert_se(write(test_fd[1], frame3, sizeof(frame3)) == sizeof(frame3));
+        sd_event_run(e, 0);
+        assert_se(write(test_fd[1], frame4, sizeof(frame4)) == sizeof(frame4));
+        sd_event_run(e, 0);
+        assert_se(write(test_fd[1], frame5, sizeof(frame5)) == sizeof(frame5));
+        sd_event_run(e, 0);
+        assert_se(write(test_fd[1], frame6, sizeof(frame6)) == sizeof(frame6));
+        sd_event_run(e, 0);
+        assert_se(lldp_handler_calls == 6);
+
+        assert_se(sd_lldp_get_neighbors(lldp, &neighbors) == 6);
+
+        for (i = 0; i < 6; i++) {
+                assert_se(sd_lldp_neighbor_get_chassis_id(neighbors[i], &type, &data, &length) == 0);
+                assert_se(type == SD_LLDP_CHASSIS_SUBTYPE_CHASSIS_COMPONENT);
+                expected_length = strlen(expected[2 * i]);
+                assert_se(length == expected_length);
+                assert_se(memcmp(data, expected[2 * i], expected_length) == 0);
+
+                assert_se(sd_lldp_neighbor_get_port_id(neighbors[i], &type, &data, &length) == 0);
+                assert_se(type == SD_LLDP_PORT_SUBTYPE_PORT_COMPONENT);
+                expected_length = strlen(expected[2 * i + 1]);
+                assert_se(length == expected_length);
+                assert_se(memcmp(data, expected[2 * i + 1], expected_length) == 0);
+
+                assert_se(sd_lldp_neighbor_get_ttl(neighbors[i], &ttl) == 0);
+                assert_se(ttl == 120);
+        }
+
+        for (i = 0; i < 6; i++)
+                sd_lldp_neighbor_unref(neighbors[i]);
+        free(neighbors);
+
+        assert_se(stop_lldp(lldp) == 0);
+}
+
 int main(int argc, char *argv[]) {
         _cleanup_(sd_event_unrefp) sd_event *e = NULL;
 
@@ -239,6 +368,7 @@ int main(int argc, char *argv[]) {
         test_receive_basic_packet(e);
         test_receive_incomplete_packet(e);
         test_receive_oui_packet(e);
+        test_multiple_neighbors_sorted(e);
 
         return 0;
 }