northd: Prevent assert with wrong LSP configuration.

We would crash northd with assert when LSP was configured to use
LRP that already had a peer defined. Prevent the crash and add
warning that the configuration is not valid.

Reported-by: Enrique Llorente <ellorent@redhat.com>
Acked-by: Felix Huettner <felix.huettner@stackit.cloud>
Signed-off-by: Ales Musil <amusil@redhat.com>
Signed-off-by: Dumitru Ceara <dceara@redhat.com>
(cherry picked from commit 83b4802)

northd/northd.c

@@ -2452,6 +2452,15 @@ join_logical_ports(const struct sbrec_port_binding_table *sbrec_pb_table,
                 continue;
             }
 
+            if (peer->nbrp->peer) {
+                static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
+                VLOG_WARN_RL(&rl, "Bad configuration: The peer of the switch "
+                             "port '%s' (LRP peer: '%s') has its own peer "
+                             "configuration: '%s'", op->key, peer->key,
+                             peer->nbrp->peer);
+                continue;
+            }
+
             ovn_datapath_add_router_port(op->od, op);
             ovn_datapath_add_ls_peer(peer->od, op->od);
             peer->peer = op;

tests/ovn-northd.at

@@ -16710,3 +16710,22 @@ check_row_count Port_Binding 1 logical_port=lrp2 options:peer{not-in}lrp0
 
 AT_CLEANUP
 ])
+
+OVN_FOR_EACH_NORTHD_NO_HV([
+AT_SETUP([LSP using LRP with peer])
+ovn_start
+
+check ovn-nbctl --wait=sb sync \
+    -- lr-add lr \
+    -- ls-add ls \
+    -- lrp-add lr lrp0 00:00:00:01:ff:01 192.168.1.1/24 peer=lrp1 \
+    -- lrp-add lr lrp1 00:00:00:01:ff:01 192.168.1.1/24 peer=lrp0 \
+    -- lsp-add ls ls-lrp1 \
+    -- lsp-set-type ls-lrp1 router \
+    -- lsp-set-options ls-lrp1 router-port=lrp1 \
+    -- lsp-set-addresses ls-lrp1 router
+
+check grep -q "Bad configuration: The peer of the switch port 'ls-lrp1' (LRP peer: 'lrp1') has its own peer configuration: 'lrp0'" northd/ovn-northd.log
+
+AT_CLEANUP
+])