controller: Support learning routes per iface.

Previously we just assumed that if a LR had multiple LRPs bound to the
local chassis that all routes where valid for all of these LRPs.
This commit handles a previous option in ovn-nb that allowes the user to
specify the interface name that a route needs to use to be acceptable
for a given LRP.
The users can then have a 1:1 relationship between LRPs and interfaces
to allow ovn-controller to determine which route belongs to which LRP.

Signed-off-by: Felix Huettner <felix.huettner@stackit.cloud>
Signed-off-by: 0-day Robot <robot@bytheb.org>

controller/route-exchange-netlink.c

@@ -222,6 +222,7 @@ handle_route_msg_delete_routes(const struct route_table_msg *msg, void *data)
             rr->addr = rd->rta_dst;
             rr->plen = rd->rtm_dst_len;
             rr->nexthop = nexthop->addr;
+            memcpy(rr->ifname, nexthop->ifname, IFNAMSIZ);
         }
         return;
     }

controller/route-exchange-netlink.h

@@ -18,6 +18,7 @@
 #include <stdint.h>
 #include "openvswitch/hmap.h"
 #include <netinet/in.h>
+#include <net/if.h>
 
 /* This value is arbitrary but currently unused.
  * See https://github.com/iproute2/iproute2/blob/main/etc/iproute2/rt_protos */
@@ -31,6 +32,7 @@ struct re_nl_received_route_node {
     struct in6_addr addr;
     unsigned int plen;
     struct in6_addr nexthop;
+    char ifname[IFNAMSIZ];
 };
 
 int re_nl_create_vrf(const char *ifname, uint32_t table_id);

controller/route-exchange.c

@@ -101,7 +101,7 @@ route_erase_entry(struct route_entry *route_e)
 static void
 sb_sync_learned_routes(const struct sbrec_datapath_binding *datapath,
                        const struct hmap *learned_routes,
-                       const struct sset *bound_ports,
+                       const struct smap *bound_ports,
                        struct ovsdb_idl_txn *ovnsb_idl_txn,
                        struct ovsdb_idl_index *sbrec_learned_route_by_datapath,
                        struct ovsdb_idl_index *sbrec_port_binding_by_name)
@@ -116,8 +116,9 @@ sb_sync_learned_routes(const struct sbrec_datapath_binding *datapath,
     SBREC_LEARNED_ROUTE_FOR_EACH_EQUAL (sb_route, filter,
                                         sbrec_learned_route_by_datapath) {
         /* If the port is not local we don't care about it.
-         * Some other ovn-controller will handle it. */
-        if (!sset_contains(bound_ports,
+         * Some other ovn-controller will handle it.
+         * We may not use smap_get since the value might be validly NULL. */
+        if (!smap_get_node(bound_ports,
                            sb_route->logical_port->logical_port)) {
             continue;
         }
@@ -137,14 +138,22 @@ sb_sync_learned_routes(const struct sbrec_datapath_binding *datapath,
                                                learned_route->plen);
         char *nexthop = normalize_v46(&learned_route->nexthop);
 
-        const char *logical_port_name;
-        SSET_FOR_EACH (logical_port_name, bound_ports) {
+        struct smap_node *port_node;
+        SMAP_FOR_EACH (port_node, bound_ports) {
+            /* The user specified an ifname, but we learned it on a different
+             * port. */
+            if (port_node->value && strcmp(port_node->value,
+                                           learned_route->ifname)) {
+                continue;
+            }
+
             const struct sbrec_port_binding *logical_port =
                 lport_lookup_by_name(sbrec_port_binding_by_name,
-                                     logical_port_name);
+                                     port_node->key);
             if (!logical_port) {
                 continue;
             }
+
             route_e = route_lookup_or_add(&sync_routes,
                 datapath,
                 logical_port, ip_prefix, nexthop);

controller/route.c

@@ -83,14 +83,16 @@ advertise_datapath_cleanup(struct advertise_datapath_entry *ad)
         free(ar);
     }
     hmap_destroy(&ad->routes);
-    sset_destroy(&ad->bound_ports);
+    smap_destroy(&ad->bound_ports);
     free(ad);
 }
 
 void
 route_run(struct route_ctx_in *r_ctx_in,
           struct route_ctx_out *r_ctx_out)
 {
+    tracked_datapaths_destroy(r_ctx_out->tracked_re_datapaths);
+
     const struct local_datapath *ld;
     HMAP_FOR_EACH (ld, hmap_node, r_ctx_in->local_datapaths) {
         if (!ld->n_peer_ports || ld->is_switch) {
@@ -102,7 +104,7 @@ route_run(struct route_ctx_in *r_ctx_in,
         ad->key = ld->datapath->tunnel_key;
         ad->db = ld->datapath;
         hmap_init(&ad->routes);
-        sset_init(&ad->bound_ports);
+        smap_init(&ad->bound_ports);
 
         /* This is a LR datapath, find LRPs with route exchange options
          * that are bound locally. */
@@ -122,8 +124,12 @@ route_run(struct route_ctx_in *r_ctx_in,
                                           "maintain-vrf", false);
             ad->use_netns |= smap_get_bool(&repb->options,
                                        "use-netns", false);
+            char *ifname = nullable_xstrdup(
+                                    smap_get(&repb->options,
+                                             "dynamic-routing-ifname"));
             relevant_datapath = true;
-            sset_add(&ad->bound_ports, local_peer->logical_port);
+            smap_add_nocopy(&ad->bound_ports,
+                            xstrdup(local_peer->logical_port), ifname);
         }
 
         if (!relevant_datapath) {

controller/route.h

@@ -19,6 +19,7 @@
 #include <netinet/in.h>
 #include "openvswitch/hmap.h"
 #include "sset.h"
+#include "smap.h"
 
 struct hmap;
 struct ovsdb_idl_index;
@@ -51,8 +52,9 @@ struct advertise_datapath_entry {
     bool use_netns;
     struct hmap routes;
     /* the name of the port bindings locally bound for this datapath and
-     * running route exchange logic. */
-    struct sset bound_ports;
+     * running route exchange logic.
+     * The key is the port name and the value is the ifname if set. */
+    struct smap bound_ports;
 };
 
 struct advertise_route_entry {

tests/system-ovn.at

@@ -14920,6 +14920,17 @@ AT_CHECK_UNQUOTED([ovn-sbctl --columns ip_prefix,nexthop,logical_port --bare fin
 $lp
 ])
 
+# by setting a learning interface filter we will now forget about this route
+check ovn-nbctl --wait=hv set Logical_Router_Port internet-phys \
+      options:dynamic-routing-ifname=thisdoesnotexist
+check_row_count Learned_Route 0
+
+# chaning it to "lo" will allow us to learn the route again
+check ovn-nbctl --wait=hv set Logical_Router_Port internet-phys \
+      options:dynamic-routing-ifname=lo
+check_row_count Learned_Route 1
+
+
 OVS_APP_EXIT_AND_WAIT([ovn-controller])
 
 as ovn-sb
@@ -15130,14 +15141,24 @@ check ip route add 233.252.0.0/24 via 192.168.10.10 dev lo onlink vrf ovnvrf1337
 # for now we trigger a recompute as route watching is not yet implemented
 check ovn-appctl -t ovn-controller inc-engine/recompute
 check ovn-nbctl --wait=hv sync
-check_row_count Learned_Route 2
+check_row_count Learned_Route 1
 lp=$(ovn-sbctl --bare --columns _uuid list port_binding internet-phys)
-AT_CHECK_UNQUOTED([ovn-sbctl --columns ip_prefix,nexthop,logical_port --bare find Learned_Route logical_port=$lp], [0], [dnl
+AT_CHECK_UNQUOTED([ovn-sbctl --columns ip_prefix,nexthop,logical_port --bare find Learned_Route], [0], [dnl
 233.252.0.0/24
 192.168.10.10
 $lp
 ])
 
+# by setting a learning interface filter we will now forget about this route
+check ovn-nbctl --wait=hv set Logical_Router_Port internet-phys \
+      options:dynamic-routing-ifname=thisdoesnotexist
+check_row_count Learned_Route 0
+
+# chaning it to "lo" will allow us to learn the route again
+check ovn-nbctl --wait=hv set Logical_Router_Port internet-phys \
+      options:dynamic-routing-ifname=lo
+check_row_count Learned_Route 1
+
 as ovn-sb
 OVS_APP_EXIT_AND_WAIT([ovsdb-server])