For each vrf we use we open a netlink watcher.
This allows us to reconcile on changed route entries from outside
routing agents.

Signed-off-by: Felix Huettner <[email protected]>
---
v5->v6:
  * addressed review comments

 controller/automake.mk               |   7 +-
 controller/ovn-controller.c          |  51 ++++++-
 controller/route-exchange.c          |   6 +-
 controller/route-exchange.h          |   3 +
 controller/route-table-notify-stub.c |  56 ++++++++
 controller/route-table-notify.c      | 198 +++++++++++++++++++++++++++
 controller/route-table-notify.h      |  44 ++++++
 tests/system-ovn.at                  |   4 -
 8 files changed, 360 insertions(+), 9 deletions(-)
 create mode 100644 controller/route-table-notify-stub.c
 create mode 100644 controller/route-table-notify.c
 create mode 100644 controller/route-table-notify.h

diff --git a/controller/automake.mk b/controller/automake.mk
index fa3083d2d..c789c313c 100644
--- a/controller/automake.mk
+++ b/controller/automake.mk
@@ -55,6 +55,7 @@ controller_ovn_controller_SOURCES = \
        controller/ecmp-next-hop-monitor.h \
        controller/ecmp-next-hop-monitor.c \
        controller/route-exchange.h \
+       controller/route-table-notify.h \
        controller/route.h \
        controller/route.c
 
@@ -62,10 +63,12 @@ if HAVE_NETLINK
 controller_ovn_controller_SOURCES += \
        controller/route-exchange-netlink.h \
        controller/route-exchange-netlink.c \
-       controller/route-exchange.c
+       controller/route-exchange.c \
+       controller/route-table-notify.c
 else
 controller_ovn_controller_SOURCES += \
-       controller/route-exchange-stub.c
+       controller/route-exchange-stub.c \
+       controller/route-table-notify-stub.c
 endif
 
 controller_ovn_controller_LDADD = lib/libovn.la $(OVS_LIBDIR)/libopenvswitch.la
diff --git a/controller/ovn-controller.c b/controller/ovn-controller.c
index 5d54fc04d..e819733e9 100644
--- a/controller/ovn-controller.c
+++ b/controller/ovn-controller.c
@@ -90,6 +90,7 @@
 #include "ovn-dns.h"
 #include "route.h"
 #include "route-exchange.h"
+#include "route-table-notify.h"
 
 VLOG_DEFINE_THIS_MODULE(main);
 
@@ -5205,10 +5206,16 @@ en_route_exchange_run(struct engine_node *node, void 
*data)
         .sbrec_port_binding_by_name = sbrec_port_binding_by_name,
         .announce_routes = &route_data->announce_routes,
     };
-    struct route_exchange_ctx_out r_ctx_out = {
-    };
+    struct route_exchange_ctx_out r_ctx_out = {};
+
+    hmap_init(&r_ctx_out.route_table_watches);
 
     route_exchange_run(&r_ctx_in, &r_ctx_out);
+    route_table_notify_update_watches(&r_ctx_out.route_table_watches);
+
+    route_table_watch_request_cleanup(&r_ctx_out.route_table_watches);
+    hmap_destroy(&r_ctx_out.route_table_watches);
+
     engine_set_node_state(node, EN_UPDATED);
 }
 
@@ -5226,6 +5233,38 @@ static void
 en_route_exchange_cleanup(void *data OVS_UNUSED)
 {}
 
+struct ed_type_route_table_notify {
+    /* For incremental processing this could be tracked per datapath in
+     * the future. */
+    bool changed;
+};
+
+static void
+en_route_table_notify_run(struct engine_node *node, void *data)
+{
+    struct ed_type_route_table_notify *rtn = data;
+    if (rtn->changed) {
+        engine_set_node_state(node, EN_UPDATED);
+    } else {
+        engine_set_node_state(node, EN_UNCHANGED);
+    }
+    rtn->changed = false;
+}
+
+
+static void *
+en_route_table_notify_init(struct engine_node *node OVS_UNUSED,
+                       struct engine_arg *arg OVS_UNUSED)
+{
+    struct ed_type_route_table_notify *rtn = xzalloc(sizeof *rtn);
+    rtn->changed = true;
+    return rtn;
+}
+
+static void
+en_route_table_notify_cleanup(void *data OVS_UNUSED)
+{}
+
 /* Returns false if the northd internal version stored in SB_Global
  * and ovn-controller internal version don't match.
  */
@@ -5525,6 +5564,7 @@ main(int argc, char *argv[])
     ENGINE_NODE(bfd_chassis, "bfd_chassis");
     ENGINE_NODE(dns_cache, "dns_cache");
     ENGINE_NODE(route, "route");
+    ENGINE_NODE(route_table_notify, "route_table_notify");
     ENGINE_NODE(route_exchange, "route_exchange");
 
 #define SB_NODE(NAME, NAME_STR) ENGINE_NODE_SB(NAME, NAME_STR);
@@ -5562,6 +5602,7 @@ main(int argc, char *argv[])
                      engine_noop_handler);
     engine_add_input(&en_route_exchange, &en_sb_port_binding,
                      engine_noop_handler);
+    engine_add_input(&en_route_exchange, &en_route_table_notify, NULL);
 
     engine_add_input(&en_addr_sets, &en_sb_address_set,
                      addr_sets_sb_address_set_handler);
@@ -6080,6 +6121,10 @@ main(int argc, char *argv[])
                                &transport_zones,
                                bridge_table);
 
+                    struct ed_type_route_table_notify *rtn =
+                        engine_get_internal_data(&en_route_table_notify);
+                    rtn->changed = route_table_notify_run();
+
                     stopwatch_start(CONTROLLER_LOOP_STOPWATCH_NAME,
                                     time_msec());
 
@@ -6362,6 +6407,7 @@ main(int argc, char *argv[])
             }
 
             binding_wait();
+            route_table_notify_wait();
         }
 
         unixctl_server_run(unixctl);
@@ -6516,6 +6562,7 @@ loop_done:
     ovsrcu_exit();
     dns_resolve_destroy();
     route_exchange_destroy();
+    route_table_notify_destroy();
 
     exit(retval);
 }
diff --git a/controller/route-exchange.c b/controller/route-exchange.c
index a1976234b..89d07eeb7 100644
--- a/controller/route-exchange.c
+++ b/controller/route-exchange.c
@@ -29,6 +29,7 @@
 #include "ha-chassis.h"
 #include "local_data.h"
 #include "route.h"
+#include "route-table-notify.h"
 #include "route-exchange.h"
 #include "route-exchange-netlink.h"
 
@@ -167,7 +168,7 @@ sb_sync_learned_routes(const struct ovs_list 
*learned_routes,
 
 void
 route_exchange_run(struct route_exchange_ctx_in *r_ctx_in,
-                   struct route_exchange_ctx_out *r_ctx_out OVS_UNUSED)
+                   struct route_exchange_ctx_out *r_ctx_out)
 {
     struct sset old_maintained_vrfs = SSET_INITIALIZER(&old_maintained_vrfs);
     sset_swap(&_maintained_vrfs, &old_maintained_vrfs);
@@ -209,6 +210,9 @@ route_exchange_run(struct route_exchange_ctx_in *r_ctx_in,
                                r_ctx_in->sbrec_port_binding_by_name,
                                r_ctx_in->sbrec_learned_route_by_datapath);
 
+        route_table_add_watch_request(
+            &r_ctx_out->route_table_watches, table_id);
+
         re_nl_learned_routes_destroy(&received_routes);
     }
 
diff --git a/controller/route-exchange.h b/controller/route-exchange.h
index 66d8f3945..1e1a09da3 100644
--- a/controller/route-exchange.h
+++ b/controller/route-exchange.h
@@ -18,6 +18,8 @@
 #ifndef ROUTE_EXCHANGE_H
 #define ROUTE_EXCHANGE_H 1
 
+#include "openvswitch/hmap.h"
+
 struct route_exchange_ctx_in {
     struct ovsdb_idl_txn *ovnsb_idl_txn;
     struct ovsdb_idl_index *sbrec_port_binding_by_name;
@@ -27,6 +29,7 @@ struct route_exchange_ctx_in {
 };
 
 struct route_exchange_ctx_out {
+    struct hmap route_table_watches;
 };
 
 void route_exchange_run(struct route_exchange_ctx_in *,
diff --git a/controller/route-table-notify-stub.c 
b/controller/route-table-notify-stub.c
new file mode 100644
index 000000000..f58897f03
--- /dev/null
+++ b/controller/route-table-notify-stub.c
@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2025, STACKIT GmbH & Co. KG
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <config.h>
+
+#include <stdbool.h>
+
+#include "openvswitch/compiler.h"
+#include "route-table-notify.h"
+
+bool
+route_table_notify_run(void)
+{
+    return false;
+}
+
+void
+route_table_notify_wait(void)
+{
+}
+
+void
+route_table_add_watch_request(struct hmap *route_table_watches OVS_UNUSED,
+                              uint32_t table_id OVS_UNUSED)
+{
+}
+
+void
+route_table_watch_request_cleanup(struct hmap *route_table_watches OVS_UNUSED)
+{
+}
+
+void
+route_table_notify_update_watches(
+    const struct hmap *route_table_watches OVS_UNUSED)
+{
+}
+
+void
+route_table_notify_destroy(void)
+{
+}
+
diff --git a/controller/route-table-notify.c b/controller/route-table-notify.c
new file mode 100644
index 000000000..b79f50eba
--- /dev/null
+++ b/controller/route-table-notify.c
@@ -0,0 +1,198 @@
+/*
+ * Copyright (c) 2025, STACKIT GmbH & Co. KG
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <config.h>
+
+#include <net/if.h>
+#include <linux/rtnetlink.h>
+
+#include "netlink-notifier.h"
+#include "openvswitch/vlog.h"
+
+#include "binding.h"
+#include "hash.h"
+#include "hmapx.h"
+#include "route-table.h"
+#include "route.h"
+#include "route-table-notify.h"
+#include "route-exchange-netlink.h"
+
+VLOG_DEFINE_THIS_MODULE(route_table_notify);
+
+struct route_table_watch_request {
+    struct hmap_node node;
+    uint32_t table_id;
+};
+
+struct route_table_watch_entry {
+    struct hmap_node node;
+    uint32_t table_id;
+    struct nln *nln;
+    struct nln_notifier *route_notifier;
+    struct nln_notifier *route6_notifier;
+};
+
+static struct hmap watches = HMAP_INITIALIZER(&watches);
+static bool any_route_table_changed;
+static struct route_table_msg rtmsg;
+
+static uint32_t
+route_table_notify_hash_watch(uint32_t table_id)
+{
+    return hash_add(0, table_id);
+}
+
+void
+route_table_add_watch_request(struct hmap *route_table_watches,
+                              uint32_t table_id)
+{
+    struct route_table_watch_request *wr = xzalloc(sizeof *wr);
+    wr->table_id = table_id;
+    hmap_insert(route_table_watches, &wr->node,
+                route_table_notify_hash_watch(wr->table_id));
+}
+
+void
+route_table_watch_request_cleanup(struct hmap *route_table_watches)
+{
+    struct route_table_watch_request *wr;
+    HMAP_FOR_EACH_POP (wr, node, route_table_watches) {
+        free(wr);
+    }
+}
+
+static struct route_table_watch_entry *
+find_watch_entry(uint32_t table_id)
+{
+    struct route_table_watch_entry *we;
+    uint32_t hash = route_table_notify_hash_watch(table_id);
+    HMAP_FOR_EACH_WITH_HASH (we, node, hash, &watches) {
+        if (table_id == we->table_id) {
+            return we;
+        }
+    }
+    return NULL;
+}
+
+static void
+route_table_change(const void *change_, void *aux OVS_UNUSED)
+{
+    const struct route_table_msg *change = change_;
+    if (change && change->rd.rtm_protocol != RTPROT_OVN) {
+        if (find_watch_entry(change->rd.rta_table_id)) {
+            any_route_table_changed = true;
+        }
+    }
+}
+
+static void
+add_watch_entry(uint32_t table_id)
+{
+    struct route_table_watch_entry *we;
+    uint32_t hash = route_table_notify_hash_watch(table_id);
+    we = xzalloc(sizeof *we);
+    we->table_id = table_id;
+    VLOG_INFO("Registering new route table watcher for table %d.",
+             table_id);
+    we->nln = nln_create(NETLINK_ROUTE, route_table_parse, &rtmsg);
+
+    we->route_notifier =
+        nln_notifier_create(we->nln, RTNLGRP_IPV4_ROUTE,
+                            route_table_change, NULL);
+    if (!we->route_notifier) {
+        static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 1);
+        VLOG_WARN_RL(&rl, "Failed to create ipv4 route table watcher for "
+                  "table %d. We will miss routing table updates.", table_id);
+    }
+
+    we->route6_notifier =
+        nln_notifier_create(we->nln, RTNLGRP_IPV6_ROUTE,
+                            route_table_change, NULL);
+    if (!we->route6_notifier) {
+        static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 1);
+        VLOG_WARN_RL(&rl, "Failed to create ipv6 route table watcher for "
+                  "table %d. We will miss routing table updates.", table_id);
+    }
+
+    hmap_insert(&watches, &we->node, hash);
+}
+
+static void
+remove_watch_entry(struct route_table_watch_entry *we)
+{
+    hmap_remove(&watches, &we->node);
+    VLOG_INFO("Removing route table watcher for table %d.", we->table_id);
+    nln_notifier_destroy(we->route_notifier);
+    nln_notifier_destroy(we->route6_notifier);
+    nln_destroy(we->nln);
+    free(we);
+}
+
+bool
+route_table_notify_run(void)
+{
+    any_route_table_changed = false;
+
+    struct route_table_watch_entry *we;
+    HMAP_FOR_EACH (we, node, &watches) {
+        nln_run(we->nln);
+    }
+
+    return any_route_table_changed;
+}
+
+void
+route_table_notify_wait(void)
+{
+    struct route_table_watch_entry *we;
+    HMAP_FOR_EACH (we, node, &watches) {
+        nln_wait(we->nln);
+    }
+}
+
+void
+route_table_notify_update_watches(const struct hmap *route_table_watches)
+{
+    struct hmapx sync_watches = HMAPX_INITIALIZER(&sync_watches);
+    struct route_table_watch_entry *we;
+    HMAP_FOR_EACH (we, node, &watches) {
+        hmapx_add(&sync_watches, we);
+    }
+
+    struct route_table_watch_request *wr;
+    HMAP_FOR_EACH (wr, node, route_table_watches) {
+        we = find_watch_entry(wr->table_id);
+        if (we) {
+            hmapx_find_and_delete(&sync_watches, we);
+        } else {
+            add_watch_entry(wr->table_id);
+        }
+    }
+
+    struct hmapx_node *node;
+    HMAPX_FOR_EACH (node, &sync_watches) {
+        remove_watch_entry(node->data);
+    }
+}
+
+void
+route_table_notify_destroy(void)
+{
+    struct route_table_watch_entry *we;
+    HMAP_FOR_EACH_SAFE (we, node, &watches) {
+        remove_watch_entry(we);
+    }
+}
diff --git a/controller/route-table-notify.h b/controller/route-table-notify.h
new file mode 100644
index 000000000..a2bc05a49
--- /dev/null
+++ b/controller/route-table-notify.h
@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2025, STACKIT GmbH & Co. KG
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ROUTE_TABLE_NOTIFY_H
+#define ROUTE_TABLE_NOTIFY_H 1
+
+#include <stdbool.h>
+#include "openvswitch/hmap.h"
+
+/* Returns true if any route table has changed enough that we need
+ * to learn new routes. */
+bool route_table_notify_run(void);
+void route_table_notify_wait(void);
+
+/* Add a watch request to the hmap. The hmap should later be passed to
+ * route_table_notify_update_watches*/
+void route_table_add_watch_request(struct hmap *route_table_watches,
+                                   uint32_t table_id);
+
+/* Cleanup all watch request in the provided hmap that where added using
+ * route_table_add_watch_request. */
+void route_table_watch_request_cleanup(struct hmap *route_table_watches);
+
+/* Updates the list of route table watches that are currently active.
+ * hmap should contain struct route_table_watch_request */
+void route_table_notify_update_watches(const struct hmap *route_table_watches);
+
+/* Cleans up all route table watches. */
+void route_table_notify_destroy(void);
+
+#endif /* ROUTE_TABLE_NOTIFY_H */
diff --git a/tests/system-ovn.at b/tests/system-ovn.at
index a13ee4bbf..8b3238a96 100644
--- a/tests/system-ovn.at
+++ b/tests/system-ovn.at
@@ -15677,8 +15677,6 @@ blackhole 198.51.100.0/24 proto 84 metric 1000])
 # Now we test route learning.
 check_row_count Learned_Route 0
 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 1
 lp=$(fetch_column port_binding _uuid logical_port=internet-phys)
@@ -15925,8 +15923,6 @@ blackhole 198.51.100.0/24 proto 84 metric 1000])
 # Now we test route learning.
 check_row_count Learned_Route 0
 check ip route add 233.252.0.0/24 via 192.168.10.10 dev lo onlink vrf 
ovnvrf1337
-# For now we trigger a recompute as route watching is not yet implemented.
-check ovn-appctl -t ovn-controller inc-engine/recompute
 check ovn-nbctl --wait=hv sync
 check_row_count Learned_Route 1
 lp=$(fetch_column port_binding _uuid logical_port=internet-phys)
-- 
2.47.1


_______________________________________________
dev mailing list
[email protected]
https://mail.openvswitch.org/mailman/listinfo/ovs-dev

Reply via email to