ripng: Implement `allow-ecmp X` command

A port of ripd implementation for ripngd implemented by 75fce4645a7cf0a93ef0109d69365f51b84bc47c.

Signed-off-by: Donatas Abraitis <donatas@opensourcerouting.org>

diff --git a/ripngd/ripng_cli.c b/ripngd/ripng_cli.c
index 5e59dfd2c409eba23c8b3ac0afbe4de4282e18cd..9a96e29313d6858c742be44d95275a9e3b8c88bb 100644 (file)
--- a/ripngd/ripng_cli.c
+++ b/ripngd/ripng_cli.c
@@ -85,14 +85,32 @@ void cli_show_router_ripng(struct vty *vty, const struct lyd_node *dnode,
 /*
  * XPath: /frr-ripngd:ripngd/instance/allow-ecmp
  */
-DEFPY_YANG (ripng_allow_ecmp,
-       ripng_allow_ecmp_cmd,
-       "[no] allow-ecmp",
-       NO_STR
-       "Allow Equal Cost MultiPath\n")
+DEFUN_YANG (ripng_allow_ecmp,
+            ripng_allow_ecmp_cmd,
+            "allow-ecmp [" CMD_RANGE_STR(1, MULTIPATH_NUM) "]",
+            "Allow Equal Cost MultiPath\n"
+            "Number of paths\n")
+{
+       int idx_number = 0;
+       char mpaths[3] = {};
+       uint32_t paths = MULTIPATH_NUM;
+
+    if (argv_find(argv, argc, CMD_RANGE_STR(1, MULTIPATH_NUM), &idx_number))
+               paths = strtol(argv[idx_number]->arg, NULL, 10);
+       snprintf(mpaths, sizeof(mpaths), "%u", paths);
+
+       nb_cli_enqueue_change(vty, "./allow-ecmp", NB_OP_MODIFY, mpaths);
+
+       return nb_cli_apply_changes(vty, NULL);
+}
+
+DEFUN_YANG (no_ripng_allow_ecmp,
+            no_ripng_allow_ecmp_cmd,
+            "no allow-ecmp [" CMD_RANGE_STR(1, MULTIPATH_NUM) "]", NO_STR
+            "Allow Equal Cost MultiPath\n"
+            "Number of paths\n")
 {
-       nb_cli_enqueue_change(vty, "./allow-ecmp", NB_OP_MODIFY,
-                             no ? "false" : "true");
+       nb_cli_enqueue_change(vty, "./allow-ecmp", NB_OP_MODIFY, 0);
 
        return nb_cli_apply_changes(vty, NULL);
 }
@@ -100,10 +118,14 @@ DEFPY_YANG (ripng_allow_ecmp,
 void cli_show_ripng_allow_ecmp(struct vty *vty, const struct lyd_node *dnode,
                               bool show_defaults)
 {
-       if (!yang_dnode_get_bool(dnode, NULL))
-               vty_out(vty, " no");
+       uint8_t paths;
+
+       paths = yang_dnode_get_uint8(dnode, NULL);
 
-       vty_out(vty, " allow-ecmp\n");
+       if (!paths)
+               vty_out(vty, " no allow-ecmp\n");
+       else
+               vty_out(vty, " allow-ecmp %d\n", paths);
 }
 
 /*
@@ -547,6 +569,7 @@ void ripng_cli_init(void)
        install_element(RIPNG_NODE, &ripng_no_ipv6_distribute_list_cmd);
 
        install_element(RIPNG_NODE, &ripng_allow_ecmp_cmd);
+       install_element(RIPNG_NODE, &no_ripng_allow_ecmp_cmd);
        install_element(RIPNG_NODE, &ripng_default_information_originate_cmd);
        install_element(RIPNG_NODE, &ripng_default_metric_cmd);
        install_element(RIPNG_NODE, &no_ripng_default_metric_cmd);

diff --git a/ripngd/ripng_nb_config.c b/ripngd/ripng_nb_config.c
index 30f707e061e989266a36e0a2c030a5a8ef2e30ac..de723193543e53a7a803903f3bb366f0f6d2fa18 100644 (file)
--- a/ripngd/ripng_nb_config.c
+++ b/ripngd/ripng_nb_config.c
@@ -129,9 +129,13 @@ int ripngd_instance_allow_ecmp_modify(struct nb_cb_modify_args *args)
                return NB_OK;
 
        ripng = nb_running_get_entry(args->dnode, NULL, true);
-       ripng->ecmp = yang_dnode_get_bool(args->dnode, NULL);
-       if (!ripng->ecmp)
+       ripng->ecmp = yang_dnode_get_uint8(args->dnode, NULL);
+       if (!ripng->ecmp) {
                ripng_ecmp_disable(ripng);
+               return NB_OK;
+       }
+
+       ripng_ecmp_change(ripng);
 
        return NB_OK;
 }

diff --git a/ripngd/ripng_zebra.c b/ripngd/ripng_zebra.c
index d974d65df5e4fb27be09cac9bea698d7ed266e29..6122c4255ce50ac34665972b955c63e073378ffc 100644 (file)
--- a/ripngd/ripng_zebra.c
+++ b/ripngd/ripng_zebra.c
@@ -20,6 +20,7 @@
 
 /* All information about zebra. */
 struct zclient *zclient = NULL;
+uint32_t zebra_ecmp_count = MULTIPATH_NUM;
 
 /* Send ECMP routes to zebra. */
 static void ripng_zebra_ipv6_send(struct ripng *ripng, struct agg_node *rp,
@@ -30,7 +31,7 @@ static void ripng_zebra_ipv6_send(struct ripng *ripng, struct agg_node *rp,
        struct zapi_nexthop *api_nh;
        struct listnode *listnode = NULL;
        struct ripng_info *rinfo = NULL;
-       int count = 0;
+       uint32_t count = 0;
        const struct prefix *p = agg_node_get_prefix(rp);
 
        memset(&api, 0, sizeof(api));
@@ -41,7 +42,7 @@ static void ripng_zebra_ipv6_send(struct ripng *ripng, struct agg_node *rp,
 
        SET_FLAG(api.message, ZAPI_MESSAGE_NEXTHOP);
        for (ALL_LIST_ELEMENTS_RO(list, listnode, rinfo)) {
-               if (count >= MULTIPATH_NUM)
+               if (count >= zebra_ecmp_count)
                        break;
                api_nh = &api.nexthops[count];
                api_nh->vrf_id = ripng->vrf->vrf_id;
@@ -227,6 +228,11 @@ static zclient_handler *const ripng_handlers[] = {
        [ZEBRA_REDISTRIBUTE_ROUTE_DEL] = ripng_zebra_read_route,
 };
 
+static void ripng_zebra_capabilities(struct zclient_capabilities *cap)
+{
+       zebra_ecmp_count = MIN(cap->ecmp, zebra_ecmp_count);
+}
+
 /* Initialize zebra structure and it's commands. */
 void zebra_init(struct event_loop *master)
 {
@@ -236,6 +242,7 @@ void zebra_init(struct event_loop *master)
        zclient_init(zclient, ZEBRA_ROUTE_RIPNG, 0, &ripngd_privs);
 
        zclient->zebra_connected = ripng_zebra_connected;
+       zclient->zebra_capabilities = ripng_zebra_capabilities;
 }
 
 void ripng_zebra_stop(void)

diff --git a/ripngd/ripngd.c b/ripngd/ripngd.c
index 2f6409a70d31d6ddf5cb55dadc91161bafe46a5b..7269e76656b8f487f46ff77de8f8a6f7cc2aecd4 100644 (file)
--- a/ripngd/ripngd.c
+++ b/ripngd/ripngd.c
@@ -443,7 +443,10 @@ struct ripng_info *ripng_ecmp_add(struct ripng *ripng,
 {
        struct agg_node *rp = rinfo_new->rp;
        struct ripng_info *rinfo = NULL;
+       struct ripng_info *rinfo_exist = NULL;
        struct list *list = NULL;
+       struct listnode *node = NULL;
+       struct listnode *nnode = NULL;
 
        if (rp->info == NULL)
                rp->info = list_new();
@@ -454,6 +457,33 @@ struct ripng_info *ripng_ecmp_add(struct ripng *ripng,
        if (listcount(list) && !ripng->ecmp)
                return NULL;
 
+       /* Add or replace an existing ECMP path with lower neighbor IP */
+       if (listcount(list) && listcount(list) >= ripng->ecmp) {
+               struct ripng_info *from_highest = NULL;
+
+               /* Find the rip_info struct that has the highest nexthop IP */
+               for (ALL_LIST_ELEMENTS(list, node, nnode, rinfo_exist))
+                       if (!from_highest ||
+                           (from_highest &&
+                            IPV6_ADDR_CMP(&rinfo_exist->from,
+                                          &from_highest->from) > 0)) {
+                               from_highest = rinfo_exist;
+                       }
+
+               /* If we have a route in ECMP group, delete the old
+                * one that has a higher next-hop address. Lower IP is
+                * preferred.
+                */
+               if (ripng->ecmp > 1 && from_highest &&
+                   IPV6_ADDR_CMP(&from_highest->from, &rinfo_new->from) > 0) {
+                       ripng_ecmp_delete(ripng, from_highest);
+                       goto add_or_replace;
+               }
+
+               return NULL;
+       }
+
+add_or_replace:
        rinfo = ripng_info_new();
        memcpy(rinfo, rinfo_new, sizeof(struct ripng_info));
        listnode_add(list, rinfo);
@@ -475,6 +505,36 @@ struct ripng_info *ripng_ecmp_add(struct ripng *ripng,
        return rinfo;
 }
 
+/* Update ECMP routes to zebra when `allow-ecmp` changed. */
+void ripng_ecmp_change(struct ripng *ripng)
+{
+       struct agg_node *rp;
+       struct ripng_info *rinfo;
+       struct list *list;
+       struct listnode *node, *nextnode;
+
+       for (rp = agg_route_top(ripng->table); rp; rp = agg_route_next(rp)) {
+               list = rp->info;
+               if (list && listcount(list) > 1) {
+                       while (listcount(list) > ripng->ecmp) {
+                               struct ripng_info *from_highest = NULL;
+
+                               for (ALL_LIST_ELEMENTS(list, node, nextnode,
+                                                      rinfo)) {
+                                       if (!from_highest ||
+                                           (from_highest &&
+                                            IPV6_ADDR_CMP(
+                                                    &rinfo->from,
+                                                    &from_highest->from) > 0))
+                                               from_highest = rinfo;
+                               }
+
+                               ripng_ecmp_delete(ripng, from_highest);
+                       }
+               }
+       }
+}
+
 /* Replace the ECMP list with the new route.
  * RETURN: the new entry added in the list
  */
@@ -1814,7 +1874,7 @@ struct ripng *ripng_create(const char *vrf_name, struct vrf *vrf, int socket)
                "%s/timers/flush-interval", RIPNG_INSTANCE);
        ripng->default_metric =
                yang_get_default_uint8("%s/default-metric", RIPNG_INSTANCE);
-       ripng->ecmp = yang_get_default_bool("%s/allow-ecmp", RIPNG_INSTANCE);
+       ripng->ecmp = yang_get_default_uint8("%s/allow-ecmp", RIPNG_INSTANCE);
 
        /* Make buffer.  */
        ripng->ibuf = stream_new(RIPNG_MAX_PACKET_SIZE * 5);

diff --git a/ripngd/ripngd.h b/ripngd/ripngd.h
index eefcb0ee69cba787feda3231985ce6d880c2e461..3d13097dd6accea00e6cf5ad49ddcf35f5dca3ae 100644 (file)
--- a/ripngd/ripngd.h
+++ b/ripngd/ripngd.h
@@ -130,7 +130,7 @@ struct ripng {
        struct event *t_triggered_interval;
 
        /* RIPng ECMP flag */
-       bool ecmp;
+       uint8_t ecmp;
 
        /* RIPng redistribute configuration. */
        struct {
@@ -429,6 +429,7 @@ extern struct ripng_info *ripng_ecmp_replace(struct ripng *ripng,
                                             struct ripng_info *rinfo);
 extern struct ripng_info *ripng_ecmp_delete(struct ripng *ripng,
                                            struct ripng_info *rinfo);
+extern void ripng_ecmp_change(struct ripng *ripng);
 
 extern void ripng_vrf_init(void);
 extern void ripng_vrf_terminate(void);

diff --git a/yang/frr-ripngd.yang b/yang/frr-ripngd.yang
index 7b2b135fb5695c71f15202ac174dd7d185d86ec1..4aeaf36400751f1636a24cededd2fdc0db0d7203 100644 (file)
--- a/yang/frr-ripngd.yang
+++ b/yang/frr-ripngd.yang
@@ -86,8 +86,8 @@ module frr-ripngd {
           "VRF name.";
       }
       leaf allow-ecmp {
-        type boolean;
-        default "false";
+        type uint8;
+        default 0;
         description
           "Allow equal-cost multi-path.";
       }