ripd: Do not overrun with more ECMP paths than Zebra supports

Let's say FRR is compiled with ECMP max 16, we enter `allow-ecmp 10`, but
Zebra supports only 4.

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

diff --git a/ripd/rip_zebra.c b/ripd/rip_zebra.c
index 698dcb982d8f5b9affdaa59a542228d71fb5ea96..834c7d2d6519a96b87ac29fb0131da32aed64589 100644 (file)
--- a/ripd/rip_zebra.c
+++ b/ripd/rip_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 rip_zebra_ipv4_send(struct rip *rip, struct route_node *rp,
@@ -30,7 +31,7 @@ static void rip_zebra_ipv4_send(struct rip *rip, struct route_node *rp,
        struct zapi_nexthop *api_nh;
        struct listnode *listnode = NULL;
        struct rip_info *rinfo = NULL;
-       int count = 0;
+       uint32_t count = 0;
 
        memset(&api, 0, sizeof(api));
        api.vrf_id = rip->vrf->vrf_id;
@@ -39,7 +40,7 @@ static void rip_zebra_ipv4_send(struct rip *rip, struct route_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 = rip->vrf->vrf_id;
@@ -227,6 +228,11 @@ zclient_handler *const rip_handlers[] = {
        [ZEBRA_REDISTRIBUTE_ROUTE_DEL] = rip_zebra_read_route,
 };
 
+static void rip_zebra_capabilities(struct zclient_capabilities *cap)
+{
+       zebra_ecmp_count = MIN(cap->ecmp, zebra_ecmp_count);
+}
+
 void rip_zclient_init(struct event_loop *master)
 {
        /* Set default value to the zebra client structure. */
@@ -234,6 +240,7 @@ void rip_zclient_init(struct event_loop *master)
                              array_size(rip_handlers));
        zclient_init(zclient, ZEBRA_ROUTE_RIP, 0, &ripd_privs);
        zclient->zebra_connected = rip_zebra_connected;
+       zclient->zebra_capabilities = rip_zebra_capabilities;
 }
 
 void rip_zclient_stop(void)