zebra: allow recursive resolution to use backup nexthops

Allow both primary and backup nexthops to be used in
recursive resolution processing.

Signed-off-by: Mark Stapp <mjs@voltanet.io>

diff --git a/zebra/zebra_nhg.c b/zebra/zebra_nhg.c
index ce5e6a54d78e3ddf4d5a00a19be847901189adb1..1fc2c30c3839ea940461b87ddbeb1bc6621c0b21 100644 (file)
--- a/zebra/zebra_nhg.c
+++ b/zebra/zebra_nhg.c
@@ -1926,8 +1926,13 @@ static int nexthop_active(afi_t afi, struct route_entry *re,
 
                        return 1;
                } else if (CHECK_FLAG(re->flags, ZEBRA_FLAG_ALLOW_RECURSION)) {
+                       struct nexthop_group *nhg;
+
                        resolved = 0;
-                       for (ALL_NEXTHOPS(match->nhe->nhg, newhop)) {
+
+                       /* Examine installed nexthops */
+                       nhg = &match->nhe->nhg;
+                       for (ALL_NEXTHOPS_PTR(nhg, newhop)) {
                                if (!CHECK_FLAG(match->status,
                                                ROUTE_ENTRY_INSTALLED))
                                        continue;
@@ -1945,6 +1950,29 @@ static int nexthop_active(afi_t afi, struct route_entry *re,
                                resolved = 1;
                        }
 
+                       /* Examine installed backup nexthops, if any */
+                       nhg = zebra_nhg_get_backup_nhg(match->nhe);
+                       if (nhg == NULL)
+                               goto done_with_match;
+
+                       for (ALL_NEXTHOPS_PTR(nhg, newhop)) {
+                               if (!CHECK_FLAG(match->status,
+                                               ROUTE_ENTRY_INSTALLED))
+                                       continue;
+                               if (!nexthop_valid_resolve(nexthop, newhop))
+                                       continue;
+
+                               if (IS_ZEBRA_DEBUG_NHG_DETAIL)
+                                       zlog_debug("%s: RECURSIVE match backup %p (%u), newhop %pNHv",
+                                                  __func__, match,
+                                                  match->nhe->id, newhop);
+
+                               SET_FLAG(nexthop->flags,
+                                        NEXTHOP_FLAG_RECURSIVE);
+                               nexthop_set_resolved(afi, newhop, nexthop);
+                               resolved = 1;
+                       }
+done_with_match:
                        if (resolved)
                                re->nexthop_mtu = match->mtu;
                        else if (IS_ZEBRA_DEBUG_RIB_DETAILED)
@@ -2143,17 +2171,20 @@ done:
 }
 
 /*
- * Process a list of nexthops, given the head of the list, determining
+ * Process a list of nexthops, given an nhg, determining
  * whether each one is ACTIVE/installable at this time.
  */
 static uint32_t nexthop_list_active_update(struct route_node *rn,
                                           struct route_entry *re,
-                                          struct nexthop *nexthop)
+                                          struct nexthop_group *nhg)
 {
        union g_addr prev_src;
        unsigned int prev_active, new_active;
        ifindex_t prev_index;
        uint32_t counter = 0;
+       struct nexthop *nexthop;
+
+       nexthop = nhg->nexthop;
 
        /* Process nexthops one-by-one */
        for ( ; nexthop; nexthop = nexthop->next) {
@@ -2236,7 +2267,7 @@ int nexthop_active_update(struct route_node *rn, struct route_entry *re)
        curr_nhe->id = 0;
 
        /* Process nexthops */
-       curr_active = nexthop_list_active_update(rn, re, curr_nhe->nhg.nexthop);
+       curr_active = nexthop_list_active_update(rn, re, &curr_nhe->nhg);
 
        if (IS_ZEBRA_DEBUG_NHG_DETAIL)
                zlog_debug("%s: re %p curr_active %u", __func__, re,
@@ -2247,7 +2278,7 @@ int nexthop_active_update(struct route_node *rn, struct route_entry *re)
                goto backups_done;
 
        backup_active = nexthop_list_active_update(
-               rn, re, zebra_nhg_get_backup_nhg(curr_nhe)->nexthop);
+               rn, re, zebra_nhg_get_backup_nhg(curr_nhe));
 
        if (IS_ZEBRA_DEBUG_NHG_DETAIL)
                zlog_debug("%s: re %p backup_active %u", __func__, re,