From 4a96ff2af91087ea0ebc3523193d883d9e5c0409 Mon Sep 17 00:00:00 2001 From: Donald Sharp Date: Mon, 17 Jul 2023 10:00:32 -0400 Subject: [PATCH] zebra: Further handle route replace semantics When an upper level protocol is installing a route X that needs to be route replaced and at the same time the same or another protocol installs a different route that depends on route X for nexthop resolution can leave us with a state where the route is not accepted because zebra is still really early in the route replace semantics ( route X is still on the work Queue to be processed ) then the dependent route would not be installed. This came up in the bgp_default_originate test cases frequently. Further extendd the ROUTE_ENTR_ROUTE_REPLACING flag to cover this case as well. This has come up because the early route processing queueing that was implemented late last year. Signed-off-by: Donald Sharp (cherry picked from commit af80201876db00f339e2fbb9036942629aad9e67) --- zebra/zebra_nhg.c | 16 ++++++++-------- zebra/zebra_rib.c | 7 ++++++- 2 files changed, 14 insertions(+), 9 deletions(-) diff --git a/zebra/zebra_nhg.c b/zebra/zebra_nhg.c index 758fed7280..58fa245eba 100644 --- a/zebra/zebra_nhg.c +++ b/zebra/zebra_nhg.c @@ -2333,17 +2333,18 @@ static int nexthop_active(struct nexthop *nexthop, struct nhg_hash_entry *nhe, if (is_default_prefix(&rn->p) && !rnh_resolve_via_default(zvrf, p.family)) { if (IS_ZEBRA_DEBUG_RIB_DETAILED) - zlog_debug( - " :%s: Resolved against default route", - __func__); + zlog_debug(" :%s: %pFX Resolved against default route", + __func__, &p); return 0; } dest = rib_dest_from_rnode(rn); - if (dest && dest->selected_fib - && !CHECK_FLAG(dest->selected_fib->status, - ROUTE_ENTRY_REMOVED) - && dest->selected_fib->type != ZEBRA_ROUTE_TABLE) + if (dest && dest->selected_fib && + (!CHECK_FLAG(dest->selected_fib->status, + ROUTE_ENTRY_REMOVED) || + CHECK_FLAG(dest->selected_fib->status, + ROUTE_ENTRY_ROUTE_REPLACING)) && + dest->selected_fib->type != ZEBRA_ROUTE_TABLE) match = dest->selected_fib; /* If there is no selected route or matched route is EGP, go up @@ -2355,7 +2356,6 @@ static int nexthop_active(struct nexthop *nexthop, struct nhg_hash_entry *nhe, } while (rn && rn->info == NULL); if (rn) route_lock_node(rn); - continue; } diff --git a/zebra/zebra_rib.c b/zebra/zebra_rib.c index b0faa422c3..3a2545dac9 100644 --- a/zebra/zebra_rib.c +++ b/zebra/zebra_rib.c @@ -2800,8 +2800,13 @@ static void process_subq_early_route_add(struct zebra_early_route *ere) rib_addnode(rn, re, 1); /* Free implicit route.*/ - if (same) + if (same) { + rib_dest_t *dest = rn->info; + + if (same == dest->selected_fib) + SET_FLAG(same->status, ROUTE_ENTRY_ROUTE_REPLACING); rib_delnode(rn, same); + } /* See if we can remove some RE entries that are queued for * removal, but won't be considered in rib processing. -- 2.39.5