From 2f3b48fe647535b911c4c493ad8dd1cdfe6aa2cf Mon Sep 17 00:00:00 2001 From: Sudharsan Dhamal Gopalarathnam Date: Wed, 22 Nov 2023 23:01:13 -0800 Subject: [PATCH] [FRR] Fixing zebra to handle non notification of better admin won (#17184) * [FRR]Fixing zebra to handle non notification of better admin won * Updating the patch with latest changes from FRR --- ...non-notification-of-better-admin-won.patch | 70 +++++++++++++++++++ src/sonic-frr/patch/series | 1 + 2 files changed, 71 insertions(+) create mode 100644 src/sonic-frr/patch/0027-zebra-Fix-non-notification-of-better-admin-won.patch diff --git a/src/sonic-frr/patch/0027-zebra-Fix-non-notification-of-better-admin-won.patch b/src/sonic-frr/patch/0027-zebra-Fix-non-notification-of-better-admin-won.patch new file mode 100644 index 0000000000..a1e06a7f5f --- /dev/null +++ b/src/sonic-frr/patch/0027-zebra-Fix-non-notification-of-better-admin-won.patch @@ -0,0 +1,70 @@ +From 41b759505afb261211f40e386a30f6cf3870a094 Mon Sep 17 00:00:00 2001 +From: dgsudharsan +Date: Tue, 21 Nov 2023 17:55:24 +0000 +Subject: [PATCH] zebra: Fix non-notification of better admin won If there + happens to be a entry in the zebra rib that has a lower admin distance then a + newly received re, zebra would not notify the upper level protocol about this + happening. Imagine a case where there is a connected route for say a /32 and + bgp receives a route from a peer that is the same route as the connected. + Since BGP has no network statement and perceives the route as being `good` + bgp will install the route into zebra. Zebra will look at the new bgp re and + correctly identify that the re is not something that it will use and do + nothing. This change notices this and sends up a BETTER_ADMIN_WON route + notification. + + +diff --git a/zebra/zebra_rib.c b/zebra/zebra_rib.c +index 039c44cc09..f2f20bcf7b 100644 +--- a/zebra/zebra_rib.c ++++ b/zebra/zebra_rib.c +@@ -1209,6 +1209,7 @@ static void rib_process(struct route_node *rn) + rib_dest_t *dest; + struct zebra_vrf *zvrf = NULL; + struct vrf *vrf; ++ struct route_entry *proto_re_changed = NULL; + + vrf_id_t vrf_id = VRF_UNKNOWN; + +@@ -1278,6 +1279,7 @@ static void rib_process(struct route_node *rn) + * skip it. + */ + if (CHECK_FLAG(re->status, ROUTE_ENTRY_CHANGED)) { ++ proto_re_changed = re; + if (!nexthop_active_update(rn, re)) { + const struct prefix *p; + struct rib_table_info *info; +@@ -1363,6 +1365,8 @@ static void rib_process(struct route_node *rn) + * new_selected --- RE entry that is newly SELECTED + * old_fib --- RE entry currently in kernel FIB + * new_fib --- RE entry that is newly to be in kernel FIB ++ * proto_re_changed -- RE that is the last changed entry in the ++ * list of RE's. + * + * new_selected will get SELECTED flag, and is going to be redistributed + * the zclients. new_fib (which can be new_selected) will be installed +@@ -1417,6 +1421,22 @@ static void rib_process(struct route_node *rn) + } + } + ++ /* ++ * If zebra has a new_selected and a proto_re_changed ++ * entry that was not the old selected and the protocol ++ * is different, zebra should notify the upper level ++ * protocol that the sent down entry was not selected ++ */ ++ if (new_selected && proto_re_changed && ++ proto_re_changed != old_selected && ++ new_selected->type != proto_re_changed->type) { ++ struct rib_table_info *info = srcdest_rnode_table_info(rn); ++ ++ zsend_route_notify_owner(rn, proto_re_changed, ++ ZAPI_ROUTE_BETTER_ADMIN_WON, info->afi, ++ info->safi); ++ } ++ + /* Update fib according to selection results */ + if (new_fib && old_fib) + rib_process_update_fib(zvrf, rn, old_fib, new_fib); +-- +2.17.1 + diff --git a/src/sonic-frr/patch/series b/src/sonic-frr/patch/series index d914370a70..c057585d64 100644 --- a/src/sonic-frr/patch/series +++ b/src/sonic-frr/patch/series @@ -26,3 +26,4 @@ cross-compile-changes.patch 0024-bgpd-Do-not-process-NLRIs-if-the-attribute-length-is.patch 0025-bgpd-Use-treat-as-withdraw-for-tunnel-encapsulation-.patch 0026-zebra-Add-encap-type-when-building-packet-for-FPM.patch +0027-zebra-Fix-non-notification-of-better-admin-won.patch