From 312c97ae18ef6260e8ccbc932a1fd1fc88cbd6fb Mon Sep 17 00:00:00 2001 From: Sarita Patra Date: Sun, 9 Apr 2023 22:30:44 -0700 Subject: [PATCH] pimd: Process no-forward BSM packet Topology Used: ============= Cisco---FRR4----FRR2 Initially PIM nbr is down between FRR4----FRR2 from FRR2 side Cisco is sending BSR packet to FRR4. Problem Statement: ================= No shutdown the PIM neighbor on FRR2 towards FRR4. FRR2, receives BSR packet immediately as the new neighbor comes up. This BSR packet is having no-forward bit set. FRR2 is not able to process the BSR packet, and drop the BSR packet. Root Cause: ========== When PIMD comes up, we start BSM timer for 60 seconds. Here, the value accept_nofwd_bsm is setting to false. FRR2, when receives no-forward BSR packet, it is getting accept_nofwd_bsm value as false. So, it drops, the no-forward BSM packet. Fix: === Set accept_nofwd_bsm as false after first BSM packet received. Signed-off-by: Sarita Patra (cherry picked from commit 8b462d557905200d98c7a8965b3d223637c3c5dd) --- pimd/pim_bsm.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/pimd/pim_bsm.c b/pimd/pim_bsm.c index 1f7dd2f3f9..9942886b77 100644 --- a/pimd/pim_bsm.c +++ b/pimd/pim_bsm.c @@ -170,7 +170,6 @@ static void pim_on_bs_timer(struct thread *t) pim_nht_bsr_del(scope->pim, scope->current_bsr); /* Reset scope zone data */ - scope->accept_nofwd_bsm = false; scope->state = ACCEPT_ANY; scope->current_bsr = PIMADDR_ANY; scope->current_bsr_prio = 0; @@ -1378,6 +1377,10 @@ int pim_bsm_process(struct interface *ifp, pim_sgaddr *sg, uint8_t *buf, } } + /* BSM packet is seen, so resetting accept_nofwd_bsm to false */ + if (pim->global_scope.accept_nofwd_bsm) + pim->global_scope.accept_nofwd_bsm = false; + if (!pim_addr_cmp(sg->grp, qpim_all_pim_routers_addr)) { /* Multicast BSMs are only accepted if source interface & IP * match RPF towards the BSR's IP address, or they have -- 2.39.5