From 5bc4a46b007b14a4b3729f11d0160402b8e89429 Mon Sep 17 00:00:00 2001 From: Mobashshera Rasool Date: Sun, 6 Feb 2022 23:23:21 -0800 Subject: [PATCH] pimd: Querier to non-querier transistion to be ignored in a case As per RFC 2236 section 3, when the leave message is received at a querier, it starts sending Query messages for "last Member Query Interval*query count" During this time there should not be any querier to non-querier transition and the same router needs to send the remaning queries. Fixes: #10422 Signed-off-by: Mobashshera Rasool --- pimd/pim_igmp.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/pimd/pim_igmp.c b/pimd/pim_igmp.c index cf7613f4e4..512384d642 100644 --- a/pimd/pim_igmp.c +++ b/pimd/pim_igmp.c @@ -377,6 +377,30 @@ static int igmp_recv_query(struct gm_sock *igmp, int query_version, */ if (ntohl(from.s_addr) < ntohl(igmp->ifaddr.s_addr)) { + /* As per RFC 2236 section 3: + * When a Querier receives a Leave Group message for a group + * that has group members on the reception interface, it sends + * [Last Member Query Count] Group-Specific Queries every [Last + * Member Query Interval] to the group being left. These + * Group-Specific Queries have their Max Response time set to + * [Last Member Query Interval]. If no Reports are received + * after the response time of the last query expires, the + * routers assume that the group has no local members, as above. + * Any Querier to non-Querier transition is ignored during this + * time; the same router keeps sending the Group-Specific + * Queries. + */ + struct gm_group *group; + + group = find_group_by_addr(igmp, group_addr); + if (group && group->t_group_query_retransmit_timer) { + if (PIM_DEBUG_IGMP_TRACE) + zlog_debug( + "%s: lower address query packet from %s is ignored when last member query interval timer is running", + ifp->name, from_str); + return 0; + } + if (PIM_DEBUG_IGMP_TRACE) { char ifaddr_str[INET_ADDRSTRLEN]; pim_inet4_dump("", igmp->ifaddr, ifaddr_str,