From: Sai Gomathi <nsaigomathi@vmware.com>
Date: Tue, 26 Oct 2021 12:55:23 +0000 (-0700)
Subject: pimd: modifications in PIM joins
X-Git-Tag: base_8.2~258^2~1
X-Git-Url: https://git.puffer.fish/?a=commitdiff_plain;h=34abbcc4b16438c076262e9b4571e5a27efd540b;p=matthieu%2Ffrr.git

pimd: modifications in PIM joins

Problem :
=======
(*,G) created on transit node where same groups are defined as SSM
At present FRR has SSM checks for IGMP report, but SSM check is missing for PIM join.

Fix :
===
When an interface receives the PIM (*,G)join with G as SSM group, then PIMd supposed to discard that join.
There is no need to maintain PIM state for this group.

Signed-off-by: Sai Gomathi <nsaigomathi@vmware.com>
---

diff --git a/pimd/pim_join.c b/pimd/pim_join.c
index c7a80ca8e0..652b27476d 100644
--- a/pimd/pim_join.c
+++ b/pimd/pim_join.c
@@ -39,6 +39,7 @@
 #include "pim_rp.h"
 #include "pim_jp_agg.h"
 #include "pim_util.h"
+#include "pim_ssm.h"
 
 static void on_trace(const char *label, struct interface *ifp,
 		     struct in_addr src)
@@ -55,6 +56,7 @@ static void recv_join(struct interface *ifp, struct pim_neighbor *neigh,
 		      struct prefix_sg *sg, uint8_t source_flags)
 {
 	struct pim_interface *pim_ifp = NULL;
+	char buf[PREFIX_STRLEN];
 
 	if (PIM_DEBUG_PIM_TRACE) {
 		char up_str[INET_ADDRSTRLEN];
@@ -105,6 +107,14 @@ static void recv_join(struct interface *ifp, struct pim_neighbor *neigh,
 			return;
 		}
 
+		if (pim_is_grp_ssm(pim_ifp->pim, sg->grp)) {
+			zlog_warn(
+				"%s: Specified Group(%s) in join is now in SSM, not allowed to create PIM state",
+				__func__,
+				inet_ntop(AF_INET, &sg->grp, buf, sizeof(buf)));
+			return;
+		}
+
 		sg->src.s_addr = INADDR_ANY;
 	}
 
diff --git a/pimd/pim_register.c b/pimd/pim_register.c
index 9d5b864ab0..fc464753e0 100644
--- a/pimd/pim_register.c
+++ b/pimd/pim_register.c
@@ -323,6 +323,7 @@ int pim_register_recv(struct interface *ifp, struct in_addr dest_addr,
 	int i_am_rp = 0;
 	struct pim_interface *pim_ifp = ifp->info;
 	struct pim_instance *pim = pim_ifp->pim;
+	char buf[PREFIX_STRLEN];
 
 #define PIM_MSG_REGISTER_BIT_RESERVED_LEN 4
 	ip_hdr = (struct ip *)(tlv_buf + PIM_MSG_REGISTER_BIT_RESERVED_LEN);
@@ -381,6 +382,17 @@ int pim_register_recv(struct interface *ifp, struct in_addr dest_addr,
 			   pim_str_sg_dump(&sg), src_str, ifp->name, i_am_rp);
 	}
 
+	if (pim_is_grp_ssm(pim_ifp->pim, sg.grp)) {
+		if (sg.src.s_addr == INADDR_ANY) {
+			zlog_warn(
+				"%s: Received Register message for Group(%s) is now in SSM, dropping the packet",
+				__func__,
+				inet_ntop(AF_INET, &sg.grp, buf, sizeof(buf)));
+			/* Drop Packet Silently */
+			return 0;
+		}
+	}
+
 	if (i_am_rp
 	    && (dest_addr.s_addr
 		== ((RP(pim, sg.grp))->rpf_addr.u.prefix4.s_addr))) {