pimd: remove peerlink_rif from the orig-mroute OIL when it is oper down

In an anycast VTEP setup the peerlink_rif is added as a static OIF
to the originating mroute (bypassing the pim state machine). This is
needed to ensure both MLAG switches rx a copy of encapsulated BUM flow.

We were not handling link state changes on this static OIF resulting
in the wrong vifi being used in the OIL (because of vifi re-allocation).
This commit re-acts to oper state changes by deleting the OIF on link
down and re-adding it on link up.

Signed-off-by: Anuradha Karuppiah <anuradhak@cumulusnetworks.com>

1 files changed, 34 insertions, 23 deletions

diff --git a/pimd/pim_vxlan.c b/pimd/pim_vxlan.c
index 41a57c267..bd6998c4b 100644
--- a/pimd/pim_vxlan.c
+++ b/pimd/pim_vxlan.c
@@ -788,7 +788,8 @@ bool pim_vxlan_do_mlag_reg(void)
  * to the MLAG peer which may mroute it over the underlay if there are any
  * interested receivers.
  */
-static void pim_vxlan_sg_peerlink_update(struct hash_backet *backet, void *arg)
+static void pim_vxlan_sg_peerlink_oif_update(struct hash_backet *backet,
+		void *arg)
 {
 	struct interface *new_oif = (struct interface *)arg;
 	struct pim_vxlan_sg *vxlan_sg = (struct pim_vxlan_sg *)backet->data;
@@ -827,8 +828,6 @@ void pim_vxlan_mlag_update(bool enable, bool peer_state, uint32_t role,
 				struct in_addr *reg_addr)
 {
 	struct pim_instance *pim;
-	struct interface *old_oif;
-	struct interface *new_oif;
 	char addr_buf[INET_ADDRSTRLEN];
 	struct pim_interface *pim_ifp = NULL;
 
@@ -848,8 +847,6 @@ void pim_vxlan_mlag_update(bool enable, bool peer_state, uint32_t role,
 	 */
 	pim = pim_get_pim_instance(VRF_DEFAULT);
 
-	old_oif = pim_vxlan_orig_mr_oif_get(pim);
-
 	if (enable)
 		vxlan_mlag.flags |= PIM_VXLAN_MLAGF_ENABLED;
 	else
@@ -870,11 +867,6 @@ void pim_vxlan_mlag_update(bool enable, bool peer_state, uint32_t role,
 		pim_vxlan_set_peerlink_rif(pim, peerlink_rif);
 	else
 		pim_vxlan_set_peerlink_rif(pim, NULL);
-
-	new_oif = pim_vxlan_orig_mr_oif_get(pim);
-	if (old_oif != new_oif)
-		hash_iterate(pim->vxlan.sg_hash, pim_vxlan_sg_peerlink_update,
-			new_oif);
 }
 
 /****************************** misc callbacks *******************************/
@@ -972,6 +964,9 @@ static void pim_vxlan_set_peerlink_rif(struct pim_instance *pim,
 			struct interface *ifp)
 {
 	struct interface *old_iif;
+	struct interface *new_iif;
+	struct interface *old_oif;
+	struct interface *new_oif;
 
 	if (pim->vxlan.peerlink_rif == ifp)
 		return;
@@ -983,22 +978,38 @@ static void pim_vxlan_set_peerlink_rif(struct pim_instance *pim,
 			ifp ? ifp->name : "-");
 
 	old_iif = pim_vxlan_orig_mr_iif_get(pim);
+	old_oif = pim_vxlan_orig_mr_oif_get(pim);
 	pim->vxlan.peerlink_rif = ifp;
-	ifp = pim_vxlan_orig_mr_iif_get(pim);
-	if (old_iif == ifp)
-		return;
 
-	if (PIM_DEBUG_VXLAN)
-		zlog_debug("%s: vxlan orig iif changed from %s to %s",
-			__PRETTY_FUNCTION__, old_iif ? old_iif->name : "-",
-			ifp ? ifp->name : "-");
+	new_iif = pim_vxlan_orig_mr_iif_get(pim);
+	if (old_iif != new_iif) {
+		if (PIM_DEBUG_VXLAN)
+			zlog_debug("%s: vxlan orig iif changed from %s to %s",
+				__PRETTY_FUNCTION__,
+				old_iif ? old_iif->name : "-",
+				new_iif ? new_iif->name : "-");
 
-	/* add/del upstream entries for the existing vxlan SG when the
-	 * interface becomes available
-	 */
-	if (pim->vxlan.sg_hash)
-		hash_iterate(pim->vxlan.sg_hash,
-				pim_vxlan_sg_peerlink_rif_update, old_iif);
+		/* add/del upstream entries for the existing vxlan SG when the
+		 * interface becomes available
+		 */
+		if (pim->vxlan.sg_hash)
+			hash_iterate(pim->vxlan.sg_hash,
+					pim_vxlan_sg_peerlink_rif_update,
+					old_iif);
+	}
+
+	new_oif = pim_vxlan_orig_mr_oif_get(pim);
+	if (old_oif != new_oif) {
+		if (PIM_DEBUG_VXLAN)
+			zlog_debug("%s: vxlan orig oif changed from %s to %s",
+				__PRETTY_FUNCTION__,
+				old_oif ? old_oif->name : "-",
+				new_oif ? new_oif->name : "-");
+		if (pim->vxlan.sg_hash)
+			hash_iterate(pim->vxlan.sg_hash,
+					pim_vxlan_sg_peerlink_oif_update,
+					new_oif);
+	}
 }
 
 void pim_vxlan_add_vif(struct interface *ifp)