pimd: Use PIM EVPN MLAG Infra for syncing PIM MLAG Entries

Initially, MLAG Sync is happened at pim_ifchannel, this is mainly to
support even config mismatches(missing configuration of dual active).
But this causes more syncs for each entry.

and also it is not In-line with PIM EVPN. to avoid that moving to
pm_upstream based syncing.

Signed-off-by: Satheesh Kumar K <sathk@cumulusnetworks.com>

6 files changed, 158 insertions, 10 deletions

diff --git a/pimd/pim_iface.h b/pimd/pim_iface.h
index 1b76b52305..570bf5eac3 100644
--- a/pimd/pim_iface.h
+++ b/pimd/pim_iface.h
@@ -55,6 +55,7 @@
 #define PIM_IF_DONT_PIM_CAN_DISABLE_JOIN_SUPRESSION(options) ((options) &= ~PIM_IF_MASK_PIM_CAN_DISABLE_JOIN_SUPRESSION)
 
 #define PIM_I_am_DR(pim_ifp) (pim_ifp)->pim_dr_addr.s_addr == (pim_ifp)->primary_address.s_addr
+#define PIM_I_am_DualActive(pim_ifp) (pim_ifp)->activeactive == true
 
 struct pim_iface_upstream_switch {
 	struct in_addr address;
diff --git a/pimd/pim_ifchannel.c b/pimd/pim_ifchannel.c
index 528c93ce16..e23d3dc3da 100644
--- a/pimd/pim_ifchannel.c
+++ b/pimd/pim_ifchannel.c
@@ -43,6 +43,7 @@
 #include "pim_upstream.h"
 #include "pim_ssm.h"
 #include "pim_rp.h"
+#include "pim_mlag.h"
 
 RB_GENERATE(pim_ifchannel_rb, pim_ifchannel, pim_ifp_rb, pim_ifchannel_compare);
 
@@ -130,6 +131,21 @@ void pim_ifchannel_delete(struct pim_ifchannel *ch)
 
 	pim_ifp = ch->interface->info;
 
+	if (PIM_I_am_DualActive(pim_ifp)) {
+		if (PIM_DEBUG_MLAG)
+			zlog_debug(
+				"%s: if-chnanel-%s is deleted from a Dual "
+				"active Interface",
+				__func__, ch->sg_str);
+		/* Post Delete only if it is the last Dual-active Interface */
+		if (ch->upstream->dualactive_ifchannel_count == 1) {
+			pim_mlag_up_local_del(pim_ifp->pim, ch->upstream);
+			PIM_UPSTREAM_FLAG_UNSET_MLAG_INTERFACE(
+				ch->upstream->flags);
+		}
+		ch->upstream->dualactive_ifchannel_count--;
+	}
+
 	if (ch->upstream->channel_oil) {
 		uint32_t mask = PIM_OIF_FLAG_PROTO_PIM;
 		if (ch->upstream->flags & PIM_UPSTREAM_FLAG_MASK_SRC_IGMP)
@@ -586,6 +602,24 @@ struct pim_ifchannel *pim_ifchannel_add(struct interface *ifp,
 	else
 		PIM_IF_FLAG_UNSET_ASSERT_TRACKING_DESIRED(ch->flags);
 
+	/*
+	 * advertise MLAG Data to MLAG peer
+	 */
+	if (PIM_I_am_DualActive(pim_ifp)) {
+		up->dualactive_ifchannel_count++;
+		/* Sync once for upstream */
+		if (up->dualactive_ifchannel_count == 1) {
+			PIM_UPSTREAM_FLAG_SET_MLAG_INTERFACE(up->flags);
+			pim_mlag_up_local_add(pim_ifp->pim, up);
+		}
+		if (PIM_DEBUG_MLAG)
+			zlog_debug(
+				"%s: New Dual active if-chnanel is added to upstream:%s "
+				"count:%d, flags:0x%x",
+				__func__, up->sg_str,
+				up->dualactive_ifchannel_count, up->flags);
+	}
+
 	if (PIM_DEBUG_PIM_TRACE)
 		zlog_debug("%s: ifchannel %s is created ", __func__,
 			   ch->sg_str);
diff --git a/pimd/pim_mlag.c b/pimd/pim_mlag.c
index defe41674c..321745590d 100644
--- a/pimd/pim_mlag.c
+++ b/pimd/pim_mlag.c
@@ -32,6 +32,76 @@ extern struct zclient *zclient;
 
 #define PIM_MLAG_METADATA_LEN 4
 
+/*********************ACtual Data processing *****************************/
+/* TBD: There can be duplicate updates to FIB***/
+#define PIM_MLAG_ADD_OIF_TO_OIL(ch, ch_oil)                                    \
+	do {                                                                   \
+		if (PIM_DEBUG_MLAG)                                            \
+			zlog_debug(                                            \
+				"%s: add Dual-active Interface to %s "         \
+				"to oil:%s",                                   \
+				__func__, ch->interface->name, ch->sg_str);    \
+		pim_channel_add_oif(ch_oil, ch->interface,                     \
+				    PIM_OIF_FLAG_PROTO_IGMP, __func__);        \
+	} while (0)
+
+#define PIM_MLAG_DEL_OIF_TO_OIL(ch, ch_oil)                                    \
+	do {                                                                   \
+		if (PIM_DEBUG_MLAG)                                            \
+			zlog_debug(                                            \
+				"%s: del Dual-active Interface to %s "         \
+				"to oil:%s",                                   \
+				__func__, ch->interface->name, ch->sg_str);    \
+		pim_channel_del_oif(ch_oil, ch->interface,                     \
+				    PIM_OIF_FLAG_PROTO_IGMP, __func__);        \
+	} while (0)
+
+
+static void pim_mlag_calculate_df_for_ifchannels(struct pim_upstream *up,
+						 bool is_df)
+{
+	struct listnode *chnode;
+	struct listnode *chnextnode;
+	struct pim_ifchannel *ch;
+	struct pim_interface *pim_ifp = NULL;
+	struct channel_oil *ch_oil = NULL;
+
+	ch_oil = (up) ? up->channel_oil : NULL;
+
+	if (!ch_oil)
+		return;
+
+	if (PIM_DEBUG_MLAG)
+		zlog_debug("%s: Calculating DF for Dual active if-channel%s",
+			   __func__, up->sg_str);
+
+	for (ALL_LIST_ELEMENTS(up->ifchannels, chnode, chnextnode, ch)) {
+		pim_ifp = (ch->interface) ? ch->interface->info : NULL;
+		if (!pim_ifp || !PIM_I_am_DualActive(pim_ifp))
+			continue;
+
+		if (is_df)
+			PIM_MLAG_ADD_OIF_TO_OIL(ch, ch_oil);
+		else
+			PIM_MLAG_DEL_OIF_TO_OIL(ch, ch_oil);
+	}
+}
+
+static void pim_mlag_inherit_mlag_flags(struct pim_upstream *up, bool is_df)
+{
+	struct listnode *listnode;
+	struct pim_upstream *child;
+
+	for (ALL_LIST_ELEMENTS_RO(up->sources, listnode, child)) {
+		PIM_UPSTREAM_FLAG_SET_MLAG_PEER(child->flags);
+		if (is_df)
+			PIM_UPSTREAM_FLAG_UNSET_MLAG_NON_DF(child->flags);
+		else
+			PIM_UPSTREAM_FLAG_SET_MLAG_NON_DF(child->flags);
+		pim_mlag_calculate_df_for_ifchannels(child, is_df);
+	}
+}
+
 /******************************* pim upstream sync **************************/
 /* Update DF role for the upstream entry and return true on role change */
 bool pim_mlag_up_df_role_update(struct pim_instance *pim,
@@ -59,6 +129,15 @@ bool pim_mlag_up_df_role_update(struct pim_instance *pim,
 		PIM_UPSTREAM_FLAG_SET_MLAG_NON_DF(up->flags);
 
 
+	/*
+	 * This Upstream entry synced to peer Because of Dual-active
+	 * Interface configuration
+	 */
+	if (PIM_UPSTREAM_FLAG_TEST_MLAG_INTERFACE(up->flags)) {
+		pim_mlag_calculate_df_for_ifchannels(up, is_df);
+		pim_mlag_inherit_mlag_flags(up, is_df);
+	}
+
 	/* If the DF role has changed check if ipmr-lo needs to be
 	 * muted/un-muted. Active-Active devices and vxlan termination
 	 * devices (ipmr-lo) are suppressed on the non-DF.
@@ -91,7 +170,8 @@ static bool pim_mlag_up_df_role_elect(struct pim_instance *pim,
 	uint32_t local_cost;
 	bool rv;
 
-	if (!pim_up_mlag_is_local(up))
+	if (!pim_up_mlag_is_local(up)
+	    && !PIM_UPSTREAM_FLAG_TEST_MLAG_INTERFACE(up->flags))
 		return false;
 
 	/* We are yet to rx a status update from the local MLAG daemon so
@@ -417,7 +497,8 @@ static void pim_mlag_up_local_replay(void)
 	RB_FOREACH(vrf, vrf_name_head, &vrfs_by_name) {
 		pim = vrf->info;
 		frr_each (rb_pim_upstream, &pim->upstream_head, up) {
-			if (pim_up_mlag_is_local(up))
+			if (pim_up_mlag_is_local(up)
+			    || PIM_UPSTREAM_FLAG_TEST_MLAG_INTERFACE(up->flags))
 				pim_mlag_up_local_add_send(pim, up);
 		}
 	}
@@ -438,7 +519,9 @@ static void pim_mlag_up_local_reeval(bool mlagd_send, const char *reason_code)
 	RB_FOREACH(vrf, vrf_name_head, &vrfs_by_name) {
 		pim = vrf->info;
 		frr_each (rb_pim_upstream, &pim->upstream_head, up) {
-			if (!pim_up_mlag_is_local(up))
+			if (!pim_up_mlag_is_local(up)
+			    && !PIM_UPSTREAM_FLAG_TEST_MLAG_INTERFACE(
+				    up->flags))
 				continue;
 			/* if role changes re-send to peer */
 			if (pim_mlag_up_df_role_elect(pim, up) &&
@@ -772,6 +855,12 @@ int pim_zebra_mlag_process_up(void)
 	if (PIM_DEBUG_MLAG)
 		zlog_debug("%s: Received Process-Up from Mlag", __func__);
 
+	/*
+	 * Incase of local MLAG restart, PIM needs to replay all the data
+	 * since MLAG is empty.
+	 */
+	router->connected_to_mlag = true;
+	router->mlag_flags |= PIM_MLAGF_LOCAL_CONN_UP;
 	return 0;
 }
 
diff --git a/pimd/pim_mlag.h b/pimd/pim_mlag.h
index 4639f56826..eb316695f7 100644
--- a/pimd/pim_mlag.h
+++ b/pimd/pim_mlag.h
@@ -32,8 +32,6 @@ extern void pim_instance_mlag_init(struct pim_instance *pim);
 extern void pim_instance_mlag_terminate(struct pim_instance *pim);
 extern void pim_if_configure_mlag_dualactive(struct pim_interface *pim_ifp);
 extern void pim_if_unconfigure_mlag_dualactive(struct pim_interface *pim_ifp);
-extern void pim_mlag_register(void);
-extern void pim_mlag_deregister(void);
 extern int pim_zebra_mlag_process_up(void);
 extern int pim_zebra_mlag_process_down(void);
 extern int pim_zebra_mlag_handle_msg(struct stream *msg, int len);
@@ -43,10 +41,13 @@ extern int pim_mlag_signal_zpthread(void);
 extern void pim_zpthread_init(void);
 extern void pim_zpthread_terminate(void);
 
+extern void pim_mlag_register(void);
+extern void pim_mlag_deregister(void);
 extern void pim_mlag_up_local_add(struct pim_instance *pim,
-		struct pim_upstream *upstream);
+				  struct pim_upstream *upstream);
 extern void pim_mlag_up_local_del(struct pim_instance *pim,
-		struct pim_upstream *upstream);
+				  struct pim_upstream *upstream);
 extern bool pim_mlag_up_df_role_update(struct pim_instance *pim,
-		struct pim_upstream *up, bool is_df, const char *reason);
+				       struct pim_upstream *up, bool is_df,
+				       const char *reason);
 #endif
diff --git a/pimd/pim_upstream.c b/pimd/pim_upstream.c
index c905dd146a..998720e8f6 100644
--- a/pimd/pim_upstream.c
+++ b/pimd/pim_upstream.c
@@ -141,6 +141,18 @@ static struct pim_upstream *pim_upstream_find_parent(struct pim_instance *pim,
 		if (up)
 			listnode_add(up->sources, child);
 
+		/*
+		 * In case parent is MLAG entry copy the data to child
+		 */
+		if (up && PIM_UPSTREAM_FLAG_TEST_MLAG_INTERFACE(up->flags)) {
+			PIM_UPSTREAM_FLAG_SET_MLAG_INTERFACE(child->flags);
+			if (PIM_UPSTREAM_FLAG_TEST_MLAG_NON_DF(up->flags))
+				PIM_UPSTREAM_FLAG_SET_MLAG_NON_DF(child->flags);
+			else
+				PIM_UPSTREAM_FLAG_UNSET_MLAG_NON_DF(
+					child->flags);
+		}
+
 		return up;
 	}
 
@@ -903,7 +915,8 @@ static struct pim_upstream *pim_upstream_new(struct pim_instance *pim,
 	/* XXX - duplicate send is possible here if pim_rpf_update
 	 * successfully resolved the nexthop
 	 */
-	if (pim_up_mlag_is_local(up))
+	if (pim_up_mlag_is_local(up)
+	    || PIM_UPSTREAM_FLAG_TEST_MLAG_INTERFACE(up->flags))
 		pim_mlag_up_local_add(pim, up);
 
 	if (PIM_DEBUG_PIM_TRACE) {
@@ -918,7 +931,8 @@ static struct pim_upstream *pim_upstream_new(struct pim_instance *pim,
 
 uint32_t pim_up_mlag_local_cost(struct pim_upstream *up)
 {
-	if (!(pim_up_mlag_is_local(up)))
+	if (!(pim_up_mlag_is_local(up))
+	    && !(up->flags & PIM_UPSTREAM_FLAG_MASK_MLAG_INTERFACE))
 		return router->infinite_assert_metric.route_metric;
 
 	if ((up->rpf.source_nexthop.interface ==
@@ -1752,6 +1766,7 @@ int pim_upstream_inherited_olist_decide(struct pim_instance *pim,
 				   up->sg_str);
 
 	FOR_ALL_INTERFACES (pim->vrf, ifp) {
+		struct pim_interface *pim_ifp;
 		if (!ifp->info)
 			continue;
 
@@ -1765,6 +1780,12 @@ int pim_upstream_inherited_olist_decide(struct pim_instance *pim,
 		if (!ch && !starch)
 			continue;
 
+		pim_ifp = ifp->info;
+		if (PIM_I_am_DualActive(pim_ifp)
+		    && PIM_UPSTREAM_FLAG_TEST_MLAG_INTERFACE(up->flags)
+		    && (PIM_UPSTREAM_FLAG_TEST_MLAG_NON_DF(up->flags)
+			|| !PIM_UPSTREAM_FLAG_TEST_MLAG_PEER(up->flags)))
+			continue;
 		if (pim_upstream_evaluate_join_desired_interface(up, ch,
 								 starch)) {
 			int flag = PIM_OIF_FLAG_PROTO_PIM;
diff --git a/pimd/pim_upstream.h b/pimd/pim_upstream.h
index 4d693b8b64..ca693ee73f 100644
--- a/pimd/pim_upstream.h
+++ b/pimd/pim_upstream.h
@@ -237,6 +237,8 @@ struct pim_upstream {
 	struct channel_oil *channel_oil;
 	struct list *sources;
 	struct list *ifchannels;
+	/* Counter for Dual active ifchannels*/
+	uint32_t dualactive_ifchannel_count;
 
 	enum pim_upstream_state join_state;
 	enum pim_reg_state reg_state;