Adding upstream version 9.1.upstream/9.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1453 insertions, 0 deletions

diff --git a/pimd/pim_bsm.c b/pimd/pim_bsm.c
new file mode 100644
index 0000000..df91619
--- /dev/null
+++ b/pimd/pim_bsm.c
@@ -0,0 +1,1453 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * pim_bsm.c: PIM BSM handling routines
+ *
+ * Copyright (C) 2018-19 Vmware, Inc.
+ * Saravanan K
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "if.h"
+#include "pimd.h"
+#include "pim_iface.h"
+#include "pim_instance.h"
+#include "pim_neighbor.h"
+#include "pim_rpf.h"
+#include "pim_hello.h"
+#include "pim_pim.h"
+#include "pim_nht.h"
+#include "pim_bsm.h"
+#include "pim_time.h"
+#include "pim_zebra.h"
+#include "pim_util.h"
+
+/* Functions forward declaration */
+static void pim_bs_timer_start(struct bsm_scope *scope, int bs_timeout);
+static void pim_g2rp_timer_start(struct bsm_rpinfo *bsrp, int hold_time);
+static inline void pim_g2rp_timer_restart(struct bsm_rpinfo *bsrp,
+					  int hold_time);
+
+/* Memory Types */
+DEFINE_MTYPE_STATIC(PIMD, PIM_BSGRP_NODE, "PIM BSR advertised grp info");
+DEFINE_MTYPE_STATIC(PIMD, PIM_BSRP_INFO, "PIM BSR advertised RP info");
+DEFINE_MTYPE_STATIC(PIMD, PIM_BSM_FRAG, "PIM BSM fragment");
+DEFINE_MTYPE_STATIC(PIMD, PIM_BSM_PKT_VAR_MEM, "PIM BSM Packet");
+
+/* All bsm packets forwarded shall be fit within ip mtu less iphdr(max) */
+#define MAX_IP_HDR_LEN 24
+
+/* pim_bsm_write_config - Write the interface pim bsm configuration.*/
+void pim_bsm_write_config(struct vty *vty, struct interface *ifp)
+{
+	struct pim_interface *pim_ifp = ifp->info;
+
+	if (pim_ifp) {
+		if (!pim_ifp->bsm_enable)
+			vty_out(vty, " no " PIM_AF_NAME " pim bsm\n");
+		if (!pim_ifp->ucast_bsm_accept)
+			vty_out(vty, " no " PIM_AF_NAME " pim unicast-bsm\n");
+	}
+}
+
+static void pim_bsm_rpinfo_free(struct bsm_rpinfo *bsrp_info)
+{
+	EVENT_OFF(bsrp_info->g2rp_timer);
+	XFREE(MTYPE_PIM_BSRP_INFO, bsrp_info);
+}
+
+static void pim_bsm_rpinfos_free(struct bsm_rpinfos_head *head)
+{
+	struct bsm_rpinfo *bsrp_info;
+
+	while ((bsrp_info = bsm_rpinfos_pop(head)))
+		pim_bsm_rpinfo_free(bsrp_info);
+}
+
+static void pim_free_bsgrp_data(struct bsgrp_node *bsgrp_node)
+{
+	pim_bsm_rpinfos_free(bsgrp_node->bsrp_list);
+	pim_bsm_rpinfos_free(bsgrp_node->partial_bsrp_list);
+	XFREE(MTYPE_PIM_BSGRP_NODE, bsgrp_node);
+}
+
+static void pim_free_bsgrp_node(struct route_table *rt, struct prefix *grp)
+{
+	struct route_node *rn;
+
+	rn = route_node_lookup(rt, grp);
+	if (rn) {
+		rn->info = NULL;
+		route_unlock_node(rn);
+		route_unlock_node(rn);
+	}
+}
+
+static void pim_bsm_frag_free(struct bsm_frag *bsfrag)
+{
+	XFREE(MTYPE_PIM_BSM_FRAG, bsfrag);
+}
+
+static void pim_bsm_frags_free(struct bsm_scope *scope)
+{
+	struct bsm_frag *bsfrag;
+
+	while ((bsfrag = bsm_frags_pop(scope->bsm_frags)))
+		pim_bsm_frag_free(bsfrag);
+}
+
+int pim_bsm_rpinfo_cmp(const struct bsm_rpinfo *node1,
+		       const struct bsm_rpinfo *node2)
+{
+	/* RP election Algo :
+	 * Step-1 : Loweset Rp priority  will have higher precedance.
+	 * Step-2 : If priority same then higher hash val will have
+	 *	    higher precedance.
+	 * Step-3 : If Hash val is same then highest rp address will
+	 *	    become elected RP.
+	 */
+	if (node1->rp_prio < node2->rp_prio)
+		return -1;
+	if (node1->rp_prio > node2->rp_prio)
+		return 1;
+	if (node1->hash < node2->hash)
+		return 1;
+	if (node1->hash > node2->hash)
+		return -1;
+	return pim_addr_cmp(node2->rp_address, node1->rp_address);
+}
+
+static struct bsgrp_node *pim_bsm_new_bsgrp_node(struct route_table *rt,
+						 struct prefix *grp)
+{
+	struct route_node *rn;
+	struct bsgrp_node *bsgrp;
+
+	rn = route_node_get(rt, grp);
+	if (!rn) {
+		zlog_warn("%s: route node creation failed", __func__);
+		return NULL;
+	}
+	bsgrp = XCALLOC(MTYPE_PIM_BSGRP_NODE, sizeof(struct bsgrp_node));
+
+	rn->info = bsgrp;
+	bsm_rpinfos_init(bsgrp->bsrp_list);
+	bsm_rpinfos_init(bsgrp->partial_bsrp_list);
+
+	prefix_copy(&bsgrp->group, grp);
+	return bsgrp;
+}
+
+static void pim_on_bs_timer(struct event *t)
+{
+	struct route_node *rn;
+	struct bsm_scope *scope;
+	struct bsgrp_node *bsgrp_node;
+	struct bsm_rpinfo *bsrp;
+
+	scope = EVENT_ARG(t);
+	EVENT_OFF(scope->bs_timer);
+
+	if (PIM_DEBUG_BSM)
+		zlog_debug("%s: Bootstrap Timer expired for scope: %d",
+			   __func__, scope->sz_id);
+
+	pim_nht_bsr_del(scope->pim, scope->current_bsr);
+	/* Reset scope zone data */
+	scope->state = ACCEPT_ANY;
+	scope->current_bsr = PIMADDR_ANY;
+	scope->current_bsr_prio = 0;
+	scope->current_bsr_first_ts = 0;
+	scope->current_bsr_last_ts = 0;
+	scope->bsm_frag_tag = 0;
+	pim_bsm_frags_free(scope);
+
+	for (rn = route_top(scope->bsrp_table); rn; rn = route_next(rn)) {
+
+		bsgrp_node = (struct bsgrp_node *)rn->info;
+		if (!bsgrp_node) {
+			if (PIM_DEBUG_BSM)
+				zlog_debug("%s: bsgrp_node is null", __func__);
+			continue;
+		}
+		/* Give grace time for rp to continue for another hold time */
+		bsrp = bsm_rpinfos_first(bsgrp_node->bsrp_list);
+		if (bsrp)
+			pim_g2rp_timer_restart(bsrp, bsrp->rp_holdtime);
+
+		/* clear pending list */
+		pim_bsm_rpinfos_free(bsgrp_node->partial_bsrp_list);
+		bsgrp_node->pend_rp_cnt = 0;
+	}
+}
+
+static void pim_bs_timer_stop(struct bsm_scope *scope)
+{
+	if (PIM_DEBUG_BSM)
+		zlog_debug("%s : BS timer being stopped of sz: %d", __func__,
+			   scope->sz_id);
+	EVENT_OFF(scope->bs_timer);
+}
+
+static void pim_bs_timer_start(struct bsm_scope *scope, int bs_timeout)
+{
+	if (!scope) {
+		if (PIM_DEBUG_BSM)
+			zlog_debug("%s : Invalid scope(NULL).", __func__);
+		return;
+	}
+	EVENT_OFF(scope->bs_timer);
+	if (PIM_DEBUG_BSM)
+		zlog_debug(
+			"%s : starting bs timer for scope %d with timeout %d secs",
+			__func__, scope->sz_id, bs_timeout);
+	event_add_timer(router->master, pim_on_bs_timer, scope, bs_timeout,
+			&scope->bs_timer);
+}
+
+static inline void pim_bs_timer_restart(struct bsm_scope *scope, int bs_timeout)
+{
+	pim_bs_timer_start(scope, bs_timeout);
+}
+
+void pim_bsm_proc_init(struct pim_instance *pim)
+{
+	memset(&pim->global_scope, 0, sizeof(struct bsm_scope));
+
+	pim->global_scope.sz_id = PIM_GBL_SZ_ID;
+	pim->global_scope.bsrp_table = route_table_init();
+	pim->global_scope.accept_nofwd_bsm = true;
+	pim->global_scope.state = NO_INFO;
+	pim->global_scope.pim = pim;
+	bsm_frags_init(pim->global_scope.bsm_frags);
+	pim_bs_timer_start(&pim->global_scope, PIM_BS_TIME);
+}
+
+void pim_bsm_proc_free(struct pim_instance *pim)
+{
+	struct route_node *rn;
+	struct bsgrp_node *bsgrp;
+
+	pim_bs_timer_stop(&pim->global_scope);
+	pim_bsm_frags_free(&pim->global_scope);
+
+	for (rn = route_top(pim->global_scope.bsrp_table); rn;
+	     rn = route_next(rn)) {
+		bsgrp = rn->info;
+		if (!bsgrp)
+			continue;
+		pim_free_bsgrp_data(bsgrp);
+	}
+
+	route_table_finish(pim->global_scope.bsrp_table);
+}
+
+static bool is_hold_time_elapsed(void *data)
+{
+	struct bsm_rpinfo *bsrp;
+
+	bsrp = data;
+
+	if (bsrp->elapse_time < bsrp->rp_holdtime)
+		return false;
+	else
+		return true;
+}
+
+static void pim_on_g2rp_timer(struct event *t)
+{
+	struct bsm_rpinfo *bsrp;
+	struct bsm_rpinfo *bsrp_node;
+	struct bsgrp_node *bsgrp_node;
+	struct pim_instance *pim;
+	struct rp_info *rp_info;
+	struct route_node *rn;
+	uint16_t elapse;
+	pim_addr bsrp_addr;
+
+	bsrp = EVENT_ARG(t);
+	EVENT_OFF(bsrp->g2rp_timer);
+	bsgrp_node = bsrp->bsgrp_node;
+
+	/* elapse time is the hold time of expired node */
+	elapse = bsrp->rp_holdtime;
+	bsrp_addr = bsrp->rp_address;
+
+	/* update elapse for all bsrp nodes */
+	frr_each_safe (bsm_rpinfos, bsgrp_node->bsrp_list, bsrp_node) {
+		bsrp_node->elapse_time += elapse;
+
+		if (is_hold_time_elapsed(bsrp_node)) {
+			bsm_rpinfos_del(bsgrp_node->bsrp_list, bsrp_node);
+			pim_bsm_rpinfo_free(bsrp_node);
+		}
+	}
+
+	/* Get the next elected rp node */
+	bsrp = bsm_rpinfos_first(bsgrp_node->bsrp_list);
+	pim = bsgrp_node->scope->pim;
+	rn = route_node_lookup(pim->rp_table, &bsgrp_node->group);
+
+	if (!rn) {
+		zlog_warn("%s: Route node doesn't exist", __func__);
+		return;
+	}
+
+	rp_info = (struct rp_info *)rn->info;
+
+	if (!rp_info) {
+		route_unlock_node(rn);
+		return;
+	}
+
+	if (rp_info->rp_src != RP_SRC_STATIC) {
+		/* If new rp available, change it else delete the existing */
+		if (bsrp) {
+			pim_g2rp_timer_start(
+				bsrp, (bsrp->rp_holdtime - bsrp->elapse_time));
+			pim_rp_change(pim, bsrp->rp_address, bsgrp_node->group,
+				      RP_SRC_BSR);
+		} else {
+			pim_rp_del(pim, bsrp_addr, bsgrp_node->group, NULL,
+				   RP_SRC_BSR);
+		}
+	}
+
+	if (!bsm_rpinfos_count(bsgrp_node->bsrp_list)
+	    && !bsm_rpinfos_count(bsgrp_node->partial_bsrp_list)) {
+		pim_free_bsgrp_node(pim->global_scope.bsrp_table,
+				    &bsgrp_node->group);
+		pim_free_bsgrp_data(bsgrp_node);
+	}
+}
+
+static void pim_g2rp_timer_start(struct bsm_rpinfo *bsrp, int hold_time)
+{
+	if (!bsrp) {
+		if (PIM_DEBUG_BSM)
+			zlog_debug("%s : Invalid brsp(NULL).", __func__);
+		return;
+	}
+	EVENT_OFF(bsrp->g2rp_timer);
+	if (PIM_DEBUG_BSM)
+		zlog_debug(
+			"%s : starting g2rp timer for grp: %pFX - rp: %pPAs with timeout  %d secs(Actual Hold time : %d secs)",
+			__func__, &bsrp->bsgrp_node->group, &bsrp->rp_address,
+			hold_time, bsrp->rp_holdtime);
+
+	event_add_timer(router->master, pim_on_g2rp_timer, bsrp, hold_time,
+			&bsrp->g2rp_timer);
+}
+
+static inline void pim_g2rp_timer_restart(struct bsm_rpinfo *bsrp,
+					  int hold_time)
+{
+	pim_g2rp_timer_start(bsrp, hold_time);
+}
+
+static void pim_g2rp_timer_stop(struct bsm_rpinfo *bsrp)
+{
+	if (!bsrp)
+		return;
+
+	if (PIM_DEBUG_BSM)
+		zlog_debug("%s : stopping g2rp timer for grp: %pFX - rp: %pPAs",
+			   __func__, &bsrp->bsgrp_node->group,
+			   &bsrp->rp_address);
+
+	EVENT_OFF(bsrp->g2rp_timer);
+}
+
+static bool is_hold_time_zero(void *data)
+{
+	struct bsm_rpinfo *bsrp;
+
+	bsrp = data;
+
+	if (bsrp->rp_holdtime)
+		return false;
+	else
+		return true;
+}
+
+static void pim_instate_pend_list(struct bsgrp_node *bsgrp_node)
+{
+	struct bsm_rpinfo *active;
+	struct bsm_rpinfo *pend;
+	struct rp_info *rp_info;
+	struct route_node *rn;
+	struct pim_instance *pim;
+	struct rp_info *rp_all;
+	struct prefix group_all;
+	bool had_rp_node = true;
+
+	pim = bsgrp_node->scope->pim;
+	active = bsm_rpinfos_first(bsgrp_node->bsrp_list);
+
+	/* Remove nodes with hold time 0 & check if list still has a head */
+	frr_each_safe (bsm_rpinfos, bsgrp_node->partial_bsrp_list, pend) {
+		if (is_hold_time_zero(pend)) {
+			bsm_rpinfos_del(bsgrp_node->partial_bsrp_list, pend);
+			pim_bsm_rpinfo_free(pend);
+		}
+	}
+
+	pend = bsm_rpinfos_first(bsgrp_node->partial_bsrp_list);
+
+	if (!pim_get_all_mcast_group(&group_all))
+		return;
+
+	rp_all = pim_rp_find_match_group(pim, &group_all);
+	rn = route_node_lookup(pim->rp_table, &bsgrp_node->group);
+
+	if (pend)
+		pim_g2rp_timer_start(pend, pend->rp_holdtime);
+
+	/* if rp node doesn't exist or exist but not configured(rp_all),
+	 * install the rp from head(if exists) of partial list. List is
+	 * is sorted such that head is the elected RP for the group.
+	 */
+	if (!rn || (prefix_same(&rp_all->group, &bsgrp_node->group) &&
+		    pim_rpf_addr_is_inaddr_any(&rp_all->rp))) {
+		if (PIM_DEBUG_BSM)
+			zlog_debug("%s: Route node doesn't exist", __func__);
+		if (pend)
+			pim_rp_new(pim, pend->rp_address, bsgrp_node->group,
+				   NULL, RP_SRC_BSR);
+		had_rp_node = false;
+	} else {
+		rp_info = (struct rp_info *)rn->info;
+		if (!rp_info) {
+			route_unlock_node(rn);
+			if (pend)
+				pim_rp_new(pim, pend->rp_address,
+					   bsgrp_node->group, NULL, RP_SRC_BSR);
+			had_rp_node = false;
+		}
+	}
+
+	/* We didn't have rp node and pending list is empty(unlikely), cleanup*/
+	if ((!had_rp_node) && (!pend)) {
+		pim_free_bsgrp_node(bsgrp_node->scope->bsrp_table,
+				    &bsgrp_node->group);
+		pim_free_bsgrp_data(bsgrp_node);
+		return;
+	}
+
+	if ((had_rp_node) && (rp_info->rp_src != RP_SRC_STATIC)) {
+		/* This means we searched and got rp node, needs unlock */
+		route_unlock_node(rn);
+
+		if (active && pend) {
+			if (pim_addr_cmp(active->rp_address, pend->rp_address))
+				pim_rp_change(pim, pend->rp_address,
+					      bsgrp_node->group, RP_SRC_BSR);
+		}
+
+		/* Possible when the first BSM has group with 0 rp count */
+		if ((!active) && (!pend)) {
+			if (PIM_DEBUG_BSM) {
+				zlog_debug(
+					"%s: Both bsrp and partial list are empty",
+					__func__);
+			}
+			pim_free_bsgrp_node(bsgrp_node->scope->bsrp_table,
+					    &bsgrp_node->group);
+			pim_free_bsgrp_data(bsgrp_node);
+			return;
+		}
+
+		/* Possible when a group with 0 rp count received in BSM */
+		if ((active) && (!pend)) {
+			pim_rp_del(pim, active->rp_address, bsgrp_node->group,
+				   NULL, RP_SRC_BSR);
+			pim_free_bsgrp_node(bsgrp_node->scope->bsrp_table,
+					    &bsgrp_node->group);
+			if (PIM_DEBUG_BSM) {
+				zlog_debug("%s:Pend List is null,del grp node",
+					   __func__);
+			}
+			pim_free_bsgrp_data(bsgrp_node);
+			return;
+		}
+	}
+
+	if ((had_rp_node) && (rp_info->rp_src == RP_SRC_STATIC)) {
+		/* We need to unlock rn this case */
+		route_unlock_node(rn);
+		/* there is a chance that static rp exist and bsrp cleaned
+		 * so clean bsgrp node if pending list empty
+		 */
+		if (!pend) {
+			if (PIM_DEBUG_BSM)
+				zlog_debug(
+					"%s: Partial list is empty, static rp exists",
+					__func__);
+			pim_free_bsgrp_node(bsgrp_node->scope->bsrp_table,
+					    &bsgrp_node->group);
+			pim_free_bsgrp_data(bsgrp_node);
+			return;
+		}
+	}
+
+	/* swap the list & delete all nodes in partial list (old bsrp_list)
+	 * before swap
+	 *    active is head of bsrp list
+	 *    pend is head of partial list
+	 * After swap
+	 *    active is head of partial list
+	 *    pend is head of bsrp list
+	 * So check appriate head after swap and clean the new partial list
+	 */
+	bsm_rpinfos_swap_all(bsgrp_node->bsrp_list,
+			     bsgrp_node->partial_bsrp_list);
+
+	if (active)
+		pim_g2rp_timer_stop(active);
+	pim_bsm_rpinfos_free(bsgrp_node->partial_bsrp_list);
+}
+
+static bool is_preferred_bsr(struct pim_instance *pim, pim_addr bsr,
+			     uint32_t bsr_prio)
+{
+	if (!pim_addr_cmp(bsr, pim->global_scope.current_bsr))
+		return true;
+
+	if (bsr_prio > pim->global_scope.current_bsr_prio)
+		return true;
+
+	else if (bsr_prio == pim->global_scope.current_bsr_prio) {
+		if (pim_addr_cmp(bsr, pim->global_scope.current_bsr) >= 0)
+			return true;
+		else
+			return false;
+	} else
+		return false;
+}
+
+static void pim_bsm_update(struct pim_instance *pim, pim_addr bsr,
+			   uint32_t bsr_prio)
+{
+	if (pim_addr_cmp(bsr, pim->global_scope.current_bsr)) {
+		pim_nht_bsr_del(pim, pim->global_scope.current_bsr);
+		pim_nht_bsr_add(pim, bsr);
+
+		pim->global_scope.current_bsr = bsr;
+		pim->global_scope.current_bsr_first_ts =
+			pim_time_monotonic_sec();
+		pim->global_scope.state = ACCEPT_PREFERRED;
+	}
+	pim->global_scope.current_bsr_prio = bsr_prio;
+	pim->global_scope.current_bsr_last_ts = pim_time_monotonic_sec();
+}
+
+void pim_bsm_clear(struct pim_instance *pim)
+{
+	struct route_node *rn;
+	struct route_node *rpnode;
+	struct bsgrp_node *bsgrp;
+	pim_addr nht_p;
+	struct prefix g_all;
+	struct rp_info *rp_all;
+	struct pim_upstream *up;
+	struct rp_info *rp_info;
+	bool upstream_updated = false;
+
+	pim_nht_bsr_del(pim, pim->global_scope.current_bsr);
+
+	/* Reset scope zone data */
+	pim->global_scope.accept_nofwd_bsm = false;
+	pim->global_scope.state = ACCEPT_ANY;
+	pim->global_scope.current_bsr = PIMADDR_ANY;
+	pim->global_scope.current_bsr_prio = 0;
+	pim->global_scope.current_bsr_first_ts = 0;
+	pim->global_scope.current_bsr_last_ts = 0;
+	pim->global_scope.bsm_frag_tag = 0;
+	pim_bsm_frags_free(&pim->global_scope);
+
+	pim_bs_timer_stop(&pim->global_scope);
+
+	for (rn = route_top(pim->global_scope.bsrp_table); rn;
+	     rn = route_next(rn)) {
+		bsgrp = rn->info;
+		if (!bsgrp)
+			continue;
+
+		rpnode = route_node_lookup(pim->rp_table, &bsgrp->group);
+
+		if (!rpnode) {
+			pim_free_bsgrp_node(bsgrp->scope->bsrp_table,
+					    &bsgrp->group);
+			pim_free_bsgrp_data(bsgrp);
+			continue;
+		}
+
+		rp_info = (struct rp_info *)rpnode->info;
+
+		if ((!rp_info) || (rp_info->rp_src != RP_SRC_BSR)) {
+			pim_free_bsgrp_node(bsgrp->scope->bsrp_table,
+					    &bsgrp->group);
+			pim_free_bsgrp_data(bsgrp);
+			continue;
+		}
+
+		/* Deregister addr with Zebra NHT */
+		nht_p = rp_info->rp.rpf_addr;
+
+		if (PIM_DEBUG_PIM_NHT_RP) {
+			zlog_debug("%s: Deregister RP addr %pPA with Zebra ",
+				   __func__, &nht_p);
+		}
+
+		pim_delete_tracked_nexthop(pim, nht_p, NULL, rp_info);
+
+		if (!pim_get_all_mcast_group(&g_all))
+			return;
+
+		rp_all = pim_rp_find_match_group(pim, &g_all);
+
+		if (rp_all == rp_info) {
+			rp_all->rp.rpf_addr = PIMADDR_ANY;
+			rp_all->i_am_rp = 0;
+		} else {
+			/* Delete the rp_info from rp-list */
+			listnode_delete(pim->rp_list, rp_info);
+
+			/* Delete the rp node from rp_table */
+			rpnode->info = NULL;
+			route_unlock_node(rpnode);
+			route_unlock_node(rpnode);
+			XFREE(MTYPE_PIM_RP, rp_info);
+		}
+
+		pim_free_bsgrp_node(bsgrp->scope->bsrp_table, &bsgrp->group);
+		pim_free_bsgrp_data(bsgrp);
+	}
+	pim_rp_refresh_group_to_rp_mapping(pim);
+
+
+	frr_each (rb_pim_upstream, &pim->upstream_head, up) {
+		/* Find the upstream (*, G) whose upstream address is same as
+		 * the RP
+		 */
+		if (!pim_addr_is_any(up->sg.src))
+			continue;
+
+		struct prefix grp;
+		struct rp_info *trp_info;
+
+		pim_addr_to_prefix(&grp, up->sg.grp);
+		trp_info = pim_rp_find_match_group(pim, &grp);
+
+		/* RP not found for the group grp */
+		if (pim_rpf_addr_is_inaddr_any(&trp_info->rp)) {
+			pim_upstream_rpf_clear(pim, up);
+			pim_rp_set_upstream_addr(pim, &up->upstream_addr,
+						 up->sg.src, up->sg.grp);
+		} else {
+			/* RP found for the group grp */
+			pim_upstream_update(pim, up);
+			upstream_updated = true;
+		}
+	}
+
+	if (upstream_updated)
+		pim_zebra_update_all_interfaces(pim);
+}
+
+static bool pim_bsm_send_intf(uint8_t *buf, int len, struct interface *ifp,
+			      pim_addr dst_addr)
+{
+	struct pim_interface *pim_ifp;
+
+	pim_ifp = ifp->info;
+
+	if (!pim_ifp) {
+		if (PIM_DEBUG_BSM)
+			zlog_debug("%s: Pim interface not available for %s",
+				   __func__, ifp->name);
+		return false;
+	}
+
+	if (pim_ifp->pim_sock_fd == -1) {
+		if (PIM_DEBUG_BSM)
+			zlog_debug("%s: Pim sock not available for %s",
+				   __func__, ifp->name);
+		return false;
+	}
+
+	if (pim_msg_send(pim_ifp->pim_sock_fd, pim_ifp->primary_address,
+			 dst_addr, buf, len, ifp)) {
+		zlog_warn("%s: Could not send BSM message on interface: %s",
+			  __func__, ifp->name);
+		return false;
+	}
+
+	if (!pim_ifp->pim_passive_enable)
+		pim_ifp->pim_ifstat_bsm_tx++;
+
+	pim_ifp->pim->bsm_sent++;
+	return true;
+}
+
+static bool pim_bsm_frag_send(uint8_t *buf, uint32_t len, struct interface *ifp,
+			      uint32_t pim_mtu, pim_addr dst_addr, bool no_fwd)
+{
+	struct pim_interface *pim_ifp = ifp->info;
+	struct bsmmsg_grpinfo *grpinfo, *curgrp;
+	uint8_t *firstgrp_ptr;
+	uint8_t *pkt;
+	uint8_t *pak_start;
+	uint32_t parsed_len = 0;
+	uint32_t this_pkt_rem;
+	uint32_t copy_byte_count;
+	uint32_t this_pkt_len;
+	uint8_t total_rp_cnt;
+	uint8_t this_rp_cnt;
+	uint8_t frag_rp_cnt;
+	uint8_t rp_fit_cnt;
+	bool pak_pending = false;
+
+	/* MTU  passed here is PIM MTU (IP MTU less IP Hdr) */
+	if (pim_mtu < (PIM_MIN_BSM_LEN)) {
+		zlog_warn(
+			"%s: mtu(pim mtu: %d) size less than minimum bootstrap len",
+			__func__, pim_mtu);
+		if (PIM_DEBUG_BSM)
+			zlog_debug(
+				"%s: mtu (pim mtu:%d) less than minimum bootstrap len",
+				__func__, pim_mtu);
+		return false;
+	}
+
+	pak_start = XCALLOC(MTYPE_PIM_BSM_PKT_VAR_MEM, pim_mtu);
+
+	pkt = pak_start;
+
+	/* Fill PIM header later before sending packet to calc checksum */
+	pkt += PIM_MSG_HEADER_LEN;
+	buf += PIM_MSG_HEADER_LEN;
+
+	/* copy bsm header to new packet at offset of pim hdr */
+	memcpy(pkt, buf, PIM_BSM_HDR_LEN);
+	pkt += PIM_BSM_HDR_LEN;
+	buf += PIM_BSM_HDR_LEN;
+	parsed_len += (PIM_MSG_HEADER_LEN + PIM_BSM_HDR_LEN);
+
+	/* Store the position of first grp ptr, which can be reused for
+	 * next packet to start filling group. old bsm header and pim hdr
+	 * remains. So need not be filled again for next packet onwards.
+	 */
+	firstgrp_ptr = pkt;
+
+	/* we received mtu excluding IP hdr len as param
+	 * now this_pkt_rem is mtu excluding
+	 * PIM_BSM_HDR_LEN + PIM_MSG_HEADER_LEN
+	 */
+	this_pkt_rem = pim_mtu - (PIM_BSM_HDR_LEN + PIM_MSG_HEADER_LEN);
+
+	/* For each group till the packet length parsed */
+	while (parsed_len < len) {
+		/* pkt            ---> fragment's current pointer
+		 * buf            ---> input buffer's current pointer
+		 * mtu            ---> size of the pim packet - PIM header
+		 * curgrp         ---> current group on the fragment
+		 * grpinfo        ---> current group on the input buffer
+		 * this_pkt_rem   ---> bytes remaing on the current fragment
+		 * rp_fit_cnt     ---> num of rp for current grp that
+		 *                     fits this frag
+		 * total_rp_cnt   ---> total rp present for the group in the buf
+		 * frag_rp_cnt    ---> no of rp for the group to be fit in
+		 *                     the frag
+		 * this_rp_cnt    ---> how many rp have we parsed
+		 */
+		grpinfo = (struct bsmmsg_grpinfo *)buf;
+		memcpy(pkt, buf, PIM_BSM_GRP_LEN);
+		curgrp = (struct bsmmsg_grpinfo *)pkt;
+		parsed_len += PIM_BSM_GRP_LEN;
+		pkt += PIM_BSM_GRP_LEN;
+		buf += PIM_BSM_GRP_LEN;
+		this_pkt_rem -= PIM_BSM_GRP_LEN;
+
+		/* initialize rp count and total_rp_cnt before the rp loop */
+		this_rp_cnt = 0;
+		total_rp_cnt = grpinfo->frag_rp_count;
+
+		/* Loop till all RPs for the group parsed */
+		while (this_rp_cnt < total_rp_cnt) {
+			/* All RP from a group processed here.
+			 * group is pointed by grpinfo.
+			 * At this point make sure buf pointing to a RP
+			 * within a group
+			 */
+			rp_fit_cnt = this_pkt_rem / PIM_BSM_RP_LEN;
+
+			/* calculate how many rp am i going to copy in
+			 * this frag
+			 */
+			if (rp_fit_cnt > (total_rp_cnt - this_rp_cnt))
+				frag_rp_cnt = total_rp_cnt - this_rp_cnt;
+			else
+				frag_rp_cnt = rp_fit_cnt;
+
+			/* populate the frag rp count for the current grp */
+			curgrp->frag_rp_count = frag_rp_cnt;
+			copy_byte_count = frag_rp_cnt * PIM_BSM_RP_LEN;
+
+			/* copy all the rp that we are fitting in this
+			 * frag for the grp
+			 */
+			memcpy(pkt, buf, copy_byte_count);
+			this_rp_cnt += frag_rp_cnt;
+			buf += copy_byte_count;
+			pkt += copy_byte_count;
+			parsed_len += copy_byte_count;
+			this_pkt_rem -= copy_byte_count;
+
+			/* Either we couldn't fit all rp for the group or the
+			 * mtu reached
+			 */
+			if ((this_rp_cnt < total_rp_cnt)
+			    || (this_pkt_rem
+				< (PIM_BSM_GRP_LEN + PIM_BSM_RP_LEN))) {
+				/* No space to fit in more rp, send this pkt */
+				this_pkt_len = pim_mtu - this_pkt_rem;
+				pim_msg_build_header(
+					pim_ifp->primary_address, dst_addr,
+					pak_start, this_pkt_len,
+					PIM_MSG_TYPE_BOOTSTRAP, no_fwd);
+				pim_bsm_send_intf(pak_start, this_pkt_len, ifp,
+						  dst_addr);
+
+				/* Construct next fragment. Reuse old packet */
+				pkt = firstgrp_ptr;
+				this_pkt_rem = pim_mtu - (PIM_BSM_HDR_LEN
+							  + PIM_MSG_HEADER_LEN);
+
+				/* If pkt can't accommodate next group + at
+				 * least one rp, we must break out of this inner
+				 * loop and process next RP
+				 */
+				if (total_rp_cnt == this_rp_cnt)
+					break;
+
+				/* If some more RPs for the same group pending,
+				 * fill grp hdr
+				 */
+				memcpy(pkt, (uint8_t *)grpinfo,
+				       PIM_BSM_GRP_LEN);
+				curgrp = (struct bsmmsg_grpinfo *)pkt;
+				pkt += PIM_BSM_GRP_LEN;
+				this_pkt_rem -= PIM_BSM_GRP_LEN;
+				pak_pending = false;
+			} else {
+				/* We filled something but not yet sent out */
+				pak_pending = true;
+			}
+		} /* while RP count */
+	}	 /*while parsed len */
+
+	/* Send if we have any unsent packet */
+	if (pak_pending) {
+		this_pkt_len = pim_mtu - this_pkt_rem;
+		pim_msg_build_header(pim_ifp->primary_address, dst_addr,
+				     pak_start, this_pkt_len,
+				     PIM_MSG_TYPE_BOOTSTRAP, no_fwd);
+		pim_bsm_send_intf(pak_start, (pim_mtu - this_pkt_rem), ifp,
+				  dst_addr);
+	}
+	XFREE(MTYPE_PIM_BSM_PKT_VAR_MEM, pak_start);
+	return true;
+}
+
+static void pim_bsm_fwd_whole_sz(struct pim_instance *pim, uint8_t *buf,
+				 uint32_t len, int sz)
+{
+	struct interface *ifp;
+	struct pim_interface *pim_ifp;
+	pim_addr dst_addr;
+	uint32_t pim_mtu;
+	bool no_fwd = false;
+	bool ret = false;
+
+	/* For now only global scope zone is supported, so send on all
+	 * pim interfaces in the vrf
+	 */
+	dst_addr = qpim_all_pim_routers_addr;
+	FOR_ALL_INTERFACES (pim->vrf, ifp) {
+		pim_ifp = ifp->info;
+		if ((!pim_ifp) || (!pim_ifp->bsm_enable))
+			continue;
+
+		/*
+		 * RFC 5059 Sec 3.4:
+		 * When a Bootstrap message is forwarded, it is forwarded out
+		 * of every multicast-capable interface that has PIM neighbors.
+		 *
+		 * So skipping pim interfaces with no neighbors.
+		 */
+		if (listcount(pim_ifp->pim_neighbor_list) == 0)
+			continue;
+
+		pim_hello_require(ifp);
+		pim_mtu = ifp->mtu - MAX_IP_HDR_LEN;
+		if (pim_mtu < len) {
+			ret = pim_bsm_frag_send(buf, len, ifp, pim_mtu,
+						dst_addr, no_fwd);
+			if (PIM_DEBUG_BSM)
+				zlog_debug("%s: pim_bsm_frag_send returned %s",
+					   __func__, ret ? "TRUE" : "FALSE");
+		} else {
+			pim_msg_build_header(pim_ifp->primary_address, dst_addr,
+					     buf, len, PIM_MSG_TYPE_BOOTSTRAP,
+					     no_fwd);
+			if (!pim_bsm_send_intf(buf, len, ifp, dst_addr)) {
+				if (PIM_DEBUG_BSM)
+					zlog_debug(
+						"%s: pim_bsm_send_intf returned false",
+						__func__);
+			}
+		}
+	}
+}
+
+bool pim_bsm_new_nbr_fwd(struct pim_neighbor *neigh, struct interface *ifp)
+{
+	pim_addr dst_addr;
+	struct pim_interface *pim_ifp;
+	struct bsm_scope *scope;
+	struct bsm_frag *bsfrag;
+	uint32_t pim_mtu;
+	bool no_fwd = true;
+	bool ret = false;
+
+	if (PIM_DEBUG_BSM)
+		zlog_debug("%s: New neighbor %pPA seen on %s", __func__,
+			   &neigh->source_addr, ifp->name);
+
+	pim_ifp = ifp->info;
+
+	/* DR only forwards BSM packet */
+	if (!pim_addr_cmp(pim_ifp->pim_dr_addr, pim_ifp->primary_address)) {
+		if (PIM_DEBUG_BSM)
+			zlog_debug(
+				"%s: It is not DR, so don't forward BSM packet",
+				__func__);
+	}
+
+	if (!pim_ifp->bsm_enable) {
+		if (PIM_DEBUG_BSM)
+			zlog_debug("%s: BSM proc not enabled on %s", __func__,
+				   ifp->name);
+		return ret;
+	}
+
+	scope = &pim_ifp->pim->global_scope;
+
+	if (!bsm_frags_count(scope->bsm_frags)) {
+		if (PIM_DEBUG_BSM)
+			zlog_debug("%s: BSM list for the scope is empty",
+				   __func__);
+		return ret;
+	}
+
+	if (!pim_ifp->ucast_bsm_accept) {
+		dst_addr = qpim_all_pim_routers_addr;
+		if (PIM_DEBUG_BSM)
+			zlog_debug("%s: Sending BSM mcast to %pPA", __func__,
+				   &neigh->source_addr);
+	} else {
+		dst_addr = neigh->source_addr;
+		if (PIM_DEBUG_BSM)
+			zlog_debug("%s: Sending BSM ucast to %pPA", __func__,
+				   &neigh->source_addr);
+	}
+	pim_mtu = ifp->mtu - MAX_IP_HDR_LEN;
+	pim_hello_require(ifp);
+
+	frr_each (bsm_frags, scope->bsm_frags, bsfrag) {
+		if (pim_mtu < bsfrag->size) {
+			ret = pim_bsm_frag_send(bsfrag->data, bsfrag->size, ifp,
+						pim_mtu, dst_addr, no_fwd);
+			if (!ret) {
+				if (PIM_DEBUG_BSM)
+					zlog_debug(
+						"%s: pim_bsm_frag_send failed",
+						__func__);
+			}
+		} else {
+			/* Pim header needs to be constructed */
+			pim_msg_build_header(pim_ifp->primary_address, dst_addr,
+					     bsfrag->data, bsfrag->size,
+					     PIM_MSG_TYPE_BOOTSTRAP, no_fwd);
+			ret = pim_bsm_send_intf(bsfrag->data, bsfrag->size, ifp,
+						dst_addr);
+			if (!ret) {
+				if (PIM_DEBUG_BSM)
+					zlog_debug(
+						"%s: pim_bsm_frag_send failed",
+						__func__);
+			}
+		}
+	}
+	return ret;
+}
+
+struct bsgrp_node *pim_bsm_get_bsgrp_node(struct bsm_scope *scope,
+					  struct prefix *grp)
+{
+	struct route_node *rn;
+	struct bsgrp_node *bsgrp;
+
+	rn = route_node_lookup(scope->bsrp_table, grp);
+	if (!rn) {
+		if (PIM_DEBUG_BSM)
+			zlog_debug("%s: Route node doesn't exist for the group",
+				   __func__);
+		return NULL;
+	}
+	bsgrp = rn->info;
+	route_unlock_node(rn);
+
+	return bsgrp;
+}
+
+static uint32_t hash_calc_on_grp_rp(struct prefix group, pim_addr rp,
+				    uint8_t hashmasklen)
+{
+	uint64_t temp;
+	uint32_t hash;
+	uint32_t grpaddr;
+	uint32_t rp_add;
+	uint32_t mask = 0xffffffff;
+
+	/* mask to be made zero if hashmasklen is 0 because mask << 32
+	 * may not give 0. hashmasklen can be 0 to 32.
+	 */
+	if (hashmasklen == 0)
+		mask = 0;
+
+	/* in_addr stores ip in big endian, hence network byte order
+	 * convert to uint32 before processing hash
+	 */
+#if PIM_IPV == 4
+	grpaddr = ntohl(group.u.prefix4.s_addr);
+#else
+	grpaddr = group.u.prefix6.s6_addr32[0] ^ group.u.prefix6.s6_addr32[1] ^
+		  group.u.prefix6.s6_addr32[2] ^ group.u.prefix6.s6_addr32[3];
+#endif
+	/* Avoid shifting by 32 bit on a 32 bit register */
+	if (hashmasklen)
+		grpaddr = grpaddr & ((mask << (32 - hashmasklen)));
+	else
+		grpaddr = grpaddr & mask;
+
+#if PIM_IPV == 4
+	rp_add = ntohl(rp.s_addr);
+#else
+	rp_add = rp.s6_addr32[0] ^ rp.s6_addr32[1] ^ rp.s6_addr32[2] ^
+		 rp.s6_addr32[3];
+#endif
+	temp = 1103515245 * ((1103515245 * (uint64_t)grpaddr + 12345) ^ rp_add)
+	       + 12345;
+	hash = temp & (0x7fffffff);
+	return hash;
+}
+
+static bool pim_install_bsm_grp_rp(struct pim_instance *pim,
+				   struct bsgrp_node *grpnode,
+				   struct bsmmsg_rpinfo *rp)
+{
+	struct bsm_rpinfo *bsm_rpinfo;
+	uint8_t hashMask_len = pim->global_scope.hashMasklen;
+
+	/*memory allocation for bsm_rpinfo */
+	bsm_rpinfo = XCALLOC(MTYPE_PIM_BSRP_INFO, sizeof(*bsm_rpinfo));
+
+	bsm_rpinfo->rp_prio = rp->rp_pri;
+	bsm_rpinfo->rp_holdtime = rp->rp_holdtime;
+	bsm_rpinfo->rp_address = rp->rpaddr.addr;
+	bsm_rpinfo->elapse_time = 0;
+
+	/* Back pointer to the group node. */
+	bsm_rpinfo->bsgrp_node = grpnode;
+
+	/* update hash for this rp node */
+	bsm_rpinfo->hash = hash_calc_on_grp_rp(grpnode->group, rp->rpaddr.addr,
+					       hashMask_len);
+	if (bsm_rpinfos_add(grpnode->partial_bsrp_list, bsm_rpinfo) == NULL) {
+		if (PIM_DEBUG_BSM)
+			zlog_debug(
+				"%s, bs_rpinfo node added to the partial bs_rplist.",
+				__func__);
+		return true;
+	}
+
+	if (PIM_DEBUG_BSM)
+		zlog_debug("%s: list node not added", __func__);
+
+	XFREE(MTYPE_PIM_BSRP_INFO, bsm_rpinfo);
+	return false;
+}
+
+static void pim_update_pending_rp_cnt(struct bsm_scope *sz,
+				      struct bsgrp_node *bsgrp,
+				      uint16_t bsm_frag_tag,
+				      uint32_t total_rp_count)
+{
+	if (bsgrp->pend_rp_cnt) {
+		/* received bsm is different packet ,
+		 * it is not same fragment.
+		 */
+		if (bsm_frag_tag != bsgrp->frag_tag) {
+			if (PIM_DEBUG_BSM)
+				zlog_debug(
+					"%s,Received a new BSM ,so clear the pending bs_rpinfo list.",
+					__func__);
+			pim_bsm_rpinfos_free(bsgrp->partial_bsrp_list);
+			bsgrp->pend_rp_cnt = total_rp_count;
+		}
+	} else
+		bsgrp->pend_rp_cnt = total_rp_count;
+
+	bsgrp->frag_tag = bsm_frag_tag;
+}
+
+/* Parsing BSR packet and adding to partial list of corresponding bsgrp node */
+static bool pim_bsm_parse_install_g2rp(struct bsm_scope *scope, uint8_t *buf,
+				       int buflen, uint16_t bsm_frag_tag)
+{
+	struct bsmmsg_grpinfo grpinfo;
+	struct bsmmsg_rpinfo rpinfo;
+	struct prefix group;
+	struct bsgrp_node *bsgrp = NULL;
+	int frag_rp_cnt = 0;
+	int offset = 0;
+	int ins_count = 0;
+	pim_addr grp_addr;
+
+	while (buflen > offset) {
+		if (offset + (int)sizeof(struct bsmmsg_grpinfo) > buflen) {
+			if (PIM_DEBUG_BSM)
+				zlog_debug(
+					"%s: buflen received %d is less than the internal data structure of the packet would suggest",
+					__func__, buflen);
+			return false;
+		}
+		/* Extract Group tlv from BSM */
+		memcpy(&grpinfo, buf, sizeof(struct bsmmsg_grpinfo));
+		grp_addr = grpinfo.group.addr;
+
+		if (PIM_DEBUG_BSM)
+			zlog_debug(
+				"%s, Group %pPAs  Rpcount:%d Fragment-Rp-count:%d",
+				__func__, &grp_addr, grpinfo.rp_count,
+				grpinfo.frag_rp_count);
+
+		buf += sizeof(struct bsmmsg_grpinfo);
+		offset += sizeof(struct bsmmsg_grpinfo);
+
+		group.family = PIM_AF;
+		if (grpinfo.group.mask > PIM_MAX_BITLEN) {
+			if (PIM_DEBUG_BSM)
+				zlog_debug(
+					"%s, prefix length specified: %d is too long",
+					__func__, grpinfo.group.mask);
+			return false;
+		}
+
+		pim_addr_to_prefix(&group, grp_addr);
+		group.prefixlen = grpinfo.group.mask;
+
+		/* Get the Group node for the BSM rp table */
+		bsgrp = pim_bsm_get_bsgrp_node(scope, &group);
+
+		if (grpinfo.rp_count == 0) {
+			struct bsm_rpinfo *old_rpinfo;
+
+			/* BSR explicitly no longer has RPs for this group */
+			if (!bsgrp)
+				continue;
+
+			if (PIM_DEBUG_BSM)
+				zlog_debug(
+					"%s, Rp count is zero for group: %pPAs",
+					__func__, &grp_addr);
+
+			old_rpinfo = bsm_rpinfos_first(bsgrp->bsrp_list);
+			if (old_rpinfo)
+				pim_rp_del(scope->pim, old_rpinfo->rp_address,
+					   group, NULL, RP_SRC_BSR);
+
+			pim_free_bsgrp_node(scope->bsrp_table, &bsgrp->group);
+			pim_free_bsgrp_data(bsgrp);
+			continue;
+		}
+
+		if (!bsgrp) {
+			if (PIM_DEBUG_BSM)
+				zlog_debug("%s, Create new  BSM Group node.",
+					   __func__);
+
+			/* create a new node to be added to the tree. */
+			bsgrp = pim_bsm_new_bsgrp_node(scope->bsrp_table,
+						       &group);
+
+			if (!bsgrp) {
+				zlog_debug(
+					"%s, Failed to get the BSM group node.",
+					__func__);
+				continue;
+			}
+
+			bsgrp->scope = scope;
+		}
+
+		pim_update_pending_rp_cnt(scope, bsgrp, bsm_frag_tag,
+					  grpinfo.rp_count);
+		frag_rp_cnt = grpinfo.frag_rp_count;
+		ins_count = 0;
+
+		while (frag_rp_cnt--) {
+			if (offset + (int)sizeof(struct bsmmsg_rpinfo)
+			    > buflen) {
+				if (PIM_DEBUG_BSM)
+					zlog_debug(
+						"%s, buflen received: %u is less than the internal data structure of the packet would suggest",
+						__func__, buflen);
+				return false;
+			}
+
+			/* Extract RP address tlv from BSM */
+			memcpy(&rpinfo, buf, sizeof(struct bsmmsg_rpinfo));
+			rpinfo.rp_holdtime = ntohs(rpinfo.rp_holdtime);
+			buf += sizeof(struct bsmmsg_rpinfo);
+			offset += sizeof(struct bsmmsg_rpinfo);
+
+			if (PIM_DEBUG_BSM) {
+				pim_addr rp_addr;
+
+				rp_addr = rpinfo.rpaddr.addr;
+				zlog_debug(
+					"%s, Rp address - %pPAs; pri:%d hold:%d",
+					__func__, &rp_addr, rpinfo.rp_pri,
+					rpinfo.rp_holdtime);
+			}
+
+			/* Call Install api to update grp-rp mappings */
+			if (pim_install_bsm_grp_rp(scope->pim, bsgrp, &rpinfo))
+				ins_count++;
+		}
+
+		bsgrp->pend_rp_cnt -= ins_count;
+
+		if (!bsgrp->pend_rp_cnt) {
+			if (PIM_DEBUG_BSM)
+				zlog_debug(
+					"%s, Recvd all the rps for this group, so bsrp list with penidng rp list.",
+					__func__);
+			/* replace the bsrp_list with pending list */
+			pim_instate_pend_list(bsgrp);
+		}
+	}
+	return true;
+}
+
+int pim_bsm_process(struct interface *ifp, pim_sgaddr *sg, uint8_t *buf,
+		    uint32_t buf_size, bool no_fwd)
+{
+	struct bsm_hdr *bshdr;
+	int sz = PIM_GBL_SZ_ID;
+	struct bsmmsg_grpinfo *msg_grp;
+	struct pim_interface *pim_ifp = NULL;
+	struct bsm_frag *bsfrag;
+	struct pim_instance *pim;
+	uint16_t frag_tag;
+	pim_addr bsr_addr;
+	bool empty_bsm = false;
+
+	/* BSM Packet acceptance validation */
+	pim_ifp = ifp->info;
+	if (!pim_ifp) {
+		if (PIM_DEBUG_BSM)
+			zlog_debug("%s: multicast not enabled on interface %s",
+				   __func__, ifp->name);
+		return -1;
+	}
+
+	if (pim_ifp->pim_passive_enable) {
+		if (PIM_DEBUG_PIM_PACKETS)
+			zlog_debug(
+				"skip receiving PIM message on passive interface %s",
+				ifp->name);
+		return 0;
+	}
+
+	pim_ifp->pim_ifstat_bsm_rx++;
+	pim = pim_ifp->pim;
+	pim->bsm_rcvd++;
+
+	/* Drop if bsm processing is disabled on interface */
+	if (!pim_ifp->bsm_enable) {
+		zlog_warn("%s: BSM not enabled on interface %s", __func__,
+			  ifp->name);
+		pim_ifp->pim_ifstat_bsm_cfg_miss++;
+		pim->bsm_dropped++;
+		return -1;
+	}
+
+	if (buf_size < (PIM_MSG_HEADER_LEN + sizeof(struct bsm_hdr))) {
+		if (PIM_DEBUG_BSM)
+			zlog_debug(
+				"%s: received buffer length of %d which is too small to properly decode",
+				__func__, buf_size);
+		return -1;
+	}
+
+	bshdr = (struct bsm_hdr *)(buf + PIM_MSG_HEADER_LEN);
+	if (bshdr->hm_len > PIM_MAX_BITLEN) {
+		zlog_warn(
+			"Bad hashmask length for %s; got %hhu, expected value in range 0-32",
+			PIM_AF_NAME, bshdr->hm_len);
+		pim->bsm_dropped++;
+		return -1;
+	}
+	pim->global_scope.hashMasklen = bshdr->hm_len;
+	frag_tag = ntohs(bshdr->frag_tag);
+	/* NB: bshdr->bsr_addr.addr is packed/unaligned => memcpy */
+	memcpy(&bsr_addr, &bshdr->bsr_addr.addr, sizeof(bsr_addr));
+
+	/* Identify empty BSM */
+	if ((buf_size - PIM_BSM_HDR_LEN - PIM_MSG_HEADER_LEN) < PIM_BSM_GRP_LEN)
+		empty_bsm = true;
+
+	if (!empty_bsm) {
+		msg_grp = (struct bsmmsg_grpinfo *)(buf + PIM_MSG_HEADER_LEN
+						    + PIM_BSM_HDR_LEN);
+		/* Currently we don't support scope zoned BSM */
+		if (msg_grp->group.sz) {
+			if (PIM_DEBUG_BSM)
+				zlog_debug(
+					"%s : Administratively scoped range BSM received",
+					__func__);
+			pim_ifp->pim_ifstat_bsm_invalid_sz++;
+			pim->bsm_dropped++;
+			return -1;
+		}
+	}
+
+	/* Drop if bsr is not preferred bsr */
+	if (!is_preferred_bsr(pim, bsr_addr, bshdr->bsr_prio)) {
+		if (PIM_DEBUG_BSM)
+			zlog_debug("%s : Received a non-preferred BSM",
+				   __func__);
+		pim->bsm_dropped++;
+		return -1;
+	}
+
+	if (no_fwd) {
+		/* only accept no-forward BSM if quick refresh on startup */
+		if ((pim->global_scope.accept_nofwd_bsm)
+		    || (frag_tag == pim->global_scope.bsm_frag_tag)) {
+			pim->global_scope.accept_nofwd_bsm = false;
+		} else {
+			if (PIM_DEBUG_BSM)
+				zlog_debug(
+					"%s : nofwd_bsm received on %pPAs when accpt_nofwd_bsm false",
+					__func__, &bsr_addr);
+			pim->bsm_dropped++;
+			pim_ifp->pim_ifstat_ucast_bsm_cfg_miss++;
+			return -1;
+		}
+	}
+
+	/* 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
+		 * no-forward set
+		 */
+		if (!no_fwd &&
+		    !pim_nht_bsr_rpf_check(pim, bsr_addr, ifp, sg->src)) {
+			if (PIM_DEBUG_BSM)
+				zlog_debug(
+					"BSM check: RPF to BSR %pPAs is not %pPA%%%s",
+					&bsr_addr, &sg->src, ifp->name);
+			pim->bsm_dropped++;
+			return -1;
+		}
+	} else if (if_address_is_local(&sg->grp, PIM_AF, pim->vrf->vrf_id)) {
+		/* Unicast BSM received - if ucast bsm not enabled on
+		 * the interface, drop it
+		 */
+		if (!pim_ifp->ucast_bsm_accept) {
+			if (PIM_DEBUG_BSM)
+				zlog_debug(
+					"%s : Unicast BSM not enabled on interface %s",
+					__func__, ifp->name);
+			pim_ifp->pim_ifstat_ucast_bsm_cfg_miss++;
+			pim->bsm_dropped++;
+			return -1;
+		}
+
+	} else {
+		if (PIM_DEBUG_BSM)
+			zlog_debug("%s : Invalid destination address",
+				   __func__);
+		pim->bsm_dropped++;
+		return -1;
+	}
+
+	if (empty_bsm) {
+		if (PIM_DEBUG_BSM)
+			zlog_debug("%s : Empty Pref BSM received", __func__);
+	}
+	/* Parse Update bsm rp table and install/uninstall rp if required */
+	if (!pim_bsm_parse_install_g2rp(
+		    &pim_ifp->pim->global_scope,
+		    (buf + PIM_BSM_HDR_LEN + PIM_MSG_HEADER_LEN),
+		    (buf_size - PIM_BSM_HDR_LEN - PIM_MSG_HEADER_LEN),
+		    frag_tag)) {
+		if (PIM_DEBUG_BSM) {
+			zlog_debug("%s, Parsing BSM failed.", __func__);
+		}
+		pim->bsm_dropped++;
+		return -1;
+	}
+	/* Restart the bootstrap timer */
+	pim_bs_timer_restart(&pim_ifp->pim->global_scope,
+			     PIM_BSR_DEFAULT_TIMEOUT);
+
+	/* If new BSM received, clear the old bsm database */
+	if (pim_ifp->pim->global_scope.bsm_frag_tag != frag_tag) {
+		if (PIM_DEBUG_BSM) {
+			zlog_debug("%s: Current frag tag: %d Frag teg rcvd: %d",
+				   __func__,
+				   pim_ifp->pim->global_scope.bsm_frag_tag,
+				   frag_tag);
+		}
+		pim_bsm_frags_free(&pim_ifp->pim->global_scope);
+		pim_ifp->pim->global_scope.bsm_frag_tag = frag_tag;
+	}
+
+	/* update the scope information from bsm */
+	pim_bsm_update(pim, bsr_addr, bshdr->bsr_prio);
+
+	if (!no_fwd) {
+		pim_bsm_fwd_whole_sz(pim_ifp->pim, buf, buf_size, sz);
+		bsfrag = XCALLOC(MTYPE_PIM_BSM_FRAG,
+				 sizeof(struct bsm_frag) + buf_size);
+
+		bsfrag->size = buf_size;
+		memcpy(bsfrag->data, buf, buf_size);
+		bsm_frags_add_tail(pim_ifp->pim->global_scope.bsm_frags,
+				   bsfrag);
+	}
+
+	return 0;
+}