pimd: update pim upstream structure when RP gets configured

When a new RP is configured, find all the (*, G) upstream whose
group belongs to the new RP and then update the upstream structure
with the below fields.
1. De-register for the old RP.
2. Set the upstream address as new RP
3. Register for the new RP.
4. Update the upstream rpf information and kernel multicast forwarding
cache(MFC), if the new RP is reachable.

Signed-off-by: Sarita Patra <saritap@vmware.com>

1 files changed, 113 insertions, 2 deletions

diff --git a/pimd/pim_rp.c b/pimd/pim_rp.c
index d46f3d853..8f748f990 100644
--- a/pimd/pim_rp.c
+++ b/pimd/pim_rp.c
@@ -45,7 +45,9 @@
 #include "pim_iface.h"
 #include "pim_msdp.h"
 #include "pim_nht.h"
-
+#include "pim_mroute.h"
+#include "pim_oil.h"
+#include "pim_zebra.h"
 
 /* Cleanup pim->rpf_hash each node data */
 void pim_rp_list_hash_clean(void *data)
@@ -201,7 +203,7 @@ static struct rp_info *pim_rp_find_exact(struct pim_instance *pim,
 /*
  * Given a group, return the rp_info for that group
  */
-static struct rp_info *pim_rp_find_match_group(struct pim_instance *pim,
+struct rp_info *pim_rp_find_match_group(struct pim_instance *pim,
 					       const struct prefix *group)
 {
 	struct listnode *node;
@@ -334,6 +336,77 @@ static void pim_rp_check_interfaces(struct pim_instance *pim,
 	}
 }
 
+void pim_upstream_update(struct pim_instance *pim, struct pim_upstream *up)
+{
+	struct pim_rpf old_rpf;
+	enum pim_rpf_result rpf_result;
+	struct in_addr old_upstream_addr;
+	struct in_addr new_upstream_addr;
+	struct prefix nht_p;
+
+	old_upstream_addr = up->upstream_addr;
+	pim_rp_set_upstream_addr(pim, &new_upstream_addr, up->sg.src,
+				 up->sg.grp);
+
+	if (PIM_DEBUG_TRACE)
+		zlog_debug("%s: pim upstream update for  old upstream %s",
+			   __PRETTY_FUNCTION__,
+			   inet_ntoa(old_upstream_addr));
+
+	if (old_upstream_addr.s_addr == new_upstream_addr.s_addr)
+		return;
+
+	/* Lets consider a case, where a PIM upstream has a better RP as a
+	 * result of a new RP configuration with more precise group range.
+	 * This upstream has to be added to the upstream hash of new RP's
+	 * NHT(pnc) and has to be removed from old RP's NHT upstream hash
+	 */
+	if (old_upstream_addr.s_addr != INADDR_ANY) {
+		/* Deregister addr with Zebra NHT */
+		nht_p.family = AF_INET;
+		nht_p.prefixlen = IPV4_MAX_BITLEN;
+		nht_p.u.prefix4 = old_upstream_addr;
+		if (PIM_DEBUG_TRACE) {
+			char buf[PREFIX2STR_BUFFER];
+
+			prefix2str(&nht_p, buf, sizeof(buf));
+			zlog_debug("%s: Deregister upstream %s addr %s with Zebra NHT",
+				   __PRETTY_FUNCTION__, up->sg_str, buf);
+		}
+		pim_delete_tracked_nexthop(pim, &nht_p, up, NULL);
+	}
+
+	/* Update the upstream address */
+	up->upstream_addr = new_upstream_addr;
+
+	old_rpf.source_nexthop.interface = up->rpf.source_nexthop.interface;
+
+	rpf_result = pim_rpf_update(pim, up, &old_rpf, 1);
+	if (rpf_result == PIM_RPF_FAILURE)
+		pim_mroute_del(up->channel_oil, __PRETTY_FUNCTION__);
+
+	/* update kernel multicast forwarding cache (MFC) */
+	if (up->rpf.source_nexthop.interface && up->channel_oil) {
+		ifindex_t ifindex = up->rpf.source_nexthop.interface->ifindex;
+		int vif_index = pim_if_find_vifindex_by_ifindex(pim, ifindex);
+		/* Pass Current selected NH vif index to mroute download */
+		if (vif_index)
+			pim_scan_individual_oil(up->channel_oil, vif_index);
+		else {
+			if (PIM_DEBUG_PIM_NHT)
+				zlog_debug(
+				  "%s: NHT upstream %s channel_oil IIF %s vif_index is not valid",
+				  __PRETTY_FUNCTION__, up->sg_str,
+				  up->rpf.source_nexthop.interface->name);
+		}
+	}
+
+	if (rpf_result == PIM_RPF_CHANGED)
+		pim_zebra_upstream_rpf_changed(pim, up, &old_rpf);
+
+	pim_zebra_update_all_interfaces(pim);
+}
+
 int pim_rp_new(struct pim_instance *pim, const char *rp,
 	       const char *group_range, const char *plist)
 {
@@ -348,6 +421,8 @@ int pim_rp_new(struct pim_instance *pim, const char *rp,
 	struct prefix temp;
 	struct pim_nexthop_cache pnc;
 	struct route_node *rn;
+	struct pim_upstream *up;
+	struct listnode *upnode;
 
 	rp_info = XCALLOC(MTYPE_PIM_RP, sizeof(*rp_info));
 
@@ -469,6 +544,27 @@ int pim_rp_new(struct pim_instance *pim, const char *rp,
 					"%s: NHT Register rp_all addr %s grp %s ",
 					__PRETTY_FUNCTION__, buf, buf1);
 			}
+
+			for (ALL_LIST_ELEMENTS_RO(pim->upstream_list, upnode,
+						  up)) {
+				/* Find (*, G) upstream whose RP is not
+				 * configured yet
+				 */
+				if ((up->upstream_addr.s_addr == INADDR_ANY)
+				    && (up->sg.src.s_addr == INADDR_ANY)) {
+					struct prefix grp;
+					struct rp_info *trp_info;
+
+					grp.family = AF_INET;
+					grp.prefixlen = IPV4_MAX_BITLEN;
+					grp.u.prefix4 = up->sg.grp;
+					trp_info = pim_rp_find_match_group(pim,
+									  &grp);
+					if (trp_info == rp_all)
+						pim_upstream_update(pim, up);
+				}
+			}
+
 			memset(&pnc, 0, sizeof(struct pim_nexthop_cache));
 			if (pim_find_or_track_nexthop(pim, &nht_p, NULL, rp_all,
 						      &pnc)) {
@@ -536,6 +632,21 @@ int pim_rp_new(struct pim_instance *pim, const char *rp,
 			   rn->lock);
 	}
 
+	for (ALL_LIST_ELEMENTS_RO(pim->upstream_list, upnode, up)) {
+		if (up->sg.src.s_addr == INADDR_ANY) {
+			struct prefix grp;
+			struct rp_info *trp_info;
+
+			grp.family = AF_INET;
+			grp.prefixlen = IPV4_MAX_BITLEN;
+			grp.u.prefix4 = up->sg.grp;
+			trp_info = pim_rp_find_match_group(pim, &grp);
+
+			if (trp_info == rp_info)
+				pim_upstream_update(pim, up);
+		}
+	}
+
 	/* Register addr with Zebra NHT */
 	nht_p.family = AF_INET;
 	nht_p.prefixlen = IPV4_MAX_BITLEN;