pimd: Nexthop tracking support

Add pim Nexthop tracking feature 1st part where, specific RP or Source address (unicast address)
register with Zebra. Once nexthop update received from Zebra for a given address, scan RP or upstream
entries impacted by the change in nexthop.

Reviewed By: CCR-5761, Donald Sharp <sharpd@cumulusnetworks.com>
Testing Done: Tested with multiple RPs and multiple *,G entries at LHR.
Add new Nexthop or remove one of the link towards RP and verify RP and upstream nexthop update.
similar test done at RP with multiple S,G entries to reach source.

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

1 files changed, 22 insertions, 124 deletions

diff --git a/pimd/pim_zebra.c b/pimd/pim_zebra.c
index 1db6616c58..ad4ef64eda 100644
--- a/pimd/pim_zebra.c
+++ b/pimd/pim_zebra.c
@@ -45,6 +45,7 @@
 #include "pim_rp.h"
 #include "pim_igmpv3.h"
 #include "pim_jp_agg.h"
+#include "pim_nht.h"
 
 #undef PIM_DEBUG_IFADDR_DUMP
 #define PIM_DEBUG_IFADDR_DUMP
@@ -375,8 +376,8 @@ static void scan_upstream_rpf_cache()
 
     old.source_nexthop.interface = up->rpf.source_nexthop.interface;
     old.source_nexthop.nbr       = up->rpf.source_nexthop.nbr;
-    rpf_result = pim_rpf_update(up, &old);
-    zlog_debug ("Looking at upstream: %s %d", up->sg_str, rpf_result);
+    rpf_result = pim_rpf_update(up, &old, 0);
+
     if (rpf_result == PIM_RPF_FAILURE)
       continue;
 
@@ -444,7 +445,7 @@ static void scan_upstream_rpf_cache()
 }
 
 void
-pim_scan_individual_oil (struct channel_oil *c_oil)
+pim_scan_individual_oil (struct channel_oil *c_oil, int in_vif_index)
 {
   struct in_addr vif_source;
   int input_iface_vif_index;
@@ -453,7 +454,10 @@ pim_scan_individual_oil (struct channel_oil *c_oil)
   if (!pim_rp_set_upstream_addr (&vif_source, c_oil->oil.mfcc_origin, c_oil->oil.mfcc_mcastgrp))
     return;
 
-  input_iface_vif_index = fib_lookup_if_vif_index (vif_source);
+  if (in_vif_index)
+    input_iface_vif_index = in_vif_index;
+  else
+    input_iface_vif_index = fib_lookup_if_vif_index (vif_source);
   if (input_iface_vif_index < 1)
     {
       if (PIM_DEBUG_ZEBRA)
@@ -548,7 +552,7 @@ void pim_scan_oil()
   ++qpim_scan_oil_events;
 
   for (ALL_LIST_ELEMENTS(pim_channel_oil_list, node, nextnode, c_oil))
-    pim_scan_individual_oil (c_oil);
+    pim_scan_individual_oil (c_oil, 0);
 }
 
 static int on_rpf_cache_refresh(struct thread *t)
@@ -594,124 +598,11 @@ void sched_rpf_cache_refresh(void)
                        0, qpim_rpf_cache_refresh_delay_msec);
 }
 
-static int redist_read_ipv4_route(int command, struct zclient *zclient,
-				  zebra_size_t length, vrf_id_t vrf_id)
+static int
+pim_zebra_nexthop_update (int command, struct zclient *zclient,
+                          zebra_size_t length, vrf_id_t vrf_id)
 {
-  struct stream *s;
-  struct zapi_ipv4 api;
-  ifindex_t ifindex;
-  struct in_addr nexthop;
-  struct prefix_ipv4 p;
-  int min_len = 4;
-
-  if (length < min_len) {
-    zlog_warn("%s %s: short buffer: length=%d min=%d",
-	      __FILE__, __PRETTY_FUNCTION__,
-	      length, min_len);
-    return -1;
-  }
-
-  s = zclient->ibuf;
-  ifindex = 0;
-  nexthop.s_addr = 0;
-
-  /* Type, flags, message. */
-  api.type = stream_getc(s);
-  api.instance = stream_getw (s);
-  api.flags = stream_getl(s);
-  api.message = stream_getc(s);
-
-  /* IPv4 prefix length. */
-  memset(&p, 0, sizeof(struct prefix_ipv4));
-  p.family = AF_INET;
-  p.prefixlen = stream_getc(s);
-
-  min_len +=
-    PSIZE(p.prefixlen) +
-    CHECK_FLAG(api.message, ZAPI_MESSAGE_NEXTHOP) ? 5 : 0 +
-    CHECK_FLAG(api.message, ZAPI_MESSAGE_IFINDEX) ? 5 : 0 +
-    CHECK_FLAG(api.message, ZAPI_MESSAGE_DISTANCE) ? 1 : 0 +
-    CHECK_FLAG(api.message, ZAPI_MESSAGE_METRIC) ? 4 : 0;
-
-  if (PIM_DEBUG_ZEBRA) {
-    zlog_debug("%s %s: length=%d min_len=%d flags=%s%s%s%s",
-	       __FILE__, __PRETTY_FUNCTION__,
-	       length, min_len,
-	       CHECK_FLAG(api.message, ZAPI_MESSAGE_NEXTHOP) ? "nh" : "",
-	       CHECK_FLAG(api.message, ZAPI_MESSAGE_IFINDEX) ? " ifi" : "",
-	       CHECK_FLAG(api.message, ZAPI_MESSAGE_DISTANCE) ? " dist" : "",
-	       CHECK_FLAG(api.message, ZAPI_MESSAGE_METRIC) ? " metr" : "");
-  }
-
-  /* IPv4 prefix. */
-  stream_get(&p.prefix, s, PSIZE(p.prefixlen));
-
-  /* Nexthop, ifindex, distance, metric. */
-  if (CHECK_FLAG(api.message, ZAPI_MESSAGE_NEXTHOP)) {
-    api.nexthop_num = stream_getc(s);
-    nexthop.s_addr = stream_get_ipv4(s);
-  }
-  if (CHECK_FLAG(api.message, ZAPI_MESSAGE_IFINDEX)) {
-    api.ifindex_num = stream_getc(s);
-    ifindex = stream_getl(s);
-  }
-
-  api.distance = CHECK_FLAG(api.message, ZAPI_MESSAGE_DISTANCE) ?
-    stream_getc(s) :
-    0;
-
-  api.metric = CHECK_FLAG(api.message, ZAPI_MESSAGE_METRIC) ?
-    stream_getl(s) :
-    0;
-
-  if (CHECK_FLAG (api.message, ZAPI_MESSAGE_TAG))
-    api.tag = stream_getl (s);
-  else
-    api.tag = 0;
-
-  switch (command) {
-  case ZEBRA_REDISTRIBUTE_IPV4_ADD:
-    if (PIM_DEBUG_ZEBRA) {
-      char buf[2][INET_ADDRSTRLEN];
-      zlog_debug("%s: add %s %s/%d "
-		 "nexthop %s ifindex %d metric%s %u distance%s %u",
-		 __PRETTY_FUNCTION__,
-		 zebra_route_string(api.type),
-		 inet_ntop(AF_INET, &p.prefix, buf[0], sizeof(buf[0])),
-		 p.prefixlen,
-		 inet_ntop(AF_INET, &nexthop, buf[1], sizeof(buf[1])),
-		 ifindex,
-		 CHECK_FLAG(api.message, ZAPI_MESSAGE_METRIC) ? "-recv" : "-miss",
-		 api.metric,
-		 CHECK_FLAG(api.message, ZAPI_MESSAGE_DISTANCE) ? "-recv" : "-miss",
-		 api.distance);
-    }
-    break;
-  case ZEBRA_REDISTRIBUTE_IPV4_DEL:
-    if (PIM_DEBUG_ZEBRA) {
-      char buf[2][INET_ADDRSTRLEN];
-      zlog_debug("%s: delete %s %s/%d "
-		 "nexthop %s ifindex %d metric%s %u distance%s %u",
-		 __PRETTY_FUNCTION__,
-		 zebra_route_string(api.type),
-		 inet_ntop(AF_INET, &p.prefix, buf[0], sizeof(buf[0])),
-		 p.prefixlen,
-		 inet_ntop(AF_INET, &nexthop, buf[1], sizeof(buf[1])),
-		 ifindex,
-		 CHECK_FLAG(api.message, ZAPI_MESSAGE_METRIC) ? "-recv" : "-miss",
-		 api.metric,
-		 CHECK_FLAG(api.message, ZAPI_MESSAGE_DISTANCE) ? "-recv" : "-miss",
-		 api.distance);
-    }
-    break;
-  default:
-    zlog_warn("%s: unknown command=%d", __PRETTY_FUNCTION__, command);
-    return -1;
-  }
-
-  sched_rpf_cache_refresh();
-
-  pim_rp_setup ();
+  pim_parse_nexthop_update (zclient, command, vrf_id);
   return 0;
 }
 
@@ -742,8 +633,7 @@ void pim_zebra_init(void)
   zclient->interface_down           = pim_zebra_if_state_down;
   zclient->interface_address_add    = pim_zebra_if_address_add;
   zclient->interface_address_delete = pim_zebra_if_address_del;
-  zclient->redistribute_route_ipv4_add    = redist_read_ipv4_route;
-  zclient->redistribute_route_ipv4_del    = redist_read_ipv4_route;
+  zclient->nexthop_update           = pim_zebra_nexthop_update;
 
   zclient_init(zclient, ZEBRA_ROUTE_PIM, 0);
   if (PIM_DEBUG_PIM_TRACE) {
@@ -1262,3 +1152,11 @@ pim_zebra_zclient_update (struct vty *vty)
     vty_out(vty, "<null zclient>%s", VTY_NEWLINE);
   }
 }
+
+struct zclient *pim_zebra_zclient_get (void)
+{
+  if (zclient)
+    return zclient;
+  else
+    return NULL;
+}