pimd: Fix RP shenanigans

The RP was not properly handling the series of events:

1) When a WRVIFWHOLE is received if we are the RP,
send a pim register stop to the FHR.

2) When a register was received we were sending
a join (S,G) towards the S, then a immediate prune (S,G)
followed by another join (S,G).  Just send the first join

3) Save whom we received the S,G register from so we
can use it later

4) Allow a join timer to restart itself instead
of causing a crash.

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>

pimd/pim_mroute.c

@@ -26,6 +26,7 @@
 #include "prefix.h"
 
 #include "pimd.h"
+#include "pim_rpf.h"
 #include "pim_mroute.h"
 #include "pim_oil.h"
 #include "pim_str.h"
@@ -345,6 +346,17 @@ pim_mroute_msg_wrvifwhole (int fd, struct interface *ifp, const char *buf)
   if (PIM_DEBUG_MROUTE)
     zlog_debug ("If channel: %p", ch);
 
+  up = pim_upstream_find (&sg);
+  if (up)
+    {
+      struct pim_nexthop source;
+      //No if channel, but upstream we are at the RP.
+      pim_nexthop_lookup (&source, up->upstream_register, NULL);
+      pim_register_stop_send(source.interface, &sg, up->upstream_register);
+      //Send S bit down the join.
+      return 0;
+    }
+
   up = pim_upstream_add (&sg, ifp);
 
   if (!up)

pimd/pim_register.c

@@ -44,7 +44,7 @@
 
 struct thread *send_test_packet_timer = NULL;
 
-static void
+void
 pim_register_stop_send (struct interface *ifp, struct prefix_sg *sg,
 			struct in_addr originator)
 {
@@ -321,6 +321,7 @@ pim_register_recv (struct interface *ifp,
       {
 	upstream = pim_upstream_add (&sg, ifp);
 
+        upstream->upstream_register = src_addr;
 	pim_rp_set_upstream_addr (&upstream->upstream_addr, sg.src, sg.grp);
 	pim_nexthop_lookup (&upstream->rpf.source_nexthop,
 			    upstream->upstream_addr, NULL);
@@ -328,7 +329,8 @@ pim_register_recv (struct interface *ifp,
 	upstream->sg.src = sg.src;
 	upstream->rpf.rpf_addr = upstream->rpf.source_nexthop.mrib_nexthop_addr;
 
-	pim_upstream_switch (upstream, PIM_UPSTREAM_PRUNE);
+	//pim_upstream_switch (upstream, PIM_UPSTREAM_PRUNE);
+	upstream->join_state = PIM_UPSTREAM_PRUNE;
 
       }
 

pimd/pim_register.h

@@ -43,5 +43,6 @@ int pim_register_recv (struct interface *ifp,
 		       uint8_t *tlv_buf, int tlv_buf_size);
 
 void pim_register_send (const uint8_t *buf, int buf_size, struct pim_rpf *rpg, int null_register);
+void pim_register_stop_send (struct interface *ifp, struct prefix_sg *sg, struct in_addr originator);
 
 #endif

pimd/pim_upstream.c

@@ -225,8 +225,7 @@ static void join_timer_start(struct pim_upstream *up)
 	       pim_str_sg_dump (&up->sg));
   }
 
-  zassert(!up->t_join_timer);
+  THREAD_OFF (up->t_join_timer);
-
   THREAD_TIMER_ON(master, up->t_join_timer,
 		  on_join_timer,
 		  up, qpim_t_periodic);

pimd/pim_upstream.h

@@ -90,6 +90,7 @@ struct pim_upstream {
   struct pim_upstream      *parent;
   int                      fhr;
   struct in_addr           upstream_addr;/* Who we are talking to */
+  struct in_addr           upstream_register; /*Who we received a register from*/
   struct prefix_sg         sg;           /* (S,G) group key */
   uint32_t                 flags;
   struct channel_oil      *channel_oil;