pimd: Refactor pim message receive

We were using a variety of techniques to handle
incoming pim packets.  Refactor to use a switch
statement to handle the incoming packets.

Also add the ability to notice that we are getting
a register stop.

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

3 files changed, 52 insertions, 47 deletions

diff --git a/pimd/pim_pim.c b/pimd/pim_pim.c
index c1b9e04e23..f0db822cb4 100644
--- a/pimd/pim_pim.c
+++ b/pimd/pim_pim.c
@@ -208,60 +208,57 @@ int pim_pim_packet(struct interface *ifp, uint8_t *buf, size_t len)
 	       pim_version, pim_type, pim_msg_len, checksum);
   }
 
-  if (pim_type == PIM_MSG_TYPE_REG_STOP  ||
-      pim_type == PIM_MSG_TYPE_BOOTSTRAP ||
-      pim_type == PIM_MSG_TYPE_GRAFT     ||
-      pim_type == PIM_MSG_TYPE_GRAFT_ACK ||
-      pim_type == PIM_MSG_TYPE_CANDIDATE)
+  switch (pim_type)
     {
+    case PIM_MSG_TYPE_HELLO:
+      return pim_hello_recv (ifp,
+			     ip_hdr->ip_src,
+			     pim_msg + PIM_MSG_HEADER_LEN,
+			     pim_msg_len - PIM_MSG_HEADER_LEN);
+      break;
+    case PIM_MSG_TYPE_REGISTER:
+      return pim_register_recv (ifp,
+				ip_hdr->ip_dst,
+				ip_hdr->ip_src,
+				pim_msg + PIM_MSG_HEADER_LEN,
+				pim_msg_len - PIM_MSG_HEADER_LEN);
+      break;
+    case PIM_MSG_TYPE_REG_STOP:
+      return pim_register_stop_recv ();
+      break;
+    case PIM_MSG_TYPE_JOIN_PRUNE:
+      neigh = pim_neighbor_find(ifp, ip_hdr->ip_src);
+      if (!neigh) {
+	zlog_warn("%s %s: non-hello PIM message type=%d from non-neighbor %s on %s",
+		  __FILE__, __PRETTY_FUNCTION__,
+		  pim_type, src_str, ifp->name);
+	return -1;
+      }
+      return pim_joinprune_recv(ifp, neigh,
+				ip_hdr->ip_src,
+				pim_msg + PIM_MSG_HEADER_LEN,
+				pim_msg_len - PIM_MSG_HEADER_LEN);
+      break;
+    case PIM_MSG_TYPE_ASSERT:
+      neigh = pim_neighbor_find(ifp, ip_hdr->ip_src);
+      if (!neigh) {
+	zlog_warn("%s %s: non-hello PIM message type=%d from non-neighbor %s on %s",
+		  __FILE__, __PRETTY_FUNCTION__,
+		  pim_type, src_str, ifp->name);
+	return -1;
+      }
+      return pim_assert_recv(ifp, neigh,
+			     ip_hdr->ip_src,
+			     pim_msg + PIM_MSG_HEADER_LEN,
+			     pim_msg_len - PIM_MSG_HEADER_LEN);
+      break;
+    default:
       if (PIM_DEBUG_PIM_PACKETS) {
 	zlog_debug("Recv PIM packet type %d which is not currently understood",
 		   pim_type);
       }
       return -1;
     }
-
-  if (pim_type == PIM_MSG_TYPE_HELLO) {
-    return pim_hello_recv(ifp,
-			  ip_hdr->ip_src,
-			  pim_msg + PIM_MSG_HEADER_LEN,
-			  pim_msg_len - PIM_MSG_HEADER_LEN);
-  } else if (pim_type == PIM_MSG_TYPE_REGISTER) {
-    return pim_register_recv(ifp,
-			     ip_hdr->ip_dst,
-			     ip_hdr->ip_src,
-			     pim_msg + PIM_MSG_HEADER_LEN,
-			     pim_msg_len - PIM_MSG_HEADER_LEN);
-  }
-
-  neigh = pim_neighbor_find(ifp, ip_hdr->ip_src);
-  if (!neigh) {
-    zlog_warn("%s %s: non-hello PIM message type=%d from non-neighbor %s on %s",
-	      __FILE__, __PRETTY_FUNCTION__,
-	      pim_type, src_str, ifp->name);
-    return -1;
-  }
-
-  switch (pim_type) {
-  case PIM_MSG_TYPE_JOIN_PRUNE:
-    return pim_joinprune_recv(ifp, neigh,
-			      ip_hdr->ip_src,
-			      pim_msg + PIM_MSG_HEADER_LEN,
-			      pim_msg_len - PIM_MSG_HEADER_LEN);
-    break;
-  case PIM_MSG_TYPE_ASSERT:
-    return pim_assert_recv(ifp, neigh,
-			   ip_hdr->ip_src,
-			   pim_msg + PIM_MSG_HEADER_LEN,
-			   pim_msg_len - PIM_MSG_HEADER_LEN);
-    break;
-  default:
-    zlog_warn("%s %s: unsupported PIM message type=%d from %s on %s",
-	      __FILE__, __PRETTY_FUNCTION__,
-	      pim_type, src_str, ifp->name);
-    break;
-  }
-
   return -1;
 }
 
diff --git a/pimd/pim_register.c b/pimd/pim_register.c
index 233db88d3e..a3e63f0285 100644
--- a/pimd/pim_register.c
+++ b/pimd/pim_register.c
@@ -111,6 +111,13 @@ pim_register_stop_send (struct interface *ifp, struct in_addr source,
     }
 }
 
+int
+pim_register_stop_recv (void)
+{
+  zlog_debug ("Received Register Stop");
+  return 0;
+}
+
 void
 pim_register_send (const struct ip *ip_hdr, struct pim_rpf *rpg)
 {
diff --git a/pimd/pim_register.h b/pimd/pim_register.h
index 039c0006e0..4749480b9d 100644
--- a/pimd/pim_register.h
+++ b/pimd/pim_register.h
@@ -35,6 +35,7 @@ void pim_register_send_test_packet_start (struct in_addr source,
 					  struct in_addr group,
 					  uint32_t pps);
 
+int pim_register_stop_recv (void);
 int pim_register_recv (struct interface *ifp,
 		       struct in_addr dest_addr,
 		       struct in_addr src_addr,