pimd: Add packed data structures for building j/p messages

Switch pim over to using packed data structures for building
Join/Prune messages to be sent.

This is a pre-cursor to the ability to handle the ability
to aggregate Join/Prune messages together.

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

1 files changed, 69 insertions, 97 deletions

diff --git a/pimd/pim_msg.c b/pimd/pim_msg.c
index 4378ac99f7..3a8ccb887e 100644
--- a/pimd/pim_msg.c
+++ b/pimd/pim_msg.c
@@ -161,25 +161,16 @@ pim_msg_addr_encode_ipv4_source(uint8_t *buf,
  */
 int
 pim_msg_join_prune_encode (uint8_t *buf, size_t buf_size, int is_join,
-			   struct pim_upstream *up,
-			   struct in_addr upstream, int holdtime)
+                           struct pim_upstream *up,
+                           struct in_addr upstream, int holdtime)
 {
-  uint8_t *pim_msg = buf;
-  uint8_t *pim_msg_curr = buf + PIM_MSG_HEADER_LEN;
-  uint8_t *end = buf + buf_size;
-  uint16_t *prunes = NULL;
-  uint16_t *joins = NULL;
+  struct pim_jp *msg = (struct pim_jp *)buf;
   struct in_addr stosend;
   uint8_t bits;
-  int remain;
-  size_t min_len = PIM_MSG_HEADER_LEN + PIM_JP_GROUP_HEADER_SIZE +
-    PIM_ENCODED_IPV4_SOURCE_SIZE;   // Only 1 source
 
-  assert(buf_size > min_len);
+  assert(buf_size > sizeof (struct pim_jp));
 
-  remain = end - pim_msg_curr;
-  pim_msg_curr = pim_msg_addr_encode_ipv4_ucast (pim_msg_curr, upstream);
-  if (!pim_msg_curr) {
+  if (!pim_msg_addr_encode_ipv4_ucast ((uint8_t *)&msg->addr, upstream)) {
     char dst_str[INET_ADDRSTRLEN];
     pim_inet4_dump("<dst?>", upstream, dst_str, sizeof(dst_str));
     zlog_warn("%s: failure encoding destination address %s",
@@ -187,40 +178,22 @@ pim_msg_join_prune_encode (uint8_t *buf, size_t buf_size, int is_join,
     return -3;
   }
 
-  *pim_msg_curr = 0; /* reserved */
-  ++pim_msg_curr;
-  *pim_msg_curr = 1; /* number of groups */
-  ++pim_msg_curr;
+  msg->reserved   = 0;
+  msg->num_groups = 1;
+  msg->holdtime   = htons(holdtime);
 
-  *((uint16_t *) pim_msg_curr) = htons(holdtime);
-  ++pim_msg_curr;
-  ++pim_msg_curr;
-
-  remain = end - pim_msg_curr;
-  pim_msg_curr = pim_msg_addr_encode_ipv4_group (pim_msg_curr, up->sg.grp);
-  if (!pim_msg_curr) {
+  if (!pim_msg_addr_encode_ipv4_group ((uint8_t *)&msg->groups[0].g, up->sg.grp)) {
     char group_str[INET_ADDRSTRLEN];
     pim_inet4_dump("<grp?>", up->sg.grp, group_str, sizeof(group_str));
     zlog_warn("%s: failure encoding group address %s",
-	      __PRETTY_FUNCTION__, group_str);
+              __PRETTY_FUNCTION__, group_str);
     return -5;
   }
 
-  remain = end - pim_msg_curr;
-
-  /* number of joined sources */
-  joins = (uint16_t *)pim_msg_curr;
-  *joins = htons(is_join ? 1 : 0);
-  ++pim_msg_curr;
-  ++pim_msg_curr;
+  /* number of joined/pruned sources */
+  msg->groups[0].joins  = htons(is_join ? 1 : 0);
+  msg->groups[0].prunes = htons(is_join ? 0 : 1);
 
-  /* number of pruned sources */
-  prunes = (uint16_t *)pim_msg_curr;
-  *prunes = htons(is_join ? 0 : 1);
-  ++pim_msg_curr;
-  ++pim_msg_curr;
-
-  remain = end - pim_msg_curr;
   if (up->sg.src.s_addr == INADDR_ANY)
     {
       struct pim_rpf *rpf = pim_rp_g (up->sg.grp);
@@ -232,15 +205,14 @@ pim_msg_join_prune_encode (uint8_t *buf, size_t buf_size, int is_join,
       bits = PIM_ENCODE_SPARSE_BIT;
       stosend = up->sg.src;
     }
-  pim_msg_curr = pim_msg_addr_encode_ipv4_source (pim_msg_curr, stosend, bits);
-  if (!pim_msg_curr) {
+
+  if (!pim_msg_addr_encode_ipv4_source ((uint8_t *)&msg->groups[0].s[0], stosend, bits)) {
     char source_str[INET_ADDRSTRLEN];
     pim_inet4_dump("<src?>", up->sg.src, source_str, sizeof(source_str));
     zlog_warn("%s: failure encoding source address %s",
-	      __PRETTY_FUNCTION__, source_str);
+              __PRETTY_FUNCTION__, source_str);
     return -7;
   }
-  remain = pim_msg_curr - pim_msg;
 
   /*
    * This is not implemented correctly at this point in time
@@ -254,61 +226,61 @@ pim_msg_join_prune_encode (uint8_t *buf, size_t buf_size, int is_join,
       int send_prune = 0;
 
       zlog_debug ("%s: Considering (%s) children for (S,G,rpt) prune",
-		  __PRETTY_FUNCTION__, up->sg_str);
+                  __PRETTY_FUNCTION__, up->sg_str);
       for (ALL_LIST_ELEMENTS_RO (up->sources, up_node, child))
-	{
-	  if (child->sptbit == PIM_UPSTREAM_SPTBIT_TRUE)
-	    {
-	      if (!pim_rpf_is_same(&up->rpf, &child->rpf))
-		{
-		  send_prune = 1;
-		  if (PIM_DEBUG_PIM_PACKETS)
-		    zlog_debug ("%s: SPT Bit and RPF'(%s) != RPF'(S,G): Add Prune (%s,rpt) to compound message",
-				__PRETTY_FUNCTION__, up->sg_str, child->sg_str);
-		}
-	      else
-		if (PIM_DEBUG_PIM_PACKETS)
-		  zlog_debug ("%s: SPT Bit and RPF'(%s) == RPF'(S,G): Not adding Prune for (%s,rpt)",
-			      __PRETTY_FUNCTION__, up->sg_str, child->sg_str);
-	    }
-	  else if (pim_upstream_is_sg_rpt (child))
-	    {
-	      if (pim_upstream_empty_inherited_olist (child))
-		{
-		  send_prune = 1;
-		  if (PIM_DEBUG_PIM_PACKETS)
-		    zlog_debug ("%s: inherited_olist(%s,rpt) is NULL, Add Prune to compound message",
-				__PRETTY_FUNCTION__, child->sg_str);
-		}
-	      else if (!pim_rpf_is_same (&up->rpf, &child->rpf))
-		{
-		  send_prune = 1;
-		  if (PIM_DEBUG_PIM_PACKETS)
-		    zlog_debug ("%s: RPF'(%s) != RPF'(%s,rpt), Add Prune to compound message",
-				__PRETTY_FUNCTION__, up->sg_str, child->sg_str);
-		}
-	      else
-		if (PIM_DEBUG_PIM_PACKETS)
-		  zlog_debug ("%s: RPF'(%s) == RPF'(%s,rpt), Do not add Prune to compound message",
-			      __PRETTY_FUNCTION__, up->sg_str, child->sg_str);
-	    }
-	  else
-	    if (PIM_DEBUG_PIM_PACKETS)
-	      zlog_debug ("%s: SPT bit is not set for (%s)",
-			  __PRETTY_FUNCTION__, child->sg_str);
-	  if (send_prune)
-	    {
-	      pim_msg_curr = pim_msg_addr_encode_ipv4_source (pim_msg_curr, remain,
-							      child->sg.src,
-							      PIM_ENCODE_SPARSE_BIT | PIM_ENCODE_RPT_BIT);
-	      remain = pim_msg_curr - pim_msg;
-	      *prunes = htons(ntohs(*prunes) + 1);
-	      send_prune = 0;
-	    }
-	}
+        {
+          if (child->sptbit == PIM_UPSTREAM_SPTBIT_TRUE)
+            {
+              if (!pim_rpf_is_same(&up->rpf, &child->rpf))
+                {
+                  send_prune = 1;
+                  if (PIM_DEBUG_PIM_PACKETS)
+                    zlog_debug ("%s: SPT Bit and RPF'(%s) != RPF'(S,G): Add Prune (%s,rpt) to compound message",
+                                __PRETTY_FUNCTION__, up->sg_str, child->sg_str);
+                }
+              else
+                if (PIM_DEBUG_PIM_PACKETS)
+                  zlog_debug ("%s: SPT Bit and RPF'(%s) == RPF'(S,G): Not adding Prune for (%s,rpt)",
+                              __PRETTY_FUNCTION__, up->sg_str, child->sg_str);
+            }
+          else if (pim_upstream_is_sg_rpt (child))
+            {
+              if (pim_upstream_empty_inherited_olist (child))
+                {
+                  send_prune = 1;
+                  if (PIM_DEBUG_PIM_PACKETS)
+                    zlog_debug ("%s: inherited_olist(%s,rpt) is NULL, Add Prune to compound message",
+                                __PRETTY_FUNCTION__, child->sg_str);
+                }
+              else if (!pim_rpf_is_same (&up->rpf, &child->rpf))
+                {
+                  send_prune = 1;
+                  if (PIM_DEBUG_PIM_PACKETS)
+                    zlog_debug ("%s: RPF'(%s) != RPF'(%s,rpt), Add Prune to compound message",
+                                __PRETTY_FUNCTION__, up->sg_str, child->sg_str);
+                }
+              else
+                if (PIM_DEBUG_PIM_PACKETS)
+                  zlog_debug ("%s: RPF'(%s) == RPF'(%s,rpt), Do not add Prune to compound message",
+                              __PRETTY_FUNCTION__, up->sg_str, child->sg_str);
+            }
+          else
+            if (PIM_DEBUG_PIM_PACKETS)
+              zlog_debug ("%s: SPT bit is not set for (%s)",
+                          __PRETTY_FUNCTION__, child->sg_str);
+          if (send_prune)
+            {
+              pim_msg_curr = pim_msg_addr_encode_ipv4_source (pim_msg_curr, remain,
+                                                              child->sg.src,
+                                                              PIM_ENCODE_SPARSE_BIT | PIM_ENCODE_RPT_BIT);
+              remain = pim_msg_curr - pim_msg;
+              *prunes = htons(ntohs(*prunes) + 1);
+              send_prune = 0;
+            }
+        }
     }
 #endif
-  pim_msg_build_header (pim_msg, remain, PIM_MSG_TYPE_JOIN_PRUNE);
+  pim_msg_build_header (buf, sizeof (struct pim_jp), PIM_MSG_TYPE_JOIN_PRUNE);
 
-  return remain;
+  return sizeof (struct pim_jp);
 }