ospf6d: make some old sizing checks assertions

As long as ospf6_packet_examin() is now the single checkpoint for
received packets, most of the old checks performed elsewhere can
be converted into assert() constructs. Malformed input data at
respective points can be attributed solely to a programming error,
not a malformed packet.

* ospf6_message.c
  * ospf6_hello_print()
  * ospf6_dbdesc_print()
  * ospf6_lsreq_print()
  * ospf6_lsupdate_print()
  * ospf6_lsack_print()
  * ospf6_hello_recv()
  * ospf6_dbdesc_recv_master()
  * ospf6_dbdesc_recv_slave()
  * ospf6_lsreq_recv()
  * ospf6_lsupdate_recv()
  * ospf6_lsupdate_recv()
  * ospf6_lsack_recv()
  * ospf6_receive()

1 files changed, 13 insertions, 90 deletions

diff --git a/ospf6d/ospf6_message.c b/ospf6d/ospf6_message.c
index 42521a2d..0cd90360 100644
--- a/ospf6d/ospf6_message.c
+++ b/ospf6d/ospf6_message.c
@@ -128,8 +128,7 @@ ospf6_hello_print (struct ospf6_header *oh)
       zlog_debug ("    Neighbor: %s", neighbor);
     }
 
-  if (p != OSPF6_MESSAGE_END (oh))
-    zlog_debug ("Trailing garbage exists");
+  assert (p == OSPF6_MESSAGE_END (oh));
 }
 
 void
@@ -161,8 +160,7 @@ ospf6_dbdesc_print (struct ospf6_header *oh)
        p += sizeof (struct ospf6_lsa_header))
     ospf6_lsa_header_print_raw ((struct ospf6_lsa_header *) p);
 
-  if (p != OSPF6_MESSAGE_END (oh))
-    zlog_debug ("Trailing garbage exists");
+  assert (p == OSPF6_MESSAGE_END (oh));
 }
 
 void
@@ -185,8 +183,7 @@ ospf6_lsreq_print (struct ospf6_header *oh)
                  ospf6_lstype_name (e->type), id, adv_router);
     }
 
-  if (p != OSPF6_MESSAGE_END (oh))
-    zlog_debug ("Trailing garbage exists");
+  assert (p == OSPF6_MESSAGE_END (oh));
 }
 
 void
@@ -211,35 +208,9 @@ ospf6_lsupdate_print (struct ospf6_header *oh)
        p += OSPF6_LSA_SIZE (p))
     {
       ospf6_lsa_header_print_raw ((struct ospf6_lsa_header *) p);
-      if (OSPF6_LSA_SIZE (p) < sizeof (struct ospf6_lsa_header))
-        {
-          zlog_debug ("    Malformed LSA length, quit printing");
-          break;
-        }
     }
 
-  if (p != OSPF6_MESSAGE_END (oh))
-    {
-      char buf[32];
-
-      int num = 0;
-      memset (buf, 0, sizeof (buf));
-
-      zlog_debug ("    Trailing garbage exists");
-      while (p < OSPF6_MESSAGE_END (oh))
-        {
-          snprintf (buf, sizeof (buf), "%s %2x", buf, *p++);
-          num++;
-          if (num == 8)
-            {
-              zlog_debug ("    %s", buf);
-              memset (buf, 0, sizeof (buf));
-              num = 0;
-            }
-        }
-      if (num)
-        zlog_debug ("    %s", buf);
-    }
+  assert (p == OSPF6_MESSAGE_END (oh));
 }
 
 void
@@ -255,8 +226,7 @@ ospf6_lsack_print (struct ospf6_header *oh)
        p += sizeof (struct ospf6_lsa_header))
     ospf6_lsa_header_print_raw ((struct ospf6_lsa_header *) p);
 
-  if (p != OSPF6_MESSAGE_END (oh))
-    zlog_debug ("Trailing garbage exists");
+  assert (p == OSPF6_MESSAGE_END (oh));
 }
 
 static void
@@ -323,11 +293,7 @@ ospf6_hello_recv (struct in6_addr *src, struct in6_addr *dst,
         twoway++;
     }
 
-  if (p != OSPF6_MESSAGE_END (oh))
-    {
-      if (IS_OSPF6_DEBUG_MESSAGE (oh->type, RECV))
-        zlog_debug ("Trailing garbage ignored");
-    }
+  assert (p == OSPF6_MESSAGE_END (oh));
 
   /* RouterPriority check */
   if (on->priority != hello->priority)
@@ -560,11 +526,7 @@ ospf6_dbdesc_recv_master (struct ospf6_header *oh,
         }
     }
 
-  if (p != OSPF6_MESSAGE_END (oh))
-    {
-      if (IS_OSPF6_DEBUG_MESSAGE (oh->type, RECV))
-        zlog_debug ("Trailing garbage ignored");
-    }
+  assert (p == OSPF6_MESSAGE_END (oh));
 
   /* Increment sequence number */
   on->dbdesc_seqnum ++;
@@ -772,11 +734,7 @@ ospf6_dbdesc_recv_slave (struct ospf6_header *oh,
         ospf6_lsa_delete (his);
     }
 
-  if (p != OSPF6_MESSAGE_END (oh))
-    {
-      if (IS_OSPF6_DEBUG_MESSAGE (oh->type, RECV))
-        zlog_debug ("Trailing garbage ignored");
-    }
+  assert (p == OSPF6_MESSAGE_END (oh));
 
   /* Set sequence number to Master's */
   on->dbdesc_seqnum = ntohl (dbdesc->seqnum);
@@ -912,11 +870,7 @@ ospf6_lsreq_recv (struct in6_addr *src, struct in6_addr *dst,
       ospf6_lsdb_add (ospf6_lsa_copy (lsa), on->lsupdate_list);
     }
 
-  if (p != OSPF6_MESSAGE_END (oh))
-    {
-      if (IS_OSPF6_DEBUG_MESSAGE (oh->type, RECV))
-        zlog_debug ("Trailing garbage ignored");
-    }
+  assert (p == OSPF6_MESSAGE_END (oh));
 
   /* schedule send lsupdate */
   THREAD_OFF (on->thread_send_lsupdate);
@@ -1357,7 +1311,6 @@ ospf6_lsupdate_recv (struct in6_addr *src, struct in6_addr *dst,
 {
   struct ospf6_neighbor *on;
   struct ospf6_lsupdate *lsupdate;
-  unsigned long num;
   char *p;
 
   on = ospf6_neighbor_lookup (oh->router_id, oi);
@@ -1380,37 +1333,16 @@ ospf6_lsupdate_recv (struct in6_addr *src, struct in6_addr *dst,
   lsupdate = (struct ospf6_lsupdate *)
     ((caddr_t) oh + sizeof (struct ospf6_header));
 
-  num = ntohl (lsupdate->lsa_number);
-
   /* Process LSAs */
   for (p = (char *) ((caddr_t) lsupdate + sizeof (struct ospf6_lsupdate));
        p < OSPF6_MESSAGE_END (oh) &&
        p + OSPF6_LSA_SIZE (p) <= OSPF6_MESSAGE_END (oh);
        p += OSPF6_LSA_SIZE (p))
     {
-      if (num == 0)
-        break;
-      if (OSPF6_LSA_SIZE (p) < sizeof (struct ospf6_lsa_header))
-        {
-          if (IS_OSPF6_DEBUG_MESSAGE (oh->type, RECV))
-            zlog_debug ("Malformed LSA length, quit processing");
-          break;
-        }
-
       ospf6_receive_lsa (on, (struct ospf6_lsa_header *) p);
-      num--;
     }
 
-  if (num != 0)
-    {
-      if (IS_OSPF6_DEBUG_MESSAGE (oh->type, RECV))
-        zlog_debug ("Malformed LSA number or LSA length");
-    }
-  if (p != OSPF6_MESSAGE_END (oh))
-    {
-      if (IS_OSPF6_DEBUG_MESSAGE (oh->type, RECV))
-        zlog_debug ("Trailing garbage ignored");
-    }
+  assert (p == OSPF6_MESSAGE_END (oh));
 
   /* RFC2328 Section 10.9: When the neighbor responds to these requests
      with the proper Link State Update packet(s), the Link state request
@@ -1526,11 +1458,7 @@ ospf6_lsack_recv (struct in6_addr *src, struct in6_addr *dst,
       ospf6_lsa_delete (his);
     }
 
-  if (p != OSPF6_MESSAGE_END (oh))
-    {
-      if (IS_OSPF6_DEBUG_MESSAGE (oh->type, RECV))
-        zlog_debug ("Trailing garbage ignored");
-    }
+  assert (p == OSPF6_MESSAGE_END (oh));
 }
 
 static u_char *recvbuf = NULL;
@@ -1652,8 +1580,6 @@ ospf6_receive (struct thread *thread)
                  OSPF6_MESSAGE_TYPE_NAME (oh->type), oi->interface->name);
       zlog_debug ("    src: %s", srcname);
       zlog_debug ("    dst: %s", dstname);
-      if (len != ntohs (oh->length))
-        zlog_debug ("Message length does not match actually received: %d", len);
 
       switch (oh->type)
         {
@@ -1673,8 +1599,7 @@ ospf6_receive (struct thread *thread)
             ospf6_lsack_print (oh);
             break;
           default:
-            zlog_debug ("Unknown message");
-            break;
+            assert (0);
         }
     }
 
@@ -1701,9 +1626,7 @@ ospf6_receive (struct thread *thread)
         break;
 
       default:
-        if (IS_OSPF6_DEBUG_MESSAGE (OSPF6_MESSAGE_TYPE_UNKNOWN, RECV))
-          zlog_debug ("Unknown message");
-        break;
+        assert (0);
     }
 
   return 0;