If we get an exception when dissecting a packet, append "[Short Frame]"

or "[Malformed Frame]" to the Info column.

Make some dissectors set the Protocol column and clear the Info column
before fetching anything from the tvbuff they were handed, so that if
the frame is short or malformed, it'll be marked as being the right
top-level protocol, and the Info column won't have cruft left over from
the previous protocol.

svn path=/trunk/; revision=2800

1 files changed, 14 insertions, 7 deletions

diff --git a/packet-ip.c b/packet-ip.c
index 888d1b2683..5ed582f86c 100644
--- a/packet-ip.c
+++ b/packet-ip.c
@@ -1,7 +1,7 @@
 /* packet-ip.c
  * Routines for IP and miscellaneous IP protocol packet disassembly
  *
- * $Id: packet-ip.c,v 1.114 2000/12/14 21:44:01 guy Exp $
+ * $Id: packet-ip.c,v 1.115 2000/12/29 04:16:57 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@zing.org>
@@ -797,6 +797,11 @@ dissect_ip(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 
   pinfo->current_proto = "IP";
 
+  if (check_col(pinfo->fd, COL_PROTOCOL))
+    col_set_str(pinfo->fd, COL_PROTOCOL, "IP");
+  if (check_col(pinfo->fd, COL_INFO))
+    col_clear(pinfo->fd, COL_INFO);
+
   /* Avoids alignment problems on many architectures. */
   tvb_memcpy(tvb, (guint8 *)&iph, offset, sizeof(e_ip));
   iph.ip_len = ntohs(iph.ip_len);
@@ -922,8 +927,6 @@ dissect_ip(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
   nxt = iph.ip_p;
   if (iph.ip_off & IP_OFFSET) {
     /* fragmented */
-    if (check_col(pinfo->fd, COL_PROTOCOL))
-      col_set_str(pinfo->fd, COL_PROTOCOL, "IP");
     if (check_col(pinfo->fd, COL_INFO))
       col_add_fstr(pinfo->fd, COL_INFO, "Fragmented IP protocol (proto=%s 0x%02x, off=%u)",
 	ipprotostr(iph.ip_p), iph.ip_p, (iph.ip_off & IP_OFFSET) * 8);
@@ -950,8 +953,6 @@ dissect_ip(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
   next_tvb = tvb_new_subset(tvb, offset, -1, -1);
   if (!dissector_try_port(ip_dissector_table, nxt, next_tvb, pinfo, tree)) {
     /* Unknown protocol */
-    if (check_col(pinfo->fd, COL_PROTOCOL))
-      col_set_str(pinfo->fd, COL_PROTOCOL, "IP");
     if (check_col(pinfo->fd, COL_INFO))
       col_add_fstr(pinfo->fd, COL_INFO, "%s (0x%02x)", ipprotostr(iph.ip_p), iph.ip_p);
     dissect_data(next_tvb, 0, pinfo, tree);
@@ -1012,6 +1013,11 @@ dissect_icmp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 
   pinfo->current_proto = "ICMP";
 
+  if (check_col(pinfo->fd, COL_PROTOCOL))
+    col_set_str(pinfo->fd, COL_PROTOCOL, "ICMP");
+  if (check_col(pinfo->fd, COL_INFO))
+    col_clear(pinfo->fd, COL_INFO);
+
   /* To do: check for runts, errs, etc. */
   icmp_type = tvb_get_guint8(tvb, 0);
   icmp_code = tvb_get_guint8(tvb, 1);
@@ -1087,8 +1093,6 @@ dissect_icmp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
       strcpy(type_str, "Unknown ICMP (obsolete or malformed?)");
   }
 
-  if (check_col(pinfo->fd, COL_PROTOCOL))
-    col_set_str(pinfo->fd, COL_PROTOCOL, "ICMP");
   if (check_col(pinfo->fd, COL_INFO))
     col_add_str(pinfo->fd, COL_INFO, type_str);
 
@@ -1236,8 +1240,11 @@ dissect_igmp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
   CHECK_DISPLAY_AS_DATA(proto_igmp, tvb, pinfo, tree);
 
   pinfo->current_proto = "IGMP";
+
   if (check_col(pinfo->fd, COL_PROTOCOL))
     col_set_str(pinfo->fd, COL_PROTOCOL, "IGMP");
+  if (check_col(pinfo->fd, COL_INFO))
+    col_clear(pinfo->fd, COL_INFO);
 
   /* Avoids alignment problems on many architectures. */
   memcpy(&ih, tvb_get_ptr(tvb, 0, sizeof(e_igmp)), sizeof(e_igmp));