Get rid of some other uses of ethertype() for protocols that don't have

a trailer.

Clean up the NHRP dissector's handling of the protocol ID to fully
implement RFC 2332 (and mention that 2332 is the RFC for NHRP).  Don't
compute the checksum unless we have all the packet data, and don't use
the captured length as the actual packet length.  Check for an invalid
extension offset value.  Get rid of some unneeded
tvb_ensure_bytes_exist() calls.  Dissect - and set the columns -
regardless of whether we're building the protocol tree.  Mark the packet
in error reports as an error packet.

svn path=/trunk/; revision=28273

1 files changed, 20 insertions, 12 deletions

diff --git a/epan/dissectors/packet-null.c b/epan/dissectors/packet-null.c
index 095f2118bc..2a8eb4afb4 100644
--- a/epan/dissectors/packet-null.c
+++ b/epan/dissectors/packet-null.c
@@ -44,6 +44,7 @@
 #include <epan/aftypes.h>
 
 static dissector_table_t null_dissector_table;
+static dissector_table_t ethertype_dissector_table;
 
 /* protocols and header fields */
 static int proto_null = -1;
@@ -417,22 +418,25 @@ dissect_null(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 
     /*
      * The null header value must be greater than the IEEE 802.3 maximum
-     * frame length to be a valid Ethernet type; if it is, hand it
-     * to "ethertype()", otherwise treat it as a BSD AF_type (we wire
-     * in the values of the BSD AF_ types, because the values
-     * in the file will be BSD values, and the OS on which
-     * we're building this might not have the same values or
-     * might not have them defined at all; XXX - what if different
-     * BSD derivatives have different values?).
+     * frame length to be a valid Ethernet type; if it is, dissect it
+     * as one, otherwise treat it as a BSD AF_type (we wire in the values
+     * of the BSD AF_ types, because the values in the file will be BSD
+     * values, and the OS on which we're building this might not have the
+     * same values or might not have them defined at all; XXX - what if
+     * different BSD derivatives have different values?).
      */
     if (null_header > IEEE_802_3_MAX_LEN) {
       if (tree) {
         ti = proto_tree_add_item(tree, proto_null, tvb, 0, 4, FALSE);
         fh_tree = proto_item_add_subtree(ti, ett_null);
-      } else
-      	fh_tree = NULL;
-      ethertype((guint16) null_header, tvb, 4, pinfo, tree, fh_tree, hf_null_etype, -1,
-	0);
+        proto_tree_add_uint(fh_tree, hf_null_etype, tvb, 0, 4,
+          (guint16) null_header);
+      }
+
+      next_tvb = tvb_new_subset(tvb, 4, -1, -1);
+      if (!dissector_try_port(ethertype_dissector_table,
+            (guint16) null_header, next_tvb, pinfo, tree))
+	call_dissector(data_handle, next_tvb, pinfo, tree);
     } else {
       /* populate a tree in the second pane with the status of the link
          layer (ie none) */
@@ -485,10 +489,14 @@ proto_reg_handoff_null(void)
 	dissector_handle_t null_handle;
 
 	/*
-	 * Get a handle for the PPP-in-HDLC-like-framing dissector.
+	 * Get a handle for the PPP-in-HDLC-like-framing dissector and
+	 * the "I don't know what this is" dissector.
 	 */
 	ppp_hdlc_handle = find_dissector("ppp_hdlc");
 	data_handle = find_dissector("data");
+
+	ethertype_dissector_table = find_dissector_table("ethertype");
+
 	null_handle = create_dissector_handle(dissect_null, proto_null);
 	dissector_add("wtap_encap", WTAP_ENCAP_NULL, null_handle);
 }