Make a "tcp_dissect_pdus()" with the standard loop for a TCP segment,

extracting PDUs from it and possibly doing reassembly.  Make the COPS,
DNS, DSI, Gryphon, and SCCP dissectors use it.

Add "set_actual_length()", "tcp_dissect_pdus()",
"decode_boolean_bitfield()", "decode_numeric_bitfield()", and
"decode_enumerated_bitfield()" to the list of routines available to
dissectors on platforms where routines in the main program aren't
available to dynamically-loaded code.

Declare routines in "to_str.h" as "extern"; as I remember, that's
necessary to allow the "decode_XXX_bitfield()" routines declared therein
to be made available to plugins as per the above.

Note that new exported routines should be added to the end of the table
if that's the only change being made to the table.

Create a new "plugin_api_decls.h" header file, used to declare both the
"p_" variables and the "p_" structure members in the routine-exporting
mechanism; this reduces the number of places you have to change to
change the list of exported routines.

svn path=/trunk/; revision=5394

1 files changed, 13 insertions, 110 deletions

diff --git a/packet-cops.c b/packet-cops.c
index 6848218862..a664e9818f 100644
--- a/packet-cops.c
+++ b/packet-cops.c
@@ -4,7 +4,7 @@
  *
  * Copyright 2000, Heikki Vatiainen <hessu@cs.tut.fi>
  *
- * $Id: packet-cops.c,v 1.29 2002/04/28 00:43:16 guy Exp $
+ * $Id: packet-cops.c,v 1.30 2002/05/05 00:16:32 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@ethereal.com>
@@ -37,7 +37,7 @@
 #include <glib.h>
 #include <epan/packet.h>
 #include "packet-ipv6.h"
-#include "packet-frame.h"
+#include "packet-tcp.h"
 
 #include "asn1.h"
 #include "format-oid.h"
@@ -426,6 +426,7 @@ static gint ett_cops_pdp = -1;
 
 void proto_reg_handoff_cops(void);
 
+static guint get_cops_pdu_len(tvbuff_t *tvb, int offset);
 static void dissect_cops_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree);
 
 static int dissect_cops_object(tvbuff_t *tvb, guint32 offset, proto_tree *tree);
@@ -440,115 +441,17 @@ static int dissect_cops_pr_object_data(tvbuff_t *tvb, guint32 offset, proto_tree
 static void
 dissect_cops(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 {
-        volatile int offset = 0;
-	int length_remaining;
-	guint32 msg_len;
-	int length;
-	tvbuff_t *next_tvb;
-
-	while (tvb_reported_length_remaining(tvb, offset) != 0) {
-		length_remaining = tvb_length_remaining(tvb, offset);
-		if (length_remaining == -1)
-			THROW(BoundsError);
-
-		/*
-		 * Can we do reassembly?
-		 */
-		if (cops_desegment && pinfo->can_desegment) {
-			/*
-			 * Yes - is the COPS header split across segment
-			 * boundaries?
-			 */
-			if (length_remaining < 8) {
-				/*
-				 * Yes.  Tell the TCP dissector where
-				 * the data for this message starts in
-				 * the data it handed us, and how many
-				 * more bytes we need, and return.
-				 */
-				pinfo->desegment_offset = offset;
-				pinfo->desegment_len = 8 - length_remaining;
-				return;
-			}
-		}
-
-		/*
-		 * Get the length of the COPS message.
-		 */
-		msg_len = tvb_get_ntohl(tvb, offset + 4);
-
-		/*
-		 * Can we do reassembly?
-		 */
-		if (cops_desegment && pinfo->can_desegment) {
-			/*
-			 * Yes - is the DNS packet split across segment
-			 * boundaries?
-			 */
-			if ((guint32)length_remaining < msg_len) {
-				/*
-				 * Yes.  Tell the TCP dissector where
-				 * the data for this message starts in
-				 * the data it handed us, and how many
-				 * more bytes we need, and return.
-				 */
-				pinfo->desegment_offset = offset;
-				pinfo->desegment_len =
-				    msg_len - length_remaining;
-				return;
-			}
-		}
-
-		/*
-		 * Construct a tvbuff containing the amount of the payload
-		 * we have available.  Make its reported length the
-		 * amount of data in the COPS packet.
-		 *
-		 * XXX - if reassembly isn't enabled. the subdissector
-		 * will throw a BoundsError exception, rather than a
-		 * ReportedBoundsError exception.  We really want
-		 * a tvbuff where the length is "length", the reported
-		 * length is "plen + 2", and the "if the snapshot length
-		 * were infinite" length were the minimum of the
-		 * reported length of the tvbuff handed to us and "plen+2",
-		 * with a new type of exception thrown if the offset is
-		 * within the reported length but beyond that third length,
-		 * with that exception getting the "Unreassembled Packet"
-		 * error.
-		 */
-		length = length_remaining;
-		if ((guint32)length > msg_len)
-			length = msg_len;
-		next_tvb = tvb_new_subset(tvb, offset, length, msg_len);
-
-		/*
-		 * Dissect the COPS packet.
-		 *
-		 * Catch the ReportedBoundsError exception; if this
-		 * particular message happens to get a ReportedBoundsError
-		 * exception, that doesn't mean that we should stop
-		 * dissecting COPS messages within this frame or chunk
-		 * of reassembled data.
-		 *
-		 * If it gets a BoundsError, we can stop, as there's nothing
-		 * more to see, so we just re-throw it.
-		 */
-		TRY {
-			dissect_cops_pdu(next_tvb, pinfo, tree);
-		}
-		CATCH(BoundsError) {
-			RETHROW;
-		}
-		CATCH(ReportedBoundsError) {
-			show_reported_bounds_error(tvb, pinfo, tree);
-		}
-		ENDTRY;
+	tcp_dissect_pdus(tvb, pinfo, tree, cops_desegment, 8,
+	    get_cops_pdu_len, dissect_cops_pdu);
+}
 
-		/*
-		 * Skip the COPS packet.
-		 */
-		offset += msg_len;
-	}
+static guint
+get_cops_pdu_len(tvbuff_t *tvb, int offset)
+{
+	/*
+	 * Get the length of the COPS message.
+	 */
+	return tvb_get_ntohl(tvb, offset + 4);
 }
 
 static void