From Florian Lohoff via http://bugs.wireshark.org/bugzilla/show_bug.cgi?id=2320 : A new (heuristic) dissector for the RedBack Lawful Intercept Packet header.

svn path=/trunk/; revision=24579

1 files changed, 259 insertions, 0 deletions

diff --git a/epan/dissectors/packet-redbackli.c b/epan/dissectors/packet-redbackli.c
new file mode 100644
index 0000000000..9745c33294
--- /dev/null
+++ b/epan/dissectors/packet-redbackli.c
@@ -0,0 +1,259 @@
+/* packet-redbackli.c
+ *
+ * Redback Lawful Intercept Packet dissector
+ *
+ * Copyright 2008 Florian Lohoff <flo[AT]rfc822.org>
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald[AT]wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <time.h>
+#include <string.h>
+
+#include <glib.h>
+#include <epan/packet.h>
+#include <epan/addr_resolv.h>
+#include <epan/prefs.h>
+#include <epan/strutil.h>
+
+void proto_reg_handoff_redbackli(void);
+static int proto_redbackli = -1;
+
+static int hf_redbackli_seqno = -1;		/* Sequence No */
+static int hf_redbackli_liid = -1;		/* LI Id */
+static int hf_redbackli_sessid = -1;		/* Session Id */
+static int hf_redbackli_label = -1;		/* Label */
+static int hf_redbackli_eohpad = -1;		/* End Of Header Padding */
+static int hf_redbackli_unknownavp = -1;	/* Unknown AVP */
+
+static int ett_redbackli = -1;
+
+static dissector_handle_t ip_handle;
+static dissector_handle_t redbackli_handle;
+
+#define RB_AVP_SEQNO	1
+#define RB_AVP_LIID	2
+#define RB_AVP_SESSID	3
+#define RB_AVP_LABEL	20
+#define RB_AVP_EOH	0
+
+static const value_string avp_names[] = {
+	{RB_AVP_SEQNO,		"Sequence No"},
+	{RB_AVP_LIID,		"Lawful Intercept Id"},
+	{RB_AVP_SESSID,		"Session Id"},
+	{RB_AVP_LABEL,		"Label"},
+	{RB_AVP_EOH,		"End Of Header"},
+	{0,			NULL},
+};
+
+static int
+redbackli_dissect_avp(guint8 avptype, guint8 avplen, tvbuff_t *tvb, gint offset, proto_tree *tree)
+{
+	guint32		avpintval;
+	char		*avpcharval;
+	const char	*avpname;
+	proto_tree	*ti, *st=NULL;
+
+	avpname=val_to_str(avptype, avp_names, "Unknown");
+
+	if (tree) {
+		ti = proto_tree_add_text(tree, tvb, offset, avplen+2, "%s AVP", avpname);
+		st = proto_item_add_subtree(ti, ett_redbackli);
+
+		proto_tree_add_text(st, tvb, offset, 1, "AVP Type: %d", avptype);
+		proto_tree_add_text(st, tvb, offset+1, 1, "AVP Length: %d", avplen);
+	}
+
+	switch(avptype) {
+		case(RB_AVP_SEQNO):
+			avpintval=tvb_get_ntohl(tvb, offset+2);
+			if (tree)
+				proto_tree_add_uint(st, hf_redbackli_seqno, tvb,
+						    offset+2, avplen, avpintval);
+			break;
+		case(RB_AVP_LIID):
+			avpintval=tvb_get_ntohl(tvb, offset+2);
+			if (tree)
+				proto_tree_add_uint(st, hf_redbackli_liid, tvb,
+						    offset+2, avplen, avpintval);
+			break;
+		case(RB_AVP_SESSID):
+			avpintval=tvb_get_ntohl(tvb, offset+2);
+			if (tree)
+				proto_tree_add_uint(st, hf_redbackli_sessid, tvb,
+						    offset+2, avplen, avpintval);
+			break;
+		case(RB_AVP_LABEL):
+			avpcharval=tvb_get_string(tvb, offset+2, avplen);
+			if (tree)
+				proto_tree_add_string(st, hf_redbackli_label, tvb,
+						    offset+2, avplen, avpcharval);
+			break;
+		case(RB_AVP_EOH):
+			if (tree && avplen)
+				proto_tree_add_item(st, hf_redbackli_eohpad, tvb,
+						    offset+2, avplen, FALSE);
+			return 1;
+		default:
+			if (tree && avplen)
+				proto_tree_add_item(st, hf_redbackli_unknownavp, tvb,
+						    offset+2, avplen, FALSE);
+			return 0;
+	}
+
+	return 0;
+}
+
+static void
+redbackli_dissect(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+	guint8		avptype, avplen;
+	gint		len, offset=0, eoh=0;
+	proto_tree	*ti, *redbackli_tree=NULL;
+	tvbuff_t	*next_tvb;
+
+	if(check_col(pinfo->cinfo,COL_PROTOCOL))
+		col_add_str(pinfo->cinfo,COL_PROTOCOL,"RBLI");
+
+	if (tree) {
+		ti = proto_tree_add_item(tree, proto_redbackli,
+					 tvb, 0, -1, FALSE);
+		redbackli_tree = proto_item_add_subtree(ti, ett_redbackli);
+	}
+
+	len=tvb_length(tvb);
+	offset=0;
+	eoh=0;
+	while(!eoh && len > 2) {
+		avptype = tvb_get_guint8(tvb, offset+0);
+		avplen = tvb_get_guint8(tvb, offset+1);
+
+		if (len < avplen+2)		/* AVP Complete ? */
+			break;
+
+		eoh=redbackli_dissect_avp(avptype, avplen, tvb, offset, redbackli_tree);
+
+		offset+=2+avplen;
+		len-=2+avplen;
+	}
+
+	next_tvb = tvb_new_subset(tvb, offset, -1, -1);
+	call_dissector(ip_handle, next_tvb, pinfo, tree);
+}
+
+
+#define REDBACKLI_INTSIZE	6
+#define REDBACKLI_EOHSIZE	2
+#define MIN_REDBACKLI_SIZE	(3*REDBACKLI_INTSIZE+REDBACKLI_EOHSIZE)
+
+static gboolean
+redbackli_dissect_heur(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+	gint		len, offset=0, eoh=0;
+	guint8		avptype, avplen;
+
+	len=tvb_length(tvb);
+	if (len < MIN_REDBACKLI_SIZE)
+		return FALSE;
+
+	/*
+	 * We scan the possible AVPs and look out for mismatches.
+	 * An int AVP needs to be 4 byte long, and the eoh must be 0 or 1
+	 * long .. Unknown AVPs also mean not for us ...
+	 *
+	 */
+	while(len > 2 && !eoh) {
+		avptype = tvb_get_guint8(tvb, offset+0);
+		avplen = tvb_get_guint8(tvb, offset+1);
+
+		switch(avptype) {
+			case(RB_AVP_SEQNO):
+			case(RB_AVP_LIID):
+			case(RB_AVP_SESSID):
+				if (avplen != 4)
+					return FALSE;
+				break;
+			case(RB_AVP_LABEL):
+				break;
+			case(RB_AVP_EOH):
+				if (avplen > 1)
+					return FALSE;
+				eoh=1;
+				break;
+			default:
+				return FALSE;
+		}
+		offset+=2+avplen;
+		len-=2+avplen;
+	}
+
+	redbackli_dissect(tvb, pinfo, tree);
+
+	return TRUE;
+}
+void proto_register_redbackli(void) {
+	static hf_register_info hf[] = {
+		{ &hf_redbackli_seqno,
+			{ "Sequence No", "redbackli.seqno", FT_UINT32, BASE_DEC, NULL, 0x0,
+			"Sequence No", HFILL }},
+		{ &hf_redbackli_liid,
+			{ "Lawful Intercept Id", "redbackli.liid", FT_UINT32, BASE_DEC, NULL, 0x0,
+			"LI Identifier", HFILL }},
+		{ &hf_redbackli_sessid,
+			{ "Session Id", "redbackli.sessid", FT_UINT32, BASE_DEC, NULL, 0x0,
+			"Session Identifier", HFILL }},
+		{ &hf_redbackli_label,
+			{ "Label", "redbackli.label", FT_STRING, BASE_NONE, NULL, 0x0,
+			"Label", HFILL }},
+		{ &hf_redbackli_eohpad,
+			{ "End of Header Padding", "redbackli.eohpad", FT_BYTES, BASE_HEX, NULL, 0x0,
+			"", HFILL }},
+		{ &hf_redbackli_unknownavp,
+			{ "Unknown AVP", "redbackli.unknownavp", FT_BYTES, BASE_HEX, NULL, 0x0,
+			"", HFILL }},
+		};
+
+	static gint *ett[] = {
+		&ett_redbackli,
+	};
+
+	proto_redbackli = proto_register_protocol("Redback Lawful Intercept",
+						  "RedbackLI","redbackli");
+
+	proto_register_field_array(proto_redbackli,hf,array_length(hf));
+	proto_register_subtree_array(ett,array_length(ett));
+
+	register_dissector("redbackli", redbackli_dissect, proto_redbackli);
+}
+
+void proto_reg_handoff_redbackli(void) {
+	ip_handle = find_dissector("ip");
+
+	redbackli_handle = find_dissector("redbackli");
+	dissector_add_handle("udp.port", redbackli_handle);
+
+	heur_dissector_add("udp", redbackli_dissect_heur, proto_redbackli);
+}