From Jelmer Vernooij via https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=6686

Dissector for the bzr smart server protocol

The attached patch adds basic support for dissecting the bzr smart server protocol ( http://wiki.wireshark.org/Bazaar ).

svn path=/trunk/; revision=40260

1 files changed, 333 insertions, 0 deletions

diff --git a/epan/dissectors/packet-bzr.c b/epan/dissectors/packet-bzr.c
new file mode 100644
index 0000000000..63a20449bd
--- /dev/null
+++ b/epan/dissectors/packet-bzr.c
@@ -0,0 +1,333 @@
+/* packet-bzr.c
+ * Routines for Bazaar packet dissection
+ * Copyright 2011, Jelmer Vernooij <jelmer@samba.org>
+ *
+ * http://doc.bazaar.canonical.com/developers/network-protocol.html
+ *
+ * $Id$
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * Copied from packet-pop.c
+ *
+ * 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 <glib.h>
+#include <epan/packet.h>
+#include <epan/strutil.h>
+#include <epan/prefs.h>
+#include "packet-tcp.h"
+
+static int proto_bzr = -1;
+
+static gint ett_bzr = -1;
+static gint ett_prefixed_bencode = -1;
+static gint ett_prefixed_bytes = -1;
+
+static gint hf_bzr_prefixed_bencode = -1;
+static gint hf_bzr_prefixed_bencode_len = -1;
+static gint hf_bzr_prefixed_bencode_data = -1;
+static gint hf_bzr_bytes = -1;
+static gint hf_bzr_bytes_data = -1;
+static gint hf_bzr_bytes_length = -1;
+static gint hf_bzr_result = -1;
+static gint hf_bzr_packet_protocol_version = -1;
+static gint hf_bzr_packet_kind = -1;
+
+#define REQUEST_VERSION_TWO "bzr request 2\n"
+#define RESPONSE_VERSION_TWO "bzr response 2\n"
+#define MESSAGE_VERSION_THREE "bzr message 3 (bzr 1.6)\n"
+
+#define TCP_PORT_BZR			4155
+
+static const value_string message_part_kind[] = {
+   {'s', "Structure"},
+   {'b', "Bytes"},
+   {'o', "Single byte"},
+   {'e', "End"},
+   {0, NULL}
+};
+
+static const value_string message_results[] = {
+   {'S', "Success"},
+   {'E', "Error"},
+   {0, NULL}
+};
+
+/* desegmentation of Bazaar over TCP */
+static gboolean bzr_desegment = TRUE;
+
+static guint get_bzr_prefixed_len(tvbuff_t *tvb, int offset)
+{
+	guint header_len;
+	header_len = tvb_get_ntohl(tvb, offset);
+	return 4 + header_len;
+}
+
+static guint
+get_bzr_pdu_len(packet_info *pinfo _U_, tvbuff_t *tvb, int offset)
+{
+	int next_offset;
+	gint len = 0;
+	gint protocol_version_len;
+	guint8 cmd = 0;
+
+	/* Protocol version */
+	protocol_version_len = tvb_find_line_end(tvb, offset, -1, &next_offset,
+											 TRUE);
+	if (protocol_version_len == -1) /* End of the packet not seen yet */
+		return -1;
+
+	len += protocol_version_len + 1;
+
+	/* Headers */
+	len += get_bzr_prefixed_len(tvb, next_offset);
+
+	while (tvb_length_remaining(tvb, offset + len) > 0) {
+		cmd = tvb_get_guint8(tvb, offset + len);
+		len += 1;
+
+		switch (cmd) {
+		case 's':
+		case 'b':
+			len += get_bzr_prefixed_len(tvb, offset + len);
+			break;
+		case 'o':
+			len += 1;
+			break;
+		case 'e':
+			return len;
+		}
+	}
+
+	return -1;
+}
+
+static gint
+dissect_prefixed_bencode(tvbuff_t *tvb, gint offset, packet_info *pinfo _U_,
+						 proto_tree *tree)
+{
+	guint32 plen;
+	proto_tree             *prefixed_bencode_tree;
+	proto_item             *ti;
+
+	plen = tvb_get_ntohl(tvb, offset);
+
+	ti = proto_tree_add_item(tree, hf_bzr_prefixed_bencode, tvb, offset, 4 +
+							 plen, ENC_NA);
+	prefixed_bencode_tree = proto_item_add_subtree(ti, ett_prefixed_bencode);
+
+	if (prefixed_bencode_tree)
+	{
+		proto_tree_add_item(prefixed_bencode_tree, hf_bzr_prefixed_bencode_len,
+							tvb, offset, 4, ENC_BIG_ENDIAN);
+
+		proto_tree_add_item(prefixed_bencode_tree, hf_bzr_prefixed_bencode_data,
+							tvb, offset+4, plen, ENC_NA);
+	}
+
+	return 4 + plen;
+}
+
+static gint
+dissect_prefixed_bytes(tvbuff_t *tvb, gint offset, packet_info *pinfo _U_,
+					   proto_tree *tree)
+{
+	guint32 plen;
+	proto_tree *prefixed_bytes_tree;
+	proto_item *ti;
+
+	plen = tvb_get_ntohl(tvb, offset);
+
+	ti = proto_tree_add_item(tree, hf_bzr_bytes, tvb, offset, 4 +
+							 plen, ENC_NA);
+	prefixed_bytes_tree = proto_item_add_subtree(ti, ett_prefixed_bytes);
+
+	if (prefixed_bytes_tree)
+	{
+		proto_tree_add_item(prefixed_bytes_tree, hf_bzr_bytes_length,
+							tvb, offset, 4, ENC_BIG_ENDIAN);
+
+		proto_tree_add_item(prefixed_bytes_tree, hf_bzr_bytes_data,
+							tvb, offset+4, plen, ENC_NA);
+	}
+
+	return 4 + plen;
+}
+
+static gint
+dissect_body(tvbuff_t *tvb, gint offset, packet_info *pinfo, proto_tree *tree)
+{
+	guint8 cmd = 0;
+
+	while (tvb_length_remaining(tvb, offset) > 0) {
+		cmd = tvb_get_guint8(tvb, offset);
+		proto_tree_add_item(tree, hf_bzr_packet_kind, tvb, offset, 1,
+							ENC_NA);
+		offset += 1;
+
+		switch (cmd) {
+		case 's':
+			offset += dissect_prefixed_bencode(tvb, offset, pinfo, tree);
+			break;
+		case 'b':
+			offset += dissect_prefixed_bytes(tvb, offset, pinfo, tree);
+			break;
+		case 'o':
+			proto_tree_add_item(tree, hf_bzr_result, tvb, offset, 1,
+								ENC_NA);
+			offset += 1;
+			break;
+		case 'e':
+			break;
+		}
+	}
+
+	return offset;
+}
+
+static void
+dissect_bzr_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+	proto_tree             *bzr_tree;
+	proto_item             *ti;
+	int offset = 0;
+	gint protocol_version_len;
+
+	ti = proto_tree_add_item(tree, proto_bzr, tvb, offset, -1, ENC_NA);
+	bzr_tree = proto_item_add_subtree(ti, ett_bzr);
+
+	protocol_version_len = tvb_find_line_end(tvb, offset, -1, &offset, TRUE);
+	if (protocol_version_len == -1) /* Invalid packet */
+		return;
+
+	if (bzr_tree)
+	{
+		proto_tree_add_item(bzr_tree, hf_bzr_packet_protocol_version, tvb, 0,
+							protocol_version_len+1, ENC_NA);
+	}
+
+	offset += dissect_prefixed_bencode(tvb, offset, pinfo, bzr_tree);
+	offset += dissect_body(tvb, offset, pinfo, bzr_tree);
+}
+
+static void
+dissect_bzr(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+	gint offset = 0, pdu_len;
+	tvbuff_t *next_tvb;
+
+	col_set_str(pinfo->cinfo, COL_PROTOCOL, "BZR");
+
+	col_set_str(pinfo->cinfo, COL_INFO, "Bazaar Smart Protocol");
+
+	while (tvb_reported_length_remaining(tvb, offset) > 0) {
+		pdu_len = get_bzr_pdu_len(pinfo, tvb, offset);
+		if (pdu_len == -1) {
+			if (pinfo->can_desegment && bzr_desegment) {
+				pinfo->desegment_offset = offset;
+				pinfo->desegment_len = DESEGMENT_ONE_MORE_SEGMENT;
+				return;
+			} else {
+				pdu_len = tvb_reported_length_remaining(tvb, offset);
+			}
+		}
+		next_tvb = tvb_new_subset(tvb, offset, pdu_len, pdu_len);
+		dissect_bzr_pdu(next_tvb, pinfo, tree);
+		offset += pdu_len;
+	}
+}
+
+void
+proto_register_bzr(void)
+{
+	static hf_register_info hf[] = {
+		{ &hf_bzr_packet_kind,
+			{ "Packet kind", "bzr.kind", FT_UINT8, BASE_NONE,
+				VALS(message_part_kind), 0x0, NULL, HFILL },
+		},
+		{ &hf_bzr_packet_protocol_version,
+			{ "Protocol version", "bzr.protocol_version", FT_STRING, BASE_NONE,
+				NULL, 0x0, NULL, HFILL },
+		},
+		{ &hf_bzr_prefixed_bencode,
+			{ "Bencode packet", "bzr.bencode", FT_BYTES, BASE_NONE, NULL, 0x0,
+				"Serialized structure of integers, dictionaries, strings and "
+					"lists.", HFILL },
+		},
+		{ &hf_bzr_prefixed_bencode_len,
+			{ "Bencode packet length", "bzr.bencode.length", FT_UINT32,
+				BASE_HEX, NULL, 0x0, NULL, HFILL },
+		},
+		{ &hf_bzr_prefixed_bencode_data,
+			{ "Bencode packet data", "bzr.bencode.data", FT_BYTES, BASE_NONE,
+				NULL, 0x0, NULL, HFILL },
+		},
+		{ &hf_bzr_bytes,
+			{ "Prefixed bytes", "bzr.bytes", FT_BYTES, BASE_NONE, NULL, 0x0,
+				"Bytes field with prefixed 32-bit length", HFILL },
+		},
+		{ &hf_bzr_bytes_data,
+			{ "Prefixed bytes data", "bzr.bytes.data", FT_BYTES, BASE_NONE,
+				NULL, 0x0, NULL, HFILL },
+		},
+		{ &hf_bzr_bytes_length,
+			{ "Prefixed bytes length", "bzr.bytes.length", FT_UINT32, BASE_HEX,
+				NULL, 0x0, NULL, HFILL },
+		},
+		{ &hf_bzr_result,
+			{ "Result", "bzr.result", FT_UINT8, BASE_HEX,
+				VALS(message_results), 0x0,
+				"Command result (success or failure with error message)", HFILL
+			},
+		},
+	};
+
+	static gint *ett[] = {
+		&ett_bzr,
+		&ett_prefixed_bencode,
+		&ett_prefixed_bytes,
+	};
+
+	module_t *bzr_module;
+	proto_bzr = proto_register_protocol("Bazaar Smart Protocol", "Bazaar", "bzr");
+	register_dissector("bzr", dissect_bzr, proto_bzr);
+	proto_register_field_array(proto_bzr, hf, array_length(hf));
+	proto_register_subtree_array(ett, array_length(ett));
+
+	bzr_module = prefs_register_protocol(proto_bzr, NULL);
+
+	prefs_register_bool_preference(bzr_module, "desegment",
+								   "Reassemble Bazaar messages spanning multiple TCP segments",
+								   "Whether the Bazaar dissector should reassemble messages spanning multiple TCP segments."
+								   " To use this option, you must also enable \"Allow subdissectors to reassemble TCP streams\" in the TCP protocol settings.",
+								   &bzr_desegment);
+}
+
+void
+proto_reg_handoff_bzr(void)
+{
+  dissector_handle_t bzr_handle;
+
+  bzr_handle = find_dissector("bzr");
+  dissector_add_uint("tcp.port", TCP_PORT_BZR, bzr_handle);
+}