/* packet-bzr.c * Routines for Bazaar packet dissection * Copyright 2011,2013 Jelmer Vernooij * * http://doc.bazaar.canonical.com/developers/network-protocol.html * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * Copied from packet-pop.c * * SPDX-License-Identifier: GPL-2.0-or-later */ #include "config.h" #include #include void proto_register_bzr(void); void proto_reg_handoff_bzr(void); static int proto_bzr; static int ett_bzr; static int ett_prefixed_bencode; static int ett_prefixed_bytes; static int hf_bzr_prefixed_bencode; static int hf_bzr_prefixed_bencode_len; static int hf_bzr_bytes; static int hf_bzr_bytes_data; static int hf_bzr_bytes_length; static int hf_bzr_result; static int hf_bzr_packet_protocol_version; static int hf_bzr_packet_kind; static dissector_handle_t bencode_handle; static dissector_handle_t bzr_handle; #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 bool bzr_desegment = true; static unsigned get_bzr_prefixed_len(tvbuff_t *tvb, int offset) { unsigned header_len; header_len = tvb_get_ntohl(tvb, offset); return 4 + header_len; } static unsigned get_bzr_pdu_len(packet_info *pinfo _U_, tvbuff_t *tvb, int offset) { int next_offset; int len = 0, current_len; int protocol_version_len; uint8_t 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 */ current_len = len; len += get_bzr_prefixed_len(tvb, next_offset); if (current_len > len) /* Make sure we're not going backwards */ return -1; while (tvb_reported_length_remaining(tvb, offset + len) > 0) { cmd = tvb_get_uint8(tvb, offset + len); len += 1; switch (cmd) { case 's': case 'b': current_len = len; len += get_bzr_prefixed_len(tvb, offset + len); if (current_len > len) /* Make sure we're not going backwards */ return -1; break; case 'o': len += 1; break; case 'e': return len; } } return -1; } static int dissect_prefixed_bencode(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree) { uint32_t plen; proto_tree *prefixed_bencode_tree; proto_item *ti; tvbuff_t *subtvb; plen = tvb_get_ntohl(tvb, offset); ti = proto_tree_add_item(tree, hf_bzr_prefixed_bencode, tvb, offset, -1, ENC_NA); prefixed_bencode_tree = proto_item_add_subtree(ti, ett_prefixed_bencode); proto_tree_add_item(prefixed_bencode_tree, hf_bzr_prefixed_bencode_len, tvb, offset, 4, ENC_BIG_ENDIAN); subtvb = tvb_new_subset_length(tvb, offset+4, plen); call_dissector(bencode_handle, subtvb, pinfo, prefixed_bencode_tree); proto_item_set_len(ti, 4 + plen); return 4 + plen; } static int dissect_prefixed_bytes(tvbuff_t *tvb, int offset, packet_info *pinfo _U_, proto_tree *tree) { uint32_t 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, -1, ENC_NA); prefixed_bytes_tree = proto_item_add_subtree(ti, ett_prefixed_bytes); 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); proto_item_set_len(ti, 4 + plen); return 4 + plen; } static int dissect_body(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree) { uint8_t cmd = 0; while (tvb_reported_length_remaining(tvb, offset) > 0) { cmd = tvb_get_uint8(tvb, offset); proto_tree_add_item(tree, hf_bzr_packet_kind, tvb, offset, 1, ENC_ASCII|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_ASCII|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; int 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_ASCII); } offset += dissect_prefixed_bencode(tvb, offset, pinfo, bzr_tree); /*offset +=*/ dissect_body(tvb, offset, pinfo, bzr_tree); } static int dissect_bzr(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) { int 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 tvb_captured_length(tvb); } else { pdu_len = tvb_reported_length_remaining(tvb, offset); } } next_tvb = tvb_new_subset_length(tvb, offset, pdu_len); dissect_bzr_pdu(next_tvb, pinfo, tree); offset += pdu_len; } return tvb_captured_length(tvb); } void proto_register_bzr(void) { static hf_register_info hf[] = { { &hf_bzr_packet_kind, { "Packet kind", "bzr.kind", FT_CHAR, BASE_HEX, 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_NONE, 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_bytes, { "Prefixed bytes", "bzr.bytes", FT_NONE, 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_CHAR, BASE_HEX, VALS(message_results), 0x0, "Command result (success or failure with error message)", HFILL }, }, }; static int *ett[] = { &ett_bzr, &ett_prefixed_bencode, &ett_prefixed_bytes, }; module_t *bzr_module; proto_bzr = proto_register_protocol("Bazaar Smart Protocol", "Bazaar", "bzr"); bzr_handle = 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) { bencode_handle = find_dissector_add_dependency("bencode", proto_bzr); dissector_add_uint_with_preference("tcp.port", TCP_PORT_BZR, bzr_handle); } /* * Editor modelines - https://www.wireshark.org/tools/modelines.html * * Local variables: * c-basic-offset: 4 * tab-width: 8 * indent-tabs-mode: nil * End: * * vi: set shiftwidth=4 tabstop=8 expandtab: * :indentSize=4:tabSize=8:noTabs=true: */