/* file-rtpdump.c * * Routines for rtpdump file dissection * Copyright 2023, David Perry * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * This dissects the rtpdump file format as generated by Wireshark. * See also https://wiki.wireshark.org/rtpdump * This file format was created as part of rtptools: * https://github.com/irtlab/rtptools * * SPDX-License-Identifier: GPL-2.0-or-later */ #include "config.h" #include #include #include #include void proto_register_rtpdump(void); void proto_reg_handoff_rtpdump(void); /* Initialize the protocol and registered fields */ static int proto_rtpdump; static int hf_rtpdump_text_header; static int hf_rtpdump_play_program; static int hf_rtpdump_version; static int hf_rtpdump_txt_ipv4; static int hf_rtpdump_txt_ipv6; static int hf_rtpdump_txt_port; static int hf_rtpdump_binary_header; static int hf_rtpdump_ts_sec; static int hf_rtpdump_ts_usec; static int hf_rtpdump_ts; static int hf_rtpdump_bin_addr; static int hf_rtpdump_bin_port; static int hf_rtpdump_padding; static int hf_rtpdump_pkt; static int hf_rtpdump_pkt_len; static int hf_rtpdump_pkt_plen; static int hf_rtpdump_pkt_offset; static int hf_rtpdump_pkt_data; /* Initialize the subtree pointers */ static int ett_rtpdump; static int ett_rtpdump_text_header; static int ett_rtpdump_binary_header; static int ett_rtpdump_pkt; static expert_field ei_rtpdump_unknown_program; static expert_field ei_rtpdump_unknown_version; static expert_field ei_rtpdump_bad_txt_addr; static expert_field ei_rtpdump_bad_txt_port; static expert_field ei_rtpdump_bin_ipv6; static expert_field ei_rtpdump_addrs_match; static expert_field ei_rtpdump_addrs_mismatch; static expert_field ei_rtpdump_caplen; /* Reasonable minimum length for the RTP header (including the magic): * - 13 for "#!rtpplay1.0 " * - WS_INET_ADDRSTRLEN characters for a destination IPv4 address * - 1 for a slash * - 3 characters for a destination port number * - 1 character for a newline * - 4 bytes for each of start seconds, start useconds, source IPv4 * - 2 bytes for each of source port, padding */ #define RTP_HEADER_MIN_LEN 24+WS_INET_ADDRSTRLEN static int dissect_rtpdump(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, void *data _U_) { proto_tree *tree, *subtree; proto_item *ti; int tvb_len = tvb_captured_length(tvb); unsigned pkt_num = 1; static const uint8_t shebang[] = {'#', '!'}; static const char rtpplay[] = "rtpplay"; static const char rtpver[] = "1.0"; int offset = 0; int i = 0; int slash = 0; int eol = 0; int space = 0; uint8_t *str = NULL; uint16_t txt_port = 0; uint32_t bin_port = 0; ws_in4_addr txt_ipv4 = 0; ws_in6_addr txt_ipv6 = {0}; ws_in4_addr bin_ipv4 = 0; bool txt_is_ipv6 = false; nstime_t start_time = NSTIME_INIT_ZERO; int pkt_length; int data_length; if (tvb_len < RTP_HEADER_MIN_LEN) return 0; if (0 != tvb_memeql(tvb, 0, shebang, sizeof(shebang))) return 0; if (-1 == (eol = tvb_find_uint8(tvb, 0, -1, '\n')) || -1 == (slash = tvb_find_uint8(tvb, 0, eol, '/')) || -1 == (space = tvb_find_uint8(tvb, 0, slash, ' '))) { return 0; } ti = proto_tree_add_item(parent_tree, proto_rtpdump, tvb, offset, -1, ENC_NA); tree = proto_item_add_subtree(ti, ett_rtpdump); /* Handle the text header */ ti = proto_tree_add_item(tree, hf_rtpdump_text_header, tvb, offset, eol+1, ENC_ASCII); subtree = proto_item_add_subtree(ti, ett_rtpdump_text_header); /* Get the program name */ offset += 2; for (i = offset; g_ascii_isalpha(tvb_get_uint8(tvb, i)); i++) /* empty loop */ ; ti = proto_tree_add_item_ret_string(subtree, hf_rtpdump_play_program, tvb, offset, i-offset, ENC_ASCII, pinfo->pool, (const uint8_t **)&str); if (0 != g_strcmp0(str, rtpplay)) { expert_add_info(pinfo, ti, &ei_rtpdump_unknown_program); } /* Get the program version */ offset = i; ti = proto_tree_add_item_ret_string(subtree, hf_rtpdump_version, tvb, offset, space-offset, ENC_ASCII, pinfo->pool, (const uint8_t **)&str); if (0 != g_strcmp0(str, rtpver)) { expert_add_info(pinfo, ti, &ei_rtpdump_unknown_version); } /* Get the text IP */ offset = space + 1; str = tvb_get_string_enc(pinfo->pool, tvb, offset, slash-offset, ENC_ASCII); if (ws_inet_pton4(str, &txt_ipv4)) { proto_tree_add_ipv4(subtree, hf_rtpdump_txt_ipv4, tvb, offset, slash-offset, txt_ipv4); } else if (ws_inet_pton6(str, &txt_ipv6)) { txt_is_ipv6 = true; proto_tree_add_ipv6(subtree, hf_rtpdump_txt_ipv6, tvb, offset, slash-offset, &txt_ipv6); } else { proto_tree_add_expert(subtree, pinfo, &ei_rtpdump_bad_txt_addr, tvb, offset, eol-offset); } /* Get the text port */ offset = slash + 1; str = tvb_get_string_enc(pinfo->pool, tvb, offset, eol-offset, ENC_ASCII); if (ws_strtou16(str, NULL, &txt_port)) { proto_tree_add_uint(subtree, hf_rtpdump_txt_port, tvb, offset, eol-offset, txt_port); } else { proto_tree_add_expert(subtree, pinfo, &ei_rtpdump_bad_txt_port, tvb, offset, eol-offset); } /* Handle the binary header */ offset = eol + 1; ti = proto_tree_add_item(tree, hf_rtpdump_binary_header, tvb, offset, 16, ENC_NA); subtree = proto_item_add_subtree(ti, ett_rtpdump_binary_header); proto_tree_add_item_ret_uint(subtree, hf_rtpdump_ts_sec, tvb, offset, 4, ENC_BIG_ENDIAN, (uint32_t *)&start_time.secs); proto_tree_add_item_ret_uint(subtree, hf_rtpdump_ts_usec, tvb, offset+4, 4, ENC_BIG_ENDIAN, &start_time.nsecs); start_time.nsecs *= 1000; ti = proto_tree_add_time(subtree, hf_rtpdump_ts, tvb, offset, 8, &start_time); proto_item_set_generated(ti); offset += 8; ti = proto_tree_add_item(subtree, hf_rtpdump_bin_addr, tvb, offset, 4, ENC_BIG_ENDIAN); /* Force internal representation to big-endian as per wsutil/inet_ipv4.h */ bin_ipv4 = g_htonl(tvb_get_uint32(tvb, offset, ENC_BIG_ENDIAN)); offset += 4; proto_tree_add_item_ret_uint(subtree, hf_rtpdump_bin_port, tvb, offset, 2, ENC_BIG_ENDIAN, &bin_port); offset += 2; proto_tree_add_item(subtree, hf_rtpdump_padding, tvb, offset, 2, ENC_NA); offset += 2; if (txt_is_ipv6) { expert_add_info(pinfo, ti, &ei_rtpdump_bin_ipv6); expert_add_info(pinfo, subtree, &ei_rtpdump_addrs_mismatch); } else if(bin_ipv4 == txt_ipv4 && bin_port == txt_port) { expert_add_info(pinfo, subtree, &ei_rtpdump_addrs_match); } else { expert_add_info(pinfo, subtree, &ei_rtpdump_addrs_mismatch); } /* Handle individual packets */ while (offset < tvb_len) { pkt_length = tvb_get_ntohs(tvb, offset); ti = proto_tree_add_item(tree, hf_rtpdump_pkt, tvb, offset, pkt_length, ENC_NA); subtree = proto_item_add_subtree(ti, ett_rtpdump_pkt); proto_item_set_text(subtree, "Packet %d", pkt_num++); pkt_length -= 8; proto_tree_add_item(subtree, hf_rtpdump_pkt_len, tvb, offset, 2, ENC_BIG_ENDIAN); offset += 2; ti = proto_tree_add_item_ret_uint(subtree, hf_rtpdump_pkt_plen, tvb, offset, 2, ENC_BIG_ENDIAN, &data_length); if (data_length > pkt_length) { expert_add_info(pinfo, ti, &ei_rtpdump_caplen); } offset += 2; proto_tree_add_item(subtree, hf_rtpdump_pkt_offset, tvb, offset, 4, ENC_BIG_ENDIAN); offset += 4; proto_tree_add_item(subtree, hf_rtpdump_pkt_data, tvb, offset, pkt_length, ENC_NA); offset += pkt_length; } return tvb_len; } static bool dissect_rtpdump_heur(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, void *data) { return dissect_rtpdump(tvb, pinfo, parent_tree, data) > 0; } /****************** Register the protocol with Wireshark ******************/ void proto_register_rtpdump(void) { static hf_register_info hf[] = { { &hf_rtpdump_text_header, { "Text header", "rtpdump.text_header", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL } }, { &hf_rtpdump_play_program, { "Play program", "rtpdump.play_program", FT_STRING, BASE_NONE, NULL, 0x0, "Program to be used to play this stream", HFILL } }, { &hf_rtpdump_version, { "File format version", "rtpdump.version", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL } }, { &hf_rtpdump_txt_ipv4, { "Text IPv4 address", "rtpdump.txt_addr", FT_IPv4, BASE_NONE, NULL, 0x0, NULL, HFILL } }, { &hf_rtpdump_txt_ipv6, { "Text IPv6 address", "rtpdump.txt_addr", FT_IPv6, BASE_NONE, NULL, 0x0, NULL, HFILL } }, { &hf_rtpdump_txt_port, { "Text port", "rtpdump.txt_port", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL } }, { &hf_rtpdump_binary_header, { "Binary header", "rtpdump.binary_header", FT_BYTES, BASE_NONE|BASE_NO_DISPLAY_VALUE, NULL, 0x0, NULL, HFILL } }, { &hf_rtpdump_ts_sec, { "Start time (seconds)", "rtpdump.ts.sec", FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL } }, { &hf_rtpdump_ts_usec, { "Start time (microseconds)", "rtpdump.ts_usec", FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL } }, { &hf_rtpdump_ts, { "Start time", "rtpdump.ts", FT_ABSOLUTE_TIME, ABSOLUTE_TIME_LOCAL, NULL, 0x0, NULL, HFILL } }, { &hf_rtpdump_bin_addr, { "Binary IPv4 address", "rtpdump.bin_addr", FT_IPv4, BASE_NONE, NULL, 0x0, NULL, HFILL } }, { &hf_rtpdump_bin_port, { "Binary port", "rtpdump.bin_port", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL } }, { &hf_rtpdump_padding, { "Padding", "rtpdump.padding", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL } }, { &hf_rtpdump_pkt, { "Packet", "rtpdump.packet", FT_BYTES, BASE_NONE|BASE_NO_DISPLAY_VALUE, NULL, 0x0, NULL, HFILL } }, { &hf_rtpdump_pkt_len, { "Packet length", "rtpdump.pkt_len", FT_UINT16, BASE_DEC, NULL, 0x0, "Total packet length", HFILL } }, { &hf_rtpdump_pkt_plen, { "Data length", "rtpdump.pkt_plen", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL } }, { &hf_rtpdump_pkt_offset, { "Time offset (milliseconds)", "rtpdump.pkt_offset", FT_UINT32, BASE_DEC, NULL, 0x0, "Time from start of capture", HFILL } }, { &hf_rtpdump_pkt_data, { "Data", "rtpdump.pkt_data", FT_BYTES, BASE_NONE|BASE_NO_DISPLAY_VALUE, NULL, 0x0, NULL, HFILL } }, }; /* Setup protocol subtree array */ static int *ett[] = { &ett_rtpdump, &ett_rtpdump_text_header, &ett_rtpdump_binary_header, &ett_rtpdump_pkt, }; static ei_register_info ei[] = { { &ei_rtpdump_unknown_program, { "rtpdump.play_program.unknown", PI_PROTOCOL, PI_WARN, "Playback program not the expected 'rtpplay', dissection may be incorrect", EXPFILL }}, { &ei_rtpdump_unknown_version, { "rtpdump.version.unknown", PI_PROTOCOL, PI_WARN, "Version not recognized, dissection may be incorrect", EXPFILL }}, { &ei_rtpdump_bad_txt_addr, { "rtpdump.txt_addr.bad", PI_PROTOCOL, PI_WARN, "Unparseable text address", EXPFILL }}, { &ei_rtpdump_bad_txt_port, { "rtpdump.txt_port.bad", PI_PROTOCOL, PI_WARN, "Unparseable text port", EXPFILL }}, { &ei_rtpdump_bin_ipv6, { "rtpdump.bin_addr.ipv6", PI_PROTOCOL, PI_NOTE, "Binary IPv4 address may be a truncated IPv6 address", EXPFILL }}, { &ei_rtpdump_addrs_match, { "rtpdump.address.match", PI_PROTOCOL, PI_CHAT, "Text and binary addresses and ports match -- file likely generated by rtpdump", EXPFILL }}, { &ei_rtpdump_addrs_mismatch, { "rtpdump.address.mismatch", PI_PROTOCOL, PI_CHAT, "Text and binary addresses and ports do not match -- file likely generated by wireshark", EXPFILL }}, { &ei_rtpdump_caplen, { "rtpdump.pkt_plen.truncated", PI_PROTOCOL, PI_NOTE, "Data was truncated during capture", EXPFILL }}, }; expert_module_t* expert_rtpdump; /* Register the protocol name and description */ proto_rtpdump = proto_register_protocol("RTPDump file format", "rtpdump", "rtpdump"); /* Required function calls to register the header fields * and subtrees used */ proto_register_field_array(proto_rtpdump, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); expert_rtpdump = expert_register_protocol(proto_rtpdump); expert_register_field_array(expert_rtpdump, ei, array_length(ei)); register_dissector("rtpdump", dissect_rtpdump, proto_rtpdump); } void proto_reg_handoff_rtpdump(void) { heur_dissector_add("wtap_file", dissect_rtpdump_heur, "RTPDump file", "rtpdump_wtap", proto_rtpdump, HEURISTIC_ENABLE); }