/* packet-mpeg-sect.c * Routines for MPEG2 (ISO/ISO 13818-1) Section dissection * Copyright 2012, Guy Martin * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * SPDX-License-Identifier: GPL-2.0-or-later */ #include "config.h" #include #include #include #include #include #include #include "packet-mpeg-sect.h" void proto_register_mpeg_sect(void); static int proto_mpeg_sect = -1; static int hf_mpeg_sect_table_id = -1; static int hf_mpeg_sect_syntax_indicator = -1; static int hf_mpeg_sect_reserved = -1; static int hf_mpeg_sect_length = -1; static int hf_mpeg_sect_crc = -1; static int hf_mpeg_sect_crc_status = -1; static gint ett_mpeg_sect = -1; static expert_field ei_mpeg_sect_crc = EI_INIT; static dissector_table_t mpeg_sect_tid_dissector_table; static gboolean mpeg_sect_check_crc = FALSE; /* minimum length of the entire section == bytes from table_id to section_length == 3 bytes */ #define MPEG_SECT_MIN_LEN 3 /* the section_length field is 12 bits, it can add up to 4096 bytes after the initial bytes */ #define MPEG_SECT_MAX_LEN MPEG_SECT_MIN_LEN+4096 #define MPEG_SECT_SYNTAX_INDICATOR_MASK 0x8000 #define MPEG_SECT_RESERVED_MASK 0x7000 #define MPEG_SECT_LENGTH_MASK 0x0FFF /* From ISO/IEC 13818-1 */ enum { TID_PAT, TID_CA, TID_PMT, TID_TS_DESC, TID_SCENE_DESC, TID_OBJECT_DESC, TID_FORBIDEN = 0xFF }; /* From ETSI EN 300 468 */ enum { TID_NIT = 0x40, TID_NIT_OTHER, TID_SDT, TID_SDT_OTHER = 0x46, TID_BAT = 0x4A, TID_EIT_PF = 0x4E, TID_EIT_PF_OTHER, TID_EIT_SC0 = 0x50, TID_EIT_SC1, TID_EIT_SC2, TID_EIT_SC3, TID_EIT_SC4, TID_EIT_SC5, TID_EIT_SC6, TID_EIT_SC7, TID_EIT_SC8, TID_EIT_SC9, TID_EIT_SCA, TID_EIT_SCB, TID_EIT_SCC, TID_EIT_SCD, TID_EIT_SCE, TID_EIT_SCF, TID_EIT_SC0_OTH = 0x60, TID_EIT_SC1_OTH, TID_EIT_SC2_OTH, TID_EIT_SC3_OTH, TID_EIT_SC4_OTH, TID_EIT_SC5_OTH, TID_EIT_SC6_OTH, TID_EIT_SC7_OTH, TID_EIT_SC8_OTH, TID_EIT_SC9_OTH, TID_EIT_SCA_OTH, TID_EIT_SCB_OTH, TID_EIT_SCC_OTH, TID_EIT_SCD_OTH, TID_EIT_SCE_OTH, TID_EIT_SCF_OTH, TID_TDT = 0x70, TID_RST, TID_ST, TID_TOT, TID_SIT = 0x7F }; /* From ETSI EN 301 790 */ enum { TID_RMT = 0x41, /* Conflict with TID_NIT_OTHER */ TID_SCT = 0xA0, TID_FCT, TID_TCT, TID_SPT, TID_CMT, TID_TBTP, TID_PCR, TID_TIM = 0xB0 }; /* From ETSI EN 301 192 */ enum { TID_DVB_MPE = 0x3E }; /* From OC-SP-ETV-AM 1.0-IO5 */ enum { TID_ETV_EISS = 0xE0, TID_ETV_DII = 0xE3, TID_ETV_DDB = 0xE4 }; /* From ETSI TS 102 899 */ enum { TID_AIT = 0x74 }; static const value_string mpeg_sect_table_id_vals[] = { { TID_PAT, "Program Association Table (PAT)" }, { TID_CA, "Conditional Access (CA)" }, { TID_PMT, "Program Map Table (PMT)" }, { TID_TS_DESC, "Transport Stream Description" }, { TID_SCENE_DESC, "ISO/IEC 14496 Scene Description" }, { TID_OBJECT_DESC, "ISO/IEC 14496 Object Description" }, { TID_NIT, "Network Information Table (NIT), current network" }, { TID_NIT_OTHER, "Network Information Table (NIT), other network" }, { TID_SDT, "Service Description Table (SDT), current network" }, { TID_SDT_OTHER, "Service Description (SDT), other network" }, { TID_BAT, "Bouquet Association Table (BAT)" }, { TID_EIT_PF, "Event Information Table (EIT), present/following, actual TS" }, { TID_EIT_PF_OTHER,"Event Information Table (EIT), present/following, other TS" }, { TID_EIT_SC0, "Event Information Table (EIT), schedule 0, actual TS" }, { TID_EIT_SC1, "Event Information Table (EIT), schedule 1, actual TS" }, { TID_EIT_SC2, "Event Information Table (EIT), schedule 2, actual TS" }, { TID_EIT_SC3, "Event Information Table (EIT), schedule 3, actual TS" }, { TID_EIT_SC4, "Event Information Table (EIT), schedule 4, actual TS" }, { TID_EIT_SC5, "Event Information Table (EIT), schedule 5, actual TS" }, { TID_EIT_SC6, "Event Information Table (EIT), schedule 6, actual TS" }, { TID_EIT_SC7, "Event Information Table (EIT), schedule 7, actual TS" }, { TID_EIT_SC8, "Event Information Table (EIT), schedule 8, actual TS" }, { TID_EIT_SC9, "Event Information Table (EIT), schedule 9, actual TS" }, { TID_EIT_SCA, "Event Information Table (EIT), schedule A, actual TS" }, { TID_EIT_SCB, "Event Information Table (EIT), schedule B, actual TS" }, { TID_EIT_SCC, "Event Information Table (EIT), schedule C, actual TS" }, { TID_EIT_SCD, "Event Information Table (EIT), schedule D, actual TS" }, { TID_EIT_SCE, "Event Information Table (EIT), schedule E, actual TS" }, { TID_EIT_SCF, "Event Information Table (EIT), schedule F, actual TS" }, { TID_EIT_SC0_OTH, "Event Information Table (EIT), schedule 0, other TS" }, { TID_EIT_SC1_OTH, "Event Information Table (EIT), schedule 1, other TS" }, { TID_EIT_SC2_OTH, "Event Information Table (EIT), schedule 2, other TS" }, { TID_EIT_SC3_OTH, "Event Information Table (EIT), schedule 3, other TS" }, { TID_EIT_SC4_OTH, "Event Information Table (EIT), schedule 4, other TS" }, { TID_EIT_SC5_OTH, "Event Information Table (EIT), schedule 5, other TS" }, { TID_EIT_SC6_OTH, "Event Information Table (EIT), schedule 6, other TS" }, { TID_EIT_SC7_OTH, "Event Information Table (EIT), schedule 7, other TS" }, { TID_EIT_SC8_OTH, "Event Information Table (EIT), schedule 8, other TS" }, { TID_EIT_SC9_OTH, "Event Information Table (EIT), schedule 9, other TS" }, { TID_EIT_SCA_OTH, "Event Information Table (EIT), schedule A, other TS" }, { TID_EIT_SCB_OTH, "Event Information Table (EIT), schedule B, other TS" }, { TID_EIT_SCC_OTH, "Event Information Table (EIT), schedule C, other TS" }, { TID_EIT_SCD_OTH, "Event Information Table (EIT), schedule D, other TS" }, { TID_EIT_SCE_OTH, "Event Information Table (EIT), schedule E, other TS" }, { TID_EIT_SCF_OTH, "Event Information Table (EIT), schedule F, other TS" }, { TID_TDT, "Time and Date Table (TDT)" }, { TID_RST, "Running Status Table (RST)" }, { TID_ST, "Stuffing Table (ST)" }, { TID_TOT, "Time Offset Table (TOT)" }, { TID_AIT, "Application Information Table (AIT)" }, { TID_SIT, "Selection Information Table (SIT)" }, { TID_SCT, "Superframe Composition Table (SCT)" }, { TID_FCT, "Frame Composition Table (FCT)" }, { TID_TCT, "Time-Slot Composition Table (TCT)" }, { TID_SPT, "Satellite Position Table (SPT)" }, { TID_CMT, "Correction Message Table (CMT)" }, { TID_TBTP, "Terminal Burst Time Plan (TBTP)" }, { TID_TIM, "Terminal Information Message (TIM)" }, { TID_DVB_MPE, "DVB MultiProtocol Encapsulation (MPE)" }, { TID_ETV_EISS, "ETV Integrated Signaling Stream (EISS)" }, { TID_ETV_DII, "ETV Download Info Indication" }, { TID_ETV_DDB, "ETV Download Data Block" }, { TID_FORBIDEN, "Forbidden" }, { 0, NULL } }; static void mpeg_sect_prompt(packet_info *pinfo, gchar* result) { snprintf(result, MAX_DECODE_AS_PROMPT_LEN, "Table ID %u as", GPOINTER_TO_UINT(p_get_proto_data(pinfo->pool, pinfo, proto_mpeg_sect, MPEG_SECT_TID_KEY))); } static gpointer mpeg_sect_value(packet_info *pinfo) { return p_get_proto_data(pinfo->pool, pinfo, proto_mpeg_sect, MPEG_SECT_TID_KEY); } /* read a utc_time field in a tvb and write it to the utc_time struct the encoding of the field is according to DVB-SI specification, section 5.2.5 16bit modified julian day (MJD), 24bit 6*4bit BCD digits hhmmss return the length in bytes or -1 for error */ gint packet_mpeg_sect_mjd_to_utc_time(tvbuff_t *tvb, gint offset, nstime_t *utc_time) { gint bcd_time_offset; /* start offset of the bcd time in the tvbuff */ guint8 hour, min, sec; if (!utc_time) return -1; nstime_set_zero(utc_time); utc_time->secs = (tvb_get_ntohs(tvb, offset) - 40587) * 86400; bcd_time_offset = offset+2; hour = MPEG_SECT_BCD44_TO_DEC(tvb_get_guint8(tvb, bcd_time_offset)); min = MPEG_SECT_BCD44_TO_DEC(tvb_get_guint8(tvb, bcd_time_offset+1)); sec = MPEG_SECT_BCD44_TO_DEC(tvb_get_guint8(tvb, bcd_time_offset+2)); if (hour>23 || min>59 || sec>59) return -1; utc_time->secs += hour*3600 + min*60 + sec; return 5; } guint packet_mpeg_sect_header(tvbuff_t *tvb, guint offset, proto_tree *tree, guint *sect_len, gboolean *ssi) { return packet_mpeg_sect_header_extra(tvb, offset, tree, sect_len, NULL, ssi, NULL); } guint packet_mpeg_sect_header_extra(tvbuff_t *tvb, guint offset, proto_tree *tree, guint *sect_len, guint *reserved, gboolean *ssi, proto_item **items) { guint tmp; guint len = 0; proto_item *pi[PACKET_MPEG_SECT_PI__SIZE]; gint i; for (i = 0; i < PACKET_MPEG_SECT_PI__SIZE; i++) { pi[i] = NULL; } if (tree) { pi[PACKET_MPEG_SECT_PI__TABLE_ID] = proto_tree_add_item(tree, hf_mpeg_sect_table_id, tvb, offset + len, 1, ENC_BIG_ENDIAN); } len++; if (tree) { pi[PACKET_MPEG_SECT_PI__SSI] = proto_tree_add_item(tree, hf_mpeg_sect_syntax_indicator, tvb, offset + len, 2, ENC_BIG_ENDIAN); pi[PACKET_MPEG_SECT_PI__RESERVED] = proto_tree_add_item(tree, hf_mpeg_sect_reserved, tvb, offset + len, 2, ENC_BIG_ENDIAN); pi[PACKET_MPEG_SECT_PI__LENGTH] = proto_tree_add_item(tree, hf_mpeg_sect_length, tvb, offset + len, 2, ENC_BIG_ENDIAN); } tmp = tvb_get_ntohs(tvb, offset + len); if (sect_len) *sect_len = MPEG_SECT_LENGTH_MASK & tmp; if (reserved) *reserved = (MPEG_SECT_RESERVED_MASK & tmp) >> 12; if (ssi) *ssi = (MPEG_SECT_SYNTAX_INDICATOR_MASK & tmp); if (items) { for (i = 0; i < PACKET_MPEG_SECT_PI__SIZE; i++) { items[i] = pi[i]; } } len += 2; return len; } guint packet_mpeg_sect_crc(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint start, guint end) { if (mpeg_sect_check_crc) { proto_tree_add_checksum(tree, tvb, end, hf_mpeg_sect_crc, hf_mpeg_sect_crc_status, &ei_mpeg_sect_crc, pinfo, crc32_mpeg2_tvb_offset(tvb, start, end), ENC_BIG_ENDIAN, PROTO_CHECKSUM_VERIFY); } else { proto_tree_add_checksum(tree, tvb, end, hf_mpeg_sect_crc, hf_mpeg_sect_crc_status, &ei_mpeg_sect_crc, pinfo, crc32_mpeg2_tvb_offset(tvb, start, end), ENC_BIG_ENDIAN, PROTO_CHECKSUM_NO_FLAGS); } return 4; } static int dissect_mpeg_sect(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) { gint tvb_len; gint offset = 0; guint section_length = 0; gboolean syntax_indicator = FALSE; guint8 table_id; proto_item *ti; proto_tree *mpeg_sect_tree; /* the incoming tvb contains only one section, no additional data */ tvb_len = (gint)tvb_reported_length(tvb); if (tvb_lenMPEG_SECT_MAX_LEN) return 0; table_id = tvb_get_guint8(tvb, offset); p_add_proto_data(pinfo->pool, pinfo, proto_mpeg_sect, MPEG_SECT_TID_KEY, GUINT_TO_POINTER(table_id)); /* Check if a dissector can parse the current table */ if (dissector_try_uint(mpeg_sect_tid_dissector_table, table_id, tvb, pinfo, tree)) return tvb_len; /* If no dissector is registered, use the common one */ col_set_str(pinfo->cinfo, COL_PROTOCOL, "MPEG SECT"); col_add_fstr(pinfo->cinfo, COL_INFO, "Table ID 0x%02x", table_id); ti = proto_tree_add_item(tree, proto_mpeg_sect, tvb, offset, -1, ENC_NA); mpeg_sect_tree = proto_item_add_subtree(ti, ett_mpeg_sect); proto_item_append_text(ti, " Table_ID=0x%02x", table_id); packet_mpeg_sect_header(tvb, offset, mpeg_sect_tree, §ion_length, &syntax_indicator); if (syntax_indicator) packet_mpeg_sect_crc(tvb, pinfo, mpeg_sect_tree, 0, (section_length-1)); return tvb_len; } void proto_register_mpeg_sect(void) { static hf_register_info hf[] = { { &hf_mpeg_sect_table_id, { "Table ID", "mpeg_sect.tid", FT_UINT8, BASE_HEX, VALS(mpeg_sect_table_id_vals), 0, NULL, HFILL } }, { &hf_mpeg_sect_syntax_indicator, { "Syntax indicator", "mpeg_sect.syntax_indicator", FT_UINT16, BASE_DEC, NULL, MPEG_SECT_SYNTAX_INDICATOR_MASK, NULL, HFILL } }, { &hf_mpeg_sect_reserved, { "Reserved", "mpeg_sect.reserved", FT_UINT16, BASE_HEX, NULL, MPEG_SECT_RESERVED_MASK, NULL, HFILL } }, { &hf_mpeg_sect_length, { "Length", "mpeg_sect.len", FT_UINT16, BASE_DEC, NULL, MPEG_SECT_LENGTH_MASK, NULL, HFILL } }, { &hf_mpeg_sect_crc, { "CRC 32", "mpeg_sect.crc", FT_UINT32, BASE_HEX, NULL, 0, NULL, HFILL } }, { &hf_mpeg_sect_crc_status, { "CRC 32 Status", "mpeg_sect.crc.status", FT_UINT8, BASE_NONE, VALS(proto_checksum_vals), 0, NULL, HFILL } }, }; static gint *ett[] = { &ett_mpeg_sect }; static ei_register_info ei[] = { { &ei_mpeg_sect_crc, { "mpeg_sect.crc.invalid", PI_CHECKSUM, PI_WARN, "Invalid CRC", EXPFILL }}, }; /* Decode As handling */ static build_valid_func mpeg_sect_da_build_value[1] = {mpeg_sect_value}; static decode_as_value_t mpeg_sect_da_values = {mpeg_sect_prompt, 1, mpeg_sect_da_build_value}; static decode_as_t mpeg_sect_da = {"mpeg_sect", "mpeg_sect.tid", 1, 0, &mpeg_sect_da_values, NULL, NULL, decode_as_default_populate_list, decode_as_default_reset, decode_as_default_change, NULL}; module_t *mpeg_sect_module; expert_module_t* expert_mpeg_sect; proto_mpeg_sect = proto_register_protocol("MPEG2 Section", "MPEG SECT", "mpeg_sect"); register_dissector("mpeg_sect", dissect_mpeg_sect, proto_mpeg_sect); proto_register_field_array(proto_mpeg_sect, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); expert_mpeg_sect = expert_register_protocol(proto_mpeg_sect); expert_register_field_array(expert_mpeg_sect, ei, array_length(ei)); mpeg_sect_module = prefs_register_protocol(proto_mpeg_sect, NULL); prefs_register_bool_preference(mpeg_sect_module, "verify_crc", "Verify the section CRC", "Whether the section dissector should verify the CRC", &mpeg_sect_check_crc); mpeg_sect_tid_dissector_table = register_dissector_table("mpeg_sect.tid", "MPEG SECT Table ID", proto_mpeg_sect, FT_UINT8, BASE_HEX); register_decode_as(&mpeg_sect_da); } /* * 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: */