/* packet-moldudp64.c * Routines for MoldUDP64 dissection * Copyright 2012, Evan Huus * * http://www.nasdaqtrader.com/content/technicalsupport/specifications/dataproducts/moldudp64.pdf * * 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 void proto_register_moldudp64(void); void proto_reg_handoff_moldudp64(void); static dissector_handle_t moldudp64_handle; /* Initialize the protocol and registered fields */ static int proto_moldudp64; static int hf_moldudp64_session; static int hf_moldudp64_sequence; static int hf_moldudp64_count; static int hf_moldudp64_msgblk; static int hf_moldudp64_msglen; static int hf_moldudp64_msgseq; static int hf_moldudp64_msgdata; #define MOLDUDP64_SESSION_LEN 10 #define MOLDUDP64_SEQUENCE_LEN 8 #define MOLDUDP64_COUNT_LEN 2 #define MOLDUDP64_MSGLEN_LEN 2 #define MOLDUDP64_HEARTBEAT 0x0000 #define MOLDUDP64_ENDOFSESS 0xFFFF /* Initialize the subtree pointers */ static int ett_moldudp64; static int ett_moldudp64_msgblk; static expert_field ei_moldudp64_msglen_invalid; static expert_field ei_moldudp64_end_of_session_extra; static expert_field ei_moldudp64_count_invalid; static expert_field ei_moldudp64_request; static dissector_table_t moldudp64_payload_table; static void moldudp64_prompt(packet_info *pinfo _U_, char* result) { snprintf(result, MAX_DECODE_AS_PROMPT_LEN, "Payload as"); } /* Code to dissect a message block */ static unsigned dissect_moldudp64_msgblk(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, unsigned offset, uint64_t sequence) { proto_item *ti; proto_tree *blk_tree; uint16_t msglen, real_msglen, whole_len; int remaining; tvbuff_t* next_tvb; if (tvb_captured_length_remaining(tvb, offset) < MOLDUDP64_MSGLEN_LEN) return 0; msglen = tvb_get_ntohs(tvb, offset); remaining = tvb_reported_length(tvb) - offset - MOLDUDP64_MSGLEN_LEN; if (remaining < 0) real_msglen = 0; else if (msglen <= remaining) real_msglen = msglen; else real_msglen = remaining; /* msglen and real_msglen only count the data section, and don't * include the two bytes for the length field itself. */ whole_len = real_msglen + MOLDUDP64_MSGLEN_LEN; ti = proto_tree_add_item(tree, hf_moldudp64_msgblk, tvb, offset, whole_len, ENC_NA); blk_tree = proto_item_add_subtree(ti, ett_moldudp64_msgblk); ti = proto_tree_add_uint64(blk_tree, hf_moldudp64_msgseq, tvb, offset, 0, sequence); proto_item_set_generated(ti); ti = proto_tree_add_item(blk_tree, hf_moldudp64_msglen, tvb, offset, MOLDUDP64_MSGLEN_LEN, ENC_BIG_ENDIAN); if (msglen != real_msglen) expert_add_info_format(pinfo, ti, &ei_moldudp64_msglen_invalid, "Invalid Message Length (claimed %u, found %u)", msglen, real_msglen); offset += MOLDUDP64_MSGLEN_LEN; next_tvb = tvb_new_subset_length(tvb, offset, real_msglen); if (!dissector_try_payload_new(moldudp64_payload_table, next_tvb, pinfo, tree, false, NULL)) { proto_tree_add_item(blk_tree, hf_moldudp64_msgdata, tvb, offset, real_msglen, ENC_NA); } return whole_len; } /* Code to actually dissect the packets */ static int dissect_moldudp64(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) { proto_item *ti; proto_tree *moldudp64_tree; unsigned offset = 0; uint16_t count, real_count = 0; uint64_t sequence; /* Check that there's enough data */ if (tvb_reported_length(tvb) < (MOLDUDP64_SESSION_LEN + MOLDUDP64_SEQUENCE_LEN + MOLDUDP64_COUNT_LEN)) return 0; /* Make entries in Protocol column and Info column on summary display */ col_set_str(pinfo->cinfo, COL_PROTOCOL, "MoldUDP64"); /* Clear the info column so it's sane if we crash. We fill it in later when * we've dissected more of the packet. */ col_clear(pinfo->cinfo, COL_INFO); sequence = tvb_get_ntoh64(tvb, MOLDUDP64_SESSION_LEN); count = tvb_get_ntohs(tvb, MOLDUDP64_SESSION_LEN + MOLDUDP64_SEQUENCE_LEN); if (count == MOLDUDP64_HEARTBEAT) col_set_str(pinfo->cinfo, COL_INFO, "MoldUDP64 Heartbeat"); else if (count == MOLDUDP64_ENDOFSESS) col_set_str(pinfo->cinfo, COL_INFO, "MoldUDP64 End Of Session"); else if (count > 0 && tvb_reported_length(tvb) == (MOLDUDP64_SESSION_LEN + MOLDUDP64_SEQUENCE_LEN + MOLDUDP64_COUNT_LEN)) col_set_str(pinfo->cinfo, COL_INFO, "MoldUDP64 Request"); else col_set_str(pinfo->cinfo, COL_INFO, "MoldUDP64 Messages"); /* create display subtree for the protocol */ ti = proto_tree_add_item(tree, proto_moldudp64, tvb, offset, -1, ENC_NA); moldudp64_tree = proto_item_add_subtree(ti, ett_moldudp64); proto_tree_add_item(moldudp64_tree, hf_moldudp64_session, tvb, offset, MOLDUDP64_SESSION_LEN, ENC_ASCII); offset += MOLDUDP64_SESSION_LEN; proto_tree_add_item(moldudp64_tree, hf_moldudp64_sequence, tvb, offset, MOLDUDP64_SEQUENCE_LEN, ENC_BIG_ENDIAN); offset += MOLDUDP64_SEQUENCE_LEN; ti = proto_tree_add_item(moldudp64_tree, hf_moldudp64_count, tvb, offset, MOLDUDP64_COUNT_LEN, ENC_BIG_ENDIAN); offset += MOLDUDP64_COUNT_LEN; while (tvb_reported_length(tvb) >= offset + MOLDUDP64_MSGLEN_LEN) { offset += dissect_moldudp64_msgblk(tvb, pinfo, moldudp64_tree, offset, sequence++); real_count++; } if (count == MOLDUDP64_ENDOFSESS && real_count != 0) { expert_add_info(pinfo, ti, &ei_moldudp64_end_of_session_extra); } else if (count > 0 && real_count == 0) { expert_add_info(pinfo, ti, &ei_moldudp64_request); } else if (real_count != count) { expert_add_info_format(pinfo, ti, &ei_moldudp64_count_invalid, "Invalid Message Count (claimed %u, found %u)", count, real_count); } /* Return the amount of data this dissector was able to dissect */ return tvb_captured_length(tvb); } /* Register the protocol with Wireshark */ void proto_register_moldudp64(void) { /* Setup list of header fields */ static hf_register_info hf[] = { { &hf_moldudp64_session, { "Session", "moldudp64.session", FT_STRING, BASE_NONE, NULL, 0, "The session to which this packet belongs.", HFILL }}, { &hf_moldudp64_sequence, { "Sequence", "moldudp64.sequence", FT_UINT64, BASE_DEC, NULL, 0, "The sequence number of the first message in this packet.", HFILL }}, { &hf_moldudp64_count, { "Count", "moldudp64.count", FT_UINT16, BASE_DEC, NULL, 0, "The number of messages contained in this packet.", HFILL }}, { &hf_moldudp64_msgblk, { "Message Block", "moldudp64.msgblock", FT_NONE, BASE_NONE, NULL, 0, "A message.", HFILL }}, { &hf_moldudp64_msglen, { "Length", "moldudp64.msglen", FT_UINT16, BASE_DEC, NULL, 0, "The length of this message.", HFILL }}, { &hf_moldudp64_msgseq, { "Sequence", "moldudp64.msgseq", FT_UINT64, BASE_DEC, NULL, 0, "The sequence number of this message.", HFILL }}, { &hf_moldudp64_msgdata, { "Payload", "moldudp64.msgdata", FT_BYTES, BASE_NONE, NULL, 0, "The payload data of this message.", HFILL }} }; /* Setup protocol subtree array */ static int *ett[] = { &ett_moldudp64, &ett_moldudp64_msgblk }; static ei_register_info ei[] = { { &ei_moldudp64_msglen_invalid, { "moldudp64.msglen.invalid", PI_MALFORMED, PI_ERROR, "Invalid Message Length", EXPFILL }}, { &ei_moldudp64_end_of_session_extra, { "moldudp64.end_of_session_extra", PI_MALFORMED, PI_ERROR, "End Of Session packet with extra data.", EXPFILL }}, { &ei_moldudp64_count_invalid, { "moldudp64.count.invalid", PI_MALFORMED, PI_ERROR, "Invalid Message Count", EXPFILL }}, { &ei_moldudp64_request, { "moldudp64.request", PI_COMMENTS_GROUP, PI_COMMENT, "Number of Requested Messages", EXPFILL }}, }; expert_module_t* expert_moldudp64; /* Register the protocol name and description */ proto_moldudp64 = proto_register_protocol("MoldUDP64", "MoldUDP64", "moldudp64"); /* Required function calls to register the header fields and subtrees used */ proto_register_field_array(proto_moldudp64, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); expert_moldudp64 = expert_register_protocol(proto_moldudp64); expert_register_field_array(expert_moldudp64, ei, array_length(ei)); moldudp64_payload_table = register_decode_as_next_proto(proto_moldudp64, "moldudp64.payload", "MoldUDP64 Payload", moldudp64_prompt); /* Register the dissector */ moldudp64_handle = register_dissector("moldudp64", dissect_moldudp64, proto_moldudp64); } void proto_reg_handoff_moldudp64(void) { dissector_add_for_decode_as_with_preference("udp.port", moldudp64_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: */