/* packet-smp.c * Routines for Session Multiplex Protocol (SMP) dissection * January 2017 Uli Heilmeier with the help of Michael Mann * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * SPDX-License-Identifier: GPL-2.0-or-later */ /* * References: * https://web.archive.org/web/20171009015219/https://msdn.microsoft.com/en-us/library/cc219643.aspx * https://web.archive.org/web/20171223021159/https://msdn.microsoft.com/en-us/library/dd304523.aspx * https://web.archive.org/web/20171005092351/https://docs.microsoft.com/en-us/sql/relational-databases/native-client/features/using-multiple-active-result-sets-mars * * 0 1 2 3 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | SMID | FLAGS | SID | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | LENGTH | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | SEQNUM | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | WNDW | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | | * / DATA (variable) / * | | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ */ #include #include #include #include #include "packet-tcp.h" void proto_reg_handoff_smp(void); void proto_register_smp(void); static int proto_smp = -1; static int hf_smp_smid = -1; static int hf_smp_flags = -1; static int hf_smp_flags_syn = -1; static int hf_smp_flags_ack = -1; static int hf_smp_flags_fin = -1; static int hf_smp_flags_data = -1; static int hf_smp_sid = -1; static int hf_smp_length = -1; static int hf_smp_seqnum = -1; static int hf_smp_wndw = -1; static int hf_smp_data = -1; static gint ett_smp = -1; static gint ett_smp_flags = -1; #define SMP_FLAGS_SYN 0x01 #define SMP_FLAGS_ACK 0x02 #define SMP_FLAGS_FIN 0x04 #define SMP_FLAGS_DATA 0x08 #define SMP_MIN_LENGTH 16 static dissector_handle_t tds_handle; static dissector_table_t smp_payload_table; static gboolean reassemble_smp = TRUE; static void smp_prompt(packet_info *pinfo _U_, gchar* result) { g_snprintf(result, MAX_DECODE_AS_PROMPT_LEN, "Payload as"); } /* Code to actually dissect the packets */ static int dissect_smp_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, gboolean tds_payload) { guint offset = 0; guint remaining_bytes; proto_item *ti; proto_tree *smp_tree; guint32 flags, sid, smp_length; tvbuff_t* next_tvb; int parsed_bytes; static const int *flag_fields[] = { &hf_smp_flags_syn, &hf_smp_flags_ack, &hf_smp_flags_fin, &hf_smp_flags_data, NULL }; if (tvb_reported_length(tvb) < SMP_MIN_LENGTH) return 0; col_set_str(pinfo->cinfo, COL_PROTOCOL, "SMP"); col_clear(pinfo->cinfo, COL_INFO); ti = proto_tree_add_item(tree, proto_smp, tvb, 0, -1, ENC_NA); smp_tree = proto_item_add_subtree(ti, ett_smp); proto_tree_add_item(smp_tree, hf_smp_smid, tvb, offset, 1, ENC_NA); offset+=1; proto_tree_add_bitmask(smp_tree, tvb, offset, hf_smp_flags, ett_smp_flags, flag_fields, ENC_NA); flags = tvb_get_guint8(tvb, offset); offset += 1; proto_tree_add_item_ret_uint(smp_tree, hf_smp_sid, tvb, offset, 2, ENC_LITTLE_ENDIAN, &sid); col_append_fstr(pinfo->cinfo, COL_INFO, "SID: %u", sid); offset += 2; if (flags & SMP_FLAGS_SYN) col_append_str(pinfo->cinfo, COL_INFO, ", Syn"); if (flags & SMP_FLAGS_ACK) col_append_str(pinfo->cinfo, COL_INFO, ", Ack"); if (flags & SMP_FLAGS_FIN) col_append_str(pinfo->cinfo, COL_INFO, ", Fin"); if (flags & SMP_FLAGS_DATA) col_append_str(pinfo->cinfo, COL_INFO, ", Data"); proto_tree_add_item_ret_uint(smp_tree, hf_smp_length, tvb, offset, 4, ENC_LITTLE_ENDIAN, &smp_length); offset += 4; proto_tree_add_item(smp_tree, hf_smp_seqnum, tvb, offset, 4, ENC_LITTLE_ENDIAN); offset += 4; proto_tree_add_item(smp_tree, hf_smp_wndw, tvb, offset, 4, ENC_LITTLE_ENDIAN); offset += 4; if ((flags & SMP_FLAGS_DATA) && (tvb_reported_length(tvb) > SMP_MIN_LENGTH)) { next_tvb = tvb_new_subset_remaining(tvb, offset); if (tds_payload) { parsed_bytes = call_dissector(tds_handle, next_tvb, pinfo, tree); } else { parsed_bytes = dissector_try_payload(smp_payload_table, next_tvb, pinfo, tree); } if (parsed_bytes <= 0) { remaining_bytes = tvb_reported_length_remaining(tvb, offset); if ( remaining_bytes < (smp_length - SMP_MIN_LENGTH)) { // Fragmented proto_tree_add_item(smp_tree, hf_smp_data, tvb, offset, remaining_bytes, ENC_NA); offset += remaining_bytes; } else { proto_tree_add_item(smp_tree, hf_smp_data, tvb, offset, smp_length - SMP_MIN_LENGTH, ENC_NA); offset += (smp_length - SMP_MIN_LENGTH); } } else { offset += parsed_bytes; } } return offset; } static guint get_smp_pdu_len(packet_info *pinfo _U_, tvbuff_t *tvb, int offset, void *data _U_) { return tvb_get_letohl(tvb, offset + 4); } static int dissect_smp_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) { return dissect_smp_common(tvb, pinfo, tree, FALSE); } static int dissect_smp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data) { if ((tvb_reported_length(tvb) > 0) && (tvb_get_guint8(tvb, 0) == 0x53)) { tcp_dissect_pdus(tvb, pinfo, tree, reassemble_smp, SMP_MIN_LENGTH, get_smp_pdu_len, dissect_smp_pdu, data); return tvb_captured_length(tvb); } return 0; } static int dissect_smp_tds(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) { return dissect_smp_common(tvb, pinfo, tree, TRUE); } void proto_register_smp(void) { static hf_register_info hf[] = { { &hf_smp_smid, { "Smid", "smp.smid", FT_UINT8, BASE_HEX, NULL, 0, NULL, HFILL }}, { &hf_smp_flags, { "Flags", "smp.flags", FT_UINT8, BASE_HEX, NULL, 0, NULL, HFILL } }, { &hf_smp_flags_syn, { "Syn", "smp.flags.syn", FT_BOOLEAN, 8, TFS(&tfs_set_notset), SMP_FLAGS_SYN, NULL, HFILL }}, { &hf_smp_flags_ack, { "Ack", "smp.flags.ack", FT_BOOLEAN, 8, TFS(&tfs_set_notset), SMP_FLAGS_ACK, NULL, HFILL }}, { &hf_smp_flags_fin, { "Fin", "smp.flags.fin", FT_BOOLEAN, 8, TFS(&tfs_set_notset), SMP_FLAGS_FIN, NULL, HFILL }}, { &hf_smp_flags_data, { "Data", "smp.flags.data", FT_BOOLEAN, 8, TFS(&tfs_set_notset), SMP_FLAGS_DATA, NULL, HFILL }}, { &hf_smp_sid, { "SID", "smp.sid", FT_UINT16, BASE_DEC, NULL, 0, "Session ID", HFILL }}, { &hf_smp_length, { "Length", "smp.length", FT_UINT32, BASE_DEC, NULL, 0, NULL, HFILL }}, { &hf_smp_seqnum, { "SeqNum", "smp.seqnum", FT_UINT32, BASE_HEX, NULL, 0, "Sequence Number", HFILL }}, { &hf_smp_wndw, { "Wndw", "smp.wndw", FT_UINT32, BASE_HEX, NULL, 0, "Window Size", HFILL }}, { &hf_smp_data, { "Data", "smp.data", FT_BYTES, BASE_NONE, NULL, 0, NULL, HFILL }}, }; static gint *ett[] = { &ett_smp, &ett_smp_flags, }; module_t *smp_module; proto_smp = proto_register_protocol("Session Multiplex Protocol", "SMP", "smp"); proto_register_field_array(proto_smp, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); register_dissector("smp_tds", dissect_smp_tds, proto_smp); smp_payload_table = register_decode_as_next_proto(proto_smp, "SMP Payload", "smp.payload", "SMP Payload", smp_prompt); smp_module = prefs_register_protocol(proto_smp, NULL); prefs_register_bool_preference(smp_module, "desegment", "Reassemble SMP messages spanning multiple TCP segments", "Whether the SMP 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.", &reassemble_smp); } void proto_reg_handoff_smp(void) { dissector_handle_t smp_handle; smp_handle = create_dissector_handle(dissect_smp, proto_smp); dissector_add_for_decode_as_with_preference("tcp.port", smp_handle); tds_handle = find_dissector_add_dependency("tds", proto_smp); } /* * 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: */