/* packet-wsmp.c * Routines for WAVE Short Message dissection (WSMP) * Copyright 2013, Savari Networks (http://www.savarinetworks.com) (email: smooney@savarinetworks.com) * Based on packet-wsmp.c implemented by * Arada Systems (http://www.aradasystems.com) (email: siva@aradasystems.com) * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * SPDX-License-Identifier: GPL-2.0-or-later * Ref IEEE 1609.3 */ #include "config.h" #include #include #include #include "packet-ieee1609dot2.h" /* elemenID Types */ #define TRANSMITPW 0x04 #define CHANNUM 0x0F #define DATARATE 0x10 #define WSMP 0x80 #define WSMP_S 0x81 #define WSMP_I 0x82 void proto_register_wsmp(void); void proto_reg_handoff_wsmp(void); static dissector_handle_t wsmp_handle; static const value_string wsmp_elemenid_names[] = { { 0x80, "WSMP" }, { 0x81, "WSMP-S" }, { 0x82, "WSMP-I" }, { 0, NULL } }; /* Initialize the protocol and registered fields */ static int proto_wsmp; static int hf_wsmp_version; static int hf_wsmp_var_len_det; static int hf_wsmp_psid; static int hf_wsmp_rate; static int hf_wsmp_channel; static int hf_wsmp_txpower; static int hf_wsmp_WAVEid; static int hf_wsmp_wsmlength; static int hf_wsmp_WSMP_S_data; static int hf_wsmp_subtype; static int hf_wsmp_N_header_opt_ind; static int hf_wsmp_version_v3; static int hf_wsmp_no_elements; static int hf_wsmp_wave_ie; static int hf_wsmp_wave_ie_len; static int hf_wsmp_wave_ie_data; static int hf_wsmp_tpid; /* Initialize the subtree pointers */ static int ett_wsmp; static int ett_wsmdata; static int ett_wsmp_n_hdr; static int ett_wsmp_t_hdr; static int ett_wsmp_ie_ext; static int ett_wsmp_ie; static expert_field ei_wsmp_length_field_err; static expert_field ei_wsmp_psid_invalid; dissector_handle_t IEEE1609dot2_handle; static const value_string wsmp_subtype_vals[] = { { 0x0, "Null-networking protocol" }, { 0x1, "ITS station-internal forwarding" }, { 0x2, "N-hop forwarding" }, { 0x3, "Enables the features of GeoNetworking" }, { 0, NULL } }; static const value_string wsmp_wave_information_elements_vals[] = { { 0, "Reserved" }, { 1, "Reserved" }, { 2, "Reserved" }, { 3, "Reserved" }, { 4, "Transmit Power Used" }, /* WSMP - N - Header 8.3.4.4 */ { 5, "2D Location" }, /* WSA header 8.2.2.6 */ { 6, "3D Location" }, /* WSA header 8.2.2.6 */ { 7, "Advertiser Identifier" }, /* WSA header 8.2.2.6 */ { 8, "Provider Service Context" }, /* WSA Service Info 8.2.3.5 */ { 9, "IPv6 Address" }, /* WSA Service Info 8.2.3.5 */ { 10, "Service Por" }, /* WSA Service Info 8.2.3.5 */ { 11, "Provider MAC Address" }, /* WSA Service Info 8.2.3.5 */ { 12, "EDCA Parameter Set" }, /* WSA Channel Info 8.2.4.8 */ { 13, "Secondary DNS" }, /* WSA WRA 8.2.5.7 */ { 14, "Gateway MAC Address" }, /* WSA WRA 8.2.5.7 */ { 15, "Channel Number" }, /* WSMP - N - Header 8.3.4.2 */ { 16, "Data Rate" }, /* WSMP - N - Header 8.3.4.3 */ { 17, "Repeat Rate" }, /* WSA header 8.2.2.6 */ { 18, "Reserved" }, { 19, "RCPI Threshold" }, /* WSA Service Info 8.2.3.5 */ { 20, "WSA Count Threshold" }, /* WSA Service Info 8.2.3.5 */ { 21, "Channel Access" }, /* WSA Channel Info 8.2.4.8 */ { 22, "WSA Count Threshold Interval" }, /* WSA Service Info 8.2.3.5 */ { 23, "Channel Load" }, /* WSMP-N-Header 8.3.4.5 */ { 0, NULL } }; static const value_string wsmp_tpid_vals[] = { { 0, "The Address Info field contains a PSID and a WAVE Information Element Extension field is not present" }, { 1, "The Address Info field contains a PSID and a WAVE Information Element Extension field is present" }, { 2, "The Address Info field contains source and destination ITS port numbers and a WAVE Information Element Extension field is not present" }, { 3, "The Address Info field contains source and destination ITS port numbers and a WAVE Information Element Extension field is present" }, { 4, "LPP mode and a WAVE Information Element Extension field is not present" }, { 5, "LPP mode and a WAVE Information Element Extension field is present" }, { 0, NULL } }; /* 4.1.2 P-encoding of PSIDs This standard defines a compact encoding for PSID referred to as p-encoding. Octets are numbered from the left starting at zero (Octet 0). The length of the PSID is indicated by Octet 0, where the position of the first zero-value bit in descending order of bit significance in the octet indicates the length in octets of the p?encoded PSID. Using p-encoding, a binary "0" in the most-significant bit indicates a one-octet PSID; a binary "10" in the two most-significant bits indicates a two-octet PSID; a binary "110" in the three most-significant bits indicates a three-octet PSID; and a binary "1110" in the four most-significant bits indicates a four-octet PSID. */ static int dissect_wsmp_psid(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree, int offset, uint32_t *psid) { uint8_t oct; uint32_t psidLen = 0; oct = tvb_get_uint8(tvb, offset); *psid = 0; if ((oct & 0xF0) == 0xF0) { proto_tree_add_expert(tree, pinfo, &ei_wsmp_psid_invalid, tvb, offset, 1); return offset + 1; } else if ((oct & 0xF0) == 0xE0) { psidLen = 4; } else if ((oct & 0xE0) == 0xC0) { psidLen = 3; } else if ((oct & 0xC0) == 0x80) { psidLen = 2; } else if ((oct & 0x80) == 0x00) { psidLen = 1; } if (psidLen == 1) *psid = oct; else if (psidLen == 2) *psid = (tvb_get_ntohs(tvb, offset) & ~0x8000) + 0x80; else if (psidLen == 3) *psid = (tvb_get_ntoh24(tvb, offset) & ~0xc00000) + 0x4080; else if (psidLen == 4) *psid = (tvb_get_ntohl(tvb, offset) & ~0xe0000000) + 0x204080; proto_tree_add_bits_item(tree, hf_wsmp_var_len_det, tvb, offset << 3, psidLen, ENC_NA); proto_tree_add_uint_bits_format_value(tree, hf_wsmp_psid, tvb, (offset << 3) + psidLen, (psidLen << 3) - psidLen,*psid,ENC_BIG_ENDIAN,"%s(%u)", val64_to_str_const(*psid, ieee1609dot2_Psid_vals, "Unknown"), *psid); offset += psidLen; return offset; } /* 8.1.3 Length and Count field encoding*/ static int dissect_wsmp_length_and_count(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int offset, int hf_id, uint16_t* value) { uint8_t oct, len; uint16_t val; /* For values in the range of 0 through 127, Length and Count values * are represented in a single-octet encoded as an unsigned integer. For values in the range 128 through 16 * 383, values are represented as two octets encoded as follows. If the most significant bit of the field is 0b0, * then this indicates a one-octet Length or Count field. If the two most significant bits of the field are 0b10, * the Length or Count field is a two-octet field, with the remaining 14 bits representing the value encoded as * an unsigned integer.*/ oct = tvb_get_uint8(tvb, offset); if ((oct & 0x80) == 0x80) { if ((oct & 0xc0) == 0x80) { /* Two bytes */ val = tvb_get_ntohs(tvb, offset) & 0x3fff; len = 2; } else { /* Error */ proto_tree_add_expert(tree, pinfo, &ei_wsmp_length_field_err, tvb, offset, 1); val = tvb_get_ntohs(tvb, offset) & 0x3fff; len = 2; } }else{ /* One byte */ val = oct; len = 1; } proto_tree_add_uint(tree, hf_id, tvb, offset, len, val); offset += len; if (value){ *value = val; } return offset; } static int dissect_wsmp_v3(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, uint8_t oct) { proto_tree *sub_tree, *n_tree, *t_tree, *data_tree; proto_item *item, *n_tree_item, *t_tree_item; int offset = 0, ie_start, len_to_set; uint8_t header_opt_ind = (oct & 0x08) >> 3; uint8_t ie; uint16_t count, ie_len, wsm_len; uint32_t tpid, psid = 0; static int * const flags[] = { &hf_wsmp_subtype, &hf_wsmp_N_header_opt_ind, &hf_wsmp_version_v3, NULL }; /* 8.3.2 WSMP Network Header (WSMP-N-Header) */ n_tree = proto_tree_add_subtree(tree, tvb, offset, -1, ett_wsmp_n_hdr, &n_tree_item, "WSMP-N-Header"); /* In Version 3 * B7 B4 B3 B2 B0 | Variable | 1 octet * Subtype |WSMP-NHeader | WSMP Version | WAVE Information Element Extension | TPID * | Option Indicator | | | */ proto_tree_add_bitmask_list(n_tree, tvb, offset, 1, flags, ENC_BIG_ENDIAN); offset++; /* WAVE Information Element Extension */ if (header_opt_ind) { sub_tree = proto_tree_add_subtree(n_tree, tvb, offset, -1, ett_wsmp_ie_ext, &item, "WAVE Information Element Extension"); /* Figure 14 WAVE Information Element Extension */ /* 8.1.3 Length and Count field encoding*/ /* Count( Number of WAVE Information Elements )*/ offset = dissect_wsmp_length_and_count(tvb, pinfo, sub_tree, offset, hf_wsmp_no_elements, &count); while (count) { proto_tree* ie_tree; ie_start = offset; /* WAVE Element ID 1 octet*/ ie = tvb_get_uint8(tvb, offset); ie_tree = proto_tree_add_subtree_format(sub_tree, tvb, offset, -1, ett_wsmp_ie, &item, "%s", val_to_str_const(ie, wsmp_wave_information_elements_vals, "Unknown")); proto_tree_add_item(ie_tree, hf_wsmp_wave_ie, tvb, offset, 1, ENC_BIG_ENDIAN); offset++; /* Length */ offset = dissect_wsmp_length_and_count(tvb, pinfo, ie_tree, offset, hf_wsmp_wave_ie_len, &ie_len); proto_tree_add_item(ie_tree, hf_wsmp_wave_ie_data, tvb, offset, ie_len, ENC_NA); offset += ie_len; len_to_set = offset - ie_start; proto_item_set_len(item, len_to_set); count--; } } /* TPID */ proto_tree_add_item_ret_uint(n_tree, hf_wsmp_tpid, tvb, offset, 1, ENC_BIG_ENDIAN, &tpid); offset++; proto_item_set_end(n_tree_item, tvb, offset); /* WSMP-T-Header */ t_tree = proto_tree_add_subtree(tree, tvb, offset, -1, ett_wsmp_t_hdr, &t_tree_item, "WSMP-T-Header"); switch (tpid) { case 0: /* The Address Info field contains a PSID and a WAVE Information Element Extension field is not present.*/ offset = dissect_wsmp_psid(tvb, pinfo, t_tree, offset, &psid); break; default: break; } /* WSM Length */ offset = dissect_wsmp_length_and_count(tvb, pinfo, t_tree, offset, hf_wsmp_wave_ie_len, &wsm_len); proto_item_set_end(t_tree_item, tvb, offset); /* WSM Data */ data_tree = proto_tree_add_subtree(tree, tvb, offset, wsm_len, ett_wsmdata, NULL, "Wave Short Message"); if((psid == (uint32_t)psid_vehicle_to_vehicle_safety_and_awarenesss) && (IEEE1609dot2_handle)){ ieee1609dot2_set_next_default_psid(pinfo, psid); tvbuff_t * tvb_new = tvb_new_subset_remaining(tvb, offset); call_dissector(IEEE1609dot2_handle, tvb_new, pinfo, data_tree); } else if ((psid == (uint32_t)psid_intersection_safety_and_awareness) && (IEEE1609dot2_handle)) { ieee1609dot2_set_next_default_psid(pinfo, psid); tvbuff_t * tvb_new = tvb_new_subset_remaining(tvb, offset); call_dissector(IEEE1609dot2_handle, tvb_new, pinfo, data_tree); } return tvb_captured_length(tvb); } static int dissect_wsmp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) { /* Set up structures needed to add the protocol subtree and manage it */ proto_item *ti; proto_tree *wsmp_tree, *wsmdata_tree; tvbuff_t *wsmdata_tvb; uint16_t wsmlength, offset = 0; uint32_t psid, supLen; uint8_t elemenId, elemenLen, msb, oct, version; /* Make entries in Protocol column and Info column on summary display */ col_set_str(pinfo->cinfo, COL_PROTOCOL, "WSMP"); col_set_str(pinfo->cinfo, COL_INFO, "WAVE Short Message Protocol IEEE P1609.3"); /* create display subtree for the protocol */ ti = proto_tree_add_item(tree, proto_wsmp, tvb, 0, -1, ENC_NA); wsmp_tree = proto_item_add_subtree(ti, ett_wsmp); /* In Version 3 * B7 B4 B3 B2 B0 * Subtype |WSMP-NHeader | WSMP Version * | Option Indicator */ oct = tvb_get_uint8(tvb, offset); version = oct & 0x07; if (version == 3) { /* Version 3 */ return dissect_wsmp_v3(tvb, pinfo, wsmp_tree, oct); } proto_tree_add_item(wsmp_tree, hf_wsmp_version, tvb, offset, 1, ENC_BIG_ENDIAN); offset++; offset = dissect_wsmp_psid(tvb, pinfo, wsmp_tree, offset, &psid); /* TLV decoder that does not display the T and L elements */ elemenId = tvb_get_uint8(tvb, offset); while ((elemenId != WSMP) && (elemenId != WSMP_S) && (elemenId != WSMP_I)) { offset++; if (elemenId == CHANNUM) { elemenLen = tvb_get_uint8(tvb, offset); offset++; proto_tree_add_item(wsmp_tree, hf_wsmp_channel, tvb, offset, elemenLen, ENC_BIG_ENDIAN); offset += elemenLen; } else if (elemenId == DATARATE) { elemenLen = tvb_get_uint8(tvb, offset); offset++; proto_tree_add_item(wsmp_tree, hf_wsmp_rate, tvb, offset, elemenLen, ENC_BIG_ENDIAN); offset += elemenLen; } else if (elemenId == TRANSMITPW) { elemenLen = tvb_get_uint8(tvb, offset); offset++; proto_tree_add_item(wsmp_tree, hf_wsmp_txpower, tvb, offset, elemenLen, ENC_BIG_ENDIAN); offset += elemenLen; } elemenId = tvb_get_uint8(tvb, offset); } proto_tree_add_item(wsmp_tree, hf_wsmp_WAVEid, tvb, offset, 1, ENC_BIG_ENDIAN); offset++; wsmlength = tvb_get_ntohs( tvb, offset); proto_tree_add_item(wsmp_tree, hf_wsmp_wsmlength, tvb, offset, 2, ENC_BIG_ENDIAN); offset += 2; if (elemenId == WSMP_S) { msb = 1; supLen = 0; while (msb) { msb = tvb_get_uint8(tvb, offset + supLen); msb = msb & 0x80; supLen++; } proto_tree_add_item(wsmp_tree, hf_wsmp_WSMP_S_data, tvb, offset, supLen, ENC_BIG_ENDIAN); wsmlength -= supLen; offset += supLen; } wsmdata_tree = proto_tree_add_subtree(wsmp_tree, tvb, offset, wsmlength, ett_wsmdata, NULL, "Wave Short Message"); wsmdata_tvb = tvb_new_subset_length(tvb, offset, wsmlength); /* TODO: Branch on the application context and display accordingly * Default: call the data dissector */ if (psid == 0x4070) { call_data_dissector(wsmdata_tvb, pinfo, wsmdata_tree); } return tvb_captured_length(tvb); } void proto_register_wsmp(void) { static hf_register_info hf[] = { { &hf_wsmp_version, { "Version", "wsmp.version", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }}, { &hf_wsmp_var_len_det, { "Length", "wsmp.len.det", FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL }}, { &hf_wsmp_psid, { "PSID", "wsmp.psid", FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL }}, { &hf_wsmp_channel, { "Channel", "wsmp.channel", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }}, { &hf_wsmp_rate, { "Data Rate", "wsmp.rate", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }}, { &hf_wsmp_txpower, { "Transmit Power", "wsmp.txpower", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }}, { &hf_wsmp_WAVEid, { "WAVE element id", "wsmp.WAVEid", FT_UINT8, BASE_DEC, VALS(wsmp_elemenid_names), 0x0, NULL, HFILL }}, { &hf_wsmp_wsmlength, { "WSM Length", "wsmp.wsmlength", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }}, { &hf_wsmp_WSMP_S_data, { "WAVE Supplement Data", "wsmp.supplement", FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL }}, { &hf_wsmp_subtype, { "Subtype", "wsmp.subtype", FT_UINT8, BASE_DEC, VALS(wsmp_subtype_vals), 0xF0, NULL, HFILL }}, { &hf_wsmp_N_header_opt_ind, { "WSMP-NHeader Option Indicator(WAVE Information Element Extension)", "wsmp.N_header_opt_ind", FT_BOOLEAN, 8, TFS(&tfs_present_not_present), 0x08, NULL, HFILL }}, { &hf_wsmp_version_v3, { "Version", "wsmp.version_v3", FT_UINT8, BASE_DEC, NULL, 0x07, NULL, HFILL }}, { &hf_wsmp_no_elements, { "Count", "wsmp.no_elements", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }}, { &hf_wsmp_wave_ie, { "WAVE IE", "wsmp.wave_ie", FT_UINT8, BASE_DEC, VALS(wsmp_wave_information_elements_vals), 0x0, NULL, HFILL }}, { &hf_wsmp_wave_ie_len, { "Length", "wsmp.wave_ie_len", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }}, { &hf_wsmp_wave_ie_data, { "Data", "wsmp.wave_ie_data", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }}, { &hf_wsmp_tpid, { "TPID", "wsmp.tpid", FT_UINT8, BASE_DEC, VALS(wsmp_tpid_vals), 0x0, NULL, HFILL }}, }; /* Setup protocol subtree array */ static int *ett[] = { &ett_wsmp, &ett_wsmdata, &ett_wsmp_n_hdr, &ett_wsmp_t_hdr, &ett_wsmp_ie_ext, &ett_wsmp_ie, }; static ei_register_info ei[] = { { &ei_wsmp_length_field_err, { "wsmp.length_field_err", PI_PROTOCOL, PI_ERROR, "Length field wrongly encoded, b6 not 0. The rest of the dissection is suspect", EXPFILL }}, { &ei_wsmp_psid_invalid, { "wsmp.psid.invalid", PI_PROTOCOL, PI_ERROR, "Invalid PSID", EXPFILL }}, }; expert_module_t* expert_wsmp; /* Register the protocol name and description */ proto_wsmp = proto_register_protocol("Wave Short Message Protocol(IEEE P1609.3)", "WSMP", "wsmp"); /* Required function calls to register the header fields and subtrees used */ proto_register_field_array(proto_wsmp, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); expert_wsmp = expert_register_protocol(proto_wsmp); expert_register_field_array(expert_wsmp, ei, array_length(ei)); /* Register the dissector handle */ wsmp_handle = register_dissector("wsmp", dissect_wsmp, proto_wsmp); } void proto_reg_handoff_wsmp(void) { dissector_add_uint("ethertype", ETHERTYPE_WSMP, wsmp_handle); IEEE1609dot2_handle = find_dissector_add_dependency("ieee1609dot2.data", proto_wsmp); } /* * 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: */