/* packet-coap.c * Routines for COAP packet disassembly * draft-ietf-core-coap-03.txt * draft-ietf-core-block-00.txt * draft-ietf-core-observe-00.txt * Shoichi Sakane * * $Id$ * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #ifdef HAVE_CONFIG_H # include "config.h" #endif #include #include #include #include static dissector_table_t media_type_dissector_table; static int proto_coap = -1; static int hf_coap_version = -1; static int hf_coap_ttype = -1; static int hf_coap_opt_count = -1; static int hf_coap_code = -1; static int hf_coap_tid = -1; static int hf_coap_opt_delta = -1; static int hf_coap_opt_length = -1; static int hf_coap_opt_ctype = -1; static int hf_coap_opt_etag = -1; static int hf_coap_opt_max_age = -1; static int hf_coap_opt_uri_authority = -1; static int hf_coap_opt_location = -1; static int hf_coap_opt_uri_path = -1; static int hf_coap_opt_subscr_lifetime = -1; static int hf_coap_opt_token = -1; static int hf_coap_opt_block_number = -1; static int hf_coap_opt_block_mflag = -1; static int hf_coap_opt_block_size = -1; static int hf_coap_opt_uri_query = -1; static gint ett_coap = -1; static gint ett_coap_option = -1; static gint ett_coap_payload = -1; /* TODO: COAP port number will be assigned by IANA after the draft become a RFC */ #define DEFAULT_COAP_PORT 61616 static const gchar *coap_content_type = NULL; static guint global_coap_port_number = DEFAULT_COAP_PORT; static gint block_number = ~0; static guint block_mflag = 0; /* * Transaction Type */ static const value_string vals_ttype[] = { { 0, "Confirmable" }, { 1, "Non-Confirmable" }, { 2, "Acknowledgement" }, { 3, "Reset" }, { 0, NULL }, }; /* * Method Code * Response Code */ static const value_string vals_code[] = { /* method code */ { 1, "GET" }, { 2, "POST" }, { 3, "PUT" }, { 4, "DELETE" }, /* response code */ { 40, "100 Continue" }, { 80, "200 OK"}, { 81, "201 Created"}, { 124, "304 Not Modified"}, { 160, "400 Bad Request"}, { 164, "404 Not Found"}, { 165, "405 Method Not Allowed"}, { 175, "415 Unsupported Media Type"}, { 200, "500 Internal Server Error"}, { 202, "502 Bad Gateway"}, { 203, "503 Service Unavailable"}, { 204, "504 Gateway Timeout"}, { 240, "Token Option required by server"}, { 241, "Uri-Authority Option required by server"}, { 242, "Critical Option not supported"}, { 0, NULL }, }; /* * Option Headers * No-Option must not be included in this structure, is handled in the function * of the dissector, especially. */ #define COAP_OPT_CONTENT_TYPE 1 #define COAP_OPT_MAX_AGE 2 #define COAP_OPT_ETAG 4 #define COAP_OPT_URI_AUTHORITY 5 #define COAP_OPT_LOCATION 6 #define COAP_OPT_URI_PATH 9 #define COAP_OPT_SUBSCR_LIFETIME 10 #define COAP_OPT_TOKEN 11 #define COAP_OPT_BLOCK 13 #define COAP_OPT_URI_QUERY 15 static const value_string vals_opt_type[] = { { COAP_OPT_CONTENT_TYPE, "Content-Type" }, { COAP_OPT_MAX_AGE, "Max-age" }, { COAP_OPT_ETAG, "Etag" }, { COAP_OPT_URI_AUTHORITY, "Uri-Authority" }, { COAP_OPT_LOCATION, "Location" }, { COAP_OPT_URI_PATH, "Uri-Path" }, { COAP_OPT_SUBSCR_LIFETIME, "Subscription Lifetime" }, { COAP_OPT_TOKEN, "Token" }, { COAP_OPT_BLOCK, "Block" }, { COAP_OPT_URI_QUERY, "Uri-Query" }, { 0, NULL }, }; static const value_string vals_ctype[] = { { 0, "text/plain" }, { 1, "text/xml" }, { 2, "text/csv" }, { 3, "text/html" }, { 21, "image/gif" }, { 22, "image/jpeg" }, { 23, "image/png" }, { 24, "image/tiff" }, { 25, "audio/raw" }, { 26, "video/raw" }, { 40, "application/link-format" }, { 41, "application/xml" }, { 42, "application/octet-stream" }, { 43, "application/rdf+xml" }, { 44, "application/soap+xml" }, { 45, "application/atom+xml" }, { 46, "application/xmpp+xml" }, { 47, "application/exi" }, { 48, "application/x-bxml" }, { 49, "application/fastinfoset" }, { 50, "application/soap+fastinfoset" }, { 51, "application/json" }, { 0, NULL }, }; void proto_reg_handoff_coap(void); static void dissect_coap_opt(tvbuff_t *tvb, proto_tree *subtree, gint offset, gint opt_length, int hfindex) { proto_tree_add_item(subtree, hfindex, tvb, offset, opt_length, FALSE); } static void dissect_coap_opt_ctype(tvbuff_t *tvb, packet_info *pinfo, proto_tree *subtree, gint offset, gint opt_length) { guint32 opt_ctype = 0; proto_item *pi; opt_ctype = tvb_get_guint8(tvb, offset); coap_content_type = val_to_str(opt_ctype, vals_ctype, "Unknown %d"); pi = proto_tree_add_item(subtree, hf_coap_opt_ctype, tvb, offset, 1, FALSE); if (opt_length != 1) expert_add_info_format(pinfo, pi, PI_MALFORMED, PI_WARN, "Parameter has invalid length; should be 1"); } /* the value of opt_length should be checked out of this function */ static void dissect_coap_opt_time(tvbuff_t *tvb, proto_tree *subtree, gint offset, gint opt_length, int hfindex) { guint32 time = 0; switch (opt_length) { case 0: time = 0; break; case 1: time = (guint32)tvb_get_guint8(tvb, offset); break; case 2: time = (guint32)tvb_get_ntohs(tvb, offset); break; case 3: time = (guint32)tvb_get_ntoh24(tvb, offset); break; case 4: time = (guint32)tvb_get_ntohl(tvb, offset); break; default: proto_tree_add_text(subtree, tvb, 0, 0, "Invalid length: %d", opt_length); break; } proto_tree_add_int_format(subtree, hfindex, tvb, offset, opt_length, time, "%d (s)", time); return; } static void dissect_coap_opt_block(tvbuff_t *tvb, proto_tree *subtree, gint offset, gint opt_length) { guint8 val = 0; guint encoded_block_size = 0; guint block_size; proto_item *item = NULL; switch (opt_length) { case 1: block_number = (guint)(tvb_get_guint8(tvb, offset) >> 4); break; case 2: block_number = (guint)(tvb_get_ntohs(tvb, offset) >> 4); break; case 3: block_number = (guint)(tvb_get_ntoh24(tvb, offset) >> 4); break; default: proto_tree_add_text(subtree, tvb, 0, 0, "Invalid length: %d", opt_length); return; } val = tvb_get_guint8(tvb, offset + opt_length - 1) & 0x0f; encoded_block_size = val & 0x07; block_mflag = val & 0x08; proto_tree_add_int(subtree, hf_coap_opt_block_number, tvb, offset, opt_length, block_number); proto_tree_add_item(subtree, hf_coap_opt_block_mflag, tvb, offset + opt_length - 1, 1, FALSE); block_size = 1 << (encoded_block_size + 4); item = proto_tree_add_item(subtree, hf_coap_opt_block_size, tvb, offset + opt_length - 1, 1, FALSE); proto_item_append_text(item, ", Result: %d", block_size); } /* * dissector for each option of COAP. * return the total length of the option including the header (e.g. delta and length). */ static int dissect_coap_options(tvbuff_t *tvb, packet_info *pinfo, proto_tree *coap_tree, gint offset, guint8 opt_count, guint8 *opt_code) { guint8 opt_delta; gint opt_length; proto_tree *subtree = NULL; proto_item *item = NULL; gint opt_hlen = 0; tvbuff_t *tvb_lenbuf = NULL; opt_delta = (tvb_get_guint8(tvb, offset) & 0xf0) >> 4; *opt_code += opt_delta; /* * Length: * Normally Length is a 4-bit unsigned integer * allowing values of 0-14 octets. When the length is 15 or more, * another byte is added as an 8-bit unsigned integer plus 15 * allowing values of 15-270 octets. */ opt_length = (tvb_get_guint8(tvb, offset) & 0x0f); opt_hlen = 1; if (opt_length == 0x0f) { opt_length += tvb_get_guint8(tvb, offset + 1); opt_hlen = 2; } item = proto_tree_add_text(coap_tree, tvb, offset, opt_hlen + opt_length, "Option #%u: %s (Type: %u)", opt_count, val_to_str(*opt_code, vals_opt_type, "Unknown Option"), *opt_code); subtree = proto_item_add_subtree(item, ett_coap_option); proto_tree_add_item(subtree, hf_coap_opt_delta, tvb, offset, 1, FALSE); tvb_lenbuf = tvb_new_subset(tvb, offset, opt_hlen, opt_hlen); proto_tree_add_uint_bits_format_value(subtree, hf_coap_opt_length, tvb_lenbuf, 4, opt_hlen == 1 ? 4 : 12, opt_length, "%d", opt_length); offset += opt_hlen; /* if opt_code is a multiple of 14, that means the option is a noop option */ if (*opt_code % 14 == 0) { proto_tree_add_text(subtree, tvb, 0, 0, "No-Op option"); } else { switch (*opt_code) { case COAP_OPT_CONTENT_TYPE: dissect_coap_opt_ctype(tvb, pinfo, subtree, offset, opt_length); break; case COAP_OPT_MAX_AGE: dissect_coap_opt_time(tvb, subtree, offset, opt_length, hf_coap_opt_max_age); break; case COAP_OPT_SUBSCR_LIFETIME: dissect_coap_opt_time(tvb, subtree, offset, opt_length, hf_coap_opt_subscr_lifetime); break; case COAP_OPT_ETAG: dissect_coap_opt(tvb, subtree, offset, opt_length, hf_coap_opt_etag); break; case COAP_OPT_URI_AUTHORITY: dissect_coap_opt(tvb, subtree, offset, opt_length, hf_coap_opt_uri_authority); break; case COAP_OPT_LOCATION: dissect_coap_opt(tvb, subtree, offset, opt_length, hf_coap_opt_location); break; case COAP_OPT_URI_PATH: dissect_coap_opt(tvb, subtree, offset, opt_length, hf_coap_opt_uri_path); break; case COAP_OPT_TOKEN: dissect_coap_opt(tvb, subtree, offset, opt_length, hf_coap_opt_token); break; case COAP_OPT_BLOCK: dissect_coap_opt_block(tvb, subtree, offset, opt_length); break; case COAP_OPT_URI_QUERY: dissect_coap_opt(tvb, subtree, offset, opt_length, hf_coap_opt_uri_query); default: proto_tree_add_text(subtree, tvb, 0, 0, "Unkown Option Type"); } } return offset + opt_length; } static void dissect_coap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree) { guint offset = 0; proto_item *coap_root = NULL; proto_tree *coap_tree = NULL; guint8 ttype = 0; guint8 opt_count = 0; guint8 code = 0; guint16 tid = 0; guint coap_length = 0; guint8 opt_code = 0; int i; col_set_str(pinfo->cinfo, COL_PROTOCOL, "COAP"); col_clear(pinfo->cinfo, COL_INFO); if (!parent_tree) return; /* initialize the COAP length and the content-type */ /* * the length of COAP message is not specified in the COAP header. * It has to be from the lower layer. the iplen of packet_info is not accurate. * Currently, the length is just copied from the reported length of the tvbuffer. */ coap_length = tvb_reported_length(tvb); coap_content_type = NULL; coap_root = proto_tree_add_item(parent_tree, proto_coap, tvb, offset, -1, FALSE); coap_tree = proto_item_add_subtree(coap_root, ett_coap); proto_tree_add_item(coap_tree, hf_coap_version, tvb, offset, 1, FALSE); proto_tree_add_item(coap_tree, hf_coap_ttype, tvb, offset, 1, FALSE); ttype = (tvb_get_guint8(tvb, offset) & 0x30) >> 4; col_add_fstr(pinfo->cinfo, COL_INFO, "%s", val_to_str(ttype, vals_ttype, "Unknown %d")); proto_tree_add_item(coap_tree, hf_coap_opt_count, tvb, offset, 1, FALSE); opt_count = tvb_get_guint8(tvb, offset) & 0x0f; offset += 1; proto_tree_add_item(coap_tree, hf_coap_code, tvb, offset, 1, FALSE); code = tvb_get_guint8(tvb, offset); col_append_fstr(pinfo->cinfo, COL_INFO, ", %s", val_to_str(code, vals_code, "Unknown %d")); offset += 1; proto_tree_add_item(coap_tree, hf_coap_tid, tvb, offset, 2, FALSE); tid = tvb_get_ntohs(tvb, offset); offset += 2; /* append the header information */ proto_item_append_text(coap_tree, ", TID: %u, Length: %u", tid, coap_length); block_number = ~0; /* dissect the options */ for (i = 1; i <= opt_count; i++) { offset = dissect_coap_options(tvb, pinfo, coap_tree, offset, i, &opt_code); if (coap_length < offset) { /* error */ proto_tree_add_text(coap_tree, tvb, 0, 0, "Invalid length: coap_length(%d) < offset(%d)", coap_length, offset); return; } } /* dissect the payload */ if (coap_length > offset) { proto_tree *payload_tree = NULL; proto_item *payload_item = NULL; tvbuff_t *payload_tvb; guint payload_length = coap_length - offset; char *ctype_str_default = ""; /* * TODO: * currently, coap_content_type is used to distinguish whether * the content-type was specified. If we need to properly handle * the case when the type was unknown, we need another flag. */ if (coap_content_type == NULL) { /* default: coap-02 section 3.2.1 */ /* when it's NULL, "text/plain" is set anyway */ coap_content_type = "text/plain"; ctype_str_default = " (default)"; } /* * TODO: should the content type be canonicalized ? * currently assuming it be small. */ payload_item = proto_tree_add_text(coap_tree, tvb, offset, -1, "Payload Content-Type: %s%s, Length: %u, offset: %u", coap_content_type, ctype_str_default, payload_length, offset); payload_tree = proto_item_add_subtree(payload_item, ett_coap_payload); payload_tvb = tvb_new_subset(tvb, offset, payload_length, payload_length); dissector_try_string(media_type_dissector_table, coap_content_type, payload_tvb, pinfo, payload_tree); } if (block_number != ~0) { col_append_fstr(pinfo->cinfo, COL_INFO, ", %sBlock #%d", block_mflag ? "" : "End of ", block_number); } } /* * Protocol initialization */ void proto_register_coap(void) { static hf_register_info hf[] = { { &hf_coap_version, { "Version", "coap.version", FT_UINT8, BASE_DEC, NULL, 0xc0, "COAP Version", HFILL }}, { &hf_coap_ttype, { "Type", "coap.type", FT_UINT8, BASE_DEC, VALS(&vals_ttype), 0x30, "COAP Transaction Type", HFILL }}, { &hf_coap_opt_count, { "Option Count", "coap.optcount", FT_UINT8, BASE_DEC, NULL, 0x0f, "COAP Option Count", HFILL }}, { &hf_coap_code, { "Code", "coap.code", FT_UINT8, BASE_DEC, VALS(&vals_code), 0x0, "COAP Method or Response Code", HFILL }}, { &hf_coap_tid, { "Transaction ID", "coap.tid", FT_UINT16, BASE_DEC, NULL, 0x0, "COAP Transaction ID", HFILL }}, { &hf_coap_opt_delta, { "Delta", "coap.opt.delta", FT_UINT8, BASE_DEC, NULL, 0xf0, "COAP Option Delta", HFILL }}, { &hf_coap_opt_length, { "Length", "coap.opt.length", FT_UINT16, BASE_DEC, NULL, 0x0, "COAP Option Length", HFILL }}, { &hf_coap_opt_ctype, { "Content-type", "coap.opt.ctype", FT_UINT8, BASE_DEC, VALS(&vals_ctype), 0x0, "COAP Content Type", HFILL }}, { &hf_coap_opt_max_age, { "Max-age", "coap.opt.max_age", FT_INT32, BASE_DEC, NULL, 0x0, "COAP Max-age", HFILL }}, { &hf_coap_opt_etag, { "Etag", "coap.opt.etag", FT_BYTES, BASE_NONE, NULL, 0x0, "COAP Etag", HFILL }}, { &hf_coap_opt_uri_authority, { "Uri-Authority", "coap.opt.uri_auth", FT_STRING, BASE_NONE, NULL, 0x0, "COAP Uri-Authority", HFILL }}, { &hf_coap_opt_location, { "Location", "coap.opt.location", FT_STRING, BASE_NONE, NULL, 0x0, "COAP Location", HFILL }}, { &hf_coap_opt_uri_path, { "Uri-Path", "coap.opt.uri_path", FT_STRING, BASE_NONE, NULL, 0x0, "COAP Uri-Path", HFILL }}, { &hf_coap_opt_subscr_lifetime, { "Subscription Lifetime", "coap.opt.subscr_lifetime", FT_INT32, BASE_DEC, NULL, 0x0, "COAP Subscription Lifetime", HFILL }}, { &hf_coap_opt_token, { "Token", "coap.opt.token", FT_BYTES, BASE_NONE, NULL, 0x0, "COAP Token", HFILL }}, { &hf_coap_opt_block_number, { "Block Number", "coap.opt.block_number", FT_INT32, BASE_DEC, NULL, 0x0, "COAP Block Number", HFILL }}, { &hf_coap_opt_block_mflag, { "More Flag", "coap.opt.block_mflag", FT_UINT8, BASE_DEC, NULL, 0x08, "COAP Block More Size", HFILL }}, { &hf_coap_opt_block_size, { "Encoded Block Size", "coap.opt.block_size", FT_UINT8, BASE_DEC, NULL, 0x07, "COAP Encoded Block Size", HFILL }}, { &hf_coap_opt_uri_query, { "Uri-Query", "coap.opt.uri_query", FT_STRING, BASE_NONE, NULL, 0x0, "COAP Uri-Query", HFILL }}, }; static gint *ett[] = { &ett_coap, &ett_coap_option, &ett_coap_payload, }; module_t *coap_module; proto_coap = proto_register_protocol("Constrained Application Protocol", "COAP", "coap"); proto_register_field_array(proto_coap, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); register_dissector("coap", dissect_coap, proto_coap); /* Register our configuration options */ coap_module = prefs_register_protocol (proto_coap, proto_reg_handoff_coap); prefs_register_uint_preference (coap_module, "udp_port", "COAP port number", "Port number used for COAP traffic", 10, &global_coap_port_number); } void proto_reg_handoff_coap(void) { static gboolean coap_prefs_initialized = FALSE; static dissector_handle_t coap_handle; static guint coap_port_number; if (!coap_prefs_initialized) { coap_handle = find_dissector("coap"); media_type_dissector_table = find_dissector_table("media_type"); coap_prefs_initialized = TRUE; } else { dissector_delete_uint("udp.port", coap_port_number, coap_handle); dissector_delete_uint("tcp.port", coap_port_number, coap_handle); } coap_port_number = global_coap_port_number; dissector_add_uint("udp.port", coap_port_number, coap_handle); dissector_add_uint("tcp.port", coap_port_number, coap_handle); }