/* packet-coap.c * Routines for CoAP packet disassembly * draft-ietf-core-coap-14.txt * draft-ietf-core-block-10.txt * draft-ietf-core-observe-07.txt * draft-ietf-core-link-format-06.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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #include "config.h" #include #include #include #include void proto_register_coap(void); 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_payload_desc = -1; static int hf_coap_opt_name = -1; static int hf_coap_opt_desc = -1; static int hf_coap_opt_jump = -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_max_age = -1; static int hf_coap_opt_proxy_uri = -1; static int hf_coap_opt_etag = -1; static int hf_coap_opt_uri_host = -1; static int hf_coap_opt_location_path = -1; static int hf_coap_opt_uri_port = -1; static int hf_coap_opt_location_query = -1; static int hf_coap_opt_uri_path = -1; static int hf_coap_opt_observe = -1; static int hf_coap_opt_token = -1; static int hf_coap_opt_accept = -1; static int hf_coap_opt_if_match = -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 int hf_coap_opt_unknown = -1; static gint ett_coap = -1; static gint ett_coap_option = -1; static gint ett_coap_payload = -1; /* CoAP's IANA-assigned port number */ #define DEFAULT_COAP_PORT 5683 /* indicators whether those are to be showed or not */ #define DEFAULT_COAP_CTYPE_VALUE ~0 #define DEFAULT_COAP_BLOCK_NUMBER ~0 static const gchar *coap_ctype_str = NULL; static gint coap_ctype_value = DEFAULT_COAP_CTYPE_VALUE; static guint global_coap_port_number = DEFAULT_COAP_PORT; static gint coap_block_number = DEFAULT_COAP_BLOCK_NUMBER; static guint coap_block_mflag = 0; static gchar coap_uri_str[1024]; /* the maximum is 1024 > 510 = Uri-Host:255 + Uri-Path:255 x 2 */ static gchar coap_uri_query[1024]; /* the maximum is 1024 > 765 = Uri-Query:255 x 3 */ static gchar coap_token_str[128]; /* * Transaction Type */ static const value_string vals_ttype[] = { { 0, "Confirmable" }, { 1, "Non-Confirmable" }, { 2, "Acknowledgement" }, { 3, "Reset" }, { 0, NULL }, }; static const value_string vals_ttype_short[] = { { 0, "CON" }, { 1, "NON" }, { 2, "ACK" }, { 3, "RST" }, { 0, NULL }, }; /* * Method Code * Response Code */ static const value_string vals_code[] = { { 0, "Empty Message" }, /* method code */ { 1, "GET" }, { 2, "POST" }, { 3, "PUT" }, { 4, "DELETE" }, /* response code */ { 65, "2.01 Created" }, { 66, "2.02 Deleted" }, { 67, "2.03 Valid" }, { 68, "2.04 Changed" }, { 69, "2.05 Content" }, { 128, "4.00 Bad Request" }, { 129, "4.01 Unauthorized" }, { 130, "4.02 Bad Option" }, { 131, "4.03 Forbidden" }, { 132, "4.04 Not Found" }, { 133, "4.05 Method Not Allowed" }, { 134, "4.06 Not Acceptable" }, { 136, "4.08 Request Entity Incomplete" }, /* core-block-10 */ { 140, "4.12 Precondition Failed" }, { 141, "4.13 Request Entity Too Large" }, { 143, "4.15 Unsupported Content-Format" }, { 160, "5.00 Internal Server Error" }, { 161, "5.01 Not Implemented" }, { 162, "5.02 Bad Gateway" }, { 163, "5.03 Service Unavailable" }, { 164, "5.04 Gateway Timeout" }, { 165, "5.05 Proxying 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_IF_MATCH 1 #define COAP_OPT_URI_HOST 3 #define COAP_OPT_ETAG 4 #define COAP_OPT_IF_NONE_MATCH 5 #define COAP_OPT_OBSERVE 6 /* core-observe-07 */ #define COAP_OPT_URI_PORT 7 #define COAP_OPT_LOCATION_PATH 8 #define COAP_OPT_URI_PATH 11 #define COAP_OPT_CONTENT_TYPE 12 #define COAP_OPT_MAX_AGE 14 #define COAP_OPT_URI_QUERY 15 #define COAP_OPT_ACCEPT 16 #define COAP_OPT_TOKEN 19 #define COAP_OPT_LOCATION_QUERY 20 #define COAP_OPT_BLOCK2 23 /* core-block-10 */ #define COAP_OPT_BLOCK_SIZE 28 /* core-block-10 */ #define COAP_OPT_BLOCK1 27 /* core-block-10 */ #define COAP_OPT_PROXY_URI 35 static const value_string vals_opt_type[] = { { COAP_OPT_IF_MATCH, "If-Match" }, { COAP_OPT_URI_HOST, "Uri-Host" }, { COAP_OPT_ETAG, "Etag" }, { COAP_OPT_IF_NONE_MATCH, "If-None-Match" }, { COAP_OPT_URI_PORT, "Uri-Port" }, { COAP_OPT_LOCATION_PATH, "Location-Path" }, { COAP_OPT_URI_PATH, "Uri-Path" }, { COAP_OPT_CONTENT_TYPE, "Content-Format" }, { COAP_OPT_MAX_AGE, "Max-age" }, { COAP_OPT_URI_QUERY, "Uri-Query" }, { COAP_OPT_ACCEPT, "Accept" }, { COAP_OPT_TOKEN, "Token" }, { COAP_OPT_LOCATION_QUERY, "Location-Query" }, { COAP_OPT_PROXY_URI, "Proxy-Uri" }, { COAP_OPT_OBSERVE, "Observe" }, { COAP_OPT_BLOCK2, "Block2" }, { COAP_OPT_BLOCK1, "Block1" }, { COAP_OPT_BLOCK_SIZE, "Block Size" }, { 0, NULL }, }; struct coap_option_range_t { guint type; gint min; gint max; } coi[] = { { COAP_OPT_IF_MATCH, 0, 8 }, { COAP_OPT_URI_HOST, 1, 255 }, { COAP_OPT_ETAG, 1, 8 }, { COAP_OPT_IF_NONE_MATCH, 0, 0 }, { COAP_OPT_URI_PORT, 0, 2 }, { COAP_OPT_LOCATION_PATH, 0, 255 }, { COAP_OPT_URI_PATH, 0, 255 }, { COAP_OPT_CONTENT_TYPE, 0, 2 }, { COAP_OPT_MAX_AGE, 0, 4 }, { COAP_OPT_URI_QUERY, 1, 255 }, { COAP_OPT_ACCEPT, 0, 2 }, { COAP_OPT_TOKEN, 1, 8 }, { COAP_OPT_LOCATION_QUERY, 0, 255 }, { COAP_OPT_PROXY_URI, 1,1034 }, { COAP_OPT_OBSERVE, 0, 2 }, { COAP_OPT_BLOCK2, 0, 3 }, { COAP_OPT_BLOCK1, 0, 3 }, { COAP_OPT_BLOCK_SIZE, 0, 4 }, { 0, 0, 0 }, }; static const value_string vals_ctype[] = { { 0, "text/plain; charset=utf-8" }, { 40, "application/link-format" }, { 41, "application/xml" }, { 42, "application/octet-stream" }, { 47, "application/exi" }, { 50, "application/json" }, { 0, NULL }, }; static const char *nullstr = "(null)"; void proto_reg_handoff_coap(void); static int coap_is_str_ipv6addr(guint8 *str) { size_t len = strlen(str); int colon = 0; while (len--) { if (*str++ == ':') colon++; } return colon > 1 ? 1 : 0; } static gint coap_get_opt_uint(tvbuff_t *tvb, gint offset, gint length) { switch (length) { case 0: return 0; case 1: return (guint)tvb_get_guint8(tvb, offset); case 2: return (guint)tvb_get_ntohs(tvb, offset); case 3: return (guint)tvb_get_ntoh24(tvb, offset); case 4: return (guint)tvb_get_ntohl(tvb, offset); default: return -1; } } static gint coap_opt_check(packet_info *pinfo, proto_tree *subtree, guint opt_num, gint opt_length) { int i; for (i = 0; i < (int)(array_length(coi)); i++) { if (coi[i].type == opt_num) break; } if (i == (int)(array_length(coi))) { expert_add_info_format(pinfo, subtree, PI_MALFORMED, PI_WARN, "Invalid Option Number %d", opt_num); return -1; } if (opt_length < coi[i].min || opt_length > coi[i].max) { expert_add_info_format(pinfo, subtree, PI_MALFORMED, PI_WARN, "Invalid Option Range: %d (%d < x < %d)", opt_length, coi[i].min, coi[i].max); } return 0; } static void dissect_coap_opt_hex_string(tvbuff_t *tvb, proto_item *item, proto_tree *subtree, gint offset, gint opt_hlen, gint opt_length, int hf) { const guint8 *str; gint dp = offset + opt_hlen; if (opt_length == 0) str = nullstr; else str = tvb_bytes_to_str_punct(tvb, dp, opt_length, ' '); proto_tree_add_string(subtree, hf, tvb, dp, opt_length, str); /* add info to the head of the packet detail */ proto_item_append_text(item, ": %s", str); } static void dissect_coap_opt_uint(tvbuff_t *tvb, proto_item *head_item, proto_tree *subtree, gint offset, gint opt_hlen, gint opt_length, int hf) { guint i = 0; gint dp, len; if (opt_length == 0) { dp = offset; len = opt_hlen; i = 0; } else { dp = offset + opt_hlen; len = opt_length; i = coap_get_opt_uint(tvb, dp, len); } proto_tree_add_uint(subtree, hf, tvb, dp, len, i); /* add info to the head of the packet detail */ proto_item_append_text(head_item, ": %d", i); } static void dissect_coap_opt_uri_host(tvbuff_t *tvb, proto_item *head_item, proto_tree *subtree, gint offset, gint opt_hlen, gint opt_length) { guint8 *str = NULL; gint dp = offset + opt_hlen; str = tvb_get_ephemeral_string(tvb, dp, opt_length); proto_tree_add_string(subtree, hf_coap_opt_uri_host, tvb, dp, opt_length, str); /* add info to the head of the packet detail */ proto_item_append_text(head_item, ": %s", str); /* forming a uri-string */ g_strlcat(coap_uri_str, "coap://", sizeof(coap_uri_str)); /* * if the string looks an IPv6 address, assuming that it has * to be enclosed by brackets. */ if (coap_is_str_ipv6addr(str)) { g_strlcat(coap_uri_str, "[", sizeof(coap_uri_str)); g_strlcat(coap_uri_str, str, sizeof(coap_uri_str)); g_strlcat(coap_uri_str, "]", sizeof(coap_uri_str)); } else g_strlcat(coap_uri_str, str, sizeof(coap_uri_str)); } static void dissect_coap_opt_uri_path(tvbuff_t *tvb, proto_item *head_item, proto_tree *subtree, gint offset, gint opt_hlen, gint opt_length) { const guint8 *str = NULL; gint dp, len; g_strlcat(coap_uri_str, "/", sizeof(coap_uri_str)); if (opt_length == 0) { dp = offset; len = opt_hlen; str = nullstr; } else { dp = offset + opt_hlen; len = opt_length; str = tvb_get_ephemeral_string(tvb, dp, len); g_strlcat(coap_uri_str, str, sizeof(coap_uri_str)); } proto_tree_add_string(subtree, hf_coap_opt_uri_path, tvb, dp, len, str); /* add info to the head of the packet detail */ proto_item_append_text(head_item, ": %s", str); } static void dissect_coap_opt_uri_query(tvbuff_t *tvb, proto_item *head_item,proto_tree *subtree, gint offset, gint opt_hlen, gint opt_length) { const guint8 *str = NULL; gint dp, len; if (coap_uri_query[0] == '\0') g_strlcat(coap_uri_query, "?", sizeof(coap_uri_str)); else g_strlcat(coap_uri_query, "&", sizeof(coap_uri_str)); if (opt_length == 0) { dp = offset; len = opt_hlen; str = nullstr; } else { dp = offset + opt_hlen; len = opt_length; str = tvb_get_ephemeral_string(tvb, dp, len); g_strlcat(coap_uri_str, str, sizeof(coap_uri_str)); } proto_tree_add_string(subtree, hf_coap_opt_uri_query, tvb, dp, len, str); /* add info to the head of the packet detail */ proto_item_append_text(head_item, ": %s", str); } static void dissect_coap_opt_location_path(tvbuff_t *tvb, proto_item *head_item, proto_tree *subtree, gint offset, gint opt_hlen, gint opt_length) { const guint8 *str = NULL; gint dp, len; if (opt_length == 0) { dp = offset; len = opt_hlen; str = nullstr; } else { dp = offset + opt_hlen; len = opt_length; str = tvb_get_ephemeral_string(tvb, dp, len); } proto_tree_add_string(subtree, hf_coap_opt_location_path, tvb, dp, len, str); /* add info to the head of the packet detail */ proto_item_append_text(head_item, ": %s", str); } static void dissect_coap_opt_location_query(tvbuff_t *tvb, proto_item *head_item, proto_tree *subtree, gint offset, gint opt_hlen, gint opt_length) { const guint8 *str = NULL; gint dp, len; if (opt_length == 0) { dp = offset; len = opt_hlen; str = nullstr; } else { dp = offset + opt_hlen; len = opt_length; str = tvb_get_ephemeral_string(tvb, dp, len); } proto_tree_add_string(subtree, hf_coap_opt_location_query, tvb, dp, len, str); /* add info to the head of the packet detail */ proto_item_append_text(head_item, ": %s", str); } static void dissect_coap_opt_proxy_uri(tvbuff_t *tvb, proto_item *head_item, proto_tree *subtree, gint offset, gint opt_hlen, gint opt_length) { const guint8 *str = NULL; gint dp, len; if (opt_length == 0) { dp = offset; len = opt_hlen; str = nullstr; } else { dp = offset + opt_hlen; len = opt_length; str = tvb_get_ephemeral_string(tvb, dp, len); } proto_tree_add_string(subtree, hf_coap_opt_proxy_uri, tvb, dp, len, str); /* add info to the head of the packet detail */ proto_item_append_text(head_item, ": %s", str); } static void dissect_coap_opt_token(tvbuff_t *tvb, proto_item *head_item, proto_tree *subtree, gint offset, gint opt_hlen, gint opt_length) { gint dp = offset + opt_hlen; /* forming a token */ g_strlcat(coap_token_str, tvb_bytes_to_str_punct(tvb, dp, opt_length, ' '), sizeof(coap_token_str)); proto_tree_add_string(subtree, hf_coap_opt_token, tvb, dp, opt_length, coap_token_str); /* add info to the head of the packet detail */ proto_item_append_text(head_item, ": %s", coap_token_str); } static void dissect_coap_opt_ctype(tvbuff_t *tvb, proto_item *head_item, proto_tree *subtree, gint offset, gint opt_hlen, gint opt_length, int hf) { gint dp, len; if (opt_length == 0) { dp = offset; len = opt_hlen; coap_ctype_value = 0; } else { dp = offset + opt_hlen; len = opt_length; coap_ctype_value = coap_get_opt_uint(tvb, dp, len); } coap_ctype_str = val_to_str(coap_ctype_value, vals_ctype, "Unknown Type %d"); proto_tree_add_string(subtree, hf, tvb, dp, len, coap_ctype_str); /* add info to the head of the packet detail */ proto_item_append_text(head_item, ": %s", coap_ctype_str); } static void dissect_coap_opt_block(tvbuff_t *tvb, proto_item *head_item, proto_tree *subtree, gint offset, gint opt_hlen, gint opt_length) { guint8 val = 0; guint encoded_block_size = 0; guint block_esize; gint dp, len; gint dp2; if (opt_length == 0) { dp = offset; len = opt_hlen; coap_block_number = 0; val = 0; dp2 = dp; } else { dp = offset + opt_hlen; len = opt_length; coap_block_number = coap_get_opt_uint(tvb, dp, len) >> 4; val = tvb_get_guint8(tvb, offset + opt_length - 1) & 0x0f; dp2 = dp + opt_length - 1; } proto_tree_add_uint(subtree, hf_coap_opt_block_number, tvb, dp, len, coap_block_number); /* More flag in the end of the option */ coap_block_mflag = val & 0x08; proto_tree_add_uint(subtree, hf_coap_opt_block_mflag, tvb, dp2, 1, coap_block_mflag); /* block size */ encoded_block_size = val & 0x07; block_esize = 1 << (encoded_block_size + 4); proto_tree_add_uint_format(subtree, hf_coap_opt_block_size, tvb, dp2, 1, encoded_block_size, "Block Size: %d (%d encoded)", block_esize, encoded_block_size); /* add info to the head of the packet detail */ proto_item_append_text(head_item, ": NUM:%d, M:%d, SZX:%d", coap_block_number, coap_block_mflag, block_esize); } static void dissect_coap_opt_uri_port(tvbuff_t *tvb, proto_item *head_item, proto_tree *subtree, gint offset, gint opt_hlen, gint opt_length) { guint port = 0; char portstr[6]; gint dp, len; memset(portstr, '\0', sizeof(portstr)); if (opt_length == 0) { dp = offset; len = opt_hlen; port = 0; } else { dp = offset; len = opt_hlen; port = coap_get_opt_uint(tvb, dp, len); } proto_tree_add_uint(subtree, hf_coap_opt_uri_port, tvb, dp, len, port); proto_item_append_text(head_item, ": %d", port); /* forming a uri-string */ g_snprintf(portstr, sizeof(portstr), "%u", port); g_strlcat(coap_uri_str, ":", sizeof(coap_uri_str)); g_strlcat(coap_uri_str, portstr, sizeof(coap_uri_str)); } /* * 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_main(tvbuff_t *tvb, packet_info *pinfo, proto_tree *coap_tree, gint offset, guint8 opt_count, guint *opt_num, gint coap_length) { guint8 opt_jump; gint opt_length, tmp_length, jump_length; proto_tree *subtree = NULL; proto_item *item = NULL; gint opt_hlen, max_hlen; tvbuff_t *tvb_lenbuf = NULL; char strbuf[56]; opt_jump = tvb_get_guint8(tvb, offset); /* option jump */ /* * seciton 3.2 in coap-12: * If the Option Count field in the CoAP header is 15 and the Option * Header byte is 0xf0 (the Option Delta is 15 and the Option Length is * 0), the option is interpreted as the end-of-options marker instead of * the option with the resulting Option Number. (In other words, the * end-of-options marker always is just a single byte valued 0xf0.) * * section 3.3 in coap-12: * An Option Jump MUST be followed by an actual Option, i.e., it MUST * NOT be followed by another Option Jump or an end-of-options * indicator. A message violating this MUST be treated as an encoding * error. * Option Jumps do NOT count as Options in the Option Count field of the * header (i.e., they cannot by themselves end the Option sequence). */ switch (opt_jump) { case 0xf0: if (opt_count != 15) { expert_add_info_format(pinfo, subtree, PI_MALFORMED, PI_WARN, "end-of-options marker found, but OC isn't 15"); return -1; } proto_tree_add_string(coap_tree, hf_coap_opt_jump, tvb, offset, 1, "end-of-options marker"); return ++offset; case 0xf1: jump_length = 15; proto_tree_add_uint_format(coap_tree, hf_coap_opt_jump, tvb, offset, 1, jump_length, "Option Jump (0xf1): %d", jump_length); *opt_num += jump_length; offset++; opt_jump = tvb_get_guint8(tvb, offset); break; case 0xf2: jump_length = (tvb_get_guint8(tvb, offset + 1) + 2) * 8; proto_tree_add_uint_format(coap_tree, hf_coap_opt_jump, tvb, offset, 2, jump_length, "Option Jump (0xf2): %d", jump_length); *opt_num += jump_length; offset += 2; opt_jump = tvb_get_guint8(tvb, offset); break; case 0xf3: jump_length = (tvb_get_ntohs(tvb, offset + 1) + 258) * 8; proto_tree_add_uint_format(coap_tree, hf_coap_opt_jump, tvb, offset, 3, jump_length, "Option Jump (0xf3): %d", jump_length); *opt_num += jump_length; offset += 3; opt_jump = tvb_get_guint8(tvb, offset); break; } /* * Length: * Normally Length is a 4-bit unsigned integer allowing values of * 0-14 octets. The Length field can be extended for options with * values longer than 14 bytes by adding extension bytes. * The maximum length for an option is 1034 bytes. */ max_hlen = 4; opt_hlen = 1; opt_length = opt_jump & 0x0f; if (opt_length == 0x0f) { do { tmp_length = tvb_get_guint8(tvb, offset + opt_hlen); opt_length += tmp_length; opt_hlen++; } while (!(opt_hlen == max_hlen || tmp_length != 0xff)); } if (max_hlen < opt_hlen) { expert_add_info_format(pinfo, subtree, PI_MALFORMED, PI_WARN, "Invalid Option Length: all %d bits are set, which is not" " allowed by the spec 12", max_hlen * 8 - 4); return -1; } if (coap_length < offset) { expert_add_info_format(pinfo, subtree, PI_MALFORMED, PI_WARN, "Invalid length: coap payload length(%d) < offset(%d)", coap_length, offset); return -1; } *opt_num += ((opt_jump & 0xf0) >> 4); coap_opt_check(pinfo, subtree, *opt_num, opt_length); g_snprintf(strbuf, sizeof(strbuf), "#%u: %s", opt_count, val_to_str_const(*opt_num, vals_opt_type, *opt_num % 14 == 0 ? "No-Op" : "Unknown Option")); item = proto_tree_add_string(coap_tree, hf_coap_opt_name, tvb, offset, opt_hlen + opt_length, strbuf); subtree = proto_item_add_subtree(item, ett_coap_option); g_snprintf(strbuf, sizeof(strbuf), "Type %u, %s, %s%s", *opt_num, (*opt_num & 1) ? "Critical" : "Elective", (*opt_num & 2) ? "Unsafe" : "Safe", ((*opt_num & 0x1e) == 0x1c) ? ", NoCacheKey" : ""); proto_tree_add_string(subtree, hf_coap_opt_desc, tvb, offset, opt_hlen + opt_length, strbuf); proto_tree_add_item(subtree, hf_coap_opt_delta, tvb, offset, 1, ENC_BIG_ENDIAN); 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, 4 + ((opt_hlen - 1) * 8), opt_length, "%d", opt_length); /* offset points the next to its option header */ switch (*opt_num) { case COAP_OPT_CONTENT_TYPE: dissect_coap_opt_ctype(tvb, item, subtree, offset, opt_hlen, opt_length, hf_coap_opt_ctype); break; case COAP_OPT_MAX_AGE: dissect_coap_opt_uint(tvb, item, subtree, offset, opt_hlen, opt_length, hf_coap_opt_max_age); break; case COAP_OPT_PROXY_URI: dissect_coap_opt_proxy_uri(tvb, item, subtree, offset, opt_hlen, opt_length); break; case COAP_OPT_ETAG: dissect_coap_opt_hex_string(tvb, item, subtree, offset, opt_hlen, opt_length, hf_coap_opt_etag); break; case COAP_OPT_URI_HOST: dissect_coap_opt_uri_host(tvb, item, subtree, offset, opt_hlen, opt_length); break; case COAP_OPT_LOCATION_PATH: dissect_coap_opt_location_path(tvb, item, subtree, offset, opt_hlen, opt_length); break; case COAP_OPT_URI_PORT: dissect_coap_opt_uri_port(tvb, item, subtree, offset, opt_hlen, opt_length); break; case COAP_OPT_LOCATION_QUERY: dissect_coap_opt_location_query(tvb, item, subtree, offset, opt_hlen, opt_length); break; case COAP_OPT_URI_PATH: dissect_coap_opt_uri_path(tvb, item, subtree, offset, opt_hlen, opt_length); break; case COAP_OPT_OBSERVE: dissect_coap_opt_uint(tvb, item, subtree, offset, opt_hlen, opt_length, hf_coap_opt_observe); break; case COAP_OPT_TOKEN: dissect_coap_opt_token(tvb, item, subtree, offset, opt_hlen, opt_length); break; case COAP_OPT_ACCEPT: dissect_coap_opt_ctype(tvb, item, subtree, offset, opt_hlen, opt_length, hf_coap_opt_accept); break; case COAP_OPT_IF_MATCH: dissect_coap_opt_hex_string(tvb, item, subtree, offset, opt_hlen, opt_length, hf_coap_opt_if_match); break; case COAP_OPT_URI_QUERY: dissect_coap_opt_uri_query(tvb, item, subtree, offset, opt_hlen, opt_length); break; case COAP_OPT_BLOCK2: dissect_coap_opt_block(tvb, item, subtree, offset, opt_hlen, opt_length); break; case COAP_OPT_BLOCK1: dissect_coap_opt_block(tvb, item, subtree, offset, opt_hlen, opt_length); break; case COAP_OPT_IF_NONE_MATCH: break; case COAP_OPT_BLOCK_SIZE: dissect_coap_opt_uint(tvb, item, subtree, offset, opt_hlen, opt_length, hf_coap_opt_block_size); break; default: dissect_coap_opt_hex_string(tvb, item, subtree, offset, opt_hlen, opt_length, hf_coap_opt_unknown); break; } return offset + opt_hlen + opt_length; } /* * options dissector. * return offset pointing the next of options. (i.e. the top of the paylaod * or the end of the data. */ static int dissect_coap_options(tvbuff_t *tvb, packet_info *pinfo, proto_tree *coap_tree, gint offset, gint coap_length, guint8 opt_count) { guint opt_num = 0; int i; /* loop for dissecting options */ for (i = 1; i <= opt_count; i++) { offset = dissect_coap_options_main(tvb, pinfo, coap_tree, offset, i, &opt_num, coap_length); if (offset == -1) return -1; } return offset; } static void dissect_coap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree) { gint 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; gint coap_length = 0; /* initialize the CoAP length and the content-Format */ /* * 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_ctype_str = ""; coap_ctype_value = DEFAULT_COAP_CTYPE_VALUE; coap_root = proto_tree_add_item(parent_tree, proto_coap, tvb, offset, -1, ENC_NA); coap_tree = proto_item_add_subtree(coap_root, ett_coap); proto_tree_add_item(coap_tree, hf_coap_version, tvb, offset, 1, ENC_BIG_ENDIAN); proto_tree_add_item(coap_tree, hf_coap_ttype, tvb, offset, 1, ENC_BIG_ENDIAN); ttype = (tvb_get_guint8(tvb, offset) & 0x30) >> 4; proto_tree_add_item(coap_tree, hf_coap_opt_count, tvb, offset, 1, ENC_BIG_ENDIAN); opt_count = tvb_get_guint8(tvb, offset) & 0x0f; offset += 1; proto_tree_add_item(coap_tree, hf_coap_code, tvb, offset, 1, ENC_BIG_ENDIAN); code = tvb_get_guint8(tvb, offset); offset += 1; proto_tree_add_item(coap_tree, hf_coap_tid, tvb, offset, 2, ENC_BIG_ENDIAN); tid = tvb_get_ntohs(tvb, offset); offset += 2; /* append the header information */ proto_item_append_text(coap_tree, ", %s, %s, TID:%u", val_to_str(ttype, vals_ttype, "Unkown %d"), val_to_str(code, vals_code, "Unknown %d"), tid); /* initialize the external value */ coap_block_number = DEFAULT_COAP_BLOCK_NUMBER; coap_block_mflag = 0; coap_uri_str[0] = '\0'; coap_uri_query[0] = '\0'; coap_token_str[0] = '\0'; /* process options */ offset = dissect_coap_options(tvb, pinfo, coap_tree, offset, coap_length, opt_count); if (offset == -1) return; /* add informations to the packet list */ col_set_str(pinfo->cinfo, COL_PROTOCOL, "CoAP"); col_clear(pinfo->cinfo, COL_INFO); col_add_fstr(pinfo->cinfo, COL_INFO, "%s", val_to_str(ttype, vals_ttype_short, "Unknown %d")); col_append_fstr(pinfo->cinfo, COL_INFO, ", TID:%u", tid); col_append_fstr(pinfo->cinfo, COL_INFO, ", %s", val_to_str(code, vals_code, "Unknown %d")); if (coap_token_str[0] != '\0') col_append_fstr(pinfo->cinfo, COL_INFO, ", TKN:%s", coap_token_str); if (coap_block_number != DEFAULT_COAP_BLOCK_NUMBER) col_append_fstr(pinfo->cinfo, COL_INFO, ", %sBlock #%d", coap_block_mflag ? "" : "End of ", coap_block_number); if (coap_uri_str[0] != '\0') col_append_fstr(pinfo->cinfo, COL_INFO, ", %s", coap_uri_str); if (coap_uri_query[0] != '\0') col_append_fstr(pinfo->cinfo, COL_INFO, "%s", coap_uri_query); /* 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 str_payload[80]; /* * 5.5.2. Diagnostic Payload * * If no Content-Format option is given, the payload of responses * indicating a client or server error is a brief human-readable * diagnostic message, explaining the error situation. This diagnostic * message MUST be encoded using UTF-8 [RFC3629], more specifically * using Net-Unicode form [RFC5198]. */ if (coap_ctype_value == DEFAULT_COAP_CTYPE_VALUE) coap_ctype_str = "text/plain; charset=utf-8"; g_snprintf(str_payload, sizeof(str_payload), "Payload Content-Format: %s%s, Length: %u, offset: %u", coap_ctype_str, coap_ctype_value == DEFAULT_COAP_CTYPE_VALUE ? " (no Content-Format)" : "", payload_length, offset); proto_tree_add_string(coap_tree, hf_coap_payload_desc, tvb, offset, -1, coap_ctype_str); 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_ctype_str, payload_tvb, pinfo, payload_tree); } } /* * 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, { "Opt Count", "coap.ocount", 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_payload_desc, { "Payload Desc", "coap.opt.payload_desc", FT_STRING, BASE_NONE, NULL, 0x0, "CoAP Payload Description", HFILL } }, { &hf_coap_opt_name, { "Opt Name", "coap.opt.name", FT_STRING, BASE_NONE, NULL, 0x0, "CoAP Option Name", HFILL } }, { &hf_coap_opt_desc, { "Opt Desc", "coap.opt.desc", FT_STRING, BASE_NONE, NULL, 0x0, "CoAP Option Description", HFILL } }, { &hf_coap_opt_jump, { "Opt Jump", "coap.opt.jump", FT_UINT8, BASE_DEC, NULL, 0xf0, "CoAP Option Jump", HFILL } }, { &hf_coap_opt_delta, { "Opt Delta", "coap.opt.delta", FT_UINT8, BASE_DEC, NULL, 0xf0, "CoAP Option Delta", HFILL } }, { &hf_coap_opt_length, { "Opt Length", "coap.opt.length", FT_UINT16, BASE_DEC, NULL, 0x0, "CoAP Option Length", HFILL } }, { &hf_coap_opt_ctype, { "Content-type", "coap.opt.ctype", FT_STRING, BASE_NONE, NULL, 0x0, "CoAP Option Content Type", HFILL } }, { &hf_coap_opt_max_age, { "Max-age", "coap.opt.max_age", FT_UINT32, BASE_DEC, NULL, 0x0, "CoAP Option Max-age", HFILL } }, { &hf_coap_opt_proxy_uri, { "Proxy-Uri", "coap.opt.proxy_uri", FT_STRING, BASE_NONE, NULL, 0x0, "CoAP Option Proxy-Uri", HFILL } }, { &hf_coap_opt_etag, { "Etag", "coap.opt.etag", FT_BYTES, BASE_NONE, NULL, 0x0, "CoAP Option Etag", HFILL } }, { &hf_coap_opt_uri_host, { "Uri-Host", "coap.opt.uri_host", FT_STRING, BASE_NONE, NULL, 0x0, "CoAP Option Uri-Host", HFILL } }, { &hf_coap_opt_location_path, { "Location-Path", "coap.opt.location_path", FT_STRING, BASE_NONE, NULL, 0x0, "CoAP Option Uri-Path", HFILL } }, { &hf_coap_opt_uri_port, { "Uri-Port", "coap.opt.uri_port", FT_UINT16, BASE_DEC, NULL, 0x0, "CoAP Option Uri-Port", HFILL } }, { &hf_coap_opt_location_query, { "Location-Query", "coap.opt.location_query", FT_STRING, BASE_NONE, NULL, 0x0, "CoAP Option Uri-Query", HFILL } }, { &hf_coap_opt_uri_path, { "Uri-Path", "coap.opt.uri_path", FT_STRING, BASE_NONE, NULL, 0x0, "CoAP Option Uri-Path", HFILL } }, { &hf_coap_opt_observe, { "Lifetime", "coap.opt.subscr_lifetime", FT_INT32, BASE_DEC, NULL, 0x0, "CoAP Option Observe", HFILL } }, { &hf_coap_opt_token, { "Token", "coap.opt.token", FT_STRING, BASE_NONE, NULL, 0x0, "CoAP Option Token", HFILL } }, { &hf_coap_opt_accept, { "Accept", "coap.opt.accept", FT_STRING, BASE_NONE, NULL, 0x0, "CoAP Option Acceptable Content Type", HFILL } }, { &hf_coap_opt_if_match, { "If-Match", "coap.opt.if_match", FT_BYTES, BASE_NONE, NULL, 0x0, "CoAP Option If-Match", HFILL } }, { &hf_coap_opt_block_number, { "Block Number", "coap.opt.block_number", FT_UINT32, BASE_DEC, NULL, 0x0, "CoAP Option Block Number", HFILL } }, { &hf_coap_opt_block_mflag, { "More Flag", "coap.opt.block_mflag", FT_UINT8, BASE_DEC, NULL, 0x08, "CoAP Option Block More Size", HFILL } }, { &hf_coap_opt_block_size, { "Encoded Block Size", "coap.opt.block_size", FT_UINT8, BASE_DEC, NULL, 0x07, "CoAP Option Encoded Block Size", HFILL } }, { &hf_coap_opt_uri_query, { "Uri-Query", "coap.opt.uri_query", FT_STRING, BASE_NONE, NULL, 0x0, "CoAP Option Uri-Query", HFILL } }, { &hf_coap_opt_unknown, { "Unknown", "coap.opt.unknown", FT_STRING, BASE_NONE, NULL, 0x0, "Coap Unknown Option", 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); }