forked from osmocom/wireshark
418 lines
14 KiB
C
418 lines
14 KiB
C
/* packet-coap.c
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* Routines for COAP packet disassembly
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* Shoichi Sakane <sakane@tanu.org>
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*
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* $Id$
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* draft-core-coap-02.txt
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*
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* Wireshark - Network traffic analyzer
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* By Gerald Combs <gerald@wireshark.org>
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* Copyright 1998 Gerald Combs
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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#ifdef HAVE_CONFIG_H
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# include "config.h"
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#endif
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#include <glib.h>
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#include <epan/proto.h>
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#include <epan/packet.h>
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#include <epan/ipproto.h>
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#include <epan/asn1.h>
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#include <epan/reassemble.h>
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#include <epan/prefs.h>
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#include <epan/expert.h>
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static dissector_handle_t coap_handle;
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static dissector_table_t media_type_dissector_table;
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static int proto_coap = -1;
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static int hf_coap_version = -1;
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static int hf_coap_ttype = -1;
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static int hf_coap_opt_count = -1;
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static int hf_coap_code = -1;
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static int hf_coap_tid = -1;
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static int hf_coap_opt_type = -1;
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static int hf_coap_opt_delta = -1;
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static int hf_coap_opt_length = -1;
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static int hf_coap_opt_ctype = -1;
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static int hf_coap_opt_max_age = -1;
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static int hf_coap_opt_uri_scheme = -1;
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static int hf_coap_opt_etag = -1;
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static int hf_coap_opt_uri_authority = -1;
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static int hf_coap_opt_location = -1;
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static int hf_coap_opt_uri_path = -1;
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static int hf_coap_payload = -1;
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static gint ett_coap = -1;
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static gint ett_coap_noop = -1;
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static gint ett_coap_ctype = -1;
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static gint ett_coap_max_age = -1;
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static gint ett_coap_uri_scheme = -1;
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static gint ett_coap_etag = -1;
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static gint ett_coap_uri_authority = -1;
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static gint ett_coap_location = -1;
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static gint ett_coap_uri_path = -1;
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static gint ett_coap_payload = -1;
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/* TODO: COAP port number will be assigned by IANA after the draft become a RFC */
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#define DEFAULT_COAP_PORT 61616
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static const gchar *coap_content_type = NULL;
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static guint global_coap_port_number = DEFAULT_COAP_PORT;
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/*
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* Transaction Type
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*/
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static const value_string vals_ttype[] = {
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{ 0, "Confirmable" },
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{ 1, "Non-Confirmable" },
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{ 2, "Acknowledgement" },
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{ 3, "Reset" },
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{ 0, NULL },
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};
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/*
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* Method Code
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* Response Code
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*/
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static const value_string vals_code[] = {
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/* method code */
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{ 1, "GET" },
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{ 2, "POST" },
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{ 3, "PUT" },
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{ 4, "DELETE" },
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/* response code */
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{ 40, "100 Continue" },
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{ 80, "200 OK"},
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{ 81, "201 Created"},
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{ 124, "304 Not Modified"},
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{ 160, "400 Bad Request"},
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{ 164, "404 Not Found"},
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{ 165, "405 Method Not Allowed"},
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{ 175, "415 Unsupported Media Type"},
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{ 200, "500 Internal Server Error"},
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{ 202, "502 Bad Gateway"},
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{ 203, "503 Service Unavailable"},
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{ 204, "504 Gateway Timeout"},
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{ 0, NULL },
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};
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/*
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* Option Headers
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* No-Option must not be included in this structure, is handled in the function
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* of the dissector, especially.
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*/
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#define COAP_OPT_CONTENT_TYPE 1
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#define COAP_OPT_MAX_AGE 2
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#define COAP_OPT_ETAG 4
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#define COAP_OPT_URI_AUTHORITY 5
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#define COAP_OPT_LOCATION 6
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#define COAP_OPT_URI_PATH 9
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static const value_string vals_opt_type[] = {
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{ COAP_OPT_CONTENT_TYPE, "Content-Type" },
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{ COAP_OPT_MAX_AGE, "Max-age"},
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{ COAP_OPT_ETAG, "Etag"},
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{ COAP_OPT_URI_AUTHORITY, "Uri-Authority"},
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{ COAP_OPT_LOCATION, "Location"},
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{ COAP_OPT_URI_PATH, "Uri-Path"},
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{ 0, NULL },
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};
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static const value_string vals_ctype[] = {
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{ 0, "text/plain (UTF-8)" },
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{ 1, "text/xml (UTF-8)" },
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{ 2, "text/csv (UTF-8)" },
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{ 3, "text/html (UTF-8)" },
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{ 21, "image/gif" },
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{ 22, "image/jpeg" },
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{ 23, "image/png" },
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{ 24, "image/tiff" },
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{ 25, "audio/raw" },
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{ 26, "video/raw" },
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{ 40, "application/link-format" },
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{ 41, "application/xml" },
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{ 42, "application/octet-stream" },
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{ 43, "application/rdf+xml" },
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{ 44, "application/soap+xml" },
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{ 45, "application/atom+xml" },
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{ 46, "application/xmpp+xml" },
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{ 47, "application/exi" },
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{ 48, "application/x-bxml" },
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{ 49, "application/fastinfoset" },
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{ 50, "application/soap+fastinfoset" },
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{ 51, "application/json" },
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{ 0, NULL },
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};
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void proto_reg_handoff_coap(void);
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/*
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* dissector for each option of COAP.
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* return the total length of the option including the header (e.g. delta and length).
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*/
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static int
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dissect_coap_options(tvbuff_t *tvb, proto_tree *coap_tree, proto_tree *parent_tree _U_, int offset, guint8 *opt_code)
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{
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guint8 opt_delta;
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guint32 opt_ctype = 0;
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guint opt_max_age = 0;
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gint opt_length;
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proto_tree *subtree = NULL;
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proto_item *item = NULL;
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int opt_hlen = 0;
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opt_delta = (tvb_get_guint8(tvb, offset) & 0xf0) >> 4;
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*opt_code += opt_delta;
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opt_length = (tvb_get_guint8(tvb, offset) & 0x0f);
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opt_hlen = 1;
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if (opt_length == 0x0f) {
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opt_length += tvb_get_guint8(tvb, offset + 1);
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opt_hlen = 2;
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}
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item = proto_tree_add_uint_format(coap_tree, hf_coap_opt_type, tvb, offset, 1, *opt_code,
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"Option (Length: %u) %s",
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opt_length, val_to_str(*opt_code, vals_opt_type, "Unknown Option Type"));
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offset += opt_hlen;
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/* if opt_code is a multiple of 14, that means the option is a noop option */
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if (*opt_code % 14 == 0) {
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subtree = proto_item_add_subtree(item, ett_coap_noop);
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proto_tree_add_text(subtree, tvb, 0, 0, "No-Op option");
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} else {
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switch (*opt_code) {
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case COAP_OPT_CONTENT_TYPE:
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subtree = proto_item_add_subtree(item, ett_coap_ctype);
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opt_ctype = tvb_get_guint8(tvb, offset);
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coap_content_type = val_to_str(opt_ctype, vals_code, "Unknown %d");
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proto_tree_add_item(subtree, hf_coap_opt_ctype, tvb, offset, opt_length, FALSE);
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break;
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case COAP_OPT_MAX_AGE:
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subtree = proto_item_add_subtree(item, ett_coap_max_age);
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switch (opt_length) {
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case 1:
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opt_max_age = (guint)tvb_get_guint8(tvb, offset);
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break;
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case 2:
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opt_max_age = (guint)tvb_get_ntohs(tvb, offset);
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break;
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case 3:
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opt_max_age = (guint)tvb_get_ntoh24(tvb, offset);
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break;
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case 4:
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opt_max_age = (guint)tvb_get_ntohl(tvb, offset);
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break;
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default:
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proto_tree_add_text(subtree, tvb, 0, 0, "Invalid length: %d", opt_length);
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break;
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}
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proto_tree_add_item(subtree, hf_coap_opt_max_age, tvb, offset, opt_length, FALSE);
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break;
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case COAP_OPT_ETAG:
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subtree = proto_item_add_subtree(item, ett_coap_etag);
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proto_tree_add_item(subtree, hf_coap_opt_etag, tvb, offset, opt_length, FALSE);
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break;
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case COAP_OPT_URI_AUTHORITY:
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subtree = proto_item_add_subtree(item, ett_coap_uri_authority);
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proto_tree_add_item(subtree, hf_coap_opt_uri_authority, tvb, offset, opt_length, FALSE);
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break;
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case COAP_OPT_LOCATION:
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subtree = proto_item_add_subtree(item, ett_coap_location);
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proto_tree_add_item(subtree, hf_coap_opt_location, tvb, offset, opt_length, FALSE);
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break;
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case COAP_OPT_URI_PATH:
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subtree = proto_item_add_subtree(item, ett_coap_uri_path);
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proto_tree_add_item(subtree, hf_coap_opt_uri_path, tvb, offset, opt_length, FALSE);
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break;
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default:
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proto_tree_add_text(subtree, tvb, 0, 0, "Unkown Option Type");
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}
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}
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return offset + opt_length;
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}
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static void
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dissect_coap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree)
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{
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guint offset = 0;
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proto_item *coap_root = NULL;
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proto_tree *coap_tree = NULL;
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guint8 ttype = 0;
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guint8 opt_count = 0;
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guint8 code = 0;
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guint16 tid = 0;
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guint coap_length = pinfo->iplen - pinfo->iphdrlen - 8;
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guint8 opt_code = 0;
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col_set_str(pinfo->cinfo, COL_PROTOCOL, "COAP");
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col_clear(pinfo->cinfo, COL_INFO);
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if (!parent_tree)
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return;
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coap_root = proto_tree_add_item(parent_tree, proto_coap, tvb, offset, -1, FALSE);
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coap_tree = proto_item_add_subtree(coap_root, ett_coap);
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proto_tree_add_item(coap_tree, hf_coap_version, tvb, offset, 1, FALSE);
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proto_tree_add_item(coap_tree, hf_coap_ttype, tvb, offset, 1, FALSE);
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ttype = (tvb_get_guint8(tvb, offset) & 0x30) >> 4;
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col_add_fstr(pinfo->cinfo, COL_INFO, "%s", val_to_str(ttype, vals_ttype, "Unknown %d"));
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proto_tree_add_item(coap_tree, hf_coap_opt_count, tvb, offset, 1, FALSE);
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opt_count = tvb_get_guint8(tvb, offset) & 0x0f;
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offset += 1;
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proto_tree_add_item(coap_tree, hf_coap_code, tvb, offset, 1, FALSE);
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code = tvb_get_guint8(tvb, offset);
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col_append_fstr(pinfo->cinfo, COL_INFO, ", %s", val_to_str(code, vals_code, "Unknown %d"));
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offset += 1;
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proto_tree_add_item(coap_tree, hf_coap_tid, tvb, offset, 2, FALSE);
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tid = tvb_get_ntohs(tvb, offset);
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offset += 2;
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/* append the header information */
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proto_item_append_text(coap_tree, ", TID: %u, Length: %u", tid, coap_length);
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/* dissect the options */
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while (opt_count--) {
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offset = dissect_coap_options(tvb, coap_tree, parent_tree, offset, &opt_code);
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if (coap_length < offset) {
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/* error */
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proto_tree_add_text(coap_tree, tvb, 0, 0, "invalid length: coap_length(%d) < offset(%d)", coap_length, offset);
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return;
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}
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}
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/* dissect the payload */
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if (coap_length > offset) {
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proto_tree *payload_tree = NULL;
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proto_item *payload_item = NULL;
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tvbuff_t *payload_tvb;
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guint payload_length = coap_length - offset;
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char *ctype_str_default = "";
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gboolean result = TRUE;
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/*
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* TODO:
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* currently, coap_content_type is used to distinguish whether
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* the content-type was specified. If we need to properly handle
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* the case when the type was unknown, we need another flag.
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*/
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if (coap_content_type == NULL) {
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/* default: coap-02 section 3.2.1 */
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/* when it's NULL, "text/plain" is set anyway */
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coap_content_type = "text/plain";
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ctype_str_default = "(as default)";
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}
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/*
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* TODO: should the content type be canonicalized,
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* currently assuming it be small ?
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*/
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payload_item = proto_tree_add_text(coap_tree, tvb, offset, -1, "Payload Content-Type: %s%s, Length: %u, offset: %u",
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coap_content_type, ctype_str_default, payload_length, offset);
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payload_tree = proto_item_add_subtree(payload_item, ett_coap_payload);
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payload_tvb = tvb_new_subset(tvb, offset, payload_length, payload_length);
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result = dissector_try_string(media_type_dissector_table, coap_content_type, payload_tvb, pinfo, payload_tree);
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if (!result) {
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/* TODO: call heuristic dissector */
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;
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}
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}
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}
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/*
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* Protocol initialization
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*/
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void
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proto_register_coap(void)
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{
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static hf_register_info hf[] = {
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{ &hf_coap_version, { "Version", "coap.version", FT_UINT8, BASE_DEC, NULL, 0xc0, "COAP Version", HFILL }},
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{ &hf_coap_ttype, { "Type", "coap.type", FT_UINT8, BASE_DEC, VALS(&vals_ttype), 0x30, "COAP Transaction Type", HFILL }},
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{ &hf_coap_opt_count, { "Option Count", "coap.optcount", FT_UINT8, BASE_DEC, NULL, 0x0f, "COAP Option Count", HFILL }},
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{ &hf_coap_code, { "Code", "coap.code", FT_UINT8, BASE_DEC, VALS(&vals_code), 0x0, "COAP Method or Response Code", HFILL }},
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{ &hf_coap_tid, { "Transaction ID", "coap.tid", FT_UINT16, BASE_DEC, NULL, 0x0, "COAP Transaction ID", HFILL }},
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{ &hf_coap_opt_type, { "Option Type", "coap.opt.opt_type", FT_UINT8, BASE_DEC, VALS(&vals_opt_type), 0x0, "COAP Option Type", HFILL }},
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{ &hf_coap_opt_delta, { "Option Delta", "coap.opt.delta", FT_UINT8, BASE_DEC, NULL, 0x0, "COAP Option Delta", HFILL }},
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{ &hf_coap_opt_length, { "Option Length", "coap.opt.length", FT_UINT16, BASE_DEC, NULL, 0x0, "COAP Option Length", HFILL }},
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{ &hf_coap_opt_ctype, { "Content-type", "coap.opt.ctype", FT_UINT8, BASE_DEC, VALS(&vals_ctype), 0x0, "COAP Media Type", HFILL }},
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{ &hf_coap_opt_max_age, { "Max-age", "coap.opt.maxage", FT_UINT32, BASE_DEC, NULL, 0x0, "COAP Max-age", HFILL }},
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{ &hf_coap_opt_uri_scheme, { "Uri-Scheme", "coap.opt.uri_scheme", FT_STRING, BASE_NONE, NULL, 0x0, "COAP Max-age", HFILL }},
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{ &hf_coap_opt_etag, { "Etag", "coap.opt.etag", FT_BYTES, BASE_NONE, NULL, 0x0, "COAP Etag", HFILL }},
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{ &hf_coap_opt_uri_authority, { "Uri-Authority", "coap.opt.uri_auth", FT_STRING, BASE_NONE, NULL, 0x0, "COAP Uri-Authority", HFILL }},
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{ &hf_coap_opt_location, { "Location", "coap.opt.location", FT_STRING, BASE_NONE, NULL, 0x0, "COAP Location", HFILL }},
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{ &hf_coap_opt_uri_path, { "Uri-Path", "coap.opt.uri_path", FT_STRING, BASE_NONE, NULL, 0x0, "COAP Uri-Path", HFILL }},
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{ &hf_coap_payload, { "Payload", "coap.opt.payload", FT_BYTES, BASE_NONE, NULL, 0x0, "COAP Payload", HFILL }},
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};
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static gint *ett[] = {
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&ett_coap,
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&ett_coap_ctype,
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&ett_coap_max_age,
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&ett_coap_uri_scheme,
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&ett_coap_etag,
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&ett_coap_uri_authority,
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&ett_coap_location,
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&ett_coap_uri_path,
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&ett_coap_payload,
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};
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module_t *coap_module;
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proto_coap = proto_register_protocol("Constrained Application Protocol", "COAP", "coap");
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proto_register_field_array(proto_coap, hf, array_length(hf));
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proto_register_subtree_array(ett, array_length(ett));
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register_dissector("coap", dissect_coap, proto_coap);
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/* Register our configuration options */
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coap_module = prefs_register_protocol (proto_coap, proto_reg_handoff_coap);
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prefs_register_uint_preference (coap_module, "udp_port",
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"COAP port number",
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"Port number used for COAP traffic",
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10, &global_coap_port_number);
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}
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void
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proto_reg_handoff_coap(void)
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{
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static gboolean coap_prefs_initialized = FALSE;
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static guint coap_port_number;
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if (!coap_prefs_initialized) {
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coap_handle = find_dissector("coap");
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media_type_dissector_table = find_dissector_table("media_type");
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coap_prefs_initialized = TRUE;
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} else {
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dissector_delete("udp.port", coap_port_number, coap_handle);
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dissector_delete("tcp.port", coap_port_number, coap_handle);
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}
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coap_port_number = global_coap_port_number;
|
|
dissector_add("udp.port", coap_port_number, coap_handle);
|
|
dissector_add("tcp.port", coap_port_number, coap_handle);
|
|
}
|