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wireshark/epan/dissectors/packet-coap.c

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/* 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 <sakane@tanu.org>
*
* Changes for draft-ietf-core-coap-17.txt
* Hauke Mehrtens <hauke@hauke-m.de>
*
* $Id$
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* 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 <glib.h>
#include <epan/packet.h>
#include <epan/prefs.h>
#include <expert.h>
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_token_len = -1;
static int hf_coap_token = -1;
static int hf_coap_code = -1;
static int hf_coap_mid = -1;
static int hf_coap_payload = -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_delta = -1;
static int hf_coap_opt_delta_ext = -1;
static int hf_coap_opt_length = -1;
static int hf_coap_opt_length_ext = -1;
static int hf_coap_opt_end_marker = -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_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;
static expert_field ei_coap_invalid_option_number = EI_INIT;
static expert_field ei_coap_invalid_option_range = EI_INIT;
static expert_field ei_coap_option_length_bad = EI_INIT;
/* 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_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_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_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, &ei_coap_invalid_option_number,
"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, &ei_coap_invalid_option_range,
"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_length, int hf)
{
const guint8 *str;
if (opt_length == 0)
str = nullstr;
else
str = tvb_bytes_to_str_punct(tvb, offset, opt_length, ' ');
proto_tree_add_item(subtree, hf, tvb, offset, opt_length, ENC_NA);
/* 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_length, int hf)
{
guint i = 0;
if (opt_length != 0) {
i = coap_get_opt_uint(tvb, offset, opt_length);
}
proto_tree_add_uint(subtree, hf, tvb, offset, opt_length, 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_length)
{
guint8 *str = NULL;
str = tvb_get_string(wmem_packet_scope(), tvb, offset, opt_length);
proto_tree_add_string(subtree, hf_coap_opt_uri_host, tvb, offset, 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_length)
{
const guint8 *str = NULL;
g_strlcat(coap_uri_str, "/", sizeof(coap_uri_str));
if (opt_length == 0) {
str = nullstr;
} else {
str = tvb_get_string(wmem_packet_scope(), tvb, offset, opt_length);
g_strlcat(coap_uri_str, str, sizeof(coap_uri_str));
}
proto_tree_add_string(subtree, hf_coap_opt_uri_path, tvb, offset, opt_length, 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_length)
{
const guint8 *str = NULL;
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) {
str = nullstr;
} else {
str = tvb_get_string(wmem_packet_scope(), tvb, offset, opt_length);
g_strlcat(coap_uri_str, str, sizeof(coap_uri_str));
}
proto_tree_add_string(subtree, hf_coap_opt_uri_query, tvb, offset, opt_length, 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_length)
{
const guint8 *str = NULL;
if (opt_length == 0) {
str = nullstr;
} else {
str = tvb_get_string(wmem_packet_scope(), tvb, offset, opt_length);
}
proto_tree_add_string(subtree, hf_coap_opt_location_path, tvb, offset, opt_length, 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_length)
{
const guint8 *str = NULL;
if (opt_length == 0) {
str = nullstr;
} else {
str = tvb_get_string(wmem_packet_scope(), tvb, offset, opt_length);
}
proto_tree_add_string(subtree, hf_coap_opt_location_query, tvb, offset, opt_length, 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_length)
{
const guint8 *str = NULL;
if (opt_length == 0) {
str = nullstr;
} else {
str = tvb_get_string(wmem_packet_scope(), tvb, offset, opt_length);
}
proto_tree_add_string(subtree, hf_coap_opt_proxy_uri, tvb, offset, opt_length, str);
/* add info to the head of the packet detail */
proto_item_append_text(head_item, ": %s", str);
}
static void
dissect_coap_opt_ctype(tvbuff_t *tvb, proto_item *head_item, proto_tree *subtree, gint offset, gint opt_length, int hf)
{
if (opt_length == 0) {
coap_ctype_value = 0;
} else {
coap_ctype_value = coap_get_opt_uint(tvb, offset, opt_length);
}
coap_ctype_str = val_to_str(coap_ctype_value, vals_ctype, "Unknown Type %d");
proto_tree_add_string(subtree, hf, tvb, offset, opt_length, 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_length)
{
guint8 val = 0;
guint encoded_block_size = 0;
guint block_esize;
if (opt_length == 0) {
coap_block_number = 0;
val = 0;
} else {
coap_block_number = coap_get_opt_uint(tvb, offset, opt_length) >> 4;
val = tvb_get_guint8(tvb, offset + opt_length - 1) & 0x0f;
}
proto_tree_add_uint(subtree, hf_coap_opt_block_number,
tvb, offset, opt_length, 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, offset + opt_length - 1, 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, offset + opt_length - 1, 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_length)
{
guint port = 0;
char portstr[6];
memset(portstr, '\0', sizeof(portstr));
if (opt_length != 0) {
port = coap_get_opt_uint(tvb, offset, opt_length);
}
proto_tree_add_uint(subtree, hf_coap_opt_uri_port, tvb, offset, opt_length, 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, opt_length_ext, opt_delta, opt_delta_ext;
gint opt_length_ext_off = 0;
gint8 opt_length_ext_len = 0;
gint opt_delta_ext_off = 0;
gint8 opt_delta_ext_len = 0;
gint orig_offset = offset;
proto_tree *subtree = NULL;
proto_item *item = NULL;
char strbuf[56];
opt_jump = tvb_get_guint8(tvb, offset);
offset++;
/*
* seciton 3.1 in coap-17:
* Option Delta: 4-bit unsigned integer. A value between 0 and 12
* indicates the Option Delta. Three values are reserved for special
* constructs:
*
* 13: An 8-bit unsigned integer follows the initial byte and
* indicates the Option Delta minus 13.
*
* 14: A 16-bit unsigned integer in network byte order follows the
* initial byte and indicates the Option Delta minus 269.
*
* 15: Reserved for the Payload Marker. If the field is set to this
* value but the entire byte is not the payload marker, this MUST
* be processed as a message format error.
*/
switch (opt_jump & 0xf0) {
case 0xd0:
opt_delta_ext = tvb_get_guint8(tvb, offset);
opt_delta_ext_off = offset;
opt_delta_ext_len = 1;
offset++;
opt_delta = 13;
opt_delta += opt_delta_ext;
break;
case 0xe0:
opt_delta_ext = coap_get_opt_uint(tvb, offset, 2);
opt_delta_ext_off = offset;
opt_delta_ext_len = 2;
offset += 2;
opt_delta = 269;
opt_delta += opt_delta_ext;
break;
case 0xf0:
expert_add_info_format(pinfo, coap_tree, &ei_coap_option_length_bad,
"end-of-options marker found, but option length isn't 15");
return -1;
default:
opt_delta = ((opt_jump & 0xf0) >> 4);
break;
}
*opt_num += opt_delta;
/*
* seciton 3.1 in coap-17:
* Option Length: 4-bit unsigned integer. A value between 0 and 12
* indicates the length of the Option Value, in bytes. Three values
* are reserved for special constructs:
*
* 13: An 8-bit unsigned integer precedes the Option Value and
* indicates the Option Length minus 13.
*
* 14: A 16-bit unsigned integer in network byte order precedes the
* Option Value and indicates the Option Length minus 269.
*
* 15: Reserved for future use. If the field is set to this value,
* it MUST be processed as a message format error.
*/
switch (opt_jump & 0x0f) {
case 0x0d:
opt_length_ext = tvb_get_guint8(tvb, offset);
opt_length_ext_off = offset;
opt_length_ext_len = 1;
offset++;
opt_length = 13;
opt_length += opt_length_ext;
break;
case 0x0e:
opt_length_ext = coap_get_opt_uint(tvb, offset, 2);
opt_length_ext_off = offset;
opt_length_ext_len = 2;
offset += 2;
opt_length = 269;
opt_length += opt_length_ext;
break;
case 0x0f:
expert_add_info_format(pinfo, coap_tree, &ei_coap_option_length_bad,
"end-of-options marker found, but option delta isn't 15");
return -1;
default:
opt_length = (opt_jump & 0x0f);
break;
}
if (offset + opt_length > coap_length) {
expert_add_info_format(pinfo, coap_tree, &ei_coap_option_length_bad,
"option longer than the package");
return -1;
}
coap_opt_check(pinfo, coap_tree, *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, orig_offset, offset - orig_offset + 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, orig_offset, offset - orig_offset + opt_length, strbuf);
proto_tree_add_item(subtree, hf_coap_opt_delta, tvb, orig_offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(subtree, hf_coap_opt_length, tvb, orig_offset, 1, ENC_BIG_ENDIAN);
if (opt_delta_ext_off && opt_delta_ext_len)
proto_tree_add_item(subtree, hf_coap_opt_delta_ext, tvb, opt_delta_ext_off, opt_delta_ext_len, ENC_BIG_ENDIAN);
if (opt_length_ext_off && opt_length_ext_len)
proto_tree_add_item(subtree, hf_coap_opt_length_ext, tvb, opt_length_ext_off, opt_length_ext_len, ENC_BIG_ENDIAN);
/* 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_length, hf_coap_opt_ctype);
break;
case COAP_OPT_MAX_AGE:
dissect_coap_opt_uint(tvb, item, subtree, offset,
opt_length, hf_coap_opt_max_age);
break;
case COAP_OPT_PROXY_URI:
dissect_coap_opt_proxy_uri(tvb, item, subtree, offset,
opt_length);
break;
case COAP_OPT_ETAG:
dissect_coap_opt_hex_string(tvb, item, subtree, offset,
opt_length, hf_coap_opt_etag);
break;
case COAP_OPT_URI_HOST:
dissect_coap_opt_uri_host(tvb, item, subtree, offset,
opt_length);
break;
case COAP_OPT_LOCATION_PATH:
dissect_coap_opt_location_path(tvb, item, subtree, offset,
opt_length);
break;
case COAP_OPT_URI_PORT:
dissect_coap_opt_uri_port(tvb, item, subtree, offset,
opt_length);
break;
case COAP_OPT_LOCATION_QUERY:
dissect_coap_opt_location_query(tvb, item, subtree, offset,
opt_length);
break;
case COAP_OPT_URI_PATH:
dissect_coap_opt_uri_path(tvb, item, subtree, offset,
opt_length);
break;
case COAP_OPT_OBSERVE:
dissect_coap_opt_uint(tvb, item, subtree, offset,
opt_length, hf_coap_opt_observe);
break;
case COAP_OPT_ACCEPT:
dissect_coap_opt_ctype(tvb, item, subtree, offset,
opt_length, hf_coap_opt_accept);
break;
case COAP_OPT_IF_MATCH:
dissect_coap_opt_hex_string(tvb, item, subtree, offset,
opt_length, hf_coap_opt_if_match);
break;
case COAP_OPT_URI_QUERY:
dissect_coap_opt_uri_query(tvb, item, subtree, offset,
opt_length);
break;
case COAP_OPT_BLOCK2:
dissect_coap_opt_block(tvb, item, subtree, offset,
opt_length);
break;
case COAP_OPT_BLOCK1:
dissect_coap_opt_block(tvb, item, subtree, offset,
opt_length);
break;
case COAP_OPT_IF_NONE_MATCH:
break;
case COAP_OPT_BLOCK_SIZE:
dissect_coap_opt_uint(tvb, item, subtree, offset,
opt_length, hf_coap_opt_block_size);
break;
default:
dissect_coap_opt_hex_string(tvb, item, subtree, offset,
opt_length, hf_coap_opt_unknown);
break;
}
return offset + 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)
{
guint opt_num = 0;
int i;
guint8 endmarker;
/* loop for dissecting options */
for (i = 1; offset < coap_length; i++) {
offset = dissect_coap_options_main(tvb, pinfo, coap_tree,
offset, i, &opt_num, coap_length);
if (offset == -1)
return -1;
if (offset >= coap_length)
break;
endmarker = tvb_get_guint8(tvb, offset);
if (endmarker == 0xff) {
proto_tree_add_item(coap_tree, hf_coap_opt_end_marker, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
break;
}
}
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 token_len = 0;
guint8 code = 0;
guint16 mid = 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_token_len, tvb, offset, 1, ENC_BIG_ENDIAN);
token_len = 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_mid, tvb, offset, 2, ENC_BIG_ENDIAN);
mid = tvb_get_ntohs(tvb, offset);
offset += 2;
/* append the header information */
proto_item_append_text(coap_tree, ", %s, %s, MID:%u", val_to_str(ttype, vals_ttype, "Unkown %d"), val_to_str(code, vals_code, "Unknown %d"), mid);
/* 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';
if (token_len > 0)
{
g_strlcat(coap_token_str, tvb_bytes_to_str_punct(tvb, offset, token_len, ' '), sizeof(coap_token_str));
proto_tree_add_item(coap_tree, hf_coap_token,
tvb, offset, token_len, ENC_NA);
offset += token_len;
}
/* process options */
offset = dissect_coap_options(tvb, pinfo, coap_tree, offset, coap_length);
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, ", MID:%u", mid);
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;
const char *coap_ctype_str_dis;
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",
coap_ctype_str, coap_ctype_value == DEFAULT_COAP_CTYPE_VALUE ?
" (no Content-Format)" : "", payload_length);
payload_item = proto_tree_add_string(coap_tree, hf_coap_payload,
tvb, offset, payload_length,
str_payload);
payload_tree = proto_item_add_subtree(payload_item, ett_coap_payload);
proto_tree_add_string(payload_tree, hf_coap_payload_desc, tvb, offset, -1, coap_ctype_str);
payload_tvb = tvb_new_subset(tvb, offset, payload_length, payload_length);
if (coap_ctype_value == DEFAULT_COAP_CTYPE_VALUE || coap_ctype_value == 0) {
coap_ctype_str_dis = "text/plain";
} else {
coap_ctype_str_dis = coap_ctype_str;
}
dissector_try_string(media_type_dissector_table, coap_ctype_str_dis,
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,
NULL, HFILL }
},
{ &hf_coap_ttype,
{ "Type", "coap.type",
FT_UINT8, BASE_DEC, VALS(vals_ttype), 0x30,
NULL, HFILL }
},
{ &hf_coap_token_len,
{ "Token Length", "coap.token_len",
FT_UINT8, BASE_DEC, NULL, 0x0f,
NULL, HFILL }
},
{ &hf_coap_token,
{ "Token", "coap.token",
FT_BYTES, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
{ &hf_coap_code,
{ "Code", "coap.code",
FT_UINT8, BASE_DEC, VALS(vals_code), 0x0,
NULL, HFILL }
},
{ &hf_coap_mid,
{ "Message ID", "coap.mid",
FT_UINT16, BASE_DEC, NULL, 0x0,
NULL, HFILL }
},
{ &hf_coap_payload,
{ "Payload", "coap.payload",
FT_STRING, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
{ &hf_coap_payload_desc,
{ "Payload Desc", "coap.opt.payload_desc",
FT_STRING, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
{ &hf_coap_opt_name,
{ "Opt Name", "coap.opt.name",
FT_STRING, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
{ &hf_coap_opt_desc,
{ "Opt Desc", "coap.opt.desc",
FT_STRING, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
{ &hf_coap_opt_delta,
{ "Opt Delta", "coap.opt.delta",
FT_UINT8, BASE_DEC, NULL, 0xf0,
NULL, HFILL }
},
{ &hf_coap_opt_delta_ext,
{ "Opt Delta extended", "coap.opt.delta_ext",
FT_UINT16, BASE_DEC, NULL, 0x0,
NULL, HFILL }
},
{ &hf_coap_opt_length,
{ "Opt Length", "coap.opt.length",
FT_UINT8, BASE_DEC, NULL, 0x0f,
"CoAP Option Length", HFILL }
},
{ &hf_coap_opt_length_ext,
{ "Opt Length extended", "coap.opt.length_ext",
FT_UINT16, BASE_DEC, NULL, 0x0,
NULL, HFILL }
},
{ &hf_coap_opt_end_marker,
{ "End of options marker", "coap.opt.end_marker",
FT_UINT8, BASE_DEC, NULL, 0x00,
NULL, HFILL }
},
{ &hf_coap_opt_ctype,
{ "Content-type", "coap.opt.ctype",
FT_STRING, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
{ &hf_coap_opt_max_age,
{ "Max-age", "coap.opt.max_age",
FT_UINT32, BASE_DEC, NULL, 0x0,
NULL, HFILL }
},
{ &hf_coap_opt_proxy_uri,
{ "Proxy-Uri", "coap.opt.proxy_uri",
FT_STRING, BASE_NONE, NULL, 0x0,
NULL, 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,
NULL, HFILL }
},
{ &hf_coap_opt_location_path,
{ "Location-Path", "coap.opt.location_path",
FT_STRING, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
{ &hf_coap_opt_uri_port,
{ "Uri-Port", "coap.opt.uri_port",
FT_UINT16, BASE_DEC, NULL, 0x0,
NULL, HFILL }
},
{ &hf_coap_opt_location_query,
{ "Location-Query", "coap.opt.location_query",
FT_STRING, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
{ &hf_coap_opt_uri_path,
{ "Uri-Path", "coap.opt.uri_path",
FT_STRING, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
{ &hf_coap_opt_observe,
{ "Lifetime", "coap.opt.subscr_lifetime",
FT_UINT32, BASE_DEC, NULL, 0x0,
NULL, HFILL }
},
{ &hf_coap_opt_accept,
{ "Accept", "coap.opt.accept",
FT_STRING, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
{ &hf_coap_opt_if_match,
{ "If-Match", "coap.opt.if_match",
FT_BYTES, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
{ &hf_coap_opt_block_number,
{ "Block Number", "coap.opt.block_number",
FT_UINT32, BASE_DEC, NULL, 0x0,
NULL, HFILL }
},
{ &hf_coap_opt_block_mflag,
{ "More Flag", "coap.opt.block_mflag",
FT_UINT8, BASE_DEC, NULL, 0x08,
NULL, HFILL }
},
{ &hf_coap_opt_block_size,
{ "Encoded Block Size", "coap.opt.block_size",
FT_UINT8, BASE_DEC, NULL, 0x07,
NULL, HFILL }
},
{ &hf_coap_opt_uri_query,
{ "Uri-Query", "coap.opt.uri_query",
FT_STRING, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
{ &hf_coap_opt_unknown,
{ "Unknown", "coap.opt.unknown",
FT_BYTES, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
};
static gint *ett[] = {
&ett_coap,
&ett_coap_option,
&ett_coap_payload,
};
static ei_register_info ei[] = {
{ &ei_coap_invalid_option_number, { "coap.invalid_option_number", PI_MALFORMED, PI_WARN, "Invalid Option Number", EXPFILL }},
{ &ei_coap_invalid_option_range, { "coap.invalid_option_range", PI_MALFORMED, PI_WARN, "Invalid Option Range", EXPFILL }},
{ &ei_coap_option_length_bad, { "coap.option_length_bad", PI_MALFORMED, PI_WARN, "Option length bad", EXPFILL }},
};
module_t *coap_module;
expert_module_t* expert_coap;
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));
expert_coap = expert_register_protocol(proto_coap);
expert_register_field_array(expert_coap, ei, array_length(ei));
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);
}
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