nes-proj/os/net/app-layer/coap/coap-engine.c
Niclas Finne 24e24b8edc coap: added check for block offset overflow in block2 requests.
The block offset is stored in a signed variable in calls to CoAP handlers and
too large block offsets will overflow into negative values.

Thanks to Bruno Melo for reporting this issue.
2018-04-13 14:18:21 +02:00

520 lines
20 KiB
C

/*
* Copyright (c) 2013, Institute for Pervasive Computing, ETH Zurich
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* This file is part of the Contiki operating system.
*/
/**
* \file
* CoAP implementation Engine.
* \author
* Matthias Kovatsch <kovatsch@inf.ethz.ch>
*/
/**
* \addtogroup coap
* @{
*/
#include "coap-engine.h"
#include "sys/cc.h"
#include "lib/list.h"
#include <stdio.h>
#include <stdlib.h>
#include <inttypes.h>
#include <string.h>
/* Log configuration */
#include "coap-log.h"
#define LOG_MODULE "coap-eng"
#define LOG_LEVEL LOG_LEVEL_COAP
static void process_callback(coap_timer_t *t);
/*
* To be called by HTTP/COAP server as a callback function when a new service
* request appears. This function dispatches the corresponding CoAP service.
*/
static int invoke_coap_resource_service(coap_message_t *request,
coap_message_t *response,
uint8_t *buffer, uint16_t buffer_size,
int32_t *offset);
/*---------------------------------------------------------------------------*/
/*- Variables ---------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
LIST(coap_handlers);
LIST(coap_resource_services);
static uint8_t is_initialized = 0;
/*---------------------------------------------------------------------------*/
/*- CoAP service handlers---------------------------------------------------*/
/*---------------------------------------------------------------------------*/
void
coap_add_handler(coap_handler_t *handler)
{
list_add(coap_handlers, handler);
}
/*---------------------------------------------------------------------------*/
void
coap_remove_handler(coap_handler_t *handler)
{
list_remove(coap_handlers, handler);
}
/*---------------------------------------------------------------------------*/
coap_handler_status_t
coap_call_handlers(coap_message_t *request, coap_message_t *response,
uint8_t *buffer, uint16_t buffer_size, int32_t *offset)
{
coap_handler_status_t status;
coap_handler_t *r;
for(r = list_head(coap_handlers); r != NULL; r = r->next) {
if(r->handler) {
status = r->handler(request, response, buffer, buffer_size, offset);
if(status != COAP_HANDLER_STATUS_CONTINUE) {
/* Request handled. */
/* Check response code before doing observe! */
if(request->code == COAP_GET) {
coap_observe_handler(NULL, request, response);
}
return status;
}
}
}
return COAP_HANDLER_STATUS_CONTINUE;
}
/*---------------------------------------------------------------------------*/
static CC_INLINE coap_handler_status_t
call_service(coap_message_t *request, coap_message_t *response,
uint8_t *buffer, uint16_t buffer_size, int32_t *offset)
{
coap_handler_status_t status;
status = coap_call_handlers(request, response, buffer, buffer_size, offset);
if(status != COAP_HANDLER_STATUS_CONTINUE) {
return status;
}
status = invoke_coap_resource_service(request, response, buffer, buffer_size, offset);
if(status != COAP_HANDLER_STATUS_CONTINUE) {
return status;
}
coap_set_status_code(response, NOT_FOUND_4_04);
return COAP_HANDLER_STATUS_CONTINUE;
}
/*---------------------------------------------------------------------------*/
/*- Server Part -------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
/* the discover resource is automatically included for CoAP */
extern coap_resource_t res_well_known_core;
/*---------------------------------------------------------------------------*/
/*- Internal API ------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
int
coap_receive(const coap_endpoint_t *src,
uint8_t *payload, uint16_t payload_length)
{
/* static declaration reduces stack peaks and program code size */
static coap_message_t message[1]; /* this way the message can be treated as pointer as usual */
static coap_message_t response[1];
coap_transaction_t *transaction = NULL;
coap_handler_status_t status;
coap_status_code = coap_parse_message(message, payload, payload_length);
coap_set_src_endpoint(message, src);
if(coap_status_code == NO_ERROR) {
/*TODO duplicates suppression, if required by application */
LOG_DBG(" Parsed: v %u, t %u, tkl %u, c %u, mid %u\n", message->version,
message->type, message->token_len, message->code, message->mid);
LOG_DBG(" URL:");
LOG_DBG_COAP_STRING(message->uri_path, message->uri_path_len);
LOG_DBG_("\n");
LOG_DBG(" Payload: ");
LOG_DBG_COAP_STRING((const char *)message->payload, message->payload_len);
LOG_DBG_("\n");
/* handle requests */
if(message->code >= COAP_GET && message->code <= COAP_DELETE) {
/* use transaction buffer for response to confirmable request */
if((transaction = coap_new_transaction(message->mid, src))) {
uint32_t block_num = 0;
uint16_t block_size = COAP_MAX_BLOCK_SIZE;
uint32_t block_offset = 0;
int32_t new_offset = 0;
/* prepare response */
if(message->type == COAP_TYPE_CON) {
/* reliable CON requests are answered with an ACK */
coap_init_message(response, COAP_TYPE_ACK, CONTENT_2_05,
message->mid);
} else {
/* unreliable NON requests are answered with a NON as well */
coap_init_message(response, COAP_TYPE_NON, CONTENT_2_05,
coap_get_mid());
/* mirror token */
}
if(message->token_len) {
coap_set_token(response, message->token, message->token_len);
/* get offset for blockwise transfers */
}
if(coap_get_header_block2
(message, &block_num, NULL, &block_size, &block_offset)) {
LOG_DBG("Blockwise: block request %"PRIu32" (%u/%u) @ %"PRIu32" bytes\n",
block_num, block_size, COAP_MAX_BLOCK_SIZE, block_offset);
block_size = MIN(block_size, COAP_MAX_BLOCK_SIZE);
new_offset = block_offset;
}
if(new_offset < 0) {
LOG_DBG("Blockwise: block request offset overflow\n");
coap_status_code = BAD_OPTION_4_02;
coap_error_message = "BlockOutOfScope";
status = COAP_HANDLER_STATUS_CONTINUE;
} else {
/* call CoAP framework and check if found and allowed */
status = call_service(message, response,
transaction->message + COAP_MAX_HEADER_SIZE,
block_size, &new_offset);
}
if(status != COAP_HANDLER_STATUS_CONTINUE) {
if(coap_status_code == NO_ERROR) {
/* TODO coap_handle_blockwise(request, response, start_offset, end_offset); */
/* resource is unaware of Block1 */
if(coap_is_option(message, COAP_OPTION_BLOCK1)
&& response->code < BAD_REQUEST_4_00
&& !coap_is_option(response, COAP_OPTION_BLOCK1)) {
LOG_DBG("Block1 NOT IMPLEMENTED\n");
coap_status_code = NOT_IMPLEMENTED_5_01;
coap_error_message = "NoBlock1Support";
/* client requested Block2 transfer */
} else if(coap_is_option(message, COAP_OPTION_BLOCK2)) {
/* unchanged new_offset indicates that resource is unaware of blockwise transfer */
if(new_offset == block_offset) {
LOG_DBG("Blockwise: unaware resource with payload length %u/%u\n",
response->payload_len, block_size);
if(block_offset >= response->payload_len) {
LOG_DBG("handle_incoming_data(): block_offset >= response->payload_len\n");
response->code = BAD_OPTION_4_02;
coap_set_payload(response, "BlockOutOfScope", 15); /* a const char str[] and sizeof(str) produces larger code size */
} else {
coap_set_header_block2(response, block_num,
response->payload_len -
block_offset > block_size,
block_size);
coap_set_payload(response,
response->payload + block_offset,
MIN(response->payload_len -
block_offset, block_size));
} /* if(valid offset) */
/* resource provides chunk-wise data */
} else {
LOG_DBG("Blockwise: blockwise resource, new offset %"PRId32"\n",
new_offset);
coap_set_header_block2(response, block_num,
new_offset != -1
|| response->payload_len >
block_size, block_size);
if(response->payload_len > block_size) {
coap_set_payload(response, response->payload,
block_size);
}
} /* if(resource aware of blockwise) */
/* Resource requested Block2 transfer */
} else if(new_offset != 0) {
LOG_DBG("Blockwise: no block option for blockwise resource, using block size %u\n",
COAP_MAX_BLOCK_SIZE);
coap_set_header_block2(response, 0, new_offset != -1,
COAP_MAX_BLOCK_SIZE);
coap_set_payload(response, response->payload,
MIN(response->payload_len,
COAP_MAX_BLOCK_SIZE));
} /* blockwise transfer handling */
} /* no errors/hooks */
/* successful service callback */
/* serialize response */
}
if(coap_status_code == NO_ERROR) {
if((transaction->message_len = coap_serialize_message(response,
transaction->
message)) ==
0) {
coap_status_code = PACKET_SERIALIZATION_ERROR;
}
}
} else {
coap_status_code = SERVICE_UNAVAILABLE_5_03;
coap_error_message = "NoFreeTraBuffer";
} /* if(transaction buffer) */
/* handle responses */
} else {
if(message->type == COAP_TYPE_CON && message->code == 0) {
LOG_INFO("Received Ping\n");
coap_status_code = PING_RESPONSE;
} else if(message->type == COAP_TYPE_ACK) {
/* transactions are closed through lookup below */
LOG_DBG("Received ACK\n");
} else if(message->type == COAP_TYPE_RST) {
LOG_INFO("Received RST\n");
/* cancel possible subscriptions */
coap_remove_observer_by_mid(src, message->mid);
}
if((transaction = coap_get_transaction_by_mid(message->mid))) {
/* free transaction memory before callback, as it may create a new transaction */
coap_resource_response_handler_t callback = transaction->callback;
void *callback_data = transaction->callback_data;
coap_clear_transaction(transaction);
/* check if someone registered for the response */
if(callback) {
callback(callback_data, message);
}
}
/* if(ACKed transaction) */
transaction = NULL;
#if COAP_OBSERVE_CLIENT
/* if observe notification */
if((message->type == COAP_TYPE_CON || message->type == COAP_TYPE_NON)
&& coap_is_option(message, COAP_OPTION_OBSERVE)) {
LOG_DBG("Observe [%"PRId32"]\n", message->observe);
coap_handle_notification(src, message);
}
#endif /* COAP_OBSERVE_CLIENT */
} /* request or response */
} /* parsed correctly */
/* if(parsed correctly) */
if(coap_status_code == NO_ERROR) {
if(transaction) {
coap_send_transaction(transaction);
}
} else if(coap_status_code == MANUAL_RESPONSE) {
LOG_DBG("Clearing transaction for manual response");
coap_clear_transaction(transaction);
} else {
coap_message_type_t reply_type = COAP_TYPE_ACK;
LOG_WARN("ERROR %u: %s\n", coap_status_code, coap_error_message);
coap_clear_transaction(transaction);
if(coap_status_code == PING_RESPONSE) {
coap_status_code = 0;
reply_type = COAP_TYPE_RST;
} else if(coap_status_code >= 192) {
/* set to sendable error code */
coap_status_code = INTERNAL_SERVER_ERROR_5_00;
/* reuse input buffer for error message */
}
coap_init_message(message, reply_type, coap_status_code,
message->mid);
coap_set_payload(message, coap_error_message,
strlen(coap_error_message));
coap_sendto(src, payload, coap_serialize_message(message, payload));
}
/* if(new data) */
return coap_status_code;
}
/*---------------------------------------------------------------------------*/
void
coap_engine_init(void)
{
/* avoid initializing twice */
if(is_initialized) {
LOG_DBG("already running - double initialization?\n");
return;
}
is_initialized = 1;
LOG_INFO("Starting CoAP engine...\n");
list_init(coap_handlers);
list_init(coap_resource_services);
coap_activate_resource(&res_well_known_core, ".well-known/core");
coap_transport_init();
coap_init_connection();
}
/*---------------------------------------------------------------------------*/
/**
* \brief Makes a resource available under the given URI path
* \param resource A pointer to a resource implementation
* \param path The URI path string for this resource
*
* The resource implementation must be imported first using the
* extern keyword. The build system takes care of compiling every
* *.c file in the ./resources/ sub-directory (see example Makefile).
*/
void
coap_activate_resource(coap_resource_t *resource, const char *path)
{
coap_periodic_resource_t *periodic;
resource->url = path;
list_add(coap_resource_services, resource);
LOG_INFO("Activating: %s\n", resource->url);
/* Only add periodic resources with a periodic_handler and a period > 0. */
if(resource->flags & IS_PERIODIC && resource->periodic
&& resource->periodic->periodic_handler
&& resource->periodic->period) {
LOG_DBG("Periodic resource: %p (%s)\n", resource->periodic, path);
periodic = resource->periodic;
coap_timer_set_callback(&periodic->periodic_timer, process_callback);
coap_timer_set_user_data(&periodic->periodic_timer, resource);
coap_timer_set(&periodic->periodic_timer, periodic->period);
}
}
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
/*- Internal API ------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
coap_resource_t *
coap_get_first_resource(void)
{
return list_head(coap_resource_services);
}
/*---------------------------------------------------------------------------*/
coap_resource_t *
coap_get_next_resource(coap_resource_t *resource)
{
return list_item_next(resource);
}
/*---------------------------------------------------------------------------*/
static int
invoke_coap_resource_service(coap_message_t *request, coap_message_t *response,
uint8_t *buffer, uint16_t buffer_size,
int32_t *offset)
{
uint8_t found = 0;
uint8_t allowed = 1;
coap_resource_t *resource = NULL;
const char *url = NULL;
int url_len, res_url_len;
url_len = coap_get_header_uri_path(request, &url);
for(resource = list_head(coap_resource_services);
resource; resource = resource->next) {
/* if the web service handles that kind of requests and urls matches */
res_url_len = strlen(resource->url);
if((url_len == res_url_len
|| (url_len > res_url_len
&& (resource->flags & HAS_SUB_RESOURCES)
&& url[res_url_len] == '/'))
&& strncmp(resource->url, url, res_url_len) == 0) {
coap_resource_flags_t method = coap_get_method_type(request);
found = 1;
LOG_INFO("/%s, method %u, resource->flags %u\n", resource->url,
(uint16_t)method, resource->flags);
if((method & METHOD_GET) && resource->get_handler != NULL) {
/* call handler function */
resource->get_handler(request, response, buffer, buffer_size, offset);
} else if((method & METHOD_POST) && resource->post_handler != NULL) {
/* call handler function */
resource->post_handler(request, response, buffer, buffer_size,
offset);
} else if((method & METHOD_PUT) && resource->put_handler != NULL) {
/* call handler function */
resource->put_handler(request, response, buffer, buffer_size, offset);
} else if((method & METHOD_DELETE) && resource->delete_handler != NULL) {
/* call handler function */
resource->delete_handler(request, response, buffer, buffer_size,
offset);
} else {
allowed = 0;
coap_set_status_code(response, METHOD_NOT_ALLOWED_4_05);
}
break;
}
}
if(!found) {
coap_set_status_code(response, NOT_FOUND_4_04);
} else if(allowed) {
/* final handler for special flags */
if(resource->flags & IS_OBSERVABLE) {
coap_observe_handler(resource, request, response);
}
}
return found & allowed;
}
/*---------------------------------------------------------------------------*/
/* This callback occurs when t is expired */
static void
process_callback(coap_timer_t *t)
{
coap_resource_t *resource;
resource = coap_timer_get_user_data(t);
if(resource != NULL && (resource->flags & IS_PERIODIC)
&& resource->periodic != NULL && resource->periodic->period) {
LOG_DBG("Periodic: timer expired for /%s (period: %"PRIu32")\n",
resource->url, resource->periodic->period);
if(!is_initialized) {
/* CoAP has not yet been initialized. */
} else if(resource->periodic->periodic_handler) {
/* Call the periodic_handler function. */
resource->periodic->periodic_handler();
}
coap_timer_set(t, resource->periodic->period);
}
}
/*---------------------------------------------------------------------------*/
/** @} */