RIOT-OS/RIOT
RIOT-OS/RIOT
1
0
Fork 0
mirror of https://github.com/RIOT-OS/RIOT.git synced 2024-12-29 04:50:03 +01:00
Code Releases Activity
d759d2d18b
RIOT/sys/net/application_layer/gcoap/gcoap.c
Hendrik van Essen 226dce01bf examples/gcoap: add IPv4 support
2022-10-18 10:59:43 +02:00

1802 lines
64 KiB
C
Raw Blame History

/*
* Copyright (c) 2015-2020 Ken Bannister. All rights reserved.
* 2019 Freie Universität Berlin
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @ingroup net_gcoap
* @{
*
* @file
* @brief GNRC's implementation of CoAP protocol
*
* Runs a thread (_pid) to manage request/response messaging.
*
* @author Ken Bannister <kb2ma@runbox.com>
* @author Hauke Petersen <hauke.petersen@fu-berlin.de>
*/
#include <errno.h>
#include <stdint.h>
#include <stdatomic.h>
#include <string.h>
#include "assert.h"
#include "net/coap.h"
#include "net/gcoap.h"
#include "net/gcoap/forward_proxy.h"
#include "nanocoap_internal.h"
#include "net/nanocoap/cache.h"
#include "net/sock/async/event.h"
#include "net/sock/util.h"
#include "mutex.h"
#include "random.h"
#include "thread.h"
#include "ztimer.h"
#if IS_USED(MODULE_GCOAP_DTLS)
#include "net/sock/dtls.h"
#include "net/credman.h"
#include "net/dsm.h"
#endif
#define ENABLE_DEBUG 0
#include "debug.h"
/* Sentinel value indicating that no immediate response is required */
#define NO_IMMEDIATE_REPLY (-1)
/* End of the range to pick a random timeout */
#define TIMEOUT_RANGE_END (CONFIG_COAP_ACK_TIMEOUT_MS * CONFIG_COAP_RANDOM_FACTOR_1000 / 1000)
/* Internal functions */
static void *_event_loop(void *arg);
static void _on_sock_udp_evt(sock_udp_t *sock, sock_async_flags_t type, void *arg);
static void _process_coap_pdu(gcoap_socket_t *sock, sock_udp_ep_t *remote, sock_udp_aux_tx_t *aux,
uint8_t *buf, size_t len, bool truncated);
static int _tl_init_coap_socket(gcoap_socket_t *sock, gcoap_socket_type_t type);
static ssize_t _tl_send(gcoap_socket_t *sock, const void *data, size_t len,
const sock_udp_ep_t *remote, sock_udp_aux_tx_t *aux);
static ssize_t _tl_authenticate(gcoap_socket_t *sock, const sock_udp_ep_t *remote,
uint32_t timeout);
static ssize_t _well_known_core_handler(coap_pkt_t* pdu, uint8_t *buf, size_t len,
coap_request_ctx_t *ctx);
static void _cease_retransmission(gcoap_request_memo_t *memo);
static size_t _handle_req(gcoap_socket_t *sock, coap_pkt_t *pdu, uint8_t *buf,
size_t len, sock_udp_ep_t *remote);
static void _expire_request(gcoap_request_memo_t *memo);
static void _find_req_memo(gcoap_request_memo_t **memo_ptr, coap_pkt_t *pdu,
const sock_udp_ep_t *remote, bool by_mid);
static int _find_resource(gcoap_socket_type_t tl_type,
coap_pkt_t *pdu,
const coap_resource_t **resource_ptr,
gcoap_listener_t **listener_ptr);
static int _find_observer(sock_udp_ep_t **observer, sock_udp_ep_t *remote);
static int _find_obs_memo(gcoap_observe_memo_t **memo, sock_udp_ep_t *remote,
coap_pkt_t *pdu);
static void _find_obs_memo_resource(gcoap_observe_memo_t **memo,
const coap_resource_t *resource);
static nanocoap_cache_entry_t *_cache_lookup_memo(gcoap_request_memo_t *cache_key);
static void _cache_process(gcoap_request_memo_t *memo,
coap_pkt_t *pdu);
static ssize_t _cache_build_response(nanocoap_cache_entry_t *ce, coap_pkt_t *pdu,
uint8_t *buf, size_t len);
static void _receive_from_cache_cb(void *arg);
static int _request_matcher_default(gcoap_listener_t *listener,
const coap_resource_t **resource,
coap_pkt_t *pdu);
#if IS_USED(MODULE_GCOAP_DTLS)
static void _on_sock_dtls_evt(sock_dtls_t *sock, sock_async_flags_t type, void *arg);
static void _dtls_free_up_session(void *arg);
#endif
/* Internal variables */
const coap_resource_t _default_resources[] = {
{ "/.well-known/core", COAP_GET, _well_known_core_handler, NULL },
};
static gcoap_listener_t _default_listener = {
&_default_resources[0],
ARRAY_SIZE(_default_resources),
GCOAP_SOCKET_TYPE_UNDEF,
NULL,
NULL,
_request_matcher_default
};
/* Container for the state of gcoap itself */
typedef struct {
mutex_t lock; /* Shares state attributes safely */
gcoap_listener_t *listeners; /* List of registered listeners */
gcoap_request_memo_t open_reqs[CONFIG_GCOAP_REQ_WAITING_MAX];
/* Storage for open requests; if first
byte of an entry is zero, the entry
is available */
atomic_uint next_message_id; /* Next message ID to use */
sock_udp_ep_t observers[CONFIG_GCOAP_OBS_CLIENTS_MAX];
/* Observe clients; allows reuse for
observe memos */
gcoap_observe_memo_t observe_memos[CONFIG_GCOAP_OBS_REGISTRATIONS_MAX];
/* Observed resource registrations */
uint8_t resend_bufs[CONFIG_GCOAP_RESEND_BUFS_MAX][CONFIG_GCOAP_PDU_BUF_SIZE];
/* Buffers for PDU for request resends;
if first byte of an entry is zero,
the entry is available */
} gcoap_state_t;
static gcoap_state_t _coap_state = {
.listeners = &_default_listener,
};
static kernel_pid_t _pid = KERNEL_PID_UNDEF;
static char _msg_stack[GCOAP_STACK_SIZE];
static event_queue_t _queue;
static uint8_t _listen_buf[CONFIG_GCOAP_PDU_BUF_SIZE];
static sock_udp_t _sock_udp;
static event_callback_t _receive_from_cache;
#if IS_USED(MODULE_GCOAP_DTLS)
/* DTLS variables and definitions */
#define SOCK_DTLS_CLIENT_TAG (2)
static sock_udp_t _sock_dtls_base;
static sock_dtls_t _sock_dtls;
static kernel_pid_t _auth_waiting_thread;
static event_timeout_t _dtls_session_free_up_tmout;
static event_callback_t _dtls_session_free_up_tmout_cb;
#endif
/* Event loop for gcoap _pid thread. */
static void *_event_loop(void *arg)
{
(void)arg;
sock_udp_ep_t local;
memset(&local, 0, sizeof(sock_udp_ep_t));
/* FIXME: Once the problems with IPv4/IPv6 dual stack use in RIOT are fixed, adapt these lines
* (and e.g. use AF_UNSPEC) */
#ifdef SOCK_HAS_IPV4
local.family = AF_INET;
#endif
#ifdef SOCK_HAS_IPV6
local.family = AF_INET6;
#endif
local.netif = SOCK_ADDR_ANY_NETIF;
local.port = CONFIG_GCOAP_PORT;
int res = sock_udp_create(&_sock_udp, &local, NULL, 0);
if (res < 0) {
DEBUG("gcoap: cannot create sock: %d\n", res);
return 0;
}
event_queue_init(&_queue);
sock_udp_event_init(&_sock_udp, &_queue, _on_sock_udp_evt, NULL);
if (IS_USED(MODULE_GCOAP_DTLS)) {
#if IS_USED(MODULE_GCOAP_DTLS)
local.port = CONFIG_GCOAPS_PORT;
if (sock_udp_create(&_sock_dtls_base, &local, NULL, 0)) {
DEBUG("gcoap: error creating DTLS transport sock\n");
return 0;
}
if (sock_dtls_create(&_sock_dtls, &_sock_dtls_base,
CREDMAN_TAG_EMPTY,
SOCK_DTLS_1_2, SOCK_DTLS_SERVER) < 0) {
DEBUG("gcoap: error creating DTLS sock\n");
sock_udp_close(&_sock_dtls_base);
return 0;
}
sock_dtls_event_init(&_sock_dtls, &_queue, _on_sock_dtls_evt,
NULL);
#endif
}
event_loop(&_queue);
return 0;
}
#if IS_USED(MODULE_GCOAP_DTLS)
/* Handles DTLS socket events from the event queue */
static void _on_sock_dtls_evt(sock_dtls_t *sock, sock_async_flags_t type, void *arg) {
(void)arg;
gcoap_socket_t socket = { .type = GCOAP_SOCKET_TYPE_DTLS, .socket.dtls = sock};
if (type & SOCK_ASYNC_CONN_RECV) {
ssize_t res = sock_dtls_recv(sock, &socket.ctx_dtls_session,
_listen_buf, sizeof(_listen_buf),
CONFIG_GCOAP_DTLS_HANDSHAKE_TIMEOUT_MSEC);
if (res != -SOCK_DTLS_HANDSHAKE) {
DEBUG("gcoap: could not establish DTLS session: %zd\n", res);
sock_dtls_session_destroy(sock, &socket.ctx_dtls_session);
return;
}
dsm_state_t prev_state = dsm_store(sock, &socket.ctx_dtls_session,
SESSION_STATE_ESTABLISHED, false);
/* If session is already stored and the state was SESSION_STATE_HANDSHAKE
before, the handshake has been initiated internally by a gcoap client request
and another thread is waiting for the handshake. Send message to the
waiting thread to inform about established session */
if (prev_state == SESSION_STATE_HANDSHAKE) {
msg_t msg = { .type = DTLS_EVENT_CONNECTED };
msg_send(&msg, _auth_waiting_thread);
} else if (prev_state == NO_SPACE) {
/* No space in session management. Should not happen. If it occurs,
we lost track of sessions */
DEBUG("gcoap: no space in session management. We lost track of sessions!");
sock_dtls_session_destroy(sock, &socket.ctx_dtls_session);
}
/* If not enough session slots left: set timeout to free up session */
uint8_t minimum_free = CONFIG_GCOAP_DTLS_MINIMUM_AVAILABLE_SESSIONS;
if (dsm_get_num_available_slots() < minimum_free)
{
uint32_t timeout = CONFIG_GCOAP_DTLS_MINIMUM_AVAILABLE_SESSIONS_TIMEOUT_MSEC;
event_callback_init(&_dtls_session_free_up_tmout_cb,
_dtls_free_up_session, NULL);
event_timeout_ztimer_init(&_dtls_session_free_up_tmout, ZTIMER_MSEC, &_queue,
&_dtls_session_free_up_tmout_cb.super);
event_timeout_set(&_dtls_session_free_up_tmout, timeout);
}
}
if (type & SOCK_ASYNC_CONN_FIN) {
if (sock_dtls_get_event_session(sock, &socket.ctx_dtls_session)) {
/* Session is already destroyed, only remove it from dsm */
dsm_remove(sock, &socket.ctx_dtls_session);
} else {
puts("gcoap: A session was closed, but the corresponding session " \
"could not be retrieved from the socket!");
return;
}
sock_udp_ep_t ep;
sock_dtls_session_get_udp_ep(&socket.ctx_dtls_session, &ep);
/* Remove all memos of the concerned session. TODO: oberservable memos! */
for (int i = 0; i < CONFIG_GCOAP_REQ_WAITING_MAX; i++) {
if (_coap_state.open_reqs[i].state == GCOAP_MEMO_UNUSED) {
continue;
}
gcoap_request_memo_t *memo = &_coap_state.open_reqs[i];
if (sock_udp_ep_equal(&memo->remote_ep, &ep)) {
_expire_request(memo);
event_timeout_clear(&memo->resp_evt_tmout);
}
}
}
if (type & SOCK_ASYNC_MSG_RECV) {
ssize_t res = sock_dtls_recv(sock, &socket.ctx_dtls_session, _listen_buf,
sizeof(_listen_buf), 0);
if (res <= 0) {
DEBUG("gcoap: DTLS recv failure: %d\n", (int)res);
return;
}
sock_udp_ep_t ep;
sock_dtls_session_get_udp_ep(&socket.ctx_dtls_session, &ep);
/* Truncated DTLS messages would already have gotten lost at verification */
_process_coap_pdu(&socket, &ep, NULL, _listen_buf, res, false);
}
}
/* Timeout function to free up a session when too many session slots are occupied */
static void _dtls_free_up_session(void *arg) {
(void)arg;
sock_dtls_session_t session;
uint8_t minimum_free = CONFIG_GCOAP_DTLS_MINIMUM_AVAILABLE_SESSIONS;
if (dsm_get_num_available_slots() < minimum_free) {
if (dsm_get_least_recently_used_session(&_sock_dtls, &session) != -1) {
/* free up session */
dsm_remove(&_sock_dtls, &session);
sock_dtls_session_destroy(&_sock_dtls, &session);
}
}
}
#endif /* MODULE_GCOAP_DTLS */
/* Handles UDP socket events from the event queue. */
static void _on_sock_udp_evt(sock_udp_t *sock, sock_async_flags_t type, void *arg)
{
(void)arg;
sock_udp_ep_t remote;
if (type & SOCK_ASYNC_MSG_RECV) {
void *stackbuf;
void *buf_ctx = NULL;
bool truncated = false;
size_t cursor = 0;
sock_udp_aux_rx_t aux_in = {
.flags = SOCK_AUX_GET_LOCAL,
};
/* The zero-copy _buf API is not used to its full potential here -- we
* still copy out data in what is a manual version of sock_udp_recv,
* but this gives the direly needed overflow information.
*
* A version that actually doesn't copy would vastly change the way
* gcoap passes the buffer to be read from and written into to the
* handler. Also, given that neither nanocoap nor the handler expects
* to gather scattered data, it'd need to rely on the data coming in a
* single slice (but that may be a realistic assumption).
*/
while (true) {
ssize_t res = sock_udp_recv_buf_aux(sock, &stackbuf, &buf_ctx, 0, &remote, &aux_in);
if (res < 0) {
DEBUG("gcoap: udp recv failure: %d\n", (int)res);
return;
}
if (res == 0) {
break;
}
if (cursor + res > sizeof(_listen_buf)) {
res = sizeof(_listen_buf) - cursor;
truncated = true;
}
memcpy(&_listen_buf[cursor], stackbuf, res);
cursor += res;
}
/* make sure we reply with the same address that the request was destined for */
sock_udp_aux_tx_t aux_out = {
.flags = SOCK_AUX_SET_LOCAL,
.local = aux_in.local,
};
gcoap_socket_t socket = {
.type = GCOAP_SOCKET_TYPE_UDP,
.socket.udp = sock,
};
_process_coap_pdu(&socket, &remote, &aux_out, _listen_buf, cursor, truncated);
}
}
/* Processes and evaluates the coap pdu */
static void _process_coap_pdu(gcoap_socket_t *sock, sock_udp_ep_t *remote, sock_udp_aux_tx_t *aux,
uint8_t *buf, size_t len, bool truncated)
{
coap_pkt_t pdu;
gcoap_request_memo_t *memo = NULL;
/* Code paths that necessitate a response on the message layer can set a
* response type here (COAP_TYPE_RST or COAP_TYPE_ACK). If set, at the end
* of the function there will be
* * that value will be put in the code field,
* * token length cleared,
* * code set to EMPTY, and
* * the message is returned with the rest of its header intact.
*/
int8_t messagelayer_emptyresponse_type = NO_IMMEDIATE_REPLY;
ssize_t res = coap_parse(&pdu, buf, len);
if (res < 0) {
DEBUG("gcoap: parse failure: %d\n", (int)res);
/* If a response, can't clear memo, but it will timeout later.
*
* There are *some* error cases in which we could continue (eg. all
* sorts of "packet ends mid-options" in truncated cases, and maybe
* also when the maximum option count is exceeded to at least respond
* with Bad Request), but these would likely require incompatible
* changes to nanocoap.
*/
return;
}
if (coap_get_type(&pdu) == COAP_TYPE_RST) {
DEBUG("gcoap: received RST, expiring potentially existing memo\n");
_find_req_memo(&memo, &pdu, remote, true);
if (memo) {
event_timeout_clear(&memo->resp_evt_tmout);
_expire_request(memo);
}
}
/* validate class and type for incoming */
switch (coap_get_code_class(&pdu)) {
/* incoming request or empty */
case COAP_CLASS_REQ:
if (coap_get_code_raw(&pdu) == COAP_CODE_EMPTY) {
/* ping request */
if (coap_get_type(&pdu) == COAP_TYPE_CON) {
messagelayer_emptyresponse_type = COAP_TYPE_RST;
DEBUG("gcoap: Answering empty CON request with RST\n");
} else if (coap_get_type(&pdu) == COAP_TYPE_ACK) {
_find_req_memo(&memo, &pdu, remote, true);
if ((memo != NULL) && (memo->send_limit != GCOAP_SEND_LIMIT_NON)) {
DEBUG("gcoap: empty ACK processed, stopping retransmissions\n");
_cease_retransmission(memo);
} else {
DEBUG("gcoap: empty ACK matches no known CON, ignoring\n");
}
} else {
DEBUG("gcoap: Ignoring empty non-CON request\n");
}
}
/* normal request */
else if (coap_get_type(&pdu) == COAP_TYPE_NON
|| coap_get_type(&pdu) == COAP_TYPE_CON) {
size_t pdu_len;
if (truncated) {
/* TBD: Set a Size1 */
pdu_len = gcoap_response(&pdu, _listen_buf, sizeof(_listen_buf),
COAP_CODE_REQUEST_ENTITY_TOO_LARGE);
} else {
pdu_len = _handle_req(sock, &pdu, _listen_buf,
sizeof(_listen_buf), remote);
}
if (pdu_len > 0) {
ssize_t bytes = _tl_send(sock, _listen_buf, pdu_len, remote, aux);
if (bytes <= 0) {
DEBUG("gcoap: send response failed: %d\n", (int)bytes);
}
}
}
else {
DEBUG("gcoap: illegal request type: %u\n", coap_get_type(&pdu));
}
break;
/* incoming response */
case COAP_CLASS_SUCCESS:
case COAP_CLASS_CLIENT_FAILURE:
case COAP_CLASS_SERVER_FAILURE:
_find_req_memo(&memo, &pdu, remote, false);
if (memo) {
switch (coap_get_type(&pdu)) {
case COAP_TYPE_CON:
messagelayer_emptyresponse_type = COAP_TYPE_ACK;
DEBUG("gcoap: Answering CON response with ACK\n");
/* fall through */
case COAP_TYPE_NON:
case COAP_TYPE_ACK:
if (memo->resp_evt_tmout.queue) {
event_timeout_clear(&memo->resp_evt_tmout);
}
memo->state = truncated ? GCOAP_MEMO_RESP_TRUNC : GCOAP_MEMO_RESP;
if (IS_USED(MODULE_NANOCOAP_CACHE)) {
nanocoap_cache_entry_t *ce = NULL;
if ((pdu.hdr->code == COAP_CODE_VALID) &&
(ce = _cache_lookup_memo(memo))) {
/* update max_age from response and send cached response */
uint32_t max_age = 60;
coap_opt_get_uint(&pdu, COAP_OPT_MAX_AGE, &max_age);
ce->max_age = ztimer_now(ZTIMER_SEC) + max_age;
/* copy all options and possible payload from the cached response
* to the new response */
assert((uint8_t *)pdu.hdr == &_listen_buf[0]);
if (_cache_build_response(ce, &pdu, _listen_buf,
sizeof(_listen_buf)) < 0) {
memo->state = GCOAP_MEMO_ERR;
}
if (ce->truncated) {
memo->state = GCOAP_MEMO_RESP_TRUNC;
}
}
/* TODO: resend request if VALID but no cache entry? */
else if ((pdu.hdr->code != COAP_CODE_VALID)) {
_cache_process(memo, &pdu);
}
}
if (memo->resp_handler) {
memo->resp_handler(memo, &pdu, remote);
}
if (memo->send_limit >= 0) { /* if confirmable */
*memo->msg.data.pdu_buf = 0; /* clear resend PDU buffer */
}
memo->state = GCOAP_MEMO_UNUSED;
break;
default:
DEBUG("gcoap: illegal response type: %u\n", coap_get_type(&pdu));
break;
}
}
else {
DEBUG("gcoap: msg not found for ID: %u\n", coap_get_id(&pdu));
if (coap_get_type(&pdu) == COAP_TYPE_CON) {
/* we might run into this if an ACK to a sender got lost
* see https://datatracker.ietf.org/doc/html/rfc7252#section-5.3.2 */
messagelayer_emptyresponse_type = COAP_TYPE_RST;
DEBUG("gcoap: Answering unknown CON response with RST to "
"shut up sender\n");
}
}
break;
default:
DEBUG("gcoap: illegal code class: %u\n", coap_get_code_class(&pdu));
}
if (messagelayer_emptyresponse_type != NO_IMMEDIATE_REPLY) {
coap_hdr_set_type(pdu.hdr, (uint8_t)messagelayer_emptyresponse_type);
coap_hdr_set_code(pdu.hdr, COAP_CODE_EMPTY);
/* Set the token length to 0, preserving the CoAP version as it was and
* the empty message type that was just set.
*
* FIXME: Introduce an internal function to set or truncate the token
* */
pdu.hdr->ver_t_tkl &= 0xf0;
ssize_t bytes = _tl_send(sock, buf, sizeof(coap_hdr_t), remote, aux);
if (bytes <= 0) {
DEBUG("gcoap: empty response failed: %d\n", (int)bytes);
}
}
}
/* Handles response timeout for a request; resend confirmable if needed. */
static void _on_resp_timeout(void *arg) {
gcoap_request_memo_t *memo = (gcoap_request_memo_t *)arg;
/* no retries remaining */
if ((memo->send_limit == GCOAP_SEND_LIMIT_NON) || (memo->send_limit == 0)) {
_expire_request(memo);
}
/* reduce retries remaining, double timeout and resend */
else {
memo->send_limit--;
#ifdef CONFIG_GCOAP_NO_RETRANS_BACKOFF
unsigned i = 0;
#else
unsigned i = CONFIG_COAP_MAX_RETRANSMIT - memo->send_limit;
#endif
uint32_t timeout = (uint32_t)CONFIG_COAP_ACK_TIMEOUT_MS << i;
#if CONFIG_COAP_RANDOM_FACTOR_1000 > 1000
uint32_t end = (uint32_t)TIMEOUT_RANGE_END << i;
timeout = random_uint32_range(timeout, end);
#endif
event_timeout_set(&memo->resp_evt_tmout, timeout);
if (memo->state == GCOAP_MEMO_WAIT) {
/* See _cease_retransmission: Still going through the timeouts and
* rescheduling, but not actually sending any more */
return;
}
ssize_t bytes = _tl_send(&memo->socket, memo->msg.data.pdu_buf,
memo->msg.data.pdu_len, &memo->remote_ep, NULL);
if (bytes <= 0) {
DEBUG("gcoap: sock resend failed: %d\n", (int)bytes);
_expire_request(memo);
}
}
}
/* Change the retransmission of the memo such that no requests are sent any more.
*
* This is used in response to an empty ACK.
*
* The current implementation does not touch the timers, but merely sets the
* memo's state to GCOAP_MEMO_WAIT. This approach needs less complex code at
* the cost of the remaining `send_limit` timers firing and some memory not
* being freed until the actual response arrives.
*
* An alternative implementation would stop the timeouts, and either free the
* whole memo if it has no response handler, or calculate the remaining timeout
* from `send_limit` to set a final timeout then. In that case, it might also
* free the gcoap_resend_t data and move it back into hdr_buf (along with a
* change in the discriminator for that). (That's not an option with the
* current design because the discriminator is the send_limit field, which is
* still used to count down).
*
* @param[inout] memo The memo indicating the pending request
*
* @pre The @p memo is GCOAP_MEMO_RETRANSMIT or GCOAP_MEMO_WAIT, and its
* send_limit is not GCOAP_SEND_LIMIT_NON.
*/
static void _cease_retransmission(gcoap_request_memo_t *memo) {
memo->state = GCOAP_MEMO_WAIT;
/* there is also no response handler to wait for => expire memo */
if (memo->resp_handler == NULL) {
event_timeout_clear(&memo->resp_evt_tmout);
_expire_request(memo);
}
}
/*
* Main request handler: generates response PDU in the provided buffer.
*
* Caller must finish the PDU and send it.
*
* return length of response pdu, or < 0 if can't handle
*/
static size_t _handle_req(gcoap_socket_t *sock, coap_pkt_t *pdu, uint8_t *buf,
size_t len, sock_udp_ep_t *remote)
{
const coap_resource_t *resource = NULL;
gcoap_listener_t *listener = NULL;
sock_udp_ep_t *observer = NULL;
gcoap_observe_memo_t *memo = NULL;
gcoap_observe_memo_t *resource_memo = NULL;
switch (_find_resource(sock->type, pdu, &resource, &listener)) {
case GCOAP_RESOURCE_WRONG_METHOD:
return gcoap_response(pdu, buf, len, COAP_CODE_METHOD_NOT_ALLOWED);
case GCOAP_RESOURCE_NO_PATH:
return gcoap_response(pdu, buf, len, COAP_CODE_PATH_NOT_FOUND);
case GCOAP_RESOURCE_FOUND:
/* find observe registration for resource */
_find_obs_memo_resource(&resource_memo, resource);
break;
case GCOAP_RESOURCE_ERROR:
default:
return gcoap_response(pdu, buf, len, COAP_CODE_INTERNAL_SERVER_ERROR);
break;
}
if (coap_get_observe(pdu) == COAP_OBS_REGISTER) {
/* lookup remote+token */
int empty_slot = _find_obs_memo(&memo, remote, pdu);
/* validate re-registration request */
if (resource_memo != NULL) {
if (memo != NULL) {
if (memo != resource_memo) {
/* reject token already used for a different resource */
memo = NULL;
coap_clear_observe(pdu);
DEBUG("gcoap: can't change resource for token\n");
}
/* otherwise OK to re-register resource with the same token */
}
else if ((sock->type == resource_memo->socket.type) &&
sock_udp_ep_equal(remote, resource_memo->observer)) {
/* accept new token for resource */
memo = resource_memo;
}
}
/* initialize new registration request */
if ((memo == NULL) && coap_has_observe(pdu)) {
/* verify resource not already registered (for another endpoint) */
if ((empty_slot >= 0) && (resource_memo == NULL)) {
int obs_slot = _find_observer(&observer, remote);
/* cache new observer */
if (observer == NULL) {
if (obs_slot >= 0) {
observer = &_coap_state.observers[obs_slot];
memcpy(observer, remote, sizeof(sock_udp_ep_t));
} else {
DEBUG("gcoap: can't register observer\n");
}
}
if (observer != NULL) {
memo = &_coap_state.observe_memos[empty_slot];
memo->observer = observer;
}
}
if (memo == NULL) {
coap_clear_observe(pdu);
DEBUG("gcoap: can't register observe memo\n");
}
}
/* finish registration */
if (memo != NULL) {
/* resource may be assigned here if it is not already registered */
memo->resource = resource;
memo->token_len = coap_get_token_len(pdu);
memo->socket = *sock;
if (memo->token_len) {
memcpy(&memo->token[0], coap_get_token(pdu), memo->token_len);
}
DEBUG("gcoap: Registered observer for: %s\n", memo->resource->path);
}
} else if (coap_get_observe(pdu) == COAP_OBS_DEREGISTER) {
_find_obs_memo(&memo, remote, pdu);
/* clear memo, and clear observer if no other memos */
if (memo != NULL) {
DEBUG("gcoap: Deregistering observer for: %s\n", memo->resource->path);
memo->observer = NULL;
memo = NULL;
_find_obs_memo(&memo, remote, NULL);
if (memo == NULL) {
_find_observer(&observer, remote);
if (observer != NULL) {
observer->family = AF_UNSPEC;
}
}
}
coap_clear_observe(pdu);
} else if (coap_has_observe(pdu)) {
/* bogus request; don't respond */
DEBUG("gcoap: Observe value unexpected: %" PRIu32 "\n", coap_get_observe(pdu));
return -1;
}
ssize_t pdu_len;
coap_request_ctx_t ctx = {
.resource = resource,
.tl_type = (uint32_t)sock->type,
.remote = remote,
};
pdu_len = resource->handler(pdu, buf, len, &ctx);
if (pdu_len < 0) {
pdu_len = gcoap_response(pdu, buf, len,
COAP_CODE_INTERNAL_SERVER_ERROR);
}
return pdu_len;
}
static int _request_matcher_default(gcoap_listener_t *listener,
const coap_resource_t **resource,
coap_pkt_t *pdu)
{
uint8_t uri[CONFIG_NANOCOAP_URI_MAX];
int ret = GCOAP_RESOURCE_NO_PATH;
if (coap_get_uri_path(pdu, uri) <= 0) {
/* The Uri-Path options are longer than
* CONFIG_NANOCOAP_URI_MAX, and thus do not match anything
* that could be found by this handler. */
return GCOAP_RESOURCE_NO_PATH;
}
coap_method_flags_t method_flag = coap_method2flag(
coap_get_code_detail(pdu));
for (size_t i = 0; i < listener->resources_len; i++) {
*resource = &listener->resources[i];
int res = coap_match_path(*resource, uri);
/* URI mismatch */
if (res != 0) {
continue;
}
/* potential match, check for method */
if (! ((*resource)->methods & method_flag)) {
/* record wrong method error for next iteration, in case
* another resource with the same URI and correct method
* exists */
ret = GCOAP_RESOURCE_WRONG_METHOD;
continue;
}
else {
return GCOAP_RESOURCE_FOUND;
}
}
return ret;
}
/*
* Searches listener registrations for the resource matching the path in a PDU.
*
* param[in] tl_type -- transport the request for the resource came over.
* param[in] pdu -- the PDU to check the resource for
* param[out] resource_ptr -- found resource
* param[out] listener_ptr -- listener for found resource
* return `GCOAP_RESOURCE_FOUND` if the resource was found,
* `GCOAP_RESOURCE_WRONG_METHOD` if a resource was found but the method
* code didn't match and `GCOAP_RESOURCE_NO_PATH` if no matching
* resource was found.
*/
static int _find_resource(gcoap_socket_type_t tl_type,
coap_pkt_t *pdu,
const coap_resource_t **resource_ptr,
gcoap_listener_t **listener_ptr)
{
int ret = GCOAP_RESOURCE_NO_PATH;
/* Find path for CoAP msg among listener resources and execute callback. */
gcoap_listener_t *listener = _coap_state.listeners;
while (listener) {
const coap_resource_t *resource;
int res;
/* only makes sense to check if non-UDP transports are supported,
* so check if module is used first. */
if (IS_USED(MODULE_GCOAP_DTLS) &&
(listener->tl_type != GCOAP_SOCKET_TYPE_UNDEF) &&
!(listener->tl_type & tl_type)) {
listener = listener->next;
continue;
}
res = listener->request_matcher(listener, &resource, pdu);
/* check next resource on mismatch */
if (res == GCOAP_RESOURCE_NO_PATH) {
listener = listener->next;
continue;
}
/* found a resource, but methods do not match */
else if (res == GCOAP_RESOURCE_WRONG_METHOD) {
ret = GCOAP_RESOURCE_WRONG_METHOD;
listener = listener->next;
continue;
}
/* found a suitable resource */
else if (res == GCOAP_RESOURCE_FOUND) {
*resource_ptr = resource;
*listener_ptr = listener;
return GCOAP_RESOURCE_FOUND;
}
/* res is probably GCOAP_RESOURCE_ERROR or some other
* unhandled error */
else {
return GCOAP_RESOURCE_ERROR;
}
}
return ret;
}
static bool _memo_ep_is_multicast(const gcoap_request_memo_t *memo)
{
switch (memo->remote_ep.family) {
#ifdef SOCK_HAS_IPV6
case AF_INET6:
return ipv6_addr_is_multicast((const ipv6_addr_t *)&memo->remote_ep.addr.ipv6);
#endif
#ifdef SOCK_HAS_IPV4
case AF_INET:
return ipv4_addr_is_multicast((const ipv4_addr_t *)&memo->remote_ep.addr.ipv4);
#endif
default:
assert(0);
}
return false;
}
/*
* Finds the memo for an outstanding request within the _coap_state.open_reqs
* array. Matches on remote endpoint and token.
*
* memo_ptr[out] -- Registered request memo, or NULL if not found
* src_pdu[in] -- PDU for token to match
* remote[in] -- Remote endpoint to match
* by_mid[in] -- true if matches are to be done based on Message ID, otherwise they are done by
* token
*/
static void _find_req_memo(gcoap_request_memo_t **memo_ptr, coap_pkt_t *src_pdu,
const sock_udp_ep_t *remote, bool by_mid)
{
*memo_ptr = NULL;
/* no need to initialize struct; we only care about buffer contents below */
coap_pkt_t memo_pdu_data;
coap_pkt_t *memo_pdu = &memo_pdu_data;
unsigned cmplen = coap_get_token_len(src_pdu);
for (int i = 0; i < CONFIG_GCOAP_REQ_WAITING_MAX; i++) {
if (_coap_state.open_reqs[i].state == GCOAP_MEMO_UNUSED) {
continue;
}
gcoap_request_memo_t *memo = &_coap_state.open_reqs[i];
memo_pdu->hdr = gcoap_request_memo_get_hdr(memo);
if (by_mid) {
if ((src_pdu->hdr->id == memo_pdu->hdr->id)
&& sock_udp_ep_equal(&memo->remote_ep, remote)) {
*memo_ptr = memo;
break;
}
} else if (coap_get_token_len(memo_pdu) == cmplen) {
if ((memcmp(coap_get_token(src_pdu), coap_get_token(memo_pdu), cmplen) == 0)
&& (sock_udp_ep_equal(&memo->remote_ep, remote)
/* Multicast addresses are not considered in matching responses */
|| _memo_ep_is_multicast(memo)
)) {
*memo_ptr = memo;
break;
}
}
}
}
/* Calls handler callback on receipt of a timeout message. */
static void _expire_request(gcoap_request_memo_t *memo)
{
DEBUG("coap: received timeout message\n");
if ((memo->state == GCOAP_MEMO_RETRANSMIT) || (memo->state == GCOAP_MEMO_WAIT)) {
memo->state = GCOAP_MEMO_TIMEOUT;
/* Pass response to handler */
if (memo->resp_handler) {
coap_pkt_t req;
req.hdr = gcoap_request_memo_get_hdr(memo);
memo->resp_handler(memo, &req, NULL);
}
if (memo->send_limit != GCOAP_SEND_LIMIT_NON) {
*memo->msg.data.pdu_buf = 0; /* clear resend buffer */
}
memo->state = GCOAP_MEMO_UNUSED;
}
else {
/* Response already handled; timeout must have fired while response */
/* was in queue. */
}
}
/*
* Handler for /.well-known/core. Lists registered handlers, except for
* /.well-known/core itself.
*/
static ssize_t _well_known_core_handler(coap_pkt_t* pdu, uint8_t *buf, size_t len,
coap_request_ctx_t *ctx)
{
(void)ctx;
gcoap_resp_init(pdu, buf, len, COAP_CODE_CONTENT);
coap_opt_add_format(pdu, COAP_FORMAT_LINK);
ssize_t plen = coap_opt_finish(pdu, COAP_OPT_FINISH_PAYLOAD);
plen += gcoap_get_resource_list_tl(pdu->payload, (size_t)pdu->payload_len,
COAP_FORMAT_LINK,
(gcoap_socket_type_t)coap_request_ctx_get_tl_type(ctx));
return plen;
}
/*
* Find registered observer for a remote address and port.
*
* observer[out] -- Registered observer, or NULL if not found
* remote[in] -- Endpoint to match
*
* return Index of empty slot, suitable for registering new observer; or -1
* if no empty slots. Undefined if observer found.
*/
static int _find_observer(sock_udp_ep_t **observer, sock_udp_ep_t *remote)
{
int empty_slot = -1;
*observer = NULL;
for (unsigned i = 0; i < CONFIG_GCOAP_OBS_CLIENTS_MAX; i++) {
if (_coap_state.observers[i].family == AF_UNSPEC) {
empty_slot = i;
}
else if (sock_udp_ep_equal(&_coap_state.observers[i], remote)) {
*observer = &_coap_state.observers[i];
break;
}
}
return empty_slot;
}
/*
* Find registered observe memo for a remote address and token.
*
* memo[out] -- Registered observe memo, or NULL if not found
* remote[in] -- Endpoint for address to match
* pdu[in] -- PDU for token to match, or NULL to match only on remote address
*
* return Index of empty slot, suitable for registering new memo; or -1 if no
* empty slots. Undefined if memo found.
*/
static int _find_obs_memo(gcoap_observe_memo_t **memo, sock_udp_ep_t *remote,
coap_pkt_t *pdu)
{
int empty_slot = -1;
*memo = NULL;
sock_udp_ep_t *remote_observer = NULL;
_find_observer(&remote_observer, remote);
for (unsigned i = 0; i < CONFIG_GCOAP_OBS_REGISTRATIONS_MAX; i++) {
if (_coap_state.observe_memos[i].observer == NULL) {
empty_slot = i;
continue;
}
if (_coap_state.observe_memos[i].observer == remote_observer) {
if (pdu == NULL) {
*memo = &_coap_state.observe_memos[i];
break;
}
unsigned memo_token_len = _coap_state.observe_memos[i].token_len;
if (memo_token_len == coap_get_token_len(pdu)
&& memo_token_len
&& memcmp(&_coap_state.observe_memos[i].token[0],
coap_get_token(pdu),
memo_token_len) == 0) {
*memo = &_coap_state.observe_memos[i];
break;
}
}
}
return empty_slot;
}
/*
* Find registered observe memo for a resource.
*
* memo[out] -- Registered observe memo, or NULL if not found
* resource[in] -- Resource to match
*/
static void _find_obs_memo_resource(gcoap_observe_memo_t **memo,
const coap_resource_t *resource)
{
*memo = NULL;
for (int i = 0; i < CONFIG_GCOAP_OBS_REGISTRATIONS_MAX; i++) {
if (_coap_state.observe_memos[i].observer != NULL
&& _coap_state.observe_memos[i].resource == resource) {
*memo = &_coap_state.observe_memos[i];
break;
}
}
}
/*
* Transport layer functions
*/
static int _tl_init_coap_socket(gcoap_socket_t *sock, gcoap_socket_type_t type)
{
switch (type) {
#if !IS_USED(MODULE_GCOAP_DTLS)
case GCOAP_SOCKET_TYPE_UNDEF:
#endif
case GCOAP_SOCKET_TYPE_UDP:
sock->type = GCOAP_SOCKET_TYPE_UDP;
sock->socket.udp = &_sock_udp;
break;
#if IS_USED(MODULE_GCOAP_DTLS)
case GCOAP_SOCKET_TYPE_UNDEF:
case GCOAP_SOCKET_TYPE_DTLS:
sock->type = GCOAP_SOCKET_TYPE_DTLS;
sock->socket.dtls = &_sock_dtls;
break;
#else
default:
return -1;
#endif
}
return 0;
}
static ssize_t _tl_send(gcoap_socket_t *sock, const void *data, size_t len,
const sock_udp_ep_t *remote, sock_udp_aux_tx_t *aux)
{
ssize_t res = -1;
switch (sock->type) {
case GCOAP_SOCKET_TYPE_UDP:
res = sock_udp_send_aux(sock->socket.udp, data, len, remote, aux);
break;
#if IS_USED(MODULE_GCOAP_DTLS)
case GCOAP_SOCKET_TYPE_DTLS:
/* prepare session */
sock_dtls_session_set_udp_ep(&sock->ctx_dtls_session, remote);
dsm_state_t session_state = dsm_store(sock->socket.dtls,
&sock->ctx_dtls_session,
SESSION_STATE_HANDSHAKE,
true);
if (session_state == NO_SPACE) {
return -1;
}
/* send application data */
res = sock_dtls_send(sock->socket.dtls, &sock->ctx_dtls_session, data, len,
SOCK_NO_TIMEOUT);
switch (res) {
case -EHOSTUNREACH:
case -ENOTCONN:
case 0:
DEBUG("gcoap: DTLS sock not connected or remote unreachable. "
"Destroying session.\n");
dsm_remove(sock->socket.dtls, &sock->ctx_dtls_session);
sock_dtls_session_destroy(sock->socket.dtls, &sock->ctx_dtls_session);
break;
default:
/* Temporary error. Keeping the DTLS session */
break;
}
break;
#endif
default:
DEBUG("gcoap: undefined socket type\n");
break;
}
return res;
}
static ssize_t _tl_authenticate(gcoap_socket_t *sock, const sock_udp_ep_t *remote,
uint32_t timeout)
{
#if !IS_USED(MODULE_GCOAP_DTLS)
(void)sock;
(void)remote;
(void)timeout;
return 0;
#else
int res;
if (sock->type != GCOAP_SOCKET_TYPE_DTLS) {
return 0;
}
/* prepare session */
sock_dtls_session_set_udp_ep(&sock->ctx_dtls_session, remote);
dsm_state_t session_state = dsm_store(sock->socket.dtls, &sock->ctx_dtls_session,
SESSION_STATE_HANDSHAKE, true);
if (session_state == SESSION_STATE_ESTABLISHED) {
return 0;
}
if (session_state == NO_SPACE) {
DEBUG("gcoap: no space in dsm\n");
return -ENOTCONN;
}
/* start handshake */
_auth_waiting_thread = thread_getpid();
res = sock_dtls_session_init(sock->socket.dtls, remote, &sock->ctx_dtls_session);
if (res == 0) {
/* session already exists */
_auth_waiting_thread = -1;
return res;
}
msg_t msg;
bool is_timed_out = false;
do {
uint32_t start = ztimer_now(ZTIMER_MSEC);
res = ztimer_msg_receive_timeout(ZTIMER_MSEC, &msg, timeout);
/* ensure whole timeout time for the case we receive other messages than
* DTLS_EVENT_CONNECTED */
if (timeout != SOCK_NO_TIMEOUT) {
uint32_t diff = (ztimer_now(ZTIMER_MSEC) - start);
timeout = (diff > timeout) ? 0: timeout - diff;
is_timed_out = (res < 0) || (timeout == 0);
}
}
while (!is_timed_out && (msg.type != DTLS_EVENT_CONNECTED));
if (is_timed_out && (msg.type != DTLS_EVENT_CONNECTED)) {
DEBUG("gcoap: authentication timed out\n");
dsm_remove(sock->socket.dtls, &sock->ctx_dtls_session);
sock_dtls_session_destroy(sock->socket.dtls, &sock->ctx_dtls_session);
return -ENOTCONN;
}
return 0;
#endif
}
static nanocoap_cache_entry_t *_cache_lookup_memo(gcoap_request_memo_t *memo)
{
#if IS_USED(MODULE_NANOCOAP_CACHE)
/* cache_key in memo is pre-processor guarded so we need to as well */
return nanocoap_cache_key_lookup(memo->cache_key);
#else
(void)memo;
return NULL;
#endif
}
static void _cache_process(gcoap_request_memo_t *memo,
coap_pkt_t *pdu)
{
if (!IS_USED(MODULE_NANOCOAP_CACHE)) {
return;
}
coap_pkt_t req;
req.hdr = gcoap_request_memo_get_hdr(memo);
size_t pdu_len = pdu->payload_len +
(pdu->payload - (uint8_t *)pdu->hdr);
#if IS_USED(MODULE_NANOCOAP_CACHE)
nanocoap_cache_entry_t *ce;
/* cache_key in memo is pre-processor guarded so we need to as well */
if ((ce = nanocoap_cache_process(memo->cache_key, coap_get_code(&req), pdu, pdu_len))) {
ce->truncated = (memo->state == GCOAP_MEMO_RESP_TRUNC);
}
#else
(void)req;
(void)pdu_len;
#endif
}
static ssize_t _cache_build_response(nanocoap_cache_entry_t *ce, coap_pkt_t *pdu,
uint8_t *buf, size_t len)
{
if (!IS_USED(MODULE_NANOCOAP_CACHE)) {
return -ENOTSUP;
}
if (len < ce->response_len) {
return -ENOBUFS;
}
/* Use the same code from the cached content. Use other header
* fields from the incoming request */
gcoap_resp_init(pdu, buf, len, ce->response_pkt.hdr->code);
/* copy all options and possible payload from the cached response
* to the new response */
unsigned header_len_req = coap_get_total_hdr_len(pdu);
unsigned header_len_cached = coap_get_total_hdr_len(&ce->response_pkt);
unsigned opt_payload_len = ce->response_len - header_len_cached;
/* copy all options and possible payload from the cached response
* to the new response */
memcpy((buf + header_len_req),
(ce->response_buf + header_len_cached),
opt_payload_len);
/* parse into pdu including all options and payload pointers etc */
coap_parse(pdu, buf, header_len_req + opt_payload_len);
return ce->response_len;
}
static void _copy_hdr_from_req_memo(coap_pkt_t *pdu, gcoap_request_memo_t *memo)
{
coap_pkt_t req_pdu;
req_pdu.hdr = gcoap_request_memo_get_hdr(memo);
memcpy(pdu->hdr, req_pdu.hdr, coap_get_total_hdr_len(&req_pdu));
}
static void _receive_from_cache_cb(void *ctx)
{
if (!IS_USED(MODULE_NANOCOAP_CACHE)) {
return;
}
gcoap_request_memo_t *memo = ctx;
nanocoap_cache_entry_t *ce = NULL;
if ((ce = _cache_lookup_memo(memo))) {
if (memo->resp_handler) {
/* copy header from request so gcoap_resp_init in _cache_build_response works correctly
*/
coap_pkt_t pdu = { .hdr = (coap_hdr_t *)_listen_buf };
_copy_hdr_from_req_memo(&pdu, memo);
if (_cache_build_response(ce, &pdu, _listen_buf, sizeof(_listen_buf)) >= 0) {
memo->state = (ce->truncated) ? GCOAP_MEMO_RESP_TRUNC : GCOAP_MEMO_RESP;
memo->resp_handler(memo, &pdu, &memo->remote_ep);
if (memo->send_limit >= 0) { /* if confirmable */
*memo->msg.data.pdu_buf = 0; /* clear resend PDU buffer */
}
memo->state = GCOAP_MEMO_UNUSED;
}
}
}
else {
/* oops we somehow lost the cache entry */
DEBUG("gcoap: cache entry was lost\n");
if (memo->resp_handler) {
memo->state = GCOAP_MEMO_ERR;
memo->resp_handler(memo, NULL, &memo->remote_ep);
}
}
}
static void _update_memo_cache_key(gcoap_request_memo_t *memo, uint8_t *cache_key)
{
#if IS_USED(MODULE_NANOCOAP_CACHE)
if (memo) {
/* memo->cache_key is guarded by MODULE_NANOCOAP_CACHE, so preprocessor
* magic is needed */
memcpy(memo->cache_key, cache_key, CONFIG_NANOCOAP_CACHE_KEY_LENGTH);
}
#else
(void)memo;
(void)cache_key;
#endif
}
static bool _cache_lookup(gcoap_request_memo_t *memo,
coap_pkt_t *pdu,
nanocoap_cache_entry_t **ce)
{
if (IS_USED(MODULE_NANOCOAP_CACHE)) {
uint8_t cache_key[SHA256_DIGEST_LENGTH];
ztimer_now_t now = ztimer_now(ZTIMER_SEC);
nanocoap_cache_key_generate(pdu, cache_key);
*ce = nanocoap_cache_key_lookup(cache_key);
_update_memo_cache_key(memo, cache_key);
/* cache hit, methods are equal, and cache entry is not stale */
if (*ce &&
((*ce)->request_method == coap_get_code(pdu)) &&
!nanocoap_cache_entry_is_stale(*ce, now)) {
return true;
}
}
return false;
}
static ssize_t _cache_check(const uint8_t *buf, size_t len,
gcoap_request_memo_t *memo,
bool *cache_hit)
{
if (!IS_USED(MODULE_NANOCOAP_CACHE)) {
return len;
}
coap_pkt_t req;
nanocoap_cache_entry_t *ce = NULL;
/* XXX cast to const might cause problems here :-/ */
ssize_t res = coap_parse(&req, (uint8_t *)buf, len);
if (res < 0) {
DEBUG("gcoap: parse failure for cache lookup: %d\n", (int)res);
return -EINVAL;
}
if (coap_get_code_class(&req) != COAP_CLASS_REQ) {
/* Not a request so ignore, as gcoap_req_send might have been used with
* its undocumented function to send a CON response from submodule */
return len;
}
*cache_hit = _cache_lookup(memo, &req, &ce);
if (!(*cache_hit) && (ce != NULL)) {
/* Cache entry was found, but it is stale. Try to validate */
uint8_t *resp_etag;
/* Searching for more ETags might become necessary in the future */
ssize_t resp_etag_len = coap_opt_get_opaque(&ce->response_pkt, COAP_OPT_ETAG, &resp_etag);
/* ETag found, but don't act on illegal ETag size */
if ((resp_etag_len > 0) && ((size_t)resp_etag_len <= COAP_ETAG_LENGTH_MAX)) {
uint8_t *tmp_etag;
ssize_t tmp_etag_len = coap_opt_get_opaque(&req, COAP_OPT_ETAG, &tmp_etag);
if (tmp_etag_len >= resp_etag_len) {
memcpy(tmp_etag, resp_etag, resp_etag_len);
/* shorten ETag option if necessary */
if ((size_t)resp_etag_len < COAP_ETAG_LENGTH_MAX) {
/* now we need the start of the option (not its value) so dig once more */
uint8_t *start = coap_find_option(&req, COAP_OPT_ETAG);
/* option length must always be <= COAP_ETAG_LENGTH_MAX = 8 < 12, so the length
* is encoded in the first byte, see also RFC 7252, section 3.1 */
*start &= 0xf0;
/* first if around here should make sure we are <= 8 < 0xf, so we don't need to
* bitmask resp_etag_len */
*start |= (uint8_t)resp_etag_len;
/* remove padding */
size_t rem_len = (len - (tmp_etag + COAP_ETAG_LENGTH_MAX - buf));
memmove(tmp_etag + resp_etag_len, tmp_etag + COAP_ETAG_LENGTH_MAX, rem_len);
len -= (COAP_ETAG_LENGTH_MAX - resp_etag_len);
}
}
}
else {
len = coap_opt_remove(&req, COAP_OPT_ETAG);
}
}
else {
len = coap_opt_remove(&req, COAP_OPT_ETAG);
}
return len;
}
/*
* gcoap interface functions
*/
kernel_pid_t gcoap_init(void)
{
if (_pid != KERNEL_PID_UNDEF) {
return -EEXIST;
}
_pid = thread_create(_msg_stack, sizeof(_msg_stack), THREAD_PRIORITY_MAIN - 1,
THREAD_CREATE_STACKTEST, _event_loop, NULL, "coap");
mutex_init(&_coap_state.lock);
/* Blank lists so we know if an entry is available. */
memset(&_coap_state.open_reqs[0], 0, sizeof(_coap_state.open_reqs));
memset(&_coap_state.observers[0], 0, sizeof(_coap_state.observers));
memset(&_coap_state.observe_memos[0], 0, sizeof(_coap_state.observe_memos));
memset(&_coap_state.resend_bufs[0], 0, sizeof(_coap_state.resend_bufs));
/* randomize initial value */
atomic_init(&_coap_state.next_message_id, (unsigned)random_uint32());
if (IS_USED(MODULE_NANOCOAP_CACHE)) {
nanocoap_cache_init();
}
/* initialize the forward proxy operation, if compiled */
if (IS_ACTIVE(MODULE_GCOAP_FORWARD_PROXY)) {
gcoap_forward_proxy_init();
}
return _pid;
}
uint16_t gcoap_next_msg_id(void)
{
return (uint16_t)atomic_fetch_add(&_coap_state.next_message_id, 1);
}
void gcoap_register_listener(gcoap_listener_t *listener)
{
/* That item will be overridden, ensure that the user expecting different
* behavior will notice this. */
assert(listener->next == NULL);
listener->next = _coap_state.listeners;
_coap_state.listeners = listener;
if (!listener->link_encoder) {
listener->link_encoder = gcoap_encode_link;
}
if (!listener->request_matcher) {
listener->request_matcher = _request_matcher_default;
}
}
int gcoap_req_init_path_buffer(coap_pkt_t *pdu, uint8_t *buf, size_t len,
unsigned code, const char *path, size_t path_len)
{
assert((path == NULL) || (path[0] == '/'));
pdu->hdr = (coap_hdr_t *)buf;
/* generate token */
uint16_t msgid = gcoap_next_msg_id();
ssize_t res;
if (code) {
#if CONFIG_GCOAP_TOKENLEN
uint8_t token[CONFIG_GCOAP_TOKENLEN];
for (size_t i = 0; i < CONFIG_GCOAP_TOKENLEN; i += 4) {
uint32_t rand = random_uint32();
memcpy(&token[i],
&rand,
(CONFIG_GCOAP_TOKENLEN - i >= 4) ? 4 : CONFIG_GCOAP_TOKENLEN - i);
}
res = coap_build_hdr(pdu->hdr, COAP_TYPE_NON, &token[0],
CONFIG_GCOAP_TOKENLEN, code, msgid);
#else
res = coap_build_hdr(pdu->hdr, COAP_TYPE_NON, NULL,
CONFIG_GCOAP_TOKENLEN, code, msgid);
#endif
}
else {
/* ping request */
res = coap_build_hdr(pdu->hdr, COAP_TYPE_CON, NULL, 0, code, msgid);
}
coap_pkt_init(pdu, buf, len, res);
if (IS_USED(MODULE_NANOCOAP_CACHE)) {
static const uint8_t tmp[COAP_ETAG_LENGTH_MAX] = { 0 };
/* add slack to maybe add an ETag on stale cache hit later */
res = coap_opt_add_opaque(pdu, COAP_OPT_ETAG, tmp, sizeof(tmp));
}
if ((res > 0) && (path != NULL) && (path_len > 0)) {
res = coap_opt_add_uri_path_buffer(pdu, path, path_len);
}
return (res > 0) ? 0 : res;
}
ssize_t gcoap_req_send_tl(const uint8_t *buf, size_t len,
const sock_udp_ep_t *remote,
gcoap_resp_handler_t resp_handler, void *context,
gcoap_socket_type_t tl_type)
{
gcoap_socket_t socket = { 0 };
gcoap_request_memo_t *memo = NULL;
unsigned msg_type = (*buf & 0x30) >> 4;
uint32_t timeout = 0;
ssize_t res = 0;
bool cache_hit = false;
assert(remote != NULL);
res = _tl_init_coap_socket(&socket, tl_type);
if (res < 0) {
return -EINVAL;
}
/* Only allocate memory if necessary (i.e. if user is interested in the
* response or request is confirmable) */
if ((resp_handler != NULL) || (msg_type == COAP_TYPE_CON)) {
mutex_lock(&_coap_state.lock);
/* Find empty slot in list of open requests. */
for (int i = 0; i < CONFIG_GCOAP_REQ_WAITING_MAX; i++) {
if (_coap_state.open_reqs[i].state == GCOAP_MEMO_UNUSED) {
memo = &_coap_state.open_reqs[i];
memo->state = GCOAP_MEMO_WAIT;
break;
}
}
if (!memo) {
mutex_unlock(&_coap_state.lock);
DEBUG("gcoap: dropping request; no space for response tracking\n");
return 0;
}
memo->resp_handler = resp_handler;
memo->context = context;
memcpy(&memo->remote_ep, remote, sizeof(sock_udp_ep_t));
memo->socket = socket;
if (IS_USED(MODULE_NANOCOAP_CACHE)) {
ssize_t res = _cache_check(buf, len, memo, &cache_hit);
if (res < 0) {
return res;
}
len = res;
}
switch (msg_type) {
case COAP_TYPE_CON:
/* copy buf to resend_bufs record */
memo->msg.data.pdu_buf = NULL;
for (int i = 0; i < CONFIG_GCOAP_RESEND_BUFS_MAX; i++) {
if (!_coap_state.resend_bufs[i][0]) {
memo->msg.data.pdu_buf = &_coap_state.resend_bufs[i][0];
memcpy(memo->msg.data.pdu_buf, buf,
CONFIG_GCOAP_PDU_BUF_SIZE);
memo->msg.data.pdu_len = len;
break;
}
}
if (memo->msg.data.pdu_buf) {
memo->send_limit = CONFIG_COAP_MAX_RETRANSMIT;
timeout = (uint32_t)CONFIG_COAP_ACK_TIMEOUT_MS;
#if CONFIG_COAP_RANDOM_FACTOR_1000 > 1000
timeout = random_uint32_range(timeout, TIMEOUT_RANGE_END);
#endif
memo->state = GCOAP_MEMO_RETRANSMIT;
}
else {
memo->state = GCOAP_MEMO_UNUSED;
DEBUG("gcoap: no space for PDU in resend bufs\n");
}
break;
case COAP_TYPE_NON:
memo->send_limit = GCOAP_SEND_LIMIT_NON;
memcpy(&memo->msg.hdr_buf[0], buf, GCOAP_HEADER_MAXLEN);
timeout = CONFIG_GCOAP_NON_TIMEOUT_MSEC;
break;
default:
memo->state = GCOAP_MEMO_UNUSED;
DEBUG("gcoap: illegal msg type %u\n", msg_type);
break;
}
mutex_unlock(&_coap_state.lock);
if (memo->state == GCOAP_MEMO_UNUSED) {
return 0;
}
if (cache_hit) {
/* post to receive cache entry */
event_callback_init(&_receive_from_cache,
_receive_from_cache_cb,
memo);
event_post(&_queue, &_receive_from_cache.super);
return len;
}
}
/* check cache without memo */
else if (IS_USED(MODULE_NANOCOAP_CACHE)) {
ssize_t res = _cache_check(buf, len, NULL, &cache_hit);
if (res < 0) {
return res;
}
if (cache_hit > 0) {
return res;
}
}
_tl_init_coap_socket(&socket, tl_type);
if (IS_USED(MODULE_GCOAP_DTLS) && socket.type == GCOAP_SOCKET_TYPE_DTLS) {
res = _tl_authenticate(&socket, remote, CONFIG_GCOAP_DTLS_HANDSHAKE_TIMEOUT_MSEC);
}
/* set response timeout; may be zero for non-confirmable */
if (memo != NULL && res == 0) {
if (timeout > 0) {
event_callback_init(&memo->resp_tmout_cb, _on_resp_timeout, memo);
event_timeout_ztimer_init(&memo->resp_evt_tmout, ZTIMER_MSEC, &_queue,
&memo->resp_tmout_cb.super);
event_timeout_set(&memo->resp_evt_tmout, timeout);
}
else {
memset(&memo->resp_evt_tmout, 0, sizeof(event_timeout_t));
}
}
if (res == 0) {
res = _tl_send(&socket, buf, len, remote, NULL);
}
if (res <= 0) {
if (memo != NULL) {
if (msg_type == COAP_TYPE_CON) {
*memo->msg.data.pdu_buf = 0; /* clear resend buffer */
}
if (timeout > 0) {
event_timeout_clear(&memo->resp_evt_tmout);
}
memo->state = GCOAP_MEMO_UNUSED;
}
DEBUG("gcoap: sock send failed: %d\n", (int)res);
}
return ((res > 0 || res == -ENOTCONN) ? res : 0);
}
int gcoap_resp_init(coap_pkt_t *pdu, uint8_t *buf, size_t len, unsigned code)
{
if (coap_get_type(pdu) == COAP_TYPE_CON) {
coap_hdr_set_type(pdu->hdr, COAP_TYPE_ACK);
}
coap_hdr_set_code(pdu->hdr, code);
unsigned header_len = coap_get_total_hdr_len(pdu);
pdu->options_len = 0;
pdu->payload = buf + header_len;
pdu->payload_len = len - header_len;
if (coap_get_observe(pdu) == COAP_OBS_REGISTER) {
/* generate initial notification value */
uint32_t now = ztimer_now(ZTIMER_USEC);
pdu->observe_value = (now >> GCOAP_OBS_TICK_EXPONENT) & 0xFFFFFF;
coap_opt_add_uint(pdu, COAP_OPT_OBSERVE, pdu->observe_value);
}
return 0;
}
int gcoap_obs_init(coap_pkt_t *pdu, uint8_t *buf, size_t len,
const coap_resource_t *resource)
{
gcoap_observe_memo_t *memo = NULL;
_find_obs_memo_resource(&memo, resource);
if (memo == NULL) {
/* Unique return value to specify there is not an observer */
return GCOAP_OBS_INIT_UNUSED;
}
pdu->hdr = (coap_hdr_t *)buf;
uint16_t msgid = gcoap_next_msg_id();
ssize_t hdrlen = coap_build_hdr(pdu->hdr, COAP_TYPE_NON, &memo->token[0],
memo->token_len, COAP_CODE_CONTENT, msgid);
if (hdrlen > 0) {
coap_pkt_init(pdu, buf, len, hdrlen);
uint32_t now = ztimer_now(ZTIMER_USEC);
pdu->observe_value = (now >> GCOAP_OBS_TICK_EXPONENT) & 0xFFFFFF;
coap_opt_add_uint(pdu, COAP_OPT_OBSERVE, pdu->observe_value);
return GCOAP_OBS_INIT_OK;
}
else {
/* reason for negative hdrlen is not defined, so we also are vague */
return GCOAP_OBS_INIT_ERR;
}
}
size_t gcoap_obs_send(const uint8_t *buf, size_t len,
const coap_resource_t *resource)
{
gcoap_observe_memo_t *memo = NULL;
_find_obs_memo_resource(&memo, resource);
if (memo) {
ssize_t bytes = _tl_send(&memo->socket, buf, len, memo->observer, NULL);
return (size_t)((bytes > 0) ? bytes : 0);
}
else {
return 0;
}
}
uint8_t gcoap_op_state(void)
{
uint8_t count = 0;
for (int i = 0; i < CONFIG_GCOAP_REQ_WAITING_MAX; i++) {
if (_coap_state.open_reqs[i].state != GCOAP_MEMO_UNUSED) {
count++;
}
}
return count;
}
int gcoap_get_resource_list_tl(void *buf, size_t maxlen, uint8_t cf,
gcoap_socket_type_t tl_type)
{
assert(cf == COAP_FORMAT_LINK);
gcoap_listener_t *listener = _coap_state.listeners;
char *out = (char *)buf;
size_t pos = 0;
coap_link_encoder_ctx_t ctx;
ctx.content_format = cf;
/* indicate initial link for the list */
ctx.flags = COAP_LINK_FLAG_INIT_RESLIST;
/* write payload */
for (; listener != NULL; listener = listener->next) {
if (!listener->link_encoder) {
continue;
}
/* only makes sense to check if non-UDP transports are supported,
* so check if module is used first. */
if (IS_USED(MODULE_GCOAP_DTLS) &&
(tl_type != GCOAP_SOCKET_TYPE_UNDEF) &&
(listener->tl_type != GCOAP_SOCKET_TYPE_UNDEF) &&
((listener->tl_type & GCOAP_SOCKET_TYPE_UDP) != (tl_type & GCOAP_SOCKET_TYPE_UDP)) &&
((listener->tl_type & GCOAP_SOCKET_TYPE_DTLS) != (tl_type & GCOAP_SOCKET_TYPE_DTLS))) {
continue;
}
ctx.link_pos = 0;
for (; ctx.link_pos < listener->resources_len; ctx.link_pos++) {
ssize_t res;
if (out) {
res = listener->link_encoder(&listener->resources[ctx.link_pos],
&out[pos], maxlen - pos, &ctx);
}
else {
res = listener->link_encoder(&listener->resources[ctx.link_pos],
NULL, 0, &ctx);
}
if (res > 0) {
pos += res;
ctx.flags &= ~COAP_LINK_FLAG_INIT_RESLIST;
}
else {
break;
}
}
}
return (int)pos;
}
ssize_t gcoap_encode_link(const coap_resource_t *resource, char *buf,
size_t maxlen, coap_link_encoder_ctx_t *context)
{
size_t path_len = strlen(resource->path);
/* count target separators and any link separator */
size_t exp_size = path_len + 2
+ ((context->flags & COAP_LINK_FLAG_INIT_RESLIST) ? 0 : 1);
if (buf) {
unsigned pos = 0;
if (exp_size > maxlen) {
return -1;
}
if (!(context->flags & COAP_LINK_FLAG_INIT_RESLIST)) {
buf[pos++] = ',';
}
buf[pos++] = '<';
memcpy(&buf[pos], resource->path, path_len);
buf[pos+path_len] = '>';
}
return exp_size;
}
#if IS_USED(MODULE_GCOAP_DTLS)
sock_dtls_t *gcoap_get_sock_dtls(void)
{
return &_sock_dtls;
}
#endif
/* */
void gcoap_forward_proxy_find_req_memo(gcoap_request_memo_t **memo_ptr,
coap_pkt_t *src_pdu,
const sock_udp_ep_t *remote)
{
_find_req_memo(memo_ptr, src_pdu, remote, false);
}
void gcoap_forward_proxy_post_event(void *arg)
{
event_post(&_queue, arg);
}
/** @} */
View Git Blame Copy Permalink