1 /* coap_cache.c -- Caching of CoAP requests
3 * Copyright (C) 2020-2023 Olaf Bergmann <bergmann@tzi.org>
5  * SPDX-License-Identifier: BSD-2-Clause
7 * This file is part of the CoAP library libcoap. Please see
12  * @file coap_cache.c
13  * @brief CoAP Cache handling
20  * be used as CacheKey. Options that can be cache keys are not Unsafe
27   /* https://rfc-editor.org/rfc/rfc7252#section-5.4.6 Nocachekey definition */  in is_cache_key()
31    * https://rfc-editor.org/rfc/rfc7641#section-2 Observe is not a  in is_cache_key()
32    * part of the cache-key.  in is_cache_key()
37   /* Check for option user has defined as not part of cache-key */  in is_cache_key()
51   if (ctx->cache_ignore_options) {  in coap_cache_ignore_options()
52     coap_free_type(COAP_STRING, ctx->cache_ignore_options);  in coap_cache_ignore_options()
56     ctx->cache_ignore_options = coap_malloc_type(COAP_STRING, count * sizeof(options[0]));  in coap_cache_ignore_options()
57     if (ctx->cache_ignore_options) {  in coap_cache_ignore_options()
58       memcpy(ctx->cache_ignore_options, options, count * sizeof(options[0]));  in coap_cache_ignore_options()
59       ctx->cache_ignore_count = count;  in coap_cache_ignore_options()
65     ctx->cache_ignore_options = NULL;  in coap_cache_ignore_options()
66     ctx->cache_ignore_count = count;  in coap_cache_ignore_options()
111   /* The body of a FETCH payload is part of the cache key,  in coap_cache_derive_key_w_ignore()
112    * see https://rfc-editor.org/rfc/rfc8132#section-2 */  in coap_cache_derive_key_w_ignore()
113   if (pdu->code == COAP_REQUEST_CODE_FETCH) {  in coap_cache_derive_key_w_ignore()
129     memcpy(cache_key->key, digest.key, sizeof(cache_key->key));  in coap_cache_derive_key_w_ignore()
142                                         session->context->cache_ignore_options,  in coap_cache_derive_key()
143                                         session->context->cache_ignore_count);  in coap_cache_derive_key()
156   coap_cache_entry_t *entry = coap_malloc_type(COAP_CACHE_ENTRY,  in coap_new_cache_entry()  local
158   if (!entry) {  in coap_new_cache_entry()
162   memset(entry, 0, sizeof(coap_cache_entry_t));  in coap_new_cache_entry()
163   entry->session = session;  in coap_new_cache_entry()
165     entry->pdu = coap_pdu_init(pdu->type, pdu->code, pdu->mid, pdu->alloc_size);  in coap_new_cache_entry()
166     if (entry->pdu) {  in coap_new_cache_entry()
167       if (!coap_pdu_resize(entry->pdu, pdu->alloc_size)) {  in coap_new_cache_entry()
168         coap_delete_pdu(entry->pdu);  in coap_new_cache_entry()
169         coap_free_type(COAP_CACHE_ENTRY, entry);  in coap_new_cache_entry()
173       memcpy(entry->pdu, pdu, offsetof(coap_pdu_t, token));  in coap_new_cache_entry()
174       memcpy(entry->pdu->token, pdu->token, pdu->used_size);  in coap_new_cache_entry()
176       entry->pdu->data = entry->pdu->token + (pdu->data - pdu->token);  in coap_new_cache_entry()
179   entry->cache_key = coap_cache_derive_key(session, pdu, session_based);  in coap_new_cache_entry()
180   if (!entry->cache_key) {  in coap_new_cache_entry()
181     coap_free_type(COAP_CACHE_ENTRY, entry);  in coap_new_cache_entry()
184   entry->idle_timeout = idle_timeout;  in coap_new_cache_entry()
186     coap_ticks(&entry->expire_ticks);  in coap_new_cache_entry()
187     entry->expire_ticks += idle_timeout * COAP_TICKS_PER_SECOND;  in coap_new_cache_entry()
190   HASH_ADD(hh, session->context->cache, cache_key[0], sizeof(coap_cache_key_t), entry);  in coap_new_cache_entry()
191   return entry;  in coap_new_cache_entry()
200     HASH_FIND(hh, ctx->cache, cache_key, sizeof(coap_cache_key_t), cache_entry);  in coap_cache_get_by_key()
202   if (cache_entry && cache_entry->idle_timeout > 0) {  in coap_cache_get_by_key()
203     coap_ticks(&cache_entry->expire_ticks);  in coap_cache_get_by_key()
204     cache_entry->expire_ticks += cache_entry->idle_timeout * COAP_TICKS_PER_SECOND;  in coap_cache_get_by_key()
219   cache_entry = coap_cache_get_by_key(session->context, cache_key);  in coap_cache_get_by_pdu()
221   if (cache_entry && cache_entry->idle_timeout > 0) {  in coap_cache_get_by_pdu()
222     coap_ticks(&cache_entry->expire_ticks);  in coap_cache_get_by_pdu()
223     cache_entry->expire_ticks += cache_entry->idle_timeout * COAP_TICKS_PER_SECOND;  in coap_cache_get_by_pdu()
234     HASH_DELETE(hh, ctx->cache, cache_entry);  in coap_delete_cache_entry()
236   if (cache_entry->pdu) {  in coap_delete_cache_entry()
237     coap_delete_pdu(cache_entry->pdu);  in coap_delete_cache_entry()
239   coap_delete_cache_key(cache_entry->cache_key);  in coap_delete_cache_entry()
240   if (cache_entry->callback && cache_entry->app_data) {  in coap_delete_cache_entry()
241     cache_entry->callback(cache_entry->app_data);  in coap_delete_cache_entry()
248   return cache_entry->pdu;  in coap_cache_get_pdu()
255   cache_entry->app_data = data;  in coap_cache_set_app_data()
256   cache_entry->callback = callback;  in coap_cache_set_app_data()
261   return cache_entry->app_data;  in coap_cache_get_app_data()
270   HASH_ITER(hh, ctx->cache, cp, ctmp) {  in coap_expire_cache_entries()
271     if (cp->idle_timeout > 0) {  in coap_expire_cache_entries()
272       if (cp->expire_ticks <= now) {  in coap_expire_cache_entries()