/* * server-coap.c -- LwIP example * * Copyright (C) 2013-2016 Christian Amsüss * Copyright (C) 2018-2023 Jon Shallow * * SPDX-License-Identifier: BSD-2-Clause * * This file is part of the CoAP library libcoap. Please see README for terms * of use. */ #include "coap_config.h" #include #include "server-coap.h" coap_context_t *main_coap_context; static coap_time_t clock_offset; /* changeable clock base (see handle_put_time()) */ static coap_time_t my_clock_base = 0; static coap_resource_t *time_resource = NULL; /* just for testing */ #ifndef min # define min(a,b) ((a) < (b) ? (a) : (b)) #endif void hnd_get_time(coap_resource_t *resource, coap_session_t *session, const coap_pdu_t *request, const coap_string_t *query, coap_pdu_t *response) { unsigned char buf[40]; size_t len; coap_tick_t now; coap_tick_t t; (void)resource; (void)session; (void)request; /* FIXME: return time, e.g. in human-readable by default and ticks * when query ?ticks is given. */ /* if my_clock_base was deleted, we pretend to have no such resource */ response->code = my_clock_base ? COAP_RESPONSE_CODE(205) : COAP_RESPONSE_CODE(404); if (my_clock_base) coap_add_option(response, COAP_OPTION_CONTENT_FORMAT, coap_encode_var_safe(buf, sizeof(buf), COAP_MEDIATYPE_TEXT_PLAIN), buf); coap_add_option(response, COAP_OPTION_MAXAGE, coap_encode_var_safe(buf, sizeof(buf), 0x01), buf); if (my_clock_base) { /* calculate current time */ coap_ticks(&t); now = my_clock_base + (t / COAP_TICKS_PER_SECOND); if (query != NULL && coap_string_equal(query, coap_make_str_const("ticks"))) { /* output ticks */ len = snprintf((char *)buf, sizeof(buf), "%u", (unsigned int)now); coap_add_data(response, len, buf); } } } void init_coap_resources(coap_context_t *ctx) { coap_resource_t *r; #if 0 r = coap_resource_init(NULL, 0, 0); coap_register_handler(r, COAP_REQUEST_GET, hnd_get_index); coap_add_attr(r, coap_make_str_const("ct"), coap_make_str_const("0"), 0); coap_add_attr(r, coap_make_str_const("title"), coap_make_str_const("\"General Info\""), 0); coap_add_resource(ctx, r); #endif /* store clock base to use in /time */ my_clock_base = clock_offset; r = coap_resource_init(coap_make_str_const("time"), 0); if (!r) goto error; coap_resource_set_get_observable(r, 1); time_resource = r; coap_register_handler(r, COAP_REQUEST_GET, hnd_get_time); #if 0 coap_register_handler(r, COAP_REQUEST_PUT, hnd_put_time); coap_register_handler(r, COAP_REQUEST_DELETE, hnd_delete_time); #endif coap_add_attr(r, coap_make_str_const("ct"), coap_make_str_const("0"), 0); /* coap_add_attr(r, coap_make_str_const("title"), coap_make_str_const("\"Internal Clock\""), 0); */ coap_add_attr(r, coap_make_str_const("rt"), coap_make_str_const("\"ticks\""), 0); coap_add_attr(r, coap_make_str_const("if"), coap_make_str_const("\"clock\""), 0); coap_add_resource(ctx, r); #if 0 if (coap_async_is_supported()) { r = coap_resource_init(coap_make_str_const("async"), 0); coap_register_handler(r, COAP_REQUEST_GET, hnd_get_async); coap_add_attr(r, coap_make_str_const("ct"), coap_make_str_const("0"), 0); coap_add_resource(ctx, r); } #endif return; error: coap_log_crit("cannot create resource\n"); } void server_coap_init(coap_lwip_input_wait_handler_t input_wait, void *input_arg, int argc, char **argv) { int opt; coap_log_t log_level = COAP_LOG_WARN; coap_log_t dtls_log_level = COAP_LOG_ERR; const char *use_psk = "secretPSK"; uint32_t scheme_hint_bits = 0; coap_addr_info_t *info = NULL; coap_addr_info_t *info_list = NULL; int have_ep = 0; coap_str_const_t node; /* Initialize libcoap library */ coap_startup(); while ((opt = getopt(argc, argv, ":k:v:V:")) != -1) { switch (opt) { case 'k': use_psk = optarg; break; case 'v': log_level = atoi(optarg); break; case 'V': dtls_log_level = atoi(optarg); break; default: printf("%s [-k PSK] [-v level] [ -V level]\n", argv[0]); exit(1); } } coap_startup(); coap_set_log_level(log_level); coap_dtls_set_log_level(dtls_log_level); main_coap_context = coap_new_context(NULL); LWIP_ASSERT("Failed to initialize context", main_coap_context != NULL); if (coap_dtls_is_supported()) { coap_dtls_spsk_t setup_data; memset(&setup_data, 0, sizeof(setup_data)); setup_data.version = COAP_DTLS_SPSK_SETUP_VERSION; setup_data.psk_info.key.s = (const uint8_t *)use_psk; setup_data.psk_info.key.length = strlen(use_psk); coap_context_set_psk2(main_coap_context, &setup_data); } node.s = (const uint8_t *)"::"; node.length = 2; scheme_hint_bits = coap_get_available_scheme_hint_bits(use_psk[0], 0, COAP_PROTO_NONE); info_list = coap_resolve_address_info(&node, 0, 0, 0, 0, 0, scheme_hint_bits, COAP_RESOLVE_TYPE_LOCAL); for (info = info_list; info != NULL; info = info->next) { coap_endpoint_t *ep; ep = coap_new_endpoint(main_coap_context, &info->addr, info->proto); if (!ep) { coap_log_warn("cannot create endpoint for proto %u\n", info->proto); } else { have_ep = 1; } } coap_free_address_info(info_list); LWIP_ASSERT("Failed to initialize context", have_ep != 0); /* Limit the number of idle sessions to save RAM (MEMP_NUM_COAPSESSION) */ LWIP_ASSERT("Need a minimum of 2 for MEMP_NUM_COAPSESSION", MEMP_NUM_COAPSESSION > 1); coap_context_set_max_idle_sessions(main_coap_context, MEMP_NUM_COAPSESSION -1); clock_offset = 1; /* Need a non-zero value */ init_coap_resources(main_coap_context); coap_lwip_set_input_wait_handler(main_coap_context, input_wait, input_arg); } void server_coap_finished(void) { coap_free_context(main_coap_context); main_coap_context = NULL; coap_cleanup(); } void server_coap_poll(void) { static coap_time_t last_time = 0; coap_tick_t ticks_now; coap_time_t time_now; coap_io_process(main_coap_context, 1000); coap_ticks(&ticks_now); time_now = coap_ticks_to_rt(ticks_now); if (last_time != time_now) { /* This takes place once a second */ last_time = time_now; coap_resource_notify_observers(time_resource, NULL); } coap_check_notify(main_coap_context); }