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	esp_netif_init() returns standard esp_err_t error code (unlike tcpip_adapter init), so shall be checked for the return value Also to make the initialization code more consistent.
		
			
				
	
	
		
			454 lines
		
	
	
		
			16 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			454 lines
		
	
	
		
			16 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* CoAP client Example
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   This example code is in the Public Domain (or CC0 licensed, at your option.)
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   Unless required by applicable law or agreed to in writing, this
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   software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
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   CONDITIONS OF ANY KIND, either express or implied.
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*/
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/*
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 * WARNING
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 * libcoap is not multi-thread safe, so only this thread must make any coap_*()
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 * calls.  Any external (to this thread) data transmitted in/out via libcoap
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 * therefore has to be passed in/out by xQueue*() via this thread.
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 */
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#include <string.h>
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#include <sys/socket.h>
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#include <netdb.h>
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#include <sys/param.h>
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#include "freertos/FreeRTOS.h"
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#include "freertos/task.h"
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#include "freertos/event_groups.h"
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#include "esp_log.h"
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#include "esp_wifi.h"
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#include "esp_event.h"
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#include "nvs_flash.h"
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#include "protocol_examples_common.h"
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#if 1
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/* Needed until coap_dtls.h becomes a part of libcoap proper */
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#include "libcoap.h"
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#include "coap_dtls.h"
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#endif
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#include "coap.h"
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#define COAP_DEFAULT_TIME_SEC 5
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/* The examples use simple Pre-Shared-Key configuration that you can set via
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   'make menuconfig'.
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   If you'd rather not, just change the below entries to strings with
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   the config you want - ie #define EXAMPLE_COAP_PSK_KEY "some-agreed-preshared-key"
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   Note: PSK will only be used if the URI is prefixed with coaps://
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   instead of coap:// and the PSK must be one that the server supports
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   (potentially associated with the IDENTITY)
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*/
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#define EXAMPLE_COAP_PSK_KEY CONFIG_EXAMPLE_COAP_PSK_KEY
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#define EXAMPLE_COAP_PSK_IDENTITY CONFIG_EXAMPLE_COAP_PSK_IDENTITY
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/* The examples use uri Logging Level that
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   you can set via 'make menuconfig'.
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   If you'd rather not, just change the below entry to a value
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   that is between 0 and 7 with
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   the config you want - ie #define EXAMPLE_COAP_LOG_DEFAULT_LEVEL 7
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*/
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#define EXAMPLE_COAP_LOG_DEFAULT_LEVEL CONFIG_COAP_LOG_DEFAULT_LEVEL
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/* The examples use uri "coap://californium.eclipse.org" that
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   you can set via the project configuration (idf.py menuconfig)
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   If you'd rather not, just change the below entries to strings with
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   the config you want - ie #define COAP_DEFAULT_DEMO_URI "coaps://californium.eclipse.org"
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*/
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#define COAP_DEFAULT_DEMO_URI CONFIG_EXAMPLE_TARGET_DOMAIN_URI
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const static char *TAG = "CoAP_client";
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static int resp_wait = 1;
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static coap_optlist_t *optlist = NULL;
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static int wait_ms;
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#ifdef CONFIG_COAP_MBEDTLS_PKI
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/* CA cert, taken from coap_ca.pem
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   Client cert, taken from coap_client.crt
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   Client key, taken from coap_client.key
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   The PEM, CRT and KEY file are examples taken from the wpa2 enterprise
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   example.
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   To embed it in the app binary, the PEM, CRT and KEY file is named
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   in the component.mk COMPONENT_EMBED_TXTFILES variable.
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 */
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extern uint8_t ca_pem_start[] asm("_binary_coap_ca_pem_start");
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extern uint8_t ca_pem_end[]   asm("_binary_coap_ca_pem_end");
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extern uint8_t client_crt_start[] asm("_binary_coap_client_crt_start");
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extern uint8_t client_crt_end[]   asm("_binary_coap_client_crt_end");
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extern uint8_t client_key_start[] asm("_binary_coap_client_key_start");
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extern uint8_t client_key_end[]   asm("_binary_coap_client_key_end");
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#endif /* CONFIG_COAP_MBEDTLS_PKI */
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static void message_handler(coap_context_t *ctx, coap_session_t *session,
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                            coap_pdu_t *sent, coap_pdu_t *received,
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                            const coap_tid_t id)
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{
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    unsigned char *data = NULL;
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    size_t data_len;
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    coap_pdu_t *pdu = NULL;
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    coap_opt_t *block_opt;
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    coap_opt_iterator_t opt_iter;
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    unsigned char buf[4];
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    coap_optlist_t *option;
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    coap_tid_t tid;
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    if (COAP_RESPONSE_CLASS(received->code) == 2) {
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        /* Need to see if blocked response */
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        block_opt = coap_check_option(received, COAP_OPTION_BLOCK2, &opt_iter);
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        if (block_opt) {
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            uint16_t blktype = opt_iter.type;
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            if (coap_opt_block_num(block_opt) == 0) {
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                printf("Received:\n");
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            }
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            if (coap_get_data(received, &data_len, &data)) {
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                printf("%.*s", (int)data_len, data);
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            }
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            if (COAP_OPT_BLOCK_MORE(block_opt)) {
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                /* more bit is set */
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                /* create pdu with request for next block */
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                pdu = coap_new_pdu(session);
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                if (!pdu) {
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                    ESP_LOGE(TAG, "coap_new_pdu() failed");
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                    goto clean_up;
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                }
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                pdu->type = COAP_MESSAGE_CON;
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                pdu->tid = coap_new_message_id(session);
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                pdu->code = COAP_REQUEST_GET;
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                /* add URI components from optlist */
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                for (option = optlist; option; option = option->next ) {
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                    switch (option->number) {
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                    case COAP_OPTION_URI_HOST :
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                    case COAP_OPTION_URI_PORT :
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                    case COAP_OPTION_URI_PATH :
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                    case COAP_OPTION_URI_QUERY :
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                        coap_add_option(pdu, option->number, option->length,
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                                        option->data);
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                        break;
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                    default:
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                        ;     /* skip other options */
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                    }
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                }
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                /* finally add updated block option from response, clear M bit */
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                /* blocknr = (blocknr & 0xfffffff7) + 0x10; */
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                coap_add_option(pdu,
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                                blktype,
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                                coap_encode_var_safe(buf, sizeof(buf),
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                                                     ((coap_opt_block_num(block_opt) + 1) << 4) |
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                                                     COAP_OPT_BLOCK_SZX(block_opt)), buf);
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                tid = coap_send(session, pdu);
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                if (tid != COAP_INVALID_TID) {
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                    resp_wait = 1;
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                    wait_ms = COAP_DEFAULT_TIME_SEC * 1000;
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                    return;
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                }
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            }
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            printf("\n");
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        } else {
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            if (coap_get_data(received, &data_len, &data)) {
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                printf("Received: %.*s\n", (int)data_len, data);
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            }
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        }
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    }
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clean_up:
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    resp_wait = 0;
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}
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#ifdef CONFIG_COAP_MBEDTLS_PKI
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static int
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verify_cn_callback(const char *cn,
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                   const uint8_t *asn1_public_cert,
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                   size_t asn1_length,
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                   coap_session_t *session,
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                   unsigned depth,
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                   int validated,
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                   void *arg
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                  )
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{
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    coap_log(LOG_INFO, "CN '%s' presented by server (%s)\n",
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             cn, depth ? "CA" : "Certificate");
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    return 1;
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}
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#endif /* CONFIG_COAP_MBEDTLS_PKI */
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static void coap_example_client(void *p)
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{
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    struct hostent *hp;
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    coap_address_t    dst_addr;
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    static coap_uri_t uri;
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    const char       *server_uri = COAP_DEFAULT_DEMO_URI;
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    char *phostname = NULL;
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    coap_set_log_level(EXAMPLE_COAP_LOG_DEFAULT_LEVEL);
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    while (1) {
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#define BUFSIZE 40
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        unsigned char _buf[BUFSIZE];
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        unsigned char *buf;
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        size_t buflen;
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        int res;
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        coap_context_t *ctx = NULL;
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        coap_session_t *session = NULL;
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        coap_pdu_t *request = NULL;
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        optlist = NULL;
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        if (coap_split_uri((const uint8_t *)server_uri, strlen(server_uri), &uri) == -1) {
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            ESP_LOGE(TAG, "CoAP server uri error");
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            break;
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        }
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        if (uri.scheme == COAP_URI_SCHEME_COAPS && !coap_dtls_is_supported()) {
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            ESP_LOGE(TAG, "MbedTLS (D)TLS Client Mode not configured");
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            break;
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        }
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        if (uri.scheme == COAP_URI_SCHEME_COAPS_TCP && !coap_tls_is_supported()) {
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            ESP_LOGE(TAG, "CoAP server uri coaps+tcp:// scheme is not supported");
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            break;
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        }
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        phostname = (char *)calloc(1, uri.host.length + 1);
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        if (phostname == NULL) {
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            ESP_LOGE(TAG, "calloc failed");
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            break;
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        }
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        memcpy(phostname, uri.host.s, uri.host.length);
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        hp = gethostbyname(phostname);
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        free(phostname);
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        if (hp == NULL) {
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            ESP_LOGE(TAG, "DNS lookup failed");
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            vTaskDelay(1000 / portTICK_PERIOD_MS);
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            free(phostname);
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            continue;
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        }
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        char tmpbuf[INET6_ADDRSTRLEN];
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        coap_address_init(&dst_addr);
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        switch (hp->h_addrtype) {
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            case AF_INET:
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                dst_addr.addr.sin.sin_family      = AF_INET;
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                dst_addr.addr.sin.sin_port        = htons(uri.port);
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                memcpy(&dst_addr.addr.sin.sin_addr, hp->h_addr, sizeof(dst_addr.addr.sin.sin_addr));
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                inet_ntop(AF_INET, &dst_addr.addr.sin.sin_addr, tmpbuf, sizeof(tmpbuf));
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                ESP_LOGI(TAG, "DNS lookup succeeded. IP=%s", tmpbuf);
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                break;
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            case AF_INET6:
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                dst_addr.addr.sin6.sin6_family      = AF_INET6;
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                dst_addr.addr.sin6.sin6_port        = htons(uri.port);
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                memcpy(&dst_addr.addr.sin6.sin6_addr, hp->h_addr, sizeof(dst_addr.addr.sin6.sin6_addr));
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                inet_ntop(AF_INET6, &dst_addr.addr.sin6.sin6_addr, tmpbuf, sizeof(tmpbuf));
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                ESP_LOGI(TAG, "DNS lookup succeeded. IP=%s", tmpbuf);
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                break;
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            default:
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                ESP_LOGE(TAG, "DNS lookup response failed");
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                goto clean_up;
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        }
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        if (uri.path.length) {
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            buflen = BUFSIZE;
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            buf = _buf;
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            res = coap_split_path(uri.path.s, uri.path.length, buf, &buflen);
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            while (res--) {
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                coap_insert_optlist(&optlist,
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                                    coap_new_optlist(COAP_OPTION_URI_PATH,
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                                                     coap_opt_length(buf),
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                                                     coap_opt_value(buf)));
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                buf += coap_opt_size(buf);
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            }
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        }
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        if (uri.query.length) {
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            buflen = BUFSIZE;
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            buf = _buf;
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            res = coap_split_query(uri.query.s, uri.query.length, buf, &buflen);
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            while (res--) {
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                coap_insert_optlist(&optlist,
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                                    coap_new_optlist(COAP_OPTION_URI_QUERY,
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                                                     coap_opt_length(buf),
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                                                     coap_opt_value(buf)));
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                buf += coap_opt_size(buf);
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            }
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        }
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        ctx = coap_new_context(NULL);
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        if (!ctx) {
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            ESP_LOGE(TAG, "coap_new_context() failed");
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            goto clean_up;
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        }
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        /*
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         * Note that if the URI starts with just coap:// (not coaps://) the
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         * session will still be plain text.
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         *
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         * coaps+tcp:// is NOT supported by the libcoap->mbedtls interface
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         * so COAP_URI_SCHEME_COAPS_TCP will have failed in a test above,
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         * but the code is left in for completeness.
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         */
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        if (uri.scheme == COAP_URI_SCHEME_COAPS || uri.scheme == COAP_URI_SCHEME_COAPS_TCP) {
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#ifndef CONFIG_MBEDTLS_TLS_CLIENT
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            ESP_LOGE(TAG, "MbedTLS (D)TLS Client Mode not configured");
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            goto clean_up;
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#endif /* CONFIG_MBEDTLS_TLS_CLIENT */
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#ifdef CONFIG_COAP_MBEDTLS_PSK
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            session = coap_new_client_session_psk(ctx, NULL, &dst_addr,
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                                                  uri.scheme == COAP_URI_SCHEME_COAPS ? COAP_PROTO_DTLS : COAP_PROTO_TLS,
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                                                  EXAMPLE_COAP_PSK_IDENTITY,
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                                                  (const uint8_t *)EXAMPLE_COAP_PSK_KEY,
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                                                  sizeof(EXAMPLE_COAP_PSK_KEY) - 1);
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#endif /* CONFIG_COAP_MBEDTLS_PSK */
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#ifdef CONFIG_COAP_MBEDTLS_PKI
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            unsigned int ca_pem_bytes = ca_pem_end - ca_pem_start;
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            unsigned int client_crt_bytes = client_crt_end - client_crt_start;
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            unsigned int client_key_bytes = client_key_end - client_key_start;
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            coap_dtls_pki_t dtls_pki;
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            static char client_sni[256];
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            memset (&dtls_pki, 0, sizeof(dtls_pki));
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            dtls_pki.version = COAP_DTLS_PKI_SETUP_VERSION;
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            if (ca_pem_bytes) {
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                /*
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                 * Add in additional certificate checking.
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                 * This list of enabled can be tuned for the specific
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                 * requirements - see 'man coap_encryption'.
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                 *
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                 * Note: A list of root ca file can be setup separately using
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                 * coap_context_set_pki_root_cas(), but the below is used to
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                 * define what checking actually takes place.
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                 */
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                dtls_pki.verify_peer_cert        = 1;
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                dtls_pki.require_peer_cert       = 1;
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                dtls_pki.allow_self_signed       = 1;
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                dtls_pki.allow_expired_certs     = 1;
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                dtls_pki.cert_chain_validation   = 1;
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                dtls_pki.cert_chain_verify_depth = 2;
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                dtls_pki.check_cert_revocation   = 1;
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                dtls_pki.allow_no_crl            = 1;
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                dtls_pki.allow_expired_crl       = 1;
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                dtls_pki.allow_bad_md_hash       = 1;
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                dtls_pki.allow_short_rsa_length  = 1;
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                dtls_pki.validate_cn_call_back   = verify_cn_callback;
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                dtls_pki.cn_call_back_arg        = NULL;
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                dtls_pki.validate_sni_call_back  = NULL;
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                dtls_pki.sni_call_back_arg       = NULL;
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                memset(client_sni, 0, sizeof(client_sni));
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                if (uri.host.length) {
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                    memcpy(client_sni, uri.host.s, MIN(uri.host.length, sizeof(client_sni)));
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                } else {
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                    memcpy(client_sni, "localhost", 9);
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                }
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                dtls_pki.client_sni = client_sni;
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            }
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            dtls_pki.pki_key.key_type = COAP_PKI_KEY_PEM_BUF;
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            dtls_pki.pki_key.key.pem_buf.public_cert = client_crt_start;
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            dtls_pki.pki_key.key.pem_buf.public_cert_len = client_crt_bytes;
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            dtls_pki.pki_key.key.pem_buf.private_key = client_key_start;
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            dtls_pki.pki_key.key.pem_buf.private_key_len = client_key_bytes;
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            dtls_pki.pki_key.key.pem_buf.ca_cert = ca_pem_start;
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            dtls_pki.pki_key.key.pem_buf.ca_cert_len = ca_pem_bytes;
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            session = coap_new_client_session_pki(ctx, NULL, &dst_addr,
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                                                  uri.scheme == COAP_URI_SCHEME_COAPS ? COAP_PROTO_DTLS : COAP_PROTO_TLS,
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                                                  &dtls_pki);
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#endif /* CONFIG_COAP_MBEDTLS_PKI */
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        } else {
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            session = coap_new_client_session(ctx, NULL, &dst_addr,
 | 
						|
                                              uri.scheme == COAP_URI_SCHEME_COAP_TCP ? COAP_PROTO_TCP :
 | 
						|
                                              COAP_PROTO_UDP);
 | 
						|
        }
 | 
						|
        if (!session) {
 | 
						|
            ESP_LOGE(TAG, "coap_new_client_session() failed");
 | 
						|
            goto clean_up;
 | 
						|
        }
 | 
						|
 | 
						|
        coap_register_response_handler(ctx, message_handler);
 | 
						|
 | 
						|
        request = coap_new_pdu(session);
 | 
						|
        if (!request) {
 | 
						|
            ESP_LOGE(TAG, "coap_new_pdu() failed");
 | 
						|
            goto clean_up;
 | 
						|
        }
 | 
						|
        request->type = COAP_MESSAGE_CON;
 | 
						|
        request->tid = coap_new_message_id(session);
 | 
						|
        request->code = COAP_REQUEST_GET;
 | 
						|
        coap_add_optlist_pdu(request, &optlist);
 | 
						|
 | 
						|
        resp_wait = 1;
 | 
						|
        coap_send(session, request);
 | 
						|
 | 
						|
        wait_ms = COAP_DEFAULT_TIME_SEC * 1000;
 | 
						|
 | 
						|
        while (resp_wait) {
 | 
						|
            int result = coap_run_once(ctx, wait_ms > 1000 ? 1000 : wait_ms);
 | 
						|
            if (result >= 0) {
 | 
						|
                if (result >= wait_ms) {
 | 
						|
                    ESP_LOGE(TAG, "select timeout");
 | 
						|
                    break;
 | 
						|
                } else {
 | 
						|
                    wait_ms -= result;
 | 
						|
                }
 | 
						|
            }
 | 
						|
        }
 | 
						|
clean_up:
 | 
						|
        if (optlist) {
 | 
						|
            coap_delete_optlist(optlist);
 | 
						|
            optlist = NULL;
 | 
						|
        }
 | 
						|
        if (session) {
 | 
						|
            coap_session_release(session);
 | 
						|
        }
 | 
						|
        if (ctx) {
 | 
						|
            coap_free_context(ctx);
 | 
						|
        }
 | 
						|
        coap_cleanup();
 | 
						|
        /*
 | 
						|
         * change the following line to something like sleep(2)
 | 
						|
         * if you want the request to continually be sent
 | 
						|
         */
 | 
						|
        break;
 | 
						|
    }
 | 
						|
 | 
						|
    vTaskDelete(NULL);
 | 
						|
}
 | 
						|
 | 
						|
void app_main(void)
 | 
						|
{
 | 
						|
    ESP_ERROR_CHECK( nvs_flash_init() );
 | 
						|
    ESP_ERROR_CHECK(esp_netif_init());
 | 
						|
    ESP_ERROR_CHECK(esp_event_loop_create_default());
 | 
						|
 | 
						|
    /* This helper function configures Wi-Fi or Ethernet, as selected in menuconfig.
 | 
						|
     * Read "Establishing Wi-Fi or Ethernet Connection" section in
 | 
						|
     * examples/protocols/README.md for more information about this function.
 | 
						|
     */
 | 
						|
    ESP_ERROR_CHECK(example_connect());
 | 
						|
 | 
						|
    xTaskCreate(coap_example_client, "coap", 8 * 1024, NULL, 5, NULL);
 | 
						|
}
 |