Compile Code Example mosquitto / openssl RK3288 on the client and MQTT

1, depending on the cross-compiled libraries openssl

(1) Configuration information compiler

setarch i386 ./config no-asm shared --cross-compile-prefix=arm-linux-androideabi-

(2) modify the Makefile

Delete -m32

(3) The compiler (Compiler specified)

make CC=arm-linux-androideabi-gcc CXX=arm-linux-androideabi-g++

2, the cross-compiler mosquitto

(1) modify the config.mk

WITH_STATIC_LIBRARIES:=yes

CFLAGS += -I/where_is_your_openssl_headerfiles/
LDFLAGS += -L/where_is_your_openssl_staticlib/

(2) Compile

make CC=arm-linux-androideabi-gcc CXX=arm-linux-androideabi-g++

3, based on the MQTT client mosquitto

Struct mqtt_conf code is a custom configuration, mqtt_send implementation is a doubly linked list queue.

void start_mqtt_module(struct mqtt_conf *conf)
{
    if (!conf->server || conf->server_port <= 0) {
        DEBUG_MSG("[%s] invalid parameters for mqtt module\n", THISFILE);
        return;
    }

    int rc = 0;

    DEBUG_MSG("init_default_mqtt_parameters clientid %s\n", conf->clientid);
    
    mosquitto_lib_init();

    mosq = mosquitto_new(conf->clientid, conf->clean_session, NULL);

    #ifdef MQTT_DEBUGLOG
    mosquitto_log_callback_set(mosq, log_callback);
    #endif

    mosquitto_connect_callback_set(mosq, on_connect);
    mosquitto_publish_callback_set(mosq, on_publish);
    mosquitto_disconnect_callback_set(mosq, on_disconnect);

    mosquitto_username_pw_set(mosq, conf->username, conf->password);

    //配置证书
    if (!conf->disable_ssl) {
        rc = mosquitto_tls_set(mosq,
                conf->cafile,
                conf->capath,
                conf->certfile,
                conf->keyfile,  /* Notice: DO NOT encrypt your private key */
                NULL            /* password callback */
                );
        if (MOSQ_ERR_SUCCESS != rc) {
            DEBUG_MSG("[%s] failed to set tls certification info\n", THISFILE);
        }

        rc = mosquitto_tls_opts_set(mosq, SSL_VERIFY_PEER, NULL, NULL);
        if (MOSQ_ERR_SUCCESS != rc) {
            DEBUG_MSG("[%s] failed to set tls option\n", THISFILE);
        }

        /* set this to false(default) means check server hostname under TLS protocol */
        rc = mosquitto_tls_insecure_set(mosq, true);
        if (MOSQ_ERR_SUCCESS != rc) {
            DEBUG_MSG("[%s] failed to set incecrue\n", THISFILE);
        }
    }
        //链接服务器
    do {
        rc = mosquitto_connect(mosq, conf->server, conf->server_port, 60);
        if (MOSQ_ERR_SUCCESS != rc) {
            DEBUG_MSG("[%s] failed to connect mqtt server %s:%d\n", ThisFile, conf -> Server, conf -> SERVER_PORT); 
        } 
    } the while (RC =! MOSQ_ERR_SUCCESS); 

    DEBUG_MSG ( " [% S] Connect MQTT Server% S:% D the OK \ n- " , thisFile, conf -> Server , conf -> SERVER_PORT); 

    set_queue_alive ( & mqtt_send); 

    SLEEP ( . 1 );
         // new thread timing for transmitting the PING the MQTT 
    create_function_thread (mqtt_loop, NULL); 

    struct mqtt_msg * MSG; 

    the while (RUN == - . 1 ) { 
        MSG = NULL;
                 // remove a message from the queue out PUB 
        msg = ( struct mqtt_msg *) dequeue (& mqtt_send);
        if (msg) {
            /* dispatch msg according to Qos */
            rc = mosquitto_publish(mosq, NULL, msg->topic, msg->datalen, msg->data, msg->qos, false);

            if (MOSQ_ERR_SUCCESS == rc) {
                DEBUG_MSG("[%s] mosquitto_publish success\n", THISFILE);
                mqtt_pubs_succ++;
            } else {
                DEBUG_MSG("[%s] mosquitto_publish failed %d\n", THISFILE, rc);
                mqtt_pubs_fail++;
            }

            free(msg);
        }
    }
    mosquitto_lib_cleanup();
}
/*
    MQTT ping and reply for keepalive
 */
void *mqtt_loop(void *arg)
{
    uint32_t cnt = 0;
    while (run == -1){
        int rc = mosquitto_loop(mosq, -1, 1);
        if (MOSQ_ERR_SUCCESS != rc) {
            DEBUG_MSG("[%s] mosquitto_loop error %d\n", THISFILE, rc);
            if (rc == MOSQ_ERR_ERRNO) {
                DEBUG_MSG("[%s] mosquitto_loop error %s, errno %d\n", THISFILE, strerror(errno), errno);
            }
            mosquitto_lib_cleanup();
            break;
        } else {
            //DEBUG_MSG("[%s] mosquitto_loop started! %d\n", THISFILE, cnt);
        }
        cnt++;
        //3s  keepalive
        usleep(DELTA_US);
    }

    return NULL;
}