Esp8266 网络结构体

Esp8266建立网络连接相关结构体如下：

结构体头文件espconn.h

/** Protocol family and type of the espconn */
enum espconn_type {
    ESPCONN_INVALID    = 0,
    /* ESPCONN_TCP Group */
    ESPCONN_TCP        = 0x10,
    /* ESPCONN_UDP Group */
    ESPCONN_UDP        = 0x20,
};

/** Current state of the espconn. Non-TCP espconn are always in state ESPCONN_NONE! */
enum espconn_state {
    ESPCONN_NONE,
    ESPCONN_WAIT,
    ESPCONN_LISTEN,
    ESPCONN_CONNECT,
    ESPCONN_WRITE,
    ESPCONN_READ,
    ESPCONN_CLOSE
};
typedef struct _esp_tcp {
    int remote_port;
    int local_port;
    uint8 local_ip[4];
    uint8 remote_ip[4];
    espconn_connect_callback connect_callback;
    espconn_reconnect_callback reconnect_callback;
    espconn_connect_callback disconnect_callback;
	espconn_connect_callback write_finish_fn;
} esp_tcp;

typedef struct _esp_udp {
    int remote_port;
    int local_port;
    uint8 local_ip[4];
	uint8 remote_ip[4];
} esp_udp;

/** A callback prototype to inform about events for a espconn */
typedef void (* espconn_recv_callback)(void *arg, char *pdata, unsigned short len);
typedef void (* espconn_sent_callback)(void *arg);

/** A espconn descriptor */
struct espconn {
    /** type of the espconn (TCP, UDP) */
    enum espconn_type type;
    /** current state of the espconn */
    enum espconn_state state;
    union {
        esp_tcp *tcp;
        esp_udp *udp;
    } proto;
    /** A callback function that is informed about events for this espconn */
    espconn_recv_callback recv_callback;
    espconn_sent_callback sent_callback;
    uint8 link_cnt;
    void *reverse;
};

域名解析相关

/******************************************************************************
 * TypedefName : dns_found_callback
 * Description : Callback which is invoked when a hostname is found.
 * Parameters  : name -- pointer to the name that was looked up.
 *               ipaddr -- pointer to an ip_addr_t containing the IP address of
 *               the hostname, or NULL if the name could not be found (or on any
 *               other error).
 *               callback_arg -- a user-specified callback argument passed to
 *               dns_gethostbyname
*******************************************************************************/

typedef void (*dns_found_callback)(const char *name, ip_addr_t *ipaddr, void *callback_arg);

/******************************************************************************
 * FunctionName : espconn_gethostbyname
 * Description  : Resolve a hostname (string) into an IP address.
 * Parameters   : pespconn -- espconn to resolve a hostname
 *                hostname -- the hostname that is to be queried
 *                addr -- pointer to a ip_addr_t where to store the address if
 *                it is already cached in the dns_table (only valid if ESPCONN_OK
 *                is returned!)
 *                found -- a callback function to be called on success, failure
 *                or timeout (only if ERR_INPROGRESS is returned!)
 * Returns      : err_t return code
 *                - ESPCONN_OK if hostname is a valid IP address string or the host
 *                  name is already in the local names table.
 *                - ESPCONN_INPROGRESS enqueue a request to be sent to the DNS server
 *                  for resolution if no errors are present.
 *                - ESPCONN_ARG: dns client not initialized or invalid hostname
*******************************************************************************/

err_t espconn_gethostbyname(struct espconn *pespconn, const char *hostname, ip_addr_t *addr, dns_found_callback found);

建立连接步骤示例（Tcp，直接连接ip）

    struct espconn pro_TcpClient_conn;//连接结构体
    pro_TcpClient_conn.type = ESPCONN_TCP;//TCP
    pro_TcpClient_conn.state = ESPCONN_NONE;//连接初始状态
    pro_TcpClient_conn.proto.tcp = (esp_tcp *)os_zalloc(sizeof(esp_tcp));//初始化Tcp连接结构体
    os_memcpy(pro_TcpClient_conn.proto.tcp->remote_ip, user_param.remote_server_ip, 4);//用户服务器ip地址
    pro_TcpClient_conn.proto.tcp->remote_port = user_param.remote_port;   // remote port//用户服务器端口
    pro_TcpClient_conn.proto.tcp->local_port = espconn_port(); //配置自动本地端口
    espconn_regist_connectcb(&pro_TcpClient_conn, pro_client_connect_cb); // 注册连接回调
    espconn_regist_reconcb(&pro_TcpClient_conn, pro_client_recon_cb); // 注册重连回调
    espconn_connect(&pro_TcpClient_conn);//开始连接

建立连接步骤示例（Tcp，连接域名）

#define NET_DOMAIN "fofso.com"//连接域名
LOCAL os_timer_t test_timer;//定时器
LOCAL struct espconn user_tcp_conn;//Esp网络相关结构体
LOCAL struct _esp_tcp user_tcp;//Tcp结构体
ip_addr_t tcp_server_ip;//ip地址

/******************************************************************************
 * FunctionName : user_tcp_recv_cb
 * Description  : receive callback.
 * Parameters   : arg -- Additional argument to pass to the callback function
 * Returns      : none
*******************************************************************************/
LOCAL void ICACHE_FLASH_ATTR
user_tcp_recv_cb(void *arg, char *pusrdata, unsigned short length)
{
   //received some data from tcp connection
    os_printf("tcp recv !!! %s \r\n", pusrdata);
}

/******************************************************************************
 * FunctionName : user_tcp_sent_cb
 * Description  : data sent callback.
 * Parameters   : arg -- Additional argument to pass to the callback function
 * Returns      : none
*******************************************************************************/
LOCAL void ICACHE_FLASH_ATTR
user_tcp_sent_cb(void *arg)
{
   //data sent successfully
    os_printf("tcp sent succeed !!! \r\n");
}

/******************************************************************************
 * FunctionName : user_tcp_discon_cb
 * Description  : disconnect callback.
 * Parameters   : arg -- Additional argument to pass to the callback function
 * Returns      : none
*******************************************************************************/
LOCAL void ICACHE_FLASH_ATTR
user_tcp_discon_cb(void *arg)
{
   //tcp disconnect successfully
    os_printf("tcp disconnect succeed !!! \r\n");
}

/******************************************************************************
 * FunctionName : user_esp_platform_sent
 * Description  : Processing the application data and sending it to the host
 * Parameters   : pespconn -- the espconn used to connetion with the host
 * Returns      : none
*******************************************************************************/
LOCAL void ICACHE_FLASH_ATTR
user_sent_data(struct espconn *pespconn)
{
    char *pbuf = (char *)os_zalloc(packet_size);
    os_sprintf(pbuf, pheadbuffer, NET_DOMAIN);
   espconn_sent(pespconn, pbuf, os_strlen(pbuf));
   os_free(pbuf);
}

/******************************************************************************
 * FunctionName : user_tcp_connect_cb
 * Description  : A new incoming tcp connection has been connected.
 * Parameters   : arg -- Additional argument to pass to the callback function
 * Returns      : none
*******************************************************************************/
LOCAL void ICACHE_FLASH_ATTR
user_tcp_connect_cb(void *arg)
{
    struct espconn *pespconn = arg;
    os_printf("connect succeed !!! \r\n");
    espconn_regist_recvcb(pespconn, user_tcp_recv_cb);
    espconn_regist_sentcb(pespconn, user_tcp_sent_cb);
   espconn_regist_disconcb(pespconn, user_tcp_discon_cb);
    user_sent_data(pespconn);
}

/******************************************************************************
 * FunctionName : user_tcp_recon_cb
 * Description  : reconnect callback, error occured in TCP connection.
 * Parameters   : arg -- Additional argument to pass to the callback function
 * Returns      : none
*******************************************************************************/
LOCAL void ICACHE_FLASH_ATTR
user_tcp_recon_cb(void *arg, sint8 err)
{
   //error occured , tcp connection broke. user can try to reconnect here.
    os_printf("reconnect callback, error code %d !!! \r\n",err);
}

#ifdef DNS_ENABLE
/******************************************************************************
 * FunctionName : user_dns_found
 * Description  : dns found callback
 * Parameters   : name -- pointer to the name that was looked up.
 *                ipaddr -- pointer to an ip_addr_t containing the IP address of
 *                the hostname, or NULL if the name could not be found (or on any
 *                other error).
 *                callback_arg -- a user-specified callback argument passed to
 *                dns_gethostbyname
 * Returns      : none
*******************************************************************************/
LOCAL void ICACHE_FLASH_ATTR
user_dns_found(const char *name, ip_addr_t *ipaddr, void *arg)
{
    struct espconn *pespconn = (struct espconn *)arg;

    if (ipaddr == NULL)
   {
        os_printf("user_dns_found NULL \r\n");
        return;
    }
   //dns got ip
    os_printf("user_dns_found %d.%d.%d.%d \r\n",
            *((uint8 *)&ipaddr->addr), *((uint8 *)&ipaddr->addr + 1),
            *((uint8 *)&ipaddr->addr + 2), *((uint8 *)&ipaddr->addr + 3));
    if (tcp_server_ip.addr == 0 && ipaddr->addr != 0)
   {
      // dns succeed, create tcp connection
        os_timer_disarm(&test_timer);
        tcp_server_ip.addr = ipaddr->addr;
        os_memcpy(pespconn->proto.tcp->remote_ip, &ipaddr->addr, 4); // remote ip of tcp server which get by dns
        pespconn->proto.tcp->remote_port =  user_param.remote_port;
        pespconn->proto.tcp->local_port = espconn_port(); //local port of ESP8266
        espconn_regist_connectcb(pespconn, user_tcp_connect_cb); // register connect callback
        espconn_regist_reconcb(pespconn, user_tcp_recon_cb); // register reconnect callback as error handler

        espconn_connect(pespconn); // tcp connect
    }
}

/******************************************************************************
 * FunctionName : user_esp_platform_dns_check_cb
 * Description  : 1s time callback to check dns found
 * Parameters   : arg -- Additional argument to pass to the callback function
 * Returns      : none
*******************************************************************************/
LOCAL void ICACHE_FLASH_ATTR
user_dns_check_cb(void *arg)
{
    struct espconn *pespconn = arg;
    espconn_gethostbyname(pespconn, NET_DOMAIN, &tcp_server_ip, user_dns_found); // recall DNS function
    os_timer_arm(&test_timer, 1000, 0);
}
#endif
/******************************************************************************
 * FunctionName : user_check_ip
 * Description  : check whether get ip addr or not
 * Parameters   : none
 * Returns      : none
*******************************************************************************/
void ICACHE_FLASH_ATTR
user_check_ip(void)
{
    struct ip_info ipconfig;

   //disarm timer first
    os_timer_disarm(&test_timer);

   //get ip info of ESP8266 station
    wifi_get_ip_info(STATION_IF, &ipconfig);

    if (wifi_station_get_connect_status() == STATION_GOT_IP && ipconfig.ip.addr != 0)
   {
      os_printf("got ip !!! \r\n");
      // Connect to tcp server as NET_DOMAIN
      user_tcp_conn.proto.tcp = &user_tcp;
      user_tcp_conn.type = ESPCONN_TCP;
      user_tcp_conn.state = ESPCONN_NONE;

#ifdef DNS_ENABLE
      tcp_server_ip.addr = 0;
       espconn_gethostbyname(&user_tcp_conn, NET_DOMAIN, &tcp_server_ip, user_dns_found); // DNS function
       os_timer_setfn(&test_timer, (os_timer_func_t *)user_dns_check_cb, &user_tcp_conn);
       os_timer_arm(&test_timer, 1000, 0);
#else
        const char esp_tcp_server_ip[4] = {X, X, X, X}; // remote IP of TCP server
       os_memcpy(user_tcp_conn.proto.tcp->remote_ip, esp_tcp_server_ip, 4);
       user_tcp_conn.proto.tcp->remote_port = user_param.remote_port;
       user_tcp_conn.proto.tcp->local_port = espconn_port(); //local port of ESP8266
       espconn_regist_connectcb(&user_tcp_conn, user_tcp_connect_cb); // register connect callback
       espconn_regist_reconcb(&user_tcp_conn, user_tcp_recon_cb); // register reconnect callback as error handler
       espconn_connect(&user_tcp_conn);
#endif
    }
   else
   {
        if ((wifi_station_get_connect_status() == STATION_WRONG_PASSWORD ||
                wifi_station_get_connect_status() == STATION_NO_AP_FOUND ||
                wifi_station_get_connect_status() == STATION_CONNECT_FAIL))
        {
         os_printf("connect fail !!! \r\n");
        }
      else
      {
           //re-arm timer to check ip
            os_timer_setfn(&test_timer, (os_timer_func_t *)user_check_ip, NULL);
            os_timer_arm(&test_timer, 100, 0);
        }
    }
}