ESp8266的几个socket API函数

发布于 2022-05-01 14:26:17 浏览：775 订阅该版

crystal266 2022-05-01

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直接使用 `send()` 函数进行发送就行了，`send` 函数最终会调用到 `esp8266_socket_send()`，调用过程如下所示。按照TCP客户端的建立连接和数据发送接收流程编写就行。

```c
#define send(s, dataptr, size, flags)               sal_sendto(s, dataptr, size, flags, NULL, NULL) /* rt-thread/components/net/sal_socket/include/socket/sys_socket/sys/socket.h */
#define sendto(s, dataptr, size, flags, to, tolen)  sal_sendto(s, dataptr, size, flags, to, tolen)  /* rt-thread/components/net/sal_socket/include/socket/sys_socket/sys/socket.h */
    |-> sal_sendto                                                                 /* rt-thread/components/net/sal_socket/src/sal_socket.c */
        |-> SAL_SOCKET_OBJ_GET                                                     /* rt-thread/components/net/sal_socket/src/sal_socket.c */
        |-> SAL_NETDEV_IS_UP                                                       /* rt-thread/components/net/sal_socket/src/sal_socket.c */
        |-> SAL_NETDEV_SOCKETOPS_VALID                                             /* rt-thread/components/net/sal_socket/src/sal_socket.c */
        |-> pf->skt_ops->sendto                                                    /* rt-thread/components/net/sal_socket/src/sal_socket.c */
            |-> at_sendto                                                          /* rt-thread/components/net/at/at_socket/at_socket.c */
                |-> at_get_socket                                                  /* rt-thread/components/net/at/at_socket/at_socket.c */
                |-> sock->ops->at_send                                             /* rt-thread/components/net/at/at_socket/at_socket.c */
                    |-> esp8266_socket_send                                         /* packages/at_device-v2.0.4/class/esp8266/at_socket_esp8266.c 
```

八宝粥 2022-05-01

这家伙很懒，什么也没写！

crystal266 2022-05-01

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crystal266 2022-05-01

嵌入式

crystal266 2022-05-01

嵌入式

@八宝粥 使用方法参考下面的代码。文档参考官方 [SAL 套接字抽象层](https://www.rt-thread.org/document/site/#/rt-thread-version/rt-thread-standard/programming-manual/sal/sal?id=sal-%e7%ae%80%e4%bb%8b)

```c
#include <stdio.h>
#include <string.h>

#include <rtthread.h>
#include <sys/socket.h>
#include <netdb.h>

/* RT-Thread 官网，支持 TLS 功能 */
#define SAL_TLS_HOST    "www.rt-thread.org"
#define SAL_TLS_PORT    443
#define SAL_TLS_BUFSZ   1024

static const char *send_data = "GET /download/rt-thread.txt HTTP/1.1\r\n"
    "Host: www.rt-thread.org\r\n"
    "User-Agent: rtthread/4.0.1 rtt\r\n\r\n";

void sal_tls_test(void)
{
    int ret, i;
    char *recv_data;
    struct hostent *host;
    int sock = -1, bytes_received;
    struct sockaddr_in server_addr;

/* 通过函数入口参数url获得host地址（如果是域名，会做域名解析） */
    host = gethostbyname(SAL_TLS_HOST);

recv_data = rt_calloc(1, SAL_TLS_BUFSZ);
    if (recv_data == RT_NULL)
    {
        rt_kprintf("No memory\n");
        return;
    }

/* 创建一个socket，类型是SOCKET_STREAM，TCP 协议, TLS 类型 */
    if ((sock = socket(AF_INET, SOCK_STREAM, PROTOCOL_TLS)) < 0)
    {
        rt_kprintf("Socket error\n");
        goto __exit;
    }

/* 初始化预连接的服务端地址 */
    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(SAL_TLS_PORT);
    server_addr.sin_addr = *((struct in_addr *)host->h_addr);
    rt_memset(&(server_addr.sin_zero), 0, sizeof(server_addr.sin_zero));

if (connect(sock, (struct sockaddr *)&server_addr, sizeof(struct sockaddr)) < 0)
    {
        rt_kprintf("Connect fail!\n");
        goto __exit;
    }

/* 发送数据到 socket 连接 */
    ret = send(sock, send_data, strlen(send_data), 0);
    if (ret <= 0)
    {
        rt_kprintf("send error,close the socket.\n");
        goto __exit;
    }

/* 接收并打印响应的数据，使用加密数据传输 */
    bytes_received = recv(sock, recv_data, SAL_TLS_BUFSZ  - 1, 0);
    if (bytes_received <= 0)
    {
        rt_kprintf("received error,close the socket.\n");
        goto __exit;
    }

rt_kprintf("recv data:\n");
    for (i = 0; i < bytes_received; i++)
    {
        rt_kprintf("%c", recv_data[i]);
    }

__exit:
    if (recv_data)
        rt_free(recv_data);

if (sock >= 0)
        closesocket(sock);
}

#ifdef FINSH_USING_MSH
#include <finsh.h>
MSH_CMD_EXPORT(sal_tls_test, SAL TLS function test);
#endif /* FINSH_USING_MSH */

```