123 lines
3.5 KiB
C
123 lines
3.5 KiB
C
#include <rtthread.h>
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#include <lwip/netdb.h> /* 为了解析主机名，需要包含netdb.h头文件 */
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#include <lwip/sockets.h> /* 使用BSD socket，需要包含sockets.h头文件 */
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#define BUFSZ 1024
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static const char send_data[] = "This is TCP Client from RT-Thread."; /* 发送用到的数据 */
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void tcpclient(const char* url, int port)
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{
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int ret;
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char *recv_data;
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struct hostent *host;
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int sock, bytes_received;
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struct sockaddr_in server_addr;
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/* 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） */
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host = gethostbyname(url);
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/* 分配用于存放接收数据的缓冲 */
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recv_data = rt_malloc(BUFSZ);
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if (recv_data == RT_NULL)
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{
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rt_kprintf("No memory\n");
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return;
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}
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/* 创建一个socket，类型是SOCKET_STREAM，TCP类型 */
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if ((sock = socket(AF_INET, SOCK_STREAM, 0)) == -1)
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{
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/* 创建socket失败 */
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rt_kprintf("Socket error\n");
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/* 释放接收缓冲 */
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rt_free(recv_data);
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return;
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}
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/* 初始化预连接的服务端地址 */
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server_addr.sin_family = AF_INET;
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server_addr.sin_port = htons(port);
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server_addr.sin_addr = *((struct in_addr *)host->h_addr);
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rt_memset(&(server_addr.sin_zero), 0, sizeof(server_addr.sin_zero));
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/* 连接到服务端 */
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if (connect(sock, (struct sockaddr *)&server_addr, sizeof(struct sockaddr)) == -1)
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{
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/* 连接失败 */
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rt_kprintf("Connect fail!\n");
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lwip_close(sock);
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/*释放接收缓冲 */
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rt_free(recv_data);
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return;
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}
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while(1)
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{
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/* 从sock连接中接收最大BUFSZ - 1字节数据 */
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bytes_received = recv(sock, recv_data, BUFSZ - 1, 0);
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if (bytes_received < 0)
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{
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/* 接收失败，关闭这个连接 */
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lwip_close(sock);
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rt_kprintf("\nreceived error,close the socket.\r\n");
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/* 释放接收缓冲 */
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rt_free(recv_data);
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break;
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}
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else if (bytes_received == 0)
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{
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/* 打印recv函数返回值为0的警告信息 */
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rt_kprintf("\nReceived warning,recv function return 0.\r\n");
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continue;
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}
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/* 有接收到数据，把末端清零 */
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recv_data[bytes_received] = '\0';
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if (strcmp(recv_data , "q") == 0 || strcmp(recv_data , "Q") == 0)
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{
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/* 如果是首字母是q或Q，关闭这个连接 */
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lwip_close(sock);
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rt_kprintf("\n got a 'q' or 'Q',close the socket.\r\n");
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/* 释放接收缓冲 */
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rt_free(recv_data);
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break;
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}
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else
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{
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/* 在控制终端显示收到的数据 */
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rt_kprintf("\nReceived data = %s " , recv_data);
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}
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/* 发送数据到sock连接 */
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ret = send(sock,send_data,strlen(send_data), 0);
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if (ret < 0)
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{
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/* 接收失败，关闭这个连接 */
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lwip_close(sock);
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rt_kprintf("\nsend error,close the socket.\r\n");
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rt_free(recv_data);
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break;
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}
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else if (ret == 0)
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{
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/* 打印send函数返回值为0的警告信息 */
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rt_kprintf("\n Send warning,send function return 0.\r\n");
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}
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}
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return;
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}
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#ifdef RT_USING_FINSH
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#include <finsh.h>
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/* 输出tcpclient函数到finsh shell中 */
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FINSH_FUNCTION_EXPORT(tcpclient, startup tcp client);
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#endif
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