51 lines
1.8 KiB
C
51 lines
1.8 KiB
C
// 利用 setsocketopt() 使用嵌套字支持广播，并编写两个程序，其中一个发送广播数据，另一个接收广播数据
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// 服务端
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include <sys/types.h>
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#include <sys/socket.h>
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#include <netinet/in.h>
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#include <arpa/inet.h>
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int main(int argc, char const *argv[])
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{
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int sockfd = socket(AF_INET, SOCK_DGRAM, 0); // 创建UDP套接字
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if (sockfd < 0)
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{
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perror("socket error");
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exit(1);
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}
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char broadcast_msg[] = "this is a udp broadcast message"; // 广播消息
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// 构造广播地址信息结构体对象
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struct sockaddr_in broadcast_addr; // 广播地址信息结构体对象
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memset(&broadcast_addr, 0, sizeof(broadcast_addr)); // 初始化广播地址信息结构体对象
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broadcast_addr.sin_family = AF_INET; // 设置地址族
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broadcast_addr.sin_port = htons(8000); // 设置端口号
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broadcast_addr.sin_addr.s_addr = inet_addr("255.255.255.255"); // 设置广播地址
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// 设置套接字选项，允许发送广播消息
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int broadcast_enable_flag = 1;
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// 说明：SOL_SOCKET表示当前套接字，SO_BROADCAST表示允许发送广播消息，&broadcast_enable_flag表示设置选项的值，sizeof(flag)表示选项值的大小
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int ret = setsockopt(sockfd, SOL_SOCKET, SO_BROADCAST, &broadcast_enable_flag, sizeof(broadcast_enable_flag));
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// 发送广播消息
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ssize_t send_len = sendto(sockfd, broadcast_msg, strlen(broadcast_msg), 0, (struct sockaddr *)&broadcast_addr, sizeof(broadcast_addr));
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if (send_len < 0)
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{
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perror("sendto error");
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exit(1);
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}
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printf("广播消息发送成功 (%s)\n", broadcast_msg);
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// 关闭套接字
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close(sockfd);
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return 0;
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}
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