123 lines
3.1 KiB
C
123 lines
3.1 KiB
C
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// 群聊(组播-多播)
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#include <stdio.h>
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#include <arpa/inet.h>
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#include <netinet/in.h>
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#include <sys/socket.h>
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#include <unistd.h>
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#include <string.h>
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#include <stdlib.h>
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#include <pthread.h>
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#include <sys/types.h>
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/*
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* ./a.out port
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*/
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void *recv_task(void *arg);
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void *send_task(void *arg);
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int bind_port;
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char groupip[16] = "";
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int main(int argc, char const *argv[])
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{
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if (argc < 3)
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{
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printf("usage: %s port groupip\n", argv[0]);
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return -1;
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}
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bind_port = atoi(argv[1]);
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strcpy(groupip, argv[2]); // 多播组ip
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int sock_fd = socket(AF_INET, SOCK_DGRAM, 0);
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if (sock_fd < 0)
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{
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perror("socket");
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return EXIT_FAILURE; // 1
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}
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// 绑定端口
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struct sockaddr_in bind_addr;
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memset(&bind_addr, 0, sizeof(bind_addr));
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bind_addr.sin_family = AF_INET;
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bind_addr.sin_port = htons(bind_port);
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bind_addr.sin_addr.s_addr = htonl(INADDR_ANY);
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bind(sock_fd, (struct sockaddr *)&bind_addr, sizeof(bind_addr)); // 绑定文件描述符和地址端口
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// 设置 socket 选项为多播(组号从命令行获取)
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struct ip_mreq group_mreq; // 组消息请求结构体对象
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group_mreq.imr_multiaddr.s_addr = inet_addr(groupip); // 添加多播组的ip
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group_mreq.imr_interface.s_addr = htonl(INADDR_ANY); // 当前主机的所有 ip 地址加入多播组中
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int ret = setsockopt(sock_fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &group_mreq, sizeof(group_mreq));
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if (ret != 0)
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{
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perror("setsockopt");
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}
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pthread_t tid1, tid2;
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pthread_create(&tid1, NULL, recv_task, &sock_fd);
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pthread_create(&tid2, NULL, send_task, &sock_fd);
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pthread_join(tid2, NULL);
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pthread_cancel(tid1);
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pthread_join(tid1, NULL);
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printf("---over---\n");
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close(sock_fd);
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return 0;
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}
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void *recv_task(void *arg)
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{
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int sock_fd = *((int *)arg);
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while (1)
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{
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struct sockaddr_in data_addr;
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socklen_t data_addr_len = sizeof(data_addr);
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bzero(&data_addr, data_addr_len);
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char buf[128] = "";
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ssize_t recv_len = recvfrom(sock_fd, buf, 128, 0, (struct sockaddr *)&data_addr, &data_addr_len);
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if (recv_len > 0)
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{
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char ip[16] = "";
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inet_ntop(AF_INET, &data_addr.sin_addr.s_addr, ip, 16);
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printf("%s(%d): %s\n", ip, ntohs(data_addr.sin_port), buf);
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}
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}
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}
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void *send_task(void *arg)
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{
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int sock_fd = *((int *)arg);
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while (1)
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{
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char buf[128] = "";
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if (fgets(buf, 128, stdin) != NULL)
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{
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buf[strlen(buf) - 1] = 0;
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struct sockaddr_in addr;
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bzero(&addr, sizeof(addr));
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addr.sin_family = AF_INET;
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addr.sin_port = htons(bind_port);
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addr.sin_addr.s_addr = inet_addr(groupip); // 一定是多播地址
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sendto(sock_fd, buf, strlen(buf) + 1, 0, (struct sockaddr *)&addr, sizeof(addr));
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if (strncmp(buf, "bye", 3) == 0)
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{
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break;
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}
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if (strncmp(buf, "clear", 5) == 0)
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{
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system("clear");
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}
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}
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}
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}
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