广播
#include <stdio.h> #include <stdlib.h> #include <sys/types.h> #include <sys/socket.h> #include <string.h> #include <unistd.h> #include <arpa/inet.h> #include <net/if.h> #define SERVER_PORT 8000 #define CLIENT_PORT 9000 #define MAXLINE 1500 #define BROADCAST_IP "192.168.32.255" int main(void) { int sockfd; struct sockaddr_in serveraddr, clientaddr; char buf[MAXLINE] = "xingwenpeng\n"; /* 构造用于UDP通信的套接字 */ sockfd = socket(AF_INET, SOCK_DGRAM, 0); bzero(&serveraddr, sizeof(serveraddr)); serveraddr.sin_family = AF_INET; /* IPv4 */ serveraddr.sin_addr.s_addr = htonl(INADDR_ANY); /* 本地任意IP INADDR_ANY = 0 */ serveraddr.sin_port = htons(SERVER_PORT); bind(sockfd, (struct sockaddr *)&serveraddr, sizeof(serveraddr)); int flag = 1; setsockopt(sockfd, SOL_SOCKET, SO_BROADCAST, &flag, sizeof(flag)); /*构造 client 地址 IP+端口 192.168.32.255+9000 */ bzero(&clientaddr, sizeof(clientaddr)); clientaddr.sin_family = AF_INET; inet_pton(AF_INET, BROADCAST_IP, &clientaddr.sin_addr.s_addr); clientaddr.sin_port = htons(CLIENT_PORT); int i = 0; while (1) { sprintf(buf, "itcast %d\n", i++); //fgets(buf, sizeof(buf), stdin); sendto(sockfd, buf, strlen(buf), 0, (struct sockaddr *)&clientaddr, sizeof(clientaddr)); sleep(1); } close(sockfd); return 0; }
组播
#include <stdio.h> #include <stdlib.h> #include <sys/types.h> #include <sys/socket.h> #include <string.h> #include <unistd.h> #include <arpa/inet.h> #include <net/if.h> #define SERVER_PORT 8000 #define CLIENT_PORT 9000 #define MAXLINE 1500 #define GROUP "239.0.0.2" int main(void) { int sockfd; struct sockaddr_in serveraddr, clientaddr; char buf[MAXLINE] = "xingwenpeng\n"; struct ip_mreqn group; /* 构造用于UDP通信的套接字 */ sockfd = socket(AF_INET, SOCK_DGRAM, 0); bzero(&serveraddr, sizeof(serveraddr)); serveraddr.sin_family = AF_INET; /* IPv4 */ serveraddr.sin_addr.s_addr = htonl(INADDR_ANY); /* 本地任意IP INADDR_ANY = 0 */ serveraddr.sin_port = htons(SERVER_PORT); bind(sockfd, (struct sockaddr *)&serveraddr, sizeof(serveraddr)); /*设置组地址*/ inet_pton(AF_INET, GROUP, &group.imr_multiaddr); /*本地任意IP*/ inet_pton(AF_INET, "0.0.0.0", &group.imr_address); /* eth0 --> 编号 * 命令:ip ad */ group.imr_ifindex = if_nametoindex("eth0"); setsockopt(sockfd, IPPROTO_IP, IP_MULTICAST_IF, &group, sizeof(group)); /*构造 client 地址 IP+端口 */ bzero(&clientaddr, sizeof(clientaddr)); clientaddr.sin_family = AF_INET; /* IPv4 239.0.0.2+9000 */ inet_pton(AF_INET, GROUP, &clientaddr.sin_addr.s_addr); clientaddr.sin_port = htons(CLIENT_PORT); int i = 0; while (1) { sprintf(buf, "itcast %d\n", i++); //fgets(buf, sizeof(buf), stdin); sendto(sockfd, buf, strlen(buf), 0, (struct sockaddr *)&clientaddr, sizeof(clientaddr)); sleep(1); } close(sockfd); return 0; }