Linux Multicast implementation

Server

#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;    /* construct socket for UDP communication */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);    /* Local any IP inaddr_any = 0 */serveraddr.sin_port = htons (Server_port);    Bind (SOCKFD, (struct sockaddr *) &serveraddr, sizeof (SERVERADDR));    /* Set the group address */Inet_pton (af_inet, Group, &AMP;GROUP.IMR_MULTIADDR);    /* Local arbitrary ip*/Inet_pton (af_inet, "0.0.0.0", &group.imr_address); /* eth0--Number * command: IP ad */Group.imr_ifindex = If_nametoindex ("eth0");    SetSockOpt (SOCKFD, Ipproto_ip, ip_multicast_if, &group, sizeof (group));    /* Construct client Address ip+ port */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;}

Client:

#include <netinet/in.h> #include <stdio.h> #include <sys/types.h> #include <sys/socket.h># Include <arpa/inet.h> #include <string.h> #include <stdlib.h> #include <sys/stat.h> #include <unistd.h> #include <fcntl.h> #include <net/if.h> #define SERVER_PORT 8000#define MAXLINE 4096#define    Client_port 9000#define GROUP "239.0.0.2" int main (int argc, char *argv[]) {struct sockaddr_in serveraddr, localaddr;    int CONFD;    ssize_t Len;    Char Buf[maxline];    /* Multicast struct */struct IP_MREQN group;    1. Create a socket CONFD = socket (af_inet, SOCK_DGRAM, 0);    2. Initialize the local-side address bzero (&localaddr, sizeof (LOCALADDR));    localaddr.sin_family = af_inet;    Inet_pton (Af_inet, "0.0.0.0", &localaddr.sin_addr.s_addr);    Localaddr.sin_port = htons (Client_port);    Bind (CONFD, (struct sockaddr *) &localaddr, sizeof (LOCALADDR));    /* Set the group address */Inet_pton (af_inet, Group, &AMP;GROUP.IMR_MULTIADDR); /* Local any ip*/Inet_pton (Af_inet, "0.0.0.0 ", &group.imr_address);    /* eth0--number//command: IP ad */group.imr_ifindex = If_nametoindex ("eth0");    /* Set the client to join the multicast group */setsockopt (CONFD, Ipproto_ip, ip_add_membership, &group, sizeof (group));        while (1) {len = Recvfrom (CONFD, buf, sizeof (BUF), 0, NULL, 0);    Write (Stdout_fileno, buf, Len);    } close (CONFD); return 0;}

　　

Linux Multicast implementation