Attachment 305204 Details for Bug 369591 – multicast receiver that can bind to specific interface

multicast receiver that can bind to specific interface

mcreceive.c (text/x-csrc), 4.03 KB, created by Aleksandar Kostadinov on 2008-05-13 06:51:34 UTC

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Filename:

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Creator: Aleksandar Kostadinov

Created: 2008-05-13 06:51:34 UTC

Size: 4.03 KB

patch

obsolete

>#include <sys/types.h>  /* for type definitions */
>#include <sys/socket.h> /* for socket API calls */
>#include <netinet/in.h> /* for address structs */
>#include <arpa/inet.h>  /* for sockaddr_in */
>#include <stdio.h>      /* for printf() and fprintf() */
>#include <stdlib.h>     /* for atoi() */
>#include <string.h>     /* for strlen() */
>#include <unistd.h>     /* for close() */
>
>#define MAX_LEN  1024   /* maximum receive string size */
>#define MIN_PORT 1024   /* minimum port allowed */
>#define MAX_PORT 65535  /* maximum port allowed */
>
>int main(int argc, char *argv[]) {
>
>  int sock;                     /* socket descriptor */
>  int flag_on = 1;              /* socket option flag */
>  struct sockaddr_in mc_addr;   /* socket address structure */
>  char recv_str[MAX_LEN+1];     /* buffer to receive string */
>  int recv_len;                 /* length of string received */
>  struct ip_mreq mc_req;        /* multicast request structure */
>  char* mc_addr_str;            /* multicast IP address */
>  struct in_addr if_addr;       /* IP Address Structure */
>  char* if_addr_str;            /* bind interface address */
>  unsigned short mc_port;       /* multicast port */
>  struct sockaddr_in from_addr; /* packet source */
>  unsigned int from_len;        /* source addr length */
>
>  /* validate number of arguments */
>  if (argc != 4) {
>    fprintf(stderr, 
>            "Usage: %s <Multicast IP> <Multicast Port> <Bind Interface Addr>\n", 
>            argv[0]);
>    exit(1);
>  }
>
>  mc_addr_str = argv[1];      /* arg 1: multicast ip address */
>  mc_port = atoi(argv[2]);    /* arg 2: multicast port number */
>  if_addr_str = argv[3];      /* arg 3: bind interface ip address */
>
>  /* validate the port range */
>  if ((mc_port < MIN_PORT) || (mc_port > MAX_PORT)) {
>    fprintf(stderr, "Invalid port number argument %d.\n",
>            mc_port);
>    fprintf(stderr, "Valid range is between %d and %d.\n",
>            MIN_PORT, MAX_PORT);
>    exit(1);
>  }
>
>  /* create socket to join multicast group on */
>  if ((sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
>    perror("socket() failed");
>    exit(1);
>  }
>  
>  /* set reuse port to on to allow multiple binds per host */
>  if ((setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &flag_on,
>       sizeof(flag_on))) < 0) {
>    perror("setsockopt() failed");
>    exit(1);
>  }
>
>  /* network interface */
>  inet_aton(if_addr_str,&if_addr);
>
>  /* construct an IGMP join request structure */
>  mc_req.imr_multiaddr.s_addr = inet_addr(mc_addr_str);
>  mc_req.imr_interface.s_addr = if_addr.s_addr; /* JOIN on the specified interface - not htonl(INADDR_ANY); */
>
>  /* construct a multicast address structure */
>  memset(&mc_addr, 0, sizeof(mc_addr));
>  mc_addr.sin_family      = AF_INET;
>  mc_addr.sin_addr.s_addr = mc_req.imr_multiaddr.s_addr; /* Bind to the specific mcast address - not allowed on windows */ /* htonl(INADDR_ANY); */
>  mc_addr.sin_port        = htons(mc_port);
>
>  /* bind to multicast address to socket */
>  if ((bind(sock, (struct sockaddr *) &mc_addr, 
>       sizeof(mc_addr))) < 0) {
>    perror("bind() failed");
>    exit(1);
>  }
>
>  /* send an ADD MEMBERSHIP message via setsockopt */
>  if ((setsockopt(sock, IPPROTO_IP, IP_ADD_MEMBERSHIP, 
>       (void*) &mc_req, sizeof(mc_req))) < 0) {
>    perror("setsockopt() failed");
>    exit(1);
>  }
>
>  for (;;) {          /* loop forever */
>
>    /* clear the receive buffers & structs */
>    memset(recv_str, 0, sizeof(recv_str));
>    from_len = sizeof(from_addr);
>    memset(&from_addr, 0, from_len);
>
>    /* block waiting to receive a packet */
>    if ((recv_len = recvfrom(sock, recv_str, MAX_LEN, 0, 
>         (struct sockaddr*)&from_addr, &from_len)) < 0) {
>      perror("recvfrom() failed");
>      exit(1);
>    }
>
>    /* output received string */
>    printf("Received %d bytes from %s: ", recv_len, 
>           inet_ntoa(from_addr.sin_addr));
>    printf("%s", recv_str);
>  }
>
>  /* send a DROP MEMBERSHIP message via setsockopt */
>  if ((setsockopt(sock, IPPROTO_IP, IP_DROP_MEMBERSHIP, 
>       (void*) &mc_req, sizeof(mc_req))) < 0) {
>    perror("setsockopt() failed");
>    exit(1);
>  }
>
>  close(sock);  
>}

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Attachments on bug 369591: 250061 | 305204 | 305466