Attachment 305466 Details for Bug 369591 – modified mcsend to set IP_MULTICAST_IF

modified mcsend to set IP_MULTICAST_IF

mcsend.c (text/plain), 3.13 KB, created by Neil Horman on 2008-05-15 11:09:21 UTC

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Creator: Neil Horman

Created: 2008-05-15 11:09:21 UTC

Size: 3.13 KB

patch

obsolete

>#include <sys/types.h>   /* for type definitions */
>#include <sys/socket.h>  /* for socket API function calls */
>#include <netinet/in.h>  /* for address structs */
>#include <arpa/inet.h>   /* for sockaddr_in */
>#include <stdio.h>       /* for printf() */
>#include <stdlib.h>      /* for atoi() */
>#include <string.h>      /* for strlen() */
>#include <unistd.h>      /* for close() */
>
>#define MAX_LEN  1024    /* maximum string size to send */
>#define MIN_PORT 1024    /* minimum port allowed */
>#define MAX_PORT 65535   /* maximum port allowed */
>
>int main(int argc, char *argv[]) {
>
>  int sock;                   /* socket descriptor */
>  char send_str[MAX_LEN];     /* string to send */
>  struct sockaddr_in mc_addr; /* socket address structure */
>  unsigned int send_len;      /* length of string to send */
>  char* mc_addr_str;          /* multicast IP address */
>  char* src_addr_str;          /* multicast IP address */
>  struct ip_mreqn opt;
>  unsigned int mc_port;     /* multicast port */
>  unsigned char mc_ttl=1;     /* time to live (hop count) */
>
>  /* validate number of arguments */
>  if (argc != 4) {
>    fprintf(stderr, 
>            "Usage: %s <Multicast IP> <Multicast Port> <SRc address>\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 */
>  src_addr_str = argv[3];      /* arg 3: local port to send the frame from */
>
>  /* 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 a socket for sending to the multicast address */
>  if ((sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
>    perror("socket() failed");
>    exit(1);
>  }
>  
>  /* set the TTL (time to live/hop count) for the send */
>  if ((setsockopt(sock, IPPROTO_IP, IP_MULTICAST_TTL, 
>       (void*) &mc_ttl, sizeof(mc_ttl))) < 0) {
>    perror("setsockopt() failed");
>    exit(1);
>  } 
>
>  opt.imr_multiaddr.s_addr = inet_addr(mc_addr_str);
>  opt.imr_address.s_addr = inet_addr(src_addr_str);
>  opt.imr_ifindex = 0;
>
>  if (setsockopt(sock, IPPROTO_IP, IP_MULTICAST_IF, (void *)&opt, sizeof(struct ip_mreqn)) <0) {
>	perror("Could not set IP_MULTICAST_IF failed");
>	exit(1);
>  }
>  
>  /* construct a multicast address structure */
>  memset(&mc_addr, 0, sizeof(mc_addr));
>  mc_addr.sin_family      = AF_INET;
>  mc_addr.sin_addr.s_addr = inet_addr(mc_addr_str);
>  mc_addr.sin_port        = htons(mc_port);
>
>  printf("Begin typing (return to send, ctrl-C to quit):\n");
>
>  /* clear send buffer */
>  memset(send_str, 0, sizeof(send_str));
>
>  while (fgets(send_str, MAX_LEN, stdin)) {
>    send_len = strlen(send_str);
>
>    /* send string to multicast address */
>    if ((sendto(sock, send_str, send_len, 0, 
>         (struct sockaddr *) &mc_addr, 
>         sizeof(mc_addr))) != send_len) {
>      perror("sendto() sent incorrect number of bytes");
>      exit(1);
>    }
>
>    /* clear send buffer */
>    memset(send_str, 0, sizeof(send_str));
>  }
>
>  close(sock);  
>
>  exit(0);
>}
>

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Attachments on bug 369591: 250061 | 305204 | 305466