www.pudn.com > vxworks_networking.rar > broadcastSend.c

/* broadcastsend.c - Demo for sending a broadcast  message */
 
 /*
 modification history
 --------------------
  
 01f,25nov97,rv   added return TRUE 
 01e,22sep97,mm   defined  broadcastSend(int port)
 01d,22sep97,mm   cast arg 4 of setsockopt function
 01c,22sep97,mm   cast arg 5 of sendto function
 01b,22sep97,mm   added include     
 01a,08feb94,ms   cleaned and modified for VxDemo.
 */
 
 #include 
 #include 
 #include 
 #include 
 #include "vxWorks.h"
 #include "socket.h"
 #include "sockLib.h"
 #include "in.h"
 #include 
 
 #define BROADCAST_ADDR "147.11.184.255" /* your subnet network's broadcast 
                                           * inet address
                                           */
 
 LOCAL char buf[] = "Hello, world!!!\n";  /* broadcast message */
 
 /*****************************************************************************
  * broadcastSend - Sends broadcasting message 
  *
  * DESCRIPTION
  *
  *     Demo for sending broadcasting message.
  *
  * RETURNS: OK or ERROR
  *
  * CONFIGURATION:
  *
  * You need to set/change the value of the BROADCAST_ADDR constant to 
  * your (subnet) network's broadcast inet address.
  *
  * EXAMPLE:
  *
  *     Run broadcastSend task on one VxWorks system as follows
  *     after starting the broadcastGet task from another VxWorks system
  *     in the same physical network. The other half of the demonstration
  *     is in broadcastGet.c.
  *
  *     -> sp (broadcastSend,  7001)
  *
  *     where 7001 (port number should be greater than 5000 for user-developed)
  *     is an example port number used in this demonstration to send the
  *     broadcast message.
  *
  */
 
 STATUS broadcastSend(int port);
 
 STATUS broadcastSend 
     (
     int port                             /* port number */
     )
 
     {
     int sockFd;                          /* socket fd */
     struct sockaddr_in sendToAddr;       /* receiver's addresss */
     int   sendNum ;
     int   on;
 
 
     /* Open UDP socket */
     sockFd = socket(AF_INET, SOCK_DGRAM, 0);
     if (sockFd == ERROR)
    	{ 
 	perror ("socket not opened ");
 	return (ERROR);
 	}
 
 
     /* Use the SO_BROADCAST option when an application needs to broadcast data
      */ 
  
     on = 1; /* turn ON SO_BROADCAST option*/
     if (setsockopt (sockFd, SOL_SOCKET, SO_BROADCAST, (char *) &on, sizeof(int))  == 
                      ERROR)
 	{
 	perror ("setsockopt failed ");
 	return (ERROR);
 	}
 
     /* zero out the sockaddr_in structures and setup receivers' address */ 
     bzero ((char *) &sendToAddr, sizeof (struct sockaddr_in));
     sendToAddr.sin_family = AF_INET;
     sendToAddr.sin_port = htons (port);
     sendToAddr.sin_addr.s_addr = inet_addr (BROADCAST_ADDR);
 
     /* send the broadcast message to other systems in the same network */
     if ((sendNum = sendto (sockFd, buf, sizeof (buf), 0, (struct sockaddr  *) &sendToAddr, 
 	sizeof (struct sockaddr_in))) == ERROR)
     	{
     	perror ("sendto broadcast failed ");
        	return (ERROR);
 	}
 
     printf ("%d bytes of broadcast message sent: %s\n", sendNum,
 	            buf);
     close (sockFd);
     return(TRUE);
     }