FLIPS and UDP broadcast

[Tiago Jorge]

hello again to you all...

i'm trying to broadcast through a LAN using the socket interface 
provided by FLIPS with a small test program, here is the code:

##################################################

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>   
#include <string.h>
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>

#include <l4/log/l4log.h>

#define PORTNUMBER 5824

/*Sets the socket to non-blocking*/

void unblock_socket(int sd);
void unblock_socket(int sd)
{
  int flags;

  /* get current socket flags */
  if ((flags=fcntl(sd, F_GETFL)) == -1)
    {
      LOG("GETFL");
      exit(1);
    }

  /* set socket to non-blocking */
  flags |= O_NDELAY;
  if (fcntl(sd, F_SETFL, flags) == -1)
    {
      LOG("SETFL");
      exit(1);
    }
}

int main (int argc, char** argv)
{
  int socketDesc;    /* Socket Descriptor */
  int addrLength;
  int i;
  struct sockaddr_in destinationAddr,
                     myAddr,
                     responseAddr;
  struct hostent *hostNameBufPtr;
  char outMessageBuf[128];
  char inMessageBuf[128];
  int trueFlag = 0x1;
  int size_sent = 0;
  int recvfrom_error;

  /* Create socket from which to send */
  if ((socketDesc = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
      LOG("open error on socket");
      exit(1);
  }

  /* BIND the socket on our end to any available port (i.e.
     leave it up to the system to assign a port (used for
     replys */
  myAddr.sin_family = AF_INET;
  myAddr.sin_addr.s_addr = htonl(INADDR_ANY);
  myAddr.sin_port = htons(PORTNUMBER);    /* The zero says bind to any 
port */
 
  if (bind(socketDesc, (struct sockaddr *) &myAddr, sizeof(myAddr))
      < 0) {
      perror("bind error");
      exit(1);
  }
 
  /* And build BROADCAST address */
  destinationAddr.sin_family = AF_INET;
  destinationAddr.sin_addr.s_addr = htonl(INADDR_BROADCAST);
  destinationAddr.sin_port = htons(PORTNUMBER);

  /* Set the socket to permit multicasts on the local LAN */
  if (setsockopt(socketDesc, SOL_SOCKET, SO_BROADCAST, &trueFlag,
                 sizeof(trueFlag)) != 0) {
      LOG("setsockopt error");
      exit(1);
  }
 
  //COMMENTED
  //unblock_socket(socketDesc);
 
   
  for(i=0; i<2; i++){
    /* Broadcast message */
    sprintf(outMessageBuf,"%d", i);
    if ((size_sent = sendto(socketDesc, outMessageBuf, 
strlen(outMessageBuf)+1, 0,
       (struct sockaddr *)&destinationAddr, sizeof(destinationAddr))) < 0) {
       LOG("socket send error");
       exit(1);
    }
  }
  LOG("size sent: %d\n", size_sent);
 
  return 0;
}

##################################################

i've tried out the mini_http example with mini_ifconfig and works out 
fine with this menu.lst:

title           Testes
root            (hd0,0)
kernel          /home/tiago/fiasco_builddir/rmgr -sigma0
modaddr         0x02000000
module          /home/tiago/fiasco_builddir/main -nokdb -nowait 
-serial_esc -comspeed 115200 -comport 1
module          /home/tiago/fiasco_builddir/sigma0
module          /home/tiago/fiasco_builddir/names
module          /home/tiago/fiasco_builddir/dm_phys
module          /home/tiago/fiasco_builddir/l4io
module          /home/tiago/fiasco_builddir/name_server
module          /home/tiago/fiasco_builddir/flips-lxdrv
module          /home/tiago/fiasco_builddir/mini_ifconfig eth0 
10.10.5.197 255.255.0.0
module         /home/tiago/fiasco_builddir/mini_http

but when i add my program, replacing mini_http, built with the same libs 
and configs as mini_http, gives me an error when sends the packet.

LOG("socket send error");

am i doing this right? does flips support broadcast UDP? i've hacked 
mini_ifconfig and i see that the eth0 flags are ok for broadcasting... 
what am i doing wrong?

thanks in advance

Tiago