capturing bridge config packets

[Nelson]

hi,

i configured and enabled bridging on host A (kernel 2.2.14). Every sec,
the bridge will transmit a config packet thru' eth0 (only 1 interface).

i run the code (attached) on host B (kernel 2.2.14). it is suppose to
read all sort of packets coming from all the interfaces of host B. host A
and B are connect directly using a cross-cable. however, the code could
not capture the config packets from the bridge, although it could capture
ping packets from host A. however, if i run tcpdump on another window in
host B, the code now is able to capture the bridge config packets as well!

i would like the code to be able to capture the bridge config packets
without the need to run tcpdump. did i miss out something in the code?

thanx.

Nelson
-------------------------------------------
"You will never walk alone"

#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <linux/if_packet.h>
#include <linux/supplicant.h>
#include<linux/if_ether.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <linux/sockios.h>
#include <arpa/inet.h>
#include <errno.h>

unsigned char buf[10002]={128};   

void print_head (void)
{
  printf("HW-ADDR: %.2x:%.2x:%.2x:%.2x:%.2x:%.2x -----> %.2x:%.2x:%.2x:%.2x:%.2x:%.2x 
\n",
  buf[6],buf[7],buf[8],buf[9],buf[10],buf[11],
  buf[0],buf[1],buf[2],buf[3],buf[4],buf[5]);
}

main(int argc, char **argv)
{
  int sockid;
  int counter = 0;

  if ( (sockid = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL)) ) < 0)
  {
        printf("%s: socket failed: %d\n", argv[0], errno);
        exit(-1);
    } else printf("sock is %d\n",sockid);


  for(;;)
  {
        printf("i'm waiting...\n");
        recv(sockid,buf,10000,0);
        printf("message %d: ", counter);
        print_head();
        counter++;
        printf("\n\n"); 
  }

  close(sockid);
}