#! /bin/perl

open LEFT, "+</dev/unet0" or die "open /dev/unet0: $!";
open RIGHT, "+</dev/unet1" or die "open /dev/unet1: $!";

$rd = 0;
vec($rd, fileno(LEFT), 1) = 1;
vec($rd, fileno(RIGHT), 1) = 1;

for (;;) {
  select($ord = $rd, undef, undef, undef);
  if (vec($ord, fileno(LEFT), 1)) {
    defined sysread(LEFT, $buf, 65536) or die "read(/dev/unet0): $!";
    print "read packet from unet0\n";
    hexdump($buf);
    syswrite(RIGHT, $buf, length($buf));
  }
  if (vec($ord, fileno(RIGHT), 1)) {
    defined sysread(RIGHT, $buf, 65536) or die "read(/dev/unet1): $!";
    print "read packet from unet1\n";
    hexdump($buf);
    syswrite(LEFT, $buf, length($buf));
  }
}

sub hexdump {
  my $buf = shift;
  my ($off, $i);

  while ($off < length($buf)) {
    printf "%08x : ", $off;
    for ($i = $off; $i < $off + 16; $i++) {
      if ($i >= length($buf)) {
	print "** ";
      } else {
	printf "%02x ", ord(substr($buf, $i, 1));
      }
    }
    print ": ";
    for ($i = $off; $i < $off + 16; $i++) {
      if ($i >= length($buf)) {
	print "*";
      } else {
	$ch = substr($buf, $i, 1);
	$code = ord($ch);
	if ($code < 32 || $code > 126) {
	  print ".";
	} else {
	  print $ch;
	}
      }
    }
    print "\n";
    $off += 16;
  }
  print "\n";
}