| Current Path : /usr/src/contrib/ipfilter/test/ |
FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
| Current File : //usr/src/contrib/ipfilter/test/vfycksum.pl |
#
# validate the IPv4 header checksum.
# $bytes[] is an array of 16bit values, with $cnt elements in the array.
#
sub dump {
print "\n";
for ($i = 0; $i < $#bytes; $i++) {
printf "%04x ", $bytes[$i];
}
print "\n";
}
sub dosum {
local($seed) = $_[0];
local($start) = $_[1];
local($max) = $_[2];
local($idx) = $start;
local($lsum) = $seed;
for ($idx = $start, $lsum = $seed; $idx < $max; $idx++) {
$lsum += $bytes[$idx];
}
$lsum = ($lsum & 0xffff) + ($lsum >> 16);
$lsum = ~$lsum & 0xffff;
return $lsum;
}
sub ipv4check {
local($base) = $_[0];
$hl = $bytes[$base] / 256;
return if (($hl >> 4) != 4); # IPv4 ?
$hl &= 0xf;
$hl <<= 1; # get the header length in 16bit words
$hs = &dosum(0, $base, $base + $hl);
$osum = $bytes[$base + 5];
if ($hs != 0) {
$bytes[$base + 5] = 0;
$hs2 = &dosum(0, $base, $base + $hl);
$bytes[$base + 5] = $osum;
printf " IP: ($hl,%x) %x != %x", $hs, $osum, $hs2;
} else {
print " IP($base): ok ";
}
#
# Recognise TCP & UDP and calculate checksums for each of these.
#
if (($bytes[$base + 4] & 0xff) == 6) {
&tcpcheck($base);
}
if (($bytes[$base + 4] & 0xff) == 17) {
&udpcheck($base);
}
if (($bytes[$base + 4] & 0xff) == 1) {
&icmpcheck($base);
}
if ($base == 0) {
print "\n";
}
}
sub tcpcheck {
local($base) = $_[0];
local($hl) = $bytes[$base] / 256;
return if (($hl >> 4) != 4);
return if ($bytes[$base + 3] & 0x1fff);
$hl &= 0xf;
$hl <<= 1;
local($hs2);
local($hs) = 6; # TCP
local($len) = $bytes[$base + 1] - ($hl << 1);
$hs += $len;
$hs += $bytes[$base + 6]; # source address
$hs += $bytes[$base + 7];
$hs += $bytes[$base + 8]; # destination address
$hs += $bytes[$base + 9];
local($tcpsum) = $hs;
local($thl) = $bytes[$base + $hl + 6] >> 8;
$thl &= 0xf0;
$thl >>= 2;
$x = $bytes[$base + 1];
$y = ($cnt - $base) * 2;
$z = 0;
if ($bytes[$base + 1] > ($cnt - $base) * 2) {
print "[cnt=$cnt base=$base]";
$x = $bytes[$base + 1];
$y = ($cnt - $base) * 2;
$z = 1;
} elsif (($cnt - $base) * 2 < $hl + 20) {
$x = ($cnt - $base) * 2;
$y = $hl + 20;
$z = 2;
} elsif (($cnt - $base) * 2 < $hl + $thl) {
$x = ($cnt - $base) * 2;
$y = $hl + $thl;
$z = 3;
} elsif ($len < $thl) {
$x = ($cnt - $base) * 2;
$y = $len;
$z = 4;
}
if ($z) {
print " TCP: missing data($x $y $z) $hl";
# &dump();
return;
}
local($tcpat) = $base + $hl;
$hs = &dosum($tcpsum, $tcpat, $cnt);
if ($hs != 0) {
local($osum) = $bytes[$tcpat + 8];
$bytes[$base + $hl + 8] = 0;
$hs2 = &dosum($tcpsum, $tcpat, $cnt);
$bytes[$tcpat + 8] = $osum;
printf " TCP: (%x) %x != %x", $hs, $osum, $hs2;
} else {
print " TCP: ok ($x $y)";
}
}
sub udpcheck {
local($base) = $_[0];
local($hl) = $bytes[0] / 256;
return if (($hl >> 4) != 4);
return if ($bytes[3] & 0x1fff);
$hl &= 0xf;
$hl <<= 1;
local($hs2);
local($hs) = 17; # UDP
local($len) = $bytes[$base + 1] - ($hl << 1);
$hs += $len;
$hs += $bytes[$base + 6]; # source address
$hs += $bytes[$base + 7];
$hs += $bytes[$base + 8]; # destination address
$hs += $bytes[$base + 9];
local($udpsum) = $hs;
if ($bytes[$base + 1] > ($cnt - $base) * 2) {
print " UDP: missing data(1)";
return;
} elsif ($bytes[$base + 1] < ($hl << 1) + 8) {
print " UDP: missing data(2)";
return;
} elsif (($cnt - $base) * 2 < ($hl << 1) + 8) {
print " UDP: missing data(3)";
return;
}
local($udpat) = $base + $hl;
$hs = &dosum($udpsum, $udpat, $cnt);
local($osum) = $bytes[$udpat + 3];
#
# It is valid for UDP packets to have a 0 checksum field.
# If it is 0, then display what it would otherwise be.
#
if ($osum == 0) {
printf " UDP: => %x", $hs;
} elsif ($hs != 0) {
$bytes[$udpat + 3] = 0;
$hs2 = &dosum($udpsum, $udpat, $cnt);
$bytes[$udpat + 3] = $osum;
printf " UDP: (%x) %x != %x", $hs, $osum, $hs2;
} else {
print " UDP: ok";
}
}
sub icmpcheck {
local($base) = $_[0];
local($hl) = $bytes[$base + 0] / 256;
return if (($hl >> 4) != 4);
return if ($bytes[3] & 0x1fff);
$hl &= 0xf;
$hl <<= 1;
local($hs);
local($hs2);
local($len) = $bytes[$base + 1] - ($hl << 1);
if ($bytes[$base + 1] > ($cnt - $base) * 2) {
print " ICMP: missing data(1)";
return;
} elsif ($bytes[$base + 1] < ($hl << 1) + 8) {
print " ICMP: missing data(2)";
return;
} elsif (($cnt - $base) * 2 < ($hl << 1) + 8) {
print " ICMP: missing data(3)";
return;
}
local($osum) = $bytes[$base + $hl + 1];
$bytes[$base + $hl + 1] = 0;
$hs2 = &dosum(0, $base + $hl, $cnt);
$bytes[$base + $hl + 1] = $osum;
if ($osum != $hs2) {
printf " ICMP: (%x) %x != %x", $hs, $osum, $hs2;
} else {
print " ICMP: ok";
}
if ($base == 0) {
$type = $bytes[$hl] >> 8;
if ($type == 3 || $type == 4 || $type == 5 ||
$type == 11 || $type == 12) {
&ipv4check($hl + 4);
}
}
}
while ($#ARGV >= 0) {
open(I, "$ARGV[0]") || die $!;
print "--- $ARGV[0] ---\n";
$multi = 0;
while (<I>) {
chop;
s/#.*//g;
#
# If the first non-comment, non-empty line of input starts
# with a '[', then allow the input to be a multi-line hex
# string, otherwise it has to be all on one line.
#
if (/^\[/) {
$multi=1;
s/^\[[^]]*\]//g;
}
s/^ *//g;
if (length == 0) {
next if ($cnt == 0);
&ipv4check(0);
$cnt = 0;
$multi = 0;
next;
}
#
# look for 16 bits, represented with leading 0's as required,
# in hex.
#
s/\t/ /g;
while (/^[0-9a-fA-F][0-9a-fA-F] [0-9a-fA-F][0-9a-fA-F] .*/) {
s/^([0-9a-fA-F][0-9a-fA-F]) ([0-9a-fA-F][0-9a-fA-F]) (.*)/$1$2 $3/;
}
while (/.* [0-9a-fA-F][0-9a-fA-F] [0-9a-fA-F][0-9a-fA-F] .*/) {
$b=$_;
s/(.*?) ([0-9a-fA-F][0-9a-fA-F]) ([0-9a-fA-F][0-9a-fA-F]) (.*)/$1 $2$3 $4/g;
}
if (/.* [0-9a-fA-F][0-9a-fA-F] [0-9a-fA-F][0-9a-fA-F]/) {
$b=$_;
s/(.*?) ([0-9a-fA-F][0-9a-fA-F]) ([0-9a-fA-F][0-9a-fA-F])/$1 $2$3/g;
}
while (/^[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F].*/) {
$x = $_;
$x =~ s/([0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]).*/$1/;
$x =~ s/ *//g;
$y = hex $x;
s/[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F] *(.*)/$1/;
$bytes[$cnt] = $y;
#print "bytes[$cnt] = $x\n";
$cnt++;
}
#
# Pick up stragler bytes.
#
if (/^[0-9a-fA-F][0-9a-fA-F]/) {
$y = hex $_;
$bytes[$cnt++] = $y * 256;
}
if ($multi == 0 && $cnt > 0) {
&ipv4check(0);
$cnt = 0;
}
}
if ($cnt > 0) {
&ipv4check(0);
}
close(I);
shift(@ARGV);
}