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| -rwxr-xr-x | contrib/packet_utils.pm | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/contrib/packet_utils.pm b/contrib/packet_utils.pm new file mode 100755 index 00000000..cd1e830b --- /dev/null +++ b/contrib/packet_utils.pm @@ -0,0 +1,120 @@ +package packet_utils; + +# $Id$ + +# $Log$ +# Revision 1.1 2005/01/25 09:12:47 stanleyhopcroft +# packet creation and dumping hacks used by check_ica* and check_lotus +# +# Revision 1.1 2005-01-25 15:28:58+11 anwsmh +# Initial revision +# + +require Exporter; +@ISA = qw(Exporter); +@EXPORT_OK = qw(tethereal pdump); + +sub tethereal { + my ($tethereal_dump, $start_byte) = @_ ; + + # Return a string or array (depending on context) containing the characters from a tethereal trace. + # Skip all stuff until the first byte given by $start_byte in the first row .. + + &outahere("Invalid tethereal dump:", substr($tethereal_dump, 0, 71), 'fails to match m#\d\d\d\d \S\S(?: \S\S){1,15}#') + unless $tethereal_dump =~ m#\d\d\d\d \S\S(?: \S\S){1,15}# ; + + my @tethereal_dump = split(/\n/, $tethereal_dump) ; + my $first_line = shift @tethereal_dump ; + $first_line = unpack('x6 a48', $first_line) ; + # Take one extra space (after hex bytes) to use a template of 'a2 x' x 16 + # instead of 'a2 x' x 15 . 'a2' + my $last_line = pop @tethereal_dump ; + $last_line = unpack('x6 a48', $last_line) ; + + my $idx = index($first_line, $start_byte) ; + + &outahere(qq(Invalid tethereal dump: "$start_byte" not found in first line - "$first_line")) + if $idx == -1 ; + + $first_line = substr($first_line, $idx) ; + + my ($dump, @dump) = ('', ()) ; + + my $bytes = 0 ; + $bytes++ + while $first_line =~ m#\b\S\S#g ; + push @dump, unpack('a2x' x $bytes, $first_line) ; + + push @dump, unpack('x6 ' . 'a2x' x 16, $_) + foreach @tethereal_dump ; + + $bytes = 0 ; + $bytes++ + while $last_line =~ m#\b\S\S#g ; + + # Be more cautious with the last line; the ASCII decode may + # have been omitted. + + push @dump, unpack(('a2x' x ($bytes - 1)) . 'a2', $last_line) ; + + return wantarray ? map pack('H2', $_), @dump : pack('H2' x scalar @dump, @dump) ; + # return wantarray ? map hex($_), @dump : pack('H2' x scalar @dump, @dump) ; + +} + +sub pdump { + my ($x) = shift @_ ; + my (@bytes_in_row, $row, $dump) ; + + my $number_in_row = 16 ; + my $number_of_bytes = length $x ; + my $full_rows = int( $number_of_bytes / $number_in_row ) ; + my $bytes_in_last_row = $number_of_bytes % $number_in_row ; + my $template = "a$number_in_row " x $full_rows ; + my $nr = 0 ; + # Output format styled on tethereal. + foreach $row ( unpack($template, $x) ) { + @bytes_in_row = unpack('C*', $row) ; + $row =~ tr /\x00-\x1f\x80-\xff/./ ; + $dump .= join(' ', sprintf('%4.4x', $nr * 0x10), join(' ', map { sprintf "%2.2x", $_} @bytes_in_row), $row) ; + $dump .= "\n" ; + $nr++ ; + } + + if ( $bytes_in_last_row ) { + my $number_of_spaces = ($number_in_row - $bytes_in_last_row)*3 - 2 ; + + # 3 spaces (2 digts + 1 space) for each digit printed + # minus two spaces for those added by the join(' ',) below. + + $row = substr($x, -$bytes_in_last_row) ; + @bytes_in_row = unpack('C*', $row) ; + $row =~ tr /\x00-\x1f\x80-\xff/./ ; + # my $bytes = join(' ', map { sprintf "%2.2x", $_} @bytes_in_row) ; + # See comment below. + my $spaces = ' ' x $number_of_spaces ; + $dump .= join(' ', sprintf("%4.4x", $nr * 0x10 ), join(' ', map { sprintf "%2.2x", $_} @bytes_in_row), $spaces, $row) ; + $dump .= "\n" ; + } + + print STDERR $dump, "\n" ; + +=begin comment + +tsitc> perl -MBenchmark -e 'timethese(1_00_000, { printf => q<printf "%2.2x %2.2x %2.2x\n", 61, 62, 63>, sprintf => q<$x = sprintf "%2 +.2x %2.2x %2.2x\n", 61, 62, 63; print $x>} )' | perl -ne 'print if /intf/' + +Benchmark: timing 100000 iterations of printf, sprintf... + printf: 1 wallclock secs ( 0.55 usr + 0.00 sys = 0.55 CPU) + sprintf: 0 wallclock secs ( 0.11 usr + 0.00 sys = 0.11 CPU) + +so having sprintf in a loop seems more rational than a printf for the line ... + +=comment + +=cut + +} + + + |