package packet_utils; # $Id: packet_utils.pm,v 1.1 2005/01/25 09:12:47 stanleyhopcroft Exp $ # $Log: packet_utils.pm,v $ # 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 $dump, "\n" ; =begin comment tsitc> perl -MBenchmark -e 'timethese(1_00_000, { printf => q, sprintf => q<$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 }