3 # $Id: packet_utils.pm 1100 2005-01-25 09:12:47Z stanleyhopcroft $
5 # Revision 1.1 2005/01/25 09:12:47 stanleyhopcroft
6 # packet creation and dumping hacks used by check_ica* and check_lotus
8 # Revision 1.1 2005-01-25 15:28:58+11 anwsmh
14 @EXPORT_OK = qw(tethereal pdump);
17 my ($tethereal_dump, $start_byte) = @_ ;
19 # Return a string or array (depending on context) containing the characters from a tethereal trace.
20 # Skip all stuff until the first byte given by $start_byte in the first row ..
22 &outahere
("Invalid tethereal dump:", substr($tethereal_dump, 0, 71), 'fails to match m#\d\d\d\d \S\S(?: \S\S){1,15}#')
23 unless $tethereal_dump =~ m
#\d\d\d\d \S\S(?: \S\S){1,15}# ;
25 my @tethereal_dump = split(/\n/, $tethereal_dump) ;
26 my $first_line = shift @tethereal_dump ;
27 $first_line = unpack('x6 a48', $first_line) ;
28 # Take one extra space (after hex bytes) to use a template of 'a2 x' x 16
29 # instead of 'a2 x' x 15 . 'a2'
30 my $last_line = pop @tethereal_dump ;
31 $last_line = unpack('x6 a48', $last_line) ;
33 my $idx = index($first_line, $start_byte) ;
35 &outahere
(qq(Invalid tethereal
dump: "$start_byte" not found
in first line
- "$first_line"))
38 $first_line = substr($first_line, $idx) ;
40 my ($dump, @dump) = ('', ()) ;
44 while $first_line =~ m
#\b\S\S#g ;
45 push @dump, unpack('a2x' x
$bytes, $first_line) ;
47 push @dump, unpack('x6 ' . 'a2x' x
16, $_)
48 foreach @tethereal_dump ;
52 while $last_line =~ m
#\b\S\S#g ;
54 # Be more cautious with the last line; the ASCII decode may
57 push @dump, unpack(('a2x' x
($bytes - 1)) . 'a2', $last_line) ;
59 return wantarray ?
map pack('H2', $_), @dump : pack('H2' x
scalar @dump, @dump) ;
60 # return wantarray ? map hex($_), @dump : pack('H2' x scalar @dump, @dump) ;
66 my (@bytes_in_row, $row, $dump) ;
68 my $number_in_row = 16 ;
69 my $number_of_bytes = length $x ;
70 my $full_rows = int( $number_of_bytes / $number_in_row ) ;
71 my $bytes_in_last_row = $number_of_bytes % $number_in_row ;
72 my $template = "a$number_in_row " x
$full_rows ;
74 # Output format styled on tethereal.
75 foreach $row ( unpack($template, $x) ) {
76 @bytes_in_row = unpack('C*', $row) ;
77 $row =~ tr
/\x00-\x1f\x80-\xff/./ ;
78 $dump .= join(' ', sprintf('%4.4x', $nr * 0x10), join(' ', map { sprintf "%2.2x", $_} @bytes_in_row), $row) ;
83 if ( $bytes_in_last_row ) {
84 my $number_of_spaces = ($number_in_row - $bytes_in_last_row)*3 - 2 ;
86 # 3 spaces (2 digts + 1 space) for each digit printed
87 # minus two spaces for those added by the join(' ',) below.
89 $row = substr($x, -$bytes_in_last_row) ;
90 @bytes_in_row = unpack('C*', $row) ;
91 $row =~ tr
/\x00-\x1f\x80-\xff/./ ;
92 # my $bytes = join(' ', map { sprintf "%2.2x", $_} @bytes_in_row) ;
94 my $spaces = ' ' x
$number_of_spaces ;
95 $dump .= join(' ', sprintf("%4.4x", $nr * 0x10 ), join(' ', map { sprintf "%2.2x", $_} @bytes_in_row), $spaces, $row) ;
99 print STDERR
$dump, "\n" ;
103 tsitc> perl -MBenchmark -e 'timethese(1_00_000, { printf => q<printf "%2.2x %2.2x %2.2x\n", 61, 62, 63>, sprintf => q<$x = sprintf "%2
104 .2x %2.2x %2.2x\n", 61, 62, 63; print $x>} )' | perl -ne 'print if /intf/'
106 Benchmark: timing 100000 iterations of printf, sprintf...
107 printf: 1 wallclock secs ( 0.55 usr + 0.00 sys = 0.55 CPU)
108 sprintf: 0 wallclock secs ( 0.11 usr + 0.00 sys = 0.11 CPU)
110 so having sprintf in a loop seems more rational than a printf for the line ...