Net::Tshark had what amounts to a single release two years ago and has no tests. That makes it hard to tell how reliable that module is.

not sure it's correct way to get mss options

Have you tried looking at the data structure with Data::Dumper?

map {$_ ->{mss}->{1500} } ...

Without knowing the data structure, I'm going to wager a guess that maybe you need to do something like grep { $_->...->{mss}==1500 } @packets, where ... depends on the data structure you see with Data::Dumper.

However, I'm still not sure why you're not simply doing something like this, where you are free to customize the display filter and output format without some module in between:

my @cmd = ('tshark','-r',$PCAPFILE,
    qw# -R tcp.options.mss -T fields -e ip.src -e tcp.srcport
    -e ip.dst -e tcp.dstport -e tcp.options.mss_val #);
open my $ts, '-|', @cmd or die "Error opening pipe: $!";
while(<$ts>) {
    chomp;
    my ($src_addr,$src_port,$dst_addr,$dst_port,$mss) = split /\t/;
    print "$src_addr:$src_port -> $dst_addr:$dst_port  MSS=$mss\n";
}
close $ts or die $! ? "Error closing pipe: $!"
    : "Exit status \$?=$? from pipe";

[download]

(Or, look at IPC::Run to execute tshark, which is all that Net::Tshark is doing anyway.)

In reply to Re^3: filter tcpdump packets by Anonymous Monk
in thread filter tcpdump packets by syboar

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.