#!/usr/bin/env perl

# Copyright (c) 2025, R. W. Rodolico
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# 1. Redistributions of source code must retain the above copyright notice, this
#    list of conditions and the following disclaimer.
#
# 2. Redistributions in binary form must reproduce the above copyright notice,
#    this list of conditions and the following disclaimer in the documentation
#    and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
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# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

# linux_network
# Linux network interfaces and addresses from ip.
#
# Revision History:
# 2026-10-18 Claude v1.0.0 new sensor, split from unix_network (bug 210)

package linux_network;

use strict;
use warnings;
use version;
our $VERSION = version->declare('v1.0.0');

use FindBin;
use File::Spec;
use lib File::Spec->catdir($FindBin::Bin), File::Spec->catdir("$FindBin::Bin/..");
use library qw(:all);

my $CATEGORY = 'network';
#######################################################
#
# parseLinuxNetwork( $ipLinkText, $ipAddrText )
#
# Parses Linux ip command output into old network key paths.
#
# Parameters:
#   $ipLinkText - text from ip -o link
#   $ipAddrText - text from ip -o addr
#
# Returns:
#   array reference of output lines
#
# Side Effects:
#   none
#
#######################################################
sub parseLinuxNetwork {
   my ($ipLinkText, $ipAddrText) = @_;
   my @out;

   my %seen;
   if (defined($ipLinkText)) {
      foreach my $line (split(/\n/, $ipLinkText)) {
         next unless $line =~ /^\d+:\s+([^:]+):/;
         my $if = $1;
         next if $if eq 'lo';
         $seen{$if} = 1;

         if ($line =~ /mtu\s+(\d+)/) {
            push @out, "$CATEGORY\t$if\tmtu\t$1";
         }
         if ($line =~ /link\/\S+\s+([0-9a-f:]{17})/i) {
            push @out, "$CATEGORY\t$if\tmac\t" . lc($1);
         }
      }
   }

   if (defined($ipAddrText)) {
      foreach my $line (split(/\n/, $ipAddrText)) {
         next unless $line =~ /^\d+:\s+([^\s]+)\s+/;
         my $if = $1;
         next if $if eq 'lo';
         next unless $seen{$if} || $line =~ /\s+inet/ || $line =~ /\s+inet6/;

         if ($line =~ /\sinet\s+([0-9.]+)\/(\d+)/) {
            push @out, "$CATEGORY\t$if\taddress\t$1";
            push @out, "$CATEGORY\t$if\tnetmask\t$2";
         }
         if ($line =~ /\sinet6\s+([0-9a-f:]+)\/(\d+)/i) {
            push @out, "$CATEGORY\t$if\tip6address\t" . lc($1);
            push @out, "$CATEGORY\t$if\tip6networkbits\t$2";
         }
      }
   }

   return \@out;
}

#######################################################
#
# main()
#
# Emits network keys.
#
# Parameters:
#   none
#
# Returns:
#   integer exit status (1 wrong OS, 2 not applicable)
#
# Side Effects:
#   runs ip, writes STDOUT/STDERR
#
#######################################################
sub main {
   if (!checkOS({ 'linux' => undef })) {
      print STDERR "unsupported os\n";
      return 1;
   }
   unless (validCommandOnSystem({ 'ip' => undef })) {
      print STDERR "ip not found\n";
      return 2;
   }
   my @out;
   push @out, @{parseLinuxNetwork(
      runCommand('ip', '-o', 'link'),
      runCommand('ip', '-o', 'addr'),
   )};
   print join("\n", @out), "\n" if @out;
   return 0;
}

exit main() unless caller;
1;