#!/usr/bin/perl
# nagios: -epn

# dsa-check-packages

# checks for obsolete/local and upgradeable packages.
#
# packages for the obsolete/local check can be ignored, by
# listing their full name in /etc/nagios/obsolete-packages-ignore
# or by having a regex (starting a line with "/") that matches
# the packagename in said file.
#
# Takes one optional argument, the location of the ignore file.


# Copyright (C) 2008, 2009 Peter Palfrader <peter@palfrader.org>
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

use strict;
use warnings;
use English;

my $IGNORE = "/etc/nagios-plugins/obsolete-packages-ignore";
my $IGNORED = "/etc/nagios-plugins/obsolete-packages-ignore.d";

my %CODE = (
	'OK'            => 0,
	'WARNING'       => 1,
	'CRITICAL'      => 2,
	'UNKNOWN'       => 3
);
my $EXITCODE = 'OK';
sub record($) {
	my ($newexit) = @_;
	die "code $newexit not defined\n" unless defined $CODE{$newexit};

	if ($CODE{$newexit} > $CODE{$EXITCODE}) {
		$EXITCODE = $newexit;
	};
}



sub get_packages {
	$ENV{'COLUMNS'} = 1000;
	$ENV{'LC_ALL'} = 'C';
	open(F, "dpkg -l|") or die ("Cannot run dpkg: $!\n");
	my @lines = <F>;
	close(F);
	chomp(@lines);

	my $line;
	my $has_arch = 0;
	while (defined($line = shift @lines) && ($line !~ /\+\+\+/)) {
		if ($line =~ /Architecture/) { $has_arch = 1; }
	}

	my %pkgs;
	for $line (@lines) {
		my ($state, $pkg, $version, $arch, undef) = split(/  */, $line);
		$arch = '' unless $has_arch;
		$pkgs{$state}{$pkg} = { 'installed' => $version, arch => $arch }
	}

	my $installed = $pkgs{'ii'};
	delete $pkgs{'ii'};

	my @installed_packages = keys(%$installed);
	my @cmd = ("apt-cache", "policy", @installed_packages);

	open my $olderr, ">&STDERR"   or die "Can't dup STDERR: $!";
	open     STDERR, ">/dev/null" or die "Can't dup STDOUT: $!";
	open (F, "-|", @cmd) or die ("Cannot run apt-cache policy: $!\n");
	@lines = <F>;
	close(F);
	open STDERR, ">&", $olderr  or die "Can't dup OLDERR: $!";
	chomp(@lines);

	my $pkgname = undef;
	my $candidate_found = 0;
	while (defined($line = shift @lines)) {
		if ($line =~ /^([^ ]*):$/) {
			# when we have multi-arch capable fu, we require that
			# apt-cache policy output is in the same order as its
			# arguments.
			#
			# We needs thi, because the output block in apt-cache
			# policy does not show the arch:
			#
			# | weasel@stanley:~$ apt-cache policy libedit2:amd64
			# | libedit2:
			# |   Installed: 2.11-20080614-5
			# |   Candidate: 2.11-20080614-5
			#
			# We replace the package name in the output with the
			# one we asked for ($pkg:$arch) - but to match this up
			# sanely we need the order to be correct.
			#
			# For squeeze systems (no m-a), apt-cache policy output
			# is all different.
			$pkgname = $1;
			$candidate_found = 0;
			if ($has_arch) {
				my $from_list = shift @installed_packages;
				next if ($pkgname eq $from_list); # no :$arch in pkgname we asked for

				my $ma_fix_pkgname = $pkgname.':'.$installed->{$from_list}->{'arch'};
				my $ma_fix_from_list = $from_list.':'.$installed->{$from_list}->{'arch'};

				if ($pkgname eq $ma_fix_from_list || # e.g. ia32-libs-i386.  dpkg -l: ia32-libs-i386, apt-cache policy: ia32-libs-i386:i386
				    $ma_fix_pkgname eq $from_list) {
					$pkgname = $from_list;
				} else {
					die "Unexpected order mismatch in apt-cache policy output (apt-cache policy name: $pkgname - dpkg -l name: $from_list)\n";
				}
			}
		} elsif ($line =~ /^ +Installed: (.*)$/) {
			# etch dpkg -l does not print epochs, so use this info, it's better
			$installed->{$pkgname}{'installed'} = $1;
			# initialize security-update
			$installed->{$pkgname}{'security-update'} = 0;
		} elsif ($line =~ /^ +Candidate: (.*)$/) {
			$installed->{$pkgname}{'candidate'} = $1;
		} elsif ($line =~ /     ([^ ]+) [0-9]+/) {
			# check if the next lines show the sources of our candidate
			if ($1 eq $installed->{$pkgname}{'candidate'}) {
				$candidate_found = 1;
			}
		} elsif (($line =~ / +[0-9]+ [^ ]+\/(security\.([^ ]+\.)?debian\.org|debian-security).*\/updates\//) && $candidate_found ) {
			$installed->{$pkgname}{'security-update'} = 1;
		} elsif ($line =~ /^ +\*\*\*/) {
			$line = shift @lines;
			my @l = split(/ +/, $line);
			$installed->{$pkgname}{'origin'} = $l[2];
			$candidate_found = 0;
		}
	}

	my (%current, %obsolete, %outofdate, %security_outofdate);
	for my $pkgname (keys %$installed) {
		my $pkg = $installed->{$pkgname};

		unless (defined($pkg->{'candidate'}) && defined($pkg->{'origin'})) {
			$obsolete{$pkgname} = $pkg;
			next;
		}

		if ($pkg->{'candidate'} ne $pkg->{'installed'}) {
			if ($pkg->{'security-update'}) {
				$security_outofdate{$pkgname} = $pkg;
			} else {
				$outofdate{$pkgname} = $pkg;
			}
			next;
		};
		if ($pkg->{'origin'} eq '/var/lib/dpkg/status') {
			$obsolete{$pkgname} = $pkg;
			next;
		}
		$current{$pkgname} = $pkg;
	}

	$pkgs{'current'} = \%current;
	$pkgs{'outofdate'} = \%outofdate;
	$pkgs{'security_outofdate'} = \%security_outofdate;
	$pkgs{'obsolete'} = \%obsolete;
	return \%pkgs;
}

sub load_ignores {
	my ($ignorefiles, $require_file) = @_;

	my @ignores;

	for my $ignoreitem (@$ignorefiles) {
		next if (!$require_file and ! -e $ignoreitem);

		my @filestoopen;
		if (-d $ignoreitem) {
			opendir(DIR, $ignoreitem) or die ("Cannot open dir $ignoreitem: $!\n");
			@filestoopen = readdir(DIR);
			closedir(DIR);

			@filestoopen = grep { -f ($ignoreitem.'/'.$_) } @filestoopen;
			@filestoopen = grep { /^([a-z0-9_.-]+)+[a-z0-9]+$/i } @filestoopen;
			@filestoopen = grep { !/dpkg-(old|dist|new|tmp)$/ } @filestoopen;
			@filestoopen = map { ($ignoreitem.'/'.$_) } @filestoopen;
		} else {
			push @filestoopen, $ignoreitem;
		}

		for my $f (@filestoopen) {
			open (F, "< $f") or die ("Cannot open $f: $!\n");
			push @ignores, <F>;
			close F;
		}
	}
	chomp(@ignores);
	return \@ignores;
}

sub check_ignore {
	my ($pkg, $ignores) = @_;

	my $ignore_this = 0;
	for my $ignore (@$ignores) {
		my $ig = $ignore;
		return 1 if ($ig eq $pkg);
		if (substr($ig,0,1) eq '/') {
			substr($ig, 0, 1, '');
			$ig =~ s,/$,,;
			return 1 if ($pkg =~ /$ig/);
		}
	}
	return 0
}

sub filter_ignored {
	my ($packages, $ignores) = @_;

	my $obs = $packages->{'obsolete'};

	my (%ignored, %bad);
	for my $pkg (keys %$obs) {
		if (check_ignore($pkg, $ignores)) {
			$ignored{$pkg} = $obs->{$pkg};
		} else {
			$bad{$pkg} = $obs->{$pkg};
		};
	}
	delete $packages->{'obsolete'};
	$packages->{'obsolete'} = \%bad;
	$packages->{'obsolete-ignored'} = \%ignored;
};

sub usage {
	my ($fd, $exit) = @_;
	print $fd "Usage: $PROGRAM_NAME [<ignorefile|dir> [<ignorefile|dir> ...]]\n";
	exit $exit;
}

my $ignorefiles = [$IGNORE, $IGNORED];
my $ignorefile_userset = 0;
if (@ARGV >= 1) {
	usage(\*STDOUT, 0) if ($ARGV[0] eq "-h");
	usage(\*STDOUT, 0) if ($ARGV[0] eq "--help");
	$ignorefile_userset = 1;
	$ignorefiles = \@ARGV;
};

my $ignores = load_ignores($ignorefiles, $ignorefile_userset);
my $packages = get_packages();

filter_ignored($packages, $ignores);



my @reportform = (
	{ 'key' => 'obsolete',
	  'listpackages' => 1,
	  'long' => "%d local or obsolete packages: %s",
	  'short' => "%d obs/loc",
	  'perf' => "obs_loc=%d;1;5;0",
	  'status' => 'WARNING' },
	{ 'key' => 'outofdate',
	  'listpackages' => 1,
	  'long' => "%d out of date packages: %s",
	  'short' => "%d updates",
	  'perf' => "outdated=%d;1;5;0",
	  'status' => 'WARNING' },
	{ 'key' => 'current',
	  'listpackages' => 0,
	  'long' => "%d packages current.",
	  'short' => "%d ok",
	  'perf' => "current=%d;;;0",
	  'status' => 'OK' },
	{ 'key' => 'obsolete-ignored',
	  'listpackages' => 1,
	  'long' => "%d whitelisted local or obsolete packages: %s",
	  'short' => "%d obs/loc(ignored)",
	  'perf' => "obs_ign=%d;;;0",
	  'status' => 'OK' },
	{ 'key' => 'rc',
	  'listpackages' => 1,
	  'long' => "%d packages removed but not purged: %s",
	  'short' => "%d rc",
	  'perf' => "rm_unprg=%d;;;0",
	  'status' => 'OK' },
	{ 'key' => 'hi',
	  'listpackages' => 1,
	  'long' => "%d packages on hold: %s",
	  'short' => "%d hi",
	  'perf' => "hold=%d;;;0",
	  'status' => 'OK' },
	{ 'key' => 'pc',
	  'listpackages' => 1,
	  'long' => "%d packages requested to be purged but conffiles still installed: %s",
	  'short' => "%d pc",
	  'perf' => "prg_conf=%d;1;;0",
	  'status' => 'WARNING' },
	{ 'key' => 'security_outofdate',
	  'listpackages' => 1,
	  'long' => "%d packages with outstanding security updates: %s",
	  'short' => "%d security-updates",
	  'perf' => "security_outdated=%d;;1;0",
	  'status' => 'CRITICAL' },
	);

my @longout;
my @perfout;
my @shortout;
for my $form (@reportform) {
	my $pkgs = $packages->{$form->{'key'}};
	delete $packages->{$form->{'key'}};
	my $num = scalar keys %$pkgs;
	push @perfout, sprintf($form->{'perf'}, $num);
	next unless ($num > 0);
	if ($form->{'listpackages'}) {
		my $list = join(" ", keys %$pkgs);
		push @longout, sprintf($form->{'long'}, $num, $list);
	} else {
		push @longout, sprintf($form->{'long'}, $num);
	};
	push @shortout, sprintf($form->{'short'}, $num);
	record($form->{'status'});
};
if (scalar keys %$packages) {
	record('WARNING');
	unshift @shortout, "unk: ".join(" ", keys %$packages);
	for my $status (sort {$b cmp $a} keys %$packages) {
		my $pkgs = $packages->{$status};
		my $list = join(" ", keys %$pkgs);
		unshift @longout, "Unknown package status $status: $list";
	};
}

my $shortout = $EXITCODE.": ".join(" ", @shortout);
my $longout = join("\n", @longout);
my $perfout = "|".join(" ", @perfout);

print $shortout,"\n";
print $longout,"\n";
print $perfout,"\n";

exit $CODE{$EXITCODE};