#!/usr/bin/perl -w

# Copyright (C) 2005, 2006, 2007, 2008, 2012, 2015 Peter Palfrader <peter@palfrader.org>
#               2012 Uli Martens <uli@youam.net>
#
# 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 English;
use Getopt::Long;

$ENV{'PATH'} = '/bin:/sbin:/usr/bin:/usr/sbin';
delete @ENV{'IFS', 'CDPATH', 'ENV', 'BASH_ENV'};

my $LSOF = '/usr/bin/lsof -F0';
my $VERSION = '0.2015012901';

# nagios exit codes
my $OK = 0;
my $WARNING = 1;
my $CRITICAL = 2;
my $UNKNOWN = 3;

my $params;
my $config;

Getopt::Long::config('bundling');

sub dief {
	print STDERR @_;
	exit $UNKNOWN;
}

sub convert_time {
	my $in = shift;
	my ($ticks, $unit) = ($in =~ /^(\d+)([smhdw]?)$/);

	if ($unit eq 's' || $unit eq '') { }
	elsif ($unit eq 'm') { $ticks *= 60; }
	elsif ($unit eq 'h') { $ticks *= 60*60; }
	elsif ($unit eq 'd') { $ticks *= 60*60*24; }
	elsif ($unit eq 'w') { $ticks *= 60*60*24*7; }
	else { die "Invalid unit '$unit' in '$in'\n" }
	return $ticks;
}


if (!GetOptions (
	'--help'			=> \$params->{'help'},
	'--version'			=> \$params->{'version'},
	'--quiet'			=> \$params->{'quiet'},
	'--ignore-pid-namespaces'	=> \$params->{'ignore_pid_namespaces'},
	'--verbose'			=> \$params->{'verbose'},
	'--ignore-younger=s'		=> \$params->{'ignore_younger'},
	'-v'				=> \$params->{'verbose'},
	'--config=s'			=> \$params->{'config'},
	)) {
	dief ("$PROGRAM_NAME: Usage: $PROGRAM_NAME [--help|--version] [--ignore-pid-namespaces] [--verbose] [--quiet] [--config=<CONFIGFILE>]\n");
};
if ($params->{'help'}) {
	print "$PROGRAM_NAME: Usage: $PROGRAM_NAME [--help|--version] [--ignore-pid-namespaces] [--verbose] [--quiet] [--config=<CONFIGFILE>]\n";
	print "Reports processes that are linked against libraries that no longer exist.\n";
	print "The optional config file can specify ignore rules - see the sample config file.\n";
	print "Can optionally ignore processes from other PID namespaces.\n";
	exit (0);
};
if ($params->{'version'}) {
	print "nagios-check-libs $VERSION\n";
	print "nagios check for availability of debian (security) updates\n";
	print "Copyright (c) 2005, 2006, 2007, 2008, 2012 Peter Palfrader <peter\@palfrader.org>\n";
	exit (0);
};

if (! defined $params->{'config'}) {
	$params->{'config'} = '/etc/nagios/check-libs.conf';
} elsif (! -e $params->{'config'}) {
	dief("Config file $params->{'config'} does not exist.\n");
}

if (-e $params->{'config'}) {
	eval "use YAML::Syck; 1" or dief "you need YAML::Syck (libyaml-syck-perl) to load a config file";
	open(my $fh, '<', $params->{'config'}) or dief "Cannot open config file $params->{'config'}: $!";
	$config = LoadFile($fh);
	close($fh);
	if (!(ref($config) eq "HASH")) {
		dief("Loaded config is not a hash!\n");
	}
} else {
	$config = {
		'ignorelist' => [
			'$path =~ m#^/proc/#',
			'$path =~ m#^/var/tmp/#',
			'$path =~ m#^/SYS#',
			'$path =~ m#^/drm$# # xserver stuff',
			'$path =~ m#^/dev/zero#',
			'$path =~ m#^/dev/shm/#',
		]
	};
}

if (! exists $config->{'ignorelist'}) {
	$config->{'ignorelist'} = [];
} elsif (! (ref($config->{'ignorelist'}) eq 'ARRAY')) {
	dief("Config->ignorelist is not an array!\n");
}

my %processes;

sub getPIDs($$) {
	my ($user, $process) = @_;
	return join(', ', sort keys %{ $processes{$user}->{$process} });
};
sub getProcs($) {
	my ($user) = @_;

	return join(', ', map { $_.' ('.getPIDs($user, $_).')' } (sort {$a cmp $b} keys %{ $processes{$user} }));
};
sub getUsers() {
	return join('; ', (map { $_.': '.getProcs($_) } (sort {$a cmp $b} keys %processes)));
};
sub inVserver() {
	my ($f, $key);
	if (-e "/proc/self/vinfo" ) {
		$f = "/proc/self/vinfo";
		$key = "XID";
	} else {
		$f = "/proc/self/status";
		$key = "s_context";
	};
	open(F, "< $f") or return 0;
	while (<F>) {
		my ($k, $v) = split(/: */, $_, 2);
		if ($k eq $key) {
			close F;
			return ($v > 0);
		};
	};
	close F;
	return 0;
}
sub getYoungProcesses() {
	my $ignore_hash = {};
	if (defined $params->{'ignore_younger'}) {
		eval "use Proc::ProcessTable; 1" or die "We need Proc::ProcessTable to use --ignore-younger.\n";
		my $min_age = convert_time($params->{'ignore_younger'});
		my $cutoff = time() - $min_age;

		my $process_table = new Proc::ProcessTable(enable_ttys => 0);
		for my $p ( @{$process_table->table} ){
			$ignore_hash->{$p->pid} = 1 if $p->start > $cutoff;
		}
	}
	return $ignore_hash;
}


my $IGNORE_YOUNG_PROCESSES = getYoungProcesses();




my $INVSERVER = inVserver();

my $PID_NS_SUPPORT = (-f '/proc/self/ns/pid');
my $PID_NS;
if ($PID_NS_SUPPORT and $params->{'ignore_pid_namespaces'}) {
	$PID_NS = readlink('/proc/self/ns/pid');
}

print STDERR "Running $LSOF -n\n" if $params->{'verbose'};
open (LSOF, "$LSOF -n 2>/dev/null|") or dief ("Cannot run $LSOF -n: $!\n");
my @lsof=<LSOF>;
close LSOF;
if ($CHILD_ERROR) { # program failed
	dief("$LSOF -n returned with non-zero exit code: ".($CHILD_ERROR / 256)."\n");
};

my ($process, $pid, $user);
LINE: for my $line (@lsof)  {
	if ( $line =~ /^p/ ) {
		my %fields = map { m/^(.)(.*)$/ ; $1 => $2 } grep { defined $_  and length $_ >1} split /\0/, $line;
		$process = $fields{c};
		$pid     = $fields{p};
		$user    = $fields{L} || '<unknown>';
		next;
	}

	if ($PID_NS_SUPPORT and $params->{'ignore_pid_namespaces'}) {
		my $pidns = readlink('/proc/'.$pid.'/ns/pid');
		next if (defined $pidns and $PID_NS ne $pidns);
	}

	unless ( $line =~ /^f/ ) {
		dief("UNKNOWN strange line read from lsof\n");
		# don't print it because it contains NULL characters...
	}

	my %fields = map { m/^(.)(.*)$/ ; $1 => $2 } grep { defined $_  and length $_ >1} split /\0/, $line;

	my $fd    = $fields{f};
	my $inode = $fields{i};
	my $path  = $fields{n};
	if ($path =~ m/\.dpkg-/ || $path =~ m/\(deleted\)/ || $path =~ /path inode=/ || $path =~ m#/\.nfs# || $fd eq 'DEL') {
		my $deleted_in_path = ($path =~ m/\(deleted\)/ || $path =~ m/\.nfs/);
		next if ($deleted_in_path && $fd =~ /^[0-9]*$/); # Ignore deleted files that are open via normal file handles.
		next if ($deleted_in_path && $fd eq 'cwd'); # Ignore deleted directories that we happen to be in.

		$path =~ s/^\(deleted\)//; # in some cases "(deleted)" is at the beginning of the string
		for my $i (@{$config->{'ignorelist'}}) {
			my $ignore = eval($i);
			next LINE if $ignore;
		}
		next if ($INVSERVER && ($process eq 'init') && ($pid == 1) && ($user eq 'root'));
		if (exists $IGNORE_YOUNG_PROCESSES->{$pid}) {
			if ( $params->{'verbose'} ) {
				print STDERR "ignoring young $process($pid) because of [$path]:\n";
				print STDERR $line;
			}
			next LINE
		}
		if ( $params->{'verbose'} ) {
			print STDERR "adding $process($pid) because of [$path]:\n";
			print STDERR $line;
		}
		$processes{$user}->{$process}->{$pid} = 1;
	};
};



my $message='';
my $exit = $OK;
if (keys %processes) {
	$exit = $WARNING;
	$message = 'The following processes have libs linked that were upgraded: '. getUsers()."\n";
} else {
	$message = "No upgraded libs linked in running processes\n" unless $params->{'quiet'};
};

print $message;
exit $exit;