#!/usr/bin/perl

# this software is licensed for use under the Free Software Foundation's GPL v3.0 license, as retrieved
# from http://www.gnu.org/licenses/gpl-3.0.html on 2014-11-17.  A copy should also be available in this
# project's Git repository at https://github.com/jimsalterjrs/sanoid/blob/master/LICENSE.

$::VERSION = '1.4.17';

use strict;
use warnings;
use Config::IniFiles; # read samba-style conf file
use Data::Dumper;     # debugging - print contents of hash
use File::Path;       # for rmtree command in use_prune
use Getopt::Long qw(:config auto_version auto_help);
use Pod::Usage;       # pod2usage
use Time::Local;      # to parse dates in reverse

my %args = ("cron" => 1, "verbose" => 1, "configdir" => "/etc/sanoid");
GetOptions(\%args, "verbose", "debug", "cron", "readonly", "quiet",
                   "monitor-health", "force-update", "configdir=s",
                   "monitor-snapshots", "take-snapshots", "prune-snapshots"
          ) or pod2usage(2);

my $pscmd = '/bin/ps';

my $zfs = '/sbin/zfs';

my $conf_file = "$args{'configdir'}/sanoid.conf";
my $default_conf_file = "$args{'configdir'}/sanoid.defaults.conf";

# parse config file
my %config = init($conf_file,$default_conf_file);

# if we call getsnaps(%config,1) it will forcibly update the cache, TTL or no TTL
my $forcecacheupdate = 0;
my $cacheTTL = 900; # 15 minutes
my %snaps = getsnaps( \%config, $cacheTTL, $forcecacheupdate );

my %snapsbytype = getsnapsbytype( \%config, \%snaps );

my %snapsbypath = getsnapsbypath( \%config, \%snaps );

# let's make it a little easier to be consistent passing these hashes in the same order to each sub
my @params = ( \%config, \%snaps, \%snapsbytype, \%snapsbypath );

if ($args{'debug'})		{ $args{'verbose'}=1; blabber (@params); }
if ($args{'monitor-snapshots'}) { monitor_snapshots(@params); }
if ($args{'monitor-health'}) 	{ monitor_health(@params); }
if ($args{'force-update'}) 	{ my $snaps = getsnaps( \%config, $cacheTTL, 1 ); } 

if ($args{'cron'}) {
	if ($args{'quiet'}) { $args{'verbose'} = 0; }
	take_snapshots (@params);
	prune_snapshots (@params);
} else {
	if ($args{'take-snapshots'}) { take_snapshots (@params); }
	if ($args{'prune-snapshots'}) { prune_snapshots (@params); }
}

exit 0;
 

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sub monitor_health() {
	my ($config, $snaps, $snapsbytype, $snapsbypath) = @_;
	my %pools;
	my @messages;
	my $errlevel=0;

	foreach my $path (keys %{ $snapsbypath}) {
		my @pool = split ('/',$path);
		$pools{$pool[0]}=1;
	}

	foreach my $pool (keys %pools) {
		my ($exitcode, $msg) = check_zpool($pool,2);
		if ($exitcode > $errlevel) { $errlevel = $exitcode; }
		chomp $msg;
		push (@messages, $msg);
	}

	my @warninglevels = ('','*** WARNING *** ','*** CRITICAL *** ');
	my $message = $warninglevels[$errlevel] . join (', ',@messages);
	print "$message\n";
	exit $errlevel;

} # end monitor_health()

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sub monitor_snapshots() {

	# nagios plugin format: exit 0,1,2,3 for OK, WARN, CRITICAL, or ERROR.
	
	# check_snapshot_date - test ZFS fs creation timestamp for recentness
	# accepts arguments: $filesystem, $warn (in seconds elapsed), $crit (in seconds elapsed)

	my ($config, $snaps, $snapsbytype, $snapsbypath) = @_;
	my %datestamp = get_date();
	my $errorlevel = 0;
	my $msg;
	my @msgs;
	my @paths;

	foreach my $section (keys %config) {
		if ($section =~ /^template/) { next; }
		if (! $config{$section}{'monitor'}) { next; }
		if ($config{$section}{'process_children_only'}) { next; }		

		my $path = $config{$section}{'path'};
		push @paths, $path;

		my @types = ('yearly','monthly','daily','hourly');
		foreach my $type (@types) {
			
			my $smallerperiod = 0;
			# we need to set the period length in seconds first
			if ($type eq 'hourly') { $smallerperiod = 60; }
			elsif ($type eq 'daily') { $smallerperiod = 60*60; }
			elsif ($type eq 'monthly') { $smallerperiod = 60*60*24; }
			elsif ($type eq 'yearly') { $smallerperiod = 60*60*24; }

			my $typewarn = $type . '_warn';
			my $typecrit = $type . '_crit';
			my $warn = $config{$section}{$typewarn} * $smallerperiod;
			my $crit = $config{$section}{$typecrit} * $smallerperiod;
			my $elapsed = -1;
			if (defined $snapsbytype{$path}{$type}{'newest'}) { $elapsed = $snapsbytype{$path}{$type}{'newest'}; }
			my $dispelapsed = displaytime($snapsbytype{$path}{$type}{'newest'});
			my $dispwarn = displaytime($warn);
			my $dispcrit = displaytime($crit);
			if ( $elapsed > $crit || $elapsed == -1) { 
				if ($config{$section}{$typecrit} > 0) {
					if (! $config{$section}{'monitor_dont_crit'}) { $errorlevel = 2; }
					if ($elapsed == -1) {
						push @msgs, "CRIT: $path has no $type snapshots at all!";
					} else {
						push @msgs, "CRIT: $path\'s newest $type snapshot is $dispelapsed old (should be < $dispcrit)";
					}
				}
			 } elsif ($elapsed > $warn) {
				if ($config{$section}{$typewarn} > 0) {
					if (! $config{$section}{'monitor_dont_warn'} && ($errorlevel < 2) ) { $errorlevel = 1; }
					push @msgs, "WARN: $path\'s newest $type snapshot is $dispelapsed old (should be < $dispwarn)";
				}
			} else {
				# push @msgs .= "OK: $path\'s newest $type snapshot is $dispelapsed old \n";
			}
			
		}
	}
	
	my @sorted_msgs = sort { lc($a) cmp lc($b) } @msgs;
	my @sorted_paths = sort { lc($a) cmp lc($b) } @paths;
	$msg = join (", ", @sorted_msgs);
	my $paths = join (", ", @sorted_paths);
	
	if ($msg eq '') { $msg = "OK: all monitored datasets \($paths\) have fresh snapshots"; }
	
	print "$msg\n";
	exit $errorlevel;
} # end monitor()

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sub prune_snapshots {

	if ($args{'verbose'}) { print "INFO: pruning snapshots...\n"; }
	my ($config, $snaps, $snapsbytype, $snapsbypath) = @_;

	my %datestamp = get_date();
	my $forcecacheupdate = 0;

	foreach my $section (keys %config) {
		if ($section =~ /^template/) { next; }
		if (! $config{$section}{'autoprune'}) { next; }
		if ($config{$section}{'process_children_only'}) { next; }

		my $path = $config{$section}{'path'};

		my $period = 0;

		foreach my $type (keys %{ $config{$section} }){
			unless ($type =~ /ly$/) { next; }

			# we need to set the period length in seconds first
			if ($type eq 'hourly') { $period = 60*60; }
			elsif ($type eq 'daily') { $period = 60*60*24; }
			elsif ($type eq 'monthly') { $period = 60*60*24*31; }
			elsif ($type eq 'yearly') { $period = 60*60*24*365.25; }

			# avoid pissing off use warnings by not executing this block if no matching snaps exist
			if (defined $snapsbytype{$path}{$type}{'sorted'}) {
				my @sorted = split (/\|/,$snapsbytype{$path}{$type}{'sorted'});
			
				# if we say "daily=30" we really mean "don't keep any dailies more than 30 days old", etc
				my $maxage = ( time() - $config{$section}{$type} * $period );
				# but if we say "daily=30" we ALSO mean "don't get rid of ANY dailies unless we have more than 30".
				my $minsnapsthistype = $config{$section}{$type};

				# how many total snaps of this type do we currently have?
				my $numsnapsthistype = scalar (@sorted);

				my @prunesnaps;
				foreach my $snap( @sorted ){
					# print "snap $path\@$snap has age $snaps{$path}{$snap}{'ctime'}, maxage is $maxage.\n";
					if ( ($snaps{$path}{$snap}{'ctime'} < $maxage) && ($numsnapsthistype > $minsnapsthistype) ) {
						my $fullpath = $path . '@' . $snap;
						push(@prunesnaps,$fullpath);
						# we just got rid of a snap, so we now have one fewer, duh
						$numsnapsthistype--;
					}
				}

				if ((scalar @prunesnaps) > 0) {
					# print "found some snaps to prune!\n"
					if (checklock('sanoid_pruning')) {
						writelock('sanoid_pruning');
						foreach my $snap( @prunesnaps ){
							if ($args{'verbose'}) { print "INFO: pruning $snap ... \n"; }
							if (iszfsbusy($path)) {
								print "INFO: deferring pruning of $snap - $path is currently in zfs send or receive.\n";
							} else {
								if (! $args{'readonly'}) { system($zfs, "destroy",$snap) == 0 or warn "could not remove $snap : $?"; }
							}
						}
						removelock('sanoid_pruning');
						$forcecacheupdate = 1;
						%snaps = getsnaps(%config,$cacheTTL,$forcecacheupdate);
					} else {
						print "INFO: deferring snapshot pruning - valid pruning lock held by other sanoid process.\n";
					}
				}
			}
		}
	}


} # end prune_snapshots


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sub take_snapshots {

	my ($config, $snaps, $snapsbytype, $snapsbypath) = @_;

	my %datestamp = get_date();
	my $forcecacheupdate = 0;

	my @newsnaps;

	if ($args{'verbose'}) { print "INFO: taking snapshots...\n"; }
	foreach my $section (keys %config) {
		if ($section =~ /^template/) { next; }
		if (! $config{$section}{'autosnap'}) { next; }
		if ($config{$section}{'process_children_only'}) { next; }		

		my $path = $config{$section}{'path'};

		foreach my $type (keys %{ $config{$section} }){
			unless ($type =~ /ly$/) { next; }
			if ($config{$section}{$type} > 0) {

				my $newestage; # in seconds
				if (defined $snapsbytype{$path}{$type}{'newest'}) {
					$newestage = $snapsbytype{$path}{$type}{'newest'};
				} else{
					$newestage = 9999999999999999;	
				}

				# for use with localtime: @preferredtime will be most recent preferred snapshot time in ($sec,$min,$hour,$mon-1,$year) format
				my @preferredtime;
				my $lastpreferred;

				if ($type eq 'hourly')     { 
					push @preferredtime,0; # try to hit 0 seconds
					push @preferredtime,$config{$section}{'hourly_min'};
					push @preferredtime,$datestamp{'hour'};
					push @preferredtime,$datestamp{'mday'};
					push @preferredtime,($datestamp{'mon'}-1); # january is month 0
					push @preferredtime,$datestamp{'year'};
					$lastpreferred = timelocal(@preferredtime);
					if ($lastpreferred > time()) { $lastpreferred -= 60*60; } # preferred time is later this hour - so look at last hour's
				} elsif ($type eq 'daily')   { 
					push @preferredtime,0; # try to hit 0 seconds
					push @preferredtime,$config{$section}{'daily_min'};
					push @preferredtime,$config{$section}{'daily_hour'};
					push @preferredtime,$datestamp{'mday'};
					push @preferredtime,($datestamp{'mon'}-1); # january is month 0
					push @preferredtime,$datestamp{'year'};
					$lastpreferred = timelocal(@preferredtime);
					if ($lastpreferred > time()) { $lastpreferred -= 60*60*24; } # preferred time is later today - so look at yesterday's
				} elsif ($type eq 'monthly') { 
					push @preferredtime,0; # try to hit 0 seconds
					push @preferredtime,$config{$section}{'monthly_min'};
					push @preferredtime,$config{$section}{'monthly_hour'};
					push @preferredtime,$config{$section}{'monthly_mday'};
					push @preferredtime,($datestamp{'mon'}-1); # january is month 0
					push @preferredtime,$datestamp{'year'};
					$lastpreferred = timelocal(@preferredtime);
					if ($lastpreferred > time()) { $lastpreferred -= 60*60*24*31; } # preferred time is later this month - so look at last month's
				} elsif ($type eq 'yearly')  { 
					push @preferredtime,0; # try to hit 0 seconds
					push @preferredtime,$config{$section}{'yearly_min'};
					push @preferredtime,$config{$section}{'yearly_hour'};
					push @preferredtime,$config{$section}{'yearly_mday'};
					push @preferredtime,($config{$section}{'yearly_mon'}-1); # january is month 0
					push @preferredtime,$datestamp{'year'};
					$lastpreferred = timelocal(@preferredtime);
					if ($lastpreferred > time()) { $lastpreferred -= 60*60*24*31*365.25; } # preferred time is later this year - so look at last year
				}

				# reconstruct our human-formatted most recent preferred snapshot time into an epoch time, to compare with the epoch of our most recent snapshot
				my $maxage = time()-$lastpreferred;
				
				if ( $newestage > $maxage ) {
					# update to most current possible datestamp
					%datestamp = get_date();
					# print "we should have had a $type snapshot of $path $maxage seconds ago; most recent is $newestage seconds old.\n";
					push(@newsnaps, "$path\@autosnap_$datestamp{'sortable'}_$type");
				}
			}
		}
	}

	if ( (scalar(@newsnaps)) > 0) {
		foreach my $snap ( @newsnaps ) {
			if ($args{'verbose'}) { print "taking snapshot $snap\n"; }
			if (!$args{'readonly'}) { 
				system($zfs, "snapshot", "$snap") == 0
					or warn "CRITICAL ERROR: $zfs snapshot $snap failed, $?";
				# make sure we don't end up with multiple snapshots with the same ctime
				sleep 1;
			}
		}
		$forcecacheupdate = 1;
		%snaps = getsnaps(%config,$cacheTTL,$forcecacheupdate);
	}
}

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sub blabber {

	my ($config, $snaps, $snapsbytype, $snapsbypath) = @_;

	$Data::Dumper::Sortkeys = 1;
	print "****** CONFIGS ******\n";
	print Dumper(\%config);
	#print "****** SNAPSHOTS ******\n";
	#print Dumper(\%snaps);
	#print "****** SNAPSBYTYPE ******\n";
	#print Dumper(\%snapsbytype);
	#print "****** SNAPSBYPATH ******\n";
	#print Dumper(\%snapsbypath);
	
	print "\n";
	
	foreach my $section (keys %config) {
		my $path = $config{$section}{'path'};
		print "Filesystem $path has:\n";
		print "     $snapsbypath{$path}{'numsnaps'} total snapshots ";
		print "(newest: ";
		my $newest = sprintf("%.1f",$snapsbypath{$path}{'newest'} / 60 / 60);
		print "$newest hours old)\n";
	
		foreach my $type (keys %{ $snapsbytype{$path} }){
			print "          $snapsbytype{$path}{$type}{'numsnaps'} $type\n";
			print "              desired: $config{$section}{$type}\n";
			print "              newest: ";
			my $newest = sprintf("%.1f",($snapsbytype{$path}{$type}{'newest'} / 60 / 60));
			print "$newest hours old, named $snapsbytype{$path}{$type}{'newestname'}\n";
		}
		print "\n\n";
	}
	
} # end blabber


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sub getsnapsbytype {
	
	my ($config, $snaps) = @_;
	my %snapsbytype;

	# iterate through each module section - each section is a single ZFS path
	foreach my $section (keys %config) {
		my $path = $config{$section}{'path'};

		my %rawsnaps;
		foreach my $name (keys %{ $snaps{$path} }){
			my $type = $snaps{$path}{$name}{'type'};
			$rawsnaps{$type}{$name} = $snaps{$path}{$name}{'ctime'}
		}

		# iterate through snapshots of each type, ordered by creation time of each snapshot within that type
		foreach my $type (keys %rawsnaps) {
			$snapsbytype{$path}{$type}{'numsnaps'} = scalar (keys %{ $rawsnaps{$type} });
			my @sortedsnaps;	
			foreach my $name (
				sort { $rawsnaps{$type}{$a} <=> $rawsnaps{$type}{$b} } keys %{ $rawsnaps{$type} }
				) {
				push @sortedsnaps, $name;
				$snapsbytype{$path}{$type}{'newest'} = (time-$snaps{$path}{$name}{'ctime'});
				$snapsbytype{$path}{$type}{'newestname'} = $name;
			}
			$snapsbytype{$path}{$type}{'sorted'} = join ('|',@sortedsnaps);
		}
	}

	return %snapsbytype;
	
} # end getsnapsbytype


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sub getsnapsbypath {
	
	my ($config,$snaps) = @_;
	my %snapsbypath;
	
	# iterate through each module section - each section is a single ZFS path
	foreach my $section (keys %config) {
		my $path = $config{$section}{'path'};
		$snapsbypath{$path}{'numsnaps'} = scalar (keys %{ $snaps{$path} });
		
		# iterate through snapshots of each type, ordered by creation time of each snapshot within that type
		my %rawsnaps;
		foreach my $snapname ( keys %{ $snaps{$path} } ) {
			$rawsnaps{$path}{$snapname} = $snaps{$path}{$snapname}{'ctime'};
		}
		my @sortedsnaps;
		foreach my $snapname ( 
				sort { $rawsnaps{$path}{$a} <=> $rawsnaps{$path}{$b} } keys %{ $rawsnaps{$path} }
				) {
				push @sortedsnaps, $snapname;
				$snapsbypath{$path}{'newest'} = (time-$snaps{$path}{$snapname}{'ctime'});
		}
		my $sortedsnaps = join ('|',@sortedsnaps);
		$snapsbypath{$path}{'sorted'} = $sortedsnaps;
	}
	
	return %snapsbypath;
	
} # end getsnapsbypath




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sub getsnaps {

	my ($config, $cacheTTL, $forcecacheupdate) = @_;

	my $cache = '/var/cache/sanoidsnapshots.txt';
	my @rawsnaps;
	
	my ($dev,$ino,$mode,$nlink,$uid,$gid,$rdev,$size,
       		$atime,$mtime,$ctime,$blksize,$blocks)
           	= stat($cache);

	if ( $forcecacheupdate || (time() - $mtime) > $cacheTTL ) {
		if (checklock('sanoid_cacheupdate')) {
			writelock('sanoid_cacheupdate');
			if ($args{'verbose'}) { 
				if ($args{'force-update'}) {
					print "INFO: cache forcibly expired - updating from zfs list.\n";
				} else {
					print "INFO: cache expired - updating from zfs list.\n"; 
				}
			}
			open FH, "$zfs get -Hpt snapshot creation |";
			@rawsnaps = <FH>;
			close FH;
	
			open FH, "> $cache" or die 'Could not write to $cache!\n';
			print FH @rawsnaps;
			close FH;
			removelock('sanoid_cacheupdate');
		} else {
			if ($args{'verbose'}) { print "INFO: deferring cache update - valid cache update lock held by another sanoid process.\n"; }
			open FH, "< $cache";
			@rawsnaps = <FH>;
			close FH;
		}
	} else {
		# if ($args{'debug'}) { print "DEBUG: cache not expired (" . (time() - $mtime) . " seconds old with TTL of $cacheTTL): pulling snapshot list from cache.\n"; }
		open FH, "< $cache";
		@rawsnaps = <FH>;
		close FH;
	}

	foreach my $snap (@rawsnaps) {
		my ($fs,$snapname,$snapdate) = ($snap =~ m/(.*)\@(.*ly)\s*creation\s*(\d*)/);

		# avoid pissing off use warnings
		if (defined $snapname) {
			my ($snaptype) = ($snapname =~ m/.*_(\w*ly)/);
			if ($snapname =~ /^autosnap/) {
				$snaps{$fs}{$snapname}{'ctime'}=$snapdate;
				$snaps{$fs}{$snapname}{'type'}=$snaptype;
			}
		}
	}

	return %snaps;
}

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sub init {
	my ($conf_file, $default_conf_file) = @_;
	my %config;

	unless (-e $default_conf_file ) { die "FATAL: cannot load $default_conf_file - please restore a clean copy, this is not a user-editable file!"; }
	unless (-e $conf_file ) { die "FATAL: cannot load $conf_file - please create a valid local config file before running sanoid!"; }

	tie my %defaults, 'Config::IniFiles', ( -file => $default_conf_file ) or die "FATAL: cannot load $default_conf_file - please restore a clean copy, this is not a user-editable file!";
	tie my %ini, 'Config::IniFiles', ( -file => $conf_file ) or die "FATAL: cannot load $conf_file - please create a valid local config file before running sanoid!";

	# we'll use these later to normalize potentially true and false values on any toggle keys
	my @toggles = ('autosnap','autoprune','monitor_dont_warn','monitor_dont_crit','monitor','recursive','process_children_only');
	my @istrue=(1,"true","True","TRUE","yes","Yes","YES","on","On","ON");
	my @isfalse=(0,"false","False","FALSE","no","No","NO","off","Off","OFF");
	
	foreach my $section (keys %ini) {

		# first up - die with honor if unknown parameters are set in any modules or templates by the user.
		foreach my $key (keys %{$ini{$section}}) {
			if (! defined ($defaults{'template_default'}{$key})) {
				die "FATAL ERROR: I don't understand the setting $key you've set in \[$section\] in $conf_file.\n";
			}
		}

		if ($section =~ /^template_/) { next; } # don't process templates directly
		
		# only set defaults on sections that haven't already been initialized - this allows us to override values
		# for sections directly when they've already been defined recursively, without starting them over from scratch.
		if (! defined ($config{$section}{'initialized'})) {
			if ($args{'debug'}) { print "DEBUG: initializing \$config\{$section\} with default values from $default_conf_file.\n"; }
			# set default values from %defaults, which can then be overriden by template
			# and/or local settings within the module.
			foreach my $key (keys %{$defaults{'template_default'}}) {
				if (! ($key =~ /template|recursive|children_only/)) { 
					$config{$section}{$key} = $defaults{'template_default'}{$key}; 
				}
			}
	
			# override with values from user-defined default template, if any
	
			foreach my $key (keys %{$ini{'template_default'}}) {
				if (! ($key =~ /template|recursive/)) { 
				if ($args{'debug'}) { print "DEBUG: overriding $key on $section with value from user-defined default template.\n"; }
					$config{$section}{$key} = $ini{'template_default'}{$key}; 
				}
			}
		}

		# override with values from user-defined templates applied to this module,
		# in the order they were specified (ie use_template = default,production,mytemplate)
		if (defined $ini{$section}{'use_template'}) {
			my @templates = split (' *, *',$ini{$section}{'use_template'});
			foreach my $rawtemplate (@templates) {
				# strip trailing whitespace
				$rawtemplate =~ s/\s+$//g;

				my $template = 'template_'.$rawtemplate;
				foreach my $key (keys %{$ini{$template}}) {
					if (! ($key =~ /template|recursive/)) { 
						if ($args{'debug'}) { print "DEBUG: overriding $key on $section with value from user-defined template $template.\n"; }
						$config{$section}{$key} = $ini{$template}{$key}; 
					}
				}
			}
		}

		# override with any locally set values in the module itself
		foreach my $key (keys %{$ini{$section}} ) {
			if (! ($key =~ /template|recursive/)) {
				if ($args{'debug'}) { print "DEBUG: overriding $key on $section with value directly set in module.\n"; }
				$config{$section}{$key} = $ini{$section}{$key};
			}
		}
	
		# make sure that true values are true and false values are false for any toggled values
		foreach my $toggle(@toggles) {
			foreach my $true (@istrue) {	
				if (defined $config{$section}{$toggle} && $config{$section}{$toggle} eq $true) { $config{$section}{$toggle} = 1; }
			}
			foreach my $false (@isfalse) {
				if (defined $config{$section}{$toggle} && $config{$section}{$toggle} eq $false) { $config{$section}{$toggle} = 0; }
			}
		}

		# section path is the section name, unless section path has been explicitly defined	
		if (defined ($ini{$section}{'path'})) { 
			$config{$section}{'path'} = $ini{$section}{'path'};
		} else {
			$config{$section}{'path'} = $section;
		}

		# how 'bout some recursion? =)
		my @datasets;
		if ($ini{$section}{'recursive'}) {
			@datasets = getchilddatasets($config{$section}{'path'});
			foreach my $dataset(@datasets) {
				chomp $dataset;
				foreach my $key (keys %{$config{$section}} ) {
					if (! ($key =~ /template|recursive|children_only/)) {
						if ($args{'debug'}) { print "DEBUG: recursively setting $key from $section to $dataset.\n"; }
						$config{$dataset}{$key} = $config{$section}{$key};
					}
				}
				$config{$dataset}{'path'} = $dataset;
				$config{$dataset}{'initialized'} = 1;
			}
		}



	}

	return %config;
} # end sub init

####################################################################################
####################################################################################
####################################################################################

sub get_date {
	my %datestamp;
	($datestamp{'sec'},$datestamp{'min'},$datestamp{'hour'},$datestamp{'mday'},$datestamp{'mon'},$datestamp{'year'},$datestamp{'wday'},$datestamp{'yday'},$datestamp{'isdst'}) = localtime(time);
	$datestamp{'year'} += 1900;
	$datestamp{'unix_time'} = (((((((($datestamp{'year'} - 1971) * 365) + $datestamp{'yday'}) * 24) + $datestamp{'hour'}) * 60) + $datestamp{'min'}) * 60) + $datestamp{'sec'};
	$datestamp{'sec'} = sprintf ("%02u", $datestamp{'sec'});
	$datestamp{'min'} = sprintf ("%02u", $datestamp{'min'});
	$datestamp{'hour'} = sprintf ("%02u", $datestamp{'hour'});
	$datestamp{'mday'} = sprintf ("%02u", $datestamp{'mday'});
	$datestamp{'mon'} = sprintf ("%02u", ($datestamp{'mon'} + 1));
	$datestamp{'noseconds'} = "$datestamp{'year'}-$datestamp{'mon'}-$datestamp{'mday'}_$datestamp{'hour'}:$datestamp{'min'}";
	$datestamp{'sortable'} = "$datestamp{'noseconds'}:$datestamp{'sec'}";
	return %datestamp;
}

####################################################################################
####################################################################################
####################################################################################


sub displaytime {
        # take a time in seconds, return it in human readable form
        my $elapsed = shift;

        my $days = int ($elapsed / 60 / 60 / 24);
        $elapsed -= $days * 60 * 60 * 24;
        my $hours = int ($elapsed / 60 / 60);
        $elapsed -= $hours * 60 * 60;
        my $minutes = int ($elapsed / 60);
        $elapsed -= $minutes * 60;
        my $seconds = int($elapsed);
        my $humanreadable;
        if ($days) { $humanreadable .= " $days" . 'd'; }
        if ($hours || $days) { $humanreadable .= " $hours" . 'h'; }
        if ($minutes || $hours || $days) { $humanreadable .= " $minutes" . 'm'; }
        $humanreadable .= " $seconds" . 's';
        $humanreadable =~ s/^ //;
        return $humanreadable;
}


####################################################################################
####################################################################################
####################################################################################

sub check_zpool() {
	# check_zfs Nagios plugin for monitoring Sun ZFS zpools
	# Copyright (c) 2007 
	# original Written by Nathan Butcher
	# adapted for use within Sanoid framework by Jim Salter (2014)
	#
	# Released under the GNU Public License
	#
	# This program is free software; you can redistribute it and/or modify
	# it under the terms of the GNU General Public License as published by
	# the Free Software Foundation; either version 2 of the License, or
	# (at your option) any later version.
	#
	# This program is distributed in the hope that it will be useful,
	# but WITHOUT ANY WARRANTY; without even the implied warranty of
	# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	# GNU General Public License for more details.
	#
	# You should have received a copy of the GNU General Public License
	# along with this program; if not, write to the Free Software
	# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
	
	# Version: 0.9.2
	# Date : 24th July 2007
	# This plugin has tested on FreeBSD 7.0-CURRENT and Solaris 10
	# With a bit of fondling, it could be expanded to recognize other OSes in
	# future (e.g. if FUSE Linux gets off the ground)
	
	# Verbose levels:-
	# 1 - Only alert us of zpool health and size stats
	# 2 - ...also alert us of failed devices when things go bad
	# 3 - ...alert us of the status of all devices regardless of health
	#
	# Usage:   check_zfs <zpool> <verbose level 1-3>
	# Example: check_zfs zeepool 1
	#	ZPOOL zeedata : ONLINE {Size:3.97G Used:183K Avail:3.97G Cap:0%}

	
	my %ERRORS=('DEPENDENT'=>4,'UNKNOWN'=>3,'OK'=>0,'WARNING'=>1,'CRITICAL'=>2);
	my $state="UNKNOWN";
	my $msg="FAILURE";
	
	my $pool=shift;
	my $verbose=shift;
	
	my $size="";
	my $used="";
	my $avail="";
	my $cap="";
	my $health="";
	my $dmge="";
	my $dedup="";
	
	if ($verbose < 1 || $verbose > 3) {
		print "Verbose levels range from 1-3\n";
		exit $ERRORS{$state};
	}
	
	my $statcommand="/sbin/zpool list -o name,size,cap,health,free $pool";
	
	if (! open STAT, "$statcommand|") {
		print ("$state '$statcommand' command returns no result! NOTE: This plugin needs OS support for ZFS, and execution with root privileges.\n");
		exit $ERRORS{$state};
	}

	# chuck the header line
	my $header = <STAT>;

	# find and parse the line with values for the pool	
	while(<STAT>) {
		chomp;
		if (/^${pool}\s+/) {
			my @row = split (/ +/);
			my $name;
			($name, $size, $cap, $health, $avail) = @row;
		}
	}
	
	# Tony: Debuging
	# print "Size: $size \t Used: $used \t Avai: $avail \t Cap: $cap \t Health: $health\n";
	
	close(STAT);
	
	## check for valid zpool list response from zpool
	if (! $health ) {
		$state = "CRITICAL";
		$msg = sprintf "ZPOOL {%s} does not exist and/or is not responding!\n", $pool;
		print $state, " ", $msg;
		exit ($ERRORS{$state});
	}
	
	## determine health of zpool and subsequent error status
	if ($health eq "ONLINE" ) {
		$state = "OK";
	} else {
		if ($health eq "DEGRADED") {
			$state = "WARNING";
		} else {
			$state = "CRITICAL";
		}
	}
	
	## get more detail on possible device failure
	## flag to detect section of zpool status involving our zpool
	my $poolfind=0;
	
	$statcommand="/sbin/zpool status $pool";
	if (! open STAT, "$statcommand|") {
		$state = 'CRITICAL';
		print ("$state '$statcommand' command returns no result! NOTE: This plugin needs OS support for ZFS, and execution with root privileges.\n");
		exit $ERRORS{$state};
	}
	
	## go through zfs status output to find zpool fses and devices
	while(<STAT>) {
		chomp;
	
		if (/^\s${pool}/ && $poolfind==1) {
			$poolfind=2;
			next;
		} elsif ( $poolfind==1 ) {
			$poolfind=0;
		}
	
		if (/NAME\s+STATE\s+READ\s+WRITE\s+CKSUM/) {
			$poolfind=1;
		}
	
		if ( /^$/ ) {
			$poolfind=0;
		}
	
		if ($poolfind == 2) {
	
			## special cases pertaining to full verbose
			if (/^\sspares/) {
				next unless $verbose == 3;
				$dmge=$dmge . "[SPARES]:- ";
				next;
			}
			if (/^\s{5}spare\s/) {
				next unless $verbose == 3;
				my ($sta) = /spare\s+(\S+)/;
				$dmge=$dmge . "[SPARE:${sta}]:- ";
				next;
			}
			if (/^\s{5}replacing\s/) {
				next unless $verbose == 3;
				my $perc;
				my ($sta) = /^\s+\S+\s+(\S+)/;
				if (/%/) {
					($perc) = /([0-9]+%)/;	
				} else {
					$perc = "working";
				}
				$dmge=$dmge . "[REPLACING:${sta} (${perc})]:- ";
				next;
			}
	
			## other cases
			my ($dev, $sta) = /^\s+(\S+)\s+(\S+)/;
	
			## pool online, not degraded thanks to dead/corrupted disk
			if ($state eq "OK" && $sta eq "UNAVAIL") {
				$state="WARNING";
	
				## switching to verbose level 2 to explain weirdness
				if ($verbose == 1) {
					$verbose =2;
				}
			}
	
			## no display for verbose level 1
			next if ($verbose==1);
			## don't display working devices for verbose level 2
			next if ($verbose==2 && $state eq "OK");
			next if ($verbose==2 && ($sta eq "ONLINE" || $sta eq "AVAIL" || $sta eq "INUSE"));
	
			## show everything else
			if (/^\s{3}(\S+)/) {
				$dmge=$dmge . "<" . $dev . ":" . $sta . "> ";
			} elsif (/^\s{7}(\S+)/) {
				$dmge=$dmge . "(" . $dev . ":" . $sta . ") ";
			} else {
				$dmge=$dmge . $dev . ":" . $sta . " ";
			}
		}
	}
	
	## calling all goats!
	
	$msg = sprintf "ZPOOL %s : %s {Size:%s Free:%s Cap:%s} %s\n", $pool, $health, $size, $avail, $cap, $dmge;
	$msg = "$state $msg";
	return ($ERRORS{$state},$msg);
} # end check_zpool()

######################################################################################################
######################################################################################################
######################################################################################################
######################################################################################################
######################################################################################################

sub checklock {
	# take argument $lockname. 
	#
	# read /var/run/$lockname.lock for a pid on first line and a mutex on second line.
	#
	# check process list to see if the pid from /var/run/$lockname.lock is still active with
	# the original mutex found in /var/run/$lockname.lock.
	#
	# return:
	#    0 if lock is present and valid for another process
	#    1 if no lock is present
	#    2 if lock is present, but we own the lock
	#
	# shorthand - any true return indicates we are clear to lock; a false return indicates
	#             that somebody else already has the lock and therefore we cannot.
	#             

	my $lockname = shift;
	my $lockfile = "/var/run/$lockname.lock";
	
	if (! -e $lockfile) {
		# no lockfile
		return 1;
	}

	# lockfile exists. read pid and mutex from it. see if it's our pid.  if not, see if 
	# there's still a process running with that pid and with the same mutex.
	
	open FH, "< $lockfile";
	my @lock = <FH>;
	close FH;

	my $lockmutex = pop(@lock);
	my $lockpid = pop(@lock);

	chomp $lockmutex;
	chomp $lockpid;

	if ($lockpid == $$) {
		# we own the lockfile. no need to check any further.
		return 2;
	}

	open PL, "$pscmd -p $lockpid -o args= |";
	my @processlist = <PL>;
	close PL;

	my $checkmutex = pop(@processlist);
	chomp $checkmutex;

	if ($checkmutex eq $lockmutex) {
		# lock exists, is valid, is not owned by us - return false
		return 0;
	} else {
		# lock is present but not valid - remove and return true
		unlink $lockfile;
		return 1;
	}
}

sub removelock {
	# take argument $lockname.
	#
	# make sure /var/run/$lockname.lock actually belongs to me (contains my pid and mutex)
	# and remove it if it does, die if it doesn't.

	my $lockname = shift;
	my $lockfile = "/var/run/$lockname.lock";

	if (checklock($lockname) == 2) {
		unlink $lockfile;
		return;
	} elsif (checklock($lockname) == 1) {
		die "ERROR: No valid lockfile found - Did a rogue process or user update or delete it?\n";
	} else {
		die "ERROR: A valid lockfile exists but does not belong to me! I refuse to remove it.\n";
	}
}

sub writelock {
	# take argument $lockname.
	#
	# write a lockfile to /var/run/$lockname.lock with first line
	# being my pid and second line being my mutex.

	my $lockname = shift;
	my $lockfile = "/var/run/$lockname.lock";

	# die honorably rather than overwriting a valid, existing lock
	if (! checklock($lockname)) {
		die "ERROR: Valid lock already exists - I refuse to overwrite it. Committing seppuku now.\n";
	}

	my $pid = $$;
	
	open PL, "$pscmd -p $$ -o args= |";
	my @processlist = <PL>;
	close PL;
	
	my $mutex = pop(@processlist);
	chomp $mutex;
	
	open FH, "> $lockfile";
	print FH "$pid\n";
	print FH "$mutex\n";
	close FH;
}

sub iszfsbusy {
	# check to see if ZFS filesystem passed in as argument currently has a zfs send or zfs receive process referencing it.
	# return true if busy (currently being sent or received), return false if not.

        my $fs = shift;
        # if (args{'debug'}) { print "DEBUG: checking to see if $fs on is already in zfs receive using $pscmd -Ao args= ...\n"; }

        open PL, "$pscmd -Ao args= |";
        my @processes = <PL>;
        close PL;

        foreach my $process (@processes) {
		# if ($args{'debug'}) { print "DEBUG: checking process $process...\n"; }
                if ($process =~ /zfs *(send|receive|recv).*$fs/) {
                        # there's already a zfs send/receive process for our target filesystem - return true
                        # if ($args{'debug'}) { print "DEBUG: process $process matches target $fs!\n"; }
                        return 1;
                }
        }

        # no zfs receive processes for our target filesystem found - return false
        return 0;
}

#######################################################################################################################3
#######################################################################################################################3
#######################################################################################################################3

sub getchilddatasets {
	# for later, if we make sanoid itself support sudo use
	my $fs = shift;
	my $mysudocmd = '';

	my $getchildrencmd = "$mysudocmd $zfs list -o name -Hr $fs |";
	 if ($args{'debug'}) { print "DEBUG: getting list of child datasets on $fs using $getchildrencmd...\n"; }
	open FH, $getchildrencmd;
	my @children = <FH>;
	close FH;

	return @children;
}

__END__

=head1 NAME

sanoid - ZFS snapshot management and replication tool

=head1 SYNOPSIS

sanoid [options]

Options:
  --configdir=DIR       Specify a directory to find config file sanoid.conf

  --cron                Creates snapshots and purges expired snapshots
  --readonly            Simulates creation/deletion of snapshots
  --quiet               Suppresses non-error output
  --force-update        Clears out sanoid's zfs snapshot cache

  --monitor-health      Reports on zpool "health", in a Nagios compatible format
  --monitor-snapshots   Reports on snapshot "health", in a Nagios compatible format
  --take-snapshots      Creates snapshots as specified in sanoid.conf
  --prune-snapshots     Purges expired snapshots as specified in sanoid.conf

  --help                Prints this helptext
  --verbose             Prints the version number
  --debug               Prints out a lot of additional information during a sanoid run