#! /usr/bin/perl -w
# fixscript will replace this line with code to load INN::Config

#  Copyright Andreas Lamrecht 1998
#  <Andreas.Lamprect@siemens.at>
#
#  Modified by Kjetil T. Homme 1998, 2000
#  <kjetilho@ifi.uio.no>
#
#  Modified by Robert R. Collier 1998
#  <rob@lspace.org>
#
#  bigint support added by Duane Currie (sandman@hub.org) 1998

use strict;
use Getopt::Long;
use Math::BigInt;
use Math::BigFloat;
use English;

my $conffile = "$INN::Config::pathetc/cycbuff.conf";
my $storageconf = "$INN::Config::pathetc/storage.conf";
my $lastconftime = 0;

sub usage {
    print <<"_end_";
Summary tool for CNFS

Usage:
	$0 [-ahpPsv] [-c class] [-i seconds] [-l [seconds]] [-m buffer]

	If called without args, does a one-time status of all CNFS buffers
	-a:           print the age of the oldest article in the cycbuff
	-c class:     print out status of CNFS buffers in that class
	-h:           this information
	-i seconds:   initial sleep of that many seconds at startup
	-l [seconds]: loop like vmstat, default seconds = 600
	-m buffer:    print out information suitable for MRTG
	-p:           print out an MRTG config file
	-P:           write PID into $INN::Config::pathrun/cnfsstat.pid
	-s:           log through syslog
	-v:           do consistency checks and print the result
_end_
    exit(1);
}

my (%class, %buff, %stor, @storsort);
my (%prevclass, %prevbuff, %prevstor, @prevstorsort);

my @buffers;

my ($oclass, $obuffer);
my %opt = (c=>\$oclass, m=>\$obuffer);
Getopt::Long::config('no_ignore_case');
GetOptions(\%opt,
           "-a", "-c=s", "-h", "-i=i", "-l:i", "-m=s",
           "-p", "-P", "-s", "-v");

usage() if $opt{'h'};

my $use_syslog = 0;
if ($opt{'s'}) {
    eval { require Sys::Syslog; import Sys::Syslog; $use_syslog = 1 };
    if ($use_syslog) {
        if ($Sys::Syslog::VERSION lt 0.15) {
            eval "sub Sys::Syslog::_PATH_LOG { '/dev/log' }" if $^O eq 'dec_osf';
            Sys::Syslog::setlogsock('unix') if $^O =~ /linux|dec_osf|freebsd|darwin/;
        }
	openlog('cnfsstat', 'pid', $INN::Config::syslog_facility);
    } else {
	print STDERR "Syslog is not available.  -s option is ignored.\n";
    }
}

if ($opt{'P'}) {
    if (open my $FILE, '>', "$INN::Config::pathrun/cnfsstat.pid") {
	print $FILE "$$\n";
	close $FILE;
    };
}

my $sleeptime = (defined($opt{'l'}) && $opt{'l'} > 0) ? $opt{'l'} : 600;

unless (read_cycbuffconf()) {
    print STDERR "Invalid $conffile file.\n";
    exit (1);
}

unless (read_storageconf()) {
    print STDERR "Invalid $storageconf file.\n";
    exit (1);
}


mrtg($obuffer) if $obuffer;
mrtg_config() if $opt{'p'};

# Initial sleep, before starting the work.
if(defined($opt{'i'}) && $opt{'i'} > 0) {
    sleep($opt{'i'});
    if (!$use_syslog) {
        print STDOUT "$opt{'i'} seconds later:\n";
    }
}


START:

# Check whether the configuration files need reloading.
my $cycbufftime = (stat($conffile))[9] if (-r $conffile);
my $storagetime = (stat($storageconf))[9] if (-r $storageconf);
my $maxtime = ($cycbufftime < $storagetime) ? $storagetime : $cycbufftime;

# Set $lastconftime for the first run of the comparison.
$lastconftime = $maxtime if not $lastconftime;

if ($lastconftime < $maxtime) {
    my $reloadok = 1;

    $lastconftime = $maxtime;

    # Save the previous configuration, in case reloading it fails.
    # Direct copies of the arrays and hashes works fine here.
    %prevclass = %class; undef %class;
    %prevbuff = %buff; undef %buff;
    %prevstor = %stor; undef %stor;
    @prevstorsort = @storsort; undef @storsort;

    unless (read_cycbuffconf()) {
        print STDERR "Invalid $conffile file.\n";
        $reloadok = 0;
    }

    unless (read_storageconf()) {
        print STDERR "Invalid $storageconf file.\n";
        $reloadok = 0;
    }

    # In case reloading configuration files fails, restore the
    # previous known configuration for this run of cnfsstat.
    if (!$reloadok) {
        %class = %prevclass;
        %buff = %prevbuff;
        %stor = %prevstor;
        @storsort = @prevstorsort;
    }
}

my $logline;
my $header_printed = 0;
my ($gr, $cl, $min, $max);
if ($oclass) {
    if ($class{$oclass}) {
	if (!$header_printed) {
            if ($stor{$oclass}) {
                ($gr, $cl, $min, $max) = split(/:/, $stor{$oclass});
            } else {
                ($gr, $cl, $min, $max) = ('', $oclass, 0, 0);
            }
            # Remove leading and trailing double quotes, if present.
            $gr =~ s/"?([^"]*)"?/$1/g;
	    if ($use_syslog) {
		if ($min || $max) {
		    $logline = sprintf("Class %s for groups matching \"%s\" article size min/max: %d/%d", $oclass, $gr, $min, $max);
		} else {
		    $logline = sprintf("Class %s for groups matching \"%s\"", $oclass, $gr);
		}
	    } else {
		print STDOUT "Class $oclass";
		print STDOUT " for groups matching \"$gr\"";
		if ($min || $max) {
		    print STDOUT ", article size min/max: $min/$max";
		}
		print STDOUT "\n";
	    }
	    $header_printed = 1;
	}
	
	@buffers = split(/,/, $class{$oclass});
	if (! @buffers) {
	    print STDERR "No buffers in Class $oclass ...\n";
	    next;
	}
	
	foreach my $b (@buffers) {
	    if (! $buff{$b} ) {
		print STDERR "No buffer definition for buffer $b ...\n";
		next;
	    }
	    print_cycbuff_head($buff{$b});
	}
    } else {
	print STDERR "Class $oclass not found ...\n";
    }
} else { # Print all Classes
    my %buffDone;
    foreach my $c (@storsort) {
	($gr, $cl, $min, $max) = split(/:/, $stor{$c});
        # Remove leading and trailing double quotes, if present.
        $gr =~ s/"?([^"]*)"?/$1/g;
	if ($use_syslog) {
	    if ($min || $max) {
		$logline = sprintf("Class %s for groups matching \"%s\" article size min/max: %d/%d", $c, $gr, $min, $max);
	    } else {
		$logline = sprintf("Class %s for groups matching \"%s\"", $c, $gr);
	    }
	} else {
	    print STDOUT "Class $c";
	    print STDOUT " for groups matching \"$gr\"";
	    if($min || $max) {
		print STDOUT ", article size min/max: $min/$max";
	    }
	    print STDOUT "\n";
	}
	@buffers = split(/,/, $class{$c});
	if(! @buffers) {
	    print STDERR "No buffers in Class $c ...\n";
	    next;
	}
	
	foreach my $b (@buffers) {
	    if(! $buff{$b} ) {
		print STDERR "No buffer definition for buffer $b ...\n";
		next;
	    }
	    print_cycbuff_head($buff{$b});
            $buffDone{$b}++;
	}
	if (!$use_syslog) {
	    print STDOUT "\n";
	}
    }

    if (!$use_syslog) {
        # Finally, print all retired cyclic buffers, still active but no longer
        # mentioned in a class.
        my $buffRetired = 0;
        foreach my $b (sort keys(%buff)) {
            if(! exists($buffDone{$b})) {
                if (!$buffRetired) {
                    print STDOUT "Retired cyclic buffers\n";
                }
                print_cycbuff_head($buff{$b});
                $buffRetired++;
            }
        }
    }
}

if(defined($opt{'l'})) {
    sleep($sleeptime);
    if (!$use_syslog) {
	print STDOUT "$sleeptime seconds later:\n";
    }
    goto START;
}

sub read_cycbuffconf {
    my @line;
    return 0 unless open my $CONFFILE, '<', $conffile;

    while(<$CONFFILE>) {
	$_ =~ s/^\s*(.*?)\s*$/$1/;
	# Here we handle continuation lines
	while (m/\\$/) {
	    my $contline = <$CONFFILE>;
	    $contline =~ s/^\s*(.*?)\s*$/$1/;
	    chop;
	    $_ .= $contline;
	}
	# \x23 below is #.  Emacs perl-mode gets confused by the "comment"
	next if ($_ =~ /^\s*$/ || $_ =~ /^\x23/);
	next if ($_ =~ /^cycbuffupdate:/ || $_ =~ /^refreshinterval:/);
	
	if($_ =~ /^metacycbuff:/) {
	    @line = split(/:/, $_);
	    if ($class{$line[1]}) {
		print STDERR "Class $line[1] more than one time in CycBuff Conffile $conffile ...\n";
		return 0;
	    }

	    $class{$line[1]} = $line[2];
	    next;
	}

	if ($_ =~ /^cycbuff/) {
	    @line = split(/:/, $_);
	    if ($buff{$line[1]}) {
		print STDERR "Buff $line[1] more than one time in CycBuff Conffile $conffile ...\n";
		return 0;
	    }
	    $buff{$line[1]} = $line[2];
	    next;
	}

	print STDERR "Unknown config line \"$_\" in CycBuff Conffile $conffile ...\n";
        return 0;
    }
    close $CONFFILE;
    return 1;
}

sub read_storageconf {
    my $line = 0;
    return 0 unless open my $STOR, '<', $storageconf;

    while (<$STOR>) {
	++$line;
	next if /^\s*#/;

	# defaults
	my %key = ("NEWSGROUPS" => "*",
		    "SIZE" => "0,0");
		
	if (/method\s+cnfs\s+\{/) {
	    while (<$STOR>) {
		++$line;
		next if /^\s*#/;
		last if /\}/;
		if (/(\w+):\s+(\S+)/i) {
		    $key{uc($1)} = $2;
		}
	    }
	    unless (defined $key{'CLASS'} && defined $key{'OPTIONS'}) {
		print STDERR "storage.conf:$line: ".
			"Missing 'class' or 'options'\n";
		return 0;
	    }

	    $key{'SIZE'} .= ",0" unless $key{'SIZE'} =~ /,/;
	    $key{'SIZE'} =~ s/,/:/;

	    if (!defined $stor{$key{'OPTIONS'}}) {
		$stor{$key{'OPTIONS'}} = "$key{'NEWSGROUPS'}:$key{'CLASS'}:" .
			"$key{'SIZE'}:$key{'OPTIONS'}";
		push(@storsort, $key{'OPTIONS'});
	    }
	}
    }
    return 1;
}

sub print_cycbuff_head {
    my ($buffpath) = @_;
    my ($name, $len, $free, $update, $cyclenum, $oldart) =
	    get_cycbuff_info($buffpath);

    if ($use_syslog) {
	($name) = split(/\s/, $name);
	$name =~ s/\0//g;
	# Log only if the buffer is initialized (cyclenum is not -1).
	syslog ('notice', '%s Buffer %s, len: %.2f  Mbytes, used: %.2f Mbytes (%4.1f%%) %3d cycles',
		$logline, $name, Math::BigFloat->new($len) / (1024 * 1024),
		Math::BigFloat->new($free) / (1024 * 1024),
		100 * Math::BigFloat->new($free) / Math::BigFloat->new($len),
		$cyclenum) if $cyclenum >= 0;
	return 0;
    }

    $name =~ s/\0//g;
    print " Buffer $name, size: ", human_readable($len, 4);
    print ", position: ", human_readable($free, 4);
    printf "  %.2f cycles\n", $cyclenum + Math::BigFloat->new($free) / Math::BigFloat->new($len);

    # The CNFS buffer may not have been initialized yet or received an article.
    # Take it into account because $oldart may be undefined.
    my ($when, $ago) = make_time($update);
    if (defined $oldart or not $opt{'a'}) {
        print "  Newest: $when, $ago ago\n";
    } else {
        print "  Created: $when, $ago ago\n";
    }

    if ($opt{'a'}) {
        if (defined $oldart) {
            my ($when, $ago) = make_time($oldart);
            print "  Oldest: $when, $ago ago\n";
        } else {
            print "  No oldest article\n";
        }
    }
    return;
}

sub make_time {
    my ($t) = @_;
    my (@ret);

    my ($sec,$min,$hour,$mday,$mon,$year) =
	    (localtime($t))[0..5];
    push (@ret, sprintf("%04d-%02d-%02d %2d:%02d:%02d",
			$year + 1900, $mon + 1, $mday, $hour, $min, $sec));
    $t = time - $t;

    $mday = int($t/86400); $t = $t % 86400;
    $hour = int($t/3600);  $t = $t % 3600;
    $min  = int($t/60);    $t = $t % 60;

    push (@ret, sprintf("%4d days, %2d:%02d:%02d",
			$mday, $hour, $min, $t));
    return @ret;
}

sub human_readable {
    my ($val, $digits) = @_;
    $val =~ s/\+//;

    my @name = ("kBytes", "MBytes", "GBytes", "TBytes");
    my $base = 1024;
    my $factor = 1024;

    my $unit = -1;
    my $oldscaled = Math::BigFloat->new($val) / $base;
    my $scaled = $oldscaled;
    while ( ( int($scaled) > 0 ) && ( $unit < $#name ) ) {
	$oldscaled = $scaled;
	$scaled /= $factor;
	$unit++;
    }
    $scaled = $oldscaled;
    my $predigits = length (int($scaled));
    my $postdigits = $digits - $predigits - 1;
    $postdigits = 0 if $postdigits < 0;
    ++$digits;

    return sprintf ("%${digits}.${postdigits}f %s", $scaled, $name[$unit]);
}

sub mrtg {
	my $buffer = shift;
	# print "Buffer = $buff{$buffer}\n";
	my @info = get_cycbuff_info($buff{$buffer});
	print "$info[1]\n";
	print "$info[2]\n";
	print "$info[4]\n";
	print "$info[0]\n";
	exit(0);
}

sub mrtg_config {
	print "Sub MRTG-CONFIG\n";
	foreach my $class (sort(keys(%class))) {
		print "##\n## Class  : $class\n## Wildmat: $stor{$class}\n##\n\n";
		foreach my $buffer (split /\,/, $class{$class}) {
			mrtg_buffer($class, $buffer);
		}
	}
	exit(0);
}

sub mrtg_buffer {
	my ($class,$buffer) = @_;
	#my ($name, $num, $buff, $size) = @_;
        my $tag = 'cnfs-' . $buffer;

        print 'Target[', $tag, ']: `', "$INN::Config::pathbin/cnfsstat -m ", $buffer, '`', "\n";
        print 'MaxBytes[', $tag, ']: ', (get_cycbuff_info($buff{$buffer}))[1], "\n";
        print 'Title[', $tag, ']: ', "${buffer} Usage\n";
        print 'Options[', $tag, ']: growright gauge', "\n";
        print 'YLegend[', $tag, ']: ', "${buffer}\n";
        print 'ShortLegend[', $tag, ']: MB', "\n";
        print 'PageTop[', $tag, ']: ', "<H1>Usage of ${buffer}</H1>\n";
	print "<BR><TT>$stor{$class}</TT>\n";
        print "\n";
        return 1;
}

sub bigsysseek {
    my ($handle, $offset) = @_;

    # $offset may be a bigint; and have a value that doesn't fit in a signed long.
    # Even with largefiles enabled, perl will still truncate the argument to lseek64
    # to 32 bits.  So we seek multiple times, <2G at a time.

    if ($offset > 2147483647) {
	# Since perl truncates the return value of lseek64 to 32 bits, it might
	# see a successful return value as negative, and return FALSE (undef).
	# So we must ignore the return value of sysseek and assume that it worked.

	seek($handle, 0, 0);
	while ($offset > 2000000000) {
	    sysseek($handle, 2000000000, 1) || return 0;
	    $offset -= 2000000000;
	}
	sysseek($handle, $offset, 1) || return 0;
	return 1;
    } else {
	return sysseek($handle, $offset, 0);
    }
}

sub check_read_return {
  my $result = shift;
  die "read: $!\n" unless defined($result);
  die "read reached eof\n" unless $result;
  return $result;
}

sub get_cycbuff_info {
    my ($buffpath) = @_;
    my $oldart;

    my $CNFSMASIZ = 8;
    my $CNFSNASIZ = 16;
    my $CNFSPASIZ = 64;
    my $CNFSLASIZ = 16;
    my $headerlength = 2 * $CNFSMASIZ + 2 * $CNFSNASIZ + $CNFSPASIZ + (6 * $CNFSLASIZ);

    my ($BUFF, $buff);

    if ( !open $BUFF, '<', $buffpath ) {
	print STDERR "Cannot open Cycbuff $buffpath ...\n";
	exit(1);
    }

    $buff = "";
    if ( !read $BUFF, $buff, $headerlength ) {
	print STDERR "Cannot read $headerlength bytes from file $buffpath...\n";
	exit(1);
    }

    my ($magic, $name, $path, $lena, $freea, $updatea, $cyclenuma, $metaname,
     $orderinmeta, $currentbuff, $blksza) =
           unpack("a8 a16 a64 a16 a16 a16 a16 a16 a16 a8 a16", $buff);

    if (!$magic) {
	print STDERR "Error while unpacking header ...\n";
	exit(1);
    }

    my $len = bhex($lena);
    my $free = bhex($freea);
    my $update = hex($updatea);
    my $cyclenum = hex($cyclenuma) - 1;
    my $blksz = ($magic =~ m/^CBuf4/) ? hex($blksza) : 512;

    if ($opt{'a'}) {

	my $pagesize = 16384;
	my $minartoffset = int($len / ($blksz * 8)) + 512;
	# Align upwards:
	$minartoffset = ($minartoffset + $pagesize) & ~($pagesize - 1);
	
	if ($cyclenum == 0 && $free == $minartoffset) {
	    # The cycbuff has no articles yet.
	    goto done;
	}

	# Don't loop endlessly, set rough upper bound
	my $sentinel = $cyclenum == 0 ? $free : $len;
	my $offset = $cyclenum == 0 ? $minartoffset : $free + $pagesize;

	bigsysseek($BUFF, $offset) || die "sysseek: $!\n";
	check_read_return (sysread ($BUFF, $buff, $pagesize));
	do {
            my $chunk;
	    check_read_return (sysread ($BUFF, $chunk, $pagesize));

	    $buff .= $chunk;
	    while ($buff =~ /^message-id:\s+(<.*?>)/mi) {
		$buff = $POSTMATCH;
		$oldart = lookup_age($1);
		next unless $oldart;
		
		# Is the article newer than the last update of the cycbuff?
		if ($oldart >= $update) {
		    $update = $oldart;
		} elsif ($oldart < $update - 60) {
		    goto done;
		}
	    }
	    # Just in case we chopped Message-ID in two, use the end
	    # at the front in next iteration.
	    $buff = substr ($buff, -$blksz);

	} while ($sentinel -= $pagesize > 0);
    }

done:
    close $BUFF;
    return($name,$len,$free,$update,$cyclenum,$oldart);
}

sub lookup_age {
    my ($msgid) = @_;

    my $history = safe_run("$INN::Config::newsbin/grephistory", "-l", $msgid);
    if ($history =~ /\t(\d+)~/) {
	return $1;
    }

    if ($opt{'v'}) {
        print "   (Missing $msgid)\n";
    }

    return 0;
}

sub safe_run {
    my $output = "";

    my $pid = open my $KID_TO_READ, "-|";
    die "fork: $!\n" unless defined $pid;
    if ($pid) {
	while (<$KID_TO_READ>) {
	    $output .= $_;
	}
	close $KID_TO_READ;
    } else {
	exec(@_) || die "can't exec $_[0]: $!";
	# NOTREACHED
    }
    return $output;
}

# Hex to bigint conversion routine.
# bhex(HEXSTRING) returns BIGINT (with leading + chopped off).
#
# In most languages, unlimited size integers are done using string math
# libraries usually called bigint.  (Java, Perl, etc.)
#
# Bigint's are really just strings.

sub bhex {
    my $hexValue = shift;
    $hexValue =~ s/^0x//;

    my $integerValue = Math::BigInt->new('0');
    for (my $i = 0; $i < length($hexValue); $i += 2) {
        # Could be more efficient going at larger increments, but byte
        # by byte is safer for the case of 9 byte values, 11 bytes, etc.

        my $byte = substr($hexValue, $i, 2);
        my $byteIntValue = hex($byte);

        # bmuladd() is only in Perl >= 5.10.0.
        $integerValue->bmul('256');
        $integerValue->badd("$byteIntValue");
    }

    my $result = $integerValue->bstr();
    $result =~ s/^\+//;
    return $result;
}