#!/usr/bin/perl
#============================================================= -*-perl-*-
#
# BackupPC_dump: Dump a single client.
#
# DESCRIPTION
#
#   Usage: BackupPC_dump [-i] [-f] [-F] [-I] [-d] [-e] [-v] <client>
#
#   Flags:
#
#     -i   Do an incremental dump, overriding any scheduling (but a full
#          dump will be done if no dumps have yet succeeded)
#
#     -f   Do a full dump, overriding any scheduling.
#
#     -I   Do an increment dump if the regular schedule requires a
#          full or incremental, otherwise do nothing (a full is done
#          if no dumps have yet succeeded)
#
#     -F   Do a full dump if the regular schedule requires a
#          full or incremental, otherwise do nothing
#
#     -d   Host is a DHCP pool address, and the client argument
#          just an IP address.  We lookup the NetBios name from
#          the IP address.
#
#     -e   Just do an dump expiry check for the client.  Don't do anything
#          else.  This is used periodically by BackupPC to make sure that
#          dhcp hosts have correctly expired old backups.  Without this,
#          dhcp hosts that are no longer on the network will not expire
#          old backups.
#
#     -v   verbose.  for manual usage: prints failure reasons in more detail.
#
#   BackupPC_dump is run periodically by BackupPC to backup $client.
#   The file $TopDir/pc/$client/backups is read to decide whether a
#   full or incremental backup needs to be run.  If no backup is
#   scheduled, or a ping to $client fails, then BackupPC_dump quits.
#
#   The backup is done using the selected XferMethod (smb, tar, rsync,
#   backuppcd etc), extracting the dump into $TopDir/pc/$client/new.
#   The xfer output is put into $TopDir/pc/$client/XferLOG.
#
#   If the dump succeeds (based on parsing the output of the XferMethod):
#     - $TopDir/pc/$client/new is renamed to $TopDir/pc/$client/nnn, where
#           nnn is the next sequential dump number.
#     - $TopDir/pc/$client/XferLOG is renamed to $TopDir/pc/$client/XferLOG.nnn.
#     - $TopDir/pc/$client/backups is updated.
#
#   If the dump fails:
#     - $TopDir/pc/$client/new is moved to $TopDir/trash for later removal.
#     - $TopDir/pc/$client/XferLOG is renamed to $TopDir/pc/$client/XferLOG.bad
#           for later viewing.
#
#   BackupPC_dump communicates to BackupPC via printing to STDOUT.
#
# AUTHOR
#   Craig Barratt  <cbarratt@users.sourceforge.net>
#
# COPYRIGHT
#   Copyright (C) 2001-2015  Craig Barratt
#
#   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 3.3.1, released 11 Jan 2015.
#
# See http://backuppc.sourceforge.net.
#
#========================================================================

use strict;
no  utf8;
use lib "__INSTALLDIR__/lib";
use BackupPC::Lib;
use BackupPC::FileZIO;
use BackupPC::Storage;
use BackupPC::Xfer;
use Encode;
use Socket;
use File::Path;
use File::Find;
use Getopt::Std;

###########################################################################
# Initialize
###########################################################################

die("BackupPC::Lib->new failed\n") if ( !(my $bpc = BackupPC::Lib->new) );
my $TopDir = $bpc->TopDir();
my $BinDir = $bpc->BinDir();
my %Conf   = $bpc->Conf();
my $NeedPostCmd;
my $Hosts;
my $SigName;
my $Abort;

$bpc->ChildInit();

my %opts;
if ( !getopts("defivFI", \%opts) || @ARGV != 1 ) {
    print("usage: $0 [-d] [-e] [-f] [-i] [-F] [-I] [-v] <client>\n");
    exit(1);
}
if ( $ARGV[0] !~ /^([\w\.\s-]+)$/ ) {
    print("$0: bad client name '$ARGV[0]'\n");
    exit(1);
}
if ( (defined($opts{f}) + defined($opts{i}) + defined($opts{F}) + defined($opts{I})) > 1 ) {
    print("$0: exiting because you can only use one of -f, -i, -F, and -I\n");
    exit(1);
}

my $client = $1;   # BackupPC's client name (might not be real host name)
my $hostIP;        # this is the IP address
my $host;          # this is the real host name

my($clientURI, $user);

$bpc->verbose(1) if ( $opts{v} );

if ( $opts{d} ) {
    #
    # The client name $client is simply a DHCP address.  We need to check
    # if there is any machine at this address, and if so, get the actual
    # host name via NetBios using nmblookup.
    #
    $hostIP = $client;
    if ( $bpc->CheckHostAlive($hostIP) < 0 ) {
	print(STDERR "Exiting because CheckHostAlive($hostIP) failed\n")
			    if ( $opts{v} );
	exit(1);
    }
    if ( $Conf{NmbLookupCmd} eq "" ) {
	print(STDERR "Exiting because \$Conf{NmbLookupCmd} is empty\n")
			    if ( $opts{v} );
	exit(1);
    }
    ($client, $user) = $bpc->NetBiosInfoGet($hostIP);
    if ( $client !~ /^([\w\.\s-]+)$/ ) {
	print(STDERR "Exiting because NetBiosInfoGet($hostIP) returned"
                   . " '$client', an invalid host name\n") if ( $opts{v} );
	exit(1)
    }
    $Hosts = $bpc->HostInfoRead($client);
    $host = $client;
} else {
    $Hosts = $bpc->HostInfoRead($client);
}
if ( !defined($Hosts->{$client}) ) {
    print(STDERR "Exiting because host $client does not exist in the"
               . " hosts file\n") if ( $opts{v} );
    exit(1)
}

my $Dir     = "$TopDir/pc/$client";
my @xferPid = ();
my $tarPid  = -1;
my $completionPercent;

#
# Re-read config file, so we can include the PC-specific config
#
$clientURI = $bpc->uriEsc($client);
if ( defined(my $error = $bpc->ConfigRead($client)) ) {
    print("dump failed: Can't read PC's config file: $error\n");
    exit(1);
}
%Conf = $bpc->Conf();

#
# Catch various signals
#
$SIG{INT}  = \&catch_signal;
$SIG{ALRM} = \&catch_signal;
$SIG{TERM} = \&catch_signal;
$SIG{PIPE} = \&catch_signal;
$SIG{STOP} = \&catch_signal;
$SIG{TSTP} = \&catch_signal;
$SIG{TTIN} = \&catch_signal;
my $Pid = $$;

#
# Make sure we eventually timeout if there is no activity from
# the data transport program.
#
alarm($Conf{ClientTimeout});

mkpath($Dir, 0, 0777) if ( !-d $Dir );
if ( !-f "$Dir/LOCK" ) {
    open(LOCK, ">", "$Dir/LOCK") && close(LOCK);
}

my($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime(time);
my $logPath = sprintf("$Dir/LOG.%02d%04d", $mon + 1, $year + 1900);

if ( !-f $logPath ) {
    #
    # Compress and prune old log files
    #
    my $lastLog = $Conf{MaxOldPerPCLogFiles} - 1;
    foreach my $file ( $bpc->sortedPCLogFiles($client) ) {
        if ( $lastLog <= 0 ) {
            unlink($file);
            next;
        }
        $lastLog--;
        next if ( $file =~ /\.z$/ || !$Conf{CompressLevel} );
        BackupPC::FileZIO->compressCopy($file,
                                        "$file.z",
                                        undef,
                                        $Conf{CompressLevel}, 1);
    }
}

open(LOG, ">>", $logPath);
select(LOG); $| = 1; select(STDOUT);

#
# For the -e option we just expire backups and quit
#
if ( $opts{e} ) {
    BackupExpire($client);
    exit(0);
}

#
# For archive hosts we don't bother any further
#
if ($Conf{XferMethod} eq "archive" ) {
    print(STDERR "Exiting because the XferMethod is set to archive\n")
                if ( $opts{v} );
    exit(0);
}

###########################################################################
# Figure out what to do and do it
###########################################################################

#
# See if we should skip this host during a certain range
# of times.
#
my $err = $bpc->ServerConnect($Conf{ServerHost}, $Conf{ServerPort});
if ( $err ne "" ) {
    print("Can't connect to server ($err)\n");
    print(LOG $bpc->timeStamp, "Can't connect to server ($err)\n");
    exit(1);
}
my $reply = $bpc->ServerMesg("status host($clientURI)");
$reply = $1 if ( $reply =~ /(.*)/s );
my(%StatusHost);
eval($reply);
$bpc->ServerDisconnect();

#
# For DHCP tell BackupPC which host this is
#
if ( $opts{d} ) {
    if ( $StatusHost{activeJob} ) {
        # oops, something is already running for this host
	print(STDERR "Exiting because backup is already running for $client\n")
			if ( $opts{v} );
        exit(0);
    }
    print("DHCP $hostIP $clientURI\n");
}

my($needLink, @Backups, $type);
my($incrBaseTime, $incrBaseBkupNum, $incrBaseLevel, $incrLevel);
my $lastFullTime = 0;
my $lastIncrTime = 0;
my $partialIdx = -1;
my $partialNum;
my $partialFileCnt;
my $lastBkupNum;
my $lastPartial = 0;

#
# Maintain backward compatibility with $Conf{FullPeriod} == -1 or -2
# meaning disable backups
#
$Conf{BackupsDisable} = -$Conf{FullPeriod}
            if ( !$Conf{BackupsDisable} && $Conf{FullPeriod} < 0 );

if ( $Conf{BackupsDisable} == 1 && !$opts{f} && !$opts{i}
        || $Conf{BackupsDisable} == 2 ) {
    print(STDERR "Exiting because backups are disabled with"
       . " \$Conf{BackupsDisable} = $Conf{BackupsDisable}\n") if ( $opts{v} );
    #
    # Tell BackupPC to ignore old failed backups on hosts that
    # have backups disabled.
    #
    print("backups disabled\n")
		if ( defined($StatusHost{errorTime})
		     && $StatusHost{reason} ne "Reason_backup_done"
		     && time - $StatusHost{errorTime} > 4 * 24 * 3600 );
    NothingToDo($needLink);
}

if ( !$opts{i} && !$opts{f} && $Conf{BlackoutGoodCnt} >= 0
             && $StatusHost{aliveCnt} >= $Conf{BlackoutGoodCnt} ) {
    my($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime(time);
    my($currHours) = $hour + $min / 60 + $sec / 3600;
    my $blackout;

    foreach my $p ( @{$Conf{BlackoutPeriods}} ) {
        #
        # Allow blackout to span midnight (specified by hourBegin
        # being greater than hourEnd)
        #
        next if ( ref($p->{weekDays}) ne "ARRAY" 
                    || !defined($p->{hourBegin})
                    || !defined($p->{hourEnd})
                );
        my $matchWday = $wday;
        if ( $p->{hourBegin} > $p->{hourEnd} ) {
            $blackout = $p->{hourBegin} <= $currHours
                          || $currHours <= $p->{hourEnd};
            if ( $currHours <= $p->{hourEnd} ) {
                #
                # This is after midnight, so decrement the weekday for the
                # weekday check (eg: Monday 11pm-1am means Monday 2300 to
                # Tuesday 0100, not Monday 2300-2400 plus Monday 0000-0100).
                #
                $matchWday--;
                $matchWday += 7 if ( $matchWday < 0 );
            }
        } else {
            $blackout = $p->{hourBegin} <= $currHours
                          && $currHours <= $p->{hourEnd};
        }
        if ( $blackout && grep($_ == $matchWday, @{$p->{weekDays}}) ) {
#           print(LOG $bpc->timeStamp, "skipping because of blackout"
#                      . " (alive $StatusHost{aliveCnt} times)\n");
            print(STDERR "Skipping $client because of blackout\n")
                            if ( $opts{v} );
            NothingToDo($needLink);
        }
    }
}

if ( !$opts{i} && !$opts{f} && $StatusHost{backoffTime} > time ) {
    printf(LOG "%sskipping because of user requested delay (%.1f hours left)\n",
                $bpc->timeStamp, ($StatusHost{backoffTime} - time) / 3600);
    NothingToDo($needLink);
}

#
# Now see if there are any old backups we should delete
#
BackupExpire($client);

my(@lastIdxByLevel, $incrCntSinceFull);

#
# Read Backup information, and find times of the most recent full and
# incremental backups.  Also figure out which backup we will use
# as a starting point for an incremental.
#
@Backups = $bpc->BackupInfoRead($client);
for ( my $i = 0 ; $i < @Backups ; $i++ ) {
    $needLink = 1 if ( $Backups[$i]{nFilesNew} eq ""
                        || -f "$Dir/NewFileList.$Backups[$i]{num}" );
    if ( $Backups[$i]{type} eq "full" ) {
        $incrCntSinceFull = 0;
        $lastBkupNum = $Backups[$i]{num};
        $lastIdxByLevel[0] = $i;
	if ( $lastFullTime < $Backups[$i]{startTime} ) {
	    $lastFullTime = $Backups[$i]{startTime};
	}
    } elsif ( $Backups[$i]{type} eq "incr" ) {
        $incrCntSinceFull++;
        $lastBkupNum = $Backups[$i]{num};
        $lastIdxByLevel[$Backups[$i]{level}] = $i;
        $lastIncrTime = $Backups[$i]{startTime}
                if ( $lastIncrTime < $Backups[$i]{startTime} );
    } elsif ( $Backups[$i]{type} eq "partial" ) {
        $partialIdx     = $i;
        $lastPartial    = $Backups[$i]{startTime};
        $partialNum     = $Backups[$i]{num};
        $partialFileCnt = $Backups[$i]{nFiles};
    }
}

#
# Decide whether we do nothing, or a full or incremental backup.
#
my $needs_full = (time - $lastFullTime > $Conf{FullPeriod} * 24 * 3600
               && time - $lastIncrTime > $Conf{IncrPeriod} * 24 * 3600);
my $needs_incr = (time - $lastIncrTime > $Conf{IncrPeriod} * 24 * 3600
               && time - $lastFullTime > $Conf{IncrPeriod} * 24 * 3600);

if ( $lastFullTime == 0
        || $opts{f}
        || (!$opts{i} && !$opts{I} && $needs_full)
        || ( $opts{F} && $needs_incr) ) {
    $type = "full";
    $incrLevel = 0;
    $incrBaseBkupNum = $lastBkupNum;
} elsif ( $opts{i}
        || $needs_incr
        || ($opts{I} && $needs_full) ) {
    $type = "incr";
    #
    # For an incremental backup, figure out which level we should
    # do and the index of the reference backup, which is the most
    # recent backup at any lower level.
    #
    @{$Conf{IncrLevels}} = [$Conf{IncrLevels}]
                            unless ref($Conf{IncrLevels}) eq "ARRAY";
    @{$Conf{IncrLevels}} = [1] if ( !@{$Conf{IncrLevels}} );
    $incrCntSinceFull = $incrCntSinceFull % @{$Conf{IncrLevels}};
    $incrLevel = $Conf{IncrLevels}[$incrCntSinceFull];
    for ( my $i = 0 ; $i < $incrLevel ; $i++ ) {
        my $idx = $lastIdxByLevel[$i];
        next if ( !defined($idx) );
        if ( !defined($incrBaseTime)
                || $Backups[$idx]{startTime} > $incrBaseTime ) {
            $incrBaseBkupNum = $Backups[$idx]{num};
            $incrBaseLevel   = $Backups[$idx]{level};
            $incrBaseTime    = $Backups[$idx]{startTime};
        }
    }
    #
    # Can't find any earlier lower-level backup!  Shouldn't
    # happen - just do full instead
    #
    if ( !defined($incrBaseBkupNum) || $incrLevel < 1 ) {
        $type = "full";
        $incrBaseBkupNum = $lastBkupNum;
    }
} else {
    NothingToDo($needLink);
}

#
# Create top-level directories if they don't exist
#
foreach my $dir ( (
            "$Conf{TopDir}",
            "$Conf{TopDir}/pool",
            "$Conf{TopDir}/cpool",
            "$Conf{TopDir}/pc",
            "$Conf{TopDir}/trash",
        ) ) {
    next if ( -d $dir );
    mkpath($dir, 0, 0750);
    if ( !-d $dir ) {
        print("Failed to create $dir\n");
        printf(LOG "%sFailed to create directory %s\n", $bpc->timeStamp, $dir);
        print("link $clientURI\n") if ( $needLink );
        exit(1);
    } else {
        printf(LOG "%sCreated directory %s\n", $bpc->timeStamp, $dir);
    }
}

if ( !$bpc->HardlinkTest($Dir, "$TopDir/cpool") ) {
    print(LOG $bpc->timeStamp, "Can't create a test hardlink between a file"
               . " in $Dir and $TopDir/cpool.  Either these are different"
               . " file systems, or this file system doesn't support hardlinks,"
               . " or these directories don't exist, or there is a permissions"
               . " problem, or the file system is out of inodes or full.  Use"
               . " df, df -i, and ls -ld to check each of these possibilities."
               . " Quitting...\n");
    print("test hardlink between $Dir and $TopDir/cpool failed\n");
    print("link $clientURI\n") if ( $needLink );
    exit(1);
}

if ( !$opts{d} ) {
    #
    # In the non-DHCP case, make sure the host can be looked up
    # via NS, or otherwise find the IP address via NetBios.
    #
    if ( $Conf{ClientNameAlias} ne "" ) {
        $host = $Conf{ClientNameAlias};
    } else {
        $host = $client;
    }
    if ( !defined(gethostbyname($host)) ) {
        #
        # Ok, NS doesn't know about it.  Maybe it is a NetBios name
        # instead.
        #
	print(STDERR "Name server doesn't know about $host; trying NetBios\n")
			if ( $opts{v} );
        if ( !defined($hostIP = $bpc->NetBiosHostIPFind($host)) ) {
	    print(LOG $bpc->timeStamp, "Can't find host $host via netbios\n");
            print("host not found\n");
            exit(1);
        }
    } else {
        $hostIP = $host;
    }
}

#
# Check if $host is alive
#
my $delay = $bpc->CheckHostAlive($hostIP);
if ( $delay < 0 ) {
    print(LOG $bpc->timeStamp, "no ping response\n");
    print("no ping response\n");
    print("link $clientURI\n") if ( $needLink );
    exit(1);
} elsif ( $delay > $Conf{PingMaxMsec} ) {
    printf(LOG "%sping too slow: %.4gmsec\n", $bpc->timeStamp, $delay);
    printf("ping too slow: %.4gmsec (threshold is %gmsec)\n",
                    $delay, $Conf{PingMaxMsec});
    print("link $clientURI\n") if ( $needLink );
    exit(1);
}

#
# Make sure it is really the machine we expect (only for fixed addresses,
# since we got the DHCP address above).
#
if ( !$opts{d} && (my $errMsg = CorrectHostCheck($hostIP, $host)) ) {
    print(LOG $bpc->timeStamp, "dump failed: $errMsg\n");
    print("dump failed: $errMsg\n");
    exit(1);
} elsif ( $opts{d} ) {
    print(LOG $bpc->timeStamp, "$host is dhcp $hostIP, user is $user\n");
}

#
# Get a clean directory $Dir/new
#
$bpc->RmTreeDefer("$TopDir/trash", "$Dir/new") if ( -d "$Dir/new" );

#
# Setup file extension for compression and open XferLOG output file
#
if ( $Conf{CompressLevel} && !BackupPC::FileZIO->compOk ) {
    print(LOG $bpc->timeStamp, "dump failed: can't find Compress::Zlib\n");
    print("dump failed: can't find Compress::Zlib\n");
    exit(1);
}
my $fileExt = $Conf{CompressLevel} > 0 ? ".z" : "";
my $XferLOG = BackupPC::FileZIO->open("$Dir/XferLOG$fileExt", 1,
                                     $Conf{CompressLevel});
if ( !defined($XferLOG) ) {
    print(LOG $bpc->timeStamp, "dump failed: unable to open/create"
			     . " $Dir/XferLOG$fileExt\n");
    print("dump failed: unable to open/create $Dir/XferLOG$fileExt\n");
    exit(1);
}

#
# Ignore the partial dump in the case of an incremental
# or when the partial is too old.  A partial is a partial full.
#
if ( $type ne "full" || time - $lastPartial > $Conf{PartialAgeMax} * 24*3600 ) {
    $partialNum = undef;
    $partialIdx = -1;
}

#
# If this is a partial, copy the old XferLOG file
#
if ( $partialNum ) {
    my($compress, $fileName);
    if ( -f "$Dir/XferLOG.$partialNum.z" ) {
	$fileName = "$Dir/XferLOG.$partialNum.z";
	$compress = 1;
    } elsif ( -f "$Dir/XferLOG.$partialNum" ) {
	$fileName = "$Dir/XferLOG.$partialNum";
	$compress = 0;
    }
    if ( my $oldLOG = BackupPC::FileZIO->open($fileName, 0, $compress) ) {
	my $data;
	while ( $oldLOG->read(\$data, 65536) > 0 ) {
	    $XferLOG->write(\$data);
	}
	$oldLOG->close;
    }
}

$XferLOG->writeTeeStderr(1) if ( $opts{v} );
unlink("$Dir/NewFileList") if ( -f "$Dir/NewFileList" );

my $startTime     = time();
my $tarErrs       = 0;
my $nFilesExist   = 0;
my $sizeExist     = 0;
my $sizeExistComp = 0;
my $nFilesTotal   = 0;
my $sizeTotal     = 0;
my($logMsg, %stat, $xfer, $ShareNames, $noFilesErr);
my $newFilesFH;

$ShareNames = BackupPC::Xfer::getShareNames(\%Conf);

#
# Run an optional pre-dump command
#
UserCommandRun("DumpPreUserCmd");
if ( $? && $Conf{UserCmdCheckStatus} ) {
    print(LOG $bpc->timeStamp,
            "DumpPreUserCmd returned error status $?... exiting\n");
    $XferLOG->write(\"DumpPreUserCmd returned error status $?... exiting\n");
    $stat{hostError} = "DumpPreUserCmd returned error status $?";
    BackupFailCleanup();
}
$NeedPostCmd = 1;

#
# Now backup each of the shares
#
my $shareDuplicate = {};
for my $shareName ( @$ShareNames ) {
    local(*RH, *WH);

    #
    # Convert $shareName to utf8 octets
    #
    $shareName = encode("utf8", $shareName);
    $stat{xferOK} = $stat{hostAbort} = undef;
    $stat{hostError} = $stat{lastOutputLine} = undef;
    if ( $shareName eq "" ) {
        print(LOG $bpc->timeStamp,
                  "unexpected empty share name skipped\n");
        next;
    }
    if ( $shareDuplicate->{$shareName} ) {
        print(LOG $bpc->timeStamp,
                  "unexpected repeated share name $shareName skipped\n");
        next;
    }
    $shareDuplicate->{$shareName} = 1;

    UserCommandRun("DumpPreShareCmd", $shareName);
    if ( $? && $Conf{UserCmdCheckStatus} ) {
        print(LOG $bpc->timeStamp,
                "DumpPreShareCmd returned error status $?... exiting\n");
        UserCommandRun("DumpPostUserCmd") if ( $NeedPostCmd );
        $XferLOG->write(\"DumpPreShareCmd returned error status $?... exiting\n");
        $stat{hostError} = "DumpPreShareCmd returned error status $?";
        BackupFailCleanup();
    }

    $xfer = BackupPC::Xfer::create($Conf{XferMethod}, $bpc);
    if ( !defined($xfer) ) {
        my $errStr = BackupPC::Xfer::errStr();
        print(LOG $bpc->timeStamp, "dump failed: $errStr\n");
        UserCommandRun("DumpPostShareCmd", $shareName) if ( $NeedPostCmd );
        UserCommandRun("DumpPostUserCmd") if ( $NeedPostCmd );
        $XferLOG->write(\"BackupPC::Xfer::create failed: $errStr\n");
        $stat{hostError} = $errStr;
        BackupFailCleanup();
    }

    my $useTar = $xfer->useTar;

    if ( $useTar ) {
	#
	# This xfer method outputs a tar format file, so we start a
	# BackupPC_tarExtract to extract the data.
	#
	# Create a socketpair to connect the Xfer method to BackupPC_tarExtract
	# WH is the write handle for writing, provided to the transport
	# program, and RH is the other end of the socket for reading,
	# provided to BackupPC_tarExtract.
	#
        if ( socketpair(RH, WH, AF_UNIX, SOCK_STREAM, PF_UNSPEC) ) {
	    shutdown(RH, 1);	# no writing to this socket
	    shutdown(WH, 0);	# no reading from this socket
	    setsockopt(RH, SOL_SOCKET, SO_RCVBUF, 8 * 65536);
	    setsockopt(WH, SOL_SOCKET, SO_SNDBUF, 8 * 65536);
	} else {
	    #
	    # Default to pipe() if socketpair() doesn't work.
	    #
	    pipe(RH, WH);
	}

	#
	# fork a child for BackupPC_tarExtract.  TAR is a file handle
	# on which we (the parent) read the stdout & stderr from
	# BackupPC_tarExtract.
	#
	if ( !defined($tarPid = open(TAR, "-|")) ) {
	    print(LOG $bpc->timeStamp, "can't fork to run tar\n");
	    print("can't fork to run tar\n");
	    close(RH);
	    close(WH);
	    last;
	}
	binmode(TAR);
	if ( !$tarPid ) {
	    #
	    # This is the tar child.  Close the write end of the pipe,
	    # clone STDERR to STDOUT, clone STDIN from RH, and then
	    # exec BackupPC_tarExtract.
	    #
	    setpgrp 0,0;
	    close(WH);
	    close(STDERR);
	    open(STDERR, ">&STDOUT");
	    close(STDIN);
	    open(STDIN, "<&RH");
	    alarm(0);
	    exec("$BinDir/BackupPC_tarExtract", $client, $shareName,
			 $Conf{CompressLevel});
	    print(LOG $bpc->timeStamp,
			"can't exec $BinDir/BackupPC_tarExtract\n");
	    exit(0);
	}
    } elsif ( !defined($newFilesFH) ) {
	#
	# We need to create the NewFileList output file
	#
	local(*NEW_FILES);
	open(NEW_FILES, ">", "$TopDir/pc/$client/NewFileList")
		     || die("can't open $TopDir/pc/$client/NewFileList");
	$newFilesFH = *NEW_FILES;
	binmode(NEW_FILES);
    }

    #
    # Run the transport program
    #
    $xfer->args({
        host         => $host,
        client       => $client,
        hostIP       => $hostIP,
        shareName    => $shareName,
        pipeRH       => *RH,
        pipeWH       => *WH,
        XferLOG      => $XferLOG,
	newFilesFH   => $newFilesFH,
        outDir       => $Dir,
        type         => $type,
        incrBaseTime => $incrBaseTime,
        incrBaseBkupNum => $incrBaseBkupNum,
	backups      => \@Backups,
	compress     => $Conf{CompressLevel},
	XferMethod   => $Conf{XferMethod},
	logLevel     => $Conf{XferLogLevel},
        partialNum   => $partialNum,
	pidHandler   => \&pidHandler,
	completionPercent => \&completionPercent,
    });

    if ( !defined($logMsg = $xfer->start()) ) {
        my $errStr = "xfer start failed: " . $xfer->errStr . "\n";
        print(LOG $bpc->timeStamp, $errStr);
        #
        # kill off the tar process, first nicely then forcefully
        #
	if ( $tarPid > 0 ) {
	    kill($bpc->sigName2num("INT"), $tarPid);
	    sleep(1);
	    kill($bpc->sigName2num("KILL"), $tarPid);
	}
	if ( @xferPid ) {
	    kill($bpc->sigName2num("INT"), @xferPid);
	    sleep(1);
	    kill($bpc->sigName2num("KILL"), @xferPid);
	}
	UserCommandRun("DumpPostShareCmd", $shareName) if ( $NeedPostCmd );
	UserCommandRun("DumpPostUserCmd") if ( $NeedPostCmd );
        $XferLOG->write(\"xfer start failed: $errStr\n");
        $stat{hostError} = $errStr;
        BackupFailCleanup();
    }

    @xferPid = $xfer->xferPid;

    if ( $useTar ) {
	#
	# The parent must close both handles on the pipe since the children
	# are using these handles now.
	#
	close(RH);
	close(WH);
    }
    print(LOG $bpc->timeStamp, $logMsg, "\n");
    $XferLOG->write(\"$logMsg\n");
    print("started $type dump, share=$shareName\n");

    pidHandler(@xferPid);

    if ( $useTar ) {
	#
	# Parse the output of the transfer program and BackupPC_tarExtract
	# while they run.  Since we might be reading from two or more children
	# we use a select.
	#
	my($FDread, $tarOut, $mesg);
	vec($FDread, fileno(TAR), 1) = 1;
	$xfer->setSelectMask(\$FDread);

	SCAN: while ( 1 ) {
	    my $ein = $FDread;
	    last if ( $FDread =~ /^\0*$/ );
	    select(my $rout = $FDread, undef, $ein, undef);
            if ( vec($rout, fileno(TAR), 1) ) {
                if ( sysread(TAR, $mesg, 8192) <= 0 ) {
                    vec($FDread, fileno(TAR), 1) = 0;
                    close(TAR);
                } else {
                    $tarOut .= $mesg;
                }
            }
            while ( $tarOut =~ /(.*?)[\n\r]+(.*)/s ) {
                $_ = $1;
                $tarOut = $2;
                if ( /^  / ) {
                    $XferLOG->write(\"$_\n");
                } else {
                    $XferLOG->write(\"tarExtract: $_\n");
                }
                if ( /^BackupPC_tarExtact aborting \((.*)\)/ ) {
                    $stat{hostError} = $1;
                }
                if ( /^Done: (\d+) errors, (\d+) filesExist, (\d+) sizeExist, (\d+) sizeExistComp, (\d+) filesTotal, (\d+) sizeTotal/ ) {
                    $tarErrs       += $1;
                    $nFilesExist   += $2;
                    $sizeExist     += $3;
                    $sizeExistComp += $4;
                    $nFilesTotal   += $5;
                    $sizeTotal     += $6;
                }
            }
	    last if ( !$xfer->readOutput(\$FDread, $rout) );
	    while ( my $str = $xfer->logMsgGet ) {
		print(LOG $bpc->timeStamp, "xfer: $str\n");
	    }
	    if ( $xfer->getStats->{fileCnt} == 1 ) {
		#
		# Make sure it is still the machine we expect.  We do this while
		# the transfer is running to avoid a potential race condition if
		# the ip address was reassigned by dhcp just before we started
		# the transfer.
		#
		if ( my $errMsg = CorrectHostCheck($hostIP, $host) ) {
		    $stat{hostError} = $errMsg if ( $stat{hostError} eq "" );
		    last SCAN;
		}
	    }
	}
    } else {
	#
	# otherwise the xfer module does everything for us
	#
	my @results = $xfer->run();
	$tarErrs       += $results[0];
	$nFilesExist   += $results[1];
	$sizeExist     += $results[2];
	$sizeExistComp += $results[3];
	$nFilesTotal   += $results[4];
	$sizeTotal     += $results[5];
    }

    #
    # Merge the xfer status (need to accumulate counts)
    #
    my $newStat = $xfer->getStats;
    if ( $newStat->{fileCnt} == 0 ) {
       $noFilesErr ||= "No files dumped for share $shareName";
    }
    foreach my $k ( (keys(%stat), keys(%$newStat)) ) {
        next if ( !defined($newStat->{$k}) );
        if ( $k =~ /Cnt$/ ) {
            $stat{$k} += $newStat->{$k};
            delete($newStat->{$k});
            next;
        }
        if ( !defined($stat{$k}) ) {
            $stat{$k} = $newStat->{$k};
            delete($newStat->{$k});
            next;
        }
    }

    if ( $NeedPostCmd ) {
        UserCommandRun("DumpPostShareCmd", $shareName);
        if ( $? && $Conf{UserCmdCheckStatus} ) {
            print(LOG $bpc->timeStamp,
                    "DumpPostShareCmd returned error status $?... exiting\n");
            $stat{hostError} = "DumpPostShareCmd returned error status $?";
        }
    }

    $stat{xferOK} = 0 if ( $stat{hostError} || $stat{hostAbort} );
    if ( !$stat{xferOK} ) {
        #
        # kill off the transfer program, first nicely then forcefully
        #
	if ( @xferPid ) {
	    kill($bpc->sigName2num("INT"), @xferPid);
	    sleep(1);
	    kill($bpc->sigName2num("KILL"), @xferPid);
	}
        #
        # kill off the tar process, first nicely then forcefully
        #
	if ( $tarPid > 0 ) {
	    kill($bpc->sigName2num("INT"), $tarPid);
	    sleep(1);
	    kill($bpc->sigName2num("KILL"), $tarPid);
	}
        #
        # don't do any more shares on this host
        #
        last;
    }
    #
    # Wait for any child processes to exit
    #
    # 1 while ( wait() >= 0 );
}

#
# If this is a full, and any share had zero files then consider the dump bad
#
if ( $type eq "full" && $stat{hostError} eq ""
	    && length($noFilesErr) && $Conf{BackupZeroFilesIsFatal} ) {
    $stat{hostError} = $noFilesErr;
    $stat{xferOK} = 0;
}

$stat{xferOK} = 0 if ( $Abort );

#
# If there is no "new" directory then the backup is bad
#
if ( $stat{xferOK} && !-d "$Dir/new" ) {
    $stat{hostError} = "No backup directory $Dir/new"
                            if ( $stat{hostError} eq "" );
    $stat{xferOK} = 0;
}

#
# Do one last check to make sure it is still the machine we expect.
#
if ( $stat{xferOK} && (my $errMsg = CorrectHostCheck($hostIP, $host)) ) {
    $stat{hostError} = $errMsg;
    $stat{xferOK} = 0;
}

UserCommandRun("DumpPostUserCmd") if ( $NeedPostCmd );
if ( $? && $Conf{UserCmdCheckStatus} ) {
    print(LOG $bpc->timeStamp,
            "DumpPostUserCmd returned error status $?... exiting\n");
    $stat{hostError} = "DumpPostUserCmd returned error status $?";
    $stat{xferOK} = 0;
}
close($newFilesFH) if ( defined($newFilesFH) );

my $endTime = time();

#
# If the dump failed, clean up
#
if ( !$stat{xferOK} ) {
    $stat{hostError} = $stat{lastOutputLine} if ( $stat{hostError} eq "" );
    if ( $stat{hostError} ) {
        print(LOG $bpc->timeStamp,
                  "Got fatal error during xfer ($stat{hostError})\n");
	$XferLOG->write(\"Got fatal error during xfer ($stat{hostError})\n");
    }
    if ( !$Abort ) {
	#
	# wait a short while and see if the system is still alive
	#
	sleep(5);
	if ( $bpc->CheckHostAlive($hostIP) < 0 ) {
	    $stat{hostAbort} = 1;
	}
	if ( $stat{hostAbort} ) {
	    $stat{hostError} = "lost network connection during backup";
	}
	print(LOG $bpc->timeStamp, "Backup aborted ($stat{hostError})\n");
	$XferLOG->write(\"Backup aborted ($stat{hostError})\n");
    } else {
	$XferLOG->write(\"Backup aborted by user signal\n");
    }

    #
    # Close the log file and call BackupFailCleanup, which exits.
    #
    BackupFailCleanup();
}

my $newNum = BackupSave();

my $otherCount = $stat{xferErrCnt} - $stat{xferBadFileCnt}
                                   - $stat{xferBadShareCnt};
$stat{fileCnt}         ||= 0;
$stat{byteCnt}         ||= 0;
$stat{xferErrCnt}      ||= 0;
$stat{xferBadFileCnt}  ||= 0;
$stat{xferBadShareCnt} ||= 0;
print(LOG $bpc->timeStamp,
          "$type backup $newNum complete, $stat{fileCnt} files,"
        . " $stat{byteCnt} bytes,"
        . " $stat{xferErrCnt} xferErrs ($stat{xferBadFileCnt} bad files,"
        . " $stat{xferBadShareCnt} bad shares, $otherCount other)\n");

BackupExpire($client);

print("$type backup complete\n");

###########################################################################
# Subroutines
###########################################################################

sub NothingToDo
{
    my($needLink) = @_;

    print("nothing to do\n");
    print("link $clientURI\n") if ( $needLink );
    exit(0);
}

sub catch_signal
{
    my $sigName = shift;

    #
    # The first time we receive a signal we try to gracefully
    # abort the backup.  This allows us to keep a partial dump
    # with the in-progress file deleted and attribute caches
    # flushed to disk etc.
    #
    if ( !length($SigName) ) {
	my $reason;
	if ( $sigName eq "INT" ) {
	    $reason = "aborted by user (signal=$sigName)";
	} else {
	    $reason = "aborted by signal=$sigName";
	}
	if ( $Pid == $$ ) {
	    #
	    # Parent logs a message
	    #
	    print(LOG $bpc->timeStamp,
		    "Aborting backup up after signal $sigName\n");

	    #
	    # Tell xfer to abort, but only if we actually started one
	    #
	    $xfer->abort($reason) if ( defined($xfer) );

	    #
	    # Send ALRMs to BackupPC_tarExtract if we are using it
	    #
	    if ( $tarPid > 0 ) {
		kill($bpc->sigName2num("ALRM"), $tarPid);
	    }

	    #
	    # Schedule a 20 second timer in case the clean
	    # abort doesn't complete
	    #
	    alarm(20);
	} else {
	    #
	    # Children ignore anything other than ALRM and INT
	    #
	    if ( $sigName ne "ALRM" && $sigName ne "INT" ) {
		return;
	    }

	    #
	    # The child also tells xfer to abort
	    #
	    $xfer->abort($reason);

	    #
	    # Schedule a 15 second timer in case the clean
	    # abort doesn't complete
	    #
	    alarm(15);
	}
	$SigName = $sigName;
	$Abort = 1;
	return;
    }

    #
    # This is a second signal: time to clean up.
    #
    if ( $Pid != $$ && ($sigName eq "ALRM" || $sigName eq "INT") ) {
	#
	# Children quit quietly on ALRM or INT
	#
	exit(1)
    }

    #
    # Ignore other signals in children
    #
    return if ( $Pid != $$ );

    $SIG{$sigName} = 'IGNORE';
    UserCommandRun("DumpPostUserCmd") if ( $NeedPostCmd );
    $XferLOG->write(\"exiting after signal $sigName\n");
    if ( @xferPid ) {
        kill($bpc->sigName2num("INT"), @xferPid);
	sleep(1);
	kill($bpc->sigName2num("KILL"), @xferPid);
    }
    if ( $tarPid > 0 ) {
        kill($bpc->sigName2num("INT"), $tarPid);
	sleep(1);
	kill($bpc->sigName2num("KILL"), $tarPid);
    }
    if ( $sigName eq "INT" ) {
        $stat{hostError} = "aborted by user (signal=$sigName)";
    } else {
        $stat{hostError} = "received signal=$sigName";
    }
    BackupFailCleanup();
}

sub CheckForNewFiles
{
    if ( -f _ && $File::Find::name !~ /\/fattrib$/ ) {
        $nFilesTotal++;
    } elsif ( -d _ ) {
	#
	# No need to check entire tree
	#
        $File::Find::prune = 1 if ( $nFilesTotal );
    }
}

sub BackupFailCleanup
{
    my $fileExt = $Conf{CompressLevel} > 0 ? ".z" : "";
    my $keepPartial = 0;

    #
    # We keep this backup if it is a full and we actually backed
    # up some files.  If the prior backup was a partial too, we
    # only keep this backup if it has more files than the previous
    # partial.
    #
    if ( $type eq "full" ) {
	if ( $nFilesTotal == 0 && $xfer->getStats->{fileCnt} == 0 ) {
	    #
	    # Xfer didn't report any files, but check in the new
	    # directory just in case.
	    #
	    find(\&CheckForNewFiles, "$Dir/new");
        }
        my $str;
        if ( $nFilesTotal > $partialFileCnt
                || $xfer->getStats->{fileCnt} > $partialFileCnt ) {
            #
            # If the last backup wasn't a partial then
            # $partialFileCnt is undefined, so the above
            # test is simply $nFilesTotal > 0
            #
	    $keepPartial = 1;
            if ( $partialFileCnt ) {
                $str = "Saving this as a partial backup\n";
            } else {
                $str = sprintf("Saving this as a partial backup, replacing the"
                         . " prior one (got %d and %d files versus %d)\n",
                         $nFilesTotal, $xfer->getStats->{fileCnt}, $partialFileCnt);
            }
	} else {
            $str = sprintf("Not saving this as a partial backup since it has fewer"
                     . " files than the prior one (got %d and %d files versus %d)\n",
                     $nFilesTotal, $xfer->getStats->{fileCnt}, $partialFileCnt);
        }
        $XferLOG->write(\$str);
    }

    #
    # Don't keep partials if they are disabled
    #
    $keepPartial = 0 if ( $Conf{PartialAgeMax} < 0 );

    if ( !$keepPartial ) {
        #
        # No point in saving this dump; get rid of eveything.
        #
        $XferLOG->close();
        unlink("$Dir/timeStamp.level0")    if ( -f "$Dir/timeStamp.level0" );
        unlink("$Dir/SmbLOG.bad")          if ( -f "$Dir/SmbLOG.bad" );
        unlink("$Dir/SmbLOG.bad$fileExt")  if ( -f "$Dir/SmbLOG.bad$fileExt" );
        unlink("$Dir/XferLOG.bad")         if ( -f "$Dir/XferLOG.bad" );
        unlink("$Dir/XferLOG.bad$fileExt") if ( -f "$Dir/XferLOG.bad$fileExt" );
        unlink("$Dir/NewFileList")         if ( -f "$Dir/NewFileList" );
        rename("$Dir/XferLOG$fileExt", "$Dir/XferLOG.bad$fileExt");
        $bpc->RmTreeDefer("$TopDir/trash", "$Dir/new") if ( -d "$Dir/new" );
        print("dump failed: $stat{hostError}\n");
        $XferLOG->close();
        print("link $clientURI\n") if ( $needLink );
        exit(1);
    }
    #
    # Ok, now we should save this as a partial dump
    #
    $type = "partial";
    my $newNum = BackupSave();
    print("dump failed: $stat{hostError}\n");
    print("link $clientURI\n") if ( $needLink );
    print(LOG $bpc->timeStamp, "Saved partial dump $newNum\n");
    exit(2);
}

#
# Decide which old backups should be expired by moving them
# to $TopDir/trash.
#
sub BackupExpire
{
    my($client) = @_;
    my($Dir) = "$TopDir/pc/$client";
    my(@Backups) = $bpc->BackupInfoRead($client);
    my($cntFull, $cntIncr, $firstFull, $firstIncr, $oldestIncr,
       $oldestFull, $changes);

    if ( $Conf{FullKeepCnt} <= 0 ) {
        print(LOG $bpc->timeStamp,
                  "Invalid value for \$Conf{FullKeepCnt}=$Conf{FullKeepCnt}\n");
	print(STDERR
            "Invalid value for \$Conf{FullKeepCnt}=$Conf{FullKeepCnt}\n")
			    if ( $opts{v} );
        return;
    }
    while ( 1 ) {
	$cntFull = $cntIncr = 0;
	$oldestIncr = $oldestFull = 0;
	for ( my $i = 0 ; $i < @Backups ; $i++ ) {
	    if ( $Backups[$i]{type} eq "full" ) {
		$firstFull = $i if ( $cntFull == 0 );
		$cntFull++;
	    } elsif ( $Backups[$i]{type} eq "incr" ) {
		$firstIncr = $i if ( $cntIncr == 0 );
		$cntIncr++;
	    }
	}
	$oldestIncr = (time - $Backups[$firstIncr]{startTime}) / (24 * 3600)
                        if ( $cntIncr > 0 );
	$oldestFull = (time - $Backups[$firstFull]{startTime}) / (24 * 3600)
                        if ( $cntFull > 0 );

        #
        # With multi-level incrementals, several of the following
        # incrementals might depend upon this one, so we have to
        # delete all of the them.  Figure out if that is possible
        # by counting the number of consecutive incrementals that
        # are unfilled and have a level higher than this one.
        #
        my $cntIncrDel = 1;
        my $earliestIncr = $oldestIncr;

	for ( my $i = $firstIncr + 1 ; $i < @Backups ; $i++ ) {
            last if ( $Backups[$i]{level} <= $Backups[$firstIncr]{level}
                   || !$Backups[$i]{noFill} );
            $cntIncrDel++;
            $earliestIncr = (time - $Backups[$i]{startTime}) / (24 * 3600);
        }

	if ( $cntIncr >= $Conf{IncrKeepCnt} + $cntIncrDel
		|| ($cntIncr >= $Conf{IncrKeepCntMin} + $cntIncrDel
		    && $earliestIncr > $Conf{IncrAgeMax}) ) {
            #
            # Only delete an incr backup if the Conf settings are satisfied
            # for all $cntIncrDel incrementals.  Since BackupRemove() does
            # a splice() we need to do the deletes in the reverse order.
            # 
            for ( my $i = $firstIncr + $cntIncrDel - 1 ;
                    $i >= $firstIncr ; $i-- ) {
                print(LOG $bpc->timeStamp,
                          "removing incr backup $Backups[$i]{num}\n");
                BackupRemove($client, \@Backups, $i);
                $changes++;
            }
            next;
        }

        #
        # Delete any old full backups, according to $Conf{FullKeepCntMin}
	# and $Conf{FullAgeMax}.
        #
	# First make sure that $Conf{FullAgeMax} is at least bigger
	# than $Conf{FullPeriod} * $Conf{FullKeepCnt}, including
	# the exponential array case.
        #
	my $fullKeepCnt = $Conf{FullKeepCnt};
	$fullKeepCnt = [$fullKeepCnt] if ( ref($fullKeepCnt) ne "ARRAY" );
	my $fullAgeMax;
	my $fullPeriod = int(0.5 + $Conf{FullPeriod});
        $fullPeriod = 7 if ( $fullPeriod <= 0 );
	for ( my $i = 0 ; $i < @$fullKeepCnt ; $i++ ) {
	    $fullAgeMax += $fullKeepCnt->[$i] * $fullPeriod;
	    $fullPeriod *= 2;
	}
	$fullAgeMax += $fullPeriod;	# add some buffer

        if ( $cntFull > $Conf{FullKeepCntMin}
               && $oldestFull > $Conf{FullAgeMax}
               && $oldestFull > $fullAgeMax
	       && $Conf{FullKeepCntMin} > 0
	       && $Conf{FullAgeMax} > 0
               && (@Backups <= $firstFull + 1
                        || !$Backups[$firstFull + 1]{noFill}) ) {
            #
            # Only delete a full backup if the Conf settings are satisfied.
            # We also must make sure that either this backup is the most
            # recent one, or the next backup is filled.
            # (We can't deleted a full backup if the next backup is not
            # filled.)
            # 
	    print(LOG $bpc->timeStamp,
                   "removing old full backup $Backups[$firstFull]{num}\n");
            BackupRemove($client, \@Backups, $firstFull);
            $changes++;
            next;
        }

        #
        # Do new-style full backup expiry, which includes the the case
	# where $Conf{FullKeepCnt} is an array.
        #
        last if ( !BackupFullExpire($client, \@Backups) );
        $changes++;
    }
    $bpc->BackupInfoWrite($client, @Backups) if ( $changes );
}

#
# Handle full backup expiry, using exponential periods.
#
sub BackupFullExpire
{
    my($client, $Backups) = @_;
    my $fullCnt = 0;
    my $fullPeriod = $Conf{FullPeriod};
    my $origFullPeriod = $fullPeriod;
    my $fullKeepCnt = $Conf{FullKeepCnt};
    my $fullKeepIdx = 0;
    my(@delete, @fullList);

    #
    # Don't delete anything if $Conf{FullPeriod} or $Conf{FullKeepCnt} are
    # not defined - possibly a corrupted config.pl file.
    #
    return if ( !defined($Conf{FullPeriod}) || !defined($Conf{FullKeepCnt}) );

    #
    # If regular backups are still disabled with $Conf{FullPeriod} < 0,
    # we still expire backups based on a typical FullPeriod value - weekly.
    #
    $fullPeriod = 7 if ( $fullPeriod <= 0 );

    $fullKeepCnt = [$fullKeepCnt] if ( ref($fullKeepCnt) ne "ARRAY" );

    for ( my $i = 0 ; $i < @$Backups ; $i++ ) {
        next if ( $Backups->[$i]{type} ne "full" );
        push(@fullList, $i);
    }
    for ( my $k = @fullList - 1 ; $k >= 0 ; $k-- ) {
        my $i = $fullList[$k];
        my $prevFull = $fullList[$k-1] if ( $k > 0 );
        #
        # Don't delete any full that is followed by an unfilled backup,
        # since it is needed for restore.
        #
        my $noDelete = $i + 1 < @$Backups ? $Backups->[$i+1]{noFill} : 0;

        if ( !$noDelete && 
              ($fullKeepIdx >= @$fullKeepCnt
              || $k > 0
                 && $fullKeepIdx > 0
                 && $Backups->[$i]{startTime} - $Backups->[$prevFull]{startTime}
                             < ($fullPeriod - $origFullPeriod / 2) * 24 * 3600
               )
            ) {
            #
            # Delete the full backup
            #
            #print("Deleting backup $i ($prevFull)\n");
            unshift(@delete, $i);
        } else {
            $fullCnt++;
            while ( $fullKeepIdx < @$fullKeepCnt
                     && $fullCnt >= $fullKeepCnt->[$fullKeepIdx] ) {
                $fullKeepIdx++;
                $fullCnt = 0;
                $fullPeriod = 2 * $fullPeriod;
            }
        }
    }
    #
    # Now actually delete the backups
    #
    for ( my $i = @delete - 1 ; $i >= 0 ; $i-- ) {
        print(LOG $bpc->timeStamp,
               "removing full backup $Backups->[$delete[$i]]{num}\n");
        BackupRemove($client, $Backups, $delete[$i]);
    }
    return @delete;
}

#
# Removes any partial backups
#
sub BackupPartialRemove
{
    my($client, $Backups) = @_;

    for ( my $i = @$Backups - 1 ; $i >= 0 ; $i-- ) {
        next if ( $Backups->[$i]{type} ne "partial" );
        BackupRemove($client, $Backups, $i);
    }
}

sub BackupSave
{
    my @Backups = $bpc->BackupInfoRead($client);
    my $num  = -1;
    my $newFilesFH;

    #
    # Since we got a good backup we should remove any partial dumps
    # (the new backup might also be a partial, but that's ok).
    #
    BackupPartialRemove($client, \@Backups);
    $needLink = 1 if ( -f "$Dir/NewFileList" );

    #
    # Number the new backup
    #
    for ( my $i = 0 ; $i < @Backups ; $i++ ) {
        $num = $Backups[$i]{num} if ( $num < $Backups[$i]{num} );
    }
    $num++;
    $bpc->RmTreeDefer("$TopDir/trash", "$Dir/$num") if ( -d "$Dir/$num" );
    if ( !rename("$Dir/new", "$Dir/$num") ) {
        print(LOG $bpc->timeStamp, "Rename $Dir/new -> $Dir/$num failed\n");
        $stat{xferOK} = 0;
        return;
    }

    #
    # Add the new backup information to the backup file
    #
    my $i = @Backups;
    $Backups[$i]{num}           = $num;
    $Backups[$i]{type}          = $type;
    $Backups[$i]{startTime}     = $startTime;
    $Backups[$i]{endTime}       = $endTime;
    $Backups[$i]{size}          = $sizeTotal;
    $Backups[$i]{nFiles}        = $nFilesTotal;
    $Backups[$i]{xferErrs}      = $stat{xferErrCnt} || 0;
    $Backups[$i]{xferBadFile}   = $stat{xferBadFileCnt} || 0;
    $Backups[$i]{xferBadShare}  = $stat{xferBadShareCnt} || 0;
    $Backups[$i]{nFilesExist}   = $nFilesExist;
    $Backups[$i]{sizeExist}     = $sizeExist;
    $Backups[$i]{sizeExistComp} = $sizeExistComp;
    $Backups[$i]{tarErrs}       = $tarErrs;
    $Backups[$i]{compress}      = $Conf{CompressLevel};
    $Backups[$i]{noFill}        = $type eq "incr" ? 1 : 0;
    $Backups[$i]{level}         = $incrLevel;
    $Backups[$i]{mangle}        = 1;     # name mangling always on for v1.04+
    $Backups[$i]{xferMethod}    = $Conf{XferMethod};
    $Backups[$i]{charset}       = $Conf{ClientCharset};
    $Backups[$i]{version}       = $bpc->Version();
    #
    # Save the main backups file
    #
    $bpc->BackupInfoWrite($client, @Backups);
    #
    # Save just this backup's info in case the main backups file
    # gets corrupted
    #
    BackupPC::Storage->backupInfoWrite($Dir, $Backups[$i]{num},
                                             $Backups[$i]);

    unlink("$Dir/timeStamp.level0") if ( -f "$Dir/timeStamp.level0" );
    foreach my $ext ( qw(bad bad.z) ) {
	next if ( !-f "$Dir/XferLOG.$ext" );
	unlink("$Dir/XferLOG.$ext.old") if ( -f "$Dir/XferLOG.$ext" );
	rename("$Dir/XferLOG.$ext", "$Dir/XferLOG.$ext.old");
    }

    #
    # Now remove the bad files, replacing them if possible with links to
    # earlier backups.
    #
    foreach my $f ( $xfer->getBadFiles ) {
	my $j;
	my $shareM = $bpc->fileNameEltMangle($f->{share});
	my $fileM  = $bpc->fileNameMangle($f->{file});
	unlink("$Dir/$num/$shareM/$fileM");
	for ( $j = $i - 1 ; $j >= 0 ; $j-- ) {
	    my $file;
	    if ( $Backups[$j]{mangle} ) {
		$file = "$shareM/$fileM";
	    } else {
		$file = "$f->{share}/$f->{file}";
	    }
	    next if ( !-f "$Dir/$Backups[$j]{num}/$file" );

            my($exists, $digest, $origSize, $outSize, $errs)
                                = BackupPC::PoolWrite::LinkOrCopy(
                                      $bpc,
                                      "$Dir/$Backups[$j]{num}/$file",
                                      $Backups[$j]{compress},
                                      "$Dir/$num/$shareM/$fileM",
                                      $Conf{CompressLevel});
            if ( !$exists ) {
                #
                # the hard link failed, most likely because the target
                # file has too many links.  We have copied the file
                # instead, so add this to the new file list.
                #
                if ( !defined($newFilesFH) ) {
                    my $str = "Appending to NewFileList for $shareM/$fileM\n";
                    $XferLOG->write(\$str);
                    open($newFilesFH, ">>", "$TopDir/pc/$client/NewFileList")
                         || die("can't open $TopDir/pc/$client/NewFileList");
                    binmode($newFilesFH);
                }
                if ( -f "$Dir/$num/$shareM/$fileM" ) {
                    print($newFilesFH "$digest $origSize $shareM/$fileM\n");
                } else {
                    my $str = "Unable to link/copy $num/$f->{share}/$f->{file}"
                            . " to $Backups[$j]{num}/$f->{share}/$f->{file}\n";
                    $XferLOG->write(\$str);
                }
	    } else {
		my $str = "Bad file $num/$f->{share}/$f->{file} replaced"
                        . " by link to"
                        . " $Backups[$j]{num}/$f->{share}/$f->{file}\n";
		$XferLOG->write(\$str);
	    }
	    last;
	}
	if ( $j < 0 ) {
	    my $str = "Removed bad file $num/$f->{share}/$f->{file}"
                    . " (no older copy to link to)\n";
	    $XferLOG->write(\$str);
	}
    }
    close($newFilesFH) if ( defined($newFilesFH) );
    $XferLOG->close();
    rename("$Dir/XferLOG$fileExt", "$Dir/XferLOG.$num$fileExt");
    rename("$Dir/NewFileList", "$Dir/NewFileList.$num");

    return $num;
}

#
# Removes a specific backup
#
sub BackupRemove
{
    my($client, $Backups, $idx) = @_;
    my($Dir) = "$TopDir/pc/$client";

    if ( $Backups->[$idx]{num} eq "" ) {
        print("BackupRemove: ignoring empty backup number for idx $idx\n");
        return;
    }

    $bpc->RmTreeDefer("$TopDir/trash",
                      "$Dir/$Backups->[$idx]{num}");
    unlink("$Dir/SmbLOG.$Backups->[$idx]{num}")
                if ( -f "$Dir/SmbLOG.$Backups->[$idx]{num}" );
    unlink("$Dir/SmbLOG.$Backups->[$idx]{num}.z")
                if ( -f "$Dir/SmbLOG.$Backups->[$idx]{num}.z" );
    unlink("$Dir/XferLOG.$Backups->[$idx]{num}")
                if ( -f "$Dir/XferLOG.$Backups->[$idx]{num}" );
    unlink("$Dir/XferLOG.$Backups->[$idx]{num}.z")
                if ( -f "$Dir/XferLOG.$Backups->[$idx]{num}.z" );
    splice(@{$Backups}, $idx, 1);
}

sub CorrectHostCheck
{
    my($hostIP, $host) = @_;
    return if ( $hostIP eq $host && !$Conf{FixedIPNetBiosNameCheck}
		|| $Conf{NmbLookupCmd} eq "" );
    my($netBiosHost, $netBiosUser) = $bpc->NetBiosInfoGet($hostIP);
    return "host $host has mismatching netbios name $netBiosHost"
		if ( lc($netBiosHost) ne lc(substr($host, 0, 15)) );
    return;
}

#
# The Xfer method might tell us from time to time about processes
# it forks.  We tell BackupPC about this (for status displays) and
# keep track of the pids in case we cancel the backup
#
sub pidHandler
{
    @xferPid = @_;
    @xferPid = grep(/./, @xferPid);
    return if ( !@xferPid && $tarPid < 0 );
    my @pids = @xferPid;
    push(@pids, $tarPid) if ( $tarPid > 0 );
    my $str = join(",", @pids);
    $XferLOG->write(\"Xfer PIDs are now $str\n") if ( defined($XferLOG) );
    print("xferPids $str\n");
}

#
# The Xfer method might tell us from time to time about progress
# in the backup or restore
#
sub completionPercent
{
    my($percent) = @_;

    $percent = 100 if ( $percent > 100 );
    $percent =   0 if ( $percent <   0 );
    if ( !defined($completionPercent)
        || int($completionPercent + 0.5) != int($percent) ) {
            printf("completionPercent %.0f\n", $percent);
    }
    $completionPercent = $percent;
}

#
# Run an optional pre- or post-dump command
#
sub UserCommandRun
{
    my($cmdType, $sharename) = @_;

    return if ( !defined($Conf{$cmdType}) );
    my $vars = {
        xfer       => $xfer,
        client     => $client,
        host       => $host,
        hostIP     => $hostIP,
	user       => $Hosts->{$client}{user},
	moreUsers  => $Hosts->{$client}{moreUsers},
        share      => $ShareNames->[0],
        shares     => $ShareNames,
        XferMethod => $Conf{XferMethod},
        sshPath    => $Conf{SshPath},
        LOG        => *LOG,
        XferLOG    => $XferLOG,
        stat       => \%stat,
        xferOK     => $stat{xferOK} || 0,
	hostError  => $stat{hostError},
	type	   => $type,
	cmdType	   => $cmdType,
    };

    if ($cmdType eq 'DumpPreShareCmd' || $cmdType eq 'DumpPostShareCmd') {
	$vars->{share} = $sharename;
    }

    my $cmd = $bpc->cmdVarSubstitute($Conf{$cmdType}, $vars);
    $XferLOG->write(\"Executing $cmdType: @$cmd\n");
    #
    # Run the user's command, dumping the stdout/stderr into the
    # Xfer log file.  Also supply the optional $vars and %Conf in
    # case the command is really perl code instead of a shell
    # command.
    #
    $bpc->cmdSystemOrEval($cmd,
	    sub {
		$XferLOG->write(\$_[0]);
                print(LOG $bpc->timeStamp, "Output from $cmdType: ", $_[0]);
	    },
	    $vars, \%Conf);
}