#!/usr/bin/perl
#============================================================= -*-perl-*-
#
# BackupPC_restore: Restore files to a client.
#
# DESCRIPTION
#
#   Usage: BackupPC_restore <hostIP> <client> <reqFileName>
#
# AUTHOR
#   Craig Barratt  <cbarratt@users.sourceforge.net>
#
# COPYRIGHT
#   Copyright (C) 2001-2017  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 3.3.2, released 25 Jan 2017.
#
# See http://backuppc.sourceforge.net.
#
#========================================================================

use strict;
no  utf8;
use lib "/usr/local/lib";
use BackupPC::Lib;
use BackupPC::FileZIO;
use BackupPC::Xfer;
use Socket;

use File::Path;
use Getopt::Std;

use vars qw( %RestoreReq );

###########################################################################
# 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($hostIP, $host, $client, $reqFileName, %stat);

$bpc->ChildInit();

if ( @ARGV != 3 ) {
    print("usage: $0 <hostIP> <client> <reqFileName>\n");
    exit(1);
}
$hostIP = $1 if ( $ARGV[0] =~ /(.+)/ );
$client = $1 if ( $ARGV[1] =~ /(.+)/ );
if ( $ARGV[2] !~ /^([\w.]+)$/ ) {
    print("$0: bad reqFileName (arg #3): $ARGV[2]\n");
    exit(1);
}
$reqFileName = $1;

my $startTime = time();

my $Hosts = $bpc->HostInfoRead($client);

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

#
# 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 = $$;

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);

#
# Read the request file
#
if ( !(my $ret = do "$Dir/$reqFileName") ) {
    my $err;
    if ( $@ ) {
        $err = "couldn't parse $Dir/$reqFileName: $@";
    } elsif ( !defined($ret) ) {
	$err = "couldn't do $Dir/$reqFileName: $!";
    } else {
	$err = "couldn't run $Dir/$reqFileName";
    }
    $stat{hostError} = $err;
    exit(RestoreCleanup($client));
}

#
# Re-read config file, so we can include the PC-specific config
#
if ( defined(my $error = $bpc->ConfigRead($client)) ) {
    $stat{hostError} = "Can't read PC's config file: $error";
    exit(RestoreCleanup($client));
}
%Conf = $bpc->Conf();

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

#
# See if the host name is aliased
#
if ( $Conf{ClientNameAlias} ne "" ) {
    $host = $Conf{ClientNameAlias};
} else {
    $host = $client;
}

#
# Find its IP address
#
if ( $hostIP !~ /\d+\.\d+\.\d+\.\d+/ ) {
    if ( !defined(gethostbyname($host)) ) {
	#
	# Ok, NS doesn't know about it.  Maybe it is a NetBios name
	# instead.
	#
	if ( !defined($hostIP = $bpc->NetBiosHostIPFind($host)) ) {
	    $stat{hostError} = "Can't find host $host";
	    exit(RestoreCleanup($client));
	}
    } else {
	$hostIP = $host;
    }
}

#
# Check if $host is alive
#
my $delay = $bpc->CheckHostAlive($hostIP);
if ( $delay < 0 ) {
    $stat{hostError} = "no ping response from $host ($hostIP)";
    exit(RestoreCleanup($client));
} elsif ( $delay > $Conf{PingMaxMsec} ) {
    $stat{hostError} = sprintf("ping too slow: %.4gmsec (max is %gmsec)\n",
                    $delay, $Conf{PingMaxMsec});
    exit(RestoreCleanup($client));
}

#
# Make sure it is really the machine we expect
#
if ( (my $errMsg = CorrectHostCheck($hostIP, $host)) ) {
    $stat{hostError} = $errMsg;
    exit(RestoreCleanup($client));
}

#
# Setup file extension for compression and open RestoreLOG output file
#
if ( $Conf{CompressLevel} && !BackupPC::FileZIO->compOk ) {
    $stat{hostError} = "Compress:Zlib not found";
    exit(RestoreCleanup($client));
}
my $fileExt = $Conf{CompressLevel} > 0 ? ".z" : "";
my $RestoreLOG = BackupPC::FileZIO->open("$Dir/RestoreLOG$fileExt", 1,
                                     $Conf{CompressLevel});
my $tarCreateFileCnt = 0;
my $tarCreateByteCnt = 0;
my $tarCreateDirCnt  = 0;
my $tarCreateErrCnt  = 1;	# assume not ok until we learn otherwise
my $tarCreateErr;
my($logMsg, $xfer);

$stat{xferOK} = $stat{hostAbort} = undef;
$stat{hostError} = $stat{lastOutputLine} = undef;
local(*RH, *WH);

#
# Run an optional pre-restore command
#
UserCommandRun("RestorePreUserCmd");
if ( $? && $Conf{UserCmdCheckStatus} ) {
    $stat{hostError} = "RestorePreUserCmd returned error status $?";
    exit(RestoreCleanup($client));
}
$NeedPostCmd = 1;

$xfer = BackupPC::Xfer::create($Conf{XferMethod}, $bpc);
if ( !defined($xfer) ) {
    my $errStr = BackupPC::Xfer::errStr();
    UserCommandRun("RestorePostUserCmd") if ( $NeedPostCmd );
    $stat{hostError} = $errStr;
    exit(RestoreCleanup($client));
}

my $useTar = $xfer->useTar;

if ( $useTar ) {
    #
    # Create a socketpair to connect BackupPC_tarCreate to the transport
    # program (smbclient, tar, etc).
    # WH is the write handle for writing, provided to BackupPC_tarCreate
    # and RH is the other end of the pipe for reading provided to the
    # transport program.
    #
    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);
    }
}

#
# Run the transport program, which reads from RH and extracts the data.
#
my @Backups = $bpc->BackupInfoRead($RestoreReq{hostSrc});
my $xferArgs = {
    client       => $client,
    host         => $host,
    hostIP       => $hostIP,
    type         => "restore",
    shareName    => $RestoreReq{shareDest},
    pipeRH       => *RH,
    pipeWH       => *WH,
    XferLOG      => $RestoreLOG,
    XferMethod   => $Conf{XferMethod},
    logLevel     => $Conf{XferLogLevel},
    bkupSrcHost  => $RestoreReq{hostSrc},
    bkupSrcShare => $RestoreReq{shareSrc},
    bkupSrcNum   => $RestoreReq{num},
    backups      => \@Backups,
    pathHdrSrc   => $RestoreReq{pathHdrSrc},
    pathHdrDest  => $RestoreReq{pathHdrDest},
    fileList     => $RestoreReq{fileList},
    pidHandler   => \&pidHandler,
};

$xfer->args($xferArgs);

if ( !defined($logMsg = $xfer->start()) ) {
    UserCommandRun("RestorePostUserCmd") if ( $NeedPostCmd );
    $stat{hostError} = "xfer start failed: ", $xfer->errStr;
    exit(RestoreCleanup($client));
}

if ( $useTar ) {
    #
    # Now do the restore by running BackupPC_tarCreate
    #
    # The parent must close the read handle since the transport program
    # is using it.
    #
    close(RH);

    #
    # fork a child for BackupPC_tarCreate.  TAR is a file handle
    # on which we (the parent) read the stderr from BackupPC_tarCreate.
    #
    my @tarPathOpts;
    if ( defined($RestoreReq{pathHdrDest})
		&& $RestoreReq{pathHdrDest} ne $RestoreReq{pathHdrSrc} ) {
	@tarPathOpts = ("-r", $RestoreReq{pathHdrSrc},
			"-p", $RestoreReq{pathHdrDest}
		);
    }
    my @tarArgs = (
	     "-h", $RestoreReq{hostSrc},
	     "-n", $RestoreReq{num},
	     "-s", $RestoreReq{shareSrc},
	     "-t",
	     @tarPathOpts,
	     @{$RestoreReq{fileList}},
    );
    my $runMsg = "Running: "
	       . $bpc->execCmd2ShellCmd("$BinDir/BackupPC_tarCreate", @tarArgs)
	       . "\n";
    $RestoreLOG->write(\$runMsg);
    if ( !defined($tarPid = open(TAR, "-|")) ) {
	close(WH);
	# FIX: need to cleanup xfer
	UserCommandRun("RestorePostUserCmd") if ( $NeedPostCmd );
	$stat{hostError} = "Can't fork to run tar";
	exit(RestoreCleanup($client));
    }
    binmode(TAR);
    if ( !$tarPid ) {
	#
	# This is the tarCreate child.  Clone STDERR to STDOUT,
	# STDOUT to WH, and then exec BackupPC_tarCreate.
	#
	setpgrp 0,0;
	close(STDERR);
	open(STDERR, ">&STDOUT");
	close(STDOUT);
	open(STDOUT, ">&WH");
	alarm(0);
	exec("$BinDir/BackupPC_tarCreate", @tarArgs);
	print(LOG $bpc->timeStamp, "can't exec $BinDir/BackupPC_tarCreate\n");
	# FIX: need to cleanup xfer
	exit(0);
    }
    #
    # The parent must close the write handle since BackupPC_tarCreate
    # is using it.
    #
    close(WH);

    @xferPid = $xfer->xferPid;

    print(LOG $bpc->timeStamp, $logMsg, "\n");
    print("started_restore\n");

    pidHandler(@xferPid);

    #
    # Parse the output of the transfer program and BackupPC_tarCreate
    # while they run.  Since we are 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 ( $FDread =~ /^\0*$/ );
	alarm($Conf{ClientTimeout});
	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;
		if ( !close(TAR) ) {
		    $tarCreateErrCnt  = 1;
		    $tarCreateErr = "BackupPC_tarCreate failed";
		}
	    } else {
		$tarOut .= $mesg;
	    }
	}
	while ( $tarOut =~ /(.*?)[\n\r]+(.*)/s ) {
	    $_ = $1;
	    $tarOut = $2;
	    $RestoreLOG->write(\"tarCreate: $_\n");
	    if ( /^Done: (\d+) files, (\d+) bytes, (\d+) dirs, (\d+) specials, (\d+) errors/ ) {
		$tarCreateFileCnt = $1;
		$tarCreateByteCnt = $2;
		$tarCreateDirCnt  = $3;
		$tarCreateErrCnt  = $5;
	    }
	}
	last if ( !$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;
		last SCAN;
	    }
	}
    }
} else {
    #
    # otherwise the xfer module does everything for us
    #
    print(LOG $bpc->timeStamp, $logMsg . "\n");
    print("started_restore\n");
    ($tarCreateFileCnt, $tarCreateByteCnt,
	$tarCreateErrCnt, $tarCreateErr) = $xfer->run();
}
alarm(0);

#
# Merge the xfer status (need to accumulate counts)
#
my $newStat = $xfer->getStats;
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;
    }
}

exit(RestoreCleanup($client));

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

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;
}

sub catch_signal
{
    my $signame = shift;

    #
    # Children quit quietly on ALRM
    #
    exit(1) if ( $Pid != $$ && $signame eq "ALRM" );

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

    #
    # Note: needs to be tested for each kind of XferMethod
    #
    print(LOG $bpc->timeStamp, "cleaning up after signal $signame\n");
    $SIG{$signame} = 'IGNORE';
    $RestoreLOG->write(\"exiting after signal $signame\n");
    $stat{xferOK} = 0;
    if ( $signame eq "INT" ) {
	$stat{hostError} = "aborted by user (signal=$signame)";
    } else {
	$stat{hostError} = "aborted by signal=$signame";
    }
    exit(RestoreCleanup($client));
}

#
# Cleanup and update the restore status
#
sub RestoreCleanup
{
    my($client) = @_;

    $stat{xferOK} = 0 if ( $stat{hostError} || $stat{hostAbort}
			|| $tarCreateErr );

    if ( !$stat{xferOK} ) {
	#
	# kill off the tranfer program, first nicely then forcefully
	#
	if ( @xferPid ) {
	    kill($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);
	}
    }

    my $lastNum  = -1;
    my @Restores;

    #
    # 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;
    }
    @Restores = $bpc->RestoreInfoRead($client);
    for ( my $i = 0 ; $i < @Restores ; $i++ ) {
	$lastNum = $Restores[$i]{num} if ( $lastNum < $Restores[$i]{num} );
    }
    $lastNum++;

    #
    # Run an optional post-restore command
    #
    if ( $NeedPostCmd ) {
        UserCommandRun("RestorePostUserCmd");
        if ( $? && $Conf{UserCmdCheckStatus} ) {
            $stat{hostError} = "RestorePostUserCmd returned error status $?";
            $stat{xferOK} = 0;
        }
    }

    rename("$Dir/RestoreLOG$fileExt", "$Dir/RestoreLOG.$lastNum$fileExt");
    rename("$Dir/$reqFileName", "$Dir/RestoreInfo.$lastNum");
    my $endTime = time();

    #
    # If the restore failed, clean up
    #
    if ( !$stat{xferOK} ) {
	#
	# wait a short while and see if the system is still alive
	#
	$stat{hostError} ||= $tarCreateErr if ( $tarCreateErr ne "" );
	$stat{hostError} = $stat{lastOutputLine} if ( $stat{hostError} eq "" );
	sleep(2);
	if ( $bpc->CheckHostAlive($hostIP) < 0 ) {
	    $stat{hostAbort} = 1;
	}
	if ( $stat{hostAbort} && $stat{hostError} eq "" ) {
	    $stat{hostError} = "lost network connection during restore";
	}
	$RestoreLOG->write(\"restore failed: $stat{hostError}\n")
					    if ( defined($RestoreLOG) );
    }

    $RestoreLOG->close() if ( defined($RestoreLOG) );

    #
    # Add the new restore information to the restore file
    #
    @Restores = $bpc->RestoreInfoRead($client);
    my $i = @Restores;
    $Restores[$i]{num}           = $lastNum;
    $Restores[$i]{startTime}     = $startTime;
    $Restores[$i]{endTime}       = $endTime;
    $Restores[$i]{result}        = $stat{xferOK} ? "ok" : "failed";
    $Restores[$i]{errorMsg}      = $stat{hostError};
    $Restores[$i]{nFiles}        = $tarCreateFileCnt;
    $Restores[$i]{size}          = $tarCreateByteCnt;
    $Restores[$i]{tarCreateErrs} = $tarCreateErrCnt;
    $Restores[$i]{xferErrs}      = $stat{xferErrCnt} || 0;

    while ( @Restores > $Conf{RestoreInfoKeepCnt} ) {
	my $num = $Restores[0]{num};
	unlink("$Dir/RestoreLOG.$num.z");
	unlink("$Dir/RestoreLOG.$num");
	unlink("$Dir/RestoreInfo.$num");
	shift(@Restores);
    }
    $bpc->RestoreInfoWrite($client, @Restores);

    if ( !$stat{xferOK} ) {
	print(LOG $bpc->timeStamp, "restore failed ($stat{hostError})\n");
	print("restore failed: $stat{hostError}\n");
	return 1;
    } else {
        $stat{xferErrCnt} ||= 0;
	print(LOG $bpc->timeStamp, "restore $lastNum complete"
                . " ($tarCreateFileCnt files, $tarCreateByteCnt bytes,"
                . " $tarCreateDirCnt dirs, $stat{xferErrCnt} xferErrs)\n");
	print("restore complete\n");
	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);
    $RestoreLOG->write(\"Xfer PIDs are now $str\n") if ( defined($RestoreLOG) );
    print("xferPids $str\n");
}

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

    return if ( !defined($Conf{$cmdType}) );
    my $vars = {
        xfer         => $xfer,
        client       => $client,
        host         => $host,
        hostIP       => $hostIP,
        share        => $RestoreReq{shareDest},
        XferMethod   => $Conf{XferMethod},
        sshPath      => $Conf{SshPath},
        LOG          => *LOG,
	user         => $Hosts->{$client}{user},
	moreUsers    => $Hosts->{$client}{moreUsers},
        XferLOG      => $RestoreLOG,
        stat         => \%stat,
        xferOK       => $stat{xferOK} || 0,
	hostError    => $stat{hostError},
	type	     => "restore",
	bkupSrcHost  => $RestoreReq{hostSrc},
	bkupSrcShare => $RestoreReq{shareSrc},
	bkupSrcNum   => $RestoreReq{num},
	backups      => \@Backups,
	pathHdrSrc   => $RestoreReq{pathHdrSrc},
	pathHdrDest  => $RestoreReq{pathHdrDest},
	fileList     => $RestoreReq{fileList},
	cmdType	     => $cmdType,
    };
    my $cmd = $bpc->cmdVarSubstitute($Conf{$cmdType}, $vars);
    $RestoreLOG->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 {
		$RestoreLOG->write(\$_[0]);
	    },
	    $vars, \%Conf);
}
