#!/bin/perl -T
#============================================================= -*-perl-*-
#
# BackupPC_restore: Restore files to a client.
#
# DESCRIPTION
#
#   Usage: BackupPC_restore <hostIP> <host> <reqFileName>
#
# AUTHOR
#   Craig Barratt  <cbarratt@users.sourceforge.net>
#
# COPYRIGHT
#   Copyright (C) 2001  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 1.5.0, released 2 Aug 2002.
#
# See http://backuppc.sourceforge.net.
#
#========================================================================

use strict;
use lib "__INSTALLDIR__/lib";
use BackupPC::Lib;
use BackupPC::FileZIO;
use BackupPC::Xfer::Smb;
use BackupPC::Xfer::Tar;

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($hostIP, $host, $reqFileName);

$bpc->ChildInit();

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

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

#
# Re-read config file, so we can include the PC-specific config
#
$bpc->ConfigRead($host);
%Conf = $bpc->Conf();

my $Dir     = "$TopDir/pc/$host";
my $xferPid = -1;
my $tarPid  = -1;

#
# Catch various signals
#
$SIG{INT}  = \&catch_signal;
$SIG{ALRM} = \&catch_signal;
$SIG{TERM} = \&catch_signal;

#
# Read the request file
#
if ( !(my $ret = do "$Dir/$reqFileName") ) {
   die "couldn't parse $Dir/$reqFileName: $@" if $@;
   die "couldn't do $Dir/$reqFileName: $!"    unless defined $ret;
   die "couldn't run $Dir/$reqFileName";
}

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

mkpath($Dir, 0, 0777) if ( !-d $Dir );
if ( !-f "$Dir/LOCK" ) {
    open(LOCK, ">$Dir/LOCK") && close(LOCK);
}
open(LOG, ">>$Dir/LOG");
select(LOG); $| = 1; select(STDOUT);

#
# 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");
    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});
    exit(1);
}

#
# Make sure it is really the machine we expect
#
if ( (my $errMsg = CorrectHostCheck($hostIP, $host)) ) {
    print(LOG $bpc->timeStamp, "restore failed: $errMsg\n");
    print("restore failed: $errMsg\n");
    exit(1);
}

#
# Setup file extension for compression and open RestoreLOG output file
#
$Conf{CompressLevel} = 0 if ( !BackupPC::FileZIO->compOk );
my $fileExt = $Conf{CompressLevel} > 0 ? ".z" : "";
my $RestoreLOG = BackupPC::FileZIO->open("$Dir/RestoreLOG$fileExt", 1,
                                     $Conf{CompressLevel});
my $startTime = time();

my $tarCreateFileCnt = 0;
my $tarCreateByteCnt = 0;
my $tarCreateErrCnt  = 1;	# assume not ok until we learn otherwise
my $tarCreateErr;
my($logMsg, %stat, $xfer);

#
# Now do the restore
#
local(*RH, *WH);

$stat{xferOK} = $stat{hostAbort} = undef;
$stat{hostError} = $stat{lastOutputLine} = undef;

#
# Create a pipe 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.
#
pipe(RH, WH);

#
# Run the transport program, which reads from RH and extracts the data.
#
my $xferArgs = {
    host      => $host,
    hostIP    => $hostIP,
    type      => "restore",
    shareName => $RestoreReq{shareDest},
    pipeRH    => *RH,
    pipeWH    => *WH,
    XferLOG   => $RestoreLOG,
};
if ( $Conf{XferMethod} eq "tar" ) {
    #
    # Use tar (eg: tar/ssh) as the transport program.
    #
    $xfer = BackupPC::Xfer::Tar->new($bpc, $xferArgs);
} else {
    #
    # Default is to use smbclient (smb) as the transport program.
    #
    $xfer = BackupPC::Xfer::Smb->new($bpc, $xferArgs);
}
if ( !defined($logMsg = $xfer->start()) ) {
    print(LOG $bpc->timeStamp, $xfer->errStr, "\n");
    print($xfer->errStr, "\n");
    exit(1);
}
#
# 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 $logMsg = "Running: $BinDir/BackupPC_tarCreate "
                  . join(" ", @tarArgs) . "\n";
$RestoreLOG->write(\$logMsg);
if ( !defined($tarPid = open(TAR, "-|")) ) {
    print(LOG $bpc->timeStamp, "can't fork to run tar\n");
    print("can't fork to run tar\n");
    close(WH);
    # FIX: need to cleanup xfer
    exit(0);
}
if ( !$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");
    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, $logMsg, " (tarPid=$tarPid, xferPid=$xferPid)\n");
print("started restore, tarPid=$tarPid, xferPid=$xferPid\n");

#
# 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 ( $FDread =~ /^\0*$/ );
    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;
	    $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;
        }
    }
}

#
# 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;
    }
}
$RestoreLOG->close();
$stat{xferOK} = 0 if ( $stat{hostError} || $stat{hostAbort} || $tarCreateErr );

if ( !$stat{xferOK} ) {
    #
    # kill off the tranfer program, first nicely then forcefully
    #
    kill(2, $xferPid);
    sleep(1);
    kill(9, $xferPid);
    #
    # kill off the tar process, first nicely then forcefully
    #
    kill(2, $tarPid);
    sleep(1);
    kill(9, $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 = $bpc->RestoreInfoRead($host);
for ( my $i = 0 ; $i < @Restores ; $i++ ) {
    $lastNum = $Restores[$i]{num} if ( $lastNum < $Restores[$i]{num} );
}
$lastNum++;
rename("$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 "" );
    if ( $stat{hostError} ) {
        print(LOG $bpc->timeStamp,
                  "Got fatal error during xfer ($stat{hostError})\n");
    }
    sleep(2);
    if ( $bpc->CheckHostAlive($hostIP) < 0 ) {
        $stat{hostAbort} = 1;
    }
    if ( $stat{hostAbort} ) {
        $stat{hostError} = "lost network connection during restore";
    }
}

#
# Add the new restore information to the restore file
#
@Restores = $bpc->RestoreInfoRead($host);
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);
}
$bpc->RestoreInfoWrite($host, @Restores);

if ( !$stat{xferOK} ) {
    print(LOG $bpc->timeStamp, "Restore aborted ($stat{hostError})\n");
    print("restore failed: $stat{hostError}\n");
} else {
    print("restore complete\n");
}

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

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