#! /usr/bin/perl -w
# 
# $Id$
# External mount command for mount(8) to interface lufsd(1)
# Copyright (C) 2003 Jan Kratochvil <project-captive@jankratochvil.net>
# 
# 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; exactly version 2 of June 1991 is required
# 
# 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


use strict;
use Carp qw(cluck confess);
use Getopt::Long;
# Do not use any non-core Perl modules here.
# Be perl-5.0 compatible (is it needed if we require Linux kernel >= 2.4 ?)


my $vardir='@localstatedir@/lib/captive';
$vardir=~s#\$\Q{prefix}\E#'@prefix@';#ge;
$vardir="/var/lib/captive" if $vardir=~/^@/;
my $lufsd_bin='@PATH_LUFSD@';
$lufsd_bin="/usr/bin/lufsd" if $lufsd_bin=~/^@/;
my $captive_sandbox_server_bin='@libexecdir@/captive-sandbox-server';
$captive_sandbox_server_bin=~s#\$\Q{exec_prefix}\E#'@exec_prefix@';#ge;
$captive_sandbox_server_bin=~s#\$\Q{prefix}\E#'@prefix@';#ge;
$captive_sandbox_server_bin="/usr/libexec/captive-sandbox-server" if $captive_sandbox_server_bin=~/^@/;


my $ME=($0=~m#([^/]*)$#)[0] or die "Cannot detetect my basename from: $0";
my $fsname=$ME;
$fsname=~s/^mount[.]captive-// or die "Cannot detect captive filesystem module from my name: $fsname";
my $image=shift @ARGV or die "Missing argv[1]: device or image pathname";
-r $image or die "Image pathname not readable: $image";
warn "warning: '-o loop' is not neccessary for Captive filesystem mounts"
		if $image=~m#^/dev/loop#;
my $dir=shift @ARGV or die "Missing argv[2]: mount point directory";
-d $dir or die "Mount point directory not a valid directory: $dir";
shift @ARGV if my $nomtab =$ARGV[0] && $ARGV[0] eq "-n";
shift @ARGV if my $verbose=$ARGV[0] && $ARGV[0] eq "-v";
my $oo="";
do { shift @ARGV; $oo=shift @ARGV; } if $ARGV[0] && $ARGV[0] eq "-o";
die "Excessive arguments: @ARGV" if @ARGV;

sub die_install
{
	die
"You should run captive-install-acquire(1) of 'captive-install' package,
otherwise you can also acquire this file from URL:
http://www.microsoft.com/WindowsXP/pro/downloads/servicepacks/sp1/checkedbuild.asp
";
}

my $filesystem=$vardir."/".$fsname.".sys";
if (!-r $filesystem) {
	warn "W32 filesystem .sys module not found: $filesystem";
	die_install();
	}
my $ntoskrnl=$vardir."/ntoskrnl.exe";
if (!-r $ntoskrnl) {
	warn "W32 ntoskrnl.exe not found: $ntoskrnl";
	die_install();
	}

# Keep @opt_captive ordering
# to let the options be overridable by user (such as 'ro').
my @opt_captive=();
my @opt_lufs=();
my $opt_force;
my $opt_rwmode="--blind";
for (split /,/,$oo) {
	$_="--$_" if $_ eq "ro" || $_ eq "rw";
	$opt_rwmode=$_ if /^--(?:ro|rw|blind)$/;
	$opt_force=1 if $_ eq "force";
	push @opt_captive,$_ if  /^--/;
	push @opt_lufs,$_    if !/^--/;
	}

# Shameless advertisement:
if ($fsname eq "ntfs") {
	for my $fh (*STDERR,*STDOUT) {
		if (-t $fh) {
			print $fh 'Captive NTFS v@VERSION@.  Check a new version at: http://www.jankratochvil.net/'."\n";
			last;
			}
		}
	}

if (!$opt_force) {
	local *MTAB;
	if (!open MTAB,"/etc/mtab") {
		warn "Cannot open /etc/mtab: $!";
		}
	else {
		local $/=undef();
		my $mtab=<MTAB>;
		close MTAB;
		die ""
						."$ME: $image already mounted\n"
						."$ME: according to mtab, $image is mounted on $1\n"
						."$ME: Use '-o force' to mount the image notwithstanding.\n"
				if $mtab=~/^\Q$image\E\s+(\S+)/m;
		}
	}

$oo=""
		."fs=captivefs,"
		."mntent.mnt_fsname=$image,mntent.mnt_type=captive-$fsname,"	# Double-dashes forbidden.
		."dir_cache_entries=0,"
		."image=$image,"
		.join(",",@opt_lufs).","
		."captive_options="
				.($fsname eq "cdfs" ? "--cdrom;--ro;" : "--disk;--rw;")
				."--load-module=$ntoskrnl;--filesystem=$filesystem;"
				."--sandbox-server=$captive_sandbox_server_bin;"
				."--bug-pathname=$vardir/bug-%FT%T.captivebug.xml.gz;"
				."--syslog;"
				.join(";",@opt_captive);

warn "$0: '-n' not supported - ignored" if $nomtab;

# Use "'$oo'" to permit another expansion by bash(1) during lufsmnt(8) execution.
my @argv=($lufsd_bin,"none",$dir,"-o",$oo);

print STDERR "$0: @argv\n" if $verbose;
exec $lufsd_bin @argv;
die "Failed to execute: @argv";