#! /usr/bin/perl
#
# Copyright 2002,2003,2004,2005,2007,2009,2010,2011 by Stefan Hornburg (Racke) <racke@linuxia.de>
#
# 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.

use strict;
use warnings;

use File::Basename;
use File::Spec;

my $daemon = '/usr/sbin/pure-ftpd';
my @capabilities = @ARGV;

if ($ARGV[0]) {
	$daemon = "$daemon-$ARGV[0]";
}

# configuration schema
#
# fields of the array:
# 0. option name
# 1. parser
# 2. priority
#
# SysLogFacility has the highest priority, because we want to
# avoid to log to the wrong location (see pure-ftpd manpage).

my %conf = ('AllowAnonymousFXP' => ['-W'],
			'AllowDotFiles' => ['-z'],
			'AllowUserFXP' => ['-w'],
			'AltLog' => ['-O %s', \&parse_string],
			'AnonymousBandwidth' => ['-t %s', \&parse_number_1_2],
			'AnonymousCanCreateDirs' => ['-M'],
			'AnonymousCantUpload' => ['-i'],
			'AnonymousOnly', => ['-e'],
			'AnonymousRatio' => ['-q %d:%d', \&parse_number_2],
			'AntiWarez' => ['-s'],
			'AutoRename' => ['-r'],
			'Bind' => ['-S %s', \&parse_string],
			'BrokenClientsCompatibility' => ['-b'],
			'CallUploadScript' => ['-o'],
			'ChrootEveryone' => ['-A'],
			'CreateHomeDir' => ['-j'],
			'CustomerProof' => ['-Z'],
			'Daemonize' => ['-B'],
			'DisplayDotFiles' => ['-D'],
			'DontResolve' => ['-H'],
			'ForcePassiveIP' => ['-P %s', \&parse_string],
			'FortunesFile' => ['-F %s', \&parse_filename],
			'FSCharset' => ['-8 %s', \&parse_string],
			'ClientCharset' => ['-9 %s', \&parse_string],
			'IPV4Only' => ['-4'],
			'IPV6Only' => ['-6'],
			'KeepAllFiles' => ['-K'],
			'LimitRecursion' => ['-L %d:%d', \&parse_number_2_unlimited],
			'LogPID' => ['-1'],
			'MaxClientsNumber' => ['-c %d', \&parse_number_1],
			'MaxClientsPerIP' => ['-C %d', \&parse_number_1],
			'MaxDiskUsage' => ['-k %d', \&parse_number_1],
			'MaxIdleTime' => ['-I %d', \&parse_number_1],
			'MaxLoad' => ['-m %d', \&parse_number_1],
			'MinUID' => ['-u %d', \&parse_number_1],
			'NATmode' => ['-N'],
			'NoAnonymous' => ['-E'],
			'NoChmod' => ['-R'],
			'NoRename' => ['-G'],
			'NoTruncate' => ['-0'],
			'PassivePortRange' => ['-p %d:%d', \&parse_number_2],
			'PerUserLimits' => ['-y %d:%d', \&parse_number_2],
			'ProhibitDotFilesRead' => ['-X'],
			'ProhibitDotFilesWrite' => ['-x'],
			'Quota' => ['-n %d:%d', \&parse_number_2],
			'SyslogFacility' => ['-f %s', \&parse_word, 99],
			'TLS' => ['-Y %d', \&parse_number_1],
			'TrustedGID' => ['-a %d', \&parse_number_1],
			'TrustedIP' => ['-V %s', \&parse_ip],
			'Umask' => ['-U %s:%s', \&parse_umask],
			'UserBandwidth' => ['-T %s', \&parse_number_1_2],
			'UserRatio' => ['-Q %d:%d', \&parse_number_2],
			'VerboseLog' => ['-d'],
		    );

my %authconf = ('ExtAuth' => ['extauth:%s', \&parse_sockname],
				'LDAPConfigFile' => ['ldap:%s', \&parse_filename, 0,
										 'ldap'],
				'MySQLConfigFile' => ['mysql:%s', \&parse_filename, 0,
									  'mysql'],
				'PGSQLConfigFile' => ['pgsql:%s', \&parse_filename, 0,
									  'postgresql'],
				'PAMAuthentication' => ['pam'],
				'PureDB' => ['puredb:%s', \&parse_filename],
				'UnixAuthentication' => ['unix'],
			   );
				
# examine all configuration files in /etc/pure-ftpd/conf

my @conffiles;

opendir (ETCCONF, '/etc/pure-ftpd/conf') 
	|| die "$0: Couldn't examine directory /etc/pure-ftpd/conf: $!\n";
@conffiles = readdir (ETCCONF);
closedir (ETCCONF);

# examine authentication files in /etc/pure-ftpd/auth

my @authfiles;

opendir (ETCAUTH, '/etc/pure-ftpd/auth') 
	|| die "$0: Couldn't examine directory /etc/pure-ftpd/auth: $!\n";
@authfiles = sort (grep {-l "/etc/pure-ftpd/auth/$_"} readdir (ETCAUTH));
closedir (ETCAUTH);

my ($file, $cref, $name);
my (@options, $option, $ret);

for my $authname (@authfiles) {
	# check if corresponding file exists
	next unless $file = readlink("/etc/pure-ftpd/auth/$authname");
	unless (File::Spec->file_name_is_absolute($file)) {
		$file = File::Spec->catfile('/etc/pure-ftpd/auth',$file);
	}
	next unless -f $file;
	
	# check if configuration directive exists
	$name = basename($file);

	# check if we have the right capability for this authentication method
	next if $authconf{$authname}->[3] && ! grep {$authconf{$authname}->[3] eq $_} @capabilities;
	
	if ($ret = parse_file(\%authconf, $file, $name)) {
		$ret->[0] = "-l $ret->[0]";
		push (@options, $ret);
	}
}


for (@conffiles) {
	# simply skip files with non-word/non-numeric characters
	next unless /^[A-Za-z][A-Za-z0-9]+$/;

	# skip authentication configuration files
	next if exists $authconf{$_};
	
	$file = "/etc/pure-ftpd/conf/$_";
	if ($ret = parse_file(\%conf, $file, $_)) {
		push (@options, $ret);
	}
}

@options = map {split(/ /, $_->[0], 2)} (sort {$b->[1] <=> $a->[1]} @options);

if (exists $ENV{STANDALONE_OR_INETD} && $ENV{STANDALONE_OR_INETD} eq 'standalone') {
	push (@options, '-B');
	print "Running: $daemon ", join (' ', @options), "\n";
}

# force PID file to /var/run/pure-ftpd/pure-ftpd.pid
push(@options, '-g', '/var/run/pure-ftpd/pure-ftpd.pid');

exec { $daemon } ($daemon, @options) or die "$0: Cannot exec $daemon: $!";

sub parse_file {
	my ($cref, $file, $option) = @_;
	my @lines;

	unless (exists $cref->{$option}) {
		die "$0: Invalid configuration file $file: No corresponding directive\n";
	}

	open (FILE, $file)
		|| die "$0: Couldn't open configuration file $file: $!\n";
	while (<FILE>) {
		next unless /\S/;
		s/^\s+//;
		s/\s+$//;
		next if /^\#/;
		push (@lines, $_);
	}
	close (FILE);
	
	# call parser
	for my $line (@lines) {
		my $buf = '';

		if (defined $cref->{$option}->[1]) {
			$ret = $cref->{$option}->[1]->(\$buf, $cref->{$option}->[0], $line);
		} else {
			$ret = parse_yesno(\$buf, $cref->{$option}->[0], $line);
		}
	
		unless ($ret) {
			die "$0: Invalid configuration file $file: $buf\n";
		}

		return [$buf, $cref->{$option}->[2] || 0] if length $buf;
	}

}

sub parse_filename {
	my ($buf, $fmt, $val) = @_;

	unless (-f $val) {
		$$buf = qq{"$val": No such file};
		return;
	}
	$$buf = sprintf $fmt, $val;
	return 1;
}

sub parse_ip {
	my ($buf, $fmt, $val) = @_;

	if ($val =~ /^(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})$/
		&& $1 < 256 && $2 < 256 && $3 < 256 && $4 < 256) {
		$$buf = sprintf $fmt, $val;
		return 1;
	}

	$$buf = qq{"$val": Invalid IP address};
}

sub parse_number_1 {
	my ($buf, $fmt, $val) = @_;

	if ($val =~ /\D/) {
		$$buf = qq{"$val" not a number};
		return;
	}
	
	$$buf = sprintf $fmt, $val;
	return 1;
}

sub parse_number_1_2 {
	my ($buf, $fmt, $val) = @_;

	if ($val =~ /^(\d+)(\s+|:)(\d+)$/) {
		$$buf = sprintf $fmt, "$1:$3";
		return 1;
	}

	if ($val =~ /^(:?\d+)$/ || $val =~ /^(\d+:)/) {
		$$buf = sprintf $fmt, $1;
		return 1;
	}
	
	$$buf = qq{"$val" not one or two numbers};
	return;
}

sub parse_number_2 {
	my ($buf, $fmt, $val) = @_;

	if ($val !~ /^(\d+)\s+(\d+)$/) {
		$$buf = qq{"$val" not two numbers};
		return;
	}
	
	$$buf = sprintf $fmt, $1, $2;
	return 1;
}

sub parse_number_2_unlimited {
	my ($buf, $fmt, $val) = @_;

	if ($val !~ /^(\-?\d+)\s+(\-?\d+)$/) {
		$$buf = qq{"$val" not two numbers};
		return;
	}

	if ($1 < -1 || $2 < -1) {
		$$buf = qq{"$val" smaller than unlimited (-1)};
		return;
	}
	
	$$buf = sprintf $fmt, $1, $2;
	return 1;
}

sub parse_sockname {
	my ($buf, $fmt, $val) = @_;

	unless (-S $val) {
		$$buf = qq{"$val": No such socket};
		return;
	}
	$$buf = sprintf $fmt, $val;
	return 1;
}

sub parse_string {
	my ($buf, $fmt, $val) = @_;

	if ($val =~ /\s/) {
		$$buf = qq{"$val" contains whitespace};
		return;
	}
	
	$$buf = sprintf $fmt, $val;
	return 1;
}

sub parse_umask {
	my ($buf, $fmt, $val) = @_;

	if ($val !~ /^([0-7]{3,3})\s+([0-7]{3,3})$/) {
		$$buf = qq{"$val" not two octal numbers};
		return;
	}
	
	$$buf = sprintf $fmt, $1, $2;
	return 1;
}

sub parse_word {
	my ($buf, $fmt, $val) = @_;

	if ($val !~ /^(\w+)$/) {
		$$buf = qq{"$val" contains non-word characters};
		return;
	}
	
	$$buf = sprintf $fmt, $1;
	return 1;
}

sub parse_yesno {
	my ($buf, $fmt, $val) = @_;
	my @y = ('yes', 1, 'on');
	my @n = ('no', 0, 'off');

	if (grep {$_ eq lc($val)} @y) {
		# result is 'yes'
		$$buf = $fmt;
		return 1;
	}
	if (grep {$_ eq lc($val)} @n) {
		# result is 'no'
		$$buf = '';
		return 1;
	}
	# error
	$$buf = qq{"$val" not convertible to true or false};
	return;
}

__END__

=head1 NAME

pure-ftpd-wrapper - configures and starts Pure-FTPd daemon

=head1 SYNOPSIS

pure-ftpd-wrapper

=head1 DESCRIPTION

B<pure-ftpd-wrapper> reads the configuration for the Pure-FTPd daemon
from files in the directory F</etc/pure-ftpd/conf>. Each file in this
directory is related to a command line option. No more than one
line with configuration values is allowed. Empty lines or lines
starting with the comment character C<#> are discarded.

The Pure-FTPd daemon allows to use different authentication methods
together. The authentication methods are tried in the order they are
specified on the command line. In order to achieve the same flexibility
with files in the F</etc/pure-ftpd> directory, B<pure-ftpd-wrapper>
checks all valid symbolic links within the directory F</etc/pure-ftpd/auth>
in alphabetical order. E.g., a link in this directory pointing to
F</etc/pure-ftpd/conf/PureDB> would enable authentication against
a PureDB database.

There are no means to configure the I<PIDFile> setting, it is hardwired
to /var/run/pure-ftpd/pure-ftpd.pid in this script.

=head1 CONFIGURATION

=head2 Boolean values

The strings C<Yes>,C<1>,C<On> enable the corresponding commandline option
(case doesn't matter). To disable the option use C<No>,C<0> or C<Off>.

Configuration files containing boolean values are C<AllowAnonymousFXP>,
C<AllowDotFiles>, C<AllowUserFXP>, C<AnonymousCanCreateDirs>,
C<AnonymousCantUpload>, C<AnonymousOnly>, C<AntiWarez>, C<AutoRename>,
C<BrokenClientsCompatibility>, C<CallUploadScript>, C<ChrootEveryone>,
C<CreateHomeDir>, C<CustomerProof>, C<Daemonize>, C<DisplayDotFiles>,
C<DontResolve>, C<IPV4Only>, C<IPV6Only>, C<KeepAllFiles>, C<LogPID>,
C<NATmode>, C<NoAnonymous>, C<NoChmod>, C<NoRename>, C<PAMAuthentication>,
C<ProhibitDotFilesRead>, C<ProhibitDotFilesWrite>, C<UnixAuthentication>
and C<VerboseLog>.

=head2 Numerical values

There are several types of numerical values (one number, two numbers,
one or two numbers, two octal numbers).

=over 4

=item One number

C<MaxClientsNumber>, C<MaxClientsPerIP>, C<MaxDiskUsage>, C<MaxIdleTime>,
C<MaxLoad>, C<MinUID>, C<TLS>, C<TrustedGID>.

=item Two numbers

C<AnonymousRatio>, C<LimitRecursion>, C<PassivePortRange>, 
C<PerUserLimits>, C<Quota>, C<UserRatio>.

=item Two numbers (with unlimited value)

This allows -1 in addition to positive numbers indicating an unlimited
values.

C<LimitRecursion>.

=item One or two numbers

C<AnonymousBandwidth>, C<UserBandwidth>.

=item Two octal numbers

C<Umask>.

=back

=head2 String values

=over

=item Arbritrary strings

C<AltLog>, C<Bind>, C<ForcePassiveIP>.

=item Words

C<SyslogFacility>.

=back

=head2 Character Sets

C<FSCharset>, C<ClientCharset>.

=head2 IP values

C<TrustedIP>.

=head2 File values

These values designate an existing file or socket.

=over

=item File

C<FortunesFile>, C<LDAPConfigFile>, C<MySQLConfigFile>, C<PGSQLConfigFile>, C<PureDB>.

=item Socket

C<ExtAuth>.

=back

=head1 AUTHOR

This manual page was written by Stefan Hornburg (Racke) <racke@linuxia.de>
for the Debian GNU/Linux system.