[ SEA-GHOST MINI SHELL]
#!/usr/local/cpanel/3rdparty/bin/perl
# cpanel - scripts/securetmp Copyright 2022 cPanel, L.L.C.
# All rights reserved.
# copyright@cpanel.net http://cpanel.net
# This code is subject to the cPanel license. Unauthorized copying is prohibited
use strict;
use warnings;
use Cpanel::TempFile ();
use Cpanel::SafeFile ();
use Cpanel::Filesys::FindParse ();
use Cpanel::DiskLib ();
use Getopt::Long;
use Cpanel::Logger ();
use Cpanel::SafeRun::Errors ();
use Cpanel::SafeRun::Simple ();
use Cpanel::Filesys::Mounts ();
my $logger = Cpanel::Logger->new();
$| = 1; ## no critic qw(RequireLocalizedPunctuationVars)
my $has_loop_device = 0;
my $install = 0; # Add securetmp to system startup
my $uninstall = 0; # Remove from system startup
my $auto = 0; # Secure /tmp and /var/tmp
my $daemonize = 1;
my $help = 0;
# Get command line options
GetOptions( 'auto' => \$auto, 'install' => \$install, 'uninstall' => \$uninstall, 'daemonize!' => \$daemonize, 'help' => \$help );
if ($help) {
print <<"MANUAL";
$0 - secure /tmp and /var/tmp
Options:
- auto: skip interactive customization questions
- install: install & enable securetmp service
- uninstall: disable & uninstal securetmp service
- daemonize: run securetmp in background ( default true )
Sample usages:
# run in interactive mode
> $0
# disable interactive mode, run in background
> $0 --auto
# disable interactive mode, do not run in background
> $0 --auto --nodaemonize
MANUAL
exit;
}
if ( -e '/var/cpanel/version/securetmp_disabled' ) {
print "[securetmp] Disabled per /var/cpanel/version/securetmp_disabled\n";
exit;
}
elsif ( -e '/var/cpanel/disabled/securetmp' ) {
print "[securetmp] Disabled per /var/cpanel/disabled/securetmp\n";
exit;
}
elsif ( -e '/var/cpanel/dev_sandbox' ) {
print "[securetmp] Disabled on development sandboxes\n";
exit;
}
# do check for loopback module for Linux based VPS
my @modules = Cpanel::SafeRun::Errors::saferunallerrors('lsmod');
$has_loop_device = check_loop_device();
if ( !grep /loop/, @modules ) {
print "*** Notice *** No loop module detected\n"; # could be built into kernel, so don't bail out yet
print "If the loopback block device is built as a module, try running `modprobe loop` as root via ssh and running this script again.\n";
print "If the loopback block device is built into the kernel itself, you can ignore this message.\n";
}
if ( !$has_loop_device ) {
print "*** Notice *** No working loopback device files found. Try running `modprobe loop` as root via ssh and running this script again.\n";
exit(0);
}
# Start interactive setup
if ( !$auto && !$install && !$uninstall && -t STDIN ) {
print 'Would you like to secure /tmp & /var/tmp at boot time? (y/n) ';
my $answer;
chomp( $answer = <STDIN> );
if ( $answer =~ m/^y/i ) {
$install = 1;
}
else {
print "securetmp will not be added to system startup at this time.\n";
}
undef $answer;
if ( !$install ) {
print 'Would you like to disable securetmp from the system startup? (y/n) ';
chomp( $answer = <STDIN> );
if ( $answer =~ m/^y/i ) {
$uninstall = 1;
}
else {
print "securetmp will not be removed from system startup.\n";
}
undef $answer;
}
print 'Would you like to secure /tmp & /var/tmp now? (y/n) ';
chomp( $answer = <STDIN> );
if ( $answer =~ m/^y/i ) {
$auto = 1;
}
else {
print "/tmp & /var/tmp will not be secured at this time.\n";
}
exit if ( !$install && !$auto && !$uninstall );
}
elsif ( !$auto && !$install && !$uninstall ) {
exit 1;
}
## ADD/REMOVE from startup
#-----------------------------------------------------------------
if ( !-x '/usr/local/cpanel/scripts/cpservice' ) {
$logger->warn("cpservice is not available. Please check its status.");
}
else {
# Remove securetmp from system startup
if ($uninstall) {
Cpanel::SafeRun::Simple::saferun( '/usr/local/cpanel/scripts/cpservice', 'securetmp', 'stop' );
Cpanel::SafeRun::Simple::saferun( '/usr/local/cpanel/scripts/cpservice', 'securetmp', 'disable', '2345' );
Cpanel::SafeRun::Simple::saferun( '/usr/local/cpanel/scripts/cpservice', 'securetmp', 'uninstall' );
}
# Add securetmp to system startup
if ($install) {
Cpanel::SafeRun::Simple::saferun( '/usr/local/cpanel/scripts/cpservice', 'securetmp', 'install' );
Cpanel::SafeRun::Simple::saferun( '/usr/local/cpanel/scripts/cpservice', 'securetmp', 'enable', '35' );
# Do not start securetmp here or it will be run again
}
}
#-----------------------------------------------------------------
# Fork and secure if not called from console
if ( $auto && !-t STDIN && $daemonize ) {
$SIG{'CHLD'} = \&reaper;
print "Setting up /tmp & /var/tmp in the background\n";
exit if fork;
}
elsif ( !$auto ) {
exit;
}
print "Securing /tmp & /var/tmp\n";
# Secure PATH
$ENV{'PATH'} .= ":/sbin:/usr/sbin";
# Global Variables
my $brokenvartmp = 0;
my @vnodes = ();
my $vnodeconfig = '';
my $vnodesrch = '';
my $vnodenumber = 0;
my $tmpmnt = '';
my $vartmpmnt = '';
my $tmpopts = '';
my $vartmpopts = '';
my $mountkeyword = '';
my $cpflags = '';
my $tmpdsksize = 512000; # Must be larger than 250000
$mountkeyword = 'remount';
$cpflags = '-af';
if ( open my $mounts_fh, '<', '/proc/mounts' ) {
while ( my $line = readline $mounts_fh ) {
# must detect: /dev/sda1 /var/tmp\040(deleted) ext2 rw,nosuid,noexec,usrquota 0 0
if ( $line =~ m/^(\S+)\s+([^\s\\\(]+)\S*\s+\S+\s+(\S+)/ ) {
if ( $2 eq '/tmp' ) {
$tmpmnt = $1;
$tmpopts = $3;
}
elsif ( $2 eq '/var/tmp' ) {
$vartmpmnt = $1;
$vartmpopts = $3;
}
if ( $1 =~ /^\/dev\/vn.*/ ) {
push @vnodes, $1;
}
}
if ( $line =~ m/\S+\s+\(deleted\)[^\/]*\/var\/tmp\s+/ ) {
$brokenvartmp = 1;
$vartmpmnt = '';
$vartmpopts = '';
}
}
close $mounts_fh;
}
else {
die "Unable to read /proc/mounts: $!";
}
# Begin securetmp actions
if ( !$tmpmnt ) {
print "Calculating size on /tmp\n";
my $partition_map = {};
my $filesys = Cpanel::DiskLib::get_disk_used_percentage_with_dupedevs();
foreach my $disk ( @{$filesys} ) {
$partition_map->{ $disk->{'mount'} } = $disk->{'available'};
}
my $mount_point = Cpanel::Filesys::FindParse::find_mount( $filesys, '/usr/tmpDSK' );
my $available = $partition_map->{$mount_point};
my $five_percent_of_available = ( $available * 0.05 );
if ( $five_percent_of_available > $tmpdsksize ) {
$tmpdsksize = $five_percent_of_available;
}
my $FOUR_GIG_k = ( 1024 * 1024 * 4 );
if ( $tmpdsksize > $FOUR_GIG_k ) {
$tmpdsksize = $FOUR_GIG_k;
}
$tmpdsksize = int($tmpdsksize);
$tmpdsksize = $tmpdsksize - ( $tmpdsksize % 1024 );
my $tmpdsksize_megs = ( $tmpdsksize / 1024 );
print "/tmp calculated to be $tmpdsksize_megs M based on available disk space in /usr\n";
# Check loop dev on Linux
if ( !$has_loop_device ) {
print "The system does not support loop devices.\n";
if ($brokenvartmp) {
print 'Unmounting orphaned /var/tmp ...';
system 'umount', '/var/tmp';
print "Done\n";
}
exit;
}
if ( -d '/usr/tmpDSK' ) {
rename( '/usr/tmpDSK', '/usr/tmpDSK.move_away.' . $$ . '.' . time() );
}
if ( !-e '/usr/tmpDSK' ) {
print "No separate partition for tmp!\n";
createtmpdisk('/usr/tmpDSK');
}
elsif ( -d '/usr/tmpDSK' ) {
die "/usr/tmpDSK exists as a directory. Please remove and rerun /usr/local/cpanel/scripts/securetmp.\n";
}
# ensure that /usr/tmpDSK is large enough
elsif ( ( -s '/usr/tmpDSK' ) < ( $tmpdsksize * 1024 ) ) {
print "Your /tmp is too small. Rebuilding it now.\n";
system 'rm', '-f', '/usr/tmpDSK';
createtmpdisk('/usr/tmpDSK');
}
else {
print "Everything looks good with your /tmp. Its the right size and ready to go.\n";
}
print 'Setting up /tmp... ';
if ( -e '/usr/tmp.secure' ) {
system 'mv', '-f', '/usr/tmp.secure', '/usr/tmp.secure.cpback';
}
mkdir '/usr/tmp.secure';
archivecopy( '/tmp', '/usr/tmp.secure' );
system 'rm', '-rf', '/tmp';
mkdir '/tmp';
chmod( oct(1777), '/tmp' );
my $mountresult = mounttmpdsk( '/usr/tmpDSK', '/tmp', $tmpopts );
archivecopy( '/usr/tmp.secure/tmp/.', '/tmp' );
chmod( oct(1777), '/tmp' );
system 'rm', '-rf', '/usr/tmp.secure';
if ($mountresult) {
die "There was a problem mounting /tmp: $mountresult";
}
print "Done\n";
}
elsif ( $tmpmnt && $tmpopts !~ m/noexec/ ) {
print 'Securing /tmp... ';
system 'mount', '-o', $mountkeyword . ',noexec,nosuid', $tmpmnt, '/tmp';
print "Done\n";
}
else {
print "/tmp is already secure\n";
}
if ( $brokenvartmp || ( $vartmpmnt && $vartmpopts !~ m/noexec/ ) ) {
print 'Unmounting insecure /var/tmp... ';
system 'umount', '/var/tmp';
$vartmpmnt = '';
$vartmpopts = '';
print "Done\n";
}
if ( !$vartmpmnt ) {
print 'Setting up /var/tmp... ';
if ( !-e '/var/tmp' ) {
mkdir '/var/tmp';
}
elsif ( !-d '/var/tmp' ) {
system 'mv', '/var/tmp', '/var/tmp.cpback';
mkdir '/var/tmp';
}
system 'mount', '-o', 'bind,noexec,nosuid', '/tmp', '/var/tmp';
print "Done\n";
}
else {
print "/var/tmp is already secure\n";
}
my $usingTMPDSK = 0;
if ( -e '/usr/tmpDSK' ) {
my $mount = `mount`;
if ( $mount =~ m/tmpDSK/ ) {
$usingTMPDSK = 1;
}
}
print 'Checking fstab for entries ...';
my $hastmpdsk = 0;
my $hasvartmpdsk = 0;
my $fslock = Cpanel::SafeFile::safeopen( \*FSTAB, '+<', '/etc/fstab' );
if ($fslock) {
while (<FSTAB>) {
if (/^\s*\/usr\/tmpDSK/) { $hastmpdsk = 1; }
if (/^\s*(\S+)\s*\/var\/tmp/) { $hasvartmpdsk = 1; }
}
if ( !$hastmpdsk && $usingTMPDSK ) {
print "Added fstab entry (/tmp)....";
print FSTAB "/usr/tmpDSK /tmp ext4 defaults,noauto 0 0\n";
}
if ( !$hasvartmpdsk && $vartmpmnt ) {
print "Added fstab entry (/var/tmp)....";
print FSTAB "/tmp /var/tmp ext4 defaults,bind,noauto 0 0\n";
}
Cpanel::SafeFile::safeclose( \*FSTAB, $fslock );
print "Done\n";
}
else {
$logger->die("Could not edit /etc/fstab");
}
my $logrotate = '/etc/cron.daily/logrotate';
if ( -e $logrotate ) {
my @logrotate_contents;
my $has_tmpdir = 0;
if ( open my $logrotate_fh, '<', $logrotate ) {
while ( my $line = readline $logrotate_fh ) {
if ( $line =~ m/TMPDIR/ && $line !~ m/^\s*#/ ) {
$has_tmpdir = 1;
last;
}
push @logrotate_contents, $line;
}
close $logrotate_fh;
if ( !$has_tmpdir ) {
my $updated_logrotate = 0;
if ( open my $logrotate_fh, '>', $logrotate ) {
foreach my $line (@logrotate_contents) {
if ( $line =~ m/^#!\/(?:usr|bin)/ ) {
print "Adding TMPDIR setting to /etc/cron.daily/logrotate\n";
print {$logrotate_fh} $line;
print {$logrotate_fh} "export TMPDIR=/var/spool/logrotate/tmp\n";
$updated_logrotate = 1;
}
else {
print {$logrotate_fh} $line;
}
}
close $logrotate_fh;
}
if ($updated_logrotate) {
if ( !-e '/var/spool/logrotate/tmp' ) {
system 'mkdir', '-p', '/var/spool/logrotate/tmp';
}
if ( !-d '/var/spool/logrotate/tmp' ) {
print <<'EOM';
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Logrotate detected and TMPDIR setting updated. The TMPDIR
directory (/var/spool/logrotate/tmp) does not exist!
Logrotate will need to use this directory for execution of
its postrotate scripts. This directory is normally /tmp, but
due to /tmp being set as non-executable an alternative
directory must be specified. Please correct this issue.
See /etc/cron.daily/logrotate to adjust the TMPDIR value for your system.
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
EOM
}
}
else {
warn "Failed to update /etc/cron.daily/logrotate! Logrotate may be corrupt.";
}
}
else {
print "Logrotate TMPDIR already configured\n";
}
}
}
print "Process Complete\n";
Cpanel::Filesys::Mounts::clear_mounts_cache();
exit;
################################################################################
# createtmpdisk
################################################################################
sub createtmpdisk {
my $path = shift;
my $disk_size = shift || $tmpdsksize;
local $ENV{'LC_ALL'} = 'C'; # Force prompt processing to english
print "Building ${path}...";
if ( -e $path ) {
unlink($path);
}
my $disk_size_in_m = int( $disk_size / 1024 ) || 1;
my $bytes = 1024 * 1024 * $disk_size_in_m;
open( my $fh, '>', $path ) or die "Failed to open “$path”: $!";
truncate( $fh, $bytes ) or do {
die "truncate($path, $bytes): $!";
};
close($fh);
open( my $mkfs, "|-" ) || exec( "/sbin/mkfs", $path );
print {$mkfs} "yes\r\n";
close($mkfs);
if ( -e "/sbin/tune2fs" ) {
system( "/sbin/tune2fs", "-j", $path );
}
chmod 0600, $path;
print "Done\n";
return;
}
################################################################################
# archivecopy
################################################################################
sub archivecopy {
my ( $origin, $dest ) = @_;
my $cpflags = '-af';
return system( "cp", $cpflags, $origin, $dest );
}
################################################################################
# mounttmpdsk
################################################################################
sub mounttmpdsk {
my ( $disk_path, $mount_path, $current_mount_opts ) = @_;
$current_mount_opts //= '';
# Try to mount ext4 + discard first; if that fails, let the system detect the filesystem.
if ( $current_mount_opts !~ m/loop/ ) {
if ( system( 'mount', '-t', 'ext4', '-o', 'loop,noexec,nosuid,rw,discard', $disk_path, $mount_path ) ) {
system( 'mount', '-o', 'loop,noexec,nosuid,rw', $disk_path, $mount_path );
}
}
return (0);
}
sub test_loopback_device {
my $loopback_device = shift;
system( 'umount', '/usr/testDSK' );
createtmpdisk( '/usr/testDSK', 10240 );
my $tmpfile = Cpanel::TempFile->new();
my $test_mount_path = $tmpfile->dir();
mounttmpdsk( '/usr/testDSK', $test_mount_path );
my $loopback_status = Cpanel::SafeRun::Errors::saferunallerrors( 'losetup', $loopback_device );
system( 'umount', $test_mount_path );
unlink( '/usr/testDSK', $test_mount_path );
return $loopback_status =~ m/\Q$loopback_device\E:.*\/usr\/testDSK/i ? 1 : 0;
}
sub check_loop_device {
my $loopback_device = Cpanel::SafeRun::Errors::saferunallerrors( 'losetup', '-f' );
chomp $loopback_device;
return if !$loopback_device || !test_loopback_device($loopback_device);
return $loopback_device;
}
################################################################################
# reaper
################################################################################
sub reaper {
my $thedead;
while ( ( $thedead = waitpid( -1, 1 ) ) > 0 ) {
# the dead shall do what ?
}
$SIG{CHLD} = \&reaper;
}
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