#!/usr/local/cpanel/3rdparty/bin/perl

# cpanel - scripts/reset_mail_quotas_to_sane_values
#                                                  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::LoadFile                ();
use Cpanel::PwCache::Helpers        ();
use Cpanel::PwCache::Build          ();
use Cpanel::Usage                   ();
use Cpanel::PwCache                 ();
use Cpanel::AccessIds::SetUids      ();
use Cpanel::Config::LoadCpUserFile  ();
use Cpanel::Config::HasCpUserFile   ();
use Cpanel::Config::Users           ();
use Cpanel::Config::LoadUserDomains ();
use Cpanel::SafeFile                ();
use Cpanel::Email::Maildir          ();

my $version = '1.1';
my $verbose = 0;
my $confirm = 0;
my $force   = 0;

# Max quota is actually 1 byte less than get_max_email_quota
# but we'll silently fix the 1 byte issue below
my $max_quota = Cpanel::Email::Maildir::get_max_email_quota();

# Argument processing
my %opts = (
    'verbose' => \$verbose,
    'confirm' => \$confirm,
    'force'   => \$force,
);

Cpanel::Usage::wrap_options( \@ARGV, \&usage, \%opts );

if ( $> == 0 && !$confirm ) {
    print "Must specify \"--confirm\" to begin. Please read and understand the usage.\n\n";
    usage(1);
}
umask(0077);    # Keep maildirsize file perms consistent with Exim

my $pwcache_ref;
my %CPUSERS;
my $saveversion     = 0;
my $suid            = 0;
my $userdomains_ref = {};

if ( $> == 0 ) {
    $suid = 1;
    Cpanel::PwCache::Helpers::no_uid_cache();    #uid cache only needed if we are going to make lots of getpwuid calls

    Cpanel::PwCache::Build::init_passwdless_pwcache();
    $pwcache_ref = Cpanel::PwCache::Build::fetch_pwcache();
    my $users_arr_ref = Cpanel::Config::Users::getcpusers();
    $userdomains_ref = Cpanel::Config::LoadUserDomains::loaduserdomains( {}, 0, 1 );

    %CPUSERS = map { $_ => undef } @{$users_arr_ref};
    if ( @ARGV && $ARGV[$#ARGV] !~ m/^-/ ) {
        if ( exists $CPUSERS{ $ARGV[$#ARGV] } ) {
            %CPUSERS = ( $ARGV[$#ARGV] => 1 );    #only do one user
        }
        else {
            %CPUSERS = ();
        }
    }
    my $last_version = Cpanel::LoadFile::loadfile('/var/cpanel/version/reset_mail_quotas_to_sane_values') || '';
    if ( $last_version eq $version && !$force ) {
        print "You must use --force to run this utility once it has already been run.\n";
        exit 1;
    }
    $saveversion = 1;
}
else {
    $confirm = 1;
    my @PW = Cpanel::PwCache::getpwuid($>);
    $pwcache_ref = [ \@PW ];
    %CPUSERS     = ( $PW[0] => 1 );

    my @DOMAINS;
    if ( Cpanel::Config::HasCpUserFile::has_cpuser_file( $PW[0] ) ) {
        my $user_info = Cpanel::Config::LoadCpUserFile::loadcpuserfile( $PW[0] );    #we want to load the default so we can use the storable cache
        @DOMAINS = ( $user_info->{'DOMAIN'} );
        if ( ref $user_info->{'DOMAINS'} ) {
            push @DOMAINS, @{ $user_info->{'DOMAINS'} };
        }
    }
    $userdomains_ref->{ $PW[0] } = \@DOMAINS;
}

my ( $user, $useruid, $usergid, $homedir );
foreach my $pwref (@$pwcache_ref) {
    ( $user, $useruid, $usergid, $homedir ) = (@$pwref)[ 0, 2, 3, 7 ];
    next if ( !exists $CPUSERS{$user} );
    if ( !$homedir || !-d $homedir ) {
        print "Skipping $user\n (no home directory)\n";
        next;
    }

    #All the domains
    my @DOMAINS = ref $userdomains_ref->{$user} ? @{ $userdomains_ref->{$user} } : ();
    my @needs_cleanup;
    foreach my $domain (@DOMAINS) {
        if ( -f $homedir . '/etc/' . $domain . '/quota' && -s _ ) {
            push @needs_cleanup, $domain;
        }
    }

    if ( !@needs_cleanup ) {
        if ($verbose) {
            print "Skipping $user as no domains have a quota file.\n";
        }
        next;
    }

    #only fork+setuid if we have something do to
    if ( my $pid = fork() ) {
        waitpid( $pid, 0 );
    }
    else {
        if ($suid) {
            Cpanel::PwCache::Build::pwclearcache();
            Cpanel::AccessIds::SetUids::setuids( $useruid, $usergid ) || die "Could not setuid to $user";
        }

        foreach my $domain (@needs_cleanup) {
            next if ( !$domain );
            normalize_domain_quota( $homedir, $domain, 1 );
        }
        exit;
    }
}

if ($saveversion) {
    if ( open( my $v_fh, '>', '/var/cpanel/version/reset_mail_quotas_to_sane_values' ) ) {
        print {$v_fh} $version;
        close($v_fh);
    }
}

sub normalize_domain_quota {
    my ( $homedir, $domain, $skip_check_existance ) = @_;
    my $dir = $homedir . '/etc/' . $domain;

    if ( !$skip_check_existance ) {
        return 0 if !-f $dir . '/quota' || -z _;
    }
    my %quota_by_user;
    my $altered  = 0;
    my $safelock = Cpanel::SafeFile::safeopen( \*QUOTAFH, '+<', $dir . '/quota' );
    if ($safelock) {
        while ( my $line = readline( \*QUOTAFH ) ) {
            chomp $line;
            my ( $user, $quota ) = split( /:/, $line, 2 );

            next if !$user || !$quota;

            # Quota values above 2GB will be converted to unlimited
            if ( ( int $quota ) > $max_quota ) {
                print "Quota for user $user\@$domain exceedes maximum of $max_quota.  Quota removed.\n" if $verbose;
                $altered = 1;
                next;
            }

            # Remove 1 byte for quota values equal to 2GB
            if ( ( int $quota ) == $max_quota ) {
                $quota   = $max_quota - 1;
                $altered = 1;
            }
            $quota_by_user{$user} = $quota;
        }
        seek( QUOTAFH, 0, 0 );

        if ($altered) {
            print "Updated quota file for $domain.\n" if $verbose;
            if ( scalar keys %quota_by_user ) {
                print QUOTAFH join( "\n", map { $_ . ':' . $quota_by_user{$_} } keys %quota_by_user ) . "\n";
            }
            truncate( QUOTAFH, tell(QUOTAFH) );
        }
        Cpanel::SafeFile::safeclose( \*QUOTAFH, $safelock );
        return 1;
    }
    return 0;
}

sub usage {
    my ($exit) = @_;
    $exit = $exit ? 1 : 0;

    print <<'EOM';
Usage: reset_mail_quotas_to_sane_values <modifier> <user>

This utility regenerates quota files and removes any quotas
above the maximum allowed size of : $max_size

Modifier Flags:
    --force - This required flag indicates that the utility
        should be run even if it has already been run in the past

    --confirm - This required flag indicates that the utility
        should proceed to regenerate the quota files
        based upon the provided options. It is required for
        normal operation.

    --verbose - This optional flag turns on verbose mode for
        enhanced activity reporting to STDOUT.

    --help - display this message and exit.

EOM
    exit $exit;
}