Mini Shell

#!/usr/local/cpanel/3rdparty/bin/perl
# cpanel - scripts/check_users_my_cnf               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::PwCache::PwEnt ();
use Cpanel::PwCache        ();
use Cpanel::AccessIds      ();
use Getopt::Param          ();

use Cpanel::DBI::Mysql          ();
use Cpanel::MysqlUtils::Running ();

my $prm = Getopt::Param->new(
    {
        'help_coderef' => sub {
            print <<"END_USAGE";
Check users for ~/.my.cnf files that do not work and disable them. By default it only has output when a bad ~/.my.cnf is detected.
  $0 --help       - this screen
  $0 --verbose    - Display verbose information about the user's being checked and ~/.my.cnf status.
  $0 --dryrun     - do not disable an invalid ~/.my.cnf just report the problem
  $0 --user=USERA [--user=USERB} - specify a user (or users by using more than one --user flag) to check instead of checking all users
  $0 --perm-only - Do not test the connectivity, only do the mode and ownership check.

END_USAGE
            exit;
        },
    }
);

my %users;
@users{ $prm->param('user') } = ();

my $hasuser = $prm->param('user')      ? 1 : 0;
my $verbose = $prm->param('verbose')   ? 1 : 0;
my $dryrun  = $prm->param('dryrun')    ? 1 : 0;
my $justprm = $prm->param('perm-only') ? 1 : 0;

_mysql_is_up_or_stop() if !$justprm;

my $root_home = ( Cpanel::PwCache::getpwnam('root') )[7];
my @PW;

Cpanel::PwCache::PwEnt::setpwent();

sub _iterate_pw {    ## no critic qw(ProhibitExcessComplexity)
    while ( @PW = Cpanel::PwCache::PwEnt::getpwent() ) {
        next if $hasuser && !exists $users{ $PW[0] };

        print "Starting '$PW[0]' ...\n" if $verbose;
        my $file = "$PW[7]/.my.cnf";
        if ( -e $file ) {

            # if ( chdir $PW[7] ) {
            my $check = sub {

                # untaint
                my ($_file) = $file =~ m{(.*)};

                # check perms before connectivity test since bad perms can prevent connection
                # Warning: World-writable config file '/root/.my.cnf' is ignored
                my ( $mode, $uid, $gid ) = ( stat($_file) )[ 2, 4, 5 ];
                my $perm = sprintf( '%04o', $mode & 07777 );

                # ? only check-for and remove world-writableness ?
                # if worldly
                if ( $mode & 0007 ) {
                    my $newmode = $mode & ~007;                          # remove wordlyness
                    my $newperm = sprintf( '%04o', $newmode & 07777 );
                    if ($dryrun) {
                        print "\tLeaving mode at '$perm' as per --dryrun flag.\n";
                    }
                    else {
                        print "\tChanging $_file\'s mode from '$perm' to '$newperm'.\n" if $verbose;
                        chmod( $newmode, $_file ) or print "\tCould not chmod() '$_file' to '$newperm': $!\n";
                    }
                }

                if ( $uid != $PW[2] || $gid != $PW[3] ) {
                    warn("Ownership of '$_file' is '$uid:$gid' and it should probably be '$PW[2]:$PW[3]'.");
                }

                my $dbh = eval {
                    Cpanel::DBI::Mysql->connect(
                        { mysql_read_default_file => $_file },
                    );
                };

                if ($dbh) {
                    print "\tThe file '$_file' is valid.\n" if $verbose;
                    return 1;
                }

                print "\tThe file '$_file' is invalid:\n\t\t$@\n";

                return;
            };

            my $disable = sub {

                # untaint
                my ($_file) = $file =~ m{(.*)};

                if ($dryrun) {
                    print "\tLeaving file in place as per --dryrun flag.\n";
                }
                else {
                    require Cpanel::Time::ISO;

                    # TODO: rewrite with auth data commented out
                    my $rename_to = "$_file.$$." . Cpanel::Time::ISO::unix2iso();

                    if ( rename $_file => $rename_to ) {
                        print "Successfully renamed “$_file” to “$rename_to”.\n";
                    }
                    else {
                        print "\tFailed to rename “$_file” to “$rename_to”: $!\n";
                    }
                }
            };

            # for entries like this: operator:x:11:0:operator:/root:/sbin/nologin
            if ( $PW[2] != 0 && $PW[7] eq $root_home ) {
                print "\tnon-root user with root's homedir detected, skipping\n" if $verbose;
            }
            else {
                if ($justprm) {
                    print "\tSkipping connectivity test as per --perm-only flag.\n" if $verbose;
                }
                else {
                    if ( $PW[2] == 0 ) {
                        my $rc = $check->();
                        if ( !$rc ) {
                            _mysql_is_up_or_stop();
                            $disable->();
                        }
                    }
                    else {
                        my $rc = Cpanel::AccessIds::do_as_user( $PW[0], $check );
                        if ( !$rc ) {
                            _mysql_is_up_or_stop();    # detect false positive from when mysql is down, needs run as root
                            Cpanel::AccessIds::do_as_user( $PW[0], $disable );
                        }
                    }
                }
            }

            # }
            # else {
            #     print "\tCould not change into directory '$PW[7]': $!\n";
            # }
        }
        else {
            print "\tThe file '$file' does not exist.\n" if $verbose;
        }
        print " ... Done.\n" if $verbose;
    }

    return;
}

_iterate_pw();

Cpanel::PwCache::PwEnt::endpwent();

sub _mysql_is_up_or_stop {

    die "MySQL is not available.\n" if !Cpanel::MysqlUtils::Running::is_mysql_running();

    return;
}