# mysql-lib.pl
# Common MySQL functions

BEGIN { push(@INC, ".."); };
use WebminCore;
&init_config();

require 'view-lib.pl';
if ($config{'mysql_libs'}) {
	$ENV{$gconfig{'ld_env'}} .= ':' if ($ENV{$gconfig{'ld_env'}});
	$ENV{$gconfig{'ld_env'}} .= $config{'mysql_libs'};
	}
if ($config{'mysql'} =~ /^(\S+)\/bin\/mysql$/ && $1 ne '' && $1 ne '/usr') {
	$ENV{$gconfig{'ld_env'}} .= ':' if ($ENV{$gconfig{'ld_env'}});
	$ENV{$gconfig{'ld_env'}} .= "$1/lib";
	}
if ($module_info{'usermin'}) {
	# Usermin always runs this module as the logged-in Unix user.
	# %access is faked up to prevent attempts to create and delete DBs
	&switch_to_remote_user();
	&create_user_config_dirs();
	%access = ( 'create', 0,
	            'delete', 0,
	            'bpath', '/',
	            'buser', 'root',
	            'edonly', 0 );
	if ($config{'useident'} ne 'yes') {
		$mysql_login = $userconfig{'login'};
		$mysql_pass = $userconfig{'pass'};
		}
	chop($mysql_version = &read_file_contents(
		"$user_module_config_directory/version"));
	$max_dbs = $userconfig{'max_dbs'};
	$commands_file = "$user_module_config_directory/commands";
	$sql_charset = $userconfig{'charset'};
	%displayconfig = %userconfig;
	}
else {
	# Webmin connects to the database as the user specified in the per-user
	# or global config
	%access = &get_module_acl();
	if ($access{'user'} && !$use_global_login) {
		$mysql_login = $access{'user'};
		$mysql_pass = $access{'pass'};
		}
	else {
		$mysql_login = $config{'login'};
		$mysql_pass = $config{'pass'};
		}
	chop($mysql_version = &read_file_contents(
		"$module_config_directory/version"));
	$mysql_version ||= &get_mysql_version();
	$cron_cmd = "$module_config_directory/backup.pl";
	$max_dbs = $config{'max_dbs'};
	$commands_file = "$module_config_directory/commands";
	$sql_charset = $config{'charset'};
	%displayconfig = %config;
	}
$authstr = &make_authstr();
$master_db = 'mysql';
$password_func = $config{'passwd_mode'} ? "old_password" : "password";

@type_list = ('tinyint', 'smallint', 'mediumint', 'int', 'bigint',
	    'float', 'double', 'decimal', 'date', 'datetime', 'timestamp',
	    'time', 'year', 'char', 'varchar', 'tinyblob', 'tinytext',
	    'blob', 'text', 'mediumblob', 'mediumtext', 'longblob', 'longtext',
	    'enum', 'set');

@priv_cols = ('Host', 'User', 'Password', 'Select_priv', 'Insert_priv', 'Update_priv', 'Delete_priv', 'Create_priv', 'Drop_priv', 'Reload_priv', 'Shutdown_priv', 'Process_priv', 'File_priv', 'Grant_priv', 'References_priv', 'Index_priv', 'Alter_priv', 'Show_db_priv', 'Super_priv', 'Create_tmp_table_priv', 'Lock_tables_priv', 'Execute_priv', 'Repl_slave_priv', 'Repl_client_priv', 'Create_view_priv', 'Show_view_priv', 'Create_routine_priv', 'Alter_routine_priv', 'Create_user_priv');

if (!$config{'nodbi'}) {
	# Check if we have DBI::mysql
	eval <<EOF;
use DBI;
\$driver_handle = DBI->install_driver("mysql");
EOF
}

# Fix text if we're running MariaDB
sub fix_mysql_text
{
my ($text) = @_;
if ($mysql_version =~ /mariadb/i) {
	foreach my $t (keys %$text) {
		$text->{$t} =~ s/MySQL/MariaDB/g;
		}
	}
}
&fix_mysql_text(\%text);

if (&compare_version_numbers($mysql_version, "5.5") >= 0) {
	@mysql_set_variables = ( "key_buffer_size", "sort_buffer_size",
				 "net_buffer_length" );
	}
else {
	@mysql_set_variables = ( "key_buffer", "sort_buffer",
				 "net_buffer_length" );
	}
if (&compare_version_numbers($mysql_version, "5.6") >= 0) {
	@mysql_number_variables = ( "table_open_cache", "max_connections" );
	}
else {
	@mysql_number_variables = ( "table_cache", "max_connections" );
	}
@mysql_byte_variables = ( "max_allowed_packet" );
my $mysql8_optout = &compare_version_numbers($mysql_version, "8.0") >= 0 && $mysql_version !~ /maria/i;
if (!$mysql8_optout) {
	# Removed options in MySQL 8 #1561
	push(@mysql_byte_variables, "query_cache_size");
	}
if (&compare_version_numbers($mysql_version, "5") >= 0) {
	push(@mysql_byte_variables, "myisam_sort_buffer_size");
	}
else {
	push(@mysql_set_variables, "myisam_sort_buffer_size");
	}

# make_authstr([login], [pass], [host], [port], [sock], [unix-user], [ssl])
# Returns a string to pass to MySQL commands to login to the database
sub make_authstr
{
local $login = defined($_[0]) ? $_[0] : $mysql_login;
local $pass = defined($_[1]) ? $_[1] : $mysql_pass;
local $host = defined($_[2]) ? $_[2] : $config{'host'};
local $port = defined($_[3]) ? $_[3] : $config{'port'};
local $sock = defined($_[4]) ? $_[4] : $config{'sock'};
local $unix = $_[5];
local $ssl = defined($_[6]) ? $_[6] : $config{'ssl'};
local $supp = &supports_env_pass($unix, $pass);
if ($supp) {
	$make_authstr_pass = $pass;
	}
else {
	$make_authstr_pass = undef;
	}
&set_authstr_env();
return ($sock ? " -S $sock" : "").
       ($host ? " -h $host" : "").
       ($port ? " -P $port" : "").
       ($login ? " -u ".quotemeta($login) : "").
       ($ssl ? " --ssl" : "").
       ($supp ? "" :    # Password comes from environment
        $pass && &compare_version_numbers($mysql_version, "4.1") >= 0 ?
	" --password=".quotemeta($pass) :
        $pass ? " -p".quotemeta($pass) : "");
}

# set_authstr_env()
# Set any environment variables that make_authstr requires
sub set_authstr_env
{
if (defined($make_authstr_pass)) {
	$ENV{'MYSQL_PWD'} = $make_authstr_pass;
	}
else {
	delete($ENV{'MYSQL_PWD'});
	}
}

# is_mysql_running()
# Returns 1 if mysql is running, 0 if not, or -1 if running but
# inaccessible without a password. When called in an array context, also
# returns the full error message
sub is_mysql_running
{
# First type regular connection
if ($driver_handle && !$config{'nodbi'}) {
	local $main::error_must_die = 1;
	local ($data, $rv);
	eval { $data = &execute_sql_safe(undef, "select version()"); };
	local $err = $@;
	$err =~ s/\s+at\s+\S+\s+line.*$//;
	if ($@ =~ /denied|password/i) {
		$rv = -1;
		}
	elsif ($@ =~ /connect/i) {
		$rv = 0;
		}
	elsif ($data->{'data'}->[0]->[0] =~ /^\d/) {
		$rv = 1;
		}
	if (defined($rv)) {
		return wantarray ? ( $rv, $err ) : $rv;
		}
	}

# Fall back to mysqladmin command
local $out = &backquote_command(
	"\"$config{'mysqladmin'}\" $authstr status 2>&1");
local $rv = $out =~ /uptime/i ? 1 :
            $out =~ /denied|password/i ? -1 : 0;
$out =~ s/^.*\Q$config{'mysqladmin'}\E\s*:\s*//;
return wantarray ? ($rv, $out) : $rv;
}

# list_databases()
# Returns a list of all databases
sub list_databases
{
local @rv;
eval {
	# First try using SQL
	local $main::error_must_die = 1;
	local $t = &execute_sql_safe($master_db, "show databases");
	@rv = map { $_->[0] } @{$t->{'data'}};
	};
if (!@rv || $@) {
	# Fall back to mysqlshow command
	open(DBS, "\"$config{'mysqlshow'}\" $authstr |");
	local $t = &parse_mysql_table(DBS);
	close(DBS);
	ref($t) || &error("Failed to list databases : $t");
	@rv = map { $_->[0] } @{$t->{'data'}};
	}
return sort { lc($a) cmp lc($b) } @rv;
}

# list_tables(database, [empty-if-denied], [no-filter-views])
# Returns a list of tables in some database
sub list_tables
{
my ($db, $empty_denied, $include_views) = @_;
my @rv;
eval {
	# First try using SQL
	local $main::error_must_die = 1;
        local $t = &execute_sql_safe($db, "show tables");
        @rv = map { $_->[0] } @{$t->{'data'}};
	};
if ($@) {
	# Fall back to mysqlshow command
	local $tspec = $db =~ /_/ ? "%" : "";
	open(DBS, "\"$config{'mysqlshow'}\" $authstr ".
		  quotemeta($db)." $tspec 2>&1 |");
	local $t = &parse_mysql_table(DBS);
	close(DBS);
	if ($t =~ /access denied/i) {
		if ($empty_denied) {
			return ( );
			}
		else {
			&error($text{'edenied'});
			}
		}
	elsif (!ref($t)) {
		&error("<tt>".&html_escape($t)."</tt>");
		}
	@rv = map { $_->[0] } @{$t->{'data'}};
	}

# Filter out views
if (!$include_views) {
	if (&supports_views()) {
		my %views = map { $_, 1 } &list_views($db);
		@rv = grep { !$views{$_} } @rv;
		}
	}
return @rv;
}

# table_structure(database, table)
# Returns a list of hashes detailing the structure of a table
sub table_structure
{
local $s = &execute_sql_safe($_[0], "desc ".&quotestr($_[1]));
local (@rv, $r);
local (%tp, $i);
for($i=0; $i<@{$s->{'titles'}}; $i++) {
	$tp{lc($s->{'titles'}->[$i])} = $i;
	}
my $i = 0;
foreach $r (@{$s->{'data'}}) {
	push(@rv, { 'field' => $r->[$tp{'field'}],
		    'type' => $r->[$tp{'type'}],
		    'null' => $r->[$tp{'null'}],
		    'key' => $r->[$tp{'key'}],
		    'default' => $r->[$tp{'default'}],
		    'extra' => $r->[$tp{'extra'}],
		    'index' => $i++ });
	}
return @rv;
}

# table_field_sizes(db, table)
# Returns a hash mapping field names to sizes
sub table_field_sizes
{
local %rv;
foreach my $s (&table_structure(@_)) {
	if ($s->{'type'} =~ /^\S+\((\d+)(,\d+)?\)/) {
		$rv{lc($s->{'field'})} = $1;
		}
	}
return %rv;
}

# execute_sql(database, command, [param, ...])
# Executes some SQL and returns the results, after checking for the user's
# readonly status.
sub execute_sql
{
return { } if (&is_readonly_mode());
return &execute_sql_safe(@_);
}

# execute_sql_safe(database, command, [param, ...])
# Executes some SQL and returns the results as a hash ref with titles and
# data keys.
sub execute_sql_safe
{
local $sql = $_[1];
@params = @_[2..$#_];
if ($gconfig{'debug_what_sql'}) {
	# Write to Webmin debug log
	local $params;
	for(my $i=0; $i<@params; $i++) {
		$params .= " ".$i."=".$params[$i];
		}
	&webmin_debug_log('SQL', "db=$_[0] sql=$sql".$params);
	}
$sql = &escape_backslashes_in_quotes($sql);
if ($driver_handle && !$config{'nodbi'}) {
	# Use the DBI interface
	local $cstr = "database=$_[0]";
	$cstr .= ";host=$config{'host'}" if ($config{'host'});
	$cstr .= ";port=$config{'port'}" if ($config{'port'});
	$cstr .= ";mysql_socket=$config{'sock'}" if ($config{'sock'});
	$cstr .= ";mysql_read_default_file=$config{'my_cnf'}"
		if (-r $config{'my_cnf'});
	if ($config{'ssl'}) {
		$cstr .= ";mysql_ssl=1";
		if ($DBD::mysql::VERSION >= 4.043) {
			$cstr .= ";mysql_ssl_optional=1";
			}
		}
	local $dbh = $driver_handle->connect($cstr, $mysql_login, $mysql_pass,
					     { });
	$dbh || &error("DBI connect failed : ",$driver_handle->errstr);
	if ($sql_charset) {
		# Switch to correct character set
		local $sql = "set names '$sql_charset'";
		local $cmd = $dbh->prepare($sql);
		if (!$cmd) {
			&error(&text('esql', "<tt>".&html_escape($sql)."</tt>",
				     "<tt>".&html_escape($dbh->errstr)."</tt>"));
			}
		if (!$cmd->execute()) {
			&error(&text('esql', "<tt>".&html_escape($sql)."</tt>",
				     "<tt>".&html_escape($dbh->errstr)."</tt>"));
			}
		$cmd->finish();
		}
	local $cmd = $dbh->prepare($sql);
	if (!$cmd) {
		&error(&text('esql', "<tt>".&html_escape($_[1])."</tt>",
			     "<tt>".&html_escape($dbh->errstr)."</tt>"));
		}
	if (!$cmd->execute(@params)) {
		&error(&text('esql', "<tt>".&html_escape($_[1])."</tt>",
			     "<tt>".&html_escape($dbh->errstr)."</tt>"));
		}
	local (@data, @row);
	local @titles = @{$cmd->{'NAME'}};
	while(@row = $cmd->fetchrow()) {
		push(@data, [ @row ]);
		}
	$cmd->finish();
	$dbh->disconnect();
	return { 'titles' => \@titles,
		 'data' => \@data };
	}
else {
	# Use the mysql command program
	local $temp = &transname();
	if (@params) {
		# Sub in ? parameters
		$sql = &replace_sql_parameters($sql, @params);
		}
	open(TEMP, ">$temp");
	if ($sql_charset) {
		print TEMP "set names '$sql_charset';\n";
		}
	print TEMP $sql,"\n";
	close(TEMP);
	&set_authstr_env();
	open(DBS, "\"$config{'mysql'}\" $authstr -E -t ".quotemeta($_[0])." <$temp 2>&1 |");
	local $t = &parse_mysql_vertical(DBS);
	close(DBS);
	unlink($temp);
	if (!ref($t)) {
		$t =~ s/^ERROR[^:]*://;
		&error(&text('esql', "<tt>".&html_escape($_[1])."</tt>",
			    "<tt>".&html_escape($t)."</tt>"));
		}
	return $t;
	}
}

# replace_sql_parameters(sql, params)
# Returns a string with ? replaced by parameter text
sub replace_sql_parameters
{
my ($sql, @params) = @_;
my $pos = -1;
foreach my $p (@params) {
	$pos = index($sql, '?', $pos+1);
	&error("Incorrect number of parameters") if ($pos < 0);
	local $qp = $p;
	$qp =~ s/'/''/g;
	$qp = !defined($qp) ? 'NULL' : "'$qp'";
	$sql = substr($sql, 0, $pos).$qp.substr($sql, $pos+1);
	$pos += length($qp)-1;
	}
return $sql;
}

# execute_sql_logged(database, command, param, ...)
# Calls execute_sql, but logs the command first
sub execute_sql_logged
{
local ($db, $sql, @params) = @_;
if (@params) {
	eval {
		local $main::error_must_die = 1;
		$sql = &replace_sql_parameters($sql, @params);
		}
	}
&additional_log('sql', $db, $sql);
return &execute_sql(@_);
}

# parse_mysql_table(handle)
# Given a filehandle, parses a text table in the format mysql uses
sub parse_mysql_table
{
local $fh = $_[0];
local ($line, $i, @edge);
do {
	# skip to table top
	$line = <$fh>;
	return $line if ($line =~ /^(ERROR|\S*mysqlshow:)/);
	} while($line && $line !~ /^\+/);
for($i=0; $i<length($line); $i++) {
	push(@edge, $i) if (substr($line, $i, 1) eq '+');
	}
$line = <$fh>;		# skip first row of -'s
local @titles = &parse_mysql_line($line, \@edge);
$line = <$fh>;		# skip next row of -'s
local @data;
while(1) {
	$line = <$fh>;
	last if (!$line || $line !~ /^\|/);
	while($line !~ /\|\s+$/) {
		# Line has a return in it!
		$line .= <$fh>;
		}
	push(@data, [ &parse_mysql_line($line, \@edge) ]);
	}
return { 'titles' => \@titles,
	 'data' => \@data };
}

# parse_mysql_line(line, &edges)
sub parse_mysql_line
{
local @rv;
for($i=0; $i<@{$_[1]}-1; $i++) {
	local $w = substr($_[0], $_[1]->[$i]+1,
			  $_[1]->[$i+1] - $_[1]->[$i] - 2);
	$w =~ s/^\s//;
	$w =~ s/\s+$//;
	$w =~ s/\\/\\\\/g;
	$w =~ s/\n/\\n/g;
	push(@rv, $w);
	}
return @rv;
}

# parse_mysql_vertical(handle)
# Parses mysql output in the -E format
sub parse_mysql_vertical
{
local (@data, @titles, $row = -1, $col, %hascol);
local $fh = $_[0];
local $line = <$fh>;
if (!$line) {
	# No output at all - must be a non-select
	return { };
	}
return $line if ($line =~ /^ERROR/);
local $errtxt = &text('eparse', "<tt>mysql</tt>", "<tt>DBI</tt>",
		      "<tt>DBD::mysql</tt>");
while($line) {
	$line =~ s/\r|\n//g;
	if ($line =~ /^\*\*\*/) {
		# A row header
		$row++;
		$col = -1;
		$data[$row] = [ ];
		}
	elsif ($line =~ /^\s*([^:\s]+): (.*)/ && ($row == 0 || $hascol{$1})) {
		# A new column
		$col++;
		$titles[$col] = $1;
		$row >= 0 || return $errtxt;
		$data[$row]->[$col] = $2;
		$hascol{$1}++;
		}
	else {
		# Continuing the last column
		$row >= 0 || return $errtxt;
		$data[$row]->[$col] .= "\n".$line;
		}
	$line = <$fh>;
	}
return { 'titles' => \@titles,
	 'data' => \@data };
}

sub can_edit_db
{
if ($module_info{'usermin'}) {
	foreach $l (split(/\t/, $config{'access'})) {
		if ($l =~ /^(\S+):\s*(.*)$/ &&
		    ($1 eq $remote_user || $1 eq '*')) {
			local @dbs = split(/\s+/, $2);
			local $d;
			foreach $d (@dbs) {
				$d =~ s/\$REMOTE_USER/$remote_user/g;
				return 1 if ($d eq '*' || $_[0] =~ /^$d$/);
				}
			return 0;
			}
		}
	return 0;
	}
else {
	local $d;
	return 1 if ($access{'dbs'} eq '*');
	foreach $d (split(/\s+/, $access{'dbs'})) {
		return 1 if ($d && $d eq $_[0]);
		}
	return 0;
	}
}

# supports_backup_db(name)
# Returns 1 if some database can be backed up
sub supports_backup_db
{
return $_[0] ne "information_schema" &&
       $_[0] ne "performance_schema";
}

# list_accessible_databases()
# Returns a list of databases that the current user may access to. Returns
# an empty list if he has all of them.
sub list_accessible_databases
{
if ($module_info{'usermin'}) {
	# From Usermin list
	local @rv;
	foreach $l (split(/\t/, $config{'access'})) {
		if ($l =~ /^(\S+):\s*(.*)$/ &&
		    ($1 eq $remote_user || $1 eq '*')) {
			push(@rv, split(/\s+/, $2));
			}
		}
	return @rv;
	}
else {
	# From Webmin access control list
	return ( ) if ($access{'dbs'} eq '*');
	return split(/\s+/, $access{'dbs'});
	}
}

# split_table(&titles, &checkboxes, &links, &col1, &col2, ...)
# Outputs a table that is split into two parts
sub split_table
{
local $mid = int((@{$_[2]}+1) / 2);
local ($i, $j);
print "<table width=100%><tr>\n";
foreach $s ([0, $mid-1], [$mid, @{$_[2]}-1]) {
	print "<td width=50% valign=top>\n";

	# Header
	local @tds = $_[1] ? ( "width=5" ) : ( );
	if ($s->[0] <= $s->[1]) {
		local @hcols;
		foreach $t (@{$_[0]}) {
			push(@hcols, $t);
			}
		print &ui_columns_start(\@hcols, 100, 0, \@tds);
		}

	for($i=$s->[0]; $i<=$s->[1]; $i++) {
		local @cols;
		push(@cols, "<a href='$_[2]->[$i]'>$_[3]->[$i]</a>");
		for($j=4; $j<@_; $j++) {
			push(@cols, $_[$j]->[$i]);
			}
		if ($_[1]) {
			print &ui_checked_columns_row(\@cols, \@tds, "d", $_[1]->[$i]);
			}
		else {
			print &ui_columns_row(\@cols, \@tds);
			}
		}
	if ($s->[0] <= $s->[1]) {
		print &ui_columns_end();
		}
	print "</td>\n";
	}
print "</tr></table>\n";
}

# select_db(db)
# Returns HTML for selecting a database
sub select_db
{
my ($db) = @_;
my $rv;
my @dbs = &list_databases();
my @opts = map { [ &quote_mysql_database($_), $_ ] } @dbs;
local $d;
if ($access{'perms'} == 2 && $access{'dbs'} ne '*') {
	# Can only select his own databases
	@opts = grep { &can_edit_db($_->[1]) } @opts;
	$rv = &ui_select("dbs", $db, \@opts, 1, 0, $_[0] ? 1 : 0);
	}
else {
	# Can select any databases
	local $ind = &indexof($db, (map { $_->[0] } @opts)) >= 0;
	local $js1 = "onChange='form.db_def[1].checked = true'";
	local $js2 = "onClick='form.db_def[2].checked = true'";
	$rv = &ui_radio("db_def", $db eq '%' || $db eq '' ? 1 :
				  $ind ? 2 : 0,
			[ [ 1, $text{'host_any'} ],
			  [ 2, $text{'host_sel'}."&nbsp;".
			    &ui_select("dbs", $_[0], \@opts, 1, 0, 0, 0,$js1) ],
			  [ 0, $text{'host_otherdb'}."&nbsp;".
			       &ui_textbox("db", $db eq '%' || $db eq '' ||
						 $ind ? '' : $db, 30, 0,
					   undef, $js2) ] ]);
	}
return $rv;
}

sub quote_table
{
return &quotestr($_[0]);
}

# quotestr(string)
sub quotestr
{
local $rv = $_[0];
if (&supports_quoting()) {
	return "`$rv`";
	}
else {
	return $rv;
	}
}

# quote_mysql_database(name)
# Returns a MySQL database name with % and _ characters escaped
sub quote_mysql_database
{
local ($db) = @_;
$db =~ s/_/\\_/g;
$db =~ s/%/\\%/g;
return $db;
}

# unquote_mysql_database(name)
# Returns a MySQL database name with \% and \_ characters unescaped
sub unquote_mysql_database {
    my ($db) = @_;
    $db =~ s/\\%/%/g;
    $db =~ s/\\_/_/g;
    return $db;
}

# escapestr(string)
# Returns a string with quotes escaped, for use in SQL
sub escapestr
{
local $rv = $_[0];
$rv =~ s/'/''/g;
return $rv;
}

# escape_backslashes_in_quotes(string)
# Escapes backslashes, but only inside quoted strings
sub escape_backslashes_in_quotes
{
local ($str) = @_;
local $rv;
while($str =~ /^([^"]*)"([^"]*)"(.*)$/) {
	local ($before, $quoted, $after) = ($1, $2, $3);
	$quoted =~ s/\\/\\\\/g;
	$rv .= $before.'"'.$quoted.'"';
	$str = $after;
	}
$rv .= $str;
return $rv;
}

# supports_quoting()
# Returns 1 if running mysql version 3.23.6 or later
sub supports_quoting
{
return &compare_version_numbers($mysql_version, "3.23.6") >= 0;
}

# supports_mysqldump_events()
# Returns 1 if running mysqldump 5.1.8 or later, which supports (and needs)
# the events flag
sub supports_mysqldump_events
{
return &compare_version_numbers($mysql_version, "5.1.8") >= 0;
}

# supports_routines()
# Returns 1 if mysqldump supports routines
sub supports_routines
{
local $out = &backquote_command("$config{'mysqldump'} --help 2>&1 </dev/null");
return $out =~ /--routines/ ? 1 : 0;
}

# supports_views()
# Returns 1 if this MySQL install supports views
sub supports_views
{
return &compare_version_numbers($mysql_version, "5") >= 0;
}

# supports_variables()
# Returns 1 if running mysql version 4.0.3 or later
sub supports_variables
{
return &compare_version_numbers($mysql_version, "4.0.3") >= 0;
}

# supports_hosts()
# Returns 1 if the hosts table exists
sub supports_hosts
{
return &compare_version_numbers($mysql_version, "5.7.16") < 0;
}

# supports_env_pass([run-as-user], [password])
# Returns 1 if passing the password via an environment variable is supported
sub supports_env_pass
{
local ($user, $realpass) = @_;
$realpass ||= '';
if (&compare_version_numbers($mysql_version, "4.1") >= 0 && !$config{'nopwd'}) {
	# Theortically possible .. but don't do this if ~/.my.cnf contains
	# a [client] block with password= in it
	my @uinfo = $user ? getpwnam($user) : getpwuid($<);
	foreach my $cf ($config{'my_cnf'}, "$uinfo[7]/.my.cnf",
			"$ENV{'HOME'}/.my.cnf") {
		next if (!$cf || !-r $cf);
		local @cf = &parse_mysql_config($cf);
		local $client = &find("client", \@cf);
		next if (!$client);
		local $password = &find_value("password", $client->{'members'});
		return 0 if ($password ne '' && $password ne $realpass);
		}
	return 1;
	}
return 0;
}

# working_env_pass()
# Returns 1 if MYSQL_PWD can be used to pass the password to mysql
sub working_env_pass
{
return 1 if (!&supports_env_pass());	# Not even used
local $config{'nodbi'} = 1;
local $data;
local $main::error_must_die = 1;
eval { $data = &execute_sql_safe(undef, "select version()") };
return $@ || !$data ? 0 : 1;
}

# priv_fields(type)
# Returns the names and descriptions of fields for user/db/host privileges
sub priv_fields
{
my ($type) = @_;
if (!$priv_fields{$type}) {
	$priv_fields{$type} = [];
	foreach my $s (&table_structure("mysql", $type)) {
		if ($s->{'field'} =~ /^(.*)_priv/i) {
			push(@{$priv_fields{$type}},
			     [ $s->{'field'}, $text{'user_priv_'.lc($1)} ||
					      $s->{'field'} ]);
			}
		}
	}
return @{$priv_fields{$type}};
}

# ssl_fields()
# Returns the names of SSL fields that need to be set for new users
sub ssl_fields
{
my @desc = &table_structure($master_db, 'user');
my %fieldmap = map { $_->{'field'}, $_->{'index'} } @desc;
return grep { $fieldmap{$_} } ('ssl_type', 'ssl_cipher',
			       'x509_issuer', 'x509_subject');
}

# other_user_fields()
# Returns the names of other non-default new user fields
sub other_user_fields
{
my @desc = &table_structure($master_db, 'user');
my %fieldmap = map { $_->{'field'}, $_->{'index'} } @desc;
return grep { $fieldmap{$_} } ('authentication_string');
}

sub is_blob
{
return $_[0]->{'type'} =~ /(text|blob)$/i;
}

# get_mysql_version(&out)
# Returns a version number, undef if one cannot be found, or -1 for a .so
# problem. This is the version of the *local* mysql command, not necessarily
# the remote server. Maybe include the suffix -MariaDB.
sub get_mysql_version
{
local $out = &backquote_command("\"$config{'mysql'}\" -V 2>&1");
${$_[0]} = $out if ($_[0]);
if ($out =~ /lib\S+\.so/) {
	return -1;
	}
elsif ($out =~ /(distrib|Ver|from)\s+((3|4|5|6|7|8|9|10|11)\.[0-9\.]*(\-[a-z0-9]+)?)/i) {
	return $2;
	}
else {
	return undef;
	}
}

# get_remote_mysql_version()
# Returns the version of the MySQL server, or -1 if unknown
sub get_remote_mysql_version
{
local $main::error_must_die = 1;
local $data;
eval { $data = &execute_sql_safe(undef, "select version()"); };
return -1 if ($@);
return -1 if (!@{$data->{'data'}});
return $data->{'data'}->[0]->[0];
}

# get_remote_mysql_variant()
# Like get_remote_mysql_version, but returns a version number and variant
sub get_remote_mysql_variant
{
my $rv = &get_remote_mysql_version();
return ($rv) if ($rv <= 0);
my $variant = "mysql";
my ($ver, $variant_) = $rv =~ /^([0-9\.]+)\-(.*)/;
if ($ver && $variant_ && 
	($rv !~ /ubuntu/i || ($rv =~ /ubuntu/i && $rv =~ /mariadb/i && $ver > 10))) {
	$rv      = $ver;
	$variant = $variant_;
	if ($variant =~ /mariadb/i) {
		$variant = "mariadb";
		}
	else {
		$variant = "mysql";
		}
	}
return ($rv, $variant);
}

# save_mysql_version([number])
# Update the saved local MySQL version number
sub save_mysql_version
{
local ($ver) = @_;
$ver ||= &get_mysql_version();
if ($ver) {
	&open_tempfile(VERSION, ">$module_config_directory/version");
	&print_tempfile(VERSION, $ver,"\n");
	&close_tempfile(VERSION);
	}
}

# date_subs(filename)
# Does strftime-style date substitutions on a filename, if enabled
sub date_subs
{
local ($path) = @_;
local $rv;
if ($config{'date_subs'}) {
        eval "use POSIX";
	eval "use posix" if ($@);
        local @tm = localtime(time());
	&clear_time_locale();
        $rv = strftime($path, @tm);
	&reset_time_locale();
        }
else {
        $rv = $path;
        }
if ($config{'webmin_subs'}) {
	$rv = &substitute_template($rv, { });
	}
return $rv;
}

# execute_before(db, handle, escape, path, db-for-config)
# Executes the before-backup command for some DB, and sends output to the
# given file handle. Returns 1 if the command succeeds, or 0 on failure
sub execute_before
{
local $cmd = $config{'backup_before_'.$_[4]};
if ($cmd) {
	$ENV{'BACKUP_FILE'} = $_[3];
	local $h = $_[1];
	local $out;
	local $rv = &execute_command($cmd, undef, \$out, \$out);
	if ($h && $out) {
		print $h $_[2] ? "<pre>".&html_escape($out)."</pre>" : $out;
		}
	return !$rv;
	}
return 1;
}

# execute_after(db, handle, escape, path, db-for-config)
sub execute_after
{
local $cmd = $config{'backup_after_'.$_[4]};
if ($cmd) {
	$ENV{'BACKUP_FILE'} = $_[3];
	local $h = $_[1];
	local $out;
	local $rv = &execute_command($cmd, undef, \$out, \$out);
	if ($h && $out) {
		print $h $_[2] ? "<pre>".&html_escape($out)."</pre>" : $out;
		}
	return !$rv;
	}
return 1;
}

# show_table_form(count)
sub show_table_form
{
my $rv;
$rv = &ui_columns_start([ $text{'field_name'}, $text{'field_type'},
			  $text{'field_size'}, $text{'table_nkey'},
			  $text{'field_auto'}, $text{'field_null'},
			  $text{'field_unsigned'}, $text{'field_default'} ]);
for(my $i=0; $i<$_[0]; $i++) {
	my @cols;
	push(@cols, &ui_textbox("field_$i", undef, 20));
	push(@cols, &ui_select("type_$i", "", [ "", @type_list ]));
	push(@cols, &ui_textbox("size_$i", undef, 10));
	push(@cols, &ui_checkbox("key_$i", 1, $text{'yes'}, 0));
	push(@cols, &ui_checkbox("auto_$i", 1, $text{'yes'}, 0));
	push(@cols, &ui_checkbox("null_$i", 1, $text{'yes'}, 1));
	push(@cols, &ui_checkbox("unsigned_$i", 1, $text{'yes'}, 0));
	push(@cols, &ui_textbox("default_$i", undef, 20));
	$rv .= &ui_columns_row(\@cols);
	}
$rv .= &ui_columns_end();
return $rv;
}

# parse_table_form(&extrafields, tablename)
sub parse_table_form
{
local @fields = @{$_[0]};
local $i;
local (@auto, @pri);
for($i=0; defined($in{"field_$i"}); $i++) {
	next if (!$in{"field_$i"});
	$in{"field_$i"} =~ /^\S+$/ ||
		&error(&text('table_efield', $in{"field_$i"}));
	$in{"type_$i"} || &error(&text('table_etype', $in{"field_$i"}));
	if ($in{"type_$i"} eq 'enum' || $in{"type_$i"} eq 'set') {
		local @ev = split(/\s+/, $in{"size_$i"});
		@ev || &error(&text('table_eenum', $in{"type_$i"},
						   $in{"field_$i"}));
		$in{"size_$i"} = join(",", map { "'$_'" } @ev);
		}
	if ($in{"size_$i"}) {
		push(@fields, sprintf "%s %s(%s)",
		     &quotestr($in{"field_$i"}), $in{"type_$i"},$in{"size_$i"});
		}
	else {
		push(@fields, sprintf "%s %s",
			&quotestr($in{"field_$i"}), $in{"type_$i"});
		}
	if ($in{"unsigned_$i"}) {
		$fields[@fields-1] .= " unsigned";
		}
	if (!$in{"null_$i"}) {
		$fields[@fields-1] .= " not null";
		}
	if ($in{"key_$i"}) {
		$in{"null_$i"} && &error(&text('table_epnull',$in{"field_$i"}));
		push(@pri, $in{"field_$i"});
		}
	if ($in{"auto_$i"}) {
		push(@auto, $fields[@fields-1]);
		push(@autokey, $in{"key_$i"});
		}
	if ($in{"default_$i"}) {
		$fields[@fields-1] .= " default '".$in{"default_$i"}."'";
		}
	}
@auto < 2 || &error($text{'table_eauto'});
@fields || &error($text{'table_enone'});
local @sql;
local $sql = "create table ".&quotestr($_[1])." (".join(",", @fields).")";
$sql .= " engine $in{'type'}" if ($in{'type'});
push(@sql, $sql);
if (@pri) {
	# Setup primary fields too
	push(@sql, "alter table ".&quotestr($_[1])." add primary key (".
		    join(",", map { &quotestr($_) } @pri).")");
	}
if (@auto) {
	# Make field auto-increment
	push(@sql, "alter table ".&quotestr($_[1]).
		   " modify $auto[0] auto_increment ".
		   ($autokey[0] ? "" : "unique"));
	}
return @sql;
}

# execute_sql_file(database, file, [user, pass], [unix-user])
# Executes some file of SQL commands, and returns the exit status and output
sub execute_sql_file
{
if (&is_readonly_mode()) {
	return (0, undef);
	}
my ($db, $file, $user, $pass) = @_;
-r $file || return (1, "$file does not exist");
my $authstr = &make_authstr($user, $pass);
my $cs = $sql_charset ? "--default-character-set=".quotemeta($sql_charset)
			 : "";
my $temp = &transname();
$file = &fix_collation($file);
&open_tempfile(TEMP, ">$temp");
&print_tempfile(TEMP, "source ".$file.";\n");
&close_tempfile(TEMP);
&set_ownership_permissions(undef, undef, 0644, $temp);
&set_authstr_env();
my $cmd = "$config{'mysql'} $authstr -t ".quotemeta($db)." ".$cs.
	     " <".quotemeta($temp);
if ($_[4] && $_[4] ne 'root' && $< == 0) {
	# Restoring as a Unix user
	$cmd = &command_as_user($_[4], 0, $cmd);
	}
my $out = &backquote_logged("$cmd 2>&1");
my @rv;
if ($?) {
	# Total failure
	@rv = ($?, $out || "$cmd failed");
	}
elsif ($out =~ /(^|\n)(ERROR\s+\d+.*)/) {
	# Some command in the file failed
	@rv = (1, $2);
	}
else {
	# All OK
	@rv = (0, $out);
	}
&make_authstr();	# Put back old password environment variable
return @rv;
}

# start_mysql()
# Starts the MySQL database server, and returns undef on success or an
# error message on failure.
sub start_mysql
{
local $temp = &transname();
local $rv = &system_logged("($config{'start_cmd'}) >$temp 2>&1");
local $out = `cat $temp`; unlink($temp);
if ($rv || $out =~ /failed/i) {
	return "<pre>".&html_escape($out)."</pre>";
	}
return undef;
}

# stop_mysql()
# Halts the MySQL database server, and returns undef on success or an
# error message on failure.
sub stop_mysql
{
local $out;
if ($config{'stop_cmd'}) {
	$out = &backquote_logged("$config{'stop_cmd'} 2>&1");
	}
else {
	$out = &backquote_logged("$config{'mysqladmin'} $authstr shutdown 2>&1");
	}
if ($? || $out =~ /failed/i) {
	return "<pre>".&html_escape($out)."</pre>";
	}
return undef;
}

# split_enum(type)
# Returns a list of allowed values for an enum
sub split_enum
{
local ($type) = @_;
if ($type =~ /^(enum|set)\((.*)\)$/) {
	$type = $2;
	}
local $esize = $type;
local @ev;
while($esize =~ /^'([^']*)'(,?)(.*)$/) {
	push(@ev, $1);
	$esize = $3;
	}
return @ev;
}

# Returns 1 if the mysql server being managed is on this system
sub is_mysql_local
{
return $config{'host'} eq '' || $config{'host'} eq 'localhost' ||
       $config{'host'} eq &get_system_hostname() ||
       &to_ipaddress($config{'host'}) eq &to_ipaddress(&get_system_hostname());
}

# get_mysql_config()
# Returns the parsed my.cnf file
sub get_mysql_config
{
if (!scalar(@mysql_config_cache)) {
	if (!-r $config{'my_cnf'}) {
		return [];
		}
	@mysql_config_cache = &parse_mysql_config($config{'my_cnf'});
	}
return \@mysql_config_cache;
}

# parse_mysql_config(file)
# Reads one MySQL config file
sub parse_mysql_config
{
local ($file) = @_;
local @rv;
local $sect;
local $lnum = 0;
local $lref = &read_file_lines($file, 1);
local $_;
foreach (@$lref) {
	s/\r|\n//g;
	s/\s+$//;
	if (/^\s*(#|;)/) {
		$lnum++;
		next;
		}
	elsif (/^\s*\[(\S+)\]$/) {
		# Start of a section
		$sect = { 'name' => $1,
			  'members' => [ ],
			  'file' => $file,
			  'line' => $lnum,
			  'eline' => $lnum };
		push(@rv, $sect);
		}
	elsif (/^\s*(\S+)\s*=\s*(.*)$/ && $sect) {
		# Variable in a section
		push(@{$sect->{'members'}},
		     { 'name' => $1,
		       'value' => $2,
		       'file' => $file,
		       'line' => $lnum });
		$sect->{'eline'} = $lnum;
		}
	elsif (/^\s*(\S+)$/ && $sect) {
		# Single directive in a section
		push(@{$sect->{'members'}},
		     { 'name' => $1,
		       'file' => $file,
		       'line' => $lnum });
		$sect->{'eline'} = $lnum;
		}
	elsif (/^\s*\!include\s+(\S+)/) {
		# Including sections from a file
		foreach my $file (glob($1)) {
			push(@rv, &parse_mysql_config($file));
			}
		}
	elsif (/^\s*\!includedir\s+(\S+)/) {
		# Including sections from files in a directory
		my $dir = $1;
		$dir =~ s/\/$//;
		opendir(DIR, $dir);
		my @files = map { $dir."/".$_ } readdir(DIR);
		closedir(DIR);
		foreach my $file (@files) {
			push(@rv, &parse_mysql_config($file));
			}
		}
	$lnum++;
	}
return @rv;
}

# find(name, &conf)
sub find
{
local ($name, $conf) = @_;
local @rv = grep { lc($_->{'name'}) eq lc($name) } @$conf;
return wantarray ? @rv : $rv[0];
}

# find_value(name, &conf)
sub find_value
{
local ($name, $conf) = @_;
local @rv = map { $_->{'value'} } &find($name, $conf);
return wantarray ? @rv : $rv[0];
}

# save_directive(&conf, &section, name, &values)
# Updates one or multiple lines in a my.cnf section
sub save_directive
{
local ($conf, $sect, $name, $values) = @_;
local @old = &find($name, $sect->{'members'});
local $file = @old ? $old[0]->{'file'} :
	      $sect ? $sect->{'file'} : $config{'my_cnf'};
local $lref = &read_file_lines($file);

for(my $i=0; $i<@old || $i<@$values; $i++) {
	local $old = $i < @old ? $old[$i] : undef;
	local $line = $i >= @$values || $values->[$i] eq "" ? $name :
			"$name = $values->[$i]";
	if ($old && defined($values->[$i])) {
		# Updating
		$lref->[$old->{'line'}] = $line;
		$old->{'value'} = $values->[$i];
		}
	elsif (!$old && defined($values->[$i])) {
		# Adding
		splice(@$lref, $sect->{'eline'}+1, 0, $line);
		&renumber($conf, $sect->{'eline'}+1, 1, $file);
		push(@{$sect->{'members'}},
			{ 'name' => $name,
			  'value' => $values->[$i],
			  'line' => $sect->{'eline'}+1 });
		}
	elsif ($old && !defined($values->[$i])) {
		# Deleting
		splice(@$lref, $old->{'line'}, 1);
		&renumber($conf, $old->{'line'}, -1, $file);
		@{$sect->{'members'}} = grep { $_ ne $old }
					     @{$sect->{'members'}};
		}
	}
}

sub renumber
{
local ($conf, $line, $offset, $file) = @_;
foreach my $sect (@$conf) {
	next if ($sect->{'file'} ne $file);
	$sect->{'line'} += $offset if ($sect->{'line'} >= $line);
	$sect->{'eline'} += $offset if ($sect->{'eline'} >= $line);
	foreach my $m (@{$sect->{'members'}}) {
		$m->{'line'} += $offset if ($m->{'line'} >= $line);
		}
	}
}

# parse_set_variables(value, ...)
# Returns a hash of variable mappings
sub parse_set_variables
{
local %vars;
foreach my $v (@_) {
	if ($v =~ /^(\S+)=(\S+)$/) {
		$vars{$1} = $2;
		}
	}
return %vars;
}

sub mysql_size_input
{
local ($name, $value) = @_;
local $units;
if ($value =~ /^(\d+)([a-z])$/i) {
	$value = $1;
	$units = $2;
	}
$units = "" if ($units eq "b");
return &ui_textbox($name, $value, 8)."\n".
       &ui_select($name."_units", $units,
		  [ [ "", "bytes" ], [ "K", "kB" ],
		    [ "M", "MB" ], [ "G", "GB" ] ]);
}

# get_table_index_stats(db)
# Retrieves index stats for all tables in the given database
sub get_table_index_stats
{
my ($db) = @_;
my @tables = &list_tables($db);
my $sql_query = "
    SELECT 
        TABLE_SCHEMA,
        TABLE_NAME,
        INDEX_NAME,
        NON_UNIQUE,
        SEQ_IN_INDEX,
        COLUMN_NAME,
        COLLATION,
        CARDINALITY,
        SUB_PART,
        PACKED,
        NULLABLE,
        INDEX_TYPE,
        COMMENT,
        INDEX_COMMENT
    FROM 
        INFORMATION_SCHEMA.STATISTICS
    WHERE 
        TABLE_SCHEMA = ?
	AND
	TABLE_NAME IN (" . join(", ", ("?") x @tables) . ")
";
my $rs = &execute_sql_safe($db, $sql_query, $db, @tables);
return $rs;
}

# get_all_tables_size(db)
# Retrieves the size of all tables in the given database
sub get_all_tables_size
{
my ($db) = @_;
my @tables = list_tables($db);
my $sql_query = "
    SELECT
        TABLE_SCHEMA,
        TABLE_NAME,
        ENGINE,
        DATA_LENGTH + INDEX_LENGTH AS total_size_bytes
    FROM information_schema.TABLES
    WHERE TABLE_SCHEMA = ?
      AND TABLE_NAME IN (" . join(", ", ("?") x @tables) . ")
";
my $rs = &execute_sql_safe($db, $sql_query, $db, @tables);
return $rs;
}

# list_indexes(db)
# Returns the names of all indexes in some database
sub list_indexes
{
local ($db) = @_;
local (@rv, $r);
foreach my $table (&list_tables($db)) {
	local $s = &execute_sql_safe($db, "show index from ".&quotestr($table));
	local (%tp, $i);
	for($i=0; $i<@{$s->{'titles'}}; $i++) {
		$tp{lc($s->{'titles'}->[$i])} = $i;
		}
	foreach $r (@{$s->{'data'}}) {
		if ($r->[$tp{'key_name'}] ne 'PRIMARY') {
			push(@rv, $r->[$tp{'key_name'}]);
			}
		}
	}
return &unique(@rv);
}

# index_structure(db, indexname)
# Returns information on an index
sub index_structure
{
local ($db, $index) = @_;
local (@rv, $r);
local $info;
foreach my $table (&list_tables($db)) {
	local $s = &execute_sql_safe($db, "show index from ".&quotestr($table));
	local (%tp, $i);
	for($i=0; $i<@{$s->{'titles'}}; $i++) {
		$tp{lc($s->{'titles'}->[$i])} = $i;
		}
	foreach $r (@{$s->{'data'}}) {
		if ($r->[$tp{'key_name'}] eq $index) {
			# Found some info
			$info->{'table'} = $r->[$tp{'table'}];
			$info->{'name'} = $index;
			$info->{'type'} = lc($r->[$tp{'index_type'}]) ||
					  lc($r->[$tp{'comment'}]);
			push(@{$info->{'cols'}}, $r->[$tp{'column_name'}]);
			}
		}
	}
return $info;
}

# parse_index_structure(&db_stats, db, indexname)
# Returns information on an index based on the database stats hash
sub parse_index_structure
{
my ($db_stats, $db, $index) = @_;
my ($r, $info);
foreach my $table (&list_tables($db)) {
	my $s = { %$db_stats };
	$s->{'data'} = [grep { $_->[1] eq $table } @{$s->{'data'}}];
	my (%tp, $i);
	for($i=0; $i<@{$s->{'titles'}}; $i++) {
		$tp{lc($s->{'titles'}->[$i])} = $i;
		}
	foreach $r (@{$s->{'data'}}) {
		if ($r->[$tp{'index_name'}] eq $index) {
			# Found some info
			$info->{'table'} = $r->[$tp{'table_name'}];
			$info->{'name'} = $index;
			$info->{'type'} = lc($r->[$tp{'index_type'}]) ||
					  lc($r->[$tp{'comment'}]);
			push(@{$info->{'cols'}}, $r->[$tp{'column_name'}]);
			}
		}
	}
return $info;
}

# list_views(db)
# Returns the names of all views in some database
sub list_views
{
local ($db) = @_;
local @rv;
local $d = &execute_sql($db, "select table_schema,table_name from information_schema.views where table_schema = ?", $db);
foreach $r (@{$d->{'data'}}) {
	push(@rv, $r->[1]);
	}
return @rv;
}

# view_structure(db, viewname)
# Returns information about a view
sub view_structure
{
local ($db, $view) = @_;
local $info = { 'name' => $view };
local $d = &execute_sql($db, "show create view $view");
local $c = $d->{'data'}->[0]->[1];
if ($c =~ /algorithm\s*=\s*(\S+)/i) {
	$info->{'algorithm'} = lc($1);
	}
if ($c =~ /definer\s*=\s*`(\S+)`\@`(\S+)`/i) {
	$info->{'definer'} = "$1\@$2";
	}
elsif ($c =~ /definer\s*=\s*(\S+)/i) {
	$info->{'definer'} = $1;
	}
if ($c =~ /sql\s+security\s+(\S+)/i) {
	$info->{'security'} = lc($1);
	}
if ($c =~ s/\s+with\s+(cascaded|local)\s+check\s+option//i) {
	$info->{'check'} = lc($1);
	}
if ($c =~ /view\s+(`\S+`|\S+)\s+as\s+(.*)/i) {
	$info->{'query'} = $2;
	}
return $info;
}

# list_character_sets([db])
# Returns a list of supported character sets. Each row is an array ref of
# a code and name
sub list_character_sets
{
local @rv;
local $db = $_[0] || $master_db;
if (&compare_version_numbers(&get_remote_mysql_version(), "4.1") < 0) {
	local $d = &execute_sql($db, "show variables like 'character_sets'");
	@rv = map { [ $_, $_ ] } split(/\s+/, $d->{'data'}->[0]->[1]);
	}
else {
	local $d = &execute_sql($db, "show character set");
	@rv = map { [ $_->[0], "$_->[1] ($_->[0])" ] } @{$d->{'data'}};
	}
return sort { lc($a->[1]) cmp lc($b->[1]) } @rv;
}

# get_character_set(db)
# Returns the character set for a database
sub get_character_set
{
my ($db) = @_;
my $d;
eval {
	local $main::error_must_die = 1;
	$d = &execute_sql($db, 'select @@character_set_database');
	};
return undef if ($@);
return undef if (!@{$d->{'data'}});
return $d->{'data'}->[0]->[0];
}

# list_collation_orders([db])
# Returns a list of supported collation orders. Each row is an array ref of
# a code and character set it can work with.
sub list_collation_orders
{
local @rv;
local $db = $_[0] || $master_db;
if (&compare_version_numbers(&get_remote_mysql_version(), "5") >= 0) {
	local $d = &execute_sql($db, "show collation");
	@rv = map { [ $_->[0], $_->[1] ] } @{$d->{'data'}};
	}
return sort { lc($a->[0]) cmp lc($b->[0]) } @rv;
}

# get_collation_order(db)
# Returns the collation order for a database
sub get_collation_order
{
my ($db) = @_;
my $d;
eval {
	local $main::error_must_die = 1;
	$d = &execute_sql($db, 'select @@collation_database');
	};
return undef if ($@);
return undef if (!@{$d->{'data'}});
return $d->{'data'}->[0]->[0];
}

# fix_collation(file)
# Fixes unsupported collations on restore, by replacing
# unsuported with the closest supported variant
sub fix_collation
{
my ($file) = @_;
my ($version, $variant) = &get_remote_mysql_variant();
if ($variant eq 'mariadb') {
	my $tfile = &transname();
	open(IN, '<' . $file) or die $!;
	open(OUT, '>' . $tfile) or die $!;
	while(<IN>) {
		s/COLLATE(\s|=)utf8mb4_0900_ai_ci/COLLATE$1utf8mb4_unicode_520_ci/g;
		print OUT;
		}
	close(OUT);
	close(IN);
	&copy_permissions_source_dest($file, $tfile);
	return $tfile;
	}
return $file;
}

# list_system_variables()
# Returns a list of all system variables, and their default values
sub list_system_variables
{
local $mysqld = $config{'mysqld'};
if (!$mysqld) {
	# Mysqld path not in config .. guess from mysql path
	$mysqld = $config{'mysql'};
	$mysqld =~ s/mysql$/mysqld/g;
	$mysqld =~ s/bin/sbin/g;
	if (!-x $mysqld) {
		$mysqld = $config{'mysql'};
		$mysqld =~ s/mysql$/mysqld/g;
		$mysqld =~ s/bin/libexec/g;
		if (!-x $mysqld) {
			# Look in Webmin path
			&error($mysqld);
			$mysqld = &has_command("mysqld");
			}
		}
	}
return ( ) if (!$mysqld);

# Read supported variables
local @rv;
&open_execute_command(MYSQLD, "$mysqld --verbose --help", 1, 1);
while(<MYSQLD>) {
	s/\r|\n//g;
	if (/^(\S+)\s+current\s+value:\s+(\S*)/) {
		push(@rv, [ $1, $2 ]);
		}
	elsif (/^\-\-\-\-/) {
		$started = 1;
		}
	elsif ($started && /^(\S+)\s+(.*)/) {
		push(@rv, [ $1, $2 eq "(No default value)" ? undef : $2 ]);
		}
	}
close(MYSQL);
return @rv;
}

# list_compatible_formats()
# Returns a list of two-element arrays, containing compatibility format
# codes and descriptions
sub list_compatible_formats
{
return map { [ $_, $text{'compat_'.$_} ] }
	   ( "ansi", "mysql323", "mysql40", "postgresql", "oracle", "mssql",
	     "db2", "maxdb" );
}

# list_compatible_options()
# Returns a list of two-element arrays, containing compatibility options
sub list_compatible_options
{
return map { [ $_, $text{'compat_'.$_} ] }
	   ( "no_key_options", "no_table_options", "no_field_options" );
}

# compression_format(file)
# Returns 0 if uncompressed, 1 for gzip, 2 for compress, 3 for bzip2 or
# 4 for zip
sub compression_format
{
open(BACKUP, "<".$_[0]);
local $two;
read(BACKUP, $two, 2);
close(BACKUP);
return $two eq "\037\213" ? 1 :
       $two eq "\037\235" ? 2 :
       $two eq "PK" ? 4 :
       $two eq "BZ" ? 3 : 0;
}

# backup_database(db, dest-file, compress-mode, drop-flag, where-clause,
#                 charset, &compatible, &only-tables, run-as-user,
#                 single-transaction-flag, quick-flag, force-flag, parameters)
# Backs up a database to the given file, optionally with compression. Returns
# undef on success, or an error message on failure.
sub backup_database
{
my ($db, $file, $compress, $drop, $where, $charset, $compatible,
       $tables, $user, $single, $quick, $force, $parameters) = @_;
my $writer;
if ($compress == 0) {
	$writer = "cat >".quotemeta($file);
	}
elsif ($compress == 1) {
	$writer = "gzip -c >".quotemeta($file);
	}
elsif ($compress == 2) {
	$writer = "bzip2 -c >".quotemeta($file);
	}
my $dropsql = $drop ? "--add-drop-table" : "";
my $singlesql = $single ? "--single-transaction" : "";
my $forcesql = $force ? "--force" : "";
my $quicksql = $quick ? "--quick" : "";
my $parameterssql = $parameters ?
	join(" ", map { quotemeta($_) } split(/\s+/, $parameters)) : "";
my $wheresql = $where ? "--where=".quotemeta($in{'where'}) : "";
my $charsetsql = $charset ?
	"--default-character-set=".quotemeta($charset) : "";
my $compatiblesql = @$compatible ?
	"--compatible=".join(",", @$compatible) : "";
my $quotingsql = &supports_quoting() ? "--quote-names" : "";
my $routinessql = &supports_routines() ? "--routines" : "";
my $tablessql = join(" ", map { quotemeta($_) } @$tables);
my $eventssql = &supports_mysqldump_events() ? "--events" : "";
my $gtidsql = "";
eval {
	local $main::error_must_die = 1;
	my $d = &execute_sql($master_db, "show variables like 'gtid_mode'");
	if (@{$d->{'data'}} && uc($d->{'data'}->[0]->[1]) eq 'ON' &&
	    &compare_version_numbers($mysql_version, "5.6") >= 0) {
		# Add flag to support GTIDs
		$gtidsql = "--set-gtid-purged=OFF";
		}
	};
if ($user && $user ne "root") {
	# Actual writing of output is done as another user
	$writer = &command_as_user($user, 0, $writer);
	}
&set_authstr_env();
my $cmd = "$config{'mysqldump'} $authstr $dropsql $singlesql $forcesql $quicksql $parameterssql $wheresql $charsetsql $compatiblesql $quotingsql $routinessql ".quotemeta($db)." $tablessql $eventssql $gtidsql | $writer";
if (&shell_is_bash()) {
	$cmd = "set -o pipefail ; $cmd";
	}
my $out = &backquote_logged("($cmd) 2>&1");
if ($? || !-s $file || $out =~ /Aborted\s+connection|max_allowed_packet/i) {
	return $out;
	}
return undef;
}

# delete_database_backup_job(db)
# If there is a backup scheduled for some database, remove it
sub delete_database_backup_job
{
my ($db) = @_;
&foreign_require("cron");
my @jobs = &cron::list_cron_jobs();
my $cmd = "$cron_cmd $db";
my ($job) = grep { $_->{'command'} eq $cmd } @jobs;
if ($job) {
	&lock_file(&cron::cron_file($job));
	&cron::delete_cron_job($job);
	&unlock_file(&cron::cron_file($job));
	}
}

# get_all_mysqld_files()
# Returns all config files used by MySQLd
sub get_all_mysqld_files
{
my $conf = &get_mysql_config();
return &unique(map { $_->{'file'} } @$conf);
}

# get_change_pass_sql(unescaped_plaintext_password, user, host)
# Get the right query for changing user password
sub get_change_pass_sql
{
my ($unescaped_plainpass, $user, $host) = @_;
my $plugin = &get_mysql_plugin();
$plugin = $plugin ? "with $plugin" : "";
my $escaped_pass = &escapestr($unescaped_plainpass);
my $sql;
my ($ver, $variant) = &get_remote_mysql_variant();
my $mysql_mariadb_with_auth_string = 
   $variant eq "mariadb" && &compare_version_numbers($ver, "10.2") >= 0 ||
   $variant eq "mysql" && &compare_version_numbers($ver, "5.7.6") >= 0;
if ($mysql_mariadb_with_auth_string && $unescaped_plainpass) {
	$sql = "alter user '$user'\@'$host' identified $plugin by '$escaped_pass'";
	}
else {
	$sql = "set password for '".$user."'\@'".$host."' = ".
	       "$password_func('$escaped_pass')";
	}
return $sql;
}

# get_mysql_plugin()
# Returns the name of the default plugin used by MySQL/MariaDB
sub get_mysql_plugin
{
if ($config{'auth_plugin'}) {
	return $config{'auth_plugin'};
	}
my $rv = &execute_sql($master_db, 
    "show variables LIKE '%default_authentication_plugin%'");
return undef if (!ref($rv) || !@{$rv->{'data'}});
return $rv->{'data'}->[0]->[1];
}

# perms_column_to_privilege_map()
# Returns a privilege name based on given column for MySQL 8+ and MariaDB 10.4
sub perms_column_to_privilege_map
{
my %priv = (
	'Alter_priv', 'alter',
	'Alter_routine_priv', 'alter routine',
	'Create_priv', 'create',
	'Create_routine_priv', 'create routine',
	'Create_tablespace_priv', 'create tablespace',
	'Create_tmp_table_priv', 'create temporary tables',
	'Create_user_priv', 'create user',
	'Create_view_priv', 'create view',
	'Delete_priv', 'delete',
	'Drop_priv', 'drop',
	'Event_priv', 'event',
	'Execute_priv', 'execute',
	'File_priv', 'file',
	'Grant_priv', 'grant option',
	'Index_priv', 'index',
	'Insert_priv', 'insert',
	'Lock_tables_priv', 'lock tables',
	'Process_priv', 'process',
	'References_priv', 'references',
	'Reload_priv', 'reload',
	'Repl_client_priv', 'replication client',
	'Repl_slave_priv', 'replication slave',
	'Select_priv', 'select',
	'Show_db_priv', 'show databases',
	'Show_view_priv', 'show view',
	'Shutdown_priv', 'shutdown',
	'Super_priv', 'super',
	'Trigger_priv', 'trigger',
	'Update_priv', 'update',
	'Delete_history_priv', 'delete history',
	);
return \%priv;
}

# update_privileges(\%sconfig)
# Update user privileges
sub update_privileges
{
my ($sc) = @_;

my $user = $sc->{'user'};
my $host = $sc->{'host'};
my $perms = $sc->{'perms'};
my $pfields = $sc->{'pfields'};

my ($ver, $variant) = &get_remote_mysql_variant();

if ($variant eq "mariadb" && &compare_version_numbers($ver, "10.4") >= 0) {
	# Assign permissions
	my $col_to_priv_map = &perms_column_to_privilege_map();
	foreach my $grant (keys %$perms) {
		my $grant_priv = $perms->{$grant};
		&execute_sql_logged($mysql::master_db, "grant $grant_priv on *.* to '$user'\@'$host'");
		delete $col_to_priv_map->{$grant};
		}
	foreach my $revoke_priv (values %{ $col_to_priv_map }) {
		&execute_sql_logged($mysql::master_db, "revoke $revoke_priv on *.* from '$user'\@'$host'");
		}
	}
else {
	$sql = "update user set ".
	       join(", ",map { "$_ = ?" } @{ $pfields }).
	       " where host = ? and user = ?";
	&execute_sql_logged($master_db, $sql,
		(map { $perms{$_} ? 'Y' : 'N' } @{ $pfields }),
		$host, $user);
	}
&execute_sql_logged($master_db, 'flush privileges');
}


# rename_user(\%sconfig)
# Rename SQL user
sub rename_user
{
my ($sc) = @_;
my $user = $sc->{'user'};
my $olduser = $sc->{'olduser'};
my $host = $sc->{'host'};
my $oldhost = $sc->{'oldhost'};

my ($ver, $variant) = &get_remote_mysql_variant();
my $sql;
if ($variant eq "mariadb" && &compare_version_numbers($ver, "10.4") >= 0) {
	&execute_sql_logged($master_db, "rename user '$olduser'\@'$oldhost' to '$user'\@'$host'");
	}
else {
	&execute_sql_logged($master_db,
		"update user set host = ?, user = ? where host = ? and user = ?",
		$host, $user,
		$oldhost, $olduser);
	}
&update_config_credentials({
		'user', $user,
		'olduser', $olduser,
		});
&execute_sql_logged($master_db, 'flush privileges');
}

# create_user(\%sconfig)
# Create new SQL user
sub create_user
{
my ($sc) = @_;
my $user = $sc->{'user'};
my $pass = $sc->{'pass'};
my $host = $sc->{'host'};
my $perms = $sc->{'perms'};
my $pfields = $sc->{'pfields'};
my $ssl_field_names = $sc->{'ssl_field_names'};
my $ssl_field_values = $sc->{'ssl_field_values'};
my $other_field_names = $sc->{'other_field_names'};
my $other_field_values = $sc->{'other_field_values'};

my ($ver, $variant) = &get_remote_mysql_variant();
my $plugin = $sc->{'plugin'} || &get_mysql_plugin();
$plugin = $plugin ? "with $plugin" : "";

if ($variant eq "mariadb" && &compare_version_numbers($ver, "10.4") >= 0) {
	my $sql = "create user '$user'\@'$host' identified $plugin by ".
		"'".&escapestr($pass)."'";
	&execute_sql_logged($master_db, $sql);
	&execute_sql_logged($master_db, 'flush privileges');

	# Update existing user privileges
	&update_privileges({(
		'user', $user,
		'host', $host,
		'perms', $perms,
		'pfields', $pfields
		)});
	}
else {
	my $sql = "insert into user (host, user, ".
	       join(", ", @{ $pfields }, @{ $ssl_field_names },
			  @{ $other_field_names }).
	       ") values (?, ?, ".
	       join(", ", map { "?" } (@{ $pfields }, @{ $ssl_field_names },
				       @{ $other_field_names })).")";
	&execute_sql_logged($master_db, $sql,
		$host, $user,
		(map { $perms->{$_} ? 'Y' : 'N' } @{ $pfields }),
		@{ $ssl_field_values }, @{ $other_field_values });
	&execute_sql_logged($master_db, 'flush privileges');

	if ($variant eq "mysql" && &compare_version_numbers($ver, "5.7.6") >= 0) {
		&execute_sql_logged($master_db,
		    "alter user '$user'\@'$host' identified $plugin by ".
		        "'".&escapestr($pass)."'");
		&execute_sql_logged($master_db, 'flush privileges');
		}
	}
}

# change_user_password(plainpass, user, host, plugin)
# Change user password
sub change_user_password
{
my ($plainpass, $user, $host, $plugin) = @_;

my ($ver, $variant) = &get_remote_mysql_variant();
$plugin ||= &get_mysql_plugin();
$plugin = $plugin ? "with $plugin" : "";
my $lock_supported = $variant eq "mysql" && &compare_version_numbers($ver, "8.0.19");
my $mysql_mariadb_with_auth_string = 
	$variant eq "mariadb" && &compare_version_numbers($ver, "10.4") >= 0 ||
	$variant eq "mysql" && &compare_version_numbers($ver, "5.7.6") >= 0;

my $sql;
my $pass = &escapestr($plainpass);
$host ||= '%';
my $lock = !defined($plainpass);
if ($lock) {
	$pass = sprintf("%x", rand 16) for 1..30;
	}
if ($mysql_mariadb_with_auth_string) {
	my $sp = "identified $plugin by '".$pass."'";
	if ($lock_supported) {
		$sp = $lock ? "account lock" : "$sp account unlock";
		}
	$sql = "alter user '$user'\@'$host' $sp";
	&execute_sql_logged($master_db, $sql);
	}
else {
	$sql = &get_change_pass_sql($plainpass, $user, $host);
	&execute_sql_logged($master_db, $sql);
	}

# Update module password when needed
&update_config_credentials({
		'user', $user,
		'olduser', $user,
		'pass', $plainpass,
		});
&execute_sql_logged($master_db, 'flush privileges');
}

# Update Webmin module login and pass
sub update_config_credentials
{
return if($access{'user'});
my ($c) = @_;
my $conf_user = $config{'login'} || "root";
return if($c->{'olduser'} ne $conf_user);
return if(!$c->{'user'});

$config{'login'} = $c->{'user'};
$mysql_login = $c->{'user'};
if (defined($c->{'pass'})) {
	$config{'pass'} = $c->{'pass'};
	$mysql_pass = $c->{'pass'};
	}
&lock_file($module_config_file);
&save_module_config();
&unlock_file($module_config_file);
&stop_mysql();
&start_mysql();
}

# force_set_mysql_admin_pass(user, pass)
# Forcibly change MySQL admin password, if lost or forgotten
sub force_set_mysql_admin_pass
{
my ($user, $pass) = @_;
&error_setup($text{'mysqlpass_err'});
&foreign_require("proc");

# Find the mysqld_safe command
my $safe = &has_command("mysqld_safe");
if (!$safe) {
	&error(&text('mysqlpass_esafecmd', "<tt>mysqld_safe</tt>"));
	}

# Shut down server if running
if (&is_mysql_running()) {
	my $err = &stop_mysql();
	if ($err) {
		&error(&text('mysqlpass_esafecmdeshutdown', $err));
		}
	}

# Start up with skip-grants flag
my $cmd = $safe." --skip-grant-tables";

# Running with `mysqld_safe` - when called, command doesn't create "mysqld" directory under
# "/var/run" eventually resulting in DBI connect failed error on all MySQL versions
my $ver = &get_mysql_version();
if ($ver !~ /mariadb/i) {
	my $mysockdir = '/var/run/mysqld';
	my $myusergrp = 'mysql';
	my $myconf = &get_mysql_config();
	if ($myconf) {
		my ($mysqld) = grep { $_->{'name'} eq 'mysqld' } @$myconf;
		if ($mysqld) {
			my $members = $mysqld->{'members'};

			# Look for user
			my $myusergrp_ = &find_value("user", $members);
			if ($myusergrp_) {
				$myusergrp = $myusergrp_;
				}

			# Look for socket
			my $mysockdir_ = &find_value("socket", $members);
			if ($mysockdir_) {
				$mysockdir = $mysockdir_;
				$mysockdir =~ s/^(.+)\/([^\/]+)$/$1/;
				}
			}
		}
	$cmd = "mkdir -p $mysockdir && chown $myusergrp:$myusergrp $mysockdir && $cmd";
	}
my ($pty, $pid) = &proc::pty_process_exec($cmd, 0, 0);
sleep(5);
if (!$pid || !kill(0, $pid)) {
	my $err = <$pty>;
	&error(&text('mysqlpass_esafe', $err));
	}

# Update password by running command directly
my $cmd = $config{'mysql'} || 'mysql';
my $sql = &get_change_pass_sql($pass, $user, 'localhost');
my $out = &backquote_command("$cmd -D $master_db -e ".
		quotemeta("flush privileges; $sql")." 2>&1 </dev/null");
if ($?) {
		$out =~ s/\n/ /gm;
		&error(&text('mysqlpass_echange', "$out"));
		}
else {

	# Update root password now for other
	# hosts, using regular database connection
	my $d = &execute_sql_safe($master_db,
		"select host from user where user = ?", $user);
	@hosts = map { $_->[0] ne 'localhost' } @{$d->{'data'}};
	foreach my $host (@hosts) {
		$sql = get_change_pass_sql($pass, $user, $host);
		eval {
			local $main::error_must_die = 1;
			&execute_sql_logged($master_db, 'flush privileges');
			&execute_sql_logged($master_db, $sql);
			&execute_sql_logged($master_db, 'flush privileges');
			sleep 1;
			};
		}
	}

# Shut down again, with the mysqladmin command
my $mysql_shutdown = $config{'mysqladmin'} || 'mysqladmin';
my $out = &backquote_logged("$mysql_shutdown shutdown 2>&1 </dev/null");
if ($?) {
	$out =~ s/\n/ /gm;
	&error(&text('mysqlpass_eshutdown', $out));
	}

# Finally, re-start in normal mode
my $err = &start_mysql();
if ($err) {
	&error(&text('mysqlpass_estartup', $err));
	}
&error_setup($text{'login_err'});
}

# create_module_info_overrides()
# Update the overrides file used for module.info to reflect MariaDB
sub create_module_info_overrides
{
my %info = &get_module_info(&get_module_name(), 0, 1);
my %overs;
if ($mysql_version =~ /mariadb/i) {
	$overs{'desc'} = $info{'original_desc'} || $info{'desc'};
	$overs{'desc'} =~ s/MySQL/MariaDB/g;
	}
&write_file("$module_config_directory/module.info.override", \%overs);
}

sub config_pre_load
{
my ($modconf_info) = @_;
my $mysql_module_version = &get_mysql_version();

# Replace config labels for MySQL
if ($mysql_module_version =~ /mariadb/i) {
	foreach my $confline (keys %{$modconf_info}) {
		$modconf_info->{$confline} =~ s/MySQL/MariaDB/g;
		}
	}
}

sub help_pre_load
{
my ($htext) = @_;
my $mysql_module_version = &get_mysql_version();

# Replace config labels for MySQL
if ($mysql_module_version =~ /mariadb/i) {
	$htext =~ s/MySQL/MariaDB/gm;
	}
return $htext;
}

# mysql_login_type(user)
# Returns one of 'password' or 'socket'
sub mysql_login_type
{
my ($user) = @_;
my $rv;
eval {
	local $main::error_must_die = 1;
	$rv = &execute_sql_safe($master_db, "select plugin from user where user = ?", $user);
	};
return 'password' if ($@);	# Old version without plugins
return $rv->{'data'}->[0]->[0] =~ /unix_socket/i ? 'socket' : 'password';
}

# list_authentication_plugins()
# Returns a list of supported authentication plugins for setting passwords
sub list_authentication_plugins
{
my ($ver, $variant) = &get_remote_mysql_variant();
if ($variant eq "mariadb" && &compare_version_numbers($ver, "10.4") >= 0 ||
    $variant eq "mysql" && &compare_version_numbers($ver, "5.7.6") >= 0) {
	return ('mysql_native_password', 'caching_sha2_password', 'unix_socket');
	}
return ();
}

# format_privs(&privs, &privs_fields)
# Returns best formatted string for a set of privileges
sub format_privs
{
my ($privs, $privs_fields) = @_;
my @privs_all = map { lc($_->[1]) } @{$privs_fields};
my @privs_cur = map { lc($_) } @{$privs};
my $simplify_privs = sub {
	my @privs = @_;
	my %groups = (
		'table_data' => [],
		'tables' => [],
		'view' => [],
		'routine' => [],
		'replication' => [],
	);
	my @others = ();
	foreach my $priv (@privs) {
		if ($priv =~ /^(select|insert|update|delete) table data$/) {
			push(@{$groups{'table_data'}}, $1);
			}
		elsif ($priv =~ /^(create|drop|alter|create temp|create temporary|lock) tables$/) {
			push(@{$groups{'tables'}}, $1);
			}
		elsif ($priv =~ /^(create|show) view$/) {
			push(@{$groups{'view'}}, $1);
			}
		elsif ($priv =~ /^(create|alter) routine$/) {
			push(@{$groups{'routine'}}, $1);
			}
		elsif ($priv =~ /^(slave|client) replication$/) {
			push(@{$groups{'replication'}}, $1);
			}
		else {
			push(@others, $priv);
			}
		}
	# Simplify groups
	my @simplified = ();
	# Helper function to format group
	my $format_group = sub {
		my ($group, $suffix) = @_;
		my $str = join(', ', @$group);
		$str =~ s/(.*),/$1 $text{'dbs_except_and'}/ if (@$group > 1);
		return $str . ($suffix ? " $suffix" : '');
		};
	# Handle each group
	push(@simplified, $format_group->($groups{'table_data'}, 'table data'))
		if (@{$groups{'table_data'}});
	push(@simplified, $format_group->($groups{'tables'}, 'tables'))
		if (@{$groups{'tables'}});
	push(@simplified, $format_group->($groups{'view'}, 'view'))
		if (@{$groups{'view'}});
	push(@simplified, $format_group->($groups{'routine'}, 'routine'))
		if (@{$groups{'routine'}});
	push(@simplified, $format_group->($groups{'replication'}, 'replication'))	
		if (@{$groups{'replication'}});
	# Add other privileges
	push(@simplified, @others);
	return join('; ', @simplified);
	};

if (@privs_cur >= int(0.7 * @privs_all)) {
	my %missing = map { $_ => 1 } @privs_all;
	delete(@missing{@privs_cur});
	my @missing_privs = keys %missing;
	my $missing_formatted = $simplify_privs->(@missing_privs);
	if (@missing_privs > 1) {
		$privs_formatted = "$text{'dbs_except'} ($missing_formatted)";
		}
	else {
		$privs_formatted = "$text{'dbs_except'} $missing_formatted";
		}
	}
else {
	$privs_formatted = $simplify_privs->(@privs_cur);
	}
return ucfirst($privs_formatted);
}

1;

