<?php
/***************************************************************************
 *                                session.php
 *                            -------------------
 *   begin                : Saturday, Feb 13, 2001
 *   copyright            : (C) 2002 The phpBB Group
 *   email                : support@phpbb.com
 *
 *   $Id$
 *
 ***************************************************************************/

/***************************************************************************
 *
 *   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.
 *
 ***************************************************************************/

class session
{
	var $session_id = '';
	var $data = array();
	var $browser = '';
	var $ip = '';
	var $page = '';
	var $load;

	// Called at each page start ... checks for, updates and/or creates a session
	function start($update = true)
	{
		global $SID, $db, $config;

		$current_time = time();
		$this->browser = ( !empty($_SERVER['HTTP_USER_AGENT']) ) ? $_SERVER['HTTP_USER_AGENT'] : $_ENV['HTTP_USER_AGENT'];
		$this->page = ( !empty($_SERVER['PHP_SELF']) ) ? $_SERVER['PHP_SELF'] : $_ENV['PHP_SELF'];
		$this->page .= '&' . ( ( !empty($_SERVER['QUERY_STRING']) ) ? $_SERVER['QUERY_STRING'] : $_ENV['QUERY_STRING'] );

		if ( isset($_COOKIE[$config['cookie_name'] . '_sid']) || isset($_COOKIE[$config['cookie_name'] . '_data']) )
		{
			$sessiondata = ( isset($_COOKIE[$config['cookie_name'] . '_data']) ) ? unserialize(stripslashes($_COOKIE[$config['cookie_name'] . '_data'])) : '';
			$this->session_id = ( isset($_COOKIE[$config['cookie_name'] . '_sid']) ) ? $_COOKIE[$config['cookie_name'] . '_sid'] : '';
			$SID = (defined('IN_ADMIN')) ? '?sid=' . $this->session_id : '?sid=';
		}
		else
		{
			$sessiondata = '';
			$this->session_id = ( isset($_GET['sid']) ) ? $_GET['sid'] : '';
			$SID = '?sid=' . $this->session_id;
		}

		// Obtain users IP
		$this->ip = ( !empty($_SERVER['REMOTE_ADDR']) ) ? $_SERVER['REMOTE_ADDR'] : $REMOTE_ADDR;

		if (!empty($_SERVER['HTTP_X_FORWARDED_FOR']))
		{
			if ( preg_match('/^([0-9]+\.[0-9]+\.[0-9]+\.[0-9]+)/', $_SERVER['HTTP_X_FORWARDED_FOR'], $ip_list) )
			{
				$private_ip = array('/^0\./', '/^127\.0\.0\.1/', '/^192\.168\..*/', '/^172\.16\..*/', '/^10\..*/', '/^224\..*/', '/^240\..*/');
				$this->ip = preg_replace($private_ip, $this->ip, $ip_list[1]);
			}
		}

		// Load limit check (if applicable)
		if ( doubleval($config['limit_load']) && file_exists('/proc/loadavg') )
		{
			if ( $load = @file('/proc/loadavg') )
			{
				list($this->load) = explode(' ', $load[0]);

				if ( $this->load > doubleval($config['limit_load']) )
				{
					trigger_error('Board_unavailable');
				}
			}
		}

		// session_id exists so go ahead and attempt to grab all data in preparation
		if ( !empty($this->session_id) )
		{
			$sql = "SELECT u.*, s.*
				FROM " . SESSIONS_TABLE . " s, " . USERS_TABLE . " u
				WHERE s.session_id = '" . $this->session_id . "'
					AND u.user_id = s.session_user_id";
			$result = $db->sql_query($sql);

			$this->data = $db->sql_fetchrow($result);
			$db->sql_freeresult($result);

			// Did the session exist in the DB?
			if ( isset($this->data['user_id']) )
			{
				// Validate IP length according to admin ... has no effect on IPv6
				$s_ip = implode('.', array_slice(explode('.', $this->data['session_ip']), 0, $config['ip_check']));
				$u_ip = implode('.', array_slice(explode('.', $this->ip), 0, $config['ip_check']));

				if ( $u_ip == $s_ip )
				{
					// Only update session DB a minute or so after last update or if page changes
					if ( ( $current_time - $this->data['session_time'] > 60 || $this->data['session_page'] != $user_page ) && $update )
					{
						$sql = "UPDATE " . SESSIONS_TABLE . "
							SET session_time = $current_time, session_page = '$this->page'
							WHERE session_id = '" . $this->session_id . "'";
						$db->sql_query($sql);
					}

					return true;
				}
			}
		}

		// If we reach here then no (valid) session exists. So we'll create a new one,
		// using the cookie user_id if available to pull basic user prefs.
		$autologin = ( isset($sessiondata['autologinid']) ) ? $sessiondata['autologinid'] : '';
		$user_id = ( isset($sessiondata['userid']) ) ? intval($sessiondata['userid']) : ANONYMOUS;

		return $this->create($user_id, $autologin);
	}

	// Create a new session
	function create(&$user_id, &$autologin)
	{
		global $SID, $db, $config;

		$sessiondata = array();
		$current_time = time();

		if ( intval($config['active_sessions']) )
		{
			// Limit sessions in 1 minute period
			$sql = "SELECT COUNT(*) AS sessions
				FROM " . SESSIONS_TABLE . "
				WHERE session_time >= " . ( $current_time - 60 );
			$result = $db->sql_query($sql);

			$row = $db->sql_fetchrow($result);
			$db->sql_freeresult($result);

			if ( intval($row['sessions']) > intval($config['active_sessions']) )
			{
				trigger_error('Board_unavailable');
			}
		}

		// Garbage collection ... remove old sessions updating user information
		// if necessary. It means (potentially) 22 queries but only infrequently
		if ( $current_time - $config['session_gc'] > $config['session_last_gc'] )
		{
			$this->gc($current_time);
		}

		// Grab user data ... join on session if it exists for session time
		$sql = "SELECT u.*, s.session_time
			FROM ( " . USERS_TABLE . " u
			LEFT JOIN " . SESSIONS_TABLE . " s ON s.session_user_id = u.user_id )
			WHERE u.user_id = $user_id
			ORDER BY s.session_time DESC";
		$result = $db->sql_query($sql);

		$this->data = $db->sql_fetchrow($result);
		$db->sql_freeresult($result);

		// Check autologin request, is it valid?
		if ( $this->data['user_password'] != $autologin || !$this->data['user_active'] || !$user_id )
		{
			$autologin = '';
			$this->data['user_id'] = $user_id = ANONYMOUS;
		}

		$sql = "SELECT ban_ip, ban_userid, ban_email
			FROM " . BANLIST_TABLE . "
			WHERE ban_end >= $current_time
				OR ban_end = 0";
		$result = $db->sql_query($sql);

		while ( $row = $db->sql_fetchrow($result) )
		{
			if ( ( $row['user_id'] == $this->data['user_id'] ||
				( $row['ban_ip'] && preg_match('#^' . str_replace('*', '.*?', $row['ban_ip']) . '$#i', $this->ip) ) ||
				( $row['ban_email'] && preg_match('#^' . str_replace('*', '.*?', $row['ban_email']) . '$#i', $this->data['user_email']) ) )
				&& !$this->data['user_founder'] )
			{
				trigger_error('You_been_banned');
			}
		}
		$db->sql_freeresult($result);

		// Is there an existing session? If so, grab last visit time from that
		$this->data['session_last_visit'] = ( $this->data['session_time'] ) ? $this->data['session_time'] : ( ( $this->data['user_lastvisit'] ) ? $this->data['user_lastvisit'] : time() );

		// Create or update the session
		$db->sql_return_on_error(true);

		$sql = "UPDATE " . SESSIONS_TABLE . "
			SET session_user_id = $user_id, session_last_visit = " . $this->data['session_last_visit'] . ", session_start = $current_time, session_time = $current_time, session_browser = '$this->browser', session_page = '$this->page'
			WHERE session_id = '" . $this->session_id . "'";
		if ( !$db->sql_query($sql) || !$db->sql_affectedrows() )
		{
			$db->sql_return_on_error(false);
			$this->session_id = md5(uniqid($user_ip));

			$sql = "INSERT INTO " . SESSIONS_TABLE . "
				(session_id, session_user_id, session_last_visit, session_start, session_time, session_ip, session_browser, session_page)
				VALUES ('" . $this->session_id . "', $user_id, " . $this->data['session_last_visit'] . ", $current_time, $current_time, '$this->ip', '$this->browser', '$this->page')";
			$db->sql_query($sql);
		}
		$db->sql_return_on_error(false);

		$this->data['session_id'] = $this->session_id;

		$sessiondata['autologinid'] = ( $autologin && $user_id ) ? $autologin : '';
		$sessiondata['userid'] = $user_id;

		$this->set_cookie('data', serialize($sessiondata), $current_time + 31536000);
		$this->set_cookie('sid', $this->session_id, 0);
		$SID = '?sid=' . $this->session_id;

		if ( $this->data['user_id'] )
		{
			// Events ... ?
//			do_events('days');

			// First page ... ?
//			if (!empty($this->data['user_firstpage']))
//			{
//				redirect($userdata['user_firstpage']);
//			}
		}

		return true;
	}

	// Destroy a session
	function destroy()
	{
		global $SID, $db, $config;

		$current_time = time();

		$this->set_cookie('data', '', $current_time - 31536000);
		$this->set_cookie('sid', '', $current_time - 31536000);
		$SID = '?sid=';

		// Delete existing session, update last visit info first!
		$sql = "UPDATE " . USERS_TABLE . "
			SET user_lastvisit = " . intval($this->data['session_time']) . "
			WHERE user_id = " . $this->data['user_id'];
		$db->sql_query($sql);

		$sql = "DELETE FROM " . SESSIONS_TABLE . "
			WHERE session_id = '" . $this->session_id . "'
				AND session_user_id = " . $this->data['user_id'];
		$db->sql_query($sql);

		$this->session_id = '';

		return true;
	}

	// Garbage collection
	function gc(&$current_time)
	{
		global $db, $config;

		// Get expired sessions, only most recent for each user
		$sql = "SELECT session_user_id, MAX(session_time) AS recent_time
			FROM " . SESSIONS_TABLE . "
			WHERE session_time < " . ( $current_time - $config['session_length'] ) . "
			GROUP BY session_user_id
			LIMIT 5";
		$result = $db->sql_query($sql);

		$del_user_id = '';
		$del_sessions = 0;
		while ( $row = $db->sql_fetchrow($result) )
		{
			if ( $row['session_user_id'] )
			{
				$sql = "UPDATE " . USERS_TABLE . "
					SET user_lastvisit = " . $row['recent_time'] . "
					WHERE user_id = " . $row['session_user_id'];
				$db->sql_query($sql);
			}

			$del_user_id .= ( ( $del_user_id != '' ) ? ', ' : '' ) . ' \'' . $row['session_user_id'] . '\'';
			$del_sessions++;
		}

		if ( $del_user_id != '' )
		{
			// Delete expired sessions
			$sql = "DELETE FROM " . SESSIONS_TABLE . "
				WHERE session_user_id IN ($del_user_id)
					AND session_time < " . ( $current_time - $config['session_length'] );
			$db->sql_query($sql);
		}

		if ( $del_sessions < 5 )
		{
			// Less than 5 sessions, update gc timer ... else we want gc
			// called again to delete other sessions
			$sql = "UPDATE " . CONFIG_TABLE . "
				SET config_value = '$current_time'
				WHERE config_name = 'session_last_gc'";
			$db->sql_query($sql);
		}

		return;
	}

	// Set a cookie
	function set_cookie($name, $cookiedata, $cookietime)
	{
		global $config;

		setcookie($config['cookie_name'] . '_' . $name, $cookiedata, $cookietime, $config['cookie_path'], $config['cookie_domain'], $config['cookie_secure']);
	}
}

// Contains (at present) basic user methods such as configuration
// creating date/time ... keep this?
class user extends session
{
	var $lang = array();
	var $theme = array();
	var $date_format;
	var $timezone;
	var $dst;

	var $lang_name;
	var $lang_path;
	var $img_lang;

	function setup($lang_set = false, $style = false)
	{
		global $db, $template, $config, $phpEx, $phpbb_root_path;

		if ( $this->data['user_id'] != ANONYMOUS )
		{
			$this->lang_name = ( file_exists($phpbb_root_path . 'language/' . $this->data['user_lang']) ) ? $this->data['user_lang'] : $config['default_lang'];
			$this->lang_path = $phpbb_root_path . 'language/' . $this->lang_name . '/';

			$this->date_format = $this->data['user_dateformat'];
			$this->timezone = $this->data['user_timezone'] * 3600;
			$this->dst = $this->data['user_dst'] * 3600;
		}
		else
		{
			$this->lang_name = $config['default_lang'];
			$this->lang_path = $phpbb_root_path . 'language/' . $this->lang_name . '/';
			$this->date_format = $config['default_dateformat'];
			$this->timezone = $config['board_timezone'] * 3600;
			$this->dst = 0;

			if ( isset($_SERVER['HTTP_ACCEPT_LANGUAGE']) )
			{
				$accept_lang_ary = explode(',', $_SERVER['HTTP_ACCEPT_LANGUAGE']);
				foreach ( $accept_lang_ary as $accept_lang )
				{
					// Set correct format ... guess full xx_YY form
					$accept_lang = substr($accept_lang, 0, 2) . '_' . strtoupper(substr($accept_lang, 3, 2));
					if ( file_exists($phpbb_root_path . 'language/' . $accept_lang) )
					{
						$this->lang_name = $accept_lang;
						$this->lang_path = $phpbb_root_path . 'language/' . $accept_lang . '/';
						break;
					}
					else
					{
						// No match on xx_YY so try xx
						$accept_lang = substr($accept_lang, 0, 2);
						if ( file_exists($phpbb_root_path . 'language/' . $accept_lang) )
						{
							$this->lang_name = $accept_lang;
							$this->lang_path = $phpbb_root_path . 'language/' . $accept_lang . '/';
							break;
						}
					}
				}
			}
		}

		include($this->lang_path . 'lang_main.' . $phpEx);
		if ( defined('IN_ADMIN') )
		{
			include($this->lang_path . 'lang_admin.' . $phpEx);
		}
		$this->lang = &$lang;

/*
		if ( is_array($lang_set) )
		{
			include($this->lang_path . '/common.' . $phpEx);

			$lang_set = explode(',', $lang_set);
			foreach ( $lang_set as $lang_file )
			{
				include($this->lang_path . '/' . $lang_file . '.' . $phpEx);
			}
			unset($lang_set);
		}
		else
		{
			include($this->lang_path . '/common.' . $phpEx);
			include($this->lang_path . '/' . $lang_set . '.' . $phpEx);
		}
*/
		// Set up style
		$style = ( $style ) ? $style : ( ( !$config['override_user_style'] && $this->data['user_id'] ) ? $this->data['user_style'] : $config['default_style'] );

		$sql = "SELECT t.template_path, t.poll_length, t.pm_box_length, c.css_data, c.css_external, i.*
			FROM " . STYLES_TABLE . " s, " . STYLES_TPL_TABLE . " t, " . STYLES_CSS_TABLE . " c, " . STYLES_IMAGE_TABLE . " i
			WHERE s.style_id = $style
				AND t.template_id = s.template_id
				AND c.theme_id = s.style_id
				AND i.imageset_id = s.imageset_id";
		$result = $db->sql_query($sql);

		if ( !($this->theme = $db->sql_fetchrow($result)) )
		{
			message_die(ERROR, 'Could not get style data');
		}

		$template->set_template($this->theme['template_path']);

		$this->img_lang = ( file_exists($phpbb_root_path . 'imagesets/' . $this->theme['imageset_path'] . '/' . $this->lang_name) ) ? $this->lang_name : $config['default_lang'];

		return;
	}

	function format_date($gmepoch, $format = false)
	{
		static $lang_dates;

		if ( empty($lang_dates) )
		{
			foreach ( $this->lang['datetime'] as $match => $replace )
			{
				$lang_dates[$match] = $replace;
			}
		}

		$format = ( !$format ) ? $this->date_format : $format;
		return strtr(@gmdate($format, $gmepoch + $this->timezone + $this->dst), $lang_dates);
	}

	function img($img, $alt = '', $width = false, $no_cache = false)
	{
		static $imgs;

		if (empty($imgs[$img]) || $no_cache)
		{
			$width = ( $width ) ? 'width="' . $width . '" ' : '';
			$imgs[$img] = '<img src=' . str_replace('{LANG}', $this->img_lang, $this->theme[$img]) . '" ' . $width . 'alt="' . $this->lang[$alt] . '" title="' . $this->lang[$alt] . '" />';
		}

		return $imgs[$img];
	}
}

// Will be keeping my eye of 'other products' to ensure these things don't
// mysteriously appear elsewhere, think up your own solutions!
class auth
{
	var $founder = false;
	var $acl = array();
	var $acl_options = array();

	function acl(&$userdata, $forum_id = false)
	{
		global $db, $acl_options;

		$this->acl_options = &$acl_options;

		if (!$this->founder = $userdata['user_founder'])
		{
//			$mtime = explode(' ', microtime());
//			$starttime = $mtime[1] + $mtime[0];

			if ( empty($userdata['user_permissions']) )
			{
				$this->acl_cache($userdata);
			}

			// This is preliminary and can no doubt be improved
			$global_chars = ceil(sizeof($this->acl_options['global']) / 8);
			$local_chars = ceil(sizeof($this->acl_options['local']) / 8) + 2;
			$globals = substr($userdata['user_permissions'], 0, $global_chars);
			$locals = substr($userdata['user_permissions'], $global_chars);

			for($i = 0; $i < $global_chars; $i++)
			{
				$this->acl['global'] .= str_pad(decbin(ord(substr($globals, $i, 1))), 8, 0, STR_LEFT_PAD);
			}

			$forums = explode("\r\n", chunk_split($locals, $local_chars));
			array_pop($forums);
			foreach ( $forums as $forum )
			{
				$forum_id = bindec(decbin(ord(substr($forum, 0, 1))) . str_pad(decbin(ord(substr($forum, 1, 1))), 8, 0, STR_PAD_LEFT));

				for($i = 2; $i < $local_chars; $i++)
				{
					$this->acl['local'][$forum_id] .= str_pad(decbin(ord(substr($forum, $i, 1))), 8, 0, STR_PAD_LEFT);
				}
			}
			unset($forums);
		}

//		$mtime = explode(' ', microtime());
//		echo $mtime[1] + $mtime[0] - $starttime . " :: ";

		return;
	}

	// Look up an option
	function acl_get($option, $forum_id = 0)
	{
		static $acl_cache;

		if ( !isset($acl_cache[$forum_id][$option]) && !$this->founder )
		{
			if ( isset($this->acl_options['global'][$option]) )
			{
				$acl_cache[$forum_id][$option] = substr($this->acl['global'], $this->acl_options['global'][$option], 1);
			}
			if ( isset($this->acl_options['local'][$option]) )
			{
				$acl_cache[$forum_id][$option] |= substr($this->acl['local'][$forum_id], $this->acl_options['local'][$option], 1);
			}
		}

		return ( $this->founder ) ? true : $acl_cache[$forum_id][$option];
	}

	// Cache data
	function acl_cache(&$userdata)
	{
		global $db;

		$acl_db = array();

		$sql = "SELECT a.forum_id, a.auth_allow_deny, ao.auth_value
			FROM " . ACL_GROUPS_TABLE . " a, " . ACL_OPTIONS_TABLE . " ao, " . USER_GROUP_TABLE . " ug
			WHERE ug.user_id = " . $userdata['user_id'] . "
				AND a.group_id = ug.group_id
				AND ao.auth_option_id = a.auth_option_id";
		$result = $db->sql_query($sql);

		while ( $row = $db->sql_fetchrow($result) )
		{
			$acl_db[] = $row;
		}
		$db->sql_freeresult($result);

		$sql = "SELECT a.forum_id, a.auth_allow_deny, ao.auth_option_id, ao.auth_value
			FROM " . ACL_USERS_TABLE . " a, " . ACL_OPTIONS_TABLE . " ao
			WHERE a.user_id = " . $userdata['user_id'] . "
				AND ao.auth_option_id = a.auth_option_id";
		$result = $db->sql_query($sql);

		while ( $row = $db->sql_fetchrow($result) )
		{
			$acl_db[] = $row;
		}
		$db->sql_freeresult($result);

		if ( is_array($acl_db) )
		{
			sort($acl_db);

			foreach ( $acl_db as $row )
			{
				if ( $row['auth_allow_deny'] != ACL_INHERIT && $this->acl[$row['forum_id']][$row['auth_value']] !== ACL_DENY )
				{
					$this->acl[$row['forum_id']][$row['auth_value']] = intval($row['auth_allow_deny']);
				}
			}
			unset($acl_db);

			$global_bits = 8 * ceil(sizeof($this->acl_options['global']) / 8);
			$local_bits = 8 * ceil(sizeof($this->acl_options['local']) / 8 );
			$local_hold = '';
			$global_hold = '';

			foreach ( $this->acl as $forum_id => $auth_ary )
			{
				$holding = array();
				$option_set = array();

				if ( !$forum_id )
				{
					$fill = $global_bits;
					$ary_key = 'global';
					$hold_str = 'global_hold';
				}
				else
				{
					$fill = $local_bits;
					$ary_key = 'local';
					$hold_str = 'local_hold';
				}

				for($i = 0; $i < $fill; $i++)
				{
					$holding[$i] = 0;
				}

				foreach ( $auth_ary as $option => $allow )
				{
					if ( $allow )
					{
						$holding[$this->acl_options[$ary_key][$option]] = 1;

						$option_key = substr($option, 0, strpos($option, '_') + 1);
						if ( empty($holding[$this->acl_options[$ary_key][$option_key]]) )
						{
							$holding[$this->acl_options[$ary_key][$option_key]] = 1;
						}
					}
				}

				$forum_id = ( $forum_id ) ? str_pad(decbin($forum_id), 16, 0, STR_PAD_LEFT) : '';
				$bitstring = explode("\r\n", chunk_split($forum_id . implode('', $holding), 8));
				array_pop($bitstring);

				foreach ( $bitstring as $byte )
				{
					$$hold_str .= chr(bindec($byte));
				}
			}
			unset($holding);

			if ( $global_hold == '' )
			{
				for($i = 0; $i < $global_bits; $i++)
				{
					$global_hold .= '0';
				}
			}

			$userdata['user_permissions'] .= $global_hold . $local_hold;
			unset($global_hold);
			unset($local_hold);

			$sql = "UPDATE " . USERS_TABLE . "
				SET user_permissions = '" . addslashes($userdata['user_permissions']) . "'
				WHERE user_id = " . $userdata['user_id'];
			$db->sql_query($sql);
		}

		return;
	}

	// Authentication plug-ins is largely down to Sergey Kanareykin, our thanks to him.
	function login($username, $password, $autologin = false)
	{
		global $config, $user, $phpEx;

		$method = trim($config['auth_method']);

		if ( file_exists('includes/auth/auth_' . $method . '.' . $phpEx) )
		{
			include_once('includes/auth/auth_' . $method . '.' . $phpEx);

			$method = 'login_' . $method;
			if ( function_exists($method) )
			{
				if ( !($login = $method($username, $password)) )
				{
					return false;
				}

				$autologin = ( isset($autologin) ) ? md5($password) : '';
				return ( $login['user_active'] ) ? $user->create($login['user_id'], $autologin) : false;
			}
		}

		trigger_error('Authentication method not found', E_USER_ERROR);
	}
}

?>