<?php
/**
* $Id: ip_login.module,v 1.1.4.5 2008/11/15 04:37:16 davidwhthomas Exp $
* Allow user login by IP Address
*/

/**
 * Implementation of hook_init
 */
function ip_login_init(){
  global $user;
  //call ip login on init for any page, if not already processed
  if( ! $user->uid && variable_get('ip_login_enabled',1) && ! $_SESSION['ip_login_complete']){
    ip_login_login($_SERVER['REMOTE_ADDR']);
  }
}

/**
 * Implementation of hook_menu
 */
function ip_login_menu(){
  $items['admin/settings/iplogin'] = array(
      'title' => t('IP Login Settings'),
      'description' => t('configure IP login settings'),
      'access callback' => 'user_access',
      'access arguments' => array('administer site configuration'),
      'page callback' => 'drupal_get_form',
      'page arguments' => array('ip_login_admin_settings'),
      'type' => MENU_NORMAL_ITEM,
    );
  return $items;
}

function ip_login_admin_settings(){
  
  $result = db_query("SELECT DISTINCT name FROM {profile_fields}");
  while($field = db_fetch_object($result)){
    $fields[$field->name] = $field->name;
  }
  if( ! $fields || ! variable_get('ip_login_profile_ip_field','')){
    drupal_set_message(t('You can use the !profile_module to add a text field to the user profile to store the user ip address.', array('!profile_module'=> l('profile module admin', 'admin/user/profile/add/textfield')))); 
  }
  $form['info'] = array(
    '#type' => 'markup',
    '#value' => 'This module allows users to login automatically by IP address. The IP address value stored in a user\'s profile, using the \'profile\' module, is used to authenticate and login that user when visiting from that address. Addresses like 203.123.456.789 and also ranges like 203.123.456.* are supported.'
  );
  $form['ip_login_enabled'] = array(
    '#type' => 'checkbox',
    '#title' => t('IP Login enabled'),
    '#description' => t('Check to enable IP Login, uncheck to disable. If unchecked no user will be able to login via IP address.'),
    '#default_value' => variable_get('ip_login_enabled',1)
  );
  $form['ip_login_profile_ip_field'] = array(
    '#type' => 'select',
    '#title' => t('Profile module IP address field'),
    '#description' => t('Select the profile field containing the user IP address.'),
    '#options' => $fields,
    '#default_value' => variable_get('ip_login_profile_ip_field','profile_ip')
  );
  return system_settings_form($form);
}


/**
 * Log user in by ip address and profile_ip profile field
 * @param string $ip ip address
 * @return void
 */
function ip_login_login($ip){

  //get wildcard IP for fuzzy range matches e.g 203.123.456.*
  $ip_range = ip_login_get_range($ip);
  
  //get profile field for ip address
  $profile_field = variable_get('ip_login_profile_ip_field', 'profile_ip');
  
  //DB lookup uid with passed ip address or range
  $result = db_fetch_object(
    db_query("SELECT pv.uid, pv.value FROM {profile_values} pv
             INNER JOIN {profile_fields} pf ON pv.fid = pf.fid
             WHERE pf.name = '%s' AND (pv.value = '%s' OR pv.value = '%s')", $profile_field, $ip, $ip_range)
  );
  //if a uid is returned with the passed ip address and user_load is available
  if($result && function_exists("user_load")){
    //if can load user from uid where user status is active
    if ($account = user_load(array('uid' => $result->uid, 'status' => 1))) {
      //login by assigning account to global $user object
      global $user;
      $user = $account; //this part logs the user in
      $message = t('Welcome %name. You are now logged into %sitename.',
                    array(
                      '%name' => $user->name,
                      '%sitename' => variable_get('site_name', 'this website')
                    )
                  );
      //set welcome message
      drupal_set_message($message);
      $message = t('Session opened for %name.', array('%name' => $user->name));
      //log login event message
      watchdog('user', $message);
      // Update the user table timestamp noting user has logged in.
      db_query("UPDATE {users} SET login = %d WHERE uid = %d", time(), $user->uid);
      //IMPORTANT: drupal call to regenerate session data for anon user to authenticated user
      sess_regenerate();
    }
      //set processed session flag
      $_SESSION['ip_login_complete'] = 1;
  }else{
    return false; //try again later
  }

}

/*
 * Return ip range from ip address
 * @param string $ip ip address
 * @return string $ip ip address with wildcard *
 *
*/
function ip_login_get_range($ip){
  if($ip){
    $ip = explode('.', $ip); //explode ip to array
    array_pop($ip); //remove last element
    $ip = implode('.', $ip).'.*'; //convert to string and add .*
  }
  return $ip;
}