<?php
//          FILE: class_sbdns.php
//
// LAST MODIFIED: 2006-03-23 07:45
//
//        AUTHOR: Troy Wolf <troy@troywolf.com>
//
//   DESCRIPTION: PHP class to automate use of Server Beach's DNS Tool.
//                This class emulates 100% of the DNS Tool functionality.
//                Although this class works well, the hope is that this
//                class will be made obsolete by SB eventually developing
//                an API to the DNS Tool.
//
//         USAGE: See documentation at http://www.troywolf.com/articles/php/class_sbdns
// 
//         NOTES: The class attempts to validate the values you pass to the methods.
//                If any problems are found, $sbdns->status_msg is set with a 
//                description of the problem and the method returns FALSE.
//                The class tries to be smart about everything, but please don't
//                go blindly executing commands against the Server Beach DNS
//                servers! If you have problems with the code, echo 
//                $sbdns->status_msg to get an indication of the failure.
//                You may also find $sbdns->dump() handy for debugging. 
//                If you need support, feel free to email the author.

// sbdns requires Troy's class_http. http://www.troywolf.com/articles
// Alter the path according to your environment.
require_once("class_http.php");

// PHP Class to automate Server Beach DNS Tool methods.
class sbdns
{
    // Class constructor. Edit with your email and password.
    // Optionally, you can pass in a delay factor, but you probably do not need
    // to. See below for more details regarding delay_factor.
    function sbdns($delay_factor=1)
    {
        // Change the next 2 lines to reflect your SB login credentials.
        $this->auth_email = "me@mydomain.com";
        $this->auth_pass = "mypassword";

        // You can optionally pass in a delay_factor of 1 or greater.
        // This will increase the time the class waits between page hits.
        // Currently most hits are set to wait 1/2 second. So passing in a
        // value of 2 will make most hits wait 1 full second. If you are having
        // timing-related problems, increasing this value could solve them.
        $this->delay_factor = $delay_factor / 1;

        $this->status_msg = "OK";
        $this->phpsessid = "";
    }

    // Emulate the My Server Beach login process and setup to use the
    // DNS Tool. 
    function login()
    {
        // Instantiate the http object used to make the web requests.
        // More info about this object at www.troywolf.com/articles
        if (!$this->http = new http()) {
            $this->status_msg = "Failed to create http object.";
            return false;
        }

        // Step 1: Hit SB login page to initialize phpsessid and cookie.
        $this->url = "https://secure.serverbeach.com:443/catalog/mysblogin.php";
        $this->http->headers['Referer'] = "http://www.serverbeach.com/catalog/";
        if (!$this->http->fetch($this->url)) {
            $this->status_msg = "Login step 1 https request failed.";
            return false;
        }
        // Find phpsessid cookie in headers.
        $ary_headers = split("\n", $this->http->header);
        foreach($ary_headers as $hdr) {
            if (eregi("^Set-Cookie\:", $hdr)) {
                $hdr = str_replace("Set-Cookie: ", "", $hdr);
                $ary_cookies = split(";", $hdr);
                $this->phpsessid = trim($ary_cookies[0]);
                break;
            }
        }
        // Did we fail to find the phpsessionid cookie?
        if (!$this->phpsessid) {
            $this->status_msg = "Login step 1 failed to set PHPSESSID cookie.";
            return false;
        }
        
        // Step 2. Authenticate by posting the login form along with the phpsessid.
        usleep(500000 * $this->delay_factor);
        $this->http->clean();
        $this->url = "https://secure.serverbeach.com/catalog/mysblogin.php?action=process&".$this->phpsessid;
        $this->http->headers['Referer'] = "https://secure.serverbeach.com/catalog/mysblogin.php";
        $this->http->headers['Cookie'] = $this->phpsessid;
        $this->http->postvars['email_address'] = $this->auth_email;
        $this->http->postvars['password'] = $this->auth_pass;
        $this->http->postvars['user'] = "returning";
        if (!$this->http->fetch($this->url)) {
            $this->status_msg = "Login step 2 https request failed.";
            return false;
        }
        // Did login fail?
        $ary_headers = split("\n", $this->http->header);
        foreach($ary_headers as $hdr) {
            if (eregi("^Location\:", $hdr)) {
                if (strpos($hdr, "login=fail") > 0) {
                    $this->status_msg = "SB login failed. Mostly likely because of incorrect email or password.";
                    return false;
                }
            }
        }

        // Step 3. Hit the My SB home page. Apparently, this sets some necessary
        // server-side session variables.
        usleep(500000 * $this->delay_factor);
        $this->http->clean();
        $this->url = "https://secure.serverbeach.com/mysb/index.php";
        $this->http->headers['Referer'] = "https://secure.serverbeach.com/mysb/index.php";
        $this->http->headers['Cookie'] = $this->phpsessid;
        if (!$this->http->fetch($this->url)) {
            $this->status_msg = "Login step 3 https request failed.";
            return false;
        }
        
        // Step 4. Hit the DNS Tool home page.
        usleep(500000 * $this->delay_factor);
        $this->http->clean();
        $this->url = "https://secure.serverbeach.com/mysb/dns/index.php";
        $this->http->headers['Referer'] = "https://secure.serverbeach.com/mysb/index.php";
        $this->http->headers['Cookie'] = $this->phpsessid;
        if (!$this->http->fetch($this->url)) {
            $this->status_msg = "Login step 4 https request failed.";
            return false;
        }

        return true;
    }

    // Add a new domain to the DNS setting SB as either Master or Slave.
    // $domain = domain name to add
    // $ip = IP where domain is hosted -or- IP of master DNS server.
    // $master = true/false, passing false means setup SB as slave.
    // NOTE: If you had previously set a domain, you'll need to reset it
    // after executing this method if you plan to execute more methods against
    // the previously set domain.
    function add_domain($domain, $ip, $master=true)
    {
        if (strlen($domain) == 0) {
            $this->status_msg = "Domain add failed because no domain passed in.";
            return false;
        }

        $domain = strtolower($domain);
        
        if (!ereg("^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$", $ip)) {
            $this->status_msg = "Domain add failed because invalid IP passed in.";
            return false;
        }
        
        // First check if domain already exists. If so, stop.
        // This adds a small time overhead, but is worthwhile to prevent stupid
        // mistakes.
        if ($this->set_domain($domain)) {
            $this->status_msg = "Domain add failed because domain '".$domain."' already exists.";
            return false;
        }
    
        // Step 1.
        usleep(500000 * $this->delay_factor);
        $this->http->clean();
        $this->url = "https://secure.serverbeach.com/mysb/dns/choose_master_slave.php";
        $this->http->headers['Referer'] = "https://secure.serverbeach.com/mysb/dns/index.php";
        $this->http->headers['Cookie'] = $this->phpsessid;
        // PLEASE do not change any of these values unless you really know what
        // you are doing and have permission from Server Beach.
        $this->http->postvars['info[command]'] = "add_zone";
        $this->http->postvars['info[class]'] = "IN";
        $this->http->postvars['info[ttl]'] = "86400";
        $this->http->postvars['info[source_dname]'] = "ns1.geodns.net";
        $this->http->postvars['info[owner_email]'] = "hostmaster@geodns.net";
        $this->http->postvars['info[serial]'] = "1";
        $this->http->postvars['info[refresh_time]'] = "10800";
        $this->http->postvars['info[transfer]'] = "3600";
        $this->http->postvars['info[expire_time]'] = "604800";
        $this->http->postvars['info[default_ttl]'] = "86400";
        $this->http->postvars['info[nameserver]'] = "ns1.geodns.net";
        $this->http->postvars['info[new_domain]'] = $domain;
        if (!$this->http->fetch($this->url)) {
            $this->status_msg = "Domain add step 1 https request failed.";
            return false;
        }
        
        if ($master) {
            // Use Server Beach as Master & Slave DNS.
            
            // Step 2.
            usleep(500000 * $this->delay_factor);
            $this->http->clean();
            $this->url = "https://secure.serverbeach.com/mysb/dns/add_zone_ip.php";
            $this->http->headers['Referer'] = "https://secure.serverbeach.com/mysb/dns/choose_master_slave.php";
            $this->http->headers['Cookie'] = $this->phpsessid;
            $this->http->postvars['command'] = "CHOOSE_DNS_TYPE";
            $this->http->postvars['info[dns_type]'] = "master";
            if (!$this->http->fetch($this->url)) {
                $this->status_msg = "Domain add master step 2 https request failed.";
                return false;
            }

            // Step 3.
            usleep(500000 * $this->delay_factor);
            $this->http->clean();
            $this->url = "https://secure.serverbeach.com/mysb/dns/add_zone_processor.php";
            $this->http->headers['Referer'] = "https://secure.serverbeach.com/mysb/dns/choose_master_slave.php";
            $this->http->headers['Cookie'] = $this->phpsessid;
            $this->http->postvars['info[address]'] = $ip;
            $this->http->postvars['confirmed'] = "true";
            if (!$this->http->fetch($this->url)) {
                $this->status_msg = "Domain add master step 3 https request failed.";
                return false;
            }


        } else {
            // Use Server Beach as Slave DNS only.
            
            // Step 2.
            usleep(500000 * $this->delay_factor);
            $this->http->clean();
            $this->url = "https://secure.serverbeach.com/mysb/dns/add_master_ip.php";
            $this->http->headers['Referer'] = "https://secure.serverbeach.com/mysb/dns/choose_master_slave.php";
            $this->http->headers['Cookie'] = $this->phpsessid;
            $this->http->postvars['command'] = "CHOOSE_DNS_TYPE";
            $this->http->postvars['info[dns_type]'] = "slave";
            if (!$this->http->fetch($this->url)) {
                $this->status_msg = "Domain add slave step 2 https request failed.";
                return false;
            }

            // Step 3.
            usleep(500000 * $this->delay_factor);
            $this->http->clean();
            $this->url = "https://secure.serverbeach.com/mysb/dns/add_master_processor.php";
            $this->http->headers['Referer'] = "https://secure.serverbeach.com/mysb/dns/choose_master_slave.php";
            $this->http->headers['Cookie'] = $this->phpsessid;
            $this->http->postvars['info[address]'] = $ip;
            $this->http->postvars['confirmed'] = "true";
            if (!$this->http->fetch($this->url)) {
                $this->status_msg = "Domain add slave step 3 https request failed.";
                return false;
            }
        }

        return true;        
    }

    // Delete an entire domain zone from the DNS.
    // This method, like most of the methods, requires you to first set the
    // target domain with set_domain().
    function delete_domain()
    {
        if (!$this->domain) {
            $this->status_msg = "Delete domain failed because domain is not set.";
            return false;
        }
        $this->http->clean();
        usleep(500000 * $this->delay_factor);
        $this->url = "https://secure.serverbeach.com/mysb/dns/wizard_del_domain.php";
        $this->http->headers['Referer'] = "https://secure.serverbeach.com/mysb/dns/wizard_del_domain.php";
        $this->http->headers['Cookie'] = $this->phpsessid;
        $this->http->postvars['confirmed'] = "true";
        if (!$this->http->fetch($this->url)) {
            $this->status_msg = "Delete domain https request failed.";
            return false;
        }

        return true;
    }


    // Set the current domain to issue commands against.
    // Most of the other methods require that you first set the domain with
    // this method. Same as clicking the "go" button next to a domain in the
    // DNS Tool.
    function set_domain($domain)
    {
        if (strlen($domain) == 0) {
            $this->status_msg = "Set domain failed because no domain passed in.";
            return false;
        }
        $this->zone = "";
        $this->records = array();
        $this->domain = $domain;
        usleep(500000 * $this->delay_factor);
        $this->http->clean();
        $this->url = "https://secure.serverbeach.com/mysb/dns/zone_list_processor.php";
        $this->http->headers['Referer'] = "https://secure.serverbeach.com/mysb/dns/index.php";
        $this->http->headers['Cookie'] = $this->phpsessid;
        $this->http->postvars['info[zone]'] = $this->domain.".";
        $this->http->postvars['action'] = "view_records";
        if (!$this->http->fetch($this->url)) {
            $this->status_msg = "Set domain https request failed.";
            return false;
        }
        if ($this->http->status == "302") {
            return true;
        } else {
            $this->status_msg = "Set domain could not find the domain.";
            return false;
            
        }
    }

    // Change the zone's hostmaster email address.
    function change_hostmaster_email($email_address)
    {
        if (!$this->domain) {
            $this->status_msg = "Change hostmaster email failed because domain is not set.";
            return false;
        }
        
        if(!eregi("^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3})$", $email_address)) {
            $this->status_msg = "Change hostmaster email failed because email address is invalid.";
            return false;
        }

        $email_address = strtolower($email_address);
    
        // Step 1.
        $this->http->clean();
        usleep(500000 * $this->delay_factor);
        $this->url = "https://secure.serverbeach.com/mysb/dns/wizard_change_email.php";
        $this->http->headers['Referer'] = "https://secure.serverbeach.com/mysb/dns/record_list.php";
        $this->http->headers['Cookie'] = $this->phpsessid;
        if (!$this->http->fetch($this->url)) {
            $this->status_msg = "Change hostmaster email step 1 https request failed.";
            return false;
        }

        // Step 2.
        $this->http->clean();
        usleep(500000 * $this->delay_factor);
        $this->url = "https://secure.serverbeach.com/mysb/dns/wizard_confirm_email.php";
        $this->http->headers['Referer'] = "https://secure.serverbeach.com/mysb/dns/wizard_change_email.php";
        $this->http->headers['Cookie'] = $this->phpsessid;
        $this->http->postvars['info[email_address]'] = $email_address;
        $this->http->postvars['confirmed'] = "true";
        if (!$this->http->fetch($this->url)) {
            $this->status_msg = "Change hostmaster email step 2 https request failed.";
            return false;
        }

        return true;
    }
    
    // Add an A or CNAME record to the domain zone.
    // If $target is missing, create CNAME for main domain.
    // If $target contains any alpha characters, create a CNAME for the target.
    // Else assume $target is an IP address and create an A record.
    function add_record($rec_name, $target="")
    {
        if (!$this->domain) {
            $this->status_msg = "Add record failed because domain is not set.";
            return false;
        }
        
        $rec_name = strtolower($rec_name);
        $target = strtolower($target);
        
        if (!$target) { $type_val = "current_domain"; }
        elseif (ereg("[a-z]", $target)) { $type_val = "new_domain"; }
        else { $type_val = "ip_addr"; };

        // Step 1.
        usleep(500000 * $this->delay_factor);
        $this->http->clean();
        $this->url = "https://secure.serverbeach.com/mysb/dns/wizard_sub_sub.php";
        $this->http->headers['Referer'] = "https://secure.serverbeach.com/mysb/dns/record_list.php";
        $this->http->headers['Cookie'] = $this->phpsessid;
        if (!$this->http->fetch($this->url)) {
            $this->status_msg = "Add mail exchanger step 1 https request failed.";
            return false;
        }

        // Step 2.
        usleep(500000 * $this->delay_factor);
        $this->http->clean();
        $this->url = "https://secure.serverbeach.com/mysb/dns/wizard_sub_processor.php";
        $this->http->headers['Referer'] = "https://secure.serverbeach.com/mysb/dns/wizard_sub_sub.php";
        $this->http->headers['Cookie'] = $this->phpsessid;
        $this->http->postvars['info[subdomain]'] = $rec_name;
        $this->http->postvars['info[sub_type]'] = $type_val;
        switch($type_val) {
        case "new_domain":
            $this->http->postvars['info[new_canonical_dname]'] = $target;
            break;
        case "ip_addr":
            $this->http->postvars['info[new_a_ip_address]'] = $target;
            break;
        }
        $this->http->postvars['confirmed'] = "true";
        if (!$this->http->fetch($this->url)) {
            $this->status_msg = "Add record step 2 https request failed.";
            return false;
        }

        return true;
    }

    // Change a record's target.
    // If you instead want to change a subdomain name, don't use this method.
    // Instead, delete the record you don't want and add the one you do want.
    function update_record($rec_name, $target="")
    {
        if (!$this->domain) {
            $this->status_msg = "Update record failed because domain is not set.";
            return false;
        }
       
        if (!$this->records) {
            if (!$this->get_record_ids()) {
                $this->status_msg = "Update record failed because get_record_ids failed.";
                return false;
            }
        }

        $rec_name = strtolower($rec_name);
        $target = strtolower($target);

        // Find record type and ID.
        $id = false;
        foreach($this->records['CNAME'] as $record) {
            if ($record['name'] == $rec_name) {
                $id = $record['id'];
                $rec_type = 'cname';
                break;
            }
        }
        if (!$id) {
            foreach($this->records['A'] as $record) {
            if (($record['name'] == $rec_name)
            || ($record['name'] == ($rec_name."."))) {
                    $id = $record['id'];
                    $rec_type = 'a';
                    break;
                }
            }
        }
        if (!$id) {
            $this->status_msg = "Update record failed because '".$rec_name
                ."' not found in your zone's A or CNAME records.";
            return false;
        }

        // Determine the target type based on $target param.
        if (!$target) { $type_val = "current_domain"; }
        elseif (ereg("[a-z]", $target)) { $type_val = "new_domain"; }
        else { $type_val = "ip_addr"; };

        // Check for attempt to convert A to CNAME -- no can do.
        if (($rec_type == "a") && ($type_val != "ip_addr")) {
            $this->status_msg = "Update record failed because you cannot convert"
                ." an A record to a CNAME. You must delete the A record, then"
                ." create a new CNAME record.";
            return false;
        }

        // Step 1. Set the record id to modify.
        usleep(500000 * $this->delay_factor);
        $this->http->clean();
        $this->url = "https://secure.serverbeach.com/mysb/dns/record_list_processor.php?type=".$rec_type."&id=".$id."&action=edit_sub";
        $this->http->headers['Referer'] = "https://secure.serverbeach.com/mysb/dns/record_list.php";
        $this->http->headers['Cookie'] = $this->phpsessid;
        if (!$this->http->fetch($this->url)) {
            $this->status_msg = "Update record step 1 https request failed.";
            return false;
        }

        // Step 2. Step 1 returns a redirect to this step -- does not work
        // without this step.
        usleep(500000 * $this->delay_factor);
        $this->http->clean();
        $this->url = "https://secure.serverbeach.com/mysb/dns/wizard_edsub_data.php";
        $this->http->headers['Referer'] = "https://secure.serverbeach.com/mysb/dns/record_list.php";
        $this->http->headers['Cookie'] = $this->phpsessid;
        if (!$this->http->fetch($this->url)) {
            $this->status_msg = "Update record step 2 https request failed.";
            return false;
        }

        // If converting a CNAME to an A, we have to do something a little different.
        if (($rec_type == "cname") && ($type_val == "ip_addr")) {
            // Step 3.
            usleep(500000 * $this->delay_factor);
            $this->http->clean();
            $this->url = "https://secure.serverbeach.com/mysb/dns/wizard_edsub_type.php";
            $this->http->headers['Referer'] = "https://secure.serverbeach.com/mysb/dns/wizard_edsub_ip.php";
            $this->http->headers['Cookie'] = $this->phpsessid;
            $this->http->postvars['sub_type'] = $type_val;
            if (!$this->http->fetch($this->url)) {
                $this->status_msg = "Update record step 3 https request failed.";
                return false;
            }

            // Step 4.
            usleep(500000 * $this->delay_factor);
            $this->http->clean();
            $this->url = "https://secure.serverbeach.com/mysb/dns/wizard_edsub_c_to_a_processor.php";
            $this->http->headers['Referer'] = "https://secure.serverbeach.com/mysb/dns/wizard_edsub_ip.php";
            $this->http->headers['Cookie'] = $this->phpsessid;
            $this->http->postvars['info[new_a_ip_address]'] = $target;
            $this->http->postvars['confirmed'] = "true";
            if (!$this->http->fetch($this->url)) {
                $this->status_msg = "Update record step 4 https request failed.";
                return false;
            }
        } else {
            // Step 3.
            usleep(500000 * $this->delay_factor);
            $this->http->clean();
            $this->url = "https://secure.serverbeach.com/mysb/dns/wizard_edsub_processor.php";
            $this->http->headers['Referer'] = "https://secure.serverbeach.com/mysb/dns/wizard_edsub_new.php";
            $this->http->headers['Cookie'] = $this->phpsessid;
            $this->http->postvars['sub_type'] = $type_val;
            switch($type_val) {
            case "new_domain":
                $this->http->postvars['info[new_canonical_dname]'] = $target;
                break;
            case "ip_addr":
                $this->http->postvars['info[new_a_ip_address]'] = $target;
                break;
            }
            $this->http->postvars['confirmed'] = "true";
            if (!$this->http->fetch($this->url)) {
                $this->status_msg = "Update record step 3 https request failed.";
                return false;
            }
        }

        return true;
    }

    // Delete a subdomain record. Only pass the sub name. That is, do not append
    // the domain name.
    function delete_record($rec_name)
    {
        if (!$this->domain) {
            $this->status_msg = "Delete record failed because domain is not set.";
            return false;
        }

        $rec_name = strtolower($rec_name);

        // Make sure rec_name is not the root domain record.
        if ($rec_name == $this->domain) {
            $this->status_msg = "Delete record failed because you cannot delete"
                ." the root domain for this zone.";
            return false;
        }

        if (!$this->records) {
            if (!$this->get_record_ids()) {
                $this->status_msg = "Delete record failed because get_record_ids failed.";
                return false;
            }
        }

        // Find record type and ID.
        $id = false;
        foreach($this->records['CNAME'] as $record) {
            if ($record['name'] == $rec_name) {
                $id = $record['id'];
                $rec_type = 'cname';
                break;
            }
        }
        if (!$id) {
            foreach($this->records['A'] as $record) {
                if ($record['name'] == $rec_name) {
                    $id = $record['id'];
                    $rec_type = 'a';
                    break;
                }
            }
        }
        if (!$id) {
            $this->status_msg = "Delete record failed because '".$rec_name."' not found in your zone's A or CNAME records.";
            return false;
        }
        
        // Step 1.
        $this->http->clean();
        usleep(500000 * $this->delay_factor);
        $this->url = "https://secure.serverbeach.com/mysb/dns/record_list_processor.php?type=".$rec_type."&id=".$id."&action=del_sub";
        $this->http->headers['Referer'] = "https://secure.serverbeach.com/mysb/dns/record_list.php";
        $this->http->headers['Cookie'] = $this->phpsessid;
        if (!$this->http->fetch($this->url)) {
            $this->status_msg = "Delete record step 1 https request failed.";
            return false;
        }

        // Step 2.
        $this->http->clean();
        usleep(500000 * $this->delay_factor);
        $this->url = "https://secure.serverbeach.com/mysb/dns/wizard_delsub_processor.php";
        $this->http->headers['Referer'] = "https://secure.serverbeach.com/mysb/dns/record_list.php";
        $this->http->headers['Cookie'] = $this->phpsessid;
        $this->http->postvars['confirmed'] = "true";
        if (!$this->http->fetch($this->url)) {
            $this->status_msg = "Delete record step 2 https request failed.";
            return false;
        }
        
        return true;
    }

    // Add a mail exchanger to the zone.
    // Note, if the owner is the root domain, then pass the domain name.
    // If the owner is a subdomain (must be an A record), only pass the sub.
    // For example, these are both correct:
    //   $sbdns->add_mail_exchanger("troywolf.com", 10, "mail.someserver.com");
    //   $sbdns->add_mail_exchanger("mail", 10, "mail.someserver.com");
    // This is NOT correct:
    //   $sbdns->add_mail_exchanger("mail.troywolf.com", 10, "mail.someserver.com");
    // Preference parameter is optional--will default to 10.
    function add_mail_exchanger($owner, $exchanger, $preference=10)
    {
        if (!$this->domain) {
            $this->status_msg = "Add mail exchanger failed because domain is not set.";
            return false;
        }

        $owner = strtolower($owner);
        $exchanger = strtolower($exchanger);
        
        // Make sure $owner is one of the A records for this domain.
        if (!$this->get_zone_records()) {
            $this->status_msg = "Add mail exchanger failed because get_records() failed.";
            return false;
        }
        $OK = false;
        foreach($this->records['A'] as $record) {
            if ((in_array($owner, $record))
            || (in_array($owner.".", $record))) {
                $OK = true;
                break;
            }
        }
        if (!$OK) {
            $this->status_msg = "Add mail exchanger failed because owner must be"
                ." an existing A record.";
            return false;
        }
        
        // Make sure $preference is between 10 and 100.
        if ((!ereg("^[0-9]{2,3}$", $preference))
        || ($preference < 10)
        || ($preference > 100)) {
            $this->status_msg = "Add mail exchanger failed because of invalid preference. 10 - 100";
            return false;
        }
        
        // Make sure $exchanger is not empty or an IP address.
        if (!ereg("[a-z]", $exchanger)) {
            $this->status_msg = "Add mail exchanger failed because of invalid exchanger.";
            return false;
        }

        // Step 1.
        usleep(500000 * $this->delay_factor);
        $this->http->clean();
        $this->url = "https://secure.serverbeach.com/mysb/dns/wizard_mx_host.php";
        $this->http->headers['Referer'] = "https://secure.serverbeach.com/mysb/dns/record_list.php";
        $this->http->headers['Cookie'] = $this->phpsessid;
        if (!$this->http->fetch($this->url)) {
            $this->status_msg = "Add mail exchanger step 1 https request failed.";
            return false;
        }

        // Step 2.
        usleep(500000 * $this->delay_factor);
        $this->http->clean();
        $this->url = "https://secure.serverbeach.com/mysb/dns/wizard_mx_pref.php";
        $this->http->headers['Referer'] = "https://secure.serverbeach.com/mysb/dns/wizard_mx_host.php";
        $this->http->headers['Cookie'] = $this->phpsessid;
        $this->http->postvars['info[new_domain]'] = $owner;
        $this->http->postvars['info[preference]'] = $preference;
        if (!$this->http->fetch($this->url)) {
            $this->status_msg = "Add mail exchanger step 2 https request failed.";
            return false;
        }

        // Step 3.
        usleep(500000 * $this->delay_factor);
        $this->http->clean();
        $this->url = "https://secure.serverbeach.com/mysb/dns/wizard_mx_processor.php";
        $this->http->headers['Referer'] = "https://secure.serverbeach.com/mysb/dns/wizard_mx_exchange.php";
        $this->http->headers['Cookie'] = $this->phpsessid;
        $this->http->postvars['info[new_exchange_dname]'] = $exchanger;
        $this->http->postvars['confirmed'] = "true";
        if (!$this->http->fetch($this->url)) {
            $this->status_msg = "Add mail exchanger step 4 https request failed.";
            return false;
        }

        return true;
    }

    // Change an existing mail exchanger (mx) record.
    // If you want to change the owner, then don't use this method. Instead,
    // delete the one you don't want and add the one you do want.
    function update_mail_exchanger($owner, $exchanger, $preference=10)
    {
        if (!$this->domain) {
            $this->status_msg = "Update mail exchanger failed because domain is not set.";
            return false;
        }

        $owner = trim(strtolower($owner));
        $exchanger = trim(strtolower($exchanger));

        if (!$this->records) {
            if (!$this->get_record_ids()) {
                $this->status_msg = "Delete mail exchanger because get_record_ids failed.";
                return false;
            }
        }
        
        // Make sure $owner is one of the MX records for this domain, and get the ID.
        if (!$this->get_zone_records()) {
            $this->status_msg = "Update mail exchanger failed because get_records() failed.";
            return false;
        }
        $OK = false;
        foreach($this->records['MX'] as $record) {
            if (($record['name'] == $owner)
            || ($record['name'] == ($owner."."))) {
                $id = $record['id'];
                $OK = true;
                break;
            }
        }
        if (!$OK) {
            $this->status_msg = "Update mail exchanger failed because '".$owner."' must be"
                ." an existing MX record.";
            return false;
        }
        
        // Make sure $preference is between 10 and 100.
        if ((!ereg("^[0-9]{2,3}$", $preference))
        || ($preference < 10)
        || ($preference > 100)) {
            $this->status_msg = "Update mail exchanger failed because of invalid preference. 10 - 100";
            return false;
        }
        
        // Make sure $exchanger is not empty or an IP address.
        if (!ereg("[a-z]", $exchanger)) {
            $this->status_msg = "Update mail exchanger failed because of invalid exchanger.";
            return false;
        }

        // Step 1. Set the record id to modify.
        usleep(500000 * $this->delay_factor);
        $this->http->clean();
        $this->url = "https://secure.serverbeach.com/mysb/dns/record_list_processor.php?type=mx&id=".$id."&action=edit_mx";
        $this->http->headers['Referer'] = "https://secure.serverbeach.com/mysb/dns/record_list.php";
        $this->http->headers['Cookie'] = $this->phpsessid;
        if (!$this->http->fetch($this->url)) {
            $this->status_msg = "Update mail exchanger step 1 https request failed.";
            return false;
        }
        
        // Step 2. Step 1 returns a redirect to this step -- does not work
        // without this step.
        usleep(500000 * $this->delay_factor);
        $this->http->clean();
        $this->url = "https://secure.serverbeach.com/mysb/dns/wizard_edmx_data.php";
        $this->http->headers['Referer'] = "https://secure.serverbeach.com/mysb/dns/record_list.php";
        $this->http->headers['Cookie'] = $this->phpsessid;
        if (!$this->http->fetch($this->url)) {
            $this->status_msg = "Update mail exchanger step 2 https request failed.";
            return false;
        }

        // Step 3.
        usleep(500000 * $this->delay_factor);
        $this->http->clean();
        $this->url = "https://secure.serverbeach.com/mysb/dns/wizard_edmx_processor.php";
        $this->http->headers['Referer'] = "https://secure.serverbeach.com/mysb/dns/record_list.php";
        $this->http->headers['Cookie'] = $this->phpsessid;
        $this->http->postvars['info[new_owner]'] = $owner;
        $this->http->postvars['info[new_preference]'] = $preference;
        $this->http->postvars['info[new_exchange_dname]'] = $exchanger;
        $this->http->postvars['confirmed'] = "true";
        if (!$this->http->fetch($this->url)) {
            $this->status_msg = "Update mail exchanger step 3 https request failed.";
            return false;
        }
        
        return true;
    }


    // Delete a mail exchanger from the domain.
    // NOTE: If the owner is the root A record, then pass the whole domain name.
    // If the owner is a sub, then pass only the sub name. That is, do not
    // append the domain name to the sub.
    // Examples:
    //   $sbdns->delete_mail_exchanger("troywolf.com");
    //   $sbdns->delete_mail_exchanger("mail");
    function delete_mail_exchanger($owner)
    {
        if (!$this->domain) {
            $this->status_msg = "Delete mail exchanger failed because domain is not set.";
            return false;
        }

        $owner = strtolower($owner);

        if (!$this->records) {
            if (!$this->get_record_ids()) {
                $this->status_msg = "Delete mail exchanger because get_record_ids failed.";
                return false;
            }
        }

        // Find ID.
        $id = false;
        foreach($this->records['MX'] as $record) {
            if (($record['name'] == $owner)
            || ($record['name'] == ($owner."."))) {
                $id = $record['id'];
                break;
            }
        }
        if (!$id) {
            $this->status_msg = "Delete mail exchanger failed because '".$owner."' not found in your zone's MX records.";
            return false;
        }
        
        // Step 1.
        $this->http->clean();
        usleep(500000 * $this->delay_factor);
        $this->url = "https://secure.serverbeach.com/mysb/dns/record_list_processor.php?type=mx&id=".$id."&action=del_mx";
        $this->http->headers['Referer'] = "https://secure.serverbeach.com/mysb/dns/record_list.php";
        $this->http->headers['Cookie'] = $this->phpsessid;
        if (!$this->http->fetch($this->url)) {
            $this->status_msg = "Delete mail exchanger step 1 https request failed.";
            return false;
        }

        // Step 2.
        $this->http->clean();
        usleep(500000 * $this->delay_factor);
        $this->url = "https://secure.serverbeach.com/mysb/dns/wizard_delmx_processor.php";
        $this->http->headers['Referer'] = "https://secure.serverbeach.com/mysb/dns/record_list.php";
        $this->http->headers['Cookie'] = $this->phpsessid;
        $this->http->postvars['confirmed'] = "true";
        if (!$this->http->fetch($this->url)) {
            $this->status_msg = "Delete mail exchanger step 2 https request failed.";
            return false;
        }
        
        return true;
    }


    // Retreive the zone file text. Also used by get_zone_records().
    function get_zone_file()
    {
        if (!$this->domain) {
            $this->status_msg = "Get zone file failed because domain is not set.";
            return false;
        }

        $this->http->clean();
        usleep(500000 * $this->delay_factor);
        $this->url = "https://secure.serverbeach.com/mysb/dns/zone_file.php";
        $this->http->headers['Referer'] = "https://secure.serverbeach.com/mysb/dns/index.php";
        $this->http->headers['Cookie'] = $this->phpsessid;
        if (!$this->http->fetch($this->url)) {
            $this->status_msg = "Get zone file https request failed.";
            return false;
        }

        $posA = strpos($this->http->body, '$ttl');
        $posB = strpos($this->http->body, '</', $posA);
        if (($posA === false) || ($posA > $posB)) {
            $this->status_msg = "Get zone file failed to find zone data in returned body.";
            return false;
        }
        $this->zone = substr($this->http->body, $posA, $posB - $posA);
        return $this->zone;
    }
    
    // Parse the zone file to find all the NS, A, CNAME, and MX records.
    // Creates a $this->records array. You should print out the array to
    // see what it looks like and how to work with it. Used by get_record_ids().
    function get_zone_records()
    {
        if (!$this->zone) {
            if (!$this->get_zone_file()) {
                $this->status_msg = "Get zone records failed because get_zone_file failed.";
                return false;
            }
        }
        $lines = split("\n",$this->zone);
        #echo "<pre>"; print_r($lines); echo "</pre>";
        foreach($lines as $idx=>$line) {
            if (($idx > 2) && (strpos($line, "IN"))) {
                while(strpos($line, "  ") !== false) {
                    $line = str_replace("  ", " ", $line);
                }
                $parts = split(" ", $line);
                if ($parts[2] == "MX") {
                    $this->records[trim($parts[2])][] = array("id"=>null, "name"=>trim($parts[0]),"target"=>trim($parts[4]), "preference"=>trim($parts[3]));
                } else {
                    $this->records[trim($parts[2])][] = array("id"=>null, "name"=>trim($parts[0]), "target"=>trim($parts[3]));
                }
            }
        }
       #echo "<pre>"; print_r($this->records); echo "</pre>";
       return true;
    }
    
    // The ability of this class to update and delete A,CNAME, and MX records
    // depends on this method in order to know the SB ID of the record.
    // This is the most likely method to break because screen-scraping is a
    // brittle activity that can be broken simply by SB changing the page layout.
    // If this method stops working for you, check for an updated class at
    // www.troywolf.com.
    function get_record_ids()
    {
        // We need to make sure set_domain() has been called.
        // We also need to have records, so the record check will indirectly
        // ensure that the domain has been set. However, since it could be a
        // common mistake to forget to set the domain first, go ahead and make
        // this check here.
        if (!$this->domain) {
            $this->status_msg = "Get record ids failed because domain is not set.";
            return false;
        }
        if (count($this->records) == 0) {
            if (!$this->get_zone_records()) {
                $this->status_msg = "Get zone record ids failed because get_zone_records failed.";
                return false;
            }
        }
        // Get the record list HTML so we can parse out the ids. This will be fun. ;)
        usleep(500000 * $this->delay_factor);
        $this->http->clean();
        $this->url = "https://secure.serverbeach.com/mysb/dns/record_list.php";
        $this->http->headers['Referer'] = "https://secure.serverbeach.com/mysb/dns/index.php";
        $this->http->headers['Cookie'] = $this->phpsessid;
        if (!$this->http->fetch($this->url)) {
            $this->status_msg = "Get record list ids https request failed.";
            return false;
        }
        // This will get the SB ids for the A and CNAME records.
        $scraped_table = http::table_into_array($this->http->body, "edit_sub", 1, "<a>");
        for($idx = 2; $idx < count($scraped_table); $idx++) {
            $links = $scraped_table[$idx][2];
            $posA = strpos($links, "?type=")+6;
            $posB = strpos($links, "&id", $posA);
            $rectype = strtoupper(substr($links, $posA, $posB-$posA));
            $posA = strpos($links, "&id=")+4;
            $posB = strpos($links, "&action", $posA);
            $id = substr($links, $posA, $posB-$posA);
            foreach($this->records[$rectype] as $key=>$record) {
                $x = trim($scraped_table[$idx][0]);
                if (($x == $record['name'].".".$this->domain)
                || ($x."." == $record['name']))  {
                    $this->records[$rectype][$key]['id'] = $id;
                    break;
                }
            }
        }

        // This will get the SB ids for the MX records.
        $scraped_table = http::table_into_array($this->http->body, "?type=mx", 1, "<a>");
        for($idx = 2; $idx < count($scraped_table); $idx++) {
            $links = $scraped_table[$idx][3];
            $posA = strpos($links, "&id=")+4;
            $posB = strpos($links, "&action", $posA);
            $id = substr($links, $posA, $posB-$posA);
            foreach($this->records['MX'] as $key=>$record) {
                $x = trim($scraped_table[$idx][0]);
                if (($x == $record['name'].".".$this->domain)
                || ($x."." == $record['name']))  {
                    $this->records['MX'][$key]['id'] = $id;
                    break;
                }
            }
        }

        return true;    
    }
   
    // Useful function for debugging. Add whatever you want to this.
    function dump()
    {
        echo "<hr /><h4>Status</h4>".$this->http->status;
        echo "<hr /><h4>HTTP Header returned</h4><pre>".$this->http->header."</pre>";
        echo "<hr /><h4>HTTP Body returned</h4>".$this->http->body;
        echo "<hr /><h4>http object log</h4>".$this->http->log;
    }
}

?>