User:Darien Caldwell/HTTP-DNS

Dynamic DNS service for HTTP-IN via Google App Engine:

Once it's installed you can start using it:

• http://yourappname.appspot.com/?type=add&name=[NAME]&url=[URL]

Adds a new service named [NAME] with the HTTP-IN url [URL]. The URL must be converted to a string using llEscapeURL() first.

if the URL is added, returns the response 'Added', or 'Found' if the service
already exists. 

• http://yourappname.appspot.com/?type=remove&name=[NAME]

Removes the given service named [NAME].

Returns 'Removed' if successful, or 'None' if the service wasn't found.

• http://yourappname.appspot.com/?type=update&name=[NAME]&url=[URL]

Updates the service named [NAME] with the HTTP-IN url [URL].

The URL must be converted to a string using llEscapeURL() first.
If the URL is updated the response 'Updated' is returned.
If the service doesn't exist, a new service is added and 'Added' is returned.

• http://yourappname.appspot.com/?type=retrieve&name=[NAME]

Retrieves the url of the given service named [NAME].

Returns the URL if the service is found, or 'None' if the service wasn't found.
the returned URL must be converted to a URL using llUnescapeURL()

• http://yourappname.appspot.com/?type=list

Lists the available services currently stored.

Returns a Comma seperated list of service names, ending with the word 'END'.

if no services are defined, 'Empty' is returned.

Using the DNS URL

Once a service has been entered, you can use the serivce name in the URL to do automatic redirection.

Example:

You establish a service named 'intro1'

The URL for the service is: http://sim3015.aditi.lindenlab.com:12046/cap/3ff4f3f2-ea08-76c1-cef6-a22b4a573a7c

By Navigating to http://yourappname.appspot.com/intro1 The page will be automatically redirected to the service URL:

http://sim3015.aditi.lindenlab.com:12046/cap/3ff4f3f2-ea08-76c1-cef6-a22b4a573a7c

If the service name used in the URL is invalid, 'None' is returned.

<lsl>

string url = ""; string service_name = "my_service"; key URL_KEY;

setup() {

   llReleaseURL(url);
   URL_KEY=llRequestURL();

}

default {

   state_entry()
   {
       llSetObjectName("HTTP Server");
       setup();
   }
   
   on_rez(integer n)
   {
       setup();
   }

   changed(integer c)
   {
       if (c & (CHANGED_REGION | CHANGED_REGION_START | CHANGED_TELEPORT) )
       {
           setup();
       }
   }

   //Response to our HTTPRequest
   http_response(key id, integer status, list meta, string body)
   {
       
       if (status == 415) // The remote server did reply to your request but the Content-Type of the reply (such as XML, JSON, Atom, RSS, PLS) 
                          // is not recognised by the LL server and so is not passed back to the script. 
                          // You can assume that 415 means the server heard your request and did reply. 
       {
           llInstantMessage(llGetOwner(),"Special Error Status 415 Encountered.");
           return;
       }
       else if (status == 499) // Besides the usual HTTP status codes, SL implements a special status code 499. 
                               // This code isn't generated by the remote web server but by SL's servers, it can indicate: 
                               // Request timeout (60 seconds)   --  SSL failure  --  A space was present in the url (escape your URL with llEscapeURL). 
       {
           llInstantMessage(llGetOwner(),"Special Error Status 499 Encountered.");
           return;
       }
       else if (status == 502)  // The proxy server received an invalid response from an upstream server. 
                                // This error occurs when you send an llHTTPRequest to an object in-world, and it does not reply with an llHTTPResponse. 
       {
           llInstantMessage(llGetOwner(),"Special Error Status 502 Encountered.");
           return;
       }
       
       if (body=="Updated") llOwnerSay("DNS updated with Server Address.");
       else  llOwnerSay("Response code:"+(string)status+" Body:"+body);  // Some other arbitrary response

   }

   http_request(key id, string method, string body)
   {
       if (id==URL_KEY)
       {
           if (method == URL_REQUEST_GRANTED)
           {
               url = body;
               llHTTPRequest("http://yourappname.appspot.com/?type=add&name=" + service_name + "&url=" + llEscapeURL(url),[],"");
           }
           else
           {
               url="";
               llOwnerSay("Error: HTTP-IN URL Request Denied.");
           }
       }
       else
       {
           // Some other Request
           llOwnerSay("Got:"+body);
           string pathInfoHeader = llGetHTTPHeader(id, "x-path-info");
           llOwnerSay("Path:"+pathInfoHeader);
           string query = llGetHTTPHeader(id, "x-query-string");
           llOwnerSay("Query:"+query);
       }
       
       // should always respond to prevent timeouts.
       llHTTPResponse(id,200,"ACK"); 
   }

} </lsl>