LSL Protocol/Restrained Love Relay/Reference Implementation

From Second Life Wiki
< LSL Protocol‎ | Restrained Love Relay
Revision as of 01:28, 30 August 2008 by Maike Short (talk | contribs) (Version 1.015)
Jump to navigation Jump to search
Restrained Love Relay

This particular example that anyone can distribute freely as open-source only (you are not allowed to sell this code) and including the header comments is just meant to give an idea of how a relay basically works. You can find the change history at Change History,


What it does

  • Implements the specification described hereabove.
  • Commented to facilitate reading and learning.
  • Tested and working with test objects and with real cages.


What it doesn't do

  • Error-checking.
  • Access lists.
  • Lock on the avatar.
  • Handle more than one object.
  • Reject some commands by nature.
  • And so much more that makes good scripts stand out in the crowd.


How to use it

  • Create a prim in which you put a script containing this code (don't forget to name it correctly by following the "RLVnnn" requirement).
  • Wear the prim, it says its current on/off status
  • Click on the prim to switch from "Off" to "On with permission" to "On without permission" and back to "Off"
  • Find an object that implements this specification and test.


Special thanks

  • Chorazin Allen for reviewing the code, giving ideas, coding and re-coding his own scripts to make sure everything works properly between the relay and the cage, and for not killing me every time I change my mind here and there on the spec.
  • Azoth Amat and Nano Siemens for helping to find a solution to the "force sit on login" problem
  • Gregor Mougin for discovering and fixing the not-pong reply on login.

Reference Implementation

Please add fixes, new features and stuff like that to Development & Contribution.

<lsl> //~ RestrainedLife Viewer Relay Script example code //~ By Marine Kelley, Maike Short, Felis Darwin //~ Thanks to Chorazin Allen, Azoth Amat, Gregor Mougin, Nano Siemens, Cerdita Piek

//~ This code is provided AS-IS, OPEN-SOURCE and holds NO WARRANTY of accuracy, //~ completeness or performance. It may only be distributed in its full source code, //~ this header and disclaimer and is not to be sold.

integer DEBUG = FALSE;

// make cheating (adding exceptions) a bit more difficult by not allowing // attachment to control the viewer as they are not subjected to land building // restrictions integer ALLOW_CONTROL_BY_ATTACHMENTS = FALSE;


// list of refused commands. Use [] to allow everything or // ["@detach", "@remoutfit"] to prevent striping for example list refusedForceCommands = [];

// --------------------------------------------------- // Constants // ---------------------------------------------------

integer RLVRS_PROTOCOL_VERSION = 1015; // version of the protocol, stated on the specification page string RLVRS_IMPL_VERSION = "MSM Restraints 1.015.a"; // version of the implementation for debugging

string PREFIX_RL_COMMAND = "@"; string PREFIX_METACOMMAND = "!";

integer RLVRS_CHANNEL = -1812221819; // RLVRS in numbers integer DIALOG_CHANNEL = -1812220409; // RLVDI in numbers integer STATUS_LINK_CHANNEL = -1373421300; integer RLV_LINK_CHANNEL = -1373421301; integer CMD_LINK_CHANNEL = -1373421302; integer DIALOG_LINK_CHANNEL = -1373421303; integer ASK_LINK_CHANNEL = -1373421304;

integer MAX_OBJECT_DISTANCE = 20; // 20m is llSay distance integer MAX_TIME_AUTOACCEPT_AFTER_FORCESIT = 60; // seconds

integer PERMISSION_DIALOG_TIMEOUT = 30; integer LOGIN_DELAY_WAIT_FOR_PONG = 10; integer LOGIN_DELAY_WAIT_FOR_FORCE_SIT = 60;

integer MODE_OFF = 0; integer MODE_ASK = 1; integer MODE_AUTO = 2;

list MODE_DESCRIPTIONS = ["RLV Relay is OFF", "RLV Relay is ON (permission needed)", "RLV Relay is ON (auto-accept)"];

string RVL_COMMAND_START = "@detach=n"; string RVL_COMMAND_END = "@detach=y";


// --------------------------------------------------- // Variables // ---------------------------------------------------

integer mode;

list restrictions; // restrictions currently applied (without the "=n" part) key source; // UUID of the object I'm commanded by, always equal to NULL_KEY if restrictions is empty, always set if not

string pendingName; // name of initiator of pending request (first request of a session in mode 1) key pendingId; // UUID of initiator of pending request (first request of a session in mode 1) string pendingMessage; // message of pending request integer pendingTime;

// used on login integer timerTickCounter; // count the number of time events on login (forceSit has to be delayed a bit) integer loginWaitingForPong; integer loginPendingForceSit;

key lastForceSitDestination; integer lastForceSitTime;

integer isNotEmbedded = TRUE;

// --------------------------------------------------- // Helper functions // ---------------------------------------------------


debug(string x) { 

   if (DEBUG)
   {
       llOwnerSay("DEBUG: " + x);
   }

}

// checks whether this object is an attachment of an avatar integer isAttachment(key id) { 

   vector objpos1 = llList2Vector(llGetObjectDetails(id, [OBJECT_POS]), 0);
   vector ownerpos = llList2Vector(llGetObjectDetails(llGetOwnerKey(id), [OBJECT_POS]), 0);
   vector objpos2 = llList2Vector(llGetObjectDetails(id, [OBJECT_POS]), 0);
   return (llVecMag(objpos1 - ownerpos) <= llVecMag(objpos1 - objpos2));

}


// --------------------------------------------------- // Low Level Communication // ---------------------------------------------------


// acknowledge or reject ack(string cmd_id, key id, string cmd, string ack) { 

   llSay(RLVRS_CHANNEL, cmd_id + "," + (string)id + "," + cmd + "," + ack);

}

// cmd begins with a '@' sendRLCmd(string cmd) { 

   if (cmd != "")
   {
       if (isNotEmbedded)
       {
           llOwnerSay(cmd);
       }
       llMessageLinked(LINK_SET, RLV_LINK_CHANNEL, cmd, source);
   }

}


// check that this command is for us and not someone else integer verifyWeAreTarget(string message) { 

   list tokens = llParseString2List(message, [","], []);
   if (llGetListLength(tokens) != 3) // this is not a normal command
   {
       return FALSE;
   }

   return (llList2String(tokens, 1) == llGetOwner()); // talking to me ?

}

// checks that the type of object (world object, attachment) is allowed integer verifySourceType(key id) { 

   if (ALLOW_CONTROL_BY_ATTACHMENTS)
   {
       return TRUE;
   }
   
   return !isAttachment(id);

}

// --------------------------------------------------- // Permission Handling // ---------------------------------------------------


// are we already under command by this object? integer isObjectKnow(key id) { 

   // are we already under command by this object?
   if (source == id)
   {
       return TRUE;
   }

   // are we not under command by any object but were we forced to sit on this object recently?
   if ((source == NULL_KEY) && (id == lastForceSitDestination))
   {
       debug("on last force sit target");
       if (lastForceSitTime + MAX_TIME_AUTOACCEPT_AFTER_FORCESIT > llGetUnixTime())
       {
           debug("and recent enough to auto accept");
           return TRUE;
       }
   }

   return FALSE;

}


// check whether the object is in llSay distance. // The specification requires llSay instead of llShout or llRegionSay // to be used to limit the range. But this has to be checked here again // because the objects are not trustworthy. integer isObjectNear(key id) { 

   vector myPosition = llGetRootPosition();
   list temp = llGetObjectDetails(id, ([OBJECT_POS]));
   vector objPostition = llList2Vector(temp,0);
   float distance = llVecDist(objPostition, myPosition);
   return distance <= MAX_OBJECT_DISTANCE;

}

// do a basic check on the identity of the object trying to issue a command integer isObjectIdentityTrustworthy(key id) { 

   key parcel_owner=llList2Key (llGetParcelDetails (llGetPos (), [PARCEL_DETAILS_OWNER]), 0);
   key parcel_group=llList2Key (llGetParcelDetails (llGetPos (), [PARCEL_DETAILS_GROUP]), 0);
   key object_owner=llGetOwnerKey(id);
   key object_group=llList2Key (llGetObjectDetails (id, [OBJECT_GROUP]), 0);

   debug("owner= " + (string) parcel_owner + " / " + (string) object_owner);
   debug("group= " + (string) parcel_group + " / " + (string) object_group);

   if (object_owner==llGetOwner ()        // IF I am the owner of the object
     || object_owner==parcel_owner        // OR its owner is the same as the parcel I'm on
     || object_group==parcel_group        // OR its group is the same as the parcel I'm on
   )
   {
       return TRUE;
   }
   return FALSE;

}


// Is this a simple request for information or a meta command like !release? integer isSimpleRequest(list list_of_commands) { 

   integer len = llGetListLength(list_of_commands);
   integer i;

   // now check every single atomic command
   for (i=0; i < len; ++i)
   {
       string command = llList2String(list_of_commands, i);
       if (!isSimpleAtomicCommand(command))
       {
          return FALSE;
       }
   }

   // all atomic commands passed the test
   return TRUE;

}

// is this a simple atomar command // (a command which only queries some information or releases restrictions) // (e. g.: cmd ends with "=" and a number (@version, @getoutfit, @getattach) or is a !-meta-command) integer isSimpleAtomicCommand(string cmd) { 

   // check right hand side of the "=" - sign
   integer index = llSubStringIndex (cmd, "=");
   if (index > -1) // there is a "=" 
   {
       // check for a number after the "="
       string param = llGetSubString (cmd, index + 1, -1);
       if ((integer)param!=0 || param=="0") // is it an integer (channel number)?
       {
           return TRUE;
       }

       // removing restriction
       if ((param == "y") || (param == "rem"))
       {
           return TRUE;
       }
   }

   // check for a leading ! (meta command)
   if (llSubStringIndex(cmd, PREFIX_METACOMMAND) == 0)
   {
       return TRUE;
   }

   // check for @clear
   // Note: @clear MUST NOT be used because the restrictions will be reapplied on next login
   // (but we need this check here because "!release|@clear" is a BROKEN attempt to work around
   // a bug in the first relay implementation. You should refuse to use relay versions < 1013
   // instead.)
   if (cmd == "@clear")
   {
       return TRUE;
   }
 
   // this one is not "simple".
   return FALSE;

}

// If we already have commands from this object pending // because of a permission request dialog, just add the // new commands at the end. // Note: We use a timeout here because the player may // have "ignored" the dialog. integer tryToGluePendingCommands(key id, string commands) { 

   if (llStringLength(pendingMessage) > 4000)
   {
       llSay(0, llKey2Name(id) + " is flooding commands. Releasing restrictions.");
       releaseRestrictions();
       return TRUE;
   }
   if ((pendingId == id) && (pendingTime + PERMISSION_DIALOG_TIMEOUT > llGetUnixTime()))
   {
       debug("Gluing " + (string) pendingMessage + " with " + commands);
       pendingMessage = pendingMessage + "|" + commands;
       return TRUE;
   }
   return FALSE;

}


// accept !release even if out of range handleCommandsWhichAreAcceptedOutOfRange(key id, string message) { 

   if (id != source)
   {
       return;
   }

   list tokens = llParseString2List (message, [","], []);
   if (llGetListLength (tokens) < 3)
   {
       return;
   }
   string commands = llList2String(tokens, 2);
   list list_of_commands = llParseString2List(commands, ["|"], []);
   if (llListFindList(list_of_commands, ["!release"]) > -1)
   {
       debug("accepted !release although it was out of range");
       releaseRestrictions();
   }

}


// verifies the permission. This includes mode // (off, permission, auto) of the relay and the // identity of the object (owned by parcel people). integer verifyPermission(key id, string name, string message) { 

   // is it switched off?
   if (mode == MODE_OFF)
   {
       return FALSE;
   }

   list tokens = llParseString2List (message, [","], []);
   if (llGetListLength (tokens) < 3)
   {
       return FALSE;
   }
   string commands = llList2String(tokens, 2);
   list list_of_commands = llParseString2List(commands, ["|"], []);

   // if we are already having a pending permission-dialog request for THIS object,
   // just add the new commands at the end of the pending command list.
   if (tryToGluePendingCommands(id, commands))
   {
       return FALSE;
   }

   // accept harmless commands silently
   if (isSimpleRequest(list_of_commands))
   {
       return TRUE;
   }

   // check whether this object belongs here
   integer trustworthy = isObjectIdentityTrustworthy(id);
   string warning = "";
   if (!trustworthy)
   {
       warning = "\n\nWARNING: This object is not owned by the people owning this parcel. Unless you know the owner, you should deny this request.";
   }

   // ask in permission-request-mode and/OR in case the object identity is suspisous.
   if (mode == MODE_ASK || !trustworthy)
   {
       pendingId=id;
       pendingName=name;
       pendingMessage = message;
       pendingTime = llGetUnixTime();
       if (llKey2Name(llGetOwnerKey(id)) != "")
       {
           name += " (owned by " + llKey2Name(llGetOwnerKey(id)) + ")";
       }
       
       string text = name + " would like control your viewer." + warning + ".\n\nDo you accept ?";
       debug("Asking for permission isNotEmbedded=" + (string) isNotEmbedded);
       if (isNotEmbedded)
       {
           llDialog (llGetOwner(), text, ["Yes", "No"], DIALOG_CHANNEL);
       }
       llMessageLinked(LINK_SET, ASK_LINK_CHANNEL, text, id);
       debug("Asking for permission");
       return FALSE;
   }
   return TRUE;

}


// --------------------------------------------------- // Executing of commands // ---------------------------------------------------

// execute a non-parsed message // this command could be denied here for policy reasons, (if it were implemenetd) // but this time there will be an acknowledgement execute(string name, key id, string message) { 

   list tokens = llParseString2List(message, [","], []);
   string cmd_id = llList2String(tokens, 0); // CheckAttach
   list list_of_commands = llParseString2List(llList2String(tokens, 2), ["|"], []);

   integer len = llGetListLength (list_of_commands);
   integer i;
   string command;
   string prefix;
   for (i=0; i<len; ++i) // execute every command one by one
   {
       // a command is a RL command if it starts with '@' or a metacommand if it starts with '!'
       command = llList2String(list_of_commands, i);
       prefix = llGetSubString(command, 0, 0);

       if (prefix == PREFIX_RL_COMMAND) // this is a RLV command
       {
           executeRLVCommand(cmd_id, id, command);
       }
       else if (prefix == PREFIX_METACOMMAND) // this is a metacommand, aimed at the relay itself
       {
           executeMetaCommand(cmd_id, id, command);
       }
   }

}

// executes a command for the restrained life viewer // with some additinal magic like book keeping executeRLVCommand(string cmd_id, string id, string command) { 

   command = llToLower(command);
   // we need to know whether whether is a rule or a simple command
   list tokens = llParseString2List(command, ["="], []);
   string behav = llList2String(tokens, 0); // @getattach:skull
   string param = llList2String(tokens, 1); // 2222
   integer ind = llListFindList(restrictions, [behav]);

   tokens = llParseString2List(behav, [":"], []); // @sit:<uuid>
   string behavName = llList2String (tokens, 0);  // @sit
   string option = llList2String (tokens, 1);     // <uuid>
   
   debug("executeRLVCommand: behav=!" + behav + "! param=!" + param + "!");

   if (param=="n" || param=="add") // add to restrictions
   {
       if (ind < 0)
       {
           if (llGetListLength(restrictions) == 0)
           {
               sendRLCmd(RVL_COMMAND_START);
               llMessageLinked(LINK_SET, STATUS_LINK_CHANNEL, "start", id);
           } 
           restrictions += [behav];
       }
       source = id; // we know that source is either NULL_KEY or id already
   }
   else if (param == "y" || param == "rem") // remove from restrictions
   {
       if (ind > -1) 
       {
           restrictions = llDeleteSubList (restrictions, ind, ind);
       }
       if (llGetListLength(restrictions) == 0)
       {
           source = NULL_KEY;
           sendRLCmd(RVL_COMMAND_END);
       }
       removeFromPendingList(behav);
   }
   else if (param == "force")
   {
       if (llListFindList(refusedForceCommands, [behavName]) >= 0)
       {
           debug("rejected force-command: behav=!" + behav + "! behavName=!" + behavName + "!");
           ack(cmd_id, id, command, "ko");
           return;
       }
   }

   workaroundForAtClear(command);
   rememberForceSit(behavName, option, param);
   sendRLCmd(command); // execute command
   ack(cmd_id, id, command, "ok"); // acknowledge

}

// check for @clear // Note: @clear MUST NOT be used because the restrictions will be reapplied on next login // (but we need this check here because "!release|@clear" is a BROKEN attempt to work around // a bug in the first relay implementation. You should refuse to use relay versions < 1013 // instead.) workaroundForAtClear(string command) { 

   if (command == "@clear")
   {
       releaseRestrictions();
   }

}

// remembers the time and object if this command is a force sit rememberForceSit(string behavName, string option, string param) { 

   // clear lastForceSitDestination in case we are now prevented from standing up and
   // the force sit was long ago. Note: restrictions is checked to prevent the
   // clearance in case @unsit is just send again on login
   if (behavName == "@unsit")
   {
       if (llListFindList(restrictions, ["@unsit"]) < 0)
       {
           if (lastForceSitTime + MAX_TIME_AUTOACCEPT_AFTER_FORCESIT < llGetUnixTime())
           {
               debug("clearing lastForceSitDestination");
               lastForceSitDestination = NULL_KEY;
           }
       }
   }
   
   if (param != "force")
   {
       return;
   }

   debug("'force'-command:" + behavName + "/" + option);
   if (behavName != "@sit")
   {
       return;
   }
   lastForceSitDestination = (key) option;
   lastForceSitTime = llGetUnixTime();
   debug("remembered force sit");

}

// executes a meta command which is handled by the relay itself executeMetaCommand(string cmd_id, string id, string command) { 

   if (command == PREFIX_METACOMMAND + "version") // checking relay protocol version
   {
       ack(cmd_id, id, command, (string) RLVRS_PROTOCOL_VERSION);
   }
   else if (command == PREFIX_METACOMMAND + "implversion") // checking relay version
   {
       ack(cmd_id, id, command, RLVRS_IMPL_VERSION);
   }
   else if (command == PREFIX_METACOMMAND + "release") // release all the restrictions (end session)
   {
       releaseRestrictions();
       ack(cmd_id, id, command, "ok");
   }
   else if (command == PREFIX_METACOMMAND + "pong")
   {
       loginWaitingForPong = FALSE;
   }

}

// removes a restriction from the list of pending commands removeFromPendingList(string behav) { 

   string search = behav + "=";

   // don't do the expensive parsing (string operations are very slow in pre- 
   // mono LSL) in case we can detect fast that this one is not in the list.
   if (llSubStringIndex(pendingMessage, search) < 0)
   {
       return;
   }

   list tokens = llParseString2List(pendingMessage, [","], []);
   list commands = llParseString2List(llList2String(tokens, 2), ["|"], []);
   integer modified = FALSE;

   integer len = llGetListLength(commands);
   integer i;
   for (i = len - 1; i >= 0; i--)
   {
       string cmd = llList2String(commands, i);
       if (llSubStringIndex(cmd, search) == 0)
       {
           if (llSubStringIndex(cmd, "=n") > -1 || llSubStringIndex(cmd, "=add") > -1)
           {
               commands = llDeleteSubList(commands, i, i);
               modified = TRUE;
           } 
       }
   }

   if (modified)
   {
       if (llGetListLength(commands) > 0)
       {
           pendingMessage = llList2String(tokens, 0) + "," + llList2String(tokens, 1) + "," + llDumpList2String(commands, "|");
       }
       else
       {
           clearPendingMessages();
       }
   }

}


// lift all the restrictions (called by !release and by turning the relay off) releaseRestrictions() { 

   source = NULL_KEY;
   integer i;
   integer len = llGetListLength (restrictions);
   for (i = 0; i < len; ++i)
   {
       sendRLCmd(llList2String (restrictions, i) + "=y");
   }
   sendRLCmd(RVL_COMMAND_END);
   lastForceSitDestination = NULL_KEY;
   restrictions = [];
   loginPendingForceSit = FALSE;
   clearPendingMessages();
   llMessageLinked(LINK_SET, STATUS_LINK_CHANNEL, "release", NULL_KEY);

}


// deletes the list of pending messsages clearPendingMessages() { 

   // clear pending request
   pendingName = "";
   pendingId = NULL_KEY;
   pendingMessage = "";
   pendingTime = 0;

}


// processes a message send on the relay channel processRelayMessage(string name, key id, string message) { 

   if (mode== MODE_OFF)
   {
       debug("deactivated - ignoring commands");
       return; // mode is 0 (off) => reject
   }

   debug("LISTEN: " + message);

   if (!verifyWeAreTarget(message))
   {
      return;
   }

   if (!verifySourceType(id))
   {
       return;
   }

   debug("Got message (active world object " + (string) source + "): name=" + name+ " id=" + (string) id + " message=" + message);

   if (source)
   {
       if (source != id)
       {
           if (isObjectNear(source))
           {
               debug("already used by another object => reject");
               return;
           }
           else
           {
               debug("already used by another object, which is out of range");
               releaseRestrictions();
           }
       }
   }

   if (!isObjectNear(id)) 
   {
       handleCommandsWhichAreAcceptedOutOfRange(id, message);
       return;
   }

   if (!isObjectKnow(id))
   {
       debug("asking for permission because source is NULL_KEY");
       if (!verifyPermission(id, name, message))
       {
           return;
       }
   }

   debug("Executing: " + (string) source);
   execute(name, id, message);

}

// --------------------------------------------------- // mode and dialog handling // ---------------------------------------------------


// shows current mode as string showModeDescription() { 

   if (isNotEmbedded)
   {
       llOwnerSay(llList2String(MODE_DESCRIPTIONS, mode));
   }
   llMessageLinked(LINK_SET, STATUS_LINK_CHANNEL, "show_mode", (key) ((string) mode));

}


// process the Yes/No buttons of the permission dialog processDialogResponse(key id, string message) { 

   if (pendingId)
   {
       if (message == "Yes") // pending request authorized => process it
       {
           execute(pendingName, pendingId, pendingMessage);
       }
       clearPendingMessages();
   }

}


// --------------------------------------------------- // initialisation and login handling // ---------------------------------------------------

init() { 

   sendRLCmd("@clear");
   llOwnerSay("Waiting for plugins to initialize...");
   llSleep(5);

   mode = MODE_ASK;

   llListen(RLVRS_CHANNEL, "", "", "");
   llListen(DIALOG_CHANNEL, "", llGetOwner(), "");

   if (llGetFreeMemory() < 10000)
   {
       llSay(0, llKey2Name(llGetOwner()) + ", your relay is having very little free script memory and is likly to crash during use. Please verify that it was compiled using Mono.");
   }
   llMessageLinked(LINK_SET, STATUS_LINK_CHANNEL, "init", NULL_KEY);

   llOwnerSay("Initialized and ready");
   showModeDescription();
   debug("Free Memory: " + (string) llGetFreeMemory());

}


// sends the known restrictions (again) to the RL-viewer // (call this functions on login) reinforceKnownRestrictions() { 

   integer i;
   integer len = llGetListLength(restrictions);
   string restr;
   debug("source=" + (string) source);
   if (len > 0)
   {
       sendRLCmd(RVL_COMMAND_START);
   }
   for (i=0; i < len; ++i)
   {
       restr = llList2String(restrictions, i);
       debug("restr=" + restr);
       sendRLCmd(restr + "=n");
       if (restr == "@unsit")
       {
           loginPendingForceSit = TRUE;
       }
   }

}

// send a ping request and start a timer pingWorldObjectIfUnderRestrictions() { 

   loginWaitingForPong = FALSE;
   if (source)
   {
       ack("ping", source, "ping", "ping");
       timerTickCounter = 0;
       llSetTimerEvent(1.0);
       loginWaitingForPong = TRUE;
   }

}

sendForceSitDuringLogin() { 

   key sitTarget = source;
   if (lastForceSitDestination)
   {
       sitTarget = lastForceSitDestination;
   }
   debug("Force sit during login on " + (string) sitTarget + " (source=" + (string) source + ", lastForceSitDestination=" + (string) lastForceSitDestination + ")");
   sendRLCmd ("@sit:" + (string) sitTarget + "=force");

}


// processes a timer event processTimer() { 

   timerTickCounter++;
   debug("timer (" + (string) timerTickCounter + "): waiting for pong: " + (string) loginWaitingForPong + " pendingForceSit: " + (string) loginPendingForceSit);
   if (loginWaitingForPong && (timerTickCounter >= LOGIN_DELAY_WAIT_FOR_PONG))
   {
       llWhisper(0, "Lucky Day: " + llKey2Name(llGetOwner()) + " is freed because the device is not available.");
       loginWaitingForPong = FALSE;
       loginPendingForceSit = FALSE;
       releaseRestrictions();
   }

   if (loginPendingForceSit)
   {
       integer agentInfo = llGetAgentInfo(llGetOwner());
       if (agentInfo & AGENT_SITTING)
       {
           loginPendingForceSit = FALSE;
           debug("is sitting now");
       }
       else if (timerTickCounter == LOGIN_DELAY_WAIT_FOR_FORCE_SIT)
       {
           llWhisper(0, "Lucky Day: " + llKey2Name(llGetOwner()) + " is freed because sitting down again was not possible.");
           loginPendingForceSit = FALSE;
           releaseRestrictions();
       }
       else
       {
           sendForceSitDuringLogin();
       }
   }

   if (!loginPendingForceSit && !loginWaitingForPong)
   {
       llSetTimerEvent(0.0);
   }

}

processLinkMessage(key id, string message) { 

   if (message == "safeword")
   {
       llSay(0, llKey2Name(llGetOwner()) + " said the safeword. Freeing and deactivating relay.");
       releaseRestrictions();
       mode = MODE_OFF;
       showModeDescription();
       return;
   }

   if (message == "unlock")
   {
       if (id)
       {
           llSay(0, llKey2Name(id) + " freed " + llKey2Name(llGetOwner()) + " by unlocking the relay.");
       }
       releaseRestrictions();
       return;
   }

    if (message == "mode")
    {
        if (source)
       {
           llOwnerSay("Sorry, you cannot change the relay mode while it is active.");
           return;
       }
        mode = ((integer) ((string) id)) % 3;    
       showModeDescription();
       return;
    }

   if (message == "refusedForceCommands")
   {
       refusedForceCommands = llParseString2List((string) id, [","], []);
       return;
   }

   if (message == "embedded")
   {
       isNotEmbedded = FALSE;
       return;
   }

}


default { 

   state_entry()
   {
       init();
   }

   on_rez(integer start_param)
   {
       // relogging, we must refresh the viewer and ping the object if any
       // if mode is not OFF, fire all the stored restrictions
       if (mode)
       {
           reinforceKnownRestrictions();
           pingWorldObjectIfUnderRestrictions();
       }
       // remind the current mode to the user
       showModeDescription();
   }

   timer()
   {
       processTimer();
   }

   listen(integer channel, string name, key id, string message)
   {
       if (channel==RLVRS_CHANNEL)
       {
           processRelayMessage(name, id, message);
       }
       else if (channel==DIALOG_CHANNEL)
       {
           processDialogResponse(id, message);
       }
   }
   
   link_message(integer sender, integer channel, string message, key id)
   {
       if (channel == CMD_LINK_CHANNEL)
       {
           processLinkMessage(id, message);
       }
       else if (channel == DIALOG_LINK_CHANNEL)
       {
           processDialogResponse(id, message);
       }
   }

   touch_start(integer num_detected)
   {
       if (!isNotEmbedded)
       {
           return;
       }

       // touched by user => cycle through OFF/ON_PERMISSION/ON_ALWAYS modes
       key toucher = llDetectedKey(0);
       if (toucher != llGetOwner())
       {
           return;
       }

       if (source)
       {
           llOwnerSay("Sorry, you cannot change the relay mode while it is active.");
           return;
       }
       mode = (mode + 1) % 3;
       if (mode == MODE_OFF) {
           releaseRestrictions();
       }
       showModeDescription();
   }

   changed(integer change)
   {
       if (change & (CHANGED_OWNER | CHANGED_INVENTORY | CHANGED_ALLOWED_DROP)) 
       {
            llResetScript();
       }
   }

}

</lsl>

Retrieved from "https://wiki.secondlife.com/w/index.php?title=LSL_Protocol/Restrained_Love_Relay/Reference_Implementation&oldid=88946"