Help How can i write to client via a packet?

[Hustman]

Can i create a new writeH somehow to be linked to a new or existed variable in client like below? For example make the weight variable dynamically changed from java
https://prnt.sc/e2gnUEgP_y0C

Edited September 11, 2022 by Hustman

[eMommy]

48 minutes ago, Hustman said:

Can i create a new writeH somehow to be linked to a new or existed variable in client like below? For example make the weight variable dynamically changed from java
https://prnt.sc/e2gnUEgP_y0C

no? you are limited to what your client is able to read. dont touch stuff like this if you dont know what it does lol because then you might not able to see any items normally

[Hustman]

5 minutes ago, eMommy said:

no? you are limited to what your client is able to read. dont touch stuff like this if you dont know what it does lol because then you might not able to see any items normally

It's a test server ofc nothing to be worried about, i just try to learn stuff about interface

[xdem]

you can do lots of things by playing with the bytes here. on my server i switched all writeD into writeHwriteH and with the proper interface rework u are able to send more variables from the server, the data structure is static u can't introduce new bytes tho

[Hustman]

5 minutes ago, xdem said:

you can do lots of things by playing with the bytes here. on my server i switched all writeD into writeHwriteH and with the proper interface rework u are able to send more variables from the server, the data structure is static u can't introduce new bytes tho

That's clever but how will i know which variable is written? I have to do tests?

[An4rchy]

You can certainly send new data in different ways to the client and read it properly too.

 

Off the top of my head, use a packet like TutorialShowHtml, it has got the packet opcode, an int (depending on your client, interlude doesn't have it) that's basically large or small window and a string which you can fill with your custom data. Make sure there is a unique identifier within your string of data to properly read it in unreal script (interface source).

 

Then, go to InterfaceViewerWnd.uc, under OnEvent() function there is a switch (Event_ID) statement. case EV_TutorialViewerWndShow : is what you're looking for, as this event id is called when you send said packet. Check if the string received begins or contains your identifier and if so, execute your code or store the variable for w/e usage you wish.

 

For example, I used this way to properly implement interlude-like fishing back in Classic client, as it was disabled.

 

-

 

Another way, as xdem proposed, is to use existing bytes for different data. For example, if you're sending an integer that you're sure is within the bounds of a short, you can replace the writeD() by 2 x writeH() as it will be the same bytes, but more info for you to send. Further modification in the interface source is required to make the extra data readable depending on which packet you're editing. I think there's a topic here in MxC where they used this way to add augmentation info in trade window.

Edited September 14, 2022 by An4rchy

[xdem]

8 minutes ago, An4rchy said:

You can certainly send new data in different ways to the client and read it properly too.

 

Off the top of my head, use a packet like TutorialShowHtml, it has got the packet opcode, an int (depending on your client, interlude doens't have it) that's basically large or small window and a string which you can fill with your custom data. Make sure there is a unique identifier within your string of data to properly read it in unreal script (interface source).

 

Then, go to InterfaceViewerWnd.uc, under OnEvent() function there is a switch (Event_ID) statement. case EV_TutorialViewerWndShow : is what you're looking for, as this event id is called when you send said packet. Check if the string received begins or contains your identifier and if so, execute your code or store the variable for w/e usage you wish.

 

For example, I used this way to properly implement interlude-like fishing back in Classic client, as it was disabled.

 

-

 

Another way, as xdem proposed, is to use existing bytes for different data. For example, if you're sending an integer that you're sure is within the bounds of a short, you can replace the writeD() by 2 x writeH() as it will be the same bytes, but more info for you to send. Further modification in the interface source is required to make the extra data readable depending on which packet you're editing. I think there's a topic here in MxC where they used this way to add augmentation info in trade window.

 

in his example data sent from html packet isn't useful since he wants to have dynamic values per item, I wouldn't stress my server or interface with thousands of values coming from html packets, these is job that engine.dll should handle internally. The only way he has to go is byte shifting existing values, getMana and getTime is a good start

[Hustman]

43 minutes ago, xdem said:

 

in his example data sent from html packet isn't useful since he wants to have dynamic values per item, I wouldn't stress my server or interface with thousands of values coming from html packets, these is job that engine.dll should handle internally. The only way he has to go is byte shifting existing values, getMana and getTime is a good start

So for example if i turn this:

 

packet.writeD(item.getTime());

into this: 

 

packet.writeH(100);
packet.writeH(100);

 

Do i still write on Item.CurrentDurability with both writeH?

[An4rchy]

If you want to edit item info regarding items in general (stats show for example tooltip window) then yeah html wouldn't be the best choice since thousands would be sent as you said. But you're making a custom window or something and the data is little, then html packet manipulation is a functioning and easy way to do it.

[BabayG]

first of all, u need to understand the basics Server( java or cpp) are using native functions to transfer( formed data , in your case lineage 2 packets), client also is using native functions to recv them( advice* u can hook those native functions, google it - github hooking win32 process , dll example , ) u need to do this because u dont have access to client source code, only to binary . Also u have to know what native functions exactly are used( their names) for example to init connection there is function called “wsastartup”, to send data (“send”) these functions are part of .dll that called ws32 or something alike, so u can see full list of the functions names . Last but not least,  to form the packet data, especially in client , exist custom functions ( not native) made by ncsoft programmers, u have to find them in ida32 , these functions called native functions ( names that u should allready know, as I mentioned them ) , u might have to understand what calling a function is, but maybe not, functionPacket1 -> FunctionNative1, functionPacket2 -> FunctionNative1. If u understand that u can fins them. And then u have to hook those functionPacket2, and add functionality that u need for your dynamic weight or whatever

[Hustman]

2 hours ago, xdem said:

you can do lots of things by playing with the bytes here. on my server i switched all writeD into writeHwriteH and with the proper interface rework u are able to send more variables from the server, the data structure is static u can't introduce new bytes tho

I think i get what you say, instead of sending 32 bits with D i can separate them to 16-16 with h and then get them from the variable that they are written with same way, by shifting them again.

[nixiasilfia]

I really appreciate the technical details you provided