Is there MaNGOS Protocol Documentation?

[echeese]

Hi there, I am interested in learning about the protocol used in MaNGOS to make some client software. Do you know where I can learn about how the protocol functions?

[hunuza]

I don't think that there is something like a documentation to this. It would anyway probably be pretty fast outdated.

So the only resource to get information on the protocol is the MaNGOS source code.

[FragFrog]

I have been doing some research into it myself (from a mostly academic point of view of trying to make a 'server' people could connect to in JAVA), but even most of the source is mysterious about it.

Good starting points in the source I found so far:

1. game -> Server -> Opcodes.cpp / Opcodes.h lists all expected codes send by clients.

2. WorldSocket.cpp, WorldSocket::HandleAuthSession in particular seems to handle the connecting of new clients to mangos.

3. WorldSession seems to handle booting of players and some communication from and to them.

Don't expect much documentation there - a few lines of hints randomly placed is about it for most functions / classes. Some methods are entirely undocumented while other functions are quite well written with pleny of comments throughout, I am guessing the result of an open-source development model.

If you do ever find some real protocol documentation, let me know

[VladimirMangos]

In stricted meaning protocol as set of packets with structure is well described by source code:

For example client->server packet:

    /*0x10E*/ { "CMSG_SPLIT_ITEM",                              STATUS_LOGGEDIN, &WorldSession::HandleSplitItemOpcode           },

Look in WorldSession::HandleSplitItemOpcode:

void WorldSession::HandleSplitItemOpcode( WorldPacket & recv_data )
{
   //sLog.outDebug("WORLD: CMSG_SPLIT_ITEM");
   uint8 srcbag, srcslot, dstbag, dstslot;
   uint32 count;

   recv_data >> srcbag >> srcslot >> dstbag >> dstslot >> count;

So recieved packet include 5 fields and have (1+1+1+1+4 = 8 bytes size.

Meaning of fields described by its names and later code that use its.

In same function we see function calles for item operation errors reporting to client:

        _player->SendEquipError( EQUIP_ERR_ITEM_NOT_FOUND, NULL, NULL );

    WorldPacket data( SMSG_INVENTORY_CHANGE_FAILURE, (msg == EQUIP_ERR_CANT_EQUIP_LEVEL_I ? 22 : 18) );
   data << uint8(msg);

   if(msg)
   {
       data << uint64(pItem ? pItem->GetGUID() : 0);
       data << uint64(pItem2 ? pItem2->GetGUID() : 0);
       data << uint8(0);                                   // not 0 there...

       if(msg == EQUIP_ERR_CANT_EQUIP_LEVEL_I)
       {
           uint32 level = 0;

           if(pItem)
               if(ItemPrototype const* proto =  pItem->GetProto())
                   level = proto->RequiredLevel;

           data << uint32(level);                          // new 2.4.0
       }
   }
   GetSession()->SendPacket(&data);

We can see that server->client packet SMSG_INVENTORY_CHANGE_FAILURE

have 1 byte field `msg` with error type and additional fields if not ok case

EQUIP_ERR_OK = 0,

and additional fields if not ok case ( EQUIP_ERR_OK = 0,

2 possible affected item guids, then _unknown_ 1 byte field and morefields for EQUIP_ERR_CANT_EQUIP_LEVEL_I case

[echeese]

The reason I asked is because I want to write some software to make sense of the packets. Basically, output human-readable data about each packet, for example, replace the guids with the actual names, and co-ordinates instead of hex numbers. But it seems that not all the opcodes are documented, and not all the ones that are implemented are implemented entirely/correctly.