[ENet-discuss] Framented packet bug ?

[Benoit Germain]

It seems that the following fixes the problem, but I'd rather have an
official fix :-)
 
 
ENetIncomingCommand *
enet_peer_queue_incoming_command (ENetPeer * peer, const ENetProtocol *
command, ENetPacket * packet, enet_uint32 fragmentCount)
{
    ENetChannel * channel = & peer -> channels [command ->
header.channelID];
    enet_uint32 unreliableSequenceNumber = 0;
    ENetIncomingCommand * incomingCommand;
    ENetListIterator currentCommand;
 
    switch (command -> header.command)
    {
+   case ENET_PROTOCOL_COMMAND_SEND_FRAGMENT:
    case ENET_PROTOCOL_COMMAND_SEND_RELIABLE:
       for (currentCommand = enet_list_previous (enet_list_end (& channel ->
incomingReliableCommands));

 
There is another bug though, when the data being sent spans more that 32
fragments: the fragment reception bitfield is not properly updated, which
causes all fragments above 32 included to be dropped, because (1<<n) where
n>31 is always 0.  Thus the following fix. BTW, note that data copying into
the reunited packet needs only to be done for new received fragments, hence
the enclosing braces that I added:

 
-   if ((startCommand -> fragments [fragmentNumber / 32] & (1 <<
fragmentNumber)) == 0)
+   if ((startCommand -> fragments [fragmentNumber / 32] & (1 <<
(fragmentNumber & 31))) == 0)
+   {
      -- startCommand -> fragmentsRemaining;
 
-    startCommand -> fragments [fragmentNumber / 32] |= (1 <<
fragmentNumber);
+    startCommand -> fragments [fragmentNumber / 32] |= (1 <<
(fragmentNumber & 31));
 
      if (fragmentOffset + fragmentLength > startCommand -> packet ->
dataLength)
        fragmentLength = startCommand -> packet -> dataLength -
fragmentOffset;
 
      memcpy (packet_data(startCommand -> packet) + fragmentOffset,
              (enet_uint8 *) command + sizeof (ENetProtocolSendFragment),
              fragmentLength);
+   }
}
 
 

__________________________________ 
Benoit Germain 
][ Engineer 
mailto:bgermain at ubisoft.fr <mailto:bgermain at ubisoft.fr>  
__________________________________ 

 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.puremagic.com/pipermail/enet-discuss/attachments/20041209/03675b88/attachment.htm