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Fix server getting completely choked up on even a little of DoS

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* If client count is unbearable, immediately delete denied clients
* Re-prioritize the checking order of things about incoming clients
* Remove a huge CPU-wasting exception in ReliablePacketBuffer
This commit is contained in:
Perttu Ahola 2013-08-04 08:17:07 +03:00
parent 8831669505
commit e6687be493
4 changed files with 229 additions and 168 deletions
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16
src/connection.cpp
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@ -207,12 +207,13 @@ RPBSearchResult ReliablePacketBuffer::notFound()
{
return m_list.end();
}
u16 ReliablePacketBuffer::getFirstSeqnum()
bool ReliablePacketBuffer::getFirstSeqnum(u16 *result)
{
if(empty())
throw NotFoundException("Buffer is empty");
return false;
BufferedPacket p = *m_list.begin();
return readU16(&p.data[BASE_HEADER_SIZE+1]);
*result = readU16(&p.data[BASE_HEADER_SIZE+1]);
return true;
}
BufferedPacket ReliablePacketBuffer::popFirst()
{
@ -700,7 +701,7 @@ void Connection::receive()
bool single_wait_done = false;
for(;;)
for(u32 loop_i=0; loop_i<1000; loop_i++) // Limit in case of DoS
{
try{
/* Check if some buffer has relevant data */
@ -1245,17 +1246,16 @@ bool Connection::checkIncomingBuffers(Channel *channel, u16 &peer_id,
{
u16 firstseqnum = 0;
// Clear old packets from start of buffer
try{
for(;;){
firstseqnum = channel->incoming_reliables.getFirstSeqnum();
bool found = channel->incoming_reliables.getFirstSeqnum(&firstseqnum);
if(!found)
break;
if(seqnum_higher(channel->next_incoming_seqnum, firstseqnum))
channel->incoming_reliables.popFirst();
else
break;
}
// This happens if all packets are old
}catch(con::NotFoundException)
{}
if(channel->incoming_reliables.empty() == false)
{