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

* 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

1 files changed, 8 insertions, 8 deletions

diff --git a/src/connection.cpp b/src/connection.cpp
index dd7ff597b..42262846f 100644
--- a/src/connection.cpp
+++ b/src/connection.cpp
@@ -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)
 	{