From ddbae1da865fad908503c496eb2a8d1cca57078c Mon Sep 17 00:00:00 2001
From: Arvid Norberg <arvid@libtorrent.org>
Date: Sat, 19 May 2012 20:39:55 +0000
Subject: [PATCH] don't accept incoming uTP connections indefinitely

---
 src/utp_socket_manager.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/utp_socket_manager.cpp b/src/utp_socket_manager.cpp
index 729103a20..6865d86b7 100644
--- a/src/utp_socket_manager.cpp
+++ b/src/utp_socket_manager.cpp
@@ -245,6 +245,10 @@ namespace libtorrent
 		// create a new utp_stream
 		if (ph->get_type() == ST_SYN)
 		{
+			// possible SYN flood. Just ignore
+			if (m_utp_sockets.size() > m_sett.connections_limit * 2)
+				return false;
+
 			// create the new socket with this ID
 			m_new_connection = id;