From fff6fc933292fead4778ac6b07728fa6bf2d7704 Mon Sep 17 00:00:00 2001
From: mittorn <mittorn@sibmail.com>
Date: Thu, 23 Mar 2017 21:30:03 +0000
Subject: [PATCH] Add simple nat bypass

---
 pymaster.py     | 13 ++++++++++++-
 server_entry.py |  3 +++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/pymaster.py b/pymaster.py
index cfa54bf..f37d914 100755
--- a/pymaster.py
+++ b/pymaster.py
@@ -78,6 +78,7 @@ class PyMaster:
 		# Use NoneType as undefined
 		gamedir   = None
 		gamemap   = None # UNUSED: until Xash3D will not support full filter
+		nat = 0
 
 		for i in range( 0, len(split), 2 ):
 			try:
@@ -86,6 +87,8 @@ class PyMaster:
 					gamedir = key
 				elif( split[i] == 'map' ):
 					gamemap = key
+				elif( split[i] == 'nat' ):
+					nat = int(key)
 				else:
 					logPrint('Unhandled info string entry: {0}/{1}'.format(split[i], key))
 			except IndexError:
@@ -100,9 +103,17 @@ class PyMaster:
 			if( not i.check ):
 				continue
 
+			if( nat != i.nat ):
+				continue
+
 			if( gamedir != None ):
-				if( gamedir != i.gamedir):
+				if( gamedir != i.gamedir ):
 					continue
+
+			if( nat ):
+				# Tell server to send info reply
+				self.sock.sendto( '\xff\xff\xff\xffc {0}:{1}'.format( addr[0], addr[1] ), i.addr )
+
 			# Use pregenerated address string
 			packet += i.queryAddr
 		packet += b'\0\0\0\0\0\0' # Fill last IP:Port with \0
diff --git a/server_entry.py b/server_entry.py
index 9fdab53..46a2209 100644
--- a/server_entry.py
+++ b/server_entry.py
@@ -17,6 +17,7 @@ class ServerEntry:
 	lan = 0
 	region = 255
 	product = ''
+	nat = 0
 	
 	def setInfoString(self, data):
 		infostring = data.replace('\n', '').replace('\r', '').replace('\0', '')
@@ -54,6 +55,8 @@ class ServerEntry:
 					self.region = key
 				elif( split[i] == 'product' ):
 					self.product = key
+				elif( split[i] == 'nat' ):
+					self.nat = int(key)
 			except IndexError:
 				pass
 		self.check = self.challenge == self.challenge2