From cd3a7e99f5ef53b5c3749a1f59e26081429a66ec Mon Sep 17 00:00:00 2001
From: Christian Ulrich <christian@ulrich.earth>
Date: Sun, 22 Nov 2020 14:06:25 +0100
Subject: [PATCH] fix maximum number of outbound packets and maximum number of
 sockets

---
 puncher.nim | 27 +++++++++++++--------------
 1 file changed, 13 insertions(+), 14 deletions(-)

diff --git a/puncher.nim b/puncher.nim
index f1eb304..9a80796 100644
--- a/puncher.nim
+++ b/puncher.nim
@@ -27,9 +27,10 @@ var IPPROTO_IP {.importc: "IPPROTO_IP", header: "<netinet/in.h>".}: cint
 var IP_TTL {.importc: "IP_TTL", header: "<netinet/in.h>".}: cint
 
 const Timeout = 3000
-const InitiatorMaxSockCount = 1000
-const ResponderMaxSockCount = 70
-const MaxSockCount = max(InitiatorMaxSockCount, ResponderMaxSockCount)
+const InitiatorMaxOutPacketCount = 1000
+const ResponderMaxOutPacketCount = 70
+const MaxOutPacketCount = max(InitiatorMaxOutPacketCount,
+                              ResponderMaxOutPacketCount)
 
 proc srcPort(sock: AsyncSocket): Port =
   result = sock.getLocalAddr[1]
@@ -50,8 +51,8 @@ proc initPuncher*(sock: AsyncSocket, probedSrcPorts: seq[Port]): Puncher =
     # our NAT is of the evil symmetric type with random port allocation. We are
     # trying to help the other peer by allocating a lot of auxillary sockets
     # for punching more holes
-    result.socks.setLen(MaxSockCount)
-    for i in 1 .. MaxSockCount - 1:
+    result.socks.setLen(MaxOutPacketCount)
+    for i in 1 .. MaxOutPacketCount - 1:
       result.socks[i] = newAsyncSocket(sockType = SOCK_DGRAM,
                                        protocol = IPPROTO_UDP, buffered = false)
       result.socks[i].bindAddr(Port(0))
@@ -64,20 +65,18 @@ proc punch(puncher: Puncher, peerIp: IpAddress, peerPort: Port,
           Future[Attempt] {.async.} =
   let punchFuture = newFuture[(AsyncSocket, Port)]("punch")
   let peerNatProps = getNatProperties(peerPort, peerProbedPorts)
+  let maxOutPacketCount = if isInitiating:
+    InitiatorMaxOutPacketCount
+  else:
+    ResponderMaxOutPacketCount
   var sockCount = 1
   if puncher.natProps.natType == SymmetricRandom:
-    # Our NAT is of the evil symmetric type with random port allocation. We are
-    # trying to help the other peer by punching more holes using all our
-    # sockets.
     if peerNatProps.natType == SymmetricRandom:
-      # If the other peer is behind a SymmetricRandom NAT too we give up.
+      # If both peers are behind a SymmetricRandom NAT we give up.
       raise newException(PunchHoleError,
                          "both peers behind symmetric NAT with random port allocation")
-    sockCount = if isInitiating:
-      InitiatorMaxSockCount
-    else:
-      ResponderMaxSockCount
-  let predictedDstPorts = predictPortRange(peerNatProps, sockCount.uint16)
+    sockCount = maxOutPacketCount
+  let predictedDstPorts = predictPortRange(peerNatProps, maxOutPacketCount.uint16)
   result = Attempt(dstIp: peerIp, dstPorts: predictedDstPorts,
                    future: punchFuture)
   if puncher.attempts.contains(result):