From 99658cb49ce60cc9dd7a85503608e0bd19531406 Mon Sep 17 00:00:00 2001
From: Christian Ulrich <christian@ulrich.earth>
Date: Tue, 6 Oct 2020 23:50:13 +0200
Subject: [PATCH] close raw sockets too

---
 tcp_syni.nim | 39 +++++++++++++++++++++++----------------
 1 file changed, 23 insertions(+), 16 deletions(-)

diff --git a/tcp_syni.nim b/tcp_syni.nim
index 8e66def..0587b21 100644
--- a/tcp_syni.nim
+++ b/tcp_syni.nim
@@ -95,6 +95,7 @@ proc injectTcpPacket(rawFd: AsyncFD, ipPacket: IpPacket) {.async.} =
 proc captureSeqNumbers(attempt: ConnectAttempt, rawFd: AsyncFD,
                        cb: PunchProgressCb) {.async.} =
   # FIXME: timeout?
+  # FIXME: create raw socket here
   var seqNums = newSeq[uint32]()
   while seqNums.len < attempt.dstPorts.len:
     let packet = await rawFd.recv(4000)
@@ -110,26 +111,31 @@ proc captureSeqNumbers(attempt: ConnectAttempt, rawFd: AsyncFD,
         if parsed.tcpPortDst.int == port.int:
           seqNums.add(parsed.tcpSeqNumber)
           break
+  closeSocket(rawFd)
   await cb(seqNums)
 
 proc captureAndResendAck(attempt: ConnectAttempt, captureFd: AsyncFD,
                          injectFd: AsyncFD) {.async.} =
-  while true:
-    let packet = await captureFd.recv(4000)
-    if packet == "":
-      break
-    var parsed = parseEthernetPacket(packet)
-    if parsed.protocol == tcp and
-       parsed.ipAddrSrc == attempt.srcIp and
-       parsed.tcpPortSrc.int == attempt.srcPort.int and
-       parsed.ipAddrDst == attempt.dstIp and
-       parsed.tcpFlags == {ACK}:
-      for port in attempt.dstPorts:
-        if parsed.tcpPortDst.int == port.int:
-          parsed.ipTTL = 64
-          echo &"[{parsed.ipAddrSrc}:{parsed.tcpPortSrc.int} -> {parsed.ipAddrDst}:{parsed.tcpPortDst}, SEQ {parsed.tcpSeqNumber}] resending ACK with TTL {parsed.ipTTL}"
-          await injectFd.injectTcpPacket(parsed)
-          return
+  # FIXME: create raw socket here
+  block loops:
+    while true:
+      let packet = await captureFd.recv(4000)
+      if packet == "":
+        break
+      var parsed = parseEthernetPacket(packet)
+      if parsed.protocol == tcp and
+         parsed.ipAddrSrc == attempt.srcIp and
+         parsed.tcpPortSrc.int == attempt.srcPort.int and
+         parsed.ipAddrDst == attempt.dstIp and
+         parsed.tcpFlags == {ACK}:
+        for port in attempt.dstPorts:
+          if parsed.tcpPortDst.int == port.int:
+            parsed.ipTTL = 64
+            echo &"[{parsed.ipAddrSrc}:{parsed.tcpPortSrc.int} -> {parsed.ipAddrDst}:{parsed.tcpPortDst}, SEQ {parsed.tcpSeqNumber}] resending ACK with TTL {parsed.ipTTL}"
+            await injectFd.injectTcpPacket(parsed)
+            break loops
+  closeSocket(captureFd)
+  closeSocket(injectFd)
 
 proc initPuncher*(): TcpSyniPuncher = TcpSyniPuncher()
 
@@ -291,6 +297,7 @@ proc accept*(puncher: TcpSyniPuncher, srcPort: Port, dstIp: IpAddress,
                                 tcpFlags: {SYN}, tcpWindowSize: 1452 * 10)
         echo &"[{ipPacket.ipAddrSrc}:{ipPacket.tcpPortSrc} -> {ipPacket.ipAddrDst}:{ipPacket.tcpPortDst}, SEQ {ipPacket.tcpSeqNumber}] injecting SYN"
         asyncCheck rawFd.injectTcpPacket(ipPacket)
+    closeSocket(rawFd)
     await attempt.future or sleepAsync(Timeout)
     await attempt.deleteFirewallRules()
     puncher.acceptAttempts.del(puncher.acceptAttempts.find(attempt))