pf tests: Move Sniffer to its own file

Make it easier to re-use the sniffer class in other test support
scripts.

tests/sys/netpfil/pf/Makefile

@@ -20,6 +20,7 @@ ATF_TESTS_SH+=	anchor \
 
 ${PACKAGE}FILES+=	utils.subr \
 			echo_inetd.conf \
+			sniffer.py \
 			pft_ping.py \
 			CVE-2019-5597.py
 

tests/sys/netpfil/pf/pft_ping.py

@@ -3,31 +3,10 @@
 import argparse
 import scapy.all as sp
 import sys
-import threading
+from sniffer import Sniffer
 
 PAYLOAD_MAGIC = 0x42c0ffee
 
-class Sniffer(threading.Thread):
-	def __init__(self, args, check_function):
-		threading.Thread.__init__(self)
-
-		self._args = args
-		self._recvif = args.recvif[0]
-		self._check_function = check_function
-		self.foundCorrectPacket = False
-
-		self.start()
-
-	def _checkPacket(self, packet):
-		ret = self._check_function(self._args, packet)
-		if ret:
-			self.foundCorrectPacket = True
-		return ret
-
-	def run(self):
-		self.packets = sp.sniff(iface=self._recvif,
-				stop_filter=self._checkPacket, timeout=3)
-
 def check_ping_request(args, packet):
 	if args.ip6:
 		return check_ping6_request(args, packet)

tests/sys/netpfil/pf/sniffer.py

@@ -0,0 +1,25 @@
+# $FreeBSD$
+
+import threading
+import scapy.all as sp
+
+class Sniffer(threading.Thread):
+	def __init__(self, args, check_function):
+		threading.Thread.__init__(self)
+
+		self._args = args
+		self._recvif = args.recvif[0]
+		self._check_function = check_function
+		self.foundCorrectPacket = False
+
+		self.start()
+
+	def _checkPacket(self, packet):
+		ret = self._check_function(self._args, packet)
+		if ret:
+			self.foundCorrectPacket = True
+		return ret
+
+	def run(self):
+		self.packets = sp.sniff(iface=self._recvif,
+				stop_filter=self._checkPacket, timeout=3)