Working version of the Scapy tester

test-scapy.py

@@ -1,10 +1,69 @@
-#!/usr/bin/scapy
+#!/usr/bin/python
 
-src="127.0.0.1"
-dst="127.0.0.1"
-dport = 8053
+from scapy.all import *
+import sys
+import getopt
+
+dst=None
+dport = 53
 qname = "www.slashdot.org"
 
-if src == "127.0.0.1" or src == "::1":
-    conf.L3socket = L3RawSocket
-p = IP(src=src, dst=dst)/UDP(sport=RandShort(),dport=dport)/DNS(rd=1,qd=DNSQR(qname=qname))
+def usage(msg=None):
+    print >>sys.stderr, "Usage: %s -s server-to-query [-p port-to-use] [-q query]" % sys.argv[0]
+    if msg is not None:
+        print >>sys.stderr, msg
+
+try:
+    optlist, args = getopt.getopt (sys.argv[1:], "s:p:q:h",
+                               ["server=", "port=", "query", "help"])
+    for option, value in optlist:
+        if option == "--help" or option == "-h":
+            usage()
+            sys.exit(0)
+        elif option == "--server" or option == "-s":
+            dst = value
+        elif option == "--query" or option == "-q":
+            qname = value
+        elif option == "--port" or option == "-p":
+            dport = int(value)
+        else:
+            # Should never occur, it is trapped by getopt
+            print >>sys.stderr, "Unknown option %s" % option
+            usage()
+            sys.exit(1)
+except getopt.error, reason:
+    usage(reason)
+    sys.exit(1)
+if len(args) != 0:
+    usage()
+    sys.exit(1)
+
+p = IP(dst=dst)/UDP(sport=RandShort(),dport=dport)/DNS(rd=1,qd=DNSQR(qname=qname))
+
+# Send a normal packet
+sr1(p)
+
+# Send a packet with a wrong qdcount
+p.qdcount = 0
+sr1(p)
+
+p.qdcount = 2
+sr1(p)
+
+# Modify the length field of a label
+s = str(p)
+s2 = s[:44] + '\x030' + s[45:]
+p2 = IP(s2)
+p2[UDP].sport=RandShort()
+del p2[UDP].chksum
+sr1(p2)
+
+# Truncates the packet
+s2 = s[:-4]
+p2 = IP(s2)
+p2[UDP].sport=RandShort()
+del p2[IP].len
+del p2[IP].chksum
+del p2[UDP].len 
+del p2[UDP].chksum
+sr1(p2)