Created new subdirectory for Fall developer day. (#60)

P4D2_2017_Spring/exercises/ipv4_forward/send.py

@@ -0,0 +1,40 @@
+#!/usr/bin/env python
+import argparse
+import sys
+import socket
+import random
+import struct
+
+from scapy.all import sendp, send, get_if_list, get_if_hwaddr
+from scapy.all import Packet
+from scapy.all import Ether, IP, UDP
+
+def get_if():
+    ifs=get_if_list()
+    iface=None # "h1-eth0"
+    for i in get_if_list():
+        if "eth0" in i:
+            iface=i
+            break;
+    if not iface:
+        print "Cannot find eth0 interface"
+        exit(1)
+    return iface
+
+def main():
+
+    if len(sys.argv)<3:
+        print 'pass 2 arguments: <destination> "<message>"'
+        exit(1)
+
+    addr = socket.gethostbyname(sys.argv[1])
+    iface = get_if()
+
+    print "sending on interface %s to %s" % (iface, str(addr))
+    pkt =  Ether(src=get_if_hwaddr(iface), dst='ff:ff:ff:ff:ff:ff') / IP(dst=addr) / UDP(dport=4321, sport=1234) / sys.argv[2]
+    pkt.show2()
+    sendp(pkt, iface=iface, verbose=False)
+
+
+if __name__ == '__main__':
+    main()