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

P4D2_2017_Spring/exercises/mri/send.py

@@ -0,0 +1,58 @@
+#!/usr/bin/env python
+
+import argparse
+import sys
+import socket
+import random
+import struct
+
+from scapy.all import sendp, send, hexdump, get_if_list, get_if_hwaddr
+from scapy.all import Packet, IPOption
+from scapy.all import Ether, IP, UDP
+from scapy.all import IntField, FieldListField, FieldLenField, ShortField
+from scapy.layers.inet import _IPOption_HDR
+
+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
+
+class IPOption_MRI(IPOption):
+    name = "MRI"
+    option = 31
+    fields_desc = [ _IPOption_HDR,
+                    FieldLenField("length", None, fmt="B",
+                                  length_of="swids",
+                                  adjust=lambda pkt,l:l+4),
+                    ShortField("count", 0),
+                    FieldListField("swids",
+                                   [],
+                                   IntField("", 0),
+                                   length_from=lambda pkt:pkt.count*4) ]
+
+
+def main():
+
+    if len(sys.argv)<3:
+        print 'pass 2 arguments: <destination> "<message>"'
+        exit(1)
+
+    addr = socket.gethostbyname(sys.argv[1])
+    iface = get_if()
+
+    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 = Ether(src=get_if_hwaddr(iface), dst="ff:ff:ff:ff:ff:ff") / IP(dst=addr, options = IPOption_MRI(count=2, swids=[3,4])) / UDP(dport=4321, sport=1234) / sys.argv[2]
+    pkt.show2()
+    #hexdump(pkt)
+    sendp(pkt, iface=iface)
+
+
+if __name__ == '__main__':
+    main()