dhcp client

dhcptest.py

@@ -0,0 +1,94 @@
+#!/usr/bin/env python
+
+import struct
+import socket
+
+class DHCPPack:
+    fmt = "BBBBIHH4B4B4B4B8H64s128s"
+    def __init__(self,data=None):
+        if data is not None:
+            info = struct.unpack(DHCPPack.fmt, data)
+            self.op = info[0]
+            self.htype = info[1]
+            self.hlen = info[2]
+            self.hops = info[3]
+            self.xid = info[4]
+            self.secs = info[5]
+            self.flags = info[6]
+            self.ciaddr = tuple(info[7:10])
+            self.yiaddr = tuple(info[11:14])
+            self.siaddr = tuple(info[15:18])
+            self.giaddr = tuple(info[19:22])
+            self.chaddr = tuple(info[23:30])
+            self.sname = info[31]
+            self.file = info[32]
+        else:
+            self.op = 1
+            self.htype = 1
+            self.hlen = 6
+            self.hops = 0
+            self.xid = 0
+            self.secs = 0
+            self.flags = 0
+            self.ciaddr = (0,0,0,0)
+            self.yiaddr = (0,0,0,0)
+            self.siaddr = (0,0,0,0)
+            self.giaddr = (0,0,0,0)
+            self.chaddr = (0xDE,0xAD,0xBE,0xEF,0x13,0x37,0x13,0x37)
+            self.sname = ""
+            self.file = ""
+
+    def pack(self):
+        return struct.unpack(DHCPPack.fmt,
+                self.op,
+                self.htype,
+                self.hlen,
+                self.hops,
+                self.xid,
+                self.secs,
+                self.flags,
+                self.ciaddr[0],
+                self.ciaddr[1],
+                self.ciaddr[2],
+                self.ciaddr[3],
+                self.yiaddr[0],
+                self.yiaddr[1],
+                self.yiaddr[2],
+                self.yiaddr[3],
+                self.siaddr[0],
+                self.siaddr[1],
+                self.siaddr[2],
+                self.siaddr[3],
+                self.giaddr[0],
+                self.giaddr[1],
+                self.giaddr[2],
+                self.giaddr[3],
+                self.chaddr[0],
+                self.chaddr[1],
+                self.chaddr[2],
+                self.chaddr[3],
+                self.chaddr[4],
+                self.chaddr[5],
+                self.chaddr[6],
+                self.chaddr[7],
+                self.sname,
+                self.file)
+
+
+def main():
+    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    s.bind(('',68))
+    s.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
+
+    packet = DHCPPack();
+    s.sendto(packet.pack(), ('<broadcast>',67))
+
+    data, addr = sock.recvfrom(1024)
+
+    packet2 = DHCPPack(data)
+    if packet2.op == 2:
+        print("Got answer")
+    else:
+        print("WTF")
+
+main()