#!/usr/bin/python

import struct
import socket
import asyncore
import binascii
import time
import sys
import re
import random
import cStringIO
import hashlib

MY_VERSION = 31800
MY_SUBVERSION = ".4"

settings = {
	"host": "86.91.195.94",
	"port": 8333,
	"debug": True
}

def sha256(s):
	return hashlib.new('sha256', s).digest()

def deser_string(f):
	nit = struct.unpack("<B", f.read(1))[0]
	if nit == 253:
		nit = struct.unpack("<H", f.read(2))[0]
	elif nit == 254:
		nit = struct.unpack("<I", f.read(4))[0]
	elif nit == 255:
		nit = struct.unpack("<Q", f.read(8))[0]
	return f.read(nit)

def ser_string(s):
	if len(s) < 253:
		return chr(len(s)) + s
	elif len(s) < 0x10000:
		return chr(253) + struct.pack("<H", len(s)) + s
	elif len(s) < 0x100000000L:
		return chr(254) + struct.pack("<I", len(s)) + s
	return chr(255) + struct.pack("<Q", len(s)) + s


def deser_vector(f, c):
	nit = struct.unpack("<B", f.read(1))[0]
	if nit == 253:
		nit = struct.unpack("<H", f.read(2))[0]
	elif nit == 254:
		nit = struct.unpack("<I", f.read(4))[0]
	elif nit == 255:
		nit = struct.unpack("<Q", f.read(8))[0]
	r = []
	for i in xrange(nit):
		t = c()
		t.deserialize(f)
		r.append(t)
	return r

def ser_vector(l):
	r = ""
	if len(l) < 253:
		r = chr(len(l))
	elif len(l) < 0x10000:
		r = chr(253) + struct.pack("<H", len(l))
	elif len(l) < 0x100000000L:
		r = chr(254) + struct.pack("<I", len(l))
	else:
		r = chr(255) + struct.pack("<Q", len(l))
	for i in l:
		r += i.serialize()
	return r




def show_debug_msg(msg):
	if settings['debug']:
		print "DEBUG: " + msg

class CAddress(object):
	def __init__(self):
		self.nServices = 1
		self.pchReserved = "\x00" * 10 + "\xff" * 2
		self.ip = "0.0.0.0"
		self.port = 0
	def deserialize(self, f):
		self.nServices = struct.unpack("<Q", f.read(8))[0]
		self.pchReserved = f.read(12)
		self.ip = socket.inet_ntoa(f.read(4))
		self.port = struct.unpack(">H", f.read(2))[0]
	def serialize(self):
		r = ""
		r += struct.pack("<Q", self.nServices)
		r += self.pchReserved
		r += socket.inet_aton(self.ip)
		r += struct.pack(">H", self.port)
		return r
	def __repr__(self):
		return "CAddress(nServices=%i ip=%s port=%i)" % (self.nServices, self.ip, self.port)


class msg_version(object):
	command = "version"
	def __init__(self):
		self.nVersion = MY_VERSION
		self.nServices = 1
		self.nTime = time.time()
		self.addrTo = CAddress()
		self.addrFrom = CAddress()
		self.nNonce = random.getrandbits(64)
		self.strSubVer = MY_SUBVERSION
		self.nStartingHeight = -1
	def deserialize(self, f):
		self.nVersion = struct.unpack("<i", f.read(4))[0]
		if self.nVersion == 10300:
			self.nVersion = 300
		self.nServices = struct.unpack("<Q", f.read(8))[0]
		self.nTime = struct.unpack("<q", f.read(8))[0]
		self.addrTo = CAddress()
		self.addrTo.deserialize(f)
		if self.nVersion >= 106:
			self.addrFrom = CAddress()
			self.addrFrom.deserialize(f)
			self.nNonce = struct.unpack("<Q", f.read(8))[0]
			self.strSubVer = deser_string(f)
			if self.nVersion >= 209:
				self.nStartingHeight = struct.unpack("<i", f.read(4))[0]
			else:
				self.nStartingHeight = None
		else:
			self.addrFrom = None
			self.nNonce = None
			self.strSubVer = None
			self.nStartingHeight = None
	def serialize(self):
		r = ""
		r += struct.pack("<i", self.nVersion)
		r += struct.pack("<Q", self.nServices)
		r += struct.pack("<q", self.nTime)
		r += self.addrTo.serialize()
		r += self.addrFrom.serialize()
		r += struct.pack("<Q", self.nNonce)
		r += ser_string(self.strSubVer)
		r += struct.pack("<i", self.nStartingHeight)
		return r
	def __repr__(self):
		return "msg_version(nVersion=%i nServices=%i nTime=%s addrTo=%s addrFrom=%s nNonce=0x%016X strSubVer=%s nStartingHeight=%i)" % (self.nVersion, self.nServices, time.ctime(self.nTime), repr(self.addrTo), repr(self.addrFrom), self.nNonce, self.strSubVer, self.nStartingHeight)

class msg_verack(object):
	command = "verack"
	def __init__(self):
		pass
	def deserialize(self, f):
		pass
	def serialize(self):
		return ""
	def __repr__(self):
		return "msg_verack()"

class msg_addr(object):
	command = "addr"
	def __init__(self):
		self.addrs = []
	def deserialize(self, f):
		self.addrs = deser_vector(f, CAddress)
	def serialize(self):
		return ser_vector(self.addrs)
	def __repr__(self):
		return "msg_addr(addrs=%s)" % (repr(self.addrs))




class msg_getaddr(object):
	command = "getaddr"
	def __init__(self):
		pass
	def deserialize(self, f):
		pass
	def serialize(self):
		return ""
	def __repr__(self):
		return "msg_getaddr()"



class NodeConn(asyncore.dispatcher):
	messagemap = {
		"version": msg_version,
		"verack": msg_verack,
		"addr": msg_addr,
		"getaddr": msg_getaddr
	}
	def __init__(self, dstaddr, dstport):
		asyncore.dispatcher.__init__(self)
		self.dstaddr = dstaddr
		self.dstport = dstport
		self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
		self.sendbuf = ""
		self.recvbuf = ""
		self.ver_send = 209
		self.ver_recv = 209
		self.last_sent = 0
		self.state = "connecting"

		#stuff version msg into sendbuf
		vt = msg_version()
		vt.addrTo.ip = self.dstaddr
		vt.addrTo.port = self.dstport
		vt.addrFrom.ip = "0.0.0.0"
		vt.addrFrom.port = 0
		self.send_message(vt, True)
		print "\n Bitcoin Network Sniffer"
		print " -------------------------------------------------------------------------"
		print " Connecting to Bitcoin Node IP # " + settings['host'] + ":" + str(settings['port'])
		try:
			self.connect((dstaddr, dstport))
		except:
			self.handle_close()
	def handle_connect(self):
		print " Connected & Sniffing :)\n"
		self.state = "connected"
	def handle_close(self):
		print " Closing Conection ... bye :)"
		self.state = "closed"
		self.recvbuf = ""
		self.sendbuf = ""
		try:
			self.close()
		except:
			pass
	def handle_read(self):
		try:
			t = self.recv(8192)
		except:
			self.handle_close()
			return
		if len(t) == 0:
			self.handle_close()
			return
		self.recvbuf += t
		self.got_data()
	def readable(self):
		return True
	def writable(self):
		return (len(self.sendbuf) > 0)
	def handle_write(self):
		try:
			sent = self.send(self.sendbuf)
		except:
			self.handle_close()
			return
		self.sendbuf = self.sendbuf[sent:]
	def got_data(self):
		while True:
			if len(self.recvbuf) < 4:
				return
			if self.recvbuf[:4] != "\xf9\xbe\xb4\xd9":
				raise ValueError("got garbage %s" % repr(self.recvbuf))
			if self.ver_recv < 209:
				if len(self.recvbuf) < 4 + 12 + 4:
					return
				command = self.recvbuf[4:4+12].split("\x00", 1)[0]
				msglen = struct.unpack("<i", self.recvbuf[4+12:4+12+4])[0]
				checksum = None
				if len(self.recvbuf) < 4 + 12 + 4 + msglen:
					return
				msg = self.recvbuf[4+12+4:4+12+4+msglen]
				self.recvbuf = self.recvbuf[4+12+4+msglen:]
			else:
				if len(self.recvbuf) < 4 + 12 + 4 + 4:
					return
				command = self.recvbuf[4:4+12].split("\x00", 1)[0]
				msglen = struct.unpack("<i", self.recvbuf[4+12:4+12+4])[0]
				checksum = self.recvbuf[4+12+4:4+12+4+4]
				if len(self.recvbuf) < 4 + 12 + 4 + 4 + msglen:
					return
				msg = self.recvbuf[4+12+4+4:4+12+4+4+msglen]
				th = sha256(msg)
				h = sha256(th)
				if checksum != h[:4]:
					raise ValueError("got bad checksum %s" % repr(self.recvbuf))
				self.recvbuf = self.recvbuf[4+12+4+4+msglen:]
			if command in self.messagemap:
				f = cStringIO.StringIO(msg)
				t = self.messagemap[command]()
				t.deserialize(f)
				self.got_message(t)
			else:
				show_debug_msg("Unknown command: " + command)
	
	def send_message(self, message, pushbuf=False):
		if self.state != "connected" and not pushbuf:
			return
		show_debug_msg("Send %s" % repr(message))
		command = message.command
		data = message.serialize()
		tmsg = "\xf9\xbe\xb4\xd9"
		tmsg += command
		tmsg += "\x00" * (12 - len(command))
		tmsg += struct.pack("<I", len(data))
		if self.ver_send >= 209:
			th = sha256(data)
			h = sha256(th)
			tmsg += h[:4]
		tmsg += data
		self.sendbuf += tmsg
		self.last_sent = time.time()
	def got_message(self, message):
		show_debug_msg("Recv %s" % repr(message))
		if message.command  == "version":
			if message.nVersion >= 209:
				self.send_message(msg_verack())
			self.ver_send = min(MY_VERSION, message.nVersion)
			if message.nVersion < 209:
				self.ver_recv = self.ver_send
		elif message.command == "verack":
			self.ver_recv = self.ver_send
			self.send_message(msg_getaddr())
			
if __name__ == '__main__':
	settings['port'] = int(settings['port'])
	c = NodeConn(settings['host'], settings['port'])
	asyncore.loop()