Redes-TP3/servlet.py at master · FeRamalho/Redes-TP3 · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
import socket
import sys
import struct

def main():

	# Input arguments
	port = int(sys.argv[1])
	input_name = sys.argv[2]
	peer_list = []
	for peer in range(3, len(sys.argv)):
		peer_list.append(sys.argv[peer])
	host = socket.gethostbyname(socket.gethostname())
	print("IP:",host)
	print('Port:', port)
	# DICT
	keys = {}
	connections = []
	seen_req = {}

	# Peer connections    peer_list = string   connections  =
	for peer in peer_list:
		peer_ip, x , peer_port = peer.partition(':')
		connections.append( (peer_ip, int(peer_port)) )
	# Reading keys from input
	input_file = open(input_name, 'r')
	for line in input_file:
		# Not comments
		if not line.startswith('#'):
			key, x, value = line.partition(' ')
			value = value.strip(' ')
			value = value.strip('\n')
			keys[key] = value
	input_file.close()

	# Create udp socket
	sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
	# Bind socket to port
	#my_address = ('127.0.0.1', port)
	my_address = (host, port)
	sock.bind(my_address)

	# Start application
	while(1):
		data, address = sock.recvfrom(500)
		ip_origem = address[0]
		port_origem = address[1]
		typ = struct.unpack('!H',data[:2])[0]

		# KEY REQ
		if(typ == 5):
			numsq = struct.unpack('!I', data[2:6])[0]
			reqkey = data[6:].decode()
			if(reqkey in keys.keys()):
				answer = struct.pack('!H', 9) + struct.pack('!I', numsq) + keys[reqkey].encode()
				sock.sendto(answer, address)
			# Not seen this req
			if(address not in seen_req.keys() or [address] != numsq):
				ip4bytes = socket.inet_aton(address[0])
				keyflood = struct.pack('!H', 7) + struct.pack('!H', 3) + struct.pack('!I', numsq) + \
				ip4bytes + struct.pack('!H', address[1]) + reqkey.encode()
				seen_req[address] = numsq
				for peer in connections:
					if( peer != address ):
						sock.sendto(keyflood, peer)

		# TOPO REQ
		elif(typ == 6):
			numsq = struct.unpack('!I', data[2:6])[0]
			# Not seen this req
			if(address not in seen_req.keys() or seen_req[address] != numsq):
				ip4bytes = socket.inet_aton(address[0])
				#topoflood com a info no final (ip:porto do servent)
				ipsend = ":".join((ip_origem,str(port)))
				topoflood = struct.pack('!H', 8) + struct.pack('!H', 3) + struct.pack('!I', numsq) + ip4bytes + struct.pack('!H', address[1]) + \
				 ipsend.encode()
				seen_req[address] = numsq
				for peer in connections:
					if( peer != address ):
						sock.sendto(topoflood, peer)
				#servent envia pro client
				origem = (address[0], address[1])
				answer = struct.pack('!H', 9) + struct.pack('!I', numsq) + topoflood[14:]
				sock.sendto(answer, origem)

		#  FLOOD
		elif(typ == 7 or typ == 8):
			ttl = struct.unpack('!H', data[2:4])[0]
			numsq = struct.unpack('!I', data[4:8])[0]
			ip_origem = socket.inet_ntoa(data[8:12])
			port_origem = struct.unpack('!H', data[12:14])[0]
			origem = (ip_origem, port_origem)
			# KEY FLOOD
			if(typ == 7):
				reqkey = data[14:].decode()
				if(reqkey in keys.keys()):
					if(origem not in seen_req.keys() or seen_req[origem] != numsq ): ###check if seen this client
						seen_req[origem] = numsq ###att seen_req
						answer = struct.pack('!H', 9) + struct.pack('!I', numsq) + keys[reqkey].encode()
						sock.sendto(answer, origem)
			# TOPO FLOOD
			elif(typ == 8):
				if(origem not in seen_req.keys() or seen_req[origem] != numsq ): ###check if seen this client
					seen_req[origem] = numsq ###att seen_req
					ipsend = ":".join((host,str(my_address[1])))
					ipsend = " " + ipsend
					answer = struct.pack('!H', 9) + struct.pack('!I', numsq) + data[14:] + ipsend.encode()
					sock.sendto(answer, origem)
			# FLOOD
			if(ttl > 0):
				ttl = ttl -1
				ip4bytes = socket.inet_aton(origem[0])
				flood = struct.pack('!H', typ) + struct.pack('!H', ttl) + struct.pack('!I', numsq) + \
				ip4bytes + struct.pack('!H', origem[1]) + data[14:]
				if(typ == 8):
					#colocar um espaço e o meu ip no final como string ip:port
					ipsend1 = ":".join((host,str(port)))
					ipsend1 = " " + ipsend1
					flood += ipsend1.encode()

				for peer in connections:
					if( peer != address ):
						sock.sendto(flood, peer)

	sock.close()

if __name__ == "__main__":
	main()