# 需要导入模块: import socket [as 别名]

# 或者: from socket import TCP_MAXSEG [as 别名]

def handle_tcp_state_tosock(self, ip):

tcp = ip.data

global tun, input

log.debug("=== NAT64 TCP sock-send: %d %s."%(tcp.flags, self.sock))

if self.sock is None:

log.warning("Socket already closed.")

return

if tcp.flags & dpkt.tcp.TH_SYN > 0:

# Use Window size to control max segment?

self.sock.setsockopt(socket.SOL_TCP, socket.TCP_MAXSEG, 1000)

log.debug("Maxseg: %d" % self.sock.getsockopt(socket.SOL_TCP, socket.TCP_MAXSEG))

self.ack = tcp.seq + 1

# We are established...

self.state = TCP_ESTABLISHED

self.window = tcp.win

# Get the MSS of the options

opts = dpkt.tcp.parse_opts(tcp.opts)

for k, v in opts:

if k == dpkt.tcp.TCP_OPT_MSS:

print("MSS:", v)

self.mss, = struct.unpack("!H", v)

print("MSS:", self.mss)

log.debug("TCP State: %d SYN received." % self.mss)

self.tcp_reply(ip, dpkt.tcp.TH_SYN | dpkt.tcp.TH_ACK)

print("IP:", repr(ip))

send_to_tun(bytes(ip))

# sock.send(ip.load)

elif tcp.flags & dpkt.tcp.TH_FIN:

self.state = TCP_FIN_CLOSE_WAIT

self.ack = tcp.seq + 1

self.timeout = time.time()

log.debug("TCP: FIN received - sending FIN. %s" % self)

self.tcp_reply(ip, dpkt.tcp.TH_FIN | dpkt.tcp.TH_ACK)

print("IP:", repr(ip))

send_to_tun(bytes(ip))

# Clean out this socket?

elif tcp.flags & dpkt.tcp.TH_ACK:

if self.state == TCP_ESTABLISHED:

if len(tcp.data) == 0:

log.debug("ESTABLISHED or ACK from other side. seq: %d ack: %d" % (tcp.seq, tcp.ack))

self.seq = tcp.ack

else:

# ACK immediately - we assume that we get data from other side soon...

log.debug("TCP: received %d seq: %d ack%d ." % (len(tcp.data), tcp.seq, tcp.ack))

self.ack = tcp.seq + len(tcp.data)

# We should also handle the sanity checks for the ACK

self.seq = tcp.ack

self.tcp_reply(ip, dpkt.tcp.TH_ACK)

print("IP:", repr(ip))

send_to_tun(bytes(ip))

add_socket(self.sock)

if len(tcp.data) > 0:

self.sock.send(tcp.data)

# Remove the state for this specific socket