def est_connection(self):
my_syn = Packet(src=self.client_port,
dst=self.server_port,
seq_num=0,
ack_num=0,
data=b'',
ctrl_bits=0x02)
packed = my_syn.pkt_pack()
self.client_socket.sendto(packed, self.server_addr)
try:
syn_ack = Packet()
recv_data = self.client_socket.recv(self.pkt_size)
syn_ack.pkt_unpack(recv_data)
if syn_ack.get_ack_bit() and syn_ack.ack_num == 1:
self.conn_est = True
print("Client: Sending ACK for SYNACK")
my_syn = Packet(src=self.client_port,
dst=self.server_port,
seq_num=0,
ack_num=1,
data=b'',
ctrl_bits=0x10)
packed = my_syn.pkt_pack()
self.client_socket.sendto(packed, self.server_addr)
else:
print("Client: Connection failed: bad SYNACK")
except socket.timeout:
print("Client: Connection failed: timeout")
def est_connection(self, syn_pkt: Packet):
self.client_port = syn_pkt.src
my_syn = Packet(self.server_port, self.client_port, 0,
syn_pkt.ack_num + 1, b'',
0x12) # ack bit = 1, syn bit = 1
packed = my_syn.pkt_pack()
self.server_socket.sendto(packed, self.client_addr)
try:
syn_ack = Packet()
recv_data = self.server_socket.recv(self.pkt_size)
syn_ack.pkt_unpack(recv_data)
if syn_ack.get_ack_bit() and syn_ack.ack_num == 1:
self.conn_est = True
print("Server: Connection established")
else:
print("Server: Connection failed: bad SYNACK")
except socket.timeout:
print("Server: Connection failed: timeout")