def recv(cls, ipv4_packet):
udp_packet = UdpPacket(ipv4_packet.payload)
udp_packet.log("info", "TAKE")
from core.sock import SockManager
remote_info = ipv4_packet.src_ip_addr, udp_packet.src_port
local_info = ipv4_packet.dst_ip_addr, udp_packet.dst_port
sock = SockManager.lookup_unidirectional_sock(Udp.PROT_TYPE,
remote_info, local_info)
sock._remote_ip_addr = ipv4_packet.src_ip_addr
sock._remote_port = udp_packet.src_port
if sock is None:
udp_packet.log("error", "NO SOCK")
return
sock.enqueue_data(udp_packet.payload)
def recv(cls, ipv4_packet):
tcp_packet = TcpPacket(ipv4_packet.payload)
tcp_packet.LOG("info", "TAKE")
from core.sock import SockManager
local_info = ipv4_packet.dst_ip_addr, tcp_packet.dst_port
remote_info = ipv4_packet.src_ip_addr, tcp_packet.src_port
sock = SockManager.lookup_bidirectional_sock(Tcp.PROT_TYPE, local_info, remote_info)
if sock is None:
sock = SockManager.lookup_unidirectional_sock(Tcp.PROT_TYPE, local_info)
if sock is None:
tcp_packet.LOG("error", "no sock")
return
sock = SockManager.register_bidirectional_sock(Tcp.PROT_TYPE, remote_info, local_info)
sock.state = "TCP_LISTEN"
sock.LOG("info", "START")
Tcp.tcp_state_transform(sock, ipv4_packet, tcp_packet)
sock.LOG("info", "FINISH")
def tcp_state_transform(cls, sock, ipv4_packet, tcp_packet):
if tcp_packet.syn == 1:
sock.seq = tcp_packet.seq_no
sock.ack = tcp_packet.seq_no
sock._snd_una = tcp_packet.seq_no
sock._snd_nxt = tcp_packet.seq_no
sock._rcv_nxt = tcp_packet.seq_no
# handle ack
if tcp_packet.ack == 1:
sock._snd_una = max(sock._snd_una, tcp_packet.ack_no)
sock.seq = max(sock.seq, tcp_packet.ack_no)
if tcp_packet.syn == 1 or tcp_packet.psh == 1:
# if tcp_packet.ack_no != sock.seq or tcp_packet.seq_no != sock.ack:
# sock.LOG("error", "ACK SEQ NO ERROR")
sock.ack += max(1, len(tcp_packet.payload))
sock._rcv_nxt += max(1, len(tcp_packet.payload))
local_info = ipv4_packet.dst_ip_addr, tcp_packet.dst_port
remote_info = ipv4_packet.src_ip_addr, tcp_packet.src_port
if sock.state == "TCP_LISTEN":
# -> TCP_SYN_RECV
tcp_packet.LOG("info", "TCP_LISTEN -> TCP_SYN_RECV")
sock.LOG("info", "TCP_LISTEN -> TCP_SYN_RECV")
Tcp.save_merge_options(sock, tcp_packet.option)
Tcp.tcp_send_packet(sock, remote_info, local_info, ['syn', 'ack'], option=sock.option_bin)
sock.state = "TCP_SYN_RECV"
return
if sock.state == "TCP_SYN_RECV":
# -> TCP_ESTABLISHED
tcp_packet.LOG("info", "TCP_SYN_RECV -> TCP_ESTABLISHED")
sock.state = "TCP_ESTABLISHED"
# enqueue acceptor
from core.sock import SockManager
local_info = sock.local_ip_addr, sock.local_port
base_sock = SockManager.lookup_unidirectional_sock(Tcp.PROT_TYPE, local_info)
base_sock.enqueue_acceptor(sock)
return
if sock.state == "TCP_SYN_SEND":
# -> TCP_ESTABLISHED
if tcp_packet.syn == 1 and tcp_packet.ack == 1:
Tcp.tcp_send_packet(sock, remote_info, local_info, ['ack'])
if sock.state in ["TCP_ESTABLISHED", "TCP_FIN_WAIT_1", "TCP_FIN_WAIT_2"]:
# recv data
if tcp_packet.psh == 1 and tcp_packet.ack == 1:
sock.enqueue_data(tcp_packet.payload)
Tcp.tcp_send_packet(sock, remote_info, local_info, ['ack'])
return
if sock.state == "TCP_FIN_WAIT_1":
if tcp_packet.ack == 1:
sock.state = "TCP_FIN_WAIT_2"
return
if sock.state == "TCP_FIN_WAIT_2":
if tcp_packet.fin == 1:
Tcp.tcp_send_packet(sock, remote_info, local_info, ['ack'])
sock.state = "TCP_TIME_WAIT"
return