def onudp(self):
self.tick()
ip_header_bytes = self.udp_listener.recv(20)
if len(ip_header_bytes) >= 20:
ip_header = struct.unpack(udp_thread.ip_packet_format, ip_header_bytes)
ip_header_length = (ip_header[0] & 0xF) * 4
total_length = ip_header[2]
source = ip_header[8]
destination = ip_header[9]
if ip_header_length > 20:
self.udp_listener.recv(ip_header_length - 20) # Skip IP options and stuff
udp_packet = self.udp_listener.recv(total_length - ip_header_length)
if not helpers.islocal(socket.inet_ntoa(source)):
return
if len(udp_packet) >= 8:
udp_header = struct.unpack("!HHHH", udp_packet[:8])
source_port = udp_header[0]
destination_port = udp_header[1]
udp_content = udp_packet[8:]
debug2(
"UDP packet to %s:%d of %d bytes\n"
% (socket.inet_ntoa(destination), destination_port, len(udp_packet))
)
chan = self.openchannel(source, source_port, destination, destination_port)
self.mux.send(
chan,
ssnet.CMD_UDP_OUT,
struct.pack("!H4sH", source_port, destination, destination_port) + udp_content,
)
def _handle_diversion(divertsock, dnsport):
p, tag = divertsock.recvfrom(4096)
src, dst = _udp_unpack(p)
debug3('got diverted packet from %r to %r\n' % (src, dst))
if dst[1] == 53:
# outgoing DNS
debug3('...packet is a DNS request.\n')
_real_dns_server[0] = dst
dst = ('127.0.0.1', dnsport)
elif src[1] == dnsport:
if islocal(src[0]):
debug3('...packet is a DNS response.\n')
src = _real_dns_server[0]
else:
log('weird?! unexpected divert from %r to %r\n' % (src, dst))
assert(0)
newp = _udp_repack(p, src, dst)
divertsock.sendto(newp, tag)
def _handle_diversion(divertsock, dnsport):
p, tag = divertsock.recvfrom(4096)
src, dst = _udp_unpack(p)
debug3('got diverted packet from %r to %r\n' % (src, dst))
if dst[1] == 53:
# outgoing DNS
debug3('...packet is a DNS request.\n')
_real_dns_server[0] = dst
dst = ('127.0.0.1', dnsport)
elif src[1] == dnsport:
if islocal(src[0], divertsock.family):
debug3('...packet is a DNS response.\n')
src = _real_dns_server[0]
else:
log('weird?! unexpected divert from %r to %r\n' % (src, dst))
assert(0)
newp = _udp_repack(p, src, dst)
divertsock.sendto(newp, tag)
sock, srcip = listener.accept()
sock.close()
finally:
_extra_fd = os.open('/dev/null', os.O_RDONLY)
return
else:
raise
if method == "tproxy":
dstip = sock.getsockname()
elif method == "pf":
dstip = pf_dst(sock)
else:
dstip = original_dst(sock)
debug1('Accept TCP: %s:%r -> %s:%r.\n' %
(srcip[0], srcip[1], dstip[0], dstip[1]))
if dstip[1] == sock.getsockname()[1] and islocal(dstip[0], sock.family):
debug1("-- ignored: that's my address!\n")
sock.close()
return
chan = mux.next_channel()
if not chan:
log('warning: too many open channels. Discarded connection.\n')
sock.close()
return
mux.send(chan, ssnet.CMD_TCP_CONNECT,
'%d,%s,%s' % (sock.family, dstip[0], dstip[1]))
outwrap = MuxWrapper(mux, chan)
handlers.append(Proxy(SockWrapper(sock, sock), outwrap))
expire_connections(time.time(), mux)
os.close(_extra_fd)
try:
sock, srcip = listener.accept()
sock.close()
finally:
_extra_fd = os.open('/dev/null', os.O_RDONLY)
return
else:
raise
if method == "tproxy":
dstip = sock.getsockname()
else:
dstip = original_dst(sock)
debug1('Accept TCP: %s:%r -> %s:%r.\n' % (srcip[0], srcip[1],
dstip[0], dstip[1]))
if dstip[1] == sock.getsockname()[1] and islocal(dstip[0], sock.family):
debug1("-- ignored: that's my address!\n")
sock.close()
return
chan = mux.next_channel()
if not chan:
log('warning: too many open channels. Discarded connection.\n')
sock.close()
return
mux.send(chan, ssnet.CMD_TCP_CONNECT, '%d,%s,%s' %
(sock.family, dstip[0], dstip[1]))
outwrap = MuxWrapper(mux, chan)
handlers.append(Proxy(SockWrapper(sock, sock), outwrap))
expire_connections(time.time(), mux)
