def RESP(self, fsm):
"""RESP state; respond to received message; assume 'rxdata' happened."""
mrx = self.rxdata.param
self.rxdata.clear(), self.csbusy.clear()
meta = mrx['meta']
data = mrx['data']
# check crc - assume crc is last 32 bits of data
crcok = self.check_crc32(str(data))
if not crcok: return fsm.goto(self.RESUME)
# is data for me?
d = Dot11Data(data)
ucast = self.isforme(d)
bcast = self.isbroadcast(d)
ns = (self.IDLE,)
if self.isdata(d) and (ucast or bcast):
# forward data to upstream using sock
dummy = Dot11Data()
hlen = len(dummy)
s = data[hlen:-4]
self.sock.send(s)
fsm.debug("wrote %d bytes to socket"%(len(s) ) )
dst = TUN.eth_ntoa(s[0:6])
src = TUN.eth_ntoa(s[6:12])
(ethertype, ) = struct.unpack(">H", s[12:14])
fsm.debug("dst = %s"%(dst) )
fsm.debug("src = %s"%(src) )
fsm.debug("ethertype = %04X"%(ethertype) )
if ucast: ns = (self.TXACK, d, meta)
if crcok:
# FIXME: Need to implement this if using reciprocity!
# Log meta data if using reciprocity!!
sender = d.addr2
return fsm.goto(*ns)
def IDLE(self, fsm):
"""IDLE state; wait on `csbusy`, `txdata`, and `rxdata`."""
self.datatosend = None
self.retrycount = 0
self.cslot = None
self.toidle.set()
ns = self.IDLE
# wait on events
if fsm.waitonevents(self.txdata, self.csbusy, self.rxdata):
if self.txdata.isSet():
s = self.txdata.param
# assume frame is an Ethernet frame
dst = TUN.eth_ntoa(s[0:6])
src = TUN.eth_ntoa(s[6:12])
#src = self.addr # use local address for source
(ethertype, ) = struct.unpack(">H", s[12:14])
fsm.debug("dst = %s"%(dst) )
fsm.debug("src = %s"%(src) )
fsm.debug("ethertype = %04X"%(ethertype) )
fsm.datatosend = self.datamsg(payload=s, addr1=dst, addr2=src)
# initialize backoff/retry parameters
self.retry(count=0)
self.txdata.clear()
ns = self.BACKOFF
elif self.rxdata.isSet():
ns = self.RESP
elif self.csbusy.isSet():
ns = self.RECV
self.toidle.clear()
return fsm.goto(ns)
