def IPROUTING(self, fsm, p):
"""IPROUTING state; start route discovery for `p`."""
# error messages
dropbuffer = "sendbuffer overflow"
# get IP/DSR/Option parameters
ip, dsr = p[IP], p[DSRPacket]
src, dst = ip.src, ip.dst
# has route -> resend
if self.hasroute(dst):
yield fsm.goto(self.IPSEND, ip, src, dst)
# otherwise -> start route discovery
rre = self.rrt.getentry(dst)
drop = rre.buffer(p)
kwargs = {'src':src, 'dst':dst}
kwargs['nbuffered'] = len(rre.sendbuffer)
kwargs['timeleft'] = time2msec(rre.timeleft())
self.debug("SENDBUFF", p, **kwargs)
for d in drop:
self.log_drop(d, drop=dropbuffer)
# send RREQ
yield fsm.goto(self.TXRREQ, dst)
def TXRREQ(self, fsm, target, options=[], rexmt=0):
"""TXRREQ state; create and send route request.
:param target: Target for route discovery.
:param options: Additional DSR options [default=None].
:note: This state is persistent. It will keep trying to send until
"""
# error messages
rreqerror = "[DSR]: Error getting RREQ Table entry!"
droprexmt = "max rexmt exceeded"
drophasrt = "route already exists"
# pause for jitter
jitter = random.uniform(0,1)*self.BroadcastJitter
yield hold, fsm, jitter
# check route and rexmt count
if self.hasroute(target):
self.log("RREQSTOP", target=target, rexmt=rexmt, drop=drophasrt)
rre = self.rrt.getentry(target)
while rre.sendbuffer:
p = rre.sendbuffer.pop(0)
f = FSM.launch(self.IPRECOVER, p, self.address, target)
self.rrt.delentry(target)
# signal that RREQ has finished
self.finrreq.signal(target)
yield fsm.stop() # HALT and stop sending RREQ
if (rexmt>self.rrt.MaxRequestRexmt):
self.log("RREQDROP", target=target, rexmt=rexmt, drop=droprexmt)
rre = self.rrt.getentry(target)
while rre.sendbuffer:
p = rre.sendbuffer.pop(0)
self.log_drop(p, drop=droprexmt)
self.rrt.delentry(target)
# signal that RREQ has been abandoned
self.drprreq.signal(target)
yield fsm.stop() # HALT and stop sending RREQ
# get RREQ parameters
sendrreq = self.rrt.sendrreq(target)
rre = self.rrt.getentry(target)
tleft = rre.timeleft()
# get parameters for logging
kwargs = {'rexmt':rexmt, 'nbuffered': len(rre.sendbuffer)}
kwargs['options'] = [o.tracename for o in options]
kwargs['jitter'] = time2msec(jitter)
kwargs['timeleft'] = time2msec(tleft)
# cannot send RREQ? -> RREQ is busy, drop attempt
if not sendrreq:
self.debug("RREQBUSY", target=target, **kwargs)
yield fsm.stop() # HALT and allow other RREQ to finish
# otherwise -> send RREQ
ID, ttl = rre.ID, rre.ttl
# create DSR+RREQ+options
nextheader = self.getproto(None)
dsr = DSRPacket(nextheader=nextheader)
rreq = DSROPT_RREQ(identification=ID, target=target)
dsr.options = [rreq] + [o for o in options]
# create IP+DSR
proto = self.getproto(dsr)
src, dst = self.address, self.broadcast
ip = IP(src=src, dst=dst, proto=proto, ttl=ttl)
ip.add_payload(dsr)
# send RREQ -> wait for timeout, then rexmt
self.debug("TXRREQ", ip, target=target, **kwargs)
f = FSM.launch(self.IPDELIVER, ip, dst)
# signal that RREQ has been sent to target
self.sndrreq.signal(target)
# wait for send RREQ to timeout before trying again
yield hold, fsm, tleft
yield fsm.goto(self.TXRREQ, target, options, rexmt+1)
