Implemented link timeouts and keepalive
This commit is contained in:
Mark Qvist
parent
98a489ee11
commit
260f8bbaf1
157
RNS/Link.py
157
RNS/Link.py
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@ -4,7 +4,9 @@ from cryptography.hazmat.primitives import serialization
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from cryptography.hazmat.primitives.asymmetric import ec
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from cryptography.hazmat.primitives.kdf.hkdf import HKDF
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from cryptography.fernet import Fernet
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from time import sleep
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import vendor.umsgpack as umsgpack
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import threading
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import base64
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import time
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import RNS
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@ -24,12 +26,23 @@ class Link:
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ECPUBSIZE = 91
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BLOCKSIZE = 16
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# TODO: This should not be hardcoded,
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# but calculated from something like
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# first-hop RTT latency and distance
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PROOF_TIMEOUT = 10
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TIMEOUT_FACTOR = 4
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KEEPALIVE = 120
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PENDING = 0x00
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HANDSHAKE = 0x01
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ACTIVE = 0x02
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STALE = 0x03
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CLOSED = 0x04
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TIMEOUT = 0x01
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INITIATOR_CLOSED = 0x02
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DESTINATION_CLOSED = 0x03
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ACCEPT_NONE = 0x00
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ACCEPT_APP = 0x01
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ACCEPT_ALL = 0x02
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@ -47,6 +60,9 @@ class Link:
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link.prove()
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link.request_time = time.time()
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RNS.Transport.registerLink(link)
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link.last_inbound = time.time()
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link.start_watchdog()
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if link.owner.callbacks.link_established != None:
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link.owner.callbacks.link_established(link)
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RNS.log("Incoming link request "+str(link)+" accepted", RNS.LOG_VERBOSE)
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@ -69,6 +85,16 @@ class Link:
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self.resource_strategy = Link.ACCEPT_NONE
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self.outgoing_resources = []
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self.incoming_resources = []
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self.last_inbound = 0
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self.last_outbound = 0
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self.tx = 0
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self.rx = 0
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self.txbytes = 0
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self.rxbytes = 0
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self.proof_timeout = Link.PROOF_TIMEOUT
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self.timeout_factor = Link.TIMEOUT_FACTOR
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self.keepalive = Link.KEEPALIVE
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self.watchdog_lock = False
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self.status = Link.PENDING
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self.type = RNS.Destination.LINK
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self.owner = owner
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@ -100,6 +126,7 @@ class Link:
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self.setLinkID(self.packet)
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RNS.Transport.registerLink(self)
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self.request_time = time.time()
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self.start_watchdog()
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self.packet.send()
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RNS.log("Link request "+RNS.prettyhexrep(self.link_id)+" sent to "+str(self.destination), RNS.LOG_VERBOSE)
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@ -133,29 +160,30 @@ class Link:
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proof.send()
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def validateProof(self, packet):
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peer_pub_bytes = packet.data[:Link.ECPUBSIZE]
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signed_data = self.link_id+peer_pub_bytes
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signature = packet.data[Link.ECPUBSIZE:RNS.Identity.KEYSIZE/8+Link.ECPUBSIZE]
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if self.initiator:
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peer_pub_bytes = packet.data[:Link.ECPUBSIZE]
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signed_data = self.link_id+peer_pub_bytes
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signature = packet.data[Link.ECPUBSIZE:RNS.Identity.KEYSIZE/8+Link.ECPUBSIZE]
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if self.destination.identity.validate(signature, signed_data):
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self.loadPeer(peer_pub_bytes)
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self.handshake()
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self.rtt = time.time() - self.request_time
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self.attached_interface = packet.receiving_interface
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RNS.Transport.activateLink(self)
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RNS.log("Link "+str(self)+" established with "+str(self.destination)+", RTT is "+str(self.rtt), RNS.LOG_VERBOSE)
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rtt_data = umsgpack.packb(self.rtt)
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rtt_packet = RNS.Packet(self, rtt_data, context=RNS.Packet.LRRTT)
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rtt_packet.send()
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if self.destination.identity.validate(signature, signed_data):
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self.loadPeer(peer_pub_bytes)
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self.handshake()
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self.rtt = time.time() - self.request_time
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self.attached_interface = packet.receiving_interface
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RNS.Transport.activateLink(self)
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RNS.log("Link "+str(self)+" established with "+str(self.destination)+", RTT is "+str(self.rtt), RNS.LOG_VERBOSE)
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rtt_data = umsgpack.packb(self.rtt)
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rtt_packet = RNS.Packet(self, rtt_data, context=RNS.Packet.LRRTT)
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rtt_packet.send()
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self.status = Link.ACTIVE
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if self.callbacks.link_established != None:
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self.callbacks.link_established(self)
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else:
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RNS.log("Invalid link proof signature received by "+str(self), RNS.LOG_VERBOSE)
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# TODO: should we really do this, or just wait
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# for a valid one? Needs analysis.
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self.teardown()
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self.status = Link.ACTIVE
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if self.callbacks.link_established != None:
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self.callbacks.link_established(self)
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else:
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RNS.log("Invalid link proof signature received by "+str(self), RNS.LOG_VERBOSE)
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# TODO: should we really do this, or just wait
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# for a valid one? Needs analysis.
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self.teardown()
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def rtt_packet(self, packet):
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@ -168,7 +196,6 @@ class Link:
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measured_rtt = time.time() - self.request_time
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plaintext = self.decrypt(packet.data)
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rtt = umsgpack.unpackb(plaintext)
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#RNS.log("Measured RTT is "+str(measured_rtt)+", received RTT is "+str(rtt))
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self.rtt = max(measured_rtt, rtt)
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self.status = Link.ACTIVE
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except Exception as e:
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@ -185,6 +212,10 @@ class Link:
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teardown_packet = RNS.Packet(self, self.link_id, context=RNS.Packet.LINKCLOSE)
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teardown_packet.send()
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self.status = Link.CLOSED
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if self.initiator:
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self.teardown_reason = Link.INITIATOR_CLOSED
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else:
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self.teardown_reason = Link.DESTINATION_CLOSED
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self.link_closed()
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def teardown_packet(self, packet):
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@ -192,6 +223,10 @@ class Link:
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plaintext = self.decrypt(packet.data)
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if plaintext == self.link_id:
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self.status = Link.CLOSED
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if self.initiator:
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self.teardown_reason = Link.DESTINATION_CLOSED
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else:
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self.teardown_reason = Link.INITIATOR_CLOSED
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self.link_closed()
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except Exception as e:
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pass
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@ -206,12 +241,80 @@ class Link:
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if self.callbacks.link_closed != None:
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self.callbacks.link_closed(self)
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def start_watchdog(self):
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thread = threading.Thread(target=self.__watchdog_job)
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thread.setDaemon(True)
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thread.start()
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def __watchdog_job(self):
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while not self.status == Link.CLOSED:
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while (self.watchdog_lock):
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sleep(max(self.rtt, 0.025))
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if not self.status == Link.CLOSED:
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# Link was initiated, but no response
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# from destination yet
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if self.status == Link.PENDING:
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next_check = self.request_time + self.proof_timeout
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sleep_time = next_check - time.time()
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if time.time() >= self.request_time + self.proof_timeout:
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RNS.log("Link establishment timed out", RNS.LOG_VERBOSE)
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self.status = Link.CLOSED
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self.teardown_reason = Link.TIMEOUT
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self.link_closed()
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sleep_time = 0.001
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elif self.status == Link.HANDSHAKE:
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next_check = self.request_time + self.proof_timeout
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sleep_time = next_check - time.time()
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if time.time() >= self.request_time + self.proof_timeout:
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RNS.log("Timeout waiting for RTT packet from link initiator", RNS.LOG_VERBOSE)
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self.status = Link.CLOSED
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self.teardown_reason = Link.TIMEOUT
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self.link_closed()
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sleep_time = 0.001
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elif self.status == Link.ACTIVE:
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if time.time() >= self.last_inbound + self.keepalive:
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sleep_time = self.rtt * self.timeout_factor
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self.status = Link.STALE
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if self.initiator:
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self.send_keepalive()
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else:
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sleep_time = (self.last_inbound + self.keepalive) - time.time()
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elif self.status == Link.STALE:
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sleep_time = 0.001
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self.status = Link.CLOSED
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self.teardown_reason = Link.TIMEOUT
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self.link_closed()
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if sleep_time == 0:
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RNS.log("Warning! Link watchdog sleep time of 0!", RNS.LOG_ERROR)
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if sleep_time == None or sleep_time < 0:
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RNS.log("Timing error! Closing Reticulum now.", RNS.LOG_CRITICAL)
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RNS.panic()
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sleep(sleep_time)
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def send_keepalive(self):
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keepalive_packet = RNS.Packet(self, chr(0xFF), context=RNS.Packet.KEEPALIVE)
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keepalive_packet.send()
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def receive(self, packet):
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if not self.status == Link.CLOSED:
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self.watchdog_lock = True
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if not self.status == Link.CLOSED and not (self.initiator and packet.context == RNS.Packet.KEEPALIVE and packet.data == chr(0xFF)):
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if packet.receiving_interface != self.attached_interface:
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RNS.log("Link-associated packet received on unexpected interface! Someone might be trying to manipulate your communication!", RNS.LOG_ERROR)
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else:
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self.last_inbound = time.time()
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self.rx += 1
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self.rxbytes += len(packet.data)
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if self.status == Link.STALE:
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self.status = Link.ACTIVE
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if packet.packet_type == RNS.Packet.DATA:
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if packet.context == RNS.Packet.NONE:
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plaintext = self.decrypt(packet.data)
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@ -259,6 +362,12 @@ class Link:
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if resource_hash == resource.hash:
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resource.cancel()
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elif packet.context == RNS.Packet.KEEPALIVE:
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if not self.initiator and packet.data == chr(0xFF):
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keepalive_packet = RNS.Packet(self, chr(0xFE), context=RNS.Packet.KEEPALIVE)
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keepalive_packet.send()
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# TODO: find the most efficient way to allow multiple
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# transfers at the same time, sending resource hash on
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# each packet is a huge overhead. Probably some kind
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@ -274,6 +383,8 @@ class Link:
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if resource_hash == resource.hash:
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resource.validateProof(packet.data)
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self.watchdog_lock = False
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def encrypt(self, plaintext):
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if self.__encryption_disabled:
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@ -29,6 +29,7 @@ class Packet:
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RESPONSE = 0x09
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COMMAND = 0x0A
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COMMAND_STAT = 0x0B
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KEEPALIVE = 0xFC
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LINKCLOSE = 0xFD
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LRRTT = 0xFE
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LRPROOF = 0xFF
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@ -98,6 +99,10 @@ class Packet:
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# A resource takes care of symmetric
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# encryption by itself
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self.ciphertext = self.data
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elif self.context == Packet.KEEPALIVE:
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# Keepalive packets contain no actual
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# data
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self.ciphertext = self.data
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else:
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# In all other cases, we encrypt the packet
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# with the destination's public key
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@ -148,6 +153,11 @@ class Packet:
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if self.destination.type == RNS.Destination.LINK:
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if self.destination.status == RNS.Link.CLOSED:
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raise IOError("Attempt to transmit over a closed link")
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else:
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self.destination.last_outbound = time.time()
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self.destination.tx += 1
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self.destination.txbytes += len(self.data)
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if not self.packed:
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self.pack()
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@ -4,6 +4,7 @@ import math
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import time
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import threading
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import vendor.umsgpack as umsgpack
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from time import sleep
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class Resource:
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@ -97,6 +97,13 @@ class Transport:
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Transport.jobs_locked = False
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return sent
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@staticmethod
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def packet_filter(packet):
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if packet.context == RNS.Packet.KEEPALIVE:
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return True
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if not packet.packet_hash in Transport.packet_hashlist:
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return True
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@staticmethod
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def inbound(raw, interface=None):
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while (Transport.jobs_running):
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@ -111,7 +118,7 @@ class Transport:
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RNS.log(str(interface)+" received packet with hash "+RNS.prettyhexrep(packet.packet_hash), RNS.LOG_DEBUG)
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if not packet.packet_hash in Transport.packet_hashlist:
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if Transport.packet_filter(packet):
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Transport.packet_hashlist.append(packet.packet_hash)
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if packet.packet_type == RNS.Packet.ANNOUNCE:
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