Fixed link packet routing in topologies where transport packets leak to non-intended instances in the link chain

This commit is contained in:
Mark Qvist 2024-05-04 19:52:02 +02:00
parent 15e10b9435
commit 8330f70a27

View File

@ -973,6 +973,13 @@ class Transport:
# TODO: Think long and hard about this. # TODO: Think long and hard about this.
# Is it even strictly necessary with the current # Is it even strictly necessary with the current
# transport rules? # transport rules?
# Filter packets intended for other transport instances
if packet.transport_id != None and packet.packet_type != RNS.Packet.ANNOUNCE:
if packet.transport_id != Transport.identity.hash:
RNS.log("Ignored packet "+RNS.prettyhexrep(packet.packet_hash)+" in transport for other transport instance", RNS.LOG_EXTREME)
return False
if packet.context == RNS.Packet.KEEPALIVE: if packet.context == RNS.Packet.KEEPALIVE:
return True return True
if packet.context == RNS.Packet.RESOURCE_REQ: if packet.context == RNS.Packet.RESOURCE_REQ:
@ -1137,10 +1144,31 @@ class Transport:
elif Transport.interface_to_shared_instance(interface): elif Transport.interface_to_shared_instance(interface):
packet.hops -= 1 packet.hops -= 1
if Transport.packet_filter(packet): if Transport.packet_filter(packet):
# By default, remember packet hashes to avoid routing
# loops in the network, using the packet filter.
remember_packet_hash = True
# If this packet belongs to a link in our link table,
# we'll have to defer adding it to the filter list.
# In some cases, we might see a packet over a shared-
# medium interface, belonging to a link that transports
# or terminates with this instance, but before it would
# normally reach us. If the packet is appended to the
# filter list at this point, link transport will break.
if packet.destination_hash in Transport.link_table:
remember_packet_hash = False
# If this is a link request proof, don't add it until
# we are sure it's not actually somewhere else in the
# routing chain.
if packet.packet_type == RNS.Packet.PROOF and packet.context == RNS.Packet.LRPROOF:
remember_packet_hash = False
if remember_packet_hash:
Transport.packet_hashlist.append(packet.packet_hash) Transport.packet_hashlist.append(packet.packet_hash)
Transport.cache(packet) # TODO: Enable when caching has been redesigned
# Transport.cache(packet)
# Check special conditions for local clients connected # Check special conditions for local clients connected
# through a shared Reticulum instance # through a shared Reticulum instance
@ -1261,7 +1289,7 @@ class Transport:
link_entry = Transport.link_table[packet.destination_hash] link_entry = Transport.link_table[packet.destination_hash]
# If receiving and outbound interface is # If receiving and outbound interface is
# the same for this link, direction doesn't # the same for this link, direction doesn't
# matter, and we simply send the packet on. # matter, and we simply repeat the packet.
outbound_interface = None outbound_interface = None
if link_entry[2] == link_entry[4]: if link_entry[2] == link_entry[4]:
# But check that taken hops matches one # But check that taken hops matches one
@ -1282,6 +1310,11 @@ class Transport:
outbound_interface = link_entry[2] outbound_interface = link_entry[2]
if outbound_interface != None: if outbound_interface != None:
# Add this packet to the filter hashlist if we
# have determined that it's actually our turn
# to process it.
Transport.packet_hashlist.append(packet.packet_hash)
new_raw = packet.raw[0:1] new_raw = packet.raw[0:1]
new_raw += struct.pack("!B", packet.hops) new_raw += struct.pack("!B", packet.hops)
new_raw += packet.raw[2:] new_raw += packet.raw[2:]
@ -1713,6 +1746,11 @@ class Transport:
# pending link # pending link
for link in Transport.pending_links: for link in Transport.pending_links:
if link.link_id == packet.destination_hash: if link.link_id == packet.destination_hash:
if packet.hops == link.expected_hops:
# Add this packet to the filter hashlist if we
# have determined that it's actually destined
# for this system, and then validate the proof
Transport.packet_hashlist.append(packet.packet_hash)
link.validate_proof(packet) link.validate_proof(packet)
elif packet.context == RNS.Packet.RESOURCE_PRF: elif packet.context == RNS.Packet.RESOURCE_PRF: