core-lightning/contrib/pyln-client/pyln/client/gossmap.py
Alex Myers 9dc794dba8 gossipd: make use of new ratelimit bit in gossip_store length mask
routing.c now flags rate-limited gossip as it enters the gossip_store but
makes use of it in updating the routing graph. Flagged gossip is not
rebroadcast to gossip peers.

Changelog-Changed: gossipd: now accepts spam gossip, but squelches it for
peers.
2022-07-06 14:31:19 +09:30

315 lines
12 KiB
Python
Executable File

#! /usr/bin/python3
from pyln.spec.bolt7 import (channel_announcement, channel_update,
node_announcement)
from pyln.proto import ShortChannelId, PublicKey
from typing import Any, Dict, List, Optional, Union, cast
import io
import struct
# These duplicate constants in lightning/common/gossip_store.h
GOSSIP_STORE_VERSIONS = [0x09, 0x0a]
GOSSIP_STORE_LEN_DELETED_BIT = 0x80000000
GOSSIP_STORE_LEN_PUSH_BIT = 0x40000000
GOSSIP_STORE_LEN_RATELIMIT_BIT = 0x20000000
GOSSIP_STORE_LEN_MASK = (~(GOSSIP_STORE_LEN_PUSH_BIT
| GOSSIP_STORE_LEN_DELETED_BIT
| GOSSIP_STORE_LEN_RATELIMIT_BIT))
# These duplicate constants in lightning/gossipd/gossip_store_wiregen.h
WIRE_GOSSIP_STORE_PRIVATE_CHANNEL = 4104
WIRE_GOSSIP_STORE_PRIVATE_UPDATE = 4102
WIRE_GOSSIP_STORE_DELETE_CHAN = 4103
WIRE_GOSSIP_STORE_ENDED = 4105
WIRE_GOSSIP_STORE_CHANNEL_AMOUNT = 4101
class GossipStoreHeader(object):
def __init__(self, buf: bytes):
length, self.crc, self.timestamp = struct.unpack('>III', buf)
self.deleted = (length & GOSSIP_STORE_LEN_DELETED_BIT) != 0
self.length = (length & GOSSIP_STORE_LEN_MASK)
class GossmapHalfchannel(object):
"""One direction of a GossmapChannel."""
def __init__(self, channel: 'GossmapChannel', direction: int,
timestamp: int, cltv_expiry_delta: int,
htlc_minimum_msat: int, htlc_maximum_msat: int,
fee_base_msat: int, fee_proportional_millionths: int):
self.channel = channel
self.direction = direction
self.source = channel.node1 if direction == 0 else channel.node2
self.destination = channel.node2 if direction == 0 else channel.node1
self.timestamp: int = timestamp
self.cltv_expiry_delta: int = cltv_expiry_delta
self.htlc_minimum_msat: int = htlc_minimum_msat
self.htlc_maximum_msat: Optional[int] = htlc_maximum_msat
self.fee_base_msat: int = fee_base_msat
self.fee_proportional_millionths: int = fee_proportional_millionths
def __repr__(self):
return "GossmapHalfchannel[{}x{}]".format(str(self.channel.scid), self.direction)
class GossmapNodeId(object):
def __init__(self, buf: Union[bytes, str]):
if isinstance(buf, str):
buf = bytes.fromhex(buf)
if len(buf) != 33 or (buf[0] != 2 and buf[0] != 3):
raise ValueError("{} is not a valid node_id".format(buf.hex()))
self.nodeid = buf
def to_pubkey(self) -> PublicKey:
return PublicKey(self.nodeid)
def __eq__(self, other):
if not isinstance(other, GossmapNodeId):
return False
return self.nodeid.__eq__(other.nodeid)
def __lt__(self, other):
if not isinstance(other, GossmapNodeId):
raise ValueError(f"Cannot compare GossmapNodeId with {type(other)}")
return self.nodeid.__lt__(other.nodeid) # yes, that works
def __hash__(self):
return self.nodeid.__hash__()
def __repr__(self):
return "GossmapNodeId[{}]".format(self.nodeid.hex())
@classmethod
def from_str(cls, s: str):
if s.startswith('0x'):
s = s[2:]
if len(s) != 66:
raise ValueError(f"{s} is not a valid hexstring of a node_id")
return cls(bytes.fromhex(s))
class GossmapChannel(object):
"""A channel: fields of channel_announcement are in .fields, optional updates are in .updates_fields, which can be None if there has been no channel update."""
def __init__(self,
fields: Dict[str, Any],
announce_offset: int,
scid,
node1: 'GossmapNode',
node2: 'GossmapNode',
is_private: bool):
self.fields = fields
self.announce_offset = announce_offset
self.is_private = is_private
self.scid = scid
self.node1 = node1
self.node2 = node2
self.updates_fields: List[Optional[Dict[str, Any]]] = [None, None]
self.updates_offset: List[Optional[int]] = [None, None]
self.satoshis = None
self.half_channels: List[Optional[GossmapHalfchannel]] = [None, None]
def _update_channel(self,
direction: int,
fields: Dict[str, Any],
off: int):
self.updates_fields[direction] = fields
self.updates_offset[direction] = off
half = GossmapHalfchannel(self, direction,
fields['timestamp'],
fields['cltv_expiry_delta'],
fields['htlc_minimum_msat'],
fields.get('htlc_maximum_msat', None),
fields['fee_base_msat'],
fields['fee_proportional_millionths'])
self.half_channels[direction] = half
def get_direction(self, direction: int):
""" returns the GossmapHalfchannel if known by channel_update """
if not 0 <= direction <= 1:
raise ValueError("direction can only be 0 or 1")
return self.half_channels[direction]
def __repr__(self):
return "GossmapChannel[{}]".format(str(self.scid))
class GossmapNode(object):
"""A node: fields of node_announcement are in .announce_fields, which can be None of there has been no node announcement.
.channels is a list of the GossmapChannels attached to this node.
"""
def __init__(self, node_id: Union[GossmapNodeId, bytes, str]):
if isinstance(node_id, bytes) or isinstance(node_id, str):
node_id = GossmapNodeId(node_id)
self.announce_fields: Optional[Dict[str, Any]] = None
self.announce_offset: Optional[int] = None
self.channels: List[GossmapChannel] = []
self.node_id = node_id
def __repr__(self):
return "GossmapNode[{}]".format(self.node_id.nodeid.hex())
def __eq__(self, other):
if not isinstance(other, GossmapNode):
return False
return self.node_id.__eq__(other.node_id)
def __lt__(self, other):
if not isinstance(other, GossmapNode):
raise ValueError(f"Cannot compare GossmapNode with {type(other)}")
return self.node_id.__lt__(other.node_id)
class Gossmap(object):
"""Class to represent the gossip map of the network"""
def __init__(self, store_filename: str = "gossip_store"):
self.store_filename = store_filename
self.store_file = open(store_filename, "rb")
self.store_buf = bytes()
self.nodes: Dict[GossmapNodeId, GossmapNode] = {}
self.channels: Dict[ShortChannelId, GossmapChannel] = {}
self._last_scid: Optional[str] = None
version = self.store_file.read(1)[0]
if version not in GOSSIP_STORE_VERSIONS:
raise ValueError("Invalid gossip store version {}".format(version))
self.bytes_read = 1
self.refresh()
def _new_channel(self,
fields: Dict[str, Any],
announce_offset: int,
scid: ShortChannelId,
node1: GossmapNode,
node2: GossmapNode,
is_private: bool):
c = GossmapChannel(fields, announce_offset,
scid, node1, node2,
is_private)
self._last_scid = scid
self.channels[scid] = c
node1.channels.append(c)
node2.channels.append(c)
def _del_channel(self, scid: ShortChannelId):
c = self.channels[scid]
del self.channels[scid]
c.node1.channels.remove(c)
c.node2.channels.remove(c)
# Beware self-channels n1-n1!
if len(c.node1.channels) == 0 and c.node1 != c.node2:
del self.nodes[c.node1.node_id]
if len(c.node2.channels) == 0:
del self.nodes[c.node2.node_id]
def _add_channel(self, rec: bytes, off: int, is_private: bool):
fields = channel_announcement.read(io.BytesIO(rec[2:]), {})
# Add nodes one the fly
node1_id = GossmapNodeId(fields['node_id_1'])
node2_id = GossmapNodeId(fields['node_id_2'])
if node1_id not in self.nodes:
self.nodes[node1_id] = GossmapNode(node1_id)
if node2_id not in self.nodes:
self.nodes[node2_id] = GossmapNode(node2_id)
self._new_channel(fields, off,
ShortChannelId.from_int(fields['short_channel_id']),
self.get_node(node1_id), self.get_node(node2_id),
is_private)
def _set_channel_amount(self, rec: bytes):
""" Sets channel capacity of last added channel """
sats, = struct.unpack(">Q", rec[2:])
self.channels[self._last_scid].satoshis = sats
def get_channel(self, short_channel_id: ShortChannelId):
""" Resolves a channel by its short channel id """
if isinstance(short_channel_id, str):
short_channel_id = ShortChannelId.from_str(short_channel_id)
return self.channels.get(short_channel_id)
def get_node(self, node_id: Union[GossmapNodeId, str]):
""" Resolves a node by its public key node_id """
if isinstance(node_id, str):
node_id = GossmapNodeId.from_str(node_id)
return self.nodes.get(cast(GossmapNodeId, node_id))
def _update_channel(self, rec: bytes, off: int):
fields = channel_update.read(io.BytesIO(rec[2:]), {})
direction = fields['channel_flags'] & 1
c = self.channels[ShortChannelId.from_int(fields['short_channel_id'])]
c._update_channel(direction, fields, off)
def _add_node_announcement(self, rec: bytes, off: int):
fields = node_announcement.read(io.BytesIO(rec[2:]), {})
node_id = GossmapNodeId(fields['node_id'])
self.nodes[node_id].announce_fields = fields
self.nodes[node_id].announce_offset = off
def reopen_store(self):
"""FIXME: Implement!"""
assert False
def _remove_channel_by_deletemsg(self, rec: bytes):
scidint, = struct.unpack(">Q", rec[2:])
scid = ShortChannelId.from_int(scidint)
# It might have already been deleted when we skipped it.
if scid in self.channels:
self._del_channel(scid)
def _pull_bytes(self, length: int) -> bool:
"""Pull bytes from file into our internal buffer"""
if len(self.store_buf) < length:
self.store_buf += self.store_file.read(length
- len(self.store_buf))
return len(self.store_buf) >= length
def _read_record(self) -> Optional[bytes]:
"""If a whole record is not in the file, returns None.
If deleted, returns empty."""
if not self._pull_bytes(12):
return None
hdr = GossipStoreHeader(self.store_buf[:12])
if not self._pull_bytes(12 + hdr.length):
return None
self.bytes_read += len(self.store_buf)
ret = self.store_buf[12:]
self.store_buf = bytes()
if hdr.deleted:
ret = bytes()
return ret
def refresh(self):
"""Catch up with any changes to the gossip store"""
while True:
off = self.bytes_read
rec = self._read_record()
# EOF?
if rec is None:
break
# Deleted?
if len(rec) == 0:
continue
rectype, = struct.unpack(">H", rec[:2])
if rectype == channel_announcement.number:
self._add_channel(rec, off, False)
elif rectype == WIRE_GOSSIP_STORE_PRIVATE_CHANNEL:
self._add_channel(rec[2 + 8 + 2:], off + 2 + 8 + 2, True)
elif rectype == WIRE_GOSSIP_STORE_CHANNEL_AMOUNT:
self._set_channel_amount(rec)
elif rectype == channel_update.number:
self._update_channel(rec, off)
elif rectype == WIRE_GOSSIP_STORE_PRIVATE_UPDATE:
self._update_channel(rec[2 + 2:], off + 2 + 2)
elif rectype == WIRE_GOSSIP_STORE_DELETE_CHAN:
self._remove_channel_by_deletemsg(rec)
elif rectype == node_announcement.number:
self._add_node_announcement(rec, off)
elif rectype == WIRE_GOSSIP_STORE_ENDED:
self.reopen_store()
else:
continue