LNPeerAddr: validate arguments

no longer subclassing NamedTuple (as it is difficult to do validation then...)

electrum/channel_db.py

@@ -281,13 +281,19 @@ class ChannelDB(SqlDB):
             return None
         addr = sorted(list(r), key=lambda x: x[2])[0]
         host, port, timestamp = addr
-        return LNPeerAddr(host, port, node_id)
+        try:
+            return LNPeerAddr(host, port, node_id)
+        except ValueError:
+            return None
 
     def get_recent_peers(self):
         assert self.data_loaded.is_set(), "channelDB load_data did not finish yet!"
-        r = [self.get_last_good_address(x) for x in self._addresses.keys()]
-        r = r[-self.NUM_MAX_RECENT_PEERS:]
-        return r
+        # FIXME this does not reliably return "recent" peers...
+        #       Also, the list() cast over the whole dict (thousands of elements),
+        #       is really inefficient.
+        r = [self.get_last_good_address(node_id)
+             for node_id in list(self._addresses.keys())[-self.NUM_MAX_RECENT_PEERS:]]
+        return list(reversed(r))
 
     def add_channel_announcement(self, msg_payloads, trusted=True):
         if type(msg_payloads) is dict:

electrum/lntransport.py

@@ -8,11 +8,12 @@
 import hashlib
 import asyncio
 from asyncio import StreamReader, StreamWriter
+
 from Cryptodome.Cipher import ChaCha20_Poly1305
 
 from .crypto import sha256, hmac_oneshot
 from .lnutil import (get_ecdh, privkey_to_pubkey, LightningPeerConnectionClosed,
-                     HandshakeFailed)
+                     HandshakeFailed, LNPeerAddr)
 from . import ecc
 from .util import bh2u
 
@@ -86,7 +87,13 @@ def create_ephemeral_key() -> (bytes, bytes):
     privkey = ecc.ECPrivkey.generate_random_key()
     return privkey.get_secret_bytes(), privkey.get_public_key_bytes()
 
+
 class LNTransportBase:
+    reader: StreamReader
+    writer: StreamWriter
+
+    def name(self) -> str:
+        raise NotImplementedError()
 
     def send_bytes(self, msg: bytes) -> None:
         l = len(msg).to_bytes(2, 'big')
@@ -207,21 +214,18 @@ class LNResponderTransport(LNTransportBase):
 
 class LNTransport(LNTransportBase):
 
-    def __init__(self, privkey: bytes, peer_addr):
+    def __init__(self, privkey: bytes, peer_addr: LNPeerAddr):
         LNTransportBase.__init__(self)
         assert type(privkey) is bytes and len(privkey) == 32
         self.privkey = privkey
-        self.remote_pubkey = peer_addr.pubkey
-        self.host = peer_addr.host
-        self.port = peer_addr.port
         self.peer_addr = peer_addr
 
     def name(self):
-        return str(self.host) + ':' + str(self.port)
+        return self.peer_addr.net_addr_str()
 
     async def handshake(self):
-        self.reader, self.writer = await asyncio.open_connection(self.host, self.port)
-        hs = HandshakeState(self.remote_pubkey)
+        self.reader, self.writer = await asyncio.open_connection(self.peer_addr.host, self.peer_addr.port)
+        hs = HandshakeState(self.peer_addr.pubkey)
         # Get a new ephemeral key
         epriv, epub = create_ephemeral_key()
 
@@ -230,7 +234,8 @@ class LNTransport(LNTransportBase):
         self.writer.write(msg)
         rspns = await self.reader.read(2**10)
         if len(rspns) != 50:
-            raise HandshakeFailed(f"Lightning handshake act 1 response has bad length, are you sure this is the right pubkey? {bh2u(self.remote_pubkey)}")
+            raise HandshakeFailed(f"Lightning handshake act 1 response has bad length, "
+                                  f"are you sure this is the right pubkey? {self.peer_addr}")
         hver, alice_epub, tag = rspns[0], rspns[1:34], rspns[34:]
         if bytes([hver]) != hs.handshake_version:
             raise HandshakeFailed("unexpected handshake version: {}".format(hver))

electrum/lnutil.py

@@ -658,14 +658,31 @@ class LnGlobalFeatures(IntFlag):
 LN_GLOBAL_FEATURES_KNOWN_SET = set(LnGlobalFeatures)
 
 
-class LNPeerAddr(NamedTuple):
-    host: str
-    port: int
-    pubkey: bytes
+class LNPeerAddr:
+
+    def __init__(self, host: str, port: int, pubkey: bytes):
+        assert isinstance(host, str), repr(host)
+        assert isinstance(port, int), repr(port)
+        assert isinstance(pubkey, bytes), repr(pubkey)
+        try:
+            net_addr = NetAddress(host, port)  # this validates host and port
+        except Exception as e:
+            raise ValueError(f"cannot construct LNPeerAddr: invalid host or port (host={host}, port={port})") from e
+        # note: not validating pubkey as it would be too expensive:
+        # if not ECPubkey.is_pubkey_bytes(pubkey): raise ValueError()
+        self.host = host
+        self.port = port
+        self.pubkey = pubkey
+        self._net_addr_str = str(net_addr)
 
     def __str__(self):
-        host_and_port = str(NetAddress(self.host, self.port))
-        return '{}@{}'.format(self.pubkey.hex(), host_and_port)
+        return '{}@{}'.format(self.pubkey.hex(), self.net_addr_str())
+
+    def __repr__(self):
+        return f'<LNPeerAddr host={self.host} port={self.port} pubkey={self.pubkey.hex()}>'
+
+    def net_addr_str(self) -> str:
+        return self._net_addr_str
 
 
 def get_compressed_pubkey_from_bech32(bech32_pubkey: str) -> bytes:

electrum/lnworker.py

@@ -221,7 +221,10 @@ class LNWorker(Logger):
                 if not addrs:
                     continue
                 host, port, timestamp = self.choose_preferred_address(list(addrs))
-                peer = LNPeerAddr(host, port, node_id)
+                try:
+                    peer = LNPeerAddr(host, port, node_id)
+                except ValueError:
+                    continue
                 if peer in self._last_tried_peer:
                     continue
                 #self.logger.info('taking random ln peer from our channel db')
@@ -1265,6 +1268,8 @@ class LNWallet(LNWorker):
         self.network.trigger_callback('channels_updated', self.wallet)
         self.network.trigger_callback('wallet_updated', self.wallet)
 
+    @ignore_exceptions
+    @log_exceptions
     async def reestablish_peer_for_given_channel(self, chan):
         now = time.time()
         # try last good address first