LNWorker: connect to multiple peers.

save exceptions in aiosafe.
enable adding peer in GUI.

electrum/gui/qt/channels_list.py

@@ -87,7 +87,7 @@ class ChannelsList(MyTreeWidget):
         push_amt_inp.setAmount(0)
         h.addWidget(QLabel(_('Your Node ID')), 0, 0)
         h.addWidget(local_nodeid, 0, 1)
-        h.addWidget(QLabel(_('Remote Node ID')), 1, 0)
+        h.addWidget(QLabel(_('Remote Node ID or connection string')), 1, 0)
         h.addWidget(remote_nodeid, 1, 1)
         h.addWidget(QLabel('Local amount'), 2, 0)
         h.addWidget(local_amt_inp, 2, 1)
@@ -97,19 +97,43 @@ class ChannelsList(MyTreeWidget):
         vbox.addLayout(Buttons(CancelButton(d), OkButton(d)))
         if not d.exec_():
             return
-        nodeid_hex = str(remote_nodeid.text())
         local_amt = local_amt_inp.get_amount()
         push_amt = push_amt_inp.get_amount()
+        connect_contents = str(remote_nodeid.text())
+        rest = None
+        try:
+            nodeid_hex, rest = connect_contents.split("@")
+        except ValueError:
+            nodeid_hex = connect_contents
         try:
             node_id = bfh(nodeid_hex)
+            assert len(node_id) == 33
         except:
-            self.parent.show_error(_('Invalid node ID'))
+            self.parent.show_error(_('Invalid node ID, must be 33 bytes and hexadecimal'))
             return
-        if node_id not in self.parent.wallet.lnworker.peers and node_id not in self.parent.network.lightning_nodes:
-            self.parent.show_error(_('Unknown node:') + ' ' + nodeid_hex)
-            return
-        assert local_amt >= 200000
-        assert local_amt >= push_amt
+        peer = self.parent.wallet.lnworker.peers.get(node_id)
+
+        if not peer:
+            known = node_id in self.parent.network.lightning_nodes
+            if rest is not None:
+                try:
+                    host, port = rest.split(":")
+                except ValueError:
+                    self.parent.show_error(_('Connection strings must be in <node_pubkey>@<host>:<port> format'))
+            elif known:
+                node = self.network.lightning_nodes.get(node_id)
+                host, port = node['addresses'][0]
+            else:
+                self.parent.show_error(_('Unknown node:') + ' ' + nodeid_hex)
+                return
+            try:
+                int(port)
+            except:
+                self.parent.show_error(_('Port number must be decimal'))
+                return
+
+            self.parent.wallet.lnworker.add_peer(host, port, node_id)
+
         self.main_window.protect(self.open_channel, (node_id, local_amt, push_amt))
 
     def open_channel(self, *args, **kwargs):

electrum/lnbase.py

@@ -267,21 +267,24 @@ def create_ephemeral_key(privkey):
 
 
 def aiosafe(f):
+    # save exception in object.
+    # f must be a method of a PrintError instance.
+    # aiosafe calls should not be nested
     async def f2(*args, **kwargs):
+        self = args[0]
         try:
             return await f(*args, **kwargs)
-        except:
-            # if the loop isn't stopped
-            # run_forever in network.py would not return,
-            # the asyncioThread would not die,
-            # and we would block on shutdown
-            asyncio.get_event_loop().stop()
-            traceback.print_exc()
+        except BaseException as e:
+            self.print_msg("Exception in", f.__name__, ":", e.__class__.__name__, str(e))
+            self.exception = e
     return f2
 
+
+
 class Peer(PrintError):
 
     def __init__(self, lnworker, host, port, pubkey, request_initial_sync=False):
+        self.exception = None # set by aiosafe
         self.host = host
         self.port = port
         self.pubkey = pubkey
@@ -307,7 +310,7 @@ class Peer(PrintError):
         self.attempted_route = {}
 
     def diagnostic_name(self):
-        return self.host
+        return 'lnbase:' + self.host
 
     def ping_if_required(self):
         if time.time() - self.ping_time > 120:
@@ -455,7 +458,7 @@ class Peer(PrintError):
             'alias': alias,
             'addresses': addresses
         }
-        self.print_error('node announcement', binascii.hexlify(pubkey), alias, addresses)
+        #self.print_error('node announcement', binascii.hexlify(pubkey), alias, addresses)
         self.network.trigger_callback('ln_status')
 
     def on_init(self, payload):
@@ -476,8 +479,7 @@ class Peer(PrintError):
         else:
             self.announcement_signatures[channel_id].put_nowait(payload)
 
-    @aiosafe
-    async def main_loop(self):
+    async def initialize(self):
         self.reader, self.writer = await asyncio.open_connection(self.host, self.port)
         await self.handshake()
         # send init
@@ -486,6 +488,10 @@ class Peer(PrintError):
         msg = await self.read_message()
         self.process_message(msg)
         self.initialized.set_result(True)
+
+    @aiosafe
+    async def main_loop(self):
+        await asyncio.wait_for(self.initialize(), 5)
         # loop
         while True:
             self.ping_if_required()

electrum/lnrouter.py

@@ -70,7 +70,7 @@ class ChannelInfo(PrintError):
             self.policy_node1 = ChannelInfoDirectedPolicy(msg_payload)
         else:
             self.policy_node2 = ChannelInfoDirectedPolicy(msg_payload)
-        self.print_error('channel update', binascii.hexlify(self.channel_id).decode("ascii"), flags)
+        #self.print_error('channel update', binascii.hexlify(self.channel_id).decode("ascii"), flags)
 
     def get_policy_for_node(self, node_id):
         if node_id == self.node_id_1:
@@ -112,7 +112,7 @@ class ChannelDB(PrintError):
 
     def on_channel_announcement(self, msg_payload):
         short_channel_id = msg_payload['short_channel_id']
-        self.print_error('channel announcement', binascii.hexlify(short_channel_id).decode("ascii"))
+        #self.print_error('channel announcement', binascii.hexlify(short_channel_id).decode("ascii"))
         channel_info = ChannelInfo(msg_payload)
         self._id_to_channel_info[short_channel_id] = channel_info
         self._channels_for_node[channel_info.node_id_1].add(short_channel_id)

electrum/lnworker.py

@@ -5,12 +5,13 @@ import os
 from decimal import Decimal
 import threading
 from collections import defaultdict
+import random
 
 from . import constants
 from .bitcoin import sha256, COIN
 from .util import bh2u, bfh, PrintError
 from .constants import set_testnet, set_simnet
-from .lnbase import Peer, privkey_to_pubkey
+from .lnbase import Peer, privkey_to_pubkey, aiosafe
 from .lnaddr import lnencode, LnAddr, lndecode
 from .ecc import der_sig_from_sig_string
 from .transaction import Transaction
@@ -39,15 +40,13 @@ class LNWorker(PrintError):
         self.peers = {}
         self.channels = {x.channel_id: x for x in map(HTLCStateMachine, wallet.storage.get("channels", []))}
         self.invoices = wallet.storage.get('lightning_invoices', {})
-        peer_list = network.config.get('lightning_peers', node_list)
         self.channel_state = {chan.channel_id: "DISCONNECTED" for chan in self.channels.values()}
         for chan_id, chan in self.channels.items():
             self.network.lnwatcher.watch_channel(chan, self.on_channel_utxos)
-        for host, port, pubkey in peer_list:
-            self.add_peer(host, int(port), bfh(pubkey))
         # wait until we see confirmations
         self.network.register_callback(self.on_network_update, ['updated', 'verified']) # thread safe
         self.on_network_update('updated') # shortcut (don't block) if funding tx locked and verified
+        asyncio.run_coroutine_threadsafe(self.main_loop(), asyncio.get_event_loop())
 
     def channels_for_peer(self, node_id):
         assert type(node_id) is bytes
@@ -118,15 +117,9 @@ class LNWorker(PrintError):
                 conf = self.wallet.get_tx_height(chan.funding_outpoint.txid)[1]
                 peer.on_network_update(chan, conf)
 
-    async def _open_channel_coroutine(self, node_id, amount_sat, push_sat, password):
-        if node_id not in self.peers:
-            node = self.network.lightning_nodes.get(node_id)
-            if node is None:
-                return "node not found, peers available are: " + str(self.network.lightning_nodes.keys())
-            host, port = node['addresses'][0]
-            self.add_peer(host, port, node_id)
+    async def _open_channel_coroutine(self, node_id, local_amount_sat, push_sat, password):
         peer = self.peers[node_id]
-        openingchannel = await peer.channel_establishment_flow(self.wallet, self.config, password, amount_sat, push_sat * 1000, temp_channel_id=os.urandom(32))
+        openingchannel = await peer.channel_establishment_flow(self.wallet, self.config, password, local_amount_sat + push_sat, push_sat * 1000, temp_channel_id=os.urandom(32))
         self.save_channel(openingchannel)
         self.network.lnwatcher.watch_channel(openingchannel, self.on_channel_utxos)
         self.on_channels_updated()
@@ -192,3 +185,24 @@ class LNWorker(PrintError):
         tx.add_signature_to_txin(0, none_idx, bh2u(remote_sig))
         assert tx.is_complete()
         return self.network.broadcast_transaction(tx)
+
+    @aiosafe
+    async def main_loop(self):
+        peer_list = self.config.get('lightning_peers', node_list)
+        for host, port, pubkey in peer_list:
+            self.add_peer(host, int(port), bfh(pubkey))
+        while True:
+            await asyncio.sleep(1)
+            for k, peer in list(self.peers.items()):
+                if peer.exception:
+                    self.print_error("removing peer", peer.host)
+                    self.peers.pop(k)
+            if len(self.peers) > 3:
+                continue
+            node_id = random.choice(list(self.network.lightning_nodes.keys()))
+            node = self.network.lightning_nodes.get(node_id)
+            addresses = node.get('addresses')
+            if addresses:
+                host, port = addresses[0]
+                self.print_error("trying node", bh2u(node_id))
+                self.add_peer(host, port, node_id)