URI: 
       tlightning channels reserves: use pretty balance in Qt, fix bugs, add tests - electrum - Electrum Bitcoin wallet
  HTML git clone https://git.parazyd.org/electrum
   DIR Log
   DIR Files
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   DIR Submodules
       ---
   DIR commit a5a7c1406e02f899a62a544eaef8e771d2aa472a
   DIR parent eb4e6b2e54a091a729f5cdef6e7116de4ea1500b
  HTML Author: Janus <ysangkok@gmail.com>
       Date:   Wed, 24 Oct 2018 20:39:07 +0200
       
       lightning channels reserves: use pretty balance in Qt, fix bugs, add tests
       
       Diffstat:
         M electrum/gui/qt/channels_list.py    |      10 +++++-----
         M electrum/lnbase.py                  |      18 ++++++++++++++----
         M electrum/lnchan.py                  |      34 ++++++++++++++++++++++++++-----
         M electrum/tests/test_lnchan.py       |     126 ++++++++++++++++++++++++++++---
       
       4 files changed, 162 insertions(+), 26 deletions(-)
       ---
   DIR diff --git a/electrum/gui/qt/channels_list.py b/electrum/gui/qt/channels_list.py
       t@@ -25,12 +25,12 @@ class ChannelsList(MyTreeWidget):
            def format_fields(self, chan):
                labels = {}
                for subject in (REMOTE, LOCAL):
       -            available = chan.available_to_spend(subject)//1000
       -            label = self.parent.format_amount(available)
       +            bal_minus_htlcs = chan.balance_minus_outgoing_htlcs(subject)//1000
       +            label = self.parent.format_amount(bal_minus_htlcs)
                    bal_other = chan.balance(-subject)//1000
       -            available_other = chan.available_to_spend(-subject)//1000
       -            if bal_other != available_other:
       -                label += ' (+' + self.parent.format_amount(bal_other - available_other) + ')'
       +            bal_minus_htlcs_other = chan.balance_minus_outgoing_htlcs(-subject)//1000
       +            if bal_other != bal_minus_htlcs_other:
       +                label += ' (+' + self.parent.format_amount(bal_other - bal_minus_htlcs_other) + ')'
                    labels[subject] = label
                return [
                    bh2u(chan.node_id),
   DIR diff --git a/electrum/lnbase.py b/electrum/lnbase.py
       t@@ -427,7 +427,7 @@ class Peer(PrintError):
                    to_self_delay=local_config.to_self_delay,
                    max_htlc_value_in_flight_msat=local_config.max_htlc_value_in_flight_msat,
                    channel_flags=0x00,  # not willing to announce channel
       -            channel_reserve_satoshis=546
       +            channel_reserve_satoshis=local_config.reserve_sat,
                )
                payload = await self.channel_accepted[temp_channel_id].get()
                if payload.get('error'):
       t@@ -440,6 +440,7 @@ class Peer(PrintError):
                remote_max = int.from_bytes(payload['max_htlc_value_in_flight_msat'], 'big')
                assert remote_max >= 198 * 1000 * 1000, remote_max
                their_revocation_store = RevocationStore()
       +        remote_reserve_sat = self.validate_remote_reserve(payload["channel_reserve_satoshis"], remote_dust_limit_sat, funding_sat)
                remote_config = RemoteConfig(
                    payment_basepoint=OnlyPubkeyKeypair(payload['payment_basepoint']),
                    multisig_key=OnlyPubkeyKeypair(payload["funding_pubkey"]),
       t@@ -454,7 +455,7 @@ class Peer(PrintError):
                    ctn = -1,
                    amount_msat=push_msat,
                    next_htlc_id = 0,
       -            reserve_sat = int.from_bytes(payload["channel_reserve_satoshis"], 'big'),
       +            reserve_sat = remote_reserve_sat,
        
                    next_per_commitment_point=remote_per_commitment_point,
                    current_per_commitment_point=None,
       t@@ -528,7 +529,7 @@ class Peer(PrintError):
                    temporary_channel_id=temp_chan_id,
                    dust_limit_satoshis=local_config.dust_limit_sat,
                    max_htlc_value_in_flight_msat=local_config.max_htlc_value_in_flight_msat,
       -            channel_reserve_satoshis=546,
       +            channel_reserve_satoshis=local_config.reserve_sat,
                    htlc_minimum_msat=1000,
                    minimum_depth=min_depth,
                    to_self_delay=local_config.to_self_delay,
       t@@ -546,6 +547,7 @@ class Peer(PrintError):
                channel_id, funding_txid_bytes = channel_id_from_funding_tx(funding_txid, funding_idx)
                their_revocation_store = RevocationStore()
                remote_balance_sat = funding_sat * 1000 - push_msat
       +        remote_reserve_sat = self.validate_remote_reserve(payload['channel_reserve_satoshis'], remote_dust_limit_sat, funding_sat)
                chan = {
                        "node_id": self.peer_addr.pubkey,
                        "channel_id": channel_id,
       t@@ -565,7 +567,7 @@ class Peer(PrintError):
                            ctn = -1,
                            amount_msat=remote_balance_sat,
                            next_htlc_id = 0,
       -                    reserve_sat = int.from_bytes(payload['channel_reserve_satoshis'], 'big'),
       +                    reserve_sat = remote_reserve_sat,
        
                            next_per_commitment_point=payload['first_per_commitment_point'],
                            current_per_commitment_point=None,
       t@@ -614,6 +616,14 @@ class Peer(PrintError):
                    m.set_state('DISCONNECTED')
                    raise Exception('funding outpoint mismatch')
        
       +    def validate_remote_reserve(self, payload_field, dust_limit, funding_sat):
       +        remote_reserve_sat = int.from_bytes(payload_field, 'big')
       +        if remote_reserve_sat < dust_limit:
       +            raise Exception('protocol violation: reserve < dust_limit')
       +        if remote_reserve_sat > funding_sat/100:
       +            raise Exception(f'reserve too high: {remote_reserve_sat}, funding_sat: {funding_sat}')
       +        return remote_reserve_sat
       +
            @log_exceptions
            async def reestablish_channel(self, chan):
                await self.initialized
   DIR diff --git a/electrum/lnchan.py b/electrum/lnchan.py
       t@@ -164,7 +164,7 @@ class Channel(PrintError):
                if self.get_state() != 'OPEN':
                    raise PaymentFailure('Channel not open')
                if self.available_to_spend(LOCAL) < amount_msat:
       -            raise PaymentFailure('Not enough local balance')
       +            raise PaymentFailure(f'Not enough local balance. Have: {self.available_to_spend(LOCAL)}, Need: {amount_msat}')
                if len(self.htlcs(LOCAL, only_pending=True)) + 1 > self.config[REMOTE].max_accepted_htlcs:
                    raise PaymentFailure('Too many HTLCs already in channel')
                current_htlc_sum = htlcsum(self.htlcs(LOCAL, only_pending=True))
       t@@ -213,7 +213,9 @@ class Channel(PrintError):
                assert type(htlc) is dict
                htlc = UpdateAddHtlc(**htlc, htlc_id = self.config[REMOTE].next_htlc_id)
                if self.available_to_spend(REMOTE) < htlc.amount_msat:
       -            raise RemoteMisbehaving('Remote dipped below channel reserve')
       +            raise RemoteMisbehaving('Remote dipped below channel reserve.' +\
       +                    f' Available at remote: {self.available_to_spend(REMOTE)},' +\
       +                    f' HTLC amount: {htlc.amount_msat}')
                adds = self.log[REMOTE]['adds']
                adds[htlc.htlc_id] = htlc
                self.print_error("receive_htlc")
       t@@ -481,6 +483,16 @@ class Channel(PrintError):
                return received_this_batch, sent_this_batch
        
            def balance(self, subject):
       +        """
       +        This balance in mSAT is not including reserve and fees.
       +        So a node cannot actually use it's whole balance.
       +        But this number is simple, since it is derived simply
       +        from the initial balance, and the value of settled HTLCs.
       +        Note that it does not decrease once an HTLC is added,
       +        failed or fulfilled, since the balance change is only
       +        commited to later when the respective commitment
       +        transaction as been revoked.
       +        """
                initial = self.config[subject].initial_msat
        
                initial -= sum(self.settled[subject])
       t@@ -489,15 +501,27 @@ class Channel(PrintError):
                assert initial == self.config[subject].amount_msat
                return initial
        
       -    def available_to_spend(self, subject):
       +    def balance_minus_outgoing_htlcs(self, subject):
       +        """
       +        This balance in mSAT, which includes the value of
       +        pending outgoing HTLCs, is used in the UI.
       +        """
                return self.balance(subject)\
       +                - htlcsum(self.log[subject]['adds'].values())
       +
       +    def available_to_spend(self, subject):
       +        """
       +        This balance in mSAT, while technically correct, can
       +        not be used in the UI cause it fluctuates (commit fee)
       +        """
       +        return self.balance_minus_outgoing_htlcs(subject)\
                        - htlcsum(self.log[subject]['adds'].values())\
       -                - self.config[subject].reserve_sat * 1000\
       +                - self.config[-subject].reserve_sat * 1000\
                        - calc_onchain_fees(
                              # TODO should we include a potential new htlc, when we are called from receive_htlc?
                              len(list(self.included_htlcs(subject, LOCAL)) + list(self.included_htlcs(subject, REMOTE))),
                              self.pending_feerate(subject),
       -                      subject == LOCAL,
       +                      True, # for_us
                              self.constraints.is_initiator,
                          )[subject]
        
   DIR diff --git a/electrum/tests/test_lnchan.py b/electrum/tests/test_lnchan.py
       t@@ -151,7 +151,19 @@ class TestChannel(unittest.TestCase):
                # this htlc to his remote state update log.
                self.aliceHtlcIndex = self.alice_channel.add_htlc(self.htlc_dict)
        
       +        before = self.bob_channel.balance_minus_outgoing_htlcs(REMOTE)
       +        beforeLocal = self.bob_channel.balance_minus_outgoing_htlcs(LOCAL)
       +
                self.bobHtlcIndex = self.bob_channel.receive_htlc(self.htlc_dict)
       +
       +        after  = self.bob_channel.balance_minus_outgoing_htlcs(REMOTE)
       +        afterLocal = self.bob_channel.balance_minus_outgoing_htlcs(LOCAL)
       +
       +        self.assertEqual(before - after, self.htlc_dict['amount_msat'])
       +        self.assertEqual(beforeLocal, afterLocal)
       +
       +        self.bob_pending_remote_balance = after
       +
                self.htlc = self.bob_channel.log[lnutil.REMOTE]['adds'][0]
        
            def test_SimpleAddSettleWorkflow(self):
       t@@ -259,11 +271,28 @@ class TestChannel(unittest.TestCase):
                # revocation.
                #self.assertEqual(alice_channel.local_update_log, [], "alice's local not updated, should be empty, has %s entries instead"% len(alice_channel.local_update_log))
                #self.assertEqual(alice_channel.remote_update_log, [], "alice's remote not updated, should be empty, has %s entries instead"% len(alice_channel.remote_update_log))
       +        self.assertEqual(self.bob_pending_remote_balance, self.alice_channel.balance(LOCAL))
       +
                alice_channel.update_fee(100000)
       +        bob_channel.receive_update_fee(100000)
       +        force_state_transition(alice_channel, bob_channel)
       +
       +        self.htlc_dict['amount_msat'] *= 5
       +        bob_index = bob_channel.add_htlc(self.htlc_dict)
       +        alice_index = alice_channel.receive_htlc(self.htlc_dict)
       +        force_state_transition(alice_channel, bob_channel)
       +        alice_channel.settle_htlc(self.paymentPreimage, alice_index)
       +        bob_channel.receive_htlc_settle(self.paymentPreimage, bob_index)
       +        force_state_transition(alice_channel, bob_channel)
       +        self.assertEqual(alice_channel.total_msat(SENT), one_bitcoin_in_msat, "alice satoshis sent incorrect")
       +        self.assertEqual(alice_channel.total_msat(RECEIVED), 5 * one_bitcoin_in_msat, "alice satoshis received incorrect")
       +        self.assertEqual(bob_channel.total_msat(RECEIVED), one_bitcoin_in_msat, "bob satoshis received incorrect")
       +        self.assertEqual(bob_channel.total_msat(SENT), 5 * one_bitcoin_in_msat, "bob satoshis sent incorrect")
       +
                alice_channel.serialize()
        
       -    def alice_to_bob_fee_update(self):
       -        fee = 111
       +
       +    def alice_to_bob_fee_update(self, fee=111):
                self.alice_channel.update_fee(fee)
                self.bob_channel.receive_update_fee(fee)
                return fee
       t@@ -325,6 +354,13 @@ class TestChannel(unittest.TestCase):
                self.assertEqual(fee, bob_channel.constraints.feerate)
        
            def test_AddHTLCNegativeBalance(self):
       +        # the test in lnd doesn't set the fee to zero.
       +        # probably lnd subtracts commitment fee after deciding weather
       +        # an htlc can be added. so we set the fee to zero so that
       +        # the test can work.
       +        self.alice_to_bob_fee_update(0)
       +        force_state_transition(self.alice_channel, self.bob_channel)
       +
                self.htlc_dict['payment_hash'] = bitcoin.sha256(32 * b'\x02')
                self.alice_channel.add_htlc(self.htlc_dict)
                self.htlc_dict['payment_hash'] = bitcoin.sha256(32 * b'\x03')
       t@@ -339,7 +375,7 @@ class TestChannel(unittest.TestCase):
                new['payment_hash'] = bitcoin.sha256(32 * b'\x04')
                with self.assertRaises(lnutil.PaymentFailure) as cm:
                    self.alice_channel.add_htlc(new)
       -        self.assertEqual(('Not enough local balance',), cm.exception.args)
       +        self.assertIn('Not enough local balance', cm.exception.args[0])
        
        class TestAvailableToSpend(unittest.TestCase):
            def test_DesyncHTLCs(self):
       t@@ -381,22 +417,23 @@ class TestChanReserve(unittest.TestCase):
            def setUp(self):
                alice_channel, bob_channel = create_test_channels()
                alice_min_reserve = int(.5 * one_bitcoin_in_msat // 1000)
       -        alice_channel.config[LOCAL] =\
       -            alice_channel.config[LOCAL]._replace(reserve_sat=alice_min_reserve)
       -        bob_channel.config[REMOTE] =\
       -            bob_channel.config[REMOTE]._replace(reserve_sat=alice_min_reserve)
                # We set Bob's channel reserve to a value that is larger than
                # his current balance in the channel. This will ensure that
                # after a channel is first opened, Bob can still receive HTLCs
                # even though his balance is less than his channel reserve.
                bob_min_reserve = 6 * one_bitcoin_in_msat // 1000
       -        bob_channel.config[LOCAL] =\
       -            bob_channel.config[LOCAL]._replace(reserve_sat=bob_min_reserve)
       +        # bob min reserve was decided by alice, but applies to bob
       +
       +        alice_channel.config[LOCAL] =\
       +            alice_channel.config[LOCAL]._replace(reserve_sat=bob_min_reserve)
                alice_channel.config[REMOTE] =\
       -            alice_channel.config[REMOTE]._replace(reserve_sat=bob_min_reserve)
       +            alice_channel.config[REMOTE]._replace(reserve_sat=alice_min_reserve)
       +
       +        bob_channel.config[LOCAL] =\
       +            bob_channel.config[LOCAL]._replace(reserve_sat=alice_min_reserve)
       +        bob_channel.config[REMOTE] =\
       +            bob_channel.config[REMOTE]._replace(reserve_sat=bob_min_reserve)
        
       -        self.bob_min = bob_min_reserve
       -        self.alice_min = bob_min_reserve
                self.alice_channel = alice_channel
                self.bob_channel = bob_channel
        
       t@@ -439,6 +476,71 @@ class TestChanReserve(unittest.TestCase):
                with self.assertRaises(lnutil.RemoteMisbehaving):
                    self.alice_channel.receive_htlc(htlc_dict)
        
       +    def part2(self):
       +        paymentPreimage = b"\x01" * 32
       +        paymentHash = bitcoin.sha256(paymentPreimage)
       +        # Now we'll add HTLC of 3.5 BTC to Alice's commitment, this should put
       +        # Alice's balance at 1.5 BTC.
       +        #
       +        # Resulting balances:
       +        #        Alice:        1.5
       +        #        Bob:        9.5
       +        htlc_dict = {
       +            'payment_hash' : paymentHash,
       +            'amount_msat' :  int(3.5 * one_bitcoin_in_msat),
       +            'cltv_expiry' :  5,
       +        }
       +        self.alice_channel.add_htlc(htlc_dict)
       +        self.bob_channel.receive_htlc(htlc_dict)
       +        # Add a second HTLC of 1 BTC. This should fail because it will take
       +        # Alice's balance all the way down to her channel reserve, but since
       +        # she is the initiator the additional transaction fee makes her
       +        # balance dip below.
       +        htlc_dict['amount_msat'] = one_bitcoin_in_msat
       +        with self.assertRaises(lnutil.PaymentFailure):
       +            self.alice_channel.add_htlc(htlc_dict)
       +        with self.assertRaises(lnutil.RemoteMisbehaving):
       +            self.bob_channel.receive_htlc(htlc_dict)
       +
       +    def part3(self):
       +        # Add a HTLC of 2 BTC to Alice, and the settle it.
       +        # Resulting balances:
       +        #        Alice:        3.0
       +        #        Bob:        7.0
       +        htlc_dict = {
       +            'payment_hash' : paymentHash,
       +            'amount_msat' :  int(2 * one_bitcoin_in_msat),
       +            'cltv_expiry' :  5,
       +        }
       +        alice_idx = self.alice_channel.add_htlc(htlc_dict)
       +        bob_idx = self.bob_channel.receive_htlc(htlc_dict)
       +        force_state_transition(self.alice_channel, self.bob_channel)
       +        self.check_bals(one_bitcoin_in_msat*3\
       +                - self.alice_channel.pending_local_fee,
       +                  one_bitocin_in_msat*5)
       +        self.bob_channel.settle_htlc(paymentPreimage, bob_idx)
       +        self.alice_channel.receive_htlc_settle(paymentPreimage, alice_idx)
       +        force_state_transition(self.alice_channel, self.bob_channel)
       +        self.check_bals(one_bitcoin_in_msat*3\
       +                - self.alice_channel.pending_local_fee,
       +                  one_bitocin_in_msat*7)
       +        # And now let Bob add an HTLC of 1 BTC. This will take Bob's balance
       +        # all the way down to his channel reserve, but since he is not paying
       +        # the fee this is okay.
       +        htlc_dict['amount_msat'] = one_bitcoin_in_msat
       +        self.bob_channel.add_htlc(htlc_dict)
       +        self.alice_channel.receive_htlc(htlc_dict)
       +        force_state_transition(self.alice_channel, self.bob_channel)
       +        self.check_bals(one_bitcoin_in_msat*3\
       +                - self.alice_channel.pending_local_fee,
       +                  one_bitocin_in_msat*6)
       +
       +    def check_bals(self, amt1, amt2):
       +        self.assertEqual(self.alice_channel.available_to_spend(LOCAL), amt1)
       +        self.assertEqual(self.bob_channel.available_to_spend(REMOTE), amt1)
       +        self.assertEqual(self.alice_channel.available_to_spend(REMOTE), amt2)
       +        self.assertEqual(self.bob_channel.available_to_spend(LOCAL), amt2)
       +
        class TestDust(unittest.TestCase):
            def test_DustLimit(self):
                alice_channel, bob_channel = create_test_channels()