URI: 
       tlnworker: do not create sweep transactions before outputs can be redeemed - electrum - Electrum Bitcoin wallet
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       ---
   DIR commit 81d340b19c461fd82c729f80355f7d8afecaf178
   DIR parent 2b04cb3bc45f478c254462a9a9fa766668a7035c
  HTML Author: ThomasV <thomasv@electrum.org>
       Date:   Thu, 30 May 2019 13:17:17 +0200
       
       lnworker: do not create sweep transactions before outputs can be redeemed
       
       Diffstat:
         M electrum/lnsweep.py                 |      72 +++++++++++++------------------
         M electrum/lnworker.py                |      23 ++++++++++++++---------
         M electrum/simple_config.py           |       8 ++++++++
         M electrum/tests/regtest/regtest.sh   |       9 +++++++--
       
       4 files changed, 59 insertions(+), 53 deletions(-)
       ---
   DIR diff --git a/electrum/lnsweep.py b/electrum/lnsweep.py
       t@@ -15,7 +15,7 @@ from .lnutil import (make_commitment_output_to_remote_address, make_commitment_o
                             get_ordered_channel_configs, privkey_to_pubkey, get_per_commitment_secret_from_seed,
                             RevocationStore, extract_ctn_from_tx_and_chan, UnableToDeriveSecret, SENT, RECEIVED)
        from .transaction import Transaction, TxOutput, construct_witness
       -from .simple_config import SimpleConfig, FEERATE_FALLBACK_STATIC_FEE
       +from .simple_config import estimate_fee
        from .logging import get_logger
        
        if TYPE_CHECKING:
       t@@ -190,7 +190,7 @@ def create_sweeptxs_for_our_ctx(chan: 'Channel', ctx: Transaction,
            to_local_address = redeem_script_to_address('p2wsh', to_local_witness_script)
            output_idx = ctx.get_output_idx_from_address(to_local_address)
            if output_idx is not None:
       -        sweep_tx = create_sweeptx_ctx_to_local(
       +        sweep_tx = lambda: create_sweeptx_ctx_to_local(
                    sweep_address=sweep_address,
                    ctx=ctx,
                    output_idx=output_idx,
       t@@ -198,7 +198,8 @@ def create_sweeptxs_for_our_ctx(chan: 'Channel', ctx: Transaction,
                    privkey=our_localdelayed_privkey.get_secret_bytes(),
                    is_revocation=False,
                    to_self_delay=to_self_delay)
       -        txs[sweep_tx.prevout(0)] = sweep_tx
       +        prevout = ctx.txid() + ':%d'%output_idx
       +        txs[prevout] = ('our_ctx_to_local', to_self_delay, 0, sweep_tx)
            # HTLCs
            def create_txns_for_htlc(htlc: 'UpdateAddHtlc', is_received_htlc: bool) -> Tuple[Optional[Transaction], Optional[Transaction]]:
                if is_received_htlc:
       t@@ -217,7 +218,7 @@ def create_sweeptxs_for_our_ctx(chan: 'Channel', ctx: Transaction,
                    local_htlc_privkey=this_htlc_privkey,
                    preimage=preimage,
                    is_received_htlc=is_received_htlc)
       -        to_wallet_tx = create_sweeptx_that_spends_htlctx_that_spends_htlc_in_ctx(
       +        sweep_tx = lambda: create_sweeptx_that_spends_htlctx_that_spends_htlc_in_ctx(
                    'sweep_from_our_ctx_htlc_',
                    to_self_delay=to_self_delay,
                    htlc_tx=htlc_tx,
       t@@ -225,21 +226,17 @@ def create_sweeptxs_for_our_ctx(chan: 'Channel', ctx: Transaction,
                    sweep_address=sweep_address,
                    privkey=our_localdelayed_privkey.get_secret_bytes(),
                    is_revocation=False)
       -        return htlc_tx, to_wallet_tx
       +        # side effect
       +        txs[htlc_tx.prevout(0)] = ('first-stage-htlc', 0, htlc_tx.cltv_expiry, lambda: htlc_tx)
       +        txs[htlc_tx.txid() + ':0'] = ('second-stage-htlc', to_self_delay, 0, sweep_tx)
            # offered HTLCs, in our ctx --> "timeout"
            # received HTLCs, in our ctx --> "success"
            offered_htlcs = chan.included_htlcs(LOCAL, SENT, ctn)  # type: List[UpdateAddHtlc]
            received_htlcs = chan.included_htlcs(LOCAL, RECEIVED, ctn)  # type: List[UpdateAddHtlc]
            for htlc in offered_htlcs:
       -        htlc_tx, to_wallet_tx = create_txns_for_htlc(htlc, is_received_htlc=False)
       -        if htlc_tx and to_wallet_tx:
       -            txs[to_wallet_tx.prevout(0)] = to_wallet_tx
       -            txs[htlc_tx.prevout(0)] = htlc_tx
       +        create_txns_for_htlc(htlc, is_received_htlc=False)
            for htlc in received_htlcs:
       -        htlc_tx, to_wallet_tx = create_txns_for_htlc(htlc, is_received_htlc=True)
       -        if htlc_tx and to_wallet_tx:
       -            txs[to_wallet_tx.prevout(0)] = to_wallet_tx
       -            txs[htlc_tx.prevout(0)] = htlc_tx
       +        create_txns_for_htlc(htlc, is_received_htlc=True)
            return txs
        
        
       t@@ -286,12 +283,13 @@ def create_sweeptxs_for_their_ctx(chan: 'Channel', ctx: Transaction,
            to_remote_address = make_commitment_output_to_remote_address(our_payment_pubkey)
            output_idx = ctx.get_output_idx_from_address(to_remote_address)
            if output_idx is not None:
       -        sweep_tx = create_sweeptx_their_ctx_to_remote(
       +        prevout = ctx.txid() + ':%d'%output_idx
       +        sweep_tx = lambda: create_sweeptx_their_ctx_to_remote(
                    sweep_address=sweep_address,
                    ctx=ctx,
                    output_idx=output_idx,
                    our_payment_privkey=other_payment_privkey)
       -        txs[sweep_tx.prevout(0)] = sweep_tx
       +        txs[prevout] = ('their_ctx_to_remote', 0, 0, sweep_tx)
            # HTLCs
            def create_sweeptx_for_htlc(htlc: 'UpdateAddHtlc', is_received_htlc: bool) -> Optional[Transaction]:
                if not is_received_htlc and not is_revocation:
       t@@ -314,7 +312,9 @@ def create_sweeptxs_for_their_ctx(chan: 'Channel', ctx: Transaction,
                # also: https://github.com/lightningnetwork/lightning-rfc/issues/448
                output_idx = ctx.get_output_idx_from_address(htlc_address)
                if output_idx is not None:
       -            sweep_tx = create_sweeptx_their_ctx_htlc(
       +            cltv_expiry = htlc.cltv_expiry if is_received_htlc and not is_revocation else 0
       +            prevout = ctx.txid() + ':%d'%output_idx
       +            sweep_tx = lambda: create_sweeptx_their_ctx_htlc(
                        ctx=ctx,
                        witness_script=htlc_output_witness_script,
                        sweep_address=sweep_address,
       t@@ -322,20 +322,17 @@ def create_sweeptxs_for_their_ctx(chan: 'Channel', ctx: Transaction,
                        output_idx=output_idx,
                        privkey=other_revocation_privkey if is_revocation else other_htlc_privkey.get_secret_bytes(),
                        is_revocation=is_revocation,
       -                cltv_expiry=htlc.cltv_expiry if is_received_htlc and not is_revocation else 0)
       -            return sweep_tx
       +                cltv_expiry=cltv_expiry)
       +            name = f'their_ctx_sweep_htlc_{ctx.txid()[:8]}_{output_idx}'
       +            txs[prevout] = (name, 0, cltv_expiry, sweep_tx)
            # received HTLCs, in their ctx --> "timeout"
            received_htlcs = chan.included_htlcs(REMOTE, RECEIVED, ctn=ctn)  # type: List[UpdateAddHtlc]
            for htlc in received_htlcs:
       -        sweep_tx = create_sweeptx_for_htlc(htlc, is_received_htlc=True)
       -        if sweep_tx:
       -            txs[sweep_tx.prevout(0)] = sweep_tx
       +        create_sweeptx_for_htlc(htlc, is_received_htlc=True)
            # offered HTLCs, in their ctx --> "success"
            offered_htlcs = chan.included_htlcs(REMOTE, SENT, ctn=ctn)  # type: List[UpdateAddHtlc]
            for htlc in offered_htlcs:
       -        sweep_tx = create_sweeptx_for_htlc(htlc, is_received_htlc=False)
       -        if sweep_tx:
       -            txs[sweep_tx.prevout(0)] = sweep_tx
       +        create_sweeptx_for_htlc(htlc, is_received_htlc=False)
            return txs
        
        
       t@@ -363,8 +360,8 @@ def create_htlctx_that_spends_from_our_ctx(chan: 'Channel', our_pcp: bytes,
        
        def create_sweeptx_their_ctx_htlc(ctx: Transaction, witness_script: bytes, sweep_address: str,
                                          preimage: Optional[bytes], output_idx: int,
       -                                  privkey: bytes, is_revocation: bool, cltv_expiry: int,
       -                                  fee_per_kb: int=None) -> Optional[Transaction]:
       +                                  privkey: bytes, is_revocation: bool,
       +                                  cltv_expiry: int) -> Optional[Transaction]:
            assert type(cltv_expiry) is int
            preimage = preimage or b''  # preimage is required iff (not is_revocation and htlc is offered)
            val = ctx.outputs()[output_idx].value
       t@@ -380,8 +377,7 @@ def create_sweeptx_their_ctx_htlc(ctx: Transaction, witness_script: bytes, sweep
                'preimage_script': bh2u(witness_script),
            }]
            tx_size_bytes = 200  # TODO (depends on offered/received and is_revocation)
       -    if fee_per_kb is None: fee_per_kb = FEERATE_FALLBACK_STATIC_FEE
       -    fee = SimpleConfig.estimate_fee_for_feerate(fee_per_kb, tx_size_bytes)
       +    fee = estimate_fee(tx_size_bytes)
            outvalue = val - fee
            if outvalue <= dust_threshold(): return None
            sweep_outputs = [TxOutput(TYPE_ADDRESS, sweep_address, outvalue)]
       t@@ -389,7 +385,6 @@ def create_sweeptx_their_ctx_htlc(ctx: Transaction, witness_script: bytes, sweep
                    , name=f'their_ctx_sweep_htlc_{ctx.txid()[:8]}_{output_idx}'
                    # note that cltv_expiry, and therefore also locktime will be zero when breach!
                    , cltv_expiry=cltv_expiry, locktime=cltv_expiry)
       -
            sig = bfh(tx.sign_txin(0, privkey))
            if not is_revocation:
                witness = construct_witness([sig, preimage, witness_script])
       t@@ -402,8 +397,7 @@ def create_sweeptx_their_ctx_htlc(ctx: Transaction, witness_script: bytes, sweep
        
        
        def create_sweeptx_their_ctx_to_remote(sweep_address: str, ctx: Transaction, output_idx: int,
       -                                       our_payment_privkey: ecc.ECPrivkey,
       -                                       fee_per_kb: int=None) -> Optional[Transaction]:
       +                                       our_payment_privkey: ecc.ECPrivkey) -> Optional[Transaction]:
            our_payment_pubkey = our_payment_privkey.get_public_key_hex(compressed=True)
            val = ctx.outputs()[output_idx].value
            sweep_inputs = [{
       t@@ -417,8 +411,7 @@ def create_sweeptx_their_ctx_to_remote(sweep_address: str, ctx: Transaction, out
                'signatures': [None],
            }]
            tx_size_bytes = 110  # approx size of p2wpkh->p2wpkh
       -    if fee_per_kb is None: fee_per_kb = FEERATE_FALLBACK_STATIC_FEE
       -    fee = SimpleConfig.estimate_fee_for_feerate(fee_per_kb, tx_size_bytes)
       +    fee = estimate_fee(tx_size_bytes)
            outvalue = val - fee
            if outvalue <= dust_threshold(): return None
            sweep_outputs = [TxOutput(TYPE_ADDRESS, sweep_address, outvalue)]
       t@@ -432,8 +425,7 @@ def create_sweeptx_their_ctx_to_remote(sweep_address: str, ctx: Transaction, out
        
        def create_sweeptx_ctx_to_local(sweep_address: str, ctx: Transaction, output_idx: int, witness_script: str,
                                        privkey: bytes, is_revocation: bool,
       -                                to_self_delay: int=None,
       -                                fee_per_kb: int=None) -> Optional[Transaction]:
       +                                to_self_delay: int=None) -> Optional[Transaction]:
            """Create a txn that sweeps the 'to_local' output of a commitment
            transaction into our wallet.
        
       t@@ -456,9 +448,7 @@ def create_sweeptx_ctx_to_local(sweep_address: str, ctx: Transaction, output_idx
                assert isinstance(to_self_delay, int)
                sweep_inputs[0]['sequence'] = to_self_delay
            tx_size_bytes = 121  # approx size of to_local -> p2wpkh
       -    if fee_per_kb is None:
       -        fee_per_kb = FEERATE_FALLBACK_STATIC_FEE
       -    fee = SimpleConfig.estimate_fee_for_feerate(fee_per_kb, tx_size_bytes)
       +    fee = estimate_fee(tx_size_bytes)
            outvalue = val - fee
            if outvalue <= dust_threshold():
                return None
       t@@ -475,8 +465,7 @@ def create_sweeptx_ctx_to_local(sweep_address: str, ctx: Transaction, output_idx
        def create_sweeptx_that_spends_htlctx_that_spends_htlc_in_ctx(
                name_prefix: str,
                htlc_tx: Transaction, htlctx_witness_script: bytes, sweep_address: str,
       -        privkey: bytes, is_revocation: bool, to_self_delay: int,
       -        fee_per_kb: int=None) -> Optional[Transaction]:
       +        privkey: bytes, is_revocation: bool, to_self_delay: int) -> Optional[Transaction]:
            val = htlc_tx.outputs()[0].value
            sweep_inputs = [{
                'scriptSig': '',
       t@@ -493,8 +482,7 @@ def create_sweeptx_that_spends_htlctx_that_spends_htlc_in_ctx(
                assert isinstance(to_self_delay, int)
                sweep_inputs[0]['sequence'] = to_self_delay
            tx_size_bytes = 200  # TODO
       -    if fee_per_kb is None: fee_per_kb = FEERATE_FALLBACK_STATIC_FEE
       -    fee = SimpleConfig.estimate_fee_for_feerate(fee_per_kb, tx_size_bytes)
       +    fee = estimate_fee(tx_size_bytes)
            outvalue = val - fee
            if outvalue <= dust_threshold(): return None
            sweep_outputs = [TxOutput(TYPE_ADDRESS, sweep_address, outvalue)]
   DIR diff --git a/electrum/lnworker.py b/electrum/lnworker.py
       t@@ -529,30 +529,35 @@ class LNWallet(LNWorker):
        
                # create and broadcast transaction
                for prevout, e_tx in chan.sweep_info.items():
       +            name, csv_delay, cltv_expiry, gen_tx = e_tx
                    if spenders.get(prevout) is not None:
                        self.logger.info(f'outpoint already spent {prevout}')
                        continue
                    prev_txid, prev_index = prevout.split(':')
                    broadcast = True
       -            if e_tx.cltv_expiry:
       +            if cltv_expiry:
                        local_height = self.network.get_local_height()
       -                remaining = e_tx.cltv_expiry - local_height
       +                remaining = cltv_expiry - local_height
                        if remaining > 0:
                            self.logger.info('waiting for {}: CLTV ({} > {}), funding outpoint {} and tx {}'
       -                                     .format(e_tx.name, local_height, e_tx.cltv_expiry, funding_outpoint[:8], prev_txid[:8]))
       +                                     .format(name, local_height, cltv_expiry, funding_outpoint[:8], prev_txid[:8]))
                            broadcast = False
       -            if e_tx.csv_delay:
       +            if csv_delay:
                        prev_height = self.network.lnwatcher.get_tx_height(prev_txid)
       -                remaining = e_tx.csv_delay - prev_height.conf
       +                remaining = csv_delay - prev_height.conf
                        if remaining > 0:
                            self.logger.info('waiting for {}: CSV ({} >= {}), funding outpoint {} and tx {}'
       -                                     .format(e_tx.name, prev_height.conf, e_tx.csv_delay, funding_outpoint[:8], prev_txid[:8]))
       +                                     .format(name, prev_height.conf, csv_delay, funding_outpoint[:8], prev_txid[:8]))
                            broadcast = False
       +            tx = gen_tx()
       +            if tx is None:
       +                self.logger.info(f'{name} could not claim output: {prevout}, dust')
                    if broadcast:
       -                if not await self.network.lnwatcher.broadcast_or_log(funding_outpoint, e_tx):
       -                    self.logger.info(f'{e_tx.name} could not publish encumbered tx: {str(e_tx)}, prevout: {prevout}')
       +                if not await self.network.lnwatcher.broadcast_or_log(funding_outpoint, tx):
       +                    self.logger.info(f'{name} could not publish encumbered tx: {str(tx)}, prevout: {prevout}')
                    else:
       -                self.wallet.add_future_tx(e_tx, remaining)
       +                # it's OK to add local transaction, the fee will be recomputed
       +                self.wallet.add_future_tx(tx, remaining)
        
            def is_dangerous(self, chan):
                for x in chan.get_unfulfilled_htlcs():
   DIR diff --git a/electrum/simple_config.py b/electrum/simple_config.py
       t@@ -44,6 +44,14 @@ def set_config(c):
            global config
            config = c
        
       +def estimate_fee(tx_size_bytes):
       +    global config
       +    if config:
       +        fee = config.estimate_fee(tx_size_bytes)
       +    else:
       +        fee_per_kb = FEERATE_FALLBACK_STATIC_FEE
       +        fee = SimpleConfig.estimate_fee_for_feerate(fee_per_kb, tx_size_bytes)
       +    return fee
        
        FINAL_CONFIG_VERSION = 3
        
   DIR diff --git a/electrum/tests/regtest/regtest.sh b/electrum/tests/regtest/regtest.sh
       t@@ -132,13 +132,18 @@ if [[ $1 == "redeem_htlcs" ]]; then
            chan_id=$($alice list_channels | jq -r ".[0].channel_point")
            $alice close_channel $chan_id --force
            new_blocks 1
       -    sleep 5
       +    sleep 3
            echo "alice balance after closing channel:" $($alice getbalance)
            new_blocks 144
            sleep 10
            new_blocks 1
       +    sleep 3
       +    echo "alice balance after CLTV" $($alice getbalance)
       +    new_blocks 144
            sleep 10
       -    echo "alice balance after 144 blocks:" $($alice getbalance)
       +    new_blocks 1
       +    sleep 3
       +    echo "alice balance after CSV" $($alice getbalance)
            balance_after=$($alice getbalance |  jq '[.confirmed, .unconfirmed] | to_entries | map(select(.value != null).value) | map(tonumber) | add ')
            if (( $(echo "$balance_before - $balance_after > 0.02" | bc -l) )); then
                echo "htlc not redeemed."