120 lines
3.9 KiB
Python
Executable File
120 lines
3.9 KiB
Python
Executable File
#!/usr/bin/env python3
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"""Test plugin for adding inputs/outputs to a dual-funded transaction
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"""
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from pyln.client import Plugin, Millisatoshi
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from pyln.proto import bech32_decode
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from typing import Iterable, List, Optional
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from wallycore import psbt_add_output_at, psbt_from_base64, psbt_to_base64, tx_output_init
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plugin = Plugin()
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def convertbits(data: Iterable[int], frombits: int, tobits: int, pad: bool = True) -> Optional[List[int]]:
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"""General power-of-2 base conversion."""
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acc = 0
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bits = 0
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ret = []
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maxv = (1 << tobits) - 1
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max_acc = (1 << (frombits + tobits - 1)) - 1
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for value in data:
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if value < 0 or (value >> frombits):
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return None
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acc = ((acc << frombits) | value) & max_acc
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bits += frombits
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while bits >= tobits:
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bits -= tobits
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ret.append((acc >> bits) & maxv)
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if pad:
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if bits:
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ret.append((acc << (tobits - bits)) & maxv)
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elif bits >= frombits or ((acc << (tobits - bits)) & maxv):
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return None
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return ret
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def get_script(bech_addr):
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hrp, data = bech32_decode(bech_addr)
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# FIXME: verify hrp matches expected network
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wprog = convertbits(data[1:], 5, 8, False)
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wit_ver = data[0]
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if wit_ver > 16:
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raise ValueError("Invalid witness version {}".format(wit_ver[0]))
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return bytes([wit_ver + 0x50 if wit_ver > 0 else wit_ver, len(wprog)] + wprog)
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def find_feerate(best, their_min, their_max, our_min, our_max):
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if best >= our_min and best <= our_max:
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return best
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if their_max < our_min or their_min > our_max:
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return False
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if best < our_min:
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return our_min
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# best > our_max:
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return our_max
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@plugin.hook('openchannel2')
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def on_openchannel(openchannel2, plugin, **kwargs):
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# We mirror what the peer does, wrt to funding amount ...
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amount = openchannel2['their_funding']
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locktime = openchannel2['locktime']
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# ...unless they send us totally unacceptable feerates.
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feerate = find_feerate(openchannel2['funding_feerate_best'],
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openchannel2['funding_feerate_min'],
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openchannel2['funding_feerate_max'],
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openchannel2['feerate_our_min'],
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openchannel2['feerate_our_max'])
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# Their feerate range is out of bounds, we're not going to
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# participate.
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if not feerate:
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return {'result': 'continue'}
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funding = plugin.rpc.fundpsbt(amount,
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'{}perkw'.format(feerate),
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0, reserve=True,
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locktime=locktime)
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psbt_obj = psbt_from_base64(funding['psbt'])
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excess = Millisatoshi(funding['excess_msat'])
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change_cost = Millisatoshi(124 * feerate // 1000 * 1000)
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dust_limit = Millisatoshi(253 * 1000)
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if excess > (dust_limit + change_cost):
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addr = plugin.rpc.newaddr()['bech32']
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change = excess - change_cost
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output = tx_output_init(int(change.to_satoshi()), get_script(addr))
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psbt_add_output_at(psbt_obj, 0, 0, output)
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return {'result': 'continue', 'psbt': psbt_to_base64(psbt_obj, 0),
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'accepter_funding_msat': amount,
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'funding_feerate': feerate}
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@plugin.hook('openchannel2_changed')
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def on_tx_changed(openchannel2_changed, plugin, **kwargs):
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# In this example, we have nothing to add, so we
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# pass back the same psbt that was forwarded in here
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return {'result': 'continue', 'psbt': openchannel2_changed['psbt']}
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@plugin.hook('openchannel2_sign')
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def on_tx_sign(openchannel2_sign, plugin, **kwargs):
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psbt = openchannel2_sign['psbt']
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# We only sign the ones with our parity of a serial_id
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# FIXME: find the inputs with an odd-serial, these are ours
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# the key for a serial_id ::
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# our_inputs = [1]
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signed_psbt = plugin.rpc.signpsbt(psbt)['signed_psbt']
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return {'result': 'continue', 'psbt': signed_psbt}
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plugin.run()
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