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lightning channel reserves

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This commit is contained in:
Janus
2018-10-23 20:32:18 +02:00
committed by ThomasV
parent 54edc9488a
commit 15b0720f5e
4 changed files with 176 additions and 33 deletions
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69
electrum/lnchan.py
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@@ -18,7 +18,7 @@ from .lnutil import sign_and_get_sig_string, privkey_to_pubkey, make_htlc_tx_wit
from .lnutil import make_htlc_tx_with_open_channel, make_commitment, make_received_htlc, make_offered_htlc
from .lnutil import HTLC_TIMEOUT_WEIGHT, HTLC_SUCCESS_WEIGHT
from .lnutil import funding_output_script, LOCAL, REMOTE, HTLCOwner, make_closing_tx, make_commitment_outputs
from .lnutil import ScriptHtlc, SENT, RECEIVED, PaymentFailure, calc_onchain_fees
from .lnutil import ScriptHtlc, SENT, RECEIVED, PaymentFailure, calc_onchain_fees, RemoteMisbehaving
from .transaction import Transaction, TxOutput, construct_witness
from .simple_config import SimpleConfig, FEERATE_FALLBACK_STATIC_FEE
@@ -131,6 +131,7 @@ class Channel(PrintError):
template = lambda: {
'adds': {}, # Dict[HTLC_ID, UpdateAddHtlc]
'settles': [], # List[HTLC_ID]
'fails': [], # List[HTLC_ID]
}
self.log = {LOCAL: template(), REMOTE: template()}
for strname, subject in [('remote_log', REMOTE), ('local_log', LOCAL)]:
@@ -159,23 +160,23 @@ class Channel(PrintError):
def get_state(self):
return self._state
def check_can_pay(self, amount_msat: int) -> None:
# FIXME channel reserve
def _check_can_pay(self, amount_msat: int) -> None:
if self.get_state() != 'OPEN':
raise PaymentFailure('Channel not open')
if self.available_to_spend(LOCAL) < amount_msat:
raise PaymentFailure('Not enough local balance')
if len(self.htlcs(LOCAL, only_pending=True)) + 1 > self.config[REMOTE].max_accepted_htlcs:
raise PaymentFailure('Too many HTLCs already in channel')
if htlcsum(self.htlcs(LOCAL, only_pending=True)) + amount_msat > self.config[REMOTE].max_htlc_value_in_flight_msat:
raise PaymentFailure('HTLC value sum would exceed max allowed: {} msat'.format(self.config[REMOTE].max_htlc_value_in_flight_msat))
current_htlc_sum = htlcsum(self.htlcs(LOCAL, only_pending=True))
if current_htlc_sum + amount_msat > self.config[REMOTE].max_htlc_value_in_flight_msat:
raise PaymentFailure(f'HTLC value sum (sum of pending htlcs: {current_htlc_sum/1000} sat plus new htlc: {amount_msat/1000} sat) would exceed max allowed: {self.config[REMOTE].max_htlc_value_in_flight_msat/1000} sat')
if amount_msat <= 0: # FIXME htlc_minimum_msat
raise PaymentFailure(f'HTLC value too small: {amount_msat} msat')
def can_pay(self, amount_msat):
try:
self.check_can_pay(amount_msat)
except:
self._check_can_pay(amount_msat)
except PaymentFailure:
return False
return True
@@ -196,6 +197,7 @@ class Channel(PrintError):
should be called when preparing to send an outgoing HTLC.
"""
assert type(htlc) is dict
self._check_can_pay(htlc['amount_msat'])
htlc = UpdateAddHtlc(**htlc, htlc_id=self.config[LOCAL].next_htlc_id)
self.log[LOCAL]['adds'][htlc.htlc_id] = htlc
self.print_error("add_htlc")
@@ -210,7 +212,10 @@ class Channel(PrintError):
"""
assert type(htlc) is dict
htlc = UpdateAddHtlc(**htlc, htlc_id = self.config[REMOTE].next_htlc_id)
self.log[REMOTE]['adds'][htlc.htlc_id] = htlc
if self.available_to_spend(REMOTE) < htlc.amount_msat:
raise RemoteMisbehaving('Remote dipped below channel reserve')
adds = self.log[REMOTE]['adds']
adds[htlc.htlc_id] = htlc
self.print_error("receive_htlc")
self.config[REMOTE]=self.config[REMOTE]._replace(next_htlc_id=htlc.htlc_id + 1)
return htlc.htlc_id
@@ -228,10 +233,8 @@ class Channel(PrintError):
any). The HTLC signatures are sorted according to the BIP 69 order of the
HTLC's on the commitment transaction.
"""
for htlc in self.log[LOCAL]['adds'].values():
if htlc.locked_in[LOCAL] is None:
htlc.locked_in[LOCAL] = self.config[LOCAL].ctn
self.print_error("sign_next_commitment")
self.lock_in_htlc_changes(LOCAL)
pending_remote_commitment = self.pending_remote_commitment
sig_64 = sign_and_get_sig_string(pending_remote_commitment, self.config[LOCAL], self.config[REMOTE])
@@ -265,6 +268,17 @@ class Channel(PrintError):
return sig_64, htlcsigs
def lock_in_htlc_changes(self, subject):
for sub in (LOCAL, REMOTE):
for htlc_id in self.log[-sub]['fails']:
adds = self.log[sub]['adds']
htlc = adds.pop(htlc_id)
self.log[-sub]['fails'].clear()
for htlc in self.log[subject]['adds'].values():
if htlc.locked_in[subject] is None:
htlc.locked_in[subject] = self.config[subject].ctn
def receive_new_commitment(self, sig, htlc_sigs):
"""
ReceiveNewCommitment process a signature for a new commitment state sent by
@@ -276,11 +290,8 @@ class Channel(PrintError):
state, then this newly added commitment becomes our current accepted channel
state.
"""
self.print_error("receive_new_commitment")
for htlc in self.log[REMOTE]['adds'].values():
if htlc.locked_in[REMOTE] is None:
htlc.locked_in[REMOTE] = self.config[REMOTE].ctn
self.lock_in_htlc_changes(REMOTE)
assert len(htlc_sigs) == 0 or type(htlc_sigs[0]) is bytes
pending_local_commitment = self.pending_local_commitment
@@ -479,9 +490,16 @@ class Channel(PrintError):
return initial
def available_to_spend(self, subject):
# FIXME what about channel_reserve_satoshis? will the remote fail the channel if we go below? test.
# FIXME what about tx fees
return self.balance(subject) - htlcsum(self.htlcs(subject, only_pending=True))
return self.balance(subject)\
- htlcsum(self.log[subject]['adds'].values())\
- 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,
self.constraints.is_initiator,
)[subject]
def amounts(self):
remote_settled= htlcsum(self.htlcs(REMOTE, False))
@@ -536,8 +554,11 @@ class Channel(PrintError):
res = []
for htlc in update_log['adds'].values():
locked_in = htlc.locked_in[subject]
if locked_in is None or only_pending == (htlc.htlc_id in other_log['settles']):
settled = htlc.htlc_id in other_log['settles']
failed = htlc.htlc_id in other_log['fails']
if locked_in is None:
continue
if only_pending == (settled or failed):
continue
res.append(htlc)
return res
@@ -561,11 +582,11 @@ class Channel(PrintError):
def fail_htlc(self, htlc_id):
self.print_error("fail_htlc")
self.log[REMOTE]['adds'].pop(htlc_id)
self.log[LOCAL]['fails'].append(htlc_id)
def receive_fail_htlc(self, htlc_id):
self.print_error("receive_fail_htlc")
self.log[LOCAL]['adds'].pop(htlc_id)
self.log[REMOTE]['fails'].append(htlc_id)
@property
def current_height(self):
@@ -665,8 +686,8 @@ class Channel(PrintError):
def make_commitment(self, subject, this_point) -> Transaction:
remote_msat, local_msat = self.amounts()
assert local_msat >= 0
assert remote_msat >= 0
assert local_msat >= 0, local_msat
assert remote_msat >= 0, remote_msat
this_config = self.config[subject]
other_config = self.config[-subject]
other_htlc_pubkey = derive_pubkey(other_config.htlc_basepoint.pubkey, this_point)