def deposit(from_offset, to_offset):
return get_pessimistic_udc_balance(
udc=user_deposit_contract,
address=address,
from_block=deposit_block + from_offset,
to_block=deposit_block + to_offset,
)
def action_monitoring_triggered_event_handler(event: Event,
context: Context) -> None:
assert isinstance(event, ActionMonitoringTriggeredEvent)
log.info("Triggering channel monitoring")
monitor_request = context.database.get_monitor_request(
token_network_address=event.token_network_address,
channel_id=event.channel_identifier,
non_closing_signer=event.non_closing_participant,
)
if monitor_request is None:
log.error(
"MonitorRequest cannot be found",
token_network_address=event.token_network_address,
channel_id=event.channel_identifier,
)
metrics.get_metrics_for_label(metrics.ERRORS_LOGGED,
metrics.ErrorCategory.STATE).inc()
return
channel = context.database.get_channel(
token_network_address=monitor_request.token_network_address,
channel_id=monitor_request.channel_identifier,
)
if channel is None:
log.error("Channel cannot be found", monitor_request=monitor_request)
metrics.get_metrics_for_label(metrics.ERRORS_LOGGED,
metrics.ErrorCategory.STATE).inc()
return
if not _is_mr_valid(monitor_request, channel):
log.error(
"MonitorRequest lost its validity",
monitor_request=monitor_request,
channel=channel,
)
metrics.get_metrics_for_label(metrics.ERRORS_LOGGED,
metrics.ErrorCategory.PROTOCOL).inc()
return
last_onchain_nonce = 0
if channel.update_status:
last_onchain_nonce = channel.update_status.nonce
if monitor_request.nonce <= last_onchain_nonce:
log.info(
"Another MS submitted the last known channel state",
monitor_request=monitor_request,
)
return
latest_block = context.web3.eth.blockNumber
last_confirmed_block = context.latest_confirmed_block
user_address = monitor_request.non_closing_signer
user_deposit = get_pessimistic_udc_balance(
udc=context.user_deposit_contract,
address=user_address,
from_block=last_confirmed_block,
to_block=latest_block,
)
if monitor_request.reward_amount < context.min_reward:
log.info(
"Monitor request not executed due to insufficient reward amount",
monitor_request=monitor_request,
min_reward=context.min_reward,
)
return
if user_deposit < monitor_request.reward_amount * UDC_SECURITY_MARGIN_FACTOR_MS:
log.debug(
"User deposit is insufficient -> try monitoring again later",
monitor_request=monitor_request,
min_reward=context.min_reward,
)
context.database.upsert_scheduled_event(
ScheduledEvent(
trigger_block_number=BlockNumber(last_confirmed_block + 1),
event=event))
return
assert (channel.monitor_tx_hash is None
), "This MS already monitored this channel. Should be impossible."
try:
# Attackers might be able to construct MRs that make this fail.
# Since we execute a gas estimation before doing the `transact`,
# the gas estimation will fail before any gas is used.
# If we stop doing a gas estimation, a `call` has to be done before
# the `transact` to prevent attackers from wasting the MS's gas.
tx_hash = TransactionHash(
bytes(
context.monitoring_service_contract.functions.monitor(
monitor_request.signer,
monitor_request.non_closing_signer,
monitor_request.balance_hash,
monitor_request.nonce,
monitor_request.additional_hash,
monitor_request.closing_signature,
monitor_request.non_closing_signature,
monitor_request.reward_amount,
monitor_request.token_network_address,
monitor_request.reward_proof_signature,
).transact({"from": context.ms_state.address})))
except Exception as exc: # pylint: disable=broad-except
first_allowed = BlockNumber(
_first_allowed_block_to_monitor(event.token_network_address,
channel, context))
failed_at = context.web3.eth.blockNumber
log.error(
"Sending tx failed",
exc_info=True,
err=exc,
first_allowed=first_allowed,
failed_at=failed_at,
)
metrics.get_metrics_for_label(metrics.ERRORS_LOGGED,
metrics.ErrorCategory.BLOCKCHAIN).inc()
return
log.info(
"Sent transaction calling `monitor` for channel",
token_network_address=channel.token_network_address,
channel_identifier=channel.identifier,
transaction_hash=encode_hex(tx_hash),
)
assert tx_hash is not None
with context.database.conn:
# Add tx hash to list of waiting transactions
context.database.add_waiting_transaction(tx_hash)
channel.monitor_tx_hash = tx_hash
context.database.upsert_channel(channel)
def process_payment( # pylint: disable=too-many-branches
iou: Optional[IOU],
pathfinding_service: PathfindingService,
service_fee: TokenAmount,
one_to_n_address: Address,
) -> None:
if service_fee == 0:
return
if iou is None:
raise exceptions.MissingIOU
# Basic IOU validity checks
if not is_same_address(iou.receiver, pathfinding_service.address):
raise exceptions.WrongIOURecipient(
expected=pathfinding_service.address)
if iou.chain_id != pathfinding_service.chain_id:
raise exceptions.UnsupportedChainID(
expected=pathfinding_service.chain_id)
if iou.one_to_n_address != one_to_n_address:
raise exceptions.WrongOneToNAddress(expected=one_to_n_address,
got=iou.one_to_n_address)
if not iou.is_signature_valid():
raise exceptions.InvalidSignature
# Compare with known IOU
active_iou = pathfinding_service.database.get_iou(sender=iou.sender,
claimed=False)
if active_iou:
if active_iou.expiration_block != iou.expiration_block:
raise exceptions.UseThisIOU(iou=active_iou)
expected_amount = active_iou.amount + service_fee
else:
claimed_iou = pathfinding_service.database.get_iou(
sender=iou.sender,
expiration_block=iou.expiration_block,
claimed=True)
if claimed_iou:
raise exceptions.IOUAlreadyClaimed
min_expiry = pathfinding_service.web3.eth.blockNumber + MIN_IOU_EXPIRY
if iou.expiration_block < min_expiry:
raise exceptions.IOUExpiredTooEarly(min_expiry=min_expiry)
expected_amount = service_fee
if iou.amount < expected_amount:
raise exceptions.InsufficientServicePayment(
expected_amount=expected_amount)
# Check client's deposit in UserDeposit contract
udc = pathfinding_service.user_deposit_contract
latest_block = pathfinding_service.web3.eth.blockNumber
udc_balance = get_pessimistic_udc_balance(
udc=udc,
address=iou.sender,
from_block=latest_block - pathfinding_service.required_confirmations,
to_block=latest_block,
)
required_deposit = round(expected_amount * UDC_SECURITY_MARGIN_FACTOR_PFS)
if udc_balance < required_deposit:
raise exceptions.DepositTooLow(required_deposit=required_deposit)
log.info(
"Received service fee",
sender=iou.sender,
expected_amount=expected_amount,
total_amount=iou.amount,
added_amount=expected_amount - service_fee,
)
# Save latest IOU
iou.claimed = False
pathfinding_service.database.upsert_iou(iou)
def process_payment( # pylint: disable=too-many-branches
iou: Optional[IOU],
pathfinding_service: PathfindingService,
service_fee: TokenAmount,
one_to_n_address: Address,
) -> None:
if service_fee == 0:
if iou is not None:
log.debug(
"Discarding IOU, service fee is 0",
sender=to_checksum_address(iou.sender),
total_amount=iou.amount,
claimable_until=iou.claimable_until,
)
else:
log.debug("No IOU and service fee is 0")
return
if iou is None:
raise exceptions.MissingIOU
log.debug(
"Checking IOU",
sender=to_checksum_address(iou.sender),
total_amount=iou.amount,
claimable_until=iou.claimable_until,
)
# Basic IOU validity checks
if not is_same_address(iou.receiver, pathfinding_service.address):
raise exceptions.WrongIOURecipient(expected=pathfinding_service.address)
if iou.chain_id != pathfinding_service.chain_id:
raise exceptions.UnsupportedChainID(expected=pathfinding_service.chain_id)
if iou.one_to_n_address != one_to_n_address:
raise exceptions.WrongOneToNAddress(expected=one_to_n_address, got=iou.one_to_n_address)
if not iou.is_signature_valid():
raise exceptions.InvalidSignature
# Compare with known IOU
latest_block = pathfinding_service.blockchain_state.latest_committed_block
active_iou = pathfinding_service.database.get_iou(sender=iou.sender, claimed=False)
if active_iou:
if active_iou.claimable_until != iou.claimable_until:
raise exceptions.UseThisIOU(iou=active_iou.Schema().dump(active_iou))
expected_amount = active_iou.amount + service_fee
else:
claimed_iou = pathfinding_service.database.get_iou(
sender=iou.sender, claimable_until=iou.claimable_until, claimed=True
)
if claimed_iou:
raise exceptions.IOUAlreadyClaimed
min_expiry = get_posix_utc_time_now() + MIN_IOU_EXPIRY
if iou.claimable_until < min_expiry:
raise exceptions.IOUExpiredTooEarly(
min_expiry=min_expiry, claimable_until_received=iou.claimable_until
)
expected_amount = service_fee
if iou.amount < expected_amount:
raise exceptions.InsufficientServicePayment(
expected_amount=expected_amount, actual_amount=iou.amount
)
# Check client's deposit in UserDeposit contract
udc = pathfinding_service.user_deposit_contract
udc_balance = get_pessimistic_udc_balance(
udc=udc,
address=iou.sender,
from_block=BlockNumber(latest_block - pathfinding_service.required_confirmations),
to_block=latest_block,
)
required_deposit = round(expected_amount * UDC_SECURITY_MARGIN_FACTOR_PFS)
if udc_balance < required_deposit:
raise exceptions.DepositTooLow(
required_deposit=required_deposit, seen_deposit=udc_balance, block_number=latest_block
)
log.info(
"Received service fee",
sender=iou.sender,
expected_amount=expected_amount,
total_amount=iou.amount,
added_amount=expected_amount - service_fee,
)
# Save latest IOU
iou.claimed = False
pathfinding_service.database.upsert_iou(iou)