The option to add a 2nd trampoline hop to legacy trampoline payments requires too much space in the trampoline onion.
Because the trampoline onion has only limited space of 400b and the payload with 2nd t hop and no r_tags already requires 392b it is essentially unusable for payments that require routing hints to be included in the onion
(because the receiver has no direct channel to the 2nd trampoline node)
as there is no space left to include them (1r_tag == ~52b).
make min funding amount symbol, change Signal name, change Exception type
change minChannelFunding to QEAmount and make message text variable
qml: improve translatibility of strings
init minchannelfunding value in init method
rebase on master
- Wallet.make_unsigned_transaction takes a FeePolicy parameter
- fee sliders act on a FeePolicy instead of config
- different fee policies may be used for different purposes
- do not detect dust outputs in lnsweep, delegate that to lnwatcher
- reduce number of methods
- use nametuples instead of dicts
- only two types: OnchainHistoryItem and LightningHistoryItem
- channel open/closes are groups
- move capital gains into separate RPC
store exception in variable instead of using a bool flag
add default str to routing exceptions
Add separate exception class to handle fee related payment errors
force-closed. Assert final balance in lnworker.get_history().
If we offered some HTLCs, we do not know yet whether they will be
redeemed by us or by the remote.
Ideally, given an on-chain backup, after the remote force-closes, we should be able to spend our anchor output,
to CPFP the remote commitment tx (assuming the channel used OPTION_ANCHORS).
To spend the anchor output, we need to be able to sign with the local funding_privkey.
Previously we derived the funding_key from the channel_seed (which comes from os.urandom).
Prior to anchors, there was no use case for signing with the funding_key given a channel backup.
Now with anchors, we should make its derivation deterministic somehow, in a way so that it can
be derived given just an on-chain backup.
- one way would be to put some more data into the existing OP_RETURN
- uses block space
- the OP_RETURNs can be disabled via "use_recoverable_channels"
- only the initiator can use OP_RETURNs (so what if channel is in incoming dir?)
- instead, new scheme for our funding_key:
- we derive the funding_privkey from the lnworker root secret (derived from our bip32 seed)
- for outgoing channels:
- lnworker_root_secret + remote_node_id + funding_tx_nlocktime
- for incoming channels:
- lnworker_root_secret + remote_node_id + remote_funding_pubkey
- a check is added to avoid reusing the same key between channels:
not letting to user open more than one channel with the same peer in a single block
- only the first 16 bytes of the remote_node_id are used, as the onchain backup OP_RETURNs only contain that
- as the funding_privkey cannot be derived from the channel_seed anymore, it is included in the
imported channel backups, which in turn need a new version defined
- a wallet db upgrade is used to update already stored imported cbs
- alternatively we could keep the imported cbs as-is, so no new version, no new funding_privkey field, as it is clearly somewhat redundant given on-chain backups can reconstruct it
- however adding the field seems easier
- otherwise the existing code would try to derive the funding_privkey from the channel_seed
- also note: atm there is no field in the imported backups to distinguish anchor channels vs static-remotekey channels
