This happens to be an edge case with the way we use `sendonion` in
MPP. `sendonion` does not attempt to recover the route even if we supply the
shared secrets (it'd require us to map forwarding channels to the nodes etc),
so `failnode` will always be unset, unless it is the first hop, which gets
stored. This is not a problem if it weren't for the fact that we don't store
the partial route, consisting solely of the channel leading to the first hop,
therefore the assertion that either both are NULL or both aren't fails on the
first hop.
This went unnoticed since with MPP we have more concurrent payments in flight,
increasing the chances of a exhausted first hop considerably.
This modifier splits a payment that has been attempted a number of times (by a
modifier earlier in the mod chain) and has failed consistently. It splits the
amount roughly in half, with a but if random fuzz, and then starts a new round
of attempts for the two smaller amounts.
Changelog-Added: The MPP presplit modifier splits large payments into 10k satoshi parts to maximize chances of performing the payment and to obfuscate the overall amount being sent.
With the `presplit`-modifier we actually skip execution of the root altogether
which results in the root not having a result at all. Instead we should use
the result returned by `payment_collect_result`.
With MPP we require that the sum of parts is equal to the `total_msat` amount
declared in the onion. Since that can't be changed once the first part arrives
we need a way to disable amount fuzzing for MPP.
We were applying the fee exemption to all payments individually, which is ok
until we switch to MPP, where amounts change. Also the log entry was referring
to the total amount, and not the fee of the payment.
This was causing the state flapping test to fail, since we were yielding
control of the io_loop, waiting for the blockheight to be reached, and not
setting the status beforehand. An interim `paystatus` call would then find a
failed leaf and deduce the entire payment failed. Setting it back to the
previous state keeps the overall payment pending while we wait.
As suggested during the paymod-03 review it is better to activate the new code
right away, and give users an escape hatch to use the legacy code instead. The
way I implemented it allows using either `legacypay` or `pay` and then set
`legacy` to switch to the other implementation.
Changelog-Added: JSON-RPC: The `pay` command now uses the new payment flow, the new `legacypay` command can be used to issue payment with the legacy code if required.
Suggested-by: Rusty Russell <@rustyrussell>
Suggested-by: ZmnSCPxj <@zmnscpxj>
This makes use of the payment modifier structure to just add the preimage to
the TLV payload for the last hop.
Changelog-Added: JSON-RPC: The `keysend` command allows sending to a node without requiring an invoice first.
PSETs have a bit different requirements. The witness_utxo needs
the asset tag + values, and these should also be added to the PSET
struct separately as well. To do this, we create a new 'init' method for
elements inputs, which takes care of the elements specific things.
We don't preserve detailed asset information at the moment, so provide a
way to convert from a sat to an amount_asset struct.
We also need a way to convert from an 'amount_asset' to a 'value' for
elements, which for explicit (i.e. non-blinded) asssets is a 0x01 prefix
plus the big-endian encoded value.
If you used feerate=750, instead of feerate="750" it didn't work, since the
token is not a string.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Changelog-Fixed: JSON RPC: `withdraw` and `txprepare` `feerate` can be a JSON number.
It turns out that the `failcodename` doesn't get populated if the `failcode`
isn't a known error from the enum (duh...) so don't fail parsing if it's
missing.
This commit collects the changes required to the tests caused by the changes
to the `pay` and `paystatus` commands. They are also rather good hints as to
what these changes entail.
Christian Decker
Rusty Russell
niftynei
ZmnSCPxj jxPCSnmZ