Lagrang3 points out that if we hit a maximum, we should take into account
the reserve. This is true, but it's hard for the caller to do, so change
the API to be slightly higher level.
Tell "inform" what happened, and it adjust the constraints appropriately.
This makes the least assumptions possible (a reserve does *not* mean that
the capacity was actually used at that time).
We also add a mode to say "this succeeded": for now this does nothing,
but it could reduce both min/max capacities, and add capacity in the
other direction. This is useful for future payments, but not as useful
for the current one.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
I got confused, as we had a struct containing two arrays. Simply expose the
reserve_hop struct and use arrays directly.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
It's generally better to be explicit with these things: currently typos
would be ignored. But it's also much easier to clean up entire layers
as we use them for temporary (per-payment) effects.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
I like the clarity, but this is a hot path. Fortunately these arrays
have very well defined lengths.
Before: 5.81 seconds
After: 1.06 seconds
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We only ever visit each node once, so we can just use an array. This
avoids calling tal() all the time, which is *especially* slow when we're
memory tracking.
I had an old canned gossmap which I benchmarked for these (and in
particular one node was unreachable, and that was slow):
Before: 17.27 seconds
After: 5.80 seconds
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We bump the version to minor version 0.2 to allow ourselves to bump on
patch level when we need to fix a bug or update a dependency.
Changelog-Changed: Plugins: `cln-grpc` Upgrade tonic version and
introduce new versioning scheme.
Signed-off-by: Peter Neuroth <pet.v.ne@gmail.com>
Tonic had some breaking changes since 0.8. We want to be closer to newer
versions for downstream consumers to be able to benefit from changes in tonic.
Signed-off-by: Peter Neuroth <pet.v.ne@gmail.com>
askrene.c was getting quite long, and this is self-contained.
The only code change is a convenience accessor for the per-htlc-cost
hash table.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
"spendable" is for a single HTLC: if we own the channel, this amount
decreases with every HTLC, as we have to pay fees. We have access to this since
we call listpeerchannels anyway, so we can calculate the additional costs and
use it in the refining phase.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We don't actually hit the htlc_max cases, since the flow code already
constrains us to that.
And handling htlc_min is better done in the caller, where diagnostics
are better (basically, we should eliminate them, and if that means no
route, give a clear error message).
And the refinement step can handle any extra millisats from rounding.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This is the root cause of the problem worked around in 50949b7b9c
"askrene: hack in some padding so we don't overflow capacities."
When adding fees to flows, we didn't recheck the boundary conditions: in
renepay this is done by routebuilder.
Fortunately, we can use our "reservations" infrastructure to temporarily
use capacity as we process flows, so we handle the cases where they are
not independent correclty.
My assumption is that the resulting errors are small, so we divide
them between the remaining flows based on highest-to-least
probability.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Simply calculate it when we need it, which means we don't have to keep it
up-to-date as we tweak the flow.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Rather than making the callers do this, make the invoice decoder perform
the various sanity checks.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We had a workaround for channels added by "auto.local", but instead we
should make it work properly.
I didn't do this before because we can't manipulate the localmods while
they're applied, but it's simple to do it in two stages.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
I used `amount_msat_eq(x, AMOUNT_MSAT(0))` because I forgot this
function existed. I probably missed it because the name is surprising,
so add "is" in there to make it clear it's a boolean function.
You'll note almost all the places which did use it are Eduardo's and
Lisa's code, so maybe it's just me.
Fix up a few places which I could use it, too.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
In commit 60e1532dd8 (released in crate 0.1.8), which switched the
logging framework to tracing-subscriber, the default log level filter
was (accidentally) set to ERROR and above, instead of INFO and above.
Change this back to INFO as it was before. It can still be overridden
with CLN_PLUGIN_LOG.
Follows the example in https://docs.rs/tracing-subscriber/latest/tracing_subscriber/filter/struct.EnvFilter.html#method.from_envCloses#7658.
Changelog-Fixed: cln-plugin: Change default log level filter back to INFO
It's an output field (which we don't complain about), not an input field!
Fixes: https://github.com/ElementsProject/lightning/issues/7652
Changelog-Fixed: Logging: removed bogus "**BROKEN** plugin-topology: DEPRECATED API USED: listchannels.include_private" message.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Of course, we still will, since spendable is for a single HTLC, but
this also shows why we should treat *minimum* as the incorrect answer
if they cross, too.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Fixes: https://github.com/ElementsProject/lightning/issues/7563
It seems we didn't handle it correctly: we need to cap the first
segment as well as the others, as far as I can tell.
Also, it can be less than the maximum capacity.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Conversion is lossy, and we don't want to spend more than the channel,
so it's conservative to round down here.
This doesn't actually help our test though!
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
You need to know it to make an onion, and in theory if we decided to
fuzz it could be different for different paths.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Channel filter must apply to the modified gossmap+localmods,
otherwise we disable local channels with htlcmax=0.
Signed-off-by: Lagrang3 <lagrang3@protonmail.com>
Add a little bit of uncertainty to the local channels to avoid
consuming precisely all spendable_msat on our side, which leads to
temporary channel failure if the spendable_msat changes during the
course of the payment.
Signed-off-by: Lagrang3 <lagrang3@protonmail.com>
Refresh gossmap once before we read the routehints.
Make sure that if channels in the routehints are public,
we retrieve their capacities from gossip.
Signed-off-by: Lagrang3 <lagrang3@protonmail.com>
- add more checks
- add more error messages
- compute probabilities without fees during MCF
- compute probabilities with fees during get_routes
Signed-off-by: Lagrang3 <lagrang3@protonmail.com>
In theory we should not have htlc_total<=known_max.
But for some strange race condition we do sometimes.
Until we find a solution to ensure the correct state
of the uncertainty network we remove the assertion.
Thanks to signed arithmetic and MIN guards, the rest
of the code in linearize_channel can handle the
weird cases with known_max<htlc_total.
Signed-off-by: Lagrang3 <lagrang3@protonmail.com>
The probability for a success forward of x amount on a channel is now
computed as:
P_success(x) = b * P_rene(x)
where P_rene(x) is the probability distribution proposed by Rene
Pickhardt with a uniform distribution on the known liquidity of the
channel and 'b' is a new parameter we add in this PR, by the name of
"base probability". The "base probability" represents the probability
for a channel in the network choosen at random to be able to forward at
least 1msat, ie. of being alive, non-depleted and with at least one HTLC
slot. We don't know the value of 'b', but for the moment we assume that
it is 0.98 and use that as default.
As a consequence the probability cost becomes non-linear and non-convex
because of the additional constant term:
Cost(x) = - log P_success(x)
= - log b - - log P_rene(x)
= - log b + Cost_rene(x)
We currently don't handle well base fees and neither this additional
"base probability" but we can as a first approximation linearize the
cost function in this way:
Cost_linear(x) = (- log b)*x + Cost_rene_linear(x)
Changelog-Added: renepay: Add a dev parameter to renepay that represents
a constant probability of availability for all channels in the network.
Signed-off-by: Lagrang3 <lagrang3@protonmail.com>
