AMP payments

[antonilol]

#353 + more commits

depends on stakwork/sphinx-stack#33

closes #361
closes #401

[antonilol]

lncli -n regtest sendpayment --dest=02a38857848aca6b32ebcc3c85d07ee41354988f4f1e0b4e6ccd255eee6ed75b8d --amt=1500000 --amp
+------------+--------------+--------------+--------------+-----+----------+-----------------+---------+
| HTLC_STATE | ATTEMPT_TIME | RESOLVE_TIME | RECEIVER_AMT | FEE | TIMELOCK | CHAN_OUT        | ROUTE   |
+------------+--------------+--------------+--------------+-----+----------+-----------------+---------+
| SUCCEEDED  |        0.020 |        0.137 | 750000       | 0   |      206 | 158329674465280 | bob-lnd |
| SUCCEEDED  |        0.032 |        0.135 | 750000       | 0   |      206 | 169324790743040 | bob-lnd |
+------------+--------------+--------------+--------------+-----+----------+-----------------+---------+
Amount + fee:   1500000 + 0 sat
Payment hash:   3e344bfdbe845774c24506c2efb6a97752fb40c5c081cd0d4ada8e2afca0a612
Payment status: SUCCEEDED, preimage: 9639b62a3b1322d1f6e7fee6b5c0c8b76317ec02f0623e6a2940993300e7d9bd

amp works from alice to bob in the docker containers with 2 channels of 1 mil sat each on the sphinx stack branch with accept amp in the confs

[antonilol]

sometimes the test fails when adding the contacts (even before the payment)

npx ava src/tests/controllers/ampMessage.test.ts --verbose --serial --timeout=2m

alice and bob
adding contact
  ✖ test-15-ampMessage: send more sats than one channel can handle to test AMP Rejected promise returned by test
  ─

  test-15-ampMessage: send more sats than one channel can handle to test AMP

  Rejected promise returned by test. Reason:

  'failed to getContactAndCheckKeyExchange'

  ─

  1 test failed

[kevkevinpal]

sometimes the test fails when adding the contacts (even before the payment)

npx ava src/tests/controllers/ampMessage.test.ts --verbose --serial --timeout=2m

alice and bob
adding contact
  ✖ test-15-ampMessage: send more sats than one channel can handle to test AMP Rejected promise returned by test
  ─

  test-15-ampMessage: send more sats than one channel can handle to test AMP

  Rejected promise returned by test. Reason:

  'failed to getContactAndCheckKeyExchange'

  ─

  1 test failed

Yea I would check what alice-lnd.sphinx is logging out I was getting destination doesn't support AMP payments

you might need to run the test locally to see that log

[antonilol]

Yea I would check what alice-lnd.sphinx is logging out I was getting destination doesn't support AMP payments

you might need to run the test locally to see that log

i tried to reproduce the error, but it worked.
i will look through some logs to see where the ci fails and try that again

[antonilol]

found an amp test case in lnd! i will try to replicate this and hope it works

https://github.com/lightningnetwork/lnd/blob/master/lntest/itest/lnd_amp_test.go#L444-L453

[antonilol]

amp tests are working 884d86d

[antonilol]

i think everything works except queryRoutes, and when it fails other runs get cancelled.
when i run queryRoutes on my machine it fails no matter how much retries i give it, but if i restart the stack
docker-compose down docker-compose up -d docker wait sphinx-stack-relaysetup-1 sphinx-stack-lndsetup-1
and run the test again it works. will try this in the next commit for the workflow

[antonilol]

note that stakwork/sphinx-stack#33 has to be merged before this one

[antonilol]

integration-test (queryRoutes) constantly fails, i need some help with this one

[antonilol]

=> queryRoutes alice -> bob
alice success prob to bob: 0.95
=> queryRoutes alice -> carol
alice success prob to carol: 0.95
=> queryRoutes bob -> carol
  ✖ checkContacts Rejected promise returned by test
  ─

  checkContacts

  Rejected promise returned by test. Reason:

  StatusCodeError {
    error: {
      error: '2 UNKNOWN: unable to find a path to destination',
      success: false,
    },
    ...

alice has 2 1mil sat channels to bob and 2 1mil sat channels to carol
the direct way works, but from bob to carol (with alice as hop) doesnt seem to work but did before

[antonilol]

with the extra ln channel queryRoutes also succeeds

[kevkevinpal]

with the extra ln channel queryRoutes also succeeds

awesome it might have been an issue with opening multiple channels to the same node

[antonilol]

with the extra ln channel queryRoutes also succeeds

awesome it might have been an issue with opening multiple channels to the same node

i dont know

now the queryroutes only queries direct routes because of the 3rd channel, before this test case worked with an indirect path. it only succeeds because the indirect query is removed

[kevkevinpal]

one more thing we should do on stack and in the ampMessage test is to have a node that doesn't have amp enabled yet since lots of people who are using sphinx won't upgrade till the future so I was thinking having the node dave running but only having keysend enabled for him and testing to see if you're able to send a message or keysend payment to him still as a fall back if amp is not an option

[kevkevinpal]

with the extra ln channel queryRoutes also succeeds

awesome it might have been an issue with opening multiple channels to the same node

i dont know

now the queryroutes only queries direct routes because of the 3rd channel, before this test case worked with an indirect path. it only succeeds because the indirect query is removed

not sure I follow, what do you mean by direct route and indirect route?

[antonilol]

not sure I follow, what do you mean by direct route and indirect route?

first there was a channel from alice to bob and from alice to carol. alice has 2 direct routes to peers bob and carol

bob and carol have and indirect route (via alice), but now the third channel is between bob and carol, so they have a direct route now

[antonilol]

one more thing we should do on stack and in the ampMessage test is to have a node that doesn't have amp enabled yet since lots of people who are using sphinx won't upgrade till the future so I was thinking having the node dave running but only having keysend enabled for him and testing to see if you're able to send a message or keysend payment to him still as a fall back if amp is not an option

we can disable amp on carol since he only routes the payment between alice and bob

[antonilol]

alice only sent htlcs to bob and none to carol, the amounts dont even add up to 1.5 mil, so trying with more timeout (8af831c)

                ...
                {
                    "incoming": false,
                    "amount": "750000",
                    "hash_lock": "822f2f6ac9e025b51ddbbc454383c8ff760cb4b69f0c94500a9a43101688ba86",
                    "expiration_height": 322,
                    "htlc_index": "1",
                    "forwarding_channel": "0",
                    "forwarding_htlc_index": "0"
                },
                {
                    "incoming": false,
                    "amount": "187500",
                    "hash_lock": "56d97bfffb9ae51f827e305ec66ba54dab4477b71ceff3fc76316548805339f9",
                    "expiration_height": 322,
                    "htlc_index": "2",
                    "forwarding_channel": "0",
                    "forwarding_htlc_index": "0"
                },
                {
                    "incoming": false,
                    "amount": "35156",
                    "hash_lock": "bc7f3b189bc78aa7d092390f34d0e7593fe1d646862e3edd3beb2b27b248aaba",
                    "expiration_height": 322,
                    "htlc_index": "3",
                    "forwarding_channel": "0",
                    "forwarding_htlc_index": "0"
                }
                ...

[kevkevinpal]

alice only sent htlcs to bob and none to carol, the amounts dont even add up to 1.5 mil, so trying with more timeout (8af831c)

Do you know if nodes that do not have amp enabled can route amp shards? If that's the case we may need another node to test the keysend portion

[antonilol]

alice only sent htlcs to bob and none to carol, the amounts dont even add up to 1.5 mil, so trying with more timeout (8af831c)

Do you know if nodes that do not have amp enabled can route amp shards? If that's the case we may need another node to test the keysend portion

for a node to send AMPs, the node must have support for it, to receive it it must have support and accept-amp=true, for a router node AMPs look no different than other HTLCs and accept and route them without special flags/support

[antonilol]

well well, i knew it it was a routing problem. by setting a large delay (i did 5 minutes) the LNDs get time enough to know about eachother's channels. this would probably also fix the one with queryRoutes on an indirect path (carol -> alice -> bob)

[kevkevinpal]

well well, i knew it it was a routing problem. by setting a large delay (i did 5 minutes) the LNDs get time enough to know about eachother's channels. this would probably also fix the one with queryRoutes on an indirect path (carol -> alice -> bob)

Ok weird lol but it makes sense, I guess it takes a bit for the channel gossip to get out to the network. But the tests passing are a good thing

[antonilol]

I will clean up the code if there are some useless comments/placeholders/console logs and clean up this whole commit mess with a few force pushes

[kevkevinpal]

I will clean up the code if there are some useless comments/placeholders/console logs and clean up this whole commit mess with a few force pushes

Sounds good and we still need to add a sendPayment in the amp test to check to see if keysend works to Carol

[antonilol]

hmmm still some failing checks... will take some more time debugging

[antonilol]

all tests pass except 2 which are caused by stakwork/sphinx-stack#47, and 1 that is fixed by #445 and probably caused by other changes not updating the warning count

i think i can say that all technical stuff works now regarding AMP payments with sphinx relay

@kevkevinpal and @Evanfeenstra can you review this

there is one major backwards compatibility issue:
when a payment is received, only if inv.is_keysend the content will be parsed as sphinx message (src/grpc/subscribe.ts:34), i had to change this because amp payments are not keysend. but this means non updated relays wont see amp payments as messages but as regular 3 sat payment. the keysend fallback will only work if their lnd does not accept amp, because only then an error over lightning is sent back.
this issue can be solved by adding an extra if that checks if some date has passed, a hardcoded date from when we think all nodes have upgraded to at least receive sphinx amp messages. i think setting this date to 6 months in the future will be enough and spamming planet sphinx with 'guys upgrade your relay' of course :)

btw, i was able to fix the amp proxy issue (bob did not accept keysend, and good i did test this because the virtualnodes could not send anything to bob). this brought me to another issue: rpc_proxy (and maybe proxy itself) doesnt support amp yet (so only send keysends)
the function that sends the payment basically looks like this:

if greenlight {
  send keysend
} else {
  if proxy {
    send keysend
  } else {
    send amp, if that fails send keysend
  }
}

[antonilol]

rebased

[antonilol]

the tests used to run successful here, i only rebased (no new changes) since then, do you know of changes (on the master branch) that might have caused these tests to fail?
are there any plans on when/how to introduce this change? i outlined some problems in this comment (mainly backwards compatibility)