Commit Graph

87 Commits

Author SHA1 Message Date
Johan T. Halseth
5d03256baf
htlcswith/link: resend fundingLocked from channelLink when numUpdates == 0.
In the case where the channelLink get started and the number of
updates on this channel is zero, this means no paymenys has been
done using this channel. This might mean that the fundingLocked
never was sent successfully, so we resend to make sure this
channel gets opened correctly.
2017-10-02 13:29:50 +02:00
Olaoluwa Osuntokun
7ae436e30e
htlcswitch+test: send switch back error on lnwallet.ErrInsufficientBalance
This commit fixes a bug related to swallowing an error that should go
to the switch in the case of an insufficient balance error when
attempting to add a new HTLC to the channel state machine. In this
case, an error would never be returned back to the client/switch, and
the internal processing within the channelLink would loop forever,
attempting to add an HTLC that can’t be added due to insufficient
balance to state machine itself.

We fix this issue by only treating the lnwallet.ErrMaxHTLCNumber as the
only error that prompts adding an HTLC to the overflow queue rather
than sending the error directly back to the switch.
2017-09-25 16:10:20 -07:00
Olaoluwa Osuntokun
be5b2d46a5
htlcswitch: ensure the packetQueue can handle total+partial commitment overflows
In this commit, we’ve moved away from the internal queryHandler within
the packetQueue entirely. We now use an internal queueLen variable
internally to allow callers to sample the queue’s size, and also for
synchronization purposes internally.

This commit also introduces a chan struct{} (freeSlots) that is used
internally as a semaphore. The current value of freeSlots reflects the
number of available slots within the commitment transaction. Within the
link, after an HTLC has been removed/modified, then a “slot” is freed
up. The main packetConsumer then interprets these messages as a signal
to attempt to free up a new slot within the queue itself by dumping off
to the commitment transaction.
2017-09-25 12:47:34 -07:00
Olaoluwa Osuntokun
64317c04f1
htlcswitch: use atomic integer to track link bandwidth internally
This commit modifies the way the bandwidth of a given channel link is
tracked, and reported externally. The prior approach pushed most of the
logic for tracking channel bandwidth into the link itself, and relied
on a report from the queue in order to determine the total available
bandwidth. This approach at times could inadvertently introduce
deadlocks when working on new features as since the query was handled
internally, it required the link to be _active_ and non-blocked in
order to respond to.

We’ve now abandoned this approach in favor of lifting the bandwidth
accounting to the highest possible abstraction layer within the link
itself. We now maintain a availableBandwidth integer that’s used
atomically within the link in response to: us adding+settling an HTLC,
and the remote party failing one of our HTLC’s.
2017-09-25 12:31:59 -07:00
Olaoluwa Osuntokun
457aebd16f
htlcswitch: ensure channel state machine is stopped on link stoppage 2017-09-22 15:56:12 -07:00
Olaoluwa Osuntokun
6f5ef249e4
htlcswitch: re-write link's packet overflow queue for readability+extensibility
This commit completes a full re-write of the link’s packet overflow
queue with the goals of the making the code itself more understandable
and also allowing it to be more extensible in the future with various
algorithms for handling HTLC congestion avoidance and persistent queue
back pressure.

The new design is simpler and consumes much less coroutines (no longer
a new goroutine for each active HLTC). We now implement a simple
synchronized queue using a standard condition variable.
2017-09-22 15:54:16 -07:00
Conner Fromknecht
74322a99be config+htlclink+peer: htlc hodl mode!
This commit adds a new debug mode for lnd
  called hodlhtlc. This mode instructs a node
  to refrain from settling incoming HTLCs for
  which it is the exit node. We plan to use
  this in testing to more precisely control
  the states a node can take during
  execution.
2017-09-19 11:31:52 -07:00
Olaoluwa Osuntokun
bf071c1985
htlcswitch: properly verify OutgoingCTLV+Timeout when final hop in link
This commit fixes an existing bug in the way we perform validation of
the timelock information as the final hop in the route. Previously, we
would assert that the outgoing time lock in the per-hop payload would
exactly match our time lock delta.

Instead, we should be asserting two things:
   1. That the time lock in the payload is >= the expected time lock
   2. That timeout on the HTLC is exactly equal to the payload
2017-09-12 22:04:59 +02:00
Olaoluwa Osuntokun
475c3b6c0c
htlcswitch: accept over-paid HTLC's fee-wise
This commit modifies fee acceptance logic to allow remote nodes to
*over pay* for the HTLC’s sent.
2017-08-22 00:53:20 -07:00
Olaoluwa Osuntokun
4d92d23762
htlcswitch: add new UpdateForwardingPolicies method
This commit adds a new method to the HtlcSwitch:
UpdateForwardingPolicies. With this method callers are now able to
modify the forwarding policies of all, or some currently active links.
We also make a slight modification to the way that forwarding policy
updates are handled within the links themselves to ensure that we don’t
override with a zero value for any of the fields.
2017-08-22 00:53:18 -07:00
Olaoluwa Osuntokun
8a51b1a0c6
Htlcswitch: switch all accounting and forwarding decisions to use mSAT's 2017-08-22 00:53:04 -07:00
Olaoluwa Osuntokun
572eef2840
htlcswitch: add channel point prefix to HTLC examine logs 2017-08-15 17:55:06 -07:00
Olaoluwa Osuntokun
cdb7436e34
htlcswitch: update tests to account for new HTLC expiry observence 2017-08-02 21:11:40 -07:00
Olaoluwa Osuntokun
ee1acb1610
htlcswitch: reject HTLC's which expire too soon
This commit implements a missing policy within the current ChannelLink
interface. If an HTLC arrives that is too close to the current block
height, then we’ll reject it. As otherwise, it may be possible for us
to lose an on-chain claim if they HTLC expires already or expires
before we’re able to get a commitment transaction in the chain.

As the exit node, we have a grace period that governs out decision. As
an intermediate node, we ensure that the HTLC isn’t close to expiry on
our outgoing link end if we forward it.
2017-08-02 21:10:43 -07:00
Olaoluwa Osuntokun
8eadd09403
htlcswitch: add additional logging statement when forwarding HTLC's 2017-07-30 17:52:25 -07:00
Olaoluwa Osuntokun
2d1a598b66
htlcswitch: modify channelLink to use new create+verify commitment API 2017-07-30 17:51:16 -07:00
Olaoluwa Osuntokun
f7c4237686
htlcswitch: remove initial revocation window extension in channelLink
We can safely remove the initial revocation window extension as this
has gone away with the new state machine. We instead now just fill the
window once the channel has been opened, and then maintain a fixed
window size of 2 from there on.
2017-07-30 17:51:13 -07:00
Olaoluwa Osuntokun
a04fa76a4c
lnwire+htlcswitch: minor grammatical, formatting fixes after error PR 2017-07-14 20:08:37 -07:00
Andrey Samokhvalov
2d378b3280 htlcswitch+router: add onion error obfuscation
Within the network, it's important that when an HTLC forwarding failure
occurs, the recipient is notified in a timely manner in order to ensure
that errors are graceful and not unknown. For that reason with
accordance to BOLT №4 onion failure obfuscation have been added.
2017-07-14 19:08:04 -07:00
Andrey Samokhvalov
ef73062c14 peer+server+htlcswitch: add reason to disconnnect function
In order to recognize exact reason of the disconnect the additional
field have been added in the disconnect function.
2017-07-14 19:08:04 -07:00
Johan T. Halseth
f4db249cb8 htlcswitch: handle update_fee message received from peer.
This commit makes the channellink update a channel's fee
if an update_fee message is received from the peer.
2017-07-14 16:39:15 -07:00
Olaoluwa Osuntokun
01d54c29af
htlcswitch: restore the ability to properly handle debughtlc recv's
This commit fixes a regression introduce in the prior commit which
added full verification of the per-hop payloads to the ChannelLink
interface. When this was initially implemented, the added checks
weren’t guarded on the existence of debughtlc’s. As a result,
debughtlc’s would be rejected as they don’t match the expected invoice
value.

This commit fixes that issue by only checking the hop payload if debug
HTLC mode isn’t on.
2017-07-04 15:58:23 -07:00
Olaoluwa Osuntokun
4b0e331c62
htlcswitch: fix linter issues 2017-06-17 01:04:21 +02:00
Olaoluwa Osuntokun
399d193e2c
htlcswitch: add a new UpdateFeePolicy to ChannelLink interface
This commit adds a new method to the ChannelLink interface which is
meant to allow outside sub-system to update the forwarding policy of a
channel. This can be triggered either by a new RPC method, or
automatically by some sort of control system which seeks to optimize
fee revenue, or block off channels, etc.
2017-06-17 00:01:10 +02:00
Olaoluwa Osuntokun
cd10dc712f
htlcswitch: implement full HTLC onion payload validation logic
This commit puts a missing piece in place by properly parsing and
validating the per hop payload received in incoming HTLC’s. When
forwarding HTLC’s we ensure that the payload recovered is consistent
with our current forwarding policy. Additionally, when we’re the “exit
node” for a payment, then we ensure that the HTLC extended matches up
with our expectation w.r.t the payment amount to be received.
2017-06-16 23:58:08 +02:00
Olaoluwa Osuntokun
ea57a94c2e
htlcswitch: add a ShortChanID method to the ChannelLink interface 2017-06-16 23:32:47 +02:00
Olaoluwa Osuntokun
058e641d7e
htlcswitch: add new ForwardingPolicy struct guide forwarding decisions 2017-06-16 23:31:00 +02:00
Olaoluwa Osuntokun
2ab03c57be
htlcswitch: re-introduce dynamic commitment log tick timer
This commit fixes a slight regression in the logic of the switch by
ensuring that the log commitment timer is only start _after_ we receive
a new commitment signature. Otherwise, the ticker will keep ticking and
possibly settle HTLC’s that’ve yet to be locked in, or waste a
signature causing us to be deprived of a revocation which is required
for us to initiate a new state transition.

Additionally, the commit performs a few minor post-merge clean ups.
2017-05-31 16:43:48 -07:00
Andrey Samokhvalov
a5d90b9ad1 htlcswitch: fix last-mile settle stalling in concurrent multi-hop setting
This commit fixes an issue that would at times cause the htlcManager
which manages the link that’s the final hop to settle in an HTLC flow.
Previously, a case would arise wherein a set of HTLC’s were settled to,
but not properly committed to in the commitment transaction of the
remote node. This wasn’t an issue with HTLC’s which were added but
uncleared, as that batch was tracked independently.

In order to fix this issue, we now track pending HTLC settles
independently. This is a temporary fix, as has been noted in a TODO
within this commit.
2017-05-31 11:06:08 -07:00
Andrey Samokhvalov
7595bee27c htlcswitch: add usage of queue in channel link
In this commit usage of the pending packet queue have been added.
This queue will consume the downstream packets if state machine return
the error that we do not have enough capacity for htlc in commitment
transaction. Upon receiving settle/fail payment descriptors - add htlc
have been removed, we release the slot, and process pending add htlc
requests.
2017-05-31 11:06:08 -07:00
Andrey Samokhvalov
a14f25830e htlcswitch: remove redudant variables
Because processing of onion blob have been moved in another place we
could get rid of the variables which are not needed any more.

NOTE: pendingBatch have been replaced with batchCounter variable, but
it should be removed at all, because number of pending batch updates
might be counted by the state machine itself.
2017-05-31 11:06:08 -07:00
Andrey Samokhvalov
0e2209cb12 htlcswitch: move onion blob processing
Step №4 in making htlcManager (aka channelLink) testable:

This step consist of two:
1. Start using the hop iterator abstraction, the concrete
implementation of which will be added later, basically it will we the
same sphinx onion packet processor, but wrapped in hop iterator
abstraction.

2. The RevokAndAck processing part have been replaced by the
"processLockedInHtlcs" function which implement the same logic, but make
it a bit simpler.

Such changes will allow as to get rid of the the unnecessary variables.
2017-05-31 11:06:08 -07:00
Andrey Samokhvalov
de01721aed htlcswitch: add hop iterator
Short: such abstraction give as ability to test the channel link in the
future.

Long: hop iterator represents the entity which is be able to give payment
route hop by hop. This interface will be used to have an abstraction
over the algorithm which we use to determine the next hope in htlc route
and also helps the unit test to create mock representation of such
algorithm which uses simple array of hops.
2017-05-31 11:06:08 -07:00
Andrey Samokhvalov
db30571efe htlcswitch: start using config in channel link
Step №3 in making htlcManager (aka channelLink) testable:
Apply the channel link config inside the channel link itself.
2017-05-31 11:06:08 -07:00
Andrey Samokhvalov
2eea76375c htlcswitch: make channel link implements interface
Step №2 in making htlcManager (aka channelLink) testable:
Implement the ChannelLink interface which is needed to use it in pair
with htlc switch. With this commit channel link impelements interface,
but isn't able to operate properly yet.
2017-05-31 11:06:08 -07:00
Andrey Samokhvalov
7f572fc155 htlcswitch: add channel link config
Step №1 in making htlcManager (aka channelLink) testable:
Start use config which will allow as mock/stub external subsystems.
2017-05-31 11:06:08 -07:00
Andrey Samokhvalov
0de4ea2712 htlcswitch: copy the initial representation of htlc manager
In this commit all initial code which will be transformed into channel
link have been added. Rather than changing the in the same commit is
better to create the standalone commit, in order to see the changes
which have been applied to relocated code.
2017-05-31 11:06:08 -07:00