nwaku/waku/v2/protocol/waku_swap/waku_swap.nim

268 lines
9.1 KiB
Nim

## SWAP implements Accounting for Waku. See
## https://github.com/vacp2p/specs/issues/24 for more.
##
## This is based on the SWAP based approach researched by the Swarm team, and
## can be thought of as an economic extension to Bittorrent's tit-for-tat
## economics.
##
## It is quite suitable for accounting for imbalances between peers, and
## specifically for something like the Store protocol.
##
## It is structured as follows:
##
## 1) First a handshake is made, where terms are agreed upon
##
## 2) Then operation occurs as normal with HistoryRequest, HistoryResponse etc
## through store protocol (or otherwise)
##
## 3) When payment threshhold is met, a cheque is sent. This acts as promise to
## pay. Right now it is best thought of as karma points.
##
## Things like settlement is for future work.
##
import
std/[tables, options, json],
bearssl,
chronos, chronicles, metrics, stew/results,
libp2p/crypto/crypto,
libp2p/protocols/protocol,
libp2p/protobuf/minprotobuf,
libp2p/stream/connection,
../../node/peer_manager/peer_manager,
../message_notifier,
./waku_swap_types,
../../waku/v2/protocol/waku_swap/waku_swap_contracts
export waku_swap_types
declarePublicGauge waku_swap_peers, "number of swap peers"
declarePublicGauge waku_swap_errors, "number of swap protocol errors", ["type"]
logScope:
topics = "wakuswap"
const WakuSwapCodec* = "/vac/waku/swap/2.0.0-beta1"
# Error types (metric label values)
const
dialFailure = "dial_failure"
decodeRpcFailure = "decode_rpc_failure"
# Serialization
# -------------------------------------------------------------------------------
proc encode*(handshake: Handshake): ProtoBuffer =
result = initProtoBuffer()
result.write(1, handshake.beneficiary)
proc encode*(cheque: Cheque): ProtoBuffer =
result = initProtoBuffer()
result.write(1, cheque.beneficiary)
result.write(2, cheque.date)
result.write(3, cheque.amount)
result.write(4, cheque.signature)
proc init*(T: type Handshake, buffer: seq[byte]): ProtoResult[T] =
var beneficiary: seq[byte]
var handshake = Handshake()
let pb = initProtoBuffer(buffer)
discard ? pb.getField(1, handshake.beneficiary)
ok(handshake)
proc init*(T: type Cheque, buffer: seq[byte]): ProtoResult[T] =
var beneficiary: seq[byte]
var date: uint32
var amount: uint32
var signature: seq[byte]
var cheque = Cheque()
let pb = initProtoBuffer(buffer)
discard ? pb.getField(1, cheque.beneficiary)
discard ? pb.getField(2, cheque.date)
discard ? pb.getField(3, cheque.amount)
discard ? pb.getField(4, cheque.signature)
ok(cheque)
# Accounting
# -------------------------------------------------------------------------------
#
# We credit and debits peers based on what for now is a form of Karma asset.
# TODO Test for credit/debit operations in succession
# TODO Assume we calculated cheque
proc sendCheque*(ws: WakuSwap) {.async.} =
let peerOpt = ws.peerManager.selectPeer(WakuSwapCodec)
if peerOpt.isNone():
error "no suitable remote peers"
waku_swap_errors.inc(labelValues = [dialFailure])
return
let peer = peerOpt.get()
let connOpt = await ws.peerManager.dialPeer(peer, WakuSwapCodec)
if connOpt.isNone():
# @TODO more sophisticated error handling here
error "failed to connect to remote peer"
waku_swap_errors.inc(labelValues = [dialFailure])
return
info "sendCheque"
# TODO We get this from the setup of swap setup, dynamic, should be part of setup
# TODO Add beneficiary, etc
var aliceSwapAddress = "0x6C3d502f1a97d4470b881015b83D9Dd1062172e1"
var signature: string
var res = waku_swap_contracts.signCheque(aliceSwapAddress)
if res.isOk():
info "signCheque ", res=res[]
let json = res[]
signature = json["signature"].getStr()
else:
# To test code paths, this should look different in a production setting
warn "Something went wrong when signing cheque, sending anyway"
info "Signed Cheque", swapAddress = aliceSwapAddress, signature = signature
let sigBytes = cast[seq[byte]](signature)
await connOpt.get().writeLP(Cheque(amount: 1, signature: sigBytes).encode().buffer)
# Set new balance
let peerId = peer.peerId
ws.accounting[peerId] -= 1
info "New accounting state", accounting = ws.accounting[peerId]
# TODO Authenticate cheque, check beneficiary etc
proc handleCheque*(ws: WakuSwap, cheque: Cheque) =
info "handle incoming cheque"
# XXX Assume peerId is first peer
let peerOpt = ws.peerManager.selectPeer(WakuSwapCodec)
let peerId = peerOpt.get().peerId
# TODO Redeem cheque here
var signature = cast[string](cheque.signature)
# TODO Where should Alice Swap Address come from? Handshake probably?
# Hacky for now
var aliceSwapAddress = "0x6C3d502f1a97d4470b881015b83D9Dd1062172e1"
info "Redeeming cheque with", swapAddress=aliceSwapAddress, signature=signature
var res = waku_swap_contracts.redeemCheque(aliceSwapAddress, signature)
if res.isOk():
info "redeemCheque ok", redeem=res[]
else:
info "Unable to redeem cheque"
# Check balance here
# TODO How do we get ERC20 address here?
# XXX This one is wrong
# Normally this would be part of initial setup, otherwise we need some temp persistence here
# Possibly as part of handshake?
var erc20address = "0x6C3d502f1a97d4470b881015b83D9Dd1062172e1"
let balRes = waku_swap_contracts.getERC20Balances(erc20address)
if balRes.isOk():
# XXX: Assumes Alice and Bob here...
var bobBalance = balRes[]["bobBalance"].getInt()
info "New balance is", balance = bobBalance
else:
info "Problem getting Bob balance"
# TODO Could imagine scenario where you don't cash cheque but leave it as credit
# In that case, we would probably update accounting state, but keep track of cheques
# When this is true we update accounting state anyway when node is offline,
# makes waku_swap test pass for now
# Consider desired logic here
var stateUpdateOverRide = true
if res.isOk():
info "Updating accounting state with redeemed cheque"
ws.accounting[peerId] += int(cheque.amount)
else:
if stateUpdateOverRide:
info "Updating accounting state with even if cheque failed"
ws.accounting[peerId] += int(cheque.amount)
else:
info "Not updating accounting state with due to bad cheque"
info "New accounting state", accounting = ws.accounting[peerId]
proc init*(wakuSwap: WakuSwap) =
info "wakuSwap init 1"
proc handle(conn: Connection, proto: string) {.async, gcsafe, closure.} =
info "swap handle incoming connection"
var message = await conn.readLp(64*1024)
# XXX This can be handshake, etc
var res = Cheque.init(message)
if res.isErr:
error "failed to decode rpc"
waku_swap_errors.inc(labelValues = [decodeRpcFailure])
return
info "received cheque", value=res.value
wakuSwap.handleCheque(res.value)
proc credit(peerId: PeerId, n: int) {.gcsafe, closure.} =
info "Crediting peer: ", peer=peerId, amount=n
if wakuSwap.accounting.hasKey(peerId):
wakuSwap.accounting[peerId] -= n
else:
wakuSwap.accounting[peerId] = -n
info "Accounting state", accounting = wakuSwap.accounting[peerId]
wakuSwap.applyPolicy(peerId)
# TODO Debit and credit here for Karma asset
proc debit(peerId: PeerId, n: int) {.gcsafe, closure.} =
info "Debiting peer: ", peer=peerId, amount=n
if wakuSwap.accounting.hasKey(peerId):
wakuSwap.accounting[peerId] += n
else:
wakuSwap.accounting[peerId] = n
info "Accounting state", accounting = wakuSwap.accounting[peerId]
wakuSwap.applyPolicy(peerId)
proc applyPolicy(peerId: PeerId) {.gcsafe, closure.} =
# TODO Separate out depending on if policy is soft (accounting only) mock (send cheque but don't cash/verify) hard (actually send funds over testnet)
#Check if the Disconnect Threshold has been hit. Account Balance nears the disconnectThreshold after a Credit has been done
if wakuSwap.accounting[peerId] <= wakuSwap.disconnectThreshold:
warn "Disconnect threshhold has been reached: ", threshold=wakuSwap.disconnectThreshold, balance=wakuSwap.accounting[peerId]
else:
info "Disconnect threshhold not hit"
#Check if the Payment threshold has been hit. Account Balance nears the paymentThreshold after a Debit has been done
if wakuSwap.accounting[peerId] >= wakuSwap.paymentThreshold:
warn "Payment threshhold has been reached: ", threshold=wakuSwap.paymentThreshold, balance=wakuSwap.accounting[peerId]
#In soft phase we don't send cheques yet
#discard wakuSwap.sendCheque()
else:
info "Payment threshhold not hit"
wakuSwap.handler = handle
wakuSwap.codec = WakuSwapCodec
wakuSwap.credit = credit
wakuSwap.debit = debit
wakuswap.applyPolicy = applyPolicy
# TODO Expression return?
proc init*(T: type WakuSwap, peerManager: PeerManager, rng: ref BrHmacDrbgContext): T =
info "wakuSwap init 2"
new result
result.rng = rng
result.peerManager = peerManager
result.accounting = initTable[PeerId, int]()
result.text = "test"
result.paymentThreshold = 100
result.disconnectThreshold = -100
result.init()
proc setPeer*(ws: WakuSwap, peer: PeerInfo) =
ws.peerManager.addPeer(peer, WakuSwapCodec)
waku_swap_peers.inc()
# TODO End to end communication