lotus/paych/paych.go
2019-09-16 20:08:24 +02:00

298 lines
6.8 KiB
Go

package paych
import (
"context"
"fmt"
"math"
"strconv"
logging "github.com/ipfs/go-log"
"go.uber.org/fx"
"github.com/filecoin-project/go-lotus/chain/actors"
"github.com/filecoin-project/go-lotus/chain/address"
"github.com/filecoin-project/go-lotus/chain/stmgr"
"github.com/filecoin-project/go-lotus/chain/types"
"github.com/filecoin-project/go-lotus/node/impl/full"
)
var log = logging.Logger("paych")
type ManagerApi struct {
fx.In
full.MpoolAPI
full.WalletAPI
full.ChainAPI
}
type Manager struct {
store *Store
sm *stmgr.StateManager
mpool full.MpoolAPI
wallet full.WalletAPI
chain full.ChainAPI
}
func NewManager(sm *stmgr.StateManager, pchstore *Store, api ManagerApi) *Manager {
return &Manager{
store: pchstore,
sm: sm,
mpool: api.MpoolAPI,
wallet: api.WalletAPI,
chain: api.ChainAPI,
}
}
func maxLaneFromState(st *actors.PaymentChannelActorState) (uint64, error) {
maxLane := uint64(math.MaxUint64)
for lane := range st.LaneStates {
ilane, err := strconv.ParseUint(lane, 10, 64)
if err != nil {
return 0, err
}
if ilane+1 > maxLane+1 {
maxLane = ilane
}
}
return maxLane, nil
}
func (pm *Manager) TrackInboundChannel(ctx context.Context, ch address.Address) error {
_, st, err := pm.loadPaychState(ctx, ch)
if err != nil {
return err
}
maxLane, err := maxLaneFromState(st)
if err != nil {
return err
}
return pm.store.TrackChannel(&ChannelInfo{
Channel: ch,
Control: st.To,
Target: st.From,
Direction: DirInbound,
NextLane: maxLane + 1,
})
}
func (pm *Manager) loadOutboundChannelInfo(ctx context.Context, ch address.Address) (*ChannelInfo, error) {
_, st, err := pm.loadPaychState(ctx, ch)
if err != nil {
return nil, err
}
maxLane, err := maxLaneFromState(st)
if err != nil {
return nil, err
}
return &ChannelInfo{
Channel: ch,
Control: st.From,
Target: st.To,
Direction: DirOutbound,
NextLane: maxLane + 1,
}, nil
}
func (pm *Manager) TrackOutboundChannel(ctx context.Context, ch address.Address) error {
ci, err := pm.loadOutboundChannelInfo(ctx, ch)
if err != nil {
return err
}
return pm.store.TrackChannel(ci)
}
func (pm *Manager) ListChannels() ([]address.Address, error) {
return pm.store.ListChannels()
}
func (pm *Manager) GetChannelInfo(addr address.Address) (*ChannelInfo, error) {
return pm.store.getChannelInfo(addr)
}
// checks if the given voucher is valid (is or could become spendable at some point)
func (pm *Manager) CheckVoucherValid(ctx context.Context, ch address.Address, sv *types.SignedVoucher) error {
act, pca, err := pm.loadPaychState(ctx, ch)
if err != nil {
return err
}
// verify signature
vb, err := sv.SigningBytes()
if err != nil {
return err
}
// TODO: technically, either party may create and sign a voucher.
// However, for now, we only accept them from the channel creator.
// More complex handling logic can be added later
if err := sv.Signature.Verify(pca.From, vb); err != nil {
return err
}
sendAmount := sv.Amount
// now check the lane state
// TODO: should check against vouchers in our local store too
// there might be something conflicting
ls, ok := pca.LaneStates[fmt.Sprint(sv.Lane)]
if !ok {
} else {
if ls.Closed {
return fmt.Errorf("voucher is on a closed lane")
}
if ls.Nonce >= sv.Nonce {
return fmt.Errorf("nonce too low")
}
sendAmount = types.BigSub(sv.Amount, ls.Redeemed)
}
// TODO: also account for vouchers on other lanes we've received
newTotal := types.BigAdd(sendAmount, pca.ToSend)
if types.BigCmp(act.Balance, newTotal) < 0 {
return fmt.Errorf("not enough funds in channel to cover voucher")
}
if len(sv.Merges) != 0 {
return fmt.Errorf("dont currently support paych lane merges")
}
return nil
}
// checks if the given voucher is currently spendable
func (pm *Manager) CheckVoucherSpendable(ctx context.Context, ch address.Address, sv *types.SignedVoucher, secret []byte, proof []byte) (bool, error) {
owner, err := pm.getPaychOwner(ctx, ch)
if err != nil {
return false, err
}
if sv.Extra != nil && proof == nil {
known, err := pm.ListVouchers(ctx, ch)
if err != nil {
return false, err
}
for _, v := range known {
if v.Proof != nil && v.Voucher.Equals(sv) {
log.Info("CheckVoucherSpendable: using stored proof")
proof = v.Proof
break
}
}
if proof == nil {
log.Warn("CheckVoucherSpendable: nil proof for voucher with validation")
}
}
enc, err := actors.SerializeParams(&actors.PCAUpdateChannelStateParams{
Sv: *sv,
Secret: secret,
Proof: proof,
})
if err != nil {
return false, err
}
ret, err := pm.sm.Call(ctx, &types.Message{
From: owner,
To: ch,
Method: actors.PCAMethods.UpdateChannelState,
Params: enc,
}, nil)
if err != nil {
return false, err
}
if ret.ExitCode != 0 {
return false, nil
}
return true, nil
}
func (pm *Manager) loadPaychState(ctx context.Context, ch address.Address) (*types.Actor, *actors.PaymentChannelActorState, error) {
var pcast actors.PaymentChannelActorState
act, err := pm.sm.LoadActorState(ctx, ch, &pcast)
if err != nil {
return nil, nil, err
}
return act, &pcast, nil
}
func (pm *Manager) getPaychOwner(ctx context.Context, ch address.Address) (address.Address, error) {
ret, err := pm.sm.Call(ctx, &types.Message{
From: ch,
To: ch,
Method: actors.PCAMethods.GetOwner,
}, nil)
if err != nil {
return address.Undef, err
}
if ret.ExitCode != 0 {
return address.Undef, fmt.Errorf("failed to get payment channel owner (exit code %d)", ret.ExitCode)
}
return address.NewFromBytes(ret.Return)
}
func (pm *Manager) AddVoucher(ctx context.Context, ch address.Address, sv *types.SignedVoucher, proof []byte) error {
if err := pm.CheckVoucherValid(ctx, ch, sv); err != nil {
return err
}
return pm.store.AddVoucher(ch, sv, proof)
}
func (pm *Manager) AllocateLane(ch address.Address) (uint64, error) {
return pm.store.AllocateLane(ch)
}
func (pm *Manager) ListVouchers(ctx context.Context, ch address.Address) ([]*VoucherInfo, error) {
// TODO: just having a passthrough method like this feels odd. Seems like
// there should be some filtering we're doing here
return pm.store.VouchersForPaych(ch)
}
func (pm *Manager) OutboundChanTo(from, to address.Address) (address.Address, error) {
pm.store.lk.Lock()
defer pm.store.lk.Unlock()
return pm.store.findChan(func(ci *ChannelInfo) bool {
if ci.Direction != DirOutbound {
return false
}
return ci.Control == from && ci.Target == to
})
}
func (pm *Manager) NextNonceForLane(ctx context.Context, ch address.Address, lane uint64) (uint64, error) {
vouchers, err := pm.store.VouchersForPaych(ch)
if err != nil {
return 0, err
}
var maxnonce uint64
for _, v := range vouchers {
if v.Voucher.Lane == lane {
if v.Voucher.Nonce > maxnonce {
maxnonce = v.Voucher.Nonce
}
}
}
return maxnonce + 1, nil
}