Swap Bounced Cheque Verification Process

contracts/swap/factory.go

@@ -9,7 +9,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/accounts/abi/bind"
 	"github.com/ethereum/go-ethereum/common"
-	chequebookFactory "github.com/ethersphere/go-sw3/contracts-v0-2-0/simpleswapfactory"
+	chequebookFactory "github.com/ethersphere/go-sw3/contracts-v0-2-3/simpleswapfactory"
 	"github.com/ethersphere/swarm/swap/chain"
 )
 

contracts/swap/swap.go

@@ -26,7 +26,7 @@ import (
 	"github.com/ethereum/go-ethereum/accounts/abi/bind"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
-	contract "github.com/ethersphere/go-sw3/contracts-v0-2-0/erc20simpleswap"
+	contract "github.com/ethersphere/go-sw3/contracts-v0-2-3/erc20simpleswap"
 	"github.com/ethersphere/swarm/swap/chain"
 	"github.com/ethersphere/swarm/swap/int256"
 )
@@ -53,6 +53,8 @@ type Contract interface {
 	Issuer(opts *bind.CallOpts) (common.Address, error)
 	// PaidOut returns the total paid out amount for the given address
 	PaidOut(opts *bind.CallOpts, addr common.Address) (*big.Int, error)
+	// Bounced returns if there has been a bounced cheque from the chequebook
+	Bounced(opts *bind.CallOpts) (bool, error)
 }
 
 // CashChequeResult summarizes the result of a CashCheque or CashChequeBeneficiary call
@@ -91,6 +93,12 @@ func InstanceAt(address common.Address, backend chain.Backend) (Contract, error)
 	return c, err
 }
 
+// Bounced returns the boolean indicating if a cheque attempted to be cashed has been bounced it in the receiver contract
+// Once its bounced, it will not change it's state again, unless re deployed.
+func (s simpleContract) Bounced(opts *bind.CallOpts) (bool, error) {
+	return s.instance.Bounced(opts)
+}
+
 // Withdraw withdraws amount from the chequebook and blocks until the transaction is mined
 func (s simpleContract) Withdraw(auth *bind.TransactOpts, amount *big.Int) (*types.Receipt, error) {
 	tx, err := s.instance.Withdraw(auth, amount)

go.mod

@@ -18,7 +18,7 @@ require (
 	github.com/docker/go-connections v0.4.0 // indirect
 	github.com/docker/go-units v0.4.0 // indirect
 	github.com/ethereum/go-ethereum v1.9.2
-	github.com/ethersphere/go-sw3 v0.2.1
+	github.com/ethersphere/go-sw3 v0.2.3
 	github.com/fatih/color v1.7.0 // indirect
 	github.com/fjl/memsize v0.0.0-20180418122429-ca190fb6ffbc
 	github.com/go-kit/kit v0.9.0 // indirect

go.sum

@@ -68,6 +68,8 @@ github.com/ethereum/go-ethereum v1.9.2 h1:RMIHDO/diqXEgORSVzYx8xW9x2+S32PoAX5lQw
 github.com/ethereum/go-ethereum v1.9.2/go.mod h1:PwpWDrCLZrV+tfrhqqF6kPknbISMHaJv9Ln3kPCZLwY=
 github.com/ethersphere/go-sw3 v0.2.1 h1:+i660uWzhRbT1YO7MAeuxzn+jUeYOTc8rGRVjsKaw+4=
 github.com/ethersphere/go-sw3 v0.2.1/go.mod h1:HukT0aZ6QdW/d7zuD/0g5xlw6ewu9QeqHojxLDsaERQ=
+github.com/ethersphere/go-sw3 v0.2.3 h1:7fmXB26sDvwoWiQ2wA53x9GRhi5+hPn4mUTuClx7wPc=
+github.com/ethersphere/go-sw3 v0.2.3/go.mod h1:HukT0aZ6QdW/d7zuD/0g5xlw6ewu9QeqHojxLDsaERQ=
 github.com/evanphx/json-patch v4.2.0+incompatible/go.mod h1:50XU6AFN0ol/bzJsmQLiYLvXMP4fmwYFNcr97nuDLSk=
 github.com/fatih/color v1.7.0 h1:DkWD4oS2D8LGGgTQ6IvwJJXSL5Vp2ffcQg58nFV38Ys=
 github.com/fatih/color v1.7.0/go.mod h1:Zm6kSWBoL9eyXnKyktHP6abPY2pDugNf5KwzbycvMj4=

swap/common_test.go

@@ -18,7 +18,7 @@ import (
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/p2p"
 	"github.com/ethereum/go-ethereum/p2p/simulations/adapters"
-	contractFactory "github.com/ethersphere/go-sw3/contracts-v0-2-0/simpleswapfactory"
+	contractFactory "github.com/ethersphere/go-sw3/contracts-v0-2-3/simpleswapfactory"
 	cswap "github.com/ethersphere/swarm/contracts/swap"
 	"github.com/ethersphere/swarm/network"
 	"github.com/ethersphere/swarm/p2p/protocols"

swap/peer.go

@@ -72,6 +72,15 @@ func NewPeer(p *protocols.Peer, s *Swap, beneficiary common.Address, contractAdd
 		return nil, err
 	}
 
+	bouncedCheque := false
+	bouncedCheque, err = peer.hasBouncedCheque()
+	if err != nil {
+		return nil, err
+	}
+	if bouncedCheque {
+		return nil, ErrBouncedCheque
+	}
+
 	return peer, nil
 }
 
@@ -221,3 +230,20 @@ func (p *Peer) sendCheque() error {
 		Cheque: cheque,
 	})
 }
+
+// hasBouncedCheque returns the boolean indicating if a cheque attempted to be cashed has been bounced it in the receiver peer
+// Once its bounced, it will not change it's state again, unless re deployed.
+func (p *Peer) hasBouncedCheque() (bool, error) {
+	bouncedCheque := false
+	var err error
+
+	// if chequebook not defined don't call contract methods
+	if p.swap.contract != nil {
+		bouncedCheque, err = p.swap.contract.Bounced(nil)
+		if err != nil {
+			return false, err
+		}
+	}
+
+	return bouncedCheque, nil
+}

swap/protocol.go

@@ -39,6 +39,9 @@ var (
 	// structure of the HandshakeMsg
 	ErrInvalidHandshakeMsg = errors.New("invalid handshake message")
 
+	// ErrBouncedCheque is used when the peer has a bounced cheque and should be disconnected
+	ErrBouncedCheque = errors.New("bounced cheque detected")
+
 	// Spec is the swap protocol specification
 	Spec = &protocols.Spec{
 		Name:       "swap",

swap/protocol_test.go

@@ -548,8 +548,11 @@ func TestSwapRPC(t *testing.T) {
 	swap, clean := newTestSwap(t, ownerKey, nil)
 	defer clean()
 
+	depositAmount := int256.Uint256From(9000 * RetrieveRequestPrice)
+
 	// need to have a dummy contract or the call will fail at `GetParams` due to `NewAPI`
-	swap.contract, err = contract.InstanceAt(common.Address{}, swap.backend)
+	// deploy a chequebook due to bouncedCheque verification or it will fail
+	err = testDeploy(context.TODO(), swap, depositAmount)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -594,7 +597,7 @@ func TestSwapRPC(t *testing.T) {
 		t.Fatalf("Expected balance to be 0 but it is %d", balance)
 	}
 
-	peer1, err := swap.addPeer(dummyPeer1.Peer, common.Address{}, common.Address{})
+	peer1, err := swap.addPeer(dummyPeer1.Peer, common.Address{}, swap.GetParams().ContractAddress)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -603,7 +606,7 @@ func TestSwapRPC(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	peer2, err := swap.addPeer(dummyPeer2.Peer, common.Address{}, common.Address{})
+	peer2, err := swap.addPeer(dummyPeer2.Peer, common.Address{}, swap.GetParams().ContractAddress)
 	if err != nil {
 		t.Fatal(err)
 	}

swap/simulations_test.go

@@ -42,7 +42,7 @@ import (
 	"github.com/ethereum/go-ethereum/p2p/simulations"
 	"github.com/ethereum/go-ethereum/p2p/simulations/adapters"
 	"github.com/ethereum/go-ethereum/rpc"
-	contractFactory "github.com/ethersphere/go-sw3/contracts-v0-2-0/simpleswapfactory"
+	contractFactory "github.com/ethersphere/go-sw3/contracts-v0-2-3/simpleswapfactory"
 	cswap "github.com/ethersphere/swarm/contracts/swap"
 	"github.com/ethersphere/swarm/network/simulation"
 	"github.com/ethersphere/swarm/p2p/protocols"

swap/swap.go

@@ -463,6 +463,14 @@ func (s *Swap) processAndVerifyCheque(cheque *Cheque, p *Peer) (*int256.Uint256,
 		return nil, err
 	}
 
+	bouncedCheque, err := p.hasBouncedCheque()
+	if err != nil {
+		return nil, err
+	}
+	if bouncedCheque {
+		return nil, ErrBouncedCheque
+	}
+
 	lastCheque := p.getLastReceivedCheque()
 
 	// TODO: there should probably be a lock here?