contracts/ens: Add ENS contract binding

1 files changed, 178 insertions, 0 deletions

diff --git a/contracts/ens/ens.go b/contracts/ens/ens.go
new file mode 100644
index 000000000..59147e183
--- /dev/null
+++ b/contracts/ens/ens.go
@@ -0,0 +1,178 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package ens
+
+//go:generate abigen --sol contract/ens.sol --pkg contract --out contract/ens.go
+
+import (
+	"math/big"
+	"strings"
+
+	"github.com/ethereum/go-ethereum/accounts/abi/bind"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/contracts/ens/contract"
+)
+
+// swarm domain name registry and resolver
+type ENS struct {
+	*contract.ENSSession
+	contractBackend bind.ContractBackend
+}
+
+// NewENS creates a struct exposing convenient high-level operations for interacting with
+// the Ethereum Name Service.
+func NewENS(transactOpts *bind.TransactOpts, contractAddr common.Address, contractBackend bind.ContractBackend) (*ENS, error) {
+	ens, err := contract.NewENS(contractAddr, contractBackend)
+	if err != nil {
+		return nil, err
+	}
+
+	return &ENS{
+		&contract.ENSSession{
+			Contract:     ens,
+			TransactOpts: *transactOpts,
+		},
+		contractBackend,
+	}, nil
+}
+
+// DeployENS deploys an instance of the ENS nameservice, with a 'first in first served' root registrar.
+func DeployENS(transactOpts *bind.TransactOpts, contractBackend bind.ContractBackend) (*ENS, error) {
+	// Deploy the ENS registry
+	ensAddr, _, _, err := contract.DeployENS(transactOpts, contractBackend, transactOpts.From)
+	if err != nil {
+		return nil, err
+	}
+
+	ens, err := NewENS(transactOpts, ensAddr, contractBackend)
+	if err != nil {
+		return nil, err
+	}
+
+	// Deploy the registrar
+	regAddr, _, _, err := contract.DeployFIFSRegistrar(transactOpts, contractBackend, ensAddr, [32]byte{})
+	if err != nil {
+		return nil, err
+	}
+
+	// Set the registrar as owner of the ENS root
+	_, err = ens.SetOwner([32]byte{}, regAddr)
+	if err != nil {
+		return nil, err
+	}
+
+	return ens, nil
+}
+
+func ensParentNode(name string) (common.Hash, common.Hash) {
+	parts := strings.SplitN(name, ".", 2)
+	label := crypto.Keccak256Hash([]byte(parts[0]))
+	if len(parts) == 1 {
+		return [32]byte{}, label
+	} else {
+		parentNode, parentLabel := ensParentNode(parts[1])
+		return crypto.Keccak256Hash(parentNode[:], parentLabel[:]), label
+	}
+}
+
+func ensNode(name string) common.Hash {
+	parentNode, parentLabel := ensParentNode(name)
+	return crypto.Keccak256Hash(parentNode[:], parentLabel[:])
+}
+
+func (self *ENS) getResolver(node [32]byte) (*contract.PublicResolverSession, error) {
+	resolverAddr, err := self.Resolver(node)
+	if err != nil {
+		return nil, err
+	}
+
+	resolver, err := contract.NewPublicResolver(resolverAddr, self.contractBackend)
+	if err != nil {
+		return nil, err
+	}
+
+	return &contract.PublicResolverSession{
+		Contract:     resolver,
+		TransactOpts: self.TransactOpts,
+	}, nil
+}
+
+func (self *ENS) getRegistrar(node [32]byte) (*contract.FIFSRegistrarSession, error) {
+	registrarAddr, err := self.Owner(node)
+	if err != nil {
+		return nil, err
+	}
+
+	registrar, err := contract.NewFIFSRegistrar(registrarAddr, self.contractBackend)
+	if err != nil {
+		return nil, err
+	}
+
+	return &contract.FIFSRegistrarSession{
+		Contract:     registrar,
+		TransactOpts: self.TransactOpts,
+	}, nil
+}
+
+// Resolve is a non-transactional call that returns the content hash associated with a name.
+func (self *ENS) Resolve(name string) (common.Hash, error) {
+	node := ensNode(name)
+
+	resolver, err := self.getResolver(node)
+	if err != nil {
+		return common.Hash{}, err
+	}
+
+	ret, err := resolver.Content(node)
+	if err != nil {
+		return common.Hash{}, err
+	}
+
+	return common.BytesToHash(ret[:]), nil
+}
+
+// Register registers a new domain name for the caller, making them the owner of the new name.
+// Only works if the registrar for the parent domain implements the FIFS registrar protocol.
+func (self *ENS) Register(name string) (*types.Transaction, error) {
+	parentNode, label := ensParentNode(name)
+
+	registrar, err := self.getRegistrar(parentNode)
+	if err != nil {
+		return nil, err
+	}
+
+	opts := self.TransactOpts
+	opts.GasLimit = big.NewInt(200000)
+	return registrar.Contract.Register(&opts, label, self.TransactOpts.From)
+}
+
+// SetContentHash sets the content hash associated with a name. Only works if the caller
+// owns the name, and the associated resolver implements a `setContent` function.
+func (self *ENS) SetContentHash(name string, hash common.Hash) (*types.Transaction, error) {
+	node := ensNode(name)
+
+	resolver, err := self.getResolver(node)
+	if err != nil {
+		return nil, err
+	}
+
+	opts := self.TransactOpts
+	opts.GasLimit = big.NewInt(200000)
+	return resolver.Contract.SetContent(&opts, node, hash)
+}