all: on-chain oracle checkpoint syncing (#19543)

* all: implement simple checkpoint syncing

cmd, les, node: remove callback mechanism

cmd, node: remove callback definition

les: simplify the registrar

les: expose checkpoint rpc services in the light client

les, light: don't store untrusted receipt

cmd, contracts, les: discard stale checkpoint

cmd, contracts/registrar: loose restriction of registeration

cmd, contracts: add replay-protection

all: off-chain multi-signature contract

params: deploy checkpoint contract for rinkeby

cmd/registrar: add raw signing mode for registrar

cmd/registrar, contracts/registrar, les: fixed messages

* cmd/registrar, contracts/registrar: fix lints

* accounts/abi/bind, les: address comments

* cmd, contracts, les, light, params: minor checkpoint sync cleanups

* cmd, eth, les, light: move checkpoint config to config file

* cmd, eth, les, params: address comments

* eth, les, params: address comments

* cmd: polish up the checkpoint admin CLI

* cmd, contracts, params: deploy new version contract

* cmd/checkpoint-admin: add another flag for clef mode signing

* cmd, contracts, les: rename and regen checkpoint oracle with abigen

les/api.go

@@ -34,6 +34,8 @@ var (
 	ErrMinCap               = errors.New("capacity too small")
 	ErrTotalCap             = errors.New("total capacity exceeded")
 	ErrUnknownBenchmarkType = errors.New("unknown benchmark type")
+	ErrNoCheckpoint         = errors.New("no local checkpoint provided")
+	ErrNotActivated         = errors.New("checkpoint registrar is not activated")
 
 	dropCapacityDelay = time.Second // delay applied to decreasing capacity changes
 )
@@ -470,3 +472,59 @@ func (api *PrivateLightServerAPI) Benchmark(setups []map[string]interface{}, pas
 	}
 	return result, nil
 }
+
+// PrivateLightAPI provides an API to access the LES light server or light client.
+type PrivateLightAPI struct {
+	backend *lesCommons
+	reg     *checkpointOracle
+}
+
+// NewPrivateLightAPI creates a new LES service API.
+func NewPrivateLightAPI(backend *lesCommons, reg *checkpointOracle) *PrivateLightAPI {
+	return &PrivateLightAPI{
+		backend: backend,
+		reg:     reg,
+	}
+}
+
+// LatestCheckpoint returns the latest local checkpoint package.
+//
+// The checkpoint package consists of 4 strings:
+//   result[0], hex encoded latest section index
+//   result[1], 32 bytes hex encoded latest section head hash
+//   result[2], 32 bytes hex encoded latest section canonical hash trie root hash
+//   result[3], 32 bytes hex encoded latest section bloom trie root hash
+func (api *PrivateLightAPI) LatestCheckpoint() ([4]string, error) {
+	var res [4]string
+	cp := api.backend.latestLocalCheckpoint()
+	if cp.Empty() {
+		return res, ErrNoCheckpoint
+	}
+	res[0] = hexutil.EncodeUint64(cp.SectionIndex)
+	res[1], res[2], res[3] = cp.SectionHead.Hex(), cp.CHTRoot.Hex(), cp.BloomRoot.Hex()
+	return res, nil
+}
+
+// GetLocalCheckpoint returns the specific local checkpoint package.
+//
+// The checkpoint package consists of 3 strings:
+//   result[0], 32 bytes hex encoded latest section head hash
+//   result[1], 32 bytes hex encoded latest section canonical hash trie root hash
+//   result[2], 32 bytes hex encoded latest section bloom trie root hash
+func (api *PrivateLightAPI) GetCheckpoint(index uint64) ([3]string, error) {
+	var res [3]string
+	cp := api.backend.getLocalCheckpoint(index)
+	if cp.Empty() {
+		return res, ErrNoCheckpoint
+	}
+	res[0], res[1], res[2] = cp.SectionHead.Hex(), cp.CHTRoot.Hex(), cp.BloomRoot.Hex()
+	return res, nil
+}
+
+// GetCheckpointContractAddress returns the contract contract address in hex format.
+func (api *PrivateLightAPI) GetCheckpointContractAddress() (string, error) {
+	if api.reg == nil {
+		return "", ErrNotActivated
+	}
+	return api.reg.config.Address.Hex(), nil
+}