builtinSCCs := map[string]struct{}{
"lscc": {},
"qscc": {},
"cscc": {},
"_lifecycle": {},
}
BuiltinSCCs are special system chaincodes, differentiated from other (plugin) system chaincodes. These chaincodes do not need to be initialized in ‘_lifecycle’ and may be invoked without a channel context. It is expected that ‘_lifecycle’ will eventually be the only builtin SCCs. Note, this field should only be used on endorsement side, never in validation as it might change.
All system chaincodes have to implement:
// Chaincode interface must be implemented by all chaincodes. The fabric runs
// the transactions by calling these functions as specified.
type Chaincode interface {
// Init is called during Instantiate transaction after the chaincode container
// has been established for the first time, allowing the chaincode to
// initialize its internal data
Init(stub ChaincodeStubInterface) pb.Response
// Invoke is called to update or query the ledger in a proposal transaction.
// Updated state variables are not committed to the ledger until the
// transaction is committed.
Invoke(stub ChaincodeStubInterface) pb.Response
}
type SelfDescribingSysCC interface {
//Unique name of the system chaincode
Name() string
// Chaincode returns the underlying chaincode
Chaincode() shim.Chaincode
}
_lifecycle is new in fabric 2.0. It is used to manage CC in a new way.
// PeerConfiger implements the configuration handler for the peer. For every
// configuration transaction coming in from the ordering service, the
// committer calls this system chaincode to process the transaction.
type PeerConfiger struct {
policyChecker policy.PolicyChecker
configMgr config.Manager
aclProvider aclmgmt.ACLProvider
deployedCCInfoProvider ledger.DeployedChaincodeInfoProvider
legacyLifecycle plugindispatcher.LifecycleResources
newLifecycle plugindispatcher.CollectionAndLifecycleResources
peer *peer.Peer
bccsp bccsp.BCCSP
}
// Invoke is called for the following:
// # to process joining a chain (called by app as a transaction proposal)
// # to get the current configuration block (called by app)
// # to update the configuration block (called by committer)
// Peer calls this function with 2 arguments:
// # args[0] is the function name, which must be JoinChain, GetConfigBlock or
// UpdateConfigBlock
// # args[1] is a configuration Block if args[0] is JoinChain or
// UpdateConfigBlock; otherwise it is the chain id
// TODO: Improve the scc interface to avoid marshal/unmarshal args
func (e *PeerConfiger) Invoke(stub shim.ChaincodeStubInterface) pb.Response {
args := stub.GetArgs()
if len(args) < 1 {
return shim.Error(fmt.Sprintf("Incorrect number of arguments, %d", len(args)))
}
fname := string(args[0])
if fname != GetChannels && len(args) < 2 {
return shim.Error(fmt.Sprintf("Incorrect number of arguments, %d", len(args)))
}
cnflogger.Debugf("Invoke function: %s", fname)
// Handle ACL:
// 1. get the signed proposal
sp, err := stub.GetSignedProposal()
if err != nil {
return shim.Error(fmt.Sprintf("Failed getting signed proposal from stub: [%s]", err))
}
name, err := protoutil.InvokedChaincodeName(sp.ProposalBytes)
if err != nil {
return shim.Error(fmt.Sprintf("Failed to identify the called chaincode: %s", err))
}
if name != e.Name() {
return shim.Error(fmt.Sprintf("Rejecting invoke of CSCC from another chaincode, original invocation for '%s'", name))
}
return e.InvokeNoShim(args, sp)
}
// LedgerQuerier implements the ledger query functions, including:
// - GetChainInfo returns BlockchainInfo
// - GetBlockByNumber returns a block
// - GetBlockByHash returns a block
// - GetTransactionByID returns a transaction
type LedgerQuerier struct {
aclProvider aclmgmt.ACLProvider
ledgers LedgerGetter
}
// Invoke is called with args[0] contains the query function name, args[1]
// contains the chain ID, which is temporary for now until it is part of stub.
// Each function requires additional parameters as described below:
// # GetChainInfo: Return a BlockchainInfo object marshalled in bytes
// # GetBlockByNumber: Return the block specified by block number in args[2]
// # GetBlockByHash: Return the block specified by block hash in args[2]
// # GetTransactionByID: Return the transaction specified by ID in args[2]
func (e *LedgerQuerier) Invoke(stub shim.ChaincodeStubInterface) pb.Response {
args := stub.GetArgs()
if len(args) < 2 {
return shim.Error(fmt.Sprintf("Incorrect number of arguments, %d", len(args)))
}
fname := string(args[0])
cid := string(args[1])
sp, err := stub.GetSignedProposal()
if err != nil {
return shim.Error(fmt.Sprintf("Failed getting signed proposal from stub, %s: %s", cid, err))
}
name, err := protoutil.InvokedChaincodeName(sp.ProposalBytes)
if err != nil {
return shim.Error(fmt.Sprintf("Failed to identify the called chaincode: %s", err))
}
if name != e.Name() {
return shim.Error(fmt.Sprintf("Rejecting invoke of QSCC from another chaincode because of potential for deadlocks, original invocation for '%s'", name))
}
if fname != GetChainInfo && len(args) < 3 {
return shim.Error(fmt.Sprintf("missing 3rd argument for %s", fname))
}
targetLedger := e.ledgers.GetLedger(cid)
if targetLedger == nil {
return shim.Error(fmt.Sprintf("Invalid chain ID, %s", cid))
}
qscclogger.Debugf("Invoke function: %s on chain: %s", fname, cid)
// Handle ACL:
res := getACLResource(fname)
if err = e.aclProvider.CheckACL(res, cid, sp); err != nil {
return shim.Error(fmt.Sprintf("access denied for [%s][%s]: [%s]", fname, cid, err))
}
switch fname {
case GetTransactionByID:
return getTransactionByID(targetLedger, args[2])
case GetBlockByNumber:
return getBlockByNumber(targetLedger, args[2])
case GetBlockByHash:
return getBlockByHash(targetLedger, args[2])
case GetChainInfo:
return getChainInfo(targetLedger)
case GetBlockByTxID:
return getBlockByTxID(targetLedger, args[2])
}
return shim.Error(fmt.Sprintf("Requested function %s not found.", fname))
}
Legacy lifecycle manager, used by v1.4 and earlier.
// SCC implements chaincode lifecycle and policies around it
type SCC struct {
// aclProvider is responsible for access control evaluation
ACLProvider aclmgmt.ACLProvider
BuiltinSCCs scc.BuiltinSCCs
// SCCProvider is the interface which is passed into system chaincodes
// to access other parts of the system. It is initialized to be the peer instance
SCCProvider sysccprovider.SystemChaincodeProvider
// PolicyChecker is the interface used to perform
// access control
PolicyChecker policy.PolicyChecker
// Support provides the implementation of several
// static functions
Support FilesystemSupport
GetMSPIDs MSPIDsGetter
BuildRegistry *container.BuildRegistry
ChaincodeBuilder ChaincodeBuilder
EbMetadataProvider *externalbuilder.MetadataProvider
// BCCSP instance
BCCSP bccsp.BCCSP
PackageCache PackageCache
}
// Invoke implements lifecycle functions "deploy", "start", "stop", "upgrade".
// Deploy's arguments - {[]byte("deploy"), []byte(), }
//
// Invoke also implements some query-like functions
// Get chaincode arguments - {[]byte("getid"), []byte(), []byte()}
func (lscc *SCC) Invoke(stub shim.ChaincodeStubInterface) pb.Response {
args := stub.GetArgs()
...
It uses Dispatcher to invoke the underlying commands. As below call stack:
github.com/hyperledger/fabric/core/chaincode/lifecycle.(*Invocation).QueryInstalledChaincodes at scc.go:321
runtime.call64 at asm_amd64.s:540
reflect.Value.call at value.go:460
reflect.Value.Call at value.go:321
github.com/hyperledger/fabric/core/dispatcher.(*Dispatcher).Dispatch at dispatcher.go:66
github.com/hyperledger/fabric/core/chaincode/lifecycle.(*SCC).Invoke at scc.go:207
// SCCFunctions provides a backing implementation with concrete arguments
// for each of the SCC functions
type SCCFunctions interface {
// InstallChaincode persists a chaincode definition to disk
InstallChaincode([]byte) (*chaincode.InstalledChaincode, error)
// QueryInstalledChaincode returns metadata for the chaincode with the supplied package ID.
QueryInstalledChaincode(packageID string) (*chaincode.InstalledChaincode, error)
// GetInstalledChaincodePackage returns the chaincode package
// installed on the peer as bytes.
GetInstalledChaincodePackage(packageID string) ([]byte, error)
// QueryInstalledChaincodes returns the currently installed chaincodes
QueryInstalledChaincodes() []*chaincode.InstalledChaincode
// ApproveChaincodeDefinitionForOrg records a chaincode definition into this org's implicit collection.
ApproveChaincodeDefinitionForOrg(chname, ccname string, cd *ChaincodeDefinition, packageID string, publicState ReadableState, orgState ReadWritableState) error
// CheckCommitReadiness returns a map containing the orgs
// whose orgStates were supplied and whether or not they have approved
// the specified definition.
CheckCommitReadiness(chname, ccname string, cd *ChaincodeDefinition, publicState ReadWritableState, orgStates []OpaqueState) (map[string]bool, error)
// CommitChaincodeDefinition records a new chaincode definition into the
// public state and returns a map containing the orgs whose orgStates
// were supplied and whether or not they have approved the definition.
CommitChaincodeDefinition(chname, ccname string, cd *ChaincodeDefinition, publicState ReadWritableState, orgStates []OpaqueState) (map[string]bool, error)
// QueryChaincodeDefinition returns a chaincode definition from the public
// state.
QueryChaincodeDefinition(name string, publicState ReadableState) (*ChaincodeDefinition, error)
// QueryOrgApprovals returns a map containing the orgs whose orgStates were
// supplied and whether or not they have approved a chaincode definition with
// the specified parameters.
QueryOrgApprovals(name string, cd *ChaincodeDefinition, orgStates []OpaqueState) (map[string]bool, error)
// QueryNamespaceDefinitions returns all defined namespaces
QueryNamespaceDefinitions(publicState RangeableState) (map[string]string, error)
}
// SCC implements the required methods to satisfy the chaincode interface.
// It routes the invocation calls to the backing implementations.
type SCC struct {
OrgMSPID string
ACLProvider aclmgmt.ACLProvider
ChannelConfigSource ChannelConfigSource
DeployedCCInfoProvider ledger.DeployedChaincodeInfoProvider
QueryExecutorProvider QueryExecutorProvider
// Functions provides the backing implementation of lifecycle.
Functions SCCFunctions
// Dispatcher handles the rote protobuf boilerplate for unmarshaling/marshaling
// the inputs and outputs of the SCC functions.
Dispatcher *dispatcher.Dispatcher
}
// Invoke takes chaincode invocation arguments and routes them to the correct
// underlying lifecycle operation. All functions take a single argument of
// type marshaled lb.Args and return a marshaled lb.Result
func (scc *SCC) Invoke(stub shim.ChaincodeStubInterface) pb.Response {
args := stub.GetArgs()
if len(args) == 0 {
return shim.Error("lifecycle scc must be invoked with arguments")
}
if len(args) != 2 {
return shim.Error(fmt.Sprintf("lifecycle scc operations require exactly two arguments but received %d", len(args)))
}
var ac channelconfig.Application
var channelID string
if channelID = stub.GetChannelID(); channelID != "" {
channelConfig := scc.ChannelConfigSource.GetStableChannelConfig(channelID)
if channelConfig == nil {
return shim.Error(fmt.Sprintf("could not get channelconfig for channel '%s'", channelID))
}
var ok bool
ac, ok = channelConfig.ApplicationConfig()
if !ok {
return shim.Error(fmt.Sprintf("could not get application config for channel '%s'", channelID))
}
if !ac.Capabilities().LifecycleV20() {
return shim.Error(fmt.Sprintf("cannot use new lifecycle for channel '%s' as it does not have the required capabilities enabled", channelID))
}
}
// Handle ACL:
sp, err := stub.GetSignedProposal()
if err != nil {
return shim.Error(fmt.Sprintf("Failed getting signed proposal from stub: [%s]", err))
}
err = scc.ACLProvider.CheckACL(fmt.Sprintf("%s/%s", LifecycleNamespace, args[0]), stub.GetChannelID(), sp)
if err != nil {
return shim.Error(fmt.Sprintf("Failed to authorize invocation due to failed ACL check: %s", err))
}
outputBytes, err := scc.Dispatcher.Dispatch(
args[1],
string(args[0]),
&Invocation{
ChannelID: channelID,
ApplicationConfig: ac,
SCC: scc,
Stub: stub,
},
)
if err != nil {
switch err.(type) {
case ErrNamespaceNotDefined, persistence.CodePackageNotFoundErr:
return pb.Response{
Status: 404,
Message: err.Error(),
}
default:
return shim.Error(fmt.Sprintf("failed to invoke backing implementation of '%s': %s", string(args[0]), err.Error()))
}
}
return shim.Success(outputBytes)
}
// SCC dispatcher
// Dispatcher is used to handle the boilerplate proto tasks of unmarshaling inputs and remarshaling outputs
// so that the receiver may focus on the implementation details rather than the proto hassles.
type Dispatcher struct {
// Protobuf should pass through to Google Protobuf in production paths
Protobuf Protobuf
}
// Dispatch deserializes the input bytes to the correct type for the method in the receiver, then
// if successful, marshals the output message to bytes and returns it. On error, it simply returns
// the error. The method on the receiver must take a single parameter which is a concrete proto
// message type and it should return a proto message and error.
func (d *Dispatcher) Dispatch(inputBytes []byte, methodName string, receiver interface{}) ([]byte, error) {
method := reflect.ValueOf(receiver).MethodByName(methodName)
if method == (reflect.Value{}) {
return nil, errors.Errorf("receiver %T.%s does not exist", receiver, methodName)
}
if method.Type().NumIn() != 1 {
return nil, errors.Errorf("receiver %T.%s has %d parameters but expected 1", receiver, methodName, method.Type().NumIn())
}
inputType := method.Type().In(0)
if inputType.Kind() != reflect.Ptr {
return nil, errors.Errorf("receiver %T.%s does not accept a pointer as its argument", receiver, methodName)
}
if method.Type().NumOut() != 2 {
return nil, errors.Errorf("receiver %T.%s returns %d values but expected 2", receiver, methodName, method.Type().NumOut())
}
if !method.Type().Out(0).Implements(reflect.TypeOf((*proto.Message)(nil)).Elem()) {
return nil, errors.Errorf("receiver %T.%s does not return a an implementor of proto.Message as its first return value", receiver, methodName)
}
if !method.Type().Out(1).Implements(reflect.TypeOf((*error)(nil)).Elem()) {
return nil, errors.Errorf("receiver %T.%s does not return an error as its second return value", receiver, methodName)
}
inputValue := reflect.New(inputType.Elem())
inputMsg, ok := inputValue.Interface().(proto.Message)
if !ok {
return nil, errors.Errorf("receiver %T.%s does not accept a proto.Message as its argument, it is '%T'", receiver, methodName, inputValue.Interface())
}
err := d.Protobuf.Unmarshal(inputBytes, inputMsg)
if err != nil {
return nil, errors.WithMessagef(err, "could not decode input arg for %T.%s", receiver, methodName)
}
outputVals := method.Call([]reflect.Value{inputValue})
if !outputVals[1].IsNil() {
return nil, outputVals[1].Interface().(error)
}
if outputVals[0].IsNil() {
return nil, errors.Errorf("receiver %T.%s returned (nil, nil) which is not allowed", receiver, methodName)
}
outputMsg := outputVals[0].Interface().(proto.Message)
resultBytes, err := d.Protobuf.Marshal(outputMsg)
if err != nil {
return nil, errors.WithMessagef(err, "failed to marshal result for %T.%s", receiver, methodName)
}
return resultBytes, nil
}
Similar with user cc, sys cc are deployed as two parts:
The difference is sys cc are deployed via inProcStream, using ‘go chan’ to simulate the gRPC. Fundementally, inProcStream has two ‘go chan’ for sending and receiving.
// DeploySysCC is the hook for system chaincodes where system chaincodes are registered with the fabric.
// This call directly registers the chaincode with the chaincode handler and bypasses the other usercc constructs.
func DeploySysCC(sysCC SelfDescribingSysCC, chaincodeStreamHandler ChaincodeStreamHandler) {
sysccLogger.Infof("deploying system chaincode '%s'", sysCC.Name())
ccid := ChaincodeID(sysCC.Name())
done := chaincodeStreamHandler.LaunchInProc(ccid)
peerRcvCCSend := make(chan *pb.ChaincodeMessage)
ccRcvPeerSend := make(chan *pb.ChaincodeMessage)
go func() {
stream := newInProcStream(peerRcvCCSend, ccRcvPeerSend)
defer stream.CloseSend()
sysccLogger.Debugf("starting chaincode-support stream for %s", ccid)
err := chaincodeStreamHandler.HandleChaincodeStream(stream)
sysccLogger.Criticalf("shim stream ended with err: %v", err)
}()
go func(sysCC SelfDescribingSysCC) {
stream := newInProcStream(ccRcvPeerSend, peerRcvCCSend)
defer stream.CloseSend()
sysccLogger.Debugf("chaincode started for %s", ccid)
err := shim.StartInProc(ccid, stream, sysCC.Chaincode())
sysccLogger.Criticalf("system chaincode ended with err: %v", err)
}(sysCC)
<-done
}