build(deps): bump google.golang.org/grpc from 1.50.1 to 1.56.3

Bumps [google.golang.org/grpc](https://github.com/grpc/grpc-go) from 1.50.1 to 1.56.3.
- [Release notes](https://github.com/grpc/grpc-go/releases)
- [Commits](https://github.com/grpc/grpc-go/compare/v1.50.1...v1.56.3)

---
updated-dependencies:
- dependency-name: google.golang.org/grpc
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>

vendor/google.golang.org/grpc/internal/credentials/credentials.go

@@ -0,0 +1,49 @@
+/*
+ * Copyright 2021 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package credentials
+
+import (
+	"context"
+)
+
+// requestInfoKey is a struct to be used as the key to store RequestInfo in a
+// context.
+type requestInfoKey struct{}
+
+// NewRequestInfoContext creates a context with ri.
+func NewRequestInfoContext(ctx context.Context, ri interface{}) context.Context {
+	return context.WithValue(ctx, requestInfoKey{}, ri)
+}
+
+// RequestInfoFromContext extracts the RequestInfo from ctx.
+func RequestInfoFromContext(ctx context.Context) interface{} {
+	return ctx.Value(requestInfoKey{})
+}
+
+// clientHandshakeInfoKey is a struct used as the key to store
+// ClientHandshakeInfo in a context.
+type clientHandshakeInfoKey struct{}
+
+// ClientHandshakeInfoFromContext extracts the ClientHandshakeInfo from ctx.
+func ClientHandshakeInfoFromContext(ctx context.Context) interface{} {
+	return ctx.Value(clientHandshakeInfoKey{})
+}
+
+// NewClientHandshakeInfoContext creates a context with chi.
+func NewClientHandshakeInfoContext(ctx context.Context, chi interface{}) context.Context {
+	return context.WithValue(ctx, clientHandshakeInfoKey{}, chi)
+}

vendor/google.golang.org/grpc/internal/credentials/spiffe.go

@@ -0,0 +1,75 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package credentials defines APIs for parsing SPIFFE ID.
+//
+// All APIs in this package are experimental.
+package credentials
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"net/url"
+
+	"google.golang.org/grpc/grpclog"
+)
+
+var logger = grpclog.Component("credentials")
+
+// SPIFFEIDFromState parses the SPIFFE ID from State. If the SPIFFE ID format
+// is invalid, return nil with warning.
+func SPIFFEIDFromState(state tls.ConnectionState) *url.URL {
+	if len(state.PeerCertificates) == 0 || len(state.PeerCertificates[0].URIs) == 0 {
+		return nil
+	}
+	return SPIFFEIDFromCert(state.PeerCertificates[0])
+}
+
+// SPIFFEIDFromCert parses the SPIFFE ID from x509.Certificate. If the SPIFFE
+// ID format is invalid, return nil with warning.
+func SPIFFEIDFromCert(cert *x509.Certificate) *url.URL {
+	if cert == nil || cert.URIs == nil {
+		return nil
+	}
+	var spiffeID *url.URL
+	for _, uri := range cert.URIs {
+		if uri == nil || uri.Scheme != "spiffe" || uri.Opaque != "" || (uri.User != nil && uri.User.Username() != "") {
+			continue
+		}
+		// From this point, we assume the uri is intended for a SPIFFE ID.
+		if len(uri.String()) > 2048 {
+			logger.Warning("invalid SPIFFE ID: total ID length larger than 2048 bytes")
+			return nil
+		}
+		if len(uri.Host) == 0 || len(uri.Path) == 0 {
+			logger.Warning("invalid SPIFFE ID: domain or workload ID is empty")
+			return nil
+		}
+		if len(uri.Host) > 255 {
+			logger.Warning("invalid SPIFFE ID: domain length larger than 255 characters")
+			return nil
+		}
+		// A valid SPIFFE certificate can only have exactly one URI SAN field.
+		if len(cert.URIs) > 1 {
+			logger.Warning("invalid SPIFFE ID: multiple URI SANs")
+			return nil
+		}
+		spiffeID = uri
+	}
+	return spiffeID
+}

vendor/google.golang.org/grpc/internal/credentials/syscallconn.go

@@ -0,0 +1,58 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package credentials
+
+import (
+	"net"
+	"syscall"
+)
+
+type sysConn = syscall.Conn
+
+// syscallConn keeps reference of rawConn to support syscall.Conn for channelz.
+// SyscallConn() (the method in interface syscall.Conn) is explicitly
+// implemented on this type,
+//
+// Interface syscall.Conn is implemented by most net.Conn implementations (e.g.
+// TCPConn, UnixConn), but is not part of net.Conn interface. So wrapper conns
+// that embed net.Conn don't implement syscall.Conn. (Side note: tls.Conn
+// doesn't embed net.Conn, so even if syscall.Conn is part of net.Conn, it won't
+// help here).
+type syscallConn struct {
+	net.Conn
+	// sysConn is a type alias of syscall.Conn. It's necessary because the name
+	// `Conn` collides with `net.Conn`.
+	sysConn
+}
+
+// WrapSyscallConn tries to wrap rawConn and newConn into a net.Conn that
+// implements syscall.Conn. rawConn will be used to support syscall, and newConn
+// will be used for read/write.
+//
+// This function returns newConn if rawConn doesn't implement syscall.Conn.
+func WrapSyscallConn(rawConn, newConn net.Conn) net.Conn {
+	sysConn, ok := rawConn.(syscall.Conn)
+	if !ok {
+		return newConn
+	}
+	return &syscallConn{
+		Conn:    newConn,
+		sysConn: sysConn,
+	}
+}

vendor/google.golang.org/grpc/internal/credentials/util.go

@@ -0,0 +1,52 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package credentials
+
+import (
+	"crypto/tls"
+)
+
+const alpnProtoStrH2 = "h2"
+
+// AppendH2ToNextProtos appends h2 to next protos.
+func AppendH2ToNextProtos(ps []string) []string {
+	for _, p := range ps {
+		if p == alpnProtoStrH2 {
+			return ps
+		}
+	}
+	ret := make([]string, 0, len(ps)+1)
+	ret = append(ret, ps...)
+	return append(ret, alpnProtoStrH2)
+}
+
+// CloneTLSConfig returns a shallow clone of the exported
+// fields of cfg, ignoring the unexported sync.Once, which
+// contains a mutex and must not be copied.
+//
+// If cfg is nil, a new zero tls.Config is returned.
+//
+// TODO: inline this function if possible.
+func CloneTLSConfig(cfg *tls.Config) *tls.Config {
+	if cfg == nil {
+		return &tls.Config{}
+	}
+
+	return cfg.Clone()
+}

vendor/google.golang.org/grpc/internal/grpclog/grpclog.go

@@ -0,0 +1,126 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package grpclog (internal) defines depth logging for grpc.
+package grpclog
+
+import (
+	"os"
+)
+
+// Logger is the logger used for the non-depth log functions.
+var Logger LoggerV2
+
+// DepthLogger is the logger used for the depth log functions.
+var DepthLogger DepthLoggerV2
+
+// InfoDepth logs to the INFO log at the specified depth.
+func InfoDepth(depth int, args ...interface{}) {
+	if DepthLogger != nil {
+		DepthLogger.InfoDepth(depth, args...)
+	} else {
+		Logger.Infoln(args...)
+	}
+}
+
+// WarningDepth logs to the WARNING log at the specified depth.
+func WarningDepth(depth int, args ...interface{}) {
+	if DepthLogger != nil {
+		DepthLogger.WarningDepth(depth, args...)
+	} else {
+		Logger.Warningln(args...)
+	}
+}
+
+// ErrorDepth logs to the ERROR log at the specified depth.
+func ErrorDepth(depth int, args ...interface{}) {
+	if DepthLogger != nil {
+		DepthLogger.ErrorDepth(depth, args...)
+	} else {
+		Logger.Errorln(args...)
+	}
+}
+
+// FatalDepth logs to the FATAL log at the specified depth.
+func FatalDepth(depth int, args ...interface{}) {
+	if DepthLogger != nil {
+		DepthLogger.FatalDepth(depth, args...)
+	} else {
+		Logger.Fatalln(args...)
+	}
+	os.Exit(1)
+}
+
+// LoggerV2 does underlying logging work for grpclog.
+// This is a copy of the LoggerV2 defined in the external grpclog package. It
+// is defined here to avoid a circular dependency.
+type LoggerV2 interface {
+	// Info logs to INFO log. Arguments are handled in the manner of fmt.Print.
+	Info(args ...interface{})
+	// Infoln logs to INFO log. Arguments are handled in the manner of fmt.Println.
+	Infoln(args ...interface{})
+	// Infof logs to INFO log. Arguments are handled in the manner of fmt.Printf.
+	Infof(format string, args ...interface{})
+	// Warning logs to WARNING log. Arguments are handled in the manner of fmt.Print.
+	Warning(args ...interface{})
+	// Warningln logs to WARNING log. Arguments are handled in the manner of fmt.Println.
+	Warningln(args ...interface{})
+	// Warningf logs to WARNING log. Arguments are handled in the manner of fmt.Printf.
+	Warningf(format string, args ...interface{})
+	// Error logs to ERROR log. Arguments are handled in the manner of fmt.Print.
+	Error(args ...interface{})
+	// Errorln logs to ERROR log. Arguments are handled in the manner of fmt.Println.
+	Errorln(args ...interface{})
+	// Errorf logs to ERROR log. Arguments are handled in the manner of fmt.Printf.
+	Errorf(format string, args ...interface{})
+	// Fatal logs to ERROR log. Arguments are handled in the manner of fmt.Print.
+	// gRPC ensures that all Fatal logs will exit with os.Exit(1).
+	// Implementations may also call os.Exit() with a non-zero exit code.
+	Fatal(args ...interface{})
+	// Fatalln logs to ERROR log. Arguments are handled in the manner of fmt.Println.
+	// gRPC ensures that all Fatal logs will exit with os.Exit(1).
+	// Implementations may also call os.Exit() with a non-zero exit code.
+	Fatalln(args ...interface{})
+	// Fatalf logs to ERROR log. Arguments are handled in the manner of fmt.Printf.
+	// gRPC ensures that all Fatal logs will exit with os.Exit(1).
+	// Implementations may also call os.Exit() with a non-zero exit code.
+	Fatalf(format string, args ...interface{})
+	// V reports whether verbosity level l is at least the requested verbose level.
+	V(l int) bool
+}
+
+// DepthLoggerV2 logs at a specified call frame. If a LoggerV2 also implements
+// DepthLoggerV2, the below functions will be called with the appropriate stack
+// depth set for trivial functions the logger may ignore.
+// This is a copy of the DepthLoggerV2 defined in the external grpclog package.
+// It is defined here to avoid a circular dependency.
+//
+// # Experimental
+//
+// Notice: This type is EXPERIMENTAL and may be changed or removed in a
+// later release.
+type DepthLoggerV2 interface {
+	// InfoDepth logs to INFO log at the specified depth. Arguments are handled in the manner of fmt.Println.
+	InfoDepth(depth int, args ...interface{})
+	// WarningDepth logs to WARNING log at the specified depth. Arguments are handled in the manner of fmt.Println.
+	WarningDepth(depth int, args ...interface{})
+	// ErrorDepth logs to ERROR log at the specified depth. Arguments are handled in the manner of fmt.Println.
+	ErrorDepth(depth int, args ...interface{})
+	// FatalDepth logs to FATAL log at the specified depth. Arguments are handled in the manner of fmt.Println.
+	FatalDepth(depth int, args ...interface{})
+}

vendor/google.golang.org/grpc/internal/grpclog/prefixLogger.go

@@ -0,0 +1,93 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package grpclog
+
+import (
+	"fmt"
+)
+
+// PrefixLogger does logging with a prefix.
+//
+// Logging method on a nil logs without any prefix.
+type PrefixLogger struct {
+	logger DepthLoggerV2
+	prefix string
+}
+
+// Infof does info logging.
+func (pl *PrefixLogger) Infof(format string, args ...interface{}) {
+	if pl != nil {
+		// Handle nil, so the tests can pass in a nil logger.
+		format = pl.prefix + format
+		pl.logger.InfoDepth(1, fmt.Sprintf(format, args...))
+		return
+	}
+	InfoDepth(1, fmt.Sprintf(format, args...))
+}
+
+// Warningf does warning logging.
+func (pl *PrefixLogger) Warningf(format string, args ...interface{}) {
+	if pl != nil {
+		format = pl.prefix + format
+		pl.logger.WarningDepth(1, fmt.Sprintf(format, args...))
+		return
+	}
+	WarningDepth(1, fmt.Sprintf(format, args...))
+}
+
+// Errorf does error logging.
+func (pl *PrefixLogger) Errorf(format string, args ...interface{}) {
+	if pl != nil {
+		format = pl.prefix + format
+		pl.logger.ErrorDepth(1, fmt.Sprintf(format, args...))
+		return
+	}
+	ErrorDepth(1, fmt.Sprintf(format, args...))
+}
+
+// Debugf does info logging at verbose level 2.
+func (pl *PrefixLogger) Debugf(format string, args ...interface{}) {
+	// TODO(6044): Refactor interfaces LoggerV2 and DepthLogger, and maybe
+	// rewrite PrefixLogger a little to ensure that we don't use the global
+	// `Logger` here, and instead use the `logger` field.
+	if !Logger.V(2) {
+		return
+	}
+	if pl != nil {
+		// Handle nil, so the tests can pass in a nil logger.
+		format = pl.prefix + format
+		pl.logger.InfoDepth(1, fmt.Sprintf(format, args...))
+		return
+	}
+	InfoDepth(1, fmt.Sprintf(format, args...))
+
+}
+
+// V reports whether verbosity level l is at least the requested verbose level.
+func (pl *PrefixLogger) V(l int) bool {
+	// TODO(6044): Refactor interfaces LoggerV2 and DepthLogger, and maybe
+	// rewrite PrefixLogger a little to ensure that we don't use the global
+	// `Logger` here, and instead use the `logger` field.
+	return Logger.V(l)
+}
+
+// NewPrefixLogger creates a prefix logger with the given prefix.
+func NewPrefixLogger(logger DepthLoggerV2, prefix string) *PrefixLogger {
+	return &PrefixLogger{logger: logger, prefix: prefix}
+}

vendor/google.golang.org/grpc/internal/internal.go

@@ -0,0 +1,194 @@
+/*
+ * Copyright 2016 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package internal contains gRPC-internal code, to avoid polluting
+// the godoc of the top-level grpc package.  It must not import any grpc
+// symbols to avoid circular dependencies.
+package internal
+
+import (
+	"context"
+	"time"
+
+	"google.golang.org/grpc/connectivity"
+	"google.golang.org/grpc/serviceconfig"
+)
+
+var (
+	// WithHealthCheckFunc is set by dialoptions.go
+	WithHealthCheckFunc interface{} // func (HealthChecker) DialOption
+	// HealthCheckFunc is used to provide client-side LB channel health checking
+	HealthCheckFunc HealthChecker
+	// BalancerUnregister is exported by package balancer to unregister a balancer.
+	BalancerUnregister func(name string)
+	// KeepaliveMinPingTime is the minimum ping interval.  This must be 10s by
+	// default, but tests may wish to set it lower for convenience.
+	KeepaliveMinPingTime = 10 * time.Second
+	// ParseServiceConfig parses a JSON representation of the service config.
+	ParseServiceConfig interface{} // func(string) *serviceconfig.ParseResult
+	// EqualServiceConfigForTesting is for testing service config generation and
+	// parsing. Both a and b should be returned by ParseServiceConfig.
+	// This function compares the config without rawJSON stripped, in case the
+	// there's difference in white space.
+	EqualServiceConfigForTesting func(a, b serviceconfig.Config) bool
+	// GetCertificateProviderBuilder returns the registered builder for the
+	// given name. This is set by package certprovider for use from xDS
+	// bootstrap code while parsing certificate provider configs in the
+	// bootstrap file.
+	GetCertificateProviderBuilder interface{} // func(string) certprovider.Builder
+	// GetXDSHandshakeInfoForTesting returns a pointer to the xds.HandshakeInfo
+	// stored in the passed in attributes. This is set by
+	// credentials/xds/xds.go.
+	GetXDSHandshakeInfoForTesting interface{} // func (*attributes.Attributes) *xds.HandshakeInfo
+	// GetServerCredentials returns the transport credentials configured on a
+	// gRPC server. An xDS-enabled server needs to know what type of credentials
+	// is configured on the underlying gRPC server. This is set by server.go.
+	GetServerCredentials interface{} // func (*grpc.Server) credentials.TransportCredentials
+	// CanonicalString returns the canonical string of the code defined here:
+	// https://github.com/grpc/grpc/blob/master/doc/statuscodes.md.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	CanonicalString interface{} // func (codes.Code) string
+	// DrainServerTransports initiates a graceful close of existing connections
+	// on a gRPC server accepted on the provided listener address. An
+	// xDS-enabled server invokes this method on a grpc.Server when a particular
+	// listener moves to "not-serving" mode.
+	DrainServerTransports interface{} // func(*grpc.Server, string)
+	// AddGlobalServerOptions adds an array of ServerOption that will be
+	// effective globally for newly created servers. The priority will be: 1.
+	// user-provided; 2. this method; 3. default values.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	AddGlobalServerOptions interface{} // func(opt ...ServerOption)
+	// ClearGlobalServerOptions clears the array of extra ServerOption. This
+	// method is useful in testing and benchmarking.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	ClearGlobalServerOptions func()
+	// AddGlobalDialOptions adds an array of DialOption that will be effective
+	// globally for newly created client channels. The priority will be: 1.
+	// user-provided; 2. this method; 3. default values.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	AddGlobalDialOptions interface{} // func(opt ...DialOption)
+	// DisableGlobalDialOptions returns a DialOption that prevents the
+	// ClientConn from applying the global DialOptions (set via
+	// AddGlobalDialOptions).
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	DisableGlobalDialOptions interface{} // func() grpc.DialOption
+	// ClearGlobalDialOptions clears the array of extra DialOption. This
+	// method is useful in testing and benchmarking.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	ClearGlobalDialOptions func()
+	// JoinDialOptions combines the dial options passed as arguments into a
+	// single dial option.
+	JoinDialOptions interface{} // func(...grpc.DialOption) grpc.DialOption
+	// JoinServerOptions combines the server options passed as arguments into a
+	// single server option.
+	JoinServerOptions interface{} // func(...grpc.ServerOption) grpc.ServerOption
+
+	// WithBinaryLogger returns a DialOption that specifies the binary logger
+	// for a ClientConn.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	WithBinaryLogger interface{} // func(binarylog.Logger) grpc.DialOption
+	// BinaryLogger returns a ServerOption that can set the binary logger for a
+	// server.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	BinaryLogger interface{} // func(binarylog.Logger) grpc.ServerOption
+
+	// NewXDSResolverWithConfigForTesting creates a new xds resolver builder using
+	// the provided xds bootstrap config instead of the global configuration from
+	// the supported environment variables.  The resolver.Builder is meant to be
+	// used in conjunction with the grpc.WithResolvers DialOption.
+	//
+	// Testing Only
+	//
+	// This function should ONLY be used for testing and may not work with some
+	// other features, including the CSDS service.
+	NewXDSResolverWithConfigForTesting interface{} // func([]byte) (resolver.Builder, error)
+
+	// RegisterRLSClusterSpecifierPluginForTesting registers the RLS Cluster
+	// Specifier Plugin for testing purposes, regardless of the XDSRLS environment
+	// variable.
+	//
+	// TODO: Remove this function once the RLS env var is removed.
+	RegisterRLSClusterSpecifierPluginForTesting func()
+
+	// UnregisterRLSClusterSpecifierPluginForTesting unregisters the RLS Cluster
+	// Specifier Plugin for testing purposes. This is needed because there is no way
+	// to unregister the RLS Cluster Specifier Plugin after registering it solely
+	// for testing purposes using RegisterRLSClusterSpecifierPluginForTesting().
+	//
+	// TODO: Remove this function once the RLS env var is removed.
+	UnregisterRLSClusterSpecifierPluginForTesting func()
+
+	// RegisterRBACHTTPFilterForTesting registers the RBAC HTTP Filter for testing
+	// purposes, regardless of the RBAC environment variable.
+	//
+	// TODO: Remove this function once the RBAC env var is removed.
+	RegisterRBACHTTPFilterForTesting func()
+
+	// UnregisterRBACHTTPFilterForTesting unregisters the RBAC HTTP Filter for
+	// testing purposes. This is needed because there is no way to unregister the
+	// HTTP Filter after registering it solely for testing purposes using
+	// RegisterRBACHTTPFilterForTesting().
+	//
+	// TODO: Remove this function once the RBAC env var is removed.
+	UnregisterRBACHTTPFilterForTesting func()
+
+	// ORCAAllowAnyMinReportingInterval is for examples/orca use ONLY.
+	ORCAAllowAnyMinReportingInterval interface{} // func(so *orca.ServiceOptions)
+)
+
+// HealthChecker defines the signature of the client-side LB channel health checking function.
+//
+// The implementation is expected to create a health checking RPC stream by
+// calling newStream(), watch for the health status of serviceName, and report
+// it's health back by calling setConnectivityState().
+//
+// The health checking protocol is defined at:
+// https://github.com/grpc/grpc/blob/master/doc/health-checking.md
+type HealthChecker func(ctx context.Context, newStream func(string) (interface{}, error), setConnectivityState func(connectivity.State, error), serviceName string) error
+
+const (
+	// CredsBundleModeFallback switches GoogleDefaultCreds to fallback mode.
+	CredsBundleModeFallback = "fallback"
+	// CredsBundleModeBalancer switches GoogleDefaultCreds to grpclb balancer
+	// mode.
+	CredsBundleModeBalancer = "balancer"
+	// CredsBundleModeBackendFromBalancer switches GoogleDefaultCreds to mode
+	// that supports backend returned by grpclb balancer.
+	CredsBundleModeBackendFromBalancer = "backend-from-balancer"
+)
+
+// RLSLoadBalancingPolicyName is the name of the RLS LB policy.
+//
+// It currently has an experimental suffix which would be removed once
+// end-to-end testing of the policy is completed.
+const RLSLoadBalancingPolicyName = "rls_experimental"

vendor/google.golang.org/grpc/internal/status/status.go

@@ -164,3 +164,13 @@ func (e *Error) Is(target error) bool {
 	}
 	return proto.Equal(e.s.s, tse.s.s)
 }
+
+// IsRestrictedControlPlaneCode returns whether the status includes a code
+// restricted for control plane usage as defined by gRFC A54.
+func IsRestrictedControlPlaneCode(s *Status) bool {
+	switch s.Code() {
+	case codes.InvalidArgument, codes.NotFound, codes.AlreadyExists, codes.FailedPrecondition, codes.Aborted, codes.OutOfRange, codes.DataLoss:
+		return true
+	}
+	return false
+}

vendor/google.golang.org/grpc/internal/xds_handshake_cluster.go

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2021 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package internal
+
+import (
+	"google.golang.org/grpc/attributes"
+	"google.golang.org/grpc/resolver"
+)
+
+// handshakeClusterNameKey is the type used as the key to store cluster name in
+// the Attributes field of resolver.Address.
+type handshakeClusterNameKey struct{}
+
+// SetXDSHandshakeClusterName returns a copy of addr in which the Attributes field
+// is updated with the cluster name.
+func SetXDSHandshakeClusterName(addr resolver.Address, clusterName string) resolver.Address {
+	addr.Attributes = addr.Attributes.WithValue(handshakeClusterNameKey{}, clusterName)
+	return addr
+}
+
+// GetXDSHandshakeClusterName returns cluster name stored in attr.
+func GetXDSHandshakeClusterName(attr *attributes.Attributes) (string, bool) {
+	v := attr.Value(handshakeClusterNameKey{})
+	name, ok := v.(string)
+	return name, ok
+}