TUN-8052: Update go to 1.21.5

Also update golang.org/x/net and google.golang.org/grpc to fix vulnerabilities,
although cloudflared is using them in a way that is not exposed to those risks

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

@@ -23,6 +23,8 @@
 package backoff
 
 import (
+	"context"
+	"errors"
 	"time"
 
 	grpcbackoff "google.golang.org/grpc/backoff"
@@ -71,3 +73,37 @@ func (bc Exponential) Backoff(retries int) time.Duration {
 	}
 	return time.Duration(backoff)
 }
+
+// ErrResetBackoff is the error to be returned by the function executed by RunF,
+// to instruct the latter to reset its backoff state.
+var ErrResetBackoff = errors.New("reset backoff state")
+
+// RunF provides a convenient way to run a function f repeatedly until the
+// context expires or f returns a non-nil error that is not ErrResetBackoff.
+// When f returns ErrResetBackoff, RunF continues to run f, but resets its
+// backoff state before doing so. backoff accepts an integer representing the
+// number of retries, and returns the amount of time to backoff.
+func RunF(ctx context.Context, f func() error, backoff func(int) time.Duration) {
+	attempt := 0
+	timer := time.NewTimer(0)
+	for ctx.Err() == nil {
+		select {
+		case <-timer.C:
+		case <-ctx.Done():
+			timer.Stop()
+			return
+		}
+
+		err := f()
+		if errors.Is(err, ErrResetBackoff) {
+			timer.Reset(0)
+			attempt = 0
+			continue
+		}
+		if err != nil {
+			return
+		}
+		timer.Reset(backoff(attempt))
+		attempt++
+	}
+}

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

@@ -200,8 +200,8 @@ func (gsb *Balancer) ExitIdle() {
 	}
 }
 
-// UpdateSubConnState forwards the update to the appropriate child.
-func (gsb *Balancer) UpdateSubConnState(sc balancer.SubConn, state balancer.SubConnState) {
+// updateSubConnState forwards the update to the appropriate child.
+func (gsb *Balancer) updateSubConnState(sc balancer.SubConn, state balancer.SubConnState, cb func(balancer.SubConnState)) {
 	gsb.currentMu.Lock()
 	defer gsb.currentMu.Unlock()
 	gsb.mu.Lock()
@@ -214,13 +214,26 @@ func (gsb *Balancer) UpdateSubConnState(sc balancer.SubConn, state balancer.SubC
 	} else if gsb.balancerPending != nil && gsb.balancerPending.subconns[sc] {
 		balToUpdate = gsb.balancerPending
 	}
-	gsb.mu.Unlock()
 	if balToUpdate == nil {
 		// SubConn belonged to a stale lb policy that has not yet fully closed,
 		// or the balancer was already closed.
+		gsb.mu.Unlock()
 		return
 	}
-	balToUpdate.UpdateSubConnState(sc, state)
+	if state.ConnectivityState == connectivity.Shutdown {
+		delete(balToUpdate.subconns, sc)
+	}
+	gsb.mu.Unlock()
+	if cb != nil {
+		cb(state)
+	} else {
+		balToUpdate.UpdateSubConnState(sc, state)
+	}
+}
+
+// UpdateSubConnState forwards the update to the appropriate child.
+func (gsb *Balancer) UpdateSubConnState(sc balancer.SubConn, state balancer.SubConnState) {
+	gsb.updateSubConnState(sc, state, nil)
 }
 
 // Close closes any active child balancers.
@@ -242,7 +255,7 @@ func (gsb *Balancer) Close() {
 //
 // It implements the balancer.ClientConn interface and is passed down in that
 // capacity to the wrapped balancer. It maintains a set of subConns created by
-// the wrapped balancer and calls from the latter to create/update/remove
+// the wrapped balancer and calls from the latter to create/update/shutdown
 // SubConns update this set before being forwarded to the parent ClientConn.
 // State updates from the wrapped balancer can result in invocation of the
 // graceful switch logic.
@@ -254,21 +267,10 @@ type balancerWrapper struct {
 	subconns  map[balancer.SubConn]bool // subconns created by this balancer
 }
 
-func (bw *balancerWrapper) UpdateSubConnState(sc balancer.SubConn, state balancer.SubConnState) {
-	if state.ConnectivityState == connectivity.Shutdown {
-		bw.gsb.mu.Lock()
-		delete(bw.subconns, sc)
-		bw.gsb.mu.Unlock()
-	}
-	// There is no need to protect this read with a mutex, as the write to the
-	// Balancer field happens in SwitchTo, which completes before this can be
-	// called.
-	bw.Balancer.UpdateSubConnState(sc, state)
-}
-
-// Close closes the underlying LB policy and removes the subconns it created. bw
-// must not be referenced via balancerCurrent or balancerPending in gsb when
-// called. gsb.mu must not be held.  Does not panic with a nil receiver.
+// Close closes the underlying LB policy and shuts down the subconns it
+// created. bw must not be referenced via balancerCurrent or balancerPending in
+// gsb when called. gsb.mu must not be held.  Does not panic with a nil
+// receiver.
 func (bw *balancerWrapper) Close() {
 	// before Close is called.
 	if bw == nil {
@@ -281,7 +283,7 @@ func (bw *balancerWrapper) Close() {
 	bw.Balancer.Close()
 	bw.gsb.mu.Lock()
 	for sc := range bw.subconns {
-		bw.gsb.cc.RemoveSubConn(sc)
+		sc.Shutdown()
 	}
 	bw.gsb.mu.Unlock()
 }
@@ -335,13 +337,16 @@ func (bw *balancerWrapper) NewSubConn(addrs []resolver.Address, opts balancer.Ne
 	}
 	bw.gsb.mu.Unlock()
 
+	var sc balancer.SubConn
+	oldListener := opts.StateListener
+	opts.StateListener = func(state balancer.SubConnState) { bw.gsb.updateSubConnState(sc, state, oldListener) }
 	sc, err := bw.gsb.cc.NewSubConn(addrs, opts)
 	if err != nil {
 		return nil, err
 	}
 	bw.gsb.mu.Lock()
 	if !bw.gsb.balancerCurrentOrPending(bw) { // balancer was closed during this call
-		bw.gsb.cc.RemoveSubConn(sc)
+		sc.Shutdown()
 		bw.gsb.mu.Unlock()
 		return nil, fmt.Errorf("%T at address %p that called NewSubConn is deleted", bw, bw)
 	}
@@ -360,13 +365,9 @@ func (bw *balancerWrapper) ResolveNow(opts resolver.ResolveNowOptions) {
 }
 
 func (bw *balancerWrapper) RemoveSubConn(sc balancer.SubConn) {
-	bw.gsb.mu.Lock()
-	if !bw.gsb.balancerCurrentOrPending(bw) {
-		bw.gsb.mu.Unlock()
-		return
-	}
-	bw.gsb.mu.Unlock()
-	bw.gsb.cc.RemoveSubConn(sc)
+	// Note: existing third party balancers may call this, so it must remain
+	// until RemoveSubConn is fully removed.
+	sc.Shutdown()
 }
 
 func (bw *balancerWrapper) UpdateAddresses(sc balancer.SubConn, addrs []resolver.Address) {

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

@@ -25,7 +25,7 @@ import (
 // Parser converts loads from metadata into a concrete type.
 type Parser interface {
 	// Parse parses loads from metadata.
-	Parse(md metadata.MD) interface{}
+	Parse(md metadata.MD) any
 }
 
 var parser Parser
@@ -38,7 +38,7 @@ func SetParser(lr Parser) {
 }
 
 // Parse calls parser.Read().
-func Parse(md metadata.MD) interface{} {
+func Parse(md metadata.MD) any {
 	if parser == nil {
 		return nil
 	}

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

@@ -28,8 +28,13 @@ import (
 	"google.golang.org/grpc/internal/grpcutil"
 )
 
-// Logger is the global binary logger. It can be used to get binary logger for
-// each method.
+var grpclogLogger = grpclog.Component("binarylog")
+
+// Logger specifies MethodLoggers for method names with a Log call that
+// takes a context.
+//
+// This is used in the 1.0 release of gcp/observability, and thus must not be
+// deleted or changed.
 type Logger interface {
 	GetMethodLogger(methodName string) MethodLogger
 }
@@ -40,8 +45,6 @@ type Logger interface {
 // It is used to get a MethodLogger for each individual method.
 var binLogger Logger
 
-var grpclogLogger = grpclog.Component("binarylog")
-
 // SetLogger sets the binary logger.
 //
 // Only call this at init time.

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

@@ -19,6 +19,7 @@
 package binarylog
 
 import (
+	"context"
 	"net"
 	"strings"
 	"sync/atomic"
@@ -26,7 +27,7 @@ import (
 
 	"github.com/golang/protobuf/proto"
 	"github.com/golang/protobuf/ptypes"
-	pb "google.golang.org/grpc/binarylog/grpc_binarylog_v1"
+	binlogpb "google.golang.org/grpc/binarylog/grpc_binarylog_v1"
 	"google.golang.org/grpc/metadata"
 	"google.golang.org/grpc/status"
 )
@@ -48,8 +49,11 @@ func (g *callIDGenerator) reset() {
 var idGen callIDGenerator
 
 // MethodLogger is the sub-logger for each method.
+//
+// This is used in the 1.0 release of gcp/observability, and thus must not be
+// deleted or changed.
 type MethodLogger interface {
-	Log(LogEntryConfig)
+	Log(context.Context, LogEntryConfig)
 }
 
 // TruncatingMethodLogger is a method logger that truncates headers and messages
@@ -64,6 +68,9 @@ type TruncatingMethodLogger struct {
 }
 
 // NewTruncatingMethodLogger returns a new truncating method logger.
+//
+// This is used in the 1.0 release of gcp/observability, and thus must not be
+// deleted or changed.
 func NewTruncatingMethodLogger(h, m uint64) *TruncatingMethodLogger {
 	return &TruncatingMethodLogger{
 		headerMaxLen:  h,
@@ -79,7 +86,7 @@ func NewTruncatingMethodLogger(h, m uint64) *TruncatingMethodLogger {
 // Build is an internal only method for building the proto message out of the
 // input event. It's made public to enable other library to reuse as much logic
 // in TruncatingMethodLogger as possible.
-func (ml *TruncatingMethodLogger) Build(c LogEntryConfig) *pb.GrpcLogEntry {
+func (ml *TruncatingMethodLogger) Build(c LogEntryConfig) *binlogpb.GrpcLogEntry {
 	m := c.toProto()
 	timestamp, _ := ptypes.TimestampProto(time.Now())
 	m.Timestamp = timestamp
@@ -87,22 +94,22 @@ func (ml *TruncatingMethodLogger) Build(c LogEntryConfig) *pb.GrpcLogEntry {
 	m.SequenceIdWithinCall = ml.idWithinCallGen.next()
 
 	switch pay := m.Payload.(type) {
-	case *pb.GrpcLogEntry_ClientHeader:
+	case *binlogpb.GrpcLogEntry_ClientHeader:
 		m.PayloadTruncated = ml.truncateMetadata(pay.ClientHeader.GetMetadata())
-	case *pb.GrpcLogEntry_ServerHeader:
+	case *binlogpb.GrpcLogEntry_ServerHeader:
 		m.PayloadTruncated = ml.truncateMetadata(pay.ServerHeader.GetMetadata())
-	case *pb.GrpcLogEntry_Message:
+	case *binlogpb.GrpcLogEntry_Message:
 		m.PayloadTruncated = ml.truncateMessage(pay.Message)
 	}
 	return m
 }
 
 // Log creates a proto binary log entry, and logs it to the sink.
-func (ml *TruncatingMethodLogger) Log(c LogEntryConfig) {
+func (ml *TruncatingMethodLogger) Log(ctx context.Context, c LogEntryConfig) {
 	ml.sink.Write(ml.Build(c))
 }
 
-func (ml *TruncatingMethodLogger) truncateMetadata(mdPb *pb.Metadata) (truncated bool) {
+func (ml *TruncatingMethodLogger) truncateMetadata(mdPb *binlogpb.Metadata) (truncated bool) {
 	if ml.headerMaxLen == maxUInt {
 		return false
 	}
@@ -121,7 +128,7 @@ func (ml *TruncatingMethodLogger) truncateMetadata(mdPb *pb.Metadata) (truncated
 			// but not counted towards the size limit.
 			continue
 		}
-		currentEntryLen := uint64(len(entry.Value))
+		currentEntryLen := uint64(len(entry.GetKey())) + uint64(len(entry.GetValue()))
 		if currentEntryLen > bytesLimit {
 			break
 		}
@@ -132,7 +139,7 @@ func (ml *TruncatingMethodLogger) truncateMetadata(mdPb *pb.Metadata) (truncated
 	return truncated
 }
 
-func (ml *TruncatingMethodLogger) truncateMessage(msgPb *pb.Message) (truncated bool) {
+func (ml *TruncatingMethodLogger) truncateMessage(msgPb *binlogpb.Message) (truncated bool) {
 	if ml.messageMaxLen == maxUInt {
 		return false
 	}
@@ -144,8 +151,11 @@ func (ml *TruncatingMethodLogger) truncateMessage(msgPb *pb.Message) (truncated
 }
 
 // LogEntryConfig represents the configuration for binary log entry.
+//
+// This is used in the 1.0 release of gcp/observability, and thus must not be
+// deleted or changed.
 type LogEntryConfig interface {
-	toProto() *pb.GrpcLogEntry
+	toProto() *binlogpb.GrpcLogEntry
 }
 
 // ClientHeader configs the binary log entry to be a ClientHeader entry.
@@ -159,10 +169,10 @@ type ClientHeader struct {
 	PeerAddr net.Addr
 }
 
-func (c *ClientHeader) toProto() *pb.GrpcLogEntry {
+func (c *ClientHeader) toProto() *binlogpb.GrpcLogEntry {
 	// This function doesn't need to set all the fields (e.g. seq ID). The Log
 	// function will set the fields when necessary.
-	clientHeader := &pb.ClientHeader{
+	clientHeader := &binlogpb.ClientHeader{
 		Metadata:   mdToMetadataProto(c.Header),
 		MethodName: c.MethodName,
 		Authority:  c.Authority,
@@ -170,16 +180,16 @@ func (c *ClientHeader) toProto() *pb.GrpcLogEntry {
 	if c.Timeout > 0 {
 		clientHeader.Timeout = ptypes.DurationProto(c.Timeout)
 	}
-	ret := &pb.GrpcLogEntry{
-		Type: pb.GrpcLogEntry_EVENT_TYPE_CLIENT_HEADER,
-		Payload: &pb.GrpcLogEntry_ClientHeader{
+	ret := &binlogpb.GrpcLogEntry{
+		Type: binlogpb.GrpcLogEntry_EVENT_TYPE_CLIENT_HEADER,
+		Payload: &binlogpb.GrpcLogEntry_ClientHeader{
 			ClientHeader: clientHeader,
 		},
 	}
 	if c.OnClientSide {
-		ret.Logger = pb.GrpcLogEntry_LOGGER_CLIENT
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_CLIENT
 	} else {
-		ret.Logger = pb.GrpcLogEntry_LOGGER_SERVER
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_SERVER
 	}
 	if c.PeerAddr != nil {
 		ret.Peer = addrToProto(c.PeerAddr)
@@ -195,19 +205,19 @@ type ServerHeader struct {
 	PeerAddr net.Addr
 }
 
-func (c *ServerHeader) toProto() *pb.GrpcLogEntry {
-	ret := &pb.GrpcLogEntry{
-		Type: pb.GrpcLogEntry_EVENT_TYPE_SERVER_HEADER,
-		Payload: &pb.GrpcLogEntry_ServerHeader{
-			ServerHeader: &pb.ServerHeader{
+func (c *ServerHeader) toProto() *binlogpb.GrpcLogEntry {
+	ret := &binlogpb.GrpcLogEntry{
+		Type: binlogpb.GrpcLogEntry_EVENT_TYPE_SERVER_HEADER,
+		Payload: &binlogpb.GrpcLogEntry_ServerHeader{
+			ServerHeader: &binlogpb.ServerHeader{
 				Metadata: mdToMetadataProto(c.Header),
 			},
 		},
 	}
 	if c.OnClientSide {
-		ret.Logger = pb.GrpcLogEntry_LOGGER_CLIENT
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_CLIENT
 	} else {
-		ret.Logger = pb.GrpcLogEntry_LOGGER_SERVER
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_SERVER
 	}
 	if c.PeerAddr != nil {
 		ret.Peer = addrToProto(c.PeerAddr)
@@ -220,10 +230,10 @@ type ClientMessage struct {
 	OnClientSide bool
 	// Message can be a proto.Message or []byte. Other messages formats are not
 	// supported.
-	Message interface{}
+	Message any
 }
 
-func (c *ClientMessage) toProto() *pb.GrpcLogEntry {
+func (c *ClientMessage) toProto() *binlogpb.GrpcLogEntry {
 	var (
 		data []byte
 		err  error
@@ -238,19 +248,19 @@ func (c *ClientMessage) toProto() *pb.GrpcLogEntry {
 	} else {
 		grpclogLogger.Infof("binarylogging: message to log is neither proto.message nor []byte")
 	}
-	ret := &pb.GrpcLogEntry{
-		Type: pb.GrpcLogEntry_EVENT_TYPE_CLIENT_MESSAGE,
-		Payload: &pb.GrpcLogEntry_Message{
-			Message: &pb.Message{
+	ret := &binlogpb.GrpcLogEntry{
+		Type: binlogpb.GrpcLogEntry_EVENT_TYPE_CLIENT_MESSAGE,
+		Payload: &binlogpb.GrpcLogEntry_Message{
+			Message: &binlogpb.Message{
 				Length: uint32(len(data)),
 				Data:   data,
 			},
 		},
 	}
 	if c.OnClientSide {
-		ret.Logger = pb.GrpcLogEntry_LOGGER_CLIENT
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_CLIENT
 	} else {
-		ret.Logger = pb.GrpcLogEntry_LOGGER_SERVER
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_SERVER
 	}
 	return ret
 }
@@ -260,10 +270,10 @@ type ServerMessage struct {
 	OnClientSide bool
 	// Message can be a proto.Message or []byte. Other messages formats are not
 	// supported.
-	Message interface{}
+	Message any
 }
 
-func (c *ServerMessage) toProto() *pb.GrpcLogEntry {
+func (c *ServerMessage) toProto() *binlogpb.GrpcLogEntry {
 	var (
 		data []byte
 		err  error
@@ -278,19 +288,19 @@ func (c *ServerMessage) toProto() *pb.GrpcLogEntry {
 	} else {
 		grpclogLogger.Infof("binarylogging: message to log is neither proto.message nor []byte")
 	}
-	ret := &pb.GrpcLogEntry{
-		Type: pb.GrpcLogEntry_EVENT_TYPE_SERVER_MESSAGE,
-		Payload: &pb.GrpcLogEntry_Message{
-			Message: &pb.Message{
+	ret := &binlogpb.GrpcLogEntry{
+		Type: binlogpb.GrpcLogEntry_EVENT_TYPE_SERVER_MESSAGE,
+		Payload: &binlogpb.GrpcLogEntry_Message{
+			Message: &binlogpb.Message{
 				Length: uint32(len(data)),
 				Data:   data,
 			},
 		},
 	}
 	if c.OnClientSide {
-		ret.Logger = pb.GrpcLogEntry_LOGGER_CLIENT
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_CLIENT
 	} else {
-		ret.Logger = pb.GrpcLogEntry_LOGGER_SERVER
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_SERVER
 	}
 	return ret
 }
@@ -300,15 +310,15 @@ type ClientHalfClose struct {
 	OnClientSide bool
 }
 
-func (c *ClientHalfClose) toProto() *pb.GrpcLogEntry {
-	ret := &pb.GrpcLogEntry{
-		Type:    pb.GrpcLogEntry_EVENT_TYPE_CLIENT_HALF_CLOSE,
+func (c *ClientHalfClose) toProto() *binlogpb.GrpcLogEntry {
+	ret := &binlogpb.GrpcLogEntry{
+		Type:    binlogpb.GrpcLogEntry_EVENT_TYPE_CLIENT_HALF_CLOSE,
 		Payload: nil, // No payload here.
 	}
 	if c.OnClientSide {
-		ret.Logger = pb.GrpcLogEntry_LOGGER_CLIENT
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_CLIENT
 	} else {
-		ret.Logger = pb.GrpcLogEntry_LOGGER_SERVER
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_SERVER
 	}
 	return ret
 }
@@ -324,7 +334,7 @@ type ServerTrailer struct {
 	PeerAddr net.Addr
 }
 
-func (c *ServerTrailer) toProto() *pb.GrpcLogEntry {
+func (c *ServerTrailer) toProto() *binlogpb.GrpcLogEntry {
 	st, ok := status.FromError(c.Err)
 	if !ok {
 		grpclogLogger.Info("binarylogging: error in trailer is not a status error")
@@ -340,10 +350,10 @@ func (c *ServerTrailer) toProto() *pb.GrpcLogEntry {
 			grpclogLogger.Infof("binarylogging: failed to marshal status proto: %v", err)
 		}
 	}
-	ret := &pb.GrpcLogEntry{
-		Type: pb.GrpcLogEntry_EVENT_TYPE_SERVER_TRAILER,
-		Payload: &pb.GrpcLogEntry_Trailer{
-			Trailer: &pb.Trailer{
+	ret := &binlogpb.GrpcLogEntry{
+		Type: binlogpb.GrpcLogEntry_EVENT_TYPE_SERVER_TRAILER,
+		Payload: &binlogpb.GrpcLogEntry_Trailer{
+			Trailer: &binlogpb.Trailer{
 				Metadata:      mdToMetadataProto(c.Trailer),
 				StatusCode:    uint32(st.Code()),
 				StatusMessage: st.Message(),
@@ -352,9 +362,9 @@ func (c *ServerTrailer) toProto() *pb.GrpcLogEntry {
 		},
 	}
 	if c.OnClientSide {
-		ret.Logger = pb.GrpcLogEntry_LOGGER_CLIENT
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_CLIENT
 	} else {
-		ret.Logger = pb.GrpcLogEntry_LOGGER_SERVER
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_SERVER
 	}
 	if c.PeerAddr != nil {
 		ret.Peer = addrToProto(c.PeerAddr)
@@ -367,15 +377,15 @@ type Cancel struct {
 	OnClientSide bool
 }
 
-func (c *Cancel) toProto() *pb.GrpcLogEntry {
-	ret := &pb.GrpcLogEntry{
-		Type:    pb.GrpcLogEntry_EVENT_TYPE_CANCEL,
+func (c *Cancel) toProto() *binlogpb.GrpcLogEntry {
+	ret := &binlogpb.GrpcLogEntry{
+		Type:    binlogpb.GrpcLogEntry_EVENT_TYPE_CANCEL,
 		Payload: nil,
 	}
 	if c.OnClientSide {
-		ret.Logger = pb.GrpcLogEntry_LOGGER_CLIENT
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_CLIENT
 	} else {
-		ret.Logger = pb.GrpcLogEntry_LOGGER_SERVER
+		ret.Logger = binlogpb.GrpcLogEntry_LOGGER_SERVER
 	}
 	return ret
 }
@@ -392,15 +402,15 @@ func metadataKeyOmit(key string) bool {
 	return strings.HasPrefix(key, "grpc-")
 }
 
-func mdToMetadataProto(md metadata.MD) *pb.Metadata {
-	ret := &pb.Metadata{}
+func mdToMetadataProto(md metadata.MD) *binlogpb.Metadata {
+	ret := &binlogpb.Metadata{}
 	for k, vv := range md {
 		if metadataKeyOmit(k) {
 			continue
 		}
 		for _, v := range vv {
 			ret.Entry = append(ret.Entry,
-				&pb.MetadataEntry{
+				&binlogpb.MetadataEntry{
 					Key:   k,
 					Value: []byte(v),
 				},
@@ -410,26 +420,26 @@ func mdToMetadataProto(md metadata.MD) *pb.Metadata {
 	return ret
 }
 
-func addrToProto(addr net.Addr) *pb.Address {
-	ret := &pb.Address{}
+func addrToProto(addr net.Addr) *binlogpb.Address {
+	ret := &binlogpb.Address{}
 	switch a := addr.(type) {
 	case *net.TCPAddr:
 		if a.IP.To4() != nil {
-			ret.Type = pb.Address_TYPE_IPV4
+			ret.Type = binlogpb.Address_TYPE_IPV4
 		} else if a.IP.To16() != nil {
-			ret.Type = pb.Address_TYPE_IPV6
+			ret.Type = binlogpb.Address_TYPE_IPV6
 		} else {
-			ret.Type = pb.Address_TYPE_UNKNOWN
+			ret.Type = binlogpb.Address_TYPE_UNKNOWN
 			// Do not set address and port fields.
 			break
 		}
 		ret.Address = a.IP.String()
 		ret.IpPort = uint32(a.Port)
 	case *net.UnixAddr:
-		ret.Type = pb.Address_TYPE_UNIX
+		ret.Type = binlogpb.Address_TYPE_UNIX
 		ret.Address = a.String()
 	default:
-		ret.Type = pb.Address_TYPE_UNKNOWN
+		ret.Type = binlogpb.Address_TYPE_UNKNOWN
 	}
 	return ret
 }

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

@@ -26,7 +26,7 @@ import (
 	"time"
 
 	"github.com/golang/protobuf/proto"
-	pb "google.golang.org/grpc/binarylog/grpc_binarylog_v1"
+	binlogpb "google.golang.org/grpc/binarylog/grpc_binarylog_v1"
 )
 
 var (
@@ -42,15 +42,15 @@ type Sink interface {
 	// Write will be called to write the log entry into the sink.
 	//
 	// It should be thread-safe so it can be called in parallel.
-	Write(*pb.GrpcLogEntry) error
+	Write(*binlogpb.GrpcLogEntry) error
 	// Close will be called when the Sink is replaced by a new Sink.
 	Close() error
 }
 
 type noopSink struct{}
 
-func (ns *noopSink) Write(*pb.GrpcLogEntry) error { return nil }
-func (ns *noopSink) Close() error                 { return nil }
+func (ns *noopSink) Write(*binlogpb.GrpcLogEntry) error { return nil }
+func (ns *noopSink) Close() error                       { return nil }
 
 // newWriterSink creates a binary log sink with the given writer.
 //
@@ -66,7 +66,7 @@ type writerSink struct {
 	out io.Writer
 }
 
-func (ws *writerSink) Write(e *pb.GrpcLogEntry) error {
+func (ws *writerSink) Write(e *binlogpb.GrpcLogEntry) error {
 	b, err := proto.Marshal(e)
 	if err != nil {
 		grpclogLogger.Errorf("binary logging: failed to marshal proto message: %v", err)
@@ -96,7 +96,7 @@ type bufferedSink struct {
 	done        chan struct{}
 }
 
-func (fs *bufferedSink) Write(e *pb.GrpcLogEntry) error {
+func (fs *bufferedSink) Write(e *binlogpb.GrpcLogEntry) error {
 	fs.mu.Lock()
 	defer fs.mu.Unlock()
 	if !fs.flusherStarted {

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

@@ -18,7 +18,10 @@
 // Package buffer provides an implementation of an unbounded buffer.
 package buffer
 
-import "sync"
+import (
+	"errors"
+	"sync"
+)
 
 // Unbounded is an implementation of an unbounded buffer which does not use
 // extra goroutines. This is typically used for passing updates from one entity
@@ -28,42 +31,50 @@ import "sync"
 // the underlying mutex used for synchronization.
 //
 // Unbounded supports values of any type to be stored in it by using a channel
-// of `interface{}`. This means that a call to Put() incurs an extra memory
-// allocation, and also that users need a type assertion while reading. For
-// performance critical code paths, using Unbounded is strongly discouraged and
-// defining a new type specific implementation of this buffer is preferred. See
+// of `any`. This means that a call to Put() incurs an extra memory allocation,
+// and also that users need a type assertion while reading. For performance
+// critical code paths, using Unbounded is strongly discouraged and defining a
+// new type specific implementation of this buffer is preferred. See
 // internal/transport/transport.go for an example of this.
 type Unbounded struct {
-	c       chan interface{}
+	c       chan any
+	closed  bool
+	closing bool
 	mu      sync.Mutex
-	backlog []interface{}
+	backlog []any
 }
 
 // NewUnbounded returns a new instance of Unbounded.
 func NewUnbounded() *Unbounded {
-	return &Unbounded{c: make(chan interface{}, 1)}
+	return &Unbounded{c: make(chan any, 1)}
 }
 
+var errBufferClosed = errors.New("Put called on closed buffer.Unbounded")
+
 // Put adds t to the unbounded buffer.
-func (b *Unbounded) Put(t interface{}) {
+func (b *Unbounded) Put(t any) error {
 	b.mu.Lock()
+	defer b.mu.Unlock()
+	if b.closing {
+		return errBufferClosed
+	}
 	if len(b.backlog) == 0 {
 		select {
 		case b.c <- t:
-			b.mu.Unlock()
-			return
+			return nil
 		default:
 		}
 	}
 	b.backlog = append(b.backlog, t)
-	b.mu.Unlock()
+	return nil
 }
 
-// Load sends the earliest buffered data, if any, onto the read channel
-// returned by Get(). Users are expected to call this every time they read a
+// Load sends the earliest buffered data, if any, onto the read channel returned
+// by Get(). Users are expected to call this every time they successfully read a
 // value from the read channel.
 func (b *Unbounded) Load() {
 	b.mu.Lock()
+	defer b.mu.Unlock()
 	if len(b.backlog) > 0 {
 		select {
 		case b.c <- b.backlog[0]:
@@ -71,8 +82,9 @@ func (b *Unbounded) Load() {
 			b.backlog = b.backlog[1:]
 		default:
 		}
+	} else if b.closing && !b.closed {
+		close(b.c)
 	}
-	b.mu.Unlock()
 }
 
 // Get returns a read channel on which values added to the buffer, via Put(),
@@ -80,6 +92,25 @@ func (b *Unbounded) Load() {
 //
 // Upon reading a value from this channel, users are expected to call Load() to
 // send the next buffered value onto the channel if there is any.
-func (b *Unbounded) Get() <-chan interface{} {
+//
+// If the unbounded buffer is closed, the read channel returned by this method
+// is closed after all data is drained.
+func (b *Unbounded) Get() <-chan any {
 	return b.c
 }
+
+// Close closes the unbounded buffer. No subsequent data may be Put(), and the
+// channel returned from Get() will be closed after all the data is read and
+// Load() is called for the final time.
+func (b *Unbounded) Close() {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	if b.closing {
+		return
+	}
+	b.closing = true
+	if len(b.backlog) == 0 {
+		b.closed = true
+		close(b.c)
+	}
+}

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

@@ -24,15 +24,14 @@
 package channelz
 
 import (
-	"context"
 	"errors"
-	"fmt"
 	"sort"
 	"sync"
 	"sync/atomic"
 	"time"
 
 	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/internal"
 )
 
 const (
@@ -40,8 +39,11 @@ const (
 )
 
 var (
-	db    dbWrapper
-	idGen idGenerator
+	// IDGen is the global channelz entity ID generator.  It should not be used
+	// outside this package except by tests.
+	IDGen IDGenerator
+
+	db dbWrapper
 	// EntryPerPage defines the number of channelz entries to be shown on a web page.
 	EntryPerPage  = int64(50)
 	curState      int32
@@ -52,14 +54,20 @@ var (
 func TurnOn() {
 	if !IsOn() {
 		db.set(newChannelMap())
-		idGen.reset()
+		IDGen.Reset()
 		atomic.StoreInt32(&curState, 1)
 	}
 }
 
+func init() {
+	internal.ChannelzTurnOffForTesting = func() {
+		atomic.StoreInt32(&curState, 0)
+	}
+}
+
 // IsOn returns whether channelz data collection is on.
 func IsOn() bool {
-	return atomic.CompareAndSwapInt32(&curState, 1, 1)
+	return atomic.LoadInt32(&curState) == 1
 }
 
 // SetMaxTraceEntry sets maximum number of trace entry per entity (i.e. channel/subchannel).
@@ -97,43 +105,6 @@ func (d *dbWrapper) get() *channelMap {
 	return d.DB
 }
 
-// NewChannelzStorageForTesting initializes channelz data storage and id
-// generator for testing purposes.
-//
-// Returns a cleanup function to be invoked by the test, which waits for up to
-// 10s for all channelz state to be reset by the grpc goroutines when those
-// entities get closed. This cleanup function helps with ensuring that tests
-// don't mess up each other.
-func NewChannelzStorageForTesting() (cleanup func() error) {
-	db.set(newChannelMap())
-	idGen.reset()
-
-	return func() error {
-		cm := db.get()
-		if cm == nil {
-			return nil
-		}
-
-		ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
-		defer cancel()
-		ticker := time.NewTicker(10 * time.Millisecond)
-		defer ticker.Stop()
-		for {
-			cm.mu.RLock()
-			topLevelChannels, servers, channels, subChannels, listenSockets, normalSockets := len(cm.topLevelChannels), len(cm.servers), len(cm.channels), len(cm.subChannels), len(cm.listenSockets), len(cm.normalSockets)
-			cm.mu.RUnlock()
-
-			if err := ctx.Err(); err != nil {
-				return fmt.Errorf("after 10s the channelz map has not been cleaned up yet, topchannels: %d, servers: %d, channels: %d, subchannels: %d, listen sockets: %d, normal sockets: %d", topLevelChannels, servers, channels, subChannels, listenSockets, normalSockets)
-			}
-			if topLevelChannels == 0 && servers == 0 && channels == 0 && subChannels == 0 && listenSockets == 0 && normalSockets == 0 {
-				return nil
-			}
-			<-ticker.C
-		}
-	}
-}
-
 // GetTopChannels returns a slice of top channel's ChannelMetric, along with a
 // boolean indicating whether there's more top channels to be queried for.
 //
@@ -193,7 +164,7 @@ func GetServer(id int64) *ServerMetric {
 //
 // If channelz is not turned ON, the channelz database is not mutated.
 func RegisterChannel(c Channel, pid *Identifier, ref string) *Identifier {
-	id := idGen.genID()
+	id := IDGen.genID()
 	var parent int64
 	isTopChannel := true
 	if pid != nil {
@@ -229,7 +200,7 @@ func RegisterSubChannel(c Channel, pid *Identifier, ref string) (*Identifier, er
 	if pid == nil {
 		return nil, errors.New("a SubChannel's parent id cannot be nil")
 	}
-	id := idGen.genID()
+	id := IDGen.genID()
 	if !IsOn() {
 		return newIdentifer(RefSubChannel, id, pid), nil
 	}
@@ -251,7 +222,7 @@ func RegisterSubChannel(c Channel, pid *Identifier, ref string) (*Identifier, er
 //
 // If channelz is not turned ON, the channelz database is not mutated.
 func RegisterServer(s Server, ref string) *Identifier {
-	id := idGen.genID()
+	id := IDGen.genID()
 	if !IsOn() {
 		return newIdentifer(RefServer, id, nil)
 	}
@@ -277,7 +248,7 @@ func RegisterListenSocket(s Socket, pid *Identifier, ref string) (*Identifier, e
 	if pid == nil {
 		return nil, errors.New("a ListenSocket's parent id cannot be 0")
 	}
-	id := idGen.genID()
+	id := IDGen.genID()
 	if !IsOn() {
 		return newIdentifer(RefListenSocket, id, pid), nil
 	}
@@ -297,7 +268,7 @@ func RegisterNormalSocket(s Socket, pid *Identifier, ref string) (*Identifier, e
 	if pid == nil {
 		return nil, errors.New("a NormalSocket's parent id cannot be 0")
 	}
-	id := idGen.genID()
+	id := IDGen.genID()
 	if !IsOn() {
 		return newIdentifer(RefNormalSocket, id, pid), nil
 	}
@@ -776,14 +747,17 @@ func (c *channelMap) GetServer(id int64) *ServerMetric {
 	return sm
 }
 
-type idGenerator struct {
+// IDGenerator is an incrementing atomic that tracks IDs for channelz entities.
+type IDGenerator struct {
 	id int64
 }
 
-func (i *idGenerator) reset() {
+// Reset resets the generated ID back to zero.  Should only be used at
+// initialization or by tests sensitive to the ID number.
+func (i *IDGenerator) Reset() {
 	atomic.StoreInt64(&i.id, 0)
 }
 
-func (i *idGenerator) genID() int64 {
+func (i *IDGenerator) genID() int64 {
 	return atomic.AddInt64(&i.id, 1)
 }

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

@@ -31,7 +31,7 @@ func withParens(id *Identifier) string {
 }
 
 // Info logs and adds a trace event if channelz is on.
-func Info(l grpclog.DepthLoggerV2, id *Identifier, args ...interface{}) {
+func Info(l grpclog.DepthLoggerV2, id *Identifier, args ...any) {
 	AddTraceEvent(l, id, 1, &TraceEventDesc{
 		Desc:     fmt.Sprint(args...),
 		Severity: CtInfo,
@@ -39,7 +39,7 @@ func Info(l grpclog.DepthLoggerV2, id *Identifier, args ...interface{}) {
 }
 
 // Infof logs and adds a trace event if channelz is on.
-func Infof(l grpclog.DepthLoggerV2, id *Identifier, format string, args ...interface{}) {
+func Infof(l grpclog.DepthLoggerV2, id *Identifier, format string, args ...any) {
 	AddTraceEvent(l, id, 1, &TraceEventDesc{
 		Desc:     fmt.Sprintf(format, args...),
 		Severity: CtInfo,
@@ -47,7 +47,7 @@ func Infof(l grpclog.DepthLoggerV2, id *Identifier, format string, args ...inter
 }
 
 // Warning logs and adds a trace event if channelz is on.
-func Warning(l grpclog.DepthLoggerV2, id *Identifier, args ...interface{}) {
+func Warning(l grpclog.DepthLoggerV2, id *Identifier, args ...any) {
 	AddTraceEvent(l, id, 1, &TraceEventDesc{
 		Desc:     fmt.Sprint(args...),
 		Severity: CtWarning,
@@ -55,7 +55,7 @@ func Warning(l grpclog.DepthLoggerV2, id *Identifier, args ...interface{}) {
 }
 
 // Warningf logs and adds a trace event if channelz is on.
-func Warningf(l grpclog.DepthLoggerV2, id *Identifier, format string, args ...interface{}) {
+func Warningf(l grpclog.DepthLoggerV2, id *Identifier, format string, args ...any) {
 	AddTraceEvent(l, id, 1, &TraceEventDesc{
 		Desc:     fmt.Sprintf(format, args...),
 		Severity: CtWarning,
@@ -63,7 +63,7 @@ func Warningf(l grpclog.DepthLoggerV2, id *Identifier, format string, args ...in
 }
 
 // Error logs and adds a trace event if channelz is on.
-func Error(l grpclog.DepthLoggerV2, id *Identifier, args ...interface{}) {
+func Error(l grpclog.DepthLoggerV2, id *Identifier, args ...any) {
 	AddTraceEvent(l, id, 1, &TraceEventDesc{
 		Desc:     fmt.Sprint(args...),
 		Severity: CtError,
@@ -71,7 +71,7 @@ func Error(l grpclog.DepthLoggerV2, id *Identifier, args ...interface{}) {
 }
 
 // Errorf logs and adds a trace event if channelz is on.
-func Errorf(l grpclog.DepthLoggerV2, id *Identifier, format string, args ...interface{}) {
+func Errorf(l grpclog.DepthLoggerV2, id *Identifier, format string, args ...any) {
 	AddTraceEvent(l, id, 1, &TraceEventDesc{
 		Desc:     fmt.Sprintf(format, args...),
 		Severity: CtError,

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

@@ -628,6 +628,7 @@ type tracedChannel interface {
 
 type channelTrace struct {
 	cm          *channelMap
+	clearCalled bool
 	createdTime time.Time
 	eventCount  int64
 	mu          sync.Mutex
@@ -656,6 +657,10 @@ func (c *channelTrace) append(e *TraceEvent) {
 }
 
 func (c *channelTrace) clear() {
+	if c.clearCalled {
+		return
+	}
+	c.clearCalled = true
 	c.mu.Lock()
 	for _, e := range c.events {
 		if e.RefID != 0 {

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

@@ -23,7 +23,7 @@ import (
 )
 
 // GetSocketOption gets the socket option info of the conn.
-func GetSocketOption(socket interface{}) *SocketOptionData {
+func GetSocketOption(socket any) *SocketOptionData {
 	c, ok := socket.(syscall.Conn)
 	if !ok {
 		return nil

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

@@ -22,6 +22,6 @@
 package channelz
 
 // GetSocketOption gets the socket option info of the conn.
-func GetSocketOption(c interface{}) *SocketOptionData {
+func GetSocketOption(c any) *SocketOptionData {
 	return nil
 }

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

@@ -25,12 +25,12 @@ import (
 type requestInfoKey struct{}
 
 // NewRequestInfoContext creates a context with ri.
-func NewRequestInfoContext(ctx context.Context, ri interface{}) context.Context {
+func NewRequestInfoContext(ctx context.Context, ri any) context.Context {
 	return context.WithValue(ctx, requestInfoKey{}, ri)
 }
 
 // RequestInfoFromContext extracts the RequestInfo from ctx.
-func RequestInfoFromContext(ctx context.Context) interface{} {
+func RequestInfoFromContext(ctx context.Context) any {
 	return ctx.Value(requestInfoKey{})
 }
 
@@ -39,11 +39,11 @@ func RequestInfoFromContext(ctx context.Context) interface{} {
 type clientHandshakeInfoKey struct{}
 
 // ClientHandshakeInfoFromContext extracts the ClientHandshakeInfo from ctx.
-func ClientHandshakeInfoFromContext(ctx context.Context) interface{} {
+func ClientHandshakeInfoFromContext(ctx context.Context) any {
 	return ctx.Value(clientHandshakeInfoKey{})
 }
 
 // NewClientHandshakeInfoContext creates a context with chi.
-func NewClientHandshakeInfoContext(ctx context.Context, chi interface{}) context.Context {
+func NewClientHandshakeInfoContext(ctx context.Context, chi any) context.Context {
 	return context.WithValue(ctx, clientHandshakeInfoKey{}, chi)
 }

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

@@ -21,19 +21,49 @@ package envconfig
 
 import (
 	"os"
+	"strconv"
 	"strings"
 )
 
-const (
-	prefix                  = "GRPC_GO_"
-	txtErrIgnoreStr         = prefix + "IGNORE_TXT_ERRORS"
-	advertiseCompressorsStr = prefix + "ADVERTISE_COMPRESSORS"
-)
-
 var (
 	// TXTErrIgnore is set if TXT errors should be ignored ("GRPC_GO_IGNORE_TXT_ERRORS" is not "false").
-	TXTErrIgnore = !strings.EqualFold(os.Getenv(txtErrIgnoreStr), "false")
+	TXTErrIgnore = boolFromEnv("GRPC_GO_IGNORE_TXT_ERRORS", true)
 	// AdvertiseCompressors is set if registered compressor should be advertised
 	// ("GRPC_GO_ADVERTISE_COMPRESSORS" is not "false").
-	AdvertiseCompressors = !strings.EqualFold(os.Getenv(advertiseCompressorsStr), "false")
+	AdvertiseCompressors = boolFromEnv("GRPC_GO_ADVERTISE_COMPRESSORS", true)
+	// RingHashCap indicates the maximum ring size which defaults to 4096
+	// entries but may be overridden by setting the environment variable
+	// "GRPC_RING_HASH_CAP".  This does not override the default bounds
+	// checking which NACKs configs specifying ring sizes > 8*1024*1024 (~8M).
+	RingHashCap = uint64FromEnv("GRPC_RING_HASH_CAP", 4096, 1, 8*1024*1024)
+	// LeastRequestLB is set if we should support the least_request_experimental
+	// LB policy, which can be enabled by setting the environment variable
+	// "GRPC_EXPERIMENTAL_ENABLE_LEAST_REQUEST" to "true".
+	LeastRequestLB = boolFromEnv("GRPC_EXPERIMENTAL_ENABLE_LEAST_REQUEST", false)
+	// ALTSMaxConcurrentHandshakes is the maximum number of concurrent ALTS
+	// handshakes that can be performed.
+	ALTSMaxConcurrentHandshakes = uint64FromEnv("GRPC_ALTS_MAX_CONCURRENT_HANDSHAKES", 100, 1, 100)
 )
+
+func boolFromEnv(envVar string, def bool) bool {
+	if def {
+		// The default is true; return true unless the variable is "false".
+		return !strings.EqualFold(os.Getenv(envVar), "false")
+	}
+	// The default is false; return false unless the variable is "true".
+	return strings.EqualFold(os.Getenv(envVar), "true")
+}
+
+func uint64FromEnv(envVar string, def, min, max uint64) uint64 {
+	v, err := strconv.ParseUint(os.Getenv(envVar), 10, 64)
+	if err != nil {
+		return def
+	}
+	if v < min {
+		return min
+	}
+	if v > max {
+		return max
+	}
+	return v
+}

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

@@ -28,9 +28,15 @@ const (
 var (
 	// ObservabilityConfig is the json configuration for the gcp/observability
 	// package specified directly in the envObservabilityConfig env var.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
 	ObservabilityConfig = os.Getenv(envObservabilityConfig)
 	// ObservabilityConfigFile is the json configuration for the
 	// gcp/observability specified in a file with the location specified in
 	// envObservabilityConfigFile env var.
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
 	ObservabilityConfigFile = os.Getenv(envObservabilityConfigFile)
 )

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

@@ -20,7 +20,6 @@ package envconfig
 
 import (
 	"os"
-	"strings"
 )
 
 const (
@@ -36,16 +35,6 @@ const (
 	//
 	// When both bootstrap FileName and FileContent are set, FileName is used.
 	XDSBootstrapFileContentEnv = "GRPC_XDS_BOOTSTRAP_CONFIG"
-
-	ringHashSupportEnv           = "GRPC_XDS_EXPERIMENTAL_ENABLE_RING_HASH"
-	clientSideSecuritySupportEnv = "GRPC_XDS_EXPERIMENTAL_SECURITY_SUPPORT"
-	aggregateAndDNSSupportEnv    = "GRPC_XDS_EXPERIMENTAL_ENABLE_AGGREGATE_AND_LOGICAL_DNS_CLUSTER"
-	rbacSupportEnv               = "GRPC_XDS_EXPERIMENTAL_RBAC"
-	outlierDetectionSupportEnv   = "GRPC_EXPERIMENTAL_ENABLE_OUTLIER_DETECTION"
-	federationEnv                = "GRPC_EXPERIMENTAL_XDS_FEDERATION"
-	rlsInXDSEnv                  = "GRPC_EXPERIMENTAL_XDS_RLS_LB"
-
-	c2pResolverTestOnlyTrafficDirectorURIEnv = "GRPC_TEST_ONLY_GOOGLE_C2P_RESOLVER_TRAFFIC_DIRECTOR_URI"
 )
 
 var (
@@ -61,41 +50,7 @@ var (
 	//
 	// When both bootstrap FileName and FileContent are set, FileName is used.
 	XDSBootstrapFileContent = os.Getenv(XDSBootstrapFileContentEnv)
-	// XDSRingHash indicates whether ring hash support is enabled, which can be
-	// disabled by setting the environment variable
-	// "GRPC_XDS_EXPERIMENTAL_ENABLE_RING_HASH" to "false".
-	XDSRingHash = !strings.EqualFold(os.Getenv(ringHashSupportEnv), "false")
-	// XDSClientSideSecurity is used to control processing of security
-	// configuration on the client-side.
-	//
-	// Note that there is no env var protection for the server-side because we
-	// have a brand new API on the server-side and users explicitly need to use
-	// the new API to get security integration on the server.
-	XDSClientSideSecurity = !strings.EqualFold(os.Getenv(clientSideSecuritySupportEnv), "false")
-	// XDSAggregateAndDNS indicates whether processing of aggregated cluster
-	// and DNS cluster is enabled, which can be enabled by setting the
-	// environment variable
-	// "GRPC_XDS_EXPERIMENTAL_ENABLE_AGGREGATE_AND_LOGICAL_DNS_CLUSTER" to
-	// "true".
-	XDSAggregateAndDNS = !strings.EqualFold(os.Getenv(aggregateAndDNSSupportEnv), "false")
-
-	// XDSRBAC indicates whether xDS configured RBAC HTTP Filter is enabled,
-	// which can be disabled by setting the environment variable
-	// "GRPC_XDS_EXPERIMENTAL_RBAC" to "false".
-	XDSRBAC = !strings.EqualFold(os.Getenv(rbacSupportEnv), "false")
-	// XDSOutlierDetection indicates whether outlier detection support is
-	// enabled, which can be disabled by setting the environment variable
-	// "GRPC_EXPERIMENTAL_ENABLE_OUTLIER_DETECTION" to "false".
-	XDSOutlierDetection = !strings.EqualFold(os.Getenv(outlierDetectionSupportEnv), "false")
-	// XDSFederation indicates whether federation support is enabled.
-	XDSFederation = strings.EqualFold(os.Getenv(federationEnv), "true")
-
-	// XDSRLS indicates whether processing of Cluster Specifier plugins and
-	// support for the RLS CLuster Specifier is enabled, which can be enabled by
-	// setting the environment variable "GRPC_EXPERIMENTAL_XDS_RLS_LB" to
-	// "true".
-	XDSRLS = strings.EqualFold(os.Getenv(rlsInXDSEnv), "true")
 
 	// C2PResolverTestOnlyTrafficDirectorURI is the TD URI for testing.
-	C2PResolverTestOnlyTrafficDirectorURI = os.Getenv(c2pResolverTestOnlyTrafficDirectorURIEnv)
+	C2PResolverTestOnlyTrafficDirectorURI = os.Getenv("GRPC_TEST_ONLY_GOOGLE_C2P_RESOLVER_TRAFFIC_DIRECTOR_URI")
 )

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

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2023 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
+
+var (
+	// WithRecvBufferPool is implemented by the grpc package and returns a dial
+	// option to configure a shared buffer pool for a grpc.ClientConn.
+	WithRecvBufferPool any // func (grpc.SharedBufferPool) grpc.DialOption
+
+	// RecvBufferPool is implemented by the grpc package and returns a server
+	// option to configure a shared buffer pool for a grpc.Server.
+	RecvBufferPool any // func (grpc.SharedBufferPool) grpc.ServerOption
+)

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

@@ -30,7 +30,7 @@ var Logger LoggerV2
 var DepthLogger DepthLoggerV2
 
 // InfoDepth logs to the INFO log at the specified depth.
-func InfoDepth(depth int, args ...interface{}) {
+func InfoDepth(depth int, args ...any) {
 	if DepthLogger != nil {
 		DepthLogger.InfoDepth(depth, args...)
 	} else {
@@ -39,7 +39,7 @@ func InfoDepth(depth int, args ...interface{}) {
 }
 
 // WarningDepth logs to the WARNING log at the specified depth.
-func WarningDepth(depth int, args ...interface{}) {
+func WarningDepth(depth int, args ...any) {
 	if DepthLogger != nil {
 		DepthLogger.WarningDepth(depth, args...)
 	} else {
@@ -48,7 +48,7 @@ func WarningDepth(depth int, args ...interface{}) {
 }
 
 // ErrorDepth logs to the ERROR log at the specified depth.
-func ErrorDepth(depth int, args ...interface{}) {
+func ErrorDepth(depth int, args ...any) {
 	if DepthLogger != nil {
 		DepthLogger.ErrorDepth(depth, args...)
 	} else {
@@ -57,7 +57,7 @@ func ErrorDepth(depth int, args ...interface{}) {
 }
 
 // FatalDepth logs to the FATAL log at the specified depth.
-func FatalDepth(depth int, args ...interface{}) {
+func FatalDepth(depth int, args ...any) {
 	if DepthLogger != nil {
 		DepthLogger.FatalDepth(depth, args...)
 	} else {
@@ -71,35 +71,35 @@ func FatalDepth(depth int, args ...interface{}) {
 // 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{})
+	Info(args ...any)
 	// Infoln logs to INFO log. Arguments are handled in the manner of fmt.Println.
-	Infoln(args ...interface{})
+	Infoln(args ...any)
 	// Infof logs to INFO log. Arguments are handled in the manner of fmt.Printf.
-	Infof(format string, args ...interface{})
+	Infof(format string, args ...any)
 	// Warning logs to WARNING log. Arguments are handled in the manner of fmt.Print.
-	Warning(args ...interface{})
+	Warning(args ...any)
 	// Warningln logs to WARNING log. Arguments are handled in the manner of fmt.Println.
-	Warningln(args ...interface{})
+	Warningln(args ...any)
 	// Warningf logs to WARNING log. Arguments are handled in the manner of fmt.Printf.
-	Warningf(format string, args ...interface{})
+	Warningf(format string, args ...any)
 	// Error logs to ERROR log. Arguments are handled in the manner of fmt.Print.
-	Error(args ...interface{})
+	Error(args ...any)
 	// Errorln logs to ERROR log. Arguments are handled in the manner of fmt.Println.
-	Errorln(args ...interface{})
+	Errorln(args ...any)
 	// Errorf logs to ERROR log. Arguments are handled in the manner of fmt.Printf.
-	Errorf(format string, args ...interface{})
+	Errorf(format string, args ...any)
 	// 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{})
+	Fatal(args ...any)
 	// 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{})
+	Fatalln(args ...any)
 	// 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{})
+	Fatalf(format string, args ...any)
 	// V reports whether verbosity level l is at least the requested verbose level.
 	V(l int) bool
 }
@@ -116,11 +116,11 @@ type LoggerV2 interface {
 // 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{})
+	InfoDepth(depth int, args ...any)
 	// WarningDepth logs to WARNING log at the specified depth. Arguments are handled in the manner of fmt.Println.
-	WarningDepth(depth int, args ...interface{})
+	WarningDepth(depth int, args ...any)
 	// ErrorDepth logs to ERROR log at the specified depth. Arguments are handled in the manner of fmt.Println.
-	ErrorDepth(depth int, args ...interface{})
+	ErrorDepth(depth int, args ...any)
 	// FatalDepth logs to FATAL log at the specified depth. Arguments are handled in the manner of fmt.Println.
-	FatalDepth(depth int, args ...interface{})
+	FatalDepth(depth int, args ...any)
 }

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

@@ -31,7 +31,7 @@ type PrefixLogger struct {
 }
 
 // Infof does info logging.
-func (pl *PrefixLogger) Infof(format string, args ...interface{}) {
+func (pl *PrefixLogger) Infof(format string, args ...any) {
 	if pl != nil {
 		// Handle nil, so the tests can pass in a nil logger.
 		format = pl.prefix + format
@@ -42,7 +42,7 @@ func (pl *PrefixLogger) Infof(format string, args ...interface{}) {
 }
 
 // Warningf does warning logging.
-func (pl *PrefixLogger) Warningf(format string, args ...interface{}) {
+func (pl *PrefixLogger) Warningf(format string, args ...any) {
 	if pl != nil {
 		format = pl.prefix + format
 		pl.logger.WarningDepth(1, fmt.Sprintf(format, args...))
@@ -52,7 +52,7 @@ func (pl *PrefixLogger) Warningf(format string, args ...interface{}) {
 }
 
 // Errorf does error logging.
-func (pl *PrefixLogger) Errorf(format string, args ...interface{}) {
+func (pl *PrefixLogger) Errorf(format string, args ...any) {
 	if pl != nil {
 		format = pl.prefix + format
 		pl.logger.ErrorDepth(1, fmt.Sprintf(format, args...))
@@ -62,7 +62,10 @@ func (pl *PrefixLogger) Errorf(format string, args ...interface{}) {
 }
 
 // Debugf does info logging at verbose level 2.
-func (pl *PrefixLogger) Debugf(format string, args ...interface{}) {
+func (pl *PrefixLogger) Debugf(format string, args ...any) {
+	// 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
 	}
@@ -73,6 +76,15 @@ func (pl *PrefixLogger) Debugf(format string, args ...interface{}) {
 		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.

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

@@ -72,3 +72,24 @@ func Uint64() uint64 {
 	defer mu.Unlock()
 	return r.Uint64()
 }
+
+// Uint32 implements rand.Uint32 on the grpcrand global source.
+func Uint32() uint32 {
+	mu.Lock()
+	defer mu.Unlock()
+	return r.Uint32()
+}
+
+// ExpFloat64 implements rand.ExpFloat64 on the grpcrand global source.
+func ExpFloat64() float64 {
+	mu.Lock()
+	defer mu.Unlock()
+	return r.ExpFloat64()
+}
+
+// Shuffle implements rand.Shuffle on the grpcrand global source.
+var Shuffle = func(n int, f func(int, int)) {
+	mu.Lock()
+	defer mu.Unlock()
+	r.Shuffle(n, f)
+}

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

@@ -0,0 +1,100 @@
+/*
+ *
+ * Copyright 2022 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 grpcsync
+
+import (
+	"context"
+
+	"google.golang.org/grpc/internal/buffer"
+)
+
+// CallbackSerializer provides a mechanism to schedule callbacks in a
+// synchronized manner. It provides a FIFO guarantee on the order of execution
+// of scheduled callbacks. New callbacks can be scheduled by invoking the
+// Schedule() method.
+//
+// This type is safe for concurrent access.
+type CallbackSerializer struct {
+	// done is closed once the serializer is shut down completely, i.e all
+	// scheduled callbacks are executed and the serializer has deallocated all
+	// its resources.
+	done chan struct{}
+
+	callbacks *buffer.Unbounded
+}
+
+// NewCallbackSerializer returns a new CallbackSerializer instance. The provided
+// context will be passed to the scheduled callbacks. Users should cancel the
+// provided context to shutdown the CallbackSerializer. It is guaranteed that no
+// callbacks will be added once this context is canceled, and any pending un-run
+// callbacks will be executed before the serializer is shut down.
+func NewCallbackSerializer(ctx context.Context) *CallbackSerializer {
+	cs := &CallbackSerializer{
+		done:      make(chan struct{}),
+		callbacks: buffer.NewUnbounded(),
+	}
+	go cs.run(ctx)
+	return cs
+}
+
+// Schedule adds a callback to be scheduled after existing callbacks are run.
+//
+// Callbacks are expected to honor the context when performing any blocking
+// operations, and should return early when the context is canceled.
+//
+// Return value indicates if the callback was successfully added to the list of
+// callbacks to be executed by the serializer. It is not possible to add
+// callbacks once the context passed to NewCallbackSerializer is cancelled.
+func (cs *CallbackSerializer) Schedule(f func(ctx context.Context)) bool {
+	return cs.callbacks.Put(f) == nil
+}
+
+func (cs *CallbackSerializer) run(ctx context.Context) {
+	defer close(cs.done)
+
+	// TODO: when Go 1.21 is the oldest supported version, this loop and Close
+	// can be replaced with:
+	//
+	// context.AfterFunc(ctx, cs.callbacks.Close)
+	for ctx.Err() == nil {
+		select {
+		case <-ctx.Done():
+			// Do nothing here. Next iteration of the for loop will not happen,
+			// since ctx.Err() would be non-nil.
+		case cb := <-cs.callbacks.Get():
+			cs.callbacks.Load()
+			cb.(func(context.Context))(ctx)
+		}
+	}
+
+	// Close the buffer to prevent new callbacks from being added.
+	cs.callbacks.Close()
+
+	// Run all pending callbacks.
+	for cb := range cs.callbacks.Get() {
+		cs.callbacks.Load()
+		cb.(func(context.Context))(ctx)
+	}
+}
+
+// Done returns a channel that is closed after the context passed to
+// NewCallbackSerializer is canceled and all callbacks have been executed.
+func (cs *CallbackSerializer) Done() <-chan struct{} {
+	return cs.done
+}

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

@@ -0,0 +1,121 @@
+/*
+ *
+ * Copyright 2023 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 grpcsync
+
+import (
+	"context"
+	"sync"
+)
+
+// Subscriber represents an entity that is subscribed to messages published on
+// a PubSub. It wraps the callback to be invoked by the PubSub when a new
+// message is published.
+type Subscriber interface {
+	// OnMessage is invoked when a new message is published. Implementations
+	// must not block in this method.
+	OnMessage(msg any)
+}
+
+// PubSub is a simple one-to-many publish-subscribe system that supports
+// messages of arbitrary type. It guarantees that messages are delivered in
+// the same order in which they were published.
+//
+// Publisher invokes the Publish() method to publish new messages, while
+// subscribers interested in receiving these messages register a callback
+// via the Subscribe() method.
+//
+// Once a PubSub is stopped, no more messages can be published, but any pending
+// published messages will be delivered to the subscribers.  Done may be used
+// to determine when all published messages have been delivered.
+type PubSub struct {
+	cs *CallbackSerializer
+
+	// Access to the below fields are guarded by this mutex.
+	mu          sync.Mutex
+	msg         any
+	subscribers map[Subscriber]bool
+}
+
+// NewPubSub returns a new PubSub instance.  Users should cancel the
+// provided context to shutdown the PubSub.
+func NewPubSub(ctx context.Context) *PubSub {
+	return &PubSub{
+		cs:          NewCallbackSerializer(ctx),
+		subscribers: map[Subscriber]bool{},
+	}
+}
+
+// Subscribe registers the provided Subscriber to the PubSub.
+//
+// If the PubSub contains a previously published message, the Subscriber's
+// OnMessage() callback will be invoked asynchronously with the existing
+// message to begin with, and subsequently for every newly published message.
+//
+// The caller is responsible for invoking the returned cancel function to
+// unsubscribe itself from the PubSub.
+func (ps *PubSub) Subscribe(sub Subscriber) (cancel func()) {
+	ps.mu.Lock()
+	defer ps.mu.Unlock()
+
+	ps.subscribers[sub] = true
+
+	if ps.msg != nil {
+		msg := ps.msg
+		ps.cs.Schedule(func(context.Context) {
+			ps.mu.Lock()
+			defer ps.mu.Unlock()
+			if !ps.subscribers[sub] {
+				return
+			}
+			sub.OnMessage(msg)
+		})
+	}
+
+	return func() {
+		ps.mu.Lock()
+		defer ps.mu.Unlock()
+		delete(ps.subscribers, sub)
+	}
+}
+
+// Publish publishes the provided message to the PubSub, and invokes
+// callbacks registered by subscribers asynchronously.
+func (ps *PubSub) Publish(msg any) {
+	ps.mu.Lock()
+	defer ps.mu.Unlock()
+
+	ps.msg = msg
+	for sub := range ps.subscribers {
+		s := sub
+		ps.cs.Schedule(func(context.Context) {
+			ps.mu.Lock()
+			defer ps.mu.Unlock()
+			if !ps.subscribers[s] {
+				return
+			}
+			s.OnMessage(msg)
+		})
+	}
+}
+
+// Done returns a channel that is closed after the context passed to NewPubSub
+// is canceled and all updates have been sent to subscribers.
+func (ps *PubSub) Done() <-chan struct{} {
+	return ps.cs.Done()
+}

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

@@ -0,0 +1,278 @@
+/*
+ *
+ * Copyright 2023 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 idle contains a component for managing idleness (entering and exiting)
+// based on RPC activity.
+package idle
+
+import (
+	"fmt"
+	"math"
+	"sync"
+	"sync/atomic"
+	"time"
+)
+
+// For overriding in unit tests.
+var timeAfterFunc = func(d time.Duration, f func()) *time.Timer {
+	return time.AfterFunc(d, f)
+}
+
+// Enforcer is the functionality provided by grpc.ClientConn to enter
+// and exit from idle mode.
+type Enforcer interface {
+	ExitIdleMode() error
+	EnterIdleMode()
+}
+
+// Manager implements idleness detection and calls the configured Enforcer to
+// enter/exit idle mode when appropriate.  Must be created by NewManager.
+type Manager struct {
+	// State accessed atomically.
+	lastCallEndTime           int64 // Unix timestamp in nanos; time when the most recent RPC completed.
+	activeCallsCount          int32 // Count of active RPCs; -math.MaxInt32 means channel is idle or is trying to get there.
+	activeSinceLastTimerCheck int32 // Boolean; True if there was an RPC since the last timer callback.
+	closed                    int32 // Boolean; True when the manager is closed.
+
+	// Can be accessed without atomics or mutex since these are set at creation
+	// time and read-only after that.
+	enforcer Enforcer // Functionality provided by grpc.ClientConn.
+	timeout  time.Duration
+
+	// idleMu is used to guarantee mutual exclusion in two scenarios:
+	// - Opposing intentions:
+	//   - a: Idle timeout has fired and handleIdleTimeout() is trying to put
+	//     the channel in idle mode because the channel has been inactive.
+	//   - b: At the same time an RPC is made on the channel, and OnCallBegin()
+	//     is trying to prevent the channel from going idle.
+	// - Competing intentions:
+	//   - The channel is in idle mode and there are multiple RPCs starting at
+	//     the same time, all trying to move the channel out of idle. Only one
+	//     of them should succeed in doing so, while the other RPCs should
+	//     piggyback on the first one and be successfully handled.
+	idleMu       sync.RWMutex
+	actuallyIdle bool
+	timer        *time.Timer
+}
+
+// NewManager creates a new idleness manager implementation for the
+// given idle timeout.  It begins in idle mode.
+func NewManager(enforcer Enforcer, timeout time.Duration) *Manager {
+	return &Manager{
+		enforcer:         enforcer,
+		timeout:          timeout,
+		actuallyIdle:     true,
+		activeCallsCount: -math.MaxInt32,
+	}
+}
+
+// resetIdleTimerLocked resets the idle timer to the given duration.  Called
+// when exiting idle mode or when the timer fires and we need to reset it.
+func (m *Manager) resetIdleTimerLocked(d time.Duration) {
+	if m.isClosed() || m.timeout == 0 || m.actuallyIdle {
+		return
+	}
+
+	// It is safe to ignore the return value from Reset() because this method is
+	// only ever called from the timer callback or when exiting idle mode.
+	if m.timer != nil {
+		m.timer.Stop()
+	}
+	m.timer = timeAfterFunc(d, m.handleIdleTimeout)
+}
+
+func (m *Manager) resetIdleTimer(d time.Duration) {
+	m.idleMu.Lock()
+	defer m.idleMu.Unlock()
+	m.resetIdleTimerLocked(d)
+}
+
+// handleIdleTimeout is the timer callback that is invoked upon expiry of the
+// configured idle timeout. The channel is considered inactive if there are no
+// ongoing calls and no RPC activity since the last time the timer fired.
+func (m *Manager) handleIdleTimeout() {
+	if m.isClosed() {
+		return
+	}
+
+	if atomic.LoadInt32(&m.activeCallsCount) > 0 {
+		m.resetIdleTimer(m.timeout)
+		return
+	}
+
+	// There has been activity on the channel since we last got here. Reset the
+	// timer and return.
+	if atomic.LoadInt32(&m.activeSinceLastTimerCheck) == 1 {
+		// Set the timer to fire after a duration of idle timeout, calculated
+		// from the time the most recent RPC completed.
+		atomic.StoreInt32(&m.activeSinceLastTimerCheck, 0)
+		m.resetIdleTimer(time.Duration(atomic.LoadInt64(&m.lastCallEndTime)-time.Now().UnixNano()) + m.timeout)
+		return
+	}
+
+	// Now that we've checked that there has been no activity, attempt to enter
+	// idle mode, which is very likely to succeed.
+	if m.tryEnterIdleMode() {
+		// Successfully entered idle mode. No timer needed until we exit idle.
+		return
+	}
+
+	// Failed to enter idle mode due to a concurrent RPC that kept the channel
+	// active, or because of an error from the channel. Undo the attempt to
+	// enter idle, and reset the timer to try again later.
+	m.resetIdleTimer(m.timeout)
+}
+
+// tryEnterIdleMode instructs the channel to enter idle mode. But before
+// that, it performs a last minute check to ensure that no new RPC has come in,
+// making the channel active.
+//
+// Return value indicates whether or not the channel moved to idle mode.
+//
+// Holds idleMu which ensures mutual exclusion with exitIdleMode.
+func (m *Manager) tryEnterIdleMode() bool {
+	// Setting the activeCallsCount to -math.MaxInt32 indicates to OnCallBegin()
+	// that the channel is either in idle mode or is trying to get there.
+	if !atomic.CompareAndSwapInt32(&m.activeCallsCount, 0, -math.MaxInt32) {
+		// This CAS operation can fail if an RPC started after we checked for
+		// activity in the timer handler, or one was ongoing from before the
+		// last time the timer fired, or if a test is attempting to enter idle
+		// mode without checking.  In all cases, abort going into idle mode.
+		return false
+	}
+	// N.B. if we fail to enter idle mode after this, we must re-add
+	// math.MaxInt32 to m.activeCallsCount.
+
+	m.idleMu.Lock()
+	defer m.idleMu.Unlock()
+
+	if atomic.LoadInt32(&m.activeCallsCount) != -math.MaxInt32 {
+		// We raced and lost to a new RPC. Very rare, but stop entering idle.
+		atomic.AddInt32(&m.activeCallsCount, math.MaxInt32)
+		return false
+	}
+	if atomic.LoadInt32(&m.activeSinceLastTimerCheck) == 1 {
+		// A very short RPC could have come in (and also finished) after we
+		// checked for calls count and activity in handleIdleTimeout(), but
+		// before the CAS operation. So, we need to check for activity again.
+		atomic.AddInt32(&m.activeCallsCount, math.MaxInt32)
+		return false
+	}
+
+	// No new RPCs have come in since we set the active calls count value to
+	// -math.MaxInt32. And since we have the lock, it is safe to enter idle mode
+	// unconditionally now.
+	m.enforcer.EnterIdleMode()
+	m.actuallyIdle = true
+	return true
+}
+
+func (m *Manager) EnterIdleModeForTesting() {
+	m.tryEnterIdleMode()
+}
+
+// OnCallBegin is invoked at the start of every RPC.
+func (m *Manager) OnCallBegin() error {
+	if m.isClosed() {
+		return nil
+	}
+
+	if atomic.AddInt32(&m.activeCallsCount, 1) > 0 {
+		// Channel is not idle now. Set the activity bit and allow the call.
+		atomic.StoreInt32(&m.activeSinceLastTimerCheck, 1)
+		return nil
+	}
+
+	// Channel is either in idle mode or is in the process of moving to idle
+	// mode. Attempt to exit idle mode to allow this RPC.
+	if err := m.ExitIdleMode(); err != nil {
+		// Undo the increment to calls count, and return an error causing the
+		// RPC to fail.
+		atomic.AddInt32(&m.activeCallsCount, -1)
+		return err
+	}
+
+	atomic.StoreInt32(&m.activeSinceLastTimerCheck, 1)
+	return nil
+}
+
+// ExitIdleMode instructs m to call the enforcer's ExitIdleMode and update m's
+// internal state.
+func (m *Manager) ExitIdleMode() error {
+	// Holds idleMu which ensures mutual exclusion with tryEnterIdleMode.
+	m.idleMu.Lock()
+	defer m.idleMu.Unlock()
+
+	if m.isClosed() || !m.actuallyIdle {
+		// This can happen in three scenarios:
+		// - handleIdleTimeout() set the calls count to -math.MaxInt32 and called
+		//   tryEnterIdleMode(). But before the latter could grab the lock, an RPC
+		//   came in and OnCallBegin() noticed that the calls count is negative.
+		// - Channel is in idle mode, and multiple new RPCs come in at the same
+		//   time, all of them notice a negative calls count in OnCallBegin and get
+		//   here. The first one to get the lock would got the channel to exit idle.
+		// - Channel is not in idle mode, and the user calls Connect which calls
+		//   m.ExitIdleMode.
+		//
+		// In any case, there is nothing to do here.
+		return nil
+	}
+
+	if err := m.enforcer.ExitIdleMode(); err != nil {
+		return fmt.Errorf("failed to exit idle mode: %w", err)
+	}
+
+	// Undo the idle entry process. This also respects any new RPC attempts.
+	atomic.AddInt32(&m.activeCallsCount, math.MaxInt32)
+	m.actuallyIdle = false
+
+	// Start a new timer to fire after the configured idle timeout.
+	m.resetIdleTimerLocked(m.timeout)
+	return nil
+}
+
+// OnCallEnd is invoked at the end of every RPC.
+func (m *Manager) OnCallEnd() {
+	if m.isClosed() {
+		return
+	}
+
+	// Record the time at which the most recent call finished.
+	atomic.StoreInt64(&m.lastCallEndTime, time.Now().UnixNano())
+
+	// Decrement the active calls count. This count can temporarily go negative
+	// when the timer callback is in the process of moving the channel to idle
+	// mode, but one or more RPCs come in and complete before the timer callback
+	// can get done with the process of moving to idle mode.
+	atomic.AddInt32(&m.activeCallsCount, -1)
+}
+
+func (m *Manager) isClosed() bool {
+	return atomic.LoadInt32(&m.closed) == 1
+}
+
+func (m *Manager) Close() {
+	atomic.StoreInt32(&m.closed, 1)
+
+	m.idleMu.Lock()
+	if m.timer != nil {
+		m.timer.Stop()
+		m.timer = nil
+	}
+	m.idleMu.Unlock()
+}

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

@@ -30,7 +30,7 @@ import (
 
 var (
 	// WithHealthCheckFunc is set by dialoptions.go
-	WithHealthCheckFunc interface{} // func (HealthChecker) DialOption
+	WithHealthCheckFunc any // 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.
@@ -38,8 +38,12 @@ var (
 	// 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
+	// KeepaliveMinServerPingTime is the minimum ping interval for servers.
+	// This must be 1s by default, but tests may wish to set it lower for
+	// convenience.
+	KeepaliveMinServerPingTime = time.Second
 	// ParseServiceConfig parses a JSON representation of the service config.
-	ParseServiceConfig interface{} // func(string) *serviceconfig.ParseResult
+	ParseServiceConfig any // 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
@@ -49,44 +53,86 @@ var (
 	// 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
+	GetCertificateProviderBuilder any // 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
+	GetXDSHandshakeInfoForTesting any // 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
+	GetServerCredentials any // 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 any // 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)
+	DrainServerTransports any // func(*grpc.Server, string)
+	// IsRegisteredMethod returns whether the passed in method is registered as
+	// a method on the server.
+	IsRegisteredMethod any // func(*grpc.Server, string) bool
+	// ServerFromContext returns the server from the context.
+	ServerFromContext any // func(context.Context) *grpc.Server
 	// 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.
-	AddGlobalServerOptions interface{} // func(opt ...ServerOption)
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	AddGlobalServerOptions any // 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.
-	AddGlobalDialOptions interface{} // func(opt ...DialOption)
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	AddGlobalDialOptions any // 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 any // 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 any // 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
+	JoinServerOptions any // func(...grpc.ServerOption) grpc.ServerOption
 
 	// WithBinaryLogger returns a DialOption that specifies the binary logger
 	// for a ClientConn.
-	WithBinaryLogger interface{} // func(binarylog.Logger) grpc.DialOption
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	WithBinaryLogger any // func(binarylog.Logger) grpc.DialOption
 	// BinaryLogger returns a ServerOption that can set the binary logger for a
 	// server.
-	BinaryLogger interface{} // func(binarylog.Logger) grpc.ServerOption
+	//
+	// This is used in the 1.0 release of gcp/observability, and thus must not be
+	// deleted or changed.
+	BinaryLogger any // func(binarylog.Logger) grpc.ServerOption
+
+	// SubscribeToConnectivityStateChanges adds a grpcsync.Subscriber to a provided grpc.ClientConn
+	SubscribeToConnectivityStateChanges any // func(*grpc.ClientConn, grpcsync.Subscriber)
 
 	// NewXDSResolverWithConfigForTesting creates a new xds resolver builder using
 	// the provided xds bootstrap config instead of the global configuration from
@@ -97,7 +143,7 @@ var (
 	//
 	// 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)
+	NewXDSResolverWithConfigForTesting any // func([]byte) (resolver.Builder, error)
 
 	// RegisterRLSClusterSpecifierPluginForTesting registers the RLS Cluster
 	// Specifier Plugin for testing purposes, regardless of the XDSRLS environment
@@ -127,6 +173,21 @@ var (
 	//
 	// TODO: Remove this function once the RBAC env var is removed.
 	UnregisterRBACHTTPFilterForTesting func()
+
+	// ORCAAllowAnyMinReportingInterval is for examples/orca use ONLY.
+	ORCAAllowAnyMinReportingInterval any // func(so *orca.ServiceOptions)
+
+	// GRPCResolverSchemeExtraMetadata determines when gRPC will add extra
+	// metadata to RPCs.
+	GRPCResolverSchemeExtraMetadata string = "xds"
+
+	// EnterIdleModeForTesting gets the ClientConn to enter IDLE mode.
+	EnterIdleModeForTesting any // func(*grpc.ClientConn)
+
+	// ExitIdleModeForTesting gets the ClientConn to exit IDLE mode.
+	ExitIdleModeForTesting any // func(*grpc.ClientConn) error
+
+	ChannelzTurnOffForTesting func()
 )
 
 // HealthChecker defines the signature of the client-side LB channel health checking function.
@@ -137,7 +198,7 @@ var (
 //
 // 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
+type HealthChecker func(ctx context.Context, newStream func(string) (any, error), setConnectivityState func(connectivity.State, error), serviceName string) error
 
 const (
 	// CredsBundleModeFallback switches GoogleDefaultCreds to fallback mode.

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

@@ -35,7 +35,7 @@ const mdKey = mdKeyType("grpc.internal.address.metadata")
 
 type mdValue metadata.MD
 
-func (m mdValue) Equal(o interface{}) bool {
+func (m mdValue) Equal(o any) bool {
 	om, ok := o.(mdValue)
 	if !ok {
 		return false
@@ -76,33 +76,11 @@ func Set(addr resolver.Address, md metadata.MD) resolver.Address {
 	return addr
 }
 
-// Validate returns an error if the input md contains invalid keys or values.
-//
-// If the header is not a pseudo-header, the following items are checked:
-// - header names must contain one or more characters from this set [0-9 a-z _ - .].
-// - if the header-name ends with a "-bin" suffix, no validation of the header value is performed.
-// - otherwise, the header value must contain one or more characters from the set [%x20-%x7E].
+// Validate validates every pair in md with ValidatePair.
 func Validate(md metadata.MD) error {
 	for k, vals := range md {
-		// pseudo-header will be ignored
-		if k[0] == ':' {
-			continue
-		}
-		// check key, for i that saving a conversion if not using for range
-		for i := 0; i < len(k); i++ {
-			r := k[i]
-			if !(r >= 'a' && r <= 'z') && !(r >= '0' && r <= '9') && r != '.' && r != '-' && r != '_' {
-				return fmt.Errorf("header key %q contains illegal characters not in [0-9a-z-_.]", k)
-			}
-		}
-		if strings.HasSuffix(k, "-bin") {
-			continue
-		}
-		// check value
-		for _, val := range vals {
-			if hasNotPrintable(val) {
-				return fmt.Errorf("header key %q contains value with non-printable ASCII characters", k)
-			}
+		if err := ValidatePair(k, vals...); err != nil {
+			return err
 		}
 	}
 	return nil
@@ -118,3 +96,37 @@ func hasNotPrintable(msg string) bool {
 	}
 	return false
 }
+
+// ValidatePair validate a key-value pair with the following rules (the pseudo-header will be skipped) :
+//
+// - key must contain one or more characters.
+// - the characters in the key must be contained in [0-9 a-z _ - .].
+// - if the key ends with a "-bin" suffix, no validation of the corresponding value is performed.
+// - the characters in the every value must be printable (in [%x20-%x7E]).
+func ValidatePair(key string, vals ...string) error {
+	// key should not be empty
+	if key == "" {
+		return fmt.Errorf("there is an empty key in the header")
+	}
+	// pseudo-header will be ignored
+	if key[0] == ':' {
+		return nil
+	}
+	// check key, for i that saving a conversion if not using for range
+	for i := 0; i < len(key); i++ {
+		r := key[i]
+		if !(r >= 'a' && r <= 'z') && !(r >= '0' && r <= '9') && r != '.' && r != '-' && r != '_' {
+			return fmt.Errorf("header key %q contains illegal characters not in [0-9a-z-_.]", key)
+		}
+	}
+	if strings.HasSuffix(key, "-bin") {
+		return nil
+	}
+	// check value
+	for _, val := range vals {
+		if hasNotPrintable(val) {
+			return fmt.Errorf("header key %q contains value with non-printable ASCII characters", key)
+		}
+	}
+	return nil
+}

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

@@ -35,7 +35,7 @@ const jsonIndent = "  "
 // ToJSON marshals the input into a json string.
 //
 // If marshal fails, it falls back to fmt.Sprintf("%+v").
-func ToJSON(e interface{}) string {
+func ToJSON(e any) string {
 	switch ee := e.(type) {
 	case protov1.Message:
 		mm := jsonpb.Marshaler{Indent: jsonIndent}

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

@@ -92,7 +92,7 @@ type ClientStream interface {
 	// calling RecvMsg on the same stream at the same time, but it is not safe
 	// to call SendMsg on the same stream in different goroutines. It is also
 	// not safe to call CloseSend concurrently with SendMsg.
-	SendMsg(m interface{}) error
+	SendMsg(m any) error
 	// RecvMsg blocks until it receives a message into m or the stream is
 	// done. It returns io.EOF when the stream completes successfully. On
 	// any other error, the stream is aborted and the error contains the RPC
@@ -101,7 +101,7 @@ type ClientStream interface {
 	// It is safe to have a goroutine calling SendMsg and another goroutine
 	// calling RecvMsg on the same stream at the same time, but it is not
 	// safe to call RecvMsg on the same stream in different goroutines.
-	RecvMsg(m interface{}) error
+	RecvMsg(m any) error
 }
 
 // ClientInterceptor is an interceptor for gRPC client streams.

vendor/google.golang.org/grpc/internal/resolver/dns/dns_resolver.go

@@ -23,7 +23,6 @@ package dns
 import (
 	"context"
 	"encoding/json"
-	"errors"
 	"fmt"
 	"net"
 	"os"
@@ -37,6 +36,7 @@ import (
 	"google.golang.org/grpc/internal/backoff"
 	"google.golang.org/grpc/internal/envconfig"
 	"google.golang.org/grpc/internal/grpcrand"
+	"google.golang.org/grpc/internal/resolver/dns/internal"
 	"google.golang.org/grpc/resolver"
 	"google.golang.org/grpc/serviceconfig"
 )
@@ -47,53 +47,37 @@ var EnableSRVLookups = false
 
 var logger = grpclog.Component("dns")
 
-// Globals to stub out in tests. TODO: Perhaps these two can be combined into a
-// single variable for testing the resolver?
-var (
-	newTimer           = time.NewTimer
-	newTimerDNSResRate = time.NewTimer
-)
-
 func init() {
 	resolver.Register(NewBuilder())
+	internal.TimeAfterFunc = time.After
+	internal.NewNetResolver = newNetResolver
+	internal.AddressDialer = addressDialer
 }
 
 const (
 	defaultPort       = "443"
 	defaultDNSSvrPort = "53"
 	golang            = "GO"
-	// txtPrefix is the prefix string to be prepended to the host name for txt record lookup.
+	// txtPrefix is the prefix string to be prepended to the host name for txt
+	// record lookup.
 	txtPrefix = "_grpc_config."
 	// In DNS, service config is encoded in a TXT record via the mechanism
 	// described in RFC-1464 using the attribute name grpc_config.
 	txtAttribute = "grpc_config="
 )
 
-var (
-	errMissingAddr = errors.New("dns resolver: missing address")
-
-	// Addresses ending with a colon that is supposed to be the separator
-	// between host and port is not allowed.  E.g. "::" is a valid address as
-	// it is an IPv6 address (host only) and "[::]:" is invalid as it ends with
-	// a colon as the host and port separator
-	errEndsWithColon = errors.New("dns resolver: missing port after port-separator colon")
-)
-
-var (
-	defaultResolver netResolver = net.DefaultResolver
-	// To prevent excessive re-resolution, we enforce a rate limit on DNS
-	// resolution requests.
-	minDNSResRate = 30 * time.Second
-)
-
-var customAuthorityDialler = func(authority string) func(ctx context.Context, network, address string) (net.Conn, error) {
-	return func(ctx context.Context, network, address string) (net.Conn, error) {
+var addressDialer = func(address string) func(context.Context, string, string) (net.Conn, error) {
+	return func(ctx context.Context, network, _ string) (net.Conn, error) {
 		var dialer net.Dialer
-		return dialer.DialContext(ctx, network, authority)
+		return dialer.DialContext(ctx, network, address)
 	}
 }
 
-var customAuthorityResolver = func(authority string) (netResolver, error) {
+var newNetResolver = func(authority string) (internal.NetResolver, error) {
+	if authority == "" {
+		return net.DefaultResolver, nil
+	}
+
 	host, port, err := parseTarget(authority, defaultDNSSvrPort)
 	if err != nil {
 		return nil, err
@@ -103,7 +87,7 @@ var customAuthorityResolver = func(authority string) (netResolver, error) {
 
 	return &net.Resolver{
 		PreferGo: true,
-		Dial:     customAuthorityDialler(authorityWithPort),
+		Dial:     internal.AddressDialer(authorityWithPort),
 	}, nil
 }
 
@@ -114,9 +98,10 @@ func NewBuilder() resolver.Builder {
 
 type dnsBuilder struct{}
 
-// Build creates and starts a DNS resolver that watches the name resolution of the target.
+// Build creates and starts a DNS resolver that watches the name resolution of
+// the target.
 func (b *dnsBuilder) Build(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOptions) (resolver.Resolver, error) {
-	host, port, err := parseTarget(target.Endpoint, defaultPort)
+	host, port, err := parseTarget(target.Endpoint(), defaultPort)
 	if err != nil {
 		return nil, err
 	}
@@ -140,13 +125,9 @@ func (b *dnsBuilder) Build(target resolver.Target, cc resolver.ClientConn, opts
 		disableServiceConfig: opts.DisableServiceConfig,
 	}
 
-	if target.Authority == "" {
-		d.resolver = defaultResolver
-	} else {
-		d.resolver, err = customAuthorityResolver(target.Authority)
-		if err != nil {
-			return nil, err
-		}
+	d.resolver, err = internal.NewNetResolver(target.URL.Host)
+	if err != nil {
+		return nil, err
 	}
 
 	d.wg.Add(1)
@@ -159,12 +140,6 @@ func (b *dnsBuilder) Scheme() string {
 	return "dns"
 }
 
-type netResolver interface {
-	LookupHost(ctx context.Context, host string) (addrs []string, err error)
-	LookupSRV(ctx context.Context, service, proto, name string) (cname string, addrs []*net.SRV, err error)
-	LookupTXT(ctx context.Context, name string) (txts []string, err error)
-}
-
 // deadResolver is a resolver that does nothing.
 type deadResolver struct{}
 
@@ -176,23 +151,26 @@ func (deadResolver) Close() {}
 type dnsResolver struct {
 	host     string
 	port     string
-	resolver netResolver
+	resolver internal.NetResolver
 	ctx      context.Context
 	cancel   context.CancelFunc
 	cc       resolver.ClientConn
-	// rn channel is used by ResolveNow() to force an immediate resolution of the target.
+	// rn channel is used by ResolveNow() to force an immediate resolution of the
+	// target.
 	rn chan struct{}
-	// wg is used to enforce Close() to return after the watcher() goroutine has finished.
-	// Otherwise, data race will be possible. [Race Example] in dns_resolver_test we
-	// replace the real lookup functions with mocked ones to facilitate testing.
-	// If Close() doesn't wait for watcher() goroutine finishes, race detector sometimes
-	// will warns lookup (READ the lookup function pointers) inside watcher() goroutine
-	// has data race with replaceNetFunc (WRITE the lookup function pointers).
+	// wg is used to enforce Close() to return after the watcher() goroutine has
+	// finished. Otherwise, data race will be possible. [Race Example] in
+	// dns_resolver_test we replace the real lookup functions with mocked ones to
+	// facilitate testing. If Close() doesn't wait for watcher() goroutine
+	// finishes, race detector sometimes will warns lookup (READ the lookup
+	// function pointers) inside watcher() goroutine has data race with
+	// replaceNetFunc (WRITE the lookup function pointers).
 	wg                   sync.WaitGroup
 	disableServiceConfig bool
 }
 
-// ResolveNow invoke an immediate resolution of the target that this dnsResolver watches.
+// ResolveNow invoke an immediate resolution of the target that this
+// dnsResolver watches.
 func (d *dnsResolver) ResolveNow(resolver.ResolveNowOptions) {
 	select {
 	case d.rn <- struct{}{}:
@@ -218,28 +196,27 @@ func (d *dnsResolver) watcher() {
 			err = d.cc.UpdateState(*state)
 		}
 
-		var timer *time.Timer
+		var waitTime time.Duration
 		if err == nil {
-			// Success resolving, wait for the next ResolveNow. However, also wait 30 seconds at the very least
-			// to prevent constantly re-resolving.
+			// Success resolving, wait for the next ResolveNow. However, also wait 30
+			// seconds at the very least to prevent constantly re-resolving.
 			backoffIndex = 1
-			timer = newTimerDNSResRate(minDNSResRate)
+			waitTime = internal.MinResolutionRate
 			select {
 			case <-d.ctx.Done():
-				timer.Stop()
 				return
 			case <-d.rn:
 			}
 		} else {
-			// Poll on an error found in DNS Resolver or an error received from ClientConn.
-			timer = newTimer(backoff.DefaultExponential.Backoff(backoffIndex))
+			// Poll on an error found in DNS Resolver or an error received from
+			// ClientConn.
+			waitTime = backoff.DefaultExponential.Backoff(backoffIndex)
 			backoffIndex++
 		}
 		select {
 		case <-d.ctx.Done():
-			timer.Stop()
 			return
-		case <-timer.C:
+		case <-internal.TimeAfterFunc(waitTime):
 		}
 	}
 }
@@ -278,7 +255,8 @@ func (d *dnsResolver) lookupSRV() ([]resolver.Address, error) {
 }
 
 func handleDNSError(err error, lookupType string) error {
-	if dnsErr, ok := err.(*net.DNSError); ok && !dnsErr.IsTimeout && !dnsErr.IsTemporary {
+	dnsErr, ok := err.(*net.DNSError)
+	if ok && !dnsErr.IsTimeout && !dnsErr.IsTemporary {
 		// Timeouts and temporary errors should be communicated to gRPC to
 		// attempt another DNS query (with backoff).  Other errors should be
 		// suppressed (they may represent the absence of a TXT record).
@@ -307,10 +285,12 @@ func (d *dnsResolver) lookupTXT() *serviceconfig.ParseResult {
 		res += s
 	}
 
-	// TXT record must have "grpc_config=" attribute in order to be used as service config.
+	// TXT record must have "grpc_config=" attribute in order to be used as
+	// service config.
 	if !strings.HasPrefix(res, txtAttribute) {
 		logger.Warningf("dns: TXT record %v missing %v attribute", res, txtAttribute)
-		// This is not an error; it is the equivalent of not having a service config.
+		// This is not an error; it is the equivalent of not having a service
+		// config.
 		return nil
 	}
 	sc := canaryingSC(strings.TrimPrefix(res, txtAttribute))
@@ -352,9 +332,10 @@ func (d *dnsResolver) lookup() (*resolver.State, error) {
 	return &state, nil
 }
 
-// formatIP returns ok = false if addr is not a valid textual representation of an IP address.
-// If addr is an IPv4 address, return the addr and ok = true.
-// If addr is an IPv6 address, return the addr enclosed in square brackets and ok = true.
+// formatIP returns ok = false if addr is not a valid textual representation of
+// an IP address. If addr is an IPv4 address, return the addr and ok = true.
+// If addr is an IPv6 address, return the addr enclosed in square brackets and
+// ok = true.
 func formatIP(addr string) (addrIP string, ok bool) {
 	ip := net.ParseIP(addr)
 	if ip == nil {
@@ -366,10 +347,10 @@ func formatIP(addr string) (addrIP string, ok bool) {
 	return "[" + addr + "]", true
 }
 
-// parseTarget takes the user input target string and default port, returns formatted host and port info.
-// If target doesn't specify a port, set the port to be the defaultPort.
-// If target is in IPv6 format and host-name is enclosed in square brackets, brackets
-// are stripped when setting the host.
+// parseTarget takes the user input target string and default port, returns
+// formatted host and port info. If target doesn't specify a port, set the port
+// to be the defaultPort. If target is in IPv6 format and host-name is enclosed
+// in square brackets, brackets are stripped when setting the host.
 // examples:
 // target: "www.google.com" defaultPort: "443" returns host: "www.google.com", port: "443"
 // target: "ipv4-host:80" defaultPort: "443" returns host: "ipv4-host", port: "80"
@@ -377,7 +358,7 @@ func formatIP(addr string) (addrIP string, ok bool) {
 // target: ":80" defaultPort: "443" returns host: "localhost", port: "80"
 func parseTarget(target, defaultPort string) (host, port string, err error) {
 	if target == "" {
-		return "", "", errMissingAddr
+		return "", "", internal.ErrMissingAddr
 	}
 	if ip := net.ParseIP(target); ip != nil {
 		// target is an IPv4 or IPv6(without brackets) address
@@ -385,12 +366,14 @@ func parseTarget(target, defaultPort string) (host, port string, err error) {
 	}
 	if host, port, err = net.SplitHostPort(target); err == nil {
 		if port == "" {
-			// If the port field is empty (target ends with colon), e.g. "[::1]:", this is an error.
-			return "", "", errEndsWithColon
+			// If the port field is empty (target ends with colon), e.g. "[::1]:",
+			// this is an error.
+			return "", "", internal.ErrEndsWithColon
 		}
 		// target has port, i.e ipv4-host:port, [ipv6-host]:port, host-name:port
 		if host == "" {
-			// Keep consistent with net.Dial(): If the host is empty, as in ":80", the local system is assumed.
+			// Keep consistent with net.Dial(): If the host is empty, as in ":80",
+			// the local system is assumed.
 			host = "localhost"
 		}
 		return host, port, nil

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

@@ -0,0 +1,70 @@
+/*
+ *
+ * Copyright 2023 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 functionality internal to the dns resolver package.
+package internal
+
+import (
+	"context"
+	"errors"
+	"net"
+	"time"
+)
+
+// NetResolver groups the methods on net.Resolver that are used by the DNS
+// resolver implementation. This allows the default net.Resolver instance to be
+// overidden from tests.
+type NetResolver interface {
+	LookupHost(ctx context.Context, host string) (addrs []string, err error)
+	LookupSRV(ctx context.Context, service, proto, name string) (cname string, addrs []*net.SRV, err error)
+	LookupTXT(ctx context.Context, name string) (txts []string, err error)
+}
+
+var (
+	// ErrMissingAddr is the error returned when building a DNS resolver when
+	// the provided target name is empty.
+	ErrMissingAddr = errors.New("dns resolver: missing address")
+
+	// ErrEndsWithColon is the error returned when building a DNS resolver when
+	// the provided target name ends with a colon that is supposed to be the
+	// separator between host and port.  E.g. "::" is a valid address as it is
+	// an IPv6 address (host only) and "[::]:" is invalid as it ends with a
+	// colon as the host and port separator
+	ErrEndsWithColon = errors.New("dns resolver: missing port after port-separator colon")
+)
+
+// The following vars are overridden from tests.
+var (
+	// MinResolutionRate is the minimum rate at which re-resolutions are
+	// allowed. This helps to prevent excessive re-resolution.
+	MinResolutionRate = 30 * time.Second
+
+	// TimeAfterFunc is used by the DNS resolver to wait for the given duration
+	// to elapse. In non-test code, this is implemented by time.After.  In test
+	// code, this can be used to control the amount of time the resolver is
+	// blocked waiting for the duration to elapse.
+	TimeAfterFunc func(time.Duration) <-chan time.Time
+
+	// NewNetResolver returns the net.Resolver instance for the given target.
+	NewNetResolver func(string) (NetResolver, error)
+
+	// AddressDialer is the dialer used to dial the DNS server. It accepts the
+	// Host portion of the URL corresponding to the user's dial target and
+	// returns a dial function.
+	AddressDialer func(address string) func(context.Context, string, string) (net.Conn, error)
+)

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

@@ -20,13 +20,20 @@
 // name without scheme back to gRPC as resolved address.
 package passthrough
 
-import "google.golang.org/grpc/resolver"
+import (
+	"errors"
+
+	"google.golang.org/grpc/resolver"
+)
 
 const scheme = "passthrough"
 
 type passthroughBuilder struct{}
 
 func (*passthroughBuilder) Build(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOptions) (resolver.Resolver, error) {
+	if target.Endpoint() == "" && opts.Dialer == nil {
+		return nil, errors.New("passthrough: received empty target in Build()")
+	}
 	r := &passthroughResolver{
 		target: target,
 		cc:     cc,
@@ -45,7 +52,7 @@ type passthroughResolver struct {
 }
 
 func (r *passthroughResolver) start() {
-	r.cc.UpdateState(resolver.State{Addresses: []resolver.Address{{Addr: r.target.Endpoint}}})
+	r.cc.UpdateState(resolver.State{Addresses: []resolver.Address{{Addr: r.target.Endpoint()}}})
 }
 
 func (*passthroughResolver) ResolveNow(o resolver.ResolveNowOptions) {}

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

@@ -34,8 +34,8 @@ type builder struct {
 }
 
 func (b *builder) Build(target resolver.Target, cc resolver.ClientConn, _ resolver.BuildOptions) (resolver.Resolver, error) {
-	if target.Authority != "" {
-		return nil, fmt.Errorf("invalid (non-empty) authority: %v", target.Authority)
+	if target.URL.Host != "" {
+		return nil, fmt.Errorf("invalid (non-empty) authority: %v", target.URL.Host)
 	}
 
 	// gRPC was parsing the dial target manually before PR #4817, and we

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

@@ -0,0 +1,130 @@
+/*
+ *
+ * Copyright 2023 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 serviceconfig
+
+import (
+	"encoding/json"
+	"fmt"
+	"math"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// Duration defines JSON marshal and unmarshal methods to conform to the
+// protobuf JSON spec defined [here].
+//
+// [here]: https://protobuf.dev/reference/protobuf/google.protobuf/#duration
+type Duration time.Duration
+
+func (d Duration) String() string {
+	return fmt.Sprint(time.Duration(d))
+}
+
+// MarshalJSON converts from d to a JSON string output.
+func (d Duration) MarshalJSON() ([]byte, error) {
+	ns := time.Duration(d).Nanoseconds()
+	sec := ns / int64(time.Second)
+	ns = ns % int64(time.Second)
+
+	var sign string
+	if sec < 0 || ns < 0 {
+		sign, sec, ns = "-", -1*sec, -1*ns
+	}
+
+	// Generated output always contains 0, 3, 6, or 9 fractional digits,
+	// depending on required precision.
+	str := fmt.Sprintf("%s%d.%09d", sign, sec, ns)
+	str = strings.TrimSuffix(str, "000")
+	str = strings.TrimSuffix(str, "000")
+	str = strings.TrimSuffix(str, ".000")
+	return []byte(fmt.Sprintf("\"%ss\"", str)), nil
+}
+
+// UnmarshalJSON unmarshals b as a duration JSON string into d.
+func (d *Duration) UnmarshalJSON(b []byte) error {
+	var s string
+	if err := json.Unmarshal(b, &s); err != nil {
+		return err
+	}
+	if !strings.HasSuffix(s, "s") {
+		return fmt.Errorf("malformed duration %q: missing seconds unit", s)
+	}
+	neg := false
+	if s[0] == '-' {
+		neg = true
+		s = s[1:]
+	}
+	ss := strings.SplitN(s[:len(s)-1], ".", 3)
+	if len(ss) > 2 {
+		return fmt.Errorf("malformed duration %q: too many decimals", s)
+	}
+	// hasDigits is set if either the whole or fractional part of the number is
+	// present, since both are optional but one is required.
+	hasDigits := false
+	var sec, ns int64
+	if len(ss[0]) > 0 {
+		var err error
+		if sec, err = strconv.ParseInt(ss[0], 10, 64); err != nil {
+			return fmt.Errorf("malformed duration %q: %v", s, err)
+		}
+		// Maximum seconds value per the durationpb spec.
+		const maxProtoSeconds = 315_576_000_000
+		if sec > maxProtoSeconds {
+			return fmt.Errorf("out of range: %q", s)
+		}
+		hasDigits = true
+	}
+	if len(ss) == 2 && len(ss[1]) > 0 {
+		if len(ss[1]) > 9 {
+			return fmt.Errorf("malformed duration %q: too many digits after decimal", s)
+		}
+		var err error
+		if ns, err = strconv.ParseInt(ss[1], 10, 64); err != nil {
+			return fmt.Errorf("malformed duration %q: %v", s, err)
+		}
+		for i := 9; i > len(ss[1]); i-- {
+			ns *= 10
+		}
+		hasDigits = true
+	}
+	if !hasDigits {
+		return fmt.Errorf("malformed duration %q: contains no numbers", s)
+	}
+
+	if neg {
+		sec *= -1
+		ns *= -1
+	}
+
+	// Maximum/minimum seconds/nanoseconds representable by Go's time.Duration.
+	const maxSeconds = math.MaxInt64 / int64(time.Second)
+	const maxNanosAtMaxSeconds = math.MaxInt64 % int64(time.Second)
+	const minSeconds = math.MinInt64 / int64(time.Second)
+	const minNanosAtMinSeconds = math.MinInt64 % int64(time.Second)
+
+	if sec > maxSeconds || (sec == maxSeconds && ns >= maxNanosAtMaxSeconds) {
+		*d = Duration(math.MaxInt64)
+	} else if sec < minSeconds || (sec == minSeconds && ns <= minNanosAtMinSeconds) {
+		*d = Duration(math.MinInt64)
+	} else {
+		*d = Duration(sec*int64(time.Second) + ns)
+	}
+	return nil
+}

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

@@ -43,13 +43,41 @@ type Status struct {
 	s *spb.Status
 }
 
+// NewWithProto returns a new status including details from statusProto.  This
+// is meant to be used by the gRPC library only.
+func NewWithProto(code codes.Code, message string, statusProto []string) *Status {
+	if len(statusProto) != 1 {
+		// No grpc-status-details bin header, or multiple; just ignore.
+		return &Status{s: &spb.Status{Code: int32(code), Message: message}}
+	}
+	st := &spb.Status{}
+	if err := proto.Unmarshal([]byte(statusProto[0]), st); err != nil {
+		// Probably not a google.rpc.Status proto; do not provide details.
+		return &Status{s: &spb.Status{Code: int32(code), Message: message}}
+	}
+	if st.Code == int32(code) {
+		// The codes match between the grpc-status header and the
+		// grpc-status-details-bin header; use the full details proto.
+		return &Status{s: st}
+	}
+	return &Status{
+		s: &spb.Status{
+			Code: int32(codes.Internal),
+			Message: fmt.Sprintf(
+				"grpc-status-details-bin mismatch: grpc-status=%v, grpc-message=%q, grpc-status-details-bin=%+v",
+				code, message, st,
+			),
+		},
+	}
+}
+
 // New returns a Status representing c and msg.
 func New(c codes.Code, msg string) *Status {
 	return &Status{s: &spb.Status{Code: int32(c), Message: msg}}
 }
 
 // Newf returns New(c, fmt.Sprintf(format, a...)).
-func Newf(c codes.Code, format string, a ...interface{}) *Status {
+func Newf(c codes.Code, format string, a ...any) *Status {
 	return New(c, fmt.Sprintf(format, a...))
 }
 
@@ -64,7 +92,7 @@ func Err(c codes.Code, msg string) error {
 }
 
 // Errorf returns Error(c, fmt.Sprintf(format, a...)).
-func Errorf(c codes.Code, format string, a ...interface{}) error {
+func Errorf(c codes.Code, format string, a ...any) error {
 	return Err(c, fmt.Sprintf(format, a...))
 }
 
@@ -120,11 +148,11 @@ func (s *Status) WithDetails(details ...proto.Message) (*Status, error) {
 
 // Details returns a slice of details messages attached to the status.
 // If a detail cannot be decoded, the error is returned in place of the detail.
-func (s *Status) Details() []interface{} {
+func (s *Status) Details() []any {
 	if s == nil || s.s == nil {
 		return nil
 	}
-	details := make([]interface{}, 0, len(s.s.Details))
+	details := make([]any, 0, len(s.s.Details))
 	for _, any := range s.s.Details {
 		detail := &ptypes.DynamicAny{}
 		if err := ptypes.UnmarshalAny(any, detail); err != nil {

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

@@ -0,0 +1,29 @@
+//go:build !unix
+
+/*
+ * Copyright 2023 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 (
+	"net"
+)
+
+// NetDialerWithTCPKeepalive returns a vanilla net.Dialer on non-unix platforms.
+func NetDialerWithTCPKeepalive() *net.Dialer {
+	return &net.Dialer{}
+}

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

@@ -0,0 +1,54 @@
+//go:build unix
+
+/*
+ * Copyright 2023 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 (
+	"net"
+	"syscall"
+	"time"
+
+	"golang.org/x/sys/unix"
+)
+
+// NetDialerWithTCPKeepalive returns a net.Dialer that enables TCP keepalives on
+// the underlying connection with OS default values for keepalive parameters.
+//
+// TODO: Once https://github.com/golang/go/issues/62254 lands, and the
+// appropriate Go version becomes less than our least supported Go version, we
+// should look into using the new API to make things more straightforward.
+func NetDialerWithTCPKeepalive() *net.Dialer {
+	return &net.Dialer{
+		// Setting a negative value here prevents the Go stdlib from overriding
+		// the values of TCP keepalive time and interval. It also prevents the
+		// Go stdlib from enabling TCP keepalives by default.
+		KeepAlive: time.Duration(-1),
+		// This method is called after the underlying network socket is created,
+		// but before dialing the socket (or calling its connect() method). The
+		// combination of unconditionally enabling TCP keepalives here, and
+		// disabling the overriding of TCP keepalive parameters by setting the
+		// KeepAlive field to a negative value above, results in OS defaults for
+		// the TCP keealive interval and time parameters.
+		Control: func(_, _ string, c syscall.RawConn) error {
+			return c.Control(func(fd uintptr) {
+				unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_KEEPALIVE, 1)
+			})
+		},
+	}
+}

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

@@ -22,6 +22,7 @@ import (
 	"bytes"
 	"errors"
 	"fmt"
+	"net"
 	"runtime"
 	"strconv"
 	"sync"
@@ -29,6 +30,7 @@ import (
 
 	"golang.org/x/net/http2"
 	"golang.org/x/net/http2/hpack"
+	"google.golang.org/grpc/internal/grpclog"
 	"google.golang.org/grpc/internal/grpcutil"
 	"google.golang.org/grpc/status"
 )
@@ -38,7 +40,7 @@ var updateHeaderTblSize = func(e *hpack.Encoder, v uint32) {
 }
 
 type itemNode struct {
-	it   interface{}
+	it   any
 	next *itemNode
 }
 
@@ -47,7 +49,7 @@ type itemList struct {
 	tail *itemNode
 }
 
-func (il *itemList) enqueue(i interface{}) {
+func (il *itemList) enqueue(i any) {
 	n := &itemNode{it: i}
 	if il.tail == nil {
 		il.head, il.tail = n, n
@@ -59,11 +61,11 @@ func (il *itemList) enqueue(i interface{}) {
 
 // peek returns the first item in the list without removing it from the
 // list.
-func (il *itemList) peek() interface{} {
+func (il *itemList) peek() any {
 	return il.head.it
 }
 
-func (il *itemList) dequeue() interface{} {
+func (il *itemList) dequeue() any {
 	if il.head == nil {
 		return nil
 	}
@@ -191,7 +193,7 @@ type goAway struct {
 	code      http2.ErrCode
 	debugData []byte
 	headsUp   bool
-	closeConn bool
+	closeConn error // if set, loopyWriter will exit, resulting in conn closure
 }
 
 func (*goAway) isTransportResponseFrame() bool { return false }
@@ -209,6 +211,14 @@ type outFlowControlSizeRequest struct {
 
 func (*outFlowControlSizeRequest) isTransportResponseFrame() bool { return false }
 
+// closeConnection is an instruction to tell the loopy writer to flush the
+// framer and exit, which will cause the transport's connection to be closed
+// (by the client or server).  The transport itself will close after the reader
+// encounters the EOF caused by the connection closure.
+type closeConnection struct{}
+
+func (closeConnection) isTransportResponseFrame() bool { return false }
+
 type outStreamState int
 
 const (
@@ -326,7 +336,7 @@ func (c *controlBuffer) put(it cbItem) error {
 	return err
 }
 
-func (c *controlBuffer) executeAndPut(f func(it interface{}) bool, it cbItem) (bool, error) {
+func (c *controlBuffer) executeAndPut(f func(it any) bool, it cbItem) (bool, error) {
 	var wakeUp bool
 	c.mu.Lock()
 	if c.err != nil {
@@ -363,7 +373,7 @@ func (c *controlBuffer) executeAndPut(f func(it interface{}) bool, it cbItem) (b
 }
 
 // Note argument f should never be nil.
-func (c *controlBuffer) execute(f func(it interface{}) bool, it interface{}) (bool, error) {
+func (c *controlBuffer) execute(f func(it any) bool, it any) (bool, error) {
 	c.mu.Lock()
 	if c.err != nil {
 		c.mu.Unlock()
@@ -377,7 +387,7 @@ func (c *controlBuffer) execute(f func(it interface{}) bool, it interface{}) (bo
 	return true, nil
 }
 
-func (c *controlBuffer) get(block bool) (interface{}, error) {
+func (c *controlBuffer) get(block bool) (any, error) {
 	for {
 		c.mu.Lock()
 		if c.err != nil {
@@ -408,7 +418,7 @@ func (c *controlBuffer) get(block bool) (interface{}, error) {
 		select {
 		case <-c.ch:
 		case <-c.done:
-			return nil, ErrConnClosing
+			return nil, errors.New("transport closed by client")
 		}
 	}
 }
@@ -478,12 +488,14 @@ type loopyWriter struct {
 	hEnc          *hpack.Encoder // HPACK encoder.
 	bdpEst        *bdpEstimator
 	draining      bool
+	conn          net.Conn
+	logger        *grpclog.PrefixLogger
 
 	// Side-specific handlers
 	ssGoAwayHandler func(*goAway) (bool, error)
 }
 
-func newLoopyWriter(s side, fr *framer, cbuf *controlBuffer, bdpEst *bdpEstimator) *loopyWriter {
+func newLoopyWriter(s side, fr *framer, cbuf *controlBuffer, bdpEst *bdpEstimator, conn net.Conn, logger *grpclog.PrefixLogger) *loopyWriter {
 	var buf bytes.Buffer
 	l := &loopyWriter{
 		side:          s,
@@ -496,6 +508,8 @@ func newLoopyWriter(s side, fr *framer, cbuf *controlBuffer, bdpEst *bdpEstimato
 		hBuf:          &buf,
 		hEnc:          hpack.NewEncoder(&buf),
 		bdpEst:        bdpEst,
+		conn:          conn,
+		logger:        logger,
 	}
 	return l
 }
@@ -513,23 +527,26 @@ const minBatchSize = 1000
 // 2. Stream level flow control quota available.
 //
 // In each iteration of run loop, other than processing the incoming control
-// frame, loopy calls processData, which processes one node from the activeStreams linked-list.
-// This results in writing of HTTP2 frames into an underlying write buffer.
-// When there's no more control frames to read from controlBuf, loopy flushes the write buffer.
-// As an optimization, to increase the batch size for each flush, loopy yields the processor, once
-// if the batch size is too low to give stream goroutines a chance to fill it up.
+// frame, loopy calls processData, which processes one node from the
+// activeStreams linked-list.  This results in writing of HTTP2 frames into an
+// underlying write buffer.  When there's no more control frames to read from
+// controlBuf, loopy flushes the write buffer.  As an optimization, to increase
+// the batch size for each flush, loopy yields the processor, once if the batch
+// size is too low to give stream goroutines a chance to fill it up.
+//
+// Upon exiting, if the error causing the exit is not an I/O error, run()
+// flushes and closes the underlying connection.  Otherwise, the connection is
+// left open to allow the I/O error to be encountered by the reader instead.
 func (l *loopyWriter) run() (err error) {
 	defer func() {
-		if err == ErrConnClosing {
-			// Don't log ErrConnClosing as error since it happens
-			// 1. When the connection is closed by some other known issue.
-			// 2. User closed the connection.
-			// 3. A graceful close of connection.
-			if logger.V(logLevel) {
-				logger.Infof("transport: loopyWriter.run returning. %v", err)
-			}
-			err = nil
+		if l.logger.V(logLevel) {
+			l.logger.Infof("loopyWriter exiting with error: %v", err)
 		}
+		if !isIOError(err) {
+			l.framer.writer.Flush()
+			l.conn.Close()
+		}
+		l.cbuf.finish()
 	}()
 	for {
 		it, err := l.cbuf.get(true)
@@ -574,7 +591,6 @@ func (l *loopyWriter) run() (err error) {
 			}
 			l.framer.writer.Flush()
 			break hasdata
-
 		}
 	}
 }
@@ -583,11 +599,11 @@ func (l *loopyWriter) outgoingWindowUpdateHandler(w *outgoingWindowUpdate) error
 	return l.framer.fr.WriteWindowUpdate(w.streamID, w.increment)
 }
 
-func (l *loopyWriter) incomingWindowUpdateHandler(w *incomingWindowUpdate) error {
+func (l *loopyWriter) incomingWindowUpdateHandler(w *incomingWindowUpdate) {
 	// Otherwise update the quota.
 	if w.streamID == 0 {
 		l.sendQuota += w.increment
-		return nil
+		return
 	}
 	// Find the stream and update it.
 	if str, ok := l.estdStreams[w.streamID]; ok {
@@ -595,10 +611,9 @@ func (l *loopyWriter) incomingWindowUpdateHandler(w *incomingWindowUpdate) error
 		if strQuota := int(l.oiws) - str.bytesOutStanding; strQuota > 0 && str.state == waitingOnStreamQuota {
 			str.state = active
 			l.activeStreams.enqueue(str)
-			return nil
+			return
 		}
 	}
-	return nil
 }
 
 func (l *loopyWriter) outgoingSettingsHandler(s *outgoingSettings) error {
@@ -606,13 +621,11 @@ func (l *loopyWriter) outgoingSettingsHandler(s *outgoingSettings) error {
 }
 
 func (l *loopyWriter) incomingSettingsHandler(s *incomingSettings) error {
-	if err := l.applySettings(s.ss); err != nil {
-		return err
-	}
+	l.applySettings(s.ss)
 	return l.framer.fr.WriteSettingsAck()
 }
 
-func (l *loopyWriter) registerStreamHandler(h *registerStream) error {
+func (l *loopyWriter) registerStreamHandler(h *registerStream) {
 	str := &outStream{
 		id:    h.streamID,
 		state: empty,
@@ -620,15 +633,14 @@ func (l *loopyWriter) registerStreamHandler(h *registerStream) error {
 		wq:    h.wq,
 	}
 	l.estdStreams[h.streamID] = str
-	return nil
 }
 
 func (l *loopyWriter) headerHandler(h *headerFrame) error {
 	if l.side == serverSide {
 		str, ok := l.estdStreams[h.streamID]
 		if !ok {
-			if logger.V(logLevel) {
-				logger.Warningf("transport: loopy doesn't recognize the stream: %d", h.streamID)
+			if l.logger.V(logLevel) {
+				l.logger.Infof("Unrecognized streamID %d in loopyWriter", h.streamID)
 			}
 			return nil
 		}
@@ -655,19 +667,20 @@ func (l *loopyWriter) headerHandler(h *headerFrame) error {
 		itl:   &itemList{},
 		wq:    h.wq,
 	}
-	str.itl.enqueue(h)
-	return l.originateStream(str)
+	return l.originateStream(str, h)
 }
 
-func (l *loopyWriter) originateStream(str *outStream) error {
-	hdr := str.itl.dequeue().(*headerFrame)
-	if err := hdr.initStream(str.id); err != nil {
-		if err == ErrConnClosing {
-			return err
-		}
-		// Other errors(errStreamDrain) need not close transport.
+func (l *loopyWriter) originateStream(str *outStream, hdr *headerFrame) error {
+	// l.draining is set when handling GoAway. In which case, we want to avoid
+	// creating new streams.
+	if l.draining {
+		// TODO: provide a better error with the reason we are in draining.
+		hdr.onOrphaned(errStreamDrain)
 		return nil
 	}
+	if err := hdr.initStream(str.id); err != nil {
+		return err
+	}
 	if err := l.writeHeader(str.id, hdr.endStream, hdr.hf, hdr.onWrite); err != nil {
 		return err
 	}
@@ -682,8 +695,8 @@ func (l *loopyWriter) writeHeader(streamID uint32, endStream bool, hf []hpack.He
 	l.hBuf.Reset()
 	for _, f := range hf {
 		if err := l.hEnc.WriteField(f); err != nil {
-			if logger.V(logLevel) {
-				logger.Warningf("transport: loopyWriter.writeHeader encountered error while encoding headers: %v", err)
+			if l.logger.V(logLevel) {
+				l.logger.Warningf("Encountered error while encoding headers: %v", err)
 			}
 		}
 	}
@@ -721,10 +734,10 @@ func (l *loopyWriter) writeHeader(streamID uint32, endStream bool, hf []hpack.He
 	return nil
 }
 
-func (l *loopyWriter) preprocessData(df *dataFrame) error {
+func (l *loopyWriter) preprocessData(df *dataFrame) {
 	str, ok := l.estdStreams[df.streamID]
 	if !ok {
-		return nil
+		return
 	}
 	// If we got data for a stream it means that
 	// stream was originated and the headers were sent out.
@@ -733,7 +746,6 @@ func (l *loopyWriter) preprocessData(df *dataFrame) error {
 		str.state = active
 		l.activeStreams.enqueue(str)
 	}
-	return nil
 }
 
 func (l *loopyWriter) pingHandler(p *ping) error {
@@ -744,9 +756,8 @@ func (l *loopyWriter) pingHandler(p *ping) error {
 
 }
 
-func (l *loopyWriter) outFlowControlSizeRequestHandler(o *outFlowControlSizeRequest) error {
+func (l *loopyWriter) outFlowControlSizeRequestHandler(o *outFlowControlSizeRequest) {
 	o.resp <- l.sendQuota
-	return nil
 }
 
 func (l *loopyWriter) cleanupStreamHandler(c *cleanupStream) error {
@@ -763,8 +774,9 @@ func (l *loopyWriter) cleanupStreamHandler(c *cleanupStream) error {
 			return err
 		}
 	}
-	if l.side == clientSide && l.draining && len(l.estdStreams) == 0 {
-		return ErrConnClosing
+	if l.draining && len(l.estdStreams) == 0 {
+		// Flush and close the connection; we are done with it.
+		return errors.New("finished processing active streams while in draining mode")
 	}
 	return nil
 }
@@ -799,7 +811,8 @@ func (l *loopyWriter) incomingGoAwayHandler(*incomingGoAway) error {
 	if l.side == clientSide {
 		l.draining = true
 		if len(l.estdStreams) == 0 {
-			return ErrConnClosing
+			// Flush and close the connection; we are done with it.
+			return errors.New("received GOAWAY with no active streams")
 		}
 	}
 	return nil
@@ -817,10 +830,10 @@ func (l *loopyWriter) goAwayHandler(g *goAway) error {
 	return nil
 }
 
-func (l *loopyWriter) handle(i interface{}) error {
+func (l *loopyWriter) handle(i any) error {
 	switch i := i.(type) {
 	case *incomingWindowUpdate:
-		return l.incomingWindowUpdateHandler(i)
+		l.incomingWindowUpdateHandler(i)
 	case *outgoingWindowUpdate:
 		return l.outgoingWindowUpdateHandler(i)
 	case *incomingSettings:
@@ -830,7 +843,7 @@ func (l *loopyWriter) handle(i interface{}) error {
 	case *headerFrame:
 		return l.headerHandler(i)
 	case *registerStream:
-		return l.registerStreamHandler(i)
+		l.registerStreamHandler(i)
 	case *cleanupStream:
 		return l.cleanupStreamHandler(i)
 	case *earlyAbortStream:
@@ -838,19 +851,24 @@ func (l *loopyWriter) handle(i interface{}) error {
 	case *incomingGoAway:
 		return l.incomingGoAwayHandler(i)
 	case *dataFrame:
-		return l.preprocessData(i)
+		l.preprocessData(i)
 	case *ping:
 		return l.pingHandler(i)
 	case *goAway:
 		return l.goAwayHandler(i)
 	case *outFlowControlSizeRequest:
-		return l.outFlowControlSizeRequestHandler(i)
+		l.outFlowControlSizeRequestHandler(i)
+	case closeConnection:
+		// Just return a non-I/O error and run() will flush and close the
+		// connection.
+		return ErrConnClosing
 	default:
 		return fmt.Errorf("transport: unknown control message type %T", i)
 	}
+	return nil
 }
 
-func (l *loopyWriter) applySettings(ss []http2.Setting) error {
+func (l *loopyWriter) applySettings(ss []http2.Setting) {
 	for _, s := range ss {
 		switch s.ID {
 		case http2.SettingInitialWindowSize:
@@ -869,7 +887,6 @@ func (l *loopyWriter) applySettings(ss []http2.Setting) error {
 			updateHeaderTblSize(l.hEnc, s.Val)
 		}
 	}
-	return nil
 }
 
 // processData removes the first stream from active streams, writes out at most 16KB
@@ -903,7 +920,7 @@ func (l *loopyWriter) processData() (bool, error) {
 				return false, err
 			}
 			if err := l.cleanupStreamHandler(trailer.cleanup); err != nil {
-				return false, nil
+				return false, err
 			}
 		} else {
 			l.activeStreams.enqueue(str)

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

@@ -47,3 +47,9 @@ const (
 	defaultClientMaxHeaderListSize = uint32(16 << 20)
 	defaultServerMaxHeaderListSize = uint32(16 << 20)
 )
+
+// MaxStreamID is the upper bound for the stream ID before the current
+// transport gracefully closes and new transport is created for subsequent RPCs.
+// This is set to 75% of 2^31-1. Streams are identified with an unsigned 31-bit
+// integer. It's exported so that tests can override it.
+var MaxStreamID = uint32(math.MaxInt32 * 3 / 4)

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

@@ -39,6 +39,7 @@ import (
 	"golang.org/x/net/http2"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/internal/grpclog"
 	"google.golang.org/grpc/internal/grpcutil"
 	"google.golang.org/grpc/metadata"
 	"google.golang.org/grpc/peer"
@@ -46,40 +47,65 @@ import (
 	"google.golang.org/grpc/status"
 )
 
-// NewServerHandlerTransport returns a ServerTransport handling gRPC
-// from inside an http.Handler. It requires that the http Server
-// supports HTTP/2.
+// NewServerHandlerTransport returns a ServerTransport handling gRPC from
+// inside an http.Handler, or writes an HTTP error to w and returns an error.
+// It requires that the http Server supports HTTP/2.
 func NewServerHandlerTransport(w http.ResponseWriter, r *http.Request, stats []stats.Handler) (ServerTransport, error) {
 	if r.ProtoMajor != 2 {
-		return nil, errors.New("gRPC requires HTTP/2")
+		msg := "gRPC requires HTTP/2"
+		http.Error(w, msg, http.StatusBadRequest)
+		return nil, errors.New(msg)
 	}
 	if r.Method != "POST" {
-		return nil, errors.New("invalid gRPC request method")
+		msg := fmt.Sprintf("invalid gRPC request method %q", r.Method)
+		http.Error(w, msg, http.StatusBadRequest)
+		return nil, errors.New(msg)
 	}
 	contentType := r.Header.Get("Content-Type")
 	// TODO: do we assume contentType is lowercase? we did before
 	contentSubtype, validContentType := grpcutil.ContentSubtype(contentType)
 	if !validContentType {
-		return nil, errors.New("invalid gRPC request content-type")
+		msg := fmt.Sprintf("invalid gRPC request content-type %q", contentType)
+		http.Error(w, msg, http.StatusUnsupportedMediaType)
+		return nil, errors.New(msg)
 	}
 	if _, ok := w.(http.Flusher); !ok {
-		return nil, errors.New("gRPC requires a ResponseWriter supporting http.Flusher")
+		msg := "gRPC requires a ResponseWriter supporting http.Flusher"
+		http.Error(w, msg, http.StatusInternalServerError)
+		return nil, errors.New(msg)
 	}
 
+	var localAddr net.Addr
+	if la := r.Context().Value(http.LocalAddrContextKey); la != nil {
+		localAddr, _ = la.(net.Addr)
+	}
+	var authInfo credentials.AuthInfo
+	if r.TLS != nil {
+		authInfo = credentials.TLSInfo{State: *r.TLS, CommonAuthInfo: credentials.CommonAuthInfo{SecurityLevel: credentials.PrivacyAndIntegrity}}
+	}
+	p := peer.Peer{
+		Addr:      strAddr(r.RemoteAddr),
+		LocalAddr: localAddr,
+		AuthInfo:  authInfo,
+	}
 	st := &serverHandlerTransport{
 		rw:             w,
 		req:            r,
 		closedCh:       make(chan struct{}),
 		writes:         make(chan func()),
+		peer:           p,
 		contentType:    contentType,
 		contentSubtype: contentSubtype,
 		stats:          stats,
 	}
+	st.logger = prefixLoggerForServerHandlerTransport(st)
 
 	if v := r.Header.Get("grpc-timeout"); v != "" {
 		to, err := decodeTimeout(v)
 		if err != nil {
-			return nil, status.Errorf(codes.Internal, "malformed time-out: %v", err)
+			msg := fmt.Sprintf("malformed grpc-timeout: %v", err)
+			http.Error(w, msg, http.StatusBadRequest)
+			return nil, status.Error(codes.Internal, msg)
 		}
 		st.timeoutSet = true
 		st.timeout = to
@@ -97,7 +123,9 @@ func NewServerHandlerTransport(w http.ResponseWriter, r *http.Request, stats []s
 		for _, v := range vv {
 			v, err := decodeMetadataHeader(k, v)
 			if err != nil {
-				return nil, status.Errorf(codes.Internal, "malformed binary metadata: %v", err)
+				msg := fmt.Sprintf("malformed binary metadata %q in header %q: %v", v, k, err)
+				http.Error(w, msg, http.StatusBadRequest)
+				return nil, status.Error(codes.Internal, msg)
 			}
 			metakv = append(metakv, k, v)
 		}
@@ -120,6 +148,8 @@ type serverHandlerTransport struct {
 
 	headerMD metadata.MD
 
+	peer peer.Peer
+
 	closeOnce sync.Once
 	closedCh  chan struct{} // closed on Close
 
@@ -138,16 +168,26 @@ type serverHandlerTransport struct {
 	// TODO make sure this is consistent across handler_server and http2_server
 	contentSubtype string
 
-	stats []stats.Handler
+	stats  []stats.Handler
+	logger *grpclog.PrefixLogger
 }
 
-func (ht *serverHandlerTransport) Close() {
-	ht.closeOnce.Do(ht.closeCloseChanOnce)
+func (ht *serverHandlerTransport) Close(err error) {
+	ht.closeOnce.Do(func() {
+		if ht.logger.V(logLevel) {
+			ht.logger.Infof("Closing: %v", err)
+		}
+		close(ht.closedCh)
+	})
 }
 
-func (ht *serverHandlerTransport) closeCloseChanOnce() { close(ht.closedCh) }
-
-func (ht *serverHandlerTransport) RemoteAddr() net.Addr { return strAddr(ht.req.RemoteAddr) }
+func (ht *serverHandlerTransport) Peer() *peer.Peer {
+	return &peer.Peer{
+		Addr:      ht.peer.Addr,
+		LocalAddr: ht.peer.LocalAddr,
+		AuthInfo:  ht.peer.AuthInfo,
+	}
+}
 
 // strAddr is a net.Addr backed by either a TCP "ip:port" string, or
 // the empty string if unknown.
@@ -202,18 +242,20 @@ func (ht *serverHandlerTransport) WriteStatus(s *Stream, st *status.Status) erro
 			h.Set("Grpc-Message", encodeGrpcMessage(m))
 		}
 
+		s.hdrMu.Lock()
 		if p := st.Proto(); p != nil && len(p.Details) > 0 {
+			delete(s.trailer, grpcStatusDetailsBinHeader)
 			stBytes, err := proto.Marshal(p)
 			if err != nil {
 				// TODO: return error instead, when callers are able to handle it.
 				panic(err)
 			}
 
-			h.Set("Grpc-Status-Details-Bin", encodeBinHeader(stBytes))
+			h.Set(grpcStatusDetailsBinHeader, encodeBinHeader(stBytes))
 		}
 
-		if md := s.Trailer(); len(md) > 0 {
-			for k, vv := range md {
+		if len(s.trailer) > 0 {
+			for k, vv := range s.trailer {
 				// Clients don't tolerate reading restricted headers after some non restricted ones were sent.
 				if isReservedHeader(k) {
 					continue
@@ -225,6 +267,7 @@ func (ht *serverHandlerTransport) WriteStatus(s *Stream, st *status.Status) erro
 				}
 			}
 		}
+		s.hdrMu.Unlock()
 	})
 
 	if err == nil { // transport has not been closed
@@ -236,7 +279,7 @@ func (ht *serverHandlerTransport) WriteStatus(s *Stream, st *status.Status) erro
 			})
 		}
 	}
-	ht.Close()
+	ht.Close(errors.New("finished writing status"))
 	return err
 }
 
@@ -269,7 +312,7 @@ func (ht *serverHandlerTransport) writeCommonHeaders(s *Stream) {
 }
 
 // writeCustomHeaders sets custom headers set on the stream via SetHeader
-// on the first write call (Write, WriteHeader, or WriteStatus).
+// on the first write call (Write, WriteHeader, or WriteStatus)
 func (ht *serverHandlerTransport) writeCustomHeaders(s *Stream) {
 	h := ht.rw.Header()
 
@@ -326,10 +369,8 @@ func (ht *serverHandlerTransport) WriteHeader(s *Stream, md metadata.MD) error {
 	return err
 }
 
-func (ht *serverHandlerTransport) HandleStreams(startStream func(*Stream), traceCtx func(context.Context, string) context.Context) {
+func (ht *serverHandlerTransport) HandleStreams(ctx context.Context, startStream func(*Stream)) {
 	// With this transport type there will be exactly 1 stream: this HTTP request.
-
-	ctx := ht.req.Context()
 	var cancel context.CancelFunc
 	if ht.timeoutSet {
 		ctx, cancel = context.WithTimeout(ctx, ht.timeout)
@@ -346,37 +387,22 @@ func (ht *serverHandlerTransport) HandleStreams(startStream func(*Stream), trace
 		case <-ht.req.Context().Done():
 		}
 		cancel()
-		ht.Close()
+		ht.Close(errors.New("request is done processing"))
 	}()
 
-	req := ht.req
-
-	s := &Stream{
-		id:             0, // irrelevant
-		requestRead:    func(int) {},
-		cancel:         cancel,
-		buf:            newRecvBuffer(),
-		st:             ht,
-		method:         req.URL.Path,
-		recvCompress:   req.Header.Get("grpc-encoding"),
-		contentSubtype: ht.contentSubtype,
-	}
-	pr := &peer.Peer{
-		Addr: ht.RemoteAddr(),
-	}
-	if req.TLS != nil {
-		pr.AuthInfo = credentials.TLSInfo{State: *req.TLS, CommonAuthInfo: credentials.CommonAuthInfo{SecurityLevel: credentials.PrivacyAndIntegrity}}
-	}
 	ctx = metadata.NewIncomingContext(ctx, ht.headerMD)
-	s.ctx = peer.NewContext(ctx, pr)
-	for _, sh := range ht.stats {
-		s.ctx = sh.TagRPC(s.ctx, &stats.RPCTagInfo{FullMethodName: s.method})
-		inHeader := &stats.InHeader{
-			FullMethod:  s.method,
-			RemoteAddr:  ht.RemoteAddr(),
-			Compression: s.recvCompress,
-		}
-		sh.HandleRPC(s.ctx, inHeader)
+	req := ht.req
+	s := &Stream{
+		id:               0, // irrelevant
+		ctx:              ctx,
+		requestRead:      func(int) {},
+		cancel:           cancel,
+		buf:              newRecvBuffer(),
+		st:               ht,
+		method:           req.URL.Path,
+		recvCompress:     req.Header.Get("grpc-encoding"),
+		contentSubtype:   ht.contentSubtype,
+		headerWireLength: 0, // won't have access to header wire length until golang/go#18997.
 	}
 	s.trReader = &transportReader{
 		reader:        &recvBufferReader{ctx: s.ctx, ctxDone: s.ctx.Done(), recv: s.buf, freeBuffer: func(*bytes.Buffer) {}},
@@ -435,7 +461,7 @@ func (ht *serverHandlerTransport) IncrMsgSent() {}
 
 func (ht *serverHandlerTransport) IncrMsgRecv() {}
 
-func (ht *serverHandlerTransport) Drain() {
+func (ht *serverHandlerTransport) Drain(debugData string) {
 	panic("Drain() is not implemented")
 }
 

vendor/google.golang.org/grpc/internal/transport/http2_client.go

@@ -36,13 +36,15 @@ import (
 	"golang.org/x/net/http2/hpack"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/internal"
 	"google.golang.org/grpc/internal/channelz"
 	icredentials "google.golang.org/grpc/internal/credentials"
+	"google.golang.org/grpc/internal/grpclog"
 	"google.golang.org/grpc/internal/grpcsync"
 	"google.golang.org/grpc/internal/grpcutil"
 	imetadata "google.golang.org/grpc/internal/metadata"
 	istatus "google.golang.org/grpc/internal/status"
-	"google.golang.org/grpc/internal/syscall"
+	isyscall "google.golang.org/grpc/internal/syscall"
 	"google.golang.org/grpc/internal/transport/networktype"
 	"google.golang.org/grpc/keepalive"
 	"google.golang.org/grpc/metadata"
@@ -59,11 +61,15 @@ var clientConnectionCounter uint64
 
 // http2Client implements the ClientTransport interface with HTTP2.
 type http2Client struct {
-	lastRead   int64 // Keep this field 64-bit aligned. Accessed atomically.
-	ctx        context.Context
-	cancel     context.CancelFunc
-	ctxDone    <-chan struct{} // Cache the ctx.Done() chan.
-	userAgent  string
+	lastRead  int64 // Keep this field 64-bit aligned. Accessed atomically.
+	ctx       context.Context
+	cancel    context.CancelFunc
+	ctxDone   <-chan struct{} // Cache the ctx.Done() chan.
+	userAgent string
+	// address contains the resolver returned address for this transport.
+	// If the `ServerName` field is set, it takes precedence over `CallHdr.Host`
+	// passed to `NewStream`, when determining the :authority header.
+	address    resolver.Address
 	md         metadata.MD
 	conn       net.Conn // underlying communication channel
 	loopy      *loopyWriter
@@ -136,12 +142,12 @@ type http2Client struct {
 	channelzID *channelz.Identifier
 	czData     *channelzData
 
-	onGoAway func(GoAwayReason)
-	onClose  func()
+	onClose func(GoAwayReason)
 
 	bufferPool *bufferPool
 
 	connectionID uint64
+	logger       *grpclog.PrefixLogger
 }
 
 func dial(ctx context.Context, fn func(context.Context, string) (net.Conn, error), addr resolver.Address, useProxy bool, grpcUA string) (net.Conn, error) {
@@ -171,7 +177,7 @@ func dial(ctx context.Context, fn func(context.Context, string) (net.Conn, error
 	if networkType == "tcp" && useProxy {
 		return proxyDial(ctx, address, grpcUA)
 	}
-	return (&net.Dialer{}).DialContext(ctx, networkType, address)
+	return internal.NetDialerWithTCPKeepalive().DialContext(ctx, networkType, address)
 }
 
 func isTemporary(err error) bool {
@@ -193,7 +199,7 @@ func isTemporary(err error) bool {
 // newHTTP2Client constructs a connected ClientTransport to addr based on HTTP2
 // and starts to receive messages on it. Non-nil error returns if construction
 // fails.
-func newHTTP2Client(connectCtx, ctx context.Context, addr resolver.Address, opts ConnectOptions, onGoAway func(GoAwayReason), onClose func()) (_ *http2Client, err error) {
+func newHTTP2Client(connectCtx, ctx context.Context, addr resolver.Address, opts ConnectOptions, onClose func(GoAwayReason)) (_ *http2Client, err error) {
 	scheme := "http"
 	ctx, cancel := context.WithCancel(ctx)
 	defer func() {
@@ -213,7 +219,7 @@ func newHTTP2Client(connectCtx, ctx context.Context, addr resolver.Address, opts
 		if opts.FailOnNonTempDialError {
 			return nil, connectionErrorf(isTemporary(err), err, "transport: error while dialing: %v", err)
 		}
-		return nil, connectionErrorf(true, err, "transport: Error while dialing %v", err)
+		return nil, connectionErrorf(true, err, "transport: Error while dialing: %v", err)
 	}
 
 	// Any further errors will close the underlying connection
@@ -238,8 +244,11 @@ func newHTTP2Client(connectCtx, ctx context.Context, addr resolver.Address, opts
 	go func(conn net.Conn) {
 		defer ctxMonitorDone.Fire() // Signal this goroutine has exited.
 		<-newClientCtx.Done()       // Block until connectCtx expires or the defer above executes.
-		if connectCtx.Err() != nil {
+		if err := connectCtx.Err(); err != nil {
 			// connectCtx expired before exiting the function.  Hard close the connection.
+			if logger.V(logLevel) {
+				logger.Infof("Aborting due to connect deadline expiring: %v", err)
+			}
 			conn.Close()
 		}
 	}(conn)
@@ -254,7 +263,7 @@ func newHTTP2Client(connectCtx, ctx context.Context, addr resolver.Address, opts
 	}
 	keepaliveEnabled := false
 	if kp.Time != infinity {
-		if err = syscall.SetTCPUserTimeout(conn, kp.Timeout); err != nil {
+		if err = isyscall.SetTCPUserTimeout(conn, kp.Timeout); err != nil {
 			return nil, connectionErrorf(false, err, "transport: failed to set TCP_USER_TIMEOUT: %v", err)
 		}
 		keepaliveEnabled = true
@@ -314,6 +323,7 @@ func newHTTP2Client(connectCtx, ctx context.Context, addr resolver.Address, opts
 		cancel:                cancel,
 		userAgent:             opts.UserAgent,
 		registeredCompressors: grpcutil.RegisteredCompressors(),
+		address:               addr,
 		conn:                  conn,
 		remoteAddr:            conn.RemoteAddr(),
 		localAddr:             conn.LocalAddr(),
@@ -321,7 +331,7 @@ func newHTTP2Client(connectCtx, ctx context.Context, addr resolver.Address, opts
 		readerDone:            make(chan struct{}),
 		writerDone:            make(chan struct{}),
 		goAway:                make(chan struct{}),
-		framer:                newFramer(conn, writeBufSize, readBufSize, maxHeaderListSize),
+		framer:                newFramer(conn, writeBufSize, readBufSize, opts.SharedWriteBuffer, maxHeaderListSize),
 		fc:                    &trInFlow{limit: uint32(icwz)},
 		scheme:                scheme,
 		activeStreams:         make(map[uint32]*Stream),
@@ -335,11 +345,11 @@ func newHTTP2Client(connectCtx, ctx context.Context, addr resolver.Address, opts
 		streamQuota:           defaultMaxStreamsClient,
 		streamsQuotaAvailable: make(chan struct{}, 1),
 		czData:                new(channelzData),
-		onGoAway:              onGoAway,
 		keepaliveEnabled:      keepaliveEnabled,
 		bufferPool:            newBufferPool(),
 		onClose:               onClose,
 	}
+	t.logger = prefixLoggerForClientTransport(t)
 	// Add peer information to the http2client context.
 	t.ctx = peer.NewContext(t.ctx, t.getPeer())
 
@@ -438,17 +448,8 @@ func newHTTP2Client(connectCtx, ctx context.Context, addr resolver.Address, opts
 		return nil, err
 	}
 	go func() {
-		t.loopy = newLoopyWriter(clientSide, t.framer, t.controlBuf, t.bdpEst)
-		err := t.loopy.run()
-		if err != nil {
-			if logger.V(logLevel) {
-				logger.Errorf("transport: loopyWriter.run returning. Err: %v", err)
-			}
-		}
-		// Do not close the transport.  Let reader goroutine handle it since
-		// there might be data in the buffers.
-		t.conn.Close()
-		t.controlBuf.finish()
+		t.loopy = newLoopyWriter(clientSide, t.framer, t.controlBuf, t.bdpEst, t.conn, t.logger)
+		t.loopy.run()
 		close(t.writerDone)
 	}()
 	return t, nil
@@ -493,8 +494,9 @@ func (t *http2Client) newStream(ctx context.Context, callHdr *CallHdr) *Stream {
 
 func (t *http2Client) getPeer() *peer.Peer {
 	return &peer.Peer{
-		Addr:     t.remoteAddr,
-		AuthInfo: t.authInfo, // Can be nil
+		Addr:      t.remoteAddr,
+		AuthInfo:  t.authInfo, // Can be nil
+		LocalAddr: t.localAddr,
 	}
 }
 
@@ -702,6 +704,18 @@ func (e NewStreamError) Error() string {
 // streams.  All non-nil errors returned will be *NewStreamError.
 func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (*Stream, error) {
 	ctx = peer.NewContext(ctx, t.getPeer())
+
+	// ServerName field of the resolver returned address takes precedence over
+	// Host field of CallHdr to determine the :authority header. This is because,
+	// the ServerName field takes precedence for server authentication during
+	// TLS handshake, and the :authority header should match the value used
+	// for server authentication.
+	if t.address.ServerName != "" {
+		newCallHdr := *callHdr
+		newCallHdr.Host = t.address.ServerName
+		callHdr = &newCallHdr
+	}
+
 	headerFields, err := t.createHeaderFields(ctx, callHdr)
 	if err != nil {
 		return nil, &NewStreamError{Err: err, AllowTransparentRetry: false}
@@ -726,15 +740,12 @@ func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (*Stream,
 		endStream: false,
 		initStream: func(id uint32) error {
 			t.mu.Lock()
-			if state := t.state; state != reachable {
+			// TODO: handle transport closure in loopy instead and remove this
+			// initStream is never called when transport is draining.
+			if t.state == closing {
 				t.mu.Unlock()
-				// Do a quick cleanup.
-				err := error(errStreamDrain)
-				if state == closing {
-					err = ErrConnClosing
-				}
-				cleanup(err)
-				return err
+				cleanup(ErrConnClosing)
+				return ErrConnClosing
 			}
 			if channelz.IsOn() {
 				atomic.AddInt64(&t.czData.streamsStarted, 1)
@@ -752,7 +763,8 @@ func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (*Stream,
 	}
 	firstTry := true
 	var ch chan struct{}
-	checkForStreamQuota := func(it interface{}) bool {
+	transportDrainRequired := false
+	checkForStreamQuota := func(it any) bool {
 		if t.streamQuota <= 0 { // Can go negative if server decreases it.
 			if firstTry {
 				t.waitingStreams++
@@ -767,10 +779,15 @@ func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (*Stream,
 		h := it.(*headerFrame)
 		h.streamID = t.nextID
 		t.nextID += 2
+
+		// Drain client transport if nextID > MaxStreamID which signals gRPC that
+		// the connection is closed and a new one must be created for subsequent RPCs.
+		transportDrainRequired = t.nextID > MaxStreamID
+
 		s.id = h.streamID
 		s.fc = &inFlow{limit: uint32(t.initialWindowSize)}
 		t.mu.Lock()
-		if t.activeStreams == nil { // Can be niled from Close().
+		if t.state == draining || t.activeStreams == nil { // Can be niled from Close().
 			t.mu.Unlock()
 			return false // Don't create a stream if the transport is already closed.
 		}
@@ -785,7 +802,7 @@ func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (*Stream,
 		return true
 	}
 	var hdrListSizeErr error
-	checkForHeaderListSize := func(it interface{}) bool {
+	checkForHeaderListSize := func(it any) bool {
 		if t.maxSendHeaderListSize == nil {
 			return true
 		}
@@ -800,7 +817,7 @@ func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (*Stream,
 		return true
 	}
 	for {
-		success, err := t.controlBuf.executeAndPut(func(it interface{}) bool {
+		success, err := t.controlBuf.executeAndPut(func(it any) bool {
 			return checkForHeaderListSize(it) && checkForStreamQuota(it)
 		}, hdr)
 		if err != nil {
@@ -846,6 +863,12 @@ func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (*Stream,
 			sh.HandleRPC(s.ctx, outHeader)
 		}
 	}
+	if transportDrainRequired {
+		if t.logger.V(logLevel) {
+			t.logger.Infof("Draining transport: t.nextID > MaxStreamID")
+		}
+		t.GracefulClose()
+	}
 	return s, nil
 }
 
@@ -906,7 +929,7 @@ func (t *http2Client) closeStream(s *Stream, err error, rst bool, rstCode http2.
 		rst:     rst,
 		rstCode: rstCode,
 	}
-	addBackStreamQuota := func(interface{}) bool {
+	addBackStreamQuota := func(any) bool {
 		t.streamQuota++
 		if t.streamQuota > 0 && t.waitingStreams > 0 {
 			select {
@@ -934,9 +957,14 @@ func (t *http2Client) Close(err error) {
 		t.mu.Unlock()
 		return
 	}
+	if t.logger.V(logLevel) {
+		t.logger.Infof("Closing: %v", err)
+	}
 	// Call t.onClose ASAP to prevent the client from attempting to create new
 	// streams.
-	t.onClose()
+	if t.state != draining {
+		t.onClose(GoAwayInvalid)
+	}
 	t.state = closing
 	streams := t.activeStreams
 	t.activeStreams = nil
@@ -986,11 +1014,15 @@ func (t *http2Client) GracefulClose() {
 		t.mu.Unlock()
 		return
 	}
+	if t.logger.V(logLevel) {
+		t.logger.Infof("GracefulClose called")
+	}
+	t.onClose(GoAwayInvalid)
 	t.state = draining
 	active := len(t.activeStreams)
 	t.mu.Unlock()
 	if active == 0 {
-		t.Close(ErrConnClosing)
+		t.Close(connectionErrorf(true, nil, "no active streams left to process while draining"))
 		return
 	}
 	t.controlBuf.put(&incomingGoAway{})
@@ -1050,7 +1082,7 @@ func (t *http2Client) updateWindow(s *Stream, n uint32) {
 // for the transport and the stream based on the current bdp
 // estimation.
 func (t *http2Client) updateFlowControl(n uint32) {
-	updateIWS := func(interface{}) bool {
+	updateIWS := func(any) bool {
 		t.initialWindowSize = int32(n)
 		t.mu.Lock()
 		for _, s := range t.activeStreams {
@@ -1147,8 +1179,8 @@ func (t *http2Client) handleRSTStream(f *http2.RSTStreamFrame) {
 	}
 	statusCode, ok := http2ErrConvTab[f.ErrCode]
 	if !ok {
-		if logger.V(logLevel) {
-			logger.Warningf("transport: http2Client.handleRSTStream found no mapped gRPC status for the received http2 error %v", f.ErrCode)
+		if t.logger.V(logLevel) {
+			t.logger.Infof("Received a RST_STREAM frame with code %q, but found no mapped gRPC status", f.ErrCode)
 		}
 		statusCode = codes.Unknown
 	}
@@ -1203,7 +1235,7 @@ func (t *http2Client) handleSettings(f *http2.SettingsFrame, isFirst bool) {
 		}
 		updateFuncs = append(updateFuncs, updateStreamQuota)
 	}
-	t.controlBuf.executeAndPut(func(interface{}) bool {
+	t.controlBuf.executeAndPut(func(any) bool {
 		for _, f := range updateFuncs {
 			f()
 		}
@@ -1230,10 +1262,12 @@ func (t *http2Client) handleGoAway(f *http2.GoAwayFrame) {
 		t.mu.Unlock()
 		return
 	}
-	if f.ErrCode == http2.ErrCodeEnhanceYourCalm {
-		if logger.V(logLevel) {
-			logger.Infof("Client received GoAway with http2.ErrCodeEnhanceYourCalm.")
-		}
+	if f.ErrCode == http2.ErrCodeEnhanceYourCalm && string(f.DebugData()) == "too_many_pings" {
+		// When a client receives a GOAWAY with error code ENHANCE_YOUR_CALM and debug
+		// data equal to ASCII "too_many_pings", it should log the occurrence at a log level that is
+		// enabled by default and double the configure KEEPALIVE_TIME used for new connections
+		// on that channel.
+		logger.Errorf("Client received GoAway with error code ENHANCE_YOUR_CALM and debug data equal to ASCII \"too_many_pings\".")
 	}
 	id := f.LastStreamID
 	if id > 0 && id%2 == 0 {
@@ -1266,8 +1300,10 @@ func (t *http2Client) handleGoAway(f *http2.GoAwayFrame) {
 		// Notify the clientconn about the GOAWAY before we set the state to
 		// draining, to allow the client to stop attempting to create streams
 		// before disallowing new streams on this connection.
-		t.onGoAway(t.goAwayReason)
-		t.state = draining
+		if t.state != draining {
+			t.onClose(t.goAwayReason)
+			t.state = draining
+		}
 	}
 	// All streams with IDs greater than the GoAwayId
 	// and smaller than the previous GoAway ID should be killed.
@@ -1303,7 +1339,7 @@ func (t *http2Client) handleGoAway(f *http2.GoAwayFrame) {
 
 // setGoAwayReason sets the value of t.goAwayReason based
 // on the GoAway frame received.
-// It expects a lock on transport's mutext to be held by
+// It expects a lock on transport's mutex to be held by
 // the caller.
 func (t *http2Client) setGoAwayReason(f *http2.GoAwayFrame) {
 	t.goAwayReason = GoAwayNoReason
@@ -1365,7 +1401,6 @@ func (t *http2Client) operateHeaders(frame *http2.MetaHeadersFrame) {
 		mdata          = make(map[string][]string)
 		contentTypeErr = "malformed header: missing HTTP content-type"
 		grpcMessage    string
-		statusGen      *status.Status
 		recvCompress   string
 		httpStatusCode *int
 		httpStatusErr  string
@@ -1400,12 +1435,6 @@ func (t *http2Client) operateHeaders(frame *http2.MetaHeadersFrame) {
 			rawStatusCode = codes.Code(uint32(code))
 		case "grpc-message":
 			grpcMessage = decodeGrpcMessage(hf.Value)
-		case "grpc-status-details-bin":
-			var err error
-			statusGen, err = decodeGRPCStatusDetails(hf.Value)
-			if err != nil {
-				headerError = fmt.Sprintf("transport: malformed grpc-status-details-bin: %v", err)
-			}
 		case ":status":
 			if hf.Value == "200" {
 				httpStatusErr = ""
@@ -1471,14 +1500,15 @@ func (t *http2Client) operateHeaders(frame *http2.MetaHeadersFrame) {
 		return
 	}
 
-	isHeader := false
-
-	// If headerChan hasn't been closed yet
-	if atomic.CompareAndSwapUint32(&s.headerChanClosed, 0, 1) {
-		s.headerValid = true
-		if !endStream {
-			// HEADERS frame block carries a Response-Headers.
-			isHeader = true
+	// For headers, set them in s.header and close headerChan.  For trailers or
+	// trailers-only, closeStream will set the trailers and close headerChan as
+	// needed.
+	if !endStream {
+		// If headerChan hasn't been closed yet (expected, given we checked it
+		// above, but something else could have potentially closed the whole
+		// stream).
+		if atomic.CompareAndSwapUint32(&s.headerChanClosed, 0, 1) {
+			s.headerValid = true
 			// These values can be set without any synchronization because
 			// stream goroutine will read it only after seeing a closed
 			// headerChan which we'll close after setting this.
@@ -1486,15 +1516,12 @@ func (t *http2Client) operateHeaders(frame *http2.MetaHeadersFrame) {
 			if len(mdata) > 0 {
 				s.header = mdata
 			}
-		} else {
-			// HEADERS frame block carries a Trailers-Only.
-			s.noHeaders = true
+			close(s.headerChan)
 		}
-		close(s.headerChan)
 	}
 
 	for _, sh := range t.statsHandlers {
-		if isHeader {
+		if !endStream {
 			inHeader := &stats.InHeader{
 				Client:      true,
 				WireLength:  int(frame.Header().Length),
@@ -1516,13 +1543,12 @@ func (t *http2Client) operateHeaders(frame *http2.MetaHeadersFrame) {
 		return
 	}
 
-	if statusGen == nil {
-		statusGen = status.New(rawStatusCode, grpcMessage)
-	}
+	status := istatus.NewWithProto(rawStatusCode, grpcMessage, mdata[grpcStatusDetailsBinHeader])
 
-	// if client received END_STREAM from server while stream was still active, send RST_STREAM
-	rst := s.getState() == streamActive
-	t.closeStream(s, io.EOF, rst, http2.ErrCodeNo, statusGen, mdata, true)
+	// If client received END_STREAM from server while stream was still active,
+	// send RST_STREAM.
+	rstStream := s.getState() == streamActive
+	t.closeStream(s, io.EOF, rstStream, http2.ErrCodeNo, status, mdata, true)
 }
 
 // readServerPreface reads and handles the initial settings frame from the
@@ -1756,3 +1782,9 @@ func (t *http2Client) getOutFlowWindow() int64 {
 		return -2
 	}
 }
+
+func (t *http2Client) stateForTesting() transportState {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	return t.state
+}

vendor/google.golang.org/grpc/internal/transport/http2_server.go

@@ -21,6 +21,7 @@ package transport
 import (
 	"bytes"
 	"context"
+	"errors"
 	"fmt"
 	"io"
 	"math"
@@ -34,13 +35,16 @@ import (
 	"github.com/golang/protobuf/proto"
 	"golang.org/x/net/http2"
 	"golang.org/x/net/http2/hpack"
+	"google.golang.org/grpc/internal/grpclog"
 	"google.golang.org/grpc/internal/grpcutil"
+	"google.golang.org/grpc/internal/pretty"
 	"google.golang.org/grpc/internal/syscall"
 
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/credentials"
 	"google.golang.org/grpc/internal/channelz"
 	"google.golang.org/grpc/internal/grpcrand"
+	"google.golang.org/grpc/internal/grpcsync"
 	"google.golang.org/grpc/keepalive"
 	"google.golang.org/grpc/metadata"
 	"google.golang.org/grpc/peer"
@@ -64,18 +68,15 @@ var serverConnectionCounter uint64
 
 // http2Server implements the ServerTransport interface with HTTP2.
 type http2Server struct {
-	lastRead    int64 // Keep this field 64-bit aligned. Accessed atomically.
-	ctx         context.Context
-	done        chan struct{}
-	conn        net.Conn
-	loopy       *loopyWriter
-	readerDone  chan struct{} // sync point to enable testing.
-	writerDone  chan struct{} // sync point to enable testing.
-	remoteAddr  net.Addr
-	localAddr   net.Addr
-	authInfo    credentials.AuthInfo // auth info about the connection
-	inTapHandle tap.ServerInHandle
-	framer      *framer
+	lastRead        int64 // Keep this field 64-bit aligned. Accessed atomically.
+	done            chan struct{}
+	conn            net.Conn
+	loopy           *loopyWriter
+	readerDone      chan struct{} // sync point to enable testing.
+	loopyWriterDone chan struct{}
+	peer            peer.Peer
+	inTapHandle     tap.ServerInHandle
+	framer          *framer
 	// The max number of concurrent streams.
 	maxStreams uint32
 	// controlBuf delivers all the control related tasks (e.g., window
@@ -101,13 +102,13 @@ type http2Server struct {
 
 	mu sync.Mutex // guard the following
 
-	// drainChan is initialized when Drain() is called the first time.
-	// After which the server writes out the first GoAway(with ID 2^31-1) frame.
-	// Then an independent goroutine will be launched to later send the second GoAway.
-	// During this time we don't want to write another first GoAway(with ID 2^31 -1) frame.
-	// Thus call to Drain() will be a no-op if drainChan is already initialized since draining is
-	// already underway.
-	drainChan     chan struct{}
+	// drainEvent is initialized when Drain() is called the first time. After
+	// which the server writes out the first GoAway(with ID 2^31-1) frame. Then
+	// an independent goroutine will be launched to later send the second
+	// GoAway. During this time we don't want to write another first GoAway(with
+	// ID 2^31 -1) frame. Thus call to Drain() will be a no-op if drainEvent is
+	// already initialized since draining is already underway.
+	drainEvent    *grpcsync.Event
 	state         transportState
 	activeStreams map[uint32]*Stream
 	// idle is the time instant when the connection went idle.
@@ -127,6 +128,8 @@ type http2Server struct {
 	// This lock may not be taken if mu is already held.
 	maxStreamMu sync.Mutex
 	maxStreamID uint32 // max stream ID ever seen
+
+	logger *grpclog.PrefixLogger
 }
 
 // NewServerTransport creates a http2 transport with conn and configuration
@@ -159,21 +162,16 @@ func NewServerTransport(conn net.Conn, config *ServerConfig) (_ ServerTransport,
 	if config.MaxHeaderListSize != nil {
 		maxHeaderListSize = *config.MaxHeaderListSize
 	}
-	framer := newFramer(conn, writeBufSize, readBufSize, maxHeaderListSize)
+	framer := newFramer(conn, writeBufSize, readBufSize, config.SharedWriteBuffer, maxHeaderListSize)
 	// Send initial settings as connection preface to client.
 	isettings := []http2.Setting{{
 		ID:  http2.SettingMaxFrameSize,
 		Val: http2MaxFrameLen,
 	}}
-	// TODO(zhaoq): Have a better way to signal "no limit" because 0 is
-	// permitted in the HTTP2 spec.
-	maxStreams := config.MaxStreams
-	if maxStreams == 0 {
-		maxStreams = math.MaxUint32
-	} else {
+	if config.MaxStreams != math.MaxUint32 {
 		isettings = append(isettings, http2.Setting{
 			ID:  http2.SettingMaxConcurrentStreams,
-			Val: maxStreams,
+			Val: config.MaxStreams,
 		})
 	}
 	dynamicWindow := true
@@ -232,7 +230,7 @@ func NewServerTransport(conn net.Conn, config *ServerConfig) (_ ServerTransport,
 		kp.Timeout = defaultServerKeepaliveTimeout
 	}
 	if kp.Time != infinity {
-		if err = syscall.SetTCPUserTimeout(conn, kp.Timeout); err != nil {
+		if err = syscall.SetTCPUserTimeout(rawConn, kp.Timeout); err != nil {
 			return nil, connectionErrorf(false, err, "transport: failed to set TCP_USER_TIMEOUT: %v", err)
 		}
 	}
@@ -242,17 +240,19 @@ func NewServerTransport(conn net.Conn, config *ServerConfig) (_ ServerTransport,
 	}
 
 	done := make(chan struct{})
+	peer := peer.Peer{
+		Addr:      conn.RemoteAddr(),
+		LocalAddr: conn.LocalAddr(),
+		AuthInfo:  authInfo,
+	}
 	t := &http2Server{
-		ctx:               setConnection(context.Background(), rawConn),
 		done:              done,
 		conn:              conn,
-		remoteAddr:        conn.RemoteAddr(),
-		localAddr:         conn.LocalAddr(),
-		authInfo:          authInfo,
+		peer:              peer,
 		framer:            framer,
 		readerDone:        make(chan struct{}),
-		writerDone:        make(chan struct{}),
-		maxStreams:        maxStreams,
+		loopyWriterDone:   make(chan struct{}),
+		maxStreams:        config.MaxStreams,
 		inTapHandle:       config.InTapHandle,
 		fc:                &trInFlow{limit: uint32(icwz)},
 		state:             reachable,
@@ -265,8 +265,7 @@ func NewServerTransport(conn net.Conn, config *ServerConfig) (_ ServerTransport,
 		czData:            new(channelzData),
 		bufferPool:        newBufferPool(),
 	}
-	// Add peer information to the http2server context.
-	t.ctx = peer.NewContext(t.ctx, t.getPeer())
+	t.logger = prefixLoggerForServerTransport(t)
 
 	t.controlBuf = newControlBuffer(t.done)
 	if dynamicWindow {
@@ -275,15 +274,7 @@ func NewServerTransport(conn net.Conn, config *ServerConfig) (_ ServerTransport,
 			updateFlowControl: t.updateFlowControl,
 		}
 	}
-	for _, sh := range t.stats {
-		t.ctx = sh.TagConn(t.ctx, &stats.ConnTagInfo{
-			RemoteAddr: t.remoteAddr,
-			LocalAddr:  t.localAddr,
-		})
-		connBegin := &stats.ConnBegin{}
-		sh.HandleConn(t.ctx, connBegin)
-	}
-	t.channelzID, err = channelz.RegisterNormalSocket(t, config.ChannelzParentID, fmt.Sprintf("%s -> %s", t.remoteAddr, t.localAddr))
+	t.channelzID, err = channelz.RegisterNormalSocket(t, config.ChannelzParentID, fmt.Sprintf("%s -> %s", t.peer.Addr, t.peer.LocalAddr))
 	if err != nil {
 		return nil, err
 	}
@@ -293,7 +284,7 @@ func NewServerTransport(conn net.Conn, config *ServerConfig) (_ ServerTransport,
 
 	defer func() {
 		if err != nil {
-			t.Close()
+			t.Close(err)
 		}
 	}()
 
@@ -329,23 +320,18 @@ func NewServerTransport(conn net.Conn, config *ServerConfig) (_ ServerTransport,
 	t.handleSettings(sf)
 
 	go func() {
-		t.loopy = newLoopyWriter(serverSide, t.framer, t.controlBuf, t.bdpEst)
+		t.loopy = newLoopyWriter(serverSide, t.framer, t.controlBuf, t.bdpEst, t.conn, t.logger)
 		t.loopy.ssGoAwayHandler = t.outgoingGoAwayHandler
-		if err := t.loopy.run(); err != nil {
-			if logger.V(logLevel) {
-				logger.Errorf("transport: loopyWriter.run returning. Err: %v", err)
-			}
-		}
-		t.conn.Close()
-		t.controlBuf.finish()
-		close(t.writerDone)
+		t.loopy.run()
+		close(t.loopyWriterDone)
 	}()
 	go t.keepalive()
 	return t, nil
 }
 
-// operateHeader takes action on the decoded headers.
-func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(*Stream), traceCtx func(context.Context, string) context.Context) (fatal bool) {
+// operateHeaders takes action on the decoded headers. Returns an error if fatal
+// error encountered and transport needs to close, otherwise returns nil.
+func (t *http2Server) operateHeaders(ctx context.Context, frame *http2.MetaHeadersFrame, handle func(*Stream)) error {
 	// Acquire max stream ID lock for entire duration
 	t.maxStreamMu.Lock()
 	defer t.maxStreamMu.Unlock()
@@ -361,33 +347,32 @@ func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(
 			rstCode:  http2.ErrCodeFrameSize,
 			onWrite:  func() {},
 		})
-		return false
+		return nil
 	}
 
 	if streamID%2 != 1 || streamID <= t.maxStreamID {
 		// illegal gRPC stream id.
-		if logger.V(logLevel) {
-			logger.Errorf("transport: http2Server.HandleStreams received an illegal stream id: %v", streamID)
-		}
-		return true
+		return fmt.Errorf("received an illegal stream id: %v. headers frame: %+v", streamID, frame)
 	}
 	t.maxStreamID = streamID
 
 	buf := newRecvBuffer()
 	s := &Stream{
-		id:  streamID,
-		st:  t,
-		buf: buf,
-		fc:  &inFlow{limit: uint32(t.initialWindowSize)},
+		id:               streamID,
+		st:               t,
+		buf:              buf,
+		fc:               &inFlow{limit: uint32(t.initialWindowSize)},
+		headerWireLength: int(frame.Header().Length),
 	}
 	var (
-		// If a gRPC Response-Headers has already been received, then it means
-		// that the peer is speaking gRPC and we are in gRPC mode.
-		isGRPC     = false
-		mdata      = make(map[string][]string)
-		httpMethod string
-		// headerError is set if an error is encountered while parsing the headers
-		headerError bool
+		// if false, content-type was missing or invalid
+		isGRPC      = false
+		contentType = ""
+		mdata       = make(metadata.MD, len(frame.Fields))
+		httpMethod  string
+		// these are set if an error is encountered while parsing the headers
+		protocolError bool
+		headerError   *status.Status
 
 		timeoutSet bool
 		timeout    time.Duration
@@ -398,11 +383,23 @@ func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(
 		case "content-type":
 			contentSubtype, validContentType := grpcutil.ContentSubtype(hf.Value)
 			if !validContentType {
+				contentType = hf.Value
 				break
 			}
 			mdata[hf.Name] = append(mdata[hf.Name], hf.Value)
 			s.contentSubtype = contentSubtype
 			isGRPC = true
+
+		case "grpc-accept-encoding":
+			mdata[hf.Name] = append(mdata[hf.Name], hf.Value)
+			if hf.Value == "" {
+				continue
+			}
+			compressors := hf.Value
+			if s.clientAdvertisedCompressors != "" {
+				compressors = s.clientAdvertisedCompressors + "," + compressors
+			}
+			s.clientAdvertisedCompressors = compressors
 		case "grpc-encoding":
 			s.recvCompress = hf.Value
 		case ":method":
@@ -413,23 +410,23 @@ func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(
 			timeoutSet = true
 			var err error
 			if timeout, err = decodeTimeout(hf.Value); err != nil {
-				headerError = true
+				headerError = status.Newf(codes.Internal, "malformed grpc-timeout: %v", err)
 			}
 		// "Transports must consider requests containing the Connection header
 		// as malformed." - A41
 		case "connection":
-			if logger.V(logLevel) {
-				logger.Errorf("transport: http2Server.operateHeaders parsed a :connection header which makes a request malformed as per the HTTP/2 spec")
+			if t.logger.V(logLevel) {
+				t.logger.Infof("Received a HEADERS frame with a :connection header which makes the request malformed, as per the HTTP/2 spec")
 			}
-			headerError = true
+			protocolError = true
 		default:
 			if isReservedHeader(hf.Name) && !isWhitelistedHeader(hf.Name) {
 				break
 			}
 			v, err := decodeMetadataHeader(hf.Name, hf.Value)
 			if err != nil {
-				headerError = true
-				logger.Warningf("Failed to decode metadata header (%q, %q): %v", hf.Name, hf.Value, err)
+				headerError = status.Newf(codes.Internal, "malformed binary metadata %q in header %q: %v", hf.Value, hf.Name, err)
+				t.logger.Warningf("Failed to decode metadata header (%q, %q): %v", hf.Name, hf.Value, err)
 				break
 			}
 			mdata[hf.Name] = append(mdata[hf.Name], v)
@@ -443,27 +440,47 @@ func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(
 	// error, this takes precedence over a client not speaking gRPC.
 	if len(mdata[":authority"]) > 1 || len(mdata["host"]) > 1 {
 		errMsg := fmt.Sprintf("num values of :authority: %v, num values of host: %v, both must only have 1 value as per HTTP/2 spec", len(mdata[":authority"]), len(mdata["host"]))
-		if logger.V(logLevel) {
-			logger.Errorf("transport: %v", errMsg)
+		if t.logger.V(logLevel) {
+			t.logger.Infof("Aborting the stream early: %v", errMsg)
 		}
 		t.controlBuf.put(&earlyAbortStream{
-			httpStatus:     400,
+			httpStatus:     http.StatusBadRequest,
 			streamID:       streamID,
 			contentSubtype: s.contentSubtype,
 			status:         status.New(codes.Internal, errMsg),
 			rst:            !frame.StreamEnded(),
 		})
-		return false
+		return nil
 	}
 
-	if !isGRPC || headerError {
+	if protocolError {
 		t.controlBuf.put(&cleanupStream{
 			streamID: streamID,
 			rst:      true,
 			rstCode:  http2.ErrCodeProtocol,
 			onWrite:  func() {},
 		})
-		return false
+		return nil
+	}
+	if !isGRPC {
+		t.controlBuf.put(&earlyAbortStream{
+			httpStatus:     http.StatusUnsupportedMediaType,
+			streamID:       streamID,
+			contentSubtype: s.contentSubtype,
+			status:         status.Newf(codes.InvalidArgument, "invalid gRPC request content-type %q", contentType),
+			rst:            !frame.StreamEnded(),
+		})
+		return nil
+	}
+	if headerError != nil {
+		t.controlBuf.put(&earlyAbortStream{
+			httpStatus:     http.StatusBadRequest,
+			streamID:       streamID,
+			contentSubtype: s.contentSubtype,
+			status:         headerError,
+			rst:            !frame.StreamEnded(),
+		})
+		return nil
 	}
 
 	// "If :authority is missing, Host must be renamed to :authority." - A41
@@ -484,9 +501,9 @@ func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(
 		s.state = streamReadDone
 	}
 	if timeoutSet {
-		s.ctx, s.cancel = context.WithTimeout(t.ctx, timeout)
+		s.ctx, s.cancel = context.WithTimeout(ctx, timeout)
 	} else {
-		s.ctx, s.cancel = context.WithCancel(t.ctx)
+		s.ctx, s.cancel = context.WithCancel(ctx)
 	}
 
 	// Attach the received metadata to the context.
@@ -503,7 +520,7 @@ func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(
 	if t.state != reachable {
 		t.mu.Unlock()
 		s.cancel()
-		return false
+		return nil
 	}
 	if uint32(len(t.activeStreams)) >= t.maxStreams {
 		t.mu.Unlock()
@@ -514,13 +531,13 @@ func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(
 			onWrite:  func() {},
 		})
 		s.cancel()
-		return false
+		return nil
 	}
 	if httpMethod != http.MethodPost {
 		t.mu.Unlock()
-		errMsg := fmt.Sprintf("http2Server.operateHeaders parsed a :method field: %v which should be POST", httpMethod)
-		if logger.V(logLevel) {
-			logger.Infof("transport: %v", errMsg)
+		errMsg := fmt.Sprintf("Received a HEADERS frame with :method %q which should be POST", httpMethod)
+		if t.logger.V(logLevel) {
+			t.logger.Infof("Aborting the stream early: %v", errMsg)
 		}
 		t.controlBuf.put(&earlyAbortStream{
 			httpStatus:     405,
@@ -530,14 +547,14 @@ func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(
 			rst:            !frame.StreamEnded(),
 		})
 		s.cancel()
-		return false
+		return nil
 	}
 	if t.inTapHandle != nil {
 		var err error
-		if s.ctx, err = t.inTapHandle(s.ctx, &tap.Info{FullMethodName: s.method}); err != nil {
+		if s.ctx, err = t.inTapHandle(s.ctx, &tap.Info{FullMethodName: s.method, Header: mdata}); err != nil {
 			t.mu.Unlock()
-			if logger.V(logLevel) {
-				logger.Infof("transport: http2Server.operateHeaders got an error from InTapHandle: %v", err)
+			if t.logger.V(logLevel) {
+				t.logger.Infof("Aborting the stream early due to InTapHandle failure: %v", err)
 			}
 			stat, ok := status.FromError(err)
 			if !ok {
@@ -550,7 +567,7 @@ func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(
 				status:         stat,
 				rst:            !frame.StreamEnded(),
 			})
-			return false
+			return nil
 		}
 	}
 	t.activeStreams[streamID] = s
@@ -565,19 +582,6 @@ func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(
 	s.requestRead = func(n int) {
 		t.adjustWindow(s, uint32(n))
 	}
-	s.ctx = traceCtx(s.ctx, s.method)
-	for _, sh := range t.stats {
-		s.ctx = sh.TagRPC(s.ctx, &stats.RPCTagInfo{FullMethodName: s.method})
-		inHeader := &stats.InHeader{
-			FullMethod:  s.method,
-			RemoteAddr:  t.remoteAddr,
-			LocalAddr:   t.localAddr,
-			Compression: s.recvCompress,
-			WireLength:  int(frame.Header().Length),
-			Header:      metadata.MD(mdata).Copy(),
-		}
-		sh.HandleRPC(s.ctx, inHeader)
-	}
 	s.ctxDone = s.ctx.Done()
 	s.wq = newWriteQuota(defaultWriteQuota, s.ctxDone)
 	s.trReader = &transportReader{
@@ -597,22 +601,25 @@ func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(
 		wq:       s.wq,
 	})
 	handle(s)
-	return false
+	return nil
 }
 
 // HandleStreams receives incoming streams using the given handler. This is
 // typically run in a separate goroutine.
 // traceCtx attaches trace to ctx and returns the new context.
-func (t *http2Server) HandleStreams(handle func(*Stream), traceCtx func(context.Context, string) context.Context) {
-	defer close(t.readerDone)
+func (t *http2Server) HandleStreams(ctx context.Context, handle func(*Stream)) {
+	defer func() {
+		<-t.loopyWriterDone
+		close(t.readerDone)
+	}()
 	for {
 		t.controlBuf.throttle()
 		frame, err := t.framer.fr.ReadFrame()
 		atomic.StoreInt64(&t.lastRead, time.Now().UnixNano())
 		if err != nil {
 			if se, ok := err.(http2.StreamError); ok {
-				if logger.V(logLevel) {
-					logger.Warningf("transport: http2Server.HandleStreams encountered http2.StreamError: %v", se)
+				if t.logger.V(logLevel) {
+					t.logger.Warningf("Encountered http2.StreamError: %v", se)
 				}
 				t.mu.Lock()
 				s := t.activeStreams[se.StreamID]
@@ -630,19 +637,16 @@ func (t *http2Server) HandleStreams(handle func(*Stream), traceCtx func(context.
 				continue
 			}
 			if err == io.EOF || err == io.ErrUnexpectedEOF {
-				t.Close()
+				t.Close(err)
 				return
 			}
-			if logger.V(logLevel) {
-				logger.Warningf("transport: http2Server.HandleStreams failed to read frame: %v", err)
-			}
-			t.Close()
+			t.Close(err)
 			return
 		}
 		switch frame := frame.(type) {
 		case *http2.MetaHeadersFrame:
-			if t.operateHeaders(frame, handle, traceCtx) {
-				t.Close()
+			if err := t.operateHeaders(ctx, frame, handle); err != nil {
+				t.Close(err)
 				break
 			}
 		case *http2.DataFrame:
@@ -658,8 +662,8 @@ func (t *http2Server) HandleStreams(handle func(*Stream), traceCtx func(context.
 		case *http2.GoAwayFrame:
 			// TODO: Handle GoAway from the client appropriately.
 		default:
-			if logger.V(logLevel) {
-				logger.Errorf("transport: http2Server.HandleStreams found unhandled frame type %v.", frame)
+			if t.logger.V(logLevel) {
+				t.logger.Infof("Received unsupported frame type %T", frame)
 			}
 		}
 	}
@@ -826,7 +830,7 @@ func (t *http2Server) handleSettings(f *http2.SettingsFrame) {
 		}
 		return nil
 	})
-	t.controlBuf.executeAndPut(func(interface{}) bool {
+	t.controlBuf.executeAndPut(func(any) bool {
 		for _, f := range updateFuncs {
 			f()
 		}
@@ -843,8 +847,8 @@ const (
 
 func (t *http2Server) handlePing(f *http2.PingFrame) {
 	if f.IsAck() {
-		if f.Data == goAwayPing.data && t.drainChan != nil {
-			close(t.drainChan)
+		if f.Data == goAwayPing.data && t.drainEvent != nil {
+			t.drainEvent.Fire()
 			return
 		}
 		// Maybe it's a BDP ping.
@@ -886,10 +890,7 @@ func (t *http2Server) handlePing(f *http2.PingFrame) {
 
 	if t.pingStrikes > maxPingStrikes {
 		// Send goaway and close the connection.
-		if logger.V(logLevel) {
-			logger.Errorf("transport: Got too many pings from the client, closing the connection.")
-		}
-		t.controlBuf.put(&goAway{code: http2.ErrCodeEnhanceYourCalm, debugData: []byte("too_many_pings"), closeConn: true})
+		t.controlBuf.put(&goAway{code: http2.ErrCodeEnhanceYourCalm, debugData: []byte("too_many_pings"), closeConn: errors.New("got too many pings from the client")})
 	}
 }
 
@@ -913,7 +914,7 @@ func appendHeaderFieldsFromMD(headerFields []hpack.HeaderField, md metadata.MD)
 	return headerFields
 }
 
-func (t *http2Server) checkForHeaderListSize(it interface{}) bool {
+func (t *http2Server) checkForHeaderListSize(it any) bool {
 	if t.maxSendHeaderListSize == nil {
 		return true
 	}
@@ -921,8 +922,8 @@ func (t *http2Server) checkForHeaderListSize(it interface{}) bool {
 	var sz int64
 	for _, f := range hdrFrame.hf {
 		if sz += int64(f.Size()); sz > int64(*t.maxSendHeaderListSize) {
-			if logger.V(logLevel) {
-				logger.Errorf("header list size to send violates the maximum size (%d bytes) set by client", *t.maxSendHeaderListSize)
+			if t.logger.V(logLevel) {
+				t.logger.Infof("Header list size to send violates the maximum size (%d bytes) set by client", *t.maxSendHeaderListSize)
 			}
 			return false
 		}
@@ -1032,12 +1033,15 @@ func (t *http2Server) WriteStatus(s *Stream, st *status.Status) error {
 	headerFields = append(headerFields, hpack.HeaderField{Name: "grpc-message", Value: encodeGrpcMessage(st.Message())})
 
 	if p := st.Proto(); p != nil && len(p.Details) > 0 {
+		// Do not use the user's grpc-status-details-bin (if present) if we are
+		// even attempting to set our own.
+		delete(s.trailer, grpcStatusDetailsBinHeader)
 		stBytes, err := proto.Marshal(p)
 		if err != nil {
 			// TODO: return error instead, when callers are able to handle it.
-			logger.Errorf("transport: failed to marshal rpc status: %v, error: %v", p, err)
+			t.logger.Errorf("Failed to marshal rpc status: %s, error: %v", pretty.ToJSON(p), err)
 		} else {
-			headerFields = append(headerFields, hpack.HeaderField{Name: "grpc-status-details-bin", Value: encodeBinHeader(stBytes)})
+			headerFields = append(headerFields, hpack.HeaderField{Name: grpcStatusDetailsBinHeader, Value: encodeBinHeader(stBytes)})
 		}
 	}
 
@@ -1140,20 +1144,20 @@ func (t *http2Server) keepalive() {
 			if val <= 0 {
 				// The connection has been idle for a duration of keepalive.MaxConnectionIdle or more.
 				// Gracefully close the connection.
-				t.Drain()
+				t.Drain("max_idle")
 				return
 			}
 			idleTimer.Reset(val)
 		case <-ageTimer.C:
-			t.Drain()
+			t.Drain("max_age")
 			ageTimer.Reset(t.kp.MaxConnectionAgeGrace)
 			select {
 			case <-ageTimer.C:
 				// Close the connection after grace period.
-				if logger.V(logLevel) {
-					logger.Infof("transport: closing server transport due to maximum connection age.")
+				if t.logger.V(logLevel) {
+					t.logger.Infof("Closing server transport due to maximum connection age")
 				}
-				t.Close()
+				t.controlBuf.put(closeConnection{})
 			case <-t.done:
 			}
 			return
@@ -1169,10 +1173,7 @@ func (t *http2Server) keepalive() {
 				continue
 			}
 			if outstandingPing && kpTimeoutLeft <= 0 {
-				if logger.V(logLevel) {
-					logger.Infof("transport: closing server transport due to idleness.")
-				}
-				t.Close()
+				t.Close(fmt.Errorf("keepalive ping not acked within timeout %s", t.kp.Time))
 				return
 			}
 			if !outstandingPing {
@@ -1199,30 +1200,29 @@ func (t *http2Server) keepalive() {
 // Close starts shutting down the http2Server transport.
 // TODO(zhaoq): Now the destruction is not blocked on any pending streams. This
 // could cause some resource issue. Revisit this later.
-func (t *http2Server) Close() {
+func (t *http2Server) Close(err error) {
 	t.mu.Lock()
 	if t.state == closing {
 		t.mu.Unlock()
 		return
 	}
+	if t.logger.V(logLevel) {
+		t.logger.Infof("Closing: %v", err)
+	}
 	t.state = closing
 	streams := t.activeStreams
 	t.activeStreams = nil
 	t.mu.Unlock()
 	t.controlBuf.finish()
 	close(t.done)
-	if err := t.conn.Close(); err != nil && logger.V(logLevel) {
-		logger.Infof("transport: error closing conn during Close: %v", err)
+	if err := t.conn.Close(); err != nil && t.logger.V(logLevel) {
+		t.logger.Infof("Error closing underlying net.Conn during Close: %v", err)
 	}
 	channelz.RemoveEntry(t.channelzID)
 	// Cancel all active streams.
 	for _, s := range streams {
 		s.cancel()
 	}
-	for _, sh := range t.stats {
-		connEnd := &stats.ConnEnd{}
-		sh.HandleConn(t.ctx, connEnd)
-	}
 }
 
 // deleteStream deletes the stream s from transport's active streams.
@@ -1288,18 +1288,14 @@ func (t *http2Server) closeStream(s *Stream, rst bool, rstCode http2.ErrCode, eo
 	})
 }
 
-func (t *http2Server) RemoteAddr() net.Addr {
-	return t.remoteAddr
-}
-
-func (t *http2Server) Drain() {
+func (t *http2Server) Drain(debugData string) {
 	t.mu.Lock()
 	defer t.mu.Unlock()
-	if t.drainChan != nil {
+	if t.drainEvent != nil {
 		return
 	}
-	t.drainChan = make(chan struct{})
-	t.controlBuf.put(&goAway{code: http2.ErrCodeNo, debugData: []byte{}, headsUp: true})
+	t.drainEvent = grpcsync.NewEvent()
+	t.controlBuf.put(&goAway{code: http2.ErrCodeNo, debugData: []byte(debugData), headsUp: true})
 }
 
 var goAwayPing = &ping{data: [8]byte{1, 6, 1, 8, 0, 3, 3, 9}}
@@ -1319,19 +1315,17 @@ func (t *http2Server) outgoingGoAwayHandler(g *goAway) (bool, error) {
 		// Stop accepting more streams now.
 		t.state = draining
 		sid := t.maxStreamID
+		retErr := g.closeConn
 		if len(t.activeStreams) == 0 {
-			g.closeConn = true
+			retErr = errors.New("second GOAWAY written and no active streams left to process")
 		}
 		t.mu.Unlock()
 		t.maxStreamMu.Unlock()
 		if err := t.framer.fr.WriteGoAway(sid, g.code, g.debugData); err != nil {
 			return false, err
 		}
-		if g.closeConn {
-			// Abruptly close the connection following the GoAway (via
-			// loopywriter).  But flush out what's inside the buffer first.
-			t.framer.writer.Flush()
-			return false, fmt.Errorf("transport: Connection closing")
+		if retErr != nil {
+			return false, retErr
 		}
 		return true, nil
 	}
@@ -1343,7 +1337,7 @@ func (t *http2Server) outgoingGoAwayHandler(g *goAway) (bool, error) {
 	// originated before the GoAway reaches the client.
 	// After getting the ack or timer expiration send out another GoAway this
 	// time with an ID of the max stream server intends to process.
-	if err := t.framer.fr.WriteGoAway(math.MaxUint32, http2.ErrCodeNo, []byte{}); err != nil {
+	if err := t.framer.fr.WriteGoAway(math.MaxUint32, http2.ErrCodeNo, g.debugData); err != nil {
 		return false, err
 	}
 	if err := t.framer.fr.WritePing(false, goAwayPing.data); err != nil {
@@ -1353,7 +1347,7 @@ func (t *http2Server) outgoingGoAwayHandler(g *goAway) (bool, error) {
 		timer := time.NewTimer(time.Minute)
 		defer timer.Stop()
 		select {
-		case <-t.drainChan:
+		case <-t.drainEvent.Done():
 		case <-timer.C:
 		case <-t.done:
 			return
@@ -1376,11 +1370,11 @@ func (t *http2Server) ChannelzMetric() *channelz.SocketInternalMetric {
 		LastMessageReceivedTimestamp:     time.Unix(0, atomic.LoadInt64(&t.czData.lastMsgRecvTime)),
 		LocalFlowControlWindow:           int64(t.fc.getSize()),
 		SocketOptions:                    channelz.GetSocketOption(t.conn),
-		LocalAddr:                        t.localAddr,
-		RemoteAddr:                       t.remoteAddr,
+		LocalAddr:                        t.peer.LocalAddr,
+		RemoteAddr:                       t.peer.Addr,
 		// RemoteName :
 	}
-	if au, ok := t.authInfo.(credentials.ChannelzSecurityInfo); ok {
+	if au, ok := t.peer.AuthInfo.(credentials.ChannelzSecurityInfo); ok {
 		s.Security = au.GetSecurityValue()
 	}
 	s.RemoteFlowControlWindow = t.getOutFlowWindow()
@@ -1412,10 +1406,12 @@ func (t *http2Server) getOutFlowWindow() int64 {
 	}
 }
 
-func (t *http2Server) getPeer() *peer.Peer {
+// Peer returns the peer of the transport.
+func (t *http2Server) Peer() *peer.Peer {
 	return &peer.Peer{
-		Addr:     t.remoteAddr,
-		AuthInfo: t.authInfo, // Can be nil
+		Addr:      t.peer.Addr,
+		LocalAddr: t.peer.LocalAddr,
+		AuthInfo:  t.peer.AuthInfo, // Can be nil
 	}
 }
 
@@ -1440,6 +1436,6 @@ func GetConnection(ctx context.Context) net.Conn {
 // SetConnection adds the connection to the context to be able to get
 // information about the destination ip and port for an incoming RPC. This also
 // allows any unary or streaming interceptors to see the connection.
-func setConnection(ctx context.Context, conn net.Conn) context.Context {
+func SetConnection(ctx context.Context, conn net.Conn) context.Context {
 	return context.WithValue(ctx, connectionKey{}, conn)
 }

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

@@ -21,6 +21,7 @@ package transport
 import (
 	"bufio"
 	"encoding/base64"
+	"errors"
 	"fmt"
 	"io"
 	"math"
@@ -29,16 +30,13 @@ import (
 	"net/url"
 	"strconv"
 	"strings"
+	"sync"
 	"time"
 	"unicode/utf8"
 
-	"github.com/golang/protobuf/proto"
 	"golang.org/x/net/http2"
 	"golang.org/x/net/http2/hpack"
-	spb "google.golang.org/genproto/googleapis/rpc/status"
 	"google.golang.org/grpc/codes"
-	"google.golang.org/grpc/grpclog"
-	"google.golang.org/grpc/status"
 )
 
 const (
@@ -85,9 +83,10 @@ var (
 		// 504 Gateway timeout - UNAVAILABLE.
 		http.StatusGatewayTimeout: codes.Unavailable,
 	}
-	logger = grpclog.Component("transport")
 )
 
+var grpcStatusDetailsBinHeader = "grpc-status-details-bin"
+
 // isReservedHeader checks whether hdr belongs to HTTP2 headers
 // reserved by gRPC protocol. Any other headers are classified as the
 // user-specified metadata.
@@ -103,7 +102,6 @@ func isReservedHeader(hdr string) bool {
 		"grpc-message",
 		"grpc-status",
 		"grpc-timeout",
-		"grpc-status-details-bin",
 		// Intentionally exclude grpc-previous-rpc-attempts and
 		// grpc-retry-pushback-ms, which are "reserved", but their API
 		// intentionally works via metadata.
@@ -154,18 +152,6 @@ func decodeMetadataHeader(k, v string) (string, error) {
 	return v, nil
 }
 
-func decodeGRPCStatusDetails(rawDetails string) (*status.Status, error) {
-	v, err := decodeBinHeader(rawDetails)
-	if err != nil {
-		return nil, err
-	}
-	st := &spb.Status{}
-	if err = proto.Unmarshal(v, st); err != nil {
-		return nil, err
-	}
-	return status.FromProto(st), nil
-}
-
 type timeoutUnit uint8
 
 const (
@@ -310,6 +296,7 @@ func decodeGrpcMessageUnchecked(msg string) string {
 }
 
 type bufWriter struct {
+	pool      *sync.Pool
 	buf       []byte
 	offset    int
 	batchSize int
@@ -317,12 +304,17 @@ type bufWriter struct {
 	err       error
 }
 
-func newBufWriter(conn net.Conn, batchSize int) *bufWriter {
-	return &bufWriter{
-		buf:       make([]byte, batchSize*2),
+func newBufWriter(conn net.Conn, batchSize int, pool *sync.Pool) *bufWriter {
+	w := &bufWriter{
 		batchSize: batchSize,
 		conn:      conn,
+		pool:      pool,
 	}
+	// this indicates that we should use non shared buf
+	if pool == nil {
+		w.buf = make([]byte, batchSize)
+	}
+	return w
 }
 
 func (w *bufWriter) Write(b []byte) (n int, err error) {
@@ -330,7 +322,12 @@ func (w *bufWriter) Write(b []byte) (n int, err error) {
 		return 0, w.err
 	}
 	if w.batchSize == 0 { // Buffer has been disabled.
-		return w.conn.Write(b)
+		n, err = w.conn.Write(b)
+		return n, toIOError(err)
+	}
+	if w.buf == nil {
+		b := w.pool.Get().(*[]byte)
+		w.buf = *b
 	}
 	for len(b) > 0 {
 		nn := copy(w.buf[w.offset:], b)
@@ -338,13 +335,24 @@ func (w *bufWriter) Write(b []byte) (n int, err error) {
 		w.offset += nn
 		n += nn
 		if w.offset >= w.batchSize {
-			err = w.Flush()
+			err = w.flushKeepBuffer()
 		}
 	}
 	return n, err
 }
 
 func (w *bufWriter) Flush() error {
+	err := w.flushKeepBuffer()
+	// Only release the buffer if we are in a "shared" mode
+	if w.buf != nil && w.pool != nil {
+		b := w.buf
+		w.pool.Put(&b)
+		w.buf = nil
+	}
+	return err
+}
+
+func (w *bufWriter) flushKeepBuffer() error {
 	if w.err != nil {
 		return w.err
 	}
@@ -352,16 +360,39 @@ func (w *bufWriter) Flush() error {
 		return nil
 	}
 	_, w.err = w.conn.Write(w.buf[:w.offset])
+	w.err = toIOError(w.err)
 	w.offset = 0
 	return w.err
 }
 
+type ioError struct {
+	error
+}
+
+func (i ioError) Unwrap() error {
+	return i.error
+}
+
+func isIOError(err error) bool {
+	return errors.As(err, &ioError{})
+}
+
+func toIOError(err error) error {
+	if err == nil {
+		return nil
+	}
+	return ioError{error: err}
+}
+
 type framer struct {
 	writer *bufWriter
 	fr     *http2.Framer
 }
 
-func newFramer(conn net.Conn, writeBufferSize, readBufferSize int, maxHeaderListSize uint32) *framer {
+var writeBufferPoolMap map[int]*sync.Pool = make(map[int]*sync.Pool)
+var writeBufferMutex sync.Mutex
+
+func newFramer(conn net.Conn, writeBufferSize, readBufferSize int, sharedWriteBuffer bool, maxHeaderListSize uint32) *framer {
 	if writeBufferSize < 0 {
 		writeBufferSize = 0
 	}
@@ -369,7 +400,11 @@ func newFramer(conn net.Conn, writeBufferSize, readBufferSize int, maxHeaderList
 	if readBufferSize > 0 {
 		r = bufio.NewReaderSize(r, readBufferSize)
 	}
-	w := newBufWriter(conn, writeBufferSize)
+	var pool *sync.Pool
+	if sharedWriteBuffer {
+		pool = getWriteBufferPool(writeBufferSize)
+	}
+	w := newBufWriter(conn, writeBufferSize, pool)
 	f := &framer{
 		writer: w,
 		fr:     http2.NewFramer(w, r),
@@ -383,6 +418,24 @@ func newFramer(conn net.Conn, writeBufferSize, readBufferSize int, maxHeaderList
 	return f
 }
 
+func getWriteBufferPool(writeBufferSize int) *sync.Pool {
+	writeBufferMutex.Lock()
+	defer writeBufferMutex.Unlock()
+	size := writeBufferSize * 2
+	pool, ok := writeBufferPoolMap[size]
+	if ok {
+		return pool
+	}
+	pool = &sync.Pool{
+		New: func() any {
+			b := make([]byte, size)
+			return &b
+		},
+	}
+	writeBufferPoolMap[size] = pool
+	return pool
+}
+
 // parseDialTarget returns the network and address to pass to dialer.
 func parseDialTarget(target string) (string, string) {
 	net := "tcp"

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

@@ -0,0 +1,40 @@
+/*
+ *
+ * Copyright 2023 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 transport
+
+import (
+	"fmt"
+
+	"google.golang.org/grpc/grpclog"
+	internalgrpclog "google.golang.org/grpc/internal/grpclog"
+)
+
+var logger = grpclog.Component("transport")
+
+func prefixLoggerForServerTransport(p *http2Server) *internalgrpclog.PrefixLogger {
+	return internalgrpclog.NewPrefixLogger(logger, fmt.Sprintf("[server-transport %p] ", p))
+}
+
+func prefixLoggerForServerHandlerTransport(p *serverHandlerTransport) *internalgrpclog.PrefixLogger {
+	return internalgrpclog.NewPrefixLogger(logger, fmt.Sprintf("[server-handler-transport %p] ", p))
+}
+
+func prefixLoggerForClientTransport(p *http2Client) *internalgrpclog.PrefixLogger {
+	return internalgrpclog.NewPrefixLogger(logger, fmt.Sprintf("[client-transport %p] ", p))
+}

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

@@ -28,6 +28,8 @@ import (
 	"net/http"
 	"net/http/httputil"
 	"net/url"
+
+	"google.golang.org/grpc/internal"
 )
 
 const proxyAuthHeaderKey = "Proxy-Authorization"
@@ -112,7 +114,7 @@ func doHTTPConnectHandshake(ctx context.Context, conn net.Conn, backendAddr stri
 // proxyDial dials, connecting to a proxy first if necessary. Checks if a proxy
 // is necessary, dials, does the HTTP CONNECT handshake, and returns the
 // connection.
-func proxyDial(ctx context.Context, addr string, grpcUA string) (conn net.Conn, err error) {
+func proxyDial(ctx context.Context, addr string, grpcUA string) (net.Conn, error) {
 	newAddr := addr
 	proxyURL, err := mapAddress(addr)
 	if err != nil {
@@ -122,15 +124,15 @@ func proxyDial(ctx context.Context, addr string, grpcUA string) (conn net.Conn,
 		newAddr = proxyURL.Host
 	}
 
-	conn, err = (&net.Dialer{}).DialContext(ctx, "tcp", newAddr)
+	conn, err := internal.NetDialerWithTCPKeepalive().DialContext(ctx, "tcp", newAddr)
 	if err != nil {
-		return
+		return nil, err
 	}
-	if proxyURL != nil {
+	if proxyURL == nil {
 		// proxy is disabled if proxyURL is nil.
-		conn, err = doHTTPConnectHandshake(ctx, conn, addr, proxyURL, grpcUA)
+		return conn, err
 	}
-	return
+	return doHTTPConnectHandshake(ctx, conn, addr, proxyURL, grpcUA)
 }
 
 func sendHTTPRequest(ctx context.Context, req *http.Request, conn net.Conn) error {

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

@@ -37,16 +37,13 @@ import (
 	"google.golang.org/grpc/internal/channelz"
 	"google.golang.org/grpc/keepalive"
 	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/peer"
 	"google.golang.org/grpc/resolver"
 	"google.golang.org/grpc/stats"
 	"google.golang.org/grpc/status"
 	"google.golang.org/grpc/tap"
 )
 
-// ErrNoHeaders is used as a signal that a trailers only response was received,
-// and is not a real error.
-var ErrNoHeaders = errors.New("stream has no headers")
-
 const logLevel = 2
 
 type bufferPool struct {
@@ -56,7 +53,7 @@ type bufferPool struct {
 func newBufferPool() *bufferPool {
 	return &bufferPool{
 		pool: sync.Pool{
-			New: func() interface{} {
+			New: func() any {
 				return new(bytes.Buffer)
 			},
 		},
@@ -257,6 +254,9 @@ type Stream struct {
 	fc           *inFlow
 	wq           *writeQuota
 
+	// Holds compressor names passed in grpc-accept-encoding metadata from the
+	// client. This is empty for the client side stream.
+	clientAdvertisedCompressors string
 	// Callback to state application's intentions to read data. This
 	// is used to adjust flow control, if needed.
 	requestRead func(int)
@@ -266,7 +266,8 @@ type Stream struct {
 	// headerValid indicates whether a valid header was received.  Only
 	// meaningful after headerChan is closed (always call waitOnHeader() before
 	// reading its value).  Not valid on server side.
-	headerValid bool
+	headerValid      bool
+	headerWireLength int // Only set on server side.
 
 	// hdrMu protects header and trailer metadata on the server-side.
 	hdrMu sync.Mutex
@@ -345,8 +346,24 @@ func (s *Stream) RecvCompress() string {
 }
 
 // SetSendCompress sets the compression algorithm to the stream.
-func (s *Stream) SetSendCompress(str string) {
-	s.sendCompress = str
+func (s *Stream) SetSendCompress(name string) error {
+	if s.isHeaderSent() || s.getState() == streamDone {
+		return errors.New("transport: set send compressor called after headers sent or stream done")
+	}
+
+	s.sendCompress = name
+	return nil
+}
+
+// SendCompress returns the send compressor name.
+func (s *Stream) SendCompress() string {
+	return s.sendCompress
+}
+
+// ClientAdvertisedCompressors returns the compressor names advertised by the
+// client via grpc-accept-encoding header.
+func (s *Stream) ClientAdvertisedCompressors() string {
+	return s.clientAdvertisedCompressors
 }
 
 // Done returns a channel which is closed when it receives the final status
@@ -371,14 +388,10 @@ func (s *Stream) Header() (metadata.MD, error) {
 	}
 	s.waitOnHeader()
 
-	if !s.headerValid {
+	if !s.headerValid || s.noHeaders {
 		return nil, s.status.Err()
 	}
 
-	if s.noHeaders {
-		return nil, ErrNoHeaders
-	}
-
 	return s.header.Copy(), nil
 }
 
@@ -414,6 +427,12 @@ func (s *Stream) Context() context.Context {
 	return s.ctx
 }
 
+// SetContext sets the context of the stream. This will be deleted once the
+// stats handler callouts all move to gRPC layer.
+func (s *Stream) SetContext(ctx context.Context) {
+	s.ctx = ctx
+}
+
 // Method returns the method for the stream.
 func (s *Stream) Method() string {
 	return s.method
@@ -426,6 +445,12 @@ func (s *Stream) Status() *status.Status {
 	return s.status
 }
 
+// HeaderWireLength returns the size of the headers of the stream as received
+// from the wire. Valid only on the server.
+func (s *Stream) HeaderWireLength() int {
+	return s.headerWireLength
+}
+
 // SetHeader sets the header metadata. This can be called multiple times.
 // Server side only.
 // This should not be called in parallel to other data writes.
@@ -540,6 +565,7 @@ type ServerConfig struct {
 	InitialConnWindowSize int32
 	WriteBufferSize       int
 	ReadBufferSize        int
+	SharedWriteBuffer     bool
 	ChannelzParentID      *channelz.Identifier
 	MaxHeaderListSize     *uint32
 	HeaderTableSize       *uint32
@@ -573,6 +599,8 @@ type ConnectOptions struct {
 	WriteBufferSize int
 	// ReadBufferSize sets the size of read buffer, which in turn determines how much data can be read at most for one read syscall.
 	ReadBufferSize int
+	// SharedWriteBuffer indicates whether connections should reuse write buffer
+	SharedWriteBuffer bool
 	// ChannelzParentID sets the addrConn id which initiate the creation of this client transport.
 	ChannelzParentID *channelz.Identifier
 	// MaxHeaderListSize sets the max (uncompressed) size of header list that is prepared to be received.
@@ -583,8 +611,8 @@ type ConnectOptions struct {
 
 // NewClientTransport establishes the transport with the required ConnectOptions
 // and returns it to the caller.
-func NewClientTransport(connectCtx, ctx context.Context, addr resolver.Address, opts ConnectOptions, onGoAway func(GoAwayReason), onClose func()) (ClientTransport, error) {
-	return newHTTP2Client(connectCtx, ctx, addr, opts, onGoAway, onClose)
+func NewClientTransport(connectCtx, ctx context.Context, addr resolver.Address, opts ConnectOptions, onClose func(GoAwayReason)) (ClientTransport, error) {
+	return newHTTP2Client(connectCtx, ctx, addr, opts, onClose)
 }
 
 // Options provides additional hints and information for message
@@ -684,7 +712,7 @@ type ClientTransport interface {
 // Write methods for a given Stream will be called serially.
 type ServerTransport interface {
 	// HandleStreams receives incoming streams using the given handler.
-	HandleStreams(func(*Stream), func(context.Context, string) context.Context)
+	HandleStreams(context.Context, func(*Stream))
 
 	// WriteHeader sends the header metadata for the given stream.
 	// WriteHeader may not be called on all streams.
@@ -701,13 +729,13 @@ type ServerTransport interface {
 	// Close tears down the transport. Once it is called, the transport
 	// should not be accessed any more. All the pending streams and their
 	// handlers will be terminated asynchronously.
-	Close()
+	Close(err error)
 
-	// RemoteAddr returns the remote network address.
-	RemoteAddr() net.Addr
+	// Peer returns the peer of the server transport.
+	Peer() *peer.Peer
 
 	// Drain notifies the client this ServerTransport stops accepting new RPCs.
-	Drain()
+	Drain(debugData string)
 
 	// IncrMsgSent increments the number of message sent through this transport.
 	IncrMsgSent()
@@ -717,7 +745,7 @@ type ServerTransport interface {
 }
 
 // connectionErrorf creates an ConnectionError with the specified error description.
-func connectionErrorf(temp bool, e error, format string, a ...interface{}) ConnectionError {
+func connectionErrorf(temp bool, e error, format string, a ...any) ConnectionError {
 	return ConnectionError{
 		Desc: fmt.Sprintf(format, a...),
 		temp: temp,