Update module google.golang.org/grpc to v1.81.0

Signed-off-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

go.mod

@@ -72,7 +72,7 @@ require (
 	golang.org/x/sync v0.20.0
 	golang.org/x/sys v0.43.0
 	golang.org/x/term v0.42.0
-	google.golang.org/grpc v1.80.0
+	google.golang.org/grpc v1.81.0
 	google.golang.org/protobuf v1.36.11
 	gopkg.in/inf.v0 v0.9.1
 	gopkg.in/yaml.v3 v3.0.1

go.sum

@@ -560,8 +560,8 @@ google.golang.org/genproto/googleapis/api v0.0.0-20260401024825-9d38bb4040a9 h1:
 google.golang.org/genproto/googleapis/api v0.0.0-20260401024825-9d38bb4040a9/go.mod h1:7QBABkRtR8z+TEnmXTqIqwJLlzrZKVfAUm7tY3yGv0M=
 google.golang.org/genproto/googleapis/rpc v0.0.0-20260401024825-9d38bb4040a9 h1:m8qni9SQFH0tJc1X0vmnpw/0t+AImlSvp30sEupozUg=
 google.golang.org/genproto/googleapis/rpc v0.0.0-20260401024825-9d38bb4040a9/go.mod h1:4Hqkh8ycfw05ld/3BWL7rJOSfebL2Q+DVDeRgYgxUU8=
-google.golang.org/grpc v1.80.0 h1:Xr6m2WmWZLETvUNvIUmeD5OAagMw3FiKmMlTdViWsHM=
-google.golang.org/grpc v1.80.0/go.mod h1:ho/dLnxwi3EDJA4Zghp7k2Ec1+c2jqup0bFkw07bwF4=
+google.golang.org/grpc v1.81.0 h1:W3G9N3KQf3BU+YuCtGKJk0CmxQNbAISICD/9AORxLIw=
+google.golang.org/grpc v1.81.0/go.mod h1:xGH9GfzOyMTGIOXBJmXt+BX/V0kcdQbdcuwQ/zNw42I=
 google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
 google.golang.org/protobuf v1.36.11/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

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

@@ -24,10 +24,12 @@ import (
 	"fmt"
 	"math"
 	"net/url"
+	"os"
 	"slices"
 	"strings"
 	"sync"
 	"sync/atomic"
+	"syscall"
 	"time"
 
 	"google.golang.org/grpc/balancer"
@@ -1268,8 +1270,9 @@ type addrConn struct {
 
 	channelz *channelz.SubChannel
 
-	localityLabel       string
-	backendServiceLabel string
+	localityLabel        string
+	backendServiceLabel  string
+	disconnectErrorLabel string
 }
 
 // Note: this requires a lock on ac.mu.
@@ -1286,9 +1289,14 @@ func (ac *addrConn) updateConnectivityState(s connectivity.State, lastErr error)
 	// TODO: https://github.com/grpc/grpc-go/issues/7862 - Remove the second
 	// part of the if condition below once the issue is fixed.
 	if ac.state == connectivity.Ready || (ac.state == connectivity.Connecting && s == connectivity.Idle) {
-		disconnectionsMetric.Record(ac.cc.metricsRecorderList, 1, ac.cc.target, ac.backendServiceLabel, ac.localityLabel, "unknown")
+		disconnectError := ac.disconnectErrorLabel
+		if disconnectError == "" {
+			disconnectError = "unknown"
+		}
+		disconnectionsMetric.Record(ac.cc.metricsRecorderList, 1, ac.cc.target, ac.backendServiceLabel, ac.localityLabel, disconnectError)
 		openConnectionsMetric.Record(ac.cc.metricsRecorderList, -1, ac.cc.target, ac.backendServiceLabel, ac.securityLevelLocked(), ac.localityLabel)
 	}
+	ac.disconnectErrorLabel = "" // Reset for next time
 	ac.state = s
 	ac.channelz.ChannelMetrics.State.Store(&s)
 	if lastErr == nil {
@@ -1483,11 +1491,11 @@ func (ac *addrConn) createTransport(ctx context.Context, addr resolver.Address,
 	addr.ServerName = ac.cc.getServerName(addr)
 	hctx, hcancel := context.WithCancel(ctx)
 
-	onClose := func(r transport.GoAwayReason) {
+	onClose := func(info transport.GoAwayInfo) {
 		ac.mu.Lock()
 		defer ac.mu.Unlock()
 		// adjust params based on GoAwayReason
-		ac.adjustParams(r)
+		ac.adjustParams(info.Reason)
 		if ctx.Err() != nil {
 			// Already shut down or connection attempt canceled.  tearDown() or
 			// updateAddrs() already cleared the transport and canceled hctx
@@ -1504,6 +1512,7 @@ func (ac *addrConn) createTransport(ctx context.Context, addr resolver.Address,
 			return
 		}
 		ac.transport = nil
+		ac.disconnectErrorLabel = disconnectErrorString(info)
 		// Refresh the name resolver on any connection loss.
 		ac.cc.resolveNow(resolver.ResolveNowOptions{})
 		// Always go idle and wait for the LB policy to initiate a new
@@ -1560,6 +1569,32 @@ func (ac *addrConn) createTransport(ctx context.Context, addr resolver.Address,
 	return nil
 }
 
+// disconnectErrorString returns the grpc.disconnect_error metric label corresponding
+// to the provided transport.GoAwayInfo, as specified by gRFC A94:
+// https://github.com/grpc/proposal/blob/master/A94-grpc-subchannel-disconnections-metrics.md
+func disconnectErrorString(info transport.GoAwayInfo) string {
+	err := info.Err
+	var sysErr syscall.Errno
+	switch {
+	case info.Reason != transport.GoAwayInvalid:
+		return fmt.Sprintf("GOAWAY %s", info.GoAwayCode.String())
+	case err == nil:
+		return "unknown"
+	case errors.Is(err, context.Canceled):
+		return "subchannel shutdown"
+	case errors.Is(err, syscall.ECONNRESET):
+		return "connection reset"
+	case errors.Is(err, syscall.ETIMEDOUT), errors.Is(err, context.DeadlineExceeded), errors.Is(err, os.ErrDeadlineExceeded):
+		return "connection timed out"
+	case errors.Is(err, syscall.ECONNABORTED):
+		return "connection aborted"
+	case errors.As(err, &sysErr):
+		return "socket error"
+	default:
+		return "unknown"
+	}
+}
+
 // startHealthCheck starts the health checking stream (RPC) to watch the health
 // stats of this connection if health checking is requested and configured.
 //
@@ -1663,6 +1698,9 @@ func (ac *addrConn) tearDown(err error) {
 	}
 	curTr := ac.transport
 	ac.transport = nil
+	if ac.disconnectErrorLabel == "" {
+		ac.disconnectErrorLabel = "subchannel shutdown"
+	}
 	// We have to set the state to Shutdown before anything else to prevent races
 	// between setting the state and logic that waits on context cancellation / etc.
 	ac.updateConnectivityState(connectivity.Shutdown, nil)

vendor/google.golang.org/grpc/experimental/stats/metrics.go

@@ -20,10 +20,27 @@
 package stats
 
 import (
+	"context"
+
 	"google.golang.org/grpc/internal"
 	"google.golang.org/grpc/stats"
 )
 
+type customLabelKey struct{}
+
+// NewContextWithCustomLabel returns a new context with the provided custom label
+// attached. The label will be propagated to all metric instruments specified in gRFC A108.
+func NewContextWithCustomLabel(ctx context.Context, label string) context.Context {
+	return context.WithValue(ctx, customLabelKey{}, label)
+}
+
+// CustomLabelFromContext returns the custom label from the context if it exists.
+// If the custom label is not present, it returns an empty string.
+func CustomLabelFromContext(ctx context.Context) string {
+	label, _ := ctx.Value(customLabelKey{}).(string)
+	return label
+}
+
 // MetricsRecorder records on metrics derived from metric registry.
 // Implementors must embed UnimplementedMetricsRecorder.
 type MetricsRecorder interface {

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

@@ -126,6 +126,16 @@ var (
 	// enabled by setting the env variable
 	// GRPC_EXPERIMENTAL_ENABLE_PRIORITY_LB_CHILD_POLICY_CACHE to true.
 	EnablePriorityLBChildPolicyCache = boolFromEnv("GRPC_EXPERIMENTAL_ENABLE_PRIORITY_LB_CHILD_POLICY_CACHE", false)
+
+	// EnableHTTPFramerReadBufferPooling enables the use of the
+	// readyreader.Reader interface to perform non-memory-pinning reads,
+	// provided the underlying net.Conn supports it. This reduces memory usage
+	// when subchannels are idle.
+	//
+	// This environment variable serves as an escape hatch to disable the
+	// feature if unforeseen issues arise, and it will be removed in a future
+	// release.
+	EnableHTTPFramerReadBufferPooling = boolFromEnv("GRPC_GO_EXPERIMENTAL_HTTP_FRAMER_READ_BUFFER_POOLING", true)
 )
 
 func boolFromEnv(envVar string, def bool) bool {

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

@@ -79,4 +79,14 @@ var (
 	// xDS bootstrap configuration via the `call_creds` field. For more details,
 	// see: https://github.com/grpc/proposal/blob/master/A97-xds-jwt-call-creds.md
 	XDSBootstrapCallCredsEnabled = boolFromEnv("GRPC_EXPERIMENTAL_XDS_BOOTSTRAP_CALL_CREDS", false)
+
+	// XDSSNIEnabled controls if gRPC should send SNI information in xDS
+	// configured TLS handshakes. For more details, see:
+	// https://github.com/grpc/proposal/blob/master/A101-SNI-setting-and-SNI-SAN-validation.md
+	XDSSNIEnabled = boolFromEnv("GRPC_EXPERIMENTAL_XDS_SNI", false)
+
+	// XDSORCAToLRSPropEnabled controls whether ORCA metrics are explicitly
+	// filtered and prefix-propagated to the LRS server. For more details, see:
+	// https://github.com/grpc/proposal/blob/master/A85-lrs-custom-metrics-changes.md
+	XDSORCAToLRSPropEnabled = boolFromEnv("GRPC_EXPERIMENTAL_XDS_ORCA_LRS_PROPAGATION", false)
 )

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

@@ -73,7 +73,7 @@ type BinaryTieredBufferPool struct {
 func NewBinaryTieredBufferPool(powerOfTwoExponents ...uint8) (*BinaryTieredBufferPool, error) {
 	return newBinaryTiered(func(size int) bufferPool {
 		return newSizedBufferPool(size, true)
-	}, &simpleBufferPool{shouldZero: true}, powerOfTwoExponents...)
+	}, &SimpleBufferPool{shouldZero: true}, powerOfTwoExponents...)
 }
 
 // NewDirtyBinaryTieredBufferPool returns a BufferPool backed by multiple
@@ -82,7 +82,7 @@ func NewBinaryTieredBufferPool(powerOfTwoExponents ...uint8) (*BinaryTieredBuffe
 func NewDirtyBinaryTieredBufferPool(powerOfTwoExponents ...uint8) (*BinaryTieredBufferPool, error) {
 	return newBinaryTiered(func(size int) bufferPool {
 		return newSizedBufferPool(size, false)
-	}, &simpleBufferPool{shouldZero: false}, powerOfTwoExponents...)
+	}, NewDirtySimplePool(), powerOfTwoExponents...)
 }
 
 func newBinaryTiered(sizedPoolFactory func(int) bufferPool, fallbackPool bufferPool, powerOfTwoExponents ...uint8) (*BinaryTieredBufferPool, error) {
@@ -258,7 +258,7 @@ func newSizedBufferPool(size int, zero bool) *sizedBufferPool {
 // buffer pools for different sizes of buffers.
 type TieredBufferPool struct {
 	sizedPools   []*sizedBufferPool
-	fallbackPool simpleBufferPool
+	fallbackPool SimpleBufferPool
 }
 
 // NewTieredBufferPool returns a BufferPool implementation that uses multiple
@@ -271,7 +271,7 @@ func NewTieredBufferPool(poolSizes ...int) *TieredBufferPool {
 	}
 	return &TieredBufferPool{
 		sizedPools:   pools,
-		fallbackPool: simpleBufferPool{shouldZero: true},
+		fallbackPool: SimpleBufferPool{shouldZero: true},
 	}
 }
 
@@ -297,16 +297,26 @@ func (p *TieredBufferPool) getPool(size int) bufferPool {
 	return p.sizedPools[poolIdx]
 }
 
-// simpleBufferPool is an implementation of the BufferPool interface that
+// SimpleBufferPool is an implementation of the mem.BufferPool interface that
 // attempts to pool buffers with a sync.Pool. When Get is invoked, it tries to
 // acquire a buffer from the pool but if that buffer is too small, it returns it
 // to the pool and creates a new one.
-type simpleBufferPool struct {
+type SimpleBufferPool struct {
 	pool       sync.Pool
 	shouldZero bool
 }
 
-func (p *simpleBufferPool) Get(size int) *[]byte {
+// NewDirtySimplePool constructs a [SimpleBufferPool]. It does not initialize
+// the buffers before returning them. Callers must ensure they don't read the
+// buffers before writing data to them.
+func NewDirtySimplePool() *SimpleBufferPool {
+	return &SimpleBufferPool{
+		shouldZero: false,
+	}
+}
+
+// Get returns a buffer with specified length from the pool.
+func (p *SimpleBufferPool) Get(size int) *[]byte {
 	bs, ok := p.pool.Get().(*[]byte)
 	if ok && cap(*bs) >= size {
 		if p.shouldZero {
@@ -333,6 +343,7 @@ func (p *simpleBufferPool) Get(size int) *[]byte {
 	return &b
 }
 
-func (p *simpleBufferPool) Put(buf *[]byte) {
+// Put returns a buffer to the pool.
+func (p *SimpleBufferPool) Put(buf *[]byte) {
 	p.pool.Put(buf)
 }

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

@@ -115,6 +115,9 @@ type ClientInterceptor interface {
 	// ClientStream after done is called, since the interceptor is invoked by
 	// application-layer operations.  done must never be nil when called.
 	NewStream(ctx context.Context, ri RPCInfo, done func(), newStream func(ctx context.Context, done func()) (ClientStream, error)) (ClientStream, error)
+	// Close closes the interceptor. Once called, no new calls to NewStream are
+	// accepted. Ongoing calls to NewStream are allowed to complete.
+	Close()
 }
 
 // ServerInterceptor is an interceptor for incoming RPC's on gRPC server side.
@@ -123,6 +126,9 @@ type ServerInterceptor interface {
 	// information about connection RPC was received on, and HTTP Headers. This
 	// information will be piped into context.
 	AllowRPC(ctx context.Context) error // TODO: Make this a real interceptor for filters such as rate limiting.
+	// Close closes the interceptor. Once called, no new calls to NewStream are
+	// accepted. Ongoing calls to NewStream are allowed to complete.
+	Close()
 }
 
 type csKeyType string

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

@@ -134,6 +134,8 @@ type http2Client struct {
 	// goAwayDebugMessage contains a detailed human readable string about a
 	// GoAway frame, useful for error messages.
 	goAwayDebugMessage string
+	// goAwayCode records the http2.ErrCode received with the GoAway frame.
+	goAwayCode http2.ErrCode
 	// A condition variable used to signal when the keepalive goroutine should
 	// go dormant. The condition for dormancy is based on the number of active
 	// streams and the `PermitWithoutStream` keepalive client parameter. And
@@ -147,7 +149,7 @@ type http2Client struct {
 
 	channelz *channelz.Socket
 
-	onClose func(GoAwayReason)
+	onClose OnCloseFunc
 
 	bufferPool mem.BufferPool
 
@@ -204,7 +206,7 @@ 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, onClose func(GoAwayReason)) (_ ClientTransport, err error) {
+func NewHTTP2Client(connectCtx, ctx context.Context, addr resolver.Address, opts ConnectOptions, onClose OnCloseFunc) (_ ClientTransport, err error) {
 	scheme := "http"
 	ctx, cancel := context.WithCancel(ctx)
 	defer func() {
@@ -1015,7 +1017,7 @@ func (t *http2Client) Close(err error) {
 	// Call t.onClose ASAP to prevent the client from attempting to create new
 	// streams.
 	if t.state != draining {
-		t.onClose(GoAwayInvalid)
+		t.onClose(GoAwayInfo{Reason: GoAwayInvalid, GoAwayCode: http2.ErrCodeNo, Err: err})
 	}
 	t.state = closing
 	streams := t.activeStreams
@@ -1086,7 +1088,7 @@ func (t *http2Client) GracefulClose() {
 	if t.logger.V(logLevel) {
 		t.logger.Infof("GracefulClose called")
 	}
-	t.onClose(GoAwayInvalid)
+	t.onClose(GoAwayInfo{Reason: GoAwayInvalid, GoAwayCode: http2.ErrCodeNo})
 	t.state = draining
 	active := len(t.activeStreams)
 	t.mu.Unlock()
@@ -1236,7 +1238,10 @@ func (t *http2Client) handleData(f *parsedDataFrame) {
 	// The server has closed the stream without sending trailers.  Record that
 	// the read direction is closed, and set the status appropriately.
 	if f.StreamEnded() {
-		t.closeStream(s, io.EOF, false, http2.ErrCodeNo, status.New(codes.Internal, "server closed the stream without sending trailers"), nil, 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.New(codes.Internal, "server closed the stream without sending trailers"), nil, true)
 	}
 }
 
@@ -1372,7 +1377,7 @@ func (t *http2Client) handleGoAway(f *http2.GoAwayFrame) error {
 		// draining, to allow the client to stop attempting to create streams
 		// before disallowing new streams on this connection.
 		if t.state != draining {
-			t.onClose(t.goAwayReason)
+			t.onClose(GoAwayInfo{Reason: t.goAwayReason, GoAwayCode: t.goAwayCode})
 			t.state = draining
 		}
 	}
@@ -1422,6 +1427,7 @@ func (t *http2Client) setGoAwayReason(f *http2.GoAwayFrame) {
 	} else {
 		t.goAwayDebugMessage = fmt.Sprintf("code: %s, debug data: %q", f.ErrCode, string(f.DebugData()))
 	}
+	t.goAwayCode = f.ErrCode
 }
 
 func (t *http2Client) GetGoAwayReason() (GoAwayReason, string) {

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

@@ -36,6 +36,9 @@ import (
 	"golang.org/x/net/http2"
 	"golang.org/x/net/http2/hpack"
 	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/internal/envconfig"
+	imem "google.golang.org/grpc/internal/mem"
+	"google.golang.org/grpc/internal/transport/readyreader"
 	"google.golang.org/grpc/mem"
 )
 
@@ -296,7 +299,7 @@ func decodeGrpcMessageUnchecked(msg string) string {
 }
 
 type bufWriter struct {
-	pool      *sync.Pool
+	pool      *imem.SimpleBufferPool
 	buf       []byte
 	offset    int
 	batchSize int
@@ -304,7 +307,7 @@ type bufWriter struct {
 	err       error
 }
 
-func newBufWriter(conn io.Writer, batchSize int, pool *sync.Pool) *bufWriter {
+func newBufWriter(conn io.Writer, batchSize int, pool *imem.SimpleBufferPool) *bufWriter {
 	w := &bufWriter{
 		batchSize: batchSize,
 		conn:      conn,
@@ -326,7 +329,7 @@ func (w *bufWriter) Write(b []byte) (int, error) {
 		return n, toIOError(err)
 	}
 	if w.buf == nil {
-		b := w.pool.Get().(*[]byte)
+		b := w.pool.Get(w.batchSize)
 		w.buf = *b
 	}
 	written := 0
@@ -407,22 +410,32 @@ type framer struct {
 	errDetail error
 }
 
-var writeBufferPoolMap = make(map[int]*sync.Pool)
-var writeBufferMutex sync.Mutex
+var ioBufferPoolMap = make(map[int]*imem.SimpleBufferPool)
+var ioBufferMutex sync.Mutex
+
+func bufferedReader(r io.Reader, bufSize int) io.Reader {
+	if bufSize <= 0 {
+		return r
+	}
+	if envconfig.EnableHTTPFramerReadBufferPooling {
+		if rr := readyreader.NewNonBlocking(r); rr != nil {
+			readPool := ioBufferPool(bufSize)
+			return readyreader.NewBuffered(rr, bufSize, readPool)
+		}
+	}
+	return bufio.NewReaderSize(r, bufSize)
+}
 
 func newFramer(conn io.ReadWriter, writeBufferSize, readBufferSize int, sharedWriteBuffer bool, maxHeaderListSize uint32, memPool mem.BufferPool) *framer {
 	if writeBufferSize < 0 {
 		writeBufferSize = 0
 	}
-	var r io.Reader = conn
-	if readBufferSize > 0 {
-		r = bufio.NewReaderSize(r, readBufferSize)
-	}
-	var pool *sync.Pool
+	r := bufferedReader(conn, readBufferSize)
+	var writePool *imem.SimpleBufferPool
 	if sharedWriteBuffer {
-		pool = getWriteBufferPool(writeBufferSize)
+		writePool = ioBufferPool(writeBufferSize)
 	}
-	w := newBufWriter(conn, writeBufferSize, pool)
+	w := newBufWriter(conn, writeBufferSize, writePool)
 	f := &framer{
 		writer: w,
 		fr:     http2.NewFramer(w, r),
@@ -578,20 +591,15 @@ func (df *parsedDataFrame) Header() http2.FrameHeader {
 	return df.FrameHeader
 }
 
-func getWriteBufferPool(size int) *sync.Pool {
-	writeBufferMutex.Lock()
-	defer writeBufferMutex.Unlock()
-	pool, ok := writeBufferPoolMap[size]
+func ioBufferPool(size int) *imem.SimpleBufferPool {
+	ioBufferMutex.Lock()
+	defer ioBufferMutex.Unlock()
+	pool, ok := ioBufferPoolMap[size]
 	if ok {
 		return pool
 	}
-	pool = &sync.Pool{
-		New: func() any {
-			b := make([]byte, size)
-			return &b
-		},
-	}
-	writeBufferPoolMap[size] = pool
+	pool = imem.NewDirtySimplePool()
+	ioBufferPoolMap[size] = pool
 	return pool
 }
 

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

@@ -0,0 +1,39 @@
+/*
+ *
+ * Copyright 2026 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 readyreader
+
+import "syscall"
+
+func isRawConnSupported() bool {
+	return true
+}
+
+// sysRead uses the standard syscall package rather than the modern unix package
+// to avoid triggering the race detector. Because both packages perform sync
+// operations on a local variable to satisfy the race detector, mixing them
+// for read and write syscalls causes data races. We use syscall here to remain
+// consistent with net.Conn implementations in standard library.
+func sysRead(fd uintptr, p []byte) (int, error) {
+	return syscall.Read(int(fd), p)
+}
+
+// wouldBlock checks standard Unix non-blocking errors.
+func wouldBlock(err error) bool {
+	return err == syscall.EAGAIN || err == syscall.EWOULDBLOCK
+}

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

@@ -0,0 +1,35 @@
+//go:build !linux
+
+/*
+ *
+ * Copyright 2026 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 readyreader
+
+func isRawConnSupported() bool {
+	return false
+}
+
+// sysRead is not implemented. Support can be added in the future if necessary.
+func sysRead(uintptr, []byte) (int, error) {
+	panic("RawConn functionality is not implemented for non-unix platforms.")
+}
+
+// wouldBlock is not implemented. Support can be added in the future if necessary.
+func wouldBlock(error) bool {
+	panic("RawConn functionality is not implemented for non-unix platforms.")
+}

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

@@ -0,0 +1,253 @@
+/*
+ *
+ * Copyright 2026 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 readyreader provides utilities to perform non-memory-pinning reads.
+package readyreader
+
+import (
+	"io"
+	"net"
+	"syscall"
+
+	"google.golang.org/grpc/mem"
+)
+
+// Reader is an optional interface that can be implemented by [net.Conn]
+// implementations to enable gRPC to perform non-memory-pinning reads.
+type Reader interface {
+	// ReadOnReady waits for data to arrive, fetches a buffer, and performs a
+	// read. When the underlying IO is readable, it allocates a buffer of size
+	// bufSize from the pool and reads up to bufSize bytes into the buffer.
+	//
+	// It returns a pointer to the buffer so it can be returned to the pool
+	// later, the number of bytes read, and an error.
+	//
+	// Callers should always process the n > 0 bytes returned before considering
+	// the error. Doing so correctly handles I/O errors that happen after
+	// reading some bytes, as well as both of the allowed EOF behaviors.
+	ReadOnReady(bufSize int, pool mem.BufferPool) (b *[]byte, n int, err error)
+}
+
+// nonBlockingReader is optimized for non-memory-pinning reads using the RawConn
+// interface.
+type nonBlockingReader struct {
+	raw syscall.RawConn
+	// The following fields are stored as field to avoid heap allocations.
+	state  readState
+	doRead func(fd uintptr) bool
+}
+
+type readState struct {
+	// Request params.
+	bufSize int
+	pool    mem.BufferPool
+
+	// Response params.
+	readError error
+	bytesRead int
+	buf       *[]byte
+}
+
+// NewNonBlocking returns a ReadyReader if the passed reader supports
+// non-memory-pinning reads, else nil.
+func NewNonBlocking(r io.Reader) Reader {
+	if rr, ok := r.(Reader); ok {
+		return rr
+	}
+	if !isRawConnSupported() {
+		return nil
+	}
+	// We restrict the types before asserting syscall.Conn. The credentials
+	// package may return a wrapper that implements syscall.Conn by embedding
+	// both the raw connection and the encrypted connection. If the code
+	// attempts to read directly from the raw syscall.RawConn, it would read
+	// encrypted data.
+	switch r.(type) {
+	case *net.TCPConn, *net.UDPConn, *net.UnixConn, *net.IPConn:
+	default:
+		return nil
+	}
+	sysConn, ok := r.(syscall.Conn)
+	if !ok {
+		return nil
+	}
+	raw, err := sysConn.SyscallConn()
+	if err != nil {
+		return nil
+	}
+	rr := &nonBlockingReader{raw: raw}
+	rr.doRead = func(fd uintptr) bool {
+		s := &rr.state
+
+		s.buf = s.pool.Get(s.bufSize)
+		s.bytesRead, s.readError = sysRead(fd, *s.buf)
+
+		if s.readError != nil {
+			s.pool.Put(s.buf)
+			s.buf = nil
+		}
+		return !wouldBlock(s.readError)
+	}
+	return rr
+}
+
+func (c *nonBlockingReader) ReadOnReady(bufSize int, pool mem.BufferPool) (*[]byte, int, error) {
+	c.state = readState{
+		pool:    pool,
+		bufSize: bufSize,
+	}
+	err := c.raw.Read(c.doRead)
+
+	buf := c.state.buf
+	n := c.state.bytesRead
+	readErr := c.state.readError
+	c.state = readState{}
+
+	if err != nil {
+		if buf != nil {
+			pool.Put(buf)
+		}
+		return nil, 0, err
+	}
+	if readErr != nil {
+		// buffer is already released in the callback.
+		return nil, 0, readErr
+	}
+	if n == 0 {
+		// syscall.Read doesn't consider a graceful socket closure to be an
+		// error condition, but Go's io.Reader expects an EOF error.
+		pool.Put(buf)
+		return nil, 0, io.EOF
+	}
+	return buf, n, nil
+}
+
+type blockingReader struct {
+	reader io.Reader
+}
+
+func (c *blockingReader) ReadOnReady(bufSize int, pool mem.BufferPool) (*[]byte, int, error) {
+	buf := pool.Get(bufSize)
+	n, err := c.reader.Read(*buf)
+	if err != nil {
+		pool.Put(buf)
+		return nil, 0, err
+	}
+	return buf, n, nil
+}
+
+// New detects if [syscall.RawConn] is available for non-memory-pinning reads.
+// If [syscall.RawConn] is unavailable, it falls back to using the simpler
+// [io.Reader] interface for reads.
+func New(r io.Reader) Reader {
+	if r := NewNonBlocking(r); r != nil {
+		return r
+	}
+	return &blockingReader{reader: r}
+}
+
+// bufReadyReader implements buffering for a ReadyReader object.
+// A new bufReadyReader is created by calling [NewBuffered].
+type bufReadyReader struct {
+	buf       *[]byte
+	pool      mem.BufferPool
+	bufSize   int
+	rd        Reader // reader provided by the caller
+	r, w      int    // buf read and write positions
+	err       error
+	constPool constBufferPool // stored as a field to avoid heap allocations.
+}
+
+// NewBuffered returns a new [io.Reader] with a buffer of the specified size
+// which is allocated from the provided pool.
+func NewBuffered(rd Reader, size int, pool mem.BufferPool) io.Reader {
+	return &bufReadyReader{
+		rd:      rd,
+		pool:    pool,
+		bufSize: size,
+	}
+}
+
+func (b *bufReadyReader) readErr() error {
+	err := b.err
+	b.err = nil
+	return err
+}
+
+func (b *bufReadyReader) buffered() int { return b.w - b.r }
+
+// Read reads data into p. It returns the number of bytes read into p. The
+// bytes are taken from at most one Read on the underlying [ReadyReader],
+// hence n may be less than len(p). If the underlying [ReadyReader] can return
+// a non-zero count with io.EOF, then this Read method can do so as well; see
+// the [io.Reader] docs.
+func (b *bufReadyReader) Read(p []byte) (n int, err error) {
+	n = len(p)
+	if n == 0 {
+		if b.buffered() > 0 {
+			return 0, nil
+		}
+		return 0, b.readErr()
+	}
+	if b.r == b.w {
+		if b.err != nil {
+			return 0, b.readErr()
+		}
+		if len(p) >= b.bufSize {
+			// Large read, empty buffer.
+			// Read directly into p to avoid copy.
+			b.constPool.buffer = p
+			_, n, b.err = b.rd.ReadOnReady(len(p), &b.constPool)
+			return n, b.readErr()
+		}
+		// One read.
+		b.r = 0
+		b.w = 0
+		b.buf, n, b.err = b.rd.ReadOnReady(b.bufSize, b.pool)
+		if n == 0 {
+			if b.buf != nil {
+				b.pool.Put(b.buf)
+				b.buf = nil
+			}
+			return 0, b.readErr()
+		}
+		b.w += n
+	}
+
+	// copy as much as we can
+	// b.buf must be non-nil since b.r != b.w.
+	buf := *b.buf
+	n = copy(p, buf[b.r:b.w])
+	b.r += n
+	if b.r == b.w {
+		// Consumed entire buffer, release it.
+		b.pool.Put(b.buf)
+		b.buf = nil
+	}
+	return n, nil
+}
+
+type constBufferPool struct {
+	buffer []byte
+}
+
+func (p *constBufferPool) Get(int) *[]byte {
+	return &p.buffer
+}
+
+func (p *constBufferPool) Put(*[]byte) {}

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

@@ -31,6 +31,7 @@ import (
 	"sync/atomic"
 	"time"
 
+	"golang.org/x/net/http2"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/credentials"
 	"google.golang.org/grpc/internal/channelz"
@@ -742,6 +743,22 @@ const (
 	GoAwayTooManyPings GoAwayReason = 2
 )
 
+// GoAwayInfo contains metadata about why a connection was closed.
+type GoAwayInfo struct {
+	// Reason is the parsed reason for an HTTP/2 GOAWAY frame.
+	Reason GoAwayReason
+	// GoAwayCode is the raw HTTP/2 error code received in a GOAWAY frame.
+	GoAwayCode http2.ErrCode
+	// Err is the underlying error that caused the connection to close. It is
+	// populated if the connection was closed due to a socket error or context
+	// cancellation without receiving a GOAWAY frame. If the connection was
+	// closed due to a GOAWAY frame, this field will be nil.
+	Err error
+}
+
+// OnCloseFunc is a callback invoked when a ClientTransport closes.
+type OnCloseFunc func(GoAwayInfo)
+
 // ContextErr converts the error from context package into a status error.
 func ContextErr(err error) error {
 	switch err {

vendor/google.golang.org/grpc/mem/buffer_slice.go

@@ -165,7 +165,7 @@ func (r *Reader) Close() error {
 }
 
 func (r *Reader) freeFirstBufferIfEmpty() bool {
-	if len(r.data) == 0 || r.bufferIdx != len(r.data[0].ReadOnlyData()) {
+	if len(r.data) == 0 || r.bufferIdx != r.data[0].Len() {
 		return false
 	}
 

vendor/google.golang.org/grpc/mem/buffers.go

@@ -53,6 +53,10 @@ type Buffer interface {
 	Free()
 	// Len returns the Buffer's size.
 	Len() int
+	// Slice returns a new Buffer that is a view into this buffer's data
+	// from [start:end). The buffer is not modified. Panics if the buffer
+	// has been freed or if start/end are out of bounds.
+	Slice(start, end int) Buffer
 
 	split(n int) (left, right Buffer)
 	read(buf []byte) (int, Buffer)
@@ -180,6 +184,32 @@ func (b *buffer) Len() int {
 	return len(b.ReadOnlyData())
 }
 
+func (b *buffer) Slice(start, end int) Buffer {
+	if b.rootBuf == nil {
+		panic("Cannot slice freed buffer")
+	}
+
+	data := b.data[start:end] // access the data to check slice bounds
+
+	if len(data) == 0 {
+		return emptyBuffer{}
+	}
+	if len(data) == len(b.data) {
+		b.Ref()
+		return b
+	}
+	// We are creating a new reference (view) to a portion of the root buffer's
+	// data. Therefore, we must increment the reference count of the root buffer
+	// to ensure the underlying data is not freed while this view is still in
+	// use.
+	b.rootBuf.Ref()
+	s := newBuffer()
+	s.data = data
+	s.rootBuf = b.rootBuf
+	s.refs.Store(1)
+	return s
+}
+
 func (b *buffer) split(n int) (Buffer, Buffer) {
 	if b.rootBuf == nil || b.rootBuf.refs.Add(1) <= 1 {
 		panic("Cannot split freed buffer")
@@ -240,6 +270,13 @@ func (e emptyBuffer) Len() int {
 	return 0
 }
 
+func (e emptyBuffer) Slice(start, end int) Buffer {
+	if start != 0 || end != 0 {
+		panic(fmt.Sprintf("slice bounds out of range [%d:%d] with length 0", start, end))
+	}
+	return e
+}
+
 func (e emptyBuffer) split(int) (left, right Buffer) {
 	return e, e
 }
@@ -264,6 +301,9 @@ func (s SliceBuffer) Free() {}
 // Len is a noop implementation of Len.
 func (s SliceBuffer) Len() int { return len(s) }
 
+// Slice returns a new SliceBuffer that is a view into the receiver from [start:end).
+func (s SliceBuffer) Slice(start, end int) Buffer { return s[start:end] }
+
 func (s SliceBuffer) split(n int) (left, right Buffer) {
 	return s[:n], s[n:]
 }

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

@@ -21,6 +21,7 @@ package grpc
 import (
 	"context"
 	"errors"
+	"fmt"
 	"io"
 	"math"
 	rand "math/rand/v2"
@@ -749,7 +750,7 @@ func (a *csAttempt) shouldRetry(err error) (bool, error) {
 		return false, err
 	}
 	if cs.numRetries+1 >= rp.MaxAttempts {
-		return false, err
+		return false, fmt.Errorf("max retries exhausted: failed after %d attempts: %w", cs.numRetries+1, err)
 	}
 
 	var dur time.Duration

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

@@ -19,4 +19,4 @@
 package grpc
 
 // Version is the current grpc version.
-const Version = "1.80.0"
+const Version = "1.81.0"

vendor/modules.txt

@@ -1054,8 +1054,8 @@ google.golang.org/genproto/googleapis/api/annotations
 # google.golang.org/genproto/googleapis/rpc v0.0.0-20260401024825-9d38bb4040a9
 ## explicit; go 1.25.0
 google.golang.org/genproto/googleapis/rpc/status
-# google.golang.org/grpc v1.80.0
-## explicit; go 1.24.0
+# google.golang.org/grpc v1.81.0
+## explicit; go 1.25.0
 google.golang.org/grpc
 google.golang.org/grpc/attributes
 google.golang.org/grpc/backoff
@@ -1108,6 +1108,7 @@ google.golang.org/grpc/internal/status
 google.golang.org/grpc/internal/syscall
 google.golang.org/grpc/internal/transport
 google.golang.org/grpc/internal/transport/networktype
+google.golang.org/grpc/internal/transport/readyreader
 google.golang.org/grpc/keepalive
 google.golang.org/grpc/mem
 google.golang.org/grpc/metadata