alts: increase write record size max to 1MB

cmd/protoc-gen-go-grpc/go.mod

@@ -1,6 +1,6 @@
 module google.golang.org/grpc/cmd/protoc-gen-go-grpc
 
-go 1.23.0
+go 1.24.0
 
 require (
 	google.golang.org/grpc v1.70.0

credentials/alts/internal/conn/common.go

@@ -19,9 +19,7 @@
 package conn
 
 import (
-	"encoding/binary"
 	"errors"
-	"fmt"
 )
 
 const (
@@ -48,33 +46,3 @@ func SliceForAppend(in []byte, n int) (head, tail []byte) {
 	tail = head[len(in):]
 	return head, tail
 }
-
-// ParseFramedMsg parse the provided buffer and returns a frame of the format
-// msgLength+msg and any remaining bytes in that buffer.
-func ParseFramedMsg(b []byte, maxLen uint32) ([]byte, []byte, error) {
-	// If the size field is not complete, return the provided buffer as
-	// remaining buffer.
-	length, sufficientBytes := parseMessageLength(b)
-	if !sufficientBytes {
-		return nil, b, nil
-	}
-	if length > maxLen {
-		return nil, nil, fmt.Errorf("received the frame length %d larger than the limit %d", length, maxLen)
-	}
-	if len(b) < int(length)+4 { // account for the first 4 msg length bytes.
-		// Frame is not complete yet.
-		return nil, b, nil
-	}
-	return b[:MsgLenFieldSize+length], b[MsgLenFieldSize+length:], nil
-}
-
-// parseMessageLength returns the message length based on frame header. It also
-// returns a boolean indicating if the buffer contains sufficient bytes to parse
-// the length header. If there are insufficient bytes, (0, false) is returned.
-func parseMessageLength(b []byte) (uint32, bool) {
-	if len(b) < MsgLenFieldSize {
-		return 0, false
-	}
-	msgLenField := b[:MsgLenFieldSize]
-	return binary.LittleEndian.Uint32(msgLenField), true
-}

credentials/alts/internal/conn/record.go

@@ -56,17 +56,12 @@ const (
 	MsgLenFieldSize = 4
 	// The byte size of the message type field of a framed message.
 	msgTypeFieldSize = 4
-	// The bytes size limit for a ALTS record message.
+	// The bytes size limit for an ALTS record message.
 	altsRecordLengthLimit = 1024 * 1024 // 1 MiB
-	// The default bytes size of a ALTS record message.
-	altsRecordDefaultLength = 4 * 1024 // 4KiB
 	// Message type value included in ALTS record framing.
 	altsRecordMsgType = uint32(0x06)
 	// The initial write buffer size.
 	altsWriteBufferInitialSize = 32 * 1024 // 32KiB
-	// The maximum write buffer size. This *must* be multiple of
-	// altsRecordDefaultLength.
-	altsWriteBufferMaxSize = 512 * 1024 // 512KiB
 	// The initial buffer used to read from the network.
 	altsReadBufferInitialSize = 32 * 1024 // 32KiB
 )
@@ -116,7 +111,7 @@ func NewConn(c net.Conn, side core.Side, recordProtocol string, key []byte, prot
 		return nil, fmt.Errorf("protocol %q: %v", recordProtocol, err)
 	}
 	overhead := MsgLenFieldSize + msgTypeFieldSize + crypto.EncryptionOverhead()
-	payloadLengthLimit := altsRecordDefaultLength - overhead
+	payloadLengthLimit := altsRecordLengthLimit - overhead
 	// We pre-allocate protected to be of size 32KB during initialization.
 	// We increase the size of the buffer by the required amount if it can't
 	// hold a complete encrypted record.
@@ -144,7 +139,7 @@ func NewConn(c net.Conn, side core.Side, recordProtocol string, key []byte, prot
 func (p *conn) Read(b []byte) (n int, err error) {
 	if len(p.buf) == 0 {
 		var framedMsg []byte
-		framedMsg, p.nextFrame, err = ParseFramedMsg(p.nextFrame, altsRecordLengthLimit)
+		framedMsg, err = p.parseFramedMsg(p.nextFrame, altsRecordLengthLimit)
 		if err != nil {
 			return n, err
 		}
@@ -184,7 +179,7 @@ func (p *conn) Read(b []byte) (n int, err error) {
 				return 0, err
 			}
 			p.protected = p.protected[:len(p.protected)+n]
-			framedMsg, p.nextFrame, err = ParseFramedMsg(p.protected, altsRecordLengthLimit)
+			framedMsg, err = p.parseFramedMsg(p.protected, altsRecordLengthLimit)
 			if err != nil {
 				return 0, err
 			}
@@ -225,6 +220,38 @@ func (p *conn) Read(b []byte) (n int, err error) {
 	return n, nil
 }
 
+// parseFramedMsg parses the provided buffer and returns a frame of the format
+// msgLength+msg iff a full frame is available.
+func (p *conn) parseFramedMsg(b []byte, maxLen uint32) ([]byte, error) {
+	// If the size field is not complete, return the provided buffer as
+	// remaining buffer.
+	p.nextFrame = b
+	length, sufficientBytes := parseMessageLength(b)
+	if !sufficientBytes {
+		return nil, nil
+	}
+	if length > maxLen {
+		return nil, fmt.Errorf("received the frame length %d larger than the limit %d", length, maxLen)
+	}
+	if len(b) < int(length)+4 { // account for the first 4 msg length bytes.
+		// Frame is not complete yet.
+		return nil, nil
+	}
+	p.nextFrame = b[MsgLenFieldSize+length:]
+	return b[:MsgLenFieldSize+length], nil
+}
+
+// parseMessageLength returns the message length based on frame header. It also
+// returns a boolean indicating if the buffer contains sufficient bytes to parse
+// the length header. If there are insufficient bytes, (0, false) is returned.
+func parseMessageLength(b []byte) (uint32, bool) {
+	if len(b) < MsgLenFieldSize {
+		return 0, false
+	}
+	msgLenField := b[:MsgLenFieldSize]
+	return binary.LittleEndian.Uint32(msgLenField), true
+}
+
 // Write encrypts, frames, and writes bytes from b to the underlying connection.
 func (p *conn) Write(b []byte) (n int, err error) {
 	n = len(b)
@@ -233,10 +260,9 @@ func (p *conn) Write(b []byte) (n int, err error) {
 	size := len(b) + numOfFrames*p.overhead
 	// If writeBuf is too small, increase its size up to the maximum size.
 	partialBSize := len(b)
-	if size > altsWriteBufferMaxSize {
-		size = altsWriteBufferMaxSize
-		const numOfFramesInMaxWriteBuf = altsWriteBufferMaxSize / altsRecordDefaultLength
-		partialBSize = numOfFramesInMaxWriteBuf * p.payloadLengthLimit
+	if size > altsRecordLengthLimit {
+		size = altsRecordLengthLimit
+		partialBSize = p.payloadLengthLimit
 	}
 	if len(p.writeBuf) < size {
 		p.writeBuf = make([]byte, size)
@@ -282,7 +308,7 @@ func (p *conn) Write(b []byte) (n int, err error) {
 			// written. This means we need to remove header,
 			// encryption overheads, and any partially-written
 			// frame data.
-			numOfWrittenFrames := int(math.Floor(float64(nn) / float64(altsRecordDefaultLength)))
+			numOfWrittenFrames := int(math.Floor(float64(nn) / float64(altsRecordLengthLimit)))
 			return partialBStart + numOfWrittenFrames*p.payloadLengthLimit, err
 		}
 	}

credentials/alts/internal/conn/record_test.go

@@ -168,8 +168,8 @@ func (s) TestSmallReadBuffer(t *testing.T) {
 func testLargeMsg(t *testing.T, rp string) {
 	clientConn, serverConn := newConnPair(rp, nil, nil)
 	// msgLen is such that the length in the framing is larger than the
-	// default size of one frame.
-	msgLen := altsRecordDefaultLength - msgTypeFieldSize - clientConn.crypto.EncryptionOverhead() + 1
+	// max size of one frame.
+	msgLen := altsRecordLengthLimit - msgTypeFieldSize - clientConn.crypto.EncryptionOverhead() + 1
 	msg := make([]byte, msgLen)
 	if n, err := clientConn.Write(msg); n != len(msg) || err != nil {
 		t.Fatalf("Write() = %v, %v; want %v, <nil>", n, err, len(msg))
@@ -292,7 +292,7 @@ func testWriteLargeData(t *testing.T, rp string) {
 	clientConn, serverConn := newConnPair(rp, nil, nil)
 	// Message size is intentionally chosen to not be multiple of
 	// payloadLengthLimit.
-	msgSize := altsWriteBufferMaxSize + (100 * 1024)
+	msgSize := altsRecordLengthLimit + (100 * 1024)
 	clientMsg := make([]byte, msgSize)
 	for i := 0; i < msgSize; i++ {
 		clientMsg[i] = 0xAA

examples/go.mod

@@ -1,6 +1,6 @@
 module google.golang.org/grpc/examples
 
-go 1.23.0
+go 1.24.0
 
 require (
 	github.com/cncf/xds/go v0.0.0-20250501225837-2ac532fd4443

gcp/observability/go.mod

@@ -1,6 +1,6 @@
 module google.golang.org/grpc/gcp/observability
 
-go 1.23.0
+go 1.24.0
 
 require (
 	cloud.google.com/go/logging v1.13.0

go.mod

@@ -1,6 +1,6 @@
 module google.golang.org/grpc
 
-go 1.23.0
+go 1.24.0
 
 require (
 	github.com/cespare/xxhash/v2 v2.3.0

interop/observability/go.mod

@@ -1,6 +1,6 @@
 module google.golang.org/grpc/interop/observability
 
-go 1.23.0
+go 1.24.0
 
 require (
 	google.golang.org/grpc v1.73.0

interop/xds/go.mod

@@ -1,6 +1,6 @@
 module google.golang.org/grpc/interop/xds
 
-go 1.23.0
+go 1.24.0
 
 replace google.golang.org/grpc => ../..
 

scripts/vet.sh

@@ -97,7 +97,7 @@ for MOD_FILE in $(find . -name 'go.mod'); do
   gofmt -s -d -l . 2>&1 | fail_on_output
   goimports -l . 2>&1 | not grep -vE "\.pb\.go"
 
-  go mod tidy -compat=1.23
+  go mod tidy -compat=1.24
   git status --porcelain 2>&1 | fail_on_output || \
     (git status; git --no-pager diff; exit 1)
 

security/advancedtls/examples/go.mod

@@ -1,6 +1,6 @@
 module google.golang.org/grpc/security/advancedtls/examples
 
-go 1.23.0
+go 1.24.0
 
 require (
 	google.golang.org/grpc v1.73.0

security/advancedtls/go.mod

@@ -1,6 +1,6 @@
 module google.golang.org/grpc/security/advancedtls
 
-go 1.23.0
+go 1.24.0
 
 require (
 	github.com/google/go-cmp v0.7.0

stats/opencensus/go.mod

@@ -1,6 +1,6 @@
 module google.golang.org/grpc/stats/opencensus
 
-go 1.23.0
+go 1.24.0
 
 require (
 	github.com/google/go-cmp v0.7.0

test/tools/go.mod

@@ -1,6 +1,6 @@
 module google.golang.org/grpc/test/tools
 
-go 1.23.0
+go 1.24.0
 
 require (
 	github.com/client9/misspell v0.3.4