fix：普通业务数据不再走 RawConn.Read/Write

cmd/internal/transport/tcp_linux.go

@@ -7,7 +7,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"strings"
 	"syscall"
 	"time"
 
@@ -19,6 +18,7 @@ const (
 	linuxTimestampControlBufferSize = 256                    // 控制消息缓冲区。
 	linuxTXTimestampWaitTimeout     = 250 * time.Millisecond // 等待 TX 时间戳的上限。
 	linuxTXTimestampPollInterval    = time.Millisecond       // 轮询 errqueue 的间隔。
+	linuxDataPollInterval           = time.Millisecond       // 轮询普通收发的间隔。
 
 	linuxSOTimestampingNew      = 0x41
 	linuxSCMTimestampingNew     = linuxSOTimestampingNew
@@ -127,43 +127,20 @@ func (c *TCPConn) sendMessageLinux(msg protocol.Message) error {
 // writeFrameLinux 用 sendmsg 写完整帧。
 func (c *TCPConn) writeFrameLinux(frame []byte) error {
 	written := 0
-	var opErr error
 
-	err := c.raw.Write(func(fd uintptr) bool {
-		if written >= len(frame) {
-			return true
-		}
-
-		n, sendErr := syscall.SendmsgN(int(fd), frame[written:], nil, nil, 0)
+	for written < len(frame) {
+		n, err := c.sendmsgDataOnce(frame[written:])
 		switch {
-		case sendErr == nil:
+		case err == nil:
 			if n <= 0 {
-				opErr = io.ErrShortWrite
-				return true
+				return io.ErrShortWrite
 			}
 			written += n
-			return written >= len(frame)
-		case errors.Is(sendErr, syscall.EAGAIN), errors.Is(sendErr, syscall.EWOULDBLOCK):
-			return false
+		case isWouldBlock(err):
+			time.Sleep(linuxDataPollInterval)
 		default:
-			opErr = sendErr
-			return true
+			return err
 		}
-	})
-	if err != nil {
-		if isRawConnNotPollable(err) {
-			return writeFullFallback(c.conn, frame[written:])
-		}
-		return err
-	}
-	if opErr != nil {
-		if isRawConnNotPollable(opErr) {
-			return writeFullFallback(c.conn, frame[written:])
-		}
-		return opErr
-	}
-	if written != len(frame) {
-		return io.ErrShortWrite
 	}
 
 	return nil
@@ -374,15 +351,6 @@ func (c *TCPConn) readFullLinux(buf []byte) (int64, error) {
 			firstRXTime = rxTimestamp
 		}
 		if err != nil {
-			if isRawConnNotPollable(err) {
-				if fallbackErr := readFullFallback(c.conn, buf[offset:]); fallbackErr != nil {
-					if errors.Is(fallbackErr, io.EOF) && offset > 0 {
-						return firstRXTime, io.ErrUnexpectedEOF
-					}
-					return firstRXTime, fallbackErr
-				}
-				return firstRXTime, nil
-			}
 			if errors.Is(err, io.EOF) && offset > 0 {
 				return firstRXTime, io.ErrUnexpectedEOF
 			}
@@ -397,39 +365,20 @@ func (c *TCPConn) readFullLinux(buf []byte) (int64, error) {
 
 // recvmsgLinux 用 recvmsg 同时读取数据和控制消息。
 func (c *TCPConn) recvmsgLinux(buf []byte) (int, int64, error) {
-	var (
-		n        int
-		rxTimeNS int64
-		opErr    error
-	)
-
-	err := c.raw.Read(func(fd uintptr) bool {
-		oob := make([]byte, linuxTimestampControlBufferSize)
-		readN, oobN, _, _, recvErr := syscall.Recvmsg(int(fd), buf, oob, 0)
+	for {
+		n, rxTimeNS, err := c.recvmsgDataOnce(buf)
 		switch {
-		case recvErr == nil:
-			if readN == 0 {
-				opErr = io.EOF
-				return true
+		case err == nil:
+			if n == 0 {
+				return 0, 0, io.EOF
 			}
-			n = readN
-			rxTimeNS = parseRXTimestampControlMessages(oob[:oobN])
-			return true
-		case errors.Is(recvErr, syscall.EAGAIN), errors.Is(recvErr, syscall.EWOULDBLOCK):
-			return false
+			return n, rxTimeNS, nil
+		case isWouldBlock(err):
+			time.Sleep(linuxDataPollInterval)
 		default:
-			opErr = recvErr
-			return true
+			return 0, 0, err
 		}
-	})
-	if err != nil {
-		return 0, 0, err
 	}
-	if opErr != nil {
-		return 0, 0, opErr
-	}
-
-	return n, rxTimeNS, nil
 }
 
 // 从控制消息里取 RX_SOFTWARE。
@@ -477,26 +426,42 @@ func isWouldBlock(err error) bool {
 	return errors.Is(err, syscall.EAGAIN) || errors.Is(err, syscall.EWOULDBLOCK)
 }
 
-func isRawConnNotPollable(err error) bool {
-	return err != nil && strings.Contains(err.Error(), "not pollable")
-}
+func (c *TCPConn) sendmsgDataOnce(buf []byte) (int, error) {
+	var (
+		n     int
+		opErr error
+	)
 
-func writeFullFallback(w io.Writer, buf []byte) error {
-	for len(buf) > 0 {
-		n, err := w.Write(buf)
-		if err != nil {
-			return err
-		}
-		if n <= 0 {
-			return io.ErrShortWrite
-		}
-		buf = buf[n:]
+	err := c.raw.Control(func(fd uintptr) {
+		n, opErr = syscall.SendmsgN(int(fd), buf, nil, nil, 0)
+	})
+	if err != nil {
+		return 0, err
 	}
 
-	return nil
+	return n, opErr
 }
 
-func readFullFallback(r io.Reader, buf []byte) error {
-	_, err := io.ReadFull(r, buf)
-	return err
+func (c *TCPConn) recvmsgDataOnce(buf []byte) (int, int64, error) {
+	var (
+		n        int
+		rxTimeNS int64
+		opErr    error
+	)
+
+	err := c.raw.Control(func(fd uintptr) {
+		oob := make([]byte, linuxTimestampControlBufferSize)
+		readN, oobN, _, _, recvErr := syscall.Recvmsg(int(fd), buf, oob, 0)
+		if recvErr != nil {
+			opErr = recvErr
+			return
+		}
+		n = readN
+		rxTimeNS = parseRXTimestampControlMessages(oob[:oobN])
+	})
+	if err != nil {
+		return 0, 0, err
+	}
+
+	return n, rxTimeNS, opErr
 }