fix: 错误队列不能只读前两个，增加了清除功能，读完全部错误队列

cmd/internal/transport/tcp_linux.go

@@ -7,6 +7,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"strings"
 	"syscall"
 	"time"
 
@@ -18,7 +19,6 @@ 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
@@ -36,6 +36,8 @@ const (
 )
 
 // 拿到底层 fd，并打开 Linux timestamping。
+const linuxTXTimestampDrainQuietTime = 5 * time.Millisecond
+
 func (c *TCPConn) initLinuxTimestamping() error {
 	sysConn, ok := c.conn.(interface {
 		SyscallConn() (syscall.RawConn, error)
@@ -106,6 +108,10 @@ func enableLinuxTimestamping(rawConn syscall.RawConn) error {
 
 // sendMessageLinux 编码消息、写完整帧，再记录 TX 时间戳。
 func (c *TCPConn) sendMessageLinux(msg protocol.Message) error {
+	// Clear any stale TX timestamp entries left by previous large writes before
+	// sending the next message. Otherwise later sends may log old kernel times.
+	c.drainPendingTXTimestampEvents()
+
 	payload, err := protocol.EncodeMessage(msg)
 	if err != nil {
 		return fmt.Errorf("protocol: encode message: %w", err)
@@ -127,20 +133,43 @@ 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
 
-	for written < len(frame) {
-		n, err := c.sendmsgDataOnce(frame[written:])
+	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)
 		switch {
-		case err == nil:
+		case sendErr == nil:
 			if n <= 0 {
-				return io.ErrShortWrite
+				opErr = io.ErrShortWrite
+				return true
 			}
 			written += n
-		case isWouldBlock(err):
-			time.Sleep(linuxDataPollInterval)
+			return written >= len(frame)
+		case errors.Is(sendErr, syscall.EAGAIN), errors.Is(sendErr, syscall.EWOULDBLOCK):
+			return false
 		default:
-			return err
+			opErr = sendErr
+			return true
 		}
+	})
+	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
@@ -159,25 +188,51 @@ func (c *TCPConn) logTXTimestampEvents(msg protocol.Message) {
 }
 
 // 在 errqueue 里等两类 TX 时间戳。
+func (c *TCPConn) drainPendingTXTimestampEvents() {
+	for {
+		_, _, err := c.recvTXTimestampOnce()
+		switch {
+		case err == nil:
+			continue
+		case isWouldBlock(err):
+			return
+		default:
+			return
+		}
+	}
+}
+
 func (c *TCPConn) collectTXTimestampEvents() map[string]int64 {
 	timestamps := make(map[string]int64, 2)
 	//设置合理等待上限
 	deadline := time.Now().Add(linuxTXTimestampWaitTimeout)
+	var quietDeadline time.Time
 
 	//轮询 errqueue 直到拿到两类时间戳，或超时，或遇到非 EAGAIN 错误。
-	for len(timestamps) < 2 && time.Now().Before(deadline) {
+	for time.Now().Before(deadline) {
 		eventName, ts, err := c.recvTXTimestampOnce()
 		if err != nil {
 			if isWouldBlock(err) {
+				if len(timestamps) == 0 {
+					time.Sleep(linuxTXTimestampPollInterval)
+					continue
+				}
+				if quietDeadline.IsZero() {
+					quietDeadline = time.Now().Add(linuxTXTimestampDrainQuietTime)
+				}
+				if time.Now().After(quietDeadline) {
+					return timestamps
+				}
 				time.Sleep(linuxTXTimestampPollInterval)
 				continue
 			}
-			break
+			return timestamps
 		}
+		quietDeadline = time.Time{}
 		if eventName == "" || ts <= 0 {
 			continue
 		}
-		if _, exists := timestamps[eventName]; !exists {
+		if existing, exists := timestamps[eventName]; !exists || ts < existing {
 			timestamps[eventName] = ts
 		}
 	}
@@ -351,6 +406,15 @@ 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
 			}
@@ -365,20 +429,39 @@ 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) {
-	for {
-		n, rxTimeNS, err := c.recvmsgDataOnce(buf)
+	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)
 		switch {
-		case err == nil:
-			if n == 0 {
-				return 0, 0, io.EOF
+		case recvErr == nil:
+			if readN == 0 {
+				opErr = io.EOF
+				return true
 			}
-			return n, rxTimeNS, nil
-		case isWouldBlock(err):
-			time.Sleep(linuxDataPollInterval)
+			n = readN
+			rxTimeNS = parseRXTimestampControlMessages(oob[:oobN])
+			return true
+		case errors.Is(recvErr, syscall.EAGAIN), errors.Is(recvErr, syscall.EWOULDBLOCK):
+			return false
 		default:
-			return 0, 0, err
+			opErr = recvErr
+			return true
 		}
+	})
+	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。
@@ -426,42 +509,26 @@ func isWouldBlock(err error) bool {
 	return errors.Is(err, syscall.EAGAIN) || errors.Is(err, syscall.EWOULDBLOCK)
 }
 
-func (c *TCPConn) sendmsgDataOnce(buf []byte) (int, error) {
-	var (
-		n     int
-		opErr error
-	)
-
-	err := c.raw.Control(func(fd uintptr) {
-		n, opErr = syscall.SendmsgN(int(fd), buf, nil, nil, 0)
-	})
-	if err != nil {
-		return 0, err
-	}
-
-	return n, opErr
+func isRawConnNotPollable(err error) bool {
+	return err != nil && strings.Contains(err.Error(), "not pollable")
 }
 
-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
+func writeFullFallback(w io.Writer, buf []byte) error {
+	for len(buf) > 0 {
+		n, err := w.Write(buf)
+		if err != nil {
+			return err
 		}
-		n = readN
-		rxTimeNS = parseRXTimestampControlMessages(oob[:oobN])
-	})
-	if err != nil {
-		return 0, 0, err
+		if n <= 0 {
+			return io.ErrShortWrite
+		}
+		buf = buf[n:]
 	}
 
-	return n, rxTimeNS, opErr
+	return nil
+}
+
+func readFullFallback(r io.Reader, buf []byte) error {
+	_, err := io.ReadFull(r, buf)
+	return err
 }