snapshot: sagernet/gvisor v0.0.0-20250811.0-sing-box-mod.1

Содержимое пина, зафиксированного в go.mod sing-box-lx, одним коммитом
без истории. Полная история SagerNet/gvisor — 1.45 ГБ и клонируется в
каждой CI-джобе; наша дельта — одна вставка в одну функцию, история для
неё не нужна.

Module path github.com/sagernet/gvisor сохранён намеренно: на него
опирается replace-директива суперпроекта.

Патч поверх — отдельным коммитом, чтобы дельта читалась одним git show
и переносилась на новый пин копированием.

SPECS/TASKS/048-GVISOR_HANDSHAKE_NIL_CRASH

pkg/tcpip/link/sniffer/pcap.go

@@ -0,0 +1,85 @@
+// Copyright 2018 The gVisor 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 sniffer
+
+import (
+	"encoding"
+	"encoding/binary"
+	"time"
+
+	"github.com/sagernet/gvisor/pkg/tcpip"
+	"github.com/sagernet/gvisor/pkg/tcpip/stack"
+)
+
+type pcapHeader struct {
+	// MagicNumber is the file magic number.
+	MagicNumber uint32
+
+	// VersionMajor is the major version number.
+	VersionMajor uint16
+
+	// VersionMinor is the minor version number.
+	VersionMinor uint16
+
+	// Thiszone is the GMT to local correction.
+	Thiszone int32
+
+	// Sigfigs is the accuracy of timestamps.
+	Sigfigs uint32
+
+	// Snaplen is the max length of captured packets, in octets.
+	Snaplen uint32
+
+	// Network is the data link type.
+	Network uint32
+}
+
+var _ encoding.BinaryMarshaler = (*pcapPacket)(nil)
+
+type pcapPacket struct {
+	timestamp     time.Time
+	packet        *stack.PacketBuffer
+	maxCaptureLen int
+}
+
+func (p *pcapPacket) MarshalBinary() ([]byte, error) {
+	pkt := trimmedClone(p.packet)
+	defer pkt.DecRef()
+	packetSize := pkt.Size()
+	captureLen := p.maxCaptureLen
+	if packetSize < captureLen {
+		captureLen = packetSize
+	}
+	b := make([]byte, 16+captureLen)
+	binary.LittleEndian.PutUint32(b[0:4], uint32(p.timestamp.Unix()))
+	binary.LittleEndian.PutUint32(b[4:8], uint32(p.timestamp.Nanosecond()/1000))
+	binary.LittleEndian.PutUint32(b[8:12], uint32(captureLen))
+	binary.LittleEndian.PutUint32(b[12:16], uint32(packetSize))
+	w := tcpip.SliceWriter(b[16:])
+	for _, v := range pkt.AsSlices() {
+		if captureLen == 0 {
+			break
+		}
+		if len(v) > captureLen {
+			v = v[:captureLen]
+		}
+		n, err := w.Write(v)
+		if err != nil {
+			panic(err)
+		}
+		captureLen -= n
+	}
+	return b, nil
+}