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/pipe/pipe.go

@@ -0,0 +1,154 @@
+// Copyright 2020 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 pipe provides the implementation of pipe-like data-link layer
+// endpoints. Such endpoints allow packets to be sent between two interfaces.
+package pipe
+
+import (
+	"github.com/sagernet/gvisor/pkg/tcpip"
+	"github.com/sagernet/gvisor/pkg/tcpip/header"
+	"github.com/sagernet/gvisor/pkg/tcpip/stack"
+)
+
+var _ stack.LinkEndpoint = (*Endpoint)(nil)
+
+// New returns both ends of a new pipe.
+func New(linkAddr1, linkAddr2 tcpip.LinkAddress, mtu uint32) (*Endpoint, *Endpoint) {
+	ep1 := &Endpoint{
+		linkAddr: linkAddr1,
+		mtu:      mtu,
+	}
+	ep2 := &Endpoint{
+		linkAddr: linkAddr2,
+		mtu:      mtu,
+	}
+	ep1.linked = ep2
+	ep2.linked = ep1
+	return ep1, ep2
+}
+
+// Endpoint is one end of a pipe.
+//
+// +stateify savable
+type Endpoint struct {
+	linked *Endpoint
+
+	mu endpointRWMutex `state:"nosave"`
+	// +checklocks:mu
+	dispatcher stack.NetworkDispatcher
+	// +checklocks:mu
+	linkAddr tcpip.LinkAddress
+	// +checklocks:mu
+	mtu uint32
+}
+
+func (e *Endpoint) deliverPackets(pkts stack.PacketBufferList) {
+	e.linked.mu.RLock()
+	d := e.linked.dispatcher
+	e.linked.mu.RUnlock()
+	if d == nil {
+		return
+	}
+
+	for _, pkt := range pkts.AsSlice() {
+		// Create a fresh packet with pkt's payload but without struct fields
+		// or headers set so the next link protocol can properly set the link
+		// header.
+		newPkt := stack.NewPacketBuffer(stack.PacketBufferOptions{
+			Payload: pkt.ToBuffer(),
+		})
+		d.DeliverNetworkPacket(pkt.NetworkProtocolNumber, newPkt)
+		newPkt.DecRef()
+	}
+}
+
+// WritePackets implements stack.LinkEndpoint.
+func (e *Endpoint) WritePackets(pkts stack.PacketBufferList) (int, tcpip.Error) {
+	n := pkts.Len()
+	e.deliverPackets(pkts)
+	return n, nil
+}
+
+// Attach implements stack.LinkEndpoint.
+func (e *Endpoint) Attach(dispatcher stack.NetworkDispatcher) {
+	e.mu.Lock()
+	defer e.mu.Unlock()
+	e.dispatcher = dispatcher
+}
+
+// IsAttached implements stack.LinkEndpoint.
+func (e *Endpoint) IsAttached() bool {
+	e.mu.RLock()
+	defer e.mu.RUnlock()
+	return e.dispatcher != nil
+}
+
+// Wait implements stack.LinkEndpoint.
+func (*Endpoint) Wait() {}
+
+// MTU implements stack.LinkEndpoint.
+func (e *Endpoint) MTU() uint32 {
+	e.mu.RLock()
+	defer e.mu.RUnlock()
+	return e.mtu
+}
+
+// SetMTU implements stack.LinkEndpoint.
+func (e *Endpoint) SetMTU(mtu uint32) {
+	e.mu.Lock()
+	defer e.mu.Unlock()
+	e.mtu = mtu
+}
+
+// Capabilities implements stack.LinkEndpoint.
+func (*Endpoint) Capabilities() stack.LinkEndpointCapabilities {
+	return 0
+}
+
+// MaxHeaderLength implements stack.LinkEndpoint.
+func (*Endpoint) MaxHeaderLength() uint16 {
+	return 0
+}
+
+// LinkAddress implements stack.LinkEndpoint.
+func (e *Endpoint) LinkAddress() tcpip.LinkAddress {
+	e.mu.RLock()
+	defer e.mu.RUnlock()
+	return e.linkAddr
+}
+
+// SetLinkAddress implements stack.LinkEndpoint.
+func (e *Endpoint) SetLinkAddress(addr tcpip.LinkAddress) {
+	e.mu.Lock()
+	defer e.mu.Unlock()
+	e.linkAddr = addr
+}
+
+// ARPHardwareType implements stack.LinkEndpoint.
+func (*Endpoint) ARPHardwareType() header.ARPHardwareType {
+	return header.ARPHardwareNone
+}
+
+// AddHeader implements stack.LinkEndpoint.
+func (*Endpoint) AddHeader(*stack.PacketBuffer) {}
+
+// ParseHeader implements stack.LinkEndpoint.
+func (*Endpoint) ParseHeader(*stack.PacketBuffer) bool { return true }
+
+// Close implements stack.LinkEndpoint.
+func (e *Endpoint) Close() {}
+
+// SetOnCloseAction implements stack.LinkEndpoint.SetOnCloseAction.
+func (*Endpoint) SetOnCloseAction(func()) {}