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/packetsocket/packetsocket.go

@@ -0,0 +1,62 @@
+// Copyright 2022 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 packetsocket provides a link endpoint that enables delivery of
+// incoming and outgoing packets to any interested packet sockets.
+package packetsocket
+
+import (
+	"github.com/sagernet/gvisor/pkg/tcpip"
+	"github.com/sagernet/gvisor/pkg/tcpip/link/nested"
+	"github.com/sagernet/gvisor/pkg/tcpip/stack"
+)
+
+var (
+	_ stack.NetworkDispatcher = (*Endpoint)(nil)
+	_ stack.LinkEndpoint      = (*Endpoint)(nil)
+)
+
+// Endpoint is a link endpoint that enables delivery of incoming and outgoing
+// packets to any interested packet sockets.
+//
+// +stateify savable
+type Endpoint struct {
+	nested.Endpoint
+}
+
+// New creates a new packetsocket link endpoint wrapping a lower link endpoint.
+//
+// On ingress, the lower link endpoint must only deliver packets that have
+// a link-layer header set if one is required for the link.
+func New(lower stack.LinkEndpoint) stack.LinkEndpoint {
+	e := &Endpoint{}
+	e.Endpoint.Init(lower, e)
+	return e
+}
+
+// DeliverNetworkPacket implements stack.NetworkDispatcher.
+func (e *Endpoint) DeliverNetworkPacket(protocol tcpip.NetworkProtocolNumber, pkt *stack.PacketBuffer) {
+	e.Endpoint.DeliverLinkPacket(protocol, pkt)
+
+	e.Endpoint.DeliverNetworkPacket(protocol, pkt)
+}
+
+// WritePackets implements stack.LinkEndpoint.
+func (e *Endpoint) WritePackets(pkts stack.PacketBufferList) (int, tcpip.Error) {
+	for _, pkt := range pkts.AsSlice() {
+		e.Endpoint.DeliverLinkPacket(pkt.NetworkProtocolNumber, pkt)
+	}
+
+	return e.Endpoint.WritePackets(pkts)
+}