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/xdp/xdp_unsafe.go

@@ -0,0 +1,123 @@
+// 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 xdp
+
+import (
+	"fmt"
+	"reflect"
+	"unsafe"
+
+	"github.com/sagernet/gvisor/pkg/atomicbitops"
+	"golang.org/x/sys/unix"
+)
+
+func registerUMEM(fd int, reg unix.XDPUmemReg) error {
+	if _, _, errno := unix.Syscall6(unix.SYS_SETSOCKOPT, uintptr(fd), unix.SOL_XDP, unix.XDP_UMEM_REG, uintptr(unsafe.Pointer(&reg)), unsafe.Sizeof(reg), 0); errno != 0 {
+		return fmt.Errorf("failed to setsockopt(XDP_UMEM_REG): errno %d", errno)
+	}
+	return nil
+}
+
+func getOffsets(fd int) (unix.XDPMmapOffsets, error) {
+	var off unix.XDPMmapOffsets
+	size := unsafe.Sizeof(off)
+	if _, _, errno := unix.Syscall6(unix.SYS_GETSOCKOPT, uintptr(fd), unix.SOL_XDP, unix.XDP_MMAP_OFFSETS, uintptr(unsafe.Pointer(&off)), uintptr(unsafe.Pointer(&size)), 0); errno != 0 {
+		return unix.XDPMmapOffsets{}, fmt.Errorf("failed to get offsets: %v", errno)
+	} else if unsafe.Sizeof(off) != size {
+		return unix.XDPMmapOffsets{}, fmt.Errorf("expected optlen of %d, but found %d", unsafe.Sizeof(off), size)
+	}
+	return off, nil
+}
+
+func sliceBackingPointer(slice []byte) uintptr {
+	return uintptr(unsafe.Pointer(&slice[0]))
+}
+
+func sizeOfFillQueueDesc() uint64 {
+	return uint64(unsafe.Sizeof(uint64(0)))
+}
+
+func sizeOfRXQueueDesc() uint64 {
+	return uint64(unsafe.Sizeof(unix.XDPDesc{}))
+}
+
+func sizeOfCompletionQueueDesc() uint64 {
+	return uint64(unsafe.Sizeof(uint64(0)))
+}
+
+func sizeOfTXQueueDesc() uint64 {
+	return uint64(unsafe.Sizeof(unix.XDPDesc{}))
+}
+
+func (fq *FillQueue) init(off unix.XDPMmapOffsets, opts Opts) {
+	fillQueueRingHdr := (*reflect.SliceHeader)(unsafe.Pointer(&fq.ring))
+	fillQueueRingHdr.Data = uintptr(unsafe.Pointer(&fq.mem[off.Fr.Desc]))
+	fillQueueRingHdr.Len = int(opts.NDescriptors)
+	fillQueueRingHdr.Cap = fillQueueRingHdr.Len
+	fq.producer = (*atomicbitops.Uint32)(unsafe.Pointer(&fq.mem[off.Fr.Producer]))
+	fq.consumer = (*atomicbitops.Uint32)(unsafe.Pointer(&fq.mem[off.Fr.Consumer]))
+	fq.flags = (*atomicbitops.Uint32)(unsafe.Pointer(&fq.mem[off.Fr.Flags]))
+}
+
+func (rq *RXQueue) init(off unix.XDPMmapOffsets, opts Opts) {
+	rxQueueRingHdr := (*reflect.SliceHeader)(unsafe.Pointer(&rq.ring))
+	rxQueueRingHdr.Data = uintptr(unsafe.Pointer(&rq.mem[off.Rx.Desc]))
+	rxQueueRingHdr.Len = int(opts.NDescriptors)
+	rxQueueRingHdr.Cap = rxQueueRingHdr.Len
+	rq.producer = (*atomicbitops.Uint32)(unsafe.Pointer(&rq.mem[off.Rx.Producer]))
+	rq.consumer = (*atomicbitops.Uint32)(unsafe.Pointer(&rq.mem[off.Rx.Consumer]))
+	rq.flags = (*atomicbitops.Uint32)(unsafe.Pointer(&rq.mem[off.Rx.Flags]))
+	// These probably don't have to be atomic, but we're only loading once
+	// so better safe than sorry.
+	rq.cachedProducer = rq.producer.Load()
+	rq.cachedConsumer = rq.consumer.Load()
+}
+
+func (cq *CompletionQueue) init(off unix.XDPMmapOffsets, opts Opts) {
+	completionQueueRingHdr := (*reflect.SliceHeader)(unsafe.Pointer(&cq.ring))
+	completionQueueRingHdr.Data = uintptr(unsafe.Pointer(&cq.mem[off.Cr.Desc]))
+	completionQueueRingHdr.Len = int(opts.NDescriptors)
+	completionQueueRingHdr.Cap = completionQueueRingHdr.Len
+	cq.producer = (*atomicbitops.Uint32)(unsafe.Pointer(&cq.mem[off.Cr.Producer]))
+	cq.consumer = (*atomicbitops.Uint32)(unsafe.Pointer(&cq.mem[off.Cr.Consumer]))
+	cq.flags = (*atomicbitops.Uint32)(unsafe.Pointer(&cq.mem[off.Cr.Flags]))
+	// These probably don't have to be atomic, but we're only loading once
+	// so better safe than sorry.
+	cq.cachedProducer = cq.producer.Load()
+	cq.cachedConsumer = cq.consumer.Load()
+}
+
+func (tq *TXQueue) init(off unix.XDPMmapOffsets, opts Opts) {
+	txQueueRingHdr := (*reflect.SliceHeader)(unsafe.Pointer(&tq.ring))
+	txQueueRingHdr.Data = uintptr(unsafe.Pointer(&tq.mem[off.Tx.Desc]))
+	txQueueRingHdr.Len = int(opts.NDescriptors)
+	txQueueRingHdr.Cap = txQueueRingHdr.Len
+	tq.producer = (*atomicbitops.Uint32)(unsafe.Pointer(&tq.mem[off.Tx.Producer]))
+	tq.consumer = (*atomicbitops.Uint32)(unsafe.Pointer(&tq.mem[off.Tx.Consumer]))
+	tq.flags = (*atomicbitops.Uint32)(unsafe.Pointer(&tq.mem[off.Tx.Flags]))
+}
+
+// kick notifies the kernel that there are packets to transmit.
+func (tq *TXQueue) kick() error {
+	if tq.flags.RacyLoad()&unix.XDP_RING_NEED_WAKEUP == 0 {
+		return nil
+	}
+
+	var msg unix.Msghdr
+	if _, _, errno := unix.Syscall6(unix.SYS_SENDMSG, uintptr(tq.sockfd), uintptr(unsafe.Pointer(&msg)), unix.MSG_DONTWAIT|unix.MSG_NOSIGNAL, 0, 0, 0); errno != 0 {
+		return fmt.Errorf("failed to kick TX queue via sendmsg: errno %d", errno)
+	}
+	return nil
+}