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/header/mldv2_igmpv3_common.go

@@ -0,0 +1,124 @@
+// 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 header
+
+import (
+	"bytes"
+	"fmt"
+	"time"
+
+	"github.com/sagernet/gvisor/pkg/tcpip"
+)
+
+func mldv2AndIGMPv3QuerierQueryCodeToInterval(code uint8) time.Duration {
+	// MLDv2: As per RFC 3810 section 5.1.19,
+	//
+	//   The Querier's Query Interval Code field specifies the [Query
+	//   Interval] used by the Querier.  The actual interval, called the
+	//   Querier's Query Interval (QQI), is represented in units of seconds,
+	//   and is derived from the Querier's Query Interval Code as follows:
+	//
+	//   If QQIC < 128, QQI = QQIC
+	//
+	//   If QQIC >= 128, QQIC represents a floating-point value as follows:
+	//
+	//       0 1 2 3 4 5 6 7
+	//      +-+-+-+-+-+-+-+-+
+	//      |1| exp | mant  |
+	//      +-+-+-+-+-+-+-+-+
+	//
+	//   QQI = (mant | 0x10) << (exp + 3)
+	//
+	//   Multicast routers that are not the current Querier adopt the QQI
+	//   value from the most recently received Query as their own [Query
+	//   Interval] value, unless that most recently received QQI was zero, in
+	//   which case the receiving routers use the default [Query Interval]
+	//   value specified in section 9.2.
+	//
+	// IGMPv3: As per RFC 3376 section 4.1.7,
+	//
+	//   The Querier's Query Interval Code field specifies the [Query
+	//   Interval] used by the querier.  The actual interval, called the
+	//   Querier's Query Interval (QQI), is represented in units of seconds
+	//   and is derived from the Querier's Query Interval Code as follows:
+	//
+	//   If QQIC < 128, QQI = QQIC
+	//
+	//   If QQIC >= 128, QQIC represents a floating-point value as follows:
+	//
+	//       0 1 2 3 4 5 6 7
+	//      +-+-+-+-+-+-+-+-+
+	//      |1| exp | mant  |
+	//      +-+-+-+-+-+-+-+-+
+	//
+	//   QQI = (mant | 0x10) << (exp + 3)
+	//
+	//   Multicast routers that are not the current querier adopt the QQI
+	//   value from the most recently received Query as their own [Query
+	//   Interval] value, unless that most recently received QQI was zero, in
+	//   which case the receiving routers use the default [Query Interval]
+	//   value specified in section 8.2.
+	interval := time.Duration(code)
+	if interval < 128 {
+		return interval * time.Second
+	}
+
+	const expMask = 0b111
+	const mantBits = 4
+	mant := interval & ((1 << mantBits) - 1)
+	exp := (interval >> mantBits) & expMask
+	return (mant | 0x10) << (exp + 3) * time.Second
+}
+
+// MakeAddressIterator returns an AddressIterator.
+func MakeAddressIterator(addressSize int, buf *bytes.Buffer) AddressIterator {
+	return AddressIterator{addressSize: addressSize, buf: buf}
+}
+
+// AddressIterator is an iterator over IPv6 addresses.
+type AddressIterator struct {
+	addressSize int
+	buf         *bytes.Buffer
+}
+
+// Done indicates that the iterator has been exhausted/has no more elements.
+func (it *AddressIterator) Done() bool {
+	return it.buf.Len() == 0
+}
+
+// Next returns the next address in the iterator.
+//
+// Returns false if the iterator has been exhausted.
+func (it *AddressIterator) Next() (tcpip.Address, bool) {
+	if it.Done() {
+		var emptyAddress tcpip.Address
+		return emptyAddress, false
+	}
+
+	b := it.buf.Next(it.addressSize)
+	if len(b) != it.addressSize {
+		panic(fmt.Sprintf("got len(buf.Next(%d)) = %d, want = %d", it.addressSize, len(b), it.addressSize))
+	}
+
+	return tcpip.AddrFromSlice(b), true
+}
+
+func makeAddressIterator(b []byte, expectedAddresses uint16, addressSize int) (AddressIterator, bool) {
+	expectedLen := int(expectedAddresses) * addressSize
+	if len(b) < expectedLen {
+		return AddressIterator{}, false
+	}
+	return MakeAddressIterator(addressSize, bytes.NewBuffer(b[:expectedLen])), true
+}