Recover context json for go1.20

.github/workflows/debug.yml

@@ -30,38 +30,6 @@ jobs:
       - name: Build
         run: |
           make test
-  build_go118:
-    name: Linux Debug build (Go 1.18)
-    runs-on: ubuntu-latest
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v4
-        with:
-          fetch-depth: 0
-      - name: Setup Go
-        uses: actions/setup-go@v4
-        with:
-          go-version: ~1.18
-        continue-on-error: true
-      - name: Build
-        run: |
-          make test
-  build_go119:
-    name: Linux Debug build (Go 1.19)
-    runs-on: ubuntu-latest
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v4
-        with:
-          fetch-depth: 0
-      - name: Setup Go
-        uses: actions/setup-go@v4
-        with:
-          go-version: ~1.19
-        continue-on-error: true
-      - name: Build
-        run: |
-          make test
   build_go120:
     name: Linux Debug build (Go 1.20)
     runs-on: ubuntu-latest

common/binary/README.md

@@ -0,0 +1,3 @@
+# binary
+
+mod from go 1.22.3

common/binary/binary.go

@@ -0,0 +1,817 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package binary implements simple translation between numbers and byte
+// sequences and encoding and decoding of varints.
+//
+// Numbers are translated by reading and writing fixed-size values.
+// A fixed-size value is either a fixed-size arithmetic
+// type (bool, int8, uint8, int16, float32, complex64, ...)
+// or an array or struct containing only fixed-size values.
+//
+// The varint functions encode and decode single integer values using
+// a variable-length encoding; smaller values require fewer bytes.
+// For a specification, see
+// https://developers.google.com/protocol-buffers/docs/encoding.
+//
+// This package favors simplicity over efficiency. Clients that require
+// high-performance serialization, especially for large data structures,
+// should look at more advanced solutions such as the [encoding/gob]
+// package or [google.golang.org/protobuf] for protocol buffers.
+package binary
+
+import (
+	"errors"
+	"io"
+	"math"
+	"reflect"
+	"sync"
+)
+
+// A ByteOrder specifies how to convert byte slices into
+// 16-, 32-, or 64-bit unsigned integers.
+//
+// It is implemented by [LittleEndian], [BigEndian], and [NativeEndian].
+type ByteOrder interface {
+	Uint16([]byte) uint16
+	Uint32([]byte) uint32
+	Uint64([]byte) uint64
+	PutUint16([]byte, uint16)
+	PutUint32([]byte, uint32)
+	PutUint64([]byte, uint64)
+	String() string
+}
+
+// AppendByteOrder specifies how to append 16-, 32-, or 64-bit unsigned integers
+// into a byte slice.
+//
+// It is implemented by [LittleEndian], [BigEndian], and [NativeEndian].
+type AppendByteOrder interface {
+	AppendUint16([]byte, uint16) []byte
+	AppendUint32([]byte, uint32) []byte
+	AppendUint64([]byte, uint64) []byte
+	String() string
+}
+
+// LittleEndian is the little-endian implementation of [ByteOrder] and [AppendByteOrder].
+var LittleEndian littleEndian
+
+// BigEndian is the big-endian implementation of [ByteOrder] and [AppendByteOrder].
+var BigEndian bigEndian
+
+type littleEndian struct{}
+
+func (littleEndian) Uint16(b []byte) uint16 {
+	_ = b[1] // bounds check hint to compiler; see golang.org/issue/14808
+	return uint16(b[0]) | uint16(b[1])<<8
+}
+
+func (littleEndian) PutUint16(b []byte, v uint16) {
+	_ = b[1] // early bounds check to guarantee safety of writes below
+	b[0] = byte(v)
+	b[1] = byte(v >> 8)
+}
+
+func (littleEndian) AppendUint16(b []byte, v uint16) []byte {
+	return append(b,
+		byte(v),
+		byte(v>>8),
+	)
+}
+
+func (littleEndian) Uint32(b []byte) uint32 {
+	_ = b[3] // bounds check hint to compiler; see golang.org/issue/14808
+	return uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24
+}
+
+func (littleEndian) PutUint32(b []byte, v uint32) {
+	_ = b[3] // early bounds check to guarantee safety of writes below
+	b[0] = byte(v)
+	b[1] = byte(v >> 8)
+	b[2] = byte(v >> 16)
+	b[3] = byte(v >> 24)
+}
+
+func (littleEndian) AppendUint32(b []byte, v uint32) []byte {
+	return append(b,
+		byte(v),
+		byte(v>>8),
+		byte(v>>16),
+		byte(v>>24),
+	)
+}
+
+func (littleEndian) Uint64(b []byte) uint64 {
+	_ = b[7] // bounds check hint to compiler; see golang.org/issue/14808
+	return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 |
+		uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56
+}
+
+func (littleEndian) PutUint64(b []byte, v uint64) {
+	_ = b[7] // early bounds check to guarantee safety of writes below
+	b[0] = byte(v)
+	b[1] = byte(v >> 8)
+	b[2] = byte(v >> 16)
+	b[3] = byte(v >> 24)
+	b[4] = byte(v >> 32)
+	b[5] = byte(v >> 40)
+	b[6] = byte(v >> 48)
+	b[7] = byte(v >> 56)
+}
+
+func (littleEndian) AppendUint64(b []byte, v uint64) []byte {
+	return append(b,
+		byte(v),
+		byte(v>>8),
+		byte(v>>16),
+		byte(v>>24),
+		byte(v>>32),
+		byte(v>>40),
+		byte(v>>48),
+		byte(v>>56),
+	)
+}
+
+func (littleEndian) String() string { return "LittleEndian" }
+
+func (littleEndian) GoString() string { return "binary.LittleEndian" }
+
+type bigEndian struct{}
+
+func (bigEndian) Uint16(b []byte) uint16 {
+	_ = b[1] // bounds check hint to compiler; see golang.org/issue/14808
+	return uint16(b[1]) | uint16(b[0])<<8
+}
+
+func (bigEndian) PutUint16(b []byte, v uint16) {
+	_ = b[1] // early bounds check to guarantee safety of writes below
+	b[0] = byte(v >> 8)
+	b[1] = byte(v)
+}
+
+func (bigEndian) AppendUint16(b []byte, v uint16) []byte {
+	return append(b,
+		byte(v>>8),
+		byte(v),
+	)
+}
+
+func (bigEndian) Uint32(b []byte) uint32 {
+	_ = b[3] // bounds check hint to compiler; see golang.org/issue/14808
+	return uint32(b[3]) | uint32(b[2])<<8 | uint32(b[1])<<16 | uint32(b[0])<<24
+}
+
+func (bigEndian) PutUint32(b []byte, v uint32) {
+	_ = b[3] // early bounds check to guarantee safety of writes below
+	b[0] = byte(v >> 24)
+	b[1] = byte(v >> 16)
+	b[2] = byte(v >> 8)
+	b[3] = byte(v)
+}
+
+func (bigEndian) AppendUint32(b []byte, v uint32) []byte {
+	return append(b,
+		byte(v>>24),
+		byte(v>>16),
+		byte(v>>8),
+		byte(v),
+	)
+}
+
+func (bigEndian) Uint64(b []byte) uint64 {
+	_ = b[7] // bounds check hint to compiler; see golang.org/issue/14808
+	return uint64(b[7]) | uint64(b[6])<<8 | uint64(b[5])<<16 | uint64(b[4])<<24 |
+		uint64(b[3])<<32 | uint64(b[2])<<40 | uint64(b[1])<<48 | uint64(b[0])<<56
+}
+
+func (bigEndian) PutUint64(b []byte, v uint64) {
+	_ = b[7] // early bounds check to guarantee safety of writes below
+	b[0] = byte(v >> 56)
+	b[1] = byte(v >> 48)
+	b[2] = byte(v >> 40)
+	b[3] = byte(v >> 32)
+	b[4] = byte(v >> 24)
+	b[5] = byte(v >> 16)
+	b[6] = byte(v >> 8)
+	b[7] = byte(v)
+}
+
+func (bigEndian) AppendUint64(b []byte, v uint64) []byte {
+	return append(b,
+		byte(v>>56),
+		byte(v>>48),
+		byte(v>>40),
+		byte(v>>32),
+		byte(v>>24),
+		byte(v>>16),
+		byte(v>>8),
+		byte(v),
+	)
+}
+
+func (bigEndian) String() string { return "BigEndian" }
+
+func (bigEndian) GoString() string { return "binary.BigEndian" }
+
+func (nativeEndian) String() string { return "NativeEndian" }
+
+func (nativeEndian) GoString() string { return "binary.NativeEndian" }
+
+// Read reads structured binary data from r into data.
+// Data must be a pointer to a fixed-size value or a slice
+// of fixed-size values.
+// Bytes read from r are decoded using the specified byte order
+// and written to successive fields of the data.
+// When decoding boolean values, a zero byte is decoded as false, and
+// any other non-zero byte is decoded as true.
+// When reading into structs, the field data for fields with
+// blank (_) field names is skipped; i.e., blank field names
+// may be used for padding.
+// When reading into a struct, all non-blank fields must be exported
+// or Read may panic.
+//
+// The error is [io.EOF] only if no bytes were read.
+// If an [io.EOF] happens after reading some but not all the bytes,
+// Read returns [io.ErrUnexpectedEOF].
+func Read(r io.Reader, order ByteOrder, data any) error {
+	// Fast path for basic types and slices.
+	if n := intDataSize(data); n != 0 {
+		bs := make([]byte, n)
+		if _, err := io.ReadFull(r, bs); err != nil {
+			return err
+		}
+		switch data := data.(type) {
+		case *bool:
+			*data = bs[0] != 0
+		case *int8:
+			*data = int8(bs[0])
+		case *uint8:
+			*data = bs[0]
+		case *int16:
+			*data = int16(order.Uint16(bs))
+		case *uint16:
+			*data = order.Uint16(bs)
+		case *int32:
+			*data = int32(order.Uint32(bs))
+		case *uint32:
+			*data = order.Uint32(bs)
+		case *int64:
+			*data = int64(order.Uint64(bs))
+		case *uint64:
+			*data = order.Uint64(bs)
+		case *float32:
+			*data = math.Float32frombits(order.Uint32(bs))
+		case *float64:
+			*data = math.Float64frombits(order.Uint64(bs))
+		case []bool:
+			for i, x := range bs { // Easier to loop over the input for 8-bit values.
+				data[i] = x != 0
+			}
+		case []int8:
+			for i, x := range bs {
+				data[i] = int8(x)
+			}
+		case []uint8:
+			copy(data, bs)
+		case []int16:
+			for i := range data {
+				data[i] = int16(order.Uint16(bs[2*i:]))
+			}
+		case []uint16:
+			for i := range data {
+				data[i] = order.Uint16(bs[2*i:])
+			}
+		case []int32:
+			for i := range data {
+				data[i] = int32(order.Uint32(bs[4*i:]))
+			}
+		case []uint32:
+			for i := range data {
+				data[i] = order.Uint32(bs[4*i:])
+			}
+		case []int64:
+			for i := range data {
+				data[i] = int64(order.Uint64(bs[8*i:]))
+			}
+		case []uint64:
+			for i := range data {
+				data[i] = order.Uint64(bs[8*i:])
+			}
+		case []float32:
+			for i := range data {
+				data[i] = math.Float32frombits(order.Uint32(bs[4*i:]))
+			}
+		case []float64:
+			for i := range data {
+				data[i] = math.Float64frombits(order.Uint64(bs[8*i:]))
+			}
+		default:
+			n = 0 // fast path doesn't apply
+		}
+		if n != 0 {
+			return nil
+		}
+	}
+
+	// Fallback to reflect-based decoding.
+	v := reflect.ValueOf(data)
+	size := -1
+	switch v.Kind() {
+	case reflect.Pointer:
+		v = v.Elem()
+		size = dataSize(v)
+	case reflect.Slice:
+		size = dataSize(v)
+	}
+	if size < 0 {
+		return errors.New("binary.Read: invalid type " + reflect.TypeOf(data).String())
+	}
+	d := &decoder{order: order, buf: make([]byte, size)}
+	if _, err := io.ReadFull(r, d.buf); err != nil {
+		return err
+	}
+	d.value(v)
+	return nil
+}
+
+// Write writes the binary representation of data into w.
+// Data must be a fixed-size value or a slice of fixed-size
+// values, or a pointer to such data.
+// Boolean values encode as one byte: 1 for true, and 0 for false.
+// Bytes written to w are encoded using the specified byte order
+// and read from successive fields of the data.
+// When writing structs, zero values are written for fields
+// with blank (_) field names.
+func Write(w io.Writer, order ByteOrder, data any) error {
+	// Fast path for basic types and slices.
+	if n := intDataSize(data); n != 0 {
+		bs := make([]byte, n)
+		switch v := data.(type) {
+		case *bool:
+			if *v {
+				bs[0] = 1
+			} else {
+				bs[0] = 0
+			}
+		case bool:
+			if v {
+				bs[0] = 1
+			} else {
+				bs[0] = 0
+			}
+		case []bool:
+			for i, x := range v {
+				if x {
+					bs[i] = 1
+				} else {
+					bs[i] = 0
+				}
+			}
+		case *int8:
+			bs[0] = byte(*v)
+		case int8:
+			bs[0] = byte(v)
+		case []int8:
+			for i, x := range v {
+				bs[i] = byte(x)
+			}
+		case *uint8:
+			bs[0] = *v
+		case uint8:
+			bs[0] = v
+		case []uint8:
+			bs = v
+		case *int16:
+			order.PutUint16(bs, uint16(*v))
+		case int16:
+			order.PutUint16(bs, uint16(v))
+		case []int16:
+			for i, x := range v {
+				order.PutUint16(bs[2*i:], uint16(x))
+			}
+		case *uint16:
+			order.PutUint16(bs, *v)
+		case uint16:
+			order.PutUint16(bs, v)
+		case []uint16:
+			for i, x := range v {
+				order.PutUint16(bs[2*i:], x)
+			}
+		case *int32:
+			order.PutUint32(bs, uint32(*v))
+		case int32:
+			order.PutUint32(bs, uint32(v))
+		case []int32:
+			for i, x := range v {
+				order.PutUint32(bs[4*i:], uint32(x))
+			}
+		case *uint32:
+			order.PutUint32(bs, *v)
+		case uint32:
+			order.PutUint32(bs, v)
+		case []uint32:
+			for i, x := range v {
+				order.PutUint32(bs[4*i:], x)
+			}
+		case *int64:
+			order.PutUint64(bs, uint64(*v))
+		case int64:
+			order.PutUint64(bs, uint64(v))
+		case []int64:
+			for i, x := range v {
+				order.PutUint64(bs[8*i:], uint64(x))
+			}
+		case *uint64:
+			order.PutUint64(bs, *v)
+		case uint64:
+			order.PutUint64(bs, v)
+		case []uint64:
+			for i, x := range v {
+				order.PutUint64(bs[8*i:], x)
+			}
+		case *float32:
+			order.PutUint32(bs, math.Float32bits(*v))
+		case float32:
+			order.PutUint32(bs, math.Float32bits(v))
+		case []float32:
+			for i, x := range v {
+				order.PutUint32(bs[4*i:], math.Float32bits(x))
+			}
+		case *float64:
+			order.PutUint64(bs, math.Float64bits(*v))
+		case float64:
+			order.PutUint64(bs, math.Float64bits(v))
+		case []float64:
+			for i, x := range v {
+				order.PutUint64(bs[8*i:], math.Float64bits(x))
+			}
+		}
+		_, err := w.Write(bs)
+		return err
+	}
+
+	// Fallback to reflect-based encoding.
+	v := reflect.Indirect(reflect.ValueOf(data))
+	size := dataSize(v)
+	if size < 0 {
+		return errors.New("binary.Write: some values are not fixed-sized in type " + reflect.TypeOf(data).String())
+	}
+	buf := make([]byte, size)
+	e := &encoder{order: order, buf: buf}
+	e.value(v)
+	_, err := w.Write(buf)
+	return err
+}
+
+// Size returns how many bytes [Write] would generate to encode the value v, which
+// must be a fixed-size value or a slice of fixed-size values, or a pointer to such data.
+// If v is neither of these, Size returns -1.
+func Size(v any) int {
+	return dataSize(reflect.Indirect(reflect.ValueOf(v)))
+}
+
+var structSize sync.Map // map[reflect.Type]int
+
+// dataSize returns the number of bytes the actual data represented by v occupies in memory.
+// For compound structures, it sums the sizes of the elements. Thus, for instance, for a slice
+// it returns the length of the slice times the element size and does not count the memory
+// occupied by the header. If the type of v is not acceptable, dataSize returns -1.
+func dataSize(v reflect.Value) int {
+	switch v.Kind() {
+	case reflect.Slice:
+		if s := sizeof(v.Type().Elem()); s >= 0 {
+			return s * v.Len()
+		}
+
+	case reflect.Struct:
+		t := v.Type()
+		if size, ok := structSize.Load(t); ok {
+			return size.(int)
+		}
+		size := sizeof(t)
+		structSize.Store(t, size)
+		return size
+
+	default:
+		if v.IsValid() {
+			return sizeof(v.Type())
+		}
+	}
+
+	return -1
+}
+
+// sizeof returns the size >= 0 of variables for the given type or -1 if the type is not acceptable.
+func sizeof(t reflect.Type) int {
+	switch t.Kind() {
+	case reflect.Array:
+		if s := sizeof(t.Elem()); s >= 0 {
+			return s * t.Len()
+		}
+
+	case reflect.Struct:
+		sum := 0
+		for i, n := 0, t.NumField(); i < n; i++ {
+			s := sizeof(t.Field(i).Type)
+			if s < 0 {
+				return -1
+			}
+			sum += s
+		}
+		return sum
+
+	case reflect.Bool,
+		reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64,
+		reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64,
+		reflect.Float32, reflect.Float64, reflect.Complex64, reflect.Complex128:
+		return int(t.Size())
+	}
+
+	return -1
+}
+
+type coder struct {
+	order  ByteOrder
+	buf    []byte
+	offset int
+}
+
+type (
+	decoder coder
+	encoder coder
+)
+
+func (d *decoder) bool() bool {
+	x := d.buf[d.offset]
+	d.offset++
+	return x != 0
+}
+
+func (e *encoder) bool(x bool) {
+	if x {
+		e.buf[e.offset] = 1
+	} else {
+		e.buf[e.offset] = 0
+	}
+	e.offset++
+}
+
+func (d *decoder) uint8() uint8 {
+	x := d.buf[d.offset]
+	d.offset++
+	return x
+}
+
+func (e *encoder) uint8(x uint8) {
+	e.buf[e.offset] = x
+	e.offset++
+}
+
+func (d *decoder) uint16() uint16 {
+	x := d.order.Uint16(d.buf[d.offset : d.offset+2])
+	d.offset += 2
+	return x
+}
+
+func (e *encoder) uint16(x uint16) {
+	e.order.PutUint16(e.buf[e.offset:e.offset+2], x)
+	e.offset += 2
+}
+
+func (d *decoder) uint32() uint32 {
+	x := d.order.Uint32(d.buf[d.offset : d.offset+4])
+	d.offset += 4
+	return x
+}
+
+func (e *encoder) uint32(x uint32) {
+	e.order.PutUint32(e.buf[e.offset:e.offset+4], x)
+	e.offset += 4
+}
+
+func (d *decoder) uint64() uint64 {
+	x := d.order.Uint64(d.buf[d.offset : d.offset+8])
+	d.offset += 8
+	return x
+}
+
+func (e *encoder) uint64(x uint64) {
+	e.order.PutUint64(e.buf[e.offset:e.offset+8], x)
+	e.offset += 8
+}
+
+func (d *decoder) int8() int8 { return int8(d.uint8()) }
+
+func (e *encoder) int8(x int8) { e.uint8(uint8(x)) }
+
+func (d *decoder) int16() int16 { return int16(d.uint16()) }
+
+func (e *encoder) int16(x int16) { e.uint16(uint16(x)) }
+
+func (d *decoder) int32() int32 { return int32(d.uint32()) }
+
+func (e *encoder) int32(x int32) { e.uint32(uint32(x)) }
+
+func (d *decoder) int64() int64 { return int64(d.uint64()) }
+
+func (e *encoder) int64(x int64) { e.uint64(uint64(x)) }
+
+func (d *decoder) value(v reflect.Value) {
+	switch v.Kind() {
+	case reflect.Array:
+		l := v.Len()
+		for i := 0; i < l; i++ {
+			d.value(v.Index(i))
+		}
+
+	case reflect.Struct:
+		t := v.Type()
+		l := v.NumField()
+		for i := 0; i < l; i++ {
+			// Note: Calling v.CanSet() below is an optimization.
+			// It would be sufficient to check the field name,
+			// but creating the StructField info for each field is
+			// costly (run "go test -bench=ReadStruct" and compare
+			// results when making changes to this code).
+			if v := v.Field(i); v.CanSet() || t.Field(i).Name != "_" {
+				d.value(v)
+			} else {
+				d.skip(v)
+			}
+		}
+
+	case reflect.Slice:
+		l := v.Len()
+		for i := 0; i < l; i++ {
+			d.value(v.Index(i))
+		}
+
+	case reflect.Bool:
+		v.SetBool(d.bool())
+
+	case reflect.Int8:
+		v.SetInt(int64(d.int8()))
+	case reflect.Int16:
+		v.SetInt(int64(d.int16()))
+	case reflect.Int32:
+		v.SetInt(int64(d.int32()))
+	case reflect.Int64:
+		v.SetInt(d.int64())
+
+	case reflect.Uint8:
+		v.SetUint(uint64(d.uint8()))
+	case reflect.Uint16:
+		v.SetUint(uint64(d.uint16()))
+	case reflect.Uint32:
+		v.SetUint(uint64(d.uint32()))
+	case reflect.Uint64:
+		v.SetUint(d.uint64())
+
+	case reflect.Float32:
+		v.SetFloat(float64(math.Float32frombits(d.uint32())))
+	case reflect.Float64:
+		v.SetFloat(math.Float64frombits(d.uint64()))
+
+	case reflect.Complex64:
+		v.SetComplex(complex(
+			float64(math.Float32frombits(d.uint32())),
+			float64(math.Float32frombits(d.uint32())),
+		))
+	case reflect.Complex128:
+		v.SetComplex(complex(
+			math.Float64frombits(d.uint64()),
+			math.Float64frombits(d.uint64()),
+		))
+	}
+}
+
+func (e *encoder) value(v reflect.Value) {
+	switch v.Kind() {
+	case reflect.Array:
+		l := v.Len()
+		for i := 0; i < l; i++ {
+			e.value(v.Index(i))
+		}
+
+	case reflect.Struct:
+		t := v.Type()
+		l := v.NumField()
+		for i := 0; i < l; i++ {
+			// see comment for corresponding code in decoder.value()
+			if v := v.Field(i); v.CanSet() || t.Field(i).Name != "_" {
+				e.value(v)
+			} else {
+				e.skip(v)
+			}
+		}
+
+	case reflect.Slice:
+		l := v.Len()
+		for i := 0; i < l; i++ {
+			e.value(v.Index(i))
+		}
+
+	case reflect.Bool:
+		e.bool(v.Bool())
+
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		switch v.Type().Kind() {
+		case reflect.Int8:
+			e.int8(int8(v.Int()))
+		case reflect.Int16:
+			e.int16(int16(v.Int()))
+		case reflect.Int32:
+			e.int32(int32(v.Int()))
+		case reflect.Int64:
+			e.int64(v.Int())
+		}
+
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		switch v.Type().Kind() {
+		case reflect.Uint8:
+			e.uint8(uint8(v.Uint()))
+		case reflect.Uint16:
+			e.uint16(uint16(v.Uint()))
+		case reflect.Uint32:
+			e.uint32(uint32(v.Uint()))
+		case reflect.Uint64:
+			e.uint64(v.Uint())
+		}
+
+	case reflect.Float32, reflect.Float64:
+		switch v.Type().Kind() {
+		case reflect.Float32:
+			e.uint32(math.Float32bits(float32(v.Float())))
+		case reflect.Float64:
+			e.uint64(math.Float64bits(v.Float()))
+		}
+
+	case reflect.Complex64, reflect.Complex128:
+		switch v.Type().Kind() {
+		case reflect.Complex64:
+			x := v.Complex()
+			e.uint32(math.Float32bits(float32(real(x))))
+			e.uint32(math.Float32bits(float32(imag(x))))
+		case reflect.Complex128:
+			x := v.Complex()
+			e.uint64(math.Float64bits(real(x)))
+			e.uint64(math.Float64bits(imag(x)))
+		}
+	}
+}
+
+func (d *decoder) skip(v reflect.Value) {
+	d.offset += dataSize(v)
+}
+
+func (e *encoder) skip(v reflect.Value) {
+	n := dataSize(v)
+	zero := e.buf[e.offset : e.offset+n]
+	for i := range zero {
+		zero[i] = 0
+	}
+	e.offset += n
+}
+
+// intDataSize returns the size of the data required to represent the data when encoded.
+// It returns zero if the type cannot be implemented by the fast path in Read or Write.
+func intDataSize(data any) int {
+	switch data := data.(type) {
+	case bool, int8, uint8, *bool, *int8, *uint8:
+		return 1
+	case []bool:
+		return len(data)
+	case []int8:
+		return len(data)
+	case []uint8:
+		return len(data)
+	case int16, uint16, *int16, *uint16:
+		return 2
+	case []int16:
+		return 2 * len(data)
+	case []uint16:
+		return 2 * len(data)
+	case int32, uint32, *int32, *uint32:
+		return 4
+	case []int32:
+		return 4 * len(data)
+	case []uint32:
+		return 4 * len(data)
+	case int64, uint64, *int64, *uint64:
+		return 8
+	case []int64:
+		return 8 * len(data)
+	case []uint64:
+		return 8 * len(data)
+	case float32, *float32:
+		return 4
+	case float64, *float64:
+		return 8
+	case []float32:
+		return 4 * len(data)
+	case []float64:
+		return 8 * len(data)
+	}
+	return 0
+}

common/binary/native_endian_big.go

@@ -0,0 +1,14 @@
+// Copyright 2023 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build armbe || arm64be || m68k || mips || mips64 || mips64p32 || ppc || ppc64 || s390 || s390x || shbe || sparc || sparc64
+
+package binary
+
+type nativeEndian struct {
+	bigEndian
+}
+
+// NativeEndian is the native-endian implementation of [ByteOrder] and [AppendByteOrder].
+var NativeEndian nativeEndian

common/binary/native_endian_little.go

@@ -0,0 +1,14 @@
+// Copyright 2023 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build 386 || amd64 || amd64p32 || alpha || arm || arm64 || loong64 || mipsle || mips64le || mips64p32le || nios2 || ppc64le || riscv || riscv64 || sh || wasm
+
+package binary
+
+type nativeEndian struct {
+	littleEndian
+}
+
+// NativeEndian is the native-endian implementation of [ByteOrder] and [AppendByteOrder].
+var NativeEndian nativeEndian

common/binary/variant_data.go

@@ -0,0 +1,305 @@
+package binary
+
+import (
+	"bufio"
+	"errors"
+	"io"
+	"reflect"
+
+	E "github.com/sagernet/sing/common/exceptions"
+)
+
+func ReadDataSlice(r *bufio.Reader, order ByteOrder, data ...any) error {
+	for index, item := range data {
+		err := ReadData(r, order, item)
+		if err != nil {
+			return E.Cause(err, "[", index, "]")
+		}
+	}
+	return nil
+}
+
+func ReadData(r *bufio.Reader, order ByteOrder, data any) error {
+	switch dataPtr := data.(type) {
+	case *[]uint8:
+		bytesLen, err := ReadUvarint(r)
+		if err != nil {
+			return E.Cause(err, "bytes length")
+		}
+		newBytes := make([]uint8, bytesLen)
+		_, err = io.ReadFull(r, newBytes)
+		if err != nil {
+			return E.Cause(err, "bytes value")
+		}
+		*dataPtr = newBytes
+	default:
+		if intBaseDataSize(data) != 0 {
+			return Read(r, order, data)
+		}
+	}
+	dataValue := reflect.ValueOf(data)
+	if dataValue.Kind() == reflect.Pointer {
+		dataValue = dataValue.Elem()
+	}
+	return readData(r, order, dataValue)
+}
+
+func readData(r *bufio.Reader, order ByteOrder, data reflect.Value) error {
+	switch data.Kind() {
+	case reflect.Pointer:
+		pointerValue, err := r.ReadByte()
+		if err != nil {
+			return err
+		}
+		if pointerValue == 0 {
+			data.SetZero()
+			return nil
+		}
+		if data.IsNil() {
+			data.Set(reflect.New(data.Type().Elem()))
+		}
+		return readData(r, order, data.Elem())
+	case reflect.String:
+		stringLength, err := ReadUvarint(r)
+		if err != nil {
+			return E.Cause(err, "string length")
+		}
+		if stringLength == 0 {
+			data.SetZero()
+		} else {
+			stringData := make([]byte, stringLength)
+			_, err = io.ReadFull(r, stringData)
+			if err != nil {
+				return E.Cause(err, "string value")
+			}
+			data.SetString(string(stringData))
+		}
+	case reflect.Array:
+		arrayLen := data.Len()
+		for i := 0; i < arrayLen; i++ {
+			err := readData(r, order, data.Index(i))
+			if err != nil {
+				return E.Cause(err, "[", i, "]")
+			}
+		}
+	case reflect.Slice:
+		sliceLength, err := ReadUvarint(r)
+		if err != nil {
+			return E.Cause(err, "slice length")
+		}
+		if !data.IsNil() && data.Cap() >= int(sliceLength) {
+			data.SetLen(int(sliceLength))
+		} else if sliceLength > 0 {
+			data.Set(reflect.MakeSlice(data.Type(), int(sliceLength), int(sliceLength)))
+		}
+		if sliceLength > 0 {
+			if data.Type().Elem().Kind() == reflect.Uint8 {
+				_, err = io.ReadFull(r, data.Bytes())
+				if err != nil {
+					return E.Cause(err, "bytes value")
+				}
+			} else {
+				for index := 0; index < int(sliceLength); index++ {
+					err = readData(r, order, data.Index(index))
+					if err != nil {
+						return E.Cause(err, "[", index, "]")
+					}
+				}
+			}
+		}
+	case reflect.Map:
+		mapLength, err := ReadUvarint(r)
+		if err != nil {
+			return E.Cause(err, "map length")
+		}
+		data.Set(reflect.MakeMap(data.Type()))
+		for index := 0; index < int(mapLength); index++ {
+			key := reflect.New(data.Type().Key()).Elem()
+			err = readData(r, order, key)
+			if err != nil {
+				return E.Cause(err, "[", index, "].key")
+			}
+			value := reflect.New(data.Type().Elem()).Elem()
+			err = readData(r, order, value)
+			if err != nil {
+				return E.Cause(err, "[", index, "].value")
+			}
+			data.SetMapIndex(key, value)
+		}
+	case reflect.Struct:
+		fieldType := data.Type()
+		fieldLen := data.NumField()
+		for i := 0; i < fieldLen; i++ {
+			field := data.Field(i)
+			fieldName := fieldType.Field(i).Name
+			if field.CanSet() || fieldName != "_" {
+				err := readData(r, order, field)
+				if err != nil {
+					return E.Cause(err, fieldName)
+				}
+			}
+		}
+	default:
+		size := dataSize(data)
+		if size < 0 {
+			return errors.New("invalid type " + reflect.TypeOf(data).String())
+		}
+		d := &decoder{order: order, buf: make([]byte, size)}
+		_, err := io.ReadFull(r, d.buf)
+		if err != nil {
+			return err
+		}
+		d.value(data)
+	}
+	return nil
+}
+
+func WriteDataSlice(writer *bufio.Writer, order ByteOrder, data ...any) error {
+	for index, item := range data {
+		err := WriteData(writer, order, item)
+		if err != nil {
+			return E.Cause(err, "[", index, "]")
+		}
+	}
+	return nil
+}
+
+func WriteData(writer *bufio.Writer, order ByteOrder, data any) error {
+	switch dataPtr := data.(type) {
+	case []uint8:
+		_, err := writer.Write(AppendUvarint(writer.AvailableBuffer(), uint64(len(dataPtr))))
+		if err != nil {
+			return E.Cause(err, "bytes length")
+		}
+		_, err = writer.Write(dataPtr)
+		if err != nil {
+			return E.Cause(err, "bytes value")
+		}
+	default:
+		if intBaseDataSize(data) != 0 {
+			return Write(writer, order, data)
+		}
+	}
+	return writeData(writer, order, reflect.Indirect(reflect.ValueOf(data)))
+}
+
+func writeData(writer *bufio.Writer, order ByteOrder, data reflect.Value) error {
+	switch data.Kind() {
+	case reflect.Pointer:
+		if data.IsNil() {
+			err := writer.WriteByte(0)
+			if err != nil {
+				return err
+			}
+		} else {
+			err := writer.WriteByte(1)
+			if err != nil {
+				return err
+			}
+			return writeData(writer, order, data.Elem())
+		}
+	case reflect.String:
+		stringValue := data.String()
+		_, err := writer.Write(AppendUvarint(writer.AvailableBuffer(), uint64(len(stringValue))))
+		if err != nil {
+			return E.Cause(err, "string length")
+		}
+		if stringValue != "" {
+			_, err = writer.WriteString(stringValue)
+			if err != nil {
+				return E.Cause(err, "string value")
+			}
+		}
+	case reflect.Array:
+		dataLen := data.Len()
+		for i := 0; i < dataLen; i++ {
+			err := writeData(writer, order, data.Index(i))
+			if err != nil {
+				return E.Cause(err, "[", i, "]")
+			}
+		}
+	case reflect.Slice:
+		dataLen := data.Len()
+		_, err := writer.Write(AppendUvarint(writer.AvailableBuffer(), uint64(dataLen)))
+		if err != nil {
+			return E.Cause(err, "slice length")
+		}
+		if dataLen > 0 {
+			if data.Type().Elem().Kind() == reflect.Uint8 {
+				_, err = writer.Write(data.Bytes())
+				if err != nil {
+					return E.Cause(err, "bytes value")
+				}
+			} else {
+				for i := 0; i < dataLen; i++ {
+					err = writeData(writer, order, data.Index(i))
+					if err != nil {
+						return E.Cause(err, "[", i, "]")
+					}
+				}
+			}
+		}
+	case reflect.Map:
+		dataLen := data.Len()
+		_, err := writer.Write(AppendUvarint(writer.AvailableBuffer(), uint64(dataLen)))
+		if err != nil {
+			return E.Cause(err, "map length")
+		}
+		if dataLen > 0 {
+			for index, key := range data.MapKeys() {
+				err = writeData(writer, order, key)
+				if err != nil {
+					return E.Cause(err, "[", index, "].key")
+				}
+				err = writeData(writer, order, data.MapIndex(key))
+				if err != nil {
+					return E.Cause(err, "[", index, "].value")
+				}
+			}
+		}
+	case reflect.Struct:
+		fieldType := data.Type()
+		fieldLen := data.NumField()
+		for i := 0; i < fieldLen; i++ {
+			field := data.Field(i)
+			fieldName := fieldType.Field(i).Name
+			if field.CanSet() || fieldName != "_" {
+				err := writeData(writer, order, field)
+				if err != nil {
+					return E.Cause(err, fieldName)
+				}
+			}
+		}
+	default:
+		size := dataSize(data)
+		if size < 0 {
+			return errors.New("binary.Write: some values are not fixed-sized in type " + data.Type().String())
+		}
+		buf := make([]byte, size)
+		e := &encoder{order: order, buf: buf}
+		e.value(data)
+		_, err := writer.Write(buf)
+		if err != nil {
+			return E.Cause(err, reflect.TypeOf(data).String())
+		}
+	}
+	return nil
+}
+
+func intBaseDataSize(data any) int {
+	switch data.(type) {
+	case bool, int8, uint8:
+		return 1
+	case int16, uint16:
+		return 2
+	case int32, uint32:
+		return 4
+	case int64, uint64:
+		return 8
+	case float32:
+		return 4
+	case float64:
+		return 8
+	}
+	return 0
+}

common/binary/varint.go

@@ -0,0 +1,166 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package binary
+
+// This file implements "varint" encoding of 64-bit integers.
+// The encoding is:
+// - unsigned integers are serialized 7 bits at a time, starting with the
+//   least significant bits
+// - the most significant bit (msb) in each output byte indicates if there
+//   is a continuation byte (msb = 1)
+// - signed integers are mapped to unsigned integers using "zig-zag"
+//   encoding: Positive values x are written as 2*x + 0, negative values
+//   are written as 2*(^x) + 1; that is, negative numbers are complemented
+//   and whether to complement is encoded in bit 0.
+//
+// Design note:
+// At most 10 bytes are needed for 64-bit values. The encoding could
+// be more dense: a full 64-bit value needs an extra byte just to hold bit 63.
+// Instead, the msb of the previous byte could be used to hold bit 63 since we
+// know there can't be more than 64 bits. This is a trivial improvement and
+// would reduce the maximum encoding length to 9 bytes. However, it breaks the
+// invariant that the msb is always the "continuation bit" and thus makes the
+// format incompatible with a varint encoding for larger numbers (say 128-bit).
+
+import (
+	"errors"
+	"io"
+)
+
+// MaxVarintLenN is the maximum length of a varint-encoded N-bit integer.
+const (
+	MaxVarintLen16 = 3
+	MaxVarintLen32 = 5
+	MaxVarintLen64 = 10
+)
+
+// AppendUvarint appends the varint-encoded form of x,
+// as generated by [PutUvarint], to buf and returns the extended buffer.
+func AppendUvarint(buf []byte, x uint64) []byte {
+	for x >= 0x80 {
+		buf = append(buf, byte(x)|0x80)
+		x >>= 7
+	}
+	return append(buf, byte(x))
+}
+
+// PutUvarint encodes a uint64 into buf and returns the number of bytes written.
+// If the buffer is too small, PutUvarint will panic.
+func PutUvarint(buf []byte, x uint64) int {
+	i := 0
+	for x >= 0x80 {
+		buf[i] = byte(x) | 0x80
+		x >>= 7
+		i++
+	}
+	buf[i] = byte(x)
+	return i + 1
+}
+
+// Uvarint decodes a uint64 from buf and returns that value and the
+// number of bytes read (> 0). If an error occurred, the value is 0
+// and the number of bytes n is <= 0 meaning:
+//
+//	n == 0: buf too small
+//	n  < 0: value larger than 64 bits (overflow)
+//	        and -n is the number of bytes read
+func Uvarint(buf []byte) (uint64, int) {
+	var x uint64
+	var s uint
+	for i, b := range buf {
+		if i == MaxVarintLen64 {
+			// Catch byte reads past MaxVarintLen64.
+			// See issue https://golang.org/issues/41185
+			return 0, -(i + 1) // overflow
+		}
+		if b < 0x80 {
+			if i == MaxVarintLen64-1 && b > 1 {
+				return 0, -(i + 1) // overflow
+			}
+			return x | uint64(b)<<s, i + 1
+		}
+		x |= uint64(b&0x7f) << s
+		s += 7
+	}
+	return 0, 0
+}
+
+// AppendVarint appends the varint-encoded form of x,
+// as generated by [PutVarint], to buf and returns the extended buffer.
+func AppendVarint(buf []byte, x int64) []byte {
+	ux := uint64(x) << 1
+	if x < 0 {
+		ux = ^ux
+	}
+	return AppendUvarint(buf, ux)
+}
+
+// PutVarint encodes an int64 into buf and returns the number of bytes written.
+// If the buffer is too small, PutVarint will panic.
+func PutVarint(buf []byte, x int64) int {
+	ux := uint64(x) << 1
+	if x < 0 {
+		ux = ^ux
+	}
+	return PutUvarint(buf, ux)
+}
+
+// Varint decodes an int64 from buf and returns that value and the
+// number of bytes read (> 0). If an error occurred, the value is 0
+// and the number of bytes n is <= 0 with the following meaning:
+//
+//	n == 0: buf too small
+//	n  < 0: value larger than 64 bits (overflow)
+//	        and -n is the number of bytes read
+func Varint(buf []byte) (int64, int) {
+	ux, n := Uvarint(buf) // ok to continue in presence of error
+	x := int64(ux >> 1)
+	if ux&1 != 0 {
+		x = ^x
+	}
+	return x, n
+}
+
+var errOverflow = errors.New("binary: varint overflows a 64-bit integer")
+
+// ReadUvarint reads an encoded unsigned integer from r and returns it as a uint64.
+// The error is [io.EOF] only if no bytes were read.
+// If an [io.EOF] happens after reading some but not all the bytes,
+// ReadUvarint returns [io.ErrUnexpectedEOF].
+func ReadUvarint(r io.ByteReader) (uint64, error) {
+	var x uint64
+	var s uint
+	for i := 0; i < MaxVarintLen64; i++ {
+		b, err := r.ReadByte()
+		if err != nil {
+			if i > 0 && err == io.EOF {
+				err = io.ErrUnexpectedEOF
+			}
+			return x, err
+		}
+		if b < 0x80 {
+			if i == MaxVarintLen64-1 && b > 1 {
+				return x, errOverflow
+			}
+			return x | uint64(b)<<s, nil
+		}
+		x |= uint64(b&0x7f) << s
+		s += 7
+	}
+	return x, errOverflow
+}
+
+// ReadVarint reads an encoded signed integer from r and returns it as an int64.
+// The error is [io.EOF] only if no bytes were read.
+// If an [io.EOF] happens after reading some but not all the bytes,
+// ReadVarint returns [io.ErrUnexpectedEOF].
+func ReadVarint(r io.ByteReader) (int64, error) {
+	ux, err := ReadUvarint(r) // ok to continue in presence of error
+	x := int64(ux >> 1)
+	if ux&1 != 0 {
+		x = ^x
+	}
+	return x, err
+}

common/control/bind_finder.go

@@ -1,10 +1,12 @@
 package control
 
 import (
+	"net"
 	"net/netip"
 )
 
 type InterfaceFinder interface {
+	Interfaces() []Interface
 	InterfaceIndexByName(name string) (int, error)
 	InterfaceNameByIndex(index int) (string, error)
 	InterfaceByAddr(addr netip.Addr) (*Interface, error)
@@ -15,4 +17,5 @@ type Interface struct {
 	MTU          int
 	Name         string
 	Addresses    []netip.Prefix
+	HardwareAddr net.HardwareAddr
 }

common/control/bind_finder_default.go

@@ -9,6 +9,8 @@ import (
 	M "github.com/sagernet/sing/common/metadata"
 )
 
+var _ InterfaceFinder = (*DefaultInterfaceFinder)(nil)
+
 type DefaultInterfaceFinder struct {
 	interfaces []Interface
 }
@@ -33,6 +35,7 @@ func (f *DefaultInterfaceFinder) Update() error {
 			MTU:          netIf.MTU,
 			Name:         netIf.Name,
 			Addresses:    common.Map(ifAddrs, M.PrefixFromNet),
+			HardwareAddr: netIf.HardwareAddr,
 		})
 	}
 	f.interfaces = interfaces
@@ -43,6 +46,10 @@ func (f *DefaultInterfaceFinder) UpdateInterfaces(interfaces []Interface) {
 	f.interfaces = interfaces
 }
 
+func (f *DefaultInterfaceFinder) Interfaces() []Interface {
+	return f.interfaces
+}
+
 func (f *DefaultInterfaceFinder) InterfaceIndexByName(name string) (int, error) {
 	for _, netInterface := range f.interfaces {
 		if netInterface.Name == name {

common/control/interface.go

@@ -3,6 +3,7 @@ package control
 import (
 	"syscall"
 
+	"github.com/sagernet/sing/common"
 	E "github.com/sagernet/sing/common/exceptions"
 )
 
@@ -30,6 +31,14 @@ func Conn(conn syscall.Conn, block func(fd uintptr) error) error {
 	return Raw(rawConn, block)
 }
 
+func Conn0[T any](conn syscall.Conn, block func(fd uintptr) (T, error)) (T, error) {
+	rawConn, err := conn.SyscallConn()
+	if err != nil {
+		return common.DefaultValue[T](), err
+	}
+	return Raw0[T](rawConn, block)
+}
+
 func Raw(rawConn syscall.RawConn, block func(fd uintptr) error) error {
 	var innerErr error
 	err := rawConn.Control(func(fd uintptr) {
@@ -37,3 +46,14 @@ func Raw(rawConn syscall.RawConn, block func(fd uintptr) error) error {
 	})
 	return E.Errors(innerErr, err)
 }
+
+func Raw0[T any](rawConn syscall.RawConn, block func(fd uintptr) (T, error)) (T, error) {
+	var (
+		value    T
+		innerErr error
+	)
+	err := rawConn.Control(func(fd uintptr) {
+		value, innerErr = block(fd)
+	})
+	return value, E.Errors(innerErr, err)
+}

common/control/redirect_darwin.go

@@ -0,0 +1,58 @@
+package control
+
+import (
+	"encoding/binary"
+	"net"
+	"net/netip"
+	"syscall"
+	"unsafe"
+
+	M "github.com/sagernet/sing/common/metadata"
+
+	"golang.org/x/sys/unix"
+)
+
+const (
+	PF_OUT      = 0x2
+	DIOCNATLOOK = 0xc0544417
+)
+
+func GetOriginalDestination(conn net.Conn) (netip.AddrPort, error) {
+	pfFd, err := syscall.Open("/dev/pf", 0, syscall.O_RDONLY)
+	if err != nil {
+		return netip.AddrPort{}, err
+	}
+	defer syscall.Close(pfFd)
+	nl := struct {
+		saddr, daddr, rsaddr, rdaddr       [16]byte
+		sxport, dxport, rsxport, rdxport   [4]byte
+		af, proto, protoVariant, direction uint8
+	}{
+		af:        syscall.AF_INET,
+		proto:     syscall.IPPROTO_TCP,
+		direction: PF_OUT,
+	}
+	localAddr := M.SocksaddrFromNet(conn.LocalAddr()).Unwrap()
+	removeAddr := M.SocksaddrFromNet(conn.RemoteAddr()).Unwrap()
+	if localAddr.IsIPv4() {
+		copy(nl.saddr[:net.IPv4len], removeAddr.Addr.AsSlice())
+		copy(nl.daddr[:net.IPv4len], localAddr.Addr.AsSlice())
+		nl.af = syscall.AF_INET
+	} else {
+		copy(nl.saddr[:], removeAddr.Addr.AsSlice())
+		copy(nl.daddr[:], localAddr.Addr.AsSlice())
+		nl.af = syscall.AF_INET6
+	}
+	binary.BigEndian.PutUint16(nl.sxport[:], removeAddr.Port)
+	binary.BigEndian.PutUint16(nl.dxport[:], localAddr.Port)
+	if _, _, errno := unix.Syscall(syscall.SYS_IOCTL, uintptr(pfFd), DIOCNATLOOK, uintptr(unsafe.Pointer(&nl))); errno != 0 {
+		return netip.AddrPort{}, errno
+	}
+	var address netip.Addr
+	if nl.af == unix.AF_INET {
+		address = M.AddrFromIP(nl.rdaddr[:net.IPv4len])
+	} else {
+		address = netip.AddrFrom16(nl.rdaddr)
+	}
+	return netip.AddrPortFrom(address, binary.BigEndian.Uint16(nl.rdxport[:])), nil
+}

common/control/redirect_linux.go

@@ -0,0 +1,38 @@
+package control
+
+import (
+	"encoding/binary"
+	"net"
+	"net/netip"
+	"os"
+	"syscall"
+
+	"github.com/sagernet/sing/common"
+	M "github.com/sagernet/sing/common/metadata"
+
+	"golang.org/x/sys/unix"
+)
+
+func GetOriginalDestination(conn net.Conn) (netip.AddrPort, error) {
+	syscallConn, loaded := common.Cast[syscall.Conn](conn)
+	if !loaded {
+		return netip.AddrPort{}, os.ErrInvalid
+	}
+	return Conn0[netip.AddrPort](syscallConn, func(fd uintptr) (netip.AddrPort, error) {
+		if M.SocksaddrFromNet(conn.RemoteAddr()).Unwrap().IsIPv4() {
+			raw, err := unix.GetsockoptIPv6Mreq(int(fd), unix.IPPROTO_IP, unix.SO_ORIGINAL_DST)
+			if err != nil {
+				return netip.AddrPort{}, err
+			}
+			return netip.AddrPortFrom(M.AddrFromIP(raw.Multiaddr[4:8]), uint16(raw.Multiaddr[2])<<8+uint16(raw.Multiaddr[3])), nil
+		} else {
+			raw, err := unix.GetsockoptIPv6MTUInfo(int(fd), unix.IPPROTO_IPV6, unix.SO_ORIGINAL_DST)
+			if err != nil {
+				return netip.AddrPort{}, err
+			}
+			var port [2]byte
+			binary.BigEndian.PutUint16(port[:], raw.Addr.Port)
+			return netip.AddrPortFrom(M.AddrFromIP(raw.Addr.Addr[:]), binary.LittleEndian.Uint16(port[:])), nil
+		}
+	})
+}

common/control/redirect_other.go

@@ -0,0 +1,13 @@
+//go:build !linux && !darwin
+
+package control
+
+import (
+	"net"
+	"net/netip"
+	"os"
+)
+
+func GetOriginalDestination(conn net.Conn) (netip.AddrPort, error) {
+	return netip.AddrPort{}, os.ErrInvalid
+}

common/control/tproxy_linux.go

@@ -0,0 +1,56 @@
+package control
+
+import (
+	"encoding/binary"
+	"net/netip"
+	"syscall"
+
+	E "github.com/sagernet/sing/common/exceptions"
+	M "github.com/sagernet/sing/common/metadata"
+
+	"golang.org/x/sys/unix"
+)
+
+func TProxy(fd uintptr, family int) error {
+	err := syscall.SetsockoptInt(int(fd), syscall.SOL_SOCKET, syscall.SO_REUSEADDR, 1)
+	if err == nil {
+		err = syscall.SetsockoptInt(int(fd), syscall.SOL_IP, syscall.IP_TRANSPARENT, 1)
+	}
+	if err == nil && family == unix.AF_INET6 {
+		err = syscall.SetsockoptInt(int(fd), syscall.SOL_IPV6, unix.IPV6_TRANSPARENT, 1)
+	}
+	if err == nil {
+		err = syscall.SetsockoptInt(int(fd), syscall.SOL_IP, syscall.IP_RECVORIGDSTADDR, 1)
+	}
+	if err == nil && family == unix.AF_INET6 {
+		err = syscall.SetsockoptInt(int(fd), syscall.SOL_IPV6, unix.IPV6_RECVORIGDSTADDR, 1)
+	}
+	return err
+}
+
+func TProxyWriteBack() Func {
+	return func(network, address string, conn syscall.RawConn) error {
+		return Raw(conn, func(fd uintptr) error {
+			if M.ParseSocksaddr(address).Addr.Is6() {
+				return syscall.SetsockoptInt(int(fd), syscall.SOL_IPV6, unix.IPV6_TRANSPARENT, 1)
+			} else {
+				return syscall.SetsockoptInt(int(fd), syscall.SOL_IP, syscall.IP_TRANSPARENT, 1)
+			}
+		})
+	}
+}
+
+func GetOriginalDestinationFromOOB(oob []byte) (netip.AddrPort, error) {
+	controlMessages, err := unix.ParseSocketControlMessage(oob)
+	if err != nil {
+		return netip.AddrPort{}, err
+	}
+	for _, message := range controlMessages {
+		if message.Header.Level == unix.SOL_IP && message.Header.Type == unix.IP_RECVORIGDSTADDR {
+			return netip.AddrPortFrom(M.AddrFromIP(message.Data[4:8]), binary.BigEndian.Uint16(message.Data[2:4])), nil
+		} else if message.Header.Level == unix.SOL_IPV6 && message.Header.Type == unix.IPV6_RECVORIGDSTADDR {
+			return netip.AddrPortFrom(M.AddrFromIP(message.Data[8:24]), binary.BigEndian.Uint16(message.Data[2:4])), nil
+		}
+	}
+	return netip.AddrPort{}, E.New("not found")
+}

common/control/tproxy_other.go

@@ -0,0 +1,20 @@
+//go:build !linux
+
+package control
+
+import (
+	"net/netip"
+	"os"
+)
+
+func TProxy(fd uintptr, isIPv6 bool) error {
+	return os.ErrInvalid
+}
+
+func TProxyWriteBack() Func {
+	return nil
+}
+
+func GetOriginalDestinationFromOOB(oob []byte) (netip.AddrPort, error) {
+	return netip.AddrPort{}, os.ErrInvalid
+}

common/json/context.go

@@ -1,4 +1,4 @@
-//go:build go1.21 && !without_contextjson
+//go:build go1.20 && !without_contextjson
 
 package json
 

common/json/context_120.go

@@ -1,23 +0,0 @@
-//go:build !go1.21 && go1.20 && !without_contextjson
-
-package json
-
-import (
-	"github.com/sagernet/sing/common/json/internal/contextjson_120"
-)
-
-var (
-	Marshal    = json.Marshal
-	Unmarshal  = json.Unmarshal
-	NewEncoder = json.NewEncoder
-	NewDecoder = json.NewDecoder
-)
-
-type (
-	Encoder     = json.Encoder
-	Decoder     = json.Decoder
-	Token       = json.Token
-	Delim       = json.Delim
-	SyntaxError = json.SyntaxError
-	RawMessage  = json.RawMessage
-)

common/json/internal/contextjson/encode.go

@@ -442,7 +442,7 @@ func marshalerEncoder(e *encodeState, v reflect.Value, opts encOpts) {
 	b, err := m.MarshalJSON()
 	if err == nil {
 		e.Grow(len(b))
-		out := e.AvailableBuffer()
+		out := availableBuffer(&e.Buffer)
 		out, err = appendCompact(out, b, opts.escapeHTML)
 		e.Buffer.Write(out)
 	}
@@ -461,7 +461,7 @@ func addrMarshalerEncoder(e *encodeState, v reflect.Value, opts encOpts) {
 	b, err := m.MarshalJSON()
 	if err == nil {
 		e.Grow(len(b))
-		out := e.AvailableBuffer()
+		out := availableBuffer(&e.Buffer)
 		out, err = appendCompact(out, b, opts.escapeHTML)
 		e.Buffer.Write(out)
 	}
@@ -484,7 +484,7 @@ func textMarshalerEncoder(e *encodeState, v reflect.Value, opts encOpts) {
 	if err != nil {
 		e.error(&MarshalerError{v.Type(), err, "MarshalText"})
 	}
-	e.Write(appendString(e.AvailableBuffer(), b, opts.escapeHTML))
+	e.Write(appendString(availableBuffer(&e.Buffer), b, opts.escapeHTML))
 }
 
 func addrTextMarshalerEncoder(e *encodeState, v reflect.Value, opts encOpts) {
@@ -498,11 +498,11 @@ func addrTextMarshalerEncoder(e *encodeState, v reflect.Value, opts encOpts) {
 	if err != nil {
 		e.error(&MarshalerError{v.Type(), err, "MarshalText"})
 	}
-	e.Write(appendString(e.AvailableBuffer(), b, opts.escapeHTML))
+	e.Write(appendString(availableBuffer(&e.Buffer), b, opts.escapeHTML))
 }
 
 func boolEncoder(e *encodeState, v reflect.Value, opts encOpts) {
-	b := e.AvailableBuffer()
+	b := availableBuffer(&e.Buffer)
 	b = mayAppendQuote(b, opts.quoted)
 	b = strconv.AppendBool(b, v.Bool())
 	b = mayAppendQuote(b, opts.quoted)
@@ -510,7 +510,7 @@ func boolEncoder(e *encodeState, v reflect.Value, opts encOpts) {
 }
 
 func intEncoder(e *encodeState, v reflect.Value, opts encOpts) {
-	b := e.AvailableBuffer()
+	b := availableBuffer(&e.Buffer)
 	b = mayAppendQuote(b, opts.quoted)
 	b = strconv.AppendInt(b, v.Int(), 10)
 	b = mayAppendQuote(b, opts.quoted)
@@ -518,7 +518,7 @@ func intEncoder(e *encodeState, v reflect.Value, opts encOpts) {
 }
 
 func uintEncoder(e *encodeState, v reflect.Value, opts encOpts) {
-	b := e.AvailableBuffer()
+	b := availableBuffer(&e.Buffer)
 	b = mayAppendQuote(b, opts.quoted)
 	b = strconv.AppendUint(b, v.Uint(), 10)
 	b = mayAppendQuote(b, opts.quoted)
@@ -538,7 +538,7 @@ func (bits floatEncoder) encode(e *encodeState, v reflect.Value, opts encOpts) {
 	// See golang.org/issue/6384 and golang.org/issue/14135.
 	// Like fmt %g, but the exponent cutoffs are different
 	// and exponents themselves are not padded to two digits.
-	b := e.AvailableBuffer()
+	b := availableBuffer(&e.Buffer)
 	b = mayAppendQuote(b, opts.quoted)
 	abs := math.Abs(f)
 	fmt := byte('f')
@@ -577,7 +577,7 @@ func stringEncoder(e *encodeState, v reflect.Value, opts encOpts) {
 		if !isValidNumber(numStr) {
 			e.error(fmt.Errorf("json: invalid number literal %q", numStr))
 		}
-		b := e.AvailableBuffer()
+		b := availableBuffer(&e.Buffer)
 		b = mayAppendQuote(b, opts.quoted)
 		b = append(b, numStr...)
 		b = mayAppendQuote(b, opts.quoted)
@@ -586,9 +586,9 @@ func stringEncoder(e *encodeState, v reflect.Value, opts encOpts) {
 	}
 	if opts.quoted {
 		b := appendString(nil, v.String(), opts.escapeHTML)
-		e.Write(appendString(e.AvailableBuffer(), b, false)) // no need to escape again since it is already escaped
+		e.Write(appendString(availableBuffer(&e.Buffer), b, false)) // no need to escape again since it is already escaped
 	} else {
-		e.Write(appendString(e.AvailableBuffer(), v.String(), opts.escapeHTML))
+		e.Write(appendString(availableBuffer(&e.Buffer), v.String(), opts.escapeHTML))
 	}
 }
 
@@ -754,7 +754,7 @@ func (me mapEncoder) encode(e *encodeState, v reflect.Value, opts encOpts) {
 		if i > 0 {
 			e.WriteByte(',')
 		}
-		e.Write(appendString(e.AvailableBuffer(), kv.ks, opts.escapeHTML))
+		e.Write(appendString(availableBuffer(&e.Buffer), kv.ks, opts.escapeHTML))
 		e.WriteByte(':')
 		me.elemEnc(e, kv.v, opts)
 	}
@@ -786,7 +786,7 @@ func encodeByteSlice(e *encodeState, v reflect.Value, _ encOpts) {
 	e.Grow(len(`"`) + encodedLen + len(`"`))
 
 	// TODO(https://go.dev/issue/53693): Use base64.Encoding.AppendEncode.
-	b := e.AvailableBuffer()
+	b := availableBuffer(&e.Buffer)
 	b = append(b, '"')
 	base64.StdEncoding.Encode(b[len(b):][:encodedLen], s)
 	b = b[:len(b)+encodedLen]

common/json/internal/contextjson/indent.go

@@ -6,6 +6,11 @@ package json
 
 import "bytes"
 
+// TODO(https://go.dev/issue/53685): Use bytes.Buffer.AvailableBuffer instead.
+func availableBuffer(b *bytes.Buffer) []byte {
+	return b.Bytes()[b.Len():]
+}
+
 // HTMLEscape appends to dst the JSON-encoded src with <, >, &, U+2028 and U+2029
 // characters inside string literals changed to \u003c, \u003e, \u0026, \u2028, \u2029
 // so that the JSON will be safe to embed inside HTML <script> tags.
@@ -13,7 +18,7 @@ import "bytes"
 // escaping within <script> tags, so an alternative JSON encoding must be used.
 func HTMLEscape(dst *bytes.Buffer, src []byte) {
 	dst.Grow(len(src))
-	dst.Write(appendHTMLEscape(dst.AvailableBuffer(), src))
+	dst.Write(appendHTMLEscape(availableBuffer(dst), src))
 }
 
 func appendHTMLEscape(dst, src []byte) []byte {
@@ -40,7 +45,7 @@ func appendHTMLEscape(dst, src []byte) []byte {
 // insignificant space characters elided.
 func Compact(dst *bytes.Buffer, src []byte) error {
 	dst.Grow(len(src))
-	b := dst.AvailableBuffer()
+	b := availableBuffer(dst)
 	b, err := appendCompact(b, src, false)
 	dst.Write(b)
 	return err
@@ -109,7 +114,7 @@ const indentGrowthFactor = 2
 // if src ends in a trailing newline, so will dst.
 func Indent(dst *bytes.Buffer, src []byte, prefix, indent string) error {
 	dst.Grow(indentGrowthFactor * len(src))
-	b := dst.AvailableBuffer()
+	b := availableBuffer(dst)
 	b, err := appendIndent(b, src, prefix, indent)
 	dst.Write(b)
 	return err

common/json/internal/contextjson/scanner.go

@@ -300,7 +300,7 @@ func stateEndValue(s *scanner, c byte) int {
 	case parseObjectValue:
 		if c == ',' {
 			s.parseState[n-1] = parseObjectKey
-			s.step = stateBeginString
+			s.step = stateBeginStringOrEmpty
 			return scanObjectValue
 		}
 		if c == '}' {
@@ -310,7 +310,7 @@ func stateEndValue(s *scanner, c byte) int {
 		return s.error(c, "after object key:value pair")
 	case parseArrayValue:
 		if c == ',' {
-			s.step = stateBeginValue
+			s.step = stateBeginValueOrEmpty
 			return scanArrayValue
 		}
 		if c == ']' {

common/json/internal/contextjson/stream.go

@@ -153,6 +153,10 @@ func (dec *Decoder) refill() error {
 		dec.scanp = 0
 	}
 
+	return dec.refill0()
+}
+
+func (dec *Decoder) refill0() error {
 	// Grow buffer if not large enough.
 	const minRead = 512
 	if cap(dec.buf)-len(dec.buf) < minRead {
@@ -402,7 +406,7 @@ func (dec *Decoder) Token() (Token, error) {
 			return Delim('{'), nil
 
 		case '}':
-			if dec.tokenState != tokenObjectStart && dec.tokenState != tokenObjectComma {
+			if dec.tokenState != tokenObjectStart && dec.tokenState != tokenObjectComma && dec.tokenState != tokenObjectKey {
 				return dec.tokenError(c)
 			}
 			dec.scanp++
@@ -410,7 +414,6 @@ func (dec *Decoder) Token() (Token, error) {
 			dec.tokenStack = dec.tokenStack[:len(dec.tokenStack)-1]
 			dec.tokenValueEnd()
 			return Delim('}'), nil
-
 		case ':':
 			if dec.tokenState != tokenObjectColon {
 				return dec.tokenError(c)
@@ -483,7 +486,26 @@ func (dec *Decoder) tokenError(c byte) (Token, error) {
 // current array or object being parsed.
 func (dec *Decoder) More() bool {
 	c, err := dec.peek()
-	return err == nil && c != ']' && c != '}'
+	// return err == nil && c != ']' && c != '}'
+	if err != nil {
+		return false
+	}
+	if c == ']' || c == '}' {
+		return false
+	}
+	if c == ',' {
+		scanp := dec.scanp
+		dec.scanp++
+		c, err = dec.peekNoRefill()
+		dec.scanp = scanp
+		if err != nil {
+			return false
+		}
+		if c == ']' || c == '}' {
+			return false
+		}
+	}
+	return true
 }
 
 func (dec *Decoder) peek() (byte, error) {
@@ -505,6 +527,25 @@ func (dec *Decoder) peek() (byte, error) {
 	}
 }
 
+func (dec *Decoder) peekNoRefill() (byte, error) {
+	var err error
+	for {
+		for i := dec.scanp; i < len(dec.buf); i++ {
+			c := dec.buf[i]
+			if isSpace(c) {
+				continue
+			}
+			dec.scanp = i
+			return c, nil
+		}
+		// buffer has been scanned, now report any error
+		if err != nil {
+			return 0, err
+		}
+		err = dec.refill0()
+	}
+}
+
 // InputOffset returns the input stream byte offset of the current decoder position.
 // The offset gives the location of the end of the most recently returned token
 // and the beginning of the next token.

common/json/internal/contextjson_120/README.md

@@ -1,3 +0,0 @@
-# contextjson
-
-mod from go1.20.11

common/json/internal/contextjson_120/decode_context.go

@@ -1,49 +0,0 @@
-package json
-
-import "strconv"
-
-type decodeContext struct {
-	parent *decodeContext
-	index  int
-	key    string
-}
-
-func (d *decodeState) formatContext() string {
-	var description string
-	context := d.context
-	var appendDot bool
-	for context != nil {
-		if appendDot {
-			description = "." + description
-		}
-		if context.key != "" {
-			description = context.key + description
-			appendDot = true
-		} else {
-			description = "[" + strconv.Itoa(context.index) + "]" + description
-			appendDot = false
-		}
-		context = context.parent
-	}
-	return description
-}
-
-type contextError struct {
-	parent  error
-	context string
-	index   bool
-}
-
-func (c *contextError) Unwrap() error {
-	return c.parent
-}
-
-func (c *contextError) Error() string {
-	//goland:noinspection GoTypeAssertionOnErrors
-	switch c.parent.(type) {
-	case *contextError:
-		return c.context + "." + c.parent.Error()
-	default:
-		return c.context + ": " + c.parent.Error()
-	}
-}

common/json/internal/contextjson_120/fold.go

@@ -1,141 +0,0 @@
-// Copyright 2013 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package json
-
-import (
-	"bytes"
-	"unicode/utf8"
-)
-
-const (
-	caseMask     = ^byte(0x20) // Mask to ignore case in ASCII.
-	kelvin       = '\u212a'
-	smallLongEss = '\u017f'
-)
-
-// foldFunc returns one of four different case folding equivalence
-// functions, from most general (and slow) to fastest:
-//
-// 1) bytes.EqualFold, if the key s contains any non-ASCII UTF-8
-// 2) equalFoldRight, if s contains special folding ASCII ('k', 'K', 's', 'S')
-// 3) asciiEqualFold, no special, but includes non-letters (including _)
-// 4) simpleLetterEqualFold, no specials, no non-letters.
-//
-// The letters S and K are special because they map to 3 runes, not just 2:
-//   - S maps to s and to U+017F 'ſ' Latin small letter long s
-//   - k maps to K and to U+212A 'K' Kelvin sign
-//
-// See https://play.golang.org/p/tTxjOc0OGo
-//
-// The returned function is specialized for matching against s and
-// should only be given s. It's not curried for performance reasons.
-func foldFunc(s []byte) func(s, t []byte) bool {
-	nonLetter := false
-	special := false // special letter
-	for _, b := range s {
-		if b >= utf8.RuneSelf {
-			return bytes.EqualFold
-		}
-		upper := b & caseMask
-		if upper < 'A' || upper > 'Z' {
-			nonLetter = true
-		} else if upper == 'K' || upper == 'S' {
-			// See above for why these letters are special.
-			special = true
-		}
-	}
-	if special {
-		return equalFoldRight
-	}
-	if nonLetter {
-		return asciiEqualFold
-	}
-	return simpleLetterEqualFold
-}
-
-// equalFoldRight is a specialization of bytes.EqualFold when s is
-// known to be all ASCII (including punctuation), but contains an 's',
-// 'S', 'k', or 'K', requiring a Unicode fold on the bytes in t.
-// See comments on foldFunc.
-func equalFoldRight(s, t []byte) bool {
-	for _, sb := range s {
-		if len(t) == 0 {
-			return false
-		}
-		tb := t[0]
-		if tb < utf8.RuneSelf {
-			if sb != tb {
-				sbUpper := sb & caseMask
-				if 'A' <= sbUpper && sbUpper <= 'Z' {
-					if sbUpper != tb&caseMask {
-						return false
-					}
-				} else {
-					return false
-				}
-			}
-			t = t[1:]
-			continue
-		}
-		// sb is ASCII and t is not. t must be either kelvin
-		// sign or long s; sb must be s, S, k, or K.
-		tr, size := utf8.DecodeRune(t)
-		switch sb {
-		case 's', 'S':
-			if tr != smallLongEss {
-				return false
-			}
-		case 'k', 'K':
-			if tr != kelvin {
-				return false
-			}
-		default:
-			return false
-		}
-		t = t[size:]
-
-	}
-	return len(t) == 0
-}
-
-// asciiEqualFold is a specialization of bytes.EqualFold for use when
-// s is all ASCII (but may contain non-letters) and contains no
-// special-folding letters.
-// See comments on foldFunc.
-func asciiEqualFold(s, t []byte) bool {
-	if len(s) != len(t) {
-		return false
-	}
-	for i, sb := range s {
-		tb := t[i]
-		if sb == tb {
-			continue
-		}
-		if ('a' <= sb && sb <= 'z') || ('A' <= sb && sb <= 'Z') {
-			if sb&caseMask != tb&caseMask {
-				return false
-			}
-		} else {
-			return false
-		}
-	}
-	return true
-}
-
-// simpleLetterEqualFold is a specialization of bytes.EqualFold for
-// use when s is all ASCII letters (no underscores, etc) and also
-// doesn't contain 'k', 'K', 's', or 'S'.
-// See comments on foldFunc.
-func simpleLetterEqualFold(s, t []byte) bool {
-	if len(s) != len(t) {
-		return false
-	}
-	for i, b := range s {
-		if b&caseMask != t[i]&caseMask {
-			return false
-		}
-	}
-	return true
-}

common/json/internal/contextjson_120/fuzz.go

@@ -1,42 +0,0 @@
-// Copyright 2019 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build gofuzz
-
-package json
-
-import (
-	"fmt"
-)
-
-func Fuzz(data []byte) (score int) {
-	for _, ctor := range []func() any{
-		func() any { return new(any) },
-		func() any { return new(map[string]any) },
-		func() any { return new([]any) },
-	} {
-		v := ctor()
-		err := Unmarshal(data, v)
-		if err != nil {
-			continue
-		}
-		score = 1
-
-		m, err := Marshal(v)
-		if err != nil {
-			fmt.Printf("v=%#v\n", v)
-			panic(err)
-		}
-
-		u := ctor()
-		err = Unmarshal(m, u)
-		if err != nil {
-			fmt.Printf("v=%#v\n", v)
-			fmt.Printf("m=%s\n", m)
-			panic(err)
-		}
-	}
-
-	return
-}

common/json/internal/contextjson_120/indent.go

@@ -1,143 +0,0 @@
-// Copyright 2010 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package json
-
-import (
-	"bytes"
-)
-
-// Compact appends to dst the JSON-encoded src with
-// insignificant space characters elided.
-func Compact(dst *bytes.Buffer, src []byte) error {
-	return compact(dst, src, false)
-}
-
-func compact(dst *bytes.Buffer, src []byte, escape bool) error {
-	origLen := dst.Len()
-	scan := newScanner()
-	defer freeScanner(scan)
-	start := 0
-	for i, c := range src {
-		if escape && (c == '<' || c == '>' || c == '&') {
-			if start < i {
-				dst.Write(src[start:i])
-			}
-			dst.WriteString(`\u00`)
-			dst.WriteByte(hex[c>>4])
-			dst.WriteByte(hex[c&0xF])
-			start = i + 1
-		}
-		// Convert U+2028 and U+2029 (E2 80 A8 and E2 80 A9).
-		if escape && c == 0xE2 && i+2 < len(src) && src[i+1] == 0x80 && src[i+2]&^1 == 0xA8 {
-			if start < i {
-				dst.Write(src[start:i])
-			}
-			dst.WriteString(`\u202`)
-			dst.WriteByte(hex[src[i+2]&0xF])
-			start = i + 3
-		}
-		v := scan.step(scan, c)
-		if v >= scanSkipSpace {
-			if v == scanError {
-				break
-			}
-			if start < i {
-				dst.Write(src[start:i])
-			}
-			start = i + 1
-		}
-	}
-	if scan.eof() == scanError {
-		dst.Truncate(origLen)
-		return scan.err
-	}
-	if start < len(src) {
-		dst.Write(src[start:])
-	}
-	return nil
-}
-
-func newline(dst *bytes.Buffer, prefix, indent string, depth int) {
-	dst.WriteByte('\n')
-	dst.WriteString(prefix)
-	for i := 0; i < depth; i++ {
-		dst.WriteString(indent)
-	}
-}
-
-// Indent appends to dst an indented form of the JSON-encoded src.
-// Each element in a JSON object or array begins on a new,
-// indented line beginning with prefix followed by one or more
-// copies of indent according to the indentation nesting.
-// The data appended to dst does not begin with the prefix nor
-// any indentation, to make it easier to embed inside other formatted JSON data.
-// Although leading space characters (space, tab, carriage return, newline)
-// at the beginning of src are dropped, trailing space characters
-// at the end of src are preserved and copied to dst.
-// For example, if src has no trailing spaces, neither will dst;
-// if src ends in a trailing newline, so will dst.
-func Indent(dst *bytes.Buffer, src []byte, prefix, indent string) error {
-	origLen := dst.Len()
-	scan := newScanner()
-	defer freeScanner(scan)
-	needIndent := false
-	depth := 0
-	for _, c := range src {
-		scan.bytes++
-		v := scan.step(scan, c)
-		if v == scanSkipSpace {
-			continue
-		}
-		if v == scanError {
-			break
-		}
-		if needIndent && v != scanEndObject && v != scanEndArray {
-			needIndent = false
-			depth++
-			newline(dst, prefix, indent, depth)
-		}
-
-		// Emit semantically uninteresting bytes
-		// (in particular, punctuation in strings) unmodified.
-		if v == scanContinue {
-			dst.WriteByte(c)
-			continue
-		}
-
-		// Add spacing around real punctuation.
-		switch c {
-		case '{', '[':
-			// delay indent so that empty object and array are formatted as {} and [].
-			needIndent = true
-			dst.WriteByte(c)
-
-		case ',':
-			dst.WriteByte(c)
-			newline(dst, prefix, indent, depth)
-
-		case ':':
-			dst.WriteByte(c)
-			dst.WriteByte(' ')
-
-		case '}', ']':
-			if needIndent {
-				// suppress indent in empty object/array
-				needIndent = false
-			} else {
-				depth--
-				newline(dst, prefix, indent, depth)
-			}
-			dst.WriteByte(c)
-
-		default:
-			dst.WriteByte(c)
-		}
-	}
-	if scan.eof() == scanError {
-		dst.Truncate(origLen)
-		return scan.err
-	}
-	return nil
-}

common/json/internal/contextjson_120/scanner.go

@@ -1,610 +0,0 @@
-// Copyright 2010 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package json
-
-// JSON value parser state machine.
-// Just about at the limit of what is reasonable to write by hand.
-// Some parts are a bit tedious, but overall it nicely factors out the
-// otherwise common code from the multiple scanning functions
-// in this package (Compact, Indent, checkValid, etc).
-//
-// This file starts with two simple examples using the scanner
-// before diving into the scanner itself.
-
-import (
-	"strconv"
-	"sync"
-)
-
-// Valid reports whether data is a valid JSON encoding.
-func Valid(data []byte) bool {
-	scan := newScanner()
-	defer freeScanner(scan)
-	return checkValid(data, scan) == nil
-}
-
-// checkValid verifies that data is valid JSON-encoded data.
-// scan is passed in for use by checkValid to avoid an allocation.
-// checkValid returns nil or a SyntaxError.
-func checkValid(data []byte, scan *scanner) error {
-	scan.reset()
-	for _, c := range data {
-		scan.bytes++
-		if scan.step(scan, c) == scanError {
-			return scan.err
-		}
-	}
-	if scan.eof() == scanError {
-		return scan.err
-	}
-	return nil
-}
-
-// A SyntaxError is a description of a JSON syntax error.
-// Unmarshal will return a SyntaxError if the JSON can't be parsed.
-type SyntaxError struct {
-	msg    string // description of error
-	Offset int64  // error occurred after reading Offset bytes
-}
-
-func (e *SyntaxError) Error() string { return e.msg }
-
-// A scanner is a JSON scanning state machine.
-// Callers call scan.reset and then pass bytes in one at a time
-// by calling scan.step(&scan, c) for each byte.
-// The return value, referred to as an opcode, tells the
-// caller about significant parsing events like beginning
-// and ending literals, objects, and arrays, so that the
-// caller can follow along if it wishes.
-// The return value scanEnd indicates that a single top-level
-// JSON value has been completed, *before* the byte that
-// just got passed in.  (The indication must be delayed in order
-// to recognize the end of numbers: is 123 a whole value or
-// the beginning of 12345e+6?).
-type scanner struct {
-	// The step is a func to be called to execute the next transition.
-	// Also tried using an integer constant and a single func
-	// with a switch, but using the func directly was 10% faster
-	// on a 64-bit Mac Mini, and it's nicer to read.
-	step func(*scanner, byte) int
-
-	// Reached end of top-level value.
-	endTop bool
-
-	// Stack of what we're in the middle of - array values, object keys, object values.
-	parseState []int
-
-	// Error that happened, if any.
-	err error
-
-	// total bytes consumed, updated by decoder.Decode (and deliberately
-	// not set to zero by scan.reset)
-	bytes int64
-}
-
-var scannerPool = sync.Pool{
-	New: func() any {
-		return &scanner{}
-	},
-}
-
-func newScanner() *scanner {
-	scan := scannerPool.Get().(*scanner)
-	// scan.reset by design doesn't set bytes to zero
-	scan.bytes = 0
-	scan.reset()
-	return scan
-}
-
-func freeScanner(scan *scanner) {
-	// Avoid hanging on to too much memory in extreme cases.
-	if len(scan.parseState) > 1024 {
-		scan.parseState = nil
-	}
-	scannerPool.Put(scan)
-}
-
-// These values are returned by the state transition functions
-// assigned to scanner.state and the method scanner.eof.
-// They give details about the current state of the scan that
-// callers might be interested to know about.
-// It is okay to ignore the return value of any particular
-// call to scanner.state: if one call returns scanError,
-// every subsequent call will return scanError too.
-const (
-	// Continue.
-	scanContinue     = iota // uninteresting byte
-	scanBeginLiteral        // end implied by next result != scanContinue
-	scanBeginObject         // begin object
-	scanObjectKey           // just finished object key (string)
-	scanObjectValue         // just finished non-last object value
-	scanEndObject           // end object (implies scanObjectValue if possible)
-	scanBeginArray          // begin array
-	scanArrayValue          // just finished array value
-	scanEndArray            // end array (implies scanArrayValue if possible)
-	scanSkipSpace           // space byte; can skip; known to be last "continue" result
-
-	// Stop.
-	scanEnd   // top-level value ended *before* this byte; known to be first "stop" result
-	scanError // hit an error, scanner.err.
-)
-
-// These values are stored in the parseState stack.
-// They give the current state of a composite value
-// being scanned. If the parser is inside a nested value
-// the parseState describes the nested state, outermost at entry 0.
-const (
-	parseObjectKey   = iota // parsing object key (before colon)
-	parseObjectValue        // parsing object value (after colon)
-	parseArrayValue         // parsing array value
-)
-
-// This limits the max nesting depth to prevent stack overflow.
-// This is permitted by https://tools.ietf.org/html/rfc7159#section-9
-const maxNestingDepth = 10000
-
-// reset prepares the scanner for use.
-// It must be called before calling s.step.
-func (s *scanner) reset() {
-	s.step = stateBeginValue
-	s.parseState = s.parseState[0:0]
-	s.err = nil
-	s.endTop = false
-}
-
-// eof tells the scanner that the end of input has been reached.
-// It returns a scan status just as s.step does.
-func (s *scanner) eof() int {
-	if s.err != nil {
-		return scanError
-	}
-	if s.endTop {
-		return scanEnd
-	}
-	s.step(s, ' ')
-	if s.endTop {
-		return scanEnd
-	}
-	if s.err == nil {
-		s.err = &SyntaxError{"unexpected end of JSON input", s.bytes}
-	}
-	return scanError
-}
-
-// pushParseState pushes a new parse state p onto the parse stack.
-// an error state is returned if maxNestingDepth was exceeded, otherwise successState is returned.
-func (s *scanner) pushParseState(c byte, newParseState int, successState int) int {
-	s.parseState = append(s.parseState, newParseState)
-	if len(s.parseState) <= maxNestingDepth {
-		return successState
-	}
-	return s.error(c, "exceeded max depth")
-}
-
-// popParseState pops a parse state (already obtained) off the stack
-// and updates s.step accordingly.
-func (s *scanner) popParseState() {
-	n := len(s.parseState) - 1
-	s.parseState = s.parseState[0:n]
-	if n == 0 {
-		s.step = stateEndTop
-		s.endTop = true
-	} else {
-		s.step = stateEndValue
-	}
-}
-
-func isSpace(c byte) bool {
-	return c <= ' ' && (c == ' ' || c == '\t' || c == '\r' || c == '\n')
-}
-
-// stateBeginValueOrEmpty is the state after reading `[`.
-func stateBeginValueOrEmpty(s *scanner, c byte) int {
-	if isSpace(c) {
-		return scanSkipSpace
-	}
-	if c == ']' {
-		return stateEndValue(s, c)
-	}
-	return stateBeginValue(s, c)
-}
-
-// stateBeginValue is the state at the beginning of the input.
-func stateBeginValue(s *scanner, c byte) int {
-	if isSpace(c) {
-		return scanSkipSpace
-	}
-	switch c {
-	case '{':
-		s.step = stateBeginStringOrEmpty
-		return s.pushParseState(c, parseObjectKey, scanBeginObject)
-	case '[':
-		s.step = stateBeginValueOrEmpty
-		return s.pushParseState(c, parseArrayValue, scanBeginArray)
-	case '"':
-		s.step = stateInString
-		return scanBeginLiteral
-	case '-':
-		s.step = stateNeg
-		return scanBeginLiteral
-	case '0': // beginning of 0.123
-		s.step = state0
-		return scanBeginLiteral
-	case 't': // beginning of true
-		s.step = stateT
-		return scanBeginLiteral
-	case 'f': // beginning of false
-		s.step = stateF
-		return scanBeginLiteral
-	case 'n': // beginning of null
-		s.step = stateN
-		return scanBeginLiteral
-	}
-	if '1' <= c && c <= '9' { // beginning of 1234.5
-		s.step = state1
-		return scanBeginLiteral
-	}
-	return s.error(c, "looking for beginning of value")
-}
-
-// stateBeginStringOrEmpty is the state after reading `{`.
-func stateBeginStringOrEmpty(s *scanner, c byte) int {
-	if isSpace(c) {
-		return scanSkipSpace
-	}
-	if c == '}' {
-		n := len(s.parseState)
-		s.parseState[n-1] = parseObjectValue
-		return stateEndValue(s, c)
-	}
-	return stateBeginString(s, c)
-}
-
-// stateBeginString is the state after reading `{"key": value,`.
-func stateBeginString(s *scanner, c byte) int {
-	if isSpace(c) {
-		return scanSkipSpace
-	}
-	if c == '"' {
-		s.step = stateInString
-		return scanBeginLiteral
-	}
-	return s.error(c, "looking for beginning of object key string")
-}
-
-// stateEndValue is the state after completing a value,
-// such as after reading `{}` or `true` or `["x"`.
-func stateEndValue(s *scanner, c byte) int {
-	n := len(s.parseState)
-	if n == 0 {
-		// Completed top-level before the current byte.
-		s.step = stateEndTop
-		s.endTop = true
-		return stateEndTop(s, c)
-	}
-	if isSpace(c) {
-		s.step = stateEndValue
-		return scanSkipSpace
-	}
-	ps := s.parseState[n-1]
-	switch ps {
-	case parseObjectKey:
-		if c == ':' {
-			s.parseState[n-1] = parseObjectValue
-			s.step = stateBeginValue
-			return scanObjectKey
-		}
-		return s.error(c, "after object key")
-	case parseObjectValue:
-		if c == ',' {
-			s.parseState[n-1] = parseObjectKey
-			s.step = stateBeginString
-			return scanObjectValue
-		}
-		if c == '}' {
-			s.popParseState()
-			return scanEndObject
-		}
-		return s.error(c, "after object key:value pair")
-	case parseArrayValue:
-		if c == ',' {
-			s.step = stateBeginValue
-			return scanArrayValue
-		}
-		if c == ']' {
-			s.popParseState()
-			return scanEndArray
-		}
-		return s.error(c, "after array element")
-	}
-	return s.error(c, "")
-}
-
-// stateEndTop is the state after finishing the top-level value,
-// such as after reading `{}` or `[1,2,3]`.
-// Only space characters should be seen now.
-func stateEndTop(s *scanner, c byte) int {
-	if !isSpace(c) {
-		// Complain about non-space byte on next call.
-		s.error(c, "after top-level value")
-	}
-	return scanEnd
-}
-
-// stateInString is the state after reading `"`.
-func stateInString(s *scanner, c byte) int {
-	if c == '"' {
-		s.step = stateEndValue
-		return scanContinue
-	}
-	if c == '\\' {
-		s.step = stateInStringEsc
-		return scanContinue
-	}
-	if c < 0x20 {
-		return s.error(c, "in string literal")
-	}
-	return scanContinue
-}
-
-// stateInStringEsc is the state after reading `"\` during a quoted string.
-func stateInStringEsc(s *scanner, c byte) int {
-	switch c {
-	case 'b', 'f', 'n', 'r', 't', '\\', '/', '"':
-		s.step = stateInString
-		return scanContinue
-	case 'u':
-		s.step = stateInStringEscU
-		return scanContinue
-	}
-	return s.error(c, "in string escape code")
-}
-
-// stateInStringEscU is the state after reading `"\u` during a quoted string.
-func stateInStringEscU(s *scanner, c byte) int {
-	if '0' <= c && c <= '9' || 'a' <= c && c <= 'f' || 'A' <= c && c <= 'F' {
-		s.step = stateInStringEscU1
-		return scanContinue
-	}
-	// numbers
-	return s.error(c, "in \\u hexadecimal character escape")
-}
-
-// stateInStringEscU1 is the state after reading `"\u1` during a quoted string.
-func stateInStringEscU1(s *scanner, c byte) int {
-	if '0' <= c && c <= '9' || 'a' <= c && c <= 'f' || 'A' <= c && c <= 'F' {
-		s.step = stateInStringEscU12
-		return scanContinue
-	}
-	// numbers
-	return s.error(c, "in \\u hexadecimal character escape")
-}
-
-// stateInStringEscU12 is the state after reading `"\u12` during a quoted string.
-func stateInStringEscU12(s *scanner, c byte) int {
-	if '0' <= c && c <= '9' || 'a' <= c && c <= 'f' || 'A' <= c && c <= 'F' {
-		s.step = stateInStringEscU123
-		return scanContinue
-	}
-	// numbers
-	return s.error(c, "in \\u hexadecimal character escape")
-}
-
-// stateInStringEscU123 is the state after reading `"\u123` during a quoted string.
-func stateInStringEscU123(s *scanner, c byte) int {
-	if '0' <= c && c <= '9' || 'a' <= c && c <= 'f' || 'A' <= c && c <= 'F' {
-		s.step = stateInString
-		return scanContinue
-	}
-	// numbers
-	return s.error(c, "in \\u hexadecimal character escape")
-}
-
-// stateNeg is the state after reading `-` during a number.
-func stateNeg(s *scanner, c byte) int {
-	if c == '0' {
-		s.step = state0
-		return scanContinue
-	}
-	if '1' <= c && c <= '9' {
-		s.step = state1
-		return scanContinue
-	}
-	return s.error(c, "in numeric literal")
-}
-
-// state1 is the state after reading a non-zero integer during a number,
-// such as after reading `1` or `100` but not `0`.
-func state1(s *scanner, c byte) int {
-	if '0' <= c && c <= '9' {
-		s.step = state1
-		return scanContinue
-	}
-	return state0(s, c)
-}
-
-// state0 is the state after reading `0` during a number.
-func state0(s *scanner, c byte) int {
-	if c == '.' {
-		s.step = stateDot
-		return scanContinue
-	}
-	if c == 'e' || c == 'E' {
-		s.step = stateE
-		return scanContinue
-	}
-	return stateEndValue(s, c)
-}
-
-// stateDot is the state after reading the integer and decimal point in a number,
-// such as after reading `1.`.
-func stateDot(s *scanner, c byte) int {
-	if '0' <= c && c <= '9' {
-		s.step = stateDot0
-		return scanContinue
-	}
-	return s.error(c, "after decimal point in numeric literal")
-}
-
-// stateDot0 is the state after reading the integer, decimal point, and subsequent
-// digits of a number, such as after reading `3.14`.
-func stateDot0(s *scanner, c byte) int {
-	if '0' <= c && c <= '9' {
-		return scanContinue
-	}
-	if c == 'e' || c == 'E' {
-		s.step = stateE
-		return scanContinue
-	}
-	return stateEndValue(s, c)
-}
-
-// stateE is the state after reading the mantissa and e in a number,
-// such as after reading `314e` or `0.314e`.
-func stateE(s *scanner, c byte) int {
-	if c == '+' || c == '-' {
-		s.step = stateESign
-		return scanContinue
-	}
-	return stateESign(s, c)
-}
-
-// stateESign is the state after reading the mantissa, e, and sign in a number,
-// such as after reading `314e-` or `0.314e+`.
-func stateESign(s *scanner, c byte) int {
-	if '0' <= c && c <= '9' {
-		s.step = stateE0
-		return scanContinue
-	}
-	return s.error(c, "in exponent of numeric literal")
-}
-
-// stateE0 is the state after reading the mantissa, e, optional sign,
-// and at least one digit of the exponent in a number,
-// such as after reading `314e-2` or `0.314e+1` or `3.14e0`.
-func stateE0(s *scanner, c byte) int {
-	if '0' <= c && c <= '9' {
-		return scanContinue
-	}
-	return stateEndValue(s, c)
-}
-
-// stateT is the state after reading `t`.
-func stateT(s *scanner, c byte) int {
-	if c == 'r' {
-		s.step = stateTr
-		return scanContinue
-	}
-	return s.error(c, "in literal true (expecting 'r')")
-}
-
-// stateTr is the state after reading `tr`.
-func stateTr(s *scanner, c byte) int {
-	if c == 'u' {
-		s.step = stateTru
-		return scanContinue
-	}
-	return s.error(c, "in literal true (expecting 'u')")
-}
-
-// stateTru is the state after reading `tru`.
-func stateTru(s *scanner, c byte) int {
-	if c == 'e' {
-		s.step = stateEndValue
-		return scanContinue
-	}
-	return s.error(c, "in literal true (expecting 'e')")
-}
-
-// stateF is the state after reading `f`.
-func stateF(s *scanner, c byte) int {
-	if c == 'a' {
-		s.step = stateFa
-		return scanContinue
-	}
-	return s.error(c, "in literal false (expecting 'a')")
-}
-
-// stateFa is the state after reading `fa`.
-func stateFa(s *scanner, c byte) int {
-	if c == 'l' {
-		s.step = stateFal
-		return scanContinue
-	}
-	return s.error(c, "in literal false (expecting 'l')")
-}
-
-// stateFal is the state after reading `fal`.
-func stateFal(s *scanner, c byte) int {
-	if c == 's' {
-		s.step = stateFals
-		return scanContinue
-	}
-	return s.error(c, "in literal false (expecting 's')")
-}
-
-// stateFals is the state after reading `fals`.
-func stateFals(s *scanner, c byte) int {
-	if c == 'e' {
-		s.step = stateEndValue
-		return scanContinue
-	}
-	return s.error(c, "in literal false (expecting 'e')")
-}
-
-// stateN is the state after reading `n`.
-func stateN(s *scanner, c byte) int {
-	if c == 'u' {
-		s.step = stateNu
-		return scanContinue
-	}
-	return s.error(c, "in literal null (expecting 'u')")
-}
-
-// stateNu is the state after reading `nu`.
-func stateNu(s *scanner, c byte) int {
-	if c == 'l' {
-		s.step = stateNul
-		return scanContinue
-	}
-	return s.error(c, "in literal null (expecting 'l')")
-}
-
-// stateNul is the state after reading `nul`.
-func stateNul(s *scanner, c byte) int {
-	if c == 'l' {
-		s.step = stateEndValue
-		return scanContinue
-	}
-	return s.error(c, "in literal null (expecting 'l')")
-}
-
-// stateError is the state after reaching a syntax error,
-// such as after reading `[1}` or `5.1.2`.
-func stateError(s *scanner, c byte) int {
-	return scanError
-}
-
-// error records an error and switches to the error state.
-func (s *scanner) error(c byte, context string) int {
-	s.step = stateError
-	s.err = &SyntaxError{"invalid character " + quoteChar(c) + " " + context, s.bytes}
-	return scanError
-}
-
-// quoteChar formats c as a quoted character literal.
-func quoteChar(c byte) string {
-	// special cases - different from quoted strings
-	if c == '\'' {
-		return `'\''`
-	}
-	if c == '"' {
-		return `'"'`
-	}
-
-	// use quoted string with different quotation marks
-	s := strconv.Quote(string(c))
-	return "'" + s[1:len(s)-1] + "'"
-}

common/json/internal/contextjson_120/stream.go

@@ -1,517 +0,0 @@
-// Copyright 2010 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package json
-
-import (
-	"bytes"
-	"errors"
-	"io"
-)
-
-// A Decoder reads and decodes JSON values from an input stream.
-type Decoder struct {
-	r       io.Reader
-	buf     []byte
-	d       decodeState
-	scanp   int   // start of unread data in buf
-	scanned int64 // amount of data already scanned
-	scan    scanner
-	err     error
-
-	tokenState int
-	tokenStack []int
-}
-
-// NewDecoder returns a new decoder that reads from r.
-//
-// The decoder introduces its own buffering and may
-// read data from r beyond the JSON values requested.
-func NewDecoder(r io.Reader) *Decoder {
-	return &Decoder{r: r}
-}
-
-// UseNumber causes the Decoder to unmarshal a number into an interface{} as a
-// Number instead of as a float64.
-func (dec *Decoder) UseNumber() { dec.d.useNumber = true }
-
-// DisallowUnknownFields causes the Decoder to return an error when the destination
-// is a struct and the input contains object keys which do not match any
-// non-ignored, exported fields in the destination.
-func (dec *Decoder) DisallowUnknownFields() { dec.d.disallowUnknownFields = true }
-
-// Decode reads the next JSON-encoded value from its
-// input and stores it in the value pointed to by v.
-//
-// See the documentation for Unmarshal for details about
-// the conversion of JSON into a Go value.
-func (dec *Decoder) Decode(v any) error {
-	if dec.err != nil {
-		return dec.err
-	}
-
-	if err := dec.tokenPrepareForDecode(); err != nil {
-		return err
-	}
-
-	if !dec.tokenValueAllowed() {
-		return &SyntaxError{msg: "not at beginning of value", Offset: dec.InputOffset()}
-	}
-
-	// Read whole value into buffer.
-	n, err := dec.readValue()
-	if err != nil {
-		return err
-	}
-	dec.d.init(dec.buf[dec.scanp : dec.scanp+n])
-	dec.scanp += n
-
-	// Don't save err from unmarshal into dec.err:
-	// the connection is still usable since we read a complete JSON
-	// object from it before the error happened.
-	err = dec.d.unmarshal(v)
-
-	// fixup token streaming state
-	dec.tokenValueEnd()
-
-	return err
-}
-
-// Buffered returns a reader of the data remaining in the Decoder's
-// buffer. The reader is valid until the next call to Decode.
-func (dec *Decoder) Buffered() io.Reader {
-	return bytes.NewReader(dec.buf[dec.scanp:])
-}
-
-// readValue reads a JSON value into dec.buf.
-// It returns the length of the encoding.
-func (dec *Decoder) readValue() (int, error) {
-	dec.scan.reset()
-
-	scanp := dec.scanp
-	var err error
-Input:
-	// help the compiler see that scanp is never negative, so it can remove
-	// some bounds checks below.
-	for scanp >= 0 {
-
-		// Look in the buffer for a new value.
-		for ; scanp < len(dec.buf); scanp++ {
-			c := dec.buf[scanp]
-			dec.scan.bytes++
-			switch dec.scan.step(&dec.scan, c) {
-			case scanEnd:
-				// scanEnd is delayed one byte so we decrement
-				// the scanner bytes count by 1 to ensure that
-				// this value is correct in the next call of Decode.
-				dec.scan.bytes--
-				break Input
-			case scanEndObject, scanEndArray:
-				// scanEnd is delayed one byte.
-				// We might block trying to get that byte from src,
-				// so instead invent a space byte.
-				if stateEndValue(&dec.scan, ' ') == scanEnd {
-					scanp++
-					break Input
-				}
-			case scanError:
-				dec.err = dec.scan.err
-				return 0, dec.scan.err
-			}
-		}
-
-		// Did the last read have an error?
-		// Delayed until now to allow buffer scan.
-		if err != nil {
-			if err == io.EOF {
-				if dec.scan.step(&dec.scan, ' ') == scanEnd {
-					break Input
-				}
-				if nonSpace(dec.buf) {
-					err = io.ErrUnexpectedEOF
-				}
-			}
-			dec.err = err
-			return 0, err
-		}
-
-		n := scanp - dec.scanp
-		err = dec.refill()
-		scanp = dec.scanp + n
-	}
-	return scanp - dec.scanp, nil
-}
-
-func (dec *Decoder) refill() error {
-	// Make room to read more into the buffer.
-	// First slide down data already consumed.
-	if dec.scanp > 0 {
-		dec.scanned += int64(dec.scanp)
-		n := copy(dec.buf, dec.buf[dec.scanp:])
-		dec.buf = dec.buf[:n]
-		dec.scanp = 0
-	}
-
-	// Grow buffer if not large enough.
-	const minRead = 512
-	if cap(dec.buf)-len(dec.buf) < minRead {
-		newBuf := make([]byte, len(dec.buf), 2*cap(dec.buf)+minRead)
-		copy(newBuf, dec.buf)
-		dec.buf = newBuf
-	}
-
-	// Read. Delay error for next iteration (after scan).
-	n, err := dec.r.Read(dec.buf[len(dec.buf):cap(dec.buf)])
-	dec.buf = dec.buf[0 : len(dec.buf)+n]
-
-	return err
-}
-
-func nonSpace(b []byte) bool {
-	for _, c := range b {
-		if !isSpace(c) {
-			return true
-		}
-	}
-	return false
-}
-
-// An Encoder writes JSON values to an output stream.
-type Encoder struct {
-	w          io.Writer
-	err        error
-	escapeHTML bool
-
-	indentBuf    *bytes.Buffer
-	indentPrefix string
-	indentValue  string
-}
-
-// NewEncoder returns a new encoder that writes to w.
-func NewEncoder(w io.Writer) *Encoder {
-	return &Encoder{w: w, escapeHTML: true}
-}
-
-// Encode writes the JSON encoding of v to the stream,
-// followed by a newline character.
-//
-// See the documentation for Marshal for details about the
-// conversion of Go values to JSON.
-func (enc *Encoder) Encode(v any) error {
-	if enc.err != nil {
-		return enc.err
-	}
-
-	e := newEncodeState()
-	defer encodeStatePool.Put(e)
-
-	err := e.marshal(v, encOpts{escapeHTML: enc.escapeHTML})
-	if err != nil {
-		return err
-	}
-
-	// Terminate each value with a newline.
-	// This makes the output look a little nicer
-	// when debugging, and some kind of space
-	// is required if the encoded value was a number,
-	// so that the reader knows there aren't more
-	// digits coming.
-	e.WriteByte('\n')
-
-	b := e.Bytes()
-	if enc.indentPrefix != "" || enc.indentValue != "" {
-		if enc.indentBuf == nil {
-			enc.indentBuf = new(bytes.Buffer)
-		}
-		enc.indentBuf.Reset()
-		err = Indent(enc.indentBuf, b, enc.indentPrefix, enc.indentValue)
-		if err != nil {
-			return err
-		}
-		b = enc.indentBuf.Bytes()
-	}
-	if _, err = enc.w.Write(b); err != nil {
-		enc.err = err
-	}
-	return err
-}
-
-// SetIndent instructs the encoder to format each subsequent encoded
-// value as if indented by the package-level function Indent(dst, src, prefix, indent).
-// Calling SetIndent("", "") disables indentation.
-func (enc *Encoder) SetIndent(prefix, indent string) {
-	enc.indentPrefix = prefix
-	enc.indentValue = indent
-}
-
-// SetEscapeHTML specifies whether problematic HTML characters
-// should be escaped inside JSON quoted strings.
-// The default behavior is to escape &, <, and > to \u0026, \u003c, and \u003e
-// to avoid certain safety problems that can arise when embedding JSON in HTML.
-//
-// In non-HTML settings where the escaping interferes with the readability
-// of the output, SetEscapeHTML(false) disables this behavior.
-func (enc *Encoder) SetEscapeHTML(on bool) {
-	enc.escapeHTML = on
-}
-
-// RawMessage is a raw encoded JSON value.
-// It implements Marshaler and Unmarshaler and can
-// be used to delay JSON decoding or precompute a JSON encoding.
-type RawMessage []byte
-
-// MarshalJSON returns m as the JSON encoding of m.
-func (m RawMessage) MarshalJSON() ([]byte, error) {
-	if m == nil {
-		return []byte("null"), nil
-	}
-	return m, nil
-}
-
-// UnmarshalJSON sets *m to a copy of data.
-func (m *RawMessage) UnmarshalJSON(data []byte) error {
-	if m == nil {
-		return errors.New("json.RawMessage: UnmarshalJSON on nil pointer")
-	}
-	*m = append((*m)[0:0], data...)
-	return nil
-}
-
-var (
-	_ Marshaler   = (*RawMessage)(nil)
-	_ Unmarshaler = (*RawMessage)(nil)
-)
-
-// A Token holds a value of one of these types:
-//
-//	Delim, for the four JSON delimiters [ ] { }
-//	bool, for JSON booleans
-//	float64, for JSON numbers
-//	Number, for JSON numbers
-//	string, for JSON string literals
-//	nil, for JSON null
-type Token any
-
-const (
-	tokenTopValue = iota
-	tokenArrayStart
-	tokenArrayValue
-	tokenArrayComma
-	tokenObjectStart
-	tokenObjectKey
-	tokenObjectColon
-	tokenObjectValue
-	tokenObjectComma
-)
-
-// advance tokenstate from a separator state to a value state
-func (dec *Decoder) tokenPrepareForDecode() error {
-	// Note: Not calling peek before switch, to avoid
-	// putting peek into the standard Decode path.
-	// peek is only called when using the Token API.
-	switch dec.tokenState {
-	case tokenArrayComma:
-		c, err := dec.peek()
-		if err != nil {
-			return err
-		}
-		if c != ',' {
-			return &SyntaxError{"expected comma after array element", dec.InputOffset()}
-		}
-		dec.scanp++
-		dec.tokenState = tokenArrayValue
-	case tokenObjectColon:
-		c, err := dec.peek()
-		if err != nil {
-			return err
-		}
-		if c != ':' {
-			return &SyntaxError{"expected colon after object key", dec.InputOffset()}
-		}
-		dec.scanp++
-		dec.tokenState = tokenObjectValue
-	}
-	return nil
-}
-
-func (dec *Decoder) tokenValueAllowed() bool {
-	switch dec.tokenState {
-	case tokenTopValue, tokenArrayStart, tokenArrayValue, tokenObjectValue:
-		return true
-	}
-	return false
-}
-
-func (dec *Decoder) tokenValueEnd() {
-	switch dec.tokenState {
-	case tokenArrayStart, tokenArrayValue:
-		dec.tokenState = tokenArrayComma
-	case tokenObjectValue:
-		dec.tokenState = tokenObjectComma
-	}
-}
-
-// A Delim is a JSON array or object delimiter, one of [ ] { or }.
-type Delim rune
-
-func (d Delim) String() string {
-	return string(d)
-}
-
-// Token returns the next JSON token in the input stream.
-// At the end of the input stream, Token returns nil, io.EOF.
-//
-// Token guarantees that the delimiters [ ] { } it returns are
-// properly nested and matched: if Token encounters an unexpected
-// delimiter in the input, it will return an error.
-//
-// The input stream consists of basic JSON values—bool, string,
-// number, and null—along with delimiters [ ] { } of type Delim
-// to mark the start and end of arrays and objects.
-// Commas and colons are elided.
-func (dec *Decoder) Token() (Token, error) {
-	for {
-		c, err := dec.peek()
-		if err != nil {
-			return nil, err
-		}
-		switch c {
-		case '[':
-			if !dec.tokenValueAllowed() {
-				return dec.tokenError(c)
-			}
-			dec.scanp++
-			dec.tokenStack = append(dec.tokenStack, dec.tokenState)
-			dec.tokenState = tokenArrayStart
-			return Delim('['), nil
-
-		case ']':
-			if dec.tokenState != tokenArrayStart && dec.tokenState != tokenArrayComma {
-				return dec.tokenError(c)
-			}
-			dec.scanp++
-			dec.tokenState = dec.tokenStack[len(dec.tokenStack)-1]
-			dec.tokenStack = dec.tokenStack[:len(dec.tokenStack)-1]
-			dec.tokenValueEnd()
-			return Delim(']'), nil
-
-		case '{':
-			if !dec.tokenValueAllowed() {
-				return dec.tokenError(c)
-			}
-			dec.scanp++
-			dec.tokenStack = append(dec.tokenStack, dec.tokenState)
-			dec.tokenState = tokenObjectStart
-			return Delim('{'), nil
-
-		case '}':
-			if dec.tokenState != tokenObjectStart && dec.tokenState != tokenObjectComma {
-				return dec.tokenError(c)
-			}
-			dec.scanp++
-			dec.tokenState = dec.tokenStack[len(dec.tokenStack)-1]
-			dec.tokenStack = dec.tokenStack[:len(dec.tokenStack)-1]
-			dec.tokenValueEnd()
-			return Delim('}'), nil
-
-		case ':':
-			if dec.tokenState != tokenObjectColon {
-				return dec.tokenError(c)
-			}
-			dec.scanp++
-			dec.tokenState = tokenObjectValue
-			continue
-
-		case ',':
-			if dec.tokenState == tokenArrayComma {
-				dec.scanp++
-				dec.tokenState = tokenArrayValue
-				continue
-			}
-			if dec.tokenState == tokenObjectComma {
-				dec.scanp++
-				dec.tokenState = tokenObjectKey
-				continue
-			}
-			return dec.tokenError(c)
-
-		case '"':
-			if dec.tokenState == tokenObjectStart || dec.tokenState == tokenObjectKey {
-				var x string
-				old := dec.tokenState
-				dec.tokenState = tokenTopValue
-				err := dec.Decode(&x)
-				dec.tokenState = old
-				if err != nil {
-					return nil, err
-				}
-				dec.tokenState = tokenObjectColon
-				return x, nil
-			}
-			fallthrough
-
-		default:
-			if !dec.tokenValueAllowed() {
-				return dec.tokenError(c)
-			}
-			var x any
-			if err := dec.Decode(&x); err != nil {
-				return nil, err
-			}
-			return x, nil
-		}
-	}
-}
-
-func (dec *Decoder) tokenError(c byte) (Token, error) {
-	var context string
-	switch dec.tokenState {
-	case tokenTopValue:
-		context = " looking for beginning of value"
-	case tokenArrayStart, tokenArrayValue, tokenObjectValue:
-		context = " looking for beginning of value"
-	case tokenArrayComma:
-		context = " after array element"
-	case tokenObjectKey:
-		context = " looking for beginning of object key string"
-	case tokenObjectColon:
-		context = " after object key"
-	case tokenObjectComma:
-		context = " after object key:value pair"
-	}
-	return nil, &SyntaxError{"invalid character " + quoteChar(c) + context, dec.InputOffset()}
-}
-
-// More reports whether there is another element in the
-// current array or object being parsed.
-func (dec *Decoder) More() bool {
-	c, err := dec.peek()
-	return err == nil && c != ']' && c != '}'
-}
-
-func (dec *Decoder) peek() (byte, error) {
-	var err error
-	for {
-		for i := dec.scanp; i < len(dec.buf); i++ {
-			c := dec.buf[i]
-			if isSpace(c) {
-				continue
-			}
-			dec.scanp = i
-			return c, nil
-		}
-		// buffer has been scanned, now report any error
-		if err != nil {
-			return 0, err
-		}
-		err = dec.refill()
-	}
-}
-
-// InputOffset returns the input stream byte offset of the current decoder position.
-// The offset gives the location of the end of the most recently returned token
-// and the beginning of the next token.
-func (dec *Decoder) InputOffset() int64 {
-	return dec.scanned + int64(dec.scanp)
-}

common/json/internal/contextjson_120/tables.go

@@ -1,218 +0,0 @@
-// Copyright 2016 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package json
-
-import "unicode/utf8"
-
-// safeSet holds the value true if the ASCII character with the given array
-// position can be represented inside a JSON string without any further
-// escaping.
-//
-// All values are true except for the ASCII control characters (0-31), the
-// double quote ("), and the backslash character ("\").
-var safeSet = [utf8.RuneSelf]bool{
-	' ':      true,
-	'!':      true,
-	'"':      false,
-	'#':      true,
-	'$':      true,
-	'%':      true,
-	'&':      true,
-	'\'':     true,
-	'(':      true,
-	')':      true,
-	'*':      true,
-	'+':      true,
-	',':      true,
-	'-':      true,
-	'.':      true,
-	'/':      true,
-	'0':      true,
-	'1':      true,
-	'2':      true,
-	'3':      true,
-	'4':      true,
-	'5':      true,
-	'6':      true,
-	'7':      true,
-	'8':      true,
-	'9':      true,
-	':':      true,
-	';':      true,
-	'<':      true,
-	'=':      true,
-	'>':      true,
-	'?':      true,
-	'@':      true,
-	'A':      true,
-	'B':      true,
-	'C':      true,
-	'D':      true,
-	'E':      true,
-	'F':      true,
-	'G':      true,
-	'H':      true,
-	'I':      true,
-	'J':      true,
-	'K':      true,
-	'L':      true,
-	'M':      true,
-	'N':      true,
-	'O':      true,
-	'P':      true,
-	'Q':      true,
-	'R':      true,
-	'S':      true,
-	'T':      true,
-	'U':      true,
-	'V':      true,
-	'W':      true,
-	'X':      true,
-	'Y':      true,
-	'Z':      true,
-	'[':      true,
-	'\\':     false,
-	']':      true,
-	'^':      true,
-	'_':      true,
-	'`':      true,
-	'a':      true,
-	'b':      true,
-	'c':      true,
-	'd':      true,
-	'e':      true,
-	'f':      true,
-	'g':      true,
-	'h':      true,
-	'i':      true,
-	'j':      true,
-	'k':      true,
-	'l':      true,
-	'm':      true,
-	'n':      true,
-	'o':      true,
-	'p':      true,
-	'q':      true,
-	'r':      true,
-	's':      true,
-	't':      true,
-	'u':      true,
-	'v':      true,
-	'w':      true,
-	'x':      true,
-	'y':      true,
-	'z':      true,
-	'{':      true,
-	'|':      true,
-	'}':      true,
-	'~':      true,
-	'\u007f': true,
-}
-
-// htmlSafeSet holds the value true if the ASCII character with the given
-// array position can be safely represented inside a JSON string, embedded
-// inside of HTML <script> tags, without any additional escaping.
-//
-// All values are true except for the ASCII control characters (0-31), the
-// double quote ("), the backslash character ("\"), HTML opening and closing
-// tags ("<" and ">"), and the ampersand ("&").
-var htmlSafeSet = [utf8.RuneSelf]bool{
-	' ':      true,
-	'!':      true,
-	'"':      false,
-	'#':      true,
-	'$':      true,
-	'%':      true,
-	'&':      false,
-	'\'':     true,
-	'(':      true,
-	')':      true,
-	'*':      true,
-	'+':      true,
-	',':      true,
-	'-':      true,
-	'.':      true,
-	'/':      true,
-	'0':      true,
-	'1':      true,
-	'2':      true,
-	'3':      true,
-	'4':      true,
-	'5':      true,
-	'6':      true,
-	'7':      true,
-	'8':      true,
-	'9':      true,
-	':':      true,
-	';':      true,
-	'<':      false,
-	'=':      true,
-	'>':      false,
-	'?':      true,
-	'@':      true,
-	'A':      true,
-	'B':      true,
-	'C':      true,
-	'D':      true,
-	'E':      true,
-	'F':      true,
-	'G':      true,
-	'H':      true,
-	'I':      true,
-	'J':      true,
-	'K':      true,
-	'L':      true,
-	'M':      true,
-	'N':      true,
-	'O':      true,
-	'P':      true,
-	'Q':      true,
-	'R':      true,
-	'S':      true,
-	'T':      true,
-	'U':      true,
-	'V':      true,
-	'W':      true,
-	'X':      true,
-	'Y':      true,
-	'Z':      true,
-	'[':      true,
-	'\\':     false,
-	']':      true,
-	'^':      true,
-	'_':      true,
-	'`':      true,
-	'a':      true,
-	'b':      true,
-	'c':      true,
-	'd':      true,
-	'e':      true,
-	'f':      true,
-	'g':      true,
-	'h':      true,
-	'i':      true,
-	'j':      true,
-	'k':      true,
-	'l':      true,
-	'm':      true,
-	'n':      true,
-	'o':      true,
-	'p':      true,
-	'q':      true,
-	'r':      true,
-	's':      true,
-	't':      true,
-	'u':      true,
-	'v':      true,
-	'w':      true,
-	'x':      true,
-	'y':      true,
-	'z':      true,
-	'{':      true,
-	'|':      true,
-	'}':      true,
-	'~':      true,
-	'\u007f': true,
-}

common/json/internal/contextjson_120/tags.go

@@ -1,38 +0,0 @@
-// Copyright 2011 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package json
-
-import (
-	"strings"
-)
-
-// tagOptions is the string following a comma in a struct field's "json"
-// tag, or the empty string. It does not include the leading comma.
-type tagOptions string
-
-// parseTag splits a struct field's json tag into its name and
-// comma-separated options.
-func parseTag(tag string) (string, tagOptions) {
-	tag, opt, _ := strings.Cut(tag, ",")
-	return tag, tagOptions(opt)
-}
-
-// Contains reports whether a comma-separated list of options
-// contains a particular substr flag. substr must be surrounded by a
-// string boundary or commas.
-func (o tagOptions) Contains(optionName string) bool {
-	if len(o) == 0 {
-		return false
-	}
-	s := string(o)
-	for s != "" {
-		var name string
-		name, s, _ = strings.Cut(s, ",")
-		if name == optionName {
-			return true
-		}
-	}
-	return false
-}

go.mod

@@ -1,6 +1,6 @@
 module github.com/sagernet/sing
 
-go 1.18
+go 1.20
 
 require (
 	github.com/stretchr/testify v1.9.0