forked from quic-go/quic-go
/
frames.go
164 lines (147 loc) · 3.7 KB
/
frames.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
package http3
import (
"bytes"
"errors"
"fmt"
"io"
"github.com/btwiuse/quic/internal/protocol"
"github.com/btwiuse/quic/quicvarint"
)
// FrameType is the frame type of a HTTP/3 frame
type FrameType uint64
type unknownFrameHandlerFunc func(FrameType, error) (processed bool, err error)
type frame interface{}
var errHijacked = errors.New("hijacked")
func parseNextFrame(r io.Reader, unknownFrameHandler unknownFrameHandlerFunc) (frame, error) {
qr := quicvarint.NewReader(r)
for {
t, err := quicvarint.Read(qr)
if err != nil {
if unknownFrameHandler != nil {
hijacked, err := unknownFrameHandler(0, err)
if err != nil {
return nil, err
}
if hijacked {
return nil, errHijacked
}
}
return nil, err
}
// Call the unknownFrameHandler for frames not defined in the HTTP/3 spec
if t > 0xd && unknownFrameHandler != nil {
hijacked, err := unknownFrameHandler(FrameType(t), nil)
if err != nil {
return nil, err
}
if hijacked {
return nil, errHijacked
}
// If the unknownFrameHandler didn't process the frame, it is our responsibility to skip it.
}
l, err := quicvarint.Read(qr)
if err != nil {
return nil, err
}
switch t {
case 0x0:
return &dataFrame{Length: l}, nil
case 0x1:
return &headersFrame{Length: l}, nil
case 0x4:
return parseSettingsFrame(r, l)
case 0x3: // CANCEL_PUSH
case 0x5: // PUSH_PROMISE
case 0x7: // GOAWAY
case 0xd: // MAX_PUSH_ID
}
// skip over unknown frames
if _, err := io.CopyN(io.Discard, qr, int64(l)); err != nil {
return nil, err
}
}
}
type dataFrame struct {
Length uint64
}
func (f *dataFrame) Append(b []byte) []byte {
b = quicvarint.Append(b, 0x0)
return quicvarint.Append(b, f.Length)
}
type headersFrame struct {
Length uint64
}
func (f *headersFrame) Append(b []byte) []byte {
b = quicvarint.Append(b, 0x1)
return quicvarint.Append(b, f.Length)
}
const settingDatagram = 0xffd277
type settingsFrame struct {
Datagram bool
Other map[uint64]uint64 // all settings that we don't explicitly recognize
}
func parseSettingsFrame(r io.Reader, l uint64) (*settingsFrame, error) {
if l > 8*(1<<10) {
return nil, fmt.Errorf("unexpected size for SETTINGS frame: %d", l)
}
buf := make([]byte, l)
if _, err := io.ReadFull(r, buf); err != nil {
if err == io.ErrUnexpectedEOF {
return nil, io.EOF
}
return nil, err
}
frame := &settingsFrame{}
b := bytes.NewReader(buf)
var readDatagram bool
for b.Len() > 0 {
id, err := quicvarint.Read(b)
if err != nil { // should not happen. We allocated the whole frame already.
return nil, err
}
val, err := quicvarint.Read(b)
if err != nil { // should not happen. We allocated the whole frame already.
return nil, err
}
switch id {
case settingDatagram:
if readDatagram {
return nil, fmt.Errorf("duplicate setting: %d", id)
}
readDatagram = true
if val != 0 && val != 1 {
return nil, fmt.Errorf("invalid value for H3_DATAGRAM: %d", val)
}
frame.Datagram = val == 1
default:
if _, ok := frame.Other[id]; ok {
return nil, fmt.Errorf("duplicate setting: %d", id)
}
if frame.Other == nil {
frame.Other = make(map[uint64]uint64)
}
frame.Other[id] = val
}
}
return frame, nil
}
func (f *settingsFrame) Append(b []byte) []byte {
b = quicvarint.Append(b, 0x4)
var l protocol.ByteCount
for id, val := range f.Other {
l += quicvarint.Len(id) + quicvarint.Len(val)
}
if f.Datagram {
l += quicvarint.Len(settingDatagram) + quicvarint.Len(1)
}
b = quicvarint.Append(b, uint64(l))
if f.Datagram {
b = quicvarint.Append(b, settingDatagram)
b = quicvarint.Append(b, 1)
}
for id, val := range f.Other {
b = quicvarint.Append(b, id)
b = quicvarint.Append(b, val)
}
return b
}