1// Copyright 2019 The gRPC Authors
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15package http2interop
16
17import (
18	"encoding/binary"
19	"fmt"
20	"io"
21)
22
23type GoAwayFrame struct {
24	Header FrameHeader
25	Reserved
26	StreamID
27	// TODO(carl-mastrangelo): make an enum out of this.
28	Code uint32
29	Data []byte
30}
31
32func (f *GoAwayFrame) GetHeader() *FrameHeader {
33	return &f.Header
34}
35
36func (f *GoAwayFrame) ParsePayload(r io.Reader) error {
37	raw := make([]byte, f.Header.Length)
38	if _, err := io.ReadFull(r, raw); err != nil {
39		return err
40	}
41	return f.UnmarshalPayload(raw)
42}
43
44func (f *GoAwayFrame) UnmarshalPayload(raw []byte) error {
45	if f.Header.Length != len(raw) {
46		return fmt.Errorf("Invalid Payload length %d != %d", f.Header.Length, len(raw))
47	}
48	if f.Header.Length < 8 {
49		return fmt.Errorf("Invalid Payload length %d", f.Header.Length)
50	}
51	*f = GoAwayFrame{
52		Reserved: Reserved(raw[0]>>7 == 1),
53		StreamID: StreamID(binary.BigEndian.Uint32(raw[0:4]) & 0x7fffffff),
54		Code:     binary.BigEndian.Uint32(raw[4:8]),
55		Data:     []byte(string(raw[8:])),
56	}
57
58	return nil
59}
60
61func (f *GoAwayFrame) MarshalPayload() ([]byte, error) {
62	raw := make([]byte, 8, 8+len(f.Data))
63	binary.BigEndian.PutUint32(raw[:4], uint32(f.StreamID))
64	binary.BigEndian.PutUint32(raw[4:8], f.Code)
65	raw = append(raw, f.Data...)
66
67	return raw, nil
68}
69
70func (f *GoAwayFrame) MarshalBinary() ([]byte, error) {
71	payload, err := f.MarshalPayload()
72	if err != nil {
73		return nil, err
74	}
75
76	f.Header.Length = len(payload)
77	f.Header.Type = GoAwayFrameType
78	header, err := f.Header.MarshalBinary()
79	if err != nil {
80		return nil, err
81	}
82
83	header = append(header, payload...)
84
85	return header, nil
86}
87