forked from scionproto/scion
/
meta.go
70 lines (60 loc) · 1.73 KB
/
meta.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
// Copyright 2016 ETH Zurich
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package scmp
import (
"encoding/binary"
"fmt"
"gopkg.in/restruct.v1"
"github.com/scionproto/scion/go/lib/common"
)
type Meta struct {
InfoLen uint8
CmnHdrLen uint8
AddrHdrLen uint8
PathHdrLen uint8
ExtHdrsLen uint8
L4HdrLen uint8
L4Proto common.L4ProtocolType
}
const (
MetaLen = 8
)
func MetaFromRaw(b []byte) (*Meta, error) {
m := &Meta{}
if err := restruct.Unpack(b, binary.BigEndian, m); err != nil {
return nil, common.NewBasicError("Failed to unpack SCMP Metadata", err)
}
return m, nil
}
func (m *Meta) Copy() *Meta {
return &Meta{
InfoLen: m.InfoLen, CmnHdrLen: m.CmnHdrLen, AddrHdrLen: m.AddrHdrLen,
PathHdrLen: m.PathHdrLen, ExtHdrsLen: m.ExtHdrsLen,
L4HdrLen: m.L4HdrLen, L4Proto: m.L4Proto,
}
}
func (m *Meta) Write(b common.RawBytes) error {
out, err := restruct.Pack(common.Order, m)
if err != nil {
return common.NewBasicError("Error packing SCMP Metadata", err)
}
copy(b, out)
return nil
}
func (m *Meta) String() string {
return fmt.Sprintf(
"Info=%d CmnHdr=%d AddrHdr=%d PathHdr=%d ExtHdrs=%d L4Hdr=%d L4Proto=%v",
m.InfoLen, m.CmnHdrLen, m.AddrHdrLen, m.PathHdrLen, m.ExtHdrsLen, m.L4HdrLen, m.L4Proto,
)
}