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
|
package dhcpv4
import (
"bytes"
"fmt"
"github.com/u-root/u-root/pkg/uio"
)
// This option implements the Vendor-Identifying Vendor Class Option
// https://tools.ietf.org/html/rfc3925
// VIVCIdentifier represents one Vendor-Identifying vendor class option.
type VIVCIdentifier struct {
EntID uint32
Data []byte
}
// OptVIVC represents the DHCP message type option.
type OptVIVC struct {
Identifiers []VIVCIdentifier
}
// ParseOptVIVC contructs an OptVIVC tsruct from a sequence of bytes and returns
// it, or an error.
func ParseOptVIVC(data []byte) (*OptVIVC, error) {
buf := uio.NewBigEndianBuffer(data)
var ids []VIVCIdentifier
for buf.Has(5) {
entID := buf.Read32()
idLen := int(buf.Read8())
ids = append(ids, VIVCIdentifier{EntID: entID, Data: buf.CopyN(idLen)})
}
return &OptVIVC{Identifiers: ids}, buf.FinError()
}
// Code returns the option code.
func (o *OptVIVC) Code() OptionCode {
return OptionVendorIdentifyingVendorClass
}
// ToBytes returns a serialized stream of bytes for this option.
func (o *OptVIVC) ToBytes() []byte {
buf := uio.NewBigEndianBuffer(nil)
for _, id := range o.Identifiers {
buf.Write32(id.EntID)
buf.Write8(uint8(len(id.Data)))
buf.WriteBytes(id.Data)
}
return buf.Data()
}
// String returns a human-readable string for this option.
func (o *OptVIVC) String() string {
buf := bytes.Buffer{}
fmt.Fprintf(&buf, "Vendor-Identifying Vendor Class ->")
for _, id := range o.Identifiers {
fmt.Fprintf(&buf, " %d:'%s',", id.EntID, id.Data)
}
return buf.String()[:buf.Len()-1]
}
// Length returns the length of the data portion (excluding option code and byte
// for length, if any).
func (o *OptVIVC) Length() int {
n := 0
for _, id := range o.Identifiers {
// each class has a header of endID (4 bytes) and length (1 byte)
n += 5 + len(id.Data)
}
return n
}
|
