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package dhcpv6
import (
"encoding/binary"
"errors"
"fmt"
"strings"
)
// OptVendorClass represents a DHCPv6 Vendor Class option
type OptVendorClass struct {
EnterpriseNumber uint32
Data [][]byte
}
// Code returns the option code
func (op *OptVendorClass) Code() OptionCode {
return OptionVendorClass
}
// ToBytes serializes the option and returns it as a sequence of bytes
func (op *OptVendorClass) ToBytes() []byte {
buf := make([]byte, 8)
binary.BigEndian.PutUint16(buf[0:2], uint16(OptionVendorClass))
binary.BigEndian.PutUint16(buf[2:4], uint16(op.Length()))
binary.BigEndian.PutUint32(buf[4:8], uint32(op.EnterpriseNumber))
u16 := make([]byte, 2)
for _, data := range op.Data {
binary.BigEndian.PutUint16(u16, uint16(len(data)))
buf = append(buf, u16...)
buf = append(buf, data...)
}
return buf
}
// Length returns the option length
func (op *OptVendorClass) Length() int {
ret := 0
for _, data := range op.Data {
ret += 2 + len(data)
}
return 4 + ret
}
// String returns a string representation of the VendorClass data
func (op *OptVendorClass) String() string {
vcStrings := make([]string, 0)
for _, data := range op.Data {
vcStrings = append(vcStrings, string(data))
}
return fmt.Sprintf("OptVendorClass{enterprisenum=%d, data=[%s]}", op.EnterpriseNumber, strings.Join(vcStrings, ", "))
}
// ParseOptVendorClass builds an OptVendorClass structure from a sequence of
// bytes. The input data does not include option code and length bytes.
func ParseOptVendorClass(data []byte) (*OptVendorClass, error) {
opt := OptVendorClass{}
if len(data) < 4 {
return nil, fmt.Errorf("Invalid vendor opts data length. Expected at least 4 bytes, got %v", len(data))
}
opt.EnterpriseNumber = binary.BigEndian.Uint32(data[:4])
data = data[4:]
for {
if len(data) == 0 {
break
}
if len(data) < 2 {
return nil, errors.New("ParseOptVendorClass: short data: missing length field")
}
vcLen := int(binary.BigEndian.Uint16(data[:2]))
if len(data) < vcLen+2 {
return nil, fmt.Errorf("ParseOptVendorClass: short data: less than %d bytes", vcLen+2)
}
opt.Data = append(opt.Data, data[2:vcLen+2])
data = data[2+vcLen:]
}
if len(opt.Data) < 1 {
return nil, errors.New("ParseOptVendorClass: at least one vendor class data is required")
}
return &opt, nil
}
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