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package dhcpv4
// This module defines the OptDomainSearch structure.
// https://tools.ietf.org/html/rfc3397
import (
"fmt"
"github.com/insomniacslk/dhcp/rfc1035label"
)
// OptDomainSearch represents an option encapsulating a domain search list.
type OptDomainSearch struct {
DomainSearch []string
}
// Code returns the option code.
func (op *OptDomainSearch) Code() OptionCode {
return OptionDNSDomainSearchList
}
// ToBytes returns a serialized stream of bytes for this option.
func (op *OptDomainSearch) ToBytes() []byte {
buf := []byte{byte(op.Code()), byte(op.Length())}
buf = append(buf, rfc1035label.LabelsToBytes(op.DomainSearch)...)
return buf
}
// Length returns the length of the data portion (excluding option code an byte
// length).
func (op *OptDomainSearch) Length() int {
var length int
for _, label := range op.DomainSearch {
length += len(label) + 2 // add the first and the last length bytes
}
return length
}
// String returns a human-readable string.
func (op *OptDomainSearch) String() string {
return fmt.Sprintf("DNS Domain Search List -> %v", op.DomainSearch)
}
// ParseOptDomainSearch returns a new OptDomainSearch from a byte stream, or
// error if any.
func ParseOptDomainSearch(data []byte) (*OptDomainSearch, error) {
if len(data) < 2 {
return nil, ErrShortByteStream
}
code := OptionCode(data[0])
if code != OptionDNSDomainSearchList {
return nil, fmt.Errorf("expected code %v, got %v", OptionDNSDomainSearchList, code)
}
length := int(data[1])
if len(data) < 2+length {
return nil, ErrShortByteStream
}
domainSearch, err := rfc1035label.LabelsFromBytes(data[2:length+2])
if err != nil {
return nil, err
}
return &OptDomainSearch{DomainSearch: domainSearch}, nil
}
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