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package dhcpv6
import (
"fmt"
"github.com/u-root/u-root/pkg/uio"
)
// Option is an interface that all DHCPv6 options adhere to.
type Option interface {
Code() OptionCode
ToBytes() []byte
String() string
}
type OptionGeneric struct {
OptionCode OptionCode
OptionData []byte
}
func (og *OptionGeneric) Code() OptionCode {
return og.OptionCode
}
func (og *OptionGeneric) ToBytes() []byte {
return og.OptionData
}
func (og *OptionGeneric) String() string {
return fmt.Sprintf("%s -> %v", og.OptionCode, og.OptionData)
}
// ParseOption parses data according to the given code.
func ParseOption(code OptionCode, optData []byte) (Option, error) {
// Parse a sequence of bytes as a single DHCPv6 option.
// Returns the option structure, or an error if any.
var (
err error
opt Option
)
switch code {
case OptionClientID:
opt, err = parseOptClientID(optData)
case OptionServerID:
opt, err = parseOptServerID(optData)
case OptionIANA:
opt, err = ParseOptIANA(optData)
case OptionIAAddr:
opt, err = ParseOptIAAddress(optData)
case OptionORO:
var o optRequestedOption
err = o.FromBytes(optData)
opt = &o
case OptionElapsedTime:
opt, err = parseOptElapsedTime(optData)
case OptionRelayMsg:
opt, err = parseOptRelayMsg(optData)
case OptionStatusCode:
opt, err = ParseOptStatusCode(optData)
case OptionUserClass:
opt, err = ParseOptUserClass(optData)
case OptionVendorClass:
opt, err = ParseOptVendorClass(optData)
case OptionVendorOpts:
opt, err = ParseOptVendorOpts(optData)
case OptionInterfaceID:
opt, err = parseOptInterfaceID(optData)
case OptionDNSRecursiveNameServer:
opt, err = parseOptDNS(optData)
case OptionDomainSearchList:
opt, err = parseOptDomainSearchList(optData)
case OptionIAPD:
opt, err = ParseOptIAForPrefixDelegation(optData)
case OptionIAPrefix:
opt, err = ParseOptIAPrefix(optData)
case OptionRemoteID:
opt, err = ParseOptRemoteId(optData)
case OptionFQDN:
opt, err = ParseOptFQDN(optData)
case OptionBootfileURL:
opt, err = parseOptBootFileURL(optData)
case OptionBootfileParam:
opt, err = parseOptBootFileParam(optData)
case OptionClientArchType:
opt, err = parseOptClientArchType(optData)
case OptionNII:
var o OptNetworkInterfaceID
err = o.FromBytes(optData)
opt = &o
case OptionDHCPv4Msg:
opt, err = ParseOptDHCPv4Msg(optData)
case OptionDHCP4oDHCP6Server:
opt, err = ParseOptDHCP4oDHCP6Server(optData)
case Option4RD:
opt, err = ParseOpt4RD(optData)
case Option4RDMapRule:
opt, err = ParseOpt4RDMapRule(optData)
case Option4RDNonMapRule:
opt, err = ParseOpt4RDNonMapRule(optData)
default:
opt = &OptionGeneric{OptionCode: code, OptionData: optData}
}
if err != nil {
return nil, err
}
return opt, nil
}
// Options is a collection of options.
type Options []Option
// Get returns all options matching the option code.
func (o Options) Get(code OptionCode) []Option {
var ret []Option
for _, opt := range o {
if opt.Code() == code {
ret = append(ret, opt)
}
}
return ret
}
// GetOne returns the first option matching the option code.
func (o Options) GetOne(code OptionCode) Option {
for _, opt := range o {
if opt.Code() == code {
return opt
}
}
return nil
}
// Add appends one option.
func (o *Options) Add(option Option) {
*o = append(*o, option)
}
// Del deletes all options matching the option code.
func (o *Options) Del(code OptionCode) {
newOpts := make(Options, 0, len(*o))
for _, opt := range *o {
if opt.Code() != code {
newOpts = append(newOpts, opt)
}
}
*o = newOpts
}
// Update replaces the first option of the same type as the specified one.
func (o *Options) Update(option Option) {
for idx, opt := range *o {
if opt.Code() == option.Code() {
(*o)[idx] = option
// don't look further
return
}
}
// if not found, add it
o.Add(option)
}
// ToBytes marshals all options to bytes.
func (o Options) ToBytes() []byte {
buf := uio.NewBigEndianBuffer(nil)
for _, opt := range o {
buf.Write16(uint16(opt.Code()))
val := opt.ToBytes()
buf.Write16(uint16(len(val)))
buf.WriteBytes(val)
}
return buf.Data()
}
// FromBytes reads data into o and returns an error if the options are not a
// valid serialized representation of DHCPv6 options per RFC 3315.
func (o *Options) FromBytes(data []byte) error {
return o.FromBytesWithParser(data, ParseOption)
}
// OptionParser is a function signature for option parsing
type OptionParser func(code OptionCode, data []byte) (Option, error)
// FromBytesWithParser parses Options from byte sequences using the parsing
// function that is passed in as a paremeter
func (o *Options) FromBytesWithParser(data []byte, parser OptionParser) error {
*o = make(Options, 0, 10)
if len(data) == 0 {
// no options, no party
return nil
}
buf := uio.NewBigEndianBuffer(data)
for buf.Has(4) {
code := OptionCode(buf.Read16())
length := int(buf.Read16())
// Consume, but do not Copy. Each parser will make a copy of
// pertinent data.
optData := buf.Consume(length)
opt, err := parser(code, optData)
if err != nil {
return err
}
*o = append(*o, opt)
}
return buf.FinError()
}
|
