v6: RequestedOptions getter

Signed-off-by: Chris Koch <chrisko@google.com>

1 files changed, 46 insertions, 35 deletions

diff --git a/dhcpv6/option_requestedoption.go b/dhcpv6/option_requestedoption.go
index 54ff5bf..0d16c74 100644
--- a/dhcpv6/option_requestedoption.go
+++ b/dhcpv6/option_requestedoption.go
@@ -7,58 +7,69 @@ import (
 	"github.com/u-root/u-root/pkg/uio"
 )
 
-// OptRequestedOption implements the requested options option.
-//
-// This module defines the OptRequestedOption structure.
-// https://www.ietf.org/rfc/rfc3315.txt
-type OptRequestedOption struct {
-	requestedOptions []OptionCode
+// OptionCodes are a collection of option codes.
+type OptionCodes []OptionCode
+
+// Add adds an option to the list, ignoring duplicates.
+func (o *OptionCodes) Add(c OptionCode) {
+	if !o.Contains(c) {
+		*o = append(*o, c)
+	}
 }
 
-func (op *OptRequestedOption) Code() OptionCode {
-	return OptionORO
+// Contains returns whether the option codes contain c.
+func (o OptionCodes) Contains(c OptionCode) bool {
+	for _, oo := range o {
+		if oo == c {
+			return true
+		}
+	}
+	return false
 }
 
-func (op *OptRequestedOption) ToBytes() []byte {
+// ToBytes implements Option.ToBytes.
+func (o OptionCodes) ToBytes() []byte {
 	buf := uio.NewBigEndianBuffer(nil)
-	for _, ro := range op.requestedOptions {
+	for _, ro := range o {
 		buf.Write16(uint16(ro))
 	}
 	return buf.Data()
 }
 
-func (op *OptRequestedOption) RequestedOptions() []OptionCode {
-	return op.requestedOptions
+func (o OptionCodes) String() string {
+	names := make([]string, 0, len(o))
+	for _, code := range o {
+		names = append(names, code.String())
+	}
+	return strings.Join(names, ", ")
 }
 
-func (op *OptRequestedOption) SetRequestedOptions(opts []OptionCode) {
-	op.requestedOptions = opts
+// FromBytes populates o from binary-encoded data.
+func (o *OptionCodes) FromBytes(data []byte) error {
+	buf := uio.NewBigEndianBuffer(data)
+	for buf.Has(2) {
+		o.Add(OptionCode(buf.Read16()))
+	}
+	return buf.FinError()
 }
 
-func (op *OptRequestedOption) AddRequestedOption(opt OptionCode) {
-	for _, requestedOption := range op.requestedOptions {
-		if opt == requestedOption {
-			fmt.Printf("Warning: option %s is already set, appending duplicate", opt)
-		}
+// OptRequestedOption implements the requested options option as defined by RFC
+// 3315 Section 22.7.
+func OptRequestedOption(o ...OptionCode) Option {
+	return &optRequestedOption{
+		OptionCodes: o,
 	}
-	op.requestedOptions = append(op.requestedOptions, opt)
 }
 
-func (op *OptRequestedOption) String() string {
-	names := make([]string, 0, len(op.requestedOptions))
-	for _, code := range op.requestedOptions {
-		names = append(names, code.String())
-	}
-	return fmt.Sprintf("OptRequestedOption{options=[%v]}", strings.Join(names, ", "))
+type optRequestedOption struct {
+	OptionCodes
 }
 
-// build an OptRequestedOption structure from a sequence of bytes.
-// The input data does not include option code and length bytes.
-func ParseOptRequestedOption(data []byte) (*OptRequestedOption, error) {
-	var opt OptRequestedOption
-	buf := uio.NewBigEndianBuffer(data)
-	for buf.Has(2) {
-		opt.requestedOptions = append(opt.requestedOptions, OptionCode(buf.Read16()))
-	}
-	return &opt, buf.FinError()
+// Code implements Option.Code.
+func (*optRequestedOption) Code() OptionCode {
+	return OptionORO
+}
+
+func (op *optRequestedOption) String() string {
+	return fmt.Sprintf("RequestedOptions: %s", op.OptionCodes)
 }