dhcpv4: simplify marshaling options to binary.

- Consolidate writing the option code and length to Options.Marshal
  rather than doing it in each individual option.
- Use uio in marshaling code.

25 files changed, 53 insertions, 70 deletions

diff --git a/dhcpv4/bsdp/boot_image.go b/dhcpv4/bsdp/boot_image.go
index fa9b1a6..954dcb6 100644
--- a/dhcpv4/bsdp/boot_image.go
+++ b/dhcpv4/bsdp/boot_image.go
@@ -1,7 +1,6 @@
 package bsdp
 
 import (
-	"encoding/binary"
 	"fmt"
 
 	"github.com/u-root/u-root/pkg/uio"
@@ -36,15 +35,16 @@ type BootImageID struct {
 	Index     uint16
 }
 
-// ToBytes serializes a BootImageID to network-order bytes.
-func (b BootImageID) ToBytes() []byte {
-	bytes := make([]byte, 4)
+// Marshal writes the binary representation to buf.
+func (b BootImageID) Marshal(buf *uio.Lexer) {
+	var byte0 byte
 	if b.IsInstall {
-		bytes[0] |= 0x80
+		byte0 |= 0x80
 	}
-	bytes[0] |= byte(b.ImageType)
-	binary.BigEndian.PutUint16(bytes[2:], b.Index)
-	return bytes
+	byte0 |= byte(b.ImageType)
+	buf.Write8(byte0)
+	buf.Write8(byte(0))
+	buf.Write16(b.Index)
 }
 
 // String converts a BootImageID to a human-readable representation.
@@ -78,12 +78,11 @@ type BootImage struct {
 	Name string
 }
 
-// ToBytes converts a BootImage to a slice of bytes.
-func (b *BootImage) ToBytes() []byte {
-	bytes := b.ID.ToBytes()
-	bytes = append(bytes, byte(len(b.Name)))
-	bytes = append(bytes, []byte(b.Name)...)
-	return bytes
+// Marshal write a BootImage to buf.
+func (b BootImage) Marshal(buf *uio.Lexer) {
+	b.ID.Marshal(buf)
+	buf.Write8(uint8(len(b.Name)))
+	buf.WriteBytes([]byte(b.Name))
 }
 
 // String converts a BootImage to a human-readable representation.
diff --git a/dhcpv4/bsdp/boot_image_test.go b/dhcpv4/bsdp/boot_image_test.go
index d8e3aeb..996b8a0 100644
--- a/dhcpv4/bsdp/boot_image_test.go
+++ b/dhcpv4/bsdp/boot_image_test.go
@@ -13,12 +13,12 @@ func TestBootImageIDToBytes(t *testing.T) {
 		ImageType: BootImageTypeMacOSX,
 		Index:     0x1000,
 	}
-	actual := b.ToBytes()
+	actual := uio.ToBigEndian(b)
 	expected := []byte{0x81, 0, 0x10, 0}
 	require.Equal(t, expected, actual)
 
 	b.IsInstall = false
-	actual = b.ToBytes()
+	actual = uio.ToBigEndian(b)
 	expected = []byte{0x01, 0, 0x10, 0}
 	require.Equal(t, expected, actual)
 }
@@ -30,7 +30,7 @@ func TestBootImageIDFromBytes(t *testing.T) {
 		Index:     0x1000,
 	}
 	var newBootImage BootImageID
-	require.NoError(t, uio.FromBigEndian(&newBootImage, b.ToBytes()))
+	require.NoError(t, uio.FromBigEndian(&newBootImage, uio.ToBigEndian(b)))
 	require.Equal(t, b, newBootImage)
 
 	b = BootImageID{
@@ -38,7 +38,7 @@ func TestBootImageIDFromBytes(t *testing.T) {
 		ImageType: BootImageTypeMacOSX,
 		Index:     0x1011,
 	}
-	require.NoError(t, uio.FromBigEndian(&newBootImage, b.ToBytes()))
+	require.NoError(t, uio.FromBigEndian(&newBootImage, uio.ToBigEndian(b)))
 	require.Equal(t, b, newBootImage)
 }
 
@@ -70,7 +70,7 @@ func TestBootImageToBytes(t *testing.T) {
 		6,                         // len(Name)
 		98, 115, 100, 112, 45, 49, // byte-encoding of Name
 	}
-	actual := b.ToBytes()
+	actual := uio.ToBigEndian(b)
 	require.Equal(t, expected, actual)
 
 	b = BootImage{
@@ -86,7 +86,7 @@ func TestBootImageToBytes(t *testing.T) {
 		7,                             // len(Name)
 		98, 115, 100, 112, 45, 50, 49, // byte-encoding of Name
 	}
-	actual = b.ToBytes()
+	actual = uio.ToBigEndian(b)
 	require.Equal(t, expected, actual)
 }
 
diff --git a/dhcpv4/bsdp/bsdp.go b/dhcpv4/bsdp/bsdp.go
index 6bc0cfd..12f3c06 100644
--- a/dhcpv4/bsdp/bsdp.go
+++ b/dhcpv4/bsdp/bsdp.go
@@ -36,7 +36,7 @@ func ParseBootImageListFromAck(ack dhcpv4.DHCPv4) ([]BootImage, error) {
 	if opt == nil {
 		return nil, errors.New("ParseBootImageListFromAck: could not find vendor-specific option")
 	}
-	vendorOpt, err := ParseOptVendorSpecificInformation(opt.ToBytes()[2:])
+	vendorOpt, err := ParseOptVendorSpecificInformation(opt.ToBytes())
 	if err != nil {
 		return nil, err
 	}
@@ -60,7 +60,7 @@ func MessageTypeFromPacket(packet *dhcpv4.DHCPv4) *MessageType {
 		err        error
 	)
 	for _, opt := range packet.GetOption(dhcpv4.OptionVendorSpecificInformation) {
-		if vendorOpts, err = ParseOptVendorSpecificInformation(opt.ToBytes()[2:]); err == nil {
+		if vendorOpts, err = ParseOptVendorSpecificInformation(opt.ToBytes()); err == nil {
 			if o := vendorOpts.GetOneOption(OptionMessageType); o != nil {
 				if optMessageType, ok := o.(*OptMessageType); ok {
 					return &optMessageType.Type
diff --git a/dhcpv4/bsdp/bsdp_option_boot_image_list.go b/dhcpv4/bsdp/bsdp_option_boot_image_list.go
index d018655..ae2e59e 100644
--- a/dhcpv4/bsdp/bsdp_option_boot_image_list.go
+++ b/dhcpv4/bsdp/bsdp_option_boot_image_list.go
@@ -37,12 +37,11 @@ func (o *OptBootImageList) Code() dhcpv4.OptionCode {
 
 // ToBytes returns a serialized stream of bytes for this option.
 func (o *OptBootImageList) ToBytes() []byte {
-	bs := make([]byte, 0, 2+o.Length())
-	bs = append(bs, []byte{byte(o.Code()), byte(o.Length())}...)
+	buf := uio.NewBigEndianBuffer(nil)
 	for _, image := range o.Images {
-		bs = append(bs, image.ToBytes()...)
+		image.Marshal(buf)
 	}
-	return bs
+	return buf.Data()
 }
 
 // String returns a human-readable string for this option.
diff --git a/dhcpv4/bsdp/bsdp_option_boot_image_list_test.go b/dhcpv4/bsdp/bsdp_option_boot_image_list_test.go
index 0819d64..8e9c27f 100644
--- a/dhcpv4/bsdp/bsdp_option_boot_image_list_test.go
+++ b/dhcpv4/bsdp/bsdp_option_boot_image_list_test.go
@@ -29,8 +29,6 @@ func TestOptBootImageListInterfaceMethods(t *testing.T) {
 	require.Equal(t, OptionBootImageList, o.Code(), "Code")
 	require.Equal(t, 22, o.Length(), "Length")
 	expectedBytes := []byte{
-		9,  // code
-		22, // length
 		// boot image 1
 		0x1, 0x0, 0x03, 0xe9, // ID
 		6, // name length
diff --git a/dhcpv4/bsdp/bsdp_option_default_boot_image_id.go b/dhcpv4/bsdp/bsdp_option_default_boot_image_id.go
index 52f7780..d75c883 100644
--- a/dhcpv4/bsdp/bsdp_option_default_boot_image_id.go
+++ b/dhcpv4/bsdp/bsdp_option_default_boot_image_id.go
@@ -33,8 +33,7 @@ func (o *OptDefaultBootImageID) Code() dhcpv4.OptionCode {
 
 // ToBytes returns a serialized stream of bytes for this option.
 func (o *OptDefaultBootImageID) ToBytes() []byte {
-	serializedID := o.ID.ToBytes()
-	return append([]byte{byte(o.Code()), byte(len(serializedID))}, serializedID...)
+	return uio.ToBigEndian(o.ID)
 }
 
 // String returns a human-readable string for this option.
diff --git a/dhcpv4/bsdp/bsdp_option_default_boot_image_id_test.go b/dhcpv4/bsdp/bsdp_option_default_boot_image_id_test.go
index ad29c30..eb63457 100644
--- a/dhcpv4/bsdp/bsdp_option_default_boot_image_id_test.go
+++ b/dhcpv4/bsdp/bsdp_option_default_boot_image_id_test.go
@@ -4,6 +4,7 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/require"
+	"github.com/u-root/u-root/pkg/uio"
 )
 
 func TestOptDefaultBootImageIDInterfaceMethods(t *testing.T) {
@@ -11,13 +12,12 @@ func TestOptDefaultBootImageIDInterfaceMethods(t *testing.T) {
 	o := OptDefaultBootImageID{b}
 	require.Equal(t, OptionDefaultBootImageID, o.Code(), "Code")
 	require.Equal(t, 4, o.Length(), "Length")
-	expectedBytes := []byte{byte(OptionDefaultBootImageID), 4}
-	require.Equal(t, append(expectedBytes, b.ToBytes()...), o.ToBytes(), "ToBytes")
+	require.Equal(t, uio.ToBigEndian(b), o.ToBytes(), "ToBytes")
 }
 
 func TestParseOptDefaultBootImageID(t *testing.T) {
 	b := BootImageID{IsInstall: true, ImageType: BootImageTypeMacOSX, Index: 1001}
-	o, err := ParseOptDefaultBootImageID(b.ToBytes())
+	o, err := ParseOptDefaultBootImageID(uio.ToBigEndian(b))
 	require.NoError(t, err)
 	require.Equal(t, &OptDefaultBootImageID{b}, o)
 
diff --git a/dhcpv4/bsdp/bsdp_option_generic.go b/dhcpv4/bsdp/bsdp_option_generic.go
index 6702e9c..cfcffb8 100644
--- a/dhcpv4/bsdp/bsdp_option_generic.go
+++ b/dhcpv4/bsdp/bsdp_option_generic.go
@@ -27,7 +27,7 @@ func (o OptGeneric) Code() dhcpv4.OptionCode {
 
 // ToBytes returns a serialized generic option as a slice of bytes.
 func (o OptGeneric) ToBytes() []byte {
-	return append([]byte{byte(o.Code()), byte(o.Length())}, o.Data...)
+	return o.Data
 }
 
 // String returns a human-readable representation of a generic option.
diff --git a/dhcpv4/bsdp/bsdp_option_generic_test.go b/dhcpv4/bsdp/bsdp_option_generic_test.go
index eae77e1..131af9f 100644
--- a/dhcpv4/bsdp/bsdp_option_generic_test.go
+++ b/dhcpv4/bsdp/bsdp_option_generic_test.go
@@ -36,7 +36,7 @@ func TestOptGenericToBytes(t *testing.T) {
 		Data:       []byte{192, 168, 0, 1},
 	}
 	serialized := o.ToBytes()
-	expected := []byte{3, 4, 192, 168, 0, 1}
+	expected := []byte{192, 168, 0, 1}
 	require.Equal(t, expected, serialized)
 }
 
diff --git a/dhcpv4/bsdp/bsdp_option_machine_name.go b/dhcpv4/bsdp/bsdp_option_machine_name.go
index cffba2e..ef38921 100644
--- a/dhcpv4/bsdp/bsdp_option_machine_name.go
+++ b/dhcpv4/bsdp/bsdp_option_machine_name.go
@@ -25,7 +25,7 @@ func (o *OptMachineName) Code() dhcpv4.OptionCode {
 
 // ToBytes returns a serialized stream of bytes for this option.
 func (o *OptMachineName) ToBytes() []byte {
-	return append([]byte{byte(o.Code()), byte(o.Length())}, []byte(o.Name)...)
+	return []byte(o.Name)
 }
 
 // String returns a human-readable string for this option.
diff --git a/dhcpv4/bsdp/bsdp_option_machine_name_test.go b/dhcpv4/bsdp/bsdp_option_machine_name_test.go
index 712bc49..c06ae7b 100644
--- a/dhcpv4/bsdp/bsdp_option_machine_name_test.go
+++ b/dhcpv4/bsdp/bsdp_option_machine_name_test.go
@@ -10,7 +10,7 @@ func TestOptMachineNameInterfaceMethods(t *testing.T) {
 	o := OptMachineName{"somebox"}
 	require.Equal(t, OptionMachineName, o.Code(), "Code")
 	require.Equal(t, 7, o.Length(), "Length")
-	expectedBytes := []byte{130, 7, 's', 'o', 'm', 'e', 'b', 'o', 'x'}
+	expectedBytes := []byte{'s', 'o', 'm', 'e', 'b', 'o', 'x'}
 	require.Equal(t, expectedBytes, o.ToBytes(), "ToBytes")
 }
 
diff --git a/dhcpv4/bsdp/bsdp_option_message_type.go b/dhcpv4/bsdp/bsdp_option_message_type.go
index 8c3c3d4..c427dd1 100644
--- a/dhcpv4/bsdp/bsdp_option_message_type.go
+++ b/dhcpv4/bsdp/bsdp_option_message_type.go
@@ -53,7 +53,7 @@ func (o *OptMessageType) Code() dhcpv4.OptionCode {
 
 // ToBytes returns a serialized stream of bytes for this option.
 func (o *OptMessageType) ToBytes() []byte {
-	return []byte{byte(o.Code()), 1, byte(o.Type)}
+	return []byte{byte(o.Type)}
 }
 
 // String returns a human-readable string for this option.
diff --git a/dhcpv4/bsdp/bsdp_option_message_type_test.go b/dhcpv4/bsdp/bsdp_option_message_type_test.go
index 41652be..5dcda6c 100644
--- a/dhcpv4/bsdp/bsdp_option_message_type_test.go
+++ b/dhcpv4/bsdp/bsdp_option_message_type_test.go
@@ -10,7 +10,7 @@ func TestOptMessageTypeInterfaceMethods(t *testing.T) {
 	o := OptMessageType{MessageTypeList}
 	require.Equal(t, OptionMessageType, o.Code(), "Code")
 	require.Equal(t, 1, o.Length(), "Length")
-	require.Equal(t, []byte{1, 1, 1}, o.ToBytes(), "ToBytes")
+	require.Equal(t, []byte{1}, o.ToBytes(), "ToBytes")
 }
 
 func TestParseOptMessageType(t *testing.T) {
diff --git a/dhcpv4/bsdp/bsdp_option_reply_port.go b/dhcpv4/bsdp/bsdp_option_reply_port.go
index da5e9c4..39277c3 100644
--- a/dhcpv4/bsdp/bsdp_option_reply_port.go
+++ b/dhcpv4/bsdp/bsdp_option_reply_port.go
@@ -1,7 +1,6 @@
 package bsdp
 
 import (
-	"encoding/binary"
 	"fmt"
 
 	"github.com/insomniacslk/dhcp/dhcpv4"
@@ -32,9 +31,9 @@ func (o *OptReplyPort) Code() dhcpv4.OptionCode {
 
 // ToBytes returns a serialized stream of bytes for this option.
 func (o *OptReplyPort) ToBytes() []byte {
-	serialized := make([]byte, 2)
-	binary.BigEndian.PutUint16(serialized, o.Port)
-	return append([]byte{byte(o.Code()), 2}, serialized...)
+	buf := uio.NewBigEndianBuffer(nil)
+	buf.Write16(o.Port)
+	return buf.Data()
 }
 
 // String returns a human-readable string for this option.
diff --git a/dhcpv4/bsdp/bsdp_option_reply_port_test.go b/dhcpv4/bsdp/bsdp_option_reply_port_test.go
index 719bbc8..413c977 100644
--- a/dhcpv4/bsdp/bsdp_option_reply_port_test.go
+++ b/dhcpv4/bsdp/bsdp_option_reply_port_test.go
@@ -10,7 +10,7 @@ func TestOptReplyPortInterfaceMethods(t *testing.T) {
 	o := OptReplyPort{1234}
 	require.Equal(t, OptionReplyPort, o.Code(), "Code")
 	require.Equal(t, 2, o.Length(), "Length")
-	require.Equal(t, []byte{byte(OptionReplyPort), 2, 4, 210}, o.ToBytes(), "ToBytes")
+	require.Equal(t, []byte{4, 210}, o.ToBytes(), "ToBytes")
 }
 
 func TestParseOptReplyPort(t *testing.T) {
diff --git a/dhcpv4/bsdp/bsdp_option_selected_boot_image_id.go b/dhcpv4/bsdp/bsdp_option_selected_boot_image_id.go
index 52b6eab..9079346 100644
--- a/dhcpv4/bsdp/bsdp_option_selected_boot_image_id.go
+++ b/dhcpv4/bsdp/bsdp_option_selected_boot_image_id.go
@@ -33,8 +33,7 @@ func (o *OptSelectedBootImageID) Code() dhcpv4.OptionCode {
 
 // ToBytes returns a serialized stream of bytes for this option.
 func (o *OptSelectedBootImageID) ToBytes() []byte {
-	serializedID := o.ID.ToBytes()
-	return append([]byte{byte(o.Code()), byte(len(serializedID))}, serializedID...)
+	return uio.ToBigEndian(o.ID)
 }
 
 // String returns a human-readable string for this option.
diff --git a/dhcpv4/bsdp/bsdp_option_selected_boot_image_id_test.go b/dhcpv4/bsdp/bsdp_option_selected_boot_image_id_test.go
index a55fd9f..d9bf2df 100644
--- a/dhcpv4/bsdp/bsdp_option_selected_boot_image_id_test.go
+++ b/dhcpv4/bsdp/bsdp_option_selected_boot_image_id_test.go
@@ -4,6 +4,7 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/require"
+	"github.com/u-root/u-root/pkg/uio"
 )
 
 func TestOptSelectedBootImageIDInterfaceMethods(t *testing.T) {
@@ -11,19 +12,17 @@ func TestOptSelectedBootImageIDInterfaceMethods(t *testing.T) {
 	o := OptSelectedBootImageID{b}
 	require.Equal(t, OptionSelectedBootImageID, o.Code(), "Code")
 	require.Equal(t, 4, o.Length(), "Length")
-	expectedBytes := []byte{byte(OptionSelectedBootImageID), 4}
-	require.Equal(t, append(expectedBytes, b.ToBytes()...), o.ToBytes(), "ToBytes")
+	require.Equal(t, uio.ToBigEndian(b), o.ToBytes(), "ToBytes")
 }
 
 func TestParseOptSelectedBootImageID(t *testing.T) {
 	b := BootImageID{IsInstall: true, ImageType: BootImageTypeMacOSX, Index: 1001}
-	data := b.ToBytes()
-	o, err := ParseOptSelectedBootImageID(data)
+	o, err := ParseOptSelectedBootImageID(uio.ToBigEndian(b))
 	require.NoError(t, err)
 	require.Equal(t, &OptSelectedBootImageID{b}, o)
 
 	// Short byte stream
-	data = []byte{}
+	data := []byte{}
 	_, err = ParseOptSelectedBootImageID(data)
 	require.Error(t, err, "should get error from short byte stream")
 
diff --git a/dhcpv4/bsdp/bsdp_option_server_identifier.go b/dhcpv4/bsdp/bsdp_option_server_identifier.go
index 26ec37a..704d4f2 100644
--- a/dhcpv4/bsdp/bsdp_option_server_identifier.go
+++ b/dhcpv4/bsdp/bsdp_option_server_identifier.go
@@ -27,8 +27,7 @@ func (o *OptServerIdentifier) Code() dhcpv4.OptionCode {
 
 // ToBytes returns a serialized stream of bytes for this option.
 func (o *OptServerIdentifier) ToBytes() []byte {
-	ret := []byte{byte(o.Code()), byte(o.Length())}
-	return append(ret, o.ServerID.To4()...)
+	return o.ServerID.To4()
 }
 
 // String returns a human-readable string.
diff --git a/dhcpv4/bsdp/bsdp_option_server_identifier_test.go b/dhcpv4/bsdp/bsdp_option_server_identifier_test.go
index d832c40..8c4555e 100644
--- a/dhcpv4/bsdp/bsdp_option_server_identifier_test.go
+++ b/dhcpv4/bsdp/bsdp_option_server_identifier_test.go
@@ -11,7 +11,7 @@ func TestOptServerIdentifierInterfaceMethods(t *testing.T) {
 	ip := net.IP{192, 168, 0, 1}
 	o := OptServerIdentifier{ServerID: ip}
 	require.Equal(t, OptionServerIdentifier, o.Code(), "Code")
-	expectedBytes := []byte{3, 4, 192, 168, 0, 1}
+	expectedBytes := []byte{192, 168, 0, 1}
 	require.Equal(t, expectedBytes, o.ToBytes(), "ToBytes")
 	require.Equal(t, 4, o.Length(), "Length")
 	require.Equal(t, "BSDP Server Identifier -> 192.168.0.1", o.String(), "String")
diff --git a/dhcpv4/bsdp/bsdp_option_server_priority.go b/dhcpv4/bsdp/bsdp_option_server_priority.go
index 66bfa44..b362f01 100644
--- a/dhcpv4/bsdp/bsdp_option_server_priority.go
+++ b/dhcpv4/bsdp/bsdp_option_server_priority.go
@@ -1,7 +1,6 @@
 package bsdp
 
 import (
-	"encoding/binary"
 	"fmt"
 
 	"github.com/insomniacslk/dhcp/dhcpv4"
@@ -27,9 +26,9 @@ func (o *OptServerPriority) Code() dhcpv4.OptionCode {
 
 // ToBytes returns a serialized stream of bytes for this option.
 func (o *OptServerPriority) ToBytes() []byte {
-	serialized := make([]byte, 2)
-	binary.BigEndian.PutUint16(serialized, uint16(o.Priority))
-	return append([]byte{byte(o.Code()), byte(o.Length())}, serialized...)
+	buf := uio.NewBigEndianBuffer(nil)
+	buf.Write16(o.Priority)
+	return buf.Data()
 }
 
 // String returns a human-readable string.
diff --git a/dhcpv4/bsdp/bsdp_option_server_priority_test.go b/dhcpv4/bsdp/bsdp_option_server_priority_test.go
index cbcef1d..91a21b6 100644
--- a/dhcpv4/bsdp/bsdp_option_server_priority_test.go
+++ b/dhcpv4/bsdp/bsdp_option_server_priority_test.go
@@ -9,7 +9,7 @@ import (
 func TestOptServerPriorityInterfaceMethods(t *testing.T) {
 	o := OptServerPriority{Priority: 100}
 	require.Equal(t, OptionServerPriority, o.Code(), "Code")
-	require.Equal(t, []byte{4, 2, 0, 100}, o.ToBytes(), "ToBytes")
+	require.Equal(t, []byte{0, 100}, o.ToBytes(), "ToBytes")
 	require.Equal(t, 2, o.Length(), "Length")
 	require.Equal(t, "BSDP Server Priority -> 100", o.String(), "String")
 }
diff --git a/dhcpv4/bsdp/bsdp_option_version.go b/dhcpv4/bsdp/bsdp_option_version.go
index 38158d7..9314cbe 100644
--- a/dhcpv4/bsdp/bsdp_option_version.go
+++ b/dhcpv4/bsdp/bsdp_option_version.go
@@ -34,7 +34,7 @@ func (o *OptVersion) Code() dhcpv4.OptionCode {
 
 // ToBytes returns a serialized stream of bytes for this option.
 func (o *OptVersion) ToBytes() []byte {
-	return append([]byte{byte(o.Code()), 2}, o.Version...)
+	return o.Version
 }
 
 // String returns a human-readable string for this option.
diff --git a/dhcpv4/bsdp/bsdp_option_version_test.go b/dhcpv4/bsdp/bsdp_option_version_test.go
index d28f243..a74ea0e 100644
--- a/dhcpv4/bsdp/bsdp_option_version_test.go
+++ b/dhcpv4/bsdp/bsdp_option_version_test.go
@@ -10,7 +10,7 @@ func TestOptVersionInterfaceMethods(t *testing.T) {
 	o := OptVersion{Version1_1}
 	require.Equal(t, OptionVersion, o.Code(), "Code")
 	require.Equal(t, 2, o.Length(), "Length")
-	require.Equal(t, []byte{2, 2, 1, 1}, o.ToBytes(), "ToBytes")
+	require.Equal(t, []byte{1, 1}, o.ToBytes(), "ToBytes")
 }
 
 func TestParseOptVersion(t *testing.T) {
diff --git a/dhcpv4/bsdp/option_vendor_specific_information.go b/dhcpv4/bsdp/option_vendor_specific_information.go
index 4219e40..2207059 100644
--- a/dhcpv4/bsdp/option_vendor_specific_information.go
+++ b/dhcpv4/bsdp/option_vendor_specific_information.go
@@ -4,6 +4,7 @@ import (
 	"strings"
 
 	"github.com/insomniacslk/dhcp/dhcpv4"
+	"github.com/u-root/u-root/pkg/uio"
 )
 
 // OptVendorSpecificInformation encapsulates the BSDP-specific options used for
@@ -64,13 +65,7 @@ func (o *OptVendorSpecificInformation) Code() dhcpv4.OptionCode {
 
 // ToBytes returns a serialized stream of bytes for this option.
 func (o *OptVendorSpecificInformation) ToBytes() []byte {
-	bs := []byte{byte(o.Code()), byte(o.Length())}
-
-	// Append data section
-	for _, opt := range o.Options {
-		bs = append(bs, opt.ToBytes()...)
-	}
-	return bs
+	return uio.ToBigEndian(o.Options)
 }
 
 // String returns a human-readable string for this option.
diff --git a/dhcpv4/bsdp/option_vendor_specific_information_test.go b/dhcpv4/bsdp/option_vendor_specific_information_test.go
index 689797b..e62589e 100644
--- a/dhcpv4/bsdp/option_vendor_specific_information_test.go
+++ b/dhcpv4/bsdp/option_vendor_specific_information_test.go
@@ -15,8 +15,6 @@ func TestOptVendorSpecificInformationInterfaceMethods(t *testing.T) {
 	require.Equal(t, 2+messageTypeOpt.Length()+2+versionOpt.Length(), o.Length(), "Length")
 
 	expectedBytes := []byte{
-		43,      // code
-		7,       // length
 		1, 1, 1, // List option
 		2, 2, 1, 1, // Version option
 	}