6 files changed, 17 insertions, 126 deletions

diff --git a/dhcpv4/option_domain_search.go b/dhcpv4/option_domain_search.go
index b845b59..5ca17a8 100644
--- a/dhcpv4/option_domain_search.go
+++ b/dhcpv4/option_domain_search.go
@@ -5,6 +5,8 @@ package dhcpv4
 
 import (
 	"fmt"
+
+	"github.com/insomniacslk/dhcp/dnscompress"
 )
 
 // OptDomainSearch represents an option encapsulating a domain search list.
@@ -20,7 +22,7 @@ func (op *OptDomainSearch) Code() OptionCode {
 // 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, labelsToBytes(op.DomainSearch)...)
+	buf = append(buf, dnscompress.LabelsToBytes(op.DomainSearch)...)
 	return buf
 }
 
@@ -53,7 +55,7 @@ func ParseOptDomainSearch(data []byte) (*OptDomainSearch, error) {
 	if len(data) < 2+length {
 		return nil, ErrShortByteStream
 	}
-	domainSearch, err := labelsFromBytes(data[2:length+2])
+	domainSearch, err := dnscompress.LabelsFromBytes(data[2:length+2])
 	if err != nil {
 		return nil, err
 	}
diff --git a/dhcpv4/option_rfc1035label.go b/dhcpv4/option_rfc1035label.go
deleted file mode 100644
index d0972ed..0000000
--- a/dhcpv4/option_rfc1035label.go
+++ /dev/null
@@ -1,53 +0,0 @@
-package dhcpv4
-
-import (
-	"fmt"
-	"strings"
-)
-
-func labelsFromBytes(buf []byte) ([]string, error) {
-	var (
-		pos     = 0
-		domains = make([]string, 0)
-		label   = ""
-	)
-	for {
-		if pos >= len(buf) {
-			return domains, nil
-		}
-		length := int(buf[pos])
-		pos++
-		if length == 0 {
-			domains = append(domains, label)
-			label = ""
-		}
-		if len(buf)-pos < length {
-			return nil, fmt.Errorf("DomainNamesFromBytes: invalid short label length")
-		}
-		if label != "" {
-			label += "."
-		}
-		label += string(buf[pos : pos+length])
-		pos += length
-	}
-}
-
-func labelToBytes(label string) []byte {
-	var encodedLabel []byte
-	if len(label) == 0 {
-		return []byte{0}
-	}
-	for _, part := range strings.Split(label, ".") {
-		encodedLabel = append(encodedLabel, byte(len(part)))
-		encodedLabel = append(encodedLabel, []byte(part)...)
-	}
-	return append(encodedLabel, 0)
-}
-
-func labelsToBytes(labels []string) []byte {
-	var encodedLabels []byte
-	for _, label := range labels {
-		encodedLabels = append(encodedLabels, labelToBytes(label)...)
-	}
-	return encodedLabels
-}
diff --git a/dhcpv4/option_rfc1035label_test.go b/dhcpv4/option_rfc1035label_test.go
deleted file mode 100644
index cd8189a..0000000
--- a/dhcpv4/option_rfc1035label_test.go
+++ /dev/null
@@ -1,66 +0,0 @@
-package dhcpv4
-
-import (
-	"bytes"
-	"testing"
-)
-
-func TestLabelsFromBytes(t *testing.T) {
-	labels, err := labelsFromBytes([]byte{
-		0x9, 's', 'l', 'a', 'c', 'k', 'w', 'a', 'r', 'e',
-		0x2, 'i', 't',
-		0x0,
-	})
-	if err != nil {
-		t.Fatal(err)
-	}
-	if len(labels) != 1 {
-		t.Fatalf("Invalid labels length. Expected: 1, got: %v", len(labels))
-	}
-	if labels[0] != "slackware.it" {
-		t.Fatalf("Invalid label. Expected: %v, got: %v'", "slackware.it", labels[0])
-	}
-}
-
-func TestLabelsFromBytesZeroLength(t *testing.T) {
-	labels, err := labelsFromBytes([]byte{})
-	if err != nil {
-		t.Fatal(err)
-	}
-	if len(labels) != 0 {
-		t.Fatalf("Invalid labels length. Expected: 0, got: %v", len(labels))
-	}
-}
-
-func TestLabelsFromBytesInvalidLength(t *testing.T) {
-	labels, err := labelsFromBytes([]byte{0x3, 0xaa, 0xbb}) // short length
-	if err == nil {
-		t.Fatal("Expected error, got nil")
-	}
-	if len(labels) != 0 {
-		t.Fatalf("Invalid labels length. Expected: 0, got: %v", len(labels))
-	}
-	if labels != nil {
-		t.Fatalf("Invalid label. Expected nil, got %v", labels)
-	}
-}
-
-func TestLabelToBytes(t *testing.T) {
-	encodedLabel := labelToBytes("slackware.it")
-	expected := []byte{
-		0x9, 's', 'l', 'a', 'c', 'k', 'w', 'a', 'r', 'e',
-		0x2, 'i', 't',
-		0x0,
-	}
-	if !bytes.Equal(encodedLabel, expected) {
-		t.Fatalf("Invalid label. Expected: %v, got: %v", expected, encodedLabel)
-	}
-}
-
-func TestLabelToBytesZeroLength(t *testing.T) {
-	encodedLabel := labelToBytes("")
-	expected := []byte{0}
-	if !bytes.Equal(encodedLabel, expected) {
-		t.Fatalf("Invalid label. Expected: %v, got: %v", expected, encodedLabel)
-	}
-}
diff --git a/dhcpv6/option_domainsearchlist.go b/dhcpv6/option_domainsearchlist.go
index 402c68e..cc56ee0 100644
--- a/dhcpv6/option_domainsearchlist.go
+++ b/dhcpv6/option_domainsearchlist.go
@@ -6,6 +6,8 @@ package dhcpv6
 import (
 	"encoding/binary"
 	"fmt"
+
+	"github.com/insomniacslk/dhcp/dnscompress"
 )
 
 // OptDomainSearchList list implements a DOMAIN_SEARCH_LIST option
@@ -21,7 +23,7 @@ func (op *OptDomainSearchList) ToBytes() []byte {
 	buf := make([]byte, 4)
 	binary.BigEndian.PutUint16(buf[0:2], uint16(DOMAIN_SEARCH_LIST))
 	binary.BigEndian.PutUint16(buf[2:4], uint16(op.Length()))
-	buf = append(buf, LabelsToBytes(op.DomainSearchList)...)
+	buf = append(buf, dnscompress.LabelsToBytes(op.DomainSearchList)...)
 	return buf
 }
 
@@ -42,7 +44,7 @@ func (op *OptDomainSearchList) String() string {
 func ParseOptDomainSearchList(data []byte) (*OptDomainSearchList, error) {
 	opt := OptDomainSearchList{}
 	var err error
-	opt.DomainSearchList, err = LabelsFromBytes(data)
+	opt.DomainSearchList, err = dnscompress.LabelsFromBytes(data)
 	if err != nil {
 		return nil, err
 	}
diff --git a/dhcpv6/option_rfc1035label.go b/dnscompress/label.go
index 06870b5..3d84708 100644
--- a/dhcpv6/option_rfc1035label.go
+++ b/dnscompress/label.go
@@ -1,10 +1,14 @@
-package dhcpv6
+package dnscompress
 
 import (
 	"fmt"
 	"strings"
 )
 
+// This implements the compression from RFC 1035, section 4.1.4
+// https://tools.ietf.org/html/rfc1035
+
+// LabelsFromBytes decodes a serialized stream and returns a list of labels
 func LabelsFromBytes(buf []byte) ([]string, error) {
 	var (
 		pos     = 0
@@ -30,9 +34,9 @@ func LabelsFromBytes(buf []byte) ([]string, error) {
 		label += string(buf[pos : pos+length])
 		pos += length
 	}
-	return domains, nil
 }
 
+// LabelToBytes encodes a label and returns a serialized stream of bytes
 func LabelToBytes(label string) []byte {
 	var encodedLabel []byte
 	if len(label) == 0 {
@@ -45,6 +49,8 @@ func LabelToBytes(label string) []byte {
 	return append(encodedLabel, 0)
 }
 
+// LabelsToBytes encodes a list of labels and returns a serialized stream of
+// bytes
 func LabelsToBytes(labels []string) []byte {
 	var encodedLabels []byte
 	for _, label := range labels {
diff --git a/dhcpv6/option_rfc1035label_test.go b/dnscompress/label_test.go
index f99c209..af8e405 100644
--- a/dhcpv6/option_rfc1035label_test.go
+++ b/dnscompress/label_test.go
@@ -1,4 +1,4 @@
-package dhcpv6
+package dnscompress
 
 import (
 	"bytes"