2 files changed, 56 insertions, 4 deletions
diff --git a/dhcpv6/option_iaprefix.go b/dhcpv6/option_iaprefix.go
index b4adacb..57810b1 100644
--- a/dhcpv6/option_iaprefix.go
+++ b/dhcpv6/option_iaprefix.go
@@ -22,7 +22,7 @@ func (op *OptIAPrefix) Code() OptionCode {
 }
 
 func (op *OptIAPrefix) ToBytes() []byte {
-	buf := make([]byte, 25)
+	buf := make([]byte, 12)
 	binary.BigEndian.PutUint16(buf[0:2], uint16(OPTION_IAPREFIX))
 	binary.BigEndian.PutUint16(buf[2:4], uint16(op.Length()))
 	binary.BigEndian.PutUint32(buf[4:8], op.preferredLifetime)
@@ -91,8 +91,8 @@ func ParseOptIAPrefix(data []byte) (*OptIAPrefix, error) {
 	}
 	opt.preferredLifetime = binary.BigEndian.Uint32(data[:4])
 	opt.validLifetime = binary.BigEndian.Uint32(data[4:8])
-	opt.prefixLength = data[9]
-	copy(opt.ipv6Prefix[:], data[9:17])
-	copy(opt.options, data[17:])
+	opt.prefixLength = data[8]
+	copy(opt.ipv6Prefix[:], data[9:25])
+	copy(opt.options, data[25:])
 	return &opt, nil
 }
diff --git a/dhcpv6/option_iaprefix_test.go b/dhcpv6/option_iaprefix_test.go
new file mode 100644
index 0000000..caabc75
--- /dev/null
+++ b/dhcpv6/option_iaprefix_test.go
@@ -0,0 +1,52 @@
+package dhcpv6
+
+import (
+	"bytes"
+	"net"
+	"testing"
+)
+
+func TestOptIAPrefix(t *testing.T) {
+	buf := []byte{
+		0xaa, 0xbb, 0xcc, 0xdd,                         // preferredLifetime
+		0xee, 0xff, 0x00, 0x11,                         // validLifetime
+		36,                                             // prefixLength
+		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, // ipv6Prefix
+	}
+	opt, err := ParseOptIAPrefix(buf)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if pl := opt.PreferredLifetime(); pl != 0xaabbccdd {
+		t.Fatalf("Invalid Preferred Lifetime. Expected 0xaabbccdd, got %v", pl)
+	}
+	if vl := opt.ValidLifetime(); vl != 0xeeff0011 {
+		t.Fatalf("Invalid Valid Lifetime. Expected 0xeeff0011, got %v", vl)
+	}
+	if pr := opt.PrefixLength(); pr != 36 {
+		t.Fatalf("Invalid Prefix Length. Expected 36, got %v", pr)
+	}
+	if ip := opt.IPv6Prefix(); !bytes.Equal(ip, net.IPv6loopback) {
+		t.Fatalf("Invalid Prefix Length. Expected %v, got %v", net.IPv6loopback, ip)
+	}
+}
+
+func TestOptIAPrefixToBytes(t *testing.T) {
+	buf := []byte{
+		0xaa, 0xbb, 0xcc, 0xdd,                         // preferredLifetime
+		0xee, 0xff, 0x00, 0x11,                         // validLifetime
+		36,                                             // prefixLength
+		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // ipv6Prefix
+	}
+	expected := []byte{00, 26, 00, byte(len(buf))}
+	expected = append(expected, buf...)
+	opt := OptIAPrefix{
+		preferredLifetime: 0xaabbccdd,
+		validLifetime: 0xeeff0011,
+		prefixLength: 36,
+	}
+	toBytes := opt.ToBytes()
+	if !bytes.Equal(toBytes, expected) {
+		t.Fatalf("Invalid ToBytes result. Expected %v, got %v", expected, toBytes)
+	}
+}