Vendor class: new Getters & tests for Getters, FromBytes, ToBytes

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

3 files changed, 103 insertions, 62 deletions

diff --git a/dhcpv6/dhcpv6message.go b/dhcpv6/dhcpv6message.go
index 72332c5..9bb83bb 100644
--- a/dhcpv6/dhcpv6message.go
+++ b/dhcpv6/dhcpv6message.go
@@ -211,6 +211,33 @@ func (mo MessageOptions) UserClasses() [][]byte {
 	return nil
 }
 
+// VendorClasses returns the all vendor class options.
+func (mo MessageOptions) VendorClasses() []*OptVendorClass {
+	opt := mo.Options.Get(OptionVendorClass)
+	if opt == nil {
+		return nil
+	}
+	var vo []*OptVendorClass
+	for _, o := range opt {
+		if t, ok := o.(*OptVendorClass); ok {
+			vo = append(vo, t)
+		}
+	}
+	return vo
+}
+
+// VendorClass returns the vendor class options matching the given enterprise
+// number.
+func (mo MessageOptions) VendorClass(enterpriseNumber uint32) [][]byte {
+	vo := mo.VendorClasses()
+	for _, v := range vo {
+		if v.EnterpriseNumber == enterpriseNumber {
+			return v.Data
+		}
+	}
+	return nil
+}
+
 // VendorOpts returns the all vendor-specific options.
 //
 // RFC 8415 Section 21.17:
diff --git a/dhcpv6/option_vendorclass.go b/dhcpv6/option_vendorclass.go
index 954dbd0..f85795e 100644
--- a/dhcpv6/option_vendorclass.go
+++ b/dhcpv6/option_vendorclass.go
@@ -1,7 +1,6 @@
 package dhcpv6
 
 import (
-	"errors"
 	"fmt"
 	"strings"
 
@@ -49,8 +48,8 @@ func (op *OptVendorClass) FromBytes(data []byte) error {
 		len := buf.Read16()
 		op.Data = append(op.Data, buf.CopyN(int(len)))
 	}
-	if len(op.Data) < 1 {
-		return errors.New("ParseOptVendorClass: at least one vendor class data is required")
+	if len(op.Data) == 0 {
+		return fmt.Errorf("%w: vendor class data should not be empty", uio.ErrBufferTooShort)
 	}
 	return buf.FinError()
 }
diff --git a/dhcpv6/option_vendorclass_test.go b/dhcpv6/option_vendorclass_test.go
index c691176..5fbc0e6 100644
--- a/dhcpv6/option_vendorclass_test.go
+++ b/dhcpv6/option_vendorclass_test.go
@@ -1,73 +1,88 @@
 package dhcpv6
 
 import (
+	"errors"
+	"fmt"
+	"reflect"
 	"testing"
 
+	"github.com/google/go-cmp/cmp"
 	"github.com/stretchr/testify/require"
+	"github.com/u-root/uio/uio"
 )
 
-func TestParseOptVendorClass(t *testing.T) {
-	data := []byte{
-		0xaa, 0xbb, 0xcc, 0xdd, // EnterpriseNumber
-		0, 10, 'H', 'T', 'T', 'P', 'C', 'l', 'i', 'e', 'n', 't',
-		0, 4, 't', 'e', 's', 't',
-	}
-	var opt OptVendorClass
-	err := opt.FromBytes(data)
-	require.NoError(t, err)
-	require.Equal(t, OptionVendorClass, opt.Code())
-	require.Equal(t, 2, len(opt.Data))
-	require.Equal(t, uint32(0xaabbccdd), opt.EnterpriseNumber)
-	require.Equal(t, []byte("HTTPClient"), opt.Data[0])
-	require.Equal(t, []byte("test"), opt.Data[1])
-}
-
-func TestOptVendorClassToBytes(t *testing.T) {
-	opt := OptVendorClass{
-		EnterpriseNumber: uint32(0xaabbccdd),
-		Data: [][]byte{
-			[]byte("HTTPClient"),
-			[]byte("test"),
+func TestVendorClassParseAndGetter(t *testing.T) {
+	for i, tt := range []struct {
+		buf  []byte
+		err  error
+		want []*OptVendorClass
+	}{
+		{
+			buf: []byte{
+				0, 16, // Vendor Class
+				0, 14, // length
+				0, 0, 0, 16,
+				0, 4,
+				'S', 'L', 'A', 'M',
+				0, 2,
+				'h', 'h',
+			},
+			want: []*OptVendorClass{
+				&OptVendorClass{
+					EnterpriseNumber: 16,
+					Data:             [][]byte{[]byte("SLAM"), []byte("hh")},
+				},
+			},
 		},
-	}
-	data := opt.ToBytes()
-	expected := []byte{
-		0xaa, 0xbb, 0xcc, 0xdd, // EnterpriseNumber
-		0, 10, 'H', 'T', 'T', 'P', 'C', 'l', 'i', 'e', 'n', 't',
-		0, 4, 't', 'e', 's', 't',
-	}
-	require.Equal(t, expected, data)
-}
-
-func TestOptVendorClassParseOptVendorClassMalformed(t *testing.T) {
-	buf := []byte{
-		0xaa, 0xbb, // truncated EnterpriseNumber
-	}
-	var opt OptVendorClass
-	err := opt.FromBytes(buf)
-	require.Error(t, err, "ParseOptVendorClass() should error if given truncated EnterpriseNumber")
-
-	buf = []byte{
-		0xaa, 0xbb, 0xcc, 0xdd, // EnterpriseNumber
-	}
-	err = opt.FromBytes(buf)
-	require.Error(t, err, "ParseOptVendorClass() should error if given no vendor classes")
-
-	buf = []byte{
-		0xaa, 0xbb, 0xcc, 0xdd, // EnterpriseNumber
-		0, 9, 'l', 'i', 'n', 'u', 'x', 'b', 'o', 'o', 't',
-		0, 4, 't', 'e',
-	}
-	err = opt.FromBytes(buf)
-	require.Error(t, err, "ParseOptVendorClass() should error if given truncated vendor classes")
+		{
+			buf: []byte{
+				0, 16,
+				0, 0,
+			},
+			err: uio.ErrBufferTooShort,
+		},
+		{
+			buf: []byte{
+				0, 16,
+				0, 4,
+				0, 0, 0, 6,
+			},
+			err: uio.ErrBufferTooShort,
+		},
+		{
+			buf: []byte{0, 16, 0},
+			err: uio.ErrUnreadBytes,
+		},
+	} {
+		t.Run(fmt.Sprintf("%d", i), func(t *testing.T) {
+			var mo MessageOptions
+			if err := mo.FromBytes(tt.buf); !errors.Is(err, tt.err) {
+				t.Errorf("FromBytes = %v, want %v", err, tt.err)
+			}
+			if got := mo.VendorClasses(); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("VendorClass = %v, want %v", got, tt.want)
+			}
+			for _, v := range tt.want {
+				if got := mo.VendorClass(v.EnterpriseNumber); !reflect.DeepEqual(got, v.Data) {
+					t.Errorf("VendorClass(%d) = %v, want %v", v.EnterpriseNumber, got, v.Data)
+				}
+			}
+			if got := mo.VendorClass(100); got != nil {
+				t.Errorf("VendorClass(100) = %v, want nil", got)
+			}
 
-	buf = []byte{
-		0xaa, 0xbb, 0xcc, 0xdd, // EnterpriseNumber
-		0, 9, 'l', 'i', 'n', 'u', 'x', 'b', 'o', 'o', 't',
-		0,
+			if tt.want != nil {
+				var m MessageOptions
+				for _, o := range tt.want {
+					m.Add(o)
+				}
+				got := m.ToBytes()
+				if diff := cmp.Diff(tt.buf, got); diff != "" {
+					t.Errorf("ToBytes mismatch (-want, +got): %s", diff)
+				}
+			}
+		})
 	}
-	err = opt.FromBytes(buf)
-	require.Error(t, err, "ParseOptVendorClass() should error if given a truncated length")
 }
 
 func TestOptVendorClassString(t *testing.T) {