fixed typo, removed boilerplate code

protocols/bgp/packet/path_attributes.go

@@ -180,41 +180,15 @@ func (pa *PathAttribute) decodeASPath(buf *bytes.Buffer) error {
 }
 
 func (pa *PathAttribute) decodeNextHop(buf *bytes.Buffer) error {
-	addr := [4]byte{}
-
-	p := uint16(0)
-	n, err := buf.Read(addr[:])
-	if err != nil {
-		return err
-	}
-	if n != 4 {
-		return fmt.Errorf("Unable to read next hop: buf.Read read %d bytes", n)
-	}
-
-	pa.Value = fourBytesToUint32(addr)
-	p += 4
-
-	return dumpNBytes(buf, pa.Length-p)
+	return pa.decodeUint32(buf, "next hop")
 }
 
 func (pa *PathAttribute) decodeMED(buf *bytes.Buffer) error {
-	med, err := pa.decodeUint32(buf)
-	if err != nil {
-		return fmt.Errorf("Unable to decode MED: %v", err)
-	}
-
-	pa.Value = uint32(med)
-	return nil
+	return pa.decodeUint32(buf, "MED")
 }
 
 func (pa *PathAttribute) decodeLocalPref(buf *bytes.Buffer) error {
-	lpref, err := pa.decodeUint32(buf)
-	if err != nil {
-		return fmt.Errorf("Unable to decode local pref: %v", err)
-	}
-
-	pa.Value = uint32(lpref)
-	return nil
+	return pa.decodeUint32(buf, "local pref")
 }
 
 func (pa *PathAttribute) decodeAggregator(buf *bytes.Buffer) error {
@@ -273,19 +247,19 @@ func (pa *PathAttribute) decodeLargeCommunities(buf *bytes.Buffer) error {
 	for i := uint16(0); i < count; i++ {
 		com := LargeCommunity{}
 
-		v, err := read4BytesAsUin32(buf)
+		v, err := read4BytesAsUint32(buf)
 		if err != nil {
 			return err
 		}
 		com.GlobalAdministrator = v
 
-		v, err = read4BytesAsUin32(buf)
+		v, err = read4BytesAsUint32(buf)
 		if err != nil {
 			return err
 		}
 		com.DataPart1 = v
 
-		v, err = read4BytesAsUin32(buf)
+		v, err = read4BytesAsUint32(buf)
 		if err != nil {
 			return err
 		}
@@ -301,22 +275,27 @@ func (pa *PathAttribute) decodeLargeCommunities(buf *bytes.Buffer) error {
 }
 
 func (pa *PathAttribute) decodeAS4Path(buf *bytes.Buffer) error {
-	as4Path, err := pa.decodeUint32(buf)
+	return pa.decodeUint32(buf, "AS4Path")
+}
+
+func (pa *PathAttribute) decodeAS4Aggregator(buf *bytes.Buffer) error {
+	return pa.decodeUint32(buf, "AS4Aggregator")
+}
+
+func (pa *PathAttribute) decodeUint32(buf *bytes.Buffer, attrName string) error {
+	v, err := read4BytesAsUint32(buf)
 	if err != nil {
-		return fmt.Errorf("Unable to decode AS4Path: %v", err)
+		return fmt.Errorf("Unable to decode %s: %v", attrName, err)
 	}
 
-	pa.Value = as4Path
-	return nil
-}
+	pa.Value = v
 
-func (pa *PathAttribute) decodeAS4Aggregator(buf *bytes.Buffer) error {
-	as4Aggregator, err := pa.decodeUint32(buf)
+	p := uint16(4)
+	err = dumpNBytes(buf, pa.Length-p)
 	if err != nil {
-		return fmt.Errorf("Unable to decode AS4Aggregator: %v", err)
+		return fmt.Errorf("dumpNBytes failed: %v", err)
 	}
 
-	pa.Value = as4Aggregator
 	return nil
 }
 
@@ -340,24 +319,6 @@ func (pa *PathAttribute) setLength(buf *bytes.Buffer) (int, error) {
 	return bytesRead, nil
 }
 
-func (pa *PathAttribute) decodeUint32(buf *bytes.Buffer) (uint32, error) {
-	var v uint32
-
-	p := uint16(0)
-	err := decode(buf, []interface{}{&v})
-	if err != nil {
-		return 0, err
-	}
-
-	p += 4
-	err = dumpNBytes(buf, pa.Length-p)
-	if err != nil {
-		return 0, fmt.Errorf("dumpNBytes failed: %v", err)
-	}
-
-	return v, nil
-}
-
 func (pa *PathAttribute) ASPathString() (ret string) {
 	for _, p := range pa.Value.(ASPath) {
 		if p.Type == ASSet {
@@ -670,14 +631,14 @@ func fourBytesToUint32(address [4]byte) uint32 {
 	return uint32(address[0])<<24 + uint32(address[1])<<16 + uint32(address[2])<<8 + uint32(address[3])
 }
 
-func read4BytesAsUin32(buf *bytes.Buffer) (uint32, error) {
+func read4BytesAsUint32(buf *bytes.Buffer) (uint32, error) {
 	b := [4]byte{}
 	n, err := buf.Read(b[:])
 	if err != nil {
 		return 0, err
 	}
 	if n != 4 {
-		return 0, fmt.Errorf("Unable to read as uint32: buf.Read read %d bytes", n)
+		return 0, fmt.Errorf("Unable to read as uint32. Expected 4 bytes but got only %d", n)
 	}
 
 	return fourBytesToUint32(b), nil

protocols/bgp/packet/path_attributes_test.go

@@ -724,7 +724,7 @@ func TestSetLength(t *testing.T) {
 	}
 }
 
-func TestDecodeUint32(t *testing.T) {
+func TestRead4BytesAsUint32(t *testing.T) {
 	tests := []struct {
 		name           string
 		input          []byte
@@ -763,7 +763,7 @@ func TestDecodeUint32(t *testing.T) {
 		pa := &PathAttribute{
 			Length: l,
 		}
-		res, err := pa.decodeUint32(bytes.NewBuffer(test.input))
+		err := pa.decodeUint32(bytes.NewBuffer(test.input), "test")
 
 		if test.wantFail {
 			if err != nil {
@@ -778,7 +778,7 @@ func TestDecodeUint32(t *testing.T) {
 			continue
 		}
 
-		assert.Equal(t, test.expected, res)
+		assert.Equal(t, test.expected, pa.Value)
 	}
 }