Supports marshaling of nested IEs

codec_test.go

@@ -412,6 +412,33 @@ var testcases = []struct {
 		serialized:  []byte{0x48, 0x04, 0xde, 0xad, 0xbe, 0xef},
 		parseFunc:   func(b []byte) (serializable, error) { return tcap.ParseIE(b) },
 	},
+	{
+		description: "IE/UserInformation",
+		structured: func() *tcap.IE {
+			dialoguePDU := tcap.NewIE(0xa0, []byte{0xde, 0xad, 0xbe, 0xef})
+
+			singleAsn1Type := tcap.NewIE(0xa0, []byte{})
+			singleAsn1Type.IE = []*tcap.IE{dialoguePDU}
+
+			directReference := tcap.NewIE(0x06, []byte{04, 00, 00, 01, 01, 01, 01})
+
+			userInfoItem := tcap.NewIE(0x28, []byte{})
+			userInfoItem.IE = []*tcap.IE{directReference, singleAsn1Type}
+
+			userInfo := tcap.NewIE(0xBE, []byte{})
+			userInfo.IE = []*tcap.IE{userInfoItem}
+
+			userInfo.SetLength()
+
+			return userInfo
+		}(),
+		serialized: []byte{
+			0xbe, 0x13, 0x28, 0x11, 0x06, 0x07, 0x04,
+			0x00, 0x00, 0x01, 0x01, 0x01, 0x01, 0xa0,
+			0x06, 0xa0, 0x04, 0xde, 0xad, 0xbe, 0xef,
+		},
+		parseFunc: func(b []byte) (serializable, error) { return tcap.ParseIERecursive(b) },
+	},
 }
 
 func TestCodec(t *testing.T) {

component.go

@@ -369,6 +369,12 @@ func (c *Components) UnmarshalBinary(b []byte) error {
 		}
 		b = b[offset+comp.MarshalLen()-2:]
 	}
+
+	c.SetLength()
+	if b[1] != c.Length {
+		return fmt.Errorf("Decoded Length is not equal to Components Length, got %d, expected %d", c.Length, b[1])
+	}
+
 	return nil
 }
 
@@ -388,6 +394,7 @@ func (c *Component) UnmarshalBinary(b []byte) error {
 	}
 	c.Type = Tag(b[0])
 	c.Length = b[1]
+	expectedLength := b[1]
 
 	var err error
 	var offset = 2
@@ -434,12 +441,16 @@ func (c *Component) UnmarshalBinary(b []byte) error {
 		offset += c.OperationCode.MarshalLen()
 
 		if offset >= len(b) {
+			c.ResultRetres.Value = []byte{}
 			return nil
 		}
 		c.Parameter, err = ParseIERecursive(b[offset:])
 		if err != nil {
 			return err
 		}
+		offset += c.Parameter.MarshalLen()
+		c.ResultRetres.Value = c.ResultRetres.Value[offset:]
+
 	case ReturnError:
 		c.ErrorCode, err = ParseIE(b[offset:])
 		if err != nil {
@@ -460,6 +471,12 @@ func (c *Component) UnmarshalBinary(b []byte) error {
 			return err
 		}
 	}
+
+	c.SetLength()
+	if expectedLength != c.Length {
+		return fmt.Errorf("Decoded Length is not equal to Component Length, got %d, expected %d", c.Length, b[1])
+	}
+
 	return nil
 }
 
@@ -478,14 +495,13 @@ func (c *Component) setParameterFromBytes(b []byte) error {
 			Tag:   NewUniversalConstructorTag(0x10),
 			Value: b,
 		}
-
 		return nil
 	}
 
 	c.Parameter = &IE{
 		// TODO: tag should not be determined here.
 		Tag:   NewUniversalConstructorTag(0x10),
-		Value: b,
+		Value: []byte{}, // If we were able to parse the IEs, do not set value
 		IE:    ies,
 	}
 	return nil

dialogue-pdu.go

@@ -386,7 +386,7 @@ func ParseDialoguePDU(b []byte) (*DialoguePDU, error) {
 }
 
 // UnmarshalBinary sets the values retrieved from byte sequence in an DialoguePDU.
-func (d *DialoguePDU) UnmarshalBinary(b []byte) error {
+func (d *DialoguePDU) UnmarshalBinary(b []byte) (err error) {
 	if len(b) < 4 {
 		return io.ErrUnexpectedEOF
 	}
@@ -396,14 +396,25 @@ func (d *DialoguePDU) UnmarshalBinary(b []byte) error {
 
 	switch d.Type.Code() {
 	case AARQ:
-		return d.parseAARQFromBytes(b)
+		err = d.parseAARQFromBytes(b)
 	case AARE:
-		return d.parseAAREFromBytes(b)
+		err = d.parseAAREFromBytes(b)
 	case ABRT:
-		return d.parseABRTFromBytes(b)
+		err = d.parseABRTFromBytes(b)
 	default:
-		return &InvalidCodeError{Code: d.Type.Code()}
+		err = &InvalidCodeError{Code: d.Type.Code()}
 	}
+
+	if err != nil {
+		return
+	}
+
+	d.SetLength()
+	if b[1] != d.Length {
+		return fmt.Errorf("Decoded Length is not equal to DialoguePDU Length, got %d, expected %d", d.Length, b[1])
+	}
+
+	return nil
 }
 
 func (d *DialoguePDU) parseAARQFromBytes(b []byte) error {

dialogue.go

@@ -194,7 +194,7 @@ func (d *Dialogue) MarshalLen() int {
 		l += field.MarshalLen()
 	}
 	if field := d.DialoguePDU; field != nil {
-		l += field.MarshalLen() + 2 // 2 = singleAsn1Type IE Header
+		l += field.MarshalLen() + 2 // 2 = SingleAsn1Type IE Header
 	}
 
 	return l + len(d.Payload)

ie.go

@@ -116,13 +116,24 @@ func (i *IE) MarshalBinary() ([]byte, error) {
 
 // MarshalTo puts the byte sequence in the byte array given as b.
 func (i *IE) MarshalTo(b []byte) error {
+	var offset = 2
+
 	if len(b) < 2 {
 		return io.ErrUnexpectedEOF
 	}
 
 	b[0] = uint8(i.Tag)
 	b[1] = i.Length
-	copy(b[2:i.MarshalLen()], i.Value)
+
+	offset += copy(b[offset:], i.Value)
+
+	for _, childIE := range i.IE {
+		if err := childIE.MarshalTo(b[offset : offset+childIE.MarshalLen()]); err != nil {
+			return err
+		}
+		offset += childIE.MarshalLen()
+	}
+
 	return nil
 }
 
@@ -167,6 +178,11 @@ func (i *IE) UnmarshalBinary(b []byte) error {
 		return io.ErrUnexpectedEOF
 	}
 	i.Value = b[2 : 2+int(i.Length)]
+
+	i.SetLength()
+	if b[1] != i.Length {
+		return fmt.Errorf("Decoded Length is not equal to IE Length, got %d, expected %d", i.Length, b[1])
+	}
 	return nil
 }
 
@@ -228,7 +244,7 @@ func (i *IE) ParseRecursive(b []byte) error {
 	i.Tag = Tag(b[0])
 	i.Length = b[1]
 	if int(i.Length)+2 > len(b) {
-		return nil
+		return io.ErrUnexpectedEOF
 	}
 	i.Value = b[2 : 2+int(i.Length)]
 
@@ -238,19 +254,29 @@ func (i *IE) ParseRecursive(b []byte) error {
 			return nil
 		}
 		i.IE = append(i.IE, x...)
-	}
 
+		i.Value = b[2+int(i.Length):]
+	}
 	return nil
 }
 
 // MarshalLen returns the serial length of IE.
 func (i *IE) MarshalLen() int {
-	return 2 + len(i.Value)
+	l := 2
+	for _, childIE := range i.IE {
+		l += childIE.MarshalLen()
+	}
+
+	return l + len(i.Value)
 }
 
 // SetLength sets the length in Length field.
 func (i *IE) SetLength() {
-	i.Length = uint8(len(i.Value))
+	for _, childIE := range i.IE {
+		childIE.SetLength()
+	}
+
+	i.Length = uint8(i.MarshalLen() - 2)
 }
 
 // String returns IE in human readable string.

tcap.go

@@ -124,6 +124,7 @@ func (t *TCAP) UnmarshalBinary(b []byte) error {
 	var offset = 0
 
 	t.Transaction, err = ParseTransaction(b[offset:])
+	transactionLength := t.Transaction.Length
 	if err != nil {
 		return err
 	}
@@ -140,16 +141,29 @@ func (t *TCAP) UnmarshalBinary(b []byte) error {
 		if len(t.Dialogue.Payload) == 0 {
 			return nil
 		}
+		// Dialogue is not a Transaction Payload
+		// We have to remove Dialogue from the Payload
+		// Or mashaling an unmarshaled message will write back two times the Dialogue
+		t.Transaction.Payload = t.Transaction.Payload[t.Dialogue.MarshalLen():]
 
 		t.Components, err = ParseComponents(t.Dialogue.Payload)
 		if err != nil {
 			return err
 		}
+
+		// Same as above but Components inside Dialogue Payload
+		t.Dialogue.Payload = t.Dialogue.Payload[t.Components.MarshalLen():]
 	case 0x6c:
 		t.Components, err = ParseComponents(t.Transaction.Payload)
 		if err != nil {
 			return err
 		}
+		t.Transaction.Payload = t.Transaction.Payload[t.Components.MarshalLen():]
+	}
+
+	t.SetLength()
+	if transactionLength != t.Transaction.Length {
+		return fmt.Errorf("Decoded Length is not equal to Transaction Length, got %d, expected %d", t.Transaction.Length, transactionLength)
 	}
 
 	return nil