PartyAddress refactoring and some cleanup

Author: wmnsk

examples/client/simple-client.go

@@ -72,29 +72,43 @@ func main() {
 		log.Fatal(err)
 	}
 
-	cdPA, err := utils.StrToSwappedBytes("1234567890123456", "0")
+	cd, err := utils.EncodeBCD("1234567890123456")
 	if err != nil {
 		log.Fatal(err)
 	}
-	cgPA, err := utils.StrToSwappedBytes("9876543210", "0")
+	cg, err := utils.EncodeBCD("9876543210")
 	if err != nil {
 		log.Fatal(err)
 	}
 
+	gti := params.GTITTNPESNAI
+	ai := params.NewAddressIndicator(false, true, false, gti)
+	cdPA := params.NewPartyAddressTyped(
+		ai, 0, 6, params.NewGlobalTitle(
+			gti,
+			params.TranslationType(0),
+			params.NPISDNTelephony,
+			params.ESBCDOdd,
+			params.NAIInternationalNumber,
+			cd,
+		),
+	)
+	cgPA := params.NewPartyAddressTyped(
+		ai, 0, 7, params.NewGlobalTitle(
+			gti,
+			params.TranslationType(1),
+			params.NPISDNMobile,
+			params.ESBCDOdd,
+			params.NAIInternationalNumber,
+			cg,
+		),
+	)
 	// create UDT message with CdPA, CgPA and payload
 	udt, err := sccp.NewUDT(
 		1,    // Protocol Class
 		true, // Message handling
-		params.NewPartyAddress( // CalledPartyAddress: 1234567890123456
-			0x12, 0, 6, 0x00, // Indicator, SPC, SSN, TT
-			0x01, 0x01, 0x04, // NP, ES, NAI
-			cdPA, // GlobalTitleInformation
-		),
-		params.NewPartyAddress( // CallingPartyAddress: 9876543210
-			0x12, 0, 7, 0x01, // Indicator, SPC, SSN, TT
-			0x01, 0x02, 0x04, // NP, ES, NAI
-			cgPA, // GlobalTitleInformation
-		),
+		cdPA,
+		cgPA,
 		payload, // payload
 	).MarshalBinary()
 	if err != nil {

header.go

@@ -0,0 +1,230 @@
+package params
+
+import (
+	"fmt"
+	"io"
+)
+
+// GlobalTitle is a GlobalTitle inside the Called/Calling Party Address.
+type GlobalTitle struct {
+	// GTI is included in the Address Indicator which is not a part of
+	// Global Title itself, but necessary to encode/decode it properly.
+	GTI GlobalTitleIndicator
+	TranslationType
+	NumberingPlan
+	EncodingScheme
+	NatureOfAddressIndicator
+	AddressInformation []byte
+}
+
+// GlobalTitleIndicator is a type of Global Title Indicator.
+// See Q.713 3.4.1 for more details.
+type GlobalTitleIndicator uint8
+
+const (
+	GTINAIOnly   GlobalTitleIndicator = 0b0001
+	GTITTOnly    GlobalTitleIndicator = 0b0010
+	GTITTNPES    GlobalTitleIndicator = 0b0011
+	GTITTNPESNAI GlobalTitleIndicator = 0b0100
+)
+
+// NatureOfAddressIndicator is a type of Nature of Address Indicator.
+type NatureOfAddressIndicator uint8
+
+// NatureOfAddressIndicator values.
+const (
+	NAIUnknown                   NatureOfAddressIndicator = 0b00000000
+	NAISubscriberNumber          NatureOfAddressIndicator = 0b00000001
+	_                            NatureOfAddressIndicator = 0b00000010 // Reserved for national use
+	NAINationalSignificantNumber NatureOfAddressIndicator = 0b00000011
+	NAIInternationalNumber       NatureOfAddressIndicator = 0b00000100
+)
+
+// Even returns the NatureOfAddressIndicator with the last bit set to 0.
+func (nai NatureOfAddressIndicator) Even() NatureOfAddressIndicator {
+	return nai & 0b01111111
+}
+
+// Odd returns the NatureOfAddressIndicator with the last bit set to 1.
+func (nai NatureOfAddressIndicator) Odd() NatureOfAddressIndicator {
+	return nai | 0b10000000
+}
+
+// TranslationType is a type of Translation Type.
+type TranslationType uint8
+
+// NumberingPlan is a type of Numbering Plan.
+type NumberingPlan uint8
+
+// NumberingPlan values.
+const (
+	NPUnknown        NumberingPlan = 0b0000
+	NPISDNTelephony  NumberingPlan = 0b0001
+	NPGeneric        NumberingPlan = 0b0010
+	NPData           NumberingPlan = 0b0011
+	NPTelex          NumberingPlan = 0b0100
+	NPMaritimeMobile NumberingPlan = 0b0101
+	NPLandMobile     NumberingPlan = 0b0110
+	NPISDNMobile     NumberingPlan = 0b0111
+	NPPrivate        NumberingPlan = 0b1110
+)
+
+// EncodingScheme is a type of Encoding Scheme.
+type EncodingScheme uint8
+
+// EncodingScheme values.
+const (
+	ESUnknown          EncodingScheme = 0b0000
+	ESBCDOdd           EncodingScheme = 0b0001
+	ESBCDEven          EncodingScheme = 0b0010
+	ESNationalSpecific EncodingScheme = 0b0011
+)
+
+// NewGlobalTitle creates a new GlobalTitle.
+//
+// The first argument is a Global Title Indicator, which is included in the Address Indicator
+// in the parent PartyAddress.
+func NewGlobalTitle(
+	gti GlobalTitleIndicator,
+	tt TranslationType,
+	np NumberingPlan,
+	es EncodingScheme,
+	nai NatureOfAddressIndicator,
+	addr []byte,
+) *GlobalTitle {
+	gt := &GlobalTitle{GTI: gti}
+
+	switch gti {
+	case GTINAIOnly:
+		gt.NatureOfAddressIndicator = nai
+	case GTITTOnly:
+		gt.TranslationType = tt
+	case GTITTNPES:
+		gt.TranslationType = tt
+		gt.NumberingPlan = np
+		gt.EncodingScheme = es
+	case GTITTNPESNAI:
+		gt.TranslationType = tt
+		gt.NumberingPlan = np
+		gt.EncodingScheme = es
+		gt.NatureOfAddressIndicator = nai
+	}
+
+	gt.AddressInformation = addr
+	return gt
+}
+
+// MarshalBinary returns the byte sequence generated from a GlobalTitle.
+func (g *GlobalTitle) MarshalBinary() []byte {
+	b := make([]byte, g.MarshalLen())
+	if err := g.MarshalTo(b); err != nil {
+		panic(err)
+	}
+
+	return b
+}
+
+// MarshalTo puts the byte sequence in the byte array given as b.
+func (g *GlobalTitle) MarshalTo(b []byte) error {
+	if len(b) < g.MarshalLen() {
+		return io.ErrUnexpectedEOF
+	}
+	offset := 0
+	switch g.GTI {
+	case GTINAIOnly:
+		b[offset] = uint8(g.NatureOfAddressIndicator)
+		offset++
+	case GTITTOnly:
+		b[offset] = uint8(g.TranslationType)
+		offset++
+	case GTITTNPES:
+		b[offset] = uint8(g.TranslationType)
+		b[offset+1] = uint8(g.NumberingPlan)<<4 | uint8(g.EncodingScheme)
+		offset += 2
+	case GTITTNPESNAI:
+		b[offset] = uint8(g.TranslationType)
+		b[offset+1] = uint8(g.NumberingPlan)<<4 | uint8(g.EncodingScheme)
+		b[offset+2] = uint8(g.NatureOfAddressIndicator)
+		offset += 3
+	}
+
+	copy(b[offset:g.MarshalLen()], g.AddressInformation)
+	return nil
+}
+
+// ParseGlobalTitle decodes given byte sequence as a GlobalTitle.
+// The given byte sequence should not include the excess bytes for the parent PartyAddress.
+// otherwise, AddressInformation will include them.
+func ParseGlobalTitle(gti GlobalTitleIndicator, b []byte) (*GlobalTitle, error) {
+	g := &GlobalTitle{GTI: gti}
+	if err := g.UnmarshalBinary(b); err != nil {
+		return nil, err
+	}
+
+	return g, nil
+}
+
+// UnmarshalBinary sets the values retrieved from byte sequence in a GlobalTitle.
+// The given byte sequence should not include the excess bytes for the parent PartyAddress.
+// otherwise, AddressInformation will include them.
+func (g *GlobalTitle) UnmarshalBinary(b []byte) error {
+	if len(b) < g.lenByGTI() {
+		return io.ErrUnexpectedEOF
+	}
+
+	offset := 0
+	switch g.GTI {
+	case GTINAIOnly:
+		g.NatureOfAddressIndicator = NatureOfAddressIndicator(b[offset])
+		offset++
+	case GTITTOnly:
+		g.TranslationType = TranslationType(b[offset])
+		offset++
+	case GTITTNPES:
+		g.TranslationType = TranslationType(b[offset])
+		g.NumberingPlan = NumberingPlan(b[offset+1] >> 4)
+		g.EncodingScheme = EncodingScheme(b[offset+1] & 0x0F)
+		offset += 2
+	case GTITTNPESNAI:
+		g.TranslationType = TranslationType(b[offset])
+		g.NumberingPlan = NumberingPlan(b[offset+1] >> 4)
+		g.EncodingScheme = EncodingScheme(b[offset+1] & 0x0F)
+		g.NatureOfAddressIndicator = NatureOfAddressIndicator(b[offset+2])
+		offset += 3
+	}
+
+	g.AddressInformation = b[offset:]
+	return nil
+}
+
+// MarshalLen returns the serial length of a GlobalTitle.
+func (g *GlobalTitle) MarshalLen() int {
+	return g.lenByGTI()
+}
+
+func (g *GlobalTitle) lenByGTI() int {
+	var l int
+	switch g.GTI {
+	case GTINAIOnly:
+		l += 1
+	case GTITTOnly:
+		l += 1
+	case GTITTNPES:
+		l += 2
+	case GTITTNPESNAI:
+		l += 3
+	}
+
+	if g.AddressInformation != nil {
+		l += len(g.AddressInformation)
+	}
+
+	return l
+}
+
+// String returns the GlobalTitle in a human-readable format.
+func (g *GlobalTitle) String() string {
+	return fmt.Sprintf("{GTI: %d, TransationType: %d, NumberingPlan: %d, EncodingScheme: %d, NatureOfAddressIndicator: %d, AddressInformation: %#x}",
+		g.GTI, g.TranslationType, g.NumberingPlan, g.EncodingScheme, g.NatureOfAddressIndicator, g.AddressInformation,
+	)
+}

params/global-title.go

@@ -28,12 +28,19 @@ var testcases = []struct {
 }{
 	{
 		description: "PartyAddress",
-		structured: params.NewPartyAddress(
-			0x12, 0, 6, 0, // GTI, SPC, SSN, TT
-			1, 1, 4, // NP, ES, NAI
-			[]byte{
-				0x21, 0x43, 0x65, 0x87, 0x09,
-			},
+		structured: params.NewPartyAddressTyped(
+			params.NewAddressIndicator(false, true, false, params.GTITTNPESNAI),
+			0, 6, // SPC, SSN
+			params.NewGlobalTitle(
+				params.GTITTNPESNAI,
+				params.TranslationType(0),
+				params.NPISDNTelephony,
+				params.ESBCDOdd,
+				params.NAIInternationalNumber,
+				[]byte{
+					0x21, 0x43, 0x65, 0x87, 0x09,
+				},
+			),
 		),
 		serialized: []byte{
 			0x0a, 0x12, 0x06, 0x00, 0x11, 0x04, 0x21, 0x43, 0x65, 0x87, 0x09,
@@ -48,10 +55,9 @@ var testcases = []struct {
 		},
 	}, {
 		description: "PartyAddress/2-bytes",
-		structured: params.NewPartyAddress(
-			0x42, 0, 6, 0x00, // Indicator, SPC, SSN, TT
-			0x00, 0x00, 0x00, // NP, ES, NAI
-			nil, // GlobalTitleInformation
+		structured: params.NewPartyAddressTyped(
+			params.NewAddressIndicator(false, true, true, params.GlobalTitleIndicator(0)),
+			0, 6, nil, // SPC, SSN, GT
 		),
 		serialized: []byte{
 			0x02, 0x42, 0x06,