Merge pull request #240 from wmnsk/v1-uli

[gtpv1] Fix 3-digit MNC handling in ULI
wmnsk · Sep 2, 2023 · dfe8999 · dfe8999
2 parents b58c9a2 + 5beffd4
commit dfe8999
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Showing 2 changed files with 30 additions and 21 deletions.
diff --git a/gtpv1/ie/uli.go b/gtpv1/ie/uli.go
@@ -20,11 +20,7 @@ const (
 
 // NewUserLocationInformationWithCGI creates a new UserLocationInformation IE with LAC.
 func NewUserLocationInformationWithCGI(mcc, mnc string, lac, cgi uint16) *IE {
-	mc, err := utils.StrToSwappedBytes(mcc, "f")
-	if err != nil {
-		return nil
-	}
-	mn, err := utils.StrToSwappedBytes(mnc, "f")
+	plmn, err := utils.EncodePLMN(mcc, mnc)
 	if err != nil {
 		return nil
 	}
@@ -34,8 +30,7 @@ func NewUserLocationInformationWithCGI(mcc, mnc string, lac, cgi uint16) *IE {
 		make([]byte, 8),
 	)
 	uli.Payload[0] = locTypeCGI
-	copy(uli.Payload[1:3], mc)
-	uli.Payload[3] = mn[0]
+	copy(uli.Payload[1:4], plmn)
 	binary.BigEndian.PutUint16(uli.Payload[4:6], lac)
 	binary.BigEndian.PutUint16(uli.Payload[6:8], cgi)
 
@@ -44,11 +39,7 @@ func NewUserLocationInformationWithCGI(mcc, mnc string, lac, cgi uint16) *IE {
 
 // NewUserLocationInformationWithSAI creates a new UserLocationInformation IE with LAC.
 func NewUserLocationInformationWithSAI(mcc, mnc string, lac, sac uint16) *IE {
-	mc, err := utils.StrToSwappedBytes(mcc, "f")
-	if err != nil {
-		return nil
-	}
-	mn, err := utils.StrToSwappedBytes(mnc, "f")
+	plmn, err := utils.EncodePLMN(mcc, mnc)
 	if err != nil {
 		return nil
 	}
@@ -58,8 +49,7 @@ func NewUserLocationInformationWithSAI(mcc, mnc string, lac, sac uint16) *IE {
 		make([]byte, 8),
 	)
 	uli.Payload[0] = locTypeSAI
-	copy(uli.Payload[1:3], mc)
-	uli.Payload[3] = mn[0]
+	copy(uli.Payload[1:4], plmn)
 	binary.BigEndian.PutUint16(uli.Payload[4:6], lac)
 	binary.BigEndian.PutUint16(uli.Payload[6:8], sac)
 
@@ -68,11 +58,7 @@ func NewUserLocationInformationWithSAI(mcc, mnc string, lac, sac uint16) *IE {
 
 // NewUserLocationInformationWithRAI creates a new UserLocationInformation IE with LAC.
 func NewUserLocationInformationWithRAI(mcc, mnc string, lac uint16, rac uint8) *IE {
-	mc, err := utils.StrToSwappedBytes(mcc, "f")
-	if err != nil {
-		return nil
-	}
-	mn, err := utils.StrToSwappedBytes(mnc, "f")
+	plmn, err := utils.EncodePLMN(mcc, mnc)
 	if err != nil {
 		return nil
 	}
@@ -82,8 +68,7 @@ func NewUserLocationInformationWithRAI(mcc, mnc string, lac uint16, rac uint8) *
 		make([]byte, 7),
 	)
 	uli.Payload[0] = locTypeRAI
-	copy(uli.Payload[1:3], mc)
-	uli.Payload[3] = mn[0]
+	copy(uli.Payload[1:4], plmn)
 	binary.BigEndian.PutUint16(uli.Payload[4:6], lac)
 	uli.Payload[6] = rac
 

diff --git a/gtpv1/ie/uli_test.go b/gtpv1/ie/uli_test.go
@@ -32,6 +32,30 @@ func TestUserLocationInformationWithCGI(t *testing.T) {
 			t.Errorf("wrong mnc, got %v", mnc)
 		}
 	})
+
+	t.Run("Test UserLocationInformation with CGI (3-digit MNC)", func(t *testing.T) {
+		ie := NewUserLocationInformationWithCGI("123", "456", 111, 222)
+
+		cgi := ie.MustCGI()
+		if cgi != 222 {
+			t.Errorf("wrong cgi, got %v", cgi)
+		}
+
+		lac := ie.MustLAC()
+		if lac != 111 {
+			t.Errorf("wrong lac, got %v", lac)
+		}
+
+		mcc := ie.MustMCC()
+		if mcc != "123" {
+			t.Errorf("wrong mcc, got %v", mcc)
+		}
+
+		mnc := ie.MustMNC()
+		if mnc != "456" {
+			t.Errorf("wrong mnc, got %v", mnc)
+		}
+	})
 }
 
 func TestUserLocationInformationWithRAI(t *testing.T) {