1 files changed, 24 insertions, 3 deletions
diff --git a/telephony/java/android/telephony/CellIdentity.java b/telephony/java/android/telephony/CellIdentity.java
index 432978d1c866..b7dab161c331 100644
--- a/telephony/java/android/telephony/CellIdentity.java
+++ b/telephony/java/android/telephony/CellIdentity.java
@@ -35,6 +35,15 @@ public abstract class CellIdentity implements Parcelable {
     /** @hide */
     public static final int INVALID_CHANNEL_NUMBER = -1;
 
+    /**
+     * parameters for validation
+     * @hide
+     */
+    public static final int MCC_LENGTH = 3;
+
+    private static final int MNC_MIN_LENGTH = 2;
+    private static final int MNC_MAX_LENGTH = 3;
+
     // Log tag
     /** @hide */
     protected final String mTag;
@@ -207,6 +216,17 @@ public abstract class CellIdentity implements Parcelable {
         dest.writeString(mAlphaShort);
     }
 
+    /** Used by phone interface manager to verify if a given string is valid MccMnc
+     * @hide
+     */
+    public static boolean isValidPlmn(@NonNull String plmn) {
+        if (plmn.length() < MCC_LENGTH + MNC_MIN_LENGTH
+                || plmn.length() > MCC_LENGTH + MNC_MAX_LENGTH) {
+            return false;
+        }
+        return (isMcc(plmn.substring(0, MCC_LENGTH)) && isMnc(plmn.substring(MCC_LENGTH)));
+    }
+
     /**
      * Construct from Parcel
      * @hide
@@ -267,10 +287,10 @@ public abstract class CellIdentity implements Parcelable {
     /** @hide */
     private static boolean isMcc(@NonNull String mcc) {
         // ensure no out of bounds indexing
-        if (mcc.length() != 3) return false;
+        if (mcc.length() != MCC_LENGTH) return false;
 
         // Character.isDigit allows all unicode digits, not just [0-9]
-        for (int i = 0; i < 3; i++) {
+        for (int i = 0; i < MCC_LENGTH; i++) {
             if (mcc.charAt(i) < '0' || mcc.charAt(i) > '9') return false;
         }
 
@@ -280,7 +300,7 @@ public abstract class CellIdentity implements Parcelable {
     /** @hide */
     private static boolean isMnc(@NonNull String mnc) {
         // ensure no out of bounds indexing
-        if (mnc.length() < 2 || mnc.length() > 3) return false;
+        if (mnc.length() < MNC_MIN_LENGTH || mnc.length() > MNC_MAX_LENGTH) return false;
 
         // Character.isDigit allows all unicode digits, not just [0-9]
         for (int i = 0; i < mnc.length(); i++) {
@@ -289,4 +309,5 @@ public abstract class CellIdentity implements Parcelable {
 
         return true;
     }
+
 }