From 78eb48e53600198b04517210bc23977e59484e2c Mon Sep 17 00:00:00 2001
From: Nathan Harold <nharold@google.com>
Date: Mon, 26 Feb 2018 20:31:04 -0800
Subject: [PATCH] Set CDMA Location to Invalid if on Null Island

If the reported CDMA location is ~= (0, 0), which
is in the middle of the Gulf of Guinea, assert that
there are no CDMA cell towers within range (there
are not) and force the location to a saner default
value of Integer.MAX_VALUE which is out of the range
of valid lats+longs.

Bug: 32364031
Test: runtest frameworks-telephony
Change-Id: I3f50054dd37cf7cef56b1bd16c3313c02da34c31
---
 .../android/telephony/CellIdentityCdma.java   | 20 +++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/telephony/java/android/telephony/CellIdentityCdma.java b/telephony/java/android/telephony/CellIdentityCdma.java
index 2e1d1dc343cd8..105ddb0e8f255 100644
--- a/telephony/java/android/telephony/CellIdentityCdma.java
+++ b/telephony/java/android/telephony/CellIdentityCdma.java
@@ -103,8 +103,12 @@ public final class CellIdentityCdma extends CellIdentity {
         mNetworkId = nid;
         mSystemId = sid;
         mBasestationId = bid;
-        mLongitude = lon;
-        mLatitude = lat;
+        if (!isNullIsland(lat, lon)) {
+            mLongitude = lon;
+            mLatitude = lat;
+        } else {
+            mLongitude = mLatitude = Integer.MAX_VALUE;
+        }
         mAlphaLong = alphal;
         mAlphaShort = alphas;
     }
@@ -118,6 +122,18 @@ public final class CellIdentityCdma extends CellIdentity {
         return new CellIdentityCdma(this);
     }
 
+    /**
+     * Take the latitude and longitude in 1/4 seconds and see if
+     * the reported location is on Null Island.
+     *
+     * @return whether the reported Lat/Long are for Null Island
+     *
+     * @hide
+     */
+    private boolean isNullIsland(int lat, int lon) {
+        return Math.abs(lat) <= 1 && Math.abs(lon) <= 1;
+    }
+
     /**
      * @return Network Id 0..65535, Integer.MAX_VALUE if unknown
      */