From c7ecbd8f1eeb779379dbd1db07f2668dc4ed85e5 Mon Sep 17 00:00:00 2001
From: Nathan Harold <nharold@google.com>
Date: Fri, 10 Jul 2020 11:49:34 -0700
Subject: [PATCH] Remove Kernel Command Line Support for CDMA Config

Remove support for the kernel-command-line-based CDMA
modem config flag. Devices must now use the system property,
which is also set at OS compile time and is available before
telephony. Since there's no drawback, and kernel command line
flags are not the right place for this, good riddance.

These APIs were marked @UnsupportedAppUsage; however, the
API to read the command line had zero usage, and the API to
retrieve the CDMA capability had a single app usage with a
very small installed base, so presumably it's legacy hardware.

Bug: 138225216
Test: compilation (no functional change)
Change-Id: Iac7a23056553465e1d05299df7323daf89fbfd66
---
 .../android/telephony/TelephonyManager.java   | 86 +------------------
 1 file changed, 2 insertions(+), 84 deletions(-)

diff --git a/telephony/java/android/telephony/TelephonyManager.java b/telephony/java/android/telephony/TelephonyManager.java
index 6fa94d39dbc74..30a6dfac97a45 100644
--- a/telephony/java/android/telephony/TelephonyManager.java
+++ b/telephony/java/android/telephony/TelephonyManager.java
@@ -110,8 +110,6 @@ import com.android.internal.telephony.RILConstants;
 import com.android.internal.telephony.SmsApplication;
 import com.android.telephony.Rlog;
 
-import java.io.FileInputStream;
-import java.io.IOException;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.util.ArrayList;
@@ -124,8 +122,6 @@ import java.util.Objects;
 import java.util.UUID;
 import java.util.concurrent.Executor;
 import java.util.function.Consumer;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
 
 /**
  * Provides access to information about the telephony services on
@@ -2388,7 +2384,8 @@ public class TelephonyManager {
             return PhoneConstants.PHONE_TYPE_CDMA;
 
         case RILConstants.NETWORK_MODE_LTE_ONLY:
-            if (getLteOnCdmaModeStatic() == PhoneConstants.LTE_ON_CDMA_TRUE) {
+            if (TelephonyProperties.lte_on_cdma_device().orElse(
+                    PhoneConstants.LTE_ON_CDMA_FALSE) == PhoneConstants.LTE_ON_CDMA_TRUE) {
                 return PhoneConstants.PHONE_TYPE_CDMA;
             } else {
                 return PhoneConstants.PHONE_TYPE_GSM;
@@ -2398,35 +2395,6 @@ public class TelephonyManager {
         }
     }
 
-    /**
-     * The contents of the /proc/cmdline file
-     */
-    @UnsupportedAppUsage
-    private static String getProcCmdLine()
-    {
-        String cmdline = "";
-        FileInputStream is = null;
-        try {
-            is = new FileInputStream("/proc/cmdline");
-            byte [] buffer = new byte[2048];
-            int count = is.read(buffer);
-            if (count > 0) {
-                cmdline = new String(buffer, 0, count);
-            }
-        } catch (IOException e) {
-            Rlog.d(TAG, "No /proc/cmdline exception=" + e);
-        } finally {
-            if (is != null) {
-                try {
-                    is.close();
-                } catch (IOException e) {
-                }
-            }
-        }
-        Rlog.d(TAG, "/proc/cmdline=" + cmdline);
-        return cmdline;
-    }
-
     /**
      * @return The max value for the timeout passed in {@link #requestNumberVerification}.
      * @hide
@@ -2436,56 +2404,6 @@ public class TelephonyManager {
         return MAX_NUMBER_VERIFICATION_TIMEOUT_MILLIS;
     }
 
-    /** Kernel command line */
-    private static final String sKernelCmdLine = getProcCmdLine();
-
-    /** Pattern for selecting the product type from the kernel command line */
-    private static final Pattern sProductTypePattern =
-        Pattern.compile("\\sproduct_type\\s*=\\s*(\\w+)");
-
-    /** The ProductType used for LTE on CDMA devices */
-    private static final String sLteOnCdmaProductType =
-            TelephonyProperties.lte_on_cdma_product_type().orElse("");
-
-    /**
-     * Return if the current radio is LTE on CDMA. This
-     * is a tri-state return value as for a period of time
-     * the mode may be unknown.
-     *
-     * @return {@link PhoneConstants#LTE_ON_CDMA_UNKNOWN}, {@link PhoneConstants#LTE_ON_CDMA_FALSE}
-     * or {@link PhoneConstants#LTE_ON_CDMA_TRUE}
-     *
-     * @hide
-     */
-    @UnsupportedAppUsage
-    public static int getLteOnCdmaModeStatic() {
-        int retVal;
-        int curVal;
-        String productType = "";
-
-        curVal = TelephonyProperties.lte_on_cdma_device().orElse(
-            PhoneConstants.LTE_ON_CDMA_UNKNOWN);
-        retVal = curVal;
-        if (retVal == PhoneConstants.LTE_ON_CDMA_UNKNOWN) {
-            Matcher matcher = sProductTypePattern.matcher(sKernelCmdLine);
-            if (matcher.find()) {
-                productType = matcher.group(1);
-                if (sLteOnCdmaProductType.equals(productType)) {
-                    retVal = PhoneConstants.LTE_ON_CDMA_TRUE;
-                } else {
-                    retVal = PhoneConstants.LTE_ON_CDMA_FALSE;
-                }
-            } else {
-                retVal = PhoneConstants.LTE_ON_CDMA_FALSE;
-            }
-        }
-
-        Rlog.d(TAG, "getLteOnCdmaMode=" + retVal + " curVal=" + curVal +
-                " product_type='" + productType +
-                "' lteOnCdmaProductType='" + sLteOnCdmaProductType + "'");
-        return retVal;
-    }
-
     //
     //
     // Current Network