Fix bug #1873249i: Apps can DoS/brick device

This is the problem where various things are listening for broadcasts
(such as battery status, PIN/PUK/Network) that an application can send
to cause harm to the system.

Solving this is tricky because many of these broadcasts are sticky,
and I have never figured out how to do permissions with sticky
broadcasts in a sane way.  So instead, I am going to punt on the
general problem and just brute force it:

There is new a way for system components to declare specific
broadcast actions to be protected, which means that only the system
and the phone can send them.  This is good enough for now.  None
of it is exposed in the public API so we can make something a little
less stupid in the future if we ever need to.

1 files changed, 33 insertions, 0 deletions

diff --git a/telephony/java/com/android/internal/telephony/TelephonyIntents.java b/telephony/java/com/android/internal/telephony/TelephonyIntents.java
index 9152211..02e9800 100644
--- a/telephony/java/com/android/internal/telephony/TelephonyIntents.java
+++ b/telephony/java/com/android/internal/telephony/TelephonyIntents.java
@@ -32,6 +32,9 @@ public class TelephonyIntents {
      *
      * <p class="note">
      * Requires the READ_PHONE_STATE permission.
+     * 
+     * <p class="note">This is a protected intent that can only be sent
+     * by the system.
      */
     public static final String ACTION_SERVICE_STATE_CHANGED = "android.intent.action.SERVICE_STATE";
 
@@ -50,6 +53,9 @@ public class TelephonyIntents {
      *
      * <p class="note">
      * Requires no permission.
+     * 
+     * <p class="note">This is a protected intent that can only be sent
+     * by the system.
      */
     public static final String ACTION_RADIO_TECHNOLOGY_CHANGED
             = "android.intent.action.RADIO_TECHNOLOGY";
@@ -66,6 +72,9 @@ public class TelephonyIntents {
      *
      * <p class="note">
      * Requires no permission.
+     * 
+     * <p class="note">This is a protected intent that can only be sent
+     * by the system.
      */
     public static final String ACTION_EMERGENCY_CALLBACK_MODE_CHANGED
             = "android.intent.action.EMERGENCY_CALLBACK_MODE_CHANGED";
@@ -89,6 +98,9 @@ public class TelephonyIntents {
      *
      * <p class="note">
      * Requires the READ_PHONE_STATE permission.
+     * 
+     * <p class="note">This is a protected intent that can only be sent
+     * by the system.
      */
     public static final String ACTION_SIGNAL_STRENGTH_CHANGED = "android.intent.action.SIG_STR";
 
@@ -110,6 +122,9 @@ public class TelephonyIntents {
      *
      * <p class="note">
      * Requires the READ_PHONE_STATE permission.
+     * 
+     * <p class="note">This is a protected intent that can only be sent
+     * by the system.
      */
     public static final String ACTION_ANY_DATA_CONNECTION_STATE_CHANGED
             = "android.intent.action.ANY_DATA_STATE";
@@ -127,6 +142,9 @@ public class TelephonyIntents {
      *
      * <p class="note">
      * Requires the READ_PHONE_STATE permission.
+     * 
+     * <p class="note">This is a protected intent that can only be sent
+     * by the system.
      */
     public static final String ACTION_DATA_CONNECTION_FAILED
             = "android.intent.action.DATA_CONNECTION_FAILED";
@@ -148,6 +166,9 @@ public class TelephonyIntents {
      *
      * <p class="note">
      * Requires the READ_PHONE_STATE permission.
+     * 
+     * <p class="note">This is a protected intent that can only be sent
+     * by the system.
      */
     public static final String ACTION_SIM_STATE_CHANGED
             = "android.intent.action.SIM_STATE_CHANGED";
@@ -163,6 +184,9 @@ public class TelephonyIntents {
      *
      * <p class="note">
      * Requires the READ_PHONE_STATE permission.
+     * 
+     * <p class="note">This is a protected intent that can only be sent
+     * by the system.
      */
     public static final String ACTION_NETWORK_SET_TIME = "android.intent.action.NETWORK_SET_TIME";
 
@@ -178,6 +202,9 @@ public class TelephonyIntents {
      *
      * <p class="note">
      * Requires the READ_PHONE_STATE permission.
+     * 
+     * <p class="note">This is a protected intent that can only be sent
+     * by the system.
      */
     public static final String ACTION_NETWORK_SET_TIMEZONE
             = "android.intent.action.NETWORK_SET_TIMEZONE";
@@ -187,6 +214,9 @@ public class TelephonyIntents {
      * <p class="note">.
      * This is to pop up a notice to show user that the phone is in emergency callback mode
      * and atacalls and outgoing sms are blocked.
+     * 
+     * <p class="note">This is a protected intent that can only be sent
+     * by the system.
      */
     public static final String ACTION_SHOW_NOTICE_ECM_BLOCK_OTHERS
             = "android.intent.action.ACTION_SHOW_NOTICE_ECM_BLOCK_OTHERS";
@@ -197,6 +227,9 @@ public class TelephonyIntents {
      * <ul>
      *   <li><em>mdn</em> - An Integer of the updated MDN number.</li>
      * </ul>
+     * 
+     * <p class="note">This is a protected intent that can only be sent
+     * by the system.
      *
      * <p class="note">
      */