Merge "Add some useful helpers and constants."

3 files changed, 37 insertions, 0 deletions

diff --git a/core/java/com/android/internal/util/BitUtils.java b/core/java/com/android/internal/util/BitUtils.java
index 1b354d0d9df0..eabe3b910b78 100644
--- a/core/java/com/android/internal/util/BitUtils.java
+++ b/core/java/com/android/internal/util/BitUtils.java
@@ -91,6 +91,10 @@ public final class BitUtils {
         return s & 0xffff;
     }
 
+    public static int uint16(byte hi, byte lo) {
+        return ((hi & 0xff) << 8) | (lo & 0xff);
+    }
+
     public static long uint32(int i) {
         return i & 0xffffffffL;
     }
diff --git a/services/net/java/android/net/util/NetworkConstants.java b/services/net/java/android/net/util/NetworkConstants.java
index 606526816368..5a3a8be923af 100644
--- a/services/net/java/android/net/util/NetworkConstants.java
+++ b/services/net/java/android/net/util/NetworkConstants.java
@@ -107,6 +107,20 @@ public final class NetworkConstants {
     public static final int RFC6177_MIN_PREFIX_LENGTH = 48;
 
     /**
+     * ICMP common (v4/v6) constants.
+     *
+     * See also:
+     *     - https://tools.ietf.org/html/rfc792
+     *     - https://tools.ietf.org/html/rfc4443
+     */
+    public static final int ICMP_HEADER_TYPE_OFFSET = 0;
+    public static final int ICMP_HEADER_CODE_OFFSET = 1;
+    public static final int ICMP_HEADER_CHECKSUM_OFFSET = 2;
+    public static final int ICMP_ECHO_IDENTIFIER_OFFSET = 4;
+    public static final int ICMP_ECHO_SEQUENCE_NUMBER_OFFSET = 6;
+    public static final int ICMP_ECHO_DATA_OFFSET = 8;
+
+    /**
      * ICMPv6 constants.
      *
      * See also:
diff --git a/tests/net/java/com/android/internal/util/BitUtilsTest.java b/tests/net/java/com/android/internal/util/BitUtilsTest.java
index 0ad8a21f7712..f4dc12ab8348 100644
--- a/tests/net/java/com/android/internal/util/BitUtilsTest.java
+++ b/tests/net/java/com/android/internal/util/BitUtilsTest.java
@@ -56,6 +56,25 @@ public class BitUtilsTest {
     }
 
     @Test
+    public void testUnsignedShortComposition() {
+        byte b0 = 0;
+        byte b1 = 1;
+        byte b2 = 2;
+        byte b10 = 10;
+        byte b16 = 16;
+        byte b128 = -128;
+        byte b224 = -32;
+        byte b255 = -1;
+        assertEquals(0x0000, uint16(b0, b0));
+        assertEquals(0xffff, uint16(b255, b255));
+        assertEquals(0x0a01, uint16(b10, b1));
+        assertEquals(0x8002, uint16(b128, b2));
+        assertEquals(0x01ff, uint16(b1, b255));
+        assertEquals(0x80ff, uint16(b128, b255));
+        assertEquals(0xe010, uint16(b224, b16));
+    }
+
+    @Test
     public void testUnsignedIntWideningConversions() {
         assertEquals(0, uint32(0));
         assertEquals(1, uint32(1));