Merge "Skip the status message parsing correctly even if it's truncated." into main am: de06b5477b

Original change: https://android-review.googlesource.com/c/platform/packages/modules/NetworkStack/+/2890975

Change-Id: Ic9de68b13c90cf87f808ac1b6dbc6bfde9d3ef6a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

src/android/net/dhcp6/Dhcp6Packet.java

diff --git a/src/android/net/dhcp6/Dhcp6Packet.java b/src/android/net/dhcp6/Dhcp6Packet.java
index 6ed6d2d..53dd274 100644
--- a/src/android/net/dhcp6/Dhcp6Packet.java
+++ b/src/android/net/dhcp6/Dhcp6Packet.java
@@ -274,7 +274,7 @@
                             statusCode = buffer.getShort();
                             // Skip the status message if any.
                             if (optionLen > 2) {
-                                buffer.position(buffer.position() + (optionLen - 2));
+                                skipOption(buffer, optionLen - 2);
                             }
                             break;
                         default:
@@ -506,7 +506,7 @@
                         // suitable for display to the end user, but is not useful for Dhcp6Client
                         // to decide how to properly handle the status code.
                         if (optionLen - 2 > 0) {
-                            packet.position(packet.position() + (optionLen - 2));
+                            skipOption(packet, optionLen - 2);
                         }
                         break;
                     case DHCP6_SOL_MAX_RT:

tests/unit/src/android/net/dhcp6/Dhcp6PacketTest.kt

diff --git a/tests/unit/src/android/net/dhcp6/Dhcp6PacketTest.kt b/tests/unit/src/android/net/dhcp6/Dhcp6PacketTest.kt
index 3bf87af..32cf464 100644
--- a/tests/unit/src/android/net/dhcp6/Dhcp6PacketTest.kt
+++ b/tests/unit/src/android/net/dhcp6/Dhcp6PacketTest.kt
@@ -332,4 +332,56 @@
         assertEquals(0, packet.mPrefixDelegation.t2)
         assertEquals(Dhcp6Packet.STATUS_NO_PREFIX_AVAIL, packet.mPrefixDelegation.statusCode)
     }
+
+    @Test
+    fun testStatusCodeOptionWithTruncatedStatusMessage() {
+        val replyHex =
+            // Reply, Transaction ID
+            "07000A47" +
+            // server identifier option(option_len=10)
+            "0002000A0003000186C9B26AED4D" +
+            // client identifier option(option_len=12)
+            "0001000C0003001B02FBBAFFFEB7BC71" +
+            // SOL_MAX_RT (don't support this option yet)
+            "005200040000003c" +
+            // Rapid Commit
+            "000e0000" +
+            // DNS recursive server (don't support this opton yet)
+            "00170010fdfd9ed6795000000000000000000001" +
+            // Status code option: len=21, status code=NoPrefixAvail
+            "000d00150006" +
+            // Status code option: truncated status message="no prefix available"
+            "6e6f2070726566697820617661696c6162"
+        val bytes = HexDump.hexStringToByteArray(replyHex)
+        assertThrows(Dhcp6Packet.ParseException::class.java) {
+            Dhcp6Packet.decode(bytes, bytes.size)
+        }
+    }
+
+    @Test
+    fun testStatusCodeOptionInIaPdWithTruncatedStatusMessage() {
+        val replyHex =
+            // Reply, Transaction ID
+            "07000A47" +
+            // server identifier option(option_len=10)
+            "0002000A0003000186C9B26AED4D" +
+            // client identifier option(option_len=12)
+            "0001000C0003001B02FBBAFFFEB7BC71" +
+            // SOL_MAX_RT (don't support this option yet)
+            "005200040000003c" +
+            // Rapid Commit
+            "000e0000" +
+            // DNS recursive server (don't support this opton yet)
+            "00170010fdfd9ed6795000000000000000000001" +
+            // IA_PD option (t1=t2=0, empty prefix)
+            "00190025000000000000000000000000" +
+            // Status code option: len=21, status code=NoPrefixAvail
+            "000d00150006" +
+            // truncated status message="no prefix available")
+            "6e6f2070726566697820617661696c6162"
+        val bytes = HexDump.hexStringToByteArray(replyHex)
+        assertThrows(Dhcp6Packet.ParseException::class.java) {
+            Dhcp6Packet.decode(bytes, bytes.size)
+        }
+    }
 }