Merge "Adjust APF interpreter tests to match APFv4"

am: 05011abf27

Change-Id: I5ca2b41ab6c101bef7465229270079c81743c757

3 files changed, 42 insertions, 25 deletions

diff --git a/services/net/java/android/net/apf/ApfGenerator.java b/services/net/java/android/net/apf/ApfGenerator.java
index fcfb19ce5a68..99b2fc6db472 100644
--- a/services/net/java/android/net/apf/ApfGenerator.java
+++ b/services/net/java/android/net/apf/ApfGenerator.java
@@ -841,30 +841,30 @@ public class ApfGenerator {
 
     /**
      * Add an instruction to the end of the program to load 32 bits from the data memory into
-     * {@code register}. The source address is computed by adding @{code offset} to the other
-     * register.
+     * {@code register}. The source address is computed by adding the signed immediate
+     * @{code offset} to the other register.
      * Requires APF v3 or greater.
      */
     public ApfGenerator addLoadData(Register destinationRegister, int offset)
             throws IllegalInstructionException {
         requireApfVersion(3);
         Instruction instruction = new Instruction(Opcodes.LDDW, destinationRegister);
-        instruction.setUnsignedImm(offset);
+        instruction.setSignedImm(offset);
         addInstruction(instruction);
         return this;
     }
 
     /**
      * Add an instruction to the end of the program to store 32 bits from {@code register} into the
-     * data memory. The destination address is computed by adding @{code offset} to the other
-     * register.
+     * data memory. The destination address is computed by adding the signed immediate
+     * @{code offset} to the other register.
      * Requires APF v3 or greater.
      */
     public ApfGenerator addStoreData(Register sourceRegister, int offset)
             throws IllegalInstructionException {
         requireApfVersion(3);
         Instruction instruction = new Instruction(Opcodes.STDW, sourceRegister);
-        instruction.setUnsignedImm(offset);
+        instruction.setSignedImm(offset);
         addInstruction(instruction);
         return this;
     }
diff --git a/tests/net/java/android/net/apf/ApfTest.java b/tests/net/java/android/net/apf/ApfTest.java
index 082f3108ed0a..f8a413226bd2 100644
--- a/tests/net/java/android/net/apf/ApfTest.java
+++ b/tests/net/java/android/net/apf/ApfTest.java
@@ -160,7 +160,7 @@ public class ApfTest {
             throw new Exception(
                     "program: " + HexDump.toHexString(program) +
                     "\ndata memory: " + HexDump.toHexString(data) +
-                    "\nexpected: " + HexDump.toHexString(expected_data));
+                    "\nexpected:    " + HexDump.toHexString(expected_data));
         }
     }
 
@@ -625,18 +625,19 @@ public class ApfTest {
     @Test
     public void testApfDataWrite() throws IllegalInstructionException, Exception {
         byte[] packet = new byte[MIN_PKT_SIZE];
-        byte[] data = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16};
+        byte[] data = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
         byte[] expected_data = data.clone();
 
         // No memory access instructions: should leave the data segment untouched.
         ApfGenerator gen = new ApfGenerator(3);
         assertDataMemoryContents(PASS, gen.generate(), packet, data, expected_data);
 
-        // Expect value 0x87654321 to be stored starting from address 3 + 2, in big-endian order.
+        // Expect value 0x87654321 to be stored starting from address -11 from the end of the
+        // data buffer, in big-endian order.
         gen = new ApfGenerator(3);
         gen.addLoadImmediate(Register.R0, 0x87654321);
-        gen.addLoadImmediate(Register.R1, 2);
-        gen.addStoreData(Register.R0, 3);
+        gen.addLoadImmediate(Register.R1, -5);
+        gen.addStoreData(Register.R0, -6);  // -5 + -6 = -11 (offset +5 with data_len=16)
         expected_data[5] = (byte)0x87;
         expected_data[6] = (byte)0x65;
         expected_data[7] = (byte)0x43;
@@ -646,16 +647,16 @@ public class ApfTest {
 
     @Test
     public void testApfDataRead() throws IllegalInstructionException, Exception {
-        // Program that DROPs if address 11 (7 + 3) contains 0x87654321.
+        // Program that DROPs if address 10 (-6) contains 0x87654321.
         ApfGenerator gen = new ApfGenerator(3);
-        gen.addLoadImmediate(Register.R1, 3);
-        gen.addLoadData(Register.R0, 7);
+        gen.addLoadImmediate(Register.R1, 10);
+        gen.addLoadData(Register.R0, -16);  // 10 + -16 = -6 (offset +10 with data_len=16)
         gen.addJumpIfR0Equals(0x87654321, gen.DROP_LABEL);
         byte[] program = gen.generate();
         byte[] packet = new byte[MIN_PKT_SIZE];
 
         // Content is incorrect (last byte does not match) -> PASS
-        byte[] data = new byte[32];
+        byte[] data = new byte[16];
         data[10] = (byte)0x87;
         data[11] = (byte)0x65;
         data[12] = (byte)0x43;
@@ -672,10 +673,10 @@ public class ApfTest {
     @Test
     public void testApfDataReadModifyWrite() throws IllegalInstructionException, Exception {
         ApfGenerator gen = new ApfGenerator(3);
-        gen.addLoadImmediate(Register.R1, 3);
-        gen.addLoadData(Register.R0, 7);  // Load from address 7 + 3 = 10
+        gen.addLoadImmediate(Register.R1, -22);
+        gen.addLoadData(Register.R0, 0);  // Load from address 32 -22 + 0 = 10
         gen.addAdd(0x78453412);  // 87654321 + 78453412 = FFAA7733
-        gen.addStoreData(Register.R0, 11);  // Write back to address 11 + 3 = 14
+        gen.addStoreData(Register.R0, 4);  // Write back to address 32 -22 + 4 = 14
 
         byte[] packet = new byte[MIN_PKT_SIZE];
         byte[] data = new byte[32];
@@ -718,10 +719,17 @@ public class ApfTest {
         gen.addJump(gen.DROP_LABEL);
         assertDataMemoryContents(DROP, gen.generate(), packet, data, expected_data);
 
-        // ...but underflowing isn't allowed.
+        // ...and underflowing simply wraps around to the end of the buffer...
         gen = new ApfGenerator(3);
         gen.addLoadImmediate(Register.R0, 20);
         gen.addLoadData(Register.R1, -30);
+        gen.addJump(gen.DROP_LABEL);
+        assertDataMemoryContents(DROP, gen.generate(), packet, data, expected_data);
+
+        // ...but doesn't allow accesses before the start of the buffer
+        gen = new ApfGenerator(3);
+        gen.addLoadImmediate(Register.R0, 20);
+        gen.addLoadData(Register.R1, -1000);
         gen.addJump(gen.DROP_LABEL);  // Not reached.
         assertDataMemoryContents(PASS, gen.generate(), packet, data, expected_data);
     }
diff --git a/tests/net/jni/apf_jni.cpp b/tests/net/jni/apf_jni.cpp
index 79444e3f5ba8..1ea9e274ab9e 100644
--- a/tests/net/jni/apf_jni.cpp
+++ b/tests/net/jni/apf_jni.cpp
@@ -36,11 +36,20 @@ static jint com_android_server_ApfTest_apfSimulate(
     uint32_t program_len = env->GetArrayLength(program);
     uint32_t packet_len = env->GetArrayLength(packet);
     uint32_t data_len = data ? env->GetArrayLength(data) : 0;
-    jint result = accept_packet(program_raw, program_len, packet_raw,
-                                packet_len, data_raw, data_len, filter_age);
+
+    // Merge program and data into a single buffer.
+    uint8_t* program_and_data = (uint8_t*)malloc(program_len + data_len);
+    memcpy(program_and_data, program_raw, program_len);
+    memcpy(program_and_data + program_len, data_raw, data_len);
+
+    jint result =
+        accept_packet(program_and_data, program_len, program_len + data_len,
+                      packet_raw, packet_len, filter_age);
     if (data) {
+        memcpy(data_raw, program_and_data + program_len, data_len);
         env->ReleaseByteArrayElements(data, (jbyte*)data_raw, 0 /* copy back */);
     }
+    free(program_and_data);
     env->ReleaseByteArrayElements(packet, (jbyte*)packet_raw, JNI_ABORT);
     env->ReleaseByteArrayElements(program, (jbyte*)program_raw, JNI_ABORT);
     return result;
@@ -109,8 +118,8 @@ static jboolean com_android_server_ApfTest_compareBpfApf(JNIEnv* env, jclass, js
         jstring jpcap_filename, jbyteArray japf_program) {
     ScopedUtfChars filter(env, jfilter);
     ScopedUtfChars pcap_filename(env, jpcap_filename);
-    const uint8_t* apf_program = (uint8_t*)env->GetByteArrayElements(japf_program, NULL);
-    const uint32_t apf_program_len = env->GetArrayLength(japf_program);
+    uint8_t* apf_program = (uint8_t*)env->GetByteArrayElements(japf_program, NULL);
+    uint32_t apf_program_len = env->GetArrayLength(japf_program);
 
     // Open pcap file for BPF filtering
     ScopedFILE bpf_fp(fopen(pcap_filename.c_str(), "rb"));
@@ -152,8 +161,8 @@ static jboolean com_android_server_ApfTest_compareBpfApf(JNIEnv* env, jclass, js
         do {
             apf_packet = pcap_next(apf_pcap.get(), &apf_header);
         } while (apf_packet != NULL && !accept_packet(
-                apf_program, apf_program_len, apf_packet, apf_header.len,
-                nullptr, 0, 0));
+                apf_program, apf_program_len, 0 /* data_len */,
+                apf_packet, apf_header.len, 0 /* filter_age */));
 
         // Make sure both filters matched the same packet.
         if (apf_packet == NULL && bpf_packet == NULL)