BpfBitmap: some minor optimizations
Test: TreeHugger, atest BpfBitmapTest
Flag: EXEMPT mainline
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I5acf5bcb31777e503e58cef733d617a53006d2b9
diff --git a/Tethering/jni/onload.cpp b/Tethering/jni/onload.cpp
index fd40d41..606cc44 100644
--- a/Tethering/jni/onload.cpp
+++ b/Tethering/jni/onload.cpp
@@ -23,6 +23,7 @@
namespace android {
int register_com_android_net_module_util_BpfMap(JNIEnv* env, char const* class_name);
+int register_com_android_net_module_util_BpfBitmap(JNIEnv* env, char const* class_name);
int register_com_android_net_module_util_TcUtils(JNIEnv* env, char const* class_name);
int register_com_android_networkstack_tethering_BpfCoordinator(JNIEnv* env);
int register_com_android_networkstack_tethering_util_TetheringUtils(JNIEnv* env);
@@ -39,6 +40,9 @@
if (register_com_android_net_module_util_BpfMap(env,
"com/android/networkstack/tethering/util/BpfMap") < 0) return JNI_ERR;
+ if (register_com_android_net_module_util_BpfBitmap(env,
+ "com/android/networkstack/tethering/util/BpfBitmap") < 0) return JNI_ERR;
+
if (register_com_android_net_module_util_TcUtils(env,
"com/android/networkstack/tethering/util/TcUtils") < 0) return JNI_ERR;
diff --git a/service/jni/com_android_net_module_util/onload.cpp b/service/jni/com_android_net_module_util/onload.cpp
index d91eb03..f160622 100644
--- a/service/jni/com_android_net_module_util/onload.cpp
+++ b/service/jni/com_android_net_module_util/onload.cpp
@@ -20,6 +20,7 @@
namespace android {
int register_com_android_net_module_util_BpfMap(JNIEnv* env, char const* class_name);
+int register_com_android_net_module_util_BpfBitmap(JNIEnv* env, char const* class_name);
int register_com_android_net_module_util_TcUtils(JNIEnv* env, char const* class_name);
int register_com_android_net_module_util_BpfUtils(JNIEnv* env, char const* class_name);
@@ -33,6 +34,9 @@
if (register_com_android_net_module_util_BpfMap(env,
"android/net/connectivity/com/android/net/module/util/BpfMap") < 0) return JNI_ERR;
+ if (register_com_android_net_module_util_BpfBitmap(env,
+ "android/net/connectivity/com/android/net/module/util/BpfBitmap") < 0) return JNI_ERR;
+
if (register_com_android_net_module_util_TcUtils(env,
"android/net/connectivity/com/android/net/module/util/TcUtils") < 0) return JNI_ERR;
diff --git a/staticlibs/device/com/android/net/module/util/BpfBitmap.java b/staticlibs/device/com/android/net/module/util/BpfBitmap.java
index b62a430..8f45c65 100644
--- a/staticlibs/device/com/android/net/module/util/BpfBitmap.java
+++ b/staticlibs/device/com/android/net/module/util/BpfBitmap.java
@@ -22,6 +22,8 @@
import androidx.annotation.NonNull;
import androidx.annotation.RequiresApi;
+import dalvik.annotation.optimization.CriticalNative;
+
/**
*
* Generic bitmap class for use with BPF programs. Corresponds to a BpfMap
@@ -30,7 +32,12 @@
*/
@RequiresApi(Build.VERSION_CODES.S)
public class BpfBitmap {
- private BpfMap<Struct.S32, Struct.S64> mBpfMap;
+ static {
+ System.loadLibrary(JniUtil.getJniLibraryName(BpfBitmap.class.getPackage()));
+ }
+
+ private final BpfMap<Struct.S32, Struct.S64> mBpfMap;
+ private final int mMapFd;
/**
* Create a BpfBitmap map wrapper with "path" of filesystem.
@@ -39,21 +46,16 @@
*/
public BpfBitmap(@NonNull String path) throws ErrnoException {
mBpfMap = new BpfMap<>(path, Struct.S32.class, Struct.S64.class);
+ mMapFd = mBpfMap.getFd();
}
- /**
- * Retrieves the value from BpfMap for the given key.
- *
- * @param key The key in the map corresponding to the value to return.
- */
- private long getBpfMapValue(Struct.S32 key) throws ErrnoException {
- Struct.S64 curVal = mBpfMap.getValue(key);
- if (curVal != null) {
- return curVal.val;
- } else {
- return 0;
- }
- }
+ // Returns > 0 if bit is set, 0 if not set, < 0 on error (negative errno).
+ @CriticalNative
+ private static native int nativeGet(int fd, int index);
+
+ // Returns 0 on success, < 0 on error (negative errno).
+ @CriticalNative
+ private static native int nativeSet(int fd, int index, boolean set);
/**
* Retrieves the bit for the given index in the bitmap.
@@ -63,8 +65,26 @@
public boolean get(int index) throws ErrnoException {
if (index < 0) return false;
- Struct.S32 key = new Struct.S32(index >> 6);
- return ((getBpfMapValue(key) >>> (index & 63)) & 1L) != 0;
+ final int ret = nativeGet(mMapFd, index);
+ if (ret < 0) {
+ throw new ErrnoException("nativeGet", -ret);
+ }
+ return ret > 0;
+ }
+
+ /**
+ * Change the specified index in the bitmap to set value.
+ *
+ * @param index Position to (un)set in bitmap.
+ * @param set Boolean indicating to set or unset index.
+ */
+ public void set(int index, boolean set) throws ErrnoException {
+ if (index < 0) throw new IllegalArgumentException("Index out of bounds.");
+
+ final int ret = nativeSet(mMapFd, index, set);
+ if (ret < 0) {
+ throw new ErrnoException("nativeSet", -ret);
+ }
}
/**
@@ -86,22 +106,6 @@
}
/**
- * Change the specified index in the bitmap to set value.
- *
- * @param index Position to unset in bitmap.
- * @param set Boolean indicating to set or unset index.
- */
- public void set(int index, boolean set) throws ErrnoException {
- if (index < 0) throw new IllegalArgumentException("Index out of bounds.");
-
- Struct.S32 key = new Struct.S32(index >> 6);
- long mask = (1L << (index & 63));
- long val = getBpfMapValue(key);
- if (set) val |= mask; else val &= ~mask;
- mBpfMap.updateEntry(key, new Struct.S64(val));
- }
-
- /**
* Clears the map. The map may already be empty.
*
* @throws ErrnoException if updating entry to 0 fails.
@@ -118,7 +122,8 @@
public boolean isEmpty() throws ErrnoException {
Struct.S32 key = mBpfMap.getFirstKey();
while (key != null) {
- if (getBpfMapValue(key) != 0) {
+ Struct.S64 val = mBpfMap.getValue(key);
+ if (val != null && val.val != 0) {
return false;
}
key = mBpfMap.getNextKey(key);
diff --git a/staticlibs/device/com/android/net/module/util/BpfMap.java b/staticlibs/device/com/android/net/module/util/BpfMap.java
index da04c73..72cb430 100644
--- a/staticlibs/device/com/android/net/module/util/BpfMap.java
+++ b/staticlibs/device/com/android/net/module/util/BpfMap.java
@@ -71,6 +71,11 @@
private final int mKeySize;
private final int mValueSize;
+ // The following is (ab)used by BpfBitmap.java
+ /* package */ int getFd() {
+ return mMapFd.getFd();
+ }
+
private static ConcurrentHashMap<Pair<String, Integer>, ParcelFileDescriptor> sFdCache =
new ConcurrentHashMap<>();
diff --git a/staticlibs/native/bpfmapjni/Android.bp b/staticlibs/native/bpfmapjni/Android.bp
index 9a58a93..2612ec5 100644
--- a/staticlibs/native/bpfmapjni/Android.bp
+++ b/staticlibs/native/bpfmapjni/Android.bp
@@ -20,7 +20,7 @@
cc_library_static {
name: "libnet_utils_device_common_bpfjni",
srcs: [
- "com_android_net_module_util_BpfMap.cpp",
+ "com_android_net_module_util_Bpf.cpp",
"com_android_net_module_util_TcUtils.cpp",
],
header_libs: [
diff --git a/staticlibs/native/bpfmapjni/com_android_net_module_util_BpfMap.cpp b/staticlibs/native/bpfmapjni/com_android_net_module_util_Bpf.cpp
similarity index 77%
rename from staticlibs/native/bpfmapjni/com_android_net_module_util_BpfMap.cpp
rename to staticlibs/native/bpfmapjni/com_android_net_module_util_Bpf.cpp
index 38cc92c..f0e7246 100644
--- a/staticlibs/native/bpfmapjni/com_android_net_module_util_BpfMap.cpp
+++ b/staticlibs/native/bpfmapjni/com_android_net_module_util_Bpf.cpp
@@ -16,6 +16,7 @@
#include <errno.h>
#include <linux/pfkeyv2.h>
+#include <stdint.h>
#include <sys/socket.h>
#include <jni.h>
#include <nativehelper/JNIHelp.h>
@@ -143,10 +144,47 @@
return 0;
}
+static jint com_android_net_module_util_BpfBitmap_nativeGet(jint fd, jint index) {
+ if (index < 0) return -EINVAL;
+
+ const uint32_t key = index >> 6;
+ const uint32_t subkey = index & 63;
+ uint64_t value = 0;
+
+ // findMapEntry returns 0 on success, -1 on error.
+ // If the entry does not exist, it's not an error, the value is just 0.
+ if (bpf::findMapEntry(fd, &key, &value) && errno != ENOENT) return -errno;
+
+ return (value >> subkey) & 1;
+}
+
+static jint com_android_net_module_util_BpfBitmap_nativeSet(jint fd, jint index, jboolean set) {
+ if (index < 0) return -EINVAL;
+
+ const uint32_t key = index >> 6;
+ const uint32_t subkey = index & 63;
+ uint64_t value = 0;
+
+ // Read the existing value. It's okay if it doesn't exist, value will be 0.
+ if (bpf::findMapEntry(fd, &key, &value) && errno != ENOENT) return -errno;
+
+ const uint64_t mask = 1uLL << subkey;
+ if (set) {
+ value |= mask;
+ } else {
+ value &= ~mask;
+ }
+
+ // Write the updated value back. BPF_ANY will create or update as needed.
+ if (bpf::writeToMapEntry(fd, &key, &value, BPF_ANY)) return -errno;
+
+ return 0;
+}
+
/*
* JNI registration.
*/
-static const JNINativeMethod gMethods[] = {
+static const JNINativeMethod gBpfMapMethods[] = {
/* name, signature, funcPtr */
{ "nativeBpfFdGet", "(Ljava/lang/String;III)I",
(void*) com_android_net_module_util_BpfMap_nativeBpfFdGet },
@@ -165,9 +203,19 @@
};
int register_com_android_net_module_util_BpfMap(JNIEnv* env, char const* class_name) {
- return jniRegisterNativeMethods(env,
- class_name,
- gMethods, NELEM(gMethods));
+ return jniRegisterNativeMethods(env, class_name, gBpfMapMethods, NELEM(gBpfMapMethods));
+}
+
+static const JNINativeMethod gBpfBitmapMethods[] = {
+ /* name, signature, funcPtr */
+ // CriticalNative
+ { "nativeGet", "(II)I", (void*)com_android_net_module_util_BpfBitmap_nativeGet },
+ // CriticalNative
+ { "nativeSet", "(IIZ)I", (void*)com_android_net_module_util_BpfBitmap_nativeSet },
+};
+
+int register_com_android_net_module_util_BpfBitmap(JNIEnv* env, char const* class_name) {
+ return jniRegisterNativeMethods(env, class_name, gBpfBitmapMethods, NELEM(gBpfBitmapMethods));
}
}; // namespace android
diff --git a/tests/common/tethering-jni-jarjar-rules.txt b/tests/common/tethering-jni-jarjar-rules.txt
index 593ba14..3dfd77a 100644
--- a/tests/common/tethering-jni-jarjar-rules.txt
+++ b/tests/common/tethering-jni-jarjar-rules.txt
@@ -5,6 +5,7 @@
# jarjar rules the test is using, but this is a bit less realistic (using a different JNI library),
# and complicates the test build. It would be necessary if TetheringUtils had a different package
# name in test code though, as the JNI library name is deducted from the TetheringUtils package.
+rule com.android.net.module.util.BpfBitmap* com.android.networkstack.tethering.util.BpfBitmap@1
rule com.android.net.module.util.BpfMap* com.android.networkstack.tethering.util.BpfMap@1
rule com.android.net.module.util.BpfUtils* com.android.networkstack.tethering.util.BpfUtils@1
rule com.android.net.module.util.TcUtils* com.android.networkstack.tethering.util.TcUtils@1
diff --git a/tests/unit/jni/android_net_frameworktests_util/onload.cpp b/tests/unit/jni/android_net_frameworktests_util/onload.cpp
index f70b04b..b79a230 100644
--- a/tests/unit/jni/android_net_frameworktests_util/onload.cpp
+++ b/tests/unit/jni/android_net_frameworktests_util/onload.cpp
@@ -23,6 +23,7 @@
namespace android {
int register_com_android_net_module_util_BpfMap(JNIEnv* env, char const* class_name);
+int register_com_android_net_module_util_BpfBitmap(JNIEnv* env, char const* class_name);
int register_com_android_net_module_util_TcUtils(JNIEnv* env, char const* class_name);
int register_com_android_net_module_util_ServiceConnectivityJni(JNIEnv *env,
char const *class_name);
@@ -37,6 +38,9 @@
if (register_com_android_net_module_util_BpfMap(env,
"android/net/frameworktests/util/BpfMap") < 0) return JNI_ERR;
+ if (register_com_android_net_module_util_BpfBitmap(env,
+ "android/net/frameworktests/util/BpfBitmap") < 0) return JNI_ERR;
+
if (register_com_android_net_module_util_TcUtils(env,
"android/net/frameworktests/util/TcUtils") < 0) return JNI_ERR;
