Factor out and speed up permission-checking code
Use the caching permission check for dump to save IPC.
Cache getpid() to save kernel call for other permission checks.
The C runtime library getpid() can't cache due to a fork
race condition, but we know that mediaserver doesn't fork.
Don't construct String16 on the stack.
Change-Id: I6be6161dae5155d39ba6ed6228e7683e67be34ed
diff --git a/services/audioflinger/Android.mk b/services/audioflinger/Android.mk
index deeb2de..157405a 100644
--- a/services/audioflinger/Android.mk
+++ b/services/audioflinger/Android.mk
@@ -6,7 +6,8 @@
AudioFlinger.cpp \
AudioMixer.cpp.arm \
AudioResampler.cpp.arm \
- AudioPolicyService.cpp
+ AudioPolicyService.cpp \
+ ServiceUtilities.cpp
# AudioResamplerSinc.cpp.arm
# AudioResamplerCubic.cpp.arm
diff --git a/services/audioflinger/AudioFlinger.cpp b/services/audioflinger/AudioFlinger.cpp
index bbc9196..5c964b2 100644
--- a/services/audioflinger/AudioFlinger.cpp
+++ b/services/audioflinger/AudioFlinger.cpp
@@ -48,6 +48,7 @@
#include "AudioMixer.h"
#include "AudioFlinger.h"
+#include "ServiceUtilities.h"
#include <media/EffectsFactoryApi.h>
#include <audio_effects/effect_visualizer.h>
@@ -101,20 +102,6 @@
// ----------------------------------------------------------------------------
-static bool recordingAllowed() {
- if (getpid() == IPCThreadState::self()->getCallingPid()) return true;
- bool ok = checkCallingPermission(String16("android.permission.RECORD_AUDIO"));
- if (!ok) ALOGE("Request requires android.permission.RECORD_AUDIO");
- return ok;
-}
-
-static bool settingsAllowed() {
- if (getpid() == IPCThreadState::self()->getCallingPid()) return true;
- bool ok = checkCallingPermission(String16("android.permission.MODIFY_AUDIO_SETTINGS"));
- if (!ok) ALOGE("Request requires android.permission.MODIFY_AUDIO_SETTINGS");
- return ok;
-}
-
// To collect the amplifier usage
static void addBatteryData(uint32_t params) {
sp<IMediaPlayerService> service = IMediaDeathNotifier::getMediaPlayerService();
@@ -321,7 +308,7 @@
status_t AudioFlinger::dump(int fd, const Vector<String16>& args)
{
- if (!checkCallingPermission(String16("android.permission.DUMP"))) {
+ if (!dumpAllowed()) {
dumpPermissionDenial(fd, args);
} else {
// get state of hardware lock
@@ -3436,7 +3423,7 @@
uint32_t vlr = mCblk->getVolumeLR();
snprintf(buffer, size, " %05d %05d %03u %03u 0x%08x %05u %04u %1d %1d %1d %05u %05u %05u 0x%08x 0x%08x 0x%08x 0x%08x\n",
mName - AudioMixer::TRACK0,
- (mClient == 0) ? getpid() : mClient->pid(),
+ (mClient == 0) ? getpid_cached : mClient->pid(),
mStreamType,
mFormat,
mChannelMask,
@@ -3757,7 +3744,7 @@
void AudioFlinger::RecordThread::RecordTrack::dump(char* buffer, size_t size)
{
snprintf(buffer, size, " %05d %03u 0x%08x %05d %04u %01d %05u %08x %08x\n",
- (mClient == 0) ? getpid() : mClient->pid(),
+ (mClient == 0) ? getpid_cached : mClient->pid(),
mFormat,
mChannelMask,
mSessionId,
@@ -5404,7 +5391,7 @@
// Session AUDIO_SESSION_OUTPUT_STAGE is reserved for output stage effects
// that can only be created by audio policy manager (running in same process)
- if (sessionId == AUDIO_SESSION_OUTPUT_STAGE && getpid() != pid) {
+ if (sessionId == AUDIO_SESSION_OUTPUT_STAGE && getpid_cached != pid) {
lStatus = PERMISSION_DENIED;
goto Exit;
}
@@ -7022,7 +7009,7 @@
bool locked = mCblk != NULL && tryLock(mCblk->lock);
snprintf(buffer, size, "\t\t\t%05d %05d %01u %01u %05u %05u\n",
- (mClient == 0) ? getpid() : mClient->pid(),
+ (mClient == 0) ? getpid_cached : mClient->pid(),
mPriority,
mHasControl,
!locked,
diff --git a/services/audioflinger/AudioPolicyService.cpp b/services/audioflinger/AudioPolicyService.cpp
index f8b430e..21b5811 100644
--- a/services/audioflinger/AudioPolicyService.cpp
+++ b/services/audioflinger/AudioPolicyService.cpp
@@ -30,6 +30,7 @@
#include <utils/String16.h>
#include <utils/threads.h>
#include "AudioPolicyService.h"
+#include "ServiceUtilities.h"
#include <cutils/properties.h>
#include <hardware_legacy/power.h>
#include <media/AudioEffect.h>
@@ -49,13 +50,6 @@
static const int kDumpLockRetries = 50;
static const int kDumpLockSleepUs = 20000;
-static bool checkPermission() {
- if (getpid() == IPCThreadState::self()->getCallingPid()) return true;
- bool ok = checkCallingPermission(String16("android.permission.MODIFY_AUDIO_SETTINGS"));
- if (!ok) ALOGE("Request requires android.permission.MODIFY_AUDIO_SETTINGS");
- return ok;
-}
-
namespace {
extern struct audio_policy_service_ops aps_ops;
};
@@ -157,7 +151,7 @@
if (mpAudioPolicy == NULL) {
return NO_INIT;
}
- if (!checkPermission()) {
+ if (!settingsAllowed()) {
return PERMISSION_DENIED;
}
if (!audio_is_output_device(device) && !audio_is_input_device(device)) {
@@ -190,7 +184,7 @@
if (mpAudioPolicy == NULL) {
return NO_INIT;
}
- if (!checkPermission()) {
+ if (!settingsAllowed()) {
return PERMISSION_DENIED;
}
if (uint32_t(state) >= AUDIO_MODE_CNT) {
@@ -213,7 +207,7 @@
if (mpAudioPolicy == NULL) {
return NO_INIT;
}
- if (!checkPermission()) {
+ if (!settingsAllowed()) {
return PERMISSION_DENIED;
}
if (usage < 0 || usage >= AUDIO_POLICY_FORCE_USE_CNT) {
@@ -388,7 +382,7 @@
if (mpAudioPolicy == NULL) {
return NO_INIT;
}
- if (!checkPermission()) {
+ if (!settingsAllowed()) {
return PERMISSION_DENIED;
}
if (uint32_t(stream) >= AUDIO_STREAM_CNT) {
@@ -405,7 +399,7 @@
if (mpAudioPolicy == NULL) {
return NO_INIT;
}
- if (!checkPermission()) {
+ if (!settingsAllowed()) {
return PERMISSION_DENIED;
}
if (uint32_t(stream) >= AUDIO_STREAM_CNT) {
@@ -578,7 +572,7 @@
status_t AudioPolicyService::dump(int fd, const Vector<String16>& args)
{
- if (!checkCallingPermission(String16("android.permission.DUMP"))) {
+ if (!dumpAllowed()) {
dumpPermissionDenial(fd);
} else {
bool locked = tryLock(mLock);
diff --git a/services/audioflinger/ServiceUtilities.cpp b/services/audioflinger/ServiceUtilities.cpp
new file mode 100644
index 0000000..6a58852
--- /dev/null
+++ b/services/audioflinger/ServiceUtilities.cpp
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <binder/IPCThreadState.h>
+#include <binder/IServiceManager.h>
+#include <binder/PermissionCache.h>
+#include "ServiceUtilities.h"
+
+namespace android {
+
+// This optimization assumes mediaserver process doesn't fork, which it doesn't
+const pid_t getpid_cached = getpid();
+
+bool recordingAllowed() {
+ if (getpid_cached == IPCThreadState::self()->getCallingPid()) return true;
+ static const String16 sRecordAudio("android.permission.RECORD_AUDIO");
+ // don't use PermissionCache; this is not a system permission
+ bool ok = checkCallingPermission(sRecordAudio);
+ if (!ok) ALOGE("Request requires android.permission.RECORD_AUDIO");
+ return ok;
+}
+
+bool settingsAllowed() {
+ if (getpid_cached == IPCThreadState::self()->getCallingPid()) return true;
+ static const String16 sAudioSettings("android.permission.MODIFY_AUDIO_SETTINGS");
+ // don't use PermissionCache; this is not a system permission
+ bool ok = checkCallingPermission(sAudioSettings);
+ if (!ok) ALOGE("Request requires android.permission.MODIFY_AUDIO_SETTINGS");
+ return ok;
+}
+
+bool dumpAllowed() {
+ // don't optimize for same pid, since mediaserver never dumps itself
+ static const String16 sDump("android.permission.DUMP");
+ // OK to use PermissionCache; this is a system permission
+ bool ok = PermissionCache::checkCallingPermission(sDump);
+ // convention is for caller to dump an error message to fd instead of logging here
+ //if (!ok) ALOGE("Request requires android.permission.DUMP");
+ return ok;
+}
+
+} // namespace android
diff --git a/services/audioflinger/ServiceUtilities.h b/services/audioflinger/ServiceUtilities.h
new file mode 100644
index 0000000..f77ec5b
--- /dev/null
+++ b/services/audioflinger/ServiceUtilities.h
@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <unistd.h>
+
+namespace android {
+
+extern const pid_t getpid_cached;
+
+bool recordingAllowed();
+bool settingsAllowed();
+bool dumpAllowed();
+
+}