commit a0a5d2a9061cfb58b6f7632117502f2061ab74cb
author Kevin Rocard <krocard@google.com> Mon Aug 06 15:03:18 2018 -0700
committer Kevin Rocard <krocard@google.com> Thu Aug 09 09:38:16 2018 -0700
tree 5d97d831dbb49da3617a6b66630a83fee07c8d72
parent 5bf00e8858de16b294174c35b338b99b5a3259fb

Add external setParameter to audioflinger dumpsys

Apps are not expected to send any setParameter, system should only send
very few keys. This log can help verify what is bypassing audioflinger
control.

Only the first 1024 characters are logged per SimpleLog limitation
to avoid high memory retention in the privilege audio service
in case very big strings are sent.

Thus in the worst case around 60*1*3=180kB can be consumed in Audioflinger
by those logs (aka: no app memory deny of service).

Test: adb shell dumpsys media.audio_flinger
Change-Id: Ida9c21be9d20528f67a63eddf6ca7a6c962c7cc2
Signed-off-by: Kevin Rocard <krocard@google.com>

services/audioflinger/AudioFlinger.cpp

diff --git a/services/audioflinger/AudioFlinger.cpp b/services/audioflinger/AudioFlinger.cpp
index 43566b7..ed2b3c0 100644
--- a/services/audioflinger/AudioFlinger.cpp
+++ b/services/audioflinger/AudioFlinger.cpp
@@ -66,7 +66,6 @@
 #include <media/MemoryLeakTrackUtil.h>
 #include <media/nbaio/Pipe.h>
 #include <media/nbaio/PipeReader.h>
-#include <media/AudioParameter.h>
 #include <mediautils/BatteryNotifier.h>
 #include <mediautils/ServiceUtilities.h>
 #include <private/android_filesystem_config.h>
@@ -517,6 +516,15 @@
 
         mPatchPanel.dump(fd);
 
+        // dump external setParameters
+        auto dumpLogger = [fd](SimpleLog& logger, const char* name) {
+            dprintf(fd, "\n%s setParameters:\n", name);
+            logger.dump(fd, "    " /* prefix */);
+        };
+        dumpLogger(mRejectedSetParameterLog, "Rejected");
+        dumpLogger(mAppSetParameterLog, "App");
+        dumpLogger(mSystemSetParameterLog, "System");
+
         BUFLOG_RESET;
 
         if (locked) {
@@ -1229,16 +1237,33 @@
 
     AudioParameter param = AudioParameter(keyValuePairs);
     String8 value;
+    AudioParameter rejectedParam;
     for (auto& key : kReservedParameters) {
         if (param.get(key, value) == NO_ERROR) {
-            ALOGW("%s: filtering key %s value %s from uid %d",
-                  __func__, key.string(), value.string(), callingUid);
+            rejectedParam.add(key, value);
             param.remove(key);
         }
     }
+    logFilteredParameters(param.size() + rejectedParam.size(), keyValuePairs,
+                          rejectedParam.size(), rejectedParam.toString(), callingUid);
     keyValuePairs = param.toString();
 }
 
+void AudioFlinger::logFilteredParameters(size_t originalKVPSize, const String8& originalKVPs,
+                                         size_t rejectedKVPSize, const String8& rejectedKVPs,
+                                         uid_t callingUid) {
+    auto prefix = String8::format("UID %5d", callingUid);
+    auto suffix = String8::format("%zu KVP received: %s", originalKVPSize, originalKVPs.c_str());
+    if (rejectedKVPSize != 0) {
+        auto error = String8::format("%zu KVP rejected: %s", rejectedKVPSize, rejectedKVPs.c_str());
+        ALOGW("%s: %s, %s, %s", __func__, prefix.c_str(), error.c_str(), suffix.c_str());
+        mRejectedSetParameterLog.log("%s, %s, %s", prefix.c_str(), error.c_str(), suffix.c_str());
+    } else {
+        auto& logger = (isServiceUid(callingUid) ? mSystemSetParameterLog : mAppSetParameterLog);
+        logger.log("%s, %s", prefix.c_str(), suffix.c_str());
+    }
+}
+
 status_t AudioFlinger::setParameters(audio_io_handle_t ioHandle, const String8& keyValuePairs)
 {
     ALOGV("setParameters(): io %d, keyvalue %s, calling pid %d calling uid %d",

services/audioflinger/AudioFlinger.h

diff --git a/services/audioflinger/AudioFlinger.h b/services/audioflinger/AudioFlinger.h
index e9e6e94..cc277c3 100644
--- a/services/audioflinger/AudioFlinger.h
+++ b/services/audioflinger/AudioFlinger.h
@@ -811,6 +811,9 @@
     status_t    checkStreamType(audio_stream_type_t stream) const;
 
     void        filterReservedParameters(String8& keyValuePairs, uid_t callingUid);
+    void        logFilteredParameters(size_t originalKVPSize, const String8& originalKVPs,
+                                      size_t rejectedKVPSize, const String8& rejectedKVPs,
+                                      uid_t callingUid);
 
 public:
     // These methods read variables atomically without mLock,
@@ -831,7 +834,11 @@
     PatchPanel mPatchPanel;
     sp<EffectsFactoryHalInterface> mEffectsFactoryHal;
 
-    bool        mSystemReady;
+    bool       mSystemReady;
+
+    SimpleLog  mRejectedSetParameterLog;
+    SimpleLog  mAppSetParameterLog;
+    SimpleLog  mSystemSetParameterLog;
 };
 
 #undef INCLUDING_FROM_AUDIOFLINGER_H