Merge "libbinder: added enforceNoDataAvail()"

4 files changed, 36 insertions, 1 deletions

diff --git a/libs/binder/Parcel.cpp b/libs/binder/Parcel.cpp
index 7027a4b0a3..6fb189cd70 100644
--- a/libs/binder/Parcel.cpp
+++ b/libs/binder/Parcel.cpp
@@ -739,6 +739,17 @@ bool Parcel::enforceInterface(const char16_t* interface,
     }
 }
 
+binder::Status Parcel::enforceNoDataAvail() const {
+    const auto n = dataAvail();
+    if (n == 0) {
+        return binder::Status::ok();
+    }
+    return binder::Status::
+            fromExceptionCode(binder::Status::Exception::EX_BAD_PARCELABLE,
+                              String8::format("Parcel data not fully consumed, unread size: %zu",
+                                              n));
+}
+
 size_t Parcel::objectsCount() const
 {
     return mObjectsSize;
diff --git a/libs/binder/include/binder/Parcel.h b/libs/binder/include/binder/Parcel.h
index 8dbdc1d115..450e3888f1 100644
--- a/libs/binder/include/binder/Parcel.h
+++ b/libs/binder/include/binder/Parcel.h
@@ -54,6 +54,9 @@ class ProcessState;
 class RpcSession;
 class String8;
 class TextOutput;
+namespace binder {
+class Status;
+}
 
 class Parcel {
     friend class IPCThreadState;
@@ -131,6 +134,10 @@ public:
                                          IPCThreadState* threadState = nullptr) const;
     bool                checkInterface(IBinder*) const;
 
+    // Verify there are no bytes left to be read on the Parcel.
+    // Returns Status(EX_BAD_PARCELABLE) when the Parcel is not consumed.
+    binder::Status enforceNoDataAvail() const;
+
     void                freeData();
 
     size_t              objectsCount() const;
diff --git a/libs/binder/tests/binderParcelUnitTest.cpp b/libs/binder/tests/binderParcelUnitTest.cpp
index 4950b23858..aee15d8bd9 100644
--- a/libs/binder/tests/binderParcelUnitTest.cpp
+++ b/libs/binder/tests/binderParcelUnitTest.cpp
@@ -16,15 +16,17 @@
 
 #include <binder/IPCThreadState.h>
 #include <binder/Parcel.h>
+#include <binder/Status.h>
 #include <cutils/ashmem.h>
 #include <gtest/gtest.h>
 
 using android::IPCThreadState;
 using android::OK;
 using android::Parcel;
+using android::status_t;
 using android::String16;
 using android::String8;
-using android::status_t;
+using android::binder::Status;
 
 TEST(Parcel, NonNullTerminatedString8) {
     String8 kTestString = String8("test-is-good");
@@ -60,6 +62,19 @@ TEST(Parcel, NonNullTerminatedString16) {
     EXPECT_EQ(output.size(), 0);
 }
 
+TEST(Parcel, EnforceNoDataAvail) {
+    const int32_t kTestInt = 42;
+    const String8 kTestString = String8("test-is-good");
+    Parcel p;
+    p.writeInt32(kTestInt);
+    p.writeString8(kTestString);
+    p.setDataPosition(0);
+    EXPECT_EQ(kTestInt, p.readInt32());
+    EXPECT_EQ(p.enforceNoDataAvail().exceptionCode(), Status::Exception::EX_BAD_PARCELABLE);
+    EXPECT_EQ(kTestString, p.readString8());
+    EXPECT_EQ(p.enforceNoDataAvail().exceptionCode(), Status::Exception::EX_NONE);
+}
+
 // Tests a second operation results in a parcel at the same location as it
 // started.
 void parcelOpSameLength(const std::function<void(Parcel*)>& a, const std::function<void(Parcel*)>& b) {
diff --git a/libs/binder/tests/parcel_fuzzer/binder.cpp b/libs/binder/tests/parcel_fuzzer/binder.cpp
index 077d915ca1..13f7195eb7 100644
--- a/libs/binder/tests/parcel_fuzzer/binder.cpp
+++ b/libs/binder/tests/parcel_fuzzer/binder.cpp
@@ -22,6 +22,7 @@
 #include <android/os/IServiceManager.h>
 #include <binder/ParcelableHolder.h>
 #include <binder/PersistableBundle.h>
+#include <binder/Status.h>
 
 using ::android::status_t;
 using ::android::base::HexString;
@@ -100,6 +101,7 @@ std::vector<ParcelRead<::android::Parcel>> BINDER_PARCEL_READ_FUNCTIONS {
     PARCEL_READ_NO_STATUS(size_t, dataAvail),
     PARCEL_READ_NO_STATUS(size_t, dataPosition),
     PARCEL_READ_NO_STATUS(size_t, dataCapacity),
+    PARCEL_READ_NO_STATUS(::android::binder::Status, enforceNoDataAvail),
     [] (const ::android::Parcel& p, uint8_t pos) {
         FUZZ_LOG() << "about to setDataPosition: " << pos;
         p.setDataPosition(pos);