Merge "libbinder: add hasBinders" into main am: 1a06751

Original change: https://android-review.googlesource.com/c/platform/frameworks/native/+/2986295

Change-Id: I07e275dfff55380efa7aa2908937b087a151d9ae
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

Author: Treehugger Robot

libs/binder/Parcel.cpp

@@ -256,7 +256,7 @@ status_t Parcel::flattenBinder(const sp<IBinder>& binder) {
 
     if (const auto* rpcFields = maybeRpcFields()) {
         if (binder) {
-            status_t status = writeInt32(1); // non-null
+            status_t status = writeInt32(RpcFields::TYPE_BINDER); // non-null
             if (status != OK) return status;
             uint64_t address;
             // TODO(b/167966510): need to undo this if the Parcel is not sent
@@ -266,7 +266,7 @@ status_t Parcel::flattenBinder(const sp<IBinder>& binder) {
             status = writeUint64(address);
             if (status != OK) return status;
         } else {
-            status_t status = writeInt32(0); // null
+            status_t status = writeInt32(RpcFields::TYPE_BINDER_NULL); // null
             if (status != OK) return status;
         }
         return finishFlattenBinder(binder);
@@ -740,6 +740,12 @@ bool Parcel::hasFileDescriptors() const
     return kernelFields->mHasFds;
 }
 
+status_t Parcel::hasBinders(bool* result) const {
+    status_t status = hasBindersInRange(0, dataSize(), result);
+    ALOGE_IF(status != NO_ERROR, "Error %d calling hasBindersInRange()", status);
+    return status;
+}
+
 std::vector<sp<IBinder>> Parcel::debugReadAllStrongBinders() const {
     std::vector<sp<IBinder>> ret;
 
@@ -799,6 +805,46 @@ std::vector<int> Parcel::debugReadAllFileDescriptors() const {
     return ret;
 }
 
+status_t Parcel::hasBindersInRange(size_t offset, size_t len, bool* result) const {
+    if (len > INT32_MAX || offset > INT32_MAX) {
+        // Don't accept size_t values which may have come from an inadvertent conversion from a
+        // negative int.
+        return BAD_VALUE;
+    }
+    size_t limit;
+    if (__builtin_add_overflow(offset, len, &limit) || limit > mDataSize) {
+        return BAD_VALUE;
+    }
+    *result = false;
+    if (const auto* kernelFields = maybeKernelFields()) {
+#ifdef BINDER_WITH_KERNEL_IPC
+        for (size_t i = 0; i < kernelFields->mObjectsSize; i++) {
+            size_t pos = kernelFields->mObjects[i];
+            if (pos < offset) continue;
+            if (pos + sizeof(flat_binder_object) > offset + len) {
+                if (kernelFields->mObjectsSorted) {
+                    break;
+                } else {
+                    continue;
+                }
+            }
+            const flat_binder_object* flat =
+                    reinterpret_cast<const flat_binder_object*>(mData + pos);
+            if (flat->hdr.type == BINDER_TYPE_BINDER || flat->hdr.type == BINDER_TYPE_HANDLE) {
+                *result = true;
+                break;
+            }
+        }
+#else
+        LOG_ALWAYS_FATAL("Binder kernel driver disabled at build time");
+        return INVALID_OPERATION;
+#endif // BINDER_WITH_KERNEL_IPC
+    } else if (const auto* rpcFields = maybeRpcFields()) {
+        return INVALID_OPERATION;
+    }
+    return NO_ERROR;
+}
+
 status_t Parcel::hasFileDescriptorsInRange(size_t offset, size_t len, bool* result) const {
     if (len > INT32_MAX || offset > INT32_MAX) {
         // Don't accept size_t values which may have come from an inadvertent conversion from a

libs/binder/include/binder/Parcel.h

@@ -101,7 +101,9 @@ class Parcel {
     void                restoreAllowFds(bool lastValue);
 
     bool                hasFileDescriptors() const;
+    status_t hasBinders(bool* result) const;
     status_t hasFileDescriptorsInRange(size_t offset, size_t length, bool* result) const;
+    status_t hasBindersInRange(size_t offset, size_t length, bool* result) const;
 
     // returns all binder objects in the Parcel
     std::vector<sp<IBinder>> debugReadAllStrongBinders() const;
@@ -647,6 +649,8 @@ class Parcel {
     void                freeDataNoInit();
     void                initState();
     void                scanForFds() const;
+    status_t scanForBinders(bool* result) const;
+
     status_t            validateReadData(size_t len) const;
 
     void                updateWorkSourceRequestHeaderPosition() const;

libs/binder/tests/binderParcelUnitTest.cpp

@@ -23,6 +23,7 @@
 using android::BBinder;
 using android::IBinder;
 using android::IPCThreadState;
+using android::NO_ERROR;
 using android::OK;
 using android::Parcel;
 using android::sp;
@@ -164,6 +165,45 @@ TEST(Parcel, AppendPlainDataPartial) {
     ASSERT_EQ(2, p2.readInt32());
 }
 
+TEST(Parcel, HasBinders) {
+    sp<IBinder> b1 = sp<BBinder>::make();
+
+    Parcel p1;
+    p1.writeInt32(1);
+    p1.writeStrongBinder(b1);
+
+    bool result = false;
+    ASSERT_EQ(NO_ERROR, p1.hasBinders(&result));
+    ASSERT_EQ(true, result);
+
+    p1.setDataSize(0); // clear data
+    result = false;
+    ASSERT_EQ(NO_ERROR, p1.hasBinders(&result));
+    ASSERT_EQ(false, result);
+    p1.writeStrongBinder(b1); // reset with binder data
+    result = false;
+    ASSERT_EQ(NO_ERROR, p1.hasBinders(&result));
+    ASSERT_EQ(true, result);
+
+    Parcel p3;
+    p3.appendFrom(&p1, 0, p1.dataSize());
+    result = false;
+    ASSERT_EQ(NO_ERROR, p1.hasBinders(&result));
+    ASSERT_EQ(true, result);
+}
+
+TEST(Parcel, HasBindersInRange) {
+    sp<IBinder> b1 = sp<BBinder>::make();
+    Parcel p1;
+    p1.writeStrongBinder(b1);
+    bool result = false;
+    ASSERT_EQ(NO_ERROR, p1.hasBindersInRange(0, p1.dataSize(), &result));
+    ASSERT_EQ(true, result);
+    result = false;
+    ASSERT_EQ(NO_ERROR, p1.hasBinders(&result));
+    ASSERT_EQ(true, result);
+}
+
 TEST(Parcel, AppendWithBinder) {
     sp<IBinder> b1 = sp<BBinder>::make();
     sp<IBinder> b2 = sp<BBinder>::make();

libs/binder/tests/parcel_fuzzer/binder.cpp

@@ -352,6 +352,20 @@ std::vector<ParcelRead<::android::Parcel>> BINDER_PARCEL_READ_FUNCTIONS {
         status_t status = p.hasFileDescriptorsInRange(offset, length, &result);
         FUZZ_LOG() << " status: " << status  << " result: " << result;
     },
+    [] (const ::android::Parcel& p, FuzzedDataProvider& /*provider*/) {
+        FUZZ_LOG() << "about to call hasBinders() with status";
+        bool result;
+        status_t status = p.hasBinders(&result);
+        FUZZ_LOG() << " status: " << status  << " result: " << result;
+    },
+    [] (const ::android::Parcel& p, FuzzedDataProvider& /*provider*/) {
+        FUZZ_LOG() << "about to call hasBindersInRange() with status";
+        size_t offset = p.readUint32();
+        size_t length = p.readUint32();
+        bool result;
+        status_t status = p.hasBindersInRange(offset, length, &result);
+        FUZZ_LOG() << " status: " << status  << " result: " << result;
+    },
     [] (const ::android::Parcel& p, FuzzedDataProvider& /*provider*/) {
         FUZZ_LOG() << "about to call compareDataInRange() with status";
         size_t thisOffset = p.readUint32();