1 files changed, 70 insertions, 0 deletions
diff --git a/libs/androidfw/TypeWrappers.cpp b/libs/androidfw/TypeWrappers.cpp
new file mode 100644
index 0000000..8929b66
--- /dev/null
+++ b/libs/androidfw/TypeWrappers.cpp
@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2014 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 <androidfw/TypeWrappers.h>
+
+namespace android {
+
+TypeVariant::iterator& TypeVariant::iterator::operator++() {
+    mIndex++;
+    if (mIndex > dtohl(mTypeVariant->data->entryCount)) {
+        mIndex = dtohl(mTypeVariant->data->entryCount);
+    }
+    return *this;
+}
+
+const ResTable_entry* TypeVariant::iterator::operator*() const {
+    const ResTable_type* type = mTypeVariant->data;
+    const uint32_t entryCount = dtohl(type->entryCount);
+    if (mIndex >= entryCount) {
+        return NULL;
+    }
+
+    const uintptr_t containerEnd = reinterpret_cast<uintptr_t>(type)
+            + dtohl(type->header.size);
+    const uint32_t* const entryIndices = reinterpret_cast<const uint32_t*>(
+            reinterpret_cast<uintptr_t>(type) + dtohs(type->header.headerSize));
+    if (reinterpret_cast<uintptr_t>(entryIndices) + (sizeof(uint32_t) * entryCount) > containerEnd) {
+        ALOGE("Type's entry indices extend beyond its boundaries");
+        return NULL;
+    }
+
+    const uint32_t entryOffset = dtohl(entryIndices[mIndex]);
+    if (entryOffset == ResTable_type::NO_ENTRY) {
+        return NULL;
+    }
+
+    if ((entryOffset & 0x3) != 0) {
+        ALOGE("Index %u points to entry with unaligned offset %p", mIndex, (void*) entryOffset);
+        return NULL;
+    }
+
+    const ResTable_entry* entry = reinterpret_cast<const ResTable_entry*>(
+            reinterpret_cast<uintptr_t>(type) + dtohl(type->entriesStart) + entryOffset);
+    if (reinterpret_cast<uintptr_t>(entry) > containerEnd - sizeof(*entry)) {
+        ALOGE("Entry offset at index %u points outside the Type's boundaries", mIndex);
+        return NULL;
+    } else if (reinterpret_cast<uintptr_t>(entry) + dtohs(entry->size) > containerEnd) {
+        ALOGE("Entry at index %u extends beyond Type's boundaries", mIndex);
+        return NULL;
+    } else if (dtohs(entry->size) < sizeof(*entry)) {
+        ALOGE("Entry at index %u is too small (%u)", mIndex, dtohs(entry->size));
+        return NULL;
+    }
+    return entry;
+}
+
+} // namespace android