Add OBB file helper class (b94a9a66) · Commits · e / os / android_frameworks_native-old

include/utils/ObbFile.h

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		/*
		* Copyright (C) 2010 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.
		*/

		#ifndef OBBFILE_H_
		#define OBBFILE_H_

		#include <stdint.h>

		#include <utils/RefBase.h>
		#include <utils/String8.h>

		namespace android {

		class ObbFile : public RefBase {
		protected:
		virtual ~ObbFile();

		public:
		ObbFile();

		bool readFrom(const char* filename);
		bool readFrom(int fd);
		bool writeTo(const char* filename);
		bool writeTo(int fd);

		const char* getFileName() const {
		return mFileName;
		}

		const String8 getPackageName() const {
		return mPackageName;
		}

		int32_t getVersion() const {
		return mVersion;
		}

		void setPackageName(String8 packageName) {
		mPackageName = packageName;
		}

		void setVersion(int32_t version) {
		mVersion = version;
		}

		static inline uint32_t get4LE(const unsigned char* buf) {
		return buf[0] \| (buf[1] << 8) \| (buf[2] << 16) \| (buf[3] << 24);
		}

		static inline void put4LE(unsigned char* buf, uint32_t val) {
		buf[0] = val & 0xFF;
		buf[1] = (val >> 8) & 0xFF;
		buf[2] = (val >> 16) & 0xFF;
		buf[3] = (val >> 24) & 0xFF;
		}

		private:
		/* Package name this ObbFile is associated with */
		String8 mPackageName;

		/* Package version this ObbFile is associated with */
		int32_t mVersion;

		const char* mFileName;

		size_t mFileSize;

		unsigned char* mReadBuf;

		bool parseObbFile(int fd);
		};

		}
		#endif /* OBBFILE_H_ */

libs/utils/Android.mk

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		@@ -26,6 +26,7 @@ commonSources:= \
		Debug.cpp \
		FileMap.cpp \
		Flattenable.cpp \
		ObbFile.cpp \
		Pool.cpp \
		RefBase.cpp \
		ResourceTypes.cpp \
		@@ -65,6 +66,11 @@ LOCAL_CFLAGS += -DMB_CUR_MAX=1
		endif
		endif

		ifeq ($(HOST_OS),darwin)
		# MacOS doesn't have lseek64. However, off_t is 64-bit anyway.
		LOCAL_CFLAGS += -DOFF_T_IS_64_BIT
		endif

		include $(BUILD_HOST_STATIC_LIBRARY)

libs/utils/ObbFile.cpp

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+284 −0

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		/*
		* Copyright (C) 2010 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 <errno.h>
		#include <fcntl.h>
		#include <stdint.h>
		#include <stdlib.h>
		#include <string.h>
		#include <unistd.h>

		#define LOG_TAG "ObbFile"
		#include <utils/Log.h>
		#include <utils/ObbFile.h>

		//#define DEBUG 1

		#define kFooterTagSize 8 /* last two 32-bit integers */

		#define kFooterMinSize 21 /* 32-bit signature version
		* 32-bit package version
		* 32-bit package name size
		* 1-character package name
		* 32-bit footer size
		* 32-bit footer marker
		*/

		#define kMaxBufSize 32768 /* Maximum file read buffer */

		#define kSignature 0x01059983U /* ObbFile signature */

		#define kSigVersion 1 /* We only know about signature version 1 */

		/* offsets in version 1 of the header */
		#define kPackageVersionOffset 4
		#define kPackageNameLenOffset 8
		#define kPackageNameOffset 12

		/*
		* TEMP_FAILURE_RETRY is defined by some, but not all, versions of
		* <unistd.h>. (Alas, it is not as standard as we'd hoped!) So, if it's
		* not already defined, then define it here.
		*/
		#ifndef TEMP_FAILURE_RETRY
		/* Used to retry syscalls that can return EINTR. */
		#define TEMP_FAILURE_RETRY(exp) ({ \
		typeof (exp) _rc; \
		do { \
		_rc = (exp); \
		} while (_rc == -1 && errno == EINTR); \
		_rc; })
		#endif

		/*
		* Work around situations where off_t is 64-bit and use off64_t in
		* situations where it's 32-bit.
		*/
		#ifdef OFF_T_IS_64_BIT
		#define my_lseek64 lseek
		typedef off_t my_off64_t;
		#else
		#define my_lseek64 lseek64
		typedef off64_t my_off64_t;
		#endif

		namespace android {

		ObbFile::ObbFile() :
		mVersion(-1) {
		}

		ObbFile::~ObbFile() {
		}

		bool ObbFile::readFrom(const char* filename)
		{
		int fd;
		bool success = false;

		fd = ::open(filename, O_RDONLY);
		if (fd < 0) {
		goto out;
		}
		success = readFrom(fd);
		close(fd);

		out:
		if (!success) {
		LOGW("failed to read from %s\n", filename);
		}
		return success;
		}

		bool ObbFile::readFrom(int fd)
		{
		if (fd < 0) {
		LOGW("failed to read file\n");
		return false;
		}

		return parseObbFile(fd);
		}

		bool ObbFile::parseObbFile(int fd)
		{
		my_off64_t fileLength = my_lseek64(fd, 0, SEEK_END);

		if (fileLength < kFooterMinSize) {
		if (fileLength < 0) {
		LOGW("error seeking in ObbFile: %s\n", strerror(errno));
		} else {
		LOGW("file is only %lld (less than %d minimum)\n", fileLength, kFooterMinSize);
		}
		return false;
		}

		ssize_t actual;
		size_t footerSize;

		{
		my_lseek64(fd, fileLength - kFooterTagSize, SEEK_SET);

		char *footer = new char[kFooterTagSize];
		actual = TEMP_FAILURE_RETRY(read(fd, footer, kFooterTagSize));
		if (actual != kFooterTagSize) {
		LOGW("couldn't read footer signature: %s\n", strerror(errno));
		return false;
		}

		unsigned int fileSig = get4LE((unsigned char*)footer + sizeof(int32_t));
		if (fileSig != kSignature) {
		LOGW("footer didn't match magic string (expected 0x%08x; got 0x%08x)\n",
		kSignature, fileSig);
		return false;
		}

		footerSize = get4LE((unsigned char*)footer);
		if (footerSize > (size_t)fileLength - kFooterTagSize
		\|\| footerSize > kMaxBufSize) {
		LOGW("claimed footer size is too large (0x%08lx; file size is 0x%08llx)\n",
		footerSize, fileLength);
		return false;
		}
		}

		my_off64_t fileOffset = fileLength - footerSize - kFooterTagSize;
		if (my_lseek64(fd, fileOffset, SEEK_SET) != fileOffset) {
		LOGW("seek %lld failed: %s\n", fileOffset, strerror(errno));
		return false;
		}

		size_t readAmount = kMaxBufSize;
		if (readAmount > footerSize)
		readAmount = footerSize;

		char* scanBuf = (char*)malloc(readAmount);
		if (scanBuf == NULL) {
		LOGW("couldn't allocate scanBuf: %s\n", strerror(errno));
		return false;
		}

		actual = TEMP_FAILURE_RETRY(read(fd, scanBuf, readAmount));
		// readAmount is guaranteed to be less than kMaxBufSize
		if (actual != (ssize_t)readAmount) {
		LOGI("couldn't read ObbFile footer: %s\n", strerror(errno));
		free(scanBuf);
		return false;
		}

		#ifdef DEBUG
		for (int i = 0; i < readAmount; ++i) {
		LOGI("char: 0x%02x", scanBuf[i]);
		}
		#endif

		uint32_t sigVersion = get4LE((unsigned char*)scanBuf);
		if (sigVersion != kSigVersion) {
		LOGW("Unsupported ObbFile version %d\n", sigVersion);
		free(scanBuf);
		return false;
		}

		mVersion = (int32_t) get4LE((unsigned char*)scanBuf + kPackageVersionOffset);

		uint32_t packageNameLen = get4LE((unsigned char*)scanBuf + kPackageNameLenOffset);
		if (packageNameLen <= 0
		\|\| packageNameLen > (footerSize - kPackageNameOffset)) {
		LOGW("bad ObbFile package name length (0x%08x)\n", packageNameLen);
		free(scanBuf);
		return false;
		}

		char* packageName = reinterpret_cast<char*>(scanBuf + kPackageNameOffset);
		mPackageName = String8(const_cast<char*>(packageName), packageNameLen);

		free(scanBuf);
		return true;
		}

		bool ObbFile::writeTo(const char* filename)
		{
		int fd;
		bool success = false;

		fd = ::open(filename, O_WRONLY);
		if (fd < 0) {
		goto out;
		}
		success = writeTo(fd);
		close(fd);

		out:
		if (!success) {
		LOGW("failed to write to %s: %s\n", filename, strerror(errno));
		}
		return success;
		}

		bool ObbFile::writeTo(int fd)
		{
		if (fd < 0) {
		return false;
		}

		if (mPackageName.size() == 0 \|\| mVersion == -1) {
		LOGW("tried to write uninitialized ObbFile data");
		return false;
		}

		unsigned char intBuf[sizeof(uint32_t)+1];
		memset(&intBuf, 0, sizeof(intBuf));

		put4LE(intBuf, kSigVersion);
		if (write(fd, &intBuf, sizeof(uint32_t)) != (ssize_t)sizeof(uint32_t)) {
		LOGW("couldn't write signature version: %s", strerror(errno));
		return false;
		}

		put4LE(intBuf, mVersion);
		if (write(fd, &intBuf, sizeof(uint32_t)) != (ssize_t)sizeof(uint32_t)) {
		LOGW("couldn't write package version");
		return false;
		}

		size_t packageNameLen = mPackageName.size();
		put4LE(intBuf, packageNameLen);
		if (write(fd, &intBuf, sizeof(uint32_t)) != (ssize_t)sizeof(uint32_t)) {
		LOGW("couldn't write package name length: %s", strerror(errno));
		return false;
		}

		if (write(fd, mPackageName.string(), packageNameLen) != (ssize_t)packageNameLen) {
		LOGW("couldn't write package name: %s", strerror(errno));
		return false;
		}

		put4LE(intBuf, 3*sizeof(uint32_t) + packageNameLen);
		if (write(fd, &intBuf, sizeof(uint32_t)) != (ssize_t)sizeof(uint32_t)) {
		LOGW("couldn't write footer size: %s", strerror(errno));
		return false;
		}

		put4LE(intBuf, kSignature);
		if (write(fd, &intBuf, sizeof(uint32_t)) != (ssize_t)sizeof(uint32_t)) {
		LOGW("couldn't write footer magic signature: %s", strerror(errno));
		return false;
		}

		return true;
		}

		}

libs/utils/tests/Android.mk

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		@@ -3,6 +3,7 @@ LOCAL_PATH := $(call my-dir)
		include $(CLEAR_VARS)

		test_src_files := \
		ObbFile_test.cpp \
		PollLoop_test.cpp

		shared_libraries := \

libs/utils/tests/ObbFile_test.cpp

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		/*
		* Copyright (C) 2010 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.
		*/

		#define LOG_TAG "ObbFile_test"
		#include <utils/Log.h>
		#include <utils/ObbFile.h>
		#include <utils/RefBase.h>
		#include <utils/String8.h>

		#include <gtest/gtest.h>

		namespace android {

		#define TEST_FILENAME "/test.obb"

		class ObbFileTest : public testing::Test {
		protected:
		sp<ObbFile> mObbFile;
		char* mExternalStorage;
		char* mFileName;

		virtual void SetUp() {
		mObbFile = new ObbFile();
		mExternalStorage = getenv("EXTERNAL_STORAGE");

		const int totalLen = strlen(mExternalStorage) + strlen(TEST_FILENAME) + 1;
		mFileName = new char[totalLen];
		snprintf(mFileName, totalLen, "%s%s", mExternalStorage, TEST_FILENAME);
		}

		virtual void TearDown() {
		}
		};

		TEST_F(ObbFileTest, ReadFailure) {
		EXPECT_FALSE(mObbFile->readFrom(-1))
		<< "No failure on invalid file descriptor";
		}

		TEST_F(ObbFileTest, WriteThenRead) {
		const char* packageName = "com.example.obbfile";
		const int32_t versionNum = 1;

		mObbFile->setPackageName(String8(packageName));
		mObbFile->setVersion(versionNum);

		EXPECT_TRUE(mObbFile->writeTo(mFileName))
		<< "couldn't write to fake .obb file";

		mObbFile = new ObbFile();

		EXPECT_TRUE(mObbFile->readFrom(mFileName))
		<< "couldn't read from fake .obb file";

		EXPECT_EQ(versionNum, mObbFile->getVersion())
		<< "version didn't come out the same as it went in";
		const char* currentPackageName = mObbFile->getPackageName().string();
		EXPECT_STREQ(packageName, currentPackageName)
		<< "package name didn't come out the same as it went in";
		}

		}