ByteHook

README 中文版

ByteHook is an Android PLT hook library which supports armeabi-v7a, arm64-v8a, x86 and x86_64.

Most of ByteDance's Android apps(including Douyin, Toutiao, Xigua Video) use ByteHook as the PLT hook solution in production.

If you need an Android inline hook library, please move to ShadowHook.

Features

• Support Android 4.1 - 12 (API level 16 - 31).
• Support armeabi-v7a, arm64-v8a, x86 and x86_64.
• Multiple hooks and unhooks for the same function do not conflict with each other.
• Hook a single, partial or all of the dynamic libraries in the process.
• Hook the newly loaded dynamic libraries automatically.
• Avoid recursive-calls and circular-calls between proxy functions automatically.
• Support unwinding backtrace in proxy function.
• MIT licensed.

Documentation

ByteHook Documentation

Quick Start

There is a sample app in the bytehook-sample you can refer to.

1. Add dependency in build.gradle

ByteHook is published on Maven Central, and uses Prefab package format for native dependencies, which is supported by Android Gradle Plugin 4.0+.

allprojects {
    repositories {
        mavenCentral()
    }
}

android {
    buildFeatures {
        prefab true
    }
}

dependencies {
    implementation 'com.bytedance:bytehook:1.0.5'
}

2. Add dependency in CMakeLists.txt or Android.mk

CMakeLists.txt

find_package(bytehook REQUIRED CONFIG)

add_library(mylib SHARED mylib.c)
target_link_libraries(mylib bytehook::bytehook)

Android.mk

include $(CLEAR_VARS)
LOCAL_MODULE           := mylib
LOCAL_SRC_FILES        := mylib.c
LOCAL_SHARED_LIBRARIES += bytehook
include $(BUILD_SHARED_LIBRARY)

$(call import-module,prefab/bytehook)

3. Specify one or more ABI(s) you need

android {
    defaultConfig {
        ndk {
            abiFilters 'armeabi-v7a', 'arm64-v8a', 'x86', 'x86_64'
        }
    }
}

4. Add packaging options

If you are using ByteHook in an SDK project, you may need to avoid packaging libbytehook.so into your AAR, so as not to encounter duplicate libbytehook.so file when packaging the app project.

android {
    packagingOptions {
        exclude '**/libbytehook.so'
    }
}

On the other hand, if you are using ByteHook in an APP project, you may need to add some options to deal with conflicts caused by duplicate libbytehook.so file.

android {
    packagingOptions {
        pickFirst '**/libbytehook.so'
    }
}

5. Initialize

import com.bytedance.android.bytehook.ByteHook;

public class MySdk {
    public static synchronized void init() {
        ByteHook.init();
    }
}

6. Hook and Unhook

#include "bytehook.h"

bytehook_stub_t bytehook_hook_single(
    const char *caller_path_name,
    const char *callee_path_name,
    const char *sym_name,
    void *new_func,
    bytehook_hooked_t hooked,
    void *hooked_arg);

bytehook_stub_t bytehook_hook_partial(
    bytehook_caller_allow_filter_t caller_allow_filter,
    void *caller_allow_filter_arg,
    const char *callee_path_name,
    const char *sym_name,
    void *new_func,
    bytehook_hooked_t hooked,
    void *hooked_arg);

bytehook_stub_t bytehook_hook_all(
    const char *callee_path_name,
    const char *sym_name,
    void *new_func,
    bytehook_hooked_t hooked,
    void *hooked_arg);

int bytehook_unhook(bytehook_stub_t stub);

These three hook functions are used to hook single, partial, and all caller dynamic libraries in the process.

Notice:

• If you need to call the original function in the proxy function, please always use the BYTEHOOK_CALL_PREV() macro.
• Make sure to call BYTEHOOK_POP_STACK() macro before proxy function returning. In the CPP source file, you can also call BYTEHOOK_STACK_SCOPE() macro at the beginning of the proxy function instead.

Contributing

• Code of Conduct
• Contributing Guide
• Reporting Security vulnerabilities

License

ByteHook is licensed by MIT License.

ByteHook uses the following third-party source code or libraries:

• queue.h
  BSD 3-Clause License
  Copyright (c) 1991, 1993 The Regents of the University of California.
• tree.h
  BSD 2-Clause License
  Copyright (c) 2002 Niels Provos [email protected]
• linux-syscall-support
  BSD 3-Clause License
  Copyright (c) 2005-2011 Google Inc.