#include <android/dlext.h>
#include <sys/mount.h>
#include <dlfcn.h>
#include <regex.h>
#include <bitset>
#include <list>
#include <map>
#include <array>

#include <lsplt.hpp>

#include <fcntl.h>
#include <sys/prctl.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <unistd.h>

#include "dl.h"
#include "daemon.h"
#include "zygisk.hpp"
#include "module.hpp"
#include "files.hpp"
#include "misc.hpp"

#include "solist.hpp"

#include "art_method.hpp"

using namespace std;

static void hook_unloader();
static void unhook_functions();

namespace {

enum {
    POST_SPECIALIZE,
    APP_FORK_AND_SPECIALIZE,
    APP_SPECIALIZE,
    SERVER_FORK_AND_SPECIALIZE,
    DO_REVERT_UNMOUNT,
    SKIP_FD_SANITIZATION,

    FLAG_MAX
};

#define DCL_PRE_POST(name) \
void name##_pre();         \
void name##_post();

#define MAX_FD_SIZE 1024

struct ZygiskContext;

// Current context
ZygiskContext *g_ctx;

struct ZygiskContext {
    JNIEnv *env;
    union {
        void *ptr;
        AppSpecializeArgs_v5 *app;
        ServerSpecializeArgs_v1 *server;
    } args;

    const char *process;
    list<ZygiskModule> modules;

    int pid;
    bitset<FLAG_MAX> flags;
    uint32_t info_flags;
    bitset<MAX_FD_SIZE> allowed_fds;
    vector<int> exempted_fds;

    struct RegisterInfo {
        regex_t regex;
        string symbol;
        void *callback;
        void **backup;
    };

    struct IgnoreInfo {
        regex_t regex;
        string symbol;
    };

    pthread_mutex_t hook_info_lock;
    vector<RegisterInfo> register_info;
    vector<IgnoreInfo> ignore_info;

    ZygiskContext(JNIEnv *env, void *args) :
    env(env), args{args}, process(nullptr), pid(-1), info_flags(0),
    hook_info_lock(PTHREAD_MUTEX_INITIALIZER) {
        g_ctx = this;
    }
    ~ZygiskContext();

    /* Zygisksu changed: Load module fds */
    void run_modules_pre();
    void run_modules_post();
    DCL_PRE_POST(fork)
    DCL_PRE_POST(app_specialize)
    DCL_PRE_POST(nativeForkAndSpecialize)
    DCL_PRE_POST(nativeSpecializeAppProcess)
    DCL_PRE_POST(nativeForkSystemServer)

    void sanitize_fds();
    bool exempt_fd(int fd);
    bool is_child() const { return pid <= 0; }

    // Compatibility shim
    void plt_hook_register(const char *regex, const char *symbol, void *fn, void **backup);
    void plt_hook_exclude(const char *regex, const char *symbol);
    void plt_hook_process_regex();

    bool plt_hook_commit();
};

#undef DCL_PRE_POST

// Global variables
vector<tuple<dev_t, ino_t, const char *, void **>> *plt_hook_list;
map<string, vector<JNINativeMethod>, StringCmp> *jni_hook_list;
bool should_unmap_zygisk = false;

} // namespace

namespace {

#define DCL_HOOK_FUNC(ret, func, ...) \
ret (*old_##func)(__VA_ARGS__);       \
ret new_##func(__VA_ARGS__)

// Skip actual fork and return cached result if applicable
DCL_HOOK_FUNC(int, fork) {
    return (g_ctx && g_ctx->pid >= 0) ? g_ctx->pid : old_fork();
}

// Unmount stuffs in the process's private mount namespace
DCL_HOOK_FUNC(int, unshare, int flags) {
    int res = old_unshare(flags);
    if (g_ctx && (flags & CLONE_NEWNS) != 0 && res == 0 &&
        // For some unknown reason, unmounting app_process in SysUI can break.
        // This is reproducible on the official AVD running API 26 and 27.
        // Simply avoid doing any unmounts for SysUI to avoid potential issues.
        (g_ctx->info_flags & PROCESS_IS_SYS_UI) == 0) {
        if (g_ctx->flags[DO_REVERT_UNMOUNT]) {
            if (g_ctx->info_flags & PROCESS_ROOT_IS_KSU) {
                revert_unmount_ksu();
            } else if (g_ctx->info_flags & PROCESS_ROOT_IS_APATCH){
                revert_unmount_apatch();
            } else if (g_ctx->info_flags & PROCESS_ROOT_IS_MAGISK) {
                revert_unmount_magisk();
            }
        }

        /* Zygisksu changed: No umount app_process */

        // Restore errno back to 0
        errno = 0;
    }
    return res;
}

// Close logd_fd if necessary to prevent crashing
// For more info, check comments in zygisk_log_write
DCL_HOOK_FUNC(void, android_log_close) {
    if (g_ctx == nullptr) {
        // Happens during un-managed fork like nativeForkApp, nativeForkUsap
        logging::setfd(-1);
    } else if (!g_ctx->flags[SKIP_FD_SANITIZATION]) {
        logging::setfd(-1);
    }
    old_android_log_close();
}

// We cannot directly call `dlclose` to unload ourselves, otherwise when `dlclose` returns,
// it will return to our code which has been unmapped, causing segmentation fault.
// Instead, we hook `pthread_attr_destroy` which will be called when VM daemon threads start.
DCL_HOOK_FUNC(int, pthread_attr_destroy, void *target) {
    int res = old_pthread_attr_destroy((pthread_attr_t *)target);

    // Only perform unloading on the main thread
    if (gettid() != getpid())
        return res;

    LOGV("pthread_attr_destroy\n");
    if (should_unmap_zygisk) {
        unhook_functions();
        if (should_unmap_zygisk) {
            // Because both `pthread_attr_destroy` and `dlclose` have the same function signature,
            // we can use `musttail` to let the compiler reuse our stack frame and thus
            // `dlclose` will directly return to the caller of `pthread_attr_destroy`.
            [[clang::musttail]] return dlclose(self_handle);
        }
    }

    return res;
}

void initialize_jni_hook();

DCL_HOOK_FUNC(char *, strdup, const char *s) {
  if (strcmp(s, "com.android.internal.os.ZygoteInit") == 0) {
      LOGV("strdup %s\n", s);
      initialize_jni_hook();
    }

    return old_strdup(s);
}

#undef DCL_HOOK_FUNC

// -----------------------------------------------------------------

static bool can_hook_jni = false;
static jint MODIFIER_NATIVE = 0;
static jmethodID member_getModifiers = nullptr;

void hookJniNativeMethods(JNIEnv *env, const char *clz, JNINativeMethod *methods, int numMethods) {
    if (!can_hook_jni) return;
    auto clazz = env->FindClass(clz);
    if (clazz == nullptr) {
        env->ExceptionClear();
        for (int i = 0; i < numMethods; i++) {
            methods[i].fnPtr = nullptr;
        }
        return;
    }

    vector<JNINativeMethod> hooks;
    for (int i = 0; i < numMethods; i++) {
        auto &nm = methods[i];
        auto mid = env->GetMethodID(clazz, nm.name, nm.signature);
        bool is_static = false;
        if (mid == nullptr) {
            env->ExceptionClear();
            mid = env->GetStaticMethodID(clazz, nm.name, nm.signature);
            is_static = true;
        }
        if (mid == nullptr) {
            env->ExceptionClear();
            nm.fnPtr = nullptr;
            continue;
        }
        auto method = lsplant::JNI_ToReflectedMethod(env, clazz, mid, is_static);
        auto modifier = lsplant::JNI_CallIntMethod(env, method, member_getModifiers);
        if ((modifier & MODIFIER_NATIVE) == 0) {
            nm.fnPtr = nullptr;
            continue;
        }
        auto artMethod = lsplant::art::ArtMethod::FromReflectedMethod(env, method);
        hooks.push_back(nm);
        auto orig = artMethod->GetData();
        LOGV("replaced %s %s orig %p", clz, nm.name, orig);
        nm.fnPtr = orig;
    }

    if (hooks.empty()) return;
    env->RegisterNatives(clazz, hooks.data(), hooks.size());
}

// JNI method hook definitions, auto generated
#include "jni_hooks.hpp"

void initialize_jni_hook() {
    auto get_created_java_vms = reinterpret_cast<jint (*)(JavaVM **, jsize, jsize *)>(
            dlsym(RTLD_DEFAULT, "JNI_GetCreatedJavaVMs"));
    if (!get_created_java_vms) {
        for (auto &map: lsplt::MapInfo::Scan()) {
            if (!map.path.ends_with("/libnativehelper.so")) continue;
            void *h = dlopen(map.path.data(), RTLD_LAZY);
            if (!h) {
                LOGW("cannot dlopen libnativehelper.so: %s\n", dlerror());
                break;
            }
            get_created_java_vms = reinterpret_cast<decltype(get_created_java_vms)>(dlsym(h, "JNI_GetCreatedJavaVMs"));
            dlclose(h);
            break;
        }
        if (!get_created_java_vms) {
            LOGW("JNI_GetCreatedJavaVMs not found\n");
            return;
        }
    }
    JavaVM *vm = nullptr;
    jsize num = 0;
    jint res = get_created_java_vms(&vm, 1, &num);
    if (res != JNI_OK || vm == nullptr) return;
    JNIEnv *env = nullptr;
    res = vm->GetEnv(reinterpret_cast<void **>(&env), JNI_VERSION_1_6);
    if (res != JNI_OK || env == nullptr) return;

    auto classMember = lsplant::JNI_FindClass(env, "java/lang/reflect/Member");
    if (classMember != nullptr) member_getModifiers = lsplant::JNI_GetMethodID(env, classMember, "getModifiers", "()I");
    auto classModifier = lsplant::JNI_FindClass(env, "java/lang/reflect/Modifier");
    if (classModifier != nullptr) {
        auto fieldId = lsplant::JNI_GetStaticFieldID(env, classModifier, "NATIVE", "I");
        if (fieldId != nullptr) MODIFIER_NATIVE = lsplant::JNI_GetStaticIntField(env, classModifier, fieldId);
    }
    if (member_getModifiers == nullptr || MODIFIER_NATIVE == 0) return;
    if (!lsplant::art::ArtMethod::Init(env)) {
        LOGE("failed to init ArtMethod");
        return;
    }

    can_hook_jni = true;
    do_hook_zygote(env);
}

// -----------------------------------------------------------------

ZygiskModule::ZygiskModule(int id, void *handle, void *entry)
: id(id), handle(handle), entry{entry}, api{}, mod{nullptr} {
    // Make sure all pointers are null
    memset(&api, 0, sizeof(api));
    api.base.impl = this;
    api.base.registerModule = &ZygiskModule::RegisterModuleImpl;
}

bool ZygiskModule::RegisterModuleImpl(ApiTable *api, long *module) {
    if (api == nullptr || module == nullptr)
        return false;

    long api_version = *module;
    // Unsupported version
    if (api_version > ZYGISK_API_VERSION)
        return false;

    // Set the actual module_abi*
    api->base.impl->mod = { module };

    // Fill in API accordingly with module API version
    if (api_version >= 1) {
        api->v1.hookJniNativeMethods = hookJniNativeMethods;
        api->v1.pltHookRegister = [](auto a, auto b, auto c, auto d) {
            if (g_ctx) g_ctx->plt_hook_register(a, b, c, d);
        };
        api->v1.pltHookExclude = [](auto a, auto b) {
            if (g_ctx) g_ctx->plt_hook_exclude(a, b);
        };
        api->v1.pltHookCommit = []() { return g_ctx && g_ctx->plt_hook_commit(); };
        api->v1.connectCompanion = [](ZygiskModule *m) { return m->connectCompanion(); };
        api->v1.setOption = [](ZygiskModule *m, auto opt) { m->setOption(opt); };
    }
    if (api_version >= 2) {
        api->v2.getModuleDir = [](ZygiskModule *m) { return m->getModuleDir(); };
        api->v2.getFlags = [](auto) { return ZygiskModule::getFlags(); };
    }
    if (api_version >= 4) {
        api->v4.pltHookCommit = lsplt::CommitHook;
        api->v4.pltHookRegister = [](dev_t dev, ino_t inode, const char *symbol, void *fn, void **backup) {
            if (dev == 0 || inode == 0 || symbol == nullptr || fn == nullptr)
                return;
            lsplt::RegisterHook(dev, inode, symbol, fn, backup);
        };
        api->v4.exemptFd = [](int fd) { return g_ctx && g_ctx->exempt_fd(fd); };
    }

    return true;
}

void ZygiskContext::plt_hook_register(const char *regex, const char *symbol, void *fn, void **backup) {
    if (regex == nullptr || symbol == nullptr || fn == nullptr)
        return;
    regex_t re;
    if (regcomp(&re, regex, REG_NOSUB) != 0)
        return;
    mutex_guard lock(hook_info_lock);
    register_info.emplace_back(RegisterInfo{re, symbol, fn, backup});
}

void ZygiskContext::plt_hook_exclude(const char *regex, const char *symbol) {
    if (!regex) return;
    regex_t re;
    if (regcomp(&re, regex, REG_NOSUB) != 0)
        return;
    mutex_guard lock(hook_info_lock);
    ignore_info.emplace_back(IgnoreInfo{re, symbol ?: ""});
}

void ZygiskContext::plt_hook_process_regex() {
    if (register_info.empty())
        return;
    for (auto &map : lsplt::MapInfo::Scan()) {
        if (map.offset != 0 || !map.is_private || !(map.perms & PROT_READ)) continue;
        for (auto &reg: register_info) {
            if (regexec(&reg.regex, map.path.data(), 0, nullptr, 0) != 0)
                continue;
            bool ignored = false;
            for (auto &ign: ignore_info) {
                if (regexec(&ign.regex, map.path.data(), 0, nullptr, 0) != 0)
                    continue;
                if (ign.symbol.empty() || ign.symbol == reg.symbol) {
                    ignored = true;
                    break;
                }
            }
            if (!ignored) {
                lsplt::RegisterHook(map.dev, map.inode, reg.symbol, reg.callback, reg.backup);
            }
        }
    }
}

bool ZygiskContext::plt_hook_commit() {
    {
        mutex_guard lock(hook_info_lock);
        plt_hook_process_regex();
        register_info.clear();
        ignore_info.clear();
    }
    return lsplt::CommitHook();
}


bool ZygiskModule::valid() const {
    if (mod.api_version == nullptr)
        return false;
    switch (*mod.api_version) {
        case 4:
        case 3:
        case 2:
        case 1:
            return mod.v1->impl && mod.v1->preAppSpecialize && mod.v1->postAppSpecialize &&
                   mod.v1->preServerSpecialize && mod.v1->postServerSpecialize;
        default:
            return false;
    }
}

/* Zygisksu changed: Use own zygiskd */
int ZygiskModule::connectCompanion() const {
    return zygiskd::ConnectCompanion(id);
}

/* Zygisksu changed: Use own zygiskd */
int ZygiskModule::getModuleDir() const {
    return zygiskd::GetModuleDir(id);
}

void ZygiskModule::setOption(zygisk::Option opt) {
    if (g_ctx == nullptr)
        return;
    switch (opt) {
    case zygisk::FORCE_DENYLIST_UNMOUNT:
        g_ctx->flags[DO_REVERT_UNMOUNT] = true;
        break;
    case zygisk::DLCLOSE_MODULE_LIBRARY:
        unload = true;
        break;
    }
}

uint32_t ZygiskModule::getFlags() {
    return g_ctx ? (g_ctx->info_flags & ~PRIVATE_MASK) : 0;
}

// -----------------------------------------------------------------

int sigmask(int how, int signum) {
    sigset_t set;
    sigemptyset(&set);
    sigaddset(&set, signum);
    return sigprocmask(how, &set, nullptr);
}

void ZygiskContext::fork_pre() {
    // Do our own fork before loading any 3rd party code
    // First block SIGCHLD, unblock after original fork is done
    sigmask(SIG_BLOCK, SIGCHLD);
    pid = old_fork();
    if (pid != 0 || flags[SKIP_FD_SANITIZATION])
        return;

    // Record all open fds
    auto dir = xopen_dir("/proc/self/fd");
    for (dirent *entry; (entry = readdir(dir.get()));) {
        int fd = parse_int(entry->d_name);
        if (fd < 0 || fd >= MAX_FD_SIZE) {
            close(fd);
            continue;
        }
        allowed_fds[fd] = true;
    }
    // The dirfd should not be allowed
    allowed_fds[dirfd(dir.get())] = false;
}

void ZygiskContext::sanitize_fds() {
    if (flags[SKIP_FD_SANITIZATION])
        return;

    if (flags[APP_FORK_AND_SPECIALIZE]) {
        auto update_fd_array = [&](int off) -> jintArray {
            if (exempted_fds.empty())
                return nullptr;

            jintArray array = env->NewIntArray(static_cast<int>(off + exempted_fds.size()));
            if (array == nullptr)
                return nullptr;

            env->SetIntArrayRegion(array, off, static_cast<int>(exempted_fds.size()), exempted_fds.data());
            for (int fd : exempted_fds) {
                if (fd >= 0 && fd < MAX_FD_SIZE) {
                    allowed_fds[fd] = true;
                }
            }
            *args.app->fds_to_ignore = array;
            flags[SKIP_FD_SANITIZATION] = true;
            return array;
        };

        if (jintArray fdsToIgnore = *args.app->fds_to_ignore) {
            int *arr = env->GetIntArrayElements(fdsToIgnore, nullptr);
            int len = env->GetArrayLength(fdsToIgnore);
            for (int i = 0; i < len; ++i) {
                int fd = arr[i];
                if (fd >= 0 && fd < MAX_FD_SIZE) {
                    allowed_fds[fd] = true;
                }
            }
            if (jintArray newFdList = update_fd_array(len)) {
                env->SetIntArrayRegion(newFdList, 0, len, arr);
            }
            env->ReleaseIntArrayElements(fdsToIgnore, arr, JNI_ABORT);
        } else {
            update_fd_array(0);
        }
    }

    if (pid != 0)
        return;

    // Close all forbidden fds to prevent crashing
    auto dir = open_dir("/proc/self/fd");
    int dfd = dirfd(dir.get());
    for (dirent *entry; (entry = readdir(dir.get()));) {
        int fd = parse_int(entry->d_name);
        if ((fd < 0 || fd >= MAX_FD_SIZE || !allowed_fds[fd]) && fd != dfd) {
            close(fd);
        }
    }
}

void ZygiskContext::fork_post() {
    // Unblock SIGCHLD in case the original method didn't
    sigmask(SIG_UNBLOCK, SIGCHLD);
    g_ctx = nullptr;
}

/* Zygisksu changed: Load module fds */
void ZygiskContext::run_modules_pre() {
    auto ms = zygiskd::ReadModules();
    auto size = ms.size();
    for (size_t i = 0; i < size; i++) {
        auto& m = ms[i];
        if (void* handle = DlopenMem(m.memfd, RTLD_NOW);
            void* entry = handle ? dlsym(handle, "zygisk_module_entry") : nullptr) {
            modules.emplace_back(i, handle, entry);
        }
    }

    for (auto &m : modules) {
        m.onLoad(env);
        if (flags[APP_SPECIALIZE]) {
            m.preAppSpecialize(args.app);
        } else if (flags[SERVER_FORK_AND_SPECIALIZE]) {
            m.preServerSpecialize(args.server);
        }
    }
}

void ZygiskContext::run_modules_post() {
    flags[POST_SPECIALIZE] = true;
    for (const auto &m : modules) {
        if (flags[APP_SPECIALIZE]) {
            m.postAppSpecialize(args.app);
        } else if (flags[SERVER_FORK_AND_SPECIALIZE]) {
            m.postServerSpecialize(args.server);
        }
        m.tryUnload();
    }

    // Remove from SoList to avoid detection
    bool solist_res = SoList::Initialize();
    if (!solist_res) {
        LOGE("Failed to initialize SoList\n");
    } else {
        SoList::NullifySoName("jit-cache");
    }

    // Remap as well to avoid checking of /memfd:jit-cache
    for (auto &info : lsplt::MapInfo::Scan()) {
        if (strstr(info.path.c_str(), "jit-cache-zygisk"))
        {
            void *addr = (void *)info.start;
            size_t size = info.end - info.start;
            // MAP_SHARED should fix the suspicious mapping.
            void *copy = mmap(nullptr, size, PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0);
            if (copy == MAP_FAILED) {
                LOGE("Failed to mmap jit-cache-zygisk\n");
                continue;
            }

            if ((info.perms & PROT_READ) == 0) {
                mprotect(addr, size, PROT_READ);
            }
            memcpy(copy, addr, size);
            mremap(copy, size, size, MREMAP_MAYMOVE | MREMAP_FIXED, addr);
            mprotect(addr, size, info.perms);
        }
    }

    // Don't know if there's a header for things like this
    // so I just put it into a lambda
    auto generateRandomString = [](char *str, int length) {
        const char charset[] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
        srand(time(NULL));

        for (int i = 0; i < length; i++) {
            int key = rand() % (sizeof(charset) - 1);
            str[i] = charset[key];
        }

        str[length] = '\0';
    };

    // Randomize name of anonymous mappings
    // We don't run this in the previous loop because LSPosed might also add
    // mappings that are not related to /memfd:jit-zygisk-cache
    //
    // Since we changed to MAP_SHARED, I don't think this is still needed but let's
    // leave it here just in case.
    for (auto info : lsplt::MapInfo::Scan()) {
        // I had some problems with info.perms & PROT_EXEC so I had to change lsplt source a bit.
        // If that problem occurs here, do strchr(info.perms_str.c_str(), 'x') instead and add perms_str
        // to the lsplt MapInfo struct and set it to the raw perms string in Scan();
        if (info.perms & PROT_EXEC && info.path.empty()) {
            // Generate Random Name
            char randomString[11];
            generateRandomString(randomString, 10);
            LOGI("Randomized Memory map name: %s", randomString);

            // Memory address of random string
            uintptr_t strAddr = (uintptr_t)&randomString;

            // https://lore.kernel.org/lkml/1383170047-21074-2-git-send-email-ccross@android.com/
            prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, info.start, info.end - info.start, strAddr);
        }

        // Remap as MAP_SHARED
        if (info.perms & PROT_EXEC && info.dev == 0 && info.path.find("anon") != std::string::npos) {
            void *addr = reinterpret_cast<void *>(info.start);
            size_t size = info.end - info.start;
            void *copy = mmap(nullptr, size, PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0);
            if ((info.perms & PROT_READ) == 0) {
                mprotect(addr, size, PROT_READ);
            }
            memcpy(copy, addr, size);
            mremap(copy, size, size, MREMAP_MAYMOVE | MREMAP_FIXED, addr);
            mprotect(addr, size, info.perms);
        }
    }
}

/* Zygisksu changed: Load module fds */
void ZygiskContext::app_specialize_pre() {
    flags[APP_SPECIALIZE] = true;
    info_flags = zygiskd::GetProcessFlags(g_ctx->args.app->uid);

    if ((info_flags & PROCESS_ON_DENYLIST) == PROCESS_ON_DENYLIST) {
      flags[DO_REVERT_UNMOUNT] = true;
    }

    if ((info_flags & (PROCESS_IS_MANAGER | PROCESS_ROOT_IS_MAGISK)) == (PROCESS_IS_MANAGER | PROCESS_ROOT_IS_MAGISK)) {
        LOGI("Manager process detected. Notifying that Zygisk has been enabled.\n");

        setenv("ZYGISK_ENABLED", "1", 1);
    } else {
        run_modules_pre();
    }
}


void ZygiskContext::app_specialize_post() {
    run_modules_post();

    // Cleanups
    env->ReleaseStringUTFChars(args.app->nice_name, process);
    g_ctx = nullptr;
    logging::setfd(-1);
}

bool ZygiskContext::exempt_fd(int fd) {
    if (flags[POST_SPECIALIZE] || flags[SKIP_FD_SANITIZATION])
        return true;
    if (!flags[APP_FORK_AND_SPECIALIZE])
        return false;
    exempted_fds.push_back(fd);
    return true;
}

// -----------------------------------------------------------------

void ZygiskContext::nativeSpecializeAppProcess_pre() {
    process = env->GetStringUTFChars(args.app->nice_name, nullptr);
    LOGV("pre  specialize [%s]\n", process);
    // App specialize does not check FD
    flags[SKIP_FD_SANITIZATION] = true;
    app_specialize_pre();
}

void ZygiskContext::nativeSpecializeAppProcess_post() {
    LOGV("post specialize [%s]\n", process);
    app_specialize_post();
}

/* Zygisksu changed: No system_server status write back */
void ZygiskContext::nativeForkSystemServer_pre() {
    LOGV("pre  forkSystemServer\n");
    flags[SERVER_FORK_AND_SPECIALIZE] = true;

    fork_pre();
    if (pid != 0)
        return;

    run_modules_pre();
    zygiskd::SystemServerStarted();

    sanitize_fds();
}

void ZygiskContext::nativeForkSystemServer_post() {
    if (pid == 0) {
        LOGV("post forkSystemServer\n");
        run_modules_post();
    }
    fork_post();
}

void ZygiskContext::nativeForkAndSpecialize_pre() {
    process = env->GetStringUTFChars(args.app->nice_name, nullptr);
    LOGV("pre  forkAndSpecialize [%s]\n", process);

    flags[APP_FORK_AND_SPECIALIZE] = true;
    /* Zygisksu changed: No args.app->fds_to_ignore check since we are Android 10+ */
    if (logging::getfd() != -1) {
        exempted_fds.push_back(logging::getfd());
    }

    fork_pre();
    if (pid == 0) {
        app_specialize_pre();
    }
    sanitize_fds();
}

void ZygiskContext::nativeForkAndSpecialize_post() {
    if (pid == 0) {
        LOGV("post forkAndSpecialize [%s]\n", process);
        app_specialize_post();
    }
    fork_post();
}

ZygiskContext::~ZygiskContext() {
    // This global pointer points to a variable on the stack.
    // Set this to nullptr to prevent leaking local variable.
    // This also disables most plt hooked functions.
    g_ctx = nullptr;

    if (!is_child())
        return;

    should_unmap_zygisk = true;

    // Unhook JNI methods
    for (const auto &[clz, methods] : *jni_hook_list) {
        if (!methods.empty() && env->RegisterNatives(
                env->FindClass(clz.data()), methods.data(),
                static_cast<int>(methods.size())) != 0) {
            LOGE("Failed to restore JNI hook of class [%s]\n", clz.data());
            should_unmap_zygisk = false;
        }
    }
    delete jni_hook_list;
    jni_hook_list = nullptr;

    // Strip out all API function pointers
    for (auto &m : modules) {
        m.clearApi();
    }

    hook_unloader();
}

} // namespace

static bool hook_commit() {
    if (lsplt::CommitHook()) {
        return true;
    } else {
        LOGE("plt_hook failed\n");
        return false;
    }
}

static void hook_register(dev_t dev, ino_t inode, const char *symbol, void *new_func, void **old_func) {
    if (!lsplt::RegisterHook(dev, inode, symbol, new_func, old_func)) {
        LOGE("Failed to register plt_hook \"%s\"\n", symbol);
        return;
    }
    plt_hook_list->emplace_back(dev, inode, symbol, old_func);
}

#define PLT_HOOK_REGISTER_SYM(DEV, INODE, SYM, NAME) \
    hook_register(DEV, INODE, SYM, (void*) new_##NAME, (void **) &old_##NAME)

#define PLT_HOOK_REGISTER(DEV, INODE, NAME) \
    PLT_HOOK_REGISTER_SYM(DEV, INODE, #NAME, NAME)

void hook_functions() {
    default_new(plt_hook_list);
    default_new(jni_hook_list);

    ino_t android_runtime_inode = 0;
    dev_t android_runtime_dev = 0;
    /* TODO by ThePedroo: Implement injection via native bridge */
    // ino_t native_bridge_inode = 0;
    // dev_t native_bridge_dev = 0;

    for (auto &map : lsplt::MapInfo::Scan()) {
        if (map.path.ends_with("libandroid_runtime.so")) {
            android_runtime_inode = map.inode;
            android_runtime_dev = map.dev;

            break;
        }
    }

    PLT_HOOK_REGISTER(android_runtime_dev, android_runtime_inode, fork);
    PLT_HOOK_REGISTER(android_runtime_dev, android_runtime_inode, unshare);
    PLT_HOOK_REGISTER(android_runtime_dev, android_runtime_inode, strdup);
    PLT_HOOK_REGISTER_SYM(android_runtime_dev, android_runtime_inode, "__android_log_close", android_log_close);
    hook_commit();

    // Remove unhooked methods
    plt_hook_list->erase(
            std::remove_if(plt_hook_list->begin(), plt_hook_list->end(),
                           [](auto &t) { return *std::get<3>(t) == nullptr;}),
            plt_hook_list->end());
}

static void hook_unloader() {
    ino_t art_inode = 0;
    dev_t art_dev = 0;

    for (auto &map : lsplt::MapInfo::Scan()) {
        if (map.path.ends_with("/libart.so")) {
            art_inode = map.inode;
            art_dev = map.dev;
            break;
        }
    }

    PLT_HOOK_REGISTER(art_dev, art_inode, pthread_attr_destroy);
    hook_commit();
}

static void unhook_functions() {
    // Unhook plt_hook
    for (const auto &[dev, inode, sym, old_func] : *plt_hook_list) {
        if (!lsplt::RegisterHook(dev, inode, sym, *old_func, nullptr)) {
            LOGE("Failed to register plt_hook [%s]\n", sym);
        }
    }
    delete plt_hook_list;
    if (!hook_commit()) {
        LOGE("Failed to restore plt_hook\n");
        should_unmap_zygisk = false;
    }
}