br0kenpixel/Zygisk-Assistant
1
0
Fork 0
mirror of https://github.com/snake-4/Zygisk-Assistant.git synced 2025-09-06 06:37:02 +00:00
Code Issues Packages Projects Releases 1 Wiki Activity

Added root companion and logging macros

Browse Source
This commit is contained in:
snake-4
2024-04-16 17:49:25 +02:00
parent 2962997439
commit f200aa4561
6 changed files with 97 additions and 38 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
module/jni/include/logging.hpp
View File

@@ -6,10 +6,10 @@
#ifndef NDEBUG
static constexpr auto TAG = "ZygiskAssistant/JNI";
#define LOGD(...) __android_log_print(ANDROID_LOG_DEBUG, TAG, __VA_ARGS__)
#define LOGI(...) __android_log_print(ANDROID_LOG_INFO, TAG, __VA_ARGS__)
#define LOGW(...) __android_log_print(ANDROID_LOG_WARN, TAG, __VA_ARGS__)
#define LOGE(...) __android_log_print(ANDROID_LOG_ERROR, TAG, __VA_ARGS__)
#else
#define LOGD(...)
#define LOGI(...)
#define LOGW(...)
#define LOGE(...)
#endif

10
module/jni/include/utils.hpp
View File

@@ -1,10 +1,20 @@
#pragma once
#include <string>
#include <errno.h>
#include "logging.hpp"
#include "zygisk.hpp"
#define DCL_HOOK_FUNC(ret, func, ...) \
ret (*old_##func)(__VA_ARGS__) = nullptr; \
ret new_##func(__VA_ARGS__)
#define ASSERT_LOG(tag, expr) if(!(expr)) { \
LOGE("%s:%d Assertion %s failed. %d:%s", tag, __LINE__, #expr, errno, std::strerror(errno)); }
#define ASSERT_EXIT(tag, expr, ret) if(!(expr)) { \
LOGE("%s:%d Assertion %s failed. %d:%s", tag, __LINE__, #expr, errno, std::strerror(errno)); \
ret; }
bool switchMountNS(int pid);
int isUserAppUID(int uid);
bool hookPLTByName(zygisk::Api *api, const std::string &libName, const std::string &symbolName, void *hookFunc, void **origFunc);

80
module/jni/main.cpp
View File

@@ -1,6 +1,10 @@
#include <unistd.h>
#include <sched.h>
#include <sys/mount.h>
#include <grp.h>
#include <cstdint>
#include <functional>
#include "zygisk.hpp"
#include "logging.hpp"
@@ -13,6 +17,8 @@ using zygisk::ServerSpecializeArgs;
void doUnmount();
void doRemount();
static std::function<void()> callbackFunction = []() {};
/*
* [What's the purpose of this hook?]
* Calling unshare twice invalidates existing FD links, which fails Zygote sanity checks.
@@ -28,9 +34,7 @@ void doRemount();
*/
DCL_HOOK_FUNC(static int, unshare, int flags)
{
doUnmount();
doRemount();
callbackFunction();
// Do not allow CLONE_NEWNS.
flags &= ~(CLONE_NEWNS);
if (!flags)
@@ -68,27 +72,41 @@ public:
/*
* Read the comment above unshare hook.
*/
if (unshare(CLONE_NEWNS) == -1)
{
LOGE("unshare(CLONE_NEWNS) returned -1: %d (%s)", errno, strerror(errno));
return;
}
ASSERT_EXIT("preAppSpecialize", unshare(CLONE_NEWNS) != -1, return);
/*
* Mount the app mount namespace's root as MS_SLAVE, so every mount/umount from
* Zygote shared pre-specialization namespace is propagated to this one.
*/
if (mount("rootfs", "/", NULL, (MS_SLAVE | MS_REC), NULL) == -1)
{
LOGE("mount(\"rootfs\", \"/\", NULL, (MS_SLAVE | MS_REC), NULL) returned -1: %d (%s)", errno, strerror(errno));
return;
}
ASSERT_EXIT("preAppSpecialize", mount("rootfs", "/", NULL, (MS_SLAVE | MS_REC), NULL) != -1, return);
if (!hookPLTByName("libandroid_runtime.so", "unshare", new_unshare, &old_unshare))
ASSERT_EXIT("preAppSpecialize", hookPLTByName("libandroid_runtime.so", "unshare", new_unshare, &old_unshare), return);
ASSERT_LOG("preAppSpecialize", (companionFd = api->connectCompanion()) != -1);
callbackFunction = [fd = companionFd]()
{
LOGE("plt_hook_wrapper(\"libandroid_runtime.so\", \"unshare\", new_unshare, old_unshare) returned false");
return;
}
bool result = false;
if (fd != -1)
{
do
{
pid_t pid = getpid();
ASSERT_EXIT("invokeZygiskCompanion", write(fd, &pid, sizeof(pid)) == sizeof(pid), break);
ASSERT_EXIT("invokeZygiskCompanion", read(fd, &result, sizeof(result)) == sizeof(result), break);
} while (false);
close(fd);
}
if (result)
LOGD("Invoking the companion was successful.");
else
{
LOGW("Invoking the companion failed. Performing operations in Zygote context!");
doUnmount();
doRemount();
}
};
}
void preServerSpecialize(ServerSpecializeArgs *args) override
@@ -98,10 +116,8 @@ public:
void postAppSpecialize(const AppSpecializeArgs *args) override
{
if (old_unshare != nullptr && !hookPLTByName("libandroid_runtime.so", "unshare", old_unshare))
{
LOGE("plt_hook_wrapper(\"libandroid_runtime.so\", \"unshare\", old_unshare) returned false");
}
if (old_unshare != nullptr)
ASSERT_LOG("postAppSpecialize", hookPLTByName("libandroid_runtime.so", "unshare", old_unshare));
}
template <typename T>
@@ -111,8 +127,30 @@ public:
}
private:
int companionFd = -1;
Api *api;
JNIEnv *env;
};
void zygisk_companion_handler(int fd)
{
bool result = [&]() -> bool
{
pid_t pid;
ASSERT_EXIT("zygisk_companion_handler", read(fd, &pid, sizeof(pid)) == sizeof(pid), return false);
LOGD("zygisk_companion_handler received pid=%d", pid);
ASSERT_EXIT("zygisk_companion_handler", unshare(CLONE_NEWNS) != -1, return false);
ASSERT_EXIT("zygisk_companion_handler", switchMountNS(pid), return false);
doUnmount();
doRemount();
return true;
}();
ASSERT_LOG("zygisk_companion_handler", write(fd, &result, sizeof(result)) == sizeof(result));
}
REGISTER_ZYGISK_MODULE(ZygiskModule)
REGISTER_ZYGISK_COMPANION(zygisk_companion_handler)

9
module/jni/mount_parser.cpp
View File

@@ -7,6 +7,7 @@
#include "mount_parser.hpp"
#include "logging.hpp"
#include "utils.hpp"
mount_entry_t::mount_entry_t(::mntent *entry)
: fsname(entry->mnt_fsname), dir(entry->mnt_dir), type(entry->mnt_type), freq(entry->mnt_freq), passno(entry->mnt_passno)
@@ -25,12 +26,8 @@ std::vector<mount_entry_t> parseMountsFromPath(const char *path)
{
std::vector<mount_entry_t> result;
FILE *file = setmntent(path, "r");
if (file == NULL)
{
LOGE("setmntent(\"%s\", \"r\") returned NULL: %d (%s)", path, errno, strerror(errno));
return result;
}
FILE *file;
ASSERT_EXIT("parseMountsFromPath", (file = setmntent(path, "r")) != NULL, return result);
struct mntent *entry;
while ((entry = getmntent(file)) != NULL)

13
module/jni/unmount.cpp
View File

@@ -8,6 +8,7 @@
#include "logging.hpp"
#include "mount_parser.hpp"
#include "mountinfo_parser.hpp"
#include "utils.hpp"
constexpr std::array<const char *, 4> fsname_list = {"KSU", "APatch", "magisk", "worker"};
@@ -91,7 +92,7 @@ void doUnmount()
}
else
{
LOGE("umount2(\"%s\", MNT_DETACH) returned -1: %d (%s)", mountPoint.c_str(), errno, strerror(errno));
LOGW("umount2(\"%s\", MNT_DETACH) returned -1: %d (%s)", mountPoint.c_str(), errno, strerror(errno));
}
}
}
@@ -108,14 +109,8 @@ void doRemount()
// If errors=remount-ro, remount it with errors=continue
if (options.find("errors") != options.end() && options.at("errors") == "remount-ro")
{
if (mount(NULL, "/data", NULL, MS_REMOUNT, "errors=continue") == 0)
{
LOGD("mount(NULL, \"/data\", NULL, MS_REMOUNT, \"errors=continue\") returned 0");
}
else
{
LOGE("mount(NULL, \"/data\", NULL, MS_REMOUNT, \"errors=continue\") returned -1: %d (%s)", errno, strerror(errno));
}
LOGD("Trying to remount: /data");
ASSERT_LOG("doRemount", mount(NULL, "/data", NULL, MS_REMOUNT, "errors=continue") == 0);
}
}
}

19
module/jni/utils.cpp
View File

@@ -1,9 +1,14 @@
#include <string>
#include <format>
#include <unistd.h>
#include <sched.h>
#include <fcntl.h>
#include "map_parser.hpp"
#include "utils.hpp"
#include "android_filesystem_config.h"
#include "zygisk.hpp"
#include "logging.hpp"
bool hookPLTByName(zygisk::Api *api, const std::string &libName, const std::string &symbolName, void *hookFunc, void **origFunc)
{
@@ -27,3 +32,17 @@ int isUserAppUID(int uid)
return true;
return false;
}
bool switchMountNS(int pid)
{
std::string path = std::string("/proc/") + std::to_string(pid) + "/ns/mnt";
int ret, fd;
if ((fd = open(path.c_str(), O_RDONLY)) < 0)
{
return false;
}
ret = setns(fd, 0);
close(fd);
return ret == 0;
}