magiskinit code tidy-up

native/jni/Android.mk

@@ -62,6 +62,7 @@ LOCAL_SRC_FILES := \
 	init/rootdir.cpp \
 	init/getinfo.cpp \
 	init/twostage.cpp \
+	init/raw_data.cpp \
 	core/socket.cpp \
 	magiskpolicy/sepolicy.cpp \
 	magiskpolicy/magiskpolicy.cpp \

native/jni/init/getinfo.cpp

@@ -11,7 +11,8 @@
 
 using namespace std;
 
-static void parse_cmdline(const std::function<void (std::string_view, const char *)> &fn) {
+template<typename Func>
+static void parse_cmdline(Func fn) {
 	char cmdline[4096];
 	int fd = xopen("/proc/cmdline", O_RDONLY | O_CLOEXEC);
 	cmdline[read(fd, cmdline, sizeof(cmdline))] = '\0';
@@ -139,7 +140,7 @@ void load_kernel_info(cmdline *cmd) {
 	// Log to kernel
 	setup_klog();
 
-	parse_cmdline([&](auto key, auto value) -> void {
+	parse_cmdline([=](auto key, auto value) -> void {
 		if (key == "androidboot.slot_suffix") {
 			strcpy(cmd->slot, value);
 		} else if (key == "androidboot.slot") {

native/jni/init/init.cpp

@@ -20,64 +20,12 @@
 
 using namespace std;
 
+// Debug toggle
+#define ENABLE_TEST 0
+
 constexpr int (*init_applet_main[])(int, char *[]) =
 		{ magiskpolicy_main, magiskpolicy_main, nullptr };
 
-int data_holder::patch(str_pairs list) {
-	int count = 0;
-	for (uint8_t *p = buf, *eof = buf + sz; p < eof; ++p) {
-		for (auto [from, to] : list) {
-			if (memcmp(p, from.data(), from.length() + 1) == 0) {
-				LOGD("Replace [%s] -> [%s]\n", from.data(), to.data());
-				memset(p, 0, from.length());
-				memcpy(p, to.data(), to.length());
-				++count;
-				p += from.length();
-			}
-		}
-	}
-	return count;
-}
-
-bool data_holder::contains(string_view pattern) {
-	for (uint8_t *p = buf, *eof = buf + sz; p < eof; ++p) {
-		if (memcmp(p, pattern.data(), pattern.length() + 1) == 0)
-			return true;
-	}
-	return false;
-}
-
-void data_holder::consume(data_holder &other) {
-	buf = other.buf;
-	sz = other.sz;
-	other.buf = nullptr;
-	other.sz = 0;
-}
-
-auto_data<HEAP> raw_data::read(int fd) {
-	auto_data<HEAP> data;
-	fd_full_read(fd, data.buf, data.sz);
-	return data;
-}
-
-auto_data<HEAP> raw_data::read(const char *name) {
-	auto_data<HEAP> data;
-	full_read(name, data.buf, data.sz);
-	return data;
-}
-
-auto_data<MMAP> raw_data::mmap_rw(const char *name) {
-	auto_data<MMAP> data;
-	::mmap_rw(name, data.buf, data.sz);
-	return data;
-}
-
-auto_data<MMAP> raw_data::mmap_ro(const char *name) {
-	auto_data<MMAP> data;
-	::mmap_ro(name, data.buf, data.sz);
-	return data;
-}
-
 static bool unxz(int fd, const uint8_t *buf, size_t size) {
 	uint8_t out[8192];
 	xz_crc32_init();
@@ -123,7 +71,7 @@ static int dump_manager(const char *path, mode_t mode) {
 
 class RecoveryInit : public BaseInit {
 public:
-	RecoveryInit(char *argv[], cmdline *cmd) : BaseInit(argv, cmd) {};
+	RecoveryInit(char *argv[], cmdline *cmd) : BaseInit(argv, cmd) {}
 	void start() override {
 		LOGD("Ramdisk is recovery, abort\n");
 		rename("/.backup/init", "/init");
@@ -132,6 +80,7 @@ public:
 	}
 };
 
+#if ENABLE_TEST
 class TestInit : public BaseInit {
 public:
 	TestInit(char *argv[], cmdline *cmd) : BaseInit(argv, cmd) {};
@@ -140,7 +89,7 @@ public:
 	}
 };
 
-[[maybe_unused]] static int test_main(int argc, char *argv[]) {
+static int test_main(int argc, char *argv[]) {
 	// Log to console
 	cmdline_logging();
 	log_cb.ex = nop_ex;
@@ -172,6 +121,14 @@ public:
 
 	return 1;
 }
+#endif // ENABLE_TEST
+
+static int magisk_proxy_main(int argc, char *argv[]) {
+	setup_klog();
+	auto init = make_unique<MagiskProxy>(argv);
+	init->start();
+	return 1;
+}
 
 int main(int argc, char *argv[]) {
 	umask(0);
@@ -184,7 +141,7 @@ int main(int argc, char *argv[]) {
 			return (*init_applet_main[i])(argc, argv);
 	}
 
-#if 0
+#if ENABLE_TEST
 	if (getenv("INIT_TEST") != nullptr)
 		return test_main(argc, argv);
 #endif

native/jni/init/init.hpp

@@ -7,6 +7,8 @@
 
 #include <utils.hpp>
 
+#include "raw_data.hpp"
+
 struct cmdline {
 	bool skip_initramfs;
 	bool force_normal_boot;
@@ -17,35 +19,6 @@ struct cmdline {
 	char hardware_plat[32];
 };
 
-struct data_holder {
-	uint8_t *buf = nullptr;
-	size_t sz = 0;
-	using str_pairs = std::initializer_list<std::pair<std::string_view, std::string_view>>;
-	int patch(str_pairs list);
-	bool contains(std::string_view pattern);
-protected:
-	void consume(data_holder &other);
-};
-
-enum data_type { HEAP, MMAP };
-template <data_type T>
-struct auto_data : public data_holder {
-	auto_data<T>() = default;
-	auto_data<T>(const auto_data&) = delete;
-	auto_data<T>(auto_data<T> &&other) { consume(other); }
-	~auto_data<T>() {}
-	auto_data<T>& operator=(auto_data<T> &&other) { consume(other); return *this; }
-};
-template <> inline auto_data<MMAP>::~auto_data<MMAP>() { if (buf) munmap(buf, sz); }
-template <> inline auto_data<HEAP>::~auto_data<HEAP>() { free(buf); }
-
-namespace raw_data {
-	auto_data<HEAP> read(const char *name);
-	auto_data<HEAP> read(int fd);
-	auto_data<MMAP> mmap_rw(const char *name);
-	auto_data<MMAP> mmap_ro(const char *name);
-}
-
 struct fstab_entry {
 	std::string dev;
 	std::string mnt_point;
@@ -55,7 +28,7 @@ struct fstab_entry {
 
 	fstab_entry() = default;
 	fstab_entry(const fstab_entry &) = delete;
-	fstab_entry(fstab_entry &&o) = default;
+	fstab_entry(fstab_entry &&) = default;
 	void to_file(FILE *fp);
 };
 
@@ -65,9 +38,7 @@ struct fstab_entry {
 void load_kernel_info(cmdline *cmd);
 bool check_two_stage();
 int dump_magisk(const char *path, mode_t mode);
-int magisk_proxy_main(int argc, char *argv[]);
 void setup_klog();
-void setup_tmp(const char *path, const data_holder &self, const data_holder &config);
 
 /***************
  * Base classes
@@ -85,31 +56,32 @@ protected:
 		exit(1);
 	}
 	virtual void cleanup();
+	void read_dt_fstab(std::vector<fstab_entry> &fstab);
 public:
 	BaseInit(char *argv[], cmdline *cmd) :
 	cmd(cmd), argv(argv), mount_list{"/sys", "/proc"} {}
 	virtual ~BaseInit() = default;
 	virtual void start() = 0;
-	void read_dt_fstab(std::vector<fstab_entry> &fstab);
-	void dt_early_mount();
 };
 
 class MagiskInit : public BaseInit {
 protected:
 	auto_data<HEAP> self;
+	auto_data<HEAP> config;
 	std::string persist_dir;
 
-	virtual void early_mount() = 0;
+	void mount_with_dt();
 	bool patch_sepolicy(const char *file);
+	void setup_tmp(const char *path);
 public:
 	MagiskInit(char *argv[], cmdline *cmd) : BaseInit(argv, cmd) {}
 };
 
 class SARBase : public MagiskInit {
 protected:
-	auto_data<HEAP> config;
 	std::vector<raw_file> overlays;
 
+	virtual void early_mount() = 0;
 	void backup_files();
 	void patch_rootdir();
 	void mount_system_root();
@@ -129,7 +101,6 @@ public:
 class FirstStageInit : public BaseInit {
 private:
 	void prepare();
-
 public:
 	FirstStageInit(char *argv[], cmdline *cmd) : BaseInit(argv, cmd) {
 		LOGD("%s\n", __FUNCTION__);
@@ -140,22 +111,6 @@ public:
 	}
 };
 
-class SARFirstStageInit : public SARBase {
-private:
-	void prepare();
-protected:
-	void early_mount() override;
-public:
-	SARFirstStageInit(char *argv[], cmdline *cmd) : SARBase(argv, cmd) {
-		LOGD("%s\n", __FUNCTION__);
-	};
-	void start() override {
-		early_mount();
-		prepare();
-		exec_init();
-	}
-};
-
 class SecondStageInit : public SARBase {
 protected:
 	void early_mount() override;
@@ -179,6 +134,24 @@ public:
 	};
 };
 
+// Special case for legacy SAR on Android 10+
+// Should be followed by normal 2SI SecondStageInit
+class SARFirstStageInit : public SARBase {
+private:
+	void prepare();
+protected:
+	void early_mount() override;
+public:
+	SARFirstStageInit(char *argv[], cmdline *cmd) : SARBase(argv, cmd) {
+		LOGD("%s\n", __FUNCTION__);
+	};
+	void start() override {
+		early_mount();
+		prepare();
+		exec_init();
+	}
+};
+
 /************
  * Initramfs
  ************/
@@ -186,8 +159,7 @@ public:
 class RootFSInit : public MagiskInit {
 private:
 	void setup_rootfs();
-protected:
-	void early_mount() override;
+	void early_mount();
 public:
 	RootFSInit(char *argv[], cmdline *cmd) : MagiskInit(argv, cmd) {
 		LOGD("%s\n", __FUNCTION__);
@@ -199,3 +171,11 @@ public:
 		exec_init();
 	}
 };
+
+class MagiskProxy : public MagiskInit {
+public:
+	explicit MagiskProxy(char *argv[]) : MagiskInit(argv, nullptr) {
+		LOGD("%s\n", __FUNCTION__);
+	}
+	void start() override;
+};

native/jni/init/mount.cpp

@@ -151,7 +151,7 @@ void BaseInit::read_dt_fstab(vector<fstab_entry> &fstab) {
 	}
 }
 
-void BaseInit::dt_early_mount() {
+void MagiskInit::mount_with_dt() {
 	vector<fstab_entry> fstab;
 	read_dt_fstab(fstab);
 	for (const auto &entry : fstab) {
@@ -224,7 +224,7 @@ void RootFSInit::early_mount() {
 	LOGD("Restoring /init\n");
 	rename("/.backup/init", "/init");
 
-	dt_early_mount();
+	mount_with_dt();
 
 	xmkdir("/dev/mnt", 0755);
 	mount_persist("/dev/block", "/dev/mnt");
@@ -272,7 +272,7 @@ void SARInit::early_mount() {
 	mount_system_root();
 	switch_root("/system_root");
 
-	dt_early_mount();
+	mount_with_dt();
 }
 
 void SARFirstStageInit::early_mount() {
@@ -308,7 +308,7 @@ static void patch_socket_name(const char *path) {
 	bin.patch({ make_pair(MAIN_SOCKET, rstr) });
 }
 
-void setup_tmp(const char *path, const data_holder &self, const data_holder &config) {
+void MagiskInit::setup_tmp(const char *path) {
 	LOGD("Setup Magisk tmp at %s\n", path);
 	xmount("tmpfs", path, "tmpfs", 0, "mode=755");
 

native/jni/init/raw_data.cpp

@@ -0,0 +1,58 @@
+#include "raw_data.hpp"
+
+using namespace std;
+
+int data_holder::patch(str_pairs list) {
+	int count = 0;
+	for (uint8_t *p = buf, *eof = buf + sz; p < eof; ++p) {
+		for (auto [from, to] : list) {
+			if (memcmp(p, from.data(), from.length() + 1) == 0) {
+				LOGD("Replace [%s] -> [%s]\n", from.data(), to.data());
+				memset(p, 0, from.length());
+				memcpy(p, to.data(), to.length());
+				++count;
+				p += from.length();
+			}
+		}
+	}
+	return count;
+}
+
+bool data_holder::contains(string_view pattern) {
+	for (uint8_t *p = buf, *eof = buf + sz; p < eof; ++p) {
+		if (memcmp(p, pattern.data(), pattern.length() + 1) == 0)
+			return true;
+	}
+	return false;
+}
+
+void data_holder::consume(data_holder &other) {
+	buf = other.buf;
+	sz = other.sz;
+	other.buf = nullptr;
+	other.sz = 0;
+}
+
+auto_data<HEAP> raw_data::read(int fd) {
+	auto_data<HEAP> data;
+	fd_full_read(fd, data.buf, data.sz);
+	return data;
+}
+
+auto_data<HEAP> raw_data::read(const char *name) {
+	auto_data<HEAP> data;
+	full_read(name, data.buf, data.sz);
+	return data;
+}
+
+auto_data<MMAP> raw_data::mmap_rw(const char *name) {
+	auto_data<MMAP> data;
+	::mmap_rw(name, data.buf, data.sz);
+	return data;
+}
+
+auto_data<MMAP> raw_data::mmap_ro(const char *name) {
+	auto_data<MMAP> data;
+	::mmap_ro(name, data.buf, data.sz);
+	return data;
+}

native/jni/init/raw_data.hpp

@@ -0,0 +1,32 @@
+#pragma once
+
+#include <utils.hpp>
+
+struct data_holder {
+	uint8_t *buf = nullptr;
+	size_t sz = 0;
+	using str_pairs = std::initializer_list<std::pair<std::string_view, std::string_view>>;
+	int patch(str_pairs list);
+	bool contains(std::string_view pattern);
+protected:
+	void consume(data_holder &other);
+};
+
+enum data_type { HEAP, MMAP };
+template <data_type T>
+struct auto_data : public data_holder {
+	auto_data<T>() = default;
+	auto_data<T>(const auto_data&) = delete;
+	auto_data<T>(auto_data<T> &&other) { consume(other); }
+	~auto_data<T>() {}
+	auto_data<T>& operator=(auto_data<T> &&other) { consume(other); return *this; }
+};
+template <> inline auto_data<MMAP>::~auto_data<MMAP>() { if (buf) munmap(buf, sz); }
+template <> inline auto_data<HEAP>::~auto_data<HEAP>() { free(buf); }
+
+namespace raw_data {
+	auto_data<HEAP> read(const char *name);
+	auto_data<HEAP> read(int fd);
+	auto_data<MMAP> mmap_rw(const char *name);
+	auto_data<MMAP> mmap_ro(const char *name);
+}

native/jni/init/rootdir.cpp

@@ -228,7 +228,7 @@ void SARBase::patch_rootdir() {
 		sepol = "/dev/.se";
 	}
 
-	setup_tmp(tmp_dir, self, config);
+	setup_tmp(tmp_dir);
 	persist_dir = MIRRDIR "/persist/magisk";
 
 	chdir(tmp_dir);
@@ -317,24 +317,20 @@ void SARBase::patch_rootdir() {
 	chdir("/");
 }
 
-int magisk_proxy_main(int argc, char *argv[]) {
-	setup_klog();
-
-	auto self = raw_data::read("/sbin/magisk");
-	auto config = raw_data::read("/.backup/.magisk");
+void MagiskProxy::start() {
+	self = raw_data::read("/sbin/magisk");
+	config = raw_data::read("/.backup/.magisk");
 
 	xmount(nullptr, "/", nullptr, MS_REMOUNT, nullptr);
 
 	unlink("/sbin/magisk");
 	rm_rf("/.backup");
 
-	setup_tmp("/sbin", self, config);
+	setup_tmp("/sbin");
 
 	// Create symlinks pointing back to /root
 	recreate_sbin("/root", false);
 
 	setenv("REMOUNT_ROOT", "1", 1);
 	execv("/sbin/magisk", argv);
-
-	return 1;
 }