Fully migrate Magisk to C++

native/jni/su/connect.cpp

@@ -19,7 +19,7 @@
 
 #define AM_PATH "/system/bin/app_process", "/system/bin", "com.android.commands.am.Am"
 
-static char *get_command(const struct su_request *to) {
+static const char *get_command(const struct su_request *to) {
 	if (to->command[0])
 		return to->command;
 	if (to->shell[0])
@@ -27,7 +27,7 @@ static char *get_command(const struct su_request *to) {
 	return DEFAULT_SHELL;
 }
 
-static void silent_run(char * const args[]) {
+static void silent_run(const char *args[]) {
 	if (fork_dont_care())
 		return;
 	int zero = open("/dev/zero", O_RDONLY | O_CLOEXEC);
@@ -36,7 +36,7 @@ static void silent_run(char * const args[]) {
 	xdup2(null, 1);
 	xdup2(null, 2);
 	setenv("CLASSPATH", "/system/framework/am.jar", 1);
-	execv(args[0], args);
+	execv(args[0], (char **) args);
 	PLOGE("exec am");
 	_exit(EXIT_FAILURE);
 }
@@ -71,7 +71,7 @@ void app_log(struct su_context *ctx) {
 	char policy[2];
 	sprintf(policy, "%d", ctx->info->access.policy);
 
-	char *cmd[] = {
+	const char *cmd[] = {
 		AM_PATH, "broadcast",
 		"-a", "android.intent.action.BOOT_COMPLETED",
 		"-p", DB_STR(ctx->info, SU_MANAGER),
@@ -84,7 +84,7 @@ void app_log(struct su_context *ctx) {
 		"--ei", "policy", policy,
 		"--es", "command", get_command(&ctx->req),
 		"--ez", "notify", ctx->info->access.notify ? "true" : "false",
-		NULL
+		nullptr
 	};
 	silent_run(cmd);
 }
@@ -101,7 +101,7 @@ void app_notify(struct su_context *ctx) {
 	char policy[2];
 	sprintf(policy, "%d", ctx->info->access.policy);
 
-	char *cmd[] = {
+	const char *cmd[] = {
 			AM_PATH, "broadcast",
 			"-a", "android.intent.action.BOOT_COMPLETED",
 			"-p", DB_STR(ctx->info, SU_MANAGER),
@@ -110,7 +110,7 @@ void app_notify(struct su_context *ctx) {
 			"--es", "action", "notify",
 			"--ei", "from.uid", fromUid,
 			"--ei", "policy", policy,
-			NULL
+			nullptr
 	};
 	silent_run(cmd);
 }
@@ -118,15 +118,15 @@ void app_notify(struct su_context *ctx) {
 void app_connect(const char *socket, struct su_info *info) {
 	char user[8];
 	setup_user(user, info);
-	char *cmd[] = {
+	const char *cmd[] = {
 		AM_PATH, "broadcast",
 		"-a", "android.intent.action.BOOT_COMPLETED",
 		"-p", DB_STR(info, SU_MANAGER),
 		"-f", "0x00000020",
 		"--user", user,
 		"--es", "action", "request",
-		"--es", "socket", (char *) socket,
-		NULL
+		"--es", "socket", socket,
+		nullptr
 	};
 	silent_run(cmd);
 }
@@ -135,4 +135,3 @@ void socket_send_request(int fd, struct su_info *info) {
 	write_key_token(fd, "uid", info->uid);
 	write_string_be(fd, "eof");
 }
-

native/jni/su/pts.cpp

@@ -9,7 +9,6 @@
  * helper functions to handle raw input mode and terminal window resizing
  */
 
-#define _GNU_SOURCE 
 #include <stdlib.h>
 #include <unistd.h>
 #include <fcntl.h>

native/jni/su/su.cpp

@@ -8,7 +8,6 @@
 /* su.c - The main function running in the daemon
  */
 
-#define _GNU_SOURCE
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -95,6 +94,12 @@ static void setup_sighandlers(void (*handler)(int)) {
 	}
 }
 
+// Default values
+su_req_base::su_req_base()
+		: uid(UID_ROOT), login(false), keepenv(false), mount_master(false) {}
+su_request::su_request()
+		: shell(DEFAULT_SHELL), command("") {}
+
 /*
  * Connect daemon, send argc, argv, cwd, pts slave
  */
@@ -112,15 +117,7 @@ int su_client_main(int argc, char *argv[]) {
 			{ NULL, 0, NULL, 0 },
 	};
 
-	struct su_request su_req = {
-		.uid = UID_ROOT,
-		.login = 0,
-		.keepenv = 0,
-		.mount_master = 0,
-		.shell = DEFAULT_SHELL,
-		.command = "",
-	};
-
+	su_request su_req;
 
 	for (int i = 0; i < argc; i++) {
 		// Replace -cn with -z, -mm with -M for supporting getopt_long
@@ -140,11 +137,11 @@ int su_client_main(int argc, char *argv[]) {
 				usage(EXIT_SUCCESS);
 				break;
 			case 'l':
-				su_req.login = 1;
+				su_req.login = true;
 				break;
 			case 'm':
 			case 'p':
-				su_req.keepenv = 1;
+				su_req.keepenv = true;
 				break;
 			case 's':
 				su_req.shell = optarg;
@@ -159,7 +156,7 @@ int su_client_main(int argc, char *argv[]) {
 				// Do nothing, placed here for legacy support :)
 				break;
 			case 'M':
-				su_req.mount_master = 1;
+				su_req.mount_master = true;
 				break;
 			default:
 				/* Bionic getopt_long doesn't terminate its error output by newline */
@@ -169,7 +166,7 @@ int su_client_main(int argc, char *argv[]) {
 	}
 
 	if (optind < argc && strcmp(argv[optind], "-") == 0) {
-		su_req.login = 1;
+		su_req.login = true;
 		optind++;
 	}
 	/* username or uid */
@@ -200,7 +197,7 @@ int su_client_main(int argc, char *argv[]) {
 	}
 
 	// Send su_request
-	xwrite(fd, &su_req, 4 * sizeof(unsigned));
+	xwrite(fd, &su_req, sizeof(su_req_base));
 	write_string(fd, su_req.shell);
 	write_string(fd, su_req.command);
 
@@ -242,4 +239,4 @@ int su_client_main(int argc, char *argv[]) {
 	close(fd);
 
 	return code;
-}
+}

native/jni/su/su.h

@@ -17,9 +17,9 @@
 #define ATTY_OUT    2
 #define ATTY_ERR    4
 
-struct su_info {
+class su_info {
+public:
 	unsigned uid;          /* Unique key to find su_info */
-	pthread_mutex_t lock;  /* Internal lock */
 	int count;             /* Just a count for debugging purpose */
 
 	/* These values should be guarded with internal lock */
@@ -31,19 +31,33 @@ struct su_info {
 	/* These should be guarded with global cache lock */
 	int ref;
 	int life;
+
+	su_info(unsigned uid);
+	~su_info();
+	void lock();
+	void unlock();
+
+private:
+	pthread_mutex_t _lock;  /* Internal lock */
 };
 
 #define DB_SET(i, e) (i)->dbs.v[e]
 #define DB_STR(i, e) (i)->str.s[e]
 
-struct su_request {
+struct su_req_base {
 	unsigned uid;
-	unsigned login;
-	unsigned keepenv;
-	unsigned mount_master;
-	char *shell;
-	char *command;
-};
+	bool login;
+	bool keepenv;
+	bool mount_master;
+protected:
+	su_req_base();
+} __attribute__((packed));
+
+struct su_request : public su_req_base {
+	const char *shell;
+	const char *command;
+	su_request();
+} __attribute__((packed));
 
 struct su_context {
 	struct su_info *info;

native/jni/su/su_daemon.cpp

@@ -1,8 +1,3 @@
-/* su_daemon.c - The entrypoint for su, connect to daemon and send correct info
- */
-
-#define _GNU_SOURCE
-
 #include <unistd.h>
 #include <pthread.h>
 #include <stdlib.h>
@@ -25,32 +20,45 @@
 #define TIMEOUT     3
 
 #define LOCK_CACHE()   pthread_mutex_lock(&cache_lock)
-#define LOCK_INFO()    pthread_mutex_lock(&info->lock)
 #define UNLOCK_CACHE() pthread_mutex_unlock(&cache_lock)
-#define UNLOCK_INFO()  pthread_mutex_unlock(&info->lock)
 
 static pthread_mutex_t cache_lock = PTHREAD_MUTEX_INITIALIZER;
-static struct su_info *cache;
+static su_info *cache;
+
+su_info::su_info(unsigned uid) :
+		uid(uid), access(DEFAULT_SU_ACCESS), _lock(PTHREAD_MUTEX_INITIALIZER),
+		count(0), ref(0), life(0), mgr_st({}) {}
+
+su_info::~su_info() {
+	pthread_mutex_destroy(&_lock);
+}
+
+void su_info::lock() {
+	pthread_mutex_lock(&_lock);
+}
+
+void su_info::unlock() {
+	pthread_mutex_unlock(&_lock);
+}
 
 static void *info_collector(void *node) {
-	struct su_info *info = node;
+	su_info *info = (su_info *) node;
 	while (1) {
 		sleep(1);
 		if (info->life) {
 			LOCK_CACHE();
 			if (--info->life == 0 && cache && info->uid == cache->uid)
-				cache = NULL;
+				cache = nullptr;
 			UNLOCK_CACHE();
 		}
 		if (!info->life && !info->ref) {
-			pthread_mutex_destroy(&info->lock);
-			free(info);
-			return NULL;
+			delete info;
+			return nullptr;
 		}
 	}
 }
 
-static void database_check(struct su_info *info) {
+static void database_check(su_info *info) {
 	int uid = info->uid;
 	sqlite3 *db = get_magiskdb();
 	if (db) {
@@ -84,20 +92,16 @@ static void database_check(struct su_info *info) {
 }
 
 static struct su_info *get_su_info(unsigned uid) {
-	struct su_info *info;
-	int cache_miss = 0;
+	su_info *info;
+	bool cache_miss = false;
 
 	LOCK_CACHE();
 
 	if (cache && cache->uid == uid) {
 		info = cache;
 	} else {
-		cache_miss = 1;
-		info = xcalloc(1, sizeof(*info));
-		info->uid = uid;
-		info->dbs = DEFAULT_DB_SETTINGS;
-		info->access = DEFAULT_SU_ACCESS;
-		pthread_mutex_init(&info->lock, NULL);
+		cache_miss = true;
+		info = new su_info(uid);
 		cache = info;
 	}
 
@@ -108,7 +112,7 @@ static struct su_info *get_su_info(unsigned uid) {
 	// Start a thread to maintain the cache
 	if (cache_miss) {
 		pthread_t thread;
-		xpthread_create(&thread, NULL, info_collector, info);
+		xpthread_create(&thread, nullptr, info_collector, info);
 		pthread_detach(thread);
 	}
 
@@ -117,7 +121,7 @@ static struct su_info *get_su_info(unsigned uid) {
 	LOGD("su: request from uid=[%d] (#%d)\n", info->uid, ++info->count);
 
 	// Lock before the policy is determined
-	LOCK_INFO();
+	info->lock();
 
 	if (info->access.policy == QUERY) {
 		//  Not cached, get data from database
@@ -173,14 +177,14 @@ static struct su_info *get_su_info(unsigned uid) {
 		} else {
 			socket_send_request(fd, info);
 			int ret = read_int_be(fd);
-			info->access.policy = ret < 0 ? DENY : ret;
+			info->access.policy = ret < 0 ? DENY : static_cast<policy_t>(ret);
 			close(fd);
 		}
 		close(sockfd);
 	}
 
 	// Unlock
-	UNLOCK_INFO();
+	info->unlock();
 
 	return info;
 }
@@ -224,7 +228,7 @@ static void set_identity(unsigned uid) {
 void su_daemon_handler(int client, struct ucred *credential) {
 	LOGD("su: request from client: %d\n", client);
 	
-	struct su_info *info = get_su_info(credential->uid);
+	su_info *info = get_su_info(credential->uid);
 
 	// Fail fast
 	if (info->access.policy == DENY && DB_STR(info, SU_MANAGER)[0] == '\0') {
@@ -289,7 +293,7 @@ void su_daemon_handler(int client, struct ucred *credential) {
 	}
 
 	// Read su_request
-	xxread(client, &ctx.req, 4 * sizeof(unsigned));
+	xxread(client, &ctx.req, sizeof(su_req_base));
 	ctx.req.shell = read_string(client);
 	ctx.req.command = read_string(client);
 
@@ -367,7 +371,7 @@ void su_daemon_handler(int client, struct ucred *credential) {
 		app_notify(&ctx);
 
 	if (info->access.policy == ALLOW) {
-		char* argv[] = { NULL, NULL, NULL, NULL };
+		const char *argv[] = { nullptr, nullptr, nullptr, nullptr };
 
 		argv[0] = ctx.req.login ? "-" : ctx.req.shell;
 
@@ -381,7 +385,7 @@ void su_daemon_handler(int client, struct ucred *credential) {
 		populate_environment(&ctx.req);
 		set_identity(ctx.req.uid);
 
-		execvp(ctx.req.shell, argv);
+		execvp(ctx.req.shell, (char **) argv);
 		fprintf(stderr, "Cannot execute %s: %s\n", ctx.req.shell, strerror(errno));
 		PLOGE("exec");
 		exit(EXIT_FAILURE);
@@ -391,4 +395,3 @@ void su_daemon_handler(int client, struct ucred *credential) {
 		exit(EXIT_FAILURE);
 	}
 }
-