Update main function

jni/magisk.h

@@ -46,6 +46,9 @@ static inline void stub(const char *fmt, ...) {}
 
 extern char *argv0;     /* For changing process name */
 
+extern char *applet[];
+extern int (*applet_main[]) (int, char *[]);
+
 // Multi-call entrypoints
 int magiskhide_main(int argc, char *argv[]);
 int magiskpolicy_main(int argc, char *argv[]);

jni/main.c

@@ -2,6 +2,7 @@
  */
 
 #include <stdlib.h>
+#include <stdio.h>
 
 #include "utils.h"
 #include "magisk.h"
@@ -9,10 +10,44 @@
 
 char *argv0;
 
+char *applet[] =
+	{ "su", "resetprop", "magiskpolicy", "supolicy", "magiskhide", NULL };
+
+int (*applet_main[]) (int, char *[]) =
+	{ su_client_main, resetprop_main, magiskpolicy_main, magiskpolicy_main, magiskhide_main, NULL };
+
 // Global error hander function
 // Should be changed each thread/process
 __thread void (*err_handler)(void);
 
+static void usage() {
+	fprintf(stderr,
+		"Magisk v" xstr(VERSION) " multi-call binary\n"
+		"\n"
+		"Usage: %s [applet [arguments]...]\n"
+		"   or: %s --install [SOURCE] <DIR> \n"
+		"   or: %s --list\n"
+		"   or: %s --[boot stage]    start boot stage service\n"
+		"   or: %s [options]\n"
+		"   or: applet [arguments]...\n"
+		"\n"
+		"Supported boot stages:\n"
+		"       post-fs, post-fs-data, service\n"
+		"\n"
+		"Options:\n"
+		"       -v            print client and daemon version\n"
+		"       -V            print daemon version code\n"
+		"\n"
+		"Supported applets:\n"
+	, argv0, argv0, argv0, argv0, argv0);
+
+	for (int i = 0; applet[i]; ++i) {
+		fprintf(stderr, i ? ", %s" : "       %s", applet[i]);
+	}
+	fprintf(stderr, "\n");
+	exit(1);
+}
+
 int main(int argc, char *argv[]) {
 	argv0 = argv[0];
 	// Exit the whole app if error occurs by default
@@ -20,6 +55,7 @@ int main(int argc, char *argv[]) {
 	char * arg = strrchr(argv[0], '/');
 	if (arg) ++arg;
 	if (strcmp(arg, "magisk") == 0) {
+		if (argc < 2) usage();
 		if (strcmp(argv[1], "-v") == 0) {
 			printf("Client: %s\n", VERSION_STR);
 			int fd = connect_daemon();
@@ -33,6 +69,14 @@ int main(int argc, char *argv[]) {
 			write_int(fd, CHECK_VERSION_CODE);
 			printf("%d\n", read_int(fd));
 			return 0;
+		} else if (strcmp(argv[1], "--install") == 0) {
+			if (argc < 3) usage();
+			if (argc == 3) return create_links(NULL, argv[2]);
+			else return create_links(argv[2], argv[3]);
+		} else if (strcmp(argv[1], "--list") == 0) {
+			for (int i = 0; applet[i]; ++i)
+				printf("%s\n", applet[i]);
+			return 0;
 		} else if (strcmp(argv[1], "--post-fs") == 0) {
 			// TODO: post-fs mode
 			return 0;
@@ -42,9 +86,6 @@ int main(int argc, char *argv[]) {
 		} else if (strcmp(argv[1], "--service") == 0) {
 			// TODO: late_start service mode
 			return 0;
-		} else if (strcmp(argv[1], "--install") == 0) {
-			// TODO: Install symlinks
-			return 0;
 		} else if (strcmp(argv[1], "--test") == 0) {
 			// Temporary testing entry
 			int fd = connect_daemon();
@@ -60,16 +101,11 @@ int main(int argc, char *argv[]) {
 	}
 
 	// Applets
-	if (strcmp(arg, "su") == 0) {
-		return su_client_main(argc, argv);
-	} else if (strcmp(arg, "magiskpolicy") == 0) {
-		return magiskpolicy_main(argc, argv);
-	} else if (strcmp(arg, "resetprop") == 0) {
-		return resetprop_main(argc, argv);
-	} else if (strcmp(arg, "magiskhide") == 0) {
-		return magiskhide_main(argc, argv);
-	} else {
-		fprintf(stderr, "Applet \'%s\' not found\n", arg);
+	for (int i = 0; applet[i]; ++i) {
+		if (strcmp(arg, applet[i]) == 0)
+			return (*applet_main[i])(argc, argv);
 	}
+
+	fprintf(stderr, "%s: applet not found\n", arg);
 	return 1;
 }

jni/utils/misc.c

@@ -135,3 +135,18 @@ void ps_filter_proc_name(const char *pattern, void (*func)(int)) {
 	ps_filter_pattern = ((pattern == NULL) ? "" : pattern);
 	ps(proc_name_filter);
 }
+
+int create_links(const char *bin, const char *path) {
+	char self[PATH_MAX], linkpath[PATH_MAX];
+	if (bin == NULL) {
+		xreadlink("/proc/self/exe", self, PATH_MAX);
+		bin = self;
+	}
+	int ret = 0;
+	for (int i = 0; applet[i]; ++i) {
+		snprintf(linkpath, PATH_MAX, "%s/%s", path, applet[i]);
+		unlink(linkpath);
+		ret |= symlink(bin, linkpath);
+	}
+	return ret;
+}

jni/utils/utils.h

@@ -46,6 +46,8 @@ int xpthread_create(pthread_t *thread, const pthread_attr_t *attr,
 int xsocketpair(int domain, int type, int protocol, int sv[2]);
 int xstat(const char *pathname, struct stat *buf);
 int xdup2(int oldfd, int newfd);
+ssize_t xreadlink(const char *pathname, char *buf, size_t bufsiz);
+int xsymlink(const char *target, const char *linkpath);
 
 // misc.c
 
@@ -58,5 +60,6 @@ int isNum(const char *s);
 ssize_t fdreadline(int fd, char *buf, size_t size);
 void ps(void (*func)(int));
 void ps_filter_proc_name(const char *filter, void (*func)(int));
+int create_links(const char *bin, const char *path);
 
 #endif

jni/utils/xwrap.c

@@ -226,4 +226,22 @@ int xdup2(int oldfd, int newfd) {
 	return ret;
 }
 
+ssize_t xreadlink(const char *pathname, char *buf, size_t bufsiz) {
+	ssize_t ret = readlink(pathname, buf, bufsiz);
+	if (ret == -1) {
+		PLOGE("readlink %s", pathname);
+	} else {
+		buf[ret] = '\0';
+	}
+	return ret;
+}
+
+int xsymlink(const char *target, const char *linkpath) {
+	int ret = symlink(target, linkpath);
+	if (ret == -1) {
+		PLOGE("symlink %s->%s", target, linkpath);
+	}
+	return ret;
+}
+