Magisk/jni/daemon/magisk.c

/* main.c - The multicall entry point
 */

#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>

#include "utils.h"
#include "magisk.h"
#include "daemon.h"

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 };

int create_links(const char *bin, const char *path) {
	char self[PATH_MAX], linkpath[PATH_MAX];
	if (bin == NULL) {
		xreadlink("/proc/self/exe", self, sizeof(self));
		bin = self;
	}
	int ret = 0;
	for (int i = 0; applet[i]; ++i) {
		snprintf(linkpath, sizeof(linkpath), "%s/%s", path, applet[i]);
		unlink(linkpath);
		ret |= symlink(bin, linkpath);
	}
	return ret;
}

// Global error hander function
// Should be changed each thread/process
__thread void (*err_handler)(void);

static void usage() {
	fprintf(stderr,
		"Magisk v" xstr(MAGISK_VERSION) "(" xstr(MAGISK_VER_CODE) ") (by topjohnwu) multi-call binary\n"
		"\n"
		"Usage: %s [applet [arguments]...]\n"
		"   or: %s [options]...\n"
		"\n"
		"Options:\n"
		"   -c                        print current binary version\n"
		"   -v                        print running daemon version\n"
		"   -V                        print running daemon version code\n"
		"   --list                    list all availible applets\n"
        "   --install [SOURCE] DIR    symlink all applets to DIR. SOURCE is optional\n"
		"   --createimg IMG SIZE      create ext4 image. SIZE is interpreted in MB\n"
		"   --imgsize IMG             report ext4 image used/total size\n"
		"   --resizeimg IMG SIZE      resize ext4 image. SIZE is interpreted in MB\n"
		"   --mountimg IMG PATH       mount IMG to PATH and prints the loop device\n"
		"   --umountimg PATH LOOP     unmount PATH and delete LOOP device\n"
		"   --[init service]          start init service\n"
		"   --unlock-blocks           set BLKROSET flag to OFF for all block devices\n"
		"\n"
		"Supported init services:\n"
		"   daemon post-fs, post-fs-data, service\n"
		"\n"
		"Supported applets:\n"
	, argv0, argv0);

	for (int i = 0; applet[i]; ++i)
		fprintf(stderr, i ? ", %s" : "    %s", applet[i]);
	fprintf(stderr, "\n\n");
	exit(1);
}

int main(int argc, char *argv[]) {
	argv0 = argv[0];
	// Exit the whole app if error occurs by default
	err_handler = exit_proc;
	char * arg = strrchr(argv[0], '/');
	if (arg) ++arg;
	else arg = argv[0];
	if (strcmp(arg, "magisk") == 0) {
		if (argc < 2) usage();
		if (strcmp(argv[1], "-c") == 0) {
			printf("%s\n", MAGISK_VER_STR);
			return 0;
		} else if (strcmp(argv[1], "-v") == 0) {
			int fd = connect_daemon();
			write_int(fd, CHECK_VERSION);
			char *v = read_string(fd);
			printf("%s\n", v);
			free(v);
			return 0;
		} else if (strcmp(argv[1], "-V") == 0) {
			int fd = connect_daemon();
			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], "--createimg") == 0) {
			if (argc < 4) usage();
			int size;
			sscanf(argv[3], "%d", &size);
			return create_img(argv[2], size);
		} else if (strcmp(argv[1], "--imgsize") == 0) {
			if (argc < 3) usage();
			int used, total;
			if (get_img_size(argv[2], &used, &total)) {
				fprintf(stderr, "Cannot check %s size\n", argv[2]);
				return 1;
			}
			printf("%d %d\n", used, total);
			return 0;
		} else if (strcmp(argv[1], "--resizeimg") == 0) {
			if (argc < 4) usage();
			int used, total, size;
			sscanf(argv[3], "%d", &size);
			if (get_img_size(argv[2], &used, &total)) {
				fprintf(stderr, "Cannot check %s size\n", argv[2]);
				return 1;
			}
			if (size <= used) {
				fprintf(stderr, "Cannot resize smaller than %dM\n", used);
				return 1;
			}
			return resize_img(argv[2], size);
		} else if (strcmp(argv[1], "--mountimg") == 0) {
			if (argc < 4) usage();
			char *loop = mount_image(argv[2], argv[3]);
			if (loop == NULL) {
				fprintf(stderr, "Cannot mount image!\n");
				return 1;
			} else {
				printf("%s\n", loop);
				free(loop);
				return 0;
			}
		} else if (strcmp(argv[1], "--umountimg") == 0) {
			if (argc < 4) usage();
			umount_image(argv[2], argv[3]);
			return 0;
		} else if (strcmp(argv[1], "--unlock-blocks") == 0) {
			unlock_blocks();
			return 0;
		} else if (strcmp(argv[1], "--daemon") == 0) {
			// Start daemon, this process won't return
			start_daemon();
		} else if (strcmp(argv[1], "--post-fs") == 0) {
			int fd = connect_daemon();
			write_int(fd, POST_FS);
			return read_int(fd);
		} else if (strcmp(argv[1], "--post-fs-data") == 0) {
			int fd = connect_daemon();
			write_int(fd, POST_FS_DATA);
			return read_int(fd);
		} else if (strcmp(argv[1], "--service") == 0) {
			int fd = connect_daemon();
			write_int(fd, LATE_START);
			return read_int(fd);
		} else {
			// It's calling applets
			--argc;
			++argv;
			arg = argv[0];
		}
	}

	// Applets
	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;
}