Add ext4 img helper commands

jni/daemon/bootstages.c

@@ -86,38 +86,8 @@ static void umount_image(const char *target, const char *device) {
 	close(fd);
 }
 
-static int get_img_size(const char *img, int *used, int *total) {
-	char buffer[PATH_MAX];
-	snprintf(buffer, sizeof(buffer), "e2fsck -n %s 2>/dev/null | tail -n 1", img);
-	char *const command[] = { "sh", "-c", buffer, NULL };
-	int pid, fd;
-	pid = run_command(&fd, "/system/bin/sh", command);
-	fdgets(buffer, sizeof(buffer), fd);
-	close(fd);
-	if (pid == -1)
-		return 1;
-	waitpid(pid, NULL, 0);
-	char *tok;
-	tok = strtok(buffer, ",");
-	while(tok != NULL) {
-		if (strstr(tok, "blocks"))
-			break;
-		tok = strtok(NULL, ",");
-	}
-	sscanf(tok, "%d/%d", used, total);
-	*used = *used / 256 + 1;
-	*total /= 256;
-	return 0;
-}
-
 #define round_size(a) ((((a) / 32) + 2) * 32)
 
-static int resize_img(const char *img, int size) {
-	LOGI("resize %s to %dM\n", img, size);
-	snprintf(buf, PATH_MAX, "e2fsck -yf %s; resize2fs %s %dM;", img, img, size);
-	return system(buf);
-}
-
 static int merge_img(const char *source, const char *target) {
 	if (access(source, F_OK) == -1)
 		return 0;
@@ -544,6 +514,9 @@ void post_fs_data(int client) {
 	if (merge_img("/data/magisk_merge.img", MAINIMG))
 		goto unblock;
 
+	if (access(MAINIMG, F_OK) == -1 && create_img(MAINIMG, 64))
+		goto unblock;
+
 	LOGI("* Mounting " MAINIMG "\n");
 	// Mounting magisk image
 	char *magiskloop = mount_image(MAINIMG, MOUNTPOINT);

jni/main.c

@@ -27,7 +27,13 @@ static void usage() {
 		"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 --createimg <PATH> <SIZE>\n"
+		"       create ext4 image, SIZE is interpreted in MB\n"
+		"   or: %s --imgsize <PATH>\n"
+		"   or: %s --resizeimg <PATH> <SIZE>\n"
+		"       SIZE is interpreted in MB\n"
+		"   or: %s --[boot stage]\n"
+		"       start boot stage service\n"
 		"   or: %s [options]\n"
 		"   or: applet [arguments]...\n"
 		"\n"
@@ -40,7 +46,7 @@ static void usage() {
 		"       -V            print daemon version code\n"
 		"\n"
 		"Supported applets:\n"
-	, argv0, argv0, argv0, argv0, argv0);
+	, argv0, argv0, argv0, argv0, argv0, argv0, argv0, argv0);
 
 	for (int i = 0; applet[i]; ++i) {
 		fprintf(stderr, i ? ", %s" : "       %s", applet[i]);
@@ -81,6 +87,33 @@ int main(int argc, char *argv[]) {
 			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("Used: %dM\tTotal: %dM\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], "--post-fs") == 0) {
 			int fd = connect_daemon();
 			write_int(fd, POST_FS);

jni/utils/misc.c

@@ -397,3 +397,53 @@ void get_client_cred(int fd, struct ucred *cred) {
 	if(getsockopt(fd, SOL_SOCKET, SO_PEERCRED, cred, &ucred_length))
 		PLOGE("getsockopt");
 }
+
+int create_img(const char *img, int size) {
+	unlink(img);
+	LOGI("Create %s with size %dM\n", img, size);
+	// Create a temp file with the file contexts
+	char file_contexts[] = "/magisk(/.*)? u:object_r:system_file:s0\n";
+	int fd = xopen("/dev/file_contexts_image", O_WRONLY | O_CREAT | O_TRUNC, 0644);
+	xwrite(fd, file_contexts, sizeof(file_contexts));
+	close(fd);
+
+	char command[PATH_MAX];
+	snprintf(command, sizeof(command),
+		"make_ext4fs -l %dM -a /magisk -S /dev/file_contexts_image %s", size, img);
+	int ret = system(command);
+	unlink("/dev/file_contexts_image");
+	return ret;
+}
+
+int get_img_size(const char *img, int *used, int *total) {
+	if (access(img, R_OK) == -1)
+		return 1;
+	char buffer[PATH_MAX];
+	snprintf(buffer, sizeof(buffer), "e2fsck -n %s 2>/dev/null | tail -n 1", img);
+	char *const command[] = { "sh", "-c", buffer, NULL };
+	int pid, fd;
+	pid = run_command(&fd, "/system/bin/sh", command);
+	fdgets(buffer, sizeof(buffer), fd);
+	close(fd);
+	if (pid == -1)
+		return 1;
+	waitpid(pid, NULL, 0);
+	char *tok;
+	tok = strtok(buffer, ",");
+	while(tok != NULL) {
+		if (strstr(tok, "blocks"))
+			break;
+		tok = strtok(NULL, ",");
+	}
+	sscanf(tok, "%d/%d", used, total);
+	*used = *used / 256 + 1;
+	*total /= 256;
+	return 0;
+}
+
+int resize_img(const char *img, int size) {
+	LOGI("Resize %s to %dM\n", img, size);
+	char buffer[PATH_MAX];
+	snprintf(buffer, PATH_MAX, "e2fsck -yf %s; resize2fs %s %dM;", img, img, size);
+	return system(buffer);
+}

jni/utils/utils.h

@@ -91,5 +91,8 @@ int clone_dir(const char *source, const char *target);
 int rm_rf(const char *target);
 void clone_attr(const char *source, const char *target);
 void get_client_cred(int fd, struct ucred *cred);
+int create_img(const char *img, int size);
+int get_img_size(const char *img, int *used, int *total);
+int resize_img(const char *img, int size);
 
 #endif