Massive sepolicy refactor

native/jni/core/bootstages.c

@@ -19,6 +19,7 @@
 #include "utils.h"
 #include "daemon.h"
 #include "resetprop.h"
+#include "magiskpolicy.h"
 
 static char *buf, *buf2;
 static struct vector module_list;
@@ -451,7 +452,7 @@ static int prepare_img() {
 
 void fix_filecon() {
 	int dirfd = xopen(MOUNTPOINT, O_RDONLY | O_CLOEXEC);
-	restorecon(dirfd, 0);
+	restorecon(dirfd);
 	close(dirfd);
 }
 
@@ -621,8 +622,7 @@ void late_start(int client) {
 	if (buf2 == NULL) buf2 = xmalloc(PATH_MAX);
 
 	// Wait till the full patch is done
-	wait_till_exists(PATCHDONE);
-	unlink(PATCHDONE);
+	waitpid(full_patch_pid, NULL, 0);
 
 	// Run scripts after full patch, most reliable way to run scripts
 	LOGI("* Running service.d scripts\n");
@@ -639,7 +639,7 @@ core_only:
 	// Install Magisk Manager if exists
 	if (access(MANAGERAPK, F_OK) == 0) {
 		rename(MANAGERAPK, "/data/magisk.apk");
-		setfilecon("/data/magisk.apk", "u:object_r:su_file:s0");
+		setfilecon("/data/magisk.apk", "u:object_r:"SEPOL_FILE_DOMAIN":s0");
 		while (1) {
 			sleep(5);
 			LOGD("apk_install: attempting to install APK");

native/jni/core/daemon.c

@@ -19,8 +19,11 @@
 #include "utils.h"
 #include "daemon.h"
 #include "resetprop.h"
+#include "magiskpolicy.h"
 
-int is_daemon_init = 0, seperate_vendor = 0;
+int is_daemon_init = 0;
+int seperate_vendor = 0;
+int full_patch_pid;
 
 static void *request_handler(void *args) {
 	int client = *((int *) args);
@@ -133,23 +136,50 @@ void daemon_init() {
 	LOGI("* Creating /sbin overlay");
 	DIR *dir;
 	struct dirent *entry;
-	int root, sbin;
+	int root, sbin, fd;
 	char buf[PATH_MAX], buf2[PATH_MAX];
-	char magisk_name[10], init_name[10];
+	void *data;
+	size_t size;
 
-	// Setup links under /sbin
+	// Create hardlink mirror of /sbin to /root
 	xmount(NULL, "/", NULL, MS_REMOUNT, NULL);
-	xmkdir("/root", 0755);
-	chmod("/root", 0755);
+	full_read("/sbin/magisk", &data, &size);
 	root = xopen("/root", O_RDONLY | O_CLOEXEC);
 	sbin = xopen("/sbin", O_RDONLY | O_CLOEXEC);
 	link_dir(sbin, root);
 	unlink("/sbin/magisk");
 	close(sbin);
 
+	// Mount the /sbin tmpfs overlay
 	xmount("tmpfs", "/sbin", "tmpfs", 0, NULL);
 	chmod("/sbin", 0755);
 	setfilecon("/sbin", "u:object_r:rootfs:s0");
+
+	// Setup magisk
+	fd = creat("/sbin/magisk", 0755);
+	xwrite(fd, data, size);
+	close(fd);
+	free(data);
+	setfilecon("/sbin/magisk", "u:object_r:"SEPOL_FILE_DOMAIN":s0");
+	for (int i = 0; applet[i]; ++i) {
+		snprintf(buf, PATH_MAX, "/sbin/%s", applet[i]);
+		xsymlink("/sbin/magisk", buf);
+	}
+
+	// Setup magiskinit
+	full_read("/root/magiskinit", &data, &size);
+	unlink("/root/magiskinit");
+	fd = creat("/sbin/magiskinit", 0755);
+	xwrite(fd, data, size);
+	close(fd);
+	free(data);
+	setfilecon("/sbin/magiskinit", "u:object_r:"SEPOL_FILE_DOMAIN":s0");
+	for (int i = 0; init_applet[i]; ++i) {
+		snprintf(buf, PATH_MAX, "/sbin/%s", init_applet[i]);
+		xsymlink("/sbin/magiskinit", buf);
+	}
+
+	// Create symlinks pointing back to /root
 	dir = xfdopendir(root);
 	while((entry = xreaddir(dir))) {
 		if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0) continue;
@@ -158,29 +188,11 @@ void daemon_init() {
 		xsymlink(buf, buf2);
 	}
 
-	gen_rand_str(magisk_name, sizeof(magisk_name));
-	snprintf(buf, PATH_MAX, "/root/%s", magisk_name);
-	unlink("/sbin/magisk");
-	rename("/root/magisk", buf);
-	xsymlink(buf, "/sbin/magisk");
-	for (int i = 0; applet[i]; ++i) {
-		snprintf(buf2, PATH_MAX, "/sbin/%s", applet[i]);
-		xsymlink(buf, buf2);
-	}
-
-	gen_rand_str(init_name, sizeof(init_name));
-	snprintf(buf, PATH_MAX, "/root/%s", init_name);
-	unlink("/sbin/magiskinit");
-	rename("/root/magiskinit", buf);
-	for (int i = 0; init_applet[i]; ++i) {
-		snprintf(buf2, PATH_MAX, "/sbin/%s", init_applet[i]);
-		xsymlink(buf, buf2);
-	}
-
 	close(root);
-
 	xmount(NULL, "/", NULL, MS_REMOUNT | MS_RDONLY, NULL);
 
+	full_patch_pid = exec_command(0, NULL, NULL, "/sbin/magiskpolicy", "--live", "allow "SEPOL_PROC_DOMAIN" * * *", NULL);
+
 	LOGI("* Mounting mirrors");
 	struct vector mounts;
 	vec_init(&mounts);
@@ -239,7 +251,7 @@ void daemon_init() {
 
 void start_daemon() {
 	setsid();
-	setcon("u:r:su:s0");
+	setcon("u:r:"SEPOL_PROC_DOMAIN":s0");
 	umask(0);
 	int fd = xopen("/dev/null", O_RDWR | O_CLOEXEC);
 	xdup2(fd, STDIN_FILENO);

native/jni/core/magiskinit.c

@@ -339,7 +339,7 @@ static void patch_socket_name(const char *path) {
 	mmap_rw(path, &buf, &size);
 	if (SOCKET_OFF < 0) {
 		for (int i = 0; i < size; ++i) {
-			if (memcmp(buf + i, socket_name, sizeof(SOCKET_NAME)) == 0) {
+			if (memcmp(buf + i, SOCKET_NAME, sizeof(SOCKET_NAME)) == 0) {
 				SOCKET_OFF = i;
 				break;
 			}
@@ -350,55 +350,6 @@ static void patch_socket_name(const char *path) {
 	munmap(buf, size);
 }
 
-static void magisk_init_daemon() {
-	setsid();
-
-	// Full patch
-	sepol_allow("su", ALL, ALL, ALL);
-
-	// Wait till init cold boot done
-	while (access("/dev/.coldboot_done", F_OK))
-		usleep(1);
-
-	int null = open("/dev/null", O_RDWR | O_CLOEXEC);
-	dup3(null, STDIN_FILENO, O_CLOEXEC);
-	dup3(null, STDOUT_FILENO, O_CLOEXEC);
-	dup3(null, STDERR_FILENO, O_CLOEXEC);
-	if (null > STDERR_FILENO)
-		close(null);
-
-	// Transit our context to su (mimic setcon)
-	int fd, crap;
-	fd = open("/proc/self/attr/current", O_WRONLY);
-	write(fd, "u:r:su:s0", 9);
-	close(fd);
-
-	// Dump full patch to kernel
-	dump_policydb(SELINUX_LOAD);
-	close(creat(PATCHDONE, 0));
-	destroy_policydb();
-
-	// Keep Magisk daemon always alive
-	while (1) {
-		struct sockaddr_un sun;
-		fd = setup_socket(&sun);
-		memcpy(sun.sun_path + 1, RAND_SOCKET_NAME, sizeof(SOCKET_NAME));
-		while (connect(fd, (struct sockaddr*) &sun, sizeof(sun)))
-			usleep(10000); /* Wait 10 ms after each try */
-
-		/* Should hold forever */
-		read(fd, &crap, sizeof(crap));
-
-		/* If things went here, it means the other side of the socket is closed
-		 * We restart the daemon again */
-		close(fd);
-		if (fork_dont_care() == 0) {
-			execv("/sbin/magisk", (char *[]) { "magisk", "--daemon", NULL } );
-			exit(1);
-		}
-	}
-}
-
 int main(int argc, char *argv[]) {
 	umask(0);
 
@@ -430,7 +381,7 @@ int main(int argc, char *argv[]) {
 	mkdir("/overlay/sbin", 0755);
 	dump_magisk("/overlay/sbin/magisk", 0755);
 	patch_socket_name("/overlay/sbin/magisk");
-	mkdir("/overlay/root", 0755);
+	mkdir("/overlay/root", 0750);
 	link("/init", "/overlay/root/magiskinit");
 
 	struct cmdline cmd;
@@ -520,20 +471,13 @@ int main(int argc, char *argv[]) {
 
 		patch_ramdisk();
 		patch_sepolicy();
-
-		close(STDIN_FILENO);
-		close(STDOUT_FILENO);
-		close(STDERR_FILENO);
-
-		if (fork_dont_care() == 0) {
-			strcpy(argv[0], "magiskinit");
-			close(root);
-			magisk_init_daemon();
-		}
 	}
 
 	// Clean up
 	close(root);
+	close(STDIN_FILENO);
+	close(STDOUT_FILENO);
+	close(STDERR_FILENO);
 	if (!cmd.skip_initramfs)
 		umount("/system");
 	umount("/vendor");

native/jni/core/socket.c

@@ -8,7 +8,7 @@
 #include "utils.h"
 #include "magisk.h"
 
-char socket_name[] = SOCKET_NAME;
+static char socket_name[] = SOCKET_NAME;  /* Workaround compiler bug pre NDK r13 */
 
 /* Setup the address and return socket fd */
 int setup_socket(struct sockaddr_un *sun) {