Fix proper Lollipop selinux support

jni/Android.mk

@@ -93,8 +93,8 @@ include $(BUILD_EXECUTABLE)
 ifeq ($(TARGET_ARCH_ABI), arm64-v8a)
 include $(CLEAR_VARS)
 LOCAL_MODULE := magiskinit
-LOCAL_STATIC_LIBRARIES := libsepol libselinux_static
-LOCAL_C_INCLUDES := jni/include $(LIBSEPOL) $(LIBSELINUX)
+LOCAL_STATIC_LIBRARIES := libsepol
+LOCAL_C_INCLUDES := jni/include $(LIBSEPOL)
 LOCAL_SRC_FILES := \
 	magiskinit.c \
 	magiskboot/boot_utils.c \
@@ -103,6 +103,7 @@ LOCAL_SRC_FILES := \
 	magiskpolicy/rules.c \
 	magiskpolicy/sepolicy.c \
 	magiskpolicy/api.c
+LOCAL_CFLAGS := -DNO_SELINUX
 LOCAL_LDFLAGS := -static
 include $(BUILD_EXECUTABLE)
 endif

jni/external/Android.mk

@@ -14,14 +14,6 @@ LOCAL_C_INCLUDES := $(LIBSELINUX)
 LOCAL_SRC_FILES := stubs/selinux_stub.c
 include $(BUILD_SHARED_LIBRARY)
 
-# libselinux_static.a (stub)
-include $(CLEAR_VARS)
-LOCAL_MODULE:= libselinux_static
-LOCAL_C_INCLUDES := $(LIBSELINUX)
-LOCAL_SRC_FILES := stubs/selinux_stub.c
-include $(BUILD_STATIC_LIBRARY)
-
-
 # libfdt
 include $(CLEAR_VARS)
 LOCAL_MODULE:= libfdt

jni/include/utils.h

@@ -99,6 +99,7 @@ struct file_attr {
 	char con[128];
 };
 
+int fd_getpath(int fd, char *path, size_t size);
 int mkdir_p(const char *pathname, mode_t mode);
 void rm_rf(const char *path);
 void frm_rf(int dirfd);

jni/utils/file.c

@@ -5,7 +5,10 @@
 #include <fcntl.h>
 #include <unistd.h>
 #include <sys/sendfile.h>
+
+#ifndef NO_SELINUX
 #include <selinux/selinux.h>
+#endif
 
 #include "utils.h"
 
@@ -19,6 +22,13 @@ static int is_excl(const char *name) {
 	return 0;
 }
 
+int fd_getpath(int fd, char *path, size_t size) {
+	snprintf(path, size, "/proc/self/fd/%d", fd);
+	if (xreadlink(path, path, size) == -1)
+		return -1;
+	return 0;
+}
+
 int mkdir_p(const char *pathname, mode_t mode) {
 	char *path = strdup(pathname), *p;
 	errno = 0;
@@ -201,16 +211,22 @@ void clone_dir(int src, int dest) {
 }
 
 int getattr(const char *path, struct file_attr *a) {
-	int fd = open(path, O_PATH | O_NOFOLLOW | O_CLOEXEC);
-	if (fd < 0)
+	if (xlstat(path, &a->st) == -1)
 		return -1;
-	int ret = fgetattr(fd, a);
-	close(fd);
-	return ret;
+	char *con = "";
+#ifndef NO_SELINUX
+	if (lgetfilecon(path, &con) == -1)
+		return -1;
+	strcpy(a->con, con);
+	freecon(con);
+#else
+	a->con[0] = '\0';
+#endif
+	return 0;
 }
 
 int getattrat(int dirfd, const char *pathname, struct file_attr *a) {
-	int fd = openat(dirfd, pathname, O_PATH | O_NOFOLLOW | O_CLOEXEC);
+	int fd = xopenat(dirfd, pathname, O_PATH | O_NOFOLLOW | O_CLOEXEC);
 	if (fd < 0)
 		return -1;
 	int ret = fgetattr(fd, a);
@@ -219,27 +235,32 @@ int getattrat(int dirfd, const char *pathname, struct file_attr *a) {
 }
 
 int fgetattr(int fd, struct file_attr *a) {
-	if (fstat(fd, &a->st) < 0)
+#ifndef NO_SELINUX
+	char path[PATH_MAX];
+	fd_getpath(fd, path, sizeof(path));
+	return getattr(path, a);
+#else
+	if (fstat(fd, &a->st) == -1)
 		return -1;
-	char *con = "";
-	if (fgetfilecon(fd, &con) < 0)
-		return -1;
-	strcpy(a->con, con);
-	freecon(con);
+	a->con[0] = '\0';
 	return 0;
+#endif
 }
 
 int setattr(const char *path, struct file_attr *a) {
-	int fd = open(path, O_PATH | O_NOFOLLOW | O_CLOEXEC);
-	if (fd < 0)
+	if (chmod(path, a->st.st_mode & 0777) < 0)
 		return -1;
-	int ret = fsetattr(fd, a);
-	close(fd);
-	return ret;
+	if (chown(path, a->st.st_uid, a->st.st_gid) < 0)
+		return -1;
+#ifndef NO_SELINUX
+	if (strlen(a->con) && lsetfilecon(path, a->con) < 0)
+		return -1;
+#endif
+	return 0;
 }
 
 int setattrat(int dirfd, const char *pathname, struct file_attr *a) {
-	int fd = openat(dirfd, pathname, O_PATH | O_NOFOLLOW | O_CLOEXEC);
+	int fd = xopenat(dirfd, pathname, O_PATH | O_NOFOLLOW | O_CLOEXEC);
 	if (fd < 0)
 		return -1;
 	int ret = fsetattr(fd, a);
@@ -248,13 +269,17 @@ int setattrat(int dirfd, const char *pathname, struct file_attr *a) {
 }
 
 int fsetattr(int fd, struct file_attr *a) {
+#ifndef NO_SELINUX
+	char path[PATH_MAX];
+	fd_getpath(fd, path, sizeof(path));
+	return setattr(path, a);
+#else
 	if (fchmod(fd, a->st.st_mode & 0777) < 0)
 		return -1;
 	if (fchown(fd, a->st.st_uid, a->st.st_gid) < 0)
 		return -1;
-	if (strlen(a->con) && fsetfilecon(fd, a->con) < 0)
-		return -1;
 	return 0;
+#endif
 }
 
 void clone_attr(const char *source, const char *target) {
@@ -269,6 +294,8 @@ void fclone_attr(const int sourcefd, const int targetfd) {
 	fsetattr(targetfd, &a);
 }
 
+#ifndef NO_SELINUX
+
 #define UNLABEL_CON "u:object_r:unlabeled:s0"
 #define SYSTEM_CON  "u:object_r:system_file:s0"
 
@@ -276,11 +303,12 @@ void restorecon(int dirfd, int force) {
 	struct dirent *entry;
 	DIR *dir;
 	int fd;
-	char *con;
+	char path[PATH_MAX], *con;
 
-	fgetfilecon(dirfd, &con);
+	fd_getpath(dirfd, path, sizeof(path));
+	lgetfilecon(path, &con);
 	if (force || strlen(con) == 0 || strcmp(con, UNLABEL_CON) == 0)
-		fsetfilecon(dirfd, SYSTEM_CON);
+		lsetfilecon(path, SYSTEM_CON);
 	freecon(con);
 
 	dir = xfdopendir(dirfd);
@@ -292,11 +320,14 @@ void restorecon(int dirfd, int force) {
 			restorecon(fd, force);
 		} else {
 			fd = xopenat(dirfd, entry->d_name, O_PATH | O_NOFOLLOW | O_CLOEXEC);
-			fgetfilecon(fd, &con);
+			fd_getpath(fd, path, sizeof(path));
+			lgetfilecon(path, &con);
 			if (force || strlen(con) == 0 || strcmp(con, UNLABEL_CON) == 0)
-				fsetfilecon(fd, SYSTEM_CON);
+				lsetfilecon(path, SYSTEM_CON);
 			freecon(con);
 		}
 		close(fd);
 	}
 }
+
+#endif   // NO_SELINUX

jni/utils/img.c

@@ -163,6 +163,7 @@ void umount_image(const char *target, const char *device) {
 int merge_img(const char *source, const char *target) {
 	if (access(source, F_OK) == -1)
 		return 0;
+	LOGI("* Merging %s  -> %s\n", source, target);
 	if (access(target, F_OK) == -1) {
 		xrename(source, target);
 		return 0;