db, fix: more secure way to choose effective directory permissions

And implement --directory-permissions for fix-applet to reset all
directory uid, gid and modes.

src/audit.c

@@ -38,6 +38,8 @@ static int audit_file(struct apk_database *db, struct apk_db_file *dbf,
 	if (S_ISLNK(fi.mode) && dbf->csum.type == APK_CHECKSUM_NONE)
 		return 0;
 
+	/* FIXME: check uid/gid/mode; but they are not in DB */
+
 	return 1;
 }
 
@@ -74,8 +76,10 @@ static int audit_directory(apk_hash_item item, void *ctx)
 			continue;
 
 		if (S_ISDIR(fi.mode)) {
-			if (apk_db_dir_query(db, APK_BLOB_STR(tmp)) != NULL)
+			if (apk_db_dir_query(db, APK_BLOB_STR(tmp)) != NULL) {
+				/* FIXME: check uid/gid/mode */
 				continue;
+			}
 
 			reason = 'D';
 		} else {

src/database.c

@@ -220,6 +220,13 @@ struct apk_name *apk_db_get_name(struct apk_database *db, apk_blob_t name)
 
 static void apk_db_dir_mkdir(struct apk_database *db, struct apk_db_dir *dir)
 {
+	if (apk_flags & APK_SIMULATE)
+		return;
+
+	/* Don't mess with root, as no package provides it directly */
+	if (dir->namelen == 0)
+		return;
+
 	if ((dir->refs == 1) ||
 	    (fchmodat(db->root_fd, dir->name, dir->mode, AT_SYMLINK_NOFOLLOW) != 0 &&
 	     errno == ENOENT))
@@ -363,19 +370,14 @@ static void apk_db_dir_apply_diri_permissions(struct apk_db_dir_instance *diri)
 {
 	struct apk_db_dir *dir = diri->dir;
 
-	if (diri->uid < dir->uid) {
+	if (diri->uid < dir->uid ||
+	    (diri->uid == dir->uid && diri->gid < dir->gid)) {
 		dir->uid = diri->uid;
-		dir->mode = (dir->mode & ~S_IRWXU) | (diri->mode & S_IRWXU);
-	} else if (diri->uid == dir->uid) {
-		dir->mode |= diri->mode & S_IRWXU;
-	}
-	if (diri->gid < dir->gid) {
 		dir->gid = diri->gid;
-		dir->mode = (dir->mode & ~S_IRWXG) | (diri->mode & S_IRWXG);
-	} else if (diri->gid == dir->gid) {
-		dir->mode |= diri->mode & S_IRWXG;
+		dir->mode = diri->mode;
+	} else if (diri->uid == dir->uid && diri->gid == dir->gid) {
+		dir->mode &= diri->mode;
 	}
-	dir->mode |= diri->mode & S_IRWXO;
 }
 
 static void apk_db_diri_set(struct apk_db_dir_instance *diri, mode_t mode,

src/fix.c

@@ -21,6 +21,7 @@
 struct fix_ctx {
 	unsigned short solver_flags;
 	int fix_depends : 1;
+	int fix_directory_permissions : 1;
 };
 
 static int fix_parse(void *pctx, struct apk_db_options *dbopts,
@@ -37,12 +38,22 @@ static int fix_parse(void *pctx, struct apk_db_options *dbopts,
 	case 'r':
 		ctx->solver_flags |= APK_SOLVERF_REINSTALL;
 		break;
+	case 0x10000:
+		ctx->fix_directory_permissions = 1;
+		break;
 	default:
 		return -1;
 	}
 	return 0;
 }
 
+static int mark_recalculate(apk_hash_item item, void *ctx)
+{
+	struct apk_db_dir *dir = (struct apk_db_dir *) item;
+	dir->flags |= APK_DBDIRF_RECALC_MODE;
+	return 0;
+}
+
 static int fix_main(void *pctx, struct apk_database *db, int argc, char **argv)
 {
 	struct fix_ctx *ctx = (struct fix_ctx *) pctx;
@@ -53,6 +64,9 @@ static int fix_main(void *pctx, struct apk_database *db, int argc, char **argv)
 	if (!ctx->solver_flags)
 		ctx->solver_flags = APK_SOLVERF_REINSTALL;
 
+	if (ctx->fix_directory_permissions)
+		apk_hash_foreach(&db->installed.dirs, mark_recalculate, db);
+
 	for (i = 0; i < argc; i++) {
 		pkg = NULL;
 		if (strstr(argv[i], ".apk") != NULL) {
@@ -95,6 +109,7 @@ static struct apk_option fix_options[] = {
 	{ 'd',		"depends",	"Fix all dependencies too" },
 	{ 'u',		"upgrade",	"Upgrade package if possible" },
 	{ 'r',		"reinstall",	"Reinstall the package" },
+	{ 0x10000,	"directory-permissions", "Reset all directory permissions" },
 };
 
 static struct apk_applet apk_fix = {