Create xbps_walk_dir function.

It's used in both xbps-create and xbps-uchroot. Even though neither
uses the "dirent" arg in fn, leave it in for possible future use.

This implementation also fixes a bug with the version of walk_dir in
those binaries where it leaks all the list[i] items. This version frees
them after using them and does a final cleanup in case the for loop
ended before going through all of them.

xbps-create requires this function to use alphasort, but xbps-uchroot
wouldn't. For implemenation simplicity, use alphasort in all cases.

include/xbps_utils.h

@@ -0,0 +1,32 @@
+/*-
+ * Copyright (c) 2021 Érico Nogueira Rolim.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *-
+ */
+
+#include <dirent.h>
+
+#include "xbps_api_impl.h"
+
+int HIDDEN xbps_walk_dir(const char *,
+		int (*fn) (const char *, const struct stat *, const struct dirent *));

lib/Makefile

@@ -51,6 +51,7 @@ OBJS += repo.o repo_sync.o
 OBJS += rpool.o cb_util.o proplib_wrapper.o
 OBJS += package_alternatives.o
 OBJS += conf.o log.o
+OBJS += walk_dir.o
 OBJS += $(EXTOBJS) $(COMPAT_OBJS)
 # unnecessary unless pkgdb format changes
 # OBJS += pkgdb_conversion.o

lib/walk_dir.c

@@ -0,0 +1,83 @@
+/*-
+ * Copyright (c) 2021 Érico Nogueira Rolim.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <stdlib.h>
+#include <string.h>
+#include <dirent.h>
+#include <errno.h>
+#include <limits.h>
+
+#include <xbps.h>
+#include "xbps_utils.h"
+
+int
+xbps_walk_dir(const char *path,
+		int (*fn) (const char *, const struct stat *, const struct dirent *))
+{
+	int rv, i, count;
+	struct dirent **list;
+	char tmp_path[PATH_MAX] = { 0 };
+	struct stat sb;
+
+	count = scandir(path, &list, NULL, alphasort);
+	for (i = count - 1; i >= 0; i--) {
+		if (strcmp(list[i]->d_name, ".") == 0 || strcmp(list[i]->d_name, "..") == 0)
+			goto cleanup;
+		if (strlen(path) + strlen(list[i]->d_name) + 1 >= PATH_MAX - 1) {
+			errno = ENAMETOOLONG;
+			rv = -1;
+			break;
+		}
+		strncpy(tmp_path, path, PATH_MAX - 1);
+		strncat(tmp_path, "/", PATH_MAX - 1 - strlen(tmp_path));
+		strncat(tmp_path, list[i]->d_name, PATH_MAX - 1 - strlen(tmp_path));
+		if (lstat(tmp_path, &sb) < 0) {
+			break;
+		}
+
+		if (S_ISDIR(sb.st_mode)) {
+			if (xbps_walk_dir(tmp_path, fn) < 0) {
+				rv = -1;
+				break;
+			}
+		}
+
+		rv = fn(tmp_path, &sb, list[i]);
+		if (rv != 0) {
+			break;
+
+		cleanup:
+			free(list[i]);
+		}
+
+	}
+	for (; i >= 0; i--) {
+		free(list[i]);
+	}
+	free(list);
+	return rv;
+}