Add defaultenv command

This adds a command to explicitly restore the environment (or
parts thereof) from the default environment.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

commands/Kconfig

@@ -699,6 +699,13 @@ config CMD_EXPORT
 
 	  Export an environment variable to subsequently executed scripts.
 
+config CMD_DEFAULTENV
+	tristate
+	select ENV_HANDLING
+	prompt "defaultenv"
+	help
+	  restore environment from default environment
+
 config CMD_GLOBAL
 	select GLOBALVAR
 	tristate

commands/Makefile

@@ -108,3 +108,4 @@ obj-$(CONFIG_CMD_USBGADGET)	+= usbgadget.o
 obj-$(CONFIG_CMD_FIRMWARELOAD)	+= firmwareload.o
 obj-$(CONFIG_CMD_CMP)		+= cmp.o
 obj-$(CONFIG_CMD_NV)		+= nv.o
+obj-$(CONFIG_CMD_DEFAULTENV)	+= defaultenv.o

commands/defaultenv.c

@@ -0,0 +1,95 @@
+/*
+ * Copyright (c) 2014 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <common.h>
+#include <getopt.h>
+#include <command.h>
+#include <envfs.h>
+#include <errno.h>
+#include <fs.h>
+#include <libfile.h>
+#include <malloc.h>
+#include <globalvar.h>
+
+static int do_defaultenv(int argc, char *argv[])
+{
+	char *dirname;
+	int opt, ret;
+	char *restorepath = "/";
+	char *from, *to;
+	int restore = 0, scrub = 0;
+
+	while ((opt = getopt(argc, argv, "p:rs")) > 0) {
+		switch (opt) {
+		case 'r':
+			restore = 1;
+			break;
+		case 'p':
+			restorepath = optarg;
+			break;
+		case 's':
+			scrub = 1;
+			break;
+		default:
+			return COMMAND_ERROR_USAGE;
+		}
+	}
+
+	if (!restore || argc != optind)
+		return COMMAND_ERROR_USAGE;
+
+	dirname = "/env";
+
+	make_directory(dirname);
+
+	ret = defaultenv_load("/.defaultenv", 0);
+	if (ret)
+		return ret;
+
+	from = asprintf("/.defaultenv/%s", restorepath);
+	to = asprintf("%s/%s", dirname, restorepath);
+
+	printf("Restoring %s from default environment\n", restorepath);
+
+	if (scrub)
+		unlink_recursive(to, NULL);
+
+	ret = copy_recursive(from, to);
+	free(from);
+	free(to);
+
+	nvvar_load();
+
+	unlink_recursive("/.defaultenv", NULL);
+
+	return ret;
+}
+
+BAREBOX_CMD_HELP_START(defaultenv)
+BAREBOX_CMD_HELP_TEXT("Options:")
+BAREBOX_CMD_HELP_OPT("-r", "restore default environment")
+BAREBOX_CMD_HELP_OPT("-s", "scrub, remove files not in default environment")
+BAREBOX_CMD_HELP_OPT("-p <PATH>", "limit to <PATH>")
+BAREBOX_CMD_HELP_END
+
+BAREBOX_CMD_START(defaultenv)
+	.cmd		= do_defaultenv,
+	BAREBOX_CMD_DESC("Restore environment from default environment")
+	BAREBOX_CMD_OPTS("[-rs] [-p <PATH>]")
+	BAREBOX_CMD_GROUP(CMD_GRP_ENV)
+	BAREBOX_CMD_HELP(cmd_defaultenv_help)
+BAREBOX_CMD_END