u-boot/tools/env/fw_env_main.c

/*
 * (C) Copyright 2000-2008
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

/*
 * Command line user interface to firmware (=U-Boot) environment.
 *
 * Implements:
 *	fw_printenv [ -a key ] [[ -n name ] | [ name ... ]]
 *              - prints the value of a single environment variable
 *                "name", the ``name=value'' pairs of one or more
 *                environment variables "name", or the whole
 *                environment if no names are specified.
 *	fw_setenv [ -a key ] name [ value ... ]
 *		- If a name without any values is given, the variable
 *		  with this name is deleted from the environment;
 *		  otherwise, all "value" arguments are concatenated,
 *		  separated by single blank characters, and the
 *		  resulting string is assigned to the environment
 *		  variable "name"
 *
 * If '-a key' is specified, the env block is encrypted with AES 128 CBC.
 * The 'key' argument is in the format of 32 hexadecimal numbers (16 bytes
 * of AES key), eg. '-a aabbccddeeff00112233445566778899'.
 */

#include <fcntl.h>
#include <getopt.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/file.h>
#include <unistd.h>
#include "fw_env.h"

#define	CMD_PRINTENV	"fw_printenv"
#define CMD_SETENV	"fw_setenv"

static struct option long_options[] = {
	{"script", required_argument, NULL, 's'},
	{"help", no_argument, NULL, 'h'},
	{NULL, 0, NULL, 0}
};

struct common_args common_args;
struct printenv_args printenv_args;
struct setenv_args setenv_args;

void usage(void)
{

	fprintf(stderr, "fw_printenv/fw_setenv, "
		"a command line interface to U-Boot environment\n\n"
#ifndef CONFIG_FILE
		"usage:\tfw_printenv [-a key] [-n] [variable name]\n"
		"\tfw_setenv [-a key] [variable name] [variable value]\n"
#else
		"usage:\tfw_printenv [-c /my/fw_env.config] [-a key] [-n] [variable name]\n"
		"\tfw_setenv [-c /my/fw_env.config] [-a key] [variable name] [variable value]\n"
#endif
		"\tfw_setenv -s [ file ]\n"
		"\tfw_setenv -s - < [ file ]\n\n"
		"The file passed as argument contains only pairs "
		"name / value\n"
		"Example:\n"
		"# Any line starting with # is treated as comment\n"
		"\n"
		"\t      netdev         eth0\n"
		"\t      kernel_addr    400000\n"
		"\t      var1\n"
		"\t      var2          The quick brown fox jumps over the "
		"lazy dog\n"
		"\n"
		"A variable without value will be dropped. It is possible\n"
		"to put any number of spaces between the fields, but any\n"
		"space inside the value is treated as part of the value "
		"itself.\n\n"
	);
}

static void parse_common_args(int argc, char *argv[])
{
	int c;

#ifdef CONFIG_FILE
	common_args.config_file = CONFIG_FILE;
#endif

	while ((c = getopt_long(argc, argv, ":a:c:h", long_options, NULL)) !=
	       EOF) {
		switch (c) {
		case 'a':
			if (parse_aes_key(optarg, common_args.aes_key)) {
				fprintf(stderr, "AES key parse error\n");
				exit(EXIT_FAILURE);
			}
			common_args.aes_flag = 1;
			break;
#ifdef CONFIG_FILE
		case 'c':
			common_args.config_file = optarg;
			break;
#endif
		case 'h':
			usage();
			exit(EXIT_SUCCESS);
			break;
		default:
			/* ignore unknown options */
			break;
		}
	}

	/* Reset getopt for the next pass. */
	opterr = 1;
	optind = 1;
}

int parse_printenv_args(int argc, char *argv[])
{
	int c;

	parse_common_args(argc, argv);

	while ((c = getopt_long(argc, argv, "a:c:ns:h", long_options, NULL)) !=
	       EOF) {
		switch (c) {
		case 'n':
			printenv_args.name_suppress = 1;
			break;
		case 'a':
		case 'c':
		case 'h':
			/* ignore common options */
			break;
		default: /* '?' */
			usage();
			exit(EXIT_FAILURE);
			break;
		}
	}
	return 0;
}

int parse_setenv_args(int argc, char *argv[])
{
	int c;

	parse_common_args(argc, argv);

	while ((c = getopt_long(argc, argv, "a:c:ns:h", long_options, NULL)) !=
	       EOF) {
		switch (c) {
		case 's':
			setenv_args.script_file = optarg;
			break;
		case 'a':
		case 'c':
		case 'h':
			/* ignore common options */
			break;
		default: /* '?' */
			usage();
			exit(EXIT_FAILURE);
			break;
		}
	}
	return 0;
}

int main(int argc, char *argv[])
{
	char *cmdname = *argv;
	const char *lockname = "/var/lock/" CMD_PRINTENV ".lock";
	int lockfd = -1;
	int retval = EXIT_SUCCESS;

	if (strrchr(cmdname, '/') != NULL)
		cmdname = strrchr(cmdname, '/') + 1;

	if (strcmp(cmdname, CMD_PRINTENV) == 0) {
		if (parse_printenv_args(argc, argv))
			exit(EXIT_FAILURE);
	} else if (strcmp(cmdname, CMD_SETENV) == 0) {
		if (parse_setenv_args(argc, argv))
			exit(EXIT_FAILURE);
	} else {
		fprintf(stderr,
			"Identity crisis - may be called as `%s' or as `%s' but not as `%s'\n",
			CMD_PRINTENV, CMD_SETENV, cmdname);
		exit(EXIT_FAILURE);
	}

	/* shift parsed flags, jump to non-option arguments */
	argc -= optind;
	argv += optind;

	lockfd = open(lockname, O_WRONLY | O_CREAT | O_TRUNC, 0666);
	if (-1 == lockfd) {
		fprintf(stderr, "Error opening lock file %s\n", lockname);
		return EXIT_FAILURE;
	}

	if (-1 == flock(lockfd, LOCK_EX)) {
		fprintf(stderr, "Error locking file %s\n", lockname);
		close(lockfd);
		return EXIT_FAILURE;
	}

	if (strcmp(cmdname, CMD_PRINTENV) == 0) {
		if (fw_printenv(argc, argv) != 0)
			retval = EXIT_FAILURE;
	} else if (strcmp(cmdname, CMD_SETENV) == 0) {
		if (!setenv_args.script_file) {
			if (fw_setenv(argc, argv) != 0)
				retval = EXIT_FAILURE;
		} else {
			if (fw_parse_script(setenv_args.script_file) != 0)
				retval = EXIT_FAILURE;
		}
	}

	flock(lockfd, LOCK_UN);
	close(lockfd);
	return retval;
}