xref: /openbmc/u-boot/tools/env/fw_env_main.c (revision e30d2bd4)
1 /*
2  * (C) Copyright 2000-2008
3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 /*
9  * Command line user interface to firmware (=U-Boot) environment.
10  *
11  * Implements:
12  *	fw_printenv [ -a key ] [[ -n name ] | [ name ... ]]
13  *              - prints the value of a single environment variable
14  *                "name", the ``name=value'' pairs of one or more
15  *                environment variables "name", or the whole
16  *                environment if no names are specified.
17  *	fw_setenv [ -a key ] name [ value ... ]
18  *		- If a name without any values is given, the variable
19  *		  with this name is deleted from the environment;
20  *		  otherwise, all "value" arguments are concatenated,
21  *		  separated by single blank characters, and the
22  *		  resulting string is assigned to the environment
23  *		  variable "name"
24  *
25  * If '-a key' is specified, the env block is encrypted with AES 128 CBC.
26  * The 'key' argument is in the format of 32 hexadecimal numbers (16 bytes
27  * of AES key), eg. '-a aabbccddeeff00112233445566778899'.
28  */
29 
30 #include <fcntl.h>
31 #include <getopt.h>
32 #include <stdio.h>
33 #include <string.h>
34 #include <stdlib.h>
35 #include <sys/file.h>
36 #include <unistd.h>
37 #include "fw_env_private.h"
38 #include "fw_env.h"
39 
40 #define CMD_PRINTENV	"fw_printenv"
41 #define CMD_SETENV	"fw_setenv"
42 static int do_printenv;
43 
44 static struct option long_options[] = {
45 	{"aes", required_argument, NULL, 'a'},
46 	{"config", required_argument, NULL, 'c'},
47 	{"help", no_argument, NULL, 'h'},
48 	{"script", required_argument, NULL, 's'},
49 	{"noheader", required_argument, NULL, 'n'},
50 	{"lock", required_argument, NULL, 'l'},
51 	{NULL, 0, NULL, 0}
52 };
53 
54 static struct env_opts env_opts;
55 
56 /* setenv options */
57 static int noheader;
58 
59 /* getenv options */
60 static char *script_file;
61 
62 void usage_printenv(void)
63 {
64 
65 	fprintf(stderr,
66 		"Usage: fw_printenv [OPTIONS]... [VARIABLE]...\n"
67 		"Print variables from U-Boot environment\n"
68 		"\n"
69 		" -h, --help           print this help.\n"
70 #ifdef CONFIG_ENV_AES
71 		" -a, --aes            aes key to access environment\n"
72 #endif
73 #ifdef CONFIG_FILE
74 		" -c, --config         configuration file, default:" CONFIG_FILE "\n"
75 #endif
76 		" -n, --noheader       do not repeat variable name in output\n"
77 		" -l, --lock           lock node, default:/var/lock\n"
78 		"\n");
79 }
80 
81 void usage_setenv(void)
82 {
83 	fprintf(stderr,
84 		"Usage: fw_setenv [OPTIONS]... [VARIABLE]...\n"
85 		"Modify variables in U-Boot environment\n"
86 		"\n"
87 		" -h, --help           print this help.\n"
88 #ifdef CONFIG_ENV_AES
89 		" -a, --aes            aes key to access environment\n"
90 #endif
91 #ifdef CONFIG_FILE
92 		" -c, --config         configuration file, default:" CONFIG_FILE "\n"
93 #endif
94 		" -l, --lock           lock node, default:/var/lock\n"
95 		" -s, --script         batch mode to minimize writes\n"
96 		"\n"
97 		"Examples:\n"
98 		"  fw_setenv foo bar   set variable foo equal bar\n"
99 		"  fw_setenv foo       clear variable foo\n"
100 		"  fw_setenv --script file run batch script\n"
101 		"\n"
102 		"Script Syntax:\n"
103 		"  key [space] value\n"
104 		"  lines starting with '#' are treated as comment\n"
105 		"\n"
106 		"  A variable without value will be deleted. Any number of spaces are\n"
107 		"  allowed between key and value. Space inside of the value is treated\n"
108 		"  as part of the value itself.\n"
109 		"\n"
110 		"Script Example:\n"
111 		"  netdev         eth0\n"
112 		"  kernel_addr    400000\n"
113 		"  foo            empty empty empty    empty empty empty\n"
114 		"  bar\n"
115 		"\n");
116 }
117 
118 static void parse_common_args(int argc, char *argv[])
119 {
120 	int c;
121 
122 #ifdef CONFIG_FILE
123 	env_opts.config_file = CONFIG_FILE;
124 #endif
125 
126 	while ((c = getopt_long(argc, argv, ":a:c:l:h", long_options, NULL)) !=
127 	       EOF) {
128 		switch (c) {
129 		case 'a':
130 			if (parse_aes_key(optarg, env_opts.aes_key)) {
131 				fprintf(stderr, "AES key parse error\n");
132 				exit(EXIT_FAILURE);
133 			}
134 			env_opts.aes_flag = 1;
135 			break;
136 #ifdef CONFIG_FILE
137 		case 'c':
138 			env_opts.config_file = optarg;
139 			break;
140 #endif
141 		case 'l':
142 			env_opts.lockname = optarg;
143 			break;
144 		case 'h':
145 			do_printenv ? usage_printenv() : usage_setenv();
146 			exit(EXIT_SUCCESS);
147 			break;
148 		default:
149 			/* ignore unknown options */
150 			break;
151 		}
152 	}
153 
154 	/* Reset getopt for the next pass. */
155 	opterr = 1;
156 	optind = 1;
157 }
158 
159 int parse_printenv_args(int argc, char *argv[])
160 {
161 	int c;
162 
163 	parse_common_args(argc, argv);
164 
165 	while ((c = getopt_long(argc, argv, "a:c:ns:l:h", long_options, NULL))
166 		!= EOF) {
167 		switch (c) {
168 		case 'n':
169 			noheader = 1;
170 			break;
171 		case 'a':
172 		case 'c':
173 		case 'h':
174 		case 'l':
175 			/* ignore common options */
176 			break;
177 		default: /* '?' */
178 			usage_printenv();
179 			exit(EXIT_FAILURE);
180 			break;
181 		}
182 	}
183 	return 0;
184 }
185 
186 int parse_setenv_args(int argc, char *argv[])
187 {
188 	int c;
189 
190 	parse_common_args(argc, argv);
191 
192 	while ((c = getopt_long(argc, argv, "a:c:ns:l:h", long_options, NULL))
193 		!= EOF) {
194 		switch (c) {
195 		case 's':
196 			script_file = optarg;
197 			break;
198 		case 'a':
199 		case 'c':
200 		case 'h':
201 		case 'l':
202 			/* ignore common options */
203 			break;
204 		default: /* '?' */
205 			usage_setenv();
206 			exit(EXIT_FAILURE);
207 			break;
208 		}
209 	}
210 	return 0;
211 }
212 
213 int main(int argc, char *argv[])
214 {
215 	char *lockname = "/var/lock/" CMD_PRINTENV ".lock";
216 	int lockfd = -1;
217 	int retval = EXIT_SUCCESS;
218 	char *_cmdname;
219 
220 	_cmdname = *argv;
221 	if (strrchr(_cmdname, '/') != NULL)
222 		_cmdname = strrchr(_cmdname, '/') + 1;
223 
224 	if (strcmp(_cmdname, CMD_PRINTENV) == 0) {
225 		do_printenv = 1;
226 	} else if (strcmp(_cmdname, CMD_SETENV) == 0) {
227 		do_printenv = 0;
228 	} else {
229 		fprintf(stderr,
230 			"Identity crisis - may be called as `%s' or as `%s' but not as `%s'\n",
231 			CMD_PRINTENV, CMD_SETENV, _cmdname);
232 		exit(EXIT_FAILURE);
233 	}
234 
235 	if (do_printenv) {
236 		if (parse_printenv_args(argc, argv))
237 			exit(EXIT_FAILURE);
238 	} else {
239 		if (parse_setenv_args(argc, argv))
240 			exit(EXIT_FAILURE);
241 	}
242 
243 	/* shift parsed flags, jump to non-option arguments */
244 	argc -= optind;
245 	argv += optind;
246 
247 	if (env_opts.lockname) {
248 		lockname = malloc(sizeof(env_opts.lockname) +
249 				sizeof(CMD_PRINTENV) + 10);
250 		if (!lockname) {
251 			fprintf(stderr, "Unable allocate memory");
252 			exit(EXIT_FAILURE);
253 		}
254 
255 		sprintf(lockname, "%s/%s.lock",
256 			env_opts.lockname, CMD_PRINTENV);
257 	}
258 
259 	lockfd = open(lockname, O_WRONLY | O_CREAT | O_TRUNC, 0666);
260 	if (-1 == lockfd) {
261 		fprintf(stderr, "Error opening lock file %s\n", lockname);
262 		return EXIT_FAILURE;
263 	}
264 
265 	if (-1 == flock(lockfd, LOCK_EX)) {
266 		fprintf(stderr, "Error locking file %s\n", lockname);
267 		close(lockfd);
268 		return EXIT_FAILURE;
269 	}
270 
271 	if (do_printenv) {
272 		if (fw_printenv(argc, argv, noheader, &env_opts) != 0)
273 			retval = EXIT_FAILURE;
274 	} else {
275 		if (!script_file) {
276 			if (fw_setenv(argc, argv, &env_opts) != 0)
277 				retval = EXIT_FAILURE;
278 		} else {
279 			if (fw_parse_script(script_file, &env_opts) != 0)
280 				retval = EXIT_FAILURE;
281 		}
282 	}
283 
284 	if (env_opts.lockname)
285 		free(lockname);
286 
287 	flock(lockfd, LOCK_UN);
288 	close(lockfd);
289 	return retval;
290 }
291