xref: /openbmc/u-boot/tools/env/fw_env_main.c (revision 014a953c)
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 <version.h>
38 #include "fw_env_private.h"
39 #include "fw_env.h"
40 
41 #define CMD_PRINTENV	"fw_printenv"
42 #define CMD_SETENV	"fw_setenv"
43 static int do_printenv;
44 
45 static struct option long_options[] = {
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 	{"version", no_argument, NULL, 'v'},
52 	{NULL, 0, NULL, 0}
53 };
54 
55 static struct env_opts env_opts;
56 
57 /* setenv options */
58 static int noheader;
59 
60 /* getenv options */
61 static char *script_file;
62 
63 void usage_printenv(void)
64 {
65 
66 	fprintf(stderr,
67 		"Usage: fw_printenv [OPTIONS]... [VARIABLE]...\n"
68 		"Print variables from U-Boot environment\n"
69 		"\n"
70 		" -h, --help           print this help.\n"
71 		" -v, --version        display version\n"
72 #ifdef CONFIG_FILE
73 		" -c, --config         configuration file, default:" CONFIG_FILE "\n"
74 #endif
75 		" -n, --noheader       do not repeat variable name in output\n"
76 		" -l, --lock           lock node, default:/var/lock\n"
77 		"\n");
78 }
79 
80 void usage_env_set(void)
81 {
82 	fprintf(stderr,
83 		"Usage: fw_setenv [OPTIONS]... [VARIABLE]...\n"
84 		"Modify variables in U-Boot environment\n"
85 		"\n"
86 		" -h, --help           print this help.\n"
87 		" -v, --version        display version\n"
88 #ifdef CONFIG_FILE
89 		" -c, --config         configuration file, default:" CONFIG_FILE "\n"
90 #endif
91 		" -l, --lock           lock node, default:/var/lock\n"
92 		" -s, --script         batch mode to minimize writes\n"
93 		"\n"
94 		"Examples:\n"
95 		"  fw_setenv foo bar   set variable foo equal bar\n"
96 		"  fw_setenv foo       clear variable foo\n"
97 		"  fw_setenv --script file run batch script\n"
98 		"\n"
99 		"Script Syntax:\n"
100 		"  key [space] value\n"
101 		"  lines starting with '#' are treated as comment\n"
102 		"\n"
103 		"  A variable without value will be deleted. Any number of spaces are\n"
104 		"  allowed between key and value. Space inside of the value is treated\n"
105 		"  as part of the value itself.\n"
106 		"\n"
107 		"Script Example:\n"
108 		"  netdev         eth0\n"
109 		"  kernel_addr    400000\n"
110 		"  foo            empty empty empty    empty empty empty\n"
111 		"  bar\n"
112 		"\n");
113 }
114 
115 static void parse_common_args(int argc, char *argv[])
116 {
117 	int c;
118 
119 #ifdef CONFIG_FILE
120 	env_opts.config_file = CONFIG_FILE;
121 #endif
122 
123 	while ((c = getopt_long(argc, argv, ":a:c:l:h:v", long_options, NULL)) !=
124 	       EOF) {
125 		switch (c) {
126 #ifdef CONFIG_FILE
127 		case 'c':
128 			env_opts.config_file = optarg;
129 			break;
130 #endif
131 		case 'l':
132 			env_opts.lockname = optarg;
133 			break;
134 		case 'h':
135 			do_printenv ? usage_printenv() : usage_env_set();
136 			exit(EXIT_SUCCESS);
137 			break;
138 		case 'v':
139 			fprintf(stderr, "Compiled with " U_BOOT_VERSION "\n");
140 			exit(EXIT_SUCCESS);
141 			break;
142 		default:
143 			/* ignore unknown options */
144 			break;
145 		}
146 	}
147 
148 	/* Reset getopt for the next pass. */
149 	opterr = 1;
150 	optind = 1;
151 }
152 
153 int parse_printenv_args(int argc, char *argv[])
154 {
155 	int c;
156 
157 	parse_common_args(argc, argv);
158 
159 	while ((c = getopt_long(argc, argv, "a:c:ns:l:h:v", long_options, NULL))
160 		!= EOF) {
161 		switch (c) {
162 		case 'n':
163 			noheader = 1;
164 			break;
165 		case 'a':
166 		case 'c':
167 		case 'h':
168 		case 'l':
169 			/* ignore common options */
170 			break;
171 		default: /* '?' */
172 			usage_printenv();
173 			exit(EXIT_FAILURE);
174 			break;
175 		}
176 	}
177 	return 0;
178 }
179 
180 int parse_setenv_args(int argc, char *argv[])
181 {
182 	int c;
183 
184 	parse_common_args(argc, argv);
185 
186 	while ((c = getopt_long(argc, argv, "a:c:ns:l:h:v", long_options, NULL))
187 		!= EOF) {
188 		switch (c) {
189 		case 's':
190 			script_file = optarg;
191 			break;
192 		case 'a':
193 		case 'c':
194 		case 'h':
195 		case 'l':
196 			/* ignore common options */
197 			break;
198 		default: /* '?' */
199 			usage_env_set();
200 			exit(EXIT_FAILURE);
201 			break;
202 		}
203 	}
204 	return 0;
205 }
206 
207 int main(int argc, char *argv[])
208 {
209 	char *lockname = "/var/lock/" CMD_PRINTENV ".lock";
210 	int lockfd = -1;
211 	int retval = EXIT_SUCCESS;
212 	char *_cmdname;
213 
214 	_cmdname = *argv;
215 	if (strrchr(_cmdname, '/') != NULL)
216 		_cmdname = strrchr(_cmdname, '/') + 1;
217 
218 	if (strcmp(_cmdname, CMD_PRINTENV) == 0) {
219 		do_printenv = 1;
220 	} else if (strcmp(_cmdname, CMD_SETENV) == 0) {
221 		do_printenv = 0;
222 	} else {
223 		fprintf(stderr,
224 			"Identity crisis - may be called as `%s' or as `%s' but not as `%s'\n",
225 			CMD_PRINTENV, CMD_SETENV, _cmdname);
226 		exit(EXIT_FAILURE);
227 	}
228 
229 	if (do_printenv) {
230 		if (parse_printenv_args(argc, argv))
231 			exit(EXIT_FAILURE);
232 	} else {
233 		if (parse_setenv_args(argc, argv))
234 			exit(EXIT_FAILURE);
235 	}
236 
237 	/* shift parsed flags, jump to non-option arguments */
238 	argc -= optind;
239 	argv += optind;
240 
241 	if (env_opts.lockname) {
242 		lockname = malloc(sizeof(env_opts.lockname) +
243 				sizeof(CMD_PRINTENV) + 10);
244 		if (!lockname) {
245 			fprintf(stderr, "Unable allocate memory");
246 			exit(EXIT_FAILURE);
247 		}
248 
249 		sprintf(lockname, "%s/%s.lock",
250 			env_opts.lockname, CMD_PRINTENV);
251 	}
252 
253 	lockfd = open(lockname, O_WRONLY | O_CREAT | O_TRUNC, 0666);
254 	if (-1 == lockfd) {
255 		fprintf(stderr, "Error opening lock file %s\n", lockname);
256 		return EXIT_FAILURE;
257 	}
258 
259 	if (-1 == flock(lockfd, LOCK_EX)) {
260 		fprintf(stderr, "Error locking file %s\n", lockname);
261 		close(lockfd);
262 		return EXIT_FAILURE;
263 	}
264 
265 	if (do_printenv) {
266 		if (fw_printenv(argc, argv, noheader, &env_opts) != 0)
267 			retval = EXIT_FAILURE;
268 	} else {
269 		if (!script_file) {
270 			if (fw_env_set(argc, argv, &env_opts) != 0)
271 				retval = EXIT_FAILURE;
272 		} else {
273 			if (fw_parse_script(script_file, &env_opts) != 0)
274 				retval = EXIT_FAILURE;
275 		}
276 	}
277 
278 	if (env_opts.lockname)
279 		free(lockname);
280 
281 	flock(lockfd, LOCK_UN);
282 	close(lockfd);
283 	return retval;
284 }
285