tools/env/fw_env_main.c

   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.h"
  38
  39 #define CMD_PRINTENV    "fw_printenv"
  40 #define CMD_SETENV      "fw_setenv"
  41 static int do_printenv;
  42
  43 static struct option long_options[] = {
  44         {"aes", required_argument, NULL, 'a'},
  45         {"config", required_argument, NULL, 'c'},
  46         {"help", no_argument, NULL, 'h'},
  47         {"script", required_argument, NULL, 's'},
  48         {"noheader", required_argument, NULL, 'n'},
  49         {"lock", required_argument, NULL, 'l'},
  50         {NULL, 0, NULL, 0}
  51 };
  52
  53 static struct env_opts env_opts;
  54
  55 /* setenv options */
  56 static int noheader;
  57
  58 /* getenv options */
  59 static char *script_file;
  60
  61 void usage_printenv(void)
  62 {
  63
  64         fprintf(stderr,
  65                 "Usage: fw_printenv [OPTIONS]... [VARIABLE]...\n"
  66                 "Print variables from U-Boot environment\n"
  67                 "\n"
  68                 " -h, --help           print this help.\n"
  69 #ifdef CONFIG_ENV_AES
  70                 " -a, --aes            aes key to access environment\n"
  71 #endif
  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_setenv(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 #ifdef CONFIG_ENV_AES
  88                 " -a, --aes            aes key to access environment\n"
  89 #endif
  90 #ifdef CONFIG_FILE
  91                 " -c, --config         configuration file, default:" CONFIG_FILE "\n"
  92 #endif
  93                 " -l, --lock           lock node, default:/var/lock\n"
  94                 " -s, --script         batch mode to minimize writes\n"
  95                 "\n"
  96                 "Examples:\n"
  97                 "  fw_setenv foo bar   set variable foo equal bar\n"
  98                 "  fw_setenv foo       clear variable foo\n"
  99                 "  fw_setenv --script file run batch script\n"
 100                 "\n"
 101                 "Script Syntax:\n"
 102                 "  key [space] value\n"
 103                 "  lines starting with '#' are treated as comment\n"
 104                 "\n"
 105                 "  A variable without value will be deleted. Any number of spaces are\n"
 106                 "  allowed between key and value. Space inside of the value is treated\n"
 107                 "  as part of the value itself.\n"
 108                 "\n"
 109                 "Script Example:\n"
 110                 "  netdev         eth0\n"
 111                 "  kernel_addr    400000\n"
 112                 "  foo            empty empty empty    empty empty empty\n"
 113                 "  bar\n"
 114                 "\n");
 115 }
 116
 117 static void parse_common_args(int argc, char *argv[])
 118 {
 119         int c;
 120
 121 #ifdef CONFIG_FILE
 122         env_opts.config_file = CONFIG_FILE;
 123 #endif
 124
 125         while ((c = getopt_long(argc, argv, ":a:c:l:h", long_options, NULL)) !=
 126                EOF) {
 127                 switch (c) {
 128                 case 'a':
 129                         if (parse_aes_key(optarg, env_opts.aes_key)) {
 130                                 fprintf(stderr, "AES key parse error\n");
 131                                 exit(EXIT_FAILURE);
 132                         }
 133                         env_opts.aes_flag = 1;
 134                         break;
 135 #ifdef CONFIG_FILE
 136                 case 'c':
 137                         env_opts.config_file = optarg;
 138                         break;
 139 #endif
 140                 case 'l':
 141                         env_opts.lockname = optarg;
 142                         break;
 143                 case 'h':
 144                         do_printenv ? usage_printenv() : usage_setenv();
 145                         exit(EXIT_SUCCESS);
 146                         break;
 147                 default:
 148                         /* ignore unknown options */
 149                         break;
 150                 }
 151         }
 152
 153         /* Reset getopt for the next pass. */
 154         opterr = 1;
 155         optind = 1;
 156 }
 157
 158 int parse_printenv_args(int argc, char *argv[])
 159 {
 160         int c;
 161
 162         parse_common_args(argc, argv);
 163
 164         while ((c = getopt_long(argc, argv, "a:c:ns:l:h", long_options, NULL))
 165                 != EOF) {
 166                 switch (c) {
 167                 case 'n':
 168                         noheader = 1;
 169                         break;
 170                 case 'a':
 171                 case 'c':
 172                 case 'h':
 173                 case 'l':
 174                         /* ignore common options */
 175                         break;
 176                 default: /* '?' */
 177                         usage_printenv();
 178                         exit(EXIT_FAILURE);
 179                         break;
 180                 }
 181         }
 182         return 0;
 183 }
 184
 185 int parse_setenv_args(int argc, char *argv[])
 186 {
 187         int c;
 188
 189         parse_common_args(argc, argv);
 190
 191         while ((c = getopt_long(argc, argv, "a:c:ns:l:h", long_options, NULL))
 192                 != EOF) {
 193                 switch (c) {
 194                 case 's':
 195                         script_file = optarg;
 196                         break;
 197                 case 'a':
 198                 case 'c':
 199                 case 'h':
 200                 case 'l':
 201                         /* ignore common options */
 202                         break;
 203                 default: /* '?' */
 204                         usage_setenv();
 205                         exit(EXIT_FAILURE);
 206                         break;
 207                 }
 208         }
 209         return 0;
 210 }
 211
 212 int main(int argc, char *argv[])
 213 {
 214         char *lockname = "/var/lock/" CMD_PRINTENV ".lock";
 215         int lockfd = -1;
 216         int retval = EXIT_SUCCESS;
 217         char *_cmdname;
 218
 219         _cmdname = *argv;
 220         if (strrchr(_cmdname, '/') != NULL)
 221                 _cmdname = strrchr(_cmdname, '/') + 1;
 222
 223         if (strcmp(_cmdname, CMD_PRINTENV) == 0) {
 224                 do_printenv = 1;
 225         } else if (strcmp(_cmdname, CMD_SETENV) == 0) {
 226                 do_printenv = 0;
 227         } else {
 228                 fprintf(stderr,
 229                         "Identity crisis - may be called as `%s' or as `%s' but not as `%s'\n",
 230                         CMD_PRINTENV, CMD_SETENV, _cmdname);
 231                 exit(EXIT_FAILURE);
 232         }
 233
 234         if (do_printenv) {
 235                 if (parse_printenv_args(argc, argv))
 236                         exit(EXIT_FAILURE);
 237         } else {
 238                 if (parse_setenv_args(argc, argv))
 239                         exit(EXIT_FAILURE);
 240         }
 241
 242         /* shift parsed flags, jump to non-option arguments */
 243         argc -= optind;
 244         argv += optind;
 245
 246         if (env_opts.lockname) {
 247                 lockname = malloc(sizeof(env_opts.lockname) +
 248                                 sizeof(CMD_PRINTENV) + 10);
 249                 if (!lockname) {
 250                         fprintf(stderr, "Unable allocate memory");
 251                         exit(EXIT_FAILURE);
 252                 }
 253
 254                 sprintf(lockname, "%s/%s.lock",
 255                         env_opts.lockname, CMD_PRINTENV);
 256         }
 257
 258         lockfd = open(lockname, O_WRONLY | O_CREAT | O_TRUNC, 0666);
 259         if (-1 == lockfd) {
 260                 fprintf(stderr, "Error opening lock file %s\n", lockname);
 261                 return EXIT_FAILURE;
 262         }
 263
 264         if (-1 == flock(lockfd, LOCK_EX)) {
 265                 fprintf(stderr, "Error locking file %s\n", lockname);
 266                 close(lockfd);
 267                 return EXIT_FAILURE;
 268         }
 269
 270         if (do_printenv) {
 271                 if (fw_printenv(argc, argv, noheader, &env_opts) != 0)
 272                         retval = EXIT_FAILURE;
 273         } else {
 274                 if (!script_file) {
 275                         if (fw_setenv(argc, argv, &env_opts) != 0)
 276                                 retval = EXIT_FAILURE;
 277                 } else {
 278                         if (fw_parse_script(script_file, &env_opts) != 0)
 279                                 retval = EXIT_FAILURE;
 280                 }
 281         }
 282
 283         if (env_opts.lockname)
 284                 free(lockname);
 285
 286         flock(lockfd, LOCK_UN);
 287         close(lockfd);
 288         return retval;
 289 }