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_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_env_set(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_env_set();
 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_env_set();
 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_env_set(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 }