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 <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 }