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         {NULL, 0, NULL, 0}
  50 };
  51
  52 struct common_args common_args;
  53 struct printenv_args printenv_args;
  54 struct setenv_args setenv_args;
  55
  56 void usage_printenv(void)
  57 {
  58
  59         fprintf(stderr,
  60                 "Usage: fw_printenv [OPTIONS]... [VARIABLE]...\n"
  61                 "Print variables from U-Boot environment\n"
  62                 "\n"
  63                 " -h, --help           print this help.\n"
  64 #ifdef CONFIG_ENV_AES
  65                 " -a, --aes            aes key to access environment\n"
  66 #endif
  67 #ifdef CONFIG_FILE
  68                 " -c, --config         configuration file, default:" CONFIG_FILE "\n"
  69 #endif
  70                 " -n, --noheader       do not repeat variable name in output\n"
  71                 "\n");
  72 }
  73
  74 void usage_setenv(void)
  75 {
  76         fprintf(stderr,
  77                 "Usage: fw_setenv [OPTIONS]... [VARIABLE]...\n"
  78                 "Modify variables in U-Boot environment\n"
  79                 "\n"
  80                 " -h, --help           print this help.\n"
  81 #ifdef CONFIG_ENV_AES
  82                 " -a, --aes            aes key to access environment\n"
  83 #endif
  84 #ifdef CONFIG_FILE
  85                 " -c, --config         configuration file, default:" CONFIG_FILE "\n"
  86 #endif
  87                 " -s, --script         batch mode to minimize writes\n"
  88                 "\n"
  89                 "Examples:\n"
  90                 "  fw_setenv foo bar   set variable foo equal bar\n"
  91                 "  fw_setenv foo       clear variable foo\n"
  92                 "  fw_setenv --script file run batch script\n"
  93                 "\n"
  94                 "Script Syntax:\n"
  95                 "  key [space] value\n"
  96                 "  lines starting with '#' are treated as commment\n"
  97                 "\n"
  98                 "  A variable without value will be deleted. Any number of spaces are\n"
  99                 "  allowed between key and value. Space inside of the value is treated\n"
 100                 "  as part of the value itself.\n"
 101                 "\n"
 102                 "Script Example:\n"
 103                 "  netdev         eth0\n"
 104                 "  kernel_addr    400000\n"
 105                 "  foo            empty empty empty    empty empty empty\n"
 106                 "  bar\n"
 107                 "\n");
 108 }
 109
 110 static void parse_common_args(int argc, char *argv[])
 111 {
 112         int c;
 113
 114 #ifdef CONFIG_FILE
 115         common_args.config_file = CONFIG_FILE;
 116 #endif
 117
 118         while ((c = getopt_long(argc, argv, ":a:c:h", long_options, NULL)) !=
 119                EOF) {
 120                 switch (c) {
 121                 case 'a':
 122                         if (parse_aes_key(optarg, common_args.aes_key)) {
 123                                 fprintf(stderr, "AES key parse error\n");
 124                                 exit(EXIT_FAILURE);
 125                         }
 126                         common_args.aes_flag = 1;
 127                         break;
 128 #ifdef CONFIG_FILE
 129                 case 'c':
 130                         common_args.config_file = optarg;
 131                         break;
 132 #endif
 133                 case 'h':
 134                         do_printenv ? usage_printenv() : usage_setenv();
 135                         exit(EXIT_SUCCESS);
 136                         break;
 137                 default:
 138                         /* ignore unknown options */
 139                         break;
 140                 }
 141         }
 142
 143         /* Reset getopt for the next pass. */
 144         opterr = 1;
 145         optind = 1;
 146 }
 147
 148 int parse_printenv_args(int argc, char *argv[])
 149 {
 150         int c;
 151
 152         parse_common_args(argc, argv);
 153
 154         while ((c = getopt_long(argc, argv, "a:c:ns:h", long_options, NULL)) !=
 155                EOF) {
 156                 switch (c) {
 157                 case 'n':
 158                         printenv_args.name_suppress = 1;
 159                         break;
 160                 case 'a':
 161                 case 'c':
 162                 case 'h':
 163                         /* ignore common options */
 164                         break;
 165                 default: /* '?' */
 166                         usage_printenv();
 167                         exit(EXIT_FAILURE);
 168                         break;
 169                 }
 170         }
 171         return 0;
 172 }
 173
 174 int parse_setenv_args(int argc, char *argv[])
 175 {
 176         int c;
 177
 178         parse_common_args(argc, argv);
 179
 180         while ((c = getopt_long(argc, argv, "a:c:ns:h", long_options, NULL)) !=
 181                EOF) {
 182                 switch (c) {
 183                 case 's':
 184                         setenv_args.script_file = optarg;
 185                         break;
 186                 case 'a':
 187                 case 'c':
 188                 case 'h':
 189                         /* ignore common options */
 190                         break;
 191                 default: /* '?' */
 192                         usage_setenv();
 193                         exit(EXIT_FAILURE);
 194                         break;
 195                 }
 196         }
 197         return 0;
 198 }
 199
 200 int main(int argc, char *argv[])
 201 {
 202         const char *lockname = "/var/lock/" CMD_PRINTENV ".lock";
 203         int lockfd = -1;
 204         int retval = EXIT_SUCCESS;
 205         char *_cmdname;
 206
 207         _cmdname = *argv;
 208         if (strrchr(_cmdname, '/') != NULL)
 209                 _cmdname = strrchr(_cmdname, '/') + 1;
 210
 211         if (strcmp(_cmdname, CMD_PRINTENV) == 0) {
 212                 do_printenv = 1;
 213         } else if (strcmp(_cmdname, CMD_SETENV) == 0) {
 214                 do_printenv = 0;
 215         } else {
 216                 fprintf(stderr,
 217                         "Identity crisis - may be called as `%s' or as `%s' but not as `%s'\n",
 218                         CMD_PRINTENV, CMD_SETENV, _cmdname);
 219                 exit(EXIT_FAILURE);
 220         }
 221
 222         if (do_printenv) {
 223                 if (parse_printenv_args(argc, argv))
 224                         exit(EXIT_FAILURE);
 225         } else {
 226                 if (parse_setenv_args(argc, argv))
 227                         exit(EXIT_FAILURE);
 228         }
 229
 230         /* shift parsed flags, jump to non-option arguments */
 231         argc -= optind;
 232         argv += optind;
 233
 234         lockfd = open(lockname, O_WRONLY | O_CREAT | O_TRUNC, 0666);
 235         if (-1 == lockfd) {
 236                 fprintf(stderr, "Error opening lock file %s\n", lockname);
 237                 return EXIT_FAILURE;
 238         }
 239
 240         if (-1 == flock(lockfd, LOCK_EX)) {
 241                 fprintf(stderr, "Error locking file %s\n", lockname);
 242                 close(lockfd);
 243                 return EXIT_FAILURE;
 244         }
 245
 246         if (do_printenv) {
 247                 if (fw_printenv(argc, argv) != 0)
 248                         retval = EXIT_FAILURE;
 249         } else {
 250                 if (!setenv_args.script_file) {
 251                         if (fw_setenv(argc, argv) != 0)
 252                                 retval = EXIT_FAILURE;
 253                 } else {
 254                         if (fw_parse_script(setenv_args.script_file) != 0)
 255                                 retval = EXIT_FAILURE;
 256                 }
 257         }
 258
 259         flock(lockfd, LOCK_UN);
 260         close(lockfd);
 261         return retval;
 262 }