common/autoboot.c

   1 /*
   2  * (C) Copyright 2000
   3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 #include <common.h>
   9 #include <autoboot.h>
  10 #include <bootretry.h>
  11 #include <cli.h>
  12 #include <console.h>
  13 #include <fdtdec.h>
  14 #include <menu.h>
  15 #include <post.h>
  16 #include <u-boot/sha256.h>
  17
  18 DECLARE_GLOBAL_DATA_PTR;
  19
  20 #define MAX_DELAY_STOP_STR 32
  21
  22 #ifndef DEBUG_BOOTKEYS
  23 #define DEBUG_BOOTKEYS 0
  24 #endif
  25 #define debug_bootkeys(fmt, args...)            \
  26         debug_cond(DEBUG_BOOTKEYS, fmt, ##args)
  27
  28 /* Stored value of bootdelay, used by autoboot_command() */
  29 static int stored_bootdelay;
  30
  31 #if defined(CONFIG_AUTOBOOT_KEYED)
  32 #if defined(CONFIG_AUTOBOOT_STOP_STR_SHA256)
  33
  34 /*
  35  * Use a "constant-length" time compare function for this
  36  * hash compare:
  37  *
  38  * https://crackstation.net/hashing-security.htm
  39  */
  40 static int slow_equals(u8 *a, u8 *b, int len)
  41 {
  42         int diff = 0;
  43         int i;
  44
  45         for (i = 0; i < len; i++)
  46                 diff |= a[i] ^ b[i];
  47
  48         return diff == 0;
  49 }
  50
  51 static int passwd_abort(uint64_t etime)
  52 {
  53         const char *sha_env_str = env_get("bootstopkeysha256");
  54         u8 sha_env[SHA256_SUM_LEN];
  55         u8 sha[SHA256_SUM_LEN];
  56         char presskey[MAX_DELAY_STOP_STR];
  57         const char *algo_name = "sha256";
  58         u_int presskey_len = 0;
  59         int abort = 0;
  60         int size;
  61         int ret;
  62
  63         if (sha_env_str == NULL)
  64                 sha_env_str = CONFIG_AUTOBOOT_STOP_STR_SHA256;
  65
  66         /*
  67          * Generate the binary value from the environment hash value
  68          * so that we can compare this value with the computed hash
  69          * from the user input
  70          */
  71         ret = hash_parse_string(algo_name, sha_env_str, sha_env);
  72         if (ret) {
  73                 printf("Hash %s not supported!\n", algo_name);
  74                 return 0;
  75         }
  76
  77         /*
  78          * We don't know how long the stop-string is, so we need to
  79          * generate the sha256 hash upon each input character and
  80          * compare the value with the one saved in the environment
  81          */
  82         do {
  83                 if (tstc()) {
  84                         /* Check for input string overflow */
  85                         if (presskey_len >= MAX_DELAY_STOP_STR)
  86                                 return 0;
  87
  88                         presskey[presskey_len++] = getc();
  89
  90                         /* Calculate sha256 upon each new char */
  91                         hash_block(algo_name, (const void *)presskey,
  92                                    presskey_len, sha, &size);
  93
  94                         /* And check if sha matches saved value in env */
  95                         if (slow_equals(sha, sha_env, SHA256_SUM_LEN))
  96                                 abort = 1;
  97                 }
  98         } while (!abort && get_ticks() <= etime);
  99
 100         return abort;
 101 }
 102 #else
 103 static int passwd_abort(uint64_t etime)
 104 {
 105         int abort = 0;
 106         struct {
 107                 char *str;
 108                 u_int len;
 109                 int retry;
 110         }
 111         delaykey[] = {
 112                 { .str = env_get("bootdelaykey"),  .retry = 1 },
 113                 { .str = env_get("bootstopkey"),   .retry = 0 },
 114         };
 115
 116         char presskey[MAX_DELAY_STOP_STR];
 117         u_int presskey_len = 0;
 118         u_int presskey_max = 0;
 119         u_int i;
 120
 121 #  ifdef CONFIG_AUTOBOOT_DELAY_STR
 122         if (delaykey[0].str == NULL)
 123                 delaykey[0].str = CONFIG_AUTOBOOT_DELAY_STR;
 124 #  endif
 125 #  ifdef CONFIG_AUTOBOOT_STOP_STR
 126         if (delaykey[1].str == NULL)
 127                 delaykey[1].str = CONFIG_AUTOBOOT_STOP_STR;
 128 #  endif
 129
 130         for (i = 0; i < sizeof(delaykey) / sizeof(delaykey[0]); i++) {
 131                 delaykey[i].len = delaykey[i].str == NULL ?
 132                                     0 : strlen(delaykey[i].str);
 133                 delaykey[i].len = delaykey[i].len > MAX_DELAY_STOP_STR ?
 134                                     MAX_DELAY_STOP_STR : delaykey[i].len;
 135
 136                 presskey_max = presskey_max > delaykey[i].len ?
 137                                     presskey_max : delaykey[i].len;
 138
 139                 debug_bootkeys("%s key:<%s>\n",
 140                                delaykey[i].retry ? "delay" : "stop",
 141                                delaykey[i].str ? delaykey[i].str : "NULL");
 142         }
 143
 144         /* In order to keep up with incoming data, check timeout only
 145          * when catch up.
 146          */
 147         do {
 148                 if (tstc()) {
 149                         if (presskey_len < presskey_max) {
 150                                 presskey[presskey_len++] = getc();
 151                         } else {
 152                                 for (i = 0; i < presskey_max - 1; i++)
 153                                         presskey[i] = presskey[i + 1];
 154
 155                                 presskey[i] = getc();
 156                         }
 157                 }
 158
 159                 for (i = 0; i < sizeof(delaykey) / sizeof(delaykey[0]); i++) {
 160                         if (delaykey[i].len > 0 &&
 161                             presskey_len >= delaykey[i].len &&
 162                                 memcmp(presskey + presskey_len -
 163                                         delaykey[i].len, delaykey[i].str,
 164                                         delaykey[i].len) == 0) {
 165                                         debug_bootkeys("got %skey\n",
 166                                                 delaykey[i].retry ? "delay" :
 167                                                 "stop");
 168
 169                                 /* don't retry auto boot */
 170                                 if (!delaykey[i].retry)
 171                                         bootretry_dont_retry();
 172                                 abort = 1;
 173                         }
 174                 }
 175         } while (!abort && get_ticks() <= etime);
 176
 177         return abort;
 178 }
 179 #endif
 180
 181 /***************************************************************************
 182  * Watch for 'delay' seconds for autoboot stop or autoboot delay string.
 183  * returns: 0 -  no key string, allow autoboot 1 - got key string, abort
 184  */
 185 static int __abortboot(int bootdelay)
 186 {
 187         int abort;
 188         uint64_t etime = endtick(bootdelay);
 189
 190 #  ifdef CONFIG_AUTOBOOT_PROMPT
 191         /*
 192          * CONFIG_AUTOBOOT_PROMPT includes the %d for all boards.
 193          * To print the bootdelay value upon bootup.
 194          */
 195         printf(CONFIG_AUTOBOOT_PROMPT, bootdelay);
 196 #  endif
 197
 198         abort = passwd_abort(etime);
 199         if (!abort)
 200                 debug_bootkeys("key timeout\n");
 201
 202         return abort;
 203 }
 204
 205 # else  /* !defined(CONFIG_AUTOBOOT_KEYED) */
 206
 207 #ifdef CONFIG_MENUKEY
 208 static int menukey;
 209 #endif
 210
 211 static int __abortboot(int bootdelay)
 212 {
 213         int abort = 0;
 214         unsigned long ts;
 215
 216 #ifdef CONFIG_MENUPROMPT
 217         printf(CONFIG_MENUPROMPT);
 218 #else
 219         printf("Hit any key to stop autoboot: %2d ", bootdelay);
 220 #endif
 221
 222         /*
 223          * Check if key already pressed
 224          */
 225         if (tstc()) {   /* we got a key press   */
 226                 (void) getc();  /* consume input        */
 227                 puts("\b\b\b 0");
 228                 abort = 1;      /* don't auto boot      */
 229         }
 230
 231         while ((bootdelay > 0) && (!abort)) {
 232                 --bootdelay;
 233                 /* delay 1000 ms */
 234                 ts = get_timer(0);
 235                 do {
 236                         if (tstc()) {   /* we got a key press   */
 237                                 abort  = 1;     /* don't auto boot      */
 238                                 bootdelay = 0;  /* no more delay        */
 239 # ifdef CONFIG_MENUKEY
 240                                 menukey = getc();
 241 # else
 242                                 (void) getc();  /* consume input        */
 243 # endif
 244                                 break;
 245                         }
 246                         udelay(10000);
 247                 } while (!abort && get_timer(ts) < 1000);
 248
 249                 printf("\b\b\b%2d ", bootdelay);
 250         }
 251
 252         putc('\n');
 253
 254         return abort;
 255 }
 256 # endif /* CONFIG_AUTOBOOT_KEYED */
 257
 258 static int abortboot(int bootdelay)
 259 {
 260         int abort = 0;
 261
 262         if (bootdelay >= 0)
 263                 abort = __abortboot(bootdelay);
 264
 265 #ifdef CONFIG_SILENT_CONSOLE
 266         if (abort)
 267                 gd->flags &= ~GD_FLG_SILENT;
 268 #endif
 269
 270         return abort;
 271 }
 272
 273 static void process_fdt_options(const void *blob)
 274 {
 275 #if defined(CONFIG_OF_CONTROL) && defined(CONFIG_SYS_TEXT_BASE)
 276         ulong addr;
 277
 278         /* Add an env variable to point to a kernel payload, if available */
 279         addr = fdtdec_get_config_int(gd->fdt_blob, "kernel-offset", 0);
 280         if (addr)
 281                 env_set_addr("kernaddr", (void *)(CONFIG_SYS_TEXT_BASE + addr));
 282
 283         /* Add an env variable to point to a root disk, if available */
 284         addr = fdtdec_get_config_int(gd->fdt_blob, "rootdisk-offset", 0);
 285         if (addr)
 286                 env_set_addr("rootaddr", (void *)(CONFIG_SYS_TEXT_BASE + addr));
 287 #endif /* CONFIG_OF_CONTROL && CONFIG_SYS_TEXT_BASE */
 288 }
 289
 290 const char *bootdelay_process(void)
 291 {
 292         char *s;
 293         int bootdelay;
 294 #ifdef CONFIG_BOOTCOUNT_LIMIT
 295         unsigned long bootcount = 0;
 296         unsigned long bootlimit = 0;
 297 #endif /* CONFIG_BOOTCOUNT_LIMIT */
 298
 299 #ifdef CONFIG_BOOTCOUNT_LIMIT
 300         bootcount = bootcount_load();
 301         bootcount++;
 302         bootcount_store(bootcount);
 303         env_set_ulong("bootcount", bootcount);
 304         bootlimit = env_get_ulong("bootlimit", 10, 0);
 305 #endif /* CONFIG_BOOTCOUNT_LIMIT */
 306
 307         s = env_get("bootdelay");
 308         bootdelay = s ? (int)simple_strtol(s, NULL, 10) : CONFIG_BOOTDELAY;
 309
 310 #ifdef CONFIG_OF_CONTROL
 311         bootdelay = fdtdec_get_config_int(gd->fdt_blob, "bootdelay",
 312                         bootdelay);
 313 #endif
 314
 315         debug("### main_loop entered: bootdelay=%d\n\n", bootdelay);
 316
 317 #if defined(CONFIG_MENU_SHOW)
 318         bootdelay = menu_show(bootdelay);
 319 #endif
 320         bootretry_init_cmd_timeout();
 321
 322 #ifdef CONFIG_POST
 323         if (gd->flags & GD_FLG_POSTFAIL) {
 324                 s = env_get("failbootcmd");
 325         } else
 326 #endif /* CONFIG_POST */
 327 #ifdef CONFIG_BOOTCOUNT_LIMIT
 328         if (bootlimit && (bootcount > bootlimit)) {
 329                 printf("Warning: Bootlimit (%u) exceeded. Using altbootcmd.\n",
 330                        (unsigned)bootlimit);
 331                 s = env_get("altbootcmd");
 332         } else
 333 #endif /* CONFIG_BOOTCOUNT_LIMIT */
 334                 s = env_get("bootcmd");
 335
 336         process_fdt_options(gd->fdt_blob);
 337         stored_bootdelay = bootdelay;
 338
 339         return s;
 340 }
 341
 342 void autoboot_command(const char *s)
 343 {
 344         debug("### main_loop: bootcmd=\"%s\"\n", s ? s : "<UNDEFINED>");
 345
 346         if (stored_bootdelay != -1 && s && !abortboot(stored_bootdelay)) {
 347 #if defined(CONFIG_AUTOBOOT_KEYED) && !defined(CONFIG_AUTOBOOT_KEYED_CTRLC)
 348                 int prev = disable_ctrlc(1);    /* disable Control C checking */
 349 #endif
 350
 351                 run_command_list(s, -1, 0);
 352
 353 #if defined(CONFIG_AUTOBOOT_KEYED) && !defined(CONFIG_AUTOBOOT_KEYED_CTRLC)
 354                 disable_ctrlc(prev);    /* restore Control C checking */
 355 #endif
 356         }
 357
 358 #ifdef CONFIG_MENUKEY
 359         if (menukey == CONFIG_MENUKEY) {
 360                 s = env_get("menucmd");
 361                 if (s)
 362                         run_command_list(s, -1, 0);
 363         }
 364 #endif /* CONFIG_MENUKEY */
 365 }