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 <fdtdec.h>
  13 #include <menu.h>
  14 #include <post.h>
  15 #include <u-boot/sha256.h>
  16
  17 DECLARE_GLOBAL_DATA_PTR;
  18
  19 #define MAX_DELAY_STOP_STR 32
  20
  21 #ifndef DEBUG_BOOTKEYS
  22 #define DEBUG_BOOTKEYS 0
  23 #endif
  24 #define debug_bootkeys(fmt, args...)            \
  25         debug_cond(DEBUG_BOOTKEYS, fmt, ##args)
  26
  27 /* Stored value of bootdelay, used by autoboot_command() */
  28 static int stored_bootdelay;
  29
  30 #if defined(CONFIG_AUTOBOOT_KEYED)
  31 #if defined(CONFIG_AUTOBOOT_STOP_STR_SHA256)
  32
  33 /*
  34  * Use a "constant-length" time compare function for this
  35  * hash compare:
  36  *
  37  * https://crackstation.net/hashing-security.htm
  38  */
  39 static int slow_equals(u8 *a, u8 *b, int len)
  40 {
  41         int diff = 0;
  42         int i;
  43
  44         for (i = 0; i < len; i++)
  45                 diff |= a[i] ^ b[i];
  46
  47         return diff == 0;
  48 }
  49
  50 static int passwd_abort(uint64_t etime)
  51 {
  52         const char *sha_env_str = getenv("bootstopkeysha256");
  53         u8 sha_env[SHA256_SUM_LEN];
  54         u8 sha[SHA256_SUM_LEN];
  55         char presskey[MAX_DELAY_STOP_STR];
  56         const char *algo_name = "sha256";
  57         u_int presskey_len = 0;
  58         int abort = 0;
  59         int size;
  60         int ret;
  61
  62         if (sha_env_str == NULL)
  63                 sha_env_str = CONFIG_AUTOBOOT_STOP_STR_SHA256;
  64
  65         /*
  66          * Generate the binary value from the environment hash value
  67          * so that we can compare this value with the computed hash
  68          * from the user input
  69          */
  70         ret = hash_parse_string(algo_name, sha_env_str, sha_env);
  71         if (ret) {
  72                 printf("Hash %s not supported!\n", algo_name);
  73                 return 0;
  74         }
  75
  76         /*
  77          * We don't know how long the stop-string is, so we need to
  78          * generate the sha256 hash upon each input character and
  79          * compare the value with the one saved in the environment
  80          */
  81         do {
  82                 if (tstc()) {
  83                         /* Check for input string overflow */
  84                         if (presskey_len >= MAX_DELAY_STOP_STR)
  85                                 return 0;
  86
  87                         presskey[presskey_len++] = getc();
  88
  89                         /* Calculate sha256 upon each new char */
  90                         hash_block(algo_name, (const void *)presskey,
  91                                    presskey_len, sha, &size);
  92
  93                         /* And check if sha matches saved value in env */
  94                         if (slow_equals(sha, sha_env, SHA256_SUM_LEN))
  95                                 abort = 1;
  96                 }
  97         } while (!abort && get_ticks() <= etime);
  98
  99         return abort;
 100 }
 101 #else
 102 static int passwd_abort(uint64_t etime)
 103 {
 104         int abort = 0;
 105         struct {
 106                 char *str;
 107                 u_int len;
 108                 int retry;
 109         }
 110         delaykey[] = {
 111                 { .str = getenv("bootdelaykey"),  .retry = 1 },
 112                 { .str = getenv("bootstopkey"),   .retry = 0 },
 113         };
 114
 115         char presskey[MAX_DELAY_STOP_STR];
 116         u_int presskey_len = 0;
 117         u_int presskey_max = 0;
 118         u_int i;
 119
 120 #  ifdef CONFIG_AUTOBOOT_DELAY_STR
 121         if (delaykey[0].str == NULL)
 122                 delaykey[0].str = CONFIG_AUTOBOOT_DELAY_STR;
 123 #  endif
 124 #  ifdef CONFIG_AUTOBOOT_STOP_STR
 125         if (delaykey[1].str == NULL)
 126                 delaykey[1].str = CONFIG_AUTOBOOT_STOP_STR;
 127 #  endif
 128
 129         for (i = 0; i < sizeof(delaykey) / sizeof(delaykey[0]); i++) {
 130                 delaykey[i].len = delaykey[i].str == NULL ?
 131                                     0 : strlen(delaykey[i].str);
 132                 delaykey[i].len = delaykey[i].len > MAX_DELAY_STOP_STR ?
 133                                     MAX_DELAY_STOP_STR : delaykey[i].len;
 134
 135                 presskey_max = presskey_max > delaykey[i].len ?
 136                                     presskey_max : delaykey[i].len;
 137
 138                 debug_bootkeys("%s key:<%s>\n",
 139                                delaykey[i].retry ? "delay" : "stop",
 140                                delaykey[i].str ? delaykey[i].str : "NULL");
 141         }
 142
 143         /* In order to keep up with incoming data, check timeout only
 144          * when catch up.
 145          */
 146         do {
 147                 if (tstc()) {
 148                         if (presskey_len < presskey_max) {
 149                                 presskey[presskey_len++] = getc();
 150                         } else {
 151                                 for (i = 0; i < presskey_max - 1; i++)
 152                                         presskey[i] = presskey[i + 1];
 153
 154                                 presskey[i] = getc();
 155                         }
 156                 }
 157
 158                 for (i = 0; i < sizeof(delaykey) / sizeof(delaykey[0]); i++) {
 159                         if (delaykey[i].len > 0 &&
 160                             presskey_len >= delaykey[i].len &&
 161                                 memcmp(presskey + presskey_len -
 162                                         delaykey[i].len, delaykey[i].str,
 163                                         delaykey[i].len) == 0) {
 164                                         debug_bootkeys("got %skey\n",
 165                                                 delaykey[i].retry ? "delay" :
 166                                                 "stop");
 167
 168                                 /* don't retry auto boot */
 169                                 if (!delaykey[i].retry)
 170                                         bootretry_dont_retry();
 171                                 abort = 1;
 172                         }
 173                 }
 174         } while (!abort && get_ticks() <= etime);
 175
 176         return abort;
 177 }
 178 #endif
 179
 180 /***************************************************************************
 181  * Watch for 'delay' seconds for autoboot stop or autoboot delay string.
 182  * returns: 0 -  no key string, allow autoboot 1 - got key string, abort
 183  */
 184 static int abortboot_keyed(int bootdelay)
 185 {
 186         int abort;
 187         uint64_t etime = endtick(bootdelay);
 188
 189 #ifndef CONFIG_ZERO_BOOTDELAY_CHECK
 190         if (bootdelay == 0)
 191                 return 0;
 192 #endif
 193
 194 #  ifdef CONFIG_AUTOBOOT_PROMPT
 195         /*
 196          * CONFIG_AUTOBOOT_PROMPT includes the %d for all boards.
 197          * To print the bootdelay value upon bootup.
 198          */
 199         printf(CONFIG_AUTOBOOT_PROMPT, bootdelay);
 200 #  endif
 201
 202         abort = passwd_abort(etime);
 203         if (!abort)
 204                 debug_bootkeys("key timeout\n");
 205
 206 #ifdef CONFIG_SILENT_CONSOLE
 207         if (abort)
 208                 gd->flags &= ~GD_FLG_SILENT;
 209 #endif
 210
 211         return abort;
 212 }
 213
 214 # else  /* !defined(CONFIG_AUTOBOOT_KEYED) */
 215
 216 #ifdef CONFIG_MENUKEY
 217 static int menukey;
 218 #endif
 219
 220 static int abortboot_normal(int bootdelay)
 221 {
 222         int abort = 0;
 223         unsigned long ts;
 224
 225 #ifdef CONFIG_MENUPROMPT
 226         printf(CONFIG_MENUPROMPT);
 227 #else
 228         if (bootdelay >= 0)
 229                 printf("Hit any key to stop autoboot: %2d ", bootdelay);
 230 #endif
 231
 232 #if defined CONFIG_ZERO_BOOTDELAY_CHECK
 233         /*
 234          * Check if key already pressed
 235          * Don't check if bootdelay < 0
 236          */
 237         if (bootdelay >= 0) {
 238                 if (tstc()) {   /* we got a key press   */
 239                         (void) getc();  /* consume input        */
 240                         puts("\b\b\b 0");
 241                         abort = 1;      /* don't auto boot      */
 242                 }
 243         }
 244 #endif
 245
 246         while ((bootdelay > 0) && (!abort)) {
 247                 --bootdelay;
 248                 /* delay 1000 ms */
 249                 ts = get_timer(0);
 250                 do {
 251                         if (tstc()) {   /* we got a key press   */
 252                                 abort  = 1;     /* don't auto boot      */
 253                                 bootdelay = 0;  /* no more delay        */
 254 # ifdef CONFIG_MENUKEY
 255                                 menukey = getc();
 256 # else
 257                                 (void) getc();  /* consume input        */
 258 # endif
 259                                 break;
 260                         }
 261                         udelay(10000);
 262                 } while (!abort && get_timer(ts) < 1000);
 263
 264                 printf("\b\b\b%2d ", bootdelay);
 265         }
 266
 267         putc('\n');
 268
 269 #ifdef CONFIG_SILENT_CONSOLE
 270         if (abort)
 271                 gd->flags &= ~GD_FLG_SILENT;
 272 #endif
 273
 274         return abort;
 275 }
 276 # endif /* CONFIG_AUTOBOOT_KEYED */
 277
 278 static int abortboot(int bootdelay)
 279 {
 280 #ifdef CONFIG_AUTOBOOT_KEYED
 281         return abortboot_keyed(bootdelay);
 282 #else
 283         return abortboot_normal(bootdelay);
 284 #endif
 285 }
 286
 287 static void process_fdt_options(const void *blob)
 288 {
 289 #if defined(CONFIG_OF_CONTROL)
 290         ulong addr;
 291
 292         /* Add an env variable to point to a kernel payload, if available */
 293         addr = fdtdec_get_config_int(gd->fdt_blob, "kernel-offset", 0);
 294         if (addr)
 295                 setenv_addr("kernaddr", (void *)(CONFIG_SYS_TEXT_BASE + addr));
 296
 297         /* Add an env variable to point to a root disk, if available */
 298         addr = fdtdec_get_config_int(gd->fdt_blob, "rootdisk-offset", 0);
 299         if (addr)
 300                 setenv_addr("rootaddr", (void *)(CONFIG_SYS_TEXT_BASE + addr));
 301 #endif /* CONFIG_OF_CONTROL */
 302 }
 303
 304 const char *bootdelay_process(void)
 305 {
 306         char *s;
 307         int bootdelay;
 308 #ifdef CONFIG_BOOTCOUNT_LIMIT
 309         unsigned long bootcount = 0;
 310         unsigned long bootlimit = 0;
 311 #endif /* CONFIG_BOOTCOUNT_LIMIT */
 312
 313 #ifdef CONFIG_BOOTCOUNT_LIMIT
 314         bootcount = bootcount_load();
 315         bootcount++;
 316         bootcount_store(bootcount);
 317         setenv_ulong("bootcount", bootcount);
 318         bootlimit = getenv_ulong("bootlimit", 10, 0);
 319 #endif /* CONFIG_BOOTCOUNT_LIMIT */
 320
 321         s = getenv("bootdelay");
 322         bootdelay = s ? (int)simple_strtol(s, NULL, 10) : CONFIG_BOOTDELAY;
 323
 324 #ifdef CONFIG_OF_CONTROL
 325         bootdelay = fdtdec_get_config_int(gd->fdt_blob, "bootdelay",
 326                         bootdelay);
 327 #endif
 328
 329         debug("### main_loop entered: bootdelay=%d\n\n", bootdelay);
 330
 331 #if defined(CONFIG_MENU_SHOW)
 332         bootdelay = menu_show(bootdelay);
 333 #endif
 334         bootretry_init_cmd_timeout();
 335
 336 #ifdef CONFIG_POST
 337         if (gd->flags & GD_FLG_POSTFAIL) {
 338                 s = getenv("failbootcmd");
 339         } else
 340 #endif /* CONFIG_POST */
 341 #ifdef CONFIG_BOOTCOUNT_LIMIT
 342         if (bootlimit && (bootcount > bootlimit)) {
 343                 printf("Warning: Bootlimit (%u) exceeded. Using altbootcmd.\n",
 344                        (unsigned)bootlimit);
 345                 s = getenv("altbootcmd");
 346         } else
 347 #endif /* CONFIG_BOOTCOUNT_LIMIT */
 348                 s = getenv("bootcmd");
 349
 350         process_fdt_options(gd->fdt_blob);
 351         stored_bootdelay = bootdelay;
 352
 353         return s;
 354 }
 355
 356 void autoboot_command(const char *s)
 357 {
 358         debug("### main_loop: bootcmd=\"%s\"\n", s ? s : "<UNDEFINED>");
 359
 360         if (stored_bootdelay != -1 && s && !abortboot(stored_bootdelay)) {
 361 #if defined(CONFIG_AUTOBOOT_KEYED) && !defined(CONFIG_AUTOBOOT_KEYED_CTRLC)
 362                 int prev = disable_ctrlc(1);    /* disable Control C checking */
 363 #endif
 364
 365                 run_command_list(s, -1, 0);
 366
 367 #if defined(CONFIG_AUTOBOOT_KEYED) && !defined(CONFIG_AUTOBOOT_KEYED_CTRLC)
 368                 disable_ctrlc(prev);    /* restore Control C checking */
 369 #endif
 370         }
 371
 372 #ifdef CONFIG_MENUKEY
 373         if (menukey == CONFIG_MENUKEY) {
 374                 s = getenv("menucmd");
 375                 if (s)
 376                         run_command_list(s, -1, 0);
 377         }
 378 #endif /* CONFIG_MENUKEY */
 379 }