env/common.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * (C) Copyright 2000-2010
   4  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   5  *
   6  * (C) Copyright 2001 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
   7  * Andreas Heppel <aheppel@sysgo.de>
   8  */
   9
  10 #include <common.h>
  11 #include <command.h>
  12 #include <environment.h>
  13 #include <linux/stddef.h>
  14 #include <search.h>
  15 #include <errno.h>
  16 #include <malloc.h>
  17
  18 DECLARE_GLOBAL_DATA_PTR;
  19
  20 /************************************************************************
  21  * Default settings to be used when no valid environment is found
  22  */
  23 #include <env_default.h>
  24
  25 struct hsearch_data env_htab = {
  26 #if CONFIG_IS_ENABLED(ENV_SUPPORT)
  27         /* defined in flags.c, only compile with ENV_SUPPORT */
  28         .change_ok = env_flags_validate,
  29 #endif
  30 };
  31
  32 /*
  33  * Read an environment variable as a boolean
  34  * Return -1 if variable does not exist (default to true)
  35  */
  36 int env_get_yesno(const char *var)
  37 {
  38         char *s = env_get(var);
  39
  40         if (s == NULL)
  41                 return -1;
  42         return (*s == '1' || *s == 'y' || *s == 'Y' || *s == 't' || *s == 'T') ?
  43                 1 : 0;
  44 }
  45
  46 /*
  47  * Look up the variable from the default environment
  48  */
  49 char *env_get_default(const char *name)
  50 {
  51         char *ret_val;
  52         unsigned long really_valid = gd->env_valid;
  53         unsigned long real_gd_flags = gd->flags;
  54
  55         /* Pretend that the image is bad. */
  56         gd->flags &= ~GD_FLG_ENV_READY;
  57         gd->env_valid = ENV_INVALID;
  58         ret_val = env_get(name);
  59         gd->env_valid = really_valid;
  60         gd->flags = real_gd_flags;
  61         return ret_val;
  62 }
  63
  64 void set_default_env(const char *s, int flags)
  65 {
  66         if (sizeof(default_environment) > ENV_SIZE) {
  67                 puts("*** Error - default environment is too large\n\n");
  68                 return;
  69         }
  70
  71         if (s) {
  72                 if ((flags & H_INTERACTIVE) == 0) {
  73                         printf("*** Warning - %s, "
  74                                 "using default environment\n\n", s);
  75                 } else {
  76                         puts(s);
  77                 }
  78         } else {
  79                 debug("Using default environment\n");
  80         }
  81
  82         if (himport_r(&env_htab, (char *)default_environment,
  83                         sizeof(default_environment), '\0', flags, 0,
  84                         0, NULL) == 0)
  85                 pr_err("## Error: Environment import failed: errno = %d\n",
  86                        errno);
  87
  88         gd->flags |= GD_FLG_ENV_READY;
  89         gd->flags |= GD_FLG_ENV_DEFAULT;
  90 }
  91
  92
  93 /* [re]set individual variables to their value in the default environment */
  94 int set_default_vars(int nvars, char * const vars[], int flags)
  95 {
  96         /*
  97          * Special use-case: import from default environment
  98          * (and use \0 as a separator)
  99          */
 100         flags |= H_NOCLEAR;
 101         return himport_r(&env_htab, (const char *)default_environment,
 102                                 sizeof(default_environment), '\0',
 103                                 flags, 0, nvars, vars);
 104 }
 105
 106 /*
 107  * Check if CRC is valid and (if yes) import the environment.
 108  * Note that "buf" may or may not be aligned.
 109  */
 110 int env_import(const char *buf, int check)
 111 {
 112         env_t *ep = (env_t *)buf;
 113
 114         if (check) {
 115                 uint32_t crc;
 116
 117                 memcpy(&crc, &ep->crc, sizeof(crc));
 118
 119                 if (crc32(0, ep->data, ENV_SIZE) != crc) {
 120                         set_default_env("bad CRC", 0);
 121                         return -ENOMSG; /* needed for env_load() */
 122                 }
 123         }
 124
 125         if (himport_r(&env_htab, (char *)ep->data, ENV_SIZE, '\0', 0, 0,
 126                         0, NULL)) {
 127                 gd->flags |= GD_FLG_ENV_READY;
 128                 return 0;
 129         }
 130
 131         pr_err("Cannot import environment: errno = %d\n", errno);
 132
 133         set_default_env("import failed", 0);
 134
 135         return -EIO;
 136 }
 137
 138 #ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
 139 static unsigned char env_flags;
 140
 141 int env_import_redund(const char *buf1, int buf1_read_fail,
 142                       const char *buf2, int buf2_read_fail)
 143 {
 144         int crc1_ok, crc2_ok;
 145         env_t *ep, *tmp_env1, *tmp_env2;
 146
 147         tmp_env1 = (env_t *)buf1;
 148         tmp_env2 = (env_t *)buf2;
 149
 150         if (buf1_read_fail && buf2_read_fail) {
 151                 puts("*** Error - No Valid Environment Area found\n");
 152         } else if (buf1_read_fail || buf2_read_fail) {
 153                 puts("*** Warning - some problems detected ");
 154                 puts("reading environment; recovered successfully\n");
 155         }
 156
 157         if (buf1_read_fail && buf2_read_fail) {
 158                 set_default_env("bad env area", 0);
 159                 return -EIO;
 160         } else if (!buf1_read_fail && buf2_read_fail) {
 161                 gd->env_valid = ENV_VALID;
 162                 return env_import((char *)tmp_env1, 1);
 163         } else if (buf1_read_fail && !buf2_read_fail) {
 164                 gd->env_valid = ENV_REDUND;
 165                 return env_import((char *)tmp_env2, 1);
 166         }
 167
 168         crc1_ok = crc32(0, tmp_env1->data, ENV_SIZE) ==
 169                         tmp_env1->crc;
 170         crc2_ok = crc32(0, tmp_env2->data, ENV_SIZE) ==
 171                         tmp_env2->crc;
 172
 173         if (!crc1_ok && !crc2_ok) {
 174                 set_default_env("bad CRC", 0);
 175                 return -ENOMSG; /* needed for env_load() */
 176         } else if (crc1_ok && !crc2_ok) {
 177                 gd->env_valid = ENV_VALID;
 178         } else if (!crc1_ok && crc2_ok) {
 179                 gd->env_valid = ENV_REDUND;
 180         } else {
 181                 /* both ok - check serial */
 182                 if (tmp_env1->flags == 255 && tmp_env2->flags == 0)
 183                         gd->env_valid = ENV_REDUND;
 184                 else if (tmp_env2->flags == 255 && tmp_env1->flags == 0)
 185                         gd->env_valid = ENV_VALID;
 186                 else if (tmp_env1->flags > tmp_env2->flags)
 187                         gd->env_valid = ENV_VALID;
 188                 else if (tmp_env2->flags > tmp_env1->flags)
 189                         gd->env_valid = ENV_REDUND;
 190                 else /* flags are equal - almost impossible */
 191                         gd->env_valid = ENV_VALID;
 192         }
 193
 194         if (gd->env_valid == ENV_VALID)
 195                 ep = tmp_env1;
 196         else
 197                 ep = tmp_env2;
 198
 199         env_flags = ep->flags;
 200         return env_import((char *)ep, 0);
 201 }
 202 #endif /* CONFIG_SYS_REDUNDAND_ENVIRONMENT */
 203
 204 /* Export the environment and generate CRC for it. */
 205 int env_export(env_t *env_out)
 206 {
 207         char *res;
 208         ssize_t len;
 209
 210         res = (char *)env_out->data;
 211         len = hexport_r(&env_htab, '\0', 0, &res, ENV_SIZE, 0, NULL);
 212         if (len < 0) {
 213                 pr_err("Cannot export environment: errno = %d\n", errno);
 214                 return 1;
 215         }
 216
 217         env_out->crc = crc32(0, env_out->data, ENV_SIZE);
 218
 219 #ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
 220         env_out->flags = ++env_flags; /* increase the serial */
 221 #endif
 222
 223         return 0;
 224 }
 225
 226 void env_relocate(void)
 227 {
 228 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
 229         env_reloc();
 230         env_fix_drivers();
 231
 232         if (env_htab.change_ok)
 233                 env_htab.change_ok += gd->reloc_off;
 234 #endif
 235         if (gd->env_valid == ENV_INVALID) {
 236 #if defined(CONFIG_ENV_IS_NOWHERE) || defined(CONFIG_SPL_BUILD)
 237                 /* Environment not changable */
 238                 set_default_env(NULL, 0);
 239 #else
 240                 bootstage_error(BOOTSTAGE_ID_NET_CHECKSUM);
 241                 set_default_env("bad CRC", 0);
 242 #endif
 243         } else {
 244                 env_load();
 245         }
 246 }
 247
 248 #ifdef CONFIG_AUTO_COMPLETE
 249 int env_complete(char *var, int maxv, char *cmdv[], int bufsz, char *buf,
 250                  bool dollar_comp)
 251 {
 252         ENTRY *match;
 253         int found, idx;
 254
 255         if (dollar_comp) {
 256                 /*
 257                  * When doing $ completion, the first character should
 258                  * obviously be a '$'.
 259                  */
 260                 if (var[0] != '$')
 261                         return 0;
 262
 263                 var++;
 264
 265                 /*
 266                  * The second one, if present, should be a '{', as some
 267                  * configuration of the u-boot shell expand ${var} but not
 268                  * $var.
 269                  */
 270                 if (var[0] == '{')
 271                         var++;
 272                 else if (var[0] != '\0')
 273                         return 0;
 274         }
 275
 276         idx = 0;
 277         found = 0;
 278         cmdv[0] = NULL;
 279
 280
 281         while ((idx = hmatch_r(var, idx, &match, &env_htab))) {
 282                 int vallen = strlen(match->key) + 1;
 283
 284                 if (found >= maxv - 2 ||
 285                     bufsz < vallen + (dollar_comp ? 3 : 0))
 286                         break;
 287
 288                 cmdv[found++] = buf;
 289
 290                 /* Add the '${' prefix to each var when doing $ completion. */
 291                 if (dollar_comp) {
 292                         strcpy(buf, "${");
 293                         buf += 2;
 294                         bufsz -= 3;
 295                 }
 296
 297                 memcpy(buf, match->key, vallen);
 298                 buf += vallen;
 299                 bufsz -= vallen;
 300
 301                 if (dollar_comp) {
 302                         /*
 303                          * This one is a bit odd: vallen already contains the
 304                          * '\0' character but we need to add the '}' suffix,
 305                          * hence the buf - 1 here. strcpy() will add the '\0'
 306                          * character just after '}'. buf is then incremented
 307                          * to account for the extra '}' we just added.
 308                          */
 309                         strcpy(buf - 1, "}");
 310                         buf++;
 311                 }
 312         }
 313
 314         qsort(cmdv, found, sizeof(cmdv[0]), strcmp_compar);
 315
 316         if (idx)
 317                 cmdv[found++] = dollar_comp ? "${...}" : "...";
 318
 319         cmdv[found] = NULL;
 320         return found;
 321 }
 322 #endif