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         .change_ok = env_flags_validate,
  27 };
  28
  29 /*
  30  * Read an environment variable as a boolean
  31  * Return -1 if variable does not exist (default to true)
  32  */
  33 int env_get_yesno(const char *var)
  34 {
  35         char *s = env_get(var);
  36
  37         if (s == NULL)
  38                 return -1;
  39         return (*s == '1' || *s == 'y' || *s == 'Y' || *s == 't' || *s == 'T') ?
  40                 1 : 0;
  41 }
  42
  43 /*
  44  * Look up the variable from the default environment
  45  */
  46 char *env_get_default(const char *name)
  47 {
  48         char *ret_val;
  49         unsigned long really_valid = gd->env_valid;
  50         unsigned long real_gd_flags = gd->flags;
  51
  52         /* Pretend that the image is bad. */
  53         gd->flags &= ~GD_FLG_ENV_READY;
  54         gd->env_valid = ENV_INVALID;
  55         ret_val = env_get(name);
  56         gd->env_valid = really_valid;
  57         gd->flags = real_gd_flags;
  58         return ret_val;
  59 }
  60
  61 void set_default_env(const char *s)
  62 {
  63         int flags = 0;
  64
  65         if (sizeof(default_environment) > ENV_SIZE) {
  66                 puts("*** Error - default environment is too large\n\n");
  67                 return;
  68         }
  69
  70         if (s) {
  71                 if (*s == '!') {
  72                         printf("*** Warning - %s, "
  73                                 "using default environment\n\n",
  74                                 s + 1);
  75                 } else {
  76                         flags = H_INTERACTIVE;
  77                         puts(s);
  78                 }
  79         } else {
  80                 debug("Using default environment\n");
  81         }
  82
  83         if (himport_r(&env_htab, (char *)default_environment,
  84                         sizeof(default_environment), '\0', flags, 0,
  85                         0, NULL) == 0)
  86                 pr_err("Environment import failed: errno = %d\n", 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[])
  95 {
  96         /*
  97          * Special use-case: import from default environment
  98          * (and use \0 as a separator)
  99          */
 100         return himport_r(&env_htab, (const char *)default_environment,
 101                                 sizeof(default_environment), '\0',
 102                                 H_NOCLEAR | H_INTERACTIVE, 0, nvars, vars);
 103 }
 104
 105 /*
 106  * Check if CRC is valid and (if yes) import the environment.
 107  * Note that "buf" may or may not be aligned.
 108  */
 109 int env_import(const char *buf, int check)
 110 {
 111         env_t *ep = (env_t *)buf;
 112
 113         if (check) {
 114                 uint32_t crc;
 115
 116                 memcpy(&crc, &ep->crc, sizeof(crc));
 117
 118                 if (crc32(0, ep->data, ENV_SIZE) != crc) {
 119                         set_default_env("!bad CRC");
 120                         return -EIO;
 121                 }
 122         }
 123
 124         if (himport_r(&env_htab, (char *)ep->data, ENV_SIZE, '\0', 0, 0,
 125                         0, NULL)) {
 126                 gd->flags |= GD_FLG_ENV_READY;
 127                 return 0;
 128         }
 129
 130         pr_err("Cannot import environment: errno = %d\n", errno);
 131
 132         set_default_env("!import failed");
 133
 134         return -EIO;
 135 }
 136
 137 #ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
 138 static unsigned char env_flags;
 139
 140 int env_import_redund(const char *buf1, int buf1_read_fail,
 141                       const char *buf2, int buf2_read_fail)
 142 {
 143         int crc1_ok, crc2_ok;
 144         env_t *ep, *tmp_env1, *tmp_env2;
 145
 146         tmp_env1 = (env_t *)buf1;
 147         tmp_env2 = (env_t *)buf2;
 148
 149         if (buf1_read_fail && buf2_read_fail) {
 150                 puts("*** Error - No Valid Environment Area found\n");
 151         } else if (buf1_read_fail || buf2_read_fail) {
 152                 puts("*** Warning - some problems detected ");
 153                 puts("reading environment; recovered successfully\n");
 154         }
 155
 156         if (buf1_read_fail && buf2_read_fail) {
 157                 set_default_env("!bad env area");
 158                 return -EIO;
 159         } else if (!buf1_read_fail && buf2_read_fail) {
 160                 gd->env_valid = ENV_VALID;
 161                 return env_import((char *)tmp_env1, 1);
 162         } else if (buf1_read_fail && !buf2_read_fail) {
 163                 gd->env_valid = ENV_REDUND;
 164                 return env_import((char *)tmp_env2, 1);
 165         }
 166
 167         crc1_ok = crc32(0, tmp_env1->data, ENV_SIZE) ==
 168                         tmp_env1->crc;
 169         crc2_ok = crc32(0, tmp_env2->data, ENV_SIZE) ==
 170                         tmp_env2->crc;
 171
 172         if (!crc1_ok && !crc2_ok) {
 173                 set_default_env("!bad CRC");
 174                 return -EIO;
 175         } else if (crc1_ok && !crc2_ok) {
 176                 gd->env_valid = ENV_VALID;
 177         } else if (!crc1_ok && crc2_ok) {
 178                 gd->env_valid = ENV_REDUND;
 179         } else {
 180                 /* both ok - check serial */
 181                 if (tmp_env1->flags == 255 && tmp_env2->flags == 0)
 182                         gd->env_valid = ENV_REDUND;
 183                 else if (tmp_env2->flags == 255 && tmp_env1->flags == 0)
 184                         gd->env_valid = ENV_VALID;
 185                 else if (tmp_env1->flags > tmp_env2->flags)
 186                         gd->env_valid = ENV_VALID;
 187                 else if (tmp_env2->flags > tmp_env1->flags)
 188                         gd->env_valid = ENV_REDUND;
 189                 else /* flags are equal - almost impossible */
 190                         gd->env_valid = ENV_VALID;
 191         }
 192
 193         if (gd->env_valid == ENV_VALID)
 194                 ep = tmp_env1;
 195         else
 196                 ep = tmp_env2;
 197
 198         env_flags = ep->flags;
 199         return env_import((char *)ep, 0);
 200 }
 201 #endif /* CONFIG_SYS_REDUNDAND_ENVIRONMENT */
 202
 203 /* Export the environment and generate CRC for it. */
 204 int env_export(env_t *env_out)
 205 {
 206         char *res;
 207         ssize_t len;
 208
 209         res = (char *)env_out->data;
 210         len = hexport_r(&env_htab, '\0', 0, &res, ENV_SIZE, 0, NULL);
 211         if (len < 0) {
 212                 pr_err("Cannot export environment: errno = %d\n", errno);
 213                 return 1;
 214         }
 215
 216         env_out->crc = crc32(0, env_out->data, ENV_SIZE);
 217
 218 #ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
 219         env_out->flags = ++env_flags; /* increase the serial */
 220 #endif
 221
 222         return 0;
 223 }
 224
 225 void env_relocate(void)
 226 {
 227 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
 228         env_reloc();
 229         env_fix_drivers();
 230         env_htab.change_ok += gd->reloc_off;
 231 #endif
 232         if (gd->env_valid == ENV_INVALID) {
 233 #if defined(CONFIG_ENV_IS_NOWHERE) || defined(CONFIG_SPL_BUILD)
 234                 /* Environment not changable */
 235                 set_default_env(NULL);
 236 #else
 237                 bootstage_error(BOOTSTAGE_ID_NET_CHECKSUM);
 238                 set_default_env("!bad CRC");
 239 #endif
 240         } else {
 241                 env_load();
 242         }
 243 }
 244
 245 #if defined(CONFIG_AUTO_COMPLETE) && !defined(CONFIG_SPL_BUILD)
 246 int env_complete(char *var, int maxv, char *cmdv[], int bufsz, char *buf)
 247 {
 248         ENTRY *match;
 249         int found, idx;
 250
 251         idx = 0;
 252         found = 0;
 253         cmdv[0] = NULL;
 254
 255         while ((idx = hmatch_r(var, idx, &match, &env_htab))) {
 256                 int vallen = strlen(match->key) + 1;
 257
 258                 if (found >= maxv - 2 || bufsz < vallen)
 259                         break;
 260
 261                 cmdv[found++] = buf;
 262                 memcpy(buf, match->key, vallen);
 263                 buf += vallen;
 264                 bufsz -= vallen;
 265         }
 266
 267         qsort(cmdv, found, sizeof(cmdv[0]), strcmp_compar);
 268
 269         if (idx)
 270                 cmdv[found++] = "...";
 271
 272         cmdv[found] = NULL;
 273         return found;
 274 }
 275 #endif