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, int flags)
  62 {
  63         if (sizeof(default_environment) > ENV_SIZE) {
  64                 puts("*** Error - default environment is too large\n\n");
  65                 return;
  66         }
  67
  68         if (s) {
  69                 if ((flags & H_INTERACTIVE) == 0) {
  70                         printf("*** Warning - %s, "
  71                                 "using default environment\n\n", s);
  72                 } else {
  73                         puts(s);
  74                 }
  75         } else {
  76                 debug("Using default environment\n");
  77         }
  78
  79         if (himport_r(&env_htab, (char *)default_environment,
  80                         sizeof(default_environment), '\0', flags, 0,
  81                         0, NULL) == 0)
  82                 pr_err("## Error: Environment import failed: errno = %d\n",
  83                        errno);
  84
  85         gd->flags |= GD_FLG_ENV_READY;
  86         gd->flags |= GD_FLG_ENV_DEFAULT;
  87 }
  88
  89
  90 /* [re]set individual variables to their value in the default environment */
  91 int set_default_vars(int nvars, char * const vars[], int flags)
  92 {
  93         /*
  94          * Special use-case: import from default environment
  95          * (and use \0 as a separator)
  96          */
  97         flags |= H_NOCLEAR;
  98         return himport_r(&env_htab, (const char *)default_environment,
  99                                 sizeof(default_environment), '\0',
 100                                 flags, 0, nvars, vars);
 101 }
 102
 103 /*
 104  * Check if CRC is valid and (if yes) import the environment.
 105  * Note that "buf" may or may not be aligned.
 106  */
 107 int env_import(const char *buf, int check)
 108 {
 109         env_t *ep = (env_t *)buf;
 110
 111         if (check) {
 112                 uint32_t crc;
 113
 114                 memcpy(&crc, &ep->crc, sizeof(crc));
 115
 116                 if (crc32(0, ep->data, ENV_SIZE) != crc) {
 117                         set_default_env("bad CRC", 0);
 118                         return -EIO;
 119                 }
 120         }
 121
 122         if (himport_r(&env_htab, (char *)ep->data, ENV_SIZE, '\0', 0, 0,
 123                         0, NULL)) {
 124                 gd->flags |= GD_FLG_ENV_READY;
 125                 return 0;
 126         }
 127
 128         pr_err("Cannot import environment: errno = %d\n", errno);
 129
 130         set_default_env("import failed", 0);
 131
 132         return -EIO;
 133 }
 134
 135 #ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
 136 static unsigned char env_flags;
 137
 138 int env_import_redund(const char *buf1, int buf1_read_fail,
 139                       const char *buf2, int buf2_read_fail)
 140 {
 141         int crc1_ok, crc2_ok;
 142         env_t *ep, *tmp_env1, *tmp_env2;
 143
 144         tmp_env1 = (env_t *)buf1;
 145         tmp_env2 = (env_t *)buf2;
 146
 147         if (buf1_read_fail && buf2_read_fail) {
 148                 puts("*** Error - No Valid Environment Area found\n");
 149         } else if (buf1_read_fail || buf2_read_fail) {
 150                 puts("*** Warning - some problems detected ");
 151                 puts("reading environment; recovered successfully\n");
 152         }
 153
 154         if (buf1_read_fail && buf2_read_fail) {
 155                 set_default_env("bad env area", 0);
 156                 return -EIO;
 157         } else if (!buf1_read_fail && buf2_read_fail) {
 158                 gd->env_valid = ENV_VALID;
 159                 return env_import((char *)tmp_env1, 1);
 160         } else if (buf1_read_fail && !buf2_read_fail) {
 161                 gd->env_valid = ENV_REDUND;
 162                 return env_import((char *)tmp_env2, 1);
 163         }
 164
 165         crc1_ok = crc32(0, tmp_env1->data, ENV_SIZE) ==
 166                         tmp_env1->crc;
 167         crc2_ok = crc32(0, tmp_env2->data, ENV_SIZE) ==
 168                         tmp_env2->crc;
 169
 170         if (!crc1_ok && !crc2_ok) {
 171                 set_default_env("bad CRC", 0);
 172                 return -EIO;
 173         } else if (crc1_ok && !crc2_ok) {
 174                 gd->env_valid = ENV_VALID;
 175         } else if (!crc1_ok && crc2_ok) {
 176                 gd->env_valid = ENV_REDUND;
 177         } else {
 178                 /* both ok - check serial */
 179                 if (tmp_env1->flags == 255 && tmp_env2->flags == 0)
 180                         gd->env_valid = ENV_REDUND;
 181                 else if (tmp_env2->flags == 255 && tmp_env1->flags == 0)
 182                         gd->env_valid = ENV_VALID;
 183                 else if (tmp_env1->flags > tmp_env2->flags)
 184                         gd->env_valid = ENV_VALID;
 185                 else if (tmp_env2->flags > tmp_env1->flags)
 186                         gd->env_valid = ENV_REDUND;
 187                 else /* flags are equal - almost impossible */
 188                         gd->env_valid = ENV_VALID;
 189         }
 190
 191         if (gd->env_valid == ENV_VALID)
 192                 ep = tmp_env1;
 193         else
 194                 ep = tmp_env2;
 195
 196         env_flags = ep->flags;
 197         return env_import((char *)ep, 0);
 198 }
 199 #endif /* CONFIG_SYS_REDUNDAND_ENVIRONMENT */
 200
 201 /* Export the environment and generate CRC for it. */
 202 int env_export(env_t *env_out)
 203 {
 204         char *res;
 205         ssize_t len;
 206
 207         res = (char *)env_out->data;
 208         len = hexport_r(&env_htab, '\0', 0, &res, ENV_SIZE, 0, NULL);
 209         if (len < 0) {
 210                 pr_err("Cannot export environment: errno = %d\n", errno);
 211                 return 1;
 212         }
 213
 214         env_out->crc = crc32(0, env_out->data, ENV_SIZE);
 215
 216 #ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
 217         env_out->flags = ++env_flags; /* increase the serial */
 218 #endif
 219
 220         return 0;
 221 }
 222
 223 void env_relocate(void)
 224 {
 225 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
 226         env_reloc();
 227         env_fix_drivers();
 228         env_htab.change_ok += gd->reloc_off;
 229 #endif
 230         if (gd->env_valid == ENV_INVALID) {
 231 #if defined(CONFIG_ENV_IS_NOWHERE) || defined(CONFIG_SPL_BUILD)
 232                 /* Environment not changable */
 233                 set_default_env(NULL, 0);
 234 #else
 235                 bootstage_error(BOOTSTAGE_ID_NET_CHECKSUM);
 236                 set_default_env("bad CRC", 0);
 237 #endif
 238         } else {
 239                 env_load();
 240         }
 241 }
 242
 243 #if defined(CONFIG_AUTO_COMPLETE) && !defined(CONFIG_SPL_BUILD)
 244 int env_complete(char *var, int maxv, char *cmdv[], int bufsz, char *buf)
 245 {
 246         ENTRY *match;
 247         int found, idx;
 248
 249         idx = 0;
 250         found = 0;
 251         cmdv[0] = NULL;
 252
 253         while ((idx = hmatch_r(var, idx, &match, &env_htab))) {
 254                 int vallen = strlen(match->key) + 1;
 255
 256                 if (found >= maxv - 2 || bufsz < vallen)
 257                         break;
 258
 259                 cmdv[found++] = buf;
 260                 memcpy(buf, match->key, vallen);
 261                 buf += vallen;
 262                 bufsz -= vallen;
 263         }
 264
 265         qsort(cmdv, found, sizeof(cmdv[0]), strcmp_compar);
 266
 267         if (idx)
 268                 cmdv[found++] = "...";
 269
 270         cmdv[found] = NULL;
 271         return found;
 272 }
 273 #endif