1 /* 2 * (C) Copyright 2000-2010 3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4 * 5 * (C) Copyright 2001 Sysgo Real-Time Solutions, GmbH <www.elinos.com> 6 * Andreas Heppel <aheppel@sysgo.de> 7 * 8 * SPDX-License-Identifier: GPL-2.0+ 9 */ 10 11 #include <common.h> 12 #include <command.h> 13 #include <environment.h> 14 #include <linux/stddef.h> 15 #include <search.h> 16 #include <errno.h> 17 #include <malloc.h> 18 19 DECLARE_GLOBAL_DATA_PTR; 20 21 /************************************************************************ 22 * Default settings to be used when no valid environment is found 23 */ 24 #include <env_default.h> 25 26 struct hsearch_data env_htab = { 27 .change_ok = env_flags_validate, 28 }; 29 30 __weak uchar env_get_char_spec(int index) 31 { 32 return *((uchar *)(gd->env_addr + index)); 33 } 34 35 static uchar env_get_char_init(int index) 36 { 37 /* if crc was bad, use the default environment */ 38 if (gd->env_valid) 39 return env_get_char_spec(index); 40 else 41 return default_environment[index]; 42 } 43 44 static uchar env_get_char_memory(int index) 45 { 46 if (gd->env_valid) 47 return *(uchar *)(gd->env_addr + index); 48 else 49 return default_environment[index]; 50 } 51 52 uchar env_get_char(int index) 53 { 54 /* if relocated to RAM */ 55 if (gd->flags & GD_FLG_RELOC) 56 return env_get_char_memory(index); 57 else 58 return env_get_char_init(index); 59 } 60 61 /* 62 * Read an environment variable as a boolean 63 * Return -1 if variable does not exist (default to true) 64 */ 65 int getenv_yesno(const char *var) 66 { 67 char *s = getenv(var); 68 69 if (s == NULL) 70 return -1; 71 return (*s == '1' || *s == 'y' || *s == 'Y' || *s == 't' || *s == 'T') ? 72 1 : 0; 73 } 74 75 /* 76 * Look up the variable from the default environment 77 */ 78 char *getenv_default(const char *name) 79 { 80 char *ret_val; 81 unsigned long really_valid = gd->env_valid; 82 unsigned long real_gd_flags = gd->flags; 83 84 /* Pretend that the image is bad. */ 85 gd->flags &= ~GD_FLG_ENV_READY; 86 gd->env_valid = 0; 87 ret_val = getenv(name); 88 gd->env_valid = really_valid; 89 gd->flags = real_gd_flags; 90 return ret_val; 91 } 92 93 void set_default_env(const char *s) 94 { 95 int flags = 0; 96 97 if (sizeof(default_environment) > ENV_SIZE) { 98 puts("*** Error - default environment is too large\n\n"); 99 return; 100 } 101 102 if (s) { 103 if (*s == '!') { 104 printf("*** Warning - %s, " 105 "using default environment\n\n", 106 s + 1); 107 } else { 108 flags = H_INTERACTIVE; 109 puts(s); 110 } 111 } else { 112 puts("Using default environment\n\n"); 113 } 114 115 if (himport_r(&env_htab, (char *)default_environment, 116 sizeof(default_environment), '\0', flags, 0, 117 0, NULL) == 0) 118 error("Environment import failed: errno = %d\n", errno); 119 120 gd->flags |= GD_FLG_ENV_READY; 121 gd->flags |= GD_FLG_ENV_DEFAULT; 122 } 123 124 125 /* [re]set individual variables to their value in the default environment */ 126 int set_default_vars(int nvars, char * const vars[]) 127 { 128 /* 129 * Special use-case: import from default environment 130 * (and use \0 as a separator) 131 */ 132 return himport_r(&env_htab, (const char *)default_environment, 133 sizeof(default_environment), '\0', 134 H_NOCLEAR | H_INTERACTIVE, 0, nvars, vars); 135 } 136 137 #ifdef CONFIG_ENV_AES 138 #include <uboot_aes.h> 139 /** 140 * env_aes_cbc_get_key() - Get AES-128-CBC key for the environment 141 * 142 * This function shall return 16-byte array containing AES-128 key used 143 * to encrypt and decrypt the environment. This function must be overridden 144 * by the implementer as otherwise the environment encryption will not 145 * work. 146 */ 147 __weak uint8_t *env_aes_cbc_get_key(void) 148 { 149 return NULL; 150 } 151 152 static int env_aes_cbc_crypt(env_t *env, const int enc) 153 { 154 unsigned char *data = env->data; 155 uint8_t *key; 156 uint8_t key_exp[AES_EXPAND_KEY_LENGTH]; 157 uint32_t aes_blocks; 158 159 key = env_aes_cbc_get_key(); 160 if (!key) 161 return -EINVAL; 162 163 /* First we expand the key. */ 164 aes_expand_key(key, key_exp); 165 166 /* Calculate the number of AES blocks to encrypt. */ 167 aes_blocks = ENV_SIZE / AES_KEY_LENGTH; 168 169 if (enc) 170 aes_cbc_encrypt_blocks(key_exp, data, data, aes_blocks); 171 else 172 aes_cbc_decrypt_blocks(key_exp, data, data, aes_blocks); 173 174 return 0; 175 } 176 #else 177 static inline int env_aes_cbc_crypt(env_t *env, const int enc) 178 { 179 return 0; 180 } 181 #endif 182 183 /* 184 * Check if CRC is valid and (if yes) import the environment. 185 * Note that "buf" may or may not be aligned. 186 */ 187 int env_import(const char *buf, int check) 188 { 189 env_t *ep = (env_t *)buf; 190 int ret; 191 192 if (check) { 193 uint32_t crc; 194 195 memcpy(&crc, &ep->crc, sizeof(crc)); 196 197 if (crc32(0, ep->data, ENV_SIZE) != crc) { 198 set_default_env("!bad CRC"); 199 return 0; 200 } 201 } 202 203 /* Decrypt the env if desired. */ 204 ret = env_aes_cbc_crypt(ep, 0); 205 if (ret) { 206 error("Failed to decrypt env!\n"); 207 set_default_env("!import failed"); 208 return ret; 209 } 210 211 if (himport_r(&env_htab, (char *)ep->data, ENV_SIZE, '\0', 0, 0, 212 0, NULL)) { 213 gd->flags |= GD_FLG_ENV_READY; 214 return 1; 215 } 216 217 error("Cannot import environment: errno = %d\n", errno); 218 219 set_default_env("!import failed"); 220 221 return 0; 222 } 223 224 #ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT 225 static unsigned char env_flags; 226 227 int env_import_redund(const char *buf1, const char *buf2) 228 { 229 int crc1_ok, crc2_ok; 230 env_t *ep, *tmp_env1, *tmp_env2; 231 232 tmp_env1 = (env_t *)buf1; 233 tmp_env2 = (env_t *)buf2; 234 235 crc1_ok = crc32(0, tmp_env1->data, ENV_SIZE) == 236 tmp_env1->crc; 237 crc2_ok = crc32(0, tmp_env2->data, ENV_SIZE) == 238 tmp_env2->crc; 239 240 if (!crc1_ok && !crc2_ok) { 241 set_default_env("!bad CRC"); 242 return 0; 243 } else if (crc1_ok && !crc2_ok) { 244 gd->env_valid = 1; 245 } else if (!crc1_ok && crc2_ok) { 246 gd->env_valid = 2; 247 } else { 248 /* both ok - check serial */ 249 if (tmp_env1->flags == 255 && tmp_env2->flags == 0) 250 gd->env_valid = 2; 251 else if (tmp_env2->flags == 255 && tmp_env1->flags == 0) 252 gd->env_valid = 1; 253 else if (tmp_env1->flags > tmp_env2->flags) 254 gd->env_valid = 1; 255 else if (tmp_env2->flags > tmp_env1->flags) 256 gd->env_valid = 2; 257 else /* flags are equal - almost impossible */ 258 gd->env_valid = 1; 259 } 260 261 if (gd->env_valid == 1) 262 ep = tmp_env1; 263 else 264 ep = tmp_env2; 265 266 env_flags = ep->flags; 267 return env_import((char *)ep, 0); 268 } 269 #endif /* CONFIG_SYS_REDUNDAND_ENVIRONMENT */ 270 271 /* Export the environment and generate CRC for it. */ 272 int env_export(env_t *env_out) 273 { 274 char *res; 275 ssize_t len; 276 int ret; 277 278 res = (char *)env_out->data; 279 len = hexport_r(&env_htab, '\0', 0, &res, ENV_SIZE, 0, NULL); 280 if (len < 0) { 281 error("Cannot export environment: errno = %d\n", errno); 282 return 1; 283 } 284 285 /* Encrypt the env if desired. */ 286 ret = env_aes_cbc_crypt(env_out, 1); 287 if (ret) 288 return ret; 289 290 env_out->crc = crc32(0, env_out->data, ENV_SIZE); 291 292 #ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT 293 env_out->flags = ++env_flags; /* increase the serial */ 294 #endif 295 296 return 0; 297 } 298 299 void env_relocate(void) 300 { 301 #if defined(CONFIG_NEEDS_MANUAL_RELOC) 302 env_reloc(); 303 env_htab.change_ok += gd->reloc_off; 304 #endif 305 if (gd->env_valid == 0) { 306 #if defined(CONFIG_ENV_IS_NOWHERE) || defined(CONFIG_SPL_BUILD) 307 /* Environment not changable */ 308 set_default_env(NULL); 309 #else 310 bootstage_error(BOOTSTAGE_ID_NET_CHECKSUM); 311 set_default_env("!bad CRC"); 312 #endif 313 } else { 314 env_relocate_spec(); 315 } 316 } 317 318 #if defined(CONFIG_AUTO_COMPLETE) && !defined(CONFIG_SPL_BUILD) 319 int env_complete(char *var, int maxv, char *cmdv[], int bufsz, char *buf) 320 { 321 ENTRY *match; 322 int found, idx; 323 324 idx = 0; 325 found = 0; 326 cmdv[0] = NULL; 327 328 while ((idx = hmatch_r(var, idx, &match, &env_htab))) { 329 int vallen = strlen(match->key) + 1; 330 331 if (found >= maxv - 2 || bufsz < vallen) 332 break; 333 334 cmdv[found++] = buf; 335 memcpy(buf, match->key, vallen); 336 buf += vallen; 337 bufsz -= vallen; 338 } 339 340 qsort(cmdv, found, sizeof(cmdv[0]), strcmp_compar); 341 342 if (idx) 343 cmdv[found++] = "..."; 344 345 cmdv[found] = NULL; 346 return found; 347 } 348 #endif 349