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_memory(int index) 36 { 37 return *(uchar *)(gd->env_addr + index); 38 } 39 40 uchar env_get_char(int index) 41 { 42 /* if env is not set up, or crc was bad, use the default environment */ 43 if (!gd->env_valid) 44 return default_environment[index]; 45 else if (gd->flags & GD_FLG_RELOC) /* if relocated to RAM */ 46 return env_get_char_memory(index); 47 else 48 return env_get_char_spec(index); 49 } 50 51 /* 52 * Read an environment variable as a boolean 53 * Return -1 if variable does not exist (default to true) 54 */ 55 int getenv_yesno(const char *var) 56 { 57 char *s = getenv(var); 58 59 if (s == NULL) 60 return -1; 61 return (*s == '1' || *s == 'y' || *s == 'Y' || *s == 't' || *s == 'T') ? 62 1 : 0; 63 } 64 65 /* 66 * Look up the variable from the default environment 67 */ 68 char *getenv_default(const char *name) 69 { 70 char *ret_val; 71 unsigned long really_valid = gd->env_valid; 72 unsigned long real_gd_flags = gd->flags; 73 74 /* Pretend that the image is bad. */ 75 gd->flags &= ~GD_FLG_ENV_READY; 76 gd->env_valid = 0; 77 ret_val = getenv(name); 78 gd->env_valid = really_valid; 79 gd->flags = real_gd_flags; 80 return ret_val; 81 } 82 83 void set_default_env(const char *s) 84 { 85 int flags = 0; 86 87 if (sizeof(default_environment) > ENV_SIZE) { 88 puts("*** Error - default environment is too large\n\n"); 89 return; 90 } 91 92 if (s) { 93 if (*s == '!') { 94 printf("*** Warning - %s, " 95 "using default environment\n\n", 96 s + 1); 97 } else { 98 flags = H_INTERACTIVE; 99 puts(s); 100 } 101 } else { 102 puts("Using default environment\n\n"); 103 } 104 105 if (himport_r(&env_htab, (char *)default_environment, 106 sizeof(default_environment), '\0', flags, 0, 107 0, NULL) == 0) 108 error("Environment import failed: errno = %d\n", errno); 109 110 gd->flags |= GD_FLG_ENV_READY; 111 gd->flags |= GD_FLG_ENV_DEFAULT; 112 } 113 114 115 /* [re]set individual variables to their value in the default environment */ 116 int set_default_vars(int nvars, char * const vars[]) 117 { 118 /* 119 * Special use-case: import from default environment 120 * (and use \0 as a separator) 121 */ 122 return himport_r(&env_htab, (const char *)default_environment, 123 sizeof(default_environment), '\0', 124 H_NOCLEAR | H_INTERACTIVE, 0, nvars, vars); 125 } 126 127 #ifdef CONFIG_ENV_AES 128 #include <uboot_aes.h> 129 /** 130 * env_aes_cbc_get_key() - Get AES-128-CBC key for the environment 131 * 132 * This function shall return 16-byte array containing AES-128 key used 133 * to encrypt and decrypt the environment. This function must be overridden 134 * by the implementer as otherwise the environment encryption will not 135 * work. 136 */ 137 __weak uint8_t *env_aes_cbc_get_key(void) 138 { 139 return NULL; 140 } 141 142 static int env_aes_cbc_crypt(env_t *env, const int enc) 143 { 144 unsigned char *data = env->data; 145 uint8_t *key; 146 uint8_t key_exp[AES_EXPAND_KEY_LENGTH]; 147 uint32_t aes_blocks; 148 149 key = env_aes_cbc_get_key(); 150 if (!key) 151 return -EINVAL; 152 153 /* First we expand the key. */ 154 aes_expand_key(key, key_exp); 155 156 /* Calculate the number of AES blocks to encrypt. */ 157 aes_blocks = ENV_SIZE / AES_KEY_LENGTH; 158 159 if (enc) 160 aes_cbc_encrypt_blocks(key_exp, data, data, aes_blocks); 161 else 162 aes_cbc_decrypt_blocks(key_exp, data, data, aes_blocks); 163 164 return 0; 165 } 166 #else 167 static inline int env_aes_cbc_crypt(env_t *env, const int enc) 168 { 169 return 0; 170 } 171 #endif 172 173 /* 174 * Check if CRC is valid and (if yes) import the environment. 175 * Note that "buf" may or may not be aligned. 176 */ 177 int env_import(const char *buf, int check) 178 { 179 env_t *ep = (env_t *)buf; 180 int ret; 181 182 if (check) { 183 uint32_t crc; 184 185 memcpy(&crc, &ep->crc, sizeof(crc)); 186 187 if (crc32(0, ep->data, ENV_SIZE) != crc) { 188 set_default_env("!bad CRC"); 189 return 0; 190 } 191 } 192 193 /* Decrypt the env if desired. */ 194 ret = env_aes_cbc_crypt(ep, 0); 195 if (ret) { 196 error("Failed to decrypt env!\n"); 197 set_default_env("!import failed"); 198 return ret; 199 } 200 201 if (himport_r(&env_htab, (char *)ep->data, ENV_SIZE, '\0', 0, 0, 202 0, NULL)) { 203 gd->flags |= GD_FLG_ENV_READY; 204 return 1; 205 } 206 207 error("Cannot import environment: errno = %d\n", errno); 208 209 set_default_env("!import failed"); 210 211 return 0; 212 } 213 214 #ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT 215 static unsigned char env_flags; 216 217 int env_import_redund(const char *buf1, const char *buf2) 218 { 219 int crc1_ok, crc2_ok; 220 env_t *ep, *tmp_env1, *tmp_env2; 221 222 tmp_env1 = (env_t *)buf1; 223 tmp_env2 = (env_t *)buf2; 224 225 crc1_ok = crc32(0, tmp_env1->data, ENV_SIZE) == 226 tmp_env1->crc; 227 crc2_ok = crc32(0, tmp_env2->data, ENV_SIZE) == 228 tmp_env2->crc; 229 230 if (!crc1_ok && !crc2_ok) { 231 set_default_env("!bad CRC"); 232 return 0; 233 } else if (crc1_ok && !crc2_ok) { 234 gd->env_valid = 1; 235 } else if (!crc1_ok && crc2_ok) { 236 gd->env_valid = 2; 237 } else { 238 /* both ok - check serial */ 239 if (tmp_env1->flags == 255 && tmp_env2->flags == 0) 240 gd->env_valid = 2; 241 else if (tmp_env2->flags == 255 && tmp_env1->flags == 0) 242 gd->env_valid = 1; 243 else if (tmp_env1->flags > tmp_env2->flags) 244 gd->env_valid = 1; 245 else if (tmp_env2->flags > tmp_env1->flags) 246 gd->env_valid = 2; 247 else /* flags are equal - almost impossible */ 248 gd->env_valid = 1; 249 } 250 251 if (gd->env_valid == 1) 252 ep = tmp_env1; 253 else 254 ep = tmp_env2; 255 256 env_flags = ep->flags; 257 return env_import((char *)ep, 0); 258 } 259 #endif /* CONFIG_SYS_REDUNDAND_ENVIRONMENT */ 260 261 /* Export the environment and generate CRC for it. */ 262 int env_export(env_t *env_out) 263 { 264 char *res; 265 ssize_t len; 266 int ret; 267 268 res = (char *)env_out->data; 269 len = hexport_r(&env_htab, '\0', 0, &res, ENV_SIZE, 0, NULL); 270 if (len < 0) { 271 error("Cannot export environment: errno = %d\n", errno); 272 return 1; 273 } 274 275 /* Encrypt the env if desired. */ 276 ret = env_aes_cbc_crypt(env_out, 1); 277 if (ret) 278 return ret; 279 280 env_out->crc = crc32(0, env_out->data, ENV_SIZE); 281 282 #ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT 283 env_out->flags = ++env_flags; /* increase the serial */ 284 #endif 285 286 return 0; 287 } 288 289 void env_relocate(void) 290 { 291 #if defined(CONFIG_NEEDS_MANUAL_RELOC) 292 env_reloc(); 293 env_htab.change_ok += gd->reloc_off; 294 #endif 295 if (gd->env_valid == 0) { 296 #if defined(CONFIG_ENV_IS_NOWHERE) || defined(CONFIG_SPL_BUILD) 297 /* Environment not changable */ 298 set_default_env(NULL); 299 #else 300 bootstage_error(BOOTSTAGE_ID_NET_CHECKSUM); 301 set_default_env("!bad CRC"); 302 #endif 303 } else { 304 env_relocate_spec(); 305 } 306 } 307 308 #if defined(CONFIG_AUTO_COMPLETE) && !defined(CONFIG_SPL_BUILD) 309 int env_complete(char *var, int maxv, char *cmdv[], int bufsz, char *buf) 310 { 311 ENTRY *match; 312 int found, idx; 313 314 idx = 0; 315 found = 0; 316 cmdv[0] = NULL; 317 318 while ((idx = hmatch_r(var, idx, &match, &env_htab))) { 319 int vallen = strlen(match->key) + 1; 320 321 if (found >= maxv - 2 || bufsz < vallen) 322 break; 323 324 cmdv[found++] = buf; 325 memcpy(buf, match->key, vallen); 326 buf += vallen; 327 bufsz -= vallen; 328 } 329 330 qsort(cmdv, found, sizeof(cmdv[0]), strcmp_compar); 331 332 if (idx) 333 cmdv[found++] = "..."; 334 335 cmdv[found] = NULL; 336 return found; 337 } 338 #endif 339