1 /*- 2 * Copyright (c) 2016 Netflix, Inc. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23 * SUCH DAMAGE. 24 * 25 * $FreeBSD: head/lib/libefivar/efivar.c 343755 2019-02-04 21:28:25Z imp $ 26 */ 27 28 #include <efivar.h> 29 #include <sys/efiio.h> 30 #include <sys/param.h> 31 #include <errno.h> 32 #include <fcntl.h> 33 #include <stdio.h> 34 #include <stdlib.h> 35 #include <string.h> 36 37 #include "libefivar_int.h" 38 39 static int efi_fd = -2; 40 41 #define Z { 0, 0, 0, 0, 0, { 0 } } 42 43 const efi_guid_t efi_guid_empty = Z; 44 45 static struct uuid_table guid_tbl [] = 46 { 47 { "00000000-0000-0000-0000-000000000000", "zero", Z }, 48 { "093e0fae-a6c4-4f50-9f1b-d41e2b89c19a", "sha512", Z }, 49 { "0abba7dc-e516-4167-bbf5-4d9d1c739416", "redhat", Z }, 50 { "0b6e5233-a65c-44c9-9407-d9ab83bfc8bd", "sha224", Z }, 51 { "126a762d-5758-4fca-8531-201a7f57f850", "lenovo_boot_menu", Z }, 52 { "3bd2a492-96c0-4079-b420-fcf98ef103ed", "x509_sha256", Z }, 53 { "3c5766e8-269c-4e34-aa14-ed776e85b3b6", "rsa2048", Z }, 54 { "3CC24E96-22C7-41D8-8863-8E39DCDCC2CF", "lenovo", Z }, 55 { "3f7e615b-0d45-4f80-88dc-26b234958560", "lenovo_diag", Z }, 56 { "446dbf63-2502-4cda-bcfa-2465d2b0fe9d", "x509_sha512", Z }, 57 { "4aafd29d-68df-49ee-8aa9-347d375665a7", "pkcs7_cert", Z }, 58 { "605dab50-e046-4300-abb6-3dd810dd8b23", "shim", Z }, 59 { "665d3f60-ad3e-4cad-8e26-db46eee9f1b5", "lenovo_rescue", Z }, 60 { "67f8444f-8743-48f1-a328-1eaab8736080", "rsa2048_sha1", Z }, 61 { "7076876e-80c2-4ee6-aad2-28b349a6865b", "x509_sha384", Z }, 62 { "721c8b66-426c-4e86-8e99-3457c46ab0b9", "lenovo_setup", Z }, 63 { "77fa9abd-0359-4d32-bd60-28f4e78f784b", "microsoft", Z }, 64 { "7FACC7B6-127F-4E9C-9C5D-080F98994345", "lenovo_2", Z }, 65 { "826ca512-cf10-4ac9-b187-be01496631bd", "sha1", Z }, 66 { "82988420-7467-4490-9059-feb448dd1963", "lenovo_me_config", Z }, 67 { "8be4df61-93ca-11d2-aa0d-00e098032b8c", "global", Z }, 68 { "a5c059a1-94e4-4aa7-87b5-ab155c2bf072", "x509_cert", Z }, 69 { "a7717414-c616-4977-9420-844712a735bf", "rsa2048_sha256_cert", Z }, 70 { "a7d8d9a6-6ab0-4aeb-ad9d-163e59a7a380", "lenovo_diag_splash", Z }, 71 { "ade9e48f-9cb8-98e6-31af-b4e6009e2fe3", "redhat_2", Z }, 72 { "bc7838d2-0f82-4d60-8316-c068ee79d25b", "lenovo_msg", Z }, 73 { "c1c41626-504c-4092-aca9-41f936934328", "sha256", Z }, 74 { "c57ad6b7-0515-40a8-9d21-551652854e37", "shell", Z }, 75 { "d719b2cb-3d3a-4596-a3bc-dad00e67656f", "security", Z }, 76 { "e2b36190-879b-4a3d-ad8d-f2e7bba32784", "rsa2048_sha256", Z }, 77 { "ff3e5307-9fd0-48c9-85f1-8ad56c701e01", "sha384", Z }, 78 { "f46ee6f4-4785-43a3-923d-7f786c3c8479", "lenovo_startup_interrupt", Z }, 79 { "ffffffff-ffff-ffff-ffff-ffffffffffff", "zzignore-this-guid", Z }, 80 }; 81 #undef Z 82 83 static void 84 efi_guid_tbl_compile(void) 85 { 86 size_t i; 87 uint32_t status; 88 static int done = 0; 89 90 if (done) 91 return; 92 for (i = 0; i < nitems(guid_tbl); i++) { 93 uuid_from_string(guid_tbl[i].uuid_str, &guid_tbl[i].guid, 94 &status); 95 /* all f's is a bad version, so ignore that error */ 96 if (status != uuid_s_ok && status != uuid_s_bad_version) 97 fprintf(stderr, "Can't convert %s to a uuid for %s: %d\n", 98 guid_tbl[i].uuid_str, guid_tbl[i].name, (int)status); 99 } 100 done = 1; 101 } 102 103 int 104 efi_known_guid(struct uuid_table **tbl) 105 { 106 107 *tbl = guid_tbl; 108 return (nitems(guid_tbl)); 109 } 110 111 static int 112 efi_open_dev(void) 113 { 114 115 if (efi_fd == -2) 116 efi_fd = open("/dev/efi", O_RDWR); 117 if (efi_fd < 0) 118 efi_fd = -1; 119 else 120 efi_guid_tbl_compile(); 121 return (efi_fd); 122 } 123 124 static void 125 efi_var_reset(struct efi_var_ioc *var) 126 { 127 var->name = NULL; 128 var->namesize = 0; 129 memset(&var->vendor, 0, sizeof(var->vendor)); 130 var->attrib = 0; 131 var->data = NULL; 132 var->datasize = 0; 133 } 134 135 static int 136 rv_to_linux_rv(int rv) 137 { 138 if (rv == 0) 139 rv = 1; 140 else 141 rv = -errno; 142 return (rv); 143 } 144 145 int 146 efi_append_variable(efi_guid_t guid, const char *name, 147 uint8_t *data, size_t data_size, uint32_t attributes) 148 { 149 150 return efi_set_variable(guid, name, data, data_size, 151 attributes | EFI_VARIABLE_APPEND_WRITE); 152 } 153 154 int 155 efi_del_variable(efi_guid_t guid, const char *name) 156 { 157 158 /* data_size of 0 deletes the variable */ 159 return efi_set_variable(guid, name, NULL, 0, 0); 160 } 161 162 int 163 efi_get_variable(efi_guid_t guid, const char *name, 164 uint8_t **data, size_t *data_size, uint32_t *attributes) 165 { 166 struct efi_var_ioc var; 167 int rv; 168 static uint8_t buf[1024*32]; 169 170 if (efi_open_dev() == -1) 171 return -1; 172 173 efi_var_reset(&var); 174 rv = utf8_to_ucs2(name, &var.name, &var.namesize); 175 if (rv != 0) 176 goto errout; 177 var.vendor = guid; 178 var.data = buf; 179 var.datasize = sizeof(buf); 180 rv = ioctl(efi_fd, EFIIOC_VAR_GET, &var); 181 if (data_size != NULL) 182 *data_size = var.datasize; 183 if (data != NULL) 184 *data = buf; 185 if (attributes != NULL) 186 *attributes = var.attrib; 187 errout: 188 free(var.name); 189 190 return rv_to_linux_rv(rv); 191 } 192 193 int 194 efi_get_variable_attributes(efi_guid_t guid, const char *name, 195 uint32_t *attributes) 196 { 197 /* Make sure this construct works -- I think it will fail */ 198 199 return efi_get_variable(guid, name, NULL, NULL, attributes); 200 } 201 202 int 203 efi_get_variable_size(efi_guid_t guid, const char *name, 204 size_t *size) 205 { 206 207 /* XXX check to make sure this matches the linux value */ 208 209 *size = 0; 210 return efi_get_variable(guid, name, NULL, size, NULL); 211 } 212 213 int 214 efi_get_next_variable_name(efi_guid_t **guid, char **name) 215 { 216 struct efi_var_ioc var; 217 int rv; 218 static efi_char *buf; 219 static size_t buflen = 256 * sizeof(efi_char); 220 static efi_guid_t retguid; 221 size_t size; 222 223 if (efi_open_dev() == -1) 224 return -1; 225 226 /* 227 * Always allocate enough for an extra NUL on the end, but don't tell 228 * the IOCTL about it so we can NUL terminate the name before converting 229 * it to UTF8. 230 */ 231 if (buf == NULL) 232 buf = malloc(buflen + sizeof(efi_char)); 233 234 again: 235 efi_var_reset(&var); 236 var.name = buf; 237 var.namesize = buflen; 238 if (*name == NULL) { 239 *buf = 0; 240 /* GUID zeroed in var_reset */ 241 } else { 242 rv = utf8_to_ucs2(*name, &var.name, &size); 243 if (rv != 0) 244 goto errout; 245 var.vendor = **guid; 246 } 247 rv = ioctl(efi_fd, EFIIOC_VAR_NEXT, &var); 248 if (rv == 0 && var.name == NULL) { 249 /* 250 * Variable name not long enough, so allocate more space for the 251 * name and try again. As above, mind the NUL we add. 252 */ 253 void *new = realloc(buf, var.namesize + sizeof(efi_char)); 254 if (new == NULL) { 255 rv = -1; 256 errno = ENOMEM; 257 goto done; 258 } 259 buflen = var.namesize; 260 buf = new; 261 goto again; 262 } 263 264 if (rv == 0) { 265 free(*name); /* Free last name, to avoid leaking */ 266 *name = NULL; /* Force ucs2_to_utf8 to malloc new space */ 267 var.name[var.namesize / sizeof(efi_char)] = 0; /* EFI doesn't NUL terminate */ 268 rv = ucs2_to_utf8(var.name, name); 269 if (rv != 0) 270 goto errout; 271 retguid = var.vendor; 272 *guid = &retguid; 273 } 274 errout: 275 276 /* XXX The linux interface expects name to be a static buffer -- fix or leak memory? */ 277 /* XXX for the moment, we free just before we'd leak, but still leak last one */ 278 done: 279 if (rv != 0 && errno == ENOENT) { 280 errno = 0; 281 free(*name); /* Free last name, to avoid leaking */ 282 return 0; 283 } 284 285 return (rv_to_linux_rv(rv)); 286 } 287 288 int 289 efi_guid_cmp(const efi_guid_t *guid1, const efi_guid_t *guid2) 290 { 291 uint32_t status; 292 293 return uuid_compare(guid1, guid2, &status); 294 } 295 296 int 297 efi_guid_is_zero(const efi_guid_t *guid) 298 { 299 uint32_t status; 300 301 return uuid_is_nil(guid, &status); 302 } 303 304 int 305 efi_guid_to_name(efi_guid_t *guid, char **name) 306 { 307 size_t i; 308 uint32_t status; 309 310 efi_guid_tbl_compile(); 311 for (i = 0; i < nitems(guid_tbl); i++) { 312 if (uuid_equal(guid, &guid_tbl[i].guid, &status)) { 313 *name = strdup(guid_tbl[i].name); 314 return (0); 315 } 316 } 317 return (efi_guid_to_str(guid, name)); 318 } 319 320 int 321 efi_guid_to_symbol(efi_guid_t *guid __unused, char **symbol __unused) 322 { 323 324 /* 325 * Unsure what this is used for, efibootmgr doesn't use it. 326 * Leave unimplemented for now. 327 */ 328 return -1; 329 } 330 331 int 332 efi_guid_to_str(const efi_guid_t *guid, char **sp) 333 { 334 uint32_t status; 335 336 /* knows efi_guid_t is a typedef of uuid_t */ 337 uuid_to_string(guid, sp, &status); 338 339 return (status == uuid_s_ok ? 0 : -1); 340 } 341 342 int 343 efi_name_to_guid(const char *name, efi_guid_t *guid) 344 { 345 size_t i; 346 347 efi_guid_tbl_compile(); 348 for (i = 0; i < nitems(guid_tbl); i++) { 349 if (strcmp(name, guid_tbl[i].name) == 0) { 350 *guid = guid_tbl[i].guid; 351 return (0); 352 } 353 } 354 return (efi_str_to_guid(name, guid)); 355 } 356 357 int 358 efi_set_variable(efi_guid_t guid, const char *name, 359 uint8_t *data, size_t data_size, uint32_t attributes) 360 { 361 struct efi_var_ioc var; 362 int rv; 363 364 if (efi_open_dev() == -1) 365 return -1; 366 367 efi_var_reset(&var); 368 rv = utf8_to_ucs2(name, &var.name, &var.namesize); 369 if (rv != 0) 370 goto errout; 371 var.vendor = guid; 372 var.data = data; 373 var.datasize = data_size; 374 var.attrib = attributes; 375 rv = ioctl(efi_fd, EFIIOC_VAR_SET, &var); 376 errout: 377 free(var.name); 378 379 return rv; 380 } 381 382 int 383 efi_str_to_guid(const char *s, efi_guid_t *guid) 384 { 385 uint32_t status; 386 387 /* knows efi_guid_t is a typedef of uuid_t */ 388 uuid_from_string(s, guid, &status); 389 390 return (status == uuid_s_ok ? 0 : -1); 391 } 392 393 int 394 efi_variables_supported(void) 395 { 396 397 return efi_open_dev() != -1; 398 } 399