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 26 #include <sys/cdefs.h> 27 #include <efivar.h> 28 #include <sys/efiio.h> 29 #include <sys/param.h> 30 #include <errno.h> 31 #include <fcntl.h> 32 #include <stdio.h> 33 #include <stdlib.h> 34 #include <string.h> 35 36 #include "efichar.h" 37 38 static int efi_fd = -2; 39 40 #define Z { 0, 0, 0, 0, 0, { 0 } } 41 42 const efi_guid_t efi_guid_empty = Z; 43 44 static struct uuid_table guid_tbl [] = 45 { 46 { "00000000-0000-0000-0000-000000000000", "zero", Z }, 47 { "093e0fae-a6c4-4f50-9f1b-d41e2b89c19a", "sha512", Z }, 48 { "0abba7dc-e516-4167-bbf5-4d9d1c739416", "redhat", Z }, 49 { "0b6e5233-a65c-44c9-9407-d9ab83bfc8bd", "sha224", Z }, 50 { "126a762d-5758-4fca-8531-201a7f57f850", "lenovo_boot_menu", Z }, 51 { "3bd2a492-96c0-4079-b420-fcf98ef103ed", "x509_sha256", Z }, 52 { "3c5766e8-269c-4e34-aa14-ed776e85b3b6", "rsa2048", Z }, 53 { "3CC24E96-22C7-41D8-8863-8E39DCDCC2CF", "lenovo", Z }, 54 { "3f7e615b-0d45-4f80-88dc-26b234958560", "lenovo_diag", Z }, 55 { "446dbf63-2502-4cda-bcfa-2465d2b0fe9d", "x509_sha512", Z }, 56 { "4aafd29d-68df-49ee-8aa9-347d375665a7", "pkcs7_cert", Z }, 57 { "605dab50-e046-4300-abb6-3dd810dd8b23", "shim", Z }, 58 { "665d3f60-ad3e-4cad-8e26-db46eee9f1b5", "lenovo_rescue", Z }, 59 { "67f8444f-8743-48f1-a328-1eaab8736080", "rsa2048_sha1", Z }, 60 { "7076876e-80c2-4ee6-aad2-28b349a6865b", "x509_sha384", Z }, 61 { "721c8b66-426c-4e86-8e99-3457c46ab0b9", "lenovo_setup", Z }, 62 { "77fa9abd-0359-4d32-bd60-28f4e78f784b", "microsoft", Z }, 63 { "7FACC7B6-127F-4E9C-9C5D-080F98994345", "lenovo_2", Z }, 64 { "826ca512-cf10-4ac9-b187-be01496631bd", "sha1", Z }, 65 { "82988420-7467-4490-9059-feb448dd1963", "lenovo_me_config", Z }, 66 { "8be4df61-93ca-11d2-aa0d-00e098032b8c", "global", Z }, 67 { "a5c059a1-94e4-4aa7-87b5-ab155c2bf072", "x509_cert", Z }, 68 { "a7717414-c616-4977-9420-844712a735bf", "rsa2048_sha256_cert", Z }, 69 { "a7d8d9a6-6ab0-4aeb-ad9d-163e59a7a380", "lenovo_diag_splash", Z }, 70 { "ade9e48f-9cb8-98e6-31af-b4e6009e2fe3", "redhat_2", Z }, 71 { "bc7838d2-0f82-4d60-8316-c068ee79d25b", "lenovo_msg", Z }, 72 { "c1c41626-504c-4092-aca9-41f936934328", "sha256", Z }, 73 { "c57ad6b7-0515-40a8-9d21-551652854e37", "shell", Z }, 74 { "d719b2cb-3d3a-4596-a3bc-dad00e67656f", "security", Z }, 75 { "e2b36190-879b-4a3d-ad8d-f2e7bba32784", "rsa2048_sha256", Z }, 76 { "ff3e5307-9fd0-48c9-85f1-8ad56c701e01", "sha384", Z }, 77 { "f46ee6f4-4785-43a3-923d-7f786c3c8479", "lenovo_startup_interrupt", Z }, 78 { "ffffffff-ffff-ffff-ffff-ffffffffffff", "zzignore-this-guid", Z }, 79 }; 80 #undef Z 81 82 static void 83 efi_guid_tbl_compile(void) 84 { 85 size_t i; 86 uint32_t status; 87 static int done = 0; 88 89 if (done) 90 return; 91 for (i = 0; i < nitems(guid_tbl); i++) { 92 uuid_from_string(guid_tbl[i].uuid_str, &guid_tbl[i].guid, 93 &status); 94 /* all f's is a bad version, so ignore that error */ 95 if (status != uuid_s_ok && status != uuid_s_bad_version) 96 fprintf(stderr, "Can't convert %s to a uuid for %s: %d\n", 97 guid_tbl[i].uuid_str, guid_tbl[i].name, (int)status); 98 } 99 done = 1; 100 } 101 102 int 103 efi_known_guid(struct uuid_table **tbl) 104 { 105 106 *tbl = guid_tbl; 107 return (nitems(guid_tbl)); 108 } 109 110 static int 111 efi_open_dev(void) 112 { 113 114 if (efi_fd == -2) 115 efi_fd = open("/dev/efi", O_RDWR); 116 if (efi_fd < 0) 117 efi_fd = -1; 118 else 119 efi_guid_tbl_compile(); 120 return (efi_fd); 121 } 122 123 static void 124 efi_var_reset(struct efi_var_ioc *var) 125 { 126 var->name = NULL; 127 var->namesize = 0; 128 memset(&var->vendor, 0, sizeof(var->vendor)); 129 var->attrib = 0; 130 var->data = NULL; 131 var->datasize = 0; 132 } 133 134 static int 135 rv_to_linux_rv(int rv) 136 { 137 if (rv == 0) 138 rv = 1; 139 else 140 rv = -errno; 141 return (rv); 142 } 143 144 int 145 efi_append_variable(efi_guid_t guid, const char *name, 146 uint8_t *data, size_t data_size, uint32_t attributes) 147 { 148 149 return efi_set_variable(guid, name, data, data_size, 150 attributes | EFI_VARIABLE_APPEND_WRITE); 151 } 152 153 int 154 efi_del_variable(efi_guid_t guid, const char *name) 155 { 156 157 /* data_size of 0 deletes the variable */ 158 return efi_set_variable(guid, name, NULL, 0, 0); 159 } 160 161 int 162 efi_get_variable(efi_guid_t guid, const char *name, 163 uint8_t **data, size_t *data_size, uint32_t *attributes) 164 { 165 struct efi_var_ioc var; 166 int rv; 167 static uint8_t buf[1024*32]; 168 169 if (efi_open_dev() == -1) 170 return -1; 171 172 efi_var_reset(&var); 173 rv = utf8_to_ucs2(name, &var.name, &var.namesize); 174 if (rv != 0) 175 goto errout; 176 var.vendor = guid; 177 var.data = buf; 178 var.datasize = sizeof(buf); 179 rv = ioctl(efi_fd, EFIIOC_VAR_GET, &var); 180 if (data_size != NULL) 181 *data_size = var.datasize; 182 if (data != NULL) 183 *data = buf; 184 if (attributes != NULL) 185 *attributes = var.attrib; 186 errout: 187 free(var.name); 188 189 return rv_to_linux_rv(rv); 190 } 191 192 int 193 efi_get_variable_attributes(efi_guid_t guid, const char *name, 194 uint32_t *attributes) 195 { 196 /* Make sure this construct works -- I think it will fail */ 197 198 return efi_get_variable(guid, name, NULL, NULL, attributes); 199 } 200 201 int 202 efi_get_variable_size(efi_guid_t guid, const char *name, 203 size_t *size) 204 { 205 206 /* XXX check to make sure this matches the linux value */ 207 208 *size = 0; 209 return efi_get_variable(guid, name, NULL, size, NULL); 210 } 211 212 int 213 efi_get_next_variable_name(efi_guid_t **guid, char **name) 214 { 215 struct efi_var_ioc var; 216 int rv; 217 static efi_char *buf; 218 static size_t buflen = 256 * sizeof(efi_char); 219 static efi_guid_t retguid; 220 size_t size; 221 222 if (efi_open_dev() == -1) 223 return -1; 224 225 /* 226 * Always allocate enough for an extra NUL on the end, but don't tell 227 * the IOCTL about it so we can NUL terminate the name before converting 228 * it to UTF8. 229 */ 230 if (buf == NULL) 231 buf = malloc(buflen + sizeof(efi_char)); 232 233 again: 234 efi_var_reset(&var); 235 var.name = buf; 236 var.namesize = buflen; 237 if (*name == NULL) { 238 *buf = 0; 239 /* GUID zeroed in var_reset */ 240 } else { 241 rv = utf8_to_ucs2(*name, &var.name, &size); 242 if (rv != 0) 243 goto errout; 244 var.vendor = **guid; 245 } 246 rv = ioctl(efi_fd, EFIIOC_VAR_NEXT, &var); 247 if (rv == 0 && var.name == NULL) { 248 /* 249 * Variable name not long enough, so allocate more space for the 250 * name and try again. As above, mind the NUL we add. 251 */ 252 void *new = realloc(buf, var.namesize + sizeof(efi_char)); 253 if (new == NULL) { 254 rv = -1; 255 errno = ENOMEM; 256 goto done; 257 } 258 buflen = var.namesize; 259 buf = new; 260 goto again; 261 } 262 263 if (rv == 0) { 264 free(*name); /* Free last name, to avoid leaking */ 265 *name = NULL; /* Force ucs2_to_utf8 to malloc new space */ 266 var.name[var.namesize / sizeof(efi_char)] = 0; /* EFI doesn't NUL terminate */ 267 rv = ucs2_to_utf8(var.name, name); 268 if (rv != 0) 269 goto errout; 270 retguid = var.vendor; 271 *guid = &retguid; 272 } 273 errout: 274 275 /* XXX The linux interface expects name to be a static buffer -- fix or leak memory? */ 276 /* XXX for the moment, we free just before we'd leak, but still leak last one */ 277 done: 278 if (rv != 0 && errno == ENOENT) { 279 errno = 0; 280 free(*name); /* Free last name, to avoid leaking */ 281 return 0; 282 } 283 284 return (rv_to_linux_rv(rv)); 285 } 286 287 int 288 efi_guid_cmp(const efi_guid_t *guid1, const efi_guid_t *guid2) 289 { 290 uint32_t status; 291 292 return uuid_compare(guid1, guid2, &status); 293 } 294 295 int 296 efi_guid_is_zero(const efi_guid_t *guid) 297 { 298 uint32_t status; 299 300 return uuid_is_nil(guid, &status); 301 } 302 303 int 304 efi_guid_to_name(efi_guid_t *guid, char **name) 305 { 306 size_t i; 307 uint32_t status; 308 309 efi_guid_tbl_compile(); 310 for (i = 0; i < nitems(guid_tbl); i++) { 311 if (uuid_equal(guid, &guid_tbl[i].guid, &status)) { 312 *name = strdup(guid_tbl[i].name); 313 return (0); 314 } 315 } 316 return (efi_guid_to_str(guid, name)); 317 } 318 319 int 320 efi_guid_to_symbol(efi_guid_t *guid __unused, char **symbol __unused) 321 { 322 323 /* 324 * Unsure what this is used for, efibootmgr doesn't use it. 325 * Leave unimplemented for now. 326 */ 327 return -1; 328 } 329 330 int 331 efi_guid_to_str(const efi_guid_t *guid, char **sp) 332 { 333 uint32_t status; 334 335 /* knows efi_guid_t is a typedef of uuid_t */ 336 uuid_to_string(guid, sp, &status); 337 338 return (status == uuid_s_ok ? 0 : -1); 339 } 340 341 int 342 efi_name_to_guid(const char *name, efi_guid_t *guid) 343 { 344 size_t i; 345 346 efi_guid_tbl_compile(); 347 for (i = 0; i < nitems(guid_tbl); i++) { 348 if (strcmp(name, guid_tbl[i].name) == 0) { 349 *guid = guid_tbl[i].guid; 350 return (0); 351 } 352 } 353 return (efi_str_to_guid(name, guid)); 354 } 355 356 int 357 efi_set_variable(efi_guid_t guid, const char *name, 358 uint8_t *data, size_t data_size, uint32_t attributes) 359 { 360 struct efi_var_ioc var; 361 int rv; 362 363 if (efi_open_dev() == -1) 364 return -1; 365 366 efi_var_reset(&var); 367 rv = utf8_to_ucs2(name, &var.name, &var.namesize); 368 if (rv != 0) 369 goto errout; 370 var.vendor = guid; 371 var.data = data; 372 var.datasize = data_size; 373 var.attrib = attributes; 374 rv = ioctl(efi_fd, EFIIOC_VAR_SET, &var); 375 errout: 376 free(var.name); 377 378 return rv; 379 } 380 381 int 382 efi_str_to_guid(const char *s, efi_guid_t *guid) 383 { 384 uint32_t status; 385 386 /* knows efi_guid_t is a typedef of uuid_t */ 387 uuid_from_string(s, guid, &status); 388 389 return (status == uuid_s_ok ? 0 : -1); 390 } 391 392 int 393 efi_variables_supported(void) 394 { 395 396 return efi_open_dev() != -1; 397 } 398