1 /*- 2 * Copyright (c) 2016 Netflix, Inc. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer 10 * in this position and unchanged. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD: head/lib/libefivar/efivar.c 307189 2016-10-13 06:56:23Z imp $"); 29 30 #include <efivar.h> 31 #include <sys/efiio.h> 32 #include <sys/param.h> 33 #include <errno.h> 34 #include <fcntl.h> 35 #include <stdio.h> 36 #include <stdlib.h> 37 #include <string.h> 38 39 #include "libefivar_int.h" 40 41 static int efi_fd = -2; 42 43 #define Z { 0, 0, 0, 0, 0, { 0 } } 44 45 const efi_guid_t efi_guid_empty = Z; 46 47 static struct uuid_table 48 { 49 const char *uuid_str; 50 const char *name; 51 efi_guid_t guid; 52 } guid_tbl [] = 53 { 54 { "00000000-0000-0000-0000-000000000000", "zero", Z }, 55 { "093e0fae-a6c4-4f50-9f1b-d41e2b89c19a", "sha512", Z }, 56 { "0abba7dc-e516-4167-bbf5-4d9d1c739416", "redhat", Z }, 57 { "0b6e5233-a65c-44c9-9407-d9ab83bfc8bd", "sha224", Z }, 58 { "126a762d-5758-4fca-8531-201a7f57f850", "lenovo_boot_menu", Z }, 59 { "3bd2a492-96c0-4079-b420-fcf98ef103ed", "x509_sha256", Z }, 60 { "3c5766e8-269c-4e34-aa14-ed776e85b3b6", "rsa2048", Z }, 61 { "3CC24E96-22C7-41D8-8863-8E39DCDCC2CF", "lenovo", Z }, 62 { "3f7e615b-0d45-4f80-88dc-26b234958560", "lenovo_diag", Z }, 63 { "446dbf63-2502-4cda-bcfa-2465d2b0fe9d", "x509_sha512", Z }, 64 { "4aafd29d-68df-49ee-8aa9-347d375665a7", "pkcs7_cert", Z }, 65 { "605dab50-e046-4300-abb6-3dd810dd8b23", "shim", Z }, 66 { "665d3f60-ad3e-4cad-8e26-db46eee9f1b5", "lenovo_rescue", Z }, 67 { "67f8444f-8743-48f1-a328-1eaab8736080", "rsa2048_sha1", Z }, 68 { "7076876e-80c2-4ee6-aad2-28b349a6865b", "x509_sha384", Z }, 69 { "721c8b66-426c-4e86-8e99-3457c46ab0b9", "lenovo_setup", Z }, 70 { "77fa9abd-0359-4d32-bd60-28f4e78f784b", "microsoft", Z }, 71 { "7FACC7B6-127F-4E9C-9C5D-080F98994345", "lenovo_2", Z }, 72 { "826ca512-cf10-4ac9-b187-be01496631bd", "sha1", Z }, 73 { "82988420-7467-4490-9059-feb448dd1963", "lenovo_me_config", Z }, 74 { "8be4df61-93ca-11d2-aa0d-00e098032b8c", "global", Z }, 75 { "a5c059a1-94e4-4aa7-87b5-ab155c2bf072", "x509_cert", Z }, 76 { "a7717414-c616-4977-9420-844712a735bf", "rsa2048_sha256_cert", Z }, 77 { "a7d8d9a6-6ab0-4aeb-ad9d-163e59a7a380", "lenovo_diag_splash", Z }, 78 { "ade9e48f-9cb8-98e6-31af-b4e6009e2fe3", "redhat_2", Z }, 79 { "bc7838d2-0f82-4d60-8316-c068ee79d25b", "lenovo_msg", Z }, 80 { "c1c41626-504c-4092-aca9-41f936934328", "sha256", Z }, 81 { "c57ad6b7-0515-40a8-9d21-551652854e37", "shell", Z }, 82 { "d719b2cb-3d3a-4596-a3bc-dad00e67656f", "security", Z }, 83 { "e2b36190-879b-4a3d-ad8d-f2e7bba32784", "rsa2048_sha256", Z }, 84 { "ff3e5307-9fd0-48c9-85f1-8ad56c701e01", "sha384", Z }, 85 { "f46ee6f4-4785-43a3-923d-7f786c3c8479", "lenovo_startup_interrupt", Z }, 86 { "ffffffff-ffff-ffff-ffff-ffffffffffff", "zzignore-this-guid", Z }, 87 }; 88 #undef Z 89 90 static void 91 efi_guid_tbl_compile(void) 92 { 93 size_t i; 94 uint32_t status; 95 96 for (i = 0; i < nitems(guid_tbl); i++) { 97 uuid_from_string(guid_tbl[i].uuid_str, &guid_tbl[i].guid, 98 &status); 99 /* all f's is a bad version, so ignore that error */ 100 if (status != uuid_s_ok && status != uuid_s_bad_version) 101 fprintf(stderr, "Can't convert %s to a uuid for %s: %d\n", 102 guid_tbl[i].uuid_str, guid_tbl[i].name, (int)status); 103 } 104 } 105 106 static int 107 efi_open_dev(void) 108 { 109 110 if (efi_fd == -2) 111 efi_fd = open("/dev/efi", O_RDWR); 112 if (efi_fd < 0) 113 efi_fd = -1; 114 else 115 efi_guid_tbl_compile(); 116 return (efi_fd); 117 } 118 119 static void 120 efi_var_reset(struct efi_var_ioc *var) 121 { 122 var->name = NULL; 123 var->namesize = 0; 124 memset(&var->vendor, 0, sizeof(var->vendor)); 125 var->attrib = 0; 126 var->data = NULL; 127 var->datasize = 0; 128 } 129 130 static int 131 rv_to_linux_rv(int rv) 132 { 133 if (rv == 0) 134 rv = 1; 135 else if (errno == ENOENT) { 136 rv = 0; 137 errno = 0; 138 } else 139 rv = -errno; 140 return (rv); 141 } 142 143 int 144 efi_append_variable(efi_guid_t guid, const char *name, 145 uint8_t *data, size_t data_size, uint32_t attributes) 146 { 147 148 return efi_set_variable(guid, name, data, data_size, 149 attributes | EFI_VARIABLE_APPEND_WRITE, 0); 150 } 151 152 int 153 efi_del_variable(efi_guid_t guid, const char *name) 154 { 155 156 /* data_size of 0 deletes the variable */ 157 return efi_set_variable(guid, name, NULL, 0, 0, 0); 158 } 159 160 int 161 efi_get_variable(efi_guid_t guid, const char *name, 162 uint8_t **data, size_t *data_size, uint32_t *attributes) 163 { 164 struct efi_var_ioc var; 165 int rv; 166 static uint8_t buf[1024*32]; 167 168 if (efi_open_dev() == -1) 169 return -1; 170 171 efi_var_reset(&var); 172 rv = libefi_utf8_to_ucs2(name, &var.name, &var.namesize); 173 if (rv != 0) 174 goto errout; 175 var.vendor = guid; 176 var.data = buf; 177 var.datasize = sizeof(buf); 178 rv = ioctl(efi_fd, EFIIOC_VAR_GET, &var); 179 if (data_size != NULL) 180 *data_size = var.datasize; 181 if (data != NULL) 182 *data = buf; 183 if (attributes != NULL) 184 *attributes = var.attrib; 185 errout: 186 free(var.name); 187 188 return rv_to_linux_rv(rv); 189 } 190 191 int 192 efi_get_variable_attributes(efi_guid_t guid, const char *name, 193 uint32_t *attributes) 194 { 195 /* Make sure this construct works -- I think it will fail */ 196 197 return efi_get_variable(guid, name, NULL, NULL, attributes); 198 } 199 200 int 201 efi_get_variable_size(efi_guid_t guid, const char *name, 202 size_t *size) 203 { 204 205 /* XXX check to make sure this matches the linux value */ 206 207 *size = 0; 208 return efi_get_variable(guid, name, NULL, size, NULL); 209 } 210 211 int 212 efi_get_next_variable_name(efi_guid_t **guid, char **name) 213 { 214 struct efi_var_ioc var; 215 int rv; 216 static efi_char *buf; 217 static size_t buflen = 256 * sizeof(efi_char); 218 static efi_guid_t retguid; 219 size_t size; 220 221 if (efi_open_dev() == -1) 222 return -1; 223 224 225 if (buf == NULL) 226 buf = malloc(buflen); 227 228 again: 229 efi_var_reset(&var); 230 var.name = buf; 231 var.namesize = buflen; 232 if (*name == NULL) { 233 *buf = 0; 234 /* GUID zeroed in var_reset */ 235 } else { 236 rv = libefi_utf8_to_ucs2(*name, &var.name, &size); 237 if (rv != 0) 238 goto errout; 239 var.vendor = **guid; 240 } 241 rv = ioctl(efi_fd, EFIIOC_VAR_NEXT, &var); 242 if (rv == 0 && var.name == NULL) { 243 /* 244 * oops, too little space. Try again. 245 */ 246 void *new = realloc(buf, buflen); 247 buflen = var.namesize; 248 if (new == NULL) { 249 rv = -1; 250 errno = ENOMEM; 251 goto done; 252 } 253 buf = new; 254 goto again; 255 } 256 257 if (rv == 0) { 258 *name = NULL; /* XXX */ 259 var.name[var.namesize / sizeof(efi_char)] = 0; /* EFI doesn't NUL terminate */ 260 rv = libefi_ucs2_to_utf8(var.name, name); 261 if (rv != 0) 262 goto errout; 263 retguid = var.vendor; 264 *guid = &retguid; 265 } 266 errout: 267 268 /* XXX The linux interface expects name to be a static buffer -- fix or leak memory? */ 269 done: 270 return (rv_to_linux_rv(rv)); 271 } 272 273 int 274 efi_guid_cmp(const efi_guid_t *guid1, const efi_guid_t *guid2) 275 { 276 uint32_t status; 277 278 return uuid_compare(guid1, guid2, &status); 279 } 280 281 int 282 efi_guid_is_zero(const efi_guid_t *guid) 283 { 284 uint32_t status; 285 286 return uuid_is_nil(guid, &status); 287 } 288 289 int 290 efi_guid_to_name(efi_guid_t *guid, char **name) 291 { 292 size_t i; 293 uint32_t status; 294 295 for (i = 0; i < nitems(guid_tbl); i++) { 296 if (uuid_equal(guid, &guid_tbl[i].guid, &status)) { 297 *name = strdup(guid_tbl[i].name); 298 return (0); 299 } 300 } 301 return (efi_guid_to_str(guid, name)); 302 } 303 304 int 305 efi_guid_to_symbol(efi_guid_t *guid __unused, char **symbol __unused) 306 { 307 308 /* 309 * Unsure what this is used for, efibootmgr doesn't use it. 310 * Leave unimplemented for now. 311 */ 312 return -1; 313 } 314 315 int 316 efi_guid_to_str(const efi_guid_t *guid, char **sp) 317 { 318 uint32_t status; 319 320 /* knows efi_guid_t is a typedef of uuid_t */ 321 uuid_to_string(guid, sp, &status); 322 323 return (status == uuid_s_ok ? 0 : -1); 324 } 325 326 int 327 efi_name_to_guid(const char *name, efi_guid_t *guid) 328 { 329 size_t i; 330 331 for (i = 0; i < nitems(guid_tbl); i++) { 332 if (strcmp(name, guid_tbl[i].name) == 0) { 333 *guid = guid_tbl[i].guid; 334 return (0); 335 } 336 } 337 return (efi_str_to_guid(name, guid)); 338 } 339 340 int 341 efi_set_variable(efi_guid_t guid, const char *name, 342 uint8_t *data, size_t data_size, uint32_t attributes, mode_t mode __unused) 343 { 344 struct efi_var_ioc var; 345 int rv; 346 347 if (efi_open_dev() == -1) 348 return -1; 349 350 efi_var_reset(&var); 351 rv = libefi_utf8_to_ucs2(name, &var.name, &var.namesize); 352 if (rv != 0) 353 goto errout; 354 var.vendor = guid; 355 var.data = data; 356 var.datasize = data_size; 357 var.attrib = attributes; 358 rv = ioctl(efi_fd, EFIIOC_VAR_SET, &var); 359 errout: 360 free(var.name); 361 362 return rv; 363 } 364 365 int 366 efi_str_to_guid(const char *s, efi_guid_t *guid) 367 { 368 uint32_t status; 369 370 /* knows efi_guid_t is a typedef of uuid_t */ 371 uuid_from_string(s, guid, &status); 372 373 return (status == uuid_s_ok ? 0 : -1); 374 } 375 376 int 377 efi_variables_supported(void) 378 { 379 380 return efi_open_dev() != -1; 381 } 382