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 __FBSDID("$FreeBSD$");
28
29 #include <efivar.h>
30 #include <sys/efiio.h>
31 #include <sys/param.h>
32 #include <errno.h>
33 #include <fcntl.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <string.h>
37
38 #include "efichar.h"
39
40 static int efi_fd = -2;
41
42 #define Z { 0, 0, 0, 0, 0, { 0 } }
43
44 const efi_guid_t efi_guid_empty = Z;
45
46 static struct uuid_table guid_tbl [] =
47 {
48 { "00000000-0000-0000-0000-000000000000", "zero", Z },
49 { "093e0fae-a6c4-4f50-9f1b-d41e2b89c19a", "sha512", Z },
50 { "0abba7dc-e516-4167-bbf5-4d9d1c739416", "redhat", Z },
51 { "0b6e5233-a65c-44c9-9407-d9ab83bfc8bd", "sha224", Z },
52 { "126a762d-5758-4fca-8531-201a7f57f850", "lenovo_boot_menu", Z },
53 { "3bd2a492-96c0-4079-b420-fcf98ef103ed", "x509_sha256", Z },
54 { "3c5766e8-269c-4e34-aa14-ed776e85b3b6", "rsa2048", Z },
55 { "3CC24E96-22C7-41D8-8863-8E39DCDCC2CF", "lenovo", Z },
56 { "3f7e615b-0d45-4f80-88dc-26b234958560", "lenovo_diag", Z },
57 { "446dbf63-2502-4cda-bcfa-2465d2b0fe9d", "x509_sha512", Z },
58 { "4aafd29d-68df-49ee-8aa9-347d375665a7", "pkcs7_cert", Z },
59 { "605dab50-e046-4300-abb6-3dd810dd8b23", "shim", Z },
60 { "665d3f60-ad3e-4cad-8e26-db46eee9f1b5", "lenovo_rescue", Z },
61 { "67f8444f-8743-48f1-a328-1eaab8736080", "rsa2048_sha1", Z },
62 { "7076876e-80c2-4ee6-aad2-28b349a6865b", "x509_sha384", Z },
63 { "721c8b66-426c-4e86-8e99-3457c46ab0b9", "lenovo_setup", Z },
64 { "77fa9abd-0359-4d32-bd60-28f4e78f784b", "microsoft", Z },
65 { "7FACC7B6-127F-4E9C-9C5D-080F98994345", "lenovo_2", Z },
66 { "826ca512-cf10-4ac9-b187-be01496631bd", "sha1", Z },
67 { "82988420-7467-4490-9059-feb448dd1963", "lenovo_me_config", Z },
68 { "8be4df61-93ca-11d2-aa0d-00e098032b8c", "global", Z },
69 { "a5c059a1-94e4-4aa7-87b5-ab155c2bf072", "x509_cert", Z },
70 { "a7717414-c616-4977-9420-844712a735bf", "rsa2048_sha256_cert", Z },
71 { "a7d8d9a6-6ab0-4aeb-ad9d-163e59a7a380", "lenovo_diag_splash", Z },
72 { "ade9e48f-9cb8-98e6-31af-b4e6009e2fe3", "redhat_2", Z },
73 { "bc7838d2-0f82-4d60-8316-c068ee79d25b", "lenovo_msg", Z },
74 { "c1c41626-504c-4092-aca9-41f936934328", "sha256", Z },
75 { "c57ad6b7-0515-40a8-9d21-551652854e37", "shell", Z },
76 { "d719b2cb-3d3a-4596-a3bc-dad00e67656f", "security", Z },
77 { "e2b36190-879b-4a3d-ad8d-f2e7bba32784", "rsa2048_sha256", Z },
78 { "ff3e5307-9fd0-48c9-85f1-8ad56c701e01", "sha384", Z },
79 { "f46ee6f4-4785-43a3-923d-7f786c3c8479", "lenovo_startup_interrupt", Z },
80 { "ffffffff-ffff-ffff-ffff-ffffffffffff", "zzignore-this-guid", Z },
81 };
82 #undef Z
83
84 static void
efi_guid_tbl_compile(void)85 efi_guid_tbl_compile(void)
86 {
87 size_t i;
88 uint32_t status;
89 static int done = 0;
90
91 if (done)
92 return;
93 for (i = 0; i < nitems(guid_tbl); i++) {
94 uuid_from_string(guid_tbl[i].uuid_str, &guid_tbl[i].guid,
95 &status);
96 /* all f's is a bad version, so ignore that error */
97 if (status != uuid_s_ok && status != uuid_s_bad_version)
98 fprintf(stderr, "Can't convert %s to a uuid for %s: %d\n",
99 guid_tbl[i].uuid_str, guid_tbl[i].name, (int)status);
100 }
101 done = 1;
102 }
103
104 int
efi_known_guid(struct uuid_table ** tbl)105 efi_known_guid(struct uuid_table **tbl)
106 {
107
108 *tbl = guid_tbl;
109 return (nitems(guid_tbl));
110 }
111
112 static int
efi_open_dev(void)113 efi_open_dev(void)
114 {
115
116 if (efi_fd == -2)
117 efi_fd = open("/dev/efi", O_RDWR);
118 if (efi_fd < 0)
119 efi_fd = -1;
120 else
121 efi_guid_tbl_compile();
122 return (efi_fd);
123 }
124
125 static void
efi_var_reset(struct efi_var_ioc * var)126 efi_var_reset(struct efi_var_ioc *var)
127 {
128 var->name = NULL;
129 var->namesize = 0;
130 memset(&var->vendor, 0, sizeof(var->vendor));
131 var->attrib = 0;
132 var->data = NULL;
133 var->datasize = 0;
134 }
135
136 static int
rv_to_linux_rv(int rv)137 rv_to_linux_rv(int rv)
138 {
139 if (rv == 0)
140 rv = 1;
141 else
142 rv = -errno;
143 return (rv);
144 }
145
146 int
efi_append_variable(efi_guid_t guid,const char * name,uint8_t * data,size_t data_size,uint32_t attributes)147 efi_append_variable(efi_guid_t guid, const char *name,
148 uint8_t *data, size_t data_size, uint32_t attributes)
149 {
150
151 return efi_set_variable(guid, name, data, data_size,
152 attributes | EFI_VARIABLE_APPEND_WRITE);
153 }
154
155 int
efi_del_variable(efi_guid_t guid,const char * name)156 efi_del_variable(efi_guid_t guid, const char *name)
157 {
158
159 /* data_size of 0 deletes the variable */
160 return efi_set_variable(guid, name, NULL, 0, 0);
161 }
162
163 int
efi_get_variable(efi_guid_t guid,const char * name,uint8_t ** data,size_t * data_size,uint32_t * attributes)164 efi_get_variable(efi_guid_t guid, const char *name,
165 uint8_t **data, size_t *data_size, uint32_t *attributes)
166 {
167 struct efi_var_ioc var;
168 int rv;
169 static uint8_t buf[1024*32];
170
171 if (efi_open_dev() == -1)
172 return -1;
173
174 efi_var_reset(&var);
175 rv = utf8_to_ucs2(name, &var.name, &var.namesize);
176 if (rv != 0)
177 goto errout;
178 var.vendor = guid;
179 var.data = buf;
180 var.datasize = sizeof(buf);
181 rv = ioctl(efi_fd, EFIIOC_VAR_GET, &var);
182 if (data_size != NULL)
183 *data_size = var.datasize;
184 if (data != NULL)
185 *data = buf;
186 if (attributes != NULL)
187 *attributes = var.attrib;
188 errout:
189 free(var.name);
190
191 return rv_to_linux_rv(rv);
192 }
193
194 int
efi_get_variable_attributes(efi_guid_t guid,const char * name,uint32_t * attributes)195 efi_get_variable_attributes(efi_guid_t guid, const char *name,
196 uint32_t *attributes)
197 {
198 /* Make sure this construct works -- I think it will fail */
199
200 return efi_get_variable(guid, name, NULL, NULL, attributes);
201 }
202
203 int
efi_get_variable_size(efi_guid_t guid,const char * name,size_t * size)204 efi_get_variable_size(efi_guid_t guid, const char *name,
205 size_t *size)
206 {
207
208 /* XXX check to make sure this matches the linux value */
209
210 *size = 0;
211 return efi_get_variable(guid, name, NULL, size, NULL);
212 }
213
214 int
efi_get_next_variable_name(efi_guid_t ** guid,char ** name)215 efi_get_next_variable_name(efi_guid_t **guid, char **name)
216 {
217 struct efi_var_ioc var;
218 int rv;
219 static efi_char *buf;
220 static size_t buflen = 256 * sizeof(efi_char);
221 static efi_guid_t retguid;
222 size_t size;
223
224 if (efi_open_dev() == -1)
225 return -1;
226
227 /*
228 * Always allocate enough for an extra NUL on the end, but don't tell
229 * the IOCTL about it so we can NUL terminate the name before converting
230 * it to UTF8.
231 */
232 if (buf == NULL)
233 buf = malloc(buflen + sizeof(efi_char));
234
235 again:
236 efi_var_reset(&var);
237 var.name = buf;
238 var.namesize = buflen;
239 if (*name == NULL) {
240 *buf = 0;
241 /* GUID zeroed in var_reset */
242 } else {
243 rv = utf8_to_ucs2(*name, &var.name, &size);
244 if (rv != 0)
245 goto errout;
246 var.vendor = **guid;
247 }
248 rv = ioctl(efi_fd, EFIIOC_VAR_NEXT, &var);
249 if (rv == 0 && var.name == NULL) {
250 /*
251 * Variable name not long enough, so allocate more space for the
252 * name and try again. As above, mind the NUL we add.
253 */
254 void *new = realloc(buf, var.namesize + sizeof(efi_char));
255 if (new == NULL) {
256 rv = -1;
257 errno = ENOMEM;
258 goto done;
259 }
260 buflen = var.namesize;
261 buf = new;
262 goto again;
263 }
264
265 if (rv == 0) {
266 free(*name); /* Free last name, to avoid leaking */
267 *name = NULL; /* Force ucs2_to_utf8 to malloc new space */
268 var.name[var.namesize / sizeof(efi_char)] = 0; /* EFI doesn't NUL terminate */
269 rv = ucs2_to_utf8(var.name, name);
270 if (rv != 0)
271 goto errout;
272 retguid = var.vendor;
273 *guid = &retguid;
274 }
275 errout:
276
277 /* XXX The linux interface expects name to be a static buffer -- fix or leak memory? */
278 /* XXX for the moment, we free just before we'd leak, but still leak last one */
279 done:
280 if (rv != 0 && errno == ENOENT) {
281 errno = 0;
282 free(*name); /* Free last name, to avoid leaking */
283 return 0;
284 }
285
286 return (rv_to_linux_rv(rv));
287 }
288
289 int
efi_guid_cmp(const efi_guid_t * guid1,const efi_guid_t * guid2)290 efi_guid_cmp(const efi_guid_t *guid1, const efi_guid_t *guid2)
291 {
292 uint32_t status;
293
294 return uuid_compare(guid1, guid2, &status);
295 }
296
297 int
efi_guid_is_zero(const efi_guid_t * guid)298 efi_guid_is_zero(const efi_guid_t *guid)
299 {
300 uint32_t status;
301
302 return uuid_is_nil(guid, &status);
303 }
304
305 int
efi_guid_to_name(efi_guid_t * guid,char ** name)306 efi_guid_to_name(efi_guid_t *guid, char **name)
307 {
308 size_t i;
309 uint32_t status;
310
311 efi_guid_tbl_compile();
312 for (i = 0; i < nitems(guid_tbl); i++) {
313 if (uuid_equal(guid, &guid_tbl[i].guid, &status)) {
314 *name = strdup(guid_tbl[i].name);
315 return (0);
316 }
317 }
318 return (efi_guid_to_str(guid, name));
319 }
320
321 int
efi_guid_to_symbol(efi_guid_t * guid __unused,char ** symbol __unused)322 efi_guid_to_symbol(efi_guid_t *guid __unused, char **symbol __unused)
323 {
324
325 /*
326 * Unsure what this is used for, efibootmgr doesn't use it.
327 * Leave unimplemented for now.
328 */
329 return -1;
330 }
331
332 int
efi_guid_to_str(const efi_guid_t * guid,char ** sp)333 efi_guid_to_str(const efi_guid_t *guid, char **sp)
334 {
335 uint32_t status;
336
337 /* knows efi_guid_t is a typedef of uuid_t */
338 uuid_to_string(guid, sp, &status);
339
340 return (status == uuid_s_ok ? 0 : -1);
341 }
342
343 int
efi_name_to_guid(const char * name,efi_guid_t * guid)344 efi_name_to_guid(const char *name, efi_guid_t *guid)
345 {
346 size_t i;
347
348 efi_guid_tbl_compile();
349 for (i = 0; i < nitems(guid_tbl); i++) {
350 if (strcmp(name, guid_tbl[i].name) == 0) {
351 *guid = guid_tbl[i].guid;
352 return (0);
353 }
354 }
355 return (efi_str_to_guid(name, guid));
356 }
357
358 int
efi_set_variable(efi_guid_t guid,const char * name,uint8_t * data,size_t data_size,uint32_t attributes)359 efi_set_variable(efi_guid_t guid, const char *name,
360 uint8_t *data, size_t data_size, uint32_t attributes)
361 {
362 struct efi_var_ioc var;
363 int rv;
364
365 if (efi_open_dev() == -1)
366 return -1;
367
368 efi_var_reset(&var);
369 rv = utf8_to_ucs2(name, &var.name, &var.namesize);
370 if (rv != 0)
371 goto errout;
372 var.vendor = guid;
373 var.data = data;
374 var.datasize = data_size;
375 var.attrib = attributes;
376 rv = ioctl(efi_fd, EFIIOC_VAR_SET, &var);
377 errout:
378 free(var.name);
379
380 return rv;
381 }
382
383 int
efi_str_to_guid(const char * s,efi_guid_t * guid)384 efi_str_to_guid(const char *s, efi_guid_t *guid)
385 {
386 uint32_t status;
387
388 /* knows efi_guid_t is a typedef of uuid_t */
389 uuid_from_string(s, guid, &status);
390
391 return (status == uuid_s_ok ? 0 : -1);
392 }
393
394 int
efi_variables_supported(void)395 efi_variables_supported(void)
396 {
397
398 return efi_open_dev() != -1;
399 }
400