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
efi_guid_tbl_compile(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
efi_known_guid(struct uuid_table ** tbl)103 efi_known_guid(struct uuid_table **tbl)
104 {
105
106 *tbl = guid_tbl;
107 return (nitems(guid_tbl));
108 }
109
110 static int
efi_open_dev(void)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
efi_var_reset(struct efi_var_ioc * var)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
rv_to_linux_rv(int rv)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
efi_append_variable(efi_guid_t guid,const char * name,uint8_t * data,size_t data_size,uint32_t attributes)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
efi_del_variable(efi_guid_t guid,const char * name)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
efi_get_variable(efi_guid_t guid,const char * name,uint8_t ** data,size_t * data_size,uint32_t * attributes)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
efi_get_variable_attributes(efi_guid_t guid,const char * name,uint32_t * attributes)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
efi_get_variable_size(efi_guid_t guid,const char * name,size_t * size)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
efi_get_next_variable_name(efi_guid_t ** guid,char ** name)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
efi_guid_cmp(const efi_guid_t * guid1,const efi_guid_t * guid2)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
efi_guid_is_zero(const efi_guid_t * guid)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
efi_guid_to_name(efi_guid_t * guid,char ** name)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
efi_guid_to_symbol(efi_guid_t * guid __unused,char ** symbol __unused)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
efi_guid_to_str(const efi_guid_t * guid,char ** sp)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
efi_name_to_guid(const char * name,efi_guid_t * guid)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
efi_set_variable(efi_guid_t guid,const char * name,uint8_t * data,size_t data_size,uint32_t attributes)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
efi_str_to_guid(const char * s,efi_guid_t * guid)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
efi_variables_supported(void)393 efi_variables_supported(void)
394 {
395
396 return efi_open_dev() != -1;
397 }
398