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
40static int efi_fd = -2;
41
42#define Z { 0, 0, 0, 0, 0, { 0 } }
43
44const efi_guid_t efi_guid_empty = Z;
45
46static 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
84static void
85efi_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
104int
105efi_known_guid(struct uuid_table **tbl)
106{
107
108	*tbl = guid_tbl;
109	return (nitems(guid_tbl));
110}
111
112static int
113efi_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
125static void
126efi_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
136static int
137rv_to_linux_rv(int rv)
138{
139	if (rv == 0)
140		rv = 1;
141	else
142		rv = -errno;
143	return (rv);
144}
145
146int
147efi_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
155int
156efi_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
163int
164efi_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;
188errout:
189	free(var.name);
190
191	return rv_to_linux_rv(rv);
192}
193
194int
195efi_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
203int
204efi_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
214int
215efi_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
235again:
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	}
275errout:
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 */
279done:
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
289int
290efi_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
297int
298efi_guid_is_zero(const efi_guid_t *guid)
299{
300	uint32_t status;
301
302	return uuid_is_nil(guid, &status);
303}
304
305int
306efi_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
321int
322efi_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
332int
333efi_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
343int
344efi_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
358int
359efi_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);
377errout:
378	free(var.name);
379
380	return rv;
381}
382
383int
384efi_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
394int
395efi_variables_supported(void)
396{
397
398	return efi_open_dev() != -1;
399}
400