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
38static int efi_fd = -2;
39
40#define Z { 0, 0, 0, 0, 0, { 0 } }
41
42const efi_guid_t efi_guid_empty = Z;
43
44static 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
82static void
83efi_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
102int
103efi_known_guid(struct uuid_table **tbl)
104{
105
106	*tbl = guid_tbl;
107	return (nitems(guid_tbl));
108}
109
110static int
111efi_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
123static void
124efi_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
134static int
135rv_to_linux_rv(int rv)
136{
137	if (rv == 0)
138		rv = 1;
139	else
140		rv = -errno;
141	return (rv);
142}
143
144int
145efi_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
153int
154efi_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
161int
162efi_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;
186errout:
187	free(var.name);
188
189	return rv_to_linux_rv(rv);
190}
191
192int
193efi_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
201int
202efi_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
212int
213efi_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
233again:
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	}
273errout:
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 */
277done:
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
287int
288efi_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
295int
296efi_guid_is_zero(const efi_guid_t *guid)
297{
298	uint32_t status;
299
300	return uuid_is_nil(guid, &status);
301}
302
303int
304efi_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
319int
320efi_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
330int
331efi_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
341int
342efi_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
356int
357efi_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);
375errout:
376	free(var.name);
377
378	return rv;
379}
380
381int
382efi_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
392int
393efi_variables_supported(void)
394{
395
396	return efi_open_dev() != -1;
397}
398