aboutsummaryrefslogtreecommitdiffstats
path: root/dmi.c
blob: 4137821805b773e8fedc4c590e7e1b1fb52c9570 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
/*
 * This file is part of the flashrom project.
 *
 * Copyright (C) 2000-2002 Alan Cox <alan@redhat.com>
 * Copyright (C) 2002-2010 Jean Delvare <khali@linux-fr.org>
 * Copyright (C) 2009,2010 Michael Karcher
 * Copyright (C) 2011-2013 Stefan Tauner
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

/* strnlen is in POSIX but was a GNU extension up to glibc 2.10 */
#if (__GLIBC__ == 2 && __GLIBC_MINOR__ < 10) || __GLIBC__ < 2
#define _GNU_SOURCE
#else
#define _POSIX_C_SOURCE 200809L
#endif

#include <strings.h>
#include <string.h>
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>

#include "platform.h"
#include "flash.h"
#include "programmer.h"

#if defined(__i386__) || defined(__x86_64__)

/* Enable SMBIOS decoding. Currently legacy DMI decoding is enough. */
#define SM_SUPPORT 0

/* Strings longer than 4096 in DMI are just insane. */
#define DMI_MAX_ANSWER_LEN 4096

int has_dmi_support = 0;

static struct {
	const char *const keyword;
	const uint8_t type;
	const uint8_t offset;
	char *value;
} dmi_strings[] = {
	{ "system-manufacturer", 1, 0x04, NULL },
	{ "system-product-name", 1, 0x05, NULL },
	{ "system-version", 1, 0x06, NULL },
	{ "baseboard-manufacturer", 2, 0x04, NULL },
	{ "baseboard-product-name", 2, 0x05, NULL },
	{ "baseboard-version", 2, 0x06, NULL },
};

/* This list is used to identify supposed laptops. The is_laptop field has the
 * following meaning:
 *	- 0: in all likelihood not a laptop
 *	- 1: in all likelihood a laptop
 *	- 2: chassis-type is not specific enough
 * A full list of chassis types can be found in the System Management BIOS
 * (SMBIOS) Reference Specification 2.7.0 section 7.4.1 "Chassis Types" at
 * http://www.dmtf.org/sites/default/files/standards/documents/DSP0134_2.7.0.pdf
 * The types below are the most common ones.
 */
static const struct {
	uint8_t type;
	uint8_t is_laptop;
	char *name;
} dmi_chassis_types[] = {
	{0x01, 2, "Other"},
	{0x02, 2, "Unknown"},
	{0x03, 0, "Desktop"},
	{0x04, 0, "Low Profile Desktop"},
	{0x06, 0, "Mini Tower"},
	{0x07, 0, "Tower"},
	{0x08, 1, "Portable"},
	{0x09, 1, "Laptop"},
	{0x0a, 1, "Notebook"},
	{0x0b, 1, "Hand Held"},
	{0x0e, 1, "Sub Notebook"},
	{0x11, 0, "Main Server Chassis"},
	{0x17, 0, "Rack Mount Chassis"},
	{0x18, 0, "Sealed-case PC"}, /* used by Supermicro (X8SIE) */
	{0x19, 0, "Multi-system"}, /* used by Supermicro (X7DWT) */
};

#if CONFIG_INTERNAL_DMI == 1
static bool dmi_checksum(const uint8_t * const buf, size_t len)
{
	uint8_t sum = 0;
	size_t a;

	for (a = 0; a < len; a++)
		sum += buf[a];
	return (sum == 0);
}

/** Retrieve a DMI string.
 *
 * See SMBIOS spec. section 6.1.3 "Text strings".
 * The table will be unmapped ASAP, hence return a duplicated & sanitized string that needs to be freed later.
 *
 * \param buf		the buffer to search through (usually appended directly to a DMI structure)
 * \param string_id	index of the string to look for
 * \param limit		pointer to the first byte beyond \em buf
 */
static char *dmi_string(const char *buf, uint8_t string_id, const char *limit)
{
	size_t i, len;

	if (string_id == 0)
		return strdup("Not Specified");

	while (string_id > 1 && string_id--) {
		if (buf >= limit) {
			msg_perr("DMI table is broken (string portion out of bounds)!\n");
			return strdup("<OUT OF BOUNDS>");
		}
		buf += strnlen(buf, limit - buf) + 1;
	}

	if (!*buf) /* as long as the current byte we're on isn't null */
		return strdup("<BAD INDEX>");

	len = strnlen(buf, limit - buf);
	char *newbuf = malloc(len + 1);
	if (newbuf == NULL) {
		msg_perr("Out of memory!\n");
		return NULL;
	}

	/* fix junk bytes in the string */
	for (i = 0; i < len && buf[i] != '\0'; i++) {
		if (isprint((unsigned char)buf[i]))
			newbuf[i] = buf[i];
		else
			newbuf[i] = ' ';
	}
	newbuf[i] = '\0';

	return newbuf;
}

static void dmi_chassis_type(uint8_t code)
{
	int i;
	code &= 0x7f; /* bits 6:0 are chassis type, 7th bit is the lock bit */
	is_laptop = 2;
	for (i = 0; i < ARRAY_SIZE(dmi_chassis_types); i++) {
		if (code == dmi_chassis_types[i].type) {
			msg_pdbg("DMI string chassis-type: \"%s\"\n", dmi_chassis_types[i].name);
			is_laptop = dmi_chassis_types[i].is_laptop;
			break;
		}
	}
}

static void dmi_table(uint32_t base, uint16_t len, uint16_t num)
{
	int i = 0, j = 0;

	uint8_t *dmi_table_mem = physmap_ro("DMI Table", base, len);
	if (dmi_table_mem == NULL) {
		msg_perr("Unable to access DMI Table\n");
		return;
	}

	uint8_t *data = dmi_table_mem;
	uint8_t *limit = dmi_table_mem + len;

	/* SMBIOS structure header is always 4 B long and contains:
	 *  - uint8_t type;	// see dmi_chassis_types's type
	 *  - uint8_t length;	// data section w/ header w/o strings
	 *  - uint16_t handle;
	 */
	while (i < num && data + 4 < limit) {
		/* - If a short entry is found (less than 4 bytes), not only it
		 *   is invalid, but we cannot reliably locate the next entry.
		 * - If the length value indicates that this structure spreads
		 *   across the table border, something is fishy too.
		 * Better stop at this point, and let the user know his/her
		 * table is broken.
		 */
		if (data[1] < 4 || data + data[1] >= limit) {
			msg_perr("DMI table is broken (bogus header)!\n");
			break;
		}

		if(data[0] == 3) {
			if (data + 5 < limit)
				dmi_chassis_type(data[5]);
			else /* the table is broken, but laptop detection is optional, hence continue. */
				msg_pwarn("DMI table is broken (chassis_type out of bounds)!\n");
		} else
			for (j = 0; j < ARRAY_SIZE(dmi_strings); j++) {
				uint8_t offset = dmi_strings[j].offset;
				uint8_t type = dmi_strings[j].type;

				if (data[0] != type)
					continue;

				if (data[1] <= offset || data + offset >= limit) {
					msg_perr("DMI table is broken (offset out of bounds)!\n");
					goto out;
				}

				dmi_strings[j].value = dmi_string((const char *)(data + data[1]), data[offset],
								  (const char *)limit);
			}
		/* Find next structure by skipping data and string sections */
		data += data[1];
		while (data + 1 <= limit) {
			if (data[0] == 0 && data[1] == 0)
				break;
			data++;
		}
		data += 2;
		i++;
	}
out:
	physunmap(dmi_table_mem, len);
}

#if SM_SUPPORT
static int smbios_decode(uint8_t *buf)
{
	/* TODO: other checks mentioned in the conformance guidelines? */
	if (!dmi_checksum(buf, buf[0x05]) ||
	    (memcmp(buf + 0x10, "_DMI_", 5) != 0) ||
	    !dmi_checksum(buf + 0x10, 0x0F))
			return 0;

	dmi_table(mmio_readl(buf + 0x18), mmio_readw(buf + 0x16), mmio_readw(buf + 0x1C));

	return 1;
}
#endif

static int legacy_decode(uint8_t *buf)
{
	if (!dmi_checksum(buf, 0x0F))
		return 1;

	dmi_table(mmio_readl(buf + 0x08), mmio_readw(buf + 0x06), mmio_readw(buf + 0x0C));

	return 0;
}

int dmi_fill(void)
{
	size_t fp;
	uint8_t *dmi_mem;
	int ret = 1;

	msg_pdbg("Using Internal DMI decoder.\n");
	/* There are two ways specified to gain access to the SMBIOS table:
	 * - EFI's configuration table contains a pointer to the SMBIOS table. On linux it can be obtained from
	 *   sysfs. EFI's SMBIOS GUID is: {0xeb9d2d31,0x2d88,0x11d3,0x9a,0x16,0x0,0x90,0x27,0x3f,0xc1,0x4d}
	 * - Scanning physical memory address range 0x000F0000h to 0x000FFFFF for the anchor-string(s). */
	dmi_mem = physmap_ro("DMI", 0xF0000, 0x10000);
	if (dmi_mem == ERROR_PTR)
		return ret;

	for (fp = 0; fp <= 0xFFF0; fp += 16) {
#if SM_SUPPORT
		if (memcmp(dmi_mem + fp, "_SM_", 4) == 0 && fp <= 0xFFE0) {
			if (smbios_decode(dmi_mem + fp)) // FIXME: length check
				goto out;
		} else
#endif
		if (memcmp(dmi_mem + fp, "_DMI_", 5) == 0)
			if (legacy_decode(dmi_mem + fp) == 0) {
				ret = 0;
				goto out;
			}
	}
	msg_pinfo("No DMI table found.\n");
out:
	physunmap(dmi_mem, 0x10000);
	return ret;
}

#else /* CONFIG_INTERNAL_DMI */

#define DMI_COMMAND_LEN_MAX 300
#if IS_WINDOWS
static const char *dmidecode_command = "dmidecode.exe 2>NUL";
#else
static const char *dmidecode_command = "dmidecode 2>/dev/null";
#endif

static char *get_dmi_string(const char *string_name)
{
	FILE *dmidecode_pipe;
	char *result;
	char answerbuf[DMI_MAX_ANSWER_LEN];
	char commandline[DMI_COMMAND_LEN_MAX];

	snprintf(commandline, sizeof(commandline),
		 "%s -s %s", dmidecode_command, string_name);
	dmidecode_pipe = popen(commandline, "r");
	if (!dmidecode_pipe) {
		msg_perr("Opening DMI pipe failed!\n");
		return NULL;
	}

	/* Kill lines starting with '#', as recent dmidecode versions
	 * have the quirk to emit a "# SMBIOS implementations newer..."
	 * message even on "-s" if the SMBIOS declares a
	 * newer-than-supported version number, while it *should* only print
	 * the requested string.
	 */
	do {
		if (!fgets(answerbuf, DMI_MAX_ANSWER_LEN, dmidecode_pipe)) {
			if (ferror(dmidecode_pipe)) {
				msg_perr("DMI pipe read error\n");
				pclose(dmidecode_pipe);
				return NULL;
			} else {
				answerbuf[0] = 0;	/* Hit EOF */
			}
		}
	} while (answerbuf[0] == '#');

	/* Discard all output exceeding DMI_MAX_ANSWER_LEN to prevent deadlock on pclose. */
	while (!feof(dmidecode_pipe))
		getc(dmidecode_pipe);
	if (pclose(dmidecode_pipe) != 0) {
		msg_pwarn("dmidecode execution unsuccessful - continuing without DMI info\n");
		return NULL;
	}

	/* Chomp trailing newline. */
	if (answerbuf[0] != 0 && answerbuf[strlen(answerbuf) - 1] == '\n')
		answerbuf[strlen(answerbuf) - 1] = 0;

	result = strdup(answerbuf);
	if (result == NULL)
		msg_pwarn("Warning: Out of memory - DMI support fails");

	return result;
}

int dmi_fill(void)
{
	int i;
	char *chassis_type;

	msg_pdbg("Using External DMI decoder.\n");
	for (i = 0; i < ARRAY_SIZE(dmi_strings); i++) {
		dmi_strings[i].value = get_dmi_string(dmi_strings[i].keyword);
		if (dmi_strings[i].value == NULL)
			return 1;
	}

	chassis_type = get_dmi_string("chassis-type");
	if (chassis_type == NULL)
		return 0; /* chassis-type handling is optional anyway */

	msg_pdbg("DMI string chassis-type: \"%s\"\n", chassis_type);
	is_laptop = 2;
	for (i = 0; i < ARRAY_SIZE(dmi_chassis_types); i++) {
		if (strcasecmp(chassis_type, dmi_chassis_types[i].name) == 0) {
			is_laptop = dmi_chassis_types[i].is_laptop;
			break;
		}
	}
	free(chassis_type);
	return 0;
}

#endif /* CONFIG_INTERNAL_DMI */

static int dmi_shutdown(void *data)
{
	int i;
	for (i = 0; i < ARRAY_SIZE(dmi_strings); i++) {
		free(dmi_strings[i].value);
		dmi_strings[i].value = NULL;
	}
	return 0;
}

void dmi_init(void)
{
	/* Register shutdown function before we allocate anything. */
	if (register_shutdown(dmi_shutdown, NULL)) {
		msg_pwarn("Warning: Could not register DMI shutdown function - continuing without DMI info.\n");
		return;
	}

	/* dmi_fill fills the dmi_strings array, and if possible sets the global is_laptop variable. */
	if (dmi_fill() != 0)
		return;

	switch (is_laptop) {
	case 1:
		msg_pdbg("Laptop detected via DMI.\n");
		break;
	case 2:
		msg_pdbg("DMI chassis-type is not specific enough.\n");
		break;
	}

	has_dmi_support = 1;
	int i;
	for (i = 0; i < ARRAY_SIZE(dmi_strings); i++) {
		msg_pdbg("DMI string %s: \"%s\"\n", dmi_strings[i].keyword,
			 (dmi_strings[i].value == NULL) ? "" : dmi_strings[i].value);
	}
}

/**
 * Does an substring/prefix/postfix/whole-string match.
 *
 * The pattern is matched as-is. The only metacharacters supported are '^'
 * at the beginning and '$' at the end. So you can look for "^prefix",
 * "suffix$", "substring" or "^complete string$".
 *
 * @param value The non-NULL string to check.
 * @param pattern The non-NULL pattern.
 * @return Nonzero if pattern matches.
 */
static int dmi_compare(const char *value, const char *pattern)
{
	int anchored = 0;
	int patternlen;

	msg_pspew("matching %s against %s\n", value, pattern);
	/* The empty string is part of all strings! */
	if (pattern[0] == 0)
		return 1;

	if (pattern[0] == '^') {
		anchored = 1;
		pattern++;
	}

	patternlen = strlen(pattern);
	if (pattern[patternlen - 1] == '$') {
		int valuelen = strlen(value);
		patternlen--;
		if (patternlen > valuelen)
			return 0;

		/* full string match: require same length */
		if (anchored && (valuelen != patternlen))
			return 0;

		/* start character to make ends match */
		value += valuelen - patternlen;
		anchored = 1;
	}

	if (anchored)
		return strncmp(value, pattern, patternlen) == 0;
	else
		return strstr(value, pattern) != NULL;
}

int dmi_match(const char *pattern)
{
	int i;

	if (!has_dmi_support)
		return 0;

	for (i = 0; i < ARRAY_SIZE(dmi_strings); i++) {
		if (dmi_strings[i].value == NULL)
			continue;

		if (dmi_compare(dmi_strings[i].value, pattern))
			return 1;
	}

	return 0;
}

#endif // defined(__i386__) || defined(__x86_64__)