summaryrefslogtreecommitdiff
path: root/util/nvmutil/nvmutil.c
blob: e75ba6509bf1878f0a429d8407166a88e188a8d2 (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
/* 
 * Copyright (C) 2022, 2023 Leah Rowe <info@minifree.org>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

/*
 * This file is part of Libreboot. See:
 * https://libreboot.org/docs/install/nvmutil.html
 */

#include <sys/stat.h>

#include <dirent.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

void readGbeFile(int *fd, const char *path, int flags,
	size_t nr);
void cmd_setmac(const char *strMac);
int invalidMacAddress(const char *strMac, uint16_t *mac);
uint8_t hextonum(char chs);
uint8_t rhex(void);
void cmd_dump(void);
void showmac(int partnum);
void hexdump(int partnum);
void cmd_setchecksum(void);
void cmd_brick(void);
void cmd_swap(void);
void cmd_copy(void);
int validChecksum(int partnum);
uint16_t word(int pos16, int partnum);
void setWord(int pos16, int partnum, uint16_t val16);
void byteswap(int n, int partnum);
void writeGbeFile(int *fd, const char *filename, size_t nw);
void xpledge(const char *promises, const char *execpromises);
void xunveil(const char *path, const char *permissions);
void err_if(int condition);

#define FILENAME argv[1]
#define COMMAND argv[2]
#define MAC_ADDRESS argv[3]
#define PARTNUM argv[3]
#define SIZE_4KB 0x1000
#define SIZE_8KB 0x2000

uint16_t buf16[SIZE_4KB];
uint8_t *buf;
size_t gbe[2];
uint8_t skipread[2] = {0, 0};

int part, gbeFileModified = 0;
uint8_t nvmPartModified[2] = {0, 0};

uint16_t test;
uint8_t big_endian;

int
main(int argc, char *argv[])
{
	xpledge("stdio rpath wpath unveil", NULL);
	size_t nr = 128;
	int fd, flags = O_RDWR;
	void (*cmd)(void) = NULL;
	const char *strMac = NULL, *strRMac = "??:??:??:??:??:??";
	buf = (uint8_t *) &buf16;
	gbe[1] = (gbe[0] = (size_t) buf) + SIZE_4KB;

	test = 1;
	big_endian = ((uint8_t *) &test)[0] ^ 1;

	if (argc == 3) {
		if (strcmp(COMMAND, "dump") == 0) {
			xpledge("stdio rpath unveil", NULL);
			flags = O_RDONLY;
			cmd = &cmd_dump;
		} else if (strcmp(COMMAND, "setmac") == 0) {
			strMac = (char *) strRMac; /* random mac address */
		} else if (strcmp(COMMAND, "swap") == 0) {
			cmd = &cmd_swap;
			nr = SIZE_4KB;
		}
	} else if (argc == 4) {
		if (strcmp(COMMAND, "setmac") == 0) {
			strMac = MAC_ADDRESS; /* user-supplied mac address */
		} else if ((!((part = PARTNUM[0] - '0') == 0 || part == 1))
		|| PARTNUM[1]) { /* only allow '1' or '0' */
			errno = EINVAL;
		} else if (strcmp(COMMAND, "setchecksum") == 0) {
			cmd = &cmd_setchecksum;
		} else if (strcmp(COMMAND, "brick") == 0) {
			cmd = &cmd_brick;
		} else if (strcmp(COMMAND, "copy") == 0) {
			cmd = &cmd_copy;
			nr = SIZE_4KB;
		}
	}

	err_if(errno = ((strMac == NULL) && (cmd == NULL)) ? EINVAL : errno);

	skipread[part ^ 1] = (cmd == &cmd_copy) |
		(cmd == &cmd_setchecksum) | (cmd == &cmd_brick);
	readGbeFile(&fd, FILENAME, flags, nr);
	(void)rhex();
	xunveil("/dev/urandom", "r");
	if (flags == O_RDONLY) {
		xpledge("stdio", NULL);
	} else {
		xpledge("stdio wpath unveil", NULL);
		xunveil(FILENAME, "w");
	}

	if (strMac != NULL)
		cmd_setmac(strMac); /* nvm gbe.bin setmac */
	else if (cmd != NULL)
		(*cmd)(); /* all other commands except setmac */
	writeGbeFile(&fd, FILENAME, nr);

	err_if((errno != 0) && (cmd != &cmd_dump));
	return errno;
}

void
readGbeFile(int *fd, const char *path, int flags, size_t nr)
{
	struct stat st;
	if (opendir(path) != NULL)
		err(errno = EISDIR, "%s", path);
	else if (((*fd) = open(path, flags)) == -1)
		err(errno, "%s", path);
	else if (fstat((*fd), &st) == -1)
		err(errno, "%s", path);
	else if ((st.st_size != SIZE_8KB))
		err(errno = ECANCELED, "File `%s` not 8KiB", path);
	else if (errno == ENOTDIR)
		errno = 0;

	for (int p = 0; p < 2; p++) {
		if (skipread[p])
			continue;
		if (pread((*fd), (uint8_t *) gbe[p], nr, p << 12) == -1)
			err(errno, "%s", path);
		if (big_endian)
			byteswap(nr, p);
	}
}

void
cmd_setmac(const char *strMac)
{
	uint16_t mac[3] = {0, 0, 0};
	if (invalidMacAddress(strMac, mac))
		err(errno = ECANCELED, "Bad MAC address");

	for (int partnum = 0; partnum < 2; partnum++) {
		if (validChecksum(part = partnum)) {
			for (int w = 0; w < 3; w++)
				setWord(w, partnum, mac[w]);
			cmd_setchecksum();
		}
	}
}

int
invalidMacAddress(const char *strMac, uint16_t *mac)
{
	uint8_t h;
	uint64_t total = 0;
	if (strnlen(strMac, 20) == 17) {
	for (int i = 0; i < 16; i += 3) {
		if (i != 15)
			if (strMac[i + 2] != ':')
				return 1;
		int byte = i / 3;
		for (int nib = 0; nib < 2; nib++, total += h) {
			if ((h = hextonum(strMac[i + nib])) > 15)
				return 1;
			if ((byte == 0) && (nib == 1))
				if (strMac[i + nib] == '?')
					h = (h & 0xE) | 2; /* local, unicast */
			mac[byte >> 1] |= ((uint16_t ) h)
				<< ((8 * (byte % 2)) + (4 * (nib ^ 1)));
		}
	}}
	return ((total == 0) | (mac[0] & 1)); /* multicast/all-zero banned */
}

uint8_t
hextonum(char ch)
{
	if ((ch >= '0') && (ch <= '9'))
		return ch - '0';
	else if ((ch >= 'A') && (ch <= 'F'))
		return ch - 'A' + 10;
	else if ((ch >= 'a') && (ch <= 'f'))
		return ch - 'a' + 10;
	else if (ch == '?')
		return rhex(); /* random number */
	else
		return 16;
}

uint8_t
rhex(void)
{
	static int rfd = -1, n = 0;
	static uint8_t rnum[16];
	if (!n) {
		if (rfd == -1)
			if ((rfd = open("/dev/urandom", O_RDONLY)) == -1)
				err(errno, "/dev/urandom");
		if (read(rfd, (uint8_t *) &rnum, (n = 15) + 1) == -1)
			err(errno, "/dev/urandom");
	}
	return rnum[n--] & 0xf;
}

void
cmd_dump(void)
{
	int partnum, numInvalid = 0;
	for (partnum = 0; partnum < 2; partnum++) {
		if (!validChecksum(partnum))
			++numInvalid;
		printf("MAC (part %d): ", partnum);
		showmac(partnum);
		hexdump(partnum);
	}
	if (numInvalid < 2)
		errno = 0;
}

void
showmac(int partnum)
{
	uint16_t val16;
	for (int c = 0; c < 3; c++) {
		val16 = word(c, partnum);
		printf("%02x:%02x", val16 & 0xff, val16 >> 8);
		printf(c == 2 ? "\n" : ":");
	}
}

void
hexdump(int partnum)
{
	for (int row = 0; row < 8; row++) {
		printf("%07x", row << 4);
		for (int c = 0; c < 8; c++) {
			uint16_t val16 = word((row << 3) + c, partnum);
			printf(" %02x%02x", val16 >> 8, val16 & 0xff);
		}
		printf("\n");
	}
}

void
cmd_setchecksum(void)
{
	uint16_t val16 = 0;
	for (int c = 0; c < 0x3F; c++)
		val16 += word(c, part);
	setWord(0x3F, part, 0xBABA - val16);
}

void
cmd_brick(void)
{
	if (validChecksum(part))
		setWord(0x3F, part, (word(0x3F, part)) ^ 0xFF);
}

void
cmd_swap(void)
{
	gbe[0] ^= gbe[1]; /* speedhack: swap ptr, not words */
	gbe[1] ^= gbe[0];
	gbe[0] ^= gbe[1];
	gbeFileModified = nvmPartModified[0] = nvmPartModified[1]
		= validChecksum(1) | validChecksum(0);
}

void
cmd_copy(void)
{
	gbe[part ^ 1] = gbe[part]; /* speedhack: copy ptr, not words */
	gbeFileModified = nvmPartModified[part ^ 1] = validChecksum(part);
}

int
validChecksum(int partnum)
{
	uint16_t total = 0;
	for(int w = 0; w <= 0x3F; w++)
		total += word(w, partnum);
	if (total == 0xBABA)
		return 1;
	fprintf(stderr, "WARNING: BAD checksum in part %d\n", partnum);
	return (errno = ECANCELED) & 0;
}

uint16_t
word(int pos16, int partnum)
{
	return buf16[pos16 + (partnum << 11)];
}

void
setWord(int pos16, int partnum, uint16_t val16)
{
	gbeFileModified = 1;
	if (word(pos16, partnum) == val16)
		return;
	buf16[pos16 + (partnum << 11)] = val16;
	nvmPartModified[partnum] = 1;
}

void
byteswap(int n, int partnum)
{
	int b1, b2, wcount = n >> 1;
	uint8_t *nbuf = (uint8_t *) gbe[partnum];
	for (int w = 0; w < wcount; w++) {
		b1 = b2 = w << 1;
		nbuf[b1] ^= nbuf[++b2]; /* xor swap */
		nbuf[b2] ^= nbuf[b1];
		nbuf[b1] ^= nbuf[b2];
	}
}

void
writeGbeFile(int *fd, const char *filename, size_t nw)
{
	if (gbeFileModified)
		errno = 0;
	for (int p = 0; p < 2; p++) {
		if (gbe[0] > gbe[1])
			p ^= 1; /* speedhack: write sequentially on-disk */
		if (!nvmPartModified[p])
			goto next_part;
		if (big_endian)
			byteswap(nw, p);
		if (pwrite((*fd), (uint8_t *) gbe[p], nw, p << 12) == -1)
			err(errno, "%s", filename);
next_part:
		if (gbe[0] > gbe[1])
			p ^= 1; /* speedhack: write sequentially on-disk */
	}
	if (close((*fd)))
		err(errno, "%s", filename);
	xpledge("stdio", NULL);
}

void
xpledge(const char *promises, const char *execpromises)
{
	(void)promises; (void)execpromises;
#ifdef __OpenBSD__
	if (pledge(promises, execpromises) == -1)
		err(errno, NULL);
#endif
}

void
xunveil(const char *path, const char *permissions)
{
	(void)path; (void)permissions;
#ifdef __OpenBSD__
	if (unveil(path, permissions) == -1)
		err(errno, NULL);
#endif
}

void
err_if(int condition)
{
	if (!condition)
		return;
	if (!errno)
		errno = ECANCELED;
	err(errno, NULL);
}