summaryrefslogtreecommitdiff
path: root/tools/bootconfig/main.c
blob: 4a445b6304bb724210216c899b2f94ffbf2033cd (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
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
// SPDX-License-Identifier: GPL-2.0
/*
 * Boot config tool for initrd image
 */
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>

#include <linux/kernel.h>
#include <linux/bootconfig.h>

static int xbc_show_value(struct xbc_node *node, bool semicolon)
{
	const char *val, *eol;
	char q;
	int i = 0;

	eol = semicolon ? ";\n" : "\n";
	xbc_array_for_each_value(node, val) {
		if (strchr(val, '"'))
			q = '\'';
		else
			q = '"';
		printf("%c%s%c%s", q, val, q, node->next ? ", " : eol);
		i++;
	}
	return i;
}

static void xbc_show_compact_tree(void)
{
	struct xbc_node *node, *cnode;
	int depth = 0, i;

	node = xbc_root_node();
	while (node && xbc_node_is_key(node)) {
		for (i = 0; i < depth; i++)
			printf("\t");
		cnode = xbc_node_get_child(node);
		while (cnode && xbc_node_is_key(cnode) && !cnode->next) {
			printf("%s.", xbc_node_get_data(node));
			node = cnode;
			cnode = xbc_node_get_child(node);
		}
		if (cnode && xbc_node_is_key(cnode)) {
			printf("%s {\n", xbc_node_get_data(node));
			depth++;
			node = cnode;
			continue;
		} else if (cnode && xbc_node_is_value(cnode)) {
			printf("%s = ", xbc_node_get_data(node));
			xbc_show_value(cnode, true);
		} else {
			printf("%s;\n", xbc_node_get_data(node));
		}

		if (node->next) {
			node = xbc_node_get_next(node);
			continue;
		}
		while (!node->next) {
			node = xbc_node_get_parent(node);
			if (!node)
				return;
			if (!xbc_node_get_child(node)->next)
				continue;
			depth--;
			for (i = 0; i < depth; i++)
				printf("\t");
			printf("}\n");
		}
		node = xbc_node_get_next(node);
	}
}

static void xbc_show_list(void)
{
	char key[XBC_KEYLEN_MAX];
	struct xbc_node *leaf;
	const char *val;
	int ret = 0;

	xbc_for_each_key_value(leaf, val) {
		ret = xbc_node_compose_key(leaf, key, XBC_KEYLEN_MAX);
		if (ret < 0)
			break;
		printf("%s = ", key);
		if (!val || val[0] == '\0') {
			printf("\"\"\n");
			continue;
		}
		xbc_show_value(xbc_node_get_child(leaf), false);
	}
}

/* Simple real checksum */
static int checksum(unsigned char *buf, int len)
{
	int i, sum = 0;

	for (i = 0; i < len; i++)
		sum += buf[i];

	return sum;
}

#define PAGE_SIZE	4096

static int load_xbc_fd(int fd, char **buf, int size)
{
	int ret;

	*buf = malloc(size + 1);
	if (!*buf)
		return -ENOMEM;

	ret = read(fd, *buf, size);
	if (ret < 0)
		return -errno;
	(*buf)[size] = '\0';

	return ret;
}

/* Return the read size or -errno */
static int load_xbc_file(const char *path, char **buf)
{
	struct stat stat;
	int fd, ret;

	fd = open(path, O_RDONLY);
	if (fd < 0)
		return -errno;
	ret = fstat(fd, &stat);
	if (ret < 0)
		return -errno;

	ret = load_xbc_fd(fd, buf, stat.st_size);

	close(fd);

	return ret;
}

static int pr_errno(const char *msg, int err)
{
	pr_err("%s: %d\n", msg, err);
	return err;
}

static int load_xbc_from_initrd(int fd, char **buf)
{
	struct stat stat;
	int ret;
	u32 size = 0, csum = 0, rcsum;
	char magic[BOOTCONFIG_MAGIC_LEN];
	const char *msg;

	ret = fstat(fd, &stat);
	if (ret < 0)
		return -errno;

	if (stat.st_size < 8 + BOOTCONFIG_MAGIC_LEN)
		return 0;

	if (lseek(fd, -BOOTCONFIG_MAGIC_LEN, SEEK_END) < 0)
		return pr_errno("Failed to lseek for magic", -errno);

	if (read(fd, magic, BOOTCONFIG_MAGIC_LEN) < 0)
		return pr_errno("Failed to read", -errno);

	/* Check the bootconfig magic bytes */
	if (memcmp(magic, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN) != 0)
		return 0;

	if (lseek(fd, -(8 + BOOTCONFIG_MAGIC_LEN), SEEK_END) < 0)
		return pr_errno("Failed to lseek for size", -errno);

	if (read(fd, &size, sizeof(u32)) < 0)
		return pr_errno("Failed to read size", -errno);

	if (read(fd, &csum, sizeof(u32)) < 0)
		return pr_errno("Failed to read checksum", -errno);

	/* Wrong size error  */
	if (stat.st_size < size + 8 + BOOTCONFIG_MAGIC_LEN) {
		pr_err("bootconfig size is too big\n");
		return -E2BIG;
	}

	if (lseek(fd, stat.st_size - (size + 8 + BOOTCONFIG_MAGIC_LEN),
		  SEEK_SET) < 0)
		return pr_errno("Failed to lseek", -errno);

	ret = load_xbc_fd(fd, buf, size);
	if (ret < 0)
		return ret;

	/* Wrong Checksum */
	rcsum = checksum((unsigned char *)*buf, size);
	if (csum != rcsum) {
		pr_err("checksum error: %d != %d\n", csum, rcsum);
		return -EINVAL;
	}

	ret = xbc_init(*buf, &msg, NULL);
	/* Wrong data */
	if (ret < 0) {
		pr_err("parse error: %s.\n", msg);
		return ret;
	}

	return size;
}

static void show_xbc_error(const char *data, const char *msg, int pos)
{
	int lin = 1, col, i;

	if (pos < 0) {
		pr_err("Error: %s.\n", msg);
		return;
	}

	/* Note that pos starts from 0 but lin and col should start from 1. */
	col = pos + 1;
	for (i = 0; i < pos; i++) {
		if (data[i] == '\n') {
			lin++;
			col = pos - i;
		}
	}
	pr_err("Parse Error: %s at %d:%d\n", msg, lin, col);

}

static int init_xbc_with_error(char *buf, int len)
{
	char *copy = strdup(buf);
	const char *msg;
	int ret, pos;

	if (!copy)
		return -ENOMEM;

	ret = xbc_init(buf, &msg, &pos);
	if (ret < 0)
		show_xbc_error(copy, msg, pos);
	free(copy);

	return ret;
}

static int show_xbc(const char *path, bool list)
{
	int ret, fd;
	char *buf = NULL;
	struct stat st;

	ret = stat(path, &st);
	if (ret < 0) {
		ret = -errno;
		pr_err("Failed to stat %s: %d\n", path, ret);
		return ret;
	}

	fd = open(path, O_RDONLY);
	if (fd < 0) {
		ret = -errno;
		pr_err("Failed to open initrd %s: %d\n", path, ret);
		return ret;
	}

	ret = load_xbc_from_initrd(fd, &buf);
	close(fd);
	if (ret < 0) {
		pr_err("Failed to load a boot config from initrd: %d\n", ret);
		goto out;
	}
	/* Assume a bootconfig file if it is enough small */
	if (ret == 0 && st.st_size <= XBC_DATA_MAX) {
		ret = load_xbc_file(path, &buf);
		if (ret < 0) {
			pr_err("Failed to load a boot config: %d\n", ret);
			goto out;
		}
		if (init_xbc_with_error(buf, ret) < 0)
			goto out;
	}
	if (list)
		xbc_show_list();
	else
		xbc_show_compact_tree();
	ret = 0;
out:
	free(buf);

	return ret;
}

static int delete_xbc(const char *path)
{
	struct stat stat;
	int ret = 0, fd, size;
	char *buf = NULL;

	fd = open(path, O_RDWR);
	if (fd < 0) {
		ret = -errno;
		pr_err("Failed to open initrd %s: %d\n", path, ret);
		return ret;
	}

	size = load_xbc_from_initrd(fd, &buf);
	if (size < 0) {
		ret = size;
		pr_err("Failed to load a boot config from initrd: %d\n", ret);
	} else if (size > 0) {
		ret = fstat(fd, &stat);
		if (!ret)
			ret = ftruncate(fd, stat.st_size
					- size - 8 - BOOTCONFIG_MAGIC_LEN);
		if (ret)
			ret = -errno;
	} /* Ignore if there is no boot config in initrd */

	close(fd);
	free(buf);

	return ret;
}

static int apply_xbc(const char *path, const char *xbc_path)
{
	char *buf, *data, *p;
	size_t total_size;
	struct stat stat;
	const char *msg;
	u32 size, csum;
	int pos, pad;
	int ret, fd;

	ret = load_xbc_file(xbc_path, &buf);
	if (ret < 0) {
		pr_err("Failed to load %s : %d\n", xbc_path, ret);
		return ret;
	}
	size = strlen(buf) + 1;
	csum = checksum((unsigned char *)buf, size);

	/* Backup the bootconfig data */
	data = calloc(size + BOOTCONFIG_ALIGN +
		      sizeof(u32) + sizeof(u32) + BOOTCONFIG_MAGIC_LEN, 1);
	if (!data)
		return -ENOMEM;
	memcpy(data, buf, size);

	/* Check the data format */
	ret = xbc_init(buf, &msg, &pos);
	if (ret < 0) {
		show_xbc_error(data, msg, pos);
		free(data);
		free(buf);

		return ret;
	}
	printf("Apply %s to %s\n", xbc_path, path);
	printf("\tNumber of nodes: %d\n", ret);
	printf("\tSize: %u bytes\n", (unsigned int)size);
	printf("\tChecksum: %d\n", (unsigned int)csum);

	/* TODO: Check the options by schema */
	xbc_destroy_all();
	free(buf);

	/* Remove old boot config if exists */
	ret = delete_xbc(path);
	if (ret < 0) {
		pr_err("Failed to delete previous boot config: %d\n", ret);
		free(data);
		return ret;
	}

	/* Apply new one */
	fd = open(path, O_RDWR | O_APPEND);
	if (fd < 0) {
		ret = -errno;
		pr_err("Failed to open %s: %d\n", path, ret);
		free(data);
		return ret;
	}
	/* TODO: Ensure the @path is initramfs/initrd image */
	if (fstat(fd, &stat) < 0) {
		pr_err("Failed to get the size of %s\n", path);
		goto out;
	}

	/* To align up the total size to BOOTCONFIG_ALIGN, get padding size */
	total_size = stat.st_size + size + sizeof(u32) * 2 + BOOTCONFIG_MAGIC_LEN;
	pad = ((total_size + BOOTCONFIG_ALIGN - 1) & (~BOOTCONFIG_ALIGN_MASK)) - total_size;
	size += pad;

	/* Add a footer */
	p = data + size;
	*(u32 *)p = size;
	p += sizeof(u32);

	*(u32 *)p = csum;
	p += sizeof(u32);

	memcpy(p, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN);
	p += BOOTCONFIG_MAGIC_LEN;

	total_size = p - data;

	ret = write(fd, data, total_size);
	if (ret < total_size) {
		if (ret < 0)
			ret = -errno;
		pr_err("Failed to apply a boot config: %d\n", ret);
		if (ret >= 0)
			goto out_rollback;
	} else
		ret = 0;

out:
	close(fd);
	free(data);

	return ret;

out_rollback:
	/* Map the partial write to -ENOSPC */
	if (ret >= 0)
		ret = -ENOSPC;
	if (ftruncate(fd, stat.st_size) < 0) {
		ret = -errno;
		pr_err("Failed to rollback the write error: %d\n", ret);
		pr_err("The initrd %s may be corrupted. Recommend to rebuild.\n", path);
	}
	goto out;
}

static int usage(void)
{
	printf("Usage: bootconfig [OPTIONS] <INITRD>\n"
		"Or     bootconfig <CONFIG>\n"
		" Apply, delete or show boot config to initrd.\n"
		" Options:\n"
		"		-a <config>: Apply boot config to initrd\n"
		"		-d : Delete boot config file from initrd\n"
		"		-l : list boot config in initrd or file\n\n"
		" If no option is given, show the bootconfig in the given file.\n");
	return -1;
}

int main(int argc, char **argv)
{
	char *path = NULL;
	char *apply = NULL;
	bool delete = false, list = false;
	int opt;

	while ((opt = getopt(argc, argv, "hda:l")) != -1) {
		switch (opt) {
		case 'd':
			delete = true;
			break;
		case 'a':
			apply = optarg;
			break;
		case 'l':
			list = true;
			break;
		case 'h':
		default:
			return usage();
		}
	}

	if ((apply && delete) || (delete && list) || (apply && list)) {
		pr_err("Error: You can give one of -a, -d or -l at once.\n");
		return usage();
	}

	if (optind >= argc) {
		pr_err("Error: No initrd is specified.\n");
		return usage();
	}

	path = argv[optind];

	if (apply)
		return apply_xbc(path, apply);
	else if (delete)
		return delete_xbc(path);

	return show_xbc(path, list);
}