aboutsummaryrefslogtreecommitdiff
path: root/usr/gen_init_cpio.c
blob: dc838e26a5b9aa796fdcf867a2563e90d573cb58 (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
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
// SPDX-License-Identifier: GPL-2.0
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdbool.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#include <unistd.h>
#include <time.h>
#include <fcntl.h>
#include <errno.h>
#include <ctype.h>
#include <limits.h>

/*
 * Original work by Jeff Garzik
 *
 * External file lists, symlink, pipe and fifo support by Thayne Harbaugh
 * Hard link support by Luciano Rocha
 */

#define xstr(s) #s
#define str(s) xstr(s)
#define MIN(a, b) ((a) < (b) ? (a) : (b))

static unsigned int offset;
static unsigned int ino = 721;
static time_t default_mtime;
static bool do_csum = false;

struct file_handler {
	const char *type;
	int (*handler)(const char *line);
};

static void push_string(const char *name)
{
	unsigned int name_len = strlen(name) + 1;

	fputs(name, stdout);
	putchar(0);
	offset += name_len;
}

static void push_pad (void)
{
	while (offset & 3) {
		putchar(0);
		offset++;
	}
}

static void push_rest(const char *name)
{
	unsigned int name_len = strlen(name) + 1;
	unsigned int tmp_ofs;

	fputs(name, stdout);
	putchar(0);
	offset += name_len;

	tmp_ofs = name_len + 110;
	while (tmp_ofs & 3) {
		putchar(0);
		offset++;
		tmp_ofs++;
	}
}

static void push_hdr(const char *s)
{
	fputs(s, stdout);
	offset += 110;
}

static void cpio_trailer(void)
{
	char s[256];
	const char name[] = "TRAILER!!!";

	sprintf(s, "%s%08X%08X%08lX%08lX%08X%08lX"
	       "%08X%08X%08X%08X%08X%08X%08X",
		do_csum ? "070702" : "070701", /* magic */
		0,			/* ino */
		0,			/* mode */
		(long) 0,		/* uid */
		(long) 0,		/* gid */
		1,			/* nlink */
		(long) 0,		/* mtime */
		0,			/* filesize */
		0,			/* major */
		0,			/* minor */
		0,			/* rmajor */
		0,			/* rminor */
		(unsigned)strlen(name)+1, /* namesize */
		0);			/* chksum */
	push_hdr(s);
	push_rest(name);

	while (offset % 512) {
		putchar(0);
		offset++;
	}
}

static int cpio_mkslink(const char *name, const char *target,
			 unsigned int mode, uid_t uid, gid_t gid)
{
	char s[256];

	if (name[0] == '/')
		name++;
	sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
	       "%08X%08X%08X%08X%08X%08X%08X",
		do_csum ? "070702" : "070701", /* magic */
		ino++,			/* ino */
		S_IFLNK | mode,		/* mode */
		(long) uid,		/* uid */
		(long) gid,		/* gid */
		1,			/* nlink */
		(long) default_mtime,	/* mtime */
		(unsigned)strlen(target)+1, /* filesize */
		3,			/* major */
		1,			/* minor */
		0,			/* rmajor */
		0,			/* rminor */
		(unsigned)strlen(name) + 1,/* namesize */
		0);			/* chksum */
	push_hdr(s);
	push_string(name);
	push_pad();
	push_string(target);
	push_pad();
	return 0;
}

static int cpio_mkslink_line(const char *line)
{
	char name[PATH_MAX + 1];
	char target[PATH_MAX + 1];
	unsigned int mode;
	int uid;
	int gid;
	int rc = -1;

	if (5 != sscanf(line, "%" str(PATH_MAX) "s %" str(PATH_MAX) "s %o %d %d", name, target, &mode, &uid, &gid)) {
		fprintf(stderr, "Unrecognized dir format '%s'", line);
		goto fail;
	}
	rc = cpio_mkslink(name, target, mode, uid, gid);
 fail:
	return rc;
}

static int cpio_mkgeneric(const char *name, unsigned int mode,
		       uid_t uid, gid_t gid)
{
	char s[256];

	if (name[0] == '/')
		name++;
	sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
	       "%08X%08X%08X%08X%08X%08X%08X",
		do_csum ? "070702" : "070701", /* magic */
		ino++,			/* ino */
		mode,			/* mode */
		(long) uid,		/* uid */
		(long) gid,		/* gid */
		2,			/* nlink */
		(long) default_mtime,	/* mtime */
		0,			/* filesize */
		3,			/* major */
		1,			/* minor */
		0,			/* rmajor */
		0,			/* rminor */
		(unsigned)strlen(name) + 1,/* namesize */
		0);			/* chksum */
	push_hdr(s);
	push_rest(name);
	return 0;
}

enum generic_types {
	GT_DIR,
	GT_PIPE,
	GT_SOCK
};

struct generic_type {
	const char *type;
	mode_t mode;
};

static const struct generic_type generic_type_table[] = {
	[GT_DIR] = {
		.type = "dir",
		.mode = S_IFDIR
	},
	[GT_PIPE] = {
		.type = "pipe",
		.mode = S_IFIFO
	},
	[GT_SOCK] = {
		.type = "sock",
		.mode = S_IFSOCK
	}
};

static int cpio_mkgeneric_line(const char *line, enum generic_types gt)
{
	char name[PATH_MAX + 1];
	unsigned int mode;
	int uid;
	int gid;
	int rc = -1;

	if (4 != sscanf(line, "%" str(PATH_MAX) "s %o %d %d", name, &mode, &uid, &gid)) {
		fprintf(stderr, "Unrecognized %s format '%s'",
			line, generic_type_table[gt].type);
		goto fail;
	}
	mode |= generic_type_table[gt].mode;
	rc = cpio_mkgeneric(name, mode, uid, gid);
 fail:
	return rc;
}

static int cpio_mkdir_line(const char *line)
{
	return cpio_mkgeneric_line(line, GT_DIR);
}

static int cpio_mkpipe_line(const char *line)
{
	return cpio_mkgeneric_line(line, GT_PIPE);
}

static int cpio_mksock_line(const char *line)
{
	return cpio_mkgeneric_line(line, GT_SOCK);
}

static int cpio_mknod(const char *name, unsigned int mode,
		       uid_t uid, gid_t gid, char dev_type,
		       unsigned int maj, unsigned int min)
{
	char s[256];

	if (dev_type == 'b')
		mode |= S_IFBLK;
	else
		mode |= S_IFCHR;

	if (name[0] == '/')
		name++;
	sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
	       "%08X%08X%08X%08X%08X%08X%08X",
		do_csum ? "070702" : "070701", /* magic */
		ino++,			/* ino */
		mode,			/* mode */
		(long) uid,		/* uid */
		(long) gid,		/* gid */
		1,			/* nlink */
		(long) default_mtime,	/* mtime */
		0,			/* filesize */
		3,			/* major */
		1,			/* minor */
		maj,			/* rmajor */
		min,			/* rminor */
		(unsigned)strlen(name) + 1,/* namesize */
		0);			/* chksum */
	push_hdr(s);
	push_rest(name);
	return 0;
}

static int cpio_mknod_line(const char *line)
{
	char name[PATH_MAX + 1];
	unsigned int mode;
	int uid;
	int gid;
	char dev_type;
	unsigned int maj;
	unsigned int min;
	int rc = -1;

	if (7 != sscanf(line, "%" str(PATH_MAX) "s %o %d %d %c %u %u",
			 name, &mode, &uid, &gid, &dev_type, &maj, &min)) {
		fprintf(stderr, "Unrecognized nod format '%s'", line);
		goto fail;
	}
	rc = cpio_mknod(name, mode, uid, gid, dev_type, maj, min);
 fail:
	return rc;
}

static int cpio_mkfile_csum(int fd, unsigned long size, uint32_t *csum)
{
	while (size) {
		unsigned char filebuf[65536];
		ssize_t this_read;
		size_t i, this_size = MIN(size, sizeof(filebuf));

		this_read = read(fd, filebuf, this_size);
		if (this_read <= 0 || this_read > this_size)
			return -1;

		for (i = 0; i < this_read; i++)
			*csum += filebuf[i];

		size -= this_read;
	}
	/* seek back to the start for data segment I/O */
	if (lseek(fd, 0, SEEK_SET) < 0)
		return -1;

	return 0;
}

static int cpio_mkfile(const char *name, const char *location,
			unsigned int mode, uid_t uid, gid_t gid,
			unsigned int nlinks)
{
	char s[256];
	struct stat buf;
	unsigned long size;
	int file = -1;
	int retval;
	int rc = -1;
	int namesize;
	unsigned int i;
	uint32_t csum = 0;

	mode |= S_IFREG;

	file = open (location, O_RDONLY);
	if (file < 0) {
		fprintf (stderr, "File %s could not be opened for reading\n", location);
		goto error;
	}

	retval = fstat(file, &buf);
	if (retval) {
		fprintf(stderr, "File %s could not be stat()'ed\n", location);
		goto error;
	}

	if (buf.st_mtime > 0xffffffff) {
		fprintf(stderr, "%s: Timestamp exceeds maximum cpio timestamp, clipping.\n",
			location);
		buf.st_mtime = 0xffffffff;
	}

	if (buf.st_size > 0xffffffff) {
		fprintf(stderr, "%s: Size exceeds maximum cpio file size\n",
			location);
		goto error;
	}

	if (do_csum && cpio_mkfile_csum(file, buf.st_size, &csum) < 0) {
		fprintf(stderr, "Failed to checksum file %s\n", location);
		goto error;
	}

	size = 0;
	for (i = 1; i <= nlinks; i++) {
		/* data goes on last link */
		if (i == nlinks)
			size = buf.st_size;

		if (name[0] == '/')
			name++;
		namesize = strlen(name) + 1;
		sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
		       "%08lX%08X%08X%08X%08X%08X%08X",
			do_csum ? "070702" : "070701", /* magic */
			ino,			/* ino */
			mode,			/* mode */
			(long) uid,		/* uid */
			(long) gid,		/* gid */
			nlinks,			/* nlink */
			(long) buf.st_mtime,	/* mtime */
			size,			/* filesize */
			3,			/* major */
			1,			/* minor */
			0,			/* rmajor */
			0,			/* rminor */
			namesize,		/* namesize */
			size ? csum : 0);	/* chksum */
		push_hdr(s);
		push_string(name);
		push_pad();

		while (size) {
			unsigned char filebuf[65536];
			ssize_t this_read;
			size_t this_size = MIN(size, sizeof(filebuf));

			this_read = read(file, filebuf, this_size);
			if (this_read <= 0 || this_read > this_size) {
				fprintf(stderr, "Can not read %s file\n", location);
				goto error;
			}

			if (fwrite(filebuf, this_read, 1, stdout) != 1) {
				fprintf(stderr, "writing filebuf failed\n");
				goto error;
			}
			offset += this_read;
			size -= this_read;
		}
		push_pad();

		name += namesize;
	}
	ino++;
	rc = 0;

error:
	if (file >= 0)
		close(file);
	return rc;
}

static char *cpio_replace_env(char *new_location)
{
	char expanded[PATH_MAX + 1];
	char *start, *end, *var;

	while ((start = strstr(new_location, "${")) &&
	       (end = strchr(start + 2, '}'))) {
		*start = *end = 0;
		var = getenv(start + 2);
		snprintf(expanded, sizeof expanded, "%s%s%s",
			 new_location, var ? var : "", end + 1);
		strcpy(new_location, expanded);
	}

	return new_location;
}

static int cpio_mkfile_line(const char *line)
{
	char name[PATH_MAX + 1];
	char *dname = NULL; /* malloc'ed buffer for hard links */
	char location[PATH_MAX + 1];
	unsigned int mode;
	int uid;
	int gid;
	int nlinks = 1;
	int end = 0, dname_len = 0;
	int rc = -1;

	if (5 > sscanf(line, "%" str(PATH_MAX) "s %" str(PATH_MAX)
				"s %o %d %d %n",
				name, location, &mode, &uid, &gid, &end)) {
		fprintf(stderr, "Unrecognized file format '%s'", line);
		goto fail;
	}
	if (end && isgraph(line[end])) {
		int len;
		int nend;

		dname = malloc(strlen(line));
		if (!dname) {
			fprintf (stderr, "out of memory (%d)\n", dname_len);
			goto fail;
		}

		dname_len = strlen(name) + 1;
		memcpy(dname, name, dname_len);

		do {
			nend = 0;
			if (sscanf(line + end, "%" str(PATH_MAX) "s %n",
					name, &nend) < 1)
				break;
			len = strlen(name) + 1;
			memcpy(dname + dname_len, name, len);
			dname_len += len;
			nlinks++;
			end += nend;
		} while (isgraph(line[end]));
	} else {
		dname = name;
	}
	rc = cpio_mkfile(dname, cpio_replace_env(location),
	                 mode, uid, gid, nlinks);
 fail:
	if (dname_len) free(dname);
	return rc;
}

static void usage(const char *prog)
{
	fprintf(stderr, "Usage:\n"
		"\t%s [-t <timestamp>] [-c] <cpio_list>\n"
		"\n"
		"<cpio_list> is a file containing newline separated entries that\n"
		"describe the files to be included in the initramfs archive:\n"
		"\n"
		"# a comment\n"
		"file <name> <location> <mode> <uid> <gid> [<hard links>]\n"
		"dir <name> <mode> <uid> <gid>\n"
		"nod <name> <mode> <uid> <gid> <dev_type> <maj> <min>\n"
		"slink <name> <target> <mode> <uid> <gid>\n"
		"pipe <name> <mode> <uid> <gid>\n"
		"sock <name> <mode> <uid> <gid>\n"
		"\n"
		"<name>       name of the file/dir/nod/etc in the archive\n"
		"<location>   location of the file in the current filesystem\n"
		"             expands shell variables quoted with ${}\n"
		"<target>     link target\n"
		"<mode>       mode/permissions of the file\n"
		"<uid>        user id (0=root)\n"
		"<gid>        group id (0=root)\n"
		"<dev_type>   device type (b=block, c=character)\n"
		"<maj>        major number of nod\n"
		"<min>        minor number of nod\n"
		"<hard links> space separated list of other links to file\n"
		"\n"
		"example:\n"
		"# A simple initramfs\n"
		"dir /dev 0755 0 0\n"
		"nod /dev/console 0600 0 0 c 5 1\n"
		"dir /root 0700 0 0\n"
		"dir /sbin 0755 0 0\n"
		"file /sbin/kinit /usr/src/klibc/kinit/kinit 0755 0 0\n"
		"\n"
		"<timestamp> is time in seconds since Epoch that will be used\n"
		"as mtime for symlinks, special files and directories. The default\n"
		"is to use the current time for these entries.\n"
		"-c: calculate and store 32-bit checksums for file data.\n",
		prog);
}

static const struct file_handler file_handler_table[] = {
	{
		.type    = "file",
		.handler = cpio_mkfile_line,
	}, {
		.type    = "nod",
		.handler = cpio_mknod_line,
	}, {
		.type    = "dir",
		.handler = cpio_mkdir_line,
	}, {
		.type    = "slink",
		.handler = cpio_mkslink_line,
	}, {
		.type    = "pipe",
		.handler = cpio_mkpipe_line,
	}, {
		.type    = "sock",
		.handler = cpio_mksock_line,
	}, {
		.type    = NULL,
		.handler = NULL,
	}
};

#define LINE_SIZE (2 * PATH_MAX + 50)

int main (int argc, char *argv[])
{
	FILE *cpio_list;
	char line[LINE_SIZE];
	char *args, *type;
	int ec = 0;
	int line_nr = 0;
	const char *filename;

	default_mtime = time(NULL);
	while (1) {
		int opt = getopt(argc, argv, "t:ch");
		char *invalid;

		if (opt == -1)
			break;
		switch (opt) {
		case 't':
			default_mtime = strtol(optarg, &invalid, 10);
			if (!*optarg || *invalid) {
				fprintf(stderr, "Invalid timestamp: %s\n",
						optarg);
				usage(argv[0]);
				exit(1);
			}
			break;
		case 'c':
			do_csum = true;
			break;
		case 'h':
		case '?':
			usage(argv[0]);
			exit(opt == 'h' ? 0 : 1);
		}
	}

	/*
	 * Timestamps after 2106-02-07 06:28:15 UTC have an ascii hex time_t
	 * representation that exceeds 8 chars and breaks the cpio header
	 * specification.
	 */
	if (default_mtime > 0xffffffff) {
		fprintf(stderr, "ERROR: Timestamp too large for cpio format\n");
		exit(1);
	}

	if (argc - optind != 1) {
		usage(argv[0]);
		exit(1);
	}
	filename = argv[optind];
	if (!strcmp(filename, "-"))
		cpio_list = stdin;
	else if (!(cpio_list = fopen(filename, "r"))) {
		fprintf(stderr, "ERROR: unable to open '%s': %s\n\n",
			filename, strerror(errno));
		usage(argv[0]);
		exit(1);
	}

	while (fgets(line, LINE_SIZE, cpio_list)) {
		int type_idx;
		size_t slen = strlen(line);

		line_nr++;

		if ('#' == *line) {
			/* comment - skip to next line */
			continue;
		}

		if (! (type = strtok(line, " \t"))) {
			fprintf(stderr,
				"ERROR: incorrect format, could not locate file type line %d: '%s'\n",
				line_nr, line);
			ec = -1;
			break;
		}

		if ('\n' == *type) {
			/* a blank line */
			continue;
		}

		if (slen == strlen(type)) {
			/* must be an empty line */
			continue;
		}

		if (! (args = strtok(NULL, "\n"))) {
			fprintf(stderr,
				"ERROR: incorrect format, newline required line %d: '%s'\n",
				line_nr, line);
			ec = -1;
		}

		for (type_idx = 0; file_handler_table[type_idx].type; type_idx++) {
			int rc;
			if (! strcmp(line, file_handler_table[type_idx].type)) {
				if ((rc = file_handler_table[type_idx].handler(args))) {
					ec = rc;
					fprintf(stderr, " line %d\n", line_nr);
				}
				break;
			}
		}

		if (NULL == file_handler_table[type_idx].type) {
			fprintf(stderr, "unknown file type line %d: '%s'\n",
				line_nr, line);
		}
	}
	if (ec == 0)
		cpio_trailer();

	exit(ec);
}