xref: /linux/usr/gen_init_cpio.c (revision b6ebbac51bedf9e98e837688bc838f400196da5e)
1 #include <stdio.h>
2 #include <stdlib.h>
3 #include <sys/types.h>
4 #include <sys/stat.h>
5 #include <string.h>
6 #include <unistd.h>
7 #include <time.h>
8 #include <fcntl.h>
9 #include <errno.h>
10 #include <ctype.h>
11 #include <limits.h>
12 
13 /*
14  * Original work by Jeff Garzik
15  *
16  * External file lists, symlink, pipe and fifo support by Thayne Harbaugh
17  * Hard link support by Luciano Rocha
18  */
19 
20 #define xstr(s) #s
21 #define str(s) xstr(s)
22 
23 static unsigned int offset;
24 static unsigned int ino = 721;
25 static time_t default_mtime;
26 
27 struct file_handler {
28 	const char *type;
29 	int (*handler)(const char *line);
30 };
31 
32 static void push_string(const char *name)
33 {
34 	unsigned int name_len = strlen(name) + 1;
35 
36 	fputs(name, stdout);
37 	putchar(0);
38 	offset += name_len;
39 }
40 
41 static void push_pad (void)
42 {
43 	while (offset & 3) {
44 		putchar(0);
45 		offset++;
46 	}
47 }
48 
49 static void push_rest(const char *name)
50 {
51 	unsigned int name_len = strlen(name) + 1;
52 	unsigned int tmp_ofs;
53 
54 	fputs(name, stdout);
55 	putchar(0);
56 	offset += name_len;
57 
58 	tmp_ofs = name_len + 110;
59 	while (tmp_ofs & 3) {
60 		putchar(0);
61 		offset++;
62 		tmp_ofs++;
63 	}
64 }
65 
66 static void push_hdr(const char *s)
67 {
68 	fputs(s, stdout);
69 	offset += 110;
70 }
71 
72 static void cpio_trailer(void)
73 {
74 	char s[256];
75 	const char name[] = "TRAILER!!!";
76 
77 	sprintf(s, "%s%08X%08X%08lX%08lX%08X%08lX"
78 	       "%08X%08X%08X%08X%08X%08X%08X",
79 		"070701",		/* magic */
80 		0,			/* ino */
81 		0,			/* mode */
82 		(long) 0,		/* uid */
83 		(long) 0,		/* gid */
84 		1,			/* nlink */
85 		(long) 0,		/* mtime */
86 		0,			/* filesize */
87 		0,			/* major */
88 		0,			/* minor */
89 		0,			/* rmajor */
90 		0,			/* rminor */
91 		(unsigned)strlen(name)+1, /* namesize */
92 		0);			/* chksum */
93 	push_hdr(s);
94 	push_rest(name);
95 
96 	while (offset % 512) {
97 		putchar(0);
98 		offset++;
99 	}
100 }
101 
102 static int cpio_mkslink(const char *name, const char *target,
103 			 unsigned int mode, uid_t uid, gid_t gid)
104 {
105 	char s[256];
106 
107 	if (name[0] == '/')
108 		name++;
109 	sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
110 	       "%08X%08X%08X%08X%08X%08X%08X",
111 		"070701",		/* magic */
112 		ino++,			/* ino */
113 		S_IFLNK | mode,		/* mode */
114 		(long) uid,		/* uid */
115 		(long) gid,		/* gid */
116 		1,			/* nlink */
117 		(long) default_mtime,	/* mtime */
118 		(unsigned)strlen(target)+1, /* filesize */
119 		3,			/* major */
120 		1,			/* minor */
121 		0,			/* rmajor */
122 		0,			/* rminor */
123 		(unsigned)strlen(name) + 1,/* namesize */
124 		0);			/* chksum */
125 	push_hdr(s);
126 	push_string(name);
127 	push_pad();
128 	push_string(target);
129 	push_pad();
130 	return 0;
131 }
132 
133 static int cpio_mkslink_line(const char *line)
134 {
135 	char name[PATH_MAX + 1];
136 	char target[PATH_MAX + 1];
137 	unsigned int mode;
138 	int uid;
139 	int gid;
140 	int rc = -1;
141 
142 	if (5 != sscanf(line, "%" str(PATH_MAX) "s %" str(PATH_MAX) "s %o %d %d", name, target, &mode, &uid, &gid)) {
143 		fprintf(stderr, "Unrecognized dir format '%s'", line);
144 		goto fail;
145 	}
146 	rc = cpio_mkslink(name, target, mode, uid, gid);
147  fail:
148 	return rc;
149 }
150 
151 static int cpio_mkgeneric(const char *name, unsigned int mode,
152 		       uid_t uid, gid_t gid)
153 {
154 	char s[256];
155 
156 	if (name[0] == '/')
157 		name++;
158 	sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
159 	       "%08X%08X%08X%08X%08X%08X%08X",
160 		"070701",		/* magic */
161 		ino++,			/* ino */
162 		mode,			/* mode */
163 		(long) uid,		/* uid */
164 		(long) gid,		/* gid */
165 		2,			/* nlink */
166 		(long) default_mtime,	/* mtime */
167 		0,			/* filesize */
168 		3,			/* major */
169 		1,			/* minor */
170 		0,			/* rmajor */
171 		0,			/* rminor */
172 		(unsigned)strlen(name) + 1,/* namesize */
173 		0);			/* chksum */
174 	push_hdr(s);
175 	push_rest(name);
176 	return 0;
177 }
178 
179 enum generic_types {
180 	GT_DIR,
181 	GT_PIPE,
182 	GT_SOCK
183 };
184 
185 struct generic_type {
186 	const char *type;
187 	mode_t mode;
188 };
189 
190 static struct generic_type generic_type_table[] = {
191 	[GT_DIR] = {
192 		.type = "dir",
193 		.mode = S_IFDIR
194 	},
195 	[GT_PIPE] = {
196 		.type = "pipe",
197 		.mode = S_IFIFO
198 	},
199 	[GT_SOCK] = {
200 		.type = "sock",
201 		.mode = S_IFSOCK
202 	}
203 };
204 
205 static int cpio_mkgeneric_line(const char *line, enum generic_types gt)
206 {
207 	char name[PATH_MAX + 1];
208 	unsigned int mode;
209 	int uid;
210 	int gid;
211 	int rc = -1;
212 
213 	if (4 != sscanf(line, "%" str(PATH_MAX) "s %o %d %d", name, &mode, &uid, &gid)) {
214 		fprintf(stderr, "Unrecognized %s format '%s'",
215 			line, generic_type_table[gt].type);
216 		goto fail;
217 	}
218 	mode |= generic_type_table[gt].mode;
219 	rc = cpio_mkgeneric(name, mode, uid, gid);
220  fail:
221 	return rc;
222 }
223 
224 static int cpio_mkdir_line(const char *line)
225 {
226 	return cpio_mkgeneric_line(line, GT_DIR);
227 }
228 
229 static int cpio_mkpipe_line(const char *line)
230 {
231 	return cpio_mkgeneric_line(line, GT_PIPE);
232 }
233 
234 static int cpio_mksock_line(const char *line)
235 {
236 	return cpio_mkgeneric_line(line, GT_SOCK);
237 }
238 
239 static int cpio_mknod(const char *name, unsigned int mode,
240 		       uid_t uid, gid_t gid, char dev_type,
241 		       unsigned int maj, unsigned int min)
242 {
243 	char s[256];
244 
245 	if (dev_type == 'b')
246 		mode |= S_IFBLK;
247 	else
248 		mode |= S_IFCHR;
249 
250 	if (name[0] == '/')
251 		name++;
252 	sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
253 	       "%08X%08X%08X%08X%08X%08X%08X",
254 		"070701",		/* magic */
255 		ino++,			/* ino */
256 		mode,			/* mode */
257 		(long) uid,		/* uid */
258 		(long) gid,		/* gid */
259 		1,			/* nlink */
260 		(long) default_mtime,	/* mtime */
261 		0,			/* filesize */
262 		3,			/* major */
263 		1,			/* minor */
264 		maj,			/* rmajor */
265 		min,			/* rminor */
266 		(unsigned)strlen(name) + 1,/* namesize */
267 		0);			/* chksum */
268 	push_hdr(s);
269 	push_rest(name);
270 	return 0;
271 }
272 
273 static int cpio_mknod_line(const char *line)
274 {
275 	char name[PATH_MAX + 1];
276 	unsigned int mode;
277 	int uid;
278 	int gid;
279 	char dev_type;
280 	unsigned int maj;
281 	unsigned int min;
282 	int rc = -1;
283 
284 	if (7 != sscanf(line, "%" str(PATH_MAX) "s %o %d %d %c %u %u",
285 			 name, &mode, &uid, &gid, &dev_type, &maj, &min)) {
286 		fprintf(stderr, "Unrecognized nod format '%s'", line);
287 		goto fail;
288 	}
289 	rc = cpio_mknod(name, mode, uid, gid, dev_type, maj, min);
290  fail:
291 	return rc;
292 }
293 
294 static int cpio_mkfile(const char *name, const char *location,
295 			unsigned int mode, uid_t uid, gid_t gid,
296 			unsigned int nlinks)
297 {
298 	char s[256];
299 	char *filebuf = NULL;
300 	struct stat buf;
301 	long size;
302 	int file = -1;
303 	int retval;
304 	int rc = -1;
305 	int namesize;
306 	unsigned int i;
307 
308 	mode |= S_IFREG;
309 
310 	file = open (location, O_RDONLY);
311 	if (file < 0) {
312 		fprintf (stderr, "File %s could not be opened for reading\n", location);
313 		goto error;
314 	}
315 
316 	retval = fstat(file, &buf);
317 	if (retval) {
318 		fprintf(stderr, "File %s could not be stat()'ed\n", location);
319 		goto error;
320 	}
321 
322 	filebuf = malloc(buf.st_size);
323 	if (!filebuf) {
324 		fprintf (stderr, "out of memory\n");
325 		goto error;
326 	}
327 
328 	retval = read (file, filebuf, buf.st_size);
329 	if (retval < 0) {
330 		fprintf (stderr, "Can not read %s file\n", location);
331 		goto error;
332 	}
333 
334 	size = 0;
335 	for (i = 1; i <= nlinks; i++) {
336 		/* data goes on last link */
337 		if (i == nlinks) size = buf.st_size;
338 
339 		if (name[0] == '/')
340 			name++;
341 		namesize = strlen(name) + 1;
342 		sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
343 		       "%08lX%08X%08X%08X%08X%08X%08X",
344 			"070701",		/* magic */
345 			ino,			/* ino */
346 			mode,			/* mode */
347 			(long) uid,		/* uid */
348 			(long) gid,		/* gid */
349 			nlinks,			/* nlink */
350 			(long) buf.st_mtime,	/* mtime */
351 			size,			/* filesize */
352 			3,			/* major */
353 			1,			/* minor */
354 			0,			/* rmajor */
355 			0,			/* rminor */
356 			namesize,		/* namesize */
357 			0);			/* chksum */
358 		push_hdr(s);
359 		push_string(name);
360 		push_pad();
361 
362 		if (size) {
363 			if (fwrite(filebuf, size, 1, stdout) != 1) {
364 				fprintf(stderr, "writing filebuf failed\n");
365 				goto error;
366 			}
367 			offset += size;
368 			push_pad();
369 		}
370 
371 		name += namesize;
372 	}
373 	ino++;
374 	rc = 0;
375 
376 error:
377 	if (filebuf) free(filebuf);
378 	if (file >= 0) close(file);
379 	return rc;
380 }
381 
382 static char *cpio_replace_env(char *new_location)
383 {
384 	char expanded[PATH_MAX + 1];
385 	char *start, *end, *var;
386 
387 	while ((start = strstr(new_location, "${")) &&
388 	       (end = strchr(start + 2, '}'))) {
389 		*start = *end = 0;
390 		var = getenv(start + 2);
391 		snprintf(expanded, sizeof expanded, "%s%s%s",
392 			 new_location, var ? var : "", end + 1);
393 		strcpy(new_location, expanded);
394 	}
395 
396 	return new_location;
397 }
398 
399 static int cpio_mkfile_line(const char *line)
400 {
401 	char name[PATH_MAX + 1];
402 	char *dname = NULL; /* malloc'ed buffer for hard links */
403 	char location[PATH_MAX + 1];
404 	unsigned int mode;
405 	int uid;
406 	int gid;
407 	int nlinks = 1;
408 	int end = 0, dname_len = 0;
409 	int rc = -1;
410 
411 	if (5 > sscanf(line, "%" str(PATH_MAX) "s %" str(PATH_MAX)
412 				"s %o %d %d %n",
413 				name, location, &mode, &uid, &gid, &end)) {
414 		fprintf(stderr, "Unrecognized file format '%s'", line);
415 		goto fail;
416 	}
417 	if (end && isgraph(line[end])) {
418 		int len;
419 		int nend;
420 
421 		dname = malloc(strlen(line));
422 		if (!dname) {
423 			fprintf (stderr, "out of memory (%d)\n", dname_len);
424 			goto fail;
425 		}
426 
427 		dname_len = strlen(name) + 1;
428 		memcpy(dname, name, dname_len);
429 
430 		do {
431 			nend = 0;
432 			if (sscanf(line + end, "%" str(PATH_MAX) "s %n",
433 					name, &nend) < 1)
434 				break;
435 			len = strlen(name) + 1;
436 			memcpy(dname + dname_len, name, len);
437 			dname_len += len;
438 			nlinks++;
439 			end += nend;
440 		} while (isgraph(line[end]));
441 	} else {
442 		dname = name;
443 	}
444 	rc = cpio_mkfile(dname, cpio_replace_env(location),
445 	                 mode, uid, gid, nlinks);
446  fail:
447 	if (dname_len) free(dname);
448 	return rc;
449 }
450 
451 static void usage(const char *prog)
452 {
453 	fprintf(stderr, "Usage:\n"
454 		"\t%s [-t <timestamp>] <cpio_list>\n"
455 		"\n"
456 		"<cpio_list> is a file containing newline separated entries that\n"
457 		"describe the files to be included in the initramfs archive:\n"
458 		"\n"
459 		"# a comment\n"
460 		"file <name> <location> <mode> <uid> <gid> [<hard links>]\n"
461 		"dir <name> <mode> <uid> <gid>\n"
462 		"nod <name> <mode> <uid> <gid> <dev_type> <maj> <min>\n"
463 		"slink <name> <target> <mode> <uid> <gid>\n"
464 		"pipe <name> <mode> <uid> <gid>\n"
465 		"sock <name> <mode> <uid> <gid>\n"
466 		"\n"
467 		"<name>       name of the file/dir/nod/etc in the archive\n"
468 		"<location>   location of the file in the current filesystem\n"
469 		"             expands shell variables quoted with ${}\n"
470 		"<target>     link target\n"
471 		"<mode>       mode/permissions of the file\n"
472 		"<uid>        user id (0=root)\n"
473 		"<gid>        group id (0=root)\n"
474 		"<dev_type>   device type (b=block, c=character)\n"
475 		"<maj>        major number of nod\n"
476 		"<min>        minor number of nod\n"
477 		"<hard links> space separated list of other links to file\n"
478 		"\n"
479 		"example:\n"
480 		"# A simple initramfs\n"
481 		"dir /dev 0755 0 0\n"
482 		"nod /dev/console 0600 0 0 c 5 1\n"
483 		"dir /root 0700 0 0\n"
484 		"dir /sbin 0755 0 0\n"
485 		"file /sbin/kinit /usr/src/klibc/kinit/kinit 0755 0 0\n"
486 		"\n"
487 		"<timestamp> is time in seconds since Epoch that will be used\n"
488 		"as mtime for symlinks, special files and directories. The default\n"
489 		"is to use the current time for these entries.\n",
490 		prog);
491 }
492 
493 struct file_handler file_handler_table[] = {
494 	{
495 		.type    = "file",
496 		.handler = cpio_mkfile_line,
497 	}, {
498 		.type    = "nod",
499 		.handler = cpio_mknod_line,
500 	}, {
501 		.type    = "dir",
502 		.handler = cpio_mkdir_line,
503 	}, {
504 		.type    = "slink",
505 		.handler = cpio_mkslink_line,
506 	}, {
507 		.type    = "pipe",
508 		.handler = cpio_mkpipe_line,
509 	}, {
510 		.type    = "sock",
511 		.handler = cpio_mksock_line,
512 	}, {
513 		.type    = NULL,
514 		.handler = NULL,
515 	}
516 };
517 
518 #define LINE_SIZE (2 * PATH_MAX + 50)
519 
520 int main (int argc, char *argv[])
521 {
522 	FILE *cpio_list;
523 	char line[LINE_SIZE];
524 	char *args, *type;
525 	int ec = 0;
526 	int line_nr = 0;
527 	const char *filename;
528 
529 	default_mtime = time(NULL);
530 	while (1) {
531 		int opt = getopt(argc, argv, "t:h");
532 		char *invalid;
533 
534 		if (opt == -1)
535 			break;
536 		switch (opt) {
537 		case 't':
538 			default_mtime = strtol(optarg, &invalid, 10);
539 			if (!*optarg || *invalid) {
540 				fprintf(stderr, "Invalid timestamp: %s\n",
541 						optarg);
542 				usage(argv[0]);
543 				exit(1);
544 			}
545 			break;
546 		case 'h':
547 		case '?':
548 			usage(argv[0]);
549 			exit(opt == 'h' ? 0 : 1);
550 		}
551 	}
552 
553 	if (argc - optind != 1) {
554 		usage(argv[0]);
555 		exit(1);
556 	}
557 	filename = argv[optind];
558 	if (!strcmp(filename, "-"))
559 		cpio_list = stdin;
560 	else if (!(cpio_list = fopen(filename, "r"))) {
561 		fprintf(stderr, "ERROR: unable to open '%s': %s\n\n",
562 			filename, strerror(errno));
563 		usage(argv[0]);
564 		exit(1);
565 	}
566 
567 	while (fgets(line, LINE_SIZE, cpio_list)) {
568 		int type_idx;
569 		size_t slen = strlen(line);
570 
571 		line_nr++;
572 
573 		if ('#' == *line) {
574 			/* comment - skip to next line */
575 			continue;
576 		}
577 
578 		if (! (type = strtok(line, " \t"))) {
579 			fprintf(stderr,
580 				"ERROR: incorrect format, could not locate file type line %d: '%s'\n",
581 				line_nr, line);
582 			ec = -1;
583 			break;
584 		}
585 
586 		if ('\n' == *type) {
587 			/* a blank line */
588 			continue;
589 		}
590 
591 		if (slen == strlen(type)) {
592 			/* must be an empty line */
593 			continue;
594 		}
595 
596 		if (! (args = strtok(NULL, "\n"))) {
597 			fprintf(stderr,
598 				"ERROR: incorrect format, newline required line %d: '%s'\n",
599 				line_nr, line);
600 			ec = -1;
601 		}
602 
603 		for (type_idx = 0; file_handler_table[type_idx].type; type_idx++) {
604 			int rc;
605 			if (! strcmp(line, file_handler_table[type_idx].type)) {
606 				if ((rc = file_handler_table[type_idx].handler(args))) {
607 					ec = rc;
608 					fprintf(stderr, " line %d\n", line_nr);
609 				}
610 				break;
611 			}
612 		}
613 
614 		if (NULL == file_handler_table[type_idx].type) {
615 			fprintf(stderr, "unknown file type line %d: '%s'\n",
616 				line_nr, line);
617 		}
618 	}
619 	if (ec == 0)
620 		cpio_trailer();
621 
622 	exit(ec);
623 }
624