xref: /openbmc/linux/usr/gen_init_cpio.c (revision 1ab142d4)
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 	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 env_var[PATH_MAX + 1];
386        char *start;
387        char *end;
388 
389        for (start = NULL; (start = strstr(new_location, "${")); ) {
390                end = strchr(start, '}');
391                if (start < end) {
392                        *env_var = *expanded = '\0';
393                        strncat(env_var, start + 2, end - start - 2);
394                        strncat(expanded, new_location, start - new_location);
395                        strncat(expanded, getenv(env_var), PATH_MAX);
396                        strncat(expanded, end + 1, PATH_MAX);
397                        strncpy(new_location, expanded, PATH_MAX);
398                } else
399                        break;
400        }
401 
402        return new_location;
403 }
404 
405 
406 static int cpio_mkfile_line(const char *line)
407 {
408 	char name[PATH_MAX + 1];
409 	char *dname = NULL; /* malloc'ed buffer for hard links */
410 	char location[PATH_MAX + 1];
411 	unsigned int mode;
412 	int uid;
413 	int gid;
414 	int nlinks = 1;
415 	int end = 0, dname_len = 0;
416 	int rc = -1;
417 
418 	if (5 > sscanf(line, "%" str(PATH_MAX) "s %" str(PATH_MAX)
419 				"s %o %d %d %n",
420 				name, location, &mode, &uid, &gid, &end)) {
421 		fprintf(stderr, "Unrecognized file format '%s'", line);
422 		goto fail;
423 	}
424 	if (end && isgraph(line[end])) {
425 		int len;
426 		int nend;
427 
428 		dname = malloc(strlen(line));
429 		if (!dname) {
430 			fprintf (stderr, "out of memory (%d)\n", dname_len);
431 			goto fail;
432 		}
433 
434 		dname_len = strlen(name) + 1;
435 		memcpy(dname, name, dname_len);
436 
437 		do {
438 			nend = 0;
439 			if (sscanf(line + end, "%" str(PATH_MAX) "s %n",
440 					name, &nend) < 1)
441 				break;
442 			len = strlen(name) + 1;
443 			memcpy(dname + dname_len, name, len);
444 			dname_len += len;
445 			nlinks++;
446 			end += nend;
447 		} while (isgraph(line[end]));
448 	} else {
449 		dname = name;
450 	}
451 	rc = cpio_mkfile(dname, cpio_replace_env(location),
452 	                 mode, uid, gid, nlinks);
453  fail:
454 	if (dname_len) free(dname);
455 	return rc;
456 }
457 
458 static void usage(const char *prog)
459 {
460 	fprintf(stderr, "Usage:\n"
461 		"\t%s [-t <timestamp>] <cpio_list>\n"
462 		"\n"
463 		"<cpio_list> is a file containing newline separated entries that\n"
464 		"describe the files to be included in the initramfs archive:\n"
465 		"\n"
466 		"# a comment\n"
467 		"file <name> <location> <mode> <uid> <gid> [<hard links>]\n"
468 		"dir <name> <mode> <uid> <gid>\n"
469 		"nod <name> <mode> <uid> <gid> <dev_type> <maj> <min>\n"
470 		"slink <name> <target> <mode> <uid> <gid>\n"
471 		"pipe <name> <mode> <uid> <gid>\n"
472 		"sock <name> <mode> <uid> <gid>\n"
473 		"\n"
474 		"<name>       name of the file/dir/nod/etc in the archive\n"
475 		"<location>   location of the file in the current filesystem\n"
476 		"             expands shell variables quoted with ${}\n"
477 		"<target>     link target\n"
478 		"<mode>       mode/permissions of the file\n"
479 		"<uid>        user id (0=root)\n"
480 		"<gid>        group id (0=root)\n"
481 		"<dev_type>   device type (b=block, c=character)\n"
482 		"<maj>        major number of nod\n"
483 		"<min>        minor number of nod\n"
484 		"<hard links> space separated list of other links to file\n"
485 		"\n"
486 		"example:\n"
487 		"# A simple initramfs\n"
488 		"dir /dev 0755 0 0\n"
489 		"nod /dev/console 0600 0 0 c 5 1\n"
490 		"dir /root 0700 0 0\n"
491 		"dir /sbin 0755 0 0\n"
492 		"file /sbin/kinit /usr/src/klibc/kinit/kinit 0755 0 0\n"
493 		"\n"
494 		"<timestamp> is time in seconds since Epoch that will be used\n"
495 		"as mtime for symlinks, special files and directories. The default\n"
496 		"is to use the current time for these entries.\n",
497 		prog);
498 }
499 
500 struct file_handler file_handler_table[] = {
501 	{
502 		.type    = "file",
503 		.handler = cpio_mkfile_line,
504 	}, {
505 		.type    = "nod",
506 		.handler = cpio_mknod_line,
507 	}, {
508 		.type    = "dir",
509 		.handler = cpio_mkdir_line,
510 	}, {
511 		.type    = "slink",
512 		.handler = cpio_mkslink_line,
513 	}, {
514 		.type    = "pipe",
515 		.handler = cpio_mkpipe_line,
516 	}, {
517 		.type    = "sock",
518 		.handler = cpio_mksock_line,
519 	}, {
520 		.type    = NULL,
521 		.handler = NULL,
522 	}
523 };
524 
525 #define LINE_SIZE (2 * PATH_MAX + 50)
526 
527 int main (int argc, char *argv[])
528 {
529 	FILE *cpio_list;
530 	char line[LINE_SIZE];
531 	char *args, *type;
532 	int ec = 0;
533 	int line_nr = 0;
534 	const char *filename;
535 
536 	default_mtime = time(NULL);
537 	while (1) {
538 		int opt = getopt(argc, argv, "t:h");
539 		char *invalid;
540 
541 		if (opt == -1)
542 			break;
543 		switch (opt) {
544 		case 't':
545 			default_mtime = strtol(optarg, &invalid, 10);
546 			if (!*optarg || *invalid) {
547 				fprintf(stderr, "Invalid timestamp: %s\n",
548 						optarg);
549 				usage(argv[0]);
550 				exit(1);
551 			}
552 			break;
553 		case 'h':
554 		case '?':
555 			usage(argv[0]);
556 			exit(opt == 'h' ? 0 : 1);
557 		}
558 	}
559 
560 	if (argc - optind != 1) {
561 		usage(argv[0]);
562 		exit(1);
563 	}
564 	filename = argv[optind];
565 	if (!strcmp(filename, "-"))
566 		cpio_list = stdin;
567 	else if (!(cpio_list = fopen(filename, "r"))) {
568 		fprintf(stderr, "ERROR: unable to open '%s': %s\n\n",
569 			filename, strerror(errno));
570 		usage(argv[0]);
571 		exit(1);
572 	}
573 
574 	while (fgets(line, LINE_SIZE, cpio_list)) {
575 		int type_idx;
576 		size_t slen = strlen(line);
577 
578 		line_nr++;
579 
580 		if ('#' == *line) {
581 			/* comment - skip to next line */
582 			continue;
583 		}
584 
585 		if (! (type = strtok(line, " \t"))) {
586 			fprintf(stderr,
587 				"ERROR: incorrect format, could not locate file type line %d: '%s'\n",
588 				line_nr, line);
589 			ec = -1;
590 			break;
591 		}
592 
593 		if ('\n' == *type) {
594 			/* a blank line */
595 			continue;
596 		}
597 
598 		if (slen == strlen(type)) {
599 			/* must be an empty line */
600 			continue;
601 		}
602 
603 		if (! (args = strtok(NULL, "\n"))) {
604 			fprintf(stderr,
605 				"ERROR: incorrect format, newline required line %d: '%s'\n",
606 				line_nr, line);
607 			ec = -1;
608 		}
609 
610 		for (type_idx = 0; file_handler_table[type_idx].type; type_idx++) {
611 			int rc;
612 			if (! strcmp(line, file_handler_table[type_idx].type)) {
613 				if ((rc = file_handler_table[type_idx].handler(args))) {
614 					ec = rc;
615 					fprintf(stderr, " line %d\n", line_nr);
616 				}
617 				break;
618 			}
619 		}
620 
621 		if (NULL == file_handler_table[type_idx].type) {
622 			fprintf(stderr, "unknown file type line %d: '%s'\n",
623 				line_nr, line);
624 		}
625 	}
626 	if (ec == 0)
627 		cpio_trailer();
628 
629 	exit(ec);
630 }
631