xref: /linux/usr/gen_init_cpio.c (revision d524dac9279b6a41ffdf7ff7958c577f2e387db6)
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 
26 struct file_handler {
27 	const char *type;
28 	int (*handler)(const char *line);
29 };
30 
31 static void push_string(const char *name)
32 {
33 	unsigned int name_len = strlen(name) + 1;
34 
35 	fputs(name, stdout);
36 	putchar(0);
37 	offset += name_len;
38 }
39 
40 static void push_pad (void)
41 {
42 	while (offset & 3) {
43 		putchar(0);
44 		offset++;
45 	}
46 }
47 
48 static void push_rest(const char *name)
49 {
50 	unsigned int name_len = strlen(name) + 1;
51 	unsigned int tmp_ofs;
52 
53 	fputs(name, stdout);
54 	putchar(0);
55 	offset += name_len;
56 
57 	tmp_ofs = name_len + 110;
58 	while (tmp_ofs & 3) {
59 		putchar(0);
60 		offset++;
61 		tmp_ofs++;
62 	}
63 }
64 
65 static void push_hdr(const char *s)
66 {
67 	fputs(s, stdout);
68 	offset += 110;
69 }
70 
71 static void cpio_trailer(void)
72 {
73 	char s[256];
74 	const char name[] = "TRAILER!!!";
75 
76 	sprintf(s, "%s%08X%08X%08lX%08lX%08X%08lX"
77 	       "%08X%08X%08X%08X%08X%08X%08X",
78 		"070701",		/* magic */
79 		0,			/* ino */
80 		0,			/* mode */
81 		(long) 0,		/* uid */
82 		(long) 0,		/* gid */
83 		1,			/* nlink */
84 		(long) 0,		/* mtime */
85 		0,			/* filesize */
86 		0,			/* major */
87 		0,			/* minor */
88 		0,			/* rmajor */
89 		0,			/* rminor */
90 		(unsigned)strlen(name)+1, /* namesize */
91 		0);			/* chksum */
92 	push_hdr(s);
93 	push_rest(name);
94 
95 	while (offset % 512) {
96 		putchar(0);
97 		offset++;
98 	}
99 }
100 
101 static int cpio_mkslink(const char *name, const char *target,
102 			 unsigned int mode, uid_t uid, gid_t gid)
103 {
104 	char s[256];
105 	time_t mtime = time(NULL);
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) 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 	time_t mtime = time(NULL);
156 
157 	if (name[0] == '/')
158 		name++;
159 	sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
160 	       "%08X%08X%08X%08X%08X%08X%08X",
161 		"070701",		/* magic */
162 		ino++,			/* ino */
163 		mode,			/* mode */
164 		(long) uid,		/* uid */
165 		(long) gid,		/* gid */
166 		2,			/* nlink */
167 		(long) mtime,		/* mtime */
168 		0,			/* filesize */
169 		3,			/* major */
170 		1,			/* minor */
171 		0,			/* rmajor */
172 		0,			/* rminor */
173 		(unsigned)strlen(name) + 1,/* namesize */
174 		0);			/* chksum */
175 	push_hdr(s);
176 	push_rest(name);
177 	return 0;
178 }
179 
180 enum generic_types {
181 	GT_DIR,
182 	GT_PIPE,
183 	GT_SOCK
184 };
185 
186 struct generic_type {
187 	const char *type;
188 	mode_t mode;
189 };
190 
191 static struct generic_type generic_type_table[] = {
192 	[GT_DIR] = {
193 		.type = "dir",
194 		.mode = S_IFDIR
195 	},
196 	[GT_PIPE] = {
197 		.type = "pipe",
198 		.mode = S_IFIFO
199 	},
200 	[GT_SOCK] = {
201 		.type = "sock",
202 		.mode = S_IFSOCK
203 	}
204 };
205 
206 static int cpio_mkgeneric_line(const char *line, enum generic_types gt)
207 {
208 	char name[PATH_MAX + 1];
209 	unsigned int mode;
210 	int uid;
211 	int gid;
212 	int rc = -1;
213 
214 	if (4 != sscanf(line, "%" str(PATH_MAX) "s %o %d %d", name, &mode, &uid, &gid)) {
215 		fprintf(stderr, "Unrecognized %s format '%s'",
216 			line, generic_type_table[gt].type);
217 		goto fail;
218 	}
219 	mode |= generic_type_table[gt].mode;
220 	rc = cpio_mkgeneric(name, mode, uid, gid);
221  fail:
222 	return rc;
223 }
224 
225 static int cpio_mkdir_line(const char *line)
226 {
227 	return cpio_mkgeneric_line(line, GT_DIR);
228 }
229 
230 static int cpio_mkpipe_line(const char *line)
231 {
232 	return cpio_mkgeneric_line(line, GT_PIPE);
233 }
234 
235 static int cpio_mksock_line(const char *line)
236 {
237 	return cpio_mkgeneric_line(line, GT_SOCK);
238 }
239 
240 static int cpio_mknod(const char *name, unsigned int mode,
241 		       uid_t uid, gid_t gid, char dev_type,
242 		       unsigned int maj, unsigned int min)
243 {
244 	char s[256];
245 	time_t mtime = time(NULL);
246 
247 	if (dev_type == 'b')
248 		mode |= S_IFBLK;
249 	else
250 		mode |= S_IFCHR;
251 
252 	if (name[0] == '/')
253 		name++;
254 	sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
255 	       "%08X%08X%08X%08X%08X%08X%08X",
256 		"070701",		/* magic */
257 		ino++,			/* ino */
258 		mode,			/* mode */
259 		(long) uid,		/* uid */
260 		(long) gid,		/* gid */
261 		1,			/* nlink */
262 		(long) mtime,		/* mtime */
263 		0,			/* filesize */
264 		3,			/* major */
265 		1,			/* minor */
266 		maj,			/* rmajor */
267 		min,			/* rminor */
268 		(unsigned)strlen(name) + 1,/* namesize */
269 		0);			/* chksum */
270 	push_hdr(s);
271 	push_rest(name);
272 	return 0;
273 }
274 
275 static int cpio_mknod_line(const char *line)
276 {
277 	char name[PATH_MAX + 1];
278 	unsigned int mode;
279 	int uid;
280 	int gid;
281 	char dev_type;
282 	unsigned int maj;
283 	unsigned int min;
284 	int rc = -1;
285 
286 	if (7 != sscanf(line, "%" str(PATH_MAX) "s %o %d %d %c %u %u",
287 			 name, &mode, &uid, &gid, &dev_type, &maj, &min)) {
288 		fprintf(stderr, "Unrecognized nod format '%s'", line);
289 		goto fail;
290 	}
291 	rc = cpio_mknod(name, mode, uid, gid, dev_type, maj, min);
292  fail:
293 	return rc;
294 }
295 
296 static int cpio_mkfile(const char *name, const char *location,
297 			unsigned int mode, uid_t uid, gid_t gid,
298 			unsigned int nlinks)
299 {
300 	char s[256];
301 	char *filebuf = NULL;
302 	struct stat buf;
303 	long size;
304 	int file = -1;
305 	int retval;
306 	int rc = -1;
307 	int namesize;
308 	int i;
309 
310 	mode |= S_IFREG;
311 
312 	file = open (location, O_RDONLY);
313 	if (file < 0) {
314 		fprintf (stderr, "File %s could not be opened for reading\n", location);
315 		goto error;
316 	}
317 
318 	retval = fstat(file, &buf);
319 	if (retval) {
320 		fprintf(stderr, "File %s could not be stat()'ed\n", location);
321 		goto error;
322 	}
323 
324 	filebuf = malloc(buf.st_size);
325 	if (!filebuf) {
326 		fprintf (stderr, "out of memory\n");
327 		goto error;
328 	}
329 
330 	retval = read (file, filebuf, buf.st_size);
331 	if (retval < 0) {
332 		fprintf (stderr, "Can not read %s file\n", location);
333 		goto error;
334 	}
335 
336 	size = 0;
337 	for (i = 1; i <= nlinks; i++) {
338 		/* data goes on last link */
339 		if (i == nlinks) size = buf.st_size;
340 
341 		if (name[0] == '/')
342 			name++;
343 		namesize = strlen(name) + 1;
344 		sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
345 		       "%08lX%08X%08X%08X%08X%08X%08X",
346 			"070701",		/* magic */
347 			ino,			/* ino */
348 			mode,			/* mode */
349 			(long) uid,		/* uid */
350 			(long) gid,		/* gid */
351 			nlinks,			/* nlink */
352 			(long) buf.st_mtime,	/* mtime */
353 			size,			/* filesize */
354 			3,			/* major */
355 			1,			/* minor */
356 			0,			/* rmajor */
357 			0,			/* rminor */
358 			namesize,		/* namesize */
359 			0);			/* chksum */
360 		push_hdr(s);
361 		push_string(name);
362 		push_pad();
363 
364 		if (size) {
365 			if (fwrite(filebuf, size, 1, stdout) != 1) {
366 				fprintf(stderr, "writing filebuf failed\n");
367 				goto error;
368 			}
369 			offset += size;
370 			push_pad();
371 		}
372 
373 		name += namesize;
374 	}
375 	ino++;
376 	rc = 0;
377 
378 error:
379 	if (filebuf) free(filebuf);
380 	if (file >= 0) close(file);
381 	return rc;
382 }
383 
384 static char *cpio_replace_env(char *new_location)
385 {
386        char expanded[PATH_MAX + 1];
387        char env_var[PATH_MAX + 1];
388        char *start;
389        char *end;
390 
391        for (start = NULL; (start = strstr(new_location, "${")); ) {
392                end = strchr(start, '}');
393                if (start < end) {
394                        *env_var = *expanded = '\0';
395                        strncat(env_var, start + 2, end - start - 2);
396                        strncat(expanded, new_location, start - new_location);
397                        strncat(expanded, getenv(env_var), PATH_MAX);
398                        strncat(expanded, end + 1, PATH_MAX);
399                        strncpy(new_location, expanded, PATH_MAX);
400                } else
401                        break;
402        }
403 
404        return new_location;
405 }
406 
407 
408 static int cpio_mkfile_line(const char *line)
409 {
410 	char name[PATH_MAX + 1];
411 	char *dname = NULL; /* malloc'ed buffer for hard links */
412 	char location[PATH_MAX + 1];
413 	unsigned int mode;
414 	int uid;
415 	int gid;
416 	int nlinks = 1;
417 	int end = 0, dname_len = 0;
418 	int rc = -1;
419 
420 	if (5 > sscanf(line, "%" str(PATH_MAX) "s %" str(PATH_MAX)
421 				"s %o %d %d %n",
422 				name, location, &mode, &uid, &gid, &end)) {
423 		fprintf(stderr, "Unrecognized file format '%s'", line);
424 		goto fail;
425 	}
426 	if (end && isgraph(line[end])) {
427 		int len;
428 		int nend;
429 
430 		dname = malloc(strlen(line));
431 		if (!dname) {
432 			fprintf (stderr, "out of memory (%d)\n", dname_len);
433 			goto fail;
434 		}
435 
436 		dname_len = strlen(name) + 1;
437 		memcpy(dname, name, dname_len);
438 
439 		do {
440 			nend = 0;
441 			if (sscanf(line + end, "%" str(PATH_MAX) "s %n",
442 					name, &nend) < 1)
443 				break;
444 			len = strlen(name) + 1;
445 			memcpy(dname + dname_len, name, len);
446 			dname_len += len;
447 			nlinks++;
448 			end += nend;
449 		} while (isgraph(line[end]));
450 	} else {
451 		dname = name;
452 	}
453 	rc = cpio_mkfile(dname, cpio_replace_env(location),
454 	                 mode, uid, gid, nlinks);
455  fail:
456 	if (dname_len) free(dname);
457 	return rc;
458 }
459 
460 static void usage(const char *prog)
461 {
462 	fprintf(stderr, "Usage:\n"
463 		"\t%s <cpio_list>\n"
464 		"\n"
465 		"<cpio_list> is a file containing newline separated entries that\n"
466 		"describe the files to be included in the initramfs archive:\n"
467 		"\n"
468 		"# a comment\n"
469 		"file <name> <location> <mode> <uid> <gid> [<hard links>]\n"
470 		"dir <name> <mode> <uid> <gid>\n"
471 		"nod <name> <mode> <uid> <gid> <dev_type> <maj> <min>\n"
472 		"slink <name> <target> <mode> <uid> <gid>\n"
473 		"pipe <name> <mode> <uid> <gid>\n"
474 		"sock <name> <mode> <uid> <gid>\n"
475 		"\n"
476 		"<name>       name of the file/dir/nod/etc in the archive\n"
477 		"<location>   location of the file in the current filesystem\n"
478 		"             expands shell variables quoted with ${}\n"
479 		"<target>     link target\n"
480 		"<mode>       mode/permissions of the file\n"
481 		"<uid>        user id (0=root)\n"
482 		"<gid>        group id (0=root)\n"
483 		"<dev_type>   device type (b=block, c=character)\n"
484 		"<maj>        major number of nod\n"
485 		"<min>        minor number of nod\n"
486 		"<hard links> space separated list of other links to file\n"
487 		"\n"
488 		"example:\n"
489 		"# A simple initramfs\n"
490 		"dir /dev 0755 0 0\n"
491 		"nod /dev/console 0600 0 0 c 5 1\n"
492 		"dir /root 0700 0 0\n"
493 		"dir /sbin 0755 0 0\n"
494 		"file /sbin/kinit /usr/src/klibc/kinit/kinit 0755 0 0\n",
495 		prog);
496 }
497 
498 struct file_handler file_handler_table[] = {
499 	{
500 		.type    = "file",
501 		.handler = cpio_mkfile_line,
502 	}, {
503 		.type    = "nod",
504 		.handler = cpio_mknod_line,
505 	}, {
506 		.type    = "dir",
507 		.handler = cpio_mkdir_line,
508 	}, {
509 		.type    = "slink",
510 		.handler = cpio_mkslink_line,
511 	}, {
512 		.type    = "pipe",
513 		.handler = cpio_mkpipe_line,
514 	}, {
515 		.type    = "sock",
516 		.handler = cpio_mksock_line,
517 	}, {
518 		.type    = NULL,
519 		.handler = NULL,
520 	}
521 };
522 
523 #define LINE_SIZE (2 * PATH_MAX + 50)
524 
525 int main (int argc, char *argv[])
526 {
527 	FILE *cpio_list;
528 	char line[LINE_SIZE];
529 	char *args, *type;
530 	int ec = 0;
531 	int line_nr = 0;
532 
533 	if (2 != argc) {
534 		usage(argv[0]);
535 		exit(1);
536 	}
537 
538 	if (!strcmp(argv[1], "-"))
539 		cpio_list = stdin;
540 	else if (! (cpio_list = fopen(argv[1], "r"))) {
541 		fprintf(stderr, "ERROR: unable to open '%s': %s\n\n",
542 			argv[1], strerror(errno));
543 		usage(argv[0]);
544 		exit(1);
545 	}
546 
547 	while (fgets(line, LINE_SIZE, cpio_list)) {
548 		int type_idx;
549 		size_t slen = strlen(line);
550 
551 		line_nr++;
552 
553 		if ('#' == *line) {
554 			/* comment - skip to next line */
555 			continue;
556 		}
557 
558 		if (! (type = strtok(line, " \t"))) {
559 			fprintf(stderr,
560 				"ERROR: incorrect format, could not locate file type line %d: '%s'\n",
561 				line_nr, line);
562 			ec = -1;
563 			break;
564 		}
565 
566 		if ('\n' == *type) {
567 			/* a blank line */
568 			continue;
569 		}
570 
571 		if (slen == strlen(type)) {
572 			/* must be an empty line */
573 			continue;
574 		}
575 
576 		if (! (args = strtok(NULL, "\n"))) {
577 			fprintf(stderr,
578 				"ERROR: incorrect format, newline required line %d: '%s'\n",
579 				line_nr, line);
580 			ec = -1;
581 		}
582 
583 		for (type_idx = 0; file_handler_table[type_idx].type; type_idx++) {
584 			int rc;
585 			if (! strcmp(line, file_handler_table[type_idx].type)) {
586 				if ((rc = file_handler_table[type_idx].handler(args))) {
587 					ec = rc;
588 					fprintf(stderr, " line %d\n", line_nr);
589 				}
590 				break;
591 			}
592 		}
593 
594 		if (NULL == file_handler_table[type_idx].type) {
595 			fprintf(stderr, "unknown file type line %d: '%s'\n",
596 				line_nr, line);
597 		}
598 	}
599 	if (ec == 0)
600 		cpio_trailer();
601 
602 	exit(ec);
603 }
604