1 // SPDX-License-Identifier: GPL-2.0
2 #include <stdio.h>
3 #include <stdlib.h>
4 #include <stdint.h>
5 #include <stdbool.h>
6 #include <sys/types.h>
7 #include <sys/stat.h>
8 #include <string.h>
9 #include <unistd.h>
10 #include <time.h>
11 #include <fcntl.h>
12 #include <errno.h>
13 #include <ctype.h>
14 #include <limits.h>
15 
16 /*
17  * Original work by Jeff Garzik
18  *
19  * External file lists, symlink, pipe and fifo support by Thayne Harbaugh
20  * Hard link support by Luciano Rocha
21  */
22 
23 #define xstr(s) #s
24 #define str(s) xstr(s)
25 #define MIN(a, b) ((a) < (b) ? (a) : (b))
26 
27 static unsigned int offset;
28 static unsigned int ino = 721;
29 static time_t default_mtime;
30 static bool do_csum = false;
31 
32 struct file_handler {
33 	const char *type;
34 	int (*handler)(const char *line);
35 };
36 
push_string(const char * name)37 static void push_string(const char *name)
38 {
39 	unsigned int name_len = strlen(name) + 1;
40 
41 	fputs(name, stdout);
42 	putchar(0);
43 	offset += name_len;
44 }
45 
push_pad(void)46 static void push_pad (void)
47 {
48 	while (offset & 3) {
49 		putchar(0);
50 		offset++;
51 	}
52 }
53 
push_rest(const char * name)54 static void push_rest(const char *name)
55 {
56 	unsigned int name_len = strlen(name) + 1;
57 	unsigned int tmp_ofs;
58 
59 	fputs(name, stdout);
60 	putchar(0);
61 	offset += name_len;
62 
63 	tmp_ofs = name_len + 110;
64 	while (tmp_ofs & 3) {
65 		putchar(0);
66 		offset++;
67 		tmp_ofs++;
68 	}
69 }
70 
push_hdr(const char * s)71 static void push_hdr(const char *s)
72 {
73 	fputs(s, stdout);
74 	offset += 110;
75 }
76 
cpio_trailer(void)77 static void cpio_trailer(void)
78 {
79 	char s[256];
80 	const char name[] = "TRAILER!!!";
81 
82 	sprintf(s, "%s%08X%08X%08lX%08lX%08X%08lX"
83 	       "%08X%08X%08X%08X%08X%08X%08X",
84 		do_csum ? "070702" : "070701", /* magic */
85 		0,			/* ino */
86 		0,			/* mode */
87 		(long) 0,		/* uid */
88 		(long) 0,		/* gid */
89 		1,			/* nlink */
90 		(long) 0,		/* mtime */
91 		0,			/* filesize */
92 		0,			/* major */
93 		0,			/* minor */
94 		0,			/* rmajor */
95 		0,			/* rminor */
96 		(unsigned)strlen(name)+1, /* namesize */
97 		0);			/* chksum */
98 	push_hdr(s);
99 	push_rest(name);
100 
101 	while (offset % 512) {
102 		putchar(0);
103 		offset++;
104 	}
105 }
106 
cpio_mkslink(const char * name,const char * target,unsigned int mode,uid_t uid,gid_t gid)107 static int cpio_mkslink(const char *name, const char *target,
108 			 unsigned int mode, uid_t uid, gid_t gid)
109 {
110 	char s[256];
111 
112 	if (name[0] == '/')
113 		name++;
114 	sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
115 	       "%08X%08X%08X%08X%08X%08X%08X",
116 		do_csum ? "070702" : "070701", /* magic */
117 		ino++,			/* ino */
118 		S_IFLNK | mode,		/* mode */
119 		(long) uid,		/* uid */
120 		(long) gid,		/* gid */
121 		1,			/* nlink */
122 		(long) default_mtime,	/* mtime */
123 		(unsigned)strlen(target)+1, /* filesize */
124 		3,			/* major */
125 		1,			/* minor */
126 		0,			/* rmajor */
127 		0,			/* rminor */
128 		(unsigned)strlen(name) + 1,/* namesize */
129 		0);			/* chksum */
130 	push_hdr(s);
131 	push_string(name);
132 	push_pad();
133 	push_string(target);
134 	push_pad();
135 	return 0;
136 }
137 
cpio_mkslink_line(const char * line)138 static int cpio_mkslink_line(const char *line)
139 {
140 	char name[PATH_MAX + 1];
141 	char target[PATH_MAX + 1];
142 	unsigned int mode;
143 	int uid;
144 	int gid;
145 	int rc = -1;
146 
147 	if (5 != sscanf(line, "%" str(PATH_MAX) "s %" str(PATH_MAX) "s %o %d %d", name, target, &mode, &uid, &gid)) {
148 		fprintf(stderr, "Unrecognized dir format '%s'", line);
149 		goto fail;
150 	}
151 	rc = cpio_mkslink(name, target, mode, uid, gid);
152  fail:
153 	return rc;
154 }
155 
cpio_mkgeneric(const char * name,unsigned int mode,uid_t uid,gid_t gid)156 static int cpio_mkgeneric(const char *name, unsigned int mode,
157 		       uid_t uid, gid_t gid)
158 {
159 	char s[256];
160 
161 	if (name[0] == '/')
162 		name++;
163 	sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
164 	       "%08X%08X%08X%08X%08X%08X%08X",
165 		do_csum ? "070702" : "070701", /* magic */
166 		ino++,			/* ino */
167 		mode,			/* mode */
168 		(long) uid,		/* uid */
169 		(long) gid,		/* gid */
170 		2,			/* nlink */
171 		(long) default_mtime,	/* mtime */
172 		0,			/* filesize */
173 		3,			/* major */
174 		1,			/* minor */
175 		0,			/* rmajor */
176 		0,			/* rminor */
177 		(unsigned)strlen(name) + 1,/* namesize */
178 		0);			/* chksum */
179 	push_hdr(s);
180 	push_rest(name);
181 	return 0;
182 }
183 
184 enum generic_types {
185 	GT_DIR,
186 	GT_PIPE,
187 	GT_SOCK
188 };
189 
190 struct generic_type {
191 	const char *type;
192 	mode_t mode;
193 };
194 
195 static const struct generic_type generic_type_table[] = {
196 	[GT_DIR] = {
197 		.type = "dir",
198 		.mode = S_IFDIR
199 	},
200 	[GT_PIPE] = {
201 		.type = "pipe",
202 		.mode = S_IFIFO
203 	},
204 	[GT_SOCK] = {
205 		.type = "sock",
206 		.mode = S_IFSOCK
207 	}
208 };
209 
cpio_mkgeneric_line(const char * line,enum generic_types gt)210 static int cpio_mkgeneric_line(const char *line, enum generic_types gt)
211 {
212 	char name[PATH_MAX + 1];
213 	unsigned int mode;
214 	int uid;
215 	int gid;
216 	int rc = -1;
217 
218 	if (4 != sscanf(line, "%" str(PATH_MAX) "s %o %d %d", name, &mode, &uid, &gid)) {
219 		fprintf(stderr, "Unrecognized %s format '%s'",
220 			line, generic_type_table[gt].type);
221 		goto fail;
222 	}
223 	mode |= generic_type_table[gt].mode;
224 	rc = cpio_mkgeneric(name, mode, uid, gid);
225  fail:
226 	return rc;
227 }
228 
cpio_mkdir_line(const char * line)229 static int cpio_mkdir_line(const char *line)
230 {
231 	return cpio_mkgeneric_line(line, GT_DIR);
232 }
233 
cpio_mkpipe_line(const char * line)234 static int cpio_mkpipe_line(const char *line)
235 {
236 	return cpio_mkgeneric_line(line, GT_PIPE);
237 }
238 
cpio_mksock_line(const char * line)239 static int cpio_mksock_line(const char *line)
240 {
241 	return cpio_mkgeneric_line(line, GT_SOCK);
242 }
243 
cpio_mknod(const char * name,unsigned int mode,uid_t uid,gid_t gid,char dev_type,unsigned int maj,unsigned int min)244 static int cpio_mknod(const char *name, unsigned int mode,
245 		       uid_t uid, gid_t gid, char dev_type,
246 		       unsigned int maj, unsigned int min)
247 {
248 	char s[256];
249 
250 	if (dev_type == 'b')
251 		mode |= S_IFBLK;
252 	else
253 		mode |= S_IFCHR;
254 
255 	if (name[0] == '/')
256 		name++;
257 	sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
258 	       "%08X%08X%08X%08X%08X%08X%08X",
259 		do_csum ? "070702" : "070701", /* magic */
260 		ino++,			/* ino */
261 		mode,			/* mode */
262 		(long) uid,		/* uid */
263 		(long) gid,		/* gid */
264 		1,			/* nlink */
265 		(long) default_mtime,	/* mtime */
266 		0,			/* filesize */
267 		3,			/* major */
268 		1,			/* minor */
269 		maj,			/* rmajor */
270 		min,			/* rminor */
271 		(unsigned)strlen(name) + 1,/* namesize */
272 		0);			/* chksum */
273 	push_hdr(s);
274 	push_rest(name);
275 	return 0;
276 }
277 
cpio_mknod_line(const char * line)278 static int cpio_mknod_line(const char *line)
279 {
280 	char name[PATH_MAX + 1];
281 	unsigned int mode;
282 	int uid;
283 	int gid;
284 	char dev_type;
285 	unsigned int maj;
286 	unsigned int min;
287 	int rc = -1;
288 
289 	if (7 != sscanf(line, "%" str(PATH_MAX) "s %o %d %d %c %u %u",
290 			 name, &mode, &uid, &gid, &dev_type, &maj, &min)) {
291 		fprintf(stderr, "Unrecognized nod format '%s'", line);
292 		goto fail;
293 	}
294 	rc = cpio_mknod(name, mode, uid, gid, dev_type, maj, min);
295  fail:
296 	return rc;
297 }
298 
cpio_mkfile_csum(int fd,unsigned long size,uint32_t * csum)299 static int cpio_mkfile_csum(int fd, unsigned long size, uint32_t *csum)
300 {
301 	while (size) {
302 		unsigned char filebuf[65536];
303 		ssize_t this_read;
304 		size_t i, this_size = MIN(size, sizeof(filebuf));
305 
306 		this_read = read(fd, filebuf, this_size);
307 		if (this_read <= 0 || this_read > this_size)
308 			return -1;
309 
310 		for (i = 0; i < this_read; i++)
311 			*csum += filebuf[i];
312 
313 		size -= this_read;
314 	}
315 	/* seek back to the start for data segment I/O */
316 	if (lseek(fd, 0, SEEK_SET) < 0)
317 		return -1;
318 
319 	return 0;
320 }
321 
cpio_mkfile(const char * name,const char * location,unsigned int mode,uid_t uid,gid_t gid,unsigned int nlinks)322 static int cpio_mkfile(const char *name, const char *location,
323 			unsigned int mode, uid_t uid, gid_t gid,
324 			unsigned int nlinks)
325 {
326 	char s[256];
327 	struct stat buf;
328 	unsigned long size;
329 	int file;
330 	int retval;
331 	int rc = -1;
332 	int namesize;
333 	unsigned int i;
334 	uint32_t csum = 0;
335 
336 	mode |= S_IFREG;
337 
338 	file = open (location, O_RDONLY);
339 	if (file < 0) {
340 		fprintf (stderr, "File %s could not be opened for reading\n", location);
341 		goto error;
342 	}
343 
344 	retval = fstat(file, &buf);
345 	if (retval) {
346 		fprintf(stderr, "File %s could not be stat()'ed\n", location);
347 		goto error;
348 	}
349 
350 	if (buf.st_mtime > 0xffffffff) {
351 		fprintf(stderr, "%s: Timestamp exceeds maximum cpio timestamp, clipping.\n",
352 			location);
353 		buf.st_mtime = 0xffffffff;
354 	}
355 
356 	if (buf.st_size > 0xffffffff) {
357 		fprintf(stderr, "%s: Size exceeds maximum cpio file size\n",
358 			location);
359 		goto error;
360 	}
361 
362 	if (do_csum && cpio_mkfile_csum(file, buf.st_size, &csum) < 0) {
363 		fprintf(stderr, "Failed to checksum file %s\n", location);
364 		goto error;
365 	}
366 
367 	size = 0;
368 	for (i = 1; i <= nlinks; i++) {
369 		/* data goes on last link */
370 		if (i == nlinks)
371 			size = buf.st_size;
372 
373 		if (name[0] == '/')
374 			name++;
375 		namesize = strlen(name) + 1;
376 		sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
377 		       "%08lX%08X%08X%08X%08X%08X%08X",
378 			do_csum ? "070702" : "070701", /* magic */
379 			ino,			/* ino */
380 			mode,			/* mode */
381 			(long) uid,		/* uid */
382 			(long) gid,		/* gid */
383 			nlinks,			/* nlink */
384 			(long) buf.st_mtime,	/* mtime */
385 			size,			/* filesize */
386 			3,			/* major */
387 			1,			/* minor */
388 			0,			/* rmajor */
389 			0,			/* rminor */
390 			namesize,		/* namesize */
391 			size ? csum : 0);	/* chksum */
392 		push_hdr(s);
393 		push_string(name);
394 		push_pad();
395 
396 		while (size) {
397 			unsigned char filebuf[65536];
398 			ssize_t this_read;
399 			size_t this_size = MIN(size, sizeof(filebuf));
400 
401 			this_read = read(file, filebuf, this_size);
402 			if (this_read <= 0 || this_read > this_size) {
403 				fprintf(stderr, "Can not read %s file\n", location);
404 				goto error;
405 			}
406 
407 			if (fwrite(filebuf, this_read, 1, stdout) != 1) {
408 				fprintf(stderr, "writing filebuf failed\n");
409 				goto error;
410 			}
411 			offset += this_read;
412 			size -= this_read;
413 		}
414 		push_pad();
415 
416 		name += namesize;
417 	}
418 	ino++;
419 	rc = 0;
420 
421 error:
422 	if (file >= 0)
423 		close(file);
424 	return rc;
425 }
426 
cpio_replace_env(char * new_location)427 static char *cpio_replace_env(char *new_location)
428 {
429 	char expanded[PATH_MAX + 1];
430 	char *start, *end, *var;
431 
432 	while ((start = strstr(new_location, "${")) &&
433 	       (end = strchr(start + 2, '}'))) {
434 		*start = *end = 0;
435 		var = getenv(start + 2);
436 		snprintf(expanded, sizeof expanded, "%s%s%s",
437 			 new_location, var ? var : "", end + 1);
438 		strcpy(new_location, expanded);
439 	}
440 
441 	return new_location;
442 }
443 
cpio_mkfile_line(const char * line)444 static int cpio_mkfile_line(const char *line)
445 {
446 	char name[PATH_MAX + 1];
447 	char *dname = NULL; /* malloc'ed buffer for hard links */
448 	char location[PATH_MAX + 1];
449 	unsigned int mode;
450 	int uid;
451 	int gid;
452 	int nlinks = 1;
453 	int end = 0, dname_len = 0;
454 	int rc = -1;
455 
456 	if (5 > sscanf(line, "%" str(PATH_MAX) "s %" str(PATH_MAX)
457 				"s %o %d %d %n",
458 				name, location, &mode, &uid, &gid, &end)) {
459 		fprintf(stderr, "Unrecognized file format '%s'", line);
460 		goto fail;
461 	}
462 	if (end && isgraph(line[end])) {
463 		int len;
464 		int nend;
465 
466 		dname = malloc(strlen(line));
467 		if (!dname) {
468 			fprintf (stderr, "out of memory (%d)\n", dname_len);
469 			goto fail;
470 		}
471 
472 		dname_len = strlen(name) + 1;
473 		memcpy(dname, name, dname_len);
474 
475 		do {
476 			nend = 0;
477 			if (sscanf(line + end, "%" str(PATH_MAX) "s %n",
478 					name, &nend) < 1)
479 				break;
480 			len = strlen(name) + 1;
481 			memcpy(dname + dname_len, name, len);
482 			dname_len += len;
483 			nlinks++;
484 			end += nend;
485 		} while (isgraph(line[end]));
486 	} else {
487 		dname = name;
488 	}
489 	rc = cpio_mkfile(dname, cpio_replace_env(location),
490 	                 mode, uid, gid, nlinks);
491  fail:
492 	if (dname_len) free(dname);
493 	return rc;
494 }
495 
usage(const char * prog)496 static void usage(const char *prog)
497 {
498 	fprintf(stderr, "Usage:\n"
499 		"\t%s [-t <timestamp>] [-c] <cpio_list>\n"
500 		"\n"
501 		"<cpio_list> is a file containing newline separated entries that\n"
502 		"describe the files to be included in the initramfs archive:\n"
503 		"\n"
504 		"# a comment\n"
505 		"file <name> <location> <mode> <uid> <gid> [<hard links>]\n"
506 		"dir <name> <mode> <uid> <gid>\n"
507 		"nod <name> <mode> <uid> <gid> <dev_type> <maj> <min>\n"
508 		"slink <name> <target> <mode> <uid> <gid>\n"
509 		"pipe <name> <mode> <uid> <gid>\n"
510 		"sock <name> <mode> <uid> <gid>\n"
511 		"\n"
512 		"<name>       name of the file/dir/nod/etc in the archive\n"
513 		"<location>   location of the file in the current filesystem\n"
514 		"             expands shell variables quoted with ${}\n"
515 		"<target>     link target\n"
516 		"<mode>       mode/permissions of the file\n"
517 		"<uid>        user id (0=root)\n"
518 		"<gid>        group id (0=root)\n"
519 		"<dev_type>   device type (b=block, c=character)\n"
520 		"<maj>        major number of nod\n"
521 		"<min>        minor number of nod\n"
522 		"<hard links> space separated list of other links to file\n"
523 		"\n"
524 		"example:\n"
525 		"# A simple initramfs\n"
526 		"dir /dev 0755 0 0\n"
527 		"nod /dev/console 0600 0 0 c 5 1\n"
528 		"dir /root 0700 0 0\n"
529 		"dir /sbin 0755 0 0\n"
530 		"file /sbin/kinit /usr/src/klibc/kinit/kinit 0755 0 0\n"
531 		"\n"
532 		"<timestamp> is time in seconds since Epoch that will be used\n"
533 		"as mtime for symlinks, special files and directories. The default\n"
534 		"is to use the current time for these entries.\n"
535 		"-c: calculate and store 32-bit checksums for file data.\n",
536 		prog);
537 }
538 
539 static const struct file_handler file_handler_table[] = {
540 	{
541 		.type    = "file",
542 		.handler = cpio_mkfile_line,
543 	}, {
544 		.type    = "nod",
545 		.handler = cpio_mknod_line,
546 	}, {
547 		.type    = "dir",
548 		.handler = cpio_mkdir_line,
549 	}, {
550 		.type    = "slink",
551 		.handler = cpio_mkslink_line,
552 	}, {
553 		.type    = "pipe",
554 		.handler = cpio_mkpipe_line,
555 	}, {
556 		.type    = "sock",
557 		.handler = cpio_mksock_line,
558 	}, {
559 		.type    = NULL,
560 		.handler = NULL,
561 	}
562 };
563 
564 #define LINE_SIZE (2 * PATH_MAX + 50)
565 
main(int argc,char * argv[])566 int main (int argc, char *argv[])
567 {
568 	FILE *cpio_list;
569 	char line[LINE_SIZE];
570 	char *args, *type;
571 	int ec = 0;
572 	int line_nr = 0;
573 	const char *filename;
574 
575 	default_mtime = time(NULL);
576 	while (1) {
577 		int opt = getopt(argc, argv, "t:ch");
578 		char *invalid;
579 
580 		if (opt == -1)
581 			break;
582 		switch (opt) {
583 		case 't':
584 			default_mtime = strtol(optarg, &invalid, 10);
585 			if (!*optarg || *invalid) {
586 				fprintf(stderr, "Invalid timestamp: %s\n",
587 						optarg);
588 				usage(argv[0]);
589 				exit(1);
590 			}
591 			break;
592 		case 'c':
593 			do_csum = true;
594 			break;
595 		case 'h':
596 		case '?':
597 			usage(argv[0]);
598 			exit(opt == 'h' ? 0 : 1);
599 		}
600 	}
601 
602 	/*
603 	 * Timestamps after 2106-02-07 06:28:15 UTC have an ascii hex time_t
604 	 * representation that exceeds 8 chars and breaks the cpio header
605 	 * specification.
606 	 */
607 	if (default_mtime > 0xffffffff) {
608 		fprintf(stderr, "ERROR: Timestamp too large for cpio format\n");
609 		exit(1);
610 	}
611 
612 	if (argc - optind != 1) {
613 		usage(argv[0]);
614 		exit(1);
615 	}
616 	filename = argv[optind];
617 	if (!strcmp(filename, "-"))
618 		cpio_list = stdin;
619 	else if (!(cpio_list = fopen(filename, "r"))) {
620 		fprintf(stderr, "ERROR: unable to open '%s': %s\n\n",
621 			filename, strerror(errno));
622 		usage(argv[0]);
623 		exit(1);
624 	}
625 
626 	while (fgets(line, LINE_SIZE, cpio_list)) {
627 		int type_idx;
628 		size_t slen = strlen(line);
629 
630 		line_nr++;
631 
632 		if ('#' == *line) {
633 			/* comment - skip to next line */
634 			continue;
635 		}
636 
637 		if (! (type = strtok(line, " \t"))) {
638 			fprintf(stderr,
639 				"ERROR: incorrect format, could not locate file type line %d: '%s'\n",
640 				line_nr, line);
641 			ec = -1;
642 			break;
643 		}
644 
645 		if ('\n' == *type) {
646 			/* a blank line */
647 			continue;
648 		}
649 
650 		if (slen == strlen(type)) {
651 			/* must be an empty line */
652 			continue;
653 		}
654 
655 		if (! (args = strtok(NULL, "\n"))) {
656 			fprintf(stderr,
657 				"ERROR: incorrect format, newline required line %d: '%s'\n",
658 				line_nr, line);
659 			ec = -1;
660 		}
661 
662 		for (type_idx = 0; file_handler_table[type_idx].type; type_idx++) {
663 			int rc;
664 			if (! strcmp(line, file_handler_table[type_idx].type)) {
665 				if ((rc = file_handler_table[type_idx].handler(args))) {
666 					ec = rc;
667 					fprintf(stderr, " line %d\n", line_nr);
668 				}
669 				break;
670 			}
671 		}
672 
673 		if (NULL == file_handler_table[type_idx].type) {
674 			fprintf(stderr, "unknown file type line %d: '%s'\n",
675 				line_nr, line);
676 		}
677 	}
678 	if (ec == 0)
679 		cpio_trailer();
680 
681 	exit(ec);
682 }
683