gen_init_cpio: avoid stack overflow when expanding
[deliverable/linux.git] / usr / gen_init_cpio.c
CommitLineData
1da177e4
LT
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
24fa5096 17 * Hard link support by Luciano Rocha
1da177e4
LT
18 */
19
20#define xstr(s) #s
21#define str(s) xstr(s)
22
23static unsigned int offset;
24static unsigned int ino = 721;
a8b8017c 25static time_t default_mtime;
1da177e4
LT
26
27struct file_handler {
28 const char *type;
29 int (*handler)(const char *line);
30};
31
32static 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
41static void push_pad (void)
42{
43 while (offset & 3) {
44 putchar(0);
45 offset++;
46 }
47}
48
49static 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
66static void push_hdr(const char *s)
67{
68 fputs(s, stdout);
69 offset += 110;
70}
71
72static 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
102static int cpio_mkslink(const char *name, const char *target,
103 unsigned int mode, uid_t uid, gid_t gid)
104{
105 char s[256];
1da177e4 106
43f901fb
TC
107 if (name[0] == '/')
108 name++;
1da177e4
LT
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 */
a8b8017c 117 (long) default_mtime, /* mtime */
1da177e4
LT
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
133static 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
151static int cpio_mkgeneric(const char *name, unsigned int mode,
152 uid_t uid, gid_t gid)
153{
154 char s[256];
1da177e4 155
43f901fb
TC
156 if (name[0] == '/')
157 name++;
1da177e4
LT
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 */
a8b8017c 166 (long) default_mtime, /* mtime */
1da177e4
LT
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
179enum generic_types {
180 GT_DIR,
181 GT_PIPE,
182 GT_SOCK
183};
184
185struct generic_type {
186 const char *type;
187 mode_t mode;
188};
189
190static 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
205static 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
224static int cpio_mkdir_line(const char *line)
225{
226 return cpio_mkgeneric_line(line, GT_DIR);
227}
228
229static int cpio_mkpipe_line(const char *line)
230{
231 return cpio_mkgeneric_line(line, GT_PIPE);
232}
233
234static int cpio_mksock_line(const char *line)
235{
236 return cpio_mkgeneric_line(line, GT_SOCK);
237}
238
239static 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];
1da177e4
LT
244
245 if (dev_type == 'b')
246 mode |= S_IFBLK;
247 else
248 mode |= S_IFCHR;
249
43f901fb
TC
250 if (name[0] == '/')
251 name++;
1da177e4
LT
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 */
a8b8017c 260 (long) default_mtime, /* mtime */
1da177e4
LT
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
273static 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
1da177e4 294static int cpio_mkfile(const char *name, const char *location,
24fa5096
LR
295 unsigned int mode, uid_t uid, gid_t gid,
296 unsigned int nlinks)
1da177e4
LT
297{
298 char s[256];
299 char *filebuf = NULL;
300 struct stat buf;
24fa5096 301 long size;
1da177e4
LT
302 int file = -1;
303 int retval;
304 int rc = -1;
24fa5096 305 int namesize;
20f1de65 306 unsigned int i;
1da177e4
LT
307
308 mode |= S_IFREG;
309
1da177e4
LT
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
a3c888fc 316 retval = fstat(file, &buf);
96aebafa 317 if (retval) {
a3c888fc 318 fprintf(stderr, "File %s could not be stat()'ed\n", location);
96aebafa
JJ
319 goto error;
320 }
321
1da177e4
LT
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
24fa5096
LR
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
43f901fb
TC
339 if (name[0] == '/')
340 name++;
24fa5096
LR
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) {
6d87fea4
MF
363 if (fwrite(filebuf, size, 1, stdout) != 1) {
364 fprintf(stderr, "writing filebuf failed\n");
365 goto error;
366 }
24fa5096
LR
367 offset += size;
368 push_pad();
369 }
370
371 name += namesize;
372 }
373 ino++;
1da177e4
LT
374 rc = 0;
375
376error:
377 if (filebuf) free(filebuf);
378 if (file >= 0) close(file);
379 return rc;
380}
381
3b1ec9fb
SG
382static char *cpio_replace_env(char *new_location)
383{
20f1de65
KC
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),
396 PATH_MAX - strlen(expanded));
397 strncat(expanded, end + 1,
398 PATH_MAX - strlen(expanded));
399 strncpy(new_location, expanded, PATH_MAX);
400 new_location[PATH_MAX] = 0;
401 } else
402 break;
403 }
404
405 return new_location;
3b1ec9fb
SG
406}
407
408
1da177e4
LT
409static int cpio_mkfile_line(const char *line)
410{
411 char name[PATH_MAX + 1];
24fa5096 412 char *dname = NULL; /* malloc'ed buffer for hard links */
1da177e4
LT
413 char location[PATH_MAX + 1];
414 unsigned int mode;
415 int uid;
416 int gid;
24fa5096
LR
417 int nlinks = 1;
418 int end = 0, dname_len = 0;
1da177e4
LT
419 int rc = -1;
420
24fa5096
LR
421 if (5 > sscanf(line, "%" str(PATH_MAX) "s %" str(PATH_MAX)
422 "s %o %d %d %n",
423 name, location, &mode, &uid, &gid, &end)) {
1da177e4
LT
424 fprintf(stderr, "Unrecognized file format '%s'", line);
425 goto fail;
426 }
24fa5096
LR
427 if (end && isgraph(line[end])) {
428 int len;
429 int nend;
430
431 dname = malloc(strlen(line));
432 if (!dname) {
433 fprintf (stderr, "out of memory (%d)\n", dname_len);
434 goto fail;
435 }
436
437 dname_len = strlen(name) + 1;
438 memcpy(dname, name, dname_len);
439
440 do {
441 nend = 0;
442 if (sscanf(line + end, "%" str(PATH_MAX) "s %n",
443 name, &nend) < 1)
444 break;
445 len = strlen(name) + 1;
446 memcpy(dname + dname_len, name, len);
447 dname_len += len;
448 nlinks++;
449 end += nend;
450 } while (isgraph(line[end]));
451 } else {
452 dname = name;
453 }
3b1ec9fb
SG
454 rc = cpio_mkfile(dname, cpio_replace_env(location),
455 mode, uid, gid, nlinks);
1da177e4 456 fail:
24fa5096 457 if (dname_len) free(dname);
1da177e4
LT
458 return rc;
459}
460
5c725138 461static void usage(const char *prog)
1da177e4
LT
462{
463 fprintf(stderr, "Usage:\n"
a8b8017c 464 "\t%s [-t <timestamp>] <cpio_list>\n"
1da177e4
LT
465 "\n"
466 "<cpio_list> is a file containing newline separated entries that\n"
467 "describe the files to be included in the initramfs archive:\n"
468 "\n"
469 "# a comment\n"
24fa5096 470 "file <name> <location> <mode> <uid> <gid> [<hard links>]\n"
1da177e4
LT
471 "dir <name> <mode> <uid> <gid>\n"
472 "nod <name> <mode> <uid> <gid> <dev_type> <maj> <min>\n"
473 "slink <name> <target> <mode> <uid> <gid>\n"
474 "pipe <name> <mode> <uid> <gid>\n"
475 "sock <name> <mode> <uid> <gid>\n"
476 "\n"
24fa5096
LR
477 "<name> name of the file/dir/nod/etc in the archive\n"
478 "<location> location of the file in the current filesystem\n"
3b1ec9fb 479 " expands shell variables quoted with ${}\n"
24fa5096
LR
480 "<target> link target\n"
481 "<mode> mode/permissions of the file\n"
482 "<uid> user id (0=root)\n"
483 "<gid> group id (0=root)\n"
484 "<dev_type> device type (b=block, c=character)\n"
485 "<maj> major number of nod\n"
486 "<min> minor number of nod\n"
487 "<hard links> space separated list of other links to file\n"
1da177e4
LT
488 "\n"
489 "example:\n"
490 "# A simple initramfs\n"
491 "dir /dev 0755 0 0\n"
492 "nod /dev/console 0600 0 0 c 5 1\n"
493 "dir /root 0700 0 0\n"
494 "dir /sbin 0755 0 0\n"
a8b8017c
MM
495 "file /sbin/kinit /usr/src/klibc/kinit/kinit 0755 0 0\n"
496 "\n"
497 "<timestamp> is time in seconds since Epoch that will be used\n"
498 "as mtime for symlinks, special files and directories. The default\n"
499 "is to use the current time for these entries.\n",
1da177e4
LT
500 prog);
501}
502
503struct file_handler file_handler_table[] = {
504 {
505 .type = "file",
506 .handler = cpio_mkfile_line,
507 }, {
508 .type = "nod",
509 .handler = cpio_mknod_line,
510 }, {
511 .type = "dir",
512 .handler = cpio_mkdir_line,
513 }, {
514 .type = "slink",
515 .handler = cpio_mkslink_line,
516 }, {
517 .type = "pipe",
518 .handler = cpio_mkpipe_line,
519 }, {
520 .type = "sock",
521 .handler = cpio_mksock_line,
522 }, {
523 .type = NULL,
524 .handler = NULL,
525 }
526};
527
528#define LINE_SIZE (2 * PATH_MAX + 50)
529
530int main (int argc, char *argv[])
531{
532 FILE *cpio_list;
533 char line[LINE_SIZE];
534 char *args, *type;
535 int ec = 0;
536 int line_nr = 0;
a8b8017c
MM
537 const char *filename;
538
539 default_mtime = time(NULL);
540 while (1) {
541 int opt = getopt(argc, argv, "t:h");
542 char *invalid;
543
544 if (opt == -1)
545 break;
546 switch (opt) {
547 case 't':
548 default_mtime = strtol(optarg, &invalid, 10);
549 if (!*optarg || *invalid) {
550 fprintf(stderr, "Invalid timestamp: %s\n",
551 optarg);
552 usage(argv[0]);
553 exit(1);
554 }
555 break;
556 case 'h':
557 case '?':
558 usage(argv[0]);
559 exit(opt == 'h' ? 0 : 1);
560 }
561 }
1da177e4 562
a8b8017c 563 if (argc - optind != 1) {
1da177e4
LT
564 usage(argv[0]);
565 exit(1);
566 }
a8b8017c
MM
567 filename = argv[optind];
568 if (!strcmp(filename, "-"))
f2434ec1 569 cpio_list = stdin;
a8b8017c 570 else if (!(cpio_list = fopen(filename, "r"))) {
1da177e4 571 fprintf(stderr, "ERROR: unable to open '%s': %s\n\n",
a8b8017c 572 filename, strerror(errno));
1da177e4
LT
573 usage(argv[0]);
574 exit(1);
575 }
576
577 while (fgets(line, LINE_SIZE, cpio_list)) {
578 int type_idx;
579 size_t slen = strlen(line);
580
581 line_nr++;
582
583 if ('#' == *line) {
584 /* comment - skip to next line */
585 continue;
586 }
587
588 if (! (type = strtok(line, " \t"))) {
589 fprintf(stderr,
590 "ERROR: incorrect format, could not locate file type line %d: '%s'\n",
591 line_nr, line);
592 ec = -1;
aa1e816f 593 break;
1da177e4
LT
594 }
595
596 if ('\n' == *type) {
597 /* a blank line */
598 continue;
599 }
600
601 if (slen == strlen(type)) {
602 /* must be an empty line */
603 continue;
604 }
605
606 if (! (args = strtok(NULL, "\n"))) {
607 fprintf(stderr,
608 "ERROR: incorrect format, newline required line %d: '%s'\n",
609 line_nr, line);
610 ec = -1;
611 }
612
613 for (type_idx = 0; file_handler_table[type_idx].type; type_idx++) {
614 int rc;
615 if (! strcmp(line, file_handler_table[type_idx].type)) {
616 if ((rc = file_handler_table[type_idx].handler(args))) {
617 ec = rc;
618 fprintf(stderr, " line %d\n", line_nr);
619 }
620 break;
621 }
622 }
623
624 if (NULL == file_handler_table[type_idx].type) {
625 fprintf(stderr, "unknown file type line %d: '%s'\n",
626 line_nr, line);
627 }
628 }
aa1e816f
JJ
629 if (ec == 0)
630 cpio_trailer();
1da177e4
LT
631
632 exit(ec);
633}
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