1 /*-
2 * Copyright (c) 2007-2014, Juniper Networks, Inc.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29
30 #include "stand.h"
31
32 #include <sys/stat.h>
33 #include <sys/stdint.h>
34 #include <string.h>
35 #include <zlib.h>
36
37 #ifdef PKGFS_DEBUG
38 #define DBG(x) printf x
39 #else
40 #define DBG(x)
41 #endif
42
43 static int pkg_open(const char *, struct open_file *);
44 static int pkg_close(struct open_file *);
45 static int pkg_read(struct open_file *, void *, size_t, size_t *);
46 static off_t pkg_seek(struct open_file *, off_t, int);
47 static int pkg_stat(struct open_file *, struct stat *);
48 static int pkg_readdir(struct open_file *, struct dirent *);
49 static off_t pkg_atol(const char *, unsigned);
50
51 struct fs_ops pkgfs_fsops = {
52 "pkg",
53 pkg_open,
54 pkg_close,
55 pkg_read,
56 null_write,
57 pkg_seek,
58 pkg_stat,
59 pkg_readdir
60 };
61
62 #define PKG_BUFSIZE 512
63 #define PKG_MAXCACHESZ (512 * 1024)
64
65 #define PKG_FILEEXT ".tgz"
66
67 /*
68 * Layout of POSIX 'ustar' header.
69 */
70 struct ustar_hdr {
71 char ut_name[100];
72 char ut_mode[8];
73 char ut_uid[8];
74 char ut_gid[8];
75 char ut_size[12];
76 char ut_mtime[12];
77 char ut_checksum[8];
78 char ut_typeflag[1];
79 char ut_linkname[100];
80 char ut_magic[6]; /* For POSIX: "ustar\0" */
81 char ut_version[2]; /* For POSIX: "00" */
82 char ut_uname[32];
83 char ut_gname[32];
84 char ut_rdevmajor[8];
85 char ut_rdevminor[8];
86 union {
87 struct {
88 char prefix[155];
89 } posix;
90 struct {
91 char atime[12];
92 char ctime[12];
93 char offset[12];
94 char longnames[4];
95 char unused[1];
96 struct gnu_sparse {
97 char offset[12];
98 char numbytes[12];
99 } sparse[4];
100 char isextended[1];
101 char realsize[12];
102 } gnu;
103 } u;
104 u_char __padding[12];
105 };
106
107 struct package;
108
109 struct tarfile
110 {
111 struct package *tf_pkg;
112 struct tarfile *tf_next;
113 struct ustar_hdr tf_hdr;
114 off_t tf_ofs;
115 off_t tf_size;
116 off_t tf_fp;
117 size_t tf_cachesz;
118 void *tf_cache;
119 };
120
121 struct package
122 {
123 struct package *pkg_chain;
124 int pkg_fd;
125 off_t pkg_ofs;
126 z_stream pkg_zs;
127 struct tarfile *pkg_first;
128 struct tarfile *pkg_last;
129 u_char pkg_buf[PKG_BUFSIZE];
130 };
131
132 static struct package *package = NULL;
133
134 static int new_package(int, struct package **);
135 static int cache_data(struct tarfile *tf, int);
136
137 void
pkgfs_cleanup(void)138 pkgfs_cleanup(void)
139 {
140 struct package *chain;
141 struct tarfile *tf, *tfn;
142
143 while (package != NULL) {
144 inflateEnd(&package->pkg_zs);
145 close(package->pkg_fd);
146
147 tf = package->pkg_first;
148 while (tf != NULL) {
149 tfn = tf->tf_next;
150 if (tf->tf_cachesz > 0)
151 free(tf->tf_cache);
152 free(tf);
153 tf = tfn;
154 }
155
156 chain = package->pkg_chain;
157 free(package);
158 package = chain;
159 }
160 }
161
162 int
pkgfs_init(const char * pkgname,struct fs_ops * proto)163 pkgfs_init(const char *pkgname, struct fs_ops *proto)
164 {
165 struct package *pkg;
166 int error, fd;
167
168 pkg = NULL;
169 if (proto != &pkgfs_fsops)
170 pkgfs_cleanup();
171
172 exclusive_file_system = proto;
173
174 fd = open(pkgname, O_RDONLY);
175
176 exclusive_file_system = NULL;
177
178 if (fd == -1)
179 return (errno);
180
181 error = new_package(fd, &pkg);
182 if (error) {
183 close(fd);
184 return (error);
185 }
186
187 if (pkg == NULL)
188 return (EDOOFUS);
189
190 pkg->pkg_chain = package;
191 package = pkg;
192 exclusive_file_system = &pkgfs_fsops;
193 return (0);
194 }
195
196 static int get_mode(struct tarfile *);
197 static int get_zipped(struct package *, void *, size_t);
198 static int new_package(int, struct package **);
199 static struct tarfile *scan_tarfile(struct package *, struct tarfile *);
200
201 static int
pkg_open_follow(const char * fn,struct open_file * f,int lnks)202 pkg_open_follow(const char *fn, struct open_file *f, int lnks)
203 {
204 struct tarfile *tf;
205
206 if (fn == NULL || f == NULL)
207 return (EINVAL);
208
209 if (package == NULL)
210 return (ENXIO);
211
212 /*
213 * We can only read from a package, so reject request to open
214 * for write-only or read-write.
215 */
216 if (f->f_flags != F_READ)
217 return (EPERM);
218
219 /*
220 * Scan the file headers for the named file. We stop scanning
221 * at the first filename that has the .pkg extension. This is
222 * a package within a package. We assume we have all the files
223 * we need up-front and without having to dig within nested
224 * packages.
225 *
226 * Note that we preserve streaming properties as much as possible.
227 */
228 while (*fn == '/')
229 fn++;
230
231 /*
232 * Allow opening of the root directory for use by readdir()
233 * to support listing files in the package.
234 */
235 if (*fn == '\0') {
236 f->f_fsdata = NULL;
237 return (0);
238 }
239
240 tf = scan_tarfile(package, NULL);
241 while (tf != NULL) {
242 if (strcmp(fn, tf->tf_hdr.ut_name) == 0) {
243 f->f_fsdata = tf;
244 tf->tf_fp = 0; /* Reset the file pointer. */
245 DBG(("%s: found %s type %c\n", __func__,
246 fn, tf->tf_hdr.ut_typeflag[0]));
247 if (tf->tf_hdr.ut_typeflag[0] == '2') {
248 /* we have a symlink
249 * Note: ut_linkname is only 100 chars!
250 */
251 if (lnks++ >= 8)
252 return (EMLINK);
253 return pkg_open_follow(tf->tf_hdr.ut_linkname,
254 f, lnks);
255 }
256 return (0);
257 }
258 tf = scan_tarfile(package, tf);
259 }
260 return (errno);
261 }
262
263 static int
pkg_open(const char * fn,struct open_file * f)264 pkg_open(const char *fn, struct open_file *f)
265 {
266 return pkg_open_follow(fn, f, 0);
267 }
268
269 static int
pkg_close(struct open_file * f)270 pkg_close(struct open_file *f)
271 {
272 struct tarfile *tf;
273
274 tf = (struct tarfile *)f->f_fsdata;
275 if (tf == NULL)
276 return (0);
277
278 /*
279 * Free up the cache if we read all of the file.
280 */
281 if (tf->tf_fp == tf->tf_size && tf->tf_cachesz > 0) {
282 free(tf->tf_cache);
283 tf->tf_cachesz = 0;
284 }
285 return (0);
286 }
287
288 static int
pkg_read(struct open_file * f,void * buf,size_t size,size_t * res)289 pkg_read(struct open_file *f, void *buf, size_t size, size_t *res)
290 {
291 struct tarfile *tf;
292 char *p;
293 off_t fp;
294 size_t sz;
295
296 tf = (struct tarfile *)f->f_fsdata;
297 if (tf == NULL) {
298 if (res != NULL)
299 *res = size;
300 return (EBADF);
301 }
302
303 if (tf->tf_cachesz == 0)
304 cache_data(tf, 1);
305
306 fp = tf->tf_fp;
307 p = buf;
308 sz = 0;
309 while (size > 0) {
310 sz = tf->tf_size - fp;
311 if (fp < tf->tf_cachesz && tf->tf_cachesz < tf->tf_size)
312 sz = tf->tf_cachesz - fp;
313 if (size < sz)
314 sz = size;
315 if (sz == 0)
316 break;
317
318 if (fp < tf->tf_cachesz) {
319 /* Satisfy the request from cache. */
320 memcpy(p, tf->tf_cache + fp, sz);
321 fp += sz;
322 p += sz;
323 size -= sz;
324 continue;
325 }
326
327 if (get_zipped(tf->tf_pkg, p, sz) == -1) {
328 sz = -1;
329 break;
330 }
331
332 fp += sz;
333 p += sz;
334 size -= sz;
335 }
336
337 tf->tf_fp = fp;
338 if (res != NULL)
339 *res = size;
340 return ((sz == -1) ? errno : 0);
341 }
342
343 static off_t
pkg_seek(struct open_file * f,off_t ofs,int whence)344 pkg_seek(struct open_file *f, off_t ofs, int whence)
345 {
346 char buf[512];
347 struct tarfile *tf;
348 off_t delta;
349 off_t nofs;
350 size_t sz, res;
351 int error;
352
353 tf = (struct tarfile *)f->f_fsdata;
354 if (tf == NULL) {
355 errno = EBADF;
356 return (-1);
357 }
358
359 switch (whence) {
360 case SEEK_SET:
361 delta = ofs - tf->tf_fp;
362 break;
363 case SEEK_CUR:
364 delta = ofs;
365 break;
366 case SEEK_END:
367 delta = tf->tf_size - tf->tf_fp + ofs;
368 break;
369 default:
370 errno = EINVAL;
371 return (-1);
372 }
373
374 if (delta < 0) {
375 /* seeking backwards - ok if within cache */
376 if (tf->tf_cachesz > 0 && tf->tf_fp <= tf->tf_cachesz) {
377 nofs = tf->tf_fp + delta;
378 if (nofs >= 0) {
379 tf->tf_fp = nofs;
380 return (tf->tf_fp);
381 }
382 }
383 DBG(("%s: negative file seek (%jd)\n", __func__,
384 (intmax_t)delta));
385 errno = ESPIPE;
386 return (-1);
387 }
388
389 while (delta > 0 && tf->tf_fp < tf->tf_size) {
390 sz = (delta > sizeof(buf)) ? sizeof(buf) : delta;
391 error = pkg_read(f, buf, sz, &res);
392 if (error != 0) {
393 errno = error;
394 return (-1);
395 }
396 delta -= sz - res;
397 }
398
399 return (tf->tf_fp);
400 }
401
402 static int
pkg_stat(struct open_file * f,struct stat * sb)403 pkg_stat(struct open_file *f, struct stat *sb)
404 {
405 struct tarfile *tf;
406
407 tf = (struct tarfile *)f->f_fsdata;
408 if (tf == NULL)
409 return (EBADF);
410 memset(sb, 0, sizeof(*sb));
411 sb->st_mode = get_mode(tf);
412 if ((sb->st_mode & S_IFMT) == 0) {
413 /* tar file bug - assume regular file */
414 sb->st_mode |= S_IFREG;
415 }
416 sb->st_size = tf->tf_size;
417 sb->st_blocks = (tf->tf_size + 511) / 512;
418 sb->st_mtime = pkg_atol(tf->tf_hdr.ut_mtime, 12);
419 sb->st_dev = (off_t)((uintptr_t)tf->tf_pkg);
420 sb->st_ino = tf->tf_ofs; /* unique per tf_pkg */
421 return (0);
422 }
423
424 static int
pkg_readdir(struct open_file * f,struct dirent * d)425 pkg_readdir(struct open_file *f, struct dirent *d)
426 {
427 struct tarfile *tf;
428
429 tf = (struct tarfile *)f->f_fsdata;
430 if (tf != NULL)
431 return (EBADF);
432
433 tf = scan_tarfile(package, NULL);
434 if (tf == NULL)
435 return (ENOENT);
436
437 d->d_fileno = 0;
438 d->d_reclen = sizeof(*d);
439 d->d_type = DT_REG;
440 memcpy(d->d_name, tf->tf_hdr.ut_name, sizeof(d->d_name));
441 return (0);
442 }
443
444 /*
445 * Low-level support functions.
446 */
447
448 static int
get_byte(struct package * pkg,off_t * op)449 get_byte(struct package *pkg, off_t *op)
450 {
451 int c;
452
453 if (pkg->pkg_zs.avail_in == 0) {
454 c = read(pkg->pkg_fd, pkg->pkg_buf, PKG_BUFSIZE);
455 if (c <= 0)
456 return (-1);
457 pkg->pkg_zs.avail_in = c;
458 pkg->pkg_zs.next_in = pkg->pkg_buf;
459 }
460
461 c = *pkg->pkg_zs.next_in;
462 pkg->pkg_zs.next_in++;
463 pkg->pkg_zs.avail_in--;
464 (*op)++;
465 return (c);
466 }
467
468 static int
get_zipped(struct package * pkg,void * buf,size_t bufsz)469 get_zipped(struct package *pkg, void *buf, size_t bufsz)
470 {
471 int c;
472
473 pkg->pkg_zs.next_out = buf;
474 pkg->pkg_zs.avail_out = bufsz;
475
476 while (pkg->pkg_zs.avail_out) {
477 if (pkg->pkg_zs.avail_in == 0) {
478 c = read(pkg->pkg_fd, pkg->pkg_buf, PKG_BUFSIZE);
479 if (c <= 0) {
480 errno = EIO;
481 return (-1);
482 }
483 pkg->pkg_zs.avail_in = c;
484 pkg->pkg_zs.next_in = pkg->pkg_buf;
485 }
486
487 c = inflate(&pkg->pkg_zs, Z_SYNC_FLUSH);
488 if (c != Z_OK && c != Z_STREAM_END) {
489 errno = EIO;
490 return (-1);
491 }
492 }
493
494 pkg->pkg_ofs += bufsz;
495 return (0);
496 }
497
498 /**
499 * @brief
500 * cache data of a tarfile
501 *
502 * @param[in] tf
503 * tarfile pointer
504 *
505 * @param[in] force
506 * If file size > PKG_MAXCACHESZ, cache that much
507 *
508 * @return 0, -1 (errno set to error value)
509 */
510 static int
cache_data(struct tarfile * tf,int force)511 cache_data(struct tarfile *tf, int force)
512 {
513 struct package *pkg;
514 size_t sz;
515
516 if (tf == NULL) {
517 DBG(("%s: no file to cache data for?\n", __func__));
518 errno = EINVAL;
519 return (-1);
520 }
521
522 pkg = tf->tf_pkg;
523 if (pkg == NULL) {
524 DBG(("%s: no package associated with file?\n", __func__));
525 errno = EINVAL;
526 return (-1);
527 }
528
529 if (tf->tf_cachesz > 0) {
530 DBG(("%s: data already cached\n", __func__));
531 errno = EINVAL;
532 return (-1);
533 }
534
535 if (tf->tf_ofs != pkg->pkg_ofs) {
536 DBG(("%s: caching after force read of file %s?\n",
537 __func__, tf->tf_hdr.ut_name));
538 errno = EINVAL;
539 return (-1);
540 }
541
542 /* We don't cache everything... */
543 if (tf->tf_size > PKG_MAXCACHESZ && !force) {
544 errno = ENOBUFS;
545 return (-1);
546 }
547
548 sz = tf->tf_size < PKG_MAXCACHESZ ? tf->tf_size : PKG_MAXCACHESZ;
549 /* All files are padded to a multiple of 512 bytes. */
550 sz = (sz + 0x1ff) & ~0x1ff;
551
552 tf->tf_cache = malloc(sz);
553 if (tf->tf_cache == NULL) {
554 DBG(("%s: could not allocate %d bytes\n", __func__, (int)sz));
555 errno = ENOMEM;
556 return (-1);
557 }
558
559 tf->tf_cachesz = sz;
560 return (get_zipped(pkg, tf->tf_cache, sz));
561 }
562
563 /*
564 * Note that this implementation does not (and should not!) obey
565 * locale settings; you cannot simply substitute strtol here, since
566 * it does obey locale.
567 */
568 static off_t
pkg_atol8(const char * p,unsigned char_cnt)569 pkg_atol8(const char *p, unsigned char_cnt)
570 {
571 int64_t l, limit, last_digit_limit;
572 int digit, sign, base;
573
574 base = 8;
575 limit = INT64_MAX / base;
576 last_digit_limit = INT64_MAX % base;
577
578 while (*p == ' ' || *p == '\t')
579 p++;
580 if (*p == '-') {
581 sign = -1;
582 p++;
583 } else
584 sign = 1;
585
586 l = 0;
587 digit = *p - '0';
588 while (digit >= 0 && digit < base && char_cnt-- > 0) {
589 if (l>limit || (l == limit && digit > last_digit_limit)) {
590 l = UINT64_MAX; /* Truncate on overflow. */
591 break;
592 }
593 l = (l * base) + digit;
594 digit = *++p - '0';
595 }
596 return (sign < 0) ? -l : l;
597 }
598
599 /*
600 * Parse a base-256 integer. This is just a straight signed binary
601 * value in big-endian order, except that the high-order bit is
602 * ignored. Remember that "int64_t" may or may not be exactly 64
603 * bits; the implementation here tries to avoid making any assumptions
604 * about the actual size of an int64_t. It does assume we're using
605 * twos-complement arithmetic, though.
606 */
607 static int64_t
pkg_atol256(const char * _p,unsigned char_cnt)608 pkg_atol256(const char *_p, unsigned char_cnt)
609 {
610 int64_t l, upper_limit, lower_limit;
611 const unsigned char *p = (const unsigned char *)_p;
612
613 upper_limit = INT64_MAX / 256;
614 lower_limit = INT64_MIN / 256;
615
616 /* Pad with 1 or 0 bits, depending on sign. */
617 if ((0x40 & *p) == 0x40)
618 l = (int64_t)-1;
619 else
620 l = 0;
621 l = (l << 6) | (0x3f & *p++);
622 while (--char_cnt > 0) {
623 if (l > upper_limit) {
624 l = INT64_MAX; /* Truncate on overflow */
625 break;
626 } else if (l < lower_limit) {
627 l = INT64_MIN;
628 break;
629 }
630 l = (l << 8) | (0xff & (int64_t)*p++);
631 }
632 return (l);
633 }
634
635 static off_t
pkg_atol(const char * p,unsigned char_cnt)636 pkg_atol(const char *p, unsigned char_cnt)
637 {
638 /*
639 * Technically, GNU pkg considers a field to be in base-256
640 * only if the first byte is 0xff or 0x80.
641 */
642 if (*p & 0x80)
643 return (pkg_atol256(p, char_cnt));
644 return (pkg_atol8(p, char_cnt));
645 }
646
647 static int
get_mode(struct tarfile * tf)648 get_mode(struct tarfile *tf)
649 {
650 return (pkg_atol(tf->tf_hdr.ut_mode, sizeof(tf->tf_hdr.ut_mode)));
651 }
652
653 /* GZip flag byte */
654 #define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */
655 #define HEAD_CRC 0x02 /* bit 1 set: header CRC present */
656 #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
657 #define ORIG_NAME 0x08 /* bit 3 set: original file name present */
658 #define COMMENT 0x10 /* bit 4 set: file comment present */
659 #define RESERVED 0xE0 /* bits 5..7: reserved */
660
661 static int
new_package(int fd,struct package ** pp)662 new_package(int fd, struct package **pp)
663 {
664 struct package *pkg;
665 off_t ofs;
666 int flags, i, error;
667
668 pkg = malloc(sizeof(*pkg));
669 if (pkg == NULL)
670 return (ENOMEM);
671
672 bzero(pkg, sizeof(*pkg));
673 pkg->pkg_fd = fd;
674
675 /*
676 * Parse the header.
677 */
678 error = EFTYPE;
679 ofs = 0;
680
681 /* Check megic. */
682 if (get_byte(pkg, &ofs) != 0x1f || get_byte(pkg, &ofs) != 0x8b)
683 goto fail;
684 /* Check method. */
685 if (get_byte(pkg, &ofs) != Z_DEFLATED)
686 goto fail;
687 /* Check flags. */
688 flags = get_byte(pkg, &ofs);
689 if (flags & RESERVED)
690 goto fail;
691
692 /* Skip time, xflags and OS code. */
693 for (i = 0; i < 6; i++) {
694 if (get_byte(pkg, &ofs) == -1)
695 goto fail;
696 }
697
698 /* Skip extra field. */
699 if (flags & EXTRA_FIELD) {
700 i = (get_byte(pkg, &ofs) & 0xff) |
701 ((get_byte(pkg, &ofs) << 8) & 0xff);
702 while (i-- > 0) {
703 if (get_byte(pkg, &ofs) == -1)
704 goto fail;
705 }
706 }
707
708 /* Skip original file name. */
709 if (flags & ORIG_NAME) {
710 do {
711 i = get_byte(pkg, &ofs);
712 } while (i != 0 && i != -1);
713 if (i == -1)
714 goto fail;
715 }
716
717 /* Print the comment if it's there. */
718 if (flags & COMMENT) {
719 while (1) {
720 i = get_byte(pkg, &ofs);
721 if (i == -1)
722 goto fail;
723 if (i == 0)
724 break;
725 putchar(i);
726 }
727 }
728
729 /* Skip the CRC. */
730 if (flags & HEAD_CRC) {
731 if (get_byte(pkg, &ofs) == -1)
732 goto fail;
733 if (get_byte(pkg, &ofs) == -1)
734 goto fail;
735 }
736
737 /*
738 * Done parsing the ZIP header. Spkgt the inflation engine.
739 */
740 error = inflateInit2(&pkg->pkg_zs, -15);
741 if (error != Z_OK)
742 goto fail;
743
744 *pp = pkg;
745 return (0);
746
747 fail:
748 free(pkg);
749 return (error);
750 }
751
752 static struct tarfile *
scan_tarfile(struct package * pkg,struct tarfile * last)753 scan_tarfile(struct package *pkg, struct tarfile *last)
754 {
755 char buf[512];
756 struct tarfile *cur;
757 off_t ofs;
758 size_t sz;
759
760 cur = (last != NULL) ? last->tf_next : pkg->pkg_first;
761 if (cur == NULL) {
762 ofs = (last != NULL) ? last->tf_ofs + last->tf_size :
763 pkg->pkg_ofs;
764 ofs = (ofs + 0x1ff) & ~0x1ff;
765
766 /* Check if we've reached EOF. */
767 if (ofs < pkg->pkg_ofs) {
768 errno = ENOSPC;
769 return (NULL);
770 }
771
772 if (ofs != pkg->pkg_ofs) {
773 if (last != NULL && pkg->pkg_ofs == last->tf_ofs) {
774 if (cache_data(last, 0) == -1)
775 return (NULL);
776 } else {
777 sz = ofs - pkg->pkg_ofs;
778 while (sz != 0) {
779 if (sz > sizeof(buf))
780 sz = sizeof(buf);
781 if (get_zipped(pkg, buf, sz) == -1)
782 return (NULL);
783 sz = ofs - pkg->pkg_ofs;
784 }
785 }
786 }
787
788 cur = malloc(sizeof(*cur));
789 if (cur == NULL)
790 return (NULL);
791 memset(cur, 0, sizeof(*cur));
792 cur->tf_pkg = pkg;
793
794 while (1) {
795 if (get_zipped(pkg, &cur->tf_hdr,
796 sizeof(cur->tf_hdr)) == -1) {
797 free(cur);
798 return (NULL);
799 }
800
801 /*
802 * There are always 2 empty blocks appended to
803 * a PKG. It marks the end of the archive.
804 */
805 if (strncmp(cur->tf_hdr.ut_magic, "ustar", 5) != 0) {
806 free(cur);
807 errno = ENOSPC;
808 return (NULL);
809 }
810
811 cur->tf_ofs = pkg->pkg_ofs;
812 cur->tf_size = pkg_atol(cur->tf_hdr.ut_size,
813 sizeof(cur->tf_hdr.ut_size));
814
815 if (cur->tf_hdr.ut_name[0] != '+')
816 break;
817
818 /*
819 * Skip package meta-files.
820 */
821 ofs = cur->tf_ofs + cur->tf_size;
822 ofs = (ofs + 0x1ff) & ~0x1ff;
823 while (pkg->pkg_ofs < ofs) {
824 if (get_zipped(pkg, buf, sizeof(buf)) == -1) {
825 free(cur);
826 return (NULL);
827 }
828 }
829 }
830
831 if (last != NULL)
832 last->tf_next = cur;
833 else
834 pkg->pkg_first = cur;
835 pkg->pkg_last = cur;
836 }
837
838 return (cur);
839 }
840