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