xref: /dragonfly/bin/pax/tar.c (revision 57fed2af)
1 /*-
2  * Copyright (c) 1992 Keith Muller.
3  * Copyright (c) 1992, 1993
4  *	The Regents of the University of California.  All rights reserved.
5  *
6  * This code is derived from software contributed to Berkeley by
7  * Keith Muller of the University of California, San Diego.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *	This product includes software developed by the University of
20  *	California, Berkeley and its contributors.
21  * 4. Neither the name of the University nor the names of its contributors
22  *    may be used to endorse or promote products derived from this software
23  *    without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  *
37  * @(#)tar.c	8.2 (Berkeley) 4/18/94
38  * $FreeBSD: src/bin/pax/tar.c,v 1.13.2.1 2001/08/01 05:03:12 obrien Exp $
39  * $DragonFly: src/bin/pax/tar.c,v 1.5 2004/10/30 13:34:50 liamfoy Exp $
40  */
41 
42 #include <sys/types.h>
43 #include <sys/time.h>
44 #include <sys/stat.h>
45 #include <string.h>
46 #include <stdio.h>
47 #include <unistd.h>
48 #include <stdlib.h>
49 #include "pax.h"
50 #include "extern.h"
51 #include "tar.h"
52 
53 /*
54  * Routines for reading, writing and header identify of various versions of tar
55  */
56 
57 static u_long tar_chksm (char *, int);
58 static char *name_split (char *, int);
59 static int ul_oct (u_long, char *, int, int);
60 #ifndef NET2_STAT
61 static int uqd_oct (u_quad_t, char *, int, int);
62 #endif
63 
64 /*
65  * Routines common to all versions of tar
66  */
67 
68 static int tar_nodir;			/* do not write dirs under old tar */
69 
70 /*
71  * tar_endwr()
72  *	add the tar trailer of two null blocks
73  * Return:
74  *	0 if ok, -1 otherwise (what wr_skip returns)
75  */
76 
77 int
78 tar_endwr(void)
79 {
80 	return(wr_skip((off_t)(NULLCNT*BLKMULT)));
81 }
82 
83 /*
84  * tar_endrd()
85  *	no cleanup needed here, just return size of trailer (for append)
86  * Return:
87  *	size of trailer (2 * BLKMULT)
88  */
89 
90 off_t
91 tar_endrd(void)
92 {
93 	return((off_t)(NULLCNT*BLKMULT));
94 }
95 
96 /*
97  * tar_trail()
98  *	Called to determine if a header block is a valid trailer. We are passed
99  *	the block, the in_sync flag (which tells us we are in resync mode;
100  *	looking for a valid header), and cnt (which starts at zero) which is
101  *	used to count the number of empty blocks we have seen so far.
102  * Return:
103  *	0 if a valid trailer, -1 if not a valid trailer, or 1 if the block
104  *	could never contain a header.
105  */
106 
107 int
108 tar_trail(char *buf, int in_resync, int *cnt)
109 {
110 	int i;
111 
112 	/*
113 	 * look for all zero, trailer is two consecutive blocks of zero
114 	 */
115 	for (i = 0; i < BLKMULT; ++i) {
116 		if (buf[i] != '\0')
117 			break;
118 	}
119 
120 	/*
121 	 * if not all zero it is not a trailer, but MIGHT be a header.
122 	 */
123 	if (i != BLKMULT)
124 		return(-1);
125 
126 	/*
127 	 * When given a zero block, we must be careful!
128 	 * If we are not in resync mode, check for the trailer. Have to watch
129 	 * out that we do not mis-identify file data as the trailer, so we do
130 	 * NOT try to id a trailer during resync mode. During resync mode we
131 	 * might as well throw this block out since a valid header can NEVER be
132 	 * a block of all 0 (we must have a valid file name).
133 	 */
134 	if (!in_resync && (++*cnt >= NULLCNT))
135 		return(0);
136 	return(1);
137 }
138 
139 /*
140  * ul_oct()
141  *	convert an unsigned long to an octal string. many oddball field
142  *	termination characters are used by the various versions of tar in the
143  *	different fields. term selects which kind to use. str is '0' padded
144  *	at the front to len. we are unable to use only one format as many old
145  *	tar readers are very cranky about this.
146  * Return:
147  *	0 if the number fit into the string, -1 otherwise
148  */
149 
150 static int
151 ul_oct(u_long val, char *str, int len, int term)
152 {
153 	char *pt;
154 
155 	/*
156 	 * term selects the appropriate character(s) for the end of the string
157 	 */
158 	pt = str + len - 1;
159 	switch(term) {
160 	case 3:
161 		*pt-- = '\0';
162 		break;
163 	case 2:
164 		*pt-- = ' ';
165 		*pt-- = '\0';
166 		break;
167 	case 1:
168 		*pt-- = ' ';
169 		break;
170 	case 0:
171 	default:
172 		*pt-- = '\0';
173 		*pt-- = ' ';
174 		break;
175 	}
176 
177 	/*
178 	 * convert and blank pad if there is space
179 	 */
180 	while (pt >= str) {
181 		*pt-- = '0' + (char)(val & 0x7);
182 		if ((val = val >> 3) == (u_long)0)
183 			break;
184 	}
185 
186 	while (pt >= str)
187 		*pt-- = '0';
188 	if (val != (u_long)0)
189 		return(-1);
190 	return(0);
191 }
192 
193 #ifndef NET2_STAT
194 /*
195  * uqd_oct()
196  *	convert an u_quad_t to an octal string. one of many oddball field
197  *	termination characters are used by the various versions of tar in the
198  *	different fields. term selects which kind to use. str is '0' padded
199  *	at the front to len. we are unable to use only one format as many old
200  *	tar readers are very cranky about this.
201  * Return:
202  *	0 if the number fit into the string, -1 otherwise
203  */
204 
205 static int
206 uqd_oct(u_quad_t val, char *str, int len, int term)
207 {
208 	char *pt;
209 
210 	/*
211 	 * term selects the appropriate character(s) for the end of the string
212 	 */
213 	pt = str + len - 1;
214 	switch(term) {
215 	case 3:
216 		*pt-- = '\0';
217 		break;
218 	case 2:
219 		*pt-- = ' ';
220 		*pt-- = '\0';
221 		break;
222 	case 1:
223 		*pt-- = ' ';
224 		break;
225 	case 0:
226 	default:
227 		*pt-- = '\0';
228 		*pt-- = ' ';
229 		break;
230 	}
231 
232 	/*
233 	 * convert and blank pad if there is space
234 	 */
235 	while (pt >= str) {
236 		*pt-- = '0' + (char)(val & 0x7);
237 		if ((val = val >> 3) == 0)
238 			break;
239 	}
240 
241 	while (pt >= str)
242 		*pt-- = '0';
243 	if (val != (u_quad_t)0)
244 		return(-1);
245 	return(0);
246 }
247 #endif
248 
249 /*
250  * tar_chksm()
251  *	calculate the checksum for a tar block counting the checksum field as
252  *	all blanks (BLNKSUM is that value pre-calculated, the sum of 8 blanks).
253  *	NOTE: we use len to short circuit summing 0's on write since we ALWAYS
254  *	pad headers with 0.
255  * Return:
256  *	unsigned long checksum
257  */
258 
259 static u_long
260 tar_chksm(char *blk, int len)
261 {
262 	char *stop;
263 	char *pt;
264 	u_long chksm = BLNKSUM;	/* initial value is checksum field sum */
265 
266 	/*
267 	 * add the part of the block before the checksum field
268 	 */
269 	pt = blk;
270 	stop = blk + CHK_OFFSET;
271 	while (pt < stop)
272 		chksm += (u_long)(*pt++ & 0xff);
273 	/*
274 	 * move past the checksum field and keep going, spec counts the
275 	 * checksum field as the sum of 8 blanks (which is pre-computed as
276 	 * BLNKSUM).
277 	 * ASSUMED: len is greater than CHK_OFFSET. (len is where our 0 padding
278 	 * starts, no point in summing zero's)
279 	 */
280 	pt += CHK_LEN;
281 	stop = blk + len;
282 	while (pt < stop)
283 		chksm += (u_long)(*pt++ & 0xff);
284 	return(chksm);
285 }
286 
287 /*
288  * Routines for old BSD style tar (also made portable to sysV tar)
289  */
290 
291 /*
292  * tar_id()
293  *	determine if a block given to us is a valid tar header (and not a USTAR
294  *	header). We have to be on the lookout for those pesky blocks of	all
295  *	zero's.
296  * Return:
297  *	0 if a tar header, -1 otherwise
298  */
299 
300 int
301 tar_id(char *blk, int size)
302 {
303 	HD_TAR *hd;
304 	HD_USTAR *uhd;
305 
306 	if (size < BLKMULT)
307 		return(-1);
308 	hd = (HD_TAR *)blk;
309 	uhd = (HD_USTAR *)blk;
310 
311 	/*
312 	 * check for block of zero's first, a simple and fast test, then make
313 	 * sure this is not a ustar header by looking for the ustar magic
314 	 * cookie. We should use TMAGLEN, but some USTAR archive programs are
315 	 * wrong and create archives missing the \0. Last we check the
316 	 * checksum. If this is ok we have to assume it is a valid header.
317 	 */
318 	if (hd->name[0] == '\0')
319 		return(-1);
320 	if (strncmp(uhd->magic, TMAGIC, TMAGLEN - 1) == 0)
321 		return(-1);
322 	if (asc_ul(hd->chksum,sizeof(hd->chksum),OCT) != tar_chksm(blk,BLKMULT))
323 		return(-1);
324 	return(0);
325 }
326 
327 /*
328  * tar_opt()
329  *	handle tar format specific -o options
330  * Return:
331  *	0 if ok -1 otherwise
332  */
333 
334 int
335 tar_opt(void)
336 {
337 	OPLIST *opt;
338 
339 	while ((opt = opt_next()) != NULL) {
340 		if (strcmp(opt->name, TAR_OPTION) ||
341 		    strcmp(opt->value, TAR_NODIR)) {
342 			paxwarn(1, "Unknown tar format -o option/value pair %s=%s",
343 			    opt->name, opt->value);
344 			paxwarn(1,"%s=%s is the only supported tar format option",
345 			    TAR_OPTION, TAR_NODIR);
346 			return(-1);
347 		}
348 
349 		/*
350 		 * we only support one option, and only when writing
351 		 */
352 		if ((act != APPND) && (act != ARCHIVE)) {
353 			paxwarn(1, "%s=%s is only supported when writing.",
354 			    opt->name, opt->value);
355 			return(-1);
356 		}
357 		tar_nodir = 1;
358 	}
359 	return(0);
360 }
361 
362 
363 /*
364  * tar_rd()
365  *	extract the values out of block already determined to be a tar header.
366  *	store the values in the ARCHD parameter.
367  * Return:
368  *	0
369  */
370 
371 int
372 tar_rd(ARCHD *arcn, char *buf)
373 {
374 	HD_TAR *hd;
375 	char *pt;
376 
377 	/*
378 	 * we only get proper sized buffers passed to us
379 	 */
380 	if (tar_id(buf, BLKMULT) < 0)
381 		return(-1);
382 	arcn->org_name = arcn->name;
383 	arcn->sb.st_nlink = 1;
384 	arcn->pat = NULL;
385 
386 	/*
387 	 * copy out the name and values in the stat buffer
388 	 */
389 	hd = (HD_TAR *)buf;
390 	arcn->nlen = l_strncpy(arcn->name, hd->name, sizeof(arcn->name) - 1);
391 	arcn->name[arcn->nlen] = '\0';
392 	arcn->sb.st_mode = (mode_t)(asc_ul(hd->mode,sizeof(hd->mode),OCT) &
393 	    0xfff);
394 	arcn->sb.st_uid = (uid_t)asc_ul(hd->uid, sizeof(hd->uid), OCT);
395 	arcn->sb.st_gid = (gid_t)asc_ul(hd->gid, sizeof(hd->gid), OCT);
396 #ifdef NET2_STAT
397 	arcn->sb.st_size = (off_t)asc_ul(hd->size, sizeof(hd->size), OCT);
398 #else
399 	arcn->sb.st_size = (off_t)asc_uqd(hd->size, sizeof(hd->size), OCT);
400 #endif
401 	arcn->sb.st_mtime = (time_t)asc_ul(hd->mtime, sizeof(hd->mtime), OCT);
402 	arcn->sb.st_ctime = arcn->sb.st_atime = arcn->sb.st_mtime;
403 
404 	/*
405 	 * have to look at the last character, it may be a '/' and that is used
406 	 * to encode this as a directory
407 	 */
408 	pt = &(arcn->name[arcn->nlen - 1]);
409 	arcn->pad = 0;
410 	arcn->skip = 0;
411 	switch(hd->linkflag) {
412 	case SYMTYPE:
413 		/*
414 		 * symbolic link, need to get the link name and set the type in
415 		 * the st_mode so -v printing will look correct.
416 		 */
417 		arcn->type = PAX_SLK;
418 		arcn->ln_nlen = l_strncpy(arcn->ln_name, hd->linkname,
419 			sizeof(arcn->ln_name) - 1);
420 		arcn->ln_name[arcn->ln_nlen] = '\0';
421 		arcn->sb.st_mode |= S_IFLNK;
422 		break;
423 	case LNKTYPE:
424 		/*
425 		 * hard link, need to get the link name, set the type in the
426 		 * st_mode and st_nlink so -v printing will look better.
427 		 */
428 		arcn->type = PAX_HLK;
429 		arcn->sb.st_nlink = 2;
430 		arcn->ln_nlen = l_strncpy(arcn->ln_name, hd->linkname,
431 			sizeof(arcn->ln_name) - 1);
432 		arcn->ln_name[arcn->ln_nlen] = '\0';
433 
434 		/*
435 		 * no idea of what type this thing really points at, but
436 		 * we set something for printing only.
437 		 */
438 		arcn->sb.st_mode |= S_IFREG;
439 		break;
440 	case DIRTYPE:
441 		/*
442 		 * It is a directory, set the mode for -v printing
443 		 */
444 		arcn->type = PAX_DIR;
445 		arcn->sb.st_mode |= S_IFDIR;
446 		arcn->sb.st_nlink = 2;
447 		arcn->ln_name[0] = '\0';
448 		arcn->ln_nlen = 0;
449 		break;
450 	case AREGTYPE:
451 	case REGTYPE:
452 	default:
453 		/*
454 		 * If we have a trailing / this is a directory and NOT a file.
455 		 */
456 		arcn->ln_name[0] = '\0';
457 		arcn->ln_nlen = 0;
458 		if (*pt == '/') {
459 			/*
460 			 * it is a directory, set the mode for -v printing
461 			 */
462 			arcn->type = PAX_DIR;
463 			arcn->sb.st_mode |= S_IFDIR;
464 			arcn->sb.st_nlink = 2;
465 		} else {
466 			/*
467 			 * have a file that will be followed by data. Set the
468 			 * skip value to the size field and calculate the size
469 			 * of the padding.
470 			 */
471 			arcn->type = PAX_REG;
472 			arcn->sb.st_mode |= S_IFREG;
473 			arcn->pad = TAR_PAD(arcn->sb.st_size);
474 			arcn->skip = arcn->sb.st_size;
475 		}
476 		break;
477 	}
478 
479 	/*
480 	 * strip off any trailing slash.
481 	 */
482 	if (*pt == '/') {
483 		*pt = '\0';
484 		--arcn->nlen;
485 	}
486 	return(0);
487 }
488 
489 /*
490  * tar_wr()
491  *	write a tar header for the file specified in the ARCHD to the archive.
492  *	Have to check for file types that cannot be stored and file names that
493  *	are too long. Be careful of the term (last arg) to ul_oct, each field
494  *	of tar has it own spec for the termination character(s).
495  *	ASSUMED: space after header in header block is zero filled
496  * Return:
497  *	0 if file has data to be written after the header, 1 if file has NO
498  *	data to write after the header, -1 if archive write failed
499  */
500 
501 int
502 tar_wr(ARCHD *arcn)
503 {
504 	HD_TAR *hd;
505 	int len;
506 	char hdblk[sizeof(HD_TAR)];
507 
508 	/*
509 	 * check for those file system types which tar cannot store
510 	 */
511 	switch(arcn->type) {
512 	case PAX_DIR:
513 		/*
514 		 * user asked that dirs not be written to the archive
515 		 */
516 		if (tar_nodir)
517 			return(1);
518 		break;
519 	case PAX_CHR:
520 		paxwarn(1, "Tar cannot archive a character device %s",
521 		    arcn->org_name);
522 		return(1);
523 	case PAX_BLK:
524 		paxwarn(1, "Tar cannot archive a block device %s", arcn->org_name);
525 		return(1);
526 	case PAX_SCK:
527 		paxwarn(1, "Tar cannot archive a socket %s", arcn->org_name);
528 		return(1);
529 	case PAX_FIF:
530 		paxwarn(1, "Tar cannot archive a fifo %s", arcn->org_name);
531 		return(1);
532 	case PAX_SLK:
533 	case PAX_HLK:
534 	case PAX_HRG:
535 		if (arcn->ln_nlen > sizeof(hd->linkname)) {
536 			paxwarn(1,"Link name too long for tar %s", arcn->ln_name);
537 			return(1);
538 		}
539 		break;
540 	case PAX_REG:
541 	case PAX_CTG:
542 	default:
543 		break;
544 	}
545 
546 	/*
547 	 * check file name len, remember extra char for dirs (the / at the end)
548 	 */
549 	len = arcn->nlen;
550 	if (arcn->type == PAX_DIR)
551 		++len;
552 	if (len >= sizeof(hd->name)) {
553 		paxwarn(1, "File name too long for tar %s", arcn->name);
554 		return(1);
555 	}
556 
557 	/*
558 	 * copy the data out of the ARCHD into the tar header based on the type
559 	 * of the file. Remember many tar readers want the unused fields to be
560 	 * padded with zero. We set the linkflag field (type), the linkname
561 	 * (or zero if not used),the size, and set the padding (if any) to be
562 	 * added after the file data (0 for all other types, as they only have
563 	 * a header)
564 	 */
565 	hd = (HD_TAR *)hdblk;
566 	l_strncpy(hd->name, arcn->name, sizeof(hd->name) - 1);
567 	hd->name[sizeof(hd->name) - 1] = '\0';
568 	arcn->pad = 0;
569 
570 	if (arcn->type == PAX_DIR) {
571 		/*
572 		 * directories are the same as files, except have a filename
573 		 * that ends with a /, we add the slash here. No data follows,
574 		 * dirs, so no pad.
575 		 */
576 		hd->linkflag = AREGTYPE;
577 		memset(hd->linkname, 0, sizeof(hd->linkname));
578 		hd->name[len-1] = '/';
579 		if (ul_oct((u_long)0L, hd->size, sizeof(hd->size), 1))
580 			goto out;
581 	} else if (arcn->type == PAX_SLK) {
582 		/*
583 		 * no data follows this file, so no pad
584 		 */
585 		hd->linkflag = SYMTYPE;
586 		l_strncpy(hd->linkname,arcn->ln_name, sizeof(hd->linkname) - 1);
587 		hd->linkname[sizeof(hd->linkname) - 1] = '\0';
588 		if (ul_oct((u_long)0L, hd->size, sizeof(hd->size), 1))
589 			goto out;
590 	} else if ((arcn->type == PAX_HLK) || (arcn->type == PAX_HRG)) {
591 		/*
592 		 * no data follows this file, so no pad
593 		 */
594 		hd->linkflag = LNKTYPE;
595 		l_strncpy(hd->linkname,arcn->ln_name, sizeof(hd->linkname) - 1);
596 		hd->linkname[sizeof(hd->linkname) - 1] = '\0';
597 		if (ul_oct((u_long)0L, hd->size, sizeof(hd->size), 1))
598 			goto out;
599 	} else {
600 		/*
601 		 * data follows this file, so set the pad
602 		 */
603 		hd->linkflag = AREGTYPE;
604 		memset(hd->linkname, 0, sizeof(hd->linkname));
605 #		ifdef NET2_STAT
606 		if (ul_oct((u_long)arcn->sb.st_size, hd->size,
607 		    sizeof(hd->size), 1)) {
608 #		else
609 		if (uqd_oct((u_quad_t)arcn->sb.st_size, hd->size,
610 		    sizeof(hd->size), 1)) {
611 #		endif
612 			paxwarn(1,"File is too large for tar %s", arcn->org_name);
613 			return(1);
614 		}
615 		arcn->pad = TAR_PAD(arcn->sb.st_size);
616 	}
617 
618 	/*
619 	 * copy those fields that are independent of the type
620 	 */
621 	if (ul_oct((u_long)arcn->sb.st_mode, hd->mode, sizeof(hd->mode), 0) ||
622 	    ul_oct((u_long)arcn->sb.st_uid, hd->uid, sizeof(hd->uid), 0) ||
623 	    ul_oct((u_long)arcn->sb.st_gid, hd->gid, sizeof(hd->gid), 0) ||
624 	    ul_oct((u_long)arcn->sb.st_mtime, hd->mtime, sizeof(hd->mtime), 1))
625 		goto out;
626 
627 	/*
628 	 * calculate and add the checksum, then write the header. A return of
629 	 * 0 tells the caller to now write the file data, 1 says no data needs
630 	 * to be written
631 	 */
632 	if (ul_oct(tar_chksm(hdblk, sizeof(HD_TAR)), hd->chksum,
633 	    sizeof(hd->chksum), 3))
634 		goto out;
635 	if (wr_rdbuf(hdblk, sizeof(HD_TAR)) < 0)
636 		return(-1);
637 	if (wr_skip((off_t)(BLKMULT - sizeof(HD_TAR))) < 0)
638 		return(-1);
639 	if ((arcn->type == PAX_CTG) || (arcn->type == PAX_REG))
640 		return(0);
641 	return(1);
642 
643     out:
644 	/*
645 	 * header field is out of range
646 	 */
647 	paxwarn(1, "Tar header field is too small for %s", arcn->org_name);
648 	return(1);
649 }
650 
651 /*
652  * Routines for POSIX ustar
653  */
654 
655 /*
656  * ustar_strd()
657  *	initialization for ustar read
658  * Return:
659  *	0 if ok, -1 otherwise
660  */
661 
662 int
663 ustar_strd(void)
664 {
665 	if ((usrtb_start() < 0) || (grptb_start() < 0))
666 		return(-1);
667 	return(0);
668 }
669 
670 /*
671  * ustar_stwr()
672  *	initialization for ustar write
673  * Return:
674  *	0 if ok, -1 otherwise
675  */
676 
677 int
678 ustar_stwr(void)
679 {
680 	if ((uidtb_start() < 0) || (gidtb_start() < 0))
681 		return(-1);
682 	return(0);
683 }
684 
685 /*
686  * ustar_id()
687  *	determine if a block given to us is a valid ustar header. We have to
688  *	be on the lookout for those pesky blocks of all zero's
689  * Return:
690  *	0 if a ustar header, -1 otherwise
691  */
692 
693 int
694 ustar_id(char *blk, int size)
695 {
696 	HD_USTAR *hd;
697 
698 	if (size < BLKMULT)
699 		return(-1);
700 	hd = (HD_USTAR *)blk;
701 
702 	/*
703 	 * check for block of zero's first, a simple and fast test then check
704 	 * ustar magic cookie. We should use TMAGLEN, but some USTAR archive
705 	 * programs are fouled up and create archives missing the \0. Last we
706 	 * check the checksum. If ok we have to assume it is a valid header.
707 	 */
708 	if (hd->name[0] == '\0')
709 		return(-1);
710 	if (strncmp(hd->magic, TMAGIC, TMAGLEN - 1) != 0)
711 		return(-1);
712 	if (asc_ul(hd->chksum,sizeof(hd->chksum),OCT) != tar_chksm(blk,BLKMULT))
713 		return(-1);
714 	return(0);
715 }
716 
717 /*
718  * ustar_rd()
719  *	extract the values out of block already determined to be a ustar header.
720  *	store the values in the ARCHD parameter.
721  * Return:
722  *	0
723  */
724 
725 int
726 ustar_rd(ARCHD *arcn, char *buf)
727 {
728 	HD_USTAR *hd;
729 	char *dest;
730 	int cnt = 0;
731 	dev_t devmajor;
732 	dev_t devminor;
733 
734 	/*
735 	 * we only get proper sized buffers
736 	 */
737 	if (ustar_id(buf, BLKMULT) < 0)
738 		return(-1);
739 	arcn->org_name = arcn->name;
740 	arcn->sb.st_nlink = 1;
741 	arcn->pat = NULL;
742 	arcn->nlen = 0;
743 	hd = (HD_USTAR *)buf;
744 
745 	/*
746 	 * see if the filename is split into two parts. if, so joint the parts.
747 	 * we copy the prefix first and add a / between the prefix and name.
748 	 */
749 	dest = arcn->name;
750 	if (*(hd->prefix) != '\0') {
751 		cnt = l_strncpy(dest, hd->prefix, sizeof(arcn->name) - 2);
752 		dest += cnt;
753 		*dest++ = '/';
754 		cnt++;
755 	}
756 	arcn->nlen = cnt + l_strncpy(dest, hd->name, sizeof(arcn->name) - cnt);
757 	arcn->name[arcn->nlen] = '\0';
758 
759 	/*
760 	 * follow the spec to the letter. we should only have mode bits, strip
761 	 * off all other crud we may be passed.
762 	 */
763 	arcn->sb.st_mode = (mode_t)(asc_ul(hd->mode, sizeof(hd->mode), OCT) &
764 	    0xfff);
765 #ifdef NET2_STAT
766 	arcn->sb.st_size = (off_t)asc_ul(hd->size, sizeof(hd->size), OCT);
767 #else
768 	arcn->sb.st_size = (off_t)asc_uqd(hd->size, sizeof(hd->size), OCT);
769 #endif
770 	arcn->sb.st_mtime = (time_t)asc_ul(hd->mtime, sizeof(hd->mtime), OCT);
771 	arcn->sb.st_ctime = arcn->sb.st_atime = arcn->sb.st_mtime;
772 
773 	/*
774 	 * If we can find the ascii names for gname and uname in the password
775 	 * and group files we will use the uid's and gid they bind. Otherwise
776 	 * we use the uid and gid values stored in the header. (This is what
777 	 * the POSIX spec wants).
778 	 */
779 	hd->gname[sizeof(hd->gname) - 1] = '\0';
780 	if (gid_name(hd->gname, &(arcn->sb.st_gid)) < 0)
781 		arcn->sb.st_gid = (gid_t)asc_ul(hd->gid, sizeof(hd->gid), OCT);
782 	hd->uname[sizeof(hd->uname) - 1] = '\0';
783 	if (uid_name(hd->uname, &(arcn->sb.st_uid)) < 0)
784 		arcn->sb.st_uid = (uid_t)asc_ul(hd->uid, sizeof(hd->uid), OCT);
785 
786 	/*
787 	 * set the defaults, these may be changed depending on the file type
788 	 */
789 	arcn->ln_name[0] = '\0';
790 	arcn->ln_nlen = 0;
791 	arcn->pad = 0;
792 	arcn->skip = 0;
793 	arcn->sb.st_rdev = (dev_t)0;
794 
795 	/*
796 	 * set the mode and PAX type according to the typeflag in the header
797 	 */
798 	switch(hd->typeflag) {
799 	case FIFOTYPE:
800 		arcn->type = PAX_FIF;
801 		arcn->sb.st_mode |= S_IFIFO;
802 		break;
803 	case DIRTYPE:
804 		arcn->type = PAX_DIR;
805 		arcn->sb.st_mode |= S_IFDIR;
806 		arcn->sb.st_nlink = 2;
807 
808 		/*
809 		 * Some programs that create ustar archives append a '/'
810 		 * to the pathname for directories. This clearly violates
811 		 * ustar specs, but we will silently strip it off anyway.
812 		 */
813 		if (arcn->name[arcn->nlen - 1] == '/')
814 			arcn->name[--arcn->nlen] = '\0';
815 		break;
816 	case BLKTYPE:
817 	case CHRTYPE:
818 		/*
819 		 * this type requires the rdev field to be set.
820 		 */
821 		if (hd->typeflag == BLKTYPE) {
822 			arcn->type = PAX_BLK;
823 			arcn->sb.st_mode |= S_IFBLK;
824 		} else {
825 			arcn->type = PAX_CHR;
826 			arcn->sb.st_mode |= S_IFCHR;
827 		}
828 		devmajor = (dev_t)asc_ul(hd->devmajor,sizeof(hd->devmajor),OCT);
829 		devminor = (dev_t)asc_ul(hd->devminor,sizeof(hd->devminor),OCT);
830 		arcn->sb.st_rdev = TODEV(devmajor, devminor);
831 		break;
832 	case SYMTYPE:
833 	case LNKTYPE:
834 		if (hd->typeflag == SYMTYPE) {
835 			arcn->type = PAX_SLK;
836 			arcn->sb.st_mode |= S_IFLNK;
837 		} else {
838 			arcn->type = PAX_HLK;
839 			/*
840 			 * so printing looks better
841 			 */
842 			arcn->sb.st_mode |= S_IFREG;
843 			arcn->sb.st_nlink = 2;
844 		}
845 		/*
846 		 * copy the link name
847 		 */
848 		arcn->ln_nlen = l_strncpy(arcn->ln_name, hd->linkname,
849 			sizeof(arcn->ln_name) - 1);
850 		arcn->ln_name[arcn->ln_nlen] = '\0';
851 		break;
852 	case CONTTYPE:
853 	case AREGTYPE:
854 	case REGTYPE:
855 	default:
856 		/*
857 		 * these types have file data that follows. Set the skip and
858 		 * pad fields.
859 		 */
860 		arcn->type = PAX_REG;
861 		arcn->pad = TAR_PAD(arcn->sb.st_size);
862 		arcn->skip = arcn->sb.st_size;
863 		arcn->sb.st_mode |= S_IFREG;
864 		break;
865 	}
866 	return(0);
867 }
868 
869 /*
870  * ustar_wr()
871  *	write a ustar header for the file specified in the ARCHD to the archive
872  *	Have to check for file types that cannot be stored and file names that
873  *	are too long. Be careful of the term (last arg) to ul_oct, we only use
874  *	'\0' for the termination character (this is different than picky tar)
875  *	ASSUMED: space after header in header block is zero filled
876  * Return:
877  *	0 if file has data to be written after the header, 1 if file has NO
878  *	data to write after the header, -1 if archive write failed
879  */
880 
881 int
882 ustar_wr(ARCHD *arcn)
883 {
884 	HD_USTAR *hd;
885 	char *pt;
886 	char hdblk[sizeof(HD_USTAR)];
887 
888 	/*
889 	 * check for those file system types ustar cannot store
890 	 */
891 	if (arcn->type == PAX_SCK) {
892 		paxwarn(1, "Ustar cannot archive a socket %s", arcn->org_name);
893 		return(1);
894 	}
895 
896 	/*
897 	 * check the length of the linkname
898 	 */
899 	if (((arcn->type == PAX_SLK) || (arcn->type == PAX_HLK) ||
900 	    (arcn->type == PAX_HRG)) && (arcn->ln_nlen >= sizeof(hd->linkname))){
901 		paxwarn(1, "Link name too long for ustar %s", arcn->ln_name);
902 		return(1);
903 	}
904 
905 	/*
906 	 * split the path name into prefix and name fields (if needed). if
907 	 * pt != arcn->name, the name has to be split
908 	 */
909 	if ((pt = name_split(arcn->name, arcn->nlen)) == NULL) {
910 		paxwarn(1, "File name too long for ustar %s", arcn->name);
911 		return(1);
912 	}
913 	hd = (HD_USTAR *)hdblk;
914 	arcn->pad = 0L;
915 
916 	/*
917 	 * split the name, or zero out the prefix
918 	 */
919 	if (pt != arcn->name) {
920 		/*
921 		 * name was split, pt points at the / where the split is to
922 		 * occur, we remove the / and copy the first part to the prefix
923 		 */
924 		*pt = '\0';
925 		l_strncpy(hd->prefix, arcn->name, sizeof(hd->prefix) - 1);
926 		*pt++ = '/';
927 	} else
928 		memset(hd->prefix, 0, sizeof(hd->prefix));
929 
930 	/*
931 	 * copy the name part. this may be the whole path or the part after
932 	 * the prefix
933 	 */
934 	l_strncpy(hd->name, pt, sizeof(hd->name) - 1);
935 	hd->name[sizeof(hd->name) - 1] = '\0';
936 
937 	/*
938 	 * set the fields in the header that are type dependent
939 	 */
940 	switch(arcn->type) {
941 	case PAX_DIR:
942 		hd->typeflag = DIRTYPE;
943 		memset(hd->linkname, 0, sizeof(hd->linkname));
944 		memset(hd->devmajor, 0, sizeof(hd->devmajor));
945 		memset(hd->devminor, 0, sizeof(hd->devminor));
946 		if (ul_oct((u_long)0L, hd->size, sizeof(hd->size), 3))
947 			goto out;
948 		break;
949 	case PAX_CHR:
950 	case PAX_BLK:
951 		if (arcn->type == PAX_CHR)
952 			hd->typeflag = CHRTYPE;
953 		else
954 			hd->typeflag = BLKTYPE;
955 		memset(hd->linkname, 0, sizeof(hd->linkname));
956 		if (ul_oct((u_long)MAJOR(arcn->sb.st_rdev), hd->devmajor,
957 		   sizeof(hd->devmajor), 3) ||
958 		   ul_oct((u_long)MINOR(arcn->sb.st_rdev), hd->devminor,
959 		   sizeof(hd->devminor), 3) ||
960 		   ul_oct((u_long)0L, hd->size, sizeof(hd->size), 3))
961 			goto out;
962 		break;
963 	case PAX_FIF:
964 		hd->typeflag = FIFOTYPE;
965 		memset(hd->linkname, 0, sizeof(hd->linkname));
966 		memset(hd->devmajor, 0, sizeof(hd->devmajor));
967 		memset(hd->devminor, 0, sizeof(hd->devminor));
968 		if (ul_oct((u_long)0L, hd->size, sizeof(hd->size), 3))
969 			goto out;
970 		break;
971 	case PAX_SLK:
972 	case PAX_HLK:
973 	case PAX_HRG:
974 		if (arcn->type == PAX_SLK)
975 			hd->typeflag = SYMTYPE;
976 		else
977 			hd->typeflag = LNKTYPE;
978 		l_strncpy(hd->linkname,arcn->ln_name, sizeof(hd->linkname) - 1);
979 		hd->linkname[sizeof(hd->linkname) - 1] = '\0';
980 		memset(hd->devmajor, 0, sizeof(hd->devmajor));
981 		memset(hd->devminor, 0, sizeof(hd->devminor));
982 		if (ul_oct((u_long)0L, hd->size, sizeof(hd->size), 3))
983 			goto out;
984 		break;
985 	case PAX_REG:
986 	case PAX_CTG:
987 	default:
988 		/*
989 		 * file data with this type, set the padding
990 		 */
991 		if (arcn->type == PAX_CTG)
992 			hd->typeflag = CONTTYPE;
993 		else
994 			hd->typeflag = REGTYPE;
995 		memset(hd->linkname, 0, sizeof(hd->linkname));
996 		memset(hd->devmajor, 0, sizeof(hd->devmajor));
997 		memset(hd->devminor, 0, sizeof(hd->devminor));
998 		arcn->pad = TAR_PAD(arcn->sb.st_size);
999 #		ifdef NET2_STAT
1000 		if (ul_oct((u_long)arcn->sb.st_size, hd->size,
1001 		    sizeof(hd->size), 3)) {
1002 #		else
1003 		if (uqd_oct((u_quad_t)arcn->sb.st_size, hd->size,
1004 		    sizeof(hd->size), 3)) {
1005 #		endif
1006 			paxwarn(1,"File is too long for ustar %s",arcn->org_name);
1007 			return(1);
1008 		}
1009 		break;
1010 	}
1011 
1012 	l_strncpy(hd->magic, TMAGIC, TMAGLEN);
1013 	l_strncpy(hd->version, TVERSION, TVERSLEN);
1014 
1015 	/*
1016 	 * set the remaining fields. Some versions want all 16 bits of mode
1017 	 * we better humor them (they really do not meet spec though)....
1018 	 */
1019 	if (ul_oct((u_long)arcn->sb.st_mode, hd->mode, sizeof(hd->mode), 3) ||
1020 	    ul_oct((u_long)arcn->sb.st_uid, hd->uid, sizeof(hd->uid), 3)  ||
1021 	    ul_oct((u_long)arcn->sb.st_gid, hd->gid, sizeof(hd->gid), 3) ||
1022 	    ul_oct((u_long)arcn->sb.st_mtime,hd->mtime,sizeof(hd->mtime),3))
1023 		goto out;
1024 	l_strncpy(hd->uname,name_uid(arcn->sb.st_uid, 0),sizeof(hd->uname));
1025 	l_strncpy(hd->gname,name_gid(arcn->sb.st_gid, 0),sizeof(hd->gname));
1026 
1027 	/*
1028 	 * calculate and store the checksum write the header to the archive
1029 	 * return 0 tells the caller to now write the file data, 1 says no data
1030 	 * needs to be written
1031 	 */
1032 	if (ul_oct(tar_chksm(hdblk, sizeof(HD_USTAR)), hd->chksum,
1033 	   sizeof(hd->chksum), 3))
1034 		goto out;
1035 	if (wr_rdbuf(hdblk, sizeof(HD_USTAR)) < 0)
1036 		return(-1);
1037 	if (wr_skip((off_t)(BLKMULT - sizeof(HD_USTAR))) < 0)
1038 		return(-1);
1039 	if ((arcn->type == PAX_CTG) || (arcn->type == PAX_REG))
1040 		return(0);
1041 	return(1);
1042 
1043     out:
1044     	/*
1045 	 * header field is out of range
1046 	 */
1047 	paxwarn(1, "Ustar header field is too small for %s", arcn->org_name);
1048 	return(1);
1049 }
1050 
1051 /*
1052  * name_split()
1053  *	see if the name has to be split for storage in a ustar header. We try
1054  *	to fit the entire name in the name field without splitting if we can.
1055  *	The split point is always at a /
1056  * Return
1057  *	character pointer to split point (always the / that is to be removed
1058  *	if the split is not needed, the points is set to the start of the file
1059  *	name (it would violate the spec to split there). A NULL is returned if
1060  *	the file name is too long
1061  */
1062 
1063 static char *
1064 name_split(char *name, int len)
1065 {
1066 	char *start;
1067 
1068 	/*
1069 	 * check to see if the file name is small enough to fit in the name
1070 	 * field. if so just return a pointer to the name.
1071 	 */
1072 	if (len < TNMSZ)
1073 		return(name);
1074 	if (len > (TPFSZ + TNMSZ))
1075 		return(NULL);
1076 
1077 	/*
1078 	 * we start looking at the biggest sized piece that fits in the name
1079 	 * field. We walk forward looking for a slash to split at. The idea is
1080 	 * to find the biggest piece to fit in the name field (or the smallest
1081 	 * prefix we can find)
1082 	 */
1083 	start = name + len - TNMSZ;
1084 	while ((*start != '\0') && (*start != '/'))
1085 		++start;
1086 
1087 	/*
1088 	 * if we hit the end of the string, this name cannot be split, so we
1089 	 * cannot store this file.
1090 	 */
1091 	if (*start == '\0')
1092 		return(NULL);
1093 	len = start - name;
1094 
1095 	/*
1096 	 * NOTE: /str where the length of str == TNMSZ can not be stored under
1097 	 * the p1003.1-1990 spec for ustar. We could force a prefix of / and
1098 	 * the file would then expand on extract to //str. The len == 0 below
1099 	 * makes this special case follow the spec to the letter.
1100 	 */
1101 	if ((len >= TPFSZ) || (len == 0))
1102 		return(NULL);
1103 
1104 	/*
1105 	 * ok have a split point, return it to the caller
1106 	 */
1107 	return(start);
1108 }
1109