1 /* $OpenBSD: ar_subs.c,v 1.32 2008/05/06 06:54:28 henning Exp $ */
2 /* $NetBSD: ar_subs.c,v 1.5 1995/03/21 09:07:06 cgd Exp $ */
5 * Copyright (c) 1992 Keith Muller.
6 * Copyright (c) 1992, 1993
7 * The Regents of the University of California. All rights reserved.
9 * This code is derived from software contributed to Berkeley by
10 * Keith Muller of the University of California, San Diego.
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39 static const char sccsid[] = "@(#)ar_subs.c 8.2 (Berkeley) 4/18/94";
41 static const char rcsid[] = "$OpenBSD: ar_subs.c,v 1.32 2008/05/06 06:54:28 henning Exp $";
45 #include <sys/types.h>
49 #include <sys/param.h>
60 static void wr_archive(ARCHD *, int is_app);
61 static int get_arc(void);
62 static int next_head(ARCHD *);
63 extern sigset_t s_mask;
65 extern size_t strlcpy(char *, const char *, size_t);
68 * Routines which control the overall operation modes of pax as specified by
69 * the user: list, append, read ...
72 static char hdbuf[BLKMULT]; /* space for archive header on read */
73 u_long flcnt; /* number of files processed */
77 * list the contents of an archive which match user supplied pattern(s)
78 * (no pattern matches all).
91 * figure out archive type; pass any format specific options to the
92 * archive option processing routine; call the format init routine. We
93 * also save current time for ls_list() so we do not make a system
94 * call for each file we need to print. If verbose (vflag) start up
95 * the name and group caches.
97 if ((get_arc() < 0) || ((*frmt->options)() < 0) ||
98 ((*frmt->st_rd)() < 0))
101 if (vflag && ((uidtb_start() < 0) || (gidtb_start() < 0)))
107 * step through the archive until the format says it is done
109 while (next_head(arcn) == 0) {
110 if (arcn->type == PAX_GLL || arcn->type == PAX_GLF) {
112 * we need to read, to get the real filename
115 if (!(*frmt->rd_data)(arcn, arcn->type == PAX_GLF
117 (void)rd_skip(cnt + arcn->pad);
122 * check for pattern, and user specified options match.
123 * When all patterns are matched we are done.
125 if ((res = pat_match(arcn)) < 0)
128 if ((res == 0) && (sel_chk(arcn) == 0)) {
130 * pattern resulted in a selected file
132 if (pat_sel(arcn) < 0)
136 * modify the name as requested by the user if name
137 * survives modification, do a listing of the file
139 if ((res = mod_name(arcn)) < 0)
142 ls_list(arcn, now, stdout);
146 * skip to next archive format header using values calculated
147 * by the format header read routine
149 if (rd_skip(arcn->skip + arcn->pad) == 1)
154 * all done, let format have a chance to cleanup, and make sure that
155 * the patterns supplied by the user were all matched
157 (void)(*frmt->end_rd)();
158 (void)sigprocmask(SIG_BLOCK, &s_mask, NULL);
165 * extract the member(s) of an archive as specified by user supplied
166 * pattern(s) (no patterns extracts all members)
182 * figure out archive type; pass any format specific options to the
183 * archive option processing routine; call the format init routine;
184 * start up the directory modification time and access mode database
186 if ((get_arc() < 0) || ((*frmt->options)() < 0) ||
187 ((*frmt->st_rd)() < 0) || (dir_start() < 0))
191 * When we are doing interactive rename, we store the mapping of names
192 * so we can fix up hard links files later in the archive.
194 if (iflag && (name_start() < 0))
200 * step through each entry on the archive until the format read routine
203 while (next_head(arcn) == 0) {
204 if (arcn->type == PAX_GLL || arcn->type == PAX_GLF) {
206 * we need to read, to get the real filename
208 if (!(*frmt->rd_data)(arcn, arcn->type == PAX_GLF
210 (void)rd_skip(cnt + arcn->pad);
215 * check for pattern, and user specified options match. When
216 * all the patterns are matched we are done
218 if ((res = pat_match(arcn)) < 0)
221 if ((res > 0) || (sel_chk(arcn) != 0)) {
223 * file is not selected. skip past any file data and
224 * padding and go back for the next archive member
226 (void)rd_skip(arcn->skip + arcn->pad);
231 * with -u or -D only extract when the archive member is newer
232 * than the file with the same name in the file system (no
233 * test of being the same type is required).
234 * NOTE: this test is done BEFORE name modifications as
235 * specified by pax. this operation can be confusing to the
236 * user who might expect the test to be done on an existing
237 * file AFTER the name mod. In honesty the pax spec is probably
238 * flawed in this respect.
240 if ((uflag || Dflag) && ((lstat(arcn->name, &sb) == 0))) {
241 if (uflag && Dflag) {
242 if ((arcn->sb.st_mtime <= sb.st_mtime) &&
243 (arcn->sb.st_ctime <= sb.st_ctime)) {
244 (void)rd_skip(arcn->skip + arcn->pad);
248 if (arcn->sb.st_ctime <= sb.st_ctime) {
249 (void)rd_skip(arcn->skip + arcn->pad);
252 } else if (arcn->sb.st_mtime <= sb.st_mtime) {
253 (void)rd_skip(arcn->skip + arcn->pad);
259 * this archive member is now been selected. modify the name.
261 if ((pat_sel(arcn) < 0) || ((res = mod_name(arcn)) < 0))
265 * a bad name mod, skip and purge name from link table
268 (void)rd_skip(arcn->skip + arcn->pad);
273 * Non standard -Y and -Z flag. When the existing file is
274 * same age or newer skip
276 if ((Yflag || Zflag) && ((lstat(arcn->name, &sb) == 0))) {
277 if (Yflag && Zflag) {
278 if ((arcn->sb.st_mtime <= sb.st_mtime) &&
279 (arcn->sb.st_ctime <= sb.st_ctime)) {
280 (void)rd_skip(arcn->skip + arcn->pad);
284 if (arcn->sb.st_ctime <= sb.st_ctime) {
285 (void)rd_skip(arcn->skip + arcn->pad);
288 } else if (arcn->sb.st_mtime <= sb.st_mtime) {
289 (void)rd_skip(arcn->skip + arcn->pad);
296 ls_list(arcn, now, listf);
298 (void)safe_print(arcn->name, listf);
304 * if required, chdir around.
306 if ((arcn->pat != NULL) && (arcn->pat->chdname != NULL))
307 if (chdir(arcn->pat->chdname) != 0)
308 syswarn(1, errno, "Cannot chdir to %s",
312 * all ok, extract this member based on type
314 if ((arcn->type != PAX_REG) && (arcn->type != PAX_CTG)) {
316 * process archive members that are not regular files.
317 * throw out padding and any data that might follow the
318 * header (as determined by the format).
320 if ((arcn->type == PAX_HLK) || (arcn->type == PAX_HRG))
321 res = lnk_creat(arcn);
323 res = node_creat(arcn);
325 (void)rd_skip(arcn->skip + arcn->pad);
329 if (vflag && vfpart) {
330 (void)putc('\n', listf);
336 * we have a file with data here. If we can not create it, skip
337 * over the data and purge the name from hard link table
339 if ((fd = file_creat(arcn)) < 0) {
340 (void)rd_skip(arcn->skip + arcn->pad);
345 * extract the file from the archive and skip over padding and
346 * any unprocessed data
348 res = (*frmt->rd_data)(arcn, fd, &cnt);
349 file_close(arcn, fd);
350 if (vflag && vfpart) {
351 (void)putc('\n', listf);
355 (void)rd_skip(cnt + arcn->pad);
359 * if required, chdir around.
361 if ((arcn->pat != NULL) && (arcn->pat->chdname != NULL))
362 if (fchdir(cwdfd) != 0)
364 "Can't fchdir to starting directory");
368 * all done, restore directory modes and times as required; make sure
369 * all patterns supplied by the user were matched; block off signals
370 * to avoid chance for multiple entry into the cleanup code.
372 (void)(*frmt->end_rd)();
373 (void)sigprocmask(SIG_BLOCK, &s_mask, NULL);
381 * Write an archive. used in both creating a new archive and appends on
382 * previously written archive.
386 wr_archive(ARCHD *arcn, int is_app)
397 * if this format supports hard link storage, start up the database
400 if (((hlk = frmt->hlk) == 1) && (lnk_start() < 0))
404 * if this is not append, and there are no files, we do not write a
410 * start up the file traversal code and format specific write
412 if (ftree_start() < 0) {
416 } else if (((*frmt->st_wr)() < 0))
422 * When we are doing interactive rename, we store the mapping of names
423 * so we can fix up hard links files later in the archive.
425 if (iflag && (name_start() < 0))
431 * while there are files to archive, process them one at at time
433 while (next_file(arcn) == 0) {
435 * check if this file meets user specified options match.
437 if (sel_chk(arcn) != 0)
442 * only archive if this file is newer than a file with
443 * the same name that is already stored on the archive
445 if ((res = chk_ftime(arcn)) < 0)
448 ftree_skipped_newer(arcn);
454 * this file is considered selected now. see if this is a hard
455 * link to a file already stored
458 if (hlk && (chk_lnk(arcn) < 0))
461 if ((arcn->type == PAX_REG) || (arcn->type == PAX_HRG) ||
462 (arcn->type == PAX_CTG)) {
464 * we will have to read this file. by opening it now we
465 * can avoid writing a header to the archive for a file
466 * we were later unable to read (we also purge it from
469 if ((fd = open(arcn->org_name, O_RDONLY, 0)) < 0) {
470 syswarn(1,errno, "Unable to open %s to read",
478 * Now modify the name as requested by the user
480 if ((res = mod_name(arcn)) < 0) {
482 * name modification says to skip this file, close the
483 * file and purge link table entry
485 rdfile_close(arcn, &fd);
490 if ((res > 0) || (docrc && (set_crc(arcn, fd) < 0))) {
492 * unable to obtain the crc we need, close the file,
493 * purge link table entry
495 rdfile_close(arcn, &fd);
502 ls_list(arcn, now, listf);
504 (void)safe_print(arcn->name, listf);
511 * looks safe to store the file, have the format specific
512 * routine write routine store the file header on the archive
514 if ((res = (*wrf)(arcn)) < 0) {
515 rdfile_close(arcn, &fd);
521 * format write says no file data needs to be stored
522 * so we are done messing with this file
524 if (vflag && vfpart) {
525 (void)putc('\n', listf);
528 rdfile_close(arcn, &fd);
533 * Add file data to the archive, quit on write error. if we
534 * cannot write the entire file contents to the archive we
535 * must pad the archive to replace the missing file data
536 * (otherwise during an extract the file header for the file
537 * which FOLLOWS this one will not be where we expect it to
540 res = (*frmt->wr_data)(arcn, fd, &cnt);
541 rdfile_close(arcn, &fd);
542 if (vflag && vfpart) {
543 (void)putc('\n', listf);
550 * pad as required, cnt is number of bytes not written
552 if (((cnt > 0) && (wr_skip(cnt) < 0)) ||
553 ((arcn->pad > 0) && (wr_skip(arcn->pad) < 0)))
559 * tell format to write trailer; pad to block boundary; reset directory
560 * mode/access times, and check if all patterns supplied by the user
561 * were matched. block off signals to avoid chance for multiple entry
562 * into the cleanup code
568 (void)sigprocmask(SIG_BLOCK, &s_mask, NULL);
577 * Add file to previously written archive. Archive format specified by the
578 * user must agree with archive. The archive is read first to collect
579 * modification times (if -u) and locate the archive trailer. The archive
580 * is positioned in front of the record with the trailer and wr_archive()
581 * is called to add the new members.
582 * PAX IMPLEMENTATION DETAIL NOTE:
583 * -u is implemented by adding the new members to the end of the archive.
584 * Care is taken so that these do not end up as links to the older
585 * version of the same file already stored in the archive. It is expected
586 * when extraction occurs these newer versions will over-write the older
587 * ones stored "earlier" in the archive (this may be a bad assumption as
588 * it depends on the implementation of the program doing the extraction).
589 * It is really difficult to splice in members without either re-writing
590 * the entire archive (from the point were the old version was), or having
591 * assistance of the format specification in terms of a special update
592 * header that invalidates a previous archive record. The posix spec left
593 * the method used to implement -u unspecified. This pax is able to
594 * over write existing files that it creates.
611 * Do not allow an append operation if the actual archive is of a
612 * different format than the user specified format.
616 if ((orgfrmt != NULL) && (orgfrmt != frmt)) {
617 paxwarn(1, "Cannot mix current archive format %s with %s",
618 frmt->name, orgfrmt->name);
623 * pass the format any options and start up format
625 if (((*frmt->options)() < 0) || ((*frmt->st_rd)() < 0))
629 * if we only are adding members that are newer, we need to save the
630 * mod times for all files we see.
632 if (uflag && (ftime_start() < 0))
636 * some archive formats encode hard links by recording the device and
637 * file serial number (inode) but copy the file anyway (multiple times)
638 * to the archive. When we append, we run the risk that newly added
639 * files may have the same device and inode numbers as those recorded
640 * on the archive but during a previous run. If this happens, when the
641 * archive is extracted we get INCORRECT hard links. We avoid this by
642 * remapping the device numbers so that newly added files will never
643 * use the same device number as one found on the archive. remapping
644 * allows new members to safely have links among themselves. remapping
645 * also avoids problems with file inode (serial number) truncations
646 * when the inode number is larger than storage space in the archive
647 * header. See the remap routines for more details.
649 if ((udev = frmt->udev) && (dev_start() < 0))
653 * reading the archive may take a long time. If verbose tell the user
657 "%s: Reading archive to position at the end...", argv0);
662 * step through the archive until the format says it is done
664 while (next_head(arcn) == 0) {
666 * check if this file meets user specified options.
668 if (sel_chk(arcn) != 0) {
669 if (rd_skip(arcn->skip + arcn->pad) == 1)
676 * see if this is the newest version of this file has
677 * already been seen, if so skip.
679 if ((res = chk_ftime(arcn)) < 0)
682 if (rd_skip(arcn->skip + arcn->pad) == 1)
689 * Store this device number. Device numbers seen during the
690 * read phase of append will cause newly appended files with a
691 * device number seen in the old part of the archive to be
692 * remapped to an unused device number.
694 if ((udev && (add_dev(arcn) < 0)) ||
695 (rd_skip(arcn->skip + arcn->pad) == 1))
700 * done, finish up read and get the number of bytes to back up so we
701 * can add new members. The format might have used the hard link table,
704 tlen = (*frmt->end_rd)();
708 * try to position for write, if this fails quit. if any error occurs,
709 * we will refuse to write
711 if (appnd_start(tlen) < 0)
715 * tell the user we are done reading.
717 if (vflag && vfpart) {
718 (void)fputs("done.\n", listf);
723 * go to the writing phase to add the new members
730 * write a new archive
739 * if we only are adding members that are newer, we need to save the
740 * mod times for all files; set up for writing; pass the format any
741 * options write the archive
743 if ((uflag && (ftime_start() < 0)) || (wr_start() < 0))
745 if ((*frmt->options)() < 0)
748 wr_archive(&archd, 0);
753 * copy files from one part of the file system to another. this does not
754 * use any archive storage. The EFFECT OF THE COPY IS THE SAME as if an
755 * archive was written and then extracted in the destination directory
756 * (except the files are forced to be under the destination directory).
771 char dirbuf[PAXPATHLEN+1];
775 * set up the destination dir path and make sure it is a directory. We
776 * make sure we have a trailing / on the destination
778 dlen = strlcpy(dirbuf, dirptr, sizeof(dirbuf));
779 if (dlen >= sizeof(dirbuf) ||
780 (dlen == sizeof(dirbuf) - 1 && dirbuf[dlen - 1] != '/')) {
781 paxwarn(1, "directory name is too long %s", dirptr);
784 dest_pt = dirbuf + dlen;
785 if (*(dest_pt-1) != '/') {
790 drem = PAXPATHLEN - dlen;
792 if (stat(dirptr, &sb) < 0) {
793 syswarn(1, errno, "Cannot access destination directory %s",
797 if (!S_ISDIR(sb.st_mode)) {
798 paxwarn(1, "Destination is not a directory %s", dirptr);
803 * start up the hard link table; file traversal routines and the
804 * modification time and access mode database
806 if ((lnk_start() < 0) || (ftree_start() < 0) || (dir_start() < 0))
810 * When we are doing interactive rename, we store the mapping of names
811 * so we can fix up hard links files later in the archive.
813 if (iflag && (name_start() < 0))
817 * set up to cp file trees
822 * while there are files to archive, process them
824 while (next_file(arcn) == 0) {
828 * check if this file meets user specified options
830 if (sel_chk(arcn) != 0)
834 * if there is already a file in the destination directory with
835 * the same name and it is newer, skip the one stored on the
837 * NOTE: this test is done BEFORE name modifications as
838 * specified by pax. this can be confusing to the user who
839 * might expect the test to be done on an existing file AFTER
840 * the name mod. In honesty the pax spec is probably flawed in
843 if (uflag || Dflag) {
845 * create the destination name
847 if (strlcpy(dest_pt, arcn->name + (*arcn->name == '/'),
849 paxwarn(1, "Destination pathname too long %s",
855 * if existing file is same age or newer skip
857 res = lstat(dirbuf, &sb);
861 ftree_skipped_newer(arcn);
862 if (uflag && Dflag) {
863 if ((arcn->sb.st_mtime<=sb.st_mtime) &&
864 (arcn->sb.st_ctime<=sb.st_ctime))
867 if (arcn->sb.st_ctime <= sb.st_ctime)
869 } else if (arcn->sb.st_mtime <= sb.st_mtime)
875 * this file is considered selected. See if this is a hard link
876 * to a previous file; modify the name as requested by the
877 * user; set the final destination.
880 if ((chk_lnk(arcn) < 0) || ((res = mod_name(arcn)) < 0))
882 if ((res > 0) || (set_dest(arcn, dirbuf, dlen) < 0)) {
884 * skip file, purge from link table
891 * Non standard -Y and -Z flag. When the existing file is
892 * same age or newer skip
894 if ((Yflag || Zflag) && ((lstat(arcn->name, &sb) == 0))) {
895 if (Yflag && Zflag) {
896 if ((arcn->sb.st_mtime <= sb.st_mtime) &&
897 (arcn->sb.st_ctime <= sb.st_ctime))
900 if (arcn->sb.st_ctime <= sb.st_ctime)
902 } else if (arcn->sb.st_mtime <= sb.st_mtime)
907 (void)safe_print(arcn->name, listf);
913 * try to create a hard link to the src file if requested
914 * but make sure we are not trying to overwrite ourselves.
917 res = cross_lnk(arcn);
919 res = chk_same(arcn);
921 if (vflag && vfpart) {
922 (void)putc('\n', listf);
929 * have to create a new file
931 if ((arcn->type != PAX_REG) && (arcn->type != PAX_CTG)) {
933 * create a link or special file
935 if ((arcn->type == PAX_HLK) || (arcn->type == PAX_HRG))
936 res = lnk_creat(arcn);
938 res = node_creat(arcn);
941 if (vflag && vfpart) {
942 (void)putc('\n', listf);
949 * have to copy a regular file to the destination directory.
950 * first open source file and then create the destination file
952 if ((fdsrc = open(arcn->org_name, O_RDONLY, 0)) < 0) {
953 syswarn(1, errno, "Unable to open %s to read",
958 if ((fddest = file_creat(arcn)) < 0) {
959 rdfile_close(arcn, &fdsrc);
965 * copy source file data to the destination file
967 cp_file(arcn, fdsrc, fddest);
968 file_close(arcn, fddest);
969 rdfile_close(arcn, &fdsrc);
971 if (vflag && vfpart) {
972 (void)putc('\n', listf);
978 * restore directory modes and times as required; make sure all
979 * patterns were selected block off signals to avoid chance for
980 * multiple entry into the cleanup code.
982 (void)sigprocmask(SIG_BLOCK, &s_mask, NULL);
990 * try to find a valid header in the archive. Uses format specific
991 * routines to extract the header and id the trailer. Trailers may be
992 * located within a valid header or in an invalid header (the location
993 * is format specific. The inhead field from the option table tells us
994 * where to look for the trailer).
995 * We keep reading (and resyncing) until we get enough contiguous data
996 * to check for a header. If we cannot find one, we shift by a byte
997 * add a new byte from the archive to the end of the buffer and try again.
998 * If we get a read error, we throw out what we have (as we must have
999 * contiguous data) and start over again.
1000 * ASSUMED: headers fit within a BLKMULT header.
1002 * 0 if we got a header, -1 if we are unable to ever find another one
1003 * (we reached the end of input, or we reached the limit on retries. see
1004 * the specs for rd_wrbuf() for more details)
1008 next_head(ARCHD *arcn)
1015 int in_resync = 0; /* set when we are in resync mode */
1016 int cnt = 0; /* counter for trailer function */
1017 int first = 1; /* on 1st read, EOF isn't premature. */
1020 * set up initial conditions, we want a whole frmt->hsz block as we
1023 res = hsz = frmt->hsz;
1028 * keep looping until we get a contiguous FULL buffer
1029 * (frmt->hsz is the proper size)
1032 if ((ret = rd_wrbuf(hdend, res)) == res)
1036 * If we read 0 bytes (EOF) from an archive when we
1037 * expect to find a header, we have stepped upon
1038 * an archive without the customary block of zeroes
1039 * end marker. It's just stupid to error out on
1040 * them, so exit gracefully.
1042 if (first && ret == 0)
1047 * some kind of archive read problem, try to resync the
1048 * storage device, better give the user the bad news.
1050 if ((ret == 0) || (rd_sync() < 0)) {
1051 paxwarn(1,"Premature end of file on archive read");
1057 "Archive I/O error, cannot continue");
1060 paxwarn(1,"Archive I/O error. Trying to recover.");
1065 * oh well, throw it all out and start over
1072 * ok we have a contiguous buffer of the right size. Call the
1073 * format read routine. If this was not a valid header and this
1074 * format stores trailers outside of the header, call the
1075 * format specific trailer routine to check for a trailer. We
1076 * have to watch out that we do not mis-identify file data or
1077 * block padding as a header or trailer. Format specific
1078 * trailer functions must NOT check for the trailer while we
1079 * are running in resync mode. Some trailer functions may tell
1080 * us that this block cannot contain a valid header either, so
1081 * we then throw out the entire block and start over.
1083 if ((*frmt->rd)(arcn, hdbuf) == 0)
1086 if (!frmt->inhead) {
1088 * this format has trailers outside of valid headers
1090 if ((ret = (*frmt->trail)(arcn,hdbuf,in_resync,&cnt)) == 0){
1092 * valid trailer found, drain input as required
1100 * we are in resync and we were told to throw
1101 * the whole block out because none of the
1102 * bytes in this block can be used to form a
1112 * Brute force section.
1113 * not a valid header. We may be able to find a header yet. So
1114 * we shift over by one byte, and set up to read one byte at a
1115 * time from the archive and place it at the end of the buffer.
1116 * We will keep moving byte at a time until we find a header or
1117 * get a read error and have to start over.
1121 paxwarn(1,"Unable to append, archive header flaw");
1124 paxwarn(1,"Invalid header, starting valid header search.");
1127 memmove(hdbuf, hdbuf+1, shftsz);
1129 hdend = hdbuf + shftsz;
1133 * ok got a valid header, check for trailer if format encodes it in the
1134 * the header. NOTE: the parameters are different than trailer routines
1135 * which encode trailers outside of the header!
1137 if (frmt->inhead && ((*frmt->trail)(arcn,NULL,0,NULL) == 0)) {
1139 * valid trailer found, drain input as required
1151 * Figure out what format an archive is. Handles archive with flaws by
1152 * brute force searches for a legal header in any supported format. The
1153 * format id routines have to be careful to NOT mis-identify a format.
1154 * ASSUMED: headers fit within a BLKMULT header.
1156 * 0 if archive found -1 otherwise
1165 int minhd = BLKMULT;
1170 * find the smallest header size in all archive formats and then set up
1171 * to read the archive.
1173 for (i = 0; ford[i] >= 0; ++i) {
1174 if (fsub[ford[i]].hsz < minhd)
1175 minhd = fsub[ford[i]].hsz;
1185 * fill the buffer with at least the smallest header
1187 i = rd_wrbuf(hdend, res);
1194 * if we cannot recover from a read error quit
1196 if ((i == 0) || (rd_sync() < 0))
1200 * when we get an error none of the data we already
1201 * have can be used to create a legal header (we just
1202 * got an error in the middle), so we throw it all out
1203 * and refill the buffer with fresh data.
1211 paxwarn(1,"Cannot identify format. Searching...");
1217 * we have at least the size of the smallest header in any
1218 * archive format. Look to see if we have a match. The array
1219 * ford[] is used to specify the header id order to reduce the
1220 * chance of incorrectly id'ing a valid header (some formats
1221 * may be subsets of each other and the order would then be
1224 for (i = 0; ford[i] >= 0; ++i) {
1225 if ((*fsub[ford[i]].id)(hdbuf, hdsz) < 0)
1227 frmt = &(fsub[ford[i]]);
1229 * yuck, to avoid slow special case code in the extract
1230 * routines, just push this header back as if it was
1231 * not seen. We have left extra space at start of the
1232 * buffer for this purpose. This is a bit ugly, but
1233 * adding all the special case code is far worse.
1240 * We have a flawed archive, no match. we start searching, but
1241 * we never allow additions to flawed archives
1246 paxwarn(1, "Cannot identify format. Searching...");
1251 * brute force search for a header that we can id.
1252 * we shift through byte at a time. this is slow, but we cannot
1253 * determine the nature of the flaw in the archive in a
1257 memmove(hdbuf, hdbuf+1, hdsz);
1258 res = BLKMULT - hdsz;
1259 hdend = hdbuf + hdsz;
1269 * we cannot find a header, bow, apologize and quit
1271 paxwarn(1, "Sorry, unable to determine archive format.");