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>
48 #include <sys/param.h>
59 static void wr_archive(ARCHD *, int is_app);
60 static int get_arc(void);
61 static int next_head(ARCHD *);
62 extern sigset_t s_mask;
65 * Routines which control the overall operation modes of pax as specified by
66 * the user: list, append, read ...
69 static char hdbuf[BLKMULT]; /* space for archive header on read */
70 u_long flcnt; /* number of files processed */
74 * list the contents of an archive which match user supplied pattern(s)
75 * (no pattern matches all).
88 * figure out archive type; pass any format specific options to the
89 * archive option processing routine; call the format init routine. We
90 * also save current time for ls_list() so we do not make a system
91 * call for each file we need to print. If verbose (vflag) start up
92 * the name and group caches.
94 if ((get_arc() < 0) || ((*frmt->options)() < 0) ||
95 ((*frmt->st_rd)() < 0))
98 if (vflag && ((uidtb_start() < 0) || (gidtb_start() < 0)))
104 * step through the archive until the format says it is done
106 while (next_head(arcn) == 0) {
107 if (arcn->type == PAX_GLL || arcn->type == PAX_GLF) {
109 * we need to read, to get the real filename
112 if (!(*frmt->rd_data)(arcn, arcn->type == PAX_GLF
114 (void)rd_skip(cnt + arcn->pad);
119 * check for pattern, and user specified options match.
120 * When all patterns are matched we are done.
122 if ((res = pat_match(arcn)) < 0)
125 if ((res == 0) && (sel_chk(arcn) == 0)) {
127 * pattern resulted in a selected file
129 if (pat_sel(arcn) < 0)
133 * modify the name as requested by the user if name
134 * survives modification, do a listing of the file
136 if ((res = mod_name(arcn)) < 0)
139 ls_list(arcn, now, stdout);
143 * skip to next archive format header using values calculated
144 * by the format header read routine
146 if (rd_skip(arcn->skip + arcn->pad) == 1)
151 * all done, let format have a chance to cleanup, and make sure that
152 * the patterns supplied by the user were all matched
154 (void)(*frmt->end_rd)();
155 (void)sigprocmask(SIG_BLOCK, &s_mask, NULL);
162 * extract the member(s) of an archive as specified by user supplied
163 * pattern(s) (no patterns extracts all members)
179 * figure out archive type; pass any format specific options to the
180 * archive option processing routine; call the format init routine;
181 * start up the directory modification time and access mode database
183 if ((get_arc() < 0) || ((*frmt->options)() < 0) ||
184 ((*frmt->st_rd)() < 0) || (dir_start() < 0))
188 * When we are doing interactive rename, we store the mapping of names
189 * so we can fix up hard links files later in the archive.
191 if (iflag && (name_start() < 0))
197 * step through each entry on the archive until the format read routine
200 while (next_head(arcn) == 0) {
201 if (arcn->type == PAX_GLL || arcn->type == PAX_GLF) {
203 * we need to read, to get the real filename
205 if (!(*frmt->rd_data)(arcn, arcn->type == PAX_GLF
207 (void)rd_skip(cnt + arcn->pad);
212 * check for pattern, and user specified options match. When
213 * all the patterns are matched we are done
215 if ((res = pat_match(arcn)) < 0)
218 if ((res > 0) || (sel_chk(arcn) != 0)) {
220 * file is not selected. skip past any file data and
221 * padding and go back for the next archive member
223 (void)rd_skip(arcn->skip + arcn->pad);
228 * with -u or -D only extract when the archive member is newer
229 * than the file with the same name in the file system (no
230 * test of being the same type is required).
231 * NOTE: this test is done BEFORE name modifications as
232 * specified by pax. this operation can be confusing to the
233 * user who might expect the test to be done on an existing
234 * file AFTER the name mod. In honesty the pax spec is probably
235 * flawed in this respect.
237 if ((uflag || Dflag) && ((lstat(arcn->name, &sb) == 0))) {
238 if (uflag && Dflag) {
239 if ((arcn->sb.st_mtime <= sb.st_mtime) &&
240 (arcn->sb.st_ctime <= sb.st_ctime)) {
241 (void)rd_skip(arcn->skip + arcn->pad);
245 if (arcn->sb.st_ctime <= sb.st_ctime) {
246 (void)rd_skip(arcn->skip + arcn->pad);
249 } else if (arcn->sb.st_mtime <= sb.st_mtime) {
250 (void)rd_skip(arcn->skip + arcn->pad);
256 * this archive member is now been selected. modify the name.
258 if ((pat_sel(arcn) < 0) || ((res = mod_name(arcn)) < 0))
262 * a bad name mod, skip and purge name from link table
265 (void)rd_skip(arcn->skip + arcn->pad);
270 * Non standard -Y and -Z flag. When the existing file is
271 * same age or newer skip
273 if ((Yflag || Zflag) && ((lstat(arcn->name, &sb) == 0))) {
274 if (Yflag && Zflag) {
275 if ((arcn->sb.st_mtime <= sb.st_mtime) &&
276 (arcn->sb.st_ctime <= sb.st_ctime)) {
277 (void)rd_skip(arcn->skip + arcn->pad);
281 if (arcn->sb.st_ctime <= sb.st_ctime) {
282 (void)rd_skip(arcn->skip + arcn->pad);
285 } else if (arcn->sb.st_mtime <= sb.st_mtime) {
286 (void)rd_skip(arcn->skip + arcn->pad);
293 ls_list(arcn, now, listf);
295 (void)safe_print(arcn->name, listf);
301 * if required, chdir around.
303 if ((arcn->pat != NULL) && (arcn->pat->chdname != NULL))
304 if (chdir(arcn->pat->chdname) != 0)
305 syswarn(1, errno, "Cannot chdir to %s",
309 * all ok, extract this member based on type
311 if ((arcn->type != PAX_REG) && (arcn->type != PAX_CTG)) {
313 * process archive members that are not regular files.
314 * throw out padding and any data that might follow the
315 * header (as determined by the format).
317 if ((arcn->type == PAX_HLK) || (arcn->type == PAX_HRG))
318 res = lnk_creat(arcn);
320 res = node_creat(arcn);
322 (void)rd_skip(arcn->skip + arcn->pad);
326 if (vflag && vfpart) {
327 (void)putc('\n', listf);
333 * we have a file with data here. If we can not create it, skip
334 * over the data and purge the name from hard link table
336 if ((fd = file_creat(arcn)) < 0) {
337 (void)rd_skip(arcn->skip + arcn->pad);
342 * extract the file from the archive and skip over padding and
343 * any unprocessed data
345 res = (*frmt->rd_data)(arcn, fd, &cnt);
346 file_close(arcn, fd);
347 if (vflag && vfpart) {
348 (void)putc('\n', listf);
352 (void)rd_skip(cnt + arcn->pad);
356 * if required, chdir around.
358 if ((arcn->pat != NULL) && (arcn->pat->chdname != NULL))
359 if (fchdir(cwdfd) != 0)
361 "Can't fchdir to starting directory");
365 * all done, restore directory modes and times as required; make sure
366 * all patterns supplied by the user were matched; block off signals
367 * to avoid chance for multiple entry into the cleanup code.
369 (void)(*frmt->end_rd)();
370 (void)sigprocmask(SIG_BLOCK, &s_mask, NULL);
378 * Write an archive. used in both creating a new archive and appends on
379 * previously written archive.
383 wr_archive(ARCHD *arcn, int is_app)
394 * if this format supports hard link storage, start up the database
397 if (((hlk = frmt->hlk) == 1) && (lnk_start() < 0))
401 * if this is not append, and there are no files, we do not write a
407 * start up the file traversal code and format specific write
409 if (ftree_start() < 0) {
413 } else if (((*frmt->st_wr)() < 0))
419 * When we are doing interactive rename, we store the mapping of names
420 * so we can fix up hard links files later in the archive.
422 if (iflag && (name_start() < 0))
428 * while there are files to archive, process them one at at time
430 while (next_file(arcn) == 0) {
432 * check if this file meets user specified options match.
434 if (sel_chk(arcn) != 0)
439 * only archive if this file is newer than a file with
440 * the same name that is already stored on the archive
442 if ((res = chk_ftime(arcn)) < 0)
445 ftree_skipped_newer(arcn);
451 * this file is considered selected now. see if this is a hard
452 * link to a file already stored
455 if (hlk && (chk_lnk(arcn) < 0))
458 if ((arcn->type == PAX_REG) || (arcn->type == PAX_HRG) ||
459 (arcn->type == PAX_CTG)) {
461 * we will have to read this file. by opening it now we
462 * can avoid writing a header to the archive for a file
463 * we were later unable to read (we also purge it from
466 if ((fd = open(arcn->org_name, O_RDONLY, 0)) < 0) {
467 syswarn(1,errno, "Unable to open %s to read",
475 * Now modify the name as requested by the user
477 if ((res = mod_name(arcn)) < 0) {
479 * name modification says to skip this file, close the
480 * file and purge link table entry
482 rdfile_close(arcn, &fd);
487 if ((res > 0) || (docrc && (set_crc(arcn, fd) < 0))) {
489 * unable to obtain the crc we need, close the file,
490 * purge link table entry
492 rdfile_close(arcn, &fd);
499 ls_list(arcn, now, listf);
501 (void)safe_print(arcn->name, listf);
508 * looks safe to store the file, have the format specific
509 * routine write routine store the file header on the archive
511 if ((res = (*wrf)(arcn)) < 0) {
512 rdfile_close(arcn, &fd);
518 * format write says no file data needs to be stored
519 * so we are done messing with this file
521 if (vflag && vfpart) {
522 (void)putc('\n', listf);
525 rdfile_close(arcn, &fd);
530 * Add file data to the archive, quit on write error. if we
531 * cannot write the entire file contents to the archive we
532 * must pad the archive to replace the missing file data
533 * (otherwise during an extract the file header for the file
534 * which FOLLOWS this one will not be where we expect it to
537 res = (*frmt->wr_data)(arcn, fd, &cnt);
538 rdfile_close(arcn, &fd);
539 if (vflag && vfpart) {
540 (void)putc('\n', listf);
547 * pad as required, cnt is number of bytes not written
549 if (((cnt > 0) && (wr_skip(cnt) < 0)) ||
550 ((arcn->pad > 0) && (wr_skip(arcn->pad) < 0)))
556 * tell format to write trailer; pad to block boundary; reset directory
557 * mode/access times, and check if all patterns supplied by the user
558 * were matched. block off signals to avoid chance for multiple entry
559 * into the cleanup code
565 (void)sigprocmask(SIG_BLOCK, &s_mask, NULL);
574 * Add file to previously written archive. Archive format specified by the
575 * user must agree with archive. The archive is read first to collect
576 * modification times (if -u) and locate the archive trailer. The archive
577 * is positioned in front of the record with the trailer and wr_archive()
578 * is called to add the new members.
579 * PAX IMPLEMENTATION DETAIL NOTE:
580 * -u is implemented by adding the new members to the end of the archive.
581 * Care is taken so that these do not end up as links to the older
582 * version of the same file already stored in the archive. It is expected
583 * when extraction occurs these newer versions will over-write the older
584 * ones stored "earlier" in the archive (this may be a bad assumption as
585 * it depends on the implementation of the program doing the extraction).
586 * It is really difficult to splice in members without either re-writing
587 * the entire archive (from the point were the old version was), or having
588 * assistance of the format specification in terms of a special update
589 * header that invalidates a previous archive record. The posix spec left
590 * the method used to implement -u unspecified. This pax is able to
591 * over write existing files that it creates.
608 * Do not allow an append operation if the actual archive is of a
609 * different format than the user specified format.
613 if ((orgfrmt != NULL) && (orgfrmt != frmt)) {
614 paxwarn(1, "Cannot mix current archive format %s with %s",
615 frmt->name, orgfrmt->name);
620 * pass the format any options and start up format
622 if (((*frmt->options)() < 0) || ((*frmt->st_rd)() < 0))
626 * if we only are adding members that are newer, we need to save the
627 * mod times for all files we see.
629 if (uflag && (ftime_start() < 0))
633 * some archive formats encode hard links by recording the device and
634 * file serial number (inode) but copy the file anyway (multiple times)
635 * to the archive. When we append, we run the risk that newly added
636 * files may have the same device and inode numbers as those recorded
637 * on the archive but during a previous run. If this happens, when the
638 * archive is extracted we get INCORRECT hard links. We avoid this by
639 * remapping the device numbers so that newly added files will never
640 * use the same device number as one found on the archive. remapping
641 * allows new members to safely have links among themselves. remapping
642 * also avoids problems with file inode (serial number) truncations
643 * when the inode number is larger than storage space in the archive
644 * header. See the remap routines for more details.
646 if ((udev = frmt->udev) && (dev_start() < 0))
650 * reading the archive may take a long time. If verbose tell the user
654 "%s: Reading archive to position at the end...", argv0);
659 * step through the archive until the format says it is done
661 while (next_head(arcn) == 0) {
663 * check if this file meets user specified options.
665 if (sel_chk(arcn) != 0) {
666 if (rd_skip(arcn->skip + arcn->pad) == 1)
673 * see if this is the newest version of this file has
674 * already been seen, if so skip.
676 if ((res = chk_ftime(arcn)) < 0)
679 if (rd_skip(arcn->skip + arcn->pad) == 1)
686 * Store this device number. Device numbers seen during the
687 * read phase of append will cause newly appended files with a
688 * device number seen in the old part of the archive to be
689 * remapped to an unused device number.
691 if ((udev && (add_dev(arcn) < 0)) ||
692 (rd_skip(arcn->skip + arcn->pad) == 1))
697 * done, finish up read and get the number of bytes to back up so we
698 * can add new members. The format might have used the hard link table,
701 tlen = (*frmt->end_rd)();
705 * try to position for write, if this fails quit. if any error occurs,
706 * we will refuse to write
708 if (appnd_start(tlen) < 0)
712 * tell the user we are done reading.
714 if (vflag && vfpart) {
715 (void)fputs("done.\n", listf);
720 * go to the writing phase to add the new members
727 * write a new archive
736 * if we only are adding members that are newer, we need to save the
737 * mod times for all files; set up for writing; pass the format any
738 * options write the archive
740 if ((uflag && (ftime_start() < 0)) || (wr_start() < 0))
742 if ((*frmt->options)() < 0)
745 wr_archive(&archd, 0);
750 * copy files from one part of the file system to another. this does not
751 * use any archive storage. The EFFECT OF THE COPY IS THE SAME as if an
752 * archive was written and then extracted in the destination directory
753 * (except the files are forced to be under the destination directory).
768 char dirbuf[PAXPATHLEN+1];
772 * set up the destination dir path and make sure it is a directory. We
773 * make sure we have a trailing / on the destination
775 dlen = strlcpy(dirbuf, dirptr, sizeof(dirbuf));
776 if (dlen >= sizeof(dirbuf) ||
777 (dlen == sizeof(dirbuf) - 1 && dirbuf[dlen - 1] != '/')) {
778 paxwarn(1, "directory name is too long %s", dirptr);
781 dest_pt = dirbuf + dlen;
782 if (*(dest_pt-1) != '/') {
787 drem = PAXPATHLEN - dlen;
789 if (stat(dirptr, &sb) < 0) {
790 syswarn(1, errno, "Cannot access destination directory %s",
794 if (!S_ISDIR(sb.st_mode)) {
795 paxwarn(1, "Destination is not a directory %s", dirptr);
800 * start up the hard link table; file traversal routines and the
801 * modification time and access mode database
803 if ((lnk_start() < 0) || (ftree_start() < 0) || (dir_start() < 0))
807 * When we are doing interactive rename, we store the mapping of names
808 * so we can fix up hard links files later in the archive.
810 if (iflag && (name_start() < 0))
814 * set up to cp file trees
819 * while there are files to archive, process them
821 while (next_file(arcn) == 0) {
825 * check if this file meets user specified options
827 if (sel_chk(arcn) != 0)
831 * if there is already a file in the destination directory with
832 * the same name and it is newer, skip the one stored on the
834 * NOTE: this test is done BEFORE name modifications as
835 * specified by pax. this can be confusing to the user who
836 * might expect the test to be done on an existing file AFTER
837 * the name mod. In honesty the pax spec is probably flawed in
840 if (uflag || Dflag) {
842 * create the destination name
844 if (strlcpy(dest_pt, arcn->name + (*arcn->name == '/'),
846 paxwarn(1, "Destination pathname too long %s",
852 * if existing file is same age or newer skip
854 res = lstat(dirbuf, &sb);
858 ftree_skipped_newer(arcn);
859 if (uflag && Dflag) {
860 if ((arcn->sb.st_mtime<=sb.st_mtime) &&
861 (arcn->sb.st_ctime<=sb.st_ctime))
864 if (arcn->sb.st_ctime <= sb.st_ctime)
866 } else if (arcn->sb.st_mtime <= sb.st_mtime)
872 * this file is considered selected. See if this is a hard link
873 * to a previous file; modify the name as requested by the
874 * user; set the final destination.
877 if ((chk_lnk(arcn) < 0) || ((res = mod_name(arcn)) < 0))
879 if ((res > 0) || (set_dest(arcn, dirbuf, dlen) < 0)) {
881 * skip file, purge from link table
888 * Non standard -Y and -Z flag. When the existing file is
889 * same age or newer skip
891 if ((Yflag || Zflag) && ((lstat(arcn->name, &sb) == 0))) {
892 if (Yflag && Zflag) {
893 if ((arcn->sb.st_mtime <= sb.st_mtime) &&
894 (arcn->sb.st_ctime <= sb.st_ctime))
897 if (arcn->sb.st_ctime <= sb.st_ctime)
899 } else if (arcn->sb.st_mtime <= sb.st_mtime)
904 (void)safe_print(arcn->name, listf);
910 * try to create a hard link to the src file if requested
911 * but make sure we are not trying to overwrite ourselves.
914 res = cross_lnk(arcn);
916 res = chk_same(arcn);
918 if (vflag && vfpart) {
919 (void)putc('\n', listf);
926 * have to create a new file
928 if ((arcn->type != PAX_REG) && (arcn->type != PAX_CTG)) {
930 * create a link or special file
932 if ((arcn->type == PAX_HLK) || (arcn->type == PAX_HRG))
933 res = lnk_creat(arcn);
935 res = node_creat(arcn);
938 if (vflag && vfpart) {
939 (void)putc('\n', listf);
946 * have to copy a regular file to the destination directory.
947 * first open source file and then create the destination file
949 if ((fdsrc = open(arcn->org_name, O_RDONLY, 0)) < 0) {
950 syswarn(1, errno, "Unable to open %s to read",
955 if ((fddest = file_creat(arcn)) < 0) {
956 rdfile_close(arcn, &fdsrc);
962 * copy source file data to the destination file
964 cp_file(arcn, fdsrc, fddest);
965 file_close(arcn, fddest);
966 rdfile_close(arcn, &fdsrc);
968 if (vflag && vfpart) {
969 (void)putc('\n', listf);
975 * restore directory modes and times as required; make sure all
976 * patterns were selected block off signals to avoid chance for
977 * multiple entry into the cleanup code.
979 (void)sigprocmask(SIG_BLOCK, &s_mask, NULL);
987 * try to find a valid header in the archive. Uses format specific
988 * routines to extract the header and id the trailer. Trailers may be
989 * located within a valid header or in an invalid header (the location
990 * is format specific. The inhead field from the option table tells us
991 * where to look for the trailer).
992 * We keep reading (and resyncing) until we get enough contiguous data
993 * to check for a header. If we cannot find one, we shift by a byte
994 * add a new byte from the archive to the end of the buffer and try again.
995 * If we get a read error, we throw out what we have (as we must have
996 * contiguous data) and start over again.
997 * ASSUMED: headers fit within a BLKMULT header.
999 * 0 if we got a header, -1 if we are unable to ever find another one
1000 * (we reached the end of input, or we reached the limit on retries. see
1001 * the specs for rd_wrbuf() for more details)
1005 next_head(ARCHD *arcn)
1012 int in_resync = 0; /* set when we are in resync mode */
1013 int cnt = 0; /* counter for trailer function */
1014 int first = 1; /* on 1st read, EOF isn't premature. */
1017 * set up initial conditions, we want a whole frmt->hsz block as we
1020 res = hsz = frmt->hsz;
1025 * keep looping until we get a contiguous FULL buffer
1026 * (frmt->hsz is the proper size)
1029 if ((ret = rd_wrbuf(hdend, res)) == res)
1033 * If we read 0 bytes (EOF) from an archive when we
1034 * expect to find a header, we have stepped upon
1035 * an archive without the customary block of zeroes
1036 * end marker. It's just stupid to error out on
1037 * them, so exit gracefully.
1039 if (first && ret == 0)
1044 * some kind of archive read problem, try to resync the
1045 * storage device, better give the user the bad news.
1047 if ((ret == 0) || (rd_sync() < 0)) {
1048 paxwarn(1,"Premature end of file on archive read");
1054 "Archive I/O error, cannot continue");
1057 paxwarn(1,"Archive I/O error. Trying to recover.");
1062 * oh well, throw it all out and start over
1069 * ok we have a contiguous buffer of the right size. Call the
1070 * format read routine. If this was not a valid header and this
1071 * format stores trailers outside of the header, call the
1072 * format specific trailer routine to check for a trailer. We
1073 * have to watch out that we do not mis-identify file data or
1074 * block padding as a header or trailer. Format specific
1075 * trailer functions must NOT check for the trailer while we
1076 * are running in resync mode. Some trailer functions may tell
1077 * us that this block cannot contain a valid header either, so
1078 * we then throw out the entire block and start over.
1080 if ((*frmt->rd)(arcn, hdbuf) == 0)
1083 if (!frmt->inhead) {
1085 * this format has trailers outside of valid headers
1087 if ((ret = (*frmt->trail)(arcn,hdbuf,in_resync,&cnt)) == 0){
1089 * valid trailer found, drain input as required
1097 * we are in resync and we were told to throw
1098 * the whole block out because none of the
1099 * bytes in this block can be used to form a
1109 * Brute force section.
1110 * not a valid header. We may be able to find a header yet. So
1111 * we shift over by one byte, and set up to read one byte at a
1112 * time from the archive and place it at the end of the buffer.
1113 * We will keep moving byte at a time until we find a header or
1114 * get a read error and have to start over.
1118 paxwarn(1,"Unable to append, archive header flaw");
1121 paxwarn(1,"Invalid header, starting valid header search.");
1124 memmove(hdbuf, hdbuf+1, shftsz);
1126 hdend = hdbuf + shftsz;
1130 * ok got a valid header, check for trailer if format encodes it in the
1131 * the header. NOTE: the parameters are different than trailer routines
1132 * which encode trailers outside of the header!
1134 if (frmt->inhead && ((*frmt->trail)(arcn,NULL,0,NULL) == 0)) {
1136 * valid trailer found, drain input as required
1148 * Figure out what format an archive is. Handles archive with flaws by
1149 * brute force searches for a legal header in any supported format. The
1150 * format id routines have to be careful to NOT mis-identify a format.
1151 * ASSUMED: headers fit within a BLKMULT header.
1153 * 0 if archive found -1 otherwise
1162 int minhd = BLKMULT;
1167 * find the smallest header size in all archive formats and then set up
1168 * to read the archive.
1170 for (i = 0; ford[i] >= 0; ++i) {
1171 if (fsub[ford[i]].hsz < minhd)
1172 minhd = fsub[ford[i]].hsz;
1182 * fill the buffer with at least the smallest header
1184 i = rd_wrbuf(hdend, res);
1191 * if we cannot recover from a read error quit
1193 if ((i == 0) || (rd_sync() < 0))
1197 * when we get an error none of the data we already
1198 * have can be used to create a legal header (we just
1199 * got an error in the middle), so we throw it all out
1200 * and refill the buffer with fresh data.
1208 paxwarn(1,"Cannot identify format. Searching...");
1214 * we have at least the size of the smallest header in any
1215 * archive format. Look to see if we have a match. The array
1216 * ford[] is used to specify the header id order to reduce the
1217 * chance of incorrectly id'ing a valid header (some formats
1218 * may be subsets of each other and the order would then be
1221 for (i = 0; ford[i] >= 0; ++i) {
1222 if ((*fsub[ford[i]].id)(hdbuf, hdsz) < 0)
1224 frmt = &(fsub[ford[i]]);
1226 * yuck, to avoid slow special case code in the extract
1227 * routines, just push this header back as if it was
1228 * not seen. We have left extra space at start of the
1229 * buffer for this purpose. This is a bit ugly, but
1230 * adding all the special case code is far worse.
1237 * We have a flawed archive, no match. we start searching, but
1238 * we never allow additions to flawed archives
1243 paxwarn(1, "Cannot identify format. Searching...");
1248 * brute force search for a header that we can id.
1249 * we shift through byte at a time. this is slow, but we cannot
1250 * determine the nature of the flaw in the archive in a
1254 memmove(hdbuf, hdbuf+1, hdsz);
1255 res = BLKMULT - hdsz;
1256 hdend = hdbuf + hdsz;
1266 * we cannot find a header, bow, apologize and quit
1268 paxwarn(1, "Sorry, unable to determine archive format.");