#if __STDC__ -> #ifdef __STDC__ pax_warn() -> paxwarn() sys_warn() -> syswarn() (foo *)NULL -> NULL bcopy -> memmove()/memcpy() bzero -> memset() Typo fixes sprintf() -> snprintf() rindex() -> strrchr() index() -> strchr() sys_errlist[] -> strerror() Obtained from: OpenBSD
1084 lines
28 KiB
C
1084 lines
28 KiB
C
/*-
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* Copyright (c) 1992 Keith Muller.
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* Copyright (c) 1992, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Keith Muller of the University of California, San Diego.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#ifndef lint
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#if 0
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static char sccsid[] = "@(#)buf_subs.c 8.2 (Berkeley) 4/18/94";
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#endif
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static const char rcsid[] =
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"$FreeBSD$";
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#endif /* not lint */
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <errno.h>
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#include <unistd.h>
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#include <stdlib.h>
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#include <string.h>
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#include "pax.h"
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#include "extern.h"
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/*
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* routines which implement archive and file buffering
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*/
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#define MINFBSZ 512 /* default block size for hole detect */
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#define MAXFLT 10 /* default media read error limit */
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/*
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* Need to change bufmem to dynamic allocation when the upper
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* limit on blocking size is removed (though that will violate pax spec)
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* MAXBLK define and tests will also need to be updated.
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*/
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static char bufmem[MAXBLK+BLKMULT]; /* i/o buffer + pushback id space */
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static char *buf; /* normal start of i/o buffer */
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static char *bufend; /* end or last char in i/o buffer */
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static char *bufpt; /* read/write point in i/o buffer */
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int blksz = MAXBLK; /* block input/output size in bytes */
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int wrblksz; /* user spec output size in bytes */
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int maxflt = MAXFLT; /* MAX consecutive media errors */
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int rdblksz; /* first read blksize (tapes only) */
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off_t wrlimit; /* # of bytes written per archive vol */
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off_t wrcnt; /* # of bytes written on current vol */
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off_t rdcnt; /* # of bytes read on current vol */
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/*
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* wr_start()
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* set up the buffering system to operate in a write mode
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* Return:
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* 0 if ok, -1 if the user specified write block size violates pax spec
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*/
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#ifdef __STDC__
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int
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wr_start(void)
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#else
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int
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wr_start()
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#endif
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{
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buf = &(bufmem[BLKMULT]);
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/*
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* Check to make sure the write block size meets pax specs. If the user
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* does not specify a blocksize, we use the format default blocksize.
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* We must be picky on writes, so we do not allow the user to create an
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* archive that might be hard to read elsewhere. If all ok, we then
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* open the first archive volume
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*/
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if (!wrblksz)
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wrblksz = frmt->bsz;
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if (wrblksz > MAXBLK) {
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paxwarn(1, "Write block size of %d too large, maximum is: %d",
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wrblksz, MAXBLK);
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return(-1);
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}
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if (wrblksz % BLKMULT) {
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paxwarn(1, "Write block size of %d is not a %d byte multiple",
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wrblksz, BLKMULT);
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return(-1);
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}
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/*
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* we only allow wrblksz to be used with all archive operations
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*/
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blksz = rdblksz = wrblksz;
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if ((ar_open(arcname) < 0) && (ar_next() < 0))
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return(-1);
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wrcnt = 0;
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bufend = buf + wrblksz;
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bufpt = buf;
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return(0);
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}
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/*
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* rd_start()
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* set up buffering system to read an archive
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* Return:
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* 0 if ok, -1 otherwise
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*/
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#ifdef __STDC__
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int
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rd_start(void)
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#else
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int
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rd_start()
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#endif
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{
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/*
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* leave space for the header pushback (see get_arc()). If we are
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* going to append and user specified a write block size, check it
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* right away
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*/
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buf = &(bufmem[BLKMULT]);
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if ((act == APPND) && wrblksz) {
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if (wrblksz > MAXBLK) {
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paxwarn(1,"Write block size %d too large, maximum is: %d",
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wrblksz, MAXBLK);
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return(-1);
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}
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if (wrblksz % BLKMULT) {
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paxwarn(1, "Write block size %d is not a %d byte multiple",
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wrblksz, BLKMULT);
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return(-1);
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}
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}
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/*
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* open the archive
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*/
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if ((ar_open(arcname) < 0) && (ar_next() < 0))
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return(-1);
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bufend = buf + rdblksz;
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bufpt = bufend;
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rdcnt = 0;
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return(0);
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}
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|
/*
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* cp_start()
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* set up buffer system for copying within the file system
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|
*/
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#ifdef __STDC__
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void
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cp_start(void)
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#else
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void
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cp_start()
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#endif
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{
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buf = &(bufmem[BLKMULT]);
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rdblksz = blksz = MAXBLK;
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}
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/*
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* appnd_start()
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* Set up the buffering system to append new members to an archive that
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* was just read. The last block(s) of an archive may contain a format
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* specific trailer. To append a new member, this trailer has to be
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* removed from the archive. The first byte of the trailer is replaced by
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* the start of the header of the first file added to the archive. The
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* format specific end read function tells us how many bytes to move
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* backwards in the archive to be positioned BEFORE the trailer. Two
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* different postions have to be adjusted, the O.S. file offset (e.g. the
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* position of the tape head) and the write point within the data we have
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* stored in the read (soon to become write) buffer. We may have to move
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* back several records (the number depends on the size of the archive
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* record and the size of the format trailer) to read up the record where
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* the first byte of the trailer is recorded. Trailers may span (and
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* overlap) record boundries.
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* We first calculate which record has the first byte of the trailer. We
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* move the OS file offset back to the start of this record and read it
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* up. We set the buffer write pointer to be at this byte (the byte where
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* the trailer starts). We then move the OS file pointer back to the
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* start of this record so a flush of this buffer will replace the record
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* in the archive.
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* A major problem is rewriting this last record. For archives stored
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* on disk files, this is trival. However, many devices are really picky
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* about the conditions under which they will allow a write to occur.
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* Often devices restrict the conditions where writes can be made writes,
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* so it may not be feasable to append archives stored on all types of
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* devices.
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* Return:
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* 0 for success, -1 for failure
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*/
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#ifdef __STDC__
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int
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appnd_start(off_t skcnt)
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#else
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int
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appnd_start(skcnt)
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off_t skcnt;
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#endif
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{
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register int res;
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off_t cnt;
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if (exit_val != 0) {
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paxwarn(0, "Cannot append to an archive that may have flaws.");
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return(-1);
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}
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/*
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* if the user did not specify a write blocksize, inherit the size used
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* in the last archive volume read. (If a is set we still use rdblksz
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* until next volume, cannot shift sizes within a single volume).
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*/
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if (!wrblksz)
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wrblksz = blksz = rdblksz;
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else
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blksz = rdblksz;
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/*
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* make sure that this volume allows appends
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*/
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if (ar_app_ok() < 0)
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return(-1);
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/*
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* Calculate bytes to move back and move in front of record where we
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* need to start writing from. Remember we have to add in any padding
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* that might be in the buffer after the trailer in the last block. We
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* travel skcnt + padding ROUNDED UP to blksize.
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*/
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skcnt += bufend - bufpt;
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if ((cnt = (skcnt/blksz) * blksz) < skcnt)
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cnt += blksz;
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if (ar_rev((off_t)cnt) < 0)
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goto out;
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/*
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* We may have gone too far if there is valid data in the block we are
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* now in front of, read up the block and position the pointer after
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* the valid data.
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*/
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if ((cnt -= skcnt) > 0) {
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/*
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* watch out for stupid tape drives. ar_rev() will set rdblksz
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* to be real physical blocksize so we must loop until we get
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* the old rdblksz (now in blksz). If ar_rev() fouls up the
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* determination of the physical block size, we will fail.
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*/
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bufpt = buf;
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bufend = buf + blksz;
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while (bufpt < bufend) {
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if ((res = ar_read(bufpt, rdblksz)) <= 0)
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goto out;
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bufpt += res;
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}
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if (ar_rev((off_t)(bufpt - buf)) < 0)
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goto out;
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bufpt = buf + cnt;
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bufend = buf + blksz;
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} else {
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/*
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* buffer is empty
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*/
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bufend = buf + blksz;
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bufpt = buf;
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}
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rdblksz = blksz;
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rdcnt -= skcnt;
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wrcnt = 0;
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/*
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* At this point we are ready to write. If the device requires special
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* handling to write at a point were previously recorded data resides,
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* that is handled in ar_set_wr(). From now on we operate under normal
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* ARCHIVE mode (write) conditions
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*/
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if (ar_set_wr() < 0)
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return(-1);
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act = ARCHIVE;
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return(0);
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out:
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paxwarn(1, "Unable to rewrite archive trailer, cannot append.");
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return(-1);
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}
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/*
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* rd_sync()
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* A read error occurred on this archive volume. Resync the buffer and
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* try to reset the device (if possible) so we can continue to read. Keep
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* trying to do this until we get a valid read, or we reach the limit on
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* consecutive read faults (at which point we give up). The user can
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* adjust the read error limit through a command line option.
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* Returns:
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* 0 on success, and -1 on failure
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|
*/
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#ifdef __STDC__
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int
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rd_sync(void)
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#else
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int
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rd_sync()
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#endif
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{
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register int errcnt = 0;
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register int res;
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/*
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* if the user says bail out on first fault, we are out of here...
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*/
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if (maxflt == 0)
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return(-1);
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if (act == APPND) {
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paxwarn(1, "Unable to append when there are archive read errors.");
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return(-1);
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}
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|
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|
/*
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* poke at device and try to get past media error
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*/
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if (ar_rdsync() < 0) {
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if (ar_next() < 0)
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return(-1);
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else
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rdcnt = 0;
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}
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for (;;) {
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if ((res = ar_read(buf, blksz)) > 0) {
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/*
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* All right! got some data, fill that buffer
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|
*/
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bufpt = buf;
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bufend = buf + res;
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rdcnt += res;
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return(0);
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}
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|
/*
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* Oh well, yet another failed read...
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* if error limit reached, ditch. o.w. poke device to move past
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* bad media and try again. if media is badly damaged, we ask
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* the poor (and upset user at this point) for the next archive
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* volume. remember the goal on reads is to get the most we
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* can extract out of the archive.
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*/
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if ((maxflt > 0) && (++errcnt > maxflt))
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paxwarn(0,"Archive read error limit (%d) reached",maxflt);
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else if (ar_rdsync() == 0)
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continue;
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if (ar_next() < 0)
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break;
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|
rdcnt = 0;
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|
errcnt = 0;
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}
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return(-1);
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}
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|
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|
/*
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* pback()
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* push the data used during the archive id phase back into the I/O
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* buffer. This is required as we cannot be sure that the header does NOT
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* overlap a block boundry (as in the case we are trying to recover a
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|
* flawed archived). This was not designed to be used for any other
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|
* purpose. (What software engineering, HA!)
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* WARNING: do not even THINK of pback greater than BLKMULT, unless the
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* pback space is increased.
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|
*/
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|
#ifdef __STDC__
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|
void
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pback(char *pt, int cnt)
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#else
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|
void
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pback(pt, cnt)
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char *pt;
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|
int cnt;
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#endif
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|
{
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bufpt -= cnt;
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memcpy(bufpt, pt, cnt);
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return;
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}
|
|
|
|
/*
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|
* rd_skip()
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|
* skip foward in the archive during a archive read. Used to get quickly
|
|
* past file data and padding for files the user did NOT select.
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|
* Return:
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|
* 0 if ok, -1 failure, and 1 when EOF on the archive volume was detected.
|
|
*/
|
|
|
|
#ifdef __STDC__
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|
int
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rd_skip(off_t skcnt)
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|
#else
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|
int
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|
rd_skip(skcnt)
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|
off_t skcnt;
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|
#endif
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|
{
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|
off_t res;
|
|
off_t cnt;
|
|
off_t skipped = 0;
|
|
|
|
/*
|
|
* consume what data we have in the buffer. If we have to move foward
|
|
* whole records, we call the low level skip function to see if we can
|
|
* move within the archive without doing the expensive reads on data we
|
|
* do not want.
|
|
*/
|
|
if (skcnt == 0)
|
|
return(0);
|
|
res = MIN((bufend - bufpt), skcnt);
|
|
bufpt += res;
|
|
skcnt -= res;
|
|
|
|
/*
|
|
* if skcnt is now 0, then no additional i/o is needed
|
|
*/
|
|
if (skcnt == 0)
|
|
return(0);
|
|
|
|
/*
|
|
* We have to read more, calculate complete and partial record reads
|
|
* based on rdblksz. we skip over "cnt" complete records
|
|
*/
|
|
res = skcnt%rdblksz;
|
|
cnt = (skcnt/rdblksz) * rdblksz;
|
|
|
|
/*
|
|
* if the skip fails, we will have to resync. ar_fow will tell us
|
|
* how much it can skip over. We will have to read the rest.
|
|
*/
|
|
if (ar_fow(cnt, &skipped) < 0)
|
|
return(-1);
|
|
res += cnt - skipped;
|
|
rdcnt += skipped;
|
|
|
|
/*
|
|
* what is left we have to read (which may be the whole thing if
|
|
* ar_fow() told us the device can only read to skip records);
|
|
*/
|
|
while (res > 0L) {
|
|
cnt = bufend - bufpt;
|
|
/*
|
|
* if the read fails, we will have to resync
|
|
*/
|
|
if ((cnt <= 0) && ((cnt = buf_fill()) < 0))
|
|
return(-1);
|
|
if (cnt == 0)
|
|
return(1);
|
|
cnt = MIN(cnt, res);
|
|
bufpt += cnt;
|
|
res -= cnt;
|
|
}
|
|
return(0);
|
|
}
|
|
|
|
/*
|
|
* wr_fin()
|
|
* flush out any data (and pad if required) the last block. We always pad
|
|
* with zero (even though we do not have to). Padding with 0 makes it a
|
|
* lot easier to recover if the archive is damaged. zero paddding SHOULD
|
|
* BE a requirement....
|
|
*/
|
|
|
|
#ifdef __STDC__
|
|
void
|
|
wr_fin(void)
|
|
#else
|
|
void
|
|
wr_fin()
|
|
#endif
|
|
{
|
|
if (bufpt > buf) {
|
|
memset(bufpt, 0, bufend - bufpt);
|
|
bufpt = bufend;
|
|
(void)buf_flush(blksz);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* wr_rdbuf()
|
|
* fill the write buffer from data passed to it in a buffer (usually used
|
|
* by format specific write routines to pass a file header). On failure we
|
|
* punt. We do not allow the user to continue to write flawed archives.
|
|
* We assume these headers are not very large (the memory copy we use is
|
|
* a bit expensive).
|
|
* Return:
|
|
* 0 if buffer was filled ok, -1 o.w. (buffer flush failure)
|
|
*/
|
|
|
|
#ifdef __STDC__
|
|
int
|
|
wr_rdbuf(register char *out, register int outcnt)
|
|
#else
|
|
int
|
|
wr_rdbuf(out, outcnt)
|
|
register char *out;
|
|
register int outcnt;
|
|
#endif
|
|
{
|
|
register int cnt;
|
|
|
|
/*
|
|
* while there is data to copy copy into the write buffer. when the
|
|
* write buffer fills, flush it to the archive and continue
|
|
*/
|
|
while (outcnt > 0) {
|
|
cnt = bufend - bufpt;
|
|
if ((cnt <= 0) && ((cnt = buf_flush(blksz)) < 0))
|
|
return(-1);
|
|
/*
|
|
* only move what we have space for
|
|
*/
|
|
cnt = MIN(cnt, outcnt);
|
|
memcpy(bufpt, out, cnt);
|
|
bufpt += cnt;
|
|
out += cnt;
|
|
outcnt -= cnt;
|
|
}
|
|
return(0);
|
|
}
|
|
|
|
/*
|
|
* rd_wrbuf()
|
|
* copy from the read buffer into a supplied buffer a specified number of
|
|
* bytes. If the read buffer is empty fill it and continue to copy.
|
|
* usually used to obtain a file header for processing by a format
|
|
* specific read routine.
|
|
* Return
|
|
* number of bytes copied to the buffer, 0 indicates EOF on archive volume,
|
|
* -1 is a read error
|
|
*/
|
|
|
|
#ifdef __STDC__
|
|
int
|
|
rd_wrbuf(register char *in, register int cpcnt)
|
|
#else
|
|
int
|
|
rd_wrbuf(in, cpcnt)
|
|
register char *in;
|
|
register int cpcnt;
|
|
#endif
|
|
{
|
|
register int res;
|
|
register int cnt;
|
|
register int incnt = cpcnt;
|
|
|
|
/*
|
|
* loop until we fill the buffer with the requested number of bytes
|
|
*/
|
|
while (incnt > 0) {
|
|
cnt = bufend - bufpt;
|
|
if ((cnt <= 0) && ((cnt = buf_fill()) <= 0)) {
|
|
/*
|
|
* read error, return what we got (or the error if
|
|
* no data was copied). The caller must know that an
|
|
* error occured and has the best knowledge what to
|
|
* do with it
|
|
*/
|
|
if ((res = cpcnt - incnt) > 0)
|
|
return(res);
|
|
return(cnt);
|
|
}
|
|
|
|
/*
|
|
* calculate how much data to copy based on whats left and
|
|
* state of buffer
|
|
*/
|
|
cnt = MIN(cnt, incnt);
|
|
memcpy(in, bufpt, cnt);
|
|
bufpt += cnt;
|
|
incnt -= cnt;
|
|
in += cnt;
|
|
}
|
|
return(cpcnt);
|
|
}
|
|
|
|
/*
|
|
* wr_skip()
|
|
* skip forward during a write. In other words add padding to the file.
|
|
* we add zero filled padding as it makes flawed archives much easier to
|
|
* recover from. the caller tells us how many bytes of padding to add
|
|
* This routine was not designed to add HUGE amount of padding, just small
|
|
* amounts (a few 512 byte blocks at most)
|
|
* Return:
|
|
* 0 if ok, -1 if there was a buf_flush failure
|
|
*/
|
|
|
|
#ifdef __STDC__
|
|
int
|
|
wr_skip(off_t skcnt)
|
|
#else
|
|
int
|
|
wr_skip(skcnt)
|
|
off_t skcnt;
|
|
#endif
|
|
{
|
|
register int cnt;
|
|
|
|
/*
|
|
* loop while there is more padding to add
|
|
*/
|
|
while (skcnt > 0L) {
|
|
cnt = bufend - bufpt;
|
|
if ((cnt <= 0) && ((cnt = buf_flush(blksz)) < 0))
|
|
return(-1);
|
|
cnt = MIN(cnt, skcnt);
|
|
memset(bufpt, 0, cnt);
|
|
bufpt += cnt;
|
|
skcnt -= cnt;
|
|
}
|
|
return(0);
|
|
}
|
|
|
|
/*
|
|
* wr_rdfile()
|
|
* fill write buffer with the contents of a file. We are passed an open
|
|
* file descriptor to the file an the archive structure that describes the
|
|
* file we are storing. The variable "left" is modified to contain the
|
|
* number of bytes of the file we were NOT able to write to the archive.
|
|
* it is important that we always write EXACTLY the number of bytes that
|
|
* the format specific write routine told us to. The file can also get
|
|
* bigger, so reading to the end of file would create an improper archive,
|
|
* we just detect this case and warn the user. We never create a bad
|
|
* archive if we can avoid it. Of course trying to archive files that are
|
|
* active is asking for trouble. It we fail, we pass back how much we
|
|
* could NOT copy and let the caller deal with it.
|
|
* Return:
|
|
* 0 ok, -1 if archive write failure. a short read of the file returns a
|
|
* 0, but "left" is set to be greater than zero.
|
|
*/
|
|
|
|
#ifdef __STDC__
|
|
int
|
|
wr_rdfile(ARCHD *arcn, int ifd, off_t *left)
|
|
#else
|
|
int
|
|
wr_rdfile(arcn, ifd, left)
|
|
ARCHD *arcn;
|
|
int ifd;
|
|
off_t *left;
|
|
#endif
|
|
{
|
|
register int cnt;
|
|
register int res = 0;
|
|
register off_t size = arcn->sb.st_size;
|
|
struct stat sb;
|
|
|
|
/*
|
|
* while there are more bytes to write
|
|
*/
|
|
while (size > 0L) {
|
|
cnt = bufend - bufpt;
|
|
if ((cnt <= 0) && ((cnt = buf_flush(blksz)) < 0)) {
|
|
*left = size;
|
|
return(-1);
|
|
}
|
|
cnt = MIN(cnt, size);
|
|
if ((res = read(ifd, bufpt, cnt)) <= 0)
|
|
break;
|
|
size -= res;
|
|
bufpt += res;
|
|
}
|
|
|
|
/*
|
|
* better check the file did not change during this operation
|
|
* or the file read failed.
|
|
*/
|
|
if (res < 0)
|
|
syswarn(1, errno, "Read fault on %s", arcn->org_name);
|
|
else if (size != 0L)
|
|
paxwarn(1, "File changed size during read %s", arcn->org_name);
|
|
else if (fstat(ifd, &sb) < 0)
|
|
syswarn(1, errno, "Failed stat on %s", arcn->org_name);
|
|
else if (arcn->sb.st_mtime != sb.st_mtime)
|
|
paxwarn(1, "File %s was modified during copy to archive",
|
|
arcn->org_name);
|
|
*left = size;
|
|
return(0);
|
|
}
|
|
|
|
/*
|
|
* rd_wrfile()
|
|
* extract the contents of a file from the archive. If we are unable to
|
|
* extract the entire file (due to failure to write the file) we return
|
|
* the numbers of bytes we did NOT process. This way the caller knows how
|
|
* many bytes to skip past to find the next archive header. If the failure
|
|
* was due to an archive read, we will catch that when we try to skip. If
|
|
* the format supplies a file data crc value, we calculate the actual crc
|
|
* so that it can be compared to the value stored in the header
|
|
* NOTE:
|
|
* We call a special function to write the file. This function attempts to
|
|
* restore file holes (blocks of zeros) into the file. When files are
|
|
* sparse this saves space, and is a LOT faster. For non sparse files
|
|
* the performance hit is small. As of this writing, no archive supports
|
|
* information on where the file holes are.
|
|
* Return:
|
|
* 0 ok, -1 if archive read failure. if we cannot write the entire file,
|
|
* we return a 0 but "left" is set to be the amount unwritten
|
|
*/
|
|
|
|
#ifdef __STDC__
|
|
int
|
|
rd_wrfile(ARCHD *arcn, int ofd, off_t *left)
|
|
#else
|
|
int
|
|
rd_wrfile(arcn, ofd, left)
|
|
ARCHD *arcn;
|
|
int ofd;
|
|
off_t *left;
|
|
#endif
|
|
{
|
|
register int cnt = 0;
|
|
register off_t size = arcn->sb.st_size;
|
|
register int res = 0;
|
|
register char *fnm = arcn->name;
|
|
int isem = 1;
|
|
int rem;
|
|
int sz = MINFBSZ;
|
|
struct stat sb;
|
|
u_long crc = 0L;
|
|
|
|
/*
|
|
* pass the blocksize of the file being written to the write routine,
|
|
* if the size is zero, use the default MINFBSZ
|
|
*/
|
|
if (fstat(ofd, &sb) == 0) {
|
|
if (sb.st_blksize > 0)
|
|
sz = (int)sb.st_blksize;
|
|
} else
|
|
syswarn(0,errno,"Unable to obtain block size for file %s",fnm);
|
|
rem = sz;
|
|
*left = 0L;
|
|
|
|
/*
|
|
* Copy the archive to the file the number of bytes specified. We have
|
|
* to assume that we want to recover file holes as none of the archive
|
|
* formats can record the location of file holes.
|
|
*/
|
|
while (size > 0L) {
|
|
cnt = bufend - bufpt;
|
|
/*
|
|
* if we get a read error, we do not want to skip, as we may
|
|
* miss a header, so we do not set left, but if we get a write
|
|
* error, we do want to skip over the unprocessed data.
|
|
*/
|
|
if ((cnt <= 0) && ((cnt = buf_fill()) <= 0))
|
|
break;
|
|
cnt = MIN(cnt, size);
|
|
if ((res = file_write(ofd,bufpt,cnt,&rem,&isem,sz,fnm)) <= 0) {
|
|
*left = size;
|
|
break;
|
|
}
|
|
|
|
if (docrc) {
|
|
/*
|
|
* update the actual crc value
|
|
*/
|
|
cnt = res;
|
|
while (--cnt >= 0)
|
|
crc += *bufpt++ & 0xff;
|
|
} else
|
|
bufpt += res;
|
|
size -= res;
|
|
}
|
|
|
|
/*
|
|
* if the last block has a file hole (all zero), we must make sure this
|
|
* gets updated in the file. We force the last block of zeros to be
|
|
* written. just closing with the file offset moved forward may not put
|
|
* a hole at the end of the file.
|
|
*/
|
|
if (isem && (arcn->sb.st_size > 0L))
|
|
file_flush(ofd, fnm, isem);
|
|
|
|
/*
|
|
* if we failed from archive read, we do not want to skip
|
|
*/
|
|
if ((size > 0L) && (*left == 0L))
|
|
return(-1);
|
|
|
|
/*
|
|
* some formats record a crc on file data. If so, then we compare the
|
|
* calculated crc to the crc stored in the archive
|
|
*/
|
|
if (docrc && (size == 0L) && (arcn->crc != crc))
|
|
paxwarn(1,"Actual crc does not match expected crc %s",arcn->name);
|
|
return(0);
|
|
}
|
|
|
|
/*
|
|
* cp_file()
|
|
* copy the contents of one file to another. used during -rw phase of pax
|
|
* just as in rd_wrfile() we use a special write function to write the
|
|
* destination file so we can properly copy files with holes.
|
|
*/
|
|
|
|
#ifdef __STDC__
|
|
void
|
|
cp_file(ARCHD *arcn, int fd1, int fd2)
|
|
#else
|
|
void
|
|
cp_file(arcn, fd1, fd2)
|
|
ARCHD *arcn;
|
|
int fd1;
|
|
int fd2;
|
|
#endif
|
|
{
|
|
register int cnt;
|
|
register off_t cpcnt = 0L;
|
|
register int res = 0;
|
|
register char *fnm = arcn->name;
|
|
register int no_hole = 0;
|
|
int isem = 1;
|
|
int rem;
|
|
int sz = MINFBSZ;
|
|
struct stat sb;
|
|
|
|
/*
|
|
* check for holes in the source file. If none, we will use regular
|
|
* write instead of file write.
|
|
*/
|
|
if (((off_t)(arcn->sb.st_blocks * BLKMULT)) >= arcn->sb.st_size)
|
|
++no_hole;
|
|
|
|
/*
|
|
* pass the blocksize of the file being written to the write routine,
|
|
* if the size is zero, use the default MINFBSZ
|
|
*/
|
|
if (fstat(fd2, &sb) == 0) {
|
|
if (sb.st_blksize > 0)
|
|
sz = sb.st_blksize;
|
|
} else
|
|
syswarn(0,errno,"Unable to obtain block size for file %s",fnm);
|
|
rem = sz;
|
|
|
|
/*
|
|
* read the source file and copy to destination file until EOF
|
|
*/
|
|
for(;;) {
|
|
if ((cnt = read(fd1, buf, blksz)) <= 0)
|
|
break;
|
|
if (no_hole)
|
|
res = write(fd2, buf, cnt);
|
|
else
|
|
res = file_write(fd2, buf, cnt, &rem, &isem, sz, fnm);
|
|
if (res != cnt)
|
|
break;
|
|
cpcnt += cnt;
|
|
}
|
|
|
|
/*
|
|
* check to make sure the copy is valid.
|
|
*/
|
|
if (res < 0)
|
|
syswarn(1, errno, "Failed write during copy of %s to %s",
|
|
arcn->org_name, arcn->name);
|
|
else if (cpcnt != arcn->sb.st_size)
|
|
paxwarn(1, "File %s changed size during copy to %s",
|
|
arcn->org_name, arcn->name);
|
|
else if (fstat(fd1, &sb) < 0)
|
|
syswarn(1, errno, "Failed stat of %s", arcn->org_name);
|
|
else if (arcn->sb.st_mtime != sb.st_mtime)
|
|
paxwarn(1, "File %s was modified during copy to %s",
|
|
arcn->org_name, arcn->name);
|
|
|
|
/*
|
|
* if the last block has a file hole (all zero), we must make sure this
|
|
* gets updated in the file. We force the last block of zeros to be
|
|
* written. just closing with the file offset moved forward may not put
|
|
* a hole at the end of the file.
|
|
*/
|
|
if (!no_hole && isem && (arcn->sb.st_size > 0L))
|
|
file_flush(fd2, fnm, isem);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* buf_fill()
|
|
* fill the read buffer with the next record (or what we can get) from
|
|
* the archive volume.
|
|
* Return:
|
|
* Number of bytes of data in the read buffer, -1 for read error, and
|
|
* 0 when finished (user specified termination in ar_next()).
|
|
*/
|
|
|
|
#ifdef __STDC__
|
|
int
|
|
buf_fill(void)
|
|
#else
|
|
int
|
|
buf_fill()
|
|
#endif
|
|
{
|
|
register int cnt;
|
|
static int fini = 0;
|
|
|
|
if (fini)
|
|
return(0);
|
|
|
|
for(;;) {
|
|
/*
|
|
* try to fill the buffer. on error the next archive volume is
|
|
* opened and we try again.
|
|
*/
|
|
if ((cnt = ar_read(buf, blksz)) > 0) {
|
|
bufpt = buf;
|
|
bufend = buf + cnt;
|
|
rdcnt += cnt;
|
|
return(cnt);
|
|
}
|
|
|
|
/*
|
|
* errors require resync, EOF goes to next archive
|
|
*/
|
|
if (cnt < 0)
|
|
break;
|
|
if (ar_next() < 0) {
|
|
fini = 1;
|
|
return(0);
|
|
}
|
|
rdcnt = 0;
|
|
}
|
|
exit_val = 1;
|
|
return(-1);
|
|
}
|
|
|
|
/*
|
|
* buf_flush()
|
|
* force the write buffer to the archive. We are passed the number of
|
|
* bytes in the buffer at the point of the flush. When we change archives
|
|
* the record size might change. (either larger or smaller).
|
|
* Return:
|
|
* 0 if all is ok, -1 when a write error occurs.
|
|
*/
|
|
|
|
#ifdef __STDC__
|
|
int
|
|
buf_flush(register int bufcnt)
|
|
#else
|
|
int
|
|
buf_flush(bufcnt)
|
|
register int bufcnt;
|
|
#endif
|
|
{
|
|
register int cnt;
|
|
register int push = 0;
|
|
register int totcnt = 0;
|
|
|
|
/*
|
|
* if we have reached the user specified byte count for each archive
|
|
* volume, prompt for the next volume. (The non-standrad -R flag).
|
|
* NOTE: If the wrlimit is smaller than wrcnt, we will always write
|
|
* at least one record. We always round limit UP to next blocksize.
|
|
*/
|
|
if ((wrlimit > 0) && (wrcnt > wrlimit)) {
|
|
paxwarn(0, "User specified archive volume byte limit reached.");
|
|
if (ar_next() < 0) {
|
|
wrcnt = 0;
|
|
exit_val = 1;
|
|
return(-1);
|
|
}
|
|
wrcnt = 0;
|
|
|
|
/*
|
|
* The new archive volume might have changed the size of the
|
|
* write blocksize. if so we figure out if we need to write
|
|
* (one or more times), or if there is now free space left in
|
|
* the buffer (it is no longer full). bufcnt has the number of
|
|
* bytes in the buffer, (the blocksize, at the point we were
|
|
* CALLED). Push has the amount of "extra" data in the buffer
|
|
* if the block size has shrunk from a volume change.
|
|
*/
|
|
bufend = buf + blksz;
|
|
if (blksz > bufcnt)
|
|
return(0);
|
|
if (blksz < bufcnt)
|
|
push = bufcnt - blksz;
|
|
}
|
|
|
|
/*
|
|
* We have enough data to write at least one archive block
|
|
*/
|
|
for (;;) {
|
|
/*
|
|
* write a block and check if it all went out ok
|
|
*/
|
|
cnt = ar_write(buf, blksz);
|
|
if (cnt == blksz) {
|
|
/*
|
|
* the write went ok
|
|
*/
|
|
wrcnt += cnt;
|
|
totcnt += cnt;
|
|
if (push > 0) {
|
|
/* we have extra data to push to the front.
|
|
* check for more than 1 block of push, and if
|
|
* so we loop back to write again
|
|
*/
|
|
memcpy(buf, bufend, push);
|
|
bufpt = buf + push;
|
|
if (push >= blksz) {
|
|
push -= blksz;
|
|
continue;
|
|
}
|
|
} else
|
|
bufpt = buf;
|
|
return(totcnt);
|
|
} else if (cnt > 0) {
|
|
/*
|
|
* Oh drat we got a partial write!
|
|
* if format doesnt care about alignment let it go,
|
|
* we warned the user in ar_write().... but this means
|
|
* the last record on this volume violates pax spec....
|
|
*/
|
|
totcnt += cnt;
|
|
wrcnt += cnt;
|
|
bufpt = buf + cnt;
|
|
cnt = bufcnt - cnt;
|
|
memcpy(buf, bufpt, cnt);
|
|
bufpt = buf + cnt;
|
|
if (!frmt->blkalgn || ((cnt % frmt->blkalgn) == 0))
|
|
return(totcnt);
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* All done, go to next archive
|
|
*/
|
|
wrcnt = 0;
|
|
if (ar_next() < 0)
|
|
break;
|
|
|
|
/*
|
|
* The new archive volume might also have changed the block
|
|
* size. if so, figure out if we have too much or too little
|
|
* data for using the new block size
|
|
*/
|
|
bufend = buf + blksz;
|
|
if (blksz > bufcnt)
|
|
return(0);
|
|
if (blksz < bufcnt)
|
|
push = bufcnt - blksz;
|
|
}
|
|
|
|
/*
|
|
* write failed, stop pax. we must not create a bad archive!
|
|
*/
|
|
exit_val = 1;
|
|
return(-1);
|
|
}
|