diff options
Diffstat (limited to 'bin/pax/buf_subs.c')
| -rw-r--r-- | bin/pax/buf_subs.c | 1022 |
1 files changed, 0 insertions, 1022 deletions
diff --git a/bin/pax/buf_subs.c b/bin/pax/buf_subs.c deleted file mode 100644 index e4b97af..0000000 --- a/bin/pax/buf_subs.c +++ /dev/null @@ -1,1022 +0,0 @@ -/* $NetBSD: buf_subs.c,v 1.29 2018/03/19 03:11:39 msaitoh Exp $ */ - -/*- - * Copyright (c) 1992 Keith Muller. - * Copyright (c) 1992, 1993 - * The Regents of the University of California. All rights reserved. - * - * This code is derived from software contributed to Berkeley by - * Keith Muller of the University of California, San Diego. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * 3. Neither the name of the University nor the names of its contributors - * may be used to endorse or promote products derived from this software - * without specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND - * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE - * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL - * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS - * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) - * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT - * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY - * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF - * SUCH DAMAGE. - */ - -#if HAVE_NBTOOL_CONFIG_H -#include "nbtool_config.h" -#endif - -#include <sys/cdefs.h> -#if !defined(lint) -#if 0 -static char sccsid[] = "@(#)buf_subs.c 8.2 (Berkeley) 4/18/94"; -#else -__RCSID("$NetBSD: buf_subs.c,v 1.29 2018/03/19 03:11:39 msaitoh Exp $"); -#endif -#endif /* not lint */ - -#include <sys/types.h> -#include <sys/time.h> -#include <sys/stat.h> -#include <sys/param.h> -#include <stdio.h> -#include <ctype.h> -#include <errno.h> -#include <unistd.h> -#include <stdlib.h> -#include <string.h> -#include "pax.h" -#include "extern.h" - -/* - * routines which implement archive and file buffering - */ - -#define MINFBSZ 512 /* default block size for hole detect */ -#define MAXFLT 10 /* default media read error limit */ - -/* - * Need to change bufmem to dynamic allocation when the upper - * limit on blocking size is removed (though that will violate pax spec) - * MAXBLK define and tests will also need to be updated. - */ -static char bufmem[MAXBLK+BLKMULT]; /* i/o buffer + pushback id space */ -static char *buf; /* normal start of i/o buffer */ -static char *bufend; /* end or last char in i/o buffer */ -static char *bufpt; /* read/write point in i/o buffer */ -int blksz = MAXBLK; /* block input/output size in bytes */ -int wrblksz; /* user spec output size in bytes */ -int maxflt = MAXFLT; /* MAX consecutive media errors */ -int rdblksz; /* first read blksize (tapes only) */ -off_t wrlimit; /* # of bytes written per archive vol */ -off_t wrcnt; /* # of bytes written on current vol */ -off_t rdcnt; /* # of bytes read on current vol */ - -/* - * wr_start() - * set up the buffering system to operate in a write mode - * Return: - * 0 if ok, -1 if the user specified write block size violates pax spec - */ - -int -wr_start(void) -{ - buf = &(bufmem[BLKMULT]); - /* - * Check to make sure the write block size meets pax specs. If the user - * does not specify a blocksize, we use the format default blocksize. - * We must be picky on writes, so we do not allow the user to create an - * archive that might be hard to read elsewhere. If all ok, we then - * open the first archive volume - */ - if (!wrblksz) - wrblksz = frmt->bsz; - if (wrblksz > MAXBLK) { - tty_warn(1, "Write block size of %d too large, maximum is: %d", - wrblksz, MAXBLK); - return -1; - } - if (wrblksz % BLKMULT) { - tty_warn(1, "Write block size of %d is not a %d byte multiple", - wrblksz, BLKMULT); - return -1; - } - - /* - * we only allow wrblksz to be used with all archive operations - */ - blksz = rdblksz = wrblksz; - if ((ar_open(arcname) < 0) && (ar_next() < 0)) - return -1; - wrcnt = 0; - bufend = buf + wrblksz; - bufpt = buf; - return 0; -} - -/* - * rd_start() - * set up buffering system to read an archive - * Return: - * 0 if ok, -1 otherwise - */ - -int -rd_start(void) -{ - /* - * leave space for the header pushback (see get_arc()). If we are - * going to append and user specified a write block size, check it - * right away - */ - buf = &(bufmem[BLKMULT]); - if ((act == APPND) && wrblksz) { - if (wrblksz > MAXBLK) { - tty_warn(1, - "Write block size %d too large, maximum is: %d", - wrblksz, MAXBLK); - return -1; - } - if (wrblksz % BLKMULT) { - tty_warn(1, - "Write block size %d is not a %d byte multiple", - wrblksz, BLKMULT); - return -1; - } - } - - /* - * open the archive - */ - if ((ar_open(arcname) < 0) && (ar_next() < 0)) - return -1; - bufend = buf + rdblksz; - bufpt = bufend; - rdcnt = 0; - return 0; -} - -/* - * cp_start() - * set up buffer system for copying within the file system - */ - -void -cp_start(void) -{ - buf = &(bufmem[BLKMULT]); - rdblksz = blksz = MAXBLK; -} - -/* - * appnd_start() - * Set up the buffering system to append new members to an archive that - * was just read. The last block(s) of an archive may contain a format - * specific trailer. To append a new member, this trailer has to be - * removed from the archive. The first byte of the trailer is replaced by - * the start of the header of the first file added to the archive. The - * format specific end read function tells us how many bytes to move - * backwards in the archive to be positioned BEFORE the trailer. Two - * different positions have to be adjusted, the O.S. file offset (e.g. the - * position of the tape head) and the write point within the data we have - * stored in the read (soon to become write) buffer. We may have to move - * back several records (the number depends on the size of the archive - * record and the size of the format trailer) to read up the record where - * the first byte of the trailer is recorded. Trailers may span (and - * overlap) record boundaries. - * We first calculate which record has the first byte of the trailer. We - * move the OS file offset back to the start of this record and read it - * up. We set the buffer write pointer to be at this byte (the byte where - * the trailer starts). We then move the OS file pointer back to the - * start of this record so a flush of this buffer will replace the record - * in the archive. - * A major problem is rewriting this last record. For archives stored - * on disk files, this is trivial. However, many devices are really picky - * about the conditions under which they will allow a write to occur. - * Often devices restrict the conditions where writes can be made, - * so it may not be feasable to append archives stored on all types of - * devices. - * Return: - * 0 for success, -1 for failure - */ - -int -appnd_start(off_t skcnt) -{ - int res; - off_t cnt; - - if (exit_val != 0) { - tty_warn(0, "Cannot append to an archive that may have flaws."); - return -1; - } - /* - * if the user did not specify a write blocksize, inherit the size used - * in the last archive volume read. (If a is set we still use rdblksz - * until next volume, cannot shift sizes within a single volume). - */ - if (!wrblksz) - wrblksz = blksz = rdblksz; - else - blksz = rdblksz; - - /* - * make sure that this volume allows appends - */ - if (ar_app_ok() < 0) - return -1; - - /* - * Calculate bytes to move back and move in front of record where we - * need to start writing from. Remember we have to add in any padding - * that might be in the buffer after the trailer in the last block. We - * travel skcnt + padding ROUNDED UP to blksize. - */ - skcnt += bufend - bufpt; - if ((cnt = (skcnt/blksz) * blksz) < skcnt) - cnt += blksz; - if (ar_rev((off_t)cnt) < 0) - goto out; - - /* - * We may have gone too far if there is valid data in the block we are - * now in front of, read up the block and position the pointer after - * the valid data. - */ - if ((cnt -= skcnt) > 0) { - /* - * watch out for stupid tape drives. ar_rev() will set rdblksz - * to be real physical blocksize so we must loop until we get - * the old rdblksz (now in blksz). If ar_rev() fouls up the - * determination of the physical block size, we will fail. - */ - bufpt = buf; - bufend = buf + blksz; - while (bufpt < bufend) { - if ((res = ar_read(bufpt, rdblksz)) <= 0) - goto out; - bufpt += res; - } - if (ar_rev((off_t)(bufpt - buf)) < 0) - goto out; - bufpt = buf + cnt; - bufend = buf + blksz; - } else { - /* - * buffer is empty - */ - bufend = buf + blksz; - bufpt = buf; - } - rdblksz = blksz; - rdcnt -= skcnt; - wrcnt = 0; - - /* - * At this point we are ready to write. If the device requires special - * handling to write at a point were previously recorded data resides, - * that is handled in ar_set_wr(). From now on we operate under normal - * ARCHIVE mode (write) conditions - */ - if (ar_set_wr() < 0) - return -1; - act = ARCHIVE; - return 0; - - out: - tty_warn(1, "Unable to rewrite archive trailer, cannot append."); - return -1; -} - -/* - * rd_sync() - * A read error occurred on this archive volume. Resync the buffer and - * try to reset the device (if possible) so we can continue to read. Keep - * trying to do this until we get a valid read, or we reach the limit on - * consecutive read faults (at which point we give up). The user can - * adjust the read error limit through a command line option. - * Returns: - * 0 on success, and -1 on failure - */ - -int -rd_sync(void) -{ - int errcnt = 0; - int res; - - /* - * if the user says bail out on first fault, we are out of here... - */ - if (maxflt == 0) - return -1; - if (act == APPND) { - tty_warn(1, - "Unable to append when there are archive read errors."); - return -1; - } - - /* - * poke at device and try to get past media error - */ - if (ar_rdsync() < 0) { - if (ar_next() < 0) - return -1; - else - rdcnt = 0; - } - - for (;;) { - if ((res = ar_read(buf, blksz)) > 0) { - /* - * All right! got some data, fill that buffer - */ - bufpt = buf; - bufend = buf + res; - rdcnt += res; - return 0; - } - - /* - * Oh well, yet another failed read... - * if error limit reached, ditch. otherwise poke device to move past - * bad media and try again. if media is badly damaged, we ask - * the poor (and upset user at this point) for the next archive - * volume. remember the goal on reads is to get the most we - * can extract out of the archive. - */ - if ((maxflt > 0) && (++errcnt > maxflt)) - tty_warn(0, - "Archive read error limit (%d) reached",maxflt); - else if (ar_rdsync() == 0) - continue; - if (ar_next() < 0) - break; - rdcnt = 0; - errcnt = 0; - } - return -1; -} - -/* - * pback() - * push the data used during the archive id phase back into the I/O - * buffer. This is required as we cannot be sure that the header does NOT - * overlap a block boundary (as in the case we are trying to recover a - * flawed archived). This was not designed to be used for any other - * purpose. (What software engineering, HA!) - * WARNING: do not even THINK of pback greater than BLKMULT, unless the - * pback space is increased. - */ - -void -pback(char *pt, int cnt) -{ - bufpt -= cnt; - memcpy(bufpt, pt, cnt); - return; -} - -/* - * rd_skip() - * skip forward in the archive during an archive read. Used to get quickly - * past file data and padding for files the user did NOT select. - * Return: - * 0 if ok, -1 failure, and 1 when EOF on the archive volume was detected. - */ - -int -rd_skip(off_t skcnt) -{ - off_t res; - off_t cnt; - off_t skipped = 0; - - /* - * consume what data we have in the buffer. If we have to move forward - * 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.... - */ - -void -wr_fin(void) -{ - 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) - */ - -int -wr_rdbuf(char *out, int outcnt) -{ - int cnt; - - /* - * while there is data to 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 - */ - -int -rd_wrbuf(char *in, int cpcnt) -{ - int res; - int cnt; - 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 occurred 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 - */ - -int -wr_skip(off_t skcnt) -{ - 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. - */ - -int -wr_rdfile(ARCHD *arcn, int ifd, off_t *left) -{ - int cnt; - int res = 0; - off_t size = arcn->sb.st_size; - struct stat origsb, sb; - - /* - * by default, remember the previously obtained stat information - * (in arcn->sb) for comparing the mtime after reading. - * if Mflag is set, use the actual mtime instead. - */ - origsb = arcn->sb; - if (Mflag && (fstat(ifd, &origsb) < 0)) - syswarn(1, errno, "Failed stat on %s", arcn->org_name); - - /* - * 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_with_restart(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) - tty_warn(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 (origsb.st_mtime != sb.st_mtime) - tty_warn(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 - */ - -int -rd_wrfile(ARCHD *arcn, int ofd, off_t *left) -{ - int cnt = 0; - off_t size = arcn->sb.st_size; - int res = 0; - 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 (ofd < 0) - sz = PAXPATHLEN+1; - else 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 (ofd >= 0 && 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)) - tty_warn(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. - */ - -void -cp_file(ARCHD *arcn, int fd1, int fd2) -{ - int cnt; - off_t cpcnt = 0L; - int res = 0; - char *fnm = arcn->name; - int no_hole = 0; - int isem = 1; - int rem; - int sz = MINFBSZ; - struct stat sb, origsb; - - /* - * 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; - - /* - * by default, remember the previously obtained stat information - * (in arcn->sb) for comparing the mtime after reading. - * if Mflag is set, use the actual mtime instead. - */ - origsb = arcn->sb; - if (Mflag && (fstat(fd1, &origsb) < 0)) - syswarn(1, errno, "Failed stat on %s", arcn->org_name); - - /* - * 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_with_restart(fd1, buf, blksz)) <= 0) - break; - if (no_hole) - res = xwrite(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) - tty_warn(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 (origsb.st_mtime != sb.st_mtime) - tty_warn(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()). - */ - -int -buf_fill(void) -{ - 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 - * but in case we have not determined yet the format, - * this means that we have a very short file, so we - * are done again. - */ - if (cnt < 0) - break; - if (frmt == NULL || 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. - */ - -int -buf_flush(int bufcnt) -{ - int cnt; - int push = 0; - int totcnt = 0; - - /* - * if we have reached the user specified byte count for each archive - * volume, prompt for the next volume. (The non-standard -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)) { - tty_warn(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; -} |