941 lines
25 KiB
C
941 lines
25 KiB
C
/*-
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* SPDX-License-Identifier: BSD-3-Clause
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*
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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. 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[] = "@(#)file_subs.c 8.1 (Berkeley) 5/31/93";
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#endif
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#endif /* not lint */
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#include <sys/cdefs.h>
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#include <sys/types.h>
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#include <sys/time.h>
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#include <sys/stat.h>
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#include <unistd.h>
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#include <fcntl.h>
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#include <string.h>
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#include <stdio.h>
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#include <errno.h>
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#include <sys/uio.h>
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#include "pax.h"
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#include "options.h"
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#include "extern.h"
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static int
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mk_link(char *,struct stat *,char *, int);
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/*
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* routines that deal with file operations such as: creating, removing;
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* and setting access modes, uid/gid and times of files
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*/
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#define FILEBITS (S_ISVTX | S_IRWXU | S_IRWXG | S_IRWXO)
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#define SETBITS (S_ISUID | S_ISGID)
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#define ABITS (FILEBITS | SETBITS)
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/*
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* file_creat()
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* Create and open a file.
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* Return:
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* file descriptor or -1 for failure
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*/
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int
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file_creat(ARCHD *arcn)
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{
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int fd = -1;
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mode_t file_mode;
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int oerrno;
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/*
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* assume file doesn't exist, so just try to create it, most times this
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* works. We have to take special handling when the file does exist. To
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* detect this, we use O_EXCL. For example when trying to create a
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* file and a character device or fifo exists with the same name, we
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* can accidentally open the device by mistake (or block waiting to
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* open). If we find that the open has failed, then spend the effort
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* to figure out why. This strategy was found to have better average
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* performance in common use than checking the file (and the path)
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* first with lstat.
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*/
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file_mode = arcn->sb.st_mode & FILEBITS;
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if ((fd = open(arcn->name, O_WRONLY | O_CREAT | O_TRUNC | O_EXCL,
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file_mode)) >= 0)
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return(fd);
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/*
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* the file seems to exist. First we try to get rid of it (found to be
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* the second most common failure when traced). If this fails, only
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* then we go to the expense to check and create the path to the file
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*/
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if (unlnk_exist(arcn->name, arcn->type) != 0)
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return(-1);
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for (;;) {
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/*
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* try to open it again, if this fails, check all the nodes in
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* the path and give it a final try. if chk_path() finds that
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* it cannot fix anything, we will skip the last attempt
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*/
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if ((fd = open(arcn->name, O_WRONLY | O_CREAT | O_TRUNC,
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file_mode)) >= 0)
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break;
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oerrno = errno;
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if (nodirs || chk_path(arcn->name,arcn->sb.st_uid,arcn->sb.st_gid) < 0) {
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syswarn(1, oerrno, "Unable to create %s", arcn->name);
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return(-1);
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}
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}
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return(fd);
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}
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/*
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* file_close()
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* Close file descriptor to a file just created by pax. Sets modes,
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* ownership and times as required.
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* Return:
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* 0 for success, -1 for failure
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*/
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void
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file_close(ARCHD *arcn, int fd)
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{
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int res = 0;
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if (fd < 0)
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return;
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if (close(fd) < 0)
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syswarn(0, errno, "Unable to close file descriptor on %s",
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arcn->name);
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/*
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* set owner/groups first as this may strip off mode bits we want
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* then set file permission modes. Then set file access and
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* modification times.
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*/
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if (pids)
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res = set_ids(arcn->name, arcn->sb.st_uid, arcn->sb.st_gid);
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/*
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* IMPORTANT SECURITY NOTE:
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* if not preserving mode or we cannot set uid/gid, then PROHIBIT
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* set uid/gid bits
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*/
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if (!pmode || res)
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arcn->sb.st_mode &= ~(SETBITS);
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if (pmode)
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set_pmode(arcn->name, arcn->sb.st_mode);
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if (patime || pmtime)
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set_ftime(arcn->name, arcn->sb.st_mtime, arcn->sb.st_atime, 0);
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}
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/*
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* lnk_creat()
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* Create a hard link to arcn->ln_name from arcn->name. arcn->ln_name
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* must exist;
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* Return:
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* 0 if ok, -1 otherwise
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*/
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int
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lnk_creat(ARCHD *arcn)
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{
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struct stat sb;
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/*
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* we may be running as root, so we have to be sure that link target
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* is not a directory, so we lstat and check
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*/
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if (lstat(arcn->ln_name, &sb) < 0) {
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syswarn(1,errno,"Unable to link to %s from %s", arcn->ln_name,
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arcn->name);
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return(-1);
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}
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if (S_ISDIR(sb.st_mode)) {
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paxwarn(1, "A hard link to the directory %s is not allowed",
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arcn->ln_name);
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return(-1);
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}
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return(mk_link(arcn->ln_name, &sb, arcn->name, 0));
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}
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/*
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* cross_lnk()
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* Create a hard link to arcn->org_name from arcn->name. Only used in copy
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* with the -l flag. No warning or error if this does not succeed (we will
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* then just create the file)
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* Return:
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* 1 if copy() should try to create this file node
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* 0 if cross_lnk() ok, -1 for fatal flaw (like linking to self).
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*/
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int
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cross_lnk(ARCHD *arcn)
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{
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/*
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* try to make a link to original file (-l flag in copy mode). make sure
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* we do not try to link to directories in case we are running as root
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* (and it might succeed).
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*/
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if (arcn->type == PAX_DIR)
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return(1);
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return(mk_link(arcn->org_name, &(arcn->sb), arcn->name, 1));
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}
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/*
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* chk_same()
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* In copy mode if we are not trying to make hard links between the src
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* and destinations, make sure we are not going to overwrite ourselves by
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* accident. This slows things down a little, but we have to protect all
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* those people who make typing errors.
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* Return:
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* 1 the target does not exist, go ahead and copy
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* 0 skip it file exists (-k) or may be the same as source file
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*/
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int
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chk_same(ARCHD *arcn)
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{
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struct stat sb;
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/*
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* if file does not exist, return. if file exists and -k, skip it
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* quietly
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*/
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if (lstat(arcn->name, &sb) < 0)
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return(1);
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if (kflag)
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return(0);
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/*
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* better make sure the user does not have src == dest by mistake
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*/
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if ((arcn->sb.st_dev == sb.st_dev) && (arcn->sb.st_ino == sb.st_ino)) {
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paxwarn(1, "Unable to copy %s, file would overwrite itself",
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arcn->name);
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return(0);
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}
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return(1);
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}
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/*
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* mk_link()
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* try to make a hard link between two files. if ign set, we do not
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* complain.
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* Return:
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* 0 if successful (or we are done with this file but no error, such as
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* finding the from file exists and the user has set -k).
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* 1 when ign was set to indicates we could not make the link but we
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* should try to copy/extract the file as that might work (and is an
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* allowed option). -1 an error occurred.
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*/
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static int
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mk_link(char *to, struct stat *to_sb, char *from,
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int ign)
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{
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struct stat sb;
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int oerrno;
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/*
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* if from file exists, it has to be unlinked to make the link. If the
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* file exists and -k is set, skip it quietly
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*/
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if (lstat(from, &sb) == 0) {
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if (kflag)
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return(0);
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/*
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* make sure it is not the same file, protect the user
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*/
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if ((to_sb->st_dev==sb.st_dev)&&(to_sb->st_ino == sb.st_ino)) {
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paxwarn(1, "Unable to link file %s to itself", to);
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return(-1);
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}
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/*
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* try to get rid of the file, based on the type
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*/
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if (S_ISDIR(sb.st_mode)) {
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if (rmdir(from) < 0) {
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syswarn(1, errno, "Unable to remove %s", from);
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return(-1);
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}
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} else if (unlink(from) < 0) {
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if (!ign) {
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syswarn(1, errno, "Unable to remove %s", from);
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return(-1);
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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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* from file is gone (or did not exist), try to make the hard link.
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* if it fails, check the path and try it again (if chk_path() says to
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* try again)
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*/
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for (;;) {
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if (link(to, from) == 0)
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break;
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oerrno = errno;
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if (!nodirs && chk_path(from, to_sb->st_uid, to_sb->st_gid) == 0)
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continue;
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if (!ign) {
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syswarn(1, oerrno, "Could not link to %s from %s", to,
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from);
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return(-1);
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}
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return(1);
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}
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/*
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* all right the link was made
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*/
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return(0);
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}
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/*
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* node_creat()
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* create an entry in the file system (other than a file or hard link).
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* If successful, sets uid/gid modes and times as required.
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* Return:
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* 0 if ok, -1 otherwise
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*/
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int
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node_creat(ARCHD *arcn)
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{
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int res;
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int ign = 0;
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int oerrno;
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int pass = 0;
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mode_t file_mode;
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struct stat sb;
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/*
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* create node based on type, if that fails try to unlink the node and
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* try again. finally check the path and try again. As noted in the
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* file and link creation routines, this method seems to exhibit the
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* best performance in general use workloads.
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*/
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file_mode = arcn->sb.st_mode & FILEBITS;
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for (;;) {
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switch(arcn->type) {
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case PAX_DIR:
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res = mkdir(arcn->name, file_mode);
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if (ign)
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res = 0;
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break;
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case PAX_CHR:
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file_mode |= S_IFCHR;
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res = mknod(arcn->name, file_mode, arcn->sb.st_rdev);
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break;
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case PAX_BLK:
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file_mode |= S_IFBLK;
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res = mknod(arcn->name, file_mode, arcn->sb.st_rdev);
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break;
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case PAX_FIF:
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res = mkfifo(arcn->name, file_mode);
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break;
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case PAX_SCK:
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/*
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* Skip sockets, operation has no meaning under BSD
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*/
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paxwarn(0,
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"%s skipped. Sockets cannot be copied or extracted",
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arcn->name);
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return(-1);
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case PAX_SLK:
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res = symlink(arcn->ln_name, arcn->name);
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break;
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case PAX_CTG:
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case PAX_HLK:
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case PAX_HRG:
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case PAX_REG:
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default:
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/*
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* we should never get here
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*/
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paxwarn(0, "%s has an unknown file type, skipping",
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arcn->name);
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return(-1);
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}
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/*
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* if we were able to create the node break out of the loop,
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* otherwise try to unlink the node and try again. if that
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* fails check the full path and try a final time.
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*/
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if (res == 0)
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break;
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/*
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* we failed to make the node
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*/
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oerrno = errno;
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if ((ign = unlnk_exist(arcn->name, arcn->type)) < 0)
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return(-1);
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if (++pass <= 1)
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continue;
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if (nodirs || chk_path(arcn->name,arcn->sb.st_uid,arcn->sb.st_gid) < 0) {
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syswarn(1, oerrno, "Could not create: %s", arcn->name);
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return(-1);
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}
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}
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/*
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* we were able to create the node. set uid/gid, modes and times
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*/
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if (pids)
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res = set_ids(arcn->name, arcn->sb.st_uid, arcn->sb.st_gid);
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else
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res = 0;
|
|
|
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/*
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* IMPORTANT SECURITY NOTE:
|
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* if not preserving mode or we cannot set uid/gid, then PROHIBIT any
|
|
* set uid/gid bits
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*/
|
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if (!pmode || res)
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|
arcn->sb.st_mode &= ~(SETBITS);
|
|
if (pmode)
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|
set_pmode(arcn->name, arcn->sb.st_mode);
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|
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if (arcn->type == PAX_DIR && strcmp(NM_CPIO, argv0) != 0) {
|
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/*
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* Dirs must be processed again at end of extract to set times
|
|
* and modes to agree with those stored in the archive. However
|
|
* to allow extract to continue, we may have to also set owner
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* rights. This allows nodes in the archive that are children
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* of this directory to be extracted without failure. Both time
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* and modes will be fixed after the entire archive is read and
|
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* before pax exits.
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*/
|
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if (access(arcn->name, R_OK | W_OK | X_OK) < 0) {
|
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if (lstat(arcn->name, &sb) < 0) {
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syswarn(0, errno,"Could not access %s (stat)",
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arcn->name);
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set_pmode(arcn->name,file_mode | S_IRWXU);
|
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} else {
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/*
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|
* We have to add rights to the dir, so we make
|
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* sure to restore the mode. The mode must be
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* restored AS CREATED and not as stored if
|
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* pmode is not set.
|
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*/
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set_pmode(arcn->name,
|
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((sb.st_mode & FILEBITS) | S_IRWXU));
|
|
if (!pmode)
|
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arcn->sb.st_mode = sb.st_mode;
|
|
}
|
|
|
|
/*
|
|
* we have to force the mode to what was set here,
|
|
* since we changed it from the default as created.
|
|
*/
|
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add_dir(arcn->name, arcn->nlen, &(arcn->sb), 1);
|
|
} else if (pmode || patime || pmtime)
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|
add_dir(arcn->name, arcn->nlen, &(arcn->sb), 0);
|
|
}
|
|
|
|
if (patime || pmtime)
|
|
set_ftime(arcn->name, arcn->sb.st_mtime, arcn->sb.st_atime, 0);
|
|
return(0);
|
|
}
|
|
|
|
/*
|
|
* unlnk_exist()
|
|
* Remove node from file system with the specified name. We pass the type
|
|
* of the node that is going to replace it. When we try to create a
|
|
* directory and find that it already exists, we allow processing to
|
|
* continue as proper modes etc will always be set for it later on.
|
|
* Return:
|
|
* 0 is ok to proceed, no file with the specified name exists
|
|
* -1 we were unable to remove the node, or we should not remove it (-k)
|
|
* 1 we found a directory and we were going to create a directory.
|
|
*/
|
|
|
|
int
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|
unlnk_exist(char *name, int type)
|
|
{
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|
struct stat sb;
|
|
|
|
/*
|
|
* the file does not exist, or -k we are done
|
|
*/
|
|
if (lstat(name, &sb) < 0)
|
|
return(0);
|
|
if (kflag)
|
|
return(-1);
|
|
|
|
if (S_ISDIR(sb.st_mode)) {
|
|
/*
|
|
* try to remove a directory, if it fails and we were going to
|
|
* create a directory anyway, tell the caller (return a 1)
|
|
*/
|
|
if (rmdir(name) < 0) {
|
|
if (type == PAX_DIR)
|
|
return(1);
|
|
syswarn(1,errno,"Unable to remove directory %s", name);
|
|
return(-1);
|
|
}
|
|
return(0);
|
|
}
|
|
|
|
/*
|
|
* try to get rid of all non-directory type nodes
|
|
*/
|
|
if (unlink(name) < 0) {
|
|
syswarn(1, errno, "Could not unlink %s", name);
|
|
return(-1);
|
|
}
|
|
return(0);
|
|
}
|
|
|
|
/*
|
|
* chk_path()
|
|
* We were trying to create some kind of node in the file system and it
|
|
* failed. chk_path() makes sure the path up to the node exists and is
|
|
* writeable. When we have to create a directory that is missing along the
|
|
* path somewhere, the directory we create will be set to the same
|
|
* uid/gid as the file has (when uid and gid are being preserved).
|
|
* NOTE: this routine is a real performance loss. It is only used as a
|
|
* last resort when trying to create entries in the file system.
|
|
* Return:
|
|
* -1 when it could find nothing it is allowed to fix.
|
|
* 0 otherwise
|
|
*/
|
|
|
|
int
|
|
chk_path( char *name, uid_t st_uid, gid_t st_gid)
|
|
{
|
|
char *spt = name;
|
|
struct stat sb;
|
|
int retval = -1;
|
|
|
|
/*
|
|
* watch out for paths with nodes stored directly in / (e.g. /bozo)
|
|
*/
|
|
if (*spt == '/')
|
|
++spt;
|
|
|
|
for(;;) {
|
|
/*
|
|
* work forward from the first / and check each part of the path
|
|
*/
|
|
spt = strchr(spt, '/');
|
|
if (spt == NULL)
|
|
break;
|
|
*spt = '\0';
|
|
|
|
/*
|
|
* if it exists we assume it is a directory, it is not within
|
|
* the spec (at least it seems to read that way) to alter the
|
|
* file system for nodes NOT EXPLICITLY stored on the archive.
|
|
* If that assumption is changed, you would test the node here
|
|
* and figure out how to get rid of it (probably like some
|
|
* recursive unlink()) or fix up the directory permissions if
|
|
* required (do an access()).
|
|
*/
|
|
if (lstat(name, &sb) == 0) {
|
|
*(spt++) = '/';
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* the path fails at this point, see if we can create the
|
|
* needed directory and continue on
|
|
*/
|
|
if (mkdir(name, S_IRWXU | S_IRWXG | S_IRWXO) < 0) {
|
|
*spt = '/';
|
|
retval = -1;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* we were able to create the directory. We will tell the
|
|
* caller that we found something to fix, and it is ok to try
|
|
* and create the node again.
|
|
*/
|
|
retval = 0;
|
|
if (pids)
|
|
(void)set_ids(name, st_uid, st_gid);
|
|
|
|
/*
|
|
* make sure the user doesn't have some strange umask that
|
|
* causes this newly created directory to be unusable. We fix
|
|
* the modes and restore them back to the creation default at
|
|
* the end of pax
|
|
*/
|
|
if ((access(name, R_OK | W_OK | X_OK) < 0) &&
|
|
(lstat(name, &sb) == 0)) {
|
|
set_pmode(name, ((sb.st_mode & FILEBITS) | S_IRWXU));
|
|
add_dir(name, spt - name, &sb, 1);
|
|
}
|
|
*(spt++) = '/';
|
|
continue;
|
|
}
|
|
return(retval);
|
|
}
|
|
|
|
/*
|
|
* set_ftime()
|
|
* Set the access time and modification time for a named file. If frc is
|
|
* non-zero we force these times to be set even if the user did not
|
|
* request access and/or modification time preservation (this is also
|
|
* used by -t to reset access times).
|
|
* When frc is zero, only those times the user has asked for are set, the
|
|
* other ones are left alone. We do not assume the un-documented feature
|
|
* of many lutimes() implementations that consider a 0 time value as a do
|
|
* not set request.
|
|
*/
|
|
|
|
void
|
|
set_ftime(char *fnm, time_t mtime, time_t atime, int frc)
|
|
{
|
|
static struct timeval tv[2] = {{0L, 0L}, {0L, 0L}};
|
|
struct stat sb;
|
|
|
|
tv[0].tv_sec = atime;
|
|
tv[1].tv_sec = mtime;
|
|
if (!frc && (!patime || !pmtime)) {
|
|
/*
|
|
* if we are not forcing, only set those times the user wants
|
|
* set. We get the current values of the times if we need them.
|
|
*/
|
|
if (lstat(fnm, &sb) == 0) {
|
|
if (!patime)
|
|
tv[0].tv_sec = sb.st_atime;
|
|
if (!pmtime)
|
|
tv[1].tv_sec = sb.st_mtime;
|
|
} else
|
|
syswarn(0,errno,"Unable to obtain file stats %s", fnm);
|
|
}
|
|
|
|
/*
|
|
* set the times
|
|
*/
|
|
if (lutimes(fnm, tv) < 0)
|
|
syswarn(1, errno, "Access/modification time set failed on: %s",
|
|
fnm);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* set_ids()
|
|
* set the uid and gid of a file system node
|
|
* Return:
|
|
* 0 when set, -1 on failure
|
|
*/
|
|
|
|
int
|
|
set_ids(char *fnm, uid_t uid, gid_t gid)
|
|
{
|
|
if (lchown(fnm, uid, gid) < 0) {
|
|
/*
|
|
* ignore EPERM unless in verbose mode or being run by root.
|
|
* if running as pax, POSIX requires a warning.
|
|
*/
|
|
if (strcmp(NM_PAX, argv0) == 0 || errno != EPERM || vflag ||
|
|
geteuid() == 0)
|
|
syswarn(1, errno, "Unable to set file uid/gid of %s",
|
|
fnm);
|
|
return(-1);
|
|
}
|
|
return(0);
|
|
}
|
|
|
|
/*
|
|
* set_pmode()
|
|
* Set file access mode
|
|
*/
|
|
|
|
void
|
|
set_pmode(char *fnm, mode_t mode)
|
|
{
|
|
mode &= ABITS;
|
|
if (lchmod(fnm, mode) < 0)
|
|
syswarn(1, errno, "Could not set permissions on %s", fnm);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* file_write()
|
|
* Write/copy a file (during copy or archive extract). This routine knows
|
|
* how to copy files with lseek holes in it. (Which are read as file
|
|
* blocks containing all 0's but do not have any file blocks associated
|
|
* with the data). Typical examples of these are files created by dbm
|
|
* variants (.pag files). While the file size of these files are huge, the
|
|
* actual storage is quite small (the files are sparse). The problem is
|
|
* the holes read as all zeros so are probably stored on the archive that
|
|
* way (there is no way to determine if the file block is really a hole,
|
|
* we only know that a file block of all zero's can be a hole).
|
|
* At this writing, no major archive format knows how to archive files
|
|
* with holes. However, on extraction (or during copy, -rw) we have to
|
|
* deal with these files. Without detecting the holes, the files can
|
|
* consume a lot of file space if just written to disk. This replacement
|
|
* for write when passed the basic allocation size of a file system block,
|
|
* uses lseek whenever it detects the input data is all 0 within that
|
|
* file block. In more detail, the strategy is as follows:
|
|
* While the input is all zero keep doing an lseek. Keep track of when we
|
|
* pass over file block boundaries. Only write when we hit a non zero
|
|
* input. once we have written a file block, we continue to write it to
|
|
* the end (we stop looking at the input). When we reach the start of the
|
|
* next file block, start checking for zero blocks again. Working on file
|
|
* block boundaries significantly reduces the overhead when copying files
|
|
* that are NOT very sparse. This overhead (when compared to a write) is
|
|
* almost below the measurement resolution on many systems. Without it,
|
|
* files with holes cannot be safely copied. It does has a side effect as
|
|
* it can put holes into files that did not have them before, but that is
|
|
* not a problem since the file contents are unchanged (in fact it saves
|
|
* file space). (Except on paging files for diskless clients. But since we
|
|
* cannot determine one of those file from here, we ignore them). If this
|
|
* ever ends up on a system where CTG files are supported and the holes
|
|
* are not desired, just do a conditional test in those routines that
|
|
* call file_write() and have it call write() instead. BEFORE CLOSING THE
|
|
* FILE, make sure to call file_flush() when the last write finishes with
|
|
* an empty block. A lot of file systems will not create an lseek hole at
|
|
* the end. In this case we drop a single 0 at the end to force the
|
|
* trailing 0's in the file.
|
|
* ---Parameters---
|
|
* rem: how many bytes left in this file system block
|
|
* isempt: have we written to the file block yet (is it empty)
|
|
* sz: basic file block allocation size
|
|
* cnt: number of bytes on this write
|
|
* str: buffer to write
|
|
* Return:
|
|
* number of bytes written, -1 on write (or lseek) error.
|
|
*/
|
|
|
|
int
|
|
file_write(int fd, char *str, int cnt, int *rem, int *isempt, int sz,
|
|
char *name)
|
|
{
|
|
char *pt;
|
|
char *end;
|
|
int wcnt;
|
|
char *st = str;
|
|
|
|
/*
|
|
* while we have data to process
|
|
*/
|
|
while (cnt) {
|
|
if (!*rem) {
|
|
/*
|
|
* We are now at the start of file system block again
|
|
* (or what we think one is...). start looking for
|
|
* empty blocks again
|
|
*/
|
|
*isempt = 1;
|
|
*rem = sz;
|
|
}
|
|
|
|
/*
|
|
* only examine up to the end of the current file block or
|
|
* remaining characters to write, whatever is smaller
|
|
*/
|
|
wcnt = MIN(cnt, *rem);
|
|
cnt -= wcnt;
|
|
*rem -= wcnt;
|
|
if (*isempt) {
|
|
/*
|
|
* have not written to this block yet, so we keep
|
|
* looking for zero's
|
|
*/
|
|
pt = st;
|
|
end = st + wcnt;
|
|
|
|
/*
|
|
* look for a zero filled buffer
|
|
*/
|
|
while ((pt < end) && (*pt == '\0'))
|
|
++pt;
|
|
|
|
if (pt == end) {
|
|
/*
|
|
* skip, buf is empty so far
|
|
*/
|
|
if (lseek(fd, (off_t)wcnt, SEEK_CUR) < 0) {
|
|
syswarn(1,errno,"File seek on %s",
|
|
name);
|
|
return(-1);
|
|
}
|
|
st = pt;
|
|
continue;
|
|
}
|
|
/*
|
|
* drat, the buf is not zero filled
|
|
*/
|
|
*isempt = 0;
|
|
}
|
|
|
|
/*
|
|
* have non-zero data in this file system block, have to write
|
|
*/
|
|
if (write(fd, st, wcnt) != wcnt) {
|
|
syswarn(1, errno, "Failed write to file %s", name);
|
|
return(-1);
|
|
}
|
|
st += wcnt;
|
|
}
|
|
return(st - str);
|
|
}
|
|
|
|
/*
|
|
* file_flush()
|
|
* when the last file block in a file is zero, many file systems will not
|
|
* let us create a hole at the end. To get the last block with zeros, we
|
|
* write the last BYTE with a zero (back up one byte and write a zero).
|
|
*/
|
|
|
|
void
|
|
file_flush(int fd, char *fname, int isempt)
|
|
{
|
|
static char blnk[] = "\0";
|
|
|
|
/*
|
|
* silly test, but make sure we are only called when the last block is
|
|
* filled with all zeros.
|
|
*/
|
|
if (!isempt)
|
|
return;
|
|
|
|
/*
|
|
* move back one byte and write a zero
|
|
*/
|
|
if (lseek(fd, (off_t)-1, SEEK_CUR) < 0) {
|
|
syswarn(1, errno, "Failed seek on file %s", fname);
|
|
return;
|
|
}
|
|
|
|
if (write(fd, blnk, 1) < 0)
|
|
syswarn(1, errno, "Failed write to file %s", fname);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* rdfile_close()
|
|
* close a file we have beed reading (to copy or archive). If we have to
|
|
* reset access time (tflag) do so (the times are stored in arcn).
|
|
*/
|
|
|
|
void
|
|
rdfile_close(ARCHD *arcn, int *fd)
|
|
{
|
|
/*
|
|
* make sure the file is open
|
|
*/
|
|
if (*fd < 0)
|
|
return;
|
|
|
|
(void)close(*fd);
|
|
*fd = -1;
|
|
if (!tflag)
|
|
return;
|
|
|
|
/*
|
|
* user wants last access time reset
|
|
*/
|
|
set_ftime(arcn->org_name, arcn->sb.st_mtime, arcn->sb.st_atime, 1);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* set_crc()
|
|
* read a file to calculate its crc. This is a real drag. Archive formats
|
|
* that have this, end up reading the file twice (we have to write the
|
|
* header WITH the crc before writing the file contents. Oh well...
|
|
* Return:
|
|
* 0 if was able to calculate the crc, -1 otherwise
|
|
*/
|
|
|
|
int
|
|
set_crc(ARCHD *arcn, int fd)
|
|
{
|
|
int i;
|
|
int res;
|
|
off_t cpcnt = 0L;
|
|
u_long size;
|
|
unsigned long crc = 0L;
|
|
char tbuf[FILEBLK];
|
|
struct stat sb;
|
|
|
|
if (fd < 0) {
|
|
/*
|
|
* hmm, no fd, should never happen. well no crc then.
|
|
*/
|
|
arcn->crc = 0L;
|
|
return(0);
|
|
}
|
|
|
|
if ((size = (u_long)arcn->sb.st_blksize) > (u_long)sizeof(tbuf))
|
|
size = (u_long)sizeof(tbuf);
|
|
|
|
/*
|
|
* read all the bytes we think that there are in the file. If the user
|
|
* is trying to archive an active file, forget this file.
|
|
*/
|
|
for(;;) {
|
|
if ((res = read(fd, tbuf, size)) <= 0)
|
|
break;
|
|
cpcnt += res;
|
|
for (i = 0; i < res; ++i)
|
|
crc += (tbuf[i] & 0xff);
|
|
}
|
|
|
|
/*
|
|
* safety check. we want to avoid archiving files that are active as
|
|
* they can create inconsistent archive copies.
|
|
*/
|
|
if (cpcnt != arcn->sb.st_size)
|
|
paxwarn(1, "File changed size %s", arcn->org_name);
|
|
else if (fstat(fd, &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 read", arcn->org_name);
|
|
else if (lseek(fd, (off_t)0L, SEEK_SET) < 0)
|
|
syswarn(1, errno, "File rewind failed on: %s", arcn->org_name);
|
|
else {
|
|
arcn->crc = crc;
|
|
return(0);
|
|
}
|
|
return(-1);
|
|
}
|