text: /*	$OpenBSD: pax.c,v 1.13 1998/07/27 05:18:29 millert Exp $	*/
  /*	$NetBSD: pax.c,v 1.5 1996/03/26 23:54:20 mrg 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. All advertising materials mentioning features or use of this software
   *    must display the following acknowledgement:
   *	This product includes software developed by the University of
   *	California, Berkeley and its contributors.
   * 4. 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.
   */
  
  #ifndef lint
  static char copyright[] =
  "@(#) Copyright (c) 1992, 1993\n\
  	The Regents of the University of California.  All rights reserved.\n";
  #endif /* not lint */
  
  #ifndef lint
  #if 0
  static char sccsid[] = "@(#)pax.c	8.2 (Berkeley) 4/18/94";
  #else
  static char rcsid[] = "$OpenBSD: pax.c,v 1.13 1998/07/27 05:18:29 millert Exp $";
  #endif
  #endif /* not lint */
  
  #include <stdio.h>
  #include <sys/types.h>
  #include <sys/param.h>
  #include <sys/stat.h>
  #include <sys/time.h>
  #include <sys/resource.h>
  #include <signal.h>
  #include <unistd.h>
  #include <stdlib.h>
  #include <string.h>
  #include <errno.h>
  #include <fcntl.h>
  #include "pax.h"
  #include "extern.h"
  static int gen_init __P((void));
  
  /*
   * PAX main routines, general globals and some simple start up routines
   */
  
  /*
   * Variables that can be accessed by any routine within pax
   */
  int	act = DEFOP;		/* read/write/append/copy */
  FSUB	*frmt = NULL;		/* archive format type */
  int	cflag;			/* match all EXCEPT pattern/file */
  int	cwdfd;			/* starting cwd */
  int	dflag;			/* directory member match only  */
  int	iflag;			/* interactive file/archive rename */
  int	kflag;			/* do not overwrite existing files */
  int	lflag;			/* use hard links when possible */
  int	nflag;			/* select first archive member match */
  int	tflag;			/* restore access time after read */
  int	uflag;			/* ignore older modification time files */
  int	vflag;			/* produce verbose output */
  int	zflag;			/* use gzip */
  int	Dflag;			/* same as uflag except inode change time */
  int	Hflag;			/* follow command line symlinks (write only) */
  int	Lflag;			/* follow symlinks when writing */
  int	Xflag;			/* archive files with same device id only */
  int	Yflag;			/* same as Dflg except after name mode */
  int	Zflag;			/* same as uflg except after name mode */
  int	vfpart;			/* is partial verbose output in progress */
  int	patime = 1;		/* preserve file access time */
  int	pmtime = 1;		/* preserve file modification times */
  int	nodirs;			/* do not create directories as needed */
  int	pmode;			/* preserve file mode bits */
  int	pids;			/* preserve file uid/gid */
  int	rmleadslash = 0;	/* remove leading '/' from pathnames */
  int	exit_val;		/* exit value */
  int	docrc;			/* check/create file crc */
  char	*dirptr;		/* destination dir in a copy */
  char	*ltmfrmt;		/* -v locale time format (if any) */
  char	*argv0;			/* root of argv[0] */
  sigset_t s_mask;		/* signal mask for cleanup critical sect */
  
  /*
   *	PAX - Portable Archive Interchange
   *
   * 	A utility to read, write, and write lists of the members of archive
   *	files and copy directory hierarchies. A variety of archive formats
   *	are supported (some are described in POSIX 1003.1 10.1):
   *
   *		ustar - 10.1.1 extended tar interchange format
   *		cpio  - 10.1.2 extended cpio interchange format
   *		tar - old BSD 4.3 tar format
   *		binary cpio - old cpio with binary header format
   *		sysVR4 cpio -  with and without CRC
   *
   * This version is a superset of IEEE Std 1003.2b-d3
   *
   * Summary of Extensions to the IEEE Standard:
   *
   * 1	READ ENHANCEMENTS
   * 1.1	Operations which read archives will continue to operate even when
   *	processing archives which may be damaged, truncated, or fail to meet 
   *	format specs in several different ways. Damaged sections of archives
   *	are detected and avoided if possible. Attempts will be made to resync
   *	archive read operations even with badly damaged media.
   * 1.2	Blocksize requirements are not strictly enforced on archive read.
   *	Tapes which have variable sized records can be read without errors.
   * 1.3	The user can specify via the non-standard option flag -E if error
   *	resync operation should stop on a media error, try a specified number
   *	of times to correct, or try to correct forever.
   * 1.4	Sparse files (lseek holes) stored on the archive (but stored with blocks
   *	of all zeros will be restored with holes appropriate for the target
   *	filesystem
   * 1.5	The user is notified whenever something is found during archive
   *	read operations which violates spec (but the read will continue).
   * 1.6	Multiple archive volumes can be read and may span over different
   *	archive devices 
   * 1.7	Rigidly restores all file attributes exactly as they are stored on the
   *	archive.
   * 1.8	Modification change time ranges can be specified via multiple -T
   *	options. These allow a user to select files whose modification time
   *	lies within a specific time range.
   * 1.9	Files can be selected based on owner (user name or uid) via one or more
   *	-U options.
   * 1.10	Files can be selected based on group (group name or gid) via one o
   *	more -G options.
   * 1.11	File modification time can be checked against exisiting file after
   *	name modification (-Z)
   *
   * 2	WRITE ENHANCEMENTS
   * 2.1	Write operation will stop instead of allowing a user to create a flawed
   *	flawed archive (due to any problem).
   * 2.2	Archives writtens by pax are forced to strictly conform to both the
   *	archive and pax the spceific format specifications.
   * 2.3	Blocking size and format is rigidly enforced on writes.
   * 2.4	Formats which may exhibit header overflow problems (they have fields
   *	too small for large file systems, such as inode number storage), use
   *	routines designed to repair this problem. These techniques still
   *	conform to both pax and format specifications, but no longer truncate
   *	these fields. This removes any restrictions on using these archive
   *	formats on large file systems.
   * 2.5	Multiple archive volumes can be written and may span over different
   *	archive devices 
   * 2.6	A archive volume record limit allows the user to specify the number
   *	of bytes stored on an archive volume. When reached the user is
   *	prompted for the next archive volume. This is specified with the
   *	non-standard -B flag. THe limit is rounded up to the next blocksize.
   * 2.7	All archive padding during write use zero filled sections. This makes
   *	it much easier to pull data out of flawed archive during read
   *	operations.
   * 2.8	Access time reset with the -t applies to all file nodes (including
   *	directories).
   * 2.9	Symbolic links can be followed with -L (optional in the spec).
   * 2.10	Modification or inode change time ranges can be specified via
   *	multiple -T options. These allow a user to select files whose
   *	modification or inode change time lies within a specific time range.
   * 2.11	Files can be selected based on owner (user name or uid) via one or more
   *	-U options.
   * 2.12	Files can be selected based on group (group name or gid) via one o
   *	more -G options.
   * 2.13	Symlinks which appear on the command line can be followed (without
   *	following other symlinks; -H flag)
   *
   * 3	COPY ENHANCEMENTS
   * 3.1	Sparse files (lseek holes) can be copied without expanding the holes
   *	into zero filled blocks. The file copy is created with holes which are
   *	appropriate for the target filesystem
   * 3.2	Access time as well as modification time on copied file trees can be
   *	preserved with the appropriate -p options.
   * 3.3	Access time reset with the -t applies to all file nodes (including
   *	directories).
   * 3.4	Symbolic links can be followed with -L (optional in the spec).
   * 3.5	Modification or inode change time ranges can be specified via
   *	multiple -T options. These allow a user to select files whose
   *	modification or inode change time lies within a specific time range.
   * 3.6	Files can be selected based on owner (user name or uid) via one or more
   *	-U options.
   * 3.7	Files can be selected based on group (group name or gid) via one o
   *	more -G options.
   * 3.8	Symlinks which appear on the command line can be followed (without
   *	following other symlinks; -H flag)
   * 3.9  File inode change time can be checked against exisiting file before
   *	name modification (-D)
   * 3.10 File inode change time can be checked against exisiting file after
   *	name modification (-Y)
   * 3.11	File modification time can be checked against exisiting file after
   *	name modification (-Z)
   *
   * 4	GENERAL ENHANCEMENTS
   * 4.1	Internal structure is designed to isolate format dependent and 
   *	independent functions. Formats are selected via a format driver table.
   *	This encourages the addition of new archive formats by only having to
   *	write those routines which id, read and write the archive header.
   */
  
  /*
   * main()
   *	parse options, set up and operate as specified by the user.
   *	any operational flaw will set exit_val to non-zero
   * Return: 0 if ok, 1 otherwise
   */
  
  #ifdef __STDC__
  int
  main(int argc, char **argv)
  #else
  int
  main(argc, argv)
  	int argc;
  	char **argv;
  #endif
  {
  	/*
  	 * Keep a reference to cwd, so we can always come back home.
  	 */
  	cwdfd = open(".", O_RDONLY);
  	if (cwdfd < 0) {
  		syswarn(0, errno, "Can't open current working directory.");
  		return(exit_val);
  	}
  
  	/*
  	 * parse options, determine operational mode, general init
  	 */
  	options(argc, argv);
  	if ((gen_init() < 0) || (tty_init() < 0))
  		return(exit_val);
  
  	/*
  	 * select a primary operation mode 
  	 */
  	switch(act) {
  	case EXTRACT:
  		extract();
  		break;
  	case ARCHIVE:
  		archive();
  		break;
  	case APPND:
  		append();
  		break;
  	case COPY:
  		copy();
  		break;
  	default:
  	case LIST:
  		list();
  		break;
  	}
  	return(exit_val);
  }
  
  /*
   * sig_cleanup()
   *	when interrupted we try to do whatever delayed processing we can.
   *	This is not critical, but we really ought to limit our damage when we
   *	are aborted by the user.
   * Return:
   *	never....
   */
  
  #ifdef __STDC__
  void
  sig_cleanup(int which_sig)
  #else
  void
  sig_cleanup(which_sig)
  	int which_sig;
  #endif
  {
  	/*
  	 * restore modes and times for any dirs we may have created
  	 * or any dirs we may have read. Set vflag and vfpart so the user
  	 * will clearly see the message on a line by itself.
  	 */
  	vflag = vfpart = 1;
  	if (which_sig == SIGXCPU)
  		paxwarn(0, "Cpu time limit reached, cleaning up.");
  	else
  		paxwarn(0, "Signal caught, cleaning up.");
  
  	ar_close();
  	proc_dir();
  	if (tflag)
  		atdir_end();
  	exit(1);
  }
  
  /*
   * gen_init()
   *	general setup routines. Not all are required, but they really help
   *	when dealing with a medium to large sized archives.
   */
  
  #ifdef __STDC__
  static int
  gen_init(void)
  #else
  static int
  gen_init()
  #endif
  {
  	struct rlimit reslimit;
  	struct sigaction n_hand;
  	struct sigaction o_hand;
  
  	/*
  	 * Really needed to handle large archives. We can run out of memory for
  	 * internal tables really fast when we have a whole lot of files...
  	 */
  	if (getrlimit(RLIMIT_DATA , &reslimit) == 0){
  		reslimit.rlim_cur = reslimit.rlim_max;
  		(void)setrlimit(RLIMIT_DATA , &reslimit);
  	}
  
  	/*
  	 * should file size limits be waived? if the os limits us, this is
  	 * needed if we want to write a large archive
  	 */
  	if (getrlimit(RLIMIT_FSIZE , &reslimit) == 0){
  		reslimit.rlim_cur = reslimit.rlim_max;
  		(void)setrlimit(RLIMIT_FSIZE , &reslimit);
  	}
  
  	/*
  	 * increase the size the stack can grow to
  	 */
  	if (getrlimit(RLIMIT_STACK , &reslimit) == 0){
  		reslimit.rlim_cur = reslimit.rlim_max;
  		(void)setrlimit(RLIMIT_STACK , &reslimit);
  	}
  
  	/*
  	 * not really needed, but doesn't hurt
  	 */
  	if (getrlimit(RLIMIT_RSS , &reslimit) == 0){
  		reslimit.rlim_cur = reslimit.rlim_max;
  		(void)setrlimit(RLIMIT_RSS , &reslimit);
  	}
  
  	/*
  	 * Handle posix locale
  	 *
  	 * set user defines time printing format for -v option 
  	 */
  	ltmfrmt = getenv("LC_TIME");
  
  	/*
  	 * signal handling to reset stored directory times and modes. Since
  	 * we deal with broken pipes via failed writes we ignore it. We also
  	 * deal with any file size limit thorugh failed writes. Cpu time
  	 * limits are caught and a cleanup is forced.
  	 */
  	if ((sigemptyset(&s_mask) < 0) || (sigaddset(&s_mask, SIGTERM) < 0) ||
  	    (sigaddset(&s_mask,SIGINT) < 0)||(sigaddset(&s_mask,SIGHUP) < 0) ||
  	    (sigaddset(&s_mask,SIGPIPE) < 0)||(sigaddset(&s_mask,SIGQUIT)<0) ||
  	    (sigaddset(&s_mask,SIGXCPU) < 0)||(sigaddset(&s_mask,SIGXFSZ)<0)) {
  		paxwarn(1, "Unable to set up signal mask");
  		return(-1);
  	}
  	memset(&n_hand, 0, sizeof n_hand);
  	n_hand.sa_mask = s_mask;
  	n_hand.sa_flags = 0;
  	n_hand.sa_handler = sig_cleanup;
  
  	if ((sigaction(SIGHUP, &n_hand, &o_hand) < 0) &&
  	    (o_hand.sa_handler == SIG_IGN) &&
  	    (sigaction(SIGHUP, &o_hand, &o_hand) < 0))
  		goto out;
  
  	if ((sigaction(SIGTERM, &n_hand, &o_hand) < 0) &&
  	    (o_hand.sa_handler == SIG_IGN) &&
  	    (sigaction(SIGTERM, &o_hand, &o_hand) < 0))
  		goto out;
  
  	if ((sigaction(SIGINT, &n_hand, &o_hand) < 0) &&
  	    (o_hand.sa_handler == SIG_IGN) &&
  	    (sigaction(SIGINT, &o_hand, &o_hand) < 0))
  		goto out;
  
  	if ((sigaction(SIGQUIT, &n_hand, &o_hand) < 0) &&
  	    (o_hand.sa_handler == SIG_IGN) &&
  	    (sigaction(SIGQUIT, &o_hand, &o_hand) < 0))
  		goto out;
  
  	if ((sigaction(SIGXCPU, &n_hand, &o_hand) < 0) &&
  	    (o_hand.sa_handler == SIG_IGN) &&
  	    (sigaction(SIGXCPU, &o_hand, &o_hand) < 0))
  		goto out;
  
  	n_hand.sa_handler = SIG_IGN;
  	if ((sigaction(SIGPIPE, &n_hand, &o_hand) < 0) ||
  	    (sigaction(SIGXFSZ, &n_hand, &o_hand) < 0))
  		goto out;
  	return(0);
  
      out:
  	syswarn(1, errno, "Unable to set up signal handler");
  	return(-1);
  }
  