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      1 /*	$NetBSD: pax.c,v 1.52 2024/08/05 13:37:27 riastradh Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1992 Keith Muller.
      5  * Copyright (c) 1992, 1993
      6  *	The Regents of the University of California.  All rights reserved.
      7  *
      8  * This code is derived from software contributed to Berkeley by
      9  * Keith Muller of the University of California, San Diego.
     10  *
     11  * Redistribution and use in source and binary forms, with or without
     12  * modification, are permitted provided that the following conditions
     13  * are met:
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions and the following disclaimer.
     16  * 2. Redistributions in binary form must reproduce the above copyright
     17  *    notice, this list of conditions and the following disclaimer in the
     18  *    documentation and/or other materials provided with the distribution.
     19  * 3. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 #if HAVE_NBTOOL_CONFIG_H
     37 #include "nbtool_config.h"
     38 #endif
     39 
     40 #include <sys/cdefs.h>
     41 #if !defined(lint)
     42 __COPYRIGHT("@(#) Copyright (c) 1992, 1993\
     43  The Regents of the University of California.  All rights reserved.");
     44 #if 0
     45 static char sccsid[] = "@(#)pax.c	8.2 (Berkeley) 4/18/94";
     46 #else
     47 __RCSID("$NetBSD: pax.c,v 1.52 2024/08/05 13:37:27 riastradh Exp $");
     48 #endif
     49 #endif /* not lint */
     50 
     51 #include <sys/param.h>
     52 #include <sys/resource.h>
     53 #include <sys/stat.h>
     54 #include <sys/time.h>
     55 #include <errno.h>
     56 #include <fcntl.h>
     57 #include <paths.h>
     58 #include <signal.h>
     59 #include <stdio.h>
     60 #include <stdlib.h>
     61 #include <string.h>
     62 #include <time.h>
     63 #include <unistd.h>
     64 #include <util.h>
     65 #include "pax.h"
     66 #include "extern.h"
     67 static int gen_init(void);
     68 
     69 /*
     70  * PAX main routines, general globals and some simple start up routines
     71  */
     72 
     73 /*
     74  * Variables that can be accessed by any routine within pax
     75  */
     76 int	act = ERROR;		/* read/write/append/copy */
     77 FSUB	*frmt = NULL;		/* archive format type */
     78 int	cflag;			/* match all EXCEPT pattern/file */
     79 int	cwdfd = -1;		/* starting cwd */
     80 int	dflag;			/* directory member match only  */
     81 int	iflag;			/* interactive file/archive rename */
     82 int	kflag;			/* do not overwrite existing files */
     83 int	lflag;			/* use hard links when possible */
     84 int	nflag;			/* select first archive member match */
     85 int	tflag;			/* restore access time after read */
     86 int	uflag;			/* ignore older modification time files */
     87 int	vflag;			/* produce verbose output */
     88 int	Aflag;			/* honor absolute path */
     89 int	Dflag;			/* same as uflag except inode change time */
     90 int	Hflag;			/* follow command line symlinks (write only) */
     91 int	Lflag;			/* follow symlinks when writing */
     92 int	Mflag;			/* treat stdin as an mtree(8) specfile */
     93 int	Vflag;			/* produce somewhat verbose output (no listing) */
     94 int	Xflag;			/* archive files with same device id only */
     95 int	Yflag;			/* same as Dflg except after name mode */
     96 int	Zflag;			/* same as uflg except after name mode */
     97 int	vfpart;			/* is partial verbose output in progress */
     98 int	patime = 1;		/* preserve file access time */
     99 int	pmtime = 1;		/* preserve file modification times */
    100 int	nodirs;			/* do not create directories as needed */
    101 int	pfflags = 1;		/* preserve file flags */
    102 int	pmode;			/* preserve file mode bits */
    103 int	pids;			/* preserve file uid/gid */
    104 int	rmleadslash = 0;	/* remove leading '/' from pathnames */
    105 int	exit_val;		/* exit value */
    106 int	docrc;			/* check/create file crc */
    107 int	to_stdout;		/* extract to stdout */
    108 char	*dirptr;		/* destination dir in a copy */
    109 char	*ltmfrmt;		/* -v locale time format (if any) */
    110 const char *argv0;		/* root of argv[0] */
    111 sigset_t s_mask;		/* signal mask for cleanup critical sect */
    112 FILE	*listf;			/* file pointer to print file list to */
    113 char	*tempfile;		/* tempfile to use for mkstemp(3) */
    114 char	*tempbase;		/* basename of tempfile to use for mkstemp(3) */
    115 int	forcelocal;		/* force local operation even if the name
    116 				 * contains a :
    117 				 */
    118 int	secure = 1;		/* don't extract names that contain .. */
    119 
    120 /*
    121  *	PAX - Portable Archive Interchange
    122  *
    123  *	A utility to read, write, and write lists of the members of archive
    124  *	files and copy directory hierarchies. A variety of archive formats
    125  *	are supported (some are described in POSIX 1003.1 10.1):
    126  *
    127  *		ustar - 10.1.1 extended tar interchange format
    128  *		cpio  - 10.1.2 extended cpio interchange format
    129  *		tar - old BSD 4.3 tar format
    130  *		binary cpio - old cpio with binary header format
    131  *		sysVR4 cpio -  with and without CRC
    132  *
    133  * This version is a superset of IEEE Std 1003.2b-d3
    134  *
    135  * Summary of Extensions to the IEEE Standard:
    136  *
    137  * 1	READ ENHANCEMENTS
    138  * 1.1	Operations which read archives will continue to operate even when
    139  *	processing archives which may be damaged, truncated, or fail to meet
    140  *	format specs in several different ways. Damaged sections of archives
    141  *	are detected and avoided if possible. Attempts will be made to resync
    142  *	archive read operations even with badly damaged media.
    143  * 1.2	Blocksize requirements are not strictly enforced on archive read.
    144  *	Tapes which have variable sized records can be read without errors.
    145  * 1.3	The user can specify via the non-standard option flag -E if error
    146  *	resync operation should stop on a media error, try a specified number
    147  *	of times to correct, or try to correct forever.
    148  * 1.4	Sparse files (lseek holes) stored on the archive (but stored with blocks
    149  *	of all zeros will be restored with holes appropriate for the target
    150  *	filesystem
    151  * 1.5	The user is notified whenever something is found during archive
    152  *	read operations which violates spec (but the read will continue).
    153  * 1.6	Multiple archive volumes can be read and may span over different
    154  *	archive devices
    155  * 1.7	Rigidly restores all file attributes exactly as they are stored on the
    156  *	archive.
    157  * 1.8	Modification change time ranges can be specified via multiple -T
    158  *	options. These allow a user to select files whose modification time
    159  *	lies within a specific time range.
    160  * 1.9	Files can be selected based on owner (user name or uid) via one or more
    161  *	-U options.
    162  * 1.10	Files can be selected based on group (group name or gid) via one o
    163  *	more -G options.
    164  * 1.11	File modification time can be checked against existing file after
    165  *	name modification (-Z)
    166  *
    167  * 2	WRITE ENHANCEMENTS
    168  * 2.1	Write operation will stop instead of allowing a user to create a flawed
    169  *	flawed archive (due to any problem).
    170  * 2.2	Archives written by pax are forced to strictly conform to both the
    171  *	archive and pax the specific format specifications.
    172  * 2.3	Blocking size and format is rigidly enforced on writes.
    173  * 2.4	Formats which may exhibit header overflow problems (they have fields
    174  *	too small for large file systems, such as inode number storage), use
    175  *	routines designed to repair this problem. These techniques still
    176  *	conform to both pax and format specifications, but no longer truncate
    177  *	these fields. This removes any restrictions on using these archive
    178  *	formats on large file systems.
    179  * 2.5	Multiple archive volumes can be written and may span over different
    180  *	archive devices
    181  * 2.6	A archive volume record limit allows the user to specify the number
    182  *	of bytes stored on an archive volume. When reached the user is
    183  *	prompted for the next archive volume. This is specified with the
    184  *	non-standard -B flag. The limit is rounded up to the next blocksize.
    185  * 2.7	All archive padding during write use zero filled sections. This makes
    186  *	it much easier to pull data out of flawed archive during read
    187  *	operations.
    188  * 2.8	Access time reset with the -t applies to all file nodes (including
    189  *	directories).
    190  * 2.9	Symbolic links can be followed with -L (optional in the spec).
    191  * 2.10	Modification or inode change time ranges can be specified via
    192  *	multiple -T options. These allow a user to select files whose
    193  *	modification or inode change time lies within a specific time range.
    194  * 2.11	Files can be selected based on owner (user name or uid) via one or more
    195  *	-U options.
    196  * 2.12	Files can be selected based on group (group name or gid) via one o
    197  *	more -G options.
    198  * 2.13	Symlinks which appear on the command line can be followed (without
    199  *	following other symlinks; -H flag)
    200  *
    201  * 3	COPY ENHANCEMENTS
    202  * 3.1	Sparse files (lseek holes) can be copied without expanding the holes
    203  *	into zero filled blocks. The file copy is created with holes which are
    204  *	appropriate for the target filesystem
    205  * 3.2	Access time as well as modification time on copied file trees can be
    206  *	preserved with the appropriate -p options.
    207  * 3.3	Access time reset with the -t applies to all file nodes (including
    208  *	directories).
    209  * 3.4	Symbolic links can be followed with -L (optional in the spec).
    210  * 3.5	Modification or inode change time ranges can be specified via
    211  *	multiple -T options. These allow a user to select files whose
    212  *	modification or inode change time lies within a specific time range.
    213  * 3.6	Files can be selected based on owner (user name or uid) via one or more
    214  *	-U options.
    215  * 3.7	Files can be selected based on group (group name or gid) via one o
    216  *	more -G options.
    217  * 3.8	Symlinks which appear on the command line can be followed (without
    218  *	following other symlinks; -H flag)
    219  * 3.9	File inode change time can be checked against existing file before
    220  *	name modification (-D)
    221  * 3.10	File inode change time can be checked against existing file after
    222  *	name modification (-Y)
    223  * 3.11	File modification time can be checked against existing file after
    224  *	name modification (-Z)
    225  *
    226  * 4	GENERAL ENHANCEMENTS
    227  * 4.1	Internal structure is designed to isolate format dependent and
    228  *	independent functions. Formats are selected via a format driver table.
    229  *	This encourages the addition of new archive formats by only having to
    230  *	write those routines which id, read and write the archive header.
    231  */
    232 
    233 /*
    234  * main()
    235  *	parse options, set up and operate as specified by the user.
    236  *	any operational flaw will set exit_val to non-zero
    237  * Return: 0 if ok, 1 otherwise
    238  */
    239 
    240 int
    241 main(int argc, char **argv)
    242 {
    243 	const char *tmpdir;
    244 	size_t tdlen;
    245 	int rval;
    246 
    247 	setprogname(argv[0]);
    248 
    249 	listf = stderr;
    250 
    251 	/*
    252 	 * parse options, determine operational mode
    253 	 */
    254 	options(argc, argv);
    255 
    256 	/*
    257 	 * general init
    258 	 */
    259 	if ((gen_init() < 0) || (tty_init() < 0))
    260 		return exit_val;
    261 
    262 	/*
    263 	 * For any actions other than LIST, keep a reference to cwd, so
    264 	 * we can always come back home.
    265 	 *
    266 	 * For EXTRACT (pax -r) without --insecure, also save the path
    267 	 * to cwd to check for escape attempts.
    268 	 */
    269 	if (act != LIST) {
    270 		cwdfd = open(".", O_RDONLY);
    271 		if (cwdfd < 0) {
    272 			syswarn(1, errno,
    273 			    "Can't open current working directory.");
    274 			return exit_val;
    275 		}
    276 		if (act == EXTRACT && secure) {
    277 			if (updatepath() == -1)
    278 				return exit_val;
    279 		}
    280 	}
    281 
    282 	/*
    283 	 * Where should we put temporary files?
    284 	 */
    285 	if ((tmpdir = getenv("TMPDIR")) == NULL || *tmpdir == '\0')
    286 		tmpdir = _PATH_TMP;
    287 	tdlen = strlen(tmpdir);
    288 	while(tdlen > 0 && tmpdir[tdlen - 1] == '/')
    289 		tdlen--;
    290 	tempfile = malloc(tdlen + 1 + sizeof(_TFILE_BASE));
    291 	if (tempfile == NULL) {
    292 		tty_warn(1, "Cannot allocate memory for temp file name.");
    293 		return exit_val;
    294 	}
    295 	if (tdlen)
    296 		memcpy(tempfile, tmpdir, tdlen);
    297 	tempbase = tempfile + tdlen;
    298 	*tempbase++ = '/';
    299 
    300 	(void)time(&starttime);
    301 #ifdef SIGINFO
    302 	(void)signal(SIGINFO, ar_summary);
    303 #endif
    304 	/*
    305 	 * select a primary operation mode
    306 	 */
    307 	switch (act) {
    308 	case EXTRACT:
    309 		rval = extract();
    310 		break;
    311 	case ARCHIVE:
    312 		rval = archive();
    313 		break;
    314 	case APPND:
    315 		if (gzip_program != NULL)
    316 			err(1, "cannot gzip while appending");
    317 		rval = append();
    318 		/*
    319 		 * Check if we tried to append on an empty file and
    320 		 * turned into ARCHIVE mode.
    321 		 */
    322 		if (act == -ARCHIVE) {
    323 			act = ARCHIVE;
    324 			rval = archive();
    325 		}
    326 		break;
    327 	case COPY:
    328 		rval = copy();
    329 		break;
    330 	default:
    331 	case LIST:
    332 		rval = list();
    333 		break;
    334 	}
    335 	if (rval != 0)
    336 		exit_val = 1;
    337 	return exit_val;
    338 }
    339 
    340 /*
    341  * sig_cleanup()
    342  *	when interrupted we try to do whatever delayed processing we can.
    343  *	This is not critical, but we really ought to limit our damage when we
    344  *	are aborted by the user.
    345  * Return:
    346  *	never....
    347  */
    348 
    349 __dead static void
    350 sig_cleanup(int which_sig)
    351 {
    352 	/*
    353 	 * restore modes and times for any dirs we may have created
    354 	 * or any dirs we may have read. Set vflag and vfpart so the user
    355 	 * will clearly see the message on a line by itself.
    356 	 */
    357 	vflag = vfpart = 1;
    358 #ifdef SIGXCPU
    359 	if (which_sig == SIGXCPU)
    360 		tty_warn(1, "CPU time limit reached, cleaning up.");
    361 	else
    362 #endif
    363 		tty_warn(1, "Signal caught, cleaning up.");
    364 
    365 	/* delete any open temporary file */
    366 	if (xtmp_name)
    367 		(void)unlink(xtmp_name);
    368 	ar_close();
    369 	proc_dir();
    370 	if (tflag)
    371 		atdir_end();
    372 
    373 	(void)raise_default_signal(which_sig);
    374 	exit(1);
    375 }
    376 
    377 /*
    378  * gen_init()
    379  *	general setup routines. Not all are required, but they really help
    380  *	when dealing with a medium to large sized archives.
    381  */
    382 
    383 static int
    384 gen_init(void)
    385 {
    386 	struct rlimit reslimit;
    387 	struct sigaction n_hand;
    388 	struct sigaction o_hand;
    389 
    390 	/*
    391 	 * Really needed to handle large archives. We can run out of memory for
    392 	 * internal tables really fast when we have a whole lot of files...
    393 	 */
    394 	if (getrlimit(RLIMIT_DATA , &reslimit) == 0){
    395 		reslimit.rlim_cur = reslimit.rlim_max;
    396 		(void)setrlimit(RLIMIT_DATA , &reslimit);
    397 	}
    398 
    399 	/*
    400 	 * should file size limits be waived? if the os limits us, this is
    401 	 * needed if we want to write a large archive
    402 	 */
    403 	if (getrlimit(RLIMIT_FSIZE , &reslimit) == 0){
    404 		reslimit.rlim_cur = reslimit.rlim_max;
    405 		(void)setrlimit(RLIMIT_FSIZE , &reslimit);
    406 	}
    407 
    408 	/*
    409 	 * increase the size the stack can grow to
    410 	 */
    411 	if (getrlimit(RLIMIT_STACK , &reslimit) == 0){
    412 		reslimit.rlim_cur = reslimit.rlim_max;
    413 		(void)setrlimit(RLIMIT_STACK , &reslimit);
    414 	}
    415 
    416 #ifdef RLIMIT_RSS
    417 	/*
    418 	 * not really needed, but doesn't hurt
    419 	 */
    420 	if (getrlimit(RLIMIT_RSS , &reslimit) == 0){
    421 		reslimit.rlim_cur = reslimit.rlim_max;
    422 		(void)setrlimit(RLIMIT_RSS , &reslimit);
    423 	}
    424 #endif
    425 
    426 	/*
    427 	 * Handle posix locale
    428 	 *
    429 	 * set user defines time printing format for -v option
    430 	 */
    431 	ltmfrmt = getenv("LC_TIME");
    432 
    433 	/*
    434 	 * signal handling to reset stored directory times and modes. Since
    435 	 * we deal with broken pipes via failed writes we ignore it. We also
    436 	 * deal with any file size limit through failed writes. CPU time
    437 	 * limits are caught and a cleanup is forced.
    438 	 */
    439 	if ((sigemptyset(&s_mask) < 0) || (sigaddset(&s_mask, SIGTERM) < 0) ||
    440 	    (sigaddset(&s_mask,SIGINT) < 0)||(sigaddset(&s_mask,SIGHUP) < 0) ||
    441 	    (sigaddset(&s_mask,SIGPIPE) < 0)||(sigaddset(&s_mask,SIGQUIT)<0)){
    442 		tty_warn(1, "Unable to set up signal mask");
    443 		return -1;
    444 	}
    445 #ifdef SIGXCPU
    446 	if (sigaddset(&s_mask,SIGXCPU) < 0) {
    447 		tty_warn(1, "Unable to set up signal mask");
    448 		return -1;
    449 	}
    450 #endif
    451 #ifdef SIGXFSZ
    452 	if (sigaddset(&s_mask,SIGXFSZ) < 0) {
    453 		tty_warn(1, "Unable to set up signal mask");
    454 		return -1;
    455 	}
    456 #endif
    457 
    458 	memset(&n_hand, 0, sizeof n_hand);
    459 	n_hand.sa_mask = s_mask;
    460 	n_hand.sa_flags = 0;
    461 	n_hand.sa_handler = sig_cleanup;
    462 
    463 	if ((sigaction(SIGHUP, &n_hand, &o_hand) < 0) &&
    464 	    (o_hand.sa_handler == SIG_IGN) &&
    465 	    (sigaction(SIGHUP, &o_hand, NULL) < 0))
    466 		goto out;
    467 
    468 	if ((sigaction(SIGTERM, &n_hand, &o_hand) < 0) &&
    469 	    (o_hand.sa_handler == SIG_IGN) &&
    470 	    (sigaction(SIGTERM, &o_hand, NULL) < 0))
    471 		goto out;
    472 
    473 	if ((sigaction(SIGINT, &n_hand, &o_hand) < 0) &&
    474 	    (o_hand.sa_handler == SIG_IGN) &&
    475 	    (sigaction(SIGINT, &o_hand, NULL) < 0))
    476 		goto out;
    477 
    478 	if ((sigaction(SIGQUIT, &n_hand, &o_hand) < 0) &&
    479 	    (o_hand.sa_handler == SIG_IGN) &&
    480 	    (sigaction(SIGQUIT, &o_hand, NULL) < 0))
    481 		goto out;
    482 
    483 #ifdef SIGXCPU
    484 	if ((sigaction(SIGXCPU, &n_hand, &o_hand) < 0) &&
    485 	    (o_hand.sa_handler == SIG_IGN) &&
    486 	    (sigaction(SIGXCPU, &o_hand, NULL) < 0))
    487 		goto out;
    488 #endif
    489 	n_hand.sa_handler = SIG_IGN;
    490 	if (sigaction(SIGPIPE, &n_hand, &o_hand) < 0)
    491 		goto out;
    492 #ifdef SIGXFSZ
    493 	if (sigaction(SIGXFSZ, &n_hand, &o_hand) < 0)
    494 		goto out;
    495 #endif
    496 	return 0;
    497 
    498     out:
    499 	syswarn(1, errno, "Unable to set up signal handler");
    500 	return -1;
    501 }
    502