xref: /freebsd/bin/pax/pax.c (revision 7899f917b1c0ea178f1d2be0cfb452086d079d23)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
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 #include <sys/types.h>
37 #include <sys/stat.h>
38 #include <sys/time.h>
39 #include <sys/resource.h>
40 #include <err.h>
41 #include <errno.h>
42 #include <fcntl.h>
43 #include <locale.h>
44 #include <paths.h>
45 #include <signal.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include "pax.h"
50 #include "extern.h"
51 static int gen_init(void);
52 
53 /*
54  * PAX main routines, general globals and some simple start up routines
55  */
56 
57 /*
58  * Variables that can be accessed by any routine within pax
59  */
60 int	act = DEFOP;		/* read/write/append/copy */
61 FSUB	*frmt = NULL;		/* archive format type */
62 int	cflag;			/* match all EXCEPT pattern/file */
63 int	cwdfd;			/* starting cwd */
64 int	dflag;			/* directory member match only  */
65 int	iflag;			/* interactive file/archive rename */
66 int	kflag;			/* do not overwrite existing files */
67 int	lflag;			/* use hard links when possible */
68 int	nflag;			/* select first archive member match */
69 int	tflag;			/* restore access time after read */
70 int	uflag;			/* ignore older modification time files */
71 int	vflag;			/* produce verbose output */
72 int	Dflag;			/* same as uflag except for inode change time */
73 int	Hflag;			/* follow command line symlinks (write only) */
74 int	Lflag;			/* follow symlinks when writing */
75 int	Oflag;			/* limit to single volume */
76 int	Xflag;			/* archive files with same device id only */
77 int	Yflag;			/* same as Dflg except after name mode */
78 int	Zflag;			/* same as uflg except after name mode */
79 int	vfpart;			/* is partial verbose output in progress */
80 int	patime = 1;		/* preserve file access time */
81 int	pmtime = 1;		/* preserve file modification times */
82 int	nodirs;			/* do not create directories as needed */
83 int	pmode;			/* preserve file mode bits */
84 int	pids;			/* preserve file uid/gid */
85 int	rmleadslash = 0;	/* remove leading '/' from pathnames */
86 int	exit_val;		/* exit value */
87 int	docrc;			/* check/create file crc */
88 char	*dirptr;		/* destination dir in a copy */
89 const	char *argv0;		/* root of argv[0] */
90 sigset_t s_mask;		/* signal mask for cleanup critical sect */
91 FILE	*listf;			/* file pointer to print file list to */
92 char	*tempfile;		/* tempfile to use for mkstemp(3) */
93 char	*tempbase;		/* basename of tempfile to use for mkstemp(3) */
94 
95 /*
96  *	PAX - Portable Archive Interchange
97  *
98  *	A utility to read, write, and write lists of the members of archive
99  *	files and copy directory hierarchies. A variety of archive formats
100  *	are supported (some are described in POSIX 1003.1 10.1):
101  *
102  *		ustar - 10.1.1 extended tar interchange format
103  *		cpio  - 10.1.2 extended cpio interchange format
104  *		tar - old BSD 4.3 tar format
105  *		binary cpio - old cpio with binary header format
106  *		sysVR4 cpio -  with and without CRC
107  *
108  * This version is a superset of IEEE Std 1003.2b-d3
109  *
110  * Summary of Extensions to the IEEE Standard:
111  *
112  * 1	READ ENHANCEMENTS
113  * 1.1	Operations which read archives will continue to operate even when
114  *	processing archives which may be damaged, truncated, or fail to meet
115  *	format specs in several different ways. Damaged sections of archives
116  *	are detected and avoided if possible. Attempts will be made to resync
117  *	archive read operations even with badly damaged media.
118  * 1.2	Blocksize requirements are not strictly enforced on archive read.
119  *	Tapes which have variable sized records can be read without errors.
120  * 1.3	The user can specify via the non-standard option flag -E if error
121  *	resync operation should stop on a media error, try a specified number
122  *	of times to correct, or try to correct forever.
123  * 1.4	Sparse files (lseek holes) stored on the archive (but stored with blocks
124  *	of all zeros will be restored with holes appropriate for the target
125  *	file system
126  * 1.5	The user is notified whenever something is found during archive
127  *	read operations which violates spec (but the read will continue).
128  * 1.6	Multiple archive volumes can be read and may span over different
129  *	archive devices
130  * 1.7	Rigidly restores all file attributes exactly as they are stored on the
131  *	archive.
132  * 1.8	Modification change time ranges can be specified via multiple -T
133  *	options. These allow a user to select files whose modification time
134  *	lies within a specific time range.
135  * 1.9	Files can be selected based on owner (user name or uid) via one or more
136  *	-U options.
137  * 1.10	Files can be selected based on group (group name or gid) via one o
138  *	more -G options.
139  * 1.11	File modification time can be checked against existing file after
140  *	name modification (-Z)
141  *
142  * 2	WRITE ENHANCEMENTS
143  * 2.1	Write operation will stop instead of allowing a user to create a flawed
144  *	flawed archive (due to any problem).
145  * 2.2	Archives written by pax are forced to strictly conform to both the
146  *	archive and pax the specific format specifications.
147  * 2.3	Blocking size and format is rigidly enforced on writes.
148  * 2.4	Formats which may exhibit header overflow problems (they have fields
149  *	too small for large file systems, such as inode number storage), use
150  *	routines designed to repair this problem. These techniques still
151  *	conform to both pax and format specifications, but no longer truncate
152  *	these fields. This removes any restrictions on using these archive
153  *	formats on large file systems.
154  * 2.5	Multiple archive volumes can be written and may span over different
155  *	archive devices
156  * 2.6	A archive volume record limit allows the user to specify the number
157  *	of bytes stored on an archive volume. When reached the user is
158  *	prompted for the next archive volume. This is specified with the
159  *	non-standard -B flag. The limit is rounded up to the next blocksize.
160  * 2.7	All archive padding during write use zero filled sections. This makes
161  *	it much easier to pull data out of flawed archive during read
162  *	operations.
163  * 2.8	Access time reset with the -t applies to all file nodes (including
164  *	directories).
165  * 2.9	Symbolic links can be followed with -L (optional in the spec).
166  * 2.10	Modification or inode change time ranges can be specified via
167  *	multiple -T options. These allow a user to select files whose
168  *	modification or inode change time lies within a specific time range.
169  * 2.11	Files can be selected based on owner (user name or uid) via one or more
170  *	-U options.
171  * 2.12	Files can be selected based on group (group name or gid) via one o
172  *	more -G options.
173  * 2.13	Symlinks which appear on the command line can be followed (without
174  *	following other symlinks; -H flag)
175  *
176  * 3	COPY ENHANCEMENTS
177  * 3.1	Sparse files (lseek holes) can be copied without expanding the holes
178  *	into zero filled blocks. The file copy is created with holes which are
179  *	appropriate for the target file system
180  * 3.2	Access time as well as modification time on copied file trees can be
181  *	preserved with the appropriate -p options.
182  * 3.3	Access time reset with the -t applies to all file nodes (including
183  *	directories).
184  * 3.4	Symbolic links can be followed with -L (optional in the spec).
185  * 3.5	Modification or inode change time ranges can be specified via
186  *	multiple -T options. These allow a user to select files whose
187  *	modification or inode change time lies within a specific time range.
188  * 3.6	Files can be selected based on owner (user name or uid) via one or more
189  *	-U options.
190  * 3.7	Files can be selected based on group (group name or gid) via one o
191  *	more -G options.
192  * 3.8	Symlinks which appear on the command line can be followed (without
193  *	following other symlinks; -H flag)
194  * 3.9  File inode change time can be checked against existing file before
195  *	name modification (-D)
196  * 3.10 File inode change time can be checked against existing file after
197  *	name modification (-Y)
198  * 3.11	File modification time can be checked against existing file after
199  *	name modification (-Z)
200  *
201  * 4	GENERAL ENHANCEMENTS
202  * 4.1	Internal structure is designed to isolate format dependent and
203  *	independent functions. Formats are selected via a format driver table.
204  *	This encourages the addition of new archive formats by only having to
205  *	write those routines which id, read and write the archive header.
206  */
207 
208 /*
209  * main()
210  *	parse options, set up and operate as specified by the user.
211  *	any operational flaw will set exit_val to non-zero
212  * Return: 0 if ok, 1 otherwise
213  */
214 
215 int
216 main(int argc, char *argv[])
217 {
218 	const char *tmpdir;
219 	size_t tdlen;
220 
221 	(void) setlocale(LC_ALL, "");
222 	listf = stderr;
223 	/*
224 	 * Keep a reference to cwd, so we can always come back home.
225 	 */
226 	cwdfd = open(".", O_RDONLY | O_CLOEXEC);
227 	if (cwdfd < 0) {
228 		syswarn(0, errno, "Can't open current working directory.");
229 		return(exit_val);
230 	}
231 
232 	/*
233 	 * Where should we put temporary files?
234 	 */
235 	if ((tmpdir = getenv("TMPDIR")) == NULL || *tmpdir == '\0')
236 		tmpdir = _PATH_TMP;
237 	tdlen = strlen(tmpdir);
238 	while (tdlen > 0 && tmpdir[tdlen - 1] == '/')
239 		tdlen--;
240 	tempfile = malloc(tdlen + 1 + sizeof(_TFILE_BASE));
241 	if (tempfile == NULL) {
242 		paxwarn(1, "Cannot allocate memory for temp file name.");
243 		return(exit_val);
244 	}
245 	if (tdlen)
246 		memcpy(tempfile, tmpdir, tdlen);
247 	tempbase = tempfile + tdlen;
248 	*tempbase++ = '/';
249 
250 	/*
251 	 * parse options, determine operational mode, general init
252 	 */
253 	options(argc, argv);
254 	if ((gen_init() < 0) || (tty_init() < 0))
255 		return(exit_val);
256 
257 	/*
258 	 * select a primary operation mode
259 	 */
260 	switch (act) {
261 	case EXTRACT:
262 		extract();
263 		break;
264 	case ARCHIVE:
265 		archive();
266 		break;
267 	case APPND:
268 		if (gzip_program != NULL)
269 			err(1, "can not gzip while appending");
270 		append();
271 		break;
272 	case COPY:
273 		copy();
274 		break;
275 	default:
276 	case LIST:
277 		list();
278 		break;
279 	}
280 	return(exit_val);
281 }
282 
283 /*
284  * sig_cleanup()
285  *	when interrupted we try to do whatever delayed processing we can.
286  *	This is not critical, but we really ought to limit our damage when we
287  *	are aborted by the user.
288  * Return:
289  *	never....
290  */
291 
292 void
293 sig_cleanup(int which_sig)
294 {
295 	/*
296 	 * restore modes and times for any dirs we may have created
297 	 * or any dirs we may have read. Set vflag and vfpart so the user
298 	 * will clearly see the message on a line by itself.
299 	 */
300 	vflag = vfpart = 1;
301 	if (which_sig == SIGXCPU)
302 		paxwarn(0, "Cpu time limit reached, cleaning up.");
303 	else
304 		paxwarn(0, "Signal caught, cleaning up.");
305 
306 	ar_close();
307 	proc_dir();
308 	if (tflag)
309 		atdir_end();
310 	exit(1);
311 }
312 
313 /*
314  * setup_sig()
315  *	set a signal to be caught, but only if it isn't being ignored already
316  */
317 
318 static int
319 setup_sig(int sig, const struct sigaction *n_hand)
320 {
321 	struct sigaction o_hand;
322 
323 	if (sigaction(sig, NULL, &o_hand) < 0)
324 		return (-1);
325 
326 	if (o_hand.sa_handler == SIG_IGN)
327 		return (0);
328 
329 	return (sigaction(sig, n_hand, NULL));
330 }
331 
332 /*
333  * gen_init()
334  *	general setup routines. Not all are required, but they really help
335  *	when dealing with a medium to large sized archives.
336  */
337 
338 static int
339 gen_init(void)
340 {
341 	struct rlimit reslimit;
342 	struct sigaction n_hand;
343 
344 	/*
345 	 * Really needed to handle large archives. We can run out of memory for
346 	 * internal tables really fast when we have a whole lot of files...
347 	 */
348 	if (getrlimit(RLIMIT_DATA , &reslimit) == 0){
349 		reslimit.rlim_cur = reslimit.rlim_max;
350 		(void)setrlimit(RLIMIT_DATA , &reslimit);
351 	}
352 
353 	/*
354 	 * should file size limits be waived? if the os limits us, this is
355 	 * needed if we want to write a large archive
356 	 */
357 	if (getrlimit(RLIMIT_FSIZE , &reslimit) == 0){
358 		reslimit.rlim_cur = reslimit.rlim_max;
359 		(void)setrlimit(RLIMIT_FSIZE , &reslimit);
360 	}
361 
362 	/*
363 	 * increase the size the stack can grow to
364 	 */
365 	if (getrlimit(RLIMIT_STACK , &reslimit) == 0){
366 		reslimit.rlim_cur = reslimit.rlim_max;
367 		(void)setrlimit(RLIMIT_STACK , &reslimit);
368 	}
369 
370 	/*
371 	 * not really needed, but doesn't hurt
372 	 */
373 	if (getrlimit(RLIMIT_RSS , &reslimit) == 0){
374 		reslimit.rlim_cur = reslimit.rlim_max;
375 		(void)setrlimit(RLIMIT_RSS , &reslimit);
376 	}
377 
378 	/*
379 	 * signal handling to reset stored directory times and modes. Since
380 	 * we deal with broken pipes via failed writes we ignore it. We also
381 	 * deal with any file size limit through failed writes. Cpu time
382 	 * limits are caught and a cleanup is forced.
383 	 */
384 	if ((sigemptyset(&s_mask) < 0) || (sigaddset(&s_mask, SIGTERM) < 0) ||
385 	    (sigaddset(&s_mask,SIGINT) < 0)||(sigaddset(&s_mask,SIGHUP) < 0) ||
386 	    (sigaddset(&s_mask,SIGPIPE) < 0)||(sigaddset(&s_mask,SIGQUIT)<0) ||
387 	    (sigaddset(&s_mask,SIGXCPU) < 0)||(sigaddset(&s_mask,SIGXFSZ)<0)) {
388 		paxwarn(1, "Unable to set up signal mask");
389 		return(-1);
390 	}
391 	memset(&n_hand, 0, sizeof n_hand);
392 	n_hand.sa_mask = s_mask;
393 	n_hand.sa_flags = 0;
394 	n_hand.sa_handler = sig_cleanup;
395 
396 	if (setup_sig(SIGHUP,  &n_hand) ||
397 	   setup_sig(SIGTERM, &n_hand) ||
398 	   setup_sig(SIGINT,  &n_hand) ||
399 	   setup_sig(SIGQUIT, &n_hand) ||
400 	   setup_sig(SIGXCPU, &n_hand))
401 		goto out;
402 
403 	n_hand.sa_handler = SIG_IGN;
404 	if ((sigaction(SIGPIPE, &n_hand, NULL) < 0) ||
405 	    (sigaction(SIGXFSZ, &n_hand, NULL) < 0))
406 		goto out;
407 	return(0);
408 
409     out:
410 	syswarn(1, errno, "Unable to set up signal handler");
411 	return(-1);
412 }
413