xref: /dragonfly/bin/pax/pax.c (revision 2b3f93ea)
1 /*-
2  * Copyright (c) 1992 Keith Muller.
3  * Copyright (c) 1992, 1993
4  *	The Regents of the University of California.  All rights reserved.
5  *
6  * This code is derived from software contributed to Berkeley by
7  * Keith Muller of the University of California, San Diego.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * @(#) Copyright (c) 1992, 1993 The Regents of the University of California.  All rights reserved.
34  * @(#)pax.c	8.2 (Berkeley) 4/18/94
35  * $FreeBSD: src/bin/pax/pax.c,v 1.13.2.4 2002/11/07 15:29:53 imp Exp $
36  */
37 
38 #include <sys/types.h>
39 #include <sys/stat.h>
40 #include <sys/time.h>
41 #include <sys/resource.h>
42 #include <err.h>
43 #include <errno.h>
44 #include <fcntl.h>
45 #include <locale.h>
46 #include <paths.h>
47 #include <signal.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <unistd.h>
52 #include "pax.h"
53 #include "extern.h"
54 static int gen_init(void);
55 
56 /*
57  * PAX main routines, general globals and some simple start up routines
58  */
59 
60 /*
61  * Variables that can be accessed by any routine within pax
62  */
63 int	act = DEFOP;		/* read/write/append/copy */
64 FSUB	*frmt = NULL;		/* archive format type */
65 int	cflag;			/* match all EXCEPT pattern/file */
66 int	cwdfd;			/* starting cwd */
67 int	dflag;			/* directory member match only  */
68 int	iflag;			/* interactive file/archive rename */
69 int	kflag;			/* do not overwrite existing files */
70 int	lflag;			/* use hard links when possible */
71 int	nflag;			/* select first archive member match */
72 int	tflag;			/* restore access time after read */
73 int	uflag;			/* ignore older modification time files */
74 int	vflag;			/* produce verbose output */
75 int	Dflag;			/* same as uflag except inode change time */
76 int	Hflag;			/* follow command line symlinks (write only) */
77 int	Lflag;			/* follow symlinks when writing */
78 int	Xflag;			/* archive files with same device id only */
79 int	Yflag;			/* same as Dflag except after name mode */
80 int	Zflag;			/* same as uflag except after name mode */
81 int	vfpart;			/* is partial verbose output in progress */
82 int	patime = 1;		/* preserve file access time */
83 int	pmtime = 1;		/* preserve file modification times */
84 int	nodirs;			/* do not create directories as needed */
85 int	pmode;			/* preserve file mode bits */
86 int	pids;			/* preserve file uid/gid */
87 int	rmleadslash = 0;	/* remove leading '/' from pathnames */
88 int	exit_val;		/* exit value */
89 int	docrc;			/* check/create file crc */
90 char	*dirptr;		/* destination dir in a copy */
91 char	*argv0;			/* root of argv[0] */
92 sigset_t s_mask;		/* signal mask for cleanup critical sect */
93 FILE	*listf;			/* file pointer to print file list to */
94 char	*tempfile;		/* tempfile to use for mkstemp(3) */
95 char	*tempbase;		/* basename of tempfile to use for mkstemp(3) */
96 
97 /*
98  *	PAX - Portable Archive Interchange
99  *
100  *	A utility to read, write, and write lists of the members of archive
101  *	files and copy directory hierarchies. A variety of archive formats
102  *	are supported (some are described in POSIX 1003.1 10.1):
103  *
104  *		ustar - 10.1.1 extended tar interchange format
105  *		cpio  - 10.1.2 extended cpio interchange format
106  *		tar - old BSD 4.3 tar format
107  *		binary cpio - old cpio with binary header format
108  *		sysVR4 cpio -  with and without CRC
109  *
110  * This version is a superset of IEEE Std 1003.2b-d3
111  *
112  * Summary of Extensions to the IEEE Standard:
113  *
114  * 1	READ ENHANCEMENTS
115  * 1.1	Operations which read archives will continue to operate even when
116  *	processing archives which may be damaged, truncated, or fail to meet
117  *	format specs in several different ways. Damaged sections of archives
118  *	are detected and avoided if possible. Attempts will be made to resync
119  *	archive read operations even with badly damaged media.
120  * 1.2	Blocksize requirements are not strictly enforced on archive read.
121  *	Tapes which have variable sized records can be read without errors.
122  * 1.3	The user can specify via the non-standard option flag -E if error
123  *	resync operation should stop on a media error, try a specified number
124  *	of times to correct, or try to correct forever.
125  * 1.4	Sparse files (lseek holes) stored on the archive (but stored with blocks
126  *	of all zeros will be restored with holes appropriate for the target
127  *	filesystem
128  * 1.5	The user is notified whenever something is found during archive
129  *	read operations which violates spec (but the read will continue).
130  * 1.6	Multiple archive volumes can be read and may span over different
131  *	archive devices
132  * 1.7	Rigidly restores all file attributes exactly as they are stored on the
133  *	archive.
134  * 1.8	Modification change time ranges can be specified via multiple -T
135  *	options. These allow a user to select files whose modification time
136  *	lies within a specific time range.
137  * 1.9	Files can be selected based on owner (user name or uid) via one or more
138  *	-U options.
139  * 1.10	Files can be selected based on group (group name or gid) via one o
140  *	more -G options.
141  * 1.11	File modification time can be checked against existing file after
142  *	name modification (-Z)
143  *
144  * 2	WRITE ENHANCEMENTS
145  * 2.1	Write operation will stop instead of allowing a user to create a flawed
146  *	flawed archive (due to any problem).
147  * 2.2	Archives written by pax are forced to strictly conform to both the
148  *	archive and pax the specific format specifications.
149  * 2.3	Blocking size and format is rigidly enforced on writes.
150  * 2.4	Formats which may exhibit header overflow problems (they have fields
151  *	too small for large file systems, such as inode number storage), use
152  *	routines designed to repair this problem. These techniques still
153  *	conform to both pax and format specifications, but no longer truncate
154  *	these fields. This removes any restrictions on using these archive
155  *	formats on large file systems.
156  * 2.5	Multiple archive volumes can be written and may span over different
157  *	archive devices
158  * 2.6	A archive volume record limit allows the user to specify the number
159  *	of bytes stored on an archive volume. When reached the user is
160  *	prompted for the next archive volume. This is specified with the
161  *	non-standard -B flag. The limit is rounded up to the next blocksize.
162  * 2.7	All archive padding during write use zero filled sections. This makes
163  *	it much easier to pull data out of flawed archive during read
164  *	operations.
165  * 2.8	Access time reset with the -t applies to all file nodes (including
166  *	directories).
167  * 2.9	Symbolic links can be followed with -L (optional in the spec).
168  * 2.10	Modification or inode change time ranges can be specified via
169  *	multiple -T options. These allow a user to select files whose
170  *	modification or inode change time lies within a specific time range.
171  * 2.11	Files can be selected based on owner (user name or uid) via one or more
172  *	-U options.
173  * 2.12	Files can be selected based on group (group name or gid) via one o
174  *	more -G options.
175  * 2.13	Symlinks which appear on the command line can be followed (without
176  *	following other symlinks; -H flag)
177  *
178  * 3	COPY ENHANCEMENTS
179  * 3.1	Sparse files (lseek holes) can be copied without expanding the holes
180  *	into zero filled blocks. The file copy is created with holes which are
181  *	appropriate for the target filesystem
182  * 3.2	Access time as well as modification time on copied file trees can be
183  *	preserved with the appropriate -p options.
184  * 3.3	Access time reset with the -t applies to all file nodes (including
185  *	directories).
186  * 3.4	Symbolic links can be followed with -L (optional in the spec).
187  * 3.5	Modification or inode change time ranges can be specified via
188  *	multiple -T options. These allow a user to select files whose
189  *	modification or inode change time lies within a specific time range.
190  * 3.6	Files can be selected based on owner (user name or uid) via one or more
191  *	-U options.
192  * 3.7	Files can be selected based on group (group name or gid) via one o
193  *	more -G options.
194  * 3.8	Symlinks which appear on the command line can be followed (without
195  *	following other symlinks; -H flag)
196  * 3.9  File inode change time can be checked against existing file before
197  *	name modification (-D)
198  * 3.10 File inode change time can be checked against existing file after
199  *	name modification (-Y)
200  * 3.11	File modification time can be checked against existing file after
201  *	name modification (-Z)
202  *
203  * 4	GENERAL ENHANCEMENTS
204  * 4.1	Internal structure is designed to isolate format dependent and
205  *	independent functions. Formats are selected via a format driver table.
206  *	This encourages the addition of new archive formats by only having to
207  *	write those routines which id, read and write the archive header.
208  */
209 
210 /*
211  * main()
212  *	parse options, set up and operate as specified by the user.
213  *	any operational flaw will set exit_val to non-zero
214  * Return: 0 if ok, 1 otherwise
215  */
216 
217 int
218 main(int argc, char *argv[])
219 {
220 	const char *tmpdir;
221 	size_t tdlen;
222 
223 	setlocale(LC_ALL, "");
224 	listf = stderr;
225 	/*
226 	 * Keep a reference to cwd, so we can always come back home.
227 	 */
228 	cwdfd = open(".", O_RDONLY | O_CLOEXEC);
229 	if (cwdfd < 0) {
230 		syswarn(0, errno, "Can't open current working directory.");
231 		return(exit_val);
232 	}
233 
234 	/*
235 	 * Where should we put temporary files?
236 	 */
237 	if ((tmpdir = getenv("TMPDIR")) == NULL || *tmpdir == '\0')
238 		tmpdir = _PATH_TMP;
239 	tdlen = strlen(tmpdir);
240 	while (tdlen > 0 && tmpdir[tdlen - 1] == '/')
241 		tdlen--;
242 	tempfile = malloc(tdlen + 1 + sizeof(_TFILE_BASE));
243 	if (tempfile == NULL) {
244 		paxwarn(1, "Cannot allocate memory for temp file name.");
245 		return(exit_val);
246 	}
247 	if (tdlen)
248 		memcpy(tempfile, tmpdir, tdlen);
249 	tempbase = tempfile + tdlen;
250 	*tempbase++ = '/';
251 
252 	/*
253 	 * parse options, determine operational mode, general init
254 	 */
255 	options(argc, argv);
256 	if ((gen_init() < 0) || (tty_init() < 0))
257 		return(exit_val);
258 
259 	/*
260 	 * select a primary operation mode
261 	 */
262 	switch (act) {
263 	case EXTRACT:
264 		extract();
265 		break;
266 	case ARCHIVE:
267 		archive();
268 		break;
269 	case APPND:
270 		if (gzip_program != NULL)
271 			err(1, "can not gzip while appending");
272 		append();
273 		break;
274 	case COPY:
275 		copy();
276 		break;
277 	default:
278 	case LIST:
279 		list();
280 		break;
281 	}
282 	return(exit_val);
283 }
284 
285 /*
286  * sig_cleanup()
287  *	when interrupted we try to do whatever delayed processing we can.
288  *	This is not critical, but we really ought to limit our damage when we
289  *	are aborted by the user.
290  * Return:
291  *	never....
292  */
293 
294 void
295 sig_cleanup(int which_sig)
296 {
297 	/*
298 	 * restore modes and times for any dirs we may have created
299 	 * or any dirs we may have read. Set vflag and vfpart so the user
300 	 * will clearly see the message on a line by itself.
301 	 */
302 	vflag = vfpart = 1;
303 	if (which_sig == SIGXCPU)
304 		paxwarn(0, "Cpu time limit reached, cleaning up.");
305 	else
306 		paxwarn(0, "Signal caught, cleaning up.");
307 
308 	ar_close();
309 	proc_dir();
310 	if (tflag)
311 		atdir_end();
312 	exit(1);
313 }
314 
315 /*
316  * setup_sig()
317  *	set a signal to be caught, but only if it isn't being ignored already
318  */
319 
320 static int
321 setup_sig(int sig, const struct sigaction *n_hand)
322 {
323 	struct sigaction o_hand;
324 
325 	if (sigaction(sig, NULL, &o_hand) < 0)
326 		return (-1);
327 
328 	if (o_hand.sa_handler == SIG_IGN)
329 		return (0);
330 
331 	return (sigaction(sig, n_hand, NULL));
332 }
333 
334 /*
335  * gen_init()
336  *	general setup routines. Not all are required, but they really help
337  *	when dealing with a medium to large sized archives.
338  */
339 
340 static int
341 gen_init(void)
342 {
343 	struct rlimit reslimit;
344 	struct sigaction n_hand;
345 
346 	/*
347 	 * Really needed to handle large archives. We can run out of memory for
348 	 * internal tables really fast when we have a whole lot of files...
349 	 */
350 	if (getrlimit(RLIMIT_DATA , &reslimit) == 0){
351 		reslimit.rlim_cur = reslimit.rlim_max;
352 		setrlimit(RLIMIT_DATA , &reslimit);
353 	}
354 
355 	/*
356 	 * should file size limits be waived? if the os limits us, this is
357 	 * needed if we want to write a large archive
358 	 */
359 	if (getrlimit(RLIMIT_FSIZE , &reslimit) == 0){
360 		reslimit.rlim_cur = reslimit.rlim_max;
361 		setrlimit(RLIMIT_FSIZE , &reslimit);
362 	}
363 
364 	/*
365 	 * increase the size the stack can grow to
366 	 */
367 	if (getrlimit(RLIMIT_STACK , &reslimit) == 0){
368 		reslimit.rlim_cur = reslimit.rlim_max;
369 		setrlimit(RLIMIT_STACK , &reslimit);
370 	}
371 
372 	/*
373 	 * not really needed, but doesn't hurt
374 	 */
375 	if (getrlimit(RLIMIT_RSS , &reslimit) == 0){
376 		reslimit.rlim_cur = reslimit.rlim_max;
377 		setrlimit(RLIMIT_RSS , &reslimit);
378 	}
379 
380 	/*
381 	 * signal handling to reset stored directory times and modes. Since
382 	 * we deal with broken pipes via failed writes we ignore it. We also
383 	 * deal with any file size limit through failed writes. Cpu time
384 	 * limits are caught and a cleanup is forced.
385 	 */
386 	if ((sigemptyset(&s_mask) < 0) || (sigaddset(&s_mask, SIGTERM) < 0) ||
387 	    (sigaddset(&s_mask,SIGINT) < 0)||(sigaddset(&s_mask,SIGHUP) < 0) ||
388 	    (sigaddset(&s_mask,SIGPIPE) < 0)||(sigaddset(&s_mask,SIGQUIT)<0) ||
389 	    (sigaddset(&s_mask,SIGXCPU) < 0)||(sigaddset(&s_mask,SIGXFSZ)<0)) {
390 		paxwarn(1, "Unable to set up signal mask");
391 		return(-1);
392 	}
393 	memset(&n_hand, 0, sizeof n_hand);
394 	n_hand.sa_mask = s_mask;
395 	n_hand.sa_flags = 0;
396 	n_hand.sa_handler = sig_cleanup;
397 
398 	if (setup_sig(SIGHUP,  &n_hand) ||
399 	    setup_sig(SIGTERM, &n_hand) ||
400 	    setup_sig(SIGINT,  &n_hand) ||
401 	    setup_sig(SIGQUIT, &n_hand) ||
402 	    setup_sig(SIGXCPU, &n_hand))
403 		goto out;
404 
405 	n_hand.sa_handler = SIG_IGN;
406 	if ((sigaction(SIGPIPE, &n_hand, NULL) < 0) ||
407 	    (sigaction(SIGXFSZ, &n_hand, NULL) < 0))
408 		goto out;
409 	return(0);
410 
411     out:
412 	syswarn(1, errno, "Unable to set up signal handler");
413 	return(-1);
414 }
415