1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1992, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#ifndef lint
33static const char copyright[] =
34"@(#) Copyright (c) 1992, 1993\n\
35	The Regents of the University of California.  All rights reserved.\n";
36#endif
37
38#if 0
39#ifndef lint
40static char sccsid[] = "@(#)compress.c	8.2 (Berkeley) 1/7/94";
41#endif
42#endif
43
44#include <sys/cdefs.h>
45__FBSDID("$FreeBSD$");
46
47#include <sys/param.h>
48#include <sys/stat.h>
49#include <sys/time.h>
50
51#include <err.h>
52#include <errno.h>
53#include <fcntl.h>
54#include <stdarg.h>
55#include <stdio.h>
56#include <stdlib.h>
57#include <string.h>
58#include <unistd.h>
59
60#include "zopen.h"
61
62static void	compress(const char *, const char *, int);
63static void	cwarn(const char *, ...) __printflike(1, 2);
64static void	cwarnx(const char *, ...) __printflike(1, 2);
65static void	decompress(const char *, const char *, int);
66static int	permission(const char *);
67static void	setfile(const char *, struct stat *);
68static void	usage(int);
69
70static int eval, force, verbose;
71
72int
73main(int argc, char *argv[])
74{
75	enum {COMPRESS, DECOMPRESS} style;
76	size_t len;
77	int bits, cat, ch;
78	char *p, newname[MAXPATHLEN];
79
80	cat = 0;
81	if ((p = strrchr(argv[0], '/')) == NULL)
82		p = argv[0];
83	else
84		++p;
85	if (!strcmp(p, "uncompress"))
86		style = DECOMPRESS;
87	else if (!strcmp(p, "compress"))
88		style = COMPRESS;
89	else if (!strcmp(p, "zcat")) {
90		cat = 1;
91		style = DECOMPRESS;
92	} else
93		errx(1, "unknown program name");
94
95	bits = 0;
96	while ((ch = getopt(argc, argv, "b:cdfv")) != -1)
97		switch(ch) {
98		case 'b':
99			bits = strtol(optarg, &p, 10);
100			if (*p)
101				errx(1, "illegal bit count -- %s", optarg);
102			break;
103		case 'c':
104			cat = 1;
105			break;
106		case 'd':		/* Backward compatible. */
107			style = DECOMPRESS;
108			break;
109		case 'f':
110			force = 1;
111			break;
112		case 'v':
113			verbose = 1;
114			break;
115		case '?':
116		default:
117			usage(style == COMPRESS);
118		}
119	argc -= optind;
120	argv += optind;
121
122	if (argc == 0) {
123		switch(style) {
124		case COMPRESS:
125			(void)compress("/dev/stdin", "/dev/stdout", bits);
126			break;
127		case DECOMPRESS:
128			(void)decompress("/dev/stdin", "/dev/stdout", bits);
129			break;
130		}
131		exit (eval);
132	}
133
134	if (cat == 1 && style == COMPRESS && argc > 1)
135		errx(1, "the -c option permits only a single file argument");
136
137	for (; *argv; ++argv)
138		switch(style) {
139		case COMPRESS:
140			if (strcmp(*argv, "-") == 0) {
141				compress("/dev/stdin", "/dev/stdout", bits);
142				break;
143			} else if (cat) {
144				compress(*argv, "/dev/stdout", bits);
145				break;
146			}
147			if ((p = strrchr(*argv, '.')) != NULL &&
148			    !strcmp(p, ".Z")) {
149				cwarnx("%s: name already has trailing .Z",
150				    *argv);
151				break;
152			}
153			len = strlen(*argv);
154			if (len > sizeof(newname) - 3) {
155				cwarnx("%s: name too long", *argv);
156				break;
157			}
158			memmove(newname, *argv, len);
159			newname[len] = '.';
160			newname[len + 1] = 'Z';
161			newname[len + 2] = '\0';
162			compress(*argv, newname, bits);
163			break;
164		case DECOMPRESS:
165			if (strcmp(*argv, "-") == 0) {
166				decompress("/dev/stdin", "/dev/stdout", bits);
167				break;
168			}
169			len = strlen(*argv);
170			if ((p = strrchr(*argv, '.')) == NULL ||
171			    strcmp(p, ".Z")) {
172				if (len > sizeof(newname) - 3) {
173					cwarnx("%s: name too long", *argv);
174					break;
175				}
176				memmove(newname, *argv, len);
177				newname[len] = '.';
178				newname[len + 1] = 'Z';
179				newname[len + 2] = '\0';
180				decompress(newname,
181				    cat ? "/dev/stdout" : *argv, bits);
182			} else {
183				if (len - 2 > sizeof(newname) - 1) {
184					cwarnx("%s: name too long", *argv);
185					break;
186				}
187				memmove(newname, *argv, len - 2);
188				newname[len - 2] = '\0';
189				decompress(*argv,
190				    cat ? "/dev/stdout" : newname, bits);
191			}
192			break;
193		}
194	exit (eval);
195}
196
197static void
198compress(const char *in, const char *out, int bits)
199{
200	size_t nr;
201	struct stat isb, sb;
202	FILE *ifp, *ofp;
203	int exists, isreg, oreg;
204	u_char buf[1024];
205
206	exists = !stat(out, &sb);
207	if (!force && exists && S_ISREG(sb.st_mode) && !permission(out))
208		return;
209	isreg = oreg = !exists || S_ISREG(sb.st_mode);
210
211	ifp = ofp = NULL;
212	if ((ifp = fopen(in, "r")) == NULL) {
213		cwarn("%s", in);
214		return;
215	}
216	if (stat(in, &isb)) {		/* DON'T FSTAT! */
217		cwarn("%s", in);
218		goto err;
219	}
220	if (!S_ISREG(isb.st_mode))
221		isreg = 0;
222
223	if ((ofp = zopen(out, "w", bits)) == NULL) {
224		cwarn("%s", out);
225		goto err;
226	}
227	while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
228		if (fwrite(buf, 1, nr, ofp) != nr) {
229			cwarn("%s", out);
230			goto err;
231		}
232
233	if (ferror(ifp) || fclose(ifp)) {
234		cwarn("%s", in);
235		goto err;
236	}
237	ifp = NULL;
238
239	if (fclose(ofp)) {
240		cwarn("%s", out);
241		goto err;
242	}
243	ofp = NULL;
244
245	if (isreg) {
246		if (stat(out, &sb)) {
247			cwarn("%s", out);
248			goto err;
249		}
250
251		if (!force && sb.st_size >= isb.st_size) {
252			if (verbose)
253		(void)fprintf(stderr, "%s: file would grow; left unmodified\n",
254		    in);
255			eval = 2;
256			if (unlink(out))
257				cwarn("%s", out);
258			goto err;
259		}
260
261		setfile(out, &isb);
262
263		if (unlink(in))
264			cwarn("%s", in);
265
266		if (verbose) {
267			(void)fprintf(stderr, "%s: ", out);
268			if (isb.st_size > sb.st_size)
269				(void)fprintf(stderr, "%.0f%% compression\n",
270				    ((float)sb.st_size / isb.st_size) * 100.0);
271			else
272				(void)fprintf(stderr, "%.0f%% expansion\n",
273				    ((float)isb.st_size / sb.st_size) * 100.0);
274		}
275	}
276	return;
277
278err:	if (ofp) {
279		if (oreg)
280			(void)unlink(out);
281		(void)fclose(ofp);
282	}
283	if (ifp)
284		(void)fclose(ifp);
285}
286
287static void
288decompress(const char *in, const char *out, int bits)
289{
290	size_t nr;
291	struct stat sb;
292	FILE *ifp, *ofp;
293	int exists, isreg, oreg;
294	u_char buf[1024];
295
296	exists = !stat(out, &sb);
297	if (!force && exists && S_ISREG(sb.st_mode) && !permission(out))
298		return;
299	isreg = oreg = !exists || S_ISREG(sb.st_mode);
300
301	ifp = ofp = NULL;
302	if ((ifp = zopen(in, "r", bits)) == NULL) {
303		cwarn("%s", in);
304		return;
305	}
306	if (stat(in, &sb)) {
307		cwarn("%s", in);
308		goto err;
309	}
310	if (!S_ISREG(sb.st_mode))
311		isreg = 0;
312
313	/*
314	 * Try to read the first few uncompressed bytes from the input file
315	 * before blindly truncating the output file.
316	 */
317	if ((nr = fread(buf, 1, sizeof(buf), ifp)) == 0) {
318		cwarn("%s", in);
319		(void)fclose(ifp);
320		return;
321	}
322	if ((ofp = fopen(out, "w")) == NULL ||
323	    (nr != 0 && fwrite(buf, 1, nr, ofp) != nr)) {
324		cwarn("%s", out);
325		if (ofp)
326			(void)fclose(ofp);
327		(void)fclose(ifp);
328		return;
329	}
330
331	while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
332		if (fwrite(buf, 1, nr, ofp) != nr) {
333			cwarn("%s", out);
334			goto err;
335		}
336
337	if (ferror(ifp) || fclose(ifp)) {
338		cwarn("%s", in);
339		goto err;
340	}
341	ifp = NULL;
342
343	if (fclose(ofp)) {
344		cwarn("%s", out);
345		goto err;
346	}
347
348	if (isreg) {
349		setfile(out, &sb);
350
351		if (unlink(in))
352			cwarn("%s", in);
353	}
354	return;
355
356err:	if (ofp) {
357		if (oreg)
358			(void)unlink(out);
359		(void)fclose(ofp);
360	}
361	if (ifp)
362		(void)fclose(ifp);
363}
364
365static void
366setfile(const char *name, struct stat *fs)
367{
368	static struct timespec tspec[2];
369
370	fs->st_mode &= S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO;
371
372	tspec[0] = fs->st_atim;
373	tspec[1] = fs->st_mtim;
374	if (utimensat(AT_FDCWD, name, tspec, 0))
375		cwarn("utimensat: %s", name);
376
377	/*
378	 * Changing the ownership probably won't succeed, unless we're root
379	 * or POSIX_CHOWN_RESTRICTED is not set.  Set uid/gid before setting
380	 * the mode; current BSD behavior is to remove all setuid bits on
381	 * chown.  If chown fails, lose setuid/setgid bits.
382	 */
383	if (chown(name, fs->st_uid, fs->st_gid)) {
384		if (errno != EPERM)
385			cwarn("chown: %s", name);
386		fs->st_mode &= ~(S_ISUID|S_ISGID);
387	}
388	if (chmod(name, fs->st_mode) && errno != EOPNOTSUPP)
389		cwarn("chmod: %s", name);
390
391	if (chflags(name, fs->st_flags) && errno != EOPNOTSUPP)
392		cwarn("chflags: %s", name);
393}
394
395static int
396permission(const char *fname)
397{
398	int ch, first;
399
400	if (!isatty(fileno(stderr)))
401		return (0);
402	(void)fprintf(stderr, "overwrite %s? ", fname);
403	first = ch = getchar();
404	while (ch != '\n' && ch != EOF)
405		ch = getchar();
406	return (first == 'y');
407}
408
409static void
410usage(int iscompress)
411{
412	if (iscompress)
413		(void)fprintf(stderr,
414		    "usage: compress [-cfv] [-b bits] [file ...]\n");
415	else
416		(void)fprintf(stderr,
417		    "usage: uncompress [-c] [-b bits] [file ...]\n");
418	exit(1);
419}
420
421static void
422cwarnx(const char *fmt, ...)
423{
424	va_list ap;
425
426	va_start(ap, fmt);
427	vwarnx(fmt, ap);
428	va_end(ap);
429	eval = 1;
430}
431
432static void
433cwarn(const char *fmt, ...)
434{
435	va_list ap;
436
437	va_start(ap, fmt);
438	vwarn(fmt, ap);
439	va_end(ap);
440	eval = 1;
441}
442