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#include <sys/param.h>
33#include <sys/stat.h>
34#include <sys/time.h>
35
36#include <err.h>
37#include <errno.h>
38#include <fcntl.h>
39#include <stdarg.h>
40#include <stdio.h>
41#include <stdlib.h>
42#include <string.h>
43#include <unistd.h>
44
45#include "zopen.h"
46
47static void	compress(const char *, const char *, int);
48static void	cwarn(const char *, ...) __printflike(1, 2);
49static void	cwarnx(const char *, ...) __printflike(1, 2);
50static void	decompress(const char *, const char *, int);
51static int	permission(const char *);
52static void	setfile(const char *, struct stat *);
53static void	usage(int);
54
55static int eval, force, verbose;
56
57int
58main(int argc, char *argv[])
59{
60	enum {COMPRESS, DECOMPRESS} style;
61	size_t len;
62	int bits, cat, ch;
63	char *p, newname[MAXPATHLEN];
64
65	cat = 0;
66	if ((p = strrchr(argv[0], '/')) == NULL)
67		p = argv[0];
68	else
69		++p;
70	if (!strcmp(p, "uncompress"))
71		style = DECOMPRESS;
72	else if (!strcmp(p, "compress"))
73		style = COMPRESS;
74	else if (!strcmp(p, "zcat")) {
75		cat = 1;
76		style = DECOMPRESS;
77	} else
78		errx(1, "unknown program name");
79
80	bits = 0;
81	while ((ch = getopt(argc, argv, "b:cdfv")) != -1)
82		switch(ch) {
83		case 'b':
84			bits = strtol(optarg, &p, 10);
85			if (*p)
86				errx(1, "illegal bit count -- %s", optarg);
87			break;
88		case 'c':
89			cat = 1;
90			break;
91		case 'd':		/* Backward compatible. */
92			style = DECOMPRESS;
93			break;
94		case 'f':
95			force = 1;
96			break;
97		case 'v':
98			verbose = 1;
99			break;
100		case '?':
101		default:
102			usage(style == COMPRESS);
103		}
104	argc -= optind;
105	argv += optind;
106
107	if (argc == 0) {
108		switch(style) {
109		case COMPRESS:
110			(void)compress("/dev/stdin", "/dev/stdout", bits);
111			break;
112		case DECOMPRESS:
113			(void)decompress("/dev/stdin", "/dev/stdout", bits);
114			break;
115		}
116		exit (eval);
117	}
118
119	if (cat == 1 && style == COMPRESS && argc > 1)
120		errx(1, "the -c option permits only a single file argument");
121
122	for (; *argv; ++argv)
123		switch(style) {
124		case COMPRESS:
125			if (strcmp(*argv, "-") == 0) {
126				compress("/dev/stdin", "/dev/stdout", bits);
127				break;
128			} else if (cat) {
129				compress(*argv, "/dev/stdout", bits);
130				break;
131			}
132			if ((p = strrchr(*argv, '.')) != NULL &&
133			    !strcmp(p, ".Z")) {
134				cwarnx("%s: name already has trailing .Z",
135				    *argv);
136				break;
137			}
138			len = strlen(*argv);
139			if (len > sizeof(newname) - 3) {
140				cwarnx("%s: name too long", *argv);
141				break;
142			}
143			memmove(newname, *argv, len);
144			newname[len] = '.';
145			newname[len + 1] = 'Z';
146			newname[len + 2] = '\0';
147			compress(*argv, newname, bits);
148			break;
149		case DECOMPRESS:
150			if (strcmp(*argv, "-") == 0) {
151				decompress("/dev/stdin", "/dev/stdout", bits);
152				break;
153			}
154			len = strlen(*argv);
155			if ((p = strrchr(*argv, '.')) == NULL ||
156			    strcmp(p, ".Z")) {
157				if (len > sizeof(newname) - 3) {
158					cwarnx("%s: name too long", *argv);
159					break;
160				}
161				memmove(newname, *argv, len);
162				newname[len] = '.';
163				newname[len + 1] = 'Z';
164				newname[len + 2] = '\0';
165				decompress(newname,
166				    cat ? "/dev/stdout" : *argv, bits);
167			} else {
168				if (len - 2 > sizeof(newname) - 1) {
169					cwarnx("%s: name too long", *argv);
170					break;
171				}
172				memmove(newname, *argv, len - 2);
173				newname[len - 2] = '\0';
174				decompress(*argv,
175				    cat ? "/dev/stdout" : newname, bits);
176			}
177			break;
178		}
179	exit (eval);
180}
181
182static void
183compress(const char *in, const char *out, int bits)
184{
185	size_t nr;
186	struct stat isb, sb;
187	FILE *ifp, *ofp;
188	int exists, isreg, oreg;
189	u_char buf[1024];
190
191	exists = !stat(out, &sb);
192	if (!force && exists && S_ISREG(sb.st_mode) && !permission(out))
193		return;
194	isreg = oreg = !exists || S_ISREG(sb.st_mode);
195
196	ifp = ofp = NULL;
197	if ((ifp = fopen(in, "r")) == NULL) {
198		cwarn("%s", in);
199		return;
200	}
201	if (stat(in, &isb)) {		/* DON'T FSTAT! */
202		cwarn("%s", in);
203		goto err;
204	}
205	if (!S_ISREG(isb.st_mode))
206		isreg = 0;
207
208	if ((ofp = zopen(out, "w", bits)) == NULL) {
209		cwarn("%s", out);
210		goto err;
211	}
212	while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
213		if (fwrite(buf, 1, nr, ofp) != nr) {
214			cwarn("%s", out);
215			goto err;
216		}
217
218	if (ferror(ifp) || fclose(ifp)) {
219		cwarn("%s", in);
220		goto err;
221	}
222	ifp = NULL;
223
224	if (fclose(ofp)) {
225		cwarn("%s", out);
226		goto err;
227	}
228	ofp = NULL;
229
230	if (isreg) {
231		if (stat(out, &sb)) {
232			cwarn("%s", out);
233			goto err;
234		}
235
236		if (!force && sb.st_size >= isb.st_size) {
237			if (verbose)
238		(void)fprintf(stderr, "%s: file would grow; left unmodified\n",
239		    in);
240			eval = 2;
241			if (unlink(out))
242				cwarn("%s", out);
243			goto err;
244		}
245
246		setfile(out, &isb);
247
248		if (unlink(in))
249			cwarn("%s", in);
250
251		if (verbose) {
252			(void)fprintf(stderr, "%s: ", out);
253			if (isb.st_size > sb.st_size)
254				(void)fprintf(stderr, "%.0f%% compression\n",
255				    ((float)sb.st_size / isb.st_size) * 100.0);
256			else
257				(void)fprintf(stderr, "%.0f%% expansion\n",
258				    ((float)isb.st_size / sb.st_size) * 100.0);
259		}
260	}
261	return;
262
263err:	if (ofp) {
264		if (oreg)
265			(void)unlink(out);
266		(void)fclose(ofp);
267	}
268	if (ifp)
269		(void)fclose(ifp);
270}
271
272static void
273decompress(const char *in, const char *out, int bits)
274{
275	size_t nr;
276	struct stat sb;
277	FILE *ifp, *ofp;
278	int exists, isreg, oreg;
279	u_char buf[1024];
280
281	exists = !stat(out, &sb);
282	if (!force && exists && S_ISREG(sb.st_mode) && !permission(out))
283		return;
284	isreg = oreg = !exists || S_ISREG(sb.st_mode);
285
286	ifp = ofp = NULL;
287	if ((ifp = zopen(in, "r", bits)) == NULL) {
288		cwarn("%s", in);
289		return;
290	}
291	if (stat(in, &sb)) {
292		cwarn("%s", in);
293		goto err;
294	}
295	if (!S_ISREG(sb.st_mode))
296		isreg = 0;
297
298	/*
299	 * Try to read the first few uncompressed bytes from the input file
300	 * before blindly truncating the output file.
301	 */
302	if ((nr = fread(buf, 1, sizeof(buf), ifp)) == 0) {
303		cwarn("%s", in);
304		(void)fclose(ifp);
305		return;
306	}
307	if ((ofp = fopen(out, "w")) == NULL ||
308	    (nr != 0 && fwrite(buf, 1, nr, ofp) != nr)) {
309		cwarn("%s", out);
310		if (ofp)
311			(void)fclose(ofp);
312		(void)fclose(ifp);
313		return;
314	}
315
316	while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
317		if (fwrite(buf, 1, nr, ofp) != nr) {
318			cwarn("%s", out);
319			goto err;
320		}
321
322	if (ferror(ifp) || fclose(ifp)) {
323		cwarn("%s", in);
324		goto err;
325	}
326	ifp = NULL;
327
328	if (fclose(ofp)) {
329		cwarn("%s", out);
330		goto err;
331	}
332
333	if (isreg) {
334		setfile(out, &sb);
335
336		if (unlink(in))
337			cwarn("%s", in);
338	}
339	return;
340
341err:	if (ofp) {
342		if (oreg)
343			(void)unlink(out);
344		(void)fclose(ofp);
345	}
346	if (ifp)
347		(void)fclose(ifp);
348}
349
350static void
351setfile(const char *name, struct stat *fs)
352{
353	static struct timespec tspec[2];
354
355	fs->st_mode &= S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO;
356
357	tspec[0] = fs->st_atim;
358	tspec[1] = fs->st_mtim;
359	if (utimensat(AT_FDCWD, name, tspec, 0))
360		cwarn("utimensat: %s", name);
361
362	/*
363	 * Changing the ownership probably won't succeed, unless we're root
364	 * or POSIX_CHOWN_RESTRICTED is not set.  Set uid/gid before setting
365	 * the mode; current BSD behavior is to remove all setuid bits on
366	 * chown.  If chown fails, lose setuid/setgid bits.
367	 */
368	if (chown(name, fs->st_uid, fs->st_gid)) {
369		if (errno != EPERM)
370			cwarn("chown: %s", name);
371		fs->st_mode &= ~(S_ISUID|S_ISGID);
372	}
373	if (chmod(name, fs->st_mode) && errno != EOPNOTSUPP)
374		cwarn("chmod: %s", name);
375
376	if (chflags(name, fs->st_flags) && errno != EOPNOTSUPP)
377		cwarn("chflags: %s", name);
378}
379
380static int
381permission(const char *fname)
382{
383	int ch, first;
384
385	if (!isatty(fileno(stderr)))
386		return (0);
387	(void)fprintf(stderr, "overwrite %s? ", fname);
388	first = ch = getchar();
389	while (ch != '\n' && ch != EOF)
390		ch = getchar();
391	return (first == 'y');
392}
393
394static void
395usage(int iscompress)
396{
397	if (iscompress)
398		(void)fprintf(stderr,
399		    "usage: compress [-cfv] [-b bits] [file ...]\n");
400	else
401		(void)fprintf(stderr,
402		    "usage: uncompress [-c] [-b bits] [file ...]\n");
403	exit(1);
404}
405
406static void
407cwarnx(const char *fmt, ...)
408{
409	va_list ap;
410
411	va_start(ap, fmt);
412	vwarnx(fmt, ap);
413	va_end(ap);
414	eval = 1;
415}
416
417static void
418cwarn(const char *fmt, ...)
419{
420	va_list ap;
421
422	va_start(ap, fmt);
423	vwarn(fmt, ap);
424	va_end(ap);
425	eval = 1;
426}
427