xref: /openbsd/usr.bin/patch/util.c (revision 8529ddd3)
1 /*	$OpenBSD: util.c,v 1.39 2015/01/16 06:40:10 deraadt Exp $	*/
2 
3 /*
4  * patch - a program to apply diffs to original files
5  *
6  * Copyright 1986, Larry Wall
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following condition is met:
10  * 1. Redistributions of source code must retain the above copyright notice,
11  * this condition and the following disclaimer.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
15  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
16  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
17  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
19  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
20  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  *
25  * -C option added in 1998, original code by Marc Espie, based on FreeBSD
26  * behaviour
27  */
28 
29 #include <sys/stat.h>
30 
31 #include <ctype.h>
32 #include <errno.h>
33 #include <fcntl.h>
34 #include <libgen.h>
35 #include <paths.h>
36 #include <signal.h>
37 #include <stdarg.h>
38 #include <stdlib.h>
39 #include <stdio.h>
40 #include <string.h>
41 #include <unistd.h>
42 
43 #include "common.h"
44 #include "util.h"
45 #include "backupfile.h"
46 #include "pathnames.h"
47 
48 /* Rename a file, copying it if necessary. */
49 
50 int
51 move_file(const char *from, const char *to)
52 {
53 	int	fromfd;
54 	ssize_t	i;
55 
56 	/* to stdout? */
57 
58 	if (strEQ(to, "-")) {
59 #ifdef DEBUGGING
60 		if (debug & 4)
61 			say("Moving %s to stdout.\n", from);
62 #endif
63 		fromfd = open(from, O_RDONLY);
64 		if (fromfd < 0)
65 			pfatal("internal error, can't reopen %s", from);
66 		while ((i = read(fromfd, buf, sizeof buf)) > 0)
67 			if (write(STDOUT_FILENO, buf, i) != i)
68 				pfatal("write failed");
69 		close(fromfd);
70 		return 0;
71 	}
72 	if (backup_file(to) < 0) {
73 		say("Can't backup %s, output is in %s: %s\n", to, from,
74 		    strerror(errno));
75 		return -1;
76 	}
77 #ifdef DEBUGGING
78 	if (debug & 4)
79 		say("Moving %s to %s.\n", from, to);
80 #endif
81 	if (rename(from, to) < 0) {
82 		if (errno != EXDEV || copy_file(from, to) < 0) {
83 			say("Can't create %s, output is in %s: %s\n",
84 			    to, from, strerror(errno));
85 			return -1;
86 		}
87 	}
88 	return 0;
89 }
90 
91 /* Backup the original file.  */
92 
93 int
94 backup_file(const char *orig)
95 {
96 	struct stat	filestat;
97 	char		bakname[PATH_MAX], *s, *simplename;
98 	dev_t		orig_device;
99 	ino_t		orig_inode;
100 
101 	if (backup_type == none || stat(orig, &filestat) != 0)
102 		return 0;			/* nothing to do */
103 	orig_device = filestat.st_dev;
104 	orig_inode = filestat.st_ino;
105 
106 	if (origprae) {
107 		if (strlcpy(bakname, origprae, sizeof(bakname)) >= sizeof(bakname) ||
108 		    strlcat(bakname, orig, sizeof(bakname)) >= sizeof(bakname))
109 			fatal("filename %s too long for buffer\n", origprae);
110 	} else {
111 		if ((s = find_backup_file_name(orig)) == NULL)
112 			fatal("out of memory\n");
113 		if (strlcpy(bakname, s, sizeof(bakname)) >= sizeof(bakname))
114 			fatal("filename %s too long for buffer\n", s);
115 		free(s);
116 	}
117 
118 	if ((simplename = strrchr(bakname, '/')) != NULL)
119 		simplename = simplename + 1;
120 	else
121 		simplename = bakname;
122 
123 	/*
124 	 * Find a backup name that is not the same file. Change the
125 	 * first lowercase char into uppercase; if that isn't
126 	 * sufficient, chop off the first char and try again.
127 	 */
128 	while (stat(bakname, &filestat) == 0 &&
129 	    orig_device == filestat.st_dev && orig_inode == filestat.st_ino) {
130 		/* Skip initial non-lowercase chars.  */
131 		for (s = simplename; *s && !islower((unsigned char)*s); s++)
132 			;
133 		if (*s)
134 			*s = toupper((unsigned char)*s);
135 		else
136 			memmove(simplename, simplename + 1,
137 			    strlen(simplename + 1) + 1);
138 	}
139 #ifdef DEBUGGING
140 	if (debug & 4)
141 		say("Moving %s to %s.\n", orig, bakname);
142 #endif
143 	if (rename(orig, bakname) < 0) {
144 		if (errno != EXDEV || copy_file(orig, bakname) < 0)
145 			return -1;
146 	}
147 	return 0;
148 }
149 
150 /*
151  * Copy a file.
152  */
153 int
154 copy_file(const char *from, const char *to)
155 {
156 	int	tofd, fromfd;
157 	ssize_t	i;
158 
159 	tofd = open(to, O_CREAT|O_TRUNC|O_WRONLY, 0666);
160 	if (tofd < 0)
161 		return -1;
162 	fromfd = open(from, O_RDONLY, 0);
163 	if (fromfd < 0)
164 		pfatal("internal error, can't reopen %s", from);
165 	while ((i = read(fromfd, buf, sizeof buf)) > 0)
166 		if (write(tofd, buf, i) != i)
167 			pfatal("write to %s failed", to);
168 	close(fromfd);
169 	close(tofd);
170 	return 0;
171 }
172 
173 /*
174  * Allocate a unique area for a string.
175  */
176 char *
177 savestr(const char *s)
178 {
179 	char	*rv;
180 
181 	if (!s)
182 		s = "Oops";
183 	rv = strdup(s);
184 	if (rv == NULL) {
185 		if (using_plan_a)
186 			out_of_mem = true;
187 		else
188 			fatal("out of memory\n");
189 	}
190 	return rv;
191 }
192 
193 /*
194  * Allocate a unique area for a string.  Call fatal if out of memory.
195  */
196 char *
197 xstrdup(const char *s)
198 {
199 	char	*rv;
200 
201 	if (!s)
202 		s = "Oops";
203 	rv = strdup(s);
204 	if (rv == NULL)
205 		fatal("out of memory\n");
206 	return rv;
207 }
208 
209 /*
210  * Vanilla terminal output (buffered).
211  */
212 void
213 say(const char *fmt, ...)
214 {
215 	va_list	ap;
216 
217 	va_start(ap, fmt);
218 	vfprintf(stdout, fmt, ap);
219 	va_end(ap);
220 	fflush(stdout);
221 }
222 
223 /*
224  * Terminal output, pun intended.
225  */
226 void
227 fatal(const char *fmt, ...)
228 {
229 	va_list	ap;
230 
231 	va_start(ap, fmt);
232 	fprintf(stderr, "patch: **** ");
233 	vfprintf(stderr, fmt, ap);
234 	va_end(ap);
235 	my_exit(2);
236 }
237 
238 /*
239  * Say something from patch, something from the system, then silence . . .
240  */
241 void
242 pfatal(const char *fmt, ...)
243 {
244 	va_list	ap;
245 	int	errnum = errno;
246 
247 	fprintf(stderr, "patch: **** ");
248 	va_start(ap, fmt);
249 	vfprintf(stderr, fmt, ap);
250 	va_end(ap);
251 	fprintf(stderr, ": %s\n", strerror(errnum));
252 	my_exit(2);
253 }
254 
255 /*
256  * Get a response from the user via /dev/tty
257  */
258 void
259 ask(const char *fmt, ...)
260 {
261 	va_list	ap;
262 	ssize_t	nr;
263 	static	int ttyfd = -1;
264 
265 	va_start(ap, fmt);
266 	vfprintf(stdout, fmt, ap);
267 	va_end(ap);
268 	fflush(stdout);
269 	if (ttyfd < 0)
270 		ttyfd = open(_PATH_TTY, O_RDONLY);
271 	if (ttyfd >= 0) {
272 		if ((nr = read(ttyfd, buf, sizeof(buf))) > 0 &&
273 		    buf[nr - 1] == '\n')
274 			buf[nr - 1] = '\0';
275 	}
276 	if (ttyfd < 0 || nr <= 0) {
277 		/* no tty or error reading, pretend user entered 'return' */
278 		putchar('\n');
279 		buf[0] = '\0';
280 	}
281 }
282 
283 /*
284  * How to handle certain events when not in a critical region.
285  */
286 void
287 set_signals(int reset)
288 {
289 	static sig_t	hupval, intval;
290 
291 	if (!reset) {
292 		hupval = signal(SIGHUP, SIG_IGN);
293 		if (hupval != SIG_IGN)
294 			hupval = (sig_t) my_exit;
295 		intval = signal(SIGINT, SIG_IGN);
296 		if (intval != SIG_IGN)
297 			intval = (sig_t) my_exit;
298 	}
299 	signal(SIGHUP, hupval);
300 	signal(SIGINT, intval);
301 }
302 
303 /*
304  * How to handle certain events when in a critical region.
305  */
306 void
307 ignore_signals(void)
308 {
309 	signal(SIGHUP, SIG_IGN);
310 	signal(SIGINT, SIG_IGN);
311 }
312 
313 /*
314  * Make sure we'll have the directories to create a file. If `striplast' is
315  * true, ignore the last element of `filename'.
316  */
317 
318 void
319 makedirs(const char *filename, bool striplast)
320 {
321 	char	*tmpbuf;
322 
323 	if ((tmpbuf = strdup(filename)) == NULL)
324 		fatal("out of memory\n");
325 
326 	if (striplast) {
327 		char	*s = strrchr(tmpbuf, '/');
328 		if (s == NULL) {
329 			free(tmpbuf);
330 			return;	/* nothing to be done */
331 		}
332 		*s = '\0';
333 	}
334 	if (mkpath(tmpbuf) != 0)
335 		pfatal("creation of %s failed", tmpbuf);
336 	free(tmpbuf);
337 }
338 
339 /*
340  * Make filenames more reasonable.
341  */
342 char *
343 fetchname(const char *at, bool *exists, int strip_leading)
344 {
345 	char		*fullname, *name, *t;
346 	int		sleading, tab;
347 	struct stat	filestat;
348 
349 	if (at == NULL || *at == '\0')
350 		return NULL;
351 	while (isspace((unsigned char)*at))
352 		at++;
353 #ifdef DEBUGGING
354 	if (debug & 128)
355 		say("fetchname %s %d\n", at, strip_leading);
356 #endif
357 	/* So files can be created by diffing against /dev/null.  */
358 	if (strnEQ(at, _PATH_DEVNULL, sizeof(_PATH_DEVNULL) - 1))
359 		return NULL;
360 	name = fullname = t = savestr(at);
361 
362 	tab = strchr(t, '\t') != NULL;
363 	/* Strip off up to `strip_leading' path components and NUL terminate. */
364 	for (sleading = strip_leading; *t != '\0' && ((tab && *t != '\t') ||
365 	    !isspace((unsigned char)*t)); t++) {
366 		if (t[0] == '/' && t[1] != '/' && t[1] != '\0')
367 			if (--sleading >= 0)
368 				name = t + 1;
369 	}
370 	*t = '\0';
371 
372 	/*
373 	 * If no -p option was given (957 is the default value!), we were
374 	 * given a relative pathname, and the leading directories that we
375 	 * just stripped off all exist, put them back on.
376 	 */
377 	if (strip_leading == 957 && name != fullname && *fullname != '/') {
378 		name[-1] = '\0';
379 		if (stat(fullname, &filestat) == 0 && S_ISDIR(filestat.st_mode)) {
380 			name[-1] = '/';
381 			name = fullname;
382 		}
383 	}
384 	name = savestr(name);
385 	free(fullname);
386 
387 	*exists = stat(name, &filestat) == 0;
388 	return name;
389 }
390 
391 /*
392  * Takes the name returned by fetchname and looks in RCS directory
393  * for a checked in version.
394  */
395 char *
396 checked_in(char *file)
397 {
398 	char		*filebase, *filedir, tmpbuf[PATH_MAX];
399 	struct stat	filestat;
400 
401 	filebase = basename(file);
402 	filedir = dirname(file);
403 
404 #define try(f, a1, a2, a3) \
405 (snprintf(tmpbuf, sizeof tmpbuf, f, a1, a2, a3), stat(tmpbuf, &filestat) == 0)
406 
407 	if (try("%s/RCS/%s%s", filedir, filebase, RCSSUFFIX) ||
408 	    try("%s/RCS/%s%s", filedir, filebase, "") ||
409 	    try("%s/%s%s", filedir, filebase, RCSSUFFIX))
410 		return file;
411 
412 	return NULL;
413 }
414 
415 void
416 version(void)
417 {
418 	fprintf(stderr, "Patch version 2.0-12u8-OpenBSD\n");
419 	my_exit(EXIT_SUCCESS);
420 }
421 
422 /*
423  * Exit with cleanup.
424  */
425 void
426 my_exit(int status)
427 {
428 	unlink(TMPINNAME);
429 	if (!toutkeep)
430 		unlink(TMPOUTNAME);
431 	if (!trejkeep)
432 		unlink(TMPREJNAME);
433 	unlink(TMPPATNAME);
434 	exit(status);
435 }
436