1 /* $OpenBSD: util.c,v 1.46 2021/10/24 21:24:17 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 <paths.h>
35 #include <signal.h>
36 #include <stdarg.h>
37 #include <stdlib.h>
38 #include <stdio.h>
39 #include <string.h>
40 #include <unistd.h>
41
42 #include "common.h"
43 #include "util.h"
44 #include "backupfile.h"
45
46 /* Rename a file, copying it if necessary. */
47
48 int
move_file(const char * from,const char * to)49 move_file(const char *from, const char *to)
50 {
51 int fromfd;
52 ssize_t i;
53
54 /* to stdout? */
55
56 if (strEQ(to, "-")) {
57 #ifdef DEBUGGING
58 if (debug & 4)
59 say("Moving %s to stdout.\n", from);
60 #endif
61 fromfd = open(from, O_RDONLY);
62 if (fromfd == -1)
63 pfatal("internal error, can't reopen %s", from);
64 while ((i = read(fromfd, buf, bufsz)) > 0)
65 if (write(STDOUT_FILENO, buf, i) != i)
66 pfatal("write failed");
67 close(fromfd);
68 return 0;
69 }
70 if (backup_file(to) < 0) {
71 say("Can't backup %s, output is in %s: %s\n", to, from,
72 strerror(errno));
73 return -1;
74 }
75 #ifdef DEBUGGING
76 if (debug & 4)
77 say("Moving %s to %s.\n", from, to);
78 #endif
79 if (rename(from, to) == -1) {
80 if (errno != EXDEV || copy_file(from, to) < 0) {
81 say("Can't create %s, output is in %s: %s\n",
82 to, from, strerror(errno));
83 return -1;
84 }
85 }
86 return 0;
87 }
88
89 /* Backup the original file. */
90
91 int
backup_file(const char * orig)92 backup_file(const char *orig)
93 {
94 struct stat filestat;
95 char bakname[PATH_MAX], *s, *simplename;
96 dev_t orig_device;
97 ino_t orig_inode;
98
99 if (backup_type == none || stat(orig, &filestat) != 0)
100 return 0; /* nothing to do */
101 orig_device = filestat.st_dev;
102 orig_inode = filestat.st_ino;
103
104 if (origprae) {
105 if (strlcpy(bakname, origprae, sizeof(bakname)) >= sizeof(bakname) ||
106 strlcat(bakname, orig, sizeof(bakname)) >= sizeof(bakname))
107 fatal("filename %s too long for buffer\n", origprae);
108 } else {
109 if ((s = find_backup_file_name(orig)) == NULL)
110 fatal("out of memory\n");
111 if (strlcpy(bakname, s, sizeof(bakname)) >= sizeof(bakname))
112 fatal("filename %s too long for buffer\n", s);
113 free(s);
114 }
115
116 if ((simplename = strrchr(bakname, '/')) != NULL)
117 simplename = simplename + 1;
118 else
119 simplename = bakname;
120
121 /*
122 * Find a backup name that is not the same file. Change the
123 * first lowercase char into uppercase; if that isn't
124 * sufficient, chop off the first char and try again.
125 */
126 while (stat(bakname, &filestat) == 0 &&
127 orig_device == filestat.st_dev && orig_inode == filestat.st_ino) {
128 /* Skip initial non-lowercase chars. */
129 for (s = simplename; *s && !islower((unsigned char)*s); s++)
130 ;
131 if (*s)
132 *s = toupper((unsigned char)*s);
133 else
134 memmove(simplename, simplename + 1,
135 strlen(simplename + 1) + 1);
136 }
137 #ifdef DEBUGGING
138 if (debug & 4)
139 say("Moving %s to %s.\n", orig, bakname);
140 #endif
141 if (rename(orig, bakname) == -1) {
142 if (errno != EXDEV || copy_file(orig, bakname) < 0)
143 return -1;
144 }
145 return 0;
146 }
147
148 /*
149 * Copy a file.
150 */
151 int
copy_file(const char * from,const char * to)152 copy_file(const char *from, const char *to)
153 {
154 int tofd, fromfd;
155 ssize_t i;
156
157 tofd = open(to, O_CREAT|O_TRUNC|O_WRONLY, 0666);
158 if (tofd == -1)
159 return -1;
160 fromfd = open(from, O_RDONLY);
161 if (fromfd == -1)
162 pfatal("internal error, can't reopen %s", from);
163 while ((i = read(fromfd, buf, bufsz)) > 0)
164 if (write(tofd, buf, i) != i)
165 pfatal("write to %s failed", to);
166 close(fromfd);
167 close(tofd);
168 return 0;
169 }
170
171 /*
172 * Allocate a unique area for a string.
173 */
174 char *
savestr(const char * s)175 savestr(const char *s)
176 {
177 char *rv;
178
179 if (!s)
180 s = "Oops";
181 rv = strdup(s);
182 if (rv == NULL) {
183 if (using_plan_a)
184 out_of_mem = true;
185 else
186 fatal("out of memory\n");
187 }
188 return rv;
189 }
190
191 /*
192 * Allocate a unique area for a string. Call fatal if out of memory.
193 */
194 char *
xstrdup(const char * s)195 xstrdup(const char *s)
196 {
197 char *rv;
198
199 if (!s)
200 s = "Oops";
201 rv = strdup(s);
202 if (rv == NULL)
203 fatal("out of memory\n");
204 return rv;
205 }
206
207 /*
208 * Vanilla terminal output (buffered).
209 */
210 void
say(const char * fmt,...)211 say(const char *fmt, ...)
212 {
213 va_list ap;
214
215 va_start(ap, fmt);
216 vfprintf(stdout, fmt, ap);
217 va_end(ap);
218 fflush(stdout);
219 }
220
221 /*
222 * Terminal output, pun intended.
223 */
224 void
fatal(const char * fmt,...)225 fatal(const char *fmt, ...)
226 {
227 va_list ap;
228
229 va_start(ap, fmt);
230 fprintf(stderr, "patch: **** ");
231 vfprintf(stderr, fmt, ap);
232 va_end(ap);
233 my_exit(2);
234 }
235
236 /*
237 * Say something from patch, something from the system, then silence . . .
238 */
239 void
pfatal(const char * fmt,...)240 pfatal(const char *fmt, ...)
241 {
242 va_list ap;
243 int errnum = errno;
244
245 fprintf(stderr, "patch: **** ");
246 va_start(ap, fmt);
247 vfprintf(stderr, fmt, ap);
248 va_end(ap);
249 fprintf(stderr, ": %s\n", strerror(errnum));
250 my_exit(2);
251 }
252
253 /*
254 * Get a response from the user via /dev/tty
255 */
256 void
ask(const char * fmt,...)257 ask(const char *fmt, ...)
258 {
259 va_list ap;
260 ssize_t nr;
261 static int ttyfd = -1;
262
263 va_start(ap, fmt);
264 vfprintf(stdout, fmt, ap);
265 va_end(ap);
266 fflush(stdout);
267 if (ttyfd < 0)
268 ttyfd = open(_PATH_TTY, O_RDONLY);
269 if (ttyfd >= 0) {
270 if ((nr = read(ttyfd, buf, bufsz)) > 0 &&
271 buf[nr - 1] == '\n')
272 buf[nr - 1] = '\0';
273 }
274 if (ttyfd == -1 || nr <= 0) {
275 /* no tty or error reading, pretend user entered 'return' */
276 putchar('\n');
277 buf[0] = '\0';
278 }
279 }
280
281 /*
282 * How to handle certain events when not in a critical region.
283 */
284 void
set_signals(int reset)285 set_signals(int reset)
286 {
287 static sig_t hupval, intval;
288
289 if (!reset) {
290 hupval = signal(SIGHUP, SIG_IGN);
291 if (hupval != SIG_IGN)
292 hupval = my_sigexit;
293 intval = signal(SIGINT, SIG_IGN);
294 if (intval != SIG_IGN)
295 intval = my_sigexit;
296 }
297 signal(SIGHUP, hupval);
298 signal(SIGINT, intval);
299 }
300
301 /*
302 * How to handle certain events when in a critical region.
303 */
304 void
ignore_signals(void)305 ignore_signals(void)
306 {
307 signal(SIGHUP, SIG_IGN);
308 signal(SIGINT, SIG_IGN);
309 }
310
311 /*
312 * Make sure we'll have the directories to create a file. If `striplast' is
313 * true, ignore the last element of `filename'.
314 */
315
316 void
makedirs(const char * filename,bool striplast)317 makedirs(const char *filename, bool striplast)
318 {
319 char *tmpbuf;
320
321 if ((tmpbuf = strdup(filename)) == NULL)
322 fatal("out of memory\n");
323
324 if (striplast) {
325 char *s = strrchr(tmpbuf, '/');
326 if (s == NULL) {
327 free(tmpbuf);
328 return; /* nothing to be done */
329 }
330 *s = '\0';
331 }
332 if (mkpath(tmpbuf) != 0)
333 pfatal("creation of %s failed", tmpbuf);
334 free(tmpbuf);
335 }
336
337 /*
338 * Make filenames more reasonable.
339 */
340 char *
fetchname(const char * at,bool * exists,int strip_leading)341 fetchname(const char *at, bool *exists, int strip_leading)
342 {
343 char *fullname, *name, *t;
344 int sleading, tab;
345 struct stat filestat;
346
347 if (at == NULL || *at == '\0')
348 return NULL;
349 while (isspace((unsigned char)*at))
350 at++;
351 #ifdef DEBUGGING
352 if (debug & 128)
353 say("fetchname %s %d\n", at, strip_leading);
354 #endif
355 /* So files can be created by diffing against /dev/null. */
356 if (strnEQ(at, _PATH_DEVNULL, sizeof(_PATH_DEVNULL) - 1))
357 return NULL;
358 name = fullname = t = savestr(at);
359
360 tab = strchr(t, '\t') != NULL;
361 /* Strip off up to `strip_leading' path components and NUL terminate. */
362 for (sleading = strip_leading; *t != '\0' && ((tab && *t != '\t') ||
363 !isspace((unsigned char)*t)); t++) {
364 if (t[0] == '/' && t[1] != '/' && t[1] != '\0')
365 if (--sleading >= 0)
366 name = t + 1;
367 }
368 *t = '\0';
369
370 /*
371 * If no -p option was given (957 is the default value!), we were
372 * given a relative pathname, and the leading directories that we
373 * just stripped off all exist, put them back on.
374 */
375 if (strip_leading == 957 && name != fullname && *fullname != '/') {
376 name[-1] = '\0';
377 if (stat(fullname, &filestat) == 0 && S_ISDIR(filestat.st_mode)) {
378 name[-1] = '/';
379 name = fullname;
380 }
381 }
382 name = savestr(name);
383 free(fullname);
384
385 *exists = stat(name, &filestat) == 0;
386 return name;
387 }
388
389 void
version(void)390 version(void)
391 {
392 fprintf(stderr, "Patch version 2.0-12u8-OpenBSD\n");
393 my_exit(EXIT_SUCCESS);
394 }
395
396 void
my_cleanup(void)397 my_cleanup(void)
398 {
399 unlink(TMPINNAME);
400 if (!toutkeep)
401 unlink(TMPOUTNAME);
402 if (!trejkeep)
403 unlink(TMPREJNAME);
404 unlink(TMPPATNAME);
405 }
406
407 /*
408 * Exit with cleanup.
409 */
410 void
my_exit(int status)411 my_exit(int status)
412 {
413 my_cleanup();
414 exit(status);
415 }
416
417 /*
418 * Exit with cleanup, from a signal handler.
419 */
420 void
my_sigexit(int signo)421 my_sigexit(int signo)
422 {
423 my_cleanup();
424 _exit(2);
425 }
426