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      1 /*
      2  * $OpenBSD: util.c,v 1.32 2006/03/11 19:41:30 otto Exp $
      3  * $DragonFly: src/usr.bin/patch/util.c,v 1.9 2007/09/29 23:11:10 swildner Exp $
      4  * $NetBSD: util.c,v 1.30 2021/05/25 11:25:59 cjep Exp $
      5  */
      6 
      7 /*
      8  * patch - a program to apply diffs to original files
      9  *
     10  * Copyright 1986, Larry Wall
     11  *
     12  * Redistribution and use in source and binary forms, with or without
     13  * modification, are permitted provided that the following condition is met:
     14  * 1. Redistributions of source code must retain the above copyright notice,
     15  * this condition and the following disclaimer.
     16  *
     17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
     18  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     20  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
     21  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
     23  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
     24  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     27  * SUCH DAMAGE.
     28  *
     29  * -C option added in 1998, original code by Marc Espie, based on FreeBSD
     30  * behaviour
     31  */
     32 
     33 #include <sys/cdefs.h>
     34 __RCSID("$NetBSD: util.c,v 1.30 2021/05/25 11:25:59 cjep Exp $");
     35 
     36 #include <sys/param.h>
     37 #include <sys/stat.h>
     38 
     39 #include <ctype.h>
     40 #include <errno.h>
     41 #include <fcntl.h>
     42 #include <libgen.h>
     43 #include <signal.h>
     44 #include <stdarg.h>
     45 #include <stdlib.h>
     46 #include <stdio.h>
     47 #include <string.h>
     48 #include <unistd.h>
     49 
     50 #include "common.h"
     51 #include "util.h"
     52 #include "backupfile.h"
     53 #include "pathnames.h"
     54 
     55 /* Rename a file, copying it if necessary. */
     56 
     57 int
     58 move_file(const char *from, const char *to)
     59 {
     60 	int	fromfd;
     61 	ssize_t	i;
     62 
     63 	/* to stdout? */
     64 
     65 	if (strEQ(to, "-")) {
     66 #ifdef DEBUGGING
     67 		if (debug & 4)
     68 			say("Moving %s to stdout.\n", from);
     69 #endif
     70 		fromfd = open(from, O_RDONLY);
     71 		if (fromfd < 0)
     72 			pfatal("internal error, can't reopen %s", from);
     73 		while ((i = read(fromfd, buf, bufsz)) > 0)
     74 			if (write(STDOUT_FILENO, buf, i) != i)
     75 				pfatal("write failed");
     76 		close(fromfd);
     77 		return 0;
     78 	}
     79 	if (backup_file(to) < 0) {
     80 		say("Can't backup %s, output is in %s: %s\n", to, from,
     81 		    strerror(errno));
     82 		return -1;
     83 	}
     84 #ifdef DEBUGGING
     85 	if (debug & 4)
     86 		say("Moving %s to %s.\n", from, to);
     87 #endif
     88 	if (rename(from, to) < 0) {
     89 		if (errno != EXDEV || copy_file(from, to) < 0) {
     90 			say("Can't create %s, output is in %s: %s\n",
     91 			    to, from, strerror(errno));
     92 			return -1;
     93 		}
     94 	}
     95 	return 0;
     96 }
     97 
     98 /* Backup the original file.  */
     99 
    100 int
    101 backup_file(const char *orig)
    102 {
    103 	struct stat	filestat;
    104 	char		bakname[MAXPATHLEN], *s, *simplename;
    105 	dev_t		orig_device;
    106 	ino_t		orig_inode;
    107 
    108 	if (backup_type == none || stat(orig, &filestat) != 0)
    109 		return 0;			/* nothing to do */
    110 	/*
    111 	 * If the user used zero prefixes or suffixes, then
    112 	 * he doesn't want backups.  Yet we have to remove
    113 	 * orig to break possible hardlinks.
    114 	 */
    115 	if ((origprae && *origprae == 0) || *simple_backup_suffix == 0) {
    116 		unlink(orig);
    117 		return 0;
    118 	}
    119 	orig_device = filestat.st_dev;
    120 	orig_inode = filestat.st_ino;
    121 
    122 	if (origprae) {
    123 		if (strlcpy(bakname, origprae, sizeof(bakname)) >= sizeof(bakname) ||
    124 		    strlcat(bakname, orig, sizeof(bakname)) >= sizeof(bakname))
    125 			fatal("filename %s too long for buffer\n", origprae);
    126 	} else {
    127 		if ((s = find_backup_file_name(orig)) == NULL)
    128 			fatal("out of memory\n");
    129 		if (strlcpy(bakname, s, sizeof(bakname)) >= sizeof(bakname))
    130 			fatal("filename %s too long for buffer\n", s);
    131 		free(s);
    132 	}
    133 
    134 	if ((simplename = strrchr(bakname, '/')) != NULL)
    135 		simplename = simplename + 1;
    136 	else
    137 		simplename = bakname;
    138 
    139 	/*
    140 	 * Find a backup name that is not the same file. Change the
    141 	 * first lowercase char into uppercase; if that isn't
    142 	 * sufficient, chop off the first char and try again.
    143 	 */
    144 	while (stat(bakname, &filestat) == 0 &&
    145 	    orig_device == filestat.st_dev && orig_inode == filestat.st_ino) {
    146 		/* Skip initial non-lowercase chars.  */
    147 		for (s = simplename; *s && !islower((unsigned char)*s); s++)
    148 			;
    149 		if (*s)
    150 			*s = toupper((unsigned char)*s);
    151 		else
    152 			memmove(simplename, simplename + 1,
    153 			    strlen(simplename + 1) + 1);
    154 	}
    155 #ifdef DEBUGGING
    156 	if (debug & 4)
    157 		say("Moving %s to %s.\n", orig, bakname);
    158 #endif
    159 	if (rename(orig, bakname) < 0) {
    160 		if (errno != EXDEV || copy_file(orig, bakname) < 0)
    161 			return -1;
    162 	}
    163 	return 0;
    164 }
    165 
    166 /*
    167  * Copy a file.
    168  */
    169 int
    170 copy_file(const char *from, const char *to)
    171 {
    172 	int	tofd, fromfd;
    173 	ssize_t	i;
    174 
    175 	tofd = open(to, O_CREAT|O_TRUNC|O_WRONLY, 0666);
    176 	if (tofd < 0)
    177 		return -1;
    178 	fromfd = open(from, O_RDONLY, 0);
    179 	if (fromfd < 0)
    180 		pfatal("internal error, can't reopen %s", from);
    181 	while ((i = read(fromfd, buf, bufsz)) > 0)
    182 		if (write(tofd, buf, i) != i)
    183 			pfatal("write to %s failed", to);
    184 	close(fromfd);
    185 	close(tofd);
    186 	return 0;
    187 }
    188 
    189 /*
    190  * Allocate a unique area for a string.
    191  */
    192 char *
    193 savestr(const char *s)
    194 {
    195 	char	*rv;
    196 
    197 	if (!s)
    198 		s = "Oops";
    199 	rv = strdup(s);
    200 	if (rv == NULL) {
    201 		if (using_plan_a)
    202 			out_of_mem = true;
    203 		else
    204 			fatal("out of memory\n");
    205 	}
    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(stderr, fmt, ap);
    219 	va_end(ap);
    220 	fflush(stderr);
    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 = 0;
    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, bufsz)) > 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 = my_exit;
    295 		intval = signal(SIGINT, SIG_IGN);
    296 		if (intval != SIG_IGN)
    297 			intval = 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/SCCS directories
    393  * for a checked in version.
    394  */
    395 char *
    396 checked_in(char *file)
    397 {
    398 	char		*filebase, *filedir, tmpbuf[MAXPATHLEN];
    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 	    try("%s/SCCS/%s%s", filedir, SCCSPREFIX, filebase) ||
    411 	    try("%s/%s%s", filedir, SCCSPREFIX, filebase))
    412 		return file;
    413 
    414 	return NULL;
    415 }
    416 
    417 void
    418 version(void)
    419 {
    420 	printf("Patch version 2.0-12u9-NetBSD\n");
    421 	my_exit(EXIT_SUCCESS);
    422 }
    423 
    424 /*
    425  * Exit with cleanup.
    426  */
    427 void
    428 my_exit(int status)
    429 {
    430 	unlink(TMPINNAME);
    431 	if (!toutkeep)
    432 		unlink(TMPOUTNAME);
    433 	if (!trejkeep)
    434 		unlink(TMPREJNAME);
    435 	unlink(TMPPATNAME);
    436 	exit(status);
    437 }
    438 
    439 void *
    440 pch_realloc(void *ptr, size_t number, size_t size)
    441 {
    442 	if (number > SIZE_MAX / size) {
    443 		errno = EOVERFLOW;
    444 		return NULL;
    445 	}
    446 	return realloc(ptr, number * size);
    447 }
    448