xref: /netbsd-src/usr.bin/patch/inp.c (revision 53b02e147d4ed531c0d2a5ca9b3e8026ba3e99b5)
1 /*
2  * $OpenBSD: inp.c,v 1.34 2006/03/11 19:41:30 otto Exp $
3  * $DragonFly: src/usr.bin/patch/inp.c,v 1.6 2007/09/29 23:11:10 swildner Exp $
4  * $NetBSD: inp.c,v 1.28 2021/05/26 07:57:05 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: inp.c,v 1.28 2021/05/26 07:57:05 cjep Exp $");
35 
36 #include <sys/types.h>
37 #include <sys/file.h>
38 #include <sys/stat.h>
39 #include <sys/mman.h>
40 #include <sys/wait.h>
41 
42 #include <ctype.h>
43 #include <errno.h>
44 #include <fcntl.h>
45 #include <libgen.h>
46 #include <limits.h>
47 #include <stddef.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <unistd.h>
52 
53 #include "common.h"
54 #include "util.h"
55 #include "pch.h"
56 #include "inp.h"
57 
58 
59 /* Input-file-with-indexable-lines abstract type */
60 
61 static off_t	i_size;		/* size of the input file */
62 static char	*i_womp;	/* plan a buffer for entire file */
63 static char	**i_ptr;	/* pointers to lines in i_womp */
64 static char	empty_line[] = { '\0' };
65 
66 static int	tifd = -1;	/* plan b virtual string array */
67 static char	*tibuf[2];	/* plan b buffers */
68 static LINENUM	tiline[2] = {-1, -1};	/* 1st line in each buffer */
69 static LINENUM	lines_per_buf;	/* how many lines per buffer */
70 static int	tireclen;	/* length of records in tmp file */
71 
72 static bool	rev_in_string(const char *);
73 static bool	reallocate_lines(size_t *);
74 
75 /* returns false if insufficient memory */
76 static bool	plan_a(const char *);
77 
78 static void	plan_b(const char *);
79 
80 /* New patch--prepare to edit another file. */
81 
82 void
83 re_input(void)
84 {
85 	if (using_plan_a) {
86 		i_size = 0;
87 		free(i_ptr);
88 		i_ptr = NULL;
89 		if (i_womp != NULL) {
90 			munmap(i_womp, i_size);
91 			i_womp = NULL;
92 		}
93 	} else {
94 		using_plan_a = true;	/* maybe the next one is smaller */
95 		close(tifd);
96 		tifd = -1;
97 		free(tibuf[0]);
98 		free(tibuf[1]);
99 		tibuf[0] = tibuf[1] = NULL;
100 		tiline[0] = tiline[1] = -1;
101 		tireclen = 0;
102 	}
103 }
104 
105 /* Construct the line index, somehow or other. */
106 
107 void
108 scan_input(const char *filename)
109 {
110 	if (!plan_a(filename))
111 		plan_b(filename);
112 	if (verbose) {
113 		say("Patching file %s using Plan %s...\n", filename,
114 		    (using_plan_a ? "A" : "B"));
115 	}
116 }
117 
118 static bool
119 reallocate_lines(size_t *lines_allocated)
120 {
121 	char	**p;
122 	size_t	new_size;
123 
124 	new_size = *lines_allocated * 3 / 2;
125 	p = pch_realloc(i_ptr, new_size + 2,  sizeof(char *));
126 	if (p == NULL) {	/* shucks, it was a near thing */
127 		munmap(i_womp, i_size);
128 		i_womp = NULL;
129 		free(i_ptr);
130 		i_ptr = NULL;
131 		*lines_allocated = 0;
132 		return false;
133 	}
134 	*lines_allocated = new_size;
135 	i_ptr = p;
136 	return true;
137 }
138 
139 /* Try keeping everything in memory. */
140 
141 static bool
142 plan_a(const char *filename)
143 {
144 	int		ifd, statfailed, devnull, pstat;
145 	char		*p, *s, *lbuf;
146 	struct stat	filestat;
147 	off_t		i;
148 	ptrdiff_t	sz;
149 	size_t		iline, lines_allocated, lbufsz;
150 	pid_t		pid;
151 	char		*argp[4] = {NULL};
152 
153 #ifdef DEBUGGING
154 	if (debug & 8)
155 		return false;
156 #endif
157 
158 	if (filename == NULL || *filename == '\0')
159 		return false;
160 
161 	statfailed = stat(filename, &filestat);
162 	if (statfailed && ok_to_create_file) {
163 		if (verbose)
164 			say("(Creating file %s...)\n", filename);
165 
166 		/*
167 		 * in check_patch case, we still display `Creating file' even
168 		 * though we're not. The rule is that -C should be as similar
169 		 * to normal patch behavior as possible
170 		 */
171 		if (check_only)
172 			return true;
173 		makedirs(filename, true);
174 		close(creat(filename, 0666));
175 		statfailed = stat(filename, &filestat);
176 	}
177 	if (statfailed && check_only)
178 		fatal("%s not found, -C mode, can't probe further\n", filename);
179 	/* For nonexistent or read-only files, look for RCS versions.  */
180 	if (statfailed ||
181 	    /* No one can write to it.  */
182 	    (filestat.st_mode & 0222) == 0 ||
183 	    /* I can't write to it.  */
184 	    ((filestat.st_mode & 0022) == 0 && filestat.st_uid != getuid())) {
185 		char	*filebase, *filedir;
186 		struct stat	cstat;
187 		char *tmp_filename1, *tmp_filename2;
188 
189 		tmp_filename1 = strdup(filename);
190 		tmp_filename2 = strdup(filename);
191 		if (tmp_filename1 == NULL || tmp_filename2 == NULL)
192 			fatal("strdupping filename");
193 
194  		filebase = basename(tmp_filename1);
195  		filedir = dirname(tmp_filename2);
196 
197 		lbufsz = INITLINELEN;
198 		if ((lbuf = malloc(bufsz)) == NULL)
199 			pfatal("allocating line buffer");
200 		lbuf[0] = '\0';
201 
202 #define try(f, a1, a2, a3) \
203 	(snprintf(lbuf, lbufsz, f, a1, a2, a3), stat(lbuf, &cstat) == 0)
204 
205 		/*
206 		 * else we can't write to it but it's not under a version
207 		 * control system, so just proceed.
208 		 */
209 		if (try("%s/RCS/%s%s", filedir, filebase, RCSSUFFIX) ||
210 		    try("%s/RCS/%s%s", filedir, filebase, "") ||
211 		    try("%s/%s%s", filedir, filebase, RCSSUFFIX)) {
212 			if (!statfailed) {
213 				if ((filestat.st_mode & 0222) != 0)
214 					/* The owner can write to it.  */
215 					fatal("file %s seems to be locked "
216 					    "by somebody else under RCS\n",
217 					    filename);
218 				/*
219 				 * It might be checked out unlocked.  See if
220 				 * it's safe to check out the default version
221 				 * locked.
222 				 */
223 				if (verbose)
224 					say("Comparing file %s to default "
225 					    "RCS version...\n", filename);
226 
227 				switch (pid = fork()) {
228 				case -1:
229 					fatal("can't fork: %s\n",
230 					    strerror(errno));
231 				case 0:
232 					devnull = open("/dev/null", O_RDONLY);
233 					if (devnull == -1) {
234 						fatal("can't open /dev/null: %s",
235 						    strerror(errno));
236 					}
237 					(void)dup2(devnull, STDOUT_FILENO);
238 					argp[0] = __UNCONST(RCSDIFF);
239 					argp[1] = __UNCONST(filename);
240 					execv(RCSDIFF, argp);
241 					exit(127);
242 				}
243 				pid = waitpid(pid, &pstat, 0);
244 				if (pid == -1 || WEXITSTATUS(pstat) != 0) {
245 					fatal("can't check out file %s: "
246 					    "differs from default RCS version\n",
247 					    filename);
248 				}
249 			}
250 
251 			if (verbose)
252 				say("Checking out file %s from RCS...\n",
253 				    filename);
254 
255 			switch (pid = fork()) {
256 			case -1:
257 				fatal("can't fork: %s\n", strerror(errno));
258 			case 0:
259 				argp[0] = __UNCONST(CHECKOUT);
260 				argp[1] = __UNCONST("-l");
261 				argp[2] = __UNCONST(filename);
262 				execv(CHECKOUT, argp);
263 				exit(127);
264 			}
265 			pid = waitpid(pid, &pstat, 0);
266 			if (pid == -1 || WEXITSTATUS(pstat) != 0 ||
267 			    stat(filename, &filestat)) {
268 				fatal("can't check out file %s from RCS\n",
269 				    filename);
270 			}
271 		} else if (statfailed) {
272 			fatal("can't find %s\n", filename);
273 		}
274 		free(tmp_filename1);
275 		free(tmp_filename2);
276 	}
277 
278 	filemode = filestat.st_mode;
279 	if (!S_ISREG(filemode))
280 		fatal("%s is not a normal file--can't patch\n", filename);
281 	i_size = filestat.st_size;
282 	if (out_of_mem) {
283 		set_hunkmax();	/* make sure dynamic arrays are allocated */
284 		out_of_mem = false;
285 		return false;	/* force plan b because plan a bombed */
286 	}
287 	if ((uintmax_t)i_size > (uintmax_t)SIZE_MAX) {
288 		say("block too large to mmap\n");
289 		return false;
290 	}
291 	if ((ifd = open(filename, O_RDONLY)) < 0)
292 		pfatal("can't open file %s", filename);
293 
294 	if (i_size) {
295 		i_womp = mmap(NULL, i_size, PROT_READ, MAP_PRIVATE, ifd, 0);
296 		if (i_womp == MAP_FAILED) {
297 			perror("mmap failed");
298 			i_womp = NULL;
299 			close(ifd);
300 			return false;
301 		}
302 	} else {
303 		i_womp = NULL;
304 	}
305 
306 	close(ifd);
307 	if (i_size)
308 		madvise(i_womp, i_size, MADV_SEQUENTIAL);
309 
310 	/* estimate the number of lines */
311 	lines_allocated = i_size / 25;
312 	if (lines_allocated < 100)
313 		lines_allocated = 100;
314 
315 	if (!reallocate_lines(&lines_allocated))
316 		return false;
317 
318 	/* now scan the buffer and build pointer array */
319 	iline = 1;
320 	i_ptr[iline] = i_womp;
321 	/* test for NUL too, to maintain the behavior of the original code */
322 	for (s = i_womp, i = 0; i < i_size && *s != '\0'; s++, i++) {
323 		if (*s == '\n') {
324 			if (iline == lines_allocated) {
325 				if (!reallocate_lines(&lines_allocated))
326 					return false;
327 			}
328 			/* these are NOT NUL terminated */
329 			i_ptr[++iline] = s + 1;
330 		}
331 	}
332 	/* if the last line contains no EOL, append one */
333 	if (i_size > 0 && i_womp[i_size - 1] != '\n') {
334 		last_line_missing_eol = true;
335 		/* fix last line */
336 		sz = s - i_ptr[iline];
337 		p = malloc(sz + 1);
338 		if (p == NULL) {
339 			free(i_ptr);
340 			i_ptr = NULL;
341 			munmap(i_womp, i_size);
342 			i_womp = NULL;
343 			return false;
344 		}
345 
346 		memcpy(p, i_ptr[iline], sz);
347 		p[sz] = '\n';
348 		i_ptr[iline] = p;
349 		/* count the extra line and make it point to some valid mem */
350 		i_ptr[++iline] = empty_line;
351 	} else
352 		last_line_missing_eol = false;
353 
354 	input_lines = iline - 1;
355 
356 	/* now check for revision, if any */
357 
358 	if (revision != NULL) {
359 		if (!rev_in_string(i_womp)) {
360 			if (force) {
361 				if (verbose)
362 					say("Warning: this file doesn't appear "
363 					    "to be the %s version--patching anyway.\n",
364 					    revision);
365 			} else if (batch) {
366 				fatal("this file doesn't appear to be the "
367 				    "%s version--aborting.\n",
368 				    revision);
369 			} else {
370 				ask("This file doesn't appear to be the "
371 				    "%s version--patch anyway? [n] ",
372 				    revision);
373 				if (*buf != 'y')
374 					fatal("aborted\n");
375 			}
376 		} else if (verbose)
377 			say("Good.  This file appears to be the %s version.\n",
378 			    revision);
379 	}
380 	return true;		/* plan a will work */
381 }
382 
383 /* Keep (virtually) nothing in memory. */
384 
385 static void
386 plan_b(const char *filename)
387 {
388 	FILE	*ifp;
389 	size_t	i = 0, j, maxlen = 1;
390 	char	*p;
391 	bool	found_revision = (revision == NULL);
392 
393 	using_plan_a = false;
394 	if ((ifp = fopen(filename, "r")) == NULL)
395 		pfatal("can't open file %s", filename);
396 	unlink(TMPINNAME);
397 	if ((tifd = open(TMPINNAME, O_EXCL | O_CREAT | O_WRONLY, 0666)) < 0)
398 		pfatal("can't open file %s", TMPINNAME);
399 	while (getline(&buf, &bufsz, ifp) != -1) {
400 		if (revision != NULL && !found_revision && rev_in_string(buf))
401 			found_revision = true;
402 		if ((i = strlen(buf)) > maxlen)
403 			maxlen = i;	/* find longest line */
404 	}
405 	last_line_missing_eol = i > 0 && buf[i - 1] != '\n';
406 	if (last_line_missing_eol && maxlen == i)
407 		maxlen++;
408 
409 	if (revision != NULL) {
410 		if (!found_revision) {
411 			if (force) {
412 				if (verbose)
413 					say("Warning: this file doesn't appear "
414 					    "to be the %s version--patching anyway.\n",
415 					    revision);
416 			} else if (batch) {
417 				fatal("this file doesn't appear to be the "
418 				    "%s version--aborting.\n",
419 				    revision);
420 			} else {
421 				ask("This file doesn't appear to be the %s "
422 				    "version--patch anyway? [n] ",
423 				    revision);
424 				if (*buf != 'y')
425 					fatal("aborted\n");
426 			}
427 		} else if (verbose)
428 			say("Good.  This file appears to be the %s version.\n",
429 			    revision);
430 	}
431 	fseek(ifp, 0L, SEEK_SET);	/* rewind file */
432 	lines_per_buf = BUFFERSIZE / maxlen;
433 	tireclen = maxlen;
434 	tibuf[0] = malloc(BUFFERSIZE + 1);
435 	if (tibuf[0] == NULL)
436 		fatal("out of memory\n");
437 	tibuf[1] = malloc(BUFFERSIZE + 1);
438 	if (tibuf[1] == NULL)
439 		fatal("out of memory\n");
440 	for (i = 1;; i++) {
441 		p = tibuf[0] + maxlen * (i % lines_per_buf);
442 		if (i % lines_per_buf == 0)	/* new block */
443 			if (write(tifd, tibuf[0], BUFFERSIZE) < BUFFERSIZE)
444 				pfatal("can't write temp file");
445 		if (fgets(p, maxlen + 1, ifp) == NULL) {
446 			input_lines = i - 1;
447 			if (i % lines_per_buf != 0)
448 				if (write(tifd, tibuf[0], BUFFERSIZE) < BUFFERSIZE)
449 					pfatal("can't write temp file");
450 			break;
451 		}
452 		j = strlen(p);
453 		/* These are '\n' terminated strings, so no need to add a NUL */
454 		if (j == 0 || p[j - 1] != '\n')
455 			p[j] = '\n';
456 	}
457 	fclose(ifp);
458 	close(tifd);
459 	if ((tifd = open(TMPINNAME, O_RDONLY)) < 0)
460 		pfatal("can't reopen file %s", TMPINNAME);
461 }
462 
463 /*
464  * Fetch a line from the input file, \n terminated, not necessarily \0.
465  */
466 char *
467 ifetch(LINENUM line, int whichbuf)
468 {
469 	if (line < 1 || line > input_lines) {
470 		if (warn_on_invalid_line) {
471 			say("No such line %ld in input file, ignoring\n", line);
472 			warn_on_invalid_line = false;
473 		}
474 		return NULL;
475 	}
476 	if (using_plan_a)
477 		return i_ptr[line];
478 	else {
479 		LINENUM	offline = line % lines_per_buf;
480 		LINENUM	baseline = line - offline;
481 
482 		if (tiline[0] == baseline)
483 			whichbuf = 0;
484 		else if (tiline[1] == baseline)
485 			whichbuf = 1;
486 		else {
487 			tiline[whichbuf] = baseline;
488 
489 			if (lseek(tifd, (off_t) (baseline / lines_per_buf *
490 			    BUFFERSIZE), SEEK_SET) < 0)
491 				pfatal("cannot seek in the temporary input file");
492 
493 			if (read(tifd, tibuf[whichbuf], BUFFERSIZE) < 0)
494 				pfatal("error reading tmp file %s", TMPINNAME);
495 		}
496 		return tibuf[whichbuf] + (tireclen * offline);
497 	}
498 }
499 
500 /*
501  * True if the string argument contains the revision number we want.
502  */
503 static bool
504 rev_in_string(const char *string)
505 {
506 	const char	*s;
507 	size_t		patlen;
508 
509 	if (revision == NULL)
510 		return true;
511 	patlen = strlen(revision);
512 	if (strnEQ(string, revision, patlen) && isspace((unsigned char)string[patlen]))
513 		return true;
514 	for (s = string; *s; s++) {
515 		if (isspace((unsigned char)*s) && strnEQ(s + 1, revision, patlen) &&
516 		    isspace((unsigned char)s[patlen + 1])) {
517 			return true;
518 		}
519 	}
520 	return false;
521 }
522