xref: /netbsd/usr.bin/patch/inp.c (revision 0f6dca37)
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 1.30 2023/06/16 23:36:26 wiz 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 1.30 2023/06/16 23:36:26 wiz 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
re_input(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
scan_input(const char * filename)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
reallocate_lines(size_t * lines_allocated)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
plan_a(const char * filename)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(lbuf);
275 		free(tmp_filename1);
276 		free(tmp_filename2);
277 	}
278 
279 	filemode = filestat.st_mode;
280 	if (!S_ISREG(filemode))
281 		fatal("%s is not a normal file--can't patch\n", filename);
282 	i_size = filestat.st_size;
283 	if (out_of_mem) {
284 		set_hunkmax();	/* make sure dynamic arrays are allocated */
285 		out_of_mem = false;
286 		return false;	/* force plan b because plan a bombed */
287 	}
288 	if ((uintmax_t)i_size > (uintmax_t)SIZE_MAX) {
289 		say("block too large to mmap\n");
290 		return false;
291 	}
292 	if ((ifd = open(filename, O_RDONLY)) < 0)
293 		pfatal("can't open file %s", filename);
294 
295 	if (i_size) {
296 		i_womp = mmap(NULL, i_size, PROT_READ, MAP_PRIVATE, ifd, 0);
297 		if (i_womp == MAP_FAILED) {
298 			perror("mmap failed");
299 			i_womp = NULL;
300 			close(ifd);
301 			return false;
302 		}
303 	} else {
304 		i_womp = NULL;
305 	}
306 
307 	close(ifd);
308 	if (i_size)
309 		madvise(i_womp, i_size, MADV_SEQUENTIAL);
310 
311 	/* estimate the number of lines */
312 	lines_allocated = i_size / 25;
313 	if (lines_allocated < 100)
314 		lines_allocated = 100;
315 
316 	if (!reallocate_lines(&lines_allocated))
317 		return false;
318 
319 	/* now scan the buffer and build pointer array */
320 	iline = 1;
321 	i_ptr[iline] = i_womp;
322 	/* test for NUL too, to maintain the behavior of the original code */
323 	for (s = i_womp, i = 0; i < i_size && *s != '\0'; s++, i++) {
324 		if (*s == '\n') {
325 			if (iline == lines_allocated) {
326 				if (!reallocate_lines(&lines_allocated))
327 					return false;
328 			}
329 			/* these are NOT NUL terminated */
330 			i_ptr[++iline] = s + 1;
331 		}
332 	}
333 	/* if the last line contains no EOL, append one */
334 	if (i_size > 0 && i_womp[i_size - 1] != '\n') {
335 		last_line_missing_eol = true;
336 		/* fix last line */
337 		sz = s - i_ptr[iline];
338 		p = malloc(sz + 1);
339 		if (p == NULL) {
340 			free(i_ptr);
341 			i_ptr = NULL;
342 			munmap(i_womp, i_size);
343 			i_womp = NULL;
344 			return false;
345 		}
346 
347 		memcpy(p, i_ptr[iline], sz);
348 		p[sz] = '\n';
349 		i_ptr[iline] = p;
350 		/* count the extra line and make it point to some valid mem */
351 		i_ptr[++iline] = empty_line;
352 	} else
353 		last_line_missing_eol = false;
354 
355 	input_lines = iline - 1;
356 
357 	/* now check for revision, if any */
358 
359 	if (revision != NULL) {
360 		if (!rev_in_string(i_womp)) {
361 			if (force) {
362 				if (verbose)
363 					say("Warning: this file doesn't appear "
364 					    "to be the %s version--patching anyway.\n",
365 					    revision);
366 			} else if (batch) {
367 				fatal("this file doesn't appear to be the "
368 				    "%s version--aborting.\n",
369 				    revision);
370 			} else {
371 				ask("This file doesn't appear to be the "
372 				    "%s version--patch anyway? [n] ",
373 				    revision);
374 				if (*buf != 'y')
375 					fatal("aborted\n");
376 			}
377 		} else if (verbose)
378 			say("Good.  This file appears to be the %s version.\n",
379 			    revision);
380 	}
381 	return true;		/* plan a will work */
382 }
383 
384 /* Keep (virtually) nothing in memory. */
385 
386 static void
plan_b(const char * filename)387 plan_b(const char *filename)
388 {
389 	FILE	*ifp;
390 	size_t	i = 0, j, maxlen = 1;
391 	char	*p;
392 	bool	found_revision = (revision == NULL);
393 
394 	using_plan_a = false;
395 	if ((ifp = fopen(filename, "r")) == NULL)
396 		pfatal("can't open file %s", filename);
397 	unlink(TMPINNAME);
398 	if ((tifd = open(TMPINNAME, O_EXCL | O_CREAT | O_WRONLY, 0666)) < 0)
399 		pfatal("can't open file %s", TMPINNAME);
400 	while (getline(&buf, &bufsz, ifp) != -1) {
401 		if (revision != NULL && !found_revision && rev_in_string(buf))
402 			found_revision = true;
403 		if ((i = strlen(buf)) > maxlen)
404 			maxlen = i;	/* find longest line */
405 	}
406 	last_line_missing_eol = i > 0 && buf[i - 1] != '\n';
407 	if (last_line_missing_eol && maxlen == i)
408 		maxlen++;
409 
410 	if (revision != NULL) {
411 		if (!found_revision) {
412 			if (force) {
413 				if (verbose)
414 					say("Warning: this file doesn't appear "
415 					    "to be the %s version--patching anyway.\n",
416 					    revision);
417 			} else if (batch) {
418 				fatal("this file doesn't appear to be the "
419 				    "%s version--aborting.\n",
420 				    revision);
421 			} else {
422 				ask("This file doesn't appear to be the %s "
423 				    "version--patch anyway? [n] ",
424 				    revision);
425 				if (*buf != 'y')
426 					fatal("aborted\n");
427 			}
428 		} else if (verbose)
429 			say("Good.  This file appears to be the %s version.\n",
430 			    revision);
431 	}
432 	fseek(ifp, 0L, SEEK_SET);	/* rewind file */
433 	lines_per_buf = BUFFERSIZE / maxlen;
434 	tireclen = maxlen;
435 	tibuf[0] = malloc(BUFFERSIZE + 1);
436 	if (tibuf[0] == NULL)
437 		fatal("out of memory\n");
438 	tibuf[1] = malloc(BUFFERSIZE + 1);
439 	if (tibuf[1] == NULL)
440 		fatal("out of memory\n");
441 	for (i = 1;; i++) {
442 		p = tibuf[0] + maxlen * (i % lines_per_buf);
443 		if (i % lines_per_buf == 0)	/* new block */
444 			if (write(tifd, tibuf[0], BUFFERSIZE) < BUFFERSIZE)
445 				pfatal("can't write temp file");
446 		if (fgets(p, maxlen + 1, ifp) == NULL) {
447 			input_lines = i - 1;
448 			if (i % lines_per_buf != 0)
449 				if (write(tifd, tibuf[0], BUFFERSIZE) < BUFFERSIZE)
450 					pfatal("can't write temp file");
451 			break;
452 		}
453 		j = strlen(p);
454 		/* These are '\n' terminated strings, so no need to add a NUL */
455 		if (j == 0 || p[j - 1] != '\n')
456 			p[j] = '\n';
457 	}
458 	fclose(ifp);
459 	close(tifd);
460 	if ((tifd = open(TMPINNAME, O_RDONLY)) < 0)
461 		pfatal("can't reopen file %s", TMPINNAME);
462 }
463 
464 /*
465  * Fetch a line from the input file, \n terminated, not necessarily \0.
466  */
467 char *
ifetch(LINENUM line,int whichbuf)468 ifetch(LINENUM line, int whichbuf)
469 {
470 	if (line < 1 || line > input_lines) {
471 		if (warn_on_invalid_line) {
472 			say("No such line %ld in input file, ignoring\n", line);
473 			warn_on_invalid_line = false;
474 		}
475 		return NULL;
476 	}
477 	if (using_plan_a)
478 		return i_ptr[line];
479 	else {
480 		LINENUM	offline = line % lines_per_buf;
481 		LINENUM	baseline = line - offline;
482 
483 		if (tiline[0] == baseline)
484 			whichbuf = 0;
485 		else if (tiline[1] == baseline)
486 			whichbuf = 1;
487 		else {
488 			tiline[whichbuf] = baseline;
489 
490 			if (lseek(tifd, (off_t) (baseline / lines_per_buf *
491 			    BUFFERSIZE), SEEK_SET) < 0)
492 				pfatal("cannot seek in the temporary input file");
493 
494 			if (read(tifd, tibuf[whichbuf], BUFFERSIZE) < 0)
495 				pfatal("error reading tmp file %s", TMPINNAME);
496 		}
497 		return tibuf[whichbuf] + (tireclen * offline);
498 	}
499 }
500 
501 /*
502  * True if the string argument contains the revision number we want.
503  */
504 static bool
rev_in_string(const char * string)505 rev_in_string(const char *string)
506 {
507 	const char	*s;
508 	size_t		patlen;
509 
510 	if (revision == NULL)
511 		return true;
512 	patlen = strlen(revision);
513 	if (strnEQ(string, revision, patlen) && isspace((unsigned char)string[patlen]))
514 		return true;
515 	for (s = string; *s; s++) {
516 		if (isspace((unsigned char)*s) && strnEQ(s + 1, revision, patlen) &&
517 		    isspace((unsigned char)s[patlen + 1])) {
518 			return true;
519 		}
520 	}
521 	return false;
522 }
523