xref: /dragonfly/usr.bin/patch/inp.c (revision 1bf4b486)
1 /*
2  * $OpenBSD: inp.c,v 1.32 2004/08/05 21:47:24 deraadt Exp $
3  * $DragonFly: src/usr.bin/patch/inp.c,v 1.3 2004/12/26 15:55:23 swildner Exp $
4  */
5 
6 /*
7  * patch - a program to apply diffs to original files
8  *
9  * Copyright 1986, Larry Wall
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following condition is met:
13  * 1. Redistributions of source code must retain the above copyright notice,
14  * this condition and the following disclaimer.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
17  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
20  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
23  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  * -C option added in 1998, original code by Marc Espie, based on FreeBSD
29  * behaviour
30  */
31 
32 #include <sys/types.h>
33 #include <sys/file.h>
34 #include <sys/stat.h>
35 #include <sys/mman.h>
36 
37 #include <ctype.h>
38 #include <libgen.h>
39 #include <limits.h>
40 #include <stddef.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <unistd.h>
45 
46 #include "common.h"
47 #include "util.h"
48 #include "pch.h"
49 #include "inp.h"
50 
51 
52 /* Input-file-with-indexable-lines abstract type */
53 
54 static off_t	i_size;		/* size of the input file */
55 static char	*i_womp;	/* plan a buffer for entire file */
56 static char	**i_ptr;	/* pointers to lines in i_womp */
57 static char	empty_line[] = { '\0' };
58 
59 static int	tifd = -1;	/* plan b virtual string array */
60 static char	*tibuf[2];	/* plan b buffers */
61 static LINENUM	tiline[2] = {-1, -1};	/* 1st line in each buffer */
62 static LINENUM	lines_per_buf;	/* how many lines per buffer */
63 static int	tireclen;	/* length of records in tmp file */
64 
65 static bool	rev_in_string(const char *);
66 static bool	reallocate_lines(size_t *);
67 
68 /* returns false if insufficient memory */
69 static bool	plan_a(const char *);
70 
71 static void	plan_b(const char *);
72 
73 /* New patch--prepare to edit another file. */
74 
75 void
76 re_input(void)
77 {
78 	if (using_plan_a) {
79 		i_size = 0;
80 		free(i_ptr);
81 		i_ptr = NULL;
82 		if (i_womp != NULL) {
83 			munmap(i_womp, i_size);
84 			i_womp = NULL;
85 		}
86 	} else {
87 		using_plan_a = true;	/* maybe the next one is smaller */
88 		close(tifd);
89 		tifd = -1;
90 		free(tibuf[0]);
91 		free(tibuf[1]);
92 		tibuf[0] = tibuf[1] = NULL;
93 		tiline[0] = tiline[1] = -1;
94 		tireclen = 0;
95 	}
96 }
97 
98 /* Constuct the line index, somehow or other. */
99 
100 void
101 scan_input(const char *filename)
102 {
103 	if (!plan_a(filename))
104 		plan_b(filename);
105 	if (verbose) {
106 		say("Patching file %s using Plan %s...\n", filename,
107 		    (using_plan_a ? "A" : "B"));
108 	}
109 }
110 
111 static bool
112 reallocate_lines(size_t *lines_allocated)
113 {
114 	char	**p;
115 	size_t	new_size;
116 
117 	new_size = *lines_allocated * 3 / 2;
118 	p = realloc(i_ptr, (new_size + 2) * sizeof(char *));
119 	if (p == NULL) {	/* shucks, it was a near thing */
120 		munmap(i_womp, i_size);
121 		i_womp = NULL;
122 		free(i_ptr);
123 		i_ptr = NULL;
124 		*lines_allocated = 0;
125 		return false;
126 	}
127 	*lines_allocated = new_size;
128 	i_ptr = p;
129 	return true;
130 }
131 
132 /* Try keeping everything in memory. */
133 
134 static bool
135 plan_a(const char *filename)
136 {
137 	int		ifd, statfailed;
138 	char		*p, *s, lbuf[MAXLINELEN];
139 	LINENUM		iline;
140 	struct stat	filestat;
141 	off_t		i;
142 	ptrdiff_t	sz;
143 	size_t		lines_allocated;
144 
145 #ifdef DEBUGGING
146 	if (debug & 8)
147 		return false;
148 #endif
149 
150 	if (filename == NULL || *filename == '\0')
151 		return false;
152 
153 	statfailed = stat(filename, &filestat);
154 	if (statfailed && ok_to_create_file) {
155 		if (verbose)
156 			say("(Creating file %s...)\n", filename);
157 
158 		/*
159 		 * in check_patch case, we still display `Creating file' even
160 		 * though we're not. The rule is that -C should be as similar
161 		 * to normal patch behavior as possible
162 		 */
163 		if (check_only)
164 			return true;
165 		makedirs(filename, true);
166 		close(creat(filename, 0666));
167 		statfailed = stat(filename, &filestat);
168 	}
169 	if (statfailed && check_only)
170 		fatal("%s not found, -C mode, can't probe further\n", filename);
171 	/* For nonexistent or read-only files, look for RCS or SCCS versions.  */
172 	if (statfailed ||
173 	    /* No one can write to it.  */
174 	    (filestat.st_mode & 0222) == 0 ||
175 	    /* I can't write to it.  */
176 	    ((filestat.st_mode & 0022) == 0 && filestat.st_uid != getuid())) {
177 		const char	*cs = NULL, *filebase, *filedir;
178 		struct stat	cstat;
179 
180 		filebase = basename(filename);
181 		filedir = dirname(filename);
182 
183 		/* Leave room in lbuf for the diff command.  */
184 		s = lbuf + 20;
185 
186 #define try(f, a1, a2, a3) \
187 	(snprintf(s, sizeof lbuf - 20, f, a1, a2, a3), stat(s, &cstat) == 0)
188 
189 		if (try("%s/RCS/%s%s", filedir, filebase, RCSSUFFIX) ||
190 		    try("%s/RCS/%s%s", filedir, filebase, "") ||
191 		    try("%s/%s%s", filedir, filebase, RCSSUFFIX)) {
192 			snprintf(buf, sizeof buf, CHECKOUT, filename);
193 			snprintf(lbuf, sizeof lbuf, RCSDIFF, filename);
194 			cs = "RCS";
195 		} else if (try("%s/SCCS/%s%s", filedir, SCCSPREFIX, filebase) ||
196 		    try("%s/%s%s", filedir, SCCSPREFIX, filebase)) {
197 			snprintf(buf, sizeof buf, GET, s);
198 			snprintf(lbuf, sizeof lbuf, SCCSDIFF, s, filename);
199 			cs = "SCCS";
200 		} else if (statfailed)
201 			fatal("can't find %s\n", filename);
202 		/*
203 		 * else we can't write to it but it's not under a version
204 		 * control system, so just proceed.
205 		 */
206 		if (cs) {
207 			if (!statfailed) {
208 				if ((filestat.st_mode & 0222) != 0)
209 					/* The owner can write to it.  */
210 					fatal("file %s seems to be locked "
211 					    "by somebody else under %s\n",
212 					    filename, cs);
213 				/*
214 				 * It might be checked out unlocked.  See if
215 				 * it's safe to check out the default version
216 				 * locked.
217 				 */
218 				if (verbose)
219 					say("Comparing file %s to default "
220 					    "%s version...\n",
221 					    filename, cs);
222 				if (system(lbuf))
223 					fatal("can't check out file %s: "
224 					    "differs from default %s version\n",
225 					    filename, cs);
226 			}
227 			if (verbose)
228 				say("Checking out file %s from %s...\n",
229 				    filename, cs);
230 			if (system(buf) || stat(filename, &filestat))
231 				fatal("can't check out file %s from %s\n",
232 				    filename, cs);
233 		}
234 	}
235 	filemode = filestat.st_mode;
236 	if (!S_ISREG(filemode))
237 		fatal("%s is not a normal file--can't patch\n", filename);
238 	i_size = filestat.st_size;
239 	if (out_of_mem) {
240 		set_hunkmax();	/* make sure dynamic arrays are allocated */
241 		out_of_mem = false;
242 		return false;	/* force plan b because plan a bombed */
243 	}
244 	if (i_size > SIZE_MAX) {
245 		say("block too large to mmap\n");
246 		return false;
247 	}
248 	if ((ifd = open(filename, O_RDONLY)) < 0)
249 		pfatal("can't open file %s", filename);
250 
251 	i_womp = mmap(NULL, i_size, PROT_READ, MAP_PRIVATE, ifd, 0);
252 	if (i_womp == MAP_FAILED) {
253 		perror("mmap failed");
254 		i_womp = NULL;
255 		close(ifd);
256 		return false;
257 	}
258 
259 	close(ifd);
260 	if (i_size)
261 		madvise(i_womp, i_size, MADV_SEQUENTIAL);
262 
263 	/* estimate the number of lines */
264 	lines_allocated = i_size / 25;
265 	if (lines_allocated < 100)
266 		lines_allocated = 100;
267 
268 	if (!reallocate_lines(&lines_allocated))
269 		return false;
270 
271 	/* now scan the buffer and build pointer array */
272 	iline = 1;
273 	i_ptr[iline] = i_womp;
274 	/* test for NUL too, to maintain the behavior of the original code */
275 	for (s = i_womp, i = 0; i < i_size && *s != '\0'; s++, i++) {
276 		if (*s == '\n') {
277 			if (iline == (LINENUM)lines_allocated) {
278 				if (!reallocate_lines(&lines_allocated))
279 					return false;
280 			}
281 			/* these are NOT NUL terminated */
282 			i_ptr[++iline] = s + 1;
283 		}
284 	}
285 	/* if the last line contains no EOL, append one */
286 	if (i_size > 0 && i_womp[i_size - 1] != '\n') {
287 		last_line_missing_eol = true;
288 		/* fix last line */
289 		sz = s - i_ptr[iline];
290 		p = malloc(sz + 1);
291 		if (p == NULL) {
292 			free(i_ptr);
293 			i_ptr = NULL;
294 			munmap(i_womp, i_size);
295 			i_womp = NULL;
296 			return false;
297 		}
298 
299 		memcpy(p, i_ptr[iline], sz);
300 		p[sz] = '\n';
301 		i_ptr[iline] = p;
302 		/* count the extra line and make it point to some valid mem */
303 		i_ptr[++iline] = empty_line;
304 	} else
305 		last_line_missing_eol = false;
306 
307 	input_lines = iline - 1;
308 
309 	/* now check for revision, if any */
310 
311 	if (revision != NULL) {
312 		if (!rev_in_string(i_womp)) {
313 			if (force) {
314 				if (verbose)
315 					say("Warning: this file doesn't appear "
316 					    "to be the %s version--patching anyway.\n",
317 					    revision);
318 			} else if (batch) {
319 				fatal("this file doesn't appear to be the "
320 				    "%s version--aborting.\n",
321 				    revision);
322 			} else {
323 				ask("This file doesn't appear to be the "
324 				    "%s version--patch anyway? [n] ",
325 				    revision);
326 				if (*buf != 'y')
327 					fatal("aborted\n");
328 			}
329 		} else if (verbose)
330 			say("Good.  This file appears to be the %s version.\n",
331 			    revision);
332 	}
333 	return true;		/* plan a will work */
334 }
335 
336 /* Keep (virtually) nothing in memory. */
337 
338 static void
339 plan_b(const char *filename)
340 {
341 	FILE	*ifp;
342 	int	i = 0, j, maxlen = 1;
343 	char	*p;
344 	bool	found_revision = (revision == NULL);
345 
346 	using_plan_a = false;
347 	if ((ifp = fopen(filename, "r")) == NULL)
348 		pfatal("can't open file %s", filename);
349 	unlink(TMPINNAME);
350 	if ((tifd = open(TMPINNAME, O_EXCL | O_CREAT | O_WRONLY, 0666)) < 0)
351 		pfatal("can't open file %s", TMPINNAME);
352 	while (fgets(buf, sizeof buf, ifp) != NULL) {
353 		if (revision != NULL && !found_revision && rev_in_string(buf))
354 			found_revision = true;
355 		if ((i = strlen(buf)) > maxlen)
356 			maxlen = i;	/* find longest line */
357 	}
358 	last_line_missing_eol = i > 0 && buf[i - 1] != '\n';
359 	if (last_line_missing_eol && maxlen == i)
360 		maxlen++;
361 
362 	if (revision != NULL) {
363 		if (!found_revision) {
364 			if (force) {
365 				if (verbose)
366 					say("Warning: this file doesn't appear "
367 					    "to be the %s version--patching anyway.\n",
368 					    revision);
369 			} else if (batch) {
370 				fatal("this file doesn't appear to be the "
371 				    "%s version--aborting.\n",
372 				    revision);
373 			} else {
374 				ask("This file doesn't appear to be the %s "
375 				    "version--patch anyway? [n] ",
376 				    revision);
377 				if (*buf != 'y')
378 					fatal("aborted\n");
379 			}
380 		} else if (verbose)
381 			say("Good.  This file appears to be the %s version.\n",
382 			    revision);
383 	}
384 	fseek(ifp, 0L, SEEK_SET);	/* rewind file */
385 	lines_per_buf = BUFFERSIZE / maxlen;
386 	tireclen = maxlen;
387 	tibuf[0] = malloc(BUFFERSIZE + 1);
388 	if (tibuf[0] == NULL)
389 		fatal("out of memory\n");
390 	tibuf[1] = malloc(BUFFERSIZE + 1);
391 	if (tibuf[1] == NULL)
392 		fatal("out of memory\n");
393 	for (i = 1;; i++) {
394 		p = tibuf[0] + maxlen * (i % lines_per_buf);
395 		if (i % lines_per_buf == 0)	/* new block */
396 			if (write(tifd, tibuf[0], BUFFERSIZE) < BUFFERSIZE)
397 				pfatal("can't write temp file");
398 		if (fgets(p, maxlen + 1, ifp) == NULL) {
399 			input_lines = i - 1;
400 			if (i % lines_per_buf != 0)
401 				if (write(tifd, tibuf[0], BUFFERSIZE) < BUFFERSIZE)
402 					pfatal("can't write temp file");
403 			break;
404 		}
405 		j = strlen(p);
406 		/* These are '\n' terminated strings, so no need to add a NUL */
407 		if (j == 0 || p[j - 1] != '\n')
408 			p[j] = '\n';
409 	}
410 	fclose(ifp);
411 	close(tifd);
412 	if ((tifd = open(TMPINNAME, O_RDONLY)) < 0)
413 		pfatal("can't reopen file %s", TMPINNAME);
414 }
415 
416 /*
417  * Fetch a line from the input file, \n terminated, not necessarily \0.
418  */
419 char *
420 ifetch(LINENUM line, int whichbuf)
421 {
422 	if (line < 1 || line > input_lines) {
423 		if (warn_on_invalid_line) {
424 			say("No such line %ld in input file, ignoring\n", line);
425 			warn_on_invalid_line = false;
426 		}
427 		return NULL;
428 	}
429 	if (using_plan_a)
430 		return i_ptr[line];
431 	else {
432 		LINENUM	offline = line % lines_per_buf;
433 		LINENUM	baseline = line - offline;
434 
435 		if (tiline[0] == baseline)
436 			whichbuf = 0;
437 		else if (tiline[1] == baseline)
438 			whichbuf = 1;
439 		else {
440 			tiline[whichbuf] = baseline;
441 
442 			lseek(tifd, (off_t) (baseline / lines_per_buf *
443 			    BUFFERSIZE), SEEK_SET);
444 
445 			if (read(tifd, tibuf[whichbuf], BUFFERSIZE) < 0)
446 				pfatal("error reading tmp file %s", TMPINNAME);
447 		}
448 		return tibuf[whichbuf] + (tireclen * offline);
449 	}
450 }
451 
452 /*
453  * True if the string argument contains the revision number we want.
454  */
455 static bool
456 rev_in_string(const char *string)
457 {
458 	const char	*s;
459 	int		patlen;
460 
461 	if (revision == NULL)
462 		return true;
463 	patlen = strlen(revision);
464 	if (strnEQ(string, revision, patlen) && isspace(string[patlen]))
465 		return true;
466 	for (s = string; *s; s++) {
467 		if (isspace(*s) && strnEQ(s + 1, revision, patlen) &&
468 		    isspace(s[patlen + 1])) {
469 			return true;
470 		}
471 	}
472 	return false;
473 }
474