xref: /openbsd-src/usr.bin/patch/inp.c (revision ae3cb403620ab940fbaabb3055fac045a63d56b7)
1 /*	$OpenBSD: inp.c,v 1.47 2017/03/25 23:13:45 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/types.h>
30 #include <sys/file.h>
31 #include <sys/stat.h>
32 #include <sys/mman.h>
33 
34 #include <ctype.h>
35 #include <libgen.h>
36 #include <stddef.h>
37 #include <stdint.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <unistd.h>
42 
43 #include "common.h"
44 #include "util.h"
45 #include "pch.h"
46 #include "inp.h"
47 
48 
49 /* Input-file-with-indexable-lines abstract type */
50 
51 static off_t	i_size;		/* size of the input file */
52 static char	*i_womp;	/* plan a buffer for entire file */
53 static char	**i_ptr;	/* pointers to lines in i_womp */
54 
55 static int	tifd = -1;	/* plan b virtual string array */
56 static char	*tibuf[2];	/* plan b buffers */
57 static LINENUM	tiline[2] = {-1, -1};	/* 1st line in each buffer */
58 static size_t	lines_per_buf;	/* how many lines per buffer */
59 static size_t	tibuflen;	/* plan b buffer length */
60 static size_t	tireclen;	/* length of records in tmp file */
61 
62 static bool	rev_in_string(const char *);
63 static bool	reallocate_lines(size_t *);
64 
65 /* returns false if insufficient memory */
66 static bool	plan_a(const char *);
67 
68 static void	plan_b(const char *);
69 
70 /* New patch--prepare to edit another file. */
71 
72 void
73 re_input(void)
74 {
75 	if (using_plan_a) {
76 		free(i_ptr);
77 		i_ptr = NULL;
78 		if (i_womp != NULL) {
79 			munmap(i_womp, i_size);
80 			i_womp = NULL;
81 		}
82 		i_size = 0;
83 	} else {
84 		using_plan_a = true;	/* maybe the next one is smaller */
85 		close(tifd);
86 		tifd = -1;
87 		free(tibuf[0]);
88 		free(tibuf[1]);
89 		tibuf[0] = tibuf[1] = NULL;
90 		tiline[0] = tiline[1] = -1;
91 		tireclen = 0;
92 	}
93 }
94 
95 /* Construct the line index, somehow or other. */
96 
97 void
98 scan_input(const char *filename)
99 {
100 	if (!plan_a(filename))
101 		plan_b(filename);
102 	if (verbose) {
103 		say("Patching file %s using Plan %s...\n", filename,
104 		    (using_plan_a ? "A" : "B"));
105 	}
106 }
107 
108 static bool
109 reallocate_lines(size_t *lines_allocatedp)
110 {
111 	char	**p;
112 	size_t	new_size;
113 
114 	new_size = *lines_allocatedp * 3 / 2;
115 	p = reallocarray(i_ptr, new_size + 2, sizeof(char *));
116 	if (p == NULL) {	/* shucks, it was a near thing */
117 		munmap(i_womp, i_size);
118 		i_womp = NULL;
119 		free(i_ptr);
120 		i_ptr = NULL;
121 		*lines_allocatedp = 0;
122 		return false;
123 	}
124 	*lines_allocatedp = new_size;
125 	i_ptr = p;
126 	return true;
127 }
128 
129 /* Try keeping everything in memory. */
130 
131 static bool
132 plan_a(const char *filename)
133 {
134 	int		ifd, statfailed;
135 	char		*p, *s;
136 	struct stat	filestat;
137 	off_t		i;
138 	ptrdiff_t	sz;
139 	size_t		iline, lines_allocated;
140 
141 #ifdef DEBUGGING
142 	if (debug & 8)
143 		return false;
144 #endif
145 
146 	if (filename == NULL || *filename == '\0')
147 		return false;
148 
149 	statfailed = stat(filename, &filestat);
150 	if (statfailed && ok_to_create_file) {
151 		int fd;
152 
153 		if (verbose)
154 			say("(Creating file %s...)\n", filename);
155 
156 		/*
157 		 * in check_patch case, we still display `Creating file' even
158 		 * though we're not. The rule is that -C should be as similar
159 		 * to normal patch behavior as possible
160 		 */
161 		if (check_only)
162 			return true;
163 		makedirs(filename, true);
164 		if ((fd = open(filename, O_CREAT | O_TRUNC | O_WRONLY, 0666)) != -1)
165 			close(fd);
166 
167 		statfailed = stat(filename, &filestat);
168 	}
169 	if (statfailed)
170 		fatal("can't find %s\n", filename);
171 	filemode = filestat.st_mode;
172 	if (!S_ISREG(filemode))
173 		fatal("%s is not a normal file--can't patch\n", filename);
174 	i_size = filestat.st_size;
175 	if (out_of_mem) {
176 		set_hunkmax();	/* make sure dynamic arrays are allocated */
177 		out_of_mem = false;
178 		return false;	/* force plan b because plan a bombed */
179 	}
180 	if (i_size > SIZE_MAX) {
181 		say("block too large to mmap\n");
182 		return false;
183 	}
184 	if ((ifd = open(filename, O_RDONLY)) < 0)
185 		pfatal("can't open file %s", filename);
186 
187 	if (i_size) {
188 		i_womp = mmap(NULL, i_size, PROT_READ, MAP_PRIVATE, ifd, 0);
189 		if (i_womp == MAP_FAILED) {
190 			perror("mmap failed");
191 			i_womp = NULL;
192 			close(ifd);
193 			return false;
194 		}
195 	} else {
196 		i_womp = NULL;
197 	}
198 
199 	close(ifd);
200 	if (i_size)
201 		madvise(i_womp, i_size, MADV_SEQUENTIAL);
202 
203 	/* estimate the number of lines */
204 	lines_allocated = i_size / 25;
205 	if (lines_allocated < 100)
206 		lines_allocated = 100;
207 
208 	if (!reallocate_lines(&lines_allocated))
209 		return false;
210 
211 	/* now scan the buffer and build pointer array */
212 	iline = 1;
213 	i_ptr[iline] = i_womp;
214 	/* test for NUL too, to maintain the behavior of the original code */
215 	for (s = i_womp, i = 0; i < i_size && *s != '\0'; s++, i++) {
216 		if (*s == '\n') {
217 			if (iline == lines_allocated) {
218 				if (!reallocate_lines(&lines_allocated))
219 					return false;
220 			}
221 			/* these are NOT NUL terminated */
222 			i_ptr[++iline] = s + 1;
223 		}
224 	}
225 	/* if the last line contains no EOL, append one */
226 	if (i_size > 0 && i_womp[i_size - 1] != '\n') {
227 		last_line_missing_eol = true;
228 		/* fix last line */
229 		sz = s - i_ptr[iline];
230 		p = malloc(sz + 1);
231 		if (p == NULL) {
232 			free(i_ptr);
233 			i_ptr = NULL;
234 			munmap(i_womp, i_size);
235 			i_womp = NULL;
236 			return false;
237 		}
238 
239 		memcpy(p, i_ptr[iline], sz);
240 		p[sz] = '\n';
241 		i_ptr[iline] = p;
242 		/* count the extra line and make it point to some valid mem */
243 		i_ptr[++iline] = "";
244 	} else
245 		last_line_missing_eol = false;
246 
247 	input_lines = iline - 1;
248 
249 	/* now check for revision, if any */
250 
251 	if (revision != NULL) {
252 		if (i_womp == NULL || !rev_in_string(i_womp)) {
253 			if (force) {
254 				if (verbose)
255 					say("Warning: this file doesn't appear "
256 					    "to be the %s version--patching anyway.\n",
257 					    revision);
258 			} else if (batch) {
259 				fatal("this file doesn't appear to be the "
260 				    "%s version--aborting.\n",
261 				    revision);
262 			} else {
263 				ask("This file doesn't appear to be the "
264 				    "%s version--patch anyway? [n] ",
265 				    revision);
266 				if (*buf != 'y')
267 					fatal("aborted\n");
268 			}
269 		} else if (verbose)
270 			say("Good.  This file appears to be the %s version.\n",
271 			    revision);
272 	}
273 	return true;		/* plan a will work */
274 }
275 
276 /* Keep (virtually) nothing in memory. */
277 
278 static void
279 plan_b(const char *filename)
280 {
281 	FILE	*ifp;
282 	size_t	i = 0, j, len, maxlen = 1;
283 	char	*lbuf = NULL, *p;
284 	bool	found_revision = (revision == NULL);
285 
286 	using_plan_a = false;
287 	if ((ifp = fopen(filename, "r")) == NULL)
288 		pfatal("can't open file %s", filename);
289 	(void) unlink(TMPINNAME);
290 	if ((tifd = open(TMPINNAME, O_EXCL | O_CREAT | O_WRONLY, 0666)) < 0)
291 		pfatal("can't open file %s", TMPINNAME);
292 	while ((p = fgetln(ifp, &len)) != NULL) {
293 		if (p[len - 1] == '\n')
294 			p[len - 1] = '\0';
295 		else {
296 			/* EOF without EOL, copy and add the NUL */
297 			if ((lbuf = malloc(len + 1)) == NULL)
298 				fatal("out of memory\n");
299 			memcpy(lbuf, p, len);
300 			lbuf[len] = '\0';
301 			p = lbuf;
302 
303 			last_line_missing_eol = true;
304 			len++;
305 		}
306 		if (revision != NULL && !found_revision && rev_in_string(p))
307 			found_revision = true;
308 		if (len > maxlen)
309 			maxlen = len;	/* find longest line */
310 	}
311 	free(lbuf);
312 	if (ferror(ifp))
313 		pfatal("can't read file %s", filename);
314 
315 	if (revision != NULL) {
316 		if (!found_revision) {
317 			if (force) {
318 				if (verbose)
319 					say("Warning: this file doesn't appear "
320 					    "to be the %s version--patching anyway.\n",
321 					    revision);
322 			} else if (batch) {
323 				fatal("this file doesn't appear to be the "
324 				    "%s version--aborting.\n",
325 				    revision);
326 			} else {
327 				ask("This file doesn't appear to be the %s "
328 				    "version--patch anyway? [n] ",
329 				    revision);
330 				if (*buf != 'y')
331 					fatal("aborted\n");
332 			}
333 		} else if (verbose)
334 			say("Good.  This file appears to be the %s version.\n",
335 			    revision);
336 	}
337 	fseek(ifp, 0L, SEEK_SET);	/* rewind file */
338 	tireclen = maxlen;
339 	tibuflen = maxlen > BUFFERSIZE ? maxlen : BUFFERSIZE;
340 	lines_per_buf = tibuflen / maxlen;
341 	tibuf[0] = malloc(tibuflen + 1);
342 	if (tibuf[0] == NULL)
343 		fatal("out of memory\n");
344 	tibuf[1] = malloc(tibuflen + 1);
345 	if (tibuf[1] == NULL)
346 		fatal("out of memory\n");
347 	for (i = 1;; i++) {
348 		p = tibuf[0] + maxlen * (i % lines_per_buf);
349 		if (i % lines_per_buf == 0)	/* new block */
350 			if (write(tifd, tibuf[0], tibuflen) !=
351 			    (ssize_t) tibuflen)
352 				pfatal("can't write temp file");
353 		if (fgets(p, maxlen + 1, ifp) == NULL) {
354 			input_lines = i - 1;
355 			if (i % lines_per_buf != 0)
356 				if (write(tifd, tibuf[0], tibuflen) !=
357 				    (ssize_t) tibuflen)
358 					pfatal("can't write temp file");
359 			break;
360 		}
361 		j = strlen(p);
362 		/* These are '\n' terminated strings, so no need to add a NUL */
363 		if (j == 0 || p[j - 1] != '\n')
364 			p[j] = '\n';
365 	}
366 	fclose(ifp);
367 	close(tifd);
368 	if ((tifd = open(TMPINNAME, O_RDONLY)) < 0)
369 		pfatal("can't reopen file %s", TMPINNAME);
370 }
371 
372 /*
373  * Fetch a line from the input file, \n terminated, not necessarily \0.
374  */
375 char *
376 ifetch(LINENUM line, int whichbuf)
377 {
378 	if (line < 1 || line > input_lines) {
379 		if (warn_on_invalid_line) {
380 			say("No such line %ld in input file, ignoring\n", line);
381 			warn_on_invalid_line = false;
382 		}
383 		return NULL;
384 	}
385 	if (using_plan_a)
386 		return i_ptr[line];
387 	else {
388 		LINENUM	offline = line % lines_per_buf;
389 		LINENUM	baseline = line - offline;
390 
391 		if (tiline[0] == baseline)
392 			whichbuf = 0;
393 		else if (tiline[1] == baseline)
394 			whichbuf = 1;
395 		else {
396 			tiline[whichbuf] = baseline;
397 
398 			if (lseek(tifd, (off_t) (baseline / lines_per_buf *
399 			    tibuflen), SEEK_SET) < 0)
400 				pfatal("cannot seek in the temporary input file");
401 
402 			if (read(tifd, tibuf[whichbuf], tibuflen)
403 			    != (ssize_t) tibuflen)
404 				pfatal("error reading tmp file %s", TMPINNAME);
405 		}
406 		return tibuf[whichbuf] + (tireclen * offline);
407 	}
408 }
409 
410 /*
411  * True if the string argument contains the revision number we want.
412  */
413 static bool
414 rev_in_string(const char *string)
415 {
416 	const char	*s;
417 	size_t		patlen;
418 
419 	if (revision == NULL)
420 		return true;
421 	patlen = strlen(revision);
422 	if (strnEQ(string, revision, patlen) &&
423 	    isspace((unsigned char)string[patlen]))
424 		return true;
425 	for (s = string; *s; s++) {
426 		if (isspace((unsigned char)*s) && strnEQ(s + 1, revision, patlen) &&
427 		    isspace((unsigned char)s[patlen + 1])) {
428 			return true;
429 		}
430 	}
431 	return false;
432 }
433