xref: /freebsd/usr.bin/patch/inp.c (revision 25696725b65b651814799574fdfadb1b1a5e0b02)
1 /*-
2  * Copyright 1986, Larry Wall
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following condition is met:
6  * 1. Redistributions of source code must retain the above copyright notice,
7  * this condition and the following disclaimer.
8  *
9  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
10  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
11  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
12  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
13  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
14  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
15  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
16  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
17  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
18  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
19  * SUCH DAMAGE.
20  *
21  * patch - a program to apply diffs to original files
22  *
23  * -C option added in 1998, original code by Marc Espie, based on FreeBSD
24  * behaviour
25  *
26  * $OpenBSD: inp.c,v 1.44 2015/07/26 14:32:19 millert Exp $
27  */
28 
29 #include <sys/types.h>
30 #include <sys/file.h>
31 #include <sys/stat.h>
32 #include <sys/mman.h>
33 #include <sys/wait.h>
34 
35 #include <ctype.h>
36 #include <errno.h>
37 #include <libgen.h>
38 #include <paths.h>
39 #include <spawn.h>
40 #include <stddef.h>
41 #include <stdint.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <unistd.h>
46 
47 #include "common.h"
48 #include "util.h"
49 #include "pch.h"
50 #include "inp.h"
51 
52 
53 /* Input-file-with-indexable-lines abstract type */
54 
55 static size_t	i_size;		/* size of the input file */
56 static char	*i_womp;	/* plan a buffer for entire file */
57 static char	**i_ptr;	/* pointers to lines in i_womp */
58 static char	empty_line[] = { '\0' };
59 
60 static int	tifd = -1;	/* plan b virtual string array */
61 static char	*tibuf[2];	/* plan b buffers */
62 static LINENUM	tiline[2] = {-1, -1};	/* 1st line in each buffer */
63 static size_t	lines_per_buf;	/* how many lines per buffer */
64 static size_t	tibuflen;	/* plan b buffer length */
65 static size_t	tireclen;	/* length of records in tmp file */
66 
67 static bool	rev_in_string(const char *);
68 static bool	reallocate_lines(size_t *);
69 
70 /* returns false if insufficient memory */
71 static bool	plan_a(const char *);
72 
73 static void	plan_b(const char *);
74 
75 /* New patch--prepare to edit another file. */
76 
77 void
78 re_input(void)
79 {
80 	if (using_plan_a) {
81 		free(i_ptr);
82 		i_ptr = NULL;
83 		if (i_womp != NULL) {
84 			munmap(i_womp, i_size);
85 			i_womp = NULL;
86 		}
87 		i_size = 0;
88 	} else {
89 		using_plan_a = true;	/* maybe the next one is smaller */
90 		close(tifd);
91 		tifd = -1;
92 		free(tibuf[0]);
93 		free(tibuf[1]);
94 		tibuf[0] = tibuf[1] = NULL;
95 		tiline[0] = tiline[1] = -1;
96 		tireclen = 0;
97 	}
98 }
99 
100 /* Construct the line index, somehow or other. */
101 
102 void
103 scan_input(const char *filename)
104 {
105 	if (!plan_a(filename))
106 		plan_b(filename);
107 	if (verbose) {
108 		say("Patching file %s using Plan %s...\n", filename,
109 		    (using_plan_a ? "A" : "B"));
110 	}
111 }
112 
113 static bool
114 reallocate_lines(size_t *lines_allocated)
115 {
116 	char	**p;
117 	size_t	new_size;
118 
119 	new_size = *lines_allocated * 3 / 2;
120 	p = reallocarray(i_ptr, new_size + 2, sizeof(char *));
121 	if (p == NULL) {	/* shucks, it was a near thing */
122 		munmap(i_womp, i_size);
123 		i_womp = NULL;
124 		free(i_ptr);
125 		i_ptr = NULL;
126 		*lines_allocated = 0;
127 		return false;
128 	}
129 	*lines_allocated = new_size;
130 	i_ptr = p;
131 	return true;
132 }
133 
134 /* Try keeping everything in memory. */
135 
136 static bool
137 plan_a(const char *filename)
138 {
139 	int		ifd, statfailed;
140 	char		*p, *s;
141 	struct stat	filestat;
142 	ptrdiff_t	sz;
143 	size_t		i;
144 	size_t		iline, lines_allocated;
145 
146 #ifdef DEBUGGING
147 	if (debug & 8)
148 		return false;
149 #endif
150 
151 	if (filename == NULL || *filename == '\0')
152 		return false;
153 
154 	statfailed = stat(filename, &filestat);
155 	if (statfailed && ok_to_create_file) {
156 		if (verbose)
157 			say("(Creating file %s...)\n", filename);
158 
159 		/*
160 		 * in check_patch case, we still display `Creating file' even
161 		 * though we're not. The rule is that -C should be as similar
162 		 * to normal patch behavior as possible
163 		 */
164 		if (check_only)
165 			return true;
166 		makedirs(filename, true);
167 		close(creat(filename, 0666));
168 		statfailed = stat(filename, &filestat);
169 	}
170 	if (statfailed)
171 		fatal("can't find %s\n", filename);
172 	filemode = filestat.st_mode;
173 	if (!S_ISREG(filemode))
174 		fatal("%s is not a normal file--can't patch\n", filename);
175 	if ((uint64_t)filestat.st_size > SIZE_MAX) {
176 		say("block too large to mmap\n");
177 		return false;
178 	}
179 	i_size = (size_t)filestat.st_size;
180 	if (out_of_mem) {
181 		set_hunkmax();	/* make sure dynamic arrays are allocated */
182 		out_of_mem = false;
183 		return false;	/* force plan b because plan a bombed */
184 	}
185 	if ((ifd = open(filename, O_RDONLY)) < 0)
186 		pfatal("can't open file %s", filename);
187 
188 	if (i_size) {
189 		i_womp = mmap(NULL, i_size, PROT_READ, MAP_PRIVATE, ifd, 0);
190 		if (i_womp == MAP_FAILED) {
191 			perror("mmap failed");
192 			i_womp = NULL;
193 			close(ifd);
194 			return false;
195 		}
196 	} else {
197 		i_womp = NULL;
198 	}
199 
200 	close(ifd);
201 	if (i_size)
202 		madvise(i_womp, i_size, MADV_SEQUENTIAL);
203 
204 	/* estimate the number of lines */
205 	lines_allocated = i_size / 25;
206 	if (lines_allocated < 100)
207 		lines_allocated = 100;
208 
209 	if (!reallocate_lines(&lines_allocated))
210 		return false;
211 
212 	/* now scan the buffer and build pointer array */
213 	iline = 1;
214 	i_ptr[iline] = i_womp;
215 	/*
216 	 * Testing for NUL here actively breaks files that innocently use NUL
217 	 * for other reasons. mmap(2) succeeded, just scan the whole buffer.
218 	 */
219 	for (s = i_womp, i = 0; i < i_size; s++, i++) {
220 		if (*s == '\n') {
221 			if (iline == lines_allocated) {
222 				if (!reallocate_lines(&lines_allocated))
223 					return false;
224 			}
225 			/* these are NOT NUL terminated */
226 			i_ptr[++iline] = s + 1;
227 		}
228 	}
229 	/* if the last line contains no EOL, append one */
230 	if (i_size > 0 && i_womp[i_size - 1] != '\n') {
231 		last_line_missing_eol = true;
232 		/* fix last line */
233 		sz = s - i_ptr[iline];
234 		p = malloc(sz + 1);
235 		if (p == NULL) {
236 			free(i_ptr);
237 			i_ptr = NULL;
238 			munmap(i_womp, i_size);
239 			i_womp = NULL;
240 			return false;
241 		}
242 
243 		memcpy(p, i_ptr[iline], sz);
244 		p[sz] = '\n';
245 		i_ptr[iline] = p;
246 		/* count the extra line and make it point to some valid mem */
247 		i_ptr[++iline] = empty_line;
248 	} else
249 		last_line_missing_eol = false;
250 
251 	input_lines = iline - 1;
252 
253 	/* now check for revision, if any */
254 
255 	if (revision != NULL) {
256 		if (i_womp == NULL || !rev_in_string(i_womp)) {
257 			if (force) {
258 				if (verbose)
259 					say("Warning: this file doesn't appear "
260 					    "to be the %s version--patching anyway.\n",
261 					    revision);
262 			} else if (batch) {
263 				fatal("this file doesn't appear to be the "
264 				    "%s version--aborting.\n",
265 				    revision);
266 			} else {
267 				ask("This file doesn't appear to be the "
268 				    "%s version--patch anyway? [n] ",
269 				    revision);
270 				if (*buf != 'y')
271 					fatal("aborted\n");
272 			}
273 		} else if (verbose)
274 			say("Good.  This file appears to be the %s version.\n",
275 			    revision);
276 	}
277 	return true;		/* plan a will work */
278 }
279 
280 /* Keep (virtually) nothing in memory. */
281 
282 static void
283 plan_b(const char *filename)
284 {
285 	FILE	*ifp;
286 	size_t i = 0, j, blen = 0, maxlen = 1;
287 	ssize_t len;
288 	char *p = NULL;
289 	bool	found_revision = (revision == NULL);
290 
291 	using_plan_a = false;
292 	if ((ifp = fopen(filename, "r")) == NULL)
293 		pfatal("can't open file %s", filename);
294 	unlink(TMPINNAME);
295 	if ((tifd = open(TMPINNAME, O_EXCL | O_CREAT | O_WRONLY, 0666)) < 0)
296 		pfatal("can't open file %s", TMPINNAME);
297 	len = 0;
298 	maxlen = 1;
299 	while ((len = getline(&p, &blen, ifp)) >= 0) {
300 		if (p[len - 1] == '\n')
301 			p[len - 1] = '\0';
302 		else {
303 			/* EOF without EOL */
304 			last_line_missing_eol = true;
305 			len++;
306 		}
307 		if (revision != NULL && !found_revision && rev_in_string(p))
308 			found_revision = true;
309 		if ((size_t)len > maxlen)
310 			maxlen = len;   /* find longest line */
311 	}
312 	free(p);
313 	if (ferror(ifp))
314 		pfatal("can't read file %s", filename);
315 
316 	if (revision != NULL) {
317 		if (!found_revision) {
318 			if (force) {
319 				if (verbose)
320 					say("Warning: this file doesn't appear "
321 					    "to be the %s version--patching anyway.\n",
322 					    revision);
323 			} else if (batch) {
324 				fatal("this file doesn't appear to be the "
325 				    "%s version--aborting.\n",
326 				    revision);
327 			} else {
328 				ask("This file doesn't appear to be the %s "
329 				    "version--patch anyway? [n] ",
330 				    revision);
331 				if (*buf != 'y')
332 					fatal("aborted\n");
333 			}
334 		} else if (verbose)
335 			say("Good.  This file appears to be the %s version.\n",
336 			    revision);
337 	}
338 	fseek(ifp, 0L, SEEK_SET);	/* rewind file */
339 	tireclen = maxlen;
340 	tibuflen = maxlen > BUFFERSIZE ? maxlen : BUFFERSIZE;
341 	lines_per_buf = tibuflen / maxlen;
342 	tibuf[0] = malloc(tibuflen + 1);
343 	if (tibuf[0] == NULL)
344 		fatal("out of memory\n");
345 	tibuf[1] = malloc(tibuflen + 1);
346 	if (tibuf[1] == NULL)
347 		fatal("out of memory\n");
348 	for (i = 1;; i++) {
349 		p = tibuf[0] + maxlen * (i % lines_per_buf);
350 		if (i % lines_per_buf == 0)	/* new block */
351 			if (write(tifd, tibuf[0], tibuflen) !=
352 			    (ssize_t) tibuflen)
353 				pfatal("can't write temp file");
354 		if (fgets(p, maxlen + 1, ifp) == NULL) {
355 			input_lines = i - 1;
356 			if (i % lines_per_buf != 0)
357 				if (write(tifd, tibuf[0], tibuflen) !=
358 				    (ssize_t) tibuflen)
359 					pfatal("can't write temp file");
360 			break;
361 		}
362 		j = strlen(p);
363 		/* These are '\n' terminated strings, so no need to add a NUL */
364 		if (j == 0 || p[j - 1] != '\n')
365 			p[j] = '\n';
366 	}
367 	fclose(ifp);
368 	close(tifd);
369 	if ((tifd = open(TMPINNAME, O_RDONLY)) < 0)
370 		pfatal("can't reopen file %s", TMPINNAME);
371 }
372 
373 /*
374  * Fetch a line from the input file, \n terminated, not necessarily \0.
375  */
376 char *
377 ifetch(LINENUM line, int whichbuf)
378 {
379 	if (line < 1 || line > input_lines) {
380 		if (warn_on_invalid_line) {
381 			say("No such line %ld in input file, ignoring\n", line);
382 			warn_on_invalid_line = false;
383 		}
384 		return NULL;
385 	}
386 	if (using_plan_a)
387 		return i_ptr[line];
388 	else {
389 		LINENUM	offline = line % lines_per_buf;
390 		LINENUM	baseline = line - offline;
391 
392 		if (tiline[0] == baseline)
393 			whichbuf = 0;
394 		else if (tiline[1] == baseline)
395 			whichbuf = 1;
396 		else {
397 			tiline[whichbuf] = baseline;
398 
399 			if (lseek(tifd, (off_t) (baseline / lines_per_buf *
400 			    tibuflen), SEEK_SET) < 0)
401 				pfatal("cannot seek in the temporary input file");
402 
403 			if (read(tifd, tibuf[whichbuf], tibuflen) !=
404 			    (ssize_t) tibuflen)
405 				pfatal("error reading tmp file %s", TMPINNAME);
406 		}
407 		return tibuf[whichbuf] + (tireclen * offline);
408 	}
409 }
410 
411 /*
412  * True if the string argument contains the revision number we want.
413  */
414 static bool
415 rev_in_string(const char *string)
416 {
417 	const char	*s;
418 	size_t		patlen;
419 
420 	if (revision == NULL)
421 		return true;
422 	patlen = strlen(revision);
423 	if (strnEQ(string, revision, patlen) && 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