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 1.36 2012/04/10 14:46:34 ajacoutot Exp $
27  * $FreeBSD: stable/10/usr.bin/patch/inp.c 287223 2015-08-27 21:52:09Z delphij $
28  */
29 
30 #include <sys/types.h>
31 #include <sys/file.h>
32 #include <sys/stat.h>
33 #include <sys/mman.h>
34 #include <sys/wait.h>
35 
36 #include <ctype.h>
37 #include <errno.h>
38 #include <libgen.h>
39 #include <paths.h>
40 #include <spawn.h>
41 #include <stddef.h>
42 #include <stdint.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
46 #include <unistd.h>
47 
48 #include "common.h"
49 #include "util.h"
50 #include "pch.h"
51 #include "inp.h"
52 
53 
54 /* Input-file-with-indexable-lines abstract type */
55 
56 static size_t	i_size;		/* size of the input file */
57 static char	*i_womp;	/* plan a buffer for entire file */
58 static char	**i_ptr;	/* pointers to lines in i_womp */
59 static char	empty_line[] = { '\0' };
60 
61 static int	tifd = -1;	/* plan b virtual string array */
62 static char	*tibuf[2];	/* plan b buffers */
63 static LINENUM	tiline[2] = {-1, -1};	/* 1st line in each buffer */
64 static LINENUM	lines_per_buf;	/* how many lines per buffer */
65 static int	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
re_input(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
scan_input(const char * filename)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
reallocate_lines(size_t * lines_allocated)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 = realloc(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
plan_a(const char * filename)137 plan_a(const char *filename)
138 {
139 	int		ifd, statfailed, pstat;
140 	char		*p, *s, lbuf[INITLINELEN];
141 	struct stat	filestat;
142 	ptrdiff_t	sz;
143 	size_t		i;
144 	size_t		iline, lines_allocated;
145 	pid_t		pid;
146 
147 #ifdef DEBUGGING
148 	if (debug & 8)
149 		return false;
150 #endif
151 
152 	if (filename == NULL || *filename == '\0')
153 		return false;
154 
155 	statfailed = stat(filename, &filestat);
156 	if (statfailed && ok_to_create_file) {
157 		if (verbose)
158 			say("(Creating file %s...)\n", filename);
159 
160 		/*
161 		 * in check_patch case, we still display `Creating file' even
162 		 * though we're not. The rule is that -C should be as similar
163 		 * to normal patch behavior as possible
164 		 */
165 		if (check_only)
166 			return true;
167 		makedirs(filename, true);
168 		close(creat(filename, 0666));
169 		statfailed = stat(filename, &filestat);
170 	}
171 	if (statfailed && check_only)
172 		fatal("%s not found, -C mode, can't probe further\n", filename);
173 	/* For nonexistent or read-only files, look for RCS versions.  */
174 
175 	if (statfailed ||
176 	    /* No one can write to it.  */
177 	    (filestat.st_mode & 0222) == 0 ||
178 	    /* I can't write to it.  */
179 	    ((filestat.st_mode & 0022) == 0 && filestat.st_uid != getuid())) {
180 		char	*filebase, *filedir;
181 		struct stat	cstat;
182 		char	*tmp_filename1, *tmp_filename2;
183 		char	*argp[4] = { NULL };
184 		posix_spawn_file_actions_t file_actions;
185 
186 		tmp_filename1 = strdup(filename);
187 		tmp_filename2 = strdup(filename);
188 		if (tmp_filename1 == NULL || tmp_filename2 == NULL)
189 			fatal("strdupping filename");
190 
191 		filebase = basename(tmp_filename1);
192 		filedir = dirname(tmp_filename2);
193 
194 		memset(argp, 0, sizeof(argp));
195 
196 #define try(f, a1, a2, a3) \
197 	(snprintf(lbuf, sizeof(lbuf), f, a1, a2, a3), stat(lbuf, &cstat) == 0)
198 
199 		/*
200 		 * else we can't write to it but it's not under a version
201 		 * control system, so just proceed.
202 		 */
203 		if (try("%s/RCS/%s%s", filedir, filebase, RCSSUFFIX) ||
204 		    try("%s/RCS/%s%s", filedir, filebase, "") ||
205 		    try("%s/%s%s", filedir, filebase, RCSSUFFIX)) {
206 			if (!statfailed) {
207 				if ((filestat.st_mode & 0222) != 0)
208 					/* The owner can write to it.  */
209 					fatal("file %s seems to be locked "
210 					    "by somebody else under RCS\n",
211 					    filename);
212 				/*
213 				 * It might be checked out unlocked.  See if
214 				 * it's safe to check out the default version
215 				 * locked.
216 				 */
217 				if (verbose)
218 					say("Comparing file %s to default "
219 					    "RCS version...\n", filename);
220 
221 				argp[0] = __DECONST(char *, RCSDIFF);
222 				argp[1] = __DECONST(char *, filename);
223 				posix_spawn_file_actions_init(&file_actions);
224 				posix_spawn_file_actions_addopen(&file_actions,
225 				    STDOUT_FILENO, _PATH_DEVNULL, O_WRONLY, 0);
226 				if (posix_spawn(&pid, RCSDIFF, &file_actions,
227 				    NULL, argp, NULL) == 0) {
228 					pid = waitpid(pid, &pstat, 0);
229 					if (pid == -1 || WEXITSTATUS(pstat) != 0)
230 						fatal("can't check out file %s: "
231 						    "differs from default RCS version\n",
232 						    filename);
233 				} else
234 					fatal("posix_spawn: %s\n", strerror(errno));
235 				posix_spawn_file_actions_destroy(&file_actions);
236 			}
237 
238 			if (verbose)
239 				say("Checking out file %s from RCS...\n",
240 				    filename);
241 
242 			argp[0] = __DECONST(char *, CHECKOUT);
243 			argp[1] = __DECONST(char *, "-l");
244 			argp[2] = __DECONST(char *, filename);
245 			if (posix_spawn(&pid, CHECKOUT, NULL, NULL, argp,
246 			    NULL) == 0) {
247 				pid = waitpid(pid, &pstat, 0);
248 				if (pid == -1 || WEXITSTATUS(pstat) != 0 ||
249 				    stat(filename, &filestat))
250 					fatal("can't check out file %s from RCS\n",
251 					    filename);
252 			} else
253 				fatal("posix_spawn: %s\n", strerror(errno));
254 		} else if (statfailed) {
255 			fatal("can't find %s\n", filename);
256 		}
257 		free(tmp_filename1);
258 		free(tmp_filename2);
259 	}
260 
261 	filemode = filestat.st_mode;
262 	if (!S_ISREG(filemode))
263 		fatal("%s is not a normal file--can't patch\n", filename);
264 	if ((uint64_t)filestat.st_size > SIZE_MAX) {
265 		say("block too large to mmap\n");
266 		return false;
267 	}
268 	i_size = (size_t)filestat.st_size;
269 	if (out_of_mem) {
270 		set_hunkmax();	/* make sure dynamic arrays are allocated */
271 		out_of_mem = false;
272 		return false;	/* force plan b because plan a bombed */
273 	}
274 	if ((ifd = open(filename, O_RDONLY)) < 0)
275 		pfatal("can't open file %s", filename);
276 
277 	if (i_size) {
278 		i_womp = mmap(NULL, i_size, PROT_READ, MAP_PRIVATE, ifd, 0);
279 		if (i_womp == MAP_FAILED) {
280 			perror("mmap failed");
281 			i_womp = NULL;
282 			close(ifd);
283 			return false;
284 		}
285 	} else {
286 		i_womp = NULL;
287 	}
288 
289 	close(ifd);
290 	if (i_size)
291 		madvise(i_womp, i_size, MADV_SEQUENTIAL);
292 
293 	/* estimate the number of lines */
294 	lines_allocated = i_size / 25;
295 	if (lines_allocated < 100)
296 		lines_allocated = 100;
297 
298 	if (!reallocate_lines(&lines_allocated))
299 		return false;
300 
301 	/* now scan the buffer and build pointer array */
302 	iline = 1;
303 	i_ptr[iline] = i_womp;
304 	/* test for NUL too, to maintain the behavior of the original code */
305 	for (s = i_womp, i = 0; i < i_size && *s != '\0'; s++, i++) {
306 		if (*s == '\n') {
307 			if (iline == lines_allocated) {
308 				if (!reallocate_lines(&lines_allocated))
309 					return false;
310 			}
311 			/* these are NOT NUL terminated */
312 			i_ptr[++iline] = s + 1;
313 		}
314 	}
315 	/* if the last line contains no EOL, append one */
316 	if (i_size > 0 && i_womp[i_size - 1] != '\n') {
317 		last_line_missing_eol = true;
318 		/* fix last line */
319 		sz = s - i_ptr[iline];
320 		p = malloc(sz + 1);
321 		if (p == NULL) {
322 			free(i_ptr);
323 			i_ptr = NULL;
324 			munmap(i_womp, i_size);
325 			i_womp = NULL;
326 			return false;
327 		}
328 
329 		memcpy(p, i_ptr[iline], sz);
330 		p[sz] = '\n';
331 		i_ptr[iline] = p;
332 		/* count the extra line and make it point to some valid mem */
333 		i_ptr[++iline] = empty_line;
334 	} else
335 		last_line_missing_eol = false;
336 
337 	input_lines = iline - 1;
338 
339 	/* now check for revision, if any */
340 
341 	if (revision != NULL) {
342 		if (!rev_in_string(i_womp)) {
343 			if (force) {
344 				if (verbose)
345 					say("Warning: this file doesn't appear "
346 					    "to be the %s version--patching anyway.\n",
347 					    revision);
348 			} else if (batch) {
349 				fatal("this file doesn't appear to be the "
350 				    "%s version--aborting.\n",
351 				    revision);
352 			} else {
353 				ask("This file doesn't appear to be the "
354 				    "%s version--patch anyway? [n] ",
355 				    revision);
356 				if (*buf != 'y')
357 					fatal("aborted\n");
358 			}
359 		} else if (verbose)
360 			say("Good.  This file appears to be the %s version.\n",
361 			    revision);
362 	}
363 	return true;		/* plan a will work */
364 }
365 
366 /* Keep (virtually) nothing in memory. */
367 
368 static void
plan_b(const char * filename)369 plan_b(const char *filename)
370 {
371 	FILE	*ifp;
372 	size_t	i = 0, j, maxlen = 1;
373 	char	*p;
374 	bool	found_revision = (revision == NULL);
375 
376 	using_plan_a = false;
377 	if ((ifp = fopen(filename, "r")) == NULL)
378 		pfatal("can't open file %s", filename);
379 	unlink(TMPINNAME);
380 	if ((tifd = open(TMPINNAME, O_EXCL | O_CREAT | O_WRONLY, 0666)) < 0)
381 		pfatal("can't open file %s", TMPINNAME);
382 	while (fgets(buf, buf_size, ifp) != NULL) {
383 		if (revision != NULL && !found_revision && rev_in_string(buf))
384 			found_revision = true;
385 		if ((i = strlen(buf)) > maxlen)
386 			maxlen = i;	/* find longest line */
387 	}
388 	last_line_missing_eol = i > 0 && buf[i - 1] != '\n';
389 	if (last_line_missing_eol && maxlen == i)
390 		maxlen++;
391 
392 	if (revision != NULL) {
393 		if (!found_revision) {
394 			if (force) {
395 				if (verbose)
396 					say("Warning: this file doesn't appear "
397 					    "to be the %s version--patching anyway.\n",
398 					    revision);
399 			} else if (batch) {
400 				fatal("this file doesn't appear to be the "
401 				    "%s version--aborting.\n",
402 				    revision);
403 			} else {
404 				ask("This file doesn't appear to be the %s "
405 				    "version--patch anyway? [n] ",
406 				    revision);
407 				if (*buf != 'y')
408 					fatal("aborted\n");
409 			}
410 		} else if (verbose)
411 			say("Good.  This file appears to be the %s version.\n",
412 			    revision);
413 	}
414 	fseek(ifp, 0L, SEEK_SET);	/* rewind file */
415 	lines_per_buf = BUFFERSIZE / maxlen;
416 	tireclen = maxlen;
417 	tibuf[0] = malloc(BUFFERSIZE + 1);
418 	if (tibuf[0] == NULL)
419 		fatal("out of memory\n");
420 	tibuf[1] = malloc(BUFFERSIZE + 1);
421 	if (tibuf[1] == NULL)
422 		fatal("out of memory\n");
423 	for (i = 1;; i++) {
424 		p = tibuf[0] + maxlen * (i % lines_per_buf);
425 		if (i % lines_per_buf == 0)	/* new block */
426 			if (write(tifd, tibuf[0], BUFFERSIZE) < BUFFERSIZE)
427 				pfatal("can't write temp file");
428 		if (fgets(p, maxlen + 1, ifp) == NULL) {
429 			input_lines = i - 1;
430 			if (i % lines_per_buf != 0)
431 				if (write(tifd, tibuf[0], BUFFERSIZE) < BUFFERSIZE)
432 					pfatal("can't write temp file");
433 			break;
434 		}
435 		j = strlen(p);
436 		/* These are '\n' terminated strings, so no need to add a NUL */
437 		if (j == 0 || p[j - 1] != '\n')
438 			p[j] = '\n';
439 	}
440 	fclose(ifp);
441 	close(tifd);
442 	if ((tifd = open(TMPINNAME, O_RDONLY)) < 0)
443 		pfatal("can't reopen file %s", TMPINNAME);
444 }
445 
446 /*
447  * Fetch a line from the input file, \n terminated, not necessarily \0.
448  */
449 char *
ifetch(LINENUM line,int whichbuf)450 ifetch(LINENUM line, int whichbuf)
451 {
452 	if (line < 1 || line > input_lines) {
453 		if (warn_on_invalid_line) {
454 			say("No such line %ld in input file, ignoring\n", line);
455 			warn_on_invalid_line = false;
456 		}
457 		return NULL;
458 	}
459 	if (using_plan_a)
460 		return i_ptr[line];
461 	else {
462 		LINENUM	offline = line % lines_per_buf;
463 		LINENUM	baseline = line - offline;
464 
465 		if (tiline[0] == baseline)
466 			whichbuf = 0;
467 		else if (tiline[1] == baseline)
468 			whichbuf = 1;
469 		else {
470 			tiline[whichbuf] = baseline;
471 
472 			if (lseek(tifd, (off_t) (baseline / lines_per_buf *
473 			    BUFFERSIZE), SEEK_SET) < 0)
474 				pfatal("cannot seek in the temporary input file");
475 
476 			if (read(tifd, tibuf[whichbuf], BUFFERSIZE) < 0)
477 				pfatal("error reading tmp file %s", TMPINNAME);
478 		}
479 		return tibuf[whichbuf] + (tireclen * offline);
480 	}
481 }
482 
483 /*
484  * True if the string argument contains the revision number we want.
485  */
486 static bool
rev_in_string(const char * string)487 rev_in_string(const char *string)
488 {
489 	const char	*s;
490 	size_t		patlen;
491 
492 	if (revision == NULL)
493 		return true;
494 	patlen = strlen(revision);
495 	if (strnEQ(string, revision, patlen) && isspace((unsigned char)string[patlen]))
496 		return true;
497 	for (s = string; *s; s++) {
498 		if (isspace((unsigned char)*s) && strnEQ(s + 1, revision, patlen) &&
499 		    isspace((unsigned char)s[patlen + 1])) {
500 			return true;
501 		}
502 	}
503 	return false;
504 }
505