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Date:: Sun Mar 13 21:25:37 2022 UTC
Message:: got-read-patch: plug memory leak
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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 
22 /*
23  * Copyright (c) 2022 Omar Polo <op@openbsd.org>
24  *
25  * Permission to use, copy, modify, and distribute this software for any
26  * purpose with or without fee is hereby granted, provided that the above
27  * copyright notice and this permission notice appear in all copies.
28  *
29  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
30  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
31  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
32  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
33  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
34  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
35  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
36  */
37 
38 #include <sys/types.h>
39 #include <sys/uio.h>
40 
41 #include <ctype.h>
42 #include <limits.h>
43 #include <paths.h>
44 #include <stdint.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include <unistd.h>
49 
50 #include "got_error.h"
51 #include "got_object.h"
52 
53 #include "got_compat.h"
54 
55 #include "got_lib_delta.h"
56 #include "got_lib_object.h"
57 #include "got_lib_privsep.h"
58 
59 struct imsgbuf ibuf;
60 
61 static const struct got_error *
62 send_patch(const char *oldname, const char *newname)
63 {
64 	struct got_imsg_patch p;
65 
66 	memset(&p, 0, sizeof(p));
67 
68 	if (oldname != NULL)
69 		strlcpy(p.old, oldname, sizeof(p.old));
70 	if (newname != NULL)
71 		strlcpy(p.new, newname, sizeof(p.new));
72 
73 	if (imsg_compose(&ibuf, GOT_IMSG_PATCH, 0, 0, -1,
74 	    &p, sizeof(p)) == -1)
75 		return got_error_from_errno("imsg_compose GOT_IMSG_PATCH");
76 	return NULL;
77 }
78 
79 static const struct got_error *
80 send_patch_done(void)
81 {
82 	if (imsg_compose(&ibuf, GOT_IMSG_PATCH_DONE, 0, 0, -1,
83 	    NULL, 0) == -1)
84 		return got_error_from_errno("imsg_compose GOT_IMSG_PATCH_EOF");
85 	if (imsg_flush(&ibuf) == -1)
86 		return got_error_from_errno("imsg_flush");
87 	return NULL;
88 }
89 
90 /* based on fetchname from usr.bin/patch/util.c */
91 static const struct got_error *
92 filename(const char *at, char **name, int strip)
93 {
94 	char	*fullname, *t;
95 	int	 l, tab;
96 
97 	*name = NULL;
98 	if (*at == '\0')
99 		return NULL;
100 
101 	while (isspace((unsigned char)*at))
102 		at++;
103 
104 	/* files can be created or removed by diffing against /dev/null */
105 	if (!strncmp(at, _PATH_DEVNULL, sizeof(_PATH_DEVNULL)-1))
106 		return NULL;
107 
108 	t = strdup(at);
109 	if (t == NULL)
110 		return got_error_from_errno("strdup");
111 	*name = fullname = t;
112 	tab = strchr(t, '\t') != NULL;
113 
114 	/* strip off path components and NUL-terminate */
115 	for (l = strip;
116 	    *t != '\0' && ((tab && *t != '\t') || !isspace((unsigned char)*t));
117 	    ++t) {
118 		if (t[0] == '/' && t[1] != '/' && t[1] != '\0')
119 			if (--l >= 0)
120 				*name = t+1;
121 	}
122 	*t = '\0';
123 
124 	*name = strdup(*name);
125 	free(fullname);
126 	if (*name == NULL)
127 		return got_error_from_errno("strdup");
128 	return NULL;
129 }
130 
131 static const struct got_error *
132 find_patch(FILE *fp)
133 {
134 	const struct got_error *err = NULL;
135 	char	*old = NULL, *new = NULL;
136 	char	*line = NULL;
137 	size_t	 linesize = 0;
138 	ssize_t	 linelen;
139 	int	 create, git = 0;
140 
141 	while ((linelen = getline(&line, &linesize, fp)) != -1) {
142 		/*
143 		 * Ignore the Index name like GNU and larry' patch,
144 		 * we don't have to follow POSIX.
145 		 */
146 
147 		if (git && !strncmp(line, "--- a/", 6)) {
148 			free(old);
149 			err = filename(line+6, &old, 0);
150 		} else if (!strncmp(line, "--- ", 4)) {
151 			free(old);
152 			err = filename(line+4, &old, 0);
153 		} else if (git && !strncmp(line, "+++ b/", 6)) {
154 			free(new);
155 			err = filename(line+6, &new, 0);
156 		} else if (!strncmp(line, "+++ ", 4)) {
157 			free(new);
158 			err = filename(line+4, &new, 0);
159 		} else if (!strncmp(line, "diff --git a/", 13))
160 			git = 1;
161 
162 		if (err)
163 			break;
164 
165 		if (!strncmp(line, "@@ -", 4)) {
166 			create = !strncmp(line+4, "0,0", 3);
167 			if ((old == NULL && new == NULL) ||
168 			    (!create && old == NULL))
169 				err = got_error(GOT_ERR_PATCH_MALFORMED);
170 			else
171 				err = send_patch(old, new);
172 
173 			if (err)
174 				break;
175 
176 			/* rewind to previous line */
177 			if (fseek(fp, linelen * -1, SEEK_CUR) == -1)
178 				err = got_error_from_errno("fseek");
179 			break;
180 		}
181 	}
182 
183 	free(old);
184 	free(new);
185 	free(line);
186 	if (ferror(fp) && err == NULL)
187 		err = got_error_from_errno("getline");
188 	if (feof(fp) && err == NULL)
189 		err = got_error(GOT_ERR_NO_PATCH);
190 	return err;
191 }
192 
193 static const struct got_error *
194 strtolnum(char **str, long *n)
195 {
196 	char		*p, c;
197 	const char	*errstr;
198 
199 	for (p = *str; isdigit((unsigned char)*p); ++p)
200 		/* nop */;
201 
202 	c = *p;
203 	*p = '\0';
204 
205 	*n = strtonum(*str, 0, LONG_MAX, &errstr);
206 	if (errstr != NULL)
207 		return got_error(GOT_ERR_PATCH_MALFORMED);
208 
209 	*p = c;
210 	*str = p;
211 	return NULL;
212 }
213 
214 static const struct got_error *
215 parse_hdr(char *s, int *ok, struct got_imsg_patch_hunk *hdr)
216 {
217 	static const struct got_error *err = NULL;
218 
219 	*ok = 1;
220 	if (strncmp(s, "@@ -", 4)) {
221 		*ok = 0;
222 		return NULL;
223 	}
224 
225 	s += 4;
226 	if (!*s)
227 		return NULL;
228 	err = strtolnum(&s, &hdr->oldfrom);
229 	if (err)
230 		return err;
231 	if (*s == ',') {
232 		s++;
233 		err = strtolnum(&s, &hdr->oldlines);
234 		if (err)
235 			return err;
236 	} else
237 		hdr->oldlines = 1;
238 
239 	if (*s == ' ')
240 		s++;
241 
242 	if (*s != '+' || !*++s)
243 		return got_error(GOT_ERR_PATCH_MALFORMED);
244 	err = strtolnum(&s, &hdr->newfrom);
245 	if (err)
246 		return err;
247 	if (*s == ',') {
248 		s++;
249 		err = strtolnum(&s, &hdr->newlines);
250 		if (err)
251 			return err;
252 	} else
253 		hdr->newlines = 1;
254 
255 	if (*s == ' ')
256 		s++;
257 
258 	if (*s != '@')
259 		return got_error(GOT_ERR_PATCH_MALFORMED);
260 
261 	if (hdr->oldfrom >= LONG_MAX - hdr->oldlines ||
262 	    hdr->newfrom >= LONG_MAX - hdr->newlines ||
263 	    /* not so sure about this one */
264 	    hdr->oldlines >= LONG_MAX - hdr->newlines - 1)
265 		return got_error(GOT_ERR_PATCH_MALFORMED);
266 
267 	if (hdr->oldlines == 0) {
268 		/* larry says to "do append rather than insert"; I don't
269 		 * quite get it, but i trust him.
270 		 */
271 		hdr->oldfrom++;
272 	}
273 
274 	if (imsg_compose(&ibuf, GOT_IMSG_PATCH_HUNK, 0, 0, -1,
275 	    hdr, sizeof(*hdr)) == -1)
276 		return got_error_from_errno(
277 		    "imsg_compose GOT_IMSG_PATCH_HUNK");
278 	return NULL;
279 }
280 
281 static const struct got_error *
282 send_line(const char *line)
283 {
284 	static const struct got_error *err = NULL;
285 	char *p = NULL;
286 
287 	if (*line != '+' && *line != '-' && *line != ' ') {
288 		if (asprintf(&p, " %s", line) == -1)
289 			return got_error_from_errno("asprintf");
290 		line = p;
291 	}
292 
293 	if (imsg_compose(&ibuf, GOT_IMSG_PATCH_LINE, 0, 0, -1,
294 	    line, strlen(line)+1) == -1)
295 		err = got_error_from_errno(
296 		    "imsg_compose GOT_IMSG_PATCH_LINE");
297 
298 	free(p);
299 	return err;
300 }
301 
302 static const struct got_error *
303 parse_hunk(FILE *fp, int *ok)
304 {
305 	static const struct got_error *err = NULL;
306 	struct got_imsg_patch_hunk hdr;
307 	char	*line = NULL, ch;
308 	size_t	 linesize = 0;
309 	ssize_t	 linelen;
310 	long	 leftold, leftnew;
311 
312 	linelen = getline(&line, &linesize, fp);
313 	if (linelen == -1) {
314 		*ok = 0;
315 		goto done;
316 	}
317 
318 	err = parse_hdr(line, ok, &hdr);
319 	if (err)
320 		goto done;
321 	if (!*ok) {
322 		if (fseek(fp, linelen * -1, SEEK_CUR) == -1)
323 			err = got_error_from_errno("fseek");
324 		goto done;
325 	}
326 
327 	leftold = hdr.oldlines;
328 	leftnew = hdr.newlines;
329 
330 	while (leftold > 0 || leftnew > 0) {
331 		linelen = getline(&line, &linesize, fp);
332 		if (linelen == -1) {
333 			if (ferror(fp)) {
334 				err = got_error_from_errno("getline");
335 				goto done;
336 			}
337 
338 			/* trailing newlines may be chopped */
339 			if (leftold < 3 && leftnew < 3) {
340 				*ok = 0;
341 				break;
342 			}
343 
344 			err = got_error(GOT_ERR_PATCH_TRUNCATED);
345 			goto done;
346 		}
347 
348 		/* usr.bin/patch allows '=' as context char */
349 		if (*line == '=')
350 			*line = ' ';
351 
352 		ch = *line;
353 		if (ch == '\t' || ch == '\n')
354 			ch = ' ';	/* the space got eaten */
355 
356 		switch (ch) {
357 		case '-':
358 			leftold--;
359 			break;
360 		case ' ':
361 			leftold--;
362 			leftnew--;
363 			break;
364 		case '+':
365 			leftnew--;
366 			break;
367 		default:
368 			err = got_error(GOT_ERR_PATCH_MALFORMED);
369 			goto done;
370 		}
371 
372 		if (leftold < 0 || leftnew < 0) {
373 			err = got_error(GOT_ERR_PATCH_MALFORMED);
374 			goto done;
375 		}
376 
377 		err = send_line(line);
378 		if (err)
379 			goto done;
380 	}
381 
382 done:
383 	free(line);
384 	return err;
385 }
386 
387 static const struct got_error *
388 read_patch(struct imsgbuf *ibuf, int fd)
389 {
390 	const struct got_error *err = NULL;
391 	FILE *fp;
392 	int ok, patch_found = 0;
393 
394 	if ((fp = fdopen(fd, "r")) == NULL) {
395 		err = got_error_from_errno("fdopen");
396 		close(fd);
397 		return err;
398 	}
399 
400 	while (!feof(fp)) {
401 		err = find_patch(fp);
402 		if (err)
403 			goto done;
404 
405 		patch_found = 1;
406 		for (;;) {
407 			err = parse_hunk(fp, &ok);
408 			if (err)
409 				goto done;
410 			if (!ok) {
411 				err = send_patch_done();
412 				if (err)
413 					goto done;
414 				break;
415 			}
416 		}
417 	}
418 
419 done:
420 	fclose(fp);
421 
422 	/* ignore trailing gibberish */
423 	if (err != NULL && err->code == GOT_ERR_NO_PATCH && patch_found)
424 		err = NULL;
425 
426 	return err;
427 }
428 
429 int
430 main(int argc, char **argv)
431 {
432 	const struct got_error *err = NULL;
433 	struct imsg imsg;
434 #if 0
435 	static int attached;
436 	while (!attached)
437 		sleep(1);
438 #endif
439 
440 	imsg_init(&ibuf, GOT_IMSG_FD_CHILD);
441 #ifndef PROFILE
442 	/* revoke access to most system calls */
443 	if (pledge("stdio recvfd", NULL) == -1) {
444 		err = got_error_from_errno("pledge");
445 		got_privsep_send_error(&ibuf, err);
446 		return 1;
447 	}
448 
449 	/* revoke fs access */
450 	if (landlock_no_fs() == -1) {
451 		err = got_error_from_errno("landlock_no_fs");
452 		got_privsep_send_error(&ibuf, err);
453 		return 1;
454 	}
455 #endif
456 
457 	err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
458 	if (err)
459 		goto done;
460 	if (imsg.hdr.type != GOT_IMSG_PATCH_FILE || imsg.fd == -1) {
461 		err = got_error(GOT_ERR_PRIVSEP_MSG);
462 		goto done;
463 	}
464 
465 	err = read_patch(&ibuf, imsg.fd);
466 	if (err)
467 		goto done;
468 	if (imsg_compose(&ibuf, GOT_IMSG_PATCH_EOF, 0, 0, -1,
469 	    NULL, 0) == -1) {
470 		err = got_error_from_errno("imsg_compose GOT_IMSG_PATCH_EOF");
471 		goto done;
472 	}
473 	err = got_privsep_flush_imsg(&ibuf);
474 done:
475 	imsg_free(&imsg);
476 	if (err != NULL) {
477 		got_privsep_send_error(&ibuf, err);
478 		err = NULL;
479 	}
480 	if (close(GOT_IMSG_FD_CHILD) == -1 && err == NULL)
481 		err = got_error_from_errno("close");
482 	if (err && err->code != GOT_ERR_PRIVSEP_PIPE)
483 		fprintf(stderr, "%s: %s\n", getprogname(), err->msg);
484 	return err ? 1 : 0;
485 }