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Date:: Sat Mar 12 16:01:09 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/queue.h>
40 #include <sys/uio.h>
41 
42 #include <ctype.h>
43 #include <limits.h>
44 #include <paths.h>
45 #include <sha1.h>
46 #include <stdint.h>
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <string.h>
50 #include <unistd.h>
51 #include <imsg.h>
52 
53 #include "got_error.h"
54 #include "got_object.h"
55 
56 #include "got_lib_delta.h"
57 #include "got_lib_object.h"
58 #include "got_lib_privsep.h"
59 
60 struct imsgbuf ibuf;
61 
62 static const struct got_error *
63 send_patch(const char *oldname, const char *newname)
64 {
65 	struct got_imsg_patch p;
66 
67 	memset(&p, 0, sizeof(p));
68 
69 	if (oldname != NULL)
70 		strlcpy(p.old, oldname, sizeof(p.old));
71 	if (newname != NULL)
72 		strlcpy(p.new, newname, sizeof(p.new));
73 
74 	if (imsg_compose(&ibuf, GOT_IMSG_PATCH, 0, 0, -1,
75 	    &p, sizeof(p)) == -1)
76 		return got_error_from_errno("imsg_compose GOT_IMSG_PATCH");
77 	return NULL;
78 }
79 
80 static const struct got_error *
81 send_patch_done(void)
82 {
83 	if (imsg_compose(&ibuf, GOT_IMSG_PATCH_DONE, 0, 0, -1,
84 	    NULL, 0) == -1)
85 		return got_error_from_errno("imsg_compose GOT_IMSG_PATCH_EOF");
86 	if (imsg_flush(&ibuf) == -1)
87 		return got_error_from_errno("imsg_flush");
88 	return NULL;
89 }
90 
91 /* based on fetchname from usr.bin/patch/util.c */
92 static const struct got_error *
93 filename(const char *at, char **name, int strip)
94 {
95 	char	*fullname, *t;
96 	int	 l, tab;
97 
98 	*name = NULL;
99 	if (*at == '\0')
100 		return NULL;
101 
102 	while (isspace((unsigned char)*at))
103 		at++;
104 
105 	/* files can be created or removed by diffing against /dev/null */
106 	if (!strncmp(at, _PATH_DEVNULL, sizeof(_PATH_DEVNULL)-1))
107 		return NULL;
108 
109 	t = strdup(at);
110 	if (t == NULL)
111 		return got_error_from_errno("strdup");
112 	*name = fullname = t;
113 	tab = strchr(t, '\t') != NULL;
114 
115 	/* strip off path components and NUL-terminate */
116 	for (l = strip;
117 	    *t != '\0' && ((tab && *t != '\t') || !isspace((unsigned char)*t));
118 	    ++t) {
119 		if (t[0] == '/' && t[1] != '/' && t[1] != '\0')
120 			if (--l >= 0)
121 				*name = t+1;
122 	}
123 	*t = '\0';
124 
125 	*name = strdup(*name);
126 	free(fullname);
127 	if (*name == NULL)
128 		return got_error_from_errno("strdup");
129 	return NULL;
130 }
131 
132 static const struct got_error *
133 find_patch(FILE *fp)
134 {
135 	const struct got_error *err = NULL;
136 	char	*old = NULL, *new = NULL;
137 	char	*line = NULL;
138 	size_t	 linesize = 0;
139 	ssize_t	 linelen;
140 	int	 create, git = 0;
141 
142 	while ((linelen = getline(&line, &linesize, fp)) != -1) {
143 		/*
144 		 * Ignore the Index name like GNU and larry' patch,
145 		 * we don't have to follow POSIX.
146 		 */
147 
148 		if (git && !strncmp(line, "--- a/", 6)) {
149 			free(old);
150 			err = filename(line+6, &old, 0);
151 		} else if (!strncmp(line, "--- ", 4)) {
152 			free(old);
153 			err = filename(line+4, &old, 0);
154 		} else if (git && !strncmp(line, "+++ b/", 6)) {
155 			free(new);
156 			err = filename(line+6, &new, 0);
157 		} else if (!strncmp(line, "+++ ", 4)) {
158 			free(new);
159 			err = filename(line+4, &new, 0);
160 		} else if (!strncmp(line, "diff --git a/", 13))
161 			git = 1;
162 
163 		if (err)
164 			break;
165 
166 		if (!strncmp(line, "@@ -", 4)) {
167 			create = !strncmp(line+4, "0,0", 3);
168 			if ((old == NULL && new == NULL) ||
169 			    (!create && old == NULL))
170 				err = got_error(GOT_ERR_PATCH_MALFORMED);
171 			else
172 				err = send_patch(old, new);
173 
174 			if (err)
175 				break;
176 
177 			/* rewind to previous line */
178 			if (fseek(fp, linelen * -1, SEEK_CUR) == -1)
179 				err = got_error_from_errno("fseek");
180 			break;
181 		}
182 	}
183 
184 	free(old);
185 	free(new);
186 	free(line);
187 	if (ferror(fp) && err == NULL)
188 		err = got_error_from_errno("getline");
189 	if (feof(fp) && err == NULL)
190 		err = got_error(GOT_ERR_NO_PATCH);
191 	return err;
192 }
193 
194 static const struct got_error *
195 strtolnum(char **str, long *n)
196 {
197 	char		*p, c;
198 	const char	*errstr;
199 
200 	for (p = *str; isdigit((unsigned char)*p); ++p)
201 		/* nop */;
202 
203 	c = *p;
204 	*p = '\0';
205 
206 	*n = strtonum(*str, 0, LONG_MAX, &errstr);
207 	if (errstr != NULL)
208 		return got_error(GOT_ERR_PATCH_MALFORMED);
209 
210 	*p = c;
211 	*str = p;
212 	return NULL;
213 }
214 
215 static const struct got_error *
216 parse_hdr(char *s, int *ok, struct got_imsg_patch_hunk *hdr)
217 {
218 	static const struct got_error *err = NULL;
219 
220 	*ok = 1;
221 	if (strncmp(s, "@@ -", 4)) {
222 		*ok = 0;
223 		return NULL;
224 	}
225 
226 	s += 4;
227 	if (!*s)
228 		return NULL;
229 	err = strtolnum(&s, &hdr->oldfrom);
230 	if (err)
231 		return err;
232 	if (*s == ',') {
233 		s++;
234 		err = strtolnum(&s, &hdr->oldlines);
235 		if (err)
236 			return err;
237 	} else
238 		hdr->oldlines = 1;
239 
240 	if (*s == ' ')
241 		s++;
242 
243 	if (*s != '+' || !*++s)
244 		return got_error(GOT_ERR_PATCH_MALFORMED);
245 	err = strtolnum(&s, &hdr->newfrom);
246 	if (err)
247 		return err;
248 	if (*s == ',') {
249 		s++;
250 		err = strtolnum(&s, &hdr->newlines);
251 		if (err)
252 			return err;
253 	} else
254 		hdr->newlines = 1;
255 
256 	if (*s == ' ')
257 		s++;
258 
259 	if (*s != '@')
260 		return got_error(GOT_ERR_PATCH_MALFORMED);
261 
262 	if (hdr->oldfrom >= LONG_MAX - hdr->oldlines ||
263 	    hdr->newfrom >= LONG_MAX - hdr->newlines ||
264 	    /* not so sure about this one */
265 	    hdr->oldlines >= LONG_MAX - hdr->newlines - 1)
266 		return got_error(GOT_ERR_PATCH_MALFORMED);
267 
268 	if (hdr->oldlines == 0) {
269 		/* larry says to "do append rather than insert"; I don't
270 		 * quite get it, but i trust him.
271 		 */
272 		hdr->oldfrom++;
273 	}
274 
275 	if (imsg_compose(&ibuf, GOT_IMSG_PATCH_HUNK, 0, 0, -1,
276 	    hdr, sizeof(*hdr)) == -1)
277 		return got_error_from_errno(
278 		    "imsg_compose GOT_IMSG_PATCH_HUNK");
279 	return NULL;
280 }
281 
282 static const struct got_error *
283 send_line(const char *line)
284 {
285 	static const struct got_error *err = NULL;
286 	char *p = NULL;
287 
288 	if (*line != '+' && *line != '-' && *line != ' ') {
289 		if (asprintf(&p, " %s", line) == -1)
290 			return got_error_from_errno("asprintf");
291 		line = p;
292 	}
293 
294 	if (imsg_compose(&ibuf, GOT_IMSG_PATCH_LINE, 0, 0, -1,
295 	    line, strlen(line)+1) == -1)
296 		err = got_error_from_errno(
297 		    "imsg_compose GOT_IMSG_PATCH_LINE");
298 
299 	free(p);
300 	return err;
301 }
302 
303 static const struct got_error *
304 parse_hunk(FILE *fp, int *ok)
305 {
306 	static const struct got_error *err = NULL;
307 	struct got_imsg_patch_hunk hdr;
308 	char	*line = NULL, ch;
309 	size_t	 linesize = 0;
310 	ssize_t	 linelen;
311 	long	 leftold, leftnew;
312 
313 	linelen = getline(&line, &linesize, fp);
314 	if (linelen == -1) {
315 		*ok = 0;
316 		goto done;
317 	}
318 
319 	err = parse_hdr(line, ok, &hdr);
320 	if (err)
321 		goto done;
322 	if (!*ok) {
323 		if (fseek(fp, linelen * -1, SEEK_CUR) == -1)
324 			err = got_error_from_errno("fseek");
325 		goto done;
326 	}
327 
328 	leftold = hdr.oldlines;
329 	leftnew = hdr.newlines;
330 
331 	while (leftold > 0 || leftnew > 0) {
332 		linelen = getline(&line, &linesize, fp);
333 		if (linelen == -1) {
334 			if (ferror(fp)) {
335 				err = got_error_from_errno("getline");
336 				goto done;
337 			}
338 
339 			/* trailing newlines may be chopped */
340 			if (leftold < 3 && leftnew < 3) {
341 				*ok = 0;
342 				break;
343 			}
344 
345 			err = got_error(GOT_ERR_PATCH_TRUNCATED);
346 			goto done;
347 		}
348 
349 		/* usr.bin/patch allows '=' as context char */
350 		if (*line == '=')
351 			*line = ' ';
352 
353 		ch = *line;
354 		if (ch == '\t' || ch == '\n')
355 			ch = ' ';	/* the space got eaten */
356 
357 		switch (ch) {
358 		case '-':
359 			leftold--;
360 			break;
361 		case ' ':
362 			leftold--;
363 			leftnew--;
364 			break;
365 		case '+':
366 			leftnew--;
367 			break;
368 		default:
369 			err = got_error(GOT_ERR_PATCH_MALFORMED);
370 			goto done;
371 		}
372 
373 		if (leftold < 0 || leftnew < 0) {
374 			err = got_error(GOT_ERR_PATCH_MALFORMED);
375 			goto done;
376 		}
377 
378 		err = send_line(line);
379 		if (err)
380 			goto done;
381 	}
382 
383 done:
384 	free(line);
385 	return err;
386 }
387 
388 static const struct got_error *
389 read_patch(struct imsgbuf *ibuf, int fd)
390 {
391 	const struct got_error *err = NULL;
392 	FILE *fp;
393 	int ok, patch_found = 0;
394 
395 	if ((fp = fdopen(fd, "r")) == NULL) {
396 		err = got_error_from_errno("fdopen");
397 		close(fd);
398 		return err;
399 	}
400 
401 	while (!feof(fp)) {
402 		err = find_patch(fp);
403 		if (err)
404 			goto done;
405 
406 		patch_found = 1;
407 		for (;;) {
408 			err = parse_hunk(fp, &ok);
409 			if (err)
410 				goto done;
411 			if (!ok) {
412 				err = send_patch_done();
413 				if (err)
414 					goto done;
415 				break;
416 			}
417 		}
418 	}
419 
420 done:
421 	fclose(fp);
422 
423 	/* ignore trailing gibberish */
424 	if (err != NULL && err->code == GOT_ERR_NO_PATCH && patch_found)
425 		err = NULL;
426 
427 	return err;
428 }
429 
430 int
431 main(int argc, char **argv)
432 {
433 	const struct got_error *err = NULL;
434 	struct imsg imsg;
435 #if 0
436 	static int attached;
437 	while (!attached)
438 		sleep(1);
439 #endif
440 
441 	imsg_init(&ibuf, GOT_IMSG_FD_CHILD);
442 #ifndef PROFILE
443 	/* revoke access to most system calls */
444 	if (pledge("stdio recvfd", NULL) == -1) {
445 		err = got_error_from_errno("pledge");
446 		got_privsep_send_error(&ibuf, err);
447 		return 1;
448 	}
449 #endif
450 
451 	err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
452 	if (err)
453 		goto done;
454 	if (imsg.hdr.type != GOT_IMSG_PATCH_FILE || imsg.fd == -1) {
455 		err = got_error(GOT_ERR_PRIVSEP_MSG);
456 		goto done;
457 	}
458 
459 	err = read_patch(&ibuf, imsg.fd);
460 	if (err)
461 		goto done;
462 	if (imsg_compose(&ibuf, GOT_IMSG_PATCH_EOF, 0, 0, -1,
463 	    NULL, 0) == -1) {
464 		err = got_error_from_errno("imsg_compose GOT_IMSG_PATCH_EOF");
465 		goto done;
466 	}
467 	err = got_privsep_flush_imsg(&ibuf);
468 done:
469 	imsg_free(&imsg);
470 	if (err != NULL) {
471 		got_privsep_send_error(&ibuf, err);
472 		err = NULL;
473 	}
474 	if (close(GOT_IMSG_FD_CHILD) == -1 && err == NULL)
475 		err = got_error_from_errno("close");
476 	if (err && err->code != GOT_ERR_PRIVSEP_PIPE)
477 		fprintf(stderr, "%s: %s\n", getprogname(), err->msg);
478 	return err ? 1 : 0;
479 }