Got Mirror

Blob

Date:: Mon Mar 7 22:26:08 2022 UTC
Message:: add `got patch' command for applying unified diffs
Actions:: History | Blame | Raw File
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 			free(old);
175 			free(new);
176 
177 			if (err)
178 				break;
179 
180 			/* rewind to previous line */
181 			if (fseek(fp, linelen * -1, SEEK_CUR) == -1)
182 				err = got_error_from_errno("fseek");
183 			break;
184 		}
185 	}
186 
187 	free(line);
188 	if (ferror(fp) && err == NULL)
189 		err = got_error_from_errno("getline");
190 	if (feof(fp) && err == NULL)
191 		err = got_error(GOT_ERR_NO_PATCH);
192 	return err;
193 }
194 
195 static const struct got_error *
196 strtolnum(char **str, long *n)
197 {
198 	char		*p, c;
199 	const char	*errstr;
200 
201 	for (p = *str; isdigit((unsigned char)*p); ++p)
202 		/* nop */;
203 
204 	c = *p;
205 	*p = '\0';
206 
207 	*n = strtonum(*str, 0, LONG_MAX, &errstr);
208 	if (errstr != NULL)
209 		return got_error(GOT_ERR_PATCH_MALFORMED);
210 
211 	*p = c;
212 	*str = p;
213 	return NULL;
214 }
215 
216 static const struct got_error *
217 parse_hdr(char *s, int *ok, struct got_imsg_patch_hunk *hdr)
218 {
219 	static const struct got_error *err = NULL;
220 
221 	*ok = 1;
222 	if (strncmp(s, "@@ -", 4)) {
223 		*ok = 0;
224 		return NULL;
225 	}
226 
227 	s += 4;
228 	if (!*s)
229 		return NULL;
230 	err = strtolnum(&s, &hdr->oldfrom);
231 	if (err)
232 		return err;
233 	if (*s == ',') {
234 		s++;
235 		err = strtolnum(&s, &hdr->oldlines);
236 		if (err)
237 			return err;
238 	} else
239 		hdr->oldlines = 1;
240 
241 	if (*s == ' ')
242 		s++;
243 
244 	if (*s != '+' || !*++s)
245 		return got_error(GOT_ERR_PATCH_MALFORMED);
246 	err = strtolnum(&s, &hdr->newfrom);
247 	if (err)
248 		return err;
249 	if (*s == ',') {
250 		s++;
251 		err = strtolnum(&s, &hdr->newlines);
252 		if (err)
253 			return err;
254 	} else
255 		hdr->newlines = 1;
256 
257 	if (*s == ' ')
258 		s++;
259 
260 	if (*s != '@')
261 		return got_error(GOT_ERR_PATCH_MALFORMED);
262 
263 	if (hdr->oldfrom >= LONG_MAX - hdr->oldlines ||
264 	    hdr->newfrom >= LONG_MAX - hdr->newlines ||
265 	    /* not so sure about this one */
266 	    hdr->oldlines >= LONG_MAX - hdr->newlines - 1)
267 		return got_error(GOT_ERR_PATCH_MALFORMED);
268 
269 	if (hdr->oldlines == 0) {
270 		/* larry says to "do append rather than insert"; I don't
271 		 * quite get it, but i trust him.
272 		 */
273 		hdr->oldfrom++;
274 	}
275 
276 	if (imsg_compose(&ibuf, GOT_IMSG_PATCH_HUNK, 0, 0, -1,
277 	    hdr, sizeof(*hdr)) == -1)
278 		return got_error_from_errno(
279 		    "imsg_compose GOT_IMSG_PATCH_HUNK");
280 	return NULL;
281 }
282 
283 static const struct got_error *
284 send_line(const char *line)
285 {
286 	static const struct got_error *err = NULL;
287 	char *p = NULL;
288 
289 	if (*line != '+' && *line != '-' && *line != ' ') {
290 		if (asprintf(&p, " %s", line) == -1)
291 			return got_error_from_errno("asprintf");
292 		line = p;
293 	}
294 
295 	if (imsg_compose(&ibuf, GOT_IMSG_PATCH_LINE, 0, 0, -1,
296 	    line, strlen(line)+1) == -1)
297 		err = got_error_from_errno(
298 		    "imsg_compose GOT_IMSG_PATCH_LINE");
299 
300 	free(p);
301 	return err;
302 }
303 
304 static const struct got_error *
305 parse_hunk(FILE *fp, int *ok)
306 {
307 	static const struct got_error *err = NULL;
308 	struct got_imsg_patch_hunk hdr;
309 	char	*line = NULL, ch;
310 	size_t	 linesize = 0;
311 	ssize_t	 linelen;
312 	long	 leftold, leftnew;
313 
314 	linelen = getline(&line, &linesize, fp);
315 	if (linelen == -1) {
316 		*ok = 0;
317 		goto done;
318 	}
319 
320 	err = parse_hdr(line, ok, &hdr);
321 	if (err)
322 		goto done;
323 	if (!*ok) {
324 		if (fseek(fp, linelen * -1, SEEK_CUR) == -1)
325 			err = got_error_from_errno("fseek");
326 		goto done;
327 	}
328 
329 	leftold = hdr.oldlines;
330 	leftnew = hdr.newlines;
331 
332 	while (leftold > 0 || leftnew > 0) {
333 		linelen = getline(&line, &linesize, fp);
334 		if (linelen == -1) {
335 			if (ferror(fp)) {
336 				err = got_error_from_errno("getline");
337 				goto done;
338 			}
339 
340 			/* trailing newlines may be chopped */
341 			if (leftold < 3 && leftnew < 3) {
342 				*ok = 0;
343 				break;
344 			}
345 
346 			err = got_error(GOT_ERR_PATCH_TRUNCATED);
347 			goto done;
348 		}
349 
350 		/* usr.bin/patch allows '=' as context char */
351 		if (*line == '=')
352 			*line = ' ';
353 
354 		ch = *line;
355 		if (ch == '\t' || ch == '\n')
356 			ch = ' ';	/* the space got eaten */
357 
358 		switch (ch) {
359 		case '-':
360 			leftold--;
361 			break;
362 		case ' ':
363 			leftold--;
364 			leftnew--;
365 			break;
366 		case '+':
367 			leftnew--;
368 			break;
369 		default:
370 			err = got_error(GOT_ERR_PATCH_MALFORMED);
371 			goto done;
372 		}
373 
374 		if (leftold < 0 || leftnew < 0) {
375 			err = got_error(GOT_ERR_PATCH_MALFORMED);
376 			goto done;
377 		}
378 
379 		err = send_line(line);
380 		if (err)
381 			goto done;
382 	}
383 
384 done:
385 	free(line);
386 	return err;
387 }
388 
389 static const struct got_error *
390 read_patch(struct imsgbuf *ibuf, int fd)
391 {
392 	const struct got_error *err = NULL;
393 	FILE *fp;
394 	int ok, patch_found = 0;
395 
396 	if ((fp = fdopen(fd, "r")) == NULL) {
397 		err = got_error_from_errno("fdopen");
398 		close(fd);
399 		return err;
400 	}
401 
402 	while (!feof(fp)) {
403 		err = find_patch(fp);
404 		if (err)
405 			goto done;
406 
407 		patch_found = 1;
408 		for (;;) {
409 			err = parse_hunk(fp, &ok);
410 			if (err)
411 				goto done;
412 			if (!ok) {
413 				err = send_patch_done();
414 				if (err)
415 					goto done;
416 				break;
417 			}
418 		}
419 	}
420 
421 done:
422 	fclose(fp);
423 
424 	/* ignore trailing gibberish */
425 	if (err != NULL && err->code == GOT_ERR_NO_PATCH && patch_found)
426 		err = NULL;
427 
428 	return err;
429 }
430 
431 int
432 main(int argc, char **argv)
433 {
434 	const struct got_error *err = NULL;
435 	struct imsg imsg;
436 #if 0
437 	static int attached;
438 	while (!attached)
439 		sleep(1);
440 #endif
441 
442 	imsg_init(&ibuf, GOT_IMSG_FD_CHILD);
443 #ifndef PROFILE
444 	/* revoke access to most system calls */
445 	if (pledge("stdio recvfd", NULL) == -1) {
446 		err = got_error_from_errno("pledge");
447 		got_privsep_send_error(&ibuf, err);
448 		return 1;
449 	}
450 #endif
451 
452 	err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
453 	if (err)
454 		goto done;
455 	if (imsg.hdr.type != GOT_IMSG_PATCH_FILE || imsg.fd == -1) {
456 		err = got_error(GOT_ERR_PRIVSEP_MSG);
457 		goto done;
458 	}
459 
460 	err = read_patch(&ibuf, imsg.fd);
461 	if (err)
462 		goto done;
463 	if (imsg_compose(&ibuf, GOT_IMSG_PATCH_EOF, 0, 0, -1,
464 	    NULL, 0) == -1) {
465 		err = got_error_from_errno("imsg_compose GOT_IMSG_PATCH_EOF");
466 		goto done;
467 	}
468 	err = got_privsep_flush_imsg(&ibuf);
469 done:
470 	imsg_free(&imsg);
471 	if (err != NULL) {
472 		got_privsep_send_error(&ibuf, err);
473 		err = NULL;
474 	}
475 	if (close(GOT_IMSG_FD_CHILD) == -1 && err == NULL)
476 		err = got_error_from_errno("close");
477 	if (err && err->code != GOT_ERR_PRIVSEP_PIPE)
478 		fprintf(stderr, "%s: %s\n", getprogname(), err->msg);
479 	return err ? 1 : 0;
480 }