Game of Trees Repos

Blob

Date:: Thu Sep 6 15:33:13 2018 UTC
Message:: move object parsing code into a separate file
Actions:: History | Blame | Raw File
1 /*
2  * Copyright (c) 2018 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/types.h>
18 #include <sys/queue.h>
19 #include <sys/uio.h>
20 
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <string.h>
24 #include <errno.h>
25 #include <stdint.h>
26 #include <poll.h>
27 #include <imsg.h>
28 #include <sha1.h>
29 #include <zlib.h>
30 #include <time.h>
31 
32 #include "got_object.h"
33 #include "got_error.h"
34 
35 #include "got_lib_sha1.h"
36 #include "got_lib_delta.h"
37 #include "got_lib_inflate.h"
38 #include "got_lib_object.h"
39 #include "got_lib_object_parse.h"
40 #include "got_lib_privsep.h"
41 
42 #ifndef MIN
43 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
44 #endif
45 
46 static const struct got_error *
47 poll_fd(int fd, int events, int timeout)
48 {
49 	struct pollfd pfd[1];
50 	int n;
51 
52 	pfd[0].fd = fd;
53 	pfd[0].events = events;
54 
55 	n = poll(pfd, 1, timeout);
56 	if (n == -1)
57 		return got_error_from_errno();
58 	if (n == 0)
59 		return got_error(GOT_ERR_TIMEOUT);
60 	if (pfd[0].revents & (POLLERR | POLLNVAL))
61 		return got_error_from_errno();
62 	if (pfd[0].revents & (events | POLLHUP))
63 		return NULL;
64 
65 	return got_error(GOT_ERR_INTERRUPT);
66 }
67 
68 static const struct got_error *
69 read_imsg(struct imsgbuf *ibuf)
70 {
71 	const struct got_error *err;
72 	size_t n;
73 
74 	err = poll_fd(ibuf->fd, POLLIN, INFTIM);
75 	if (err)
76 		return err;
77 
78 	n = imsg_read(ibuf);
79 	if (n == -1) {
80 		if (errno == EAGAIN) /* Could be a file-descriptor leak. */
81 			return got_error(GOT_ERR_PRIVSEP_NO_FD);
82 		return got_error(GOT_ERR_PRIVSEP_READ);
83 	}
84 	if (n == 0)
85 		return got_error(GOT_ERR_PRIVSEP_PIPE);
86 
87 	return NULL;
88 }
89 
90 static const struct got_error *
91 recv_one_imsg(struct imsg *imsg, struct imsgbuf *ibuf, size_t min_datalen)
92 {
93 	const struct got_error *err;
94 	ssize_t n;
95 
96 	err = read_imsg(ibuf);
97 	if (err)
98 		return err;
99 
100 	n = imsg_get(ibuf, imsg);
101 	if (n == 0)
102 		return got_error(GOT_ERR_PRIVSEP_READ);
103 
104 	if (imsg->hdr.len < IMSG_HEADER_SIZE + min_datalen)
105 		return got_error(GOT_ERR_PRIVSEP_LEN);
106 
107 	return NULL;
108 }
109 
110 static const struct got_error *
111 recv_imsg_error(struct imsg *imsg, size_t datalen)
112 {
113 	struct got_imsg_error ierr;
114 
115 	if (datalen != sizeof(ierr))
116 		return got_error(GOT_ERR_PRIVSEP_LEN);
117 
118 	memcpy(&ierr, imsg->data, sizeof(ierr));
119 	if (ierr.code == GOT_ERR_ERRNO) {
120 		static struct got_error serr;
121 		serr.code = GOT_ERR_ERRNO;
122 		serr.msg = strerror(ierr.errno_code);
123 		return &serr;
124 	}
125 
126 	return got_error(ierr.code);
127 }
128 
129 /* Attempt to send an error in an imsg. Complain on stderr as a last resort. */
130 void
131 got_privsep_send_error(struct imsgbuf *ibuf, const struct got_error *err)
132 {
133 	const struct got_error *poll_err;
134 	struct got_imsg_error ierr;
135 	int ret;
136 
137 	ierr.code = err->code;
138 	if (err->code == GOT_ERR_ERRNO)
139 		ierr.errno_code = errno;
140 	else
141 		ierr.errno_code = 0;
142 	ret = imsg_compose(ibuf, GOT_IMSG_ERROR, 0, 0, -1, &ierr, sizeof(ierr));
143 	if (ret != -1) {
144 		fprintf(stderr, "%s: error %d \"%s\": imsg_compose: %s\n",
145 		    getprogname(), err->code, err->msg, strerror(errno));
146 		return;
147 	}
148 
149 	poll_err = poll_fd(ibuf->fd, POLLOUT, INFTIM);
150 	if (poll_err) {
151 		fprintf(stderr, "%s: error %d \"%s\": poll: %s\n",
152 		    getprogname(), err->code, err->msg, poll_err->msg);
153 		return;
154 	}
155 
156 	ret = imsg_flush(ibuf);
157 	if (ret == -1) {
158 		fprintf(stderr, "%s: error %d \"%s\": imsg_flush: %s\n",
159 		    getprogname(), err->code, err->msg, strerror(errno));
160 		return;
161 	}
162 }
163 
164 static const struct got_error *
165 flush_imsg(struct imsgbuf *ibuf)
166 {
167 	const struct got_error *err;
168 
169 	err = poll_fd(ibuf->fd, POLLOUT, INFTIM);
170 	if (err)
171 		return err;
172 
173 	if (imsg_flush(ibuf) == -1)
174 		return got_error_from_errno();
175 
176 	return NULL;
177 }
178 
179 const struct got_error *
180 got_privsep_send_obj(struct imsgbuf *ibuf, struct got_object *obj, int ndeltas)
181 {
182 	struct got_imsg_object iobj;
183 
184 	iobj.type = obj->type;
185 	iobj.flags = obj->flags;
186 	iobj.hdrlen = obj->hdrlen;
187 	iobj.size = obj->size;
188 	iobj.ndeltas = ndeltas;
189 
190 	if (ndeltas > 0) {
191 		/* TODO: Handle deltas */
192 	}
193 
194 	if (imsg_compose(ibuf, GOT_IMSG_OBJECT, 0, 0, -1, &iobj, sizeof(iobj))
195 	    == -1)
196 		return got_error_from_errno();
197 
198 	return flush_imsg(ibuf);
199 }
200 
201 const struct got_error *
202 got_privsep_recv_obj(struct got_object **obj, struct imsgbuf *ibuf)
203 {
204 	const struct got_error *err = NULL;
205 	struct imsg imsg;
206 	struct got_imsg_object iobj;
207 	size_t datalen;
208 	int i;
209 	const size_t min_datalen =
210 	    MIN(sizeof(struct got_imsg_error), sizeof(struct got_imsg_object));
211 
212 	*obj = NULL;
213 
214 	err = recv_one_imsg(&imsg, ibuf, min_datalen);
215 	if (err)
216 		return err;
217 
218 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
219 
220 	switch (imsg.hdr.type) {
221 	case GOT_IMSG_ERROR:
222 		err = recv_imsg_error(&imsg, datalen);
223 		break;
224 	case GOT_IMSG_OBJECT:
225 		if (datalen != sizeof(iobj)) {
226 			err = got_error(GOT_ERR_PRIVSEP_LEN);
227 			break;
228 		}
229 
230 		memcpy(&iobj, imsg.data, sizeof(iobj));
231 		if (iobj.ndeltas < 0 ||
232 		    iobj.ndeltas > GOT_DELTA_CHAIN_RECURSION_MAX) {
233 			err = got_error(GOT_ERR_PRIVSEP_LEN);
234 			break;
235 		}
236 
237 		*obj = calloc(1, sizeof(**obj));
238 		if (*obj == NULL) {
239 			err = got_error_from_errno();
240 			break;
241 		}
242 
243 		(*obj)->type = iobj.type;
244 		(*obj)->hdrlen = iobj.hdrlen;
245 		(*obj)->size = iobj.size;
246 		for (i = 0; i < iobj.ndeltas; i++) {
247 			/* TODO: Handle deltas */
248 		}
249 		break;
250 	default:
251 		err = got_error(GOT_ERR_PRIVSEP_MSG);
252 		break;
253 	}
254 
255 	imsg_free(&imsg);
256 
257 	return err;
258 }
259 
260 const struct got_error *
261 got_privsep_send_commit(struct imsgbuf *ibuf, struct got_commit_object *commit)
262 {
263 	const struct got_error *err = NULL;
264 	struct got_imsg_commit_object icommit;
265 	uint8_t *buf;
266 	size_t len, total;
267 	struct got_object_qid *qid;
268 
269 	memcpy(icommit.tree_id, commit->tree_id->sha1, sizeof(icommit.tree_id));
270 	icommit.author_len = strlen(commit->author);
271 	memcpy(&icommit.tm_author, &commit->tm_author,
272 	    sizeof(icommit.tm_author));
273 	icommit.committer_len = strlen(commit->committer);
274 	memcpy(&icommit.tm_committer, &commit->tm_committer,
275 	    sizeof(icommit.tm_committer));
276 	icommit.logmsg_len = strlen(commit->logmsg);
277 	icommit.nparents = commit->nparents;
278 
279 	total = sizeof(icommit) + icommit.author_len +
280 	    icommit.committer_len + icommit.logmsg_len +
281 	    icommit.nparents * SHA1_DIGEST_LENGTH;
282 	/* XXX TODO support very large log messages properly */
283 	if (total > MAX_IMSGSIZE)
284 		return got_error(GOT_ERR_NO_SPACE);
285 
286 	buf = malloc(total);
287 	if (buf == NULL)
288 		return got_error_from_errno();
289 
290 	len = 0;
291 	memcpy(buf + len, &icommit, sizeof(icommit));
292 	len += sizeof(icommit);
293 	memcpy(buf + len, commit->author, icommit.author_len);
294 	len += icommit.author_len;
295 	memcpy(buf + len, commit->committer, icommit.committer_len);
296 	len += icommit.committer_len;
297 	memcpy(buf + len, commit->logmsg, icommit.logmsg_len);
298 	len += icommit.logmsg_len;
299 	SIMPLEQ_FOREACH(qid, &commit->parent_ids, entry) {
300 		memcpy(buf + len, qid->id, SHA1_DIGEST_LENGTH);
301 		len += SHA1_DIGEST_LENGTH;
302 	}
303 
304 	if (imsg_compose(ibuf, GOT_IMSG_COMMIT, 0, 0, -1, buf, len) == -1) {
305 		err = got_error_from_errno();
306 		goto done;
307 	}
308 
309 	err = flush_imsg(ibuf);
310 done:
311 	free(buf);
312 	return err;
313 }
314 const struct got_error *
315 got_privsep_recv_commit(struct got_commit_object **commit, struct imsgbuf *ibuf)
316 {
317 	const struct got_error *err = NULL;
318 	struct imsg imsg;
319 	struct got_imsg_commit_object icommit;
320 	size_t len, datalen;
321 	int i;
322 	const size_t min_datalen =
323 	    MIN(sizeof(struct got_imsg_error),
324 	    sizeof(struct got_imsg_commit_object));
325 	uint8_t *data;
326 
327 	*commit = NULL;
328 
329 	err = recv_one_imsg(&imsg, ibuf, min_datalen);
330 	if (err)
331 		return err;
332 
333 	data = imsg.data;
334 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
335 	len = 0;
336 
337 	switch (imsg.hdr.type) {
338 	case GOT_IMSG_ERROR:
339 		err = recv_imsg_error(&imsg, datalen);
340 		break;
341 	case GOT_IMSG_COMMIT:
342 		if (datalen < sizeof(icommit)) {
343 			err = got_error(GOT_ERR_PRIVSEP_LEN);
344 			break;
345 		}
346 
347 		memcpy(&icommit, data, sizeof(icommit));
348 		if (datalen != sizeof(icommit) + icommit.author_len +
349 		    icommit.committer_len + icommit.logmsg_len +
350 		    icommit.nparents * SHA1_DIGEST_LENGTH) {
351 			err = got_error(GOT_ERR_PRIVSEP_LEN);
352 			break;
353 		}
354 		if (icommit.nparents < 0) {
355 			err = got_error(GOT_ERR_PRIVSEP_LEN);
356 			break;
357 		}
358 		len += sizeof(icommit);
359 
360 		*commit = got_object_commit_alloc_partial();
361 		if (*commit == NULL) {
362 			err = got_error_from_errno();
363 			break;
364 		}
365 
366 		memcpy((*commit)->tree_id->sha1, icommit.tree_id,
367 		    SHA1_DIGEST_LENGTH);
368 		memcpy(&(*commit)->tm_author, &icommit.tm_author,
369 		    sizeof((*commit)->tm_author));
370 		memcpy(&(*commit)->tm_committer, &icommit.tm_committer,
371 		    sizeof((*commit)->tm_committer));
372 
373 		if (icommit.author_len == 0) {
374 			(*commit)->author = strdup("");
375 			if ((*commit)->author == NULL) {
376 				err = got_error_from_errno();
377 				break;
378 			}
379 		} else {
380 			(*commit)->author = malloc(icommit.author_len + 1);
381 			if ((*commit)->author == NULL) {
382 				err = got_error_from_errno();
383 				break;
384 			}
385 			memcpy((*commit)->author, data + len,
386 			    icommit.author_len);
387 			(*commit)->author[icommit.author_len] = '\0';
388 		}
389 		len += icommit.author_len;
390 
391 		if (icommit.committer_len == 0) {
392 			(*commit)->committer = strdup("");
393 			if ((*commit)->committer == NULL) {
394 				err = got_error_from_errno();
395 				break;
396 			}
397 		} else {
398 			(*commit)->committer =
399 			    malloc(icommit.committer_len + 1);
400 			if ((*commit)->committer == NULL) {
401 				err = got_error_from_errno();
402 				break;
403 			}
404 			memcpy((*commit)->committer, data + len,
405 			    icommit.committer_len);
406 			(*commit)->committer[icommit.committer_len] = '\0';
407 		}
408 		len += icommit.committer_len;
409 
410 		if (icommit.logmsg_len == 0) {
411 			(*commit)->logmsg = strdup("");
412 			if ((*commit)->logmsg == NULL) {
413 				err = got_error_from_errno();
414 				break;
415 			}
416 		} else {
417 			(*commit)->logmsg = malloc(icommit.logmsg_len + 1);
418 			if ((*commit)->logmsg == NULL) {
419 				err = got_error_from_errno();
420 				break;
421 			}
422 			memcpy((*commit)->logmsg, data + len,
423 			    icommit.logmsg_len);
424 			(*commit)->logmsg[icommit.logmsg_len] = '\0';
425 		}
426 		len += icommit.logmsg_len;
427 
428 		for (i = 0; i < icommit.nparents; i++) {
429 			struct got_object_qid *qid;
430 
431 			qid = calloc(1, sizeof(*qid));
432 			if (qid == NULL) {
433 				err = got_error_from_errno();
434 				break;
435 			}
436 			qid->id = calloc(1, sizeof(*qid->id));
437 			if (qid->id == NULL) {
438 				err = got_error_from_errno();
439 				free(qid);
440 				break;
441 			}
442 
443 			memcpy(qid->id, data + len + i * SHA1_DIGEST_LENGTH,
444 			    sizeof(*qid->id));
445 			SIMPLEQ_INSERT_TAIL(&(*commit)->parent_ids, qid, entry);
446 			(*commit)->nparents++;
447 		}
448 		break;
449 	default:
450 		err = got_error(GOT_ERR_PRIVSEP_MSG);
451 		break;
452 	}
453 
454 	imsg_free(&imsg);
455 
456 	return err;
457 }
458 
459 const struct got_error *
460 got_privsep_send_tree(struct imsgbuf *ibuf, struct got_tree_object *tree)
461 {
462 	const struct got_error *err = NULL;
463 	struct got_imsg_tree_object itree;
464 	struct got_tree_entry *te;
465 
466 	itree.nentries = tree->entries.nentries;
467 	if (imsg_compose(ibuf, GOT_IMSG_TREE, 0, 0, -1, &itree, sizeof(itree))
468 	    == -1)
469 		return got_error_from_errno();
470 
471 	err = flush_imsg(ibuf);
472 	if (err)
473 		return err;
474 
475 	SIMPLEQ_FOREACH(te, &tree->entries.head, entry) {
476 		struct got_imsg_tree_entry ite;
477 		uint8_t *buf = NULL;
478 		size_t len = sizeof(ite) + strlen(te->name);
479 
480 		if (len > MAX_IMSGSIZE)
481 			return got_error(GOT_ERR_NO_SPACE);
482 
483 		buf = malloc(len);
484 		if (buf == NULL)
485 			return got_error_from_errno();
486 
487 		memcpy(ite.id, te->id->sha1, sizeof(ite.id));
488 		ite.mode = te->mode;
489 		memcpy(buf, &ite, sizeof(ite));
490 		memcpy(buf + sizeof(ite), te->name, strlen(te->name));
491 
492 		if (imsg_compose(ibuf, GOT_IMSG_TREE_ENTRY, 0, 0, -1,
493 		    buf, len) == -1)
494 			err = got_error_from_errno();
495 		free(buf);
496 		if (err)
497 			return err;
498 
499 		err = flush_imsg(ibuf);
500 		if (err)
501 			return err;
502 	}
503 
504 	return NULL;
505 }
506 
507 const struct got_error *
508 got_privsep_recv_tree(struct got_tree_object **tree, struct imsgbuf *ibuf)
509 {
510 	const struct got_error *err = NULL;
511 	const size_t min_datalen =
512 	    MIN(sizeof(struct got_imsg_error),
513 	    sizeof(struct got_imsg_tree_object));
514 	struct got_imsg_tree_object itree = { 0 };
515 	int nentries = 0;
516 
517 	*tree = NULL;
518 get_more:
519 	err = read_imsg(ibuf);
520 	if (err)
521 		goto done;
522 
523 	while (1) {
524 		struct imsg imsg;
525 		size_t n;
526 		size_t datalen;
527 		struct got_imsg_tree_entry ite;
528 		struct got_tree_entry *te = NULL;
529 
530 		n = imsg_get(ibuf, &imsg);
531 		if (n == 0) {
532 			if (*tree && (*tree)->entries.nentries != nentries)
533 				goto get_more;
534 			break;
535 		}
536 
537 		if (imsg.hdr.len < IMSG_HEADER_SIZE + min_datalen)
538 			return got_error(GOT_ERR_PRIVSEP_LEN);
539 
540 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
541 
542 		switch (imsg.hdr.type) {
543 		case GOT_IMSG_ERROR:
544 			err = recv_imsg_error(&imsg, datalen);
545 			break;
546 		case GOT_IMSG_TREE:
547 			/* This message should only appear once. */
548 			if (*tree != NULL) {
549 				err = got_error(GOT_ERR_PRIVSEP_MSG);
550 				break;
551 			}
552 			if (datalen != sizeof(itree)) {
553 				err = got_error(GOT_ERR_PRIVSEP_LEN);
554 				break;
555 			}
556 			memcpy(&itree, imsg.data, sizeof(itree));
557 			*tree = calloc(1, sizeof(**tree));
558 			if (*tree == NULL) {
559 				err = got_error_from_errno();
560 				break;
561 			}
562 			(*tree)->entries.nentries = itree.nentries;
563 			SIMPLEQ_INIT(&(*tree)->entries.head);
564 			break;
565 		case GOT_IMSG_TREE_ENTRY:
566 			/* This message should be preceeded by GOT_IMSG_TREE. */
567 			if (*tree == NULL) {
568 				err = got_error(GOT_ERR_PRIVSEP_MSG);
569 				break;
570 			}
571 			if (datalen < sizeof(ite) || datalen > MAX_IMSGSIZE) {
572 				err = got_error(GOT_ERR_PRIVSEP_LEN);
573 				break;
574 			}
575 
576 			/* Remaining data contains the entry's name. */
577 			datalen -= sizeof(ite);
578 			memcpy(&ite, imsg.data, sizeof(ite));
579 			if (datalen == 0 || datalen > MAX_IMSGSIZE) {
580 				err = got_error(GOT_ERR_PRIVSEP_LEN);
581 				break;
582 			}
583 
584 			te = got_alloc_tree_entry_partial();
585 			if (te == NULL) {
586 				err = got_error_from_errno();
587 				break;
588 			}
589 			te->name = malloc(datalen + 1);
590 			if (te->name == NULL) {
591 				free(te);
592 				err = got_error_from_errno();
593 				break;
594 			}
595 			memcpy(te->name, imsg.data + sizeof(ite), datalen);
596 			te->name[datalen] = '\0';
597 
598 			memcpy(te->id->sha1, ite.id, SHA1_DIGEST_LENGTH);
599 			te->mode = ite.mode;
600 			SIMPLEQ_INSERT_TAIL(&(*tree)->entries.head, te, entry);
601 			nentries++;
602 			break;
603 		default:
604 			err = got_error(GOT_ERR_PRIVSEP_MSG);
605 			break;
606 		}
607 
608 		imsg_free(&imsg);
609 	}
610 done:
611 	if (*tree && (*tree)->entries.nentries != nentries) {
612 		if (err == NULL)
613 			err = got_error(GOT_ERR_PRIVSEP_LEN);
614 		got_object_tree_close(*tree);
615 		*tree = NULL;
616 	}
617 
618 	return err;
619 }
620 
621 const struct got_error *
622 got_privsep_send_blob(struct imsgbuf *ibuf, size_t size)
623 {
624 	struct got_imsg_blob iblob;
625 
626 	iblob.size = size;
627 	/* Data has already been written to file descriptor. */
628 
629 	if (imsg_compose(ibuf, GOT_IMSG_BLOB, 0, 0, -1, &iblob, sizeof(iblob))
630 	    == -1)
631 		return got_error_from_errno();
632 
633 	return flush_imsg(ibuf);
634 }
635 
636 const struct got_error *
637 got_privsep_recv_blob(size_t *size, struct imsgbuf *ibuf)
638 {
639 	const struct got_error *err = NULL;
640 	struct imsg imsg;
641 	struct got_imsg_blob iblob;
642 	size_t datalen;
643 
644 	err = recv_one_imsg(&imsg, ibuf, 0);
645 	if (err)
646 		return err;
647 
648 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
649 
650 	switch (imsg.hdr.type) {
651 	case GOT_IMSG_ERROR:
652 		err = recv_imsg_error(&imsg, datalen);
653 		break;
654 	case GOT_IMSG_BLOB:
655 		if (datalen != sizeof(iblob))
656 			err = got_error(GOT_ERR_PRIVSEP_LEN);
657 		memcpy(&iblob, imsg.data, sizeof(iblob));
658 		*size = iblob.size;
659 		/* Data has been written to file descriptor. */
660 		break;
661 	default:
662 		err = got_error(GOT_ERR_PRIVSEP_MSG);
663 		break;
664 	}
665 
666 	imsg_free(&imsg);
667 
668 	return err;
669 }