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Date:: Mon Dec 24 08:35:07 2018 UTC
Message:: eliminate got_object_open() round-trip when opening trees
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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 #include <sys/syslimits.h>
21 #include <sys/wait.h>
22 
23 #include <stdio.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <errno.h>
27 #include <stdint.h>
28 #include <poll.h>
29 #include <imsg.h>
30 #include <sha1.h>
31 #include <zlib.h>
32 #include <time.h>
33 
34 #include "got_object.h"
35 #include "got_error.h"
36 
37 #include "got_lib_sha1.h"
38 #include "got_lib_delta.h"
39 #include "got_lib_inflate.h"
40 #include "got_lib_object.h"
41 #include "got_lib_object_parse.h"
42 #include "got_lib_privsep.h"
43 #include "got_lib_pack.h"
44 
45 #ifndef MIN
46 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
47 #endif
48 
49 static const struct got_error *
50 poll_fd(int fd, int events, int timeout)
51 {
52 	struct pollfd pfd[1];
53 	int n;
54 
55 	pfd[0].fd = fd;
56 	pfd[0].events = events;
57 
58 	n = poll(pfd, 1, timeout);
59 	if (n == -1)
60 		return got_error_from_errno();
61 	if (n == 0)
62 		return got_error(GOT_ERR_TIMEOUT);
63 	if (pfd[0].revents & (POLLERR | POLLNVAL))
64 		return got_error_from_errno();
65 	if (pfd[0].revents & (events | POLLHUP))
66 		return NULL;
67 
68 	return got_error(GOT_ERR_INTERRUPT);
69 }
70 
71 static const struct got_error *
72 read_imsg(struct imsgbuf *ibuf)
73 {
74 	const struct got_error *err;
75 	size_t n;
76 
77 	err = poll_fd(ibuf->fd, POLLIN, INFTIM);
78 	if (err)
79 		return err;
80 
81 	n = imsg_read(ibuf);
82 	if (n == -1) {
83 		if (errno == EAGAIN) /* Could be a file-descriptor leak. */
84 			return got_error(GOT_ERR_PRIVSEP_NO_FD);
85 		return got_error(GOT_ERR_PRIVSEP_READ);
86 	}
87 	if (n == 0)
88 		return got_error(GOT_ERR_PRIVSEP_PIPE);
89 
90 	return NULL;
91 }
92 
93 const struct got_error *
94 got_privsep_wait_for_child(pid_t pid)
95 {
96 	int child_status;
97 
98 	waitpid(pid, &child_status, 0);
99 
100 	if (!WIFEXITED(child_status))
101 		return got_error(GOT_ERR_PRIVSEP_DIED);
102 
103 	if (WEXITSTATUS(child_status) != 0)
104 		return got_error(GOT_ERR_PRIVSEP_EXIT);
105 
106 	return NULL;
107 }
108 
109 static const struct got_error *
110 recv_imsg_error(struct imsg *imsg, size_t datalen)
111 {
112 	struct got_imsg_error *ierr;
113 
114 	if (datalen != sizeof(*ierr))
115 		return got_error(GOT_ERR_PRIVSEP_LEN);
116 
117 	ierr = imsg->data;
118 	if (ierr->code == GOT_ERR_ERRNO) {
119 		static struct got_error serr;
120 		serr.code = GOT_ERR_ERRNO;
121 		serr.msg = strerror(ierr->errno_code);
122 		return &serr;
123 	}
124 
125 	return got_error(ierr->code);
126 }
127 
128 const struct got_error *
129 got_privsep_recv_imsg(struct imsg *imsg, struct imsgbuf *ibuf,
130     size_t min_datalen)
131 {
132 	const struct got_error *err;
133 	ssize_t n;
134 
135 	n = imsg_get(ibuf, imsg);
136 	if (n == -1)
137 		return got_error_from_errno();
138 
139 	while (n == 0) {
140 		err = read_imsg(ibuf);
141 		if (err)
142 			return err;
143 		n = imsg_get(ibuf, imsg);
144 	}
145 
146 	if (imsg->hdr.len < IMSG_HEADER_SIZE + min_datalen)
147 		return got_error(GOT_ERR_PRIVSEP_LEN);
148 
149 	if (imsg->hdr.type == GOT_IMSG_ERROR) {
150 		size_t datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
151 		return recv_imsg_error(imsg, datalen);
152 	}
153 
154 	return NULL;
155 }
156 
157 /* Attempt to send an error in an imsg. Complain on stderr as a last resort. */
158 void
159 got_privsep_send_error(struct imsgbuf *ibuf, const struct got_error *err)
160 {
161 	const struct got_error *poll_err;
162 	struct got_imsg_error ierr;
163 	int ret;
164 
165 	ierr.code = err->code;
166 	if (err->code == GOT_ERR_ERRNO)
167 		ierr.errno_code = errno;
168 	else
169 		ierr.errno_code = 0;
170 	ret = imsg_compose(ibuf, GOT_IMSG_ERROR, 0, 0, -1, &ierr, sizeof(ierr));
171 	if (ret == -1) {
172 		fprintf(stderr, "%s: error %d \"%s\": imsg_compose: %s\n",
173 		    getprogname(), err->code, err->msg, strerror(errno));
174 		return;
175 	}
176 
177 	poll_err = poll_fd(ibuf->fd, POLLOUT, INFTIM);
178 	if (poll_err) {
179 		fprintf(stderr, "%s: error %d \"%s\": poll: %s\n",
180 		    getprogname(), err->code, err->msg, poll_err->msg);
181 		return;
182 	}
183 
184 	ret = imsg_flush(ibuf);
185 	if (ret == -1) {
186 		fprintf(stderr, "%s: error %d \"%s\": imsg_flush: %s\n",
187 		    getprogname(), err->code, err->msg, strerror(errno));
188 		return;
189 	}
190 }
191 
192 static const struct got_error *
193 flush_imsg(struct imsgbuf *ibuf)
194 {
195 	const struct got_error *err;
196 
197 	err = poll_fd(ibuf->fd, POLLOUT, INFTIM);
198 	if (err)
199 		return err;
200 
201 	if (imsg_flush(ibuf) == -1)
202 		return got_error_from_errno();
203 
204 	return NULL;
205 }
206 
207 const struct got_error *
208 got_privsep_send_stop(int fd)
209 {
210 	const struct got_error *err = NULL;
211 	struct imsgbuf ibuf;
212 
213 	imsg_init(&ibuf, fd);
214 
215 	if (imsg_compose(&ibuf, GOT_IMSG_STOP, 0, 0, -1, NULL, 0) == -1)
216 		return got_error_from_errno();
217 
218 	err = flush_imsg(&ibuf);
219 	imsg_clear(&ibuf);
220 	return err;
221 }
222 
223 const struct got_error *
224 got_privsep_send_obj_req(struct imsgbuf *ibuf, int fd, struct got_object *obj)
225 {
226 	struct got_imsg_object iobj, *iobjp = NULL;
227 	size_t iobj_size = 0;
228 	int imsg_code = GOT_IMSG_OBJECT_REQUEST;
229 
230 	if (obj) {
231 		switch (obj->type) {
232 		case GOT_OBJ_TYPE_TREE:
233 			imsg_code = GOT_IMSG_TREE_REQUEST;
234 			break;
235 		case GOT_OBJ_TYPE_COMMIT:
236 			abort(); /* should not get here */
237 			break;
238 		case GOT_OBJ_TYPE_BLOB:
239 			imsg_code = GOT_IMSG_BLOB_REQUEST;
240 			break;
241 		case GOT_OBJ_TYPE_TAG:
242 			imsg_code = GOT_IMSG_TAG_REQUEST;
243 			break;
244 		default:
245 			return got_error(GOT_ERR_OBJ_TYPE);
246 		}
247 
248 		memcpy(iobj.id, obj->id.sha1, sizeof(iobj.id));
249 		iobj.type = obj->type;
250 		iobj.flags = obj->flags;
251 		iobj.hdrlen = obj->hdrlen;
252 		iobj.size = obj->size;
253 		if (iobj.flags & GOT_OBJ_FLAG_PACKED) {
254 			iobj.pack_offset = obj->pack_offset;
255 			iobj.pack_idx = obj->pack_idx;
256 		}
257 
258 		iobjp = &iobj;
259 		iobj_size = sizeof(iobj);
260 	}
261 
262 	if (imsg_compose(ibuf, imsg_code, 0, 0, fd, iobjp, iobj_size) == -1)
263 		return got_error_from_errno();
264 
265 	return flush_imsg(ibuf);
266 }
267 
268 const struct got_error *
269 got_privsep_send_commit_req(struct imsgbuf *ibuf, int fd,
270     struct got_object_id *id, int pack_idx)
271 {
272 	struct got_imsg_packed_object iobj, *iobjp;
273 	size_t len;
274 
275 	if (id) { /* commit is packed */
276 		iobj.idx = pack_idx;
277 		memcpy(iobj.id, id->sha1, sizeof(iobj.id));
278 		iobjp = &iobj;
279 		len = sizeof(iobj);
280 	} else {
281 		iobjp = NULL;
282 		len = 0;
283 	}
284 
285 	if (imsg_compose(ibuf, GOT_IMSG_COMMIT_REQUEST, 0, 0, fd, iobjp, len)
286 	    == -1)
287 		return got_error_from_errno();
288 
289 	return flush_imsg(ibuf);
290 }
291 
292 const struct got_error *
293 got_privsep_send_tree_req(struct imsgbuf *ibuf, int fd,
294     struct got_object_id *id, int pack_idx)
295 {
296 	struct got_imsg_packed_object iobj, *iobjp;
297 	size_t len;
298 
299 	if (id) { /* tree is packed */
300 		iobj.idx = pack_idx;
301 		memcpy(iobj.id, id->sha1, sizeof(iobj.id));
302 		iobjp = &iobj;
303 		len = sizeof(iobj);
304 	} else {
305 		iobjp = NULL;
306 		len = 0;
307 	}
308 
309 	if (imsg_compose(ibuf, GOT_IMSG_TREE_REQUEST, 0, 0, fd, iobjp, len)
310 	    == -1)
311 		return got_error_from_errno();
312 
313 	return flush_imsg(ibuf);
314 }
315 
316 const struct got_error *
317 got_privsep_send_blob_req(struct imsgbuf *ibuf, int infd)
318 {
319 	if (imsg_compose(ibuf, GOT_IMSG_BLOB_REQUEST, 0, 0, infd, NULL, 0)
320 	    == -1)
321 		return got_error_from_errno();
322 
323 	return flush_imsg(ibuf);
324 }
325 
326 const struct got_error *
327 got_privsep_send_blob_outfd(struct imsgbuf *ibuf, int outfd)
328 {
329 	if (imsg_compose(ibuf, GOT_IMSG_BLOB_OUTFD, 0, 0, outfd, NULL, 0)
330 	    == -1)
331 		return got_error_from_errno();
332 
333 	return flush_imsg(ibuf);
334 }
335 
336 const struct got_error *
337 got_privsep_send_tmpfd(struct imsgbuf *ibuf, int fd)
338 {
339 	if (imsg_compose(ibuf, GOT_IMSG_TMPFD, 0, 0, fd, NULL, 0)
340 	    == -1)
341 		return got_error_from_errno();
342 
343 	return flush_imsg(ibuf);
344 }
345 
346 const struct got_error *
347 got_privsep_send_obj(struct imsgbuf *ibuf, struct got_object *obj)
348 {
349 	struct got_imsg_object iobj;
350 
351 	memcpy(iobj.id, obj->id.sha1, sizeof(iobj.id));
352 	iobj.type = obj->type;
353 	iobj.flags = obj->flags;
354 	iobj.hdrlen = obj->hdrlen;
355 	iobj.size = obj->size;
356 	if (iobj.flags & GOT_OBJ_FLAG_PACKED) {
357 		iobj.pack_offset = obj->pack_offset;
358 		iobj.pack_idx = obj->pack_idx;
359 	}
360 
361 	if (imsg_compose(ibuf, GOT_IMSG_OBJECT, 0, 0, -1, &iobj, sizeof(iobj))
362 	    == -1)
363 		return got_error_from_errno();
364 
365 	return flush_imsg(ibuf);
366 }
367 
368 const struct got_error *
369 got_privsep_get_imsg_obj(struct got_object **obj, struct imsg *imsg,
370     struct imsgbuf *ibuf)
371 {
372 	const struct got_error *err = NULL;
373 	struct got_imsg_object *iobj;
374 	size_t datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
375 
376 	if (datalen != sizeof(*iobj))
377 		return got_error(GOT_ERR_PRIVSEP_LEN);
378 	iobj = imsg->data;
379 
380 	*obj = calloc(1, sizeof(**obj));
381 	if (*obj == NULL)
382 		return got_error_from_errno();
383 
384 	memcpy((*obj)->id.sha1, iobj->id, SHA1_DIGEST_LENGTH);
385 	(*obj)->type = iobj->type;
386 	(*obj)->flags = iobj->flags;
387 	(*obj)->hdrlen = iobj->hdrlen;
388 	(*obj)->size = iobj->size;
389 	/* path_packfile is handled by caller */
390 	if (iobj->flags & GOT_OBJ_FLAG_PACKED) {
391 		(*obj)->pack_offset = iobj->pack_offset;
392 		(*obj)->pack_idx = iobj->pack_idx;
393 	}
394 
395 	return err;
396 }
397 
398 const struct got_error *
399 got_privsep_recv_obj(struct got_object **obj, struct imsgbuf *ibuf)
400 {
401 	const struct got_error *err = NULL;
402 	struct imsg imsg;
403 	size_t datalen;
404 	const size_t min_datalen =
405 	    MIN(sizeof(struct got_imsg_error), sizeof(struct got_imsg_object));
406 
407 	*obj = NULL;
408 
409 	err = got_privsep_recv_imsg(&imsg, ibuf, min_datalen);
410 	if (err)
411 		return err;
412 
413 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
414 
415 	switch (imsg.hdr.type) {
416 	case GOT_IMSG_OBJECT:
417 		err = got_privsep_get_imsg_obj(obj, &imsg, ibuf);
418 		break;
419 	default:
420 		err = got_error(GOT_ERR_PRIVSEP_MSG);
421 		break;
422 	}
423 
424 	imsg_free(&imsg);
425 
426 	return err;
427 }
428 
429 static const struct got_error *
430 send_commit_logmsg(struct imsgbuf *ibuf, struct got_commit_object *commit,
431     size_t logmsg_len)
432 {
433 	const struct got_error *err = NULL;
434 	size_t offset, remain;
435 
436 	offset = 0;
437 	remain = logmsg_len;
438 	while (remain > 0) {
439 		size_t n = MIN(MAX_IMSGSIZE - IMSG_HEADER_SIZE, remain);
440 
441 		if (imsg_compose(ibuf, GOT_IMSG_COMMIT_LOGMSG, 0, 0, -1,
442 		    commit->logmsg + offset, n) == -1) {
443 			err = got_error_from_errno();
444 			break;
445 		}
446 
447 		err = flush_imsg(ibuf);
448 		if (err)
449 			break;
450 
451 		offset += n;
452 		remain -= n;
453 	}
454 
455 	return err;
456 }
457 
458 const struct got_error *
459 got_privsep_send_commit(struct imsgbuf *ibuf, struct got_commit_object *commit)
460 {
461 	const struct got_error *err = NULL;
462 	struct got_imsg_commit_object *icommit;
463 	uint8_t *buf;
464 	size_t len, total;
465 	struct got_object_qid *qid;
466 	size_t author_len = strlen(commit->author);
467 	size_t committer_len = strlen(commit->committer);
468 	size_t logmsg_len = strlen(commit->logmsg);
469 
470 	total = sizeof(*icommit) + author_len + committer_len +
471 	    commit->nparents * SHA1_DIGEST_LENGTH;
472 
473 	buf = malloc(total);
474 	if (buf == NULL)
475 		return got_error_from_errno();
476 
477 	icommit = (struct got_imsg_commit_object *)buf;
478 	memcpy(icommit->tree_id, commit->tree_id->sha1, sizeof(icommit->tree_id));
479 	icommit->author_len = author_len;
480 	icommit->author_time = commit->author_time;
481 	icommit->author_gmtoff = commit->author_gmtoff;
482 	icommit->committer_len = committer_len;
483 	icommit->committer_time = commit->committer_time;
484 	icommit->committer_gmtoff = commit->committer_gmtoff;
485 	icommit->logmsg_len = logmsg_len;
486 	icommit->nparents = commit->nparents;
487 
488 	len = sizeof(*icommit);
489 	memcpy(buf + len, commit->author, author_len);
490 	len += author_len;
491 	memcpy(buf + len, commit->committer, committer_len);
492 	len += committer_len;
493 	SIMPLEQ_FOREACH(qid, &commit->parent_ids, entry) {
494 		memcpy(buf + len, qid->id, SHA1_DIGEST_LENGTH);
495 		len += SHA1_DIGEST_LENGTH;
496 	}
497 
498 	if (imsg_compose(ibuf, GOT_IMSG_COMMIT, 0, 0, -1, buf, len) == -1) {
499 		err = got_error_from_errno();
500 		goto done;
501 	}
502 
503 	if (logmsg_len == 0 ||
504 	    logmsg_len + len > MAX_IMSGSIZE - IMSG_HEADER_SIZE) {
505 		err = flush_imsg(ibuf);
506 		if (err)
507 			goto done;
508 	}
509 	err = send_commit_logmsg(ibuf, commit, logmsg_len);
510 done:
511 	free(buf);
512 	return err;
513 }
514 
515 const struct got_error *
516 got_privsep_recv_commit(struct got_commit_object **commit, struct imsgbuf *ibuf)
517 {
518 	const struct got_error *err = NULL;
519 	struct imsg imsg;
520 	struct got_imsg_commit_object *icommit;
521 	size_t len, datalen;
522 	int i;
523 	const size_t min_datalen =
524 	    MIN(sizeof(struct got_imsg_error),
525 	    sizeof(struct got_imsg_commit_object));
526 
527 	*commit = NULL;
528 
529 	err = got_privsep_recv_imsg(&imsg, ibuf, min_datalen);
530 	if (err)
531 		return err;
532 
533 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
534 	len = 0;
535 
536 	switch (imsg.hdr.type) {
537 	case GOT_IMSG_COMMIT:
538 		if (datalen < sizeof(*icommit)) {
539 			err = got_error(GOT_ERR_PRIVSEP_LEN);
540 			break;
541 		}
542 		icommit = imsg.data;
543 		if (datalen != sizeof(*icommit) + icommit->author_len +
544 		    icommit->committer_len +
545 		    icommit->nparents * SHA1_DIGEST_LENGTH) {
546 			err = got_error(GOT_ERR_PRIVSEP_LEN);
547 			break;
548 		}
549 		if (icommit->nparents < 0) {
550 			err = got_error(GOT_ERR_PRIVSEP_LEN);
551 			break;
552 		}
553 		len += sizeof(*icommit);
554 
555 		*commit = got_object_commit_alloc_partial();
556 		if (*commit == NULL) {
557 			err = got_error_from_errno();
558 			break;
559 		}
560 
561 		memcpy((*commit)->tree_id->sha1, icommit->tree_id,
562 		    SHA1_DIGEST_LENGTH);
563 		(*commit)->author_time = icommit->author_time;
564 		(*commit)->author_gmtoff = icommit->author_gmtoff;
565 		(*commit)->committer_time = icommit->committer_time;
566 		(*commit)->committer_gmtoff = icommit->committer_gmtoff;
567 
568 		if (icommit->author_len == 0) {
569 			(*commit)->author = strdup("");
570 			if ((*commit)->author == NULL) {
571 				err = got_error_from_errno();
572 				break;
573 			}
574 		} else {
575 			(*commit)->author = malloc(icommit->author_len + 1);
576 			if ((*commit)->author == NULL) {
577 				err = got_error_from_errno();
578 				break;
579 			}
580 			memcpy((*commit)->author, imsg.data + len,
581 			    icommit->author_len);
582 			(*commit)->author[icommit->author_len] = '\0';
583 		}
584 		len += icommit->author_len;
585 
586 		if (icommit->committer_len == 0) {
587 			(*commit)->committer = strdup("");
588 			if ((*commit)->committer == NULL) {
589 				err = got_error_from_errno();
590 				break;
591 			}
592 		} else {
593 			(*commit)->committer =
594 			    malloc(icommit->committer_len + 1);
595 			if ((*commit)->committer == NULL) {
596 				err = got_error_from_errno();
597 				break;
598 			}
599 			memcpy((*commit)->committer, imsg.data + len,
600 			    icommit->committer_len);
601 			(*commit)->committer[icommit->committer_len] = '\0';
602 		}
603 		len += icommit->committer_len;
604 
605 		if (icommit->logmsg_len == 0) {
606 			(*commit)->logmsg = strdup("");
607 			if ((*commit)->logmsg == NULL) {
608 				err = got_error_from_errno();
609 				break;
610 			}
611 		} else {
612 			size_t offset = 0, remain = icommit->logmsg_len;
613 
614 			(*commit)->logmsg = malloc(icommit->logmsg_len + 1);
615 			if ((*commit)->logmsg == NULL) {
616 				err = got_error_from_errno();
617 				break;
618 			}
619 			while (remain > 0) {
620 				struct imsg imsg_log;
621 				size_t n = MIN(MAX_IMSGSIZE - IMSG_HEADER_SIZE,
622 				    remain);
623 
624 				err = got_privsep_recv_imsg(&imsg_log, ibuf, n);
625 				if (err)
626 					return err;
627 
628 				if (imsg_log.hdr.type != GOT_IMSG_COMMIT_LOGMSG)
629 					return got_error(GOT_ERR_PRIVSEP_MSG);
630 
631 				memcpy((*commit)->logmsg + offset,
632 				    imsg_log.data, n);
633 				imsg_free(&imsg_log);
634 				offset += n;
635 				remain -= n;
636 			}
637 			(*commit)->logmsg[icommit->logmsg_len] = '\0';
638 		}
639 
640 		for (i = 0; i < icommit->nparents; i++) {
641 			struct got_object_qid *qid;
642 
643 			err = got_object_qid_alloc_partial(&qid);
644 			if (err)
645 				break;
646 			memcpy(qid->id, imsg.data + len +
647 			    i * SHA1_DIGEST_LENGTH, sizeof(*qid->id));
648 			SIMPLEQ_INSERT_TAIL(&(*commit)->parent_ids, qid, entry);
649 			(*commit)->nparents++;
650 		}
651 		break;
652 	default:
653 		err = got_error(GOT_ERR_PRIVSEP_MSG);
654 		break;
655 	}
656 
657 	imsg_free(&imsg);
658 
659 	return err;
660 }
661 
662 const struct got_error *
663 got_privsep_send_tree(struct imsgbuf *ibuf, struct got_tree_object *tree)
664 {
665 	const struct got_error *err = NULL;
666 	struct got_imsg_tree_object itree;
667 	struct got_tree_entry *te;
668 	size_t totlen;
669 	int nimsg; /* number of imsg queued in ibuf */
670 
671 	itree.nentries = tree->entries.nentries;
672 	if (imsg_compose(ibuf, GOT_IMSG_TREE, 0, 0, -1, &itree, sizeof(itree))
673 	    == -1)
674 		return got_error_from_errno();
675 
676 	totlen = sizeof(itree);
677 	nimsg = 1;
678 	SIMPLEQ_FOREACH(te, &tree->entries.head, entry) {
679 		struct got_imsg_tree_entry *ite;
680 		uint8_t *buf = NULL;
681 		size_t len = sizeof(*ite) + strlen(te->name);
682 
683 		if (len > MAX_IMSGSIZE)
684 			return got_error(GOT_ERR_NO_SPACE);
685 
686 		nimsg++;
687 		if (totlen + len >= MAX_IMSGSIZE - (IMSG_HEADER_SIZE * nimsg)) {
688 			err = flush_imsg(ibuf);
689 			if (err)
690 				return err;
691 			nimsg = 0;
692 		}
693 
694 		buf = malloc(len);
695 		if (buf == NULL)
696 			return got_error_from_errno();
697 
698 		ite = (struct got_imsg_tree_entry *)buf;
699 		memcpy(ite->id, te->id->sha1, sizeof(ite->id));
700 		ite->mode = te->mode;
701 		memcpy(buf + sizeof(*ite), te->name, strlen(te->name));
702 
703 		if (imsg_compose(ibuf, GOT_IMSG_TREE_ENTRY, 0, 0, -1,
704 		    buf, len) == -1)
705 			err = got_error_from_errno();
706 		free(buf);
707 		if (err)
708 			return err;
709 		totlen += len;
710 	}
711 
712 	return flush_imsg(ibuf);
713 }
714 
715 const struct got_error *
716 got_privsep_recv_tree(struct got_tree_object **tree, struct imsgbuf *ibuf)
717 {
718 	const struct got_error *err = NULL;
719 	const size_t min_datalen =
720 	    MIN(sizeof(struct got_imsg_error),
721 	    sizeof(struct got_imsg_tree_object));
722 	struct got_imsg_tree_object *itree;
723 	int nentries = 0;
724 
725 	*tree = NULL;
726 get_more:
727 	err = read_imsg(ibuf);
728 	if (err)
729 		goto done;
730 
731 	while (1) {
732 		struct imsg imsg;
733 		size_t n;
734 		size_t datalen;
735 		struct got_imsg_tree_entry *ite;
736 		struct got_tree_entry *te = NULL;
737 
738 		n = imsg_get(ibuf, &imsg);
739 		if (n == 0) {
740 			if (*tree && (*tree)->entries.nentries != nentries)
741 				goto get_more;
742 			break;
743 		}
744 
745 		if (imsg.hdr.len < IMSG_HEADER_SIZE + min_datalen)
746 			return got_error(GOT_ERR_PRIVSEP_LEN);
747 
748 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
749 
750 		switch (imsg.hdr.type) {
751 		case GOT_IMSG_ERROR:
752 			err = recv_imsg_error(&imsg, datalen);
753 			break;
754 		case GOT_IMSG_TREE:
755 			/* This message should only appear once. */
756 			if (*tree != NULL) {
757 				err = got_error(GOT_ERR_PRIVSEP_MSG);
758 				break;
759 			}
760 			if (datalen != sizeof(*itree)) {
761 				err = got_error(GOT_ERR_PRIVSEP_LEN);
762 				break;
763 			}
764 			itree = imsg.data;
765 			*tree = malloc(sizeof(**tree));
766 			if (*tree == NULL) {
767 				err = got_error_from_errno();
768 				break;
769 			}
770 			(*tree)->entries.nentries = itree->nentries;
771 			SIMPLEQ_INIT(&(*tree)->entries.head);
772 			(*tree)->refcnt = 0;
773 			break;
774 		case GOT_IMSG_TREE_ENTRY:
775 			/* This message should be preceeded by GOT_IMSG_TREE. */
776 			if (*tree == NULL) {
777 				err = got_error(GOT_ERR_PRIVSEP_MSG);
778 				break;
779 			}
780 			if (datalen < sizeof(*ite) || datalen > MAX_IMSGSIZE) {
781 				err = got_error(GOT_ERR_PRIVSEP_LEN);
782 				break;
783 			}
784 
785 			/* Remaining data contains the entry's name. */
786 			datalen -= sizeof(*ite);
787 			if (datalen == 0 || datalen > MAX_IMSGSIZE) {
788 				err = got_error(GOT_ERR_PRIVSEP_LEN);
789 				break;
790 			}
791 			ite = imsg.data;
792 
793 			te = got_alloc_tree_entry_partial();
794 			if (te == NULL) {
795 				err = got_error_from_errno();
796 				break;
797 			}
798 			te->name = malloc(datalen + 1);
799 			if (te->name == NULL) {
800 				free(te);
801 				err = got_error_from_errno();
802 				break;
803 			}
804 			memcpy(te->name, imsg.data + sizeof(*ite), datalen);
805 			te->name[datalen] = '\0';
806 
807 			memcpy(te->id->sha1, ite->id, SHA1_DIGEST_LENGTH);
808 			te->mode = ite->mode;
809 			SIMPLEQ_INSERT_TAIL(&(*tree)->entries.head, te, entry);
810 			nentries++;
811 			break;
812 		default:
813 			err = got_error(GOT_ERR_PRIVSEP_MSG);
814 			break;
815 		}
816 
817 		imsg_free(&imsg);
818 	}
819 done:
820 	if (*tree && (*tree)->entries.nentries != nentries) {
821 		if (err == NULL)
822 			err = got_error(GOT_ERR_PRIVSEP_LEN);
823 		got_object_tree_close(*tree);
824 		*tree = NULL;
825 	}
826 
827 	return err;
828 }
829 
830 const struct got_error *
831 got_privsep_send_blob(struct imsgbuf *ibuf, size_t size)
832 {
833 	struct got_imsg_blob iblob;
834 
835 	iblob.size = size;
836 	/* Data has already been written to file descriptor. */
837 
838 	if (imsg_compose(ibuf, GOT_IMSG_BLOB, 0, 0, -1, &iblob, sizeof(iblob))
839 	    == -1)
840 		return got_error_from_errno();
841 
842 	return flush_imsg(ibuf);
843 }
844 
845 const struct got_error *
846 got_privsep_recv_blob(size_t *size, struct imsgbuf *ibuf)
847 {
848 	const struct got_error *err = NULL;
849 	struct imsg imsg;
850 	struct got_imsg_blob *iblob;
851 	size_t datalen;
852 
853 	err = got_privsep_recv_imsg(&imsg, ibuf, 0);
854 	if (err)
855 		return err;
856 
857 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
858 
859 	switch (imsg.hdr.type) {
860 	case GOT_IMSG_BLOB:
861 		if (datalen != sizeof(*iblob)) {
862 			err = got_error(GOT_ERR_PRIVSEP_LEN);
863 			break;
864 		}
865 		iblob = imsg.data;
866 		*size = iblob->size;
867 		/* Data has been written to file descriptor. */
868 		break;
869 	default:
870 		err = got_error(GOT_ERR_PRIVSEP_MSG);
871 		break;
872 	}
873 
874 	imsg_free(&imsg);
875 
876 	return err;
877 }
878 
879 static const struct got_error *
880 send_tagmsg(struct imsgbuf *ibuf, struct got_tag_object *tag, size_t tagmsg_len)
881 {
882 	const struct got_error *err = NULL;
883 	size_t offset, remain;
884 
885 	offset = 0;
886 	remain = tagmsg_len;
887 	while (remain > 0) {
888 		size_t n = MIN(MAX_IMSGSIZE - IMSG_HEADER_SIZE, remain);
889 
890 		if (imsg_compose(ibuf, GOT_IMSG_TAG_TAGMSG, 0, 0, -1,
891 		    tag->tagmsg + offset, n) == -1) {
892 			err = got_error_from_errno();
893 			break;
894 		}
895 
896 		err = flush_imsg(ibuf);
897 		if (err)
898 			break;
899 
900 		offset += n;
901 		remain -= n;
902 	}
903 
904 	return err;
905 }
906 
907 const struct got_error *
908 got_privsep_send_tag(struct imsgbuf *ibuf, struct got_tag_object *tag)
909 {
910 	const struct got_error *err = NULL;
911 	struct got_imsg_tag_object *itag;
912 	uint8_t *buf;
913 	size_t len, total;
914 	size_t tag_len = strlen(tag->tag);
915 	size_t tagger_len = strlen(tag->tagger);
916 	size_t tagmsg_len = strlen(tag->tagmsg);
917 
918 	total = sizeof(*itag) + tag_len + tagger_len + tagmsg_len;
919 
920 	buf = malloc(total);
921 	if (buf == NULL)
922 		return got_error_from_errno();
923 
924 	itag = (struct got_imsg_tag_object *)buf;
925 	memcpy(itag->id, tag->id.sha1, sizeof(itag->id));
926 	itag->obj_type = tag->obj_type;
927 	itag->tag_len = tag_len;
928 	itag->tagger_len = tagger_len;
929 	itag->tagger_time = tag->tagger_time;
930 	itag->tagger_gmtoff = tag->tagger_gmtoff;
931 	itag->tagmsg_len = tagmsg_len;
932 
933 	len = sizeof(*itag);
934 	memcpy(buf + len, tag->tag, tag_len);
935 	len += tag_len;
936 	memcpy(buf + len, tag->tagger, tagger_len);
937 	len += tagger_len;
938 
939 	if (imsg_compose(ibuf, GOT_IMSG_TAG, 0, 0, -1, buf, len) == -1) {
940 		err = got_error_from_errno();
941 		goto done;
942 	}
943 
944 	if (tagmsg_len == 0 ||
945 	    tagmsg_len + len > MAX_IMSGSIZE - IMSG_HEADER_SIZE) {
946 		err = flush_imsg(ibuf);
947 		if (err)
948 			goto done;
949 	}
950 	err = send_tagmsg(ibuf, tag, tagmsg_len);
951 done:
952 	free(buf);
953 	return err;
954 }
955 
956 const struct got_error *
957 got_privsep_recv_tag(struct got_tag_object **tag, struct imsgbuf *ibuf)
958 {
959 	const struct got_error *err = NULL;
960 	struct imsg imsg;
961 	struct got_imsg_tag_object *itag;
962 	size_t len, datalen;
963 	const size_t min_datalen =
964 	    MIN(sizeof(struct got_imsg_error),
965 	    sizeof(struct got_imsg_tag_object));
966 
967 	*tag = NULL;
968 
969 	err = got_privsep_recv_imsg(&imsg, ibuf, min_datalen);
970 	if (err)
971 		return err;
972 
973 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
974 	len = 0;
975 
976 	switch (imsg.hdr.type) {
977 	case GOT_IMSG_TAG:
978 		if (datalen < sizeof(*itag)) {
979 			err = got_error(GOT_ERR_PRIVSEP_LEN);
980 			break;
981 		}
982 		itag = imsg.data;
983 		if (datalen != sizeof(*itag) + itag->tag_len +
984 		    itag->tagger_len) {
985 			err = got_error(GOT_ERR_PRIVSEP_LEN);
986 			break;
987 		}
988 		len += sizeof(*itag);
989 
990 		*tag = calloc(1, sizeof(**tag));
991 		if (*tag == NULL) {
992 			err = got_error_from_errno();
993 			break;
994 		}
995 
996 		memcpy((*tag)->id.sha1, itag->id, SHA1_DIGEST_LENGTH);
997 
998 		if (itag->tag_len == 0) {
999 			(*tag)->tag = strdup("");
1000 			if ((*tag)->tag == NULL) {
1001 				err = got_error_from_errno();
1002 				break;
1003 			}
1004 		} else {
1005 			(*tag)->tag = malloc(itag->tag_len + 1);
1006 			if ((*tag)->tag == NULL) {
1007 				err = got_error_from_errno();
1008 				break;
1009 			}
1010 			memcpy((*tag)->tag, imsg.data + len,
1011 			    itag->tag_len);
1012 			(*tag)->tag[itag->tag_len] = '\0';
1013 		}
1014 		len += itag->tag_len;
1015 
1016 		(*tag)->obj_type = itag->obj_type;
1017 		(*tag)->tagger_time = itag->tagger_time;
1018 		(*tag)->tagger_gmtoff = itag->tagger_gmtoff;
1019 
1020 		if (itag->tagger_len == 0) {
1021 			(*tag)->tagger = strdup("");
1022 			if ((*tag)->tagger == NULL) {
1023 				err = got_error_from_errno();
1024 				break;
1025 			}
1026 		} else {
1027 			(*tag)->tagger = malloc(itag->tagger_len + 1);
1028 			if ((*tag)->tagger == NULL) {
1029 				err = got_error_from_errno();
1030 				break;
1031 			}
1032 			memcpy((*tag)->tagger, imsg.data + len,
1033 			    itag->tagger_len);
1034 			(*tag)->tagger[itag->tagger_len] = '\0';
1035 		}
1036 		len += itag->tagger_len;
1037 
1038 		if (itag->tagmsg_len == 0) {
1039 			(*tag)->tagmsg = strdup("");
1040 			if ((*tag)->tagmsg == NULL) {
1041 				err = got_error_from_errno();
1042 				break;
1043 			}
1044 		} else {
1045 			size_t offset = 0, remain = itag->tagmsg_len;
1046 
1047 			(*tag)->tagmsg = malloc(itag->tagmsg_len + 1);
1048 			if ((*tag)->tagmsg == NULL) {
1049 				err = got_error_from_errno();
1050 				break;
1051 			}
1052 			while (remain > 0) {
1053 				struct imsg imsg_log;
1054 				size_t n = MIN(MAX_IMSGSIZE - IMSG_HEADER_SIZE,
1055 				    remain);
1056 
1057 				err = got_privsep_recv_imsg(&imsg_log, ibuf, n);
1058 				if (err)
1059 					return err;
1060 
1061 				if (imsg_log.hdr.type != GOT_IMSG_TAG_TAGMSG)
1062 					return got_error(GOT_ERR_PRIVSEP_MSG);
1063 
1064 				memcpy((*tag)->tagmsg + offset, imsg_log.data,
1065 				    n);
1066 				imsg_free(&imsg_log);
1067 				offset += n;
1068 				remain -= n;
1069 			}
1070 			(*tag)->tagmsg[itag->tagmsg_len] = '\0';
1071 		}
1072 
1073 		break;
1074 	default:
1075 		err = got_error(GOT_ERR_PRIVSEP_MSG);
1076 		break;
1077 	}
1078 
1079 	imsg_free(&imsg);
1080 
1081 	return err;
1082 }
1083 
1084 const struct got_error *
1085 got_privsep_init_pack_child(struct imsgbuf *ibuf, struct got_pack *pack,
1086     struct got_packidx *packidx)
1087 {
1088 	struct got_imsg_packidx ipackidx;
1089 	struct got_imsg_pack ipack;
1090 	int fd;
1091 
1092 	ipackidx.len = packidx->len;
1093 	fd = dup(packidx->fd);
1094 	if (fd == -1)
1095 		return got_error_from_errno();
1096 
1097 	if (imsg_compose(ibuf, GOT_IMSG_PACKIDX, 0, 0, fd, &ipackidx,
1098 	    sizeof(ipackidx)) == -1)
1099 		return got_error_from_errno();
1100 
1101 	if (strlcpy(ipack.path_packfile, pack->path_packfile,
1102 	    sizeof(ipack.path_packfile)) >= sizeof(ipack.path_packfile))
1103 		return got_error(GOT_ERR_NO_SPACE);
1104 	ipack.filesize = pack->filesize;
1105 
1106 	fd = dup(pack->fd);
1107 	if (fd == -1)
1108 		return got_error_from_errno();
1109 
1110 	if (imsg_compose(ibuf, GOT_IMSG_PACK, 0, 0, fd, &ipack, sizeof(ipack))
1111 	    == -1)
1112 		return got_error_from_errno();
1113 
1114 	return flush_imsg(ibuf);
1115 }
1116 
1117 const struct got_error *
1118 got_privsep_send_packed_obj_req(struct imsgbuf *ibuf, int idx,
1119     struct got_object_id *id)
1120 {
1121 	struct got_imsg_packed_object iobj;
1122 
1123 	iobj.idx = idx;
1124 	memcpy(iobj.id, id->sha1, sizeof(iobj.id));
1125 
1126 	if (imsg_compose(ibuf, GOT_IMSG_PACKED_OBJECT_REQUEST, 0, 0, -1,
1127 	    &iobj, sizeof(iobj)) == -1)
1128 		return got_error_from_errno();
1129 
1130 	return flush_imsg(ibuf);
1131 }