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Date:: Mon Nov 5 17:25:15 2018 UTC
Message:: improve handling of struct got_object_qid allocations
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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 const struct got_error *
110 got_privsep_recv_imsg(struct imsg *imsg, struct imsgbuf *ibuf, size_t min_datalen)
111 {
112 	const struct got_error *err;
113 	ssize_t n;
114 
115 	n = imsg_get(ibuf, imsg);
116 	if (n == -1)
117 		return got_error_from_errno();
118 
119 	while (n == 0) {
120 		err = read_imsg(ibuf);
121 		if (err)
122 			return err;
123 		n = imsg_get(ibuf, imsg);
124 	}
125 
126 	if (imsg->hdr.len < IMSG_HEADER_SIZE + min_datalen)
127 		return got_error(GOT_ERR_PRIVSEP_LEN);
128 
129 	return NULL;
130 }
131 
132 static const struct got_error *
133 recv_imsg_error(struct imsg *imsg, size_t datalen)
134 {
135 	struct got_imsg_error ierr;
136 
137 	if (datalen != sizeof(ierr))
138 		return got_error(GOT_ERR_PRIVSEP_LEN);
139 
140 	memcpy(&ierr, imsg->data, sizeof(ierr));
141 	if (ierr.code == GOT_ERR_ERRNO) {
142 		static struct got_error serr;
143 		serr.code = GOT_ERR_ERRNO;
144 		serr.msg = strerror(ierr.errno_code);
145 		return &serr;
146 	}
147 
148 	return got_error(ierr.code);
149 }
150 
151 /* Attempt to send an error in an imsg. Complain on stderr as a last resort. */
152 void
153 got_privsep_send_error(struct imsgbuf *ibuf, const struct got_error *err)
154 {
155 	const struct got_error *poll_err;
156 	struct got_imsg_error ierr;
157 	int ret;
158 
159 	ierr.code = err->code;
160 	if (err->code == GOT_ERR_ERRNO)
161 		ierr.errno_code = errno;
162 	else
163 		ierr.errno_code = 0;
164 	ret = imsg_compose(ibuf, GOT_IMSG_ERROR, 0, 0, -1, &ierr, sizeof(ierr));
165 	if (ret != -1) {
166 		fprintf(stderr, "%s: error %d \"%s\": imsg_compose: %s\n",
167 		    getprogname(), err->code, err->msg, strerror(errno));
168 		return;
169 	}
170 
171 	poll_err = poll_fd(ibuf->fd, POLLOUT, INFTIM);
172 	if (poll_err) {
173 		fprintf(stderr, "%s: error %d \"%s\": poll: %s\n",
174 		    getprogname(), err->code, err->msg, poll_err->msg);
175 		return;
176 	}
177 
178 	ret = imsg_flush(ibuf);
179 	if (ret == -1) {
180 		fprintf(stderr, "%s: error %d \"%s\": imsg_flush: %s\n",
181 		    getprogname(), err->code, err->msg, strerror(errno));
182 		return;
183 	}
184 }
185 
186 static const struct got_error *
187 flush_imsg(struct imsgbuf *ibuf)
188 {
189 	const struct got_error *err;
190 
191 	err = poll_fd(ibuf->fd, POLLOUT, INFTIM);
192 	if (err)
193 		return err;
194 
195 	if (imsg_flush(ibuf) == -1)
196 		return got_error_from_errno();
197 
198 	return NULL;
199 }
200 
201 const struct got_error *
202 got_privsep_send_stop(int fd)
203 {
204 	const struct got_error *err = NULL;
205 	struct imsgbuf ibuf;
206 
207 	imsg_init(&ibuf, fd);
208 
209 	if (imsg_compose(&ibuf, GOT_IMSG_STOP, 0, 0, -1, NULL, 0) == -1)
210 		return got_error_from_errno();
211 
212 	err = flush_imsg(&ibuf);
213 	imsg_clear(&ibuf);
214 	return err;
215 }
216 
217 const struct got_error *
218 got_privsep_send_obj_req(struct imsgbuf *ibuf, int fd, struct got_object *obj)
219 {
220 	struct got_imsg_object iobj, *iobjp = NULL;
221 	size_t iobj_size = 0;
222 	int imsg_code = GOT_IMSG_OBJECT_REQUEST;
223 
224 	if (obj) {
225 		switch (obj->type) {
226 		case GOT_OBJ_TYPE_TREE:
227 			imsg_code = GOT_IMSG_TREE_REQUEST;
228 			break;
229 		case GOT_OBJ_TYPE_COMMIT:
230 			imsg_code = GOT_IMSG_COMMIT_REQUEST;
231 			break;
232 		case GOT_OBJ_TYPE_BLOB:
233 			imsg_code = GOT_IMSG_BLOB_REQUEST;
234 			break;
235 		default:
236 			return got_error(GOT_ERR_OBJ_TYPE);
237 		}
238 
239 		memcpy(iobj.id, obj->id.sha1, sizeof(iobj.id));
240 		iobj.type = obj->type;
241 		iobj.flags = obj->flags;
242 		iobj.hdrlen = obj->hdrlen;
243 		iobj.size = obj->size;
244 		if (iobj.flags & GOT_OBJ_FLAG_PACKED) {
245 			iobj.pack_offset = obj->pack_offset;
246 			iobj.pack_idx = obj->pack_idx;
247 		}
248 
249 		iobjp = &iobj;
250 		iobj_size = sizeof(iobj);
251 	}
252 
253 	if (imsg_compose(ibuf, imsg_code, 0, 0, fd, iobjp, iobj_size) == -1)
254 		return got_error_from_errno();
255 
256 	return flush_imsg(ibuf);
257 }
258 
259 const struct got_error *
260 got_privsep_send_blob_req(struct imsgbuf *ibuf, int infd)
261 {
262 	if (imsg_compose(ibuf, GOT_IMSG_BLOB_REQUEST, 0, 0, infd, NULL, 0)
263 	    == -1)
264 		return got_error_from_errno();
265 
266 	return flush_imsg(ibuf);
267 }
268 
269 const struct got_error *
270 got_privsep_send_blob_outfd(struct imsgbuf *ibuf, int outfd)
271 {
272 	if (imsg_compose(ibuf, GOT_IMSG_BLOB_OUTFD, 0, 0, outfd, NULL, 0)
273 	    == -1)
274 		return got_error_from_errno();
275 
276 	return flush_imsg(ibuf);
277 }
278 
279 const struct got_error *
280 got_privsep_send_tmpfd(struct imsgbuf *ibuf, int fd)
281 {
282 	if (imsg_compose(ibuf, GOT_IMSG_TMPFD, 0, 0, fd, NULL, 0)
283 	    == -1)
284 		return got_error_from_errno();
285 
286 	return flush_imsg(ibuf);
287 }
288 
289 const struct got_error *
290 got_privsep_send_obj(struct imsgbuf *ibuf, struct got_object *obj)
291 {
292 	struct got_imsg_object iobj;
293 
294 	memcpy(iobj.id, obj->id.sha1, sizeof(iobj.id));
295 	iobj.type = obj->type;
296 	iobj.flags = obj->flags;
297 	iobj.hdrlen = obj->hdrlen;
298 	iobj.size = obj->size;
299 	if (iobj.flags & GOT_OBJ_FLAG_PACKED) {
300 		iobj.pack_offset = obj->pack_offset;
301 		iobj.pack_idx = obj->pack_idx;
302 	}
303 
304 	if (imsg_compose(ibuf, GOT_IMSG_OBJECT, 0, 0, -1, &iobj, sizeof(iobj))
305 	    == -1)
306 		return got_error_from_errno();
307 
308 	return flush_imsg(ibuf);
309 }
310 
311 const struct got_error *
312 got_privsep_get_imsg_obj(struct got_object **obj, struct imsg *imsg,
313     struct imsgbuf *ibuf)
314 {
315 	const struct got_error *err = NULL;
316 	struct got_imsg_object iobj;
317 	size_t datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
318 
319 	if (datalen != sizeof(iobj))
320 		return got_error(GOT_ERR_PRIVSEP_LEN);
321 
322 	memcpy(&iobj, imsg->data, sizeof(iobj));
323 
324 	*obj = calloc(1, sizeof(**obj));
325 	if (*obj == NULL)
326 		return got_error_from_errno();
327 
328 	memcpy((*obj)->id.sha1, iobj.id, SHA1_DIGEST_LENGTH);
329 	(*obj)->type = iobj.type;
330 	(*obj)->flags = iobj.flags;
331 	(*obj)->hdrlen = iobj.hdrlen;
332 	(*obj)->size = iobj.size;
333 	/* path_packfile is handled by caller */
334 	if (iobj.flags & GOT_OBJ_FLAG_PACKED) {
335 		(*obj)->pack_offset = iobj.pack_offset;
336 		(*obj)->pack_idx = iobj.pack_idx;
337 	}
338 
339 	return err;
340 }
341 
342 const struct got_error *
343 got_privsep_recv_obj(struct got_object **obj, struct imsgbuf *ibuf)
344 {
345 	const struct got_error *err = NULL;
346 	struct imsg imsg;
347 	size_t datalen;
348 	const size_t min_datalen =
349 	    MIN(sizeof(struct got_imsg_error), sizeof(struct got_imsg_object));
350 
351 	*obj = NULL;
352 
353 	err = got_privsep_recv_imsg(&imsg, ibuf, min_datalen);
354 	if (err)
355 		return err;
356 
357 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
358 
359 	switch (imsg.hdr.type) {
360 	case GOT_IMSG_ERROR:
361 		err = recv_imsg_error(&imsg, datalen);
362 		break;
363 	case GOT_IMSG_OBJECT:
364 		err = got_privsep_get_imsg_obj(obj, &imsg, ibuf);
365 		break;
366 	default:
367 		err = got_error(GOT_ERR_PRIVSEP_MSG);
368 		break;
369 	}
370 
371 	imsg_free(&imsg);
372 
373 	return err;
374 }
375 
376 static const struct got_error *
377 send_commit_logmsg(struct imsgbuf *ibuf, struct got_commit_object *commit,
378     size_t logmsg_len)
379 {
380 	const struct got_error *err = NULL;
381 	size_t offset, remain;
382 
383 	offset = 0;
384 	remain = logmsg_len;
385 	while (remain > 0) {
386 		size_t n = MIN(MAX_IMSGSIZE - IMSG_HEADER_SIZE, remain);
387 
388 		if (imsg_compose(ibuf, GOT_IMSG_COMMIT_LOGMSG, 0, 0, -1,
389 		    commit->logmsg + offset, n) == -1) {
390 			err = got_error_from_errno();
391 			break;
392 		}
393 
394 		err = flush_imsg(ibuf);
395 		if (err)
396 			break;
397 
398 		offset += n;
399 		remain -= n;
400 	}
401 
402 	return err;
403 }
404 
405 const struct got_error *
406 got_privsep_send_commit(struct imsgbuf *ibuf, struct got_commit_object *commit)
407 {
408 	const struct got_error *err = NULL;
409 	struct got_imsg_commit_object icommit;
410 	uint8_t *buf;
411 	size_t len, total;
412 	struct got_object_qid *qid;
413 	size_t logmsg_len = strlen(commit->logmsg);
414 
415 	memcpy(icommit.tree_id, commit->tree_id->sha1, sizeof(icommit.tree_id));
416 	icommit.author_len = strlen(commit->author);
417 	icommit.author_time = commit->author_time;
418 	icommit.author_gmtoff = commit->author_gmtoff;
419 	icommit.committer_len = strlen(commit->committer);
420 	icommit.committer_time = commit->committer_time;
421 	icommit.committer_gmtoff = commit->committer_gmtoff;
422 	icommit.logmsg_len = logmsg_len;
423 	icommit.nparents = commit->nparents;
424 
425 	total = sizeof(icommit) + icommit.author_len +
426 	    icommit.committer_len + icommit.nparents * SHA1_DIGEST_LENGTH;
427 
428 	buf = malloc(total);
429 	if (buf == NULL)
430 		return got_error_from_errno();
431 
432 	len = 0;
433 	memcpy(buf + len, &icommit, sizeof(icommit));
434 	len += sizeof(icommit);
435 	memcpy(buf + len, commit->author, icommit.author_len);
436 	len += icommit.author_len;
437 	memcpy(buf + len, commit->committer, icommit.committer_len);
438 	len += icommit.committer_len;
439 	SIMPLEQ_FOREACH(qid, &commit->parent_ids, entry) {
440 		memcpy(buf + len, qid->id, SHA1_DIGEST_LENGTH);
441 		len += SHA1_DIGEST_LENGTH;
442 	}
443 
444 	if (imsg_compose(ibuf, GOT_IMSG_COMMIT, 0, 0, -1, buf, len) == -1) {
445 		err = got_error_from_errno();
446 		goto done;
447 	}
448 
449 	if (logmsg_len == 0 ||
450 	    logmsg_len + len > MAX_IMSGSIZE - IMSG_HEADER_SIZE) {
451 		err = flush_imsg(ibuf);
452 		if (err)
453 			goto done;
454 	}
455 	err = send_commit_logmsg(ibuf, commit, logmsg_len);
456 done:
457 	free(buf);
458 	return err;
459 }
460 
461 const struct got_error *
462 got_privsep_recv_commit(struct got_commit_object **commit, struct imsgbuf *ibuf)
463 {
464 	const struct got_error *err = NULL;
465 	struct imsg imsg;
466 	struct got_imsg_commit_object icommit;
467 	size_t len, datalen;
468 	int i;
469 	const size_t min_datalen =
470 	    MIN(sizeof(struct got_imsg_error),
471 	    sizeof(struct got_imsg_commit_object));
472 	uint8_t *data;
473 
474 	*commit = NULL;
475 
476 	err = got_privsep_recv_imsg(&imsg, ibuf, min_datalen);
477 	if (err)
478 		return err;
479 
480 	data = imsg.data;
481 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
482 	len = 0;
483 
484 	switch (imsg.hdr.type) {
485 	case GOT_IMSG_ERROR:
486 		err = recv_imsg_error(&imsg, datalen);
487 		break;
488 	case GOT_IMSG_COMMIT:
489 		if (datalen < sizeof(icommit)) {
490 			err = got_error(GOT_ERR_PRIVSEP_LEN);
491 			break;
492 		}
493 
494 		memcpy(&icommit, data, sizeof(icommit));
495 		if (datalen != sizeof(icommit) + icommit.author_len +
496 		    icommit.committer_len +
497 		    icommit.nparents * SHA1_DIGEST_LENGTH) {
498 			err = got_error(GOT_ERR_PRIVSEP_LEN);
499 			break;
500 		}
501 		if (icommit.nparents < 0) {
502 			err = got_error(GOT_ERR_PRIVSEP_LEN);
503 			break;
504 		}
505 		len += sizeof(icommit);
506 
507 		*commit = got_object_commit_alloc_partial();
508 		if (*commit == NULL) {
509 			err = got_error_from_errno();
510 			break;
511 		}
512 
513 		memcpy((*commit)->tree_id->sha1, icommit.tree_id,
514 		    SHA1_DIGEST_LENGTH);
515 		(*commit)->author_time = icommit.author_time;
516 		(*commit)->author_gmtoff = icommit.author_gmtoff;
517 		(*commit)->committer_time = icommit.committer_time;
518 		(*commit)->committer_gmtoff = icommit.committer_gmtoff;
519 
520 		if (icommit.author_len == 0) {
521 			(*commit)->author = strdup("");
522 			if ((*commit)->author == NULL) {
523 				err = got_error_from_errno();
524 				break;
525 			}
526 		} else {
527 			(*commit)->author = malloc(icommit.author_len + 1);
528 			if ((*commit)->author == NULL) {
529 				err = got_error_from_errno();
530 				break;
531 			}
532 			memcpy((*commit)->author, data + len,
533 			    icommit.author_len);
534 			(*commit)->author[icommit.author_len] = '\0';
535 		}
536 		len += icommit.author_len;
537 
538 		if (icommit.committer_len == 0) {
539 			(*commit)->committer = strdup("");
540 			if ((*commit)->committer == NULL) {
541 				err = got_error_from_errno();
542 				break;
543 			}
544 		} else {
545 			(*commit)->committer =
546 			    malloc(icommit.committer_len + 1);
547 			if ((*commit)->committer == NULL) {
548 				err = got_error_from_errno();
549 				break;
550 			}
551 			memcpy((*commit)->committer, data + len,
552 			    icommit.committer_len);
553 			(*commit)->committer[icommit.committer_len] = '\0';
554 		}
555 		len += icommit.committer_len;
556 
557 		if (icommit.logmsg_len == 0) {
558 			(*commit)->logmsg = strdup("");
559 			if ((*commit)->logmsg == NULL) {
560 				err = got_error_from_errno();
561 				break;
562 			}
563 		} else {
564 			size_t offset = 0, remain = icommit.logmsg_len;
565 
566 			(*commit)->logmsg = malloc(icommit.logmsg_len + 1);
567 			if ((*commit)->logmsg == NULL) {
568 				err = got_error_from_errno();
569 				break;
570 			}
571 			while (remain > 0) {
572 				struct imsg imsg_log;
573 				size_t n = MIN(MAX_IMSGSIZE - IMSG_HEADER_SIZE,
574 				    remain);
575 
576 				err = got_privsep_recv_imsg(&imsg_log, ibuf, n);
577 				if (err)
578 					return err;
579 
580 				if (imsg_log.hdr.type != GOT_IMSG_COMMIT_LOGMSG)
581 					return got_error(GOT_ERR_PRIVSEP_MSG);
582 
583 				memcpy((*commit)->logmsg + offset,
584 				    imsg_log.data, n);
585 				imsg_free(&imsg_log);
586 				offset += n;
587 				remain -= n;
588 			}
589 			(*commit)->logmsg[icommit.logmsg_len] = '\0';
590 		}
591 
592 		for (i = 0; i < icommit.nparents; i++) {
593 			struct got_object_qid *qid;
594 
595 			err = got_object_qid_alloc_partial(&qid);
596 			if (err)
597 				break;
598 			memcpy(qid->id, data + len + i * SHA1_DIGEST_LENGTH,
599 			    sizeof(*qid->id));
600 			SIMPLEQ_INSERT_TAIL(&(*commit)->parent_ids, qid, entry);
601 			(*commit)->nparents++;
602 		}
603 		break;
604 	default:
605 		err = got_error(GOT_ERR_PRIVSEP_MSG);
606 		break;
607 	}
608 
609 	imsg_free(&imsg);
610 
611 	return err;
612 }
613 
614 const struct got_error *
615 got_privsep_send_tree(struct imsgbuf *ibuf, struct got_tree_object *tree)
616 {
617 	const struct got_error *err = NULL;
618 	struct got_imsg_tree_object itree;
619 	struct got_tree_entry *te;
620 	size_t totlen;
621 	int nimsg; /* number of imsg queued in ibuf */
622 
623 	itree.nentries = tree->entries.nentries;
624 	if (imsg_compose(ibuf, GOT_IMSG_TREE, 0, 0, -1, &itree, sizeof(itree))
625 	    == -1)
626 		return got_error_from_errno();
627 
628 	totlen = sizeof(itree);
629 	nimsg = 1;
630 	SIMPLEQ_FOREACH(te, &tree->entries.head, entry) {
631 		struct got_imsg_tree_entry ite;
632 		uint8_t *buf = NULL;
633 		size_t len = sizeof(ite) + strlen(te->name);
634 
635 		if (len > MAX_IMSGSIZE)
636 			return got_error(GOT_ERR_NO_SPACE);
637 
638 		nimsg++;
639 		if (totlen + len >= MAX_IMSGSIZE - (IMSG_HEADER_SIZE * nimsg)) {
640 			err = flush_imsg(ibuf);
641 			if (err)
642 				return err;
643 			nimsg = 0;
644 		}
645 
646 		buf = malloc(len);
647 		if (buf == NULL)
648 			return got_error_from_errno();
649 
650 		memcpy(ite.id, te->id->sha1, sizeof(ite.id));
651 		ite.mode = te->mode;
652 		memcpy(buf, &ite, sizeof(ite));
653 		memcpy(buf + sizeof(ite), te->name, strlen(te->name));
654 
655 		if (imsg_compose(ibuf, GOT_IMSG_TREE_ENTRY, 0, 0, -1,
656 		    buf, len) == -1)
657 			err = got_error_from_errno();
658 		free(buf);
659 		if (err)
660 			return err;
661 		totlen += len;
662 	}
663 
664 	return flush_imsg(ibuf);
665 }
666 
667 const struct got_error *
668 got_privsep_recv_tree(struct got_tree_object **tree, struct imsgbuf *ibuf)
669 {
670 	const struct got_error *err = NULL;
671 	const size_t min_datalen =
672 	    MIN(sizeof(struct got_imsg_error),
673 	    sizeof(struct got_imsg_tree_object));
674 	struct got_imsg_tree_object itree = { 0 };
675 	int nentries = 0;
676 
677 	*tree = NULL;
678 get_more:
679 	err = read_imsg(ibuf);
680 	if (err)
681 		goto done;
682 
683 	while (1) {
684 		struct imsg imsg;
685 		size_t n;
686 		size_t datalen;
687 		struct got_imsg_tree_entry ite;
688 		struct got_tree_entry *te = NULL;
689 
690 		n = imsg_get(ibuf, &imsg);
691 		if (n == 0) {
692 			if (*tree && (*tree)->entries.nentries != nentries)
693 				goto get_more;
694 			break;
695 		}
696 
697 		if (imsg.hdr.len < IMSG_HEADER_SIZE + min_datalen)
698 			return got_error(GOT_ERR_PRIVSEP_LEN);
699 
700 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
701 
702 		switch (imsg.hdr.type) {
703 		case GOT_IMSG_ERROR:
704 			err = recv_imsg_error(&imsg, datalen);
705 			break;
706 		case GOT_IMSG_TREE:
707 			/* This message should only appear once. */
708 			if (*tree != NULL) {
709 				err = got_error(GOT_ERR_PRIVSEP_MSG);
710 				break;
711 			}
712 			if (datalen != sizeof(itree)) {
713 				err = got_error(GOT_ERR_PRIVSEP_LEN);
714 				break;
715 			}
716 			memcpy(&itree, imsg.data, sizeof(itree));
717 			*tree = calloc(1, sizeof(**tree));
718 			if (*tree == NULL) {
719 				err = got_error_from_errno();
720 				break;
721 			}
722 			(*tree)->entries.nentries = itree.nentries;
723 			SIMPLEQ_INIT(&(*tree)->entries.head);
724 			break;
725 		case GOT_IMSG_TREE_ENTRY:
726 			/* This message should be preceeded by GOT_IMSG_TREE. */
727 			if (*tree == NULL) {
728 				err = got_error(GOT_ERR_PRIVSEP_MSG);
729 				break;
730 			}
731 			if (datalen < sizeof(ite) || datalen > MAX_IMSGSIZE) {
732 				err = got_error(GOT_ERR_PRIVSEP_LEN);
733 				break;
734 			}
735 
736 			/* Remaining data contains the entry's name. */
737 			datalen -= sizeof(ite);
738 			memcpy(&ite, imsg.data, sizeof(ite));
739 			if (datalen == 0 || datalen > MAX_IMSGSIZE) {
740 				err = got_error(GOT_ERR_PRIVSEP_LEN);
741 				break;
742 			}
743 
744 			te = got_alloc_tree_entry_partial();
745 			if (te == NULL) {
746 				err = got_error_from_errno();
747 				break;
748 			}
749 			te->name = malloc(datalen + 1);
750 			if (te->name == NULL) {
751 				free(te);
752 				err = got_error_from_errno();
753 				break;
754 			}
755 			memcpy(te->name, imsg.data + sizeof(ite), datalen);
756 			te->name[datalen] = '\0';
757 
758 			memcpy(te->id->sha1, ite.id, SHA1_DIGEST_LENGTH);
759 			te->mode = ite.mode;
760 			SIMPLEQ_INSERT_TAIL(&(*tree)->entries.head, te, entry);
761 			nentries++;
762 			break;
763 		default:
764 			err = got_error(GOT_ERR_PRIVSEP_MSG);
765 			break;
766 		}
767 
768 		imsg_free(&imsg);
769 	}
770 done:
771 	if (*tree && (*tree)->entries.nentries != nentries) {
772 		if (err == NULL)
773 			err = got_error(GOT_ERR_PRIVSEP_LEN);
774 		got_object_tree_close(*tree);
775 		*tree = NULL;
776 	}
777 
778 	return err;
779 }
780 
781 const struct got_error *
782 got_privsep_send_blob(struct imsgbuf *ibuf, size_t size)
783 {
784 	struct got_imsg_blob iblob;
785 
786 	iblob.size = size;
787 	/* Data has already been written to file descriptor. */
788 
789 	if (imsg_compose(ibuf, GOT_IMSG_BLOB, 0, 0, -1, &iblob, sizeof(iblob))
790 	    == -1)
791 		return got_error_from_errno();
792 
793 	return flush_imsg(ibuf);
794 }
795 
796 const struct got_error *
797 got_privsep_recv_blob(size_t *size, struct imsgbuf *ibuf)
798 {
799 	const struct got_error *err = NULL;
800 	struct imsg imsg;
801 	struct got_imsg_blob iblob;
802 	size_t datalen;
803 
804 	err = got_privsep_recv_imsg(&imsg, ibuf, 0);
805 	if (err)
806 		return err;
807 
808 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
809 
810 	switch (imsg.hdr.type) {
811 	case GOT_IMSG_ERROR:
812 		err = recv_imsg_error(&imsg, datalen);
813 		break;
814 	case GOT_IMSG_BLOB:
815 		if (datalen != sizeof(iblob)) {
816 			err = got_error(GOT_ERR_PRIVSEP_LEN);
817 			break;
818 		}
819 		memcpy(&iblob, imsg.data, sizeof(iblob));
820 		*size = iblob.size;
821 		/* Data has been written to file descriptor. */
822 		break;
823 	default:
824 		err = got_error(GOT_ERR_PRIVSEP_MSG);
825 		break;
826 	}
827 
828 	imsg_free(&imsg);
829 
830 	return err;
831 }
832 
833 const struct got_error *
834 got_privsep_init_pack_child(struct imsgbuf *ibuf, struct got_pack *pack,
835     struct got_packidx *packidx)
836 {
837 	struct got_imsg_packidx ipackidx;
838 	struct got_imsg_pack ipack;
839 	int fd;
840 
841 	ipackidx.len = packidx->len;
842 	fd = dup(packidx->fd);
843 	if (fd == -1)
844 		return got_error_from_errno();
845 
846 	if (imsg_compose(ibuf, GOT_IMSG_PACKIDX, 0, 0, fd, &ipackidx,
847 	    sizeof(ipackidx)) == -1)
848 		return got_error_from_errno();
849 
850 	if (strlcpy(ipack.path_packfile, pack->path_packfile,
851 	    sizeof(ipack.path_packfile)) >= sizeof(ipack.path_packfile))
852 		return got_error(GOT_ERR_NO_SPACE);
853 	ipack.filesize = pack->filesize;
854 
855 	fd = dup(pack->fd);
856 	if (fd == -1)
857 		return got_error_from_errno();
858 
859 	if (imsg_compose(ibuf, GOT_IMSG_PACK, 0, 0, fd, &ipack, sizeof(ipack))
860 	    == -1)
861 		return got_error_from_errno();
862 
863 	return flush_imsg(ibuf);
864 }
865 
866 const struct got_error *
867 got_privsep_send_packed_obj_req(struct imsgbuf *ibuf, int idx,
868     struct got_object_id *id)
869 {
870 	struct got_imsg_packed_object iobj;
871 
872 	iobj.idx = idx;
873 	memcpy(iobj.id, id->sha1, sizeof(iobj.id));
874 
875 	if (imsg_compose(ibuf, GOT_IMSG_PACKED_OBJECT_REQUEST, 0, 0, -1,
876 	    &iobj, sizeof(iobj)) == -1)
877 		return got_error_from_errno();
878 
879 	return flush_imsg(ibuf);
880 }