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Date:: Tue Sep 11 10:57:03 2018 UTC
Message:: support commit log messages larger than the maximum imsg size
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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_obj(struct imsgbuf *ibuf, struct got_object *obj)
281 {
282 	struct got_imsg_object iobj;
283 
284 	memcpy(iobj.id, obj->id.sha1, sizeof(iobj.id));
285 	iobj.type = obj->type;
286 	iobj.flags = obj->flags;
287 	iobj.hdrlen = obj->hdrlen;
288 	iobj.size = obj->size;
289 	if (iobj.flags & GOT_OBJ_FLAG_PACKED) {
290 		iobj.pack_offset = obj->pack_offset;
291 		iobj.pack_idx = obj->pack_idx;
292 	}
293 
294 	if (imsg_compose(ibuf, GOT_IMSG_OBJECT, 0, 0, -1, &iobj, sizeof(iobj))
295 	    == -1)
296 		return got_error_from_errno();
297 
298 	return flush_imsg(ibuf);
299 }
300 
301 const struct got_error *
302 got_privsep_get_imsg_obj(struct got_object **obj, struct imsg *imsg,
303     struct imsgbuf *ibuf)
304 {
305 	const struct got_error *err = NULL;
306 	struct got_imsg_object iobj;
307 	size_t datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
308 
309 	if (datalen != sizeof(iobj))
310 		return got_error(GOT_ERR_PRIVSEP_LEN);
311 
312 	memcpy(&iobj, imsg->data, sizeof(iobj));
313 
314 	*obj = calloc(1, sizeof(**obj));
315 	if (*obj == NULL)
316 		return got_error_from_errno();
317 
318 	memcpy((*obj)->id.sha1, iobj.id, SHA1_DIGEST_LENGTH);
319 	(*obj)->type = iobj.type;
320 	(*obj)->flags = iobj.flags;
321 	(*obj)->hdrlen = iobj.hdrlen;
322 	(*obj)->size = iobj.size;
323 	/* path_packfile is handled by caller */
324 	if (iobj.flags & GOT_OBJ_FLAG_PACKED) {
325 		(*obj)->pack_offset = iobj.pack_offset;
326 		(*obj)->pack_idx = iobj.pack_idx;
327 	}
328 
329 	return err;
330 }
331 
332 const struct got_error *
333 got_privsep_recv_obj(struct got_object **obj, struct imsgbuf *ibuf)
334 {
335 	const struct got_error *err = NULL;
336 	struct imsg imsg;
337 	size_t datalen;
338 	const size_t min_datalen =
339 	    MIN(sizeof(struct got_imsg_error), sizeof(struct got_imsg_object));
340 
341 	*obj = NULL;
342 
343 	err = got_privsep_recv_imsg(&imsg, ibuf, min_datalen);
344 	if (err)
345 		return err;
346 
347 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
348 
349 	switch (imsg.hdr.type) {
350 	case GOT_IMSG_ERROR:
351 		err = recv_imsg_error(&imsg, datalen);
352 		break;
353 	case GOT_IMSG_OBJECT:
354 		err = got_privsep_get_imsg_obj(obj, &imsg, ibuf);
355 		break;
356 	default:
357 		err = got_error(GOT_ERR_PRIVSEP_MSG);
358 		break;
359 	}
360 
361 	imsg_free(&imsg);
362 
363 	return err;
364 }
365 
366 static const struct got_error *
367 send_commit_logmsg(struct imsgbuf *ibuf, struct got_commit_object *commit,
368     size_t logmsg_len)
369 {
370 	size_t offset, remain;
371 
372 	offset = 0;
373 	remain = logmsg_len;
374 	while (remain > 0) {
375 		size_t n = MIN(MAX_IMSGSIZE - IMSG_HEADER_SIZE, remain);
376 
377 		if (imsg_compose(ibuf, GOT_IMSG_COMMIT_LOGMSG, 0, 0, -1,
378 		    commit->logmsg + offset, n) == -1)
379 			return got_error_from_errno();
380 
381 		if (imsg_flush(ibuf) == -1)
382 			return got_error_from_errno();
383 
384 		offset += n;
385 		remain -= n;
386 	}
387 
388 	return NULL;
389 }
390 
391 const struct got_error *
392 got_privsep_send_commit(struct imsgbuf *ibuf, struct got_commit_object *commit)
393 {
394 	const struct got_error *err = NULL;
395 	struct got_imsg_commit_object icommit;
396 	uint8_t *buf;
397 	size_t len, total;
398 	struct got_object_qid *qid;
399 	size_t logmsg_len = strlen(commit->logmsg);
400 
401 	memcpy(icommit.tree_id, commit->tree_id->sha1, sizeof(icommit.tree_id));
402 	icommit.author_len = strlen(commit->author);
403 	memcpy(&icommit.tm_author, &commit->tm_author,
404 	    sizeof(icommit.tm_author));
405 	icommit.committer_len = strlen(commit->committer);
406 	memcpy(&icommit.tm_committer, &commit->tm_committer,
407 	    sizeof(icommit.tm_committer));
408 	icommit.logmsg_len = logmsg_len;
409 	icommit.nparents = commit->nparents;
410 
411 	total = sizeof(icommit) + icommit.author_len +
412 	    icommit.committer_len + icommit.nparents * SHA1_DIGEST_LENGTH;
413 
414 	buf = malloc(total);
415 	if (buf == NULL)
416 		return got_error_from_errno();
417 
418 	len = 0;
419 	memcpy(buf + len, &icommit, sizeof(icommit));
420 	len += sizeof(icommit);
421 	memcpy(buf + len, commit->author, icommit.author_len);
422 	len += icommit.author_len;
423 	memcpy(buf + len, commit->committer, icommit.committer_len);
424 	len += icommit.committer_len;
425 	SIMPLEQ_FOREACH(qid, &commit->parent_ids, entry) {
426 		memcpy(buf + len, qid->id, SHA1_DIGEST_LENGTH);
427 		len += SHA1_DIGEST_LENGTH;
428 	}
429 
430 	if (imsg_compose(ibuf, GOT_IMSG_COMMIT, 0, 0, -1, buf, len) == -1) {
431 		err = got_error_from_errno();
432 		goto done;
433 	}
434 
435 	err = flush_imsg(ibuf);
436 	if (err)
437 		goto done;
438 
439 	err = send_commit_logmsg(ibuf, commit, logmsg_len);
440 done:
441 	free(buf);
442 	return err;
443 }
444 
445 const struct got_error *
446 got_privsep_recv_commit(struct got_commit_object **commit, struct imsgbuf *ibuf)
447 {
448 	const struct got_error *err = NULL;
449 	struct imsg imsg;
450 	struct got_imsg_commit_object icommit;
451 	size_t len, datalen;
452 	int i;
453 	const size_t min_datalen =
454 	    MIN(sizeof(struct got_imsg_error),
455 	    sizeof(struct got_imsg_commit_object));
456 	uint8_t *data;
457 
458 	*commit = NULL;
459 
460 	err = got_privsep_recv_imsg(&imsg, ibuf, min_datalen);
461 	if (err)
462 		return err;
463 
464 	data = imsg.data;
465 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
466 	len = 0;
467 
468 	switch (imsg.hdr.type) {
469 	case GOT_IMSG_ERROR:
470 		err = recv_imsg_error(&imsg, datalen);
471 		break;
472 	case GOT_IMSG_COMMIT:
473 		if (datalen < sizeof(icommit)) {
474 			err = got_error(GOT_ERR_PRIVSEP_LEN);
475 			break;
476 		}
477 
478 		memcpy(&icommit, data, sizeof(icommit));
479 		if (datalen != sizeof(icommit) + icommit.author_len +
480 		    icommit.committer_len +
481 		    icommit.nparents * SHA1_DIGEST_LENGTH) {
482 			err = got_error(GOT_ERR_PRIVSEP_LEN);
483 			break;
484 		}
485 		if (icommit.nparents < 0) {
486 			err = got_error(GOT_ERR_PRIVSEP_LEN);
487 			break;
488 		}
489 		len += sizeof(icommit);
490 
491 		*commit = got_object_commit_alloc_partial();
492 		if (*commit == NULL) {
493 			err = got_error_from_errno();
494 			break;
495 		}
496 
497 		memcpy((*commit)->tree_id->sha1, icommit.tree_id,
498 		    SHA1_DIGEST_LENGTH);
499 		memcpy(&(*commit)->tm_author, &icommit.tm_author,
500 		    sizeof((*commit)->tm_author));
501 		memcpy(&(*commit)->tm_committer, &icommit.tm_committer,
502 		    sizeof((*commit)->tm_committer));
503 
504 		if (icommit.author_len == 0) {
505 			(*commit)->author = strdup("");
506 			if ((*commit)->author == NULL) {
507 				err = got_error_from_errno();
508 				break;
509 			}
510 		} else {
511 			(*commit)->author = malloc(icommit.author_len + 1);
512 			if ((*commit)->author == NULL) {
513 				err = got_error_from_errno();
514 				break;
515 			}
516 			memcpy((*commit)->author, data + len,
517 			    icommit.author_len);
518 			(*commit)->author[icommit.author_len] = '\0';
519 		}
520 		len += icommit.author_len;
521 
522 		if (icommit.committer_len == 0) {
523 			(*commit)->committer = strdup("");
524 			if ((*commit)->committer == NULL) {
525 				err = got_error_from_errno();
526 				break;
527 			}
528 		} else {
529 			(*commit)->committer =
530 			    malloc(icommit.committer_len + 1);
531 			if ((*commit)->committer == NULL) {
532 				err = got_error_from_errno();
533 				break;
534 			}
535 			memcpy((*commit)->committer, data + len,
536 			    icommit.committer_len);
537 			(*commit)->committer[icommit.committer_len] = '\0';
538 		}
539 		len += icommit.committer_len;
540 
541 		if (icommit.logmsg_len == 0) {
542 			(*commit)->logmsg = strdup("");
543 			if ((*commit)->logmsg == NULL) {
544 				err = got_error_from_errno();
545 				break;
546 			}
547 		} else {
548 			size_t offset = 0, remain = icommit.logmsg_len;
549 
550 			(*commit)->logmsg = malloc(icommit.logmsg_len + 1);
551 			if ((*commit)->logmsg == NULL) {
552 				err = got_error_from_errno();
553 				break;
554 			}
555 			while (remain > 0) {
556 				struct imsg imsg_log;
557 				size_t n = MIN(MAX_IMSGSIZE - IMSG_HEADER_SIZE,
558 				    remain);
559 
560 				err = got_privsep_recv_imsg(&imsg_log, ibuf, n);
561 				if (err)
562 					return err;
563 
564 				if (imsg_log.hdr.type != GOT_IMSG_COMMIT_LOGMSG)
565 					return got_error(GOT_ERR_PRIVSEP_MSG);
566 
567 				memcpy((*commit)->logmsg + offset,
568 				    imsg_log.data, n);
569 				imsg_free(&imsg_log);
570 				offset += n;
571 				remain -= n;
572 			}
573 			(*commit)->logmsg[icommit.logmsg_len] = '\0';
574 		}
575 
576 		for (i = 0; i < icommit.nparents; i++) {
577 			struct got_object_qid *qid;
578 
579 			qid = calloc(1, sizeof(*qid));
580 			if (qid == NULL) {
581 				err = got_error_from_errno();
582 				break;
583 			}
584 			qid->id = calloc(1, sizeof(*qid->id));
585 			if (qid->id == NULL) {
586 				err = got_error_from_errno();
587 				free(qid);
588 				break;
589 			}
590 
591 			memcpy(qid->id, data + len + i * SHA1_DIGEST_LENGTH,
592 			    sizeof(*qid->id));
593 			SIMPLEQ_INSERT_TAIL(&(*commit)->parent_ids, qid, entry);
594 			(*commit)->nparents++;
595 		}
596 		break;
597 	default:
598 		err = got_error(GOT_ERR_PRIVSEP_MSG);
599 		break;
600 	}
601 
602 	imsg_free(&imsg);
603 
604 	return err;
605 }
606 
607 const struct got_error *
608 got_privsep_send_tree(struct imsgbuf *ibuf, struct got_tree_object *tree)
609 {
610 	const struct got_error *err = NULL;
611 	struct got_imsg_tree_object itree;
612 	struct got_tree_entry *te;
613 
614 	itree.nentries = tree->entries.nentries;
615 	if (imsg_compose(ibuf, GOT_IMSG_TREE, 0, 0, -1, &itree, sizeof(itree))
616 	    == -1)
617 		return got_error_from_errno();
618 
619 	err = flush_imsg(ibuf);
620 	if (err)
621 		return err;
622 
623 	SIMPLEQ_FOREACH(te, &tree->entries.head, entry) {
624 		struct got_imsg_tree_entry ite;
625 		uint8_t *buf = NULL;
626 		size_t len = sizeof(ite) + strlen(te->name);
627 
628 		if (len > MAX_IMSGSIZE)
629 			return got_error(GOT_ERR_NO_SPACE);
630 
631 		buf = malloc(len);
632 		if (buf == NULL)
633 			return got_error_from_errno();
634 
635 		memcpy(ite.id, te->id->sha1, sizeof(ite.id));
636 		ite.mode = te->mode;
637 		memcpy(buf, &ite, sizeof(ite));
638 		memcpy(buf + sizeof(ite), te->name, strlen(te->name));
639 
640 		if (imsg_compose(ibuf, GOT_IMSG_TREE_ENTRY, 0, 0, -1,
641 		    buf, len) == -1)
642 			err = got_error_from_errno();
643 		free(buf);
644 		if (err)
645 			return err;
646 
647 		err = flush_imsg(ibuf);
648 		if (err)
649 			return err;
650 	}
651 
652 	return NULL;
653 }
654 
655 const struct got_error *
656 got_privsep_recv_tree(struct got_tree_object **tree, struct imsgbuf *ibuf)
657 {
658 	const struct got_error *err = NULL;
659 	const size_t min_datalen =
660 	    MIN(sizeof(struct got_imsg_error),
661 	    sizeof(struct got_imsg_tree_object));
662 	struct got_imsg_tree_object itree = { 0 };
663 	int nentries = 0;
664 
665 	*tree = NULL;
666 get_more:
667 	err = read_imsg(ibuf);
668 	if (err)
669 		goto done;
670 
671 	while (1) {
672 		struct imsg imsg;
673 		size_t n;
674 		size_t datalen;
675 		struct got_imsg_tree_entry ite;
676 		struct got_tree_entry *te = NULL;
677 
678 		n = imsg_get(ibuf, &imsg);
679 		if (n == 0) {
680 			if (*tree && (*tree)->entries.nentries != nentries)
681 				goto get_more;
682 			break;
683 		}
684 
685 		if (imsg.hdr.len < IMSG_HEADER_SIZE + min_datalen)
686 			return got_error(GOT_ERR_PRIVSEP_LEN);
687 
688 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
689 
690 		switch (imsg.hdr.type) {
691 		case GOT_IMSG_ERROR:
692 			err = recv_imsg_error(&imsg, datalen);
693 			break;
694 		case GOT_IMSG_TREE:
695 			/* This message should only appear once. */
696 			if (*tree != NULL) {
697 				err = got_error(GOT_ERR_PRIVSEP_MSG);
698 				break;
699 			}
700 			if (datalen != sizeof(itree)) {
701 				err = got_error(GOT_ERR_PRIVSEP_LEN);
702 				break;
703 			}
704 			memcpy(&itree, imsg.data, sizeof(itree));
705 			*tree = calloc(1, sizeof(**tree));
706 			if (*tree == NULL) {
707 				err = got_error_from_errno();
708 				break;
709 			}
710 			(*tree)->entries.nentries = itree.nentries;
711 			SIMPLEQ_INIT(&(*tree)->entries.head);
712 			break;
713 		case GOT_IMSG_TREE_ENTRY:
714 			/* This message should be preceeded by GOT_IMSG_TREE. */
715 			if (*tree == NULL) {
716 				err = got_error(GOT_ERR_PRIVSEP_MSG);
717 				break;
718 			}
719 			if (datalen < sizeof(ite) || datalen > MAX_IMSGSIZE) {
720 				err = got_error(GOT_ERR_PRIVSEP_LEN);
721 				break;
722 			}
723 
724 			/* Remaining data contains the entry's name. */
725 			datalen -= sizeof(ite);
726 			memcpy(&ite, imsg.data, sizeof(ite));
727 			if (datalen == 0 || datalen > MAX_IMSGSIZE) {
728 				err = got_error(GOT_ERR_PRIVSEP_LEN);
729 				break;
730 			}
731 
732 			te = got_alloc_tree_entry_partial();
733 			if (te == NULL) {
734 				err = got_error_from_errno();
735 				break;
736 			}
737 			te->name = malloc(datalen + 1);
738 			if (te->name == NULL) {
739 				free(te);
740 				err = got_error_from_errno();
741 				break;
742 			}
743 			memcpy(te->name, imsg.data + sizeof(ite), datalen);
744 			te->name[datalen] = '\0';
745 
746 			memcpy(te->id->sha1, ite.id, SHA1_DIGEST_LENGTH);
747 			te->mode = ite.mode;
748 			SIMPLEQ_INSERT_TAIL(&(*tree)->entries.head, te, entry);
749 			nentries++;
750 			break;
751 		default:
752 			err = got_error(GOT_ERR_PRIVSEP_MSG);
753 			break;
754 		}
755 
756 		imsg_free(&imsg);
757 	}
758 done:
759 	if (*tree && (*tree)->entries.nentries != nentries) {
760 		if (err == NULL)
761 			err = got_error(GOT_ERR_PRIVSEP_LEN);
762 		got_object_tree_close(*tree);
763 		*tree = NULL;
764 	}
765 
766 	return err;
767 }
768 
769 const struct got_error *
770 got_privsep_send_blob(struct imsgbuf *ibuf, size_t size)
771 {
772 	struct got_imsg_blob iblob;
773 
774 	iblob.size = size;
775 	/* Data has already been written to file descriptor. */
776 
777 	if (imsg_compose(ibuf, GOT_IMSG_BLOB, 0, 0, -1, &iblob, sizeof(iblob))
778 	    == -1)
779 		return got_error_from_errno();
780 
781 	return flush_imsg(ibuf);
782 }
783 
784 const struct got_error *
785 got_privsep_recv_blob(size_t *size, struct imsgbuf *ibuf)
786 {
787 	const struct got_error *err = NULL;
788 	struct imsg imsg;
789 	struct got_imsg_blob iblob;
790 	size_t datalen;
791 
792 	err = got_privsep_recv_imsg(&imsg, ibuf, 0);
793 	if (err)
794 		return err;
795 
796 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
797 
798 	switch (imsg.hdr.type) {
799 	case GOT_IMSG_ERROR:
800 		err = recv_imsg_error(&imsg, datalen);
801 		break;
802 	case GOT_IMSG_BLOB:
803 		if (datalen != sizeof(iblob))
804 			err = got_error(GOT_ERR_PRIVSEP_LEN);
805 		memcpy(&iblob, imsg.data, sizeof(iblob));
806 		*size = iblob.size;
807 		/* Data has been written to file descriptor. */
808 		break;
809 	default:
810 		err = got_error(GOT_ERR_PRIVSEP_MSG);
811 		break;
812 	}
813 
814 	imsg_free(&imsg);
815 
816 	return err;
817 }
818 
819 const struct got_error *
820 got_privsep_init_pack_child(struct imsgbuf *ibuf, struct got_pack *pack,
821     struct got_packidx *packidx)
822 {
823 	struct got_imsg_packidx ipackidx;
824 	struct got_imsg_pack ipack;
825 	int fd;
826 
827 	ipackidx.len = packidx->len;
828 	fd = dup(packidx->fd);
829 	if (fd == -1)
830 		return got_error_from_errno();
831 
832 	if (imsg_compose(ibuf, GOT_IMSG_PACKIDX, 0, 0, fd, &ipackidx,
833 	    sizeof(ipackidx)) == -1)
834 		return got_error_from_errno();
835 
836 	if (strlcpy(ipack.path_packfile, pack->path_packfile,
837 	    sizeof(ipack.path_packfile)) >= sizeof(ipack.path_packfile))
838 		return got_error(GOT_ERR_NO_SPACE);
839 	ipack.filesize = pack->filesize;
840 
841 	fd = dup(pack->fd);
842 	if (fd == -1)
843 		return got_error_from_errno();
844 
845 	if (imsg_compose(ibuf, GOT_IMSG_PACK, 0, 0, fd, &ipack, sizeof(ipack))
846 	    == -1)
847 		return got_error_from_errno();
848 
849 	return flush_imsg(ibuf);
850 }
851 
852 const struct got_error *
853 got_privsep_send_packed_obj_req(struct imsgbuf *ibuf, int idx)
854 {
855 	struct got_imsg_packed_object iobj;
856 
857 	iobj.idx = idx;
858 
859 	if (imsg_compose(ibuf, GOT_IMSG_PACKED_OBJECT_REQUEST, 0, 0, -1,
860 	    &iobj, sizeof(iobj)) == -1)
861 		return got_error_from_errno();
862 
863 	return flush_imsg(ibuf);
864 }