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Date:: Sun Nov 4 18:59:47 2018 UTC
Message:: properly flush imsg in send_commit_logmsg()
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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 	memcpy(&icommit.tm_author, &commit->tm_author,
418 	    sizeof(icommit.tm_author));
419 	icommit.committer_len = strlen(commit->committer);
420 	memcpy(&icommit.tm_committer, &commit->tm_committer,
421 	    sizeof(icommit.tm_committer));
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 	err = flush_imsg(ibuf);
450 	if (err)
451 		goto done;
452 
453 	err = send_commit_logmsg(ibuf, commit, logmsg_len);
454 done:
455 	free(buf);
456 	return err;
457 }
458 
459 const struct got_error *
460 got_privsep_recv_commit(struct got_commit_object **commit, struct imsgbuf *ibuf)
461 {
462 	const struct got_error *err = NULL;
463 	struct imsg imsg;
464 	struct got_imsg_commit_object icommit;
465 	size_t len, datalen;
466 	int i;
467 	const size_t min_datalen =
468 	    MIN(sizeof(struct got_imsg_error),
469 	    sizeof(struct got_imsg_commit_object));
470 	uint8_t *data;
471 
472 	*commit = NULL;
473 
474 	err = got_privsep_recv_imsg(&imsg, ibuf, min_datalen);
475 	if (err)
476 		return err;
477 
478 	data = imsg.data;
479 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
480 	len = 0;
481 
482 	switch (imsg.hdr.type) {
483 	case GOT_IMSG_ERROR:
484 		err = recv_imsg_error(&imsg, datalen);
485 		break;
486 	case GOT_IMSG_COMMIT:
487 		if (datalen < sizeof(icommit)) {
488 			err = got_error(GOT_ERR_PRIVSEP_LEN);
489 			break;
490 		}
491 
492 		memcpy(&icommit, data, sizeof(icommit));
493 		if (datalen != sizeof(icommit) + icommit.author_len +
494 		    icommit.committer_len +
495 		    icommit.nparents * SHA1_DIGEST_LENGTH) {
496 			err = got_error(GOT_ERR_PRIVSEP_LEN);
497 			break;
498 		}
499 		if (icommit.nparents < 0) {
500 			err = got_error(GOT_ERR_PRIVSEP_LEN);
501 			break;
502 		}
503 		len += sizeof(icommit);
504 
505 		*commit = got_object_commit_alloc_partial();
506 		if (*commit == NULL) {
507 			err = got_error_from_errno();
508 			break;
509 		}
510 
511 		memcpy((*commit)->tree_id->sha1, icommit.tree_id,
512 		    SHA1_DIGEST_LENGTH);
513 		memcpy(&(*commit)->tm_author, &icommit.tm_author,
514 		    sizeof((*commit)->tm_author));
515 		memcpy(&(*commit)->tm_committer, &icommit.tm_committer,
516 		    sizeof((*commit)->tm_committer));
517 
518 		if (icommit.author_len == 0) {
519 			(*commit)->author = strdup("");
520 			if ((*commit)->author == NULL) {
521 				err = got_error_from_errno();
522 				break;
523 			}
524 		} else {
525 			(*commit)->author = malloc(icommit.author_len + 1);
526 			if ((*commit)->author == NULL) {
527 				err = got_error_from_errno();
528 				break;
529 			}
530 			memcpy((*commit)->author, data + len,
531 			    icommit.author_len);
532 			(*commit)->author[icommit.author_len] = '\0';
533 		}
534 		len += icommit.author_len;
535 
536 		if (icommit.committer_len == 0) {
537 			(*commit)->committer = strdup("");
538 			if ((*commit)->committer == NULL) {
539 				err = got_error_from_errno();
540 				break;
541 			}
542 		} else {
543 			(*commit)->committer =
544 			    malloc(icommit.committer_len + 1);
545 			if ((*commit)->committer == NULL) {
546 				err = got_error_from_errno();
547 				break;
548 			}
549 			memcpy((*commit)->committer, data + len,
550 			    icommit.committer_len);
551 			(*commit)->committer[icommit.committer_len] = '\0';
552 		}
553 		len += icommit.committer_len;
554 
555 		if (icommit.logmsg_len == 0) {
556 			(*commit)->logmsg = strdup("");
557 			if ((*commit)->logmsg == NULL) {
558 				err = got_error_from_errno();
559 				break;
560 			}
561 		} else {
562 			size_t offset = 0, remain = icommit.logmsg_len;
563 
564 			(*commit)->logmsg = malloc(icommit.logmsg_len + 1);
565 			if ((*commit)->logmsg == NULL) {
566 				err = got_error_from_errno();
567 				break;
568 			}
569 			while (remain > 0) {
570 				struct imsg imsg_log;
571 				size_t n = MIN(MAX_IMSGSIZE - IMSG_HEADER_SIZE,
572 				    remain);
573 
574 				err = got_privsep_recv_imsg(&imsg_log, ibuf, n);
575 				if (err)
576 					return err;
577 
578 				if (imsg_log.hdr.type != GOT_IMSG_COMMIT_LOGMSG)
579 					return got_error(GOT_ERR_PRIVSEP_MSG);
580 
581 				memcpy((*commit)->logmsg + offset,
582 				    imsg_log.data, n);
583 				imsg_free(&imsg_log);
584 				offset += n;
585 				remain -= n;
586 			}
587 			(*commit)->logmsg[icommit.logmsg_len] = '\0';
588 		}
589 
590 		for (i = 0; i < icommit.nparents; i++) {
591 			struct got_object_qid *qid;
592 
593 			qid = calloc(1, sizeof(*qid));
594 			if (qid == NULL) {
595 				err = got_error_from_errno();
596 				break;
597 			}
598 			qid->id = calloc(1, sizeof(*qid->id));
599 			if (qid->id == NULL) {
600 				err = got_error_from_errno();
601 				free(qid);
602 				break;
603 			}
604 
605 			memcpy(qid->id, data + len + i * SHA1_DIGEST_LENGTH,
606 			    sizeof(*qid->id));
607 			SIMPLEQ_INSERT_TAIL(&(*commit)->parent_ids, qid, entry);
608 			(*commit)->nparents++;
609 		}
610 		break;
611 	default:
612 		err = got_error(GOT_ERR_PRIVSEP_MSG);
613 		break;
614 	}
615 
616 	imsg_free(&imsg);
617 
618 	return err;
619 }
620 
621 const struct got_error *
622 got_privsep_send_tree(struct imsgbuf *ibuf, struct got_tree_object *tree)
623 {
624 	const struct got_error *err = NULL;
625 	struct got_imsg_tree_object itree;
626 	struct got_tree_entry *te;
627 
628 	itree.nentries = tree->entries.nentries;
629 	if (imsg_compose(ibuf, GOT_IMSG_TREE, 0, 0, -1, &itree, sizeof(itree))
630 	    == -1)
631 		return got_error_from_errno();
632 
633 	err = flush_imsg(ibuf);
634 	if (err)
635 		return err;
636 
637 	SIMPLEQ_FOREACH(te, &tree->entries.head, entry) {
638 		struct got_imsg_tree_entry ite;
639 		uint8_t *buf = NULL;
640 		size_t len = sizeof(ite) + strlen(te->name);
641 
642 		if (len > MAX_IMSGSIZE)
643 			return got_error(GOT_ERR_NO_SPACE);
644 
645 		buf = malloc(len);
646 		if (buf == NULL)
647 			return got_error_from_errno();
648 
649 		memcpy(ite.id, te->id->sha1, sizeof(ite.id));
650 		ite.mode = te->mode;
651 		memcpy(buf, &ite, sizeof(ite));
652 		memcpy(buf + sizeof(ite), te->name, strlen(te->name));
653 
654 		if (imsg_compose(ibuf, GOT_IMSG_TREE_ENTRY, 0, 0, -1,
655 		    buf, len) == -1)
656 			err = got_error_from_errno();
657 		free(buf);
658 		if (err)
659 			return err;
660 
661 		err = flush_imsg(ibuf);
662 		if (err)
663 			return err;
664 	}
665 
666 	return NULL;
667 }
668 
669 const struct got_error *
670 got_privsep_recv_tree(struct got_tree_object **tree, struct imsgbuf *ibuf)
671 {
672 	const struct got_error *err = NULL;
673 	const size_t min_datalen =
674 	    MIN(sizeof(struct got_imsg_error),
675 	    sizeof(struct got_imsg_tree_object));
676 	struct got_imsg_tree_object itree = { 0 };
677 	int nentries = 0;
678 
679 	*tree = NULL;
680 get_more:
681 	err = read_imsg(ibuf);
682 	if (err)
683 		goto done;
684 
685 	while (1) {
686 		struct imsg imsg;
687 		size_t n;
688 		size_t datalen;
689 		struct got_imsg_tree_entry ite;
690 		struct got_tree_entry *te = NULL;
691 
692 		n = imsg_get(ibuf, &imsg);
693 		if (n == 0) {
694 			if (*tree && (*tree)->entries.nentries != nentries)
695 				goto get_more;
696 			break;
697 		}
698 
699 		if (imsg.hdr.len < IMSG_HEADER_SIZE + min_datalen)
700 			return got_error(GOT_ERR_PRIVSEP_LEN);
701 
702 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
703 
704 		switch (imsg.hdr.type) {
705 		case GOT_IMSG_ERROR:
706 			err = recv_imsg_error(&imsg, datalen);
707 			break;
708 		case GOT_IMSG_TREE:
709 			/* This message should only appear once. */
710 			if (*tree != NULL) {
711 				err = got_error(GOT_ERR_PRIVSEP_MSG);
712 				break;
713 			}
714 			if (datalen != sizeof(itree)) {
715 				err = got_error(GOT_ERR_PRIVSEP_LEN);
716 				break;
717 			}
718 			memcpy(&itree, imsg.data, sizeof(itree));
719 			*tree = calloc(1, sizeof(**tree));
720 			if (*tree == NULL) {
721 				err = got_error_from_errno();
722 				break;
723 			}
724 			(*tree)->entries.nentries = itree.nentries;
725 			SIMPLEQ_INIT(&(*tree)->entries.head);
726 			break;
727 		case GOT_IMSG_TREE_ENTRY:
728 			/* This message should be preceeded by GOT_IMSG_TREE. */
729 			if (*tree == NULL) {
730 				err = got_error(GOT_ERR_PRIVSEP_MSG);
731 				break;
732 			}
733 			if (datalen < sizeof(ite) || datalen > MAX_IMSGSIZE) {
734 				err = got_error(GOT_ERR_PRIVSEP_LEN);
735 				break;
736 			}
737 
738 			/* Remaining data contains the entry's name. */
739 			datalen -= sizeof(ite);
740 			memcpy(&ite, imsg.data, sizeof(ite));
741 			if (datalen == 0 || datalen > MAX_IMSGSIZE) {
742 				err = got_error(GOT_ERR_PRIVSEP_LEN);
743 				break;
744 			}
745 
746 			te = got_alloc_tree_entry_partial();
747 			if (te == NULL) {
748 				err = got_error_from_errno();
749 				break;
750 			}
751 			te->name = malloc(datalen + 1);
752 			if (te->name == NULL) {
753 				free(te);
754 				err = got_error_from_errno();
755 				break;
756 			}
757 			memcpy(te->name, imsg.data + sizeof(ite), datalen);
758 			te->name[datalen] = '\0';
759 
760 			memcpy(te->id->sha1, ite.id, SHA1_DIGEST_LENGTH);
761 			te->mode = ite.mode;
762 			SIMPLEQ_INSERT_TAIL(&(*tree)->entries.head, te, entry);
763 			nentries++;
764 			break;
765 		default:
766 			err = got_error(GOT_ERR_PRIVSEP_MSG);
767 			break;
768 		}
769 
770 		imsg_free(&imsg);
771 	}
772 done:
773 	if (*tree && (*tree)->entries.nentries != nentries) {
774 		if (err == NULL)
775 			err = got_error(GOT_ERR_PRIVSEP_LEN);
776 		got_object_tree_close(*tree);
777 		*tree = NULL;
778 	}
779 
780 	return err;
781 }
782 
783 const struct got_error *
784 got_privsep_send_blob(struct imsgbuf *ibuf, size_t size)
785 {
786 	struct got_imsg_blob iblob;
787 
788 	iblob.size = size;
789 	/* Data has already been written to file descriptor. */
790 
791 	if (imsg_compose(ibuf, GOT_IMSG_BLOB, 0, 0, -1, &iblob, sizeof(iblob))
792 	    == -1)
793 		return got_error_from_errno();
794 
795 	return flush_imsg(ibuf);
796 }
797 
798 const struct got_error *
799 got_privsep_recv_blob(size_t *size, struct imsgbuf *ibuf)
800 {
801 	const struct got_error *err = NULL;
802 	struct imsg imsg;
803 	struct got_imsg_blob iblob;
804 	size_t datalen;
805 
806 	err = got_privsep_recv_imsg(&imsg, ibuf, 0);
807 	if (err)
808 		return err;
809 
810 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
811 
812 	switch (imsg.hdr.type) {
813 	case GOT_IMSG_ERROR:
814 		err = recv_imsg_error(&imsg, datalen);
815 		break;
816 	case GOT_IMSG_BLOB:
817 		if (datalen != sizeof(iblob)) {
818 			err = got_error(GOT_ERR_PRIVSEP_LEN);
819 			break;
820 		}
821 		memcpy(&iblob, imsg.data, sizeof(iblob));
822 		*size = iblob.size;
823 		/* Data has been written to file descriptor. */
824 		break;
825 	default:
826 		err = got_error(GOT_ERR_PRIVSEP_MSG);
827 		break;
828 	}
829 
830 	imsg_free(&imsg);
831 
832 	return err;
833 }
834 
835 const struct got_error *
836 got_privsep_init_pack_child(struct imsgbuf *ibuf, struct got_pack *pack,
837     struct got_packidx *packidx)
838 {
839 	struct got_imsg_packidx ipackidx;
840 	struct got_imsg_pack ipack;
841 	int fd;
842 
843 	ipackidx.len = packidx->len;
844 	fd = dup(packidx->fd);
845 	if (fd == -1)
846 		return got_error_from_errno();
847 
848 	if (imsg_compose(ibuf, GOT_IMSG_PACKIDX, 0, 0, fd, &ipackidx,
849 	    sizeof(ipackidx)) == -1)
850 		return got_error_from_errno();
851 
852 	if (strlcpy(ipack.path_packfile, pack->path_packfile,
853 	    sizeof(ipack.path_packfile)) >= sizeof(ipack.path_packfile))
854 		return got_error(GOT_ERR_NO_SPACE);
855 	ipack.filesize = pack->filesize;
856 
857 	fd = dup(pack->fd);
858 	if (fd == -1)
859 		return got_error_from_errno();
860 
861 	if (imsg_compose(ibuf, GOT_IMSG_PACK, 0, 0, fd, &ipack, sizeof(ipack))
862 	    == -1)
863 		return got_error_from_errno();
864 
865 	return flush_imsg(ibuf);
866 }
867 
868 const struct got_error *
869 got_privsep_send_packed_obj_req(struct imsgbuf *ibuf, int idx,
870     struct got_object_id *id)
871 {
872 	struct got_imsg_packed_object iobj;
873 
874 	iobj.idx = idx;
875 	memcpy(iobj.id, id->sha1, sizeof(iobj.id));
876 
877 	if (imsg_compose(ibuf, GOT_IMSG_PACKED_OBJECT_REQUEST, 0, 0, -1,
878 	    &iobj, sizeof(iobj)) == -1)
879 		return got_error_from_errno();
880 
881 	return flush_imsg(ibuf);
882 }