1 /*
2  * Copyright (c) 2018, 2019, 2020 Stefan Sperling <stsp@openbsd.org>
3  * Copyright (c) 2020 Ori Bernstein <ori@openbsd.org>
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 #include <sys/types.h>
19 #include <sys/queue.h>
20 #include <sys/uio.h>
21 #include <sys/syslimits.h>
22 #include <sys/wait.h>
23 
24 #include <ctype.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <string.h>
28 #include <errno.h>
29 #include <stdint.h>
30 #include <poll.h>
31 #include <imsg.h>
32 #include <sha1.h>
33 #include <zlib.h>
34 #include <time.h>
35 
36 #include "got_object.h"
37 #include "got_error.h"
38 #include "got_path.h"
39 #include "got_repository.h"
40 
41 #include "got_lib_sha1.h"
42 #include "got_lib_delta.h"
43 #include "got_lib_inflate.h"
44 #include "got_lib_object.h"
45 #include "got_lib_object_parse.h"
46 #include "got_lib_privsep.h"
47 #include "got_lib_pack.h"
48 
49 #ifndef MIN
50 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
51 #endif
52 
53 #ifndef nitems
54 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
55 #endif
56 
57 static const struct got_error *
58 poll_fd(int fd, int events, int timeout)
59 {
60 	struct pollfd pfd[1];
61 	int n;
62 
63 	pfd[0].fd = fd;
64 	pfd[0].events = events;
65 
66 	n = poll(pfd, 1, timeout);
67 	if (n == -1)
68 		return got_error_from_errno("poll");
69 	if (n == 0)
70 		return got_error(GOT_ERR_TIMEOUT);
71 	if (pfd[0].revents & (POLLERR | POLLNVAL))
72 		return got_error_from_errno("poll error");
73 	if (pfd[0].revents & (events | POLLHUP))
74 		return NULL;
75 
76 	return got_error(GOT_ERR_INTERRUPT);
77 }
78 
79 static const struct got_error *
80 read_imsg(struct imsgbuf *ibuf)
81 {
82 	const struct got_error *err;
83 	size_t n;
84 
85 	err = poll_fd(ibuf->fd, POLLIN, INFTIM);
86 	if (err)
87 		return err;
88 
89 	n = imsg_read(ibuf);
90 	if (n == -1) {
91 		if (errno == EAGAIN) /* Could be a file-descriptor leak. */
92 			return got_error(GOT_ERR_PRIVSEP_NO_FD);
93 		return got_error(GOT_ERR_PRIVSEP_READ);
94 	}
95 	if (n == 0)
96 		return got_error(GOT_ERR_PRIVSEP_PIPE);
97 
98 	return NULL;
99 }
100 
101 const struct got_error *
102 got_privsep_wait_for_child(pid_t pid)
103 {
104 	int child_status;
105 
106 	if (waitpid(pid, &child_status, 0) == -1)
107 		return got_error_from_errno("waitpid");
108 
109 	if (!WIFEXITED(child_status))
110 		return got_error(GOT_ERR_PRIVSEP_DIED);
111 
112 	if (WEXITSTATUS(child_status) != 0)
113 		return got_error(GOT_ERR_PRIVSEP_EXIT);
114 
115 	return NULL;
116 }
117 
118 static const struct got_error *
119 recv_imsg_error(struct imsg *imsg, size_t datalen)
120 {
121 	struct got_imsg_error *ierr;
122 
123 	if (datalen != sizeof(*ierr))
124 		return got_error(GOT_ERR_PRIVSEP_LEN);
125 
126 	ierr = imsg->data;
127 	if (ierr->code == GOT_ERR_ERRNO) {
128 		static struct got_error serr;
129 		serr.code = GOT_ERR_ERRNO;
130 		serr.msg = strerror(ierr->errno_code);
131 		return &serr;
132 	}
133 
134 	return got_error(ierr->code);
135 }
136 
137 const struct got_error *
138 got_privsep_recv_imsg(struct imsg *imsg, struct imsgbuf *ibuf,
139     size_t min_datalen)
140 {
141 	const struct got_error *err;
142 	ssize_t n;
143 
144 	n = imsg_get(ibuf, imsg);
145 	if (n == -1)
146 		return got_error_from_errno("imsg_get");
147 
148 	while (n == 0) {
149 		err = read_imsg(ibuf);
150 		if (err)
151 			return err;
152 		n = imsg_get(ibuf, imsg);
153 		if (n == -1)
154 			return got_error_from_errno("imsg_get");
155 	}
156 
157 	if (imsg->hdr.len < IMSG_HEADER_SIZE + min_datalen)
158 		return got_error(GOT_ERR_PRIVSEP_LEN);
159 
160 	if (imsg->hdr.type == GOT_IMSG_ERROR) {
161 		size_t datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
162 		return recv_imsg_error(imsg, datalen);
163 	}
164 
165 	return NULL;
166 }
167 
168 /* Attempt to send an error in an imsg. Complain on stderr as a last resort. */
169 void
170 got_privsep_send_error(struct imsgbuf *ibuf, const struct got_error *err)
171 {
172 	const struct got_error *poll_err;
173 	struct got_imsg_error ierr;
174 	int ret;
175 
176 	ierr.code = err->code;
177 	if (err->code == GOT_ERR_ERRNO)
178 		ierr.errno_code = errno;
179 	else
180 		ierr.errno_code = 0;
181 	ret = imsg_compose(ibuf, GOT_IMSG_ERROR, 0, 0, -1, &ierr, sizeof(ierr));
182 	if (ret == -1) {
183 		fprintf(stderr, "%s: error %d \"%s\": imsg_compose: %s\n",
184 		    getprogname(), err->code, err->msg, strerror(errno));
185 		return;
186 	}
187 
188 	poll_err = poll_fd(ibuf->fd, POLLOUT, INFTIM);
189 	if (poll_err) {
190 		fprintf(stderr, "%s: error %d \"%s\": poll: %s\n",
191 		    getprogname(), err->code, err->msg, poll_err->msg);
192 		return;
193 	}
194 
195 	ret = imsg_flush(ibuf);
196 	if (ret == -1) {
197 		fprintf(stderr, "%s: error %d \"%s\": imsg_flush: %s\n",
198 		    getprogname(), err->code, err->msg, strerror(errno));
199 		return;
200 	}
201 }
202 
203 static const struct got_error *
204 flush_imsg(struct imsgbuf *ibuf)
205 {
206 	const struct got_error *err;
207 
208 	err = poll_fd(ibuf->fd, POLLOUT, INFTIM);
209 	if (err)
210 		return err;
211 
212 	if (imsg_flush(ibuf) == -1)
213 		return got_error_from_errno("imsg_flush");
214 
215 	return NULL;
216 }
217 
218 const struct got_error *
219 got_privsep_send_stop(int fd)
220 {
221 	const struct got_error *err = NULL;
222 	struct imsgbuf ibuf;
223 
224 	imsg_init(&ibuf, fd);
225 
226 	if (imsg_compose(&ibuf, GOT_IMSG_STOP, 0, 0, -1, NULL, 0) == -1)
227 		return got_error_from_errno("imsg_compose STOP");
228 
229 	err = flush_imsg(&ibuf);
230 	imsg_clear(&ibuf);
231 	return err;
232 }
233 
234 const struct got_error *
235 got_privsep_send_obj_req(struct imsgbuf *ibuf, int fd)
236 {
237 	if (imsg_compose(ibuf, GOT_IMSG_OBJECT_REQUEST, 0, 0, fd, NULL, 0)
238 	    == -1)
239 		return got_error_from_errno("imsg_compose OBJECT_REQUEST");
240 
241 	return flush_imsg(ibuf);
242 }
243 
244 const struct got_error *
245 got_privsep_send_commit_req(struct imsgbuf *ibuf, int fd,
246     struct got_object_id *id, int pack_idx)
247 {
248 	const struct got_error *err = NULL;
249 	struct got_imsg_packed_object iobj, *iobjp;
250 	size_t len;
251 
252 	if (id) { /* commit is packed */
253 		iobj.idx = pack_idx;
254 		memcpy(iobj.id, id->sha1, sizeof(iobj.id));
255 		iobjp = &iobj;
256 		len = sizeof(iobj);
257 	} else {
258 		iobjp = NULL;
259 		len = 0;
260 	}
261 
262 	if (imsg_compose(ibuf, GOT_IMSG_COMMIT_REQUEST, 0, 0, fd, iobjp, len)
263 	    == -1) {
264 		err = got_error_from_errno("imsg_compose COMMIT_REQUEST");
265 		close(fd);
266 		return err;
267 	}
268 
269 	return flush_imsg(ibuf);
270 }
271 
272 const struct got_error *
273 got_privsep_send_tree_req(struct imsgbuf *ibuf, int fd,
274     struct got_object_id *id, int pack_idx)
275 {
276 	const struct got_error *err = NULL;
277 	struct ibuf *wbuf;
278 	size_t len = id ? sizeof(struct got_imsg_packed_object) : 0;
279 
280 	wbuf = imsg_create(ibuf, GOT_IMSG_TREE_REQUEST, 0, 0, len);
281 	if (wbuf == NULL)
282 		return got_error_from_errno("imsg_create TREE_REQUEST");
283 
284 	if (id) { /* tree is packed */
285 		if (imsg_add(wbuf, id->sha1, SHA1_DIGEST_LENGTH) == -1) {
286 			err = got_error_from_errno("imsg_add TREE_ENTRY");
287 			ibuf_free(wbuf);
288 			return err;
289 		}
290 
291 		if (imsg_add(wbuf, &pack_idx, sizeof(pack_idx)) == -1) {
292 			err = got_error_from_errno("imsg_add TREE_ENTRY");
293 			ibuf_free(wbuf);
294 			return err;
295 		}
296 	}
297 
298 	wbuf->fd = fd;
299 	imsg_close(ibuf, wbuf);
300 
301 	return flush_imsg(ibuf);
302 }
303 
304 const struct got_error *
305 got_privsep_send_tag_req(struct imsgbuf *ibuf, int fd,
306     struct got_object_id *id, int pack_idx)
307 {
308 	struct got_imsg_packed_object iobj, *iobjp;
309 	size_t len;
310 
311 	if (id) { /* tag is packed */
312 		iobj.idx = pack_idx;
313 		memcpy(iobj.id, id->sha1, sizeof(iobj.id));
314 		iobjp = &iobj;
315 		len = sizeof(iobj);
316 	} else {
317 		iobjp = NULL;
318 		len = 0;
319 	}
320 
321 	if (imsg_compose(ibuf, GOT_IMSG_TAG_REQUEST, 0, 0, fd, iobjp, len)
322 	    == -1)
323 		return got_error_from_errno("imsg_compose TAG_REQUEST");
324 
325 	return flush_imsg(ibuf);
326 }
327 
328 const struct got_error *
329 got_privsep_send_blob_req(struct imsgbuf *ibuf, int infd,
330     struct got_object_id *id, int pack_idx)
331 {
332 	const struct got_error *err = NULL;
333 	struct got_imsg_packed_object iobj, *iobjp;
334 	size_t len;
335 
336 	if (id) { /* blob is packed */
337 		iobj.idx = pack_idx;
338 		memcpy(iobj.id, id->sha1, sizeof(iobj.id));
339 		iobjp = &iobj;
340 		len = sizeof(iobj);
341 	} else {
342 		iobjp = NULL;
343 		len = 0;
344 	}
345 
346 	if (imsg_compose(ibuf, GOT_IMSG_BLOB_REQUEST, 0, 0, infd, iobjp, len)
347 	    == -1) {
348 		err = got_error_from_errno("imsg_compose BLOB_REQUEST");
349 		close(infd);
350 		return err;
351 	}
352 
353 	return flush_imsg(ibuf);
354 }
355 
356 const struct got_error *
357 got_privsep_send_blob_outfd(struct imsgbuf *ibuf, int outfd)
358 {
359 	const struct got_error *err = NULL;
360 
361 	if (imsg_compose(ibuf, GOT_IMSG_BLOB_OUTFD, 0, 0, outfd, NULL, 0)
362 	    == -1) {
363 		err = got_error_from_errno("imsg_compose BLOB_OUTFD");
364 		close(outfd);
365 		return err;
366 	}
367 
368 	return flush_imsg(ibuf);
369 }
370 
371 static const struct got_error *
372 send_fd(struct imsgbuf *ibuf, int imsg_code, int fd)
373 {
374 	const struct got_error *err = NULL;
375 
376 	if (imsg_compose(ibuf, imsg_code, 0, 0, fd, NULL, 0) == -1) {
377 		err = got_error_from_errno("imsg_compose TMPFD");
378 		close(fd);
379 		return err;
380 	}
381 
382 	return flush_imsg(ibuf);
383 }
384 
385 const struct got_error *
386 got_privsep_send_tmpfd(struct imsgbuf *ibuf, int fd)
387 {
388 	return send_fd(ibuf, GOT_IMSG_TMPFD, fd);
389 }
390 
391 const struct got_error *
392 got_privsep_send_obj(struct imsgbuf *ibuf, struct got_object *obj)
393 {
394 	struct got_imsg_object iobj;
395 
396 	memcpy(iobj.id, obj->id.sha1, sizeof(iobj.id));
397 	iobj.type = obj->type;
398 	iobj.flags = obj->flags;
399 	iobj.hdrlen = obj->hdrlen;
400 	iobj.size = obj->size;
401 	if (iobj.flags & GOT_OBJ_FLAG_PACKED) {
402 		iobj.pack_offset = obj->pack_offset;
403 		iobj.pack_idx = obj->pack_idx;
404 	}
405 
406 	if (imsg_compose(ibuf, GOT_IMSG_OBJECT, 0, 0, -1, &iobj, sizeof(iobj))
407 	    == -1)
408 		return got_error_from_errno("imsg_compose OBJECT");
409 
410 	return flush_imsg(ibuf);
411 }
412 
413 const struct got_error *
414 got_privsep_send_fetch_req(struct imsgbuf *ibuf, int fd,
415    struct got_pathlist_head *have_refs, int fetch_all_branches)
416 {
417 	const struct got_error *err = NULL;
418 	struct ibuf *wbuf;
419 	size_t len, n_have_refs = 0;
420 	struct got_pathlist_entry *pe;
421 
422 	len = sizeof(struct got_imsg_fetch_request);
423 	TAILQ_FOREACH(pe, have_refs, entry) {
424 		len += sizeof(struct got_imsg_fetch_have_ref) + pe->path_len;
425 		n_have_refs++;
426 	}
427 	if (len >= MAX_IMSGSIZE - IMSG_HEADER_SIZE) {
428 		close(fd);
429 		return got_error(GOT_ERR_NO_SPACE);
430 	}
431 
432 	wbuf = imsg_create(ibuf, GOT_IMSG_FETCH_REQUEST, 0, 0, len);
433 	if (wbuf == NULL) {
434 		close(fd);
435 		return got_error_from_errno("imsg_create FETCH_REQUEST");
436 	}
437 
438 	/* Keep in sync with struct got_imsg_fetch_request definition! */
439 	if (imsg_add(wbuf, &fetch_all_branches, sizeof(fetch_all_branches))
440 	    == -1) {
441 		err = got_error_from_errno("imsg_add FETCH_REQUEST");
442 		ibuf_free(wbuf);
443 		close(fd);
444 		return err;
445 	}
446 	if (imsg_add(wbuf, &n_have_refs, sizeof(n_have_refs)) == -1) {
447 		err = got_error_from_errno("imsg_add FETCH_REQUEST");
448 		ibuf_free(wbuf);
449 		close(fd);
450 		return err;
451 	}
452 
453 	TAILQ_FOREACH(pe, have_refs, entry) {
454 		const char *name = pe->path;
455 		size_t name_len = pe->path_len;
456 		struct got_object_id *id = pe->data;
457 
458 		/* Keep in sync with struct got_imsg_fetch_have_ref! */
459 		if (imsg_add(wbuf, id->sha1, sizeof(id->sha1)) == -1) {
460 			err = got_error_from_errno("imsg_add FETCH_REQUEST");
461 			ibuf_free(wbuf);
462 			close(fd);
463 			return err;
464 		}
465 		if (imsg_add(wbuf, &name_len, sizeof(name_len)) == -1) {
466 			err = got_error_from_errno("imsg_add FETCH_REQUEST");
467 			ibuf_free(wbuf);
468 			close(fd);
469 			return err;
470 		}
471 		if (imsg_add(wbuf, name, name_len) == -1) {
472 			err = got_error_from_errno("imsg_add FETCH_REQUEST");
473 			ibuf_free(wbuf);
474 			close(fd);
475 			return err;
476 		}
477 	}
478 
479 	wbuf->fd = fd;
480 	imsg_close(ibuf, wbuf);
481 	return flush_imsg(ibuf);
482 }
483 
484 const struct got_error *
485 got_privsep_send_fetch_outfd(struct imsgbuf *ibuf, int fd)
486 {
487 	return send_fd(ibuf, GOT_IMSG_FETCH_OUTFD, fd);
488 }
489 
490 
491 const struct got_error *
492 got_privsep_send_fetch_symrefs(struct imsgbuf *ibuf,
493     struct got_pathlist_head *symrefs)
494 {
495 	const struct got_error *err = NULL;
496 	struct ibuf *wbuf;
497 	size_t len, nsymrefs = 0;
498 	struct got_pathlist_entry *pe;
499 
500 	len = sizeof(struct got_imsg_fetch_symrefs);
501 	TAILQ_FOREACH(pe, symrefs, entry) {
502 		const char *target = pe->data;
503 		len += sizeof(struct got_imsg_fetch_symref) +
504 		    pe->path_len + strlen(target);
505 		nsymrefs++;
506 	}
507 
508 	if (len >= MAX_IMSGSIZE - IMSG_HEADER_SIZE)
509 		return got_error(GOT_ERR_NO_SPACE);
510 
511 	wbuf = imsg_create(ibuf, GOT_IMSG_FETCH_SYMREFS, 0, 0, len);
512 	if (wbuf == NULL)
513 		return got_error_from_errno("imsg_create FETCH_SYMREFS");
514 
515 	/* Keep in sync with struct got_imsg_fetch_symrefs definition! */
516 	if (imsg_add(wbuf, &nsymrefs, sizeof(nsymrefs)) == -1) {
517 		err = got_error_from_errno("imsg_add FETCH_SYMREFS");
518 		ibuf_free(wbuf);
519 		return err;
520 	}
521 
522 	TAILQ_FOREACH(pe, symrefs, entry) {
523 		const char *name = pe->path;
524 		size_t name_len = pe->path_len;
525 		const char *target = pe->data;
526 		size_t target_len = strlen(target);
527 
528 		/* Keep in sync with struct got_imsg_fetch_symref definition! */
529 		if (imsg_add(wbuf, &name_len, sizeof(name_len)) == -1) {
530 			err = got_error_from_errno("imsg_add FETCH_SYMREFS");
531 			ibuf_free(wbuf);
532 			return err;
533 		}
534 		if (imsg_add(wbuf, &target_len, sizeof(target_len)) == -1) {
535 			err = got_error_from_errno("imsg_add FETCH_SYMREFS");
536 			ibuf_free(wbuf);
537 			return err;
538 		}
539 		if (imsg_add(wbuf, name, name_len) == -1) {
540 			err = got_error_from_errno("imsg_add FETCH_SYMREFS");
541 			ibuf_free(wbuf);
542 			return err;
543 		}
544 		if (imsg_add(wbuf, target, target_len) == -1) {
545 			err = got_error_from_errno("imsg_add FETCH_SYMREFS");
546 			ibuf_free(wbuf);
547 			return err;
548 		}
549 	}
550 
551 	wbuf->fd = -1;
552 	imsg_close(ibuf, wbuf);
553 	return flush_imsg(ibuf);
554 }
555 
556 const struct got_error *
557 got_privsep_send_fetch_ref(struct imsgbuf *ibuf,
558     struct got_object_id *refid, const char *refname)
559 {
560 	const struct got_error *err = NULL;
561 	struct ibuf *wbuf;
562 	size_t len, reflen = strlen(refname);
563 
564 	len = sizeof(struct got_imsg_fetch_ref) + reflen;
565 	if (len >= MAX_IMSGSIZE - IMSG_HEADER_SIZE)
566 		return got_error(GOT_ERR_NO_SPACE);
567 
568 	wbuf = imsg_create(ibuf, GOT_IMSG_FETCH_REF, 0, 0, len);
569 	if (wbuf == NULL)
570 		return got_error_from_errno("imsg_create FETCH_REF");
571 
572 	/* Keep in sync with struct got_imsg_fetch_ref definition! */
573 	if (imsg_add(wbuf, refid->sha1, SHA1_DIGEST_LENGTH) == -1) {
574 		err = got_error_from_errno("imsg_add FETCH_REF");
575 		ibuf_free(wbuf);
576 		return err;
577 	}
578 	if (imsg_add(wbuf, refname, reflen) == -1) {
579 		err = got_error_from_errno("imsg_add FETCH_REF");
580 		ibuf_free(wbuf);
581 		return err;
582 	}
583 
584 	wbuf->fd = -1;
585 	imsg_close(ibuf, wbuf);
586 	return flush_imsg(ibuf);
587 }
588 
589 const struct got_error *
590 got_privsep_send_fetch_server_progress(struct imsgbuf *ibuf, const char *msg,
591     size_t msglen)
592 {
593 	if (msglen > MAX_IMSGSIZE - IMSG_HEADER_SIZE)
594 		return got_error(GOT_ERR_NO_SPACE);
595 
596 	if (msglen == 0)
597 		return NULL;
598 
599 	if (imsg_compose(ibuf, GOT_IMSG_FETCH_SERVER_PROGRESS, 0, 0, -1,
600 	    msg, msglen) == -1)
601 		return got_error_from_errno(
602 		    "imsg_compose FETCH_SERVER_PROGRESS");
603 
604 	return flush_imsg(ibuf);
605 }
606 
607 const struct got_error *
608 got_privsep_send_fetch_download_progress(struct imsgbuf *ibuf, off_t bytes)
609 {
610 	if (imsg_compose(ibuf, GOT_IMSG_FETCH_DOWNLOAD_PROGRESS, 0, 0, -1,
611 	    &bytes, sizeof(bytes)) == -1)
612 		return got_error_from_errno(
613 		    "imsg_compose FETCH_DOWNLOAD_PROGRESS");
614 
615 	return flush_imsg(ibuf);
616 }
617 
618 const struct got_error *
619 got_privsep_send_fetch_done(struct imsgbuf *ibuf, struct got_object_id hash)
620 {
621 	if (imsg_compose(ibuf, GOT_IMSG_FETCH_DONE, 0, 0, -1,
622 	    hash.sha1, SHA1_DIGEST_LENGTH) == -1)
623 		return got_error_from_errno("imsg_compose FETCH");
624 	return flush_imsg(ibuf);
625 }
626 
627 
628 const struct got_error *
629 got_privsep_recv_fetch_progress(int *done, struct got_object_id **id,
630     char **refname, struct got_pathlist_head *symrefs, char **server_progress,
631     off_t *packfile_size, struct imsgbuf *ibuf)
632 {
633 	const struct got_error *err = NULL;
634 	struct imsg imsg;
635 	size_t datalen;
636 	struct got_imsg_fetch_symrefs *isymrefs = NULL;
637 	size_t n, remain;
638 	off_t off;
639 	int i;
640 
641 	*done = 0;
642 	*id = NULL;
643 	*refname = NULL;
644 	*server_progress = NULL;
645 	*packfile_size = 0;
646 
647 	err = got_privsep_recv_imsg(&imsg, ibuf, 0);
648 	if (err)
649 		return err;
650 
651 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
652 	switch (imsg.hdr.type) {
653 	case GOT_IMSG_ERROR:
654 		if (datalen < sizeof(struct got_imsg_error)) {
655 			err = got_error(GOT_ERR_PRIVSEP_LEN);
656 			break;
657 		}
658 		err = recv_imsg_error(&imsg, datalen);
659 		break;
660 	case GOT_IMSG_FETCH_SYMREFS:
661 		if (datalen < sizeof(*isymrefs)) {
662 			err = got_error(GOT_ERR_PRIVSEP_LEN);
663 			break;
664 		}
665 		if (isymrefs != NULL) {
666 			err = got_error(GOT_ERR_PRIVSEP_MSG);
667 			break;
668 		}
669 		isymrefs = (struct got_imsg_fetch_symrefs *)imsg.data;
670 		off = sizeof(*isymrefs);
671 		remain = datalen - off;
672 		for (n = 0; n < isymrefs->nsymrefs; n++) {
673 			struct got_imsg_fetch_symref *s;
674 			char *name, *target;
675 			if (remain < sizeof(struct got_imsg_fetch_symref)) {
676 				err = got_error(GOT_ERR_PRIVSEP_LEN);
677 				goto done;
678 			}
679 			s = (struct got_imsg_fetch_symref *)(imsg.data + off);
680 			off += sizeof(*s);
681 			remain -= sizeof(*s);
682 			if (remain < s->name_len) {
683 				err = got_error(GOT_ERR_PRIVSEP_LEN);
684 				goto done;
685 			}
686 			name = strndup(imsg.data + off, s->name_len);
687 			if (name == NULL) {
688 				err = got_error_from_errno("strndup");
689 				goto done;
690 			}
691 			off += s->name_len;
692 			remain -= s->name_len;
693 			if (remain < s->target_len) {
694 				err = got_error(GOT_ERR_PRIVSEP_LEN);
695 				free(name);
696 				goto done;
697 			}
698 			target = strndup(imsg.data + off, s->target_len);
699 			if (target == NULL) {
700 				err = got_error_from_errno("strndup");
701 				free(name);
702 				goto done;
703 			}
704 			off += s->target_len;
705 			remain -= s->target_len;
706 			err = got_pathlist_append(symrefs, name, target);
707 			if (err) {
708 				free(name);
709 				free(target);
710 				goto done;
711 			}
712 		}
713 		break;
714 	case GOT_IMSG_FETCH_REF:
715 		if (datalen <= SHA1_DIGEST_LENGTH) {
716 			err = got_error(GOT_ERR_PRIVSEP_MSG);
717 			break;
718 		}
719 		*id = malloc(sizeof(**id));
720 		if (*id == NULL) {
721 			err = got_error_from_errno("malloc");
722 			break;
723 		}
724 		memcpy((*id)->sha1, imsg.data, SHA1_DIGEST_LENGTH);
725 		*refname = strndup(imsg.data + SHA1_DIGEST_LENGTH,
726 		    datalen - SHA1_DIGEST_LENGTH);
727 		if (*refname == NULL) {
728 			err = got_error_from_errno("strndup");
729 			break;
730 		}
731 		break;
732 	case GOT_IMSG_FETCH_SERVER_PROGRESS:
733 		if (datalen == 0) {
734 			err = got_error(GOT_ERR_PRIVSEP_LEN);
735 			break;
736 		}
737 		*server_progress = strndup(imsg.data, datalen);
738 		if (*server_progress == NULL) {
739 			err = got_error_from_errno("strndup");
740 			break;
741 		}
742 		for (i = 0; i < datalen; i++) {
743 			if (!isprint((unsigned char)(*server_progress)[i]) &&
744 			    !isspace((unsigned char)(*server_progress)[i])) {
745 				err = got_error(GOT_ERR_PRIVSEP_MSG);
746 				free(*server_progress);
747 				*server_progress = NULL;
748 				goto done;
749 			}
750 		}
751 		break;
752 	case GOT_IMSG_FETCH_DOWNLOAD_PROGRESS:
753 		if (datalen < sizeof(*packfile_size)) {
754 			err = got_error(GOT_ERR_PRIVSEP_MSG);
755 			break;
756 		}
757 		memcpy(packfile_size, imsg.data, sizeof(*packfile_size));
758 		break;
759 	case GOT_IMSG_FETCH_DONE:
760 		*id = malloc(sizeof(**id));
761 		if (*id == NULL) {
762 			err = got_error_from_errno("malloc");
763 			break;
764 		}
765 		if (datalen != SHA1_DIGEST_LENGTH) {
766 			err = got_error(GOT_ERR_PRIVSEP_MSG);
767 			break;
768 		}
769 		memcpy((*id)->sha1, imsg.data, SHA1_DIGEST_LENGTH);
770 		*done = 1;
771 		break;
772 	default:
773 		err = got_error(GOT_ERR_PRIVSEP_MSG);
774 		break;
775 	}
776 done:
777 	if (err) {
778 		free(*id);
779 		*id = NULL;
780 		free(*refname);
781 		*refname = NULL;
782 	}
783 	imsg_free(&imsg);
784 	return err;
785 }
786 
787 const struct got_error *
788 got_privsep_send_index_pack_req(struct imsgbuf *ibuf, uint8_t *pack_hash,
789     int fd)
790 {
791 	const struct got_error *err = NULL;
792 
793 	/* Keep in sync with struct got_imsg_index_pack_request */
794 	if (imsg_compose(ibuf, GOT_IMSG_IDXPACK_REQUEST, 0, 0, fd,
795 	    pack_hash, SHA1_DIGEST_LENGTH) == -1) {
796 		err = got_error_from_errno("imsg_compose INDEX_REQUEST");
797 		close(fd);
798 		return err;
799 	}
800 	return flush_imsg(ibuf);
801 }
802 
803 const struct got_error *
804 got_privsep_send_index_pack_outfd(struct imsgbuf *ibuf, int fd)
805 {
806 	return send_fd(ibuf, GOT_IMSG_IDXPACK_OUTFD, fd);
807 }
808 
809 const struct got_error *
810 got_privsep_send_index_pack_progress(struct imsgbuf *ibuf, int nobj_total,
811     int nobj_indexed, int nobj_loose, int nobj_resolved)
812 {
813 	struct got_imsg_index_pack_progress iprogress;
814 
815 	iprogress.nobj_total = nobj_total;
816 	iprogress.nobj_indexed = nobj_indexed;
817 	iprogress.nobj_loose = nobj_loose;
818 	iprogress.nobj_resolved = nobj_resolved;
819 
820 	if (imsg_compose(ibuf, GOT_IMSG_IDXPACK_PROGRESS, 0, 0, -1,
821 	    &iprogress, sizeof(iprogress)) == -1)
822 		return got_error_from_errno("imsg_compose IDXPACK_PROGRESS");
823 
824 	return flush_imsg(ibuf);
825 }
826 
827 const struct got_error *
828 got_privsep_send_index_pack_done(struct imsgbuf *ibuf)
829 {
830 	if (imsg_compose(ibuf, GOT_IMSG_IDXPACK_DONE, 0, 0, -1, NULL, 0) == -1)
831 		return got_error_from_errno("imsg_compose FETCH");
832 	return flush_imsg(ibuf);
833 }
834 
835 const struct got_error *
836 got_privsep_recv_index_progress(int *done, int *nobj_total,
837     int *nobj_indexed, int *nobj_loose, int *nobj_resolved,
838     struct imsgbuf *ibuf)
839 {
840 	const struct got_error *err = NULL;
841 	struct imsg imsg;
842 	struct got_imsg_index_pack_progress *iprogress;
843 	size_t datalen;
844 
845 	*done = 0;
846 	*nobj_total = 0;
847 	*nobj_indexed = 0;
848 	*nobj_resolved = 0;
849 
850 	err = got_privsep_recv_imsg(&imsg, ibuf, 0);
851 	if (err)
852 		return err;
853 
854 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
855 	switch (imsg.hdr.type) {
856 	case GOT_IMSG_ERROR:
857 		if (datalen < sizeof(struct got_imsg_error)) {
858 			err = got_error(GOT_ERR_PRIVSEP_LEN);
859 			break;
860 		}
861 		err = recv_imsg_error(&imsg, datalen);
862 		break;
863 	case GOT_IMSG_IDXPACK_PROGRESS:
864 		if (datalen < sizeof(*iprogress)) {
865 			err = got_error(GOT_ERR_PRIVSEP_LEN);
866 			break;
867 		}
868 		iprogress = (struct got_imsg_index_pack_progress *)imsg.data;
869 		*nobj_total = iprogress->nobj_total;
870 		*nobj_indexed = iprogress->nobj_indexed;
871 		*nobj_loose = iprogress->nobj_loose;
872 		*nobj_resolved = iprogress->nobj_resolved;
873 		break;
874 	case GOT_IMSG_IDXPACK_DONE:
875 		if (datalen != 0) {
876 			err = got_error(GOT_ERR_PRIVSEP_LEN);
877 			break;
878 		}
879 		*done = 1;
880 		break;
881 	default:
882 		err = got_error(GOT_ERR_PRIVSEP_MSG);
883 		break;
884 	}
885 
886 	imsg_free(&imsg);
887 	return err;
888 }
889 
890 const struct got_error *
891 got_privsep_get_imsg_obj(struct got_object **obj, struct imsg *imsg,
892     struct imsgbuf *ibuf)
893 {
894 	const struct got_error *err = NULL;
895 	struct got_imsg_object *iobj;
896 	size_t datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
897 
898 	if (datalen != sizeof(*iobj))
899 		return got_error(GOT_ERR_PRIVSEP_LEN);
900 	iobj = imsg->data;
901 
902 	*obj = calloc(1, sizeof(**obj));
903 	if (*obj == NULL)
904 		return got_error_from_errno("calloc");
905 
906 	memcpy((*obj)->id.sha1, iobj->id, SHA1_DIGEST_LENGTH);
907 	(*obj)->type = iobj->type;
908 	(*obj)->flags = iobj->flags;
909 	(*obj)->hdrlen = iobj->hdrlen;
910 	(*obj)->size = iobj->size;
911 	/* path_packfile is handled by caller */
912 	if (iobj->flags & GOT_OBJ_FLAG_PACKED) {
913 		(*obj)->pack_offset = iobj->pack_offset;
914 		(*obj)->pack_idx = iobj->pack_idx;
915 	}
916 
917 	return err;
918 }
919 
920 const struct got_error *
921 got_privsep_recv_obj(struct got_object **obj, struct imsgbuf *ibuf)
922 {
923 	const struct got_error *err = NULL;
924 	struct imsg imsg;
925 	const size_t min_datalen =
926 	    MIN(sizeof(struct got_imsg_error), sizeof(struct got_imsg_object));
927 
928 	*obj = NULL;
929 
930 	err = got_privsep_recv_imsg(&imsg, ibuf, min_datalen);
931 	if (err)
932 		return err;
933 
934 	switch (imsg.hdr.type) {
935 	case GOT_IMSG_OBJECT:
936 		err = got_privsep_get_imsg_obj(obj, &imsg, ibuf);
937 		break;
938 	default:
939 		err = got_error(GOT_ERR_PRIVSEP_MSG);
940 		break;
941 	}
942 
943 	imsg_free(&imsg);
944 
945 	return err;
946 }
947 
948 static const struct got_error *
949 send_commit_logmsg(struct imsgbuf *ibuf, struct got_commit_object *commit,
950     size_t logmsg_len)
951 {
952 	const struct got_error *err = NULL;
953 	size_t offset, remain;
954 
955 	offset = 0;
956 	remain = logmsg_len;
957 	while (remain > 0) {
958 		size_t n = MIN(MAX_IMSGSIZE - IMSG_HEADER_SIZE, remain);
959 
960 		if (imsg_compose(ibuf, GOT_IMSG_COMMIT_LOGMSG, 0, 0, -1,
961 		    commit->logmsg + offset, n) == -1) {
962 			err = got_error_from_errno("imsg_compose "
963 			    "COMMIT_LOGMSG");
964 			break;
965 		}
966 
967 		err = flush_imsg(ibuf);
968 		if (err)
969 			break;
970 
971 		offset += n;
972 		remain -= n;
973 	}
974 
975 	return err;
976 }
977 
978 const struct got_error *
979 got_privsep_send_commit(struct imsgbuf *ibuf, struct got_commit_object *commit)
980 {
981 	const struct got_error *err = NULL;
982 	struct got_imsg_commit_object *icommit;
983 	uint8_t *buf;
984 	size_t len, total;
985 	struct got_object_qid *qid;
986 	size_t author_len = strlen(commit->author);
987 	size_t committer_len = strlen(commit->committer);
988 	size_t logmsg_len = strlen(commit->logmsg);
989 
990 	total = sizeof(*icommit) + author_len + committer_len +
991 	    commit->nparents * SHA1_DIGEST_LENGTH;
992 
993 	buf = malloc(total);
994 	if (buf == NULL)
995 		return got_error_from_errno("malloc");
996 
997 	icommit = (struct got_imsg_commit_object *)buf;
998 	memcpy(icommit->tree_id, commit->tree_id->sha1,
999 	    sizeof(icommit->tree_id));
1000 	icommit->author_len = author_len;
1001 	icommit->author_time = commit->author_time;
1002 	icommit->author_gmtoff = commit->author_gmtoff;
1003 	icommit->committer_len = committer_len;
1004 	icommit->committer_time = commit->committer_time;
1005 	icommit->committer_gmtoff = commit->committer_gmtoff;
1006 	icommit->logmsg_len = logmsg_len;
1007 	icommit->nparents = commit->nparents;
1008 
1009 	len = sizeof(*icommit);
1010 	memcpy(buf + len, commit->author, author_len);
1011 	len += author_len;
1012 	memcpy(buf + len, commit->committer, committer_len);
1013 	len += committer_len;
1014 	SIMPLEQ_FOREACH(qid, &commit->parent_ids, entry) {
1015 		memcpy(buf + len, qid->id, SHA1_DIGEST_LENGTH);
1016 		len += SHA1_DIGEST_LENGTH;
1017 	}
1018 
1019 	if (imsg_compose(ibuf, GOT_IMSG_COMMIT, 0, 0, -1, buf, len) == -1) {
1020 		err = got_error_from_errno("imsg_compose COMMIT");
1021 		goto done;
1022 	}
1023 
1024 	if (logmsg_len == 0 ||
1025 	    logmsg_len + len > MAX_IMSGSIZE - IMSG_HEADER_SIZE) {
1026 		err = flush_imsg(ibuf);
1027 		if (err)
1028 			goto done;
1029 	}
1030 	err = send_commit_logmsg(ibuf, commit, logmsg_len);
1031 done:
1032 	free(buf);
1033 	return err;
1034 }
1035 
1036 static const struct got_error *
1037 get_commit_from_imsg(struct got_commit_object **commit,
1038     struct imsg *imsg, size_t datalen, struct imsgbuf *ibuf)
1039 {
1040 	const struct got_error *err = NULL;
1041 	struct got_imsg_commit_object *icommit;
1042 	size_t len = 0;
1043 	int i;
1044 
1045 	if (datalen < sizeof(*icommit))
1046 		return got_error(GOT_ERR_PRIVSEP_LEN);
1047 
1048 	icommit = imsg->data;
1049 	if (datalen != sizeof(*icommit) + icommit->author_len +
1050 	    icommit->committer_len +
1051 	    icommit->nparents * SHA1_DIGEST_LENGTH)
1052 		return got_error(GOT_ERR_PRIVSEP_LEN);
1053 
1054 	if (icommit->nparents < 0)
1055 		return got_error(GOT_ERR_PRIVSEP_LEN);
1056 
1057 	len += sizeof(*icommit);
1058 
1059 	*commit = got_object_commit_alloc_partial();
1060 	if (*commit == NULL)
1061 		return got_error_from_errno(
1062 		    "got_object_commit_alloc_partial");
1063 
1064 	memcpy((*commit)->tree_id->sha1, icommit->tree_id,
1065 	    SHA1_DIGEST_LENGTH);
1066 	(*commit)->author_time = icommit->author_time;
1067 	(*commit)->author_gmtoff = icommit->author_gmtoff;
1068 	(*commit)->committer_time = icommit->committer_time;
1069 	(*commit)->committer_gmtoff = icommit->committer_gmtoff;
1070 
1071 	if (icommit->author_len == 0) {
1072 		(*commit)->author = strdup("");
1073 		if ((*commit)->author == NULL) {
1074 			err = got_error_from_errno("strdup");
1075 			goto done;
1076 		}
1077 	} else {
1078 		(*commit)->author = malloc(icommit->author_len + 1);
1079 		if ((*commit)->author == NULL) {
1080 			err = got_error_from_errno("malloc");
1081 			goto done;
1082 		}
1083 		memcpy((*commit)->author, imsg->data + len,
1084 		    icommit->author_len);
1085 		(*commit)->author[icommit->author_len] = '\0';
1086 	}
1087 	len += icommit->author_len;
1088 
1089 	if (icommit->committer_len == 0) {
1090 		(*commit)->committer = strdup("");
1091 		if ((*commit)->committer == NULL) {
1092 			err = got_error_from_errno("strdup");
1093 			goto done;
1094 		}
1095 	} else {
1096 		(*commit)->committer =
1097 		    malloc(icommit->committer_len + 1);
1098 		if ((*commit)->committer == NULL) {
1099 			err = got_error_from_errno("malloc");
1100 			goto done;
1101 		}
1102 		memcpy((*commit)->committer, imsg->data + len,
1103 		    icommit->committer_len);
1104 		(*commit)->committer[icommit->committer_len] = '\0';
1105 	}
1106 	len += icommit->committer_len;
1107 
1108 	if (icommit->logmsg_len == 0) {
1109 		(*commit)->logmsg = strdup("");
1110 		if ((*commit)->logmsg == NULL) {
1111 			err = got_error_from_errno("strdup");
1112 			goto done;
1113 		}
1114 	} else {
1115 		size_t offset = 0, remain = icommit->logmsg_len;
1116 
1117 		(*commit)->logmsg = malloc(icommit->logmsg_len + 1);
1118 		if ((*commit)->logmsg == NULL) {
1119 			err = got_error_from_errno("malloc");
1120 			goto done;
1121 		}
1122 		while (remain > 0) {
1123 			struct imsg imsg_log;
1124 			size_t n = MIN(MAX_IMSGSIZE - IMSG_HEADER_SIZE,
1125 			    remain);
1126 
1127 			err = got_privsep_recv_imsg(&imsg_log, ibuf, n);
1128 			if (err)
1129 				goto done;
1130 
1131 			if (imsg_log.hdr.type != GOT_IMSG_COMMIT_LOGMSG) {
1132 				err = got_error(GOT_ERR_PRIVSEP_MSG);
1133 				goto done;
1134 			}
1135 
1136 			memcpy((*commit)->logmsg + offset,
1137 			    imsg_log.data, n);
1138 			imsg_free(&imsg_log);
1139 			offset += n;
1140 			remain -= n;
1141 		}
1142 		(*commit)->logmsg[icommit->logmsg_len] = '\0';
1143 	}
1144 
1145 	for (i = 0; i < icommit->nparents; i++) {
1146 		struct got_object_qid *qid;
1147 
1148 		err = got_object_qid_alloc_partial(&qid);
1149 		if (err)
1150 			break;
1151 		memcpy(qid->id, imsg->data + len +
1152 		    i * SHA1_DIGEST_LENGTH, sizeof(*qid->id));
1153 		SIMPLEQ_INSERT_TAIL(&(*commit)->parent_ids, qid, entry);
1154 		(*commit)->nparents++;
1155 	}
1156 done:
1157 	if (err) {
1158 		got_object_commit_close(*commit);
1159 		*commit = NULL;
1160 	}
1161 	return err;
1162 }
1163 
1164 const struct got_error *
1165 got_privsep_recv_commit(struct got_commit_object **commit, struct imsgbuf *ibuf)
1166 {
1167 	const struct got_error *err = NULL;
1168 	struct imsg imsg;
1169 	size_t datalen;
1170 	const size_t min_datalen =
1171 	    MIN(sizeof(struct got_imsg_error),
1172 	    sizeof(struct got_imsg_commit_object));
1173 
1174 	*commit = NULL;
1175 
1176 	err = got_privsep_recv_imsg(&imsg, ibuf, min_datalen);
1177 	if (err)
1178 		return err;
1179 
1180 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
1181 
1182 	switch (imsg.hdr.type) {
1183 	case GOT_IMSG_COMMIT:
1184 		err = get_commit_from_imsg(commit, &imsg, datalen, ibuf);
1185 		break;
1186 	default:
1187 		err = got_error(GOT_ERR_PRIVSEP_MSG);
1188 		break;
1189 	}
1190 
1191 	imsg_free(&imsg);
1192 
1193 	return err;
1194 }
1195 
1196 const struct got_error *
1197 got_privsep_send_tree(struct imsgbuf *ibuf, struct got_pathlist_head *entries,
1198     int nentries)
1199 {
1200 	const struct got_error *err = NULL;
1201 	struct got_imsg_tree_object itree;
1202 	struct got_pathlist_entry *pe;
1203 	size_t totlen;
1204 	int nimsg; /* number of imsg queued in ibuf */
1205 
1206 	itree.nentries = nentries;
1207 	if (imsg_compose(ibuf, GOT_IMSG_TREE, 0, 0, -1, &itree, sizeof(itree))
1208 	    == -1)
1209 		return got_error_from_errno("imsg_compose TREE");
1210 
1211 	totlen = sizeof(itree);
1212 	nimsg = 1;
1213 	TAILQ_FOREACH(pe, entries, entry) {
1214 		const char *name = pe->path;
1215 		struct got_parsed_tree_entry *pte = pe->data;
1216 		struct ibuf *wbuf;
1217 		size_t namelen = strlen(name);
1218 		size_t len = sizeof(struct got_imsg_tree_entry) + namelen;
1219 
1220 		if (len > MAX_IMSGSIZE)
1221 			return got_error(GOT_ERR_NO_SPACE);
1222 
1223 		nimsg++;
1224 		if (totlen + len >= MAX_IMSGSIZE - (IMSG_HEADER_SIZE * nimsg)) {
1225 			err = flush_imsg(ibuf);
1226 			if (err)
1227 				return err;
1228 			nimsg = 0;
1229 		}
1230 
1231 		wbuf = imsg_create(ibuf, GOT_IMSG_TREE_ENTRY, 0, 0, len);
1232 		if (wbuf == NULL)
1233 			return got_error_from_errno("imsg_create TREE_ENTRY");
1234 
1235 		/* Keep in sync with struct got_imsg_tree_object definition! */
1236 		if (imsg_add(wbuf, pte->id, SHA1_DIGEST_LENGTH) == -1) {
1237 			err = got_error_from_errno("imsg_add TREE_ENTRY");
1238 			ibuf_free(wbuf);
1239 			return err;
1240 		}
1241 		if (imsg_add(wbuf, &pte->mode, sizeof(pte->mode)) == -1) {
1242 			err = got_error_from_errno("imsg_add TREE_ENTRY");
1243 			ibuf_free(wbuf);
1244 			return err;
1245 		}
1246 
1247 		if (imsg_add(wbuf, name, namelen) == -1) {
1248 			err = got_error_from_errno("imsg_add TREE_ENTRY");
1249 			ibuf_free(wbuf);
1250 			return err;
1251 		}
1252 
1253 		wbuf->fd = -1;
1254 		imsg_close(ibuf, wbuf);
1255 
1256 		totlen += len;
1257 	}
1258 
1259 	return flush_imsg(ibuf);
1260 }
1261 
1262 const struct got_error *
1263 got_privsep_recv_tree(struct got_tree_object **tree, struct imsgbuf *ibuf)
1264 {
1265 	const struct got_error *err = NULL;
1266 	const size_t min_datalen =
1267 	    MIN(sizeof(struct got_imsg_error),
1268 	    sizeof(struct got_imsg_tree_object));
1269 	struct got_imsg_tree_object *itree;
1270 	int nentries = 0;
1271 
1272 	*tree = NULL;
1273 get_more:
1274 	err = read_imsg(ibuf);
1275 	if (err)
1276 		goto done;
1277 
1278 	for (;;) {
1279 		struct imsg imsg;
1280 		size_t n;
1281 		size_t datalen;
1282 		struct got_imsg_tree_entry *ite;
1283 		struct got_tree_entry *te = NULL;
1284 
1285 		n = imsg_get(ibuf, &imsg);
1286 		if (n == 0) {
1287 			if (*tree && (*tree)->nentries != nentries)
1288 				goto get_more;
1289 			break;
1290 		}
1291 
1292 		if (imsg.hdr.len < IMSG_HEADER_SIZE + min_datalen)
1293 			return got_error(GOT_ERR_PRIVSEP_LEN);
1294 
1295 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
1296 
1297 		switch (imsg.hdr.type) {
1298 		case GOT_IMSG_ERROR:
1299 			err = recv_imsg_error(&imsg, datalen);
1300 			break;
1301 		case GOT_IMSG_TREE:
1302 			/* This message should only appear once. */
1303 			if (*tree != NULL) {
1304 				err = got_error(GOT_ERR_PRIVSEP_MSG);
1305 				break;
1306 			}
1307 			if (datalen != sizeof(*itree)) {
1308 				err = got_error(GOT_ERR_PRIVSEP_LEN);
1309 				break;
1310 			}
1311 			itree = imsg.data;
1312 			*tree = malloc(sizeof(**tree));
1313 			if (*tree == NULL) {
1314 				err = got_error_from_errno("malloc");
1315 				break;
1316 			}
1317 			(*tree)->entries = calloc(itree->nentries,
1318 			    sizeof(struct got_tree_entry));
1319 			if ((*tree)->entries == NULL) {
1320 				err = got_error_from_errno("malloc");
1321 				break;
1322 			}
1323 			(*tree)->nentries = itree->nentries;
1324 			(*tree)->refcnt = 0;
1325 			break;
1326 		case GOT_IMSG_TREE_ENTRY:
1327 			/* This message should be preceeded by GOT_IMSG_TREE. */
1328 			if (*tree == NULL) {
1329 				err = got_error(GOT_ERR_PRIVSEP_MSG);
1330 				break;
1331 			}
1332 			if (datalen < sizeof(*ite) || datalen > MAX_IMSGSIZE) {
1333 				err = got_error(GOT_ERR_PRIVSEP_LEN);
1334 				break;
1335 			}
1336 
1337 			/* Remaining data contains the entry's name. */
1338 			datalen -= sizeof(*ite);
1339 			if (datalen == 0 || datalen > MAX_IMSGSIZE) {
1340 				err = got_error(GOT_ERR_PRIVSEP_LEN);
1341 				break;
1342 			}
1343 			ite = imsg.data;
1344 
1345 			if (datalen + 1 > sizeof(te->name)) {
1346 				err = got_error(GOT_ERR_NO_SPACE);
1347 				break;
1348 			}
1349 			te = &(*tree)->entries[nentries];
1350 			memcpy(te->name, imsg.data + sizeof(*ite), datalen);
1351 			te->name[datalen] = '\0';
1352 
1353 			memcpy(te->id.sha1, ite->id, SHA1_DIGEST_LENGTH);
1354 			te->mode = ite->mode;
1355 			te->idx = nentries;
1356 			nentries++;
1357 			break;
1358 		default:
1359 			err = got_error(GOT_ERR_PRIVSEP_MSG);
1360 			break;
1361 		}
1362 
1363 		imsg_free(&imsg);
1364 	}
1365 done:
1366 	if (*tree && (*tree)->nentries != nentries) {
1367 		if (err == NULL)
1368 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1369 		got_object_tree_close(*tree);
1370 		*tree = NULL;
1371 	}
1372 
1373 	return err;
1374 }
1375 
1376 const struct got_error *
1377 got_privsep_send_blob(struct imsgbuf *ibuf, size_t size, size_t hdrlen,
1378     const uint8_t *data)
1379 {
1380 	struct got_imsg_blob iblob;
1381 
1382 	iblob.size = size;
1383 	iblob.hdrlen = hdrlen;
1384 
1385 	if (data) {
1386 		uint8_t *buf;
1387 
1388 		if (size > GOT_PRIVSEP_INLINE_BLOB_DATA_MAX)
1389 			return got_error(GOT_ERR_NO_SPACE);
1390 
1391 		buf = malloc(sizeof(iblob) + size);
1392 		if (buf == NULL)
1393 			return got_error_from_errno("malloc");
1394 
1395 		memcpy(buf, &iblob, sizeof(iblob));
1396 		memcpy(buf + sizeof(iblob), data, size);
1397 		if (imsg_compose(ibuf, GOT_IMSG_BLOB, 0, 0, -1, buf,
1398 		   sizeof(iblob) + size) == -1) {
1399 			free(buf);
1400 			return got_error_from_errno("imsg_compose BLOB");
1401 		}
1402 		free(buf);
1403 	} else {
1404 		/* Data has already been written to file descriptor. */
1405 		if (imsg_compose(ibuf, GOT_IMSG_BLOB, 0, 0, -1, &iblob,
1406 		    sizeof(iblob)) == -1)
1407 			return got_error_from_errno("imsg_compose BLOB");
1408 	}
1409 
1410 
1411 	return flush_imsg(ibuf);
1412 }
1413 
1414 const struct got_error *
1415 got_privsep_recv_blob(uint8_t **outbuf, size_t *size, size_t *hdrlen,
1416     struct imsgbuf *ibuf)
1417 {
1418 	const struct got_error *err = NULL;
1419 	struct imsg imsg;
1420 	struct got_imsg_blob *iblob;
1421 	size_t datalen;
1422 
1423 	*outbuf = NULL;
1424 
1425 	err = got_privsep_recv_imsg(&imsg, ibuf, 0);
1426 	if (err)
1427 		return err;
1428 
1429 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
1430 
1431 	switch (imsg.hdr.type) {
1432 	case GOT_IMSG_BLOB:
1433 		if (datalen < sizeof(*iblob)) {
1434 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1435 			break;
1436 		}
1437 		iblob = imsg.data;
1438 		*size = iblob->size;
1439 		*hdrlen = iblob->hdrlen;
1440 
1441 		if (datalen == sizeof(*iblob)) {
1442 			/* Data has been written to file descriptor. */
1443 			break;
1444 		}
1445 
1446 		if (*size > GOT_PRIVSEP_INLINE_BLOB_DATA_MAX) {
1447 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1448 			break;
1449 		}
1450 
1451 		*outbuf = malloc(*size);
1452 		if (*outbuf == NULL) {
1453 			err = got_error_from_errno("malloc");
1454 			break;
1455 		}
1456 		memcpy(*outbuf, imsg.data + sizeof(*iblob), *size);
1457 		break;
1458 	default:
1459 		err = got_error(GOT_ERR_PRIVSEP_MSG);
1460 		break;
1461 	}
1462 
1463 	imsg_free(&imsg);
1464 
1465 	return err;
1466 }
1467 
1468 static const struct got_error *
1469 send_tagmsg(struct imsgbuf *ibuf, struct got_tag_object *tag, size_t tagmsg_len)
1470 {
1471 	const struct got_error *err = NULL;
1472 	size_t offset, remain;
1473 
1474 	offset = 0;
1475 	remain = tagmsg_len;
1476 	while (remain > 0) {
1477 		size_t n = MIN(MAX_IMSGSIZE - IMSG_HEADER_SIZE, remain);
1478 
1479 		if (imsg_compose(ibuf, GOT_IMSG_TAG_TAGMSG, 0, 0, -1,
1480 		    tag->tagmsg + offset, n) == -1) {
1481 			err = got_error_from_errno("imsg_compose TAG_TAGMSG");
1482 			break;
1483 		}
1484 
1485 		err = flush_imsg(ibuf);
1486 		if (err)
1487 			break;
1488 
1489 		offset += n;
1490 		remain -= n;
1491 	}
1492 
1493 	return err;
1494 }
1495 
1496 const struct got_error *
1497 got_privsep_send_tag(struct imsgbuf *ibuf, struct got_tag_object *tag)
1498 {
1499 	const struct got_error *err = NULL;
1500 	struct got_imsg_tag_object *itag;
1501 	uint8_t *buf;
1502 	size_t len, total;
1503 	size_t tag_len = strlen(tag->tag);
1504 	size_t tagger_len = strlen(tag->tagger);
1505 	size_t tagmsg_len = strlen(tag->tagmsg);
1506 
1507 	total = sizeof(*itag) + tag_len + tagger_len + tagmsg_len;
1508 
1509 	buf = malloc(total);
1510 	if (buf == NULL)
1511 		return got_error_from_errno("malloc");
1512 
1513 	itag = (struct got_imsg_tag_object *)buf;
1514 	memcpy(itag->id, tag->id.sha1, sizeof(itag->id));
1515 	itag->obj_type = tag->obj_type;
1516 	itag->tag_len = tag_len;
1517 	itag->tagger_len = tagger_len;
1518 	itag->tagger_time = tag->tagger_time;
1519 	itag->tagger_gmtoff = tag->tagger_gmtoff;
1520 	itag->tagmsg_len = tagmsg_len;
1521 
1522 	len = sizeof(*itag);
1523 	memcpy(buf + len, tag->tag, tag_len);
1524 	len += tag_len;
1525 	memcpy(buf + len, tag->tagger, tagger_len);
1526 	len += tagger_len;
1527 
1528 	if (imsg_compose(ibuf, GOT_IMSG_TAG, 0, 0, -1, buf, len) == -1) {
1529 		err = got_error_from_errno("imsg_compose TAG");
1530 		goto done;
1531 	}
1532 
1533 	if (tagmsg_len == 0 ||
1534 	    tagmsg_len + len > MAX_IMSGSIZE - IMSG_HEADER_SIZE) {
1535 		err = flush_imsg(ibuf);
1536 		if (err)
1537 			goto done;
1538 	}
1539 	err = send_tagmsg(ibuf, tag, tagmsg_len);
1540 done:
1541 	free(buf);
1542 	return err;
1543 }
1544 
1545 const struct got_error *
1546 got_privsep_recv_tag(struct got_tag_object **tag, struct imsgbuf *ibuf)
1547 {
1548 	const struct got_error *err = NULL;
1549 	struct imsg imsg;
1550 	struct got_imsg_tag_object *itag;
1551 	size_t len, datalen;
1552 	const size_t min_datalen =
1553 	    MIN(sizeof(struct got_imsg_error),
1554 	    sizeof(struct got_imsg_tag_object));
1555 
1556 	*tag = NULL;
1557 
1558 	err = got_privsep_recv_imsg(&imsg, ibuf, min_datalen);
1559 	if (err)
1560 		return err;
1561 
1562 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
1563 	len = 0;
1564 
1565 	switch (imsg.hdr.type) {
1566 	case GOT_IMSG_TAG:
1567 		if (datalen < sizeof(*itag)) {
1568 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1569 			break;
1570 		}
1571 		itag = imsg.data;
1572 		if (datalen != sizeof(*itag) + itag->tag_len +
1573 		    itag->tagger_len) {
1574 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1575 			break;
1576 		}
1577 		len += sizeof(*itag);
1578 
1579 		*tag = calloc(1, sizeof(**tag));
1580 		if (*tag == NULL) {
1581 			err = got_error_from_errno("calloc");
1582 			break;
1583 		}
1584 
1585 		memcpy((*tag)->id.sha1, itag->id, SHA1_DIGEST_LENGTH);
1586 
1587 		if (itag->tag_len == 0) {
1588 			(*tag)->tag = strdup("");
1589 			if ((*tag)->tag == NULL) {
1590 				err = got_error_from_errno("strdup");
1591 				break;
1592 			}
1593 		} else {
1594 			(*tag)->tag = malloc(itag->tag_len + 1);
1595 			if ((*tag)->tag == NULL) {
1596 				err = got_error_from_errno("malloc");
1597 				break;
1598 			}
1599 			memcpy((*tag)->tag, imsg.data + len,
1600 			    itag->tag_len);
1601 			(*tag)->tag[itag->tag_len] = '\0';
1602 		}
1603 		len += itag->tag_len;
1604 
1605 		(*tag)->obj_type = itag->obj_type;
1606 		(*tag)->tagger_time = itag->tagger_time;
1607 		(*tag)->tagger_gmtoff = itag->tagger_gmtoff;
1608 
1609 		if (itag->tagger_len == 0) {
1610 			(*tag)->tagger = strdup("");
1611 			if ((*tag)->tagger == NULL) {
1612 				err = got_error_from_errno("strdup");
1613 				break;
1614 			}
1615 		} else {
1616 			(*tag)->tagger = malloc(itag->tagger_len + 1);
1617 			if ((*tag)->tagger == NULL) {
1618 				err = got_error_from_errno("malloc");
1619 				break;
1620 			}
1621 			memcpy((*tag)->tagger, imsg.data + len,
1622 			    itag->tagger_len);
1623 			(*tag)->tagger[itag->tagger_len] = '\0';
1624 		}
1625 		len += itag->tagger_len;
1626 
1627 		if (itag->tagmsg_len == 0) {
1628 			(*tag)->tagmsg = strdup("");
1629 			if ((*tag)->tagmsg == NULL) {
1630 				err = got_error_from_errno("strdup");
1631 				break;
1632 			}
1633 		} else {
1634 			size_t offset = 0, remain = itag->tagmsg_len;
1635 
1636 			(*tag)->tagmsg = malloc(itag->tagmsg_len + 1);
1637 			if ((*tag)->tagmsg == NULL) {
1638 				err = got_error_from_errno("malloc");
1639 				break;
1640 			}
1641 			while (remain > 0) {
1642 				struct imsg imsg_log;
1643 				size_t n = MIN(MAX_IMSGSIZE - IMSG_HEADER_SIZE,
1644 				    remain);
1645 
1646 				err = got_privsep_recv_imsg(&imsg_log, ibuf, n);
1647 				if (err)
1648 					return err;
1649 
1650 				if (imsg_log.hdr.type != GOT_IMSG_TAG_TAGMSG)
1651 					return got_error(GOT_ERR_PRIVSEP_MSG);
1652 
1653 				memcpy((*tag)->tagmsg + offset, imsg_log.data,
1654 				    n);
1655 				imsg_free(&imsg_log);
1656 				offset += n;
1657 				remain -= n;
1658 			}
1659 			(*tag)->tagmsg[itag->tagmsg_len] = '\0';
1660 		}
1661 
1662 		break;
1663 	default:
1664 		err = got_error(GOT_ERR_PRIVSEP_MSG);
1665 		break;
1666 	}
1667 
1668 	imsg_free(&imsg);
1669 
1670 	return err;
1671 }
1672 
1673 const struct got_error *
1674 got_privsep_init_pack_child(struct imsgbuf *ibuf, struct got_pack *pack,
1675     struct got_packidx *packidx)
1676 {
1677 	const struct got_error *err = NULL;
1678 	struct got_imsg_packidx ipackidx;
1679 	struct got_imsg_pack ipack;
1680 	int fd;
1681 
1682 	ipackidx.len = packidx->len;
1683 	fd = dup(packidx->fd);
1684 	if (fd == -1)
1685 		return got_error_from_errno("dup");
1686 
1687 	if (imsg_compose(ibuf, GOT_IMSG_PACKIDX, 0, 0, fd, &ipackidx,
1688 	    sizeof(ipackidx)) == -1) {
1689 		err = got_error_from_errno("imsg_compose PACKIDX");
1690 		close(fd);
1691 		return err;
1692 	}
1693 
1694 	if (strlcpy(ipack.path_packfile, pack->path_packfile,
1695 	    sizeof(ipack.path_packfile)) >= sizeof(ipack.path_packfile))
1696 		return got_error(GOT_ERR_NO_SPACE);
1697 	ipack.filesize = pack->filesize;
1698 
1699 	fd = dup(pack->fd);
1700 	if (fd == -1)
1701 		return got_error_from_errno("dup");
1702 
1703 	if (imsg_compose(ibuf, GOT_IMSG_PACK, 0, 0, fd, &ipack, sizeof(ipack))
1704 	    == -1) {
1705 		err = got_error_from_errno("imsg_compose PACK");
1706 		close(fd);
1707 		return err;
1708 	}
1709 
1710 	return flush_imsg(ibuf);
1711 }
1712 
1713 const struct got_error *
1714 got_privsep_send_packed_obj_req(struct imsgbuf *ibuf, int idx,
1715     struct got_object_id *id)
1716 {
1717 	struct got_imsg_packed_object iobj;
1718 
1719 	iobj.idx = idx;
1720 	memcpy(iobj.id, id->sha1, sizeof(iobj.id));
1721 
1722 	if (imsg_compose(ibuf, GOT_IMSG_PACKED_OBJECT_REQUEST, 0, 0, -1,
1723 	    &iobj, sizeof(iobj)) == -1)
1724 		return got_error_from_errno("imsg_compose "
1725 		    "PACKED_OBJECT_REQUEST");
1726 
1727 	return flush_imsg(ibuf);
1728 }
1729 
1730 const struct got_error *
1731 got_privsep_send_gitconfig_parse_req(struct imsgbuf *ibuf, int fd)
1732 {
1733 	const struct got_error *err = NULL;
1734 
1735 	if (imsg_compose(ibuf, GOT_IMSG_GITCONFIG_PARSE_REQUEST, 0, 0, fd,
1736 	    NULL, 0) == -1) {
1737 		err = got_error_from_errno("imsg_compose "
1738 		    "GITCONFIG_PARSE_REQUEST");
1739 		close(fd);
1740 		return err;
1741 	}
1742 
1743 	return flush_imsg(ibuf);
1744 }
1745 
1746 const struct got_error *
1747 got_privsep_send_gitconfig_repository_format_version_req(struct imsgbuf *ibuf)
1748 {
1749 	if (imsg_compose(ibuf,
1750 	    GOT_IMSG_GITCONFIG_REPOSITORY_FORMAT_VERSION_REQUEST, 0, 0, -1,
1751 	    NULL, 0) == -1)
1752 		return got_error_from_errno("imsg_compose "
1753 		    "GITCONFIG_REPOSITORY_FORMAT_VERSION_REQUEST");
1754 
1755 	return flush_imsg(ibuf);
1756 }
1757 
1758 const struct got_error *
1759 got_privsep_send_gitconfig_author_name_req(struct imsgbuf *ibuf)
1760 {
1761 	if (imsg_compose(ibuf,
1762 	    GOT_IMSG_GITCONFIG_AUTHOR_NAME_REQUEST, 0, 0, -1, NULL, 0) == -1)
1763 		return got_error_from_errno("imsg_compose "
1764 		    "GITCONFIG_AUTHOR_NAME_REQUEST");
1765 
1766 	return flush_imsg(ibuf);
1767 }
1768 
1769 const struct got_error *
1770 got_privsep_send_gitconfig_author_email_req(struct imsgbuf *ibuf)
1771 {
1772 	if (imsg_compose(ibuf,
1773 	    GOT_IMSG_GITCONFIG_AUTHOR_EMAIL_REQUEST, 0, 0, -1, NULL, 0) == -1)
1774 		return got_error_from_errno("imsg_compose "
1775 		    "GITCONFIG_AUTHOR_EMAIL_REQUEST");
1776 
1777 	return flush_imsg(ibuf);
1778 }
1779 
1780 const struct got_error *
1781 got_privsep_send_gitconfig_remotes_req(struct imsgbuf *ibuf)
1782 {
1783 	if (imsg_compose(ibuf,
1784 	    GOT_IMSG_GITCONFIG_REMOTES_REQUEST, 0, 0, -1, NULL, 0) == -1)
1785 		return got_error_from_errno("imsg_compose "
1786 		    "GITCONFIG_REMOTE_REQUEST");
1787 
1788 	return flush_imsg(ibuf);
1789 }
1790 
1791 const struct got_error *
1792 got_privsep_send_gitconfig_owner_req(struct imsgbuf *ibuf)
1793 {
1794 	if (imsg_compose(ibuf,
1795 	    GOT_IMSG_GITCONFIG_OWNER_REQUEST, 0, 0, -1, NULL, 0) == -1)
1796 		return got_error_from_errno("imsg_compose "
1797 		    "GITCONFIG_OWNER_REQUEST");
1798 
1799 	return flush_imsg(ibuf);
1800 }
1801 
1802 const struct got_error *
1803 got_privsep_send_gitconfig_str(struct imsgbuf *ibuf, const char *value)
1804 {
1805 	size_t len = value ? strlen(value) + 1 : 0;
1806 
1807 	if (imsg_compose(ibuf, GOT_IMSG_GITCONFIG_STR_VAL, 0, 0, -1,
1808 	    value, len) == -1)
1809 		return got_error_from_errno("imsg_compose GITCONFIG_STR_VAL");
1810 
1811 	return flush_imsg(ibuf);
1812 }
1813 
1814 const struct got_error *
1815 got_privsep_recv_gitconfig_str(char **str, struct imsgbuf *ibuf)
1816 {
1817 	const struct got_error *err = NULL;
1818 	struct imsg imsg;
1819 	size_t datalen;
1820 	const size_t min_datalen = 0;
1821 
1822 	*str = NULL;
1823 
1824 	err = got_privsep_recv_imsg(&imsg, ibuf, min_datalen);
1825 	if (err)
1826 		return err;
1827 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
1828 
1829 	switch (imsg.hdr.type) {
1830 	case GOT_IMSG_GITCONFIG_STR_VAL:
1831 		if (datalen == 0)
1832 			break;
1833 		*str = malloc(datalen);
1834 		if (*str == NULL) {
1835 			err = got_error_from_errno("malloc");
1836 			break;
1837 		}
1838 		if (strlcpy(*str, imsg.data, datalen) >= datalen)
1839 			err = got_error(GOT_ERR_NO_SPACE);
1840 		break;
1841 	default:
1842 		err = got_error(GOT_ERR_PRIVSEP_MSG);
1843 		break;
1844 	}
1845 
1846 	imsg_free(&imsg);
1847 	return err;
1848 }
1849 
1850 const struct got_error *
1851 got_privsep_send_gitconfig_int(struct imsgbuf *ibuf, int value)
1852 {
1853 	if (imsg_compose(ibuf, GOT_IMSG_GITCONFIG_INT_VAL, 0, 0, -1,
1854 	    &value, sizeof(value)) == -1)
1855 		return got_error_from_errno("imsg_compose GITCONFIG_INT_VAL");
1856 
1857 	return flush_imsg(ibuf);
1858 }
1859 
1860 const struct got_error *
1861 got_privsep_recv_gitconfig_int(int *val, struct imsgbuf *ibuf)
1862 {
1863 	const struct got_error *err = NULL;
1864 	struct imsg imsg;
1865 	size_t datalen;
1866 	const size_t min_datalen =
1867 	    MIN(sizeof(struct got_imsg_error), sizeof(int));
1868 
1869 	*val = 0;
1870 
1871 	err = got_privsep_recv_imsg(&imsg, ibuf, min_datalen);
1872 	if (err)
1873 		return err;
1874 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
1875 
1876 	switch (imsg.hdr.type) {
1877 	case GOT_IMSG_GITCONFIG_INT_VAL:
1878 		if (datalen != sizeof(*val)) {
1879 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1880 			break;
1881 		}
1882 		memcpy(val, imsg.data, sizeof(*val));
1883 		break;
1884 	default:
1885 		err = got_error(GOT_ERR_PRIVSEP_MSG);
1886 		break;
1887 	}
1888 
1889 	imsg_free(&imsg);
1890 	return err;
1891 }
1892 
1893 const struct got_error *
1894 got_privsep_send_gitconfig_remotes(struct imsgbuf *ibuf,
1895     struct got_remote_repo *remotes, int nremotes)
1896 {
1897 	const struct got_error *err = NULL;
1898 	struct got_imsg_remotes iremotes;
1899 	int i;
1900 
1901 	iremotes.nremotes = nremotes;
1902 	if (imsg_compose(ibuf, GOT_IMSG_GITCONFIG_REMOTES, 0, 0, -1,
1903 	    &iremotes, sizeof(iremotes)) == -1)
1904 		return got_error_from_errno("imsg_compose GITCONFIG_REMOTES");
1905 
1906 	err = flush_imsg(ibuf);
1907 	imsg_clear(ibuf);
1908 	if (err)
1909 		return err;
1910 
1911 	for (i = 0; i < nremotes; i++) {
1912 		struct got_imsg_remote iremote;
1913 		size_t len = sizeof(iremote);
1914 		struct ibuf *wbuf;
1915 
1916 		iremote.mirror_references = remotes[i].mirror_references;
1917 		iremote.name_len = strlen(remotes[i].name);
1918 		len += iremote.name_len;
1919 		iremote.url_len = strlen(remotes[i].url);
1920 		len += iremote.url_len;
1921 
1922 		wbuf = imsg_create(ibuf, GOT_IMSG_GITCONFIG_REMOTE, 0, 0, len);
1923 		if (wbuf == NULL)
1924 			return got_error_from_errno(
1925 			    "imsg_create GITCONFIG_REMOTE");
1926 
1927 		if (imsg_add(wbuf, &iremote, sizeof(iremote)) == -1) {
1928 			err = got_error_from_errno(
1929 			    "imsg_add GITCONFIG_REMOTE");
1930 			ibuf_free(wbuf);
1931 			return err;
1932 		}
1933 
1934 		if (imsg_add(wbuf, remotes[i].name, iremote.name_len) == -1) {
1935 			err = got_error_from_errno(
1936 			    "imsg_add GITCONFIG_REMOTE");
1937 			ibuf_free(wbuf);
1938 			return err;
1939 		}
1940 		if (imsg_add(wbuf, remotes[i].url, iremote.url_len) == -1) {
1941 			err = got_error_from_errno(
1942 			    "imsg_add GITCONFIG_REMOTE");
1943 			ibuf_free(wbuf);
1944 			return err;
1945 		}
1946 
1947 		wbuf->fd = -1;
1948 		imsg_close(ibuf, wbuf);
1949 		err = flush_imsg(ibuf);
1950 		if (err)
1951 			return err;
1952 	}
1953 
1954 	return NULL;
1955 }
1956 
1957 const struct got_error *
1958 got_privsep_recv_gitconfig_remotes(struct got_remote_repo **remotes,
1959     int *nremotes, struct imsgbuf *ibuf)
1960 {
1961 	const struct got_error *err = NULL;
1962 	struct imsg imsg;
1963 	size_t datalen;
1964 	struct got_imsg_remotes iremotes;
1965 	struct got_imsg_remote iremote;
1966 
1967 	*remotes = NULL;
1968 	*nremotes = 0;
1969 	iremotes.nremotes = 0;
1970 
1971 	err = got_privsep_recv_imsg(&imsg, ibuf, sizeof(iremotes));
1972 	if (err)
1973 		return err;
1974 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
1975 
1976 	switch (imsg.hdr.type) {
1977 	case GOT_IMSG_GITCONFIG_REMOTES:
1978 		if (datalen != sizeof(iremotes)) {
1979 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1980 			break;
1981 		}
1982 		memcpy(&iremotes, imsg.data, sizeof(iremotes));
1983 		if (iremotes.nremotes == 0) {
1984 			imsg_free(&imsg);
1985 			return NULL;
1986 		}
1987 		break;
1988 	default:
1989 		imsg_free(&imsg);
1990 		return got_error(GOT_ERR_PRIVSEP_MSG);
1991 	}
1992 
1993 	imsg_free(&imsg);
1994 
1995 	*remotes = recallocarray(NULL, 0, iremotes.nremotes, sizeof(**remotes));
1996 	if (*remotes == NULL)
1997 		return got_error_from_errno("recallocarray");
1998 
1999 	while (*nremotes < iremotes.nremotes) {
2000 		struct got_remote_repo *remote;
2001 	
2002 		err = got_privsep_recv_imsg(&imsg, ibuf, sizeof(iremote));
2003 		if (err)
2004 			break;
2005 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
2006 
2007 		switch (imsg.hdr.type) {
2008 		case GOT_IMSG_GITCONFIG_REMOTE:
2009 			remote = &(*remotes)[*nremotes];
2010 			if (datalen < sizeof(iremote)) {
2011 				err = got_error(GOT_ERR_PRIVSEP_LEN);
2012 				break;
2013 			}
2014 			memcpy(&iremote, imsg.data, sizeof(iremote));
2015 			if (iremote.name_len == 0 || iremote.url_len == 0 ||
2016 			    (sizeof(iremote) + iremote.name_len +
2017 			    iremote.url_len) > datalen) {
2018 				err = got_error(GOT_ERR_PRIVSEP_LEN);
2019 				break;
2020 			}
2021 			remote->name = strndup(imsg.data + sizeof(iremote),
2022 			    iremote.name_len);
2023 			if (remote->name == NULL) {
2024 				err = got_error_from_errno("strndup");
2025 				break;
2026 			}
2027 			remote->url = strndup(imsg.data + sizeof(iremote) +
2028 			    iremote.name_len, iremote.url_len);
2029 			if (remote->url == NULL) {
2030 				err = got_error_from_errno("strndup");
2031 				free(remote->name);
2032 				break;
2033 			}
2034 			remote->mirror_references = iremote.mirror_references;
2035 			(*nremotes)++;
2036 			break;
2037 		default:
2038 			err = got_error(GOT_ERR_PRIVSEP_MSG);
2039 			break;
2040 		}
2041 
2042 		imsg_free(&imsg);
2043 		if (err)
2044 			break;
2045 	}
2046 
2047 	if (err) {
2048 		int i;
2049 		for (i = 0; i < *nremotes; i++) {
2050 			free((*remotes)[i].name);
2051 			free((*remotes)[i].url);
2052 		}
2053 		free(*remotes);
2054 		*remotes = NULL;
2055 		*nremotes = 0;
2056 	}
2057 	return err;
2058 }
2059 
2060 const struct got_error *
2061 got_privsep_send_commit_traversal_request(struct imsgbuf *ibuf,
2062      struct got_object_id *id, int idx, const char *path)
2063 {
2064 	const struct got_error *err = NULL;
2065 	struct ibuf *wbuf;
2066 	size_t path_len = strlen(path) + 1;
2067 
2068 	wbuf = imsg_create(ibuf, GOT_IMSG_COMMIT_TRAVERSAL_REQUEST, 0, 0,
2069 	    sizeof(struct got_imsg_commit_traversal_request) + path_len);
2070 	if (wbuf == NULL)
2071 		return got_error_from_errno(
2072 		    "imsg_create COMMIT_TRAVERSAL_REQUEST");
2073 	if (imsg_add(wbuf, id->sha1, SHA1_DIGEST_LENGTH) == -1) {
2074 		err = got_error_from_errno("imsg_add COMMIT_TRAVERSAL_REQUEST");
2075 		ibuf_free(wbuf);
2076 		return err;
2077 	}
2078 	if (imsg_add(wbuf, &idx, sizeof(idx)) == -1) {
2079 		err = got_error_from_errno("imsg_add COMMIT_TRAVERSAL_REQUEST");
2080 		ibuf_free(wbuf);
2081 		return err;
2082 	}
2083 	if (imsg_add(wbuf, path, path_len) == -1) {
2084 		err = got_error_from_errno("imsg_add COMMIT_TRAVERSAL_REQUEST");
2085 		ibuf_free(wbuf);
2086 		return err;
2087 	}
2088 
2089 	wbuf->fd = -1;
2090 	imsg_close(ibuf, wbuf);
2091 
2092 	return flush_imsg(ibuf);
2093 }
2094 
2095 const struct got_error *
2096 got_privsep_send_traversed_commits(struct got_object_id *commit_ids, 
2097     size_t ncommits, struct imsgbuf *ibuf)
2098 {
2099 	const struct got_error *err;
2100 	struct ibuf *wbuf;
2101 	int i;
2102 
2103 	wbuf = imsg_create(ibuf, GOT_IMSG_TRAVERSED_COMMITS, 0, 0,
2104 	    sizeof(struct got_imsg_traversed_commits) +
2105 	    ncommits * SHA1_DIGEST_LENGTH);
2106 	if (wbuf == NULL)
2107 		return got_error_from_errno("imsg_create TRAVERSED_COMMITS");
2108 
2109 	if (imsg_add(wbuf, &ncommits, sizeof(ncommits)) == -1) {
2110 		err = got_error_from_errno("imsg_add TRAVERSED_COMMITS");
2111 		ibuf_free(wbuf);
2112 		return err;
2113 	}
2114 	for (i = 0; i < ncommits; i++) {
2115 		struct got_object_id *id = &commit_ids[i];
2116 		if (imsg_add(wbuf, id->sha1, SHA1_DIGEST_LENGTH) == -1) {
2117 			err = got_error_from_errno(
2118 			    "imsg_add TRAVERSED_COMMITS");
2119 			ibuf_free(wbuf);
2120 			return err;
2121 		}
2122 	}
2123 
2124 	wbuf->fd = -1;
2125 	imsg_close(ibuf, wbuf);
2126 
2127 	return flush_imsg(ibuf);
2128 }
2129 
2130 const struct got_error *
2131 got_privsep_recv_traversed_commits(struct got_commit_object **changed_commit,
2132     struct got_object_id **changed_commit_id,
2133     struct got_object_id_queue *commit_ids, struct imsgbuf *ibuf)
2134 {
2135 	const struct got_error *err = NULL;
2136 	struct imsg imsg;
2137 	struct got_imsg_traversed_commits *icommits;
2138 	size_t datalen;
2139 	int i, done = 0;
2140 
2141 	*changed_commit = NULL;
2142 	*changed_commit_id = NULL;
2143 
2144 	while (!done) {
2145 		err = got_privsep_recv_imsg(&imsg, ibuf, 0);
2146 		if (err)
2147 			return err;
2148 
2149 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
2150 		switch (imsg.hdr.type) {
2151 		case GOT_IMSG_TRAVERSED_COMMITS:
2152 			icommits = imsg.data;
2153 			if (datalen != sizeof(*icommits) +
2154 			    icommits->ncommits * SHA1_DIGEST_LENGTH) {
2155 				err = got_error(GOT_ERR_PRIVSEP_LEN);
2156 				break;
2157 			}
2158 			for (i = 0; i < icommits->ncommits; i++) {
2159 				struct got_object_qid *qid;
2160 				uint8_t *sha1 = (uint8_t *)imsg.data +
2161 				    sizeof(*icommits) + i * SHA1_DIGEST_LENGTH;
2162 				err = got_object_qid_alloc_partial(&qid);
2163 				if (err)
2164 					break;
2165 				memcpy(qid->id->sha1, sha1, SHA1_DIGEST_LENGTH);
2166 				SIMPLEQ_INSERT_TAIL(commit_ids, qid, entry);
2167 
2168 				/* The last commit may contain a change. */
2169 				if (i == icommits->ncommits - 1) {
2170 					*changed_commit_id =
2171 					    got_object_id_dup(qid->id);
2172 					if (*changed_commit_id == NULL) {
2173 						err = got_error_from_errno(
2174 						    "got_object_id_dup");
2175 						break;
2176 					}
2177 				}
2178 			}
2179 			break;
2180 		case GOT_IMSG_COMMIT:
2181 			if (*changed_commit_id == NULL) {
2182 				err = got_error(GOT_ERR_PRIVSEP_MSG);
2183 				break;
2184 			}
2185 			err = get_commit_from_imsg(changed_commit, &imsg,
2186 			    datalen, ibuf);
2187 			break;
2188 		case GOT_IMSG_COMMIT_TRAVERSAL_DONE:
2189 			done = 1;
2190 			break;
2191 		default:
2192 			err = got_error(GOT_ERR_PRIVSEP_MSG);
2193 			break;
2194 		}
2195 
2196 		imsg_free(&imsg);
2197 		if (err)
2198 			break;
2199 	}
2200 
2201 	if (err)
2202 		got_object_id_queue_free(commit_ids);
2203 	return err;
2204 }
2205 
2206 const struct got_error *
2207 got_privsep_send_commit_traversal_done(struct imsgbuf *ibuf)
2208 {
2209 	if (imsg_compose(ibuf, GOT_IMSG_COMMIT_TRAVERSAL_DONE, 0, 0, -1,
2210 	    NULL, 0) == -1)
2211 		return got_error_from_errno("imsg_compose TRAVERSAL_DONE");
2212 
2213 	return flush_imsg(ibuf);
2214 }
2215 
2216 const struct got_error *
2217 got_privsep_unveil_exec_helpers(void)
2218 {
2219 	const char *helpers[] = {
2220 	    GOT_PATH_PROG_READ_PACK,
2221 	    GOT_PATH_PROG_READ_OBJECT,
2222 	    GOT_PATH_PROG_READ_COMMIT,
2223 	    GOT_PATH_PROG_READ_TREE,
2224 	    GOT_PATH_PROG_READ_BLOB,
2225 	    GOT_PATH_PROG_READ_TAG,
2226 	    GOT_PATH_PROG_READ_GITCONFIG,
2227 	    GOT_PATH_PROG_FETCH_PACK,
2228 	    GOT_PATH_PROG_INDEX_PACK,
2229 	};
2230 	int i;
2231 
2232 	for (i = 0; i < nitems(helpers); i++) {
2233 		if (unveil(helpers[i], "x") == 0)
2234 			continue;
2235 		return got_error_from_errno2("unveil", helpers[i]);
2236 	}
2237 
2238 	return NULL;
2239 }
2240 
2241 void
2242 got_privsep_exec_child(int imsg_fds[2], const char *path, const char *repo_path)
2243 {
2244 	if (close(imsg_fds[0]) != 0) {
2245 		fprintf(stderr, "%s: %s\n", getprogname(), strerror(errno));
2246 		_exit(1);
2247 	}
2248 
2249 	if (dup2(imsg_fds[1], GOT_IMSG_FD_CHILD) == -1) {
2250 		fprintf(stderr, "%s: %s\n", getprogname(), strerror(errno));
2251 		_exit(1);
2252 	}
2253 	if (closefrom(GOT_IMSG_FD_CHILD + 1) == -1) {
2254 		fprintf(stderr, "%s: %s\n", getprogname(), strerror(errno));
2255 		_exit(1);
2256 	}
2257 
2258 	if (execl(path, path, repo_path, (char *)NULL) == -1) {
2259 		fprintf(stderr, "%s: %s: %s\n", getprogname(), path,
2260 		    strerror(errno));
2261 		_exit(1);
2262 	}
2263 }