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 const struct got_error *
372 got_privsep_send_tmpfd(struct imsgbuf *ibuf, int fd)
373 {
374 	const struct got_error *err = NULL;
375 
376 	if (imsg_compose(ibuf, GOT_IMSG_TMPFD, 0, 0, fd, NULL, 0)
377 	    == -1) {
378 		err = got_error_from_errno("imsg_compose TMPFD");
379 		close(fd);
380 		return err;
381 	}
382 
383 	return flush_imsg(ibuf);
384 }
385 
386 const struct got_error *
387 got_privsep_send_obj(struct imsgbuf *ibuf, struct got_object *obj)
388 {
389 	struct got_imsg_object iobj;
390 
391 	memcpy(iobj.id, obj->id.sha1, sizeof(iobj.id));
392 	iobj.type = obj->type;
393 	iobj.flags = obj->flags;
394 	iobj.hdrlen = obj->hdrlen;
395 	iobj.size = obj->size;
396 	if (iobj.flags & GOT_OBJ_FLAG_PACKED) {
397 		iobj.pack_offset = obj->pack_offset;
398 		iobj.pack_idx = obj->pack_idx;
399 	}
400 
401 	if (imsg_compose(ibuf, GOT_IMSG_OBJECT, 0, 0, -1, &iobj, sizeof(iobj))
402 	    == -1)
403 		return got_error_from_errno("imsg_compose OBJECT");
404 
405 	return flush_imsg(ibuf);
406 }
407 
408 const struct got_error *
409 got_privsep_send_fetch_req(struct imsgbuf *ibuf, int fd,
410    struct got_pathlist_head *have_refs)
411 {
412 	const struct got_error *err = NULL;
413 	struct ibuf *wbuf;
414 	size_t len, n_have_refs = 0;
415 	struct got_pathlist_entry *pe;
416 
417 	len = sizeof(struct got_imsg_fetch_symrefs);
418 	TAILQ_FOREACH(pe, have_refs, entry) {
419 		struct got_object_id *id = pe->data;
420 		len += sizeof(struct got_imsg_fetch_have_ref) +
421 		    pe->path_len + sizeof(id->sha1);
422 		n_have_refs++;
423 	}
424 	if (len >= MAX_IMSGSIZE - IMSG_HEADER_SIZE) {
425 		close(fd);
426 		return got_error(GOT_ERR_NO_SPACE);
427 	}
428 
429 	wbuf = imsg_create(ibuf, GOT_IMSG_FETCH_REQUEST, 0, 0, len);
430 	if (wbuf == NULL) {
431 		close(fd);
432 		return got_error_from_errno("imsg_create FETCH_REQUEST");
433 	}
434 
435 	/* Keep in sync with struct got_imsg_fetch_have_refs definition! */
436 	if (imsg_add(wbuf, &n_have_refs, sizeof(n_have_refs)) == -1) {
437 		err = got_error_from_errno("imsg_add FETCH_REQUEST");
438 		ibuf_free(wbuf);
439 		close(fd);
440 		return err;
441 	}
442 
443 	TAILQ_FOREACH(pe, have_refs, entry) {
444 		const char *name = pe->path;
445 		size_t name_len = pe->path_len;
446 		struct got_object_id *id = pe->data;
447 
448 		/* Keep in sync with struct got_imsg_fetch_have_ref! */
449 		if (imsg_add(wbuf, id->sha1, sizeof(id->sha1)) == -1) {
450 			err = got_error_from_errno("imsg_add FETCH_REQUEST");
451 			ibuf_free(wbuf);
452 			close(fd);
453 			return err;
454 		}
455 		if (imsg_add(wbuf, &name_len, sizeof(name_len)) == -1) {
456 			err = got_error_from_errno("imsg_add FETCH_REQUEST");
457 			ibuf_free(wbuf);
458 			close(fd);
459 			return err;
460 		}
461 		if (imsg_add(wbuf, name, name_len) == -1) {
462 			err = got_error_from_errno("imsg_add FETCH_REQUEST");
463 			ibuf_free(wbuf);
464 			close(fd);
465 			return err;
466 		}
467 	}
468 
469 	wbuf->fd = fd;
470 	imsg_close(ibuf, wbuf);
471 	return flush_imsg(ibuf);
472 }
473 
474 const struct got_error *
475 got_privsep_send_fetch_symrefs(struct imsgbuf *ibuf,
476     struct got_pathlist_head *symrefs)
477 {
478 	const struct got_error *err = NULL;
479 	struct ibuf *wbuf;
480 	size_t len, nsymrefs = 0;
481 	struct got_pathlist_entry *pe;
482 
483 	len = sizeof(struct got_imsg_fetch_symrefs);
484 	TAILQ_FOREACH(pe, symrefs, entry) {
485 		const char *target = pe->data;
486 		len += sizeof(struct got_imsg_fetch_symref) +
487 		    pe->path_len + strlen(target);
488 		nsymrefs++;
489 	}
490 
491 	if (len >= MAX_IMSGSIZE - IMSG_HEADER_SIZE)
492 		return got_error(GOT_ERR_NO_SPACE);
493 
494 	wbuf = imsg_create(ibuf, GOT_IMSG_FETCH_SYMREFS, 0, 0, len);
495 	if (wbuf == NULL)
496 		return got_error_from_errno("imsg_create FETCH_SYMREFS");
497 
498 	/* Keep in sync with struct got_imsg_fetch_symrefs definition! */
499 	if (imsg_add(wbuf, &nsymrefs, sizeof(nsymrefs)) == -1) {
500 		err = got_error_from_errno("imsg_add FETCH_SYMREFS");
501 		ibuf_free(wbuf);
502 		return err;
503 	}
504 
505 	TAILQ_FOREACH(pe, symrefs, entry) {
506 		const char *name = pe->path;
507 		size_t name_len = pe->path_len;
508 		const char *target = pe->data;
509 		size_t target_len = strlen(target);
510 
511 		/* Keep in sync with struct got_imsg_fetch_symref definition! */
512 		if (imsg_add(wbuf, &name_len, sizeof(name_len)) == -1) {
513 			err = got_error_from_errno("imsg_add FETCH_SYMREFS");
514 			ibuf_free(wbuf);
515 			return err;
516 		}
517 		if (imsg_add(wbuf, &target_len, sizeof(target_len)) == -1) {
518 			err = got_error_from_errno("imsg_add FETCH_SYMREFS");
519 			ibuf_free(wbuf);
520 			return err;
521 		}
522 		if (imsg_add(wbuf, name, name_len) == -1) {
523 			err = got_error_from_errno("imsg_add FETCH_SYMREFS");
524 			ibuf_free(wbuf);
525 			return err;
526 		}
527 		if (imsg_add(wbuf, target, target_len) == -1) {
528 			err = got_error_from_errno("imsg_add FETCH_SYMREFS");
529 			ibuf_free(wbuf);
530 			return err;
531 		}
532 	}
533 
534 	wbuf->fd = -1;
535 	imsg_close(ibuf, wbuf);
536 	return flush_imsg(ibuf);
537 }
538 
539 const struct got_error *
540 got_privsep_send_fetch_ref(struct imsgbuf *ibuf,
541     struct got_object_id *refid, const char *refname)
542 {
543 	const struct got_error *err = NULL;
544 	struct ibuf *wbuf;
545 	size_t len, reflen = strlen(refname);
546 
547 	len = sizeof(struct got_imsg_fetch_ref) + reflen;
548 	if (len >= MAX_IMSGSIZE - IMSG_HEADER_SIZE)
549 		return got_error(GOT_ERR_NO_SPACE);
550 
551 	wbuf = imsg_create(ibuf, GOT_IMSG_FETCH_REF, 0, 0, len);
552 	if (wbuf == NULL)
553 		return got_error_from_errno("imsg_create FETCH_REF");
554 
555 	/* Keep in sync with struct got_imsg_fetch_ref definition! */
556 	if (imsg_add(wbuf, refid->sha1, SHA1_DIGEST_LENGTH) == -1) {
557 		err = got_error_from_errno("imsg_add FETCH_REF");
558 		ibuf_free(wbuf);
559 		return err;
560 	}
561 	if (imsg_add(wbuf, refname, reflen) == -1) {
562 		err = got_error_from_errno("imsg_add FETCH_REF");
563 		ibuf_free(wbuf);
564 		return err;
565 	}
566 
567 	wbuf->fd = -1;
568 	imsg_close(ibuf, wbuf);
569 	return flush_imsg(ibuf);
570 }
571 
572 const struct got_error *
573 got_privsep_send_fetch_server_progress(struct imsgbuf *ibuf, const char *msg,
574     size_t msglen)
575 {
576 	if (msglen > MAX_IMSGSIZE - IMSG_HEADER_SIZE)
577 		return got_error(GOT_ERR_NO_SPACE);
578 
579 	if (msglen == 0)
580 		return NULL;
581 
582 	if (imsg_compose(ibuf, GOT_IMSG_FETCH_SERVER_PROGRESS, 0, 0, -1,
583 	    msg, msglen) == -1)
584 		return got_error_from_errno(
585 		    "imsg_compose FETCH_SERVER_PROGRESS");
586 
587 	return flush_imsg(ibuf);
588 }
589 
590 const struct got_error *
591 got_privsep_send_fetch_download_progress(struct imsgbuf *ibuf, off_t bytes)
592 {
593 	if (imsg_compose(ibuf, GOT_IMSG_FETCH_DOWNLOAD_PROGRESS, 0, 0, -1,
594 	    &bytes, sizeof(bytes)) == -1)
595 		return got_error_from_errno(
596 		    "imsg_compose FETCH_DOWNLOAD_PROGRESS");
597 
598 	return flush_imsg(ibuf);
599 }
600 
601 const struct got_error *
602 got_privsep_send_fetch_done(struct imsgbuf *ibuf, struct got_object_id hash)
603 {
604 	if (imsg_compose(ibuf, GOT_IMSG_FETCH_DONE, 0, 0, -1,
605 	    hash.sha1, SHA1_DIGEST_LENGTH) == -1)
606 		return got_error_from_errno("imsg_compose FETCH");
607 	return flush_imsg(ibuf);
608 }
609 
610 
611 const struct got_error *
612 got_privsep_recv_fetch_progress(int *done, struct got_object_id **id,
613     char **refname, struct got_pathlist_head *symrefs, char **server_progress,
614     off_t *packfile_size, struct imsgbuf *ibuf)
615 {
616 	const struct got_error *err = NULL;
617 	struct imsg imsg;
618 	size_t datalen;
619 	struct got_imsg_fetch_symrefs *isymrefs = NULL;
620 	size_t n, remain;
621 	off_t off;
622 	int i;
623 
624 	*done = 0;
625 	*id = NULL;
626 	*refname = NULL;
627 	*server_progress = NULL;
628 
629 	err = got_privsep_recv_imsg(&imsg, ibuf, 0);
630 	if (err)
631 		return err;
632 
633 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
634 	switch (imsg.hdr.type) {
635 	case GOT_IMSG_ERROR:
636 		if (datalen < sizeof(struct got_imsg_error)) {
637 			err = got_error(GOT_ERR_PRIVSEP_LEN);
638 			break;
639 		}
640 		err = recv_imsg_error(&imsg, datalen);
641 		break;
642 	case GOT_IMSG_FETCH_SYMREFS:
643 		if (datalen < sizeof(*isymrefs)) {
644 			err = got_error(GOT_ERR_PRIVSEP_LEN);
645 			break;
646 		}
647 		if (isymrefs != NULL) {
648 			err = got_error(GOT_ERR_PRIVSEP_MSG);
649 			break;
650 		}
651 		isymrefs = (struct got_imsg_fetch_symrefs *)imsg.data;
652 		off = sizeof(*isymrefs);
653 		remain = datalen - off;
654 		for (n = 0; n < isymrefs->nsymrefs; n++) {
655 			struct got_imsg_fetch_symref *s;
656 			char *name, *target;
657 			if (remain < sizeof(struct got_imsg_fetch_symref)) {
658 				err = got_error(GOT_ERR_PRIVSEP_LEN);
659 				goto done;
660 			}
661 			s = (struct got_imsg_fetch_symref *)(imsg.data + off);
662 			off += sizeof(*s);
663 			remain -= sizeof(*s);
664 			if (remain < s->name_len) {
665 				err = got_error(GOT_ERR_PRIVSEP_LEN);
666 				goto done;
667 			}
668 			name = strndup(imsg.data + off, s->name_len);
669 			if (name == NULL) {
670 				err = got_error_from_errno("strndup");
671 				goto done;
672 			}
673 			off += s->name_len;
674 			remain -= s->name_len;
675 			if (remain < s->target_len) {
676 				err = got_error(GOT_ERR_PRIVSEP_LEN);
677 				free(name);
678 				goto done;
679 			}
680 			target = strndup(imsg.data + off, s->target_len);
681 			if (target == NULL) {
682 				err = got_error_from_errno("strndup");
683 				free(name);
684 				goto done;
685 			}
686 			off += s->target_len;
687 			remain -= s->target_len;
688 			err = got_pathlist_append(symrefs, name, target);
689 			if (err) {
690 				free(name);
691 				free(target);
692 				goto done;
693 			}
694 		}
695 		break;
696 	case GOT_IMSG_FETCH_REF:
697 		if (datalen <= SHA1_DIGEST_LENGTH) {
698 			err = got_error(GOT_ERR_PRIVSEP_MSG);
699 			break;
700 		}
701 		*id = malloc(sizeof(**id));
702 		if (*id == NULL) {
703 			err = got_error_from_errno("malloc");
704 			break;
705 		}
706 		memcpy((*id)->sha1, imsg.data, SHA1_DIGEST_LENGTH);
707 		*refname = strndup(imsg.data + SHA1_DIGEST_LENGTH,
708 		    datalen - SHA1_DIGEST_LENGTH);
709 		if (*refname == NULL) {
710 			err = got_error_from_errno("strndup");
711 			break;
712 		}
713 		break;
714 	case GOT_IMSG_FETCH_SERVER_PROGRESS:
715 		if (datalen == 0) {
716 			err = got_error(GOT_ERR_PRIVSEP_LEN);
717 			break;
718 		}
719 		*server_progress = strndup(imsg.data, datalen);
720 		if (*server_progress == NULL) {
721 			err = got_error_from_errno("strndup");
722 			break;
723 		}
724 		for (i = 0; i < datalen; i++) {
725 			if (!isprint((unsigned char)(*server_progress)[i]) &&
726 			    !isspace((unsigned char)(*server_progress)[i])) {
727 				err = got_error(GOT_ERR_PRIVSEP_MSG);
728 				free(*server_progress);
729 				*server_progress = NULL;
730 				goto done;
731 			}
732 		}
733 		break;
734 	case GOT_IMSG_FETCH_DOWNLOAD_PROGRESS:
735 		if (datalen < sizeof(*packfile_size)) {
736 			err = got_error(GOT_ERR_PRIVSEP_MSG);
737 			break;
738 		}
739 		memcpy(packfile_size, imsg.data, sizeof(*packfile_size));
740 		break;
741 	case GOT_IMSG_FETCH_DONE:
742 		*id = malloc(sizeof(**id));
743 		if (*id == NULL) {
744 			err = got_error_from_errno("malloc");
745 			break;
746 		}
747 		if (datalen != SHA1_DIGEST_LENGTH) {
748 			err = got_error(GOT_ERR_PRIVSEP_MSG);
749 			break;
750 		}
751 		memcpy((*id)->sha1, imsg.data, SHA1_DIGEST_LENGTH);
752 		*done = 1;
753 		break;
754 	default:
755 		err = got_error(GOT_ERR_PRIVSEP_MSG);
756 		break;
757 	}
758 done:
759 	if (err) {
760 		free(*id);
761 		*id = NULL;
762 		free(*refname);
763 		*refname = NULL;
764 	}
765 	imsg_free(&imsg);
766 	return err;
767 }
768 
769 const struct got_error *
770 got_privsep_send_index_pack_req(struct imsgbuf *ibuf, uint8_t *pack_hash,
771     int fd)
772 {
773 	const struct got_error *err = NULL;
774 
775 	/* Keep in sync with struct got_imsg_index_pack_request */
776 	if (imsg_compose(ibuf, GOT_IMSG_IDXPACK_REQUEST, 0, 0, fd,
777 	    pack_hash, SHA1_DIGEST_LENGTH) == -1) {
778 		err = got_error_from_errno("imsg_compose INDEX_REQUEST");
779 		close(fd);
780 		return err;
781 	}
782 	return flush_imsg(ibuf);
783 }
784 
785 const struct got_error *
786 got_privsep_send_index_pack_progress(struct imsgbuf *ibuf, int nobj_total,
787     int nobj_indexed, int nobj_loose, int nobj_resolved)
788 {
789 	struct got_imsg_index_pack_progress iprogress;
790 
791 	iprogress.nobj_total = nobj_total;
792 	iprogress.nobj_indexed = nobj_indexed;
793 	iprogress.nobj_loose = nobj_loose;
794 	iprogress.nobj_resolved = nobj_resolved;
795 
796 	if (imsg_compose(ibuf, GOT_IMSG_IDXPACK_PROGRESS, 0, 0, -1,
797 	    &iprogress, sizeof(iprogress)) == -1)
798 		return got_error_from_errno("imsg_compose IDXPACK_PROGRESS");
799 
800 	return flush_imsg(ibuf);
801 }
802 
803 const struct got_error *
804 got_privsep_send_index_pack_done(struct imsgbuf *ibuf)
805 {
806 	if (imsg_compose(ibuf, GOT_IMSG_IDXPACK_DONE, 0, 0, -1, NULL, 0) == -1)
807 		return got_error_from_errno("imsg_compose FETCH");
808 	return flush_imsg(ibuf);
809 }
810 
811 const struct got_error *
812 got_privsep_recv_index_progress(int *done, int *nobj_total,
813     int *nobj_indexed, int *nobj_loose, int *nobj_resolved,
814     struct imsgbuf *ibuf)
815 {
816 	const struct got_error *err = NULL;
817 	struct imsg imsg;
818 	struct got_imsg_index_pack_progress *iprogress;
819 	size_t datalen;
820 
821 	*done = 0;
822 	*nobj_total = 0;
823 	*nobj_indexed = 0;
824 	*nobj_resolved = 0;
825 
826 	err = got_privsep_recv_imsg(&imsg, ibuf, 0);
827 	if (err)
828 		return err;
829 
830 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
831 	switch (imsg.hdr.type) {
832 	case GOT_IMSG_ERROR:
833 		if (datalen < sizeof(struct got_imsg_error)) {
834 			err = got_error(GOT_ERR_PRIVSEP_LEN);
835 			break;
836 		}
837 		err = recv_imsg_error(&imsg, datalen);
838 		break;
839 	case GOT_IMSG_IDXPACK_PROGRESS:
840 		if (datalen < sizeof(*iprogress)) {
841 			err = got_error(GOT_ERR_PRIVSEP_LEN);
842 			break;
843 		}
844 		iprogress = (struct got_imsg_index_pack_progress *)imsg.data;
845 		*nobj_total = iprogress->nobj_total;
846 		*nobj_indexed = iprogress->nobj_indexed;
847 		*nobj_loose = iprogress->nobj_loose;
848 		*nobj_resolved = iprogress->nobj_resolved;
849 		break;
850 	case GOT_IMSG_IDXPACK_DONE:
851 		if (datalen != 0) {
852 			err = got_error(GOT_ERR_PRIVSEP_LEN);
853 			break;
854 		}
855 		*done = 1;
856 		break;
857 	default:
858 		err = got_error(GOT_ERR_PRIVSEP_MSG);
859 		break;
860 	}
861 
862 	imsg_free(&imsg);
863 	return err;
864 }
865 
866 const struct got_error *
867 got_privsep_get_imsg_obj(struct got_object **obj, struct imsg *imsg,
868     struct imsgbuf *ibuf)
869 {
870 	const struct got_error *err = NULL;
871 	struct got_imsg_object *iobj;
872 	size_t datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
873 
874 	if (datalen != sizeof(*iobj))
875 		return got_error(GOT_ERR_PRIVSEP_LEN);
876 	iobj = imsg->data;
877 
878 	*obj = calloc(1, sizeof(**obj));
879 	if (*obj == NULL)
880 		return got_error_from_errno("calloc");
881 
882 	memcpy((*obj)->id.sha1, iobj->id, SHA1_DIGEST_LENGTH);
883 	(*obj)->type = iobj->type;
884 	(*obj)->flags = iobj->flags;
885 	(*obj)->hdrlen = iobj->hdrlen;
886 	(*obj)->size = iobj->size;
887 	/* path_packfile is handled by caller */
888 	if (iobj->flags & GOT_OBJ_FLAG_PACKED) {
889 		(*obj)->pack_offset = iobj->pack_offset;
890 		(*obj)->pack_idx = iobj->pack_idx;
891 	}
892 
893 	return err;
894 }
895 
896 const struct got_error *
897 got_privsep_recv_obj(struct got_object **obj, struct imsgbuf *ibuf)
898 {
899 	const struct got_error *err = NULL;
900 	struct imsg imsg;
901 	const size_t min_datalen =
902 	    MIN(sizeof(struct got_imsg_error), sizeof(struct got_imsg_object));
903 
904 	*obj = NULL;
905 
906 	err = got_privsep_recv_imsg(&imsg, ibuf, min_datalen);
907 	if (err)
908 		return err;
909 
910 	switch (imsg.hdr.type) {
911 	case GOT_IMSG_OBJECT:
912 		err = got_privsep_get_imsg_obj(obj, &imsg, ibuf);
913 		break;
914 	default:
915 		err = got_error(GOT_ERR_PRIVSEP_MSG);
916 		break;
917 	}
918 
919 	imsg_free(&imsg);
920 
921 	return err;
922 }
923 
924 static const struct got_error *
925 send_commit_logmsg(struct imsgbuf *ibuf, struct got_commit_object *commit,
926     size_t logmsg_len)
927 {
928 	const struct got_error *err = NULL;
929 	size_t offset, remain;
930 
931 	offset = 0;
932 	remain = logmsg_len;
933 	while (remain > 0) {
934 		size_t n = MIN(MAX_IMSGSIZE - IMSG_HEADER_SIZE, remain);
935 
936 		if (imsg_compose(ibuf, GOT_IMSG_COMMIT_LOGMSG, 0, 0, -1,
937 		    commit->logmsg + offset, n) == -1) {
938 			err = got_error_from_errno("imsg_compose "
939 			    "COMMIT_LOGMSG");
940 			break;
941 		}
942 
943 		err = flush_imsg(ibuf);
944 		if (err)
945 			break;
946 
947 		offset += n;
948 		remain -= n;
949 	}
950 
951 	return err;
952 }
953 
954 const struct got_error *
955 got_privsep_send_commit(struct imsgbuf *ibuf, struct got_commit_object *commit)
956 {
957 	const struct got_error *err = NULL;
958 	struct got_imsg_commit_object *icommit;
959 	uint8_t *buf;
960 	size_t len, total;
961 	struct got_object_qid *qid;
962 	size_t author_len = strlen(commit->author);
963 	size_t committer_len = strlen(commit->committer);
964 	size_t logmsg_len = strlen(commit->logmsg);
965 
966 	total = sizeof(*icommit) + author_len + committer_len +
967 	    commit->nparents * SHA1_DIGEST_LENGTH;
968 
969 	buf = malloc(total);
970 	if (buf == NULL)
971 		return got_error_from_errno("malloc");
972 
973 	icommit = (struct got_imsg_commit_object *)buf;
974 	memcpy(icommit->tree_id, commit->tree_id->sha1,
975 	    sizeof(icommit->tree_id));
976 	icommit->author_len = author_len;
977 	icommit->author_time = commit->author_time;
978 	icommit->author_gmtoff = commit->author_gmtoff;
979 	icommit->committer_len = committer_len;
980 	icommit->committer_time = commit->committer_time;
981 	icommit->committer_gmtoff = commit->committer_gmtoff;
982 	icommit->logmsg_len = logmsg_len;
983 	icommit->nparents = commit->nparents;
984 
985 	len = sizeof(*icommit);
986 	memcpy(buf + len, commit->author, author_len);
987 	len += author_len;
988 	memcpy(buf + len, commit->committer, committer_len);
989 	len += committer_len;
990 	SIMPLEQ_FOREACH(qid, &commit->parent_ids, entry) {
991 		memcpy(buf + len, qid->id, SHA1_DIGEST_LENGTH);
992 		len += SHA1_DIGEST_LENGTH;
993 	}
994 
995 	if (imsg_compose(ibuf, GOT_IMSG_COMMIT, 0, 0, -1, buf, len) == -1) {
996 		err = got_error_from_errno("imsg_compose COMMIT");
997 		goto done;
998 	}
999 
1000 	if (logmsg_len == 0 ||
1001 	    logmsg_len + len > MAX_IMSGSIZE - IMSG_HEADER_SIZE) {
1002 		err = flush_imsg(ibuf);
1003 		if (err)
1004 			goto done;
1005 	}
1006 	err = send_commit_logmsg(ibuf, commit, logmsg_len);
1007 done:
1008 	free(buf);
1009 	return err;
1010 }
1011 
1012 static const struct got_error *
1013 get_commit_from_imsg(struct got_commit_object **commit,
1014     struct imsg *imsg, size_t datalen, struct imsgbuf *ibuf)
1015 {
1016 	const struct got_error *err = NULL;
1017 	struct got_imsg_commit_object *icommit;
1018 	size_t len = 0;
1019 	int i;
1020 
1021 	if (datalen < sizeof(*icommit))
1022 		return got_error(GOT_ERR_PRIVSEP_LEN);
1023 
1024 	icommit = imsg->data;
1025 	if (datalen != sizeof(*icommit) + icommit->author_len +
1026 	    icommit->committer_len +
1027 	    icommit->nparents * SHA1_DIGEST_LENGTH)
1028 		return got_error(GOT_ERR_PRIVSEP_LEN);
1029 
1030 	if (icommit->nparents < 0)
1031 		return got_error(GOT_ERR_PRIVSEP_LEN);
1032 
1033 	len += sizeof(*icommit);
1034 
1035 	*commit = got_object_commit_alloc_partial();
1036 	if (*commit == NULL)
1037 		return got_error_from_errno(
1038 		    "got_object_commit_alloc_partial");
1039 
1040 	memcpy((*commit)->tree_id->sha1, icommit->tree_id,
1041 	    SHA1_DIGEST_LENGTH);
1042 	(*commit)->author_time = icommit->author_time;
1043 	(*commit)->author_gmtoff = icommit->author_gmtoff;
1044 	(*commit)->committer_time = icommit->committer_time;
1045 	(*commit)->committer_gmtoff = icommit->committer_gmtoff;
1046 
1047 	if (icommit->author_len == 0) {
1048 		(*commit)->author = strdup("");
1049 		if ((*commit)->author == NULL) {
1050 			err = got_error_from_errno("strdup");
1051 			goto done;
1052 		}
1053 	} else {
1054 		(*commit)->author = malloc(icommit->author_len + 1);
1055 		if ((*commit)->author == NULL) {
1056 			err = got_error_from_errno("malloc");
1057 			goto done;
1058 		}
1059 		memcpy((*commit)->author, imsg->data + len,
1060 		    icommit->author_len);
1061 		(*commit)->author[icommit->author_len] = '\0';
1062 	}
1063 	len += icommit->author_len;
1064 
1065 	if (icommit->committer_len == 0) {
1066 		(*commit)->committer = strdup("");
1067 		if ((*commit)->committer == NULL) {
1068 			err = got_error_from_errno("strdup");
1069 			goto done;
1070 		}
1071 	} else {
1072 		(*commit)->committer =
1073 		    malloc(icommit->committer_len + 1);
1074 		if ((*commit)->committer == NULL) {
1075 			err = got_error_from_errno("malloc");
1076 			goto done;
1077 		}
1078 		memcpy((*commit)->committer, imsg->data + len,
1079 		    icommit->committer_len);
1080 		(*commit)->committer[icommit->committer_len] = '\0';
1081 	}
1082 	len += icommit->committer_len;
1083 
1084 	if (icommit->logmsg_len == 0) {
1085 		(*commit)->logmsg = strdup("");
1086 		if ((*commit)->logmsg == NULL) {
1087 			err = got_error_from_errno("strdup");
1088 			goto done;
1089 		}
1090 	} else {
1091 		size_t offset = 0, remain = icommit->logmsg_len;
1092 
1093 		(*commit)->logmsg = malloc(icommit->logmsg_len + 1);
1094 		if ((*commit)->logmsg == NULL) {
1095 			err = got_error_from_errno("malloc");
1096 			goto done;
1097 		}
1098 		while (remain > 0) {
1099 			struct imsg imsg_log;
1100 			size_t n = MIN(MAX_IMSGSIZE - IMSG_HEADER_SIZE,
1101 			    remain);
1102 
1103 			err = got_privsep_recv_imsg(&imsg_log, ibuf, n);
1104 			if (err)
1105 				goto done;
1106 
1107 			if (imsg_log.hdr.type != GOT_IMSG_COMMIT_LOGMSG) {
1108 				err = got_error(GOT_ERR_PRIVSEP_MSG);
1109 				goto done;
1110 			}
1111 
1112 			memcpy((*commit)->logmsg + offset,
1113 			    imsg_log.data, n);
1114 			imsg_free(&imsg_log);
1115 			offset += n;
1116 			remain -= n;
1117 		}
1118 		(*commit)->logmsg[icommit->logmsg_len] = '\0';
1119 	}
1120 
1121 	for (i = 0; i < icommit->nparents; i++) {
1122 		struct got_object_qid *qid;
1123 
1124 		err = got_object_qid_alloc_partial(&qid);
1125 		if (err)
1126 			break;
1127 		memcpy(qid->id, imsg->data + len +
1128 		    i * SHA1_DIGEST_LENGTH, sizeof(*qid->id));
1129 		SIMPLEQ_INSERT_TAIL(&(*commit)->parent_ids, qid, entry);
1130 		(*commit)->nparents++;
1131 	}
1132 done:
1133 	if (err) {
1134 		got_object_commit_close(*commit);
1135 		*commit = NULL;
1136 	}
1137 	return err;
1138 }
1139 
1140 const struct got_error *
1141 got_privsep_recv_commit(struct got_commit_object **commit, struct imsgbuf *ibuf)
1142 {
1143 	const struct got_error *err = NULL;
1144 	struct imsg imsg;
1145 	size_t datalen;
1146 	const size_t min_datalen =
1147 	    MIN(sizeof(struct got_imsg_error),
1148 	    sizeof(struct got_imsg_commit_object));
1149 
1150 	*commit = NULL;
1151 
1152 	err = got_privsep_recv_imsg(&imsg, ibuf, min_datalen);
1153 	if (err)
1154 		return err;
1155 
1156 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
1157 
1158 	switch (imsg.hdr.type) {
1159 	case GOT_IMSG_COMMIT:
1160 		err = get_commit_from_imsg(commit, &imsg, datalen, ibuf);
1161 		break;
1162 	default:
1163 		err = got_error(GOT_ERR_PRIVSEP_MSG);
1164 		break;
1165 	}
1166 
1167 	imsg_free(&imsg);
1168 
1169 	return err;
1170 }
1171 
1172 const struct got_error *
1173 got_privsep_send_tree(struct imsgbuf *ibuf, struct got_pathlist_head *entries,
1174     int nentries)
1175 {
1176 	const struct got_error *err = NULL;
1177 	struct got_imsg_tree_object itree;
1178 	struct got_pathlist_entry *pe;
1179 	size_t totlen;
1180 	int nimsg; /* number of imsg queued in ibuf */
1181 
1182 	itree.nentries = nentries;
1183 	if (imsg_compose(ibuf, GOT_IMSG_TREE, 0, 0, -1, &itree, sizeof(itree))
1184 	    == -1)
1185 		return got_error_from_errno("imsg_compose TREE");
1186 
1187 	totlen = sizeof(itree);
1188 	nimsg = 1;
1189 	TAILQ_FOREACH(pe, entries, entry) {
1190 		const char *name = pe->path;
1191 		struct got_parsed_tree_entry *pte = pe->data;
1192 		struct ibuf *wbuf;
1193 		size_t namelen = strlen(name);
1194 		size_t len = sizeof(struct got_imsg_tree_entry) + namelen;
1195 
1196 		if (len > MAX_IMSGSIZE)
1197 			return got_error(GOT_ERR_NO_SPACE);
1198 
1199 		nimsg++;
1200 		if (totlen + len >= MAX_IMSGSIZE - (IMSG_HEADER_SIZE * nimsg)) {
1201 			err = flush_imsg(ibuf);
1202 			if (err)
1203 				return err;
1204 			nimsg = 0;
1205 		}
1206 
1207 		wbuf = imsg_create(ibuf, GOT_IMSG_TREE_ENTRY, 0, 0, len);
1208 		if (wbuf == NULL)
1209 			return got_error_from_errno("imsg_create TREE_ENTRY");
1210 
1211 		/* Keep in sync with struct got_imsg_tree_object definition! */
1212 		if (imsg_add(wbuf, pte->id, SHA1_DIGEST_LENGTH) == -1) {
1213 			err = got_error_from_errno("imsg_add TREE_ENTRY");
1214 			ibuf_free(wbuf);
1215 			return err;
1216 		}
1217 		if (imsg_add(wbuf, &pte->mode, sizeof(pte->mode)) == -1) {
1218 			err = got_error_from_errno("imsg_add TREE_ENTRY");
1219 			ibuf_free(wbuf);
1220 			return err;
1221 		}
1222 
1223 		if (imsg_add(wbuf, name, namelen) == -1) {
1224 			err = got_error_from_errno("imsg_add TREE_ENTRY");
1225 			ibuf_free(wbuf);
1226 			return err;
1227 		}
1228 
1229 		wbuf->fd = -1;
1230 		imsg_close(ibuf, wbuf);
1231 
1232 		totlen += len;
1233 	}
1234 
1235 	return flush_imsg(ibuf);
1236 }
1237 
1238 const struct got_error *
1239 got_privsep_recv_tree(struct got_tree_object **tree, struct imsgbuf *ibuf)
1240 {
1241 	const struct got_error *err = NULL;
1242 	const size_t min_datalen =
1243 	    MIN(sizeof(struct got_imsg_error),
1244 	    sizeof(struct got_imsg_tree_object));
1245 	struct got_imsg_tree_object *itree;
1246 	int nentries = 0;
1247 
1248 	*tree = NULL;
1249 get_more:
1250 	err = read_imsg(ibuf);
1251 	if (err)
1252 		goto done;
1253 
1254 	for (;;) {
1255 		struct imsg imsg;
1256 		size_t n;
1257 		size_t datalen;
1258 		struct got_imsg_tree_entry *ite;
1259 		struct got_tree_entry *te = NULL;
1260 
1261 		n = imsg_get(ibuf, &imsg);
1262 		if (n == 0) {
1263 			if (*tree && (*tree)->nentries != nentries)
1264 				goto get_more;
1265 			break;
1266 		}
1267 
1268 		if (imsg.hdr.len < IMSG_HEADER_SIZE + min_datalen)
1269 			return got_error(GOT_ERR_PRIVSEP_LEN);
1270 
1271 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
1272 
1273 		switch (imsg.hdr.type) {
1274 		case GOT_IMSG_ERROR:
1275 			err = recv_imsg_error(&imsg, datalen);
1276 			break;
1277 		case GOT_IMSG_TREE:
1278 			/* This message should only appear once. */
1279 			if (*tree != NULL) {
1280 				err = got_error(GOT_ERR_PRIVSEP_MSG);
1281 				break;
1282 			}
1283 			if (datalen != sizeof(*itree)) {
1284 				err = got_error(GOT_ERR_PRIVSEP_LEN);
1285 				break;
1286 			}
1287 			itree = imsg.data;
1288 			*tree = malloc(sizeof(**tree));
1289 			if (*tree == NULL) {
1290 				err = got_error_from_errno("malloc");
1291 				break;
1292 			}
1293 			(*tree)->entries = calloc(itree->nentries,
1294 			    sizeof(struct got_tree_entry));
1295 			if ((*tree)->entries == NULL) {
1296 				err = got_error_from_errno("malloc");
1297 				break;
1298 			}
1299 			(*tree)->nentries = itree->nentries;
1300 			(*tree)->refcnt = 0;
1301 			break;
1302 		case GOT_IMSG_TREE_ENTRY:
1303 			/* This message should be preceeded by GOT_IMSG_TREE. */
1304 			if (*tree == NULL) {
1305 				err = got_error(GOT_ERR_PRIVSEP_MSG);
1306 				break;
1307 			}
1308 			if (datalen < sizeof(*ite) || datalen > MAX_IMSGSIZE) {
1309 				err = got_error(GOT_ERR_PRIVSEP_LEN);
1310 				break;
1311 			}
1312 
1313 			/* Remaining data contains the entry's name. */
1314 			datalen -= sizeof(*ite);
1315 			if (datalen == 0 || datalen > MAX_IMSGSIZE) {
1316 				err = got_error(GOT_ERR_PRIVSEP_LEN);
1317 				break;
1318 			}
1319 			ite = imsg.data;
1320 
1321 			if (datalen + 1 > sizeof(te->name)) {
1322 				err = got_error(GOT_ERR_NO_SPACE);
1323 				break;
1324 			}
1325 			te = &(*tree)->entries[nentries];
1326 			memcpy(te->name, imsg.data + sizeof(*ite), datalen);
1327 			te->name[datalen] = '\0';
1328 
1329 			memcpy(te->id.sha1, ite->id, SHA1_DIGEST_LENGTH);
1330 			te->mode = ite->mode;
1331 			te->idx = nentries;
1332 			nentries++;
1333 			break;
1334 		default:
1335 			err = got_error(GOT_ERR_PRIVSEP_MSG);
1336 			break;
1337 		}
1338 
1339 		imsg_free(&imsg);
1340 	}
1341 done:
1342 	if (*tree && (*tree)->nentries != nentries) {
1343 		if (err == NULL)
1344 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1345 		got_object_tree_close(*tree);
1346 		*tree = NULL;
1347 	}
1348 
1349 	return err;
1350 }
1351 
1352 const struct got_error *
1353 got_privsep_send_blob(struct imsgbuf *ibuf, size_t size, size_t hdrlen,
1354     const uint8_t *data)
1355 {
1356 	struct got_imsg_blob iblob;
1357 
1358 	iblob.size = size;
1359 	iblob.hdrlen = hdrlen;
1360 
1361 	if (data) {
1362 		uint8_t *buf;
1363 
1364 		if (size > GOT_PRIVSEP_INLINE_BLOB_DATA_MAX)
1365 			return got_error(GOT_ERR_NO_SPACE);
1366 
1367 		buf = malloc(sizeof(iblob) + size);
1368 		if (buf == NULL)
1369 			return got_error_from_errno("malloc");
1370 
1371 		memcpy(buf, &iblob, sizeof(iblob));
1372 		memcpy(buf + sizeof(iblob), data, size);
1373 		if (imsg_compose(ibuf, GOT_IMSG_BLOB, 0, 0, -1, buf,
1374 		   sizeof(iblob) + size) == -1) {
1375 			free(buf);
1376 			return got_error_from_errno("imsg_compose BLOB");
1377 		}
1378 		free(buf);
1379 	} else {
1380 		/* Data has already been written to file descriptor. */
1381 		if (imsg_compose(ibuf, GOT_IMSG_BLOB, 0, 0, -1, &iblob,
1382 		    sizeof(iblob)) == -1)
1383 			return got_error_from_errno("imsg_compose BLOB");
1384 	}
1385 
1386 
1387 	return flush_imsg(ibuf);
1388 }
1389 
1390 const struct got_error *
1391 got_privsep_recv_blob(uint8_t **outbuf, size_t *size, size_t *hdrlen,
1392     struct imsgbuf *ibuf)
1393 {
1394 	const struct got_error *err = NULL;
1395 	struct imsg imsg;
1396 	struct got_imsg_blob *iblob;
1397 	size_t datalen;
1398 
1399 	*outbuf = NULL;
1400 
1401 	err = got_privsep_recv_imsg(&imsg, ibuf, 0);
1402 	if (err)
1403 		return err;
1404 
1405 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
1406 
1407 	switch (imsg.hdr.type) {
1408 	case GOT_IMSG_BLOB:
1409 		if (datalen < sizeof(*iblob)) {
1410 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1411 			break;
1412 		}
1413 		iblob = imsg.data;
1414 		*size = iblob->size;
1415 		*hdrlen = iblob->hdrlen;
1416 
1417 		if (datalen == sizeof(*iblob)) {
1418 			/* Data has been written to file descriptor. */
1419 			break;
1420 		}
1421 
1422 		if (*size > GOT_PRIVSEP_INLINE_BLOB_DATA_MAX) {
1423 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1424 			break;
1425 		}
1426 
1427 		*outbuf = malloc(*size);
1428 		if (*outbuf == NULL) {
1429 			err = got_error_from_errno("malloc");
1430 			break;
1431 		}
1432 		memcpy(*outbuf, imsg.data + sizeof(*iblob), *size);
1433 		break;
1434 	default:
1435 		err = got_error(GOT_ERR_PRIVSEP_MSG);
1436 		break;
1437 	}
1438 
1439 	imsg_free(&imsg);
1440 
1441 	return err;
1442 }
1443 
1444 static const struct got_error *
1445 send_tagmsg(struct imsgbuf *ibuf, struct got_tag_object *tag, size_t tagmsg_len)
1446 {
1447 	const struct got_error *err = NULL;
1448 	size_t offset, remain;
1449 
1450 	offset = 0;
1451 	remain = tagmsg_len;
1452 	while (remain > 0) {
1453 		size_t n = MIN(MAX_IMSGSIZE - IMSG_HEADER_SIZE, remain);
1454 
1455 		if (imsg_compose(ibuf, GOT_IMSG_TAG_TAGMSG, 0, 0, -1,
1456 		    tag->tagmsg + offset, n) == -1) {
1457 			err = got_error_from_errno("imsg_compose TAG_TAGMSG");
1458 			break;
1459 		}
1460 
1461 		err = flush_imsg(ibuf);
1462 		if (err)
1463 			break;
1464 
1465 		offset += n;
1466 		remain -= n;
1467 	}
1468 
1469 	return err;
1470 }
1471 
1472 const struct got_error *
1473 got_privsep_send_tag(struct imsgbuf *ibuf, struct got_tag_object *tag)
1474 {
1475 	const struct got_error *err = NULL;
1476 	struct got_imsg_tag_object *itag;
1477 	uint8_t *buf;
1478 	size_t len, total;
1479 	size_t tag_len = strlen(tag->tag);
1480 	size_t tagger_len = strlen(tag->tagger);
1481 	size_t tagmsg_len = strlen(tag->tagmsg);
1482 
1483 	total = sizeof(*itag) + tag_len + tagger_len + tagmsg_len;
1484 
1485 	buf = malloc(total);
1486 	if (buf == NULL)
1487 		return got_error_from_errno("malloc");
1488 
1489 	itag = (struct got_imsg_tag_object *)buf;
1490 	memcpy(itag->id, tag->id.sha1, sizeof(itag->id));
1491 	itag->obj_type = tag->obj_type;
1492 	itag->tag_len = tag_len;
1493 	itag->tagger_len = tagger_len;
1494 	itag->tagger_time = tag->tagger_time;
1495 	itag->tagger_gmtoff = tag->tagger_gmtoff;
1496 	itag->tagmsg_len = tagmsg_len;
1497 
1498 	len = sizeof(*itag);
1499 	memcpy(buf + len, tag->tag, tag_len);
1500 	len += tag_len;
1501 	memcpy(buf + len, tag->tagger, tagger_len);
1502 	len += tagger_len;
1503 
1504 	if (imsg_compose(ibuf, GOT_IMSG_TAG, 0, 0, -1, buf, len) == -1) {
1505 		err = got_error_from_errno("imsg_compose TAG");
1506 		goto done;
1507 	}
1508 
1509 	if (tagmsg_len == 0 ||
1510 	    tagmsg_len + len > MAX_IMSGSIZE - IMSG_HEADER_SIZE) {
1511 		err = flush_imsg(ibuf);
1512 		if (err)
1513 			goto done;
1514 	}
1515 	err = send_tagmsg(ibuf, tag, tagmsg_len);
1516 done:
1517 	free(buf);
1518 	return err;
1519 }
1520 
1521 const struct got_error *
1522 got_privsep_recv_tag(struct got_tag_object **tag, struct imsgbuf *ibuf)
1523 {
1524 	const struct got_error *err = NULL;
1525 	struct imsg imsg;
1526 	struct got_imsg_tag_object *itag;
1527 	size_t len, datalen;
1528 	const size_t min_datalen =
1529 	    MIN(sizeof(struct got_imsg_error),
1530 	    sizeof(struct got_imsg_tag_object));
1531 
1532 	*tag = NULL;
1533 
1534 	err = got_privsep_recv_imsg(&imsg, ibuf, min_datalen);
1535 	if (err)
1536 		return err;
1537 
1538 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
1539 	len = 0;
1540 
1541 	switch (imsg.hdr.type) {
1542 	case GOT_IMSG_TAG:
1543 		if (datalen < sizeof(*itag)) {
1544 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1545 			break;
1546 		}
1547 		itag = imsg.data;
1548 		if (datalen != sizeof(*itag) + itag->tag_len +
1549 		    itag->tagger_len) {
1550 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1551 			break;
1552 		}
1553 		len += sizeof(*itag);
1554 
1555 		*tag = calloc(1, sizeof(**tag));
1556 		if (*tag == NULL) {
1557 			err = got_error_from_errno("calloc");
1558 			break;
1559 		}
1560 
1561 		memcpy((*tag)->id.sha1, itag->id, SHA1_DIGEST_LENGTH);
1562 
1563 		if (itag->tag_len == 0) {
1564 			(*tag)->tag = strdup("");
1565 			if ((*tag)->tag == NULL) {
1566 				err = got_error_from_errno("strdup");
1567 				break;
1568 			}
1569 		} else {
1570 			(*tag)->tag = malloc(itag->tag_len + 1);
1571 			if ((*tag)->tag == NULL) {
1572 				err = got_error_from_errno("malloc");
1573 				break;
1574 			}
1575 			memcpy((*tag)->tag, imsg.data + len,
1576 			    itag->tag_len);
1577 			(*tag)->tag[itag->tag_len] = '\0';
1578 		}
1579 		len += itag->tag_len;
1580 
1581 		(*tag)->obj_type = itag->obj_type;
1582 		(*tag)->tagger_time = itag->tagger_time;
1583 		(*tag)->tagger_gmtoff = itag->tagger_gmtoff;
1584 
1585 		if (itag->tagger_len == 0) {
1586 			(*tag)->tagger = strdup("");
1587 			if ((*tag)->tagger == NULL) {
1588 				err = got_error_from_errno("strdup");
1589 				break;
1590 			}
1591 		} else {
1592 			(*tag)->tagger = malloc(itag->tagger_len + 1);
1593 			if ((*tag)->tagger == NULL) {
1594 				err = got_error_from_errno("malloc");
1595 				break;
1596 			}
1597 			memcpy((*tag)->tagger, imsg.data + len,
1598 			    itag->tagger_len);
1599 			(*tag)->tagger[itag->tagger_len] = '\0';
1600 		}
1601 		len += itag->tagger_len;
1602 
1603 		if (itag->tagmsg_len == 0) {
1604 			(*tag)->tagmsg = strdup("");
1605 			if ((*tag)->tagmsg == NULL) {
1606 				err = got_error_from_errno("strdup");
1607 				break;
1608 			}
1609 		} else {
1610 			size_t offset = 0, remain = itag->tagmsg_len;
1611 
1612 			(*tag)->tagmsg = malloc(itag->tagmsg_len + 1);
1613 			if ((*tag)->tagmsg == NULL) {
1614 				err = got_error_from_errno("malloc");
1615 				break;
1616 			}
1617 			while (remain > 0) {
1618 				struct imsg imsg_log;
1619 				size_t n = MIN(MAX_IMSGSIZE - IMSG_HEADER_SIZE,
1620 				    remain);
1621 
1622 				err = got_privsep_recv_imsg(&imsg_log, ibuf, n);
1623 				if (err)
1624 					return err;
1625 
1626 				if (imsg_log.hdr.type != GOT_IMSG_TAG_TAGMSG)
1627 					return got_error(GOT_ERR_PRIVSEP_MSG);
1628 
1629 				memcpy((*tag)->tagmsg + offset, imsg_log.data,
1630 				    n);
1631 				imsg_free(&imsg_log);
1632 				offset += n;
1633 				remain -= n;
1634 			}
1635 			(*tag)->tagmsg[itag->tagmsg_len] = '\0';
1636 		}
1637 
1638 		break;
1639 	default:
1640 		err = got_error(GOT_ERR_PRIVSEP_MSG);
1641 		break;
1642 	}
1643 
1644 	imsg_free(&imsg);
1645 
1646 	return err;
1647 }
1648 
1649 const struct got_error *
1650 got_privsep_init_pack_child(struct imsgbuf *ibuf, struct got_pack *pack,
1651     struct got_packidx *packidx)
1652 {
1653 	const struct got_error *err = NULL;
1654 	struct got_imsg_packidx ipackidx;
1655 	struct got_imsg_pack ipack;
1656 	int fd;
1657 
1658 	ipackidx.len = packidx->len;
1659 	fd = dup(packidx->fd);
1660 	if (fd == -1)
1661 		return got_error_from_errno("dup");
1662 
1663 	if (imsg_compose(ibuf, GOT_IMSG_PACKIDX, 0, 0, fd, &ipackidx,
1664 	    sizeof(ipackidx)) == -1) {
1665 		err = got_error_from_errno("imsg_compose PACKIDX");
1666 		close(fd);
1667 		return err;
1668 	}
1669 
1670 	if (strlcpy(ipack.path_packfile, pack->path_packfile,
1671 	    sizeof(ipack.path_packfile)) >= sizeof(ipack.path_packfile))
1672 		return got_error(GOT_ERR_NO_SPACE);
1673 	ipack.filesize = pack->filesize;
1674 
1675 	fd = dup(pack->fd);
1676 	if (fd == -1)
1677 		return got_error_from_errno("dup");
1678 
1679 	if (imsg_compose(ibuf, GOT_IMSG_PACK, 0, 0, fd, &ipack, sizeof(ipack))
1680 	    == -1) {
1681 		err = got_error_from_errno("imsg_compose PACK");
1682 		close(fd);
1683 		return err;
1684 	}
1685 
1686 	return flush_imsg(ibuf);
1687 }
1688 
1689 const struct got_error *
1690 got_privsep_send_packed_obj_req(struct imsgbuf *ibuf, int idx,
1691     struct got_object_id *id)
1692 {
1693 	struct got_imsg_packed_object iobj;
1694 
1695 	iobj.idx = idx;
1696 	memcpy(iobj.id, id->sha1, sizeof(iobj.id));
1697 
1698 	if (imsg_compose(ibuf, GOT_IMSG_PACKED_OBJECT_REQUEST, 0, 0, -1,
1699 	    &iobj, sizeof(iobj)) == -1)
1700 		return got_error_from_errno("imsg_compose "
1701 		    "PACKED_OBJECT_REQUEST");
1702 
1703 	return flush_imsg(ibuf);
1704 }
1705 
1706 const struct got_error *
1707 got_privsep_send_gitconfig_parse_req(struct imsgbuf *ibuf, int fd)
1708 {
1709 	const struct got_error *err = NULL;
1710 
1711 	if (imsg_compose(ibuf, GOT_IMSG_GITCONFIG_PARSE_REQUEST, 0, 0, fd,
1712 	    NULL, 0) == -1) {
1713 		err = got_error_from_errno("imsg_compose "
1714 		    "GITCONFIG_PARSE_REQUEST");
1715 		close(fd);
1716 		return err;
1717 	}
1718 
1719 	return flush_imsg(ibuf);
1720 }
1721 
1722 const struct got_error *
1723 got_privsep_send_gitconfig_repository_format_version_req(struct imsgbuf *ibuf)
1724 {
1725 	if (imsg_compose(ibuf,
1726 	    GOT_IMSG_GITCONFIG_REPOSITORY_FORMAT_VERSION_REQUEST, 0, 0, -1,
1727 	    NULL, 0) == -1)
1728 		return got_error_from_errno("imsg_compose "
1729 		    "GITCONFIG_REPOSITORY_FORMAT_VERSION_REQUEST");
1730 
1731 	return flush_imsg(ibuf);
1732 }
1733 
1734 const struct got_error *
1735 got_privsep_send_gitconfig_author_name_req(struct imsgbuf *ibuf)
1736 {
1737 	if (imsg_compose(ibuf,
1738 	    GOT_IMSG_GITCONFIG_AUTHOR_NAME_REQUEST, 0, 0, -1, NULL, 0) == -1)
1739 		return got_error_from_errno("imsg_compose "
1740 		    "GITCONFIG_AUTHOR_NAME_REQUEST");
1741 
1742 	return flush_imsg(ibuf);
1743 }
1744 
1745 const struct got_error *
1746 got_privsep_send_gitconfig_author_email_req(struct imsgbuf *ibuf)
1747 {
1748 	if (imsg_compose(ibuf,
1749 	    GOT_IMSG_GITCONFIG_AUTHOR_EMAIL_REQUEST, 0, 0, -1, NULL, 0) == -1)
1750 		return got_error_from_errno("imsg_compose "
1751 		    "GITCONFIG_AUTHOR_EMAIL_REQUEST");
1752 
1753 	return flush_imsg(ibuf);
1754 }
1755 
1756 const struct got_error *
1757 got_privsep_send_gitconfig_remotes_req(struct imsgbuf *ibuf)
1758 {
1759 	if (imsg_compose(ibuf,
1760 	    GOT_IMSG_GITCONFIG_REMOTES_REQUEST, 0, 0, -1, NULL, 0) == -1)
1761 		return got_error_from_errno("imsg_compose "
1762 		    "GITCONFIG_REMOTE_REQUEST");
1763 
1764 	return flush_imsg(ibuf);
1765 }
1766 
1767 const struct got_error *
1768 got_privsep_send_gitconfig_owner_req(struct imsgbuf *ibuf)
1769 {
1770 	if (imsg_compose(ibuf,
1771 	    GOT_IMSG_GITCONFIG_OWNER_REQUEST, 0, 0, -1, NULL, 0) == -1)
1772 		return got_error_from_errno("imsg_compose "
1773 		    "GITCONFIG_OWNER_REQUEST");
1774 
1775 	return flush_imsg(ibuf);
1776 }
1777 
1778 const struct got_error *
1779 got_privsep_send_gitconfig_str(struct imsgbuf *ibuf, const char *value)
1780 {
1781 	size_t len = value ? strlen(value) + 1 : 0;
1782 
1783 	if (imsg_compose(ibuf, GOT_IMSG_GITCONFIG_STR_VAL, 0, 0, -1,
1784 	    value, len) == -1)
1785 		return got_error_from_errno("imsg_compose GITCONFIG_STR_VAL");
1786 
1787 	return flush_imsg(ibuf);
1788 }
1789 
1790 const struct got_error *
1791 got_privsep_recv_gitconfig_str(char **str, struct imsgbuf *ibuf)
1792 {
1793 	const struct got_error *err = NULL;
1794 	struct imsg imsg;
1795 	size_t datalen;
1796 	const size_t min_datalen = 0;
1797 
1798 	*str = NULL;
1799 
1800 	err = got_privsep_recv_imsg(&imsg, ibuf, min_datalen);
1801 	if (err)
1802 		return err;
1803 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
1804 
1805 	switch (imsg.hdr.type) {
1806 	case GOT_IMSG_GITCONFIG_STR_VAL:
1807 		if (datalen == 0)
1808 			break;
1809 		*str = malloc(datalen);
1810 		if (*str == NULL) {
1811 			err = got_error_from_errno("malloc");
1812 			break;
1813 		}
1814 		if (strlcpy(*str, imsg.data, datalen) >= datalen)
1815 			err = got_error(GOT_ERR_NO_SPACE);
1816 		break;
1817 	default:
1818 		err = got_error(GOT_ERR_PRIVSEP_MSG);
1819 		break;
1820 	}
1821 
1822 	imsg_free(&imsg);
1823 	return err;
1824 }
1825 
1826 const struct got_error *
1827 got_privsep_send_gitconfig_int(struct imsgbuf *ibuf, int value)
1828 {
1829 	if (imsg_compose(ibuf, GOT_IMSG_GITCONFIG_INT_VAL, 0, 0, -1,
1830 	    &value, sizeof(value)) == -1)
1831 		return got_error_from_errno("imsg_compose GITCONFIG_INT_VAL");
1832 
1833 	return flush_imsg(ibuf);
1834 }
1835 
1836 const struct got_error *
1837 got_privsep_recv_gitconfig_int(int *val, struct imsgbuf *ibuf)
1838 {
1839 	const struct got_error *err = NULL;
1840 	struct imsg imsg;
1841 	size_t datalen;
1842 	const size_t min_datalen =
1843 	    MIN(sizeof(struct got_imsg_error), sizeof(int));
1844 
1845 	*val = 0;
1846 
1847 	err = got_privsep_recv_imsg(&imsg, ibuf, min_datalen);
1848 	if (err)
1849 		return err;
1850 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
1851 
1852 	switch (imsg.hdr.type) {
1853 	case GOT_IMSG_GITCONFIG_INT_VAL:
1854 		if (datalen != sizeof(*val)) {
1855 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1856 			break;
1857 		}
1858 		memcpy(val, imsg.data, sizeof(*val));
1859 		break;
1860 	default:
1861 		err = got_error(GOT_ERR_PRIVSEP_MSG);
1862 		break;
1863 	}
1864 
1865 	imsg_free(&imsg);
1866 	return err;
1867 }
1868 
1869 const struct got_error *
1870 got_privsep_send_gitconfig_remotes(struct imsgbuf *ibuf,
1871     struct got_remote_repo *remotes, int nremotes)
1872 {
1873 	const struct got_error *err = NULL;
1874 	struct got_imsg_remotes iremotes;
1875 	int i;
1876 
1877 	iremotes.nremotes = nremotes;
1878 	if (imsg_compose(ibuf, GOT_IMSG_GITCONFIG_REMOTES, 0, 0, -1,
1879 	    &iremotes, sizeof(iremotes)) == -1)
1880 		return got_error_from_errno("imsg_compose GITCONFIG_REMOTES");
1881 
1882 	err = flush_imsg(ibuf);
1883 	imsg_clear(ibuf);
1884 	if (err)
1885 		return err;
1886 
1887 	for (i = 0; i < nremotes; i++) {
1888 		struct got_imsg_remote iremote;
1889 		size_t len = sizeof(iremote);
1890 		struct ibuf *wbuf;
1891 
1892 		iremote.name_len = strlen(remotes[i].name);
1893 		len += iremote.name_len;
1894 		iremote.url_len = strlen(remotes[i].url);
1895 		len += iremote.url_len;
1896 
1897 		wbuf = imsg_create(ibuf, GOT_IMSG_GITCONFIG_REMOTE, 0, 0, len);
1898 		if (wbuf == NULL)
1899 			return got_error_from_errno(
1900 			    "imsg_create GITCONFIG_REMOTE");
1901 
1902 		if (imsg_add(wbuf, &iremote, sizeof(iremote)) == -1) {
1903 			err = got_error_from_errno(
1904 			    "imsg_add GIITCONFIG_REMOTE");
1905 			ibuf_free(wbuf);
1906 			return err;
1907 		}
1908 
1909 		if (imsg_add(wbuf, remotes[i].name, iremote.name_len) == -1) {
1910 			err = got_error_from_errno(
1911 			    "imsg_add GIITCONFIG_REMOTE");
1912 			ibuf_free(wbuf);
1913 			return err;
1914 		}
1915 		if (imsg_add(wbuf, remotes[i].url, iremote.url_len) == -1) {
1916 			err = got_error_from_errno(
1917 			    "imsg_add GIITCONFIG_REMOTE");
1918 			ibuf_free(wbuf);
1919 			return err;
1920 		}
1921 
1922 		wbuf->fd = -1;
1923 		imsg_close(ibuf, wbuf);
1924 		err = flush_imsg(ibuf);
1925 		if (err)
1926 			return err;
1927 	}
1928 
1929 	return NULL;
1930 }
1931 
1932 const struct got_error *
1933 got_privsep_recv_gitconfig_remotes(struct got_remote_repo **remotes,
1934     int *nremotes, struct imsgbuf *ibuf)
1935 {
1936 	const struct got_error *err = NULL;
1937 	struct imsg imsg;
1938 	size_t datalen;
1939 	struct got_imsg_remotes iremotes;
1940 	struct got_imsg_remote iremote;
1941 
1942 	*remotes = NULL;
1943 	*nremotes = 0;
1944 	iremotes.nremotes = 0;
1945 
1946 	err = got_privsep_recv_imsg(&imsg, ibuf, sizeof(iremotes));
1947 	if (err)
1948 		return err;
1949 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
1950 
1951 	switch (imsg.hdr.type) {
1952 	case GOT_IMSG_GITCONFIG_REMOTES:
1953 		if (datalen != sizeof(iremotes)) {
1954 			err = got_error(GOT_ERR_PRIVSEP_LEN);
1955 			break;
1956 		}
1957 		memcpy(&iremotes, imsg.data, sizeof(iremotes));
1958 		if (iremotes.nremotes == 0) {
1959 			imsg_free(&imsg);
1960 			return NULL;
1961 		}
1962 		break;
1963 	default:
1964 		imsg_free(&imsg);
1965 		return got_error(GOT_ERR_PRIVSEP_MSG);
1966 	}
1967 
1968 	imsg_free(&imsg);
1969 
1970 	*remotes = recallocarray(NULL, 0, iremotes.nremotes, sizeof(iremote));
1971 	if (*remotes == NULL)
1972 		return got_error_from_errno("recallocarray");
1973 
1974 	while (*nremotes < iremotes.nremotes) {
1975 		struct got_remote_repo *remote;
1976 	
1977 		err = got_privsep_recv_imsg(&imsg, ibuf, sizeof(iremote));
1978 		if (err)
1979 			break;
1980 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
1981 
1982 		switch (imsg.hdr.type) {
1983 		case GOT_IMSG_GITCONFIG_REMOTE:
1984 			remote = &(*remotes)[*nremotes];
1985 			if (datalen < sizeof(iremote)) {
1986 				err = got_error(GOT_ERR_PRIVSEP_LEN);
1987 				break;
1988 			}
1989 			memcpy(&iremote, imsg.data, sizeof(iremote));
1990 			if (iremote.name_len == 0 || iremote.url_len == 0 ||
1991 			    (sizeof(iremote) + iremote.name_len +
1992 			    iremote.url_len) > datalen) {
1993 				err = got_error(GOT_ERR_PRIVSEP_LEN);
1994 				break;
1995 			}
1996 			remote->name = strndup(imsg.data + sizeof(iremote),
1997 			    iremote.name_len);
1998 			if (remote->name == NULL) {
1999 				err = got_error_from_errno("strndup");
2000 				break;
2001 			}
2002 			remote->url = strndup(imsg.data + sizeof(iremote) +
2003 			    iremote.name_len, iremote.url_len);
2004 			if (remote->url == NULL) {
2005 				err = got_error_from_errno("strndup");
2006 				free(remote->name);
2007 				break;
2008 			}
2009 			(*nremotes)++;
2010 			break;
2011 		default:
2012 			err = got_error(GOT_ERR_PRIVSEP_MSG);
2013 			break;
2014 		}
2015 
2016 		imsg_free(&imsg);
2017 		if (err)
2018 			break;
2019 	}
2020 
2021 	if (err) {
2022 		int i;
2023 		for (i = 0; i < *nremotes; i++) {
2024 			free((*remotes)[i].name);
2025 			free((*remotes)[i].url);
2026 		}
2027 		free(*remotes);
2028 		*remotes = NULL;
2029 		*nremotes = 0;
2030 	}
2031 	return err;
2032 }
2033 
2034 const struct got_error *
2035 got_privsep_send_commit_traversal_request(struct imsgbuf *ibuf,
2036      struct got_object_id *id, int idx, const char *path)
2037 {
2038 	const struct got_error *err = NULL;
2039 	struct ibuf *wbuf;
2040 	size_t path_len = strlen(path) + 1;
2041 
2042 	wbuf = imsg_create(ibuf, GOT_IMSG_COMMIT_TRAVERSAL_REQUEST, 0, 0,
2043 	    sizeof(struct got_imsg_commit_traversal_request) + path_len);
2044 	if (wbuf == NULL)
2045 		return got_error_from_errno(
2046 		    "imsg_create COMMIT_TRAVERSAL_REQUEST");
2047 	if (imsg_add(wbuf, id->sha1, SHA1_DIGEST_LENGTH) == -1) {
2048 		err = got_error_from_errno("imsg_add COMMIT_TRAVERSAL_REQUEST");
2049 		ibuf_free(wbuf);
2050 		return err;
2051 	}
2052 	if (imsg_add(wbuf, &idx, sizeof(idx)) == -1) {
2053 		err = got_error_from_errno("imsg_add COMMIT_TRAVERSAL_REQUEST");
2054 		ibuf_free(wbuf);
2055 		return err;
2056 	}
2057 	if (imsg_add(wbuf, path, path_len) == -1) {
2058 		err = got_error_from_errno("imsg_add COMMIT_TRAVERSAL_REQUEST");
2059 		ibuf_free(wbuf);
2060 		return err;
2061 	}
2062 
2063 	wbuf->fd = -1;
2064 	imsg_close(ibuf, wbuf);
2065 
2066 	return flush_imsg(ibuf);
2067 }
2068 
2069 const struct got_error *
2070 got_privsep_send_traversed_commits(struct got_object_id *commit_ids, 
2071     size_t ncommits, struct imsgbuf *ibuf)
2072 {
2073 	const struct got_error *err;
2074 	struct ibuf *wbuf;
2075 	int i;
2076 
2077 	wbuf = imsg_create(ibuf, GOT_IMSG_TRAVERSED_COMMITS, 0, 0,
2078 	    sizeof(struct got_imsg_traversed_commits) +
2079 	    ncommits * SHA1_DIGEST_LENGTH);
2080 	if (wbuf == NULL)
2081 		return got_error_from_errno("imsg_create TRAVERSED_COMMITS");
2082 
2083 	if (imsg_add(wbuf, &ncommits, sizeof(ncommits)) == -1) {
2084 		err = got_error_from_errno("imsg_add TRAVERSED_COMMITS");
2085 		ibuf_free(wbuf);
2086 		return err;
2087 	}
2088 	for (i = 0; i < ncommits; i++) {
2089 		struct got_object_id *id = &commit_ids[i];
2090 		if (imsg_add(wbuf, id->sha1, SHA1_DIGEST_LENGTH) == -1) {
2091 			err = got_error_from_errno(
2092 			    "imsg_add TRAVERSED_COMMITS");
2093 			ibuf_free(wbuf);
2094 			return err;
2095 		}
2096 	}
2097 
2098 	wbuf->fd = -1;
2099 	imsg_close(ibuf, wbuf);
2100 
2101 	return flush_imsg(ibuf);
2102 }
2103 
2104 const struct got_error *
2105 got_privsep_recv_traversed_commits(struct got_commit_object **changed_commit,
2106     struct got_object_id **changed_commit_id,
2107     struct got_object_id_queue *commit_ids, struct imsgbuf *ibuf)
2108 {
2109 	const struct got_error *err = NULL;
2110 	struct imsg imsg;
2111 	struct got_imsg_traversed_commits *icommits;
2112 	size_t datalen;
2113 	int i, done = 0;
2114 
2115 	*changed_commit = NULL;
2116 	*changed_commit_id = NULL;
2117 
2118 	while (!done) {
2119 		err = got_privsep_recv_imsg(&imsg, ibuf, 0);
2120 		if (err)
2121 			return err;
2122 
2123 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
2124 		switch (imsg.hdr.type) {
2125 		case GOT_IMSG_TRAVERSED_COMMITS:
2126 			icommits = imsg.data;
2127 			if (datalen != sizeof(*icommits) +
2128 			    icommits->ncommits * SHA1_DIGEST_LENGTH) {
2129 				err = got_error(GOT_ERR_PRIVSEP_LEN);
2130 				break;
2131 			}
2132 			for (i = 0; i < icommits->ncommits; i++) {
2133 				struct got_object_qid *qid;
2134 				uint8_t *sha1 = (uint8_t *)imsg.data +
2135 				    sizeof(*icommits) + i * SHA1_DIGEST_LENGTH;
2136 				err = got_object_qid_alloc_partial(&qid);
2137 				if (err)
2138 					break;
2139 				memcpy(qid->id->sha1, sha1, SHA1_DIGEST_LENGTH);
2140 				SIMPLEQ_INSERT_TAIL(commit_ids, qid, entry);
2141 
2142 				/* The last commit may contain a change. */
2143 				if (i == icommits->ncommits - 1) {
2144 					*changed_commit_id =
2145 					    got_object_id_dup(qid->id);
2146 					if (*changed_commit_id == NULL) {
2147 						err = got_error_from_errno(
2148 						    "got_object_id_dup");
2149 						break;
2150 					}
2151 				}
2152 			}
2153 			break;
2154 		case GOT_IMSG_COMMIT:
2155 			if (*changed_commit_id == NULL) {
2156 				err = got_error(GOT_ERR_PRIVSEP_MSG);
2157 				break;
2158 			}
2159 			err = get_commit_from_imsg(changed_commit, &imsg,
2160 			    datalen, ibuf);
2161 			break;
2162 		case GOT_IMSG_COMMIT_TRAVERSAL_DONE:
2163 			done = 1;
2164 			break;
2165 		default:
2166 			err = got_error(GOT_ERR_PRIVSEP_MSG);
2167 			break;
2168 		}
2169 
2170 		imsg_free(&imsg);
2171 		if (err)
2172 			break;
2173 	}
2174 
2175 	if (err)
2176 		got_object_id_queue_free(commit_ids);
2177 	return err;
2178 }
2179 
2180 const struct got_error *
2181 got_privsep_send_commit_traversal_done(struct imsgbuf *ibuf)
2182 {
2183 	if (imsg_compose(ibuf, GOT_IMSG_COMMIT_TRAVERSAL_DONE, 0, 0, -1,
2184 	    NULL, 0) == -1)
2185 		return got_error_from_errno("imsg_compose TRAVERSAL_DONE");
2186 
2187 	return flush_imsg(ibuf);
2188 }
2189 
2190 const struct got_error *
2191 got_privsep_unveil_exec_helpers(void)
2192 {
2193 	const char *helpers[] = {
2194 	    GOT_PATH_PROG_READ_PACK,
2195 	    GOT_PATH_PROG_READ_OBJECT,
2196 	    GOT_PATH_PROG_READ_COMMIT,
2197 	    GOT_PATH_PROG_READ_TREE,
2198 	    GOT_PATH_PROG_READ_BLOB,
2199 	    GOT_PATH_PROG_READ_TAG,
2200 	    GOT_PATH_PROG_READ_GITCONFIG,
2201 	};
2202 	int i;
2203 
2204 	for (i = 0; i < nitems(helpers); i++) {
2205 		if (unveil(helpers[i], "x") == 0)
2206 			continue;
2207 		return got_error_from_errno2("unveil", helpers[i]);
2208 	}
2209 
2210 	return NULL;
2211 }
2212 
2213 void
2214 got_privsep_exec_child(int imsg_fds[2], const char *path, const char *repo_path)
2215 {
2216 	if (close(imsg_fds[0]) != 0) {
2217 		fprintf(stderr, "%s: %s\n", getprogname(), strerror(errno));
2218 		_exit(1);
2219 	}
2220 
2221 	if (dup2(imsg_fds[1], GOT_IMSG_FD_CHILD) == -1) {
2222 		fprintf(stderr, "%s: %s\n", getprogname(), strerror(errno));
2223 		_exit(1);
2224 	}
2225 	if (closefrom(GOT_IMSG_FD_CHILD + 1) == -1) {
2226 		fprintf(stderr, "%s: %s\n", getprogname(), strerror(errno));
2227 		_exit(1);
2228 	}
2229 
2230 	if (execl(path, path, repo_path, (char *)NULL) == -1) {
2231 		fprintf(stderr, "%s: %s: %s\n", getprogname(), path,
2232 		    strerror(errno));
2233 		_exit(1);
2234 	}
2235 }