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