1 /*
2  * Copyright (c) 2022 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/queue.h>
18 #include <sys/stat.h>
19 #include <sys/tree.h>
20 #include <sys/types.h>
21 
22 #include <event.h>
23 #include <errno.h>
24 #include <imsg.h>
25 #include <signal.h>
26 #include <siphash.h>
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <string.h>
30 #include <limits.h>
31 #include <poll.h>
32 #include <sha1.h>
33 #include <unistd.h>
34 #include <zlib.h>
35 
36 #include "buf.h"
37 
38 #include "got_error.h"
39 #include "got_repository.h"
40 #include "got_object.h"
41 #include "got_reference.h"
42 #include "got_path.h"
43 
44 #include "got_lib_delta.h"
45 #include "got_lib_delta_cache.h"
46 #include "got_lib_object.h"
47 #include "got_lib_object_cache.h"
48 #include "got_lib_ratelimit.h"
49 #include "got_lib_pack.h"
50 #include "got_lib_pack_index.h"
51 #include "got_lib_repository.h"
52 #include "got_lib_poll.h"
53 
54 #include "got_lib_sha1.h" /* XXX temp include for debugging */
55 
56 #include "log.h"
57 #include "gotd.h"
58 #include "repo_write.h"
59 
60 #ifndef nitems
61 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
62 #endif
63 
64 static struct repo_write {
65 	pid_t pid;
66 	const char *title;
67 	struct got_repository *repo;
68 	int *pack_fds;
69 	int *temp_fds;
70 } repo_write;
71 
72 struct gotd_ref_update {
73 	STAILQ_ENTRY(gotd_ref_update) entry;
74 	struct got_reference *ref;
75 	int ref_is_new;
76 	struct got_object_id old_id;
77 	struct got_object_id new_id;
78 };
79 STAILQ_HEAD(gotd_ref_updates, gotd_ref_update);
80 
81 struct repo_write_client {
82 	STAILQ_ENTRY(repo_write_client)	 entry;
83 	uint32_t			 id;
84 	int				 fd;
85 	int				 pack_pipe[2];
86 	struct got_pack			 pack;
87 	uint8_t				 pack_sha1[SHA1_DIGEST_LENGTH];
88 	int				 packidx_fd;
89 	struct gotd_ref_updates		 ref_updates;
90 	int				 nref_updates;
91 };
92 STAILQ_HEAD(repo_write_clients, repo_write_client);
93 
94 static struct repo_write_clients repo_write_clients[GOTD_CLIENT_TABLE_SIZE];
95 static SIPHASH_KEY clients_hash_key;
96 
97 static uint64_t
98 client_hash(uint32_t client_id)
99 {
100 	return SipHash24(&clients_hash_key, &client_id, sizeof(client_id));
101 }
102 
103 static void
104 add_client(struct repo_write_client *client, uint32_t client_id, int fd)
105 {
106 	uint64_t slot;
107 
108 	client->id = client_id;
109 	client->fd = fd;
110 	client->pack_pipe[0] = -1;
111 	client->pack_pipe[1] = -1;
112 	client->packidx_fd = -1;
113 	STAILQ_INIT(&client->ref_updates);
114 	client->nref_updates = 0;
115 	slot = client_hash(client->id) % nitems(repo_write_clients);
116 	STAILQ_INSERT_HEAD(&repo_write_clients[slot], client, entry);
117 }
118 
119 static struct repo_write_client *
120 find_client(uint32_t client_id)
121 {
122 	uint64_t slot;
123 	struct repo_write_client *c;
124 
125 	slot = client_hash(client_id) % nitems(repo_write_clients);
126 	STAILQ_FOREACH(c, &repo_write_clients[slot], entry) {
127 		if (c->id == client_id)
128 			return c;
129 	}
130 
131 	return NULL;
132 }
133 
134 static volatile sig_atomic_t sigint_received;
135 static volatile sig_atomic_t sigterm_received;
136 
137 static void
138 catch_sigint(int signo)
139 {
140 	sigint_received = 1;
141 }
142 
143 static void
144 catch_sigterm(int signo)
145 {
146 	sigterm_received = 1;
147 }
148 
149 static const struct got_error *
150 check_cancelled(void *arg)
151 {
152 	if (sigint_received || sigterm_received)
153 		return got_error(GOT_ERR_CANCELLED);
154 
155 	return NULL;
156 }
157 
158 static const struct got_error *
159 send_peeled_tag_ref(struct got_reference *ref, struct got_object *obj,
160     struct imsgbuf *ibuf)
161 {
162 	const struct got_error *err = NULL;
163 	struct got_tag_object *tag;
164 	size_t namelen, len;
165 	char *peeled_refname = NULL;
166 	struct got_object_id *id;
167 	struct ibuf *wbuf;
168 
169 	err = got_object_tag_open(&tag, repo_write.repo, obj);
170 	if (err)
171 		return err;
172 
173 	if (asprintf(&peeled_refname, "%s^{}", got_ref_get_name(ref)) == -1) {
174 		err = got_error_from_errno("asprintf");
175 		goto done;
176 	}
177 
178 	id = got_object_tag_get_object_id(tag);
179 	namelen = strlen(peeled_refname);
180 
181 	len = sizeof(struct gotd_imsg_ref) + namelen;
182 	if (len > MAX_IMSGSIZE - IMSG_HEADER_SIZE) {
183 		err = got_error(GOT_ERR_NO_SPACE);
184 		goto done;
185 	}
186 
187 	wbuf = imsg_create(ibuf, GOTD_IMSG_REF, PROC_REPO_WRITE,
188 	    repo_write.pid, len);
189 	if (wbuf == NULL) {
190 		err = got_error_from_errno("imsg_create REF");
191 		goto done;
192 	}
193 
194 	/* Keep in sync with struct gotd_imsg_ref definition. */
195 	if (imsg_add(wbuf, id->sha1, SHA1_DIGEST_LENGTH) == -1) {
196 		err = got_error_from_errno("imsg_add REF");
197 		goto done;
198 	}
199 	if (imsg_add(wbuf, &namelen, sizeof(namelen)) == -1) {
200 		err = got_error_from_errno("imsg_add REF");
201 		goto done;
202 	}
203 	if (imsg_add(wbuf, peeled_refname, namelen) == -1) {
204 		err = got_error_from_errno("imsg_add REF");
205 		goto done;
206 	}
207 
208 	wbuf->fd = -1;
209 	imsg_close(ibuf, wbuf);
210 done:
211 	got_object_tag_close(tag);
212 	return err;
213 }
214 
215 static const struct got_error *
216 send_ref(struct got_reference *ref, struct imsgbuf *ibuf)
217 {
218 	const struct got_error *err;
219 	const char *refname = got_ref_get_name(ref);
220 	size_t namelen;
221 	struct got_object_id *id = NULL;
222 	struct got_object *obj = NULL;
223 	size_t len;
224 	struct ibuf *wbuf;
225 
226 	namelen = strlen(refname);
227 
228 	len = sizeof(struct gotd_imsg_ref) + namelen;
229 	if (len > MAX_IMSGSIZE - IMSG_HEADER_SIZE)
230 		return got_error(GOT_ERR_NO_SPACE);
231 
232 	err = got_ref_resolve(&id, repo_write.repo, ref);
233 	if (err)
234 		return err;
235 
236 	wbuf = imsg_create(ibuf, GOTD_IMSG_REF, PROC_REPO_WRITE,
237 	    repo_write.pid, len);
238 	if (wbuf == NULL) {
239 		err = got_error_from_errno("imsg_create REF");
240 		goto done;
241 	}
242 
243 	/* Keep in sync with struct gotd_imsg_ref definition. */
244 	if (imsg_add(wbuf, id->sha1, SHA1_DIGEST_LENGTH) == -1)
245 		return got_error_from_errno("imsg_add REF");
246 	if (imsg_add(wbuf, &namelen, sizeof(namelen)) == -1)
247 		return got_error_from_errno("imsg_add REF");
248 	if (imsg_add(wbuf, refname, namelen) == -1)
249 		return got_error_from_errno("imsg_add REF");
250 
251 	wbuf->fd = -1;
252 	imsg_close(ibuf, wbuf);
253 
254 	err = got_object_open(&obj, repo_write.repo, id);
255 	if (err)
256 		goto done;
257 	if (obj->type == GOT_OBJ_TYPE_TAG)
258 		err = send_peeled_tag_ref(ref, obj, ibuf);
259 done:
260 	if (obj)
261 		got_object_close(obj);
262 	free(id);
263 	return err;
264 }
265 
266 static const struct got_error *
267 list_refs(struct repo_write_client **client, struct imsg *imsg)
268 {
269 	const struct got_error *err;
270 	struct got_reflist_head refs;
271 	struct got_reflist_entry *re;
272 	struct gotd_imsg_list_refs_internal ireq;
273 	size_t datalen;
274 	struct gotd_imsg_reflist irefs;
275 	struct imsgbuf ibuf;
276 	int client_fd = imsg->fd;
277 
278 	TAILQ_INIT(&refs);
279 
280 	if (client_fd == -1)
281 		return got_error(GOT_ERR_PRIVSEP_NO_FD);
282 
283 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
284 	if (datalen != sizeof(ireq))
285 		return got_error(GOT_ERR_PRIVSEP_LEN);
286 	memcpy(&ireq, imsg->data, sizeof(ireq));
287 
288 	*client = find_client(ireq.client_id);
289 	if (*client)
290 		return got_error_msg(GOT_ERR_CLIENT_ID, "duplicate client ID");
291 
292 	*client = calloc(1, sizeof(**client));
293 	if (*client == NULL)
294 		return got_error_from_errno("calloc");
295 	add_client(*client, ireq.client_id, client_fd);
296 
297 	imsg_init(&ibuf, client_fd);
298 
299 	err = got_ref_list(&refs, repo_write.repo, "",
300 	    got_ref_cmp_by_name, NULL);
301 	if (err)
302 		return err;
303 
304 	memset(&irefs, 0, sizeof(irefs));
305 	TAILQ_FOREACH(re, &refs, entry) {
306 		struct got_object_id *id;
307 		int obj_type;
308 
309 		if (got_ref_is_symbolic(re->ref))
310 			continue;
311 
312 		irefs.nrefs++;
313 
314 		/* Account for a peeled tag refs. */
315 		err = got_ref_resolve(&id, repo_write.repo, re->ref);
316 		if (err)
317 			goto done;
318 		err = got_object_get_type(&obj_type, repo_write.repo, id);	
319 		free(id);
320 		if (err)
321 			goto done;
322 		if (obj_type == GOT_OBJ_TYPE_TAG)
323 			irefs.nrefs++;
324 	}
325 
326 	if (imsg_compose(&ibuf, GOTD_IMSG_REFLIST, PROC_REPO_WRITE,
327 	    repo_write.pid, -1, &irefs, sizeof(irefs)) == -1) {
328 		err = got_error_from_errno("imsg_compose REFLIST");
329 		goto done;
330 	}
331 
332 	TAILQ_FOREACH(re, &refs, entry) {
333 		if (got_ref_is_symbolic(re->ref))
334 			continue;
335 		err = send_ref(re->ref, &ibuf);
336 		if (err)
337 			goto done;
338 	}
339 
340 	err = gotd_imsg_flush(&ibuf);
341 done:
342 	got_ref_list_free(&refs);
343 	imsg_clear(&ibuf);
344 	return err;
345 }
346 
347 static const struct got_error *
348 protect_ref_namespace(struct got_reference *ref, const char *namespace)
349 {
350 	size_t len = strlen(namespace);
351 
352 	if (len < 5 || strncmp("refs/", namespace, 5) != 0 ||
353 	    namespace[len -1] != '/') {
354 		return got_error_fmt(GOT_ERR_BAD_REF_NAME,
355 		    "reference namespace '%s'", namespace);
356 	}
357 
358 	if (strncmp(namespace, got_ref_get_name(ref), len) == 0)
359 		return got_error_fmt(GOT_ERR_REFS_PROTECTED, "%s", namespace);
360 
361 	return NULL;
362 }
363 
364 static const struct got_error *
365 recv_ref_update(struct repo_write_client **client, struct imsg *imsg)
366 {
367 	const struct got_error *err = NULL;
368 	struct gotd_imsg_ref_update iref;
369 	size_t datalen;
370 	char *refname = NULL;
371 	struct got_reference *ref = NULL;
372 	struct got_object_id *id = NULL;
373 	struct imsgbuf ibuf;
374 	struct gotd_ref_update *ref_update = NULL;
375 
376 	log_debug("ref-update received");
377 
378 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
379 	if (datalen < sizeof(iref))
380 		return got_error(GOT_ERR_PRIVSEP_LEN);
381 	memcpy(&iref, imsg->data, sizeof(iref));
382 	if (datalen != sizeof(iref) + iref.name_len)
383 		return got_error(GOT_ERR_PRIVSEP_LEN);
384 
385 	*client = find_client(iref.client_id);
386 	if (*client == NULL)
387 		return got_error(GOT_ERR_CLIENT_ID);
388 
389 	imsg_init(&ibuf, (*client)->fd);
390 
391 	refname = malloc(iref.name_len + 1);
392 	if (refname == NULL)
393 		return got_error_from_errno("malloc");
394 	memcpy(refname, imsg->data + sizeof(iref), iref.name_len);
395 	refname[iref.name_len] = '\0';
396 
397 	ref_update = calloc(1, sizeof(*ref_update));
398 	if (ref_update == NULL) {
399 		err = got_error_from_errno("malloc");
400 		goto done;
401 	}
402 
403 	memcpy(ref_update->old_id.sha1, iref.old_id, SHA1_DIGEST_LENGTH);
404 	memcpy(ref_update->new_id.sha1, iref.new_id, SHA1_DIGEST_LENGTH);
405 
406 	err = got_ref_open(&ref, repo_write.repo, refname, 0);
407 	if (err) {
408 		if (err->code != GOT_ERR_NOT_REF)
409 			goto done;
410 		err = got_ref_alloc(&ref, refname, &ref_update->new_id);
411 		if (err)
412 			goto done;
413 		ref_update->ref_is_new = 1;
414 	}
415 	if (got_ref_is_symbolic(ref)) {
416 		err = got_error_fmt(GOT_ERR_BAD_REF_TYPE,
417 		    "'%s' is a symbolic reference and cannot "
418 		    "be updated", got_ref_get_name(ref));
419 		goto done;
420 	}
421 	if (strncmp("refs/", got_ref_get_name(ref), 5) != 0) {
422 		err = got_error_fmt(GOT_ERR_BAD_REF_NAME,
423 		    "%s: does not begin with 'refs/'",
424 		    got_ref_get_name(ref));
425 		goto done;
426 	}
427 
428 	err = protect_ref_namespace(ref, "refs/got/");
429 	if (err)
430 		goto done;
431 	err = protect_ref_namespace(ref, "refs/remotes/");
432 	if (err)
433 		goto done;
434 
435 	if (!ref_update->ref_is_new) {
436 		/*
437 		 * Ensure the client's idea of this update is still valid.
438 		 * At this point we can only return an error, to prevent
439 		 * the client from uploading a pack file which will likely
440 		 * have to be discarded.
441 		 */
442 		err = got_ref_resolve(&id, repo_write.repo, ref);
443 		if (err)
444 			goto done;
445 
446 		if (got_object_id_cmp(id, &ref_update->old_id) != 0) {
447 			err = got_error_fmt(GOT_ERR_REF_BUSY,
448 			    "%s has been modified by someone else "
449 			    "while transaction was in progress",
450 			    got_ref_get_name(ref));
451 			goto done;
452 		}
453 	}
454 
455 	gotd_imsg_send_ack(&ref_update->new_id, &ibuf, PROC_REPO_WRITE,
456 	    repo_write.pid);
457 
458 	ref_update->ref = ref;
459 	STAILQ_INSERT_HEAD(&(*client)->ref_updates, ref_update, entry);
460 	(*client)->nref_updates++;
461 	ref = NULL;
462 	ref_update = NULL;
463 done:
464 	if (ref)
465 		got_ref_close(ref);
466 	free(ref_update);
467 	free(refname);
468 	free(id);
469 	return err;
470 }
471 
472 static const struct got_error *
473 pack_index_progress(void *arg, uint32_t nobj_total, uint32_t nobj_indexed,
474     uint32_t nobj_loose, uint32_t nobj_resolved)
475 {
476 	int p_indexed = 0, p_resolved = 0;
477 	int nobj_delta = nobj_total - nobj_loose;
478 
479 	if (nobj_total > 0)
480 		p_indexed = (nobj_indexed * 100) / nobj_total;
481 
482 	if (nobj_delta > 0)
483 		p_resolved = (nobj_resolved * 100) / nobj_delta;
484 
485 	if (p_resolved > 0) {
486 		log_debug("indexing %d objects %d%%; resolving %d deltas %d%%",
487 		    nobj_total, p_indexed, nobj_delta, p_resolved);
488 	} else
489 		log_debug("indexing %d objects %d%%", nobj_total, p_indexed);
490 
491 	return NULL;
492 }
493 
494 static const struct got_error *
495 read_more_pack_stream(int infd, BUF *buf, size_t minsize)
496 {
497 	const struct got_error *err = NULL;
498 	uint8_t readahead[65536];
499 	size_t have, newlen;
500 
501 	err = got_poll_read_full(infd, &have,
502 	    readahead, sizeof(readahead), minsize);
503 	if (err)
504 		return err;
505 
506 	err = buf_append(&newlen, buf, readahead, have);
507 	if (err)
508 		return err;
509 	return NULL;	
510 }
511 
512 static const struct got_error *
513 copy_object_type_and_size(uint8_t *type, uint64_t *size, int infd, int outfd,
514     off_t *outsize, BUF *buf, size_t *buf_pos, SHA1_CTX *ctx)
515 {
516 	const struct got_error *err = NULL;
517 	uint8_t t = 0;
518 	uint64_t s = 0;
519 	uint8_t sizebuf[8];
520 	size_t i = 0;
521 	off_t obj_offset = *outsize;
522 
523 	do {
524 		/* We do not support size values which don't fit in 64 bit. */
525 		if (i > 9)
526 			return got_error_fmt(GOT_ERR_OBJ_TOO_LARGE,
527 			    "packfile offset %llu", obj_offset);
528 
529 		if (buf_len(buf) - *buf_pos < sizeof(sizebuf[0])) {
530 			err = read_more_pack_stream(infd, buf,
531 			    sizeof(sizebuf[0]));
532 			if (err)
533 				return err;
534 		}
535 
536 		sizebuf[i] = buf_getc(buf, *buf_pos);
537 		*buf_pos += sizeof(sizebuf[i]);
538 
539 		if (i == 0) {
540 			t = (sizebuf[i] & GOT_PACK_OBJ_SIZE0_TYPE_MASK) >>
541 			    GOT_PACK_OBJ_SIZE0_TYPE_MASK_SHIFT;
542 			s = (sizebuf[i] & GOT_PACK_OBJ_SIZE0_VAL_MASK);
543 		} else {
544 			size_t shift = 4 + 7 * (i - 1);
545 			s |= ((sizebuf[i] & GOT_PACK_OBJ_SIZE_VAL_MASK) <<
546 			    shift);
547 		}
548 		i++;
549 	} while (sizebuf[i - 1] & GOT_PACK_OBJ_SIZE_MORE);
550 
551 	err = got_pack_hwrite(outfd, sizebuf, i, ctx);
552 	if (err)
553 		return err;
554 	*outsize += i;
555 
556 	*type = t;
557 	*size = s;
558 	return NULL;
559 }
560 
561 static const struct got_error *
562 copy_ref_delta(int infd, int outfd, off_t *outsize, BUF *buf, size_t *buf_pos,
563     SHA1_CTX *ctx)
564 {
565 	const struct got_error *err = NULL;
566 	size_t remain = buf_len(buf) - *buf_pos;
567 
568 	if (remain < SHA1_DIGEST_LENGTH) {
569 		err = read_more_pack_stream(infd, buf,
570 		    SHA1_DIGEST_LENGTH - remain);
571 		if (err)
572 			return err;
573 	}
574 
575 	err = got_pack_hwrite(outfd, buf_get(buf) + *buf_pos,
576 	    SHA1_DIGEST_LENGTH, ctx);
577 	if (err)
578 		return err;
579 
580 	*buf_pos += SHA1_DIGEST_LENGTH;
581 	return NULL;
582 }
583 
584 static const struct got_error *
585 copy_offset_delta(int infd, int outfd, off_t *outsize, BUF *buf, size_t *buf_pos,
586     SHA1_CTX *ctx)
587 {
588 	const struct got_error *err = NULL;
589 	uint64_t o = 0;
590 	uint8_t offbuf[8];
591 	size_t i = 0;
592 	off_t obj_offset = *outsize;
593 
594 	do {
595 		/* We do not support offset values which don't fit in 64 bit. */
596 		if (i > 8)
597 			return got_error_fmt(GOT_ERR_OBJ_TOO_LARGE,
598 			    "packfile offset %llu", obj_offset);
599 
600 		if (buf_len(buf) - *buf_pos < sizeof(offbuf[0])) {
601 			err = read_more_pack_stream(infd, buf,
602 			    sizeof(offbuf[0]));
603 			if (err)
604 				return err;
605 		}
606 
607 		offbuf[i] = buf_getc(buf, *buf_pos);
608 		*buf_pos += sizeof(offbuf[i]);
609 
610 		if (i == 0)
611 			o = (offbuf[i] & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
612 		else {
613 			o++;
614 			o <<= 7;
615 			o += (offbuf[i] & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
616 		}
617 		i++;
618 	} while (offbuf[i - 1] & GOT_PACK_OBJ_DELTA_OFF_MORE);
619 
620 	if (o < sizeof(struct got_packfile_hdr) || o > *outsize)
621 		return got_error(GOT_ERR_PACK_OFFSET);
622 
623 	err = got_pack_hwrite(outfd, offbuf, i, ctx);
624 	if (err)
625 		return err;
626 
627 	*outsize += i;
628 	return NULL;
629 }
630 
631 static const struct got_error *
632 copy_zstream(int infd, int outfd, off_t *outsize, BUF *buf, size_t *buf_pos,
633     SHA1_CTX *ctx)
634 {
635 	const struct got_error *err = NULL;
636 	z_stream z;
637 	int zret;
638 	char voidbuf[1024];
639 	size_t consumed_total = 0;
640 	off_t zstream_offset = *outsize;
641 
642 	memset(&z, 0, sizeof(z));
643 
644 	z.zalloc = Z_NULL;
645 	z.zfree = Z_NULL;
646 	zret = inflateInit(&z);
647 	if (zret != Z_OK) {
648 		if  (zret == Z_ERRNO)
649 			return got_error_from_errno("inflateInit");
650 		if  (zret == Z_MEM_ERROR) {
651 			errno = ENOMEM;
652 			return got_error_from_errno("inflateInit");
653 		}
654 		return got_error_msg(GOT_ERR_DECOMPRESSION,
655 		    "inflateInit failed");
656 	}
657 
658 	while (zret != Z_STREAM_END) {
659 		size_t last_total_in, consumed;
660 
661 		/*
662 		 * Decompress into the void. Object data will be parsed
663 		 * later, when the pack file is indexed. For now, we just
664 		 * want to locate the end of the compressed stream.
665 		 */
666 		while (zret != Z_STREAM_END && buf_len(buf) - *buf_pos > 0) {
667 			last_total_in = z.total_in;
668 			z.next_in = buf_get(buf) + *buf_pos;
669 			z.avail_in = buf_len(buf) - *buf_pos;
670 			z.next_out = voidbuf;
671 			z.avail_out = sizeof(voidbuf);
672 
673 			zret = inflate(&z, Z_SYNC_FLUSH);
674 			if (zret != Z_OK && zret != Z_BUF_ERROR &&
675 			    zret != Z_STREAM_END) {
676 				err = got_error_fmt(GOT_ERR_DECOMPRESSION,
677 				    "packfile offset %llu", zstream_offset);
678 				goto done;
679 			}
680 			consumed = z.total_in - last_total_in;
681 
682 			err = got_pack_hwrite(outfd, buf_get(buf) + *buf_pos,
683 			    consumed, ctx);
684 			if (err)
685 				goto done;
686 
687 			err = buf_discard(buf, *buf_pos + consumed);
688 			if (err)
689 				goto done;
690 			*buf_pos = 0;
691 
692 			consumed_total += consumed;
693 		}
694 
695 		if (zret != Z_STREAM_END) {
696 			err = read_more_pack_stream(infd, buf, 1);
697 			if (err)
698 				goto done;
699 		}
700 	}
701 
702 	if (err == NULL)
703 		*outsize += consumed_total;
704 done:
705 	inflateEnd(&z);
706 	return err;
707 }
708 
709 static const struct got_error *
710 validate_object_type(int obj_type)
711 {
712 	switch (obj_type) {
713 	case GOT_OBJ_TYPE_BLOB:
714 	case GOT_OBJ_TYPE_COMMIT:
715 	case GOT_OBJ_TYPE_TREE:
716 	case GOT_OBJ_TYPE_TAG:
717 	case GOT_OBJ_TYPE_REF_DELTA:
718 	case GOT_OBJ_TYPE_OFFSET_DELTA:
719 		return NULL;
720 	default:
721 		break;
722 	}
723 
724 	return got_error(GOT_ERR_OBJ_TYPE);
725 }
726 
727 static const struct got_error *
728 recv_packdata(off_t *outsize, uint8_t *sha1, int infd, int outfd)
729 {
730 	const struct got_error *err;
731 	struct got_packfile_hdr hdr;
732 	size_t have;
733 	uint32_t nobj, nhave = 0;
734 	SHA1_CTX ctx;
735 	uint8_t expected_sha1[SHA1_DIGEST_LENGTH];
736 	char hex[SHA1_DIGEST_STRING_LENGTH];
737 	BUF *buf = NULL;
738 	size_t buf_pos = 0, remain;
739 	ssize_t w;
740 
741 	*outsize = 0;
742 	SHA1Init(&ctx);
743 
744 	err = got_poll_read_full(infd, &have, &hdr, sizeof(hdr), sizeof(hdr));
745 	if (err)
746 		return err;
747 	if (have != sizeof(hdr))
748 		return got_error_msg(GOT_ERR_BAD_PACKFILE, "short pack file");
749 	*outsize += have;
750 
751 	if (hdr.signature != htobe32(GOT_PACKFILE_SIGNATURE))
752 		return got_error_msg(GOT_ERR_BAD_PACKFILE,
753 		    "bad packfile signature");
754 	if (hdr.version != htobe32(GOT_PACKFILE_VERSION))
755 		return got_error_msg(GOT_ERR_BAD_PACKFILE,
756 		    "bad packfile version");
757 
758 	nobj = be32toh(hdr.nobjects);
759 	if (nobj == 0)
760 		return got_error_msg(GOT_ERR_BAD_PACKFILE,
761 		    "bad packfile with zero objects");
762 
763 	log_debug("expecting %d objects", nobj);
764 
765 	err = got_pack_hwrite(outfd, &hdr, sizeof(hdr), &ctx);
766 	if (err)
767 		return err;
768 
769 	err = buf_alloc(&buf, 65536);
770 	if (err)
771 		return err;
772 
773 	while (nhave != nobj) {
774 		uint8_t obj_type;
775 		uint64_t obj_size;
776 
777 		err = copy_object_type_and_size(&obj_type, &obj_size,
778 		    infd, outfd, outsize, buf, &buf_pos, &ctx);
779 		if (err)
780 			goto done;
781 
782 		err = validate_object_type(obj_type);
783 		if (err)
784 			goto done;
785 
786 		if (obj_type == GOT_OBJ_TYPE_REF_DELTA) {
787 			err = copy_ref_delta(infd, outfd, outsize,
788 			    buf, &buf_pos, &ctx);
789 			if (err)
790 				goto done;
791 		} else if (obj_type == GOT_OBJ_TYPE_OFFSET_DELTA) {
792 			err = copy_offset_delta(infd, outfd, outsize,
793 			    buf, &buf_pos, &ctx);
794 			if (err)
795 				goto done;
796 		}
797 
798 		err = copy_zstream(infd, outfd, outsize, buf, &buf_pos, &ctx);
799 		if (err)
800 			goto done;
801 
802 		nhave++;
803 	}
804 
805 	log_debug("received %u objects", nobj);
806 
807 	SHA1Final(expected_sha1, &ctx);
808 
809 	remain = buf_len(buf) - buf_pos;
810 	if (remain < SHA1_DIGEST_LENGTH) {
811 		err = read_more_pack_stream(infd, buf,
812 		    SHA1_DIGEST_LENGTH - remain);
813 		if (err)
814 			return err;
815 	}
816 
817 	got_sha1_digest_to_str(expected_sha1, hex, sizeof(hex));
818 	log_debug("expect SHA1: %s", hex);
819 	got_sha1_digest_to_str(buf_get(buf) + buf_pos, hex, sizeof(hex));
820 	log_debug("actual SHA1: %s", hex);
821 
822 	if (memcmp(buf_get(buf) + buf_pos, expected_sha1,
823 	    SHA1_DIGEST_LENGTH) != 0) {
824 		err = got_error(GOT_ERR_PACKFILE_CSUM);
825 		goto done;
826 	}
827 
828 	memcpy(sha1, expected_sha1, SHA1_DIGEST_LENGTH);
829 
830 	w = write(outfd, expected_sha1, SHA1_DIGEST_LENGTH);
831 	if (w == -1) {
832 		err = got_error_from_errno("write");
833 		goto done;
834 	}
835 	if (w != SHA1_DIGEST_LENGTH) {
836 		err = got_error(GOT_ERR_IO);
837 		goto done;
838 	}
839 
840 	*outsize += SHA1_DIGEST_LENGTH;
841 
842 	if (fsync(outfd) == -1) {
843 		err = got_error_from_errno("fsync");
844 		goto done;
845 	}
846 	if (lseek(outfd, 0L, SEEK_SET) == -1) {
847 		err = got_error_from_errno("lseek");
848 		goto done;
849 	}
850 done:
851 	buf_free(buf);
852 	return err;
853 }
854 
855 static const struct got_error *
856 report_pack_status(struct repo_write_client *client,
857     const struct got_error *unpack_err)
858 {
859 	const struct got_error *err = NULL;
860 	struct gotd_imsg_packfile_status istatus;
861 	struct ibuf *wbuf;
862 	struct imsgbuf ibuf;
863 	const char *unpack_ok = "unpack ok\n";
864 	size_t len;
865 	
866 	imsg_init(&ibuf, client->fd);
867 
868 	if (unpack_err)
869 		istatus.reason_len = strlen(unpack_err->msg);
870 	else
871 		istatus.reason_len = strlen(unpack_ok);
872 
873 	len = sizeof(istatus) + istatus.reason_len;
874 	wbuf = imsg_create(&ibuf, GOTD_IMSG_PACKFILE_STATUS, PROC_REPO_WRITE,
875 	    repo_write.pid, len);
876 	if (wbuf == NULL) {
877 		err = got_error_from_errno("imsg_create PACKFILE_STATUS");
878 		goto done;
879 	}
880 
881 	if (imsg_add(wbuf, &istatus, sizeof(istatus)) == -1) {
882 		err = got_error_from_errno("imsg_add PACKFILE_STATUS");
883 		goto done;
884 	}
885 
886 	if (imsg_add(wbuf, err ? err->msg : unpack_ok,
887 	    istatus.reason_len) == -1) {
888 		err = got_error_from_errno("imsg_add PACKFILE_STATUS");
889 		goto done;
890 	}
891 
892 	wbuf->fd = -1;
893 	imsg_close(&ibuf, wbuf);
894 
895 	err = gotd_imsg_flush(&ibuf);
896 done:
897 	imsg_clear(&ibuf);
898 	return err;
899 }
900 
901 static const struct got_error *
902 recv_packfile(struct repo_write_client **client, struct imsg *imsg)
903 {
904 	const struct got_error *err = NULL, *unpack_err;
905 	struct gotd_imsg_recv_packfile ireq;
906 	FILE *tempfiles[3] = { NULL, NULL, NULL };
907 	struct repo_tempfile {
908 		int fd;
909 		int idx;
910 	} repo_tempfiles[3] = { { - 1, - 1 }, { - 1, - 1 }, { - 1, - 1 }, };
911 	int i;
912 	size_t datalen;
913 	struct imsgbuf ibuf;
914 	struct got_ratelimit rl;
915 	struct got_pack *pack = NULL;
916 	off_t pack_filesize = 0;
917 
918 	log_debug("packfile request received");
919 
920 	got_ratelimit_init(&rl, 2, 0);
921 
922 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
923 	if (datalen != sizeof(ireq))
924 		return got_error(GOT_ERR_PRIVSEP_LEN);
925 	memcpy(&ireq, imsg->data, sizeof(ireq));
926 
927 	*client = find_client(ireq.client_id);
928 	if (*client == NULL || STAILQ_EMPTY(&(*client)->ref_updates))
929 		return got_error(GOT_ERR_CLIENT_ID);
930 
931 	if ((*client)->pack_pipe[0] == -1 ||
932 	    (*client)->pack_pipe[1] == -1 ||
933 	    (*client)->packidx_fd == -1)
934 		return got_error(GOT_ERR_PRIVSEP_NO_FD);
935 
936 	imsg_init(&ibuf, (*client)->fd);
937 
938 	if (imsg->fd == -1)
939 		return got_error(GOT_ERR_PRIVSEP_NO_FD);
940 
941 	pack = &(*client)->pack;
942 	memset(pack, 0, sizeof(*pack));
943 	pack->fd = imsg->fd;
944 	err = got_delta_cache_alloc(&pack->delta_cache);
945 	if (err)
946 		return err;
947 
948 	for (i = 0; i < nitems(repo_tempfiles); i++) {
949 		struct repo_tempfile *t = &repo_tempfiles[i];
950 		err = got_repo_temp_fds_get(&t->fd, &t->idx, repo_write.repo);
951 		if (err)
952 			goto done;
953 	}
954 
955 	for (i = 0; i < nitems(tempfiles); i++) {
956 		int fd = dup(repo_tempfiles[i].fd);
957 		FILE *f;
958 		if (fd == -1) {
959 			err = got_error_from_errno("dup");
960 			goto done;
961 		}
962 		f = fdopen(fd, "w+");
963 		if (f == NULL) {
964 			err = got_error_from_errno("dup");
965 			close(fd);
966 			goto done;
967 		}
968 		tempfiles[i] = f;
969 	}
970 
971 	/* Send pack file pipe to gotsh(1). */
972 	if (imsg_compose(&ibuf, GOTD_IMSG_RECV_PACKFILE, PROC_REPO_WRITE,
973 	    repo_write.pid, (*client)->pack_pipe[1], NULL, 0) == -1) {
974 		(*client)->pack_pipe[1] = -1;
975 		err = got_error_from_errno("imsg_compose ACK");
976 		if (err)	
977 			goto done;
978 	}
979 	(*client)->pack_pipe[1] = -1;
980 	err = gotd_imsg_flush(&ibuf);
981 	if (err)
982 		goto done;
983 
984 	log_debug("receiving pack data");
985 	unpack_err = recv_packdata(&pack_filesize, (*client)->pack_sha1,
986 	    (*client)->pack_pipe[0], pack->fd);
987 	if (ireq.report_status) {
988 		err = report_pack_status(*client, unpack_err);
989 		if (err) {
990 			/* Git clients hang up after sending the pack file. */
991 			if (err->code == GOT_ERR_EOF)
992 				err = NULL;
993 		}
994 	}
995 	if (unpack_err)
996 		err = unpack_err;
997 	if (err)
998 		goto done;
999 
1000 	log_debug("pack data received");
1001 
1002 	/* XXX size_t vs off_t, both should be off_t */
1003 	if (pack_filesize >= SIZE_MAX) {
1004 		err = got_error_msg(GOT_ERR_BAD_PACKFILE,
1005 		    "pack file too large");
1006 		goto done;
1007 	}
1008 	pack->filesize = pack_filesize;
1009 
1010 	log_debug("begin indexing pack (%zu bytes in size)", pack->filesize);
1011 	err = got_pack_index(pack, (*client)->packidx_fd,
1012 	    tempfiles[0], tempfiles[1], tempfiles[2], (*client)->pack_sha1,
1013 	    pack_index_progress, NULL, &rl);
1014 	if (err)
1015 		goto done;
1016 	log_debug("done indexing pack");
1017 
1018 	if (fsync((*client)->packidx_fd) == -1) {
1019 		err = got_error_from_errno("fsync");
1020 		goto done;
1021 	}
1022 	if (lseek((*client)->packidx_fd, 0L, SEEK_SET) == -1)
1023 		err = got_error_from_errno("lseek");
1024 done:
1025 	if (close((*client)->pack_pipe[0]) == -1 && err == NULL)
1026 		err = got_error_from_errno("close");
1027 	(*client)->pack_pipe[0] = -1;
1028 	for (i = 0; i < nitems(repo_tempfiles); i++) {
1029 		struct repo_tempfile *t = &repo_tempfiles[i];
1030 		if (t->idx != -1)
1031 			got_repo_temp_fds_put(t->idx, repo_write.repo);
1032 	}
1033 	for (i = 0; i < nitems(tempfiles); i++) {
1034 		if (tempfiles[i] && fclose(tempfiles[i]) == EOF && err == NULL)
1035 			err = got_error_from_errno("fclose");
1036 	}
1037 	if (err)
1038 		got_pack_close(pack);
1039 	imsg_clear(&ibuf);
1040 	return err;
1041 }
1042 
1043 static const struct got_error *
1044 verify_packfile(struct repo_write_client *client)
1045 {
1046 	const struct got_error *err = NULL, *close_err;
1047 	struct gotd_ref_update *ref_update;
1048 	struct got_packidx *packidx = NULL;
1049 	struct stat sb;
1050 	char *id_str = NULL;
1051 	int idx = -1;
1052 
1053 	if (STAILQ_EMPTY(&client->ref_updates)) {
1054 		return got_error_msg(GOT_ERR_BAD_REQUEST,
1055 		    "cannot verify pack file without any ref-updates");
1056 	}
1057 
1058 	if (client->pack.fd == -1) {
1059 		return got_error_msg(GOT_ERR_BAD_REQUEST,
1060 		    "invalid pack file handle during pack verification");
1061 	}
1062 	if (client->packidx_fd == -1) {
1063 		return got_error_msg(GOT_ERR_BAD_REQUEST,
1064 		    "invalid pack index handle during pack verification");
1065 	}
1066 
1067 	if (fstat(client->packidx_fd, &sb) == -1)
1068 		return got_error_from_errno("pack index fstat");
1069 
1070 	packidx = malloc(sizeof(*packidx));
1071 	memset(packidx, 0, sizeof(*packidx));
1072 	packidx->fd = client->packidx_fd;
1073 	client->packidx_fd = -1;
1074 	packidx->len = sb.st_size;
1075 	
1076 	err = got_packidx_init_hdr(packidx, 1, client->pack.filesize);
1077 	if (err)
1078 		return err;
1079 
1080 	STAILQ_FOREACH(ref_update, &client->ref_updates, entry) {
1081 		err = got_object_id_str(&id_str, &ref_update->new_id);
1082 		if (err)
1083 			goto done;
1084 
1085 		idx = got_packidx_get_object_idx(packidx, &ref_update->new_id);
1086 		if (idx == -1) {
1087 			err = got_error_fmt(GOT_ERR_BAD_PACKFILE,
1088 			    "advertised object %s is missing from pack file",
1089 			    id_str);
1090 			goto done;
1091 		}
1092 	}
1093 
1094 done:	
1095 	close_err = got_packidx_close(packidx);
1096 	if (close_err && err == NULL)
1097 		err = close_err;
1098 	free(id_str);
1099 	return err;
1100 }
1101 
1102 static const struct got_error *
1103 install_packfile(struct repo_write_client *client, struct gotd_imsgev *iev)
1104 {
1105 	struct gotd_imsg_packfile_install inst;
1106 	int ret;
1107 
1108 	memset(&inst, 0, sizeof(inst));
1109 	inst.client_id = client->id;
1110 	memcpy(inst.pack_sha1, client->pack_sha1, SHA1_DIGEST_LENGTH);
1111 
1112 	ret = gotd_imsg_compose_event(iev, GOTD_IMSG_PACKFILE_INSTALL,
1113 	    PROC_REPO_WRITE, -1, &inst, sizeof(inst));
1114 	if (ret == -1)
1115 		return got_error_from_errno("imsg_compose PACKFILE_INSTALL");
1116 
1117 	return NULL;
1118 }
1119 
1120 static const struct got_error *
1121 send_ref_updates_start(struct repo_write_client *client, int nref_updates,
1122     struct gotd_imsgev *iev)
1123 {
1124 	struct gotd_imsg_ref_updates_start istart;
1125 	int ret;
1126 
1127 	memset(&istart, 0, sizeof(istart));
1128 	istart.nref_updates = nref_updates;
1129 	istart.client_id = client->id;
1130 
1131 	ret = gotd_imsg_compose_event(iev, GOTD_IMSG_REF_UPDATES_START,
1132 	    PROC_REPO_WRITE, -1, &istart, sizeof(istart));
1133 	if (ret == -1)
1134 		return got_error_from_errno("imsg_compose REF_UPDATES_START");
1135 
1136 	return NULL;
1137 }
1138 
1139 
1140 static const struct got_error *
1141 send_ref_update(struct repo_write_client *client,
1142     struct gotd_ref_update *ref_update, struct gotd_imsgev *iev)
1143 {
1144 	struct gotd_imsg_ref_update iref;
1145 	const char *refname = got_ref_get_name(ref_update->ref);
1146 	struct ibuf *wbuf;
1147 	size_t len;
1148 
1149 	memset(&iref, 0, sizeof(iref));
1150 	memcpy(iref.old_id, ref_update->old_id.sha1, SHA1_DIGEST_LENGTH);
1151 	memcpy(iref.new_id, ref_update->new_id.sha1, SHA1_DIGEST_LENGTH);
1152 	iref.ref_is_new = ref_update->ref_is_new;
1153 	iref.client_id = client->id;
1154 	iref.name_len = strlen(refname);
1155 
1156 	len = sizeof(iref) + iref.name_len;
1157 	wbuf = imsg_create(&iev->ibuf, GOTD_IMSG_REF_UPDATE, PROC_REPO_WRITE,
1158 	    repo_write.pid, len);
1159 	if (wbuf == NULL)
1160 		return got_error_from_errno("imsg_create REF_UPDATE");
1161 
1162 	if (imsg_add(wbuf, &iref, sizeof(iref)) == -1)
1163 		return got_error_from_errno("imsg_add REF_UPDATE");
1164 	if (imsg_add(wbuf, refname, iref.name_len) == -1)
1165 		return got_error_from_errno("imsg_add REF_UPDATE");
1166 
1167 	wbuf->fd = -1;
1168 	imsg_close(&iev->ibuf, wbuf);
1169 
1170 	gotd_imsg_event_add(iev);
1171 	return NULL;
1172 }
1173 
1174 static const struct got_error *
1175 update_refs(struct repo_write_client *client, struct gotd_imsgev *iev)
1176 {
1177 	const struct got_error *err = NULL;
1178 	struct gotd_ref_update *ref_update;
1179 
1180 	err = send_ref_updates_start(client, client->nref_updates, iev);
1181 	if (err)
1182 		return err;
1183 
1184 	STAILQ_FOREACH(ref_update, &client->ref_updates, entry) {
1185 		err = send_ref_update(client, ref_update, iev);
1186 		if (err)
1187 			goto done;
1188 	}
1189 done:
1190 	return err;
1191 }
1192 
1193 static const struct got_error *
1194 recv_disconnect(struct imsg *imsg)
1195 {
1196 	const struct got_error *err = NULL;
1197 	struct gotd_imsg_disconnect idisconnect;
1198 	size_t datalen;
1199 	int client_fd = -1, pipe0 = -1, pipe1 = - 1, idxfd = -1;
1200 	struct repo_write_client *client = NULL;
1201 	uint64_t slot;
1202 
1203 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1204 	if (datalen != sizeof(idisconnect))
1205 		return got_error(GOT_ERR_PRIVSEP_LEN);
1206 	memcpy(&idisconnect, imsg->data, sizeof(idisconnect));
1207 
1208 	log_debug("client disconnecting");
1209 
1210 	client = find_client(idisconnect.client_id);
1211 	if (client == NULL)
1212 		return got_error(GOT_ERR_CLIENT_ID);
1213 
1214 	slot = client_hash(client->id) % nitems(repo_write_clients);
1215 	STAILQ_REMOVE(&repo_write_clients[slot], client, repo_write_client,
1216 	    entry);
1217 	while (!STAILQ_EMPTY(&client->ref_updates)) {
1218 		struct gotd_ref_update *ref_update;
1219 		ref_update = STAILQ_FIRST(&client->ref_updates);
1220 		STAILQ_REMOVE_HEAD(&client->ref_updates, entry);
1221 		got_ref_close(ref_update->ref);
1222 		free(ref_update);
1223 	}
1224 	err = got_pack_close(&client->pack);
1225 	client_fd = client->fd;
1226 	pipe0 = client->pack_pipe[0];
1227 	pipe1 = client->pack_pipe[1];
1228 	idxfd = client->packidx_fd;
1229 	free(client);
1230 	if (client_fd != -1 && close(client_fd) == -1)
1231 		err = got_error_from_errno("close");
1232 	if (pipe0 != -1 && close(pipe0) == -1 && err == NULL)
1233 		err = got_error_from_errno("close");
1234 	if (pipe1 != -1 && close(pipe1) == -1 && err == NULL)
1235 		err = got_error_from_errno("close");
1236 	if (idxfd != -1 && close(idxfd) == -1 && err == NULL)
1237 		err = got_error_from_errno("close");
1238 	return err;
1239 }
1240 
1241 static const struct got_error *
1242 receive_pack_pipe(struct repo_write_client **client, struct imsg *imsg,
1243     struct gotd_imsgev *iev)
1244 {
1245 	struct gotd_imsg_packfile_pipe ireq;
1246 	size_t datalen;
1247 
1248 	log_debug("receving pack pipe descriptor");
1249 
1250 	if (imsg->fd == -1)
1251 		return got_error(GOT_ERR_PRIVSEP_NO_FD);
1252 
1253 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1254 	if (datalen != sizeof(ireq))
1255 		return got_error(GOT_ERR_PRIVSEP_LEN);
1256 	memcpy(&ireq, imsg->data, sizeof(ireq));
1257 
1258 	*client = find_client(ireq.client_id);
1259 	if (*client == NULL)
1260 		return got_error(GOT_ERR_CLIENT_ID);
1261 	if ((*client)->pack_pipe[1] != -1)
1262 		return got_error(GOT_ERR_PRIVSEP_MSG);
1263 
1264 	if ((*client)->pack_pipe[0] == -1)
1265 		(*client)->pack_pipe[0] = imsg->fd;
1266 	else
1267 		(*client)->pack_pipe[1] = imsg->fd;
1268 
1269 	return NULL;
1270 }
1271 
1272 static const struct got_error *
1273 receive_pack_idx(struct repo_write_client **client, struct imsg *imsg,
1274     struct gotd_imsgev *iev)
1275 {
1276 	struct gotd_imsg_packidx_file ireq;
1277 	size_t datalen;
1278 
1279 	log_debug("receving pack index output file");
1280 
1281 	if (imsg->fd == -1)
1282 		return got_error(GOT_ERR_PRIVSEP_NO_FD);
1283 
1284 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1285 	if (datalen != sizeof(ireq))
1286 		return got_error(GOT_ERR_PRIVSEP_LEN);
1287 	memcpy(&ireq, imsg->data, sizeof(ireq));
1288 
1289 	*client = find_client(ireq.client_id);
1290 	if (*client == NULL)
1291 		return got_error(GOT_ERR_CLIENT_ID);
1292 	if ((*client)->packidx_fd != -1)
1293 		return got_error(GOT_ERR_PRIVSEP_MSG);
1294 
1295 	(*client)->packidx_fd = imsg->fd;
1296 	return NULL;
1297 }
1298 
1299 static void
1300 repo_write_dispatch(int fd, short event, void *arg)
1301 {
1302 	const struct got_error *err = NULL;
1303 	struct gotd_imsgev *iev = arg;
1304 	struct imsgbuf *ibuf = &iev->ibuf;
1305 	struct imsg imsg;
1306 	struct repo_write_client *client = NULL;
1307 	ssize_t n;
1308 	int shut = 0;
1309 
1310 	if (event & EV_READ) {
1311 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1312 			fatal("imsg_read error");
1313 		if (n == 0)	/* Connection closed. */
1314 			shut = 1;
1315 	}
1316 
1317 	if (event & EV_WRITE) {
1318 		n = msgbuf_write(&ibuf->w);
1319 		if (n == -1 && errno != EAGAIN)
1320 			fatal("msgbuf_write");
1321 		if (n == 0)	/* Connection closed. */
1322 			shut = 1;
1323 	}
1324 
1325 	for (;;) {
1326 		if ((n = imsg_get(ibuf, &imsg)) == -1)
1327 			fatal("%s: imsg_get error", __func__);
1328 		if (n == 0)	/* No more messages. */
1329 			break;
1330 
1331 		switch (imsg.hdr.type) {
1332 		case GOTD_IMSG_LIST_REFS_INTERNAL:
1333 			err = list_refs(&client, &imsg);
1334 			if (err)
1335 				log_warnx("%s: ls-refs: %s", repo_write.title,
1336 				    err->msg);
1337 			break;
1338 		case GOTD_IMSG_REF_UPDATE:
1339 			err = recv_ref_update(&client, &imsg);
1340 			if (err)
1341 				log_warnx("%s: ref-update: %s",
1342 				    repo_write.title, err->msg);
1343 			break;
1344 		case GOTD_IMSG_PACKFILE_PIPE:
1345 			err = receive_pack_pipe(&client, &imsg, iev);
1346 			if (err) {
1347 				log_warnx("%s: receiving pack pipe: %s",
1348 				    repo_write.title, err->msg);
1349 				break;
1350 			}
1351 			break;
1352 		case GOTD_IMSG_PACKIDX_FILE:
1353 			err = receive_pack_idx(&client, &imsg, iev);
1354 			if (err) {
1355 				log_warnx("%s: receiving pack index: %s",
1356 				    repo_write.title, err->msg);
1357 				break;
1358 			}
1359 			break;
1360 		case GOTD_IMSG_RECV_PACKFILE:
1361 			err = recv_packfile(&client, &imsg);
1362 			if (err) {
1363 				log_warnx("%s: receive packfile: %s",
1364 				    repo_write.title, err->msg);
1365 				break;
1366 			}
1367 			err = verify_packfile(client);
1368 			if (err) {
1369 				log_warnx("%s: verify packfile: %s",
1370 				    repo_write.title, err->msg);
1371 				break;
1372 			}
1373 			err = install_packfile(client, iev);
1374 			if (err) {
1375 				log_warnx("%s: install packfile: %s",
1376 				    repo_write.title, err->msg);
1377 				break;
1378 			}
1379 			err = update_refs(client, iev);
1380 			if (err) {
1381 				log_warnx("%s: update refs: %s",
1382 				    repo_write.title, err->msg);
1383 			}
1384 			break;
1385 		case GOTD_IMSG_DISCONNECT:
1386 			err = recv_disconnect(&imsg);
1387 			if (err)
1388 				log_warnx("%s: disconnect: %s",
1389 				    repo_write.title, err->msg);
1390 			break;
1391 		default:
1392 			log_debug("%s: unexpected imsg %d", repo_write.title,
1393 			    imsg.hdr.type);
1394 			break;
1395 		}
1396 
1397 		imsg_free(&imsg);
1398 	}
1399 
1400 	if (!shut && check_cancelled(NULL) == NULL) {
1401 		if (err &&
1402 		    gotd_imsg_send_error_event(iev, PROC_REPO_WRITE,
1403 		        client ? client->id : 0, err) == -1) {
1404 			log_warnx("could not send error to parent: %s",
1405 			    err->msg);
1406 		}
1407 		gotd_imsg_event_add(iev);
1408 	} else {
1409 		/* This pipe is dead. Remove its event handler */
1410 		event_del(&iev->ev);
1411 		event_loopexit(NULL);
1412 	}
1413 }
1414 
1415 void
1416 repo_write_main(const char *title, int *pack_fds, int *temp_fds)
1417 {
1418 	const struct got_error *err = NULL;
1419 	struct gotd_imsgev iev;
1420 
1421 	repo_write.title = title;
1422 	repo_write.pid = getpid();
1423 	repo_write.pack_fds = pack_fds;
1424 	repo_write.temp_fds = temp_fds;
1425 
1426 	arc4random_buf(&clients_hash_key, sizeof(clients_hash_key));
1427 
1428 	/*
1429 	 * Open a repository in the root directory.
1430 	 * We are already in chroot at this point.
1431 	 */
1432 	err = got_repo_open(&repo_write.repo, "/", NULL, pack_fds);
1433 	if (err)
1434 		goto done;
1435 	if (!got_repo_is_bare(repo_write.repo)) {
1436 		err = got_error_msg(GOT_ERR_NOT_GIT_REPO,
1437 		    "bare git repository required");
1438 		goto done;
1439 	}
1440 
1441 	got_repo_temp_fds_set(repo_write.repo, temp_fds);
1442 
1443 	signal(SIGINT, catch_sigint);
1444 	signal(SIGTERM, catch_sigterm);
1445 	signal(SIGPIPE, SIG_IGN);
1446 	signal(SIGHUP, SIG_IGN);
1447 
1448 	imsg_init(&iev.ibuf, GOTD_SOCK_FILENO);
1449 	iev.handler = repo_write_dispatch;
1450 	iev.events = EV_READ;
1451 	iev.handler_arg = NULL;
1452 	event_set(&iev.ev, iev.ibuf.fd, EV_READ, repo_write_dispatch, &iev);
1453 	if (event_add(&iev.ev, NULL) == -1) {
1454 		err = got_error_from_errno("event_add");
1455 		goto done;
1456 	}
1457 
1458 	event_dispatch();
1459 done:
1460 	if (err)
1461 		log_warnx("%s: %s", title, err->msg);
1462 	repo_write_shutdown();
1463 }
1464 
1465 void
1466 repo_write_shutdown(void)
1467 {
1468 	log_debug("%s: shutting down", repo_write.title);
1469 	if (repo_write.repo)
1470 		got_repo_close(repo_write.repo);
1471 	got_repo_pack_fds_close(repo_write.pack_fds);
1472 	got_repo_temp_fds_close(repo_write.pack_fds);
1473 	exit(0);
1474 }