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 <ctype.h>
23 #include <event.h>
24 #include <errno.h>
25 #include <imsg.h>
26 #include <signal.h>
27 #include <siphash.h>
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <limits.h>
32 #include <poll.h>
33 #include <sha1.h>
34 #include <sha2.h>
35 #include <unistd.h>
36 #include <zlib.h>
37 
38 #include "buf.h"
39 
40 #include "got_error.h"
41 #include "got_repository.h"
42 #include "got_object.h"
43 #include "got_reference.h"
44 #include "got_path.h"
45 #include "got_diff.h"
46 #include "got_cancel.h"
47 #include "got_commit_graph.h"
48 #include "got_opentemp.h"
49 
50 #include "got_lib_delta.h"
51 #include "got_lib_delta_cache.h"
52 #include "got_lib_hash.h"
53 #include "got_lib_object.h"
54 #include "got_lib_object_cache.h"
55 #include "got_lib_object_idset.h"
56 #include "got_lib_object_parse.h"
57 #include "got_lib_ratelimit.h"
58 #include "got_lib_pack.h"
59 #include "got_lib_pack_index.h"
60 #include "got_lib_repository.h"
61 #include "got_lib_poll.h"
62 
63 #include "log.h"
64 #include "gotd.h"
65 #include "repo_write.h"
66 
67 #ifndef nitems
68 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
69 #endif
70 
71 static struct repo_write {
72 	pid_t pid;
73 	const char *title;
74 	struct got_repository *repo;
75 	int *pack_fds;
76 	int *temp_fds;
77 	int session_fd;
78 	struct gotd_imsgev session_iev;
79 	struct got_pathlist_head *protected_tag_namespaces;
80 	struct got_pathlist_head *protected_branch_namespaces;
81 	struct got_pathlist_head *protected_branches;
82 	struct {
83 		FILE *f1;
84 		FILE *f2;
85 		int fd1;
86 		int fd2;
87 	} diff;
88 	int refs_listed;
89 } repo_write;
90 
91 struct gotd_ref_update {
92 	STAILQ_ENTRY(gotd_ref_update) entry;
93 	struct got_reference *ref;
94 	int ref_is_new;
95 	int delete_ref;
96 	struct got_object_id old_id;
97 	struct got_object_id new_id;
98 };
99 STAILQ_HEAD(gotd_ref_updates, gotd_ref_update);
100 
101 static struct repo_write_client {
102 	uint32_t			 id;
103 	int				 fd;
104 	int				 pack_pipe;
105 	struct got_pack			 pack;
106 	uint8_t				 pack_sha1[SHA1_DIGEST_LENGTH];
107 	int				 packidx_fd;
108 	struct gotd_ref_updates		 ref_updates;
109 	int				 nref_updates;
110 	int				 nref_del;
111 	int				 nref_new;
112 	int				 nref_move;
113 } repo_write_client;
114 
115 static volatile sig_atomic_t sigint_received;
116 static volatile sig_atomic_t sigterm_received;
117 
118 static void
119 catch_sigint(int signo)
120 {
121 	sigint_received = 1;
122 }
123 
124 static void
125 catch_sigterm(int signo)
126 {
127 	sigterm_received = 1;
128 }
129 
130 static const struct got_error *
131 check_cancelled(void *arg)
132 {
133 	if (sigint_received || sigterm_received)
134 		return got_error(GOT_ERR_CANCELLED);
135 
136 	return NULL;
137 }
138 
139 static const struct got_error *
140 send_peeled_tag_ref(struct got_reference *ref, struct got_object *obj,
141     struct imsgbuf *ibuf)
142 {
143 	const struct got_error *err = NULL;
144 	struct got_tag_object *tag;
145 	size_t namelen, len;
146 	char *peeled_refname = NULL;
147 	struct got_object_id *id;
148 	struct ibuf *wbuf;
149 
150 	err = got_object_tag_open(&tag, repo_write.repo, obj);
151 	if (err)
152 		return err;
153 
154 	if (asprintf(&peeled_refname, "%s^{}", got_ref_get_name(ref)) == -1) {
155 		err = got_error_from_errno("asprintf");
156 		goto done;
157 	}
158 
159 	id = got_object_tag_get_object_id(tag);
160 	namelen = strlen(peeled_refname);
161 
162 	len = sizeof(struct gotd_imsg_ref) + namelen;
163 	if (len > MAX_IMSGSIZE - IMSG_HEADER_SIZE) {
164 		err = got_error(GOT_ERR_NO_SPACE);
165 		goto done;
166 	}
167 
168 	wbuf = imsg_create(ibuf, GOTD_IMSG_REF, PROC_REPO_WRITE,
169 	    repo_write.pid, len);
170 	if (wbuf == NULL) {
171 		err = got_error_from_errno("imsg_create REF");
172 		goto done;
173 	}
174 
175 	/* Keep in sync with struct gotd_imsg_ref definition. */
176 	if (imsg_add(wbuf, id->sha1, SHA1_DIGEST_LENGTH) == -1) {
177 		err = got_error_from_errno("imsg_add REF");
178 		goto done;
179 	}
180 	if (imsg_add(wbuf, &namelen, sizeof(namelen)) == -1) {
181 		err = got_error_from_errno("imsg_add REF");
182 		goto done;
183 	}
184 	if (imsg_add(wbuf, peeled_refname, namelen) == -1) {
185 		err = got_error_from_errno("imsg_add REF");
186 		goto done;
187 	}
188 
189 	imsg_close(ibuf, wbuf);
190 done:
191 	got_object_tag_close(tag);
192 	return err;
193 }
194 
195 static const struct got_error *
196 send_ref(struct got_reference *ref, struct imsgbuf *ibuf)
197 {
198 	const struct got_error *err;
199 	const char *refname = got_ref_get_name(ref);
200 	size_t namelen;
201 	struct got_object_id *id = NULL;
202 	struct got_object *obj = NULL;
203 	size_t len;
204 	struct ibuf *wbuf;
205 
206 	namelen = strlen(refname);
207 
208 	len = sizeof(struct gotd_imsg_ref) + namelen;
209 	if (len > MAX_IMSGSIZE - IMSG_HEADER_SIZE)
210 		return got_error(GOT_ERR_NO_SPACE);
211 
212 	err = got_ref_resolve(&id, repo_write.repo, ref);
213 	if (err)
214 		return err;
215 
216 	wbuf = imsg_create(ibuf, GOTD_IMSG_REF, PROC_REPO_WRITE,
217 	    repo_write.pid, len);
218 	if (wbuf == NULL) {
219 		err = got_error_from_errno("imsg_create REF");
220 		goto done;
221 	}
222 
223 	/* Keep in sync with struct gotd_imsg_ref definition. */
224 	if (imsg_add(wbuf, id->sha1, SHA1_DIGEST_LENGTH) == -1)
225 		return got_error_from_errno("imsg_add REF");
226 	if (imsg_add(wbuf, &namelen, sizeof(namelen)) == -1)
227 		return got_error_from_errno("imsg_add REF");
228 	if (imsg_add(wbuf, refname, namelen) == -1)
229 		return got_error_from_errno("imsg_add REF");
230 
231 	imsg_close(ibuf, wbuf);
232 
233 	err = got_object_open(&obj, repo_write.repo, id);
234 	if (err)
235 		goto done;
236 	if (obj->type == GOT_OBJ_TYPE_TAG)
237 		err = send_peeled_tag_ref(ref, obj, ibuf);
238 done:
239 	if (obj)
240 		got_object_close(obj);
241 	free(id);
242 	return err;
243 }
244 
245 static const struct got_error *
246 list_refs(struct imsg *imsg)
247 {
248 	const struct got_error *err;
249 	struct repo_write_client *client = &repo_write_client;
250 	struct got_reflist_head refs;
251 	struct got_reflist_entry *re;
252 	size_t datalen;
253 	struct gotd_imsg_reflist irefs;
254 	struct imsgbuf ibuf;
255 	int client_fd;
256 
257 	TAILQ_INIT(&refs);
258 
259 	client_fd = imsg_get_fd(imsg);
260 	if (client_fd == -1)
261 		return got_error(GOT_ERR_PRIVSEP_NO_FD);
262 
263 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
264 	if (datalen != 0)
265 		return got_error(GOT_ERR_PRIVSEP_LEN);
266 
267 	if (repo_write.refs_listed) {
268 		return got_error_msg(GOT_ERR_CLIENT_ID,
269 		    "duplicate list-refs request");
270 	}
271 	repo_write.refs_listed = 1;
272 
273 	client->fd = client_fd;
274 	client->nref_updates = 0;
275 	client->nref_del = 0;
276 	client->nref_new = 0;
277 	client->nref_move = 0;
278 
279 	imsg_init(&ibuf, client_fd);
280 
281 	err = got_ref_list(&refs, repo_write.repo, "",
282 	    got_ref_cmp_by_name, NULL);
283 	if (err)
284 		return err;
285 
286 	memset(&irefs, 0, sizeof(irefs));
287 	TAILQ_FOREACH(re, &refs, entry) {
288 		struct got_object_id *id;
289 		int obj_type;
290 
291 		if (got_ref_is_symbolic(re->ref))
292 			continue;
293 
294 		irefs.nrefs++;
295 
296 		/* Account for a peeled tag refs. */
297 		err = got_ref_resolve(&id, repo_write.repo, re->ref);
298 		if (err)
299 			goto done;
300 		err = got_object_get_type(&obj_type, repo_write.repo, id);
301 		free(id);
302 		if (err)
303 			goto done;
304 		if (obj_type == GOT_OBJ_TYPE_TAG)
305 			irefs.nrefs++;
306 	}
307 
308 	if (imsg_compose(&ibuf, GOTD_IMSG_REFLIST, PROC_REPO_WRITE,
309 	    repo_write.pid, -1, &irefs, sizeof(irefs)) == -1) {
310 		err = got_error_from_errno("imsg_compose REFLIST");
311 		goto done;
312 	}
313 
314 	TAILQ_FOREACH(re, &refs, entry) {
315 		if (got_ref_is_symbolic(re->ref))
316 			continue;
317 		err = send_ref(re->ref, &ibuf);
318 		if (err)
319 			goto done;
320 	}
321 
322 	err = gotd_imsg_flush(&ibuf);
323 done:
324 	got_ref_list_free(&refs);
325 	imsg_clear(&ibuf);
326 	return err;
327 }
328 
329 static const struct got_error *
330 validate_namespace(const char *namespace)
331 {
332 	size_t len = strlen(namespace);
333 
334 	if (len < 5 || strncmp("refs/", namespace, 5) != 0 ||
335 	    namespace[len -1] != '/') {
336 		return got_error_fmt(GOT_ERR_BAD_REF_NAME,
337 		    "reference namespace '%s'", namespace);
338 	}
339 
340 	return NULL;
341 }
342 
343 static const struct got_error *
344 protect_ref_namespace(const char *refname, const char *namespace)
345 {
346 	const struct got_error *err;
347 
348 	err = validate_namespace(namespace);
349 	if (err)
350 		return err;
351 
352 	if (strncmp(namespace, refname, strlen(namespace)) == 0)
353 		return got_error_fmt(GOT_ERR_REFS_PROTECTED, "%s", namespace);
354 
355 	return NULL;
356 }
357 
358 static const struct got_error *
359 verify_object_type(struct got_object_id *id, int expected_obj_type,
360     struct got_pack *pack, struct got_packidx *packidx)
361 {
362 	const struct got_error *err;
363 	char hex[SHA1_DIGEST_STRING_LENGTH];
364 	struct got_object *obj;
365 	int idx;
366 	const char *typestr;
367 
368 	idx = got_packidx_get_object_idx(packidx, id);
369 	if (idx == -1) {
370 		got_sha1_digest_to_str(id->sha1, hex, sizeof(hex));
371 		return got_error_fmt(GOT_ERR_BAD_PACKFILE,
372 		    "object %s is missing from pack file", hex);
373 	}
374 
375 	err = got_object_open_from_packfile(&obj, id, pack, packidx,
376 	    idx, repo_write.repo);
377 	if (err)
378 		return err;
379 
380 	if (obj->type != expected_obj_type) {
381 		got_sha1_digest_to_str(id->sha1, hex, sizeof(hex));
382 		got_object_type_label(&typestr, expected_obj_type);
383 		err = got_error_fmt(GOT_ERR_OBJ_TYPE,
384 		    "%s is not pointing at a %s object", hex, typestr);
385 	}
386 	got_object_close(obj);
387 	return err;
388 }
389 
390 static const struct got_error *
391 protect_tag_namespace(const char *namespace, struct got_pack *pack,
392     struct got_packidx *packidx, struct gotd_ref_update *ref_update)
393 {
394 	const struct got_error *err;
395 
396 	err = validate_namespace(namespace);
397 	if (err)
398 		return err;
399 
400 	if (strncmp(namespace, got_ref_get_name(ref_update->ref),
401 	    strlen(namespace)) != 0)
402 		return NULL;
403 
404 	if (!ref_update->ref_is_new)
405 		return got_error_fmt(GOT_ERR_REFS_PROTECTED, "%s", namespace);
406 
407 	return verify_object_type(&ref_update->new_id, GOT_OBJ_TYPE_TAG,
408 	    pack, packidx);
409 }
410 
411 static const struct got_error *
412 protect_require_yca(struct got_object_id *tip_id,
413     size_t max_commits_to_traverse, struct got_pack *pack,
414     struct got_packidx *packidx, struct got_reference *ref)
415 {
416 	const struct got_error *err;
417 	uint8_t *buf = NULL;
418 	size_t len;
419 	struct got_object_id *expected_yca_id = NULL;
420 	struct got_object *obj = NULL;
421 	struct got_commit_object *commit = NULL;
422 	char hex[SHA1_DIGEST_STRING_LENGTH];
423 	const struct got_object_id_queue *parent_ids;
424 	struct got_object_id_queue ids;
425 	struct got_object_qid *pid, *qid;
426 	struct got_object_idset *traversed_set = NULL;
427 	int found_yca = 0, obj_type;
428 
429 	STAILQ_INIT(&ids);
430 
431 	err = got_ref_resolve(&expected_yca_id, repo_write.repo, ref);
432 	if (err)
433 		return err;
434 
435 	err = got_object_get_type(&obj_type, repo_write.repo, expected_yca_id);
436 	if (err)
437 		goto done;
438 
439 	if (obj_type != GOT_OBJ_TYPE_COMMIT) {
440 		got_sha1_digest_to_str(expected_yca_id->sha1, hex, sizeof(hex));
441 		err = got_error_fmt(GOT_ERR_OBJ_TYPE,
442 		    "%s is not pointing at a commit object", hex);
443 		goto done;
444 	}
445 
446 	traversed_set = got_object_idset_alloc();
447 	if (traversed_set == NULL) {
448 		err = got_error_from_errno("got_object_idset_alloc");
449 		goto done;
450 	}
451 
452 	err = got_object_qid_alloc(&qid, tip_id);
453 	if (err)
454 		goto done;
455 	STAILQ_INSERT_TAIL(&ids, qid, entry);
456 	while (!STAILQ_EMPTY(&ids)) {
457 		err = check_cancelled(NULL);
458 		if (err)
459 			break;
460 
461 		qid = STAILQ_FIRST(&ids);
462 		if (got_object_id_cmp(&qid->id, expected_yca_id) == 0) {
463 			found_yca = 1;
464 			break;
465 		}
466 
467 		if (got_object_idset_num_elements(traversed_set) >=
468 		    max_commits_to_traverse)
469 			break;
470 
471 		if (got_object_idset_contains(traversed_set, &qid->id)) {
472 			STAILQ_REMOVE_HEAD(&ids, entry);
473 			got_object_qid_free(qid);
474 			qid = NULL;
475 			continue;
476 		}
477 		err = got_object_idset_add(traversed_set, &qid->id, NULL);
478 		if (err)
479 			goto done;
480 
481 		err = got_object_open(&obj, repo_write.repo, &qid->id);
482 		if (err && err->code != GOT_ERR_NO_OBJ)
483 			goto done;
484 		err = NULL;
485 		if (obj) {
486 			err = got_object_commit_open(&commit, repo_write.repo,
487 			    obj);
488 			if (err)
489 				goto done;
490 		} else {
491 			int idx;
492 
493 			idx = got_packidx_get_object_idx(packidx, &qid->id);
494 			if (idx == -1) {
495 				got_sha1_digest_to_str(qid->id.sha1,
496 				    hex, sizeof(hex));
497 				err = got_error_fmt(GOT_ERR_BAD_PACKFILE,
498 				    "object %s is missing from pack file", hex);
499 				goto done;
500 			}
501 
502 			err = got_object_open_from_packfile(&obj, &qid->id,
503 				pack, packidx, idx, repo_write.repo);
504 			if (err)
505 				goto done;
506 
507 			if (obj->type != GOT_OBJ_TYPE_COMMIT) {
508 				got_sha1_digest_to_str(qid->id.sha1,
509 				    hex, sizeof(hex));
510 				err = got_error_fmt(GOT_ERR_OBJ_TYPE,
511 				    "%s is not pointing at a commit object",
512 				    hex);
513 				goto done;
514 			}
515 
516 			err = got_packfile_extract_object_to_mem(&buf, &len,
517 			    obj, pack);
518 			if (err)
519 				goto done;
520 
521 			err = got_object_parse_commit(&commit, buf, len);
522 			if (err)
523 				goto done;
524 
525 			free(buf);
526 			buf = NULL;
527 		}
528 
529 		got_object_close(obj);
530 		obj = NULL;
531 
532 		STAILQ_REMOVE_HEAD(&ids, entry);
533 		got_object_qid_free(qid);
534 		qid = NULL;
535 
536 		if (got_object_commit_get_nparents(commit) == 0)
537 			break;
538 
539 		parent_ids = got_object_commit_get_parent_ids(commit);
540 		STAILQ_FOREACH(pid, parent_ids, entry) {
541 			err = check_cancelled(NULL);
542 			if (err)
543 				goto done;
544 			err = got_object_qid_alloc(&qid, &pid->id);
545 			if (err)
546 				goto done;
547 			STAILQ_INSERT_TAIL(&ids, qid, entry);
548 			qid = NULL;
549 		}
550 		got_object_commit_close(commit);
551 		commit = NULL;
552 	}
553 
554 	if (!found_yca) {
555 		err = got_error_fmt(GOT_ERR_REF_PROTECTED, "%s",
556 		    got_ref_get_name(ref));
557 	}
558 done:
559 	got_object_idset_free(traversed_set);
560 	got_object_id_queue_free(&ids);
561 	free(buf);
562 	if (obj)
563 		got_object_close(obj);
564 	if (commit)
565 		got_object_commit_close(commit);
566 	free(expected_yca_id);
567 	return err;
568 }
569 
570 static const struct got_error *
571 protect_branch_namespace(const char *namespace, struct got_pack *pack,
572     struct got_packidx *packidx, struct gotd_ref_update *ref_update)
573 {
574 	const struct got_error *err;
575 
576 	err = validate_namespace(namespace);
577 	if (err)
578 		return err;
579 
580 	if (strncmp(namespace, got_ref_get_name(ref_update->ref),
581 	    strlen(namespace)) != 0)
582 		return NULL;
583 
584 	if (ref_update->ref_is_new) {
585 		return verify_object_type(&ref_update->new_id,
586 		    GOT_OBJ_TYPE_COMMIT, pack, packidx);
587 	}
588 
589 	return protect_require_yca(&ref_update->new_id,
590 	    be32toh(packidx->hdr.fanout_table[0xff]), pack, packidx,
591 	    ref_update->ref);
592 }
593 
594 static const struct got_error *
595 protect_branch(const char *refname, struct got_pack *pack,
596     struct got_packidx *packidx, struct gotd_ref_update *ref_update)
597 {
598 	if (strcmp(refname, got_ref_get_name(ref_update->ref)) != 0)
599 		return NULL;
600 
601 	/* Always allow new branches to be created. */
602 	if (ref_update->ref_is_new) {
603 		return verify_object_type(&ref_update->new_id,
604 		    GOT_OBJ_TYPE_COMMIT, pack, packidx);
605 	}
606 
607 	return protect_require_yca(&ref_update->new_id,
608 	    be32toh(packidx->hdr.fanout_table[0xff]), pack, packidx,
609 	    ref_update->ref);
610 }
611 
612 static const struct got_error *
613 recv_ref_update(struct imsg *imsg)
614 {
615 	static const char zero_id[SHA1_DIGEST_LENGTH];
616 	const struct got_error *err = NULL;
617 	struct repo_write_client *client = &repo_write_client;
618 	struct gotd_imsg_ref_update iref;
619 	size_t datalen;
620 	char *refname = NULL;
621 	struct got_reference *ref = NULL;
622 	struct got_object_id *id = NULL;
623 	struct imsgbuf ibuf;
624 	struct gotd_ref_update *ref_update = NULL;
625 
626 	log_debug("ref-update received");
627 
628 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
629 	if (datalen < sizeof(iref))
630 		return got_error(GOT_ERR_PRIVSEP_LEN);
631 	memcpy(&iref, imsg->data, sizeof(iref));
632 	if (datalen != sizeof(iref) + iref.name_len)
633 		return got_error(GOT_ERR_PRIVSEP_LEN);
634 
635 	imsg_init(&ibuf, client->fd);
636 
637 	refname = strndup(imsg->data + sizeof(iref), iref.name_len);
638 	if (refname == NULL)
639 		return got_error_from_errno("strndup");
640 
641 	ref_update = calloc(1, sizeof(*ref_update));
642 	if (ref_update == NULL) {
643 		err = got_error_from_errno("malloc");
644 		goto done;
645 	}
646 
647 	memcpy(ref_update->old_id.sha1, iref.old_id, SHA1_DIGEST_LENGTH);
648 	memcpy(ref_update->new_id.sha1, iref.new_id, SHA1_DIGEST_LENGTH);
649 
650 	err = got_ref_open(&ref, repo_write.repo, refname, 0);
651 	if (err) {
652 		if (err->code != GOT_ERR_NOT_REF)
653 			goto done;
654 		if (memcmp(ref_update->new_id.sha1,
655 		    zero_id, sizeof(zero_id)) == 0) {
656 			err = got_error_fmt(GOT_ERR_BAD_OBJ_ID,
657 			    "%s", refname);
658 			goto done;
659 		}
660 		err = got_ref_alloc(&ref, refname, &ref_update->new_id);
661 		if (err)
662 			goto done;
663 		ref_update->ref_is_new = 1;
664 		client->nref_new++;
665 	}
666 	if (got_ref_is_symbolic(ref)) {
667 		err = got_error_fmt(GOT_ERR_BAD_REF_TYPE,
668 		    "'%s' is a symbolic reference and cannot "
669 		    "be updated", got_ref_get_name(ref));
670 		goto done;
671 	}
672 	if (strncmp("refs/", got_ref_get_name(ref), 5) != 0) {
673 		err = got_error_fmt(GOT_ERR_BAD_REF_NAME,
674 		    "%s: does not begin with 'refs/'",
675 		    got_ref_get_name(ref));
676 		goto done;
677 	}
678 
679 	err = protect_ref_namespace(got_ref_get_name(ref), "refs/got/");
680 	if (err)
681 		goto done;
682 	err = protect_ref_namespace(got_ref_get_name(ref), "refs/remotes/");
683 	if (err)
684 		goto done;
685 
686 	if (!ref_update->ref_is_new) {
687 		/*
688 		 * Ensure the client's idea of this update is still valid.
689 		 * At this point we can only return an error, to prevent
690 		 * the client from uploading a pack file which will likely
691 		 * have to be discarded.
692 		 */
693 		err = got_ref_resolve(&id, repo_write.repo, ref);
694 		if (err)
695 			goto done;
696 
697 		if (got_object_id_cmp(id, &ref_update->old_id) != 0) {
698 			err = got_error_fmt(GOT_ERR_REF_BUSY,
699 			    "%s has been modified by someone else "
700 			    "while transaction was in progress",
701 			    got_ref_get_name(ref));
702 			goto done;
703 		}
704 	}
705 
706 	gotd_imsg_send_ack(&ref_update->new_id, &ibuf, PROC_REPO_WRITE,
707 	    repo_write.pid);
708 
709 	ref_update->ref = ref;
710 	if (memcmp(ref_update->new_id.sha1, zero_id, sizeof(zero_id)) == 0) {
711 		ref_update->delete_ref = 1;
712 		client->nref_del++;
713 	}
714 	STAILQ_INSERT_HEAD(&client->ref_updates, ref_update, entry);
715 	client->nref_updates++;
716 	ref = NULL;
717 	ref_update = NULL;
718 done:
719 	if (ref)
720 		got_ref_close(ref);
721 	free(ref_update);
722 	free(refname);
723 	free(id);
724 	return err;
725 }
726 
727 static const struct got_error *
728 pack_index_progress(void *arg, uint32_t nobj_total, uint32_t nobj_indexed,
729     uint32_t nobj_loose, uint32_t nobj_resolved)
730 {
731 	int p_indexed = 0, p_resolved = 0;
732 	int nobj_delta = nobj_total - nobj_loose;
733 
734 	if (nobj_total > 0)
735 		p_indexed = (nobj_indexed * 100) / nobj_total;
736 
737 	if (nobj_delta > 0)
738 		p_resolved = (nobj_resolved * 100) / nobj_delta;
739 
740 	if (p_resolved > 0) {
741 		log_debug("indexing %d objects %d%%; resolving %d deltas %d%%",
742 		    nobj_total, p_indexed, nobj_delta, p_resolved);
743 	} else
744 		log_debug("indexing %d objects %d%%", nobj_total, p_indexed);
745 
746 	return NULL;
747 }
748 
749 static const struct got_error *
750 read_more_pack_stream(int infd, BUF *buf, size_t minsize)
751 {
752 	const struct got_error *err = NULL;
753 	uint8_t readahead[65536];
754 	size_t have, newlen;
755 
756 	err = got_poll_read_full(infd, &have,
757 	    readahead, sizeof(readahead), minsize);
758 	if (err)
759 		return err;
760 
761 	err = buf_append(&newlen, buf, readahead, have);
762 	if (err)
763 		return err;
764 	return NULL;
765 }
766 
767 static const struct got_error *
768 copy_object_type_and_size(uint8_t *type, uint64_t *size, int infd, int outfd,
769     off_t *outsize, BUF *buf, size_t *buf_pos, struct got_hash *ctx)
770 {
771 	const struct got_error *err = NULL;
772 	uint8_t t = 0;
773 	uint64_t s = 0;
774 	uint8_t sizebuf[8];
775 	size_t i = 0;
776 	off_t obj_offset = *outsize;
777 
778 	do {
779 		/* We do not support size values which don't fit in 64 bit. */
780 		if (i > 9)
781 			return got_error_fmt(GOT_ERR_OBJ_TOO_LARGE,
782 			    "packfile offset %lld", (long long)obj_offset);
783 
784 		if (buf_len(buf) - *buf_pos < sizeof(sizebuf[0])) {
785 			err = read_more_pack_stream(infd, buf,
786 			    sizeof(sizebuf[0]));
787 			if (err)
788 				return err;
789 		}
790 
791 		sizebuf[i] = buf_getc(buf, *buf_pos);
792 		*buf_pos += sizeof(sizebuf[i]);
793 
794 		if (i == 0) {
795 			t = (sizebuf[i] & GOT_PACK_OBJ_SIZE0_TYPE_MASK) >>
796 			    GOT_PACK_OBJ_SIZE0_TYPE_MASK_SHIFT;
797 			s = (sizebuf[i] & GOT_PACK_OBJ_SIZE0_VAL_MASK);
798 		} else {
799 			size_t shift = 4 + 7 * (i - 1);
800 			s |= ((sizebuf[i] & GOT_PACK_OBJ_SIZE_VAL_MASK) <<
801 			    shift);
802 		}
803 		i++;
804 	} while (sizebuf[i - 1] & GOT_PACK_OBJ_SIZE_MORE);
805 
806 	err = got_pack_hwrite(outfd, sizebuf, i, ctx);
807 	if (err)
808 		return err;
809 	*outsize += i;
810 
811 	*type = t;
812 	*size = s;
813 	return NULL;
814 }
815 
816 static const struct got_error *
817 copy_ref_delta(int infd, int outfd, off_t *outsize, BUF *buf, size_t *buf_pos,
818     struct got_hash *ctx)
819 {
820 	const struct got_error *err = NULL;
821 	size_t remain = buf_len(buf) - *buf_pos;
822 
823 	if (remain < SHA1_DIGEST_LENGTH) {
824 		err = read_more_pack_stream(infd, buf,
825 		    SHA1_DIGEST_LENGTH - remain);
826 		if (err)
827 			return err;
828 	}
829 
830 	err = got_pack_hwrite(outfd, buf_get(buf) + *buf_pos,
831 	    SHA1_DIGEST_LENGTH, ctx);
832 	if (err)
833 		return err;
834 
835 	*buf_pos += SHA1_DIGEST_LENGTH;
836 	return NULL;
837 }
838 
839 static const struct got_error *
840 copy_offset_delta(int infd, int outfd, off_t *outsize, BUF *buf, size_t *buf_pos,
841     struct got_hash *ctx)
842 {
843 	const struct got_error *err = NULL;
844 	uint64_t o = 0;
845 	uint8_t offbuf[8];
846 	size_t i = 0;
847 	off_t obj_offset = *outsize;
848 
849 	do {
850 		/* We do not support offset values which don't fit in 64 bit. */
851 		if (i > 8)
852 			return got_error_fmt(GOT_ERR_OBJ_TOO_LARGE,
853 			    "packfile offset %lld", (long long)obj_offset);
854 
855 		if (buf_len(buf) - *buf_pos < sizeof(offbuf[0])) {
856 			err = read_more_pack_stream(infd, buf,
857 			    sizeof(offbuf[0]));
858 			if (err)
859 				return err;
860 		}
861 
862 		offbuf[i] = buf_getc(buf, *buf_pos);
863 		*buf_pos += sizeof(offbuf[i]);
864 
865 		if (i == 0)
866 			o = (offbuf[i] & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
867 		else {
868 			o++;
869 			o <<= 7;
870 			o += (offbuf[i] & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
871 		}
872 		i++;
873 	} while (offbuf[i - 1] & GOT_PACK_OBJ_DELTA_OFF_MORE);
874 
875 	if (o < sizeof(struct got_packfile_hdr) || o > *outsize)
876 		return got_error(GOT_ERR_PACK_OFFSET);
877 
878 	err = got_pack_hwrite(outfd, offbuf, i, ctx);
879 	if (err)
880 		return err;
881 
882 	*outsize += i;
883 	return NULL;
884 }
885 
886 static const struct got_error *
887 copy_zstream(int infd, int outfd, off_t *outsize, BUF *buf, size_t *buf_pos,
888     struct got_hash *ctx)
889 {
890 	const struct got_error *err = NULL;
891 	z_stream z;
892 	int zret;
893 	char voidbuf[1024];
894 	size_t consumed_total = 0;
895 	off_t zstream_offset = *outsize;
896 
897 	memset(&z, 0, sizeof(z));
898 
899 	z.zalloc = Z_NULL;
900 	z.zfree = Z_NULL;
901 	zret = inflateInit(&z);
902 	if (zret != Z_OK) {
903 		if  (zret == Z_ERRNO)
904 			return got_error_from_errno("inflateInit");
905 		if  (zret == Z_MEM_ERROR) {
906 			errno = ENOMEM;
907 			return got_error_from_errno("inflateInit");
908 		}
909 		return got_error_msg(GOT_ERR_DECOMPRESSION,
910 		    "inflateInit failed");
911 	}
912 
913 	while (zret != Z_STREAM_END) {
914 		size_t last_total_in, consumed;
915 
916 		/*
917 		 * Decompress into the void. Object data will be parsed
918 		 * later, when the pack file is indexed. For now, we just
919 		 * want to locate the end of the compressed stream.
920 		 */
921 		while (zret != Z_STREAM_END && buf_len(buf) - *buf_pos > 0) {
922 			last_total_in = z.total_in;
923 			z.next_in = buf_get(buf) + *buf_pos;
924 			z.avail_in = buf_len(buf) - *buf_pos;
925 			z.next_out = voidbuf;
926 			z.avail_out = sizeof(voidbuf);
927 
928 			zret = inflate(&z, Z_SYNC_FLUSH);
929 			if (zret != Z_OK && zret != Z_BUF_ERROR &&
930 			    zret != Z_STREAM_END) {
931 				err = got_error_fmt(GOT_ERR_DECOMPRESSION,
932 				    "packfile offset %lld",
933 				    (long long)zstream_offset);
934 				goto done;
935 			}
936 			consumed = z.total_in - last_total_in;
937 
938 			err = got_pack_hwrite(outfd, buf_get(buf) + *buf_pos,
939 			    consumed, ctx);
940 			if (err)
941 				goto done;
942 
943 			err = buf_discard(buf, *buf_pos + consumed);
944 			if (err)
945 				goto done;
946 			*buf_pos = 0;
947 
948 			consumed_total += consumed;
949 		}
950 
951 		if (zret != Z_STREAM_END) {
952 			err = read_more_pack_stream(infd, buf, 1);
953 			if (err)
954 				goto done;
955 		}
956 	}
957 
958 	if (err == NULL)
959 		*outsize += consumed_total;
960 done:
961 	inflateEnd(&z);
962 	return err;
963 }
964 
965 static const struct got_error *
966 validate_object_type(int obj_type)
967 {
968 	switch (obj_type) {
969 	case GOT_OBJ_TYPE_BLOB:
970 	case GOT_OBJ_TYPE_COMMIT:
971 	case GOT_OBJ_TYPE_TREE:
972 	case GOT_OBJ_TYPE_TAG:
973 	case GOT_OBJ_TYPE_REF_DELTA:
974 	case GOT_OBJ_TYPE_OFFSET_DELTA:
975 		return NULL;
976 	default:
977 		break;
978 	}
979 
980 	return got_error(GOT_ERR_OBJ_TYPE);
981 }
982 
983 static const struct got_error *
984 ensure_all_objects_exist_locally(struct gotd_ref_updates *ref_updates)
985 {
986 	const struct got_error *err = NULL;
987 	struct gotd_ref_update *ref_update;
988 	struct got_object *obj;
989 
990 	STAILQ_FOREACH(ref_update, ref_updates, entry) {
991 		err = got_object_open(&obj, repo_write.repo,
992 		    &ref_update->new_id);
993 		if (err)
994 			return err;
995 		got_object_close(obj);
996 	}
997 
998 	return NULL;
999 }
1000 
1001 static const struct got_error *
1002 recv_packdata(off_t *outsize, uint32_t *nobj, uint8_t *sha1,
1003     int infd, int outfd)
1004 {
1005 	const struct got_error *err;
1006 	struct repo_write_client *client = &repo_write_client;
1007 	struct got_packfile_hdr hdr;
1008 	size_t have;
1009 	uint32_t nhave = 0;
1010 	struct got_hash ctx;
1011 	uint8_t expected_sha1[SHA1_DIGEST_LENGTH];
1012 	char hex[SHA1_DIGEST_STRING_LENGTH];
1013 	BUF *buf = NULL;
1014 	size_t buf_pos = 0, remain;
1015 	ssize_t w;
1016 
1017 	*outsize = 0;
1018 	*nobj = 0;
1019 
1020 	/* if only deleting references there's nothing to read */
1021 	if (client->nref_updates == client->nref_del)
1022 		return NULL;
1023 
1024 	got_hash_init(&ctx, GOT_HASH_SHA1);
1025 
1026 	err = got_poll_read_full(infd, &have, &hdr, sizeof(hdr), sizeof(hdr));
1027 	if (err)
1028 		return err;
1029 	if (have != sizeof(hdr))
1030 		return got_error_msg(GOT_ERR_BAD_PACKFILE, "short pack file");
1031 	*outsize += have;
1032 
1033 	if (hdr.signature != htobe32(GOT_PACKFILE_SIGNATURE))
1034 		return got_error_msg(GOT_ERR_BAD_PACKFILE,
1035 		    "bad packfile signature");
1036 	if (hdr.version != htobe32(GOT_PACKFILE_VERSION))
1037 		return got_error_msg(GOT_ERR_BAD_PACKFILE,
1038 		    "bad packfile version");
1039 
1040 	*nobj = be32toh(hdr.nobjects);
1041 	if (*nobj == 0) {
1042 		/*
1043 		 * Clients which are creating new references only
1044 		 * will send us an empty pack file.
1045 		 */
1046 		if (client->nref_updates > 0 &&
1047 		    client->nref_updates == client->nref_new)
1048 			return NULL;
1049 
1050 		/*
1051 		 * Clients which only move existing refs will send us an empty
1052 		 * pack file. All referenced objects must exist locally.
1053 		 */
1054 		err = ensure_all_objects_exist_locally(&client->ref_updates);
1055 		if (err) {
1056 			if (err->code != GOT_ERR_NO_OBJ)
1057 				return err;
1058 			return got_error_msg(GOT_ERR_BAD_PACKFILE,
1059 			    "bad packfile with zero objects");
1060 		}
1061 
1062 		client->nref_move = client->nref_updates;
1063 		return NULL;
1064 	}
1065 
1066 	log_debug("expecting %d objects", *nobj);
1067 
1068 	err = got_pack_hwrite(outfd, &hdr, sizeof(hdr), &ctx);
1069 	if (err)
1070 		return err;
1071 
1072 	err = buf_alloc(&buf, 65536);
1073 	if (err)
1074 		return err;
1075 
1076 	while (nhave != *nobj) {
1077 		uint8_t obj_type;
1078 		uint64_t obj_size;
1079 
1080 		err = copy_object_type_and_size(&obj_type, &obj_size,
1081 		    infd, outfd, outsize, buf, &buf_pos, &ctx);
1082 		if (err)
1083 			goto done;
1084 
1085 		err = validate_object_type(obj_type);
1086 		if (err)
1087 			goto done;
1088 
1089 		if (obj_type == GOT_OBJ_TYPE_REF_DELTA) {
1090 			err = copy_ref_delta(infd, outfd, outsize,
1091 			    buf, &buf_pos, &ctx);
1092 			if (err)
1093 				goto done;
1094 		} else if (obj_type == GOT_OBJ_TYPE_OFFSET_DELTA) {
1095 			err = copy_offset_delta(infd, outfd, outsize,
1096 			    buf, &buf_pos, &ctx);
1097 			if (err)
1098 				goto done;
1099 		}
1100 
1101 		err = copy_zstream(infd, outfd, outsize, buf, &buf_pos, &ctx);
1102 		if (err)
1103 			goto done;
1104 
1105 		nhave++;
1106 	}
1107 
1108 	log_debug("received %u objects", *nobj);
1109 
1110 	got_hash_final(&ctx, expected_sha1);
1111 
1112 	remain = buf_len(buf) - buf_pos;
1113 	if (remain < SHA1_DIGEST_LENGTH) {
1114 		err = read_more_pack_stream(infd, buf,
1115 		    SHA1_DIGEST_LENGTH - remain);
1116 		if (err)
1117 			return err;
1118 	}
1119 
1120 	got_sha1_digest_to_str(expected_sha1, hex, sizeof(hex));
1121 	log_debug("expect SHA1: %s", hex);
1122 	got_sha1_digest_to_str(buf_get(buf) + buf_pos, hex, sizeof(hex));
1123 	log_debug("actual SHA1: %s", hex);
1124 
1125 	if (memcmp(buf_get(buf) + buf_pos, expected_sha1,
1126 	    SHA1_DIGEST_LENGTH) != 0) {
1127 		err = got_error(GOT_ERR_PACKFILE_CSUM);
1128 		goto done;
1129 	}
1130 
1131 	memcpy(sha1, expected_sha1, SHA1_DIGEST_LENGTH);
1132 
1133 	w = write(outfd, expected_sha1, SHA1_DIGEST_LENGTH);
1134 	if (w == -1) {
1135 		err = got_error_from_errno("write");
1136 		goto done;
1137 	}
1138 	if (w != SHA1_DIGEST_LENGTH) {
1139 		err = got_error(GOT_ERR_IO);
1140 		goto done;
1141 	}
1142 
1143 	*outsize += SHA1_DIGEST_LENGTH;
1144 
1145 	if (fsync(outfd) == -1) {
1146 		err = got_error_from_errno("fsync");
1147 		goto done;
1148 	}
1149 	if (lseek(outfd, 0L, SEEK_SET) == -1) {
1150 		err = got_error_from_errno("lseek");
1151 		goto done;
1152 	}
1153 done:
1154 	buf_free(buf);
1155 	return err;
1156 }
1157 
1158 static const struct got_error *
1159 report_pack_status(const struct got_error *unpack_err)
1160 {
1161 	const struct got_error *err = NULL;
1162 	struct repo_write_client *client = &repo_write_client;
1163 	struct gotd_imsg_packfile_status istatus;
1164 	struct ibuf *wbuf;
1165 	struct imsgbuf ibuf;
1166 	const char *unpack_ok = "unpack ok\n";
1167 	size_t len;
1168 
1169 	imsg_init(&ibuf, client->fd);
1170 
1171 	if (unpack_err)
1172 		istatus.reason_len = strlen(unpack_err->msg);
1173 	else
1174 		istatus.reason_len = strlen(unpack_ok);
1175 
1176 	len = sizeof(istatus) + istatus.reason_len;
1177 	wbuf = imsg_create(&ibuf, GOTD_IMSG_PACKFILE_STATUS, PROC_REPO_WRITE,
1178 	    repo_write.pid, len);
1179 	if (wbuf == NULL) {
1180 		err = got_error_from_errno("imsg_create PACKFILE_STATUS");
1181 		goto done;
1182 	}
1183 
1184 	if (imsg_add(wbuf, &istatus, sizeof(istatus)) == -1) {
1185 		err = got_error_from_errno("imsg_add PACKFILE_STATUS");
1186 		goto done;
1187 	}
1188 
1189 	if (imsg_add(wbuf, err ? err->msg : unpack_ok,
1190 	    istatus.reason_len) == -1) {
1191 		err = got_error_from_errno("imsg_add PACKFILE_STATUS");
1192 		goto done;
1193 	}
1194 
1195 	imsg_close(&ibuf, wbuf);
1196 
1197 	err = gotd_imsg_flush(&ibuf);
1198 done:
1199 	imsg_clear(&ibuf);
1200 	return err;
1201 }
1202 
1203 static const struct got_error *
1204 recv_packfile(int *have_packfile, struct imsg *imsg)
1205 {
1206 	const struct got_error *err = NULL, *unpack_err;
1207 	struct repo_write_client *client = &repo_write_client;
1208 	struct gotd_imsg_recv_packfile ireq;
1209 	FILE *tempfiles[3] = { NULL, NULL, NULL };
1210 	struct repo_tempfile {
1211 		int fd;
1212 		int idx;
1213 	} repo_tempfiles[3] = { { - 1, - 1 }, { - 1, - 1 }, { - 1, - 1 }, };
1214 	int i;
1215 	size_t datalen;
1216 	struct imsgbuf ibuf;
1217 	struct got_ratelimit rl;
1218 	struct got_pack *pack = NULL;
1219 	off_t pack_filesize = 0;
1220 	uint32_t nobj = 0;
1221 
1222 	log_debug("packfile request received");
1223 
1224 	*have_packfile = 0;
1225 	got_ratelimit_init(&rl, 2, 0);
1226 
1227 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1228 	if (datalen != sizeof(ireq))
1229 		return got_error(GOT_ERR_PRIVSEP_LEN);
1230 	memcpy(&ireq, imsg->data, sizeof(ireq));
1231 
1232 	if (client->pack_pipe == -1 || client->packidx_fd == -1)
1233 		return got_error(GOT_ERR_PRIVSEP_NO_FD);
1234 
1235 	imsg_init(&ibuf, client->fd);
1236 
1237 	pack = &client->pack;
1238 	memset(pack, 0, sizeof(*pack));
1239 	pack->fd = imsg_get_fd(imsg);
1240 	if (pack->fd == -1)
1241 		return got_error(GOT_ERR_PRIVSEP_NO_FD);
1242 
1243 	err = got_delta_cache_alloc(&pack->delta_cache);
1244 	if (err)
1245 		return err;
1246 
1247 	for (i = 0; i < nitems(repo_tempfiles); i++) {
1248 		struct repo_tempfile *t = &repo_tempfiles[i];
1249 		err = got_repo_temp_fds_get(&t->fd, &t->idx, repo_write.repo);
1250 		if (err)
1251 			goto done;
1252 	}
1253 
1254 	for (i = 0; i < nitems(tempfiles); i++) {
1255 		int fd;
1256 		FILE *f;
1257 
1258 		fd = dup(repo_tempfiles[i].fd);
1259 		if (fd == -1) {
1260 			err = got_error_from_errno("dup");
1261 			goto done;
1262 		}
1263 		f = fdopen(fd, "w+");
1264 		if (f == NULL) {
1265 			err = got_error_from_errno("fdopen");
1266 			close(fd);
1267 			goto done;
1268 		}
1269 		tempfiles[i] = f;
1270 	}
1271 
1272 	err = gotd_imsg_flush(&ibuf);
1273 	if (err)
1274 		goto done;
1275 
1276 	log_debug("receiving pack data");
1277 	unpack_err = recv_packdata(&pack_filesize, &nobj,
1278 	    client->pack_sha1, client->pack_pipe, pack->fd);
1279 	if (ireq.report_status) {
1280 		err = report_pack_status(unpack_err);
1281 		if (err) {
1282 			/* Git clients hang up after sending the pack file. */
1283 			if (err->code == GOT_ERR_EOF)
1284 				err = NULL;
1285 		}
1286 	}
1287 	if (unpack_err)
1288 		err = unpack_err;
1289 	if (err)
1290 		goto done;
1291 
1292 	log_debug("pack data received");
1293 
1294 	/*
1295 	 * Clients which are creating new references only will
1296 	 * send us an empty pack file.
1297 	 */
1298 	if (nobj == 0 &&
1299 	    pack_filesize == sizeof(struct got_packfile_hdr) &&
1300 	    client->nref_updates > 0 &&
1301 	    client->nref_updates == client->nref_new)
1302 		goto done;
1303 
1304 	/*
1305 	 * Clients which are deleting references only will send
1306 	 * no pack file.
1307 	 */
1308 	if (nobj == 0 &&
1309 	    client->nref_del > 0 &&
1310 	    client->nref_updates == client->nref_del)
1311 		goto done;
1312 
1313 	/*
1314 	 * Clients which only move existing refs will send us an empty
1315 	 * pack file. All referenced objects must exist locally.
1316 	 */
1317 	if (nobj == 0 &&
1318 	    pack_filesize == sizeof(struct got_packfile_hdr) &&
1319 	    client->nref_move > 0 &&
1320 	    client->nref_updates == client->nref_move)
1321 		goto done;
1322 
1323 	pack->filesize = pack_filesize;
1324 	*have_packfile = 1;
1325 
1326 	log_debug("begin indexing pack (%lld bytes in size)",
1327 	    (long long)pack->filesize);
1328 	err = got_pack_index(pack, client->packidx_fd,
1329 	    tempfiles[0], tempfiles[1], tempfiles[2], client->pack_sha1,
1330 	    pack_index_progress, NULL, &rl);
1331 	if (err)
1332 		goto done;
1333 	log_debug("done indexing pack");
1334 
1335 	if (fsync(client->packidx_fd) == -1) {
1336 		err = got_error_from_errno("fsync");
1337 		goto done;
1338 	}
1339 	if (lseek(client->packidx_fd, 0L, SEEK_SET) == -1)
1340 		err = got_error_from_errno("lseek");
1341 done:
1342 	if (close(client->pack_pipe) == -1 && err == NULL)
1343 		err = got_error_from_errno("close");
1344 	client->pack_pipe = -1;
1345 	for (i = 0; i < nitems(repo_tempfiles); i++) {
1346 		struct repo_tempfile *t = &repo_tempfiles[i];
1347 		if (t->idx != -1)
1348 			got_repo_temp_fds_put(t->idx, repo_write.repo);
1349 	}
1350 	for (i = 0; i < nitems(tempfiles); i++) {
1351 		if (tempfiles[i] && fclose(tempfiles[i]) == EOF && err == NULL)
1352 			err = got_error_from_errno("fclose");
1353 	}
1354 	if (err)
1355 		got_pack_close(pack);
1356 	imsg_clear(&ibuf);
1357 	return err;
1358 }
1359 
1360 static const struct got_error *
1361 verify_packfile(void)
1362 {
1363 	const struct got_error *err = NULL, *close_err;
1364 	struct repo_write_client *client = &repo_write_client;
1365 	struct gotd_ref_update *ref_update;
1366 	struct got_packidx *packidx = NULL;
1367 	struct stat sb;
1368 	char *id_str = NULL;
1369 	struct got_object *obj = NULL;
1370 	struct got_pathlist_entry *pe;
1371 	char hex[SHA1_DIGEST_STRING_LENGTH];
1372 
1373 	if (STAILQ_EMPTY(&client->ref_updates)) {
1374 		return got_error_msg(GOT_ERR_BAD_REQUEST,
1375 		    "cannot verify pack file without any ref-updates");
1376 	}
1377 
1378 	if (client->pack.fd == -1) {
1379 		return got_error_msg(GOT_ERR_BAD_REQUEST,
1380 		    "invalid pack file handle during pack verification");
1381 	}
1382 	if (client->packidx_fd == -1) {
1383 		return got_error_msg(GOT_ERR_BAD_REQUEST,
1384 		    "invalid pack index handle during pack verification");
1385 	}
1386 
1387 	if (fstat(client->packidx_fd, &sb) == -1)
1388 		return got_error_from_errno("pack index fstat");
1389 
1390 	packidx = malloc(sizeof(*packidx));
1391 	memset(packidx, 0, sizeof(*packidx));
1392 	packidx->fd = client->packidx_fd;
1393 	client->packidx_fd = -1;
1394 	packidx->len = sb.st_size;
1395 
1396 	err = got_packidx_init_hdr(packidx, 1, client->pack.filesize);
1397 	if (err)
1398 		return err;
1399 
1400 	STAILQ_FOREACH(ref_update, &client->ref_updates, entry) {
1401 		if (ref_update->delete_ref)
1402 			continue;
1403 
1404 		TAILQ_FOREACH(pe, repo_write.protected_tag_namespaces, entry) {
1405 			err = protect_tag_namespace(pe->path, &client->pack,
1406 			    packidx, ref_update);
1407 			if (err)
1408 				goto done;
1409 		}
1410 
1411 		/*
1412 		 * Objects which already exist in our repository need
1413 		 * not be present in the pack file.
1414 		 */
1415 		err = got_object_open(&obj, repo_write.repo,
1416 		    &ref_update->new_id);
1417 		if (err && err->code != GOT_ERR_NO_OBJ)
1418 			goto done;
1419 		err = NULL;
1420 		if (obj) {
1421 			got_object_close(obj);
1422 			obj = NULL;
1423 		} else {
1424 			int idx = got_packidx_get_object_idx(packidx,
1425 			    &ref_update->new_id);
1426 			if (idx == -1) {
1427 				got_sha1_digest_to_str(ref_update->new_id.sha1,
1428 				    hex, sizeof(hex));
1429 				err = got_error_fmt(GOT_ERR_BAD_PACKFILE,
1430 				    "object %s is missing from pack file",
1431 				    hex);
1432 				goto done;
1433 			}
1434 		}
1435 
1436 		TAILQ_FOREACH(pe, repo_write.protected_branch_namespaces,
1437 		    entry) {
1438 			err = protect_branch_namespace(pe->path,
1439 			    &client->pack, packidx, ref_update);
1440 			if (err)
1441 				goto done;
1442 		}
1443 		TAILQ_FOREACH(pe, repo_write.protected_branches, entry) {
1444 			err = protect_branch(pe->path, &client->pack,
1445 			    packidx, ref_update);
1446 			if (err)
1447 				goto done;
1448 		}
1449 	}
1450 
1451 done:
1452 	close_err = got_packidx_close(packidx);
1453 	if (close_err && err == NULL)
1454 		err = close_err;
1455 	free(id_str);
1456 	if (obj)
1457 		got_object_close(obj);
1458 	return err;
1459 }
1460 
1461 static const struct got_error *
1462 protect_refs_from_deletion(void)
1463 {
1464 	const struct got_error *err = NULL;
1465 	struct repo_write_client *client = &repo_write_client;
1466 	struct gotd_ref_update *ref_update;
1467 	struct got_pathlist_entry *pe;
1468 	const char *refname;
1469 
1470 	STAILQ_FOREACH(ref_update, &client->ref_updates, entry) {
1471 		if (!ref_update->delete_ref)
1472 			continue;
1473 
1474 		refname = got_ref_get_name(ref_update->ref);
1475 
1476 		TAILQ_FOREACH(pe, repo_write.protected_tag_namespaces, entry) {
1477 			err = protect_ref_namespace(refname, pe->path);
1478 			if (err)
1479 				return err;
1480 		}
1481 
1482 		TAILQ_FOREACH(pe, repo_write.protected_branch_namespaces,
1483 		    entry) {
1484 			err = protect_ref_namespace(refname, pe->path);
1485 			if (err)
1486 				return err;
1487 		}
1488 
1489 		TAILQ_FOREACH(pe, repo_write.protected_branches, entry) {
1490 			if (strcmp(refname, pe->path) == 0) {
1491 				return got_error_fmt(GOT_ERR_REF_PROTECTED,
1492 				    "%s", refname);
1493 			}
1494 		}
1495 	}
1496 
1497 	return NULL;
1498 }
1499 
1500 static const struct got_error *
1501 install_packfile(struct gotd_imsgev *iev)
1502 {
1503 	struct repo_write_client *client = &repo_write_client;
1504 	struct gotd_imsg_packfile_install inst;
1505 	int ret;
1506 
1507 	memset(&inst, 0, sizeof(inst));
1508 	memcpy(inst.pack_sha1, client->pack_sha1, SHA1_DIGEST_LENGTH);
1509 
1510 	ret = gotd_imsg_compose_event(iev, GOTD_IMSG_PACKFILE_INSTALL,
1511 	    PROC_REPO_WRITE, -1, &inst, sizeof(inst));
1512 	if (ret == -1)
1513 		return got_error_from_errno("imsg_compose PACKFILE_INSTALL");
1514 
1515 	return NULL;
1516 }
1517 
1518 static const struct got_error *
1519 send_ref_updates_start(int nref_updates, struct gotd_imsgev *iev)
1520 {
1521 	struct gotd_imsg_ref_updates_start istart;
1522 	int ret;
1523 
1524 	memset(&istart, 0, sizeof(istart));
1525 	istart.nref_updates = nref_updates;
1526 
1527 	ret = gotd_imsg_compose_event(iev, GOTD_IMSG_REF_UPDATES_START,
1528 	    PROC_REPO_WRITE, -1, &istart, sizeof(istart));
1529 	if (ret == -1)
1530 		return got_error_from_errno("imsg_compose REF_UPDATES_START");
1531 
1532 	return NULL;
1533 }
1534 
1535 
1536 static const struct got_error *
1537 send_ref_update(struct gotd_ref_update *ref_update, struct gotd_imsgev *iev)
1538 {
1539 	struct gotd_imsg_ref_update iref;
1540 	const char *refname = got_ref_get_name(ref_update->ref);
1541 	struct ibuf *wbuf;
1542 	size_t len;
1543 
1544 	memset(&iref, 0, sizeof(iref));
1545 	memcpy(iref.old_id, ref_update->old_id.sha1, SHA1_DIGEST_LENGTH);
1546 	memcpy(iref.new_id, ref_update->new_id.sha1, SHA1_DIGEST_LENGTH);
1547 	iref.ref_is_new = ref_update->ref_is_new;
1548 	iref.delete_ref = ref_update->delete_ref;
1549 	iref.name_len = strlen(refname);
1550 
1551 	len = sizeof(iref) + iref.name_len;
1552 	wbuf = imsg_create(&iev->ibuf, GOTD_IMSG_REF_UPDATE, PROC_REPO_WRITE,
1553 	    repo_write.pid, len);
1554 	if (wbuf == NULL)
1555 		return got_error_from_errno("imsg_create REF_UPDATE");
1556 
1557 	if (imsg_add(wbuf, &iref, sizeof(iref)) == -1)
1558 		return got_error_from_errno("imsg_add REF_UPDATE");
1559 	if (imsg_add(wbuf, refname, iref.name_len) == -1)
1560 		return got_error_from_errno("imsg_add REF_UPDATE");
1561 
1562 	imsg_close(&iev->ibuf, wbuf);
1563 
1564 	gotd_imsg_event_add(iev);
1565 	return NULL;
1566 }
1567 
1568 static const struct got_error *
1569 update_refs(struct gotd_imsgev *iev)
1570 {
1571 	const struct got_error *err = NULL;
1572 	struct repo_write_client *client = &repo_write_client;
1573 	struct gotd_ref_update *ref_update;
1574 
1575 	err = send_ref_updates_start(client->nref_updates, iev);
1576 	if (err)
1577 		return err;
1578 
1579 	STAILQ_FOREACH(ref_update, &client->ref_updates, entry) {
1580 		err = send_ref_update(ref_update, iev);
1581 		if (err)
1582 			goto done;
1583 	}
1584 done:
1585 	return err;
1586 }
1587 
1588 static const struct got_error *
1589 receive_pack_pipe(struct imsg *imsg, struct gotd_imsgev *iev)
1590 {
1591 	struct repo_write_client *client = &repo_write_client;
1592 	size_t datalen;
1593 
1594 	log_debug("receiving pack pipe descriptor");
1595 
1596 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1597 	if (datalen != 0)
1598 		return got_error(GOT_ERR_PRIVSEP_LEN);
1599 
1600 	if (client->pack_pipe != -1)
1601 		return got_error(GOT_ERR_PRIVSEP_MSG);
1602 
1603 	client->pack_pipe = imsg_get_fd(imsg);
1604 	if (client->pack_pipe == -1)
1605 		return got_error(GOT_ERR_PRIVSEP_NO_FD);
1606 
1607 	return NULL;
1608 }
1609 
1610 static const struct got_error *
1611 receive_pack_idx(struct imsg *imsg, struct gotd_imsgev *iev)
1612 {
1613 	struct repo_write_client *client = &repo_write_client;
1614 	size_t datalen;
1615 
1616 	log_debug("receiving pack index output file");
1617 
1618 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1619 	if (datalen != 0)
1620 		return got_error(GOT_ERR_PRIVSEP_LEN);
1621 
1622 	if (client->packidx_fd != -1)
1623 		return got_error(GOT_ERR_PRIVSEP_MSG);
1624 
1625 	client->packidx_fd = imsg_get_fd(imsg);
1626 	if (client->packidx_fd == -1)
1627 		return got_error(GOT_ERR_PRIVSEP_NO_FD);
1628 
1629 	return NULL;
1630 }
1631 
1632 static char *
1633 get_datestr(time_t *time, char *datebuf)
1634 {
1635 	struct tm mytm, *tm;
1636 	char *p, *s;
1637 
1638 	tm = gmtime_r(time, &mytm);
1639 	if (tm == NULL)
1640 		return NULL;
1641 	s = asctime_r(tm, datebuf);
1642 	if (s == NULL)
1643 		return NULL;
1644 	p = strchr(s, '\n');
1645 	if (p)
1646 		*p = '\0';
1647 	return s;
1648 }
1649 
1650 static const struct got_error *
1651 notify_removed_ref(const char *refname, uint8_t *sha1,
1652     struct gotd_imsgev *iev, int fd)
1653 {
1654 	const struct got_error *err;
1655 	struct got_object_id id;
1656 	char *id_str;
1657 
1658 	memset(&id, 0, sizeof(id));
1659 	memcpy(id.sha1, sha1, sizeof(id.sha1));
1660 
1661 	err = got_object_id_str(&id_str, &id);
1662 	if (err)
1663 		return err;
1664 
1665 	dprintf(fd, "Removed %s: %s\n", refname, id_str);
1666 	free(id_str);
1667 	return err;
1668 }
1669 
1670 static const char *
1671 format_author(char *author)
1672 {
1673 	char *smallerthan;
1674 
1675 	smallerthan = strchr(author, '<');
1676 	if (smallerthan && smallerthan[1] != '\0')
1677 		author = smallerthan + 1;
1678 	author[strcspn(author, "@>")] = '\0';
1679 
1680 	return author;
1681 }
1682 
1683 static const struct got_error *
1684 print_commit_oneline(struct got_commit_object *commit, struct got_object_id *id,
1685     struct got_repository *repo, int fd)
1686 {
1687 	const struct got_error *err = NULL;
1688 	char *id_str = NULL, *logmsg0 = NULL;
1689 	char *s, *nl;
1690 	char *committer = NULL, *author = NULL;
1691 	char datebuf[12]; /* YYYY-MM-DD + SPACE + NUL */
1692 	struct tm tm;
1693 	time_t committer_time;
1694 
1695 	err = got_object_id_str(&id_str, id);
1696 	if (err)
1697 		return err;
1698 
1699 	committer_time = got_object_commit_get_committer_time(commit);
1700 	if (gmtime_r(&committer_time, &tm) == NULL) {
1701 		err = got_error_from_errno("gmtime_r");
1702 		goto done;
1703 	}
1704 	if (strftime(datebuf, sizeof(datebuf), "%G-%m-%d ", &tm) == 0) {
1705 		err = got_error(GOT_ERR_NO_SPACE);
1706 		goto done;
1707 	}
1708 
1709 	err = got_object_commit_get_logmsg(&logmsg0, commit);
1710 	if (err)
1711 		goto done;
1712 
1713 	s = logmsg0;
1714 	while (isspace((unsigned char)s[0]))
1715 		s++;
1716 
1717 	nl = strchr(s, '\n');
1718 	if (nl) {
1719 		*nl = '\0';
1720 	}
1721 
1722 	if (strcmp(got_object_commit_get_author(commit),
1723 	    got_object_commit_get_committer(commit)) != 0) {
1724 		author = strdup(got_object_commit_get_author(commit));
1725 		if (author == NULL) {
1726 			err = got_error_from_errno("strdup");
1727 			goto done;
1728 		}
1729 		dprintf(fd, "%s%.7s %.8s %s\n", datebuf, id_str,
1730 		    format_author(author), s);
1731 	} else {
1732 		committer = strdup(got_object_commit_get_committer(commit));
1733 		if (committer == NULL) {
1734 			err = got_error_from_errno("strdup");
1735 			goto done;
1736 		}
1737 		dprintf(fd, "%s%.7s %.8s %s\n", datebuf, id_str,
1738 		    format_author(committer), s);
1739 	}
1740 
1741 	if (fsync(fd) == -1 && err == NULL)
1742 		err = got_error_from_errno("fsync");
1743 done:
1744 	free(id_str);
1745 	free(logmsg0);
1746 	free(committer);
1747 	free(author);
1748 	return err;
1749 }
1750 
1751 static const struct got_error *
1752 print_diffstat(struct got_diffstat_cb_arg *dsa, int fd)
1753 {
1754 	struct got_pathlist_entry *pe;
1755 
1756 	TAILQ_FOREACH(pe, dsa->paths, entry) {
1757 		struct got_diff_changed_path *cp = pe->data;
1758 		int pad = dsa->max_path_len - pe->path_len + 1;
1759 
1760 		dprintf(fd, " %c  %s%*c | %*d+ %*d-\n", cp->status,
1761 		     pe->path, pad, ' ', dsa->add_cols + 1, cp->add,
1762 		     dsa->rm_cols + 1, cp->rm);
1763 	}
1764 	dprintf(fd,
1765 	    "\n%d file%s changed, %d insertion%s(+), %d deletion%s(-)\n\n",
1766 	    dsa->nfiles, dsa->nfiles > 1 ? "s" : "", dsa->ins,
1767 	    dsa->ins != 1 ? "s" : "", dsa->del, dsa->del != 1 ? "s" : "");
1768 
1769 	return NULL;
1770 }
1771 
1772 static const struct got_error *
1773 print_commit(struct got_commit_object *commit, struct got_object_id *id,
1774     struct got_repository *repo, struct got_pathlist_head *changed_paths,
1775     struct got_diffstat_cb_arg *diffstat, int fd)
1776 {
1777 	const struct got_error *err = NULL;
1778 	char *id_str, *datestr, *logmsg0, *logmsg, *line;
1779 	char datebuf[26];
1780 	time_t committer_time;
1781 	const char *author, *committer;
1782 
1783 	err = got_object_id_str(&id_str, id);
1784 	if (err)
1785 		return err;
1786 
1787 	dprintf(fd, "commit %s\n", id_str);
1788 	free(id_str);
1789 	id_str = NULL;
1790 	dprintf(fd, "from: %s\n", got_object_commit_get_author(commit));
1791 	author = got_object_commit_get_author(commit);
1792 	committer = got_object_commit_get_committer(commit);
1793 	if (strcmp(author, committer) != 0)
1794 		dprintf(fd, "via: %s\n", committer);
1795 	committer_time = got_object_commit_get_committer_time(commit);
1796 	datestr = get_datestr(&committer_time, datebuf);
1797 	if (datestr)
1798 		dprintf(fd, "date: %s UTC\n", datestr);
1799 	if (got_object_commit_get_nparents(commit) > 1) {
1800 		const struct got_object_id_queue *parent_ids;
1801 		struct got_object_qid *qid;
1802 		int n = 1;
1803 		parent_ids = got_object_commit_get_parent_ids(commit);
1804 		STAILQ_FOREACH(qid, parent_ids, entry) {
1805 			err = got_object_id_str(&id_str, &qid->id);
1806 			if (err)
1807 				goto done;
1808 			dprintf(fd, "parent %d: %s\n", n++, id_str);
1809 			free(id_str);
1810 			id_str = NULL;
1811 		}
1812 	}
1813 
1814 	err = got_object_commit_get_logmsg(&logmsg0, commit);
1815 	if (err)
1816 		goto done;
1817 
1818 	dprintf(fd, "messagelen: %zu\n", strlen(logmsg0));
1819 
1820 	logmsg = logmsg0;
1821 	do {
1822 		line = strsep(&logmsg, "\n");
1823 		if (line)
1824 			dprintf(fd, " %s\n", line);
1825 	} while (line);
1826 	free(logmsg0);
1827 
1828 	err = print_diffstat(diffstat, fd);
1829 	if (err)
1830 		goto done;
1831 
1832 	if (fsync(fd) == -1 && err == NULL)
1833 		err = got_error_from_errno("fsync");
1834 done:
1835 	free(id_str);
1836 	return err;
1837 }
1838 
1839 static const struct got_error *
1840 get_changed_paths(struct got_pathlist_head *paths,
1841     struct got_commit_object *commit, struct got_repository *repo,
1842     struct got_diffstat_cb_arg *dsa)
1843 {
1844 	const struct got_error *err = NULL;
1845 	struct got_object_id *tree_id1 = NULL, *tree_id2 = NULL;
1846 	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
1847 	struct got_object_qid *qid;
1848 	got_diff_blob_cb cb = got_diff_tree_collect_changed_paths;
1849 	FILE *f1 = repo_write.diff.f1, *f2 = repo_write.diff.f2;
1850 	int fd1 = repo_write.diff.fd1, fd2 = repo_write.diff.fd2;
1851 
1852 	if (dsa)
1853 		cb = got_diff_tree_compute_diffstat;
1854 
1855 	err = got_opentemp_truncate(f1);
1856 	if (err)
1857 		return err;
1858 	err = got_opentemp_truncate(f2);
1859 	if (err)
1860 		return err;
1861 	err = got_opentemp_truncatefd(fd1);
1862 	if (err)
1863 		return err;
1864 	err = got_opentemp_truncatefd(fd2);
1865 	if (err)
1866 		return err;
1867 
1868 	qid = STAILQ_FIRST(got_object_commit_get_parent_ids(commit));
1869 	if (qid != NULL) {
1870 		struct got_commit_object *pcommit;
1871 		err = got_object_open_as_commit(&pcommit, repo,
1872 		    &qid->id);
1873 		if (err)
1874 			return err;
1875 
1876 		tree_id1 = got_object_id_dup(
1877 		    got_object_commit_get_tree_id(pcommit));
1878 		if (tree_id1 == NULL) {
1879 			got_object_commit_close(pcommit);
1880 			return got_error_from_errno("got_object_id_dup");
1881 		}
1882 		got_object_commit_close(pcommit);
1883 
1884 	}
1885 
1886 	if (tree_id1) {
1887 		err = got_object_open_as_tree(&tree1, repo, tree_id1);
1888 		if (err)
1889 			goto done;
1890 	}
1891 
1892 	tree_id2 = got_object_commit_get_tree_id(commit);
1893 	err = got_object_open_as_tree(&tree2, repo, tree_id2);
1894 	if (err)
1895 		goto done;
1896 
1897 	err = got_diff_tree(tree1, tree2, f1, f2, fd1, fd2, "", "", repo,
1898 	    cb, dsa ? (void *)dsa : paths, dsa ? 1 : 0);
1899 done:
1900 	if (tree1)
1901 		got_object_tree_close(tree1);
1902 	if (tree2)
1903 		got_object_tree_close(tree2);
1904 	free(tree_id1);
1905 	return err;
1906 }
1907 
1908 static const struct got_error *
1909 print_commits(struct got_object_id *root_id, struct got_object_id *end_id,
1910     struct got_repository *repo, int fd)
1911 {
1912 	const struct got_error *err;
1913 	struct got_commit_graph *graph;
1914 	struct got_object_id_queue reversed_commits;
1915 	struct got_object_qid *qid;
1916 	struct got_commit_object *commit = NULL;
1917 	struct got_pathlist_head changed_paths;
1918 	int ncommits = 0;
1919 	const int shortlog_threshold = 50;
1920 
1921 	STAILQ_INIT(&reversed_commits);
1922 	TAILQ_INIT(&changed_paths);
1923 
1924 	/* XXX first-parent only for now */
1925 	err = got_commit_graph_open(&graph, "/", 1);
1926 	if (err)
1927 		return err;
1928 	err = got_commit_graph_bfsort(graph, root_id, repo,
1929 	    check_cancelled, NULL);
1930 	if (err)
1931 		goto done;
1932 	for (;;) {
1933 		struct got_object_id id;
1934 
1935 		err = got_commit_graph_iter_next(&id, graph, repo,
1936 		    check_cancelled, NULL);
1937 		if (err) {
1938 			if (err->code == GOT_ERR_ITER_COMPLETED)
1939 				err = NULL;
1940 			break;
1941 		}
1942 
1943 		err = got_object_open_as_commit(&commit, repo, &id);
1944 		if (err)
1945 			break;
1946 
1947 		if (end_id && got_object_id_cmp(&id, end_id) == 0)
1948 			break;
1949 
1950 		err = got_object_qid_alloc(&qid, &id);
1951 		if (err)
1952 			break;
1953 
1954 		STAILQ_INSERT_HEAD(&reversed_commits, qid, entry);
1955 		ncommits++;
1956 		got_object_commit_close(commit);
1957 
1958 		if (end_id == NULL)
1959 			break;
1960 	}
1961 
1962 	STAILQ_FOREACH(qid, &reversed_commits, entry) {
1963 		struct got_diffstat_cb_arg dsa = { 0, 0, 0, 0, 0, 0,
1964 		    &changed_paths, 0, 0, GOT_DIFF_ALGORITHM_PATIENCE };
1965 
1966 		err = got_object_open_as_commit(&commit, repo, &qid->id);
1967 		if (err)
1968 			break;
1969 
1970 		if (ncommits > shortlog_threshold) {
1971 			err = print_commit_oneline(commit, &qid->id,
1972 			    repo, fd);
1973 			if (err)
1974 				break;
1975 		} else {
1976 			err = get_changed_paths(&changed_paths, commit,
1977 			    repo, &dsa);
1978 			if (err)
1979 				break;
1980 			err = print_commit(commit, &qid->id, repo,
1981 			    &changed_paths, &dsa, fd);
1982 		}
1983 		got_object_commit_close(commit);
1984 		commit = NULL;
1985 		got_pathlist_free(&changed_paths, GOT_PATHLIST_FREE_ALL);
1986 	}
1987 done:
1988 	if (commit)
1989 		got_object_commit_close(commit);
1990 	while (!STAILQ_EMPTY(&reversed_commits)) {
1991 		qid = STAILQ_FIRST(&reversed_commits);
1992 		STAILQ_REMOVE_HEAD(&reversed_commits, entry);
1993 		got_object_qid_free(qid);
1994 	}
1995 	got_pathlist_free(&changed_paths, GOT_PATHLIST_FREE_ALL);
1996 	got_commit_graph_close(graph);
1997 	return err;
1998 }
1999 
2000 static const struct got_error *
2001 print_tag(struct got_object_id *id,
2002     const char *refname, struct got_repository *repo, int fd)
2003 {
2004 	const struct got_error *err = NULL;
2005 	struct got_tag_object *tag = NULL;
2006 	const char *tagger = NULL;
2007 	char *id_str = NULL, *tagmsg0 = NULL, *tagmsg, *line, *datestr;
2008 	char datebuf[26];
2009 	time_t tagger_time;
2010 
2011 	err = got_object_open_as_tag(&tag, repo, id);
2012 	if (err)
2013 		return err;
2014 
2015 	tagger = got_object_tag_get_tagger(tag);
2016 	tagger_time = got_object_tag_get_tagger_time(tag);
2017 	err = got_object_id_str(&id_str,
2018 	    got_object_tag_get_object_id(tag));
2019 	if (err)
2020 		goto done;
2021 
2022 	dprintf(fd, "tag %s\n", refname);
2023 	dprintf(fd, "from: %s\n", tagger);
2024 	datestr = get_datestr(&tagger_time, datebuf);
2025 	if (datestr)
2026 		dprintf(fd, "date: %s UTC\n", datestr);
2027 
2028 	switch (got_object_tag_get_object_type(tag)) {
2029 	case GOT_OBJ_TYPE_BLOB:
2030 		dprintf(fd, "object: %s %s\n", GOT_OBJ_LABEL_BLOB, id_str);
2031 		break;
2032 	case GOT_OBJ_TYPE_TREE:
2033 		dprintf(fd, "object: %s %s\n", GOT_OBJ_LABEL_TREE, id_str);
2034 		break;
2035 	case GOT_OBJ_TYPE_COMMIT:
2036 		dprintf(fd, "object: %s %s\n", GOT_OBJ_LABEL_COMMIT, id_str);
2037 		break;
2038 	case GOT_OBJ_TYPE_TAG:
2039 		dprintf(fd, "object: %s %s\n", GOT_OBJ_LABEL_TAG, id_str);
2040 		break;
2041 	default:
2042 		break;
2043 	}
2044 
2045 	tagmsg0 = strdup(got_object_tag_get_message(tag));
2046 	if (tagmsg0 == NULL) {
2047 		err = got_error_from_errno("strdup");
2048 		goto done;
2049 	}
2050 
2051 	dprintf(fd, "messagelen: %zu\n", strlen(tagmsg0));
2052 
2053 	tagmsg = tagmsg0;
2054 	do {
2055 		line = strsep(&tagmsg, "\n");
2056 		if (line)
2057 			dprintf(fd, " %s\n", line);
2058 	} while (line);
2059 	free(tagmsg0);
2060 done:
2061 	if (tag)
2062 		got_object_tag_close(tag);
2063 	free(id_str);
2064 	return err;
2065 }
2066 
2067 static const struct got_error *
2068 notify_changed_ref(const char *refname, uint8_t *old_sha1,
2069     uint8_t *new_sha1, struct gotd_imsgev *iev, int fd)
2070 {
2071 	const struct got_error *err;
2072 	struct got_object_id old_id, new_id;
2073 	int old_obj_type, new_obj_type;
2074 	const char *label;
2075 	char *new_id_str = NULL;
2076 
2077 	memset(&old_id, 0, sizeof(old_id));
2078 	memcpy(old_id.sha1, old_sha1, sizeof(old_id.sha1));
2079 	memset(&new_id, 0, sizeof(new_id));
2080 	memcpy(new_id.sha1, new_sha1, sizeof(new_id.sha1));
2081 
2082 	err = got_object_get_type(&old_obj_type, repo_write.repo, &old_id);
2083 	if (err)
2084 		return err;
2085 
2086 	err = got_object_get_type(&new_obj_type, repo_write.repo, &new_id);
2087 	if (err)
2088 		return err;
2089 
2090 	switch (new_obj_type) {
2091 	case GOT_OBJ_TYPE_COMMIT:
2092 		err = print_commits(&new_id,
2093 		    old_obj_type == GOT_OBJ_TYPE_COMMIT ? &old_id : NULL,
2094 		    repo_write.repo, fd);
2095 		break;
2096 	case GOT_OBJ_TYPE_TAG:
2097 		err = print_tag(&new_id, refname, repo_write.repo, fd);
2098 		break;
2099 	default:
2100 		err = got_object_type_label(&label, new_obj_type);
2101 		if (err)
2102 			goto done;
2103 		err = got_object_id_str(&new_id_str, &new_id);
2104 		if (err)
2105 			goto done;
2106 		dprintf(fd, "%s: %s object %s\n", refname, label, new_id_str);
2107 		break;
2108 	}
2109 done:
2110 	free(new_id_str);
2111 	return err;
2112 }
2113 
2114 static const struct got_error *
2115 notify_created_ref(const char *refname, uint8_t *sha1,
2116     struct gotd_imsgev *iev, int fd)
2117 {
2118 	const struct got_error *err;
2119 	struct got_object_id id;
2120 	int obj_type;
2121 
2122 	memset(&id, 0, sizeof(id));
2123 	memcpy(id.sha1, sha1, sizeof(id.sha1));
2124 
2125 	err = got_object_get_type(&obj_type, repo_write.repo, &id);
2126 	if (err)
2127 		return err;
2128 
2129 	if (obj_type == GOT_OBJ_TYPE_TAG)
2130 		return print_tag(&id, refname, repo_write.repo, fd);
2131 
2132 	return print_commits(&id, NULL, repo_write.repo, fd);
2133 }
2134 
2135 static const struct got_error *
2136 render_notification(struct imsg *imsg, struct gotd_imsgev *iev)
2137 {
2138 	const struct got_error *err = NULL;
2139 	struct gotd_imsg_notification_content ireq;
2140 	size_t datalen, len;
2141 	char *refname = NULL;
2142 	struct ibuf *wbuf;
2143 	int fd = -1;
2144 
2145 	fd = imsg_get_fd(imsg);
2146 	if (fd == -1)
2147 		return got_error(GOT_ERR_PRIVSEP_NO_FD);
2148 
2149 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
2150 	if (datalen < sizeof(ireq)) {
2151 		err = got_error(GOT_ERR_PRIVSEP_LEN);
2152 		goto done;
2153 	}
2154 
2155 	memcpy(&ireq, imsg->data, sizeof(ireq));
2156 
2157 	if (datalen != sizeof(ireq) +  ireq.refname_len) {
2158 		err = got_error(GOT_ERR_PRIVSEP_LEN);
2159 		goto done;
2160 	}
2161 
2162 	refname = strndup(imsg->data + sizeof(ireq), ireq.refname_len);
2163 	if (refname == NULL) {
2164 		err =  got_error_from_errno("strndup");
2165 		goto done;
2166 	}
2167 
2168 	switch (ireq.action) {
2169 	case GOTD_NOTIF_ACTION_CREATED:
2170 		err = notify_created_ref(refname, ireq.new_id, iev, fd);
2171 		break;
2172 	case GOTD_NOTIF_ACTION_REMOVED:
2173 		err = notify_removed_ref(refname, ireq.old_id, iev, fd);
2174 		break;
2175 	case GOTD_NOTIF_ACTION_CHANGED:
2176 		err = notify_changed_ref(refname, ireq.old_id, ireq.new_id,
2177 		    iev, fd);
2178 		break;
2179 	}
2180 	if (err != NULL)
2181 		goto done;
2182 
2183 	if (fsync(fd) == -1) {
2184 		err = got_error_from_errno("fsync");
2185 		goto done;
2186 	}
2187 
2188 	len = sizeof(ireq) + ireq.refname_len;
2189 	wbuf = imsg_create(&iev->ibuf, GOTD_IMSG_NOTIFY, PROC_REPO_WRITE,
2190 	    repo_write.pid, len);
2191 	if (wbuf == NULL) {
2192 		err = got_error_from_errno("imsg_create REF");
2193 		goto done;
2194 	}
2195 	if (imsg_add(wbuf, &ireq, sizeof(ireq)) == -1) {
2196 		err = got_error_from_errno("imsg_add NOTIFY");
2197 		goto done;
2198 	}
2199 	if (imsg_add(wbuf, refname, ireq.refname_len) == -1) {
2200 		err = got_error_from_errno("imsg_add NOTIFY");
2201 		goto done;
2202 	}
2203 
2204 	imsg_close(&iev->ibuf, wbuf);
2205 	gotd_imsg_event_add(iev);
2206 done:
2207 	free(refname);
2208 	if (fd != -1 && close(fd) == -1 && err == NULL)
2209 		err = got_error_from_errno("close");
2210 	return err;
2211 }
2212 
2213 static void
2214 repo_write_dispatch_session(int fd, short event, void *arg)
2215 {
2216 	const struct got_error *err = NULL;
2217 	struct gotd_imsgev *iev = arg;
2218 	struct imsgbuf *ibuf = &iev->ibuf;
2219 	struct imsg imsg;
2220 	struct repo_write_client *client = &repo_write_client;
2221 	ssize_t n;
2222 	int shut = 0, have_packfile = 0;
2223 
2224 	if (event & EV_READ) {
2225 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
2226 			fatal("imsg_read error");
2227 		if (n == 0)	/* Connection closed. */
2228 			shut = 1;
2229 	}
2230 
2231 	if (event & EV_WRITE) {
2232 		n = msgbuf_write(&ibuf->w);
2233 		if (n == -1 && errno != EAGAIN)
2234 			fatal("msgbuf_write");
2235 		if (n == 0)	/* Connection closed. */
2236 			shut = 1;
2237 	}
2238 
2239 	for (;;) {
2240 		if ((n = imsg_get(ibuf, &imsg)) == -1)
2241 			fatal("%s: imsg_get error", __func__);
2242 		if (n == 0)	/* No more messages. */
2243 			break;
2244 
2245 		if (imsg.hdr.type != GOTD_IMSG_LIST_REFS_INTERNAL &&
2246 		    !repo_write.refs_listed) {
2247 			err = got_error(GOT_ERR_PRIVSEP_MSG);
2248 			break;
2249 		}
2250 
2251 		switch (imsg.hdr.type) {
2252 		case GOTD_IMSG_LIST_REFS_INTERNAL:
2253 			err = list_refs(&imsg);
2254 			if (err)
2255 				log_warnx("ls-refs: %s", err->msg);
2256 			break;
2257 		case GOTD_IMSG_REF_UPDATE:
2258 			err = recv_ref_update(&imsg);
2259 			if (err)
2260 				log_warnx("ref-update: %s", err->msg);
2261 			break;
2262 		case GOTD_IMSG_PACKFILE_PIPE:
2263 			err = receive_pack_pipe(&imsg, iev);
2264 			if (err) {
2265 				log_warnx("receiving pack pipe: %s", err->msg);
2266 				break;
2267 			}
2268 			break;
2269 		case GOTD_IMSG_PACKIDX_FILE:
2270 			err = receive_pack_idx(&imsg, iev);
2271 			if (err) {
2272 				log_warnx("receiving pack index: %s",
2273 				    err->msg);
2274 				break;
2275 			}
2276 			break;
2277 		case GOTD_IMSG_RECV_PACKFILE:
2278 			err = protect_refs_from_deletion();
2279 			if (err)
2280 				break;
2281 			err = recv_packfile(&have_packfile, &imsg);
2282 			if (err) {
2283 				log_warnx("receive packfile: %s", err->msg);
2284 				break;
2285 			}
2286 			if (have_packfile) {
2287 				err = verify_packfile();
2288 				if (err) {
2289 					log_warnx("verify packfile: %s",
2290 					    err->msg);
2291 					break;
2292 				}
2293 				err = install_packfile(iev);
2294 				if (err) {
2295 					log_warnx("install packfile: %s",
2296 					    err->msg);
2297 					break;
2298 				}
2299 				/*
2300 				 * Ensure we re-read the pack index list
2301 				 * upon next access.
2302 				 */
2303 				repo_write.repo->pack_path_mtime.tv_sec = 0;
2304 				repo_write.repo->pack_path_mtime.tv_nsec = 0;
2305 			}
2306 			err = update_refs(iev);
2307 			if (err) {
2308 				log_warnx("update refs: %s", err->msg);
2309 			}
2310 			break;
2311 		case GOTD_IMSG_NOTIFY:
2312 			err = render_notification(&imsg, iev);
2313 			if (err) {
2314 				log_warnx("render notification: %s", err->msg);
2315 				shut = 1;
2316 			}
2317 			break;
2318 		default:
2319 			log_debug("unexpected imsg %d", imsg.hdr.type);
2320 			break;
2321 		}
2322 
2323 		imsg_free(&imsg);
2324 	}
2325 
2326 	if (!shut && check_cancelled(NULL) == NULL) {
2327 		if (err &&
2328 		    gotd_imsg_send_error_event(iev, PROC_REPO_WRITE,
2329 		        client->id, err) == -1) {
2330 			log_warnx("could not send error to parent: %s",
2331 			    err->msg);
2332 		}
2333 		gotd_imsg_event_add(iev);
2334 	} else {
2335 		/* This pipe is dead. Remove its event handler */
2336 		event_del(&iev->ev);
2337 		event_loopexit(NULL);
2338 	}
2339 }
2340 
2341 static const struct got_error *
2342 recv_connect(struct imsg *imsg)
2343 {
2344 	struct gotd_imsgev *iev = &repo_write.session_iev;
2345 	size_t datalen;
2346 
2347 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
2348 	if (datalen != 0)
2349 		return got_error(GOT_ERR_PRIVSEP_LEN);
2350 
2351 	if (repo_write.session_fd != -1)
2352 		return got_error(GOT_ERR_PRIVSEP_MSG);
2353 
2354 	repo_write.session_fd = imsg_get_fd(imsg);
2355 	if (repo_write.session_fd == -1)
2356 		return got_error(GOT_ERR_PRIVSEP_NO_FD);
2357 
2358 	imsg_init(&iev->ibuf, repo_write.session_fd);
2359 	iev->handler = repo_write_dispatch_session;
2360 	iev->events = EV_READ;
2361 	iev->handler_arg = NULL;
2362 	event_set(&iev->ev, iev->ibuf.fd, EV_READ,
2363 	    repo_write_dispatch_session, iev);
2364 	gotd_imsg_event_add(iev);
2365 
2366 	return NULL;
2367 }
2368 
2369 static void
2370 repo_write_dispatch(int fd, short event, void *arg)
2371 {
2372 	const struct got_error *err = NULL;
2373 	struct gotd_imsgev *iev = arg;
2374 	struct imsgbuf *ibuf = &iev->ibuf;
2375 	struct imsg imsg;
2376 	ssize_t n;
2377 	int shut = 0;
2378 	struct repo_write_client *client = &repo_write_client;
2379 
2380 	if (event & EV_READ) {
2381 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
2382 			fatal("imsg_read error");
2383 		if (n == 0)	/* Connection closed. */
2384 			shut = 1;
2385 	}
2386 
2387 	if (event & EV_WRITE) {
2388 		n = msgbuf_write(&ibuf->w);
2389 		if (n == -1 && errno != EAGAIN)
2390 			fatal("msgbuf_write");
2391 		if (n == 0)	/* Connection closed. */
2392 			shut = 1;
2393 	}
2394 
2395 	while (err == NULL && check_cancelled(NULL) == NULL) {
2396 		if ((n = imsg_get(ibuf, &imsg)) == -1)
2397 			fatal("%s: imsg_get", __func__);
2398 		if (n == 0)	/* No more messages. */
2399 			break;
2400 
2401 		switch (imsg.hdr.type) {
2402 		case GOTD_IMSG_CONNECT_REPO_CHILD:
2403 			err = recv_connect(&imsg);
2404 			break;
2405 		default:
2406 			log_debug("unexpected imsg %d", imsg.hdr.type);
2407 			break;
2408 		}
2409 
2410 		imsg_free(&imsg);
2411 	}
2412 
2413 	if (!shut && check_cancelled(NULL) == NULL) {
2414 		if (err &&
2415 		    gotd_imsg_send_error_event(iev, PROC_REPO_WRITE,
2416 		        client->id, err) == -1) {
2417 			log_warnx("could not send error to parent: %s",
2418 			    err->msg);
2419 		}
2420 		gotd_imsg_event_add(iev);
2421 	} else {
2422 		/* This pipe is dead. Remove its event handler */
2423 		event_del(&iev->ev);
2424 		event_loopexit(NULL);
2425 	}
2426 }
2427 
2428 void
2429 repo_write_main(const char *title, const char *repo_path,
2430     int *pack_fds, int *temp_fds,
2431     FILE *diff_f1, FILE *diff_f2, int diff_fd1, int diff_fd2,
2432     struct got_pathlist_head *protected_tag_namespaces,
2433     struct got_pathlist_head *protected_branch_namespaces,
2434     struct got_pathlist_head *protected_branches)
2435 {
2436 	const struct got_error *err = NULL;
2437 	struct repo_write_client *client = &repo_write_client;
2438 	struct gotd_imsgev iev;
2439 
2440 	client->fd = -1;
2441 	client->pack_pipe = -1;
2442 	client->packidx_fd = -1;
2443 	client->pack.fd = -1;
2444 
2445 	repo_write.title = title;
2446 	repo_write.pid = getpid();
2447 	repo_write.pack_fds = pack_fds;
2448 	repo_write.temp_fds = temp_fds;
2449 	repo_write.session_fd = -1;
2450 	repo_write.session_iev.ibuf.fd = -1;
2451 	repo_write.protected_tag_namespaces = protected_tag_namespaces;
2452 	repo_write.protected_branch_namespaces = protected_branch_namespaces;
2453 	repo_write.protected_branches = protected_branches;
2454 	repo_write.diff.f1 = diff_f1;
2455 	repo_write.diff.f2 = diff_f2;
2456 	repo_write.diff.fd1 = diff_fd1;
2457 	repo_write.diff.fd2 = diff_fd2;
2458 
2459 	STAILQ_INIT(&repo_write_client.ref_updates);
2460 
2461 	err = got_repo_open(&repo_write.repo, repo_path, NULL, pack_fds);
2462 	if (err)
2463 		goto done;
2464 	if (!got_repo_is_bare(repo_write.repo)) {
2465 		err = got_error_msg(GOT_ERR_NOT_GIT_REPO,
2466 		    "bare git repository required");
2467 		goto done;
2468 	}
2469 
2470 	got_repo_temp_fds_set(repo_write.repo, temp_fds);
2471 
2472 	signal(SIGINT, catch_sigint);
2473 	signal(SIGTERM, catch_sigterm);
2474 	signal(SIGPIPE, SIG_IGN);
2475 	signal(SIGHUP, SIG_IGN);
2476 
2477 	imsg_init(&iev.ibuf, GOTD_FILENO_MSG_PIPE);
2478 	iev.handler = repo_write_dispatch;
2479 	iev.events = EV_READ;
2480 	iev.handler_arg = NULL;
2481 	event_set(&iev.ev, iev.ibuf.fd, EV_READ, repo_write_dispatch, &iev);
2482 	if (gotd_imsg_compose_event(&iev, GOTD_IMSG_REPO_CHILD_READY,
2483 	    PROC_REPO_WRITE, -1, NULL, 0) == -1) {
2484 		err = got_error_from_errno("imsg compose REPO_CHILD_READY");
2485 		goto done;
2486 	}
2487 
2488 	event_dispatch();
2489 done:
2490 	if (fclose(diff_f1) == EOF && err == NULL)
2491 		err = got_error_from_errno("fclose");
2492 	if (fclose(diff_f2) == EOF && err == NULL)
2493 		err = got_error_from_errno("fclose");
2494 	if (close(diff_fd1) == -1 && err == NULL)
2495 		err = got_error_from_errno("close");
2496 	if (close(diff_fd2) == -1 && err == NULL)
2497 		err = got_error_from_errno("close");
2498 	if (err)
2499 		log_warnx("%s: %s", title, err->msg);
2500 	repo_write_shutdown();
2501 }
2502 
2503 void
2504 repo_write_shutdown(void)
2505 {
2506 	struct repo_write_client *client = &repo_write_client;
2507 	struct gotd_ref_update *ref_update;
2508 
2509 	log_debug("%s: shutting down", repo_write.title);
2510 
2511 	while (!STAILQ_EMPTY(&client->ref_updates)) {
2512 		ref_update = STAILQ_FIRST(&client->ref_updates);
2513 		STAILQ_REMOVE_HEAD(&client->ref_updates, entry);
2514 		got_ref_close(ref_update->ref);
2515 		free(ref_update);
2516 	}
2517 
2518 	got_pack_close(&client->pack);
2519 	if (client->fd != -1)
2520 		close(client->fd);
2521 	if (client->pack_pipe != -1)
2522 		close(client->pack_pipe);
2523 	if (client->packidx_fd != -1)
2524 		close(client->packidx_fd);
2525 
2526 	if (repo_write.repo)
2527 		got_repo_close(repo_write.repo);
2528 	got_repo_pack_fds_close(repo_write.pack_fds);
2529 	got_repo_temp_fds_close(repo_write.temp_fds);
2530 	if (repo_write.session_fd != -1)
2531 		close(repo_write.session_fd);
2532 	exit(0);
2533 }