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Date:: Sat Feb 4 13:58:38 2023 UTC
Message:: rename sha1.c to hash.c
Actions:: History | Blame | Raw File
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/types.h>
19 
20 #include <event.h>
21 #include <errno.h>
22 #include <imsg.h>
23 #include <signal.h>
24 #include <stdlib.h>
25 #include <limits.h>
26 #include <poll.h>
27 #include <sha1.h>
28 #include <sha2.h>
29 #include <siphash.h>
30 #include <stdio.h>
31 #include <string.h>
32 #include <unistd.h>
33 
34 #include "got_error.h"
35 #include "got_cancel.h"
36 #include "got_object.h"
37 #include "got_repository.h"
38 #include "got_reference.h"
39 #include "got_repository_admin.h"
40 
41 #include "got_lib_delta.h"
42 #include "got_lib_object.h"
43 #include "got_lib_object_idset.h"
44 #include "got_lib_hash.h"
45 #include "got_lib_pack.h"
46 #include "got_lib_ratelimit.h"
47 #include "got_lib_pack_create.h"
48 #include "got_lib_poll.h"
49 
50 #include "log.h"
51 #include "gotd.h"
52 #include "repo_read.h"
53 
54 #ifndef nitems
55 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
56 #endif
57 
58 static struct repo_read {
59 	pid_t pid;
60 	const char *title;
61 	struct got_repository *repo;
62 	int *pack_fds;
63 	int *temp_fds;
64 	int session_fd;
65 	struct gotd_imsgev session_iev;
66 } repo_read;
67 
68 static struct repo_read_client {
69 	uint32_t			 id;
70 	int				 fd;
71 	int				 delta_cache_fd;
72 	int				 report_progress;
73 	int				 pack_pipe;
74 	struct gotd_object_id_array	 want_ids;
75 	struct gotd_object_id_array	 have_ids;
76 } repo_read_client;
77 
78 static volatile sig_atomic_t sigint_received;
79 static volatile sig_atomic_t sigterm_received;
80 
81 static void
82 catch_sigint(int signo)
83 {
84 	sigint_received = 1;
85 }
86 
87 static void
88 catch_sigterm(int signo)
89 {
90 	sigterm_received = 1;
91 }
92 
93 static const struct got_error *
94 check_cancelled(void *arg)
95 {
96 	if (sigint_received || sigterm_received)
97 		return got_error(GOT_ERR_CANCELLED);
98 
99 	return NULL;
100 }
101 
102 static const struct got_error *
103 send_symref(struct got_reference *symref, struct got_object_id *target_id,
104     struct imsgbuf *ibuf)
105 {
106 	const struct got_error *err = NULL;
107 	struct gotd_imsg_symref isymref;
108 	const char *refname = got_ref_get_name(symref);
109 	const char *target = got_ref_get_symref_target(symref);
110 	size_t len;
111 	struct ibuf *wbuf;
112 
113 	memset(&isymref, 0, sizeof(isymref));
114 	isymref.name_len = strlen(refname);
115 	isymref.target_len = strlen(target);
116 	memcpy(isymref.target_id, target_id->hash, sizeof(isymref.target_id));
117 
118 	len = sizeof(isymref) + isymref.name_len + isymref.target_len;
119 	if (len > MAX_IMSGSIZE - IMSG_HEADER_SIZE) {
120 		err = got_error(GOT_ERR_NO_SPACE);
121 		goto done;
122 	}
123 
124 	wbuf = imsg_create(ibuf, GOTD_IMSG_SYMREF, 0, 0, len);
125 	if (wbuf == NULL) {
126 		err = got_error_from_errno("imsg_create SYMREF");
127 		goto done;
128 	}
129 
130 	if (imsg_add(wbuf, &isymref, sizeof(isymref)) == -1) {
131 		err = got_error_from_errno("imsg_add SYMREF");
132 		goto done;
133 	}
134 	if (imsg_add(wbuf, refname, isymref.name_len) == -1) {
135 		err = got_error_from_errno("imsg_add SYMREF");
136 		goto done;
137 	}
138 	if (imsg_add(wbuf, target, isymref.target_len) == -1) {
139 		err = got_error_from_errno("imsg_add SYMREF");
140 		goto done;
141 	}
142 
143 	wbuf->fd = -1;
144 	imsg_close(ibuf, wbuf);
145 done:
146 	free(target_id);
147 	return err;
148 }
149 
150 static const struct got_error *
151 send_peeled_tag_ref(struct got_reference *ref, struct got_object *obj,
152     struct imsgbuf *ibuf)
153 {
154 	const struct got_error *err = NULL;
155 	struct got_tag_object *tag;
156 	size_t namelen, len;
157 	char *peeled_refname = NULL;
158 	struct got_object_id *id;
159 	struct ibuf *wbuf;
160 
161 	err = got_object_tag_open(&tag, repo_read.repo, obj);
162 	if (err)
163 		return err;
164 
165 	if (asprintf(&peeled_refname, "%s^{}", got_ref_get_name(ref)) == -1) {
166 		err = got_error_from_errno("asprintf");
167 		goto done;
168 	}
169 
170 	id = got_object_tag_get_object_id(tag);
171 	namelen = strlen(peeled_refname);
172 
173 	len = sizeof(struct gotd_imsg_ref) + namelen;
174 	if (len > MAX_IMSGSIZE - IMSG_HEADER_SIZE) {
175 		err = got_error(GOT_ERR_NO_SPACE);
176 		goto done;
177 	}
178 
179 	wbuf = imsg_create(ibuf, GOTD_IMSG_REF, PROC_REPO_READ,
180 	    repo_read.pid, len);
181 	if (wbuf == NULL) {
182 		err = got_error_from_errno("imsg_create MREF");
183 		goto done;
184 	}
185 
186 	/* Keep in sync with struct gotd_imsg_ref definition. */
187 	if (imsg_add(wbuf, id->hash, SHA1_DIGEST_LENGTH) == -1) {
188 		err = got_error_from_errno("imsg_add REF");
189 		goto done;
190 	}
191 	if (imsg_add(wbuf, &namelen, sizeof(namelen)) == -1) {
192 		err = got_error_from_errno("imsg_add REF");
193 		goto done;
194 	}
195 	if (imsg_add(wbuf, peeled_refname, namelen) == -1) {
196 		err = got_error_from_errno("imsg_add REF");
197 		goto done;
198 	}
199 
200 	wbuf->fd = -1;
201 	imsg_close(ibuf, wbuf);
202 done:
203 	got_object_tag_close(tag);
204 	return err;
205 }
206 
207 static const struct got_error *
208 send_ref(struct got_reference *ref, struct imsgbuf *ibuf)
209 {
210 	const struct got_error *err;
211 	const char *refname = got_ref_get_name(ref);
212 	size_t namelen;
213 	struct got_object_id *id = NULL;
214 	struct got_object *obj = NULL;
215 	size_t len;
216 	struct ibuf *wbuf;
217 
218 	namelen = strlen(refname);
219 
220 	len = sizeof(struct gotd_imsg_ref) + namelen;
221 	if (len > MAX_IMSGSIZE - IMSG_HEADER_SIZE)
222 		return got_error(GOT_ERR_NO_SPACE);
223 
224 	err = got_ref_resolve(&id, repo_read.repo, ref);
225 	if (err)
226 		return err;
227 
228 	wbuf = imsg_create(ibuf, GOTD_IMSG_REF, PROC_REPO_READ,
229 	    repo_read.pid, len);
230 	if (wbuf == NULL) {
231 		err = got_error_from_errno("imsg_create REF");
232 		goto done;
233 	}
234 
235 	/* Keep in sync with struct gotd_imsg_ref definition. */
236 	if (imsg_add(wbuf, id->hash, SHA1_DIGEST_LENGTH) == -1)
237 		return got_error_from_errno("imsg_add REF");
238 	if (imsg_add(wbuf, &namelen, sizeof(namelen)) == -1)
239 		return got_error_from_errno("imsg_add REF");
240 	if (imsg_add(wbuf, refname, namelen) == -1)
241 		return got_error_from_errno("imsg_add REF");
242 
243 	wbuf->fd = -1;
244 	imsg_close(ibuf, wbuf);
245 
246 	err = got_object_open(&obj, repo_read.repo, id);
247 	if (err)
248 		goto done;
249 	if (obj->type == GOT_OBJ_TYPE_TAG)
250 		err = send_peeled_tag_ref(ref, obj, ibuf);
251 done:
252 	if (obj)
253 		got_object_close(obj);
254 	free(id);
255 	return err;
256 }
257 
258 static const struct got_error *
259 list_refs(struct imsg *imsg)
260 {
261 	const struct got_error *err;
262 	struct repo_read_client *client = &repo_read_client;
263 	struct got_reflist_head refs;
264 	struct got_reflist_entry *re;
265 	struct gotd_imsg_list_refs_internal ireq;
266 	size_t datalen;
267 	struct gotd_imsg_reflist irefs;
268 	struct imsgbuf ibuf;
269 	int client_fd = imsg->fd;
270 	struct got_object_id *head_target_id = NULL;
271 
272 	TAILQ_INIT(&refs);
273 
274 	if (client_fd == -1)
275 		return got_error(GOT_ERR_PRIVSEP_NO_FD);
276 
277 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
278 	if (datalen != sizeof(ireq))
279 		return got_error(GOT_ERR_PRIVSEP_LEN);
280 	memcpy(&ireq, imsg->data, sizeof(ireq));
281 
282 	if (ireq.client_id == 0)
283 		return got_error(GOT_ERR_CLIENT_ID);
284 	if (client->id != 0) {
285 		return got_error_msg(GOT_ERR_CLIENT_ID,
286 		    "duplicate list-refs request");
287 	}
288 	client->id = ireq.client_id;
289 	client->fd = client_fd;
290 	client->delta_cache_fd = -1;
291 	client->pack_pipe = -1;
292 
293 	imsg_init(&ibuf, client_fd);
294 
295 	err = got_ref_list(&refs, repo_read.repo, "",
296 	    got_ref_cmp_by_name, NULL);
297 	if (err)
298 		return err;
299 
300 	memset(&irefs, 0, sizeof(irefs));
301 	TAILQ_FOREACH(re, &refs, entry) {
302 		struct got_object_id *id;
303 		int obj_type;
304 
305 		if (got_ref_is_symbolic(re->ref)) {
306 			const char *refname = got_ref_get_name(re->ref);
307 			if (strcmp(refname, GOT_REF_HEAD) != 0)
308 				continue;
309 			err = got_ref_resolve(&head_target_id, repo_read.repo,
310 			    re->ref);
311 			if (err) {
312 				if (err->code != GOT_ERR_NOT_REF)
313 					return err;
314 				/*
315 				 * HEAD points to a non-existent branch.
316 				 * Do not advertise it.
317 				 * Matches git-daemon's behaviour.
318 				 */
319 				head_target_id = NULL;
320 				err = NULL;
321 			} else
322 				irefs.nrefs++;
323 			continue;
324 		}
325 
326 		irefs.nrefs++;
327 
328 		/* Account for a peeled tag refs. */
329 		err = got_ref_resolve(&id, repo_read.repo, re->ref);
330 		if (err)
331 			goto done;
332 		err = got_object_get_type(&obj_type, repo_read.repo, id);
333 		free(id);
334 		if (err)
335 			goto done;
336 		if (obj_type == GOT_OBJ_TYPE_TAG)
337 			irefs.nrefs++;
338 	}
339 
340 	if (imsg_compose(&ibuf, GOTD_IMSG_REFLIST, PROC_REPO_READ,
341 	    repo_read.pid, -1, &irefs, sizeof(irefs)) == -1) {
342 		err = got_error_from_errno("imsg_compose REFLIST");
343 		goto done;
344 	}
345 
346 	/*
347 	 * Send the HEAD symref first. In Git-protocol versions < 2
348 	 * the HEAD symref must be announced on the initial line of
349 	 * the server's ref advertisement.
350 	 * For now, we do not advertise symrefs other than HEAD.
351 	 */
352 	TAILQ_FOREACH(re, &refs, entry) {
353 		if (!got_ref_is_symbolic(re->ref) ||
354 		    strcmp(got_ref_get_name(re->ref), GOT_REF_HEAD) != 0 ||
355 		    head_target_id == NULL)
356 			continue;
357 		err = send_symref(re->ref, head_target_id, &ibuf);
358 		if (err)
359 			goto done;
360 		break;
361 	}
362 	TAILQ_FOREACH(re, &refs, entry) {
363 		if (got_ref_is_symbolic(re->ref))
364 			continue;
365 		err = send_ref(re->ref, &ibuf);
366 		if (err)
367 			goto done;
368 	}
369 
370 	err = gotd_imsg_flush(&ibuf);
371 done:
372 	got_ref_list_free(&refs);
373 	imsg_clear(&ibuf);
374 	return err;
375 }
376 
377 static const struct got_error *
378 record_object_id(struct gotd_object_id_array *array, struct got_object_id *id)
379 {
380 	const size_t alloc_chunksz = 256;
381 
382 	if (array->ids == NULL) {
383 		array->ids = reallocarray(NULL, alloc_chunksz,
384 		    sizeof(*array->ids));
385 		if (array->ids == NULL)
386 			return got_error_from_errno("reallocarray");
387 		array->nalloc = alloc_chunksz;
388 		array->nids = 0;
389 	} else if (array->nalloc <= array->nids) {
390 		struct got_object_id **new;
391 		new = recallocarray(array->ids, array->nalloc,
392 		    array->nalloc + alloc_chunksz, sizeof(*new));
393 		if (new == NULL)
394 			return got_error_from_errno("recallocarray");
395 		array->ids = new;
396 		array->nalloc += alloc_chunksz;
397 	}
398 
399 	array->ids[array->nids] = got_object_id_dup(id);
400 	if (array->ids[array->nids] == NULL)
401 		return got_error_from_errno("got_object_id_dup");
402 	array->nids++;
403 	return NULL;
404 }
405 
406 static void
407 free_object_ids(struct gotd_object_id_array *array)
408 {
409 	size_t i;
410 
411 	for (i = 0; i < array->nids; i++)
412 		free(array->ids[i]);
413 	free(array->ids);
414 
415 	array->ids = NULL;
416 	array->nalloc = 0;
417 	array->nids = 0;
418 }
419 
420 static const struct got_error *
421 recv_want(struct imsg *imsg)
422 {
423 	const struct got_error *err;
424 	struct repo_read_client *client = &repo_read_client;
425 	struct gotd_imsg_want iwant;
426 	size_t datalen;
427 	char hex[SHA1_DIGEST_STRING_LENGTH];
428 	struct got_object_id id;
429 	int obj_type;
430 	struct imsgbuf ibuf;
431 
432 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
433 	if (datalen != sizeof(iwant))
434 		return got_error(GOT_ERR_PRIVSEP_LEN);
435 	memcpy(&iwant, imsg->data, sizeof(iwant));
436 
437 	memset(&id, 0, sizeof(id));
438 	memcpy(id.hash, iwant.object_id, SHA1_DIGEST_LENGTH);
439 
440 	if (log_getverbose() > 0 &&
441 	    got_sha1_digest_to_str(id.hash, hex, sizeof(hex)))
442 		log_debug("client wants %s", hex);
443 
444 	imsg_init(&ibuf, client->fd);
445 
446 	err = got_object_get_type(&obj_type, repo_read.repo, &id);
447 	if (err)
448 		return err;
449 
450 	if (obj_type != GOT_OBJ_TYPE_COMMIT &&
451 	    obj_type != GOT_OBJ_TYPE_TAG)
452 		return got_error(GOT_ERR_OBJ_TYPE);
453 
454 	err = record_object_id(&client->want_ids, &id);
455 	if (err)
456 		return err;
457 
458 	gotd_imsg_send_ack(&id, &ibuf, PROC_REPO_READ, repo_read.pid);
459 	imsg_clear(&ibuf);
460 	return err;
461 }
462 
463 static const struct got_error *
464 recv_have(struct imsg *imsg)
465 {
466 	const struct got_error *err;
467 	struct repo_read_client *client = &repo_read_client;
468 	struct gotd_imsg_have ihave;
469 	size_t datalen;
470 	char hex[SHA1_DIGEST_STRING_LENGTH];
471 	struct got_object_id id;
472 	int obj_type;
473 	struct imsgbuf ibuf;
474 
475 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
476 	if (datalen != sizeof(ihave))
477 		return got_error(GOT_ERR_PRIVSEP_LEN);
478 	memcpy(&ihave, imsg->data, sizeof(ihave));
479 
480 	memset(&id, 0, sizeof(id));
481 	memcpy(id.hash, ihave.object_id, SHA1_DIGEST_LENGTH);
482 
483 	if (log_getverbose() > 0 &&
484 	    got_sha1_digest_to_str(id.hash, hex, sizeof(hex)))
485 		log_debug("client has %s", hex);
486 
487 	imsg_init(&ibuf, client->fd);
488 
489 	err = got_object_get_type(&obj_type, repo_read.repo, &id);
490 	if (err) {
491 		if (err->code == GOT_ERR_NO_OBJ) {
492 			gotd_imsg_send_nak(&id, &ibuf,
493 			    PROC_REPO_READ, repo_read.pid);
494 			err = NULL;
495 		}
496 		goto done;
497 	}
498 
499 	if (obj_type != GOT_OBJ_TYPE_COMMIT &&
500 	    obj_type != GOT_OBJ_TYPE_TAG) {
501 		gotd_imsg_send_nak(&id, &ibuf, PROC_REPO_READ, repo_read.pid);
502 		err = got_error(GOT_ERR_OBJ_TYPE);
503 		goto done;
504 	}
505 
506 	err = record_object_id(&client->have_ids, &id);
507 	if (err)
508 		return err;
509 
510 	gotd_imsg_send_ack(&id, &ibuf, PROC_REPO_READ, repo_read.pid);
511 done:
512 	imsg_clear(&ibuf);
513 	return err;
514 }
515 
516 struct repo_read_pack_progress_arg {
517 	int report_progress;
518 	struct imsgbuf *ibuf;
519 	int sent_ready;
520 };
521 
522 static const struct got_error *
523 pack_progress(void *arg, int ncolored, int nfound, int ntrees,
524     off_t packfile_size, int ncommits, int nobj_total, int nobj_deltify,
525     int nobj_written)
526 {
527 	struct repo_read_pack_progress_arg *a = arg;
528 	struct gotd_imsg_packfile_progress iprog;
529 	int ret;
530 
531 	if (!a->report_progress)
532 		return NULL;
533 	if (packfile_size > 0 && a->sent_ready)
534 		return NULL;
535 
536 	memset(&iprog, 0, sizeof(iprog));
537 	iprog.ncolored = ncolored;
538 	iprog.nfound = nfound;
539 	iprog.ntrees = ntrees;
540 	iprog.packfile_size = packfile_size;
541 	iprog.ncommits = ncommits;
542 	iprog.nobj_total = nobj_total;
543 	iprog.nobj_deltify = nobj_deltify;
544 	iprog.nobj_written = nobj_written;
545 
546 	/* Using synchronous writes since we are blocking the event loop. */
547 	if (packfile_size == 0) {
548 		ret = imsg_compose(a->ibuf, GOTD_IMSG_PACKFILE_PROGRESS,
549 		    PROC_REPO_READ, repo_read.pid, -1, &iprog, sizeof(iprog));
550 		if (ret == -1) {
551 			return got_error_from_errno("imsg compose "
552 			    "PACKFILE_PROGRESS");
553 		}
554 	} else {
555 		a->sent_ready = 1;
556 		ret = imsg_compose(a->ibuf, GOTD_IMSG_PACKFILE_READY,
557 		    PROC_REPO_READ, repo_read.pid, -1, &iprog, sizeof(iprog));
558 		if (ret == -1) {
559 			return got_error_from_errno("imsg compose "
560 			    "PACKFILE_READY");
561 		}
562 	}
563 
564 	return gotd_imsg_flush(a->ibuf);
565 }
566 
567 static const struct got_error *
568 receive_delta_cache_fd(struct imsg *imsg,
569     struct gotd_imsgev *iev)
570 {
571 	struct repo_read_client *client = &repo_read_client;
572 	struct gotd_imsg_send_packfile ireq;
573 	size_t datalen;
574 
575 	log_debug("receving delta cache file");
576 
577 	if (imsg->fd == -1)
578 		return got_error(GOT_ERR_PRIVSEP_NO_FD);
579 
580 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
581 	if (datalen != sizeof(ireq))
582 		return got_error(GOT_ERR_PRIVSEP_LEN);
583 	memcpy(&ireq, imsg->data, sizeof(ireq));
584 
585 	if (client->delta_cache_fd != -1)
586 		return got_error(GOT_ERR_PRIVSEP_MSG);
587 
588 	client->delta_cache_fd = imsg->fd;
589 	client->report_progress = ireq.report_progress;
590 	return NULL;
591 }
592 
593 static const struct got_error *
594 receive_pack_pipe(struct imsg *imsg, struct gotd_imsgev *iev)
595 {
596 	struct repo_read_client *client = &repo_read_client;
597 	struct gotd_imsg_packfile_pipe ireq;
598 	size_t datalen;
599 
600 	log_debug("receving pack pipe descriptor");
601 
602 	if (imsg->fd == -1)
603 		return got_error(GOT_ERR_PRIVSEP_NO_FD);
604 
605 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
606 	if (datalen != sizeof(ireq))
607 		return got_error(GOT_ERR_PRIVSEP_LEN);
608 	memcpy(&ireq, imsg->data, sizeof(ireq));
609 
610 	if (client->pack_pipe != -1)
611 		return got_error(GOT_ERR_PRIVSEP_MSG);
612 
613 	client->pack_pipe = imsg->fd;
614 	return NULL;
615 }
616 
617 static const struct got_error *
618 send_packfile(struct imsg *imsg, struct gotd_imsgev *iev)
619 {
620 	const struct got_error *err = NULL;
621 	struct repo_read_client *client = &repo_read_client;
622 	struct gotd_imsg_packfile_done idone;
623 	uint8_t packhash[SHA1_DIGEST_LENGTH];
624 	char hex[SHA1_DIGEST_STRING_LENGTH];
625 	FILE *delta_cache = NULL;
626 	struct imsgbuf ibuf;
627 	struct repo_read_pack_progress_arg pa;
628 	struct got_ratelimit rl;
629 
630 	log_debug("packfile request received");
631 
632 	got_ratelimit_init(&rl, 2, 0);
633 
634 	if (client->delta_cache_fd == -1 || client->pack_pipe == -1)
635 		return got_error(GOT_ERR_PRIVSEP_NO_FD);
636 
637 	imsg_init(&ibuf, client->fd);
638 
639 	delta_cache = fdopen(client->delta_cache_fd, "w+");
640 	if (delta_cache == NULL) {
641 		err = got_error_from_errno("fdopen");
642 		goto done;
643 	}
644 	client->delta_cache_fd = -1;
645 
646 	memset(&pa, 0, sizeof(pa));
647 	pa.ibuf = &ibuf;
648 	pa.report_progress = client->report_progress;
649 
650 	err = got_pack_create(packhash, client->pack_pipe, delta_cache,
651 	    client->have_ids.ids, client->have_ids.nids,
652 	    client->want_ids.ids, client->want_ids.nids,
653 	    repo_read.repo, 0, 1, pack_progress, &pa, &rl,
654 	    check_cancelled, NULL);
655 	if (err)
656 		goto done;
657 
658 	if (log_getverbose() > 0 &&
659 	    got_sha1_digest_to_str(packhash, hex, sizeof(hex)))
660 		log_debug("sent pack-%s.pack", hex);
661 
662 	memset(&idone, 0, sizeof(idone));
663 	idone.client_id = client->id;
664 	if (gotd_imsg_compose_event(iev, GOTD_IMSG_PACKFILE_DONE,
665 	    PROC_REPO_READ, -1, &idone, sizeof(idone)) == -1)
666 		err = got_error_from_errno("imsg compose PACKFILE_DONE");
667 done:
668 	if (delta_cache != NULL && fclose(delta_cache) == EOF && err == NULL)
669 		err = got_error_from_errno("fclose");
670 	imsg_clear(&ibuf);
671 	return err;
672 }
673 
674 static const struct got_error *
675 recv_disconnect(struct imsg *imsg)
676 {
677 	const struct got_error *err = NULL;
678 	struct gotd_imsg_disconnect idisconnect;
679 	size_t datalen;
680 	int delta_cache_fd, pack_pipe;
681 	struct repo_read_client *client = &repo_read_client;
682 
683 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
684 	if (datalen != sizeof(idisconnect))
685 		return got_error(GOT_ERR_PRIVSEP_LEN);
686 	memcpy(&idisconnect, imsg->data, sizeof(idisconnect));
687 
688 	log_debug("client disconnecting");
689 
690 	free_object_ids(&client->have_ids);
691 	free_object_ids(&client->want_ids);
692 	if (close(client->fd) == -1)
693 		err = got_error_from_errno("close");
694 	delta_cache_fd = client->delta_cache_fd;
695 	if (delta_cache_fd != -1 && close(delta_cache_fd) == -1 && err == NULL)
696 		return got_error_from_errno("close");
697 	pack_pipe = client->pack_pipe;
698 	if (pack_pipe != -1 && close(pack_pipe) == -1 && err == NULL)
699 		return got_error_from_errno("close");
700 	return err;
701 }
702 
703 static void
704 repo_read_dispatch_session(int fd, short event, void *arg)
705 {
706 	const struct got_error *err = NULL;
707 	struct gotd_imsgev *iev = arg;
708 	struct imsgbuf *ibuf = &iev->ibuf;
709 	struct imsg imsg;
710 	ssize_t n;
711 	int shut = 0;
712 	struct repo_read_client *client = &repo_read_client;
713 
714 	if (event & EV_READ) {
715 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
716 			fatal("imsg_read error");
717 		if (n == 0)	/* Connection closed. */
718 			shut = 1;
719 	}
720 
721 	if (event & EV_WRITE) {
722 		n = msgbuf_write(&ibuf->w);
723 		if (n == -1 && errno != EAGAIN)
724 			fatal("msgbuf_write");
725 		if (n == 0)	/* Connection closed. */
726 			shut = 1;
727 	}
728 
729 	while (err == NULL && check_cancelled(NULL) == NULL) {
730 		if ((n = imsg_get(ibuf, &imsg)) == -1)
731 			fatal("%s: imsg_get", __func__);
732 		if (n == 0)	/* No more messages. */
733 			break;
734 
735 		if (imsg.hdr.type != GOTD_IMSG_LIST_REFS_INTERNAL &&
736 		    client->id == 0) {
737 			err = got_error(GOT_ERR_PRIVSEP_MSG);
738 			break;
739 		}
740 
741 		switch (imsg.hdr.type) {
742 		case GOTD_IMSG_LIST_REFS_INTERNAL:
743 			err = list_refs(&imsg);
744 			if (err)
745 				log_warnx("%s: ls-refs: %s", repo_read.title,
746 				    err->msg);
747 			break;
748 		case GOTD_IMSG_WANT:
749 			err = recv_want(&imsg);
750 			if (err)
751 				log_warnx("%s: want-line: %s", repo_read.title,
752 				    err->msg);
753 			break;
754 		case GOTD_IMSG_HAVE:
755 			err = recv_have(&imsg);
756 			if (err)
757 				log_warnx("%s: have-line: %s", repo_read.title,
758 				    err->msg);
759 			break;
760 		case GOTD_IMSG_SEND_PACKFILE:
761 			err = receive_delta_cache_fd(&imsg, iev);
762 			if (err)
763 				log_warnx("%s: receiving delta cache: %s",
764 				    repo_read.title, err->msg);
765 			break;
766 		case GOTD_IMSG_PACKFILE_PIPE:
767 			err = receive_pack_pipe(&imsg, iev);
768 			if (err) {
769 				log_warnx("%s: receiving pack pipe: %s",
770 				    repo_read.title, err->msg);
771 				break;
772 			}
773 			err = send_packfile(&imsg, iev);
774 			if (err)
775 				log_warnx("%s: sending packfile: %s",
776 				    repo_read.title, err->msg);
777 			break;
778 		case GOTD_IMSG_DISCONNECT:
779 			err = recv_disconnect(&imsg);
780 			if (err)
781 				log_warnx("%s: disconnect: %s",
782 				    repo_read.title, err->msg);
783 			shut = 1;
784 			break;
785 		default:
786 			log_debug("%s: unexpected imsg %d", repo_read.title,
787 			    imsg.hdr.type);
788 			break;
789 		}
790 
791 		imsg_free(&imsg);
792 	}
793 
794 	if (!shut && check_cancelled(NULL) == NULL) {
795 		if (err &&
796 		    gotd_imsg_send_error_event(iev, PROC_REPO_READ,
797 		        client->id, err) == -1) {
798 			log_warnx("could not send error to parent: %s",
799 			    err->msg);
800 		}
801 		gotd_imsg_event_add(iev);
802 	} else {
803 		/* This pipe is dead. Remove its event handler */
804 		event_del(&iev->ev);
805 		event_loopexit(NULL);
806 	}
807 }
808 
809 static const struct got_error *
810 recv_connect(struct imsg *imsg)
811 {
812 	struct gotd_imsgev *iev = &repo_read.session_iev;
813 	size_t datalen;
814 
815 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
816 	if (datalen != 0)
817 		return got_error(GOT_ERR_PRIVSEP_LEN);
818 	if (imsg->fd == -1)
819 		return got_error(GOT_ERR_PRIVSEP_NO_FD);
820 
821 	if (repo_read.session_fd != -1)
822 		return got_error(GOT_ERR_PRIVSEP_MSG);
823 
824 	repo_read.session_fd = imsg->fd;
825 
826 	imsg_init(&iev->ibuf, repo_read.session_fd);
827 	iev->handler = repo_read_dispatch_session;
828 	iev->events = EV_READ;
829 	iev->handler_arg = NULL;
830 	event_set(&iev->ev, iev->ibuf.fd, EV_READ,
831 	    repo_read_dispatch_session, iev);
832 	gotd_imsg_event_add(iev);
833 
834 	return NULL;
835 }
836 
837 static void
838 repo_read_dispatch(int fd, short event, void *arg)
839 {
840 	const struct got_error *err = NULL;
841 	struct gotd_imsgev *iev = arg;
842 	struct imsgbuf *ibuf = &iev->ibuf;
843 	struct imsg imsg;
844 	ssize_t n;
845 	int shut = 0;
846 	struct repo_read_client *client = &repo_read_client;
847 
848 	if (event & EV_READ) {
849 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
850 			fatal("imsg_read error");
851 		if (n == 0)	/* Connection closed. */
852 			shut = 1;
853 	}
854 
855 	if (event & EV_WRITE) {
856 		n = msgbuf_write(&ibuf->w);
857 		if (n == -1 && errno != EAGAIN)
858 			fatal("msgbuf_write");
859 		if (n == 0)	/* Connection closed. */
860 			shut = 1;
861 	}
862 
863 	while (err == NULL && check_cancelled(NULL) == NULL) {
864 		if ((n = imsg_get(ibuf, &imsg)) == -1)
865 			fatal("%s: imsg_get", __func__);
866 		if (n == 0)	/* No more messages. */
867 			break;
868 
869 		switch (imsg.hdr.type) {
870 		case GOTD_IMSG_CONNECT_REPO_CHILD:
871 			err = recv_connect(&imsg);
872 			break;
873 		default:
874 			log_debug("%s: unexpected imsg %d", repo_read.title,
875 			    imsg.hdr.type);
876 			break;
877 		}
878 
879 		imsg_free(&imsg);
880 	}
881 
882 	if (!shut && check_cancelled(NULL) == NULL) {
883 		if (err &&
884 		    gotd_imsg_send_error_event(iev, PROC_REPO_READ,
885 		        client->id, err) == -1) {
886 			log_warnx("could not send error to parent: %s",
887 			    err->msg);
888 		}
889 		gotd_imsg_event_add(iev);
890 	} else {
891 		/* This pipe is dead. Remove its event handler */
892 		event_del(&iev->ev);
893 		event_loopexit(NULL);
894 	}
895 }
896 
897 void
898 repo_read_main(const char *title, const char *repo_path,
899     int *pack_fds, int *temp_fds)
900 {
901 	const struct got_error *err = NULL;
902 	struct gotd_imsgev iev;
903 
904 	repo_read.title = title;
905 	repo_read.pid = getpid();
906 	repo_read.pack_fds = pack_fds;
907 	repo_read.temp_fds = temp_fds;
908 	repo_read.session_fd = -1;
909 	repo_read.session_iev.ibuf.fd = -1;
910 
911 	err = got_repo_open(&repo_read.repo, repo_path, NULL, pack_fds);
912 	if (err)
913 		goto done;
914 	if (!got_repo_is_bare(repo_read.repo)) {
915 		err = got_error_msg(GOT_ERR_NOT_GIT_REPO,
916 		    "bare git repository required");
917 		goto done;
918 	}
919 
920 	got_repo_temp_fds_set(repo_read.repo, temp_fds);
921 
922 	signal(SIGINT, catch_sigint);
923 	signal(SIGTERM, catch_sigterm);
924 	signal(SIGPIPE, SIG_IGN);
925 	signal(SIGHUP, SIG_IGN);
926 
927 	imsg_init(&iev.ibuf, GOTD_FILENO_MSG_PIPE);
928 	iev.handler = repo_read_dispatch;
929 	iev.events = EV_READ;
930 	iev.handler_arg = NULL;
931 	event_set(&iev.ev, iev.ibuf.fd, EV_READ, repo_read_dispatch, &iev);
932 
933 	if (gotd_imsg_compose_event(&iev, GOTD_IMSG_REPO_CHILD_READY,
934 	    PROC_REPO_READ, -1, NULL, 0) == -1) {
935 		err = got_error_from_errno("imsg compose REPO_CHILD_READY");
936 		goto done;
937 	}
938 
939 	event_dispatch();
940 done:
941 	if (err)
942 		log_warnx("%s: %s", title, err->msg);
943 	repo_read_shutdown();
944 }
945 
946 void
947 repo_read_shutdown(void)
948 {
949 	log_debug("%s: shutting down", repo_read.title);
950 	if (repo_read.repo)
951 		got_repo_close(repo_read.repo);
952 	got_repo_pack_fds_close(repo_read.pack_fds);
953 	got_repo_temp_fds_close(repo_read.temp_fds);
954 	if (repo_read.session_fd != -1)
955 		close(repo_read.session_fd);
956 	exit(0);
957 }