Gotweb

Blob

Date:: Fri Oct 28 20:51:06 2022 UTC
Message:: remove sendfd pledge promise from gotd repo_read process Have the parent process send one end of the pipe directly to gotsh(1), such that repo_write can run without "sendfd". Combining "sendfd" and "recvfd" in the same process is frowned upon. ok tracey
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/tree.h>
19 #include <sys/time.h>
20 #include <sys/types.h>
21 #include <sys/stat.h>
22 #include <sys/socket.h>
23 #include <sys/un.h>
24 #include <sys/wait.h>
25 
26 #include <fcntl.h>
27 #include <err.h>
28 #include <errno.h>
29 #include <event.h>
30 #include <limits.h>
31 #include <pwd.h>
32 #include <grp.h>
33 #include <imsg.h>
34 #include <sha1.h>
35 #include <signal.h>
36 #include <siphash.h>
37 #include <stdarg.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <syslog.h>
43 #include <unistd.h>
44 
45 #include "got_error.h"
46 #include "got_opentemp.h"
47 #include "got_path.h"
48 #include "got_repository.h"
49 #include "got_object.h"
50 #include "got_reference.h"
51 
52 #include "got_lib_delta.h"
53 #include "got_lib_object.h"
54 #include "got_lib_object_cache.h"
55 #include "got_lib_sha1.h"
56 #include "got_lib_gitproto.h"
57 #include "got_lib_pack.h"
58 #include "got_lib_repository.h"
59 
60 #include "gotd.h"
61 #include "log.h"
62 #include "repo_read.h"
63 #include "repo_write.h"
64 
65 #ifndef nitems
66 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
67 #endif
68 
69 struct gotd_client {
70 	STAILQ_ENTRY(gotd_client)	 entry;
71 	enum gotd_client_state		 state;
72 	struct gotd_client_capability	*capabilities;
73 	size_t				 ncapa_alloc;
74 	size_t				 ncapabilities;
75 	uint32_t			 id;
76 	int				 fd;
77 	int				 delta_cache_fd;
78 	struct gotd_imsgev		 iev;
79 	struct event			 tmo;
80 	uid_t				 euid;
81 	gid_t				 egid;
82 	struct gotd_child_proc		*repo_read;
83 	struct gotd_child_proc		*repo_write;
84 	char				*packfile_path;
85 	char				*packidx_path;
86 	int				 nref_updates;
87 };
88 STAILQ_HEAD(gotd_clients, gotd_client);
89 
90 static struct gotd_clients gotd_clients[GOTD_CLIENT_TABLE_SIZE];
91 static SIPHASH_KEY clients_hash_key;
92 volatile int client_cnt;
93 static struct timeval timeout = { 3600, 0 };
94 static int inflight;
95 static struct gotd gotd;
96 
97 void gotd_sighdlr(int sig, short event, void *arg);
98 
99 __dead static void
100 usage()
101 {
102 	fprintf(stderr, "usage: %s [-dv] [-f config-file]\n", getprogname());
103 	exit(1);
104 }
105 
106 static int
107 unix_socket_listen(const char *unix_socket_path, uid_t uid, gid_t gid)
108 {
109 	struct sockaddr_un sun;
110 	int fd = -1;
111 	mode_t old_umask, mode;
112 
113 	fd = socket(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK| SOCK_CLOEXEC, 0);
114 	if (fd == -1) {
115 		log_warn("socket");
116 		return -1;
117 	}
118 
119 	sun.sun_family = AF_UNIX;
120 	if (strlcpy(sun.sun_path, unix_socket_path,
121 	    sizeof(sun.sun_path)) >= sizeof(sun.sun_path)) {
122 		log_warnx("%s: name too long", unix_socket_path);
123 		close(fd);
124 		return -1;
125 	}
126 
127 	if (unlink(unix_socket_path) == -1) {
128 		if (errno != ENOENT) {
129 			log_warn("unlink %s", unix_socket_path);
130 			close(fd);
131 			return -1;
132 		}
133 	}
134 
135 	old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);
136 	mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP;
137 
138 	if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
139 		log_warn("bind: %s", unix_socket_path);
140 		close(fd);
141 		umask(old_umask);
142 		return -1;
143 	}
144 
145 	umask(old_umask);
146 
147 	if (chmod(unix_socket_path, mode) == -1) {
148 		log_warn("chmod %o %s", mode, unix_socket_path);
149 		close(fd);
150 		unlink(unix_socket_path);
151 		return -1;
152 	}
153 
154 	if (chown(unix_socket_path, uid, gid) == -1) {
155 		log_warn("chown %s uid=%d gid=%d", unix_socket_path, uid, gid);
156 		close(fd);
157 		unlink(unix_socket_path);
158 		return -1;
159 	}
160 
161 	if (listen(fd, GOTD_UNIX_SOCKET_BACKLOG) == -1) {
162 		log_warn("listen");
163 		close(fd);
164 		unlink(unix_socket_path);
165 		return -1;
166 	}
167 
168 	return fd;
169 }
170 
171 static struct group *
172 match_group(gid_t *groups, int ngroups, const char *unix_group_name)
173 {
174 	struct group *gr;
175 	int i;
176 
177 	for (i = 0; i < ngroups; i++) {
178 		gr = getgrgid(groups[i]);
179 		if (gr == NULL) {
180 			log_warn("getgrgid %d", groups[i]);
181 			continue;
182 		}
183 		if (strcmp(gr->gr_name, unix_group_name) == 0)
184 			return gr;
185 	}
186 
187 	return NULL;
188 }
189 
190 static int
191 accept_reserve(int fd, struct sockaddr *addr, socklen_t *addrlen,
192     int reserve, volatile int *counter)
193 {
194 	int ret;
195 
196 	if (getdtablecount() + reserve +
197 	    ((*counter + 1) * GOTD_FD_NEEDED) >= getdtablesize()) {
198 		log_debug("inflight fds exceeded");
199 		errno = EMFILE;
200 		return -1;
201 	}
202 
203 	if ((ret = accept4(fd, addr, addrlen,
204 	    SOCK_NONBLOCK | SOCK_CLOEXEC)) > -1) {
205 		(*counter)++;
206 	}
207 
208 	return ret;
209 }
210 
211 static uint64_t
212 client_hash(uint32_t client_id)
213 {
214 	return SipHash24(&clients_hash_key, &client_id, sizeof(client_id));
215 }
216 
217 static void
218 add_client(struct gotd_client *client)
219 {
220 	uint64_t slot = client_hash(client->id) % nitems(gotd_clients);
221 	STAILQ_INSERT_HEAD(&gotd_clients[slot], client, entry);
222 	client_cnt++;
223 }
224 
225 static struct gotd_client *
226 find_client(uint32_t client_id)
227 {
228 	uint64_t slot;
229 	struct gotd_client *c;
230 
231 	slot = client_hash(client_id) % nitems(gotd_clients);
232 	STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
233 		if (c->id == client_id)
234 			return c;
235 	}
236 
237 	return NULL;
238 }
239 
240 static uint32_t
241 get_client_id(void)
242 {
243 	int duplicate = 0;
244 	uint32_t id;
245 
246 	do {
247 		id = arc4random();
248 		duplicate = (find_client(id) != NULL);
249 	} while (duplicate || id == 0);
250 
251 	return id;
252 }
253 
254 static struct gotd_child_proc *
255 get_client_proc(struct gotd_client *client)
256 {
257 	if (client->repo_read && client->repo_write) {
258 		fatalx("uid %d is reading and writing in the same session",
259 		    client->euid);
260 		/* NOTREACHED */
261 	}
262 
263 	if (client->repo_read)
264 		return client->repo_read;
265 	else if (client->repo_write)
266 		return client->repo_write;
267 	else {
268 		fatal("uid %d is neither reading nor writing", client->euid);
269 		/* NOTREACHED */
270 	}
271 	return NULL;
272 }
273 
274 static int
275 client_is_reading(struct gotd_client *client)
276 {
277 	return client->repo_read != NULL;
278 }
279 
280 static int
281 client_is_writing(struct gotd_client *client)
282 {
283 	return client->repo_write != NULL;
284 }
285 
286 static const struct got_error *
287 ensure_client_is_reading(struct gotd_client *client)
288 {
289 	if (!client_is_reading(client)) {
290 		return got_error_fmt(GOT_ERR_BAD_PACKET,
291 		    "uid %d made a read-request but is not reading from "
292 		    "a repository", client->euid);
293 	}
294 
295 	return NULL;
296 }
297 
298 static const struct got_error *
299 ensure_client_is_writing(struct gotd_client *client)
300 {
301 	if (!client_is_writing(client)) {
302 		return got_error_fmt(GOT_ERR_BAD_PACKET,
303 		    "uid %d made a write-request but is not writing to "
304 		    "a repository", client->euid);
305 	}
306 
307 	return NULL;
308 }
309 
310 static const struct got_error *
311 ensure_client_is_not_writing(struct gotd_client *client)
312 {
313 	if (client_is_writing(client)) {
314 		return got_error_fmt(GOT_ERR_BAD_PACKET,
315 		    "uid %d made a read-request but is writing to "
316 		    "a repository", client->euid);
317 	}
318 
319 	return NULL;
320 }
321 
322 static const struct got_error *
323 ensure_client_is_not_reading(struct gotd_client *client)
324 {
325 	if (client_is_reading(client)) {
326 		return got_error_fmt(GOT_ERR_BAD_PACKET,
327 		    "uid %d made a write-request but is reading from "
328 		    "a repository", client->euid);
329 	}
330 
331 	return NULL;
332 }
333 
334 static void
335 disconnect(struct gotd_client *client)
336 {
337 	struct gotd_imsg_disconnect idisconnect;
338 	struct gotd_child_proc *proc = get_client_proc(client);
339 	uint64_t slot;
340 
341 	log_debug("uid %d: disconnecting", client->euid);
342 
343 	idisconnect.client_id = client->id;
344 	if (gotd_imsg_compose_event(&proc->iev,
345 	    GOTD_IMSG_DISCONNECT, PROC_GOTD, -1,
346 	    &idisconnect, sizeof(idisconnect)) == -1)
347 		log_warn("imsg compose DISCONNECT");
348 
349 	slot = client_hash(client->id) % nitems(gotd_clients);
350 	STAILQ_REMOVE(&gotd_clients[slot], client, gotd_client, entry);
351 	imsg_clear(&client->iev.ibuf);
352 	event_del(&client->iev.ev);
353 	evtimer_del(&client->tmo);
354 	close(client->fd);
355 	if (client->delta_cache_fd != -1)
356 		close(client->delta_cache_fd);
357 	if (client->packfile_path) {
358 		if (unlink(client->packfile_path) == -1 && errno != ENOENT)
359 			log_warn("unlink %s: ", client->packfile_path);
360 		free(client->packfile_path);
361 	}
362 	if (client->packidx_path) {
363 		if (unlink(client->packidx_path) == -1 && errno != ENOENT)
364 			log_warn("unlink %s: ", client->packidx_path);
365 		free(client->packidx_path);
366 	}
367 	free(client->capabilities);
368 	free(client);
369 	inflight--;
370 	client_cnt--;
371 }
372 
373 static void
374 disconnect_on_error(struct gotd_client *client, const struct got_error *err)
375 {
376 	struct imsgbuf ibuf;
377 
378 	log_warnx("uid %d: %s", client->euid, err->msg);
379 	if (err->code != GOT_ERR_EOF) {
380 		imsg_init(&ibuf, client->fd);
381 		gotd_imsg_send_error(&ibuf, 0, PROC_GOTD, err);
382 		imsg_clear(&ibuf);
383 	}
384 	disconnect(client);
385 }
386 
387 static struct gotd_child_proc *
388 find_proc_by_repo_name(enum gotd_procid proc_id, const char *repo_name)
389 {
390 	struct gotd_child_proc *proc;
391 	int i;
392 	size_t namelen;
393 
394 	for (i = 0; i < gotd.nprocs; i++) {
395 		proc = &gotd.procs[i];
396 		if (proc->type != proc_id)
397 			continue;
398 		namelen = strlen(proc->repo_name);
399 		if (strncmp(proc->repo_name, repo_name, namelen) != 0)
400 			continue;
401 		if (repo_name[namelen] == '\0' ||
402 		    strcmp(&repo_name[namelen], ".git") == 0)
403 			return proc;
404 	}
405 
406 	return NULL;
407 }
408 
409 static struct gotd_child_proc *
410 find_proc_by_fd(int fd)
411 {
412 	struct gotd_child_proc *proc;
413 	int i;
414 
415 	for (i = 0; i < gotd.nprocs; i++) {
416 		proc = &gotd.procs[i];
417 		if (proc->iev.ibuf.fd == fd)
418 			return proc;
419 	}
420 
421 	return NULL;
422 }
423 
424 static const struct got_error *
425 forward_list_refs_request(struct gotd_client *client, struct imsg *imsg)
426 {
427 	const struct got_error *err;
428 	struct gotd_imsg_list_refs ireq;
429 	struct gotd_imsg_list_refs_internal ilref;
430 	struct gotd_child_proc *proc = NULL;
431 	size_t datalen;
432 	int fd = -1;
433 
434 	log_debug("list-refs request from uid %d", client->euid);
435 
436 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
437 	if (datalen != sizeof(ireq))
438 		return got_error(GOT_ERR_PRIVSEP_LEN);
439 
440 	memcpy(&ireq, imsg->data, datalen);
441 
442 	memset(&ilref, 0, sizeof(ilref));
443 	ilref.client_id = client->id;
444 
445 	if (ireq.client_is_reading) {
446 		err = ensure_client_is_not_writing(client);
447 		if (err)
448 			return err;
449 		client->repo_read = find_proc_by_repo_name(PROC_REPO_READ,
450 		    ireq.repo_name);
451 		if (client->repo_read == NULL)
452 			return got_error(GOT_ERR_NOT_GIT_REPO);
453 	} else {
454 		err = ensure_client_is_not_reading(client);
455 		if (err)
456 			return err;
457 		client->repo_write = find_proc_by_repo_name(PROC_REPO_WRITE,
458 		    ireq.repo_name);
459 		if (client->repo_write == NULL)
460 			return got_error(GOT_ERR_NOT_GIT_REPO);
461 	}
462 
463 	fd = dup(client->fd);
464 	if (fd == -1)
465 		return got_error_from_errno("dup");
466 
467 	proc = get_client_proc(client);
468 	if (gotd_imsg_compose_event(&proc->iev,
469 	    GOTD_IMSG_LIST_REFS_INTERNAL, PROC_GOTD, fd,
470 	    &ilref, sizeof(ilref)) == -1) {
471 		err = got_error_from_errno("imsg compose WANT");
472 		close(fd);
473 		return err;
474 	}
475 
476 	return NULL;
477 }
478 
479 static const struct got_error *
480 forward_want(struct gotd_client *client, struct imsg *imsg)
481 {
482 	struct gotd_imsg_want ireq;
483 	struct gotd_imsg_want iwant;
484 	size_t datalen;
485 
486 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
487 	if (datalen != sizeof(ireq))
488 		return got_error(GOT_ERR_PRIVSEP_LEN);
489 
490 	memcpy(&ireq, imsg->data, datalen);
491 
492 	memset(&iwant, 0, sizeof(iwant));
493 	memcpy(iwant.object_id, ireq.object_id, SHA1_DIGEST_LENGTH);
494 	iwant.client_id = client->id;
495 
496 	if (gotd_imsg_compose_event(&client->repo_read->iev, GOTD_IMSG_WANT,
497 	    PROC_GOTD, -1, &iwant, sizeof(iwant)) == -1)
498 		return got_error_from_errno("imsg compose WANT");
499 
500 	return NULL;
501 }
502 
503 static const struct got_error *
504 forward_ref_update(struct gotd_client *client, struct imsg *imsg)
505 {
506 	const struct got_error *err = NULL;
507 	struct gotd_imsg_ref_update ireq;
508 	struct gotd_imsg_ref_update *iref = NULL;
509 	size_t datalen;
510 
511 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
512 	if (datalen < sizeof(ireq))
513 		return got_error(GOT_ERR_PRIVSEP_LEN);
514 	memcpy(&ireq, imsg->data, sizeof(ireq));
515 	if (datalen != sizeof(ireq) + ireq.name_len)
516 		return got_error(GOT_ERR_PRIVSEP_LEN);
517 
518 	iref = malloc(datalen);
519 	if (iref == NULL)
520 		return got_error_from_errno("malloc");
521 	memcpy(iref, imsg->data, datalen);
522 
523 	iref->client_id = client->id;
524 	if (gotd_imsg_compose_event(&client->repo_write->iev,
525 	    GOTD_IMSG_REF_UPDATE, PROC_GOTD, -1, iref, datalen) == -1)
526 		err = got_error_from_errno("imsg compose REF_UPDATE");
527 	free(iref);
528 	return err;
529 }
530 
531 static const struct got_error *
532 forward_have(struct gotd_client *client, struct imsg *imsg)
533 {
534 	struct gotd_imsg_have ireq;
535 	struct gotd_imsg_have ihave;
536 	size_t datalen;
537 
538 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
539 	if (datalen != sizeof(ireq))
540 		return got_error(GOT_ERR_PRIVSEP_LEN);
541 
542 	memcpy(&ireq, imsg->data, datalen);
543 
544 	memset(&ihave, 0, sizeof(ihave));
545 	memcpy(ihave.object_id, ireq.object_id, SHA1_DIGEST_LENGTH);
546 	ihave.client_id = client->id;
547 
548 	if (gotd_imsg_compose_event(&client->repo_read->iev, GOTD_IMSG_HAVE,
549 	    PROC_GOTD, -1, &ihave, sizeof(ihave)) == -1)
550 		return got_error_from_errno("imsg compose HAVE");
551 
552 	return NULL;
553 }
554 
555 static int
556 client_has_capability(struct gotd_client *client, const char *capastr)
557 {
558 	struct gotd_client_capability *capa;
559 	size_t i;
560 
561 	if (client->ncapabilities == 0)
562 		return 0;
563 
564 	for (i = 0; i < client->ncapabilities; i++) {
565 		capa = &client->capabilities[i];
566 		if (strcmp(capa->key, capastr) == 0)
567 			return 1;
568 	}
569 
570 	return 0;
571 }
572 
573 static const struct got_error *
574 recv_capabilities(struct gotd_client *client, struct imsg *imsg)
575 {
576 	struct gotd_imsg_capabilities icapas;
577 	size_t datalen;
578 
579 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
580 	if (datalen != sizeof(icapas))
581 		return got_error(GOT_ERR_PRIVSEP_LEN);
582 	memcpy(&icapas, imsg->data, sizeof(icapas));
583 
584 	client->ncapa_alloc = icapas.ncapabilities;
585 	client->capabilities = calloc(client->ncapa_alloc,
586 	    sizeof(*client->capabilities));
587 	if (client->capabilities == NULL) {
588 		client->ncapa_alloc = 0;
589 		return got_error_from_errno("calloc");
590 	}
591 
592 	log_debug("expecting %zu capabilities from uid %d",
593 	    client->ncapa_alloc, client->euid);
594 	return NULL;
595 }
596 
597 static const struct got_error *
598 recv_capability(struct gotd_client *client, struct imsg *imsg)
599 {
600 	struct gotd_imsg_capability icapa;
601 	struct gotd_client_capability *capa;
602 	size_t datalen;
603 	char *key, *value = NULL;
604 
605 	if (client->capabilities == NULL ||
606 	    client->ncapabilities >= client->ncapa_alloc) {
607 		return got_error_msg(GOT_ERR_BAD_REQUEST,
608 		    "unexpected capability received");
609 	}
610 
611 	memset(&icapa, 0, sizeof(icapa));
612 
613 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
614 	if (datalen < sizeof(icapa))
615 		return got_error(GOT_ERR_PRIVSEP_LEN);
616 	memcpy(&icapa, imsg->data, sizeof(icapa));
617 
618 	if (datalen != sizeof(icapa) + icapa.key_len + icapa.value_len)
619 		return got_error(GOT_ERR_PRIVSEP_LEN);
620 
621 	key = malloc(icapa.key_len + 1);
622 	if (key == NULL)
623 		return got_error_from_errno("malloc");
624 	if (icapa.value_len > 0) {
625 		value = malloc(icapa.value_len + 1);
626 		if (value == NULL) {
627 			free(key);
628 			return got_error_from_errno("malloc");
629 		}
630 	}
631 
632 	memcpy(key, imsg->data + sizeof(icapa), icapa.key_len);
633 	key[icapa.key_len] = '\0';
634 	if (value) {
635 		memcpy(value, imsg->data + sizeof(icapa) + icapa.key_len,
636 		    icapa.value_len);
637 		value[icapa.value_len] = '\0';
638 	}
639 
640 	capa = &client->capabilities[client->ncapabilities++];
641 	capa->key = key;
642 	capa->value = value;
643 
644 	if (value)
645 		log_debug("uid %d: capability %s=%s", client->euid, key, value);
646 	else
647 		log_debug("uid %d: capability %s", client->euid, key);
648 
649 	return NULL;
650 }
651 
652 static const struct got_error *
653 send_packfile(struct gotd_client *client)
654 {
655 	const struct got_error *err = NULL;
656 	struct gotd_imsg_send_packfile ipack;
657 	struct gotd_imsg_packfile_pipe ipipe;
658 	int pipe[2];
659 
660 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe) == -1)
661 		return got_error_from_errno("socketpair");
662 
663 	memset(&ipack, 0, sizeof(ipack));
664 	memset(&ipipe, 0, sizeof(ipipe));
665 
666 	ipack.client_id = client->id;
667 	if (client_has_capability(client, GOT_CAPA_SIDE_BAND_64K))
668 		ipack.report_progress = 1;
669 
670 	client->delta_cache_fd = got_opentempfd();
671 	if (client->delta_cache_fd == -1)
672 		return got_error_from_errno("got_opentempfd");
673 
674 	if (gotd_imsg_compose_event(&client->repo_read->iev,
675 	    GOTD_IMSG_SEND_PACKFILE, PROC_GOTD, client->delta_cache_fd,
676 	    &ipack, sizeof(ipack)) == -1) {
677 		err = got_error_from_errno("imsg compose SEND_PACKFILE");
678 		close(pipe[0]);
679 		close(pipe[1]);
680 		return err;
681 	}
682 
683 	ipipe.client_id = client->id;
684 
685 	/* Send pack pipe end 0 to repo_read. */
686 	if (gotd_imsg_compose_event(&client->repo_read->iev,
687 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[0],
688 	        &ipipe, sizeof(ipipe)) == -1) {
689 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
690 		close(pipe[1]);
691 		return err;
692 	}
693 
694 	/* Send pack pipe end 1 to gotsh(1) (expects just an fd, no data). */
695 	if (gotd_imsg_compose_event(&client->iev,
696 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[1], NULL, 0) == -1)
697 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
698 
699 	return err;
700 }
701 
702 static const struct got_error *
703 recv_packfile(struct gotd_client *client)
704 {
705 	const struct got_error *err = NULL;
706 	struct gotd_imsg_recv_packfile ipack;
707 	struct gotd_imsg_packfile_pipe ipipe;
708 	struct gotd_imsg_packidx_file ifile;
709 	char *basepath = NULL, *pack_path = NULL, *idx_path = NULL;
710 	int packfd = -1, idxfd = -1;
711 	int pipe[2] = { -1, -1 };
712 
713 	if (client->packfile_path) {
714 		return got_error_fmt(GOT_ERR_PRIVSEP_MSG,
715 		    "uid %d already has a pack file", client->euid);
716 	}
717 
718 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe) == -1)
719 		return got_error_from_errno("socketpair");
720 
721 	memset(&ipipe, 0, sizeof(ipipe));
722 	ipipe.client_id = client->id;
723 
724 	if (gotd_imsg_compose_event(&client->repo_write->iev,
725 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[0],
726 	        &ipipe, sizeof(ipipe)) == -1) {
727 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
728 		pipe[0] = -1;
729 		goto done;
730 	}
731 	pipe[0] = -1;
732 
733 	if (gotd_imsg_compose_event(&client->repo_write->iev,
734 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[1],
735 	        &ipipe, sizeof(ipipe)) == -1)
736 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
737 	pipe[1] = -1;
738 
739 	if (asprintf(&basepath, "%s/%s/receiving-from-uid-%d.pack",
740 	    client->repo_write->chroot_path, GOT_OBJECTS_PACK_DIR,
741 	    client->euid) == -1) {
742 		err = got_error_from_errno("asprintf");
743 		goto done;
744 	}
745 
746 	err = got_opentemp_named_fd(&pack_path, &packfd, basepath);
747 	if (err)
748 		goto done;
749 
750 	free(basepath);
751 	if (asprintf(&basepath, "%s/%s/receiving-from-uid-%d.idx",
752 	    client->repo_write->chroot_path, GOT_OBJECTS_PACK_DIR,
753 	    client->euid) == -1) {
754 		err = got_error_from_errno("asprintf");
755 		basepath = NULL;
756 		goto done;
757 	}
758 	err = got_opentemp_named_fd(&idx_path, &idxfd, basepath);
759 	if (err)
760 		goto done;
761 
762 	memset(&ifile, 0, sizeof(ifile));
763 	ifile.client_id = client->id;
764 	if (gotd_imsg_compose_event(&client->repo_write->iev,
765 	    GOTD_IMSG_PACKIDX_FILE, PROC_GOTD, idxfd,
766 	    &ifile, sizeof(ifile)) == -1) {
767 		err = got_error_from_errno("imsg compose PACKIDX_FILE");
768 		idxfd = -1;
769 		goto done;
770 	}
771 	idxfd = -1;
772 
773 	memset(&ipack, 0, sizeof(ipack));
774 	ipack.client_id = client->id;
775 	if (client_has_capability(client, GOT_CAPA_REPORT_STATUS))
776 		ipack.report_status = 1;
777 
778 	if (gotd_imsg_compose_event(&client->repo_write->iev,
779 	    GOTD_IMSG_RECV_PACKFILE, PROC_GOTD, packfd,
780 	    &ipack, sizeof(ipack)) == -1) {
781 		err = got_error_from_errno("imsg compose RECV_PACKFILE");
782 		packfd = -1;
783 		goto done;
784 	}
785 	packfd = -1;
786 
787 done:
788 	free(basepath);
789 	if (pipe[0] != -1 && close(pipe[0]) == -1 && err == NULL)
790 		err = got_error_from_errno("close");
791 	if (pipe[1] != -1 && close(pipe[1]) == -1 && err == NULL)
792 		err = got_error_from_errno("close");
793 	if (packfd != -1 && close(packfd) == -1 && err == NULL)
794 		err = got_error_from_errno("close");
795 	if (idxfd != -1 && close(idxfd) == -1 && err == NULL)
796 		err = got_error_from_errno("close");
797 	if (err) {
798 		free(pack_path);
799 		free(idx_path);
800 	} else {
801 		client->packfile_path = pack_path;
802 		client->packidx_path = idx_path;
803 	}
804 	return err;
805 }
806 
807 static void
808 gotd_request(int fd, short events, void *arg)
809 {
810 	struct gotd_imsgev *iev = arg;
811 	struct imsgbuf *ibuf = &iev->ibuf;
812 	struct gotd_client *client = iev->handler_arg;
813 	const struct got_error *err = NULL;
814 	struct imsg imsg;
815 	ssize_t n;
816 
817 	if (events & EV_WRITE) {
818 		while (ibuf->w.queued) {
819 			n = msgbuf_write(&ibuf->w);
820 			if (n == -1 && errno == EPIPE) {
821 				/*
822 				 * The client has closed its socket.
823 				 * This can happen when Git clients are
824 				 * done sending pack file data.
825 				*/
826 				msgbuf_clear(&ibuf->w);
827 				continue;
828 			} else if (n == -1 && errno != EAGAIN) {
829 				err = got_error_from_errno("imsg_flush");
830 				disconnect_on_error(client, err);
831 				return;
832 			}
833 			if (n == 0) {
834 				/* Connection closed. */
835 				err = got_error(GOT_ERR_EOF);
836 				disconnect_on_error(client, err);
837 				return;
838 			}
839 		}
840 	}
841 
842 	if ((events & EV_READ) == 0)
843 		return;
844 
845 	memset(&imsg, 0, sizeof(imsg));
846 
847 	while (err == NULL) {
848 		err = gotd_imsg_recv(&imsg, ibuf, 0);
849 		if (err) {
850 			if (err->code == GOT_ERR_PRIVSEP_READ)
851 				err = NULL;
852 			break;
853 		}
854 
855 		evtimer_del(&client->tmo);
856 
857 		switch (imsg.hdr.type) {
858 		case GOTD_IMSG_LIST_REFS:
859 			if (client->state != GOTD_STATE_EXPECT_LIST_REFS) {
860 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
861 				    "unexpected list-refs request received");
862 				break;
863 			}
864 			err = forward_list_refs_request(client, &imsg);
865 			if (err)
866 				break;
867 			client->state = GOTD_STATE_EXPECT_CAPABILITIES;
868 			log_debug("uid %d: expecting capabilities",
869 			    client->euid);
870 			break;
871 		case GOTD_IMSG_CAPABILITIES:
872 			if (client->state != GOTD_STATE_EXPECT_CAPABILITIES) {
873 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
874 				    "unexpected capabilities received");
875 				break;
876 			}
877 			log_debug("receiving capabilities from uid %d",
878 			    client->euid);
879 			err = recv_capabilities(client, &imsg);
880 			break;
881 		case GOTD_IMSG_CAPABILITY:
882 			if (client->state != GOTD_STATE_EXPECT_CAPABILITIES) {
883 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
884 				    "unexpected capability received");
885 				break;
886 			}
887 			err = recv_capability(client, &imsg);
888 			if (err || client->ncapabilities < client->ncapa_alloc)
889 				break;
890 			if (client_is_reading(client)) {
891 				client->state = GOTD_STATE_EXPECT_WANT;
892 				log_debug("uid %d: expecting want-lines",
893 				    client->euid);
894 			} else if (client_is_writing(client)) {
895 				client->state = GOTD_STATE_EXPECT_REF_UPDATE;
896 				log_debug("uid %d: expecting ref-update-lines",
897 				    client->euid);
898 			} else
899 				fatalx("client %d is both reading and writing",
900 				    client->euid);
901 			break;
902 		case GOTD_IMSG_WANT:
903 			if (client->state != GOTD_STATE_EXPECT_WANT) {
904 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
905 				    "unexpected want-line received");
906 				break;
907 			}
908 			log_debug("received want-line from uid %d",
909 			    client->euid);
910 			err = ensure_client_is_reading(client);
911 			if (err)
912 				break;
913 			err = forward_want(client, &imsg);
914 			break;
915 		case GOTD_IMSG_REF_UPDATE:
916 			if (client->state != GOTD_STATE_EXPECT_REF_UPDATE) {
917 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
918 				    "unexpected ref-update-line received");
919 				break;
920 			}
921 			log_debug("received ref-update-line from uid %d",
922 			    client->euid);
923 			err = ensure_client_is_writing(client);
924 			if (err)
925 				break;
926 			err = forward_ref_update(client, &imsg);
927 			if (err)
928 				break;
929 			client->state = GOTD_STATE_EXPECT_MORE_REF_UPDATES;
930 			break;
931 		case GOTD_IMSG_HAVE:
932 			if (client->state != GOTD_STATE_EXPECT_HAVE) {
933 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
934 				    "unexpected have-line received");
935 				break;
936 			}
937 			log_debug("received have-line from uid %d",
938 			    client->euid);
939 			err = ensure_client_is_reading(client);
940 			if (err)
941 				break;
942 			err = forward_have(client, &imsg);
943 			if (err)
944 				break;
945 			break;
946 		case GOTD_IMSG_FLUSH:
947 			if (client->state == GOTD_STATE_EXPECT_WANT ||
948 			    client->state == GOTD_STATE_EXPECT_HAVE) {
949 				err = ensure_client_is_reading(client);
950 				if (err)
951 					break;
952 			} else if (client->state ==
953 			    GOTD_STATE_EXPECT_MORE_REF_UPDATES) {
954 				err = ensure_client_is_writing(client);
955 				if (err)
956 					break;
957 			} else {
958 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
959 				    "unexpected flush-pkt received");
960 				break;
961 			}
962 			log_debug("received flush-pkt from uid %d",
963 			    client->euid);
964 			if (client->state == GOTD_STATE_EXPECT_WANT) {
965 				client->state = GOTD_STATE_EXPECT_HAVE;
966 				log_debug("uid %d: expecting have-lines",
967 				    client->euid);
968 			} else if (client->state == GOTD_STATE_EXPECT_HAVE) {
969 				client->state = GOTD_STATE_EXPECT_DONE;
970 				log_debug("uid %d: expecting 'done'",
971 				    client->euid);
972 			} else if (client->state ==
973 			    GOTD_STATE_EXPECT_MORE_REF_UPDATES) {
974 				client->state = GOTD_STATE_EXPECT_PACKFILE;
975 				log_debug("uid %d: expecting packfile",
976 				    client->euid);
977 				err = recv_packfile(client);
978 			} else {
979 				/* should not happen, see above */
980 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
981 				    "unexpected client state");
982 				break;
983 			}
984 			break;
985 		case GOTD_IMSG_DONE:
986 			if (client->state != GOTD_STATE_EXPECT_HAVE &&
987 			    client->state != GOTD_STATE_EXPECT_DONE) {
988 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
989 				    "unexpected flush-pkt received");
990 				break;
991 			}
992 			log_debug("received 'done' from uid %d", client->euid);
993 			err = ensure_client_is_reading(client);
994 			if (err)
995 				break;
996 			client->state = GOTD_STATE_DONE;
997 			err = send_packfile(client);
998 			break;
999 		default:
1000 			err = got_error(GOT_ERR_PRIVSEP_MSG);
1001 			break;
1002 		}
1003 
1004 		imsg_free(&imsg);
1005 	}
1006 
1007 	if (err) {
1008 		if (err->code != GOT_ERR_EOF ||
1009 		    client->state != GOTD_STATE_EXPECT_PACKFILE)
1010 			disconnect_on_error(client, err);
1011 	} else {
1012 		gotd_imsg_event_add(&client->iev);
1013 		evtimer_add(&client->tmo, &timeout);
1014 	}
1015 }
1016 
1017 static void
1018 gotd_request_timeout(int fd, short events, void *arg)
1019 {
1020 	struct gotd_client *client = arg;
1021 
1022 	log_debug("disconnecting uid %d due to timeout", client->euid);
1023 	disconnect(client);
1024 }
1025 
1026 static void
1027 gotd_accept(int fd, short event, void *arg)
1028 {
1029 	struct sockaddr_storage ss;
1030 	struct timeval backoff;
1031 	socklen_t len;
1032 	int s = -1;
1033 	struct gotd_client *client = NULL;
1034 	uid_t euid;
1035 	gid_t egid;
1036 
1037 	backoff.tv_sec = 1;
1038 	backoff.tv_usec = 0;
1039 
1040 	if (event_add(&gotd.ev, NULL) == -1) {
1041 		log_warn("event_add");
1042 		return;
1043 	}
1044 	if (event & EV_TIMEOUT)
1045 		return;
1046 
1047 	len = sizeof(ss);
1048 
1049 	s = accept_reserve(fd, (struct sockaddr *)&ss, &len, GOTD_FD_RESERVE,
1050 	    &inflight);
1051 
1052 	if (s == -1) {
1053 		switch (errno) {
1054 		case EINTR:
1055 		case EWOULDBLOCK:
1056 		case ECONNABORTED:
1057 			return;
1058 		case EMFILE:
1059 		case ENFILE:
1060 			event_del(&gotd.ev);
1061 			evtimer_add(&gotd.pause, &backoff);
1062 			return;
1063 		default:
1064 			log_warn("%s: accept", __func__);
1065 			return;
1066 		}
1067 	}
1068 
1069 	if (client_cnt >= GOTD_MAXCLIENTS)
1070 		goto err;
1071 
1072 	if (getpeereid(s, &euid, &egid) == -1) {
1073 		log_warn("%s: getpeereid", __func__);
1074 		goto err;
1075 	}
1076 
1077 	client = calloc(1, sizeof(*client));
1078 	if (client == NULL) {
1079 		log_warn("%s: calloc", __func__);
1080 		goto err;
1081 	}
1082 
1083 	client->state = GOTD_STATE_EXPECT_LIST_REFS;
1084 	client->id = get_client_id();
1085 	client->fd = s;
1086 	s = -1;
1087 	client->delta_cache_fd = -1;
1088 	client->euid = euid;
1089 	client->egid = egid;
1090 	client->nref_updates = -1;
1091 
1092 	imsg_init(&client->iev.ibuf, client->fd);
1093 	client->iev.handler = gotd_request;
1094 	client->iev.events = EV_READ;
1095 	client->iev.handler_arg = client;
1096 
1097 	event_set(&client->iev.ev, client->fd, EV_READ, gotd_request,
1098 	    &client->iev);
1099 	gotd_imsg_event_add(&client->iev);
1100 
1101 	evtimer_set(&client->tmo, gotd_request_timeout, client);
1102 
1103 	add_client(client);
1104 	log_debug("%s: new client uid %d connected on fd %d", __func__,
1105 	    client->euid, client->fd);
1106 	return;
1107 err:
1108 	inflight--;
1109 	if (s != -1)
1110 		close(s);
1111 	free(client);
1112 }
1113 
1114 static void
1115 gotd_accept_paused(int fd, short event, void *arg)
1116 {
1117 	event_add(&gotd.ev, NULL);
1118 }
1119 
1120 static const char *gotd_proc_names[PROC_MAX] = {
1121 	"parent",
1122 	"repo_read",
1123 	"repo_write"
1124 };
1125 
1126 static struct gotd_child_proc *
1127 get_proc_for_pid(pid_t pid)
1128 {
1129 	struct gotd_child_proc *proc;
1130 	int i;
1131 
1132 	for (i = 0; i < gotd.nprocs; i++) {
1133 		proc = &gotd.procs[i];
1134 		if (proc->pid == pid)
1135 			return proc;
1136 	}
1137 
1138 	return NULL;
1139 }
1140 
1141 static void
1142 kill_proc(struct gotd_child_proc *proc, int fatal)
1143 {
1144 	if (fatal) {
1145 		log_warnx("sending SIGKILL to PID %d", proc->pid);
1146 		kill(proc->pid, SIGKILL);
1147 	} else
1148 		kill(proc->pid, SIGTERM);
1149 }
1150 
1151 static void
1152 gotd_shutdown(void)
1153 {
1154 	pid_t	 pid;
1155 	int	 status, i;
1156 	struct gotd_child_proc *proc;
1157 
1158 	for (i = 0; i < gotd.nprocs; i++) {
1159 		proc = &gotd.procs[i];
1160 		msgbuf_clear(&proc->iev.ibuf.w);
1161 		close(proc->iev.ibuf.fd);
1162 		kill_proc(proc, 0);
1163 	}
1164 
1165 	log_debug("waiting for children to terminate");
1166 	do {
1167 		pid = wait(&status);
1168 		if (pid == -1) {
1169 			if (errno != EINTR && errno != ECHILD)
1170 				fatal("wait");
1171 		} else if (WIFSIGNALED(status)) {
1172 			proc = get_proc_for_pid(pid);
1173 			log_warnx("%s %s child process terminated; signal %d",
1174 			    proc ? gotd_proc_names[proc->type] : "",
1175 			    proc ? proc->chroot_path : "", WTERMSIG(status));
1176 		}	
1177 	} while (pid != -1 || (pid == -1 && errno == EINTR));
1178 
1179 	log_info("terminating");
1180 	exit(0);
1181 }
1182 
1183 void
1184 gotd_sighdlr(int sig, short event, void *arg)
1185 {
1186 	/*
1187 	 * Normal signal handler rules don't apply because libevent
1188 	 * decouples for us.
1189 	 */
1190 
1191 	switch (sig) {
1192 	case SIGHUP:
1193 		log_info("%s: ignoring SIGHUP", __func__);
1194 		break;
1195 	case SIGUSR1:
1196 		log_info("%s: ignoring SIGUSR1", __func__);
1197 		break;
1198 	case SIGTERM:
1199 	case SIGINT:
1200 		gotd_shutdown();
1201 		log_warnx("gotd terminating");
1202 		exit(0);
1203 		break;
1204 	default:
1205 		fatalx("unexpected signal");
1206 	}
1207 }
1208 
1209 static const struct got_error *
1210 ensure_proc_is_reading(struct gotd_client *client,
1211     struct gotd_child_proc *proc)
1212 {
1213 	if (!client_is_reading(client)) {
1214 		kill_proc(proc, 1);
1215 		return got_error_fmt(GOT_ERR_BAD_PACKET,
1216 		    "PID %d handled a read-request for uid %d but this "
1217 		    "user is not reading from a repository", proc->pid,
1218 		    client->euid);
1219 	}
1220 
1221 	return NULL;
1222 }
1223 
1224 static const struct got_error *
1225 ensure_proc_is_writing(struct gotd_client *client,
1226     struct gotd_child_proc *proc)
1227 {
1228 	if (!client_is_writing(client)) {
1229 		kill_proc(proc, 1);
1230 		return got_error_fmt(GOT_ERR_BAD_PACKET,
1231 		    "PID %d handled a write-request for uid %d but this "
1232 		    "user is not writing to a repository", proc->pid,
1233 		    client->euid);
1234 	}
1235 
1236 	return NULL;
1237 }
1238 
1239 static int
1240 verify_imsg_src(struct gotd_client *client, struct gotd_child_proc *proc,
1241     struct imsg *imsg)
1242 {
1243 	const struct got_error *err;
1244 	struct gotd_child_proc *client_proc;
1245 	int ret = 0;
1246 
1247 	client_proc = get_client_proc(client);
1248 	if (proc->pid != client_proc->pid) {
1249 		kill_proc(proc, 1);
1250 		log_warnx("received message from PID %d for uid %d, while "
1251 		    "PID %d is the process serving this user",
1252 		    proc->pid, client->euid, client_proc->pid);
1253 		return 0;
1254 	}
1255 
1256 	switch (imsg->hdr.type) {
1257 	case GOTD_IMSG_ERROR:
1258 		ret = 1;
1259 		break;
1260 	case GOTD_IMSG_PACKFILE_DONE:
1261 		err = ensure_proc_is_reading(client, proc);
1262 		if (err)
1263 			log_warnx("uid %d: %s", client->euid, err->msg);
1264 		else
1265 			ret = 1;
1266 		break;
1267 	case GOTD_IMSG_PACKFILE_INSTALL:
1268 	case GOTD_IMSG_REF_UPDATES_START:
1269 	case GOTD_IMSG_REF_UPDATE:
1270 		err = ensure_proc_is_writing(client, proc);
1271 		if (err)
1272 			log_warnx("uid %d: %s", client->euid, err->msg);
1273 		else
1274 			ret = 1;
1275 		break;
1276 	default:
1277 		log_debug("%s: unexpected imsg %d", __func__, imsg->hdr.type);
1278 		break;
1279 	}
1280 
1281 	return ret;
1282 }
1283 
1284 static const struct got_error *
1285 recv_packfile_done(uint32_t *client_id, struct imsg *imsg)
1286 {
1287 	struct gotd_imsg_packfile_done idone;
1288 	size_t datalen;
1289 
1290 	log_debug("packfile-done received");
1291 
1292 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1293 	if (datalen != sizeof(idone))
1294 		return got_error(GOT_ERR_PRIVSEP_LEN);
1295 	memcpy(&idone, imsg->data, sizeof(idone));
1296 
1297 	*client_id = idone.client_id;
1298 	return NULL;
1299 }
1300 
1301 static const struct got_error *
1302 recv_packfile_install(uint32_t *client_id, struct imsg *imsg)
1303 {
1304 	struct gotd_imsg_packfile_install inst;
1305 	size_t datalen;
1306 
1307 	log_debug("packfile-install received");
1308 
1309 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1310 	if (datalen != sizeof(inst))
1311 		return got_error(GOT_ERR_PRIVSEP_LEN);
1312 	memcpy(&inst, imsg->data, sizeof(inst));
1313 
1314 	*client_id = inst.client_id;
1315 	return NULL;
1316 }
1317 
1318 static const struct got_error *
1319 recv_ref_updates_start(uint32_t *client_id, struct imsg *imsg)
1320 {
1321 	struct gotd_imsg_ref_updates_start istart;
1322 	size_t datalen;
1323 
1324 	log_debug("ref-updates-start received");
1325 
1326 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1327 	if (datalen != sizeof(istart))
1328 		return got_error(GOT_ERR_PRIVSEP_LEN);
1329 	memcpy(&istart, imsg->data, sizeof(istart));
1330 
1331 	*client_id = istart.client_id;
1332 	return NULL;
1333 }
1334 
1335 static const struct got_error *
1336 recv_ref_update(uint32_t *client_id, struct imsg *imsg)
1337 {
1338 	struct gotd_imsg_ref_update iref;
1339 	size_t datalen;
1340 
1341 	log_debug("ref-update received");
1342 
1343 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1344 	if (datalen < sizeof(iref))
1345 		return got_error(GOT_ERR_PRIVSEP_LEN);
1346 	memcpy(&iref, imsg->data, sizeof(iref));
1347 
1348 	*client_id = iref.client_id;
1349 	return NULL;
1350 }
1351 
1352 static const struct got_error *
1353 send_ref_update_ok(struct gotd_client *client,
1354     struct gotd_imsg_ref_update *iref, const char *refname)
1355 {
1356 	struct gotd_imsg_ref_update_ok iok;
1357 	struct ibuf *wbuf;
1358 	size_t len;
1359 
1360 	memset(&iok, 0, sizeof(iok));
1361 	iok.client_id = client->id;
1362 	memcpy(iok.old_id, iref->old_id, SHA1_DIGEST_LENGTH);
1363 	memcpy(iok.new_id, iref->new_id, SHA1_DIGEST_LENGTH);
1364 	iok.name_len = strlen(refname);
1365 
1366 	len = sizeof(iok) + iok.name_len;
1367 	wbuf = imsg_create(&client->iev.ibuf, GOTD_IMSG_REF_UPDATE_OK,
1368 	    PROC_GOTD, gotd.pid, len);
1369 	if (wbuf == NULL)
1370 		return got_error_from_errno("imsg_create REF_UPDATE_OK");
1371 
1372 	if (imsg_add(wbuf, &iok, sizeof(iok)) == -1)
1373 		return got_error_from_errno("imsg_add REF_UPDATE_OK");
1374 	if (imsg_add(wbuf, refname, iok.name_len) == -1)
1375 		return got_error_from_errno("imsg_add REF_UPDATE_OK");
1376 
1377 	wbuf->fd = -1;
1378 	imsg_close(&client->iev.ibuf, wbuf);
1379 	gotd_imsg_event_add(&client->iev);
1380 	return NULL;
1381 }
1382 
1383 static void
1384 send_refs_updated(struct gotd_client *client)
1385 {
1386 	if (gotd_imsg_compose_event(&client->iev,
1387 	    GOTD_IMSG_REFS_UPDATED, PROC_GOTD, -1, NULL, 0) == -1)
1388 		log_warn("imsg compose REFS_UPDATED");
1389 }
1390 
1391 static const struct got_error *
1392 send_ref_update_ng(struct gotd_client *client,
1393     struct gotd_imsg_ref_update *iref, const char *refname,
1394     const char *reason)
1395 {
1396 	const struct got_error *ng_err;
1397 	struct gotd_imsg_ref_update_ng ing;
1398 	struct ibuf *wbuf;
1399 	size_t len;
1400 
1401 	memset(&ing, 0, sizeof(ing));
1402 	ing.client_id = client->id;
1403 	memcpy(ing.old_id, iref->old_id, SHA1_DIGEST_LENGTH);
1404 	memcpy(ing.new_id, iref->new_id, SHA1_DIGEST_LENGTH);
1405 	ing.name_len = strlen(refname);
1406 
1407 	ng_err = got_error_fmt(GOT_ERR_REF_BUSY, "%s", reason);
1408 	ing.reason_len = strlen(ng_err->msg);
1409 
1410 	len = sizeof(ing) + ing.name_len + ing.reason_len;
1411 	wbuf = imsg_create(&client->iev.ibuf, GOTD_IMSG_REF_UPDATE_NG,
1412 	    PROC_GOTD, gotd.pid, len);
1413 	if (wbuf == NULL)
1414 		return got_error_from_errno("imsg_create REF_UPDATE_NG");
1415 
1416 	if (imsg_add(wbuf, &ing, sizeof(ing)) == -1)
1417 		return got_error_from_errno("imsg_add REF_UPDATE_NG");
1418 	if (imsg_add(wbuf, refname, ing.name_len) == -1)
1419 		return got_error_from_errno("imsg_add REF_UPDATE_NG");
1420 	if (imsg_add(wbuf, ng_err->msg, ing.reason_len) == -1)
1421 		return got_error_from_errno("imsg_add REF_UPDATE_NG");
1422 
1423 	wbuf->fd = -1;
1424 	imsg_close(&client->iev.ibuf, wbuf);
1425 	gotd_imsg_event_add(&client->iev);
1426 	return NULL;
1427 }
1428 
1429 static const struct got_error *
1430 install_pack(struct gotd_client *client, const char *repo_path,
1431     struct imsg *imsg)
1432 {
1433 	const struct got_error *err = NULL;
1434 	struct gotd_imsg_packfile_install inst;
1435 	char hex[SHA1_DIGEST_STRING_LENGTH];
1436 	size_t datalen;
1437 	char *packfile_path = NULL, *packidx_path = NULL;
1438 
1439 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1440 	if (datalen != sizeof(inst))
1441 		return got_error(GOT_ERR_PRIVSEP_LEN);
1442 	memcpy(&inst, imsg->data, sizeof(inst));
1443 
1444 	if (client->packfile_path == NULL)
1445 		return got_error_msg(GOT_ERR_BAD_REQUEST,
1446 		    "client has no pack file");
1447 	if (client->packidx_path == NULL)
1448 		return got_error_msg(GOT_ERR_BAD_REQUEST,
1449 		    "client has no pack file index");
1450 
1451 	if (got_sha1_digest_to_str(inst.pack_sha1, hex, sizeof(hex)) == NULL)
1452 		return got_error_msg(GOT_ERR_NO_SPACE,
1453 		    "could not convert pack file SHA1 to hex");
1454 
1455 	if (asprintf(&packfile_path, "/%s/%s/pack-%s.pack",
1456 	    repo_path, GOT_OBJECTS_PACK_DIR, hex) == -1) {
1457 		err = got_error_from_errno("asprintf");
1458 		goto done;
1459 	}
1460 
1461 	if (asprintf(&packidx_path, "/%s/%s/pack-%s.idx",
1462 	    repo_path, GOT_OBJECTS_PACK_DIR, hex) == -1) {
1463 		err = got_error_from_errno("asprintf");
1464 		goto done;
1465 	}
1466 
1467 	if (rename(client->packfile_path, packfile_path) == -1) {
1468 		err = got_error_from_errno3("rename", client->packfile_path,
1469 		    packfile_path);
1470 		goto done;
1471 	}
1472 
1473 	free(client->packfile_path);
1474 	client->packfile_path = NULL;
1475 
1476 	if (rename(client->packidx_path, packidx_path) == -1) {
1477 		err = got_error_from_errno3("rename", client->packidx_path,
1478 		    packidx_path);
1479 		goto done;
1480 	}
1481 
1482 	free(client->packidx_path);
1483 	client->packidx_path = NULL;
1484 done:
1485 	free(packfile_path);
1486 	free(packidx_path);
1487 	return err;
1488 }
1489 
1490 static const struct got_error *
1491 begin_ref_updates(struct gotd_client *client, struct imsg *imsg)
1492 {
1493 	struct gotd_imsg_ref_updates_start istart;
1494 	size_t datalen;
1495 
1496 	if (client->nref_updates != -1)
1497 		return got_error(GOT_ERR_PRIVSEP_MSG);
1498 
1499 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1500 	if (datalen != sizeof(istart))
1501 		return got_error(GOT_ERR_PRIVSEP_LEN);
1502 	memcpy(&istart, imsg->data, sizeof(istart));
1503 
1504 	if (istart.nref_updates <= 0)
1505 		return got_error(GOT_ERR_PRIVSEP_MSG);
1506 
1507 	client->nref_updates = istart.nref_updates;
1508 	return NULL;
1509 }
1510 
1511 static const struct got_error *
1512 update_ref(struct gotd_client *client, const char *repo_path,
1513     struct imsg *imsg)
1514 {
1515 	const struct got_error *err = NULL;
1516 	struct got_repository *repo = NULL;
1517 	struct got_reference *ref = NULL;
1518 	struct gotd_imsg_ref_update iref;
1519 	struct got_object_id old_id, new_id;
1520 	struct got_object_id *id = NULL;
1521 	struct got_object *obj = NULL;
1522 	char *refname = NULL;
1523 	size_t datalen;
1524 	int locked = 0;
1525 
1526 	log_debug("update-ref from uid %d", client->euid);
1527 
1528 	if (client->nref_updates <= 0)
1529 		return got_error(GOT_ERR_PRIVSEP_MSG);
1530 
1531 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1532 	if (datalen < sizeof(iref))
1533 		return got_error(GOT_ERR_PRIVSEP_LEN);
1534 	memcpy(&iref, imsg->data, sizeof(iref));
1535 	if (datalen != sizeof(iref) + iref.name_len)
1536 		return got_error(GOT_ERR_PRIVSEP_LEN);
1537 	refname = malloc(iref.name_len + 1);
1538 	if (refname == NULL)
1539 		return got_error_from_errno("malloc");
1540 	memcpy(refname, imsg->data + sizeof(iref), iref.name_len);
1541 	refname[iref.name_len] = '\0';
1542 
1543 	log_debug("updating ref %s for uid %d", refname, client->euid);
1544 
1545 	err = got_repo_open(&repo, repo_path, NULL, NULL);
1546 	if (err)
1547 		goto done;
1548 
1549 	memcpy(old_id.sha1, iref.old_id, SHA1_DIGEST_LENGTH);
1550 	memcpy(new_id.sha1, iref.new_id, SHA1_DIGEST_LENGTH);
1551 	err = got_object_open(&obj, repo, &new_id);
1552 	if (err)
1553 		goto done;
1554 
1555 	if (iref.ref_is_new) {
1556 		err = got_ref_open(&ref, repo, refname, 0);
1557 		if (err) {
1558 			if (err->code != GOT_ERR_NOT_REF)
1559 				goto done;
1560 			err = got_ref_alloc(&ref, refname, &new_id);
1561 			if (err)
1562 				goto done;
1563 			err = got_ref_write(ref, repo); /* will lock/unlock */
1564 			if (err)
1565 				goto done;
1566 		} else {
1567 			err = got_error_fmt(GOT_ERR_REF_BUSY,
1568 			    "%s has been created by someone else "
1569 			    "while transaction was in progress",
1570 			    got_ref_get_name(ref));
1571 			goto done;
1572 		}
1573 	} else {
1574 		err = got_ref_open(&ref, repo, refname, 1 /* lock */);
1575 		if (err)
1576 			goto done;
1577 		locked = 1;
1578 
1579 		err = got_ref_resolve(&id, repo, ref);
1580 		if (err)
1581 			goto done;
1582 
1583 		if (got_object_id_cmp(id, &old_id) != 0) {
1584 			err = got_error_fmt(GOT_ERR_REF_BUSY,
1585 			    "%s has been modified by someone else "
1586 			    "while transaction was in progress",
1587 			    got_ref_get_name(ref));
1588 			goto done;
1589 		}
1590 
1591 		err = got_ref_change_ref(ref, &new_id);
1592 		if (err)
1593 			goto done;
1594 
1595 		err = got_ref_write(ref, repo);
1596 		if (err)
1597 			goto done;
1598 
1599 		free(id);
1600 		id = NULL;
1601 	}
1602 done:
1603 	if (err) {
1604 		if (err->code == GOT_ERR_LOCKFILE_TIMEOUT) {
1605 			err = got_error_fmt(GOT_ERR_LOCKFILE_TIMEOUT,
1606 			    "could not acquire exclusive file lock for %s",
1607 			    refname);
1608 		}
1609 		send_ref_update_ng(client, &iref, refname, err->msg);
1610 	} else
1611 		send_ref_update_ok(client, &iref, refname);
1612 
1613 	if (client->nref_updates > 0) {
1614 		client->nref_updates--;
1615 		if (client->nref_updates == 0)
1616 			send_refs_updated(client);
1617 
1618 	}
1619 	if (locked) {
1620 		const struct got_error *unlock_err;
1621 		unlock_err = got_ref_unlock(ref);
1622 		if (unlock_err && err == NULL)
1623 			err = unlock_err;
1624 	}
1625 	if (ref)
1626 		got_ref_close(ref);
1627 	if (obj)
1628 		got_object_close(obj);
1629 	if (repo)
1630 		got_repo_close(repo);
1631 	free(refname);
1632 	free(id);
1633 	return err;
1634 }
1635 
1636 static void
1637 gotd_dispatch(int fd, short event, void *arg)
1638 {
1639 	struct gotd_imsgev *iev = arg;
1640 	struct imsgbuf *ibuf = &iev->ibuf;
1641 	struct gotd_child_proc *proc = NULL;
1642 	ssize_t n;
1643 	int shut = 0;
1644 	struct imsg imsg;
1645 
1646 	if (event & EV_READ) {
1647 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1648 			fatal("imsg_read error");
1649 		if (n == 0) {
1650 			/* Connection closed. */
1651 			shut = 1;
1652 			goto done;
1653 		}
1654 	}
1655 
1656 	if (event & EV_WRITE) {
1657 		n = msgbuf_write(&ibuf->w);
1658 		if (n == -1 && errno != EAGAIN)
1659 			fatal("msgbuf_write");
1660 		if (n == 0) {
1661 			/* Connection closed. */
1662 			shut = 1;
1663 			goto done;
1664 		}
1665 	}
1666 
1667 	proc = find_proc_by_fd(fd);
1668 	if (proc == NULL)
1669 		fatalx("cannot find child process for fd %d", fd);
1670 
1671 	for (;;) {
1672 		const struct got_error *err = NULL;
1673 		struct gotd_client *client = NULL;
1674 		uint32_t client_id = 0;
1675 		int do_disconnect = 0;
1676 		int do_ref_updates = 0, do_ref_update = 0;
1677 		int do_packfile_install = 0;
1678 
1679 		if ((n = imsg_get(ibuf, &imsg)) == -1)
1680 			fatal("%s: imsg_get error", __func__);
1681 		if (n == 0)	/* No more messages. */
1682 			break;
1683 
1684 		switch (imsg.hdr.type) {
1685 		case GOTD_IMSG_ERROR:
1686 			do_disconnect = 1;
1687 			err = gotd_imsg_recv_error(&client_id, &imsg);
1688 			break;
1689 		case GOTD_IMSG_PACKFILE_DONE:
1690 			do_disconnect = 1;
1691 			err = recv_packfile_done(&client_id, &imsg);
1692 			break;
1693 		case GOTD_IMSG_PACKFILE_INSTALL:
1694 			err = recv_packfile_install(&client_id, &imsg);
1695 			if (err == NULL)
1696 				do_packfile_install = 1;
1697 			break;
1698 		case GOTD_IMSG_REF_UPDATES_START:
1699 			err = recv_ref_updates_start(&client_id, &imsg);
1700 			if (err == NULL)
1701 				do_ref_updates = 1;
1702 			break;
1703 		case GOTD_IMSG_REF_UPDATE:
1704 			err = recv_ref_update(&client_id, &imsg);
1705 			if (err == NULL)
1706 				do_ref_update = 1;
1707 			break;
1708 		default:
1709 			log_debug("unexpected imsg %d", imsg.hdr.type);
1710 			break;
1711 		}
1712 
1713 		client = find_client(client_id);
1714 		if (client == NULL) {
1715 			log_warnx("%s: client not found", __func__);
1716 			imsg_free(&imsg);
1717 			continue;
1718 		}
1719 
1720 		if (!verify_imsg_src(client, proc, &imsg)) {
1721 			log_debug("dropping imsg type %d from PID %d",
1722 			    imsg.hdr.type, proc->pid);
1723 			imsg_free(&imsg);
1724 			continue;
1725 		}
1726 		if (err)
1727 			log_warnx("uid %d: %s", client->euid, err->msg);
1728 
1729 		if (do_disconnect) {
1730 			if (err)
1731 				disconnect_on_error(client, err);
1732 			else
1733 				disconnect(client);
1734 		} else if (do_packfile_install)
1735 			err = install_pack(client, proc->chroot_path, &imsg);
1736 		else if (do_ref_updates)
1737 			err = begin_ref_updates(client, &imsg);
1738 		else if (do_ref_update)
1739 			err = update_ref(client, proc->chroot_path, &imsg);
1740 
1741 		if (err)
1742 			log_warnx("uid %d: %s", client->euid, err->msg);
1743 		imsg_free(&imsg);
1744 	}
1745 done:
1746 	if (!shut) {
1747 		gotd_imsg_event_add(iev);
1748 	} else {
1749 		/* This pipe is dead. Remove its event handler */
1750 		event_del(&iev->ev);
1751 		event_loopexit(NULL);
1752 	}
1753 }
1754 
1755 static pid_t
1756 start_child(enum gotd_procid proc_id, const char *chroot_path,
1757     char *argv0, int fd, int daemonize, int verbosity)
1758 {
1759 	char	*argv[9];
1760 	int	 argc = 0;
1761 	pid_t	 pid;
1762 
1763 	switch (pid = fork()) {
1764 	case -1:
1765 		fatal("cannot fork");
1766 	case 0:
1767 		break;
1768 	default:
1769 		close(fd);
1770 		return pid;
1771 	}
1772 
1773 	if (fd != GOTD_SOCK_FILENO) {
1774 		if (dup2(fd, GOTD_SOCK_FILENO) == -1)
1775 			fatal("cannot setup imsg fd");
1776 	} else if (fcntl(fd, F_SETFD, 0) == -1)
1777 		fatal("cannot setup imsg fd");
1778 
1779 	argv[argc++] = argv0;
1780 	switch (proc_id) {
1781 	case PROC_REPO_READ:
1782 		argv[argc++] = (char *)"-R";
1783 		break;
1784 	case PROC_REPO_WRITE:
1785 		argv[argc++] = (char *)"-W";
1786 		break;
1787 	default:
1788 		fatalx("invalid process id %d", proc_id);
1789 	}
1790 
1791 	argv[argc++] = (char *)"-P";
1792 	argv[argc++] = (char *)chroot_path;
1793 
1794 	if (!daemonize)
1795 		argv[argc++] = (char *)"-d";
1796 	if (verbosity > 0)
1797 		argv[argc++] = (char *)"-v";
1798 	if (verbosity > 1)
1799 		argv[argc++] = (char *)"-v";
1800 	argv[argc++] = NULL;
1801 
1802 	execvp(argv0, argv);
1803 	fatal("execvp");
1804 }
1805 
1806 static void
1807 start_repo_children(struct gotd *gotd, char *argv0, int daemonize,
1808     int verbosity)
1809 {
1810 	struct gotd_repo *repo = NULL;
1811 	struct gotd_child_proc *proc;
1812 	int i;
1813 
1814 	/*
1815 	 * XXX For now, use one reader and one writer per repository.
1816 	 * This should be changed to N readers + M writers.
1817 	 */
1818 	gotd->nprocs = gotd->nrepos * 2;
1819 	gotd->procs = calloc(gotd->nprocs, sizeof(*gotd->procs));
1820 	if (gotd->procs == NULL)
1821 		fatal("calloc");
1822 	for (i = 0; i < gotd->nprocs; i++) {
1823 		if (repo == NULL)
1824 			repo = TAILQ_FIRST(&gotd->repos);
1825 		proc = &gotd->procs[i];
1826 		if (i < gotd->nrepos)
1827 			proc->type = PROC_REPO_READ;
1828 		else
1829 			proc->type = PROC_REPO_WRITE;
1830 		if (strlcpy(proc->repo_name, repo->name,
1831 		    sizeof(proc->repo_name)) >= sizeof(proc->repo_name))
1832 			fatalx("repository name too long: %s", repo->name);
1833 		log_debug("adding repository %s", repo->name);
1834 		if (realpath(repo->path, proc->chroot_path) == NULL)
1835 			fatal("%s", repo->path);
1836 		if (socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK,
1837 		    PF_UNSPEC, proc->pipe) == -1)
1838 			fatal("socketpair");
1839 		proc->pid = start_child(proc->type, proc->chroot_path, argv0,
1840 		    proc->pipe[1], daemonize, verbosity);
1841 		imsg_init(&proc->iev.ibuf, proc->pipe[0]);
1842 		log_debug("proc %s %s is on fd %d",
1843 		    gotd_proc_names[proc->type], proc->chroot_path,
1844 		    proc->pipe[0]);
1845 		proc->iev.handler = gotd_dispatch;
1846 		proc->iev.events = EV_READ;
1847 		proc->iev.handler_arg = NULL;
1848 		event_set(&proc->iev.ev, proc->iev.ibuf.fd, EV_READ,
1849 		    gotd_dispatch, &proc->iev);
1850 
1851 		repo = TAILQ_NEXT(repo, entry);
1852 	}
1853 }
1854 
1855 static void
1856 apply_unveil(void)
1857 {
1858 	struct gotd_repo *repo;
1859 
1860 	TAILQ_FOREACH(repo, &gotd.repos, entry) {
1861 		if (unveil(repo->path, "rwc") == -1)
1862 			fatal("unveil %s", repo->path);
1863 	}
1864 
1865 	if (unveil(GOT_TMPDIR_STR, "rwc") == -1)
1866 		fatal("unveil %s", GOT_TMPDIR_STR);
1867 
1868 	if (unveil(NULL, NULL) == -1)
1869 		fatal("unveil");
1870 }
1871 
1872 int
1873 main(int argc, char **argv)
1874 {
1875 	const struct got_error *error = NULL;
1876 	int ch, fd = -1, daemonize = 1, verbosity = 0, noaction = 0;
1877 	const char *confpath = GOTD_CONF_PATH;
1878 	char *argv0 = argv[0];
1879 	char title[2048];
1880 	gid_t groups[NGROUPS_MAX + 1];
1881 	int ngroups = NGROUPS_MAX + 1;
1882 	struct passwd *pw = NULL;
1883 	struct group *gr = NULL;
1884 	char *repo_path = NULL;
1885 	enum gotd_procid proc_id = PROC_GOTD;
1886 	struct event evsigint, evsigterm, evsighup, evsigusr1;
1887 	int *pack_fds = NULL, *temp_fds = NULL;
1888 
1889 	log_init(1, LOG_DAEMON); /* Log to stderr until daemonized. */
1890 
1891 	while ((ch = getopt(argc, argv, "df:nP:RvW")) != -1) {
1892 		switch (ch) {
1893 		case 'd':
1894 			daemonize = 0;
1895 			break;
1896 		case 'f':
1897 			confpath = optarg;
1898 			break;
1899 		case 'n':
1900 			noaction = 1;
1901 			break;
1902 		case 'P':
1903 			repo_path = realpath(optarg, NULL);
1904 			if (repo_path == NULL)
1905 				fatal("realpath '%s'", optarg);
1906 			break;
1907 		case 'R':
1908 			proc_id = PROC_REPO_READ;
1909 			break;
1910 		case 'v':
1911 			if (verbosity < 3)
1912 				verbosity++;
1913 			break;
1914 		case 'W':
1915 			proc_id = PROC_REPO_WRITE;
1916 			break;
1917 		default:
1918 			usage();
1919 		}
1920 	}
1921 
1922 	argc -= optind;
1923 	argv += optind;
1924 
1925 	if (argc != 0)
1926 		usage();
1927 
1928 	if (geteuid())
1929 		fatalx("need root privileges");
1930 
1931 	log_init(daemonize ? 0 : 1, LOG_DAEMON);
1932 	log_setverbose(verbosity);
1933 
1934 	if (parse_config(confpath, proc_id, &gotd) != 0)
1935 		return 1;
1936 
1937 	if (proc_id == PROC_GOTD &&
1938 	    (gotd.nrepos == 0 || TAILQ_EMPTY(&gotd.repos)))
1939 		fatalx("no repository defined in configuration file");
1940 
1941 	pw = getpwnam(gotd.user_name);
1942 	if (pw == NULL)
1943 		fatal("getpwuid: user %s not found", gotd.user_name);
1944 
1945 	if (pw->pw_uid == 0) {
1946 		fatalx("cannot run %s as %s: the user running %s "
1947 		    "must not be the superuser",
1948 		    getprogname(), pw->pw_name, getprogname());
1949 	}
1950 
1951 	if (getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups) == -1)
1952 		log_warnx("group membership list truncated");
1953 
1954 	gr = match_group(groups, ngroups, gotd.unix_group_name);
1955 	if (gr == NULL) {
1956 		fatalx("cannot start %s: the user running %s "
1957 		    "must be a secondary member of group %s",
1958 		    getprogname(), getprogname(), gotd.unix_group_name);
1959 	}
1960 	if (gr->gr_gid == pw->pw_gid) {
1961 		fatalx("cannot start %s: the user running %s "
1962 		    "must be a secondary member of group %s, but "
1963 		    "%s is the user's primary group",
1964 		    getprogname(), getprogname(), gotd.unix_group_name,
1965 		    gotd.unix_group_name);
1966 	}
1967 
1968 	if (proc_id == PROC_GOTD &&
1969 	    !got_path_is_absolute(gotd.unix_socket_path))
1970 		fatalx("bad unix socket path \"%s\": must be an absolute path",
1971 		    gotd.unix_socket_path);
1972 
1973 	if (noaction)
1974 		return 0;
1975 
1976 	if (proc_id == PROC_GOTD && verbosity) {
1977 		log_info("socket: %s", gotd.unix_socket_path);
1978 		log_info("user: %s", pw->pw_name);
1979 		log_info("secondary group: %s", gr->gr_name);
1980 
1981 		fd = unix_socket_listen(gotd.unix_socket_path, pw->pw_uid,
1982 		    gr->gr_gid);
1983 		if (fd == -1) {
1984 			fatal("cannot listen on unix socket %s",
1985 			    gotd.unix_socket_path);
1986 		}
1987 	}
1988 
1989 	if (proc_id == PROC_GOTD) {
1990 		gotd.pid = getpid();
1991 		snprintf(title, sizeof(title), "%s", gotd_proc_names[proc_id]);
1992 		start_repo_children(&gotd, argv0, daemonize, verbosity);
1993 		arc4random_buf(&clients_hash_key, sizeof(clients_hash_key));
1994 		if (daemonize && daemon(0, 0) == -1)
1995 			fatal("daemon");
1996 	} else if (proc_id == PROC_REPO_READ || proc_id == PROC_REPO_WRITE) {
1997 		error = got_repo_pack_fds_open(&pack_fds);
1998 		if (error != NULL)
1999 			fatalx("cannot open pack tempfiles: %s", error->msg);
2000 		error = got_repo_temp_fds_open(&temp_fds);
2001 		if (error != NULL)
2002 			fatalx("cannot open pack tempfiles: %s", error->msg);
2003 		if (repo_path == NULL)
2004 			fatalx("repository path not specified");
2005 		snprintf(title, sizeof(title), "%s %s",
2006 		    gotd_proc_names[proc_id], repo_path);
2007 		if (chroot(repo_path) == -1)
2008 			fatal("chroot");
2009 		if (chdir("/") == -1)
2010 			fatal("chdir(\"/\")");
2011 		if (daemonize && daemon(1, 0) == -1)
2012 			fatal("daemon");
2013 	} else
2014 		fatal("invalid process id %d", proc_id);
2015 
2016 	setproctitle("%s", title);
2017 	log_procinit(title);
2018 
2019 	/* Drop root privileges. */
2020 	if (setgid(pw->pw_gid) == -1)
2021 		fatal("setgid %d failed", pw->pw_gid);
2022 	if (setuid(pw->pw_uid) == -1)
2023 		fatal("setuid %d failed", pw->pw_uid);
2024 
2025 	event_init();
2026 
2027 	switch (proc_id) {
2028 	case PROC_GOTD:
2029 #ifndef PROFILE
2030 		if (pledge("stdio rpath wpath cpath proc getpw sendfd recvfd "
2031 		    "fattr flock unix unveil", NULL) == -1)
2032 			err(1, "pledge");
2033 #endif
2034 		break;
2035 	case PROC_REPO_READ:
2036 #ifndef PROFILE
2037 		if (pledge("stdio rpath recvfd", NULL) == -1)
2038 			err(1, "pledge");
2039 #endif
2040 		repo_read_main(title, pack_fds, temp_fds);
2041 		/* NOTREACHED */
2042 		exit(0);
2043 	case PROC_REPO_WRITE:
2044 #ifndef PROFILE
2045 		if (pledge("stdio rpath sendfd recvfd", NULL) == -1)
2046 			err(1, "pledge");
2047 #endif
2048 		repo_write_main(title, pack_fds, temp_fds);
2049 		/* NOTREACHED */
2050 		exit(0);
2051 	default:
2052 		fatal("invalid process id %d", proc_id);
2053 	}
2054 
2055 	if (proc_id != PROC_GOTD)
2056 		fatal("invalid process id %d", proc_id);
2057 
2058 	apply_unveil();
2059 
2060 	signal_set(&evsigint, SIGINT, gotd_sighdlr, NULL);
2061 	signal_set(&evsigterm, SIGTERM, gotd_sighdlr, NULL);
2062 	signal_set(&evsighup, SIGHUP, gotd_sighdlr, NULL);
2063 	signal_set(&evsigusr1, SIGUSR1, gotd_sighdlr, NULL);
2064 	signal(SIGPIPE, SIG_IGN);
2065 
2066 	signal_add(&evsigint, NULL);
2067 	signal_add(&evsigterm, NULL);
2068 	signal_add(&evsighup, NULL);
2069 	signal_add(&evsigusr1, NULL);
2070 
2071 	event_set(&gotd.ev, fd, EV_READ | EV_PERSIST, gotd_accept, NULL);
2072 	if (event_add(&gotd.ev, NULL))
2073 		fatalx("event add");
2074 	evtimer_set(&gotd.pause, gotd_accept_paused, NULL);
2075 
2076 	event_dispatch();
2077 
2078 	if (fd != -1)
2079 		close(fd);
2080 	if (pack_fds)
2081 		got_repo_pack_fds_close(pack_fds);
2082 	free(repo_path);
2083 	return 0;
2084 }