Game of Trees Repos

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Date:: Sun Jun 25 17:34:21 2023 UTC
Message:: gotd: wait asynchronously for children termination Instead of the current kill() + waitpid(WNOHANG), manage the subprocesses in a separate queue and handle SIGCHLD. A timer is installed to ensure that misbehaving subprocesses are still killed. Fixes the current "child PID 0 terminated" logs due to races with waitpid(). Issue initially reported by Josiah Frentsos. ok + tweaks stsp@
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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/time.h>
19 #include <sys/types.h>
20 #include <sys/stat.h>
21 #include <sys/socket.h>
22 #include <sys/un.h>
23 #include <sys/wait.h>
24 
25 #include <fcntl.h>
26 #include <err.h>
27 #include <errno.h>
28 #include <event.h>
29 #include <limits.h>
30 #include <pwd.h>
31 #include <imsg.h>
32 #include <signal.h>
33 #include <siphash.h>
34 #include <stdarg.h>
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <string.h>
38 #include <syslog.h>
39 #include <unistd.h>
40 
41 #include "got_error.h"
42 #include "got_opentemp.h"
43 #include "got_path.h"
44 #include "got_repository.h"
45 #include "got_object.h"
46 #include "got_reference.h"
47 
48 #include "got_lib_delta.h"
49 #include "got_lib_object.h"
50 #include "got_lib_object_cache.h"
51 #include "got_lib_hash.h"
52 #include "got_lib_gitproto.h"
53 #include "got_lib_pack.h"
54 #include "got_lib_repository.h"
55 
56 #include "gotd.h"
57 #include "log.h"
58 #include "listen.h"
59 #include "auth.h"
60 #include "session.h"
61 #include "repo_read.h"
62 #include "repo_write.h"
63 
64 #ifndef nitems
65 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
66 #endif
67 
68 enum gotd_client_state {
69 	GOTD_CLIENT_STATE_NEW,
70 	GOTD_CLIENT_STATE_ACCESS_GRANTED,
71 };
72 
73 struct gotd_child_proc {
74 	pid_t				 pid;
75 	enum gotd_procid		 type;
76 	char				 repo_name[NAME_MAX];
77 	char				 repo_path[PATH_MAX];
78 	int				 pipe[2];
79 	struct gotd_imsgev		 iev;
80 	struct event			 tmo;
81 
82 	TAILQ_ENTRY(gotd_child_proc)	 entry;
83 };
84 TAILQ_HEAD(gotd_procs, gotd_child_proc) procs;
85 
86 struct gotd_client {
87 	STAILQ_ENTRY(gotd_client)	 entry;
88 	enum gotd_client_state		 state;
89 	uint32_t			 id;
90 	int				 fd;
91 	struct gotd_imsgev		 iev;
92 	struct event			 tmo;
93 	uid_t				 euid;
94 	gid_t				 egid;
95 	struct gotd_child_proc		*repo;
96 	struct gotd_child_proc		*auth;
97 	struct gotd_child_proc		*session;
98 	int				 required_auth;
99 };
100 STAILQ_HEAD(gotd_clients, gotd_client);
101 
102 static struct gotd_clients gotd_clients[GOTD_CLIENT_TABLE_SIZE];
103 static SIPHASH_KEY clients_hash_key;
104 volatile int client_cnt;
105 static struct timeval auth_timeout = { 5, 0 };
106 static struct gotd gotd;
107 
108 void gotd_sighdlr(int sig, short event, void *arg);
109 static void gotd_shutdown(void);
110 static const struct got_error *start_session_child(struct gotd_client *,
111     struct gotd_repo *, char *, const char *, int, int);
112 static const struct got_error *start_repo_child(struct gotd_client *,
113     enum gotd_procid, struct gotd_repo *, char *, const char *, int, int);
114 static const struct got_error *start_auth_child(struct gotd_client *, int,
115     struct gotd_repo *, char *, const char *, int, int);
116 static void kill_proc(struct gotd_child_proc *, int);
117 static void disconnect(struct gotd_client *);
118 
119 __dead static void
120 usage(void)
121 {
122 	fprintf(stderr, "usage: %s [-dnv] [-f config-file]\n", getprogname());
123 	exit(1);
124 }
125 
126 static int
127 unix_socket_listen(const char *unix_socket_path, uid_t uid, gid_t gid)
128 {
129 	struct sockaddr_un sun;
130 	int fd = -1;
131 	mode_t old_umask, mode;
132 
133 	fd = socket(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK| SOCK_CLOEXEC, 0);
134 	if (fd == -1) {
135 		log_warn("socket");
136 		return -1;
137 	}
138 
139 	sun.sun_family = AF_UNIX;
140 	if (strlcpy(sun.sun_path, unix_socket_path,
141 	    sizeof(sun.sun_path)) >= sizeof(sun.sun_path)) {
142 		log_warnx("%s: name too long", unix_socket_path);
143 		close(fd);
144 		return -1;
145 	}
146 
147 	if (unlink(unix_socket_path) == -1) {
148 		if (errno != ENOENT) {
149 			log_warn("unlink %s", unix_socket_path);
150 			close(fd);
151 			return -1;
152 		}
153 	}
154 
155 	old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);
156 	mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH;
157 
158 	if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
159 		log_warn("bind: %s", unix_socket_path);
160 		close(fd);
161 		umask(old_umask);
162 		return -1;
163 	}
164 
165 	umask(old_umask);
166 
167 	if (chmod(unix_socket_path, mode) == -1) {
168 		log_warn("chmod %o %s", mode, unix_socket_path);
169 		close(fd);
170 		unlink(unix_socket_path);
171 		return -1;
172 	}
173 
174 	if (chown(unix_socket_path, uid, gid) == -1) {
175 		log_warn("chown %s uid=%d gid=%d", unix_socket_path, uid, gid);
176 		close(fd);
177 		unlink(unix_socket_path);
178 		return -1;
179 	}
180 
181 	if (listen(fd, GOTD_UNIX_SOCKET_BACKLOG) == -1) {
182 		log_warn("listen");
183 		close(fd);
184 		unlink(unix_socket_path);
185 		return -1;
186 	}
187 
188 	return fd;
189 }
190 
191 static uint64_t
192 client_hash(uint32_t client_id)
193 {
194 	return SipHash24(&clients_hash_key, &client_id, sizeof(client_id));
195 }
196 
197 static void
198 add_client(struct gotd_client *client)
199 {
200 	uint64_t slot = client_hash(client->id) % nitems(gotd_clients);
201 	STAILQ_INSERT_HEAD(&gotd_clients[slot], client, entry);
202 	client_cnt++;
203 }
204 
205 static struct gotd_client *
206 find_client(uint32_t client_id)
207 {
208 	uint64_t slot;
209 	struct gotd_client *c;
210 
211 	slot = client_hash(client_id) % nitems(gotd_clients);
212 	STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
213 		if (c->id == client_id)
214 			return c;
215 	}
216 
217 	return NULL;
218 }
219 
220 static struct gotd_client *
221 find_client_by_proc_fd(int fd)
222 {
223 	uint64_t slot;
224 
225 	for (slot = 0; slot < nitems(gotd_clients); slot++) {
226 		struct gotd_client *c;
227 
228 		STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
229 			if (c->repo && c->repo->iev.ibuf.fd == fd)
230 				return c;
231 			if (c->auth && c->auth->iev.ibuf.fd == fd)
232 				return c;
233 			if (c->session && c->session->iev.ibuf.fd == fd)
234 				return c;
235 		}
236 	}
237 
238 	return NULL;
239 }
240 
241 static int
242 client_is_reading(struct gotd_client *client)
243 {
244 	return (client->required_auth &
245 	    (GOTD_AUTH_READ | GOTD_AUTH_WRITE)) == GOTD_AUTH_READ;
246 }
247 
248 static int
249 client_is_writing(struct gotd_client *client)
250 {
251 	return (client->required_auth &
252 	    (GOTD_AUTH_READ | GOTD_AUTH_WRITE)) ==
253 	    (GOTD_AUTH_READ | GOTD_AUTH_WRITE);
254 }
255 
256 static const struct got_error *
257 ensure_client_is_not_writing(struct gotd_client *client)
258 {
259 	if (client_is_writing(client)) {
260 		return got_error_fmt(GOT_ERR_BAD_PACKET,
261 		    "uid %d made a read-request but is writing to "
262 		    "a repository", client->euid);
263 	}
264 
265 	return NULL;
266 }
267 
268 static const struct got_error *
269 ensure_client_is_not_reading(struct gotd_client *client)
270 {
271 	if (client_is_reading(client)) {
272 		return got_error_fmt(GOT_ERR_BAD_PACKET,
273 		    "uid %d made a write-request but is reading from "
274 		    "a repository", client->euid);
275 	}
276 
277 	return NULL;
278 }
279 
280 static void
281 proc_done(struct gotd_child_proc *proc)
282 {
283 	struct gotd_client *client;
284 
285 	TAILQ_REMOVE(&procs, proc, entry);
286 
287 	client = find_client_by_proc_fd(proc->iev.ibuf.fd);
288 	if (client != NULL) {
289 		if (proc == client->repo)
290 			client->repo = NULL;
291 		if (proc == client->auth)
292 			client->auth = NULL;
293 		if (proc == client->session)
294 			client->session = NULL;
295 		disconnect(client);
296 	}
297 
298 	evtimer_del(&proc->tmo);
299 
300 	if (proc->iev.ibuf.fd != -1) {
301 		event_del(&proc->iev.ev);
302 		msgbuf_clear(&proc->iev.ibuf.w);
303 		close(proc->iev.ibuf.fd);
304 	}
305 
306 	free(proc);
307 }
308 
309 static void
310 kill_repo_proc(struct gotd_client *client)
311 {
312 	if (client->repo == NULL)
313 		return;
314 
315 	kill_proc(client->repo, 0);
316 	client->repo = NULL;
317 }
318 
319 static void
320 kill_auth_proc(struct gotd_client *client)
321 {
322 	if (client->auth == NULL)
323 		return;
324 
325 	kill_proc(client->auth, 0);
326 	client->auth = NULL;
327 }
328 
329 static void
330 kill_session_proc(struct gotd_client *client)
331 {
332 	if (client->session == NULL)
333 		return;
334 
335 	kill_proc(client->session, 0);
336 	client->session = NULL;
337 }
338 
339 static void
340 disconnect(struct gotd_client *client)
341 {
342 	struct gotd_imsg_disconnect idisconnect;
343 	struct gotd_child_proc *listen_proc = gotd.listen_proc;
344 	uint64_t slot;
345 
346 	log_debug("uid %d: disconnecting", client->euid);
347 
348 	kill_auth_proc(client);
349 	kill_session_proc(client);
350 	kill_repo_proc(client);
351 
352 	idisconnect.client_id = client->id;
353 	if (gotd_imsg_compose_event(&listen_proc->iev,
354 	    GOTD_IMSG_DISCONNECT, PROC_GOTD, -1,
355 	    &idisconnect, sizeof(idisconnect)) == -1)
356 		log_warn("imsg compose DISCONNECT");
357 
358 	slot = client_hash(client->id) % nitems(gotd_clients);
359 	STAILQ_REMOVE(&gotd_clients[slot], client, gotd_client, entry);
360 	imsg_clear(&client->iev.ibuf);
361 	event_del(&client->iev.ev);
362 	evtimer_del(&client->tmo);
363 	if (client->fd != -1)
364 		close(client->fd);
365 	else if (client->iev.ibuf.fd != -1)
366 		close(client->iev.ibuf.fd);
367 	free(client);
368 	client_cnt--;
369 }
370 
371 static void
372 disconnect_on_error(struct gotd_client *client, const struct got_error *err)
373 {
374 	struct imsgbuf ibuf;
375 
376 	log_warnx("uid %d: %s", client->euid, err->msg);
377 	if (err->code != GOT_ERR_EOF && client->fd != -1) {
378 		imsg_init(&ibuf, client->fd);
379 		gotd_imsg_send_error(&ibuf, 0, PROC_GOTD, err);
380 		imsg_clear(&ibuf);
381 	}
382 	disconnect(client);
383 }
384 
385 static const struct got_error *
386 send_repo_info(struct gotd_imsgev *iev, struct gotd_repo *repo)
387 {
388 	const struct got_error *err = NULL;
389 	struct gotd_imsg_info_repo irepo;
390 
391 	memset(&irepo, 0, sizeof(irepo));
392 
393 	if (strlcpy(irepo.repo_name, repo->name, sizeof(irepo.repo_name))
394 	    >= sizeof(irepo.repo_name))
395 		return got_error_msg(GOT_ERR_NO_SPACE, "repo name too long");
396 	if (strlcpy(irepo.repo_path, repo->path, sizeof(irepo.repo_path))
397 	    >= sizeof(irepo.repo_path))
398 		return got_error_msg(GOT_ERR_NO_SPACE, "repo path too long");
399 
400 	if (gotd_imsg_compose_event(iev, GOTD_IMSG_INFO_REPO, PROC_GOTD, -1,
401 	    &irepo, sizeof(irepo)) == -1) {
402 		err = got_error_from_errno("imsg compose INFO_REPO");
403 		if (err)
404 			return err;
405 	}
406 
407 	return NULL;
408 }
409 
410 static const struct got_error *
411 send_client_info(struct gotd_imsgev *iev, struct gotd_client *client)
412 {
413 	const struct got_error *err = NULL;
414 	struct gotd_imsg_info_client iclient;
415 	struct gotd_child_proc *proc;
416 
417 	memset(&iclient, 0, sizeof(iclient));
418 	iclient.euid = client->euid;
419 	iclient.egid = client->egid;
420 
421 	proc = client->repo;
422 	if (proc) {
423 		if (strlcpy(iclient.repo_name, proc->repo_path,
424 		    sizeof(iclient.repo_name)) >= sizeof(iclient.repo_name)) {
425 			return got_error_msg(GOT_ERR_NO_SPACE,
426 			    "repo name too long");
427 		}
428 		if (client_is_writing(client))
429 			iclient.is_writing = 1;
430 
431 		iclient.repo_child_pid = proc->pid;
432 	}
433 
434 	if (client->session)
435 		iclient.session_child_pid = client->session->pid;
436 
437 	if (gotd_imsg_compose_event(iev, GOTD_IMSG_INFO_CLIENT, PROC_GOTD, -1,
438 	    &iclient, sizeof(iclient)) == -1) {
439 		err = got_error_from_errno("imsg compose INFO_CLIENT");
440 		if (err)
441 			return err;
442 	}
443 
444 	return NULL;
445 }
446 
447 static const struct got_error *
448 send_info(struct gotd_client *client)
449 {
450 	const struct got_error *err = NULL;
451 	struct gotd_imsg_info info;
452 	uint64_t slot;
453 	struct gotd_repo *repo;
454 
455 	if (client->euid != 0)
456 		return got_error_set_errno(EPERM, "info");
457 
458 	info.pid = gotd.pid;
459 	info.verbosity = gotd.verbosity;
460 	info.nrepos = gotd.nrepos;
461 	info.nclients = client_cnt - 1;
462 
463 	if (gotd_imsg_compose_event(&client->iev, GOTD_IMSG_INFO, PROC_GOTD, -1,
464 	    &info, sizeof(info)) == -1) {
465 		err = got_error_from_errno("imsg compose INFO");
466 		if (err)
467 			return err;
468 	}
469 
470 	TAILQ_FOREACH(repo, &gotd.repos, entry) {
471 		err = send_repo_info(&client->iev, repo);
472 		if (err)
473 			return err;
474 	}
475 
476 	for (slot = 0; slot < nitems(gotd_clients); slot++) {
477 		struct gotd_client *c;
478 		STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
479 			if (c->id == client->id)
480 				continue;
481 			err = send_client_info(&client->iev, c);
482 			if (err)
483 				return err;
484 		}
485 	}
486 
487 	return NULL;
488 }
489 
490 static const struct got_error *
491 stop_gotd(struct gotd_client *client)
492 {
493 
494 	if (client->euid != 0)
495 		return got_error_set_errno(EPERM, "stop");
496 
497 	gotd_shutdown();
498 	/* NOTREACHED */
499 	return NULL;
500 }
501 
502 static const struct got_error *
503 start_client_authentication(struct gotd_client *client, struct imsg *imsg)
504 {
505 	const struct got_error *err;
506 	struct gotd_imsg_list_refs ireq;
507 	struct gotd_repo *repo = NULL;
508 	size_t datalen;
509 
510 	log_debug("list-refs request from uid %d", client->euid);
511 
512 	if (client->state != GOTD_CLIENT_STATE_NEW)
513 		return got_error_msg(GOT_ERR_BAD_REQUEST,
514 		    "unexpected list-refs request received");
515 
516 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
517 	if (datalen != sizeof(ireq))
518 		return got_error(GOT_ERR_PRIVSEP_LEN);
519 
520 	memcpy(&ireq, imsg->data, datalen);
521 
522 	if (ireq.client_is_reading) {
523 		err = ensure_client_is_not_writing(client);
524 		if (err)
525 			return err;
526 		repo = gotd_find_repo_by_name(ireq.repo_name, &gotd);
527 		if (repo == NULL)
528 			return got_error(GOT_ERR_NOT_GIT_REPO);
529 		err = start_auth_child(client, GOTD_AUTH_READ, repo,
530 		    gotd.argv0, gotd.confpath, gotd.daemonize,
531 		    gotd.verbosity);
532 		if (err)
533 			return err;
534 	} else {
535 		err = ensure_client_is_not_reading(client);
536 		if (err)
537 			return err;
538 		repo = gotd_find_repo_by_name(ireq.repo_name, &gotd);
539 		if (repo == NULL)
540 			return got_error(GOT_ERR_NOT_GIT_REPO);
541 		err = start_auth_child(client,
542 		    GOTD_AUTH_READ | GOTD_AUTH_WRITE,
543 		    repo, gotd.argv0, gotd.confpath, gotd.daemonize,
544 		    gotd.verbosity);
545 		if (err)
546 			return err;
547 	}
548 
549 	evtimer_add(&client->tmo, &auth_timeout);
550 
551 	/* Flow continues upon authentication successs/failure or timeout. */
552 	return NULL;
553 }
554 
555 static void
556 gotd_request(int fd, short events, void *arg)
557 {
558 	struct gotd_imsgev *iev = arg;
559 	struct imsgbuf *ibuf = &iev->ibuf;
560 	struct gotd_client *client = iev->handler_arg;
561 	const struct got_error *err = NULL;
562 	struct imsg imsg;
563 	ssize_t n;
564 
565 	if (events & EV_WRITE) {
566 		while (ibuf->w.queued) {
567 			n = msgbuf_write(&ibuf->w);
568 			if (n == -1 && errno == EPIPE) {
569 				/*
570 				 * The client has closed its socket.
571 				 * This can happen when Git clients are
572 				 * done sending pack file data.
573 				 */
574 				msgbuf_clear(&ibuf->w);
575 				continue;
576 			} else if (n == -1 && errno != EAGAIN) {
577 				err = got_error_from_errno("imsg_flush");
578 				disconnect_on_error(client, err);
579 				return;
580 			}
581 			if (n == 0) {
582 				/* Connection closed. */
583 				err = got_error(GOT_ERR_EOF);
584 				disconnect_on_error(client, err);
585 				return;
586 			}
587 		}
588 
589 		/* Disconnect gotctl(8) now that messages have been sent. */
590 		if (!client_is_reading(client) && !client_is_writing(client)) {
591 			disconnect(client);
592 			return;
593 		}
594 	}
595 
596 	if ((events & EV_READ) == 0)
597 		return;
598 
599 	memset(&imsg, 0, sizeof(imsg));
600 
601 	while (err == NULL) {
602 		err = gotd_imsg_recv(&imsg, ibuf, 0);
603 		if (err) {
604 			if (err->code == GOT_ERR_PRIVSEP_READ)
605 				err = NULL;
606 			break;
607 		}
608 
609 		evtimer_del(&client->tmo);
610 
611 		switch (imsg.hdr.type) {
612 		case GOTD_IMSG_INFO:
613 			err = send_info(client);
614 			break;
615 		case GOTD_IMSG_STOP:
616 			err = stop_gotd(client);
617 			break;
618 		case GOTD_IMSG_LIST_REFS:
619 			err = start_client_authentication(client, &imsg);
620 			break;
621 		default:
622 			log_debug("unexpected imsg %d", imsg.hdr.type);
623 			err = got_error(GOT_ERR_PRIVSEP_MSG);
624 			break;
625 		}
626 
627 		imsg_free(&imsg);
628 	}
629 
630 	if (err) {
631 		disconnect_on_error(client, err);
632 	} else {
633 		gotd_imsg_event_add(&client->iev);
634 	}
635 }
636 
637 static void
638 gotd_auth_timeout(int fd, short events, void *arg)
639 {
640 	struct gotd_client *client = arg;
641 
642 	log_debug("disconnecting uid %d due to authentication timeout",
643 	    client->euid);
644 	disconnect(client);
645 }
646 
647 static const struct got_error *
648 recv_connect(uint32_t *client_id, struct imsg *imsg)
649 {
650 	const struct got_error *err = NULL;
651 	struct gotd_imsg_connect iconnect;
652 	size_t datalen;
653 	int s = -1;
654 	struct gotd_client *client = NULL;
655 
656 	*client_id = 0;
657 
658 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
659 	if (datalen != sizeof(iconnect))
660 		return got_error(GOT_ERR_PRIVSEP_LEN);
661 	memcpy(&iconnect, imsg->data, sizeof(iconnect));
662 
663 	s = imsg->fd;
664 	if (s == -1) {
665 		err = got_error(GOT_ERR_PRIVSEP_NO_FD);
666 		goto done;
667 	}
668 
669 	if (find_client(iconnect.client_id)) {
670 		err = got_error_msg(GOT_ERR_CLIENT_ID, "duplicate client ID");
671 		goto done;
672 	}
673 
674 	client = calloc(1, sizeof(*client));
675 	if (client == NULL) {
676 		err = got_error_from_errno("calloc");
677 		goto done;
678 	}
679 
680 	*client_id = iconnect.client_id;
681 
682 	client->state = GOTD_CLIENT_STATE_NEW;
683 	client->id = iconnect.client_id;
684 	client->fd = s;
685 	s = -1;
686 	/* The auth process will verify UID/GID for us. */
687 	client->euid = iconnect.euid;
688 	client->egid = iconnect.egid;
689 
690 	imsg_init(&client->iev.ibuf, client->fd);
691 	client->iev.handler = gotd_request;
692 	client->iev.events = EV_READ;
693 	client->iev.handler_arg = client;
694 
695 	event_set(&client->iev.ev, client->fd, EV_READ, gotd_request,
696 	    &client->iev);
697 	gotd_imsg_event_add(&client->iev);
698 
699 	evtimer_set(&client->tmo, gotd_auth_timeout, client);
700 
701 	add_client(client);
702 	log_debug("%s: new client uid %d connected on fd %d", __func__,
703 	    client->euid, client->fd);
704 done:
705 	if (err) {
706 		struct gotd_child_proc *listen_proc = gotd.listen_proc;
707 		struct gotd_imsg_disconnect idisconnect;
708 
709 		idisconnect.client_id = client->id;
710 		if (gotd_imsg_compose_event(&listen_proc->iev,
711 		    GOTD_IMSG_DISCONNECT, PROC_GOTD, -1,
712 		    &idisconnect, sizeof(idisconnect)) == -1)
713 			log_warn("imsg compose DISCONNECT");
714 
715 		if (s != -1)
716 			close(s);
717 	}
718 
719 	return err;
720 }
721 
722 static const char *gotd_proc_names[PROC_MAX] = {
723 	"parent",
724 	"listen",
725 	"auth",
726 	"session_read",
727 	"session_write",
728 	"repo_read",
729 	"repo_write"
730 };
731 
732 static void
733 kill_proc(struct gotd_child_proc *proc, int fatal)
734 {
735 	struct timeval tv = { 5, 0 };
736 
737 	log_debug("kill -%d %d", fatal ? SIGKILL : SIGTERM, proc->pid);
738 
739 	if (proc->iev.ibuf.fd != -1) {
740 		event_del(&proc->iev.ev);
741 		msgbuf_clear(&proc->iev.ibuf.w);
742 		close(proc->iev.ibuf.fd);
743 		proc->iev.ibuf.fd = -1;
744 	}
745 
746 	if (!evtimer_pending(&proc->tmo, NULL) && !fatal)
747 		evtimer_add(&proc->tmo, &tv);
748 
749 	if (fatal) {
750 		log_warnx("sending SIGKILL to PID %d", proc->pid);
751 		kill(proc->pid, SIGKILL);
752 	} else
753 		kill(proc->pid, SIGTERM);
754 }
755 
756 static void
757 kill_proc_timeout(int fd, short ev, void *d)
758 {
759 	struct gotd_child_proc *proc = d;
760 
761 	log_warnx("timeout waiting for PID %d to terminate;"
762 	    " retrying with force", proc->pid);
763 	kill_proc(proc, 1);
764 }
765 
766 static void
767 gotd_shutdown(void)
768 {
769 	uint64_t slot;
770 
771 	log_debug("shutting down");
772 	for (slot = 0; slot < nitems(gotd_clients); slot++) {
773 		struct gotd_client *c, *tmp;
774 
775 		STAILQ_FOREACH_SAFE(c, &gotd_clients[slot], entry, tmp)
776 			disconnect(c);
777 	}
778 
779 	kill_proc(gotd.listen_proc, 0);
780 
781 	log_info("terminating");
782 	exit(0);
783 }
784 
785 static struct gotd_child_proc *
786 find_proc_by_pid(pid_t pid)
787 {
788 	struct gotd_child_proc *proc = NULL;
789 
790 	TAILQ_FOREACH(proc, &procs, entry)
791 		if (proc->pid == pid)
792 			break;
793 
794 	return proc;
795 }
796 
797 void
798 gotd_sighdlr(int sig, short event, void *arg)
799 {
800 	struct gotd_child_proc *proc;
801 	pid_t pid;
802 	int status;
803 
804 	/*
805 	 * Normal signal handler rules don't apply because libevent
806 	 * decouples for us.
807 	 */
808 
809 	switch (sig) {
810 	case SIGHUP:
811 		log_info("%s: ignoring SIGHUP", __func__);
812 		break;
813 	case SIGUSR1:
814 		log_info("%s: ignoring SIGUSR1", __func__);
815 		break;
816 	case SIGTERM:
817 	case SIGINT:
818 		gotd_shutdown();
819 		break;
820 	case SIGCHLD:
821 		for (;;) {
822 			pid = waitpid(WAIT_ANY, &status, WNOHANG);
823 			if (pid == -1) {
824 				if (errno == EINTR)
825 					continue;
826 				if (errno == ECHILD)
827 					break;
828 				fatal("waitpid");
829 			}
830 			if (pid == 0)
831 				break;
832 
833 			log_debug("reaped pid %d", pid);
834 			proc = find_proc_by_pid(pid);
835 			if (proc == NULL) {
836 				log_info("caught exit of unknown child %d",
837 				    pid);
838 				continue;
839 			}
840 
841 			if (WIFSIGNALED(status)) {
842 				log_warnx("child PID %d terminated with"
843 				    " signal %d", pid, WTERMSIG(status));
844 			}
845 
846 			proc_done(proc);
847 		}
848 		break;
849 	default:
850 		fatalx("unexpected signal");
851 	}
852 }
853 
854 static const struct got_error *
855 ensure_proc_is_reading(struct gotd_client *client,
856     struct gotd_child_proc *proc)
857 {
858 	if (!client_is_reading(client)) {
859 		kill_proc(proc, 1);
860 		return got_error_fmt(GOT_ERR_BAD_PACKET,
861 		    "PID %d handled a read-request for uid %d but this "
862 		    "user is not reading from a repository", proc->pid,
863 		    client->euid);
864 	}
865 
866 	return NULL;
867 }
868 
869 static const struct got_error *
870 ensure_proc_is_writing(struct gotd_client *client,
871     struct gotd_child_proc *proc)
872 {
873 	if (!client_is_writing(client)) {
874 		kill_proc(proc, 1);
875 		return got_error_fmt(GOT_ERR_BAD_PACKET,
876 		    "PID %d handled a write-request for uid %d but this "
877 		    "user is not writing to a repository", proc->pid,
878 		    client->euid);
879 	}
880 
881 	return NULL;
882 }
883 
884 static int
885 verify_imsg_src(struct gotd_client *client, struct gotd_child_proc *proc,
886     struct imsg *imsg)
887 {
888 	const struct got_error *err;
889 	int ret = 0;
890 
891 	if (proc->type == PROC_REPO_READ || proc->type == PROC_REPO_WRITE) {
892 		if (client->repo == NULL)
893 			fatalx("no process found for uid %d", client->euid);
894 		if (proc->pid != client->repo->pid) {
895 			kill_proc(proc, 1);
896 			log_warnx("received message from PID %d for uid %d, "
897 			    "while PID %d is the process serving this user",
898 			    proc->pid, client->euid, client->repo->pid);
899 			return 0;
900 		}
901 	}
902 	if (proc->type == PROC_SESSION_READ ||
903 	    proc->type == PROC_SESSION_WRITE) {
904 		if (client->session == NULL) {
905 			log_warnx("no session found for uid %d", client->euid);
906 			return 0;
907 		}
908 		if (proc->pid != client->session->pid) {
909 			kill_proc(proc, 1);
910 			log_warnx("received message from PID %d for uid %d, "
911 			    "while PID %d is the process serving this user",
912 			    proc->pid, client->euid, client->session->pid);
913 			return 0;
914 		}
915 	}
916 
917 	switch (imsg->hdr.type) {
918 	case GOTD_IMSG_ERROR:
919 		ret = 1;
920 		break;
921 	case GOTD_IMSG_CONNECT:
922 		if (proc->type != PROC_LISTEN) {
923 			err = got_error_fmt(GOT_ERR_BAD_PACKET,
924 			    "new connection for uid %d from PID %d "
925 			    "which is not the listen process",
926 			    proc->pid, client->euid);
927 		} else
928 			ret = 1;
929 		break;
930 	case GOTD_IMSG_ACCESS_GRANTED:
931 		if (proc->type != PROC_AUTH) {
932 			err = got_error_fmt(GOT_ERR_BAD_PACKET,
933 			    "authentication of uid %d from PID %d "
934 			    "which is not the auth process",
935 			    proc->pid, client->euid);
936 		} else
937 			ret = 1;
938 		break;
939 	case GOTD_IMSG_CLIENT_SESSION_READY:
940 		if (proc->type != PROC_SESSION_READ &&
941 		    proc->type != PROC_SESSION_WRITE) {
942 			err = got_error_fmt(GOT_ERR_BAD_PACKET,
943 			    "unexpected \"ready\" signal from PID %d",
944 			    proc->pid);
945 		} else
946 			ret = 1;
947 		break;
948 	case GOTD_IMSG_REPO_CHILD_READY:
949 		if (proc->type != PROC_REPO_READ &&
950 		    proc->type != PROC_REPO_WRITE) {
951 			err = got_error_fmt(GOT_ERR_BAD_PACKET,
952 			    "unexpected \"ready\" signal from PID %d",
953 			    proc->pid);
954 		} else
955 			ret = 1;
956 		break;
957 	case GOTD_IMSG_PACKFILE_DONE:
958 		err = ensure_proc_is_reading(client, proc);
959 		if (err)
960 			log_warnx("uid %d: %s", client->euid, err->msg);
961 		else
962 			ret = 1;
963 		break;
964 	case GOTD_IMSG_PACKFILE_INSTALL:
965 	case GOTD_IMSG_REF_UPDATES_START:
966 	case GOTD_IMSG_REF_UPDATE:
967 		err = ensure_proc_is_writing(client, proc);
968 		if (err)
969 			log_warnx("uid %d: %s", client->euid, err->msg);
970 		else
971 			ret = 1;
972 		break;
973 	default:
974 		log_debug("%s: unexpected imsg %d", __func__, imsg->hdr.type);
975 		break;
976 	}
977 
978 	return ret;
979 }
980 
981 static const struct got_error *
982 connect_repo_child(struct gotd_client *client,
983     struct gotd_child_proc *repo_proc)
984 {
985 	static const struct got_error *err;
986 	struct gotd_imsgev *session_iev = &client->session->iev;
987 	struct gotd_imsg_connect_repo_child ireq;
988 	int pipe[2];
989 
990 	if (client->state != GOTD_CLIENT_STATE_ACCESS_GRANTED)
991 		return got_error_msg(GOT_ERR_BAD_REQUEST,
992 		    "unexpected repo child ready signal received");
993 
994 	if (socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK,
995 	    PF_UNSPEC, pipe) == -1)
996 		fatal("socketpair");
997 
998 	memset(&ireq, 0, sizeof(ireq));
999 	ireq.client_id = client->id;
1000 	ireq.proc_id = repo_proc->type;
1001 
1002 	/* Pass repo child pipe to session child process. */
1003 	if (gotd_imsg_compose_event(session_iev, GOTD_IMSG_CONNECT_REPO_CHILD,
1004 	    PROC_GOTD, pipe[0], &ireq, sizeof(ireq)) == -1) {
1005 		err = got_error_from_errno("imsg compose CONNECT_REPO_CHILD");
1006 		close(pipe[0]);
1007 		close(pipe[1]);
1008 		return err;
1009 	}
1010 
1011 	/* Pass session child pipe to repo child process. */
1012 	if (gotd_imsg_compose_event(&repo_proc->iev,
1013 	    GOTD_IMSG_CONNECT_REPO_CHILD, PROC_GOTD, pipe[1], NULL, 0) == -1) {
1014 		err = got_error_from_errno("imsg compose CONNECT_REPO_CHILD");
1015 		close(pipe[1]);
1016 		return err;
1017 	}
1018 
1019 	return NULL;
1020 }
1021 
1022 static void
1023 gotd_dispatch_listener(int fd, short event, void *arg)
1024 {
1025 	struct gotd_imsgev *iev = arg;
1026 	struct imsgbuf *ibuf = &iev->ibuf;
1027 	struct gotd_child_proc *proc = gotd.listen_proc;
1028 	ssize_t n;
1029 	int shut = 0;
1030 	struct imsg imsg;
1031 
1032 	if (proc->iev.ibuf.fd != fd)
1033 		fatalx("%s: unexpected fd %d", __func__, fd);
1034 
1035 	if (event & EV_READ) {
1036 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1037 			fatal("imsg_read error");
1038 		if (n == 0) {
1039 			/* Connection closed. */
1040 			shut = 1;
1041 			goto done;
1042 		}
1043 	}
1044 
1045 	if (event & EV_WRITE) {
1046 		n = msgbuf_write(&ibuf->w);
1047 		if (n == -1 && errno != EAGAIN)
1048 			fatal("msgbuf_write");
1049 		if (n == 0) {
1050 			/* Connection closed. */
1051 			shut = 1;
1052 			goto done;
1053 		}
1054 	}
1055 
1056 	for (;;) {
1057 		const struct got_error *err = NULL;
1058 		struct gotd_client *client = NULL;
1059 		uint32_t client_id = 0;
1060 		int do_disconnect = 0;
1061 
1062 		if ((n = imsg_get(ibuf, &imsg)) == -1)
1063 			fatal("%s: imsg_get error", __func__);
1064 		if (n == 0)	/* No more messages. */
1065 			break;
1066 
1067 		switch (imsg.hdr.type) {
1068 		case GOTD_IMSG_ERROR:
1069 			do_disconnect = 1;
1070 			err = gotd_imsg_recv_error(&client_id, &imsg);
1071 			break;
1072 		case GOTD_IMSG_CONNECT:
1073 			err = recv_connect(&client_id, &imsg);
1074 			break;
1075 		default:
1076 			log_debug("unexpected imsg %d", imsg.hdr.type);
1077 			break;
1078 		}
1079 
1080 		client = find_client(client_id);
1081 		if (client == NULL) {
1082 			log_warnx("%s: client not found", __func__);
1083 			imsg_free(&imsg);
1084 			continue;
1085 		}
1086 
1087 		if (err)
1088 			log_warnx("uid %d: %s", client->euid, err->msg);
1089 
1090 		if (do_disconnect) {
1091 			if (err)
1092 				disconnect_on_error(client, err);
1093 			else
1094 				disconnect(client);
1095 		}
1096 
1097 		imsg_free(&imsg);
1098 	}
1099 done:
1100 	if (!shut) {
1101 		gotd_imsg_event_add(iev);
1102 	} else {
1103 		/* This pipe is dead. Remove its event handler */
1104 		event_del(&iev->ev);
1105 		event_loopexit(NULL);
1106 	}
1107 }
1108 
1109 static void
1110 gotd_dispatch_auth_child(int fd, short event, void *arg)
1111 {
1112 	const struct got_error *err = NULL;
1113 	struct gotd_imsgev *iev = arg;
1114 	struct imsgbuf *ibuf = &iev->ibuf;
1115 	struct gotd_client *client;
1116 	struct gotd_repo *repo = NULL;
1117 	ssize_t n;
1118 	int shut = 0;
1119 	struct imsg imsg;
1120 	uint32_t client_id = 0;
1121 	int do_disconnect = 0;
1122 
1123 	client = find_client_by_proc_fd(fd);
1124 	if (client == NULL) {
1125 		/* Can happen during process teardown. */
1126 		warnx("cannot find client for fd %d", fd);
1127 		shut = 1;
1128 		goto done;
1129 	}
1130 
1131 	if (client->auth == NULL)
1132 		fatalx("cannot find auth child process for fd %d", fd);
1133 
1134 	if (event & EV_READ) {
1135 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1136 			fatal("imsg_read error");
1137 		if (n == 0) {
1138 			/* Connection closed. */
1139 			shut = 1;
1140 			goto done;
1141 		}
1142 	}
1143 
1144 	if (event & EV_WRITE) {
1145 		n = msgbuf_write(&ibuf->w);
1146 		if (n == -1 && errno != EAGAIN)
1147 			fatal("msgbuf_write");
1148 		if (n == 0) {
1149 			/* Connection closed. */
1150 			shut = 1;
1151 		}
1152 		goto done;
1153 	}
1154 
1155 	if (client->auth->iev.ibuf.fd != fd)
1156 		fatalx("%s: unexpected fd %d", __func__, fd);
1157 
1158 	if ((n = imsg_get(ibuf, &imsg)) == -1)
1159 		fatal("%s: imsg_get error", __func__);
1160 	if (n == 0)	/* No more messages. */
1161 		return;
1162 
1163 	evtimer_del(&client->tmo);
1164 
1165 	switch (imsg.hdr.type) {
1166 	case GOTD_IMSG_ERROR:
1167 		do_disconnect = 1;
1168 		err = gotd_imsg_recv_error(&client_id, &imsg);
1169 		break;
1170 	case GOTD_IMSG_ACCESS_GRANTED:
1171 		client->state = GOTD_CLIENT_STATE_ACCESS_GRANTED;
1172 		break;
1173 	default:
1174 		do_disconnect = 1;
1175 		log_debug("unexpected imsg %d", imsg.hdr.type);
1176 		break;
1177 	}
1178 
1179 	if (!verify_imsg_src(client, client->auth, &imsg)) {
1180 		do_disconnect = 1;
1181 		log_debug("dropping imsg type %d from PID %d",
1182 		    imsg.hdr.type, client->auth->pid);
1183 	}
1184 	imsg_free(&imsg);
1185 
1186 	if (do_disconnect) {
1187 		if (err)
1188 			disconnect_on_error(client, err);
1189 		else
1190 			disconnect(client);
1191 		return;
1192 	}
1193 
1194 	repo = gotd_find_repo_by_name(client->auth->repo_name, &gotd);
1195 	if (repo == NULL) {
1196 		err = got_error(GOT_ERR_NOT_GIT_REPO);
1197 		goto done;
1198 	}
1199 	kill_auth_proc(client);
1200 
1201 	log_info("authenticated uid %d for repository %s",
1202 	    client->euid, repo->name);
1203 
1204 	err = start_session_child(client, repo, gotd.argv0,
1205 	    gotd.confpath, gotd.daemonize, gotd.verbosity);
1206 	if (err)
1207 		goto done;
1208 done:
1209 	if (err)
1210 		log_warnx("uid %d: %s", client->euid, err->msg);
1211 
1212 	/* We might have killed the auth process by now. */
1213 	if (client->auth != NULL) {
1214 		if (!shut) {
1215 			gotd_imsg_event_add(iev);
1216 		} else {
1217 			/* This pipe is dead. Remove its event handler */
1218 			event_del(&iev->ev);
1219 		}
1220 	}
1221 }
1222 
1223 static const struct got_error *
1224 connect_session(struct gotd_client *client)
1225 {
1226 	const struct got_error *err = NULL;
1227 	struct gotd_imsg_connect iconnect;
1228 	int s;
1229 
1230 	memset(&iconnect, 0, sizeof(iconnect));
1231 
1232 	s = dup(client->fd);
1233 	if (s == -1)
1234 		return got_error_from_errno("dup");
1235 
1236 	iconnect.client_id = client->id;
1237 	iconnect.euid = client->euid;
1238 	iconnect.egid = client->egid;
1239 
1240 	if (gotd_imsg_compose_event(&client->session->iev, GOTD_IMSG_CONNECT,
1241 	    PROC_GOTD, s, &iconnect, sizeof(iconnect)) == -1) {
1242 		err = got_error_from_errno("imsg compose CONNECT");
1243 		close(s);
1244 		return err;
1245 	}
1246 
1247 	/*
1248 	 * We are no longer interested in messages from this client.
1249 	 * Further client requests will be handled by the session process.
1250 	 */
1251 	msgbuf_clear(&client->iev.ibuf.w);
1252 	imsg_clear(&client->iev.ibuf);
1253 	event_del(&client->iev.ev);
1254 	client->fd = -1; /* will be closed via copy in client->iev.ibuf.fd */
1255 
1256 	return NULL;
1257 }
1258 
1259 static void
1260 gotd_dispatch_client_session(int fd, short event, void *arg)
1261 {
1262 	struct gotd_imsgev *iev = arg;
1263 	struct imsgbuf *ibuf = &iev->ibuf;
1264 	struct gotd_child_proc *proc = NULL;
1265 	struct gotd_client *client = NULL;
1266 	ssize_t n;
1267 	int shut = 0;
1268 	struct imsg imsg;
1269 
1270 	client = find_client_by_proc_fd(fd);
1271 	if (client == NULL) {
1272 		/* Can happen during process teardown. */
1273 		warnx("cannot find client for fd %d", fd);
1274 		shut = 1;
1275 		goto done;
1276 	}
1277 
1278 	if (event & EV_READ) {
1279 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1280 			fatal("imsg_read error");
1281 		if (n == 0) {
1282 			/* Connection closed. */
1283 			shut = 1;
1284 			goto done;
1285 		}
1286 	}
1287 
1288 	if (event & EV_WRITE) {
1289 		n = msgbuf_write(&ibuf->w);
1290 		if (n == -1 && errno != EAGAIN)
1291 			fatal("msgbuf_write");
1292 		if (n == 0) {
1293 			/* Connection closed. */
1294 			shut = 1;
1295 			goto done;
1296 		}
1297 	}
1298 
1299 	proc = client->session;
1300 	if (proc == NULL)
1301 		fatalx("cannot find session child process for fd %d", fd);
1302 
1303 	for (;;) {
1304 		const struct got_error *err = NULL;
1305 		uint32_t client_id = 0;
1306 		int do_disconnect = 0, do_start_repo_child = 0;
1307 
1308 		if ((n = imsg_get(ibuf, &imsg)) == -1)
1309 			fatal("%s: imsg_get error", __func__);
1310 		if (n == 0)	/* No more messages. */
1311 			break;
1312 
1313 		switch (imsg.hdr.type) {
1314 		case GOTD_IMSG_ERROR:
1315 			do_disconnect = 1;
1316 			err = gotd_imsg_recv_error(&client_id, &imsg);
1317 			break;
1318 		case GOTD_IMSG_CLIENT_SESSION_READY:
1319 			if (client->state != GOTD_CLIENT_STATE_ACCESS_GRANTED) {
1320 				err = got_error(GOT_ERR_PRIVSEP_MSG);
1321 				break;
1322 			}
1323 			do_start_repo_child = 1;
1324 			break;
1325 		case GOTD_IMSG_DISCONNECT:
1326 			do_disconnect = 1;
1327 			break;
1328 		default:
1329 			log_debug("unexpected imsg %d", imsg.hdr.type);
1330 			break;
1331 		}
1332 
1333 		if (!verify_imsg_src(client, proc, &imsg)) {
1334 			log_debug("dropping imsg type %d from PID %d",
1335 			    imsg.hdr.type, proc->pid);
1336 			imsg_free(&imsg);
1337 			continue;
1338 		}
1339 		if (err)
1340 			log_warnx("uid %d: %s", client->euid, err->msg);
1341 
1342 		if (do_start_repo_child) {
1343 			struct gotd_repo *repo;
1344 			const char *name = client->session->repo_name;
1345 
1346 			repo = gotd_find_repo_by_name(name, &gotd);
1347 			if (repo != NULL) {
1348 				enum gotd_procid proc_type;
1349 
1350 				if (client->required_auth & GOTD_AUTH_WRITE)
1351 					proc_type = PROC_REPO_WRITE;
1352 				else
1353 					proc_type = PROC_REPO_READ;
1354 
1355 				err = start_repo_child(client, proc_type, repo,
1356 				    gotd.argv0, gotd.confpath, gotd.daemonize,
1357 				    gotd.verbosity);
1358 			} else
1359 				err = got_error(GOT_ERR_NOT_GIT_REPO);
1360 
1361 			if (err) {
1362 				log_warnx("uid %d: %s", client->euid, err->msg);
1363 				do_disconnect = 1;
1364 			}
1365 		}
1366 
1367 		if (do_disconnect) {
1368 			if (err)
1369 				disconnect_on_error(client, err);
1370 			else
1371 				disconnect(client);
1372 		}
1373 
1374 		imsg_free(&imsg);
1375 	}
1376 done:
1377 	if (!shut) {
1378 		gotd_imsg_event_add(iev);
1379 	} else {
1380 		/* This pipe is dead. Remove its event handler */
1381 		event_del(&iev->ev);
1382 		disconnect(client);
1383 	}
1384 }
1385 
1386 static void
1387 gotd_dispatch_repo_child(int fd, short event, void *arg)
1388 {
1389 	struct gotd_imsgev *iev = arg;
1390 	struct imsgbuf *ibuf = &iev->ibuf;
1391 	struct gotd_child_proc *proc = NULL;
1392 	struct gotd_client *client;
1393 	ssize_t n;
1394 	int shut = 0;
1395 	struct imsg imsg;
1396 
1397 	client = find_client_by_proc_fd(fd);
1398 	if (client == NULL) {
1399 		/* Can happen during process teardown. */
1400 		warnx("cannot find client for fd %d", fd);
1401 		shut = 1;
1402 		goto done;
1403 	}
1404 
1405 	if (event & EV_READ) {
1406 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1407 			fatal("imsg_read error");
1408 		if (n == 0) {
1409 			/* Connection closed. */
1410 			shut = 1;
1411 			goto done;
1412 		}
1413 	}
1414 
1415 	if (event & EV_WRITE) {
1416 		n = msgbuf_write(&ibuf->w);
1417 		if (n == -1 && errno != EAGAIN)
1418 			fatal("msgbuf_write");
1419 		if (n == 0) {
1420 			/* Connection closed. */
1421 			shut = 1;
1422 			goto done;
1423 		}
1424 	}
1425 
1426 	proc = client->repo;
1427 	if (proc == NULL)
1428 		fatalx("cannot find child process for fd %d", fd);
1429 
1430 	for (;;) {
1431 		const struct got_error *err = NULL;
1432 		uint32_t client_id = 0;
1433 		int do_disconnect = 0;
1434 
1435 		if ((n = imsg_get(ibuf, &imsg)) == -1)
1436 			fatal("%s: imsg_get error", __func__);
1437 		if (n == 0)	/* No more messages. */
1438 			break;
1439 
1440 		switch (imsg.hdr.type) {
1441 		case GOTD_IMSG_ERROR:
1442 			do_disconnect = 1;
1443 			err = gotd_imsg_recv_error(&client_id, &imsg);
1444 			break;
1445 		case GOTD_IMSG_REPO_CHILD_READY:
1446 			err = connect_session(client);
1447 			if (err)
1448 				break;
1449 			err = connect_repo_child(client, proc);
1450 			break;
1451 		default:
1452 			log_debug("unexpected imsg %d", imsg.hdr.type);
1453 			break;
1454 		}
1455 
1456 		if (!verify_imsg_src(client, proc, &imsg)) {
1457 			log_debug("dropping imsg type %d from PID %d",
1458 			    imsg.hdr.type, proc->pid);
1459 			imsg_free(&imsg);
1460 			continue;
1461 		}
1462 		if (err)
1463 			log_warnx("uid %d: %s", client->euid, err->msg);
1464 
1465 		if (do_disconnect) {
1466 			if (err)
1467 				disconnect_on_error(client, err);
1468 			else
1469 				disconnect(client);
1470 		}
1471 
1472 		imsg_free(&imsg);
1473 	}
1474 done:
1475 	if (!shut) {
1476 		gotd_imsg_event_add(iev);
1477 	} else {
1478 		/* This pipe is dead. Remove its event handler */
1479 		event_del(&iev->ev);
1480 		disconnect(client);
1481 	}
1482 }
1483 
1484 static pid_t
1485 start_child(enum gotd_procid proc_id, const char *repo_path,
1486     char *argv0, const char *confpath, int fd, int daemonize, int verbosity)
1487 {
1488 	char	*argv[11];
1489 	int	 argc = 0;
1490 	pid_t	 pid;
1491 
1492 	switch (pid = fork()) {
1493 	case -1:
1494 		fatal("cannot fork");
1495 	case 0:
1496 		break;
1497 	default:
1498 		close(fd);
1499 		return pid;
1500 	}
1501 
1502 	if (fd != GOTD_FILENO_MSG_PIPE) {
1503 		if (dup2(fd, GOTD_FILENO_MSG_PIPE) == -1)
1504 			fatal("cannot setup imsg fd");
1505 	} else if (fcntl(fd, F_SETFD, 0) == -1)
1506 		fatal("cannot setup imsg fd");
1507 
1508 	argv[argc++] = argv0;
1509 	switch (proc_id) {
1510 	case PROC_LISTEN:
1511 		argv[argc++] = (char *)"-L";
1512 		break;
1513 	case PROC_AUTH:
1514 		argv[argc++] = (char *)"-A";
1515 		break;
1516 	case PROC_SESSION_READ:
1517 		argv[argc++] = (char *)"-s";
1518 		break;
1519 	case PROC_SESSION_WRITE:
1520 		argv[argc++] = (char *)"-S";
1521 		break;
1522 	case PROC_REPO_READ:
1523 		argv[argc++] = (char *)"-R";
1524 		break;
1525 	case PROC_REPO_WRITE:
1526 		argv[argc++] = (char *)"-W";
1527 		break;
1528 	default:
1529 		fatalx("invalid process id %d", proc_id);
1530 	}
1531 
1532 	argv[argc++] = (char *)"-f";
1533 	argv[argc++] = (char *)confpath;
1534 
1535 	if (repo_path) {
1536 		argv[argc++] = (char *)"-P";
1537 		argv[argc++] = (char *)repo_path;
1538 	}
1539 
1540 	if (!daemonize)
1541 		argv[argc++] = (char *)"-d";
1542 	if (verbosity > 0)
1543 		argv[argc++] = (char *)"-v";
1544 	if (verbosity > 1)
1545 		argv[argc++] = (char *)"-v";
1546 	argv[argc++] = NULL;
1547 
1548 	execvp(argv0, argv);
1549 	fatal("execvp");
1550 }
1551 
1552 static void
1553 start_listener(char *argv0, const char *confpath, int daemonize, int verbosity)
1554 {
1555 	struct gotd_child_proc *proc;
1556 
1557 	proc = calloc(1, sizeof(*proc));
1558 	if (proc == NULL)
1559 		fatal("calloc");
1560 
1561 	TAILQ_INSERT_HEAD(&procs, proc, entry);
1562 
1563 	/* proc->tmo is initialized in main() after event_init() */
1564 
1565 	proc->type = PROC_LISTEN;
1566 
1567 	if (socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK,
1568 	    PF_UNSPEC, proc->pipe) == -1)
1569 		fatal("socketpair");
1570 
1571 	proc->pid = start_child(proc->type, NULL, argv0, confpath,
1572 	    proc->pipe[1], daemonize, verbosity);
1573 	imsg_init(&proc->iev.ibuf, proc->pipe[0]);
1574 	proc->iev.handler = gotd_dispatch_listener;
1575 	proc->iev.events = EV_READ;
1576 	proc->iev.handler_arg = NULL;
1577 
1578 	gotd.listen_proc = proc;
1579 }
1580 
1581 static const struct got_error *
1582 start_session_child(struct gotd_client *client, struct gotd_repo *repo,
1583     char *argv0, const char *confpath, int daemonize, int verbosity)
1584 {
1585 	struct gotd_child_proc *proc;
1586 
1587 	proc = calloc(1, sizeof(*proc));
1588 	if (proc == NULL)
1589 		return got_error_from_errno("calloc");
1590 
1591 	TAILQ_INSERT_HEAD(&procs, proc, entry);
1592 	evtimer_set(&proc->tmo, kill_proc_timeout, proc);
1593 
1594 	if (client_is_reading(client))
1595 		proc->type = PROC_SESSION_READ;
1596 	else
1597 		proc->type = PROC_SESSION_WRITE;
1598 	if (strlcpy(proc->repo_name, repo->name,
1599 	    sizeof(proc->repo_name)) >= sizeof(proc->repo_name))
1600 		fatalx("repository name too long: %s", repo->name);
1601 	log_debug("starting client uid %d session for repository %s",
1602 	    client->euid, repo->name);
1603 	if (strlcpy(proc->repo_path, repo->path, sizeof(proc->repo_path)) >=
1604 	    sizeof(proc->repo_path))
1605 		fatalx("repository path too long: %s", repo->path);
1606 	if (socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK,
1607 	    PF_UNSPEC, proc->pipe) == -1)
1608 		fatal("socketpair");
1609 	proc->pid = start_child(proc->type, proc->repo_path, argv0,
1610 	    confpath, proc->pipe[1], daemonize, verbosity);
1611 	imsg_init(&proc->iev.ibuf, proc->pipe[0]);
1612 	log_debug("proc %s %s is on fd %d",
1613 	    gotd_proc_names[proc->type], proc->repo_path,
1614 	    proc->pipe[0]);
1615 	proc->iev.handler = gotd_dispatch_client_session;
1616 	proc->iev.events = EV_READ;
1617 	proc->iev.handler_arg = NULL;
1618 	event_set(&proc->iev.ev, proc->iev.ibuf.fd, EV_READ,
1619 	    gotd_dispatch_client_session, &proc->iev);
1620 	gotd_imsg_event_add(&proc->iev);
1621 
1622 	client->session = proc;
1623 	return NULL;
1624 }
1625 
1626 static const struct got_error *
1627 start_repo_child(struct gotd_client *client, enum gotd_procid proc_type,
1628     struct gotd_repo *repo, char *argv0, const char *confpath,
1629     int daemonize, int verbosity)
1630 {
1631 	struct gotd_child_proc *proc;
1632 
1633 	if (proc_type != PROC_REPO_READ && proc_type != PROC_REPO_WRITE)
1634 		return got_error_msg(GOT_ERR_NOT_IMPL, "bad process type");
1635 
1636 	proc = calloc(1, sizeof(*proc));
1637 	if (proc == NULL)
1638 		return got_error_from_errno("calloc");
1639 
1640 	TAILQ_INSERT_HEAD(&procs, proc, entry);
1641 	evtimer_set(&proc->tmo, kill_proc_timeout, proc);
1642 
1643 	proc->type = proc_type;
1644 	if (strlcpy(proc->repo_name, repo->name,
1645 	    sizeof(proc->repo_name)) >= sizeof(proc->repo_name))
1646 		fatalx("repository name too long: %s", repo->name);
1647 	log_debug("starting %s for repository %s",
1648 	    proc->type == PROC_REPO_READ ? "reader" : "writer", repo->name);
1649 	if (strlcpy(proc->repo_path, repo->path, sizeof(proc->repo_path)) >=
1650 	    sizeof(proc->repo_path))
1651 		fatalx("repository path too long: %s", repo->path);
1652 	if (socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK,
1653 	    PF_UNSPEC, proc->pipe) == -1)
1654 		fatal("socketpair");
1655 	proc->pid = start_child(proc->type, proc->repo_path, argv0,
1656 	    confpath, proc->pipe[1], daemonize, verbosity);
1657 	imsg_init(&proc->iev.ibuf, proc->pipe[0]);
1658 	log_debug("proc %s %s is on fd %d",
1659 	    gotd_proc_names[proc->type], proc->repo_path,
1660 	    proc->pipe[0]);
1661 	proc->iev.handler = gotd_dispatch_repo_child;
1662 	proc->iev.events = EV_READ;
1663 	proc->iev.handler_arg = NULL;
1664 	event_set(&proc->iev.ev, proc->iev.ibuf.fd, EV_READ,
1665 	    gotd_dispatch_repo_child, &proc->iev);
1666 	gotd_imsg_event_add(&proc->iev);
1667 
1668 	client->repo = proc;
1669 	return NULL;
1670 }
1671 
1672 static const struct got_error *
1673 start_auth_child(struct gotd_client *client, int required_auth,
1674     struct gotd_repo *repo, char *argv0, const char *confpath,
1675     int daemonize, int verbosity)
1676 {
1677 	const struct got_error *err = NULL;
1678 	struct gotd_child_proc *proc;
1679 	struct gotd_imsg_auth iauth;
1680 	int fd;
1681 
1682 	memset(&iauth, 0, sizeof(iauth));
1683 
1684 	fd = dup(client->fd);
1685 	if (fd == -1)
1686 		return got_error_from_errno("dup");
1687 
1688 	proc = calloc(1, sizeof(*proc));
1689 	if (proc == NULL) {
1690 		err = got_error_from_errno("calloc");
1691 		close(fd);
1692 		return err;
1693 	}
1694 
1695 	TAILQ_INSERT_HEAD(&procs, proc, entry);
1696 	evtimer_set(&proc->tmo, kill_proc_timeout, proc);
1697 
1698 	proc->type = PROC_AUTH;
1699 	if (strlcpy(proc->repo_name, repo->name,
1700 	    sizeof(proc->repo_name)) >= sizeof(proc->repo_name))
1701 		fatalx("repository name too long: %s", repo->name);
1702 	log_debug("starting auth for uid %d repository %s",
1703 	    client->euid, repo->name);
1704 	if (strlcpy(proc->repo_path, repo->path, sizeof(proc->repo_path)) >=
1705 	    sizeof(proc->repo_path))
1706 		fatalx("repository path too long: %s", repo->path);
1707 	if (socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK,
1708 	    PF_UNSPEC, proc->pipe) == -1)
1709 		fatal("socketpair");
1710 	proc->pid = start_child(proc->type, proc->repo_path, argv0,
1711 	    confpath, proc->pipe[1], daemonize, verbosity);
1712 	imsg_init(&proc->iev.ibuf, proc->pipe[0]);
1713 	log_debug("proc %s %s is on fd %d",
1714 	    gotd_proc_names[proc->type], proc->repo_path,
1715 	    proc->pipe[0]);
1716 	proc->iev.handler = gotd_dispatch_auth_child;
1717 	proc->iev.events = EV_READ;
1718 	proc->iev.handler_arg = NULL;
1719 	event_set(&proc->iev.ev, proc->iev.ibuf.fd, EV_READ,
1720 	    gotd_dispatch_auth_child, &proc->iev);
1721 	gotd_imsg_event_add(&proc->iev);
1722 
1723 	iauth.euid = client->euid;
1724 	iauth.egid = client->egid;
1725 	iauth.required_auth = required_auth;
1726 	iauth.client_id = client->id;
1727 	if (gotd_imsg_compose_event(&proc->iev, GOTD_IMSG_AUTHENTICATE,
1728 	    PROC_GOTD, fd, &iauth, sizeof(iauth)) == -1) {
1729 		log_warn("imsg compose AUTHENTICATE");
1730 		close(fd);
1731 		/* Let the auth_timeout handler tidy up. */
1732 	}
1733 
1734 	client->auth = proc;
1735 	client->required_auth = required_auth;
1736 	return NULL;
1737 }
1738 
1739 static void
1740 apply_unveil_repo_readonly(const char *repo_path, int need_tmpdir)
1741 {
1742 	if (need_tmpdir) {
1743 		if (unveil(GOT_TMPDIR_STR, "rwc") == -1)
1744 			fatal("unveil %s", GOT_TMPDIR_STR);
1745 	}
1746 
1747 	if (unveil(repo_path, "r") == -1)
1748 		fatal("unveil %s", repo_path);
1749 
1750 	if (unveil(NULL, NULL) == -1)
1751 		fatal("unveil");
1752 }
1753 
1754 static void
1755 apply_unveil_repo_readwrite(const char *repo_path)
1756 {
1757 	if (unveil(repo_path, "rwc") == -1)
1758 		fatal("unveil %s", repo_path);
1759 
1760 	if (unveil(GOT_TMPDIR_STR, "rwc") == -1)
1761 		fatal("unveil %s", GOT_TMPDIR_STR);
1762 
1763 	if (unveil(NULL, NULL) == -1)
1764 		fatal("unveil");
1765 }
1766 
1767 static void
1768 apply_unveil_none(void)
1769 {
1770 	if (unveil("/", "") == -1)
1771 		fatal("unveil");
1772 
1773 	if (unveil(NULL, NULL) == -1)
1774 		fatal("unveil");
1775 }
1776 
1777 static void
1778 apply_unveil_selfexec(void)
1779 {
1780 	if (unveil(gotd.argv0, "x") == -1)
1781 		fatal("unveil %s", gotd.argv0);
1782 
1783 	if (unveil(NULL, NULL) == -1)
1784 		fatal("unveil");
1785 }
1786 
1787 int
1788 main(int argc, char **argv)
1789 {
1790 	const struct got_error *error = NULL;
1791 	int ch, fd = -1, daemonize = 1, verbosity = 0, noaction = 0;
1792 	const char *confpath = GOTD_CONF_PATH;
1793 	char *argv0 = argv[0];
1794 	char title[2048];
1795 	struct passwd *pw = NULL;
1796 	char *repo_path = NULL;
1797 	enum gotd_procid proc_id = PROC_GOTD;
1798 	struct event evsigint, evsigterm, evsighup, evsigusr1, evsigchld;
1799 	int *pack_fds = NULL, *temp_fds = NULL;
1800 	struct gotd_repo *repo = NULL;
1801 
1802 	TAILQ_INIT(&procs);
1803 
1804 	log_init(1, LOG_DAEMON); /* Log to stderr until daemonized. */
1805 
1806 	while ((ch = getopt(argc, argv, "Adf:LnP:RsSvW")) != -1) {
1807 		switch (ch) {
1808 		case 'A':
1809 			proc_id = PROC_AUTH;
1810 			break;
1811 		case 'd':
1812 			daemonize = 0;
1813 			break;
1814 		case 'f':
1815 			confpath = optarg;
1816 			break;
1817 		case 'L':
1818 			proc_id = PROC_LISTEN;
1819 			break;
1820 		case 'n':
1821 			noaction = 1;
1822 			break;
1823 		case 'P':
1824 			repo_path = realpath(optarg, NULL);
1825 			if (repo_path == NULL)
1826 				fatal("realpath '%s'", optarg);
1827 			break;
1828 		case 'R':
1829 			proc_id = PROC_REPO_READ;
1830 			break;
1831 		case 's':
1832 			proc_id = PROC_SESSION_READ;
1833 			break;
1834 		case 'S':
1835 			proc_id = PROC_SESSION_WRITE;
1836 			break;
1837 		case 'v':
1838 			if (verbosity < 3)
1839 				verbosity++;
1840 			break;
1841 		case 'W':
1842 			proc_id = PROC_REPO_WRITE;
1843 			break;
1844 		default:
1845 			usage();
1846 		}
1847 	}
1848 
1849 	argc -= optind;
1850 	argv += optind;
1851 
1852 	if (argc != 0)
1853 		usage();
1854 
1855 	if (geteuid() && (proc_id == PROC_GOTD || proc_id == PROC_LISTEN))
1856 		fatalx("need root privileges");
1857 
1858 	if (parse_config(confpath, proc_id, &gotd, 1) != 0)
1859 		return 1;
1860 
1861 	pw = getpwnam(gotd.user_name);
1862 	if (pw == NULL)
1863 		fatalx("user %s not found", gotd.user_name);
1864 
1865 	if (pw->pw_uid == 0)
1866 		fatalx("cannot run %s as the superuser", getprogname());
1867 
1868 	if (noaction) {
1869 		fprintf(stderr, "configuration OK\n");
1870 		return 0;
1871 	}
1872 
1873 	gotd.argv0 = argv0;
1874 	gotd.daemonize = daemonize;
1875 	gotd.verbosity = verbosity;
1876 	gotd.confpath = confpath;
1877 
1878 	/* Require an absolute path in argv[0] for reliable re-exec. */
1879 	if (!got_path_is_absolute(argv0))
1880 		fatalx("bad path \"%s\": must be an absolute path", argv0);
1881 
1882 	log_init(daemonize ? 0 : 1, LOG_DAEMON);
1883 	log_setverbose(verbosity);
1884 
1885 	if (proc_id == PROC_GOTD) {
1886 		snprintf(title, sizeof(title), "%s", gotd_proc_names[proc_id]);
1887 		arc4random_buf(&clients_hash_key, sizeof(clients_hash_key));
1888 		if (daemonize && daemon(1, 0) == -1)
1889 			fatal("daemon");
1890 		gotd.pid = getpid();
1891 		start_listener(argv0, confpath, daemonize, verbosity);
1892 	} else if (proc_id == PROC_LISTEN) {
1893 		snprintf(title, sizeof(title), "%s", gotd_proc_names[proc_id]);
1894 		if (verbosity) {
1895 			log_info("socket: %s", gotd.unix_socket_path);
1896 			log_info("user: %s", pw->pw_name);
1897 		}
1898 
1899 		fd = unix_socket_listen(gotd.unix_socket_path, pw->pw_uid,
1900 		    pw->pw_gid);
1901 		if (fd == -1) {
1902 			fatal("cannot listen on unix socket %s",
1903 			    gotd.unix_socket_path);
1904 		}
1905 	} else if (proc_id == PROC_AUTH) {
1906 		snprintf(title, sizeof(title), "%s %s",
1907 		    gotd_proc_names[proc_id], repo_path);
1908 	} else if (proc_id == PROC_REPO_READ || proc_id == PROC_REPO_WRITE ||
1909 	    proc_id == PROC_SESSION_READ || proc_id == PROC_SESSION_WRITE) {
1910 		error = got_repo_pack_fds_open(&pack_fds);
1911 		if (error != NULL)
1912 			fatalx("cannot open pack tempfiles: %s", error->msg);
1913 		error = got_repo_temp_fds_open(&temp_fds);
1914 		if (error != NULL)
1915 			fatalx("cannot open pack tempfiles: %s", error->msg);
1916 		if (repo_path == NULL)
1917 			fatalx("repository path not specified");
1918 		snprintf(title, sizeof(title), "%s %s",
1919 		    gotd_proc_names[proc_id], repo_path);
1920 	} else
1921 		fatal("invalid process id %d", proc_id);
1922 
1923 	setproctitle("%s", title);
1924 	log_procinit(title);
1925 
1926 	/* Drop root privileges. */
1927 	if (setgid(pw->pw_gid) == -1)
1928 		fatal("setgid %d failed", pw->pw_gid);
1929 	if (setuid(pw->pw_uid) == -1)
1930 		fatal("setuid %d failed", pw->pw_uid);
1931 
1932 	event_init();
1933 
1934 	switch (proc_id) {
1935 	case PROC_GOTD:
1936 #ifndef PROFILE
1937 		/* "exec" promise will be limited to argv[0] via unveil(2). */
1938 		if (pledge("stdio proc exec sendfd recvfd unveil", NULL) == -1)
1939 			err(1, "pledge");
1940 #endif
1941 		break;
1942 	case PROC_LISTEN:
1943 #ifndef PROFILE
1944 		if (pledge("stdio sendfd unix unveil", NULL) == -1)
1945 			err(1, "pledge");
1946 #endif
1947 		/*
1948 		 * Ensure that AF_UNIX bind(2) cannot be used with any other
1949 		 * sockets by revoking all filesystem access via unveil(2).
1950 		 */
1951 		apply_unveil_none();
1952 
1953 		listen_main(title, fd, gotd.connection_limits,
1954 		    gotd.nconnection_limits);
1955 		/* NOTREACHED */
1956 		break;
1957 	case PROC_AUTH:
1958 #ifndef PROFILE
1959 		if (pledge("stdio getpw recvfd unix unveil", NULL) == -1)
1960 			err(1, "pledge");
1961 #endif
1962 		/*
1963 		 * We need the "unix" pledge promise for getpeername(2) only.
1964 		 * Ensure that AF_UNIX bind(2) cannot be used by revoking all
1965 		 * filesystem access via unveil(2). Access to password database
1966 		 * files will still work since "getpw" bypasses unveil(2).
1967 		 */
1968 		apply_unveil_none();
1969 
1970 		auth_main(title, &gotd.repos, repo_path);
1971 		/* NOTREACHED */
1972 		break;
1973 	case PROC_SESSION_READ:
1974 	case PROC_SESSION_WRITE:
1975 #ifndef PROFILE
1976 		/*
1977 		 * The "recvfd" promise is only needed during setup and
1978 		 * will be removed in a later pledge(2) call.
1979 		 */
1980 		if (pledge("stdio rpath wpath cpath recvfd sendfd fattr flock "
1981 		    "unveil", NULL) == -1)
1982 			err(1, "pledge");
1983 #endif
1984 		if (proc_id == PROC_SESSION_READ)
1985 			apply_unveil_repo_readonly(repo_path, 1);
1986 		else
1987 			apply_unveil_repo_readwrite(repo_path);
1988 		session_main(title, repo_path, pack_fds, temp_fds,
1989 		    &gotd.request_timeout, proc_id);
1990 		/* NOTREACHED */
1991 		break;
1992 	case PROC_REPO_READ:
1993 #ifndef PROFILE
1994 		if (pledge("stdio rpath recvfd unveil", NULL) == -1)
1995 			err(1, "pledge");
1996 #endif
1997 		apply_unveil_repo_readonly(repo_path, 0);
1998 		repo_read_main(title, repo_path, pack_fds, temp_fds);
1999 		/* NOTREACHED */
2000 		exit(0);
2001 	case PROC_REPO_WRITE:
2002 #ifndef PROFILE
2003 		if (pledge("stdio rpath recvfd unveil", NULL) == -1)
2004 			err(1, "pledge");
2005 #endif
2006 		apply_unveil_repo_readonly(repo_path, 0);
2007 		repo = gotd_find_repo_by_path(repo_path, &gotd);
2008 		if (repo == NULL)
2009 			fatalx("no repository for path %s", repo_path);
2010 		repo_write_main(title, repo_path, pack_fds, temp_fds,
2011 		    &repo->protected_tag_namespaces,
2012 		    &repo->protected_branch_namespaces,
2013 		    &repo->protected_branches);
2014 		/* NOTREACHED */
2015 		exit(0);
2016 	default:
2017 		fatal("invalid process id %d", proc_id);
2018 	}
2019 
2020 	if (proc_id != PROC_GOTD)
2021 		fatal("invalid process id %d", proc_id);
2022 
2023 	evtimer_set(&gotd.listen_proc->tmo, kill_proc_timeout,
2024 	    gotd.listen_proc);
2025 
2026 	apply_unveil_selfexec();
2027 
2028 	signal_set(&evsigint, SIGINT, gotd_sighdlr, NULL);
2029 	signal_set(&evsigterm, SIGTERM, gotd_sighdlr, NULL);
2030 	signal_set(&evsighup, SIGHUP, gotd_sighdlr, NULL);
2031 	signal_set(&evsigusr1, SIGUSR1, gotd_sighdlr, NULL);
2032 	signal_set(&evsigchld, SIGCHLD, gotd_sighdlr, NULL);
2033 	signal(SIGPIPE, SIG_IGN);
2034 
2035 	signal_add(&evsigint, NULL);
2036 	signal_add(&evsigterm, NULL);
2037 	signal_add(&evsighup, NULL);
2038 	signal_add(&evsigusr1, NULL);
2039 	signal_add(&evsigchld, NULL);
2040 
2041 	gotd_imsg_event_add(&gotd.listen_proc->iev);
2042 
2043 	event_dispatch();
2044 
2045 	free(repo_path);
2046 	gotd_shutdown();
2047 
2048 	return 0;
2049 }