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Date:: Thu Jun 22 21:25:08 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/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 <imsg.h>
33 #include <sha1.h>
34 #include <sha2.h>
35 #include <signal.h>
36 #include <siphash.h>
37 #include <stdarg.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <syslog.h>
42 #include <unistd.h>
43 
44 #include "got_error.h"
45 #include "got_opentemp.h"
46 #include "got_path.h"
47 #include "got_repository.h"
48 #include "got_object.h"
49 #include "got_reference.h"
50 
51 #include "got_lib_delta.h"
52 #include "got_lib_object.h"
53 #include "got_lib_object_cache.h"
54 #include "got_lib_hash.h"
55 #include "got_lib_gitproto.h"
56 #include "got_lib_pack.h"
57 #include "got_lib_repository.h"
58 
59 #include "gotd.h"
60 #include "log.h"
61 #include "listen.h"
62 #include "auth.h"
63 #include "session.h"
64 #include "repo_read.h"
65 #include "repo_write.h"
66 
67 #ifndef nitems
68 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
69 #endif
70 
71 enum gotd_client_state {
72 	GOTD_CLIENT_STATE_NEW,
73 	GOTD_CLIENT_STATE_ACCESS_GRANTED,
74 };
75 
76 struct gotd_child_proc {
77 	pid_t				 pid;
78 	enum gotd_procid		 type;
79 	char				 repo_name[NAME_MAX];
80 	char				 repo_path[PATH_MAX];
81 	int				 pipe[2];
82 	struct gotd_imsgev		 iev;
83 	struct event			 tmo;
84 
85 	TAILQ_ENTRY(gotd_child_proc)	 entry;
86 };
87 TAILQ_HEAD(gotd_procs, gotd_child_proc) procs;
88 
89 struct gotd_client {
90 	STAILQ_ENTRY(gotd_client)	 entry;
91 	enum gotd_client_state		 state;
92 	uint32_t			 id;
93 	int				 fd;
94 	struct gotd_imsgev		 iev;
95 	struct event			 tmo;
96 	uid_t				 euid;
97 	gid_t				 egid;
98 	struct gotd_child_proc		*repo;
99 	struct gotd_child_proc		*auth;
100 	struct gotd_child_proc		*session;
101 	int				 required_auth;
102 };
103 STAILQ_HEAD(gotd_clients, gotd_client);
104 
105 static struct gotd_clients gotd_clients[GOTD_CLIENT_TABLE_SIZE];
106 static SIPHASH_KEY clients_hash_key;
107 volatile int client_cnt;
108 static struct timeval auth_timeout = { 5, 0 };
109 static struct gotd gotd;
110 
111 void gotd_sighdlr(int sig, short event, void *arg);
112 static void gotd_shutdown(void);
113 static const struct got_error *start_session_child(struct gotd_client *,
114     struct gotd_repo *, char *, const char *, int, int);
115 static const struct got_error *start_repo_child(struct gotd_client *,
116     enum gotd_procid, struct gotd_repo *, char *, const char *, int, int);
117 static const struct got_error *start_auth_child(struct gotd_client *, int,
118     struct gotd_repo *, char *, const char *, int, int);
119 static void kill_proc(struct gotd_child_proc *, int);
120 static void disconnect(struct gotd_client *);
121 
122 __dead static void
123 usage(void)
124 {
125 	fprintf(stderr, "usage: %s [-dnv] [-f config-file]\n", getprogname());
126 	exit(1);
127 }
128 
129 static int
130 unix_socket_listen(const char *unix_socket_path, uid_t uid, gid_t gid)
131 {
132 	struct sockaddr_un sun;
133 	int fd = -1;
134 	mode_t old_umask, mode;
135 
136 	fd = socket(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK| SOCK_CLOEXEC, 0);
137 	if (fd == -1) {
138 		log_warn("socket");
139 		return -1;
140 	}
141 
142 	sun.sun_family = AF_UNIX;
143 	if (strlcpy(sun.sun_path, unix_socket_path,
144 	    sizeof(sun.sun_path)) >= sizeof(sun.sun_path)) {
145 		log_warnx("%s: name too long", unix_socket_path);
146 		close(fd);
147 		return -1;
148 	}
149 
150 	if (unlink(unix_socket_path) == -1) {
151 		if (errno != ENOENT) {
152 			log_warn("unlink %s", unix_socket_path);
153 			close(fd);
154 			return -1;
155 		}
156 	}
157 
158 	old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);
159 	mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH;
160 
161 	if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
162 		log_warn("bind: %s", unix_socket_path);
163 		close(fd);
164 		umask(old_umask);
165 		return -1;
166 	}
167 
168 	umask(old_umask);
169 
170 	if (chmod(unix_socket_path, mode) == -1) {
171 		log_warn("chmod %o %s", mode, unix_socket_path);
172 		close(fd);
173 		unlink(unix_socket_path);
174 		return -1;
175 	}
176 
177 	if (chown(unix_socket_path, uid, gid) == -1) {
178 		log_warn("chown %s uid=%d gid=%d", unix_socket_path, uid, gid);
179 		close(fd);
180 		unlink(unix_socket_path);
181 		return -1;
182 	}
183 
184 	if (listen(fd, GOTD_UNIX_SOCKET_BACKLOG) == -1) {
185 		log_warn("listen");
186 		close(fd);
187 		unlink(unix_socket_path);
188 		return -1;
189 	}
190 
191 	return fd;
192 }
193 
194 static uint64_t
195 client_hash(uint32_t client_id)
196 {
197 	return SipHash24(&clients_hash_key, &client_id, sizeof(client_id));
198 }
199 
200 static void
201 add_client(struct gotd_client *client)
202 {
203 	uint64_t slot = client_hash(client->id) % nitems(gotd_clients);
204 	STAILQ_INSERT_HEAD(&gotd_clients[slot], client, entry);
205 	client_cnt++;
206 }
207 
208 static struct gotd_client *
209 find_client(uint32_t client_id)
210 {
211 	uint64_t slot;
212 	struct gotd_client *c;
213 
214 	slot = client_hash(client_id) % nitems(gotd_clients);
215 	STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
216 		if (c->id == client_id)
217 			return c;
218 	}
219 
220 	return NULL;
221 }
222 
223 static struct gotd_client *
224 find_client_by_proc_fd(int fd)
225 {
226 	uint64_t slot;
227 
228 	for (slot = 0; slot < nitems(gotd_clients); slot++) {
229 		struct gotd_client *c;
230 
231 		STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
232 			if (c->repo && c->repo->iev.ibuf.fd == fd)
233 				return c;
234 			if (c->auth && c->auth->iev.ibuf.fd == fd)
235 				return c;
236 			if (c->session && c->session->iev.ibuf.fd == fd)
237 				return c;
238 		}
239 	}
240 
241 	return NULL;
242 }
243 
244 static int
245 client_is_reading(struct gotd_client *client)
246 {
247 	return (client->required_auth &
248 	    (GOTD_AUTH_READ | GOTD_AUTH_WRITE)) == GOTD_AUTH_READ;
249 }
250 
251 static int
252 client_is_writing(struct gotd_client *client)
253 {
254 	return (client->required_auth &
255 	    (GOTD_AUTH_READ | GOTD_AUTH_WRITE)) ==
256 	    (GOTD_AUTH_READ | GOTD_AUTH_WRITE);
257 }
258 
259 static const struct got_error *
260 ensure_client_is_not_writing(struct gotd_client *client)
261 {
262 	if (client_is_writing(client)) {
263 		return got_error_fmt(GOT_ERR_BAD_PACKET,
264 		    "uid %d made a read-request but is writing to "
265 		    "a repository", client->euid);
266 	}
267 
268 	return NULL;
269 }
270 
271 static const struct got_error *
272 ensure_client_is_not_reading(struct gotd_client *client)
273 {
274 	if (client_is_reading(client)) {
275 		return got_error_fmt(GOT_ERR_BAD_PACKET,
276 		    "uid %d made a write-request but is reading from "
277 		    "a repository", client->euid);
278 	}
279 
280 	return NULL;
281 }
282 
283 static void
284 proc_done(struct gotd_child_proc *proc)
285 {
286 	struct gotd_client *client;
287 
288 	TAILQ_REMOVE(&procs, proc, entry);
289 
290 	client = find_client_by_proc_fd(proc->iev.ibuf.fd);
291 	if (client != NULL) {
292 		if (proc == client->repo)
293 			client->repo = NULL;
294 		if (proc == client->auth)
295 			client->auth = NULL;
296 		if (proc == client->session)
297 			client->session = NULL;
298 		disconnect(client);
299 	}
300 
301 	evtimer_del(&proc->tmo);
302 
303 	if (proc->iev.ibuf.fd != -1) {
304 		event_del(&proc->iev.ev);
305 		msgbuf_clear(&proc->iev.ibuf.w);
306 		close(proc->iev.ibuf.fd);
307 	}
308 
309 	free(proc);
310 }
311 
312 static void
313 kill_repo_proc(struct gotd_client *client)
314 {
315 	if (client->repo == NULL)
316 		return;
317 
318 	kill_proc(client->repo, 0);
319 	client->repo = NULL;
320 }
321 
322 static void
323 kill_auth_proc(struct gotd_client *client)
324 {
325 	if (client->auth == NULL)
326 		return;
327 
328 	kill_proc(client->auth, 0);
329 	client->auth = NULL;
330 }
331 
332 static void
333 kill_session_proc(struct gotd_client *client)
334 {
335 	if (client->session == NULL)
336 		return;
337 
338 	kill_proc(client->session, 0);
339 	client->session = NULL;
340 }
341 
342 static void
343 disconnect(struct gotd_client *client)
344 {
345 	struct gotd_imsg_disconnect idisconnect;
346 	struct gotd_child_proc *listen_proc = gotd.listen_proc;
347 	uint64_t slot;
348 
349 	log_debug("uid %d: disconnecting", client->euid);
350 
351 	kill_auth_proc(client);
352 	kill_session_proc(client);
353 	kill_repo_proc(client);
354 
355 	idisconnect.client_id = client->id;
356 	if (gotd_imsg_compose_event(&listen_proc->iev,
357 	    GOTD_IMSG_DISCONNECT, PROC_GOTD, -1,
358 	    &idisconnect, sizeof(idisconnect)) == -1)
359 		log_warn("imsg compose DISCONNECT");
360 
361 	slot = client_hash(client->id) % nitems(gotd_clients);
362 	STAILQ_REMOVE(&gotd_clients[slot], client, gotd_client, entry);
363 	imsg_clear(&client->iev.ibuf);
364 	event_del(&client->iev.ev);
365 	evtimer_del(&client->tmo);
366 	if (client->fd != -1)
367 		close(client->fd);
368 	else if (client->iev.ibuf.fd != -1)
369 		close(client->iev.ibuf.fd);
370 	free(client);
371 	client_cnt--;
372 }
373 
374 static void
375 disconnect_on_error(struct gotd_client *client, const struct got_error *err)
376 {
377 	struct imsgbuf ibuf;
378 
379 	log_warnx("uid %d: %s", client->euid, err->msg);
380 	if (err->code != GOT_ERR_EOF && client->fd != -1) {
381 		imsg_init(&ibuf, client->fd);
382 		gotd_imsg_send_error(&ibuf, 0, PROC_GOTD, err);
383 		imsg_clear(&ibuf);
384 	}
385 	disconnect(client);
386 }
387 
388 static const struct got_error *
389 send_repo_info(struct gotd_imsgev *iev, struct gotd_repo *repo)
390 {
391 	const struct got_error *err = NULL;
392 	struct gotd_imsg_info_repo irepo;
393 
394 	memset(&irepo, 0, sizeof(irepo));
395 
396 	if (strlcpy(irepo.repo_name, repo->name, sizeof(irepo.repo_name))
397 	    >= sizeof(irepo.repo_name))
398 		return got_error_msg(GOT_ERR_NO_SPACE, "repo name too long");
399 	if (strlcpy(irepo.repo_path, repo->path, sizeof(irepo.repo_path))
400 	    >= sizeof(irepo.repo_path))
401 		return got_error_msg(GOT_ERR_NO_SPACE, "repo path too long");
402 
403 	if (gotd_imsg_compose_event(iev, GOTD_IMSG_INFO_REPO, PROC_GOTD, -1,
404 	    &irepo, sizeof(irepo)) == -1) {
405 		err = got_error_from_errno("imsg compose INFO_REPO");
406 		if (err)
407 			return err;
408 	}
409 
410 	return NULL;
411 }
412 
413 static const struct got_error *
414 send_client_info(struct gotd_imsgev *iev, struct gotd_client *client)
415 {
416 	const struct got_error *err = NULL;
417 	struct gotd_imsg_info_client iclient;
418 	struct gotd_child_proc *proc;
419 
420 	memset(&iclient, 0, sizeof(iclient));
421 	iclient.euid = client->euid;
422 	iclient.egid = client->egid;
423 
424 	proc = client->repo;
425 	if (proc) {
426 		if (strlcpy(iclient.repo_name, proc->repo_path,
427 		    sizeof(iclient.repo_name)) >= sizeof(iclient.repo_name)) {
428 			return got_error_msg(GOT_ERR_NO_SPACE,
429 			    "repo name too long");
430 		}
431 		if (client_is_writing(client))
432 			iclient.is_writing = 1;
433 
434 		iclient.repo_child_pid = proc->pid;
435 	}
436 
437 	if (client->session)
438 		iclient.session_child_pid = client->session->pid;
439 
440 	if (gotd_imsg_compose_event(iev, GOTD_IMSG_INFO_CLIENT, PROC_GOTD, -1,
441 	    &iclient, sizeof(iclient)) == -1) {
442 		err = got_error_from_errno("imsg compose INFO_CLIENT");
443 		if (err)
444 			return err;
445 	}
446 
447 	return NULL;
448 }
449 
450 static const struct got_error *
451 send_info(struct gotd_client *client)
452 {
453 	const struct got_error *err = NULL;
454 	struct gotd_imsg_info info;
455 	uint64_t slot;
456 	struct gotd_repo *repo;
457 
458 	if (client->euid != 0)
459 		return got_error_set_errno(EPERM, "info");
460 
461 	info.pid = gotd.pid;
462 	info.verbosity = gotd.verbosity;
463 	info.nrepos = gotd.nrepos;
464 	info.nclients = client_cnt - 1;
465 
466 	if (gotd_imsg_compose_event(&client->iev, GOTD_IMSG_INFO, PROC_GOTD, -1,
467 	    &info, sizeof(info)) == -1) {
468 		err = got_error_from_errno("imsg compose INFO");
469 		if (err)
470 			return err;
471 	}
472 
473 	TAILQ_FOREACH(repo, &gotd.repos, entry) {
474 		err = send_repo_info(&client->iev, repo);
475 		if (err)
476 			return err;
477 	}
478 
479 	for (slot = 0; slot < nitems(gotd_clients); slot++) {
480 		struct gotd_client *c;
481 		STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
482 			if (c->id == client->id)
483 				continue;
484 			err = send_client_info(&client->iev, c);
485 			if (err)
486 				return err;
487 		}
488 	}
489 
490 	return NULL;
491 }
492 
493 static const struct got_error *
494 stop_gotd(struct gotd_client *client)
495 {
496 
497 	if (client->euid != 0)
498 		return got_error_set_errno(EPERM, "stop");
499 
500 	gotd_shutdown();
501 	/* NOTREACHED */
502 	return NULL;
503 }
504 
505 static const struct got_error *
506 start_client_authentication(struct gotd_client *client, struct imsg *imsg)
507 {
508 	const struct got_error *err;
509 	struct gotd_imsg_list_refs ireq;
510 	struct gotd_repo *repo = NULL;
511 	size_t datalen;
512 
513 	log_debug("list-refs request from uid %d", client->euid);
514 
515 	if (client->state != GOTD_CLIENT_STATE_NEW)
516 		return got_error_msg(GOT_ERR_BAD_REQUEST,
517 		    "unexpected list-refs request received");
518 
519 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
520 	if (datalen != sizeof(ireq))
521 		return got_error(GOT_ERR_PRIVSEP_LEN);
522 
523 	memcpy(&ireq, imsg->data, datalen);
524 
525 	if (ireq.client_is_reading) {
526 		err = ensure_client_is_not_writing(client);
527 		if (err)
528 			return err;
529 		repo = gotd_find_repo_by_name(ireq.repo_name, &gotd);
530 		if (repo == NULL)
531 			return got_error(GOT_ERR_NOT_GIT_REPO);
532 		err = start_auth_child(client, GOTD_AUTH_READ, repo,
533 		    gotd.argv0, gotd.confpath, gotd.daemonize,
534 		    gotd.verbosity);
535 		if (err)
536 			return err;
537 	} else {
538 		err = ensure_client_is_not_reading(client);
539 		if (err)
540 			return err;
541 		repo = gotd_find_repo_by_name(ireq.repo_name, &gotd);
542 		if (repo == NULL)
543 			return got_error(GOT_ERR_NOT_GIT_REPO);
544 		err = start_auth_child(client,
545 		    GOTD_AUTH_READ | GOTD_AUTH_WRITE,
546 		    repo, gotd.argv0, gotd.confpath, gotd.daemonize,
547 		    gotd.verbosity);
548 		if (err)
549 			return err;
550 	}
551 
552 	evtimer_add(&client->tmo, &auth_timeout);
553 
554 	/* Flow continues upon authentication successs/failure or timeout. */
555 	return NULL;
556 }
557 
558 static void
559 gotd_request(int fd, short events, void *arg)
560 {
561 	struct gotd_imsgev *iev = arg;
562 	struct imsgbuf *ibuf = &iev->ibuf;
563 	struct gotd_client *client = iev->handler_arg;
564 	const struct got_error *err = NULL;
565 	struct imsg imsg;
566 	ssize_t n;
567 
568 	if (events & EV_WRITE) {
569 		while (ibuf->w.queued) {
570 			n = msgbuf_write(&ibuf->w);
571 			if (n == -1 && errno == EPIPE) {
572 				/*
573 				 * The client has closed its socket.
574 				 * This can happen when Git clients are
575 				 * done sending pack file data.
576 				 */
577 				msgbuf_clear(&ibuf->w);
578 				continue;
579 			} else if (n == -1 && errno != EAGAIN) {
580 				err = got_error_from_errno("imsg_flush");
581 				disconnect_on_error(client, err);
582 				return;
583 			}
584 			if (n == 0) {
585 				/* Connection closed. */
586 				err = got_error(GOT_ERR_EOF);
587 				disconnect_on_error(client, err);
588 				return;
589 			}
590 		}
591 
592 		/* Disconnect gotctl(8) now that messages have been sent. */
593 		if (!client_is_reading(client) && !client_is_writing(client)) {
594 			disconnect(client);
595 			return;
596 		}
597 	}
598 
599 	if ((events & EV_READ) == 0)
600 		return;
601 
602 	memset(&imsg, 0, sizeof(imsg));
603 
604 	while (err == NULL) {
605 		err = gotd_imsg_recv(&imsg, ibuf, 0);
606 		if (err) {
607 			if (err->code == GOT_ERR_PRIVSEP_READ)
608 				err = NULL;
609 			break;
610 		}
611 
612 		evtimer_del(&client->tmo);
613 
614 		switch (imsg.hdr.type) {
615 		case GOTD_IMSG_INFO:
616 			err = send_info(client);
617 			break;
618 		case GOTD_IMSG_STOP:
619 			err = stop_gotd(client);
620 			break;
621 		case GOTD_IMSG_LIST_REFS:
622 			err = start_client_authentication(client, &imsg);
623 			break;
624 		default:
625 			log_debug("unexpected imsg %d", imsg.hdr.type);
626 			err = got_error(GOT_ERR_PRIVSEP_MSG);
627 			break;
628 		}
629 
630 		imsg_free(&imsg);
631 	}
632 
633 	if (err) {
634 		disconnect_on_error(client, err);
635 	} else {
636 		gotd_imsg_event_add(&client->iev);
637 	}
638 }
639 
640 static void
641 gotd_auth_timeout(int fd, short events, void *arg)
642 {
643 	struct gotd_client *client = arg;
644 
645 	log_debug("disconnecting uid %d due to authentication timeout",
646 	    client->euid);
647 	disconnect(client);
648 }
649 
650 static const struct got_error *
651 recv_connect(uint32_t *client_id, struct imsg *imsg)
652 {
653 	const struct got_error *err = NULL;
654 	struct gotd_imsg_connect iconnect;
655 	size_t datalen;
656 	int s = -1;
657 	struct gotd_client *client = NULL;
658 
659 	*client_id = 0;
660 
661 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
662 	if (datalen != sizeof(iconnect))
663 		return got_error(GOT_ERR_PRIVSEP_LEN);
664 	memcpy(&iconnect, imsg->data, sizeof(iconnect));
665 
666 	s = imsg->fd;
667 	if (s == -1) {
668 		err = got_error(GOT_ERR_PRIVSEP_NO_FD);
669 		goto done;
670 	}
671 
672 	if (find_client(iconnect.client_id)) {
673 		err = got_error_msg(GOT_ERR_CLIENT_ID, "duplicate client ID");
674 		goto done;
675 	}
676 
677 	client = calloc(1, sizeof(*client));
678 	if (client == NULL) {
679 		err = got_error_from_errno("calloc");
680 		goto done;
681 	}
682 
683 	*client_id = iconnect.client_id;
684 
685 	client->state = GOTD_CLIENT_STATE_NEW;
686 	client->id = iconnect.client_id;
687 	client->fd = s;
688 	s = -1;
689 	/* The auth process will verify UID/GID for us. */
690 	client->euid = iconnect.euid;
691 	client->egid = iconnect.egid;
692 
693 	imsg_init(&client->iev.ibuf, client->fd);
694 	client->iev.handler = gotd_request;
695 	client->iev.events = EV_READ;
696 	client->iev.handler_arg = client;
697 
698 	event_set(&client->iev.ev, client->fd, EV_READ, gotd_request,
699 	    &client->iev);
700 	gotd_imsg_event_add(&client->iev);
701 
702 	evtimer_set(&client->tmo, gotd_auth_timeout, client);
703 
704 	add_client(client);
705 	log_debug("%s: new client uid %d connected on fd %d", __func__,
706 	    client->euid, client->fd);
707 done:
708 	if (err) {
709 		struct gotd_child_proc *listen_proc = gotd.listen_proc;
710 		struct gotd_imsg_disconnect idisconnect;
711 
712 		idisconnect.client_id = client->id;
713 		if (gotd_imsg_compose_event(&listen_proc->iev,
714 		    GOTD_IMSG_DISCONNECT, PROC_GOTD, -1,
715 		    &idisconnect, sizeof(idisconnect)) == -1)
716 			log_warn("imsg compose DISCONNECT");
717 
718 		if (s != -1)
719 			close(s);
720 	}
721 
722 	return err;
723 }
724 
725 static const char *gotd_proc_names[PROC_MAX] = {
726 	"parent",
727 	"listen",
728 	"auth",
729 	"session_read",
730 	"session_write",
731 	"repo_read",
732 	"repo_write"
733 };
734 
735 static void
736 kill_proc(struct gotd_child_proc *proc, int fatal)
737 {
738 	struct timeval tv = { 5, 0 };
739 
740 	log_debug("kill -%d %d", fatal ? SIGKILL : SIGTERM, proc->pid);
741 
742 	if (proc->iev.ibuf.fd != -1) {
743 		event_del(&proc->iev.ev);
744 		msgbuf_clear(&proc->iev.ibuf.w);
745 		close(proc->iev.ibuf.fd);
746 		proc->iev.ibuf.fd = -1;
747 	}
748 
749 	if (!evtimer_pending(&proc->tmo, NULL) && !fatal)
750 		evtimer_add(&proc->tmo, &tv);
751 
752 	if (fatal) {
753 		log_warnx("sending SIGKILL to PID %d", proc->pid);
754 		kill(proc->pid, SIGKILL);
755 	} else
756 		kill(proc->pid, SIGTERM);
757 }
758 
759 static void
760 kill_proc_timeout(int fd, short ev, void *d)
761 {
762 	struct gotd_child_proc *proc = d;
763 
764 	log_warnx("timeout waiting for PID %d to terminate;"
765 	    " retrying with force", proc->pid);
766 	kill_proc(proc, 1);
767 }
768 
769 static void
770 gotd_shutdown(void)
771 {
772 	uint64_t slot;
773 
774 	log_debug("shutting down");
775 	for (slot = 0; slot < nitems(gotd_clients); slot++) {
776 		struct gotd_client *c, *tmp;
777 
778 		STAILQ_FOREACH_SAFE(c, &gotd_clients[slot], entry, tmp)
779 			disconnect(c);
780 	}
781 
782 	kill_proc(gotd.listen_proc, 0);
783 
784 	log_info("terminating");
785 	exit(0);
786 }
787 
788 static struct gotd_child_proc *
789 find_proc_by_pid(pid_t pid)
790 {
791 	struct gotd_child_proc *proc = NULL;
792 
793 	TAILQ_FOREACH(proc, &procs, entry)
794 		if (proc->pid == pid)
795 			break;
796 
797 	return proc;
798 }
799 
800 void
801 gotd_sighdlr(int sig, short event, void *arg)
802 {
803 	struct gotd_child_proc *proc;
804 	pid_t pid;
805 	int status;
806 
807 	/*
808 	 * Normal signal handler rules don't apply because libevent
809 	 * decouples for us.
810 	 */
811 
812 	switch (sig) {
813 	case SIGHUP:
814 		log_info("%s: ignoring SIGHUP", __func__);
815 		break;
816 	case SIGUSR1:
817 		log_info("%s: ignoring SIGUSR1", __func__);
818 		break;
819 	case SIGTERM:
820 	case SIGINT:
821 		gotd_shutdown();
822 		break;
823 	case SIGCHLD:
824 		for (;;) {
825 			pid = waitpid(WAIT_ANY, &status, WNOHANG);
826 			if (pid == -1) {
827 				if (errno == EINTR)
828 					continue;
829 				if (errno == ECHILD)
830 					break;
831 				fatal("waitpid");
832 			}
833 			if (pid == 0)
834 				break;
835 
836 			log_debug("reaped pid %d", pid);
837 			proc = find_proc_by_pid(pid);
838 			if (proc == NULL) {
839 				log_info("caught exit of unknown child %d",
840 				    pid);
841 				continue;
842 			}
843 
844 			if (WIFSIGNALED(status)) {
845 				log_warnx("child PID %d terminated with"
846 				    " signal %d", pid, WTERMSIG(status));
847 			}
848 
849 			proc_done(proc);
850 		}
851 		break;
852 	default:
853 		fatalx("unexpected signal");
854 	}
855 }
856 
857 static const struct got_error *
858 ensure_proc_is_reading(struct gotd_client *client,
859     struct gotd_child_proc *proc)
860 {
861 	if (!client_is_reading(client)) {
862 		kill_proc(proc, 1);
863 		return got_error_fmt(GOT_ERR_BAD_PACKET,
864 		    "PID %d handled a read-request for uid %d but this "
865 		    "user is not reading from a repository", proc->pid,
866 		    client->euid);
867 	}
868 
869 	return NULL;
870 }
871 
872 static const struct got_error *
873 ensure_proc_is_writing(struct gotd_client *client,
874     struct gotd_child_proc *proc)
875 {
876 	if (!client_is_writing(client)) {
877 		kill_proc(proc, 1);
878 		return got_error_fmt(GOT_ERR_BAD_PACKET,
879 		    "PID %d handled a write-request for uid %d but this "
880 		    "user is not writing to a repository", proc->pid,
881 		    client->euid);
882 	}
883 
884 	return NULL;
885 }
886 
887 static int
888 verify_imsg_src(struct gotd_client *client, struct gotd_child_proc *proc,
889     struct imsg *imsg)
890 {
891 	const struct got_error *err;
892 	int ret = 0;
893 
894 	if (proc->type == PROC_REPO_READ || proc->type == PROC_REPO_WRITE) {
895 		if (client->repo == NULL)
896 			fatalx("no process found for uid %d", client->euid);
897 		if (proc->pid != client->repo->pid) {
898 			kill_proc(proc, 1);
899 			log_warnx("received message from PID %d for uid %d, "
900 			    "while PID %d is the process serving this user",
901 			    proc->pid, client->euid, client->repo->pid);
902 			return 0;
903 		}
904 	}
905 	if (proc->type == PROC_SESSION_READ ||
906 	    proc->type == PROC_SESSION_WRITE) {
907 		if (client->session == NULL) {
908 			log_warnx("no session found for uid %d", client->euid);
909 			return 0;
910 		}
911 		if (proc->pid != client->session->pid) {
912 			kill_proc(proc, 1);
913 			log_warnx("received message from PID %d for uid %d, "
914 			    "while PID %d is the process serving this user",
915 			    proc->pid, client->euid, client->session->pid);
916 			return 0;
917 		}
918 	}
919 
920 	switch (imsg->hdr.type) {
921 	case GOTD_IMSG_ERROR:
922 		ret = 1;
923 		break;
924 	case GOTD_IMSG_CONNECT:
925 		if (proc->type != PROC_LISTEN) {
926 			err = got_error_fmt(GOT_ERR_BAD_PACKET,
927 			    "new connection for uid %d from PID %d "
928 			    "which is not the listen process",
929 			    proc->pid, client->euid);
930 		} else
931 			ret = 1;
932 		break;
933 	case GOTD_IMSG_ACCESS_GRANTED:
934 		if (proc->type != PROC_AUTH) {
935 			err = got_error_fmt(GOT_ERR_BAD_PACKET,
936 			    "authentication of uid %d from PID %d "
937 			    "which is not the auth process",
938 			    proc->pid, client->euid);
939 		} else
940 			ret = 1;
941 		break;
942 	case GOTD_IMSG_CLIENT_SESSION_READY:
943 		if (proc->type != PROC_SESSION_READ &&
944 		    proc->type != PROC_SESSION_WRITE) {
945 			err = got_error_fmt(GOT_ERR_BAD_PACKET,
946 			    "unexpected \"ready\" signal from PID %d",
947 			    proc->pid);
948 		} else
949 			ret = 1;
950 		break;
951 	case GOTD_IMSG_REPO_CHILD_READY:
952 		if (proc->type != PROC_REPO_READ &&
953 		    proc->type != PROC_REPO_WRITE) {
954 			err = got_error_fmt(GOT_ERR_BAD_PACKET,
955 			    "unexpected \"ready\" signal from PID %d",
956 			    proc->pid);
957 		} else
958 			ret = 1;
959 		break;
960 	case GOTD_IMSG_PACKFILE_DONE:
961 		err = ensure_proc_is_reading(client, proc);
962 		if (err)
963 			log_warnx("uid %d: %s", client->euid, err->msg);
964 		else
965 			ret = 1;
966 		break;
967 	case GOTD_IMSG_PACKFILE_INSTALL:
968 	case GOTD_IMSG_REF_UPDATES_START:
969 	case GOTD_IMSG_REF_UPDATE:
970 		err = ensure_proc_is_writing(client, proc);
971 		if (err)
972 			log_warnx("uid %d: %s", client->euid, err->msg);
973 		else
974 			ret = 1;
975 		break;
976 	default:
977 		log_debug("%s: unexpected imsg %d", __func__, imsg->hdr.type);
978 		break;
979 	}
980 
981 	return ret;
982 }
983 
984 static const struct got_error *
985 connect_repo_child(struct gotd_client *client,
986     struct gotd_child_proc *repo_proc)
987 {
988 	static const struct got_error *err;
989 	struct gotd_imsgev *session_iev = &client->session->iev;
990 	struct gotd_imsg_connect_repo_child ireq;
991 	int pipe[2];
992 
993 	if (client->state != GOTD_CLIENT_STATE_ACCESS_GRANTED)
994 		return got_error_msg(GOT_ERR_BAD_REQUEST,
995 		    "unexpected repo child ready signal received");
996 
997 	if (socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK,
998 	    PF_UNSPEC, pipe) == -1)
999 		fatal("socketpair");
1000 
1001 	memset(&ireq, 0, sizeof(ireq));
1002 	ireq.client_id = client->id;
1003 	ireq.proc_id = repo_proc->type;
1004 
1005 	/* Pass repo child pipe to session child process. */
1006 	if (gotd_imsg_compose_event(session_iev, GOTD_IMSG_CONNECT_REPO_CHILD,
1007 	    PROC_GOTD, pipe[0], &ireq, sizeof(ireq)) == -1) {
1008 		err = got_error_from_errno("imsg compose CONNECT_REPO_CHILD");
1009 		close(pipe[0]);
1010 		close(pipe[1]);
1011 		return err;
1012 	}
1013 
1014 	/* Pass session child pipe to repo child process. */
1015 	if (gotd_imsg_compose_event(&repo_proc->iev,
1016 	    GOTD_IMSG_CONNECT_REPO_CHILD, PROC_GOTD, pipe[1], NULL, 0) == -1) {
1017 		err = got_error_from_errno("imsg compose CONNECT_REPO_CHILD");
1018 		close(pipe[1]);
1019 		return err;
1020 	}
1021 
1022 	return NULL;
1023 }
1024 
1025 static void
1026 gotd_dispatch_listener(int fd, short event, void *arg)
1027 {
1028 	struct gotd_imsgev *iev = arg;
1029 	struct imsgbuf *ibuf = &iev->ibuf;
1030 	struct gotd_child_proc *proc = gotd.listen_proc;
1031 	ssize_t n;
1032 	int shut = 0;
1033 	struct imsg imsg;
1034 
1035 	if (proc->iev.ibuf.fd != fd)
1036 		fatalx("%s: unexpected fd %d", __func__, fd);
1037 
1038 	if (event & EV_READ) {
1039 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1040 			fatal("imsg_read error");
1041 		if (n == 0) {
1042 			/* Connection closed. */
1043 			shut = 1;
1044 			goto done;
1045 		}
1046 	}
1047 
1048 	if (event & EV_WRITE) {
1049 		n = msgbuf_write(&ibuf->w);
1050 		if (n == -1 && errno != EAGAIN)
1051 			fatal("msgbuf_write");
1052 		if (n == 0) {
1053 			/* Connection closed. */
1054 			shut = 1;
1055 			goto done;
1056 		}
1057 	}
1058 
1059 	for (;;) {
1060 		const struct got_error *err = NULL;
1061 		struct gotd_client *client = NULL;
1062 		uint32_t client_id = 0;
1063 		int do_disconnect = 0;
1064 
1065 		if ((n = imsg_get(ibuf, &imsg)) == -1)
1066 			fatal("%s: imsg_get error", __func__);
1067 		if (n == 0)	/* No more messages. */
1068 			break;
1069 
1070 		switch (imsg.hdr.type) {
1071 		case GOTD_IMSG_ERROR:
1072 			do_disconnect = 1;
1073 			err = gotd_imsg_recv_error(&client_id, &imsg);
1074 			break;
1075 		case GOTD_IMSG_CONNECT:
1076 			err = recv_connect(&client_id, &imsg);
1077 			break;
1078 		default:
1079 			log_debug("unexpected imsg %d", imsg.hdr.type);
1080 			break;
1081 		}
1082 
1083 		client = find_client(client_id);
1084 		if (client == NULL) {
1085 			log_warnx("%s: client not found", __func__);
1086 			imsg_free(&imsg);
1087 			continue;
1088 		}
1089 
1090 		if (err)
1091 			log_warnx("uid %d: %s", client->euid, err->msg);
1092 
1093 		if (do_disconnect) {
1094 			if (err)
1095 				disconnect_on_error(client, err);
1096 			else
1097 				disconnect(client);
1098 		}
1099 
1100 		imsg_free(&imsg);
1101 	}
1102 done:
1103 	if (!shut) {
1104 		gotd_imsg_event_add(iev);
1105 	} else {
1106 		/* This pipe is dead. Remove its event handler */
1107 		event_del(&iev->ev);
1108 		event_loopexit(NULL);
1109 	}
1110 }
1111 
1112 static void
1113 gotd_dispatch_auth_child(int fd, short event, void *arg)
1114 {
1115 	const struct got_error *err = NULL;
1116 	struct gotd_imsgev *iev = arg;
1117 	struct imsgbuf *ibuf = &iev->ibuf;
1118 	struct gotd_client *client;
1119 	struct gotd_repo *repo = NULL;
1120 	ssize_t n;
1121 	int shut = 0;
1122 	struct imsg imsg;
1123 	uint32_t client_id = 0;
1124 	int do_disconnect = 0;
1125 
1126 	client = find_client_by_proc_fd(fd);
1127 	if (client == NULL) {
1128 		/* Can happen during process teardown. */
1129 		warnx("cannot find client for fd %d", fd);
1130 		shut = 1;
1131 		goto done;
1132 	}
1133 
1134 	if (client->auth == NULL)
1135 		fatalx("cannot find auth child process for fd %d", fd);
1136 
1137 	if (event & EV_READ) {
1138 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1139 			fatal("imsg_read error");
1140 		if (n == 0) {
1141 			/* Connection closed. */
1142 			shut = 1;
1143 			goto done;
1144 		}
1145 	}
1146 
1147 	if (event & EV_WRITE) {
1148 		n = msgbuf_write(&ibuf->w);
1149 		if (n == -1 && errno != EAGAIN)
1150 			fatal("msgbuf_write");
1151 		if (n == 0) {
1152 			/* Connection closed. */
1153 			shut = 1;
1154 		}
1155 		goto done;
1156 	}
1157 
1158 	if (client->auth->iev.ibuf.fd != fd)
1159 		fatalx("%s: unexpected fd %d", __func__, fd);
1160 
1161 	if ((n = imsg_get(ibuf, &imsg)) == -1)
1162 		fatal("%s: imsg_get error", __func__);
1163 	if (n == 0)	/* No more messages. */
1164 		return;
1165 
1166 	evtimer_del(&client->tmo);
1167 
1168 	switch (imsg.hdr.type) {
1169 	case GOTD_IMSG_ERROR:
1170 		do_disconnect = 1;
1171 		err = gotd_imsg_recv_error(&client_id, &imsg);
1172 		break;
1173 	case GOTD_IMSG_ACCESS_GRANTED:
1174 		client->state = GOTD_CLIENT_STATE_ACCESS_GRANTED;
1175 		break;
1176 	default:
1177 		do_disconnect = 1;
1178 		log_debug("unexpected imsg %d", imsg.hdr.type);
1179 		break;
1180 	}
1181 
1182 	if (!verify_imsg_src(client, client->auth, &imsg)) {
1183 		do_disconnect = 1;
1184 		log_debug("dropping imsg type %d from PID %d",
1185 		    imsg.hdr.type, client->auth->pid);
1186 	}
1187 	imsg_free(&imsg);
1188 
1189 	if (do_disconnect) {
1190 		if (err)
1191 			disconnect_on_error(client, err);
1192 		else
1193 			disconnect(client);
1194 		return;
1195 	}
1196 
1197 	repo = gotd_find_repo_by_name(client->auth->repo_name, &gotd);
1198 	if (repo == NULL) {
1199 		err = got_error(GOT_ERR_NOT_GIT_REPO);
1200 		goto done;
1201 	}
1202 	kill_auth_proc(client);
1203 
1204 	log_info("authenticated uid %d for repository %s",
1205 	    client->euid, repo->name);
1206 
1207 	err = start_session_child(client, repo, gotd.argv0,
1208 	    gotd.confpath, gotd.daemonize, gotd.verbosity);
1209 	if (err)
1210 		goto done;
1211 done:
1212 	if (err)
1213 		log_warnx("uid %d: %s", client->euid, err->msg);
1214 
1215 	/* We might have killed the auth process by now. */
1216 	if (client->auth != NULL) {
1217 		if (!shut) {
1218 			gotd_imsg_event_add(iev);
1219 		} else {
1220 			/* This pipe is dead. Remove its event handler */
1221 			event_del(&iev->ev);
1222 		}
1223 	}
1224 }
1225 
1226 static const struct got_error *
1227 connect_session(struct gotd_client *client)
1228 {
1229 	const struct got_error *err = NULL;
1230 	struct gotd_imsg_connect iconnect;
1231 	int s;
1232 
1233 	memset(&iconnect, 0, sizeof(iconnect));
1234 
1235 	s = dup(client->fd);
1236 	if (s == -1)
1237 		return got_error_from_errno("dup");
1238 
1239 	iconnect.client_id = client->id;
1240 	iconnect.euid = client->euid;
1241 	iconnect.egid = client->egid;
1242 
1243 	if (gotd_imsg_compose_event(&client->session->iev, GOTD_IMSG_CONNECT,
1244 	    PROC_GOTD, s, &iconnect, sizeof(iconnect)) == -1) {
1245 		err = got_error_from_errno("imsg compose CONNECT");
1246 		close(s);
1247 		return err;
1248 	}
1249 
1250 	/*
1251 	 * We are no longer interested in messages from this client.
1252 	 * Further client requests will be handled by the session process.
1253 	 */
1254 	msgbuf_clear(&client->iev.ibuf.w);
1255 	imsg_clear(&client->iev.ibuf);
1256 	event_del(&client->iev.ev);
1257 	client->fd = -1; /* will be closed via copy in client->iev.ibuf.fd */
1258 
1259 	return NULL;
1260 }
1261 
1262 static void
1263 gotd_dispatch_client_session(int fd, short event, void *arg)
1264 {
1265 	struct gotd_imsgev *iev = arg;
1266 	struct imsgbuf *ibuf = &iev->ibuf;
1267 	struct gotd_child_proc *proc = NULL;
1268 	struct gotd_client *client = NULL;
1269 	ssize_t n;
1270 	int shut = 0;
1271 	struct imsg imsg;
1272 
1273 	client = find_client_by_proc_fd(fd);
1274 	if (client == NULL) {
1275 		/* Can happen during process teardown. */
1276 		warnx("cannot find client for fd %d", fd);
1277 		shut = 1;
1278 		goto done;
1279 	}
1280 
1281 	if (event & EV_READ) {
1282 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1283 			fatal("imsg_read error");
1284 		if (n == 0) {
1285 			/* Connection closed. */
1286 			shut = 1;
1287 			goto done;
1288 		}
1289 	}
1290 
1291 	if (event & EV_WRITE) {
1292 		n = msgbuf_write(&ibuf->w);
1293 		if (n == -1 && errno != EAGAIN)
1294 			fatal("msgbuf_write");
1295 		if (n == 0) {
1296 			/* Connection closed. */
1297 			shut = 1;
1298 			goto done;
1299 		}
1300 	}
1301 
1302 	proc = client->session;
1303 	if (proc == NULL)
1304 		fatalx("cannot find session child process for fd %d", fd);
1305 
1306 	for (;;) {
1307 		const struct got_error *err = NULL;
1308 		uint32_t client_id = 0;
1309 		int do_disconnect = 0, do_start_repo_child = 0;
1310 
1311 		if ((n = imsg_get(ibuf, &imsg)) == -1)
1312 			fatal("%s: imsg_get error", __func__);
1313 		if (n == 0)	/* No more messages. */
1314 			break;
1315 
1316 		switch (imsg.hdr.type) {
1317 		case GOTD_IMSG_ERROR:
1318 			do_disconnect = 1;
1319 			err = gotd_imsg_recv_error(&client_id, &imsg);
1320 			break;
1321 		case GOTD_IMSG_CLIENT_SESSION_READY:
1322 			if (client->state != GOTD_CLIENT_STATE_ACCESS_GRANTED) {
1323 				err = got_error(GOT_ERR_PRIVSEP_MSG);
1324 				break;
1325 			}
1326 			do_start_repo_child = 1;
1327 			break;
1328 		case GOTD_IMSG_DISCONNECT:
1329 			do_disconnect = 1;
1330 			break;
1331 		default:
1332 			log_debug("unexpected imsg %d", imsg.hdr.type);
1333 			break;
1334 		}
1335 
1336 		if (!verify_imsg_src(client, proc, &imsg)) {
1337 			log_debug("dropping imsg type %d from PID %d",
1338 			    imsg.hdr.type, proc->pid);
1339 			imsg_free(&imsg);
1340 			continue;
1341 		}
1342 		if (err)
1343 			log_warnx("uid %d: %s", client->euid, err->msg);
1344 
1345 		if (do_start_repo_child) {
1346 			struct gotd_repo *repo;
1347 			const char *name = client->session->repo_name;
1348 
1349 			repo = gotd_find_repo_by_name(name, &gotd);
1350 			if (repo != NULL) {
1351 				enum gotd_procid proc_type;
1352 
1353 				if (client->required_auth & GOTD_AUTH_WRITE)
1354 					proc_type = PROC_REPO_WRITE;
1355 				else
1356 					proc_type = PROC_REPO_READ;
1357 
1358 				err = start_repo_child(client, proc_type, repo,
1359 				    gotd.argv0, gotd.confpath, gotd.daemonize,
1360 				    gotd.verbosity);
1361 			} else
1362 				err = got_error(GOT_ERR_NOT_GIT_REPO);
1363 
1364 			if (err) {
1365 				log_warnx("uid %d: %s", client->euid, err->msg);
1366 				do_disconnect = 1;
1367 			}
1368 		}
1369 
1370 		if (do_disconnect) {
1371 			if (err)
1372 				disconnect_on_error(client, err);
1373 			else
1374 				disconnect(client);
1375 		}
1376 
1377 		imsg_free(&imsg);
1378 	}
1379 done:
1380 	if (!shut) {
1381 		gotd_imsg_event_add(iev);
1382 	} else {
1383 		/* This pipe is dead. Remove its event handler */
1384 		event_del(&iev->ev);
1385 		disconnect(client);
1386 	}
1387 }
1388 
1389 static void
1390 gotd_dispatch_repo_child(int fd, short event, void *arg)
1391 {
1392 	struct gotd_imsgev *iev = arg;
1393 	struct imsgbuf *ibuf = &iev->ibuf;
1394 	struct gotd_child_proc *proc = NULL;
1395 	struct gotd_client *client;
1396 	ssize_t n;
1397 	int shut = 0;
1398 	struct imsg imsg;
1399 
1400 	client = find_client_by_proc_fd(fd);
1401 	if (client == NULL) {
1402 		/* Can happen during process teardown. */
1403 		warnx("cannot find client for fd %d", fd);
1404 		shut = 1;
1405 		goto done;
1406 	}
1407 
1408 	if (event & EV_READ) {
1409 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1410 			fatal("imsg_read error");
1411 		if (n == 0) {
1412 			/* Connection closed. */
1413 			shut = 1;
1414 			goto done;
1415 		}
1416 	}
1417 
1418 	if (event & EV_WRITE) {
1419 		n = msgbuf_write(&ibuf->w);
1420 		if (n == -1 && errno != EAGAIN)
1421 			fatal("msgbuf_write");
1422 		if (n == 0) {
1423 			/* Connection closed. */
1424 			shut = 1;
1425 			goto done;
1426 		}
1427 	}
1428 
1429 	proc = client->repo;
1430 	if (proc == NULL)
1431 		fatalx("cannot find child process for fd %d", fd);
1432 
1433 	for (;;) {
1434 		const struct got_error *err = NULL;
1435 		uint32_t client_id = 0;
1436 		int do_disconnect = 0;
1437 
1438 		if ((n = imsg_get(ibuf, &imsg)) == -1)
1439 			fatal("%s: imsg_get error", __func__);
1440 		if (n == 0)	/* No more messages. */
1441 			break;
1442 
1443 		switch (imsg.hdr.type) {
1444 		case GOTD_IMSG_ERROR:
1445 			do_disconnect = 1;
1446 			err = gotd_imsg_recv_error(&client_id, &imsg);
1447 			break;
1448 		case GOTD_IMSG_REPO_CHILD_READY:
1449 			err = connect_session(client);
1450 			if (err)
1451 				break;
1452 			err = connect_repo_child(client, proc);
1453 			break;
1454 		default:
1455 			log_debug("unexpected imsg %d", imsg.hdr.type);
1456 			break;
1457 		}
1458 
1459 		if (!verify_imsg_src(client, proc, &imsg)) {
1460 			log_debug("dropping imsg type %d from PID %d",
1461 			    imsg.hdr.type, proc->pid);
1462 			imsg_free(&imsg);
1463 			continue;
1464 		}
1465 		if (err)
1466 			log_warnx("uid %d: %s", client->euid, err->msg);
1467 
1468 		if (do_disconnect) {
1469 			if (err)
1470 				disconnect_on_error(client, err);
1471 			else
1472 				disconnect(client);
1473 		}
1474 
1475 		imsg_free(&imsg);
1476 	}
1477 done:
1478 	if (!shut) {
1479 		gotd_imsg_event_add(iev);
1480 	} else {
1481 		/* This pipe is dead. Remove its event handler */
1482 		event_del(&iev->ev);
1483 		disconnect(client);
1484 	}
1485 }
1486 
1487 static pid_t
1488 start_child(enum gotd_procid proc_id, const char *repo_path,
1489     char *argv0, const char *confpath, int fd, int daemonize, int verbosity)
1490 {
1491 	char	*argv[11];
1492 	int	 argc = 0;
1493 	pid_t	 pid;
1494 
1495 	switch (pid = fork()) {
1496 	case -1:
1497 		fatal("cannot fork");
1498 	case 0:
1499 		break;
1500 	default:
1501 		close(fd);
1502 		return pid;
1503 	}
1504 
1505 	if (fd != GOTD_FILENO_MSG_PIPE) {
1506 		if (dup2(fd, GOTD_FILENO_MSG_PIPE) == -1)
1507 			fatal("cannot setup imsg fd");
1508 	} else if (fcntl(fd, F_SETFD, 0) == -1)
1509 		fatal("cannot setup imsg fd");
1510 
1511 	argv[argc++] = argv0;
1512 	switch (proc_id) {
1513 	case PROC_LISTEN:
1514 		argv[argc++] = (char *)"-L";
1515 		break;
1516 	case PROC_AUTH:
1517 		argv[argc++] = (char *)"-A";
1518 		break;
1519 	case PROC_SESSION_READ:
1520 		argv[argc++] = (char *)"-s";
1521 		break;
1522 	case PROC_SESSION_WRITE:
1523 		argv[argc++] = (char *)"-S";
1524 		break;
1525 	case PROC_REPO_READ:
1526 		argv[argc++] = (char *)"-R";
1527 		break;
1528 	case PROC_REPO_WRITE:
1529 		argv[argc++] = (char *)"-W";
1530 		break;
1531 	default:
1532 		fatalx("invalid process id %d", proc_id);
1533 	}
1534 
1535 	argv[argc++] = (char *)"-f";
1536 	argv[argc++] = (char *)confpath;
1537 
1538 	if (repo_path) {
1539 		argv[argc++] = (char *)"-P";
1540 		argv[argc++] = (char *)repo_path;
1541 	}
1542 
1543 	if (!daemonize)
1544 		argv[argc++] = (char *)"-d";
1545 	if (verbosity > 0)
1546 		argv[argc++] = (char *)"-v";
1547 	if (verbosity > 1)
1548 		argv[argc++] = (char *)"-v";
1549 	argv[argc++] = NULL;
1550 
1551 	execvp(argv0, argv);
1552 	fatal("execvp");
1553 }
1554 
1555 static void
1556 start_listener(char *argv0, const char *confpath, int daemonize, int verbosity)
1557 {
1558 	struct gotd_child_proc *proc;
1559 
1560 	proc = calloc(1, sizeof(*proc));
1561 	if (proc == NULL)
1562 		fatal("calloc");
1563 
1564 	TAILQ_INSERT_HEAD(&procs, proc, entry);
1565 
1566 	/* proc->tmo is initialized in main() after event_init() */
1567 
1568 	proc->type = PROC_LISTEN;
1569 
1570 	if (socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK,
1571 	    PF_UNSPEC, proc->pipe) == -1)
1572 		fatal("socketpair");
1573 
1574 	proc->pid = start_child(proc->type, NULL, argv0, confpath,
1575 	    proc->pipe[1], daemonize, verbosity);
1576 	imsg_init(&proc->iev.ibuf, proc->pipe[0]);
1577 	proc->iev.handler = gotd_dispatch_listener;
1578 	proc->iev.events = EV_READ;
1579 	proc->iev.handler_arg = NULL;
1580 
1581 	gotd.listen_proc = proc;
1582 }
1583 
1584 static const struct got_error *
1585 start_session_child(struct gotd_client *client, struct gotd_repo *repo,
1586     char *argv0, const char *confpath, int daemonize, int verbosity)
1587 {
1588 	struct gotd_child_proc *proc;
1589 
1590 	proc = calloc(1, sizeof(*proc));
1591 	if (proc == NULL)
1592 		return got_error_from_errno("calloc");
1593 
1594 	TAILQ_INSERT_HEAD(&procs, proc, entry);
1595 	evtimer_set(&proc->tmo, kill_proc_timeout, proc);
1596 
1597 	if (client_is_reading(client))
1598 		proc->type = PROC_SESSION_READ;
1599 	else
1600 		proc->type = PROC_SESSION_WRITE;
1601 	if (strlcpy(proc->repo_name, repo->name,
1602 	    sizeof(proc->repo_name)) >= sizeof(proc->repo_name))
1603 		fatalx("repository name too long: %s", repo->name);
1604 	log_debug("starting client uid %d session for repository %s",
1605 	    client->euid, repo->name);
1606 	if (strlcpy(proc->repo_path, repo->path, sizeof(proc->repo_path)) >=
1607 	    sizeof(proc->repo_path))
1608 		fatalx("repository path too long: %s", repo->path);
1609 	if (socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK,
1610 	    PF_UNSPEC, proc->pipe) == -1)
1611 		fatal("socketpair");
1612 	proc->pid = start_child(proc->type, proc->repo_path, argv0,
1613 	    confpath, proc->pipe[1], daemonize, verbosity);
1614 	imsg_init(&proc->iev.ibuf, proc->pipe[0]);
1615 	log_debug("proc %s %s is on fd %d",
1616 	    gotd_proc_names[proc->type], proc->repo_path,
1617 	    proc->pipe[0]);
1618 	proc->iev.handler = gotd_dispatch_client_session;
1619 	proc->iev.events = EV_READ;
1620 	proc->iev.handler_arg = NULL;
1621 	event_set(&proc->iev.ev, proc->iev.ibuf.fd, EV_READ,
1622 	    gotd_dispatch_client_session, &proc->iev);
1623 	gotd_imsg_event_add(&proc->iev);
1624 
1625 	client->session = proc;
1626 	return NULL;
1627 }
1628 
1629 static const struct got_error *
1630 start_repo_child(struct gotd_client *client, enum gotd_procid proc_type,
1631     struct gotd_repo *repo, char *argv0, const char *confpath,
1632     int daemonize, int verbosity)
1633 {
1634 	struct gotd_child_proc *proc;
1635 
1636 	if (proc_type != PROC_REPO_READ && proc_type != PROC_REPO_WRITE)
1637 		return got_error_msg(GOT_ERR_NOT_IMPL, "bad process type");
1638 
1639 	proc = calloc(1, sizeof(*proc));
1640 	if (proc == NULL)
1641 		return got_error_from_errno("calloc");
1642 
1643 	TAILQ_INSERT_HEAD(&procs, proc, entry);
1644 	evtimer_set(&proc->tmo, kill_proc_timeout, proc);
1645 
1646 	proc->type = proc_type;
1647 	if (strlcpy(proc->repo_name, repo->name,
1648 	    sizeof(proc->repo_name)) >= sizeof(proc->repo_name))
1649 		fatalx("repository name too long: %s", repo->name);
1650 	log_debug("starting %s for repository %s",
1651 	    proc->type == PROC_REPO_READ ? "reader" : "writer", repo->name);
1652 	if (strlcpy(proc->repo_path, repo->path, sizeof(proc->repo_path)) >=
1653 	    sizeof(proc->repo_path))
1654 		fatalx("repository path too long: %s", repo->path);
1655 	if (socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK,
1656 	    PF_UNSPEC, proc->pipe) == -1)
1657 		fatal("socketpair");
1658 	proc->pid = start_child(proc->type, proc->repo_path, argv0,
1659 	    confpath, proc->pipe[1], daemonize, verbosity);
1660 	imsg_init(&proc->iev.ibuf, proc->pipe[0]);
1661 	log_debug("proc %s %s is on fd %d",
1662 	    gotd_proc_names[proc->type], proc->repo_path,
1663 	    proc->pipe[0]);
1664 	proc->iev.handler = gotd_dispatch_repo_child;
1665 	proc->iev.events = EV_READ;
1666 	proc->iev.handler_arg = NULL;
1667 	event_set(&proc->iev.ev, proc->iev.ibuf.fd, EV_READ,
1668 	    gotd_dispatch_repo_child, &proc->iev);
1669 	gotd_imsg_event_add(&proc->iev);
1670 
1671 	client->repo = proc;
1672 	return NULL;
1673 }
1674 
1675 static const struct got_error *
1676 start_auth_child(struct gotd_client *client, int required_auth,
1677     struct gotd_repo *repo, char *argv0, const char *confpath,
1678     int daemonize, int verbosity)
1679 {
1680 	const struct got_error *err = NULL;
1681 	struct gotd_child_proc *proc;
1682 	struct gotd_imsg_auth iauth;
1683 	int fd;
1684 
1685 	memset(&iauth, 0, sizeof(iauth));
1686 
1687 	fd = dup(client->fd);
1688 	if (fd == -1)
1689 		return got_error_from_errno("dup");
1690 
1691 	proc = calloc(1, sizeof(*proc));
1692 	if (proc == NULL) {
1693 		err = got_error_from_errno("calloc");
1694 		close(fd);
1695 		return err;
1696 	}
1697 
1698 	TAILQ_INSERT_HEAD(&procs, proc, entry);
1699 	evtimer_set(&proc->tmo, kill_proc_timeout, proc);
1700 
1701 	proc->type = PROC_AUTH;
1702 	if (strlcpy(proc->repo_name, repo->name,
1703 	    sizeof(proc->repo_name)) >= sizeof(proc->repo_name))
1704 		fatalx("repository name too long: %s", repo->name);
1705 	log_debug("starting auth for uid %d repository %s",
1706 	    client->euid, repo->name);
1707 	if (strlcpy(proc->repo_path, repo->path, sizeof(proc->repo_path)) >=
1708 	    sizeof(proc->repo_path))
1709 		fatalx("repository path too long: %s", repo->path);
1710 	if (socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK,
1711 	    PF_UNSPEC, proc->pipe) == -1)
1712 		fatal("socketpair");
1713 	proc->pid = start_child(proc->type, proc->repo_path, argv0,
1714 	    confpath, proc->pipe[1], daemonize, verbosity);
1715 	imsg_init(&proc->iev.ibuf, proc->pipe[0]);
1716 	log_debug("proc %s %s is on fd %d",
1717 	    gotd_proc_names[proc->type], proc->repo_path,
1718 	    proc->pipe[0]);
1719 	proc->iev.handler = gotd_dispatch_auth_child;
1720 	proc->iev.events = EV_READ;
1721 	proc->iev.handler_arg = NULL;
1722 	event_set(&proc->iev.ev, proc->iev.ibuf.fd, EV_READ,
1723 	    gotd_dispatch_auth_child, &proc->iev);
1724 	gotd_imsg_event_add(&proc->iev);
1725 
1726 	iauth.euid = client->euid;
1727 	iauth.egid = client->egid;
1728 	iauth.required_auth = required_auth;
1729 	iauth.client_id = client->id;
1730 	if (gotd_imsg_compose_event(&proc->iev, GOTD_IMSG_AUTHENTICATE,
1731 	    PROC_GOTD, fd, &iauth, sizeof(iauth)) == -1) {
1732 		log_warn("imsg compose AUTHENTICATE");
1733 		close(fd);
1734 		/* Let the auth_timeout handler tidy up. */
1735 	}
1736 
1737 	client->auth = proc;
1738 	client->required_auth = required_auth;
1739 	return NULL;
1740 }
1741 
1742 static void
1743 apply_unveil_repo_readonly(const char *repo_path, int need_tmpdir)
1744 {
1745 	if (need_tmpdir) {
1746 		if (unveil(GOT_TMPDIR_STR, "rwc") == -1)
1747 			fatal("unveil %s", GOT_TMPDIR_STR);
1748 	}
1749 
1750 	if (unveil(repo_path, "r") == -1)
1751 		fatal("unveil %s", repo_path);
1752 
1753 	if (unveil(NULL, NULL) == -1)
1754 		fatal("unveil");
1755 }
1756 
1757 static void
1758 apply_unveil_repo_readwrite(const char *repo_path)
1759 {
1760 	if (unveil(repo_path, "rwc") == -1)
1761 		fatal("unveil %s", repo_path);
1762 
1763 	if (unveil(GOT_TMPDIR_STR, "rwc") == -1)
1764 		fatal("unveil %s", GOT_TMPDIR_STR);
1765 
1766 	if (unveil(NULL, NULL) == -1)
1767 		fatal("unveil");
1768 }
1769 
1770 static void
1771 apply_unveil_none(void)
1772 {
1773 	if (unveil("/", "") == -1)
1774 		fatal("unveil");
1775 
1776 	if (unveil(NULL, NULL) == -1)
1777 		fatal("unveil");
1778 }
1779 
1780 static void
1781 apply_unveil_selfexec(void)
1782 {
1783 	if (unveil(gotd.argv0, "x") == -1)
1784 		fatal("unveil %s", gotd.argv0);
1785 
1786 	if (unveil(NULL, NULL) == -1)
1787 		fatal("unveil");
1788 }
1789 
1790 int
1791 main(int argc, char **argv)
1792 {
1793 	const struct got_error *error = NULL;
1794 	int ch, fd = -1, daemonize = 1, verbosity = 0, noaction = 0;
1795 	const char *confpath = GOTD_CONF_PATH;
1796 	char *argv0 = argv[0];
1797 	char title[2048];
1798 	struct passwd *pw = NULL;
1799 	char *repo_path = NULL;
1800 	enum gotd_procid proc_id = PROC_GOTD;
1801 	struct event evsigint, evsigterm, evsighup, evsigusr1, evsigchld;
1802 	int *pack_fds = NULL, *temp_fds = NULL;
1803 	struct gotd_repo *repo = NULL;
1804 
1805 	TAILQ_INIT(&procs);
1806 
1807 	log_init(1, LOG_DAEMON); /* Log to stderr until daemonized. */
1808 
1809 	while ((ch = getopt(argc, argv, "Adf:LnP:RsSvW")) != -1) {
1810 		switch (ch) {
1811 		case 'A':
1812 			proc_id = PROC_AUTH;
1813 			break;
1814 		case 'd':
1815 			daemonize = 0;
1816 			break;
1817 		case 'f':
1818 			confpath = optarg;
1819 			break;
1820 		case 'L':
1821 			proc_id = PROC_LISTEN;
1822 			break;
1823 		case 'n':
1824 			noaction = 1;
1825 			break;
1826 		case 'P':
1827 			repo_path = realpath(optarg, NULL);
1828 			if (repo_path == NULL)
1829 				fatal("realpath '%s'", optarg);
1830 			break;
1831 		case 'R':
1832 			proc_id = PROC_REPO_READ;
1833 			break;
1834 		case 's':
1835 			proc_id = PROC_SESSION_READ;
1836 			break;
1837 		case 'S':
1838 			proc_id = PROC_SESSION_WRITE;
1839 			break;
1840 		case 'v':
1841 			if (verbosity < 3)
1842 				verbosity++;
1843 			break;
1844 		case 'W':
1845 			proc_id = PROC_REPO_WRITE;
1846 			break;
1847 		default:
1848 			usage();
1849 		}
1850 	}
1851 
1852 	argc -= optind;
1853 	argv += optind;
1854 
1855 	if (argc != 0)
1856 		usage();
1857 
1858 	if (geteuid() && (proc_id == PROC_GOTD || proc_id == PROC_LISTEN))
1859 		fatalx("need root privileges");
1860 
1861 	if (parse_config(confpath, proc_id, &gotd, 1) != 0)
1862 		return 1;
1863 
1864 	pw = getpwnam(gotd.user_name);
1865 	if (pw == NULL)
1866 		fatalx("user %s not found", gotd.user_name);
1867 
1868 	if (pw->pw_uid == 0)
1869 		fatalx("cannot run %s as the superuser", getprogname());
1870 
1871 	if (noaction) {
1872 		fprintf(stderr, "configuration OK\n");
1873 		return 0;
1874 	}
1875 
1876 	gotd.argv0 = argv0;
1877 	gotd.daemonize = daemonize;
1878 	gotd.verbosity = verbosity;
1879 	gotd.confpath = confpath;
1880 
1881 	/* Require an absolute path in argv[0] for reliable re-exec. */
1882 	if (!got_path_is_absolute(argv0))
1883 		fatalx("bad path \"%s\": must be an absolute path", argv0);
1884 
1885 	log_init(daemonize ? 0 : 1, LOG_DAEMON);
1886 	log_setverbose(verbosity);
1887 
1888 	if (proc_id == PROC_GOTD) {
1889 		snprintf(title, sizeof(title), "%s", gotd_proc_names[proc_id]);
1890 		arc4random_buf(&clients_hash_key, sizeof(clients_hash_key));
1891 		if (daemonize && daemon(1, 0) == -1)
1892 			fatal("daemon");
1893 		gotd.pid = getpid();
1894 		start_listener(argv0, confpath, daemonize, verbosity);
1895 	} else if (proc_id == PROC_LISTEN) {
1896 		snprintf(title, sizeof(title), "%s", gotd_proc_names[proc_id]);
1897 		if (verbosity) {
1898 			log_info("socket: %s", gotd.unix_socket_path);
1899 			log_info("user: %s", pw->pw_name);
1900 		}
1901 
1902 		fd = unix_socket_listen(gotd.unix_socket_path, pw->pw_uid,
1903 		    pw->pw_gid);
1904 		if (fd == -1) {
1905 			fatal("cannot listen on unix socket %s",
1906 			    gotd.unix_socket_path);
1907 		}
1908 	} else if (proc_id == PROC_AUTH) {
1909 		snprintf(title, sizeof(title), "%s %s",
1910 		    gotd_proc_names[proc_id], repo_path);
1911 	} else if (proc_id == PROC_REPO_READ || proc_id == PROC_REPO_WRITE ||
1912 	    proc_id == PROC_SESSION_READ || proc_id == PROC_SESSION_WRITE) {
1913 		error = got_repo_pack_fds_open(&pack_fds);
1914 		if (error != NULL)
1915 			fatalx("cannot open pack tempfiles: %s", error->msg);
1916 		error = got_repo_temp_fds_open(&temp_fds);
1917 		if (error != NULL)
1918 			fatalx("cannot open pack tempfiles: %s", error->msg);
1919 		if (repo_path == NULL)
1920 			fatalx("repository path not specified");
1921 		snprintf(title, sizeof(title), "%s %s",
1922 		    gotd_proc_names[proc_id], repo_path);
1923 	} else
1924 		fatal("invalid process id %d", proc_id);
1925 
1926 	setproctitle("%s", title);
1927 	log_procinit(title);
1928 
1929 	/* Drop root privileges. */
1930 	if (setgid(pw->pw_gid) == -1)
1931 		fatal("setgid %d failed", pw->pw_gid);
1932 	if (setuid(pw->pw_uid) == -1)
1933 		fatal("setuid %d failed", pw->pw_uid);
1934 
1935 	event_init();
1936 
1937 	switch (proc_id) {
1938 	case PROC_GOTD:
1939 #ifndef PROFILE
1940 		/* "exec" promise will be limited to argv[0] via unveil(2). */
1941 		if (pledge("stdio proc exec sendfd recvfd unveil", NULL) == -1)
1942 			err(1, "pledge");
1943 #endif
1944 		break;
1945 	case PROC_LISTEN:
1946 #ifndef PROFILE
1947 		if (pledge("stdio sendfd unix unveil", NULL) == -1)
1948 			err(1, "pledge");
1949 #endif
1950 		/*
1951 		 * Ensure that AF_UNIX bind(2) cannot be used with any other
1952 		 * sockets by revoking all filesystem access via unveil(2).
1953 		 */
1954 		apply_unveil_none();
1955 
1956 		listen_main(title, fd, gotd.connection_limits,
1957 		    gotd.nconnection_limits);
1958 		/* NOTREACHED */
1959 		break;
1960 	case PROC_AUTH:
1961 #ifndef PROFILE
1962 		if (pledge("stdio getpw recvfd unix unveil", NULL) == -1)
1963 			err(1, "pledge");
1964 #endif
1965 		/*
1966 		 * We need the "unix" pledge promise for getpeername(2) only.
1967 		 * Ensure that AF_UNIX bind(2) cannot be used by revoking all
1968 		 * filesystem access via unveil(2). Access to password database
1969 		 * files will still work since "getpw" bypasses unveil(2).
1970 		 */
1971 		apply_unveil_none();
1972 
1973 		auth_main(title, &gotd.repos, repo_path);
1974 		/* NOTREACHED */
1975 		break;
1976 	case PROC_SESSION_READ:
1977 	case PROC_SESSION_WRITE:
1978 #ifndef PROFILE
1979 		/*
1980 		 * The "recvfd" promise is only needed during setup and
1981 		 * will be removed in a later pledge(2) call.
1982 		 */
1983 		if (pledge("stdio rpath wpath cpath recvfd sendfd fattr flock "
1984 		    "unveil", NULL) == -1)
1985 			err(1, "pledge");
1986 #endif
1987 		if (proc_id == PROC_SESSION_READ)
1988 			apply_unveil_repo_readonly(repo_path, 1);
1989 		else
1990 			apply_unveil_repo_readwrite(repo_path);
1991 		session_main(title, repo_path, pack_fds, temp_fds,
1992 		    &gotd.request_timeout, proc_id);
1993 		/* NOTREACHED */
1994 		break;
1995 	case PROC_REPO_READ:
1996 #ifndef PROFILE
1997 		if (pledge("stdio rpath recvfd unveil", NULL) == -1)
1998 			err(1, "pledge");
1999 #endif
2000 		apply_unveil_repo_readonly(repo_path, 0);
2001 		repo_read_main(title, repo_path, pack_fds, temp_fds);
2002 		/* NOTREACHED */
2003 		exit(0);
2004 	case PROC_REPO_WRITE:
2005 #ifndef PROFILE
2006 		if (pledge("stdio rpath recvfd unveil", NULL) == -1)
2007 			err(1, "pledge");
2008 #endif
2009 		apply_unveil_repo_readonly(repo_path, 0);
2010 		repo = gotd_find_repo_by_path(repo_path, &gotd);
2011 		if (repo == NULL)
2012 			fatalx("no repository for path %s", repo_path);
2013 		repo_write_main(title, repo_path, pack_fds, temp_fds,
2014 		    &repo->protected_tag_namespaces,
2015 		    &repo->protected_branch_namespaces,
2016 		    &repo->protected_branches);
2017 		/* NOTREACHED */
2018 		exit(0);
2019 	default:
2020 		fatal("invalid process id %d", proc_id);
2021 	}
2022 
2023 	if (proc_id != PROC_GOTD)
2024 		fatal("invalid process id %d", proc_id);
2025 
2026 	evtimer_set(&gotd.listen_proc->tmo, kill_proc_timeout,
2027 	    gotd.listen_proc);
2028 
2029 	apply_unveil_selfexec();
2030 
2031 	signal_set(&evsigint, SIGINT, gotd_sighdlr, NULL);
2032 	signal_set(&evsigterm, SIGTERM, gotd_sighdlr, NULL);
2033 	signal_set(&evsighup, SIGHUP, gotd_sighdlr, NULL);
2034 	signal_set(&evsigusr1, SIGUSR1, gotd_sighdlr, NULL);
2035 	signal_set(&evsigchld, SIGCHLD, gotd_sighdlr, NULL);
2036 	signal(SIGPIPE, SIG_IGN);
2037 
2038 	signal_add(&evsigint, NULL);
2039 	signal_add(&evsigterm, NULL);
2040 	signal_add(&evsighup, NULL);
2041 	signal_add(&evsigusr1, NULL);
2042 	signal_add(&evsigchld, NULL);
2043 
2044 	gotd_imsg_event_add(&gotd.listen_proc->iev);
2045 
2046 	event_dispatch();
2047 
2048 	free(repo_path);
2049 	gotd_shutdown();
2050 
2051 	return 0;
2052 }