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Date:: Thu Nov 16 15:37:14 2023 UTC
Message:: allow gotd repo read/write processes to max out data-size resource limits Proccessing large pack files can easily result in out-of-memory errors if the datasize limit is too conservative.
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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 #include <sys/resource.h>
26 
27 #include <fcntl.h>
28 #include <err.h>
29 #include <errno.h>
30 #include <event.h>
31 #include <limits.h>
32 #include <pwd.h>
33 #include <imsg.h>
34 #include <sha1.h>
35 #include <sha2.h>
36 #include <signal.h>
37 #include <siphash.h>
38 #include <stdarg.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <syslog.h>
43 #include <unistd.h>
44 
45 #include "got_error.h"
46 #include "got_opentemp.h"
47 #include "got_path.h"
48 #include "got_repository.h"
49 #include "got_object.h"
50 #include "got_reference.h"
51 
52 #include "got_lib_delta.h"
53 #include "got_lib_object.h"
54 #include "got_lib_object_cache.h"
55 #include "got_lib_hash.h"
56 #include "got_lib_gitproto.h"
57 #include "got_lib_pack.h"
58 #include "got_lib_repository.h"
59 
60 #include "gotd.h"
61 #include "log.h"
62 #include "listen.h"
63 #include "auth.h"
64 #include "session.h"
65 #include "repo_read.h"
66 #include "repo_write.h"
67 
68 #ifndef nitems
69 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
70 #endif
71 
72 enum gotd_client_state {
73 	GOTD_CLIENT_STATE_NEW,
74 	GOTD_CLIENT_STATE_ACCESS_GRANTED,
75 };
76 
77 struct gotd_child_proc {
78 	pid_t				 pid;
79 	enum gotd_procid		 type;
80 	char				 repo_name[NAME_MAX];
81 	char				 repo_path[PATH_MAX];
82 	int				 pipe[2];
83 	struct gotd_imsgev		 iev;
84 	struct event			 tmo;
85 
86 	TAILQ_ENTRY(gotd_child_proc)	 entry;
87 };
88 TAILQ_HEAD(gotd_procs, gotd_child_proc) procs;
89 
90 struct gotd_client {
91 	STAILQ_ENTRY(gotd_client)	 entry;
92 	enum gotd_client_state		 state;
93 	uint32_t			 id;
94 	int				 fd;
95 	struct gotd_imsgev		 iev;
96 	struct event			 tmo;
97 	uid_t				 euid;
98 	gid_t				 egid;
99 	struct gotd_child_proc		*repo;
100 	struct gotd_child_proc		*auth;
101 	struct gotd_child_proc		*session;
102 	int				 required_auth;
103 };
104 STAILQ_HEAD(gotd_clients, gotd_client);
105 
106 static struct gotd_clients gotd_clients[GOTD_CLIENT_TABLE_SIZE];
107 static SIPHASH_KEY clients_hash_key;
108 volatile int client_cnt;
109 static struct timeval auth_timeout = { 5, 0 };
110 static struct gotd gotd;
111 
112 void gotd_sighdlr(int sig, short event, void *arg);
113 static void gotd_shutdown(void);
114 static const struct got_error *start_session_child(struct gotd_client *,
115     struct gotd_repo *, char *, const char *, int, int);
116 static const struct got_error *start_repo_child(struct gotd_client *,
117     enum gotd_procid, struct gotd_repo *, char *, const char *, int, int);
118 static const struct got_error *start_auth_child(struct gotd_client *, int,
119     struct gotd_repo *, char *, const char *, int, int);
120 static void kill_proc(struct gotd_child_proc *, int);
121 static void disconnect(struct gotd_client *);
122 
123 __dead static void
124 usage(void)
125 {
126 	fprintf(stderr, "usage: %s [-dnv] [-f config-file]\n", getprogname());
127 	exit(1);
128 }
129 
130 static int
131 unix_socket_listen(const char *unix_socket_path, uid_t uid, gid_t gid)
132 {
133 	struct sockaddr_un sun;
134 	int fd = -1;
135 	mode_t old_umask, mode;
136 
137 	fd = socket(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK| SOCK_CLOEXEC, 0);
138 	if (fd == -1) {
139 		log_warn("socket");
140 		return -1;
141 	}
142 
143 	sun.sun_family = AF_UNIX;
144 	if (strlcpy(sun.sun_path, unix_socket_path,
145 	    sizeof(sun.sun_path)) >= sizeof(sun.sun_path)) {
146 		log_warnx("%s: name too long", unix_socket_path);
147 		close(fd);
148 		return -1;
149 	}
150 
151 	if (unlink(unix_socket_path) == -1) {
152 		if (errno != ENOENT) {
153 			log_warn("unlink %s", unix_socket_path);
154 			close(fd);
155 			return -1;
156 		}
157 	}
158 
159 	old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);
160 	mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH;
161 
162 	if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
163 		log_warn("bind: %s", unix_socket_path);
164 		close(fd);
165 		umask(old_umask);
166 		return -1;
167 	}
168 
169 	umask(old_umask);
170 
171 	if (chmod(unix_socket_path, mode) == -1) {
172 		log_warn("chmod %o %s", mode, unix_socket_path);
173 		close(fd);
174 		unlink(unix_socket_path);
175 		return -1;
176 	}
177 
178 	if (chown(unix_socket_path, uid, gid) == -1) {
179 		log_warn("chown %s uid=%d gid=%d", unix_socket_path, uid, gid);
180 		close(fd);
181 		unlink(unix_socket_path);
182 		return -1;
183 	}
184 
185 	if (listen(fd, GOTD_UNIX_SOCKET_BACKLOG) == -1) {
186 		log_warn("listen");
187 		close(fd);
188 		unlink(unix_socket_path);
189 		return -1;
190 	}
191 
192 	return fd;
193 }
194 
195 static uint64_t
196 client_hash(uint32_t client_id)
197 {
198 	return SipHash24(&clients_hash_key, &client_id, sizeof(client_id));
199 }
200 
201 static void
202 add_client(struct gotd_client *client)
203 {
204 	uint64_t slot = client_hash(client->id) % nitems(gotd_clients);
205 	STAILQ_INSERT_HEAD(&gotd_clients[slot], client, entry);
206 	client_cnt++;
207 }
208 
209 static struct gotd_client *
210 find_client(uint32_t client_id)
211 {
212 	uint64_t slot;
213 	struct gotd_client *c;
214 
215 	slot = client_hash(client_id) % nitems(gotd_clients);
216 	STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
217 		if (c->id == client_id)
218 			return c;
219 	}
220 
221 	return NULL;
222 }
223 
224 static struct gotd_client *
225 find_client_by_proc_fd(int fd)
226 {
227 	uint64_t slot;
228 
229 	for (slot = 0; slot < nitems(gotd_clients); slot++) {
230 		struct gotd_client *c;
231 
232 		STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
233 			if (c->repo && c->repo->iev.ibuf.fd == fd)
234 				return c;
235 			if (c->auth && c->auth->iev.ibuf.fd == fd)
236 				return c;
237 			if (c->session && c->session->iev.ibuf.fd == fd)
238 				return c;
239 		}
240 	}
241 
242 	return NULL;
243 }
244 
245 static int
246 client_is_reading(struct gotd_client *client)
247 {
248 	return (client->required_auth &
249 	    (GOTD_AUTH_READ | GOTD_AUTH_WRITE)) == GOTD_AUTH_READ;
250 }
251 
252 static int
253 client_is_writing(struct gotd_client *client)
254 {
255 	return (client->required_auth &
256 	    (GOTD_AUTH_READ | GOTD_AUTH_WRITE)) ==
257 	    (GOTD_AUTH_READ | GOTD_AUTH_WRITE);
258 }
259 
260 static const struct got_error *
261 ensure_client_is_not_writing(struct gotd_client *client)
262 {
263 	if (client_is_writing(client)) {
264 		return got_error_fmt(GOT_ERR_BAD_PACKET,
265 		    "uid %d made a read-request but is writing to "
266 		    "a repository", client->euid);
267 	}
268 
269 	return NULL;
270 }
271 
272 static const struct got_error *
273 ensure_client_is_not_reading(struct gotd_client *client)
274 {
275 	if (client_is_reading(client)) {
276 		return got_error_fmt(GOT_ERR_BAD_PACKET,
277 		    "uid %d made a write-request but is reading from "
278 		    "a repository", client->euid);
279 	}
280 
281 	return NULL;
282 }
283 
284 static void
285 proc_done(struct gotd_child_proc *proc)
286 {
287 	struct gotd_client *client;
288 
289 	TAILQ_REMOVE(&procs, proc, entry);
290 
291 	client = find_client_by_proc_fd(proc->iev.ibuf.fd);
292 	if (client != NULL) {
293 		if (proc == client->repo)
294 			client->repo = NULL;
295 		if (proc == client->auth)
296 			client->auth = NULL;
297 		if (proc == client->session)
298 			client->session = NULL;
299 		disconnect(client);
300 	}
301 
302 	evtimer_del(&proc->tmo);
303 
304 	if (proc->iev.ibuf.fd != -1) {
305 		event_del(&proc->iev.ev);
306 		msgbuf_clear(&proc->iev.ibuf.w);
307 		close(proc->iev.ibuf.fd);
308 	}
309 
310 	free(proc);
311 }
312 
313 static void
314 kill_repo_proc(struct gotd_client *client)
315 {
316 	if (client->repo == NULL)
317 		return;
318 
319 	kill_proc(client->repo, 0);
320 	client->repo = NULL;
321 }
322 
323 static void
324 kill_auth_proc(struct gotd_client *client)
325 {
326 	if (client->auth == NULL)
327 		return;
328 
329 	kill_proc(client->auth, 0);
330 	client->auth = NULL;
331 }
332 
333 static void
334 kill_session_proc(struct gotd_client *client)
335 {
336 	if (client->session == NULL)
337 		return;
338 
339 	kill_proc(client->session, 0);
340 	client->session = NULL;
341 }
342 
343 static void
344 disconnect(struct gotd_client *client)
345 {
346 	struct gotd_imsg_disconnect idisconnect;
347 	struct gotd_child_proc *listen_proc = gotd.listen_proc;
348 	uint64_t slot;
349 
350 	log_debug("uid %d: disconnecting", client->euid);
351 
352 	kill_auth_proc(client);
353 	kill_session_proc(client);
354 	kill_repo_proc(client);
355 
356 	idisconnect.client_id = client->id;
357 	if (gotd_imsg_compose_event(&listen_proc->iev,
358 	    GOTD_IMSG_DISCONNECT, PROC_GOTD, -1,
359 	    &idisconnect, sizeof(idisconnect)) == -1)
360 		log_warn("imsg compose DISCONNECT");
361 
362 	slot = client_hash(client->id) % nitems(gotd_clients);
363 	STAILQ_REMOVE(&gotd_clients[slot], client, gotd_client, entry);
364 	imsg_clear(&client->iev.ibuf);
365 	event_del(&client->iev.ev);
366 	evtimer_del(&client->tmo);
367 	if (client->fd != -1)
368 		close(client->fd);
369 	else if (client->iev.ibuf.fd != -1)
370 		close(client->iev.ibuf.fd);
371 	free(client);
372 	client_cnt--;
373 }
374 
375 static void
376 disconnect_on_error(struct gotd_client *client, const struct got_error *err)
377 {
378 	struct imsgbuf ibuf;
379 
380 	if (err->code != GOT_ERR_EOF) {
381 		log_warnx("uid %d: %s", client->euid, err->msg);
382 		if (client->fd != -1) {
383 			imsg_init(&ibuf, client->fd);
384 			gotd_imsg_send_error(&ibuf, 0, PROC_GOTD, err);
385 			imsg_clear(&ibuf);
386 		}
387 	}
388 	disconnect(client);
389 }
390 
391 static const struct got_error *
392 send_repo_info(struct gotd_imsgev *iev, struct gotd_repo *repo)
393 {
394 	const struct got_error *err = NULL;
395 	struct gotd_imsg_info_repo irepo;
396 
397 	memset(&irepo, 0, sizeof(irepo));
398 
399 	if (strlcpy(irepo.repo_name, repo->name, sizeof(irepo.repo_name))
400 	    >= sizeof(irepo.repo_name))
401 		return got_error_msg(GOT_ERR_NO_SPACE, "repo name too long");
402 	if (strlcpy(irepo.repo_path, repo->path, sizeof(irepo.repo_path))
403 	    >= sizeof(irepo.repo_path))
404 		return got_error_msg(GOT_ERR_NO_SPACE, "repo path too long");
405 
406 	if (gotd_imsg_compose_event(iev, GOTD_IMSG_INFO_REPO, PROC_GOTD, -1,
407 	    &irepo, sizeof(irepo)) == -1) {
408 		err = got_error_from_errno("imsg compose INFO_REPO");
409 		if (err)
410 			return err;
411 	}
412 
413 	return NULL;
414 }
415 
416 static const struct got_error *
417 send_client_info(struct gotd_imsgev *iev, struct gotd_client *client)
418 {
419 	const struct got_error *err = NULL;
420 	struct gotd_imsg_info_client iclient;
421 	struct gotd_child_proc *proc;
422 
423 	memset(&iclient, 0, sizeof(iclient));
424 	iclient.euid = client->euid;
425 	iclient.egid = client->egid;
426 
427 	proc = client->repo;
428 	if (proc) {
429 		if (strlcpy(iclient.repo_name, proc->repo_path,
430 		    sizeof(iclient.repo_name)) >= sizeof(iclient.repo_name)) {
431 			return got_error_msg(GOT_ERR_NO_SPACE,
432 			    "repo name too long");
433 		}
434 		if (client_is_writing(client))
435 			iclient.is_writing = 1;
436 
437 		iclient.repo_child_pid = proc->pid;
438 	}
439 
440 	if (client->session)
441 		iclient.session_child_pid = client->session->pid;
442 
443 	if (gotd_imsg_compose_event(iev, GOTD_IMSG_INFO_CLIENT, PROC_GOTD, -1,
444 	    &iclient, sizeof(iclient)) == -1) {
445 		err = got_error_from_errno("imsg compose INFO_CLIENT");
446 		if (err)
447 			return err;
448 	}
449 
450 	return NULL;
451 }
452 
453 static const struct got_error *
454 send_info(struct gotd_client *client)
455 {
456 	const struct got_error *err = NULL;
457 	struct gotd_imsg_info info;
458 	uint64_t slot;
459 	struct gotd_repo *repo;
460 
461 	if (client->euid != 0)
462 		return got_error_set_errno(EPERM, "info");
463 
464 	info.pid = gotd.pid;
465 	info.verbosity = gotd.verbosity;
466 	info.nrepos = gotd.nrepos;
467 	info.nclients = client_cnt - 1;
468 
469 	if (gotd_imsg_compose_event(&client->iev, GOTD_IMSG_INFO, PROC_GOTD, -1,
470 	    &info, sizeof(info)) == -1) {
471 		err = got_error_from_errno("imsg compose INFO");
472 		if (err)
473 			return err;
474 	}
475 
476 	TAILQ_FOREACH(repo, &gotd.repos, entry) {
477 		err = send_repo_info(&client->iev, repo);
478 		if (err)
479 			return err;
480 	}
481 
482 	for (slot = 0; slot < nitems(gotd_clients); slot++) {
483 		struct gotd_client *c;
484 		STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
485 			if (c->id == client->id)
486 				continue;
487 			err = send_client_info(&client->iev, c);
488 			if (err)
489 				return err;
490 		}
491 	}
492 
493 	return NULL;
494 }
495 
496 static const struct got_error *
497 stop_gotd(struct gotd_client *client)
498 {
499 
500 	if (client->euid != 0)
501 		return got_error_set_errno(EPERM, "stop");
502 
503 	gotd_shutdown();
504 	/* NOTREACHED */
505 	return NULL;
506 }
507 
508 static const struct got_error *
509 start_client_authentication(struct gotd_client *client, struct imsg *imsg)
510 {
511 	const struct got_error *err;
512 	struct gotd_imsg_list_refs ireq;
513 	struct gotd_repo *repo = NULL;
514 	size_t datalen;
515 
516 	log_debug("list-refs request from uid %d", client->euid);
517 
518 	if (client->state != GOTD_CLIENT_STATE_NEW)
519 		return got_error_msg(GOT_ERR_BAD_REQUEST,
520 		    "unexpected list-refs request received");
521 
522 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
523 	if (datalen != sizeof(ireq))
524 		return got_error(GOT_ERR_PRIVSEP_LEN);
525 
526 	memcpy(&ireq, imsg->data, datalen);
527 
528 	if (ireq.client_is_reading) {
529 		err = ensure_client_is_not_writing(client);
530 		if (err)
531 			return err;
532 		repo = gotd_find_repo_by_name(ireq.repo_name, &gotd);
533 		if (repo == NULL)
534 			return got_error(GOT_ERR_NOT_GIT_REPO);
535 		err = start_auth_child(client, GOTD_AUTH_READ, repo,
536 		    gotd.argv0, gotd.confpath, gotd.daemonize,
537 		    gotd.verbosity);
538 		if (err)
539 			return err;
540 	} else {
541 		err = ensure_client_is_not_reading(client);
542 		if (err)
543 			return err;
544 		repo = gotd_find_repo_by_name(ireq.repo_name, &gotd);
545 		if (repo == NULL)
546 			return got_error(GOT_ERR_NOT_GIT_REPO);
547 		err = start_auth_child(client,
548 		    GOTD_AUTH_READ | GOTD_AUTH_WRITE,
549 		    repo, gotd.argv0, gotd.confpath, gotd.daemonize,
550 		    gotd.verbosity);
551 		if (err)
552 			return err;
553 	}
554 
555 	evtimer_add(&client->tmo, &auth_timeout);
556 
557 	/* Flow continues upon authentication success/failure or timeout. */
558 	return NULL;
559 }
560 
561 static void
562 gotd_request(int fd, short events, void *arg)
563 {
564 	struct gotd_imsgev *iev = arg;
565 	struct imsgbuf *ibuf = &iev->ibuf;
566 	struct gotd_client *client = iev->handler_arg;
567 	const struct got_error *err = NULL;
568 	struct imsg imsg;
569 	ssize_t n;
570 
571 	if (events & EV_WRITE) {
572 		while (ibuf->w.queued) {
573 			n = msgbuf_write(&ibuf->w);
574 			if (n == -1 && errno == EPIPE) {
575 				/*
576 				 * The client has closed its socket.
577 				 * This can happen when Git clients are
578 				 * done sending pack file data.
579 				 */
580 				msgbuf_clear(&ibuf->w);
581 				continue;
582 			} else if (n == -1 && errno != EAGAIN) {
583 				err = got_error_from_errno("imsg_flush");
584 				disconnect_on_error(client, err);
585 				return;
586 			}
587 			if (n == 0) {
588 				/* Connection closed. */
589 				err = got_error(GOT_ERR_EOF);
590 				disconnect_on_error(client, err);
591 				return;
592 			}
593 		}
594 
595 		/* Disconnect gotctl(8) now that messages have been sent. */
596 		if (!client_is_reading(client) && !client_is_writing(client)) {
597 			disconnect(client);
598 			return;
599 		}
600 	}
601 
602 	if ((events & EV_READ) == 0)
603 		return;
604 
605 	memset(&imsg, 0, sizeof(imsg));
606 
607 	while (err == NULL) {
608 		err = gotd_imsg_recv(&imsg, ibuf, 0);
609 		if (err) {
610 			if (err->code == GOT_ERR_PRIVSEP_READ)
611 				err = NULL;
612 			break;
613 		}
614 
615 		evtimer_del(&client->tmo);
616 
617 		switch (imsg.hdr.type) {
618 		case GOTD_IMSG_INFO:
619 			err = send_info(client);
620 			break;
621 		case GOTD_IMSG_STOP:
622 			err = stop_gotd(client);
623 			break;
624 		case GOTD_IMSG_LIST_REFS:
625 			err = start_client_authentication(client, &imsg);
626 			break;
627 		default:
628 			log_debug("unexpected imsg %d", imsg.hdr.type);
629 			err = got_error(GOT_ERR_PRIVSEP_MSG);
630 			break;
631 		}
632 
633 		imsg_free(&imsg);
634 	}
635 
636 	if (err) {
637 		disconnect_on_error(client, err);
638 	} else {
639 		gotd_imsg_event_add(&client->iev);
640 	}
641 }
642 
643 static void
644 gotd_auth_timeout(int fd, short events, void *arg)
645 {
646 	struct gotd_client *client = arg;
647 
648 	log_debug("disconnecting uid %d due to authentication timeout",
649 	    client->euid);
650 	disconnect(client);
651 }
652 
653 static const struct got_error *
654 recv_connect(uint32_t *client_id, struct imsg *imsg)
655 {
656 	const struct got_error *err = NULL;
657 	struct gotd_imsg_connect iconnect;
658 	size_t datalen;
659 	int s = -1;
660 	struct gotd_client *client = NULL;
661 
662 	*client_id = 0;
663 
664 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
665 	if (datalen != sizeof(iconnect))
666 		return got_error(GOT_ERR_PRIVSEP_LEN);
667 	memcpy(&iconnect, imsg->data, sizeof(iconnect));
668 
669 	s = imsg->fd;
670 	if (s == -1) {
671 		err = got_error(GOT_ERR_PRIVSEP_NO_FD);
672 		goto done;
673 	}
674 
675 	if (find_client(iconnect.client_id)) {
676 		err = got_error_msg(GOT_ERR_CLIENT_ID, "duplicate client ID");
677 		goto done;
678 	}
679 
680 	client = calloc(1, sizeof(*client));
681 	if (client == NULL) {
682 		err = got_error_from_errno("calloc");
683 		goto done;
684 	}
685 
686 	*client_id = iconnect.client_id;
687 
688 	client->state = GOTD_CLIENT_STATE_NEW;
689 	client->id = iconnect.client_id;
690 	client->fd = s;
691 	s = -1;
692 	/* The auth process will verify UID/GID for us. */
693 	client->euid = iconnect.euid;
694 	client->egid = iconnect.egid;
695 
696 	imsg_init(&client->iev.ibuf, client->fd);
697 	client->iev.handler = gotd_request;
698 	client->iev.events = EV_READ;
699 	client->iev.handler_arg = client;
700 
701 	event_set(&client->iev.ev, client->fd, EV_READ, gotd_request,
702 	    &client->iev);
703 	gotd_imsg_event_add(&client->iev);
704 
705 	evtimer_set(&client->tmo, gotd_auth_timeout, client);
706 
707 	add_client(client);
708 	log_debug("%s: new client uid %d connected on fd %d", __func__,
709 	    client->euid, client->fd);
710 done:
711 	if (err) {
712 		struct gotd_child_proc *listen_proc = gotd.listen_proc;
713 		struct gotd_imsg_disconnect idisconnect;
714 
715 		idisconnect.client_id = client->id;
716 		if (gotd_imsg_compose_event(&listen_proc->iev,
717 		    GOTD_IMSG_DISCONNECT, PROC_GOTD, -1,
718 		    &idisconnect, sizeof(idisconnect)) == -1)
719 			log_warn("imsg compose DISCONNECT");
720 
721 		if (s != -1)
722 			close(s);
723 	}
724 
725 	return err;
726 }
727 
728 static const char *gotd_proc_names[PROC_MAX] = {
729 	"parent",
730 	"listen",
731 	"auth",
732 	"session_read",
733 	"session_write",
734 	"repo_read",
735 	"repo_write",
736 	"gitwrapper"
737 };
738 
739 static void
740 kill_proc(struct gotd_child_proc *proc, int fatal)
741 {
742 	struct timeval tv = { 5, 0 };
743 
744 	log_debug("kill -%d %d", fatal ? SIGKILL : SIGTERM, proc->pid);
745 
746 	if (proc->iev.ibuf.fd != -1) {
747 		event_del(&proc->iev.ev);
748 		msgbuf_clear(&proc->iev.ibuf.w);
749 		close(proc->iev.ibuf.fd);
750 		proc->iev.ibuf.fd = -1;
751 	}
752 
753 	if (!evtimer_pending(&proc->tmo, NULL) && !fatal)
754 		evtimer_add(&proc->tmo, &tv);
755 
756 	if (fatal) {
757 		log_warnx("sending SIGKILL to PID %d", proc->pid);
758 		kill(proc->pid, SIGKILL);
759 	} else
760 		kill(proc->pid, SIGTERM);
761 }
762 
763 static void
764 kill_proc_timeout(int fd, short ev, void *d)
765 {
766 	struct gotd_child_proc *proc = d;
767 
768 	log_warnx("timeout waiting for PID %d to terminate;"
769 	    " retrying with force", proc->pid);
770 	kill_proc(proc, 1);
771 }
772 
773 static void
774 gotd_shutdown(void)
775 {
776 	uint64_t slot;
777 
778 	log_debug("shutting down");
779 	for (slot = 0; slot < nitems(gotd_clients); slot++) {
780 		struct gotd_client *c, *tmp;
781 
782 		STAILQ_FOREACH_SAFE(c, &gotd_clients[slot], entry, tmp)
783 			disconnect(c);
784 	}
785 
786 	kill_proc(gotd.listen_proc, 0);
787 
788 	log_info("terminating");
789 	exit(0);
790 }
791 
792 static struct gotd_child_proc *
793 find_proc_by_pid(pid_t pid)
794 {
795 	struct gotd_child_proc *proc = NULL;
796 
797 	TAILQ_FOREACH(proc, &procs, entry)
798 		if (proc->pid == pid)
799 			break;
800 
801 	return proc;
802 }
803 
804 void
805 gotd_sighdlr(int sig, short event, void *arg)
806 {
807 	struct gotd_child_proc *proc;
808 	pid_t pid;
809 	int status;
810 
811 	/*
812 	 * Normal signal handler rules don't apply because libevent
813 	 * decouples for us.
814 	 */
815 
816 	switch (sig) {
817 	case SIGHUP:
818 		log_info("%s: ignoring SIGHUP", __func__);
819 		break;
820 	case SIGUSR1:
821 		log_info("%s: ignoring SIGUSR1", __func__);
822 		break;
823 	case SIGTERM:
824 	case SIGINT:
825 		gotd_shutdown();
826 		break;
827 	case SIGCHLD:
828 		for (;;) {
829 			pid = waitpid(WAIT_ANY, &status, WNOHANG);
830 			if (pid == -1) {
831 				if (errno == EINTR)
832 					continue;
833 				if (errno == ECHILD)
834 					break;
835 				fatal("waitpid");
836 			}
837 			if (pid == 0)
838 				break;
839 
840 			log_debug("reaped pid %d", pid);
841 			proc = find_proc_by_pid(pid);
842 			if (proc == NULL) {
843 				log_info("caught exit of unknown child %d",
844 				    pid);
845 				continue;
846 			}
847 
848 			if (WIFSIGNALED(status)) {
849 				log_warnx("child PID %d terminated with"
850 				    " signal %d", pid, WTERMSIG(status));
851 			}
852 
853 			proc_done(proc);
854 		}
855 		break;
856 	default:
857 		fatalx("unexpected signal");
858 	}
859 }
860 
861 static const struct got_error *
862 ensure_proc_is_reading(struct gotd_client *client,
863     struct gotd_child_proc *proc)
864 {
865 	if (!client_is_reading(client)) {
866 		kill_proc(proc, 1);
867 		return got_error_fmt(GOT_ERR_BAD_PACKET,
868 		    "PID %d handled a read-request for uid %d but this "
869 		    "user is not reading from a repository", proc->pid,
870 		    client->euid);
871 	}
872 
873 	return NULL;
874 }
875 
876 static const struct got_error *
877 ensure_proc_is_writing(struct gotd_client *client,
878     struct gotd_child_proc *proc)
879 {
880 	if (!client_is_writing(client)) {
881 		kill_proc(proc, 1);
882 		return got_error_fmt(GOT_ERR_BAD_PACKET,
883 		    "PID %d handled a write-request for uid %d but this "
884 		    "user is not writing to a repository", proc->pid,
885 		    client->euid);
886 	}
887 
888 	return NULL;
889 }
890 
891 static int
892 verify_imsg_src(struct gotd_client *client, struct gotd_child_proc *proc,
893     struct imsg *imsg)
894 {
895 	const struct got_error *err;
896 	int ret = 0;
897 
898 	if (proc->type == PROC_REPO_READ || proc->type == PROC_REPO_WRITE) {
899 		if (client->repo == NULL)
900 			fatalx("no process found for uid %d", client->euid);
901 		if (proc->pid != client->repo->pid) {
902 			kill_proc(proc, 1);
903 			log_warnx("received message from PID %d for uid %d, "
904 			    "while PID %d is the process serving this user",
905 			    proc->pid, client->euid, client->repo->pid);
906 			return 0;
907 		}
908 	}
909 	if (proc->type == PROC_SESSION_READ ||
910 	    proc->type == PROC_SESSION_WRITE) {
911 		if (client->session == NULL) {
912 			log_warnx("no session found for uid %d", client->euid);
913 			return 0;
914 		}
915 		if (proc->pid != client->session->pid) {
916 			kill_proc(proc, 1);
917 			log_warnx("received message from PID %d for uid %d, "
918 			    "while PID %d is the process serving this user",
919 			    proc->pid, client->euid, client->session->pid);
920 			return 0;
921 		}
922 	}
923 
924 	switch (imsg->hdr.type) {
925 	case GOTD_IMSG_ERROR:
926 		ret = 1;
927 		break;
928 	case GOTD_IMSG_CONNECT:
929 		if (proc->type != PROC_LISTEN) {
930 			err = got_error_fmt(GOT_ERR_BAD_PACKET,
931 			    "new connection for uid %d from PID %d "
932 			    "which is not the listen process",
933 			    proc->pid, client->euid);
934 		} else
935 			ret = 1;
936 		break;
937 	case GOTD_IMSG_ACCESS_GRANTED:
938 		if (proc->type != PROC_AUTH) {
939 			err = got_error_fmt(GOT_ERR_BAD_PACKET,
940 			    "authentication of uid %d from PID %d "
941 			    "which is not the auth process",
942 			    proc->pid, client->euid);
943 		} else
944 			ret = 1;
945 		break;
946 	case GOTD_IMSG_CLIENT_SESSION_READY:
947 		if (proc->type != PROC_SESSION_READ &&
948 		    proc->type != PROC_SESSION_WRITE) {
949 			err = got_error_fmt(GOT_ERR_BAD_PACKET,
950 			    "unexpected \"ready\" signal from PID %d",
951 			    proc->pid);
952 		} else
953 			ret = 1;
954 		break;
955 	case GOTD_IMSG_REPO_CHILD_READY:
956 		if (proc->type != PROC_REPO_READ &&
957 		    proc->type != PROC_REPO_WRITE) {
958 			err = got_error_fmt(GOT_ERR_BAD_PACKET,
959 			    "unexpected \"ready\" signal from PID %d",
960 			    proc->pid);
961 		} else
962 			ret = 1;
963 		break;
964 	case GOTD_IMSG_PACKFILE_DONE:
965 		err = ensure_proc_is_reading(client, proc);
966 		if (err)
967 			log_warnx("uid %d: %s", client->euid, err->msg);
968 		else
969 			ret = 1;
970 		break;
971 	case GOTD_IMSG_PACKFILE_INSTALL:
972 	case GOTD_IMSG_REF_UPDATES_START:
973 	case GOTD_IMSG_REF_UPDATE:
974 		err = ensure_proc_is_writing(client, proc);
975 		if (err)
976 			log_warnx("uid %d: %s", client->euid, err->msg);
977 		else
978 			ret = 1;
979 		break;
980 	default:
981 		log_debug("%s: unexpected imsg %d", __func__, imsg->hdr.type);
982 		break;
983 	}
984 
985 	return ret;
986 }
987 
988 static const struct got_error *
989 connect_repo_child(struct gotd_client *client,
990     struct gotd_child_proc *repo_proc)
991 {
992 	static const struct got_error *err;
993 	struct gotd_imsgev *session_iev = &client->session->iev;
994 	struct gotd_imsg_connect_repo_child ireq;
995 	int pipe[2];
996 
997 	if (client->state != GOTD_CLIENT_STATE_ACCESS_GRANTED)
998 		return got_error_msg(GOT_ERR_BAD_REQUEST,
999 		    "unexpected repo child ready signal received");
1000 
1001 	if (socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK,
1002 	    PF_UNSPEC, pipe) == -1)
1003 		fatal("socketpair");
1004 
1005 	memset(&ireq, 0, sizeof(ireq));
1006 	ireq.client_id = client->id;
1007 	ireq.proc_id = repo_proc->type;
1008 
1009 	/* Pass repo child pipe to session child process. */
1010 	if (gotd_imsg_compose_event(session_iev, GOTD_IMSG_CONNECT_REPO_CHILD,
1011 	    PROC_GOTD, pipe[0], &ireq, sizeof(ireq)) == -1) {
1012 		err = got_error_from_errno("imsg compose CONNECT_REPO_CHILD");
1013 		close(pipe[0]);
1014 		close(pipe[1]);
1015 		return err;
1016 	}
1017 
1018 	/* Pass session child pipe to repo child process. */
1019 	if (gotd_imsg_compose_event(&repo_proc->iev,
1020 	    GOTD_IMSG_CONNECT_REPO_CHILD, PROC_GOTD, pipe[1], NULL, 0) == -1) {
1021 		err = got_error_from_errno("imsg compose CONNECT_REPO_CHILD");
1022 		close(pipe[1]);
1023 		return err;
1024 	}
1025 
1026 	return NULL;
1027 }
1028 
1029 static void
1030 gotd_dispatch_listener(int fd, short event, void *arg)
1031 {
1032 	struct gotd_imsgev *iev = arg;
1033 	struct imsgbuf *ibuf = &iev->ibuf;
1034 	struct gotd_child_proc *proc = gotd.listen_proc;
1035 	ssize_t n;
1036 	int shut = 0;
1037 	struct imsg imsg;
1038 
1039 	if (proc->iev.ibuf.fd != fd)
1040 		fatalx("%s: unexpected fd %d", __func__, fd);
1041 
1042 	if (event & EV_READ) {
1043 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1044 			fatal("imsg_read error");
1045 		if (n == 0) {
1046 			/* Connection closed. */
1047 			shut = 1;
1048 			goto done;
1049 		}
1050 	}
1051 
1052 	if (event & EV_WRITE) {
1053 		n = msgbuf_write(&ibuf->w);
1054 		if (n == -1 && errno != EAGAIN)
1055 			fatal("msgbuf_write");
1056 		if (n == 0) {
1057 			/* Connection closed. */
1058 			shut = 1;
1059 			goto done;
1060 		}
1061 	}
1062 
1063 	for (;;) {
1064 		const struct got_error *err = NULL;
1065 		struct gotd_client *client = NULL;
1066 		uint32_t client_id = 0;
1067 		int do_disconnect = 0;
1068 
1069 		if ((n = imsg_get(ibuf, &imsg)) == -1)
1070 			fatal("%s: imsg_get error", __func__);
1071 		if (n == 0)	/* No more messages. */
1072 			break;
1073 
1074 		switch (imsg.hdr.type) {
1075 		case GOTD_IMSG_ERROR:
1076 			do_disconnect = 1;
1077 			err = gotd_imsg_recv_error(&client_id, &imsg);
1078 			break;
1079 		case GOTD_IMSG_CONNECT:
1080 			err = recv_connect(&client_id, &imsg);
1081 			break;
1082 		default:
1083 			log_debug("unexpected imsg %d", imsg.hdr.type);
1084 			break;
1085 		}
1086 
1087 		client = find_client(client_id);
1088 		if (client == NULL) {
1089 			log_warnx("%s: client not found", __func__);
1090 			imsg_free(&imsg);
1091 			continue;
1092 		}
1093 
1094 		if (err)
1095 			log_warnx("uid %d: %s", client->euid, err->msg);
1096 
1097 		if (do_disconnect) {
1098 			if (err)
1099 				disconnect_on_error(client, err);
1100 			else
1101 				disconnect(client);
1102 		}
1103 
1104 		imsg_free(&imsg);
1105 	}
1106 done:
1107 	if (!shut) {
1108 		gotd_imsg_event_add(iev);
1109 	} else {
1110 		/* This pipe is dead. Remove its event handler */
1111 		event_del(&iev->ev);
1112 		event_loopexit(NULL);
1113 	}
1114 }
1115 
1116 static void
1117 gotd_dispatch_auth_child(int fd, short event, void *arg)
1118 {
1119 	const struct got_error *err = NULL;
1120 	struct gotd_imsgev *iev = arg;
1121 	struct imsgbuf *ibuf = &iev->ibuf;
1122 	struct gotd_client *client;
1123 	struct gotd_repo *repo = NULL;
1124 	ssize_t n;
1125 	int shut = 0;
1126 	struct imsg imsg;
1127 	uint32_t client_id = 0;
1128 	int do_disconnect = 0;
1129 
1130 	client = find_client_by_proc_fd(fd);
1131 	if (client == NULL) {
1132 		/* Can happen during process teardown. */
1133 		warnx("cannot find client for fd %d", fd);
1134 		shut = 1;
1135 		goto done;
1136 	}
1137 
1138 	if (client->auth == NULL)
1139 		fatalx("cannot find auth child process for fd %d", fd);
1140 
1141 	if (event & EV_READ) {
1142 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1143 			fatal("imsg_read error");
1144 		if (n == 0) {
1145 			/* Connection closed. */
1146 			shut = 1;
1147 			goto done;
1148 		}
1149 	}
1150 
1151 	if (event & EV_WRITE) {
1152 		n = msgbuf_write(&ibuf->w);
1153 		if (n == -1 && errno != EAGAIN)
1154 			fatal("msgbuf_write");
1155 		if (n == 0) {
1156 			/* Connection closed. */
1157 			shut = 1;
1158 		}
1159 		goto done;
1160 	}
1161 
1162 	if (client->auth->iev.ibuf.fd != fd)
1163 		fatalx("%s: unexpected fd %d", __func__, fd);
1164 
1165 	if ((n = imsg_get(ibuf, &imsg)) == -1)
1166 		fatal("%s: imsg_get error", __func__);
1167 	if (n == 0)	/* No more messages. */
1168 		return;
1169 
1170 	evtimer_del(&client->tmo);
1171 
1172 	switch (imsg.hdr.type) {
1173 	case GOTD_IMSG_ERROR:
1174 		do_disconnect = 1;
1175 		err = gotd_imsg_recv_error(&client_id, &imsg);
1176 		break;
1177 	case GOTD_IMSG_ACCESS_GRANTED:
1178 		client->state = GOTD_CLIENT_STATE_ACCESS_GRANTED;
1179 		break;
1180 	default:
1181 		do_disconnect = 1;
1182 		log_debug("unexpected imsg %d", imsg.hdr.type);
1183 		break;
1184 	}
1185 
1186 	if (!verify_imsg_src(client, client->auth, &imsg)) {
1187 		do_disconnect = 1;
1188 		log_debug("dropping imsg type %d from PID %d",
1189 		    imsg.hdr.type, client->auth->pid);
1190 	}
1191 	imsg_free(&imsg);
1192 
1193 	if (do_disconnect) {
1194 		if (err)
1195 			disconnect_on_error(client, err);
1196 		else
1197 			disconnect(client);
1198 		return;
1199 	}
1200 
1201 	repo = gotd_find_repo_by_name(client->auth->repo_name, &gotd);
1202 	if (repo == NULL) {
1203 		err = got_error(GOT_ERR_NOT_GIT_REPO);
1204 		goto done;
1205 	}
1206 	kill_auth_proc(client);
1207 
1208 	log_info("authenticated uid %d for repository %s",
1209 	    client->euid, repo->name);
1210 
1211 	err = start_session_child(client, repo, gotd.argv0,
1212 	    gotd.confpath, gotd.daemonize, gotd.verbosity);
1213 	if (err)
1214 		goto done;
1215 done:
1216 	if (err)
1217 		log_warnx("uid %d: %s", client->euid, err->msg);
1218 
1219 	/* We might have killed the auth process by now. */
1220 	if (client->auth != NULL) {
1221 		if (!shut) {
1222 			gotd_imsg_event_add(iev);
1223 		} else {
1224 			/* This pipe is dead. Remove its event handler */
1225 			event_del(&iev->ev);
1226 		}
1227 	}
1228 }
1229 
1230 static const struct got_error *
1231 connect_session(struct gotd_client *client)
1232 {
1233 	const struct got_error *err = NULL;
1234 	struct gotd_imsg_connect iconnect;
1235 	int s;
1236 
1237 	memset(&iconnect, 0, sizeof(iconnect));
1238 
1239 	s = dup(client->fd);
1240 	if (s == -1)
1241 		return got_error_from_errno("dup");
1242 
1243 	iconnect.client_id = client->id;
1244 	iconnect.euid = client->euid;
1245 	iconnect.egid = client->egid;
1246 
1247 	if (gotd_imsg_compose_event(&client->session->iev, GOTD_IMSG_CONNECT,
1248 	    PROC_GOTD, s, &iconnect, sizeof(iconnect)) == -1) {
1249 		err = got_error_from_errno("imsg compose CONNECT");
1250 		close(s);
1251 		return err;
1252 	}
1253 
1254 	/*
1255 	 * We are no longer interested in messages from this client.
1256 	 * Further client requests will be handled by the session process.
1257 	 */
1258 	msgbuf_clear(&client->iev.ibuf.w);
1259 	imsg_clear(&client->iev.ibuf);
1260 	event_del(&client->iev.ev);
1261 	client->fd = -1; /* will be closed via copy in client->iev.ibuf.fd */
1262 
1263 	return NULL;
1264 }
1265 
1266 static void
1267 gotd_dispatch_client_session(int fd, short event, void *arg)
1268 {
1269 	struct gotd_imsgev *iev = arg;
1270 	struct imsgbuf *ibuf = &iev->ibuf;
1271 	struct gotd_child_proc *proc = NULL;
1272 	struct gotd_client *client = NULL;
1273 	ssize_t n;
1274 	int shut = 0;
1275 	struct imsg imsg;
1276 
1277 	client = find_client_by_proc_fd(fd);
1278 	if (client == NULL) {
1279 		/* Can happen during process teardown. */
1280 		warnx("cannot find client for fd %d", fd);
1281 		shut = 1;
1282 		goto done;
1283 	}
1284 
1285 	if (event & EV_READ) {
1286 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1287 			fatal("imsg_read error");
1288 		if (n == 0) {
1289 			/* Connection closed. */
1290 			shut = 1;
1291 			goto done;
1292 		}
1293 	}
1294 
1295 	if (event & EV_WRITE) {
1296 		n = msgbuf_write(&ibuf->w);
1297 		if (n == -1 && errno != EAGAIN)
1298 			fatal("msgbuf_write");
1299 		if (n == 0) {
1300 			/* Connection closed. */
1301 			shut = 1;
1302 			goto done;
1303 		}
1304 	}
1305 
1306 	proc = client->session;
1307 	if (proc == NULL)
1308 		fatalx("cannot find session child process for fd %d", fd);
1309 
1310 	for (;;) {
1311 		const struct got_error *err = NULL;
1312 		uint32_t client_id = 0;
1313 		int do_disconnect = 0, do_start_repo_child = 0;
1314 
1315 		if ((n = imsg_get(ibuf, &imsg)) == -1)
1316 			fatal("%s: imsg_get error", __func__);
1317 		if (n == 0)	/* No more messages. */
1318 			break;
1319 
1320 		switch (imsg.hdr.type) {
1321 		case GOTD_IMSG_ERROR:
1322 			do_disconnect = 1;
1323 			err = gotd_imsg_recv_error(&client_id, &imsg);
1324 			break;
1325 		case GOTD_IMSG_CLIENT_SESSION_READY:
1326 			if (client->state != GOTD_CLIENT_STATE_ACCESS_GRANTED) {
1327 				err = got_error(GOT_ERR_PRIVSEP_MSG);
1328 				break;
1329 			}
1330 			do_start_repo_child = 1;
1331 			break;
1332 		case GOTD_IMSG_DISCONNECT:
1333 			do_disconnect = 1;
1334 			break;
1335 		default:
1336 			log_debug("unexpected imsg %d", imsg.hdr.type);
1337 			break;
1338 		}
1339 
1340 		if (!verify_imsg_src(client, proc, &imsg)) {
1341 			log_debug("dropping imsg type %d from PID %d",
1342 			    imsg.hdr.type, proc->pid);
1343 			imsg_free(&imsg);
1344 			continue;
1345 		}
1346 		if (err)
1347 			log_warnx("uid %d: %s", client->euid, err->msg);
1348 
1349 		if (do_start_repo_child) {
1350 			struct gotd_repo *repo;
1351 			const char *name = client->session->repo_name;
1352 
1353 			repo = gotd_find_repo_by_name(name, &gotd);
1354 			if (repo != NULL) {
1355 				enum gotd_procid proc_type;
1356 
1357 				if (client->required_auth & GOTD_AUTH_WRITE)
1358 					proc_type = PROC_REPO_WRITE;
1359 				else
1360 					proc_type = PROC_REPO_READ;
1361 
1362 				err = start_repo_child(client, proc_type, repo,
1363 				    gotd.argv0, gotd.confpath, gotd.daemonize,
1364 				    gotd.verbosity);
1365 			} else
1366 				err = got_error(GOT_ERR_NOT_GIT_REPO);
1367 
1368 			if (err) {
1369 				log_warnx("uid %d: %s", client->euid, err->msg);
1370 				do_disconnect = 1;
1371 			}
1372 		}
1373 
1374 		if (do_disconnect) {
1375 			if (err)
1376 				disconnect_on_error(client, err);
1377 			else
1378 				disconnect(client);
1379 		}
1380 
1381 		imsg_free(&imsg);
1382 	}
1383 done:
1384 	if (!shut) {
1385 		gotd_imsg_event_add(iev);
1386 	} else {
1387 		/* This pipe is dead. Remove its event handler */
1388 		event_del(&iev->ev);
1389 		disconnect(client);
1390 	}
1391 }
1392 
1393 static void
1394 gotd_dispatch_repo_child(int fd, short event, void *arg)
1395 {
1396 	struct gotd_imsgev *iev = arg;
1397 	struct imsgbuf *ibuf = &iev->ibuf;
1398 	struct gotd_child_proc *proc = NULL;
1399 	struct gotd_client *client;
1400 	ssize_t n;
1401 	int shut = 0;
1402 	struct imsg imsg;
1403 
1404 	client = find_client_by_proc_fd(fd);
1405 	if (client == NULL) {
1406 		/* Can happen during process teardown. */
1407 		warnx("cannot find client for fd %d", fd);
1408 		shut = 1;
1409 		goto done;
1410 	}
1411 
1412 	if (event & EV_READ) {
1413 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1414 			fatal("imsg_read error");
1415 		if (n == 0) {
1416 			/* Connection closed. */
1417 			shut = 1;
1418 			goto done;
1419 		}
1420 	}
1421 
1422 	if (event & EV_WRITE) {
1423 		n = msgbuf_write(&ibuf->w);
1424 		if (n == -1 && errno != EAGAIN)
1425 			fatal("msgbuf_write");
1426 		if (n == 0) {
1427 			/* Connection closed. */
1428 			shut = 1;
1429 			goto done;
1430 		}
1431 	}
1432 
1433 	proc = client->repo;
1434 	if (proc == NULL)
1435 		fatalx("cannot find child process for fd %d", fd);
1436 
1437 	for (;;) {
1438 		const struct got_error *err = NULL;
1439 		uint32_t client_id = 0;
1440 		int do_disconnect = 0;
1441 
1442 		if ((n = imsg_get(ibuf, &imsg)) == -1)
1443 			fatal("%s: imsg_get error", __func__);
1444 		if (n == 0)	/* No more messages. */
1445 			break;
1446 
1447 		switch (imsg.hdr.type) {
1448 		case GOTD_IMSG_ERROR:
1449 			do_disconnect = 1;
1450 			err = gotd_imsg_recv_error(&client_id, &imsg);
1451 			break;
1452 		case GOTD_IMSG_REPO_CHILD_READY:
1453 			err = connect_session(client);
1454 			if (err)
1455 				break;
1456 			err = connect_repo_child(client, proc);
1457 			break;
1458 		default:
1459 			log_debug("unexpected imsg %d", imsg.hdr.type);
1460 			break;
1461 		}
1462 
1463 		if (!verify_imsg_src(client, proc, &imsg)) {
1464 			log_debug("dropping imsg type %d from PID %d",
1465 			    imsg.hdr.type, proc->pid);
1466 			imsg_free(&imsg);
1467 			continue;
1468 		}
1469 		if (err)
1470 			log_warnx("uid %d: %s", client->euid, err->msg);
1471 
1472 		if (do_disconnect) {
1473 			if (err)
1474 				disconnect_on_error(client, err);
1475 			else
1476 				disconnect(client);
1477 		}
1478 
1479 		imsg_free(&imsg);
1480 	}
1481 done:
1482 	if (!shut) {
1483 		gotd_imsg_event_add(iev);
1484 	} else {
1485 		/* This pipe is dead. Remove its event handler */
1486 		event_del(&iev->ev);
1487 		disconnect(client);
1488 	}
1489 }
1490 
1491 static pid_t
1492 start_child(enum gotd_procid proc_id, const char *repo_path,
1493     char *argv0, const char *confpath, int fd, int daemonize, int verbosity)
1494 {
1495 	char	*argv[11];
1496 	int	 argc = 0;
1497 	pid_t	 pid;
1498 
1499 	switch (pid = fork()) {
1500 	case -1:
1501 		fatal("cannot fork");
1502 	case 0:
1503 		break;
1504 	default:
1505 		close(fd);
1506 		return pid;
1507 	}
1508 
1509 	if (fd != GOTD_FILENO_MSG_PIPE) {
1510 		if (dup2(fd, GOTD_FILENO_MSG_PIPE) == -1)
1511 			fatal("cannot setup imsg fd");
1512 	} else if (fcntl(fd, F_SETFD, 0) == -1)
1513 		fatal("cannot setup imsg fd");
1514 
1515 	argv[argc++] = argv0;
1516 	switch (proc_id) {
1517 	case PROC_LISTEN:
1518 		argv[argc++] = (char *)"-L";
1519 		break;
1520 	case PROC_AUTH:
1521 		argv[argc++] = (char *)"-A";
1522 		break;
1523 	case PROC_SESSION_READ:
1524 		argv[argc++] = (char *)"-s";
1525 		break;
1526 	case PROC_SESSION_WRITE:
1527 		argv[argc++] = (char *)"-S";
1528 		break;
1529 	case PROC_REPO_READ:
1530 		argv[argc++] = (char *)"-R";
1531 		break;
1532 	case PROC_REPO_WRITE:
1533 		argv[argc++] = (char *)"-W";
1534 		break;
1535 	default:
1536 		fatalx("invalid process id %d", proc_id);
1537 	}
1538 
1539 	argv[argc++] = (char *)"-f";
1540 	argv[argc++] = (char *)confpath;
1541 
1542 	if (repo_path) {
1543 		argv[argc++] = (char *)"-P";
1544 		argv[argc++] = (char *)repo_path;
1545 	}
1546 
1547 	if (!daemonize)
1548 		argv[argc++] = (char *)"-d";
1549 	if (verbosity > 0)
1550 		argv[argc++] = (char *)"-v";
1551 	if (verbosity > 1)
1552 		argv[argc++] = (char *)"-v";
1553 	argv[argc++] = NULL;
1554 
1555 	execvp(argv0, argv);
1556 	fatal("execvp");
1557 }
1558 
1559 static void
1560 start_listener(char *argv0, const char *confpath, int daemonize, int verbosity)
1561 {
1562 	struct gotd_child_proc *proc;
1563 
1564 	proc = calloc(1, sizeof(*proc));
1565 	if (proc == NULL)
1566 		fatal("calloc");
1567 
1568 	TAILQ_INSERT_HEAD(&procs, proc, entry);
1569 
1570 	/* proc->tmo is initialized in main() after event_init() */
1571 
1572 	proc->type = PROC_LISTEN;
1573 
1574 	if (socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK,
1575 	    PF_UNSPEC, proc->pipe) == -1)
1576 		fatal("socketpair");
1577 
1578 	proc->pid = start_child(proc->type, NULL, argv0, confpath,
1579 	    proc->pipe[1], daemonize, verbosity);
1580 	imsg_init(&proc->iev.ibuf, proc->pipe[0]);
1581 	proc->iev.handler = gotd_dispatch_listener;
1582 	proc->iev.events = EV_READ;
1583 	proc->iev.handler_arg = NULL;
1584 
1585 	gotd.listen_proc = proc;
1586 }
1587 
1588 static const struct got_error *
1589 start_session_child(struct gotd_client *client, struct gotd_repo *repo,
1590     char *argv0, const char *confpath, int daemonize, int verbosity)
1591 {
1592 	struct gotd_child_proc *proc;
1593 
1594 	proc = calloc(1, sizeof(*proc));
1595 	if (proc == NULL)
1596 		return got_error_from_errno("calloc");
1597 
1598 	TAILQ_INSERT_HEAD(&procs, proc, entry);
1599 	evtimer_set(&proc->tmo, kill_proc_timeout, proc);
1600 
1601 	if (client_is_reading(client))
1602 		proc->type = PROC_SESSION_READ;
1603 	else
1604 		proc->type = PROC_SESSION_WRITE;
1605 	if (strlcpy(proc->repo_name, repo->name,
1606 	    sizeof(proc->repo_name)) >= sizeof(proc->repo_name))
1607 		fatalx("repository name too long: %s", repo->name);
1608 	log_debug("starting client uid %d session for repository %s",
1609 	    client->euid, repo->name);
1610 	if (strlcpy(proc->repo_path, repo->path, sizeof(proc->repo_path)) >=
1611 	    sizeof(proc->repo_path))
1612 		fatalx("repository path too long: %s", repo->path);
1613 	if (socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK,
1614 	    PF_UNSPEC, proc->pipe) == -1)
1615 		fatal("socketpair");
1616 	proc->pid = start_child(proc->type, proc->repo_path, argv0,
1617 	    confpath, proc->pipe[1], daemonize, verbosity);
1618 	imsg_init(&proc->iev.ibuf, proc->pipe[0]);
1619 	log_debug("proc %s %s is on fd %d",
1620 	    gotd_proc_names[proc->type], proc->repo_path,
1621 	    proc->pipe[0]);
1622 	proc->iev.handler = gotd_dispatch_client_session;
1623 	proc->iev.events = EV_READ;
1624 	proc->iev.handler_arg = NULL;
1625 	event_set(&proc->iev.ev, proc->iev.ibuf.fd, EV_READ,
1626 	    gotd_dispatch_client_session, &proc->iev);
1627 	gotd_imsg_event_add(&proc->iev);
1628 
1629 	client->session = proc;
1630 	return NULL;
1631 }
1632 
1633 static const struct got_error *
1634 start_repo_child(struct gotd_client *client, enum gotd_procid proc_type,
1635     struct gotd_repo *repo, char *argv0, const char *confpath,
1636     int daemonize, int verbosity)
1637 {
1638 	struct gotd_child_proc *proc;
1639 
1640 	if (proc_type != PROC_REPO_READ && proc_type != PROC_REPO_WRITE)
1641 		return got_error_msg(GOT_ERR_NOT_IMPL, "bad process type");
1642 
1643 	proc = calloc(1, sizeof(*proc));
1644 	if (proc == NULL)
1645 		return got_error_from_errno("calloc");
1646 
1647 	TAILQ_INSERT_HEAD(&procs, proc, entry);
1648 	evtimer_set(&proc->tmo, kill_proc_timeout, proc);
1649 
1650 	proc->type = proc_type;
1651 	if (strlcpy(proc->repo_name, repo->name,
1652 	    sizeof(proc->repo_name)) >= sizeof(proc->repo_name))
1653 		fatalx("repository name too long: %s", repo->name);
1654 	log_debug("starting %s for repository %s",
1655 	    proc->type == PROC_REPO_READ ? "reader" : "writer", repo->name);
1656 	if (strlcpy(proc->repo_path, repo->path, sizeof(proc->repo_path)) >=
1657 	    sizeof(proc->repo_path))
1658 		fatalx("repository path too long: %s", repo->path);
1659 	if (socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK,
1660 	    PF_UNSPEC, proc->pipe) == -1)
1661 		fatal("socketpair");
1662 	proc->pid = start_child(proc->type, proc->repo_path, argv0,
1663 	    confpath, proc->pipe[1], daemonize, verbosity);
1664 	imsg_init(&proc->iev.ibuf, proc->pipe[0]);
1665 	log_debug("proc %s %s is on fd %d",
1666 	    gotd_proc_names[proc->type], proc->repo_path,
1667 	    proc->pipe[0]);
1668 	proc->iev.handler = gotd_dispatch_repo_child;
1669 	proc->iev.events = EV_READ;
1670 	proc->iev.handler_arg = NULL;
1671 	event_set(&proc->iev.ev, proc->iev.ibuf.fd, EV_READ,
1672 	    gotd_dispatch_repo_child, &proc->iev);
1673 	gotd_imsg_event_add(&proc->iev);
1674 
1675 	client->repo = proc;
1676 	return NULL;
1677 }
1678 
1679 static const struct got_error *
1680 start_auth_child(struct gotd_client *client, int required_auth,
1681     struct gotd_repo *repo, char *argv0, const char *confpath,
1682     int daemonize, int verbosity)
1683 {
1684 	const struct got_error *err = NULL;
1685 	struct gotd_child_proc *proc;
1686 	struct gotd_imsg_auth iauth;
1687 	int fd;
1688 
1689 	memset(&iauth, 0, sizeof(iauth));
1690 
1691 	fd = dup(client->fd);
1692 	if (fd == -1)
1693 		return got_error_from_errno("dup");
1694 
1695 	proc = calloc(1, sizeof(*proc));
1696 	if (proc == NULL) {
1697 		err = got_error_from_errno("calloc");
1698 		close(fd);
1699 		return err;
1700 	}
1701 
1702 	TAILQ_INSERT_HEAD(&procs, proc, entry);
1703 	evtimer_set(&proc->tmo, kill_proc_timeout, proc);
1704 
1705 	proc->type = PROC_AUTH;
1706 	if (strlcpy(proc->repo_name, repo->name,
1707 	    sizeof(proc->repo_name)) >= sizeof(proc->repo_name))
1708 		fatalx("repository name too long: %s", repo->name);
1709 	log_debug("starting auth for uid %d repository %s",
1710 	    client->euid, repo->name);
1711 	if (strlcpy(proc->repo_path, repo->path, sizeof(proc->repo_path)) >=
1712 	    sizeof(proc->repo_path))
1713 		fatalx("repository path too long: %s", repo->path);
1714 	if (socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK,
1715 	    PF_UNSPEC, proc->pipe) == -1)
1716 		fatal("socketpair");
1717 	proc->pid = start_child(proc->type, proc->repo_path, argv0,
1718 	    confpath, proc->pipe[1], daemonize, verbosity);
1719 	imsg_init(&proc->iev.ibuf, proc->pipe[0]);
1720 	log_debug("proc %s %s is on fd %d",
1721 	    gotd_proc_names[proc->type], proc->repo_path,
1722 	    proc->pipe[0]);
1723 	proc->iev.handler = gotd_dispatch_auth_child;
1724 	proc->iev.events = EV_READ;
1725 	proc->iev.handler_arg = NULL;
1726 	event_set(&proc->iev.ev, proc->iev.ibuf.fd, EV_READ,
1727 	    gotd_dispatch_auth_child, &proc->iev);
1728 	gotd_imsg_event_add(&proc->iev);
1729 
1730 	iauth.euid = client->euid;
1731 	iauth.egid = client->egid;
1732 	iauth.required_auth = required_auth;
1733 	iauth.client_id = client->id;
1734 	if (gotd_imsg_compose_event(&proc->iev, GOTD_IMSG_AUTHENTICATE,
1735 	    PROC_GOTD, fd, &iauth, sizeof(iauth)) == -1) {
1736 		log_warn("imsg compose AUTHENTICATE");
1737 		close(fd);
1738 		/* Let the auth_timeout handler tidy up. */
1739 	}
1740 
1741 	client->auth = proc;
1742 	client->required_auth = required_auth;
1743 	return NULL;
1744 }
1745 
1746 static void
1747 apply_unveil_repo_readonly(const char *repo_path, int need_tmpdir)
1748 {
1749 	if (need_tmpdir) {
1750 		if (unveil(GOT_TMPDIR_STR, "rwc") == -1)
1751 			fatal("unveil %s", GOT_TMPDIR_STR);
1752 	}
1753 
1754 	if (unveil(repo_path, "r") == -1)
1755 		fatal("unveil %s", repo_path);
1756 
1757 	if (unveil(NULL, NULL) == -1)
1758 		fatal("unveil");
1759 }
1760 
1761 static void
1762 apply_unveil_repo_readwrite(const char *repo_path)
1763 {
1764 	if (unveil(repo_path, "rwc") == -1)
1765 		fatal("unveil %s", repo_path);
1766 
1767 	if (unveil(GOT_TMPDIR_STR, "rwc") == -1)
1768 		fatal("unveil %s", GOT_TMPDIR_STR);
1769 
1770 	if (unveil(NULL, NULL) == -1)
1771 		fatal("unveil");
1772 }
1773 
1774 static void
1775 apply_unveil_none(void)
1776 {
1777 	if (unveil("/", "") == -1)
1778 		fatal("unveil");
1779 
1780 	if (unveil(NULL, NULL) == -1)
1781 		fatal("unveil");
1782 }
1783 
1784 static void
1785 apply_unveil_selfexec(void)
1786 {
1787 	if (unveil(gotd.argv0, "x") == -1)
1788 		fatal("unveil %s", gotd.argv0);
1789 
1790 	if (unveil(NULL, NULL) == -1)
1791 		fatal("unveil");
1792 }
1793 
1794 static void
1795 set_max_datasize(void)
1796 {
1797 	struct rlimit rl;
1798 
1799 	if (getrlimit(RLIMIT_DATA, &rl) != 0)
1800 		return;
1801 
1802 	rl.rlim_cur = rl.rlim_max;
1803 	setrlimit(RLIMIT_DATA, &rl);
1804 }
1805 
1806 int
1807 main(int argc, char **argv)
1808 {
1809 	const struct got_error *error = NULL;
1810 	int ch, fd = -1, daemonize = 1, verbosity = 0, noaction = 0;
1811 	const char *confpath = GOTD_CONF_PATH;
1812 	char *argv0 = argv[0];
1813 	char title[2048];
1814 	struct passwd *pw = NULL;
1815 	char *repo_path = NULL;
1816 	enum gotd_procid proc_id = PROC_GOTD;
1817 	struct event evsigint, evsigterm, evsighup, evsigusr1, evsigchld;
1818 	int *pack_fds = NULL, *temp_fds = NULL;
1819 	struct gotd_repo *repo = NULL;
1820 
1821 	TAILQ_INIT(&procs);
1822 
1823 	log_init(1, LOG_DAEMON); /* Log to stderr until daemonized. */
1824 
1825 	while ((ch = getopt(argc, argv, "Adf:LnP:RsSvW")) != -1) {
1826 		switch (ch) {
1827 		case 'A':
1828 			proc_id = PROC_AUTH;
1829 			break;
1830 		case 'd':
1831 			daemonize = 0;
1832 			break;
1833 		case 'f':
1834 			confpath = optarg;
1835 			break;
1836 		case 'L':
1837 			proc_id = PROC_LISTEN;
1838 			break;
1839 		case 'n':
1840 			noaction = 1;
1841 			break;
1842 		case 'P':
1843 			repo_path = realpath(optarg, NULL);
1844 			if (repo_path == NULL)
1845 				fatal("realpath '%s'", optarg);
1846 			break;
1847 		case 'R':
1848 			proc_id = PROC_REPO_READ;
1849 			break;
1850 		case 's':
1851 			proc_id = PROC_SESSION_READ;
1852 			break;
1853 		case 'S':
1854 			proc_id = PROC_SESSION_WRITE;
1855 			break;
1856 		case 'v':
1857 			if (verbosity < 3)
1858 				verbosity++;
1859 			break;
1860 		case 'W':
1861 			proc_id = PROC_REPO_WRITE;
1862 			break;
1863 		default:
1864 			usage();
1865 		}
1866 	}
1867 
1868 	argc -= optind;
1869 	argv += optind;
1870 
1871 	if (argc != 0)
1872 		usage();
1873 
1874 	if (geteuid() && (proc_id == PROC_GOTD || proc_id == PROC_LISTEN))
1875 		fatalx("need root privileges");
1876 
1877 	if (parse_config(confpath, proc_id, &gotd) != 0)
1878 		return 1;
1879 
1880 	pw = getpwnam(gotd.user_name);
1881 	if (pw == NULL)
1882 		fatalx("user %s not found", gotd.user_name);
1883 
1884 	if (pw->pw_uid == 0)
1885 		fatalx("cannot run %s as the superuser", getprogname());
1886 
1887 	if (noaction) {
1888 		fprintf(stderr, "configuration OK\n");
1889 		return 0;
1890 	}
1891 
1892 	gotd.argv0 = argv0;
1893 	gotd.daemonize = daemonize;
1894 	gotd.verbosity = verbosity;
1895 	gotd.confpath = confpath;
1896 
1897 	/* Require an absolute path in argv[0] for reliable re-exec. */
1898 	if (!got_path_is_absolute(argv0))
1899 		fatalx("bad path \"%s\": must be an absolute path", argv0);
1900 
1901 	log_init(daemonize ? 0 : 1, LOG_DAEMON);
1902 	log_setverbose(verbosity);
1903 
1904 	if (proc_id == PROC_GOTD) {
1905 		snprintf(title, sizeof(title), "%s", gotd_proc_names[proc_id]);
1906 		arc4random_buf(&clients_hash_key, sizeof(clients_hash_key));
1907 		if (daemonize && daemon(1, 0) == -1)
1908 			fatal("daemon");
1909 		gotd.pid = getpid();
1910 		start_listener(argv0, confpath, daemonize, verbosity);
1911 	} else if (proc_id == PROC_LISTEN) {
1912 		snprintf(title, sizeof(title), "%s", gotd_proc_names[proc_id]);
1913 		if (verbosity) {
1914 			log_info("socket: %s", gotd.unix_socket_path);
1915 			log_info("user: %s", pw->pw_name);
1916 		}
1917 
1918 		fd = unix_socket_listen(gotd.unix_socket_path, pw->pw_uid,
1919 		    pw->pw_gid);
1920 		if (fd == -1) {
1921 			fatal("cannot listen on unix socket %s",
1922 			    gotd.unix_socket_path);
1923 		}
1924 	} else if (proc_id == PROC_AUTH) {
1925 		snprintf(title, sizeof(title), "%s %s",
1926 		    gotd_proc_names[proc_id], repo_path);
1927 	} else if (proc_id == PROC_REPO_READ || proc_id == PROC_REPO_WRITE ||
1928 	    proc_id == PROC_SESSION_READ || proc_id == PROC_SESSION_WRITE) {
1929 		error = got_repo_pack_fds_open(&pack_fds);
1930 		if (error != NULL)
1931 			fatalx("cannot open pack tempfiles: %s", error->msg);
1932 		error = got_repo_temp_fds_open(&temp_fds);
1933 		if (error != NULL)
1934 			fatalx("cannot open pack tempfiles: %s", error->msg);
1935 		if (repo_path == NULL)
1936 			fatalx("repository path not specified");
1937 		snprintf(title, sizeof(title), "%s %s",
1938 		    gotd_proc_names[proc_id], repo_path);
1939 	} else
1940 		fatal("invalid process id %d", proc_id);
1941 
1942 	setproctitle("%s", title);
1943 	log_procinit(title);
1944 
1945 	/* Drop root privileges. */
1946 	if (setgid(pw->pw_gid) == -1)
1947 		fatal("setgid %d failed", pw->pw_gid);
1948 	if (setuid(pw->pw_uid) == -1)
1949 		fatal("setuid %d failed", pw->pw_uid);
1950 
1951 	event_init();
1952 
1953 	switch (proc_id) {
1954 	case PROC_GOTD:
1955 #ifndef PROFILE
1956 		/* "exec" promise will be limited to argv[0] via unveil(2). */
1957 		if (pledge("stdio proc exec sendfd recvfd unveil", NULL) == -1)
1958 			err(1, "pledge");
1959 #endif
1960 		break;
1961 	case PROC_LISTEN:
1962 #ifndef PROFILE
1963 		if (pledge("stdio sendfd unix unveil", NULL) == -1)
1964 			err(1, "pledge");
1965 #endif
1966 		/*
1967 		 * Ensure that AF_UNIX bind(2) cannot be used with any other
1968 		 * sockets by revoking all filesystem access via unveil(2).
1969 		 */
1970 		apply_unveil_none();
1971 
1972 		listen_main(title, fd, gotd.connection_limits,
1973 		    gotd.nconnection_limits);
1974 		/* NOTREACHED */
1975 		break;
1976 	case PROC_AUTH:
1977 #ifndef PROFILE
1978 		if (pledge("stdio getpw recvfd unix unveil", NULL) == -1)
1979 			err(1, "pledge");
1980 #endif
1981 		/*
1982 		 * We need the "unix" pledge promise for getpeername(2) only.
1983 		 * Ensure that AF_UNIX bind(2) cannot be used by revoking all
1984 		 * filesystem access via unveil(2). Access to password database
1985 		 * files will still work since "getpw" bypasses unveil(2).
1986 		 */
1987 		apply_unveil_none();
1988 
1989 		auth_main(title, &gotd.repos, repo_path);
1990 		/* NOTREACHED */
1991 		break;
1992 	case PROC_SESSION_READ:
1993 	case PROC_SESSION_WRITE:
1994 #ifndef PROFILE
1995 		/*
1996 		 * The "recvfd" promise is only needed during setup and
1997 		 * will be removed in a later pledge(2) call.
1998 		 */
1999 		if (pledge("stdio rpath wpath cpath recvfd sendfd fattr flock "
2000 		    "unveil", NULL) == -1)
2001 			err(1, "pledge");
2002 #endif
2003 		if (proc_id == PROC_SESSION_READ)
2004 			apply_unveil_repo_readonly(repo_path, 1);
2005 		else
2006 			apply_unveil_repo_readwrite(repo_path);
2007 		session_main(title, repo_path, pack_fds, temp_fds,
2008 		    &gotd.request_timeout, proc_id);
2009 		/* NOTREACHED */
2010 		break;
2011 	case PROC_REPO_READ:
2012 		set_max_datasize();
2013 #ifndef PROFILE
2014 		if (pledge("stdio rpath recvfd unveil", NULL) == -1)
2015 			err(1, "pledge");
2016 #endif
2017 		apply_unveil_repo_readonly(repo_path, 0);
2018 		repo_read_main(title, repo_path, pack_fds, temp_fds);
2019 		/* NOTREACHED */
2020 		exit(0);
2021 	case PROC_REPO_WRITE:
2022 		set_max_datasize();
2023 #ifndef PROFILE
2024 		if (pledge("stdio rpath recvfd unveil", NULL) == -1)
2025 			err(1, "pledge");
2026 #endif
2027 		apply_unveil_repo_readonly(repo_path, 0);
2028 		repo = gotd_find_repo_by_path(repo_path, &gotd);
2029 		if (repo == NULL)
2030 			fatalx("no repository for path %s", repo_path);
2031 		repo_write_main(title, repo_path, pack_fds, temp_fds,
2032 		    &repo->protected_tag_namespaces,
2033 		    &repo->protected_branch_namespaces,
2034 		    &repo->protected_branches);
2035 		/* NOTREACHED */
2036 		exit(0);
2037 	default:
2038 		fatal("invalid process id %d", proc_id);
2039 	}
2040 
2041 	if (proc_id != PROC_GOTD)
2042 		fatal("invalid process id %d", proc_id);
2043 
2044 	evtimer_set(&gotd.listen_proc->tmo, kill_proc_timeout,
2045 	    gotd.listen_proc);
2046 
2047 	apply_unveil_selfexec();
2048 
2049 	signal_set(&evsigint, SIGINT, gotd_sighdlr, NULL);
2050 	signal_set(&evsigterm, SIGTERM, gotd_sighdlr, NULL);
2051 	signal_set(&evsighup, SIGHUP, gotd_sighdlr, NULL);
2052 	signal_set(&evsigusr1, SIGUSR1, gotd_sighdlr, NULL);
2053 	signal_set(&evsigchld, SIGCHLD, gotd_sighdlr, NULL);
2054 	signal(SIGPIPE, SIG_IGN);
2055 
2056 	signal_add(&evsigint, NULL);
2057 	signal_add(&evsigterm, NULL);
2058 	signal_add(&evsighup, NULL);
2059 	signal_add(&evsigusr1, NULL);
2060 	signal_add(&evsigchld, NULL);
2061 
2062 	gotd_imsg_event_add(&gotd.listen_proc->iev);
2063 
2064 	event_dispatch();
2065 
2066 	free(repo_path);
2067 	gotd_shutdown();
2068 
2069 	return 0;
2070 }