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 "got_compat.h"
18 
19 #include <sys/queue.h>
20 #include <sys/time.h>
21 #include <sys/types.h>
22 #include <sys/stat.h>
23 #include <sys/socket.h>
24 #include <sys/un.h>
25 #include <sys/wait.h>
26 #include <sys/resource.h>
27 
28 #include <fcntl.h>
29 #include <err.h>
30 #include <errno.h>
31 #include <event.h>
32 #include <limits.h>
33 #include <pwd.h>
34 #include <imsg.h>
35 #include <signal.h>
36 #include <stdarg.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #include <syslog.h>
41 #include <unistd.h>
42 
43 #include "got_error.h"
44 #include "got_opentemp.h"
45 #include "got_path.h"
46 #include "got_repository.h"
47 #include "got_object.h"
48 #include "got_reference.h"
49 
50 #include "got_lib_delta.h"
51 #include "got_lib_object.h"
52 #include "got_lib_object_cache.h"
53 #include "got_lib_hash.h"
54 #include "got_lib_gitproto.h"
55 #include "got_lib_pack.h"
56 #include "got_lib_repository.h"
57 
58 #include "gotd.h"
59 #include "log.h"
60 #include "listen.h"
61 #include "auth.h"
62 #include "session.h"
63 #include "repo_read.h"
64 #include "repo_write.h"
65 
66 #ifndef nitems
67 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
68 #endif
69 
70 enum gotd_client_state {
71 	GOTD_CLIENT_STATE_NEW,
72 	GOTD_CLIENT_STATE_ACCESS_GRANTED,
73 };
74 
75 struct gotd_child_proc {
76 	pid_t				 pid;
77 	enum gotd_procid		 type;
78 	char				 repo_name[NAME_MAX];
79 	char				 repo_path[PATH_MAX];
80 	int				 pipe[2];
81 	struct gotd_imsgev		 iev;
82 	struct event			 tmo;
83 
84 	TAILQ_ENTRY(gotd_child_proc)	 entry;
85 };
86 TAILQ_HEAD(gotd_procs, gotd_child_proc) procs;
87 
88 struct gotd_client {
89 	STAILQ_ENTRY(gotd_client)	 entry;
90 	enum gotd_client_state		 state;
91 	uint32_t			 id;
92 	int				 fd;
93 	struct gotd_imsgev		 iev;
94 	struct event			 tmo;
95 	uid_t				 euid;
96 	gid_t				 egid;
97 	char				*username;
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 static void drop_privs(struct passwd *);
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 void
131 drop_privs(struct passwd *pw)
132 {
133 	/* Drop root privileges. */
134 	if (setgid(pw->pw_gid) == -1)
135 		fatal("setgid %d failed", pw->pw_gid);
136 	if (setuid(pw->pw_uid) == -1)
137 		fatal("setuid %d failed", pw->pw_uid);
138 }
139 
140 static int
141 unix_socket_listen(const char *unix_socket_path, uid_t uid, gid_t gid)
142 {
143 	struct sockaddr_un sun;
144 	int fd = -1;
145 	mode_t old_umask, mode;
146 	int sock_flags = SOCK_STREAM | SOCK_NONBLOCK;
147 
148 #ifdef SOCK_CLOEXEC
149 	sock_flags |= SOCK_CLOEXEC;
150 #endif
151 
152 	fd = socket(AF_UNIX, sock_flags, 0);
153 	if (fd == -1) {
154 		log_warn("socket");
155 		return -1;
156 	}
157 
158 	sun.sun_family = AF_UNIX;
159 	if (strlcpy(sun.sun_path, unix_socket_path,
160 	    sizeof(sun.sun_path)) >= sizeof(sun.sun_path)) {
161 		log_warnx("%s: name too long", unix_socket_path);
162 		close(fd);
163 		return -1;
164 	}
165 
166 	if (unlink(unix_socket_path) == -1) {
167 		if (errno != ENOENT) {
168 			log_warn("unlink %s", unix_socket_path);
169 			close(fd);
170 			return -1;
171 		}
172 	}
173 
174 	old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);
175 	mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH;
176 
177 	if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
178 		log_warn("bind: %s", unix_socket_path);
179 		close(fd);
180 		umask(old_umask);
181 		return -1;
182 	}
183 
184 	umask(old_umask);
185 
186 	if (chmod(unix_socket_path, mode) == -1) {
187 		log_warn("chmod %o %s", mode, unix_socket_path);
188 		close(fd);
189 		unlink(unix_socket_path);
190 		return -1;
191 	}
192 
193 	if (chown(unix_socket_path, uid, gid) == -1) {
194 		log_warn("chown %s uid=%d gid=%d", unix_socket_path, uid, gid);
195 		close(fd);
196 		unlink(unix_socket_path);
197 		return -1;
198 	}
199 
200 	if (listen(fd, GOTD_UNIX_SOCKET_BACKLOG) == -1) {
201 		log_warn("listen");
202 		close(fd);
203 		unlink(unix_socket_path);
204 		return -1;
205 	}
206 
207 	return fd;
208 }
209 
210 static uint64_t
211 client_hash(uint32_t client_id)
212 {
213 	return SipHash24(&clients_hash_key, &client_id, sizeof(client_id));
214 }
215 
216 static void
217 add_client(struct gotd_client *client)
218 {
219 	uint64_t slot = client_hash(client->id) % nitems(gotd_clients);
220 	STAILQ_INSERT_HEAD(&gotd_clients[slot], client, entry);
221 	client_cnt++;
222 }
223 
224 static struct gotd_client *
225 find_client(uint32_t client_id)
226 {
227 	uint64_t slot;
228 	struct gotd_client *c;
229 
230 	slot = client_hash(client_id) % nitems(gotd_clients);
231 	STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
232 		if (c->id == client_id)
233 			return c;
234 	}
235 
236 	return NULL;
237 }
238 
239 static struct gotd_client *
240 find_client_by_proc_fd(int fd)
241 {
242 	uint64_t slot;
243 
244 	for (slot = 0; slot < nitems(gotd_clients); slot++) {
245 		struct gotd_client *c;
246 
247 		STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
248 			if (c->repo && c->repo->iev.ibuf.fd == fd)
249 				return c;
250 			if (c->auth && c->auth->iev.ibuf.fd == fd)
251 				return c;
252 			if (c->session && c->session->iev.ibuf.fd == fd)
253 				return c;
254 		}
255 	}
256 
257 	return NULL;
258 }
259 
260 static int
261 client_is_reading(struct gotd_client *client)
262 {
263 	return (client->required_auth &
264 	    (GOTD_AUTH_READ | GOTD_AUTH_WRITE)) == GOTD_AUTH_READ;
265 }
266 
267 static int
268 client_is_writing(struct gotd_client *client)
269 {
270 	return (client->required_auth &
271 	    (GOTD_AUTH_READ | GOTD_AUTH_WRITE)) ==
272 	    (GOTD_AUTH_READ | GOTD_AUTH_WRITE);
273 }
274 
275 static const struct got_error *
276 ensure_client_is_not_writing(struct gotd_client *client)
277 {
278 	if (client_is_writing(client)) {
279 		return got_error_fmt(GOT_ERR_BAD_PACKET,
280 		    "uid %d made a read-request but is writing to "
281 		    "a repository", client->euid);
282 	}
283 
284 	return NULL;
285 }
286 
287 static const struct got_error *
288 ensure_client_is_not_reading(struct gotd_client *client)
289 {
290 	if (client_is_reading(client)) {
291 		return got_error_fmt(GOT_ERR_BAD_PACKET,
292 		    "uid %d made a write-request but is reading from "
293 		    "a repository", client->euid);
294 	}
295 
296 	return NULL;
297 }
298 
299 static void
300 proc_done(struct gotd_child_proc *proc)
301 {
302 	struct gotd_client *client;
303 
304 	TAILQ_REMOVE(&procs, proc, entry);
305 
306 	client = find_client_by_proc_fd(proc->iev.ibuf.fd);
307 	if (client != NULL) {
308 		if (proc == client->repo)
309 			client->repo = NULL;
310 		if (proc == client->auth)
311 			client->auth = NULL;
312 		if (proc == client->session)
313 			client->session = NULL;
314 		disconnect(client);
315 	}
316 
317 	evtimer_del(&proc->tmo);
318 
319 	if (proc->iev.ibuf.fd != -1) {
320 		event_del(&proc->iev.ev);
321 		msgbuf_clear(&proc->iev.ibuf.w);
322 		close(proc->iev.ibuf.fd);
323 	}
324 
325 	free(proc);
326 }
327 
328 static void
329 kill_repo_proc(struct gotd_client *client)
330 {
331 	if (client->repo == NULL)
332 		return;
333 
334 	kill_proc(client->repo, 0);
335 	client->repo = NULL;
336 }
337 
338 static void
339 kill_auth_proc(struct gotd_client *client)
340 {
341 	if (client->auth == NULL)
342 		return;
343 
344 	kill_proc(client->auth, 0);
345 	client->auth = NULL;
346 }
347 
348 static void
349 kill_session_proc(struct gotd_client *client)
350 {
351 	if (client->session == NULL)
352 		return;
353 
354 	kill_proc(client->session, 0);
355 	client->session = NULL;
356 }
357 
358 static void
359 disconnect(struct gotd_client *client)
360 {
361 	struct gotd_imsg_disconnect idisconnect;
362 	struct gotd_child_proc *listen_proc = gotd.listen_proc;
363 	uint64_t slot;
364 
365 	log_debug("uid %d: disconnecting", client->euid);
366 
367 	kill_auth_proc(client);
368 	kill_session_proc(client);
369 	kill_repo_proc(client);
370 
371 	idisconnect.client_id = client->id;
372 	if (gotd_imsg_compose_event(&listen_proc->iev,
373 	    GOTD_IMSG_DISCONNECT, PROC_GOTD, -1,
374 	    &idisconnect, sizeof(idisconnect)) == -1)
375 		log_warn("imsg compose DISCONNECT");
376 
377 	slot = client_hash(client->id) % nitems(gotd_clients);
378 	STAILQ_REMOVE(&gotd_clients[slot], client, gotd_client, entry);
379 	imsg_clear(&client->iev.ibuf);
380 	event_del(&client->iev.ev);
381 	evtimer_del(&client->tmo);
382 	if (client->fd != -1)
383 		close(client->fd);
384 	else if (client->iev.ibuf.fd != -1)
385 		close(client->iev.ibuf.fd);
386 	free(client->username);
387 	free(client);
388 	client_cnt--;
389 }
390 
391 static void
392 disconnect_on_error(struct gotd_client *client, const struct got_error *err)
393 {
394 	struct imsgbuf ibuf;
395 
396 	if (err->code != GOT_ERR_EOF) {
397 		log_warnx("uid %d: %s", client->euid, err->msg);
398 		if (client->fd != -1) {
399 			imsg_init(&ibuf, client->fd);
400 			gotd_imsg_send_error(&ibuf, 0, PROC_GOTD, err);
401 			imsg_clear(&ibuf);
402 		}
403 	}
404 	disconnect(client);
405 }
406 
407 static const struct got_error *
408 send_repo_info(struct gotd_imsgev *iev, struct gotd_repo *repo)
409 {
410 	const struct got_error *err = NULL;
411 	struct gotd_imsg_info_repo irepo;
412 
413 	memset(&irepo, 0, sizeof(irepo));
414 
415 	if (strlcpy(irepo.repo_name, repo->name, sizeof(irepo.repo_name))
416 	    >= sizeof(irepo.repo_name))
417 		return got_error_msg(GOT_ERR_NO_SPACE, "repo name too long");
418 	if (strlcpy(irepo.repo_path, repo->path, sizeof(irepo.repo_path))
419 	    >= sizeof(irepo.repo_path))
420 		return got_error_msg(GOT_ERR_NO_SPACE, "repo path too long");
421 
422 	if (gotd_imsg_compose_event(iev, GOTD_IMSG_INFO_REPO, PROC_GOTD, -1,
423 	    &irepo, sizeof(irepo)) == -1) {
424 		err = got_error_from_errno("imsg compose INFO_REPO");
425 		if (err)
426 			return err;
427 	}
428 
429 	return NULL;
430 }
431 
432 static const struct got_error *
433 send_client_info(struct gotd_imsgev *iev, struct gotd_client *client)
434 {
435 	const struct got_error *err = NULL;
436 	struct gotd_imsg_info_client iclient;
437 	struct gotd_child_proc *proc;
438 
439 	memset(&iclient, 0, sizeof(iclient));
440 	iclient.euid = client->euid;
441 	iclient.egid = client->egid;
442 
443 	proc = client->repo;
444 	if (proc) {
445 		if (strlcpy(iclient.repo_name, proc->repo_path,
446 		    sizeof(iclient.repo_name)) >= sizeof(iclient.repo_name)) {
447 			return got_error_msg(GOT_ERR_NO_SPACE,
448 			    "repo name too long");
449 		}
450 		if (client_is_writing(client))
451 			iclient.is_writing = 1;
452 
453 		iclient.repo_child_pid = proc->pid;
454 	}
455 
456 	if (client->session)
457 		iclient.session_child_pid = client->session->pid;
458 
459 	if (gotd_imsg_compose_event(iev, GOTD_IMSG_INFO_CLIENT, PROC_GOTD, -1,
460 	    &iclient, sizeof(iclient)) == -1) {
461 		err = got_error_from_errno("imsg compose INFO_CLIENT");
462 		if (err)
463 			return err;
464 	}
465 
466 	return NULL;
467 }
468 
469 static const struct got_error *
470 send_info(struct gotd_client *client)
471 {
472 	const struct got_error *err = NULL;
473 	struct gotd_imsg_info info;
474 	uint64_t slot;
475 	struct gotd_repo *repo;
476 
477 	if (client->euid != 0)
478 		return got_error_set_errno(EPERM, "info");
479 
480 	info.pid = gotd.pid;
481 	info.verbosity = gotd.verbosity;
482 	info.nrepos = gotd.nrepos;
483 	info.nclients = client_cnt - 1;
484 
485 	if (gotd_imsg_compose_event(&client->iev, GOTD_IMSG_INFO, PROC_GOTD, -1,
486 	    &info, sizeof(info)) == -1) {
487 		err = got_error_from_errno("imsg compose INFO");
488 		if (err)
489 			return err;
490 	}
491 
492 	TAILQ_FOREACH(repo, &gotd.repos, entry) {
493 		err = send_repo_info(&client->iev, repo);
494 		if (err)
495 			return err;
496 	}
497 
498 	for (slot = 0; slot < nitems(gotd_clients); slot++) {
499 		struct gotd_client *c;
500 		STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
501 			if (c->id == client->id)
502 				continue;
503 			err = send_client_info(&client->iev, c);
504 			if (err)
505 				return err;
506 		}
507 	}
508 
509 	return NULL;
510 }
511 
512 static const struct got_error *
513 stop_gotd(struct gotd_client *client)
514 {
515 
516 	if (client->euid != 0)
517 		return got_error_set_errno(EPERM, "stop");
518 
519 	gotd_shutdown();
520 	/* NOTREACHED */
521 	return NULL;
522 }
523 
524 static const struct got_error *
525 start_client_authentication(struct gotd_client *client, struct imsg *imsg)
526 {
527 	const struct got_error *err;
528 	struct gotd_imsg_list_refs ireq;
529 	struct gotd_repo *repo = NULL;
530 	size_t datalen;
531 
532 	log_debug("list-refs request from uid %d", client->euid);
533 
534 	if (client->state != GOTD_CLIENT_STATE_NEW)
535 		return got_error_msg(GOT_ERR_BAD_REQUEST,
536 		    "unexpected list-refs request received");
537 
538 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
539 	if (datalen != sizeof(ireq))
540 		return got_error(GOT_ERR_PRIVSEP_LEN);
541 
542 	memcpy(&ireq, imsg->data, datalen);
543 
544 	if (ireq.client_is_reading) {
545 		err = ensure_client_is_not_writing(client);
546 		if (err)
547 			return err;
548 		repo = gotd_find_repo_by_name(ireq.repo_name, &gotd);
549 		if (repo == NULL)
550 			return got_error(GOT_ERR_NOT_GIT_REPO);
551 		err = start_auth_child(client, GOTD_AUTH_READ, repo,
552 		    gotd.argv0, gotd.confpath, gotd.daemonize,
553 		    gotd.verbosity);
554 		if (err)
555 			return err;
556 	} else {
557 		err = ensure_client_is_not_reading(client);
558 		if (err)
559 			return err;
560 		repo = gotd_find_repo_by_name(ireq.repo_name, &gotd);
561 		if (repo == NULL)
562 			return got_error(GOT_ERR_NOT_GIT_REPO);
563 		err = start_auth_child(client,
564 		    GOTD_AUTH_READ | GOTD_AUTH_WRITE,
565 		    repo, gotd.argv0, gotd.confpath, gotd.daemonize,
566 		    gotd.verbosity);
567 		if (err)
568 			return err;
569 	}
570 
571 	evtimer_add(&client->tmo, &auth_timeout);
572 
573 	/* Flow continues upon authentication success/failure or timeout. */
574 	return NULL;
575 }
576 
577 static void
578 gotd_request(int fd, short events, void *arg)
579 {
580 	struct gotd_imsgev *iev = arg;
581 	struct imsgbuf *ibuf = &iev->ibuf;
582 	struct gotd_client *client = iev->handler_arg;
583 	const struct got_error *err = NULL;
584 	struct imsg imsg;
585 	ssize_t n;
586 
587 	if (events & EV_WRITE) {
588 		while (ibuf->w.queued) {
589 			n = msgbuf_write(&ibuf->w);
590 			if (n == -1 && errno == EPIPE) {
591 				/*
592 				 * The client has closed its socket.
593 				 * This can happen when Git clients are
594 				 * done sending pack file data.
595 				 */
596 				msgbuf_clear(&ibuf->w);
597 				continue;
598 			} else if (n == -1 && errno != EAGAIN) {
599 				err = got_error_from_errno("imsg_flush");
600 				disconnect_on_error(client, err);
601 				return;
602 			}
603 			if (n == 0) {
604 				/* Connection closed. */
605 				err = got_error(GOT_ERR_EOF);
606 				disconnect_on_error(client, err);
607 				return;
608 			}
609 		}
610 
611 		/* Disconnect gotctl(8) now that messages have been sent. */
612 		if (!client_is_reading(client) && !client_is_writing(client)) {
613 			disconnect(client);
614 			return;
615 		}
616 	}
617 
618 	if ((events & EV_READ) == 0)
619 		return;
620 
621 	memset(&imsg, 0, sizeof(imsg));
622 
623 	while (err == NULL) {
624 		err = gotd_imsg_recv(&imsg, ibuf, 0);
625 		if (err) {
626 			if (err->code == GOT_ERR_PRIVSEP_READ)
627 				err = NULL;
628 			break;
629 		}
630 
631 		evtimer_del(&client->tmo);
632 
633 		switch (imsg.hdr.type) {
634 		case GOTD_IMSG_INFO:
635 			err = send_info(client);
636 			break;
637 		case GOTD_IMSG_STOP:
638 			err = stop_gotd(client);
639 			break;
640 		case GOTD_IMSG_LIST_REFS:
641 			err = start_client_authentication(client, &imsg);
642 			break;
643 		default:
644 			log_debug("unexpected imsg %d", imsg.hdr.type);
645 			err = got_error(GOT_ERR_PRIVSEP_MSG);
646 			break;
647 		}
648 
649 		imsg_free(&imsg);
650 	}
651 
652 	if (err) {
653 		disconnect_on_error(client, err);
654 	} else {
655 		gotd_imsg_event_add(&client->iev);
656 	}
657 }
658 
659 static void
660 gotd_auth_timeout(int fd, short events, void *arg)
661 {
662 	struct gotd_client *client = arg;
663 
664 	log_debug("disconnecting uid %d due to authentication timeout",
665 	    client->euid);
666 	disconnect(client);
667 }
668 
669 static const struct got_error *
670 recv_connect(uint32_t *client_id, struct imsg *imsg)
671 {
672 	const struct got_error *err = NULL;
673 	struct gotd_imsg_connect iconnect;
674 	size_t datalen;
675 	int s = -1;
676 	struct gotd_client *client = NULL;
677 
678 	*client_id = 0;
679 
680 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
681 	if (datalen != sizeof(iconnect))
682 		return got_error(GOT_ERR_PRIVSEP_LEN);
683 	memcpy(&iconnect, imsg->data, sizeof(iconnect));
684 
685 	s = imsg_get_fd(imsg);
686 	if (s == -1) {
687 		err = got_error(GOT_ERR_PRIVSEP_NO_FD);
688 		goto done;
689 	}
690 
691 	if (find_client(iconnect.client_id)) {
692 		err = got_error_msg(GOT_ERR_CLIENT_ID, "duplicate client ID");
693 		goto done;
694 	}
695 
696 	client = calloc(1, sizeof(*client));
697 	if (client == NULL) {
698 		err = got_error_from_errno("calloc");
699 		goto done;
700 	}
701 
702 	*client_id = iconnect.client_id;
703 
704 	client->state = GOTD_CLIENT_STATE_NEW;
705 	client->id = iconnect.client_id;
706 	client->fd = s;
707 	s = -1;
708 	/* The auth process will verify UID/GID for us. */
709 	client->euid = iconnect.euid;
710 	client->egid = iconnect.egid;
711 
712 	imsg_init(&client->iev.ibuf, client->fd);
713 	client->iev.handler = gotd_request;
714 	client->iev.events = EV_READ;
715 	client->iev.handler_arg = client;
716 
717 	event_set(&client->iev.ev, client->fd, EV_READ, gotd_request,
718 	    &client->iev);
719 	gotd_imsg_event_add(&client->iev);
720 
721 	evtimer_set(&client->tmo, gotd_auth_timeout, client);
722 
723 	add_client(client);
724 	log_debug("%s: new client uid %d connected on fd %d", __func__,
725 	    client->euid, client->fd);
726 done:
727 	if (err) {
728 		struct gotd_child_proc *listen_proc = gotd.listen_proc;
729 		struct gotd_imsg_disconnect idisconnect;
730 
731 		idisconnect.client_id = client->id;
732 		if (gotd_imsg_compose_event(&listen_proc->iev,
733 		    GOTD_IMSG_DISCONNECT, PROC_GOTD, -1,
734 		    &idisconnect, sizeof(idisconnect)) == -1)
735 			log_warn("imsg compose DISCONNECT");
736 
737 		if (s != -1)
738 			close(s);
739 	}
740 
741 	return err;
742 }
743 
744 static const char *gotd_proc_names[PROC_MAX] = {
745 	"parent",
746 	"listen",
747 	"auth",
748 	"session_read",
749 	"session_write",
750 	"repo_read",
751 	"repo_write",
752 	"gitwrapper"
753 };
754 
755 static void
756 kill_proc(struct gotd_child_proc *proc, int fatal)
757 {
758 	struct timeval tv = { 5, 0 };
759 
760 	log_debug("kill -%d %d", fatal ? SIGKILL : SIGTERM, proc->pid);
761 
762 	if (proc->iev.ibuf.fd != -1) {
763 		event_del(&proc->iev.ev);
764 		msgbuf_clear(&proc->iev.ibuf.w);
765 		close(proc->iev.ibuf.fd);
766 		proc->iev.ibuf.fd = -1;
767 	}
768 
769 	if (!evtimer_pending(&proc->tmo, NULL) && !fatal)
770 		evtimer_add(&proc->tmo, &tv);
771 
772 	if (fatal) {
773 		log_warnx("sending SIGKILL to PID %d", proc->pid);
774 		kill(proc->pid, SIGKILL);
775 	} else
776 		kill(proc->pid, SIGTERM);
777 }
778 
779 static void
780 kill_proc_timeout(int fd, short ev, void *d)
781 {
782 	struct gotd_child_proc *proc = d;
783 
784 	log_warnx("timeout waiting for PID %d to terminate;"
785 	    " retrying with force", proc->pid);
786 	kill_proc(proc, 1);
787 }
788 
789 static void
790 gotd_shutdown(void)
791 {
792 	uint64_t slot;
793 
794 	log_debug("shutting down");
795 	for (slot = 0; slot < nitems(gotd_clients); slot++) {
796 		struct gotd_client *c, *tmp;
797 
798 		STAILQ_FOREACH_SAFE(c, &gotd_clients[slot], entry, tmp)
799 			disconnect(c);
800 	}
801 
802 	kill_proc(gotd.listen_proc, 0);
803 
804 	log_info("terminating");
805 	exit(0);
806 }
807 
808 static struct gotd_child_proc *
809 find_proc_by_pid(pid_t pid)
810 {
811 	struct gotd_child_proc *proc = NULL;
812 
813 	TAILQ_FOREACH(proc, &procs, entry)
814 		if (proc->pid == pid)
815 			break;
816 
817 	return proc;
818 }
819 
820 void
821 gotd_sighdlr(int sig, short event, void *arg)
822 {
823 	struct gotd_child_proc *proc;
824 	pid_t pid;
825 	int status;
826 
827 	/*
828 	 * Normal signal handler rules don't apply because libevent
829 	 * decouples for us.
830 	 */
831 
832 	switch (sig) {
833 	case SIGHUP:
834 		log_info("%s: ignoring SIGHUP", __func__);
835 		break;
836 	case SIGUSR1:
837 		log_info("%s: ignoring SIGUSR1", __func__);
838 		break;
839 	case SIGTERM:
840 	case SIGINT:
841 		gotd_shutdown();
842 		break;
843 	case SIGCHLD:
844 		for (;;) {
845 			pid = waitpid(WAIT_ANY, &status, WNOHANG);
846 			if (pid == -1) {
847 				if (errno == EINTR)
848 					continue;
849 				if (errno == ECHILD)
850 					break;
851 				fatal("waitpid");
852 			}
853 			if (pid == 0)
854 				break;
855 
856 			log_debug("reaped pid %d", pid);
857 			proc = find_proc_by_pid(pid);
858 			if (proc == NULL) {
859 				log_info("caught exit of unknown child %d",
860 				    pid);
861 				continue;
862 			}
863 
864 			if (WIFSIGNALED(status)) {
865 				log_warnx("child PID %d terminated with"
866 				    " signal %d", pid, WTERMSIG(status));
867 			}
868 
869 			proc_done(proc);
870 		}
871 		break;
872 	default:
873 		fatalx("unexpected signal");
874 	}
875 }
876 
877 static const struct got_error *
878 ensure_proc_is_reading(struct gotd_client *client,
879     struct gotd_child_proc *proc)
880 {
881 	if (!client_is_reading(client)) {
882 		kill_proc(proc, 1);
883 		return got_error_fmt(GOT_ERR_BAD_PACKET,
884 		    "PID %d handled a read-request for uid %d but this "
885 		    "user is not reading from a repository", proc->pid,
886 		    client->euid);
887 	}
888 
889 	return NULL;
890 }
891 
892 static const struct got_error *
893 ensure_proc_is_writing(struct gotd_client *client,
894     struct gotd_child_proc *proc)
895 {
896 	if (!client_is_writing(client)) {
897 		kill_proc(proc, 1);
898 		return got_error_fmt(GOT_ERR_BAD_PACKET,
899 		    "PID %d handled a write-request for uid %d but this "
900 		    "user is not writing to a repository", proc->pid,
901 		    client->euid);
902 	}
903 
904 	return NULL;
905 }
906 
907 static int
908 verify_imsg_src(struct gotd_client *client, struct gotd_child_proc *proc,
909     struct imsg *imsg)
910 {
911 	const struct got_error *err;
912 	int ret = 0;
913 
914 	if (proc->type == PROC_REPO_READ || proc->type == PROC_REPO_WRITE) {
915 		if (client->repo == NULL)
916 			fatalx("no process found for uid %d", client->euid);
917 		if (proc->pid != client->repo->pid) {
918 			kill_proc(proc, 1);
919 			log_warnx("received message from PID %d for uid %d, "
920 			    "while PID %d is the process serving this user",
921 			    proc->pid, client->euid, client->repo->pid);
922 			return 0;
923 		}
924 	}
925 	if (proc->type == PROC_SESSION_READ ||
926 	    proc->type == PROC_SESSION_WRITE) {
927 		if (client->session == NULL) {
928 			log_warnx("no session found for uid %d", client->euid);
929 			return 0;
930 		}
931 		if (proc->pid != client->session->pid) {
932 			kill_proc(proc, 1);
933 			log_warnx("received message from PID %d for uid %d, "
934 			    "while PID %d is the process serving this user",
935 			    proc->pid, client->euid, client->session->pid);
936 			return 0;
937 		}
938 	}
939 
940 	switch (imsg->hdr.type) {
941 	case GOTD_IMSG_ERROR:
942 		ret = 1;
943 		break;
944 	case GOTD_IMSG_CONNECT:
945 		if (proc->type != PROC_LISTEN) {
946 			err = got_error_fmt(GOT_ERR_BAD_PACKET,
947 			    "new connection for uid %d from PID %d "
948 			    "which is not the listen process",
949 			    client->euid, proc->pid);
950 		} else
951 			ret = 1;
952 		break;
953 	case GOTD_IMSG_ACCESS_GRANTED:
954 		if (proc->type != PROC_AUTH) {
955 			err = got_error_fmt(GOT_ERR_BAD_PACKET,
956 			    "authentication of uid %d from PID %d "
957 			    "which is not the auth process",
958 			    client->euid, proc->pid);
959 		} else
960 			ret = 1;
961 		break;
962 	case GOTD_IMSG_CLIENT_SESSION_READY:
963 		if (proc->type != PROC_SESSION_READ &&
964 		    proc->type != PROC_SESSION_WRITE) {
965 			err = got_error_fmt(GOT_ERR_BAD_PACKET,
966 			    "unexpected \"ready\" signal from PID %d",
967 			    proc->pid);
968 		} else
969 			ret = 1;
970 		break;
971 	case GOTD_IMSG_REPO_CHILD_READY:
972 		if (proc->type != PROC_REPO_READ &&
973 		    proc->type != PROC_REPO_WRITE) {
974 			err = got_error_fmt(GOT_ERR_BAD_PACKET,
975 			    "unexpected \"ready\" signal from PID %d",
976 			    proc->pid);
977 		} else
978 			ret = 1;
979 		break;
980 	case GOTD_IMSG_PACKFILE_DONE:
981 		err = ensure_proc_is_reading(client, proc);
982 		if (err)
983 			log_warnx("uid %d: %s", client->euid, err->msg);
984 		else
985 			ret = 1;
986 		break;
987 	case GOTD_IMSG_PACKFILE_INSTALL:
988 	case GOTD_IMSG_REF_UPDATES_START:
989 	case GOTD_IMSG_REF_UPDATE:
990 		err = ensure_proc_is_writing(client, proc);
991 		if (err)
992 			log_warnx("uid %d: %s", client->euid, err->msg);
993 		else
994 			ret = 1;
995 		break;
996 	default:
997 		log_debug("%s: unexpected imsg %d", __func__, imsg->hdr.type);
998 		break;
999 	}
1000 
1001 	return ret;
1002 }
1003 
1004 static const struct got_error *
1005 connect_repo_child(struct gotd_client *client,
1006     struct gotd_child_proc *repo_proc)
1007 {
1008 	static const struct got_error *err;
1009 	struct gotd_imsgev *session_iev = &client->session->iev;
1010 	struct gotd_imsg_connect_repo_child ireq;
1011 	int pipe[2];
1012 	int sock_flags = SOCK_STREAM | SOCK_NONBLOCK;
1013 
1014 #ifdef SOCK_CLOEXEC
1015 	sock_flags |= SOCK_CLOEXEC;
1016 #endif
1017 
1018 	if (client->state != GOTD_CLIENT_STATE_ACCESS_GRANTED)
1019 		return got_error_msg(GOT_ERR_BAD_REQUEST,
1020 		    "unexpected repo child ready signal received");
1021 
1022 	if (socketpair(AF_UNIX, sock_flags, PF_UNSPEC, pipe) == -1)
1023 		fatal("socketpair");
1024 
1025 	memset(&ireq, 0, sizeof(ireq));
1026 	ireq.client_id = client->id;
1027 	ireq.proc_id = repo_proc->type;
1028 
1029 	/* Pass repo child pipe to session child process. */
1030 	if (gotd_imsg_compose_event(session_iev, GOTD_IMSG_CONNECT_REPO_CHILD,
1031 	    PROC_GOTD, pipe[0], &ireq, sizeof(ireq)) == -1) {
1032 		err = got_error_from_errno("imsg compose CONNECT_REPO_CHILD");
1033 		close(pipe[0]);
1034 		close(pipe[1]);
1035 		return err;
1036 	}
1037 
1038 	/* Pass session child pipe to repo child process. */
1039 	if (gotd_imsg_compose_event(&repo_proc->iev,
1040 	    GOTD_IMSG_CONNECT_REPO_CHILD, PROC_GOTD, pipe[1], NULL, 0) == -1) {
1041 		err = got_error_from_errno("imsg compose CONNECT_REPO_CHILD");
1042 		close(pipe[1]);
1043 		return err;
1044 	}
1045 
1046 	return NULL;
1047 }
1048 
1049 static void
1050 gotd_dispatch_listener(int fd, short event, void *arg)
1051 {
1052 	struct gotd_imsgev *iev = arg;
1053 	struct imsgbuf *ibuf = &iev->ibuf;
1054 	struct gotd_child_proc *proc = gotd.listen_proc;
1055 	ssize_t n;
1056 	int shut = 0;
1057 	struct imsg imsg;
1058 
1059 	if (proc->iev.ibuf.fd != fd)
1060 		fatalx("%s: unexpected fd %d", __func__, fd);
1061 
1062 	if (event & EV_READ) {
1063 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1064 			fatal("imsg_read error");
1065 		if (n == 0) {
1066 			/* Connection closed. */
1067 			shut = 1;
1068 			goto done;
1069 		}
1070 	}
1071 
1072 	if (event & EV_WRITE) {
1073 		n = msgbuf_write(&ibuf->w);
1074 		if (n == -1 && errno != EAGAIN)
1075 			fatal("msgbuf_write");
1076 		if (n == 0) {
1077 			/* Connection closed. */
1078 			shut = 1;
1079 			goto done;
1080 		}
1081 	}
1082 
1083 	for (;;) {
1084 		const struct got_error *err = NULL;
1085 		struct gotd_client *client = NULL;
1086 		uint32_t client_id = 0;
1087 		int do_disconnect = 0;
1088 
1089 		if ((n = imsg_get(ibuf, &imsg)) == -1)
1090 			fatal("%s: imsg_get error", __func__);
1091 		if (n == 0)	/* No more messages. */
1092 			break;
1093 
1094 		switch (imsg.hdr.type) {
1095 		case GOTD_IMSG_ERROR:
1096 			do_disconnect = 1;
1097 			err = gotd_imsg_recv_error(&client_id, &imsg);
1098 			break;
1099 		case GOTD_IMSG_CONNECT:
1100 			err = recv_connect(&client_id, &imsg);
1101 			break;
1102 		default:
1103 			log_debug("unexpected imsg %d", imsg.hdr.type);
1104 			break;
1105 		}
1106 
1107 		client = find_client(client_id);
1108 		if (client == NULL) {
1109 			log_warnx("%s: client not found", __func__);
1110 			imsg_free(&imsg);
1111 			continue;
1112 		}
1113 
1114 		if (err)
1115 			log_warnx("uid %d: %s", client->euid, err->msg);
1116 
1117 		if (do_disconnect) {
1118 			if (err)
1119 				disconnect_on_error(client, err);
1120 			else
1121 				disconnect(client);
1122 		}
1123 
1124 		imsg_free(&imsg);
1125 	}
1126 done:
1127 	if (!shut) {
1128 		gotd_imsg_event_add(iev);
1129 	} else {
1130 		/* This pipe is dead. Remove its event handler */
1131 		event_del(&iev->ev);
1132 		event_loopexit(NULL);
1133 	}
1134 }
1135 
1136 static void
1137 gotd_dispatch_auth_child(int fd, short event, void *arg)
1138 {
1139 	const struct got_error *err = NULL;
1140 	struct gotd_imsgev *iev = arg;
1141 	struct imsgbuf *ibuf = &iev->ibuf;
1142 	struct gotd_client *client;
1143 	struct gotd_repo *repo = NULL;
1144 	ssize_t n;
1145 	int shut = 0;
1146 	struct imsg imsg;
1147 	uint32_t client_id = 0;
1148 	int do_disconnect = 0;
1149 	size_t datalen;
1150 
1151 	client = find_client_by_proc_fd(fd);
1152 	if (client == NULL) {
1153 		/* Can happen during process teardown. */
1154 		warnx("cannot find client for fd %d", fd);
1155 		shut = 1;
1156 		goto done;
1157 	}
1158 
1159 	if (client->auth == NULL)
1160 		fatalx("cannot find auth child process for fd %d", fd);
1161 
1162 	if (event & EV_READ) {
1163 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1164 			fatal("imsg_read error");
1165 		if (n == 0) {
1166 			/* Connection closed. */
1167 			shut = 1;
1168 			goto done;
1169 		}
1170 	}
1171 
1172 	if (event & EV_WRITE) {
1173 		n = msgbuf_write(&ibuf->w);
1174 		if (n == -1 && errno != EAGAIN)
1175 			fatal("msgbuf_write");
1176 		if (n == 0) {
1177 			/* Connection closed. */
1178 			shut = 1;
1179 		}
1180 		goto done;
1181 	}
1182 
1183 	if (client->auth->iev.ibuf.fd != fd)
1184 		fatalx("%s: unexpected fd %d", __func__, fd);
1185 
1186 	if ((n = imsg_get(ibuf, &imsg)) == -1)
1187 		fatal("%s: imsg_get error", __func__);
1188 	if (n == 0)	/* No more messages. */
1189 		return;
1190 
1191 	evtimer_del(&client->tmo);
1192 
1193 	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
1194 
1195 	switch (imsg.hdr.type) {
1196 	case GOTD_IMSG_ERROR:
1197 		do_disconnect = 1;
1198 		err = gotd_imsg_recv_error(&client_id, &imsg);
1199 		break;
1200 	case GOTD_IMSG_ACCESS_GRANTED:
1201 		if (client->state != GOTD_CLIENT_STATE_NEW) {
1202 			do_disconnect = 1;
1203 			err = got_error(GOT_ERR_PRIVSEP_MSG);
1204 		}
1205 		break;
1206 	default:
1207 		do_disconnect = 1;
1208 		log_debug("unexpected imsg %d", imsg.hdr.type);
1209 		break;
1210 	}
1211 
1212 	if (!verify_imsg_src(client, client->auth, &imsg)) {
1213 		do_disconnect = 1;
1214 		log_debug("dropping imsg type %d from PID %d",
1215 		    imsg.hdr.type, client->auth->pid);
1216 	}
1217 
1218 	if (do_disconnect) {
1219 		if (err)
1220 			disconnect_on_error(client, err);
1221 		else
1222 			disconnect(client);
1223 		imsg_free(&imsg);
1224 		return;
1225 	}
1226 
1227 	client->state = GOTD_CLIENT_STATE_ACCESS_GRANTED;
1228 	if (datalen > 0)
1229 		client->username = strndup(imsg.data, datalen);
1230 	imsg_free(&imsg);
1231 	if (client->username == NULL &&
1232 	    asprintf(&client->username, "uid %d", client->euid) == -1) {
1233 		err = got_error_from_errno("asprintf");
1234 		goto done;
1235 	}
1236 
1237 	repo = gotd_find_repo_by_name(client->auth->repo_name, &gotd);
1238 	if (repo == NULL) {
1239 		err = got_error(GOT_ERR_NOT_GIT_REPO);
1240 		goto done;
1241 	}
1242 	kill_auth_proc(client);
1243 
1244 	log_info("authenticated %s for repository %s",
1245 	    client->username, repo->name);
1246 
1247 	err = start_session_child(client, repo, gotd.argv0,
1248 	    gotd.confpath, gotd.daemonize, gotd.verbosity);
1249 	if (err)
1250 		goto done;
1251 done:
1252 	if (err)
1253 		log_warnx("uid %d: %s", client->euid, err->msg);
1254 
1255 	/* We might have killed the auth process by now. */
1256 	if (client->auth != NULL) {
1257 		if (!shut) {
1258 			gotd_imsg_event_add(iev);
1259 		} else {
1260 			/* This pipe is dead. Remove its event handler */
1261 			event_del(&iev->ev);
1262 		}
1263 	}
1264 }
1265 
1266 static const struct got_error *
1267 connect_session(struct gotd_client *client)
1268 {
1269 	const struct got_error *err = NULL;
1270 	struct gotd_imsg_connect iconnect;
1271 	int s;
1272 
1273 	memset(&iconnect, 0, sizeof(iconnect));
1274 
1275 	s = dup(client->fd);
1276 	if (s == -1)
1277 		return got_error_from_errno("dup");
1278 
1279 	iconnect.client_id = client->id;
1280 	iconnect.euid = client->euid;
1281 	iconnect.egid = client->egid;
1282 
1283 	if (gotd_imsg_compose_event(&client->session->iev, GOTD_IMSG_CONNECT,
1284 	    PROC_GOTD, s, &iconnect, sizeof(iconnect)) == -1) {
1285 		err = got_error_from_errno("imsg compose CONNECT");
1286 		close(s);
1287 		return err;
1288 	}
1289 
1290 	/*
1291 	 * We are no longer interested in messages from this client.
1292 	 * Further client requests will be handled by the session process.
1293 	 */
1294 	msgbuf_clear(&client->iev.ibuf.w);
1295 	imsg_clear(&client->iev.ibuf);
1296 	event_del(&client->iev.ev);
1297 	client->fd = -1; /* will be closed via copy in client->iev.ibuf.fd */
1298 
1299 	return NULL;
1300 }
1301 
1302 static void
1303 gotd_dispatch_client_session(int fd, short event, void *arg)
1304 {
1305 	struct gotd_imsgev *iev = arg;
1306 	struct imsgbuf *ibuf = &iev->ibuf;
1307 	struct gotd_child_proc *proc = NULL;
1308 	struct gotd_client *client = NULL;
1309 	ssize_t n;
1310 	int shut = 0;
1311 	struct imsg imsg;
1312 
1313 	client = find_client_by_proc_fd(fd);
1314 	if (client == NULL) {
1315 		/* Can happen during process teardown. */
1316 		warnx("cannot find client for fd %d", fd);
1317 		shut = 1;
1318 		goto done;
1319 	}
1320 
1321 	if (event & EV_READ) {
1322 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1323 			fatal("imsg_read error");
1324 		if (n == 0) {
1325 			/* Connection closed. */
1326 			shut = 1;
1327 			goto done;
1328 		}
1329 	}
1330 
1331 	if (event & EV_WRITE) {
1332 		n = msgbuf_write(&ibuf->w);
1333 		if (n == -1 && errno != EAGAIN)
1334 			fatal("msgbuf_write");
1335 		if (n == 0) {
1336 			/* Connection closed. */
1337 			shut = 1;
1338 			goto done;
1339 		}
1340 	}
1341 
1342 	proc = client->session;
1343 	if (proc == NULL)
1344 		fatalx("cannot find session child process for fd %d", fd);
1345 
1346 	for (;;) {
1347 		const struct got_error *err = NULL;
1348 		uint32_t client_id = 0;
1349 		int do_disconnect = 0, do_start_repo_child = 0;
1350 
1351 		if ((n = imsg_get(ibuf, &imsg)) == -1)
1352 			fatal("%s: imsg_get error", __func__);
1353 		if (n == 0)	/* No more messages. */
1354 			break;
1355 
1356 		switch (imsg.hdr.type) {
1357 		case GOTD_IMSG_ERROR:
1358 			do_disconnect = 1;
1359 			err = gotd_imsg_recv_error(&client_id, &imsg);
1360 			break;
1361 		case GOTD_IMSG_CLIENT_SESSION_READY:
1362 			if (client->state != GOTD_CLIENT_STATE_ACCESS_GRANTED) {
1363 				err = got_error(GOT_ERR_PRIVSEP_MSG);
1364 				break;
1365 			}
1366 			do_start_repo_child = 1;
1367 			break;
1368 		case GOTD_IMSG_DISCONNECT:
1369 			do_disconnect = 1;
1370 			break;
1371 		default:
1372 			log_debug("unexpected imsg %d", imsg.hdr.type);
1373 			break;
1374 		}
1375 
1376 		if (!verify_imsg_src(client, proc, &imsg)) {
1377 			log_debug("dropping imsg type %d from PID %d",
1378 			    imsg.hdr.type, proc->pid);
1379 			imsg_free(&imsg);
1380 			continue;
1381 		}
1382 		if (err)
1383 			log_warnx("uid %d: %s", client->euid, err->msg);
1384 
1385 		if (do_start_repo_child) {
1386 			struct gotd_repo *repo;
1387 			const char *name = client->session->repo_name;
1388 
1389 			repo = gotd_find_repo_by_name(name, &gotd);
1390 			if (repo != NULL) {
1391 				enum gotd_procid proc_type;
1392 
1393 				if (client->required_auth & GOTD_AUTH_WRITE)
1394 					proc_type = PROC_REPO_WRITE;
1395 				else
1396 					proc_type = PROC_REPO_READ;
1397 
1398 				err = start_repo_child(client, proc_type, repo,
1399 				    gotd.argv0, gotd.confpath, gotd.daemonize,
1400 				    gotd.verbosity);
1401 			} else
1402 				err = got_error(GOT_ERR_NOT_GIT_REPO);
1403 
1404 			if (err) {
1405 				log_warnx("uid %d: %s", client->euid, err->msg);
1406 				do_disconnect = 1;
1407 			}
1408 		}
1409 
1410 		if (do_disconnect) {
1411 			if (err)
1412 				disconnect_on_error(client, err);
1413 			else
1414 				disconnect(client);
1415 		}
1416 
1417 		imsg_free(&imsg);
1418 	}
1419 done:
1420 	if (!shut) {
1421 		gotd_imsg_event_add(iev);
1422 	} else {
1423 		/* This pipe is dead. Remove its event handler */
1424 		event_del(&iev->ev);
1425 		disconnect(client);
1426 	}
1427 }
1428 
1429 static void
1430 gotd_dispatch_repo_child(int fd, short event, void *arg)
1431 {
1432 	struct gotd_imsgev *iev = arg;
1433 	struct imsgbuf *ibuf = &iev->ibuf;
1434 	struct gotd_child_proc *proc = NULL;
1435 	struct gotd_client *client;
1436 	ssize_t n;
1437 	int shut = 0;
1438 	struct imsg imsg;
1439 
1440 	client = find_client_by_proc_fd(fd);
1441 	if (client == NULL) {
1442 		/* Can happen during process teardown. */
1443 		warnx("cannot find client for fd %d", fd);
1444 		shut = 1;
1445 		goto done;
1446 	}
1447 
1448 	if (event & EV_READ) {
1449 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1450 			fatal("imsg_read error");
1451 		if (n == 0) {
1452 			/* Connection closed. */
1453 			shut = 1;
1454 			goto done;
1455 		}
1456 	}
1457 
1458 	if (event & EV_WRITE) {
1459 		n = msgbuf_write(&ibuf->w);
1460 		if (n == -1 && errno != EAGAIN)
1461 			fatal("msgbuf_write");
1462 		if (n == 0) {
1463 			/* Connection closed. */
1464 			shut = 1;
1465 			goto done;
1466 		}
1467 	}
1468 
1469 	proc = client->repo;
1470 	if (proc == NULL)
1471 		fatalx("cannot find child process for fd %d", fd);
1472 
1473 	for (;;) {
1474 		const struct got_error *err = NULL;
1475 		uint32_t client_id = 0;
1476 		int do_disconnect = 0;
1477 
1478 		if ((n = imsg_get(ibuf, &imsg)) == -1)
1479 			fatal("%s: imsg_get error", __func__);
1480 		if (n == 0)	/* No more messages. */
1481 			break;
1482 
1483 		switch (imsg.hdr.type) {
1484 		case GOTD_IMSG_ERROR:
1485 			do_disconnect = 1;
1486 			err = gotd_imsg_recv_error(&client_id, &imsg);
1487 			break;
1488 		case GOTD_IMSG_REPO_CHILD_READY:
1489 			err = connect_session(client);
1490 			if (err)
1491 				break;
1492 			err = connect_repo_child(client, proc);
1493 			break;
1494 		default:
1495 			log_debug("unexpected imsg %d", imsg.hdr.type);
1496 			break;
1497 		}
1498 
1499 		if (!verify_imsg_src(client, proc, &imsg)) {
1500 			log_debug("dropping imsg type %d from PID %d",
1501 			    imsg.hdr.type, proc->pid);
1502 			imsg_free(&imsg);
1503 			continue;
1504 		}
1505 		if (err)
1506 			log_warnx("uid %d: %s", client->euid, err->msg);
1507 
1508 		if (do_disconnect) {
1509 			if (err)
1510 				disconnect_on_error(client, err);
1511 			else
1512 				disconnect(client);
1513 		}
1514 
1515 		imsg_free(&imsg);
1516 	}
1517 done:
1518 	if (!shut) {
1519 		gotd_imsg_event_add(iev);
1520 	} else {
1521 		/* This pipe is dead. Remove its event handler */
1522 		event_del(&iev->ev);
1523 		disconnect(client);
1524 	}
1525 }
1526 
1527 static pid_t
1528 start_child(enum gotd_procid proc_id, const char *repo_path,
1529     char *argv0, const char *confpath, int fd, int daemonize, int verbosity)
1530 {
1531 	char	*argv[11];
1532 	int	 argc = 0;
1533 	pid_t	 pid;
1534 
1535 	switch (pid = fork()) {
1536 	case -1:
1537 		fatal("cannot fork");
1538 	case 0:
1539 		break;
1540 	default:
1541 		close(fd);
1542 		return pid;
1543 	}
1544 
1545 	if (fd != GOTD_FILENO_MSG_PIPE) {
1546 		if (dup2(fd, GOTD_FILENO_MSG_PIPE) == -1)
1547 			fatal("cannot setup imsg fd");
1548 	} else if (fcntl(fd, F_SETFD, 0) == -1)
1549 		fatal("cannot setup imsg fd");
1550 
1551 	argv[argc++] = argv0;
1552 	switch (proc_id) {
1553 	case PROC_LISTEN:
1554 		argv[argc++] = (char *)"-L";
1555 		break;
1556 	case PROC_AUTH:
1557 		argv[argc++] = (char *)"-A";
1558 		break;
1559 	case PROC_SESSION_READ:
1560 		argv[argc++] = (char *)"-s";
1561 		break;
1562 	case PROC_SESSION_WRITE:
1563 		argv[argc++] = (char *)"-S";
1564 		break;
1565 	case PROC_REPO_READ:
1566 		argv[argc++] = (char *)"-R";
1567 		break;
1568 	case PROC_REPO_WRITE:
1569 		argv[argc++] = (char *)"-W";
1570 		break;
1571 	default:
1572 		fatalx("invalid process id %d", proc_id);
1573 	}
1574 
1575 	argv[argc++] = (char *)"-f";
1576 	argv[argc++] = (char *)confpath;
1577 
1578 	if (repo_path) {
1579 		argv[argc++] = (char *)"-P";
1580 		argv[argc++] = (char *)repo_path;
1581 	}
1582 
1583 	if (!daemonize)
1584 		argv[argc++] = (char *)"-d";
1585 	if (verbosity > 0)
1586 		argv[argc++] = (char *)"-v";
1587 	if (verbosity > 1)
1588 		argv[argc++] = (char *)"-v";
1589 	argv[argc++] = NULL;
1590 
1591 	execvp(argv0, argv);
1592 	fatal("execvp");
1593 }
1594 
1595 static void
1596 start_listener(char *argv0, const char *confpath, int daemonize, int verbosity)
1597 {
1598 	struct gotd_child_proc *proc;
1599 	int sock_flags = SOCK_STREAM|SOCK_NONBLOCK;
1600 
1601 #ifdef SOCK_CLOEXEC
1602 	sock_flags |= SOCK_CLOEXEC;
1603 #endif
1604 
1605 	proc = calloc(1, sizeof(*proc));
1606 	if (proc == NULL)
1607 		fatal("calloc");
1608 
1609 	TAILQ_INSERT_HEAD(&procs, proc, entry);
1610 
1611 	/* proc->tmo is initialized in main() after event_init() */
1612 
1613 	proc->type = PROC_LISTEN;
1614 
1615 	if (socketpair(AF_UNIX, sock_flags,
1616 	    PF_UNSPEC, proc->pipe) == -1)
1617 		fatal("socketpair");
1618 
1619 	proc->pid = start_child(proc->type, NULL, argv0, confpath,
1620 	    proc->pipe[1], daemonize, verbosity);
1621 	imsg_init(&proc->iev.ibuf, proc->pipe[0]);
1622 	proc->iev.handler = gotd_dispatch_listener;
1623 	proc->iev.events = EV_READ;
1624 	proc->iev.handler_arg = NULL;
1625 
1626 	gotd.listen_proc = proc;
1627 }
1628 
1629 static const struct got_error *
1630 start_session_child(struct gotd_client *client, struct gotd_repo *repo,
1631     char *argv0, const char *confpath, int daemonize, int verbosity)
1632 {
1633 	struct gotd_child_proc *proc;
1634 	int sock_flags = SOCK_STREAM | SOCK_NONBLOCK;
1635 
1636 #ifdef SOCK_CLOEXEC
1637 	sock_flags |= SOCK_CLOEXEC;
1638 #endif
1639 
1640 	proc = calloc(1, sizeof(*proc));
1641 	if (proc == NULL)
1642 		return got_error_from_errno("calloc");
1643 
1644 	TAILQ_INSERT_HEAD(&procs, proc, entry);
1645 	evtimer_set(&proc->tmo, kill_proc_timeout, proc);
1646 
1647 	if (client_is_reading(client))
1648 		proc->type = PROC_SESSION_READ;
1649 	else
1650 		proc->type = PROC_SESSION_WRITE;
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 client uid %d session for repository %s",
1655 	    client->euid, 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_flags, PF_UNSPEC, proc->pipe) == -1)
1660 		fatal("socketpair");
1661 	proc->pid = start_child(proc->type, proc->repo_path, argv0,
1662 	    confpath, proc->pipe[1], daemonize, verbosity);
1663 	imsg_init(&proc->iev.ibuf, proc->pipe[0]);
1664 	log_debug("proc %s %s is on fd %d",
1665 	    gotd_proc_names[proc->type], proc->repo_path,
1666 	    proc->pipe[0]);
1667 	proc->iev.handler = gotd_dispatch_client_session;
1668 	proc->iev.events = EV_READ;
1669 	proc->iev.handler_arg = NULL;
1670 	event_set(&proc->iev.ev, proc->iev.ibuf.fd, EV_READ,
1671 	    gotd_dispatch_client_session, &proc->iev);
1672 	gotd_imsg_event_add(&proc->iev);
1673 
1674 	client->session = proc;
1675 	return NULL;
1676 }
1677 
1678 static const struct got_error *
1679 start_repo_child(struct gotd_client *client, enum gotd_procid proc_type,
1680     struct gotd_repo *repo, char *argv0, const char *confpath,
1681     int daemonize, int verbosity)
1682 {
1683 	struct gotd_child_proc *proc;
1684 	int sock_flags = SOCK_STREAM|SOCK_NONBLOCK;
1685 
1686 #ifdef SOCK_CLOEXEC
1687 	sock_flags |= SOCK_CLOEXEC;
1688 #endif
1689 
1690 	if (proc_type != PROC_REPO_READ && proc_type != PROC_REPO_WRITE)
1691 		return got_error_msg(GOT_ERR_NOT_IMPL, "bad process type");
1692 
1693 	proc = calloc(1, sizeof(*proc));
1694 	if (proc == NULL)
1695 		return got_error_from_errno("calloc");
1696 
1697 	TAILQ_INSERT_HEAD(&procs, proc, entry);
1698 	evtimer_set(&proc->tmo, kill_proc_timeout, proc);
1699 
1700 	proc->type = proc_type;
1701 	if (strlcpy(proc->repo_name, repo->name,
1702 	    sizeof(proc->repo_name)) >= sizeof(proc->repo_name))
1703 		fatalx("repository name too long: %s", repo->name);
1704 	log_debug("starting %s for repository %s",
1705 	    proc->type == PROC_REPO_READ ? "reader" : "writer", repo->name);
1706 
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 (realpath(repo->path, proc->repo_path) == NULL)
1711 		fatal("%s", repo->path);
1712 	if (socketpair(AF_UNIX, sock_flags,
1713 	    PF_UNSPEC, proc->pipe) == -1)
1714 		fatal("socketpair");
1715 	proc->pid = start_child(proc->type, proc->repo_path, argv0,
1716 	    confpath, proc->pipe[1], daemonize, verbosity);
1717 	imsg_init(&proc->iev.ibuf, proc->pipe[0]);
1718 	log_debug("proc %s %s is on fd %d",
1719 	    gotd_proc_names[proc->type], proc->repo_path,
1720 	    proc->pipe[0]);
1721 	proc->iev.handler = gotd_dispatch_repo_child;
1722 	proc->iev.events = EV_READ;
1723 	proc->iev.handler_arg = NULL;
1724 	event_set(&proc->iev.ev, proc->iev.ibuf.fd, EV_READ,
1725 	    gotd_dispatch_repo_child, &proc->iev);
1726 	gotd_imsg_event_add(&proc->iev);
1727 
1728 	client->repo = proc;
1729 	return NULL;
1730 }
1731 
1732 static const struct got_error *
1733 start_auth_child(struct gotd_client *client, int required_auth,
1734     struct gotd_repo *repo, char *argv0, const char *confpath,
1735     int daemonize, int verbosity)
1736 {
1737 	const struct got_error *err = NULL;
1738 	struct gotd_child_proc *proc;
1739 	struct gotd_imsg_auth iauth;
1740 	int fd;
1741 	int sock_flags = SOCK_STREAM|SOCK_NONBLOCK;
1742 
1743 #ifdef SOCK_CLOEXEC
1744 	sock_flags |= SOCK_CLOEXEC;
1745 #endif
1746 
1747 	memset(&iauth, 0, sizeof(iauth));
1748 
1749 	fd = dup(client->fd);
1750 	if (fd == -1)
1751 		return got_error_from_errno("dup");
1752 
1753 	proc = calloc(1, sizeof(*proc));
1754 	if (proc == NULL) {
1755 		err = got_error_from_errno("calloc");
1756 		close(fd);
1757 		return err;
1758 	}
1759 
1760 	TAILQ_INSERT_HEAD(&procs, proc, entry);
1761 	evtimer_set(&proc->tmo, kill_proc_timeout, proc);
1762 
1763 	proc->type = PROC_AUTH;
1764 	if (strlcpy(proc->repo_name, repo->name,
1765 	    sizeof(proc->repo_name)) >= sizeof(proc->repo_name))
1766 		fatalx("repository name too long: %s", repo->name);
1767 	log_debug("starting auth for uid %d repository %s",
1768 	    client->euid, repo->name);
1769 	if (strlcpy(proc->repo_path, repo->path, sizeof(proc->repo_path)) >=
1770 	    sizeof(proc->repo_path))
1771 		fatalx("repository path too long: %s", repo->path);
1772 	if (realpath(repo->path, proc->repo_path) == NULL)
1773 		fatal("%s", repo->path);
1774 	if (socketpair(AF_UNIX, sock_flags,
1775 	    PF_UNSPEC, proc->pipe) == -1)
1776 		fatal("socketpair");
1777 	proc->pid = start_child(proc->type, proc->repo_path, argv0,
1778 	    confpath, proc->pipe[1], daemonize, verbosity);
1779 	imsg_init(&proc->iev.ibuf, proc->pipe[0]);
1780 	log_debug("proc %s %s is on fd %d",
1781 	    gotd_proc_names[proc->type], proc->repo_path,
1782 	    proc->pipe[0]);
1783 	proc->iev.handler = gotd_dispatch_auth_child;
1784 	proc->iev.events = EV_READ;
1785 	proc->iev.handler_arg = NULL;
1786 	event_set(&proc->iev.ev, proc->iev.ibuf.fd, EV_READ,
1787 	    gotd_dispatch_auth_child, &proc->iev);
1788 	gotd_imsg_event_add(&proc->iev);
1789 
1790 	iauth.euid = client->euid;
1791 	iauth.egid = client->egid;
1792 	iauth.required_auth = required_auth;
1793 	iauth.client_id = client->id;
1794 	if (gotd_imsg_compose_event(&proc->iev, GOTD_IMSG_AUTHENTICATE,
1795 	    PROC_GOTD, fd, &iauth, sizeof(iauth)) == -1) {
1796 		log_warn("imsg compose AUTHENTICATE");
1797 		close(fd);
1798 		/* Let the auth_timeout handler tidy up. */
1799 	}
1800 
1801 	client->auth = proc;
1802 	client->required_auth = required_auth;
1803 	return NULL;
1804 }
1805 
1806 static void
1807 apply_unveil_repo_readonly(const char *repo_path, int need_tmpdir)
1808 {
1809 	if (need_tmpdir) {
1810 		if (unveil(GOT_TMPDIR_STR, "rwc") == -1)
1811 			fatal("unveil %s", GOT_TMPDIR_STR);
1812 	}
1813 
1814 	if (unveil(repo_path, "r") == -1)
1815 		fatal("unveil %s", repo_path);
1816 
1817 	if (unveil(NULL, NULL) == -1)
1818 		fatal("unveil");
1819 }
1820 
1821 static void
1822 apply_unveil_repo_readwrite(const char *repo_path)
1823 {
1824 	if (unveil(repo_path, "rwc") == -1)
1825 		fatal("unveil %s", repo_path);
1826 
1827 	if (unveil(GOT_TMPDIR_STR, "rwc") == -1)
1828 		fatal("unveil %s", GOT_TMPDIR_STR);
1829 
1830 	if (unveil(NULL, NULL) == -1)
1831 		fatal("unveil");
1832 }
1833 
1834 static void
1835 apply_unveil_none(void)
1836 {
1837 	if (unveil("/", "") == -1)
1838 		fatal("unveil");
1839 
1840 	if (unveil(NULL, NULL) == -1)
1841 		fatal("unveil");
1842 }
1843 
1844 static void
1845 apply_unveil_selfexec(void)
1846 {
1847 	if (unveil(gotd.argv0, "x") == -1)
1848 		fatal("unveil %s", gotd.argv0);
1849 
1850 	if (unveil(NULL, NULL) == -1)
1851 		fatal("unveil");
1852 }
1853 
1854 static void
1855 set_max_datasize(void)
1856 {
1857 	struct rlimit rl;
1858 
1859 	if (getrlimit(RLIMIT_DATA, &rl) != 0)
1860 		return;
1861 
1862 	rl.rlim_cur = rl.rlim_max;
1863 	setrlimit(RLIMIT_DATA, &rl);
1864 }
1865 
1866 int
1867 main(int argc, char **argv)
1868 {
1869 	const struct got_error *error = NULL;
1870 	int ch, fd = -1, daemonize = 1, verbosity = 0, noaction = 0;
1871 	const char *confpath = GOTD_CONF_PATH;
1872 	char *argv0 = argv[0];
1873 	char title[2048];
1874 	struct passwd *pw = NULL;
1875 	char *repo_path = NULL;
1876 	enum gotd_procid proc_id = PROC_GOTD;
1877 	struct event evsigint, evsigterm, evsighup, evsigusr1, evsigchld;
1878 	int *pack_fds = NULL, *temp_fds = NULL;
1879 	struct gotd_repo *repo = NULL;
1880 
1881 	TAILQ_INIT(&procs);
1882 
1883 	log_init(1, LOG_DAEMON); /* Log to stderr until daemonized. */
1884 
1885 	while ((ch = getopt(argc, argv, "Adf:LnP:RsSvW")) != -1) {
1886 		switch (ch) {
1887 		case 'A':
1888 			proc_id = PROC_AUTH;
1889 			break;
1890 		case 'd':
1891 			daemonize = 0;
1892 			break;
1893 		case 'f':
1894 			confpath = optarg;
1895 			break;
1896 		case 'L':
1897 			proc_id = PROC_LISTEN;
1898 			break;
1899 		case 'n':
1900 			noaction = 1;
1901 			break;
1902 		case 'P':
1903 			repo_path = realpath(optarg, NULL);
1904 			if (repo_path == NULL)
1905 				fatal("realpath '%s'", optarg);
1906 			break;
1907 		case 'R':
1908 			proc_id = PROC_REPO_READ;
1909 			break;
1910 		case 's':
1911 			proc_id = PROC_SESSION_READ;
1912 			break;
1913 		case 'S':
1914 			proc_id = PROC_SESSION_WRITE;
1915 			break;
1916 		case 'v':
1917 			if (verbosity < 3)
1918 				verbosity++;
1919 			break;
1920 		case 'W':
1921 			proc_id = PROC_REPO_WRITE;
1922 			break;
1923 		default:
1924 			usage();
1925 		}
1926 	}
1927 
1928 	argc -= optind;
1929 	argv += optind;
1930 
1931 	if (argc != 0)
1932 		usage();
1933 
1934 	if (geteuid() && (proc_id == PROC_GOTD || proc_id == PROC_LISTEN))
1935 		fatalx("need root privileges");
1936 
1937 	if (parse_config(confpath, proc_id, &gotd) != 0)
1938 		return 1;
1939 
1940 	pw = getpwnam(gotd.user_name);
1941 	if (pw == NULL)
1942 		fatalx("user %s not found", gotd.user_name);
1943 
1944 	if (pw->pw_uid == 0)
1945 		fatalx("cannot run %s as the superuser", getprogname());
1946 
1947 	if (noaction) {
1948 		fprintf(stderr, "configuration OK\n");
1949 		return 0;
1950 	}
1951 
1952 	gotd.argv0 = argv0;
1953 	gotd.daemonize = daemonize;
1954 	gotd.verbosity = verbosity;
1955 	gotd.confpath = confpath;
1956 
1957 	/* Require an absolute path in argv[0] for reliable re-exec. */
1958 	if (!got_path_is_absolute(argv0))
1959 		fatalx("bad path \"%s\": must be an absolute path", argv0);
1960 
1961 	log_init(daemonize ? 0 : 1, LOG_DAEMON);
1962 	log_setverbose(verbosity);
1963 
1964 	if (proc_id == PROC_GOTD) {
1965 		snprintf(title, sizeof(title), "%s", gotd_proc_names[proc_id]);
1966 		arc4random_buf(&clients_hash_key, sizeof(clients_hash_key));
1967 		if (daemonize && daemon(1, 0) == -1)
1968 			fatal("daemon");
1969 		gotd.pid = getpid();
1970 		start_listener(argv0, confpath, daemonize, verbosity);
1971 	} else if (proc_id == PROC_LISTEN) {
1972 		snprintf(title, sizeof(title), "%s", gotd_proc_names[proc_id]);
1973 		if (verbosity) {
1974 			log_info("socket: %s", gotd.unix_socket_path);
1975 			log_info("user: %s", pw->pw_name);
1976 		}
1977 
1978 		fd = unix_socket_listen(gotd.unix_socket_path, pw->pw_uid,
1979 		    pw->pw_gid);
1980 		if (fd == -1) {
1981 			fatal("cannot listen on unix socket %s",
1982 			    gotd.unix_socket_path);
1983 		}
1984 	} else if (proc_id == PROC_AUTH) {
1985 		snprintf(title, sizeof(title), "%s %s",
1986 		    gotd_proc_names[proc_id], repo_path);
1987 	} else if (proc_id == PROC_REPO_READ || proc_id == PROC_REPO_WRITE ||
1988 	    proc_id == PROC_SESSION_READ || proc_id == PROC_SESSION_WRITE) {
1989 		error = got_repo_pack_fds_open(&pack_fds);
1990 		if (error != NULL)
1991 			fatalx("cannot open pack tempfiles: %s", error->msg);
1992 		error = got_repo_temp_fds_open(&temp_fds);
1993 		if (error != NULL)
1994 			fatalx("cannot open pack tempfiles: %s", error->msg);
1995 		if (repo_path == NULL)
1996 			fatalx("repository path not specified");
1997 		snprintf(title, sizeof(title), "%s %s",
1998 		    gotd_proc_names[proc_id], repo_path);
1999 	} else
2000 		fatal("invalid process id %d", proc_id);
2001 
2002 	setproctitle("%s", title);
2003 	log_procinit(title);
2004 
2005 	if (proc_id != PROC_GOTD && proc_id != PROC_LISTEN &&
2006 	    proc_id != PROC_REPO_READ && proc_id != PROC_REPO_WRITE) {
2007 		/* Drop root privileges. */
2008 		if (setgid(pw->pw_gid) == -1)
2009 			fatal("setgid %d failed", pw->pw_gid);
2010 		if (setuid(pw->pw_uid) == -1)
2011 			fatal("setuid %d failed", pw->pw_uid);
2012 	}
2013 
2014 	event_init();
2015 
2016 	switch (proc_id) {
2017 	case PROC_GOTD:
2018 #ifndef PROFILE
2019 		/* "exec" promise will be limited to argv[0] via unveil(2). */
2020 		if (pledge("stdio proc exec sendfd recvfd unveil", NULL) == -1)
2021 			err(1, "pledge");
2022 #endif
2023 		break;
2024 	case PROC_LISTEN:
2025 #ifndef PROFILE
2026 		if (pledge("stdio sendfd unix unveil", NULL) == -1)
2027 			err(1, "pledge");
2028 #endif
2029 		/*
2030 		 * Ensure that AF_UNIX bind(2) cannot be used with any other
2031 		 * sockets by revoking all filesystem access via unveil(2).
2032 		 */
2033 		apply_unveil_none();
2034 
2035 		enter_chroot(GOTD_EMPTY_PATH);
2036 		drop_privs(pw);
2037 
2038 		listen_main(title, fd, gotd.connection_limits,
2039 		    gotd.nconnection_limits);
2040 		/* NOTREACHED */
2041 		break;
2042 	case PROC_AUTH:
2043 #ifndef PROFILE
2044 		if (pledge("stdio getpw recvfd unix unveil", NULL) == -1)
2045 			err(1, "pledge");
2046 #endif
2047 		/*
2048 		 * We need the "unix" pledge promise for getpeername(2) only.
2049 		 * Ensure that AF_UNIX bind(2) cannot be used by revoking all
2050 		 * filesystem access via unveil(2). Access to password database
2051 		 * files will still work since "getpw" bypasses unveil(2).
2052 		 */
2053 		apply_unveil_none();
2054 
2055 		auth_main(title, &gotd.repos, repo_path);
2056 		/* NOTREACHED */
2057 		break;
2058 	case PROC_SESSION_READ:
2059 	case PROC_SESSION_WRITE:
2060 #ifndef PROFILE
2061 		/*
2062 		 * The "recvfd" promise is only needed during setup and
2063 		 * will be removed in a later pledge(2) call.
2064 		 */
2065 		if (pledge("stdio rpath wpath cpath recvfd sendfd fattr flock "
2066 		    "unveil", NULL) == -1)
2067 			err(1, "pledge");
2068 #endif
2069 		if (proc_id == PROC_SESSION_READ)
2070 			apply_unveil_repo_readonly(repo_path, 1);
2071 		else
2072 			apply_unveil_repo_readwrite(repo_path);
2073 
2074 		session_main(title, repo_path, pack_fds, temp_fds,
2075 		    &gotd.request_timeout, proc_id);
2076 		/* NOTREACHED */
2077 		break;
2078 	case PROC_REPO_READ:
2079 		set_max_datasize();
2080 #ifndef PROFILE
2081 		if (pledge("stdio rpath recvfd unveil", NULL) == -1)
2082 			err(1, "pledge");
2083 #endif
2084 		apply_unveil_repo_readonly(repo_path, 0);
2085 
2086 		if (enter_chroot(repo_path)) {
2087 			log_info("change repo path %s", repo_path);
2088 			free(repo_path);
2089 			repo_path = strdup("/");
2090 			if (repo_path == NULL)
2091 				fatal("strdup");
2092 			log_info("repo path is now %s", repo_path);
2093 		}
2094 		drop_privs(pw);
2095 
2096 		repo_read_main(title, repo_path, pack_fds, temp_fds);
2097 		/* NOTREACHED */
2098 		exit(0);
2099 	case PROC_REPO_WRITE:
2100 		set_max_datasize();
2101 #ifndef PROFILE
2102 		if (pledge("stdio rpath recvfd unveil", NULL) == -1)
2103 			err(1, "pledge");
2104 #endif
2105 		apply_unveil_repo_readonly(repo_path, 0);
2106 		repo = gotd_find_repo_by_path(repo_path, &gotd);
2107 		if (repo == NULL)
2108 			fatalx("no repository for path %s", repo_path);
2109 
2110 		if (enter_chroot(repo_path)) {
2111 			free(repo_path);
2112 			repo_path = strdup("/");
2113 			if (repo_path == NULL)
2114 				fatal("strdup");
2115 		}
2116 		drop_privs(pw);
2117 
2118 		repo_write_main(title, repo_path, pack_fds, temp_fds,
2119 		    &repo->protected_tag_namespaces,
2120 		    &repo->protected_branch_namespaces,
2121 		    &repo->protected_branches);
2122 		/* NOTREACHED */
2123 		exit(0);
2124 	default:
2125 		fatal("invalid process id %d", proc_id);
2126 	}
2127 
2128 	if (proc_id != PROC_GOTD)
2129 		fatal("invalid process id %d", proc_id);
2130 
2131 	evtimer_set(&gotd.listen_proc->tmo, kill_proc_timeout,
2132 	    gotd.listen_proc);
2133 
2134 	apply_unveil_selfexec();
2135 
2136 	signal_set(&evsigint, SIGINT, gotd_sighdlr, NULL);
2137 	signal_set(&evsigterm, SIGTERM, gotd_sighdlr, NULL);
2138 	signal_set(&evsighup, SIGHUP, gotd_sighdlr, NULL);
2139 	signal_set(&evsigusr1, SIGUSR1, gotd_sighdlr, NULL);
2140 	signal_set(&evsigchld, SIGCHLD, gotd_sighdlr, NULL);
2141 	signal(SIGPIPE, SIG_IGN);
2142 
2143 	signal_add(&evsigint, NULL);
2144 	signal_add(&evsigterm, NULL);
2145 	signal_add(&evsighup, NULL);
2146 	signal_add(&evsigusr1, NULL);
2147 	signal_add(&evsigchld, NULL);
2148 
2149 	gotd_imsg_event_add(&gotd.listen_proc->iev);
2150 
2151 	event_dispatch();
2152 
2153 	free(repo_path);
2154 	gotd_shutdown();
2155 
2156 	return 0;
2157 }