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 	struct gotd_child_proc		*repo;
98 	struct gotd_child_proc		*auth;
99 	struct gotd_child_proc		*session;
100 	int				 required_auth;
101 };
102 STAILQ_HEAD(gotd_clients, gotd_client);
103 
104 static struct gotd_clients gotd_clients[GOTD_CLIENT_TABLE_SIZE];
105 static SIPHASH_KEY clients_hash_key;
106 volatile int client_cnt;
107 static struct timeval auth_timeout = { 5, 0 };
108 static struct gotd gotd;
109 
110 void gotd_sighdlr(int sig, short event, void *arg);
111 static void gotd_shutdown(void);
112 static const struct got_error *start_session_child(struct gotd_client *,
113     struct gotd_repo *, char *, const char *, int, int);
114 static const struct got_error *start_repo_child(struct gotd_client *,
115     enum gotd_procid, struct gotd_repo *, char *, const char *, int, int);
116 static const struct got_error *start_auth_child(struct gotd_client *, int,
117     struct gotd_repo *, char *, const char *, int, int);
118 static void kill_proc(struct gotd_child_proc *, int);
119 static void disconnect(struct gotd_client *);
120 static void drop_privs(struct passwd *);
121 
122 __dead static void
123 usage(void)
124 {
125 	fprintf(stderr, "usage: %s [-dnv] [-f config-file]\n", getprogname());
126 	exit(1);
127 }
128 
129 static void
130 drop_privs(struct passwd *pw)
131 {
132 	/* Drop root privileges. */
133 	if (setgid(pw->pw_gid) == -1)
134 		fatal("setgid %d failed", pw->pw_gid);
135 	if (setuid(pw->pw_uid) == -1)
136 		fatal("setuid %d failed", pw->pw_uid);
137 }
138 
139 static int
140 unix_socket_listen(const char *unix_socket_path, uid_t uid, gid_t gid)
141 {
142 	struct sockaddr_un sun;
143 	int fd = -1;
144 	mode_t old_umask, mode;
145 	int sock_flags = SOCK_STREAM | SOCK_NONBLOCK;
146 
147 #ifdef SOCK_CLOEXEC
148 	sock_flags |= SOCK_CLOEXEC;
149 #endif
150 
151 	fd = socket(AF_UNIX, sock_flags, 0);
152 	if (fd == -1) {
153 		log_warn("socket");
154 		return -1;
155 	}
156 
157 	sun.sun_family = AF_UNIX;
158 	if (strlcpy(sun.sun_path, unix_socket_path,
159 	    sizeof(sun.sun_path)) >= sizeof(sun.sun_path)) {
160 		log_warnx("%s: name too long", unix_socket_path);
161 		close(fd);
162 		return -1;
163 	}
164 
165 	if (unlink(unix_socket_path) == -1) {
166 		if (errno != ENOENT) {
167 			log_warn("unlink %s", unix_socket_path);
168 			close(fd);
169 			return -1;
170 		}
171 	}
172 
173 	old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);
174 	mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH;
175 
176 	if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
177 		log_warn("bind: %s", unix_socket_path);
178 		close(fd);
179 		umask(old_umask);
180 		return -1;
181 	}
182 
183 	umask(old_umask);
184 
185 	if (chmod(unix_socket_path, mode) == -1) {
186 		log_warn("chmod %o %s", mode, unix_socket_path);
187 		close(fd);
188 		unlink(unix_socket_path);
189 		return -1;
190 	}
191 
192 	if (chown(unix_socket_path, uid, gid) == -1) {
193 		log_warn("chown %s uid=%d gid=%d", unix_socket_path, uid, gid);
194 		close(fd);
195 		unlink(unix_socket_path);
196 		return -1;
197 	}
198 
199 	if (listen(fd, GOTD_UNIX_SOCKET_BACKLOG) == -1) {
200 		log_warn("listen");
201 		close(fd);
202 		unlink(unix_socket_path);
203 		return -1;
204 	}
205 
206 	return fd;
207 }
208 
209 static uint64_t
210 client_hash(uint32_t client_id)
211 {
212 	return SipHash24(&clients_hash_key, &client_id, sizeof(client_id));
213 }
214 
215 static void
216 add_client(struct gotd_client *client)
217 {
218 	uint64_t slot = client_hash(client->id) % nitems(gotd_clients);
219 	STAILQ_INSERT_HEAD(&gotd_clients[slot], client, entry);
220 	client_cnt++;
221 }
222 
223 static struct gotd_client *
224 find_client(uint32_t client_id)
225 {
226 	uint64_t slot;
227 	struct gotd_client *c;
228 
229 	slot = client_hash(client_id) % nitems(gotd_clients);
230 	STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
231 		if (c->id == client_id)
232 			return c;
233 	}
234 
235 	return NULL;
236 }
237 
238 static struct gotd_client *
239 find_client_by_proc_fd(int fd)
240 {
241 	uint64_t slot;
242 
243 	for (slot = 0; slot < nitems(gotd_clients); slot++) {
244 		struct gotd_client *c;
245 
246 		STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
247 			if (c->repo && c->repo->iev.ibuf.fd == fd)
248 				return c;
249 			if (c->auth && c->auth->iev.ibuf.fd == fd)
250 				return c;
251 			if (c->session && c->session->iev.ibuf.fd == fd)
252 				return c;
253 		}
254 	}
255 
256 	return NULL;
257 }
258 
259 static int
260 client_is_reading(struct gotd_client *client)
261 {
262 	return (client->required_auth &
263 	    (GOTD_AUTH_READ | GOTD_AUTH_WRITE)) == GOTD_AUTH_READ;
264 }
265 
266 static int
267 client_is_writing(struct gotd_client *client)
268 {
269 	return (client->required_auth &
270 	    (GOTD_AUTH_READ | GOTD_AUTH_WRITE)) ==
271 	    (GOTD_AUTH_READ | GOTD_AUTH_WRITE);
272 }
273 
274 static const struct got_error *
275 ensure_client_is_not_writing(struct gotd_client *client)
276 {
277 	if (client_is_writing(client)) {
278 		return got_error_fmt(GOT_ERR_BAD_PACKET,
279 		    "uid %d made a read-request but is writing to "
280 		    "a repository", client->euid);
281 	}
282 
283 	return NULL;
284 }
285 
286 static const struct got_error *
287 ensure_client_is_not_reading(struct gotd_client *client)
288 {
289 	if (client_is_reading(client)) {
290 		return got_error_fmt(GOT_ERR_BAD_PACKET,
291 		    "uid %d made a write-request but is reading from "
292 		    "a repository", client->euid);
293 	}
294 
295 	return NULL;
296 }
297 
298 static void
299 proc_done(struct gotd_child_proc *proc)
300 {
301 	struct gotd_client *client;
302 
303 	TAILQ_REMOVE(&procs, proc, entry);
304 
305 	client = find_client_by_proc_fd(proc->iev.ibuf.fd);
306 	if (client != NULL) {
307 		if (proc == client->repo)
308 			client->repo = NULL;
309 		if (proc == client->auth)
310 			client->auth = NULL;
311 		if (proc == client->session)
312 			client->session = NULL;
313 		disconnect(client);
314 	}
315 
316 	evtimer_del(&proc->tmo);
317 
318 	if (proc->iev.ibuf.fd != -1) {
319 		event_del(&proc->iev.ev);
320 		msgbuf_clear(&proc->iev.ibuf.w);
321 		close(proc->iev.ibuf.fd);
322 	}
323 
324 	free(proc);
325 }
326 
327 static void
328 kill_repo_proc(struct gotd_client *client)
329 {
330 	if (client->repo == NULL)
331 		return;
332 
333 	kill_proc(client->repo, 0);
334 	client->repo = NULL;
335 }
336 
337 static void
338 kill_auth_proc(struct gotd_client *client)
339 {
340 	if (client->auth == NULL)
341 		return;
342 
343 	kill_proc(client->auth, 0);
344 	client->auth = NULL;
345 }
346 
347 static void
348 kill_session_proc(struct gotd_client *client)
349 {
350 	if (client->session == NULL)
351 		return;
352 
353 	kill_proc(client->session, 0);
354 	client->session = NULL;
355 }
356 
357 static void
358 disconnect(struct gotd_client *client)
359 {
360 	struct gotd_imsg_disconnect idisconnect;
361 	struct gotd_child_proc *listen_proc = gotd.listen_proc;
362 	uint64_t slot;
363 
364 	log_debug("uid %d: disconnecting", client->euid);
365 
366 	kill_auth_proc(client);
367 	kill_session_proc(client);
368 	kill_repo_proc(client);
369 
370 	idisconnect.client_id = client->id;
371 	if (gotd_imsg_compose_event(&listen_proc->iev,
372 	    GOTD_IMSG_DISCONNECT, PROC_GOTD, -1,
373 	    &idisconnect, sizeof(idisconnect)) == -1)
374 		log_warn("imsg compose DISCONNECT");
375 
376 	slot = client_hash(client->id) % nitems(gotd_clients);
377 	STAILQ_REMOVE(&gotd_clients[slot], client, gotd_client, entry);
378 	imsg_clear(&client->iev.ibuf);
379 	event_del(&client->iev.ev);
380 	evtimer_del(&client->tmo);
381 	if (client->fd != -1)
382 		close(client->fd);
383 	else if (client->iev.ibuf.fd != -1)
384 		close(client->iev.ibuf.fd);
385 	free(client);
386 	client_cnt--;
387 }
388 
389 static void
390 disconnect_on_error(struct gotd_client *client, const struct got_error *err)
391 {
392 	struct imsgbuf ibuf;
393 
394 	if (err->code != GOT_ERR_EOF) {
395 		log_warnx("uid %d: %s", client->euid, err->msg);
396 		if (client->fd != -1) {
397 			imsg_init(&ibuf, client->fd);
398 			gotd_imsg_send_error(&ibuf, 0, PROC_GOTD, err);
399 			imsg_clear(&ibuf);
400 		}
401 	}
402 	disconnect(client);
403 }
404 
405 static const struct got_error *
406 send_repo_info(struct gotd_imsgev *iev, struct gotd_repo *repo)
407 {
408 	const struct got_error *err = NULL;
409 	struct gotd_imsg_info_repo irepo;
410 
411 	memset(&irepo, 0, sizeof(irepo));
412 
413 	if (strlcpy(irepo.repo_name, repo->name, sizeof(irepo.repo_name))
414 	    >= sizeof(irepo.repo_name))
415 		return got_error_msg(GOT_ERR_NO_SPACE, "repo name too long");
416 	if (strlcpy(irepo.repo_path, repo->path, sizeof(irepo.repo_path))
417 	    >= sizeof(irepo.repo_path))
418 		return got_error_msg(GOT_ERR_NO_SPACE, "repo path too long");
419 
420 	if (gotd_imsg_compose_event(iev, GOTD_IMSG_INFO_REPO, PROC_GOTD, -1,
421 	    &irepo, sizeof(irepo)) == -1) {
422 		err = got_error_from_errno("imsg compose INFO_REPO");
423 		if (err)
424 			return err;
425 	}
426 
427 	return NULL;
428 }
429 
430 static const struct got_error *
431 send_client_info(struct gotd_imsgev *iev, struct gotd_client *client)
432 {
433 	const struct got_error *err = NULL;
434 	struct gotd_imsg_info_client iclient;
435 	struct gotd_child_proc *proc;
436 
437 	memset(&iclient, 0, sizeof(iclient));
438 	iclient.euid = client->euid;
439 	iclient.egid = client->egid;
440 
441 	proc = client->repo;
442 	if (proc) {
443 		if (strlcpy(iclient.repo_name, proc->repo_path,
444 		    sizeof(iclient.repo_name)) >= sizeof(iclient.repo_name)) {
445 			return got_error_msg(GOT_ERR_NO_SPACE,
446 			    "repo name too long");
447 		}
448 		if (client_is_writing(client))
449 			iclient.is_writing = 1;
450 
451 		iclient.repo_child_pid = proc->pid;
452 	}
453 
454 	if (client->session)
455 		iclient.session_child_pid = client->session->pid;
456 
457 	if (gotd_imsg_compose_event(iev, GOTD_IMSG_INFO_CLIENT, PROC_GOTD, -1,
458 	    &iclient, sizeof(iclient)) == -1) {
459 		err = got_error_from_errno("imsg compose INFO_CLIENT");
460 		if (err)
461 			return err;
462 	}
463 
464 	return NULL;
465 }
466 
467 static const struct got_error *
468 send_info(struct gotd_client *client)
469 {
470 	const struct got_error *err = NULL;
471 	struct gotd_imsg_info info;
472 	uint64_t slot;
473 	struct gotd_repo *repo;
474 
475 	if (client->euid != 0)
476 		return got_error_set_errno(EPERM, "info");
477 
478 	info.pid = gotd.pid;
479 	info.verbosity = gotd.verbosity;
480 	info.nrepos = gotd.nrepos;
481 	info.nclients = client_cnt - 1;
482 
483 	if (gotd_imsg_compose_event(&client->iev, GOTD_IMSG_INFO, PROC_GOTD, -1,
484 	    &info, sizeof(info)) == -1) {
485 		err = got_error_from_errno("imsg compose INFO");
486 		if (err)
487 			return err;
488 	}
489 
490 	TAILQ_FOREACH(repo, &gotd.repos, entry) {
491 		err = send_repo_info(&client->iev, repo);
492 		if (err)
493 			return err;
494 	}
495 
496 	for (slot = 0; slot < nitems(gotd_clients); slot++) {
497 		struct gotd_client *c;
498 		STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
499 			if (c->id == client->id)
500 				continue;
501 			err = send_client_info(&client->iev, c);
502 			if (err)
503 				return err;
504 		}
505 	}
506 
507 	return NULL;
508 }
509 
510 static const struct got_error *
511 stop_gotd(struct gotd_client *client)
512 {
513 
514 	if (client->euid != 0)
515 		return got_error_set_errno(EPERM, "stop");
516 
517 	gotd_shutdown();
518 	/* NOTREACHED */
519 	return NULL;
520 }
521 
522 static const struct got_error *
523 start_client_authentication(struct gotd_client *client, struct imsg *imsg)
524 {
525 	const struct got_error *err;
526 	struct gotd_imsg_list_refs ireq;
527 	struct gotd_repo *repo = NULL;
528 	size_t datalen;
529 
530 	log_debug("list-refs request from uid %d", client->euid);
531 
532 	if (client->state != GOTD_CLIENT_STATE_NEW)
533 		return got_error_msg(GOT_ERR_BAD_REQUEST,
534 		    "unexpected list-refs request received");
535 
536 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
537 	if (datalen != sizeof(ireq))
538 		return got_error(GOT_ERR_PRIVSEP_LEN);
539 
540 	memcpy(&ireq, imsg->data, datalen);
541 
542 	if (ireq.client_is_reading) {
543 		err = ensure_client_is_not_writing(client);
544 		if (err)
545 			return err;
546 		repo = gotd_find_repo_by_name(ireq.repo_name, &gotd);
547 		if (repo == NULL)
548 			return got_error(GOT_ERR_NOT_GIT_REPO);
549 		err = start_auth_child(client, GOTD_AUTH_READ, repo,
550 		    gotd.argv0, gotd.confpath, gotd.daemonize,
551 		    gotd.verbosity);
552 		if (err)
553 			return err;
554 	} else {
555 		err = ensure_client_is_not_reading(client);
556 		if (err)
557 			return err;
558 		repo = gotd_find_repo_by_name(ireq.repo_name, &gotd);
559 		if (repo == NULL)
560 			return got_error(GOT_ERR_NOT_GIT_REPO);
561 		err = start_auth_child(client,
562 		    GOTD_AUTH_READ | GOTD_AUTH_WRITE,
563 		    repo, gotd.argv0, gotd.confpath, gotd.daemonize,
564 		    gotd.verbosity);
565 		if (err)
566 			return err;
567 	}
568 
569 	evtimer_add(&client->tmo, &auth_timeout);
570 
571 	/* Flow continues upon authentication success/failure or timeout. */
572 	return NULL;
573 }
574 
575 static void
576 gotd_request(int fd, short events, void *arg)
577 {
578 	struct gotd_imsgev *iev = arg;
579 	struct imsgbuf *ibuf = &iev->ibuf;
580 	struct gotd_client *client = iev->handler_arg;
581 	const struct got_error *err = NULL;
582 	struct imsg imsg;
583 	ssize_t n;
584 
585 	if (events & EV_WRITE) {
586 		while (ibuf->w.queued) {
587 			n = msgbuf_write(&ibuf->w);
588 			if (n == -1 && errno == EPIPE) {
589 				/*
590 				 * The client has closed its socket.
591 				 * This can happen when Git clients are
592 				 * done sending pack file data.
593 				 */
594 				msgbuf_clear(&ibuf->w);
595 				continue;
596 			} else if (n == -1 && errno != EAGAIN) {
597 				err = got_error_from_errno("imsg_flush");
598 				disconnect_on_error(client, err);
599 				return;
600 			}
601 			if (n == 0) {
602 				/* Connection closed. */
603 				err = got_error(GOT_ERR_EOF);
604 				disconnect_on_error(client, err);
605 				return;
606 			}
607 		}
608 
609 		/* Disconnect gotctl(8) now that messages have been sent. */
610 		if (!client_is_reading(client) && !client_is_writing(client)) {
611 			disconnect(client);
612 			return;
613 		}
614 	}
615 
616 	if ((events & EV_READ) == 0)
617 		return;
618 
619 	memset(&imsg, 0, sizeof(imsg));
620 
621 	while (err == NULL) {
622 		err = gotd_imsg_recv(&imsg, ibuf, 0);
623 		if (err) {
624 			if (err->code == GOT_ERR_PRIVSEP_READ)
625 				err = NULL;
626 			break;
627 		}
628 
629 		evtimer_del(&client->tmo);
630 
631 		switch (imsg.hdr.type) {
632 		case GOTD_IMSG_INFO:
633 			err = send_info(client);
634 			break;
635 		case GOTD_IMSG_STOP:
636 			err = stop_gotd(client);
637 			break;
638 		case GOTD_IMSG_LIST_REFS:
639 			err = start_client_authentication(client, &imsg);
640 			break;
641 		default:
642 			log_debug("unexpected imsg %d", imsg.hdr.type);
643 			err = got_error(GOT_ERR_PRIVSEP_MSG);
644 			break;
645 		}
646 
647 		imsg_free(&imsg);
648 	}
649 
650 	if (err) {
651 		disconnect_on_error(client, err);
652 	} else {
653 		gotd_imsg_event_add(&client->iev);
654 	}
655 }
656 
657 static void
658 gotd_auth_timeout(int fd, short events, void *arg)
659 {
660 	struct gotd_client *client = arg;
661 
662 	log_debug("disconnecting uid %d due to authentication timeout",
663 	    client->euid);
664 	disconnect(client);
665 }
666 
667 static const struct got_error *
668 recv_connect(uint32_t *client_id, struct imsg *imsg)
669 {
670 	const struct got_error *err = NULL;
671 	struct gotd_imsg_connect iconnect;
672 	size_t datalen;
673 	int s = -1;
674 	struct gotd_client *client = NULL;
675 
676 	*client_id = 0;
677 
678 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
679 	if (datalen != sizeof(iconnect))
680 		return got_error(GOT_ERR_PRIVSEP_LEN);
681 	memcpy(&iconnect, imsg->data, sizeof(iconnect));
682 
683 	s = imsg->fd;
684 	if (s == -1) {
685 		err = got_error(GOT_ERR_PRIVSEP_NO_FD);
686 		goto done;
687 	}
688 
689 	if (find_client(iconnect.client_id)) {
690 		err = got_error_msg(GOT_ERR_CLIENT_ID, "duplicate client ID");
691 		goto done;
692 	}
693 
694 	client = calloc(1, sizeof(*client));
695 	if (client == NULL) {
696 		err = got_error_from_errno("calloc");
697 		goto done;
698 	}
699 
700 	*client_id = iconnect.client_id;
701 
702 	client->state = GOTD_CLIENT_STATE_NEW;
703 	client->id = iconnect.client_id;
704 	client->fd = s;
705 	s = -1;
706 	/* The auth process will verify UID/GID for us. */
707 	client->euid = iconnect.euid;
708 	client->egid = iconnect.egid;
709 
710 	imsg_init(&client->iev.ibuf, client->fd);
711 	client->iev.handler = gotd_request;
712 	client->iev.events = EV_READ;
713 	client->iev.handler_arg = client;
714 
715 	event_set(&client->iev.ev, client->fd, EV_READ, gotd_request,
716 	    &client->iev);
717 	gotd_imsg_event_add(&client->iev);
718 
719 	evtimer_set(&client->tmo, gotd_auth_timeout, client);
720 
721 	add_client(client);
722 	log_debug("%s: new client uid %d connected on fd %d", __func__,
723 	    client->euid, client->fd);
724 done:
725 	if (err) {
726 		struct gotd_child_proc *listen_proc = gotd.listen_proc;
727 		struct gotd_imsg_disconnect idisconnect;
728 
729 		idisconnect.client_id = client->id;
730 		if (gotd_imsg_compose_event(&listen_proc->iev,
731 		    GOTD_IMSG_DISCONNECT, PROC_GOTD, -1,
732 		    &idisconnect, sizeof(idisconnect)) == -1)
733 			log_warn("imsg compose DISCONNECT");
734 
735 		if (s != -1)
736 			close(s);
737 	}
738 
739 	return err;
740 }
741 
742 static const char *gotd_proc_names[PROC_MAX] = {
743 	"parent",
744 	"listen",
745 	"auth",
746 	"session_read",
747 	"session_write",
748 	"repo_read",
749 	"repo_write",
750 	"gitwrapper"
751 };
752 
753 static void
754 kill_proc(struct gotd_child_proc *proc, int fatal)
755 {
756 	struct timeval tv = { 5, 0 };
757 
758 	log_debug("kill -%d %d", fatal ? SIGKILL : SIGTERM, proc->pid);
759 
760 	if (proc->iev.ibuf.fd != -1) {
761 		event_del(&proc->iev.ev);
762 		msgbuf_clear(&proc->iev.ibuf.w);
763 		close(proc->iev.ibuf.fd);
764 		proc->iev.ibuf.fd = -1;
765 	}
766 
767 	if (!evtimer_pending(&proc->tmo, NULL) && !fatal)
768 		evtimer_add(&proc->tmo, &tv);
769 
770 	if (fatal) {
771 		log_warnx("sending SIGKILL to PID %d", proc->pid);
772 		kill(proc->pid, SIGKILL);
773 	} else
774 		kill(proc->pid, SIGTERM);
775 }
776 
777 static void
778 kill_proc_timeout(int fd, short ev, void *d)
779 {
780 	struct gotd_child_proc *proc = d;
781 
782 	log_warnx("timeout waiting for PID %d to terminate;"
783 	    " retrying with force", proc->pid);
784 	kill_proc(proc, 1);
785 }
786 
787 static void
788 gotd_shutdown(void)
789 {
790 	uint64_t slot;
791 
792 	log_debug("shutting down");
793 	for (slot = 0; slot < nitems(gotd_clients); slot++) {
794 		struct gotd_client *c, *tmp;
795 
796 		STAILQ_FOREACH_SAFE(c, &gotd_clients[slot], entry, tmp)
797 			disconnect(c);
798 	}
799 
800 	kill_proc(gotd.listen_proc, 0);
801 
802 	log_info("terminating");
803 	exit(0);
804 }
805 
806 static struct gotd_child_proc *
807 find_proc_by_pid(pid_t pid)
808 {
809 	struct gotd_child_proc *proc = NULL;
810 
811 	TAILQ_FOREACH(proc, &procs, entry)
812 		if (proc->pid == pid)
813 			break;
814 
815 	return proc;
816 }
817 
818 void
819 gotd_sighdlr(int sig, short event, void *arg)
820 {
821 	struct gotd_child_proc *proc;
822 	pid_t pid;
823 	int status;
824 
825 	/*
826 	 * Normal signal handler rules don't apply because libevent
827 	 * decouples for us.
828 	 */
829 
830 	switch (sig) {
831 	case SIGHUP:
832 		log_info("%s: ignoring SIGHUP", __func__);
833 		break;
834 	case SIGUSR1:
835 		log_info("%s: ignoring SIGUSR1", __func__);
836 		break;
837 	case SIGTERM:
838 	case SIGINT:
839 		gotd_shutdown();
840 		break;
841 	case SIGCHLD:
842 		for (;;) {
843 			pid = waitpid(WAIT_ANY, &status, WNOHANG);
844 			if (pid == -1) {
845 				if (errno == EINTR)
846 					continue;
847 				if (errno == ECHILD)
848 					break;
849 				fatal("waitpid");
850 			}
851 			if (pid == 0)
852 				break;
853 
854 			log_debug("reaped pid %d", pid);
855 			proc = find_proc_by_pid(pid);
856 			if (proc == NULL) {
857 				log_info("caught exit of unknown child %d",
858 				    pid);
859 				continue;
860 			}
861 
862 			if (WIFSIGNALED(status)) {
863 				log_warnx("child PID %d terminated with"
864 				    " signal %d", pid, WTERMSIG(status));
865 			}
866 
867 			proc_done(proc);
868 		}
869 		break;
870 	default:
871 		fatalx("unexpected signal");
872 	}
873 }
874 
875 static const struct got_error *
876 ensure_proc_is_reading(struct gotd_client *client,
877     struct gotd_child_proc *proc)
878 {
879 	if (!client_is_reading(client)) {
880 		kill_proc(proc, 1);
881 		return got_error_fmt(GOT_ERR_BAD_PACKET,
882 		    "PID %d handled a read-request for uid %d but this "
883 		    "user is not reading from a repository", proc->pid,
884 		    client->euid);
885 	}
886 
887 	return NULL;
888 }
889 
890 static const struct got_error *
891 ensure_proc_is_writing(struct gotd_client *client,
892     struct gotd_child_proc *proc)
893 {
894 	if (!client_is_writing(client)) {
895 		kill_proc(proc, 1);
896 		return got_error_fmt(GOT_ERR_BAD_PACKET,
897 		    "PID %d handled a write-request for uid %d but this "
898 		    "user is not writing to a repository", proc->pid,
899 		    client->euid);
900 	}
901 
902 	return NULL;
903 }
904 
905 static int
906 verify_imsg_src(struct gotd_client *client, struct gotd_child_proc *proc,
907     struct imsg *imsg)
908 {
909 	const struct got_error *err;
910 	int ret = 0;
911 
912 	if (proc->type == PROC_REPO_READ || proc->type == PROC_REPO_WRITE) {
913 		if (client->repo == NULL)
914 			fatalx("no process found for uid %d", client->euid);
915 		if (proc->pid != client->repo->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->repo->pid);
920 			return 0;
921 		}
922 	}
923 	if (proc->type == PROC_SESSION_READ ||
924 	    proc->type == PROC_SESSION_WRITE) {
925 		if (client->session == NULL) {
926 			log_warnx("no session found for uid %d", client->euid);
927 			return 0;
928 		}
929 		if (proc->pid != client->session->pid) {
930 			kill_proc(proc, 1);
931 			log_warnx("received message from PID %d for uid %d, "
932 			    "while PID %d is the process serving this user",
933 			    proc->pid, client->euid, client->session->pid);
934 			return 0;
935 		}
936 	}
937 
938 	switch (imsg->hdr.type) {
939 	case GOTD_IMSG_ERROR:
940 		ret = 1;
941 		break;
942 	case GOTD_IMSG_CONNECT:
943 		if (proc->type != PROC_LISTEN) {
944 			err = got_error_fmt(GOT_ERR_BAD_PACKET,
945 			    "new connection for uid %d from PID %d "
946 			    "which is not the listen process",
947 			    proc->pid, client->euid);
948 		} else
949 			ret = 1;
950 		break;
951 	case GOTD_IMSG_ACCESS_GRANTED:
952 		if (proc->type != PROC_AUTH) {
953 			err = got_error_fmt(GOT_ERR_BAD_PACKET,
954 			    "authentication of uid %d from PID %d "
955 			    "which is not the auth process",
956 			    proc->pid, client->euid);
957 		} else
958 			ret = 1;
959 		break;
960 	case GOTD_IMSG_CLIENT_SESSION_READY:
961 		if (proc->type != PROC_SESSION_READ &&
962 		    proc->type != PROC_SESSION_WRITE) {
963 			err = got_error_fmt(GOT_ERR_BAD_PACKET,
964 			    "unexpected \"ready\" signal from PID %d",
965 			    proc->pid);
966 		} else
967 			ret = 1;
968 		break;
969 	case GOTD_IMSG_REPO_CHILD_READY:
970 		if (proc->type != PROC_REPO_READ &&
971 		    proc->type != PROC_REPO_WRITE) {
972 			err = got_error_fmt(GOT_ERR_BAD_PACKET,
973 			    "unexpected \"ready\" signal from PID %d",
974 			    proc->pid);
975 		} else
976 			ret = 1;
977 		break;
978 	case GOTD_IMSG_PACKFILE_DONE:
979 		err = ensure_proc_is_reading(client, proc);
980 		if (err)
981 			log_warnx("uid %d: %s", client->euid, err->msg);
982 		else
983 			ret = 1;
984 		break;
985 	case GOTD_IMSG_PACKFILE_INSTALL:
986 	case GOTD_IMSG_REF_UPDATES_START:
987 	case GOTD_IMSG_REF_UPDATE:
988 		err = ensure_proc_is_writing(client, proc);
989 		if (err)
990 			log_warnx("uid %d: %s", client->euid, err->msg);
991 		else
992 			ret = 1;
993 		break;
994 	default:
995 		log_debug("%s: unexpected imsg %d", __func__, imsg->hdr.type);
996 		break;
997 	}
998 
999 	return ret;
1000 }
1001 
1002 static const struct got_error *
1003 connect_repo_child(struct gotd_client *client,
1004     struct gotd_child_proc *repo_proc)
1005 {
1006 	static const struct got_error *err;
1007 	struct gotd_imsgev *session_iev = &client->session->iev;
1008 	struct gotd_imsg_connect_repo_child ireq;
1009 	int pipe[2];
1010 	int sock_flags = SOCK_STREAM | SOCK_NONBLOCK;
1011 
1012 #ifdef SOCK_CLOEXEC
1013 	sock_flags |= SOCK_CLOEXEC;
1014 #endif
1015 
1016 	if (client->state != GOTD_CLIENT_STATE_ACCESS_GRANTED)
1017 		return got_error_msg(GOT_ERR_BAD_REQUEST,
1018 		    "unexpected repo child ready signal received");
1019 
1020 	if (socketpair(AF_UNIX, sock_flags, PF_UNSPEC, pipe) == -1)
1021 		fatal("socketpair");
1022 
1023 	memset(&ireq, 0, sizeof(ireq));
1024 	ireq.client_id = client->id;
1025 	ireq.proc_id = repo_proc->type;
1026 
1027 	/* Pass repo child pipe to session child process. */
1028 	if (gotd_imsg_compose_event(session_iev, GOTD_IMSG_CONNECT_REPO_CHILD,
1029 	    PROC_GOTD, pipe[0], &ireq, sizeof(ireq)) == -1) {
1030 		err = got_error_from_errno("imsg compose CONNECT_REPO_CHILD");
1031 		close(pipe[0]);
1032 		close(pipe[1]);
1033 		return err;
1034 	}
1035 
1036 	/* Pass session child pipe to repo child process. */
1037 	if (gotd_imsg_compose_event(&repo_proc->iev,
1038 	    GOTD_IMSG_CONNECT_REPO_CHILD, PROC_GOTD, pipe[1], NULL, 0) == -1) {
1039 		err = got_error_from_errno("imsg compose CONNECT_REPO_CHILD");
1040 		close(pipe[1]);
1041 		return err;
1042 	}
1043 
1044 	return NULL;
1045 }
1046 
1047 static void
1048 gotd_dispatch_listener(int fd, short event, void *arg)
1049 {
1050 	struct gotd_imsgev *iev = arg;
1051 	struct imsgbuf *ibuf = &iev->ibuf;
1052 	struct gotd_child_proc *proc = gotd.listen_proc;
1053 	ssize_t n;
1054 	int shut = 0;
1055 	struct imsg imsg;
1056 
1057 	if (proc->iev.ibuf.fd != fd)
1058 		fatalx("%s: unexpected fd %d", __func__, fd);
1059 
1060 	if (event & EV_READ) {
1061 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1062 			fatal("imsg_read error");
1063 		if (n == 0) {
1064 			/* Connection closed. */
1065 			shut = 1;
1066 			goto done;
1067 		}
1068 	}
1069 
1070 	if (event & EV_WRITE) {
1071 		n = msgbuf_write(&ibuf->w);
1072 		if (n == -1 && errno != EAGAIN)
1073 			fatal("msgbuf_write");
1074 		if (n == 0) {
1075 			/* Connection closed. */
1076 			shut = 1;
1077 			goto done;
1078 		}
1079 	}
1080 
1081 	for (;;) {
1082 		const struct got_error *err = NULL;
1083 		struct gotd_client *client = NULL;
1084 		uint32_t client_id = 0;
1085 		int do_disconnect = 0;
1086 
1087 		if ((n = imsg_get(ibuf, &imsg)) == -1)
1088 			fatal("%s: imsg_get error", __func__);
1089 		if (n == 0)	/* No more messages. */
1090 			break;
1091 
1092 		switch (imsg.hdr.type) {
1093 		case GOTD_IMSG_ERROR:
1094 			do_disconnect = 1;
1095 			err = gotd_imsg_recv_error(&client_id, &imsg);
1096 			break;
1097 		case GOTD_IMSG_CONNECT:
1098 			err = recv_connect(&client_id, &imsg);
1099 			break;
1100 		default:
1101 			log_debug("unexpected imsg %d", imsg.hdr.type);
1102 			break;
1103 		}
1104 
1105 		client = find_client(client_id);
1106 		if (client == NULL) {
1107 			log_warnx("%s: client not found", __func__);
1108 			imsg_free(&imsg);
1109 			continue;
1110 		}
1111 
1112 		if (err)
1113 			log_warnx("uid %d: %s", client->euid, err->msg);
1114 
1115 		if (do_disconnect) {
1116 			if (err)
1117 				disconnect_on_error(client, err);
1118 			else
1119 				disconnect(client);
1120 		}
1121 
1122 		imsg_free(&imsg);
1123 	}
1124 done:
1125 	if (!shut) {
1126 		gotd_imsg_event_add(iev);
1127 	} else {
1128 		/* This pipe is dead. Remove its event handler */
1129 		event_del(&iev->ev);
1130 		event_loopexit(NULL);
1131 	}
1132 }
1133 
1134 static void
1135 gotd_dispatch_auth_child(int fd, short event, void *arg)
1136 {
1137 	const struct got_error *err = NULL;
1138 	struct gotd_imsgev *iev = arg;
1139 	struct imsgbuf *ibuf = &iev->ibuf;
1140 	struct gotd_client *client;
1141 	struct gotd_repo *repo = NULL;
1142 	ssize_t n;
1143 	int shut = 0;
1144 	struct imsg imsg;
1145 	uint32_t client_id = 0;
1146 	int do_disconnect = 0;
1147 
1148 	client = find_client_by_proc_fd(fd);
1149 	if (client == NULL) {
1150 		/* Can happen during process teardown. */
1151 		warnx("cannot find client for fd %d", fd);
1152 		shut = 1;
1153 		goto done;
1154 	}
1155 
1156 	if (client->auth == NULL)
1157 		fatalx("cannot find auth child process for fd %d", fd);
1158 
1159 	if (event & EV_READ) {
1160 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1161 			fatal("imsg_read error");
1162 		if (n == 0) {
1163 			/* Connection closed. */
1164 			shut = 1;
1165 			goto done;
1166 		}
1167 	}
1168 
1169 	if (event & EV_WRITE) {
1170 		n = msgbuf_write(&ibuf->w);
1171 		if (n == -1 && errno != EAGAIN)
1172 			fatal("msgbuf_write");
1173 		if (n == 0) {
1174 			/* Connection closed. */
1175 			shut = 1;
1176 		}
1177 		goto done;
1178 	}
1179 
1180 	if (client->auth->iev.ibuf.fd != fd)
1181 		fatalx("%s: unexpected fd %d", __func__, fd);
1182 
1183 	if ((n = imsg_get(ibuf, &imsg)) == -1)
1184 		fatal("%s: imsg_get error", __func__);
1185 	if (n == 0)	/* No more messages. */
1186 		return;
1187 
1188 	evtimer_del(&client->tmo);
1189 
1190 	switch (imsg.hdr.type) {
1191 	case GOTD_IMSG_ERROR:
1192 		do_disconnect = 1;
1193 		err = gotd_imsg_recv_error(&client_id, &imsg);
1194 		break;
1195 	case GOTD_IMSG_ACCESS_GRANTED:
1196 		client->state = GOTD_CLIENT_STATE_ACCESS_GRANTED;
1197 		break;
1198 	default:
1199 		do_disconnect = 1;
1200 		log_debug("unexpected imsg %d", imsg.hdr.type);
1201 		break;
1202 	}
1203 
1204 	if (!verify_imsg_src(client, client->auth, &imsg)) {
1205 		do_disconnect = 1;
1206 		log_debug("dropping imsg type %d from PID %d",
1207 		    imsg.hdr.type, client->auth->pid);
1208 	}
1209 	imsg_free(&imsg);
1210 
1211 	if (do_disconnect) {
1212 		if (err)
1213 			disconnect_on_error(client, err);
1214 		else
1215 			disconnect(client);
1216 		return;
1217 	}
1218 
1219 	repo = gotd_find_repo_by_name(client->auth->repo_name, &gotd);
1220 	if (repo == NULL) {
1221 		err = got_error(GOT_ERR_NOT_GIT_REPO);
1222 		goto done;
1223 	}
1224 	kill_auth_proc(client);
1225 
1226 	log_info("authenticated uid %d for repository %s",
1227 	    client->euid, repo->name);
1228 
1229 	err = start_session_child(client, repo, gotd.argv0,
1230 	    gotd.confpath, gotd.daemonize, gotd.verbosity);
1231 	if (err)
1232 		goto done;
1233 done:
1234 	if (err)
1235 		log_warnx("uid %d: %s", client->euid, err->msg);
1236 
1237 	/* We might have killed the auth process by now. */
1238 	if (client->auth != NULL) {
1239 		if (!shut) {
1240 			gotd_imsg_event_add(iev);
1241 		} else {
1242 			/* This pipe is dead. Remove its event handler */
1243 			event_del(&iev->ev);
1244 		}
1245 	}
1246 }
1247 
1248 static const struct got_error *
1249 connect_session(struct gotd_client *client)
1250 {
1251 	const struct got_error *err = NULL;
1252 	struct gotd_imsg_connect iconnect;
1253 	int s;
1254 
1255 	memset(&iconnect, 0, sizeof(iconnect));
1256 
1257 	s = dup(client->fd);
1258 	if (s == -1)
1259 		return got_error_from_errno("dup");
1260 
1261 	iconnect.client_id = client->id;
1262 	iconnect.euid = client->euid;
1263 	iconnect.egid = client->egid;
1264 
1265 	if (gotd_imsg_compose_event(&client->session->iev, GOTD_IMSG_CONNECT,
1266 	    PROC_GOTD, s, &iconnect, sizeof(iconnect)) == -1) {
1267 		err = got_error_from_errno("imsg compose CONNECT");
1268 		close(s);
1269 		return err;
1270 	}
1271 
1272 	/*
1273 	 * We are no longer interested in messages from this client.
1274 	 * Further client requests will be handled by the session process.
1275 	 */
1276 	msgbuf_clear(&client->iev.ibuf.w);
1277 	imsg_clear(&client->iev.ibuf);
1278 	event_del(&client->iev.ev);
1279 	client->fd = -1; /* will be closed via copy in client->iev.ibuf.fd */
1280 
1281 	return NULL;
1282 }
1283 
1284 static void
1285 gotd_dispatch_client_session(int fd, short event, void *arg)
1286 {
1287 	struct gotd_imsgev *iev = arg;
1288 	struct imsgbuf *ibuf = &iev->ibuf;
1289 	struct gotd_child_proc *proc = NULL;
1290 	struct gotd_client *client = NULL;
1291 	ssize_t n;
1292 	int shut = 0;
1293 	struct imsg imsg;
1294 
1295 	client = find_client_by_proc_fd(fd);
1296 	if (client == NULL) {
1297 		/* Can happen during process teardown. */
1298 		warnx("cannot find client for fd %d", fd);
1299 		shut = 1;
1300 		goto done;
1301 	}
1302 
1303 	if (event & EV_READ) {
1304 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1305 			fatal("imsg_read error");
1306 		if (n == 0) {
1307 			/* Connection closed. */
1308 			shut = 1;
1309 			goto done;
1310 		}
1311 	}
1312 
1313 	if (event & EV_WRITE) {
1314 		n = msgbuf_write(&ibuf->w);
1315 		if (n == -1 && errno != EAGAIN)
1316 			fatal("msgbuf_write");
1317 		if (n == 0) {
1318 			/* Connection closed. */
1319 			shut = 1;
1320 			goto done;
1321 		}
1322 	}
1323 
1324 	proc = client->session;
1325 	if (proc == NULL)
1326 		fatalx("cannot find session child process for fd %d", fd);
1327 
1328 	for (;;) {
1329 		const struct got_error *err = NULL;
1330 		uint32_t client_id = 0;
1331 		int do_disconnect = 0, do_start_repo_child = 0;
1332 
1333 		if ((n = imsg_get(ibuf, &imsg)) == -1)
1334 			fatal("%s: imsg_get error", __func__);
1335 		if (n == 0)	/* No more messages. */
1336 			break;
1337 
1338 		switch (imsg.hdr.type) {
1339 		case GOTD_IMSG_ERROR:
1340 			do_disconnect = 1;
1341 			err = gotd_imsg_recv_error(&client_id, &imsg);
1342 			break;
1343 		case GOTD_IMSG_CLIENT_SESSION_READY:
1344 			if (client->state != GOTD_CLIENT_STATE_ACCESS_GRANTED) {
1345 				err = got_error(GOT_ERR_PRIVSEP_MSG);
1346 				break;
1347 			}
1348 			do_start_repo_child = 1;
1349 			break;
1350 		case GOTD_IMSG_DISCONNECT:
1351 			do_disconnect = 1;
1352 			break;
1353 		default:
1354 			log_debug("unexpected imsg %d", imsg.hdr.type);
1355 			break;
1356 		}
1357 
1358 		if (!verify_imsg_src(client, proc, &imsg)) {
1359 			log_debug("dropping imsg type %d from PID %d",
1360 			    imsg.hdr.type, proc->pid);
1361 			imsg_free(&imsg);
1362 			continue;
1363 		}
1364 		if (err)
1365 			log_warnx("uid %d: %s", client->euid, err->msg);
1366 
1367 		if (do_start_repo_child) {
1368 			struct gotd_repo *repo;
1369 			const char *name = client->session->repo_name;
1370 
1371 			repo = gotd_find_repo_by_name(name, &gotd);
1372 			if (repo != NULL) {
1373 				enum gotd_procid proc_type;
1374 
1375 				if (client->required_auth & GOTD_AUTH_WRITE)
1376 					proc_type = PROC_REPO_WRITE;
1377 				else
1378 					proc_type = PROC_REPO_READ;
1379 
1380 				err = start_repo_child(client, proc_type, repo,
1381 				    gotd.argv0, gotd.confpath, gotd.daemonize,
1382 				    gotd.verbosity);
1383 			} else
1384 				err = got_error(GOT_ERR_NOT_GIT_REPO);
1385 
1386 			if (err) {
1387 				log_warnx("uid %d: %s", client->euid, err->msg);
1388 				do_disconnect = 1;
1389 			}
1390 		}
1391 
1392 		if (do_disconnect) {
1393 			if (err)
1394 				disconnect_on_error(client, err);
1395 			else
1396 				disconnect(client);
1397 		}
1398 
1399 		imsg_free(&imsg);
1400 	}
1401 done:
1402 	if (!shut) {
1403 		gotd_imsg_event_add(iev);
1404 	} else {
1405 		/* This pipe is dead. Remove its event handler */
1406 		event_del(&iev->ev);
1407 		disconnect(client);
1408 	}
1409 }
1410 
1411 static void
1412 gotd_dispatch_repo_child(int fd, short event, void *arg)
1413 {
1414 	struct gotd_imsgev *iev = arg;
1415 	struct imsgbuf *ibuf = &iev->ibuf;
1416 	struct gotd_child_proc *proc = NULL;
1417 	struct gotd_client *client;
1418 	ssize_t n;
1419 	int shut = 0;
1420 	struct imsg imsg;
1421 
1422 	client = find_client_by_proc_fd(fd);
1423 	if (client == NULL) {
1424 		/* Can happen during process teardown. */
1425 		warnx("cannot find client for fd %d", fd);
1426 		shut = 1;
1427 		goto done;
1428 	}
1429 
1430 	if (event & EV_READ) {
1431 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1432 			fatal("imsg_read error");
1433 		if (n == 0) {
1434 			/* Connection closed. */
1435 			shut = 1;
1436 			goto done;
1437 		}
1438 	}
1439 
1440 	if (event & EV_WRITE) {
1441 		n = msgbuf_write(&ibuf->w);
1442 		if (n == -1 && errno != EAGAIN)
1443 			fatal("msgbuf_write");
1444 		if (n == 0) {
1445 			/* Connection closed. */
1446 			shut = 1;
1447 			goto done;
1448 		}
1449 	}
1450 
1451 	proc = client->repo;
1452 	if (proc == NULL)
1453 		fatalx("cannot find child process for fd %d", fd);
1454 
1455 	for (;;) {
1456 		const struct got_error *err = NULL;
1457 		uint32_t client_id = 0;
1458 		int do_disconnect = 0;
1459 
1460 		if ((n = imsg_get(ibuf, &imsg)) == -1)
1461 			fatal("%s: imsg_get error", __func__);
1462 		if (n == 0)	/* No more messages. */
1463 			break;
1464 
1465 		switch (imsg.hdr.type) {
1466 		case GOTD_IMSG_ERROR:
1467 			do_disconnect = 1;
1468 			err = gotd_imsg_recv_error(&client_id, &imsg);
1469 			break;
1470 		case GOTD_IMSG_REPO_CHILD_READY:
1471 			err = connect_session(client);
1472 			if (err)
1473 				break;
1474 			err = connect_repo_child(client, proc);
1475 			break;
1476 		default:
1477 			log_debug("unexpected imsg %d", imsg.hdr.type);
1478 			break;
1479 		}
1480 
1481 		if (!verify_imsg_src(client, proc, &imsg)) {
1482 			log_debug("dropping imsg type %d from PID %d",
1483 			    imsg.hdr.type, proc->pid);
1484 			imsg_free(&imsg);
1485 			continue;
1486 		}
1487 		if (err)
1488 			log_warnx("uid %d: %s", client->euid, err->msg);
1489 
1490 		if (do_disconnect) {
1491 			if (err)
1492 				disconnect_on_error(client, err);
1493 			else
1494 				disconnect(client);
1495 		}
1496 
1497 		imsg_free(&imsg);
1498 	}
1499 done:
1500 	if (!shut) {
1501 		gotd_imsg_event_add(iev);
1502 	} else {
1503 		/* This pipe is dead. Remove its event handler */
1504 		event_del(&iev->ev);
1505 		disconnect(client);
1506 	}
1507 }
1508 
1509 static pid_t
1510 start_child(enum gotd_procid proc_id, const char *repo_path,
1511     char *argv0, const char *confpath, int fd, int daemonize, int verbosity)
1512 {
1513 	char	*argv[11];
1514 	int	 argc = 0;
1515 	pid_t	 pid;
1516 
1517 	switch (pid = fork()) {
1518 	case -1:
1519 		fatal("cannot fork");
1520 	case 0:
1521 		break;
1522 	default:
1523 		close(fd);
1524 		return pid;
1525 	}
1526 
1527 	if (fd != GOTD_FILENO_MSG_PIPE) {
1528 		if (dup2(fd, GOTD_FILENO_MSG_PIPE) == -1)
1529 			fatal("cannot setup imsg fd");
1530 	} else if (fcntl(fd, F_SETFD, 0) == -1)
1531 		fatal("cannot setup imsg fd");
1532 
1533 	argv[argc++] = argv0;
1534 	switch (proc_id) {
1535 	case PROC_LISTEN:
1536 		argv[argc++] = (char *)"-L";
1537 		break;
1538 	case PROC_AUTH:
1539 		argv[argc++] = (char *)"-A";
1540 		break;
1541 	case PROC_SESSION_READ:
1542 		argv[argc++] = (char *)"-s";
1543 		break;
1544 	case PROC_SESSION_WRITE:
1545 		argv[argc++] = (char *)"-S";
1546 		break;
1547 	case PROC_REPO_READ:
1548 		argv[argc++] = (char *)"-R";
1549 		break;
1550 	case PROC_REPO_WRITE:
1551 		argv[argc++] = (char *)"-W";
1552 		break;
1553 	default:
1554 		fatalx("invalid process id %d", proc_id);
1555 	}
1556 
1557 	argv[argc++] = (char *)"-f";
1558 	argv[argc++] = (char *)confpath;
1559 
1560 	if (repo_path) {
1561 		argv[argc++] = (char *)"-P";
1562 		argv[argc++] = (char *)repo_path;
1563 	}
1564 
1565 	if (!daemonize)
1566 		argv[argc++] = (char *)"-d";
1567 	if (verbosity > 0)
1568 		argv[argc++] = (char *)"-v";
1569 	if (verbosity > 1)
1570 		argv[argc++] = (char *)"-v";
1571 	argv[argc++] = NULL;
1572 
1573 	execvp(argv0, argv);
1574 	fatal("execvp");
1575 }
1576 
1577 static void
1578 start_listener(char *argv0, const char *confpath, int daemonize, int verbosity)
1579 {
1580 	struct gotd_child_proc *proc;
1581 	int sock_flags = SOCK_STREAM|SOCK_NONBLOCK;
1582 
1583 #ifdef SOCK_CLOEXEC
1584 	sock_flags |= SOCK_CLOEXEC;
1585 #endif
1586 
1587 	proc = calloc(1, sizeof(*proc));
1588 	if (proc == NULL)
1589 		fatal("calloc");
1590 
1591 	TAILQ_INSERT_HEAD(&procs, proc, entry);
1592 
1593 	/* proc->tmo is initialized in main() after event_init() */
1594 
1595 	proc->type = PROC_LISTEN;
1596 
1597 	if (socketpair(AF_UNIX, sock_flags,
1598 	    PF_UNSPEC, proc->pipe) == -1)
1599 		fatal("socketpair");
1600 
1601 	proc->pid = start_child(proc->type, NULL, argv0, confpath,
1602 	    proc->pipe[1], daemonize, verbosity);
1603 	imsg_init(&proc->iev.ibuf, proc->pipe[0]);
1604 	proc->iev.handler = gotd_dispatch_listener;
1605 	proc->iev.events = EV_READ;
1606 	proc->iev.handler_arg = NULL;
1607 
1608 	gotd.listen_proc = proc;
1609 }
1610 
1611 static const struct got_error *
1612 start_session_child(struct gotd_client *client, struct gotd_repo *repo,
1613     char *argv0, const char *confpath, int daemonize, int verbosity)
1614 {
1615 	struct gotd_child_proc *proc;
1616 	int sock_flags = SOCK_STREAM | SOCK_NONBLOCK;
1617 
1618 #ifdef SOCK_CLOEXEC
1619 	sock_flags |= SOCK_CLOEXEC;
1620 #endif
1621 
1622 	proc = calloc(1, sizeof(*proc));
1623 	if (proc == NULL)
1624 		return got_error_from_errno("calloc");
1625 
1626 	TAILQ_INSERT_HEAD(&procs, proc, entry);
1627 	evtimer_set(&proc->tmo, kill_proc_timeout, proc);
1628 
1629 	if (client_is_reading(client))
1630 		proc->type = PROC_SESSION_READ;
1631 	else
1632 		proc->type = PROC_SESSION_WRITE;
1633 	if (strlcpy(proc->repo_name, repo->name,
1634 	    sizeof(proc->repo_name)) >= sizeof(proc->repo_name))
1635 		fatalx("repository name too long: %s", repo->name);
1636 	log_debug("starting client uid %d session for repository %s",
1637 	    client->euid, repo->name);
1638 	if (strlcpy(proc->repo_path, repo->path, sizeof(proc->repo_path)) >=
1639 	    sizeof(proc->repo_path))
1640 		fatalx("repository path too long: %s", repo->path);
1641 	if (socketpair(AF_UNIX, sock_flags, PF_UNSPEC, proc->pipe) == -1)
1642 		fatal("socketpair");
1643 	proc->pid = start_child(proc->type, proc->repo_path, argv0,
1644 	    confpath, proc->pipe[1], daemonize, verbosity);
1645 	imsg_init(&proc->iev.ibuf, proc->pipe[0]);
1646 	log_debug("proc %s %s is on fd %d",
1647 	    gotd_proc_names[proc->type], proc->repo_path,
1648 	    proc->pipe[0]);
1649 	proc->iev.handler = gotd_dispatch_client_session;
1650 	proc->iev.events = EV_READ;
1651 	proc->iev.handler_arg = NULL;
1652 	event_set(&proc->iev.ev, proc->iev.ibuf.fd, EV_READ,
1653 	    gotd_dispatch_client_session, &proc->iev);
1654 	gotd_imsg_event_add(&proc->iev);
1655 
1656 	client->session = proc;
1657 	return NULL;
1658 }
1659 
1660 static const struct got_error *
1661 start_repo_child(struct gotd_client *client, enum gotd_procid proc_type,
1662     struct gotd_repo *repo, char *argv0, const char *confpath,
1663     int daemonize, int verbosity)
1664 {
1665 	struct gotd_child_proc *proc;
1666 	int sock_flags = SOCK_STREAM|SOCK_NONBLOCK;
1667 
1668 #ifdef SOCK_CLOEXEC
1669 	sock_flags |= SOCK_CLOEXEC;
1670 #endif
1671 
1672 	if (proc_type != PROC_REPO_READ && proc_type != PROC_REPO_WRITE)
1673 		return got_error_msg(GOT_ERR_NOT_IMPL, "bad process type");
1674 
1675 	proc = calloc(1, sizeof(*proc));
1676 	if (proc == NULL)
1677 		return got_error_from_errno("calloc");
1678 
1679 	TAILQ_INSERT_HEAD(&procs, proc, entry);
1680 	evtimer_set(&proc->tmo, kill_proc_timeout, proc);
1681 
1682 	proc->type = proc_type;
1683 	if (strlcpy(proc->repo_name, repo->name,
1684 	    sizeof(proc->repo_name)) >= sizeof(proc->repo_name))
1685 		fatalx("repository name too long: %s", repo->name);
1686 	log_debug("starting %s for repository %s",
1687 	    proc->type == PROC_REPO_READ ? "reader" : "writer", repo->name);
1688 
1689 	if (strlcpy(proc->repo_path, repo->path, sizeof(proc->repo_path)) >=
1690 	    sizeof(proc->repo_path))
1691 		fatalx("repository path too long: %s", repo->path);
1692 	if (realpath(repo->path, proc->repo_path) == NULL)
1693 		fatal("%s", repo->path);
1694 	if (socketpair(AF_UNIX, sock_flags,
1695 	    PF_UNSPEC, proc->pipe) == -1)
1696 		fatal("socketpair");
1697 	proc->pid = start_child(proc->type, proc->repo_path, argv0,
1698 	    confpath, proc->pipe[1], daemonize, verbosity);
1699 	imsg_init(&proc->iev.ibuf, proc->pipe[0]);
1700 	log_debug("proc %s %s is on fd %d",
1701 	    gotd_proc_names[proc->type], proc->repo_path,
1702 	    proc->pipe[0]);
1703 	proc->iev.handler = gotd_dispatch_repo_child;
1704 	proc->iev.events = EV_READ;
1705 	proc->iev.handler_arg = NULL;
1706 	event_set(&proc->iev.ev, proc->iev.ibuf.fd, EV_READ,
1707 	    gotd_dispatch_repo_child, &proc->iev);
1708 	gotd_imsg_event_add(&proc->iev);
1709 
1710 	client->repo = proc;
1711 	return NULL;
1712 }
1713 
1714 static const struct got_error *
1715 start_auth_child(struct gotd_client *client, int required_auth,
1716     struct gotd_repo *repo, char *argv0, const char *confpath,
1717     int daemonize, int verbosity)
1718 {
1719 	const struct got_error *err = NULL;
1720 	struct gotd_child_proc *proc;
1721 	struct gotd_imsg_auth iauth;
1722 	int fd;
1723 	int sock_flags = SOCK_STREAM|SOCK_NONBLOCK;
1724 
1725 #ifdef SOCK_CLOEXEC
1726 	sock_flags |= SOCK_CLOEXEC;
1727 #endif
1728 
1729 	memset(&iauth, 0, sizeof(iauth));
1730 
1731 	fd = dup(client->fd);
1732 	if (fd == -1)
1733 		return got_error_from_errno("dup");
1734 
1735 	proc = calloc(1, sizeof(*proc));
1736 	if (proc == NULL) {
1737 		err = got_error_from_errno("calloc");
1738 		close(fd);
1739 		return err;
1740 	}
1741 
1742 	TAILQ_INSERT_HEAD(&procs, proc, entry);
1743 	evtimer_set(&proc->tmo, kill_proc_timeout, proc);
1744 
1745 	proc->type = PROC_AUTH;
1746 	if (strlcpy(proc->repo_name, repo->name,
1747 	    sizeof(proc->repo_name)) >= sizeof(proc->repo_name))
1748 		fatalx("repository name too long: %s", repo->name);
1749 	log_debug("starting auth for uid %d repository %s",
1750 	    client->euid, repo->name);
1751 	if (strlcpy(proc->repo_path, repo->path, sizeof(proc->repo_path)) >=
1752 	    sizeof(proc->repo_path))
1753 		fatalx("repository path too long: %s", repo->path);
1754 	if (realpath(repo->path, proc->repo_path) == NULL)
1755 		fatal("%s", repo->path);
1756 	if (socketpair(AF_UNIX, sock_flags,
1757 	    PF_UNSPEC, proc->pipe) == -1)
1758 		fatal("socketpair");
1759 	proc->pid = start_child(proc->type, proc->repo_path, argv0,
1760 	    confpath, proc->pipe[1], daemonize, verbosity);
1761 	imsg_init(&proc->iev.ibuf, proc->pipe[0]);
1762 	log_debug("proc %s %s is on fd %d",
1763 	    gotd_proc_names[proc->type], proc->repo_path,
1764 	    proc->pipe[0]);
1765 	proc->iev.handler = gotd_dispatch_auth_child;
1766 	proc->iev.events = EV_READ;
1767 	proc->iev.handler_arg = NULL;
1768 	event_set(&proc->iev.ev, proc->iev.ibuf.fd, EV_READ,
1769 	    gotd_dispatch_auth_child, &proc->iev);
1770 	gotd_imsg_event_add(&proc->iev);
1771 
1772 	iauth.euid = client->euid;
1773 	iauth.egid = client->egid;
1774 	iauth.required_auth = required_auth;
1775 	iauth.client_id = client->id;
1776 	if (gotd_imsg_compose_event(&proc->iev, GOTD_IMSG_AUTHENTICATE,
1777 	    PROC_GOTD, fd, &iauth, sizeof(iauth)) == -1) {
1778 		log_warn("imsg compose AUTHENTICATE");
1779 		close(fd);
1780 		/* Let the auth_timeout handler tidy up. */
1781 	}
1782 
1783 	client->auth = proc;
1784 	client->required_auth = required_auth;
1785 	return NULL;
1786 }
1787 
1788 static void
1789 apply_unveil_repo_readonly(const char *repo_path, int need_tmpdir)
1790 {
1791 	if (need_tmpdir) {
1792 		if (unveil(GOT_TMPDIR_STR, "rwc") == -1)
1793 			fatal("unveil %s", GOT_TMPDIR_STR);
1794 	}
1795 
1796 	if (unveil(repo_path, "r") == -1)
1797 		fatal("unveil %s", repo_path);
1798 
1799 	if (unveil(NULL, NULL) == -1)
1800 		fatal("unveil");
1801 }
1802 
1803 static void
1804 apply_unveil_repo_readwrite(const char *repo_path)
1805 {
1806 	if (unveil(repo_path, "rwc") == -1)
1807 		fatal("unveil %s", repo_path);
1808 
1809 	if (unveil(GOT_TMPDIR_STR, "rwc") == -1)
1810 		fatal("unveil %s", GOT_TMPDIR_STR);
1811 
1812 	if (unveil(NULL, NULL) == -1)
1813 		fatal("unveil");
1814 }
1815 
1816 static void
1817 apply_unveil_none(void)
1818 {
1819 	if (unveil("/", "") == -1)
1820 		fatal("unveil");
1821 
1822 	if (unveil(NULL, NULL) == -1)
1823 		fatal("unveil");
1824 }
1825 
1826 static void
1827 apply_unveil_selfexec(void)
1828 {
1829 	if (unveil(gotd.argv0, "x") == -1)
1830 		fatal("unveil %s", gotd.argv0);
1831 
1832 	if (unveil(NULL, NULL) == -1)
1833 		fatal("unveil");
1834 }
1835 
1836 static void
1837 set_max_datasize(void)
1838 {
1839 	struct rlimit rl;
1840 
1841 	if (getrlimit(RLIMIT_DATA, &rl) != 0)
1842 		return;
1843 
1844 	rl.rlim_cur = rl.rlim_max;
1845 	setrlimit(RLIMIT_DATA, &rl);
1846 }
1847 
1848 int
1849 main(int argc, char **argv)
1850 {
1851 	const struct got_error *error = NULL;
1852 	int ch, fd = -1, daemonize = 1, verbosity = 0, noaction = 0;
1853 	const char *confpath = GOTD_CONF_PATH;
1854 	char *argv0 = argv[0];
1855 	char title[2048];
1856 	struct passwd *pw = NULL;
1857 	char *repo_path = NULL;
1858 	enum gotd_procid proc_id = PROC_GOTD;
1859 	struct event evsigint, evsigterm, evsighup, evsigusr1, evsigchld;
1860 	int *pack_fds = NULL, *temp_fds = NULL;
1861 	struct gotd_repo *repo = NULL;
1862 
1863 	TAILQ_INIT(&procs);
1864 
1865 	log_init(1, LOG_DAEMON); /* Log to stderr until daemonized. */
1866 
1867 	while ((ch = getopt(argc, argv, "Adf:LnP:RsSvW")) != -1) {
1868 		switch (ch) {
1869 		case 'A':
1870 			proc_id = PROC_AUTH;
1871 			break;
1872 		case 'd':
1873 			daemonize = 0;
1874 			break;
1875 		case 'f':
1876 			confpath = optarg;
1877 			break;
1878 		case 'L':
1879 			proc_id = PROC_LISTEN;
1880 			break;
1881 		case 'n':
1882 			noaction = 1;
1883 			break;
1884 		case 'P':
1885 			repo_path = realpath(optarg, NULL);
1886 			if (repo_path == NULL)
1887 				fatal("realpath '%s'", optarg);
1888 			break;
1889 		case 'R':
1890 			proc_id = PROC_REPO_READ;
1891 			break;
1892 		case 's':
1893 			proc_id = PROC_SESSION_READ;
1894 			break;
1895 		case 'S':
1896 			proc_id = PROC_SESSION_WRITE;
1897 			break;
1898 		case 'v':
1899 			if (verbosity < 3)
1900 				verbosity++;
1901 			break;
1902 		case 'W':
1903 			proc_id = PROC_REPO_WRITE;
1904 			break;
1905 		default:
1906 			usage();
1907 		}
1908 	}
1909 
1910 	argc -= optind;
1911 	argv += optind;
1912 
1913 	if (argc != 0)
1914 		usage();
1915 
1916 	if (geteuid() && (proc_id == PROC_GOTD || proc_id == PROC_LISTEN))
1917 		fatalx("need root privileges");
1918 
1919 	if (parse_config(confpath, proc_id, &gotd) != 0)
1920 		return 1;
1921 
1922 	pw = getpwnam(gotd.user_name);
1923 	if (pw == NULL)
1924 		fatalx("user %s not found", gotd.user_name);
1925 
1926 	if (pw->pw_uid == 0)
1927 		fatalx("cannot run %s as the superuser", getprogname());
1928 
1929 	if (noaction) {
1930 		fprintf(stderr, "configuration OK\n");
1931 		return 0;
1932 	}
1933 
1934 	gotd.argv0 = argv0;
1935 	gotd.daemonize = daemonize;
1936 	gotd.verbosity = verbosity;
1937 	gotd.confpath = confpath;
1938 
1939 	/* Require an absolute path in argv[0] for reliable re-exec. */
1940 	if (!got_path_is_absolute(argv0))
1941 		fatalx("bad path \"%s\": must be an absolute path", argv0);
1942 
1943 	log_init(daemonize ? 0 : 1, LOG_DAEMON);
1944 	log_setverbose(verbosity);
1945 
1946 	if (proc_id == PROC_GOTD) {
1947 		snprintf(title, sizeof(title), "%s", gotd_proc_names[proc_id]);
1948 		arc4random_buf(&clients_hash_key, sizeof(clients_hash_key));
1949 		if (daemonize && daemon(1, 0) == -1)
1950 			fatal("daemon");
1951 		gotd.pid = getpid();
1952 		start_listener(argv0, confpath, daemonize, verbosity);
1953 	} else if (proc_id == PROC_LISTEN) {
1954 		snprintf(title, sizeof(title), "%s", gotd_proc_names[proc_id]);
1955 		if (verbosity) {
1956 			log_info("socket: %s", gotd.unix_socket_path);
1957 			log_info("user: %s", pw->pw_name);
1958 		}
1959 
1960 		fd = unix_socket_listen(gotd.unix_socket_path, pw->pw_uid,
1961 		    pw->pw_gid);
1962 		if (fd == -1) {
1963 			fatal("cannot listen on unix socket %s",
1964 			    gotd.unix_socket_path);
1965 		}
1966 	} else if (proc_id == PROC_AUTH) {
1967 		snprintf(title, sizeof(title), "%s %s",
1968 		    gotd_proc_names[proc_id], repo_path);
1969 	} else if (proc_id == PROC_REPO_READ || proc_id == PROC_REPO_WRITE ||
1970 	    proc_id == PROC_SESSION_READ || proc_id == PROC_SESSION_WRITE) {
1971 		error = got_repo_pack_fds_open(&pack_fds);
1972 		if (error != NULL)
1973 			fatalx("cannot open pack tempfiles: %s", error->msg);
1974 		error = got_repo_temp_fds_open(&temp_fds);
1975 		if (error != NULL)
1976 			fatalx("cannot open pack tempfiles: %s", error->msg);
1977 		if (repo_path == NULL)
1978 			fatalx("repository path not specified");
1979 		snprintf(title, sizeof(title), "%s %s",
1980 		    gotd_proc_names[proc_id], repo_path);
1981 	} else
1982 		fatal("invalid process id %d", proc_id);
1983 
1984 	setproctitle("%s", title);
1985 	log_procinit(title);
1986 
1987 	if (proc_id != PROC_GOTD && proc_id != PROC_LISTEN &&
1988 	    proc_id != PROC_REPO_READ && proc_id != PROC_REPO_WRITE) {
1989 		/* Drop root privileges. */
1990 		if (setgid(pw->pw_gid) == -1)
1991 			fatal("setgid %d failed", pw->pw_gid);
1992 		if (setuid(pw->pw_uid) == -1)
1993 			fatal("setuid %d failed", pw->pw_uid);
1994 	}
1995 
1996 	event_init();
1997 
1998 	switch (proc_id) {
1999 	case PROC_GOTD:
2000 #ifndef PROFILE
2001 		/* "exec" promise will be limited to argv[0] via unveil(2). */
2002 		if (pledge("stdio proc exec sendfd recvfd unveil", NULL) == -1)
2003 			err(1, "pledge");
2004 #endif
2005 		break;
2006 	case PROC_LISTEN:
2007 #ifndef PROFILE
2008 		if (pledge("stdio sendfd unix unveil", NULL) == -1)
2009 			err(1, "pledge");
2010 #endif
2011 		/*
2012 		 * Ensure that AF_UNIX bind(2) cannot be used with any other
2013 		 * sockets by revoking all filesystem access via unveil(2).
2014 		 */
2015 		apply_unveil_none();
2016 
2017 		enter_chroot(GOTD_EMPTY_PATH);
2018 		drop_privs(pw);
2019 
2020 		listen_main(title, fd, gotd.connection_limits,
2021 		    gotd.nconnection_limits);
2022 		/* NOTREACHED */
2023 		break;
2024 	case PROC_AUTH:
2025 #ifndef PROFILE
2026 		if (pledge("stdio getpw recvfd unix unveil", NULL) == -1)
2027 			err(1, "pledge");
2028 #endif
2029 		/*
2030 		 * We need the "unix" pledge promise for getpeername(2) only.
2031 		 * Ensure that AF_UNIX bind(2) cannot be used by revoking all
2032 		 * filesystem access via unveil(2). Access to password database
2033 		 * files will still work since "getpw" bypasses unveil(2).
2034 		 */
2035 		apply_unveil_none();
2036 
2037 		auth_main(title, &gotd.repos, repo_path);
2038 		/* NOTREACHED */
2039 		break;
2040 	case PROC_SESSION_READ:
2041 	case PROC_SESSION_WRITE:
2042 #ifndef PROFILE
2043 		/*
2044 		 * The "recvfd" promise is only needed during setup and
2045 		 * will be removed in a later pledge(2) call.
2046 		 */
2047 		if (pledge("stdio rpath wpath cpath recvfd sendfd fattr flock "
2048 		    "unveil", NULL) == -1)
2049 			err(1, "pledge");
2050 #endif
2051 		if (proc_id == PROC_SESSION_READ)
2052 			apply_unveil_repo_readonly(repo_path, 1);
2053 		else
2054 			apply_unveil_repo_readwrite(repo_path);
2055 
2056 		session_main(title, repo_path, pack_fds, temp_fds,
2057 		    &gotd.request_timeout, proc_id);
2058 		/* NOTREACHED */
2059 		break;
2060 	case PROC_REPO_READ:
2061 		set_max_datasize();
2062 #ifndef PROFILE
2063 		if (pledge("stdio rpath recvfd unveil", NULL) == -1)
2064 			err(1, "pledge");
2065 #endif
2066 		apply_unveil_repo_readonly(repo_path, 0);
2067 
2068 		if (enter_chroot(repo_path)) {
2069 			log_info("change repo path %s", repo_path);
2070 			free(repo_path);
2071 			repo_path = strdup("/");
2072 			if (repo_path == NULL)
2073 				fatal("strdup");
2074 			log_info("repo path is now %s", repo_path);
2075 		}
2076 		drop_privs(pw);
2077 
2078 		repo_read_main(title, repo_path, pack_fds, temp_fds);
2079 		/* NOTREACHED */
2080 		exit(0);
2081 	case PROC_REPO_WRITE:
2082 		set_max_datasize();
2083 #ifndef PROFILE
2084 		if (pledge("stdio rpath recvfd unveil", NULL) == -1)
2085 			err(1, "pledge");
2086 #endif
2087 		apply_unveil_repo_readonly(repo_path, 0);
2088 		repo = gotd_find_repo_by_path(repo_path, &gotd);
2089 		if (repo == NULL)
2090 			fatalx("no repository for path %s", repo_path);
2091 
2092 		if (enter_chroot(repo_path)) {
2093 			free(repo_path);
2094 			repo_path = strdup("/");
2095 			if (repo_path == NULL)
2096 				fatal("strdup");
2097 		}
2098 		drop_privs(pw);
2099 
2100 		repo_write_main(title, repo_path, pack_fds, temp_fds,
2101 		    &repo->protected_tag_namespaces,
2102 		    &repo->protected_branch_namespaces,
2103 		    &repo->protected_branches);
2104 		/* NOTREACHED */
2105 		exit(0);
2106 	default:
2107 		fatal("invalid process id %d", proc_id);
2108 	}
2109 
2110 	if (proc_id != PROC_GOTD)
2111 		fatal("invalid process id %d", proc_id);
2112 
2113 	evtimer_set(&gotd.listen_proc->tmo, kill_proc_timeout,
2114 	    gotd.listen_proc);
2115 
2116 	apply_unveil_selfexec();
2117 
2118 	signal_set(&evsigint, SIGINT, gotd_sighdlr, NULL);
2119 	signal_set(&evsigterm, SIGTERM, gotd_sighdlr, NULL);
2120 	signal_set(&evsighup, SIGHUP, gotd_sighdlr, NULL);
2121 	signal_set(&evsigusr1, SIGUSR1, gotd_sighdlr, NULL);
2122 	signal_set(&evsigchld, SIGCHLD, gotd_sighdlr, NULL);
2123 	signal(SIGPIPE, SIG_IGN);
2124 
2125 	signal_add(&evsigint, NULL);
2126 	signal_add(&evsigterm, NULL);
2127 	signal_add(&evsighup, NULL);
2128 	signal_add(&evsigusr1, NULL);
2129 	signal_add(&evsigchld, NULL);
2130 
2131 	gotd_imsg_event_add(&gotd.listen_proc->iev);
2132 
2133 	event_dispatch();
2134 
2135 	free(repo_path);
2136 	gotd_shutdown();
2137 
2138 	return 0;
2139 }