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Date:: Wed Jan 4 21:12:08 2023 UTC
Message:: revoke filesystem access in gotd listen process via unveil(2) This should avoid involuntary use of bind(2) with arbitrary socket paths. ok op@
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1 /*
2  * Copyright (c) 2022 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/queue.h>
18 #include <sys/tree.h>
19 #include <sys/time.h>
20 #include <sys/types.h>
21 #include <sys/stat.h>
22 #include <sys/socket.h>
23 #include <sys/un.h>
24 #include <sys/wait.h>
25 
26 #include <fcntl.h>
27 #include <err.h>
28 #include <errno.h>
29 #include <event.h>
30 #include <limits.h>
31 #include <pwd.h>
32 #include <imsg.h>
33 #include <sha1.h>
34 #include <signal.h>
35 #include <siphash.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_sha1.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 "repo_read.h"
63 #include "repo_write.h"
64 
65 #ifndef nitems
66 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
67 #endif
68 
69 struct gotd_client {
70 	STAILQ_ENTRY(gotd_client)	 entry;
71 	enum gotd_client_state		 state;
72 	struct gotd_client_capability	*capabilities;
73 	size_t				 ncapa_alloc;
74 	size_t				 ncapabilities;
75 	uint32_t			 id;
76 	int				 fd;
77 	int				 delta_cache_fd;
78 	struct gotd_imsgev		 iev;
79 	struct event			 tmo;
80 	uid_t				 euid;
81 	gid_t				 egid;
82 	struct gotd_child_proc		*repo_read;
83 	struct gotd_child_proc		*repo_write;
84 	struct gotd_child_proc		*auth;
85 	int				 required_auth;
86 	char				*packfile_path;
87 	char				*packidx_path;
88 	int				 nref_updates;
89 };
90 STAILQ_HEAD(gotd_clients, gotd_client);
91 
92 static struct gotd_clients gotd_clients[GOTD_CLIENT_TABLE_SIZE];
93 static SIPHASH_KEY clients_hash_key;
94 volatile int client_cnt;
95 static struct timeval auth_timeout = { 5, 0 };
96 static struct gotd gotd;
97 
98 void gotd_sighdlr(int sig, short event, void *arg);
99 static void gotd_shutdown(void);
100 static const struct got_error *start_repo_child(struct gotd_client *,
101     enum gotd_procid, struct gotd_repo *, char *, const char *, int, int);
102 static const struct got_error *start_auth_child(struct gotd_client *, int,
103     struct gotd_repo *, char *, const char *, int, int);
104 static void kill_proc(struct gotd_child_proc *, int);
105 
106 __dead static void
107 usage()
108 {
109 	fprintf(stderr, "usage: %s [-dv] [-f config-file]\n", getprogname());
110 	exit(1);
111 }
112 
113 static int
114 unix_socket_listen(const char *unix_socket_path, uid_t uid, gid_t gid)
115 {
116 	struct sockaddr_un sun;
117 	int fd = -1;
118 	mode_t old_umask, mode;
119 
120 	fd = socket(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK| SOCK_CLOEXEC, 0);
121 	if (fd == -1) {
122 		log_warn("socket");
123 		return -1;
124 	}
125 
126 	sun.sun_family = AF_UNIX;
127 	if (strlcpy(sun.sun_path, unix_socket_path,
128 	    sizeof(sun.sun_path)) >= sizeof(sun.sun_path)) {
129 		log_warnx("%s: name too long", unix_socket_path);
130 		close(fd);
131 		return -1;
132 	}
133 
134 	if (unlink(unix_socket_path) == -1) {
135 		if (errno != ENOENT) {
136 			log_warn("unlink %s", unix_socket_path);
137 			close(fd);
138 			return -1;
139 		}
140 	}
141 
142 	old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);
143 	mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH;
144 
145 	if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
146 		log_warn("bind: %s", unix_socket_path);
147 		close(fd);
148 		umask(old_umask);
149 		return -1;
150 	}
151 
152 	umask(old_umask);
153 
154 	if (chmod(unix_socket_path, mode) == -1) {
155 		log_warn("chmod %o %s", mode, unix_socket_path);
156 		close(fd);
157 		unlink(unix_socket_path);
158 		return -1;
159 	}
160 
161 	if (chown(unix_socket_path, uid, gid) == -1) {
162 		log_warn("chown %s uid=%d gid=%d", unix_socket_path, uid, gid);
163 		close(fd);
164 		unlink(unix_socket_path);
165 		return -1;
166 	}
167 
168 	if (listen(fd, GOTD_UNIX_SOCKET_BACKLOG) == -1) {
169 		log_warn("listen");
170 		close(fd);
171 		unlink(unix_socket_path);
172 		return -1;
173 	}
174 
175 	return fd;
176 }
177 
178 static uint64_t
179 client_hash(uint32_t client_id)
180 {
181 	return SipHash24(&clients_hash_key, &client_id, sizeof(client_id));
182 }
183 
184 static void
185 add_client(struct gotd_client *client)
186 {
187 	uint64_t slot = client_hash(client->id) % nitems(gotd_clients);
188 	STAILQ_INSERT_HEAD(&gotd_clients[slot], client, entry);
189 	client_cnt++;
190 }
191 
192 static struct gotd_client *
193 find_client(uint32_t client_id)
194 {
195 	uint64_t slot;
196 	struct gotd_client *c;
197 
198 	slot = client_hash(client_id) % nitems(gotd_clients);
199 	STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
200 		if (c->id == client_id)
201 			return c;
202 	}
203 
204 	return NULL;
205 }
206 
207 static struct gotd_child_proc *
208 get_client_proc(struct gotd_client *client)
209 {
210 	if (client->repo_read && client->repo_write) {
211 		fatalx("uid %d is reading and writing in the same session",
212 		    client->euid);
213 		/* NOTREACHED */
214 	}
215 
216 	if (client->repo_read)
217 		return client->repo_read;
218 	else if (client->repo_write)
219 		return client->repo_write;
220 
221 	return NULL;
222 }
223 
224 static struct gotd_client *
225 find_client_by_proc_fd(int fd)
226 {
227 	uint64_t slot;
228 
229 	for (slot = 0; slot < nitems(gotd_clients); slot++) {
230 		struct gotd_client *c;
231 
232 		STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
233 			struct gotd_child_proc *proc = get_client_proc(c);
234 			if (proc && proc->iev.ibuf.fd == fd)
235 				return c;
236 			if (c->auth && c->auth->iev.ibuf.fd == fd)
237 				return c;
238 		}
239 	}
240 
241 	return NULL;
242 }
243 
244 static int
245 client_is_reading(struct gotd_client *client)
246 {
247 	return client->repo_read != NULL;
248 }
249 
250 static int
251 client_is_writing(struct gotd_client *client)
252 {
253 	return client->repo_write != NULL;
254 }
255 
256 static const struct got_error *
257 ensure_client_is_reading(struct gotd_client *client)
258 {
259 	if (!client_is_reading(client)) {
260 		return got_error_fmt(GOT_ERR_BAD_PACKET,
261 		    "uid %d made a read-request but is not reading from "
262 		    "a repository", client->euid);
263 	}
264 
265 	return NULL;
266 }
267 
268 static const struct got_error *
269 ensure_client_is_writing(struct gotd_client *client)
270 {
271 	if (!client_is_writing(client)) {
272 		return got_error_fmt(GOT_ERR_BAD_PACKET,
273 		    "uid %d made a write-request but is not writing to "
274 		    "a repository", client->euid);
275 	}
276 
277 	return NULL;
278 }
279 
280 static const struct got_error *
281 ensure_client_is_not_writing(struct gotd_client *client)
282 {
283 	if (client_is_writing(client)) {
284 		return got_error_fmt(GOT_ERR_BAD_PACKET,
285 		    "uid %d made a read-request but is writing to "
286 		    "a repository", client->euid);
287 	}
288 
289 	return NULL;
290 }
291 
292 static const struct got_error *
293 ensure_client_is_not_reading(struct gotd_client *client)
294 {
295 	if (client_is_reading(client)) {
296 		return got_error_fmt(GOT_ERR_BAD_PACKET,
297 		    "uid %d made a write-request but is reading from "
298 		    "a repository", client->euid);
299 	}
300 
301 	return NULL;
302 }
303 
304 static void
305 wait_for_child(pid_t child_pid)
306 {
307 	pid_t pid;
308 	int status;
309 
310 	log_debug("waiting for child PID %ld to terminate",
311 	    (long)child_pid);
312 
313 	do {
314 		pid = waitpid(child_pid, &status, WNOHANG);
315 		if (pid == -1) {
316 			if (errno != EINTR && errno != ECHILD)
317 				fatal("wait");
318 		} else if (WIFSIGNALED(status)) {
319 			log_warnx("child PID %ld terminated; signal %d",
320 			    (long)pid, WTERMSIG(status));
321 		}
322 	} while (pid != -1 || (pid == -1 && errno == EINTR));
323 }
324 
325 static void
326 kill_auth_proc(struct gotd_client *client)
327 {
328 	struct gotd_child_proc *proc;
329 
330 	if (client->auth == NULL)
331 		return;
332 
333 	proc = client->auth;
334 	client->auth = NULL;
335 
336 	event_del(&proc->iev.ev);
337 	msgbuf_clear(&proc->iev.ibuf.w);
338 	close(proc->iev.ibuf.fd);
339 	kill_proc(proc, 0);
340 	wait_for_child(proc->pid);
341 	free(proc);
342 }
343 
344 static void
345 disconnect(struct gotd_client *client)
346 {
347 	struct gotd_imsg_disconnect idisconnect;
348 	struct gotd_child_proc *proc = get_client_proc(client);
349 	struct gotd_child_proc *listen_proc = &gotd.listen_proc;
350 	uint64_t slot;
351 
352 	log_debug("uid %d: disconnecting", client->euid);
353 
354 	kill_auth_proc(client);
355 
356 	idisconnect.client_id = client->id;
357 	if (proc) {
358 		if (gotd_imsg_compose_event(&proc->iev,
359 		    GOTD_IMSG_DISCONNECT, PROC_GOTD, -1,
360 		    &idisconnect, sizeof(idisconnect)) == -1)
361 			log_warn("imsg compose DISCONNECT");
362 
363 		msgbuf_clear(&proc->iev.ibuf.w);
364 		close(proc->iev.ibuf.fd);
365 		kill_proc(proc, 0);
366 		wait_for_child(proc->pid);
367 		free(proc);
368 		proc = NULL;
369 	}
370 
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 	close(client->fd);
382 	if (client->delta_cache_fd != -1)
383 		close(client->delta_cache_fd);
384 	if (client->packfile_path) {
385 		if (unlink(client->packfile_path) == -1 && errno != ENOENT)
386 			log_warn("unlink %s: ", client->packfile_path);
387 		free(client->packfile_path);
388 	}
389 	if (client->packidx_path) {
390 		if (unlink(client->packidx_path) == -1 && errno != ENOENT)
391 			log_warn("unlink %s: ", client->packidx_path);
392 		free(client->packidx_path);
393 	}
394 	free(client->capabilities);
395 	free(client);
396 	client_cnt--;
397 }
398 
399 static void
400 disconnect_on_error(struct gotd_client *client, const struct got_error *err)
401 {
402 	struct imsgbuf ibuf;
403 
404 	log_warnx("uid %d: %s", client->euid, err->msg);
405 	if (err->code != GOT_ERR_EOF) {
406 		imsg_init(&ibuf, client->fd);
407 		gotd_imsg_send_error(&ibuf, 0, PROC_GOTD, err);
408 		imsg_clear(&ibuf);
409 	}
410 	disconnect(client);
411 }
412 
413 static const struct got_error *
414 send_repo_info(struct gotd_imsgev *iev, struct gotd_repo *repo)
415 {
416 	const struct got_error *err = NULL;
417 	struct gotd_imsg_info_repo irepo;
418 
419 	memset(&irepo, 0, sizeof(irepo));
420 
421 	if (strlcpy(irepo.repo_name, repo->name, sizeof(irepo.repo_name))
422 	    >= sizeof(irepo.repo_name))
423 		return got_error_msg(GOT_ERR_NO_SPACE, "repo name too long");
424 	if (strlcpy(irepo.repo_path, repo->path, sizeof(irepo.repo_path))
425 	    >= sizeof(irepo.repo_path))
426 		return got_error_msg(GOT_ERR_NO_SPACE, "repo path too long");
427 
428 	if (gotd_imsg_compose_event(iev, GOTD_IMSG_INFO_REPO, PROC_GOTD, -1,
429 	    &irepo, sizeof(irepo)) == -1) {
430 		err = got_error_from_errno("imsg compose INFO_REPO");
431 		if (err)
432 			return err;
433 	}
434 
435 	return NULL;
436 }
437 
438 static const struct got_error *
439 send_capability(struct gotd_client_capability *capa, struct gotd_imsgev* iev)
440 {
441 	const struct got_error *err = NULL;
442 	struct gotd_imsg_capability icapa;
443 	size_t len;
444 	struct ibuf *wbuf;
445 
446 	memset(&icapa, 0, sizeof(icapa));
447 
448 	icapa.key_len = strlen(capa->key);
449 	len = sizeof(icapa) + icapa.key_len;
450 	if (capa->value) {
451 		icapa.value_len = strlen(capa->value);
452 		len += icapa.value_len;
453 	}
454 
455 	wbuf = imsg_create(&iev->ibuf, GOTD_IMSG_CAPABILITY, 0, 0, len);
456 	if (wbuf == NULL) {
457 		err = got_error_from_errno("imsg_create CAPABILITY");
458 		return err;
459 	}
460 
461 	if (imsg_add(wbuf, &icapa, sizeof(icapa)) == -1)
462 		return got_error_from_errno("imsg_add CAPABILITY");
463 	if (imsg_add(wbuf, capa->key, icapa.key_len) == -1)
464 		return got_error_from_errno("imsg_add CAPABILITY");
465 	if (capa->value) {
466 		if (imsg_add(wbuf, capa->value, icapa.value_len) == -1)
467 			return got_error_from_errno("imsg_add CAPABILITY");
468 	}
469 
470 	wbuf->fd = -1;
471 	imsg_close(&iev->ibuf, wbuf);
472 
473 	gotd_imsg_event_add(iev);
474 
475 	return NULL;
476 }
477 
478 static const struct got_error *
479 send_client_info(struct gotd_imsgev *iev, struct gotd_client *client)
480 {
481 	const struct got_error *err = NULL;
482 	struct gotd_imsg_info_client iclient;
483 	struct gotd_child_proc *proc;
484 	size_t i;
485 
486 	memset(&iclient, 0, sizeof(iclient));
487 	iclient.euid = client->euid;
488 	iclient.egid = client->egid;
489 
490 	proc = get_client_proc(client);
491 	if (proc) {
492 		if (strlcpy(iclient.repo_name, proc->repo_path,
493 		    sizeof(iclient.repo_name)) >= sizeof(iclient.repo_name)) {
494 			return got_error_msg(GOT_ERR_NO_SPACE,
495 			    "repo name too long");
496 		}
497 		if (client_is_writing(client))
498 			iclient.is_writing = 1;
499 	}
500 
501 	iclient.state = client->state;
502 	iclient.ncapabilities = client->ncapabilities;
503 
504 	if (gotd_imsg_compose_event(iev, GOTD_IMSG_INFO_CLIENT, PROC_GOTD, -1,
505 	    &iclient, sizeof(iclient)) == -1) {
506 		err = got_error_from_errno("imsg compose INFO_CLIENT");
507 		if (err)
508 			return err;
509 	}
510 
511 	for (i = 0; i < client->ncapabilities; i++) {
512 		struct gotd_client_capability *capa;
513 		capa = &client->capabilities[i];
514 		err = send_capability(capa, iev);
515 		if (err)
516 			return err;
517 	}
518 
519 	return NULL;
520 }
521 
522 static const struct got_error *
523 send_info(struct gotd_client *client)
524 {
525 	const struct got_error *err = NULL;
526 	struct gotd_imsg_info info;
527 	uint64_t slot;
528 	struct gotd_repo *repo;
529 
530 	if (client->euid != 0)
531 		return got_error_set_errno(EPERM, "info");
532 
533 	info.pid = gotd.pid;
534 	info.verbosity = gotd.verbosity;
535 	info.nrepos = gotd.nrepos;
536 	info.nclients = client_cnt - 1;
537 
538 	if (gotd_imsg_compose_event(&client->iev, GOTD_IMSG_INFO, PROC_GOTD, -1,
539 	    &info, sizeof(info)) == -1) {
540 		err = got_error_from_errno("imsg compose INFO");
541 		if (err)
542 			return err;
543 	}
544 
545 	TAILQ_FOREACH(repo, &gotd.repos, entry) {
546 		err = send_repo_info(&client->iev, repo);
547 		if (err)
548 			return err;
549 	}
550 
551 	for (slot = 0; slot < nitems(gotd_clients); slot++) {
552 		struct gotd_client *c;
553 		STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
554 			if (c->id == client->id)
555 				continue;
556 			err = send_client_info(&client->iev, c);
557 			if (err)
558 				return err;
559 		}
560 	}
561 
562 	return NULL;
563 }
564 
565 static const struct got_error *
566 stop_gotd(struct gotd_client *client)
567 {
568 
569 	if (client->euid != 0)
570 		return got_error_set_errno(EPERM, "stop");
571 
572 	gotd_shutdown();
573 	/* NOTREACHED */
574 	return NULL;
575 }
576 
577 static struct gotd_repo *
578 find_repo_by_name(const char *repo_name)
579 {
580 	struct gotd_repo *repo;
581 	size_t namelen;
582 
583 	TAILQ_FOREACH(repo, &gotd.repos, entry) {
584 		namelen = strlen(repo->name);
585 		if (strncmp(repo->name, repo_name, namelen) != 0)
586 			continue;
587 		if (repo_name[namelen] == '\0' ||
588 		    strcmp(&repo_name[namelen], ".git") == 0)
589 			return repo;
590 	}
591 
592 	return NULL;
593 }
594 
595 static const struct got_error *
596 start_client_session(struct gotd_client *client, struct imsg *imsg)
597 {
598 	const struct got_error *err;
599 	struct gotd_imsg_list_refs ireq;
600 	struct gotd_repo *repo = NULL;
601 	size_t datalen;
602 
603 	log_debug("list-refs request from uid %d", client->euid);
604 
605 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
606 	if (datalen != sizeof(ireq))
607 		return got_error(GOT_ERR_PRIVSEP_LEN);
608 
609 	memcpy(&ireq, imsg->data, datalen);
610 
611 	if (ireq.client_is_reading) {
612 		err = ensure_client_is_not_writing(client);
613 		if (err)
614 			return err;
615 		repo = find_repo_by_name(ireq.repo_name);
616 		if (repo == NULL)
617 			return got_error(GOT_ERR_NOT_GIT_REPO);
618 		err = start_auth_child(client, GOTD_AUTH_READ, repo,
619 		    gotd.argv0, gotd.confpath, gotd.daemonize,
620 		    gotd.verbosity);
621 		if (err)
622 			return err;
623 	} else {
624 		err = ensure_client_is_not_reading(client);
625 		if (err)
626 			return err;
627 		repo = find_repo_by_name(ireq.repo_name);
628 		if (repo == NULL)
629 			return got_error(GOT_ERR_NOT_GIT_REPO);
630 		err = start_auth_child(client,
631 		    GOTD_AUTH_READ | GOTD_AUTH_WRITE,
632 		    repo, gotd.argv0, gotd.confpath, gotd.daemonize,
633 		    gotd.verbosity);
634 		if (err)
635 			return err;
636 	}
637 
638 	/* Flow continues upon authentication successs/failure or timeout. */
639 	return NULL;
640 }
641 
642 static const struct got_error *
643 forward_want(struct gotd_client *client, struct imsg *imsg)
644 {
645 	struct gotd_imsg_want ireq;
646 	struct gotd_imsg_want iwant;
647 	size_t datalen;
648 
649 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
650 	if (datalen != sizeof(ireq))
651 		return got_error(GOT_ERR_PRIVSEP_LEN);
652 
653 	memcpy(&ireq, imsg->data, datalen);
654 
655 	memset(&iwant, 0, sizeof(iwant));
656 	memcpy(iwant.object_id, ireq.object_id, SHA1_DIGEST_LENGTH);
657 	iwant.client_id = client->id;
658 
659 	if (gotd_imsg_compose_event(&client->repo_read->iev, GOTD_IMSG_WANT,
660 	    PROC_GOTD, -1, &iwant, sizeof(iwant)) == -1)
661 		return got_error_from_errno("imsg compose WANT");
662 
663 	return NULL;
664 }
665 
666 static const struct got_error *
667 forward_ref_update(struct gotd_client *client, struct imsg *imsg)
668 {
669 	const struct got_error *err = NULL;
670 	struct gotd_imsg_ref_update ireq;
671 	struct gotd_imsg_ref_update *iref = NULL;
672 	size_t datalen;
673 
674 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
675 	if (datalen < sizeof(ireq))
676 		return got_error(GOT_ERR_PRIVSEP_LEN);
677 	memcpy(&ireq, imsg->data, sizeof(ireq));
678 	if (datalen != sizeof(ireq) + ireq.name_len)
679 		return got_error(GOT_ERR_PRIVSEP_LEN);
680 
681 	iref = malloc(datalen);
682 	if (iref == NULL)
683 		return got_error_from_errno("malloc");
684 	memcpy(iref, imsg->data, datalen);
685 
686 	iref->client_id = client->id;
687 	if (gotd_imsg_compose_event(&client->repo_write->iev,
688 	    GOTD_IMSG_REF_UPDATE, PROC_GOTD, -1, iref, datalen) == -1)
689 		err = got_error_from_errno("imsg compose REF_UPDATE");
690 	free(iref);
691 	return err;
692 }
693 
694 static const struct got_error *
695 forward_have(struct gotd_client *client, struct imsg *imsg)
696 {
697 	struct gotd_imsg_have ireq;
698 	struct gotd_imsg_have ihave;
699 	size_t datalen;
700 
701 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
702 	if (datalen != sizeof(ireq))
703 		return got_error(GOT_ERR_PRIVSEP_LEN);
704 
705 	memcpy(&ireq, imsg->data, datalen);
706 
707 	memset(&ihave, 0, sizeof(ihave));
708 	memcpy(ihave.object_id, ireq.object_id, SHA1_DIGEST_LENGTH);
709 	ihave.client_id = client->id;
710 
711 	if (gotd_imsg_compose_event(&client->repo_read->iev, GOTD_IMSG_HAVE,
712 	    PROC_GOTD, -1, &ihave, sizeof(ihave)) == -1)
713 		return got_error_from_errno("imsg compose HAVE");
714 
715 	return NULL;
716 }
717 
718 static int
719 client_has_capability(struct gotd_client *client, const char *capastr)
720 {
721 	struct gotd_client_capability *capa;
722 	size_t i;
723 
724 	if (client->ncapabilities == 0)
725 		return 0;
726 
727 	for (i = 0; i < client->ncapabilities; i++) {
728 		capa = &client->capabilities[i];
729 		if (strcmp(capa->key, capastr) == 0)
730 			return 1;
731 	}
732 
733 	return 0;
734 }
735 
736 static const struct got_error *
737 recv_capabilities(struct gotd_client *client, struct imsg *imsg)
738 {
739 	struct gotd_imsg_capabilities icapas;
740 	size_t datalen;
741 
742 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
743 	if (datalen != sizeof(icapas))
744 		return got_error(GOT_ERR_PRIVSEP_LEN);
745 	memcpy(&icapas, imsg->data, sizeof(icapas));
746 
747 	client->ncapa_alloc = icapas.ncapabilities;
748 	client->capabilities = calloc(client->ncapa_alloc,
749 	    sizeof(*client->capabilities));
750 	if (client->capabilities == NULL) {
751 		client->ncapa_alloc = 0;
752 		return got_error_from_errno("calloc");
753 	}
754 
755 	log_debug("expecting %zu capabilities from uid %d",
756 	    client->ncapa_alloc, client->euid);
757 	return NULL;
758 }
759 
760 static const struct got_error *
761 recv_capability(struct gotd_client *client, struct imsg *imsg)
762 {
763 	struct gotd_imsg_capability icapa;
764 	struct gotd_client_capability *capa;
765 	size_t datalen;
766 	char *key, *value = NULL;
767 
768 	if (client->capabilities == NULL ||
769 	    client->ncapabilities >= client->ncapa_alloc) {
770 		return got_error_msg(GOT_ERR_BAD_REQUEST,
771 		    "unexpected capability received");
772 	}
773 
774 	memset(&icapa, 0, sizeof(icapa));
775 
776 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
777 	if (datalen < sizeof(icapa))
778 		return got_error(GOT_ERR_PRIVSEP_LEN);
779 	memcpy(&icapa, imsg->data, sizeof(icapa));
780 
781 	if (datalen != sizeof(icapa) + icapa.key_len + icapa.value_len)
782 		return got_error(GOT_ERR_PRIVSEP_LEN);
783 
784 	key = malloc(icapa.key_len + 1);
785 	if (key == NULL)
786 		return got_error_from_errno("malloc");
787 	if (icapa.value_len > 0) {
788 		value = malloc(icapa.value_len + 1);
789 		if (value == NULL) {
790 			free(key);
791 			return got_error_from_errno("malloc");
792 		}
793 	}
794 
795 	memcpy(key, imsg->data + sizeof(icapa), icapa.key_len);
796 	key[icapa.key_len] = '\0';
797 	if (value) {
798 		memcpy(value, imsg->data + sizeof(icapa) + icapa.key_len,
799 		    icapa.value_len);
800 		value[icapa.value_len] = '\0';
801 	}
802 
803 	capa = &client->capabilities[client->ncapabilities++];
804 	capa->key = key;
805 	capa->value = value;
806 
807 	if (value)
808 		log_debug("uid %d: capability %s=%s", client->euid, key, value);
809 	else
810 		log_debug("uid %d: capability %s", client->euid, key);
811 
812 	return NULL;
813 }
814 
815 static const struct got_error *
816 send_packfile(struct gotd_client *client)
817 {
818 	const struct got_error *err = NULL;
819 	struct gotd_imsg_send_packfile ipack;
820 	struct gotd_imsg_packfile_pipe ipipe;
821 	int pipe[2];
822 
823 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe) == -1)
824 		return got_error_from_errno("socketpair");
825 
826 	memset(&ipack, 0, sizeof(ipack));
827 	memset(&ipipe, 0, sizeof(ipipe));
828 
829 	ipack.client_id = client->id;
830 	if (client_has_capability(client, GOT_CAPA_SIDE_BAND_64K))
831 		ipack.report_progress = 1;
832 
833 	client->delta_cache_fd = got_opentempfd();
834 	if (client->delta_cache_fd == -1)
835 		return got_error_from_errno("got_opentempfd");
836 
837 	if (gotd_imsg_compose_event(&client->repo_read->iev,
838 	    GOTD_IMSG_SEND_PACKFILE, PROC_GOTD, client->delta_cache_fd,
839 	    &ipack, sizeof(ipack)) == -1) {
840 		err = got_error_from_errno("imsg compose SEND_PACKFILE");
841 		close(pipe[0]);
842 		close(pipe[1]);
843 		return err;
844 	}
845 
846 	ipipe.client_id = client->id;
847 
848 	/* Send pack pipe end 0 to repo_read. */
849 	if (gotd_imsg_compose_event(&client->repo_read->iev,
850 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[0],
851 	        &ipipe, sizeof(ipipe)) == -1) {
852 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
853 		close(pipe[1]);
854 		return err;
855 	}
856 
857 	/* Send pack pipe end 1 to gotsh(1) (expects just an fd, no data). */
858 	if (gotd_imsg_compose_event(&client->iev,
859 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[1], NULL, 0) == -1)
860 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
861 
862 	return err;
863 }
864 
865 static const struct got_error *
866 recv_packfile(struct gotd_client *client)
867 {
868 	const struct got_error *err = NULL;
869 	struct gotd_imsg_recv_packfile ipack;
870 	struct gotd_imsg_packfile_pipe ipipe;
871 	struct gotd_imsg_packidx_file ifile;
872 	char *basepath = NULL, *pack_path = NULL, *idx_path = NULL;
873 	int packfd = -1, idxfd = -1;
874 	int pipe[2] = { -1, -1 };
875 
876 	if (client->packfile_path) {
877 		return got_error_fmt(GOT_ERR_PRIVSEP_MSG,
878 		    "uid %d already has a pack file", client->euid);
879 	}
880 
881 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe) == -1)
882 		return got_error_from_errno("socketpair");
883 
884 	memset(&ipipe, 0, sizeof(ipipe));
885 	ipipe.client_id = client->id;
886 
887 	/* Send pack pipe end 0 to repo_write. */
888 	if (gotd_imsg_compose_event(&client->repo_write->iev,
889 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[0],
890 	        &ipipe, sizeof(ipipe)) == -1) {
891 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
892 		pipe[0] = -1;
893 		goto done;
894 	}
895 	pipe[0] = -1;
896 
897 	/* Send pack pipe end 1 to gotsh(1) (expects just an fd, no data). */
898 	if (gotd_imsg_compose_event(&client->iev,
899 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[1], NULL, 0) == -1)
900 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
901 	pipe[1] = -1;
902 
903 	if (asprintf(&basepath, "%s/%s/receiving-from-uid-%d.pack",
904 	    client->repo_write->repo_path, GOT_OBJECTS_PACK_DIR,
905 	    client->euid) == -1) {
906 		err = got_error_from_errno("asprintf");
907 		goto done;
908 	}
909 
910 	err = got_opentemp_named_fd(&pack_path, &packfd, basepath, "");
911 	if (err)
912 		goto done;
913 
914 	free(basepath);
915 	if (asprintf(&basepath, "%s/%s/receiving-from-uid-%d.idx",
916 	    client->repo_write->repo_path, GOT_OBJECTS_PACK_DIR,
917 	    client->euid) == -1) {
918 		err = got_error_from_errno("asprintf");
919 		basepath = NULL;
920 		goto done;
921 	}
922 	err = got_opentemp_named_fd(&idx_path, &idxfd, basepath, "");
923 	if (err)
924 		goto done;
925 
926 	memset(&ifile, 0, sizeof(ifile));
927 	ifile.client_id = client->id;
928 	if (gotd_imsg_compose_event(&client->repo_write->iev,
929 	    GOTD_IMSG_PACKIDX_FILE, PROC_GOTD, idxfd,
930 	    &ifile, sizeof(ifile)) == -1) {
931 		err = got_error_from_errno("imsg compose PACKIDX_FILE");
932 		idxfd = -1;
933 		goto done;
934 	}
935 	idxfd = -1;
936 
937 	memset(&ipack, 0, sizeof(ipack));
938 	ipack.client_id = client->id;
939 	if (client_has_capability(client, GOT_CAPA_REPORT_STATUS))
940 		ipack.report_status = 1;
941 
942 	if (gotd_imsg_compose_event(&client->repo_write->iev,
943 	    GOTD_IMSG_RECV_PACKFILE, PROC_GOTD, packfd,
944 	    &ipack, sizeof(ipack)) == -1) {
945 		err = got_error_from_errno("imsg compose RECV_PACKFILE");
946 		packfd = -1;
947 		goto done;
948 	}
949 	packfd = -1;
950 
951 done:
952 	free(basepath);
953 	if (pipe[0] != -1 && close(pipe[0]) == -1 && err == NULL)
954 		err = got_error_from_errno("close");
955 	if (pipe[1] != -1 && close(pipe[1]) == -1 && err == NULL)
956 		err = got_error_from_errno("close");
957 	if (packfd != -1 && close(packfd) == -1 && err == NULL)
958 		err = got_error_from_errno("close");
959 	if (idxfd != -1 && close(idxfd) == -1 && err == NULL)
960 		err = got_error_from_errno("close");
961 	if (err) {
962 		free(pack_path);
963 		free(idx_path);
964 	} else {
965 		client->packfile_path = pack_path;
966 		client->packidx_path = idx_path;
967 	}
968 	return err;
969 }
970 
971 static void
972 gotd_request(int fd, short events, void *arg)
973 {
974 	struct gotd_imsgev *iev = arg;
975 	struct imsgbuf *ibuf = &iev->ibuf;
976 	struct gotd_client *client = iev->handler_arg;
977 	const struct got_error *err = NULL;
978 	struct imsg imsg;
979 	ssize_t n;
980 
981 	if (events & EV_WRITE) {
982 		while (ibuf->w.queued) {
983 			n = msgbuf_write(&ibuf->w);
984 			if (n == -1 && errno == EPIPE) {
985 				/*
986 				 * The client has closed its socket.
987 				 * This can happen when Git clients are
988 				 * done sending pack file data.
989 				 */
990 				msgbuf_clear(&ibuf->w);
991 				continue;
992 			} else if (n == -1 && errno != EAGAIN) {
993 				err = got_error_from_errno("imsg_flush");
994 				disconnect_on_error(client, err);
995 				return;
996 			}
997 			if (n == 0) {
998 				/* Connection closed. */
999 				err = got_error(GOT_ERR_EOF);
1000 				disconnect_on_error(client, err);
1001 				return;
1002 			}
1003 		}
1004 
1005 		/* Disconnect gotctl(8) now that messages have been sent. */
1006 		if (!client_is_reading(client) && !client_is_writing(client)) {
1007 			disconnect(client);
1008 			return;
1009 		}
1010 	}
1011 
1012 	if ((events & EV_READ) == 0)
1013 		return;
1014 
1015 	memset(&imsg, 0, sizeof(imsg));
1016 
1017 	while (err == NULL) {
1018 		err = gotd_imsg_recv(&imsg, ibuf, 0);
1019 		if (err) {
1020 			if (err->code == GOT_ERR_PRIVSEP_READ)
1021 				err = NULL;
1022 			break;
1023 		}
1024 
1025 		evtimer_del(&client->tmo);
1026 
1027 		switch (imsg.hdr.type) {
1028 		case GOTD_IMSG_INFO:
1029 			err = send_info(client);
1030 			break;
1031 		case GOTD_IMSG_STOP:
1032 			err = stop_gotd(client);
1033 			break;
1034 		case GOTD_IMSG_LIST_REFS:
1035 			if (client->state != GOTD_STATE_EXPECT_LIST_REFS) {
1036 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1037 				    "unexpected list-refs request received");
1038 				break;
1039 			}
1040 			err = start_client_session(client, &imsg);
1041 			if (err)
1042 				break;
1043 			break;
1044 		case GOTD_IMSG_CAPABILITIES:
1045 			if (client->state != GOTD_STATE_EXPECT_CAPABILITIES) {
1046 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1047 				    "unexpected capabilities received");
1048 				break;
1049 			}
1050 			log_debug("receiving capabilities from uid %d",
1051 			    client->euid);
1052 			err = recv_capabilities(client, &imsg);
1053 			break;
1054 		case GOTD_IMSG_CAPABILITY:
1055 			if (client->state != GOTD_STATE_EXPECT_CAPABILITIES) {
1056 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1057 				    "unexpected capability received");
1058 				break;
1059 			}
1060 			err = recv_capability(client, &imsg);
1061 			if (err || client->ncapabilities < client->ncapa_alloc)
1062 				break;
1063 			if (client_is_reading(client)) {
1064 				client->state = GOTD_STATE_EXPECT_WANT;
1065 				log_debug("uid %d: expecting want-lines",
1066 				    client->euid);
1067 			} else if (client_is_writing(client)) {
1068 				client->state = GOTD_STATE_EXPECT_REF_UPDATE;
1069 				log_debug("uid %d: expecting ref-update-lines",
1070 				    client->euid);
1071 			} else
1072 				fatalx("client %d is both reading and writing",
1073 				    client->euid);
1074 			break;
1075 		case GOTD_IMSG_WANT:
1076 			if (client->state != GOTD_STATE_EXPECT_WANT) {
1077 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1078 				    "unexpected want-line received");
1079 				break;
1080 			}
1081 			log_debug("received want-line from uid %d",
1082 			    client->euid);
1083 			err = ensure_client_is_reading(client);
1084 			if (err)
1085 				break;
1086 			err = forward_want(client, &imsg);
1087 			break;
1088 		case GOTD_IMSG_REF_UPDATE:
1089 			if (client->state != GOTD_STATE_EXPECT_REF_UPDATE) {
1090 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1091 				    "unexpected ref-update-line received");
1092 				break;
1093 			}
1094 			log_debug("received ref-update-line from uid %d",
1095 			    client->euid);
1096 			err = ensure_client_is_writing(client);
1097 			if (err)
1098 				break;
1099 			err = forward_ref_update(client, &imsg);
1100 			if (err)
1101 				break;
1102 			client->state = GOTD_STATE_EXPECT_MORE_REF_UPDATES;
1103 			break;
1104 		case GOTD_IMSG_HAVE:
1105 			if (client->state != GOTD_STATE_EXPECT_HAVE) {
1106 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1107 				    "unexpected have-line received");
1108 				break;
1109 			}
1110 			log_debug("received have-line from uid %d",
1111 			    client->euid);
1112 			err = ensure_client_is_reading(client);
1113 			if (err)
1114 				break;
1115 			err = forward_have(client, &imsg);
1116 			if (err)
1117 				break;
1118 			break;
1119 		case GOTD_IMSG_FLUSH:
1120 			if (client->state == GOTD_STATE_EXPECT_WANT ||
1121 			    client->state == GOTD_STATE_EXPECT_HAVE) {
1122 				err = ensure_client_is_reading(client);
1123 				if (err)
1124 					break;
1125 			} else if (client->state ==
1126 			    GOTD_STATE_EXPECT_MORE_REF_UPDATES) {
1127 				err = ensure_client_is_writing(client);
1128 				if (err)
1129 					break;
1130 			} else {
1131 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1132 				    "unexpected flush-pkt received");
1133 				break;
1134 			}
1135 			log_debug("received flush-pkt from uid %d",
1136 			    client->euid);
1137 			if (client->state == GOTD_STATE_EXPECT_WANT) {
1138 				client->state = GOTD_STATE_EXPECT_HAVE;
1139 				log_debug("uid %d: expecting have-lines",
1140 				    client->euid);
1141 			} else if (client->state == GOTD_STATE_EXPECT_HAVE) {
1142 				client->state = GOTD_STATE_EXPECT_DONE;
1143 				log_debug("uid %d: expecting 'done'",
1144 				    client->euid);
1145 			} else if (client->state ==
1146 			    GOTD_STATE_EXPECT_MORE_REF_UPDATES) {
1147 				client->state = GOTD_STATE_EXPECT_PACKFILE;
1148 				log_debug("uid %d: expecting packfile",
1149 				    client->euid);
1150 				err = recv_packfile(client);
1151 			} else {
1152 				/* should not happen, see above */
1153 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1154 				    "unexpected client state");
1155 				break;
1156 			}
1157 			break;
1158 		case GOTD_IMSG_DONE:
1159 			if (client->state != GOTD_STATE_EXPECT_HAVE &&
1160 			    client->state != GOTD_STATE_EXPECT_DONE) {
1161 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1162 				    "unexpected flush-pkt received");
1163 				break;
1164 			}
1165 			log_debug("received 'done' from uid %d", client->euid);
1166 			err = ensure_client_is_reading(client);
1167 			if (err)
1168 				break;
1169 			client->state = GOTD_STATE_DONE;
1170 			err = send_packfile(client);
1171 			break;
1172 		default:
1173 			err = got_error(GOT_ERR_PRIVSEP_MSG);
1174 			break;
1175 		}
1176 
1177 		imsg_free(&imsg);
1178 	}
1179 
1180 	if (err) {
1181 		if (err->code != GOT_ERR_EOF ||
1182 		    client->state != GOTD_STATE_EXPECT_PACKFILE)
1183 			disconnect_on_error(client, err);
1184 	} else {
1185 		gotd_imsg_event_add(&client->iev);
1186 		if (client->state == GOTD_STATE_EXPECT_LIST_REFS)
1187 			evtimer_add(&client->tmo, &auth_timeout);
1188 		else
1189 			evtimer_add(&client->tmo, &gotd.request_timeout);
1190 	}
1191 }
1192 
1193 static void
1194 gotd_request_timeout(int fd, short events, void *arg)
1195 {
1196 	struct gotd_client *client = arg;
1197 
1198 	log_debug("disconnecting uid %d due to timeout", client->euid);
1199 	disconnect(client);
1200 }
1201 
1202 static const struct got_error *
1203 recv_connect(uint32_t *client_id, struct imsg *imsg)
1204 {
1205 	const struct got_error *err = NULL;
1206 	struct gotd_imsg_connect iconnect;
1207 	size_t datalen;
1208 	int s = -1;
1209 	struct gotd_client *client = NULL;
1210 
1211 	*client_id = 0;
1212 
1213 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1214 	if (datalen != sizeof(iconnect))
1215 		return got_error(GOT_ERR_PRIVSEP_LEN);
1216 	memcpy(&iconnect, imsg->data, sizeof(iconnect));
1217 
1218 	s = imsg->fd;
1219 	if (s == -1) {
1220 		err = got_error(GOT_ERR_PRIVSEP_NO_FD);
1221 		goto done;
1222 	}
1223 
1224 	if (find_client(iconnect.client_id)) {
1225 		err = got_error_msg(GOT_ERR_CLIENT_ID, "duplicate client ID");
1226 		goto done;
1227 	}
1228 
1229 	client = calloc(1, sizeof(*client));
1230 	if (client == NULL) {
1231 		err = got_error_from_errno("calloc");
1232 		goto done;
1233 	}
1234 
1235 	*client_id = iconnect.client_id;
1236 
1237 	client->state = GOTD_STATE_EXPECT_LIST_REFS;
1238 	client->id = iconnect.client_id;
1239 	client->fd = s;
1240 	s = -1;
1241 	client->delta_cache_fd = -1;
1242 	/* The auth process will verify UID/GID for us. */
1243 	client->euid = iconnect.euid;
1244 	client->egid = iconnect.egid;
1245 	client->nref_updates = -1;
1246 
1247 	imsg_init(&client->iev.ibuf, client->fd);
1248 	client->iev.handler = gotd_request;
1249 	client->iev.events = EV_READ;
1250 	client->iev.handler_arg = client;
1251 
1252 	event_set(&client->iev.ev, client->fd, EV_READ, gotd_request,
1253 	    &client->iev);
1254 	gotd_imsg_event_add(&client->iev);
1255 
1256 	evtimer_set(&client->tmo, gotd_request_timeout, client);
1257 
1258 	add_client(client);
1259 	log_debug("%s: new client uid %d connected on fd %d", __func__,
1260 	    client->euid, client->fd);
1261 done:
1262 	if (err) {
1263 		struct gotd_child_proc *listen_proc = &gotd.listen_proc;
1264 		struct gotd_imsg_disconnect idisconnect;
1265 
1266 		idisconnect.client_id = client->id;
1267 		if (gotd_imsg_compose_event(&listen_proc->iev,
1268 		    GOTD_IMSG_DISCONNECT, PROC_GOTD, -1,
1269 		    &idisconnect, sizeof(idisconnect)) == -1)
1270 			log_warn("imsg compose DISCONNECT");
1271 
1272 		if (s != -1)
1273 			close(s);
1274 	}
1275 
1276 	return err;
1277 }
1278 
1279 static const char *gotd_proc_names[PROC_MAX] = {
1280 	"parent",
1281 	"listen",
1282 	"auth",
1283 	"repo_read",
1284 	"repo_write"
1285 };
1286 
1287 static void
1288 kill_proc(struct gotd_child_proc *proc, int fatal)
1289 {
1290 	if (fatal) {
1291 		log_warnx("sending SIGKILL to PID %d", proc->pid);
1292 		kill(proc->pid, SIGKILL);
1293 	} else
1294 		kill(proc->pid, SIGTERM);
1295 }
1296 
1297 static void
1298 gotd_shutdown(void)
1299 {
1300 	struct gotd_child_proc *proc;
1301 	uint64_t slot;
1302 
1303 	for (slot = 0; slot < nitems(gotd_clients); slot++) {
1304 		struct gotd_client *c, *tmp;
1305 
1306 		STAILQ_FOREACH_SAFE(c, &gotd_clients[slot], entry, tmp)
1307 			disconnect(c);
1308 	}
1309 
1310 	proc = &gotd.listen_proc;
1311 	msgbuf_clear(&proc->iev.ibuf.w);
1312 	close(proc->iev.ibuf.fd);
1313 	kill_proc(proc, 0);
1314 	wait_for_child(proc->pid);
1315 
1316 	log_info("terminating");
1317 	exit(0);
1318 }
1319 
1320 void
1321 gotd_sighdlr(int sig, short event, void *arg)
1322 {
1323 	/*
1324 	 * Normal signal handler rules don't apply because libevent
1325 	 * decouples for us.
1326 	 */
1327 
1328 	switch (sig) {
1329 	case SIGHUP:
1330 		log_info("%s: ignoring SIGHUP", __func__);
1331 		break;
1332 	case SIGUSR1:
1333 		log_info("%s: ignoring SIGUSR1", __func__);
1334 		break;
1335 	case SIGTERM:
1336 	case SIGINT:
1337 		gotd_shutdown();
1338 		log_warnx("gotd terminating");
1339 		exit(0);
1340 		break;
1341 	default:
1342 		fatalx("unexpected signal");
1343 	}
1344 }
1345 
1346 static const struct got_error *
1347 ensure_proc_is_reading(struct gotd_client *client,
1348     struct gotd_child_proc *proc)
1349 {
1350 	if (!client_is_reading(client)) {
1351 		kill_proc(proc, 1);
1352 		return got_error_fmt(GOT_ERR_BAD_PACKET,
1353 		    "PID %d handled a read-request for uid %d but this "
1354 		    "user is not reading from a repository", proc->pid,
1355 		    client->euid);
1356 	}
1357 
1358 	return NULL;
1359 }
1360 
1361 static const struct got_error *
1362 ensure_proc_is_writing(struct gotd_client *client,
1363     struct gotd_child_proc *proc)
1364 {
1365 	if (!client_is_writing(client)) {
1366 		kill_proc(proc, 1);
1367 		return got_error_fmt(GOT_ERR_BAD_PACKET,
1368 		    "PID %d handled a write-request for uid %d but this "
1369 		    "user is not writing to a repository", proc->pid,
1370 		    client->euid);
1371 	}
1372 
1373 	return NULL;
1374 }
1375 
1376 static int
1377 verify_imsg_src(struct gotd_client *client, struct gotd_child_proc *proc,
1378     struct imsg *imsg)
1379 {
1380 	const struct got_error *err;
1381 	struct gotd_child_proc *client_proc;
1382 	int ret = 0;
1383 
1384 	if (proc->type == PROC_REPO_READ || proc->type == PROC_REPO_WRITE) {
1385 		client_proc = get_client_proc(client);
1386 		if (client_proc == NULL)
1387 			fatalx("no process found for uid %d", client->euid);
1388 		if (proc->pid != client_proc->pid) {
1389 			kill_proc(proc, 1);
1390 			log_warnx("received message from PID %d for uid %d, "
1391 			    "while PID %d is the process serving this user",
1392 			    proc->pid, client->euid, client_proc->pid);
1393 			return 0;
1394 		}
1395 	}
1396 
1397 	switch (imsg->hdr.type) {
1398 	case GOTD_IMSG_ERROR:
1399 		ret = 1;
1400 		break;
1401 	case GOTD_IMSG_CONNECT:
1402 		if (proc->type != PROC_LISTEN) {
1403 			err = got_error_fmt(GOT_ERR_BAD_PACKET,
1404 			    "new connection for uid %d from PID %d "
1405 			    "which is not the listen process",
1406 			    proc->pid, client->euid);
1407 		} else
1408 			ret = 1;
1409 		break;
1410 	case GOTD_IMSG_ACCESS_GRANTED:
1411 		if (proc->type != PROC_AUTH) {
1412 			err = got_error_fmt(GOT_ERR_BAD_PACKET,
1413 			    "authentication of uid %d from PID %d "
1414 			    "which is not the auth process",
1415 			    proc->pid, client->euid);
1416 		} else
1417 			ret = 1;
1418 		break;
1419 	case GOTD_IMSG_REPO_CHILD_READY:
1420 		if (proc->type != PROC_REPO_READ &&
1421 		    proc->type != PROC_REPO_WRITE) {
1422 			err = got_error_fmt(GOT_ERR_BAD_PACKET,
1423 			    "unexpected \"ready\" signal from PID %d",
1424 			    proc->pid);
1425 		} else
1426 			ret = 1;
1427 		break;
1428 	case GOTD_IMSG_PACKFILE_DONE:
1429 		err = ensure_proc_is_reading(client, proc);
1430 		if (err)
1431 			log_warnx("uid %d: %s", client->euid, err->msg);
1432 		else
1433 			ret = 1;
1434 		break;
1435 	case GOTD_IMSG_PACKFILE_INSTALL:
1436 	case GOTD_IMSG_REF_UPDATES_START:
1437 	case GOTD_IMSG_REF_UPDATE:
1438 		err = ensure_proc_is_writing(client, proc);
1439 		if (err)
1440 			log_warnx("uid %d: %s", client->euid, err->msg);
1441 		else
1442 			ret = 1;
1443 		break;
1444 	default:
1445 		log_debug("%s: unexpected imsg %d", __func__, imsg->hdr.type);
1446 		break;
1447 	}
1448 
1449 	return ret;
1450 }
1451 
1452 static const struct got_error *
1453 list_refs_request(struct gotd_client *client, struct gotd_imsgev *iev)
1454 {
1455 	static const struct got_error *err;
1456 	struct gotd_imsg_list_refs_internal ilref;
1457 	int fd;
1458 
1459 	memset(&ilref, 0, sizeof(ilref));
1460 	ilref.client_id = client->id;
1461 
1462 	fd = dup(client->fd);
1463 	if (fd == -1)
1464 		return got_error_from_errno("dup");
1465 
1466 	if (gotd_imsg_compose_event(iev, GOTD_IMSG_LIST_REFS_INTERNAL,
1467 	    PROC_GOTD, fd, &ilref, sizeof(ilref)) == -1) {
1468 		err = got_error_from_errno("imsg compose WANT");
1469 		close(fd);
1470 		return err;
1471 	}
1472 
1473 	client->state = GOTD_STATE_EXPECT_CAPABILITIES;
1474 	log_debug("uid %d: expecting capabilities", client->euid);
1475 	return NULL;
1476 }
1477 
1478 static const struct got_error *
1479 recv_packfile_done(uint32_t *client_id, struct imsg *imsg)
1480 {
1481 	struct gotd_imsg_packfile_done idone;
1482 	size_t datalen;
1483 
1484 	log_debug("packfile-done received");
1485 
1486 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1487 	if (datalen != sizeof(idone))
1488 		return got_error(GOT_ERR_PRIVSEP_LEN);
1489 	memcpy(&idone, imsg->data, sizeof(idone));
1490 
1491 	*client_id = idone.client_id;
1492 	return NULL;
1493 }
1494 
1495 static const struct got_error *
1496 recv_packfile_install(uint32_t *client_id, struct imsg *imsg)
1497 {
1498 	struct gotd_imsg_packfile_install inst;
1499 	size_t datalen;
1500 
1501 	log_debug("packfile-install received");
1502 
1503 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1504 	if (datalen != sizeof(inst))
1505 		return got_error(GOT_ERR_PRIVSEP_LEN);
1506 	memcpy(&inst, imsg->data, sizeof(inst));
1507 
1508 	*client_id = inst.client_id;
1509 	return NULL;
1510 }
1511 
1512 static const struct got_error *
1513 recv_ref_updates_start(uint32_t *client_id, struct imsg *imsg)
1514 {
1515 	struct gotd_imsg_ref_updates_start istart;
1516 	size_t datalen;
1517 
1518 	log_debug("ref-updates-start received");
1519 
1520 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1521 	if (datalen != sizeof(istart))
1522 		return got_error(GOT_ERR_PRIVSEP_LEN);
1523 	memcpy(&istart, imsg->data, sizeof(istart));
1524 
1525 	*client_id = istart.client_id;
1526 	return NULL;
1527 }
1528 
1529 static const struct got_error *
1530 recv_ref_update(uint32_t *client_id, struct imsg *imsg)
1531 {
1532 	struct gotd_imsg_ref_update iref;
1533 	size_t datalen;
1534 
1535 	log_debug("ref-update received");
1536 
1537 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1538 	if (datalen < sizeof(iref))
1539 		return got_error(GOT_ERR_PRIVSEP_LEN);
1540 	memcpy(&iref, imsg->data, sizeof(iref));
1541 
1542 	*client_id = iref.client_id;
1543 	return NULL;
1544 }
1545 
1546 static const struct got_error *
1547 send_ref_update_ok(struct gotd_client *client,
1548     struct gotd_imsg_ref_update *iref, const char *refname)
1549 {
1550 	struct gotd_imsg_ref_update_ok iok;
1551 	struct ibuf *wbuf;
1552 	size_t len;
1553 
1554 	memset(&iok, 0, sizeof(iok));
1555 	iok.client_id = client->id;
1556 	memcpy(iok.old_id, iref->old_id, SHA1_DIGEST_LENGTH);
1557 	memcpy(iok.new_id, iref->new_id, SHA1_DIGEST_LENGTH);
1558 	iok.name_len = strlen(refname);
1559 
1560 	len = sizeof(iok) + iok.name_len;
1561 	wbuf = imsg_create(&client->iev.ibuf, GOTD_IMSG_REF_UPDATE_OK,
1562 	    PROC_GOTD, gotd.pid, len);
1563 	if (wbuf == NULL)
1564 		return got_error_from_errno("imsg_create REF_UPDATE_OK");
1565 
1566 	if (imsg_add(wbuf, &iok, sizeof(iok)) == -1)
1567 		return got_error_from_errno("imsg_add REF_UPDATE_OK");
1568 	if (imsg_add(wbuf, refname, iok.name_len) == -1)
1569 		return got_error_from_errno("imsg_add REF_UPDATE_OK");
1570 
1571 	wbuf->fd = -1;
1572 	imsg_close(&client->iev.ibuf, wbuf);
1573 	gotd_imsg_event_add(&client->iev);
1574 	return NULL;
1575 }
1576 
1577 static void
1578 send_refs_updated(struct gotd_client *client)
1579 {
1580 	if (gotd_imsg_compose_event(&client->iev,
1581 	    GOTD_IMSG_REFS_UPDATED, PROC_GOTD, -1, NULL, 0) == -1)
1582 		log_warn("imsg compose REFS_UPDATED");
1583 }
1584 
1585 static const struct got_error *
1586 send_ref_update_ng(struct gotd_client *client,
1587     struct gotd_imsg_ref_update *iref, const char *refname,
1588     const char *reason)
1589 {
1590 	const struct got_error *ng_err;
1591 	struct gotd_imsg_ref_update_ng ing;
1592 	struct ibuf *wbuf;
1593 	size_t len;
1594 
1595 	memset(&ing, 0, sizeof(ing));
1596 	ing.client_id = client->id;
1597 	memcpy(ing.old_id, iref->old_id, SHA1_DIGEST_LENGTH);
1598 	memcpy(ing.new_id, iref->new_id, SHA1_DIGEST_LENGTH);
1599 	ing.name_len = strlen(refname);
1600 
1601 	ng_err = got_error_fmt(GOT_ERR_REF_BUSY, "%s", reason);
1602 	ing.reason_len = strlen(ng_err->msg);
1603 
1604 	len = sizeof(ing) + ing.name_len + ing.reason_len;
1605 	wbuf = imsg_create(&client->iev.ibuf, GOTD_IMSG_REF_UPDATE_NG,
1606 	    PROC_GOTD, gotd.pid, len);
1607 	if (wbuf == NULL)
1608 		return got_error_from_errno("imsg_create REF_UPDATE_NG");
1609 
1610 	if (imsg_add(wbuf, &ing, sizeof(ing)) == -1)
1611 		return got_error_from_errno("imsg_add REF_UPDATE_NG");
1612 	if (imsg_add(wbuf, refname, ing.name_len) == -1)
1613 		return got_error_from_errno("imsg_add REF_UPDATE_NG");
1614 	if (imsg_add(wbuf, ng_err->msg, ing.reason_len) == -1)
1615 		return got_error_from_errno("imsg_add REF_UPDATE_NG");
1616 
1617 	wbuf->fd = -1;
1618 	imsg_close(&client->iev.ibuf, wbuf);
1619 	gotd_imsg_event_add(&client->iev);
1620 	return NULL;
1621 }
1622 
1623 static const struct got_error *
1624 install_pack(struct gotd_client *client, const char *repo_path,
1625     struct imsg *imsg)
1626 {
1627 	const struct got_error *err = NULL;
1628 	struct gotd_imsg_packfile_install inst;
1629 	char hex[SHA1_DIGEST_STRING_LENGTH];
1630 	size_t datalen;
1631 	char *packfile_path = NULL, *packidx_path = NULL;
1632 
1633 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1634 	if (datalen != sizeof(inst))
1635 		return got_error(GOT_ERR_PRIVSEP_LEN);
1636 	memcpy(&inst, imsg->data, sizeof(inst));
1637 
1638 	if (client->packfile_path == NULL)
1639 		return got_error_msg(GOT_ERR_BAD_REQUEST,
1640 		    "client has no pack file");
1641 	if (client->packidx_path == NULL)
1642 		return got_error_msg(GOT_ERR_BAD_REQUEST,
1643 		    "client has no pack file index");
1644 
1645 	if (got_sha1_digest_to_str(inst.pack_sha1, hex, sizeof(hex)) == NULL)
1646 		return got_error_msg(GOT_ERR_NO_SPACE,
1647 		    "could not convert pack file SHA1 to hex");
1648 
1649 	if (asprintf(&packfile_path, "/%s/%s/pack-%s.pack",
1650 	    repo_path, GOT_OBJECTS_PACK_DIR, hex) == -1) {
1651 		err = got_error_from_errno("asprintf");
1652 		goto done;
1653 	}
1654 
1655 	if (asprintf(&packidx_path, "/%s/%s/pack-%s.idx",
1656 	    repo_path, GOT_OBJECTS_PACK_DIR, hex) == -1) {
1657 		err = got_error_from_errno("asprintf");
1658 		goto done;
1659 	}
1660 
1661 	if (rename(client->packfile_path, packfile_path) == -1) {
1662 		err = got_error_from_errno3("rename", client->packfile_path,
1663 		    packfile_path);
1664 		goto done;
1665 	}
1666 
1667 	free(client->packfile_path);
1668 	client->packfile_path = NULL;
1669 
1670 	if (rename(client->packidx_path, packidx_path) == -1) {
1671 		err = got_error_from_errno3("rename", client->packidx_path,
1672 		    packidx_path);
1673 		goto done;
1674 	}
1675 
1676 	free(client->packidx_path);
1677 	client->packidx_path = NULL;
1678 done:
1679 	free(packfile_path);
1680 	free(packidx_path);
1681 	return err;
1682 }
1683 
1684 static const struct got_error *
1685 begin_ref_updates(struct gotd_client *client, struct imsg *imsg)
1686 {
1687 	struct gotd_imsg_ref_updates_start istart;
1688 	size_t datalen;
1689 
1690 	if (client->nref_updates != -1)
1691 		return got_error(GOT_ERR_PRIVSEP_MSG);
1692 
1693 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1694 	if (datalen != sizeof(istart))
1695 		return got_error(GOT_ERR_PRIVSEP_LEN);
1696 	memcpy(&istart, imsg->data, sizeof(istart));
1697 
1698 	if (istart.nref_updates <= 0)
1699 		return got_error(GOT_ERR_PRIVSEP_MSG);
1700 
1701 	client->nref_updates = istart.nref_updates;
1702 	return NULL;
1703 }
1704 
1705 static const struct got_error *
1706 update_ref(struct gotd_client *client, const char *repo_path,
1707     struct imsg *imsg)
1708 {
1709 	const struct got_error *err = NULL;
1710 	struct got_repository *repo = NULL;
1711 	struct got_reference *ref = NULL;
1712 	struct gotd_imsg_ref_update iref;
1713 	struct got_object_id old_id, new_id;
1714 	struct got_object_id *id = NULL;
1715 	struct got_object *obj = NULL;
1716 	char *refname = NULL;
1717 	size_t datalen;
1718 	int locked = 0;
1719 
1720 	log_debug("update-ref from uid %d", client->euid);
1721 
1722 	if (client->nref_updates <= 0)
1723 		return got_error(GOT_ERR_PRIVSEP_MSG);
1724 
1725 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1726 	if (datalen < sizeof(iref))
1727 		return got_error(GOT_ERR_PRIVSEP_LEN);
1728 	memcpy(&iref, imsg->data, sizeof(iref));
1729 	if (datalen != sizeof(iref) + iref.name_len)
1730 		return got_error(GOT_ERR_PRIVSEP_LEN);
1731 	refname = malloc(iref.name_len + 1);
1732 	if (refname == NULL)
1733 		return got_error_from_errno("malloc");
1734 	memcpy(refname, imsg->data + sizeof(iref), iref.name_len);
1735 	refname[iref.name_len] = '\0';
1736 
1737 	log_debug("updating ref %s for uid %d", refname, client->euid);
1738 
1739 	err = got_repo_open(&repo, repo_path, NULL, NULL);
1740 	if (err)
1741 		goto done;
1742 
1743 	memcpy(old_id.sha1, iref.old_id, SHA1_DIGEST_LENGTH);
1744 	memcpy(new_id.sha1, iref.new_id, SHA1_DIGEST_LENGTH);
1745 	err = got_object_open(&obj, repo, &new_id);
1746 	if (err)
1747 		goto done;
1748 
1749 	if (iref.ref_is_new) {
1750 		err = got_ref_open(&ref, repo, refname, 0);
1751 		if (err) {
1752 			if (err->code != GOT_ERR_NOT_REF)
1753 				goto done;
1754 			err = got_ref_alloc(&ref, refname, &new_id);
1755 			if (err)
1756 				goto done;
1757 			err = got_ref_write(ref, repo); /* will lock/unlock */
1758 			if (err)
1759 				goto done;
1760 		} else {
1761 			err = got_error_fmt(GOT_ERR_REF_BUSY,
1762 			    "%s has been created by someone else "
1763 			    "while transaction was in progress",
1764 			    got_ref_get_name(ref));
1765 			goto done;
1766 		}
1767 	} else {
1768 		err = got_ref_open(&ref, repo, refname, 1 /* lock */);
1769 		if (err)
1770 			goto done;
1771 		locked = 1;
1772 
1773 		err = got_ref_resolve(&id, repo, ref);
1774 		if (err)
1775 			goto done;
1776 
1777 		if (got_object_id_cmp(id, &old_id) != 0) {
1778 			err = got_error_fmt(GOT_ERR_REF_BUSY,
1779 			    "%s has been modified by someone else "
1780 			    "while transaction was in progress",
1781 			    got_ref_get_name(ref));
1782 			goto done;
1783 		}
1784 
1785 		err = got_ref_change_ref(ref, &new_id);
1786 		if (err)
1787 			goto done;
1788 
1789 		err = got_ref_write(ref, repo);
1790 		if (err)
1791 			goto done;
1792 
1793 		free(id);
1794 		id = NULL;
1795 	}
1796 done:
1797 	if (err) {
1798 		if (err->code == GOT_ERR_LOCKFILE_TIMEOUT) {
1799 			err = got_error_fmt(GOT_ERR_LOCKFILE_TIMEOUT,
1800 			    "could not acquire exclusive file lock for %s",
1801 			    refname);
1802 		}
1803 		send_ref_update_ng(client, &iref, refname, err->msg);
1804 	} else
1805 		send_ref_update_ok(client, &iref, refname);
1806 
1807 	if (client->nref_updates > 0) {
1808 		client->nref_updates--;
1809 		if (client->nref_updates == 0)
1810 			send_refs_updated(client);
1811 
1812 	}
1813 	if (locked) {
1814 		const struct got_error *unlock_err;
1815 		unlock_err = got_ref_unlock(ref);
1816 		if (unlock_err && err == NULL)
1817 			err = unlock_err;
1818 	}
1819 	if (ref)
1820 		got_ref_close(ref);
1821 	if (obj)
1822 		got_object_close(obj);
1823 	if (repo)
1824 		got_repo_close(repo);
1825 	free(refname);
1826 	free(id);
1827 	return err;
1828 }
1829 
1830 static void
1831 gotd_dispatch_listener(int fd, short event, void *arg)
1832 {
1833 	struct gotd_imsgev *iev = arg;
1834 	struct imsgbuf *ibuf = &iev->ibuf;
1835 	struct gotd_child_proc *proc = &gotd.listen_proc;
1836 	ssize_t n;
1837 	int shut = 0;
1838 	struct imsg imsg;
1839 
1840 	if (proc->iev.ibuf.fd != fd)
1841 		fatalx("%s: unexpected fd %d", __func__, fd);
1842 
1843 	if (event & EV_READ) {
1844 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1845 			fatal("imsg_read error");
1846 		if (n == 0) {
1847 			/* Connection closed. */
1848 			shut = 1;
1849 			goto done;
1850 		}
1851 	}
1852 
1853 	if (event & EV_WRITE) {
1854 		n = msgbuf_write(&ibuf->w);
1855 		if (n == -1 && errno != EAGAIN)
1856 			fatal("msgbuf_write");
1857 		if (n == 0) {
1858 			/* Connection closed. */
1859 			shut = 1;
1860 			goto done;
1861 		}
1862 	}
1863 
1864 	for (;;) {
1865 		const struct got_error *err = NULL;
1866 		struct gotd_client *client = NULL;
1867 		uint32_t client_id = 0;
1868 		int do_disconnect = 0;
1869 
1870 		if ((n = imsg_get(ibuf, &imsg)) == -1)
1871 			fatal("%s: imsg_get error", __func__);
1872 		if (n == 0)	/* No more messages. */
1873 			break;
1874 
1875 		switch (imsg.hdr.type) {
1876 		case GOTD_IMSG_ERROR:
1877 			do_disconnect = 1;
1878 			err = gotd_imsg_recv_error(&client_id, &imsg);
1879 			break;
1880 		case GOTD_IMSG_CONNECT:
1881 			err = recv_connect(&client_id, &imsg);
1882 			break;
1883 		default:
1884 			log_debug("unexpected imsg %d", imsg.hdr.type);
1885 			break;
1886 		}
1887 
1888 		client = find_client(client_id);
1889 		if (client == NULL) {
1890 			log_warnx("%s: client not found", __func__);
1891 			imsg_free(&imsg);
1892 			continue;
1893 		}
1894 
1895 		if (err)
1896 			log_warnx("uid %d: %s", client->euid, err->msg);
1897 
1898 		if (do_disconnect) {
1899 			if (err)
1900 				disconnect_on_error(client, err);
1901 			else
1902 				disconnect(client);
1903 		}
1904 
1905 		imsg_free(&imsg);
1906 	}
1907 done:
1908 	if (!shut) {
1909 		gotd_imsg_event_add(iev);
1910 	} else {
1911 		/* This pipe is dead. Remove its event handler */
1912 		event_del(&iev->ev);
1913 		event_loopexit(NULL);
1914 	}
1915 }
1916 
1917 static void
1918 gotd_dispatch_auth_child(int fd, short event, void *arg)
1919 {
1920 	const struct got_error *err = NULL;
1921 	struct gotd_imsgev *iev = arg;
1922 	struct imsgbuf *ibuf = &iev->ibuf;
1923 	struct gotd_client *client;
1924 	struct gotd_repo *repo = NULL;
1925 	ssize_t n;
1926 	int shut = 0;
1927 	struct imsg imsg;
1928 	uint32_t client_id = 0;
1929 	int do_disconnect = 0;
1930 	enum gotd_procid proc_type;
1931 
1932 	client = find_client_by_proc_fd(fd);
1933 	if (client == NULL)
1934 		fatalx("cannot find client for fd %d", fd);
1935 
1936 	if (client->auth == NULL)
1937 		fatalx("cannot find auth child process for fd %d", fd);
1938 
1939 	if (event & EV_READ) {
1940 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1941 			fatal("imsg_read error");
1942 		if (n == 0) {
1943 			/* Connection closed. */
1944 			shut = 1;
1945 			goto done;
1946 		}
1947 	}
1948 
1949 	if (event & EV_WRITE) {
1950 		n = msgbuf_write(&ibuf->w);
1951 		if (n == -1 && errno != EAGAIN)
1952 			fatal("msgbuf_write");
1953 		if (n == 0) {
1954 			/* Connection closed. */
1955 			shut = 1;
1956 		}
1957 		goto done;
1958 	}
1959 
1960 	if (client->auth->iev.ibuf.fd != fd)
1961 		fatalx("%s: unexpected fd %d", __func__, fd);
1962 
1963 	if ((n = imsg_get(ibuf, &imsg)) == -1)
1964 		fatal("%s: imsg_get error", __func__);
1965 	if (n == 0)	/* No more messages. */
1966 		return;
1967 
1968 	evtimer_del(&client->tmo);
1969 
1970 	switch (imsg.hdr.type) {
1971 	case GOTD_IMSG_ERROR:
1972 		do_disconnect = 1;
1973 		err = gotd_imsg_recv_error(&client_id, &imsg);
1974 		break;
1975 	case GOTD_IMSG_ACCESS_GRANTED:
1976 		break;
1977 	default:
1978 		do_disconnect = 1;
1979 		log_debug("unexpected imsg %d", imsg.hdr.type);
1980 		break;
1981 	}
1982 
1983 	if (!verify_imsg_src(client, client->auth, &imsg)) {
1984 		do_disconnect = 1;
1985 		log_debug("dropping imsg type %d from PID %d",
1986 		    imsg.hdr.type, client->auth->pid);
1987 	}
1988 	imsg_free(&imsg);
1989 
1990 	if (do_disconnect) {
1991 		if (err)
1992 			disconnect_on_error(client, err);
1993 		else
1994 			disconnect(client);
1995 		goto done;
1996 	}
1997 
1998 	repo = find_repo_by_name(client->auth->repo_name);
1999 	if (repo == NULL) {
2000 		err = got_error(GOT_ERR_NOT_GIT_REPO);
2001 		goto done;
2002 	}
2003 	kill_auth_proc(client);
2004 
2005 	log_info("authenticated uid %d for repository %s\n",
2006 	    client->euid, repo->name);
2007 
2008 	if (client->required_auth & GOTD_AUTH_WRITE)
2009 		proc_type = PROC_REPO_WRITE;
2010 	else
2011 		proc_type = PROC_REPO_READ;
2012 
2013 	err = start_repo_child(client, proc_type, repo, gotd.argv0,
2014 	    gotd.confpath, gotd.daemonize, gotd.verbosity);
2015 done:
2016 	if (err)
2017 		log_warnx("uid %d: %s", client->euid, err->msg);
2018 
2019 	/* We might have killed the auth process by now. */
2020 	if (client->auth != NULL) {
2021 		if (!shut) {
2022 			gotd_imsg_event_add(iev);
2023 		} else {
2024 			/* This pipe is dead. Remove its event handler */
2025 			event_del(&iev->ev);
2026 		}
2027 	}
2028 }
2029 
2030 static void
2031 gotd_dispatch_repo_child(int fd, short event, void *arg)
2032 {
2033 	struct gotd_imsgev *iev = arg;
2034 	struct imsgbuf *ibuf = &iev->ibuf;
2035 	struct gotd_child_proc *proc = NULL;
2036 	struct gotd_client *client = NULL;
2037 	ssize_t n;
2038 	int shut = 0;
2039 	struct imsg imsg;
2040 
2041 	if (event & EV_READ) {
2042 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
2043 			fatal("imsg_read error");
2044 		if (n == 0) {
2045 			/* Connection closed. */
2046 			shut = 1;
2047 			goto done;
2048 		}
2049 	}
2050 
2051 	if (event & EV_WRITE) {
2052 		n = msgbuf_write(&ibuf->w);
2053 		if (n == -1 && errno != EAGAIN)
2054 			fatal("msgbuf_write");
2055 		if (n == 0) {
2056 			/* Connection closed. */
2057 			shut = 1;
2058 			goto done;
2059 		}
2060 	}
2061 
2062 	client = find_client_by_proc_fd(fd);
2063 	if (client == NULL)
2064 		fatalx("cannot find client for fd %d", fd);
2065 
2066 	proc = get_client_proc(client);
2067 	if (proc == NULL)
2068 		fatalx("cannot find child process for fd %d", fd);
2069 
2070 	for (;;) {
2071 		const struct got_error *err = NULL;
2072 		uint32_t client_id = 0;
2073 		int do_disconnect = 0;
2074 		int do_list_refs = 0, do_ref_updates = 0, do_ref_update = 0;
2075 		int do_packfile_install = 0;
2076 
2077 		if ((n = imsg_get(ibuf, &imsg)) == -1)
2078 			fatal("%s: imsg_get error", __func__);
2079 		if (n == 0)	/* No more messages. */
2080 			break;
2081 
2082 		switch (imsg.hdr.type) {
2083 		case GOTD_IMSG_ERROR:
2084 			do_disconnect = 1;
2085 			err = gotd_imsg_recv_error(&client_id, &imsg);
2086 			break;
2087 		case GOTD_IMSG_REPO_CHILD_READY:
2088 			do_list_refs = 1;
2089 			break;
2090 		case GOTD_IMSG_PACKFILE_DONE:
2091 			do_disconnect = 1;
2092 			err = recv_packfile_done(&client_id, &imsg);
2093 			break;
2094 		case GOTD_IMSG_PACKFILE_INSTALL:
2095 			err = recv_packfile_install(&client_id, &imsg);
2096 			if (err == NULL)
2097 				do_packfile_install = 1;
2098 			break;
2099 		case GOTD_IMSG_REF_UPDATES_START:
2100 			err = recv_ref_updates_start(&client_id, &imsg);
2101 			if (err == NULL)
2102 				do_ref_updates = 1;
2103 			break;
2104 		case GOTD_IMSG_REF_UPDATE:
2105 			err = recv_ref_update(&client_id, &imsg);
2106 			if (err == NULL)
2107 				do_ref_update = 1;
2108 			break;
2109 		default:
2110 			log_debug("unexpected imsg %d", imsg.hdr.type);
2111 			break;
2112 		}
2113 
2114 		if (!verify_imsg_src(client, proc, &imsg)) {
2115 			log_debug("dropping imsg type %d from PID %d",
2116 			    imsg.hdr.type, proc->pid);
2117 			imsg_free(&imsg);
2118 			continue;
2119 		}
2120 		if (err)
2121 			log_warnx("uid %d: %s", client->euid, err->msg);
2122 
2123 		if (do_disconnect) {
2124 			if (err)
2125 				disconnect_on_error(client, err);
2126 			else
2127 				disconnect(client);
2128 		} else {
2129 			if (do_list_refs)
2130 				err = list_refs_request(client, iev);
2131 			else if (do_packfile_install)
2132 				err = install_pack(client, proc->repo_path,
2133 				    &imsg);
2134 			else if (do_ref_updates)
2135 				err = begin_ref_updates(client, &imsg);
2136 			else if (do_ref_update)
2137 				err = update_ref(client, proc->repo_path,
2138 				    &imsg);
2139 			if (err)
2140 				log_warnx("uid %d: %s", client->euid, err->msg);
2141 		}
2142 		imsg_free(&imsg);
2143 	}
2144 done:
2145 	if (!shut) {
2146 		gotd_imsg_event_add(iev);
2147 	} else {
2148 		/* This pipe is dead. Remove its event handler */
2149 		event_del(&iev->ev);
2150 		event_loopexit(NULL);
2151 	}
2152 }
2153 
2154 static pid_t
2155 start_child(enum gotd_procid proc_id, const char *repo_path,
2156     char *argv0, const char *confpath, int fd, int daemonize, int verbosity)
2157 {
2158 	char	*argv[11];
2159 	int	 argc = 0;
2160 	pid_t	 pid;
2161 
2162 	switch (pid = fork()) {
2163 	case -1:
2164 		fatal("cannot fork");
2165 	case 0:
2166 		break;
2167 	default:
2168 		close(fd);
2169 		return pid;
2170 	}
2171 
2172 	if (fd != GOTD_FILENO_MSG_PIPE) {
2173 		if (dup2(fd, GOTD_FILENO_MSG_PIPE) == -1)
2174 			fatal("cannot setup imsg fd");
2175 	} else if (fcntl(fd, F_SETFD, 0) == -1)
2176 		fatal("cannot setup imsg fd");
2177 
2178 	argv[argc++] = argv0;
2179 	switch (proc_id) {
2180 	case PROC_LISTEN:
2181 		argv[argc++] = (char *)"-L";
2182 		break;
2183 	case PROC_AUTH:
2184 		argv[argc++] = (char *)"-A";
2185 		break;
2186 	case PROC_REPO_READ:
2187 		argv[argc++] = (char *)"-R";
2188 		break;
2189 	case PROC_REPO_WRITE:
2190 		argv[argc++] = (char *)"-W";
2191 		break;
2192 	default:
2193 		fatalx("invalid process id %d", proc_id);
2194 	}
2195 
2196 	argv[argc++] = (char *)"-f";
2197 	argv[argc++] = (char *)confpath;
2198 
2199 	if (repo_path) {
2200 		argv[argc++] = (char *)"-P";
2201 		argv[argc++] = (char *)repo_path;
2202 	}
2203 
2204 	if (!daemonize)
2205 		argv[argc++] = (char *)"-d";
2206 	if (verbosity > 0)
2207 		argv[argc++] = (char *)"-v";
2208 	if (verbosity > 1)
2209 		argv[argc++] = (char *)"-v";
2210 	argv[argc++] = NULL;
2211 
2212 	execvp(argv0, argv);
2213 	fatal("execvp");
2214 }
2215 
2216 static void
2217 start_listener(char *argv0, const char *confpath, int daemonize, int verbosity)
2218 {
2219 	struct gotd_child_proc *proc = &gotd.listen_proc;
2220 
2221 	proc->type = PROC_LISTEN;
2222 
2223 	if (socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK,
2224 	    PF_UNSPEC, proc->pipe) == -1)
2225 		fatal("socketpair");
2226 
2227 	proc->pid = start_child(proc->type, NULL, argv0, confpath,
2228 	    proc->pipe[1], daemonize, verbosity);
2229 	imsg_init(&proc->iev.ibuf, proc->pipe[0]);
2230 	proc->iev.handler = gotd_dispatch_listener;
2231 	proc->iev.events = EV_READ;
2232 	proc->iev.handler_arg = NULL;
2233 }
2234 
2235 static const struct got_error *
2236 start_repo_child(struct gotd_client *client, enum gotd_procid proc_type,
2237     struct gotd_repo *repo, char *argv0, const char *confpath,
2238     int daemonize, int verbosity)
2239 {
2240 	struct gotd_child_proc *proc;
2241 
2242 	if (proc_type != PROC_REPO_READ && proc_type != PROC_REPO_WRITE)
2243 		return got_error_msg(GOT_ERR_NOT_IMPL, "bad process type");
2244 
2245 	proc = calloc(1, sizeof(*proc));
2246 	if (proc == NULL)
2247 		return got_error_from_errno("calloc");
2248 
2249 	proc->type = proc_type;
2250 	if (strlcpy(proc->repo_name, repo->name,
2251 	    sizeof(proc->repo_name)) >= sizeof(proc->repo_name))
2252 		fatalx("repository name too long: %s", repo->name);
2253 	log_debug("starting %s for repository %s",
2254 	    proc->type == PROC_REPO_READ ? "reader" : "writer", repo->name);
2255 	if (realpath(repo->path, proc->repo_path) == NULL)
2256 		fatal("%s", repo->path);
2257 	if (socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK,
2258 	    PF_UNSPEC, proc->pipe) == -1)
2259 		fatal("socketpair");
2260 	proc->pid = start_child(proc->type, proc->repo_path, argv0,
2261 	    confpath, proc->pipe[1], daemonize, verbosity);
2262 	imsg_init(&proc->iev.ibuf, proc->pipe[0]);
2263 	log_debug("proc %s %s is on fd %d",
2264 	    gotd_proc_names[proc->type], proc->repo_path,
2265 	    proc->pipe[0]);
2266 	proc->iev.handler = gotd_dispatch_repo_child;
2267 	proc->iev.events = EV_READ;
2268 	proc->iev.handler_arg = NULL;
2269 	event_set(&proc->iev.ev, proc->iev.ibuf.fd, EV_READ,
2270 	    gotd_dispatch_repo_child, &proc->iev);
2271 	gotd_imsg_event_add(&proc->iev);
2272 
2273 	if (proc->type == PROC_REPO_READ)
2274 		client->repo_read = proc;
2275 	else
2276 		client->repo_write = proc;
2277 
2278 	return NULL;
2279 }
2280 
2281 static const struct got_error *
2282 start_auth_child(struct gotd_client *client, int required_auth,
2283     struct gotd_repo *repo, char *argv0, const char *confpath,
2284     int daemonize, int verbosity)
2285 {
2286 	const struct got_error *err = NULL;
2287 	struct gotd_child_proc *proc;
2288 	struct gotd_imsg_auth iauth;
2289 	int fd;
2290 
2291 	memset(&iauth, 0, sizeof(iauth));
2292 
2293 	fd = dup(client->fd);
2294 	if (fd == -1)
2295 		return got_error_from_errno("dup");
2296 
2297 	proc = calloc(1, sizeof(*proc));
2298 	if (proc == NULL) {
2299 		err = got_error_from_errno("calloc");
2300 		close(fd);
2301 		return err;
2302 	}
2303 
2304 	proc->type = PROC_AUTH;
2305 	if (strlcpy(proc->repo_name, repo->name,
2306 	    sizeof(proc->repo_name)) >= sizeof(proc->repo_name))
2307 		fatalx("repository name too long: %s", repo->name);
2308 	log_debug("starting auth for uid %d repository %s",
2309 	    client->euid, repo->name);
2310 	if (realpath(repo->path, proc->repo_path) == NULL)
2311 		fatal("%s", repo->path);
2312 	if (socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK,
2313 	    PF_UNSPEC, proc->pipe) == -1)
2314 		fatal("socketpair");
2315 	proc->pid = start_child(proc->type, proc->repo_path, argv0,
2316 	    confpath, proc->pipe[1], daemonize, verbosity);
2317 	imsg_init(&proc->iev.ibuf, proc->pipe[0]);
2318 	log_debug("proc %s %s is on fd %d",
2319 	    gotd_proc_names[proc->type], proc->repo_path,
2320 	    proc->pipe[0]);
2321 	proc->iev.handler = gotd_dispatch_auth_child;
2322 	proc->iev.events = EV_READ;
2323 	proc->iev.handler_arg = NULL;
2324 	event_set(&proc->iev.ev, proc->iev.ibuf.fd, EV_READ,
2325 	    gotd_dispatch_auth_child, &proc->iev);
2326 	gotd_imsg_event_add(&proc->iev);
2327 
2328 	iauth.euid = client->euid;
2329 	iauth.egid = client->egid;
2330 	iauth.required_auth = required_auth;
2331 	iauth.client_id = client->id;
2332 	if (gotd_imsg_compose_event(&proc->iev, GOTD_IMSG_AUTHENTICATE,
2333 	    PROC_GOTD, fd, &iauth, sizeof(iauth)) == -1) {
2334 		log_warn("imsg compose AUTHENTICATE");
2335 		close(fd);
2336 		/* Let the auth_timeout handler tidy up. */
2337 	}
2338 
2339 	client->auth = proc;
2340 	client->required_auth = required_auth;
2341 	return NULL;
2342 }
2343 
2344 static void
2345 apply_unveil_repo_readonly(const char *repo_path)
2346 {
2347 	if (unveil(repo_path, "r") == -1)
2348 		fatal("unveil %s", repo_path);
2349 
2350 	if (unveil(NULL, NULL) == -1)
2351 		fatal("unveil");
2352 }
2353 
2354 static void
2355 apply_unveil_none(void)
2356 {
2357 	if (unveil("/", "") == -1)
2358 		fatal("unveil");
2359 
2360 	if (unveil(NULL, NULL) == -1)
2361 		fatal("unveil");
2362 }
2363 
2364 static void
2365 apply_unveil(void)
2366 {
2367 	struct gotd_repo *repo;
2368 
2369 	if (unveil(gotd.argv0, "x") == -1)
2370 		fatal("unveil %s", gotd.argv0);
2371 
2372 	TAILQ_FOREACH(repo, &gotd.repos, entry) {
2373 		if (unveil(repo->path, "rwc") == -1)
2374 			fatal("unveil %s", repo->path);
2375 	}
2376 
2377 	if (unveil(GOT_TMPDIR_STR, "rwc") == -1)
2378 		fatal("unveil %s", GOT_TMPDIR_STR);
2379 
2380 	if (unveil(NULL, NULL) == -1)
2381 		fatal("unveil");
2382 }
2383 
2384 int
2385 main(int argc, char **argv)
2386 {
2387 	const struct got_error *error = NULL;
2388 	int ch, fd = -1, daemonize = 1, verbosity = 0, noaction = 0;
2389 	const char *confpath = GOTD_CONF_PATH;
2390 	char *argv0 = argv[0];
2391 	char title[2048];
2392 	struct passwd *pw = NULL;
2393 	char *repo_path = NULL;
2394 	enum gotd_procid proc_id = PROC_GOTD;
2395 	struct event evsigint, evsigterm, evsighup, evsigusr1;
2396 	int *pack_fds = NULL, *temp_fds = NULL;
2397 
2398 	log_init(1, LOG_DAEMON); /* Log to stderr until daemonized. */
2399 
2400 	while ((ch = getopt(argc, argv, "Adf:LnP:RvW")) != -1) {
2401 		switch (ch) {
2402 		case 'A':
2403 			proc_id = PROC_AUTH;
2404 			break;
2405 		case 'd':
2406 			daemonize = 0;
2407 			break;
2408 		case 'f':
2409 			confpath = optarg;
2410 			break;
2411 		case 'L':
2412 			proc_id = PROC_LISTEN;
2413 			break;
2414 		case 'n':
2415 			noaction = 1;
2416 			break;
2417 		case 'P':
2418 			repo_path = realpath(optarg, NULL);
2419 			if (repo_path == NULL)
2420 				fatal("realpath '%s'", optarg);
2421 			break;
2422 		case 'R':
2423 			proc_id = PROC_REPO_READ;
2424 			break;
2425 		case 'v':
2426 			if (verbosity < 3)
2427 				verbosity++;
2428 			break;
2429 		case 'W':
2430 			proc_id = PROC_REPO_WRITE;
2431 			break;
2432 		default:
2433 			usage();
2434 		}
2435 	}
2436 
2437 	argc -= optind;
2438 	argv += optind;
2439 
2440 	if (argc != 0)
2441 		usage();
2442 
2443 	/* Require an absolute path in argv[0] for reliable re-exec. */
2444 	if (!got_path_is_absolute(argv0))
2445 		fatalx("bad path \"%s\": must be an absolute path", argv0);
2446 
2447 	if (geteuid() && (proc_id == PROC_GOTD || proc_id == PROC_LISTEN))
2448 		fatalx("need root privileges");
2449 
2450 	log_init(daemonize ? 0 : 1, LOG_DAEMON);
2451 	log_setverbose(verbosity);
2452 
2453 	if (parse_config(confpath, proc_id, &gotd) != 0)
2454 		return 1;
2455 
2456 	gotd.argv0 = argv0;
2457 	gotd.daemonize = daemonize;
2458 	gotd.verbosity = verbosity;
2459 	gotd.confpath = confpath;
2460 
2461 	if (proc_id == PROC_GOTD &&
2462 	    (gotd.nrepos == 0 || TAILQ_EMPTY(&gotd.repos)))
2463 		fatalx("no repository defined in configuration file");
2464 
2465 	pw = getpwnam(gotd.user_name);
2466 	if (pw == NULL)
2467 		fatalx("user %s not found", gotd.user_name);
2468 
2469 	if (pw->pw_uid == 0) {
2470 		fatalx("cannot run %s as %s: the user running %s "
2471 		    "must not be the superuser",
2472 		    getprogname(), pw->pw_name, getprogname());
2473 	}
2474 
2475 	if (proc_id == PROC_LISTEN &&
2476 	    !got_path_is_absolute(gotd.unix_socket_path))
2477 		fatalx("bad unix socket path \"%s\": must be an absolute path",
2478 		    gotd.unix_socket_path);
2479 
2480 	if (noaction)
2481 		return 0;
2482 
2483 	if (proc_id == PROC_GOTD) {
2484 		gotd.pid = getpid();
2485 		snprintf(title, sizeof(title), "%s", gotd_proc_names[proc_id]);
2486 		start_listener(argv0, confpath, daemonize, verbosity);
2487 		arc4random_buf(&clients_hash_key, sizeof(clients_hash_key));
2488 		if (daemonize && daemon(1, 0) == -1)
2489 			fatal("daemon");
2490 	} else if (proc_id == PROC_LISTEN) {
2491 		snprintf(title, sizeof(title), "%s", gotd_proc_names[proc_id]);
2492 		if (verbosity) {
2493 			log_info("socket: %s", gotd.unix_socket_path);
2494 			log_info("user: %s", pw->pw_name);
2495 		}
2496 
2497 		fd = unix_socket_listen(gotd.unix_socket_path, pw->pw_uid,
2498 		    pw->pw_gid);
2499 		if (fd == -1) {
2500 			fatal("cannot listen on unix socket %s",
2501 			    gotd.unix_socket_path);
2502 		}
2503 		if (daemonize && daemon(0, 0) == -1)
2504 			fatal("daemon");
2505 	} else if (proc_id == PROC_AUTH) {
2506 		snprintf(title, sizeof(title), "%s %s",
2507 		    gotd_proc_names[proc_id], repo_path);
2508 		if (daemonize && daemon(0, 0) == -1)
2509 			fatal("daemon");
2510 	} else if (proc_id == PROC_REPO_READ || proc_id == PROC_REPO_WRITE) {
2511 		error = got_repo_pack_fds_open(&pack_fds);
2512 		if (error != NULL)
2513 			fatalx("cannot open pack tempfiles: %s", error->msg);
2514 		error = got_repo_temp_fds_open(&temp_fds);
2515 		if (error != NULL)
2516 			fatalx("cannot open pack tempfiles: %s", error->msg);
2517 		if (repo_path == NULL)
2518 			fatalx("repository path not specified");
2519 		snprintf(title, sizeof(title), "%s %s",
2520 		    gotd_proc_names[proc_id], repo_path);
2521 		if (daemonize && daemon(0, 0) == -1)
2522 			fatal("daemon");
2523 	} else
2524 		fatal("invalid process id %d", proc_id);
2525 
2526 	setproctitle("%s", title);
2527 	log_procinit(title);
2528 
2529 	/* Drop root privileges. */
2530 	if (setgid(pw->pw_gid) == -1)
2531 		fatal("setgid %d failed", pw->pw_gid);
2532 	if (setuid(pw->pw_uid) == -1)
2533 		fatal("setuid %d failed", pw->pw_uid);
2534 
2535 	event_init();
2536 
2537 	switch (proc_id) {
2538 	case PROC_GOTD:
2539 #ifndef PROFILE
2540 		if (pledge("stdio rpath wpath cpath proc exec "
2541 		    "sendfd recvfd fattr flock unveil", NULL) == -1)
2542 			err(1, "pledge");
2543 #endif
2544 		break;
2545 	case PROC_LISTEN:
2546 #ifndef PROFILE
2547 		if (pledge("stdio sendfd unix unveil", NULL) == -1)
2548 			err(1, "pledge");
2549 #endif
2550 		/*
2551 		 * Ensure that AF_UNIX bind(2) cannot be used with any other
2552 		 * sockets by revoking all filesystem access via unveil(2).
2553 		 */
2554 		apply_unveil_none();
2555 
2556 		listen_main(title, fd, gotd.connection_limits,
2557 		    gotd.nconnection_limits);
2558 		/* NOTREACHED */
2559 		break;
2560 	case PROC_AUTH:
2561 #ifndef PROFILE
2562 		if (pledge("stdio getpw recvfd unix unveil", NULL) == -1)
2563 			err(1, "pledge");
2564 #endif
2565 		/*
2566 		 * We need the "unix" pledge promise for getpeername(2) only.
2567 		 * Ensure that AF_UNIX bind(2) cannot be used by revoking all
2568 		 * filesystem access via unveil(2). Access to password database
2569 		 * files will still work since "getpw" bypasses unveil(2).
2570 		 */
2571 		apply_unveil_none();
2572 
2573 		auth_main(title, &gotd.repos, repo_path);
2574 		/* NOTREACHED */
2575 		break;
2576 	case PROC_REPO_READ:
2577 #ifndef PROFILE
2578 		if (pledge("stdio rpath recvfd unveil", NULL) == -1)
2579 			err(1, "pledge");
2580 #endif
2581 		apply_unveil_repo_readonly(repo_path);
2582 		repo_read_main(title, repo_path, pack_fds, temp_fds);
2583 		/* NOTREACHED */
2584 		exit(0);
2585 	case PROC_REPO_WRITE:
2586 #ifndef PROFILE
2587 		if (pledge("stdio rpath recvfd unveil", NULL) == -1)
2588 			err(1, "pledge");
2589 #endif
2590 		apply_unveil_repo_readonly(repo_path);
2591 		repo_write_main(title, repo_path, pack_fds, temp_fds);
2592 		/* NOTREACHED */
2593 		exit(0);
2594 	default:
2595 		fatal("invalid process id %d", proc_id);
2596 	}
2597 
2598 	if (proc_id != PROC_GOTD)
2599 		fatal("invalid process id %d", proc_id);
2600 
2601 	apply_unveil();
2602 
2603 	signal_set(&evsigint, SIGINT, gotd_sighdlr, NULL);
2604 	signal_set(&evsigterm, SIGTERM, gotd_sighdlr, NULL);
2605 	signal_set(&evsighup, SIGHUP, gotd_sighdlr, NULL);
2606 	signal_set(&evsigusr1, SIGUSR1, gotd_sighdlr, NULL);
2607 	signal(SIGPIPE, SIG_IGN);
2608 
2609 	signal_add(&evsigint, NULL);
2610 	signal_add(&evsigterm, NULL);
2611 	signal_add(&evsighup, NULL);
2612 	signal_add(&evsigusr1, NULL);
2613 
2614 	gotd_imsg_event_add(&gotd.listen_proc.iev);
2615 
2616 	event_dispatch();
2617 
2618 	if (pack_fds)
2619 		got_repo_pack_fds_close(pack_fds);
2620 	free(repo_path);
2621 	return 0;
2622 }