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Date:: Fri Jan 6 09:33:00 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 	if (gotd_imsg_compose_event(&client->repo_write->iev,
888 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[0],
889 	        &ipipe, sizeof(ipipe)) == -1) {
890 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
891 		pipe[0] = -1;
892 		goto done;
893 	}
894 	pipe[0] = -1;
895 
896 	if (gotd_imsg_compose_event(&client->repo_write->iev,
897 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[1],
898 	        &ipipe, sizeof(ipipe)) == -1)
899 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
900 	pipe[1] = -1;
901 
902 	if (asprintf(&basepath, "%s/%s/receiving-from-uid-%d.pack",
903 	    client->repo_write->repo_path, GOT_OBJECTS_PACK_DIR,
904 	    client->euid) == -1) {
905 		err = got_error_from_errno("asprintf");
906 		goto done;
907 	}
908 
909 	err = got_opentemp_named_fd(&pack_path, &packfd, basepath, "");
910 	if (err)
911 		goto done;
912 
913 	free(basepath);
914 	if (asprintf(&basepath, "%s/%s/receiving-from-uid-%d.idx",
915 	    client->repo_write->repo_path, GOT_OBJECTS_PACK_DIR,
916 	    client->euid) == -1) {
917 		err = got_error_from_errno("asprintf");
918 		basepath = NULL;
919 		goto done;
920 	}
921 	err = got_opentemp_named_fd(&idx_path, &idxfd, basepath, "");
922 	if (err)
923 		goto done;
924 
925 	memset(&ifile, 0, sizeof(ifile));
926 	ifile.client_id = client->id;
927 	if (gotd_imsg_compose_event(&client->repo_write->iev,
928 	    GOTD_IMSG_PACKIDX_FILE, PROC_GOTD, idxfd,
929 	    &ifile, sizeof(ifile)) == -1) {
930 		err = got_error_from_errno("imsg compose PACKIDX_FILE");
931 		idxfd = -1;
932 		goto done;
933 	}
934 	idxfd = -1;
935 
936 	memset(&ipack, 0, sizeof(ipack));
937 	ipack.client_id = client->id;
938 	if (client_has_capability(client, GOT_CAPA_REPORT_STATUS))
939 		ipack.report_status = 1;
940 
941 	if (gotd_imsg_compose_event(&client->repo_write->iev,
942 	    GOTD_IMSG_RECV_PACKFILE, PROC_GOTD, packfd,
943 	    &ipack, sizeof(ipack)) == -1) {
944 		err = got_error_from_errno("imsg compose RECV_PACKFILE");
945 		packfd = -1;
946 		goto done;
947 	}
948 	packfd = -1;
949 
950 done:
951 	free(basepath);
952 	if (pipe[0] != -1 && close(pipe[0]) == -1 && err == NULL)
953 		err = got_error_from_errno("close");
954 	if (pipe[1] != -1 && close(pipe[1]) == -1 && err == NULL)
955 		err = got_error_from_errno("close");
956 	if (packfd != -1 && close(packfd) == -1 && err == NULL)
957 		err = got_error_from_errno("close");
958 	if (idxfd != -1 && close(idxfd) == -1 && err == NULL)
959 		err = got_error_from_errno("close");
960 	if (err) {
961 		free(pack_path);
962 		free(idx_path);
963 	} else {
964 		client->packfile_path = pack_path;
965 		client->packidx_path = idx_path;
966 	}
967 	return err;
968 }
969 
970 static void
971 gotd_request(int fd, short events, void *arg)
972 {
973 	struct gotd_imsgev *iev = arg;
974 	struct imsgbuf *ibuf = &iev->ibuf;
975 	struct gotd_client *client = iev->handler_arg;
976 	const struct got_error *err = NULL;
977 	struct imsg imsg;
978 	ssize_t n;
979 
980 	if (events & EV_WRITE) {
981 		while (ibuf->w.queued) {
982 			n = msgbuf_write(&ibuf->w);
983 			if (n == -1 && errno == EPIPE) {
984 				/*
985 				 * The client has closed its socket.
986 				 * This can happen when Git clients are
987 				 * done sending pack file data.
988 				 */
989 				msgbuf_clear(&ibuf->w);
990 				continue;
991 			} else if (n == -1 && errno != EAGAIN) {
992 				err = got_error_from_errno("imsg_flush");
993 				disconnect_on_error(client, err);
994 				return;
995 			}
996 			if (n == 0) {
997 				/* Connection closed. */
998 				err = got_error(GOT_ERR_EOF);
999 				disconnect_on_error(client, err);
1000 				return;
1001 			}
1002 		}
1003 
1004 		/* Disconnect gotctl(8) now that messages have been sent. */
1005 		if (!client_is_reading(client) && !client_is_writing(client)) {
1006 			disconnect(client);
1007 			return;
1008 		}
1009 	}
1010 
1011 	if ((events & EV_READ) == 0)
1012 		return;
1013 
1014 	memset(&imsg, 0, sizeof(imsg));
1015 
1016 	while (err == NULL) {
1017 		err = gotd_imsg_recv(&imsg, ibuf, 0);
1018 		if (err) {
1019 			if (err->code == GOT_ERR_PRIVSEP_READ)
1020 				err = NULL;
1021 			break;
1022 		}
1023 
1024 		evtimer_del(&client->tmo);
1025 
1026 		switch (imsg.hdr.type) {
1027 		case GOTD_IMSG_INFO:
1028 			err = send_info(client);
1029 			break;
1030 		case GOTD_IMSG_STOP:
1031 			err = stop_gotd(client);
1032 			break;
1033 		case GOTD_IMSG_LIST_REFS:
1034 			if (client->state != GOTD_STATE_EXPECT_LIST_REFS) {
1035 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1036 				    "unexpected list-refs request received");
1037 				break;
1038 			}
1039 			err = start_client_session(client, &imsg);
1040 			if (err)
1041 				break;
1042 			break;
1043 		case GOTD_IMSG_CAPABILITIES:
1044 			if (client->state != GOTD_STATE_EXPECT_CAPABILITIES) {
1045 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1046 				    "unexpected capabilities received");
1047 				break;
1048 			}
1049 			log_debug("receiving capabilities from uid %d",
1050 			    client->euid);
1051 			err = recv_capabilities(client, &imsg);
1052 			break;
1053 		case GOTD_IMSG_CAPABILITY:
1054 			if (client->state != GOTD_STATE_EXPECT_CAPABILITIES) {
1055 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1056 				    "unexpected capability received");
1057 				break;
1058 			}
1059 			err = recv_capability(client, &imsg);
1060 			if (err || client->ncapabilities < client->ncapa_alloc)
1061 				break;
1062 			if (client_is_reading(client)) {
1063 				client->state = GOTD_STATE_EXPECT_WANT;
1064 				log_debug("uid %d: expecting want-lines",
1065 				    client->euid);
1066 			} else if (client_is_writing(client)) {
1067 				client->state = GOTD_STATE_EXPECT_REF_UPDATE;
1068 				log_debug("uid %d: expecting ref-update-lines",
1069 				    client->euid);
1070 			} else
1071 				fatalx("client %d is both reading and writing",
1072 				    client->euid);
1073 			break;
1074 		case GOTD_IMSG_WANT:
1075 			if (client->state != GOTD_STATE_EXPECT_WANT) {
1076 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1077 				    "unexpected want-line received");
1078 				break;
1079 			}
1080 			log_debug("received want-line from uid %d",
1081 			    client->euid);
1082 			err = ensure_client_is_reading(client);
1083 			if (err)
1084 				break;
1085 			err = forward_want(client, &imsg);
1086 			break;
1087 		case GOTD_IMSG_REF_UPDATE:
1088 			if (client->state != GOTD_STATE_EXPECT_REF_UPDATE) {
1089 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1090 				    "unexpected ref-update-line received");
1091 				break;
1092 			}
1093 			log_debug("received ref-update-line from uid %d",
1094 			    client->euid);
1095 			err = ensure_client_is_writing(client);
1096 			if (err)
1097 				break;
1098 			err = forward_ref_update(client, &imsg);
1099 			if (err)
1100 				break;
1101 			client->state = GOTD_STATE_EXPECT_MORE_REF_UPDATES;
1102 			break;
1103 		case GOTD_IMSG_HAVE:
1104 			if (client->state != GOTD_STATE_EXPECT_HAVE) {
1105 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1106 				    "unexpected have-line received");
1107 				break;
1108 			}
1109 			log_debug("received have-line from uid %d",
1110 			    client->euid);
1111 			err = ensure_client_is_reading(client);
1112 			if (err)
1113 				break;
1114 			err = forward_have(client, &imsg);
1115 			if (err)
1116 				break;
1117 			break;
1118 		case GOTD_IMSG_FLUSH:
1119 			if (client->state == GOTD_STATE_EXPECT_WANT ||
1120 			    client->state == GOTD_STATE_EXPECT_HAVE) {
1121 				err = ensure_client_is_reading(client);
1122 				if (err)
1123 					break;
1124 			} else if (client->state ==
1125 			    GOTD_STATE_EXPECT_MORE_REF_UPDATES) {
1126 				err = ensure_client_is_writing(client);
1127 				if (err)
1128 					break;
1129 			} else {
1130 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1131 				    "unexpected flush-pkt received");
1132 				break;
1133 			}
1134 			log_debug("received flush-pkt from uid %d",
1135 			    client->euid);
1136 			if (client->state == GOTD_STATE_EXPECT_WANT) {
1137 				client->state = GOTD_STATE_EXPECT_HAVE;
1138 				log_debug("uid %d: expecting have-lines",
1139 				    client->euid);
1140 			} else if (client->state == GOTD_STATE_EXPECT_HAVE) {
1141 				client->state = GOTD_STATE_EXPECT_DONE;
1142 				log_debug("uid %d: expecting 'done'",
1143 				    client->euid);
1144 			} else if (client->state ==
1145 			    GOTD_STATE_EXPECT_MORE_REF_UPDATES) {
1146 				client->state = GOTD_STATE_EXPECT_PACKFILE;
1147 				log_debug("uid %d: expecting packfile",
1148 				    client->euid);
1149 				err = recv_packfile(client);
1150 			} else {
1151 				/* should not happen, see above */
1152 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1153 				    "unexpected client state");
1154 				break;
1155 			}
1156 			break;
1157 		case GOTD_IMSG_DONE:
1158 			if (client->state != GOTD_STATE_EXPECT_HAVE &&
1159 			    client->state != GOTD_STATE_EXPECT_DONE) {
1160 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1161 				    "unexpected flush-pkt received");
1162 				break;
1163 			}
1164 			log_debug("received 'done' from uid %d", client->euid);
1165 			err = ensure_client_is_reading(client);
1166 			if (err)
1167 				break;
1168 			client->state = GOTD_STATE_DONE;
1169 			err = send_packfile(client);
1170 			break;
1171 		default:
1172 			err = got_error(GOT_ERR_PRIVSEP_MSG);
1173 			break;
1174 		}
1175 
1176 		imsg_free(&imsg);
1177 	}
1178 
1179 	if (err) {
1180 		if (err->code != GOT_ERR_EOF ||
1181 		    client->state != GOTD_STATE_EXPECT_PACKFILE)
1182 			disconnect_on_error(client, err);
1183 	} else {
1184 		gotd_imsg_event_add(&client->iev);
1185 		if (client->state == GOTD_STATE_EXPECT_LIST_REFS)
1186 			evtimer_add(&client->tmo, &auth_timeout);
1187 		else
1188 			evtimer_add(&client->tmo, &gotd.request_timeout);
1189 	}
1190 }
1191 
1192 static void
1193 gotd_request_timeout(int fd, short events, void *arg)
1194 {
1195 	struct gotd_client *client = arg;
1196 
1197 	log_debug("disconnecting uid %d due to timeout", client->euid);
1198 	disconnect(client);
1199 }
1200 
1201 static const struct got_error *
1202 recv_connect(uint32_t *client_id, struct imsg *imsg)
1203 {
1204 	const struct got_error *err = NULL;
1205 	struct gotd_imsg_connect iconnect;
1206 	size_t datalen;
1207 	int s = -1;
1208 	struct gotd_client *client = NULL;
1209 
1210 	*client_id = 0;
1211 
1212 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1213 	if (datalen != sizeof(iconnect))
1214 		return got_error(GOT_ERR_PRIVSEP_LEN);
1215 	memcpy(&iconnect, imsg->data, sizeof(iconnect));
1216 
1217 	s = imsg->fd;
1218 	if (s == -1) {
1219 		err = got_error(GOT_ERR_PRIVSEP_NO_FD);
1220 		goto done;
1221 	}
1222 
1223 	if (find_client(iconnect.client_id)) {
1224 		err = got_error_msg(GOT_ERR_CLIENT_ID, "duplicate client ID");
1225 		goto done;
1226 	}
1227 
1228 	client = calloc(1, sizeof(*client));
1229 	if (client == NULL) {
1230 		err = got_error_from_errno("calloc");
1231 		goto done;
1232 	}
1233 
1234 	*client_id = iconnect.client_id;
1235 
1236 	client->state = GOTD_STATE_EXPECT_LIST_REFS;
1237 	client->id = iconnect.client_id;
1238 	client->fd = s;
1239 	s = -1;
1240 	client->delta_cache_fd = -1;
1241 	/* The auth process will verify UID/GID for us. */
1242 	client->euid = iconnect.euid;
1243 	client->egid = iconnect.egid;
1244 	client->nref_updates = -1;
1245 
1246 	imsg_init(&client->iev.ibuf, client->fd);
1247 	client->iev.handler = gotd_request;
1248 	client->iev.events = EV_READ;
1249 	client->iev.handler_arg = client;
1250 
1251 	event_set(&client->iev.ev, client->fd, EV_READ, gotd_request,
1252 	    &client->iev);
1253 	gotd_imsg_event_add(&client->iev);
1254 
1255 	evtimer_set(&client->tmo, gotd_request_timeout, client);
1256 
1257 	add_client(client);
1258 	log_debug("%s: new client uid %d connected on fd %d", __func__,
1259 	    client->euid, client->fd);
1260 done:
1261 	if (err) {
1262 		struct gotd_child_proc *listen_proc = &gotd.listen_proc;
1263 		struct gotd_imsg_disconnect idisconnect;
1264 
1265 		idisconnect.client_id = client->id;
1266 		if (gotd_imsg_compose_event(&listen_proc->iev,
1267 		    GOTD_IMSG_DISCONNECT, PROC_GOTD, -1,
1268 		    &idisconnect, sizeof(idisconnect)) == -1)
1269 			log_warn("imsg compose DISCONNECT");
1270 
1271 		if (s != -1)
1272 			close(s);
1273 	}
1274 
1275 	return err;
1276 }
1277 
1278 static const char *gotd_proc_names[PROC_MAX] = {
1279 	"parent",
1280 	"listen",
1281 	"auth",
1282 	"repo_read",
1283 	"repo_write"
1284 };
1285 
1286 static void
1287 kill_proc(struct gotd_child_proc *proc, int fatal)
1288 {
1289 	if (fatal) {
1290 		log_warnx("sending SIGKILL to PID %d", proc->pid);
1291 		kill(proc->pid, SIGKILL);
1292 	} else
1293 		kill(proc->pid, SIGTERM);
1294 }
1295 
1296 static void
1297 gotd_shutdown(void)
1298 {
1299 	struct gotd_child_proc *proc;
1300 	uint64_t slot;
1301 
1302 	for (slot = 0; slot < nitems(gotd_clients); slot++) {
1303 		struct gotd_client *c, *tmp;
1304 
1305 		STAILQ_FOREACH_SAFE(c, &gotd_clients[slot], entry, tmp)
1306 			disconnect(c);
1307 	}
1308 
1309 	proc = &gotd.listen_proc;
1310 	msgbuf_clear(&proc->iev.ibuf.w);
1311 	close(proc->iev.ibuf.fd);
1312 	kill_proc(proc, 0);
1313 	wait_for_child(proc->pid);
1314 
1315 	log_info("terminating");
1316 	exit(0);
1317 }
1318 
1319 void
1320 gotd_sighdlr(int sig, short event, void *arg)
1321 {
1322 	/*
1323 	 * Normal signal handler rules don't apply because libevent
1324 	 * decouples for us.
1325 	 */
1326 
1327 	switch (sig) {
1328 	case SIGHUP:
1329 		log_info("%s: ignoring SIGHUP", __func__);
1330 		break;
1331 	case SIGUSR1:
1332 		log_info("%s: ignoring SIGUSR1", __func__);
1333 		break;
1334 	case SIGTERM:
1335 	case SIGINT:
1336 		gotd_shutdown();
1337 		log_warnx("gotd terminating");
1338 		exit(0);
1339 		break;
1340 	default:
1341 		fatalx("unexpected signal");
1342 	}
1343 }
1344 
1345 static const struct got_error *
1346 ensure_proc_is_reading(struct gotd_client *client,
1347     struct gotd_child_proc *proc)
1348 {
1349 	if (!client_is_reading(client)) {
1350 		kill_proc(proc, 1);
1351 		return got_error_fmt(GOT_ERR_BAD_PACKET,
1352 		    "PID %d handled a read-request for uid %d but this "
1353 		    "user is not reading from a repository", proc->pid,
1354 		    client->euid);
1355 	}
1356 
1357 	return NULL;
1358 }
1359 
1360 static const struct got_error *
1361 ensure_proc_is_writing(struct gotd_client *client,
1362     struct gotd_child_proc *proc)
1363 {
1364 	if (!client_is_writing(client)) {
1365 		kill_proc(proc, 1);
1366 		return got_error_fmt(GOT_ERR_BAD_PACKET,
1367 		    "PID %d handled a write-request for uid %d but this "
1368 		    "user is not writing to a repository", proc->pid,
1369 		    client->euid);
1370 	}
1371 
1372 	return NULL;
1373 }
1374 
1375 static int
1376 verify_imsg_src(struct gotd_client *client, struct gotd_child_proc *proc,
1377     struct imsg *imsg)
1378 {
1379 	const struct got_error *err;
1380 	struct gotd_child_proc *client_proc;
1381 	int ret = 0;
1382 
1383 	if (proc->type == PROC_REPO_READ || proc->type == PROC_REPO_WRITE) {
1384 		client_proc = get_client_proc(client);
1385 		if (client_proc == NULL)
1386 			fatalx("no process found for uid %d", client->euid);
1387 		if (proc->pid != client_proc->pid) {
1388 			kill_proc(proc, 1);
1389 			log_warnx("received message from PID %d for uid %d, "
1390 			    "while PID %d is the process serving this user",
1391 			    proc->pid, client->euid, client_proc->pid);
1392 			return 0;
1393 		}
1394 	}
1395 
1396 	switch (imsg->hdr.type) {
1397 	case GOTD_IMSG_ERROR:
1398 		ret = 1;
1399 		break;
1400 	case GOTD_IMSG_CONNECT:
1401 		if (proc->type != PROC_LISTEN) {
1402 			err = got_error_fmt(GOT_ERR_BAD_PACKET,
1403 			    "new connection for uid %d from PID %d "
1404 			    "which is not the listen process",
1405 			    proc->pid, client->euid);
1406 		} else
1407 			ret = 1;
1408 		break;
1409 	case GOTD_IMSG_ACCESS_GRANTED:
1410 		if (proc->type != PROC_AUTH) {
1411 			err = got_error_fmt(GOT_ERR_BAD_PACKET,
1412 			    "authentication of uid %d from PID %d "
1413 			    "which is not the auth process",
1414 			    proc->pid, client->euid);
1415 		} else
1416 			ret = 1;
1417 		break;
1418 	case GOTD_IMSG_REPO_CHILD_READY:
1419 		if (proc->type != PROC_REPO_READ &&
1420 		    proc->type != PROC_REPO_WRITE) {
1421 			err = got_error_fmt(GOT_ERR_BAD_PACKET,
1422 			    "unexpected \"ready\" signal from PID %d",
1423 			    proc->pid);
1424 		} else
1425 			ret = 1;
1426 		break;
1427 	case GOTD_IMSG_PACKFILE_DONE:
1428 		err = ensure_proc_is_reading(client, proc);
1429 		if (err)
1430 			log_warnx("uid %d: %s", client->euid, err->msg);
1431 		else
1432 			ret = 1;
1433 		break;
1434 	case GOTD_IMSG_PACKFILE_INSTALL:
1435 	case GOTD_IMSG_REF_UPDATES_START:
1436 	case GOTD_IMSG_REF_UPDATE:
1437 		err = ensure_proc_is_writing(client, proc);
1438 		if (err)
1439 			log_warnx("uid %d: %s", client->euid, err->msg);
1440 		else
1441 			ret = 1;
1442 		break;
1443 	default:
1444 		log_debug("%s: unexpected imsg %d", __func__, imsg->hdr.type);
1445 		break;
1446 	}
1447 
1448 	return ret;
1449 }
1450 
1451 static const struct got_error *
1452 list_refs_request(struct gotd_client *client, struct gotd_imsgev *iev)
1453 {
1454 	static const struct got_error *err;
1455 	struct gotd_imsg_list_refs_internal ilref;
1456 	int fd;
1457 
1458 	memset(&ilref, 0, sizeof(ilref));
1459 	ilref.client_id = client->id;
1460 
1461 	fd = dup(client->fd);
1462 	if (fd == -1)
1463 		return got_error_from_errno("dup");
1464 
1465 	if (gotd_imsg_compose_event(iev, GOTD_IMSG_LIST_REFS_INTERNAL,
1466 	    PROC_GOTD, fd, &ilref, sizeof(ilref)) == -1) {
1467 		err = got_error_from_errno("imsg compose WANT");
1468 		close(fd);
1469 		return err;
1470 	}
1471 
1472 	client->state = GOTD_STATE_EXPECT_CAPABILITIES;
1473 	log_debug("uid %d: expecting capabilities", client->euid);
1474 	return NULL;
1475 }
1476 
1477 static const struct got_error *
1478 recv_packfile_done(uint32_t *client_id, struct imsg *imsg)
1479 {
1480 	struct gotd_imsg_packfile_done idone;
1481 	size_t datalen;
1482 
1483 	log_debug("packfile-done received");
1484 
1485 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1486 	if (datalen != sizeof(idone))
1487 		return got_error(GOT_ERR_PRIVSEP_LEN);
1488 	memcpy(&idone, imsg->data, sizeof(idone));
1489 
1490 	*client_id = idone.client_id;
1491 	return NULL;
1492 }
1493 
1494 static const struct got_error *
1495 recv_packfile_install(uint32_t *client_id, struct imsg *imsg)
1496 {
1497 	struct gotd_imsg_packfile_install inst;
1498 	size_t datalen;
1499 
1500 	log_debug("packfile-install received");
1501 
1502 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1503 	if (datalen != sizeof(inst))
1504 		return got_error(GOT_ERR_PRIVSEP_LEN);
1505 	memcpy(&inst, imsg->data, sizeof(inst));
1506 
1507 	*client_id = inst.client_id;
1508 	return NULL;
1509 }
1510 
1511 static const struct got_error *
1512 recv_ref_updates_start(uint32_t *client_id, struct imsg *imsg)
1513 {
1514 	struct gotd_imsg_ref_updates_start istart;
1515 	size_t datalen;
1516 
1517 	log_debug("ref-updates-start received");
1518 
1519 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1520 	if (datalen != sizeof(istart))
1521 		return got_error(GOT_ERR_PRIVSEP_LEN);
1522 	memcpy(&istart, imsg->data, sizeof(istart));
1523 
1524 	*client_id = istart.client_id;
1525 	return NULL;
1526 }
1527 
1528 static const struct got_error *
1529 recv_ref_update(uint32_t *client_id, struct imsg *imsg)
1530 {
1531 	struct gotd_imsg_ref_update iref;
1532 	size_t datalen;
1533 
1534 	log_debug("ref-update received");
1535 
1536 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1537 	if (datalen < sizeof(iref))
1538 		return got_error(GOT_ERR_PRIVSEP_LEN);
1539 	memcpy(&iref, imsg->data, sizeof(iref));
1540 
1541 	*client_id = iref.client_id;
1542 	return NULL;
1543 }
1544 
1545 static const struct got_error *
1546 send_ref_update_ok(struct gotd_client *client,
1547     struct gotd_imsg_ref_update *iref, const char *refname)
1548 {
1549 	struct gotd_imsg_ref_update_ok iok;
1550 	struct ibuf *wbuf;
1551 	size_t len;
1552 
1553 	memset(&iok, 0, sizeof(iok));
1554 	iok.client_id = client->id;
1555 	memcpy(iok.old_id, iref->old_id, SHA1_DIGEST_LENGTH);
1556 	memcpy(iok.new_id, iref->new_id, SHA1_DIGEST_LENGTH);
1557 	iok.name_len = strlen(refname);
1558 
1559 	len = sizeof(iok) + iok.name_len;
1560 	wbuf = imsg_create(&client->iev.ibuf, GOTD_IMSG_REF_UPDATE_OK,
1561 	    PROC_GOTD, gotd.pid, len);
1562 	if (wbuf == NULL)
1563 		return got_error_from_errno("imsg_create REF_UPDATE_OK");
1564 
1565 	if (imsg_add(wbuf, &iok, sizeof(iok)) == -1)
1566 		return got_error_from_errno("imsg_add REF_UPDATE_OK");
1567 	if (imsg_add(wbuf, refname, iok.name_len) == -1)
1568 		return got_error_from_errno("imsg_add REF_UPDATE_OK");
1569 
1570 	wbuf->fd = -1;
1571 	imsg_close(&client->iev.ibuf, wbuf);
1572 	gotd_imsg_event_add(&client->iev);
1573 	return NULL;
1574 }
1575 
1576 static void
1577 send_refs_updated(struct gotd_client *client)
1578 {
1579 	if (gotd_imsg_compose_event(&client->iev,
1580 	    GOTD_IMSG_REFS_UPDATED, PROC_GOTD, -1, NULL, 0) == -1)
1581 		log_warn("imsg compose REFS_UPDATED");
1582 }
1583 
1584 static const struct got_error *
1585 send_ref_update_ng(struct gotd_client *client,
1586     struct gotd_imsg_ref_update *iref, const char *refname,
1587     const char *reason)
1588 {
1589 	const struct got_error *ng_err;
1590 	struct gotd_imsg_ref_update_ng ing;
1591 	struct ibuf *wbuf;
1592 	size_t len;
1593 
1594 	memset(&ing, 0, sizeof(ing));
1595 	ing.client_id = client->id;
1596 	memcpy(ing.old_id, iref->old_id, SHA1_DIGEST_LENGTH);
1597 	memcpy(ing.new_id, iref->new_id, SHA1_DIGEST_LENGTH);
1598 	ing.name_len = strlen(refname);
1599 
1600 	ng_err = got_error_fmt(GOT_ERR_REF_BUSY, "%s", reason);
1601 	ing.reason_len = strlen(ng_err->msg);
1602 
1603 	len = sizeof(ing) + ing.name_len + ing.reason_len;
1604 	wbuf = imsg_create(&client->iev.ibuf, GOTD_IMSG_REF_UPDATE_NG,
1605 	    PROC_GOTD, gotd.pid, len);
1606 	if (wbuf == NULL)
1607 		return got_error_from_errno("imsg_create REF_UPDATE_NG");
1608 
1609 	if (imsg_add(wbuf, &ing, sizeof(ing)) == -1)
1610 		return got_error_from_errno("imsg_add REF_UPDATE_NG");
1611 	if (imsg_add(wbuf, refname, ing.name_len) == -1)
1612 		return got_error_from_errno("imsg_add REF_UPDATE_NG");
1613 	if (imsg_add(wbuf, ng_err->msg, ing.reason_len) == -1)
1614 		return got_error_from_errno("imsg_add REF_UPDATE_NG");
1615 
1616 	wbuf->fd = -1;
1617 	imsg_close(&client->iev.ibuf, wbuf);
1618 	gotd_imsg_event_add(&client->iev);
1619 	return NULL;
1620 }
1621 
1622 static const struct got_error *
1623 install_pack(struct gotd_client *client, const char *repo_path,
1624     struct imsg *imsg)
1625 {
1626 	const struct got_error *err = NULL;
1627 	struct gotd_imsg_packfile_install inst;
1628 	char hex[SHA1_DIGEST_STRING_LENGTH];
1629 	size_t datalen;
1630 	char *packfile_path = NULL, *packidx_path = NULL;
1631 
1632 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1633 	if (datalen != sizeof(inst))
1634 		return got_error(GOT_ERR_PRIVSEP_LEN);
1635 	memcpy(&inst, imsg->data, sizeof(inst));
1636 
1637 	if (client->packfile_path == NULL)
1638 		return got_error_msg(GOT_ERR_BAD_REQUEST,
1639 		    "client has no pack file");
1640 	if (client->packidx_path == NULL)
1641 		return got_error_msg(GOT_ERR_BAD_REQUEST,
1642 		    "client has no pack file index");
1643 
1644 	if (got_sha1_digest_to_str(inst.pack_sha1, hex, sizeof(hex)) == NULL)
1645 		return got_error_msg(GOT_ERR_NO_SPACE,
1646 		    "could not convert pack file SHA1 to hex");
1647 
1648 	if (asprintf(&packfile_path, "/%s/%s/pack-%s.pack",
1649 	    repo_path, GOT_OBJECTS_PACK_DIR, hex) == -1) {
1650 		err = got_error_from_errno("asprintf");
1651 		goto done;
1652 	}
1653 
1654 	if (asprintf(&packidx_path, "/%s/%s/pack-%s.idx",
1655 	    repo_path, GOT_OBJECTS_PACK_DIR, hex) == -1) {
1656 		err = got_error_from_errno("asprintf");
1657 		goto done;
1658 	}
1659 
1660 	if (rename(client->packfile_path, packfile_path) == -1) {
1661 		err = got_error_from_errno3("rename", client->packfile_path,
1662 		    packfile_path);
1663 		goto done;
1664 	}
1665 
1666 	free(client->packfile_path);
1667 	client->packfile_path = NULL;
1668 
1669 	if (rename(client->packidx_path, packidx_path) == -1) {
1670 		err = got_error_from_errno3("rename", client->packidx_path,
1671 		    packidx_path);
1672 		goto done;
1673 	}
1674 
1675 	free(client->packidx_path);
1676 	client->packidx_path = NULL;
1677 done:
1678 	free(packfile_path);
1679 	free(packidx_path);
1680 	return err;
1681 }
1682 
1683 static const struct got_error *
1684 begin_ref_updates(struct gotd_client *client, struct imsg *imsg)
1685 {
1686 	struct gotd_imsg_ref_updates_start istart;
1687 	size_t datalen;
1688 
1689 	if (client->nref_updates != -1)
1690 		return got_error(GOT_ERR_PRIVSEP_MSG);
1691 
1692 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1693 	if (datalen != sizeof(istart))
1694 		return got_error(GOT_ERR_PRIVSEP_LEN);
1695 	memcpy(&istart, imsg->data, sizeof(istart));
1696 
1697 	if (istart.nref_updates <= 0)
1698 		return got_error(GOT_ERR_PRIVSEP_MSG);
1699 
1700 	client->nref_updates = istart.nref_updates;
1701 	return NULL;
1702 }
1703 
1704 static const struct got_error *
1705 update_ref(struct gotd_client *client, const char *repo_path,
1706     struct imsg *imsg)
1707 {
1708 	const struct got_error *err = NULL;
1709 	struct got_repository *repo = NULL;
1710 	struct got_reference *ref = NULL;
1711 	struct gotd_imsg_ref_update iref;
1712 	struct got_object_id old_id, new_id;
1713 	struct got_object_id *id = NULL;
1714 	struct got_object *obj = NULL;
1715 	char *refname = NULL;
1716 	size_t datalen;
1717 	int locked = 0;
1718 
1719 	log_debug("update-ref from uid %d", client->euid);
1720 
1721 	if (client->nref_updates <= 0)
1722 		return got_error(GOT_ERR_PRIVSEP_MSG);
1723 
1724 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1725 	if (datalen < sizeof(iref))
1726 		return got_error(GOT_ERR_PRIVSEP_LEN);
1727 	memcpy(&iref, imsg->data, sizeof(iref));
1728 	if (datalen != sizeof(iref) + iref.name_len)
1729 		return got_error(GOT_ERR_PRIVSEP_LEN);
1730 	refname = malloc(iref.name_len + 1);
1731 	if (refname == NULL)
1732 		return got_error_from_errno("malloc");
1733 	memcpy(refname, imsg->data + sizeof(iref), iref.name_len);
1734 	refname[iref.name_len] = '\0';
1735 
1736 	log_debug("updating ref %s for uid %d", refname, client->euid);
1737 
1738 	err = got_repo_open(&repo, repo_path, NULL, NULL);
1739 	if (err)
1740 		goto done;
1741 
1742 	memcpy(old_id.sha1, iref.old_id, SHA1_DIGEST_LENGTH);
1743 	memcpy(new_id.sha1, iref.new_id, SHA1_DIGEST_LENGTH);
1744 	err = got_object_open(&obj, repo, &new_id);
1745 	if (err)
1746 		goto done;
1747 
1748 	if (iref.ref_is_new) {
1749 		err = got_ref_open(&ref, repo, refname, 0);
1750 		if (err) {
1751 			if (err->code != GOT_ERR_NOT_REF)
1752 				goto done;
1753 			err = got_ref_alloc(&ref, refname, &new_id);
1754 			if (err)
1755 				goto done;
1756 			err = got_ref_write(ref, repo); /* will lock/unlock */
1757 			if (err)
1758 				goto done;
1759 		} else {
1760 			err = got_error_fmt(GOT_ERR_REF_BUSY,
1761 			    "%s has been created by someone else "
1762 			    "while transaction was in progress",
1763 			    got_ref_get_name(ref));
1764 			goto done;
1765 		}
1766 	} else {
1767 		err = got_ref_open(&ref, repo, refname, 1 /* lock */);
1768 		if (err)
1769 			goto done;
1770 		locked = 1;
1771 
1772 		err = got_ref_resolve(&id, repo, ref);
1773 		if (err)
1774 			goto done;
1775 
1776 		if (got_object_id_cmp(id, &old_id) != 0) {
1777 			err = got_error_fmt(GOT_ERR_REF_BUSY,
1778 			    "%s has been modified by someone else "
1779 			    "while transaction was in progress",
1780 			    got_ref_get_name(ref));
1781 			goto done;
1782 		}
1783 
1784 		err = got_ref_change_ref(ref, &new_id);
1785 		if (err)
1786 			goto done;
1787 
1788 		err = got_ref_write(ref, repo);
1789 		if (err)
1790 			goto done;
1791 
1792 		free(id);
1793 		id = NULL;
1794 	}
1795 done:
1796 	if (err) {
1797 		if (err->code == GOT_ERR_LOCKFILE_TIMEOUT) {
1798 			err = got_error_fmt(GOT_ERR_LOCKFILE_TIMEOUT,
1799 			    "could not acquire exclusive file lock for %s",
1800 			    refname);
1801 		}
1802 		send_ref_update_ng(client, &iref, refname, err->msg);
1803 	} else
1804 		send_ref_update_ok(client, &iref, refname);
1805 
1806 	if (client->nref_updates > 0) {
1807 		client->nref_updates--;
1808 		if (client->nref_updates == 0)
1809 			send_refs_updated(client);
1810 
1811 	}
1812 	if (locked) {
1813 		const struct got_error *unlock_err;
1814 		unlock_err = got_ref_unlock(ref);
1815 		if (unlock_err && err == NULL)
1816 			err = unlock_err;
1817 	}
1818 	if (ref)
1819 		got_ref_close(ref);
1820 	if (obj)
1821 		got_object_close(obj);
1822 	if (repo)
1823 		got_repo_close(repo);
1824 	free(refname);
1825 	free(id);
1826 	return err;
1827 }
1828 
1829 static void
1830 gotd_dispatch_listener(int fd, short event, void *arg)
1831 {
1832 	struct gotd_imsgev *iev = arg;
1833 	struct imsgbuf *ibuf = &iev->ibuf;
1834 	struct gotd_child_proc *proc = &gotd.listen_proc;
1835 	ssize_t n;
1836 	int shut = 0;
1837 	struct imsg imsg;
1838 
1839 	if (proc->iev.ibuf.fd != fd)
1840 		fatalx("%s: unexpected fd %d", __func__, fd);
1841 
1842 	if (event & EV_READ) {
1843 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1844 			fatal("imsg_read error");
1845 		if (n == 0) {
1846 			/* Connection closed. */
1847 			shut = 1;
1848 			goto done;
1849 		}
1850 	}
1851 
1852 	if (event & EV_WRITE) {
1853 		n = msgbuf_write(&ibuf->w);
1854 		if (n == -1 && errno != EAGAIN)
1855 			fatal("msgbuf_write");
1856 		if (n == 0) {
1857 			/* Connection closed. */
1858 			shut = 1;
1859 			goto done;
1860 		}
1861 	}
1862 
1863 	for (;;) {
1864 		const struct got_error *err = NULL;
1865 		struct gotd_client *client = NULL;
1866 		uint32_t client_id = 0;
1867 		int do_disconnect = 0;
1868 
1869 		if ((n = imsg_get(ibuf, &imsg)) == -1)
1870 			fatal("%s: imsg_get error", __func__);
1871 		if (n == 0)	/* No more messages. */
1872 			break;
1873 
1874 		switch (imsg.hdr.type) {
1875 		case GOTD_IMSG_ERROR:
1876 			do_disconnect = 1;
1877 			err = gotd_imsg_recv_error(&client_id, &imsg);
1878 			break;
1879 		case GOTD_IMSG_CONNECT:
1880 			err = recv_connect(&client_id, &imsg);
1881 			break;
1882 		default:
1883 			log_debug("unexpected imsg %d", imsg.hdr.type);
1884 			break;
1885 		}
1886 
1887 		client = find_client(client_id);
1888 		if (client == NULL) {
1889 			log_warnx("%s: client not found", __func__);
1890 			imsg_free(&imsg);
1891 			continue;
1892 		}
1893 
1894 		if (err)
1895 			log_warnx("uid %d: %s", client->euid, err->msg);
1896 
1897 		if (do_disconnect) {
1898 			if (err)
1899 				disconnect_on_error(client, err);
1900 			else
1901 				disconnect(client);
1902 		}
1903 
1904 		imsg_free(&imsg);
1905 	}
1906 done:
1907 	if (!shut) {
1908 		gotd_imsg_event_add(iev);
1909 	} else {
1910 		/* This pipe is dead. Remove its event handler */
1911 		event_del(&iev->ev);
1912 		event_loopexit(NULL);
1913 	}
1914 }
1915 
1916 static void
1917 gotd_dispatch_auth_child(int fd, short event, void *arg)
1918 {
1919 	const struct got_error *err = NULL;
1920 	struct gotd_imsgev *iev = arg;
1921 	struct imsgbuf *ibuf = &iev->ibuf;
1922 	struct gotd_client *client;
1923 	struct gotd_repo *repo = NULL;
1924 	ssize_t n;
1925 	int shut = 0;
1926 	struct imsg imsg;
1927 	uint32_t client_id = 0;
1928 	int do_disconnect = 0;
1929 	enum gotd_procid proc_type;
1930 
1931 	client = find_client_by_proc_fd(fd);
1932 	if (client == NULL)
1933 		fatalx("cannot find client for fd %d", fd);
1934 
1935 	if (client->auth == NULL)
1936 		fatalx("cannot find auth child process for fd %d", fd);
1937 
1938 	if (event & EV_READ) {
1939 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1940 			fatal("imsg_read error");
1941 		if (n == 0) {
1942 			/* Connection closed. */
1943 			shut = 1;
1944 			goto done;
1945 		}
1946 	}
1947 
1948 	if (event & EV_WRITE) {
1949 		n = msgbuf_write(&ibuf->w);
1950 		if (n == -1 && errno != EAGAIN)
1951 			fatal("msgbuf_write");
1952 		if (n == 0) {
1953 			/* Connection closed. */
1954 			shut = 1;
1955 		}
1956 		goto done;
1957 	}
1958 
1959 	if (client->auth->iev.ibuf.fd != fd)
1960 		fatalx("%s: unexpected fd %d", __func__, fd);
1961 
1962 	if ((n = imsg_get(ibuf, &imsg)) == -1)
1963 		fatal("%s: imsg_get error", __func__);
1964 	if (n == 0)	/* No more messages. */
1965 		return;
1966 
1967 	evtimer_del(&client->tmo);
1968 
1969 	switch (imsg.hdr.type) {
1970 	case GOTD_IMSG_ERROR:
1971 		do_disconnect = 1;
1972 		err = gotd_imsg_recv_error(&client_id, &imsg);
1973 		break;
1974 	case GOTD_IMSG_ACCESS_GRANTED:
1975 		break;
1976 	default:
1977 		do_disconnect = 1;
1978 		log_debug("unexpected imsg %d", imsg.hdr.type);
1979 		break;
1980 	}
1981 
1982 	if (!verify_imsg_src(client, client->auth, &imsg)) {
1983 		do_disconnect = 1;
1984 		log_debug("dropping imsg type %d from PID %d",
1985 		    imsg.hdr.type, client->auth->pid);
1986 	}
1987 	imsg_free(&imsg);
1988 
1989 	if (do_disconnect) {
1990 		if (err)
1991 			disconnect_on_error(client, err);
1992 		else
1993 			disconnect(client);
1994 		goto done;
1995 	}
1996 
1997 	repo = find_repo_by_name(client->auth->repo_name);
1998 	if (repo == NULL) {
1999 		err = got_error(GOT_ERR_NOT_GIT_REPO);
2000 		goto done;
2001 	}
2002 	kill_auth_proc(client);
2003 
2004 	log_info("authenticated uid %d for repository %s\n",
2005 	    client->euid, repo->name);
2006 
2007 	if (client->required_auth & GOTD_AUTH_WRITE)
2008 		proc_type = PROC_REPO_WRITE;
2009 	else
2010 		proc_type = PROC_REPO_READ;
2011 
2012 	err = start_repo_child(client, proc_type, repo, gotd.argv0,
2013 	    gotd.confpath, gotd.daemonize, gotd.verbosity);
2014 done:
2015 	if (err)
2016 		log_warnx("uid %d: %s", client->euid, err->msg);
2017 
2018 	/* We might have killed the auth process by now. */
2019 	if (client->auth != NULL) {
2020 		if (!shut) {
2021 			gotd_imsg_event_add(iev);
2022 		} else {
2023 			/* This pipe is dead. Remove its event handler */
2024 			event_del(&iev->ev);
2025 		}
2026 	}
2027 }
2028 
2029 static void
2030 gotd_dispatch_repo_child(int fd, short event, void *arg)
2031 {
2032 	struct gotd_imsgev *iev = arg;
2033 	struct imsgbuf *ibuf = &iev->ibuf;
2034 	struct gotd_child_proc *proc = NULL;
2035 	struct gotd_client *client = NULL;
2036 	ssize_t n;
2037 	int shut = 0;
2038 	struct imsg imsg;
2039 
2040 	if (event & EV_READ) {
2041 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
2042 			fatal("imsg_read error");
2043 		if (n == 0) {
2044 			/* Connection closed. */
2045 			shut = 1;
2046 			goto done;
2047 		}
2048 	}
2049 
2050 	if (event & EV_WRITE) {
2051 		n = msgbuf_write(&ibuf->w);
2052 		if (n == -1 && errno != EAGAIN)
2053 			fatal("msgbuf_write");
2054 		if (n == 0) {
2055 			/* Connection closed. */
2056 			shut = 1;
2057 			goto done;
2058 		}
2059 	}
2060 
2061 	client = find_client_by_proc_fd(fd);
2062 	if (client == NULL)
2063 		fatalx("cannot find client for fd %d", fd);
2064 
2065 	proc = get_client_proc(client);
2066 	if (proc == NULL)
2067 		fatalx("cannot find child process for fd %d", fd);
2068 
2069 	for (;;) {
2070 		const struct got_error *err = NULL;
2071 		uint32_t client_id = 0;
2072 		int do_disconnect = 0;
2073 		int do_list_refs = 0, do_ref_updates = 0, do_ref_update = 0;
2074 		int do_packfile_install = 0;
2075 
2076 		if ((n = imsg_get(ibuf, &imsg)) == -1)
2077 			fatal("%s: imsg_get error", __func__);
2078 		if (n == 0)	/* No more messages. */
2079 			break;
2080 
2081 		switch (imsg.hdr.type) {
2082 		case GOTD_IMSG_ERROR:
2083 			do_disconnect = 1;
2084 			err = gotd_imsg_recv_error(&client_id, &imsg);
2085 			break;
2086 		case GOTD_IMSG_REPO_CHILD_READY:
2087 			do_list_refs = 1;
2088 			break;
2089 		case GOTD_IMSG_PACKFILE_DONE:
2090 			do_disconnect = 1;
2091 			err = recv_packfile_done(&client_id, &imsg);
2092 			break;
2093 		case GOTD_IMSG_PACKFILE_INSTALL:
2094 			err = recv_packfile_install(&client_id, &imsg);
2095 			if (err == NULL)
2096 				do_packfile_install = 1;
2097 			break;
2098 		case GOTD_IMSG_REF_UPDATES_START:
2099 			err = recv_ref_updates_start(&client_id, &imsg);
2100 			if (err == NULL)
2101 				do_ref_updates = 1;
2102 			break;
2103 		case GOTD_IMSG_REF_UPDATE:
2104 			err = recv_ref_update(&client_id, &imsg);
2105 			if (err == NULL)
2106 				do_ref_update = 1;
2107 			break;
2108 		default:
2109 			log_debug("unexpected imsg %d", imsg.hdr.type);
2110 			break;
2111 		}
2112 
2113 		if (!verify_imsg_src(client, proc, &imsg)) {
2114 			log_debug("dropping imsg type %d from PID %d",
2115 			    imsg.hdr.type, proc->pid);
2116 			imsg_free(&imsg);
2117 			continue;
2118 		}
2119 		if (err)
2120 			log_warnx("uid %d: %s", client->euid, err->msg);
2121 
2122 		if (do_disconnect) {
2123 			if (err)
2124 				disconnect_on_error(client, err);
2125 			else
2126 				disconnect(client);
2127 		} else {
2128 			if (do_list_refs)
2129 				err = list_refs_request(client, iev);
2130 			else if (do_packfile_install)
2131 				err = install_pack(client, proc->repo_path,
2132 				    &imsg);
2133 			else if (do_ref_updates)
2134 				err = begin_ref_updates(client, &imsg);
2135 			else if (do_ref_update)
2136 				err = update_ref(client, proc->repo_path,
2137 				    &imsg);
2138 			if (err)
2139 				log_warnx("uid %d: %s", client->euid, err->msg);
2140 		}
2141 		imsg_free(&imsg);
2142 	}
2143 done:
2144 	if (!shut) {
2145 		gotd_imsg_event_add(iev);
2146 	} else {
2147 		/* This pipe is dead. Remove its event handler */
2148 		event_del(&iev->ev);
2149 		event_loopexit(NULL);
2150 	}
2151 }
2152 
2153 static pid_t
2154 start_child(enum gotd_procid proc_id, const char *repo_path,
2155     char *argv0, const char *confpath, int fd, int daemonize, int verbosity)
2156 {
2157 	char	*argv[11];
2158 	int	 argc = 0;
2159 	pid_t	 pid;
2160 
2161 	switch (pid = fork()) {
2162 	case -1:
2163 		fatal("cannot fork");
2164 	case 0:
2165 		break;
2166 	default:
2167 		close(fd);
2168 		return pid;
2169 	}
2170 
2171 	if (fd != GOTD_FILENO_MSG_PIPE) {
2172 		if (dup2(fd, GOTD_FILENO_MSG_PIPE) == -1)
2173 			fatal("cannot setup imsg fd");
2174 	} else if (fcntl(fd, F_SETFD, 0) == -1)
2175 		fatal("cannot setup imsg fd");
2176 
2177 	argv[argc++] = argv0;
2178 	switch (proc_id) {
2179 	case PROC_LISTEN:
2180 		argv[argc++] = (char *)"-L";
2181 		break;
2182 	case PROC_AUTH:
2183 		argv[argc++] = (char *)"-A";
2184 		break;
2185 	case PROC_REPO_READ:
2186 		argv[argc++] = (char *)"-R";
2187 		break;
2188 	case PROC_REPO_WRITE:
2189 		argv[argc++] = (char *)"-W";
2190 		break;
2191 	default:
2192 		fatalx("invalid process id %d", proc_id);
2193 	}
2194 
2195 	argv[argc++] = (char *)"-f";
2196 	argv[argc++] = (char *)confpath;
2197 
2198 	if (repo_path) {
2199 		argv[argc++] = (char *)"-P";
2200 		argv[argc++] = (char *)repo_path;
2201 	}
2202 
2203 	if (!daemonize)
2204 		argv[argc++] = (char *)"-d";
2205 	if (verbosity > 0)
2206 		argv[argc++] = (char *)"-v";
2207 	if (verbosity > 1)
2208 		argv[argc++] = (char *)"-v";
2209 	argv[argc++] = NULL;
2210 
2211 	execvp(argv0, argv);
2212 	fatal("execvp");
2213 }
2214 
2215 static void
2216 start_listener(char *argv0, const char *confpath, int daemonize, int verbosity)
2217 {
2218 	struct gotd_child_proc *proc = &gotd.listen_proc;
2219 
2220 	proc->type = PROC_LISTEN;
2221 
2222 	if (socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK,
2223 	    PF_UNSPEC, proc->pipe) == -1)
2224 		fatal("socketpair");
2225 
2226 	proc->pid = start_child(proc->type, NULL, argv0, confpath,
2227 	    proc->pipe[1], daemonize, verbosity);
2228 	imsg_init(&proc->iev.ibuf, proc->pipe[0]);
2229 	proc->iev.handler = gotd_dispatch_listener;
2230 	proc->iev.events = EV_READ;
2231 	proc->iev.handler_arg = NULL;
2232 }
2233 
2234 static const struct got_error *
2235 start_repo_child(struct gotd_client *client, enum gotd_procid proc_type,
2236     struct gotd_repo *repo, char *argv0, const char *confpath,
2237     int daemonize, int verbosity)
2238 {
2239 	struct gotd_child_proc *proc;
2240 
2241 	if (proc_type != PROC_REPO_READ && proc_type != PROC_REPO_WRITE)
2242 		return got_error_msg(GOT_ERR_NOT_IMPL, "bad process type");
2243 
2244 	proc = calloc(1, sizeof(*proc));
2245 	if (proc == NULL)
2246 		return got_error_from_errno("calloc");
2247 
2248 	proc->type = proc_type;
2249 	if (strlcpy(proc->repo_name, repo->name,
2250 	    sizeof(proc->repo_name)) >= sizeof(proc->repo_name))
2251 		fatalx("repository name too long: %s", repo->name);
2252 	log_debug("starting %s for repository %s",
2253 	    proc->type == PROC_REPO_READ ? "reader" : "writer", repo->name);
2254 	if (realpath(repo->path, proc->repo_path) == NULL)
2255 		fatal("%s", repo->path);
2256 	if (socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK,
2257 	    PF_UNSPEC, proc->pipe) == -1)
2258 		fatal("socketpair");
2259 	proc->pid = start_child(proc->type, proc->repo_path, argv0,
2260 	    confpath, proc->pipe[1], daemonize, verbosity);
2261 	imsg_init(&proc->iev.ibuf, proc->pipe[0]);
2262 	log_debug("proc %s %s is on fd %d",
2263 	    gotd_proc_names[proc->type], proc->repo_path,
2264 	    proc->pipe[0]);
2265 	proc->iev.handler = gotd_dispatch_repo_child;
2266 	proc->iev.events = EV_READ;
2267 	proc->iev.handler_arg = NULL;
2268 	event_set(&proc->iev.ev, proc->iev.ibuf.fd, EV_READ,
2269 	    gotd_dispatch_repo_child, &proc->iev);
2270 	gotd_imsg_event_add(&proc->iev);
2271 
2272 	if (proc->type == PROC_REPO_READ)
2273 		client->repo_read = proc;
2274 	else
2275 		client->repo_write = proc;
2276 
2277 	return NULL;
2278 }
2279 
2280 static const struct got_error *
2281 start_auth_child(struct gotd_client *client, int required_auth,
2282     struct gotd_repo *repo, char *argv0, const char *confpath,
2283     int daemonize, int verbosity)
2284 {
2285 	const struct got_error *err = NULL;
2286 	struct gotd_child_proc *proc;
2287 	struct gotd_imsg_auth iauth;
2288 	int fd;
2289 
2290 	memset(&iauth, 0, sizeof(iauth));
2291 
2292 	fd = dup(client->fd);
2293 	if (fd == -1)
2294 		return got_error_from_errno("dup");
2295 
2296 	proc = calloc(1, sizeof(*proc));
2297 	if (proc == NULL) {
2298 		err = got_error_from_errno("calloc");
2299 		close(fd);
2300 		return err;
2301 	}
2302 
2303 	proc->type = PROC_AUTH;
2304 	if (strlcpy(proc->repo_name, repo->name,
2305 	    sizeof(proc->repo_name)) >= sizeof(proc->repo_name))
2306 		fatalx("repository name too long: %s", repo->name);
2307 	log_debug("starting auth for uid %d repository %s",
2308 	    client->euid, repo->name);
2309 	if (realpath(repo->path, proc->repo_path) == NULL)
2310 		fatal("%s", repo->path);
2311 	if (socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK,
2312 	    PF_UNSPEC, proc->pipe) == -1)
2313 		fatal("socketpair");
2314 	proc->pid = start_child(proc->type, proc->repo_path, argv0,
2315 	    confpath, proc->pipe[1], daemonize, verbosity);
2316 	imsg_init(&proc->iev.ibuf, proc->pipe[0]);
2317 	log_debug("proc %s %s is on fd %d",
2318 	    gotd_proc_names[proc->type], proc->repo_path,
2319 	    proc->pipe[0]);
2320 	proc->iev.handler = gotd_dispatch_auth_child;
2321 	proc->iev.events = EV_READ;
2322 	proc->iev.handler_arg = NULL;
2323 	event_set(&proc->iev.ev, proc->iev.ibuf.fd, EV_READ,
2324 	    gotd_dispatch_auth_child, &proc->iev);
2325 	gotd_imsg_event_add(&proc->iev);
2326 
2327 	iauth.euid = client->euid;
2328 	iauth.egid = client->egid;
2329 	iauth.required_auth = required_auth;
2330 	iauth.client_id = client->id;
2331 	if (gotd_imsg_compose_event(&proc->iev, GOTD_IMSG_AUTHENTICATE,
2332 	    PROC_GOTD, fd, &iauth, sizeof(iauth)) == -1) {
2333 		log_warn("imsg compose AUTHENTICATE");
2334 		close(fd);
2335 		/* Let the auth_timeout handler tidy up. */
2336 	}
2337 
2338 	client->auth = proc;
2339 	client->required_auth = required_auth;
2340 	return NULL;
2341 }
2342 
2343 static void
2344 apply_unveil_repo_readonly(const char *repo_path)
2345 {
2346 	if (unveil(repo_path, "r") == -1)
2347 		fatal("unveil %s", repo_path);
2348 
2349 	if (unveil(NULL, NULL) == -1)
2350 		fatal("unveil");
2351 }
2352 
2353 static void
2354 apply_unveil_none(void)
2355 {
2356 	if (unveil("/", "") == -1)
2357 		fatal("unveil");
2358 
2359 	if (unveil(NULL, NULL) == -1)
2360 		fatal("unveil");
2361 }
2362 
2363 static void
2364 apply_unveil(void)
2365 {
2366 	struct gotd_repo *repo;
2367 
2368 	if (unveil(gotd.argv0, "x") == -1)
2369 		fatal("unveil %s", gotd.argv0);
2370 
2371 	TAILQ_FOREACH(repo, &gotd.repos, entry) {
2372 		if (unveil(repo->path, "rwc") == -1)
2373 			fatal("unveil %s", repo->path);
2374 	}
2375 
2376 	if (unveil(GOT_TMPDIR_STR, "rwc") == -1)
2377 		fatal("unveil %s", GOT_TMPDIR_STR);
2378 
2379 	if (unveil(NULL, NULL) == -1)
2380 		fatal("unveil");
2381 }
2382 
2383 int
2384 main(int argc, char **argv)
2385 {
2386 	const struct got_error *error = NULL;
2387 	int ch, fd = -1, daemonize = 1, verbosity = 0, noaction = 0;
2388 	const char *confpath = GOTD_CONF_PATH;
2389 	char *argv0 = argv[0];
2390 	char title[2048];
2391 	struct passwd *pw = NULL;
2392 	char *repo_path = NULL;
2393 	enum gotd_procid proc_id = PROC_GOTD;
2394 	struct event evsigint, evsigterm, evsighup, evsigusr1;
2395 	int *pack_fds = NULL, *temp_fds = NULL;
2396 
2397 	log_init(1, LOG_DAEMON); /* Log to stderr until daemonized. */
2398 
2399 	while ((ch = getopt(argc, argv, "Adf:LnP:RvW")) != -1) {
2400 		switch (ch) {
2401 		case 'A':
2402 			proc_id = PROC_AUTH;
2403 			break;
2404 		case 'd':
2405 			daemonize = 0;
2406 			break;
2407 		case 'f':
2408 			confpath = optarg;
2409 			break;
2410 		case 'L':
2411 			proc_id = PROC_LISTEN;
2412 			break;
2413 		case 'n':
2414 			noaction = 1;
2415 			break;
2416 		case 'P':
2417 			repo_path = realpath(optarg, NULL);
2418 			if (repo_path == NULL)
2419 				fatal("realpath '%s'", optarg);
2420 			break;
2421 		case 'R':
2422 			proc_id = PROC_REPO_READ;
2423 			break;
2424 		case 'v':
2425 			if (verbosity < 3)
2426 				verbosity++;
2427 			break;
2428 		case 'W':
2429 			proc_id = PROC_REPO_WRITE;
2430 			break;
2431 		default:
2432 			usage();
2433 		}
2434 	}
2435 
2436 	argc -= optind;
2437 	argv += optind;
2438 
2439 	if (argc != 0)
2440 		usage();
2441 
2442 	/* Require an absolute path in argv[0] for reliable re-exec. */
2443 	if (!got_path_is_absolute(argv0))
2444 		fatalx("bad path \"%s\": must be an absolute path", argv0);
2445 
2446 	if (geteuid() && (proc_id == PROC_GOTD || proc_id == PROC_LISTEN))
2447 		fatalx("need root privileges");
2448 
2449 	log_init(daemonize ? 0 : 1, LOG_DAEMON);
2450 	log_setverbose(verbosity);
2451 
2452 	if (parse_config(confpath, proc_id, &gotd) != 0)
2453 		return 1;
2454 
2455 	gotd.argv0 = argv0;
2456 	gotd.daemonize = daemonize;
2457 	gotd.verbosity = verbosity;
2458 	gotd.confpath = confpath;
2459 
2460 	if (proc_id == PROC_GOTD &&
2461 	    (gotd.nrepos == 0 || TAILQ_EMPTY(&gotd.repos)))
2462 		fatalx("no repository defined in configuration file");
2463 
2464 	pw = getpwnam(gotd.user_name);
2465 	if (pw == NULL)
2466 		fatalx("user %s not found", gotd.user_name);
2467 
2468 	if (pw->pw_uid == 0) {
2469 		fatalx("cannot run %s as %s: the user running %s "
2470 		    "must not be the superuser",
2471 		    getprogname(), pw->pw_name, getprogname());
2472 	}
2473 
2474 	if (proc_id == PROC_LISTEN &&
2475 	    !got_path_is_absolute(gotd.unix_socket_path))
2476 		fatalx("bad unix socket path \"%s\": must be an absolute path",
2477 		    gotd.unix_socket_path);
2478 
2479 	if (noaction)
2480 		return 0;
2481 
2482 	if (proc_id == PROC_GOTD) {
2483 		gotd.pid = getpid();
2484 		snprintf(title, sizeof(title), "%s", gotd_proc_names[proc_id]);
2485 		start_listener(argv0, confpath, daemonize, verbosity);
2486 		arc4random_buf(&clients_hash_key, sizeof(clients_hash_key));
2487 		if (daemonize && daemon(1, 0) == -1)
2488 			fatal("daemon");
2489 	} else if (proc_id == PROC_LISTEN) {
2490 		snprintf(title, sizeof(title), "%s", gotd_proc_names[proc_id]);
2491 		if (verbosity) {
2492 			log_info("socket: %s", gotd.unix_socket_path);
2493 			log_info("user: %s", pw->pw_name);
2494 		}
2495 
2496 		fd = unix_socket_listen(gotd.unix_socket_path, pw->pw_uid,
2497 		    pw->pw_gid);
2498 		if (fd == -1) {
2499 			fatal("cannot listen on unix socket %s",
2500 			    gotd.unix_socket_path);
2501 		}
2502 		if (daemonize && daemon(0, 0) == -1)
2503 			fatal("daemon");
2504 	} else if (proc_id == PROC_AUTH) {
2505 		snprintf(title, sizeof(title), "%s %s",
2506 		    gotd_proc_names[proc_id], repo_path);
2507 		if (daemonize && daemon(0, 0) == -1)
2508 			fatal("daemon");
2509 	} else if (proc_id == PROC_REPO_READ || proc_id == PROC_REPO_WRITE) {
2510 		error = got_repo_pack_fds_open(&pack_fds);
2511 		if (error != NULL)
2512 			fatalx("cannot open pack tempfiles: %s", error->msg);
2513 		error = got_repo_temp_fds_open(&temp_fds);
2514 		if (error != NULL)
2515 			fatalx("cannot open pack tempfiles: %s", error->msg);
2516 		if (repo_path == NULL)
2517 			fatalx("repository path not specified");
2518 		snprintf(title, sizeof(title), "%s %s",
2519 		    gotd_proc_names[proc_id], repo_path);
2520 		if (daemonize && daemon(0, 0) == -1)
2521 			fatal("daemon");
2522 	} else
2523 		fatal("invalid process id %d", proc_id);
2524 
2525 	setproctitle("%s", title);
2526 	log_procinit(title);
2527 
2528 	/* Drop root privileges. */
2529 	if (setgid(pw->pw_gid) == -1)
2530 		fatal("setgid %d failed", pw->pw_gid);
2531 	if (setuid(pw->pw_uid) == -1)
2532 		fatal("setuid %d failed", pw->pw_uid);
2533 
2534 	event_init();
2535 
2536 	switch (proc_id) {
2537 	case PROC_GOTD:
2538 #ifndef PROFILE
2539 		if (pledge("stdio rpath wpath cpath proc exec "
2540 		    "sendfd recvfd fattr flock unveil", NULL) == -1)
2541 			err(1, "pledge");
2542 #endif
2543 		break;
2544 	case PROC_LISTEN:
2545 #ifndef PROFILE
2546 		if (pledge("stdio sendfd unix unveil", NULL) == -1)
2547 			err(1, "pledge");
2548 #endif
2549 		/*
2550 		 * Ensure that AF_UNIX bind(2) cannot be used with any other
2551 		 * sockets by revoking all filesystem access via unveil(2).
2552 		 */
2553 		apply_unveil_none();
2554 
2555 		listen_main(title, fd, gotd.connection_limits,
2556 		    gotd.nconnection_limits);
2557 		/* NOTREACHED */
2558 		break;
2559 	case PROC_AUTH:
2560 #ifndef PROFILE
2561 		if (pledge("stdio getpw recvfd unix unveil", NULL) == -1)
2562 			err(1, "pledge");
2563 #endif
2564 		/*
2565 		 * We need the "unix" pledge promise for getpeername(2) only.
2566 		 * Ensure that AF_UNIX bind(2) cannot be used by revoking all
2567 		 * filesystem access via unveil(2). Access to password database
2568 		 * files will still work since "getpw" bypasses unveil(2).
2569 		 */
2570 		apply_unveil_none();
2571 
2572 		auth_main(title, &gotd.repos, repo_path);
2573 		/* NOTREACHED */
2574 		break;
2575 	case PROC_REPO_READ:
2576 #ifndef PROFILE
2577 		if (pledge("stdio rpath recvfd unveil", NULL) == -1)
2578 			err(1, "pledge");
2579 #endif
2580 		apply_unveil_repo_readonly(repo_path);
2581 		repo_read_main(title, repo_path, pack_fds, temp_fds);
2582 		/* NOTREACHED */
2583 		exit(0);
2584 	case PROC_REPO_WRITE:
2585 #ifndef PROFILE
2586 		if (pledge("stdio rpath recvfd unveil", NULL) == -1)
2587 			err(1, "pledge");
2588 #endif
2589 		apply_unveil_repo_readonly(repo_path);
2590 		repo_write_main(title, repo_path, pack_fds, temp_fds);
2591 		/* NOTREACHED */
2592 		exit(0);
2593 	default:
2594 		fatal("invalid process id %d", proc_id);
2595 	}
2596 
2597 	if (proc_id != PROC_GOTD)
2598 		fatal("invalid process id %d", proc_id);
2599 
2600 	apply_unveil();
2601 
2602 	signal_set(&evsigint, SIGINT, gotd_sighdlr, NULL);
2603 	signal_set(&evsigterm, SIGTERM, gotd_sighdlr, NULL);
2604 	signal_set(&evsighup, SIGHUP, gotd_sighdlr, NULL);
2605 	signal_set(&evsigusr1, SIGUSR1, gotd_sighdlr, NULL);
2606 	signal(SIGPIPE, SIG_IGN);
2607 
2608 	signal_add(&evsigint, NULL);
2609 	signal_add(&evsigterm, NULL);
2610 	signal_add(&evsighup, NULL);
2611 	signal_add(&evsigusr1, NULL);
2612 
2613 	gotd_imsg_event_add(&gotd.listen_proc.iev);
2614 
2615 	event_dispatch();
2616 
2617 	if (pack_fds)
2618 		got_repo_pack_fds_close(pack_fds);
2619 	free(repo_path);
2620 	return 0;
2621 }