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Date:: Thu Nov 17 10:16:20 2022 UTC
Message:: fix group membership check in gotd auth ok op@
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1 /*
2  * Copyright (c) 2022 Stefan Sperling <stsp@openbsd.org>
3  * Copyright (c) 2015 Ted Unangst <tedu@openbsd.org>
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 #include <sys/queue.h>
19 #include <sys/tree.h>
20 #include <sys/time.h>
21 #include <sys/types.h>
22 #include <sys/stat.h>
23 #include <sys/socket.h>
24 #include <sys/un.h>
25 #include <sys/wait.h>
26 
27 #include <fcntl.h>
28 #include <err.h>
29 #include <errno.h>
30 #include <event.h>
31 #include <limits.h>
32 #include <pwd.h>
33 #include <grp.h>
34 #include <imsg.h>
35 #include <sha1.h>
36 #include <signal.h>
37 #include <siphash.h>
38 #include <stdarg.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <syslog.h>
43 #include <unistd.h>
44 
45 #include "got_error.h"
46 #include "got_opentemp.h"
47 #include "got_path.h"
48 #include "got_repository.h"
49 #include "got_object.h"
50 #include "got_reference.h"
51 
52 #include "got_lib_delta.h"
53 #include "got_lib_object.h"
54 #include "got_lib_object_cache.h"
55 #include "got_lib_sha1.h"
56 #include "got_lib_gitproto.h"
57 #include "got_lib_pack.h"
58 #include "got_lib_repository.h"
59 
60 #include "gotd.h"
61 #include "log.h"
62 #include "auth.h"
63 #include "repo_read.h"
64 #include "repo_write.h"
65 
66 #ifndef nitems
67 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
68 #endif
69 
70 struct gotd_client {
71 	STAILQ_ENTRY(gotd_client)	 entry;
72 	enum gotd_client_state		 state;
73 	struct gotd_client_capability	*capabilities;
74 	size_t				 ncapa_alloc;
75 	size_t				 ncapabilities;
76 	uint32_t			 id;
77 	int				 fd;
78 	int				 delta_cache_fd;
79 	struct gotd_imsgev		 iev;
80 	struct event			 tmo;
81 	uid_t				 euid;
82 	gid_t				 egid;
83 	struct gotd_child_proc		*repo_read;
84 	struct gotd_child_proc		*repo_write;
85 	char				*packfile_path;
86 	char				*packidx_path;
87 	int				 nref_updates;
88 };
89 STAILQ_HEAD(gotd_clients, gotd_client);
90 
91 static struct gotd_clients gotd_clients[GOTD_CLIENT_TABLE_SIZE];
92 static SIPHASH_KEY clients_hash_key;
93 volatile int client_cnt;
94 static struct timeval timeout = { 3600, 0 };
95 static int inflight;
96 static struct gotd gotd;
97 
98 void gotd_sighdlr(int sig, short event, void *arg);
99 static void gotd_shutdown(void);
100 
101 __dead static void
102 usage()
103 {
104 	fprintf(stderr, "usage: %s [-dv] [-f config-file]\n", getprogname());
105 	exit(1);
106 }
107 
108 static int
109 unix_socket_listen(const char *unix_socket_path, uid_t uid, gid_t gid)
110 {
111 	struct sockaddr_un sun;
112 	int fd = -1;
113 	mode_t old_umask, mode;
114 
115 	fd = socket(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK| SOCK_CLOEXEC, 0);
116 	if (fd == -1) {
117 		log_warn("socket");
118 		return -1;
119 	}
120 
121 	sun.sun_family = AF_UNIX;
122 	if (strlcpy(sun.sun_path, unix_socket_path,
123 	    sizeof(sun.sun_path)) >= sizeof(sun.sun_path)) {
124 		log_warnx("%s: name too long", unix_socket_path);
125 		close(fd);
126 		return -1;
127 	}
128 
129 	if (unlink(unix_socket_path) == -1) {
130 		if (errno != ENOENT) {
131 			log_warn("unlink %s", unix_socket_path);
132 			close(fd);
133 			return -1;
134 		}
135 	}
136 
137 	old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);
138 	mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP;
139 
140 	if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
141 		log_warn("bind: %s", unix_socket_path);
142 		close(fd);
143 		umask(old_umask);
144 		return -1;
145 	}
146 
147 	umask(old_umask);
148 
149 	if (chmod(unix_socket_path, mode) == -1) {
150 		log_warn("chmod %o %s", mode, unix_socket_path);
151 		close(fd);
152 		unlink(unix_socket_path);
153 		return -1;
154 	}
155 
156 	if (chown(unix_socket_path, uid, gid) == -1) {
157 		log_warn("chown %s uid=%d gid=%d", unix_socket_path, uid, gid);
158 		close(fd);
159 		unlink(unix_socket_path);
160 		return -1;
161 	}
162 
163 	if (listen(fd, GOTD_UNIX_SOCKET_BACKLOG) == -1) {
164 		log_warn("listen");
165 		close(fd);
166 		unlink(unix_socket_path);
167 		return -1;
168 	}
169 
170 	return fd;
171 }
172 
173 static struct group *
174 match_group(gid_t *groups, int ngroups, const char *unix_group_name)
175 {
176 	struct group *gr;
177 	int i;
178 
179 	for (i = 0; i < ngroups; i++) {
180 		gr = getgrgid(groups[i]);
181 		if (gr == NULL) {
182 			log_warn("getgrgid %d", groups[i]);
183 			continue;
184 		}
185 		if (strcmp(gr->gr_name, unix_group_name) == 0)
186 			return gr;
187 	}
188 
189 	return NULL;
190 }
191 
192 static int
193 accept_reserve(int fd, struct sockaddr *addr, socklen_t *addrlen,
194     int reserve, volatile int *counter)
195 {
196 	int ret;
197 
198 	if (getdtablecount() + reserve +
199 	    ((*counter + 1) * GOTD_FD_NEEDED) >= getdtablesize()) {
200 		log_debug("inflight fds exceeded");
201 		errno = EMFILE;
202 		return -1;
203 	}
204 
205 	if ((ret = accept4(fd, addr, addrlen,
206 	    SOCK_NONBLOCK | SOCK_CLOEXEC)) > -1) {
207 		(*counter)++;
208 	}
209 
210 	return ret;
211 }
212 
213 static uint64_t
214 client_hash(uint32_t client_id)
215 {
216 	return SipHash24(&clients_hash_key, &client_id, sizeof(client_id));
217 }
218 
219 static void
220 add_client(struct gotd_client *client)
221 {
222 	uint64_t slot = client_hash(client->id) % nitems(gotd_clients);
223 	STAILQ_INSERT_HEAD(&gotd_clients[slot], client, entry);
224 	client_cnt++;
225 }
226 
227 static struct gotd_client *
228 find_client(uint32_t client_id)
229 {
230 	uint64_t slot;
231 	struct gotd_client *c;
232 
233 	slot = client_hash(client_id) % nitems(gotd_clients);
234 	STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
235 		if (c->id == client_id)
236 			return c;
237 	}
238 
239 	return NULL;
240 }
241 
242 static uint32_t
243 get_client_id(void)
244 {
245 	int duplicate = 0;
246 	uint32_t id;
247 
248 	do {
249 		id = arc4random();
250 		duplicate = (find_client(id) != NULL);
251 	} while (duplicate || id == 0);
252 
253 	return id;
254 }
255 
256 static struct gotd_child_proc *
257 get_client_proc(struct gotd_client *client)
258 {
259 	if (client->repo_read && client->repo_write) {
260 		fatalx("uid %d is reading and writing in the same session",
261 		    client->euid);
262 		/* NOTREACHED */
263 	}
264 
265 	if (client->repo_read)
266 		return client->repo_read;
267 	else if (client->repo_write)
268 		return client->repo_write;
269 
270 	return NULL;
271 }
272 
273 static int
274 client_is_reading(struct gotd_client *client)
275 {
276 	return client->repo_read != NULL;
277 }
278 
279 static int
280 client_is_writing(struct gotd_client *client)
281 {
282 	return client->repo_write != NULL;
283 }
284 
285 static const struct got_error *
286 ensure_client_is_reading(struct gotd_client *client)
287 {
288 	if (!client_is_reading(client)) {
289 		return got_error_fmt(GOT_ERR_BAD_PACKET,
290 		    "uid %d made a read-request but is not reading from "
291 		    "a repository", client->euid);
292 	}
293 
294 	return NULL;
295 }
296 
297 static const struct got_error *
298 ensure_client_is_writing(struct gotd_client *client)
299 {
300 	if (!client_is_writing(client)) {
301 		return got_error_fmt(GOT_ERR_BAD_PACKET,
302 		    "uid %d made a write-request but is not writing to "
303 		    "a repository", client->euid);
304 	}
305 
306 	return NULL;
307 }
308 
309 static const struct got_error *
310 ensure_client_is_not_writing(struct gotd_client *client)
311 {
312 	if (client_is_writing(client)) {
313 		return got_error_fmt(GOT_ERR_BAD_PACKET,
314 		    "uid %d made a read-request but is writing to "
315 		    "a repository", client->euid);
316 	}
317 
318 	return NULL;
319 }
320 
321 static const struct got_error *
322 ensure_client_is_not_reading(struct gotd_client *client)
323 {
324 	if (client_is_reading(client)) {
325 		return got_error_fmt(GOT_ERR_BAD_PACKET,
326 		    "uid %d made a write-request but is reading from "
327 		    "a repository", client->euid);
328 	}
329 
330 	return NULL;
331 }
332 
333 static void
334 disconnect(struct gotd_client *client)
335 {
336 	struct gotd_imsg_disconnect idisconnect;
337 	struct gotd_child_proc *proc = get_client_proc(client);
338 	uint64_t slot;
339 
340 	log_debug("uid %d: disconnecting", client->euid);
341 
342 	idisconnect.client_id = client->id;
343 	if (proc) {
344 		if (gotd_imsg_compose_event(&proc->iev,
345 		    GOTD_IMSG_DISCONNECT, PROC_GOTD, -1,
346 		    &idisconnect, sizeof(idisconnect)) == -1)
347 			log_warn("imsg compose DISCONNECT");
348 	}
349 	slot = client_hash(client->id) % nitems(gotd_clients);
350 	STAILQ_REMOVE(&gotd_clients[slot], client, gotd_client, entry);
351 	imsg_clear(&client->iev.ibuf);
352 	event_del(&client->iev.ev);
353 	evtimer_del(&client->tmo);
354 	close(client->fd);
355 	if (client->delta_cache_fd != -1)
356 		close(client->delta_cache_fd);
357 	if (client->packfile_path) {
358 		if (unlink(client->packfile_path) == -1 && errno != ENOENT)
359 			log_warn("unlink %s: ", client->packfile_path);
360 		free(client->packfile_path);
361 	}
362 	if (client->packidx_path) {
363 		if (unlink(client->packidx_path) == -1 && errno != ENOENT)
364 			log_warn("unlink %s: ", client->packidx_path);
365 		free(client->packidx_path);
366 	}
367 	free(client->capabilities);
368 	free(client);
369 	inflight--;
370 	client_cnt--;
371 }
372 
373 static void
374 disconnect_on_error(struct gotd_client *client, const struct got_error *err)
375 {
376 	struct imsgbuf ibuf;
377 
378 	log_warnx("uid %d: %s", client->euid, err->msg);
379 	if (err->code != GOT_ERR_EOF) {
380 		imsg_init(&ibuf, client->fd);
381 		gotd_imsg_send_error(&ibuf, 0, PROC_GOTD, err);
382 		imsg_clear(&ibuf);
383 	}
384 	disconnect(client);
385 }
386 
387 static const struct got_error *
388 send_repo_info(struct gotd_imsgev *iev, struct gotd_repo *repo)
389 {
390 	const struct got_error *err = NULL;
391 	struct gotd_imsg_info_repo irepo;
392 
393 	memset(&irepo, 0, sizeof(irepo));
394 
395 	if (strlcpy(irepo.repo_name, repo->name, sizeof(irepo.repo_name))
396 	    >= sizeof(irepo.repo_name))
397 		return got_error_msg(GOT_ERR_NO_SPACE, "repo name too long");
398 	if (strlcpy(irepo.repo_path, repo->path, sizeof(irepo.repo_path))
399 	    >= sizeof(irepo.repo_path))
400 		return got_error_msg(GOT_ERR_NO_SPACE, "repo path too long");
401 
402 	if (gotd_imsg_compose_event(iev, GOTD_IMSG_INFO_REPO, PROC_GOTD, -1,
403 	    &irepo, sizeof(irepo)) == -1) {
404 		err = got_error_from_errno("imsg compose INFO_REPO");
405 		if (err)
406 			return err;
407 	}
408 
409 	return NULL;
410 }
411 
412 static const struct got_error *
413 send_capability(struct gotd_client_capability *capa, struct gotd_imsgev* iev)
414 {
415 	const struct got_error *err = NULL;
416 	struct gotd_imsg_capability icapa;
417 	size_t len;
418 	struct ibuf *wbuf;
419 
420 	memset(&icapa, 0, sizeof(icapa));
421 
422 	icapa.key_len = strlen(capa->key);
423 	len = sizeof(icapa) + icapa.key_len;
424 	if (capa->value) {
425 		icapa.value_len = strlen(capa->value);
426 		len += icapa.value_len;
427 	}
428 
429 	wbuf = imsg_create(&iev->ibuf, GOTD_IMSG_CAPABILITY, 0, 0, len);
430 	if (wbuf == NULL) {
431 		err = got_error_from_errno("imsg_create CAPABILITY");
432 		return err;
433 	}
434 
435 	if (imsg_add(wbuf, &icapa, sizeof(icapa)) == -1)
436 		return got_error_from_errno("imsg_add CAPABILITY");
437 	if (imsg_add(wbuf, capa->key, icapa.key_len) == -1)
438 		return got_error_from_errno("imsg_add CAPABILITY");
439 	if (capa->value) {
440 		if (imsg_add(wbuf, capa->value, icapa.value_len) == -1)
441 			return got_error_from_errno("imsg_add CAPABILITY");
442 	}
443 
444 	wbuf->fd = -1;
445 	imsg_close(&iev->ibuf, wbuf);
446 
447 	gotd_imsg_event_add(iev);
448 
449 	return NULL;
450 }
451 
452 static const struct got_error *
453 send_client_info(struct gotd_imsgev *iev, struct gotd_client *client)
454 {
455 	const struct got_error *err = NULL;
456 	struct gotd_imsg_info_client iclient;
457 	struct gotd_child_proc *proc;
458 	size_t i;
459 
460 	memset(&iclient, 0, sizeof(iclient));
461 	iclient.euid = client->euid;
462 	iclient.egid = client->egid;
463 
464 	proc = get_client_proc(client);
465 	if (proc) {
466 		if (strlcpy(iclient.repo_name, proc->chroot_path,
467 		    sizeof(iclient.repo_name)) >= sizeof(iclient.repo_name)) {
468 			return got_error_msg(GOT_ERR_NO_SPACE,
469 			    "repo name too long");
470 		}
471 		if (client_is_writing(client))
472 			iclient.is_writing = 1;
473 	}
474 
475 	iclient.state = client->state;
476 	iclient.ncapabilities = client->ncapabilities;
477 
478 	if (gotd_imsg_compose_event(iev, GOTD_IMSG_INFO_CLIENT, PROC_GOTD, -1,
479 	    &iclient, sizeof(iclient)) == -1) {
480 		err = got_error_from_errno("imsg compose INFO_CLIENT");
481 		if (err)
482 			return err;
483 	}
484 
485 	for (i = 0; i < client->ncapabilities; i++) {
486 		struct gotd_client_capability *capa;
487 		capa = &client->capabilities[i];
488 		err = send_capability(capa, iev);
489 		if (err)
490 			return err;
491 	}
492 
493 	return NULL;
494 }
495 
496 static const struct got_error *
497 send_info(struct gotd_client *client)
498 {
499 	const struct got_error *err = NULL;
500 	struct gotd_imsg_info info;
501 	uint64_t slot;
502 	struct gotd_repo *repo;
503 
504 	info.pid = gotd.pid;
505 	info.verbosity = gotd.verbosity;
506 	info.nrepos = gotd.nrepos;
507 	info.nclients = client_cnt - 1;
508 
509 	if (gotd_imsg_compose_event(&client->iev, GOTD_IMSG_INFO, PROC_GOTD, -1,
510 	    &info, sizeof(info)) == -1) {
511 		err = got_error_from_errno("imsg compose INFO");
512 		if (err)
513 			return err;
514 	}
515 
516 	TAILQ_FOREACH(repo, &gotd.repos, entry) {
517 		err = send_repo_info(&client->iev, repo);
518 		if (err)
519 			return err;
520 	}
521 
522 	for (slot = 0; slot < nitems(gotd_clients); slot++) {
523 		struct gotd_client *c;
524 		STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
525 			if (c->id == client->id)
526 				continue;
527 			err = send_client_info(&client->iev, c);
528 			if (err)
529 				return err;
530 		}
531 	}
532 
533 	return NULL;
534 }
535 
536 static const struct got_error *
537 stop_gotd(struct gotd_client *client)
538 {
539 
540 	if (client->euid != 0)
541 		return got_error_set_errno(EPERM, "stop");
542 
543 	gotd_shutdown();
544 	/* NOTREACHED */
545 	return NULL;
546 }
547 
548 static struct gotd_repo *
549 find_repo_by_name(const char *repo_name)
550 {
551 	struct gotd_repo *repo;
552 	size_t namelen;
553 
554 	TAILQ_FOREACH(repo, &gotd.repos, entry) {
555 		namelen = strlen(repo->name);
556 		if (strncmp(repo->name, repo_name, namelen) != 0)
557 			continue;
558 		if (repo_name[namelen] == '\0' ||
559 		    strcmp(&repo_name[namelen], ".git") == 0)
560 			return repo;
561 	}
562 
563 	return NULL;
564 }
565 
566 static struct gotd_child_proc *
567 find_proc_by_repo_name(enum gotd_procid proc_id, const char *repo_name)
568 {
569 	struct gotd_child_proc *proc;
570 	int i;
571 	size_t namelen;
572 
573 	for (i = 0; i < gotd.nprocs; i++) {
574 		proc = &gotd.procs[i];
575 		if (proc->type != proc_id)
576 			continue;
577 		namelen = strlen(proc->repo_name);
578 		if (strncmp(proc->repo_name, repo_name, namelen) != 0)
579 			continue;
580 		if (repo_name[namelen] == '\0' ||
581 		    strcmp(&repo_name[namelen], ".git") == 0)
582 			return proc;
583 	}
584 
585 	return NULL;
586 }
587 
588 static struct gotd_child_proc *
589 find_proc_by_fd(int fd)
590 {
591 	struct gotd_child_proc *proc;
592 	int i;
593 
594 	for (i = 0; i < gotd.nprocs; i++) {
595 		proc = &gotd.procs[i];
596 		if (proc->iev.ibuf.fd == fd)
597 			return proc;
598 	}
599 
600 	return NULL;
601 }
602 
603 static const struct got_error *
604 forward_list_refs_request(struct gotd_client *client, struct imsg *imsg)
605 {
606 	const struct got_error *err;
607 	struct gotd_imsg_list_refs ireq;
608 	struct gotd_imsg_list_refs_internal ilref;
609 	struct gotd_repo *repo = NULL;
610 	struct gotd_child_proc *proc = NULL;
611 	size_t datalen;
612 	int fd = -1;
613 
614 	log_debug("list-refs request from uid %d", client->euid);
615 
616 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
617 	if (datalen != sizeof(ireq))
618 		return got_error(GOT_ERR_PRIVSEP_LEN);
619 
620 	memcpy(&ireq, imsg->data, datalen);
621 
622 	memset(&ilref, 0, sizeof(ilref));
623 	ilref.client_id = client->id;
624 
625 	if (ireq.client_is_reading) {
626 		err = ensure_client_is_not_writing(client);
627 		if (err)
628 			return err;
629 		repo = find_repo_by_name(ireq.repo_name);
630 		if (repo == NULL)
631 			return got_error(GOT_ERR_NOT_GIT_REPO);
632 		err = gotd_auth_check(&repo->rules, repo->name,
633 		    client->euid, client->egid, GOTD_AUTH_READ);
634 		if (err)
635 			return err;
636 		client->repo_read = find_proc_by_repo_name(PROC_REPO_READ,
637 		    ireq.repo_name);
638 		if (client->repo_read == NULL)
639 			return got_error(GOT_ERR_NOT_GIT_REPO);
640 	} else {
641 		err = ensure_client_is_not_reading(client);
642 		if (err)
643 			return err;
644 		repo = find_repo_by_name(ireq.repo_name);
645 		if (repo == NULL)
646 			return got_error(GOT_ERR_NOT_GIT_REPO);
647 		err = gotd_auth_check(&repo->rules, repo->name, client->euid,
648 		    client->egid, GOTD_AUTH_READ | GOTD_AUTH_WRITE);
649 		if (err)
650 			return err;
651 		client->repo_write = find_proc_by_repo_name(PROC_REPO_WRITE,
652 		    ireq.repo_name);
653 		if (client->repo_write == NULL)
654 			return got_error(GOT_ERR_NOT_GIT_REPO);
655 	}
656 
657 	fd = dup(client->fd);
658 	if (fd == -1)
659 		return got_error_from_errno("dup");
660 
661 	proc = get_client_proc(client);
662 	if (proc == NULL)
663 		fatalx("no process found for uid %d", client->euid);
664 	if (gotd_imsg_compose_event(&proc->iev,
665 	    GOTD_IMSG_LIST_REFS_INTERNAL, PROC_GOTD, fd,
666 	    &ilref, sizeof(ilref)) == -1) {
667 		err = got_error_from_errno("imsg compose WANT");
668 		close(fd);
669 		return err;
670 	}
671 
672 	return NULL;
673 }
674 
675 static const struct got_error *
676 forward_want(struct gotd_client *client, struct imsg *imsg)
677 {
678 	struct gotd_imsg_want ireq;
679 	struct gotd_imsg_want iwant;
680 	size_t datalen;
681 
682 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
683 	if (datalen != sizeof(ireq))
684 		return got_error(GOT_ERR_PRIVSEP_LEN);
685 
686 	memcpy(&ireq, imsg->data, datalen);
687 
688 	memset(&iwant, 0, sizeof(iwant));
689 	memcpy(iwant.object_id, ireq.object_id, SHA1_DIGEST_LENGTH);
690 	iwant.client_id = client->id;
691 
692 	if (gotd_imsg_compose_event(&client->repo_read->iev, GOTD_IMSG_WANT,
693 	    PROC_GOTD, -1, &iwant, sizeof(iwant)) == -1)
694 		return got_error_from_errno("imsg compose WANT");
695 
696 	return NULL;
697 }
698 
699 static const struct got_error *
700 forward_ref_update(struct gotd_client *client, struct imsg *imsg)
701 {
702 	const struct got_error *err = NULL;
703 	struct gotd_imsg_ref_update ireq;
704 	struct gotd_imsg_ref_update *iref = NULL;
705 	size_t datalen;
706 
707 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
708 	if (datalen < sizeof(ireq))
709 		return got_error(GOT_ERR_PRIVSEP_LEN);
710 	memcpy(&ireq, imsg->data, sizeof(ireq));
711 	if (datalen != sizeof(ireq) + ireq.name_len)
712 		return got_error(GOT_ERR_PRIVSEP_LEN);
713 
714 	iref = malloc(datalen);
715 	if (iref == NULL)
716 		return got_error_from_errno("malloc");
717 	memcpy(iref, imsg->data, datalen);
718 
719 	iref->client_id = client->id;
720 	if (gotd_imsg_compose_event(&client->repo_write->iev,
721 	    GOTD_IMSG_REF_UPDATE, PROC_GOTD, -1, iref, datalen) == -1)
722 		err = got_error_from_errno("imsg compose REF_UPDATE");
723 	free(iref);
724 	return err;
725 }
726 
727 static const struct got_error *
728 forward_have(struct gotd_client *client, struct imsg *imsg)
729 {
730 	struct gotd_imsg_have ireq;
731 	struct gotd_imsg_have ihave;
732 	size_t datalen;
733 
734 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
735 	if (datalen != sizeof(ireq))
736 		return got_error(GOT_ERR_PRIVSEP_LEN);
737 
738 	memcpy(&ireq, imsg->data, datalen);
739 
740 	memset(&ihave, 0, sizeof(ihave));
741 	memcpy(ihave.object_id, ireq.object_id, SHA1_DIGEST_LENGTH);
742 	ihave.client_id = client->id;
743 
744 	if (gotd_imsg_compose_event(&client->repo_read->iev, GOTD_IMSG_HAVE,
745 	    PROC_GOTD, -1, &ihave, sizeof(ihave)) == -1)
746 		return got_error_from_errno("imsg compose HAVE");
747 
748 	return NULL;
749 }
750 
751 static int
752 client_has_capability(struct gotd_client *client, const char *capastr)
753 {
754 	struct gotd_client_capability *capa;
755 	size_t i;
756 
757 	if (client->ncapabilities == 0)
758 		return 0;
759 
760 	for (i = 0; i < client->ncapabilities; i++) {
761 		capa = &client->capabilities[i];
762 		if (strcmp(capa->key, capastr) == 0)
763 			return 1;
764 	}
765 
766 	return 0;
767 }
768 
769 static const struct got_error *
770 recv_capabilities(struct gotd_client *client, struct imsg *imsg)
771 {
772 	struct gotd_imsg_capabilities icapas;
773 	size_t datalen;
774 
775 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
776 	if (datalen != sizeof(icapas))
777 		return got_error(GOT_ERR_PRIVSEP_LEN);
778 	memcpy(&icapas, imsg->data, sizeof(icapas));
779 
780 	client->ncapa_alloc = icapas.ncapabilities;
781 	client->capabilities = calloc(client->ncapa_alloc,
782 	    sizeof(*client->capabilities));
783 	if (client->capabilities == NULL) {
784 		client->ncapa_alloc = 0;
785 		return got_error_from_errno("calloc");
786 	}
787 
788 	log_debug("expecting %zu capabilities from uid %d",
789 	    client->ncapa_alloc, client->euid);
790 	return NULL;
791 }
792 
793 static const struct got_error *
794 recv_capability(struct gotd_client *client, struct imsg *imsg)
795 {
796 	struct gotd_imsg_capability icapa;
797 	struct gotd_client_capability *capa;
798 	size_t datalen;
799 	char *key, *value = NULL;
800 
801 	if (client->capabilities == NULL ||
802 	    client->ncapabilities >= client->ncapa_alloc) {
803 		return got_error_msg(GOT_ERR_BAD_REQUEST,
804 		    "unexpected capability received");
805 	}
806 
807 	memset(&icapa, 0, sizeof(icapa));
808 
809 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
810 	if (datalen < sizeof(icapa))
811 		return got_error(GOT_ERR_PRIVSEP_LEN);
812 	memcpy(&icapa, imsg->data, sizeof(icapa));
813 
814 	if (datalen != sizeof(icapa) + icapa.key_len + icapa.value_len)
815 		return got_error(GOT_ERR_PRIVSEP_LEN);
816 
817 	key = malloc(icapa.key_len + 1);
818 	if (key == NULL)
819 		return got_error_from_errno("malloc");
820 	if (icapa.value_len > 0) {
821 		value = malloc(icapa.value_len + 1);
822 		if (value == NULL) {
823 			free(key);
824 			return got_error_from_errno("malloc");
825 		}
826 	}
827 
828 	memcpy(key, imsg->data + sizeof(icapa), icapa.key_len);
829 	key[icapa.key_len] = '\0';
830 	if (value) {
831 		memcpy(value, imsg->data + sizeof(icapa) + icapa.key_len,
832 		    icapa.value_len);
833 		value[icapa.value_len] = '\0';
834 	}
835 
836 	capa = &client->capabilities[client->ncapabilities++];
837 	capa->key = key;
838 	capa->value = value;
839 
840 	if (value)
841 		log_debug("uid %d: capability %s=%s", client->euid, key, value);
842 	else
843 		log_debug("uid %d: capability %s", client->euid, key);
844 
845 	return NULL;
846 }
847 
848 static const struct got_error *
849 send_packfile(struct gotd_client *client)
850 {
851 	const struct got_error *err = NULL;
852 	struct gotd_imsg_send_packfile ipack;
853 	struct gotd_imsg_packfile_pipe ipipe;
854 	int pipe[2];
855 
856 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe) == -1)
857 		return got_error_from_errno("socketpair");
858 
859 	memset(&ipack, 0, sizeof(ipack));
860 	memset(&ipipe, 0, sizeof(ipipe));
861 
862 	ipack.client_id = client->id;
863 	if (client_has_capability(client, GOT_CAPA_SIDE_BAND_64K))
864 		ipack.report_progress = 1;
865 
866 	client->delta_cache_fd = got_opentempfd();
867 	if (client->delta_cache_fd == -1)
868 		return got_error_from_errno("got_opentempfd");
869 
870 	if (gotd_imsg_compose_event(&client->repo_read->iev,
871 	    GOTD_IMSG_SEND_PACKFILE, PROC_GOTD, client->delta_cache_fd,
872 	    &ipack, sizeof(ipack)) == -1) {
873 		err = got_error_from_errno("imsg compose SEND_PACKFILE");
874 		close(pipe[0]);
875 		close(pipe[1]);
876 		return err;
877 	}
878 
879 	ipipe.client_id = client->id;
880 
881 	/* Send pack pipe end 0 to repo_read. */
882 	if (gotd_imsg_compose_event(&client->repo_read->iev,
883 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[0],
884 	        &ipipe, sizeof(ipipe)) == -1) {
885 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
886 		close(pipe[1]);
887 		return err;
888 	}
889 
890 	/* Send pack pipe end 1 to gotsh(1) (expects just an fd, no data). */
891 	if (gotd_imsg_compose_event(&client->iev,
892 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[1], NULL, 0) == -1)
893 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
894 
895 	return err;
896 }
897 
898 static const struct got_error *
899 recv_packfile(struct gotd_client *client)
900 {
901 	const struct got_error *err = NULL;
902 	struct gotd_imsg_recv_packfile ipack;
903 	struct gotd_imsg_packfile_pipe ipipe;
904 	struct gotd_imsg_packidx_file ifile;
905 	char *basepath = NULL, *pack_path = NULL, *idx_path = NULL;
906 	int packfd = -1, idxfd = -1;
907 	int pipe[2] = { -1, -1 };
908 
909 	if (client->packfile_path) {
910 		return got_error_fmt(GOT_ERR_PRIVSEP_MSG,
911 		    "uid %d already has a pack file", client->euid);
912 	}
913 
914 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe) == -1)
915 		return got_error_from_errno("socketpair");
916 
917 	memset(&ipipe, 0, sizeof(ipipe));
918 	ipipe.client_id = client->id;
919 
920 	/* Send pack pipe end 0 to repo_write. */
921 	if (gotd_imsg_compose_event(&client->repo_write->iev,
922 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[0],
923 	        &ipipe, sizeof(ipipe)) == -1) {
924 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
925 		pipe[0] = -1;
926 		goto done;
927 	}
928 	pipe[0] = -1;
929 
930 	/* Send pack pipe end 1 to gotsh(1) (expects just an fd, no data). */
931 	if (gotd_imsg_compose_event(&client->iev,
932 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[1], NULL, 0) == -1)
933 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
934 	pipe[1] = -1;
935 
936 	if (asprintf(&basepath, "%s/%s/receiving-from-uid-%d.pack",
937 	    client->repo_write->chroot_path, GOT_OBJECTS_PACK_DIR,
938 	    client->euid) == -1) {
939 		err = got_error_from_errno("asprintf");
940 		goto done;
941 	}
942 
943 	err = got_opentemp_named_fd(&pack_path, &packfd, basepath, "");
944 	if (err)
945 		goto done;
946 
947 	free(basepath);
948 	if (asprintf(&basepath, "%s/%s/receiving-from-uid-%d.idx",
949 	    client->repo_write->chroot_path, GOT_OBJECTS_PACK_DIR,
950 	    client->euid) == -1) {
951 		err = got_error_from_errno("asprintf");
952 		basepath = NULL;
953 		goto done;
954 	}
955 	err = got_opentemp_named_fd(&idx_path, &idxfd, basepath, "");
956 	if (err)
957 		goto done;
958 
959 	memset(&ifile, 0, sizeof(ifile));
960 	ifile.client_id = client->id;
961 	if (gotd_imsg_compose_event(&client->repo_write->iev,
962 	    GOTD_IMSG_PACKIDX_FILE, PROC_GOTD, idxfd,
963 	    &ifile, sizeof(ifile)) == -1) {
964 		err = got_error_from_errno("imsg compose PACKIDX_FILE");
965 		idxfd = -1;
966 		goto done;
967 	}
968 	idxfd = -1;
969 
970 	memset(&ipack, 0, sizeof(ipack));
971 	ipack.client_id = client->id;
972 	if (client_has_capability(client, GOT_CAPA_REPORT_STATUS))
973 		ipack.report_status = 1;
974 
975 	if (gotd_imsg_compose_event(&client->repo_write->iev,
976 	    GOTD_IMSG_RECV_PACKFILE, PROC_GOTD, packfd,
977 	    &ipack, sizeof(ipack)) == -1) {
978 		err = got_error_from_errno("imsg compose RECV_PACKFILE");
979 		packfd = -1;
980 		goto done;
981 	}
982 	packfd = -1;
983 
984 done:
985 	free(basepath);
986 	if (pipe[0] != -1 && close(pipe[0]) == -1 && err == NULL)
987 		err = got_error_from_errno("close");
988 	if (pipe[1] != -1 && close(pipe[1]) == -1 && err == NULL)
989 		err = got_error_from_errno("close");
990 	if (packfd != -1 && close(packfd) == -1 && err == NULL)
991 		err = got_error_from_errno("close");
992 	if (idxfd != -1 && close(idxfd) == -1 && err == NULL)
993 		err = got_error_from_errno("close");
994 	if (err) {
995 		free(pack_path);
996 		free(idx_path);
997 	} else {
998 		client->packfile_path = pack_path;
999 		client->packidx_path = idx_path;
1000 	}
1001 	return err;
1002 }
1003 
1004 static void
1005 gotd_request(int fd, short events, void *arg)
1006 {
1007 	struct gotd_imsgev *iev = arg;
1008 	struct imsgbuf *ibuf = &iev->ibuf;
1009 	struct gotd_client *client = iev->handler_arg;
1010 	const struct got_error *err = NULL;
1011 	struct imsg imsg;
1012 	ssize_t n;
1013 
1014 	if (events & EV_WRITE) {
1015 		while (ibuf->w.queued) {
1016 			n = msgbuf_write(&ibuf->w);
1017 			if (n == -1 && errno == EPIPE) {
1018 				/*
1019 				 * The client has closed its socket.
1020 				 * This can happen when Git clients are
1021 				 * done sending pack file data.
1022 				*/
1023 				msgbuf_clear(&ibuf->w);
1024 				continue;
1025 			} else if (n == -1 && errno != EAGAIN) {
1026 				err = got_error_from_errno("imsg_flush");
1027 				disconnect_on_error(client, err);
1028 				return;
1029 			}
1030 			if (n == 0) {
1031 				/* Connection closed. */
1032 				err = got_error(GOT_ERR_EOF);
1033 				disconnect_on_error(client, err);
1034 				return;
1035 			}
1036 		}
1037 
1038 		/* Disconnect gotctl(8) now that messages have been sent. */
1039 		if (!client_is_reading(client) && !client_is_writing(client)) {
1040 			disconnect(client);
1041 			return;
1042 		}
1043 	}
1044 
1045 	if ((events & EV_READ) == 0)
1046 		return;
1047 
1048 	memset(&imsg, 0, sizeof(imsg));
1049 
1050 	while (err == NULL) {
1051 		err = gotd_imsg_recv(&imsg, ibuf, 0);
1052 		if (err) {
1053 			if (err->code == GOT_ERR_PRIVSEP_READ)
1054 				err = NULL;
1055 			break;
1056 		}
1057 
1058 		evtimer_del(&client->tmo);
1059 
1060 		switch (imsg.hdr.type) {
1061 		case GOTD_IMSG_INFO:
1062 			err = send_info(client);
1063 			break;
1064 		case GOTD_IMSG_STOP:
1065 			err = stop_gotd(client);
1066 			break;
1067 		case GOTD_IMSG_LIST_REFS:
1068 			if (client->state != GOTD_STATE_EXPECT_LIST_REFS) {
1069 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1070 				    "unexpected list-refs request received");
1071 				break;
1072 			}
1073 			err = forward_list_refs_request(client, &imsg);
1074 			if (err)
1075 				break;
1076 			client->state = GOTD_STATE_EXPECT_CAPABILITIES;
1077 			log_debug("uid %d: expecting capabilities",
1078 			    client->euid);
1079 			break;
1080 		case GOTD_IMSG_CAPABILITIES:
1081 			if (client->state != GOTD_STATE_EXPECT_CAPABILITIES) {
1082 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1083 				    "unexpected capabilities received");
1084 				break;
1085 			}
1086 			log_debug("receiving capabilities from uid %d",
1087 			    client->euid);
1088 			err = recv_capabilities(client, &imsg);
1089 			break;
1090 		case GOTD_IMSG_CAPABILITY:
1091 			if (client->state != GOTD_STATE_EXPECT_CAPABILITIES) {
1092 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1093 				    "unexpected capability received");
1094 				break;
1095 			}
1096 			err = recv_capability(client, &imsg);
1097 			if (err || client->ncapabilities < client->ncapa_alloc)
1098 				break;
1099 			if (client_is_reading(client)) {
1100 				client->state = GOTD_STATE_EXPECT_WANT;
1101 				log_debug("uid %d: expecting want-lines",
1102 				    client->euid);
1103 			} else if (client_is_writing(client)) {
1104 				client->state = GOTD_STATE_EXPECT_REF_UPDATE;
1105 				log_debug("uid %d: expecting ref-update-lines",
1106 				    client->euid);
1107 			} else
1108 				fatalx("client %d is both reading and writing",
1109 				    client->euid);
1110 			break;
1111 		case GOTD_IMSG_WANT:
1112 			if (client->state != GOTD_STATE_EXPECT_WANT) {
1113 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1114 				    "unexpected want-line received");
1115 				break;
1116 			}
1117 			log_debug("received want-line from uid %d",
1118 			    client->euid);
1119 			err = ensure_client_is_reading(client);
1120 			if (err)
1121 				break;
1122 			err = forward_want(client, &imsg);
1123 			break;
1124 		case GOTD_IMSG_REF_UPDATE:
1125 			if (client->state != GOTD_STATE_EXPECT_REF_UPDATE) {
1126 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1127 				    "unexpected ref-update-line received");
1128 				break;
1129 			}
1130 			log_debug("received ref-update-line from uid %d",
1131 			    client->euid);
1132 			err = ensure_client_is_writing(client);
1133 			if (err)
1134 				break;
1135 			err = forward_ref_update(client, &imsg);
1136 			if (err)
1137 				break;
1138 			client->state = GOTD_STATE_EXPECT_MORE_REF_UPDATES;
1139 			break;
1140 		case GOTD_IMSG_HAVE:
1141 			if (client->state != GOTD_STATE_EXPECT_HAVE) {
1142 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1143 				    "unexpected have-line received");
1144 				break;
1145 			}
1146 			log_debug("received have-line from uid %d",
1147 			    client->euid);
1148 			err = ensure_client_is_reading(client);
1149 			if (err)
1150 				break;
1151 			err = forward_have(client, &imsg);
1152 			if (err)
1153 				break;
1154 			break;
1155 		case GOTD_IMSG_FLUSH:
1156 			if (client->state == GOTD_STATE_EXPECT_WANT ||
1157 			    client->state == GOTD_STATE_EXPECT_HAVE) {
1158 				err = ensure_client_is_reading(client);
1159 				if (err)
1160 					break;
1161 			} else if (client->state ==
1162 			    GOTD_STATE_EXPECT_MORE_REF_UPDATES) {
1163 				err = ensure_client_is_writing(client);
1164 				if (err)
1165 					break;
1166 			} else {
1167 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1168 				    "unexpected flush-pkt received");
1169 				break;
1170 			}
1171 			log_debug("received flush-pkt from uid %d",
1172 			    client->euid);
1173 			if (client->state == GOTD_STATE_EXPECT_WANT) {
1174 				client->state = GOTD_STATE_EXPECT_HAVE;
1175 				log_debug("uid %d: expecting have-lines",
1176 				    client->euid);
1177 			} else if (client->state == GOTD_STATE_EXPECT_HAVE) {
1178 				client->state = GOTD_STATE_EXPECT_DONE;
1179 				log_debug("uid %d: expecting 'done'",
1180 				    client->euid);
1181 			} else if (client->state ==
1182 			    GOTD_STATE_EXPECT_MORE_REF_UPDATES) {
1183 				client->state = GOTD_STATE_EXPECT_PACKFILE;
1184 				log_debug("uid %d: expecting packfile",
1185 				    client->euid);
1186 				err = recv_packfile(client);
1187 			} else {
1188 				/* should not happen, see above */
1189 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1190 				    "unexpected client state");
1191 				break;
1192 			}
1193 			break;
1194 		case GOTD_IMSG_DONE:
1195 			if (client->state != GOTD_STATE_EXPECT_HAVE &&
1196 			    client->state != GOTD_STATE_EXPECT_DONE) {
1197 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1198 				    "unexpected flush-pkt received");
1199 				break;
1200 			}
1201 			log_debug("received 'done' from uid %d", client->euid);
1202 			err = ensure_client_is_reading(client);
1203 			if (err)
1204 				break;
1205 			client->state = GOTD_STATE_DONE;
1206 			err = send_packfile(client);
1207 			break;
1208 		default:
1209 			err = got_error(GOT_ERR_PRIVSEP_MSG);
1210 			break;
1211 		}
1212 
1213 		imsg_free(&imsg);
1214 	}
1215 
1216 	if (err) {
1217 		if (err->code != GOT_ERR_EOF ||
1218 		    client->state != GOTD_STATE_EXPECT_PACKFILE)
1219 			disconnect_on_error(client, err);
1220 	} else {
1221 		gotd_imsg_event_add(&client->iev);
1222 		evtimer_add(&client->tmo, &timeout);
1223 	}
1224 }
1225 
1226 static void
1227 gotd_request_timeout(int fd, short events, void *arg)
1228 {
1229 	struct gotd_client *client = arg;
1230 
1231 	log_debug("disconnecting uid %d due to timeout", client->euid);
1232 	disconnect(client);
1233 }
1234 
1235 static void
1236 gotd_accept(int fd, short event, void *arg)
1237 {
1238 	struct sockaddr_storage ss;
1239 	struct timeval backoff;
1240 	socklen_t len;
1241 	int s = -1;
1242 	struct gotd_client *client = NULL;
1243 	uid_t euid;
1244 	gid_t egid;
1245 
1246 	backoff.tv_sec = 1;
1247 	backoff.tv_usec = 0;
1248 
1249 	if (event_add(&gotd.ev, NULL) == -1) {
1250 		log_warn("event_add");
1251 		return;
1252 	}
1253 	if (event & EV_TIMEOUT)
1254 		return;
1255 
1256 	len = sizeof(ss);
1257 
1258 	s = accept_reserve(fd, (struct sockaddr *)&ss, &len, GOTD_FD_RESERVE,
1259 	    &inflight);
1260 
1261 	if (s == -1) {
1262 		switch (errno) {
1263 		case EINTR:
1264 		case EWOULDBLOCK:
1265 		case ECONNABORTED:
1266 			return;
1267 		case EMFILE:
1268 		case ENFILE:
1269 			event_del(&gotd.ev);
1270 			evtimer_add(&gotd.pause, &backoff);
1271 			return;
1272 		default:
1273 			log_warn("%s: accept", __func__);
1274 			return;
1275 		}
1276 	}
1277 
1278 	if (client_cnt >= GOTD_MAXCLIENTS)
1279 		goto err;
1280 
1281 	if (getpeereid(s, &euid, &egid) == -1) {
1282 		log_warn("%s: getpeereid", __func__);
1283 		goto err;
1284 	}
1285 
1286 	client = calloc(1, sizeof(*client));
1287 	if (client == NULL) {
1288 		log_warn("%s: calloc", __func__);
1289 		goto err;
1290 	}
1291 
1292 	client->state = GOTD_STATE_EXPECT_LIST_REFS;
1293 	client->id = get_client_id();
1294 	client->fd = s;
1295 	s = -1;
1296 	client->delta_cache_fd = -1;
1297 	client->euid = euid;
1298 	client->egid = egid;
1299 	client->nref_updates = -1;
1300 
1301 	imsg_init(&client->iev.ibuf, client->fd);
1302 	client->iev.handler = gotd_request;
1303 	client->iev.events = EV_READ;
1304 	client->iev.handler_arg = client;
1305 
1306 	event_set(&client->iev.ev, client->fd, EV_READ, gotd_request,
1307 	    &client->iev);
1308 	gotd_imsg_event_add(&client->iev);
1309 
1310 	evtimer_set(&client->tmo, gotd_request_timeout, client);
1311 
1312 	add_client(client);
1313 	log_debug("%s: new client uid %d connected on fd %d", __func__,
1314 	    client->euid, client->fd);
1315 	return;
1316 err:
1317 	inflight--;
1318 	if (s != -1)
1319 		close(s);
1320 	free(client);
1321 }
1322 
1323 static void
1324 gotd_accept_paused(int fd, short event, void *arg)
1325 {
1326 	event_add(&gotd.ev, NULL);
1327 }
1328 
1329 static const char *gotd_proc_names[PROC_MAX] = {
1330 	"parent",
1331 	"repo_read",
1332 	"repo_write"
1333 };
1334 
1335 static struct gotd_child_proc *
1336 get_proc_for_pid(pid_t pid)
1337 {
1338 	struct gotd_child_proc *proc;
1339 	int i;
1340 
1341 	for (i = 0; i < gotd.nprocs; i++) {
1342 		proc = &gotd.procs[i];
1343 		if (proc->pid == pid)
1344 			return proc;
1345 	}
1346 
1347 	return NULL;
1348 }
1349 
1350 static void
1351 kill_proc(struct gotd_child_proc *proc, int fatal)
1352 {
1353 	if (fatal) {
1354 		log_warnx("sending SIGKILL to PID %d", proc->pid);
1355 		kill(proc->pid, SIGKILL);
1356 	} else
1357 		kill(proc->pid, SIGTERM);
1358 }
1359 
1360 static void
1361 gotd_shutdown(void)
1362 {
1363 	pid_t	 pid;
1364 	int	 status, i;
1365 	struct gotd_child_proc *proc;
1366 
1367 	for (i = 0; i < gotd.nprocs; i++) {
1368 		proc = &gotd.procs[i];
1369 		msgbuf_clear(&proc->iev.ibuf.w);
1370 		close(proc->iev.ibuf.fd);
1371 		kill_proc(proc, 0);
1372 	}
1373 
1374 	log_debug("waiting for children to terminate");
1375 	do {
1376 		pid = wait(&status);
1377 		if (pid == -1) {
1378 			if (errno != EINTR && errno != ECHILD)
1379 				fatal("wait");
1380 		} else if (WIFSIGNALED(status)) {
1381 			proc = get_proc_for_pid(pid);
1382 			log_warnx("%s %s child process terminated; signal %d",
1383 			    proc ? gotd_proc_names[proc->type] : "",
1384 			    proc ? proc->chroot_path : "", WTERMSIG(status));
1385 		}	
1386 	} while (pid != -1 || (pid == -1 && errno == EINTR));
1387 
1388 	log_info("terminating");
1389 	exit(0);
1390 }
1391 
1392 void
1393 gotd_sighdlr(int sig, short event, void *arg)
1394 {
1395 	/*
1396 	 * Normal signal handler rules don't apply because libevent
1397 	 * decouples for us.
1398 	 */
1399 
1400 	switch (sig) {
1401 	case SIGHUP:
1402 		log_info("%s: ignoring SIGHUP", __func__);
1403 		break;
1404 	case SIGUSR1:
1405 		log_info("%s: ignoring SIGUSR1", __func__);
1406 		break;
1407 	case SIGTERM:
1408 	case SIGINT:
1409 		gotd_shutdown();
1410 		log_warnx("gotd terminating");
1411 		exit(0);
1412 		break;
1413 	default:
1414 		fatalx("unexpected signal");
1415 	}
1416 }
1417 
1418 static const struct got_error *
1419 ensure_proc_is_reading(struct gotd_client *client,
1420     struct gotd_child_proc *proc)
1421 {
1422 	if (!client_is_reading(client)) {
1423 		kill_proc(proc, 1);
1424 		return got_error_fmt(GOT_ERR_BAD_PACKET,
1425 		    "PID %d handled a read-request for uid %d but this "
1426 		    "user is not reading from a repository", proc->pid,
1427 		    client->euid);
1428 	}
1429 
1430 	return NULL;
1431 }
1432 
1433 static const struct got_error *
1434 ensure_proc_is_writing(struct gotd_client *client,
1435     struct gotd_child_proc *proc)
1436 {
1437 	if (!client_is_writing(client)) {
1438 		kill_proc(proc, 1);
1439 		return got_error_fmt(GOT_ERR_BAD_PACKET,
1440 		    "PID %d handled a write-request for uid %d but this "
1441 		    "user is not writing to a repository", proc->pid,
1442 		    client->euid);
1443 	}
1444 
1445 	return NULL;
1446 }
1447 
1448 static int
1449 verify_imsg_src(struct gotd_client *client, struct gotd_child_proc *proc,
1450     struct imsg *imsg)
1451 {
1452 	const struct got_error *err;
1453 	struct gotd_child_proc *client_proc;
1454 	int ret = 0;
1455 
1456 	client_proc = get_client_proc(client);
1457 	if (client_proc == NULL)
1458 		fatalx("no process found for uid %d", client->euid);
1459 
1460 	if (proc->pid != client_proc->pid) {
1461 		kill_proc(proc, 1);
1462 		log_warnx("received message from PID %d for uid %d, while "
1463 		    "PID %d is the process serving this user",
1464 		    proc->pid, client->euid, client_proc->pid);
1465 		return 0;
1466 	}
1467 
1468 	switch (imsg->hdr.type) {
1469 	case GOTD_IMSG_ERROR:
1470 		ret = 1;
1471 		break;
1472 	case GOTD_IMSG_PACKFILE_DONE:
1473 		err = ensure_proc_is_reading(client, proc);
1474 		if (err)
1475 			log_warnx("uid %d: %s", client->euid, err->msg);
1476 		else
1477 			ret = 1;
1478 		break;
1479 	case GOTD_IMSG_PACKFILE_INSTALL:
1480 	case GOTD_IMSG_REF_UPDATES_START:
1481 	case GOTD_IMSG_REF_UPDATE:
1482 		err = ensure_proc_is_writing(client, proc);
1483 		if (err)
1484 			log_warnx("uid %d: %s", client->euid, err->msg);
1485 		else
1486 			ret = 1;
1487 		break;
1488 	default:
1489 		log_debug("%s: unexpected imsg %d", __func__, imsg->hdr.type);
1490 		break;
1491 	}
1492 
1493 	return ret;
1494 }
1495 
1496 static const struct got_error *
1497 recv_packfile_done(uint32_t *client_id, struct imsg *imsg)
1498 {
1499 	struct gotd_imsg_packfile_done idone;
1500 	size_t datalen;
1501 
1502 	log_debug("packfile-done received");
1503 
1504 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1505 	if (datalen != sizeof(idone))
1506 		return got_error(GOT_ERR_PRIVSEP_LEN);
1507 	memcpy(&idone, imsg->data, sizeof(idone));
1508 
1509 	*client_id = idone.client_id;
1510 	return NULL;
1511 }
1512 
1513 static const struct got_error *
1514 recv_packfile_install(uint32_t *client_id, struct imsg *imsg)
1515 {
1516 	struct gotd_imsg_packfile_install inst;
1517 	size_t datalen;
1518 
1519 	log_debug("packfile-install received");
1520 
1521 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1522 	if (datalen != sizeof(inst))
1523 		return got_error(GOT_ERR_PRIVSEP_LEN);
1524 	memcpy(&inst, imsg->data, sizeof(inst));
1525 
1526 	*client_id = inst.client_id;
1527 	return NULL;
1528 }
1529 
1530 static const struct got_error *
1531 recv_ref_updates_start(uint32_t *client_id, struct imsg *imsg)
1532 {
1533 	struct gotd_imsg_ref_updates_start istart;
1534 	size_t datalen;
1535 
1536 	log_debug("ref-updates-start received");
1537 
1538 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1539 	if (datalen != sizeof(istart))
1540 		return got_error(GOT_ERR_PRIVSEP_LEN);
1541 	memcpy(&istart, imsg->data, sizeof(istart));
1542 
1543 	*client_id = istart.client_id;
1544 	return NULL;
1545 }
1546 
1547 static const struct got_error *
1548 recv_ref_update(uint32_t *client_id, struct imsg *imsg)
1549 {
1550 	struct gotd_imsg_ref_update iref;
1551 	size_t datalen;
1552 
1553 	log_debug("ref-update received");
1554 
1555 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1556 	if (datalen < sizeof(iref))
1557 		return got_error(GOT_ERR_PRIVSEP_LEN);
1558 	memcpy(&iref, imsg->data, sizeof(iref));
1559 
1560 	*client_id = iref.client_id;
1561 	return NULL;
1562 }
1563 
1564 static const struct got_error *
1565 send_ref_update_ok(struct gotd_client *client,
1566     struct gotd_imsg_ref_update *iref, const char *refname)
1567 {
1568 	struct gotd_imsg_ref_update_ok iok;
1569 	struct ibuf *wbuf;
1570 	size_t len;
1571 
1572 	memset(&iok, 0, sizeof(iok));
1573 	iok.client_id = client->id;
1574 	memcpy(iok.old_id, iref->old_id, SHA1_DIGEST_LENGTH);
1575 	memcpy(iok.new_id, iref->new_id, SHA1_DIGEST_LENGTH);
1576 	iok.name_len = strlen(refname);
1577 
1578 	len = sizeof(iok) + iok.name_len;
1579 	wbuf = imsg_create(&client->iev.ibuf, GOTD_IMSG_REF_UPDATE_OK,
1580 	    PROC_GOTD, gotd.pid, len);
1581 	if (wbuf == NULL)
1582 		return got_error_from_errno("imsg_create REF_UPDATE_OK");
1583 
1584 	if (imsg_add(wbuf, &iok, sizeof(iok)) == -1)
1585 		return got_error_from_errno("imsg_add REF_UPDATE_OK");
1586 	if (imsg_add(wbuf, refname, iok.name_len) == -1)
1587 		return got_error_from_errno("imsg_add REF_UPDATE_OK");
1588 
1589 	wbuf->fd = -1;
1590 	imsg_close(&client->iev.ibuf, wbuf);
1591 	gotd_imsg_event_add(&client->iev);
1592 	return NULL;
1593 }
1594 
1595 static void
1596 send_refs_updated(struct gotd_client *client)
1597 {
1598 	if (gotd_imsg_compose_event(&client->iev,
1599 	    GOTD_IMSG_REFS_UPDATED, PROC_GOTD, -1, NULL, 0) == -1)
1600 		log_warn("imsg compose REFS_UPDATED");
1601 }
1602 
1603 static const struct got_error *
1604 send_ref_update_ng(struct gotd_client *client,
1605     struct gotd_imsg_ref_update *iref, const char *refname,
1606     const char *reason)
1607 {
1608 	const struct got_error *ng_err;
1609 	struct gotd_imsg_ref_update_ng ing;
1610 	struct ibuf *wbuf;
1611 	size_t len;
1612 
1613 	memset(&ing, 0, sizeof(ing));
1614 	ing.client_id = client->id;
1615 	memcpy(ing.old_id, iref->old_id, SHA1_DIGEST_LENGTH);
1616 	memcpy(ing.new_id, iref->new_id, SHA1_DIGEST_LENGTH);
1617 	ing.name_len = strlen(refname);
1618 
1619 	ng_err = got_error_fmt(GOT_ERR_REF_BUSY, "%s", reason);
1620 	ing.reason_len = strlen(ng_err->msg);
1621 
1622 	len = sizeof(ing) + ing.name_len + ing.reason_len;
1623 	wbuf = imsg_create(&client->iev.ibuf, GOTD_IMSG_REF_UPDATE_NG,
1624 	    PROC_GOTD, gotd.pid, len);
1625 	if (wbuf == NULL)
1626 		return got_error_from_errno("imsg_create REF_UPDATE_NG");
1627 
1628 	if (imsg_add(wbuf, &ing, sizeof(ing)) == -1)
1629 		return got_error_from_errno("imsg_add REF_UPDATE_NG");
1630 	if (imsg_add(wbuf, refname, ing.name_len) == -1)
1631 		return got_error_from_errno("imsg_add REF_UPDATE_NG");
1632 	if (imsg_add(wbuf, ng_err->msg, ing.reason_len) == -1)
1633 		return got_error_from_errno("imsg_add REF_UPDATE_NG");
1634 
1635 	wbuf->fd = -1;
1636 	imsg_close(&client->iev.ibuf, wbuf);
1637 	gotd_imsg_event_add(&client->iev);
1638 	return NULL;
1639 }
1640 
1641 static const struct got_error *
1642 install_pack(struct gotd_client *client, const char *repo_path,
1643     struct imsg *imsg)
1644 {
1645 	const struct got_error *err = NULL;
1646 	struct gotd_imsg_packfile_install inst;
1647 	char hex[SHA1_DIGEST_STRING_LENGTH];
1648 	size_t datalen;
1649 	char *packfile_path = NULL, *packidx_path = NULL;
1650 
1651 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1652 	if (datalen != sizeof(inst))
1653 		return got_error(GOT_ERR_PRIVSEP_LEN);
1654 	memcpy(&inst, imsg->data, sizeof(inst));
1655 
1656 	if (client->packfile_path == NULL)
1657 		return got_error_msg(GOT_ERR_BAD_REQUEST,
1658 		    "client has no pack file");
1659 	if (client->packidx_path == NULL)
1660 		return got_error_msg(GOT_ERR_BAD_REQUEST,
1661 		    "client has no pack file index");
1662 
1663 	if (got_sha1_digest_to_str(inst.pack_sha1, hex, sizeof(hex)) == NULL)
1664 		return got_error_msg(GOT_ERR_NO_SPACE,
1665 		    "could not convert pack file SHA1 to hex");
1666 
1667 	if (asprintf(&packfile_path, "/%s/%s/pack-%s.pack",
1668 	    repo_path, GOT_OBJECTS_PACK_DIR, hex) == -1) {
1669 		err = got_error_from_errno("asprintf");
1670 		goto done;
1671 	}
1672 
1673 	if (asprintf(&packidx_path, "/%s/%s/pack-%s.idx",
1674 	    repo_path, GOT_OBJECTS_PACK_DIR, hex) == -1) {
1675 		err = got_error_from_errno("asprintf");
1676 		goto done;
1677 	}
1678 
1679 	if (rename(client->packfile_path, packfile_path) == -1) {
1680 		err = got_error_from_errno3("rename", client->packfile_path,
1681 		    packfile_path);
1682 		goto done;
1683 	}
1684 
1685 	free(client->packfile_path);
1686 	client->packfile_path = NULL;
1687 
1688 	if (rename(client->packidx_path, packidx_path) == -1) {
1689 		err = got_error_from_errno3("rename", client->packidx_path,
1690 		    packidx_path);
1691 		goto done;
1692 	}
1693 
1694 	free(client->packidx_path);
1695 	client->packidx_path = NULL;
1696 done:
1697 	free(packfile_path);
1698 	free(packidx_path);
1699 	return err;
1700 }
1701 
1702 static const struct got_error *
1703 begin_ref_updates(struct gotd_client *client, struct imsg *imsg)
1704 {
1705 	struct gotd_imsg_ref_updates_start istart;
1706 	size_t datalen;
1707 
1708 	if (client->nref_updates != -1)
1709 		return got_error(GOT_ERR_PRIVSEP_MSG);
1710 
1711 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1712 	if (datalen != sizeof(istart))
1713 		return got_error(GOT_ERR_PRIVSEP_LEN);
1714 	memcpy(&istart, imsg->data, sizeof(istart));
1715 
1716 	if (istart.nref_updates <= 0)
1717 		return got_error(GOT_ERR_PRIVSEP_MSG);
1718 
1719 	client->nref_updates = istart.nref_updates;
1720 	return NULL;
1721 }
1722 
1723 static const struct got_error *
1724 update_ref(struct gotd_client *client, const char *repo_path,
1725     struct imsg *imsg)
1726 {
1727 	const struct got_error *err = NULL;
1728 	struct got_repository *repo = NULL;
1729 	struct got_reference *ref = NULL;
1730 	struct gotd_imsg_ref_update iref;
1731 	struct got_object_id old_id, new_id;
1732 	struct got_object_id *id = NULL;
1733 	struct got_object *obj = NULL;
1734 	char *refname = NULL;
1735 	size_t datalen;
1736 	int locked = 0;
1737 
1738 	log_debug("update-ref from uid %d", client->euid);
1739 
1740 	if (client->nref_updates <= 0)
1741 		return got_error(GOT_ERR_PRIVSEP_MSG);
1742 
1743 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1744 	if (datalen < sizeof(iref))
1745 		return got_error(GOT_ERR_PRIVSEP_LEN);
1746 	memcpy(&iref, imsg->data, sizeof(iref));
1747 	if (datalen != sizeof(iref) + iref.name_len)
1748 		return got_error(GOT_ERR_PRIVSEP_LEN);
1749 	refname = malloc(iref.name_len + 1);
1750 	if (refname == NULL)
1751 		return got_error_from_errno("malloc");
1752 	memcpy(refname, imsg->data + sizeof(iref), iref.name_len);
1753 	refname[iref.name_len] = '\0';
1754 
1755 	log_debug("updating ref %s for uid %d", refname, client->euid);
1756 
1757 	err = got_repo_open(&repo, repo_path, NULL, NULL);
1758 	if (err)
1759 		goto done;
1760 
1761 	memcpy(old_id.sha1, iref.old_id, SHA1_DIGEST_LENGTH);
1762 	memcpy(new_id.sha1, iref.new_id, SHA1_DIGEST_LENGTH);
1763 	err = got_object_open(&obj, repo, &new_id);
1764 	if (err)
1765 		goto done;
1766 
1767 	if (iref.ref_is_new) {
1768 		err = got_ref_open(&ref, repo, refname, 0);
1769 		if (err) {
1770 			if (err->code != GOT_ERR_NOT_REF)
1771 				goto done;
1772 			err = got_ref_alloc(&ref, refname, &new_id);
1773 			if (err)
1774 				goto done;
1775 			err = got_ref_write(ref, repo); /* will lock/unlock */
1776 			if (err)
1777 				goto done;
1778 		} else {
1779 			err = got_error_fmt(GOT_ERR_REF_BUSY,
1780 			    "%s has been created by someone else "
1781 			    "while transaction was in progress",
1782 			    got_ref_get_name(ref));
1783 			goto done;
1784 		}
1785 	} else {
1786 		err = got_ref_open(&ref, repo, refname, 1 /* lock */);
1787 		if (err)
1788 			goto done;
1789 		locked = 1;
1790 
1791 		err = got_ref_resolve(&id, repo, ref);
1792 		if (err)
1793 			goto done;
1794 
1795 		if (got_object_id_cmp(id, &old_id) != 0) {
1796 			err = got_error_fmt(GOT_ERR_REF_BUSY,
1797 			    "%s has been modified by someone else "
1798 			    "while transaction was in progress",
1799 			    got_ref_get_name(ref));
1800 			goto done;
1801 		}
1802 
1803 		err = got_ref_change_ref(ref, &new_id);
1804 		if (err)
1805 			goto done;
1806 
1807 		err = got_ref_write(ref, repo);
1808 		if (err)
1809 			goto done;
1810 
1811 		free(id);
1812 		id = NULL;
1813 	}
1814 done:
1815 	if (err) {
1816 		if (err->code == GOT_ERR_LOCKFILE_TIMEOUT) {
1817 			err = got_error_fmt(GOT_ERR_LOCKFILE_TIMEOUT,
1818 			    "could not acquire exclusive file lock for %s",
1819 			    refname);
1820 		}
1821 		send_ref_update_ng(client, &iref, refname, err->msg);
1822 	} else
1823 		send_ref_update_ok(client, &iref, refname);
1824 
1825 	if (client->nref_updates > 0) {
1826 		client->nref_updates--;
1827 		if (client->nref_updates == 0)
1828 			send_refs_updated(client);
1829 
1830 	}
1831 	if (locked) {
1832 		const struct got_error *unlock_err;
1833 		unlock_err = got_ref_unlock(ref);
1834 		if (unlock_err && err == NULL)
1835 			err = unlock_err;
1836 	}
1837 	if (ref)
1838 		got_ref_close(ref);
1839 	if (obj)
1840 		got_object_close(obj);
1841 	if (repo)
1842 		got_repo_close(repo);
1843 	free(refname);
1844 	free(id);
1845 	return err;
1846 }
1847 
1848 static void
1849 gotd_dispatch(int fd, short event, void *arg)
1850 {
1851 	struct gotd_imsgev *iev = arg;
1852 	struct imsgbuf *ibuf = &iev->ibuf;
1853 	struct gotd_child_proc *proc = NULL;
1854 	ssize_t n;
1855 	int shut = 0;
1856 	struct imsg imsg;
1857 
1858 	if (event & EV_READ) {
1859 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1860 			fatal("imsg_read error");
1861 		if (n == 0) {
1862 			/* Connection closed. */
1863 			shut = 1;
1864 			goto done;
1865 		}
1866 	}
1867 
1868 	if (event & EV_WRITE) {
1869 		n = msgbuf_write(&ibuf->w);
1870 		if (n == -1 && errno != EAGAIN)
1871 			fatal("msgbuf_write");
1872 		if (n == 0) {
1873 			/* Connection closed. */
1874 			shut = 1;
1875 			goto done;
1876 		}
1877 	}
1878 
1879 	proc = find_proc_by_fd(fd);
1880 	if (proc == NULL)
1881 		fatalx("cannot find child process for fd %d", fd);
1882 
1883 	for (;;) {
1884 		const struct got_error *err = NULL;
1885 		struct gotd_client *client = NULL;
1886 		uint32_t client_id = 0;
1887 		int do_disconnect = 0;
1888 		int do_ref_updates = 0, do_ref_update = 0;
1889 		int do_packfile_install = 0;
1890 
1891 		if ((n = imsg_get(ibuf, &imsg)) == -1)
1892 			fatal("%s: imsg_get error", __func__);
1893 		if (n == 0)	/* No more messages. */
1894 			break;
1895 
1896 		switch (imsg.hdr.type) {
1897 		case GOTD_IMSG_ERROR:
1898 			do_disconnect = 1;
1899 			err = gotd_imsg_recv_error(&client_id, &imsg);
1900 			break;
1901 		case GOTD_IMSG_PACKFILE_DONE:
1902 			do_disconnect = 1;
1903 			err = recv_packfile_done(&client_id, &imsg);
1904 			break;
1905 		case GOTD_IMSG_PACKFILE_INSTALL:
1906 			err = recv_packfile_install(&client_id, &imsg);
1907 			if (err == NULL)
1908 				do_packfile_install = 1;
1909 			break;
1910 		case GOTD_IMSG_REF_UPDATES_START:
1911 			err = recv_ref_updates_start(&client_id, &imsg);
1912 			if (err == NULL)
1913 				do_ref_updates = 1;
1914 			break;
1915 		case GOTD_IMSG_REF_UPDATE:
1916 			err = recv_ref_update(&client_id, &imsg);
1917 			if (err == NULL)
1918 				do_ref_update = 1;
1919 			break;
1920 		default:
1921 			log_debug("unexpected imsg %d", imsg.hdr.type);
1922 			break;
1923 		}
1924 
1925 		client = find_client(client_id);
1926 		if (client == NULL) {
1927 			log_warnx("%s: client not found", __func__);
1928 			imsg_free(&imsg);
1929 			continue;
1930 		}
1931 
1932 		if (!verify_imsg_src(client, proc, &imsg)) {
1933 			log_debug("dropping imsg type %d from PID %d",
1934 			    imsg.hdr.type, proc->pid);
1935 			imsg_free(&imsg);
1936 			continue;
1937 		}
1938 		if (err)
1939 			log_warnx("uid %d: %s", client->euid, err->msg);
1940 
1941 		if (do_disconnect) {
1942 			if (err)
1943 				disconnect_on_error(client, err);
1944 			else
1945 				disconnect(client);
1946 		} else {
1947 			if (do_packfile_install)
1948 				err = install_pack(client, proc->chroot_path,
1949 				    &imsg);
1950 			else if (do_ref_updates)
1951 				err = begin_ref_updates(client, &imsg);
1952 			else if (do_ref_update)
1953 				err = update_ref(client, proc->chroot_path,
1954 				    &imsg);
1955 			if (err)
1956 				log_warnx("uid %d: %s", client->euid, err->msg);
1957 		}
1958 		imsg_free(&imsg);
1959 	}
1960 done:
1961 	if (!shut) {
1962 		gotd_imsg_event_add(iev);
1963 	} else {
1964 		/* This pipe is dead. Remove its event handler */
1965 		event_del(&iev->ev);
1966 		event_loopexit(NULL);
1967 	}
1968 }
1969 
1970 static pid_t
1971 start_child(enum gotd_procid proc_id, const char *chroot_path,
1972     char *argv0, const char *confpath, int fd, int daemonize, int verbosity)
1973 {
1974 	char	*argv[11];
1975 	int	 argc = 0;
1976 	pid_t	 pid;
1977 
1978 	switch (pid = fork()) {
1979 	case -1:
1980 		fatal("cannot fork");
1981 	case 0:
1982 		break;
1983 	default:
1984 		close(fd);
1985 		return pid;
1986 	}
1987 
1988 	if (fd != GOTD_SOCK_FILENO) {
1989 		if (dup2(fd, GOTD_SOCK_FILENO) == -1)
1990 			fatal("cannot setup imsg fd");
1991 	} else if (fcntl(fd, F_SETFD, 0) == -1)
1992 		fatal("cannot setup imsg fd");
1993 
1994 	argv[argc++] = argv0;
1995 	switch (proc_id) {
1996 	case PROC_REPO_READ:
1997 		argv[argc++] = (char *)"-R";
1998 		break;
1999 	case PROC_REPO_WRITE:
2000 		argv[argc++] = (char *)"-W";
2001 		break;
2002 	default:
2003 		fatalx("invalid process id %d", proc_id);
2004 	}
2005 
2006 	argv[argc++] = (char *)"-f";
2007 	argv[argc++] = (char *)confpath;
2008 
2009 	argv[argc++] = (char *)"-P";
2010 	argv[argc++] = (char *)chroot_path;
2011 
2012 	if (!daemonize)
2013 		argv[argc++] = (char *)"-d";
2014 	if (verbosity > 0)
2015 		argv[argc++] = (char *)"-v";
2016 	if (verbosity > 1)
2017 		argv[argc++] = (char *)"-v";
2018 	argv[argc++] = NULL;
2019 
2020 	execvp(argv0, argv);
2021 	fatal("execvp");
2022 }
2023 
2024 static void
2025 start_repo_children(struct gotd *gotd, char *argv0, const char *confpath,
2026     int daemonize, int verbosity)
2027 {
2028 	struct gotd_repo *repo = NULL;
2029 	struct gotd_child_proc *proc;
2030 	int i;
2031 
2032 	/*
2033 	 * XXX For now, use one reader and one writer per repository.
2034 	 * This should be changed to N readers + M writers.
2035 	 */
2036 	gotd->nprocs = gotd->nrepos * 2;
2037 	gotd->procs = calloc(gotd->nprocs, sizeof(*gotd->procs));
2038 	if (gotd->procs == NULL)
2039 		fatal("calloc");
2040 	for (i = 0; i < gotd->nprocs; i++) {
2041 		if (repo == NULL)
2042 			repo = TAILQ_FIRST(&gotd->repos);
2043 		proc = &gotd->procs[i];
2044 		if (i < gotd->nrepos)
2045 			proc->type = PROC_REPO_READ;
2046 		else
2047 			proc->type = PROC_REPO_WRITE;
2048 		if (strlcpy(proc->repo_name, repo->name,
2049 		    sizeof(proc->repo_name)) >= sizeof(proc->repo_name))
2050 			fatalx("repository name too long: %s", repo->name);
2051 		log_debug("adding repository %s", repo->name);
2052 		if (realpath(repo->path, proc->chroot_path) == NULL)
2053 			fatal("%s", repo->path);
2054 		if (socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK,
2055 		    PF_UNSPEC, proc->pipe) == -1)
2056 			fatal("socketpair");
2057 		proc->pid = start_child(proc->type, proc->chroot_path, argv0,
2058 		    confpath, proc->pipe[1], daemonize, verbosity);
2059 		imsg_init(&proc->iev.ibuf, proc->pipe[0]);
2060 		log_debug("proc %s %s is on fd %d",
2061 		    gotd_proc_names[proc->type], proc->chroot_path,
2062 		    proc->pipe[0]);
2063 		proc->iev.handler = gotd_dispatch;
2064 		proc->iev.events = EV_READ;
2065 		proc->iev.handler_arg = NULL;
2066 		event_set(&proc->iev.ev, proc->iev.ibuf.fd, EV_READ,
2067 		    gotd_dispatch, &proc->iev);
2068 
2069 		repo = TAILQ_NEXT(repo, entry);
2070 	}
2071 }
2072 
2073 static void
2074 apply_unveil(void)
2075 {
2076 	struct gotd_repo *repo;
2077 
2078 	TAILQ_FOREACH(repo, &gotd.repos, entry) {
2079 		if (unveil(repo->path, "rwc") == -1)
2080 			fatal("unveil %s", repo->path);
2081 	}
2082 
2083 	if (unveil(GOT_TMPDIR_STR, "rwc") == -1)
2084 		fatal("unveil %s", GOT_TMPDIR_STR);
2085 
2086 	if (unveil(NULL, NULL) == -1)
2087 		fatal("unveil");
2088 }
2089 
2090 int
2091 main(int argc, char **argv)
2092 {
2093 	const struct got_error *error = NULL;
2094 	int ch, fd = -1, daemonize = 1, verbosity = 0, noaction = 0;
2095 	const char *confpath = GOTD_CONF_PATH;
2096 	char *argv0 = argv[0];
2097 	char title[2048];
2098 	gid_t groups[NGROUPS_MAX];
2099 	int ngroups = NGROUPS_MAX;
2100 	struct passwd *pw = NULL;
2101 	struct group *gr = NULL;
2102 	char *repo_path = NULL;
2103 	enum gotd_procid proc_id = PROC_GOTD;
2104 	struct event evsigint, evsigterm, evsighup, evsigusr1;
2105 	int *pack_fds = NULL, *temp_fds = NULL;
2106 
2107 	log_init(1, LOG_DAEMON); /* Log to stderr until daemonized. */
2108 
2109 	while ((ch = getopt(argc, argv, "df:nP:RvW")) != -1) {
2110 		switch (ch) {
2111 		case 'd':
2112 			daemonize = 0;
2113 			break;
2114 		case 'f':
2115 			confpath = optarg;
2116 			break;
2117 		case 'n':
2118 			noaction = 1;
2119 			break;
2120 		case 'P':
2121 			repo_path = realpath(optarg, NULL);
2122 			if (repo_path == NULL)
2123 				fatal("realpath '%s'", optarg);
2124 			break;
2125 		case 'R':
2126 			proc_id = PROC_REPO_READ;
2127 			break;
2128 		case 'v':
2129 			if (verbosity < 3)
2130 				verbosity++;
2131 			break;
2132 		case 'W':
2133 			proc_id = PROC_REPO_WRITE;
2134 			break;
2135 		default:
2136 			usage();
2137 		}
2138 	}
2139 
2140 	argc -= optind;
2141 	argv += optind;
2142 
2143 	if (argc != 0)
2144 		usage();
2145 
2146 	if (geteuid())
2147 		fatalx("need root privileges");
2148 
2149 	log_init(daemonize ? 0 : 1, LOG_DAEMON);
2150 	log_setverbose(verbosity);
2151 
2152 	if (parse_config(confpath, proc_id, &gotd) != 0)
2153 		return 1;
2154 
2155 	if (proc_id == PROC_GOTD &&
2156 	    (gotd.nrepos == 0 || TAILQ_EMPTY(&gotd.repos)))
2157 		fatalx("no repository defined in configuration file");
2158 
2159 	pw = getpwnam(gotd.user_name);
2160 	if (pw == NULL)
2161 		fatal("getpwuid: user %s not found", gotd.user_name);
2162 
2163 	if (pw->pw_uid == 0) {
2164 		fatalx("cannot run %s as %s: the user running %s "
2165 		    "must not be the superuser",
2166 		    getprogname(), pw->pw_name, getprogname());
2167 	}
2168 
2169 	if (getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups) == -1)
2170 		log_warnx("group membership list truncated");
2171 
2172 	gr = match_group(groups, ngroups, gotd.unix_group_name);
2173 	if (gr == NULL) {
2174 		fatalx("cannot start %s: the user running %s "
2175 		    "must be a secondary member of group %s",
2176 		    getprogname(), getprogname(), gotd.unix_group_name);
2177 	}
2178 	if (gr->gr_gid == pw->pw_gid) {
2179 		fatalx("cannot start %s: the user running %s "
2180 		    "must be a secondary member of group %s, but "
2181 		    "%s is the user's primary group",
2182 		    getprogname(), getprogname(), gotd.unix_group_name,
2183 		    gotd.unix_group_name);
2184 	}
2185 
2186 	if (proc_id == PROC_GOTD &&
2187 	    !got_path_is_absolute(gotd.unix_socket_path))
2188 		fatalx("bad unix socket path \"%s\": must be an absolute path",
2189 		    gotd.unix_socket_path);
2190 
2191 	if (noaction)
2192 		return 0;
2193 
2194 	if (proc_id == PROC_GOTD && verbosity) {
2195 		log_info("socket: %s", gotd.unix_socket_path);
2196 		log_info("user: %s", pw->pw_name);
2197 		log_info("secondary group: %s", gr->gr_name);
2198 
2199 		fd = unix_socket_listen(gotd.unix_socket_path, pw->pw_uid,
2200 		    gr->gr_gid);
2201 		if (fd == -1) {
2202 			fatal("cannot listen on unix socket %s",
2203 			    gotd.unix_socket_path);
2204 		}
2205 	}
2206 
2207 	if (proc_id == PROC_GOTD) {
2208 		gotd.pid = getpid();
2209 		snprintf(title, sizeof(title), "%s", gotd_proc_names[proc_id]);
2210 		start_repo_children(&gotd, argv0, confpath, daemonize,
2211 		    verbosity);
2212 		arc4random_buf(&clients_hash_key, sizeof(clients_hash_key));
2213 		if (daemonize && daemon(0, 0) == -1)
2214 			fatal("daemon");
2215 	} else if (proc_id == PROC_REPO_READ || proc_id == PROC_REPO_WRITE) {
2216 		error = got_repo_pack_fds_open(&pack_fds);
2217 		if (error != NULL)
2218 			fatalx("cannot open pack tempfiles: %s", error->msg);
2219 		error = got_repo_temp_fds_open(&temp_fds);
2220 		if (error != NULL)
2221 			fatalx("cannot open pack tempfiles: %s", error->msg);
2222 		if (repo_path == NULL)
2223 			fatalx("repository path not specified");
2224 		snprintf(title, sizeof(title), "%s %s",
2225 		    gotd_proc_names[proc_id], repo_path);
2226 		if (chroot(repo_path) == -1)
2227 			fatal("chroot");
2228 		if (chdir("/") == -1)
2229 			fatal("chdir(\"/\")");
2230 		if (daemonize && daemon(1, 0) == -1)
2231 			fatal("daemon");
2232 	} else
2233 		fatal("invalid process id %d", proc_id);
2234 
2235 	setproctitle("%s", title);
2236 	log_procinit(title);
2237 
2238 	/* Drop root privileges. */
2239 	if (setgid(pw->pw_gid) == -1)
2240 		fatal("setgid %d failed", pw->pw_gid);
2241 	if (setuid(pw->pw_uid) == -1)
2242 		fatal("setuid %d failed", pw->pw_uid);
2243 
2244 	event_init();
2245 
2246 	switch (proc_id) {
2247 	case PROC_GOTD:
2248 #ifndef PROFILE
2249 		if (pledge("stdio rpath wpath cpath proc getpw sendfd recvfd "
2250 		    "fattr flock unix unveil", NULL) == -1)
2251 			err(1, "pledge");
2252 #endif
2253 		break;
2254 	case PROC_REPO_READ:
2255 #ifndef PROFILE
2256 		if (pledge("stdio rpath recvfd", NULL) == -1)
2257 			err(1, "pledge");
2258 #endif
2259 		repo_read_main(title, pack_fds, temp_fds);
2260 		/* NOTREACHED */
2261 		exit(0);
2262 	case PROC_REPO_WRITE:
2263 #ifndef PROFILE
2264 		if (pledge("stdio rpath recvfd", NULL) == -1)
2265 			err(1, "pledge");
2266 #endif
2267 		repo_write_main(title, pack_fds, temp_fds);
2268 		/* NOTREACHED */
2269 		exit(0);
2270 	default:
2271 		fatal("invalid process id %d", proc_id);
2272 	}
2273 
2274 	if (proc_id != PROC_GOTD)
2275 		fatal("invalid process id %d", proc_id);
2276 
2277 	apply_unveil();
2278 
2279 	signal_set(&evsigint, SIGINT, gotd_sighdlr, NULL);
2280 	signal_set(&evsigterm, SIGTERM, gotd_sighdlr, NULL);
2281 	signal_set(&evsighup, SIGHUP, gotd_sighdlr, NULL);
2282 	signal_set(&evsigusr1, SIGUSR1, gotd_sighdlr, NULL);
2283 	signal(SIGPIPE, SIG_IGN);
2284 
2285 	signal_add(&evsigint, NULL);
2286 	signal_add(&evsigterm, NULL);
2287 	signal_add(&evsighup, NULL);
2288 	signal_add(&evsigusr1, NULL);
2289 
2290 	event_set(&gotd.ev, fd, EV_READ | EV_PERSIST, gotd_accept, NULL);
2291 	if (event_add(&gotd.ev, NULL))
2292 		fatalx("event add");
2293 	evtimer_set(&gotd.pause, gotd_accept_paused, NULL);
2294 
2295 	event_dispatch();
2296 
2297 	if (fd != -1)
2298 		close(fd);
2299 	if (pack_fds)
2300 		got_repo_pack_fds_close(pack_fds);
2301 	free(repo_path);
2302 	return 0;
2303 }