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Date:: Fri Dec 30 14:47:10 2022 UTC
Message:: switch gotd from chroot(2) to unveil(2) In the future, gotd will fork+exec new processes for each client connection. Using unveil instead of chroot avoids having to start such processes as root. The -portable version could use chroot(2) where no equivalent to unveil(2) exists. A future component which starts new processes will be isolated as a separate process, which could run as root in the -portable version. 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 <grp.h>
33 #include <imsg.h>
34 #include <sha1.h>
35 #include <signal.h>
36 #include <siphash.h>
37 #include <stdarg.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <syslog.h>
42 #include <unistd.h>
43 
44 #include "got_error.h"
45 #include "got_opentemp.h"
46 #include "got_path.h"
47 #include "got_repository.h"
48 #include "got_object.h"
49 #include "got_reference.h"
50 
51 #include "got_lib_delta.h"
52 #include "got_lib_object.h"
53 #include "got_lib_object_cache.h"
54 #include "got_lib_sha1.h"
55 #include "got_lib_gitproto.h"
56 #include "got_lib_pack.h"
57 #include "got_lib_repository.h"
58 
59 #include "gotd.h"
60 #include "log.h"
61 #include "listen.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 struct gotd gotd;
96 
97 void gotd_sighdlr(int sig, short event, void *arg);
98 static void gotd_shutdown(void);
99 
100 __dead static void
101 usage()
102 {
103 	fprintf(stderr, "usage: %s [-dv] [-f config-file]\n", getprogname());
104 	exit(1);
105 }
106 
107 static int
108 unix_socket_listen(const char *unix_socket_path, uid_t uid, gid_t gid)
109 {
110 	struct sockaddr_un sun;
111 	int fd = -1;
112 	mode_t old_umask, mode;
113 
114 	fd = socket(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK| SOCK_CLOEXEC, 0);
115 	if (fd == -1) {
116 		log_warn("socket");
117 		return -1;
118 	}
119 
120 	sun.sun_family = AF_UNIX;
121 	if (strlcpy(sun.sun_path, unix_socket_path,
122 	    sizeof(sun.sun_path)) >= sizeof(sun.sun_path)) {
123 		log_warnx("%s: name too long", unix_socket_path);
124 		close(fd);
125 		return -1;
126 	}
127 
128 	if (unlink(unix_socket_path) == -1) {
129 		if (errno != ENOENT) {
130 			log_warn("unlink %s", unix_socket_path);
131 			close(fd);
132 			return -1;
133 		}
134 	}
135 
136 	old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);
137 	mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP;
138 
139 	if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
140 		log_warn("bind: %s", unix_socket_path);
141 		close(fd);
142 		umask(old_umask);
143 		return -1;
144 	}
145 
146 	umask(old_umask);
147 
148 	if (chmod(unix_socket_path, mode) == -1) {
149 		log_warn("chmod %o %s", mode, unix_socket_path);
150 		close(fd);
151 		unlink(unix_socket_path);
152 		return -1;
153 	}
154 
155 	if (chown(unix_socket_path, uid, gid) == -1) {
156 		log_warn("chown %s uid=%d gid=%d", unix_socket_path, uid, gid);
157 		close(fd);
158 		unlink(unix_socket_path);
159 		return -1;
160 	}
161 
162 	if (listen(fd, GOTD_UNIX_SOCKET_BACKLOG) == -1) {
163 		log_warn("listen");
164 		close(fd);
165 		unlink(unix_socket_path);
166 		return -1;
167 	}
168 
169 	return fd;
170 }
171 
172 static struct group *
173 match_group(gid_t *groups, int ngroups, const char *unix_group_name)
174 {
175 	struct group *gr;
176 	int i;
177 
178 	for (i = 0; i < ngroups; i++) {
179 		gr = getgrgid(groups[i]);
180 		if (gr == NULL) {
181 			log_warn("getgrgid %d", groups[i]);
182 			continue;
183 		}
184 		if (strcmp(gr->gr_name, unix_group_name) == 0)
185 			return gr;
186 	}
187 
188 	return NULL;
189 }
190 
191 static uint64_t
192 client_hash(uint32_t client_id)
193 {
194 	return SipHash24(&clients_hash_key, &client_id, sizeof(client_id));
195 }
196 
197 static void
198 add_client(struct gotd_client *client)
199 {
200 	uint64_t slot = client_hash(client->id) % nitems(gotd_clients);
201 	STAILQ_INSERT_HEAD(&gotd_clients[slot], client, entry);
202 	client_cnt++;
203 }
204 
205 static struct gotd_client *
206 find_client(uint32_t client_id)
207 {
208 	uint64_t slot;
209 	struct gotd_client *c;
210 
211 	slot = client_hash(client_id) % nitems(gotd_clients);
212 	STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
213 		if (c->id == client_id)
214 			return c;
215 	}
216 
217 	return NULL;
218 }
219 
220 static struct gotd_child_proc *
221 get_client_proc(struct gotd_client *client)
222 {
223 	if (client->repo_read && client->repo_write) {
224 		fatalx("uid %d is reading and writing in the same session",
225 		    client->euid);
226 		/* NOTREACHED */
227 	}
228 
229 	if (client->repo_read)
230 		return client->repo_read;
231 	else if (client->repo_write)
232 		return client->repo_write;
233 
234 	return NULL;
235 }
236 
237 static int
238 client_is_reading(struct gotd_client *client)
239 {
240 	return client->repo_read != NULL;
241 }
242 
243 static int
244 client_is_writing(struct gotd_client *client)
245 {
246 	return client->repo_write != NULL;
247 }
248 
249 static const struct got_error *
250 ensure_client_is_reading(struct gotd_client *client)
251 {
252 	if (!client_is_reading(client)) {
253 		return got_error_fmt(GOT_ERR_BAD_PACKET,
254 		    "uid %d made a read-request but is not reading from "
255 		    "a repository", client->euid);
256 	}
257 
258 	return NULL;
259 }
260 
261 static const struct got_error *
262 ensure_client_is_writing(struct gotd_client *client)
263 {
264 	if (!client_is_writing(client)) {
265 		return got_error_fmt(GOT_ERR_BAD_PACKET,
266 		    "uid %d made a write-request but is not writing to "
267 		    "a repository", client->euid);
268 	}
269 
270 	return NULL;
271 }
272 
273 static const struct got_error *
274 ensure_client_is_not_writing(struct gotd_client *client)
275 {
276 	if (client_is_writing(client)) {
277 		return got_error_fmt(GOT_ERR_BAD_PACKET,
278 		    "uid %d made a read-request but is writing to "
279 		    "a repository", client->euid);
280 	}
281 
282 	return NULL;
283 }
284 
285 static const struct got_error *
286 ensure_client_is_not_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 write-request but is reading from "
291 		    "a repository", client->euid);
292 	}
293 
294 	return NULL;
295 }
296 
297 static void
298 disconnect(struct gotd_client *client)
299 {
300 	struct gotd_imsg_disconnect idisconnect;
301 	struct gotd_child_proc *proc = get_client_proc(client);
302 	struct gotd_child_proc *listen_proc = &gotd.procs[0];
303 	uint64_t slot;
304 
305 	log_debug("uid %d: disconnecting", client->euid);
306 
307 	idisconnect.client_id = client->id;
308 	if (proc) {
309 		if (gotd_imsg_compose_event(&proc->iev,
310 		    GOTD_IMSG_DISCONNECT, PROC_GOTD, -1,
311 		    &idisconnect, sizeof(idisconnect)) == -1)
312 			log_warn("imsg compose DISCONNECT");
313 	}
314 
315 	if (gotd_imsg_compose_event(&listen_proc->iev,
316 	    GOTD_IMSG_DISCONNECT, PROC_GOTD, -1,
317 	    &idisconnect, sizeof(idisconnect)) == -1)
318 		log_warn("imsg compose DISCONNECT");
319 
320 	slot = client_hash(client->id) % nitems(gotd_clients);
321 	STAILQ_REMOVE(&gotd_clients[slot], client, gotd_client, entry);
322 	imsg_clear(&client->iev.ibuf);
323 	event_del(&client->iev.ev);
324 	evtimer_del(&client->tmo);
325 	close(client->fd);
326 	if (client->delta_cache_fd != -1)
327 		close(client->delta_cache_fd);
328 	if (client->packfile_path) {
329 		if (unlink(client->packfile_path) == -1 && errno != ENOENT)
330 			log_warn("unlink %s: ", client->packfile_path);
331 		free(client->packfile_path);
332 	}
333 	if (client->packidx_path) {
334 		if (unlink(client->packidx_path) == -1 && errno != ENOENT)
335 			log_warn("unlink %s: ", client->packidx_path);
336 		free(client->packidx_path);
337 	}
338 	free(client->capabilities);
339 	free(client);
340 	client_cnt--;
341 }
342 
343 static void
344 disconnect_on_error(struct gotd_client *client, const struct got_error *err)
345 {
346 	struct imsgbuf ibuf;
347 
348 	log_warnx("uid %d: %s", client->euid, err->msg);
349 	if (err->code != GOT_ERR_EOF) {
350 		imsg_init(&ibuf, client->fd);
351 		gotd_imsg_send_error(&ibuf, 0, PROC_GOTD, err);
352 		imsg_clear(&ibuf);
353 	}
354 	disconnect(client);
355 }
356 
357 static const struct got_error *
358 send_repo_info(struct gotd_imsgev *iev, struct gotd_repo *repo)
359 {
360 	const struct got_error *err = NULL;
361 	struct gotd_imsg_info_repo irepo;
362 
363 	memset(&irepo, 0, sizeof(irepo));
364 
365 	if (strlcpy(irepo.repo_name, repo->name, sizeof(irepo.repo_name))
366 	    >= sizeof(irepo.repo_name))
367 		return got_error_msg(GOT_ERR_NO_SPACE, "repo name too long");
368 	if (strlcpy(irepo.repo_path, repo->path, sizeof(irepo.repo_path))
369 	    >= sizeof(irepo.repo_path))
370 		return got_error_msg(GOT_ERR_NO_SPACE, "repo path too long");
371 
372 	if (gotd_imsg_compose_event(iev, GOTD_IMSG_INFO_REPO, PROC_GOTD, -1,
373 	    &irepo, sizeof(irepo)) == -1) {
374 		err = got_error_from_errno("imsg compose INFO_REPO");
375 		if (err)
376 			return err;
377 	}
378 
379 	return NULL;
380 }
381 
382 static const struct got_error *
383 send_capability(struct gotd_client_capability *capa, struct gotd_imsgev* iev)
384 {
385 	const struct got_error *err = NULL;
386 	struct gotd_imsg_capability icapa;
387 	size_t len;
388 	struct ibuf *wbuf;
389 
390 	memset(&icapa, 0, sizeof(icapa));
391 
392 	icapa.key_len = strlen(capa->key);
393 	len = sizeof(icapa) + icapa.key_len;
394 	if (capa->value) {
395 		icapa.value_len = strlen(capa->value);
396 		len += icapa.value_len;
397 	}
398 
399 	wbuf = imsg_create(&iev->ibuf, GOTD_IMSG_CAPABILITY, 0, 0, len);
400 	if (wbuf == NULL) {
401 		err = got_error_from_errno("imsg_create CAPABILITY");
402 		return err;
403 	}
404 
405 	if (imsg_add(wbuf, &icapa, sizeof(icapa)) == -1)
406 		return got_error_from_errno("imsg_add CAPABILITY");
407 	if (imsg_add(wbuf, capa->key, icapa.key_len) == -1)
408 		return got_error_from_errno("imsg_add CAPABILITY");
409 	if (capa->value) {
410 		if (imsg_add(wbuf, capa->value, icapa.value_len) == -1)
411 			return got_error_from_errno("imsg_add CAPABILITY");
412 	}
413 
414 	wbuf->fd = -1;
415 	imsg_close(&iev->ibuf, wbuf);
416 
417 	gotd_imsg_event_add(iev);
418 
419 	return NULL;
420 }
421 
422 static const struct got_error *
423 send_client_info(struct gotd_imsgev *iev, struct gotd_client *client)
424 {
425 	const struct got_error *err = NULL;
426 	struct gotd_imsg_info_client iclient;
427 	struct gotd_child_proc *proc;
428 	size_t i;
429 
430 	memset(&iclient, 0, sizeof(iclient));
431 	iclient.euid = client->euid;
432 	iclient.egid = client->egid;
433 
434 	proc = get_client_proc(client);
435 	if (proc) {
436 		if (strlcpy(iclient.repo_name, proc->repo_path,
437 		    sizeof(iclient.repo_name)) >= sizeof(iclient.repo_name)) {
438 			return got_error_msg(GOT_ERR_NO_SPACE,
439 			    "repo name too long");
440 		}
441 		if (client_is_writing(client))
442 			iclient.is_writing = 1;
443 	}
444 
445 	iclient.state = client->state;
446 	iclient.ncapabilities = client->ncapabilities;
447 
448 	if (gotd_imsg_compose_event(iev, GOTD_IMSG_INFO_CLIENT, PROC_GOTD, -1,
449 	    &iclient, sizeof(iclient)) == -1) {
450 		err = got_error_from_errno("imsg compose INFO_CLIENT");
451 		if (err)
452 			return err;
453 	}
454 
455 	for (i = 0; i < client->ncapabilities; i++) {
456 		struct gotd_client_capability *capa;
457 		capa = &client->capabilities[i];
458 		err = send_capability(capa, iev);
459 		if (err)
460 			return err;
461 	}
462 
463 	return NULL;
464 }
465 
466 static const struct got_error *
467 send_info(struct gotd_client *client)
468 {
469 	const struct got_error *err = NULL;
470 	struct gotd_imsg_info info;
471 	uint64_t slot;
472 	struct gotd_repo *repo;
473 
474 	info.pid = gotd.pid;
475 	info.verbosity = gotd.verbosity;
476 	info.nrepos = gotd.nrepos;
477 	info.nclients = client_cnt - 1;
478 
479 	if (gotd_imsg_compose_event(&client->iev, GOTD_IMSG_INFO, PROC_GOTD, -1,
480 	    &info, sizeof(info)) == -1) {
481 		err = got_error_from_errno("imsg compose INFO");
482 		if (err)
483 			return err;
484 	}
485 
486 	TAILQ_FOREACH(repo, &gotd.repos, entry) {
487 		err = send_repo_info(&client->iev, repo);
488 		if (err)
489 			return err;
490 	}
491 
492 	for (slot = 0; slot < nitems(gotd_clients); slot++) {
493 		struct gotd_client *c;
494 		STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
495 			if (c->id == client->id)
496 				continue;
497 			err = send_client_info(&client->iev, c);
498 			if (err)
499 				return err;
500 		}
501 	}
502 
503 	return NULL;
504 }
505 
506 static const struct got_error *
507 stop_gotd(struct gotd_client *client)
508 {
509 
510 	if (client->euid != 0)
511 		return got_error_set_errno(EPERM, "stop");
512 
513 	gotd_shutdown();
514 	/* NOTREACHED */
515 	return NULL;
516 }
517 
518 static struct gotd_repo *
519 find_repo_by_name(const char *repo_name)
520 {
521 	struct gotd_repo *repo;
522 	size_t namelen;
523 
524 	TAILQ_FOREACH(repo, &gotd.repos, entry) {
525 		namelen = strlen(repo->name);
526 		if (strncmp(repo->name, repo_name, namelen) != 0)
527 			continue;
528 		if (repo_name[namelen] == '\0' ||
529 		    strcmp(&repo_name[namelen], ".git") == 0)
530 			return repo;
531 	}
532 
533 	return NULL;
534 }
535 
536 static struct gotd_child_proc *
537 find_proc_by_repo_name(enum gotd_procid proc_id, const char *repo_name)
538 {
539 	struct gotd_child_proc *proc;
540 	int i;
541 	size_t namelen;
542 
543 	for (i = 0; i < gotd.nprocs; i++) {
544 		proc = &gotd.procs[i];
545 		if (proc->type != proc_id)
546 			continue;
547 		namelen = strlen(proc->repo_name);
548 		if (strncmp(proc->repo_name, repo_name, namelen) != 0)
549 			continue;
550 		if (repo_name[namelen] == '\0' ||
551 		    strcmp(&repo_name[namelen], ".git") == 0)
552 			return proc;
553 	}
554 
555 	return NULL;
556 }
557 
558 static struct gotd_child_proc *
559 find_proc_by_fd(int fd)
560 {
561 	struct gotd_child_proc *proc;
562 	int i;
563 
564 	for (i = 0; i < gotd.nprocs; i++) {
565 		proc = &gotd.procs[i];
566 		if (proc->iev.ibuf.fd == fd)
567 			return proc;
568 	}
569 
570 	return NULL;
571 }
572 
573 static const struct got_error *
574 forward_list_refs_request(struct gotd_client *client, struct imsg *imsg)
575 {
576 	const struct got_error *err;
577 	struct gotd_imsg_list_refs ireq;
578 	struct gotd_imsg_list_refs_internal ilref;
579 	struct gotd_repo *repo = NULL;
580 	struct gotd_child_proc *proc = NULL;
581 	size_t datalen;
582 	int fd = -1;
583 
584 	log_debug("list-refs request from uid %d", client->euid);
585 
586 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
587 	if (datalen != sizeof(ireq))
588 		return got_error(GOT_ERR_PRIVSEP_LEN);
589 
590 	memcpy(&ireq, imsg->data, datalen);
591 
592 	memset(&ilref, 0, sizeof(ilref));
593 	ilref.client_id = client->id;
594 
595 	if (ireq.client_is_reading) {
596 		err = ensure_client_is_not_writing(client);
597 		if (err)
598 			return err;
599 		repo = find_repo_by_name(ireq.repo_name);
600 		if (repo == NULL)
601 			return got_error(GOT_ERR_NOT_GIT_REPO);
602 		err = gotd_auth_check(&repo->rules, repo->name,
603 		    client->euid, client->egid, GOTD_AUTH_READ);
604 		if (err)
605 			return err;
606 		client->repo_read = find_proc_by_repo_name(PROC_REPO_READ,
607 		    ireq.repo_name);
608 		if (client->repo_read == NULL)
609 			return got_error(GOT_ERR_NOT_GIT_REPO);
610 	} else {
611 		err = ensure_client_is_not_reading(client);
612 		if (err)
613 			return err;
614 		repo = find_repo_by_name(ireq.repo_name);
615 		if (repo == NULL)
616 			return got_error(GOT_ERR_NOT_GIT_REPO);
617 		err = gotd_auth_check(&repo->rules, repo->name, client->euid,
618 		    client->egid, GOTD_AUTH_READ | GOTD_AUTH_WRITE);
619 		if (err)
620 			return err;
621 		client->repo_write = find_proc_by_repo_name(PROC_REPO_WRITE,
622 		    ireq.repo_name);
623 		if (client->repo_write == NULL)
624 			return got_error(GOT_ERR_NOT_GIT_REPO);
625 	}
626 
627 	fd = dup(client->fd);
628 	if (fd == -1)
629 		return got_error_from_errno("dup");
630 
631 	proc = get_client_proc(client);
632 	if (proc == NULL)
633 		fatalx("no process found for uid %d", client->euid);
634 	if (gotd_imsg_compose_event(&proc->iev,
635 	    GOTD_IMSG_LIST_REFS_INTERNAL, PROC_GOTD, fd,
636 	    &ilref, sizeof(ilref)) == -1) {
637 		err = got_error_from_errno("imsg compose WANT");
638 		close(fd);
639 		return err;
640 	}
641 
642 	return NULL;
643 }
644 
645 static const struct got_error *
646 forward_want(struct gotd_client *client, struct imsg *imsg)
647 {
648 	struct gotd_imsg_want ireq;
649 	struct gotd_imsg_want iwant;
650 	size_t datalen;
651 
652 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
653 	if (datalen != sizeof(ireq))
654 		return got_error(GOT_ERR_PRIVSEP_LEN);
655 
656 	memcpy(&ireq, imsg->data, datalen);
657 
658 	memset(&iwant, 0, sizeof(iwant));
659 	memcpy(iwant.object_id, ireq.object_id, SHA1_DIGEST_LENGTH);
660 	iwant.client_id = client->id;
661 
662 	if (gotd_imsg_compose_event(&client->repo_read->iev, GOTD_IMSG_WANT,
663 	    PROC_GOTD, -1, &iwant, sizeof(iwant)) == -1)
664 		return got_error_from_errno("imsg compose WANT");
665 
666 	return NULL;
667 }
668 
669 static const struct got_error *
670 forward_ref_update(struct gotd_client *client, struct imsg *imsg)
671 {
672 	const struct got_error *err = NULL;
673 	struct gotd_imsg_ref_update ireq;
674 	struct gotd_imsg_ref_update *iref = NULL;
675 	size_t datalen;
676 
677 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
678 	if (datalen < sizeof(ireq))
679 		return got_error(GOT_ERR_PRIVSEP_LEN);
680 	memcpy(&ireq, imsg->data, sizeof(ireq));
681 	if (datalen != sizeof(ireq) + ireq.name_len)
682 		return got_error(GOT_ERR_PRIVSEP_LEN);
683 
684 	iref = malloc(datalen);
685 	if (iref == NULL)
686 		return got_error_from_errno("malloc");
687 	memcpy(iref, imsg->data, datalen);
688 
689 	iref->client_id = client->id;
690 	if (gotd_imsg_compose_event(&client->repo_write->iev,
691 	    GOTD_IMSG_REF_UPDATE, PROC_GOTD, -1, iref, datalen) == -1)
692 		err = got_error_from_errno("imsg compose REF_UPDATE");
693 	free(iref);
694 	return err;
695 }
696 
697 static const struct got_error *
698 forward_have(struct gotd_client *client, struct imsg *imsg)
699 {
700 	struct gotd_imsg_have ireq;
701 	struct gotd_imsg_have ihave;
702 	size_t datalen;
703 
704 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
705 	if (datalen != sizeof(ireq))
706 		return got_error(GOT_ERR_PRIVSEP_LEN);
707 
708 	memcpy(&ireq, imsg->data, datalen);
709 
710 	memset(&ihave, 0, sizeof(ihave));
711 	memcpy(ihave.object_id, ireq.object_id, SHA1_DIGEST_LENGTH);
712 	ihave.client_id = client->id;
713 
714 	if (gotd_imsg_compose_event(&client->repo_read->iev, GOTD_IMSG_HAVE,
715 	    PROC_GOTD, -1, &ihave, sizeof(ihave)) == -1)
716 		return got_error_from_errno("imsg compose HAVE");
717 
718 	return NULL;
719 }
720 
721 static int
722 client_has_capability(struct gotd_client *client, const char *capastr)
723 {
724 	struct gotd_client_capability *capa;
725 	size_t i;
726 
727 	if (client->ncapabilities == 0)
728 		return 0;
729 
730 	for (i = 0; i < client->ncapabilities; i++) {
731 		capa = &client->capabilities[i];
732 		if (strcmp(capa->key, capastr) == 0)
733 			return 1;
734 	}
735 
736 	return 0;
737 }
738 
739 static const struct got_error *
740 recv_capabilities(struct gotd_client *client, struct imsg *imsg)
741 {
742 	struct gotd_imsg_capabilities icapas;
743 	size_t datalen;
744 
745 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
746 	if (datalen != sizeof(icapas))
747 		return got_error(GOT_ERR_PRIVSEP_LEN);
748 	memcpy(&icapas, imsg->data, sizeof(icapas));
749 
750 	client->ncapa_alloc = icapas.ncapabilities;
751 	client->capabilities = calloc(client->ncapa_alloc,
752 	    sizeof(*client->capabilities));
753 	if (client->capabilities == NULL) {
754 		client->ncapa_alloc = 0;
755 		return got_error_from_errno("calloc");
756 	}
757 
758 	log_debug("expecting %zu capabilities from uid %d",
759 	    client->ncapa_alloc, client->euid);
760 	return NULL;
761 }
762 
763 static const struct got_error *
764 recv_capability(struct gotd_client *client, struct imsg *imsg)
765 {
766 	struct gotd_imsg_capability icapa;
767 	struct gotd_client_capability *capa;
768 	size_t datalen;
769 	char *key, *value = NULL;
770 
771 	if (client->capabilities == NULL ||
772 	    client->ncapabilities >= client->ncapa_alloc) {
773 		return got_error_msg(GOT_ERR_BAD_REQUEST,
774 		    "unexpected capability received");
775 	}
776 
777 	memset(&icapa, 0, sizeof(icapa));
778 
779 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
780 	if (datalen < sizeof(icapa))
781 		return got_error(GOT_ERR_PRIVSEP_LEN);
782 	memcpy(&icapa, imsg->data, sizeof(icapa));
783 
784 	if (datalen != sizeof(icapa) + icapa.key_len + icapa.value_len)
785 		return got_error(GOT_ERR_PRIVSEP_LEN);
786 
787 	key = malloc(icapa.key_len + 1);
788 	if (key == NULL)
789 		return got_error_from_errno("malloc");
790 	if (icapa.value_len > 0) {
791 		value = malloc(icapa.value_len + 1);
792 		if (value == NULL) {
793 			free(key);
794 			return got_error_from_errno("malloc");
795 		}
796 	}
797 
798 	memcpy(key, imsg->data + sizeof(icapa), icapa.key_len);
799 	key[icapa.key_len] = '\0';
800 	if (value) {
801 		memcpy(value, imsg->data + sizeof(icapa) + icapa.key_len,
802 		    icapa.value_len);
803 		value[icapa.value_len] = '\0';
804 	}
805 
806 	capa = &client->capabilities[client->ncapabilities++];
807 	capa->key = key;
808 	capa->value = value;
809 
810 	if (value)
811 		log_debug("uid %d: capability %s=%s", client->euid, key, value);
812 	else
813 		log_debug("uid %d: capability %s", client->euid, key);
814 
815 	return NULL;
816 }
817 
818 static const struct got_error *
819 send_packfile(struct gotd_client *client)
820 {
821 	const struct got_error *err = NULL;
822 	struct gotd_imsg_send_packfile ipack;
823 	struct gotd_imsg_packfile_pipe ipipe;
824 	int pipe[2];
825 
826 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe) == -1)
827 		return got_error_from_errno("socketpair");
828 
829 	memset(&ipack, 0, sizeof(ipack));
830 	memset(&ipipe, 0, sizeof(ipipe));
831 
832 	ipack.client_id = client->id;
833 	if (client_has_capability(client, GOT_CAPA_SIDE_BAND_64K))
834 		ipack.report_progress = 1;
835 
836 	client->delta_cache_fd = got_opentempfd();
837 	if (client->delta_cache_fd == -1)
838 		return got_error_from_errno("got_opentempfd");
839 
840 	if (gotd_imsg_compose_event(&client->repo_read->iev,
841 	    GOTD_IMSG_SEND_PACKFILE, PROC_GOTD, client->delta_cache_fd,
842 	    &ipack, sizeof(ipack)) == -1) {
843 		err = got_error_from_errno("imsg compose SEND_PACKFILE");
844 		close(pipe[0]);
845 		close(pipe[1]);
846 		return err;
847 	}
848 
849 	ipipe.client_id = client->id;
850 
851 	/* Send pack pipe end 0 to repo_read. */
852 	if (gotd_imsg_compose_event(&client->repo_read->iev,
853 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[0],
854 	        &ipipe, sizeof(ipipe)) == -1) {
855 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
856 		close(pipe[1]);
857 		return err;
858 	}
859 
860 	/* Send pack pipe end 1 to gotsh(1) (expects just an fd, no data). */
861 	if (gotd_imsg_compose_event(&client->iev,
862 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[1], NULL, 0) == -1)
863 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
864 
865 	return err;
866 }
867 
868 static const struct got_error *
869 recv_packfile(struct gotd_client *client)
870 {
871 	const struct got_error *err = NULL;
872 	struct gotd_imsg_recv_packfile ipack;
873 	struct gotd_imsg_packfile_pipe ipipe;
874 	struct gotd_imsg_packidx_file ifile;
875 	char *basepath = NULL, *pack_path = NULL, *idx_path = NULL;
876 	int packfd = -1, idxfd = -1;
877 	int pipe[2] = { -1, -1 };
878 
879 	if (client->packfile_path) {
880 		return got_error_fmt(GOT_ERR_PRIVSEP_MSG,
881 		    "uid %d already has a pack file", client->euid);
882 	}
883 
884 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe) == -1)
885 		return got_error_from_errno("socketpair");
886 
887 	memset(&ipipe, 0, sizeof(ipipe));
888 	ipipe.client_id = client->id;
889 
890 	if (gotd_imsg_compose_event(&client->repo_write->iev,
891 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[0],
892 	        &ipipe, sizeof(ipipe)) == -1) {
893 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
894 		pipe[0] = -1;
895 		goto done;
896 	}
897 	pipe[0] = -1;
898 
899 	if (gotd_imsg_compose_event(&client->repo_write->iev,
900 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[1],
901 	        &ipipe, sizeof(ipipe)) == -1)
902 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
903 	pipe[1] = -1;
904 
905 	if (asprintf(&basepath, "%s/%s/receiving-from-uid-%d.pack",
906 	    client->repo_write->repo_path, GOT_OBJECTS_PACK_DIR,
907 	    client->euid) == -1) {
908 		err = got_error_from_errno("asprintf");
909 		goto done;
910 	}
911 
912 	err = got_opentemp_named_fd(&pack_path, &packfd, basepath, "");
913 	if (err)
914 		goto done;
915 
916 	free(basepath);
917 	if (asprintf(&basepath, "%s/%s/receiving-from-uid-%d.idx",
918 	    client->repo_write->repo_path, GOT_OBJECTS_PACK_DIR,
919 	    client->euid) == -1) {
920 		err = got_error_from_errno("asprintf");
921 		basepath = NULL;
922 		goto done;
923 	}
924 	err = got_opentemp_named_fd(&idx_path, &idxfd, basepath, "");
925 	if (err)
926 		goto done;
927 
928 	memset(&ifile, 0, sizeof(ifile));
929 	ifile.client_id = client->id;
930 	if (gotd_imsg_compose_event(&client->repo_write->iev,
931 	    GOTD_IMSG_PACKIDX_FILE, PROC_GOTD, idxfd,
932 	    &ifile, sizeof(ifile)) == -1) {
933 		err = got_error_from_errno("imsg compose PACKIDX_FILE");
934 		idxfd = -1;
935 		goto done;
936 	}
937 	idxfd = -1;
938 
939 	memset(&ipack, 0, sizeof(ipack));
940 	ipack.client_id = client->id;
941 	if (client_has_capability(client, GOT_CAPA_REPORT_STATUS))
942 		ipack.report_status = 1;
943 
944 	if (gotd_imsg_compose_event(&client->repo_write->iev,
945 	    GOTD_IMSG_RECV_PACKFILE, PROC_GOTD, packfd,
946 	    &ipack, sizeof(ipack)) == -1) {
947 		err = got_error_from_errno("imsg compose RECV_PACKFILE");
948 		packfd = -1;
949 		goto done;
950 	}
951 	packfd = -1;
952 
953 done:
954 	free(basepath);
955 	if (pipe[0] != -1 && close(pipe[0]) == -1 && err == NULL)
956 		err = got_error_from_errno("close");
957 	if (pipe[1] != -1 && close(pipe[1]) == -1 && err == NULL)
958 		err = got_error_from_errno("close");
959 	if (packfd != -1 && close(packfd) == -1 && err == NULL)
960 		err = got_error_from_errno("close");
961 	if (idxfd != -1 && close(idxfd) == -1 && err == NULL)
962 		err = got_error_from_errno("close");
963 	if (err) {
964 		free(pack_path);
965 		free(idx_path);
966 	} else {
967 		client->packfile_path = pack_path;
968 		client->packidx_path = idx_path;
969 	}
970 	return err;
971 }
972 
973 static void
974 gotd_request(int fd, short events, void *arg)
975 {
976 	struct gotd_imsgev *iev = arg;
977 	struct imsgbuf *ibuf = &iev->ibuf;
978 	struct gotd_client *client = iev->handler_arg;
979 	const struct got_error *err = NULL;
980 	struct imsg imsg;
981 	ssize_t n;
982 
983 	if (events & EV_WRITE) {
984 		while (ibuf->w.queued) {
985 			n = msgbuf_write(&ibuf->w);
986 			if (n == -1 && errno == EPIPE) {
987 				/*
988 				 * The client has closed its socket.
989 				 * This can happen when Git clients are
990 				 * done sending pack file data.
991 				*/
992 				msgbuf_clear(&ibuf->w);
993 				continue;
994 			} else if (n == -1 && errno != EAGAIN) {
995 				err = got_error_from_errno("imsg_flush");
996 				disconnect_on_error(client, err);
997 				return;
998 			}
999 			if (n == 0) {
1000 				/* Connection closed. */
1001 				err = got_error(GOT_ERR_EOF);
1002 				disconnect_on_error(client, err);
1003 				return;
1004 			}
1005 		}
1006 
1007 		/* Disconnect gotctl(8) now that messages have been sent. */
1008 		if (!client_is_reading(client) && !client_is_writing(client)) {
1009 			disconnect(client);
1010 			return;
1011 		}
1012 	}
1013 
1014 	if ((events & EV_READ) == 0)
1015 		return;
1016 
1017 	memset(&imsg, 0, sizeof(imsg));
1018 
1019 	while (err == NULL) {
1020 		err = gotd_imsg_recv(&imsg, ibuf, 0);
1021 		if (err) {
1022 			if (err->code == GOT_ERR_PRIVSEP_READ)
1023 				err = NULL;
1024 			break;
1025 		}
1026 
1027 		evtimer_del(&client->tmo);
1028 
1029 		switch (imsg.hdr.type) {
1030 		case GOTD_IMSG_INFO:
1031 			err = send_info(client);
1032 			break;
1033 		case GOTD_IMSG_STOP:
1034 			err = stop_gotd(client);
1035 			break;
1036 		case GOTD_IMSG_LIST_REFS:
1037 			if (client->state != GOTD_STATE_EXPECT_LIST_REFS) {
1038 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1039 				    "unexpected list-refs request received");
1040 				break;
1041 			}
1042 			err = forward_list_refs_request(client, &imsg);
1043 			if (err)
1044 				break;
1045 			client->state = GOTD_STATE_EXPECT_CAPABILITIES;
1046 			log_debug("uid %d: expecting capabilities",
1047 			    client->euid);
1048 			break;
1049 		case GOTD_IMSG_CAPABILITIES:
1050 			if (client->state != GOTD_STATE_EXPECT_CAPABILITIES) {
1051 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1052 				    "unexpected capabilities received");
1053 				break;
1054 			}
1055 			log_debug("receiving capabilities from uid %d",
1056 			    client->euid);
1057 			err = recv_capabilities(client, &imsg);
1058 			break;
1059 		case GOTD_IMSG_CAPABILITY:
1060 			if (client->state != GOTD_STATE_EXPECT_CAPABILITIES) {
1061 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1062 				    "unexpected capability received");
1063 				break;
1064 			}
1065 			err = recv_capability(client, &imsg);
1066 			if (err || client->ncapabilities < client->ncapa_alloc)
1067 				break;
1068 			if (client_is_reading(client)) {
1069 				client->state = GOTD_STATE_EXPECT_WANT;
1070 				log_debug("uid %d: expecting want-lines",
1071 				    client->euid);
1072 			} else if (client_is_writing(client)) {
1073 				client->state = GOTD_STATE_EXPECT_REF_UPDATE;
1074 				log_debug("uid %d: expecting ref-update-lines",
1075 				    client->euid);
1076 			} else
1077 				fatalx("client %d is both reading and writing",
1078 				    client->euid);
1079 			break;
1080 		case GOTD_IMSG_WANT:
1081 			if (client->state != GOTD_STATE_EXPECT_WANT) {
1082 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1083 				    "unexpected want-line received");
1084 				break;
1085 			}
1086 			log_debug("received want-line from uid %d",
1087 			    client->euid);
1088 			err = ensure_client_is_reading(client);
1089 			if (err)
1090 				break;
1091 			err = forward_want(client, &imsg);
1092 			break;
1093 		case GOTD_IMSG_REF_UPDATE:
1094 			if (client->state != GOTD_STATE_EXPECT_REF_UPDATE) {
1095 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1096 				    "unexpected ref-update-line received");
1097 				break;
1098 			}
1099 			log_debug("received ref-update-line from uid %d",
1100 			    client->euid);
1101 			err = ensure_client_is_writing(client);
1102 			if (err)
1103 				break;
1104 			err = forward_ref_update(client, &imsg);
1105 			if (err)
1106 				break;
1107 			client->state = GOTD_STATE_EXPECT_MORE_REF_UPDATES;
1108 			break;
1109 		case GOTD_IMSG_HAVE:
1110 			if (client->state != GOTD_STATE_EXPECT_HAVE) {
1111 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1112 				    "unexpected have-line received");
1113 				break;
1114 			}
1115 			log_debug("received have-line from uid %d",
1116 			    client->euid);
1117 			err = ensure_client_is_reading(client);
1118 			if (err)
1119 				break;
1120 			err = forward_have(client, &imsg);
1121 			if (err)
1122 				break;
1123 			break;
1124 		case GOTD_IMSG_FLUSH:
1125 			if (client->state == GOTD_STATE_EXPECT_WANT ||
1126 			    client->state == GOTD_STATE_EXPECT_HAVE) {
1127 				err = ensure_client_is_reading(client);
1128 				if (err)
1129 					break;
1130 			} else if (client->state ==
1131 			    GOTD_STATE_EXPECT_MORE_REF_UPDATES) {
1132 				err = ensure_client_is_writing(client);
1133 				if (err)
1134 					break;
1135 			} else {
1136 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1137 				    "unexpected flush-pkt received");
1138 				break;
1139 			}
1140 			log_debug("received flush-pkt from uid %d",
1141 			    client->euid);
1142 			if (client->state == GOTD_STATE_EXPECT_WANT) {
1143 				client->state = GOTD_STATE_EXPECT_HAVE;
1144 				log_debug("uid %d: expecting have-lines",
1145 				    client->euid);
1146 			} else if (client->state == GOTD_STATE_EXPECT_HAVE) {
1147 				client->state = GOTD_STATE_EXPECT_DONE;
1148 				log_debug("uid %d: expecting 'done'",
1149 				    client->euid);
1150 			} else if (client->state ==
1151 			    GOTD_STATE_EXPECT_MORE_REF_UPDATES) {
1152 				client->state = GOTD_STATE_EXPECT_PACKFILE;
1153 				log_debug("uid %d: expecting packfile",
1154 				    client->euid);
1155 				err = recv_packfile(client);
1156 			} else {
1157 				/* should not happen, see above */
1158 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1159 				    "unexpected client state");
1160 				break;
1161 			}
1162 			break;
1163 		case GOTD_IMSG_DONE:
1164 			if (client->state != GOTD_STATE_EXPECT_HAVE &&
1165 			    client->state != GOTD_STATE_EXPECT_DONE) {
1166 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1167 				    "unexpected flush-pkt received");
1168 				break;
1169 			}
1170 			log_debug("received 'done' from uid %d", client->euid);
1171 			err = ensure_client_is_reading(client);
1172 			if (err)
1173 				break;
1174 			client->state = GOTD_STATE_DONE;
1175 			err = send_packfile(client);
1176 			break;
1177 		default:
1178 			err = got_error(GOT_ERR_PRIVSEP_MSG);
1179 			break;
1180 		}
1181 
1182 		imsg_free(&imsg);
1183 	}
1184 
1185 	if (err) {
1186 		if (err->code != GOT_ERR_EOF ||
1187 		    client->state != GOTD_STATE_EXPECT_PACKFILE)
1188 			disconnect_on_error(client, err);
1189 	} else {
1190 		gotd_imsg_event_add(&client->iev);
1191 		evtimer_add(&client->tmo, &timeout);
1192 	}
1193 }
1194 
1195 static void
1196 gotd_request_timeout(int fd, short events, void *arg)
1197 {
1198 	struct gotd_client *client = arg;
1199 
1200 	log_debug("disconnecting uid %d due to timeout", client->euid);
1201 	disconnect(client);
1202 }
1203 
1204 static const struct got_error *
1205 recv_connect(uint32_t *client_id, struct imsg *imsg)
1206 {
1207 	const struct got_error *err = NULL;
1208 	struct gotd_imsg_connect iconnect;
1209 	size_t datalen;
1210 	int s = -1;
1211 	struct gotd_client *client = NULL;
1212 	uid_t euid;
1213 	gid_t egid;
1214 
1215 	*client_id = 0;
1216 
1217 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1218 	if (datalen != sizeof(iconnect))
1219 		return got_error(GOT_ERR_PRIVSEP_LEN);
1220 	memcpy(&iconnect, imsg->data, sizeof(iconnect));
1221 
1222 	s = imsg->fd;
1223 	if (s == -1) {
1224 		err = got_error(GOT_ERR_PRIVSEP_NO_FD);
1225 		goto done;
1226 	}
1227 
1228 	if (find_client(iconnect.client_id)) {
1229 		err = got_error_msg(GOT_ERR_CLIENT_ID, "duplicate client ID");
1230 		goto done;
1231 	}
1232 
1233 	if (getpeereid(s, &euid, &egid) == -1) {
1234 		err = got_error_from_errno("getpeerid");
1235 		goto done;
1236 	}
1237 
1238 	client = calloc(1, sizeof(*client));
1239 	if (client == NULL) {
1240 		err = got_error_from_errno("calloc");
1241 		goto done;
1242 	}
1243 
1244 	*client_id = iconnect.client_id;
1245 
1246 	client->state = GOTD_STATE_EXPECT_LIST_REFS;
1247 	client->id = iconnect.client_id;
1248 	client->fd = s;
1249 	s = -1;
1250 	client->delta_cache_fd = -1;
1251 	client->euid = euid;
1252 	client->egid = egid;
1253 	client->nref_updates = -1;
1254 
1255 	imsg_init(&client->iev.ibuf, client->fd);
1256 	client->iev.handler = gotd_request;
1257 	client->iev.events = EV_READ;
1258 	client->iev.handler_arg = client;
1259 
1260 	event_set(&client->iev.ev, client->fd, EV_READ, gotd_request,
1261 	    &client->iev);
1262 	gotd_imsg_event_add(&client->iev);
1263 
1264 	evtimer_set(&client->tmo, gotd_request_timeout, client);
1265 
1266 	add_client(client);
1267 	log_debug("%s: new client uid %d connected on fd %d", __func__,
1268 	    client->euid, client->fd);
1269 done:
1270 	if (err) {
1271 		struct gotd_child_proc *listen_proc = &gotd.procs[0];
1272 		struct gotd_imsg_disconnect idisconnect;
1273 
1274 		idisconnect.client_id = client->id;
1275 		if (gotd_imsg_compose_event(&listen_proc->iev,
1276 		    GOTD_IMSG_DISCONNECT, PROC_GOTD, -1,
1277 		    &idisconnect, sizeof(idisconnect)) == -1)
1278 			log_warn("imsg compose DISCONNECT");
1279 
1280 		if (s != -1)
1281 			close(s);
1282 	}
1283 
1284 	return err;
1285 }
1286 
1287 static const char *gotd_proc_names[PROC_MAX] = {
1288 	"parent",
1289 	"listen",
1290 	"repo_read",
1291 	"repo_write"
1292 };
1293 
1294 static struct gotd_child_proc *
1295 get_proc_for_pid(pid_t pid)
1296 {
1297 	struct gotd_child_proc *proc;
1298 	int i;
1299 
1300 	for (i = 0; i < gotd.nprocs; i++) {
1301 		proc = &gotd.procs[i];
1302 		if (proc->pid == pid)
1303 			return proc;
1304 	}
1305 
1306 	return NULL;
1307 }
1308 
1309 static void
1310 kill_proc(struct gotd_child_proc *proc, int fatal)
1311 {
1312 	if (fatal) {
1313 		log_warnx("sending SIGKILL to PID %d", proc->pid);
1314 		kill(proc->pid, SIGKILL);
1315 	} else
1316 		kill(proc->pid, SIGTERM);
1317 }
1318 
1319 static void
1320 gotd_shutdown(void)
1321 {
1322 	pid_t	 pid;
1323 	int	 status, i;
1324 	struct gotd_child_proc *proc;
1325 
1326 	for (i = 0; i < gotd.nprocs; i++) {
1327 		proc = &gotd.procs[i];
1328 		msgbuf_clear(&proc->iev.ibuf.w);
1329 		close(proc->iev.ibuf.fd);
1330 		kill_proc(proc, 0);
1331 	}
1332 
1333 	log_debug("waiting for children to terminate");
1334 	do {
1335 		pid = wait(&status);
1336 		if (pid == -1) {
1337 			if (errno != EINTR && errno != ECHILD)
1338 				fatal("wait");
1339 		} else if (WIFSIGNALED(status)) {
1340 			proc = get_proc_for_pid(pid);
1341 			log_warnx("%s %s child process terminated; signal %d",
1342 			    proc ? gotd_proc_names[proc->type] : "",
1343 			    proc ? proc->repo_path : "", WTERMSIG(status));
1344 		}	
1345 	} while (pid != -1 || (pid == -1 && errno == EINTR));
1346 
1347 	log_info("terminating");
1348 	exit(0);
1349 }
1350 
1351 void
1352 gotd_sighdlr(int sig, short event, void *arg)
1353 {
1354 	/*
1355 	 * Normal signal handler rules don't apply because libevent
1356 	 * decouples for us.
1357 	 */
1358 
1359 	switch (sig) {
1360 	case SIGHUP:
1361 		log_info("%s: ignoring SIGHUP", __func__);
1362 		break;
1363 	case SIGUSR1:
1364 		log_info("%s: ignoring SIGUSR1", __func__);
1365 		break;
1366 	case SIGTERM:
1367 	case SIGINT:
1368 		gotd_shutdown();
1369 		log_warnx("gotd terminating");
1370 		exit(0);
1371 		break;
1372 	default:
1373 		fatalx("unexpected signal");
1374 	}
1375 }
1376 
1377 static const struct got_error *
1378 ensure_proc_is_reading(struct gotd_client *client,
1379     struct gotd_child_proc *proc)
1380 {
1381 	if (!client_is_reading(client)) {
1382 		kill_proc(proc, 1);
1383 		return got_error_fmt(GOT_ERR_BAD_PACKET,
1384 		    "PID %d handled a read-request for uid %d but this "
1385 		    "user is not reading from a repository", proc->pid,
1386 		    client->euid);
1387 	}
1388 
1389 	return NULL;
1390 }
1391 
1392 static const struct got_error *
1393 ensure_proc_is_writing(struct gotd_client *client,
1394     struct gotd_child_proc *proc)
1395 {
1396 	if (!client_is_writing(client)) {
1397 		kill_proc(proc, 1);
1398 		return got_error_fmt(GOT_ERR_BAD_PACKET,
1399 		    "PID %d handled a write-request for uid %d but this "
1400 		    "user is not writing to a repository", proc->pid,
1401 		    client->euid);
1402 	}
1403 
1404 	return NULL;
1405 }
1406 
1407 static int
1408 verify_imsg_src(struct gotd_client *client, struct gotd_child_proc *proc,
1409     struct imsg *imsg)
1410 {
1411 	const struct got_error *err;
1412 	struct gotd_child_proc *client_proc;
1413 	int ret = 0;
1414 
1415 	if (proc->type == PROC_REPO_READ || proc->type == PROC_REPO_WRITE) {
1416 		client_proc = get_client_proc(client);
1417 		if (client_proc == NULL)
1418 			fatalx("no process found for uid %d", client->euid);
1419 		if (proc->pid != client_proc->pid) {
1420 			kill_proc(proc, 1);
1421 			log_warnx("received message from PID %d for uid %d, "
1422 			    "while PID %d is the process serving this user",
1423 			    proc->pid, client->euid, client_proc->pid);
1424 			return 0;
1425 		}
1426 	}
1427 
1428 	switch (imsg->hdr.type) {
1429 	case GOTD_IMSG_ERROR:
1430 		ret = 1;
1431 		break;
1432 	case GOTD_IMSG_CONNECT:
1433 		if (proc->type != PROC_LISTEN) {
1434 			err = got_error_fmt(GOT_ERR_BAD_PACKET,
1435 			    "new connection for uid %d from PID %d "
1436 			    "which is not the listen process",
1437 			    proc->pid, client->euid);
1438 		} else
1439 			ret = 1;
1440 		break;
1441 	case GOTD_IMSG_PACKFILE_DONE:
1442 		err = ensure_proc_is_reading(client, proc);
1443 		if (err)
1444 			log_warnx("uid %d: %s", client->euid, err->msg);
1445 		else
1446 			ret = 1;
1447 		break;
1448 	case GOTD_IMSG_PACKFILE_INSTALL:
1449 	case GOTD_IMSG_REF_UPDATES_START:
1450 	case GOTD_IMSG_REF_UPDATE:
1451 		err = ensure_proc_is_writing(client, proc);
1452 		if (err)
1453 			log_warnx("uid %d: %s", client->euid, err->msg);
1454 		else
1455 			ret = 1;
1456 		break;
1457 	default:
1458 		log_debug("%s: unexpected imsg %d", __func__, imsg->hdr.type);
1459 		break;
1460 	}
1461 
1462 	return ret;
1463 }
1464 
1465 static const struct got_error *
1466 recv_packfile_done(uint32_t *client_id, struct imsg *imsg)
1467 {
1468 	struct gotd_imsg_packfile_done idone;
1469 	size_t datalen;
1470 
1471 	log_debug("packfile-done received");
1472 
1473 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1474 	if (datalen != sizeof(idone))
1475 		return got_error(GOT_ERR_PRIVSEP_LEN);
1476 	memcpy(&idone, imsg->data, sizeof(idone));
1477 
1478 	*client_id = idone.client_id;
1479 	return NULL;
1480 }
1481 
1482 static const struct got_error *
1483 recv_packfile_install(uint32_t *client_id, struct imsg *imsg)
1484 {
1485 	struct gotd_imsg_packfile_install inst;
1486 	size_t datalen;
1487 
1488 	log_debug("packfile-install received");
1489 
1490 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1491 	if (datalen != sizeof(inst))
1492 		return got_error(GOT_ERR_PRIVSEP_LEN);
1493 	memcpy(&inst, imsg->data, sizeof(inst));
1494 
1495 	*client_id = inst.client_id;
1496 	return NULL;
1497 }
1498 
1499 static const struct got_error *
1500 recv_ref_updates_start(uint32_t *client_id, struct imsg *imsg)
1501 {
1502 	struct gotd_imsg_ref_updates_start istart;
1503 	size_t datalen;
1504 
1505 	log_debug("ref-updates-start received");
1506 
1507 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1508 	if (datalen != sizeof(istart))
1509 		return got_error(GOT_ERR_PRIVSEP_LEN);
1510 	memcpy(&istart, imsg->data, sizeof(istart));
1511 
1512 	*client_id = istart.client_id;
1513 	return NULL;
1514 }
1515 
1516 static const struct got_error *
1517 recv_ref_update(uint32_t *client_id, struct imsg *imsg)
1518 {
1519 	struct gotd_imsg_ref_update iref;
1520 	size_t datalen;
1521 
1522 	log_debug("ref-update received");
1523 
1524 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1525 	if (datalen < sizeof(iref))
1526 		return got_error(GOT_ERR_PRIVSEP_LEN);
1527 	memcpy(&iref, imsg->data, sizeof(iref));
1528 
1529 	*client_id = iref.client_id;
1530 	return NULL;
1531 }
1532 
1533 static const struct got_error *
1534 send_ref_update_ok(struct gotd_client *client,
1535     struct gotd_imsg_ref_update *iref, const char *refname)
1536 {
1537 	struct gotd_imsg_ref_update_ok iok;
1538 	struct ibuf *wbuf;
1539 	size_t len;
1540 
1541 	memset(&iok, 0, sizeof(iok));
1542 	iok.client_id = client->id;
1543 	memcpy(iok.old_id, iref->old_id, SHA1_DIGEST_LENGTH);
1544 	memcpy(iok.new_id, iref->new_id, SHA1_DIGEST_LENGTH);
1545 	iok.name_len = strlen(refname);
1546 
1547 	len = sizeof(iok) + iok.name_len;
1548 	wbuf = imsg_create(&client->iev.ibuf, GOTD_IMSG_REF_UPDATE_OK,
1549 	    PROC_GOTD, gotd.pid, len);
1550 	if (wbuf == NULL)
1551 		return got_error_from_errno("imsg_create REF_UPDATE_OK");
1552 
1553 	if (imsg_add(wbuf, &iok, sizeof(iok)) == -1)
1554 		return got_error_from_errno("imsg_add REF_UPDATE_OK");
1555 	if (imsg_add(wbuf, refname, iok.name_len) == -1)
1556 		return got_error_from_errno("imsg_add REF_UPDATE_OK");
1557 
1558 	wbuf->fd = -1;
1559 	imsg_close(&client->iev.ibuf, wbuf);
1560 	gotd_imsg_event_add(&client->iev);
1561 	return NULL;
1562 }
1563 
1564 static void
1565 send_refs_updated(struct gotd_client *client)
1566 {
1567 	if (gotd_imsg_compose_event(&client->iev,
1568 	    GOTD_IMSG_REFS_UPDATED, PROC_GOTD, -1, NULL, 0) == -1)
1569 		log_warn("imsg compose REFS_UPDATED");
1570 }
1571 
1572 static const struct got_error *
1573 send_ref_update_ng(struct gotd_client *client,
1574     struct gotd_imsg_ref_update *iref, const char *refname,
1575     const char *reason)
1576 {
1577 	const struct got_error *ng_err;
1578 	struct gotd_imsg_ref_update_ng ing;
1579 	struct ibuf *wbuf;
1580 	size_t len;
1581 
1582 	memset(&ing, 0, sizeof(ing));
1583 	ing.client_id = client->id;
1584 	memcpy(ing.old_id, iref->old_id, SHA1_DIGEST_LENGTH);
1585 	memcpy(ing.new_id, iref->new_id, SHA1_DIGEST_LENGTH);
1586 	ing.name_len = strlen(refname);
1587 
1588 	ng_err = got_error_fmt(GOT_ERR_REF_BUSY, "%s", reason);
1589 	ing.reason_len = strlen(ng_err->msg);
1590 
1591 	len = sizeof(ing) + ing.name_len + ing.reason_len;
1592 	wbuf = imsg_create(&client->iev.ibuf, GOTD_IMSG_REF_UPDATE_NG,
1593 	    PROC_GOTD, gotd.pid, len);
1594 	if (wbuf == NULL)
1595 		return got_error_from_errno("imsg_create REF_UPDATE_NG");
1596 
1597 	if (imsg_add(wbuf, &ing, sizeof(ing)) == -1)
1598 		return got_error_from_errno("imsg_add REF_UPDATE_NG");
1599 	if (imsg_add(wbuf, refname, ing.name_len) == -1)
1600 		return got_error_from_errno("imsg_add REF_UPDATE_NG");
1601 	if (imsg_add(wbuf, ng_err->msg, ing.reason_len) == -1)
1602 		return got_error_from_errno("imsg_add REF_UPDATE_NG");
1603 
1604 	wbuf->fd = -1;
1605 	imsg_close(&client->iev.ibuf, wbuf);
1606 	gotd_imsg_event_add(&client->iev);
1607 	return NULL;
1608 }
1609 
1610 static const struct got_error *
1611 install_pack(struct gotd_client *client, const char *repo_path,
1612     struct imsg *imsg)
1613 {
1614 	const struct got_error *err = NULL;
1615 	struct gotd_imsg_packfile_install inst;
1616 	char hex[SHA1_DIGEST_STRING_LENGTH];
1617 	size_t datalen;
1618 	char *packfile_path = NULL, *packidx_path = NULL;
1619 
1620 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1621 	if (datalen != sizeof(inst))
1622 		return got_error(GOT_ERR_PRIVSEP_LEN);
1623 	memcpy(&inst, imsg->data, sizeof(inst));
1624 
1625 	if (client->packfile_path == NULL)
1626 		return got_error_msg(GOT_ERR_BAD_REQUEST,
1627 		    "client has no pack file");
1628 	if (client->packidx_path == NULL)
1629 		return got_error_msg(GOT_ERR_BAD_REQUEST,
1630 		    "client has no pack file index");
1631 
1632 	if (got_sha1_digest_to_str(inst.pack_sha1, hex, sizeof(hex)) == NULL)
1633 		return got_error_msg(GOT_ERR_NO_SPACE,
1634 		    "could not convert pack file SHA1 to hex");
1635 
1636 	if (asprintf(&packfile_path, "/%s/%s/pack-%s.pack",
1637 	    repo_path, GOT_OBJECTS_PACK_DIR, hex) == -1) {
1638 		err = got_error_from_errno("asprintf");
1639 		goto done;
1640 	}
1641 
1642 	if (asprintf(&packidx_path, "/%s/%s/pack-%s.idx",
1643 	    repo_path, GOT_OBJECTS_PACK_DIR, hex) == -1) {
1644 		err = got_error_from_errno("asprintf");
1645 		goto done;
1646 	}
1647 
1648 	if (rename(client->packfile_path, packfile_path) == -1) {
1649 		err = got_error_from_errno3("rename", client->packfile_path,
1650 		    packfile_path);
1651 		goto done;
1652 	}
1653 
1654 	free(client->packfile_path);
1655 	client->packfile_path = NULL;
1656 
1657 	if (rename(client->packidx_path, packidx_path) == -1) {
1658 		err = got_error_from_errno3("rename", client->packidx_path,
1659 		    packidx_path);
1660 		goto done;
1661 	}
1662 
1663 	free(client->packidx_path);
1664 	client->packidx_path = NULL;
1665 done:
1666 	free(packfile_path);
1667 	free(packidx_path);
1668 	return err;
1669 }
1670 
1671 static const struct got_error *
1672 begin_ref_updates(struct gotd_client *client, struct imsg *imsg)
1673 {
1674 	struct gotd_imsg_ref_updates_start istart;
1675 	size_t datalen;
1676 
1677 	if (client->nref_updates != -1)
1678 		return got_error(GOT_ERR_PRIVSEP_MSG);
1679 
1680 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1681 	if (datalen != sizeof(istart))
1682 		return got_error(GOT_ERR_PRIVSEP_LEN);
1683 	memcpy(&istart, imsg->data, sizeof(istart));
1684 
1685 	if (istart.nref_updates <= 0)
1686 		return got_error(GOT_ERR_PRIVSEP_MSG);
1687 
1688 	client->nref_updates = istart.nref_updates;
1689 	return NULL;
1690 }
1691 
1692 static const struct got_error *
1693 update_ref(struct gotd_client *client, const char *repo_path,
1694     struct imsg *imsg)
1695 {
1696 	const struct got_error *err = NULL;
1697 	struct got_repository *repo = NULL;
1698 	struct got_reference *ref = NULL;
1699 	struct gotd_imsg_ref_update iref;
1700 	struct got_object_id old_id, new_id;
1701 	struct got_object_id *id = NULL;
1702 	struct got_object *obj = NULL;
1703 	char *refname = NULL;
1704 	size_t datalen;
1705 	int locked = 0;
1706 
1707 	log_debug("update-ref from uid %d", client->euid);
1708 
1709 	if (client->nref_updates <= 0)
1710 		return got_error(GOT_ERR_PRIVSEP_MSG);
1711 
1712 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1713 	if (datalen < sizeof(iref))
1714 		return got_error(GOT_ERR_PRIVSEP_LEN);
1715 	memcpy(&iref, imsg->data, sizeof(iref));
1716 	if (datalen != sizeof(iref) + iref.name_len)
1717 		return got_error(GOT_ERR_PRIVSEP_LEN);
1718 	refname = malloc(iref.name_len + 1);
1719 	if (refname == NULL)
1720 		return got_error_from_errno("malloc");
1721 	memcpy(refname, imsg->data + sizeof(iref), iref.name_len);
1722 	refname[iref.name_len] = '\0';
1723 
1724 	log_debug("updating ref %s for uid %d", refname, client->euid);
1725 
1726 	err = got_repo_open(&repo, repo_path, NULL, NULL);
1727 	if (err)
1728 		goto done;
1729 
1730 	memcpy(old_id.sha1, iref.old_id, SHA1_DIGEST_LENGTH);
1731 	memcpy(new_id.sha1, iref.new_id, SHA1_DIGEST_LENGTH);
1732 	err = got_object_open(&obj, repo, &new_id);
1733 	if (err)
1734 		goto done;
1735 
1736 	if (iref.ref_is_new) {
1737 		err = got_ref_open(&ref, repo, refname, 0);
1738 		if (err) {
1739 			if (err->code != GOT_ERR_NOT_REF)
1740 				goto done;
1741 			err = got_ref_alloc(&ref, refname, &new_id);
1742 			if (err)
1743 				goto done;
1744 			err = got_ref_write(ref, repo); /* will lock/unlock */
1745 			if (err)
1746 				goto done;
1747 		} else {
1748 			err = got_error_fmt(GOT_ERR_REF_BUSY,
1749 			    "%s has been created by someone else "
1750 			    "while transaction was in progress",
1751 			    got_ref_get_name(ref));
1752 			goto done;
1753 		}
1754 	} else {
1755 		err = got_ref_open(&ref, repo, refname, 1 /* lock */);
1756 		if (err)
1757 			goto done;
1758 		locked = 1;
1759 
1760 		err = got_ref_resolve(&id, repo, ref);
1761 		if (err)
1762 			goto done;
1763 
1764 		if (got_object_id_cmp(id, &old_id) != 0) {
1765 			err = got_error_fmt(GOT_ERR_REF_BUSY,
1766 			    "%s has been modified by someone else "
1767 			    "while transaction was in progress",
1768 			    got_ref_get_name(ref));
1769 			goto done;
1770 		}
1771 
1772 		err = got_ref_change_ref(ref, &new_id);
1773 		if (err)
1774 			goto done;
1775 
1776 		err = got_ref_write(ref, repo);
1777 		if (err)
1778 			goto done;
1779 
1780 		free(id);
1781 		id = NULL;
1782 	}
1783 done:
1784 	if (err) {
1785 		if (err->code == GOT_ERR_LOCKFILE_TIMEOUT) {
1786 			err = got_error_fmt(GOT_ERR_LOCKFILE_TIMEOUT,
1787 			    "could not acquire exclusive file lock for %s",
1788 			    refname);
1789 		}
1790 		send_ref_update_ng(client, &iref, refname, err->msg);
1791 	} else
1792 		send_ref_update_ok(client, &iref, refname);
1793 
1794 	if (client->nref_updates > 0) {
1795 		client->nref_updates--;
1796 		if (client->nref_updates == 0)
1797 			send_refs_updated(client);
1798 
1799 	}
1800 	if (locked) {
1801 		const struct got_error *unlock_err;
1802 		unlock_err = got_ref_unlock(ref);
1803 		if (unlock_err && err == NULL)
1804 			err = unlock_err;
1805 	}
1806 	if (ref)
1807 		got_ref_close(ref);
1808 	if (obj)
1809 		got_object_close(obj);
1810 	if (repo)
1811 		got_repo_close(repo);
1812 	free(refname);
1813 	free(id);
1814 	return err;
1815 }
1816 
1817 static void
1818 gotd_dispatch(int fd, short event, void *arg)
1819 {
1820 	struct gotd_imsgev *iev = arg;
1821 	struct imsgbuf *ibuf = &iev->ibuf;
1822 	struct gotd_child_proc *proc = NULL;
1823 	ssize_t n;
1824 	int shut = 0;
1825 	struct imsg imsg;
1826 
1827 	if (event & EV_READ) {
1828 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1829 			fatal("imsg_read error");
1830 		if (n == 0) {
1831 			/* Connection closed. */
1832 			shut = 1;
1833 			goto done;
1834 		}
1835 	}
1836 
1837 	if (event & EV_WRITE) {
1838 		n = msgbuf_write(&ibuf->w);
1839 		if (n == -1 && errno != EAGAIN)
1840 			fatal("msgbuf_write");
1841 		if (n == 0) {
1842 			/* Connection closed. */
1843 			shut = 1;
1844 			goto done;
1845 		}
1846 	}
1847 
1848 	proc = find_proc_by_fd(fd);
1849 	if (proc == NULL)
1850 		fatalx("cannot find child process for fd %d", fd);
1851 
1852 	for (;;) {
1853 		const struct got_error *err = NULL;
1854 		struct gotd_client *client = NULL;
1855 		uint32_t client_id = 0;
1856 		int do_disconnect = 0;
1857 		int do_ref_updates = 0, do_ref_update = 0;
1858 		int do_packfile_install = 0;
1859 
1860 		if ((n = imsg_get(ibuf, &imsg)) == -1)
1861 			fatal("%s: imsg_get error", __func__);
1862 		if (n == 0)	/* No more messages. */
1863 			break;
1864 
1865 		switch (imsg.hdr.type) {
1866 		case GOTD_IMSG_ERROR:
1867 			do_disconnect = 1;
1868 			err = gotd_imsg_recv_error(&client_id, &imsg);
1869 			break;
1870 		case GOTD_IMSG_CONNECT:
1871 			err = recv_connect(&client_id, &imsg);
1872 			break;
1873 		case GOTD_IMSG_PACKFILE_DONE:
1874 			do_disconnect = 1;
1875 			err = recv_packfile_done(&client_id, &imsg);
1876 			break;
1877 		case GOTD_IMSG_PACKFILE_INSTALL:
1878 			err = recv_packfile_install(&client_id, &imsg);
1879 			if (err == NULL)
1880 				do_packfile_install = 1;
1881 			break;
1882 		case GOTD_IMSG_REF_UPDATES_START:
1883 			err = recv_ref_updates_start(&client_id, &imsg);
1884 			if (err == NULL)
1885 				do_ref_updates = 1;
1886 			break;
1887 		case GOTD_IMSG_REF_UPDATE:
1888 			err = recv_ref_update(&client_id, &imsg);
1889 			if (err == NULL)
1890 				do_ref_update = 1;
1891 			break;
1892 		default:
1893 			log_debug("unexpected imsg %d", imsg.hdr.type);
1894 			break;
1895 		}
1896 
1897 		client = find_client(client_id);
1898 		if (client == NULL) {
1899 			log_warnx("%s: client not found", __func__);
1900 			imsg_free(&imsg);
1901 			continue;
1902 		}
1903 
1904 		if (!verify_imsg_src(client, proc, &imsg)) {
1905 			log_debug("dropping imsg type %d from PID %d",
1906 			    imsg.hdr.type, proc->pid);
1907 			imsg_free(&imsg);
1908 			continue;
1909 		}
1910 		if (err)
1911 			log_warnx("uid %d: %s", client->euid, err->msg);
1912 
1913 		if (do_disconnect) {
1914 			if (err)
1915 				disconnect_on_error(client, err);
1916 			else
1917 				disconnect(client);
1918 		} else {
1919 			if (do_packfile_install)
1920 				err = install_pack(client, proc->repo_path,
1921 				    &imsg);
1922 			else if (do_ref_updates)
1923 				err = begin_ref_updates(client, &imsg);
1924 			else if (do_ref_update)
1925 				err = update_ref(client, proc->repo_path,
1926 				    &imsg);
1927 			if (err)
1928 				log_warnx("uid %d: %s", client->euid, err->msg);
1929 		}
1930 		imsg_free(&imsg);
1931 	}
1932 done:
1933 	if (!shut) {
1934 		gotd_imsg_event_add(iev);
1935 	} else {
1936 		/* This pipe is dead. Remove its event handler */
1937 		event_del(&iev->ev);
1938 		event_loopexit(NULL);
1939 	}
1940 }
1941 
1942 static pid_t
1943 start_child(enum gotd_procid proc_id, const char *repo_path,
1944     char *argv0, const char *confpath, int fd, int daemonize, int verbosity)
1945 {
1946 	char	*argv[11];
1947 	int	 argc = 0;
1948 	pid_t	 pid;
1949 
1950 	switch (pid = fork()) {
1951 	case -1:
1952 		fatal("cannot fork");
1953 	case 0:
1954 		break;
1955 	default:
1956 		close(fd);
1957 		return pid;
1958 	}
1959 
1960 	if (fd != GOTD_FILENO_MSG_PIPE) {
1961 		if (dup2(fd, GOTD_FILENO_MSG_PIPE) == -1)
1962 			fatal("cannot setup imsg fd");
1963 	} else if (fcntl(fd, F_SETFD, 0) == -1)
1964 		fatal("cannot setup imsg fd");
1965 
1966 	argv[argc++] = argv0;
1967 	switch (proc_id) {
1968 	case PROC_LISTEN:
1969 		argv[argc++] = (char *)"-L";
1970 		break;
1971 	case PROC_REPO_READ:
1972 		argv[argc++] = (char *)"-R";
1973 		break;
1974 	case PROC_REPO_WRITE:
1975 		argv[argc++] = (char *)"-W";
1976 		break;
1977 	default:
1978 		fatalx("invalid process id %d", proc_id);
1979 	}
1980 
1981 	argv[argc++] = (char *)"-f";
1982 	argv[argc++] = (char *)confpath;
1983 
1984 	if (repo_path) {
1985 		argv[argc++] = (char *)"-P";
1986 		argv[argc++] = (char *)repo_path;
1987 	}
1988 
1989 	if (!daemonize)
1990 		argv[argc++] = (char *)"-d";
1991 	if (verbosity > 0)
1992 		argv[argc++] = (char *)"-v";
1993 	if (verbosity > 1)
1994 		argv[argc++] = (char *)"-v";
1995 	argv[argc++] = NULL;
1996 
1997 	execvp(argv0, argv);
1998 	fatal("execvp");
1999 }
2000 
2001 static void
2002 start_listener(char *argv0, const char *confpath, int daemonize, int verbosity)
2003 {
2004 	struct gotd_child_proc *proc = &gotd.procs[0];
2005 
2006 	proc->type = PROC_LISTEN;
2007 
2008 	if (socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK,
2009 	    PF_UNSPEC, proc->pipe) == -1)
2010 		fatal("socketpair");
2011 
2012 	proc->pid = start_child(proc->type, NULL, argv0, confpath,
2013 	    proc->pipe[1], daemonize, verbosity);
2014 	imsg_init(&proc->iev.ibuf, proc->pipe[0]);
2015 	proc->iev.handler = gotd_dispatch;
2016 	proc->iev.events = EV_READ;
2017 	proc->iev.handler_arg = NULL;
2018 }
2019 
2020 static void
2021 start_repo_children(struct gotd *gotd, char *argv0, const char *confpath,
2022     int daemonize, int verbosity)
2023 {
2024 	struct gotd_repo *repo = NULL;
2025 	struct gotd_child_proc *proc;
2026 	int i;
2027 
2028 	for (i = 1; i < gotd->nprocs; i++) {
2029 		if (repo == NULL)
2030 			repo = TAILQ_FIRST(&gotd->repos);
2031 		proc = &gotd->procs[i];
2032 		if (i - 1 < gotd->nrepos)
2033 			proc->type = PROC_REPO_READ;
2034 		else
2035 			proc->type = PROC_REPO_WRITE;
2036 		if (strlcpy(proc->repo_name, repo->name,
2037 		    sizeof(proc->repo_name)) >= sizeof(proc->repo_name))
2038 			fatalx("repository name too long: %s", repo->name);
2039 		log_debug("adding repository %s", repo->name);
2040 		if (realpath(repo->path, proc->repo_path) == NULL)
2041 			fatal("%s", repo->path);
2042 		if (socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK,
2043 		    PF_UNSPEC, proc->pipe) == -1)
2044 			fatal("socketpair");
2045 		proc->pid = start_child(proc->type, proc->repo_path, argv0,
2046 		    confpath, proc->pipe[1], daemonize, verbosity);
2047 		imsg_init(&proc->iev.ibuf, proc->pipe[0]);
2048 		log_debug("proc %s %s is on fd %d",
2049 		    gotd_proc_names[proc->type], proc->repo_path,
2050 		    proc->pipe[0]);
2051 		proc->iev.handler = gotd_dispatch;
2052 		proc->iev.events = EV_READ;
2053 		proc->iev.handler_arg = NULL;
2054 		event_set(&proc->iev.ev, proc->iev.ibuf.fd, EV_READ,
2055 		    gotd_dispatch, &proc->iev);
2056 
2057 		repo = TAILQ_NEXT(repo, entry);
2058 	}
2059 }
2060 
2061 static void
2062 apply_unveil_repo_readonly(const char *repo_path)
2063 {
2064 	if (unveil(repo_path, "r") == -1)
2065 		fatal("unveil %s", repo_path);
2066 
2067 	if (unveil(NULL, NULL) == -1)
2068 		fatal("unveil");
2069 }
2070 
2071 static void
2072 apply_unveil(void)
2073 {
2074 	struct gotd_repo *repo;
2075 
2076 	TAILQ_FOREACH(repo, &gotd.repos, entry) {
2077 		if (unveil(repo->path, "rwc") == -1)
2078 			fatal("unveil %s", repo->path);
2079 	}
2080 
2081 	if (unveil(GOT_TMPDIR_STR, "rwc") == -1)
2082 		fatal("unveil %s", GOT_TMPDIR_STR);
2083 
2084 	if (unveil(NULL, NULL) == -1)
2085 		fatal("unveil");
2086 }
2087 
2088 int
2089 main(int argc, char **argv)
2090 {
2091 	const struct got_error *error = NULL;
2092 	int ch, fd = -1, daemonize = 1, verbosity = 0, noaction = 0;
2093 	const char *confpath = GOTD_CONF_PATH;
2094 	char *argv0 = argv[0];
2095 	char title[2048];
2096 	gid_t groups[NGROUPS_MAX];
2097 	int ngroups = NGROUPS_MAX;
2098 	struct passwd *pw = NULL;
2099 	struct group *gr = NULL;
2100 	char *repo_path = NULL;
2101 	enum gotd_procid proc_id = PROC_GOTD;
2102 	struct event evsigint, evsigterm, evsighup, evsigusr1;
2103 	int *pack_fds = NULL, *temp_fds = NULL;
2104 
2105 	log_init(1, LOG_DAEMON); /* Log to stderr until daemonized. */
2106 
2107 	while ((ch = getopt(argc, argv, "df:LnP:RvW")) != -1) {
2108 		switch (ch) {
2109 		case 'd':
2110 			daemonize = 0;
2111 			break;
2112 		case 'f':
2113 			confpath = optarg;
2114 			break;
2115 		case 'L':
2116 			proc_id = PROC_LISTEN;
2117 			break;
2118 		case 'n':
2119 			noaction = 1;
2120 			break;
2121 		case 'P':
2122 			repo_path = realpath(optarg, NULL);
2123 			if (repo_path == NULL)
2124 				fatal("realpath '%s'", optarg);
2125 			break;
2126 		case 'R':
2127 			proc_id = PROC_REPO_READ;
2128 			break;
2129 		case 'v':
2130 			if (verbosity < 3)
2131 				verbosity++;
2132 			break;
2133 		case 'W':
2134 			proc_id = PROC_REPO_WRITE;
2135 			break;
2136 		default:
2137 			usage();
2138 		}
2139 	}
2140 
2141 	argc -= optind;
2142 	argv += optind;
2143 
2144 	if (argc != 0)
2145 		usage();
2146 
2147 	if (geteuid())
2148 		fatalx("need root privileges");
2149 
2150 	log_init(daemonize ? 0 : 1, LOG_DAEMON);
2151 	log_setverbose(verbosity);
2152 
2153 	if (parse_config(confpath, proc_id, &gotd) != 0)
2154 		return 1;
2155 
2156 	if (proc_id == PROC_GOTD &&
2157 	    (gotd.nrepos == 0 || TAILQ_EMPTY(&gotd.repos)))
2158 		fatalx("no repository defined in configuration file");
2159 
2160 	pw = getpwnam(gotd.user_name);
2161 	if (pw == NULL)
2162 		fatal("getpwuid: user %s not found", gotd.user_name);
2163 
2164 	if (pw->pw_uid == 0) {
2165 		fatalx("cannot run %s as %s: the user running %s "
2166 		    "must not be the superuser",
2167 		    getprogname(), pw->pw_name, getprogname());
2168 	}
2169 
2170 	if (getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups) == -1)
2171 		log_warnx("group membership list truncated");
2172 
2173 	gr = match_group(groups, ngroups, gotd.unix_group_name);
2174 	if (gr == NULL) {
2175 		fatalx("cannot start %s: the user running %s "
2176 		    "must be a secondary member of group %s",
2177 		    getprogname(), getprogname(), gotd.unix_group_name);
2178 	}
2179 	if (gr->gr_gid == pw->pw_gid) {
2180 		fatalx("cannot start %s: the user running %s "
2181 		    "must be a secondary member of group %s, but "
2182 		    "%s is the user's primary group",
2183 		    getprogname(), getprogname(), gotd.unix_group_name,
2184 		    gotd.unix_group_name);
2185 	}
2186 
2187 	if (proc_id == PROC_LISTEN &&
2188 	    !got_path_is_absolute(gotd.unix_socket_path))
2189 		fatalx("bad unix socket path \"%s\": must be an absolute path",
2190 		    gotd.unix_socket_path);
2191 
2192 	if (noaction)
2193 		return 0;
2194 
2195 	if (proc_id == PROC_GOTD) {
2196 		gotd.pid = getpid();
2197 		snprintf(title, sizeof(title), "%s", gotd_proc_names[proc_id]);
2198 		/*
2199 		 * Start a listener and repository readers/writers.
2200 		 * XXX For now, use one reader and one writer per repository.
2201 		 * This should be changed to N readers + M writers.
2202 		 */
2203 		gotd.nprocs = 1 + gotd.nrepos * 2;
2204 		gotd.procs = calloc(gotd.nprocs, sizeof(*gotd.procs));
2205 		if (gotd.procs == NULL)
2206 			fatal("calloc");
2207 		start_listener(argv0, confpath, daemonize, verbosity);
2208 		start_repo_children(&gotd, argv0, confpath, daemonize,
2209 		    verbosity);
2210 		arc4random_buf(&clients_hash_key, sizeof(clients_hash_key));
2211 		if (daemonize && daemon(1, 0) == -1)
2212 			fatal("daemon");
2213 	} else if (proc_id == PROC_LISTEN) {
2214 		snprintf(title, sizeof(title), "%s", gotd_proc_names[proc_id]);
2215 		if (verbosity) {
2216 			log_info("socket: %s", gotd.unix_socket_path);
2217 			log_info("user: %s", pw->pw_name);
2218 			log_info("secondary group: %s", gr->gr_name);
2219 		}
2220 
2221 		fd = unix_socket_listen(gotd.unix_socket_path, pw->pw_uid,
2222 		    gr->gr_gid);
2223 		if (fd == -1) {
2224 			fatal("cannot listen on unix socket %s",
2225 			    gotd.unix_socket_path);
2226 		}
2227 		if (daemonize && daemon(0, 0) == -1)
2228 			fatal("daemon");
2229 	} else if (proc_id == PROC_REPO_READ || proc_id == PROC_REPO_WRITE) {
2230 		error = got_repo_pack_fds_open(&pack_fds);
2231 		if (error != NULL)
2232 			fatalx("cannot open pack tempfiles: %s", error->msg);
2233 		error = got_repo_temp_fds_open(&temp_fds);
2234 		if (error != NULL)
2235 			fatalx("cannot open pack tempfiles: %s", error->msg);
2236 		if (repo_path == NULL)
2237 			fatalx("repository path not specified");
2238 		snprintf(title, sizeof(title), "%s %s",
2239 		    gotd_proc_names[proc_id], repo_path);
2240 		if (daemonize && daemon(0, 0) == -1)
2241 			fatal("daemon");
2242 	} else
2243 		fatal("invalid process id %d", proc_id);
2244 
2245 	setproctitle("%s", title);
2246 	log_procinit(title);
2247 
2248 	/* Drop root privileges. */
2249 	if (setgid(pw->pw_gid) == -1)
2250 		fatal("setgid %d failed", pw->pw_gid);
2251 	if (setuid(pw->pw_uid) == -1)
2252 		fatal("setuid %d failed", pw->pw_uid);
2253 
2254 	event_init();
2255 
2256 	switch (proc_id) {
2257 	case PROC_GOTD:
2258 #ifndef PROFILE
2259 		if (pledge("stdio rpath wpath cpath proc getpw sendfd recvfd "
2260 		    "fattr flock unix unveil", NULL) == -1)
2261 			err(1, "pledge");
2262 #endif
2263 		break;
2264 	case PROC_LISTEN:
2265 #ifndef PROFILE
2266 		if (pledge("stdio sendfd unix", NULL) == -1)
2267 			err(1, "pledge");
2268 #endif
2269 		listen_main(title, fd);
2270 		/* NOTREACHED */
2271 		break;
2272 	case PROC_REPO_READ:
2273 #ifndef PROFILE
2274 		if (pledge("stdio rpath recvfd unveil", NULL) == -1)
2275 			err(1, "pledge");
2276 #endif
2277 		apply_unveil_repo_readonly(repo_path);
2278 		repo_read_main(title, repo_path, pack_fds, temp_fds);
2279 		/* NOTREACHED */
2280 		exit(0);
2281 	case PROC_REPO_WRITE:
2282 #ifndef PROFILE
2283 		if (pledge("stdio rpath recvfd unveil", NULL) == -1)
2284 			err(1, "pledge");
2285 #endif
2286 		apply_unveil_repo_readonly(repo_path);
2287 		repo_write_main(title, repo_path, pack_fds, temp_fds);
2288 		/* NOTREACHED */
2289 		exit(0);
2290 	default:
2291 		fatal("invalid process id %d", proc_id);
2292 	}
2293 
2294 	if (proc_id != PROC_GOTD)
2295 		fatal("invalid process id %d", proc_id);
2296 
2297 	apply_unveil();
2298 
2299 	signal_set(&evsigint, SIGINT, gotd_sighdlr, NULL);
2300 	signal_set(&evsigterm, SIGTERM, gotd_sighdlr, NULL);
2301 	signal_set(&evsighup, SIGHUP, gotd_sighdlr, NULL);
2302 	signal_set(&evsigusr1, SIGUSR1, gotd_sighdlr, NULL);
2303 	signal(SIGPIPE, SIG_IGN);
2304 
2305 	signal_add(&evsigint, NULL);
2306 	signal_add(&evsigterm, NULL);
2307 	signal_add(&evsighup, NULL);
2308 	signal_add(&evsigusr1, NULL);
2309 
2310 	gotd_imsg_event_add(&gotd.procs[0].iev);
2311 
2312 	event_dispatch();
2313 
2314 	if (pack_fds)
2315 		got_repo_pack_fds_close(pack_fds);
2316 	free(repo_path);
2317 	return 0;
2318 }