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