Gotweb

Blob

Date:: Thu Nov 17 21:39:04 2022 UTC
Message:: implement per-repository read/write authorization rules in gotd ok op@
Actions:: History | Blame | Raw File
1 /*
2  * Copyright (c) 2022 Stefan Sperling <stsp@openbsd.org>
3  * Copyright (c) 2015 Ted Unangst <tedu@openbsd.org>
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 #include <sys/queue.h>
19 #include <sys/tree.h>
20 #include <sys/time.h>
21 #include <sys/types.h>
22 #include <sys/stat.h>
23 #include <sys/socket.h>
24 #include <sys/un.h>
25 #include <sys/wait.h>
26 
27 #include <fcntl.h>
28 #include <err.h>
29 #include <errno.h>
30 #include <event.h>
31 #include <limits.h>
32 #include <pwd.h>
33 #include <grp.h>
34 #include <imsg.h>
35 #include <sha1.h>
36 #include <signal.h>
37 #include <siphash.h>
38 #include <stdarg.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <syslog.h>
43 #include <unistd.h>
44 
45 #include "got_error.h"
46 #include "got_opentemp.h"
47 #include "got_path.h"
48 #include "got_repository.h"
49 #include "got_object.h"
50 #include "got_reference.h"
51 
52 #include "got_lib_delta.h"
53 #include "got_lib_object.h"
54 #include "got_lib_object_cache.h"
55 #include "got_lib_sha1.h"
56 #include "got_lib_gitproto.h"
57 #include "got_lib_pack.h"
58 #include "got_lib_repository.h"
59 
60 #include "gotd.h"
61 #include "log.h"
62 #include "auth.h"
63 #include "repo_read.h"
64 #include "repo_write.h"
65 
66 #ifndef nitems
67 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
68 #endif
69 
70 struct gotd_client {
71 	STAILQ_ENTRY(gotd_client)	 entry;
72 	enum gotd_client_state		 state;
73 	struct gotd_client_capability	*capabilities;
74 	size_t				 ncapa_alloc;
75 	size_t				 ncapabilities;
76 	uint32_t			 id;
77 	int				 fd;
78 	int				 delta_cache_fd;
79 	struct gotd_imsgev		 iev;
80 	struct event			 tmo;
81 	uid_t				 euid;
82 	gid_t				 egid;
83 	struct gotd_child_proc		*repo_read;
84 	struct gotd_child_proc		*repo_write;
85 	char				*packfile_path;
86 	char				*packidx_path;
87 	int				 nref_updates;
88 };
89 STAILQ_HEAD(gotd_clients, gotd_client);
90 
91 static struct gotd_clients gotd_clients[GOTD_CLIENT_TABLE_SIZE];
92 static SIPHASH_KEY clients_hash_key;
93 volatile int client_cnt;
94 static struct timeval timeout = { 3600, 0 };
95 static int inflight;
96 static struct gotd gotd;
97 
98 void gotd_sighdlr(int sig, short event, void *arg);
99 static void gotd_shutdown(void);
100 
101 __dead static void
102 usage()
103 {
104 	fprintf(stderr, "usage: %s [-dv] [-f config-file]\n", getprogname());
105 	exit(1);
106 }
107 
108 static int
109 unix_socket_listen(const char *unix_socket_path, uid_t uid, gid_t gid)
110 {
111 	struct sockaddr_un sun;
112 	int fd = -1;
113 	mode_t old_umask, mode;
114 
115 	fd = socket(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK| SOCK_CLOEXEC, 0);
116 	if (fd == -1) {
117 		log_warn("socket");
118 		return -1;
119 	}
120 
121 	sun.sun_family = AF_UNIX;
122 	if (strlcpy(sun.sun_path, unix_socket_path,
123 	    sizeof(sun.sun_path)) >= sizeof(sun.sun_path)) {
124 		log_warnx("%s: name too long", unix_socket_path);
125 		close(fd);
126 		return -1;
127 	}
128 
129 	if (unlink(unix_socket_path) == -1) {
130 		if (errno != ENOENT) {
131 			log_warn("unlink %s", unix_socket_path);
132 			close(fd);
133 			return -1;
134 		}
135 	}
136 
137 	old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);
138 	mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP;
139 
140 	if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
141 		log_warn("bind: %s", unix_socket_path);
142 		close(fd);
143 		umask(old_umask);
144 		return -1;
145 	}
146 
147 	umask(old_umask);
148 
149 	if (chmod(unix_socket_path, mode) == -1) {
150 		log_warn("chmod %o %s", mode, unix_socket_path);
151 		close(fd);
152 		unlink(unix_socket_path);
153 		return -1;
154 	}
155 
156 	if (chown(unix_socket_path, uid, gid) == -1) {
157 		log_warn("chown %s uid=%d gid=%d", unix_socket_path, uid, gid);
158 		close(fd);
159 		unlink(unix_socket_path);
160 		return -1;
161 	}
162 
163 	if (listen(fd, GOTD_UNIX_SOCKET_BACKLOG) == -1) {
164 		log_warn("listen");
165 		close(fd);
166 		unlink(unix_socket_path);
167 		return -1;
168 	}
169 
170 	return fd;
171 }
172 
173 static struct group *
174 match_group(gid_t *groups, int ngroups, const char *unix_group_name)
175 {
176 	struct group *gr;
177 	int i;
178 
179 	for (i = 0; i < ngroups; i++) {
180 		gr = getgrgid(groups[i]);
181 		if (gr == NULL) {
182 			log_warn("getgrgid %d", groups[i]);
183 			continue;
184 		}
185 		if (strcmp(gr->gr_name, unix_group_name) == 0)
186 			return gr;
187 	}
188 
189 	return NULL;
190 }
191 
192 static int
193 accept_reserve(int fd, struct sockaddr *addr, socklen_t *addrlen,
194     int reserve, volatile int *counter)
195 {
196 	int ret;
197 
198 	if (getdtablecount() + reserve +
199 	    ((*counter + 1) * GOTD_FD_NEEDED) >= getdtablesize()) {
200 		log_debug("inflight fds exceeded");
201 		errno = EMFILE;
202 		return -1;
203 	}
204 
205 	if ((ret = accept4(fd, addr, addrlen,
206 	    SOCK_NONBLOCK | SOCK_CLOEXEC)) > -1) {
207 		(*counter)++;
208 	}
209 
210 	return ret;
211 }
212 
213 static uint64_t
214 client_hash(uint32_t client_id)
215 {
216 	return SipHash24(&clients_hash_key, &client_id, sizeof(client_id));
217 }
218 
219 static void
220 add_client(struct gotd_client *client)
221 {
222 	uint64_t slot = client_hash(client->id) % nitems(gotd_clients);
223 	STAILQ_INSERT_HEAD(&gotd_clients[slot], client, entry);
224 	client_cnt++;
225 }
226 
227 static struct gotd_client *
228 find_client(uint32_t client_id)
229 {
230 	uint64_t slot;
231 	struct gotd_client *c;
232 
233 	slot = client_hash(client_id) % nitems(gotd_clients);
234 	STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
235 		if (c->id == client_id)
236 			return c;
237 	}
238 
239 	return NULL;
240 }
241 
242 static uint32_t
243 get_client_id(void)
244 {
245 	int duplicate = 0;
246 	uint32_t id;
247 
248 	do {
249 		id = arc4random();
250 		duplicate = (find_client(id) != NULL);
251 	} while (duplicate || id == 0);
252 
253 	return id;
254 }
255 
256 static struct gotd_child_proc *
257 get_client_proc(struct gotd_client *client)
258 {
259 	if (client->repo_read && client->repo_write) {
260 		fatalx("uid %d is reading and writing in the same session",
261 		    client->euid);
262 		/* NOTREACHED */
263 	}
264 
265 	if (client->repo_read)
266 		return client->repo_read;
267 	else if (client->repo_write)
268 		return client->repo_write;
269 
270 	return NULL;
271 }
272 
273 static int
274 client_is_reading(struct gotd_client *client)
275 {
276 	return client->repo_read != NULL;
277 }
278 
279 static int
280 client_is_writing(struct gotd_client *client)
281 {
282 	return client->repo_write != NULL;
283 }
284 
285 static const struct got_error *
286 ensure_client_is_reading(struct gotd_client *client)
287 {
288 	if (!client_is_reading(client)) {
289 		return got_error_fmt(GOT_ERR_BAD_PACKET,
290 		    "uid %d made a read-request but is not reading from "
291 		    "a repository", client->euid);
292 	}
293 
294 	return NULL;
295 }
296 
297 static const struct got_error *
298 ensure_client_is_writing(struct gotd_client *client)
299 {
300 	if (!client_is_writing(client)) {
301 		return got_error_fmt(GOT_ERR_BAD_PACKET,
302 		    "uid %d made a write-request but is not writing to "
303 		    "a repository", client->euid);
304 	}
305 
306 	return NULL;
307 }
308 
309 static const struct got_error *
310 ensure_client_is_not_writing(struct gotd_client *client)
311 {
312 	if (client_is_writing(client)) {
313 		return got_error_fmt(GOT_ERR_BAD_PACKET,
314 		    "uid %d made a read-request but is writing to "
315 		    "a repository", client->euid);
316 	}
317 
318 	return NULL;
319 }
320 
321 static const struct got_error *
322 ensure_client_is_not_reading(struct gotd_client *client)
323 {
324 	if (client_is_reading(client)) {
325 		return got_error_fmt(GOT_ERR_BAD_PACKET,
326 		    "uid %d made a write-request but is reading from "
327 		    "a repository", client->euid);
328 	}
329 
330 	return NULL;
331 }
332 
333 static void
334 disconnect(struct gotd_client *client)
335 {
336 	struct gotd_imsg_disconnect idisconnect;
337 	struct gotd_child_proc *proc = get_client_proc(client);
338 	uint64_t slot;
339 
340 	log_debug("uid %d: disconnecting", client->euid);
341 
342 	idisconnect.client_id = client->id;
343 	if (proc) {
344 		if (gotd_imsg_compose_event(&proc->iev,
345 		    GOTD_IMSG_DISCONNECT, PROC_GOTD, -1,
346 		    &idisconnect, sizeof(idisconnect)) == -1)
347 			log_warn("imsg compose DISCONNECT");
348 	}
349 	slot = client_hash(client->id) % nitems(gotd_clients);
350 	STAILQ_REMOVE(&gotd_clients[slot], client, gotd_client, entry);
351 	imsg_clear(&client->iev.ibuf);
352 	event_del(&client->iev.ev);
353 	evtimer_del(&client->tmo);
354 	close(client->fd);
355 	if (client->delta_cache_fd != -1)
356 		close(client->delta_cache_fd);
357 	if (client->packfile_path) {
358 		if (unlink(client->packfile_path) == -1 && errno != ENOENT)
359 			log_warn("unlink %s: ", client->packfile_path);
360 		free(client->packfile_path);
361 	}
362 	if (client->packidx_path) {
363 		if (unlink(client->packidx_path) == -1 && errno != ENOENT)
364 			log_warn("unlink %s: ", client->packidx_path);
365 		free(client->packidx_path);
366 	}
367 	free(client->capabilities);
368 	free(client);
369 	inflight--;
370 	client_cnt--;
371 }
372 
373 static void
374 disconnect_on_error(struct gotd_client *client, const struct got_error *err)
375 {
376 	struct imsgbuf ibuf;
377 
378 	log_warnx("uid %d: %s", client->euid, err->msg);
379 	if (err->code != GOT_ERR_EOF) {
380 		imsg_init(&ibuf, client->fd);
381 		gotd_imsg_send_error(&ibuf, 0, PROC_GOTD, err);
382 		imsg_clear(&ibuf);
383 	}
384 	disconnect(client);
385 }
386 
387 static const struct got_error *
388 send_repo_info(struct gotd_imsgev *iev, struct gotd_repo *repo)
389 {
390 	const struct got_error *err = NULL;
391 	struct gotd_imsg_info_repo irepo;
392 
393 	memset(&irepo, 0, sizeof(irepo));
394 
395 	if (strlcpy(irepo.repo_name, repo->name, sizeof(irepo.repo_name))
396 	    >= sizeof(irepo.repo_name))
397 		return got_error_msg(GOT_ERR_NO_SPACE, "repo name too long");
398 	if (strlcpy(irepo.repo_path, repo->path, sizeof(irepo.repo_path))
399 	    >= sizeof(irepo.repo_path))
400 		return got_error_msg(GOT_ERR_NO_SPACE, "repo path too long");
401 
402 	if (gotd_imsg_compose_event(iev, GOTD_IMSG_INFO_REPO, PROC_GOTD, -1,
403 	    &irepo, sizeof(irepo)) == -1) {
404 		err = got_error_from_errno("imsg compose INFO_REPO");
405 		if (err)
406 			return err;
407 	}
408 
409 	return NULL;
410 }
411 
412 static const struct got_error *
413 send_capability(struct gotd_client_capability *capa, struct gotd_imsgev* iev)
414 {
415 	const struct got_error *err = NULL;
416 	struct gotd_imsg_capability icapa;
417 	size_t len;
418 	struct ibuf *wbuf;
419 
420 	memset(&icapa, 0, sizeof(icapa));
421 
422 	icapa.key_len = strlen(capa->key);
423 	len = sizeof(icapa) + icapa.key_len;
424 	if (capa->value) {
425 		icapa.value_len = strlen(capa->value);
426 		len += icapa.value_len;
427 	}
428 
429 	wbuf = imsg_create(&iev->ibuf, GOTD_IMSG_CAPABILITY, 0, 0, len);
430 	if (wbuf == NULL) {
431 		err = got_error_from_errno("imsg_create CAPABILITY");
432 		return err;
433 	}
434 
435 	if (imsg_add(wbuf, &icapa, sizeof(icapa)) == -1)
436 		return got_error_from_errno("imsg_add CAPABILITY");
437 	if (imsg_add(wbuf, capa->key, icapa.key_len) == -1)
438 		return got_error_from_errno("imsg_add CAPABILITY");
439 	if (capa->value) {
440 		if (imsg_add(wbuf, capa->value, icapa.value_len) == -1)
441 			return got_error_from_errno("imsg_add CAPABILITY");
442 	}
443 
444 	wbuf->fd = -1;
445 	imsg_close(&iev->ibuf, wbuf);
446 
447 	gotd_imsg_event_add(iev);
448 
449 	return NULL;
450 }
451 
452 static const struct got_error *
453 send_client_info(struct gotd_imsgev *iev, struct gotd_client *client)
454 {
455 	const struct got_error *err = NULL;
456 	struct gotd_imsg_info_client iclient;
457 	struct gotd_child_proc *proc;
458 	size_t i;
459 
460 	memset(&iclient, 0, sizeof(iclient));
461 	iclient.euid = client->euid;
462 	iclient.egid = client->egid;
463 
464 	proc = get_client_proc(client);
465 	if (proc) {
466 		if (strlcpy(iclient.repo_name, proc->chroot_path,
467 		    sizeof(iclient.repo_name)) >= sizeof(iclient.repo_name)) {
468 			return got_error_msg(GOT_ERR_NO_SPACE,
469 			    "repo name too long");
470 		}
471 		if (client_is_writing(client))
472 			iclient.is_writing = 1;
473 	}
474 
475 	iclient.state = client->state;
476 	iclient.ncapabilities = client->ncapabilities;
477 
478 	if (gotd_imsg_compose_event(iev, GOTD_IMSG_INFO_CLIENT, PROC_GOTD, -1,
479 	    &iclient, sizeof(iclient)) == -1) {
480 		err = got_error_from_errno("imsg compose INFO_CLIENT");
481 		if (err)
482 			return err;
483 	}
484 
485 	for (i = 0; i < client->ncapabilities; i++) {
486 		struct gotd_client_capability *capa;
487 		capa = &client->capabilities[i];
488 		err = send_capability(capa, iev);
489 		if (err)
490 			return err;
491 	}
492 
493 	return NULL;
494 }
495 
496 static const struct got_error *
497 send_info(struct gotd_client *client)
498 {
499 	const struct got_error *err = NULL;
500 	struct gotd_imsg_info info;
501 	uint64_t slot;
502 	struct gotd_repo *repo;
503 
504 	info.pid = gotd.pid;
505 	info.verbosity = gotd.verbosity;
506 	info.nrepos = gotd.nrepos;
507 	info.nclients = client_cnt - 1;
508 
509 	if (gotd_imsg_compose_event(&client->iev, GOTD_IMSG_INFO, PROC_GOTD, -1,
510 	    &info, sizeof(info)) == -1) {
511 		err = got_error_from_errno("imsg compose INFO");
512 		if (err)
513 			return err;
514 	}
515 
516 	TAILQ_FOREACH(repo, &gotd.repos, entry) {
517 		err = send_repo_info(&client->iev, repo);
518 		if (err)
519 			return err;
520 	}
521 
522 	for (slot = 0; slot < nitems(gotd_clients); slot++) {
523 		struct gotd_client *c;
524 		STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
525 			if (c->id == client->id)
526 				continue;
527 			err = send_client_info(&client->iev, c);
528 			if (err)
529 				return err;
530 		}
531 	}
532 
533 	return NULL;
534 }
535 
536 static const struct got_error *
537 stop_gotd(struct gotd_client *client)
538 {
539 
540 	if (client->euid != 0)
541 		return got_error_set_errno(EPERM, "stop");
542 
543 	gotd_shutdown();
544 	/* NOTREACHED */
545 	return NULL;
546 }
547 
548 static struct gotd_repo *
549 find_repo_by_name(const char *repo_name)
550 {
551 	struct gotd_repo *repo;
552 	size_t namelen;
553 
554 	TAILQ_FOREACH(repo, &gotd.repos, entry) {
555 		namelen = strlen(repo->name);
556 		if (strncmp(repo->name, repo_name, namelen) != 0)
557 			continue;
558 		if (repo_name[namelen] == '\0' ||
559 		    strcmp(&repo_name[namelen], ".git") == 0)
560 			return repo;
561 	}
562 
563 	return NULL;
564 }
565 
566 static struct gotd_child_proc *
567 find_proc_by_repo_name(enum gotd_procid proc_id, const char *repo_name)
568 {
569 	struct gotd_child_proc *proc;
570 	int i;
571 	size_t namelen;
572 
573 	for (i = 0; i < gotd.nprocs; i++) {
574 		proc = &gotd.procs[i];
575 		if (proc->type != proc_id)
576 			continue;
577 		namelen = strlen(proc->repo_name);
578 		if (strncmp(proc->repo_name, repo_name, namelen) != 0)
579 			continue;
580 		if (repo_name[namelen] == '\0' ||
581 		    strcmp(&repo_name[namelen], ".git") == 0)
582 			return proc;
583 	}
584 
585 	return NULL;
586 }
587 
588 static struct gotd_child_proc *
589 find_proc_by_fd(int fd)
590 {
591 	struct gotd_child_proc *proc;
592 	int i;
593 
594 	for (i = 0; i < gotd.nprocs; i++) {
595 		proc = &gotd.procs[i];
596 		if (proc->iev.ibuf.fd == fd)
597 			return proc;
598 	}
599 
600 	return NULL;
601 }
602 
603 static const struct got_error *
604 forward_list_refs_request(struct gotd_client *client, struct imsg *imsg)
605 {
606 	const struct got_error *err;
607 	struct gotd_imsg_list_refs ireq;
608 	struct gotd_imsg_list_refs_internal ilref;
609 	struct gotd_repo *repo = NULL;
610 	struct gotd_child_proc *proc = NULL;
611 	size_t datalen;
612 	int fd = -1;
613 
614 	log_debug("list-refs request from uid %d", client->euid);
615 
616 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
617 	if (datalen != sizeof(ireq))
618 		return got_error(GOT_ERR_PRIVSEP_LEN);
619 
620 	memcpy(&ireq, imsg->data, datalen);
621 
622 	memset(&ilref, 0, sizeof(ilref));
623 	ilref.client_id = client->id;
624 
625 	if (ireq.client_is_reading) {
626 		err = ensure_client_is_not_writing(client);
627 		if (err)
628 			return err;
629 		repo = find_repo_by_name(ireq.repo_name);
630 		if (repo == NULL)
631 			return got_error(GOT_ERR_NOT_GIT_REPO);
632 		err = gotd_auth_check(&repo->rules, repo->name,
633 		    gotd.groups, gotd.ngroups, client->euid, client->egid,
634 		    GOTD_AUTH_READ);
635 		if (err)
636 			return err;
637 		client->repo_read = find_proc_by_repo_name(PROC_REPO_READ,
638 		    ireq.repo_name);
639 		if (client->repo_read == NULL)
640 			return got_error(GOT_ERR_NOT_GIT_REPO);
641 	} else {
642 		err = ensure_client_is_not_reading(client);
643 		if (err)
644 			return err;
645 		repo = find_repo_by_name(ireq.repo_name);
646 		if (repo == NULL)
647 			return got_error(GOT_ERR_NOT_GIT_REPO);
648 		err = gotd_auth_check(&repo->rules, repo->name,
649 		    gotd.groups, gotd.ngroups, client->euid, client->egid,
650 		    GOTD_AUTH_READ | GOTD_AUTH_WRITE);
651 		if (err)
652 			return err;
653 		client->repo_write = find_proc_by_repo_name(PROC_REPO_WRITE,
654 		    ireq.repo_name);
655 		if (client->repo_write == NULL)
656 			return got_error(GOT_ERR_NOT_GIT_REPO);
657 	}
658 
659 	fd = dup(client->fd);
660 	if (fd == -1)
661 		return got_error_from_errno("dup");
662 
663 	proc = get_client_proc(client);
664 	if (proc == NULL)
665 		fatalx("no process found for uid %d", client->euid);
666 	if (gotd_imsg_compose_event(&proc->iev,
667 	    GOTD_IMSG_LIST_REFS_INTERNAL, PROC_GOTD, fd,
668 	    &ilref, sizeof(ilref)) == -1) {
669 		err = got_error_from_errno("imsg compose WANT");
670 		close(fd);
671 		return err;
672 	}
673 
674 	return NULL;
675 }
676 
677 static const struct got_error *
678 forward_want(struct gotd_client *client, struct imsg *imsg)
679 {
680 	struct gotd_imsg_want ireq;
681 	struct gotd_imsg_want iwant;
682 	size_t datalen;
683 
684 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
685 	if (datalen != sizeof(ireq))
686 		return got_error(GOT_ERR_PRIVSEP_LEN);
687 
688 	memcpy(&ireq, imsg->data, datalen);
689 
690 	memset(&iwant, 0, sizeof(iwant));
691 	memcpy(iwant.object_id, ireq.object_id, SHA1_DIGEST_LENGTH);
692 	iwant.client_id = client->id;
693 
694 	if (gotd_imsg_compose_event(&client->repo_read->iev, GOTD_IMSG_WANT,
695 	    PROC_GOTD, -1, &iwant, sizeof(iwant)) == -1)
696 		return got_error_from_errno("imsg compose WANT");
697 
698 	return NULL;
699 }
700 
701 static const struct got_error *
702 forward_ref_update(struct gotd_client *client, struct imsg *imsg)
703 {
704 	const struct got_error *err = NULL;
705 	struct gotd_imsg_ref_update ireq;
706 	struct gotd_imsg_ref_update *iref = NULL;
707 	size_t datalen;
708 
709 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
710 	if (datalen < sizeof(ireq))
711 		return got_error(GOT_ERR_PRIVSEP_LEN);
712 	memcpy(&ireq, imsg->data, sizeof(ireq));
713 	if (datalen != sizeof(ireq) + ireq.name_len)
714 		return got_error(GOT_ERR_PRIVSEP_LEN);
715 
716 	iref = malloc(datalen);
717 	if (iref == NULL)
718 		return got_error_from_errno("malloc");
719 	memcpy(iref, imsg->data, datalen);
720 
721 	iref->client_id = client->id;
722 	if (gotd_imsg_compose_event(&client->repo_write->iev,
723 	    GOTD_IMSG_REF_UPDATE, PROC_GOTD, -1, iref, datalen) == -1)
724 		err = got_error_from_errno("imsg compose REF_UPDATE");
725 	free(iref);
726 	return err;
727 }
728 
729 static const struct got_error *
730 forward_have(struct gotd_client *client, struct imsg *imsg)
731 {
732 	struct gotd_imsg_have ireq;
733 	struct gotd_imsg_have ihave;
734 	size_t datalen;
735 
736 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
737 	if (datalen != sizeof(ireq))
738 		return got_error(GOT_ERR_PRIVSEP_LEN);
739 
740 	memcpy(&ireq, imsg->data, datalen);
741 
742 	memset(&ihave, 0, sizeof(ihave));
743 	memcpy(ihave.object_id, ireq.object_id, SHA1_DIGEST_LENGTH);
744 	ihave.client_id = client->id;
745 
746 	if (gotd_imsg_compose_event(&client->repo_read->iev, GOTD_IMSG_HAVE,
747 	    PROC_GOTD, -1, &ihave, sizeof(ihave)) == -1)
748 		return got_error_from_errno("imsg compose HAVE");
749 
750 	return NULL;
751 }
752 
753 static int
754 client_has_capability(struct gotd_client *client, const char *capastr)
755 {
756 	struct gotd_client_capability *capa;
757 	size_t i;
758 
759 	if (client->ncapabilities == 0)
760 		return 0;
761 
762 	for (i = 0; i < client->ncapabilities; i++) {
763 		capa = &client->capabilities[i];
764 		if (strcmp(capa->key, capastr) == 0)
765 			return 1;
766 	}
767 
768 	return 0;
769 }
770 
771 static const struct got_error *
772 recv_capabilities(struct gotd_client *client, struct imsg *imsg)
773 {
774 	struct gotd_imsg_capabilities icapas;
775 	size_t datalen;
776 
777 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
778 	if (datalen != sizeof(icapas))
779 		return got_error(GOT_ERR_PRIVSEP_LEN);
780 	memcpy(&icapas, imsg->data, sizeof(icapas));
781 
782 	client->ncapa_alloc = icapas.ncapabilities;
783 	client->capabilities = calloc(client->ncapa_alloc,
784 	    sizeof(*client->capabilities));
785 	if (client->capabilities == NULL) {
786 		client->ncapa_alloc = 0;
787 		return got_error_from_errno("calloc");
788 	}
789 
790 	log_debug("expecting %zu capabilities from uid %d",
791 	    client->ncapa_alloc, client->euid);
792 	return NULL;
793 }
794 
795 static const struct got_error *
796 recv_capability(struct gotd_client *client, struct imsg *imsg)
797 {
798 	struct gotd_imsg_capability icapa;
799 	struct gotd_client_capability *capa;
800 	size_t datalen;
801 	char *key, *value = NULL;
802 
803 	if (client->capabilities == NULL ||
804 	    client->ncapabilities >= client->ncapa_alloc) {
805 		return got_error_msg(GOT_ERR_BAD_REQUEST,
806 		    "unexpected capability received");
807 	}
808 
809 	memset(&icapa, 0, sizeof(icapa));
810 
811 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
812 	if (datalen < sizeof(icapa))
813 		return got_error(GOT_ERR_PRIVSEP_LEN);
814 	memcpy(&icapa, imsg->data, sizeof(icapa));
815 
816 	if (datalen != sizeof(icapa) + icapa.key_len + icapa.value_len)
817 		return got_error(GOT_ERR_PRIVSEP_LEN);
818 
819 	key = malloc(icapa.key_len + 1);
820 	if (key == NULL)
821 		return got_error_from_errno("malloc");
822 	if (icapa.value_len > 0) {
823 		value = malloc(icapa.value_len + 1);
824 		if (value == NULL) {
825 			free(key);
826 			return got_error_from_errno("malloc");
827 		}
828 	}
829 
830 	memcpy(key, imsg->data + sizeof(icapa), icapa.key_len);
831 	key[icapa.key_len] = '\0';
832 	if (value) {
833 		memcpy(value, imsg->data + sizeof(icapa) + icapa.key_len,
834 		    icapa.value_len);
835 		value[icapa.value_len] = '\0';
836 	}
837 
838 	capa = &client->capabilities[client->ncapabilities++];
839 	capa->key = key;
840 	capa->value = value;
841 
842 	if (value)
843 		log_debug("uid %d: capability %s=%s", client->euid, key, value);
844 	else
845 		log_debug("uid %d: capability %s", client->euid, key);
846 
847 	return NULL;
848 }
849 
850 static const struct got_error *
851 send_packfile(struct gotd_client *client)
852 {
853 	const struct got_error *err = NULL;
854 	struct gotd_imsg_send_packfile ipack;
855 	struct gotd_imsg_packfile_pipe ipipe;
856 	int pipe[2];
857 
858 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe) == -1)
859 		return got_error_from_errno("socketpair");
860 
861 	memset(&ipack, 0, sizeof(ipack));
862 	memset(&ipipe, 0, sizeof(ipipe));
863 
864 	ipack.client_id = client->id;
865 	if (client_has_capability(client, GOT_CAPA_SIDE_BAND_64K))
866 		ipack.report_progress = 1;
867 
868 	client->delta_cache_fd = got_opentempfd();
869 	if (client->delta_cache_fd == -1)
870 		return got_error_from_errno("got_opentempfd");
871 
872 	if (gotd_imsg_compose_event(&client->repo_read->iev,
873 	    GOTD_IMSG_SEND_PACKFILE, PROC_GOTD, client->delta_cache_fd,
874 	    &ipack, sizeof(ipack)) == -1) {
875 		err = got_error_from_errno("imsg compose SEND_PACKFILE");
876 		close(pipe[0]);
877 		close(pipe[1]);
878 		return err;
879 	}
880 
881 	ipipe.client_id = client->id;
882 
883 	/* Send pack pipe end 0 to repo_read. */
884 	if (gotd_imsg_compose_event(&client->repo_read->iev,
885 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[0],
886 	        &ipipe, sizeof(ipipe)) == -1) {
887 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
888 		close(pipe[1]);
889 		return err;
890 	}
891 
892 	/* Send pack pipe end 1 to gotsh(1) (expects just an fd, no data). */
893 	if (gotd_imsg_compose_event(&client->iev,
894 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[1], NULL, 0) == -1)
895 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
896 
897 	return err;
898 }
899 
900 static const struct got_error *
901 recv_packfile(struct gotd_client *client)
902 {
903 	const struct got_error *err = NULL;
904 	struct gotd_imsg_recv_packfile ipack;
905 	struct gotd_imsg_packfile_pipe ipipe;
906 	struct gotd_imsg_packidx_file ifile;
907 	char *basepath = NULL, *pack_path = NULL, *idx_path = NULL;
908 	int packfd = -1, idxfd = -1;
909 	int pipe[2] = { -1, -1 };
910 
911 	if (client->packfile_path) {
912 		return got_error_fmt(GOT_ERR_PRIVSEP_MSG,
913 		    "uid %d already has a pack file", client->euid);
914 	}
915 
916 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe) == -1)
917 		return got_error_from_errno("socketpair");
918 
919 	memset(&ipipe, 0, sizeof(ipipe));
920 	ipipe.client_id = client->id;
921 
922 	if (gotd_imsg_compose_event(&client->repo_write->iev,
923 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[0],
924 	        &ipipe, sizeof(ipipe)) == -1) {
925 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
926 		pipe[0] = -1;
927 		goto done;
928 	}
929 	pipe[0] = -1;
930 
931 	if (gotd_imsg_compose_event(&client->repo_write->iev,
932 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[1],
933 	        &ipipe, sizeof(ipipe)) == -1)
934 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
935 	pipe[1] = -1;
936 
937 	if (asprintf(&basepath, "%s/%s/receiving-from-uid-%d.pack",
938 	    client->repo_write->chroot_path, GOT_OBJECTS_PACK_DIR,
939 	    client->euid) == -1) {
940 		err = got_error_from_errno("asprintf");
941 		goto done;
942 	}
943 
944 	err = got_opentemp_named_fd(&pack_path, &packfd, basepath, "");
945 	if (err)
946 		goto done;
947 
948 	free(basepath);
949 	if (asprintf(&basepath, "%s/%s/receiving-from-uid-%d.idx",
950 	    client->repo_write->chroot_path, GOT_OBJECTS_PACK_DIR,
951 	    client->euid) == -1) {
952 		err = got_error_from_errno("asprintf");
953 		basepath = NULL;
954 		goto done;
955 	}
956 	err = got_opentemp_named_fd(&idx_path, &idxfd, basepath, "");
957 	if (err)
958 		goto done;
959 
960 	memset(&ifile, 0, sizeof(ifile));
961 	ifile.client_id = client->id;
962 	if (gotd_imsg_compose_event(&client->repo_write->iev,
963 	    GOTD_IMSG_PACKIDX_FILE, PROC_GOTD, idxfd,
964 	    &ifile, sizeof(ifile)) == -1) {
965 		err = got_error_from_errno("imsg compose PACKIDX_FILE");
966 		idxfd = -1;
967 		goto done;
968 	}
969 	idxfd = -1;
970 
971 	memset(&ipack, 0, sizeof(ipack));
972 	ipack.client_id = client->id;
973 	if (client_has_capability(client, GOT_CAPA_REPORT_STATUS))
974 		ipack.report_status = 1;
975 
976 	if (gotd_imsg_compose_event(&client->repo_write->iev,
977 	    GOTD_IMSG_RECV_PACKFILE, PROC_GOTD, packfd,
978 	    &ipack, sizeof(ipack)) == -1) {
979 		err = got_error_from_errno("imsg compose RECV_PACKFILE");
980 		packfd = -1;
981 		goto done;
982 	}
983 	packfd = -1;
984 
985 done:
986 	free(basepath);
987 	if (pipe[0] != -1 && close(pipe[0]) == -1 && err == NULL)
988 		err = got_error_from_errno("close");
989 	if (pipe[1] != -1 && close(pipe[1]) == -1 && err == NULL)
990 		err = got_error_from_errno("close");
991 	if (packfd != -1 && close(packfd) == -1 && err == NULL)
992 		err = got_error_from_errno("close");
993 	if (idxfd != -1 && close(idxfd) == -1 && err == NULL)
994 		err = got_error_from_errno("close");
995 	if (err) {
996 		free(pack_path);
997 		free(idx_path);
998 	} else {
999 		client->packfile_path = pack_path;
1000 		client->packidx_path = idx_path;
1001 	}
1002 	return err;
1003 }
1004 
1005 static void
1006 gotd_request(int fd, short events, void *arg)
1007 {
1008 	struct gotd_imsgev *iev = arg;
1009 	struct imsgbuf *ibuf = &iev->ibuf;
1010 	struct gotd_client *client = iev->handler_arg;
1011 	const struct got_error *err = NULL;
1012 	struct imsg imsg;
1013 	ssize_t n;
1014 
1015 	if (events & EV_WRITE) {
1016 		while (ibuf->w.queued) {
1017 			n = msgbuf_write(&ibuf->w);
1018 			if (n == -1 && errno == EPIPE) {
1019 				/*
1020 				 * The client has closed its socket.
1021 				 * This can happen when Git clients are
1022 				 * done sending pack file data.
1023 				*/
1024 				msgbuf_clear(&ibuf->w);
1025 				continue;
1026 			} else if (n == -1 && errno != EAGAIN) {
1027 				err = got_error_from_errno("imsg_flush");
1028 				disconnect_on_error(client, err);
1029 				return;
1030 			}
1031 			if (n == 0) {
1032 				/* Connection closed. */
1033 				err = got_error(GOT_ERR_EOF);
1034 				disconnect_on_error(client, err);
1035 				return;
1036 			}
1037 		}
1038 
1039 		/* Disconnect gotctl(8) now that messages have been sent. */
1040 		if (!client_is_reading(client) && !client_is_writing(client)) {
1041 			disconnect(client);
1042 			return;
1043 		}
1044 	}
1045 
1046 	if ((events & EV_READ) == 0)
1047 		return;
1048 
1049 	memset(&imsg, 0, sizeof(imsg));
1050 
1051 	while (err == NULL) {
1052 		err = gotd_imsg_recv(&imsg, ibuf, 0);
1053 		if (err) {
1054 			if (err->code == GOT_ERR_PRIVSEP_READ)
1055 				err = NULL;
1056 			break;
1057 		}
1058 
1059 		evtimer_del(&client->tmo);
1060 
1061 		switch (imsg.hdr.type) {
1062 		case GOTD_IMSG_INFO:
1063 			err = send_info(client);
1064 			break;
1065 		case GOTD_IMSG_STOP:
1066 			err = stop_gotd(client);
1067 			break;
1068 		case GOTD_IMSG_LIST_REFS:
1069 			if (client->state != GOTD_STATE_EXPECT_LIST_REFS) {
1070 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1071 				    "unexpected list-refs request received");
1072 				break;
1073 			}
1074 			err = forward_list_refs_request(client, &imsg);
1075 			if (err)
1076 				break;
1077 			client->state = GOTD_STATE_EXPECT_CAPABILITIES;
1078 			log_debug("uid %d: expecting capabilities",
1079 			    client->euid);
1080 			break;
1081 		case GOTD_IMSG_CAPABILITIES:
1082 			if (client->state != GOTD_STATE_EXPECT_CAPABILITIES) {
1083 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1084 				    "unexpected capabilities received");
1085 				break;
1086 			}
1087 			log_debug("receiving capabilities from uid %d",
1088 			    client->euid);
1089 			err = recv_capabilities(client, &imsg);
1090 			break;
1091 		case GOTD_IMSG_CAPABILITY:
1092 			if (client->state != GOTD_STATE_EXPECT_CAPABILITIES) {
1093 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1094 				    "unexpected capability received");
1095 				break;
1096 			}
1097 			err = recv_capability(client, &imsg);
1098 			if (err || client->ncapabilities < client->ncapa_alloc)
1099 				break;
1100 			if (client_is_reading(client)) {
1101 				client->state = GOTD_STATE_EXPECT_WANT;
1102 				log_debug("uid %d: expecting want-lines",
1103 				    client->euid);
1104 			} else if (client_is_writing(client)) {
1105 				client->state = GOTD_STATE_EXPECT_REF_UPDATE;
1106 				log_debug("uid %d: expecting ref-update-lines",
1107 				    client->euid);
1108 			} else
1109 				fatalx("client %d is both reading and writing",
1110 				    client->euid);
1111 			break;
1112 		case GOTD_IMSG_WANT:
1113 			if (client->state != GOTD_STATE_EXPECT_WANT) {
1114 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1115 				    "unexpected want-line received");
1116 				break;
1117 			}
1118 			log_debug("received want-line from uid %d",
1119 			    client->euid);
1120 			err = ensure_client_is_reading(client);
1121 			if (err)
1122 				break;
1123 			err = forward_want(client, &imsg);
1124 			break;
1125 		case GOTD_IMSG_REF_UPDATE:
1126 			if (client->state != GOTD_STATE_EXPECT_REF_UPDATE) {
1127 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1128 				    "unexpected ref-update-line received");
1129 				break;
1130 			}
1131 			log_debug("received ref-update-line from uid %d",
1132 			    client->euid);
1133 			err = ensure_client_is_writing(client);
1134 			if (err)
1135 				break;
1136 			err = forward_ref_update(client, &imsg);
1137 			if (err)
1138 				break;
1139 			client->state = GOTD_STATE_EXPECT_MORE_REF_UPDATES;
1140 			break;
1141 		case GOTD_IMSG_HAVE:
1142 			if (client->state != GOTD_STATE_EXPECT_HAVE) {
1143 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1144 				    "unexpected have-line received");
1145 				break;
1146 			}
1147 			log_debug("received have-line from uid %d",
1148 			    client->euid);
1149 			err = ensure_client_is_reading(client);
1150 			if (err)
1151 				break;
1152 			err = forward_have(client, &imsg);
1153 			if (err)
1154 				break;
1155 			break;
1156 		case GOTD_IMSG_FLUSH:
1157 			if (client->state == GOTD_STATE_EXPECT_WANT ||
1158 			    client->state == GOTD_STATE_EXPECT_HAVE) {
1159 				err = ensure_client_is_reading(client);
1160 				if (err)
1161 					break;
1162 			} else if (client->state ==
1163 			    GOTD_STATE_EXPECT_MORE_REF_UPDATES) {
1164 				err = ensure_client_is_writing(client);
1165 				if (err)
1166 					break;
1167 			} else {
1168 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1169 				    "unexpected flush-pkt received");
1170 				break;
1171 			}
1172 			log_debug("received flush-pkt from uid %d",
1173 			    client->euid);
1174 			if (client->state == GOTD_STATE_EXPECT_WANT) {
1175 				client->state = GOTD_STATE_EXPECT_HAVE;
1176 				log_debug("uid %d: expecting have-lines",
1177 				    client->euid);
1178 			} else if (client->state == GOTD_STATE_EXPECT_HAVE) {
1179 				client->state = GOTD_STATE_EXPECT_DONE;
1180 				log_debug("uid %d: expecting 'done'",
1181 				    client->euid);
1182 			} else if (client->state ==
1183 			    GOTD_STATE_EXPECT_MORE_REF_UPDATES) {
1184 				client->state = GOTD_STATE_EXPECT_PACKFILE;
1185 				log_debug("uid %d: expecting packfile",
1186 				    client->euid);
1187 				err = recv_packfile(client);
1188 			} else {
1189 				/* should not happen, see above */
1190 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1191 				    "unexpected client state");
1192 				break;
1193 			}
1194 			break;
1195 		case GOTD_IMSG_DONE:
1196 			if (client->state != GOTD_STATE_EXPECT_HAVE &&
1197 			    client->state != GOTD_STATE_EXPECT_DONE) {
1198 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1199 				    "unexpected flush-pkt received");
1200 				break;
1201 			}
1202 			log_debug("received 'done' from uid %d", client->euid);
1203 			err = ensure_client_is_reading(client);
1204 			if (err)
1205 				break;
1206 			client->state = GOTD_STATE_DONE;
1207 			err = send_packfile(client);
1208 			break;
1209 		default:
1210 			err = got_error(GOT_ERR_PRIVSEP_MSG);
1211 			break;
1212 		}
1213 
1214 		imsg_free(&imsg);
1215 	}
1216 
1217 	if (err) {
1218 		if (err->code != GOT_ERR_EOF ||
1219 		    client->state != GOTD_STATE_EXPECT_PACKFILE)
1220 			disconnect_on_error(client, err);
1221 	} else {
1222 		gotd_imsg_event_add(&client->iev);
1223 		evtimer_add(&client->tmo, &timeout);
1224 	}
1225 }
1226 
1227 static void
1228 gotd_request_timeout(int fd, short events, void *arg)
1229 {
1230 	struct gotd_client *client = arg;
1231 
1232 	log_debug("disconnecting uid %d due to timeout", client->euid);
1233 	disconnect(client);
1234 }
1235 
1236 static void
1237 gotd_accept(int fd, short event, void *arg)
1238 {
1239 	struct sockaddr_storage ss;
1240 	struct timeval backoff;
1241 	socklen_t len;
1242 	int s = -1;
1243 	struct gotd_client *client = NULL;
1244 	uid_t euid;
1245 	gid_t egid;
1246 
1247 	backoff.tv_sec = 1;
1248 	backoff.tv_usec = 0;
1249 
1250 	if (event_add(&gotd.ev, NULL) == -1) {
1251 		log_warn("event_add");
1252 		return;
1253 	}
1254 	if (event & EV_TIMEOUT)
1255 		return;
1256 
1257 	len = sizeof(ss);
1258 
1259 	s = accept_reserve(fd, (struct sockaddr *)&ss, &len, GOTD_FD_RESERVE,
1260 	    &inflight);
1261 
1262 	if (s == -1) {
1263 		switch (errno) {
1264 		case EINTR:
1265 		case EWOULDBLOCK:
1266 		case ECONNABORTED:
1267 			return;
1268 		case EMFILE:
1269 		case ENFILE:
1270 			event_del(&gotd.ev);
1271 			evtimer_add(&gotd.pause, &backoff);
1272 			return;
1273 		default:
1274 			log_warn("%s: accept", __func__);
1275 			return;
1276 		}
1277 	}
1278 
1279 	if (client_cnt >= GOTD_MAXCLIENTS)
1280 		goto err;
1281 
1282 	if (getpeereid(s, &euid, &egid) == -1) {
1283 		log_warn("%s: getpeereid", __func__);
1284 		goto err;
1285 	}
1286 
1287 	client = calloc(1, sizeof(*client));
1288 	if (client == NULL) {
1289 		log_warn("%s: calloc", __func__);
1290 		goto err;
1291 	}
1292 
1293 	client->state = GOTD_STATE_EXPECT_LIST_REFS;
1294 	client->id = get_client_id();
1295 	client->fd = s;
1296 	s = -1;
1297 	client->delta_cache_fd = -1;
1298 	client->euid = euid;
1299 	client->egid = egid;
1300 	client->nref_updates = -1;
1301 
1302 	imsg_init(&client->iev.ibuf, client->fd);
1303 	client->iev.handler = gotd_request;
1304 	client->iev.events = EV_READ;
1305 	client->iev.handler_arg = client;
1306 
1307 	event_set(&client->iev.ev, client->fd, EV_READ, gotd_request,
1308 	    &client->iev);
1309 	gotd_imsg_event_add(&client->iev);
1310 
1311 	evtimer_set(&client->tmo, gotd_request_timeout, client);
1312 
1313 	add_client(client);
1314 	log_debug("%s: new client uid %d connected on fd %d", __func__,
1315 	    client->euid, client->fd);
1316 	return;
1317 err:
1318 	inflight--;
1319 	if (s != -1)
1320 		close(s);
1321 	free(client);
1322 }
1323 
1324 static void
1325 gotd_accept_paused(int fd, short event, void *arg)
1326 {
1327 	event_add(&gotd.ev, NULL);
1328 }
1329 
1330 static const char *gotd_proc_names[PROC_MAX] = {
1331 	"parent",
1332 	"repo_read",
1333 	"repo_write"
1334 };
1335 
1336 static struct gotd_child_proc *
1337 get_proc_for_pid(pid_t pid)
1338 {
1339 	struct gotd_child_proc *proc;
1340 	int i;
1341 
1342 	for (i = 0; i < gotd.nprocs; i++) {
1343 		proc = &gotd.procs[i];
1344 		if (proc->pid == pid)
1345 			return proc;
1346 	}
1347 
1348 	return NULL;
1349 }
1350 
1351 static void
1352 kill_proc(struct gotd_child_proc *proc, int fatal)
1353 {
1354 	if (fatal) {
1355 		log_warnx("sending SIGKILL to PID %d", proc->pid);
1356 		kill(proc->pid, SIGKILL);
1357 	} else
1358 		kill(proc->pid, SIGTERM);
1359 }
1360 
1361 static void
1362 gotd_shutdown(void)
1363 {
1364 	pid_t	 pid;
1365 	int	 status, i;
1366 	struct gotd_child_proc *proc;
1367 
1368 	for (i = 0; i < gotd.nprocs; i++) {
1369 		proc = &gotd.procs[i];
1370 		msgbuf_clear(&proc->iev.ibuf.w);
1371 		close(proc->iev.ibuf.fd);
1372 		kill_proc(proc, 0);
1373 	}
1374 
1375 	log_debug("waiting for children to terminate");
1376 	do {
1377 		pid = wait(&status);
1378 		if (pid == -1) {
1379 			if (errno != EINTR && errno != ECHILD)
1380 				fatal("wait");
1381 		} else if (WIFSIGNALED(status)) {
1382 			proc = get_proc_for_pid(pid);
1383 			log_warnx("%s %s child process terminated; signal %d",
1384 			    proc ? gotd_proc_names[proc->type] : "",
1385 			    proc ? proc->chroot_path : "", WTERMSIG(status));
1386 		}	
1387 	} while (pid != -1 || (pid == -1 && errno == EINTR));
1388 
1389 	log_info("terminating");
1390 	exit(0);
1391 }
1392 
1393 void
1394 gotd_sighdlr(int sig, short event, void *arg)
1395 {
1396 	/*
1397 	 * Normal signal handler rules don't apply because libevent
1398 	 * decouples for us.
1399 	 */
1400 
1401 	switch (sig) {
1402 	case SIGHUP:
1403 		log_info("%s: ignoring SIGHUP", __func__);
1404 		break;
1405 	case SIGUSR1:
1406 		log_info("%s: ignoring SIGUSR1", __func__);
1407 		break;
1408 	case SIGTERM:
1409 	case SIGINT:
1410 		gotd_shutdown();
1411 		log_warnx("gotd terminating");
1412 		exit(0);
1413 		break;
1414 	default:
1415 		fatalx("unexpected signal");
1416 	}
1417 }
1418 
1419 static const struct got_error *
1420 ensure_proc_is_reading(struct gotd_client *client,
1421     struct gotd_child_proc *proc)
1422 {
1423 	if (!client_is_reading(client)) {
1424 		kill_proc(proc, 1);
1425 		return got_error_fmt(GOT_ERR_BAD_PACKET,
1426 		    "PID %d handled a read-request for uid %d but this "
1427 		    "user is not reading from a repository", proc->pid,
1428 		    client->euid);
1429 	}
1430 
1431 	return NULL;
1432 }
1433 
1434 static const struct got_error *
1435 ensure_proc_is_writing(struct gotd_client *client,
1436     struct gotd_child_proc *proc)
1437 {
1438 	if (!client_is_writing(client)) {
1439 		kill_proc(proc, 1);
1440 		return got_error_fmt(GOT_ERR_BAD_PACKET,
1441 		    "PID %d handled a write-request for uid %d but this "
1442 		    "user is not writing to a repository", proc->pid,
1443 		    client->euid);
1444 	}
1445 
1446 	return NULL;
1447 }
1448 
1449 static int
1450 verify_imsg_src(struct gotd_client *client, struct gotd_child_proc *proc,
1451     struct imsg *imsg)
1452 {
1453 	const struct got_error *err;
1454 	struct gotd_child_proc *client_proc;
1455 	int ret = 0;
1456 
1457 	client_proc = get_client_proc(client);
1458 	if (client_proc == NULL)
1459 		fatalx("no process found for uid %d", client->euid);
1460 
1461 	if (proc->pid != client_proc->pid) {
1462 		kill_proc(proc, 1);
1463 		log_warnx("received message from PID %d for uid %d, while "
1464 		    "PID %d is the process serving this user",
1465 		    proc->pid, client->euid, client_proc->pid);
1466 		return 0;
1467 	}
1468 
1469 	switch (imsg->hdr.type) {
1470 	case GOTD_IMSG_ERROR:
1471 		ret = 1;
1472 		break;
1473 	case GOTD_IMSG_PACKFILE_DONE:
1474 		err = ensure_proc_is_reading(client, proc);
1475 		if (err)
1476 			log_warnx("uid %d: %s", client->euid, err->msg);
1477 		else
1478 			ret = 1;
1479 		break;
1480 	case GOTD_IMSG_PACKFILE_INSTALL:
1481 	case GOTD_IMSG_REF_UPDATES_START:
1482 	case GOTD_IMSG_REF_UPDATE:
1483 		err = ensure_proc_is_writing(client, proc);
1484 		if (err)
1485 			log_warnx("uid %d: %s", client->euid, err->msg);
1486 		else
1487 			ret = 1;
1488 		break;
1489 	default:
1490 		log_debug("%s: unexpected imsg %d", __func__, imsg->hdr.type);
1491 		break;
1492 	}
1493 
1494 	return ret;
1495 }
1496 
1497 static const struct got_error *
1498 recv_packfile_done(uint32_t *client_id, struct imsg *imsg)
1499 {
1500 	struct gotd_imsg_packfile_done idone;
1501 	size_t datalen;
1502 
1503 	log_debug("packfile-done received");
1504 
1505 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1506 	if (datalen != sizeof(idone))
1507 		return got_error(GOT_ERR_PRIVSEP_LEN);
1508 	memcpy(&idone, imsg->data, sizeof(idone));
1509 
1510 	*client_id = idone.client_id;
1511 	return NULL;
1512 }
1513 
1514 static const struct got_error *
1515 recv_packfile_install(uint32_t *client_id, struct imsg *imsg)
1516 {
1517 	struct gotd_imsg_packfile_install inst;
1518 	size_t datalen;
1519 
1520 	log_debug("packfile-install received");
1521 
1522 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1523 	if (datalen != sizeof(inst))
1524 		return got_error(GOT_ERR_PRIVSEP_LEN);
1525 	memcpy(&inst, imsg->data, sizeof(inst));
1526 
1527 	*client_id = inst.client_id;
1528 	return NULL;
1529 }
1530 
1531 static const struct got_error *
1532 recv_ref_updates_start(uint32_t *client_id, struct imsg *imsg)
1533 {
1534 	struct gotd_imsg_ref_updates_start istart;
1535 	size_t datalen;
1536 
1537 	log_debug("ref-updates-start received");
1538 
1539 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1540 	if (datalen != sizeof(istart))
1541 		return got_error(GOT_ERR_PRIVSEP_LEN);
1542 	memcpy(&istart, imsg->data, sizeof(istart));
1543 
1544 	*client_id = istart.client_id;
1545 	return NULL;
1546 }
1547 
1548 static const struct got_error *
1549 recv_ref_update(uint32_t *client_id, struct imsg *imsg)
1550 {
1551 	struct gotd_imsg_ref_update iref;
1552 	size_t datalen;
1553 
1554 	log_debug("ref-update received");
1555 
1556 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1557 	if (datalen < sizeof(iref))
1558 		return got_error(GOT_ERR_PRIVSEP_LEN);
1559 	memcpy(&iref, imsg->data, sizeof(iref));
1560 
1561 	*client_id = iref.client_id;
1562 	return NULL;
1563 }
1564 
1565 static const struct got_error *
1566 send_ref_update_ok(struct gotd_client *client,
1567     struct gotd_imsg_ref_update *iref, const char *refname)
1568 {
1569 	struct gotd_imsg_ref_update_ok iok;
1570 	struct ibuf *wbuf;
1571 	size_t len;
1572 
1573 	memset(&iok, 0, sizeof(iok));
1574 	iok.client_id = client->id;
1575 	memcpy(iok.old_id, iref->old_id, SHA1_DIGEST_LENGTH);
1576 	memcpy(iok.new_id, iref->new_id, SHA1_DIGEST_LENGTH);
1577 	iok.name_len = strlen(refname);
1578 
1579 	len = sizeof(iok) + iok.name_len;
1580 	wbuf = imsg_create(&client->iev.ibuf, GOTD_IMSG_REF_UPDATE_OK,
1581 	    PROC_GOTD, gotd.pid, len);
1582 	if (wbuf == NULL)
1583 		return got_error_from_errno("imsg_create REF_UPDATE_OK");
1584 
1585 	if (imsg_add(wbuf, &iok, sizeof(iok)) == -1)
1586 		return got_error_from_errno("imsg_add REF_UPDATE_OK");
1587 	if (imsg_add(wbuf, refname, iok.name_len) == -1)
1588 		return got_error_from_errno("imsg_add REF_UPDATE_OK");
1589 
1590 	wbuf->fd = -1;
1591 	imsg_close(&client->iev.ibuf, wbuf);
1592 	gotd_imsg_event_add(&client->iev);
1593 	return NULL;
1594 }
1595 
1596 static void
1597 send_refs_updated(struct gotd_client *client)
1598 {
1599 	if (gotd_imsg_compose_event(&client->iev,
1600 	    GOTD_IMSG_REFS_UPDATED, PROC_GOTD, -1, NULL, 0) == -1)
1601 		log_warn("imsg compose REFS_UPDATED");
1602 }
1603 
1604 static const struct got_error *
1605 send_ref_update_ng(struct gotd_client *client,
1606     struct gotd_imsg_ref_update *iref, const char *refname,
1607     const char *reason)
1608 {
1609 	const struct got_error *ng_err;
1610 	struct gotd_imsg_ref_update_ng ing;
1611 	struct ibuf *wbuf;
1612 	size_t len;
1613 
1614 	memset(&ing, 0, sizeof(ing));
1615 	ing.client_id = client->id;
1616 	memcpy(ing.old_id, iref->old_id, SHA1_DIGEST_LENGTH);
1617 	memcpy(ing.new_id, iref->new_id, SHA1_DIGEST_LENGTH);
1618 	ing.name_len = strlen(refname);
1619 
1620 	ng_err = got_error_fmt(GOT_ERR_REF_BUSY, "%s", reason);
1621 	ing.reason_len = strlen(ng_err->msg);
1622 
1623 	len = sizeof(ing) + ing.name_len + ing.reason_len;
1624 	wbuf = imsg_create(&client->iev.ibuf, GOTD_IMSG_REF_UPDATE_NG,
1625 	    PROC_GOTD, gotd.pid, len);
1626 	if (wbuf == NULL)
1627 		return got_error_from_errno("imsg_create REF_UPDATE_NG");
1628 
1629 	if (imsg_add(wbuf, &ing, sizeof(ing)) == -1)
1630 		return got_error_from_errno("imsg_add REF_UPDATE_NG");
1631 	if (imsg_add(wbuf, refname, ing.name_len) == -1)
1632 		return got_error_from_errno("imsg_add REF_UPDATE_NG");
1633 	if (imsg_add(wbuf, ng_err->msg, ing.reason_len) == -1)
1634 		return got_error_from_errno("imsg_add REF_UPDATE_NG");
1635 
1636 	wbuf->fd = -1;
1637 	imsg_close(&client->iev.ibuf, wbuf);
1638 	gotd_imsg_event_add(&client->iev);
1639 	return NULL;
1640 }
1641 
1642 static const struct got_error *
1643 install_pack(struct gotd_client *client, const char *repo_path,
1644     struct imsg *imsg)
1645 {
1646 	const struct got_error *err = NULL;
1647 	struct gotd_imsg_packfile_install inst;
1648 	char hex[SHA1_DIGEST_STRING_LENGTH];
1649 	size_t datalen;
1650 	char *packfile_path = NULL, *packidx_path = NULL;
1651 
1652 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1653 	if (datalen != sizeof(inst))
1654 		return got_error(GOT_ERR_PRIVSEP_LEN);
1655 	memcpy(&inst, imsg->data, sizeof(inst));
1656 
1657 	if (client->packfile_path == NULL)
1658 		return got_error_msg(GOT_ERR_BAD_REQUEST,
1659 		    "client has no pack file");
1660 	if (client->packidx_path == NULL)
1661 		return got_error_msg(GOT_ERR_BAD_REQUEST,
1662 		    "client has no pack file index");
1663 
1664 	if (got_sha1_digest_to_str(inst.pack_sha1, hex, sizeof(hex)) == NULL)
1665 		return got_error_msg(GOT_ERR_NO_SPACE,
1666 		    "could not convert pack file SHA1 to hex");
1667 
1668 	if (asprintf(&packfile_path, "/%s/%s/pack-%s.pack",
1669 	    repo_path, GOT_OBJECTS_PACK_DIR, hex) == -1) {
1670 		err = got_error_from_errno("asprintf");
1671 		goto done;
1672 	}
1673 
1674 	if (asprintf(&packidx_path, "/%s/%s/pack-%s.idx",
1675 	    repo_path, GOT_OBJECTS_PACK_DIR, hex) == -1) {
1676 		err = got_error_from_errno("asprintf");
1677 		goto done;
1678 	}
1679 
1680 	if (rename(client->packfile_path, packfile_path) == -1) {
1681 		err = got_error_from_errno3("rename", client->packfile_path,
1682 		    packfile_path);
1683 		goto done;
1684 	}
1685 
1686 	free(client->packfile_path);
1687 	client->packfile_path = NULL;
1688 
1689 	if (rename(client->packidx_path, packidx_path) == -1) {
1690 		err = got_error_from_errno3("rename", client->packidx_path,
1691 		    packidx_path);
1692 		goto done;
1693 	}
1694 
1695 	free(client->packidx_path);
1696 	client->packidx_path = NULL;
1697 done:
1698 	free(packfile_path);
1699 	free(packidx_path);
1700 	return err;
1701 }
1702 
1703 static const struct got_error *
1704 begin_ref_updates(struct gotd_client *client, struct imsg *imsg)
1705 {
1706 	struct gotd_imsg_ref_updates_start istart;
1707 	size_t datalen;
1708 
1709 	if (client->nref_updates != -1)
1710 		return got_error(GOT_ERR_PRIVSEP_MSG);
1711 
1712 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1713 	if (datalen != sizeof(istart))
1714 		return got_error(GOT_ERR_PRIVSEP_LEN);
1715 	memcpy(&istart, imsg->data, sizeof(istart));
1716 
1717 	if (istart.nref_updates <= 0)
1718 		return got_error(GOT_ERR_PRIVSEP_MSG);
1719 
1720 	client->nref_updates = istart.nref_updates;
1721 	return NULL;
1722 }
1723 
1724 static const struct got_error *
1725 update_ref(struct gotd_client *client, const char *repo_path,
1726     struct imsg *imsg)
1727 {
1728 	const struct got_error *err = NULL;
1729 	struct got_repository *repo = NULL;
1730 	struct got_reference *ref = NULL;
1731 	struct gotd_imsg_ref_update iref;
1732 	struct got_object_id old_id, new_id;
1733 	struct got_object_id *id = NULL;
1734 	struct got_object *obj = NULL;
1735 	char *refname = NULL;
1736 	size_t datalen;
1737 	int locked = 0;
1738 
1739 	log_debug("update-ref from uid %d", client->euid);
1740 
1741 	if (client->nref_updates <= 0)
1742 		return got_error(GOT_ERR_PRIVSEP_MSG);
1743 
1744 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1745 	if (datalen < sizeof(iref))
1746 		return got_error(GOT_ERR_PRIVSEP_LEN);
1747 	memcpy(&iref, imsg->data, sizeof(iref));
1748 	if (datalen != sizeof(iref) + iref.name_len)
1749 		return got_error(GOT_ERR_PRIVSEP_LEN);
1750 	refname = malloc(iref.name_len + 1);
1751 	if (refname == NULL)
1752 		return got_error_from_errno("malloc");
1753 	memcpy(refname, imsg->data + sizeof(iref), iref.name_len);
1754 	refname[iref.name_len] = '\0';
1755 
1756 	log_debug("updating ref %s for uid %d", refname, client->euid);
1757 
1758 	err = got_repo_open(&repo, repo_path, NULL, NULL);
1759 	if (err)
1760 		goto done;
1761 
1762 	memcpy(old_id.sha1, iref.old_id, SHA1_DIGEST_LENGTH);
1763 	memcpy(new_id.sha1, iref.new_id, SHA1_DIGEST_LENGTH);
1764 	err = got_object_open(&obj, repo, &new_id);
1765 	if (err)
1766 		goto done;
1767 
1768 	if (iref.ref_is_new) {
1769 		err = got_ref_open(&ref, repo, refname, 0);
1770 		if (err) {
1771 			if (err->code != GOT_ERR_NOT_REF)
1772 				goto done;
1773 			err = got_ref_alloc(&ref, refname, &new_id);
1774 			if (err)
1775 				goto done;
1776 			err = got_ref_write(ref, repo); /* will lock/unlock */
1777 			if (err)
1778 				goto done;
1779 		} else {
1780 			err = got_error_fmt(GOT_ERR_REF_BUSY,
1781 			    "%s has been created by someone else "
1782 			    "while transaction was in progress",
1783 			    got_ref_get_name(ref));
1784 			goto done;
1785 		}
1786 	} else {
1787 		err = got_ref_open(&ref, repo, refname, 1 /* lock */);
1788 		if (err)
1789 			goto done;
1790 		locked = 1;
1791 
1792 		err = got_ref_resolve(&id, repo, ref);
1793 		if (err)
1794 			goto done;
1795 
1796 		if (got_object_id_cmp(id, &old_id) != 0) {
1797 			err = got_error_fmt(GOT_ERR_REF_BUSY,
1798 			    "%s has been modified by someone else "
1799 			    "while transaction was in progress",
1800 			    got_ref_get_name(ref));
1801 			goto done;
1802 		}
1803 
1804 		err = got_ref_change_ref(ref, &new_id);
1805 		if (err)
1806 			goto done;
1807 
1808 		err = got_ref_write(ref, repo);
1809 		if (err)
1810 			goto done;
1811 
1812 		free(id);
1813 		id = NULL;
1814 	}
1815 done:
1816 	if (err) {
1817 		if (err->code == GOT_ERR_LOCKFILE_TIMEOUT) {
1818 			err = got_error_fmt(GOT_ERR_LOCKFILE_TIMEOUT,
1819 			    "could not acquire exclusive file lock for %s",
1820 			    refname);
1821 		}
1822 		send_ref_update_ng(client, &iref, refname, err->msg);
1823 	} else
1824 		send_ref_update_ok(client, &iref, refname);
1825 
1826 	if (client->nref_updates > 0) {
1827 		client->nref_updates--;
1828 		if (client->nref_updates == 0)
1829 			send_refs_updated(client);
1830 
1831 	}
1832 	if (locked) {
1833 		const struct got_error *unlock_err;
1834 		unlock_err = got_ref_unlock(ref);
1835 		if (unlock_err && err == NULL)
1836 			err = unlock_err;
1837 	}
1838 	if (ref)
1839 		got_ref_close(ref);
1840 	if (obj)
1841 		got_object_close(obj);
1842 	if (repo)
1843 		got_repo_close(repo);
1844 	free(refname);
1845 	free(id);
1846 	return err;
1847 }
1848 
1849 static void
1850 gotd_dispatch(int fd, short event, void *arg)
1851 {
1852 	struct gotd_imsgev *iev = arg;
1853 	struct imsgbuf *ibuf = &iev->ibuf;
1854 	struct gotd_child_proc *proc = NULL;
1855 	ssize_t n;
1856 	int shut = 0;
1857 	struct imsg imsg;
1858 
1859 	if (event & EV_READ) {
1860 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1861 			fatal("imsg_read error");
1862 		if (n == 0) {
1863 			/* Connection closed. */
1864 			shut = 1;
1865 			goto done;
1866 		}
1867 	}
1868 
1869 	if (event & EV_WRITE) {
1870 		n = msgbuf_write(&ibuf->w);
1871 		if (n == -1 && errno != EAGAIN)
1872 			fatal("msgbuf_write");
1873 		if (n == 0) {
1874 			/* Connection closed. */
1875 			shut = 1;
1876 			goto done;
1877 		}
1878 	}
1879 
1880 	proc = find_proc_by_fd(fd);
1881 	if (proc == NULL)
1882 		fatalx("cannot find child process for fd %d", fd);
1883 
1884 	for (;;) {
1885 		const struct got_error *err = NULL;
1886 		struct gotd_client *client = NULL;
1887 		uint32_t client_id = 0;
1888 		int do_disconnect = 0;
1889 		int do_ref_updates = 0, do_ref_update = 0;
1890 		int do_packfile_install = 0;
1891 
1892 		if ((n = imsg_get(ibuf, &imsg)) == -1)
1893 			fatal("%s: imsg_get error", __func__);
1894 		if (n == 0)	/* No more messages. */
1895 			break;
1896 
1897 		switch (imsg.hdr.type) {
1898 		case GOTD_IMSG_ERROR:
1899 			do_disconnect = 1;
1900 			err = gotd_imsg_recv_error(&client_id, &imsg);
1901 			break;
1902 		case GOTD_IMSG_PACKFILE_DONE:
1903 			do_disconnect = 1;
1904 			err = recv_packfile_done(&client_id, &imsg);
1905 			break;
1906 		case GOTD_IMSG_PACKFILE_INSTALL:
1907 			err = recv_packfile_install(&client_id, &imsg);
1908 			if (err == NULL)
1909 				do_packfile_install = 1;
1910 			break;
1911 		case GOTD_IMSG_REF_UPDATES_START:
1912 			err = recv_ref_updates_start(&client_id, &imsg);
1913 			if (err == NULL)
1914 				do_ref_updates = 1;
1915 			break;
1916 		case GOTD_IMSG_REF_UPDATE:
1917 			err = recv_ref_update(&client_id, &imsg);
1918 			if (err == NULL)
1919 				do_ref_update = 1;
1920 			break;
1921 		default:
1922 			log_debug("unexpected imsg %d", imsg.hdr.type);
1923 			break;
1924 		}
1925 
1926 		client = find_client(client_id);
1927 		if (client == NULL) {
1928 			log_warnx("%s: client not found", __func__);
1929 			imsg_free(&imsg);
1930 			continue;
1931 		}
1932 
1933 		if (!verify_imsg_src(client, proc, &imsg)) {
1934 			log_debug("dropping imsg type %d from PID %d",
1935 			    imsg.hdr.type, proc->pid);
1936 			imsg_free(&imsg);
1937 			continue;
1938 		}
1939 		if (err)
1940 			log_warnx("uid %d: %s", client->euid, err->msg);
1941 
1942 		if (do_disconnect) {
1943 			if (err)
1944 				disconnect_on_error(client, err);
1945 			else
1946 				disconnect(client);
1947 		} else {
1948 			if (do_packfile_install)
1949 				err = install_pack(client, proc->chroot_path,
1950 				    &imsg);
1951 			else if (do_ref_updates)
1952 				err = begin_ref_updates(client, &imsg);
1953 			else if (do_ref_update)
1954 				err = update_ref(client, proc->chroot_path,
1955 				    &imsg);
1956 			if (err)
1957 				log_warnx("uid %d: %s", client->euid, err->msg);
1958 		}
1959 		imsg_free(&imsg);
1960 	}
1961 done:
1962 	if (!shut) {
1963 		gotd_imsg_event_add(iev);
1964 	} else {
1965 		/* This pipe is dead. Remove its event handler */
1966 		event_del(&iev->ev);
1967 		event_loopexit(NULL);
1968 	}
1969 }
1970 
1971 static pid_t
1972 start_child(enum gotd_procid proc_id, const char *chroot_path,
1973     char *argv0, const char *confpath, int fd, int daemonize, int verbosity)
1974 {
1975 	char	*argv[11];
1976 	int	 argc = 0;
1977 	pid_t	 pid;
1978 
1979 	switch (pid = fork()) {
1980 	case -1:
1981 		fatal("cannot fork");
1982 	case 0:
1983 		break;
1984 	default:
1985 		close(fd);
1986 		return pid;
1987 	}
1988 
1989 	if (fd != GOTD_SOCK_FILENO) {
1990 		if (dup2(fd, GOTD_SOCK_FILENO) == -1)
1991 			fatal("cannot setup imsg fd");
1992 	} else if (fcntl(fd, F_SETFD, 0) == -1)
1993 		fatal("cannot setup imsg fd");
1994 
1995 	argv[argc++] = argv0;
1996 	switch (proc_id) {
1997 	case PROC_REPO_READ:
1998 		argv[argc++] = (char *)"-R";
1999 		break;
2000 	case PROC_REPO_WRITE:
2001 		argv[argc++] = (char *)"-W";
2002 		break;
2003 	default:
2004 		fatalx("invalid process id %d", proc_id);
2005 	}
2006 
2007 	argv[argc++] = (char *)"-f";
2008 	argv[argc++] = (char *)confpath;
2009 
2010 	argv[argc++] = (char *)"-P";
2011 	argv[argc++] = (char *)chroot_path;
2012 
2013 	if (!daemonize)
2014 		argv[argc++] = (char *)"-d";
2015 	if (verbosity > 0)
2016 		argv[argc++] = (char *)"-v";
2017 	if (verbosity > 1)
2018 		argv[argc++] = (char *)"-v";
2019 	argv[argc++] = NULL;
2020 
2021 	execvp(argv0, argv);
2022 	fatal("execvp");
2023 }
2024 
2025 static void
2026 start_repo_children(struct gotd *gotd, char *argv0, const char *confpath,
2027     int daemonize, int verbosity)
2028 {
2029 	struct gotd_repo *repo = NULL;
2030 	struct gotd_child_proc *proc;
2031 	int i;
2032 
2033 	/*
2034 	 * XXX For now, use one reader and one writer per repository.
2035 	 * This should be changed to N readers + M writers.
2036 	 */
2037 	gotd->nprocs = gotd->nrepos * 2;
2038 	gotd->procs = calloc(gotd->nprocs, sizeof(*gotd->procs));
2039 	if (gotd->procs == NULL)
2040 		fatal("calloc");
2041 	for (i = 0; i < gotd->nprocs; i++) {
2042 		if (repo == NULL)
2043 			repo = TAILQ_FIRST(&gotd->repos);
2044 		proc = &gotd->procs[i];
2045 		if (i < gotd->nrepos)
2046 			proc->type = PROC_REPO_READ;
2047 		else
2048 			proc->type = PROC_REPO_WRITE;
2049 		if (strlcpy(proc->repo_name, repo->name,
2050 		    sizeof(proc->repo_name)) >= sizeof(proc->repo_name))
2051 			fatalx("repository name too long: %s", repo->name);
2052 		log_debug("adding repository %s", repo->name);
2053 		if (realpath(repo->path, proc->chroot_path) == NULL)
2054 			fatal("%s", repo->path);
2055 		if (socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK,
2056 		    PF_UNSPEC, proc->pipe) == -1)
2057 			fatal("socketpair");
2058 		proc->pid = start_child(proc->type, proc->chroot_path, argv0,
2059 		    confpath, proc->pipe[1], daemonize, verbosity);
2060 		imsg_init(&proc->iev.ibuf, proc->pipe[0]);
2061 		log_debug("proc %s %s is on fd %d",
2062 		    gotd_proc_names[proc->type], proc->chroot_path,
2063 		    proc->pipe[0]);
2064 		proc->iev.handler = gotd_dispatch;
2065 		proc->iev.events = EV_READ;
2066 		proc->iev.handler_arg = NULL;
2067 		event_set(&proc->iev.ev, proc->iev.ibuf.fd, EV_READ,
2068 		    gotd_dispatch, &proc->iev);
2069 
2070 		repo = TAILQ_NEXT(repo, entry);
2071 	}
2072 }
2073 
2074 static void
2075 apply_unveil(void)
2076 {
2077 	struct gotd_repo *repo;
2078 
2079 	TAILQ_FOREACH(repo, &gotd.repos, entry) {
2080 		if (unveil(repo->path, "rwc") == -1)
2081 			fatal("unveil %s", repo->path);
2082 	}
2083 
2084 	if (unveil(GOT_TMPDIR_STR, "rwc") == -1)
2085 		fatal("unveil %s", GOT_TMPDIR_STR);
2086 
2087 	if (unveil(NULL, NULL) == -1)
2088 		fatal("unveil");
2089 }
2090 
2091 int
2092 main(int argc, char **argv)
2093 {
2094 	const struct got_error *error = NULL;
2095 	int ch, fd = -1, daemonize = 1, verbosity = 0, noaction = 0;
2096 	const char *confpath = GOTD_CONF_PATH;
2097 	char *argv0 = argv[0];
2098 	char title[2048];
2099 	int ngroups = NGROUPS_MAX;
2100 	struct passwd *pw = NULL;
2101 	struct group *gr = NULL;
2102 	char *repo_path = NULL;
2103 	enum gotd_procid proc_id = PROC_GOTD;
2104 	struct event evsigint, evsigterm, evsighup, evsigusr1;
2105 	int *pack_fds = NULL, *temp_fds = NULL;
2106 
2107 	log_init(1, LOG_DAEMON); /* Log to stderr until daemonized. */
2108 
2109 	while ((ch = getopt(argc, argv, "df:nP:RvW")) != -1) {
2110 		switch (ch) {
2111 		case 'd':
2112 			daemonize = 0;
2113 			break;
2114 		case 'f':
2115 			confpath = optarg;
2116 			break;
2117 		case 'n':
2118 			noaction = 1;
2119 			break;
2120 		case 'P':
2121 			repo_path = realpath(optarg, NULL);
2122 			if (repo_path == NULL)
2123 				fatal("realpath '%s'", optarg);
2124 			break;
2125 		case 'R':
2126 			proc_id = PROC_REPO_READ;
2127 			break;
2128 		case 'v':
2129 			if (verbosity < 3)
2130 				verbosity++;
2131 			break;
2132 		case 'W':
2133 			proc_id = PROC_REPO_WRITE;
2134 			break;
2135 		default:
2136 			usage();
2137 		}
2138 	}
2139 
2140 	argc -= optind;
2141 	argv += optind;
2142 
2143 	if (argc != 0)
2144 		usage();
2145 
2146 	if (geteuid())
2147 		fatalx("need root privileges");
2148 
2149 	log_init(daemonize ? 0 : 1, LOG_DAEMON);
2150 	log_setverbose(verbosity);
2151 
2152 	if (parse_config(confpath, proc_id, &gotd) != 0)
2153 		return 1;
2154 
2155 	if (proc_id == PROC_GOTD &&
2156 	    (gotd.nrepos == 0 || TAILQ_EMPTY(&gotd.repos)))
2157 		fatalx("no repository defined in configuration file");
2158 
2159 	pw = getpwnam(gotd.user_name);
2160 	if (pw == NULL)
2161 		fatal("getpwuid: user %s not found", gotd.user_name);
2162 
2163 	if (pw->pw_uid == 0) {
2164 		fatalx("cannot run %s as %s: the user running %s "
2165 		    "must not be the superuser",
2166 		    getprogname(), pw->pw_name, getprogname());
2167 	}
2168 
2169 	if (getgrouplist(pw->pw_name, pw->pw_gid, gotd.groups, &ngroups) == -1)
2170 		log_warnx("group membership list truncated");
2171 	gotd.ngroups = ngroups;
2172 
2173 	gr = match_group(gotd.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_GOTD &&
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 && verbosity) {
2196 		log_info("socket: %s", gotd.unix_socket_path);
2197 		log_info("user: %s", pw->pw_name);
2198 		log_info("secondary group: %s", gr->gr_name);
2199 
2200 		fd = unix_socket_listen(gotd.unix_socket_path, pw->pw_uid,
2201 		    gr->gr_gid);
2202 		if (fd == -1) {
2203 			fatal("cannot listen on unix socket %s",
2204 			    gotd.unix_socket_path);
2205 		}
2206 	}
2207 
2208 	if (proc_id == PROC_GOTD) {
2209 		gotd.pid = getpid();
2210 		snprintf(title, sizeof(title), "%s", gotd_proc_names[proc_id]);
2211 		start_repo_children(&gotd, argv0, confpath, daemonize,
2212 		    verbosity);
2213 		arc4random_buf(&clients_hash_key, sizeof(clients_hash_key));
2214 		if (daemonize && daemon(0, 0) == -1)
2215 			fatal("daemon");
2216 	} else if (proc_id == PROC_REPO_READ || proc_id == PROC_REPO_WRITE) {
2217 		error = got_repo_pack_fds_open(&pack_fds);
2218 		if (error != NULL)
2219 			fatalx("cannot open pack tempfiles: %s", error->msg);
2220 		error = got_repo_temp_fds_open(&temp_fds);
2221 		if (error != NULL)
2222 			fatalx("cannot open pack tempfiles: %s", error->msg);
2223 		if (repo_path == NULL)
2224 			fatalx("repository path not specified");
2225 		snprintf(title, sizeof(title), "%s %s",
2226 		    gotd_proc_names[proc_id], repo_path);
2227 		if (chroot(repo_path) == -1)
2228 			fatal("chroot");
2229 		if (chdir("/") == -1)
2230 			fatal("chdir(\"/\")");
2231 		if (daemonize && daemon(1, 0) == -1)
2232 			fatal("daemon");
2233 	} else
2234 		fatal("invalid process id %d", proc_id);
2235 
2236 	setproctitle("%s", title);
2237 	log_procinit(title);
2238 
2239 	/* Drop root privileges. */
2240 	if (setgid(pw->pw_gid) == -1)
2241 		fatal("setgid %d failed", pw->pw_gid);
2242 	if (setuid(pw->pw_uid) == -1)
2243 		fatal("setuid %d failed", pw->pw_uid);
2244 
2245 	event_init();
2246 
2247 	switch (proc_id) {
2248 	case PROC_GOTD:
2249 #ifndef PROFILE
2250 		if (pledge("stdio rpath wpath cpath proc getpw sendfd recvfd "
2251 		    "fattr flock unix unveil", NULL) == -1)
2252 			err(1, "pledge");
2253 #endif
2254 		break;
2255 	case PROC_REPO_READ:
2256 #ifndef PROFILE
2257 		if (pledge("stdio rpath recvfd", NULL) == -1)
2258 			err(1, "pledge");
2259 #endif
2260 		repo_read_main(title, pack_fds, temp_fds);
2261 		/* NOTREACHED */
2262 		exit(0);
2263 	case PROC_REPO_WRITE:
2264 #ifndef PROFILE
2265 		if (pledge("stdio rpath sendfd recvfd", NULL) == -1)
2266 			err(1, "pledge");
2267 #endif
2268 		repo_write_main(title, pack_fds, temp_fds);
2269 		/* NOTREACHED */
2270 		exit(0);
2271 	default:
2272 		fatal("invalid process id %d", proc_id);
2273 	}
2274 
2275 	if (proc_id != PROC_GOTD)
2276 		fatal("invalid process id %d", proc_id);
2277 
2278 	apply_unveil();
2279 
2280 	signal_set(&evsigint, SIGINT, gotd_sighdlr, NULL);
2281 	signal_set(&evsigterm, SIGTERM, gotd_sighdlr, NULL);
2282 	signal_set(&evsighup, SIGHUP, gotd_sighdlr, NULL);
2283 	signal_set(&evsigusr1, SIGUSR1, gotd_sighdlr, NULL);
2284 	signal(SIGPIPE, SIG_IGN);
2285 
2286 	signal_add(&evsigint, NULL);
2287 	signal_add(&evsigterm, NULL);
2288 	signal_add(&evsighup, NULL);
2289 	signal_add(&evsigusr1, NULL);
2290 
2291 	event_set(&gotd.ev, fd, EV_READ | EV_PERSIST, gotd_accept, NULL);
2292 	if (event_add(&gotd.ev, NULL))
2293 		fatalx("event add");
2294 	evtimer_set(&gotd.pause, gotd_accept_paused, NULL);
2295 
2296 	event_dispatch();
2297 
2298 	if (fd != -1)
2299 		close(fd);
2300 	if (pack_fds)
2301 		got_repo_pack_fds_close(pack_fds);
2302 	free(repo_path);
2303 	return 0;
2304 }