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