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Date:: Fri Oct 28 20:39:21 2022 UTC
Message:: remove sendfd pledge promise from gotd repo_read process Have the parent process send one end of the pipe directly to gotsh(1), such that repo_write can run without "sendfd". Combining "sendfd" and "recvfd" in the same process is frowned upon. ok tracey
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1 /*
2  * Copyright (c) 2022 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/queue.h>
18 #include <sys/tree.h>
19 #include <sys/time.h>
20 #include <sys/types.h>
21 #include <sys/stat.h>
22 #include <sys/socket.h>
23 #include <sys/un.h>
24 #include <sys/wait.h>
25 
26 #include <fcntl.h>
27 #include <err.h>
28 #include <errno.h>
29 #include <event.h>
30 #include <limits.h>
31 #include <pwd.h>
32 #include <grp.h>
33 #include <imsg.h>
34 #include <sha1.h>
35 #include <signal.h>
36 #include <siphash.h>
37 #include <stdarg.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <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, "usage: %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 	/* Send pack pipe end 0 to repo_read. */
686 	if (gotd_imsg_compose_event(&client->repo_read->iev,
687 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[0],
688 	        &ipipe, sizeof(ipipe)) == -1) {
689 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
690 		close(pipe[1]);
691 		return err;
692 	}
693 
694 	/* Send pack pipe end 1 to gotsh(1) (expects just an fd, no data). */
695 	if (gotd_imsg_compose_event(&client->iev,
696 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[1], NULL, 0) == -1)
697 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
698 
699 	return err;
700 }
701 
702 static const struct got_error *
703 recv_packfile(struct gotd_client *client)
704 {
705 	const struct got_error *err = NULL;
706 	struct gotd_imsg_recv_packfile ipack;
707 	struct gotd_imsg_packfile_pipe ipipe;
708 	struct gotd_imsg_packidx_file ifile;
709 	char *basepath = NULL, *pack_path = NULL, *idx_path = NULL;
710 	int packfd = -1, idxfd = -1;
711 	int pipe[2] = { -1, -1 };
712 
713 	if (client->packfile_path) {
714 		return got_error_fmt(GOT_ERR_PRIVSEP_MSG,
715 		    "uid %d already has a pack file", client->euid);
716 	}
717 
718 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe) == -1)
719 		return got_error_from_errno("socketpair");
720 
721 	memset(&ipipe, 0, sizeof(ipipe));
722 	ipipe.client_id = client->id;
723 
724 	/* Send pack pipe end 0 to repo_write. */
725 	if (gotd_imsg_compose_event(&client->repo_write->iev,
726 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[0],
727 	        &ipipe, sizeof(ipipe)) == -1) {
728 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
729 		pipe[0] = -1;
730 		goto done;
731 	}
732 	pipe[0] = -1;
733 
734 	/* Send pack pipe end 1 to gotsh(1) (expects just an fd, no data). */
735 	if (gotd_imsg_compose_event(&client->iev,
736 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[1], NULL, 0) == -1)
737 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
738 	pipe[1] = -1;
739 
740 	if (asprintf(&basepath, "%s/%s/receiving-from-uid-%d.pack",
741 	    client->repo_write->chroot_path, GOT_OBJECTS_PACK_DIR,
742 	    client->euid) == -1) {
743 		err = got_error_from_errno("asprintf");
744 		goto done;
745 	}
746 
747 	err = got_opentemp_named_fd(&pack_path, &packfd, basepath);
748 	if (err)
749 		goto done;
750 
751 	free(basepath);
752 	if (asprintf(&basepath, "%s/%s/receiving-from-uid-%d.idx",
753 	    client->repo_write->chroot_path, GOT_OBJECTS_PACK_DIR,
754 	    client->euid) == -1) {
755 		err = got_error_from_errno("asprintf");
756 		basepath = NULL;
757 		goto done;
758 	}
759 	err = got_opentemp_named_fd(&idx_path, &idxfd, basepath);
760 	if (err)
761 		goto done;
762 
763 	memset(&ifile, 0, sizeof(ifile));
764 	ifile.client_id = client->id;
765 	if (gotd_imsg_compose_event(&client->repo_write->iev,
766 	    GOTD_IMSG_PACKIDX_FILE, PROC_GOTD, idxfd,
767 	    &ifile, sizeof(ifile)) == -1) {
768 		err = got_error_from_errno("imsg compose PACKIDX_FILE");
769 		idxfd = -1;
770 		goto done;
771 	}
772 	idxfd = -1;
773 
774 	memset(&ipack, 0, sizeof(ipack));
775 	ipack.client_id = client->id;
776 	if (client_has_capability(client, GOT_CAPA_REPORT_STATUS))
777 		ipack.report_status = 1;
778 
779 	if (gotd_imsg_compose_event(&client->repo_write->iev,
780 	    GOTD_IMSG_RECV_PACKFILE, PROC_GOTD, packfd,
781 	    &ipack, sizeof(ipack)) == -1) {
782 		err = got_error_from_errno("imsg compose RECV_PACKFILE");
783 		packfd = -1;
784 		goto done;
785 	}
786 	packfd = -1;
787 
788 done:
789 	free(basepath);
790 	if (pipe[0] != -1 && close(pipe[0]) == -1 && err == NULL)
791 		err = got_error_from_errno("close");
792 	if (pipe[1] != -1 && close(pipe[1]) == -1 && err == NULL)
793 		err = got_error_from_errno("close");
794 	if (packfd != -1 && close(packfd) == -1 && err == NULL)
795 		err = got_error_from_errno("close");
796 	if (idxfd != -1 && close(idxfd) == -1 && err == NULL)
797 		err = got_error_from_errno("close");
798 	if (err) {
799 		free(pack_path);
800 		free(idx_path);
801 	} else {
802 		client->packfile_path = pack_path;
803 		client->packidx_path = idx_path;
804 	}
805 	return err;
806 }
807 
808 static void
809 gotd_request(int fd, short events, void *arg)
810 {
811 	struct gotd_imsgev *iev = arg;
812 	struct imsgbuf *ibuf = &iev->ibuf;
813 	struct gotd_client *client = iev->handler_arg;
814 	const struct got_error *err = NULL;
815 	struct imsg imsg;
816 	ssize_t n;
817 
818 	if (events & EV_WRITE) {
819 		while (ibuf->w.queued) {
820 			n = msgbuf_write(&ibuf->w);
821 			if (n == -1 && errno == EPIPE) {
822 				/*
823 				 * The client has closed its socket.
824 				 * This can happen when Git clients are
825 				 * done sending pack file data.
826 				*/
827 				msgbuf_clear(&ibuf->w);
828 				continue;
829 			} else if (n == -1 && errno != EAGAIN) {
830 				err = got_error_from_errno("imsg_flush");
831 				disconnect_on_error(client, err);
832 				return;
833 			}
834 			if (n == 0) {
835 				/* Connection closed. */
836 				err = got_error(GOT_ERR_EOF);
837 				disconnect_on_error(client, err);
838 				return;
839 			}
840 		}
841 	}
842 
843 	if ((events & EV_READ) == 0)
844 		return;
845 
846 	memset(&imsg, 0, sizeof(imsg));
847 
848 	while (err == NULL) {
849 		err = gotd_imsg_recv(&imsg, ibuf, 0);
850 		if (err) {
851 			if (err->code == GOT_ERR_PRIVSEP_READ)
852 				err = NULL;
853 			break;
854 		}
855 
856 		evtimer_del(&client->tmo);
857 
858 		switch (imsg.hdr.type) {
859 		case GOTD_IMSG_LIST_REFS:
860 			if (client->state != GOTD_STATE_EXPECT_LIST_REFS) {
861 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
862 				    "unexpected list-refs request received");
863 				break;
864 			}
865 			err = forward_list_refs_request(client, &imsg);
866 			if (err)
867 				break;
868 			client->state = GOTD_STATE_EXPECT_CAPABILITIES;
869 			log_debug("uid %d: expecting capabilities",
870 			    client->euid);
871 			break;
872 		case GOTD_IMSG_CAPABILITIES:
873 			if (client->state != GOTD_STATE_EXPECT_CAPABILITIES) {
874 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
875 				    "unexpected capabilities received");
876 				break;
877 			}
878 			log_debug("receiving capabilities from uid %d",
879 			    client->euid);
880 			err = recv_capabilities(client, &imsg);
881 			break;
882 		case GOTD_IMSG_CAPABILITY:
883 			if (client->state != GOTD_STATE_EXPECT_CAPABILITIES) {
884 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
885 				    "unexpected capability received");
886 				break;
887 			}
888 			err = recv_capability(client, &imsg);
889 			if (err || client->ncapabilities < client->ncapa_alloc)
890 				break;
891 			if (client_is_reading(client)) {
892 				client->state = GOTD_STATE_EXPECT_WANT;
893 				log_debug("uid %d: expecting want-lines",
894 				    client->euid);
895 			} else if (client_is_writing(client)) {
896 				client->state = GOTD_STATE_EXPECT_REF_UPDATE;
897 				log_debug("uid %d: expecting ref-update-lines",
898 				    client->euid);
899 			} else
900 				fatalx("client %d is both reading and writing",
901 				    client->euid);
902 			break;
903 		case GOTD_IMSG_WANT:
904 			if (client->state != GOTD_STATE_EXPECT_WANT) {
905 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
906 				    "unexpected want-line received");
907 				break;
908 			}
909 			log_debug("received want-line from uid %d",
910 			    client->euid);
911 			err = ensure_client_is_reading(client);
912 			if (err)
913 				break;
914 			err = forward_want(client, &imsg);
915 			break;
916 		case GOTD_IMSG_REF_UPDATE:
917 			if (client->state != GOTD_STATE_EXPECT_REF_UPDATE) {
918 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
919 				    "unexpected ref-update-line received");
920 				break;
921 			}
922 			log_debug("received ref-update-line from uid %d",
923 			    client->euid);
924 			err = ensure_client_is_writing(client);
925 			if (err)
926 				break;
927 			err = forward_ref_update(client, &imsg);
928 			if (err)
929 				break;
930 			client->state = GOTD_STATE_EXPECT_MORE_REF_UPDATES;
931 			break;
932 		case GOTD_IMSG_HAVE:
933 			if (client->state != GOTD_STATE_EXPECT_HAVE) {
934 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
935 				    "unexpected have-line received");
936 				break;
937 			}
938 			log_debug("received have-line from uid %d",
939 			    client->euid);
940 			err = ensure_client_is_reading(client);
941 			if (err)
942 				break;
943 			err = forward_have(client, &imsg);
944 			if (err)
945 				break;
946 			break;
947 		case GOTD_IMSG_FLUSH:
948 			if (client->state == GOTD_STATE_EXPECT_WANT ||
949 			    client->state == GOTD_STATE_EXPECT_HAVE) {
950 				err = ensure_client_is_reading(client);
951 				if (err)
952 					break;
953 			} else if (client->state ==
954 			    GOTD_STATE_EXPECT_MORE_REF_UPDATES) {
955 				err = ensure_client_is_writing(client);
956 				if (err)
957 					break;
958 			} else {
959 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
960 				    "unexpected flush-pkt received");
961 				break;
962 			}
963 			log_debug("received flush-pkt from uid %d",
964 			    client->euid);
965 			if (client->state == GOTD_STATE_EXPECT_WANT) {
966 				client->state = GOTD_STATE_EXPECT_HAVE;
967 				log_debug("uid %d: expecting have-lines",
968 				    client->euid);
969 			} else if (client->state == GOTD_STATE_EXPECT_HAVE) {
970 				client->state = GOTD_STATE_EXPECT_DONE;
971 				log_debug("uid %d: expecting 'done'",
972 				    client->euid);
973 			} else if (client->state ==
974 			    GOTD_STATE_EXPECT_MORE_REF_UPDATES) {
975 				client->state = GOTD_STATE_EXPECT_PACKFILE;
976 				log_debug("uid %d: expecting packfile",
977 				    client->euid);
978 				err = recv_packfile(client);
979 			} else {
980 				/* should not happen, see above */
981 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
982 				    "unexpected client state");
983 				break;
984 			}
985 			break;
986 		case GOTD_IMSG_DONE:
987 			if (client->state != GOTD_STATE_EXPECT_HAVE &&
988 			    client->state != GOTD_STATE_EXPECT_DONE) {
989 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
990 				    "unexpected flush-pkt received");
991 				break;
992 			}
993 			log_debug("received 'done' from uid %d", client->euid);
994 			err = ensure_client_is_reading(client);
995 			if (err)
996 				break;
997 			client->state = GOTD_STATE_DONE;
998 			err = send_packfile(client);
999 			break;
1000 		default:
1001 			err = got_error(GOT_ERR_PRIVSEP_MSG);
1002 			break;
1003 		}
1004 
1005 		imsg_free(&imsg);
1006 	}
1007 
1008 	if (err) {
1009 		if (err->code != GOT_ERR_EOF ||
1010 		    client->state != GOTD_STATE_EXPECT_PACKFILE)
1011 			disconnect_on_error(client, err);
1012 	} else {
1013 		gotd_imsg_event_add(&client->iev);
1014 		evtimer_add(&client->tmo, &timeout);
1015 	}
1016 }
1017 
1018 static void
1019 gotd_request_timeout(int fd, short events, void *arg)
1020 {
1021 	struct gotd_client *client = arg;
1022 
1023 	log_debug("disconnecting uid %d due to timeout", client->euid);
1024 	disconnect(client);
1025 }
1026 
1027 static void
1028 gotd_accept(int fd, short event, void *arg)
1029 {
1030 	struct sockaddr_storage ss;
1031 	struct timeval backoff;
1032 	socklen_t len;
1033 	int s = -1;
1034 	struct gotd_client *client = NULL;
1035 	uid_t euid;
1036 	gid_t egid;
1037 
1038 	backoff.tv_sec = 1;
1039 	backoff.tv_usec = 0;
1040 
1041 	if (event_add(&gotd.ev, NULL) == -1) {
1042 		log_warn("event_add");
1043 		return;
1044 	}
1045 	if (event & EV_TIMEOUT)
1046 		return;
1047 
1048 	len = sizeof(ss);
1049 
1050 	s = accept_reserve(fd, (struct sockaddr *)&ss, &len, GOTD_FD_RESERVE,
1051 	    &inflight);
1052 
1053 	if (s == -1) {
1054 		switch (errno) {
1055 		case EINTR:
1056 		case EWOULDBLOCK:
1057 		case ECONNABORTED:
1058 			return;
1059 		case EMFILE:
1060 		case ENFILE:
1061 			event_del(&gotd.ev);
1062 			evtimer_add(&gotd.pause, &backoff);
1063 			return;
1064 		default:
1065 			log_warn("%s: accept", __func__);
1066 			return;
1067 		}
1068 	}
1069 
1070 	if (client_cnt >= GOTD_MAXCLIENTS)
1071 		goto err;
1072 
1073 	if (getpeereid(s, &euid, &egid) == -1) {
1074 		log_warn("%s: getpeereid", __func__);
1075 		goto err;
1076 	}
1077 
1078 	client = calloc(1, sizeof(*client));
1079 	if (client == NULL) {
1080 		log_warn("%s: calloc", __func__);
1081 		goto err;
1082 	}
1083 
1084 	client->state = GOTD_STATE_EXPECT_LIST_REFS;
1085 	client->id = get_client_id();
1086 	client->fd = s;
1087 	s = -1;
1088 	client->delta_cache_fd = -1;
1089 	client->euid = euid;
1090 	client->egid = egid;
1091 	client->nref_updates = -1;
1092 
1093 	imsg_init(&client->iev.ibuf, client->fd);
1094 	client->iev.handler = gotd_request;
1095 	client->iev.events = EV_READ;
1096 	client->iev.handler_arg = client;
1097 
1098 	event_set(&client->iev.ev, client->fd, EV_READ, gotd_request,
1099 	    &client->iev);
1100 	gotd_imsg_event_add(&client->iev);
1101 
1102 	evtimer_set(&client->tmo, gotd_request_timeout, client);
1103 
1104 	add_client(client);
1105 	log_debug("%s: new client uid %d connected on fd %d", __func__,
1106 	    client->euid, client->fd);
1107 	return;
1108 err:
1109 	inflight--;
1110 	if (s != -1)
1111 		close(s);
1112 	free(client);
1113 }
1114 
1115 static void
1116 gotd_accept_paused(int fd, short event, void *arg)
1117 {
1118 	event_add(&gotd.ev, NULL);
1119 }
1120 
1121 static const char *gotd_proc_names[PROC_MAX] = {
1122 	"parent",
1123 	"repo_read",
1124 	"repo_write"
1125 };
1126 
1127 static struct gotd_child_proc *
1128 get_proc_for_pid(pid_t pid)
1129 {
1130 	struct gotd_child_proc *proc;
1131 	int i;
1132 
1133 	for (i = 0; i < gotd.nprocs; i++) {
1134 		proc = &gotd.procs[i];
1135 		if (proc->pid == pid)
1136 			return proc;
1137 	}
1138 
1139 	return NULL;
1140 }
1141 
1142 static void
1143 kill_proc(struct gotd_child_proc *proc, int fatal)
1144 {
1145 	if (fatal) {
1146 		log_warnx("sending SIGKILL to PID %d", proc->pid);
1147 		kill(proc->pid, SIGKILL);
1148 	} else
1149 		kill(proc->pid, SIGTERM);
1150 }
1151 
1152 static void
1153 gotd_shutdown(void)
1154 {
1155 	pid_t	 pid;
1156 	int	 status, i;
1157 	struct gotd_child_proc *proc;
1158 
1159 	for (i = 0; i < gotd.nprocs; i++) {
1160 		proc = &gotd.procs[i];
1161 		msgbuf_clear(&proc->iev.ibuf.w);
1162 		close(proc->iev.ibuf.fd);
1163 		kill_proc(proc, 0);
1164 	}
1165 
1166 	log_debug("waiting for children to terminate");
1167 	do {
1168 		pid = wait(&status);
1169 		if (pid == -1) {
1170 			if (errno != EINTR && errno != ECHILD)
1171 				fatal("wait");
1172 		} else if (WIFSIGNALED(status)) {
1173 			proc = get_proc_for_pid(pid);
1174 			log_warnx("%s %s child process terminated; signal %d",
1175 			    proc ? gotd_proc_names[proc->type] : "",
1176 			    proc ? proc->chroot_path : "", WTERMSIG(status));
1177 		}	
1178 	} while (pid != -1 || (pid == -1 && errno == EINTR));
1179 
1180 	log_info("terminating");
1181 	exit(0);
1182 }
1183 
1184 void
1185 gotd_sighdlr(int sig, short event, void *arg)
1186 {
1187 	/*
1188 	 * Normal signal handler rules don't apply because libevent
1189 	 * decouples for us.
1190 	 */
1191 
1192 	switch (sig) {
1193 	case SIGHUP:
1194 		log_info("%s: ignoring SIGHUP", __func__);
1195 		break;
1196 	case SIGUSR1:
1197 		log_info("%s: ignoring SIGUSR1", __func__);
1198 		break;
1199 	case SIGTERM:
1200 	case SIGINT:
1201 		gotd_shutdown();
1202 		log_warnx("gotd terminating");
1203 		exit(0);
1204 		break;
1205 	default:
1206 		fatalx("unexpected signal");
1207 	}
1208 }
1209 
1210 static const struct got_error *
1211 ensure_proc_is_reading(struct gotd_client *client,
1212     struct gotd_child_proc *proc)
1213 {
1214 	if (!client_is_reading(client)) {
1215 		kill_proc(proc, 1);
1216 		return got_error_fmt(GOT_ERR_BAD_PACKET,
1217 		    "PID %d handled a read-request for uid %d but this "
1218 		    "user is not reading from a repository", proc->pid,
1219 		    client->euid);
1220 	}
1221 
1222 	return NULL;
1223 }
1224 
1225 static const struct got_error *
1226 ensure_proc_is_writing(struct gotd_client *client,
1227     struct gotd_child_proc *proc)
1228 {
1229 	if (!client_is_writing(client)) {
1230 		kill_proc(proc, 1);
1231 		return got_error_fmt(GOT_ERR_BAD_PACKET,
1232 		    "PID %d handled a write-request for uid %d but this "
1233 		    "user is not writing to a repository", proc->pid,
1234 		    client->euid);
1235 	}
1236 
1237 	return NULL;
1238 }
1239 
1240 static int
1241 verify_imsg_src(struct gotd_client *client, struct gotd_child_proc *proc,
1242     struct imsg *imsg)
1243 {
1244 	const struct got_error *err;
1245 	struct gotd_child_proc *client_proc;
1246 	int ret = 0;
1247 
1248 	client_proc = get_client_proc(client);
1249 	if (proc->pid != client_proc->pid) {
1250 		kill_proc(proc, 1);
1251 		log_warnx("received message from PID %d for uid %d, while "
1252 		    "PID %d is the process serving this user",
1253 		    proc->pid, client->euid, client_proc->pid);
1254 		return 0;
1255 	}
1256 
1257 	switch (imsg->hdr.type) {
1258 	case GOTD_IMSG_ERROR:
1259 		ret = 1;
1260 		break;
1261 	case GOTD_IMSG_PACKFILE_DONE:
1262 		err = ensure_proc_is_reading(client, proc);
1263 		if (err)
1264 			log_warnx("uid %d: %s", client->euid, err->msg);
1265 		else
1266 			ret = 1;
1267 		break;
1268 	case GOTD_IMSG_PACKFILE_INSTALL:
1269 	case GOTD_IMSG_REF_UPDATES_START:
1270 	case GOTD_IMSG_REF_UPDATE:
1271 		err = ensure_proc_is_writing(client, proc);
1272 		if (err)
1273 			log_warnx("uid %d: %s", client->euid, err->msg);
1274 		else
1275 			ret = 1;
1276 		break;
1277 	default:
1278 		log_debug("%s: unexpected imsg %d", __func__, imsg->hdr.type);
1279 		break;
1280 	}
1281 
1282 	return ret;
1283 }
1284 
1285 static const struct got_error *
1286 recv_packfile_done(uint32_t *client_id, struct imsg *imsg)
1287 {
1288 	struct gotd_imsg_packfile_done idone;
1289 	size_t datalen;
1290 
1291 	log_debug("packfile-done received");
1292 
1293 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1294 	if (datalen != sizeof(idone))
1295 		return got_error(GOT_ERR_PRIVSEP_LEN);
1296 	memcpy(&idone, imsg->data, sizeof(idone));
1297 
1298 	*client_id = idone.client_id;
1299 	return NULL;
1300 }
1301 
1302 static const struct got_error *
1303 recv_packfile_install(uint32_t *client_id, struct imsg *imsg)
1304 {
1305 	struct gotd_imsg_packfile_install inst;
1306 	size_t datalen;
1307 
1308 	log_debug("packfile-install received");
1309 
1310 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1311 	if (datalen != sizeof(inst))
1312 		return got_error(GOT_ERR_PRIVSEP_LEN);
1313 	memcpy(&inst, imsg->data, sizeof(inst));
1314 
1315 	*client_id = inst.client_id;
1316 	return NULL;
1317 }
1318 
1319 static const struct got_error *
1320 recv_ref_updates_start(uint32_t *client_id, struct imsg *imsg)
1321 {
1322 	struct gotd_imsg_ref_updates_start istart;
1323 	size_t datalen;
1324 
1325 	log_debug("ref-updates-start received");
1326 
1327 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1328 	if (datalen != sizeof(istart))
1329 		return got_error(GOT_ERR_PRIVSEP_LEN);
1330 	memcpy(&istart, imsg->data, sizeof(istart));
1331 
1332 	*client_id = istart.client_id;
1333 	return NULL;
1334 }
1335 
1336 static const struct got_error *
1337 recv_ref_update(uint32_t *client_id, struct imsg *imsg)
1338 {
1339 	struct gotd_imsg_ref_update iref;
1340 	size_t datalen;
1341 
1342 	log_debug("ref-update received");
1343 
1344 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1345 	if (datalen < sizeof(iref))
1346 		return got_error(GOT_ERR_PRIVSEP_LEN);
1347 	memcpy(&iref, imsg->data, sizeof(iref));
1348 
1349 	*client_id = iref.client_id;
1350 	return NULL;
1351 }
1352 
1353 static const struct got_error *
1354 send_ref_update_ok(struct gotd_client *client,
1355     struct gotd_imsg_ref_update *iref, const char *refname)
1356 {
1357 	struct gotd_imsg_ref_update_ok iok;
1358 	struct ibuf *wbuf;
1359 	size_t len;
1360 
1361 	memset(&iok, 0, sizeof(iok));
1362 	iok.client_id = client->id;
1363 	memcpy(iok.old_id, iref->old_id, SHA1_DIGEST_LENGTH);
1364 	memcpy(iok.new_id, iref->new_id, SHA1_DIGEST_LENGTH);
1365 	iok.name_len = strlen(refname);
1366 
1367 	len = sizeof(iok) + iok.name_len;
1368 	wbuf = imsg_create(&client->iev.ibuf, GOTD_IMSG_REF_UPDATE_OK,
1369 	    PROC_GOTD, gotd.pid, len);
1370 	if (wbuf == NULL)
1371 		return got_error_from_errno("imsg_create REF_UPDATE_OK");
1372 
1373 	if (imsg_add(wbuf, &iok, sizeof(iok)) == -1)
1374 		return got_error_from_errno("imsg_add REF_UPDATE_OK");
1375 	if (imsg_add(wbuf, refname, iok.name_len) == -1)
1376 		return got_error_from_errno("imsg_add REF_UPDATE_OK");
1377 
1378 	wbuf->fd = -1;
1379 	imsg_close(&client->iev.ibuf, wbuf);
1380 	gotd_imsg_event_add(&client->iev);
1381 	return NULL;
1382 }
1383 
1384 static void
1385 send_refs_updated(struct gotd_client *client)
1386 {
1387 	if (gotd_imsg_compose_event(&client->iev,
1388 	    GOTD_IMSG_REFS_UPDATED, PROC_GOTD, -1, NULL, 0) == -1)
1389 		log_warn("imsg compose REFS_UPDATED");
1390 }
1391 
1392 static const struct got_error *
1393 send_ref_update_ng(struct gotd_client *client,
1394     struct gotd_imsg_ref_update *iref, const char *refname,
1395     const char *reason)
1396 {
1397 	const struct got_error *ng_err;
1398 	struct gotd_imsg_ref_update_ng ing;
1399 	struct ibuf *wbuf;
1400 	size_t len;
1401 
1402 	memset(&ing, 0, sizeof(ing));
1403 	ing.client_id = client->id;
1404 	memcpy(ing.old_id, iref->old_id, SHA1_DIGEST_LENGTH);
1405 	memcpy(ing.new_id, iref->new_id, SHA1_DIGEST_LENGTH);
1406 	ing.name_len = strlen(refname);
1407 
1408 	ng_err = got_error_fmt(GOT_ERR_REF_BUSY, "%s", reason);
1409 	ing.reason_len = strlen(ng_err->msg);
1410 
1411 	len = sizeof(ing) + ing.name_len + ing.reason_len;
1412 	wbuf = imsg_create(&client->iev.ibuf, GOTD_IMSG_REF_UPDATE_NG,
1413 	    PROC_GOTD, gotd.pid, len);
1414 	if (wbuf == NULL)
1415 		return got_error_from_errno("imsg_create REF_UPDATE_NG");
1416 
1417 	if (imsg_add(wbuf, &ing, sizeof(ing)) == -1)
1418 		return got_error_from_errno("imsg_add REF_UPDATE_NG");
1419 	if (imsg_add(wbuf, refname, ing.name_len) == -1)
1420 		return got_error_from_errno("imsg_add REF_UPDATE_NG");
1421 	if (imsg_add(wbuf, ng_err->msg, ing.reason_len) == -1)
1422 		return got_error_from_errno("imsg_add REF_UPDATE_NG");
1423 
1424 	wbuf->fd = -1;
1425 	imsg_close(&client->iev.ibuf, wbuf);
1426 	gotd_imsg_event_add(&client->iev);
1427 	return NULL;
1428 }
1429 
1430 static const struct got_error *
1431 install_pack(struct gotd_client *client, const char *repo_path,
1432     struct imsg *imsg)
1433 {
1434 	const struct got_error *err = NULL;
1435 	struct gotd_imsg_packfile_install inst;
1436 	char hex[SHA1_DIGEST_STRING_LENGTH];
1437 	size_t datalen;
1438 	char *packfile_path = NULL, *packidx_path = NULL;
1439 
1440 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1441 	if (datalen != sizeof(inst))
1442 		return got_error(GOT_ERR_PRIVSEP_LEN);
1443 	memcpy(&inst, imsg->data, sizeof(inst));
1444 
1445 	if (client->packfile_path == NULL)
1446 		return got_error_msg(GOT_ERR_BAD_REQUEST,
1447 		    "client has no pack file");
1448 	if (client->packidx_path == NULL)
1449 		return got_error_msg(GOT_ERR_BAD_REQUEST,
1450 		    "client has no pack file index");
1451 
1452 	if (got_sha1_digest_to_str(inst.pack_sha1, hex, sizeof(hex)) == NULL)
1453 		return got_error_msg(GOT_ERR_NO_SPACE,
1454 		    "could not convert pack file SHA1 to hex");
1455 
1456 	if (asprintf(&packfile_path, "/%s/%s/pack-%s.pack",
1457 	    repo_path, GOT_OBJECTS_PACK_DIR, hex) == -1) {
1458 		err = got_error_from_errno("asprintf");
1459 		goto done;
1460 	}
1461 
1462 	if (asprintf(&packidx_path, "/%s/%s/pack-%s.idx",
1463 	    repo_path, GOT_OBJECTS_PACK_DIR, hex) == -1) {
1464 		err = got_error_from_errno("asprintf");
1465 		goto done;
1466 	}
1467 
1468 	if (rename(client->packfile_path, packfile_path) == -1) {
1469 		err = got_error_from_errno3("rename", client->packfile_path,
1470 		    packfile_path);
1471 		goto done;
1472 	}
1473 
1474 	free(client->packfile_path);
1475 	client->packfile_path = NULL;
1476 
1477 	if (rename(client->packidx_path, packidx_path) == -1) {
1478 		err = got_error_from_errno3("rename", client->packidx_path,
1479 		    packidx_path);
1480 		goto done;
1481 	}
1482 
1483 	free(client->packidx_path);
1484 	client->packidx_path = NULL;
1485 done:
1486 	free(packfile_path);
1487 	free(packidx_path);
1488 	return err;
1489 }
1490 
1491 static const struct got_error *
1492 begin_ref_updates(struct gotd_client *client, struct imsg *imsg)
1493 {
1494 	struct gotd_imsg_ref_updates_start istart;
1495 	size_t datalen;
1496 
1497 	if (client->nref_updates != -1)
1498 		return got_error(GOT_ERR_PRIVSEP_MSG);
1499 
1500 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1501 	if (datalen != sizeof(istart))
1502 		return got_error(GOT_ERR_PRIVSEP_LEN);
1503 	memcpy(&istart, imsg->data, sizeof(istart));
1504 
1505 	if (istart.nref_updates <= 0)
1506 		return got_error(GOT_ERR_PRIVSEP_MSG);
1507 
1508 	client->nref_updates = istart.nref_updates;
1509 	return NULL;
1510 }
1511 
1512 static const struct got_error *
1513 update_ref(struct gotd_client *client, const char *repo_path,
1514     struct imsg *imsg)
1515 {
1516 	const struct got_error *err = NULL;
1517 	struct got_repository *repo = NULL;
1518 	struct got_reference *ref = NULL;
1519 	struct gotd_imsg_ref_update iref;
1520 	struct got_object_id old_id, new_id;
1521 	struct got_object_id *id = NULL;
1522 	struct got_object *obj = NULL;
1523 	char *refname = NULL;
1524 	size_t datalen;
1525 	int locked = 0;
1526 
1527 	log_debug("update-ref from uid %d", client->euid);
1528 
1529 	if (client->nref_updates <= 0)
1530 		return got_error(GOT_ERR_PRIVSEP_MSG);
1531 
1532 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1533 	if (datalen < sizeof(iref))
1534 		return got_error(GOT_ERR_PRIVSEP_LEN);
1535 	memcpy(&iref, imsg->data, sizeof(iref));
1536 	if (datalen != sizeof(iref) + iref.name_len)
1537 		return got_error(GOT_ERR_PRIVSEP_LEN);
1538 	refname = malloc(iref.name_len + 1);
1539 	if (refname == NULL)
1540 		return got_error_from_errno("malloc");
1541 	memcpy(refname, imsg->data + sizeof(iref), iref.name_len);
1542 	refname[iref.name_len] = '\0';
1543 
1544 	log_debug("updating ref %s for uid %d", refname, client->euid);
1545 
1546 	err = got_repo_open(&repo, repo_path, NULL, NULL);
1547 	if (err)
1548 		goto done;
1549 
1550 	memcpy(old_id.sha1, iref.old_id, SHA1_DIGEST_LENGTH);
1551 	memcpy(new_id.sha1, iref.new_id, SHA1_DIGEST_LENGTH);
1552 	err = got_object_open(&obj, repo, &new_id);
1553 	if (err)
1554 		goto done;
1555 
1556 	if (iref.ref_is_new) {
1557 		err = got_ref_open(&ref, repo, refname, 0);
1558 		if (err) {
1559 			if (err->code != GOT_ERR_NOT_REF)
1560 				goto done;
1561 			err = got_ref_alloc(&ref, refname, &new_id);
1562 			if (err)
1563 				goto done;
1564 			err = got_ref_write(ref, repo); /* will lock/unlock */
1565 			if (err)
1566 				goto done;
1567 		} else {
1568 			err = got_error_fmt(GOT_ERR_REF_BUSY,
1569 			    "%s has been created by someone else "
1570 			    "while transaction was in progress",
1571 			    got_ref_get_name(ref));
1572 			goto done;
1573 		}
1574 	} else {
1575 		err = got_ref_open(&ref, repo, refname, 1 /* lock */);
1576 		if (err)
1577 			goto done;
1578 		locked = 1;
1579 
1580 		err = got_ref_resolve(&id, repo, ref);
1581 		if (err)
1582 			goto done;
1583 
1584 		if (got_object_id_cmp(id, &old_id) != 0) {
1585 			err = got_error_fmt(GOT_ERR_REF_BUSY,
1586 			    "%s has been modified by someone else "
1587 			    "while transaction was in progress",
1588 			    got_ref_get_name(ref));
1589 			goto done;
1590 		}
1591 
1592 		err = got_ref_change_ref(ref, &new_id);
1593 		if (err)
1594 			goto done;
1595 
1596 		err = got_ref_write(ref, repo);
1597 		if (err)
1598 			goto done;
1599 
1600 		free(id);
1601 		id = NULL;
1602 	}
1603 done:
1604 	if (err) {
1605 		if (err->code == GOT_ERR_LOCKFILE_TIMEOUT) {
1606 			err = got_error_fmt(GOT_ERR_LOCKFILE_TIMEOUT,
1607 			    "could not acquire exclusive file lock for %s",
1608 			    refname);
1609 		}
1610 		send_ref_update_ng(client, &iref, refname, err->msg);
1611 	} else
1612 		send_ref_update_ok(client, &iref, refname);
1613 
1614 	if (client->nref_updates > 0) {
1615 		client->nref_updates--;
1616 		if (client->nref_updates == 0)
1617 			send_refs_updated(client);
1618 
1619 	}
1620 	if (locked) {
1621 		const struct got_error *unlock_err;
1622 		unlock_err = got_ref_unlock(ref);
1623 		if (unlock_err && err == NULL)
1624 			err = unlock_err;
1625 	}
1626 	if (ref)
1627 		got_ref_close(ref);
1628 	if (obj)
1629 		got_object_close(obj);
1630 	if (repo)
1631 		got_repo_close(repo);
1632 	free(refname);
1633 	free(id);
1634 	return err;
1635 }
1636 
1637 static void
1638 gotd_dispatch(int fd, short event, void *arg)
1639 {
1640 	struct gotd_imsgev *iev = arg;
1641 	struct imsgbuf *ibuf = &iev->ibuf;
1642 	struct gotd_child_proc *proc = NULL;
1643 	ssize_t n;
1644 	int shut = 0;
1645 	struct imsg imsg;
1646 
1647 	if (event & EV_READ) {
1648 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1649 			fatal("imsg_read error");
1650 		if (n == 0) {
1651 			/* Connection closed. */
1652 			shut = 1;
1653 			goto done;
1654 		}
1655 	}
1656 
1657 	if (event & EV_WRITE) {
1658 		n = msgbuf_write(&ibuf->w);
1659 		if (n == -1 && errno != EAGAIN)
1660 			fatal("msgbuf_write");
1661 		if (n == 0) {
1662 			/* Connection closed. */
1663 			shut = 1;
1664 			goto done;
1665 		}
1666 	}
1667 
1668 	proc = find_proc_by_fd(fd);
1669 	if (proc == NULL)
1670 		fatalx("cannot find child process for fd %d", fd);
1671 
1672 	for (;;) {
1673 		const struct got_error *err = NULL;
1674 		struct gotd_client *client = NULL;
1675 		uint32_t client_id = 0;
1676 		int do_disconnect = 0;
1677 		int do_ref_updates = 0, do_ref_update = 0;
1678 		int do_packfile_install = 0;
1679 
1680 		if ((n = imsg_get(ibuf, &imsg)) == -1)
1681 			fatal("%s: imsg_get error", __func__);
1682 		if (n == 0)	/* No more messages. */
1683 			break;
1684 
1685 		switch (imsg.hdr.type) {
1686 		case GOTD_IMSG_ERROR:
1687 			do_disconnect = 1;
1688 			err = gotd_imsg_recv_error(&client_id, &imsg);
1689 			break;
1690 		case GOTD_IMSG_PACKFILE_DONE:
1691 			do_disconnect = 1;
1692 			err = recv_packfile_done(&client_id, &imsg);
1693 			break;
1694 		case GOTD_IMSG_PACKFILE_INSTALL:
1695 			err = recv_packfile_install(&client_id, &imsg);
1696 			if (err == NULL)
1697 				do_packfile_install = 1;
1698 			break;
1699 		case GOTD_IMSG_REF_UPDATES_START:
1700 			err = recv_ref_updates_start(&client_id, &imsg);
1701 			if (err == NULL)
1702 				do_ref_updates = 1;
1703 			break;
1704 		case GOTD_IMSG_REF_UPDATE:
1705 			err = recv_ref_update(&client_id, &imsg);
1706 			if (err == NULL)
1707 				do_ref_update = 1;
1708 			break;
1709 		default:
1710 			log_debug("unexpected imsg %d", imsg.hdr.type);
1711 			break;
1712 		}
1713 
1714 		client = find_client(client_id);
1715 		if (client == NULL) {
1716 			log_warnx("%s: client not found", __func__);
1717 			imsg_free(&imsg);
1718 			continue;
1719 		}
1720 
1721 		if (!verify_imsg_src(client, proc, &imsg)) {
1722 			log_debug("dropping imsg type %d from PID %d",
1723 			    imsg.hdr.type, proc->pid);
1724 			imsg_free(&imsg);
1725 			continue;
1726 		}
1727 		if (err)
1728 			log_warnx("uid %d: %s", client->euid, err->msg);
1729 
1730 		if (do_disconnect) {
1731 			if (err)
1732 				disconnect_on_error(client, err);
1733 			else
1734 				disconnect(client);
1735 		} else if (do_packfile_install)
1736 			err = install_pack(client, proc->chroot_path, &imsg);
1737 		else if (do_ref_updates)
1738 			err = begin_ref_updates(client, &imsg);
1739 		else if (do_ref_update)
1740 			err = update_ref(client, proc->chroot_path, &imsg);
1741 
1742 		if (err)
1743 			log_warnx("uid %d: %s", client->euid, err->msg);
1744 		imsg_free(&imsg);
1745 	}
1746 done:
1747 	if (!shut) {
1748 		gotd_imsg_event_add(iev);
1749 	} else {
1750 		/* This pipe is dead. Remove its event handler */
1751 		event_del(&iev->ev);
1752 		event_loopexit(NULL);
1753 	}
1754 }
1755 
1756 static pid_t
1757 start_child(enum gotd_procid proc_id, const char *chroot_path,
1758     char *argv0, int fd, int daemonize, int verbosity)
1759 {
1760 	char	*argv[9];
1761 	int	 argc = 0;
1762 	pid_t	 pid;
1763 
1764 	switch (pid = fork()) {
1765 	case -1:
1766 		fatal("cannot fork");
1767 	case 0:
1768 		break;
1769 	default:
1770 		close(fd);
1771 		return pid;
1772 	}
1773 
1774 	if (fd != GOTD_SOCK_FILENO) {
1775 		if (dup2(fd, GOTD_SOCK_FILENO) == -1)
1776 			fatal("cannot setup imsg fd");
1777 	} else if (fcntl(fd, F_SETFD, 0) == -1)
1778 		fatal("cannot setup imsg fd");
1779 
1780 	argv[argc++] = argv0;
1781 	switch (proc_id) {
1782 	case PROC_REPO_READ:
1783 		argv[argc++] = (char *)"-R";
1784 		break;
1785 	case PROC_REPO_WRITE:
1786 		argv[argc++] = (char *)"-W";
1787 		break;
1788 	default:
1789 		fatalx("invalid process id %d", proc_id);
1790 	}
1791 
1792 	argv[argc++] = (char *)"-P";
1793 	argv[argc++] = (char *)chroot_path;
1794 
1795 	if (!daemonize)
1796 		argv[argc++] = (char *)"-d";
1797 	if (verbosity > 0)
1798 		argv[argc++] = (char *)"-v";
1799 	if (verbosity > 1)
1800 		argv[argc++] = (char *)"-v";
1801 	argv[argc++] = NULL;
1802 
1803 	execvp(argv0, argv);
1804 	fatal("execvp");
1805 }
1806 
1807 static void
1808 start_repo_children(struct gotd *gotd, char *argv0, int daemonize,
1809     int verbosity)
1810 {
1811 	struct gotd_repo *repo = NULL;
1812 	struct gotd_child_proc *proc;
1813 	int i;
1814 
1815 	/*
1816 	 * XXX For now, use one reader and one writer per repository.
1817 	 * This should be changed to N readers + M writers.
1818 	 */
1819 	gotd->nprocs = gotd->nrepos * 2;
1820 	gotd->procs = calloc(gotd->nprocs, sizeof(*gotd->procs));
1821 	if (gotd->procs == NULL)
1822 		fatal("calloc");
1823 	for (i = 0; i < gotd->nprocs; i++) {
1824 		if (repo == NULL)
1825 			repo = TAILQ_FIRST(&gotd->repos);
1826 		proc = &gotd->procs[i];
1827 		if (i < gotd->nrepos)
1828 			proc->type = PROC_REPO_READ;
1829 		else
1830 			proc->type = PROC_REPO_WRITE;
1831 		if (strlcpy(proc->repo_name, repo->name,
1832 		    sizeof(proc->repo_name)) >= sizeof(proc->repo_name))
1833 			fatalx("repository name too long: %s", repo->name);
1834 		log_debug("adding repository %s", repo->name);
1835 		if (realpath(repo->path, proc->chroot_path) == NULL)
1836 			fatal("%s", repo->path);
1837 		if (socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK,
1838 		    PF_UNSPEC, proc->pipe) == -1)
1839 			fatal("socketpair");
1840 		proc->pid = start_child(proc->type, proc->chroot_path, argv0,
1841 		    proc->pipe[1], daemonize, verbosity);
1842 		imsg_init(&proc->iev.ibuf, proc->pipe[0]);
1843 		log_debug("proc %s %s is on fd %d",
1844 		    gotd_proc_names[proc->type], proc->chroot_path,
1845 		    proc->pipe[0]);
1846 		proc->iev.handler = gotd_dispatch;
1847 		proc->iev.events = EV_READ;
1848 		proc->iev.handler_arg = NULL;
1849 		event_set(&proc->iev.ev, proc->iev.ibuf.fd, EV_READ,
1850 		    gotd_dispatch, &proc->iev);
1851 
1852 		repo = TAILQ_NEXT(repo, entry);
1853 	}
1854 }
1855 
1856 static void
1857 apply_unveil(void)
1858 {
1859 	struct gotd_repo *repo;
1860 
1861 	TAILQ_FOREACH(repo, &gotd.repos, entry) {
1862 		if (unveil(repo->path, "rwc") == -1)
1863 			fatal("unveil %s", repo->path);
1864 	}
1865 
1866 	if (unveil(GOT_TMPDIR_STR, "rwc") == -1)
1867 		fatal("unveil %s", GOT_TMPDIR_STR);
1868 
1869 	if (unveil(NULL, NULL) == -1)
1870 		fatal("unveil");
1871 }
1872 
1873 int
1874 main(int argc, char **argv)
1875 {
1876 	const struct got_error *error = NULL;
1877 	int ch, fd = -1, daemonize = 1, verbosity = 0, noaction = 0;
1878 	const char *confpath = GOTD_CONF_PATH;
1879 	char *argv0 = argv[0];
1880 	char title[2048];
1881 	gid_t groups[NGROUPS_MAX + 1];
1882 	int ngroups = NGROUPS_MAX + 1;
1883 	struct passwd *pw = NULL;
1884 	struct group *gr = NULL;
1885 	char *repo_path = NULL;
1886 	enum gotd_procid proc_id = PROC_GOTD;
1887 	struct event evsigint, evsigterm, evsighup, evsigusr1;
1888 	int *pack_fds = NULL, *temp_fds = NULL;
1889 
1890 	log_init(1, LOG_DAEMON); /* Log to stderr until daemonized. */
1891 
1892 	while ((ch = getopt(argc, argv, "df:nP:RvW")) != -1) {
1893 		switch (ch) {
1894 		case 'd':
1895 			daemonize = 0;
1896 			break;
1897 		case 'f':
1898 			confpath = optarg;
1899 			break;
1900 		case 'n':
1901 			noaction = 1;
1902 			break;
1903 		case 'P':
1904 			repo_path = realpath(optarg, NULL);
1905 			if (repo_path == NULL)
1906 				fatal("realpath '%s'", optarg);
1907 			break;
1908 		case 'R':
1909 			proc_id = PROC_REPO_READ;
1910 			break;
1911 		case 'v':
1912 			if (verbosity < 3)
1913 				verbosity++;
1914 			break;
1915 		case 'W':
1916 			proc_id = PROC_REPO_WRITE;
1917 			break;
1918 		default:
1919 			usage();
1920 		}
1921 	}
1922 
1923 	argc -= optind;
1924 	argv += optind;
1925 
1926 	if (argc != 0)
1927 		usage();
1928 
1929 	if (geteuid())
1930 		fatalx("need root privileges");
1931 
1932 	log_init(daemonize ? 0 : 1, LOG_DAEMON);
1933 	log_setverbose(verbosity);
1934 
1935 	if (parse_config(confpath, proc_id, &gotd) != 0)
1936 		return 1;
1937 
1938 	if (proc_id == PROC_GOTD &&
1939 	    (gotd.nrepos == 0 || TAILQ_EMPTY(&gotd.repos)))
1940 		fatalx("no repository defined in configuration file");
1941 
1942 	pw = getpwnam(gotd.user_name);
1943 	if (pw == NULL)
1944 		fatal("getpwuid: user %s not found", gotd.user_name);
1945 
1946 	if (pw->pw_uid == 0) {
1947 		fatalx("cannot run %s as %s: the user running %s "
1948 		    "must not be the superuser",
1949 		    getprogname(), pw->pw_name, getprogname());
1950 	}
1951 
1952 	if (getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups) == -1)
1953 		log_warnx("group membership list truncated");
1954 
1955 	gr = match_group(groups, ngroups, gotd.unix_group_name);
1956 	if (gr == NULL) {
1957 		fatalx("cannot start %s: the user running %s "
1958 		    "must be a secondary member of group %s",
1959 		    getprogname(), getprogname(), gotd.unix_group_name);
1960 	}
1961 	if (gr->gr_gid == pw->pw_gid) {
1962 		fatalx("cannot start %s: the user running %s "
1963 		    "must be a secondary member of group %s, but "
1964 		    "%s is the user's primary group",
1965 		    getprogname(), getprogname(), gotd.unix_group_name,
1966 		    gotd.unix_group_name);
1967 	}
1968 
1969 	if (proc_id == PROC_GOTD &&
1970 	    !got_path_is_absolute(gotd.unix_socket_path))
1971 		fatalx("bad unix socket path \"%s\": must be an absolute path",
1972 		    gotd.unix_socket_path);
1973 
1974 	if (noaction)
1975 		return 0;
1976 
1977 	if (proc_id == PROC_GOTD && verbosity) {
1978 		log_info("socket: %s", gotd.unix_socket_path);
1979 		log_info("user: %s", pw->pw_name);
1980 		log_info("secondary group: %s", gr->gr_name);
1981 
1982 		fd = unix_socket_listen(gotd.unix_socket_path, pw->pw_uid,
1983 		    gr->gr_gid);
1984 		if (fd == -1) {
1985 			fatal("cannot listen on unix socket %s",
1986 			    gotd.unix_socket_path);
1987 		}
1988 	}
1989 
1990 	if (proc_id == PROC_GOTD) {
1991 		gotd.pid = getpid();
1992 		snprintf(title, sizeof(title), "%s", gotd_proc_names[proc_id]);
1993 		start_repo_children(&gotd, argv0, daemonize, verbosity);
1994 		arc4random_buf(&clients_hash_key, sizeof(clients_hash_key));
1995 		if (daemonize && daemon(0, 0) == -1)
1996 			fatal("daemon");
1997 	} else if (proc_id == PROC_REPO_READ || proc_id == PROC_REPO_WRITE) {
1998 		error = got_repo_pack_fds_open(&pack_fds);
1999 		if (error != NULL)
2000 			fatalx("cannot open pack tempfiles: %s", error->msg);
2001 		error = got_repo_temp_fds_open(&temp_fds);
2002 		if (error != NULL)
2003 			fatalx("cannot open pack tempfiles: %s", error->msg);
2004 		if (repo_path == NULL)
2005 			fatalx("repository path not specified");
2006 		snprintf(title, sizeof(title), "%s %s",
2007 		    gotd_proc_names[proc_id], repo_path);
2008 		if (chroot(repo_path) == -1)
2009 			fatal("chroot");
2010 		if (chdir("/") == -1)
2011 			fatal("chdir(\"/\")");
2012 		if (daemonize && daemon(1, 0) == -1)
2013 			fatal("daemon");
2014 	} else
2015 		fatal("invalid process id %d", proc_id);
2016 
2017 	setproctitle("%s", title);
2018 	log_procinit(title);
2019 
2020 	/* Drop root privileges. */
2021 	if (setgid(pw->pw_gid) == -1)
2022 		fatal("setgid %d failed", pw->pw_gid);
2023 	if (setuid(pw->pw_uid) == -1)
2024 		fatal("setuid %d failed", pw->pw_uid);
2025 
2026 	event_init();
2027 
2028 	switch (proc_id) {
2029 	case PROC_GOTD:
2030 #ifndef PROFILE
2031 		if (pledge("stdio rpath wpath cpath proc getpw sendfd recvfd "
2032 		    "fattr flock unix unveil", NULL) == -1)
2033 			err(1, "pledge");
2034 #endif
2035 		break;
2036 	case PROC_REPO_READ:
2037 #ifndef PROFILE
2038 		if (pledge("stdio rpath recvfd", NULL) == -1)
2039 			err(1, "pledge");
2040 #endif
2041 		repo_read_main(title, pack_fds, temp_fds);
2042 		/* NOTREACHED */
2043 		exit(0);
2044 	case PROC_REPO_WRITE:
2045 #ifndef PROFILE
2046 		if (pledge("stdio rpath recvfd", NULL) == -1)
2047 			err(1, "pledge");
2048 #endif
2049 		repo_write_main(title, pack_fds, temp_fds);
2050 		/* NOTREACHED */
2051 		exit(0);
2052 	default:
2053 		fatal("invalid process id %d", proc_id);
2054 	}
2055 
2056 	if (proc_id != PROC_GOTD)
2057 		fatal("invalid process id %d", proc_id);
2058 
2059 	apply_unveil();
2060 
2061 	signal_set(&evsigint, SIGINT, gotd_sighdlr, NULL);
2062 	signal_set(&evsigterm, SIGTERM, gotd_sighdlr, NULL);
2063 	signal_set(&evsighup, SIGHUP, gotd_sighdlr, NULL);
2064 	signal_set(&evsigusr1, SIGUSR1, gotd_sighdlr, NULL);
2065 	signal(SIGPIPE, SIG_IGN);
2066 
2067 	signal_add(&evsigint, NULL);
2068 	signal_add(&evsigterm, NULL);
2069 	signal_add(&evsighup, NULL);
2070 	signal_add(&evsigusr1, NULL);
2071 
2072 	event_set(&gotd.ev, fd, EV_READ | EV_PERSIST, gotd_accept, NULL);
2073 	if (event_add(&gotd.ev, NULL))
2074 		fatalx("event add");
2075 	evtimer_set(&gotd.pause, gotd_accept_paused, NULL);
2076 
2077 	event_dispatch();
2078 
2079 	if (fd != -1)
2080 		close(fd);
2081 	if (pack_fds)
2082 		got_repo_pack_fds_close(pack_fds);
2083 	free(repo_path);
2084 	return 0;
2085 }