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Date:: Thu Nov 17 10:20:50 2022 UTC
Message:: tedu Ted's copyright added to gotd.c by accident; doas-derived code is in auth.c
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1 /*
2  * Copyright (c) 2022 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/queue.h>
18 #include <sys/tree.h>
19 #include <sys/time.h>
20 #include <sys/types.h>
21 #include <sys/stat.h>
22 #include <sys/socket.h>
23 #include <sys/un.h>
24 #include <sys/wait.h>
25 
26 #include <fcntl.h>
27 #include <err.h>
28 #include <errno.h>
29 #include <event.h>
30 #include <limits.h>
31 #include <pwd.h>
32 #include <grp.h>
33 #include <imsg.h>
34 #include <sha1.h>
35 #include <signal.h>
36 #include <siphash.h>
37 #include <stdarg.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <syslog.h>
42 #include <unistd.h>
43 
44 #include "got_error.h"
45 #include "got_opentemp.h"
46 #include "got_path.h"
47 #include "got_repository.h"
48 #include "got_object.h"
49 #include "got_reference.h"
50 
51 #include "got_lib_delta.h"
52 #include "got_lib_object.h"
53 #include "got_lib_object_cache.h"
54 #include "got_lib_sha1.h"
55 #include "got_lib_gitproto.h"
56 #include "got_lib_pack.h"
57 #include "got_lib_repository.h"
58 
59 #include "gotd.h"
60 #include "log.h"
61 #include "auth.h"
62 #include "repo_read.h"
63 #include "repo_write.h"
64 
65 #ifndef nitems
66 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
67 #endif
68 
69 struct gotd_client {
70 	STAILQ_ENTRY(gotd_client)	 entry;
71 	enum gotd_client_state		 state;
72 	struct gotd_client_capability	*capabilities;
73 	size_t				 ncapa_alloc;
74 	size_t				 ncapabilities;
75 	uint32_t			 id;
76 	int				 fd;
77 	int				 delta_cache_fd;
78 	struct gotd_imsgev		 iev;
79 	struct event			 tmo;
80 	uid_t				 euid;
81 	gid_t				 egid;
82 	struct gotd_child_proc		*repo_read;
83 	struct gotd_child_proc		*repo_write;
84 	char				*packfile_path;
85 	char				*packidx_path;
86 	int				 nref_updates;
87 };
88 STAILQ_HEAD(gotd_clients, gotd_client);
89 
90 static struct gotd_clients gotd_clients[GOTD_CLIENT_TABLE_SIZE];
91 static SIPHASH_KEY clients_hash_key;
92 volatile int client_cnt;
93 static struct timeval timeout = { 3600, 0 };
94 static int inflight;
95 static struct gotd gotd;
96 
97 void gotd_sighdlr(int sig, short event, void *arg);
98 static void gotd_shutdown(void);
99 
100 __dead static void
101 usage()
102 {
103 	fprintf(stderr, "usage: %s [-dv] [-f config-file]\n", getprogname());
104 	exit(1);
105 }
106 
107 static int
108 unix_socket_listen(const char *unix_socket_path, uid_t uid, gid_t gid)
109 {
110 	struct sockaddr_un sun;
111 	int fd = -1;
112 	mode_t old_umask, mode;
113 
114 	fd = socket(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK| SOCK_CLOEXEC, 0);
115 	if (fd == -1) {
116 		log_warn("socket");
117 		return -1;
118 	}
119 
120 	sun.sun_family = AF_UNIX;
121 	if (strlcpy(sun.sun_path, unix_socket_path,
122 	    sizeof(sun.sun_path)) >= sizeof(sun.sun_path)) {
123 		log_warnx("%s: name too long", unix_socket_path);
124 		close(fd);
125 		return -1;
126 	}
127 
128 	if (unlink(unix_socket_path) == -1) {
129 		if (errno != ENOENT) {
130 			log_warn("unlink %s", unix_socket_path);
131 			close(fd);
132 			return -1;
133 		}
134 	}
135 
136 	old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);
137 	mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP;
138 
139 	if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
140 		log_warn("bind: %s", unix_socket_path);
141 		close(fd);
142 		umask(old_umask);
143 		return -1;
144 	}
145 
146 	umask(old_umask);
147 
148 	if (chmod(unix_socket_path, mode) == -1) {
149 		log_warn("chmod %o %s", mode, unix_socket_path);
150 		close(fd);
151 		unlink(unix_socket_path);
152 		return -1;
153 	}
154 
155 	if (chown(unix_socket_path, uid, gid) == -1) {
156 		log_warn("chown %s uid=%d gid=%d", unix_socket_path, uid, gid);
157 		close(fd);
158 		unlink(unix_socket_path);
159 		return -1;
160 	}
161 
162 	if (listen(fd, GOTD_UNIX_SOCKET_BACKLOG) == -1) {
163 		log_warn("listen");
164 		close(fd);
165 		unlink(unix_socket_path);
166 		return -1;
167 	}
168 
169 	return fd;
170 }
171 
172 static struct group *
173 match_group(gid_t *groups, int ngroups, const char *unix_group_name)
174 {
175 	struct group *gr;
176 	int i;
177 
178 	for (i = 0; i < ngroups; i++) {
179 		gr = getgrgid(groups[i]);
180 		if (gr == NULL) {
181 			log_warn("getgrgid %d", groups[i]);
182 			continue;
183 		}
184 		if (strcmp(gr->gr_name, unix_group_name) == 0)
185 			return gr;
186 	}
187 
188 	return NULL;
189 }
190 
191 static int
192 accept_reserve(int fd, struct sockaddr *addr, socklen_t *addrlen,
193     int reserve, volatile int *counter)
194 {
195 	int ret;
196 
197 	if (getdtablecount() + reserve +
198 	    ((*counter + 1) * GOTD_FD_NEEDED) >= getdtablesize()) {
199 		log_debug("inflight fds exceeded");
200 		errno = EMFILE;
201 		return -1;
202 	}
203 
204 	if ((ret = accept4(fd, addr, addrlen,
205 	    SOCK_NONBLOCK | SOCK_CLOEXEC)) > -1) {
206 		(*counter)++;
207 	}
208 
209 	return ret;
210 }
211 
212 static uint64_t
213 client_hash(uint32_t client_id)
214 {
215 	return SipHash24(&clients_hash_key, &client_id, sizeof(client_id));
216 }
217 
218 static void
219 add_client(struct gotd_client *client)
220 {
221 	uint64_t slot = client_hash(client->id) % nitems(gotd_clients);
222 	STAILQ_INSERT_HEAD(&gotd_clients[slot], client, entry);
223 	client_cnt++;
224 }
225 
226 static struct gotd_client *
227 find_client(uint32_t client_id)
228 {
229 	uint64_t slot;
230 	struct gotd_client *c;
231 
232 	slot = client_hash(client_id) % nitems(gotd_clients);
233 	STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
234 		if (c->id == client_id)
235 			return c;
236 	}
237 
238 	return NULL;
239 }
240 
241 static uint32_t
242 get_client_id(void)
243 {
244 	int duplicate = 0;
245 	uint32_t id;
246 
247 	do {
248 		id = arc4random();
249 		duplicate = (find_client(id) != NULL);
250 	} while (duplicate || id == 0);
251 
252 	return id;
253 }
254 
255 static struct gotd_child_proc *
256 get_client_proc(struct gotd_client *client)
257 {
258 	if (client->repo_read && client->repo_write) {
259 		fatalx("uid %d is reading and writing in the same session",
260 		    client->euid);
261 		/* NOTREACHED */
262 	}
263 
264 	if (client->repo_read)
265 		return client->repo_read;
266 	else if (client->repo_write)
267 		return client->repo_write;
268 
269 	return NULL;
270 }
271 
272 static int
273 client_is_reading(struct gotd_client *client)
274 {
275 	return client->repo_read != NULL;
276 }
277 
278 static int
279 client_is_writing(struct gotd_client *client)
280 {
281 	return client->repo_write != NULL;
282 }
283 
284 static const struct got_error *
285 ensure_client_is_reading(struct gotd_client *client)
286 {
287 	if (!client_is_reading(client)) {
288 		return got_error_fmt(GOT_ERR_BAD_PACKET,
289 		    "uid %d made a read-request but is not reading from "
290 		    "a repository", client->euid);
291 	}
292 
293 	return NULL;
294 }
295 
296 static const struct got_error *
297 ensure_client_is_writing(struct gotd_client *client)
298 {
299 	if (!client_is_writing(client)) {
300 		return got_error_fmt(GOT_ERR_BAD_PACKET,
301 		    "uid %d made a write-request but is not writing to "
302 		    "a repository", client->euid);
303 	}
304 
305 	return NULL;
306 }
307 
308 static const struct got_error *
309 ensure_client_is_not_writing(struct gotd_client *client)
310 {
311 	if (client_is_writing(client)) {
312 		return got_error_fmt(GOT_ERR_BAD_PACKET,
313 		    "uid %d made a read-request but is writing to "
314 		    "a repository", client->euid);
315 	}
316 
317 	return NULL;
318 }
319 
320 static const struct got_error *
321 ensure_client_is_not_reading(struct gotd_client *client)
322 {
323 	if (client_is_reading(client)) {
324 		return got_error_fmt(GOT_ERR_BAD_PACKET,
325 		    "uid %d made a write-request but is reading from "
326 		    "a repository", client->euid);
327 	}
328 
329 	return NULL;
330 }
331 
332 static void
333 disconnect(struct gotd_client *client)
334 {
335 	struct gotd_imsg_disconnect idisconnect;
336 	struct gotd_child_proc *proc = get_client_proc(client);
337 	uint64_t slot;
338 
339 	log_debug("uid %d: disconnecting", client->euid);
340 
341 	idisconnect.client_id = client->id;
342 	if (proc) {
343 		if (gotd_imsg_compose_event(&proc->iev,
344 		    GOTD_IMSG_DISCONNECT, PROC_GOTD, -1,
345 		    &idisconnect, sizeof(idisconnect)) == -1)
346 			log_warn("imsg compose DISCONNECT");
347 	}
348 	slot = client_hash(client->id) % nitems(gotd_clients);
349 	STAILQ_REMOVE(&gotd_clients[slot], client, gotd_client, entry);
350 	imsg_clear(&client->iev.ibuf);
351 	event_del(&client->iev.ev);
352 	evtimer_del(&client->tmo);
353 	close(client->fd);
354 	if (client->delta_cache_fd != -1)
355 		close(client->delta_cache_fd);
356 	if (client->packfile_path) {
357 		if (unlink(client->packfile_path) == -1 && errno != ENOENT)
358 			log_warn("unlink %s: ", client->packfile_path);
359 		free(client->packfile_path);
360 	}
361 	if (client->packidx_path) {
362 		if (unlink(client->packidx_path) == -1 && errno != ENOENT)
363 			log_warn("unlink %s: ", client->packidx_path);
364 		free(client->packidx_path);
365 	}
366 	free(client->capabilities);
367 	free(client);
368 	inflight--;
369 	client_cnt--;
370 }
371 
372 static void
373 disconnect_on_error(struct gotd_client *client, const struct got_error *err)
374 {
375 	struct imsgbuf ibuf;
376 
377 	log_warnx("uid %d: %s", client->euid, err->msg);
378 	if (err->code != GOT_ERR_EOF) {
379 		imsg_init(&ibuf, client->fd);
380 		gotd_imsg_send_error(&ibuf, 0, PROC_GOTD, err);
381 		imsg_clear(&ibuf);
382 	}
383 	disconnect(client);
384 }
385 
386 static const struct got_error *
387 send_repo_info(struct gotd_imsgev *iev, struct gotd_repo *repo)
388 {
389 	const struct got_error *err = NULL;
390 	struct gotd_imsg_info_repo irepo;
391 
392 	memset(&irepo, 0, sizeof(irepo));
393 
394 	if (strlcpy(irepo.repo_name, repo->name, sizeof(irepo.repo_name))
395 	    >= sizeof(irepo.repo_name))
396 		return got_error_msg(GOT_ERR_NO_SPACE, "repo name too long");
397 	if (strlcpy(irepo.repo_path, repo->path, sizeof(irepo.repo_path))
398 	    >= sizeof(irepo.repo_path))
399 		return got_error_msg(GOT_ERR_NO_SPACE, "repo path too long");
400 
401 	if (gotd_imsg_compose_event(iev, GOTD_IMSG_INFO_REPO, PROC_GOTD, -1,
402 	    &irepo, sizeof(irepo)) == -1) {
403 		err = got_error_from_errno("imsg compose INFO_REPO");
404 		if (err)
405 			return err;
406 	}
407 
408 	return NULL;
409 }
410 
411 static const struct got_error *
412 send_capability(struct gotd_client_capability *capa, struct gotd_imsgev* iev)
413 {
414 	const struct got_error *err = NULL;
415 	struct gotd_imsg_capability icapa;
416 	size_t len;
417 	struct ibuf *wbuf;
418 
419 	memset(&icapa, 0, sizeof(icapa));
420 
421 	icapa.key_len = strlen(capa->key);
422 	len = sizeof(icapa) + icapa.key_len;
423 	if (capa->value) {
424 		icapa.value_len = strlen(capa->value);
425 		len += icapa.value_len;
426 	}
427 
428 	wbuf = imsg_create(&iev->ibuf, GOTD_IMSG_CAPABILITY, 0, 0, len);
429 	if (wbuf == NULL) {
430 		err = got_error_from_errno("imsg_create CAPABILITY");
431 		return err;
432 	}
433 
434 	if (imsg_add(wbuf, &icapa, sizeof(icapa)) == -1)
435 		return got_error_from_errno("imsg_add CAPABILITY");
436 	if (imsg_add(wbuf, capa->key, icapa.key_len) == -1)
437 		return got_error_from_errno("imsg_add CAPABILITY");
438 	if (capa->value) {
439 		if (imsg_add(wbuf, capa->value, icapa.value_len) == -1)
440 			return got_error_from_errno("imsg_add CAPABILITY");
441 	}
442 
443 	wbuf->fd = -1;
444 	imsg_close(&iev->ibuf, wbuf);
445 
446 	gotd_imsg_event_add(iev);
447 
448 	return NULL;
449 }
450 
451 static const struct got_error *
452 send_client_info(struct gotd_imsgev *iev, struct gotd_client *client)
453 {
454 	const struct got_error *err = NULL;
455 	struct gotd_imsg_info_client iclient;
456 	struct gotd_child_proc *proc;
457 	size_t i;
458 
459 	memset(&iclient, 0, sizeof(iclient));
460 	iclient.euid = client->euid;
461 	iclient.egid = client->egid;
462 
463 	proc = get_client_proc(client);
464 	if (proc) {
465 		if (strlcpy(iclient.repo_name, proc->chroot_path,
466 		    sizeof(iclient.repo_name)) >= sizeof(iclient.repo_name)) {
467 			return got_error_msg(GOT_ERR_NO_SPACE,
468 			    "repo name too long");
469 		}
470 		if (client_is_writing(client))
471 			iclient.is_writing = 1;
472 	}
473 
474 	iclient.state = client->state;
475 	iclient.ncapabilities = client->ncapabilities;
476 
477 	if (gotd_imsg_compose_event(iev, GOTD_IMSG_INFO_CLIENT, PROC_GOTD, -1,
478 	    &iclient, sizeof(iclient)) == -1) {
479 		err = got_error_from_errno("imsg compose INFO_CLIENT");
480 		if (err)
481 			return err;
482 	}
483 
484 	for (i = 0; i < client->ncapabilities; i++) {
485 		struct gotd_client_capability *capa;
486 		capa = &client->capabilities[i];
487 		err = send_capability(capa, iev);
488 		if (err)
489 			return err;
490 	}
491 
492 	return NULL;
493 }
494 
495 static const struct got_error *
496 send_info(struct gotd_client *client)
497 {
498 	const struct got_error *err = NULL;
499 	struct gotd_imsg_info info;
500 	uint64_t slot;
501 	struct gotd_repo *repo;
502 
503 	info.pid = gotd.pid;
504 	info.verbosity = gotd.verbosity;
505 	info.nrepos = gotd.nrepos;
506 	info.nclients = client_cnt - 1;
507 
508 	if (gotd_imsg_compose_event(&client->iev, GOTD_IMSG_INFO, PROC_GOTD, -1,
509 	    &info, sizeof(info)) == -1) {
510 		err = got_error_from_errno("imsg compose INFO");
511 		if (err)
512 			return err;
513 	}
514 
515 	TAILQ_FOREACH(repo, &gotd.repos, entry) {
516 		err = send_repo_info(&client->iev, repo);
517 		if (err)
518 			return err;
519 	}
520 
521 	for (slot = 0; slot < nitems(gotd_clients); slot++) {
522 		struct gotd_client *c;
523 		STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
524 			if (c->id == client->id)
525 				continue;
526 			err = send_client_info(&client->iev, c);
527 			if (err)
528 				return err;
529 		}
530 	}
531 
532 	return NULL;
533 }
534 
535 static const struct got_error *
536 stop_gotd(struct gotd_client *client)
537 {
538 
539 	if (client->euid != 0)
540 		return got_error_set_errno(EPERM, "stop");
541 
542 	gotd_shutdown();
543 	/* NOTREACHED */
544 	return NULL;
545 }
546 
547 static struct gotd_repo *
548 find_repo_by_name(const char *repo_name)
549 {
550 	struct gotd_repo *repo;
551 	size_t namelen;
552 
553 	TAILQ_FOREACH(repo, &gotd.repos, entry) {
554 		namelen = strlen(repo->name);
555 		if (strncmp(repo->name, repo_name, namelen) != 0)
556 			continue;
557 		if (repo_name[namelen] == '\0' ||
558 		    strcmp(&repo_name[namelen], ".git") == 0)
559 			return repo;
560 	}
561 
562 	return NULL;
563 }
564 
565 static struct gotd_child_proc *
566 find_proc_by_repo_name(enum gotd_procid proc_id, const char *repo_name)
567 {
568 	struct gotd_child_proc *proc;
569 	int i;
570 	size_t namelen;
571 
572 	for (i = 0; i < gotd.nprocs; i++) {
573 		proc = &gotd.procs[i];
574 		if (proc->type != proc_id)
575 			continue;
576 		namelen = strlen(proc->repo_name);
577 		if (strncmp(proc->repo_name, repo_name, namelen) != 0)
578 			continue;
579 		if (repo_name[namelen] == '\0' ||
580 		    strcmp(&repo_name[namelen], ".git") == 0)
581 			return proc;
582 	}
583 
584 	return NULL;
585 }
586 
587 static struct gotd_child_proc *
588 find_proc_by_fd(int fd)
589 {
590 	struct gotd_child_proc *proc;
591 	int i;
592 
593 	for (i = 0; i < gotd.nprocs; i++) {
594 		proc = &gotd.procs[i];
595 		if (proc->iev.ibuf.fd == fd)
596 			return proc;
597 	}
598 
599 	return NULL;
600 }
601 
602 static const struct got_error *
603 forward_list_refs_request(struct gotd_client *client, struct imsg *imsg)
604 {
605 	const struct got_error *err;
606 	struct gotd_imsg_list_refs ireq;
607 	struct gotd_imsg_list_refs_internal ilref;
608 	struct gotd_repo *repo = NULL;
609 	struct gotd_child_proc *proc = NULL;
610 	size_t datalen;
611 	int fd = -1;
612 
613 	log_debug("list-refs request from uid %d", client->euid);
614 
615 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
616 	if (datalen != sizeof(ireq))
617 		return got_error(GOT_ERR_PRIVSEP_LEN);
618 
619 	memcpy(&ireq, imsg->data, datalen);
620 
621 	memset(&ilref, 0, sizeof(ilref));
622 	ilref.client_id = client->id;
623 
624 	if (ireq.client_is_reading) {
625 		err = ensure_client_is_not_writing(client);
626 		if (err)
627 			return err;
628 		repo = find_repo_by_name(ireq.repo_name);
629 		if (repo == NULL)
630 			return got_error(GOT_ERR_NOT_GIT_REPO);
631 		err = gotd_auth_check(&repo->rules, repo->name,
632 		    client->euid, client->egid, GOTD_AUTH_READ);
633 		if (err)
634 			return err;
635 		client->repo_read = find_proc_by_repo_name(PROC_REPO_READ,
636 		    ireq.repo_name);
637 		if (client->repo_read == NULL)
638 			return got_error(GOT_ERR_NOT_GIT_REPO);
639 	} else {
640 		err = ensure_client_is_not_reading(client);
641 		if (err)
642 			return err;
643 		repo = find_repo_by_name(ireq.repo_name);
644 		if (repo == NULL)
645 			return got_error(GOT_ERR_NOT_GIT_REPO);
646 		err = gotd_auth_check(&repo->rules, repo->name, client->euid,
647 		    client->egid, GOTD_AUTH_READ | GOTD_AUTH_WRITE);
648 		if (err)
649 			return err;
650 		client->repo_write = find_proc_by_repo_name(PROC_REPO_WRITE,
651 		    ireq.repo_name);
652 		if (client->repo_write == NULL)
653 			return got_error(GOT_ERR_NOT_GIT_REPO);
654 	}
655 
656 	fd = dup(client->fd);
657 	if (fd == -1)
658 		return got_error_from_errno("dup");
659 
660 	proc = get_client_proc(client);
661 	if (proc == NULL)
662 		fatalx("no process found for uid %d", client->euid);
663 	if (gotd_imsg_compose_event(&proc->iev,
664 	    GOTD_IMSG_LIST_REFS_INTERNAL, PROC_GOTD, fd,
665 	    &ilref, sizeof(ilref)) == -1) {
666 		err = got_error_from_errno("imsg compose WANT");
667 		close(fd);
668 		return err;
669 	}
670 
671 	return NULL;
672 }
673 
674 static const struct got_error *
675 forward_want(struct gotd_client *client, struct imsg *imsg)
676 {
677 	struct gotd_imsg_want ireq;
678 	struct gotd_imsg_want iwant;
679 	size_t datalen;
680 
681 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
682 	if (datalen != sizeof(ireq))
683 		return got_error(GOT_ERR_PRIVSEP_LEN);
684 
685 	memcpy(&ireq, imsg->data, datalen);
686 
687 	memset(&iwant, 0, sizeof(iwant));
688 	memcpy(iwant.object_id, ireq.object_id, SHA1_DIGEST_LENGTH);
689 	iwant.client_id = client->id;
690 
691 	if (gotd_imsg_compose_event(&client->repo_read->iev, GOTD_IMSG_WANT,
692 	    PROC_GOTD, -1, &iwant, sizeof(iwant)) == -1)
693 		return got_error_from_errno("imsg compose WANT");
694 
695 	return NULL;
696 }
697 
698 static const struct got_error *
699 forward_ref_update(struct gotd_client *client, struct imsg *imsg)
700 {
701 	const struct got_error *err = NULL;
702 	struct gotd_imsg_ref_update ireq;
703 	struct gotd_imsg_ref_update *iref = NULL;
704 	size_t datalen;
705 
706 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
707 	if (datalen < sizeof(ireq))
708 		return got_error(GOT_ERR_PRIVSEP_LEN);
709 	memcpy(&ireq, imsg->data, sizeof(ireq));
710 	if (datalen != sizeof(ireq) + ireq.name_len)
711 		return got_error(GOT_ERR_PRIVSEP_LEN);
712 
713 	iref = malloc(datalen);
714 	if (iref == NULL)
715 		return got_error_from_errno("malloc");
716 	memcpy(iref, imsg->data, datalen);
717 
718 	iref->client_id = client->id;
719 	if (gotd_imsg_compose_event(&client->repo_write->iev,
720 	    GOTD_IMSG_REF_UPDATE, PROC_GOTD, -1, iref, datalen) == -1)
721 		err = got_error_from_errno("imsg compose REF_UPDATE");
722 	free(iref);
723 	return err;
724 }
725 
726 static const struct got_error *
727 forward_have(struct gotd_client *client, struct imsg *imsg)
728 {
729 	struct gotd_imsg_have ireq;
730 	struct gotd_imsg_have ihave;
731 	size_t datalen;
732 
733 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
734 	if (datalen != sizeof(ireq))
735 		return got_error(GOT_ERR_PRIVSEP_LEN);
736 
737 	memcpy(&ireq, imsg->data, datalen);
738 
739 	memset(&ihave, 0, sizeof(ihave));
740 	memcpy(ihave.object_id, ireq.object_id, SHA1_DIGEST_LENGTH);
741 	ihave.client_id = client->id;
742 
743 	if (gotd_imsg_compose_event(&client->repo_read->iev, GOTD_IMSG_HAVE,
744 	    PROC_GOTD, -1, &ihave, sizeof(ihave)) == -1)
745 		return got_error_from_errno("imsg compose HAVE");
746 
747 	return NULL;
748 }
749 
750 static int
751 client_has_capability(struct gotd_client *client, const char *capastr)
752 {
753 	struct gotd_client_capability *capa;
754 	size_t i;
755 
756 	if (client->ncapabilities == 0)
757 		return 0;
758 
759 	for (i = 0; i < client->ncapabilities; i++) {
760 		capa = &client->capabilities[i];
761 		if (strcmp(capa->key, capastr) == 0)
762 			return 1;
763 	}
764 
765 	return 0;
766 }
767 
768 static const struct got_error *
769 recv_capabilities(struct gotd_client *client, struct imsg *imsg)
770 {
771 	struct gotd_imsg_capabilities icapas;
772 	size_t datalen;
773 
774 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
775 	if (datalen != sizeof(icapas))
776 		return got_error(GOT_ERR_PRIVSEP_LEN);
777 	memcpy(&icapas, imsg->data, sizeof(icapas));
778 
779 	client->ncapa_alloc = icapas.ncapabilities;
780 	client->capabilities = calloc(client->ncapa_alloc,
781 	    sizeof(*client->capabilities));
782 	if (client->capabilities == NULL) {
783 		client->ncapa_alloc = 0;
784 		return got_error_from_errno("calloc");
785 	}
786 
787 	log_debug("expecting %zu capabilities from uid %d",
788 	    client->ncapa_alloc, client->euid);
789 	return NULL;
790 }
791 
792 static const struct got_error *
793 recv_capability(struct gotd_client *client, struct imsg *imsg)
794 {
795 	struct gotd_imsg_capability icapa;
796 	struct gotd_client_capability *capa;
797 	size_t datalen;
798 	char *key, *value = NULL;
799 
800 	if (client->capabilities == NULL ||
801 	    client->ncapabilities >= client->ncapa_alloc) {
802 		return got_error_msg(GOT_ERR_BAD_REQUEST,
803 		    "unexpected capability received");
804 	}
805 
806 	memset(&icapa, 0, sizeof(icapa));
807 
808 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
809 	if (datalen < sizeof(icapa))
810 		return got_error(GOT_ERR_PRIVSEP_LEN);
811 	memcpy(&icapa, imsg->data, sizeof(icapa));
812 
813 	if (datalen != sizeof(icapa) + icapa.key_len + icapa.value_len)
814 		return got_error(GOT_ERR_PRIVSEP_LEN);
815 
816 	key = malloc(icapa.key_len + 1);
817 	if (key == NULL)
818 		return got_error_from_errno("malloc");
819 	if (icapa.value_len > 0) {
820 		value = malloc(icapa.value_len + 1);
821 		if (value == NULL) {
822 			free(key);
823 			return got_error_from_errno("malloc");
824 		}
825 	}
826 
827 	memcpy(key, imsg->data + sizeof(icapa), icapa.key_len);
828 	key[icapa.key_len] = '\0';
829 	if (value) {
830 		memcpy(value, imsg->data + sizeof(icapa) + icapa.key_len,
831 		    icapa.value_len);
832 		value[icapa.value_len] = '\0';
833 	}
834 
835 	capa = &client->capabilities[client->ncapabilities++];
836 	capa->key = key;
837 	capa->value = value;
838 
839 	if (value)
840 		log_debug("uid %d: capability %s=%s", client->euid, key, value);
841 	else
842 		log_debug("uid %d: capability %s", client->euid, key);
843 
844 	return NULL;
845 }
846 
847 static const struct got_error *
848 send_packfile(struct gotd_client *client)
849 {
850 	const struct got_error *err = NULL;
851 	struct gotd_imsg_send_packfile ipack;
852 	struct gotd_imsg_packfile_pipe ipipe;
853 	int pipe[2];
854 
855 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe) == -1)
856 		return got_error_from_errno("socketpair");
857 
858 	memset(&ipack, 0, sizeof(ipack));
859 	memset(&ipipe, 0, sizeof(ipipe));
860 
861 	ipack.client_id = client->id;
862 	if (client_has_capability(client, GOT_CAPA_SIDE_BAND_64K))
863 		ipack.report_progress = 1;
864 
865 	client->delta_cache_fd = got_opentempfd();
866 	if (client->delta_cache_fd == -1)
867 		return got_error_from_errno("got_opentempfd");
868 
869 	if (gotd_imsg_compose_event(&client->repo_read->iev,
870 	    GOTD_IMSG_SEND_PACKFILE, PROC_GOTD, client->delta_cache_fd,
871 	    &ipack, sizeof(ipack)) == -1) {
872 		err = got_error_from_errno("imsg compose SEND_PACKFILE");
873 		close(pipe[0]);
874 		close(pipe[1]);
875 		return err;
876 	}
877 
878 	ipipe.client_id = client->id;
879 
880 	/* Send pack pipe end 0 to repo_read. */
881 	if (gotd_imsg_compose_event(&client->repo_read->iev,
882 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[0],
883 	        &ipipe, sizeof(ipipe)) == -1) {
884 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
885 		close(pipe[1]);
886 		return err;
887 	}
888 
889 	/* Send pack pipe end 1 to gotsh(1) (expects just an fd, no data). */
890 	if (gotd_imsg_compose_event(&client->iev,
891 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[1], NULL, 0) == -1)
892 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
893 
894 	return err;
895 }
896 
897 static const struct got_error *
898 recv_packfile(struct gotd_client *client)
899 {
900 	const struct got_error *err = NULL;
901 	struct gotd_imsg_recv_packfile ipack;
902 	struct gotd_imsg_packfile_pipe ipipe;
903 	struct gotd_imsg_packidx_file ifile;
904 	char *basepath = NULL, *pack_path = NULL, *idx_path = NULL;
905 	int packfd = -1, idxfd = -1;
906 	int pipe[2] = { -1, -1 };
907 
908 	if (client->packfile_path) {
909 		return got_error_fmt(GOT_ERR_PRIVSEP_MSG,
910 		    "uid %d already has a pack file", client->euid);
911 	}
912 
913 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe) == -1)
914 		return got_error_from_errno("socketpair");
915 
916 	memset(&ipipe, 0, sizeof(ipipe));
917 	ipipe.client_id = client->id;
918 
919 	/* Send pack pipe end 0 to repo_write. */
920 	if (gotd_imsg_compose_event(&client->repo_write->iev,
921 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[0],
922 	        &ipipe, sizeof(ipipe)) == -1) {
923 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
924 		pipe[0] = -1;
925 		goto done;
926 	}
927 	pipe[0] = -1;
928 
929 	/* Send pack pipe end 1 to gotsh(1) (expects just an fd, no data). */
930 	if (gotd_imsg_compose_event(&client->iev,
931 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[1], NULL, 0) == -1)
932 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
933 	pipe[1] = -1;
934 
935 	if (asprintf(&basepath, "%s/%s/receiving-from-uid-%d.pack",
936 	    client->repo_write->chroot_path, GOT_OBJECTS_PACK_DIR,
937 	    client->euid) == -1) {
938 		err = got_error_from_errno("asprintf");
939 		goto done;
940 	}
941 
942 	err = got_opentemp_named_fd(&pack_path, &packfd, basepath, "");
943 	if (err)
944 		goto done;
945 
946 	free(basepath);
947 	if (asprintf(&basepath, "%s/%s/receiving-from-uid-%d.idx",
948 	    client->repo_write->chroot_path, GOT_OBJECTS_PACK_DIR,
949 	    client->euid) == -1) {
950 		err = got_error_from_errno("asprintf");
951 		basepath = NULL;
952 		goto done;
953 	}
954 	err = got_opentemp_named_fd(&idx_path, &idxfd, basepath, "");
955 	if (err)
956 		goto done;
957 
958 	memset(&ifile, 0, sizeof(ifile));
959 	ifile.client_id = client->id;
960 	if (gotd_imsg_compose_event(&client->repo_write->iev,
961 	    GOTD_IMSG_PACKIDX_FILE, PROC_GOTD, idxfd,
962 	    &ifile, sizeof(ifile)) == -1) {
963 		err = got_error_from_errno("imsg compose PACKIDX_FILE");
964 		idxfd = -1;
965 		goto done;
966 	}
967 	idxfd = -1;
968 
969 	memset(&ipack, 0, sizeof(ipack));
970 	ipack.client_id = client->id;
971 	if (client_has_capability(client, GOT_CAPA_REPORT_STATUS))
972 		ipack.report_status = 1;
973 
974 	if (gotd_imsg_compose_event(&client->repo_write->iev,
975 	    GOTD_IMSG_RECV_PACKFILE, PROC_GOTD, packfd,
976 	    &ipack, sizeof(ipack)) == -1) {
977 		err = got_error_from_errno("imsg compose RECV_PACKFILE");
978 		packfd = -1;
979 		goto done;
980 	}
981 	packfd = -1;
982 
983 done:
984 	free(basepath);
985 	if (pipe[0] != -1 && close(pipe[0]) == -1 && err == NULL)
986 		err = got_error_from_errno("close");
987 	if (pipe[1] != -1 && close(pipe[1]) == -1 && err == NULL)
988 		err = got_error_from_errno("close");
989 	if (packfd != -1 && close(packfd) == -1 && err == NULL)
990 		err = got_error_from_errno("close");
991 	if (idxfd != -1 && close(idxfd) == -1 && err == NULL)
992 		err = got_error_from_errno("close");
993 	if (err) {
994 		free(pack_path);
995 		free(idx_path);
996 	} else {
997 		client->packfile_path = pack_path;
998 		client->packidx_path = idx_path;
999 	}
1000 	return err;
1001 }
1002 
1003 static void
1004 gotd_request(int fd, short events, void *arg)
1005 {
1006 	struct gotd_imsgev *iev = arg;
1007 	struct imsgbuf *ibuf = &iev->ibuf;
1008 	struct gotd_client *client = iev->handler_arg;
1009 	const struct got_error *err = NULL;
1010 	struct imsg imsg;
1011 	ssize_t n;
1012 
1013 	if (events & EV_WRITE) {
1014 		while (ibuf->w.queued) {
1015 			n = msgbuf_write(&ibuf->w);
1016 			if (n == -1 && errno == EPIPE) {
1017 				/*
1018 				 * The client has closed its socket.
1019 				 * This can happen when Git clients are
1020 				 * done sending pack file data.
1021 				*/
1022 				msgbuf_clear(&ibuf->w);
1023 				continue;
1024 			} else if (n == -1 && errno != EAGAIN) {
1025 				err = got_error_from_errno("imsg_flush");
1026 				disconnect_on_error(client, err);
1027 				return;
1028 			}
1029 			if (n == 0) {
1030 				/* Connection closed. */
1031 				err = got_error(GOT_ERR_EOF);
1032 				disconnect_on_error(client, err);
1033 				return;
1034 			}
1035 		}
1036 
1037 		/* Disconnect gotctl(8) now that messages have been sent. */
1038 		if (!client_is_reading(client) && !client_is_writing(client)) {
1039 			disconnect(client);
1040 			return;
1041 		}
1042 	}
1043 
1044 	if ((events & EV_READ) == 0)
1045 		return;
1046 
1047 	memset(&imsg, 0, sizeof(imsg));
1048 
1049 	while (err == NULL) {
1050 		err = gotd_imsg_recv(&imsg, ibuf, 0);
1051 		if (err) {
1052 			if (err->code == GOT_ERR_PRIVSEP_READ)
1053 				err = NULL;
1054 			break;
1055 		}
1056 
1057 		evtimer_del(&client->tmo);
1058 
1059 		switch (imsg.hdr.type) {
1060 		case GOTD_IMSG_INFO:
1061 			err = send_info(client);
1062 			break;
1063 		case GOTD_IMSG_STOP:
1064 			err = stop_gotd(client);
1065 			break;
1066 		case GOTD_IMSG_LIST_REFS:
1067 			if (client->state != GOTD_STATE_EXPECT_LIST_REFS) {
1068 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1069 				    "unexpected list-refs request received");
1070 				break;
1071 			}
1072 			err = forward_list_refs_request(client, &imsg);
1073 			if (err)
1074 				break;
1075 			client->state = GOTD_STATE_EXPECT_CAPABILITIES;
1076 			log_debug("uid %d: expecting capabilities",
1077 			    client->euid);
1078 			break;
1079 		case GOTD_IMSG_CAPABILITIES:
1080 			if (client->state != GOTD_STATE_EXPECT_CAPABILITIES) {
1081 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1082 				    "unexpected capabilities received");
1083 				break;
1084 			}
1085 			log_debug("receiving capabilities from uid %d",
1086 			    client->euid);
1087 			err = recv_capabilities(client, &imsg);
1088 			break;
1089 		case GOTD_IMSG_CAPABILITY:
1090 			if (client->state != GOTD_STATE_EXPECT_CAPABILITIES) {
1091 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1092 				    "unexpected capability received");
1093 				break;
1094 			}
1095 			err = recv_capability(client, &imsg);
1096 			if (err || client->ncapabilities < client->ncapa_alloc)
1097 				break;
1098 			if (client_is_reading(client)) {
1099 				client->state = GOTD_STATE_EXPECT_WANT;
1100 				log_debug("uid %d: expecting want-lines",
1101 				    client->euid);
1102 			} else if (client_is_writing(client)) {
1103 				client->state = GOTD_STATE_EXPECT_REF_UPDATE;
1104 				log_debug("uid %d: expecting ref-update-lines",
1105 				    client->euid);
1106 			} else
1107 				fatalx("client %d is both reading and writing",
1108 				    client->euid);
1109 			break;
1110 		case GOTD_IMSG_WANT:
1111 			if (client->state != GOTD_STATE_EXPECT_WANT) {
1112 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1113 				    "unexpected want-line received");
1114 				break;
1115 			}
1116 			log_debug("received want-line from uid %d",
1117 			    client->euid);
1118 			err = ensure_client_is_reading(client);
1119 			if (err)
1120 				break;
1121 			err = forward_want(client, &imsg);
1122 			break;
1123 		case GOTD_IMSG_REF_UPDATE:
1124 			if (client->state != GOTD_STATE_EXPECT_REF_UPDATE) {
1125 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1126 				    "unexpected ref-update-line received");
1127 				break;
1128 			}
1129 			log_debug("received ref-update-line from uid %d",
1130 			    client->euid);
1131 			err = ensure_client_is_writing(client);
1132 			if (err)
1133 				break;
1134 			err = forward_ref_update(client, &imsg);
1135 			if (err)
1136 				break;
1137 			client->state = GOTD_STATE_EXPECT_MORE_REF_UPDATES;
1138 			break;
1139 		case GOTD_IMSG_HAVE:
1140 			if (client->state != GOTD_STATE_EXPECT_HAVE) {
1141 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1142 				    "unexpected have-line received");
1143 				break;
1144 			}
1145 			log_debug("received have-line from uid %d",
1146 			    client->euid);
1147 			err = ensure_client_is_reading(client);
1148 			if (err)
1149 				break;
1150 			err = forward_have(client, &imsg);
1151 			if (err)
1152 				break;
1153 			break;
1154 		case GOTD_IMSG_FLUSH:
1155 			if (client->state == GOTD_STATE_EXPECT_WANT ||
1156 			    client->state == GOTD_STATE_EXPECT_HAVE) {
1157 				err = ensure_client_is_reading(client);
1158 				if (err)
1159 					break;
1160 			} else if (client->state ==
1161 			    GOTD_STATE_EXPECT_MORE_REF_UPDATES) {
1162 				err = ensure_client_is_writing(client);
1163 				if (err)
1164 					break;
1165 			} else {
1166 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1167 				    "unexpected flush-pkt received");
1168 				break;
1169 			}
1170 			log_debug("received flush-pkt from uid %d",
1171 			    client->euid);
1172 			if (client->state == GOTD_STATE_EXPECT_WANT) {
1173 				client->state = GOTD_STATE_EXPECT_HAVE;
1174 				log_debug("uid %d: expecting have-lines",
1175 				    client->euid);
1176 			} else if (client->state == GOTD_STATE_EXPECT_HAVE) {
1177 				client->state = GOTD_STATE_EXPECT_DONE;
1178 				log_debug("uid %d: expecting 'done'",
1179 				    client->euid);
1180 			} else if (client->state ==
1181 			    GOTD_STATE_EXPECT_MORE_REF_UPDATES) {
1182 				client->state = GOTD_STATE_EXPECT_PACKFILE;
1183 				log_debug("uid %d: expecting packfile",
1184 				    client->euid);
1185 				err = recv_packfile(client);
1186 			} else {
1187 				/* should not happen, see above */
1188 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1189 				    "unexpected client state");
1190 				break;
1191 			}
1192 			break;
1193 		case GOTD_IMSG_DONE:
1194 			if (client->state != GOTD_STATE_EXPECT_HAVE &&
1195 			    client->state != GOTD_STATE_EXPECT_DONE) {
1196 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1197 				    "unexpected flush-pkt received");
1198 				break;
1199 			}
1200 			log_debug("received 'done' from uid %d", client->euid);
1201 			err = ensure_client_is_reading(client);
1202 			if (err)
1203 				break;
1204 			client->state = GOTD_STATE_DONE;
1205 			err = send_packfile(client);
1206 			break;
1207 		default:
1208 			err = got_error(GOT_ERR_PRIVSEP_MSG);
1209 			break;
1210 		}
1211 
1212 		imsg_free(&imsg);
1213 	}
1214 
1215 	if (err) {
1216 		if (err->code != GOT_ERR_EOF ||
1217 		    client->state != GOTD_STATE_EXPECT_PACKFILE)
1218 			disconnect_on_error(client, err);
1219 	} else {
1220 		gotd_imsg_event_add(&client->iev);
1221 		evtimer_add(&client->tmo, &timeout);
1222 	}
1223 }
1224 
1225 static void
1226 gotd_request_timeout(int fd, short events, void *arg)
1227 {
1228 	struct gotd_client *client = arg;
1229 
1230 	log_debug("disconnecting uid %d due to timeout", client->euid);
1231 	disconnect(client);
1232 }
1233 
1234 static void
1235 gotd_accept(int fd, short event, void *arg)
1236 {
1237 	struct sockaddr_storage ss;
1238 	struct timeval backoff;
1239 	socklen_t len;
1240 	int s = -1;
1241 	struct gotd_client *client = NULL;
1242 	uid_t euid;
1243 	gid_t egid;
1244 
1245 	backoff.tv_sec = 1;
1246 	backoff.tv_usec = 0;
1247 
1248 	if (event_add(&gotd.ev, NULL) == -1) {
1249 		log_warn("event_add");
1250 		return;
1251 	}
1252 	if (event & EV_TIMEOUT)
1253 		return;
1254 
1255 	len = sizeof(ss);
1256 
1257 	s = accept_reserve(fd, (struct sockaddr *)&ss, &len, GOTD_FD_RESERVE,
1258 	    &inflight);
1259 
1260 	if (s == -1) {
1261 		switch (errno) {
1262 		case EINTR:
1263 		case EWOULDBLOCK:
1264 		case ECONNABORTED:
1265 			return;
1266 		case EMFILE:
1267 		case ENFILE:
1268 			event_del(&gotd.ev);
1269 			evtimer_add(&gotd.pause, &backoff);
1270 			return;
1271 		default:
1272 			log_warn("%s: accept", __func__);
1273 			return;
1274 		}
1275 	}
1276 
1277 	if (client_cnt >= GOTD_MAXCLIENTS)
1278 		goto err;
1279 
1280 	if (getpeereid(s, &euid, &egid) == -1) {
1281 		log_warn("%s: getpeereid", __func__);
1282 		goto err;
1283 	}
1284 
1285 	client = calloc(1, sizeof(*client));
1286 	if (client == NULL) {
1287 		log_warn("%s: calloc", __func__);
1288 		goto err;
1289 	}
1290 
1291 	client->state = GOTD_STATE_EXPECT_LIST_REFS;
1292 	client->id = get_client_id();
1293 	client->fd = s;
1294 	s = -1;
1295 	client->delta_cache_fd = -1;
1296 	client->euid = euid;
1297 	client->egid = egid;
1298 	client->nref_updates = -1;
1299 
1300 	imsg_init(&client->iev.ibuf, client->fd);
1301 	client->iev.handler = gotd_request;
1302 	client->iev.events = EV_READ;
1303 	client->iev.handler_arg = client;
1304 
1305 	event_set(&client->iev.ev, client->fd, EV_READ, gotd_request,
1306 	    &client->iev);
1307 	gotd_imsg_event_add(&client->iev);
1308 
1309 	evtimer_set(&client->tmo, gotd_request_timeout, client);
1310 
1311 	add_client(client);
1312 	log_debug("%s: new client uid %d connected on fd %d", __func__,
1313 	    client->euid, client->fd);
1314 	return;
1315 err:
1316 	inflight--;
1317 	if (s != -1)
1318 		close(s);
1319 	free(client);
1320 }
1321 
1322 static void
1323 gotd_accept_paused(int fd, short event, void *arg)
1324 {
1325 	event_add(&gotd.ev, NULL);
1326 }
1327 
1328 static const char *gotd_proc_names[PROC_MAX] = {
1329 	"parent",
1330 	"repo_read",
1331 	"repo_write"
1332 };
1333 
1334 static struct gotd_child_proc *
1335 get_proc_for_pid(pid_t pid)
1336 {
1337 	struct gotd_child_proc *proc;
1338 	int i;
1339 
1340 	for (i = 0; i < gotd.nprocs; i++) {
1341 		proc = &gotd.procs[i];
1342 		if (proc->pid == pid)
1343 			return proc;
1344 	}
1345 
1346 	return NULL;
1347 }
1348 
1349 static void
1350 kill_proc(struct gotd_child_proc *proc, int fatal)
1351 {
1352 	if (fatal) {
1353 		log_warnx("sending SIGKILL to PID %d", proc->pid);
1354 		kill(proc->pid, SIGKILL);
1355 	} else
1356 		kill(proc->pid, SIGTERM);
1357 }
1358 
1359 static void
1360 gotd_shutdown(void)
1361 {
1362 	pid_t	 pid;
1363 	int	 status, i;
1364 	struct gotd_child_proc *proc;
1365 
1366 	for (i = 0; i < gotd.nprocs; i++) {
1367 		proc = &gotd.procs[i];
1368 		msgbuf_clear(&proc->iev.ibuf.w);
1369 		close(proc->iev.ibuf.fd);
1370 		kill_proc(proc, 0);
1371 	}
1372 
1373 	log_debug("waiting for children to terminate");
1374 	do {
1375 		pid = wait(&status);
1376 		if (pid == -1) {
1377 			if (errno != EINTR && errno != ECHILD)
1378 				fatal("wait");
1379 		} else if (WIFSIGNALED(status)) {
1380 			proc = get_proc_for_pid(pid);
1381 			log_warnx("%s %s child process terminated; signal %d",
1382 			    proc ? gotd_proc_names[proc->type] : "",
1383 			    proc ? proc->chroot_path : "", WTERMSIG(status));
1384 		}	
1385 	} while (pid != -1 || (pid == -1 && errno == EINTR));
1386 
1387 	log_info("terminating");
1388 	exit(0);
1389 }
1390 
1391 void
1392 gotd_sighdlr(int sig, short event, void *arg)
1393 {
1394 	/*
1395 	 * Normal signal handler rules don't apply because libevent
1396 	 * decouples for us.
1397 	 */
1398 
1399 	switch (sig) {
1400 	case SIGHUP:
1401 		log_info("%s: ignoring SIGHUP", __func__);
1402 		break;
1403 	case SIGUSR1:
1404 		log_info("%s: ignoring SIGUSR1", __func__);
1405 		break;
1406 	case SIGTERM:
1407 	case SIGINT:
1408 		gotd_shutdown();
1409 		log_warnx("gotd terminating");
1410 		exit(0);
1411 		break;
1412 	default:
1413 		fatalx("unexpected signal");
1414 	}
1415 }
1416 
1417 static const struct got_error *
1418 ensure_proc_is_reading(struct gotd_client *client,
1419     struct gotd_child_proc *proc)
1420 {
1421 	if (!client_is_reading(client)) {
1422 		kill_proc(proc, 1);
1423 		return got_error_fmt(GOT_ERR_BAD_PACKET,
1424 		    "PID %d handled a read-request for uid %d but this "
1425 		    "user is not reading from a repository", proc->pid,
1426 		    client->euid);
1427 	}
1428 
1429 	return NULL;
1430 }
1431 
1432 static const struct got_error *
1433 ensure_proc_is_writing(struct gotd_client *client,
1434     struct gotd_child_proc *proc)
1435 {
1436 	if (!client_is_writing(client)) {
1437 		kill_proc(proc, 1);
1438 		return got_error_fmt(GOT_ERR_BAD_PACKET,
1439 		    "PID %d handled a write-request for uid %d but this "
1440 		    "user is not writing to a repository", proc->pid,
1441 		    client->euid);
1442 	}
1443 
1444 	return NULL;
1445 }
1446 
1447 static int
1448 verify_imsg_src(struct gotd_client *client, struct gotd_child_proc *proc,
1449     struct imsg *imsg)
1450 {
1451 	const struct got_error *err;
1452 	struct gotd_child_proc *client_proc;
1453 	int ret = 0;
1454 
1455 	client_proc = get_client_proc(client);
1456 	if (client_proc == NULL)
1457 		fatalx("no process found for uid %d", client->euid);
1458 
1459 	if (proc->pid != client_proc->pid) {
1460 		kill_proc(proc, 1);
1461 		log_warnx("received message from PID %d for uid %d, while "
1462 		    "PID %d is the process serving this user",
1463 		    proc->pid, client->euid, client_proc->pid);
1464 		return 0;
1465 	}
1466 
1467 	switch (imsg->hdr.type) {
1468 	case GOTD_IMSG_ERROR:
1469 		ret = 1;
1470 		break;
1471 	case GOTD_IMSG_PACKFILE_DONE:
1472 		err = ensure_proc_is_reading(client, proc);
1473 		if (err)
1474 			log_warnx("uid %d: %s", client->euid, err->msg);
1475 		else
1476 			ret = 1;
1477 		break;
1478 	case GOTD_IMSG_PACKFILE_INSTALL:
1479 	case GOTD_IMSG_REF_UPDATES_START:
1480 	case GOTD_IMSG_REF_UPDATE:
1481 		err = ensure_proc_is_writing(client, proc);
1482 		if (err)
1483 			log_warnx("uid %d: %s", client->euid, err->msg);
1484 		else
1485 			ret = 1;
1486 		break;
1487 	default:
1488 		log_debug("%s: unexpected imsg %d", __func__, imsg->hdr.type);
1489 		break;
1490 	}
1491 
1492 	return ret;
1493 }
1494 
1495 static const struct got_error *
1496 recv_packfile_done(uint32_t *client_id, struct imsg *imsg)
1497 {
1498 	struct gotd_imsg_packfile_done idone;
1499 	size_t datalen;
1500 
1501 	log_debug("packfile-done received");
1502 
1503 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1504 	if (datalen != sizeof(idone))
1505 		return got_error(GOT_ERR_PRIVSEP_LEN);
1506 	memcpy(&idone, imsg->data, sizeof(idone));
1507 
1508 	*client_id = idone.client_id;
1509 	return NULL;
1510 }
1511 
1512 static const struct got_error *
1513 recv_packfile_install(uint32_t *client_id, struct imsg *imsg)
1514 {
1515 	struct gotd_imsg_packfile_install inst;
1516 	size_t datalen;
1517 
1518 	log_debug("packfile-install received");
1519 
1520 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1521 	if (datalen != sizeof(inst))
1522 		return got_error(GOT_ERR_PRIVSEP_LEN);
1523 	memcpy(&inst, imsg->data, sizeof(inst));
1524 
1525 	*client_id = inst.client_id;
1526 	return NULL;
1527 }
1528 
1529 static const struct got_error *
1530 recv_ref_updates_start(uint32_t *client_id, struct imsg *imsg)
1531 {
1532 	struct gotd_imsg_ref_updates_start istart;
1533 	size_t datalen;
1534 
1535 	log_debug("ref-updates-start received");
1536 
1537 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1538 	if (datalen != sizeof(istart))
1539 		return got_error(GOT_ERR_PRIVSEP_LEN);
1540 	memcpy(&istart, imsg->data, sizeof(istart));
1541 
1542 	*client_id = istart.client_id;
1543 	return NULL;
1544 }
1545 
1546 static const struct got_error *
1547 recv_ref_update(uint32_t *client_id, struct imsg *imsg)
1548 {
1549 	struct gotd_imsg_ref_update iref;
1550 	size_t datalen;
1551 
1552 	log_debug("ref-update received");
1553 
1554 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1555 	if (datalen < sizeof(iref))
1556 		return got_error(GOT_ERR_PRIVSEP_LEN);
1557 	memcpy(&iref, imsg->data, sizeof(iref));
1558 
1559 	*client_id = iref.client_id;
1560 	return NULL;
1561 }
1562 
1563 static const struct got_error *
1564 send_ref_update_ok(struct gotd_client *client,
1565     struct gotd_imsg_ref_update *iref, const char *refname)
1566 {
1567 	struct gotd_imsg_ref_update_ok iok;
1568 	struct ibuf *wbuf;
1569 	size_t len;
1570 
1571 	memset(&iok, 0, sizeof(iok));
1572 	iok.client_id = client->id;
1573 	memcpy(iok.old_id, iref->old_id, SHA1_DIGEST_LENGTH);
1574 	memcpy(iok.new_id, iref->new_id, SHA1_DIGEST_LENGTH);
1575 	iok.name_len = strlen(refname);
1576 
1577 	len = sizeof(iok) + iok.name_len;
1578 	wbuf = imsg_create(&client->iev.ibuf, GOTD_IMSG_REF_UPDATE_OK,
1579 	    PROC_GOTD, gotd.pid, len);
1580 	if (wbuf == NULL)
1581 		return got_error_from_errno("imsg_create REF_UPDATE_OK");
1582 
1583 	if (imsg_add(wbuf, &iok, sizeof(iok)) == -1)
1584 		return got_error_from_errno("imsg_add REF_UPDATE_OK");
1585 	if (imsg_add(wbuf, refname, iok.name_len) == -1)
1586 		return got_error_from_errno("imsg_add REF_UPDATE_OK");
1587 
1588 	wbuf->fd = -1;
1589 	imsg_close(&client->iev.ibuf, wbuf);
1590 	gotd_imsg_event_add(&client->iev);
1591 	return NULL;
1592 }
1593 
1594 static void
1595 send_refs_updated(struct gotd_client *client)
1596 {
1597 	if (gotd_imsg_compose_event(&client->iev,
1598 	    GOTD_IMSG_REFS_UPDATED, PROC_GOTD, -1, NULL, 0) == -1)
1599 		log_warn("imsg compose REFS_UPDATED");
1600 }
1601 
1602 static const struct got_error *
1603 send_ref_update_ng(struct gotd_client *client,
1604     struct gotd_imsg_ref_update *iref, const char *refname,
1605     const char *reason)
1606 {
1607 	const struct got_error *ng_err;
1608 	struct gotd_imsg_ref_update_ng ing;
1609 	struct ibuf *wbuf;
1610 	size_t len;
1611 
1612 	memset(&ing, 0, sizeof(ing));
1613 	ing.client_id = client->id;
1614 	memcpy(ing.old_id, iref->old_id, SHA1_DIGEST_LENGTH);
1615 	memcpy(ing.new_id, iref->new_id, SHA1_DIGEST_LENGTH);
1616 	ing.name_len = strlen(refname);
1617 
1618 	ng_err = got_error_fmt(GOT_ERR_REF_BUSY, "%s", reason);
1619 	ing.reason_len = strlen(ng_err->msg);
1620 
1621 	len = sizeof(ing) + ing.name_len + ing.reason_len;
1622 	wbuf = imsg_create(&client->iev.ibuf, GOTD_IMSG_REF_UPDATE_NG,
1623 	    PROC_GOTD, gotd.pid, len);
1624 	if (wbuf == NULL)
1625 		return got_error_from_errno("imsg_create REF_UPDATE_NG");
1626 
1627 	if (imsg_add(wbuf, &ing, sizeof(ing)) == -1)
1628 		return got_error_from_errno("imsg_add REF_UPDATE_NG");
1629 	if (imsg_add(wbuf, refname, ing.name_len) == -1)
1630 		return got_error_from_errno("imsg_add REF_UPDATE_NG");
1631 	if (imsg_add(wbuf, ng_err->msg, ing.reason_len) == -1)
1632 		return got_error_from_errno("imsg_add REF_UPDATE_NG");
1633 
1634 	wbuf->fd = -1;
1635 	imsg_close(&client->iev.ibuf, wbuf);
1636 	gotd_imsg_event_add(&client->iev);
1637 	return NULL;
1638 }
1639 
1640 static const struct got_error *
1641 install_pack(struct gotd_client *client, const char *repo_path,
1642     struct imsg *imsg)
1643 {
1644 	const struct got_error *err = NULL;
1645 	struct gotd_imsg_packfile_install inst;
1646 	char hex[SHA1_DIGEST_STRING_LENGTH];
1647 	size_t datalen;
1648 	char *packfile_path = NULL, *packidx_path = NULL;
1649 
1650 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1651 	if (datalen != sizeof(inst))
1652 		return got_error(GOT_ERR_PRIVSEP_LEN);
1653 	memcpy(&inst, imsg->data, sizeof(inst));
1654 
1655 	if (client->packfile_path == NULL)
1656 		return got_error_msg(GOT_ERR_BAD_REQUEST,
1657 		    "client has no pack file");
1658 	if (client->packidx_path == NULL)
1659 		return got_error_msg(GOT_ERR_BAD_REQUEST,
1660 		    "client has no pack file index");
1661 
1662 	if (got_sha1_digest_to_str(inst.pack_sha1, hex, sizeof(hex)) == NULL)
1663 		return got_error_msg(GOT_ERR_NO_SPACE,
1664 		    "could not convert pack file SHA1 to hex");
1665 
1666 	if (asprintf(&packfile_path, "/%s/%s/pack-%s.pack",
1667 	    repo_path, GOT_OBJECTS_PACK_DIR, hex) == -1) {
1668 		err = got_error_from_errno("asprintf");
1669 		goto done;
1670 	}
1671 
1672 	if (asprintf(&packidx_path, "/%s/%s/pack-%s.idx",
1673 	    repo_path, GOT_OBJECTS_PACK_DIR, hex) == -1) {
1674 		err = got_error_from_errno("asprintf");
1675 		goto done;
1676 	}
1677 
1678 	if (rename(client->packfile_path, packfile_path) == -1) {
1679 		err = got_error_from_errno3("rename", client->packfile_path,
1680 		    packfile_path);
1681 		goto done;
1682 	}
1683 
1684 	free(client->packfile_path);
1685 	client->packfile_path = NULL;
1686 
1687 	if (rename(client->packidx_path, packidx_path) == -1) {
1688 		err = got_error_from_errno3("rename", client->packidx_path,
1689 		    packidx_path);
1690 		goto done;
1691 	}
1692 
1693 	free(client->packidx_path);
1694 	client->packidx_path = NULL;
1695 done:
1696 	free(packfile_path);
1697 	free(packidx_path);
1698 	return err;
1699 }
1700 
1701 static const struct got_error *
1702 begin_ref_updates(struct gotd_client *client, struct imsg *imsg)
1703 {
1704 	struct gotd_imsg_ref_updates_start istart;
1705 	size_t datalen;
1706 
1707 	if (client->nref_updates != -1)
1708 		return got_error(GOT_ERR_PRIVSEP_MSG);
1709 
1710 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1711 	if (datalen != sizeof(istart))
1712 		return got_error(GOT_ERR_PRIVSEP_LEN);
1713 	memcpy(&istart, imsg->data, sizeof(istart));
1714 
1715 	if (istart.nref_updates <= 0)
1716 		return got_error(GOT_ERR_PRIVSEP_MSG);
1717 
1718 	client->nref_updates = istart.nref_updates;
1719 	return NULL;
1720 }
1721 
1722 static const struct got_error *
1723 update_ref(struct gotd_client *client, const char *repo_path,
1724     struct imsg *imsg)
1725 {
1726 	const struct got_error *err = NULL;
1727 	struct got_repository *repo = NULL;
1728 	struct got_reference *ref = NULL;
1729 	struct gotd_imsg_ref_update iref;
1730 	struct got_object_id old_id, new_id;
1731 	struct got_object_id *id = NULL;
1732 	struct got_object *obj = NULL;
1733 	char *refname = NULL;
1734 	size_t datalen;
1735 	int locked = 0;
1736 
1737 	log_debug("update-ref from uid %d", client->euid);
1738 
1739 	if (client->nref_updates <= 0)
1740 		return got_error(GOT_ERR_PRIVSEP_MSG);
1741 
1742 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1743 	if (datalen < sizeof(iref))
1744 		return got_error(GOT_ERR_PRIVSEP_LEN);
1745 	memcpy(&iref, imsg->data, sizeof(iref));
1746 	if (datalen != sizeof(iref) + iref.name_len)
1747 		return got_error(GOT_ERR_PRIVSEP_LEN);
1748 	refname = malloc(iref.name_len + 1);
1749 	if (refname == NULL)
1750 		return got_error_from_errno("malloc");
1751 	memcpy(refname, imsg->data + sizeof(iref), iref.name_len);
1752 	refname[iref.name_len] = '\0';
1753 
1754 	log_debug("updating ref %s for uid %d", refname, client->euid);
1755 
1756 	err = got_repo_open(&repo, repo_path, NULL, NULL);
1757 	if (err)
1758 		goto done;
1759 
1760 	memcpy(old_id.sha1, iref.old_id, SHA1_DIGEST_LENGTH);
1761 	memcpy(new_id.sha1, iref.new_id, SHA1_DIGEST_LENGTH);
1762 	err = got_object_open(&obj, repo, &new_id);
1763 	if (err)
1764 		goto done;
1765 
1766 	if (iref.ref_is_new) {
1767 		err = got_ref_open(&ref, repo, refname, 0);
1768 		if (err) {
1769 			if (err->code != GOT_ERR_NOT_REF)
1770 				goto done;
1771 			err = got_ref_alloc(&ref, refname, &new_id);
1772 			if (err)
1773 				goto done;
1774 			err = got_ref_write(ref, repo); /* will lock/unlock */
1775 			if (err)
1776 				goto done;
1777 		} else {
1778 			err = got_error_fmt(GOT_ERR_REF_BUSY,
1779 			    "%s has been created by someone else "
1780 			    "while transaction was in progress",
1781 			    got_ref_get_name(ref));
1782 			goto done;
1783 		}
1784 	} else {
1785 		err = got_ref_open(&ref, repo, refname, 1 /* lock */);
1786 		if (err)
1787 			goto done;
1788 		locked = 1;
1789 
1790 		err = got_ref_resolve(&id, repo, ref);
1791 		if (err)
1792 			goto done;
1793 
1794 		if (got_object_id_cmp(id, &old_id) != 0) {
1795 			err = got_error_fmt(GOT_ERR_REF_BUSY,
1796 			    "%s has been modified by someone else "
1797 			    "while transaction was in progress",
1798 			    got_ref_get_name(ref));
1799 			goto done;
1800 		}
1801 
1802 		err = got_ref_change_ref(ref, &new_id);
1803 		if (err)
1804 			goto done;
1805 
1806 		err = got_ref_write(ref, repo);
1807 		if (err)
1808 			goto done;
1809 
1810 		free(id);
1811 		id = NULL;
1812 	}
1813 done:
1814 	if (err) {
1815 		if (err->code == GOT_ERR_LOCKFILE_TIMEOUT) {
1816 			err = got_error_fmt(GOT_ERR_LOCKFILE_TIMEOUT,
1817 			    "could not acquire exclusive file lock for %s",
1818 			    refname);
1819 		}
1820 		send_ref_update_ng(client, &iref, refname, err->msg);
1821 	} else
1822 		send_ref_update_ok(client, &iref, refname);
1823 
1824 	if (client->nref_updates > 0) {
1825 		client->nref_updates--;
1826 		if (client->nref_updates == 0)
1827 			send_refs_updated(client);
1828 
1829 	}
1830 	if (locked) {
1831 		const struct got_error *unlock_err;
1832 		unlock_err = got_ref_unlock(ref);
1833 		if (unlock_err && err == NULL)
1834 			err = unlock_err;
1835 	}
1836 	if (ref)
1837 		got_ref_close(ref);
1838 	if (obj)
1839 		got_object_close(obj);
1840 	if (repo)
1841 		got_repo_close(repo);
1842 	free(refname);
1843 	free(id);
1844 	return err;
1845 }
1846 
1847 static void
1848 gotd_dispatch(int fd, short event, void *arg)
1849 {
1850 	struct gotd_imsgev *iev = arg;
1851 	struct imsgbuf *ibuf = &iev->ibuf;
1852 	struct gotd_child_proc *proc = NULL;
1853 	ssize_t n;
1854 	int shut = 0;
1855 	struct imsg imsg;
1856 
1857 	if (event & EV_READ) {
1858 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1859 			fatal("imsg_read error");
1860 		if (n == 0) {
1861 			/* Connection closed. */
1862 			shut = 1;
1863 			goto done;
1864 		}
1865 	}
1866 
1867 	if (event & EV_WRITE) {
1868 		n = msgbuf_write(&ibuf->w);
1869 		if (n == -1 && errno != EAGAIN)
1870 			fatal("msgbuf_write");
1871 		if (n == 0) {
1872 			/* Connection closed. */
1873 			shut = 1;
1874 			goto done;
1875 		}
1876 	}
1877 
1878 	proc = find_proc_by_fd(fd);
1879 	if (proc == NULL)
1880 		fatalx("cannot find child process for fd %d", fd);
1881 
1882 	for (;;) {
1883 		const struct got_error *err = NULL;
1884 		struct gotd_client *client = NULL;
1885 		uint32_t client_id = 0;
1886 		int do_disconnect = 0;
1887 		int do_ref_updates = 0, do_ref_update = 0;
1888 		int do_packfile_install = 0;
1889 
1890 		if ((n = imsg_get(ibuf, &imsg)) == -1)
1891 			fatal("%s: imsg_get error", __func__);
1892 		if (n == 0)	/* No more messages. */
1893 			break;
1894 
1895 		switch (imsg.hdr.type) {
1896 		case GOTD_IMSG_ERROR:
1897 			do_disconnect = 1;
1898 			err = gotd_imsg_recv_error(&client_id, &imsg);
1899 			break;
1900 		case GOTD_IMSG_PACKFILE_DONE:
1901 			do_disconnect = 1;
1902 			err = recv_packfile_done(&client_id, &imsg);
1903 			break;
1904 		case GOTD_IMSG_PACKFILE_INSTALL:
1905 			err = recv_packfile_install(&client_id, &imsg);
1906 			if (err == NULL)
1907 				do_packfile_install = 1;
1908 			break;
1909 		case GOTD_IMSG_REF_UPDATES_START:
1910 			err = recv_ref_updates_start(&client_id, &imsg);
1911 			if (err == NULL)
1912 				do_ref_updates = 1;
1913 			break;
1914 		case GOTD_IMSG_REF_UPDATE:
1915 			err = recv_ref_update(&client_id, &imsg);
1916 			if (err == NULL)
1917 				do_ref_update = 1;
1918 			break;
1919 		default:
1920 			log_debug("unexpected imsg %d", imsg.hdr.type);
1921 			break;
1922 		}
1923 
1924 		client = find_client(client_id);
1925 		if (client == NULL) {
1926 			log_warnx("%s: client not found", __func__);
1927 			imsg_free(&imsg);
1928 			continue;
1929 		}
1930 
1931 		if (!verify_imsg_src(client, proc, &imsg)) {
1932 			log_debug("dropping imsg type %d from PID %d",
1933 			    imsg.hdr.type, proc->pid);
1934 			imsg_free(&imsg);
1935 			continue;
1936 		}
1937 		if (err)
1938 			log_warnx("uid %d: %s", client->euid, err->msg);
1939 
1940 		if (do_disconnect) {
1941 			if (err)
1942 				disconnect_on_error(client, err);
1943 			else
1944 				disconnect(client);
1945 		} else {
1946 			if (do_packfile_install)
1947 				err = install_pack(client, proc->chroot_path,
1948 				    &imsg);
1949 			else if (do_ref_updates)
1950 				err = begin_ref_updates(client, &imsg);
1951 			else if (do_ref_update)
1952 				err = update_ref(client, proc->chroot_path,
1953 				    &imsg);
1954 			if (err)
1955 				log_warnx("uid %d: %s", client->euid, err->msg);
1956 		}
1957 		imsg_free(&imsg);
1958 	}
1959 done:
1960 	if (!shut) {
1961 		gotd_imsg_event_add(iev);
1962 	} else {
1963 		/* This pipe is dead. Remove its event handler */
1964 		event_del(&iev->ev);
1965 		event_loopexit(NULL);
1966 	}
1967 }
1968 
1969 static pid_t
1970 start_child(enum gotd_procid proc_id, const char *chroot_path,
1971     char *argv0, const char *confpath, int fd, int daemonize, int verbosity)
1972 {
1973 	char	*argv[11];
1974 	int	 argc = 0;
1975 	pid_t	 pid;
1976 
1977 	switch (pid = fork()) {
1978 	case -1:
1979 		fatal("cannot fork");
1980 	case 0:
1981 		break;
1982 	default:
1983 		close(fd);
1984 		return pid;
1985 	}
1986 
1987 	if (fd != GOTD_SOCK_FILENO) {
1988 		if (dup2(fd, GOTD_SOCK_FILENO) == -1)
1989 			fatal("cannot setup imsg fd");
1990 	} else if (fcntl(fd, F_SETFD, 0) == -1)
1991 		fatal("cannot setup imsg fd");
1992 
1993 	argv[argc++] = argv0;
1994 	switch (proc_id) {
1995 	case PROC_REPO_READ:
1996 		argv[argc++] = (char *)"-R";
1997 		break;
1998 	case PROC_REPO_WRITE:
1999 		argv[argc++] = (char *)"-W";
2000 		break;
2001 	default:
2002 		fatalx("invalid process id %d", proc_id);
2003 	}
2004 
2005 	argv[argc++] = (char *)"-f";
2006 	argv[argc++] = (char *)confpath;
2007 
2008 	argv[argc++] = (char *)"-P";
2009 	argv[argc++] = (char *)chroot_path;
2010 
2011 	if (!daemonize)
2012 		argv[argc++] = (char *)"-d";
2013 	if (verbosity > 0)
2014 		argv[argc++] = (char *)"-v";
2015 	if (verbosity > 1)
2016 		argv[argc++] = (char *)"-v";
2017 	argv[argc++] = NULL;
2018 
2019 	execvp(argv0, argv);
2020 	fatal("execvp");
2021 }
2022 
2023 static void
2024 start_repo_children(struct gotd *gotd, char *argv0, const char *confpath,
2025     int daemonize, int verbosity)
2026 {
2027 	struct gotd_repo *repo = NULL;
2028 	struct gotd_child_proc *proc;
2029 	int i;
2030 
2031 	/*
2032 	 * XXX For now, use one reader and one writer per repository.
2033 	 * This should be changed to N readers + M writers.
2034 	 */
2035 	gotd->nprocs = gotd->nrepos * 2;
2036 	gotd->procs = calloc(gotd->nprocs, sizeof(*gotd->procs));
2037 	if (gotd->procs == NULL)
2038 		fatal("calloc");
2039 	for (i = 0; i < gotd->nprocs; i++) {
2040 		if (repo == NULL)
2041 			repo = TAILQ_FIRST(&gotd->repos);
2042 		proc = &gotd->procs[i];
2043 		if (i < gotd->nrepos)
2044 			proc->type = PROC_REPO_READ;
2045 		else
2046 			proc->type = PROC_REPO_WRITE;
2047 		if (strlcpy(proc->repo_name, repo->name,
2048 		    sizeof(proc->repo_name)) >= sizeof(proc->repo_name))
2049 			fatalx("repository name too long: %s", repo->name);
2050 		log_debug("adding repository %s", repo->name);
2051 		if (realpath(repo->path, proc->chroot_path) == NULL)
2052 			fatal("%s", repo->path);
2053 		if (socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK,
2054 		    PF_UNSPEC, proc->pipe) == -1)
2055 			fatal("socketpair");
2056 		proc->pid = start_child(proc->type, proc->chroot_path, argv0,
2057 		    confpath, proc->pipe[1], daemonize, verbosity);
2058 		imsg_init(&proc->iev.ibuf, proc->pipe[0]);
2059 		log_debug("proc %s %s is on fd %d",
2060 		    gotd_proc_names[proc->type], proc->chroot_path,
2061 		    proc->pipe[0]);
2062 		proc->iev.handler = gotd_dispatch;
2063 		proc->iev.events = EV_READ;
2064 		proc->iev.handler_arg = NULL;
2065 		event_set(&proc->iev.ev, proc->iev.ibuf.fd, EV_READ,
2066 		    gotd_dispatch, &proc->iev);
2067 
2068 		repo = TAILQ_NEXT(repo, entry);
2069 	}
2070 }
2071 
2072 static void
2073 apply_unveil(void)
2074 {
2075 	struct gotd_repo *repo;
2076 
2077 	TAILQ_FOREACH(repo, &gotd.repos, entry) {
2078 		if (unveil(repo->path, "rwc") == -1)
2079 			fatal("unveil %s", repo->path);
2080 	}
2081 
2082 	if (unveil(GOT_TMPDIR_STR, "rwc") == -1)
2083 		fatal("unveil %s", GOT_TMPDIR_STR);
2084 
2085 	if (unveil(NULL, NULL) == -1)
2086 		fatal("unveil");
2087 }
2088 
2089 int
2090 main(int argc, char **argv)
2091 {
2092 	const struct got_error *error = NULL;
2093 	int ch, fd = -1, daemonize = 1, verbosity = 0, noaction = 0;
2094 	const char *confpath = GOTD_CONF_PATH;
2095 	char *argv0 = argv[0];
2096 	char title[2048];
2097 	gid_t groups[NGROUPS_MAX];
2098 	int ngroups = NGROUPS_MAX;
2099 	struct passwd *pw = NULL;
2100 	struct group *gr = NULL;
2101 	char *repo_path = NULL;
2102 	enum gotd_procid proc_id = PROC_GOTD;
2103 	struct event evsigint, evsigterm, evsighup, evsigusr1;
2104 	int *pack_fds = NULL, *temp_fds = NULL;
2105 
2106 	log_init(1, LOG_DAEMON); /* Log to stderr until daemonized. */
2107 
2108 	while ((ch = getopt(argc, argv, "df:nP:RvW")) != -1) {
2109 		switch (ch) {
2110 		case 'd':
2111 			daemonize = 0;
2112 			break;
2113 		case 'f':
2114 			confpath = optarg;
2115 			break;
2116 		case 'n':
2117 			noaction = 1;
2118 			break;
2119 		case 'P':
2120 			repo_path = realpath(optarg, NULL);
2121 			if (repo_path == NULL)
2122 				fatal("realpath '%s'", optarg);
2123 			break;
2124 		case 'R':
2125 			proc_id = PROC_REPO_READ;
2126 			break;
2127 		case 'v':
2128 			if (verbosity < 3)
2129 				verbosity++;
2130 			break;
2131 		case 'W':
2132 			proc_id = PROC_REPO_WRITE;
2133 			break;
2134 		default:
2135 			usage();
2136 		}
2137 	}
2138 
2139 	argc -= optind;
2140 	argv += optind;
2141 
2142 	if (argc != 0)
2143 		usage();
2144 
2145 	if (geteuid())
2146 		fatalx("need root privileges");
2147 
2148 	log_init(daemonize ? 0 : 1, LOG_DAEMON);
2149 	log_setverbose(verbosity);
2150 
2151 	if (parse_config(confpath, proc_id, &gotd) != 0)
2152 		return 1;
2153 
2154 	if (proc_id == PROC_GOTD &&
2155 	    (gotd.nrepos == 0 || TAILQ_EMPTY(&gotd.repos)))
2156 		fatalx("no repository defined in configuration file");
2157 
2158 	pw = getpwnam(gotd.user_name);
2159 	if (pw == NULL)
2160 		fatal("getpwuid: user %s not found", gotd.user_name);
2161 
2162 	if (pw->pw_uid == 0) {
2163 		fatalx("cannot run %s as %s: the user running %s "
2164 		    "must not be the superuser",
2165 		    getprogname(), pw->pw_name, getprogname());
2166 	}
2167 
2168 	if (getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups) == -1)
2169 		log_warnx("group membership list truncated");
2170 
2171 	gr = match_group(groups, ngroups, gotd.unix_group_name);
2172 	if (gr == NULL) {
2173 		fatalx("cannot start %s: the user running %s "
2174 		    "must be a secondary member of group %s",
2175 		    getprogname(), getprogname(), gotd.unix_group_name);
2176 	}
2177 	if (gr->gr_gid == pw->pw_gid) {
2178 		fatalx("cannot start %s: the user running %s "
2179 		    "must be a secondary member of group %s, but "
2180 		    "%s is the user's primary group",
2181 		    getprogname(), getprogname(), gotd.unix_group_name,
2182 		    gotd.unix_group_name);
2183 	}
2184 
2185 	if (proc_id == PROC_GOTD &&
2186 	    !got_path_is_absolute(gotd.unix_socket_path))
2187 		fatalx("bad unix socket path \"%s\": must be an absolute path",
2188 		    gotd.unix_socket_path);
2189 
2190 	if (noaction)
2191 		return 0;
2192 
2193 	if (proc_id == PROC_GOTD && verbosity) {
2194 		log_info("socket: %s", gotd.unix_socket_path);
2195 		log_info("user: %s", pw->pw_name);
2196 		log_info("secondary group: %s", gr->gr_name);
2197 
2198 		fd = unix_socket_listen(gotd.unix_socket_path, pw->pw_uid,
2199 		    gr->gr_gid);
2200 		if (fd == -1) {
2201 			fatal("cannot listen on unix socket %s",
2202 			    gotd.unix_socket_path);
2203 		}
2204 	}
2205 
2206 	if (proc_id == PROC_GOTD) {
2207 		gotd.pid = getpid();
2208 		snprintf(title, sizeof(title), "%s", gotd_proc_names[proc_id]);
2209 		start_repo_children(&gotd, argv0, confpath, daemonize,
2210 		    verbosity);
2211 		arc4random_buf(&clients_hash_key, sizeof(clients_hash_key));
2212 		if (daemonize && daemon(0, 0) == -1)
2213 			fatal("daemon");
2214 	} else if (proc_id == PROC_REPO_READ || proc_id == PROC_REPO_WRITE) {
2215 		error = got_repo_pack_fds_open(&pack_fds);
2216 		if (error != NULL)
2217 			fatalx("cannot open pack tempfiles: %s", error->msg);
2218 		error = got_repo_temp_fds_open(&temp_fds);
2219 		if (error != NULL)
2220 			fatalx("cannot open pack tempfiles: %s", error->msg);
2221 		if (repo_path == NULL)
2222 			fatalx("repository path not specified");
2223 		snprintf(title, sizeof(title), "%s %s",
2224 		    gotd_proc_names[proc_id], repo_path);
2225 		if (chroot(repo_path) == -1)
2226 			fatal("chroot");
2227 		if (chdir("/") == -1)
2228 			fatal("chdir(\"/\")");
2229 		if (daemonize && daemon(1, 0) == -1)
2230 			fatal("daemon");
2231 	} else
2232 		fatal("invalid process id %d", proc_id);
2233 
2234 	setproctitle("%s", title);
2235 	log_procinit(title);
2236 
2237 	/* Drop root privileges. */
2238 	if (setgid(pw->pw_gid) == -1)
2239 		fatal("setgid %d failed", pw->pw_gid);
2240 	if (setuid(pw->pw_uid) == -1)
2241 		fatal("setuid %d failed", pw->pw_uid);
2242 
2243 	event_init();
2244 
2245 	switch (proc_id) {
2246 	case PROC_GOTD:
2247 #ifndef PROFILE
2248 		if (pledge("stdio rpath wpath cpath proc getpw sendfd recvfd "
2249 		    "fattr flock unix unveil", NULL) == -1)
2250 			err(1, "pledge");
2251 #endif
2252 		break;
2253 	case PROC_REPO_READ:
2254 #ifndef PROFILE
2255 		if (pledge("stdio rpath recvfd", NULL) == -1)
2256 			err(1, "pledge");
2257 #endif
2258 		repo_read_main(title, pack_fds, temp_fds);
2259 		/* NOTREACHED */
2260 		exit(0);
2261 	case PROC_REPO_WRITE:
2262 #ifndef PROFILE
2263 		if (pledge("stdio rpath recvfd", NULL) == -1)
2264 			err(1, "pledge");
2265 #endif
2266 		repo_write_main(title, pack_fds, temp_fds);
2267 		/* NOTREACHED */
2268 		exit(0);
2269 	default:
2270 		fatal("invalid process id %d", proc_id);
2271 	}
2272 
2273 	if (proc_id != PROC_GOTD)
2274 		fatal("invalid process id %d", proc_id);
2275 
2276 	apply_unveil();
2277 
2278 	signal_set(&evsigint, SIGINT, gotd_sighdlr, NULL);
2279 	signal_set(&evsigterm, SIGTERM, gotd_sighdlr, NULL);
2280 	signal_set(&evsighup, SIGHUP, gotd_sighdlr, NULL);
2281 	signal_set(&evsigusr1, SIGUSR1, gotd_sighdlr, NULL);
2282 	signal(SIGPIPE, SIG_IGN);
2283 
2284 	signal_add(&evsigint, NULL);
2285 	signal_add(&evsigterm, NULL);
2286 	signal_add(&evsighup, NULL);
2287 	signal_add(&evsigusr1, NULL);
2288 
2289 	event_set(&gotd.ev, fd, EV_READ | EV_PERSIST, gotd_accept, NULL);
2290 	if (event_add(&gotd.ev, NULL))
2291 		fatalx("event add");
2292 	evtimer_set(&gotd.pause, gotd_accept_paused, NULL);
2293 
2294 	event_dispatch();
2295 
2296 	if (fd != -1)
2297 		close(fd);
2298 	if (pack_fds)
2299 		got_repo_pack_fds_close(pack_fds);
2300 	free(repo_path);
2301 	return 0;
2302 }