1 /*
2  * Copyright (c) 2022 Stefan Sperling <stsp@openbsd.org>
3  * Copyright (c) 2015 Ted Unangst <tedu@openbsd.org>
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 #include <sys/queue.h>
19 #include <sys/tree.h>
20 #include <sys/time.h>
21 #include <sys/types.h>
22 #include <sys/stat.h>
23 #include <sys/socket.h>
24 #include <sys/un.h>
25 #include <sys/wait.h>
26 
27 #include <fcntl.h>
28 #include <err.h>
29 #include <errno.h>
30 #include <event.h>
31 #include <limits.h>
32 #include <pwd.h>
33 #include <grp.h>
34 #include <imsg.h>
35 #include <sha1.h>
36 #include <signal.h>
37 #include <siphash.h>
38 #include <stdarg.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <syslog.h>
43 #include <unistd.h>
44 
45 #include "got_error.h"
46 #include "got_opentemp.h"
47 #include "got_path.h"
48 #include "got_repository.h"
49 #include "got_object.h"
50 #include "got_reference.h"
51 
52 #include "got_lib_delta.h"
53 #include "got_lib_object.h"
54 #include "got_lib_object_cache.h"
55 #include "got_lib_sha1.h"
56 #include "got_lib_gitproto.h"
57 #include "got_lib_pack.h"
58 #include "got_lib_repository.h"
59 
60 #include "gotd.h"
61 #include "log.h"
62 #include "auth.h"
63 #include "repo_read.h"
64 #include "repo_write.h"
65 
66 #ifndef nitems
67 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
68 #endif
69 
70 struct gotd_client {
71 	STAILQ_ENTRY(gotd_client)	 entry;
72 	enum gotd_client_state		 state;
73 	struct gotd_client_capability	*capabilities;
74 	size_t				 ncapa_alloc;
75 	size_t				 ncapabilities;
76 	uint32_t			 id;
77 	int				 fd;
78 	int				 delta_cache_fd;
79 	struct gotd_imsgev		 iev;
80 	struct event			 tmo;
81 	uid_t				 euid;
82 	gid_t				 egid;
83 	struct gotd_child_proc		*repo_read;
84 	struct gotd_child_proc		*repo_write;
85 	char				*packfile_path;
86 	char				*packidx_path;
87 	int				 nref_updates;
88 };
89 STAILQ_HEAD(gotd_clients, gotd_client);
90 
91 static struct gotd_clients gotd_clients[GOTD_CLIENT_TABLE_SIZE];
92 static SIPHASH_KEY clients_hash_key;
93 volatile int client_cnt;
94 static struct timeval timeout = { 3600, 0 };
95 static int inflight;
96 static struct gotd gotd;
97 
98 void gotd_sighdlr(int sig, short event, void *arg);
99 static void gotd_shutdown(void);
100 
101 __dead static void
102 usage()
103 {
104 	fprintf(stderr, "usage: %s [-dv] [-f config-file]\n", getprogname());
105 	exit(1);
106 }
107 
108 static int
109 unix_socket_listen(const char *unix_socket_path, uid_t uid, gid_t gid)
110 {
111 	struct sockaddr_un sun;
112 	int fd = -1;
113 	mode_t old_umask, mode;
114 
115 	fd = socket(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK| SOCK_CLOEXEC, 0);
116 	if (fd == -1) {
117 		log_warn("socket");
118 		return -1;
119 	}
120 
121 	sun.sun_family = AF_UNIX;
122 	if (strlcpy(sun.sun_path, unix_socket_path,
123 	    sizeof(sun.sun_path)) >= sizeof(sun.sun_path)) {
124 		log_warnx("%s: name too long", unix_socket_path);
125 		close(fd);
126 		return -1;
127 	}
128 
129 	if (unlink(unix_socket_path) == -1) {
130 		if (errno != ENOENT) {
131 			log_warn("unlink %s", unix_socket_path);
132 			close(fd);
133 			return -1;
134 		}
135 	}
136 
137 	old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);
138 	mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP;
139 
140 	if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
141 		log_warn("bind: %s", unix_socket_path);
142 		close(fd);
143 		umask(old_umask);
144 		return -1;
145 	}
146 
147 	umask(old_umask);
148 
149 	if (chmod(unix_socket_path, mode) == -1) {
150 		log_warn("chmod %o %s", mode, unix_socket_path);
151 		close(fd);
152 		unlink(unix_socket_path);
153 		return -1;
154 	}
155 
156 	if (chown(unix_socket_path, uid, gid) == -1) {
157 		log_warn("chown %s uid=%d gid=%d", unix_socket_path, uid, gid);
158 		close(fd);
159 		unlink(unix_socket_path);
160 		return -1;
161 	}
162 
163 	if (listen(fd, GOTD_UNIX_SOCKET_BACKLOG) == -1) {
164 		log_warn("listen");
165 		close(fd);
166 		unlink(unix_socket_path);
167 		return -1;
168 	}
169 
170 	return fd;
171 }
172 
173 static struct group *
174 match_group(gid_t *groups, int ngroups, const char *unix_group_name)
175 {
176 	struct group *gr;
177 	int i;
178 
179 	for (i = 0; i < ngroups; i++) {
180 		gr = getgrgid(groups[i]);
181 		if (gr == NULL) {
182 			log_warn("getgrgid %d", groups[i]);
183 			continue;
184 		}
185 		if (strcmp(gr->gr_name, unix_group_name) == 0)
186 			return gr;
187 	}
188 
189 	return NULL;
190 }
191 
192 static int
193 accept_reserve(int fd, struct sockaddr *addr, socklen_t *addrlen,
194     int reserve, volatile int *counter)
195 {
196 	int ret;
197 
198 	if (getdtablecount() + reserve +
199 	    ((*counter + 1) * GOTD_FD_NEEDED) >= getdtablesize()) {
200 		log_debug("inflight fds exceeded");
201 		errno = EMFILE;
202 		return -1;
203 	}
204 
205 	if ((ret = accept4(fd, addr, addrlen,
206 	    SOCK_NONBLOCK | SOCK_CLOEXEC)) > -1) {
207 		(*counter)++;
208 	}
209 
210 	return ret;
211 }
212 
213 static uint64_t
214 client_hash(uint32_t client_id)
215 {
216 	return SipHash24(&clients_hash_key, &client_id, sizeof(client_id));
217 }
218 
219 static void
220 add_client(struct gotd_client *client)
221 {
222 	uint64_t slot = client_hash(client->id) % nitems(gotd_clients);
223 	STAILQ_INSERT_HEAD(&gotd_clients[slot], client, entry);
224 	client_cnt++;
225 }
226 
227 static struct gotd_client *
228 find_client(uint32_t client_id)
229 {
230 	uint64_t slot;
231 	struct gotd_client *c;
232 
233 	slot = client_hash(client_id) % nitems(gotd_clients);
234 	STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
235 		if (c->id == client_id)
236 			return c;
237 	}
238 
239 	return NULL;
240 }
241 
242 static uint32_t
243 get_client_id(void)
244 {
245 	int duplicate = 0;
246 	uint32_t id;
247 
248 	do {
249 		id = arc4random();
250 		duplicate = (find_client(id) != NULL);
251 	} while (duplicate || id == 0);
252 
253 	return id;
254 }
255 
256 static struct gotd_child_proc *
257 get_client_proc(struct gotd_client *client)
258 {
259 	if (client->repo_read && client->repo_write) {
260 		fatalx("uid %d is reading and writing in the same session",
261 		    client->euid);
262 		/* NOTREACHED */
263 	}
264 
265 	if (client->repo_read)
266 		return client->repo_read;
267 	else if (client->repo_write)
268 		return client->repo_write;
269 
270 	return NULL;
271 }
272 
273 static int
274 client_is_reading(struct gotd_client *client)
275 {
276 	return client->repo_read != NULL;
277 }
278 
279 static int
280 client_is_writing(struct gotd_client *client)
281 {
282 	return client->repo_write != NULL;
283 }
284 
285 static const struct got_error *
286 ensure_client_is_reading(struct gotd_client *client)
287 {
288 	if (!client_is_reading(client)) {
289 		return got_error_fmt(GOT_ERR_BAD_PACKET,
290 		    "uid %d made a read-request but is not reading from "
291 		    "a repository", client->euid);
292 	}
293 
294 	return NULL;
295 }
296 
297 static const struct got_error *
298 ensure_client_is_writing(struct gotd_client *client)
299 {
300 	if (!client_is_writing(client)) {
301 		return got_error_fmt(GOT_ERR_BAD_PACKET,
302 		    "uid %d made a write-request but is not writing to "
303 		    "a repository", client->euid);
304 	}
305 
306 	return NULL;
307 }
308 
309 static const struct got_error *
310 ensure_client_is_not_writing(struct gotd_client *client)
311 {
312 	if (client_is_writing(client)) {
313 		return got_error_fmt(GOT_ERR_BAD_PACKET,
314 		    "uid %d made a read-request but is writing to "
315 		    "a repository", client->euid);
316 	}
317 
318 	return NULL;
319 }
320 
321 static const struct got_error *
322 ensure_client_is_not_reading(struct gotd_client *client)
323 {
324 	if (client_is_reading(client)) {
325 		return got_error_fmt(GOT_ERR_BAD_PACKET,
326 		    "uid %d made a write-request but is reading from "
327 		    "a repository", client->euid);
328 	}
329 
330 	return NULL;
331 }
332 
333 static void
334 disconnect(struct gotd_client *client)
335 {
336 	struct gotd_imsg_disconnect idisconnect;
337 	struct gotd_child_proc *proc = get_client_proc(client);
338 	uint64_t slot;
339 
340 	log_debug("uid %d: disconnecting", client->euid);
341 
342 	idisconnect.client_id = client->id;
343 	if (proc) {
344 		if (gotd_imsg_compose_event(&proc->iev,
345 		    GOTD_IMSG_DISCONNECT, PROC_GOTD, -1,
346 		    &idisconnect, sizeof(idisconnect)) == -1)
347 			log_warn("imsg compose DISCONNECT");
348 	}
349 	slot = client_hash(client->id) % nitems(gotd_clients);
350 	STAILQ_REMOVE(&gotd_clients[slot], client, gotd_client, entry);
351 	imsg_clear(&client->iev.ibuf);
352 	event_del(&client->iev.ev);
353 	evtimer_del(&client->tmo);
354 	close(client->fd);
355 	if (client->delta_cache_fd != -1)
356 		close(client->delta_cache_fd);
357 	if (client->packfile_path) {
358 		if (unlink(client->packfile_path) == -1 && errno != ENOENT)
359 			log_warn("unlink %s: ", client->packfile_path);
360 		free(client->packfile_path);
361 	}
362 	if (client->packidx_path) {
363 		if (unlink(client->packidx_path) == -1 && errno != ENOENT)
364 			log_warn("unlink %s: ", client->packidx_path);
365 		free(client->packidx_path);
366 	}
367 	free(client->capabilities);
368 	free(client);
369 	inflight--;
370 	client_cnt--;
371 }
372 
373 static void
374 disconnect_on_error(struct gotd_client *client, const struct got_error *err)
375 {
376 	struct imsgbuf ibuf;
377 
378 	log_warnx("uid %d: %s", client->euid, err->msg);
379 	if (err->code != GOT_ERR_EOF) {
380 		imsg_init(&ibuf, client->fd);
381 		gotd_imsg_send_error(&ibuf, 0, PROC_GOTD, err);
382 		imsg_clear(&ibuf);
383 	}
384 	disconnect(client);
385 }
386 
387 static const struct got_error *
388 send_repo_info(struct gotd_imsgev *iev, struct gotd_repo *repo)
389 {
390 	const struct got_error *err = NULL;
391 	struct gotd_imsg_info_repo irepo;
392 
393 	memset(&irepo, 0, sizeof(irepo));
394 
395 	if (strlcpy(irepo.repo_name, repo->name, sizeof(irepo.repo_name))
396 	    >= sizeof(irepo.repo_name))
397 		return got_error_msg(GOT_ERR_NO_SPACE, "repo name too long");
398 	if (strlcpy(irepo.repo_path, repo->path, sizeof(irepo.repo_path))
399 	    >= sizeof(irepo.repo_path))
400 		return got_error_msg(GOT_ERR_NO_SPACE, "repo path too long");
401 
402 	if (gotd_imsg_compose_event(iev, GOTD_IMSG_INFO_REPO, PROC_GOTD, -1,
403 	    &irepo, sizeof(irepo)) == -1) {
404 		err = got_error_from_errno("imsg compose INFO_REPO");
405 		if (err)
406 			return err;
407 	}
408 
409 	return NULL;
410 }
411 
412 static const struct got_error *
413 send_capability(struct gotd_client_capability *capa, struct gotd_imsgev* iev)
414 {
415 	const struct got_error *err = NULL;
416 	struct gotd_imsg_capability icapa;
417 	size_t len;
418 	struct ibuf *wbuf;
419 
420 	memset(&icapa, 0, sizeof(icapa));
421 
422 	icapa.key_len = strlen(capa->key);
423 	len = sizeof(icapa) + icapa.key_len;
424 	if (capa->value) {
425 		icapa.value_len = strlen(capa->value);
426 		len += icapa.value_len;
427 	}
428 
429 	wbuf = imsg_create(&iev->ibuf, GOTD_IMSG_CAPABILITY, 0, 0, len);
430 	if (wbuf == NULL) {
431 		err = got_error_from_errno("imsg_create CAPABILITY");
432 		return err;
433 	}
434 
435 	if (imsg_add(wbuf, &icapa, sizeof(icapa)) == -1)
436 		return got_error_from_errno("imsg_add CAPABILITY");
437 	if (imsg_add(wbuf, capa->key, icapa.key_len) == -1)
438 		return got_error_from_errno("imsg_add CAPABILITY");
439 	if (capa->value) {
440 		if (imsg_add(wbuf, capa->value, icapa.value_len) == -1)
441 			return got_error_from_errno("imsg_add CAPABILITY");
442 	}
443 
444 	wbuf->fd = -1;
445 	imsg_close(&iev->ibuf, wbuf);
446 
447 	gotd_imsg_event_add(iev);
448 
449 	return NULL;
450 }
451 
452 static const struct got_error *
453 send_client_info(struct gotd_imsgev *iev, struct gotd_client *client)
454 {
455 	const struct got_error *err = NULL;
456 	struct gotd_imsg_info_client iclient;
457 	struct gotd_child_proc *proc;
458 	size_t i;
459 
460 	memset(&iclient, 0, sizeof(iclient));
461 	iclient.euid = client->euid;
462 	iclient.egid = client->egid;
463 
464 	proc = get_client_proc(client);
465 	if (proc) {
466 		if (strlcpy(iclient.repo_name, proc->chroot_path,
467 		    sizeof(iclient.repo_name)) >= sizeof(iclient.repo_name)) {
468 			return got_error_msg(GOT_ERR_NO_SPACE,
469 			    "repo name too long");
470 		}
471 		if (client_is_writing(client))
472 			iclient.is_writing = 1;
473 	}
474 
475 	iclient.state = client->state;
476 	iclient.ncapabilities = client->ncapabilities;
477 
478 	if (gotd_imsg_compose_event(iev, GOTD_IMSG_INFO_CLIENT, PROC_GOTD, -1,
479 	    &iclient, sizeof(iclient)) == -1) {
480 		err = got_error_from_errno("imsg compose INFO_CLIENT");
481 		if (err)
482 			return err;
483 	}
484 
485 	for (i = 0; i < client->ncapabilities; i++) {
486 		struct gotd_client_capability *capa;
487 		capa = &client->capabilities[i];
488 		err = send_capability(capa, iev);
489 		if (err)
490 			return err;
491 	}
492 
493 	return NULL;
494 }
495 
496 static const struct got_error *
497 send_info(struct gotd_client *client)
498 {
499 	const struct got_error *err = NULL;
500 	struct gotd_imsg_info info;
501 	uint64_t slot;
502 	struct gotd_repo *repo;
503 
504 	info.pid = gotd.pid;
505 	info.verbosity = gotd.verbosity;
506 	info.nrepos = gotd.nrepos;
507 	info.nclients = client_cnt - 1;
508 
509 	if (gotd_imsg_compose_event(&client->iev, GOTD_IMSG_INFO, PROC_GOTD, -1,
510 	    &info, sizeof(info)) == -1) {
511 		err = got_error_from_errno("imsg compose INFO");
512 		if (err)
513 			return err;
514 	}
515 
516 	TAILQ_FOREACH(repo, &gotd.repos, entry) {
517 		err = send_repo_info(&client->iev, repo);
518 		if (err)
519 			return err;
520 	}
521 
522 	for (slot = 0; slot < nitems(gotd_clients); slot++) {
523 		struct gotd_client *c;
524 		STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
525 			if (c->id == client->id)
526 				continue;
527 			err = send_client_info(&client->iev, c);
528 			if (err)
529 				return err;
530 		}
531 	}
532 
533 	return NULL;
534 }
535 
536 static const struct got_error *
537 stop_gotd(struct gotd_client *client)
538 {
539 
540 	if (client->euid != 0)
541 		return got_error_set_errno(EPERM, "stop");
542 
543 	gotd_shutdown();
544 	/* NOTREACHED */
545 	return NULL;
546 }
547 
548 static struct gotd_repo *
549 find_repo_by_name(const char *repo_name)
550 {
551 	struct gotd_repo *repo;
552 	size_t namelen;
553 
554 	TAILQ_FOREACH(repo, &gotd.repos, entry) {
555 		namelen = strlen(repo->name);
556 		if (strncmp(repo->name, repo_name, namelen) != 0)
557 			continue;
558 		if (repo_name[namelen] == '\0' ||
559 		    strcmp(&repo_name[namelen], ".git") == 0)
560 			return repo;
561 	}
562 
563 	return NULL;
564 }
565 
566 static struct gotd_child_proc *
567 find_proc_by_repo_name(enum gotd_procid proc_id, const char *repo_name)
568 {
569 	struct gotd_child_proc *proc;
570 	int i;
571 	size_t namelen;
572 
573 	for (i = 0; i < gotd.nprocs; i++) {
574 		proc = &gotd.procs[i];
575 		if (proc->type != proc_id)
576 			continue;
577 		namelen = strlen(proc->repo_name);
578 		if (strncmp(proc->repo_name, repo_name, namelen) != 0)
579 			continue;
580 		if (repo_name[namelen] == '\0' ||
581 		    strcmp(&repo_name[namelen], ".git") == 0)
582 			return proc;
583 	}
584 
585 	return NULL;
586 }
587 
588 static struct gotd_child_proc *
589 find_proc_by_fd(int fd)
590 {
591 	struct gotd_child_proc *proc;
592 	int i;
593 
594 	for (i = 0; i < gotd.nprocs; i++) {
595 		proc = &gotd.procs[i];
596 		if (proc->iev.ibuf.fd == fd)
597 			return proc;
598 	}
599 
600 	return NULL;
601 }
602 
603 static const struct got_error *
604 forward_list_refs_request(struct gotd_client *client, struct imsg *imsg)
605 {
606 	const struct got_error *err;
607 	struct gotd_imsg_list_refs ireq;
608 	struct gotd_imsg_list_refs_internal ilref;
609 	struct gotd_repo *repo = NULL;
610 	struct gotd_child_proc *proc = NULL;
611 	size_t datalen;
612 	int fd = -1;
613 
614 	log_debug("list-refs request from uid %d", client->euid);
615 
616 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
617 	if (datalen != sizeof(ireq))
618 		return got_error(GOT_ERR_PRIVSEP_LEN);
619 
620 	memcpy(&ireq, imsg->data, datalen);
621 
622 	memset(&ilref, 0, sizeof(ilref));
623 	ilref.client_id = client->id;
624 
625 	if (ireq.client_is_reading) {
626 		err = ensure_client_is_not_writing(client);
627 		if (err)
628 			return err;
629 		repo = find_repo_by_name(ireq.repo_name);
630 		if (repo == NULL)
631 			return got_error(GOT_ERR_NOT_GIT_REPO);
632 		err = gotd_auth_check(&repo->rules, repo->name,
633 		    gotd.groups, gotd.ngroups, client->euid, client->egid,
634 		    GOTD_AUTH_READ);
635 		if (err)
636 			return err;
637 		client->repo_read = find_proc_by_repo_name(PROC_REPO_READ,
638 		    ireq.repo_name);
639 		if (client->repo_read == NULL)
640 			return got_error(GOT_ERR_NOT_GIT_REPO);
641 	} else {
642 		err = ensure_client_is_not_reading(client);
643 		if (err)
644 			return err;
645 		repo = find_repo_by_name(ireq.repo_name);
646 		if (repo == NULL)
647 			return got_error(GOT_ERR_NOT_GIT_REPO);
648 		err = gotd_auth_check(&repo->rules, repo->name,
649 		    gotd.groups, gotd.ngroups, client->euid, client->egid,
650 		    GOTD_AUTH_READ | GOTD_AUTH_WRITE);
651 		if (err)
652 			return err;
653 		client->repo_write = find_proc_by_repo_name(PROC_REPO_WRITE,
654 		    ireq.repo_name);
655 		if (client->repo_write == NULL)
656 			return got_error(GOT_ERR_NOT_GIT_REPO);
657 	}
658 
659 	fd = dup(client->fd);
660 	if (fd == -1)
661 		return got_error_from_errno("dup");
662 
663 	proc = get_client_proc(client);
664 	if (proc == NULL)
665 		fatalx("no process found for uid %d", client->euid);
666 	if (gotd_imsg_compose_event(&proc->iev,
667 	    GOTD_IMSG_LIST_REFS_INTERNAL, PROC_GOTD, fd,
668 	    &ilref, sizeof(ilref)) == -1) {
669 		err = got_error_from_errno("imsg compose WANT");
670 		close(fd);
671 		return err;
672 	}
673 
674 	return NULL;
675 }
676 
677 static const struct got_error *
678 forward_want(struct gotd_client *client, struct imsg *imsg)
679 {
680 	struct gotd_imsg_want ireq;
681 	struct gotd_imsg_want iwant;
682 	size_t datalen;
683 
684 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
685 	if (datalen != sizeof(ireq))
686 		return got_error(GOT_ERR_PRIVSEP_LEN);
687 
688 	memcpy(&ireq, imsg->data, datalen);
689 
690 	memset(&iwant, 0, sizeof(iwant));
691 	memcpy(iwant.object_id, ireq.object_id, SHA1_DIGEST_LENGTH);
692 	iwant.client_id = client->id;
693 
694 	if (gotd_imsg_compose_event(&client->repo_read->iev, GOTD_IMSG_WANT,
695 	    PROC_GOTD, -1, &iwant, sizeof(iwant)) == -1)
696 		return got_error_from_errno("imsg compose WANT");
697 
698 	return NULL;
699 }
700 
701 static const struct got_error *
702 forward_ref_update(struct gotd_client *client, struct imsg *imsg)
703 {
704 	const struct got_error *err = NULL;
705 	struct gotd_imsg_ref_update ireq;
706 	struct gotd_imsg_ref_update *iref = NULL;
707 	size_t datalen;
708 
709 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
710 	if (datalen < sizeof(ireq))
711 		return got_error(GOT_ERR_PRIVSEP_LEN);
712 	memcpy(&ireq, imsg->data, sizeof(ireq));
713 	if (datalen != sizeof(ireq) + ireq.name_len)
714 		return got_error(GOT_ERR_PRIVSEP_LEN);
715 
716 	iref = malloc(datalen);
717 	if (iref == NULL)
718 		return got_error_from_errno("malloc");
719 	memcpy(iref, imsg->data, datalen);
720 
721 	iref->client_id = client->id;
722 	if (gotd_imsg_compose_event(&client->repo_write->iev,
723 	    GOTD_IMSG_REF_UPDATE, PROC_GOTD, -1, iref, datalen) == -1)
724 		err = got_error_from_errno("imsg compose REF_UPDATE");
725 	free(iref);
726 	return err;
727 }
728 
729 static const struct got_error *
730 forward_have(struct gotd_client *client, struct imsg *imsg)
731 {
732 	struct gotd_imsg_have ireq;
733 	struct gotd_imsg_have ihave;
734 	size_t datalen;
735 
736 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
737 	if (datalen != sizeof(ireq))
738 		return got_error(GOT_ERR_PRIVSEP_LEN);
739 
740 	memcpy(&ireq, imsg->data, datalen);
741 
742 	memset(&ihave, 0, sizeof(ihave));
743 	memcpy(ihave.object_id, ireq.object_id, SHA1_DIGEST_LENGTH);
744 	ihave.client_id = client->id;
745 
746 	if (gotd_imsg_compose_event(&client->repo_read->iev, GOTD_IMSG_HAVE,
747 	    PROC_GOTD, -1, &ihave, sizeof(ihave)) == -1)
748 		return got_error_from_errno("imsg compose HAVE");
749 
750 	return NULL;
751 }
752 
753 static int
754 client_has_capability(struct gotd_client *client, const char *capastr)
755 {
756 	struct gotd_client_capability *capa;
757 	size_t i;
758 
759 	if (client->ncapabilities == 0)
760 		return 0;
761 
762 	for (i = 0; i < client->ncapabilities; i++) {
763 		capa = &client->capabilities[i];
764 		if (strcmp(capa->key, capastr) == 0)
765 			return 1;
766 	}
767 
768 	return 0;
769 }
770 
771 static const struct got_error *
772 recv_capabilities(struct gotd_client *client, struct imsg *imsg)
773 {
774 	struct gotd_imsg_capabilities icapas;
775 	size_t datalen;
776 
777 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
778 	if (datalen != sizeof(icapas))
779 		return got_error(GOT_ERR_PRIVSEP_LEN);
780 	memcpy(&icapas, imsg->data, sizeof(icapas));
781 
782 	client->ncapa_alloc = icapas.ncapabilities;
783 	client->capabilities = calloc(client->ncapa_alloc,
784 	    sizeof(*client->capabilities));
785 	if (client->capabilities == NULL) {
786 		client->ncapa_alloc = 0;
787 		return got_error_from_errno("calloc");
788 	}
789 
790 	log_debug("expecting %zu capabilities from uid %d",
791 	    client->ncapa_alloc, client->euid);
792 	return NULL;
793 }
794 
795 static const struct got_error *
796 recv_capability(struct gotd_client *client, struct imsg *imsg)
797 {
798 	struct gotd_imsg_capability icapa;
799 	struct gotd_client_capability *capa;
800 	size_t datalen;
801 	char *key, *value = NULL;
802 
803 	if (client->capabilities == NULL ||
804 	    client->ncapabilities >= client->ncapa_alloc) {
805 		return got_error_msg(GOT_ERR_BAD_REQUEST,
806 		    "unexpected capability received");
807 	}
808 
809 	memset(&icapa, 0, sizeof(icapa));
810 
811 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
812 	if (datalen < sizeof(icapa))
813 		return got_error(GOT_ERR_PRIVSEP_LEN);
814 	memcpy(&icapa, imsg->data, sizeof(icapa));
815 
816 	if (datalen != sizeof(icapa) + icapa.key_len + icapa.value_len)
817 		return got_error(GOT_ERR_PRIVSEP_LEN);
818 
819 	key = malloc(icapa.key_len + 1);
820 	if (key == NULL)
821 		return got_error_from_errno("malloc");
822 	if (icapa.value_len > 0) {
823 		value = malloc(icapa.value_len + 1);
824 		if (value == NULL) {
825 			free(key);
826 			return got_error_from_errno("malloc");
827 		}
828 	}
829 
830 	memcpy(key, imsg->data + sizeof(icapa), icapa.key_len);
831 	key[icapa.key_len] = '\0';
832 	if (value) {
833 		memcpy(value, imsg->data + sizeof(icapa) + icapa.key_len,
834 		    icapa.value_len);
835 		value[icapa.value_len] = '\0';
836 	}
837 
838 	capa = &client->capabilities[client->ncapabilities++];
839 	capa->key = key;
840 	capa->value = value;
841 
842 	if (value)
843 		log_debug("uid %d: capability %s=%s", client->euid, key, value);
844 	else
845 		log_debug("uid %d: capability %s", client->euid, key);
846 
847 	return NULL;
848 }
849 
850 static const struct got_error *
851 send_packfile(struct gotd_client *client)
852 {
853 	const struct got_error *err = NULL;
854 	struct gotd_imsg_send_packfile ipack;
855 	struct gotd_imsg_packfile_pipe ipipe;
856 	int pipe[2];
857 
858 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe) == -1)
859 		return got_error_from_errno("socketpair");
860 
861 	memset(&ipack, 0, sizeof(ipack));
862 	memset(&ipipe, 0, sizeof(ipipe));
863 
864 	ipack.client_id = client->id;
865 	if (client_has_capability(client, GOT_CAPA_SIDE_BAND_64K))
866 		ipack.report_progress = 1;
867 
868 	client->delta_cache_fd = got_opentempfd();
869 	if (client->delta_cache_fd == -1)
870 		return got_error_from_errno("got_opentempfd");
871 
872 	if (gotd_imsg_compose_event(&client->repo_read->iev,
873 	    GOTD_IMSG_SEND_PACKFILE, PROC_GOTD, client->delta_cache_fd,
874 	    &ipack, sizeof(ipack)) == -1) {
875 		err = got_error_from_errno("imsg compose SEND_PACKFILE");
876 		close(pipe[0]);
877 		close(pipe[1]);
878 		return err;
879 	}
880 
881 	ipipe.client_id = client->id;
882 
883 	/* Send pack pipe end 0 to repo_read. */
884 	if (gotd_imsg_compose_event(&client->repo_read->iev,
885 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[0],
886 	        &ipipe, sizeof(ipipe)) == -1) {
887 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
888 		close(pipe[1]);
889 		return err;
890 	}
891 
892 	/* Send pack pipe end 1 to gotsh(1) (expects just an fd, no data). */
893 	if (gotd_imsg_compose_event(&client->iev,
894 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[1], NULL, 0) == -1)
895 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
896 
897 	return err;
898 }
899 
900 static const struct got_error *
901 recv_packfile(struct gotd_client *client)
902 {
903 	const struct got_error *err = NULL;
904 	struct gotd_imsg_recv_packfile ipack;
905 	struct gotd_imsg_packfile_pipe ipipe;
906 	struct gotd_imsg_packidx_file ifile;
907 	char *basepath = NULL, *pack_path = NULL, *idx_path = NULL;
908 	int packfd = -1, idxfd = -1;
909 	int pipe[2] = { -1, -1 };
910 
911 	if (client->packfile_path) {
912 		return got_error_fmt(GOT_ERR_PRIVSEP_MSG,
913 		    "uid %d already has a pack file", client->euid);
914 	}
915 
916 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe) == -1)
917 		return got_error_from_errno("socketpair");
918 
919 	memset(&ipipe, 0, sizeof(ipipe));
920 	ipipe.client_id = client->id;
921 
922 	/* Send pack pipe end 0 to repo_write. */
923 	if (gotd_imsg_compose_event(&client->repo_write->iev,
924 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[0],
925 	        &ipipe, sizeof(ipipe)) == -1) {
926 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
927 		pipe[0] = -1;
928 		goto done;
929 	}
930 	pipe[0] = -1;
931 
932 	/* Send pack pipe end 1 to gotsh(1) (expects just an fd, no data). */
933 	if (gotd_imsg_compose_event(&client->iev,
934 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[1], NULL, 0) == -1)
935 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
936 	pipe[1] = -1;
937 
938 	if (asprintf(&basepath, "%s/%s/receiving-from-uid-%d.pack",
939 	    client->repo_write->chroot_path, GOT_OBJECTS_PACK_DIR,
940 	    client->euid) == -1) {
941 		err = got_error_from_errno("asprintf");
942 		goto done;
943 	}
944 
945 	err = got_opentemp_named_fd(&pack_path, &packfd, basepath, "");
946 	if (err)
947 		goto done;
948 
949 	free(basepath);
950 	if (asprintf(&basepath, "%s/%s/receiving-from-uid-%d.idx",
951 	    client->repo_write->chroot_path, GOT_OBJECTS_PACK_DIR,
952 	    client->euid) == -1) {
953 		err = got_error_from_errno("asprintf");
954 		basepath = NULL;
955 		goto done;
956 	}
957 	err = got_opentemp_named_fd(&idx_path, &idxfd, basepath, "");
958 	if (err)
959 		goto done;
960 
961 	memset(&ifile, 0, sizeof(ifile));
962 	ifile.client_id = client->id;
963 	if (gotd_imsg_compose_event(&client->repo_write->iev,
964 	    GOTD_IMSG_PACKIDX_FILE, PROC_GOTD, idxfd,
965 	    &ifile, sizeof(ifile)) == -1) {
966 		err = got_error_from_errno("imsg compose PACKIDX_FILE");
967 		idxfd = -1;
968 		goto done;
969 	}
970 	idxfd = -1;
971 
972 	memset(&ipack, 0, sizeof(ipack));
973 	ipack.client_id = client->id;
974 	if (client_has_capability(client, GOT_CAPA_REPORT_STATUS))
975 		ipack.report_status = 1;
976 
977 	if (gotd_imsg_compose_event(&client->repo_write->iev,
978 	    GOTD_IMSG_RECV_PACKFILE, PROC_GOTD, packfd,
979 	    &ipack, sizeof(ipack)) == -1) {
980 		err = got_error_from_errno("imsg compose RECV_PACKFILE");
981 		packfd = -1;
982 		goto done;
983 	}
984 	packfd = -1;
985 
986 done:
987 	free(basepath);
988 	if (pipe[0] != -1 && close(pipe[0]) == -1 && err == NULL)
989 		err = got_error_from_errno("close");
990 	if (pipe[1] != -1 && close(pipe[1]) == -1 && err == NULL)
991 		err = got_error_from_errno("close");
992 	if (packfd != -1 && close(packfd) == -1 && err == NULL)
993 		err = got_error_from_errno("close");
994 	if (idxfd != -1 && close(idxfd) == -1 && err == NULL)
995 		err = got_error_from_errno("close");
996 	if (err) {
997 		free(pack_path);
998 		free(idx_path);
999 	} else {
1000 		client->packfile_path = pack_path;
1001 		client->packidx_path = idx_path;
1002 	}
1003 	return err;
1004 }
1005 
1006 static void
1007 gotd_request(int fd, short events, void *arg)
1008 {
1009 	struct gotd_imsgev *iev = arg;
1010 	struct imsgbuf *ibuf = &iev->ibuf;
1011 	struct gotd_client *client = iev->handler_arg;
1012 	const struct got_error *err = NULL;
1013 	struct imsg imsg;
1014 	ssize_t n;
1015 
1016 	if (events & EV_WRITE) {
1017 		while (ibuf->w.queued) {
1018 			n = msgbuf_write(&ibuf->w);
1019 			if (n == -1 && errno == EPIPE) {
1020 				/*
1021 				 * The client has closed its socket.
1022 				 * This can happen when Git clients are
1023 				 * done sending pack file data.
1024 				*/
1025 				msgbuf_clear(&ibuf->w);
1026 				continue;
1027 			} else if (n == -1 && errno != EAGAIN) {
1028 				err = got_error_from_errno("imsg_flush");
1029 				disconnect_on_error(client, err);
1030 				return;
1031 			}
1032 			if (n == 0) {
1033 				/* Connection closed. */
1034 				err = got_error(GOT_ERR_EOF);
1035 				disconnect_on_error(client, err);
1036 				return;
1037 			}
1038 		}
1039 
1040 		/* Disconnect gotctl(8) now that messages have been sent. */
1041 		if (!client_is_reading(client) && !client_is_writing(client)) {
1042 			disconnect(client);
1043 			return;
1044 		}
1045 	}
1046 
1047 	if ((events & EV_READ) == 0)
1048 		return;
1049 
1050 	memset(&imsg, 0, sizeof(imsg));
1051 
1052 	while (err == NULL) {
1053 		err = gotd_imsg_recv(&imsg, ibuf, 0);
1054 		if (err) {
1055 			if (err->code == GOT_ERR_PRIVSEP_READ)
1056 				err = NULL;
1057 			break;
1058 		}
1059 
1060 		evtimer_del(&client->tmo);
1061 
1062 		switch (imsg.hdr.type) {
1063 		case GOTD_IMSG_INFO:
1064 			err = send_info(client);
1065 			break;
1066 		case GOTD_IMSG_STOP:
1067 			err = stop_gotd(client);
1068 			break;
1069 		case GOTD_IMSG_LIST_REFS:
1070 			if (client->state != GOTD_STATE_EXPECT_LIST_REFS) {
1071 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1072 				    "unexpected list-refs request received");
1073 				break;
1074 			}
1075 			err = forward_list_refs_request(client, &imsg);
1076 			if (err)
1077 				break;
1078 			client->state = GOTD_STATE_EXPECT_CAPABILITIES;
1079 			log_debug("uid %d: expecting capabilities",
1080 			    client->euid);
1081 			break;
1082 		case GOTD_IMSG_CAPABILITIES:
1083 			if (client->state != GOTD_STATE_EXPECT_CAPABILITIES) {
1084 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1085 				    "unexpected capabilities received");
1086 				break;
1087 			}
1088 			log_debug("receiving capabilities from uid %d",
1089 			    client->euid);
1090 			err = recv_capabilities(client, &imsg);
1091 			break;
1092 		case GOTD_IMSG_CAPABILITY:
1093 			if (client->state != GOTD_STATE_EXPECT_CAPABILITIES) {
1094 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1095 				    "unexpected capability received");
1096 				break;
1097 			}
1098 			err = recv_capability(client, &imsg);
1099 			if (err || client->ncapabilities < client->ncapa_alloc)
1100 				break;
1101 			if (client_is_reading(client)) {
1102 				client->state = GOTD_STATE_EXPECT_WANT;
1103 				log_debug("uid %d: expecting want-lines",
1104 				    client->euid);
1105 			} else if (client_is_writing(client)) {
1106 				client->state = GOTD_STATE_EXPECT_REF_UPDATE;
1107 				log_debug("uid %d: expecting ref-update-lines",
1108 				    client->euid);
1109 			} else
1110 				fatalx("client %d is both reading and writing",
1111 				    client->euid);
1112 			break;
1113 		case GOTD_IMSG_WANT:
1114 			if (client->state != GOTD_STATE_EXPECT_WANT) {
1115 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1116 				    "unexpected want-line received");
1117 				break;
1118 			}
1119 			log_debug("received want-line from uid %d",
1120 			    client->euid);
1121 			err = ensure_client_is_reading(client);
1122 			if (err)
1123 				break;
1124 			err = forward_want(client, &imsg);
1125 			break;
1126 		case GOTD_IMSG_REF_UPDATE:
1127 			if (client->state != GOTD_STATE_EXPECT_REF_UPDATE) {
1128 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1129 				    "unexpected ref-update-line received");
1130 				break;
1131 			}
1132 			log_debug("received ref-update-line from uid %d",
1133 			    client->euid);
1134 			err = ensure_client_is_writing(client);
1135 			if (err)
1136 				break;
1137 			err = forward_ref_update(client, &imsg);
1138 			if (err)
1139 				break;
1140 			client->state = GOTD_STATE_EXPECT_MORE_REF_UPDATES;
1141 			break;
1142 		case GOTD_IMSG_HAVE:
1143 			if (client->state != GOTD_STATE_EXPECT_HAVE) {
1144 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1145 				    "unexpected have-line received");
1146 				break;
1147 			}
1148 			log_debug("received have-line from uid %d",
1149 			    client->euid);
1150 			err = ensure_client_is_reading(client);
1151 			if (err)
1152 				break;
1153 			err = forward_have(client, &imsg);
1154 			if (err)
1155 				break;
1156 			break;
1157 		case GOTD_IMSG_FLUSH:
1158 			if (client->state == GOTD_STATE_EXPECT_WANT ||
1159 			    client->state == GOTD_STATE_EXPECT_HAVE) {
1160 				err = ensure_client_is_reading(client);
1161 				if (err)
1162 					break;
1163 			} else if (client->state ==
1164 			    GOTD_STATE_EXPECT_MORE_REF_UPDATES) {
1165 				err = ensure_client_is_writing(client);
1166 				if (err)
1167 					break;
1168 			} else {
1169 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1170 				    "unexpected flush-pkt received");
1171 				break;
1172 			}
1173 			log_debug("received flush-pkt from uid %d",
1174 			    client->euid);
1175 			if (client->state == GOTD_STATE_EXPECT_WANT) {
1176 				client->state = GOTD_STATE_EXPECT_HAVE;
1177 				log_debug("uid %d: expecting have-lines",
1178 				    client->euid);
1179 			} else if (client->state == GOTD_STATE_EXPECT_HAVE) {
1180 				client->state = GOTD_STATE_EXPECT_DONE;
1181 				log_debug("uid %d: expecting 'done'",
1182 				    client->euid);
1183 			} else if (client->state ==
1184 			    GOTD_STATE_EXPECT_MORE_REF_UPDATES) {
1185 				client->state = GOTD_STATE_EXPECT_PACKFILE;
1186 				log_debug("uid %d: expecting packfile",
1187 				    client->euid);
1188 				err = recv_packfile(client);
1189 			} else {
1190 				/* should not happen, see above */
1191 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1192 				    "unexpected client state");
1193 				break;
1194 			}
1195 			break;
1196 		case GOTD_IMSG_DONE:
1197 			if (client->state != GOTD_STATE_EXPECT_HAVE &&
1198 			    client->state != GOTD_STATE_EXPECT_DONE) {
1199 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1200 				    "unexpected flush-pkt received");
1201 				break;
1202 			}
1203 			log_debug("received 'done' from uid %d", client->euid);
1204 			err = ensure_client_is_reading(client);
1205 			if (err)
1206 				break;
1207 			client->state = GOTD_STATE_DONE;
1208 			err = send_packfile(client);
1209 			break;
1210 		default:
1211 			err = got_error(GOT_ERR_PRIVSEP_MSG);
1212 			break;
1213 		}
1214 
1215 		imsg_free(&imsg);
1216 	}
1217 
1218 	if (err) {
1219 		if (err->code != GOT_ERR_EOF ||
1220 		    client->state != GOTD_STATE_EXPECT_PACKFILE)
1221 			disconnect_on_error(client, err);
1222 	} else {
1223 		gotd_imsg_event_add(&client->iev);
1224 		evtimer_add(&client->tmo, &timeout);
1225 	}
1226 }
1227 
1228 static void
1229 gotd_request_timeout(int fd, short events, void *arg)
1230 {
1231 	struct gotd_client *client = arg;
1232 
1233 	log_debug("disconnecting uid %d due to timeout", client->euid);
1234 	disconnect(client);
1235 }
1236 
1237 static void
1238 gotd_accept(int fd, short event, void *arg)
1239 {
1240 	struct sockaddr_storage ss;
1241 	struct timeval backoff;
1242 	socklen_t len;
1243 	int s = -1;
1244 	struct gotd_client *client = NULL;
1245 	uid_t euid;
1246 	gid_t egid;
1247 
1248 	backoff.tv_sec = 1;
1249 	backoff.tv_usec = 0;
1250 
1251 	if (event_add(&gotd.ev, NULL) == -1) {
1252 		log_warn("event_add");
1253 		return;
1254 	}
1255 	if (event & EV_TIMEOUT)
1256 		return;
1257 
1258 	len = sizeof(ss);
1259 
1260 	s = accept_reserve(fd, (struct sockaddr *)&ss, &len, GOTD_FD_RESERVE,
1261 	    &inflight);
1262 
1263 	if (s == -1) {
1264 		switch (errno) {
1265 		case EINTR:
1266 		case EWOULDBLOCK:
1267 		case ECONNABORTED:
1268 			return;
1269 		case EMFILE:
1270 		case ENFILE:
1271 			event_del(&gotd.ev);
1272 			evtimer_add(&gotd.pause, &backoff);
1273 			return;
1274 		default:
1275 			log_warn("%s: accept", __func__);
1276 			return;
1277 		}
1278 	}
1279 
1280 	if (client_cnt >= GOTD_MAXCLIENTS)
1281 		goto err;
1282 
1283 	if (getpeereid(s, &euid, &egid) == -1) {
1284 		log_warn("%s: getpeereid", __func__);
1285 		goto err;
1286 	}
1287 
1288 	client = calloc(1, sizeof(*client));
1289 	if (client == NULL) {
1290 		log_warn("%s: calloc", __func__);
1291 		goto err;
1292 	}
1293 
1294 	client->state = GOTD_STATE_EXPECT_LIST_REFS;
1295 	client->id = get_client_id();
1296 	client->fd = s;
1297 	s = -1;
1298 	client->delta_cache_fd = -1;
1299 	client->euid = euid;
1300 	client->egid = egid;
1301 	client->nref_updates = -1;
1302 
1303 	imsg_init(&client->iev.ibuf, client->fd);
1304 	client->iev.handler = gotd_request;
1305 	client->iev.events = EV_READ;
1306 	client->iev.handler_arg = client;
1307 
1308 	event_set(&client->iev.ev, client->fd, EV_READ, gotd_request,
1309 	    &client->iev);
1310 	gotd_imsg_event_add(&client->iev);
1311 
1312 	evtimer_set(&client->tmo, gotd_request_timeout, client);
1313 
1314 	add_client(client);
1315 	log_debug("%s: new client uid %d connected on fd %d", __func__,
1316 	    client->euid, client->fd);
1317 	return;
1318 err:
1319 	inflight--;
1320 	if (s != -1)
1321 		close(s);
1322 	free(client);
1323 }
1324 
1325 static void
1326 gotd_accept_paused(int fd, short event, void *arg)
1327 {
1328 	event_add(&gotd.ev, NULL);
1329 }
1330 
1331 static const char *gotd_proc_names[PROC_MAX] = {
1332 	"parent",
1333 	"repo_read",
1334 	"repo_write"
1335 };
1336 
1337 static struct gotd_child_proc *
1338 get_proc_for_pid(pid_t pid)
1339 {
1340 	struct gotd_child_proc *proc;
1341 	int i;
1342 
1343 	for (i = 0; i < gotd.nprocs; i++) {
1344 		proc = &gotd.procs[i];
1345 		if (proc->pid == pid)
1346 			return proc;
1347 	}
1348 
1349 	return NULL;
1350 }
1351 
1352 static void
1353 kill_proc(struct gotd_child_proc *proc, int fatal)
1354 {
1355 	if (fatal) {
1356 		log_warnx("sending SIGKILL to PID %d", proc->pid);
1357 		kill(proc->pid, SIGKILL);
1358 	} else
1359 		kill(proc->pid, SIGTERM);
1360 }
1361 
1362 static void
1363 gotd_shutdown(void)
1364 {
1365 	pid_t	 pid;
1366 	int	 status, i;
1367 	struct gotd_child_proc *proc;
1368 
1369 	for (i = 0; i < gotd.nprocs; i++) {
1370 		proc = &gotd.procs[i];
1371 		msgbuf_clear(&proc->iev.ibuf.w);
1372 		close(proc->iev.ibuf.fd);
1373 		kill_proc(proc, 0);
1374 	}
1375 
1376 	log_debug("waiting for children to terminate");
1377 	do {
1378 		pid = wait(&status);
1379 		if (pid == -1) {
1380 			if (errno != EINTR && errno != ECHILD)
1381 				fatal("wait");
1382 		} else if (WIFSIGNALED(status)) {
1383 			proc = get_proc_for_pid(pid);
1384 			log_warnx("%s %s child process terminated; signal %d",
1385 			    proc ? gotd_proc_names[proc->type] : "",
1386 			    proc ? proc->chroot_path : "", WTERMSIG(status));
1387 		}	
1388 	} while (pid != -1 || (pid == -1 && errno == EINTR));
1389 
1390 	log_info("terminating");
1391 	exit(0);
1392 }
1393 
1394 void
1395 gotd_sighdlr(int sig, short event, void *arg)
1396 {
1397 	/*
1398 	 * Normal signal handler rules don't apply because libevent
1399 	 * decouples for us.
1400 	 */
1401 
1402 	switch (sig) {
1403 	case SIGHUP:
1404 		log_info("%s: ignoring SIGHUP", __func__);
1405 		break;
1406 	case SIGUSR1:
1407 		log_info("%s: ignoring SIGUSR1", __func__);
1408 		break;
1409 	case SIGTERM:
1410 	case SIGINT:
1411 		gotd_shutdown();
1412 		log_warnx("gotd terminating");
1413 		exit(0);
1414 		break;
1415 	default:
1416 		fatalx("unexpected signal");
1417 	}
1418 }
1419 
1420 static const struct got_error *
1421 ensure_proc_is_reading(struct gotd_client *client,
1422     struct gotd_child_proc *proc)
1423 {
1424 	if (!client_is_reading(client)) {
1425 		kill_proc(proc, 1);
1426 		return got_error_fmt(GOT_ERR_BAD_PACKET,
1427 		    "PID %d handled a read-request for uid %d but this "
1428 		    "user is not reading from a repository", proc->pid,
1429 		    client->euid);
1430 	}
1431 
1432 	return NULL;
1433 }
1434 
1435 static const struct got_error *
1436 ensure_proc_is_writing(struct gotd_client *client,
1437     struct gotd_child_proc *proc)
1438 {
1439 	if (!client_is_writing(client)) {
1440 		kill_proc(proc, 1);
1441 		return got_error_fmt(GOT_ERR_BAD_PACKET,
1442 		    "PID %d handled a write-request for uid %d but this "
1443 		    "user is not writing to a repository", proc->pid,
1444 		    client->euid);
1445 	}
1446 
1447 	return NULL;
1448 }
1449 
1450 static int
1451 verify_imsg_src(struct gotd_client *client, struct gotd_child_proc *proc,
1452     struct imsg *imsg)
1453 {
1454 	const struct got_error *err;
1455 	struct gotd_child_proc *client_proc;
1456 	int ret = 0;
1457 
1458 	client_proc = get_client_proc(client);
1459 	if (client_proc == NULL)
1460 		fatalx("no process found for uid %d", client->euid);
1461 
1462 	if (proc->pid != client_proc->pid) {
1463 		kill_proc(proc, 1);
1464 		log_warnx("received message from PID %d for uid %d, while "
1465 		    "PID %d is the process serving this user",
1466 		    proc->pid, client->euid, client_proc->pid);
1467 		return 0;
1468 	}
1469 
1470 	switch (imsg->hdr.type) {
1471 	case GOTD_IMSG_ERROR:
1472 		ret = 1;
1473 		break;
1474 	case GOTD_IMSG_PACKFILE_DONE:
1475 		err = ensure_proc_is_reading(client, proc);
1476 		if (err)
1477 			log_warnx("uid %d: %s", client->euid, err->msg);
1478 		else
1479 			ret = 1;
1480 		break;
1481 	case GOTD_IMSG_PACKFILE_INSTALL:
1482 	case GOTD_IMSG_REF_UPDATES_START:
1483 	case GOTD_IMSG_REF_UPDATE:
1484 		err = ensure_proc_is_writing(client, proc);
1485 		if (err)
1486 			log_warnx("uid %d: %s", client->euid, err->msg);
1487 		else
1488 			ret = 1;
1489 		break;
1490 	default:
1491 		log_debug("%s: unexpected imsg %d", __func__, imsg->hdr.type);
1492 		break;
1493 	}
1494 
1495 	return ret;
1496 }
1497 
1498 static const struct got_error *
1499 recv_packfile_done(uint32_t *client_id, struct imsg *imsg)
1500 {
1501 	struct gotd_imsg_packfile_done idone;
1502 	size_t datalen;
1503 
1504 	log_debug("packfile-done received");
1505 
1506 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1507 	if (datalen != sizeof(idone))
1508 		return got_error(GOT_ERR_PRIVSEP_LEN);
1509 	memcpy(&idone, imsg->data, sizeof(idone));
1510 
1511 	*client_id = idone.client_id;
1512 	return NULL;
1513 }
1514 
1515 static const struct got_error *
1516 recv_packfile_install(uint32_t *client_id, struct imsg *imsg)
1517 {
1518 	struct gotd_imsg_packfile_install inst;
1519 	size_t datalen;
1520 
1521 	log_debug("packfile-install received");
1522 
1523 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1524 	if (datalen != sizeof(inst))
1525 		return got_error(GOT_ERR_PRIVSEP_LEN);
1526 	memcpy(&inst, imsg->data, sizeof(inst));
1527 
1528 	*client_id = inst.client_id;
1529 	return NULL;
1530 }
1531 
1532 static const struct got_error *
1533 recv_ref_updates_start(uint32_t *client_id, struct imsg *imsg)
1534 {
1535 	struct gotd_imsg_ref_updates_start istart;
1536 	size_t datalen;
1537 
1538 	log_debug("ref-updates-start received");
1539 
1540 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1541 	if (datalen != sizeof(istart))
1542 		return got_error(GOT_ERR_PRIVSEP_LEN);
1543 	memcpy(&istart, imsg->data, sizeof(istart));
1544 
1545 	*client_id = istart.client_id;
1546 	return NULL;
1547 }
1548 
1549 static const struct got_error *
1550 recv_ref_update(uint32_t *client_id, struct imsg *imsg)
1551 {
1552 	struct gotd_imsg_ref_update iref;
1553 	size_t datalen;
1554 
1555 	log_debug("ref-update received");
1556 
1557 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1558 	if (datalen < sizeof(iref))
1559 		return got_error(GOT_ERR_PRIVSEP_LEN);
1560 	memcpy(&iref, imsg->data, sizeof(iref));
1561 
1562 	*client_id = iref.client_id;
1563 	return NULL;
1564 }
1565 
1566 static const struct got_error *
1567 send_ref_update_ok(struct gotd_client *client,
1568     struct gotd_imsg_ref_update *iref, const char *refname)
1569 {
1570 	struct gotd_imsg_ref_update_ok iok;
1571 	struct ibuf *wbuf;
1572 	size_t len;
1573 
1574 	memset(&iok, 0, sizeof(iok));
1575 	iok.client_id = client->id;
1576 	memcpy(iok.old_id, iref->old_id, SHA1_DIGEST_LENGTH);
1577 	memcpy(iok.new_id, iref->new_id, SHA1_DIGEST_LENGTH);
1578 	iok.name_len = strlen(refname);
1579 
1580 	len = sizeof(iok) + iok.name_len;
1581 	wbuf = imsg_create(&client->iev.ibuf, GOTD_IMSG_REF_UPDATE_OK,
1582 	    PROC_GOTD, gotd.pid, len);
1583 	if (wbuf == NULL)
1584 		return got_error_from_errno("imsg_create REF_UPDATE_OK");
1585 
1586 	if (imsg_add(wbuf, &iok, sizeof(iok)) == -1)
1587 		return got_error_from_errno("imsg_add REF_UPDATE_OK");
1588 	if (imsg_add(wbuf, refname, iok.name_len) == -1)
1589 		return got_error_from_errno("imsg_add REF_UPDATE_OK");
1590 
1591 	wbuf->fd = -1;
1592 	imsg_close(&client->iev.ibuf, wbuf);
1593 	gotd_imsg_event_add(&client->iev);
1594 	return NULL;
1595 }
1596 
1597 static void
1598 send_refs_updated(struct gotd_client *client)
1599 {
1600 	if (gotd_imsg_compose_event(&client->iev,
1601 	    GOTD_IMSG_REFS_UPDATED, PROC_GOTD, -1, NULL, 0) == -1)
1602 		log_warn("imsg compose REFS_UPDATED");
1603 }
1604 
1605 static const struct got_error *
1606 send_ref_update_ng(struct gotd_client *client,
1607     struct gotd_imsg_ref_update *iref, const char *refname,
1608     const char *reason)
1609 {
1610 	const struct got_error *ng_err;
1611 	struct gotd_imsg_ref_update_ng ing;
1612 	struct ibuf *wbuf;
1613 	size_t len;
1614 
1615 	memset(&ing, 0, sizeof(ing));
1616 	ing.client_id = client->id;
1617 	memcpy(ing.old_id, iref->old_id, SHA1_DIGEST_LENGTH);
1618 	memcpy(ing.new_id, iref->new_id, SHA1_DIGEST_LENGTH);
1619 	ing.name_len = strlen(refname);
1620 
1621 	ng_err = got_error_fmt(GOT_ERR_REF_BUSY, "%s", reason);
1622 	ing.reason_len = strlen(ng_err->msg);
1623 
1624 	len = sizeof(ing) + ing.name_len + ing.reason_len;
1625 	wbuf = imsg_create(&client->iev.ibuf, GOTD_IMSG_REF_UPDATE_NG,
1626 	    PROC_GOTD, gotd.pid, len);
1627 	if (wbuf == NULL)
1628 		return got_error_from_errno("imsg_create REF_UPDATE_NG");
1629 
1630 	if (imsg_add(wbuf, &ing, sizeof(ing)) == -1)
1631 		return got_error_from_errno("imsg_add REF_UPDATE_NG");
1632 	if (imsg_add(wbuf, refname, ing.name_len) == -1)
1633 		return got_error_from_errno("imsg_add REF_UPDATE_NG");
1634 	if (imsg_add(wbuf, ng_err->msg, ing.reason_len) == -1)
1635 		return got_error_from_errno("imsg_add REF_UPDATE_NG");
1636 
1637 	wbuf->fd = -1;
1638 	imsg_close(&client->iev.ibuf, wbuf);
1639 	gotd_imsg_event_add(&client->iev);
1640 	return NULL;
1641 }
1642 
1643 static const struct got_error *
1644 install_pack(struct gotd_client *client, const char *repo_path,
1645     struct imsg *imsg)
1646 {
1647 	const struct got_error *err = NULL;
1648 	struct gotd_imsg_packfile_install inst;
1649 	char hex[SHA1_DIGEST_STRING_LENGTH];
1650 	size_t datalen;
1651 	char *packfile_path = NULL, *packidx_path = NULL;
1652 
1653 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1654 	if (datalen != sizeof(inst))
1655 		return got_error(GOT_ERR_PRIVSEP_LEN);
1656 	memcpy(&inst, imsg->data, sizeof(inst));
1657 
1658 	if (client->packfile_path == NULL)
1659 		return got_error_msg(GOT_ERR_BAD_REQUEST,
1660 		    "client has no pack file");
1661 	if (client->packidx_path == NULL)
1662 		return got_error_msg(GOT_ERR_BAD_REQUEST,
1663 		    "client has no pack file index");
1664 
1665 	if (got_sha1_digest_to_str(inst.pack_sha1, hex, sizeof(hex)) == NULL)
1666 		return got_error_msg(GOT_ERR_NO_SPACE,
1667 		    "could not convert pack file SHA1 to hex");
1668 
1669 	if (asprintf(&packfile_path, "/%s/%s/pack-%s.pack",
1670 	    repo_path, GOT_OBJECTS_PACK_DIR, hex) == -1) {
1671 		err = got_error_from_errno("asprintf");
1672 		goto done;
1673 	}
1674 
1675 	if (asprintf(&packidx_path, "/%s/%s/pack-%s.idx",
1676 	    repo_path, GOT_OBJECTS_PACK_DIR, hex) == -1) {
1677 		err = got_error_from_errno("asprintf");
1678 		goto done;
1679 	}
1680 
1681 	if (rename(client->packfile_path, packfile_path) == -1) {
1682 		err = got_error_from_errno3("rename", client->packfile_path,
1683 		    packfile_path);
1684 		goto done;
1685 	}
1686 
1687 	free(client->packfile_path);
1688 	client->packfile_path = NULL;
1689 
1690 	if (rename(client->packidx_path, packidx_path) == -1) {
1691 		err = got_error_from_errno3("rename", client->packidx_path,
1692 		    packidx_path);
1693 		goto done;
1694 	}
1695 
1696 	free(client->packidx_path);
1697 	client->packidx_path = NULL;
1698 done:
1699 	free(packfile_path);
1700 	free(packidx_path);
1701 	return err;
1702 }
1703 
1704 static const struct got_error *
1705 begin_ref_updates(struct gotd_client *client, struct imsg *imsg)
1706 {
1707 	struct gotd_imsg_ref_updates_start istart;
1708 	size_t datalen;
1709 
1710 	if (client->nref_updates != -1)
1711 		return got_error(GOT_ERR_PRIVSEP_MSG);
1712 
1713 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1714 	if (datalen != sizeof(istart))
1715 		return got_error(GOT_ERR_PRIVSEP_LEN);
1716 	memcpy(&istart, imsg->data, sizeof(istart));
1717 
1718 	if (istart.nref_updates <= 0)
1719 		return got_error(GOT_ERR_PRIVSEP_MSG);
1720 
1721 	client->nref_updates = istart.nref_updates;
1722 	return NULL;
1723 }
1724 
1725 static const struct got_error *
1726 update_ref(struct gotd_client *client, const char *repo_path,
1727     struct imsg *imsg)
1728 {
1729 	const struct got_error *err = NULL;
1730 	struct got_repository *repo = NULL;
1731 	struct got_reference *ref = NULL;
1732 	struct gotd_imsg_ref_update iref;
1733 	struct got_object_id old_id, new_id;
1734 	struct got_object_id *id = NULL;
1735 	struct got_object *obj = NULL;
1736 	char *refname = NULL;
1737 	size_t datalen;
1738 	int locked = 0;
1739 
1740 	log_debug("update-ref from uid %d", client->euid);
1741 
1742 	if (client->nref_updates <= 0)
1743 		return got_error(GOT_ERR_PRIVSEP_MSG);
1744 
1745 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1746 	if (datalen < sizeof(iref))
1747 		return got_error(GOT_ERR_PRIVSEP_LEN);
1748 	memcpy(&iref, imsg->data, sizeof(iref));
1749 	if (datalen != sizeof(iref) + iref.name_len)
1750 		return got_error(GOT_ERR_PRIVSEP_LEN);
1751 	refname = malloc(iref.name_len + 1);
1752 	if (refname == NULL)
1753 		return got_error_from_errno("malloc");
1754 	memcpy(refname, imsg->data + sizeof(iref), iref.name_len);
1755 	refname[iref.name_len] = '\0';
1756 
1757 	log_debug("updating ref %s for uid %d", refname, client->euid);
1758 
1759 	err = got_repo_open(&repo, repo_path, NULL, NULL);
1760 	if (err)
1761 		goto done;
1762 
1763 	memcpy(old_id.sha1, iref.old_id, SHA1_DIGEST_LENGTH);
1764 	memcpy(new_id.sha1, iref.new_id, SHA1_DIGEST_LENGTH);
1765 	err = got_object_open(&obj, repo, &new_id);
1766 	if (err)
1767 		goto done;
1768 
1769 	if (iref.ref_is_new) {
1770 		err = got_ref_open(&ref, repo, refname, 0);
1771 		if (err) {
1772 			if (err->code != GOT_ERR_NOT_REF)
1773 				goto done;
1774 			err = got_ref_alloc(&ref, refname, &new_id);
1775 			if (err)
1776 				goto done;
1777 			err = got_ref_write(ref, repo); /* will lock/unlock */
1778 			if (err)
1779 				goto done;
1780 		} else {
1781 			err = got_error_fmt(GOT_ERR_REF_BUSY,
1782 			    "%s has been created by someone else "
1783 			    "while transaction was in progress",
1784 			    got_ref_get_name(ref));
1785 			goto done;
1786 		}
1787 	} else {
1788 		err = got_ref_open(&ref, repo, refname, 1 /* lock */);
1789 		if (err)
1790 			goto done;
1791 		locked = 1;
1792 
1793 		err = got_ref_resolve(&id, repo, ref);
1794 		if (err)
1795 			goto done;
1796 
1797 		if (got_object_id_cmp(id, &old_id) != 0) {
1798 			err = got_error_fmt(GOT_ERR_REF_BUSY,
1799 			    "%s has been modified by someone else "
1800 			    "while transaction was in progress",
1801 			    got_ref_get_name(ref));
1802 			goto done;
1803 		}
1804 
1805 		err = got_ref_change_ref(ref, &new_id);
1806 		if (err)
1807 			goto done;
1808 
1809 		err = got_ref_write(ref, repo);
1810 		if (err)
1811 			goto done;
1812 
1813 		free(id);
1814 		id = NULL;
1815 	}
1816 done:
1817 	if (err) {
1818 		if (err->code == GOT_ERR_LOCKFILE_TIMEOUT) {
1819 			err = got_error_fmt(GOT_ERR_LOCKFILE_TIMEOUT,
1820 			    "could not acquire exclusive file lock for %s",
1821 			    refname);
1822 		}
1823 		send_ref_update_ng(client, &iref, refname, err->msg);
1824 	} else
1825 		send_ref_update_ok(client, &iref, refname);
1826 
1827 	if (client->nref_updates > 0) {
1828 		client->nref_updates--;
1829 		if (client->nref_updates == 0)
1830 			send_refs_updated(client);
1831 
1832 	}
1833 	if (locked) {
1834 		const struct got_error *unlock_err;
1835 		unlock_err = got_ref_unlock(ref);
1836 		if (unlock_err && err == NULL)
1837 			err = unlock_err;
1838 	}
1839 	if (ref)
1840 		got_ref_close(ref);
1841 	if (obj)
1842 		got_object_close(obj);
1843 	if (repo)
1844 		got_repo_close(repo);
1845 	free(refname);
1846 	free(id);
1847 	return err;
1848 }
1849 
1850 static void
1851 gotd_dispatch(int fd, short event, void *arg)
1852 {
1853 	struct gotd_imsgev *iev = arg;
1854 	struct imsgbuf *ibuf = &iev->ibuf;
1855 	struct gotd_child_proc *proc = NULL;
1856 	ssize_t n;
1857 	int shut = 0;
1858 	struct imsg imsg;
1859 
1860 	if (event & EV_READ) {
1861 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1862 			fatal("imsg_read error");
1863 		if (n == 0) {
1864 			/* Connection closed. */
1865 			shut = 1;
1866 			goto done;
1867 		}
1868 	}
1869 
1870 	if (event & EV_WRITE) {
1871 		n = msgbuf_write(&ibuf->w);
1872 		if (n == -1 && errno != EAGAIN)
1873 			fatal("msgbuf_write");
1874 		if (n == 0) {
1875 			/* Connection closed. */
1876 			shut = 1;
1877 			goto done;
1878 		}
1879 	}
1880 
1881 	proc = find_proc_by_fd(fd);
1882 	if (proc == NULL)
1883 		fatalx("cannot find child process for fd %d", fd);
1884 
1885 	for (;;) {
1886 		const struct got_error *err = NULL;
1887 		struct gotd_client *client = NULL;
1888 		uint32_t client_id = 0;
1889 		int do_disconnect = 0;
1890 		int do_ref_updates = 0, do_ref_update = 0;
1891 		int do_packfile_install = 0;
1892 
1893 		if ((n = imsg_get(ibuf, &imsg)) == -1)
1894 			fatal("%s: imsg_get error", __func__);
1895 		if (n == 0)	/* No more messages. */
1896 			break;
1897 
1898 		switch (imsg.hdr.type) {
1899 		case GOTD_IMSG_ERROR:
1900 			do_disconnect = 1;
1901 			err = gotd_imsg_recv_error(&client_id, &imsg);
1902 			break;
1903 		case GOTD_IMSG_PACKFILE_DONE:
1904 			do_disconnect = 1;
1905 			err = recv_packfile_done(&client_id, &imsg);
1906 			break;
1907 		case GOTD_IMSG_PACKFILE_INSTALL:
1908 			err = recv_packfile_install(&client_id, &imsg);
1909 			if (err == NULL)
1910 				do_packfile_install = 1;
1911 			break;
1912 		case GOTD_IMSG_REF_UPDATES_START:
1913 			err = recv_ref_updates_start(&client_id, &imsg);
1914 			if (err == NULL)
1915 				do_ref_updates = 1;
1916 			break;
1917 		case GOTD_IMSG_REF_UPDATE:
1918 			err = recv_ref_update(&client_id, &imsg);
1919 			if (err == NULL)
1920 				do_ref_update = 1;
1921 			break;
1922 		default:
1923 			log_debug("unexpected imsg %d", imsg.hdr.type);
1924 			break;
1925 		}
1926 
1927 		client = find_client(client_id);
1928 		if (client == NULL) {
1929 			log_warnx("%s: client not found", __func__);
1930 			imsg_free(&imsg);
1931 			continue;
1932 		}
1933 
1934 		if (!verify_imsg_src(client, proc, &imsg)) {
1935 			log_debug("dropping imsg type %d from PID %d",
1936 			    imsg.hdr.type, proc->pid);
1937 			imsg_free(&imsg);
1938 			continue;
1939 		}
1940 		if (err)
1941 			log_warnx("uid %d: %s", client->euid, err->msg);
1942 
1943 		if (do_disconnect) {
1944 			if (err)
1945 				disconnect_on_error(client, err);
1946 			else
1947 				disconnect(client);
1948 		} else {
1949 			if (do_packfile_install)
1950 				err = install_pack(client, proc->chroot_path,
1951 				    &imsg);
1952 			else if (do_ref_updates)
1953 				err = begin_ref_updates(client, &imsg);
1954 			else if (do_ref_update)
1955 				err = update_ref(client, proc->chroot_path,
1956 				    &imsg);
1957 			if (err)
1958 				log_warnx("uid %d: %s", client->euid, err->msg);
1959 		}
1960 		imsg_free(&imsg);
1961 	}
1962 done:
1963 	if (!shut) {
1964 		gotd_imsg_event_add(iev);
1965 	} else {
1966 		/* This pipe is dead. Remove its event handler */
1967 		event_del(&iev->ev);
1968 		event_loopexit(NULL);
1969 	}
1970 }
1971 
1972 static pid_t
1973 start_child(enum gotd_procid proc_id, const char *chroot_path,
1974     char *argv0, const char *confpath, int fd, int daemonize, int verbosity)
1975 {
1976 	char	*argv[11];
1977 	int	 argc = 0;
1978 	pid_t	 pid;
1979 
1980 	switch (pid = fork()) {
1981 	case -1:
1982 		fatal("cannot fork");
1983 	case 0:
1984 		break;
1985 	default:
1986 		close(fd);
1987 		return pid;
1988 	}
1989 
1990 	if (fd != GOTD_SOCK_FILENO) {
1991 		if (dup2(fd, GOTD_SOCK_FILENO) == -1)
1992 			fatal("cannot setup imsg fd");
1993 	} else if (fcntl(fd, F_SETFD, 0) == -1)
1994 		fatal("cannot setup imsg fd");
1995 
1996 	argv[argc++] = argv0;
1997 	switch (proc_id) {
1998 	case PROC_REPO_READ:
1999 		argv[argc++] = (char *)"-R";
2000 		break;
2001 	case PROC_REPO_WRITE:
2002 		argv[argc++] = (char *)"-W";
2003 		break;
2004 	default:
2005 		fatalx("invalid process id %d", proc_id);
2006 	}
2007 
2008 	argv[argc++] = (char *)"-f";
2009 	argv[argc++] = (char *)confpath;
2010 
2011 	argv[argc++] = (char *)"-P";
2012 	argv[argc++] = (char *)chroot_path;
2013 
2014 	if (!daemonize)
2015 		argv[argc++] = (char *)"-d";
2016 	if (verbosity > 0)
2017 		argv[argc++] = (char *)"-v";
2018 	if (verbosity > 1)
2019 		argv[argc++] = (char *)"-v";
2020 	argv[argc++] = NULL;
2021 
2022 	execvp(argv0, argv);
2023 	fatal("execvp");
2024 }
2025 
2026 static void
2027 start_repo_children(struct gotd *gotd, char *argv0, const char *confpath,
2028     int daemonize, int verbosity)
2029 {
2030 	struct gotd_repo *repo = NULL;
2031 	struct gotd_child_proc *proc;
2032 	int i;
2033 
2034 	/*
2035 	 * XXX For now, use one reader and one writer per repository.
2036 	 * This should be changed to N readers + M writers.
2037 	 */
2038 	gotd->nprocs = gotd->nrepos * 2;
2039 	gotd->procs = calloc(gotd->nprocs, sizeof(*gotd->procs));
2040 	if (gotd->procs == NULL)
2041 		fatal("calloc");
2042 	for (i = 0; i < gotd->nprocs; i++) {
2043 		if (repo == NULL)
2044 			repo = TAILQ_FIRST(&gotd->repos);
2045 		proc = &gotd->procs[i];
2046 		if (i < gotd->nrepos)
2047 			proc->type = PROC_REPO_READ;
2048 		else
2049 			proc->type = PROC_REPO_WRITE;
2050 		if (strlcpy(proc->repo_name, repo->name,
2051 		    sizeof(proc->repo_name)) >= sizeof(proc->repo_name))
2052 			fatalx("repository name too long: %s", repo->name);
2053 		log_debug("adding repository %s", repo->name);
2054 		if (realpath(repo->path, proc->chroot_path) == NULL)
2055 			fatal("%s", repo->path);
2056 		if (socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK,
2057 		    PF_UNSPEC, proc->pipe) == -1)
2058 			fatal("socketpair");
2059 		proc->pid = start_child(proc->type, proc->chroot_path, argv0,
2060 		    confpath, proc->pipe[1], daemonize, verbosity);
2061 		imsg_init(&proc->iev.ibuf, proc->pipe[0]);
2062 		log_debug("proc %s %s is on fd %d",
2063 		    gotd_proc_names[proc->type], proc->chroot_path,
2064 		    proc->pipe[0]);
2065 		proc->iev.handler = gotd_dispatch;
2066 		proc->iev.events = EV_READ;
2067 		proc->iev.handler_arg = NULL;
2068 		event_set(&proc->iev.ev, proc->iev.ibuf.fd, EV_READ,
2069 		    gotd_dispatch, &proc->iev);
2070 
2071 		repo = TAILQ_NEXT(repo, entry);
2072 	}
2073 }
2074 
2075 static void
2076 apply_unveil(void)
2077 {
2078 	struct gotd_repo *repo;
2079 
2080 	TAILQ_FOREACH(repo, &gotd.repos, entry) {
2081 		if (unveil(repo->path, "rwc") == -1)
2082 			fatal("unveil %s", repo->path);
2083 	}
2084 
2085 	if (unveil(GOT_TMPDIR_STR, "rwc") == -1)
2086 		fatal("unveil %s", GOT_TMPDIR_STR);
2087 
2088 	if (unveil(NULL, NULL) == -1)
2089 		fatal("unveil");
2090 }
2091 
2092 int
2093 main(int argc, char **argv)
2094 {
2095 	const struct got_error *error = NULL;
2096 	int ch, fd = -1, daemonize = 1, verbosity = 0, noaction = 0;
2097 	const char *confpath = GOTD_CONF_PATH;
2098 	char *argv0 = argv[0];
2099 	char title[2048];
2100 	int ngroups = NGROUPS_MAX;
2101 	struct passwd *pw = NULL;
2102 	struct group *gr = NULL;
2103 	char *repo_path = NULL;
2104 	enum gotd_procid proc_id = PROC_GOTD;
2105 	struct event evsigint, evsigterm, evsighup, evsigusr1;
2106 	int *pack_fds = NULL, *temp_fds = NULL;
2107 
2108 	log_init(1, LOG_DAEMON); /* Log to stderr until daemonized. */
2109 
2110 	while ((ch = getopt(argc, argv, "df:nP:RvW")) != -1) {
2111 		switch (ch) {
2112 		case 'd':
2113 			daemonize = 0;
2114 			break;
2115 		case 'f':
2116 			confpath = optarg;
2117 			break;
2118 		case 'n':
2119 			noaction = 1;
2120 			break;
2121 		case 'P':
2122 			repo_path = realpath(optarg, NULL);
2123 			if (repo_path == NULL)
2124 				fatal("realpath '%s'", optarg);
2125 			break;
2126 		case 'R':
2127 			proc_id = PROC_REPO_READ;
2128 			break;
2129 		case 'v':
2130 			if (verbosity < 3)
2131 				verbosity++;
2132 			break;
2133 		case 'W':
2134 			proc_id = PROC_REPO_WRITE;
2135 			break;
2136 		default:
2137 			usage();
2138 		}
2139 	}
2140 
2141 	argc -= optind;
2142 	argv += optind;
2143 
2144 	if (argc != 0)
2145 		usage();
2146 
2147 	if (geteuid())
2148 		fatalx("need root privileges");
2149 
2150 	log_init(daemonize ? 0 : 1, LOG_DAEMON);
2151 	log_setverbose(verbosity);
2152 
2153 	if (parse_config(confpath, proc_id, &gotd) != 0)
2154 		return 1;
2155 
2156 	if (proc_id == PROC_GOTD &&
2157 	    (gotd.nrepos == 0 || TAILQ_EMPTY(&gotd.repos)))
2158 		fatalx("no repository defined in configuration file");
2159 
2160 	pw = getpwnam(gotd.user_name);
2161 	if (pw == NULL)
2162 		fatal("getpwuid: user %s not found", gotd.user_name);
2163 
2164 	if (pw->pw_uid == 0) {
2165 		fatalx("cannot run %s as %s: the user running %s "
2166 		    "must not be the superuser",
2167 		    getprogname(), pw->pw_name, getprogname());
2168 	}
2169 
2170 	if (getgrouplist(pw->pw_name, pw->pw_gid, gotd.groups, &ngroups) == -1)
2171 		log_warnx("group membership list truncated");
2172 	gotd.ngroups = ngroups;
2173 
2174 	gr = match_group(gotd.groups, ngroups, gotd.unix_group_name);
2175 	if (gr == NULL) {
2176 		fatalx("cannot start %s: the user running %s "
2177 		    "must be a secondary member of group %s",
2178 		    getprogname(), getprogname(), gotd.unix_group_name);
2179 	}
2180 	if (gr->gr_gid == pw->pw_gid) {
2181 		fatalx("cannot start %s: the user running %s "
2182 		    "must be a secondary member of group %s, but "
2183 		    "%s is the user's primary group",
2184 		    getprogname(), getprogname(), gotd.unix_group_name,
2185 		    gotd.unix_group_name);
2186 	}
2187 
2188 	if (proc_id == PROC_GOTD &&
2189 	    !got_path_is_absolute(gotd.unix_socket_path))
2190 		fatalx("bad unix socket path \"%s\": must be an absolute path",
2191 		    gotd.unix_socket_path);
2192 
2193 	if (noaction)
2194 		return 0;
2195 
2196 	if (proc_id == PROC_GOTD && verbosity) {
2197 		log_info("socket: %s", gotd.unix_socket_path);
2198 		log_info("user: %s", pw->pw_name);
2199 		log_info("secondary group: %s", gr->gr_name);
2200 
2201 		fd = unix_socket_listen(gotd.unix_socket_path, pw->pw_uid,
2202 		    gr->gr_gid);
2203 		if (fd == -1) {
2204 			fatal("cannot listen on unix socket %s",
2205 			    gotd.unix_socket_path);
2206 		}
2207 	}
2208 
2209 	if (proc_id == PROC_GOTD) {
2210 		gotd.pid = getpid();
2211 		snprintf(title, sizeof(title), "%s", gotd_proc_names[proc_id]);
2212 		start_repo_children(&gotd, argv0, confpath, daemonize,
2213 		    verbosity);
2214 		arc4random_buf(&clients_hash_key, sizeof(clients_hash_key));
2215 		if (daemonize && daemon(0, 0) == -1)
2216 			fatal("daemon");
2217 	} else if (proc_id == PROC_REPO_READ || proc_id == PROC_REPO_WRITE) {
2218 		error = got_repo_pack_fds_open(&pack_fds);
2219 		if (error != NULL)
2220 			fatalx("cannot open pack tempfiles: %s", error->msg);
2221 		error = got_repo_temp_fds_open(&temp_fds);
2222 		if (error != NULL)
2223 			fatalx("cannot open pack tempfiles: %s", error->msg);
2224 		if (repo_path == NULL)
2225 			fatalx("repository path not specified");
2226 		snprintf(title, sizeof(title), "%s %s",
2227 		    gotd_proc_names[proc_id], repo_path);
2228 		if (chroot(repo_path) == -1)
2229 			fatal("chroot");
2230 		if (chdir("/") == -1)
2231 			fatal("chdir(\"/\")");
2232 		if (daemonize && daemon(1, 0) == -1)
2233 			fatal("daemon");
2234 	} else
2235 		fatal("invalid process id %d", proc_id);
2236 
2237 	setproctitle("%s", title);
2238 	log_procinit(title);
2239 
2240 	/* Drop root privileges. */
2241 	if (setgid(pw->pw_gid) == -1)
2242 		fatal("setgid %d failed", pw->pw_gid);
2243 	if (setuid(pw->pw_uid) == -1)
2244 		fatal("setuid %d failed", pw->pw_uid);
2245 
2246 	event_init();
2247 
2248 	switch (proc_id) {
2249 	case PROC_GOTD:
2250 #ifndef PROFILE
2251 		if (pledge("stdio rpath wpath cpath proc getpw sendfd recvfd "
2252 		    "fattr flock unix unveil", NULL) == -1)
2253 			err(1, "pledge");
2254 #endif
2255 		break;
2256 	case PROC_REPO_READ:
2257 #ifndef PROFILE
2258 		if (pledge("stdio rpath recvfd", NULL) == -1)
2259 			err(1, "pledge");
2260 #endif
2261 		repo_read_main(title, pack_fds, temp_fds);
2262 		/* NOTREACHED */
2263 		exit(0);
2264 	case PROC_REPO_WRITE:
2265 #ifndef PROFILE
2266 		if (pledge("stdio rpath recvfd", NULL) == -1)
2267 			err(1, "pledge");
2268 #endif
2269 		repo_write_main(title, pack_fds, temp_fds);
2270 		/* NOTREACHED */
2271 		exit(0);
2272 	default:
2273 		fatal("invalid process id %d", proc_id);
2274 	}
2275 
2276 	if (proc_id != PROC_GOTD)
2277 		fatal("invalid process id %d", proc_id);
2278 
2279 	apply_unveil();
2280 
2281 	signal_set(&evsigint, SIGINT, gotd_sighdlr, NULL);
2282 	signal_set(&evsigterm, SIGTERM, gotd_sighdlr, NULL);
2283 	signal_set(&evsighup, SIGHUP, gotd_sighdlr, NULL);
2284 	signal_set(&evsigusr1, SIGUSR1, gotd_sighdlr, NULL);
2285 	signal(SIGPIPE, SIG_IGN);
2286 
2287 	signal_add(&evsigint, NULL);
2288 	signal_add(&evsigterm, NULL);
2289 	signal_add(&evsighup, NULL);
2290 	signal_add(&evsigusr1, NULL);
2291 
2292 	event_set(&gotd.ev, fd, EV_READ | EV_PERSIST, gotd_accept, NULL);
2293 	if (event_add(&gotd.ev, NULL))
2294 		fatalx("event add");
2295 	evtimer_set(&gotd.pause, gotd_accept_paused, NULL);
2296 
2297 	event_dispatch();
2298 
2299 	if (fd != -1)
2300 		close(fd);
2301 	if (pack_fds)
2302 		got_repo_pack_fds_close(pack_fds);
2303 	free(repo_path);
2304 	return 0;
2305 }