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Date:: Tue Nov 1 07:41:39 2022 UTC
Message:: use mkstemps(3) instead of mkstemp(3) for opening named temporary files Allows 'got commit' to use a ".diff" suffix for temporary diff files. ok op@
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1 /*
2  * Copyright (c) 2022 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/queue.h>
18 #include <sys/tree.h>
19 #include <sys/time.h>
20 #include <sys/types.h>
21 #include <sys/stat.h>
22 #include <sys/socket.h>
23 #include <sys/un.h>
24 #include <sys/wait.h>
25 
26 #include <fcntl.h>
27 #include <err.h>
28 #include <errno.h>
29 #include <event.h>
30 #include <limits.h>
31 #include <pwd.h>
32 #include <grp.h>
33 #include <imsg.h>
34 #include <sha1.h>
35 #include <signal.h>
36 #include <siphash.h>
37 #include <stdarg.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <syslog.h>
43 #include <unistd.h>
44 
45 #include "got_error.h"
46 #include "got_opentemp.h"
47 #include "got_path.h"
48 #include "got_repository.h"
49 #include "got_object.h"
50 #include "got_reference.h"
51 
52 #include "got_lib_delta.h"
53 #include "got_lib_object.h"
54 #include "got_lib_object_cache.h"
55 #include "got_lib_sha1.h"
56 #include "got_lib_gitproto.h"
57 #include "got_lib_pack.h"
58 #include "got_lib_repository.h"
59 
60 #include "gotd.h"
61 #include "log.h"
62 #include "repo_read.h"
63 #include "repo_write.h"
64 
65 #ifndef nitems
66 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
67 #endif
68 
69 struct gotd_client {
70 	STAILQ_ENTRY(gotd_client)	 entry;
71 	enum gotd_client_state		 state;
72 	struct gotd_client_capability	*capabilities;
73 	size_t				 ncapa_alloc;
74 	size_t				 ncapabilities;
75 	uint32_t			 id;
76 	int				 fd;
77 	int				 delta_cache_fd;
78 	struct gotd_imsgev		 iev;
79 	struct event			 tmo;
80 	uid_t				 euid;
81 	gid_t				 egid;
82 	struct gotd_child_proc		*repo_read;
83 	struct gotd_child_proc		*repo_write;
84 	char				*packfile_path;
85 	char				*packidx_path;
86 	int				 nref_updates;
87 };
88 STAILQ_HEAD(gotd_clients, gotd_client);
89 
90 static struct gotd_clients gotd_clients[GOTD_CLIENT_TABLE_SIZE];
91 static SIPHASH_KEY clients_hash_key;
92 volatile int client_cnt;
93 static struct timeval timeout = { 3600, 0 };
94 static int inflight;
95 static struct gotd gotd;
96 
97 void gotd_sighdlr(int sig, short event, void *arg);
98 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_child_proc *
548 find_proc_by_repo_name(enum gotd_procid proc_id, const char *repo_name)
549 {
550 	struct gotd_child_proc *proc;
551 	int i;
552 	size_t namelen;
553 
554 	for (i = 0; i < gotd.nprocs; i++) {
555 		proc = &gotd.procs[i];
556 		if (proc->type != proc_id)
557 			continue;
558 		namelen = strlen(proc->repo_name);
559 		if (strncmp(proc->repo_name, repo_name, namelen) != 0)
560 			continue;
561 		if (repo_name[namelen] == '\0' ||
562 		    strcmp(&repo_name[namelen], ".git") == 0)
563 			return proc;
564 	}
565 
566 	return NULL;
567 }
568 
569 static struct gotd_child_proc *
570 find_proc_by_fd(int fd)
571 {
572 	struct gotd_child_proc *proc;
573 	int i;
574 
575 	for (i = 0; i < gotd.nprocs; i++) {
576 		proc = &gotd.procs[i];
577 		if (proc->iev.ibuf.fd == fd)
578 			return proc;
579 	}
580 
581 	return NULL;
582 }
583 
584 static const struct got_error *
585 forward_list_refs_request(struct gotd_client *client, struct imsg *imsg)
586 {
587 	const struct got_error *err;
588 	struct gotd_imsg_list_refs ireq;
589 	struct gotd_imsg_list_refs_internal ilref;
590 	struct gotd_child_proc *proc = NULL;
591 	size_t datalen;
592 	int fd = -1;
593 
594 	log_debug("list-refs request from uid %d", client->euid);
595 
596 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
597 	if (datalen != sizeof(ireq))
598 		return got_error(GOT_ERR_PRIVSEP_LEN);
599 
600 	memcpy(&ireq, imsg->data, datalen);
601 
602 	memset(&ilref, 0, sizeof(ilref));
603 	ilref.client_id = client->id;
604 
605 	if (ireq.client_is_reading) {
606 		err = ensure_client_is_not_writing(client);
607 		if (err)
608 			return err;
609 		client->repo_read = find_proc_by_repo_name(PROC_REPO_READ,
610 		    ireq.repo_name);
611 		if (client->repo_read == NULL)
612 			return got_error(GOT_ERR_NOT_GIT_REPO);
613 	} else {
614 		err = ensure_client_is_not_reading(client);
615 		if (err)
616 			return err;
617 		client->repo_write = find_proc_by_repo_name(PROC_REPO_WRITE,
618 		    ireq.repo_name);
619 		if (client->repo_write == NULL)
620 			return got_error(GOT_ERR_NOT_GIT_REPO);
621 	}
622 
623 	fd = dup(client->fd);
624 	if (fd == -1)
625 		return got_error_from_errno("dup");
626 
627 	proc = get_client_proc(client);
628 	if (proc == NULL)
629 		fatalx("no process found for uid %d", client->euid);
630 	if (gotd_imsg_compose_event(&proc->iev,
631 	    GOTD_IMSG_LIST_REFS_INTERNAL, PROC_GOTD, fd,
632 	    &ilref, sizeof(ilref)) == -1) {
633 		err = got_error_from_errno("imsg compose WANT");
634 		close(fd);
635 		return err;
636 	}
637 
638 	return NULL;
639 }
640 
641 static const struct got_error *
642 forward_want(struct gotd_client *client, struct imsg *imsg)
643 {
644 	struct gotd_imsg_want ireq;
645 	struct gotd_imsg_want iwant;
646 	size_t datalen;
647 
648 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
649 	if (datalen != sizeof(ireq))
650 		return got_error(GOT_ERR_PRIVSEP_LEN);
651 
652 	memcpy(&ireq, imsg->data, datalen);
653 
654 	memset(&iwant, 0, sizeof(iwant));
655 	memcpy(iwant.object_id, ireq.object_id, SHA1_DIGEST_LENGTH);
656 	iwant.client_id = client->id;
657 
658 	if (gotd_imsg_compose_event(&client->repo_read->iev, GOTD_IMSG_WANT,
659 	    PROC_GOTD, -1, &iwant, sizeof(iwant)) == -1)
660 		return got_error_from_errno("imsg compose WANT");
661 
662 	return NULL;
663 }
664 
665 static const struct got_error *
666 forward_ref_update(struct gotd_client *client, struct imsg *imsg)
667 {
668 	const struct got_error *err = NULL;
669 	struct gotd_imsg_ref_update ireq;
670 	struct gotd_imsg_ref_update *iref = NULL;
671 	size_t datalen;
672 
673 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
674 	if (datalen < sizeof(ireq))
675 		return got_error(GOT_ERR_PRIVSEP_LEN);
676 	memcpy(&ireq, imsg->data, sizeof(ireq));
677 	if (datalen != sizeof(ireq) + ireq.name_len)
678 		return got_error(GOT_ERR_PRIVSEP_LEN);
679 
680 	iref = malloc(datalen);
681 	if (iref == NULL)
682 		return got_error_from_errno("malloc");
683 	memcpy(iref, imsg->data, datalen);
684 
685 	iref->client_id = client->id;
686 	if (gotd_imsg_compose_event(&client->repo_write->iev,
687 	    GOTD_IMSG_REF_UPDATE, PROC_GOTD, -1, iref, datalen) == -1)
688 		err = got_error_from_errno("imsg compose REF_UPDATE");
689 	free(iref);
690 	return err;
691 }
692 
693 static const struct got_error *
694 forward_have(struct gotd_client *client, struct imsg *imsg)
695 {
696 	struct gotd_imsg_have ireq;
697 	struct gotd_imsg_have ihave;
698 	size_t datalen;
699 
700 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
701 	if (datalen != sizeof(ireq))
702 		return got_error(GOT_ERR_PRIVSEP_LEN);
703 
704 	memcpy(&ireq, imsg->data, datalen);
705 
706 	memset(&ihave, 0, sizeof(ihave));
707 	memcpy(ihave.object_id, ireq.object_id, SHA1_DIGEST_LENGTH);
708 	ihave.client_id = client->id;
709 
710 	if (gotd_imsg_compose_event(&client->repo_read->iev, GOTD_IMSG_HAVE,
711 	    PROC_GOTD, -1, &ihave, sizeof(ihave)) == -1)
712 		return got_error_from_errno("imsg compose HAVE");
713 
714 	return NULL;
715 }
716 
717 static int
718 client_has_capability(struct gotd_client *client, const char *capastr)
719 {
720 	struct gotd_client_capability *capa;
721 	size_t i;
722 
723 	if (client->ncapabilities == 0)
724 		return 0;
725 
726 	for (i = 0; i < client->ncapabilities; i++) {
727 		capa = &client->capabilities[i];
728 		if (strcmp(capa->key, capastr) == 0)
729 			return 1;
730 	}
731 
732 	return 0;
733 }
734 
735 static const struct got_error *
736 recv_capabilities(struct gotd_client *client, struct imsg *imsg)
737 {
738 	struct gotd_imsg_capabilities icapas;
739 	size_t datalen;
740 
741 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
742 	if (datalen != sizeof(icapas))
743 		return got_error(GOT_ERR_PRIVSEP_LEN);
744 	memcpy(&icapas, imsg->data, sizeof(icapas));
745 
746 	client->ncapa_alloc = icapas.ncapabilities;
747 	client->capabilities = calloc(client->ncapa_alloc,
748 	    sizeof(*client->capabilities));
749 	if (client->capabilities == NULL) {
750 		client->ncapa_alloc = 0;
751 		return got_error_from_errno("calloc");
752 	}
753 
754 	log_debug("expecting %zu capabilities from uid %d",
755 	    client->ncapa_alloc, client->euid);
756 	return NULL;
757 }
758 
759 static const struct got_error *
760 recv_capability(struct gotd_client *client, struct imsg *imsg)
761 {
762 	struct gotd_imsg_capability icapa;
763 	struct gotd_client_capability *capa;
764 	size_t datalen;
765 	char *key, *value = NULL;
766 
767 	if (client->capabilities == NULL ||
768 	    client->ncapabilities >= client->ncapa_alloc) {
769 		return got_error_msg(GOT_ERR_BAD_REQUEST,
770 		    "unexpected capability received");
771 	}
772 
773 	memset(&icapa, 0, sizeof(icapa));
774 
775 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
776 	if (datalen < sizeof(icapa))
777 		return got_error(GOT_ERR_PRIVSEP_LEN);
778 	memcpy(&icapa, imsg->data, sizeof(icapa));
779 
780 	if (datalen != sizeof(icapa) + icapa.key_len + icapa.value_len)
781 		return got_error(GOT_ERR_PRIVSEP_LEN);
782 
783 	key = malloc(icapa.key_len + 1);
784 	if (key == NULL)
785 		return got_error_from_errno("malloc");
786 	if (icapa.value_len > 0) {
787 		value = malloc(icapa.value_len + 1);
788 		if (value == NULL) {
789 			free(key);
790 			return got_error_from_errno("malloc");
791 		}
792 	}
793 
794 	memcpy(key, imsg->data + sizeof(icapa), icapa.key_len);
795 	key[icapa.key_len] = '\0';
796 	if (value) {
797 		memcpy(value, imsg->data + sizeof(icapa) + icapa.key_len,
798 		    icapa.value_len);
799 		value[icapa.value_len] = '\0';
800 	}
801 
802 	capa = &client->capabilities[client->ncapabilities++];
803 	capa->key = key;
804 	capa->value = value;
805 
806 	if (value)
807 		log_debug("uid %d: capability %s=%s", client->euid, key, value);
808 	else
809 		log_debug("uid %d: capability %s", client->euid, key);
810 
811 	return NULL;
812 }
813 
814 static const struct got_error *
815 send_packfile(struct gotd_client *client)
816 {
817 	const struct got_error *err = NULL;
818 	struct gotd_imsg_send_packfile ipack;
819 	struct gotd_imsg_packfile_pipe ipipe;
820 	int pipe[2];
821 
822 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe) == -1)
823 		return got_error_from_errno("socketpair");
824 
825 	memset(&ipack, 0, sizeof(ipack));
826 	memset(&ipipe, 0, sizeof(ipipe));
827 
828 	ipack.client_id = client->id;
829 	if (client_has_capability(client, GOT_CAPA_SIDE_BAND_64K))
830 		ipack.report_progress = 1;
831 
832 	client->delta_cache_fd = got_opentempfd();
833 	if (client->delta_cache_fd == -1)
834 		return got_error_from_errno("got_opentempfd");
835 
836 	if (gotd_imsg_compose_event(&client->repo_read->iev,
837 	    GOTD_IMSG_SEND_PACKFILE, PROC_GOTD, client->delta_cache_fd,
838 	    &ipack, sizeof(ipack)) == -1) {
839 		err = got_error_from_errno("imsg compose SEND_PACKFILE");
840 		close(pipe[0]);
841 		close(pipe[1]);
842 		return err;
843 	}
844 
845 	ipipe.client_id = client->id;
846 
847 	/* Send pack pipe end 0 to repo_read. */
848 	if (gotd_imsg_compose_event(&client->repo_read->iev,
849 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[0],
850 	        &ipipe, sizeof(ipipe)) == -1) {
851 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
852 		close(pipe[1]);
853 		return err;
854 	}
855 
856 	/* Send pack pipe end 1 to gotsh(1) (expects just an fd, no data). */
857 	if (gotd_imsg_compose_event(&client->iev,
858 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[1], NULL, 0) == -1)
859 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
860 
861 	return err;
862 }
863 
864 static const struct got_error *
865 recv_packfile(struct gotd_client *client)
866 {
867 	const struct got_error *err = NULL;
868 	struct gotd_imsg_recv_packfile ipack;
869 	struct gotd_imsg_packfile_pipe ipipe;
870 	struct gotd_imsg_packidx_file ifile;
871 	char *basepath = NULL, *pack_path = NULL, *idx_path = NULL;
872 	int packfd = -1, idxfd = -1;
873 	int pipe[2] = { -1, -1 };
874 
875 	if (client->packfile_path) {
876 		return got_error_fmt(GOT_ERR_PRIVSEP_MSG,
877 		    "uid %d already has a pack file", client->euid);
878 	}
879 
880 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe) == -1)
881 		return got_error_from_errno("socketpair");
882 
883 	memset(&ipipe, 0, sizeof(ipipe));
884 	ipipe.client_id = client->id;
885 
886 	/* Send pack pipe end 0 to repo_write. */
887 	if (gotd_imsg_compose_event(&client->repo_write->iev,
888 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[0],
889 	        &ipipe, sizeof(ipipe)) == -1) {
890 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
891 		pipe[0] = -1;
892 		goto done;
893 	}
894 	pipe[0] = -1;
895 
896 	/* Send pack pipe end 1 to gotsh(1) (expects just an fd, no data). */
897 	if (gotd_imsg_compose_event(&client->iev,
898 	    GOTD_IMSG_PACKFILE_PIPE, PROC_GOTD, pipe[1], NULL, 0) == -1)
899 		err = got_error_from_errno("imsg compose PACKFILE_PIPE");
900 	pipe[1] = -1;
901 
902 	if (asprintf(&basepath, "%s/%s/receiving-from-uid-%d.pack",
903 	    client->repo_write->chroot_path, GOT_OBJECTS_PACK_DIR,
904 	    client->euid) == -1) {
905 		err = got_error_from_errno("asprintf");
906 		goto done;
907 	}
908 
909 	err = got_opentemp_named_fd(&pack_path, &packfd, basepath, "");
910 	if (err)
911 		goto done;
912 
913 	free(basepath);
914 	if (asprintf(&basepath, "%s/%s/receiving-from-uid-%d.idx",
915 	    client->repo_write->chroot_path, GOT_OBJECTS_PACK_DIR,
916 	    client->euid) == -1) {
917 		err = got_error_from_errno("asprintf");
918 		basepath = NULL;
919 		goto done;
920 	}
921 	err = got_opentemp_named_fd(&idx_path, &idxfd, basepath, "");
922 	if (err)
923 		goto done;
924 
925 	memset(&ifile, 0, sizeof(ifile));
926 	ifile.client_id = client->id;
927 	if (gotd_imsg_compose_event(&client->repo_write->iev,
928 	    GOTD_IMSG_PACKIDX_FILE, PROC_GOTD, idxfd,
929 	    &ifile, sizeof(ifile)) == -1) {
930 		err = got_error_from_errno("imsg compose PACKIDX_FILE");
931 		idxfd = -1;
932 		goto done;
933 	}
934 	idxfd = -1;
935 
936 	memset(&ipack, 0, sizeof(ipack));
937 	ipack.client_id = client->id;
938 	if (client_has_capability(client, GOT_CAPA_REPORT_STATUS))
939 		ipack.report_status = 1;
940 
941 	if (gotd_imsg_compose_event(&client->repo_write->iev,
942 	    GOTD_IMSG_RECV_PACKFILE, PROC_GOTD, packfd,
943 	    &ipack, sizeof(ipack)) == -1) {
944 		err = got_error_from_errno("imsg compose RECV_PACKFILE");
945 		packfd = -1;
946 		goto done;
947 	}
948 	packfd = -1;
949 
950 done:
951 	free(basepath);
952 	if (pipe[0] != -1 && close(pipe[0]) == -1 && err == NULL)
953 		err = got_error_from_errno("close");
954 	if (pipe[1] != -1 && close(pipe[1]) == -1 && err == NULL)
955 		err = got_error_from_errno("close");
956 	if (packfd != -1 && close(packfd) == -1 && err == NULL)
957 		err = got_error_from_errno("close");
958 	if (idxfd != -1 && close(idxfd) == -1 && err == NULL)
959 		err = got_error_from_errno("close");
960 	if (err) {
961 		free(pack_path);
962 		free(idx_path);
963 	} else {
964 		client->packfile_path = pack_path;
965 		client->packidx_path = idx_path;
966 	}
967 	return err;
968 }
969 
970 static void
971 gotd_request(int fd, short events, void *arg)
972 {
973 	struct gotd_imsgev *iev = arg;
974 	struct imsgbuf *ibuf = &iev->ibuf;
975 	struct gotd_client *client = iev->handler_arg;
976 	const struct got_error *err = NULL;
977 	struct imsg imsg;
978 	ssize_t n;
979 
980 	if (events & EV_WRITE) {
981 		while (ibuf->w.queued) {
982 			n = msgbuf_write(&ibuf->w);
983 			if (n == -1 && errno == EPIPE) {
984 				/*
985 				 * The client has closed its socket.
986 				 * This can happen when Git clients are
987 				 * done sending pack file data.
988 				*/
989 				msgbuf_clear(&ibuf->w);
990 				continue;
991 			} else if (n == -1 && errno != EAGAIN) {
992 				err = got_error_from_errno("imsg_flush");
993 				disconnect_on_error(client, err);
994 				return;
995 			}
996 			if (n == 0) {
997 				/* Connection closed. */
998 				err = got_error(GOT_ERR_EOF);
999 				disconnect_on_error(client, err);
1000 				return;
1001 			}
1002 		}
1003 
1004 		/* Disconnect gotctl(8) now that messages have been sent. */
1005 		if (!client_is_reading(client) && !client_is_writing(client)) {
1006 			disconnect(client);
1007 			return;
1008 		}
1009 	}
1010 
1011 	if ((events & EV_READ) == 0)
1012 		return;
1013 
1014 	memset(&imsg, 0, sizeof(imsg));
1015 
1016 	while (err == NULL) {
1017 		err = gotd_imsg_recv(&imsg, ibuf, 0);
1018 		if (err) {
1019 			if (err->code == GOT_ERR_PRIVSEP_READ)
1020 				err = NULL;
1021 			break;
1022 		}
1023 
1024 		evtimer_del(&client->tmo);
1025 
1026 		switch (imsg.hdr.type) {
1027 		case GOTD_IMSG_INFO:
1028 			err = send_info(client);
1029 			break;
1030 		case GOTD_IMSG_STOP:
1031 			err = stop_gotd(client);
1032 			break;
1033 		case GOTD_IMSG_LIST_REFS:
1034 			if (client->state != GOTD_STATE_EXPECT_LIST_REFS) {
1035 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1036 				    "unexpected list-refs request received");
1037 				break;
1038 			}
1039 			err = forward_list_refs_request(client, &imsg);
1040 			if (err)
1041 				break;
1042 			client->state = GOTD_STATE_EXPECT_CAPABILITIES;
1043 			log_debug("uid %d: expecting capabilities",
1044 			    client->euid);
1045 			break;
1046 		case GOTD_IMSG_CAPABILITIES:
1047 			if (client->state != GOTD_STATE_EXPECT_CAPABILITIES) {
1048 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1049 				    "unexpected capabilities received");
1050 				break;
1051 			}
1052 			log_debug("receiving capabilities from uid %d",
1053 			    client->euid);
1054 			err = recv_capabilities(client, &imsg);
1055 			break;
1056 		case GOTD_IMSG_CAPABILITY:
1057 			if (client->state != GOTD_STATE_EXPECT_CAPABILITIES) {
1058 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1059 				    "unexpected capability received");
1060 				break;
1061 			}
1062 			err = recv_capability(client, &imsg);
1063 			if (err || client->ncapabilities < client->ncapa_alloc)
1064 				break;
1065 			if (client_is_reading(client)) {
1066 				client->state = GOTD_STATE_EXPECT_WANT;
1067 				log_debug("uid %d: expecting want-lines",
1068 				    client->euid);
1069 			} else if (client_is_writing(client)) {
1070 				client->state = GOTD_STATE_EXPECT_REF_UPDATE;
1071 				log_debug("uid %d: expecting ref-update-lines",
1072 				    client->euid);
1073 			} else
1074 				fatalx("client %d is both reading and writing",
1075 				    client->euid);
1076 			break;
1077 		case GOTD_IMSG_WANT:
1078 			if (client->state != GOTD_STATE_EXPECT_WANT) {
1079 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1080 				    "unexpected want-line received");
1081 				break;
1082 			}
1083 			log_debug("received want-line from uid %d",
1084 			    client->euid);
1085 			err = ensure_client_is_reading(client);
1086 			if (err)
1087 				break;
1088 			err = forward_want(client, &imsg);
1089 			break;
1090 		case GOTD_IMSG_REF_UPDATE:
1091 			if (client->state != GOTD_STATE_EXPECT_REF_UPDATE) {
1092 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1093 				    "unexpected ref-update-line received");
1094 				break;
1095 			}
1096 			log_debug("received ref-update-line from uid %d",
1097 			    client->euid);
1098 			err = ensure_client_is_writing(client);
1099 			if (err)
1100 				break;
1101 			err = forward_ref_update(client, &imsg);
1102 			if (err)
1103 				break;
1104 			client->state = GOTD_STATE_EXPECT_MORE_REF_UPDATES;
1105 			break;
1106 		case GOTD_IMSG_HAVE:
1107 			if (client->state != GOTD_STATE_EXPECT_HAVE) {
1108 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1109 				    "unexpected have-line received");
1110 				break;
1111 			}
1112 			log_debug("received have-line from uid %d",
1113 			    client->euid);
1114 			err = ensure_client_is_reading(client);
1115 			if (err)
1116 				break;
1117 			err = forward_have(client, &imsg);
1118 			if (err)
1119 				break;
1120 			break;
1121 		case GOTD_IMSG_FLUSH:
1122 			if (client->state == GOTD_STATE_EXPECT_WANT ||
1123 			    client->state == GOTD_STATE_EXPECT_HAVE) {
1124 				err = ensure_client_is_reading(client);
1125 				if (err)
1126 					break;
1127 			} else if (client->state ==
1128 			    GOTD_STATE_EXPECT_MORE_REF_UPDATES) {
1129 				err = ensure_client_is_writing(client);
1130 				if (err)
1131 					break;
1132 			} else {
1133 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1134 				    "unexpected flush-pkt received");
1135 				break;
1136 			}
1137 			log_debug("received flush-pkt from uid %d",
1138 			    client->euid);
1139 			if (client->state == GOTD_STATE_EXPECT_WANT) {
1140 				client->state = GOTD_STATE_EXPECT_HAVE;
1141 				log_debug("uid %d: expecting have-lines",
1142 				    client->euid);
1143 			} else if (client->state == GOTD_STATE_EXPECT_HAVE) {
1144 				client->state = GOTD_STATE_EXPECT_DONE;
1145 				log_debug("uid %d: expecting 'done'",
1146 				    client->euid);
1147 			} else if (client->state ==
1148 			    GOTD_STATE_EXPECT_MORE_REF_UPDATES) {
1149 				client->state = GOTD_STATE_EXPECT_PACKFILE;
1150 				log_debug("uid %d: expecting packfile",
1151 				    client->euid);
1152 				err = recv_packfile(client);
1153 			} else {
1154 				/* should not happen, see above */
1155 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1156 				    "unexpected client state");
1157 				break;
1158 			}
1159 			break;
1160 		case GOTD_IMSG_DONE:
1161 			if (client->state != GOTD_STATE_EXPECT_HAVE &&
1162 			    client->state != GOTD_STATE_EXPECT_DONE) {
1163 				err = got_error_msg(GOT_ERR_BAD_REQUEST,
1164 				    "unexpected flush-pkt received");
1165 				break;
1166 			}
1167 			log_debug("received 'done' from uid %d", client->euid);
1168 			err = ensure_client_is_reading(client);
1169 			if (err)
1170 				break;
1171 			client->state = GOTD_STATE_DONE;
1172 			err = send_packfile(client);
1173 			break;
1174 		default:
1175 			err = got_error(GOT_ERR_PRIVSEP_MSG);
1176 			break;
1177 		}
1178 
1179 		imsg_free(&imsg);
1180 	}
1181 
1182 	if (err) {
1183 		if (err->code != GOT_ERR_EOF ||
1184 		    client->state != GOTD_STATE_EXPECT_PACKFILE)
1185 			disconnect_on_error(client, err);
1186 	} else {
1187 		gotd_imsg_event_add(&client->iev);
1188 		evtimer_add(&client->tmo, &timeout);
1189 	}
1190 }
1191 
1192 static void
1193 gotd_request_timeout(int fd, short events, void *arg)
1194 {
1195 	struct gotd_client *client = arg;
1196 
1197 	log_debug("disconnecting uid %d due to timeout", client->euid);
1198 	disconnect(client);
1199 }
1200 
1201 static void
1202 gotd_accept(int fd, short event, void *arg)
1203 {
1204 	struct sockaddr_storage ss;
1205 	struct timeval backoff;
1206 	socklen_t len;
1207 	int s = -1;
1208 	struct gotd_client *client = NULL;
1209 	uid_t euid;
1210 	gid_t egid;
1211 
1212 	backoff.tv_sec = 1;
1213 	backoff.tv_usec = 0;
1214 
1215 	if (event_add(&gotd.ev, NULL) == -1) {
1216 		log_warn("event_add");
1217 		return;
1218 	}
1219 	if (event & EV_TIMEOUT)
1220 		return;
1221 
1222 	len = sizeof(ss);
1223 
1224 	s = accept_reserve(fd, (struct sockaddr *)&ss, &len, GOTD_FD_RESERVE,
1225 	    &inflight);
1226 
1227 	if (s == -1) {
1228 		switch (errno) {
1229 		case EINTR:
1230 		case EWOULDBLOCK:
1231 		case ECONNABORTED:
1232 			return;
1233 		case EMFILE:
1234 		case ENFILE:
1235 			event_del(&gotd.ev);
1236 			evtimer_add(&gotd.pause, &backoff);
1237 			return;
1238 		default:
1239 			log_warn("%s: accept", __func__);
1240 			return;
1241 		}
1242 	}
1243 
1244 	if (client_cnt >= GOTD_MAXCLIENTS)
1245 		goto err;
1246 
1247 	if (getpeereid(s, &euid, &egid) == -1) {
1248 		log_warn("%s: getpeereid", __func__);
1249 		goto err;
1250 	}
1251 
1252 	client = calloc(1, sizeof(*client));
1253 	if (client == NULL) {
1254 		log_warn("%s: calloc", __func__);
1255 		goto err;
1256 	}
1257 
1258 	client->state = GOTD_STATE_EXPECT_LIST_REFS;
1259 	client->id = get_client_id();
1260 	client->fd = s;
1261 	s = -1;
1262 	client->delta_cache_fd = -1;
1263 	client->euid = euid;
1264 	client->egid = egid;
1265 	client->nref_updates = -1;
1266 
1267 	imsg_init(&client->iev.ibuf, client->fd);
1268 	client->iev.handler = gotd_request;
1269 	client->iev.events = EV_READ;
1270 	client->iev.handler_arg = client;
1271 
1272 	event_set(&client->iev.ev, client->fd, EV_READ, gotd_request,
1273 	    &client->iev);
1274 	gotd_imsg_event_add(&client->iev);
1275 
1276 	evtimer_set(&client->tmo, gotd_request_timeout, client);
1277 
1278 	add_client(client);
1279 	log_debug("%s: new client uid %d connected on fd %d", __func__,
1280 	    client->euid, client->fd);
1281 	return;
1282 err:
1283 	inflight--;
1284 	if (s != -1)
1285 		close(s);
1286 	free(client);
1287 }
1288 
1289 static void
1290 gotd_accept_paused(int fd, short event, void *arg)
1291 {
1292 	event_add(&gotd.ev, NULL);
1293 }
1294 
1295 static const char *gotd_proc_names[PROC_MAX] = {
1296 	"parent",
1297 	"repo_read",
1298 	"repo_write"
1299 };
1300 
1301 static struct gotd_child_proc *
1302 get_proc_for_pid(pid_t pid)
1303 {
1304 	struct gotd_child_proc *proc;
1305 	int i;
1306 
1307 	for (i = 0; i < gotd.nprocs; i++) {
1308 		proc = &gotd.procs[i];
1309 		if (proc->pid == pid)
1310 			return proc;
1311 	}
1312 
1313 	return NULL;
1314 }
1315 
1316 static void
1317 kill_proc(struct gotd_child_proc *proc, int fatal)
1318 {
1319 	if (fatal) {
1320 		log_warnx("sending SIGKILL to PID %d", proc->pid);
1321 		kill(proc->pid, SIGKILL);
1322 	} else
1323 		kill(proc->pid, SIGTERM);
1324 }
1325 
1326 static void
1327 gotd_shutdown(void)
1328 {
1329 	pid_t	 pid;
1330 	int	 status, i;
1331 	struct gotd_child_proc *proc;
1332 
1333 	for (i = 0; i < gotd.nprocs; i++) {
1334 		proc = &gotd.procs[i];
1335 		msgbuf_clear(&proc->iev.ibuf.w);
1336 		close(proc->iev.ibuf.fd);
1337 		kill_proc(proc, 0);
1338 	}
1339 
1340 	log_debug("waiting for children to terminate");
1341 	do {
1342 		pid = wait(&status);
1343 		if (pid == -1) {
1344 			if (errno != EINTR && errno != ECHILD)
1345 				fatal("wait");
1346 		} else if (WIFSIGNALED(status)) {
1347 			proc = get_proc_for_pid(pid);
1348 			log_warnx("%s %s child process terminated; signal %d",
1349 			    proc ? gotd_proc_names[proc->type] : "",
1350 			    proc ? proc->chroot_path : "", WTERMSIG(status));
1351 		}	
1352 	} while (pid != -1 || (pid == -1 && errno == EINTR));
1353 
1354 	log_info("terminating");
1355 	exit(0);
1356 }
1357 
1358 void
1359 gotd_sighdlr(int sig, short event, void *arg)
1360 {
1361 	/*
1362 	 * Normal signal handler rules don't apply because libevent
1363 	 * decouples for us.
1364 	 */
1365 
1366 	switch (sig) {
1367 	case SIGHUP:
1368 		log_info("%s: ignoring SIGHUP", __func__);
1369 		break;
1370 	case SIGUSR1:
1371 		log_info("%s: ignoring SIGUSR1", __func__);
1372 		break;
1373 	case SIGTERM:
1374 	case SIGINT:
1375 		gotd_shutdown();
1376 		log_warnx("gotd terminating");
1377 		exit(0);
1378 		break;
1379 	default:
1380 		fatalx("unexpected signal");
1381 	}
1382 }
1383 
1384 static const struct got_error *
1385 ensure_proc_is_reading(struct gotd_client *client,
1386     struct gotd_child_proc *proc)
1387 {
1388 	if (!client_is_reading(client)) {
1389 		kill_proc(proc, 1);
1390 		return got_error_fmt(GOT_ERR_BAD_PACKET,
1391 		    "PID %d handled a read-request for uid %d but this "
1392 		    "user is not reading from a repository", proc->pid,
1393 		    client->euid);
1394 	}
1395 
1396 	return NULL;
1397 }
1398 
1399 static const struct got_error *
1400 ensure_proc_is_writing(struct gotd_client *client,
1401     struct gotd_child_proc *proc)
1402 {
1403 	if (!client_is_writing(client)) {
1404 		kill_proc(proc, 1);
1405 		return got_error_fmt(GOT_ERR_BAD_PACKET,
1406 		    "PID %d handled a write-request for uid %d but this "
1407 		    "user is not writing to a repository", proc->pid,
1408 		    client->euid);
1409 	}
1410 
1411 	return NULL;
1412 }
1413 
1414 static int
1415 verify_imsg_src(struct gotd_client *client, struct gotd_child_proc *proc,
1416     struct imsg *imsg)
1417 {
1418 	const struct got_error *err;
1419 	struct gotd_child_proc *client_proc;
1420 	int ret = 0;
1421 
1422 	client_proc = get_client_proc(client);
1423 	if (client_proc == NULL)
1424 		fatalx("no process found for uid %d", client->euid);
1425 
1426 	if (proc->pid != client_proc->pid) {
1427 		kill_proc(proc, 1);
1428 		log_warnx("received message from PID %d for uid %d, while "
1429 		    "PID %d is the process serving this user",
1430 		    proc->pid, client->euid, client_proc->pid);
1431 		return 0;
1432 	}
1433 
1434 	switch (imsg->hdr.type) {
1435 	case GOTD_IMSG_ERROR:
1436 		ret = 1;
1437 		break;
1438 	case GOTD_IMSG_PACKFILE_DONE:
1439 		err = ensure_proc_is_reading(client, proc);
1440 		if (err)
1441 			log_warnx("uid %d: %s", client->euid, err->msg);
1442 		else
1443 			ret = 1;
1444 		break;
1445 	case GOTD_IMSG_PACKFILE_INSTALL:
1446 	case GOTD_IMSG_REF_UPDATES_START:
1447 	case GOTD_IMSG_REF_UPDATE:
1448 		err = ensure_proc_is_writing(client, proc);
1449 		if (err)
1450 			log_warnx("uid %d: %s", client->euid, err->msg);
1451 		else
1452 			ret = 1;
1453 		break;
1454 	default:
1455 		log_debug("%s: unexpected imsg %d", __func__, imsg->hdr.type);
1456 		break;
1457 	}
1458 
1459 	return ret;
1460 }
1461 
1462 static const struct got_error *
1463 recv_packfile_done(uint32_t *client_id, struct imsg *imsg)
1464 {
1465 	struct gotd_imsg_packfile_done idone;
1466 	size_t datalen;
1467 
1468 	log_debug("packfile-done received");
1469 
1470 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1471 	if (datalen != sizeof(idone))
1472 		return got_error(GOT_ERR_PRIVSEP_LEN);
1473 	memcpy(&idone, imsg->data, sizeof(idone));
1474 
1475 	*client_id = idone.client_id;
1476 	return NULL;
1477 }
1478 
1479 static const struct got_error *
1480 recv_packfile_install(uint32_t *client_id, struct imsg *imsg)
1481 {
1482 	struct gotd_imsg_packfile_install inst;
1483 	size_t datalen;
1484 
1485 	log_debug("packfile-install received");
1486 
1487 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1488 	if (datalen != sizeof(inst))
1489 		return got_error(GOT_ERR_PRIVSEP_LEN);
1490 	memcpy(&inst, imsg->data, sizeof(inst));
1491 
1492 	*client_id = inst.client_id;
1493 	return NULL;
1494 }
1495 
1496 static const struct got_error *
1497 recv_ref_updates_start(uint32_t *client_id, struct imsg *imsg)
1498 {
1499 	struct gotd_imsg_ref_updates_start istart;
1500 	size_t datalen;
1501 
1502 	log_debug("ref-updates-start received");
1503 
1504 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1505 	if (datalen != sizeof(istart))
1506 		return got_error(GOT_ERR_PRIVSEP_LEN);
1507 	memcpy(&istart, imsg->data, sizeof(istart));
1508 
1509 	*client_id = istart.client_id;
1510 	return NULL;
1511 }
1512 
1513 static const struct got_error *
1514 recv_ref_update(uint32_t *client_id, struct imsg *imsg)
1515 {
1516 	struct gotd_imsg_ref_update iref;
1517 	size_t datalen;
1518 
1519 	log_debug("ref-update received");
1520 
1521 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1522 	if (datalen < sizeof(iref))
1523 		return got_error(GOT_ERR_PRIVSEP_LEN);
1524 	memcpy(&iref, imsg->data, sizeof(iref));
1525 
1526 	*client_id = iref.client_id;
1527 	return NULL;
1528 }
1529 
1530 static const struct got_error *
1531 send_ref_update_ok(struct gotd_client *client,
1532     struct gotd_imsg_ref_update *iref, const char *refname)
1533 {
1534 	struct gotd_imsg_ref_update_ok iok;
1535 	struct ibuf *wbuf;
1536 	size_t len;
1537 
1538 	memset(&iok, 0, sizeof(iok));
1539 	iok.client_id = client->id;
1540 	memcpy(iok.old_id, iref->old_id, SHA1_DIGEST_LENGTH);
1541 	memcpy(iok.new_id, iref->new_id, SHA1_DIGEST_LENGTH);
1542 	iok.name_len = strlen(refname);
1543 
1544 	len = sizeof(iok) + iok.name_len;
1545 	wbuf = imsg_create(&client->iev.ibuf, GOTD_IMSG_REF_UPDATE_OK,
1546 	    PROC_GOTD, gotd.pid, len);
1547 	if (wbuf == NULL)
1548 		return got_error_from_errno("imsg_create REF_UPDATE_OK");
1549 
1550 	if (imsg_add(wbuf, &iok, sizeof(iok)) == -1)
1551 		return got_error_from_errno("imsg_add REF_UPDATE_OK");
1552 	if (imsg_add(wbuf, refname, iok.name_len) == -1)
1553 		return got_error_from_errno("imsg_add REF_UPDATE_OK");
1554 
1555 	wbuf->fd = -1;
1556 	imsg_close(&client->iev.ibuf, wbuf);
1557 	gotd_imsg_event_add(&client->iev);
1558 	return NULL;
1559 }
1560 
1561 static void
1562 send_refs_updated(struct gotd_client *client)
1563 {
1564 	if (gotd_imsg_compose_event(&client->iev,
1565 	    GOTD_IMSG_REFS_UPDATED, PROC_GOTD, -1, NULL, 0) == -1)
1566 		log_warn("imsg compose REFS_UPDATED");
1567 }
1568 
1569 static const struct got_error *
1570 send_ref_update_ng(struct gotd_client *client,
1571     struct gotd_imsg_ref_update *iref, const char *refname,
1572     const char *reason)
1573 {
1574 	const struct got_error *ng_err;
1575 	struct gotd_imsg_ref_update_ng ing;
1576 	struct ibuf *wbuf;
1577 	size_t len;
1578 
1579 	memset(&ing, 0, sizeof(ing));
1580 	ing.client_id = client->id;
1581 	memcpy(ing.old_id, iref->old_id, SHA1_DIGEST_LENGTH);
1582 	memcpy(ing.new_id, iref->new_id, SHA1_DIGEST_LENGTH);
1583 	ing.name_len = strlen(refname);
1584 
1585 	ng_err = got_error_fmt(GOT_ERR_REF_BUSY, "%s", reason);
1586 	ing.reason_len = strlen(ng_err->msg);
1587 
1588 	len = sizeof(ing) + ing.name_len + ing.reason_len;
1589 	wbuf = imsg_create(&client->iev.ibuf, GOTD_IMSG_REF_UPDATE_NG,
1590 	    PROC_GOTD, gotd.pid, len);
1591 	if (wbuf == NULL)
1592 		return got_error_from_errno("imsg_create REF_UPDATE_NG");
1593 
1594 	if (imsg_add(wbuf, &ing, sizeof(ing)) == -1)
1595 		return got_error_from_errno("imsg_add REF_UPDATE_NG");
1596 	if (imsg_add(wbuf, refname, ing.name_len) == -1)
1597 		return got_error_from_errno("imsg_add REF_UPDATE_NG");
1598 	if (imsg_add(wbuf, ng_err->msg, ing.reason_len) == -1)
1599 		return got_error_from_errno("imsg_add REF_UPDATE_NG");
1600 
1601 	wbuf->fd = -1;
1602 	imsg_close(&client->iev.ibuf, wbuf);
1603 	gotd_imsg_event_add(&client->iev);
1604 	return NULL;
1605 }
1606 
1607 static const struct got_error *
1608 install_pack(struct gotd_client *client, const char *repo_path,
1609     struct imsg *imsg)
1610 {
1611 	const struct got_error *err = NULL;
1612 	struct gotd_imsg_packfile_install inst;
1613 	char hex[SHA1_DIGEST_STRING_LENGTH];
1614 	size_t datalen;
1615 	char *packfile_path = NULL, *packidx_path = NULL;
1616 
1617 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1618 	if (datalen != sizeof(inst))
1619 		return got_error(GOT_ERR_PRIVSEP_LEN);
1620 	memcpy(&inst, imsg->data, sizeof(inst));
1621 
1622 	if (client->packfile_path == NULL)
1623 		return got_error_msg(GOT_ERR_BAD_REQUEST,
1624 		    "client has no pack file");
1625 	if (client->packidx_path == NULL)
1626 		return got_error_msg(GOT_ERR_BAD_REQUEST,
1627 		    "client has no pack file index");
1628 
1629 	if (got_sha1_digest_to_str(inst.pack_sha1, hex, sizeof(hex)) == NULL)
1630 		return got_error_msg(GOT_ERR_NO_SPACE,
1631 		    "could not convert pack file SHA1 to hex");
1632 
1633 	if (asprintf(&packfile_path, "/%s/%s/pack-%s.pack",
1634 	    repo_path, GOT_OBJECTS_PACK_DIR, hex) == -1) {
1635 		err = got_error_from_errno("asprintf");
1636 		goto done;
1637 	}
1638 
1639 	if (asprintf(&packidx_path, "/%s/%s/pack-%s.idx",
1640 	    repo_path, GOT_OBJECTS_PACK_DIR, hex) == -1) {
1641 		err = got_error_from_errno("asprintf");
1642 		goto done;
1643 	}
1644 
1645 	if (rename(client->packfile_path, packfile_path) == -1) {
1646 		err = got_error_from_errno3("rename", client->packfile_path,
1647 		    packfile_path);
1648 		goto done;
1649 	}
1650 
1651 	free(client->packfile_path);
1652 	client->packfile_path = NULL;
1653 
1654 	if (rename(client->packidx_path, packidx_path) == -1) {
1655 		err = got_error_from_errno3("rename", client->packidx_path,
1656 		    packidx_path);
1657 		goto done;
1658 	}
1659 
1660 	free(client->packidx_path);
1661 	client->packidx_path = NULL;
1662 done:
1663 	free(packfile_path);
1664 	free(packidx_path);
1665 	return err;
1666 }
1667 
1668 static const struct got_error *
1669 begin_ref_updates(struct gotd_client *client, struct imsg *imsg)
1670 {
1671 	struct gotd_imsg_ref_updates_start istart;
1672 	size_t datalen;
1673 
1674 	if (client->nref_updates != -1)
1675 		return got_error(GOT_ERR_PRIVSEP_MSG);
1676 
1677 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1678 	if (datalen != sizeof(istart))
1679 		return got_error(GOT_ERR_PRIVSEP_LEN);
1680 	memcpy(&istart, imsg->data, sizeof(istart));
1681 
1682 	if (istart.nref_updates <= 0)
1683 		return got_error(GOT_ERR_PRIVSEP_MSG);
1684 
1685 	client->nref_updates = istart.nref_updates;
1686 	return NULL;
1687 }
1688 
1689 static const struct got_error *
1690 update_ref(struct gotd_client *client, const char *repo_path,
1691     struct imsg *imsg)
1692 {
1693 	const struct got_error *err = NULL;
1694 	struct got_repository *repo = NULL;
1695 	struct got_reference *ref = NULL;
1696 	struct gotd_imsg_ref_update iref;
1697 	struct got_object_id old_id, new_id;
1698 	struct got_object_id *id = NULL;
1699 	struct got_object *obj = NULL;
1700 	char *refname = NULL;
1701 	size_t datalen;
1702 	int locked = 0;
1703 
1704 	log_debug("update-ref from uid %d", client->euid);
1705 
1706 	if (client->nref_updates <= 0)
1707 		return got_error(GOT_ERR_PRIVSEP_MSG);
1708 
1709 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
1710 	if (datalen < sizeof(iref))
1711 		return got_error(GOT_ERR_PRIVSEP_LEN);
1712 	memcpy(&iref, imsg->data, sizeof(iref));
1713 	if (datalen != sizeof(iref) + iref.name_len)
1714 		return got_error(GOT_ERR_PRIVSEP_LEN);
1715 	refname = malloc(iref.name_len + 1);
1716 	if (refname == NULL)
1717 		return got_error_from_errno("malloc");
1718 	memcpy(refname, imsg->data + sizeof(iref), iref.name_len);
1719 	refname[iref.name_len] = '\0';
1720 
1721 	log_debug("updating ref %s for uid %d", refname, client->euid);
1722 
1723 	err = got_repo_open(&repo, repo_path, NULL, NULL);
1724 	if (err)
1725 		goto done;
1726 
1727 	memcpy(old_id.sha1, iref.old_id, SHA1_DIGEST_LENGTH);
1728 	memcpy(new_id.sha1, iref.new_id, SHA1_DIGEST_LENGTH);
1729 	err = got_object_open(&obj, repo, &new_id);
1730 	if (err)
1731 		goto done;
1732 
1733 	if (iref.ref_is_new) {
1734 		err = got_ref_open(&ref, repo, refname, 0);
1735 		if (err) {
1736 			if (err->code != GOT_ERR_NOT_REF)
1737 				goto done;
1738 			err = got_ref_alloc(&ref, refname, &new_id);
1739 			if (err)
1740 				goto done;
1741 			err = got_ref_write(ref, repo); /* will lock/unlock */
1742 			if (err)
1743 				goto done;
1744 		} else {
1745 			err = got_error_fmt(GOT_ERR_REF_BUSY,
1746 			    "%s has been created by someone else "
1747 			    "while transaction was in progress",
1748 			    got_ref_get_name(ref));
1749 			goto done;
1750 		}
1751 	} else {
1752 		err = got_ref_open(&ref, repo, refname, 1 /* lock */);
1753 		if (err)
1754 			goto done;
1755 		locked = 1;
1756 
1757 		err = got_ref_resolve(&id, repo, ref);
1758 		if (err)
1759 			goto done;
1760 
1761 		if (got_object_id_cmp(id, &old_id) != 0) {
1762 			err = got_error_fmt(GOT_ERR_REF_BUSY,
1763 			    "%s has been modified by someone else "
1764 			    "while transaction was in progress",
1765 			    got_ref_get_name(ref));
1766 			goto done;
1767 		}
1768 
1769 		err = got_ref_change_ref(ref, &new_id);
1770 		if (err)
1771 			goto done;
1772 
1773 		err = got_ref_write(ref, repo);
1774 		if (err)
1775 			goto done;
1776 
1777 		free(id);
1778 		id = NULL;
1779 	}
1780 done:
1781 	if (err) {
1782 		if (err->code == GOT_ERR_LOCKFILE_TIMEOUT) {
1783 			err = got_error_fmt(GOT_ERR_LOCKFILE_TIMEOUT,
1784 			    "could not acquire exclusive file lock for %s",
1785 			    refname);
1786 		}
1787 		send_ref_update_ng(client, &iref, refname, err->msg);
1788 	} else
1789 		send_ref_update_ok(client, &iref, refname);
1790 
1791 	if (client->nref_updates > 0) {
1792 		client->nref_updates--;
1793 		if (client->nref_updates == 0)
1794 			send_refs_updated(client);
1795 
1796 	}
1797 	if (locked) {
1798 		const struct got_error *unlock_err;
1799 		unlock_err = got_ref_unlock(ref);
1800 		if (unlock_err && err == NULL)
1801 			err = unlock_err;
1802 	}
1803 	if (ref)
1804 		got_ref_close(ref);
1805 	if (obj)
1806 		got_object_close(obj);
1807 	if (repo)
1808 		got_repo_close(repo);
1809 	free(refname);
1810 	free(id);
1811 	return err;
1812 }
1813 
1814 static void
1815 gotd_dispatch(int fd, short event, void *arg)
1816 {
1817 	struct gotd_imsgev *iev = arg;
1818 	struct imsgbuf *ibuf = &iev->ibuf;
1819 	struct gotd_child_proc *proc = NULL;
1820 	ssize_t n;
1821 	int shut = 0;
1822 	struct imsg imsg;
1823 
1824 	if (event & EV_READ) {
1825 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1826 			fatal("imsg_read error");
1827 		if (n == 0) {
1828 			/* Connection closed. */
1829 			shut = 1;
1830 			goto done;
1831 		}
1832 	}
1833 
1834 	if (event & EV_WRITE) {
1835 		n = msgbuf_write(&ibuf->w);
1836 		if (n == -1 && errno != EAGAIN)
1837 			fatal("msgbuf_write");
1838 		if (n == 0) {
1839 			/* Connection closed. */
1840 			shut = 1;
1841 			goto done;
1842 		}
1843 	}
1844 
1845 	proc = find_proc_by_fd(fd);
1846 	if (proc == NULL)
1847 		fatalx("cannot find child process for fd %d", fd);
1848 
1849 	for (;;) {
1850 		const struct got_error *err = NULL;
1851 		struct gotd_client *client = NULL;
1852 		uint32_t client_id = 0;
1853 		int do_disconnect = 0;
1854 		int do_ref_updates = 0, do_ref_update = 0;
1855 		int do_packfile_install = 0;
1856 
1857 		if ((n = imsg_get(ibuf, &imsg)) == -1)
1858 			fatal("%s: imsg_get error", __func__);
1859 		if (n == 0)	/* No more messages. */
1860 			break;
1861 
1862 		switch (imsg.hdr.type) {
1863 		case GOTD_IMSG_ERROR:
1864 			do_disconnect = 1;
1865 			err = gotd_imsg_recv_error(&client_id, &imsg);
1866 			break;
1867 		case GOTD_IMSG_PACKFILE_DONE:
1868 			do_disconnect = 1;
1869 			err = recv_packfile_done(&client_id, &imsg);
1870 			break;
1871 		case GOTD_IMSG_PACKFILE_INSTALL:
1872 			err = recv_packfile_install(&client_id, &imsg);
1873 			if (err == NULL)
1874 				do_packfile_install = 1;
1875 			break;
1876 		case GOTD_IMSG_REF_UPDATES_START:
1877 			err = recv_ref_updates_start(&client_id, &imsg);
1878 			if (err == NULL)
1879 				do_ref_updates = 1;
1880 			break;
1881 		case GOTD_IMSG_REF_UPDATE:
1882 			err = recv_ref_update(&client_id, &imsg);
1883 			if (err == NULL)
1884 				do_ref_update = 1;
1885 			break;
1886 		default:
1887 			log_debug("unexpected imsg %d", imsg.hdr.type);
1888 			break;
1889 		}
1890 
1891 		client = find_client(client_id);
1892 		if (client == NULL) {
1893 			log_warnx("%s: client not found", __func__);
1894 			imsg_free(&imsg);
1895 			continue;
1896 		}
1897 
1898 		if (!verify_imsg_src(client, proc, &imsg)) {
1899 			log_debug("dropping imsg type %d from PID %d",
1900 			    imsg.hdr.type, proc->pid);
1901 			imsg_free(&imsg);
1902 			continue;
1903 		}
1904 		if (err)
1905 			log_warnx("uid %d: %s", client->euid, err->msg);
1906 
1907 		if (do_disconnect) {
1908 			if (err)
1909 				disconnect_on_error(client, err);
1910 			else
1911 				disconnect(client);
1912 		} else if (do_packfile_install)
1913 			err = install_pack(client, proc->chroot_path, &imsg);
1914 		else if (do_ref_updates)
1915 			err = begin_ref_updates(client, &imsg);
1916 		else if (do_ref_update)
1917 			err = update_ref(client, proc->chroot_path, &imsg);
1918 
1919 		if (err)
1920 			log_warnx("uid %d: %s", client->euid, err->msg);
1921 		imsg_free(&imsg);
1922 	}
1923 done:
1924 	if (!shut) {
1925 		gotd_imsg_event_add(iev);
1926 	} else {
1927 		/* This pipe is dead. Remove its event handler */
1928 		event_del(&iev->ev);
1929 		event_loopexit(NULL);
1930 	}
1931 }
1932 
1933 static pid_t
1934 start_child(enum gotd_procid proc_id, const char *chroot_path,
1935     char *argv0, const char *confpath, int fd, int daemonize, int verbosity)
1936 {
1937 	char	*argv[11];
1938 	int	 argc = 0;
1939 	pid_t	 pid;
1940 
1941 	switch (pid = fork()) {
1942 	case -1:
1943 		fatal("cannot fork");
1944 	case 0:
1945 		break;
1946 	default:
1947 		close(fd);
1948 		return pid;
1949 	}
1950 
1951 	if (fd != GOTD_SOCK_FILENO) {
1952 		if (dup2(fd, GOTD_SOCK_FILENO) == -1)
1953 			fatal("cannot setup imsg fd");
1954 	} else if (fcntl(fd, F_SETFD, 0) == -1)
1955 		fatal("cannot setup imsg fd");
1956 
1957 	argv[argc++] = argv0;
1958 	switch (proc_id) {
1959 	case PROC_REPO_READ:
1960 		argv[argc++] = (char *)"-R";
1961 		break;
1962 	case PROC_REPO_WRITE:
1963 		argv[argc++] = (char *)"-W";
1964 		break;
1965 	default:
1966 		fatalx("invalid process id %d", proc_id);
1967 	}
1968 
1969 	argv[argc++] = (char *)"-f";
1970 	argv[argc++] = (char *)confpath;
1971 
1972 	argv[argc++] = (char *)"-P";
1973 	argv[argc++] = (char *)chroot_path;
1974 
1975 	if (!daemonize)
1976 		argv[argc++] = (char *)"-d";
1977 	if (verbosity > 0)
1978 		argv[argc++] = (char *)"-v";
1979 	if (verbosity > 1)
1980 		argv[argc++] = (char *)"-v";
1981 	argv[argc++] = NULL;
1982 
1983 	execvp(argv0, argv);
1984 	fatal("execvp");
1985 }
1986 
1987 static void
1988 start_repo_children(struct gotd *gotd, char *argv0, const char *confpath,
1989     int daemonize, int verbosity)
1990 {
1991 	struct gotd_repo *repo = NULL;
1992 	struct gotd_child_proc *proc;
1993 	int i;
1994 
1995 	/*
1996 	 * XXX For now, use one reader and one writer per repository.
1997 	 * This should be changed to N readers + M writers.
1998 	 */
1999 	gotd->nprocs = gotd->nrepos * 2;
2000 	gotd->procs = calloc(gotd->nprocs, sizeof(*gotd->procs));
2001 	if (gotd->procs == NULL)
2002 		fatal("calloc");
2003 	for (i = 0; i < gotd->nprocs; i++) {
2004 		if (repo == NULL)
2005 			repo = TAILQ_FIRST(&gotd->repos);
2006 		proc = &gotd->procs[i];
2007 		if (i < gotd->nrepos)
2008 			proc->type = PROC_REPO_READ;
2009 		else
2010 			proc->type = PROC_REPO_WRITE;
2011 		if (strlcpy(proc->repo_name, repo->name,
2012 		    sizeof(proc->repo_name)) >= sizeof(proc->repo_name))
2013 			fatalx("repository name too long: %s", repo->name);
2014 		log_debug("adding repository %s", repo->name);
2015 		if (realpath(repo->path, proc->chroot_path) == NULL)
2016 			fatal("%s", repo->path);
2017 		if (socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK,
2018 		    PF_UNSPEC, proc->pipe) == -1)
2019 			fatal("socketpair");
2020 		proc->pid = start_child(proc->type, proc->chroot_path, argv0,
2021 		    confpath, proc->pipe[1], daemonize, verbosity);
2022 		imsg_init(&proc->iev.ibuf, proc->pipe[0]);
2023 		log_debug("proc %s %s is on fd %d",
2024 		    gotd_proc_names[proc->type], proc->chroot_path,
2025 		    proc->pipe[0]);
2026 		proc->iev.handler = gotd_dispatch;
2027 		proc->iev.events = EV_READ;
2028 		proc->iev.handler_arg = NULL;
2029 		event_set(&proc->iev.ev, proc->iev.ibuf.fd, EV_READ,
2030 		    gotd_dispatch, &proc->iev);
2031 
2032 		repo = TAILQ_NEXT(repo, entry);
2033 	}
2034 }
2035 
2036 static void
2037 apply_unveil(void)
2038 {
2039 	struct gotd_repo *repo;
2040 
2041 	TAILQ_FOREACH(repo, &gotd.repos, entry) {
2042 		if (unveil(repo->path, "rwc") == -1)
2043 			fatal("unveil %s", repo->path);
2044 	}
2045 
2046 	if (unveil(GOT_TMPDIR_STR, "rwc") == -1)
2047 		fatal("unveil %s", GOT_TMPDIR_STR);
2048 
2049 	if (unveil(NULL, NULL) == -1)
2050 		fatal("unveil");
2051 }
2052 
2053 int
2054 main(int argc, char **argv)
2055 {
2056 	const struct got_error *error = NULL;
2057 	int ch, fd = -1, daemonize = 1, verbosity = 0, noaction = 0;
2058 	const char *confpath = GOTD_CONF_PATH;
2059 	char *argv0 = argv[0];
2060 	char title[2048];
2061 	gid_t groups[NGROUPS_MAX + 1];
2062 	int ngroups = NGROUPS_MAX + 1;
2063 	struct passwd *pw = NULL;
2064 	struct group *gr = NULL;
2065 	char *repo_path = NULL;
2066 	enum gotd_procid proc_id = PROC_GOTD;
2067 	struct event evsigint, evsigterm, evsighup, evsigusr1;
2068 	int *pack_fds = NULL, *temp_fds = NULL;
2069 
2070 	log_init(1, LOG_DAEMON); /* Log to stderr until daemonized. */
2071 
2072 	while ((ch = getopt(argc, argv, "df:nP:RvW")) != -1) {
2073 		switch (ch) {
2074 		case 'd':
2075 			daemonize = 0;
2076 			break;
2077 		case 'f':
2078 			confpath = optarg;
2079 			break;
2080 		case 'n':
2081 			noaction = 1;
2082 			break;
2083 		case 'P':
2084 			repo_path = realpath(optarg, NULL);
2085 			if (repo_path == NULL)
2086 				fatal("realpath '%s'", optarg);
2087 			break;
2088 		case 'R':
2089 			proc_id = PROC_REPO_READ;
2090 			break;
2091 		case 'v':
2092 			if (verbosity < 3)
2093 				verbosity++;
2094 			break;
2095 		case 'W':
2096 			proc_id = PROC_REPO_WRITE;
2097 			break;
2098 		default:
2099 			usage();
2100 		}
2101 	}
2102 
2103 	argc -= optind;
2104 	argv += optind;
2105 
2106 	if (argc != 0)
2107 		usage();
2108 
2109 	if (geteuid())
2110 		fatalx("need root privileges");
2111 
2112 	log_init(daemonize ? 0 : 1, LOG_DAEMON);
2113 	log_setverbose(verbosity);
2114 
2115 	if (parse_config(confpath, proc_id, &gotd) != 0)
2116 		return 1;
2117 
2118 	if (proc_id == PROC_GOTD &&
2119 	    (gotd.nrepos == 0 || TAILQ_EMPTY(&gotd.repos)))
2120 		fatalx("no repository defined in configuration file");
2121 
2122 	pw = getpwnam(gotd.user_name);
2123 	if (pw == NULL)
2124 		fatal("getpwuid: user %s not found", gotd.user_name);
2125 
2126 	if (pw->pw_uid == 0) {
2127 		fatalx("cannot run %s as %s: the user running %s "
2128 		    "must not be the superuser",
2129 		    getprogname(), pw->pw_name, getprogname());
2130 	}
2131 
2132 	if (getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups) == -1)
2133 		log_warnx("group membership list truncated");
2134 
2135 	gr = match_group(groups, ngroups, gotd.unix_group_name);
2136 	if (gr == NULL) {
2137 		fatalx("cannot start %s: the user running %s "
2138 		    "must be a secondary member of group %s",
2139 		    getprogname(), getprogname(), gotd.unix_group_name);
2140 	}
2141 	if (gr->gr_gid == pw->pw_gid) {
2142 		fatalx("cannot start %s: the user running %s "
2143 		    "must be a secondary member of group %s, but "
2144 		    "%s is the user's primary group",
2145 		    getprogname(), getprogname(), gotd.unix_group_name,
2146 		    gotd.unix_group_name);
2147 	}
2148 
2149 	if (proc_id == PROC_GOTD &&
2150 	    !got_path_is_absolute(gotd.unix_socket_path))
2151 		fatalx("bad unix socket path \"%s\": must be an absolute path",
2152 		    gotd.unix_socket_path);
2153 
2154 	if (noaction)
2155 		return 0;
2156 
2157 	if (proc_id == PROC_GOTD && verbosity) {
2158 		log_info("socket: %s", gotd.unix_socket_path);
2159 		log_info("user: %s", pw->pw_name);
2160 		log_info("secondary group: %s", gr->gr_name);
2161 
2162 		fd = unix_socket_listen(gotd.unix_socket_path, pw->pw_uid,
2163 		    gr->gr_gid);
2164 		if (fd == -1) {
2165 			fatal("cannot listen on unix socket %s",
2166 			    gotd.unix_socket_path);
2167 		}
2168 	}
2169 
2170 	if (proc_id == PROC_GOTD) {
2171 		gotd.pid = getpid();
2172 		snprintf(title, sizeof(title), "%s", gotd_proc_names[proc_id]);
2173 		start_repo_children(&gotd, argv0, confpath, daemonize,
2174 		    verbosity);
2175 		arc4random_buf(&clients_hash_key, sizeof(clients_hash_key));
2176 		if (daemonize && daemon(0, 0) == -1)
2177 			fatal("daemon");
2178 	} else if (proc_id == PROC_REPO_READ || proc_id == PROC_REPO_WRITE) {
2179 		error = got_repo_pack_fds_open(&pack_fds);
2180 		if (error != NULL)
2181 			fatalx("cannot open pack tempfiles: %s", error->msg);
2182 		error = got_repo_temp_fds_open(&temp_fds);
2183 		if (error != NULL)
2184 			fatalx("cannot open pack tempfiles: %s", error->msg);
2185 		if (repo_path == NULL)
2186 			fatalx("repository path not specified");
2187 		snprintf(title, sizeof(title), "%s %s",
2188 		    gotd_proc_names[proc_id], repo_path);
2189 		if (chroot(repo_path) == -1)
2190 			fatal("chroot");
2191 		if (chdir("/") == -1)
2192 			fatal("chdir(\"/\")");
2193 		if (daemonize && daemon(1, 0) == -1)
2194 			fatal("daemon");
2195 	} else
2196 		fatal("invalid process id %d", proc_id);
2197 
2198 	setproctitle("%s", title);
2199 	log_procinit(title);
2200 
2201 	/* Drop root privileges. */
2202 	if (setgid(pw->pw_gid) == -1)
2203 		fatal("setgid %d failed", pw->pw_gid);
2204 	if (setuid(pw->pw_uid) == -1)
2205 		fatal("setuid %d failed", pw->pw_uid);
2206 
2207 	event_init();
2208 
2209 	switch (proc_id) {
2210 	case PROC_GOTD:
2211 #ifndef PROFILE
2212 		if (pledge("stdio rpath wpath cpath proc getpw sendfd recvfd "
2213 		    "fattr flock unix unveil", NULL) == -1)
2214 			err(1, "pledge");
2215 #endif
2216 		break;
2217 	case PROC_REPO_READ:
2218 #ifndef PROFILE
2219 		if (pledge("stdio rpath recvfd", NULL) == -1)
2220 			err(1, "pledge");
2221 #endif
2222 		repo_read_main(title, pack_fds, temp_fds);
2223 		/* NOTREACHED */
2224 		exit(0);
2225 	case PROC_REPO_WRITE:
2226 #ifndef PROFILE
2227 		if (pledge("stdio rpath recvfd", NULL) == -1)
2228 			err(1, "pledge");
2229 #endif
2230 		repo_write_main(title, pack_fds, temp_fds);
2231 		/* NOTREACHED */
2232 		exit(0);
2233 	default:
2234 		fatal("invalid process id %d", proc_id);
2235 	}
2236 
2237 	if (proc_id != PROC_GOTD)
2238 		fatal("invalid process id %d", proc_id);
2239 
2240 	apply_unveil();
2241 
2242 	signal_set(&evsigint, SIGINT, gotd_sighdlr, NULL);
2243 	signal_set(&evsigterm, SIGTERM, gotd_sighdlr, NULL);
2244 	signal_set(&evsighup, SIGHUP, gotd_sighdlr, NULL);
2245 	signal_set(&evsigusr1, SIGUSR1, gotd_sighdlr, NULL);
2246 	signal(SIGPIPE, SIG_IGN);
2247 
2248 	signal_add(&evsigint, NULL);
2249 	signal_add(&evsigterm, NULL);
2250 	signal_add(&evsighup, NULL);
2251 	signal_add(&evsigusr1, NULL);
2252 
2253 	event_set(&gotd.ev, fd, EV_READ | EV_PERSIST, gotd_accept, NULL);
2254 	if (event_add(&gotd.ev, NULL))
2255 		fatalx("event add");
2256 	evtimer_set(&gotd.pause, gotd_accept_paused, NULL);
2257 
2258 	event_dispatch();
2259 
2260 	if (fd != -1)
2261 		close(fd);
2262 	if (pack_fds)
2263 		got_repo_pack_fds_close(pack_fds);
2264 	free(repo_path);
2265 	return 0;
2266 }