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portable: gotd: listen
[got-portable.git] / gotd / gotd.c
blob9ed19e79b8bd0a7e69cf184b6a0bb5abfaa87fc3
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/time.h>
19 #include <sys/types.h>
20 #include <sys/stat.h>
21 #include <sys/socket.h>
22 #include <sys/un.h>
23 #include <sys/wait.h>
24
25 #include <fcntl.h>
26 #include <err.h>
27 #include <errno.h>
28 #include <event.h>
29 #include <limits.h>
30 #include <pwd.h>
31 #include <imsg.h>
32 #include <signal.h>
33 #include <stdarg.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <syslog.h>
38 #include <unistd.h>
39
40 #include "got_error.h"
41 #include "got_opentemp.h"
42 #include "got_path.h"
43 #include "got_repository.h"
44 #include "got_object.h"
45 #include "got_reference.h"
46
47 #include "got_lib_delta.h"
48 #include "got_lib_object.h"
49 #include "got_lib_object_cache.h"
50 #include "got_lib_hash.h"
51 #include "got_lib_gitproto.h"
52 #include "got_lib_pack.h"
53 #include "got_lib_repository.h"
54
55 #include "gotd.h"
56 #include "log.h"
57 #include "listen.h"
58 #include "auth.h"
59 #include "session.h"
60 #include "repo_read.h"
61 #include "repo_write.h"
62
63 #ifndef nitems
64 #define nitems(_a) (sizeof((_a)) / sizeof((_a)[0]))
65 #endif
66
67 enum gotd_client_state {
68 GOTD_CLIENT_STATE_NEW,
69 GOTD_CLIENT_STATE_ACCESS_GRANTED,
70 };
71
72 struct gotd_child_proc {
73 pid_t pid;
74 enum gotd_procid type;
75 char repo_name[NAME_MAX];
76 char repo_path[PATH_MAX];
77 int pipe[2];
78 struct gotd_imsgev iev;
79 struct event tmo;
80
81 TAILQ_ENTRY(gotd_child_proc) entry;
82 };
83 TAILQ_HEAD(gotd_procs, gotd_child_proc) procs;
84
85 struct gotd_client {
86 STAILQ_ENTRY(gotd_client) entry;
87 enum gotd_client_state state;
88 uint32_t id;
89 int fd;
90 struct gotd_imsgev iev;
91 struct event tmo;
92 uid_t euid;
93 gid_t egid;
94 struct gotd_child_proc *repo;
95 struct gotd_child_proc *auth;
96 struct gotd_child_proc *session;
97 int required_auth;
98 };
99 STAILQ_HEAD(gotd_clients, gotd_client);
100
101 static struct gotd_clients gotd_clients[GOTD_CLIENT_TABLE_SIZE];
102 static SIPHASH_KEY clients_hash_key;
103 volatile int client_cnt;
104 static struct timeval auth_timeout = { 5, 0 };
105 static struct gotd gotd;
106
107 void gotd_sighdlr(int sig, short event, void *arg);
108 static void gotd_shutdown(void);
109 static const struct got_error *start_session_child(struct gotd_client *,
110 struct gotd_repo *, char *, const char *, int, int);
111 static const struct got_error *start_repo_child(struct gotd_client *,
112 enum gotd_procid, struct gotd_repo *, char *, const char *, int, int);
113 static const struct got_error *start_auth_child(struct gotd_client *, int,
114 struct gotd_repo *, char *, const char *, int, int);
115 static void kill_proc(struct gotd_child_proc *, int);
116 static void disconnect(struct gotd_client *);
117
118 __dead static void
119 usage(void)
120 {
121 fprintf(stderr, "usage: %s [-dnv] [-f config-file]\n", getprogname());
122 exit(1);
123 }
124
125 static int
126 unix_socket_listen(const char *unix_socket_path, uid_t uid, gid_t gid)
127 {
128 struct sockaddr_un sun;
129 int fd = -1;
130 mode_t old_umask, mode;
131 int sock_flags = SOCK_STREAM | SOCK_NONBLOCK;
132
133 #ifdef SOCK_CLOEXEC
134 sock_flags |= SOCK_CLOEXEC;
135 #endif
136
137 fd = socket(AF_UNIX, sock_flags, 0);
138 if (fd == -1) {
139 log_warn("socket");
140 return -1;
141 }
142
143 sun.sun_family = AF_UNIX;
144 if (strlcpy(sun.sun_path, unix_socket_path,
145 sizeof(sun.sun_path)) >= sizeof(sun.sun_path)) {
146 log_warnx("%s: name too long", unix_socket_path);
147 close(fd);
148 return -1;
149 }
150
151 if (unlink(unix_socket_path) == -1) {
152 if (errno != ENOENT) {
153 log_warn("unlink %s", unix_socket_path);
154 close(fd);
155 return -1;
156 }
157 }
158
159 old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);
160 mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH;
161
162 if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
163 log_warn("bind: %s", unix_socket_path);
164 close(fd);
165 umask(old_umask);
166 return -1;
167 }
168
169 umask(old_umask);
170
171 if (chmod(unix_socket_path, mode) == -1) {
172 log_warn("chmod %o %s", mode, unix_socket_path);
173 close(fd);
174 unlink(unix_socket_path);
175 return -1;
176 }
177
178 if (chown(unix_socket_path, uid, gid) == -1) {
179 log_warn("chown %s uid=%d gid=%d", unix_socket_path, uid, gid);
180 close(fd);
181 unlink(unix_socket_path);
182 return -1;
183 }
184
185 if (listen(fd, GOTD_UNIX_SOCKET_BACKLOG) == -1) {
186 log_warn("listen");
187 close(fd);
188 unlink(unix_socket_path);
189 return -1;
190 }
191
192 return fd;
193 }
194
195 static uint64_t
196 client_hash(uint32_t client_id)
197 {
198 return SipHash24(&clients_hash_key, &client_id, sizeof(client_id));
199 }
200
201 static void
202 add_client(struct gotd_client *client)
203 {
204 uint64_t slot = client_hash(client->id) % nitems(gotd_clients);
205 STAILQ_INSERT_HEAD(&gotd_clients[slot], client, entry);
206 client_cnt++;
207 }
208
209 static struct gotd_client *
210 find_client(uint32_t client_id)
211 {
212 uint64_t slot;
213 struct gotd_client *c;
214
215 slot = client_hash(client_id) % nitems(gotd_clients);
216 STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
217 if (c->id == client_id)
218 return c;
219 }
220
221 return NULL;
222 }
223
224 static struct gotd_client *
225 find_client_by_proc_fd(int fd)
226 {
227 uint64_t slot;
228
229 for (slot = 0; slot < nitems(gotd_clients); slot++) {
230 struct gotd_client *c;
231
232 STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
233 if (c->repo && c->repo->iev.ibuf.fd == fd)
234 return c;
235 if (c->auth && c->auth->iev.ibuf.fd == fd)
236 return c;
237 if (c->session && c->session->iev.ibuf.fd == fd)
238 return c;
239 }
240 }
241
242 return NULL;
243 }
244
245 static int
246 client_is_reading(struct gotd_client *client)
247 {
248 return (client->required_auth &
249 (GOTD_AUTH_READ | GOTD_AUTH_WRITE)) == GOTD_AUTH_READ;
250 }
251
252 static int
253 client_is_writing(struct gotd_client *client)
254 {
255 return (client->required_auth &
256 (GOTD_AUTH_READ | GOTD_AUTH_WRITE)) ==
257 (GOTD_AUTH_READ | GOTD_AUTH_WRITE);
258 }
259
260 static const struct got_error *
261 ensure_client_is_not_writing(struct gotd_client *client)
262 {
263 if (client_is_writing(client)) {
264 return got_error_fmt(GOT_ERR_BAD_PACKET,
265 "uid %d made a read-request but is writing to "
266 "a repository", client->euid);
267 }
268
269 return NULL;
270 }
271
272 static const struct got_error *
273 ensure_client_is_not_reading(struct gotd_client *client)
274 {
275 if (client_is_reading(client)) {
276 return got_error_fmt(GOT_ERR_BAD_PACKET,
277 "uid %d made a write-request but is reading from "
278 "a repository", client->euid);
279 }
280
281 return NULL;
282 }
283
284 static void
285 proc_done(struct gotd_child_proc *proc)
286 {
287 struct gotd_client *client;
288
289 TAILQ_REMOVE(&procs, proc, entry);
290
291 client = find_client_by_proc_fd(proc->iev.ibuf.fd);
292 if (client != NULL) {
293 if (proc == client->repo)
294 client->repo = NULL;
295 if (proc == client->auth)
296 client->auth = NULL;
297 if (proc == client->session)
298 client->session = NULL;
299 disconnect(client);
300 }
301
302 evtimer_del(&proc->tmo);
303
304 if (proc->iev.ibuf.fd != -1) {
305 event_del(&proc->iev.ev);
306 msgbuf_clear(&proc->iev.ibuf.w);
307 close(proc->iev.ibuf.fd);
308 }
309
310 free(proc);
311 }
312
313 static void
314 kill_repo_proc(struct gotd_client *client)
315 {
316 if (client->repo == NULL)
317 return;
318
319 kill_proc(client->repo, 0);
320 client->repo = NULL;
321 }
322
323 static void
324 kill_auth_proc(struct gotd_client *client)
325 {
326 if (client->auth == NULL)
327 return;
328
329 kill_proc(client->auth, 0);
330 client->auth = NULL;
331 }
332
333 static void
334 kill_session_proc(struct gotd_client *client)
335 {
336 if (client->session == NULL)
337 return;
338
339 kill_proc(client->session, 0);
340 client->session = NULL;
341 }
342
343 static void
344 disconnect(struct gotd_client *client)
345 {
346 struct gotd_imsg_disconnect idisconnect;
347 struct gotd_child_proc *listen_proc = gotd.listen_proc;
348 uint64_t slot;
349
350 log_debug("uid %d: disconnecting", client->euid);
351
352 kill_auth_proc(client);
353 kill_session_proc(client);
354 kill_repo_proc(client);
355
356 idisconnect.client_id = client->id;
357 if (gotd_imsg_compose_event(&listen_proc->iev,
358 GOTD_IMSG_DISCONNECT, PROC_GOTD, -1,
359 &idisconnect, sizeof(idisconnect)) == -1)
360 log_warn("imsg compose DISCONNECT");
361
362 slot = client_hash(client->id) % nitems(gotd_clients);
363 STAILQ_REMOVE(&gotd_clients[slot], client, gotd_client, entry);
364 imsg_clear(&client->iev.ibuf);
365 event_del(&client->iev.ev);
366 evtimer_del(&client->tmo);
367 if (client->fd != -1)
368 close(client->fd);
369 else if (client->iev.ibuf.fd != -1)
370 close(client->iev.ibuf.fd);
371 free(client);
372 client_cnt--;
373 }
374
375 static void
376 disconnect_on_error(struct gotd_client *client, const struct got_error *err)
377 {
378 struct imsgbuf ibuf;
379
380 if (err->code != GOT_ERR_EOF) {
381 log_warnx("uid %d: %s", client->euid, err->msg);
382 if (client->fd != -1) {
383 imsg_init(&ibuf, client->fd);
384 gotd_imsg_send_error(&ibuf, 0, PROC_GOTD, err);
385 imsg_clear(&ibuf);
386 }
387 }
388 disconnect(client);
389 }
390
391 static const struct got_error *
392 send_repo_info(struct gotd_imsgev *iev, struct gotd_repo *repo)
393 {
394 const struct got_error *err = NULL;
395 struct gotd_imsg_info_repo irepo;
396
397 memset(&irepo, 0, sizeof(irepo));
398
399 if (strlcpy(irepo.repo_name, repo->name, sizeof(irepo.repo_name))
400 >= sizeof(irepo.repo_name))
401 return got_error_msg(GOT_ERR_NO_SPACE, "repo name too long");
402 if (strlcpy(irepo.repo_path, repo->path, sizeof(irepo.repo_path))
403 >= sizeof(irepo.repo_path))
404 return got_error_msg(GOT_ERR_NO_SPACE, "repo path too long");
405
406 if (gotd_imsg_compose_event(iev, GOTD_IMSG_INFO_REPO, PROC_GOTD, -1,
407 &irepo, sizeof(irepo)) == -1) {
408 err = got_error_from_errno("imsg compose INFO_REPO");
409 if (err)
410 return err;
411 }
412
413 return NULL;
414 }
415
416 static const struct got_error *
417 send_client_info(struct gotd_imsgev *iev, struct gotd_client *client)
418 {
419 const struct got_error *err = NULL;
420 struct gotd_imsg_info_client iclient;
421 struct gotd_child_proc *proc;
422
423 memset(&iclient, 0, sizeof(iclient));
424 iclient.euid = client->euid;
425 iclient.egid = client->egid;
426
427 proc = client->repo;
428 if (proc) {
429 if (strlcpy(iclient.repo_name, proc->repo_path,
430 sizeof(iclient.repo_name)) >= sizeof(iclient.repo_name)) {
431 return got_error_msg(GOT_ERR_NO_SPACE,
432 "repo name too long");
433 }
434 if (client_is_writing(client))
435 iclient.is_writing = 1;
436
437 iclient.repo_child_pid = proc->pid;
438 }
439
440 if (client->session)
441 iclient.session_child_pid = client->session->pid;
442
443 if (gotd_imsg_compose_event(iev, GOTD_IMSG_INFO_CLIENT, PROC_GOTD, -1,
444 &iclient, sizeof(iclient)) == -1) {
445 err = got_error_from_errno("imsg compose INFO_CLIENT");
446 if (err)
447 return err;
448 }
449
450 return NULL;
451 }
452
453 static const struct got_error *
454 send_info(struct gotd_client *client)
455 {
456 const struct got_error *err = NULL;
457 struct gotd_imsg_info info;
458 uint64_t slot;
459 struct gotd_repo *repo;
460
461 if (client->euid != 0)
462 return got_error_set_errno(EPERM, "info");
463
464 info.pid = gotd.pid;
465 info.verbosity = gotd.verbosity;
466 info.nrepos = gotd.nrepos;
467 info.nclients = client_cnt - 1;
468
469 if (gotd_imsg_compose_event(&client->iev, GOTD_IMSG_INFO, PROC_GOTD, -1,
470 &info, sizeof(info)) == -1) {
471 err = got_error_from_errno("imsg compose INFO");
472 if (err)
473 return err;
474 }
475
476 TAILQ_FOREACH(repo, &gotd.repos, entry) {
477 err = send_repo_info(&client->iev, repo);
478 if (err)
479 return err;
480 }
481
482 for (slot = 0; slot < nitems(gotd_clients); slot++) {
483 struct gotd_client *c;
484 STAILQ_FOREACH(c, &gotd_clients[slot], entry) {
485 if (c->id == client->id)
486 continue;
487 err = send_client_info(&client->iev, c);
488 if (err)
489 return err;
490 }
491 }
492
493 return NULL;
494 }
495
496 static const struct got_error *
497 stop_gotd(struct gotd_client *client)
498 {
499
500 if (client->euid != 0)
501 return got_error_set_errno(EPERM, "stop");
502
503 gotd_shutdown();
504 /* NOTREACHED */
505 return NULL;
506 }
507
508 static const struct got_error *
509 start_client_authentication(struct gotd_client *client, struct imsg *imsg)
510 {
511 const struct got_error *err;
512 struct gotd_imsg_list_refs ireq;
513 struct gotd_repo *repo = NULL;
514 size_t datalen;
515
516 log_debug("list-refs request from uid %d", client->euid);
517
518 if (client->state != GOTD_CLIENT_STATE_NEW)
519 return got_error_msg(GOT_ERR_BAD_REQUEST,
520 "unexpected list-refs request received");
521
522 datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
523 if (datalen != sizeof(ireq))
524 return got_error(GOT_ERR_PRIVSEP_LEN);
525
526 memcpy(&ireq, imsg->data, datalen);
527
528 if (ireq.client_is_reading) {
529 err = ensure_client_is_not_writing(client);
530 if (err)
531 return err;
532 repo = gotd_find_repo_by_name(ireq.repo_name, &gotd);
533 if (repo == NULL)
534 return got_error(GOT_ERR_NOT_GIT_REPO);
535 err = start_auth_child(client, GOTD_AUTH_READ, repo,
536 gotd.argv0, gotd.confpath, gotd.daemonize,
537 gotd.verbosity);
538 if (err)
539 return err;
540 } else {
541 err = ensure_client_is_not_reading(client);
542 if (err)
543 return err;
544 repo = gotd_find_repo_by_name(ireq.repo_name, &gotd);
545 if (repo == NULL)
546 return got_error(GOT_ERR_NOT_GIT_REPO);
547 err = start_auth_child(client,
548 GOTD_AUTH_READ | GOTD_AUTH_WRITE,
549 repo, gotd.argv0, gotd.confpath, gotd.daemonize,
550 gotd.verbosity);
551 if (err)
552 return err;
553 }
554
555 evtimer_add(&client->tmo, &auth_timeout);
556
557 /* Flow continues upon authentication success/failure or timeout. */
558 return NULL;
559 }
560
561 static void
562 gotd_request(int fd, short events, void *arg)
563 {
564 struct gotd_imsgev *iev = arg;
565 struct imsgbuf *ibuf = &iev->ibuf;
566 struct gotd_client *client = iev->handler_arg;
567 const struct got_error *err = NULL;
568 struct imsg imsg;
569 ssize_t n;
570
571 if (events & EV_WRITE) {
572 while (ibuf->w.queued) {
573 n = msgbuf_write(&ibuf->w);
574 if (n == -1 && errno == EPIPE) {
575 /*
576 * The client has closed its socket.
577 * This can happen when Git clients are
578 * done sending pack file data.
579 */
580 msgbuf_clear(&ibuf->w);
581 continue;
582 } else if (n == -1 && errno != EAGAIN) {
583 err = got_error_from_errno("imsg_flush");
584 disconnect_on_error(client, err);
585 return;
586 }
587 if (n == 0) {
588 /* Connection closed. */
589 err = got_error(GOT_ERR_EOF);
590 disconnect_on_error(client, err);
591 return;
592 }
593 }
594
595 /* Disconnect gotctl(8) now that messages have been sent. */
596 if (!client_is_reading(client) && !client_is_writing(client)) {
597 disconnect(client);
598 return;
599 }
600 }
601
602 if ((events & EV_READ) == 0)
603 return;
604
605 memset(&imsg, 0, sizeof(imsg));
606
607 while (err == NULL) {
608 err = gotd_imsg_recv(&imsg, ibuf, 0);
609 if (err) {
610 if (err->code == GOT_ERR_PRIVSEP_READ)
611 err = NULL;
612 break;
613 }
614
615 evtimer_del(&client->tmo);
616
617 switch (imsg.hdr.type) {
618 case GOTD_IMSG_INFO:
619 err = send_info(client);
620 break;
621 case GOTD_IMSG_STOP:
622 err = stop_gotd(client);
623 break;
624 case GOTD_IMSG_LIST_REFS:
625 err = start_client_authentication(client, &imsg);
626 break;
627 default:
628 log_debug("unexpected imsg %d", imsg.hdr.type);
629 err = got_error(GOT_ERR_PRIVSEP_MSG);
630 break;
631 }
632
633 imsg_free(&imsg);
634 }
635
636 if (err) {
637 disconnect_on_error(client, err);
638 } else {
639 gotd_imsg_event_add(&client->iev);
640 }
641 }
642
643 static void
644 gotd_auth_timeout(int fd, short events, void *arg)
645 {
646 struct gotd_client *client = arg;
647
648 log_debug("disconnecting uid %d due to authentication timeout",
649 client->euid);
650 disconnect(client);
651 }
652
653 static const struct got_error *
654 recv_connect(uint32_t *client_id, struct imsg *imsg)
655 {
656 const struct got_error *err = NULL;
657 struct gotd_imsg_connect iconnect;
658 size_t datalen;
659 int s = -1;
660 struct gotd_client *client = NULL;
661
662 *client_id = 0;
663
664 datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
665 if (datalen != sizeof(iconnect))
666 return got_error(GOT_ERR_PRIVSEP_LEN);
667 memcpy(&iconnect, imsg->data, sizeof(iconnect));
668
669 s = imsg->fd;
670 if (s == -1) {
671 err = got_error(GOT_ERR_PRIVSEP_NO_FD);
672 goto done;
673 }
674
675 if (find_client(iconnect.client_id)) {
676 err = got_error_msg(GOT_ERR_CLIENT_ID, "duplicate client ID");
677 goto done;
678 }
679
680 client = calloc(1, sizeof(*client));
681 if (client == NULL) {
682 err = got_error_from_errno("calloc");
683 goto done;
684 }
685
686 *client_id = iconnect.client_id;
687
688 client->state = GOTD_CLIENT_STATE_NEW;
689 client->id = iconnect.client_id;
690 client->fd = s;
691 s = -1;
692 /* The auth process will verify UID/GID for us. */
693 client->euid = iconnect.euid;
694 client->egid = iconnect.egid;
695
696 imsg_init(&client->iev.ibuf, client->fd);
697 client->iev.handler = gotd_request;
698 client->iev.events = EV_READ;
699 client->iev.handler_arg = client;
700
701 event_set(&client->iev.ev, client->fd, EV_READ, gotd_request,
702 &client->iev);
703 gotd_imsg_event_add(&client->iev);
704
705 evtimer_set(&client->tmo, gotd_auth_timeout, client);
706
707 add_client(client);
708 log_debug("%s: new client uid %d connected on fd %d", __func__,
709 client->euid, client->fd);
710 done:
711 if (err) {
712 struct gotd_child_proc *listen_proc = gotd.listen_proc;
713 struct gotd_imsg_disconnect idisconnect;
714
715 idisconnect.client_id = client->id;
716 if (gotd_imsg_compose_event(&listen_proc->iev,
717 GOTD_IMSG_DISCONNECT, PROC_GOTD, -1,
718 &idisconnect, sizeof(idisconnect)) == -1)
719 log_warn("imsg compose DISCONNECT");
720
721 if (s != -1)
722 close(s);
723 }
724
725 return err;
726 }
727
728 static const char *gotd_proc_names[PROC_MAX] = {
729 "parent",
730 "listen",
731 "auth",
732 "session_read",
733 "session_write",
734 "repo_read",
735 "repo_write",
736 "gitwrapper"
737 };
738
739 static void
740 kill_proc(struct gotd_child_proc *proc, int fatal)
741 {
742 struct timeval tv = { 5, 0 };
743
744 log_debug("kill -%d %d", fatal ? SIGKILL : SIGTERM, proc->pid);
745
746 if (proc->iev.ibuf.fd != -1) {
747 event_del(&proc->iev.ev);
748 msgbuf_clear(&proc->iev.ibuf.w);
749 close(proc->iev.ibuf.fd);
750 proc->iev.ibuf.fd = -1;
751 }
752
753 if (!evtimer_pending(&proc->tmo, NULL) && !fatal)
754 evtimer_add(&proc->tmo, &tv);
755
756 if (fatal) {
757 log_warnx("sending SIGKILL to PID %d", proc->pid);
758 kill(proc->pid, SIGKILL);
759 } else
760 kill(proc->pid, SIGTERM);
761 }
762
763 static void
764 kill_proc_timeout(int fd, short ev, void *d)
765 {
766 struct gotd_child_proc *proc = d;
767
768 log_warnx("timeout waiting for PID %d to terminate;"
769 " retrying with force", proc->pid);
770 kill_proc(proc, 1);
771 }
772
773 static void
774 gotd_shutdown(void)
775 {
776 uint64_t slot;
777
778 log_debug("shutting down");
779 for (slot = 0; slot < nitems(gotd_clients); slot++) {
780 struct gotd_client *c, *tmp;
781
782 STAILQ_FOREACH_SAFE(c, &gotd_clients[slot], entry, tmp)
783 disconnect(c);
784 }
785
786 kill_proc(gotd.listen_proc, 0);
787
788 log_info("terminating");
789 exit(0);
790 }
791
792 static struct gotd_child_proc *
793 find_proc_by_pid(pid_t pid)
794 {
795 struct gotd_child_proc *proc = NULL;
796
797 TAILQ_FOREACH(proc, &procs, entry)
798 if (proc->pid == pid)
799 break;
800
801 return proc;
802 }
803
804 void
805 gotd_sighdlr(int sig, short event, void *arg)
806 {
807 struct gotd_child_proc *proc;
808 pid_t pid;
809 int status;
810
811 /*
812 * Normal signal handler rules don't apply because libevent
813 * decouples for us.
814 */
815
816 switch (sig) {
817 case SIGHUP:
818 log_info("%s: ignoring SIGHUP", __func__);
819 break;
820 case SIGUSR1:
821 log_info("%s: ignoring SIGUSR1", __func__);
822 break;
823 case SIGTERM:
824 case SIGINT:
825 gotd_shutdown();
826 break;
827 case SIGCHLD:
828 for (;;) {
829 pid = waitpid(WAIT_ANY, &status, WNOHANG);
830 if (pid == -1) {
831 if (errno == EINTR)
832 continue;
833 if (errno == ECHILD)
834 break;
835 fatal("waitpid");
836 }
837 if (pid == 0)
838 break;
839
840 log_debug("reaped pid %d", pid);
841 proc = find_proc_by_pid(pid);
842 if (proc == NULL) {
843 log_info("caught exit of unknown child %d",
844 pid);
845 continue;
846 }
847
848 if (WIFSIGNALED(status)) {
849 log_warnx("child PID %d terminated with"
850 " signal %d", pid, WTERMSIG(status));
851 }
852
853 proc_done(proc);
854 }
855 break;
856 default:
857 fatalx("unexpected signal");
858 }
859 }
860
861 static const struct got_error *
862 ensure_proc_is_reading(struct gotd_client *client,
863 struct gotd_child_proc *proc)
864 {
865 if (!client_is_reading(client)) {
866 kill_proc(proc, 1);
867 return got_error_fmt(GOT_ERR_BAD_PACKET,
868 "PID %d handled a read-request for uid %d but this "
869 "user is not reading from a repository", proc->pid,
870 client->euid);
871 }
872
873 return NULL;
874 }
875
876 static const struct got_error *
877 ensure_proc_is_writing(struct gotd_client *client,
878 struct gotd_child_proc *proc)
879 {
880 if (!client_is_writing(client)) {
881 kill_proc(proc, 1);
882 return got_error_fmt(GOT_ERR_BAD_PACKET,
883 "PID %d handled a write-request for uid %d but this "
884 "user is not writing to a repository", proc->pid,
885 client->euid);
886 }
887
888 return NULL;
889 }
890
891 static int
892 verify_imsg_src(struct gotd_client *client, struct gotd_child_proc *proc,
893 struct imsg *imsg)
894 {
895 const struct got_error *err;
896 int ret = 0;
897
898 if (proc->type == PROC_REPO_READ || proc->type == PROC_REPO_WRITE) {
899 if (client->repo == NULL)
900 fatalx("no process found for uid %d", client->euid);
901 if (proc->pid != client->repo->pid) {
902 kill_proc(proc, 1);
903 log_warnx("received message from PID %d for uid %d, "
904 "while PID %d is the process serving this user",
905 proc->pid, client->euid, client->repo->pid);
906 return 0;
907 }
908 }
909 if (proc->type == PROC_SESSION_READ ||
910 proc->type == PROC_SESSION_WRITE) {
911 if (client->session == NULL) {
912 log_warnx("no session found for uid %d", client->euid);
913 return 0;
914 }
915 if (proc->pid != client->session->pid) {
916 kill_proc(proc, 1);
917 log_warnx("received message from PID %d for uid %d, "
918 "while PID %d is the process serving this user",
919 proc->pid, client->euid, client->session->pid);
920 return 0;
921 }
922 }
923
924 switch (imsg->hdr.type) {
925 case GOTD_IMSG_ERROR:
926 ret = 1;
927 break;
928 case GOTD_IMSG_CONNECT:
929 if (proc->type != PROC_LISTEN) {
930 err = got_error_fmt(GOT_ERR_BAD_PACKET,
931 "new connection for uid %d from PID %d "
932 "which is not the listen process",
933 proc->pid, client->euid);
934 } else
935 ret = 1;
936 break;
937 case GOTD_IMSG_ACCESS_GRANTED:
938 if (proc->type != PROC_AUTH) {
939 err = got_error_fmt(GOT_ERR_BAD_PACKET,
940 "authentication of uid %d from PID %d "
941 "which is not the auth process",
942 proc->pid, client->euid);
943 } else
944 ret = 1;
945 break;
946 case GOTD_IMSG_CLIENT_SESSION_READY:
947 if (proc->type != PROC_SESSION_READ &&
948 proc->type != PROC_SESSION_WRITE) {
949 err = got_error_fmt(GOT_ERR_BAD_PACKET,
950 "unexpected \"ready\" signal from PID %d",
951 proc->pid);
952 } else
953 ret = 1;
954 break;
955 case GOTD_IMSG_REPO_CHILD_READY:
956 if (proc->type != PROC_REPO_READ &&
957 proc->type != PROC_REPO_WRITE) {
958 err = got_error_fmt(GOT_ERR_BAD_PACKET,
959 "unexpected \"ready\" signal from PID %d",
960 proc->pid);
961 } else
962 ret = 1;
963 break;
964 case GOTD_IMSG_PACKFILE_DONE:
965 err = ensure_proc_is_reading(client, proc);
966 if (err)
967 log_warnx("uid %d: %s", client->euid, err->msg);
968 else
969 ret = 1;
970 break;
971 case GOTD_IMSG_PACKFILE_INSTALL:
972 case GOTD_IMSG_REF_UPDATES_START:
973 case GOTD_IMSG_REF_UPDATE:
974 err = ensure_proc_is_writing(client, proc);
975 if (err)
976 log_warnx("uid %d: %s", client->euid, err->msg);
977 else
978 ret = 1;
979 break;
980 default:
981 log_debug("%s: unexpected imsg %d", __func__, imsg->hdr.type);
982 break;
983 }
984
985 return ret;
986 }
987
988 static const struct got_error *
989 connect_repo_child(struct gotd_client *client,
990 struct gotd_child_proc *repo_proc)
991 {
992 static const struct got_error *err;
993 struct gotd_imsgev *session_iev = &client->session->iev;
994 struct gotd_imsg_connect_repo_child ireq;
995 int pipe[2];
996 int sock_flags = SOCK_STREAM | SOCK_NONBLOCK;
997
998 #ifdef SOCK_CLOEXEC
999 sock_flags |= SOCK_CLOEXEC;
1000 #endif
1001
1002 if (client->state != GOTD_CLIENT_STATE_ACCESS_GRANTED)
1003 return got_error_msg(GOT_ERR_BAD_REQUEST,
1004 "unexpected repo child ready signal received");
1005
1006 if (socketpair(AF_UNIX, sock_flags, PF_UNSPEC, pipe) == -1)
1007 fatal("socketpair");
1008
1009 memset(&ireq, 0, sizeof(ireq));
1010 ireq.client_id = client->id;
1011 ireq.proc_id = repo_proc->type;
1012
1013 /* Pass repo child pipe to session child process. */
1014 if (gotd_imsg_compose_event(session_iev, GOTD_IMSG_CONNECT_REPO_CHILD,
1015 PROC_GOTD, pipe[0], &ireq, sizeof(ireq)) == -1) {
1016 err = got_error_from_errno("imsg compose CONNECT_REPO_CHILD");
1017 close(pipe[0]);
1018 close(pipe[1]);
1019 return err;
1020 }
1021
1022 /* Pass session child pipe to repo child process. */
1023 if (gotd_imsg_compose_event(&repo_proc->iev,
1024 GOTD_IMSG_CONNECT_REPO_CHILD, PROC_GOTD, pipe[1], NULL, 0) == -1) {
1025 err = got_error_from_errno("imsg compose CONNECT_REPO_CHILD");
1026 close(pipe[1]);
1027 return err;
1028 }
1029
1030 return NULL;
1031 }
1032
1033 static void
1034 gotd_dispatch_listener(int fd, short event, void *arg)
1035 {
1036 struct gotd_imsgev *iev = arg;
1037 struct imsgbuf *ibuf = &iev->ibuf;
1038 struct gotd_child_proc *proc = gotd.listen_proc;
1039 ssize_t n;
1040 int shut = 0;
1041 struct imsg imsg;
1042
1043 if (proc->iev.ibuf.fd != fd)
1044 fatalx("%s: unexpected fd %d", __func__, fd);
1045
1046 if (event & EV_READ) {
1047 if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1048 fatal("imsg_read error");
1049 if (n == 0) {
1050 /* Connection closed. */
1051 shut = 1;
1052 goto done;
1053 }
1054 }
1055
1056 if (event & EV_WRITE) {
1057 n = msgbuf_write(&ibuf->w);
1058 if (n == -1 && errno != EAGAIN)
1059 fatal("msgbuf_write");
1060 if (n == 0) {
1061 /* Connection closed. */
1062 shut = 1;
1063 goto done;
1064 }
1065 }
1066
1067 for (;;) {
1068 const struct got_error *err = NULL;
1069 struct gotd_client *client = NULL;
1070 uint32_t client_id = 0;
1071 int do_disconnect = 0;
1072
1073 if ((n = imsg_get(ibuf, &imsg)) == -1)
1074 fatal("%s: imsg_get error", __func__);
1075 if (n == 0) /* No more messages. */
1076 break;
1077
1078 switch (imsg.hdr.type) {
1079 case GOTD_IMSG_ERROR:
1080 do_disconnect = 1;
1081 err = gotd_imsg_recv_error(&client_id, &imsg);
1082 break;
1083 case GOTD_IMSG_CONNECT:
1084 err = recv_connect(&client_id, &imsg);
1085 break;
1086 default:
1087 log_debug("unexpected imsg %d", imsg.hdr.type);
1088 break;
1089 }
1090
1091 client = find_client(client_id);
1092 if (client == NULL) {
1093 log_warnx("%s: client not found", __func__);
1094 imsg_free(&imsg);
1095 continue;
1096 }
1097
1098 if (err)
1099 log_warnx("uid %d: %s", client->euid, err->msg);
1100
1101 if (do_disconnect) {
1102 if (err)
1103 disconnect_on_error(client, err);
1104 else
1105 disconnect(client);
1106 }
1107
1108 imsg_free(&imsg);
1109 }
1110 done:
1111 if (!shut) {
1112 gotd_imsg_event_add(iev);
1113 } else {
1114 /* This pipe is dead. Remove its event handler */
1115 event_del(&iev->ev);
1116 event_loopexit(NULL);
1117 }
1118 }
1119
1120 static void
1121 gotd_dispatch_auth_child(int fd, short event, void *arg)
1122 {
1123 const struct got_error *err = NULL;
1124 struct gotd_imsgev *iev = arg;
1125 struct imsgbuf *ibuf = &iev->ibuf;
1126 struct gotd_client *client;
1127 struct gotd_repo *repo = NULL;
1128 ssize_t n;
1129 int shut = 0;
1130 struct imsg imsg;
1131 uint32_t client_id = 0;
1132 int do_disconnect = 0;
1133
1134 client = find_client_by_proc_fd(fd);
1135 if (client == NULL) {
1136 /* Can happen during process teardown. */
1137 warnx("cannot find client for fd %d", fd);
1138 shut = 1;
1139 goto done;
1140 }
1141
1142 if (client->auth == NULL)
1143 fatalx("cannot find auth child process for fd %d", fd);
1144
1145 if (event & EV_READ) {
1146 if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1147 fatal("imsg_read error");
1148 if (n == 0) {
1149 /* Connection closed. */
1150 shut = 1;
1151 goto done;
1152 }
1153 }
1154
1155 if (event & EV_WRITE) {
1156 n = msgbuf_write(&ibuf->w);
1157 if (n == -1 && errno != EAGAIN)
1158 fatal("msgbuf_write");
1159 if (n == 0) {
1160 /* Connection closed. */
1161 shut = 1;
1162 }
1163 goto done;
1164 }
1165
1166 if (client->auth->iev.ibuf.fd != fd)
1167 fatalx("%s: unexpected fd %d", __func__, fd);
1168
1169 if ((n = imsg_get(ibuf, &imsg)) == -1)
1170 fatal("%s: imsg_get error", __func__);
1171 if (n == 0) /* No more messages. */
1172 return;
1173
1174 evtimer_del(&client->tmo);
1175
1176 switch (imsg.hdr.type) {
1177 case GOTD_IMSG_ERROR:
1178 do_disconnect = 1;
1179 err = gotd_imsg_recv_error(&client_id, &imsg);
1180 break;
1181 case GOTD_IMSG_ACCESS_GRANTED:
1182 client->state = GOTD_CLIENT_STATE_ACCESS_GRANTED;
1183 break;
1184 default:
1185 do_disconnect = 1;
1186 log_debug("unexpected imsg %d", imsg.hdr.type);
1187 break;
1188 }
1189
1190 if (!verify_imsg_src(client, client->auth, &imsg)) {
1191 do_disconnect = 1;
1192 log_debug("dropping imsg type %d from PID %d",
1193 imsg.hdr.type, client->auth->pid);
1194 }
1195 imsg_free(&imsg);
1196
1197 if (do_disconnect) {
1198 if (err)
1199 disconnect_on_error(client, err);
1200 else
1201 disconnect(client);
1202 return;
1203 }
1204
1205 repo = gotd_find_repo_by_name(client->auth->repo_name, &gotd);
1206 if (repo == NULL) {
1207 err = got_error(GOT_ERR_NOT_GIT_REPO);
1208 goto done;
1209 }
1210 kill_auth_proc(client);
1211
1212 log_info("authenticated uid %d for repository %s",
1213 client->euid, repo->name);
1214
1215 err = start_session_child(client, repo, gotd.argv0,
1216 gotd.confpath, gotd.daemonize, gotd.verbosity);
1217 if (err)
1218 goto done;
1219 done:
1220 if (err)
1221 log_warnx("uid %d: %s", client->euid, err->msg);
1222
1223 /* We might have killed the auth process by now. */
1224 if (client->auth != NULL) {
1225 if (!shut) {
1226 gotd_imsg_event_add(iev);
1227 } else {
1228 /* This pipe is dead. Remove its event handler */
1229 event_del(&iev->ev);
1230 }
1231 }
1232 }
1233
1234 static const struct got_error *
1235 connect_session(struct gotd_client *client)
1236 {
1237 const struct got_error *err = NULL;
1238 struct gotd_imsg_connect iconnect;
1239 int s;
1240
1241 memset(&iconnect, 0, sizeof(iconnect));
1242
1243 s = dup(client->fd);
1244 if (s == -1)
1245 return got_error_from_errno("dup");
1246
1247 iconnect.client_id = client->id;
1248 iconnect.euid = client->euid;
1249 iconnect.egid = client->egid;
1250
1251 if (gotd_imsg_compose_event(&client->session->iev, GOTD_IMSG_CONNECT,
1252 PROC_GOTD, s, &iconnect, sizeof(iconnect)) == -1) {
1253 err = got_error_from_errno("imsg compose CONNECT");
1254 close(s);
1255 return err;
1256 }
1257
1258 /*
1259 * We are no longer interested in messages from this client.
1260 * Further client requests will be handled by the session process.
1261 */
1262 msgbuf_clear(&client->iev.ibuf.w);
1263 imsg_clear(&client->iev.ibuf);
1264 event_del(&client->iev.ev);
1265 client->fd = -1; /* will be closed via copy in client->iev.ibuf.fd */
1266
1267 return NULL;
1268 }
1269
1270 static void
1271 gotd_dispatch_client_session(int fd, short event, void *arg)
1272 {
1273 struct gotd_imsgev *iev = arg;
1274 struct imsgbuf *ibuf = &iev->ibuf;
1275 struct gotd_child_proc *proc = NULL;
1276 struct gotd_client *client = NULL;
1277 ssize_t n;
1278 int shut = 0;
1279 struct imsg imsg;
1280
1281 client = find_client_by_proc_fd(fd);
1282 if (client == NULL) {
1283 /* Can happen during process teardown. */
1284 warnx("cannot find client for fd %d", fd);
1285 shut = 1;
1286 goto done;
1287 }
1288
1289 if (event & EV_READ) {
1290 if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1291 fatal("imsg_read error");
1292 if (n == 0) {
1293 /* Connection closed. */
1294 shut = 1;
1295 goto done;
1296 }
1297 }
1298
1299 if (event & EV_WRITE) {
1300 n = msgbuf_write(&ibuf->w);
1301 if (n == -1 && errno != EAGAIN)
1302 fatal("msgbuf_write");
1303 if (n == 0) {
1304 /* Connection closed. */
1305 shut = 1;
1306 goto done;
1307 }
1308 }
1309
1310 proc = client->session;
1311 if (proc == NULL)
1312 fatalx("cannot find session child process for fd %d", fd);
1313
1314 for (;;) {
1315 const struct got_error *err = NULL;
1316 uint32_t client_id = 0;
1317 int do_disconnect = 0, do_start_repo_child = 0;
1318
1319 if ((n = imsg_get(ibuf, &imsg)) == -1)
1320 fatal("%s: imsg_get error", __func__);
1321 if (n == 0) /* No more messages. */
1322 break;
1323
1324 switch (imsg.hdr.type) {
1325 case GOTD_IMSG_ERROR:
1326 do_disconnect = 1;
1327 err = gotd_imsg_recv_error(&client_id, &imsg);
1328 break;
1329 case GOTD_IMSG_CLIENT_SESSION_READY:
1330 if (client->state != GOTD_CLIENT_STATE_ACCESS_GRANTED) {
1331 err = got_error(GOT_ERR_PRIVSEP_MSG);
1332 break;
1333 }
1334 do_start_repo_child = 1;
1335 break;
1336 case GOTD_IMSG_DISCONNECT:
1337 do_disconnect = 1;
1338 break;
1339 default:
1340 log_debug("unexpected imsg %d", imsg.hdr.type);
1341 break;
1342 }
1343
1344 if (!verify_imsg_src(client, proc, &imsg)) {
1345 log_debug("dropping imsg type %d from PID %d",
1346 imsg.hdr.type, proc->pid);
1347 imsg_free(&imsg);
1348 continue;
1349 }
1350 if (err)
1351 log_warnx("uid %d: %s", client->euid, err->msg);
1352
1353 if (do_start_repo_child) {
1354 struct gotd_repo *repo;
1355 const char *name = client->session->repo_name;
1356
1357 repo = gotd_find_repo_by_name(name, &gotd);
1358 if (repo != NULL) {
1359 enum gotd_procid proc_type;
1360
1361 if (client->required_auth & GOTD_AUTH_WRITE)
1362 proc_type = PROC_REPO_WRITE;
1363 else
1364 proc_type = PROC_REPO_READ;
1365
1366 err = start_repo_child(client, proc_type, repo,
1367 gotd.argv0, gotd.confpath, gotd.daemonize,
1368 gotd.verbosity);
1369 } else
1370 err = got_error(GOT_ERR_NOT_GIT_REPO);
1371
1372 if (err) {
1373 log_warnx("uid %d: %s", client->euid, err->msg);
1374 do_disconnect = 1;
1375 }
1376 }
1377
1378 if (do_disconnect) {
1379 if (err)
1380 disconnect_on_error(client, err);
1381 else
1382 disconnect(client);
1383 }
1384
1385 imsg_free(&imsg);
1386 }
1387 done:
1388 if (!shut) {
1389 gotd_imsg_event_add(iev);
1390 } else {
1391 /* This pipe is dead. Remove its event handler */
1392 event_del(&iev->ev);
1393 disconnect(client);
1394 }
1395 }
1396
1397 static void
1398 gotd_dispatch_repo_child(int fd, short event, void *arg)
1399 {
1400 struct gotd_imsgev *iev = arg;
1401 struct imsgbuf *ibuf = &iev->ibuf;
1402 struct gotd_child_proc *proc = NULL;
1403 struct gotd_client *client;
1404 ssize_t n;
1405 int shut = 0;
1406 struct imsg imsg;
1407
1408 client = find_client_by_proc_fd(fd);
1409 if (client == NULL) {
1410 /* Can happen during process teardown. */
1411 warnx("cannot find client for fd %d", fd);
1412 shut = 1;
1413 goto done;
1414 }
1415
1416 if (event & EV_READ) {
1417 if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
1418 fatal("imsg_read error");
1419 if (n == 0) {
1420 /* Connection closed. */
1421 shut = 1;
1422 goto done;
1423 }
1424 }
1425
1426 if (event & EV_WRITE) {
1427 n = msgbuf_write(&ibuf->w);
1428 if (n == -1 && errno != EAGAIN)
1429 fatal("msgbuf_write");
1430 if (n == 0) {
1431 /* Connection closed. */
1432 shut = 1;
1433 goto done;
1434 }
1435 }
1436
1437 proc = client->repo;
1438 if (proc == NULL)
1439 fatalx("cannot find child process for fd %d", fd);
1440
1441 for (;;) {
1442 const struct got_error *err = NULL;
1443 uint32_t client_id = 0;
1444 int do_disconnect = 0;
1445
1446 if ((n = imsg_get(ibuf, &imsg)) == -1)
1447 fatal("%s: imsg_get error", __func__);
1448 if (n == 0) /* No more messages. */
1449 break;
1450
1451 switch (imsg.hdr.type) {
1452 case GOTD_IMSG_ERROR:
1453 do_disconnect = 1;
1454 err = gotd_imsg_recv_error(&client_id, &imsg);
1455 break;
1456 case GOTD_IMSG_REPO_CHILD_READY:
1457 err = connect_session(client);
1458 if (err)
1459 break;
1460 err = connect_repo_child(client, proc);
1461 break;
1462 default:
1463 log_debug("unexpected imsg %d", imsg.hdr.type);
1464 break;
1465 }
1466
1467 if (!verify_imsg_src(client, proc, &imsg)) {
1468 log_debug("dropping imsg type %d from PID %d",
1469 imsg.hdr.type, proc->pid);
1470 imsg_free(&imsg);
1471 continue;
1472 }
1473 if (err)
1474 log_warnx("uid %d: %s", client->euid, err->msg);
1475
1476 if (do_disconnect) {
1477 if (err)
1478 disconnect_on_error(client, err);
1479 else
1480 disconnect(client);
1481 }
1482
1483 imsg_free(&imsg);
1484 }
1485 done:
1486 if (!shut) {
1487 gotd_imsg_event_add(iev);
1488 } else {
1489 /* This pipe is dead. Remove its event handler */
1490 event_del(&iev->ev);
1491 disconnect(client);
1492 }
1493 }
1494
1495 static pid_t
1496 start_child(enum gotd_procid proc_id, const char *repo_path,
1497 char *argv0, const char *confpath, int fd, int daemonize, int verbosity)
1498 {
1499 char *argv[11];
1500 int argc = 0;
1501 pid_t pid;
1502
1503 switch (pid = fork()) {
1504 case -1:
1505 fatal("cannot fork");
1506 case 0:
1507 break;
1508 default:
1509 close(fd);
1510 return pid;
1511 }
1512
1513 if (fd != GOTD_FILENO_MSG_PIPE) {
1514 if (dup2(fd, GOTD_FILENO_MSG_PIPE) == -1)
1515 fatal("cannot setup imsg fd");
1516 } else if (fcntl(fd, F_SETFD, 0) == -1)
1517 fatal("cannot setup imsg fd");
1518
1519 argv[argc++] = argv0;
1520 switch (proc_id) {
1521 case PROC_LISTEN:
1522 argv[argc++] = (char *)"-L";
1523 break;
1524 case PROC_AUTH:
1525 argv[argc++] = (char *)"-A";
1526 break;
1527 case PROC_SESSION_READ:
1528 argv[argc++] = (char *)"-s";
1529 break;
1530 case PROC_SESSION_WRITE:
1531 argv[argc++] = (char *)"-S";
1532 break;
1533 case PROC_REPO_READ:
1534 argv[argc++] = (char *)"-R";
1535 break;
1536 case PROC_REPO_WRITE:
1537 argv[argc++] = (char *)"-W";
1538 break;
1539 default:
1540 fatalx("invalid process id %d", proc_id);
1541 }
1542
1543 argv[argc++] = (char *)"-f";
1544 argv[argc++] = (char *)confpath;
1545
1546 if (repo_path) {
1547 argv[argc++] = (char *)"-P";
1548 argv[argc++] = (char *)repo_path;
1549 }
1550
1551 if (!daemonize)
1552 argv[argc++] = (char *)"-d";
1553 if (verbosity > 0)
1554 argv[argc++] = (char *)"-v";
1555 if (verbosity > 1)
1556 argv[argc++] = (char *)"-v";
1557 argv[argc++] = NULL;
1558
1559 execvp(argv0, argv);
1560 fatal("execvp");
1561 }
1562
1563 static void
1564 start_listener(char *argv0, const char *confpath, int daemonize, int verbosity)
1565 {
1566 struct gotd_child_proc *proc;
1567
1568 proc = calloc(1, sizeof(*proc));
1569 if (proc == NULL)
1570 fatal("calloc");
1571
1572 TAILQ_INSERT_HEAD(&procs, proc, entry);
1573
1574 /* proc->tmo is initialized in main() after event_init() */
1575
1576 proc->type = PROC_LISTEN;
1577
1578 if (socketpair(AF_UNIX, sock_flags,
1579 PF_UNSPEC, proc->pipe) == -1)
1580 fatal("socketpair");
1581
1582 proc->pid = start_child(proc->type, NULL, argv0, confpath,
1583 proc->pipe[1], daemonize, verbosity);
1584 imsg_init(&proc->iev.ibuf, proc->pipe[0]);
1585 proc->iev.handler = gotd_dispatch_listener;
1586 proc->iev.events = EV_READ;
1587 proc->iev.handler_arg = NULL;
1588
1589 gotd.listen_proc = proc;
1590 }
1591
1592 static const struct got_error *
1593 start_session_child(struct gotd_client *client, struct gotd_repo *repo,
1594 char *argv0, const char *confpath, int daemonize, int verbosity)
1595 {
1596 struct gotd_child_proc *proc;
1597 int sock_flags = SOCK_STREAM | SOCK_NONBLOCK;
1598
1599 #ifdef SOCK_CLOEXEC
1600 sock_flags |= SOCK_CLOEXEC;
1601 #endif
1602
1603 proc = calloc(1, sizeof(*proc));
1604 if (proc == NULL)
1605 return got_error_from_errno("calloc");
1606
1607 TAILQ_INSERT_HEAD(&procs, proc, entry);
1608 evtimer_set(&proc->tmo, kill_proc_timeout, proc);
1609
1610 if (client_is_reading(client))
1611 proc->type = PROC_SESSION_READ;
1612 else
1613 proc->type = PROC_SESSION_WRITE;
1614 if (strlcpy(proc->repo_name, repo->name,
1615 sizeof(proc->repo_name)) >= sizeof(proc->repo_name))
1616 fatalx("repository name too long: %s", repo->name);
1617 log_debug("starting client uid %d session for repository %s",
1618 client->euid, repo->name);
1619 if (strlcpy(proc->repo_path, repo->path, sizeof(proc->repo_path)) >=
1620 sizeof(proc->repo_path))
1621 fatalx("repository path too long: %s", repo->path);
1622 if (socketpair(AF_UNIX, sock_flags, PF_UNSPEC, proc->pipe) == -1)
1623 fatal("socketpair");
1624 proc->pid = start_child(proc->type, proc->repo_path, argv0,
1625 confpath, proc->pipe[1], daemonize, verbosity);
1626 imsg_init(&proc->iev.ibuf, proc->pipe[0]);
1627 log_debug("proc %s %s is on fd %d",
1628 gotd_proc_names[proc->type], proc->repo_path,
1629 proc->pipe[0]);
1630 proc->iev.handler = gotd_dispatch_client_session;
1631 proc->iev.events = EV_READ;
1632 proc->iev.handler_arg = NULL;
1633 event_set(&proc->iev.ev, proc->iev.ibuf.fd, EV_READ,
1634 gotd_dispatch_client_session, &proc->iev);
1635 gotd_imsg_event_add(&proc->iev);
1636
1637 client->session = proc;
1638 return NULL;
1639 }
1640
1641 static const struct got_error *
1642 start_repo_child(struct gotd_client *client, enum gotd_procid proc_type,
1643 struct gotd_repo *repo, char *argv0, const char *confpath,
1644 int daemonize, int verbosity)
1645 {
1646 struct gotd_child_proc *proc;
1647 int sock_flags = SOCK_STREAM|SOCK_NONBLOCK;
1648
1649 #ifdef SOCK_CLOEXEC
1650 sock_flags |= SOCK_CLOEXEC;
1651 #endif
1652
1653 if (proc_type != PROC_REPO_READ && proc_type != PROC_REPO_WRITE)
1654 return got_error_msg(GOT_ERR_NOT_IMPL, "bad process type");
1655
1656 proc = calloc(1, sizeof(*proc));
1657 if (proc == NULL)
1658 return got_error_from_errno("calloc");
1659
1660 TAILQ_INSERT_HEAD(&procs, proc, entry);
1661 evtimer_set(&proc->tmo, kill_proc_timeout, proc);
1662
1663 proc->type = proc_type;
1664 if (strlcpy(proc->repo_name, repo->name,
1665 sizeof(proc->repo_name)) >= sizeof(proc->repo_name))
1666 fatalx("repository name too long: %s", repo->name);
1667 log_debug("starting %s for repository %s",
1668 proc->type == PROC_REPO_READ ? "reader" : "writer", repo->name);
1669
1670 if (strlcpy(proc->repo_path, repo->path, sizeof(proc->repo_path)) >=
1671 sizeof(proc->repo_path))
1672 fatalx("repository path too long: %s", repo->path);
1673 if (realpath(repo->path, proc->repo_path) == NULL)
1674 fatal("%s", repo->path);
1675 if (socketpair(AF_UNIX, sock_flags,
1676 PF_UNSPEC, proc->pipe) == -1)
1677 fatal("socketpair");
1678 proc->pid = start_child(proc->type, proc->repo_path, argv0,
1679 confpath, proc->pipe[1], daemonize, verbosity);
1680 imsg_init(&proc->iev.ibuf, proc->pipe[0]);
1681 log_debug("proc %s %s is on fd %d",
1682 gotd_proc_names[proc->type], proc->repo_path,
1683 proc->pipe[0]);
1684 proc->iev.handler = gotd_dispatch_repo_child;
1685 proc->iev.events = EV_READ;
1686 proc->iev.handler_arg = NULL;
1687 event_set(&proc->iev.ev, proc->iev.ibuf.fd, EV_READ,
1688 gotd_dispatch_repo_child, &proc->iev);
1689 gotd_imsg_event_add(&proc->iev);
1690
1691 client->repo = proc;
1692 return NULL;
1693 }
1694
1695 static const struct got_error *
1696 start_auth_child(struct gotd_client *client, int required_auth,
1697 struct gotd_repo *repo, char *argv0, const char *confpath,
1698 int daemonize, int verbosity)
1699 {
1700 const struct got_error *err = NULL;
1701 struct gotd_child_proc *proc;
1702 struct gotd_imsg_auth iauth;
1703 int fd;
1704 int sock_flags = SOCK_STREAM|SOCK_NONBLOCK;
1705
1706 #ifdef SOCK_CLOEXEC
1707 sock_flags |= SOCK_CLOEXEC;
1708 #endif
1709
1710 memset(&iauth, 0, sizeof(iauth));
1711
1712 fd = dup(client->fd);
1713 if (fd == -1)
1714 return got_error_from_errno("dup");
1715
1716 proc = calloc(1, sizeof(*proc));
1717 if (proc == NULL) {
1718 err = got_error_from_errno("calloc");
1719 close(fd);
1720 return err;
1721 }
1722
1723 TAILQ_INSERT_HEAD(&procs, proc, entry);
1724 evtimer_set(&proc->tmo, kill_proc_timeout, proc);
1725
1726 proc->type = PROC_AUTH;
1727 if (strlcpy(proc->repo_name, repo->name,
1728 sizeof(proc->repo_name)) >= sizeof(proc->repo_name))
1729 fatalx("repository name too long: %s", repo->name);
1730 log_debug("starting auth for uid %d repository %s",
1731 client->euid, repo->name);
1732 if (strlcpy(proc->repo_path, repo->path, sizeof(proc->repo_path)) >=
1733 sizeof(proc->repo_path))
1734 fatalx("repository path too long: %s", repo->path);
1735 if (realpath(repo->path, proc->repo_path) == NULL)
1736 fatal("%s", repo->path);
1737 if (socketpair(AF_UNIX, sock_flags,
1738 PF_UNSPEC, proc->pipe) == -1)
1739 fatal("socketpair");
1740 proc->pid = start_child(proc->type, proc->repo_path, argv0,
1741 confpath, proc->pipe[1], daemonize, verbosity);
1742 imsg_init(&proc->iev.ibuf, proc->pipe[0]);
1743 log_debug("proc %s %s is on fd %d",
1744 gotd_proc_names[proc->type], proc->repo_path,
1745 proc->pipe[0]);
1746 proc->iev.handler = gotd_dispatch_auth_child;
1747 proc->iev.events = EV_READ;
1748 proc->iev.handler_arg = NULL;
1749 event_set(&proc->iev.ev, proc->iev.ibuf.fd, EV_READ,
1750 gotd_dispatch_auth_child, &proc->iev);
1751 gotd_imsg_event_add(&proc->iev);
1752
1753 iauth.euid = client->euid;
1754 iauth.egid = client->egid;
1755 iauth.required_auth = required_auth;
1756 iauth.client_id = client->id;
1757 if (gotd_imsg_compose_event(&proc->iev, GOTD_IMSG_AUTHENTICATE,
1758 PROC_GOTD, fd, &iauth, sizeof(iauth)) == -1) {
1759 log_warn("imsg compose AUTHENTICATE");
1760 close(fd);
1761 /* Let the auth_timeout handler tidy up. */
1762 }
1763
1764 client->auth = proc;
1765 client->required_auth = required_auth;
1766 return NULL;
1767 }
1768
1769 static void
1770 apply_unveil_repo_readonly(const char *repo_path, int need_tmpdir)
1771 {
1772 if (need_tmpdir) {
1773 if (unveil(GOT_TMPDIR_STR, "rwc") == -1)
1774 fatal("unveil %s", GOT_TMPDIR_STR);
1775 }
1776
1777 if (unveil(repo_path, "r") == -1)
1778 fatal("unveil %s", repo_path);
1779
1780 if (unveil(NULL, NULL) == -1)
1781 fatal("unveil");
1782 }
1783
1784 static void
1785 apply_unveil_repo_readwrite(const char *repo_path)
1786 {
1787 if (unveil(repo_path, "rwc") == -1)
1788 fatal("unveil %s", repo_path);
1789
1790 if (unveil(GOT_TMPDIR_STR, "rwc") == -1)
1791 fatal("unveil %s", GOT_TMPDIR_STR);
1792
1793 if (unveil(NULL, NULL) == -1)
1794 fatal("unveil");
1795 }
1796
1797 static void
1798 apply_unveil_none(void)
1799 {
1800 if (unveil("/", "") == -1)
1801 fatal("unveil");
1802
1803 if (unveil(NULL, NULL) == -1)
1804 fatal("unveil");
1805 }
1806
1807 static void
1808 apply_unveil_selfexec(void)
1809 {
1810 if (unveil(gotd.argv0, "x") == -1)
1811 fatal("unveil %s", gotd.argv0);
1812
1813 if (unveil(NULL, NULL) == -1)
1814 fatal("unveil");
1815 }
1816
1817 int
1818 main(int argc, char **argv)
1819 {
1820 const struct got_error *error = NULL;
1821 int ch, fd = -1, daemonize = 1, verbosity = 0, noaction = 0;
1822 const char *confpath = GOTD_CONF_PATH;
1823 char *argv0 = argv[0];
1824 char title[2048];
1825 struct passwd *pw = NULL;
1826 char *repo_path = NULL;
1827 enum gotd_procid proc_id = PROC_GOTD;
1828 struct event evsigint, evsigterm, evsighup, evsigusr1, evsigchld;
1829 int *pack_fds = NULL, *temp_fds = NULL;
1830 struct gotd_repo *repo = NULL;
1831
1832 TAILQ_INIT(&procs);
1833
1834 log_init(1, LOG_DAEMON); /* Log to stderr until daemonized. */
1835
1836 while ((ch = getopt(argc, argv, "Adf:LnP:RsSvW")) != -1) {
1837 switch (ch) {
1838 case 'A':
1839 proc_id = PROC_AUTH;
1840 break;
1841 case 'd':
1842 daemonize = 0;
1843 break;
1844 case 'f':
1845 confpath = optarg;
1846 break;
1847 case 'L':
1848 proc_id = PROC_LISTEN;
1849 break;
1850 case 'n':
1851 noaction = 1;
1852 break;
1853 case 'P':
1854 repo_path = realpath(optarg, NULL);
1855 if (repo_path == NULL)
1856 fatal("realpath '%s'", optarg);
1857 break;
1858 case 'R':
1859 proc_id = PROC_REPO_READ;
1860 break;
1861 case 's':
1862 proc_id = PROC_SESSION_READ;
1863 break;
1864 case 'S':
1865 proc_id = PROC_SESSION_WRITE;
1866 break;
1867 case 'v':
1868 if (verbosity < 3)
1869 verbosity++;
1870 break;
1871 case 'W':
1872 proc_id = PROC_REPO_WRITE;
1873 break;
1874 default:
1875 usage();
1876 }
1877 }
1878
1879 argc -= optind;
1880 argv += optind;
1881
1882 if (argc != 0)
1883 usage();
1884
1885 if (geteuid() && (proc_id == PROC_GOTD || proc_id == PROC_LISTEN))
1886 fatalx("need root privileges");
1887
1888 if (parse_config(confpath, proc_id, &gotd) != 0)
1889 return 1;
1890
1891 pw = getpwnam(gotd.user_name);
1892 if (pw == NULL)
1893 fatalx("user %s not found", gotd.user_name);
1894
1895 if (pw->pw_uid == 0)
1896 fatalx("cannot run %s as the superuser", getprogname());
1897
1898 if (noaction) {
1899 fprintf(stderr, "configuration OK\n");
1900 return 0;
1901 }
1902
1903 gotd.argv0 = argv0;
1904 gotd.daemonize = daemonize;
1905 gotd.verbosity = verbosity;
1906 gotd.confpath = confpath;
1907
1908 /* Require an absolute path in argv[0] for reliable re-exec. */
1909 if (!got_path_is_absolute(argv0))
1910 fatalx("bad path \"%s\": must be an absolute path", argv0);
1911
1912 log_init(daemonize ? 0 : 1, LOG_DAEMON);
1913 log_setverbose(verbosity);
1914
1915 if (proc_id == PROC_GOTD) {
1916 snprintf(title, sizeof(title), "%s", gotd_proc_names[proc_id]);
1917 arc4random_buf(&clients_hash_key, sizeof(clients_hash_key));
1918 if (daemonize && daemon(1, 0) == -1)
1919 fatal("daemon");
1920 gotd.pid = getpid();
1921 start_listener(argv0, confpath, daemonize, verbosity);
1922 } else if (proc_id == PROC_LISTEN) {
1923 snprintf(title, sizeof(title), "%s", gotd_proc_names[proc_id]);
1924 if (verbosity) {
1925 log_info("socket: %s", gotd.unix_socket_path);
1926 log_info("user: %s", pw->pw_name);
1927 }
1928
1929 fd = unix_socket_listen(gotd.unix_socket_path, pw->pw_uid,
1930 pw->pw_gid);
1931 if (fd == -1) {
1932 fatal("cannot listen on unix socket %s",
1933 gotd.unix_socket_path);
1934 }
1935 } else if (proc_id == PROC_AUTH) {
1936 snprintf(title, sizeof(title), "%s %s",
1937 gotd_proc_names[proc_id], repo_path);
1938 } else if (proc_id == PROC_REPO_READ || proc_id == PROC_REPO_WRITE ||
1939 proc_id == PROC_SESSION_READ || proc_id == PROC_SESSION_WRITE) {
1940 error = got_repo_pack_fds_open(&pack_fds);
1941 if (error != NULL)
1942 fatalx("cannot open pack tempfiles: %s", error->msg);
1943 error = got_repo_temp_fds_open(&temp_fds);
1944 if (error != NULL)
1945 fatalx("cannot open pack tempfiles: %s", error->msg);
1946 if (repo_path == NULL)
1947 fatalx("repository path not specified");
1948 snprintf(title, sizeof(title), "%s %s",
1949 gotd_proc_names[proc_id], repo_path);
1950 } else
1951 fatal("invalid process id %d", proc_id);
1952
1953 setproctitle("%s", title);
1954 log_procinit(title);
1955
1956 /* Drop root privileges. */
1957 if (setgid(pw->pw_gid) == -1)
1958 fatal("setgid %d failed", pw->pw_gid);
1959 if (setuid(pw->pw_uid) == -1)
1960 fatal("setuid %d failed", pw->pw_uid);
1961
1962 event_init();
1963
1964 switch (proc_id) {
1965 case PROC_GOTD:
1966 #ifndef PROFILE
1967 /* "exec" promise will be limited to argv[0] via unveil(2). */
1968 if (pledge("stdio proc exec sendfd recvfd unveil", NULL) == -1)
1969 err(1, "pledge");
1970 #endif
1971 break;
1972 case PROC_LISTEN:
1973 #ifndef PROFILE
1974 if (pledge("stdio sendfd unix unveil", NULL) == -1)
1975 err(1, "pledge");
1976 #endif
1977 /*
1978 * Ensure that AF_UNIX bind(2) cannot be used with any other
1979 * sockets by revoking all filesystem access via unveil(2).
1980 */
1981 apply_unveil_none();
1982
1983 listen_main(title, fd, gotd.connection_limits,
1984 gotd.nconnection_limits);
1985 /* NOTREACHED */
1986 break;
1987 case PROC_AUTH:
1988 #ifndef PROFILE
1989 if (pledge("stdio getpw recvfd unix unveil", NULL) == -1)
1990 err(1, "pledge");
1991 #endif
1992 /*
1993 * We need the "unix" pledge promise for getpeername(2) only.
1994 * Ensure that AF_UNIX bind(2) cannot be used by revoking all
1995 * filesystem access via unveil(2). Access to password database
1996 * files will still work since "getpw" bypasses unveil(2).
1997 */
1998 apply_unveil_none();
1999
2000 auth_main(title, &gotd.repos, repo_path);
2001 /* NOTREACHED */
2002 break;
2003 case PROC_SESSION_READ:
2004 case PROC_SESSION_WRITE:
2005 #ifndef PROFILE
2006 /*
2007 * The "recvfd" promise is only needed during setup and
2008 * will be removed in a later pledge(2) call.
2009 */
2010 if (pledge("stdio rpath wpath cpath recvfd sendfd fattr flock "
2011 "unveil", NULL) == -1)
2012 err(1, "pledge");
2013 #endif
2014 if (proc_id == PROC_SESSION_READ)
2015 apply_unveil_repo_readonly(repo_path, 1);
2016 else
2017 apply_unveil_repo_readwrite(repo_path);
2018 session_main(title, repo_path, pack_fds, temp_fds,
2019 &gotd.request_timeout, proc_id);
2020 /* NOTREACHED */
2021 break;
2022 case PROC_REPO_READ:
2023 #ifndef PROFILE
2024 if (pledge("stdio rpath recvfd unveil", NULL) == -1)
2025 err(1, "pledge");
2026 #endif
2027 apply_unveil_repo_readonly(repo_path, 0);
2028 repo_read_main(title, repo_path, pack_fds, temp_fds);
2029 /* NOTREACHED */
2030 exit(0);
2031 case PROC_REPO_WRITE:
2032 #ifndef PROFILE
2033 if (pledge("stdio rpath recvfd unveil", NULL) == -1)
2034 err(1, "pledge");
2035 #endif
2036 apply_unveil_repo_readonly(repo_path, 0);
2037 repo = gotd_find_repo_by_path(repo_path, &gotd);
2038 if (repo == NULL)
2039 fatalx("no repository for path %s", repo_path);
2040 repo_write_main(title, repo_path, pack_fds, temp_fds,
2041 &repo->protected_tag_namespaces,
2042 &repo->protected_branch_namespaces,
2043 &repo->protected_branches);
2044 /* NOTREACHED */
2045 exit(0);
2046 default:
2047 fatal("invalid process id %d", proc_id);
2048 }
2049
2050 if (proc_id != PROC_GOTD)
2051 fatal("invalid process id %d", proc_id);
2052
2053 evtimer_set(&gotd.listen_proc->tmo, kill_proc_timeout,
2054 gotd.listen_proc);
2055
2056 apply_unveil_selfexec();
2057
2058 signal_set(&evsigint, SIGINT, gotd_sighdlr, NULL);
2059 signal_set(&evsigterm, SIGTERM, gotd_sighdlr, NULL);
2060 signal_set(&evsighup, SIGHUP, gotd_sighdlr, NULL);
2061 signal_set(&evsigusr1, SIGUSR1, gotd_sighdlr, NULL);
2062 signal_set(&evsigchld, SIGCHLD, gotd_sighdlr, NULL);
2063 signal(SIGPIPE, SIG_IGN);
2064
2065 signal_add(&evsigint, NULL);
2066 signal_add(&evsigterm, NULL);
2067 signal_add(&evsighup, NULL);
2068 signal_add(&evsigusr1, NULL);
2069 signal_add(&evsigchld, NULL);
2070
2071 gotd_imsg_event_add(&gotd.listen_proc->iev);
2072
2073 event_dispatch();
2074
2075 free(repo_path);
2076 gotd_shutdown();
2077
2078 return 0;
2079 }
portable version of Game of Trees