op public repos

Blob

Date:: Sat Jan 29 15:39:09 2022 UTC
Message:: drop unused function listen_by_id
Actions:: History | Blame | Raw File
1 /*
2  * Copyright (c) 2021, 2022 Omar Polo <op@omarpolo.com>
3  * Copyright (c) 2018 Florian Obser <florian@openbsd.org>
4  * Copyright (c) 2004, 2005 Claudio Jeker <claudio@openbsd.org>
5  * Copyright (c) 2004 Esben Norby <norby@openbsd.org>
6  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
7  *
8  * Permission to use, copy, modify, and distribute this software for any
9  * purpose with or without fee is hereby granted, provided that the above
10  * copyright notice and this permission notice appear in all copies.
11  *
12  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
13  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
14  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
15  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
16  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
17  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
18  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
19  */
20 
21 #include "compat.h"
22 
23 #include <sys/socket.h>
24 #include <sys/types.h>
25 #include <sys/uio.h>
26 
27 #include <endian.h>
28 #include <errno.h>
29 #include <inttypes.h>
30 #include <pwd.h>
31 #include <signal.h>
32 #include <stdint.h>
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <string.h>
36 #include <syslog.h>
37 #include <unistd.h>
38 
39 #include "control.h"
40 #include "kami.h"
41 #include "kamid.h"
42 #include "listener.h"
43 #include "log.h"
44 #include "sandbox.h"
45 #include "utils.h"
46 
47 static struct kd_conf	*listener_conf;
48 static struct imsgev	*iev_main;
49 
50 static void	listener_sig_handler(int, short, void *);
51 __dead void	listener_shutdown(void);
52 
53 SPLAY_HEAD(clients_tree_id, client) clients;
54 
55 struct client {
56 	uint32_t		 id;
57 	uint32_t		 lid;
58 	uint32_t		 lflags;
59 	uint32_t		 msize;
60 	int			 fd;
61 	struct tls		*ctx;
62 	struct event		 event;
63 	struct imsgev		 iev;
64 	struct bufferevent	*bev;
65 	SPLAY_ENTRY(client)	 sp_entry;
66 };
67 
68 static void	listener_imsg_event_add(struct imsgev *, void *);
69 static void	listener_dispatch_client(int, short, void *);
70 static int	listener_imsg_compose_client(struct client *, int,
71     uint32_t, const void *, uint16_t);
72 
73 static void	apply_config(struct kd_conf *);
74 static void	handle_accept(int, short, void *);
75 
76 static void	handle_handshake(int, short, void *);
77 static void	client_read(struct bufferevent *, void *);
78 static void	client_write(struct bufferevent *, void *);
79 static void	client_error(struct bufferevent *, short, void *);
80 static void	client_tls_readcb(int, short, void *);
81 static void	client_tls_writecb(int, short, void *);
82 static void	close_conn(struct client *);
83 static void	handle_close(int, short, void *);
84 
85 static inline int
86 clients_tree_cmp(struct client *a, struct client *b)
87 {
88 	if (a->id == b->id)
89 		return 0;
90 	else if (a->id < b->id)
91 		return -1;
92 	else
93 		return +1;
94 }
95 
96 SPLAY_PROTOTYPE(clients_tree_id, client, sp_entry, clients_tree_cmp);
97 SPLAY_GENERATE(clients_tree_id, client, sp_entry, clients_tree_cmp)
98 
99 static void
100 listener_sig_handler(int sig, short event, void *d)
101 {
102 	/*
103 	 * Normal signal handler rules don't apply because libevent
104 	 * decouples for us.
105 	 */
106 
107 	switch (sig) {
108 	case SIGINT:
109 	case SIGTERM:
110 		listener_shutdown();
111 	default:
112 		fatalx("unexpected signal %d", sig);
113 	}
114 }
115 
116 void
117 listener(int debug, int verbose)
118 {
119 	struct event		 ev_sigint, ev_sigterm;
120 	struct passwd		*pw;
121 
122 	/* listener_conf = config_new_empty(); */
123 
124 	log_init(debug, LOG_DAEMON);
125 	log_setverbose(verbose);
126 
127 	if ((pw = getpwnam(KD_USER)) == NULL)
128 		fatal("getpwnam");
129 
130 	if (chroot(pw->pw_dir) == -1)
131 		fatal("chroot");
132 	if (chdir("/") == -1)
133 		fatal("chdir(\"/\")");
134 
135 	setproctitle("listener");
136 	log_procinit("listener");
137 
138 	if (setgroups(1, &pw->pw_gid) ||
139 	    setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) ||
140 	    setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid))
141 		fatal("can't drop privileges");
142 
143 	event_init();
144 
145 	/* Setup signal handlers(s). */
146 	signal_set(&ev_sigint, SIGINT, listener_sig_handler, NULL);
147 	signal_set(&ev_sigterm, SIGTERM, listener_sig_handler, NULL);
148 
149 	signal_add(&ev_sigint, NULL);
150 	signal_add(&ev_sigterm, NULL);
151 
152 	signal(SIGPIPE, SIG_IGN);
153 	signal(SIGHUP, SIG_IGN);
154 
155 	/* Setup pipe and event handler to the main process. */
156 	if ((iev_main = malloc(sizeof(*iev_main))) == NULL)
157 		fatal(NULL);
158 
159 	imsg_init(&iev_main->ibuf, 3);
160 	iev_main->handler = listener_dispatch_main;
161 
162 	/* Setup event handlers. */
163 	iev_main->events = EV_READ;
164 	event_set(&iev_main->ev, iev_main->ibuf.fd, iev_main->events,
165 	    iev_main->handler, iev_main);
166 	event_add(&iev_main->ev, NULL);
167 
168 	sandbox_listener();
169 	event_dispatch();
170 	listener_shutdown();
171 }
172 
173 __dead void
174 listener_shutdown(void)
175 {
176 	msgbuf_clear(&iev_main->ibuf.w);
177 	close(iev_main->ibuf.fd);
178 
179 	clear_config(listener_conf);
180 
181 	free(iev_main);
182 
183 	log_info("listener exiting");
184 	exit(0);
185 }
186 
187 static void
188 listener_receive_config(struct imsg *imsg, struct kd_conf **nconf,
189     struct kd_pki_conf **pki)
190 {
191 	struct kd_listen_conf *listen;
192 	char *t;
193 
194 	switch (imsg->hdr.type) {
195 	case IMSG_RECONF_CONF:
196 		if (*nconf != NULL)
197 			fatalx("%s: IMSG_RECONF_CONF already in "
198 			    "progress", __func__);
199 
200 		if (IMSG_DATA_SIZE(*imsg) != sizeof(struct kd_conf))
201 			fatalx("%s: IMSG_RECONF_CONF wrong length: %lu",
202 			    __func__, IMSG_DATA_SIZE(*imsg));
203 		if ((*nconf = malloc(sizeof(**nconf))) == NULL)
204 			fatal(NULL);
205 		memcpy(*nconf, imsg->data, sizeof(**nconf));
206 		STAILQ_INIT(&(*nconf)->pki_head);
207 		STAILQ_INIT(&(*nconf)->table_head);
208 		STAILQ_INIT(&(*nconf)->listen_head);
209 		break;
210 	case IMSG_RECONF_PKI:
211 		if (*nconf == NULL)
212 			fatalx("%s: IMSG_RECONF_PKI without "
213 			    "IMSG_RECONF_CONF", __func__);
214 		*pki = xcalloc(1, sizeof(**pki));
215 		t = imsg->data;
216 		t[IMSG_DATA_SIZE(*imsg)-1] = '\0';
217 		strlcpy((*pki)->name, t, sizeof((*pki)->name));
218 		break;
219 	case IMSG_RECONF_PKI_CERT:
220 		if (*pki == NULL)
221 			fatalx("%s: IMSG_RECONF_PKI_CERT without "
222 			    "IMSG_RECONF_PKI", __func__);
223 		(*pki)->certlen = IMSG_DATA_SIZE(*imsg);
224 		(*pki)->cert = xmemdup(imsg->data, (*pki)->certlen);
225 		break;
226 	case IMSG_RECONF_PKI_KEY:
227 		if (*pki == NULL)
228 			fatalx("%s: IMSG_RECONF_PKI_KEY without "
229 			    "IMSG_RECONF_PKI", __func__);
230 		(*pki)->keylen = IMSG_DATA_SIZE(*imsg);
231 		(*pki)->key = xmemdup(imsg->data, (*pki)->keylen);
232 		STAILQ_INSERT_HEAD(&(*nconf)->pki_head, *pki, entry);
233 		pki = NULL;
234 		break;
235 	case IMSG_RECONF_LISTEN:
236 		if (*nconf == NULL)
237 			fatalx("%s: IMSG_RECONF_LISTEN without "
238 			    "IMSG_RECONF_CONF", __func__);
239 		if (IMSG_DATA_SIZE(*imsg) != sizeof(*listen))
240 			fatalx("%s: IMSG_RECONF_LISTEN wrong length: %lu",
241 			    __func__, IMSG_DATA_SIZE(*imsg));
242 		listen = xcalloc(1, sizeof(*listen));
243 		memcpy(listen, imsg->data, sizeof(*listen));
244 		memset(&listen->entry, 0, sizeof(listen->entry));
245 		if ((listen->fd = imsg->fd) == -1)
246 			fatalx("%s: IMSG_RECONF_LISTEN no fd",
247 			    __func__);
248 		listen->auth_table = NULL;
249 		memset(&listen->ev, 0, sizeof(listen->ev));
250 		STAILQ_INSERT_HEAD(&(*nconf)->listen_head, listen, entry);
251 		break;
252 	case IMSG_RECONF_END:
253 		if (*nconf == NULL)
254 			fatalx("%s: IMSG_RECONF_END without "
255 			    "IMSG_RECONF_CONF", __func__);
256 		apply_config(*nconf);
257 		*nconf = NULL;
258 		break;
259 	}
260 }
261 
262 void
263 listener_dispatch_main(int fd, short event, void *d)
264 {
265 	static struct kd_conf		*nconf;
266 	static struct kd_pki_conf	*pki;
267 	struct client			*client, find;
268 	struct imsg			 imsg;
269 	struct imsgev			*iev = d;
270 	struct imsgbuf			*ibuf;
271 	ssize_t				 n;
272 	int				 shut = 0;
273 
274 	ibuf = &iev->ibuf;
275 
276 	if (event & EV_READ) {
277 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
278 			fatal("imsg_read error");
279 		if (n == 0)	/* Connection closed. */
280 			shut = 1;
281 	}
282 	if (event & EV_WRITE) {
283 		if ((n = msgbuf_write(&ibuf->w)) == -1 && errno != EAGAIN)
284 			fatal("msgbuf_write");
285 		if (n == 0)	/* Connection closed. */
286 			shut = 1;
287 	}
288 
289 	for (;;) {
290 		if ((n = imsg_get(ibuf, &imsg)) == -1)
291 			fatal("%s: imsg_get error", __func__);
292 		if (n == 0)	/* No more messages. */
293 			break;
294 
295 		switch (imsg.hdr.type) {
296 		case IMSG_CTL_LOG_VERBOSE:
297 			if (IMSG_DATA_SIZE(imsg) != sizeof(verbose))
298 				fatalx("wrong size for IMSG_CTL_LOG_VERBOSE");
299 			memcpy(&verbose, imsg.data, sizeof(verbose));
300 			log_setverbose(verbose);
301 			SPLAY_FOREACH(client, clients_tree_id, &clients)
302 				listener_imsg_compose_client(client,
303 				    imsg.hdr.type, 0,
304 				    &verbose, sizeof(verbose));
305 			break;
306 		case IMSG_CTL_DEBUG:
307 			if (SPLAY_EMPTY(&clients))
308 				listener_imsg_compose_main(IMSG_CTL_DEBUG_END,
309 				    imsg.hdr.peerid, NULL, 0);
310 			SPLAY_FOREACH(client, clients_tree_id, &clients)
311 				listener_imsg_compose_client(client,
312 				    imsg.hdr.type, imsg.hdr.peerid,
313 				    imsg.data, IMSG_DATA_SIZE(imsg));
314 			break;
315 		case IMSG_RECONF_CONF:
316 		case IMSG_RECONF_PKI:
317 		case IMSG_RECONF_PKI_CERT:
318 		case IMSG_RECONF_PKI_KEY:
319 		case IMSG_RECONF_LISTEN:
320 		case IMSG_RECONF_END:
321 			listener_receive_config(&imsg, &nconf, &pki);
322 			break;
323 		case IMSG_AUTH:
324 			if (IMSG_DATA_SIZE(imsg) != sizeof(struct kd_auth_proc))
325 				fatalx("mismatching size for IMSG_AUTH");
326 
327 			find.id = imsg.hdr.peerid;
328 			client = SPLAY_FIND(clients_tree_id, &clients, &find);
329 			if (client == NULL) {
330 				if (imsg.fd != -1)
331 					close(imsg.fd);
332 				break;
333 			}
334 			if (imsg.fd == -1) {
335 				log_info("got fd = -1, auth failed?");
336 				close_conn(client);
337 				break;
338 			}
339 			imsg_init(&client->iev.ibuf, imsg.fd);
340 			client->iev.events = EV_READ;
341 			client->iev.handler = listener_dispatch_client;
342 			event_set(&client->iev.ev, client->iev.ibuf.fd,
343 			    client->iev.events, client->iev.handler, client);
344 			listener_imsg_compose_client(client, IMSG_AUTH,
345 			    client->id, imsg.data, IMSG_DATA_SIZE(imsg));
346 
347 			client->bev = bufferevent_new(client->fd,
348 			    client_read, client_write, client_error,
349 			    client);
350 			if (client->bev == NULL) {
351 				log_info("failed to allocate client buffer");
352 				close_conn(client);
353 				return;
354 			}
355 
356 #if HAVE_EVENT2
357 			evbuffer_unfreeze(client->bev->input, 0);
358 			evbuffer_unfreeze(client->bev->output, 1);
359 #endif
360 
361 			if (client->lflags & L_TLS) {
362 				event_set(&client->bev->ev_read, client->fd,
363 				    EV_READ, client_tls_readcb, client->bev);
364 				event_set(&client->bev->ev_write, client->fd,
365 				    EV_WRITE, client_tls_writecb, client->bev);
366 			}
367 
368 			/*
369 			 * Read or write at least a header before
370 			 * firing the callbacks.  High watermark of 0
371 			 * to never stop reading/writing; probably to
372 			 * be revisited.
373 			 */
374 			/* bufferevent_setwatermark(client->bev, EV_READ|EV_WRITE, */
375 			    /* sizeof(struct np_msg_header), 0); */
376 			bufferevent_enable(client->bev, EV_READ|EV_WRITE);
377 			break;
378 
379 		default:
380 			log_debug("%s: unexpected imsg %d", __func__,
381 			    imsg.hdr.type);
382 			break;
383 		}
384 		imsg_free(&imsg);
385 	}
386 
387 	if (!shut)
388 		listener_imsg_event_add(iev, d);
389 	else {
390 		/* This pipe is dead.  Remove its event handler. */
391 		event_del(&iev->ev);
392 		log_warnx("pipe closed, shutting down...");
393 		event_loopexit(NULL);
394 	}
395 }
396 
397 int
398 listener_imsg_compose_main(int type, uint32_t peerid, const void *data,
399     uint16_t datalen)
400 {
401 	return imsg_compose_event(iev_main, type, peerid, 0, -1, data,
402 	    datalen);
403 }
404 
405 static void
406 listener_imsg_event_add(struct imsgev *iev, void *d)
407 {
408 	iev->events = EV_READ;
409 	if (iev->ibuf.w.queued)
410 		iev->events |= EV_WRITE;
411 
412 	event_del(&iev->ev);
413 	event_set(&iev->ev, iev->ibuf.fd, iev->events, iev->handler, d);
414 	event_add(&iev->ev, NULL);
415 }
416 
417 static void
418 listener_dispatch_client(int fd, short event, void *d)
419 {
420         struct client	 find, *client = d;
421 	struct imsg	 imsg;
422 	struct imsgev	*iev;
423 	struct imsgbuf	*ibuf;
424 	ssize_t		 n;
425 	int		 r, shut = 0;
426 
427 	iev = &client->iev;
428 	ibuf = &iev->ibuf;
429 
430 	if (event & EV_READ) {
431 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
432 			fatal("imsg_read error");
433 		if (n == 0)	/* Connection closed */
434 			shut = 1;
435 	}
436 
437 	if (event & EV_WRITE) {
438 		if ((n = msgbuf_write(&ibuf->w)) == -1 && errno != EAGAIN)
439 			fatal("msgbuf_write");
440 		if (n == 0)	/* Connection closed. */
441 			shut = 1;
442 	}
443 
444 	for (;;) {
445 		if ((n = imsg_get(ibuf, &imsg)) == -1)
446 			fatal("%s: imsg_get error", __func__);
447 		if (n == 0)	/* No more messages. */
448 			break;
449 
450 		switch (imsg.hdr.type) {
451 		case IMSG_CTL_DEBUG_BACK:
452 		case IMSG_CTL_DEBUG_END:
453 			listener_imsg_compose_main(imsg.hdr.type,
454 			    imsg.hdr.peerid, imsg.data, IMSG_DATA_SIZE(imsg));
455 			break;
456 
457 		case IMSG_BUF:
458 			find.id = imsg.hdr.peerid;
459 			client = SPLAY_FIND(clients_tree_id, &clients, &find);
460 			if (client == NULL) {
461 				log_info("got IMSG_BUF but client %d gone",
462 				    imsg.hdr.peerid);
463 				break;
464 			}
465 			r = bufferevent_write(client->bev, imsg.data,
466 			    IMSG_DATA_SIZE(imsg));
467 			if (r == -1) {
468 				log_warn("%s: bufferevent_write failed",
469 				    __func__);
470 				close_conn(client);
471 				break;
472 			}
473 			break;
474 
475 		case IMSG_MSIZE:
476 			if (IMSG_DATA_SIZE(imsg) != sizeof(client->msize))
477 				fatal("IMSG_MSIZE size mismatch: "
478 				    "got %zu want %zu", IMSG_DATA_SIZE(imsg),
479 				    sizeof(client->msize));
480 
481 			memcpy(&client->msize, imsg.data,
482 			    sizeof(client->msize));
483 
484 			if (client->msize == 0)
485 				fatal("IMSG_MSIZE got msize = 0");
486 
487 			break;
488 
489 		case IMSG_CLOSE:
490 			/*
491 			 * Both EVBUFFER_READ or EVBUFFER_WRITE should
492 			 * be fine.
493 			 */
494 			client_error(client->bev, EVBUFFER_READ, client);
495 			break;
496 
497 		default:
498 			log_debug("%s: unexpected imsg %d", __func__,
499 			    imsg.hdr.type);
500 			break;
501 		}
502 		imsg_free(&imsg);
503 	}
504 
505 	if (!shut)
506 		listener_imsg_event_add(iev, d);
507 	else {
508 		/* This pipe is dead.  Remove its handler */
509 		log_debug("client proc vanished");
510                 close_conn(client);
511 	}
512 }
513 
514 static int
515 listener_imsg_compose_client(struct client *client, int type,
516     uint32_t peerid, const void *data, uint16_t len)
517 {
518 	int ret;
519 
520 	if ((ret = imsg_compose(&client->iev.ibuf, type, peerid, 0, -1,
521 	    data, len)) != -1)
522 		listener_imsg_event_add(&client->iev, client);
523 
524 	return ret;
525 }
526 
527 static inline struct kd_pki_conf *
528 pki_by_name(const char *name)
529 {
530         struct kd_pki_conf *pki;
531 
532 	STAILQ_FOREACH(pki, &listener_conf->pki_head, entry) {
533 		if (!strcmp(name, pki->name))
534 			return pki;
535 	}
536 
537 	return NULL;
538 }
539 
540 static void
541 apply_config(struct kd_conf *conf)
542 {
543 	struct kd_pki_conf *pki;
544 	struct kd_listen_conf *listen;
545 	struct client *c;
546 
547 	/* drop any pre-auth inflight connections */
548 	SPLAY_FOREACH(c, clients_tree_id, &clients) {
549 		/*
550 		 * c->event is set only during the handshake and the teardown
551 		 * of the connection; c->bev is set only after auth.  Checking
552 		 * for both ensures we drop only incoming connection in the
553 		 * pre-auth state.
554 		 */
555 		if (event_pending(&c->event, EV_READ|EV_WRITE, NULL) &&
556 		    c->bev == NULL) {
557 			log_warn("closing in-flight connection due to reload");
558 			close_conn(c);
559 		}
560 	}
561 
562 	/* swap the now config with the current one */
563 	clear_config(listener_conf);
564 	listener_conf = conf;
565 
566 	/* prepare the various tls_config */
567 	STAILQ_FOREACH(pki, &listener_conf->pki_head, entry) {
568 		if ((pki->tlsconf = tls_config_new()) == NULL)
569 			fatal("tls_config_new");
570 		tls_config_verify_client_optional(pki->tlsconf);
571 		tls_config_insecure_noverifycert(pki->tlsconf);
572 		if (tls_config_set_keypair_mem(pki->tlsconf,
573 		    pki->cert, pki->certlen,
574 		    pki->key, pki->keylen) == -1)
575 			fatalx("tls_config_set_keypair_mem: %s",
576 			    tls_config_error(pki->tlsconf));
577 	}
578 
579 	/* prepare and kickoff the listeners */
580 	STAILQ_FOREACH(listen, &listener_conf->listen_head, entry) {
581 		if ((listen->ctx = tls_server()) == NULL)
582 			fatal("tls_server");
583 
584 		pki = pki_by_name(listen->pki);
585 		if (tls_configure(listen->ctx, pki->tlsconf) == -1)
586 			fatalx("tls_configure: %s",
587 			    tls_config_error(pki->tlsconf));
588 
589 		event_set(&listen->ev, listen->fd, EV_READ|EV_PERSIST,
590 		    handle_accept, listen);
591 		event_add(&listen->ev, NULL);
592 	}
593 }
594 
595 static inline void
596 yield_r(struct client *c, void (*fn)(int, short, void *))
597 {
598 	if (event_pending(&c->event, EV_WRITE|EV_READ, NULL))
599 		event_del(&c->event);
600 	event_set(&c->event, c->fd, EV_READ, fn, c);
601 	event_add(&c->event, NULL);
602 }
603 
604 static inline void
605 yield_w(struct client *c, void (*fn)(int, short, void *))
606 {
607 	if (event_pending(&c->event, EV_WRITE|EV_READ, NULL))
608 		event_del(&c->event);
609 	event_set(&c->event, c->fd, EV_WRITE, fn, c);
610 	event_add(&c->event, NULL);
611 }
612 
613 static void
614 handle_accept(int fd, short ev, void *data)
615 {
616 	static uint32_t counter;
617 	struct kd_listen_conf *listen = data;
618 	struct client *c;
619 	int s;
620 
621 	if ((s = accept(fd, NULL, NULL)) == -1) {
622 		log_warn("accept");
623 		return;
624 	}
625 
626 	c = xcalloc(1, sizeof(*c));
627 	c->msize = MSIZE9P;
628 	c->lid = listen->id;
629 	c->lflags = listen->flags;
630 	c->iev.ibuf.fd = -1;
631 
632 	if (tls_accept_socket(listen->ctx, &c->ctx, s) == -1) {
633 		log_warnx("tls_accept_socket: %s",
634 		    tls_error(listen->ctx));
635 		free(c);
636 		close(s);
637 		return;
638 	}
639 
640 	c->fd = s;
641 	c->id = counter++;
642 
643 	SPLAY_INSERT(clients_tree_id, &clients, c);
644 
645 	/* initialize the event */
646 	event_set(&c->event, c->fd, EV_READ, NULL, NULL);
647 
648 	yield_r(c, handle_handshake);
649 }
650 
651 static void
652 handle_handshake(int fd, short ev, void *data)
653 {
654 	struct client *c = data;
655 	struct kd_auth_req auth;
656 	ssize_t r;
657 	const char *hash;
658 
659 	switch (r = tls_handshake(c->ctx)) {
660 	case TLS_WANT_POLLIN:
661 		yield_r(c, handle_handshake);
662 		return;
663 	case TLS_WANT_POLLOUT:
664 		yield_w(c, handle_handshake);
665 		return;
666 	case -1:
667 		log_debug("handhsake failed: %s", tls_error(c->ctx));
668 		close_conn(c);
669 		return;
670 	}
671 
672 	if ((hash = tls_peer_cert_hash(c->ctx)) == NULL) {
673 		log_warnx("client didn't provide certificate");
674 		close_conn(c);
675 		return;
676 	}
677 
678 	memset(&auth, 0, sizeof(auth));
679 	auth.listen_id = c->lid;
680 	strlcpy(auth.hash, hash, sizeof(auth.hash));
681 	log_debug("sending hash %s", auth.hash);
682 
683 	listener_imsg_compose_main(IMSG_AUTH_TLS, c->id,
684 	    &auth, sizeof(auth));
685 }
686 
687 static void
688 client_read(struct bufferevent *bev, void *d)
689 {
690 	struct client	*client = d;
691 	struct evbuffer	*src = EVBUFFER_INPUT(bev);
692 	uint32_t	 len;
693 
694 	for (;;) {
695 		if (EVBUFFER_LENGTH(src) < 4)
696 			return;
697 
698 		memcpy(&len, EVBUFFER_DATA(src), sizeof(len));
699 		len = le32toh(len);
700 		log_debug("expecting a message %"PRIu32" bytes long "
701 		    "(of wich %zu already read)",
702 		    len, EVBUFFER_LENGTH(src));
703 
704 		if (len < HEADERSIZE) {
705 			log_warnx("invalid message size %d (too low)", len);
706 			client_error(bev, EVBUFFER_READ, client);
707 			return;
708 		}
709 
710 		if (len > client->msize) {
711 			log_warnx("incoming message bigger than msize "
712 			    "(%"PRIu32" vs %"PRIu32")", len, client->msize);
713 			client_error(bev, EVBUFFER_READ, client);
714 			return;
715 		}
716 
717 		if (len > EVBUFFER_LENGTH(src))
718 			return;
719 
720 		listener_imsg_compose_client(client, IMSG_BUF, client->id,
721 		    EVBUFFER_DATA(src), len);
722 		evbuffer_drain(src, len);
723 	}
724 }
725 
726 static void
727 client_write(struct bufferevent *bev, void *d)
728 {
729 	/*
730 	 * here we can do some fancy logic like deciding when to call
731 	 *
732 	 *	(*bev->errorcb)(bev, EVBUFFER_WRITE, bev->cbarg)
733 	 *
734 	 * to signal the end of the transaction.
735 	 */
736 
737 	return;
738 }
739 
740 static void
741 client_error(struct bufferevent *bev, short err, void *d)
742 {
743 	struct client	*client = d;
744 	struct evbuffer	*buf;
745 
746         if (err & EVBUFFER_ERROR) {
747 		if (errno == EFBIG) {
748 			bufferevent_enable(bev, EV_READ);
749 			return;
750 		}
751 		log_debug("buffer event error");
752                 close_conn(client);
753 		return;
754 	}
755 
756 	if (err & EVBUFFER_EOF) {
757                 close_conn(client);
758 		return;
759 	}
760 
761 	if (err & (EVBUFFER_READ|EVBUFFER_WRITE)) {
762 		bufferevent_disable(bev, EV_READ|EV_WRITE);
763 
764 		buf = EVBUFFER_OUTPUT(client->bev);
765 		if (EVBUFFER_LENGTH(buf) != 0) {
766 			/* finish writing all the data first */
767 			bufferevent_enable(client->bev, EV_WRITE);
768 			return;
769 		}
770 
771 		close_conn(client);
772 		return;
773 	}
774 
775 	log_warnx("unknown event error, closing client connection");
776 	close_conn(client);
777 }
778 
779 static void
780 client_tls_readcb(int fd, short event, void *d)
781 {
782 	struct bufferevent	*bufev = d;
783 	struct client		*client = bufev->cbarg;
784 	char			 buf[IBUF_READ_SIZE];
785 	int			 what = EVBUFFER_READ;
786 	int			 howmuch = IBUF_READ_SIZE;
787 	ssize_t			 ret;
788 	size_t			 len;
789 
790 	if (event == EV_TIMEOUT) {
791 		what |= EVBUFFER_TIMEOUT;
792 		goto err;
793 	}
794 
795 	if (bufev->wm_read.high != 0)
796 		howmuch = MIN(sizeof(buf), bufev->wm_read.high);
797 
798         switch (ret = tls_read(client->ctx, buf, howmuch)) {
799 	case TLS_WANT_POLLIN:
800 	case TLS_WANT_POLLOUT:
801 		goto retry;
802 	case -1:
803 		what |= EVBUFFER_ERROR;
804 		goto err;
805 	}
806 	len = ret;
807 
808 	if (len == 0) {
809 		what |= EVBUFFER_EOF;
810 		goto err;
811 	}
812 
813 	if (evbuffer_add(bufev->input, buf, len) == -1) {
814 		what |= EVBUFFER_ERROR;
815 		goto err;
816 	}
817 
818 	event_add(&bufev->ev_read, NULL);
819 
820 	len = EVBUFFER_LENGTH(bufev->input);
821 	if (bufev->wm_read.low != 0 && len < bufev->wm_read.low)
822 		return;
823 	if (bufev->wm_read.high != 0 && len > bufev->wm_read.high) {
824 		/*
825 		 * here we could implement some read pressure
826 		 * mechanism.
827 		 */
828 	}
829 
830 	if (bufev->readcb != NULL)
831 		(*bufev->readcb)(bufev, bufev->cbarg);
832 
833 	return;
834 
835 retry:
836 	event_add(&bufev->ev_read, NULL);
837 	return;
838 
839 err:
840 	(*bufev->errorcb)(bufev, what, bufev->cbarg);
841 }
842 
843 static void
844 client_tls_writecb(int fd, short event, void *d)
845 {
846 	struct bufferevent	*bufev = d;
847 	struct client		*client = bufev->cbarg;
848 	ssize_t			 ret;
849 	size_t			 len;
850 	short			 what = EVBUFFER_WRITE;
851 
852 	if (event == EV_TIMEOUT) {
853 		what |= EVBUFFER_TIMEOUT;
854 		goto err;
855 	}
856 
857 	if (EVBUFFER_LENGTH(bufev->output) != 0) {
858 		ret = tls_write(client->ctx,
859 		    EVBUFFER_DATA(bufev->output),
860 		    EVBUFFER_LENGTH(bufev->output));
861 		switch (ret) {
862 		case TLS_WANT_POLLIN:
863 		case TLS_WANT_POLLOUT:
864 			goto retry;
865 		case -1:
866 			what |= EVBUFFER_ERROR;
867 			goto err;
868 		}
869 		len = ret;
870 		evbuffer_drain(bufev->output, len);
871 	}
872 
873 	if (EVBUFFER_LENGTH(bufev->output) != 0)
874 		event_add(&bufev->ev_write, NULL);
875 
876 	if (bufev->writecb != NULL &&
877 	    EVBUFFER_LENGTH(bufev->output) <= bufev->wm_write.low)
878 		(*bufev->writecb)(bufev, bufev->cbarg);
879 	return;
880 
881 retry:
882 	event_add(&bufev->ev_write, NULL);
883 	return;
884 
885 err:
886 	(*bufev->errorcb)(bufev, what, bufev->cbarg);
887 }
888 
889 static void
890 close_conn(struct client *c)
891 {
892 	log_debug("closing connection");
893 
894 	SPLAY_REMOVE(clients_tree_id, &clients, c);
895 
896 	if (c->iev.ibuf.fd != -1) {
897 		listener_imsg_compose_client(c, IMSG_CONN_GONE, 0, NULL, 0);
898 		imsg_flush(&c->iev.ibuf);
899 		msgbuf_clear(&c->iev.ibuf.w);
900 		event_del(&c->iev.ev);
901 		close(c->iev.ibuf.fd);
902 	}
903 
904 	handle_close(c->fd, 0, c);
905 }
906 
907 static void
908 handle_close(int fd, short ev, void *d)
909 {
910 	struct client *c = d;
911 
912 	switch (tls_close(c->ctx)) {
913 	case TLS_WANT_POLLIN:
914 		yield_r(c, handle_close);
915 		return;
916 	case TLS_WANT_POLLOUT:
917 		yield_w(c, handle_close);
918 		return;
919 	}
920 
921 	event_del(&c->event);
922 	tls_free(c->ctx);
923 	close(c->fd);
924 	free(c);
925 }