xref: /netbsd-src/sys/netbt/rfcomm_session.c (revision 5bbd2a12505d72a8177929a37b5cee489d0a1cfd)
1 /*	$NetBSD: rfcomm_session.c,v 1.18 2011/07/27 10:25:09 plunky Exp $	*/
2 
3 /*-
4  * Copyright (c) 2006 Itronix Inc.
5  * All rights reserved.
6  *
7  * Written by Iain Hibbert for Itronix Inc.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. The name of Itronix Inc. may not be used to endorse
18  *    or promote products derived from this software without specific
19  *    prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY ITRONIX INC. ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
23  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
24  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL ITRONIX INC. BE LIABLE FOR ANY
25  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
26  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
27  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
28  * ON ANY THEORY OF LIABILITY, WHETHER IN
29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31  * POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include <sys/cdefs.h>
35 __KERNEL_RCSID(0, "$NetBSD: rfcomm_session.c,v 1.18 2011/07/27 10:25:09 plunky Exp $");
36 
37 #include <sys/param.h>
38 #include <sys/kernel.h>
39 #include <sys/mbuf.h>
40 #include <sys/proc.h>
41 #include <sys/socketvar.h>
42 #include <sys/systm.h>
43 #include <sys/types.h>
44 
45 #include <netbt/bluetooth.h>
46 #include <netbt/hci.h>
47 #include <netbt/l2cap.h>
48 #include <netbt/rfcomm.h>
49 
50 /******************************************************************************
51  *
52  * RFCOMM Multiplexer Sessions sit directly on L2CAP channels, and can
53  * multiplex up to 30 incoming and 30 outgoing connections.
54  * Only one Multiplexer is allowed between any two devices.
55  */
56 
57 static void rfcomm_session_timeout(void *);
58 static void rfcomm_session_recv_sabm(struct rfcomm_session *, int);
59 static void rfcomm_session_recv_disc(struct rfcomm_session *, int);
60 static void rfcomm_session_recv_ua(struct rfcomm_session *, int);
61 static void rfcomm_session_recv_dm(struct rfcomm_session *, int);
62 static void rfcomm_session_recv_uih(struct rfcomm_session *, int, int, struct mbuf *, int);
63 static void rfcomm_session_recv_mcc(struct rfcomm_session *, struct mbuf *);
64 static void rfcomm_session_recv_mcc_test(struct rfcomm_session *, int, struct mbuf *);
65 static void rfcomm_session_recv_mcc_fcon(struct rfcomm_session *, int);
66 static void rfcomm_session_recv_mcc_fcoff(struct rfcomm_session *, int);
67 static void rfcomm_session_recv_mcc_msc(struct rfcomm_session *, int, struct mbuf *);
68 static void rfcomm_session_recv_mcc_rpn(struct rfcomm_session *, int, struct mbuf *);
69 static void rfcomm_session_recv_mcc_rls(struct rfcomm_session *, int, struct mbuf *);
70 static void rfcomm_session_recv_mcc_pn(struct rfcomm_session *, int, struct mbuf *);
71 static void rfcomm_session_recv_mcc_nsc(struct rfcomm_session *, int, struct mbuf *);
72 
73 /* L2CAP callbacks */
74 static void rfcomm_session_connecting(void *);
75 static void rfcomm_session_connected(void *);
76 static void rfcomm_session_disconnected(void *, int);
77 static void *rfcomm_session_newconn(void *, struct sockaddr_bt *, struct sockaddr_bt *);
78 static void rfcomm_session_complete(void *, int);
79 static void rfcomm_session_linkmode(void *, int);
80 static void rfcomm_session_input(void *, struct mbuf *);
81 
82 static const struct btproto rfcomm_session_proto = {
83 	rfcomm_session_connecting,
84 	rfcomm_session_connected,
85 	rfcomm_session_disconnected,
86 	rfcomm_session_newconn,
87 	rfcomm_session_complete,
88 	rfcomm_session_linkmode,
89 	rfcomm_session_input,
90 };
91 
92 struct rfcomm_session_list
93 	rfcomm_session_active = LIST_HEAD_INITIALIZER(rfcomm_session_active);
94 
95 struct rfcomm_session_list
96 	rfcomm_session_listen = LIST_HEAD_INITIALIZER(rfcomm_session_listen);
97 
98 static struct pool rfcomm_credit_pool;
99 
100 /*
101  * RFCOMM System Parameters (see section 5.3)
102  */
103 int rfcomm_mtu_default = 127;	/* bytes */
104 int rfcomm_ack_timeout = 20;	/* seconds */
105 int rfcomm_mcc_timeout = 20;	/* seconds */
106 
107 /*
108  * Reversed CRC table as per TS 07.10 Annex B.3.5
109  */
110 static const uint8_t crctable[256] = {	/* reversed, 8-bit, poly=0x07 */
111 	0x00, 0x91, 0xe3, 0x72, 0x07, 0x96, 0xe4, 0x75,
112 	0x0e, 0x9f, 0xed, 0x7c, 0x09, 0x98, 0xea, 0x7b,
113 	0x1c, 0x8d, 0xff, 0x6e, 0x1b, 0x8a, 0xf8, 0x69,
114 	0x12, 0x83, 0xf1, 0x60, 0x15, 0x84, 0xf6, 0x67,
115 
116 	0x38, 0xa9, 0xdb, 0x4a, 0x3f, 0xae, 0xdc, 0x4d,
117 	0x36, 0xa7, 0xd5, 0x44, 0x31, 0xa0, 0xd2, 0x43,
118 	0x24, 0xb5, 0xc7, 0x56, 0x23, 0xb2, 0xc0, 0x51,
119 	0x2a, 0xbb, 0xc9, 0x58, 0x2d, 0xbc, 0xce, 0x5f,
120 
121 	0x70, 0xe1, 0x93, 0x02, 0x77, 0xe6, 0x94, 0x05,
122 	0x7e, 0xef, 0x9d, 0x0c, 0x79, 0xe8, 0x9a, 0x0b,
123 	0x6c, 0xfd, 0x8f, 0x1e, 0x6b, 0xfa, 0x88, 0x19,
124 	0x62, 0xf3, 0x81, 0x10, 0x65, 0xf4, 0x86, 0x17,
125 
126 	0x48, 0xd9, 0xab, 0x3a, 0x4f, 0xde, 0xac, 0x3d,
127 	0x46, 0xd7, 0xa5, 0x34, 0x41, 0xd0, 0xa2, 0x33,
128 	0x54, 0xc5, 0xb7, 0x26, 0x53, 0xc2, 0xb0, 0x21,
129 	0x5a, 0xcb, 0xb9, 0x28, 0x5d, 0xcc, 0xbe, 0x2f,
130 
131 	0xe0, 0x71, 0x03, 0x92, 0xe7, 0x76, 0x04, 0x95,
132 	0xee, 0x7f, 0x0d, 0x9c, 0xe9, 0x78, 0x0a, 0x9b,
133 	0xfc, 0x6d, 0x1f, 0x8e, 0xfb, 0x6a, 0x18, 0x89,
134 	0xf2, 0x63, 0x11, 0x80, 0xf5, 0x64, 0x16, 0x87,
135 
136 	0xd8, 0x49, 0x3b, 0xaa, 0xdf, 0x4e, 0x3c, 0xad,
137 	0xd6, 0x47, 0x35, 0xa4, 0xd1, 0x40, 0x32, 0xa3,
138 	0xc4, 0x55, 0x27, 0xb6, 0xc3, 0x52, 0x20, 0xb1,
139 	0xca, 0x5b, 0x29, 0xb8, 0xcd, 0x5c, 0x2e, 0xbf,
140 
141 	0x90, 0x01, 0x73, 0xe2, 0x97, 0x06, 0x74, 0xe5,
142 	0x9e, 0x0f, 0x7d, 0xec, 0x99, 0x08, 0x7a, 0xeb,
143 	0x8c, 0x1d, 0x6f, 0xfe, 0x8b, 0x1a, 0x68, 0xf9,
144 	0x82, 0x13, 0x61, 0xf0, 0x85, 0x14, 0x66, 0xf7,
145 
146 	0xa8, 0x39, 0x4b, 0xda, 0xaf, 0x3e, 0x4c, 0xdd,
147 	0xa6, 0x37, 0x45, 0xd4, 0xa1, 0x30, 0x42, 0xd3,
148 	0xb4, 0x25, 0x57, 0xc6, 0xb3, 0x22, 0x50, 0xc1,
149 	0xba, 0x2b, 0x59, 0xc8, 0xbd, 0x2c, 0x5e, 0xcf
150 };
151 
152 #define FCS(f, d)	crctable[(f) ^ (d)]
153 
154 void
155 rfcomm_init(void)
156 {
157 
158 	pool_init(&rfcomm_credit_pool, sizeof(struct rfcomm_credit),
159 	    0, 0, 0, "rfcomm_credit", NULL, IPL_SOFTNET);
160 }
161 
162 /*
163  * rfcomm_session_alloc(list, sockaddr)
164  *
165  * allocate a new session and fill in the blanks, then
166  * attach session to front of specified list (active or listen)
167  */
168 struct rfcomm_session *
169 rfcomm_session_alloc(struct rfcomm_session_list *list,
170 			struct sockaddr_bt *laddr)
171 {
172 	struct rfcomm_session *rs;
173 	struct sockopt sopt;
174 	int err;
175 
176 	rs = malloc(sizeof(*rs), M_BLUETOOTH, M_NOWAIT | M_ZERO);
177 	if (rs == NULL)
178 		return NULL;
179 
180 	rs->rs_state = RFCOMM_SESSION_CLOSED;
181 
182 	callout_init(&rs->rs_timeout, 0);
183 	callout_setfunc(&rs->rs_timeout, rfcomm_session_timeout, rs);
184 
185 	SIMPLEQ_INIT(&rs->rs_credits);
186 	LIST_INIT(&rs->rs_dlcs);
187 
188 	err = l2cap_attach(&rs->rs_l2cap, &rfcomm_session_proto, rs);
189 	if (err) {
190 		free(rs, M_BLUETOOTH);
191 		return NULL;
192 	}
193 
194 	sockopt_init(&sopt, BTPROTO_L2CAP, SO_L2CAP_OMTU, 0);
195 	(void)l2cap_getopt(rs->rs_l2cap, &sopt);
196 	(void)sockopt_get(&sopt, &rs->rs_mtu, sizeof(rs->rs_mtu));
197 	sockopt_destroy(&sopt);
198 
199 	if (laddr->bt_psm == L2CAP_PSM_ANY)
200 		laddr->bt_psm = L2CAP_PSM_RFCOMM;
201 
202 	(void)l2cap_bind(rs->rs_l2cap, laddr);
203 
204 	LIST_INSERT_HEAD(list, rs, rs_next);
205 
206 	return rs;
207 }
208 
209 /*
210  * rfcomm_session_free(rfcomm_session)
211  *
212  * release a session, including any cleanup
213  */
214 void
215 rfcomm_session_free(struct rfcomm_session *rs)
216 {
217 	struct rfcomm_credit *credit;
218 
219 	KASSERT(rs != NULL);
220 	KASSERT(LIST_EMPTY(&rs->rs_dlcs));
221 
222 	rs->rs_state = RFCOMM_SESSION_CLOSED;
223 
224 	/*
225 	 * If the callout is already invoked we have no way to stop it,
226 	 * but it will call us back right away (there are no DLC's) so
227 	 * not to worry.
228 	 */
229 	callout_stop(&rs->rs_timeout);
230 	if (callout_invoking(&rs->rs_timeout))
231 		return;
232 
233 	/*
234 	 * Take care that rfcomm_session_disconnected() doesnt call
235 	 * us back either as it will do if the l2cap_channel has not
236 	 * been closed when we detach it..
237 	 */
238 	if (rs->rs_flags & RFCOMM_SESSION_FREE)
239 		return;
240 
241 	rs->rs_flags |= RFCOMM_SESSION_FREE;
242 
243 	/* throw away any remaining credit notes */
244 	while ((credit = SIMPLEQ_FIRST(&rs->rs_credits)) != NULL) {
245 		SIMPLEQ_REMOVE_HEAD(&rs->rs_credits, rc_next);
246 		pool_put(&rfcomm_credit_pool, credit);
247 	}
248 
249 	KASSERT(SIMPLEQ_EMPTY(&rs->rs_credits));
250 
251 	/* Goodbye! */
252 	LIST_REMOVE(rs, rs_next);
253 	l2cap_detach(&rs->rs_l2cap);
254 	callout_destroy(&rs->rs_timeout);
255 	free(rs, M_BLUETOOTH);
256 }
257 
258 /*
259  * rfcomm_session_lookup(sockaddr, sockaddr)
260  *
261  * Find active rfcomm session matching src and dest addresses
262  * when src is BDADDR_ANY match any local address
263  */
264 struct rfcomm_session *
265 rfcomm_session_lookup(struct sockaddr_bt *src, struct sockaddr_bt *dest)
266 {
267 	struct rfcomm_session *rs;
268 	struct sockaddr_bt addr;
269 
270 	LIST_FOREACH(rs, &rfcomm_session_active, rs_next) {
271 		if (rs->rs_state == RFCOMM_SESSION_CLOSED)
272 			continue;
273 
274 		l2cap_sockaddr(rs->rs_l2cap, &addr);
275 
276 		if (bdaddr_same(&src->bt_bdaddr, &addr.bt_bdaddr) == 0)
277 			if (bdaddr_any(&src->bt_bdaddr) == 0)
278 				continue;
279 
280 		l2cap_peeraddr(rs->rs_l2cap, &addr);
281 
282 		if (addr.bt_psm != dest->bt_psm)
283 			continue;
284 
285 		if (bdaddr_same(&dest->bt_bdaddr, &addr.bt_bdaddr))
286 			break;
287 	}
288 
289 	return rs;
290 }
291 
292 /*
293  * rfcomm_session_timeout(rfcomm_session)
294  *
295  * Session timeouts are scheduled when a session is left or
296  * created with no DLCs, and when SABM(0) or DISC(0) are
297  * sent.
298  *
299  * So, if it is in an open state with DLC's attached then
300  * we leave it alone, otherwise the session is lost.
301  */
302 static void
303 rfcomm_session_timeout(void *arg)
304 {
305 	struct rfcomm_session *rs = arg;
306 	struct rfcomm_dlc *dlc;
307 
308 	KASSERT(rs != NULL);
309 
310 	mutex_enter(bt_lock);
311 	callout_ack(&rs->rs_timeout);
312 
313 	if (rs->rs_state != RFCOMM_SESSION_OPEN) {
314 		DPRINTF("timeout\n");
315 		rs->rs_state = RFCOMM_SESSION_CLOSED;
316 
317 		while (!LIST_EMPTY(&rs->rs_dlcs)) {
318 			dlc = LIST_FIRST(&rs->rs_dlcs);
319 
320 			rfcomm_dlc_close(dlc, ETIMEDOUT);
321 		}
322 	}
323 
324 	if (LIST_EMPTY(&rs->rs_dlcs)) {
325 		DPRINTF("expiring\n");
326 		rfcomm_session_free(rs);
327 	}
328 	mutex_exit(bt_lock);
329 }
330 
331 /***********************************************************************
332  *
333  *	RFCOMM Session L2CAP protocol callbacks
334  *
335  */
336 
337 static void
338 rfcomm_session_connecting(void *arg)
339 {
340 	/* struct rfcomm_session *rs = arg; */
341 
342 	DPRINTF("Connecting\n");
343 }
344 
345 static void
346 rfcomm_session_connected(void *arg)
347 {
348 	struct rfcomm_session *rs = arg;
349 	struct sockopt sopt;
350 
351 	DPRINTF("Connected\n");
352 
353 	/*
354 	 * L2CAP is open.
355 	 *
356 	 * If we are initiator, we can send our SABM(0)
357 	 * a timeout should be active?
358 	 *
359 	 * We must take note of the L2CAP MTU because currently
360 	 * the L2CAP implementation can only do Basic Mode.
361 	 */
362 	sockopt_init(&sopt, BTPROTO_L2CAP, SO_L2CAP_OMTU, 0);
363 	(void)l2cap_getopt(rs->rs_l2cap, &sopt);
364 	(void)sockopt_get(&sopt, &rs->rs_mtu, sizeof(rs->rs_mtu));
365 	sockopt_destroy(&sopt);
366 
367 	rs->rs_mtu -= 6; /* (RFCOMM overhead could be this big) */
368 	if (rs->rs_mtu < RFCOMM_MTU_MIN) {
369 		rfcomm_session_disconnected(rs, EINVAL);
370 		return;
371 	}
372 
373 	if (IS_INITIATOR(rs)) {
374 		int err;
375 
376 		err = rfcomm_session_send_frame(rs, RFCOMM_FRAME_SABM, 0);
377 		if (err)
378 			rfcomm_session_disconnected(rs, err);
379 
380 		callout_schedule(&rs->rs_timeout, rfcomm_ack_timeout * hz);
381 	}
382 }
383 
384 static void
385 rfcomm_session_disconnected(void *arg, int err)
386 {
387 	struct rfcomm_session *rs = arg;
388 	struct rfcomm_dlc *dlc;
389 
390 	DPRINTF("Disconnected\n");
391 
392 	/*
393 	 * If we have any DLCs outstanding in the unlikely case that the
394 	 * L2CAP channel disconnected normally, close them with an error
395 	 */
396 	if (err == 0)
397 		err = ECONNRESET;
398 
399 	rs->rs_state = RFCOMM_SESSION_CLOSED;
400 
401 	while (!LIST_EMPTY(&rs->rs_dlcs)) {
402 		dlc = LIST_FIRST(&rs->rs_dlcs);
403 
404 		rfcomm_dlc_close(dlc, err);
405 	}
406 
407 	rfcomm_session_free(rs);
408 }
409 
410 static void *
411 rfcomm_session_newconn(void *arg, struct sockaddr_bt *laddr,
412 				struct sockaddr_bt *raddr)
413 {
414 	struct rfcomm_session *new, *rs = arg;
415 
416 	DPRINTF("New Connection\n");
417 
418 	/*
419 	 * Incoming session connect request. We should return a new
420 	 * session pointer if this is acceptable. The L2CAP layer
421 	 * passes local and remote addresses, which we must check as
422 	 * only one RFCOMM session is allowed between any two devices
423 	 */
424 	new = rfcomm_session_lookup(laddr, raddr);
425 	if (new != NULL)
426 		return NULL;
427 
428 	new = rfcomm_session_alloc(&rfcomm_session_active, laddr);
429 	if (new == NULL)
430 		return NULL;
431 
432 	new->rs_mtu = rs->rs_mtu;
433 	new->rs_state = RFCOMM_SESSION_WAIT_CONNECT;
434 
435 	/*
436 	 * schedule an expiry so that if nothing comes of it we
437 	 * can punt.
438 	 */
439 	callout_schedule(&new->rs_timeout, rfcomm_mcc_timeout * hz);
440 
441 	return new->rs_l2cap;
442 }
443 
444 static void
445 rfcomm_session_complete(void *arg, int count)
446 {
447 	struct rfcomm_session *rs = arg;
448 	struct rfcomm_credit *credit;
449 	struct rfcomm_dlc *dlc;
450 
451 	/*
452 	 * count L2CAP packets are 'complete', meaning that they are cleared
453 	 * our buffers (for best effort) or arrived safe (for guaranteed) so
454 	 * we can take it off our list and pass the message on, so that
455 	 * eventually the data can be removed from the sockbuf
456 	 */
457 	while (count-- > 0) {
458 		credit = SIMPLEQ_FIRST(&rs->rs_credits);
459 		if (credit == NULL) {
460 			printf("%s: too many packets completed!\n", __func__);
461 			break;
462 		}
463 
464 		dlc = credit->rc_dlc;
465 		if (dlc != NULL) {
466 			dlc->rd_pending--;
467 			(*dlc->rd_proto->complete)
468 					(dlc->rd_upper, credit->rc_len);
469 
470 			/*
471 			 * if not using credit flow control, we may push
472 			 * more data now
473 			 */
474 			if ((rs->rs_flags & RFCOMM_SESSION_CFC) == 0
475 			    && dlc->rd_state == RFCOMM_DLC_OPEN) {
476 				rfcomm_dlc_start(dlc);
477 			}
478 
479 			/*
480 			 * When shutdown is indicated, we are just waiting to
481 			 * clear outgoing data.
482 			 */
483 			if ((dlc->rd_flags & RFCOMM_DLC_SHUTDOWN)
484 			    && dlc->rd_txbuf == NULL && dlc->rd_pending == 0) {
485 				dlc->rd_state = RFCOMM_DLC_WAIT_DISCONNECT;
486 				rfcomm_session_send_frame(rs, RFCOMM_FRAME_DISC,
487 							    dlc->rd_dlci);
488 				callout_schedule(&dlc->rd_timeout,
489 						    rfcomm_ack_timeout * hz);
490 			}
491 		}
492 
493 		SIMPLEQ_REMOVE_HEAD(&rs->rs_credits, rc_next);
494 		pool_put(&rfcomm_credit_pool, credit);
495 	}
496 
497 	/*
498 	 * If session is closed, we are just waiting to clear the queue
499 	 */
500 	if (rs->rs_state == RFCOMM_SESSION_CLOSED) {
501 		if (SIMPLEQ_EMPTY(&rs->rs_credits))
502 			l2cap_disconnect(rs->rs_l2cap, 0);
503 	}
504 }
505 
506 /*
507  * Link Mode changed
508  *
509  * This is called when a mode change is complete. Proceed with connections
510  * where appropriate, or pass the new mode to any active DLCs.
511  */
512 static void
513 rfcomm_session_linkmode(void *arg, int new)
514 {
515 	struct rfcomm_session *rs = arg;
516 	struct rfcomm_dlc *dlc, *next;
517 	int err, mode = 0;
518 
519 	DPRINTF("auth %s, encrypt %s, secure %s\n",
520 		(new & L2CAP_LM_AUTH ? "on" : "off"),
521 		(new & L2CAP_LM_ENCRYPT ? "on" : "off"),
522 		(new & L2CAP_LM_SECURE ? "on" : "off"));
523 
524 	if (new & L2CAP_LM_AUTH)
525 		mode |= RFCOMM_LM_AUTH;
526 
527 	if (new & L2CAP_LM_ENCRYPT)
528 		mode |= RFCOMM_LM_ENCRYPT;
529 
530 	if (new & L2CAP_LM_SECURE)
531 		mode |= RFCOMM_LM_SECURE;
532 
533 	next = LIST_FIRST(&rs->rs_dlcs);
534 	while ((dlc = next) != NULL) {
535 		next = LIST_NEXT(dlc, rd_next);
536 
537 		switch (dlc->rd_state) {
538 		case RFCOMM_DLC_WAIT_SEND_SABM:	/* we are connecting */
539 			if ((mode & dlc->rd_mode) != dlc->rd_mode) {
540 				rfcomm_dlc_close(dlc, ECONNABORTED);
541 			} else {
542 				err = rfcomm_session_send_frame(rs,
543 					    RFCOMM_FRAME_SABM, dlc->rd_dlci);
544 				if (err) {
545 					rfcomm_dlc_close(dlc, err);
546 				} else {
547 					dlc->rd_state = RFCOMM_DLC_WAIT_RECV_UA;
548 					callout_schedule(&dlc->rd_timeout,
549 							rfcomm_ack_timeout * hz);
550 					break;
551 				}
552 			}
553 
554 			/*
555 			 * If we aborted the connection and there are no more DLCs
556 			 * on the session, it is our responsibility to disconnect.
557 			 */
558 			if (!LIST_EMPTY(&rs->rs_dlcs))
559 				break;
560 
561 			rs->rs_state = RFCOMM_SESSION_WAIT_DISCONNECT;
562 			rfcomm_session_send_frame(rs, RFCOMM_FRAME_DISC, 0);
563 			callout_schedule(&rs->rs_timeout, rfcomm_ack_timeout * hz);
564 			break;
565 
566 		case RFCOMM_DLC_WAIT_SEND_UA: /* they are connecting */
567 			if ((mode & dlc->rd_mode) != dlc->rd_mode) {
568 				rfcomm_session_send_frame(rs,
569 					    RFCOMM_FRAME_DM, dlc->rd_dlci);
570 				rfcomm_dlc_close(dlc, ECONNABORTED);
571 				break;
572 			}
573 
574 			err = rfcomm_session_send_frame(rs,
575 					    RFCOMM_FRAME_UA, dlc->rd_dlci);
576 			if (err) {
577 				rfcomm_session_send_frame(rs,
578 						RFCOMM_FRAME_DM, dlc->rd_dlci);
579 				rfcomm_dlc_close(dlc, err);
580 				break;
581 			}
582 
583 			err = rfcomm_dlc_open(dlc);
584 			if (err) {
585 				rfcomm_session_send_frame(rs,
586 						RFCOMM_FRAME_DM, dlc->rd_dlci);
587 				rfcomm_dlc_close(dlc, err);
588 				break;
589 			}
590 
591 			break;
592 
593 		case RFCOMM_DLC_WAIT_RECV_UA:
594 		case RFCOMM_DLC_OPEN: /* already established */
595 			(*dlc->rd_proto->linkmode)(dlc->rd_upper, mode);
596 			break;
597 
598 		default:
599 			break;
600 		}
601 	}
602 }
603 
604 /*
605  * Receive data from L2CAP layer for session. There is always exactly one
606  * RFCOMM frame contained in each L2CAP frame.
607  */
608 static void
609 rfcomm_session_input(void *arg, struct mbuf *m)
610 {
611 	struct rfcomm_session *rs = arg;
612 	int dlci, len, type, pf;
613 	uint8_t fcs, b;
614 
615 	KASSERT(m != NULL);
616 	KASSERT(rs != NULL);
617 
618 	/*
619 	 * UIH frames: FCS is only calculated on address and control fields
620 	 * For other frames: FCS is calculated on address, control and length
621 	 * Length may extend to two octets
622 	 */
623 	fcs = 0xff;
624 
625 	if (m->m_pkthdr.len < 4) {
626 		DPRINTF("short frame (%d), discarded\n", m->m_pkthdr.len);
627 		goto done;
628 	}
629 
630 	/* address - one octet */
631 	m_copydata(m, 0, 1, &b);
632 	m_adj(m, 1);
633 	fcs = FCS(fcs, b);
634 	dlci = RFCOMM_DLCI(b);
635 
636 	/* control - one octet */
637 	m_copydata(m, 0, 1, &b);
638 	m_adj(m, 1);
639 	fcs = FCS(fcs, b);
640 	type = RFCOMM_TYPE(b);
641 	pf = RFCOMM_PF(b);
642 
643 	/* length - may be two octets */
644 	m_copydata(m, 0, 1, &b);
645 	m_adj(m, 1);
646 	if (type != RFCOMM_FRAME_UIH)
647 		fcs = FCS(fcs, b);
648 	len = (b >> 1) & 0x7f;
649 
650 	if (RFCOMM_EA(b) == 0) {
651 		if (m->m_pkthdr.len < 2) {
652 			DPRINTF("short frame (%d, EA = 0), discarded\n",
653 				m->m_pkthdr.len);
654 			goto done;
655 		}
656 
657 		m_copydata(m, 0, 1, &b);
658 		m_adj(m, 1);
659 		if (type != RFCOMM_FRAME_UIH)
660 			fcs = FCS(fcs, b);
661 
662 		len |= (b << 7);
663 	}
664 
665 	/* FCS byte is last octet in frame */
666 	m_copydata(m, m->m_pkthdr.len - 1, 1, &b);
667 	m_adj(m, -1);
668 	fcs = FCS(fcs, b);
669 
670 	if (fcs != 0xcf) {
671 		DPRINTF("Bad FCS value (%#2.2x), frame discarded\n", fcs);
672 		goto done;
673 	}
674 
675 	DPRINTFN(10, "dlci %d, type %2.2x, len = %d\n", dlci, type, len);
676 
677 	switch (type) {
678 	case RFCOMM_FRAME_SABM:
679 		if (pf)
680 			rfcomm_session_recv_sabm(rs, dlci);
681 		break;
682 
683 	case RFCOMM_FRAME_DISC:
684 		if (pf)
685 			rfcomm_session_recv_disc(rs, dlci);
686 		break;
687 
688 	case RFCOMM_FRAME_UA:
689 		if (pf)
690 			rfcomm_session_recv_ua(rs, dlci);
691 		break;
692 
693 	case RFCOMM_FRAME_DM:
694 		rfcomm_session_recv_dm(rs, dlci);
695 		break;
696 
697 	case RFCOMM_FRAME_UIH:
698 		rfcomm_session_recv_uih(rs, dlci, pf, m, len);
699 		return;	/* (no release) */
700 
701 	default:
702 		UNKNOWN(type);
703 		break;
704 	}
705 
706 done:
707 	m_freem(m);
708 }
709 
710 /***********************************************************************
711  *
712  *	RFCOMM Session receive processing
713  */
714 
715 /*
716  * rfcomm_session_recv_sabm(rfcomm_session, dlci)
717  *
718  * Set Asyncrhonous Balanced Mode - open the channel.
719  */
720 static void
721 rfcomm_session_recv_sabm(struct rfcomm_session *rs, int dlci)
722 {
723 	struct rfcomm_dlc *dlc;
724 	int err;
725 
726 	DPRINTFN(5, "SABM(%d)\n", dlci);
727 
728 	if (dlci == 0) {	/* Open Session */
729 		rs->rs_state = RFCOMM_SESSION_OPEN;
730 		rfcomm_session_send_frame(rs, RFCOMM_FRAME_UA, 0);
731 		LIST_FOREACH(dlc, &rs->rs_dlcs, rd_next) {
732 			if (dlc->rd_state == RFCOMM_DLC_WAIT_SESSION)
733 				rfcomm_dlc_connect(dlc);
734 		}
735 		return;
736 	}
737 
738 	if (rs->rs_state != RFCOMM_SESSION_OPEN) {
739 		DPRINTF("session was not even open!\n");
740 		return;
741 	}
742 
743 	/* validate direction bit */
744 	if ((IS_INITIATOR(rs) && !RFCOMM_DIRECTION(dlci))
745 	    || (!IS_INITIATOR(rs) && RFCOMM_DIRECTION(dlci))) {
746 		DPRINTF("Invalid direction bit on DLCI\n");
747 		return;
748 	}
749 
750 	/*
751 	 * look for our DLC - this may exist if we received PN
752 	 * already, or we may have to fabricate a new one.
753 	 */
754 	dlc = rfcomm_dlc_lookup(rs, dlci);
755 	if (dlc == NULL) {
756 		dlc = rfcomm_dlc_newconn(rs, dlci);
757 		if (dlc == NULL)
758 			return;	/* (DM is sent) */
759 	}
760 
761 	/*
762 	 * ..but if this DLC is not waiting to connect, they did
763 	 * something wrong, ignore it.
764 	 */
765 	if (dlc->rd_state != RFCOMM_DLC_WAIT_CONNECT)
766 		return;
767 
768 	/* set link mode */
769 	err = rfcomm_dlc_setmode(dlc);
770 	if (err == EINPROGRESS) {
771 		dlc->rd_state = RFCOMM_DLC_WAIT_SEND_UA;
772 		(*dlc->rd_proto->connecting)(dlc->rd_upper);
773 		return;
774 	}
775 	if (err)
776 		goto close;
777 
778 	err = rfcomm_session_send_frame(rs, RFCOMM_FRAME_UA, dlci);
779 	if (err)
780 		goto close;
781 
782 	/* and mark it open */
783 	err = rfcomm_dlc_open(dlc);
784 	if (err)
785 		goto close;
786 
787 	return;
788 
789 close:
790 	rfcomm_dlc_close(dlc, err);
791 }
792 
793 /*
794  * Receive Disconnect Command
795  */
796 static void
797 rfcomm_session_recv_disc(struct rfcomm_session *rs, int dlci)
798 {
799 	struct rfcomm_dlc *dlc;
800 
801 	DPRINTFN(5, "DISC(%d)\n", dlci);
802 
803 	if (dlci == 0) {
804 		/*
805 		 * Disconnect Session
806 		 *
807 		 * We set the session state to CLOSED so that when
808 		 * the UA frame is clear the session will be closed
809 		 * automatically. We wont bother to close any DLC's
810 		 * just yet as there should be none. In the unlikely
811 		 * event that something is left, it will get flushed
812 		 * out as the session goes down.
813 		 */
814 		rfcomm_session_send_frame(rs, RFCOMM_FRAME_UA, 0);
815 		rs->rs_state = RFCOMM_SESSION_CLOSED;
816 		return;
817 	}
818 
819 	dlc = rfcomm_dlc_lookup(rs, dlci);
820 	if (dlc == NULL) {
821 		rfcomm_session_send_frame(rs, RFCOMM_FRAME_DM, dlci);
822 		return;
823 	}
824 
825 	rfcomm_dlc_close(dlc, 0);
826 	rfcomm_session_send_frame(rs, RFCOMM_FRAME_UA, dlci);
827 }
828 
829 /*
830  * Receive Unnumbered Acknowledgement Response
831  *
832  * This should be a response to a DISC or SABM frame that we
833  * have previously sent. If unexpected, ignore it.
834  */
835 static void
836 rfcomm_session_recv_ua(struct rfcomm_session *rs, int dlci)
837 {
838 	struct rfcomm_dlc *dlc;
839 
840 	DPRINTFN(5, "UA(%d)\n", dlci);
841 
842 	if (dlci == 0) {
843 		switch (rs->rs_state) {
844 		case RFCOMM_SESSION_WAIT_CONNECT:	/* We sent SABM */
845 			callout_stop(&rs->rs_timeout);
846 			rs->rs_state = RFCOMM_SESSION_OPEN;
847 			LIST_FOREACH(dlc, &rs->rs_dlcs, rd_next) {
848 				if (dlc->rd_state == RFCOMM_DLC_WAIT_SESSION)
849 					rfcomm_dlc_connect(dlc);
850 			}
851 			break;
852 
853 		case RFCOMM_SESSION_WAIT_DISCONNECT:	/* We sent DISC */
854 			callout_stop(&rs->rs_timeout);
855 			rs->rs_state = RFCOMM_SESSION_CLOSED;
856 			l2cap_disconnect(rs->rs_l2cap, 0);
857 			break;
858 
859 		default:
860 			DPRINTF("Received spurious UA(0)!\n");
861 			break;
862 		}
863 
864 		return;
865 	}
866 
867 	/*
868 	 * If we have no DLC on this dlci, we may have aborted
869 	 * without shutting down properly, so check if the session
870 	 * needs disconnecting.
871 	 */
872 	dlc = rfcomm_dlc_lookup(rs, dlci);
873 	if (dlc == NULL)
874 		goto check;
875 
876 	switch (dlc->rd_state) {
877 	case RFCOMM_DLC_WAIT_RECV_UA:		/* We sent SABM */
878 		rfcomm_dlc_open(dlc);
879 		return;
880 
881 	case RFCOMM_DLC_WAIT_DISCONNECT:	/* We sent DISC */
882 		rfcomm_dlc_close(dlc, 0);
883 		break;
884 
885 	default:
886 		DPRINTF("Received spurious UA(%d)!\n", dlci);
887 		return;
888 	}
889 
890 check:	/* last one out turns out the light */
891 	if (LIST_EMPTY(&rs->rs_dlcs)) {
892 		rs->rs_state = RFCOMM_SESSION_WAIT_DISCONNECT;
893 		rfcomm_session_send_frame(rs, RFCOMM_FRAME_DISC, 0);
894 		callout_schedule(&rs->rs_timeout, rfcomm_ack_timeout * hz);
895 	}
896 }
897 
898 /*
899  * Receive Disconnected Mode Response
900  *
901  * If this does not apply to a known DLC then we may ignore it.
902  */
903 static void
904 rfcomm_session_recv_dm(struct rfcomm_session *rs, int dlci)
905 {
906 	struct rfcomm_dlc *dlc;
907 
908 	DPRINTFN(5, "DM(%d)\n", dlci);
909 
910 	dlc = rfcomm_dlc_lookup(rs, dlci);
911 	if (dlc == NULL)
912 		return;
913 
914 	if (dlc->rd_state == RFCOMM_DLC_WAIT_CONNECT)
915 		rfcomm_dlc_close(dlc, ECONNREFUSED);
916 	else
917 		rfcomm_dlc_close(dlc, ECONNRESET);
918 }
919 
920 /*
921  * Receive Unnumbered Information with Header check (MCC or data packet)
922  */
923 static void
924 rfcomm_session_recv_uih(struct rfcomm_session *rs, int dlci,
925 			int pf, struct mbuf *m, int len)
926 {
927 	struct rfcomm_dlc *dlc;
928 	uint8_t credits = 0;
929 
930 	DPRINTFN(10, "UIH(%d)\n", dlci);
931 
932 	if (dlci == 0) {
933 		rfcomm_session_recv_mcc(rs, m);
934 		return;
935 	}
936 
937 	if (m->m_pkthdr.len != len + pf) {
938 		DPRINTF("Bad Frame Length (%d), frame discarded\n",
939 			    m->m_pkthdr.len);
940 
941 		goto discard;
942 	}
943 
944 	dlc = rfcomm_dlc_lookup(rs, dlci);
945 	if (dlc == NULL) {
946 		DPRINTF("UIH received for non existent DLC, discarded\n");
947 		rfcomm_session_send_frame(rs, RFCOMM_FRAME_DM, dlci);
948 		goto discard;
949 	}
950 
951 	if (dlc->rd_state != RFCOMM_DLC_OPEN) {
952 		DPRINTF("non-open DLC (state = %d), discarded\n",
953 				dlc->rd_state);
954 		goto discard;
955 	}
956 
957 	/* if PF is set, credits were included */
958 	if (rs->rs_flags & RFCOMM_SESSION_CFC) {
959 		if (pf != 0) {
960 			if (m->m_pkthdr.len < sizeof(credits)) {
961 				DPRINTF("Bad PF value, UIH discarded\n");
962 				goto discard;
963 			}
964 
965 			m_copydata(m, 0, sizeof(credits), &credits);
966 			m_adj(m, sizeof(credits));
967 
968 			dlc->rd_txcred += credits;
969 
970 			if (credits > 0 && dlc->rd_txbuf != NULL)
971 				rfcomm_dlc_start(dlc);
972 		}
973 
974 		if (len == 0)
975 			goto discard;
976 
977 		if (dlc->rd_rxcred == 0) {
978 			DPRINTF("Credit limit reached, UIH discarded\n");
979 			goto discard;
980 		}
981 
982 		if (len > dlc->rd_rxsize) {
983 			DPRINTF("UIH frame exceeds rxsize, discarded\n");
984 			goto discard;
985 		}
986 
987 		dlc->rd_rxcred--;
988 		dlc->rd_rxsize -= len;
989 	}
990 
991 	(*dlc->rd_proto->input)(dlc->rd_upper, m);
992 	return;
993 
994 discard:
995 	m_freem(m);
996 }
997 
998 /*
999  * Receive Multiplexer Control Command
1000  */
1001 static void
1002 rfcomm_session_recv_mcc(struct rfcomm_session *rs, struct mbuf *m)
1003 {
1004 	int type, cr, len;
1005 	uint8_t b;
1006 
1007 	/*
1008 	 * Extract MCC header.
1009 	 *
1010 	 * Fields are variable length using extension bit = 1 to signify the
1011 	 * last octet in the sequence.
1012 	 *
1013 	 * Only single octet types are defined in TS 07.10/RFCOMM spec
1014 	 *
1015 	 * Length can realistically only use 15 bits (max RFCOMM MTU)
1016 	 */
1017 	if (m->m_pkthdr.len < sizeof(b)) {
1018 		DPRINTF("Short MCC header, discarded\n");
1019 		goto release;
1020 	}
1021 
1022 	m_copydata(m, 0, sizeof(b), &b);
1023 	m_adj(m, sizeof(b));
1024 
1025 	if (RFCOMM_EA(b) == 0) {	/* verify no extensions */
1026 		DPRINTF("MCC type EA = 0, discarded\n");
1027 		goto release;
1028 	}
1029 
1030 	type = RFCOMM_MCC_TYPE(b);
1031 	cr = RFCOMM_CR(b);
1032 
1033 	len = 0;
1034 	do {
1035 		if (m->m_pkthdr.len < sizeof(b)) {
1036 			DPRINTF("Short MCC header, discarded\n");
1037 			goto release;
1038 		}
1039 
1040 		m_copydata(m, 0, sizeof(b), &b);
1041 		m_adj(m, sizeof(b));
1042 
1043 		len = (len << 7) | (b >> 1);
1044 		len = min(len, RFCOMM_MTU_MAX);
1045 	} while (RFCOMM_EA(b) == 0);
1046 
1047 	if (len != m->m_pkthdr.len) {
1048 		DPRINTF("Incorrect MCC length, discarded\n");
1049 		goto release;
1050 	}
1051 
1052 	DPRINTFN(2, "MCC %s type %2.2x (%d bytes)\n",
1053 		(cr ? "command" : "response"), type, len);
1054 
1055 	/*
1056 	 * pass to command handler
1057 	 */
1058 	switch(type) {
1059 	case RFCOMM_MCC_TEST:	/* Test */
1060 		rfcomm_session_recv_mcc_test(rs, cr, m);
1061 		break;
1062 
1063 	case RFCOMM_MCC_FCON:	/* Flow Control On */
1064 		rfcomm_session_recv_mcc_fcon(rs, cr);
1065 		break;
1066 
1067 	case RFCOMM_MCC_FCOFF:	/* Flow Control Off */
1068 		rfcomm_session_recv_mcc_fcoff(rs, cr);
1069 		break;
1070 
1071 	case RFCOMM_MCC_MSC:	/* Modem Status Command */
1072 		rfcomm_session_recv_mcc_msc(rs, cr, m);
1073 		break;
1074 
1075 	case RFCOMM_MCC_RPN:	/* Remote Port Negotiation */
1076 		rfcomm_session_recv_mcc_rpn(rs, cr, m);
1077 		break;
1078 
1079 	case RFCOMM_MCC_RLS:	/* Remote Line Status */
1080 		rfcomm_session_recv_mcc_rls(rs, cr, m);
1081 		break;
1082 
1083 	case RFCOMM_MCC_PN:	/* Parameter Negotiation */
1084 		rfcomm_session_recv_mcc_pn(rs, cr, m);
1085 		break;
1086 
1087 	case RFCOMM_MCC_NSC:	/* Non Supported Command */
1088 		rfcomm_session_recv_mcc_nsc(rs, cr, m);
1089 		break;
1090 
1091 	default:
1092 		b = RFCOMM_MKMCC_TYPE(cr, type);
1093 		rfcomm_session_send_mcc(rs, 0, RFCOMM_MCC_NSC, &b, sizeof(b));
1094 	}
1095 
1096 release:
1097 	m_freem(m);
1098 }
1099 
1100 /*
1101  * process TEST command/response
1102  */
1103 static void
1104 rfcomm_session_recv_mcc_test(struct rfcomm_session *rs, int cr, struct mbuf *m)
1105 {
1106 	void *data;
1107 	int len;
1108 
1109 	if (cr == 0)	/* ignore ack */
1110 		return;
1111 
1112 	/*
1113 	 * we must send all the data they included back as is
1114 	 */
1115 
1116 	len = m->m_pkthdr.len;
1117 	if (len > RFCOMM_MTU_MAX)
1118 		return;
1119 
1120 	data = malloc(len, M_BLUETOOTH, M_NOWAIT);
1121 	if (data == NULL)
1122 		return;
1123 
1124 	m_copydata(m, 0, len, data);
1125 	rfcomm_session_send_mcc(rs, 0, RFCOMM_MCC_TEST, data, len);
1126 	free(data, M_BLUETOOTH);
1127 }
1128 
1129 /*
1130  * process Flow Control ON command/response
1131  */
1132 static void
1133 rfcomm_session_recv_mcc_fcon(struct rfcomm_session *rs, int cr)
1134 {
1135 
1136 	if (cr == 0)	/* ignore ack */
1137 		return;
1138 
1139 	rs->rs_flags |= RFCOMM_SESSION_RFC;
1140 	rfcomm_session_send_mcc(rs, 0, RFCOMM_MCC_FCON, NULL, 0);
1141 }
1142 
1143 /*
1144  * process Flow Control OFF command/response
1145  */
1146 static void
1147 rfcomm_session_recv_mcc_fcoff(struct rfcomm_session *rs, int cr)
1148 {
1149 
1150 	if (cr == 0)	/* ignore ack */
1151 		return;
1152 
1153 	rs->rs_flags &= ~RFCOMM_SESSION_RFC;
1154 	rfcomm_session_send_mcc(rs, 0, RFCOMM_MCC_FCOFF, NULL, 0);
1155 }
1156 
1157 /*
1158  * process Modem Status Command command/response
1159  */
1160 static void
1161 rfcomm_session_recv_mcc_msc(struct rfcomm_session *rs, int cr, struct mbuf *m)
1162 {
1163 	struct rfcomm_mcc_msc msc;	/* (3 octets) */
1164 	struct rfcomm_dlc *dlc;
1165 	int len = 0;
1166 
1167 	/* [ADDRESS] */
1168 	if (m->m_pkthdr.len < sizeof(msc.address))
1169 		return;
1170 
1171 	m_copydata(m, 0, sizeof(msc.address), &msc.address);
1172 	m_adj(m, sizeof(msc.address));
1173 	len += sizeof(msc.address);
1174 
1175 	dlc = rfcomm_dlc_lookup(rs, RFCOMM_DLCI(msc.address));
1176 
1177 	if (cr == 0) {	/* ignore acks */
1178 		if (dlc != NULL)
1179 			callout_stop(&dlc->rd_timeout);
1180 
1181 		return;
1182 	}
1183 
1184 	if (dlc == NULL) {
1185 		rfcomm_session_send_frame(rs, RFCOMM_FRAME_DM,
1186 						RFCOMM_DLCI(msc.address));
1187 		return;
1188 	}
1189 
1190 	/* [SIGNALS] */
1191 	if (m->m_pkthdr.len < sizeof(msc.modem))
1192 		return;
1193 
1194 	m_copydata(m, 0, sizeof(msc.modem), &msc.modem);
1195 	m_adj(m, sizeof(msc.modem));
1196 	len += sizeof(msc.modem);
1197 
1198 	dlc->rd_rmodem = msc.modem;
1199 	/* XXX how do we signal this upstream? */
1200 
1201 	if (RFCOMM_EA(msc.modem) == 0) {
1202 		if (m->m_pkthdr.len < sizeof(msc.brk))
1203 			return;
1204 
1205 		m_copydata(m, 0, sizeof(msc.brk), &msc.brk);
1206 		m_adj(m, sizeof(msc.brk));
1207 		len += sizeof(msc.brk);
1208 
1209 		/* XXX how do we signal this upstream? */
1210 	}
1211 
1212 	rfcomm_session_send_mcc(rs, 0, RFCOMM_MCC_MSC, &msc, len);
1213 }
1214 
1215 /*
1216  * process Remote Port Negotiation command/response
1217  */
1218 static void
1219 rfcomm_session_recv_mcc_rpn(struct rfcomm_session *rs, int cr, struct mbuf *m)
1220 {
1221 	struct rfcomm_mcc_rpn rpn;
1222 	uint16_t mask;
1223 
1224 	if (cr == 0)	/* ignore ack */
1225 		return;
1226 
1227 	/* default values */
1228 	rpn.bit_rate = RFCOMM_RPN_BR_9600;
1229 	rpn.line_settings = RFCOMM_RPN_8_N_1;
1230 	rpn.flow_control = RFCOMM_RPN_FLOW_NONE;
1231 	rpn.xon_char = RFCOMM_RPN_XON_CHAR;
1232 	rpn.xoff_char = RFCOMM_RPN_XOFF_CHAR;
1233 
1234 	if (m->m_pkthdr.len == sizeof(rpn)) {
1235 		m_copydata(m, 0, sizeof(rpn), &rpn);
1236 		rpn.param_mask = RFCOMM_RPN_PM_ALL;
1237 	} else if (m->m_pkthdr.len == 1) {
1238 		m_copydata(m, 0, 1, &rpn);
1239 		rpn.param_mask = le16toh(rpn.param_mask);
1240 	} else {
1241 		DPRINTF("Bad RPN length (%d)\n", m->m_pkthdr.len);
1242 		return;
1243 	}
1244 
1245 	mask = 0;
1246 
1247 	if (rpn.param_mask & RFCOMM_RPN_PM_RATE)
1248 		mask |= RFCOMM_RPN_PM_RATE;
1249 
1250 	if (rpn.param_mask & RFCOMM_RPN_PM_DATA
1251 	    && RFCOMM_RPN_DATA_BITS(rpn.line_settings) == RFCOMM_RPN_DATA_8)
1252 		mask |= RFCOMM_RPN_PM_DATA;
1253 
1254 	if (rpn.param_mask & RFCOMM_RPN_PM_STOP
1255 	    && RFCOMM_RPN_STOP_BITS(rpn.line_settings) == RFCOMM_RPN_STOP_1)
1256 		mask |= RFCOMM_RPN_PM_STOP;
1257 
1258 	if (rpn.param_mask & RFCOMM_RPN_PM_PARITY
1259 	    && RFCOMM_RPN_PARITY(rpn.line_settings) == RFCOMM_RPN_PARITY_NONE)
1260 		mask |= RFCOMM_RPN_PM_PARITY;
1261 
1262 	if (rpn.param_mask & RFCOMM_RPN_PM_XON
1263 	    && rpn.xon_char == RFCOMM_RPN_XON_CHAR)
1264 		mask |= RFCOMM_RPN_PM_XON;
1265 
1266 	if (rpn.param_mask & RFCOMM_RPN_PM_XOFF
1267 	    && rpn.xoff_char == RFCOMM_RPN_XOFF_CHAR)
1268 		mask |= RFCOMM_RPN_PM_XOFF;
1269 
1270 	if (rpn.param_mask & RFCOMM_RPN_PM_FLOW
1271 	    && rpn.flow_control == RFCOMM_RPN_FLOW_NONE)
1272 		mask |= RFCOMM_RPN_PM_FLOW;
1273 
1274 	rpn.param_mask = htole16(mask);
1275 
1276 	rfcomm_session_send_mcc(rs, 0, RFCOMM_MCC_RPN, &rpn, sizeof(rpn));
1277 }
1278 
1279 /*
1280  * process Remote Line Status command/response
1281  */
1282 static void
1283 rfcomm_session_recv_mcc_rls(struct rfcomm_session *rs, int cr, struct mbuf *m)
1284 {
1285 	struct rfcomm_mcc_rls rls;
1286 
1287 	if (cr == 0)	/* ignore ack */
1288 		return;
1289 
1290 	if (m->m_pkthdr.len != sizeof(rls)) {
1291 		DPRINTF("Bad RLS length %d\n", m->m_pkthdr.len);
1292 		return;
1293 	}
1294 
1295 	m_copydata(m, 0, sizeof(rls), &rls);
1296 
1297 	/*
1298 	 * So far as I can tell, we just send back what
1299 	 * they sent us. This signifies errors that seem
1300 	 * irrelevent for RFCOMM over L2CAP.
1301 	 */
1302 	rls.address |= 0x03;	/* EA = 1, CR = 1 */
1303 	rls.status &= 0x0f;	/* only 4 bits valid */
1304 
1305 	rfcomm_session_send_mcc(rs, 0, RFCOMM_MCC_RLS, &rls, sizeof(rls));
1306 }
1307 
1308 /*
1309  * process Parameter Negotiation command/response
1310  */
1311 static void
1312 rfcomm_session_recv_mcc_pn(struct rfcomm_session *rs, int cr, struct mbuf *m)
1313 {
1314 	struct rfcomm_dlc *dlc;
1315 	struct rfcomm_mcc_pn pn;
1316 	int err;
1317 
1318 	if (m->m_pkthdr.len != sizeof(pn)) {
1319 		DPRINTF("Bad PN length %d\n", m->m_pkthdr.len);
1320 		return;
1321 	}
1322 
1323 	m_copydata(m, 0, sizeof(pn), &pn);
1324 
1325 	pn.dlci &= 0x3f;
1326 	pn.mtu = le16toh(pn.mtu);
1327 
1328 	dlc = rfcomm_dlc_lookup(rs, pn.dlci);
1329 	if (cr) {	/* Command */
1330 		/*
1331 		 * If there is no DLC present, this is a new
1332 		 * connection so attempt to make one
1333 		 */
1334 		if (dlc == NULL) {
1335 			dlc = rfcomm_dlc_newconn(rs, pn.dlci);
1336 			if (dlc == NULL)
1337 				return;	/* (DM is sent) */
1338 		}
1339 
1340 		/* accept any valid MTU, and offer it back */
1341 		pn.mtu = min(pn.mtu, RFCOMM_MTU_MAX);
1342 		pn.mtu = min(pn.mtu, rs->rs_mtu);
1343 		pn.mtu = max(pn.mtu, RFCOMM_MTU_MIN);
1344 		dlc->rd_mtu = pn.mtu;
1345 		pn.mtu = htole16(pn.mtu);
1346 
1347 		/* credits are only set before DLC is open */
1348 		if (dlc->rd_state == RFCOMM_DLC_WAIT_CONNECT
1349 		    && (pn.flow_control & 0xf0) == 0xf0) {
1350 			rs->rs_flags |= RFCOMM_SESSION_CFC;
1351 			dlc->rd_txcred = pn.credits & 0x07;
1352 
1353 			dlc->rd_rxcred = (dlc->rd_rxsize / dlc->rd_mtu);
1354 			dlc->rd_rxcred = min(dlc->rd_rxcred,
1355 						RFCOMM_CREDITS_DEFAULT);
1356 
1357 			pn.flow_control = 0xe0;
1358 			pn.credits = dlc->rd_rxcred;
1359 		} else {
1360 			pn.flow_control = 0x00;
1361 			pn.credits = 0x00;
1362 		}
1363 
1364 		/* unused fields must be ignored and set to zero */
1365 		pn.ack_timer = 0;
1366 		pn.max_retrans = 0;
1367 
1368 		/* send our response */
1369 		err = rfcomm_session_send_mcc(rs, 0,
1370 					RFCOMM_MCC_PN, &pn, sizeof(pn));
1371 		if (err)
1372 			goto close;
1373 
1374 	} else {	/* Response */
1375 		/* ignore responses with no matching DLC */
1376 		if (dlc == NULL)
1377 			return;
1378 
1379 		callout_stop(&dlc->rd_timeout);
1380 
1381 		/* reject invalid or unacceptable MTU */
1382 		if (pn.mtu < RFCOMM_MTU_MIN || pn.mtu > dlc->rd_mtu) {
1383 			dlc->rd_state = RFCOMM_DLC_WAIT_DISCONNECT;
1384 			err = rfcomm_session_send_frame(rs, RFCOMM_FRAME_DISC,
1385 							pn.dlci);
1386 			if (err)
1387 				goto close;
1388 
1389 			callout_schedule(&dlc->rd_timeout,
1390 					    rfcomm_ack_timeout * hz);
1391 			return;
1392 		}
1393 		dlc->rd_mtu = pn.mtu;
1394 
1395 		/* if DLC is not waiting to connect, we are done */
1396 		if (dlc->rd_state != RFCOMM_DLC_WAIT_CONNECT)
1397 			return;
1398 
1399 		/* set initial credits according to RFCOMM spec */
1400 		if ((pn.flow_control & 0xf0) == 0xe0) {
1401 			rs->rs_flags |= RFCOMM_SESSION_CFC;
1402 			dlc->rd_txcred = (pn.credits & 0x07);
1403 		}
1404 
1405 		callout_schedule(&dlc->rd_timeout, rfcomm_ack_timeout * hz);
1406 
1407 		/* set link mode */
1408 		err = rfcomm_dlc_setmode(dlc);
1409 		if (err == EINPROGRESS) {
1410 			dlc->rd_state = RFCOMM_DLC_WAIT_SEND_SABM;
1411 			(*dlc->rd_proto->connecting)(dlc->rd_upper);
1412 			return;
1413 		}
1414 		if (err)
1415 			goto close;
1416 
1417 		/* we can proceed now */
1418 		err = rfcomm_session_send_frame(rs, RFCOMM_FRAME_SABM, pn.dlci);
1419 		if (err)
1420 			goto close;
1421 
1422 		dlc->rd_state = RFCOMM_DLC_WAIT_RECV_UA;
1423 	}
1424 	return;
1425 
1426 close:
1427 	rfcomm_dlc_close(dlc, err);
1428 }
1429 
1430 /*
1431  * process Non Supported Command command/response
1432  */
1433 static void
1434 rfcomm_session_recv_mcc_nsc(struct rfcomm_session *rs,
1435     int cr, struct mbuf *m)
1436 {
1437 	struct rfcomm_dlc *dlc, *next;
1438 
1439 	/*
1440 	 * Since we did nothing that is not mandatory,
1441 	 * we just abort the whole session..
1442 	 */
1443 
1444 	next = LIST_FIRST(&rs->rs_dlcs);
1445 	while ((dlc = next) != NULL) {
1446 		next = LIST_NEXT(dlc, rd_next);
1447 		rfcomm_dlc_close(dlc, ECONNABORTED);
1448 	}
1449 
1450 	rfcomm_session_free(rs);
1451 }
1452 
1453 /***********************************************************************
1454  *
1455  *	RFCOMM Session outward frame/uih/mcc building
1456  */
1457 
1458 /*
1459  * SABM/DISC/DM/UA frames are all minimal and mostly identical.
1460  */
1461 int
1462 rfcomm_session_send_frame(struct rfcomm_session *rs, int type, int dlci)
1463 {
1464 	struct rfcomm_cmd_hdr *hdr;
1465 	struct rfcomm_credit *credit;
1466 	struct mbuf *m;
1467 	uint8_t fcs, cr;
1468 
1469 	credit = pool_get(&rfcomm_credit_pool, PR_NOWAIT);
1470 	if (credit == NULL)
1471 		return ENOMEM;
1472 
1473 	m = m_gethdr(M_DONTWAIT, MT_DATA);
1474 	if (m == NULL) {
1475 		pool_put(&rfcomm_credit_pool, credit);
1476 		return ENOMEM;
1477 	}
1478 
1479 	/*
1480 	 * The CR (command/response) bit identifies the frame either as a
1481 	 * commmand or a response and is used along with the DLCI to form
1482 	 * the address. Commands contain the non-initiator address, whereas
1483 	 * responses contain the initiator address, so the CR value is
1484 	 * also dependent on the session direction.
1485 	 */
1486 	if (type == RFCOMM_FRAME_UA || type == RFCOMM_FRAME_DM)
1487 		cr = IS_INITIATOR(rs) ? 0 : 1;
1488 	else
1489 		cr = IS_INITIATOR(rs) ? 1 : 0;
1490 
1491 	hdr = mtod(m, struct rfcomm_cmd_hdr *);
1492 	hdr->address = RFCOMM_MKADDRESS(cr, dlci);
1493 	hdr->control = RFCOMM_MKCONTROL(type, 1);   /* PF = 1 */
1494 	hdr->length = (0x00 << 1) | 0x01;	    /* len = 0x00, EA = 1 */
1495 
1496 	fcs = 0xff;
1497 	fcs = FCS(fcs, hdr->address);
1498 	fcs = FCS(fcs, hdr->control);
1499 	fcs = FCS(fcs, hdr->length);
1500 	fcs = 0xff - fcs;	/* ones complement */
1501 	hdr->fcs = fcs;
1502 
1503 	m->m_pkthdr.len = m->m_len = sizeof(struct rfcomm_cmd_hdr);
1504 
1505 	/* empty credit note */
1506 	credit->rc_dlc = NULL;
1507 	credit->rc_len = m->m_pkthdr.len;
1508 	SIMPLEQ_INSERT_TAIL(&rs->rs_credits, credit, rc_next);
1509 
1510 	DPRINTFN(5, "dlci %d type %2.2x (%d bytes, fcs=%#2.2x)\n",
1511 		dlci, type, m->m_pkthdr.len, fcs);
1512 
1513 	return l2cap_send(rs->rs_l2cap, m);
1514 }
1515 
1516 /*
1517  * rfcomm_session_send_uih(rfcomm_session, rfcomm_dlc, credits, mbuf)
1518  *
1519  * UIH frame is per DLC data or Multiplexer Control Commands
1520  * when no DLC is given. Data mbuf is optional (just credits
1521  * will be sent in that case)
1522  */
1523 int
1524 rfcomm_session_send_uih(struct rfcomm_session *rs, struct rfcomm_dlc *dlc,
1525 			int credits, struct mbuf *m)
1526 {
1527 	struct rfcomm_credit *credit;
1528 	struct mbuf *m0 = NULL;
1529 	int err, len;
1530 	uint8_t fcs, *hdr;
1531 
1532 	KASSERT(rs != NULL);
1533 
1534 	len = (m == NULL) ? 0 : m->m_pkthdr.len;
1535 	KASSERT(!(credits == 0 && len == 0));
1536 
1537 	/*
1538 	 * Make a credit note for the completion notification
1539 	 */
1540 	credit = pool_get(&rfcomm_credit_pool, PR_NOWAIT);
1541 	if (credit == NULL)
1542 		goto nomem;
1543 
1544 	credit->rc_len = len;
1545 	credit->rc_dlc = dlc;
1546 
1547 	/*
1548 	 * Wrap UIH frame information around payload.
1549 	 *
1550 	 * [ADDRESS] [CONTROL] [LENGTH] [CREDITS] [...] [FCS]
1551 	 *
1552 	 * Address is one octet.
1553 	 * Control is one octet.
1554 	 * Length is one or two octets.
1555 	 * Credits may be one octet.
1556 	 *
1557 	 * FCS is one octet and calculated on address and
1558 	 *	control octets only.
1559 	 *
1560 	 * If there are credits to be sent, we will set the PF
1561 	 * flag and include them in the frame.
1562 	 */
1563 	m0 = m_gethdr(M_DONTWAIT, MT_DATA);
1564 	if (m0 == NULL)
1565 		goto nomem;
1566 
1567 	MH_ALIGN(m0, 5);	/* (max 5 header octets) */
1568 	hdr = mtod(m0, uint8_t *);
1569 
1570 	/* CR bit is set according to the initiator of the session */
1571 	*hdr = RFCOMM_MKADDRESS((IS_INITIATOR(rs) ? 1 : 0),
1572 				(dlc ? dlc->rd_dlci : 0));
1573 	fcs = FCS(0xff, *hdr);
1574 	hdr++;
1575 
1576 	/* PF bit is set if credits are being sent */
1577 	*hdr = RFCOMM_MKCONTROL(RFCOMM_FRAME_UIH, (credits > 0 ? 1 : 0));
1578 	fcs = FCS(fcs, *hdr);
1579 	hdr++;
1580 
1581 	if (len < (1 << 7)) {
1582 		*hdr++ = ((len << 1) & 0xfe) | 0x01;	/* 7 bits, EA = 1 */
1583 	} else {
1584 		*hdr++ = ((len << 1) & 0xfe);		/* 7 bits, EA = 0 */
1585 		*hdr++ = ((len >> 7) & 0xff);		/* 8 bits, no EA */
1586 	}
1587 
1588 	if (credits > 0)
1589 		*hdr++ = (uint8_t)credits;
1590 
1591 	m0->m_len = hdr - mtod(m0, uint8_t *);
1592 
1593 	/* Append payload */
1594 	m0->m_next = m;
1595 	m = NULL;
1596 
1597 	m0->m_pkthdr.len = m0->m_len + len;
1598 
1599 	/* Append FCS */
1600 	fcs = 0xff - fcs;	/* ones complement */
1601 	len = m0->m_pkthdr.len;
1602 	m_copyback(m0, len, sizeof(fcs), &fcs);
1603 	if (m0->m_pkthdr.len != len + sizeof(fcs))
1604 		goto nomem;
1605 
1606 	DPRINTFN(10, "dlci %d, pktlen %d (%d data, %d credits), fcs=%#2.2x\n",
1607 		dlc ? dlc->rd_dlci : 0, m0->m_pkthdr.len, credit->rc_len,
1608 		credits, fcs);
1609 
1610 	/*
1611 	 * UIH frame ready to go..
1612 	 */
1613 	err = l2cap_send(rs->rs_l2cap, m0);
1614 	if (err)
1615 		goto fail;
1616 
1617 	SIMPLEQ_INSERT_TAIL(&rs->rs_credits, credit, rc_next);
1618 	return 0;
1619 
1620 nomem:
1621 	err = ENOMEM;
1622 
1623 	if (m0 != NULL)
1624 		m_freem(m0);
1625 
1626 	if (m != NULL)
1627 		m_freem(m);
1628 
1629 fail:
1630 	if (credit != NULL)
1631 		pool_put(&rfcomm_credit_pool, credit);
1632 
1633 	return err;
1634 }
1635 
1636 /*
1637  * send Multiplexer Control Command (or Response) on session
1638  */
1639 int
1640 rfcomm_session_send_mcc(struct rfcomm_session *rs, int cr,
1641 			uint8_t type, void *data, int len)
1642 {
1643 	struct mbuf *m;
1644 	uint8_t *hdr;
1645 	int hlen;
1646 
1647 	m = m_gethdr(M_DONTWAIT, MT_DATA);
1648 	if (m == NULL)
1649 		return ENOMEM;
1650 
1651 	hdr = mtod(m, uint8_t *);
1652 
1653 	/*
1654 	 * Technically the type field can extend past one octet, but none
1655 	 * currently defined will do that.
1656 	 */
1657 	*hdr++ = RFCOMM_MKMCC_TYPE(cr, type);
1658 
1659 	/*
1660 	 * In the frame, the max length size is 2 octets (15 bits) whereas
1661 	 * no max length size is specified for MCC commands. We must allow
1662 	 * for 3 octets since for MCC frames we use 7 bits + EA in each.
1663 	 *
1664 	 * Only test data can possibly be that big.
1665 	 *
1666 	 * XXX Should we check this against the MTU?
1667 	 */
1668 	if (len < (1 << 7)) {
1669 		*hdr++ = ((len << 1) & 0xfe) | 0x01;	/* 7 bits, EA = 1 */
1670 	} else if (len < (1 << 14)) {
1671 		*hdr++ = ((len << 1) & 0xfe);		/* 7 bits, EA = 0 */
1672 		*hdr++ = ((len >> 6) & 0xfe) | 0x01;	/* 7 bits, EA = 1 */
1673 	} else if (len < (1 << 15)) {
1674 		*hdr++ = ((len << 1) & 0xfe);		/* 7 bits, EA = 0 */
1675 		*hdr++ = ((len >> 6) & 0xfe);		/* 7 bits, EA = 0 */
1676 		*hdr++ = ((len >> 13) & 0x02) | 0x01;	/* 1 bit,  EA = 1 */
1677 	} else {
1678 		DPRINTF("incredible length! (%d)\n", len);
1679 		m_freem(m);
1680 		return EMSGSIZE;
1681 	}
1682 
1683 	/*
1684 	 * add command data (to same mbuf if possible)
1685 	 */
1686 	hlen = hdr - mtod(m, uint8_t *);
1687 
1688 	if (len > 0) {
1689 		m->m_pkthdr.len = m->m_len = MHLEN;
1690 		m_copyback(m, hlen, len, data);
1691 		if (m->m_pkthdr.len != max(MHLEN, hlen + len)) {
1692 			m_freem(m);
1693 			return ENOMEM;
1694 		}
1695 	}
1696 
1697 	m->m_pkthdr.len = hlen + len;
1698 	m->m_len = min(MHLEN, m->m_pkthdr.len);
1699 
1700 	DPRINTFN(5, "%s type %2.2x len %d\n",
1701 		(cr ? "command" : "response"), type, m->m_pkthdr.len);
1702 
1703 	return rfcomm_session_send_uih(rs, NULL, 0, m);
1704 }
1705