xref: /netbsd-src/sys/netbt/rfcomm_dlc.c (revision cac8e449158efc7261bebc8657cbb0125a2cfdde)
1 /*	$NetBSD: rfcomm_dlc.c,v 1.5 2008/04/24 11:38:37 ad 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_dlc.c,v 1.5 2008/04/24 11:38:37 ad 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/systm.h>
42 
43 #include <netbt/bluetooth.h>
44 #include <netbt/hci.h>
45 #include <netbt/l2cap.h>
46 #include <netbt/rfcomm.h>
47 
48 /*
49  * rfcomm_dlc_lookup(rfcomm_session, dlci)
50  *
51  * Find DLC on session with matching dlci
52  */
53 struct rfcomm_dlc *
54 rfcomm_dlc_lookup(struct rfcomm_session *rs, int dlci)
55 {
56 	struct rfcomm_dlc *dlc;
57 
58 	LIST_FOREACH(dlc, &rs->rs_dlcs, rd_next) {
59 		if (dlc->rd_dlci == dlci)
60 			break;
61 	}
62 
63 	return dlc;
64 }
65 
66 /*
67  * rfcomm_dlc_newconn(rfcomm_session, dlci)
68  *
69  * handle a new dlc request (since its called from a couple of places)
70  */
71 struct rfcomm_dlc *
72 rfcomm_dlc_newconn(struct rfcomm_session *rs, int dlci)
73 {
74 	struct rfcomm_session *ls;
75 	struct rfcomm_dlc *new, *dlc, *any, *best;
76 	struct sockaddr_bt laddr, raddr, addr;
77 	int chan;
78 
79 	/*
80 	 * Search amongst the listening DLC community for the best match for
81 	 * address & channel. We keep listening DLC's hanging on listening
82 	 * sessions in a last first order, so scan the entire bunch and keep
83 	 * a note of the best address and BDADDR_ANY matches in order to find
84 	 * the oldest and most specific match.
85 	 */
86 	l2cap_sockaddr(rs->rs_l2cap, &laddr);
87 	l2cap_peeraddr(rs->rs_l2cap, &raddr);
88 	chan = RFCOMM_CHANNEL(dlci);
89 	new = NULL;
90 
91 	any = best = NULL;
92 	LIST_FOREACH(ls, &rfcomm_session_listen, rs_next) {
93 		l2cap_sockaddr(ls->rs_l2cap, &addr);
94 
95 		if (addr.bt_psm != laddr.bt_psm)
96 			continue;
97 
98 		if (bdaddr_same(&laddr.bt_bdaddr, &addr.bt_bdaddr)) {
99 			LIST_FOREACH(dlc, &ls->rs_dlcs, rd_next) {
100 				if (dlc->rd_laddr.bt_channel == chan)
101 					best = dlc;
102 			}
103 		}
104 
105 		if (bdaddr_any(&addr.bt_bdaddr)) {
106 			LIST_FOREACH(dlc, &ls->rs_dlcs, rd_next) {
107 				if (dlc->rd_laddr.bt_channel == chan)
108 					any = dlc;
109 			}
110 		}
111 	}
112 
113 	dlc = best ? best : any;
114 
115 	/* XXX
116 	 * Note that if this fails, we could have missed a chance to open
117 	 * a connection - really need to rewrite the strategy for storing
118 	 * listening DLC's so all can be checked in turn..
119 	 */
120 	if (dlc != NULL)
121 		new = (*dlc->rd_proto->newconn)(dlc->rd_upper, &laddr, &raddr);
122 
123 	if (new == NULL) {
124 		rfcomm_session_send_frame(rs, RFCOMM_FRAME_DM, dlci);
125 		return NULL;
126 	}
127 
128 	new->rd_dlci = dlci;
129 	new->rd_mtu = rfcomm_mtu_default;
130 	new->rd_mode = dlc->rd_mode;
131 
132 	memcpy(&new->rd_laddr, &laddr, sizeof(struct sockaddr_bt));
133 	new->rd_laddr.bt_channel = chan;
134 
135 	memcpy(&new->rd_raddr, &raddr, sizeof(struct sockaddr_bt));
136 	new->rd_raddr.bt_channel = chan;
137 
138 	new->rd_session = rs;
139 	new->rd_state = RFCOMM_DLC_WAIT_CONNECT;
140 	LIST_INSERT_HEAD(&rs->rs_dlcs, new, rd_next);
141 
142 	return new;
143 }
144 
145 /*
146  * rfcomm_dlc_close(dlc, error)
147  *
148  * detach DLC from session and clean up
149  */
150 void
151 rfcomm_dlc_close(struct rfcomm_dlc *dlc, int err)
152 {
153 	struct rfcomm_session *rs;
154 	struct rfcomm_credit *credit;
155 
156 	KASSERT(dlc->rd_state != RFCOMM_DLC_CLOSED);
157 
158 	/* Clear credit history */
159 	rs = dlc->rd_session;
160 	SIMPLEQ_FOREACH(credit, &rs->rs_credits, rc_next)
161 		if (credit->rc_dlc == dlc)
162 			credit->rc_dlc = NULL;
163 
164 	callout_stop(&dlc->rd_timeout);
165 
166 	LIST_REMOVE(dlc, rd_next);
167 	dlc->rd_session = NULL;
168 	dlc->rd_state = RFCOMM_DLC_CLOSED;
169 
170 	(*dlc->rd_proto->disconnected)(dlc->rd_upper, err);
171 
172 	/*
173 	 * It is the responsibility of the party who sends the last
174 	 * DISC(dlci) to disconnect the session, but we will schedule
175 	 * an expiry just in case that doesnt happen..
176 	 */
177 	if (LIST_EMPTY(&rs->rs_dlcs)) {
178 		if (rs->rs_state == RFCOMM_SESSION_LISTEN)
179 			rfcomm_session_free(rs);
180 		else
181 			callout_schedule(&rs->rs_timeout,
182 					rfcomm_ack_timeout * hz);
183 	}
184 }
185 
186 /*
187  * rfcomm_dlc_timeout(dlc)
188  *
189  * DLC timeout function is schedUled when we sent any of SABM,
190  * DISC, MCC_MSC, or MCC_PN and should be cancelled when we get
191  * the relevant response. There is nothing to do but shut this
192  * DLC down.
193  */
194 void
195 rfcomm_dlc_timeout(void *arg)
196 {
197 	struct rfcomm_dlc *dlc = arg;
198 
199 	mutex_enter(bt_lock);
200 	callout_ack(&dlc->rd_timeout);
201 
202 	if (dlc->rd_state != RFCOMM_DLC_CLOSED)
203 		rfcomm_dlc_close(dlc, ETIMEDOUT);
204 	else if (dlc->rd_flags & RFCOMM_DLC_DETACH) {
205 		callout_destroy(&dlc->rd_timeout);
206 		free(dlc, M_BLUETOOTH);
207 	}
208 
209 	mutex_exit(bt_lock);
210 }
211 
212 /*
213  * rfcomm_dlc_setmode(rfcomm_dlc)
214  *
215  * Set link mode for DLC.  This is only called when the session is
216  * already open, so we don't need to worry about any previous mode
217  * settings.
218  */
219 int
220 rfcomm_dlc_setmode(struct rfcomm_dlc *dlc)
221 {
222 	int mode = 0;
223 
224 	KASSERT(dlc->rd_session != NULL);
225 	KASSERT(dlc->rd_session->rs_state == RFCOMM_SESSION_OPEN);
226 
227 	DPRINTF("dlci %d, auth %s, encrypt %s, secure %s\n", dlc->rd_dlci,
228 		(dlc->rd_mode & RFCOMM_LM_AUTH ? "yes" : "no"),
229 		(dlc->rd_mode & RFCOMM_LM_ENCRYPT ? "yes" : "no"),
230 		(dlc->rd_mode & RFCOMM_LM_SECURE ? "yes" : "no"));
231 
232 	if (dlc->rd_mode & RFCOMM_LM_AUTH)
233 		mode |= L2CAP_LM_AUTH;
234 
235 	if (dlc->rd_mode & RFCOMM_LM_ENCRYPT)
236 		mode |= L2CAP_LM_ENCRYPT;
237 
238 	if (dlc->rd_mode & RFCOMM_LM_SECURE)
239 		mode |= L2CAP_LM_SECURE;
240 
241 	return l2cap_setopt(dlc->rd_session->rs_l2cap, SO_L2CAP_LM, &mode);
242 }
243 
244 /*
245  * rfcomm_dlc_connect(rfcomm_dlc)
246  *
247  * initiate DLC connection (session is already connected)
248  */
249 int
250 rfcomm_dlc_connect(struct rfcomm_dlc *dlc)
251 {
252 	struct rfcomm_mcc_pn pn;
253 	int err = 0;
254 
255 	KASSERT(dlc->rd_session != NULL);
256 	KASSERT(dlc->rd_session->rs_state == RFCOMM_SESSION_OPEN);
257 	KASSERT(dlc->rd_state == RFCOMM_DLC_WAIT_SESSION);
258 
259 	/*
260 	 * If we have not already sent a PN on the session, we must send
261 	 * a PN to negotiate Credit Flow Control, and this setting will
262 	 * apply to all future connections for this session. We ask for
263 	 * this every time, in order to establish initial credits.
264 	 */
265 	memset(&pn, 0, sizeof(pn));
266 	pn.dlci = dlc->rd_dlci;
267 	pn.priority = dlc->rd_dlci | 0x07;
268 	pn.mtu = htole16(dlc->rd_mtu);
269 
270 	pn.flow_control = 0xf0;
271 	dlc->rd_rxcred = (dlc->rd_rxsize / dlc->rd_mtu);
272 	dlc->rd_rxcred = min(dlc->rd_rxcred, RFCOMM_CREDITS_DEFAULT);
273 	pn.credits = dlc->rd_rxcred;
274 
275 	err = rfcomm_session_send_mcc(dlc->rd_session, 1,
276 					RFCOMM_MCC_PN, &pn, sizeof(pn));
277 	if (err)
278 		return err;
279 
280 	dlc->rd_state = RFCOMM_DLC_WAIT_CONNECT;
281 	callout_schedule(&dlc->rd_timeout, rfcomm_mcc_timeout * hz);
282 
283 	return 0;
284 }
285 
286 /*
287  * rfcomm_dlc_open(rfcomm_dlc)
288  *
289  * send "Modem Status Command" and mark DLC as open.
290  */
291 int
292 rfcomm_dlc_open(struct rfcomm_dlc *dlc)
293 {
294 	struct rfcomm_mcc_msc msc;
295 	int err;
296 
297 	KASSERT(dlc->rd_session != NULL);
298 	KASSERT(dlc->rd_session->rs_state == RFCOMM_SESSION_OPEN);
299 
300 	memset(&msc, 0, sizeof(msc));
301 	msc.address = RFCOMM_MKADDRESS(1, dlc->rd_dlci);
302 	msc.modem = dlc->rd_lmodem & 0xfe;	/* EA = 0 */
303 	msc.brk =	0x00	   | 0x01;	/* EA = 1 */
304 
305 	err = rfcomm_session_send_mcc(dlc->rd_session, 1,
306 				RFCOMM_MCC_MSC, &msc, sizeof(msc));
307 	if (err)
308 		return err;
309 
310 	callout_schedule(&dlc->rd_timeout, rfcomm_mcc_timeout * hz);
311 
312 	dlc->rd_state = RFCOMM_DLC_OPEN;
313 	(*dlc->rd_proto->connected)(dlc->rd_upper);
314 
315 	return 0;
316 }
317 
318 /*
319  * rfcomm_dlc_start(rfcomm_dlc)
320  *
321  * Start sending data (and/or credits) for DLC. Our strategy is to
322  * send anything we can down to the l2cap layer. When credits run
323  * out, data will naturally bunch up. When not using credit flow
324  * control, we limit the number of packets we have pending to reduce
325  * flow control lag.
326  * We should deal with channel priority somehow.
327  */
328 void
329 rfcomm_dlc_start(struct rfcomm_dlc *dlc)
330 {
331 	struct rfcomm_session *rs = dlc->rd_session;
332 	struct mbuf *m;
333 	int len, credits;
334 
335 	KASSERT(rs != NULL);
336 	KASSERT(rs->rs_state == RFCOMM_SESSION_OPEN);
337 	KASSERT(dlc->rd_state == RFCOMM_DLC_OPEN);
338 
339 	for (;;) {
340 		credits = 0;
341 		len = dlc->rd_mtu;
342 		if (rs->rs_flags & RFCOMM_SESSION_CFC) {
343 			credits = (dlc->rd_rxsize / dlc->rd_mtu);
344 			credits -= dlc->rd_rxcred;
345 			credits = min(credits, RFCOMM_CREDITS_MAX);
346 
347 			if (credits > 0)
348 				len--;
349 
350 			if (dlc->rd_txcred == 0)
351 				len = 0;
352 		} else {
353 			if (rs->rs_flags & RFCOMM_SESSION_RFC)
354 				break;
355 
356 			if (dlc->rd_rmodem & RFCOMM_MSC_FC)
357 				break;
358 
359 			if (dlc->rd_pending > RFCOMM_CREDITS_DEFAULT)
360 				break;
361 		}
362 
363 		if (dlc->rd_txbuf == NULL)
364 			len = 0;
365 
366 		if (len == 0) {
367 			if (credits == 0)
368 				break;
369 
370 			/*
371 			 * No need to send small numbers of credits on their
372 			 * own unless the other end hasn't many left.
373 			 */
374 			if (credits < RFCOMM_CREDITS_DEFAULT
375 			    && dlc->rd_rxcred > RFCOMM_CREDITS_DEFAULT)
376 				break;
377 
378 			m = NULL;
379 		} else {
380 			/*
381 			 * take what data we can from (front of) txbuf
382 			 */
383 			m = dlc->rd_txbuf;
384 			if (len < m->m_pkthdr.len) {
385 				dlc->rd_txbuf = m_split(m, len, M_DONTWAIT);
386 				if (dlc->rd_txbuf == NULL) {
387 					dlc->rd_txbuf = m;
388 					break;
389 				}
390 			} else {
391 				dlc->rd_txbuf = NULL;
392 				len = m->m_pkthdr.len;
393 			}
394 		}
395 
396 		DPRINTFN(10, "dlci %d send %d bytes, %d credits, rxcred = %d\n",
397 			dlc->rd_dlci, len, credits, dlc->rd_rxcred);
398 
399 		if (rfcomm_session_send_uih(rs, dlc, credits, m)) {
400 			printf("%s: lost %d bytes on DLCI %d\n",
401 				__func__, len, dlc->rd_dlci);
402 
403 			break;
404 		}
405 
406 		dlc->rd_pending++;
407 
408 		if (rs->rs_flags & RFCOMM_SESSION_CFC) {
409 			if (len > 0)
410 				dlc->rd_txcred--;
411 
412 			if (credits > 0)
413 				dlc->rd_rxcred += credits;
414 		}
415 	}
416 }
417