xref: /dragonfly/sys/netbt/l2cap_lower.c (revision 03517d4e)
1 /* $DragonFly: src/sys/netbt/l2cap_lower.c,v 1.2 2008/03/18 13:41:42 hasso Exp $ */
2 /* $OpenBSD: src/sys/netbt/l2cap_lower.c,v 1.2 2008/02/24 21:34:48 uwe Exp $ */
3 /* $NetBSD: l2cap_lower.c,v 1.7 2007/11/10 23:12:23 plunky Exp $ */
4 
5 /*-
6  * Copyright (c) 2005 Iain Hibbert.
7  * Copyright (c) 2006 Itronix Inc.
8  * All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. The name of Itronix Inc. may not be used to endorse
19  *    or promote products derived from this software without specific
20  *    prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY ITRONIX INC. ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
24  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
25  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL ITRONIX INC. BE LIABLE FOR ANY
26  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
27  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
29  * ON ANY THEORY OF LIABILITY, WHETHER IN
30  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
31  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
32  * POSSIBILITY OF SUCH DAMAGE.
33  */
34 
35 #include <sys/param.h>
36 #include <sys/kernel.h>
37 #include <sys/malloc.h>
38 #include <sys/mbuf.h>
39 #include <sys/proc.h>
40 #include <sys/queue.h>
41 #include <sys/systm.h>
42 #include <sys/endian.h>
43 
44 #include <netbt/bluetooth.h>
45 #include <netbt/hci.h>
46 #include <netbt/l2cap.h>
47 
48 /****************************************************************************
49  *
50  *	L2CAP Channel Lower Layer interface
51  */
52 
53 /*
54  * L2CAP channel is disconnected, could be:
55  *
56  * HCI layer received "Disconnect Complete" event for ACL link
57  * some Request timed out
58  * Config failed
59  * Other end reported invalid CID
60  * Normal disconnection
61  * Change link mode failed
62  */
63 void
64 l2cap_close(struct l2cap_channel *chan, int err)
65 {
66 	struct l2cap_pdu *pdu;
67 	struct l2cap_req *req, *n;
68 
69 	if (chan->lc_state == L2CAP_CLOSED)
70 		return;
71 
72 	/*
73 	 * Since any potential PDU could be half sent we just let it go,
74 	 * but disassociate ourselves from it as links deal with ownerless
75 	 * PDU's in any case.  We could try harder to flush unsent packets
76 	 * but maybe its better to leave them in the queue?
77 	 */
78 	TAILQ_FOREACH(pdu, &chan->lc_link->hl_txq, lp_next) {
79 		if (pdu->lp_chan == chan)
80 			pdu->lp_chan = NULL;
81 	}
82 
83 	/*
84 	 * and clear any outstanding requests..
85 	 */
86 	req = TAILQ_FIRST(&chan->lc_link->hl_reqs);
87 	while (req != NULL) {
88 		n = TAILQ_NEXT(req, lr_next);
89 		if (req->lr_chan == chan)
90 			l2cap_request_free(req);
91 
92 		req = n;
93 	}
94 
95 	chan->lc_pending = 0;
96 	chan->lc_state = L2CAP_CLOSED;
97 	hci_acl_close(chan->lc_link, err);
98 	chan->lc_link = NULL;
99 
100 	(*chan->lc_proto->disconnected)(chan->lc_upper, err);
101 }
102 
103 /*
104  * Process incoming L2CAP frame from ACL link. We take off the B-Frame
105  * header (which is present in all packets), verify the data length
106  * and distribute the rest of the frame to the relevant channel
107  * handler.
108  */
109 void
110 l2cap_recv_frame(struct mbuf *m, struct hci_link *link)
111 {
112 	struct l2cap_channel *chan;
113 	l2cap_hdr_t hdr;
114 
115 	m_copydata(m, 0, sizeof(hdr), &hdr);
116 	m_adj(m, sizeof(hdr));
117 
118 	hdr.length = letoh16(hdr.length);
119 	hdr.dcid = letoh16(hdr.dcid);
120 
121 	DPRINTFN(5, "(%s) received packet (%d bytes)\n",
122 		    device_get_nameunit(link->hl_unit->hci_dev), hdr.length);
123 
124 	if (hdr.length != m->m_pkthdr.len)
125 		goto failed;
126 
127 	if (hdr.dcid == L2CAP_SIGNAL_CID) {
128 		l2cap_recv_signal(m, link);
129 		return;
130 	}
131 
132 	if (hdr.dcid == L2CAP_CLT_CID) {
133 		m_freem(m);	/* TODO */
134 		return;
135 	}
136 
137 	chan = l2cap_cid_lookup(hdr.dcid);
138 	if (chan != NULL && chan->lc_link == link
139 	    && chan->lc_state == L2CAP_OPEN) {
140 		(*chan->lc_proto->input)(chan->lc_upper, m);
141 		return;
142 	}
143 
144 	DPRINTF("(%s) dropping %d L2CAP data bytes for unknown CID #%d\n",
145 		device_get_nameunit(link->hl_unit->hci_dev), hdr.length,
146 		hdr.dcid);
147 
148 failed:
149 	m_freem(m);
150 }
151 
152 /*
153  * Start another L2CAP packet on its way. This is called from l2cap_send
154  * (when no PDU is pending) and hci_acl_start (when PDU has been placed on
155  * device queue). Thus we can have more than one PDU waiting at the device
156  * if space is available but no single channel will hog the link.
157  */
158 int
159 l2cap_start(struct l2cap_channel *chan)
160 {
161 	struct mbuf *m;
162 	int err = 0;
163 
164 	if (chan->lc_state != L2CAP_OPEN)
165 		return 0;
166 
167 	if (IF_QEMPTY(&chan->lc_txq)) {
168 		DPRINTFN(5, "no data, pending = %d\n", chan->lc_pending);
169 		/*
170 		 * If we are just waiting for the queue to flush
171 		 * and it has, we may disconnect..
172 		 */
173 		if (chan->lc_flags & L2CAP_SHUTDOWN
174 		    && chan->lc_pending == 0) {
175 			chan->lc_state = L2CAP_WAIT_DISCONNECT;
176 			err = l2cap_send_disconnect_req(chan);
177 			if (err)
178 				l2cap_close(chan, err);
179 		}
180 
181 		return err;
182 	}
183 
184 	/*
185 	 * We could check QoS/RFC mode here and optionally not send
186 	 * the packet if we are not ready for any reason
187 	 *
188 	 * Also to support flush timeout then we might want to start
189 	 * the timer going? (would need to keep some kind of record
190 	 * of packets sent, possibly change it so that we allocate
191 	 * the l2cap_pdu and fragment the packet, then hand it down
192 	 * and get it back when its completed). Hm.
193 	 */
194 
195 	IF_DEQUEUE(&chan->lc_txq, m);
196 
197 	KKASSERT(chan->lc_link != NULL);
198 	KKASSERT(m != NULL);
199 
200 	DPRINTFN(5, "CID #%d sending packet (%d bytes)\n",
201 		chan->lc_lcid, m->m_pkthdr.len);
202 
203 	chan->lc_pending++;
204 	return hci_acl_send(m, chan->lc_link, chan);
205 }
206