1 /* $OpenBSD: l2cap_lower.c,v 1.1 2007/05/30 03:42:53 uwe Exp $ */
2 /* $NetBSD: l2cap_lower.c,v 1.6 2007/04/21 06:15:23 plunky Exp $ */
3
4 /*-
5 * Copyright (c) 2005 Iain Hibbert.
6 * Copyright (c) 2006 Itronix Inc.
7 * All rights reserved.
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
36 #include <sys/param.h>
37 #include <sys/kernel.h>
38 #include <sys/malloc.h>
39 #include <sys/mbuf.h>
40 #include <sys/proc.h>
41 #include <sys/queue.h>
42 #include <sys/systm.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), (caddr_t)&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 link->hl_unit->hci_devname, 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 link->hl_unit->hci_devname, hdr.length, hdr.dcid);
146
147 failed:
148 m_freem(m);
149 }
150
151 /*
152 * Start another L2CAP packet on its way. This is called from l2cap_send
153 * (when no PDU is pending) and hci_acl_start (when PDU has been placed on
154 * device queue). Thus we can have more than one PDU waiting at the device
155 * if space is available but no single channel will hog the link.
156 */
157 int
158 l2cap_start(struct l2cap_channel *chan)
159 {
160 struct mbuf *m;
161 int err = 0;
162
163 if (chan->lc_state != L2CAP_OPEN)
164 return 0;
165
166 if (IF_IS_EMPTY(&chan->lc_txq)) {
167 DPRINTFN(5, "no data, pending = %d\n", chan->lc_pending);
168 /*
169 * If we are just waiting for the queue to flush
170 * and it has, we may disconnect..
171 */
172 if (chan->lc_flags & L2CAP_SHUTDOWN
173 && chan->lc_pending == 0) {
174 chan->lc_state = L2CAP_WAIT_DISCONNECT;
175 err = l2cap_send_disconnect_req(chan);
176 if (err)
177 l2cap_close(chan, err);
178 }
179
180 return err;
181 }
182
183 /*
184 * We could check QoS/RFC mode here and optionally not send
185 * the packet if we are not ready for any reason
186 *
187 * Also to support flush timeout then we might want to start
188 * the timer going? (would need to keep some kind of record
189 * of packets sent, possibly change it so that we allocate
190 * the l2cap_pdu and fragment the packet, then hand it down
191 * and get it back when its completed). Hm.
192 */
193
194 IF_DEQUEUE(&chan->lc_txq, m);
195
196 KASSERT(chan->lc_link != NULL);
197 KASSERT(m != NULL);
198
199 DPRINTFN(5, "CID #%d sending packet (%d bytes)\n",
200 chan->lc_lcid, m->m_pkthdr.len);
201
202 chan->lc_pending++;
203 return hci_acl_send(m, chan->lc_link, chan);
204 }