sys/netbt/l2cap_lower.c

   1 /*      $NetBSD: l2cap_lower.c,v 1.8 2008/08/05 13:02:10 plunky Exp $   */
   2
   3 /*-
   4  * Copyright (c) 2005 Iain Hibbert.
   5  * Copyright (c) 2006 Itronix Inc.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. The name of Itronix Inc. may not be used to endorse
  17  *    or promote products derived from this software without specific
  18  *    prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY ITRONIX INC. ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL ITRONIX INC. BE LIABLE FOR ANY
  24  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  25  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  26  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  27  * ON ANY THEORY OF LIABILITY, WHETHER IN
  28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  30  * POSSIBILITY OF SUCH DAMAGE.
  31  */
  32
  33 #include <sys/cdefs.h>
  34 __KERNEL_RCSID(0, "$NetBSD: l2cap_lower.c,v 1.8 2008/08/05 13:02:10 plunky Exp $");
  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), &hdr);
 116         m_adj(m, sizeof(hdr));
 117
 118         hdr.length = le16toh(hdr.length);
 119         hdr.dcid = le16toh(hdr.dcid);
 120
 121         DPRINTFN(5, "(%s) received packet (%d bytes)\n",
 122                     device_xname(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_imtu >= hdr.length
 140             && chan->lc_state == L2CAP_OPEN) {
 141                 (*chan->lc_proto->input)(chan->lc_upper, m);
 142                 return;
 143         }
 144
 145         DPRINTF("(%s) invalid L2CAP packet dropped, CID #%d, length %d\n",
 146                 device_xname(link->hl_unit->hci_dev), hdr.dcid, hdr.length);
 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 (MBUFQ_FIRST(&chan->lc_txq) == NULL) {
 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         MBUFQ_DEQUEUE(&chan->lc_txq, m);
 196
 197         KASSERT(chan->lc_link != NULL);
 198         KASSERT(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 }