drivers/bluetooth/hci_h4.c

   1 /*
   2  *
   3  *  Bluetooth HCI UART driver
   4  *
   5  *  Copyright (C) 2000-2001  Qualcomm Incorporated
   6  *  Copyright (C) 2002-2003  Maxim Krasnyansky <maxk@qualcomm.com>
   7  *  Copyright (C) 2004-2005  Marcel Holtmann <marcel@holtmann.org>
   8  *
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License as published by
  12  *  the Free Software Foundation; either version 2 of the License, or
  13  *  (at your option) any later version.
  14  *
  15  *  This program is distributed in the hope that it will be useful,
  16  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  *  GNU General Public License for more details.
  19  *
  20  *  You should have received a copy of the GNU General Public License
  21  *  along with this program; if not, write to the Free Software
  22  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  23  *
  24  */
  25
  26 #include <linux/module.h>
  27
  28 #include <linux/kernel.h>
  29 #include <linux/init.h>
  30 #include <linux/types.h>
  31 #include <linux/fcntl.h>
  32 #include <linux/interrupt.h>
  33 #include <linux/ptrace.h>
  34 #include <linux/poll.h>
  35
  36 #include <linux/slab.h>
  37 #include <linux/tty.h>
  38 #include <linux/errno.h>
  39 #include <linux/string.h>
  40 #include <linux/signal.h>
  41 #include <linux/ioctl.h>
  42 #include <linux/skbuff.h>
  43
  44 #include <net/bluetooth/bluetooth.h>
  45 #include <net/bluetooth/hci_core.h>
  46
  47 #include "hci_uart.h"
  48
  49 struct h4_struct {
  50         struct sk_buff *rx_skb;
  51         struct sk_buff_head txq;
  52 };
  53
  54 /* Initialize protocol */
  55 static int h4_open(struct hci_uart *hu)
  56 {
  57         struct h4_struct *h4;
  58
  59         BT_DBG("hu %p", hu);
  60
  61         h4 = kzalloc(sizeof(*h4), GFP_KERNEL);
  62         if (!h4)
  63                 return -ENOMEM;
  64
  65         skb_queue_head_init(&h4->txq);
  66
  67         hu->priv = h4;
  68         return 0;
  69 }
  70
  71 /* Flush protocol data */
  72 static int h4_flush(struct hci_uart *hu)
  73 {
  74         struct h4_struct *h4 = hu->priv;
  75
  76         BT_DBG("hu %p", hu);
  77
  78         skb_queue_purge(&h4->txq);
  79
  80         return 0;
  81 }
  82
  83 /* Close protocol */
  84 static int h4_close(struct hci_uart *hu)
  85 {
  86         struct h4_struct *h4 = hu->priv;
  87
  88         hu->priv = NULL;
  89
  90         BT_DBG("hu %p", hu);
  91
  92         skb_queue_purge(&h4->txq);
  93
  94         kfree_skb(h4->rx_skb);
  95
  96         hu->priv = NULL;
  97         kfree(h4);
  98
  99         return 0;
 100 }
 101
 102 /* Enqueue frame for transmittion (padding, crc, etc) */
 103 static int h4_enqueue(struct hci_uart *hu, struct sk_buff *skb)
 104 {
 105         struct h4_struct *h4 = hu->priv;
 106
 107         BT_DBG("hu %p skb %p", hu, skb);
 108
 109         /* Prepend skb with frame type */
 110         memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
 111         skb_queue_tail(&h4->txq, skb);
 112
 113         return 0;
 114 }
 115
 116 /* Recv data */
 117 static int h4_recv(struct hci_uart *hu, const void *data, int count)
 118 {
 119         struct h4_struct *h4 = hu->priv;
 120
 121         if (!test_bit(HCI_UART_REGISTERED, &hu->flags))
 122                 return -EUNATCH;
 123
 124         h4->rx_skb = h4_recv_buf(hu->hdev, h4->rx_skb, data, count);
 125         if (IS_ERR(h4->rx_skb)) {
 126                 int err = PTR_ERR(h4->rx_skb);
 127                 BT_ERR("%s: Frame reassembly failed (%d)", hu->hdev->name, err);
 128                 return err;
 129         }
 130
 131         return count;
 132 }
 133
 134 static struct sk_buff *h4_dequeue(struct hci_uart *hu)
 135 {
 136         struct h4_struct *h4 = hu->priv;
 137         return skb_dequeue(&h4->txq);
 138 }
 139
 140 static const struct hci_uart_proto h4p = {
 141         .id             = HCI_UART_H4,
 142         .name           = "H4",
 143         .open           = h4_open,
 144         .close          = h4_close,
 145         .recv           = h4_recv,
 146         .enqueue        = h4_enqueue,
 147         .dequeue        = h4_dequeue,
 148         .flush          = h4_flush,
 149 };
 150
 151 int __init h4_init(void)
 152 {
 153         return hci_uart_register_proto(&h4p);
 154 }
 155
 156 int __exit h4_deinit(void)
 157 {
 158         return hci_uart_unregister_proto(&h4p);
 159 }
 160
 161 struct sk_buff *h4_recv_buf(struct hci_dev *hdev, struct sk_buff *skb,
 162                             const unsigned char *buffer, int count)
 163 {
 164         while (count) {
 165                 int len;
 166
 167                 if (!skb) {
 168                         switch (buffer[0]) {
 169                         case HCI_ACLDATA_PKT:
 170                                 skb = bt_skb_alloc(HCI_MAX_FRAME_SIZE,
 171                                                    GFP_ATOMIC);
 172                                 if (!skb)
 173                                         return ERR_PTR(-ENOMEM);
 174
 175                                 bt_cb(skb)->pkt_type = HCI_ACLDATA_PKT;
 176                                 bt_cb(skb)->expect = HCI_ACL_HDR_SIZE;
 177                                 break;
 178                         case HCI_SCODATA_PKT:
 179                                 skb = bt_skb_alloc(HCI_MAX_SCO_SIZE,
 180                                                    GFP_ATOMIC);
 181                                 if (!skb)
 182                                         return ERR_PTR(-ENOMEM);
 183
 184                                 bt_cb(skb)->pkt_type = HCI_SCODATA_PKT;
 185                                 bt_cb(skb)->expect = HCI_SCO_HDR_SIZE;
 186                                 break;
 187                         case HCI_EVENT_PKT:
 188                                 skb = bt_skb_alloc(HCI_MAX_EVENT_SIZE,
 189                                                    GFP_ATOMIC);
 190                                 if (!skb)
 191                                         return ERR_PTR(-ENOMEM);
 192
 193                                 bt_cb(skb)->pkt_type = HCI_EVENT_PKT;
 194                                 bt_cb(skb)->expect = HCI_EVENT_HDR_SIZE;
 195                                 break;
 196                         default:
 197                                 return ERR_PTR(-EILSEQ);
 198                         }
 199
 200                         count -= 1;
 201                         buffer += 1;
 202                 }
 203
 204                 len = min_t(uint, bt_cb(skb)->expect, count);
 205                 memcpy(skb_put(skb, len), buffer, len);
 206
 207                 count -= len;
 208                 buffer += len;
 209                 bt_cb(skb)->expect -= len;
 210
 211                 switch (bt_cb(skb)->pkt_type) {
 212                 case HCI_ACLDATA_PKT:
 213                         if (skb->len == HCI_ACL_HDR_SIZE) {
 214                                 __le16 dlen = hci_acl_hdr(skb)->dlen;
 215
 216                                 /* Complete ACL header */
 217                                 bt_cb(skb)->expect = __le16_to_cpu(dlen);
 218
 219                                 if (skb_tailroom(skb) < bt_cb(skb)->expect) {
 220                                         kfree_skb(skb);
 221                                         return ERR_PTR(-EMSGSIZE);
 222                                 }
 223                         }
 224                         break;
 225                 case HCI_SCODATA_PKT:
 226                         if (skb->len == HCI_SCO_HDR_SIZE) {
 227                                 /* Complete SCO header */
 228                                 bt_cb(skb)->expect = hci_sco_hdr(skb)->dlen;
 229
 230                                 if (skb_tailroom(skb) < bt_cb(skb)->expect) {
 231                                         kfree_skb(skb);
 232                                         return ERR_PTR(-EMSGSIZE);
 233                                 }
 234                         }
 235                         break;
 236                 case HCI_EVENT_PKT:
 237                         if (skb->len == HCI_EVENT_HDR_SIZE) {
 238                                 /* Complete event header */
 239                                 bt_cb(skb)->expect = hci_event_hdr(skb)->plen;
 240
 241                                 if (skb_tailroom(skb) < bt_cb(skb)->expect) {
 242                                         kfree_skb(skb);
 243                                         return ERR_PTR(-EMSGSIZE);
 244                                 }
 245                         }
 246                         break;
 247                 }
 248
 249                 if (bt_cb(skb)->expect == 0) {
 250                         /* Complete frame */
 251                         hci_recv_frame(hdev, skb);
 252                         skb = NULL;
 253                 }
 254         }
 255
 256         return skb;
 257 }