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 #define VERSION "1.2"
  50
  51 struct h4_struct {
  52         unsigned long rx_state;
  53         unsigned long rx_count;
  54         struct sk_buff *rx_skb;
  55         struct sk_buff_head txq;
  56 };
  57
  58 /* H4 receiver States */
  59 #define H4_W4_PACKET_TYPE       0
  60 #define H4_W4_EVENT_HDR         1
  61 #define H4_W4_ACL_HDR           2
  62 #define H4_W4_SCO_HDR           3
  63 #define H4_W4_DATA              4
  64
  65 /* Initialize protocol */
  66 static int h4_open(struct hci_uart *hu)
  67 {
  68         struct h4_struct *h4;
  69
  70         BT_DBG("hu %p", hu);
  71
  72         h4 = kzalloc(sizeof(*h4), GFP_ATOMIC);
  73         if (!h4)
  74                 return -ENOMEM;
  75
  76         skb_queue_head_init(&h4->txq);
  77
  78         hu->priv = h4;
  79         return 0;
  80 }
  81
  82 /* Flush protocol data */
  83 static int h4_flush(struct hci_uart *hu)
  84 {
  85         struct h4_struct *h4 = hu->priv;
  86
  87         BT_DBG("hu %p", hu);
  88
  89         skb_queue_purge(&h4->txq);
  90
  91         return 0;
  92 }
  93
  94 /* Close protocol */
  95 static int h4_close(struct hci_uart *hu)
  96 {
  97         struct h4_struct *h4 = hu->priv;
  98
  99         hu->priv = NULL;
 100
 101         BT_DBG("hu %p", hu);
 102
 103         skb_queue_purge(&h4->txq);
 104
 105         if (h4->rx_skb)
 106                 kfree_skb(h4->rx_skb);
 107
 108         hu->priv = NULL;
 109         kfree(h4);
 110
 111         return 0;
 112 }
 113
 114 /* Enqueue frame for transmittion (padding, crc, etc) */
 115 static int h4_enqueue(struct hci_uart *hu, struct sk_buff *skb)
 116 {
 117         struct h4_struct *h4 = hu->priv;
 118
 119         BT_DBG("hu %p skb %p", hu, skb);
 120
 121         /* Prepend skb with frame type */
 122         memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
 123         skb_queue_tail(&h4->txq, skb);
 124
 125         return 0;
 126 }
 127
 128 static inline int h4_check_data_len(struct h4_struct *h4, int len)
 129 {
 130         register int room = skb_tailroom(h4->rx_skb);
 131
 132         BT_DBG("len %d room %d", len, room);
 133
 134         if (!len) {
 135                 hci_recv_frame(h4->rx_skb);
 136         } else if (len > room) {
 137                 BT_ERR("Data length is too large");
 138                 kfree_skb(h4->rx_skb);
 139         } else {
 140                 h4->rx_state = H4_W4_DATA;
 141                 h4->rx_count = len;
 142                 return len;
 143         }
 144
 145         h4->rx_state = H4_W4_PACKET_TYPE;
 146         h4->rx_skb   = NULL;
 147         h4->rx_count = 0;
 148
 149         return 0;
 150 }
 151
 152 /* Recv data */
 153 static int h4_recv(struct hci_uart *hu, void *data, int count)
 154 {
 155         struct h4_struct *h4 = hu->priv;
 156         register char *ptr;
 157         struct hci_event_hdr *eh;
 158         struct hci_acl_hdr   *ah;
 159         struct hci_sco_hdr   *sh;
 160         register int len, type, dlen;
 161
 162         BT_DBG("hu %p count %d rx_state %ld rx_count %ld",
 163                         hu, count, h4->rx_state, h4->rx_count);
 164
 165         ptr = data;
 166         while (count) {
 167                 if (h4->rx_count) {
 168                         len = min_t(unsigned int, h4->rx_count, count);
 169                         memcpy(skb_put(h4->rx_skb, len), ptr, len);
 170                         h4->rx_count -= len; count -= len; ptr += len;
 171
 172                         if (h4->rx_count)
 173                                 continue;
 174
 175                         switch (h4->rx_state) {
 176                         case H4_W4_DATA:
 177                                 BT_DBG("Complete data");
 178
 179                                 hci_recv_frame(h4->rx_skb);
 180
 181                                 h4->rx_state = H4_W4_PACKET_TYPE;
 182                                 h4->rx_skb = NULL;
 183                                 continue;
 184
 185                         case H4_W4_EVENT_HDR:
 186                                 eh = hci_event_hdr(h4->rx_skb);
 187
 188                                 BT_DBG("Event header: evt 0x%2.2x plen %d", eh->evt, eh->plen);
 189
 190                                 h4_check_data_len(h4, eh->plen);
 191                                 continue;
 192
 193                         case H4_W4_ACL_HDR:
 194                                 ah = hci_acl_hdr(h4->rx_skb);
 195                                 dlen = __le16_to_cpu(ah->dlen);
 196
 197                                 BT_DBG("ACL header: dlen %d", dlen);
 198
 199                                 h4_check_data_len(h4, dlen);
 200                                 continue;
 201
 202                         case H4_W4_SCO_HDR:
 203                                 sh = hci_sco_hdr(h4->rx_skb);
 204
 205                                 BT_DBG("SCO header: dlen %d", sh->dlen);
 206
 207                                 h4_check_data_len(h4, sh->dlen);
 208                                 continue;
 209                         }
 210                 }
 211
 212                 /* H4_W4_PACKET_TYPE */
 213                 switch (*ptr) {
 214                 case HCI_EVENT_PKT:
 215                         BT_DBG("Event packet");
 216                         h4->rx_state = H4_W4_EVENT_HDR;
 217                         h4->rx_count = HCI_EVENT_HDR_SIZE;
 218                         type = HCI_EVENT_PKT;
 219                         break;
 220
 221                 case HCI_ACLDATA_PKT:
 222                         BT_DBG("ACL packet");
 223                         h4->rx_state = H4_W4_ACL_HDR;
 224                         h4->rx_count = HCI_ACL_HDR_SIZE;
 225                         type = HCI_ACLDATA_PKT;
 226                         break;
 227
 228                 case HCI_SCODATA_PKT:
 229                         BT_DBG("SCO packet");
 230                         h4->rx_state = H4_W4_SCO_HDR;
 231                         h4->rx_count = HCI_SCO_HDR_SIZE;
 232                         type = HCI_SCODATA_PKT;
 233                         break;
 234
 235                 default:
 236                         BT_ERR("Unknown HCI packet type %2.2x", (__u8)*ptr);
 237                         hu->hdev->stat.err_rx++;
 238                         ptr++; count--;
 239                         continue;
 240                 };
 241
 242                 ptr++; count--;
 243
 244                 /* Allocate packet */
 245                 h4->rx_skb = bt_skb_alloc(HCI_MAX_FRAME_SIZE, GFP_ATOMIC);
 246                 if (!h4->rx_skb) {
 247                         BT_ERR("Can't allocate mem for new packet");
 248                         h4->rx_state = H4_W4_PACKET_TYPE;
 249                         h4->rx_count = 0;
 250                         return 0;
 251                 }
 252
 253                 h4->rx_skb->dev = (void *) hu->hdev;
 254                 bt_cb(h4->rx_skb)->pkt_type = type;
 255         }
 256
 257         return count;
 258 }
 259
 260 static struct sk_buff *h4_dequeue(struct hci_uart *hu)
 261 {
 262         struct h4_struct *h4 = hu->priv;
 263         return skb_dequeue(&h4->txq);
 264 }
 265
 266 static struct hci_uart_proto h4p = {
 267         .id             = HCI_UART_H4,
 268         .open           = h4_open,
 269         .close          = h4_close,
 270         .recv           = h4_recv,
 271         .enqueue        = h4_enqueue,
 272         .dequeue        = h4_dequeue,
 273         .flush          = h4_flush,
 274 };
 275
 276 int h4_init(void)
 277 {
 278         int err = hci_uart_register_proto(&h4p);
 279
 280         if (!err)
 281                 BT_INFO("HCI H4 protocol initialized");
 282         else
 283                 BT_ERR("HCI H4 protocol registration failed");
 284
 285         return err;
 286 }
 287
 288 int h4_deinit(void)
 289 {
 290         return hci_uart_unregister_proto(&h4p);
 291 }