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 #include <asm/unaligned.h>
  44
  45 #include <net/bluetooth/bluetooth.h>
  46 #include <net/bluetooth/hci_core.h>
  47
  48 #include "hci_uart.h"
  49
  50 struct h4_struct {
  51         struct sk_buff *rx_skb;
  52         struct sk_buff_head txq;
  53 };
  54
  55 /* Initialize protocol */
  56 static int h4_open(struct hci_uart *hu)
  57 {
  58         struct h4_struct *h4;
  59
  60         BT_DBG("hu %p", hu);
  61
  62         h4 = kzalloc(sizeof(*h4), GFP_KERNEL);
  63         if (!h4)
  64                 return -ENOMEM;
  65
  66         skb_queue_head_init(&h4->txq);
  67
  68         hu->priv = h4;
  69         return 0;
  70 }
  71
  72 /* Flush protocol data */
  73 static int h4_flush(struct hci_uart *hu)
  74 {
  75         struct h4_struct *h4 = hu->priv;
  76
  77         BT_DBG("hu %p", hu);
  78
  79         skb_queue_purge(&h4->txq);
  80
  81         return 0;
  82 }
  83
  84 /* Close protocol */
  85 static int h4_close(struct hci_uart *hu)
  86 {
  87         struct h4_struct *h4 = hu->priv;
  88
  89         hu->priv = NULL;
  90
  91         BT_DBG("hu %p", hu);
  92
  93         skb_queue_purge(&h4->txq);
  94
  95         kfree_skb(h4->rx_skb);
  96
  97         hu->priv = NULL;
  98         kfree(h4);
  99
 100         return 0;
 101 }
 102
 103 /* Enqueue frame for transmittion (padding, crc, etc) */
 104 static int h4_enqueue(struct hci_uart *hu, struct sk_buff *skb)
 105 {
 106         struct h4_struct *h4 = hu->priv;
 107
 108         BT_DBG("hu %p skb %p", hu, skb);
 109
 110         /* Prepend skb with frame type */
 111         memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
 112         skb_queue_tail(&h4->txq, skb);
 113
 114         return 0;
 115 }
 116
 117 static const struct h4_recv_pkt h4_recv_pkts[] = {
 118         { H4_RECV_ACL,   .recv = hci_recv_frame },
 119         { H4_RECV_SCO,   .recv = hci_recv_frame },
 120         { H4_RECV_EVENT, .recv = hci_recv_frame },
 121 };
 122
 123 /* Recv data */
 124 static int h4_recv(struct hci_uart *hu, const void *data, int count)
 125 {
 126         struct h4_struct *h4 = hu->priv;
 127
 128         if (!test_bit(HCI_UART_REGISTERED, &hu->flags))
 129                 return -EUNATCH;
 130
 131         h4->rx_skb = h4_recv_buf(hu->hdev, h4->rx_skb, data, count,
 132                                  h4_recv_pkts, ARRAY_SIZE(h4_recv_pkts));
 133         if (IS_ERR(h4->rx_skb)) {
 134                 int err = PTR_ERR(h4->rx_skb);
 135                 bt_dev_err(hu->hdev, "Frame reassembly failed (%d)", err);
 136                 h4->rx_skb = NULL;
 137                 return err;
 138         }
 139
 140         return count;
 141 }
 142
 143 static struct sk_buff *h4_dequeue(struct hci_uart *hu)
 144 {
 145         struct h4_struct *h4 = hu->priv;
 146         return skb_dequeue(&h4->txq);
 147 }
 148
 149 static const struct hci_uart_proto h4p = {
 150         .id             = HCI_UART_H4,
 151         .name           = "H4",
 152         .open           = h4_open,
 153         .close          = h4_close,
 154         .recv           = h4_recv,
 155         .enqueue        = h4_enqueue,
 156         .dequeue        = h4_dequeue,
 157         .flush          = h4_flush,
 158 };
 159
 160 int __init h4_init(void)
 161 {
 162         return hci_uart_register_proto(&h4p);
 163 }
 164
 165 int __exit h4_deinit(void)
 166 {
 167         return hci_uart_unregister_proto(&h4p);
 168 }
 169
 170 struct sk_buff *h4_recv_buf(struct hci_dev *hdev, struct sk_buff *skb,
 171                             const unsigned char *buffer, int count,
 172                             const struct h4_recv_pkt *pkts, int pkts_count)
 173 {
 174         struct hci_uart *hu = hci_get_drvdata(hdev);
 175         u8 alignment = hu->alignment ? hu->alignment : 1;
 176
 177         /* Check for error from previous call */
 178         if (IS_ERR(skb))
 179                 skb = NULL;
 180
 181         while (count) {
 182                 int i, len;
 183
 184                 /* remove padding bytes from buffer */
 185                 for (; hu->padding && count > 0; hu->padding--) {
 186                         count--;
 187                         buffer++;
 188                 }
 189                 if (!count)
 190                         break;
 191
 192                 if (!skb) {
 193                         for (i = 0; i < pkts_count; i++) {
 194                                 if (buffer[0] != (&pkts[i])->type)
 195                                         continue;
 196
 197                                 skb = bt_skb_alloc((&pkts[i])->maxlen,
 198                                                    GFP_ATOMIC);
 199                                 if (!skb)
 200                                         return ERR_PTR(-ENOMEM);
 201
 202                                 hci_skb_pkt_type(skb) = (&pkts[i])->type;
 203                                 hci_skb_expect(skb) = (&pkts[i])->hlen;
 204                                 break;
 205                         }
 206
 207                         /* Check for invalid packet type */
 208                         if (!skb)
 209                                 return ERR_PTR(-EILSEQ);
 210
 211                         count -= 1;
 212                         buffer += 1;
 213                 }
 214
 215                 len = min_t(uint, hci_skb_expect(skb) - skb->len, count);
 216                 skb_put_data(skb, buffer, len);
 217
 218                 count -= len;
 219                 buffer += len;
 220
 221                 /* Check for partial packet */
 222                 if (skb->len < hci_skb_expect(skb))
 223                         continue;
 224
 225                 for (i = 0; i < pkts_count; i++) {
 226                         if (hci_skb_pkt_type(skb) == (&pkts[i])->type)
 227                                 break;
 228                 }
 229
 230                 if (i >= pkts_count) {
 231                         kfree_skb(skb);
 232                         return ERR_PTR(-EILSEQ);
 233                 }
 234
 235                 if (skb->len == (&pkts[i])->hlen) {
 236                         u16 dlen;
 237
 238                         switch ((&pkts[i])->lsize) {
 239                         case 0:
 240                                 /* No variable data length */
 241                                 dlen = 0;
 242                                 break;
 243                         case 1:
 244                                 /* Single octet variable length */
 245                                 dlen = skb->data[(&pkts[i])->loff];
 246                                 hci_skb_expect(skb) += dlen;
 247
 248                                 if (skb_tailroom(skb) < dlen) {
 249                                         kfree_skb(skb);
 250                                         return ERR_PTR(-EMSGSIZE);
 251                                 }
 252                                 break;
 253                         case 2:
 254                                 /* Double octet variable length */
 255                                 dlen = get_unaligned_le16(skb->data +
 256                                                           (&pkts[i])->loff);
 257                                 hci_skb_expect(skb) += dlen;
 258
 259                                 if (skb_tailroom(skb) < dlen) {
 260                                         kfree_skb(skb);
 261                                         return ERR_PTR(-EMSGSIZE);
 262                                 }
 263                                 break;
 264                         default:
 265                                 /* Unsupported variable length */
 266                                 kfree_skb(skb);
 267                                 return ERR_PTR(-EILSEQ);
 268                         }
 269
 270                         if (!dlen) {
 271                                 hu->padding = (skb->len - 1) % alignment;
 272                                 hu->padding = (alignment - hu->padding) % alignment;
 273
 274                                 /* No more data, complete frame */
 275                                 (&pkts[i])->recv(hdev, skb);
 276                                 skb = NULL;
 277                         }
 278                 } else {
 279                         hu->padding = (skb->len - 1) % alignment;
 280                         hu->padding = (alignment - hu->padding) % alignment;
 281
 282                         /* Complete frame */
 283                         (&pkts[i])->recv(hdev, skb);
 284                         skb = NULL;
 285                 }
 286         }
 287
 288         return skb;
 289 }
 290 EXPORT_SYMBOL_GPL(h4_recv_buf);