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 while (count) { 178 int i, len; 179 180 /* remove padding bytes from buffer */ 181 for (; hu->padding && count > 0; hu->padding--) { 182 count--; 183 buffer++; 184 } 185 if (!count) 186 break; 187 188 if (!skb) { 189 for (i = 0; i < pkts_count; i++) { 190 if (buffer[0] != (&pkts[i])->type) 191 continue; 192 193 skb = bt_skb_alloc((&pkts[i])->maxlen, 194 GFP_ATOMIC); 195 if (!skb) 196 return ERR_PTR(-ENOMEM); 197 198 hci_skb_pkt_type(skb) = (&pkts[i])->type; 199 hci_skb_expect(skb) = (&pkts[i])->hlen; 200 break; 201 } 202 203 /* Check for invalid packet type */ 204 if (!skb) 205 return ERR_PTR(-EILSEQ); 206 207 count -= 1; 208 buffer += 1; 209 } 210 211 len = min_t(uint, hci_skb_expect(skb) - skb->len, count); 212 skb_put_data(skb, buffer, len); 213 214 count -= len; 215 buffer += len; 216 217 /* Check for partial packet */ 218 if (skb->len < hci_skb_expect(skb)) 219 continue; 220 221 for (i = 0; i < pkts_count; i++) { 222 if (hci_skb_pkt_type(skb) == (&pkts[i])->type) 223 break; 224 } 225 226 if (i >= pkts_count) { 227 kfree_skb(skb); 228 return ERR_PTR(-EILSEQ); 229 } 230 231 if (skb->len == (&pkts[i])->hlen) { 232 u16 dlen; 233 234 switch ((&pkts[i])->lsize) { 235 case 0: 236 /* No variable data length */ 237 dlen = 0; 238 break; 239 case 1: 240 /* Single octet variable length */ 241 dlen = skb->data[(&pkts[i])->loff]; 242 hci_skb_expect(skb) += dlen; 243 244 if (skb_tailroom(skb) < dlen) { 245 kfree_skb(skb); 246 return ERR_PTR(-EMSGSIZE); 247 } 248 break; 249 case 2: 250 /* Double octet variable length */ 251 dlen = get_unaligned_le16(skb->data + 252 (&pkts[i])->loff); 253 hci_skb_expect(skb) += dlen; 254 255 if (skb_tailroom(skb) < dlen) { 256 kfree_skb(skb); 257 return ERR_PTR(-EMSGSIZE); 258 } 259 break; 260 default: 261 /* Unsupported variable length */ 262 kfree_skb(skb); 263 return ERR_PTR(-EILSEQ); 264 } 265 266 if (!dlen) { 267 hu->padding = (skb->len - 1) % alignment; 268 hu->padding = (alignment - hu->padding) % alignment; 269 270 /* No more data, complete frame */ 271 (&pkts[i])->recv(hdev, skb); 272 skb = NULL; 273 } 274 } else { 275 hu->padding = (skb->len - 1) % alignment; 276 hu->padding = (alignment - hu->padding) % alignment; 277 278 /* Complete frame */ 279 (&pkts[i])->recv(hdev, skb); 280 skb = NULL; 281 } 282 } 283 284 return skb; 285 } 286 EXPORT_SYMBOL_GPL(h4_recv_buf); 287