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
50struct h4_struct {
51 struct sk_buff *rx_skb;
52 struct sk_buff_head txq;
53};
54
55/* Initialize protocol */
56static 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 */
73static 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 */
85static 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) */
104static 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
117static 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 */
124static 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
143static 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
149static 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
160int __init h4_init(void)
161{
162 return hci_uart_register_proto(&h4p);
163}
164
165int __exit h4_deinit(void)
166{
167 return hci_uart_unregister_proto(&h4p);
168}
169
170struct 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}
290EXPORT_SYMBOL_GPL(h4_recv_buf);
291