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), &bt_cb(skb)->pkt_type, 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_ERR("%s: Frame reassembly failed (%d)", hu->hdev->name, err);
136		return err;
137	}
138
139	return count;
140}
141
142static struct sk_buff *h4_dequeue(struct hci_uart *hu)
143{
144	struct h4_struct *h4 = hu->priv;
145	return skb_dequeue(&h4->txq);
146}
147
148static const struct hci_uart_proto h4p = {
149	.id		= HCI_UART_H4,
150	.name		= "H4",
151	.open		= h4_open,
152	.close		= h4_close,
153	.recv		= h4_recv,
154	.enqueue	= h4_enqueue,
155	.dequeue	= h4_dequeue,
156	.flush		= h4_flush,
157};
158
159int __init h4_init(void)
160{
161	return hci_uart_register_proto(&h4p);
162}
163
164int __exit h4_deinit(void)
165{
166	return hci_uart_unregister_proto(&h4p);
167}
168
169struct sk_buff *h4_recv_buf(struct hci_dev *hdev, struct sk_buff *skb,
170			    const unsigned char *buffer, int count,
171			    const struct h4_recv_pkt *pkts, int pkts_count)
172{
173	while (count) {
174		int i, len;
175
176		if (!skb) {
177			for (i = 0; i < pkts_count; i++) {
178				if (buffer[0] != (&pkts[i])->type)
179					continue;
180
181				skb = bt_skb_alloc((&pkts[i])->maxlen,
182						   GFP_ATOMIC);
183				if (!skb)
184					return ERR_PTR(-ENOMEM);
185
186				bt_cb(skb)->pkt_type = (&pkts[i])->type;
187				bt_cb(skb)->expect = (&pkts[i])->hlen;
188				break;
189			}
190
191			/* Check for invalid packet type */
192			if (!skb)
193				return ERR_PTR(-EILSEQ);
194
195			count -= 1;
196			buffer += 1;
197		}
198
199		len = min_t(uint, bt_cb(skb)->expect - skb->len, count);
200		memcpy(skb_put(skb, len), buffer, len);
201
202		count -= len;
203		buffer += len;
204
205		/* Check for partial packet */
206		if (skb->len < bt_cb(skb)->expect)
207			continue;
208
209		for (i = 0; i < pkts_count; i++) {
210			if (bt_cb(skb)->pkt_type == (&pkts[i])->type)
211				break;
212		}
213
214		if (i >= pkts_count) {
215			kfree_skb(skb);
216			return ERR_PTR(-EILSEQ);
217		}
218
219		if (skb->len == (&pkts[i])->hlen) {
220			u16 dlen;
221
222			switch ((&pkts[i])->lsize) {
223			case 0:
224				/* No variable data length */
225				(&pkts[i])->recv(hdev, skb);
226				skb = NULL;
227				break;
228			case 1:
229				/* Single octet variable length */
230				dlen = skb->data[(&pkts[i])->loff];
231				bt_cb(skb)->expect += dlen;
232
233				if (skb_tailroom(skb) < dlen) {
234					kfree_skb(skb);
235					return ERR_PTR(-EMSGSIZE);
236				}
237				break;
238			case 2:
239				/* Double octet variable length */
240				dlen = get_unaligned_le16(skb->data +
241							  (&pkts[i])->loff);
242				bt_cb(skb)->expect += dlen;
243
244				if (skb_tailroom(skb) < dlen) {
245					kfree_skb(skb);
246					return ERR_PTR(-EMSGSIZE);
247				}
248				break;
249			default:
250				/* Unsupported variable length */
251				kfree_skb(skb);
252				return ERR_PTR(-EILSEQ);
253			}
254		} else {
255			/* Complete frame */
256			(&pkts[i])->recv(hdev, skb);
257			skb = NULL;
258		}
259	}
260
261	return skb;
262}
263