1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 *
4 * Bluetooth HCI UART driver
5 *
6 * Copyright (C) 2000-2001 Qualcomm Incorporated
7 * Copyright (C) 2002-2003 Maxim Krasnyansky <maxk@qualcomm.com>
8 * Copyright (C) 2004-2005 Marcel Holtmann <marcel@holtmann.org>
9 */
10
11 #include <linux/module.h>
12
13 #include <linux/kernel.h>
14 #include <linux/init.h>
15 #include <linux/types.h>
16 #include <linux/fcntl.h>
17 #include <linux/interrupt.h>
18 #include <linux/ptrace.h>
19 #include <linux/poll.h>
20
21 #include <linux/slab.h>
22 #include <linux/tty.h>
23 #include <linux/errno.h>
24 #include <linux/string.h>
25 #include <linux/signal.h>
26 #include <linux/ioctl.h>
27 #include <linux/skbuff.h>
28 #include <asm/unaligned.h>
29
30 #include <net/bluetooth/bluetooth.h>
31 #include <net/bluetooth/hci_core.h>
32
33 #include "hci_uart.h"
34
35 struct h4_struct {
36 struct sk_buff *rx_skb;
37 struct sk_buff_head txq;
38 };
39
40 /* Initialize protocol */
h4_open(struct hci_uart * hu)41 static int h4_open(struct hci_uart *hu)
42 {
43 struct h4_struct *h4;
44
45 BT_DBG("hu %p", hu);
46
47 h4 = kzalloc(sizeof(*h4), GFP_KERNEL);
48 if (!h4)
49 return -ENOMEM;
50
51 skb_queue_head_init(&h4->txq);
52
53 hu->priv = h4;
54 return 0;
55 }
56
57 /* Flush protocol data */
h4_flush(struct hci_uart * hu)58 static int h4_flush(struct hci_uart *hu)
59 {
60 struct h4_struct *h4 = hu->priv;
61
62 BT_DBG("hu %p", hu);
63
64 skb_queue_purge(&h4->txq);
65
66 return 0;
67 }
68
69 /* Close protocol */
h4_close(struct hci_uart * hu)70 static int h4_close(struct hci_uart *hu)
71 {
72 struct h4_struct *h4 = hu->priv;
73
74 BT_DBG("hu %p", hu);
75
76 skb_queue_purge(&h4->txq);
77
78 kfree_skb(h4->rx_skb);
79
80 hu->priv = NULL;
81 kfree(h4);
82
83 return 0;
84 }
85
86 /* Enqueue frame for transmission (padding, crc, etc) */
h4_enqueue(struct hci_uart * hu,struct sk_buff * skb)87 static int h4_enqueue(struct hci_uart *hu, struct sk_buff *skb)
88 {
89 struct h4_struct *h4 = hu->priv;
90
91 BT_DBG("hu %p skb %p", hu, skb);
92
93 /* Prepend skb with frame type */
94 memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
95 skb_queue_tail(&h4->txq, skb);
96
97 return 0;
98 }
99
100 static const struct h4_recv_pkt h4_recv_pkts[] = {
101 { H4_RECV_ACL, .recv = hci_recv_frame },
102 { H4_RECV_SCO, .recv = hci_recv_frame },
103 { H4_RECV_EVENT, .recv = hci_recv_frame },
104 { H4_RECV_ISO, .recv = hci_recv_frame },
105 };
106
107 /* Recv data */
h4_recv(struct hci_uart * hu,const void * data,int count)108 static int h4_recv(struct hci_uart *hu, const void *data, int count)
109 {
110 struct h4_struct *h4 = hu->priv;
111
112 if (!test_bit(HCI_UART_REGISTERED, &hu->flags))
113 return -EUNATCH;
114
115 h4->rx_skb = h4_recv_buf(hu->hdev, h4->rx_skb, data, count,
116 h4_recv_pkts, ARRAY_SIZE(h4_recv_pkts));
117 if (IS_ERR(h4->rx_skb)) {
118 int err = PTR_ERR(h4->rx_skb);
119 bt_dev_err(hu->hdev, "Frame reassembly failed (%d)", err);
120 h4->rx_skb = NULL;
121 return err;
122 }
123
124 return count;
125 }
126
h4_dequeue(struct hci_uart * hu)127 static struct sk_buff *h4_dequeue(struct hci_uart *hu)
128 {
129 struct h4_struct *h4 = hu->priv;
130 return skb_dequeue(&h4->txq);
131 }
132
133 static const struct hci_uart_proto h4p = {
134 .id = HCI_UART_H4,
135 .name = "H4",
136 .open = h4_open,
137 .close = h4_close,
138 .recv = h4_recv,
139 .enqueue = h4_enqueue,
140 .dequeue = h4_dequeue,
141 .flush = h4_flush,
142 };
143
h4_init(void)144 int __init h4_init(void)
145 {
146 return hci_uart_register_proto(&h4p);
147 }
148
h4_deinit(void)149 int __exit h4_deinit(void)
150 {
151 return hci_uart_unregister_proto(&h4p);
152 }
153
h4_recv_buf(struct hci_dev * hdev,struct sk_buff * skb,const unsigned char * buffer,int count,const struct h4_recv_pkt * pkts,int pkts_count)154 struct sk_buff *h4_recv_buf(struct hci_dev *hdev, struct sk_buff *skb,
155 const unsigned char *buffer, int count,
156 const struct h4_recv_pkt *pkts, int pkts_count)
157 {
158 struct hci_uart *hu = hci_get_drvdata(hdev);
159 u8 alignment = hu->alignment ? hu->alignment : 1;
160
161 /* Check for error from previous call */
162 if (IS_ERR(skb))
163 skb = NULL;
164
165 while (count) {
166 int i, len;
167
168 /* remove padding bytes from buffer */
169 for (; hu->padding && count > 0; hu->padding--) {
170 count--;
171 buffer++;
172 }
173 if (!count)
174 break;
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 hci_skb_pkt_type(skb) = (&pkts[i])->type;
187 hci_skb_expect(skb) = (&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, hci_skb_expect(skb) - skb->len, count);
200 skb_put_data(skb, buffer, len);
201
202 count -= len;
203 buffer += len;
204
205 /* Check for partial packet */
206 if (skb->len < hci_skb_expect(skb))
207 continue;
208
209 for (i = 0; i < pkts_count; i++) {
210 if (hci_skb_pkt_type(skb) == (&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 dlen = 0;
226 break;
227 case 1:
228 /* Single octet variable length */
229 dlen = skb->data[(&pkts[i])->loff];
230 hci_skb_expect(skb) += dlen;
231
232 if (skb_tailroom(skb) < dlen) {
233 kfree_skb(skb);
234 return ERR_PTR(-EMSGSIZE);
235 }
236 break;
237 case 2:
238 /* Double octet variable length */
239 dlen = get_unaligned_le16(skb->data +
240 (&pkts[i])->loff);
241 hci_skb_expect(skb) += dlen;
242
243 if (skb_tailroom(skb) < dlen) {
244 kfree_skb(skb);
245 return ERR_PTR(-EMSGSIZE);
246 }
247 break;
248 default:
249 /* Unsupported variable length */
250 kfree_skb(skb);
251 return ERR_PTR(-EILSEQ);
252 }
253
254 if (!dlen) {
255 hu->padding = (skb->len + 1) % alignment;
256 hu->padding = (alignment - hu->padding) % alignment;
257
258 /* No more data, complete frame */
259 (&pkts[i])->recv(hdev, skb);
260 skb = NULL;
261 }
262 } else {
263 hu->padding = (skb->len + 1) % alignment;
264 hu->padding = (alignment - hu->padding) % alignment;
265
266 /* Complete frame */
267 (&pkts[i])->recv(hdev, skb);
268 skb = NULL;
269 }
270 }
271
272 return skb;
273 }
274 EXPORT_SYMBOL_GPL(h4_recv_buf);
275