summaryrefslogtreecommitdiffstats
path: root/drivers/bluetooth/h4_recv.h
blob: 87ccaceadba72a544ffcc7b6fc7669f72cf94463 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
/*
 *
 *  Generic Bluetooth HCI UART driver
 *
 *  Copyright (C) 2015-2018  Intel Corporation
 *
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include <asm/unaligned.h>

struct h4_recv_pkt {
	u8  type;	/* Packet type */
	u8  hlen;	/* Header length */
	u8  loff;	/* Data length offset in header */
	u8  lsize;	/* Data length field size */
	u16 maxlen;	/* Max overall packet length */
	int (*recv)(struct hci_dev *hdev, struct sk_buff *skb);
};

#define H4_RECV_ACL \
	.type = HCI_ACLDATA_PKT, \
	.hlen = HCI_ACL_HDR_SIZE, \
	.loff = 2, \
	.lsize = 2, \
	.maxlen = HCI_MAX_FRAME_SIZE \

#define H4_RECV_SCO \
	.type = HCI_SCODATA_PKT, \
	.hlen = HCI_SCO_HDR_SIZE, \
	.loff = 2, \
	.lsize = 1, \
	.maxlen = HCI_MAX_SCO_SIZE

#define H4_RECV_EVENT \
	.type = HCI_EVENT_PKT, \
	.hlen = HCI_EVENT_HDR_SIZE, \
	.loff = 1, \
	.lsize = 1, \
	.maxlen = HCI_MAX_EVENT_SIZE

static inline struct sk_buff *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)
{
	/* Check for error from previous call */
	if (IS_ERR(skb))
		skb = NULL;

	while (count) {
		int i, len;

		if (!skb) {
			for (i = 0; i < pkts_count; i++) {
				if (buffer[0] != (&pkts[i])->type)
					continue;

				skb = bt_skb_alloc((&pkts[i])->maxlen,
						   GFP_ATOMIC);
				if (!skb)
					return ERR_PTR(-ENOMEM);

				hci_skb_pkt_type(skb) = (&pkts[i])->type;
				hci_skb_expect(skb) = (&pkts[i])->hlen;
				break;
			}

			/* Check for invalid packet type */
			if (!skb)
				return ERR_PTR(-EILSEQ);

			count -= 1;
			buffer += 1;
		}

		len = min_t(uint, hci_skb_expect(skb) - skb->len, count);
		skb_put_data(skb, buffer, len);

		count -= len;
		buffer += len;

		/* Check for partial packet */
		if (skb->len < hci_skb_expect(skb))
			continue;

		for (i = 0; i < pkts_count; i++) {
			if (hci_skb_pkt_type(skb) == (&pkts[i])->type)
				break;
		}

		if (i >= pkts_count) {
			kfree_skb(skb);
			return ERR_PTR(-EILSEQ);
		}

		if (skb->len == (&pkts[i])->hlen) {
			u16 dlen;

			switch ((&pkts[i])->lsize) {
			case 0:
				/* No variable data length */
				dlen = 0;
				break;
			case 1:
				/* Single octet variable length */
				dlen = skb->data[(&pkts[i])->loff];
				hci_skb_expect(skb) += dlen;

				if (skb_tailroom(skb) < dlen) {
					kfree_skb(skb);
					return ERR_PTR(-EMSGSIZE);
				}
				break;
			case 2:
				/* Double octet variable length */
				dlen = get_unaligned_le16(skb->data +
							  (&pkts[i])->loff);
				hci_skb_expect(skb) += dlen;

				if (skb_tailroom(skb) < dlen) {
					kfree_skb(skb);
					return ERR_PTR(-EMSGSIZE);
				}
				break;
			default:
				/* Unsupported variable length */
				kfree_skb(skb);
				return ERR_PTR(-EILSEQ);
			}

			if (!dlen) {
				/* No more data, complete frame */
				(&pkts[i])->recv(hdev, skb);
				skb = NULL;
			}
		} else {
			/* Complete frame */
			(&pkts[i])->recv(hdev, skb);
			skb = NULL;
		}
	}

	return skb;
}