1 // SPDX-License-Identifier: GPL-2.0-or-later
4 * Bluetooth HCI UART driver
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>
11 #include <linux/module.h>
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>
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>
30 #include <net/bluetooth/bluetooth.h>
31 #include <net/bluetooth/hci_core.h>
36 struct sk_buff *rx_skb;
37 struct sk_buff_head txq;
40 /* Initialize protocol */
41 static int h4_open(struct hci_uart *hu)
47 h4 = kzalloc(sizeof(*h4), GFP_KERNEL);
51 skb_queue_head_init(&h4->txq);
57 /* Flush protocol data */
58 static int h4_flush(struct hci_uart *hu)
60 struct h4_struct *h4 = hu->priv;
64 skb_queue_purge(&h4->txq);
70 static int h4_close(struct hci_uart *hu)
72 struct h4_struct *h4 = hu->priv;
78 skb_queue_purge(&h4->txq);
80 kfree_skb(h4->rx_skb);
88 /* Enqueue frame for transmittion (padding, crc, etc) */
89 static int h4_enqueue(struct hci_uart *hu, struct sk_buff *skb)
91 struct h4_struct *h4 = hu->priv;
93 BT_DBG("hu %p skb %p", hu, skb);
95 /* Prepend skb with frame type */
96 memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
97 skb_queue_tail(&h4->txq, skb);
102 static const struct h4_recv_pkt h4_recv_pkts[] = {
103 { H4_RECV_ACL, .recv = hci_recv_frame },
104 { H4_RECV_SCO, .recv = hci_recv_frame },
105 { H4_RECV_EVENT, .recv = hci_recv_frame },
106 { H4_RECV_ISO, .recv = hci_recv_frame },
110 static int h4_recv(struct hci_uart *hu, const void *data, int count)
112 struct h4_struct *h4 = hu->priv;
114 if (!test_bit(HCI_UART_REGISTERED, &hu->flags))
117 h4->rx_skb = h4_recv_buf(hu->hdev, h4->rx_skb, data, count,
118 h4_recv_pkts, ARRAY_SIZE(h4_recv_pkts));
119 if (IS_ERR(h4->rx_skb)) {
120 int err = PTR_ERR(h4->rx_skb);
121 bt_dev_err(hu->hdev, "Frame reassembly failed (%d)", err);
129 static struct sk_buff *h4_dequeue(struct hci_uart *hu)
131 struct h4_struct *h4 = hu->priv;
132 return skb_dequeue(&h4->txq);
135 static const struct hci_uart_proto h4p = {
141 .enqueue = h4_enqueue,
142 .dequeue = h4_dequeue,
146 int __init h4_init(void)
148 return hci_uart_register_proto(&h4p);
151 int __exit h4_deinit(void)
153 return hci_uart_unregister_proto(&h4p);
156 struct sk_buff *h4_recv_buf(struct hci_dev *hdev, struct sk_buff *skb,
157 const unsigned char *buffer, int count,
158 const struct h4_recv_pkt *pkts, int pkts_count)
160 struct hci_uart *hu = hci_get_drvdata(hdev);
161 u8 alignment = hu->alignment ? hu->alignment : 1;
163 /* Check for error from previous call */
170 /* remove padding bytes from buffer */
171 for (; hu->padding && count > 0; hu->padding--) {
179 for (i = 0; i < pkts_count; i++) {
180 if (buffer[0] != (&pkts[i])->type)
183 skb = bt_skb_alloc((&pkts[i])->maxlen,
186 return ERR_PTR(-ENOMEM);
188 hci_skb_pkt_type(skb) = (&pkts[i])->type;
189 hci_skb_expect(skb) = (&pkts[i])->hlen;
193 /* Check for invalid packet type */
195 return ERR_PTR(-EILSEQ);
201 len = min_t(uint, hci_skb_expect(skb) - skb->len, count);
202 skb_put_data(skb, buffer, len);
207 /* Check for partial packet */
208 if (skb->len < hci_skb_expect(skb))
211 for (i = 0; i < pkts_count; i++) {
212 if (hci_skb_pkt_type(skb) == (&pkts[i])->type)
216 if (i >= pkts_count) {
218 return ERR_PTR(-EILSEQ);
221 if (skb->len == (&pkts[i])->hlen) {
224 switch ((&pkts[i])->lsize) {
226 /* No variable data length */
230 /* Single octet variable length */
231 dlen = skb->data[(&pkts[i])->loff];
232 hci_skb_expect(skb) += dlen;
234 if (skb_tailroom(skb) < dlen) {
236 return ERR_PTR(-EMSGSIZE);
240 /* Double octet variable length */
241 dlen = get_unaligned_le16(skb->data +
243 hci_skb_expect(skb) += dlen;
245 if (skb_tailroom(skb) < dlen) {
247 return ERR_PTR(-EMSGSIZE);
251 /* Unsupported variable length */
253 return ERR_PTR(-EILSEQ);
257 hu->padding = (skb->len - 1) % alignment;
258 hu->padding = (alignment - hu->padding) % alignment;
260 /* No more data, complete frame */
261 (&pkts[i])->recv(hdev, skb);
265 hu->padding = (skb->len - 1) % alignment;
266 hu->padding = (alignment - hu->padding) % alignment;
269 (&pkts[i])->recv(hdev, skb);
276 EXPORT_SYMBOL_GPL(h4_recv_buf);