WSL2-Linux-Kernel/drivers/bluetooth/hci_h4.c

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5.4 KiB
C
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
*
* Bluetooth HCI UART driver
*
* Copyright (C) 2000-2001 Qualcomm Incorporated
* Copyright (C) 2002-2003 Maxim Krasnyansky <maxk@qualcomm.com>
* Copyright (C) 2004-2005 Marcel Holtmann <marcel@holtmann.org>
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/interrupt.h>
#include <linux/ptrace.h>
#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/signal.h>
#include <linux/ioctl.h>
#include <linux/skbuff.h>
#include <asm/unaligned.h>
#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>
#include "hci_uart.h"
struct h4_struct {
struct sk_buff *rx_skb;
struct sk_buff_head txq;
};
/* Initialize protocol */
static int h4_open(struct hci_uart *hu)
{
struct h4_struct *h4;
BT_DBG("hu %p", hu);
h4 = kzalloc(sizeof(*h4), GFP_KERNEL);
if (!h4)
return -ENOMEM;
skb_queue_head_init(&h4->txq);
hu->priv = h4;
return 0;
}
/* Flush protocol data */
static int h4_flush(struct hci_uart *hu)
{
struct h4_struct *h4 = hu->priv;
BT_DBG("hu %p", hu);
skb_queue_purge(&h4->txq);
return 0;
}
/* Close protocol */
static int h4_close(struct hci_uart *hu)
{
struct h4_struct *h4 = hu->priv;
BT_DBG("hu %p", hu);
skb_queue_purge(&h4->txq);
kfree_skb(h4->rx_skb);
hu->priv = NULL;
kfree(h4);
return 0;
}
/* Enqueue frame for transmission (padding, crc, etc) */
static int h4_enqueue(struct hci_uart *hu, struct sk_buff *skb)
{
struct h4_struct *h4 = hu->priv;
BT_DBG("hu %p skb %p", hu, skb);
/* Prepend skb with frame type */
memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
skb_queue_tail(&h4->txq, skb);
return 0;
}
static const struct h4_recv_pkt h4_recv_pkts[] = {
{ H4_RECV_ACL, .recv = hci_recv_frame },
{ H4_RECV_SCO, .recv = hci_recv_frame },
{ H4_RECV_EVENT, .recv = hci_recv_frame },
{ H4_RECV_ISO, .recv = hci_recv_frame },
};
/* Recv data */
static int h4_recv(struct hci_uart *hu, const void *data, int count)
{
struct h4_struct *h4 = hu->priv;
if (!test_bit(HCI_UART_REGISTERED, &hu->flags))
return -EUNATCH;
h4->rx_skb = h4_recv_buf(hu->hdev, h4->rx_skb, data, count,
h4_recv_pkts, ARRAY_SIZE(h4_recv_pkts));
if (IS_ERR(h4->rx_skb)) {
int err = PTR_ERR(h4->rx_skb);
bt_dev_err(hu->hdev, "Frame reassembly failed (%d)", err);
h4->rx_skb = NULL;
return err;
}
return count;
}
static struct sk_buff *h4_dequeue(struct hci_uart *hu)
{
struct h4_struct *h4 = hu->priv;
return skb_dequeue(&h4->txq);
}
static const struct hci_uart_proto h4p = {
.id = HCI_UART_H4,
.name = "H4",
.open = h4_open,
.close = h4_close,
.recv = h4_recv,
.enqueue = h4_enqueue,
.dequeue = h4_dequeue,
.flush = h4_flush,
};
int __init h4_init(void)
{
return hci_uart_register_proto(&h4p);
}
int __exit h4_deinit(void)
{
return hci_uart_unregister_proto(&h4p);
}
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)
{
struct hci_uart *hu = hci_get_drvdata(hdev);
u8 alignment = hu->alignment ? hu->alignment : 1;
/* Check for error from previous call */
if (IS_ERR(skb))
skb = NULL;
while (count) {
int i, len;
/* remove padding bytes from buffer */
for (; hu->padding && count > 0; hu->padding--) {
count--;
buffer++;
}
if (!count)
break;
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) {
hu->padding = (skb->len - 1) % alignment;
hu->padding = (alignment - hu->padding) % alignment;
/* No more data, complete frame */
(&pkts[i])->recv(hdev, skb);
skb = NULL;
}
} else {
hu->padding = (skb->len - 1) % alignment;
hu->padding = (alignment - hu->padding) % alignment;
/* Complete frame */
(&pkts[i])->recv(hdev, skb);
skb = NULL;
}
}
return skb;
}
EXPORT_SYMBOL_GPL(h4_recv_buf);