diff options
Diffstat (limited to 'drivers/bluetooth/hci_h4.c')
| -rw-r--r-- | drivers/bluetooth/hci_h4.c | 274 |
1 files changed, 274 insertions, 0 deletions
diff --git a/drivers/bluetooth/hci_h4.c b/drivers/bluetooth/hci_h4.c new file mode 100644 index 000000000..1d0cdf023 --- /dev/null +++ b/drivers/bluetooth/hci_h4.c @@ -0,0 +1,274 @@ +// 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); |