// SPDX-License-Identifier: GPL-2.0-or-later /* * * Bluetooth virtual HCI driver * * Copyright (C) 2000-2001 Qualcomm Incorporated * Copyright (C) 2002-2003 Maxim Krasnyansky <maxk@qualcomm.com> * Copyright (C) 2004-2006 Marcel Holtmann <marcel@holtmann.org> */ #include <linux/module.h> #include <asm/unaligned.h> #include <linux/kernel.h> #include <linux/init.h> #include <linux/slab.h> #include <linux/types.h> #include <linux/errno.h> #include <linux/sched.h> #include <linux/poll.h> #include <linux/skbuff.h> #include <linux/miscdevice.h> #include <net/bluetooth/bluetooth.h> #include <net/bluetooth/hci_core.h> #define VERSION "1.5" static bool amp; struct vhci_data { struct hci_dev *hdev; wait_queue_head_t read_wait; struct sk_buff_head readq; struct mutex open_mutex; struct delayed_work open_timeout; }; static int vhci_open_dev(struct hci_dev *hdev) { return 0; } static int vhci_close_dev(struct hci_dev *hdev) { struct vhci_data *data = hci_get_drvdata(hdev); skb_queue_purge(&data->readq); return 0; } static int vhci_flush(struct hci_dev *hdev) { struct vhci_data *data = hci_get_drvdata(hdev); skb_queue_purge(&data->readq); return 0; } static int vhci_send_frame(struct hci_dev *hdev, struct sk_buff *skb) { struct vhci_data *data = hci_get_drvdata(hdev); memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1); skb_queue_tail(&data->readq, skb); wake_up_interruptible(&data->read_wait); return 0; } static int __vhci_create_device(struct vhci_data *data, __u8 opcode) { struct hci_dev *hdev; struct sk_buff *skb; __u8 dev_type; if (data->hdev) return -EBADFD; /* bits 0-1 are dev_type (Primary or AMP) */ dev_type = opcode & 0x03; if (dev_type != HCI_PRIMARY && dev_type != HCI_AMP) return -EINVAL; /* bits 2-5 are reserved (must be zero) */ if (opcode & 0x3c) return -EINVAL; skb = bt_skb_alloc(4, GFP_KERNEL); if (!skb) return -ENOMEM; hdev = hci_alloc_dev(); if (!hdev) { kfree_skb(skb); return -ENOMEM; } data->hdev = hdev; hdev->bus = HCI_VIRTUAL; hdev->dev_type = dev_type; hci_set_drvdata(hdev, data); hdev->open = vhci_open_dev; hdev->close = vhci_close_dev; hdev->flush = vhci_flush; hdev->send = vhci_send_frame; /* bit 6 is for external configuration */ if (opcode & 0x40) set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks); /* bit 7 is for raw device */ if (opcode & 0x80) set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks); if (hci_register_dev(hdev) < 0) { BT_ERR("Can't register HCI device"); hci_free_dev(hdev); data->hdev = NULL; kfree_skb(skb); return -EBUSY; } hci_skb_pkt_type(skb) = HCI_VENDOR_PKT; skb_put_u8(skb, 0xff); skb_put_u8(skb, opcode); put_unaligned_le16(hdev->id, skb_put(skb, 2)); skb_queue_tail(&data->readq, skb); wake_up_interruptible(&data->read_wait); return 0; } static int vhci_create_device(struct vhci_data *data, __u8 opcode) { int err; mutex_lock(&data->open_mutex); err = __vhci_create_device(data, opcode); mutex_unlock(&data->open_mutex); return err; } static inline ssize_t vhci_get_user(struct vhci_data *data, struct iov_iter *from) { size_t len = iov_iter_count(from); struct sk_buff *skb; __u8 pkt_type, opcode; int ret; if (len < 2 || len > HCI_MAX_FRAME_SIZE) return -EINVAL; skb = bt_skb_alloc(len, GFP_KERNEL); if (!skb) return -ENOMEM; if (!copy_from_iter_full(skb_put(skb, len), len, from)) { kfree_skb(skb); return -EFAULT; } pkt_type = *((__u8 *) skb->data); skb_pull(skb, 1); switch (pkt_type) { case HCI_EVENT_PKT: case HCI_ACLDATA_PKT: case HCI_SCODATA_PKT: case HCI_ISODATA_PKT: if (!data->hdev) { kfree_skb(skb); return -ENODEV; } hci_skb_pkt_type(skb) = pkt_type; ret = hci_recv_frame(data->hdev, skb); break; case HCI_VENDOR_PKT: cancel_delayed_work_sync(&data->open_timeout); opcode = *((__u8 *) skb->data); skb_pull(skb, 1); if (skb->len > 0) { kfree_skb(skb); return -EINVAL; } kfree_skb(skb); ret = vhci_create_device(data, opcode); break; default: kfree_skb(skb); return -EINVAL; } return (ret < 0) ? ret : len; } static inline ssize_t vhci_put_user(struct vhci_data *data, struct sk_buff *skb, char __user *buf, int count) { char __user *ptr = buf; int len; len = min_t(unsigned int, skb->len, count); if (copy_to_user(ptr, skb->data, len)) return -EFAULT; if (!data->hdev) return len; data->hdev->stat.byte_tx += len; switch (hci_skb_pkt_type(skb)) { case HCI_COMMAND_PKT: data->hdev->stat.cmd_tx++; break; case HCI_ACLDATA_PKT: data->hdev->stat.acl_tx++; break; case HCI_SCODATA_PKT: data->hdev->stat.sco_tx++; break; } return len; } static ssize_t vhci_read(struct file *file, char __user *buf, size_t count, loff_t *pos) { struct vhci_data *data = file->private_data; struct sk_buff *skb; ssize_t ret = 0; while (count) { skb = skb_dequeue(&data->readq); if (skb) { ret = vhci_put_user(data, skb, buf, count); if (ret < 0) skb_queue_head(&data->readq, skb); else kfree_skb(skb); break; } if (file->f_flags & O_NONBLOCK) { ret = -EAGAIN; break; } ret = wait_event_interruptible(data->read_wait, !skb_queue_empty(&data->readq)); if (ret < 0) break; } return ret; } static ssize_t vhci_write(struct kiocb *iocb, struct iov_iter *from) { struct file *file = iocb->ki_filp; struct vhci_data *data = file->private_data; return vhci_get_user(data, from); } static __poll_t vhci_poll(struct file *file, poll_table *wait) { struct vhci_data *data = file->private_data; poll_wait(file, &data->read_wait, wait); if (!skb_queue_empty(&data->readq)) return EPOLLIN | EPOLLRDNORM; return EPOLLOUT | EPOLLWRNORM; } static void vhci_open_timeout(struct work_struct *work) { struct vhci_data *data = container_of(work, struct vhci_data, open_timeout.work); vhci_create_device(data, amp ? HCI_AMP : HCI_PRIMARY); } static int vhci_open(struct inode *inode, struct file *file) { struct vhci_data *data; data = kzalloc(sizeof(struct vhci_data), GFP_KERNEL); if (!data) return -ENOMEM; skb_queue_head_init(&data->readq); init_waitqueue_head(&data->read_wait); mutex_init(&data->open_mutex); INIT_DELAYED_WORK(&data->open_timeout, vhci_open_timeout); file->private_data = data; nonseekable_open(inode, file); schedule_delayed_work(&data->open_timeout, msecs_to_jiffies(1000)); return 0; } static int vhci_release(struct inode *inode, struct file *file) { struct vhci_data *data = file->private_data; struct hci_dev *hdev; cancel_delayed_work_sync(&data->open_timeout); hdev = data->hdev; if (hdev) { hci_unregister_dev(hdev); hci_free_dev(hdev); } skb_queue_purge(&data->readq); file->private_data = NULL; kfree(data); return 0; } static const struct file_operations vhci_fops = { .owner = THIS_MODULE, .read = vhci_read, .write_iter = vhci_write, .poll = vhci_poll, .open = vhci_open, .release = vhci_release, .llseek = no_llseek, }; static struct miscdevice vhci_miscdev = { .name = "vhci", .fops = &vhci_fops, .minor = VHCI_MINOR, }; module_misc_device(vhci_miscdev); module_param(amp, bool, 0644); MODULE_PARM_DESC(amp, "Create AMP controller device"); MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>"); MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION); MODULE_VERSION(VERSION); MODULE_LICENSE("GPL"); MODULE_ALIAS("devname:vhci"); MODULE_ALIAS_MISCDEV(VHCI_MINOR);