[linux-block.git] / drivers / nfc / virtual_ncidev.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Virtual NCI device simulation driver
 *
 * Copyright (C) 2020 Samsung Electrnoics
 * Bongsu Jeon <bongsu.jeon@samsung.com>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/miscdevice.h>
#include <linux/mutex.h>
#include <linux/wait.h>
#include <net/nfc/nci_core.h>

#define IOCTL_GET_NCIDEV_IDX    0
#define VIRTUAL_NFC_PROTOCOLS	(NFC_PROTO_JEWEL_MASK | \
				 NFC_PROTO_MIFARE_MASK | \
				 NFC_PROTO_FELICA_MASK | \
				 NFC_PROTO_ISO14443_MASK | \
				 NFC_PROTO_ISO14443_B_MASK | \
				 NFC_PROTO_ISO15693_MASK)

struct virtual_nci_dev {
	struct nci_dev *ndev;
	struct mutex mtx;
	struct sk_buff *send_buff;
	struct wait_queue_head wq;
	bool running;
};

static int virtual_nci_open(struct nci_dev *ndev)
{
	struct virtual_nci_dev *vdev = nci_get_drvdata(ndev);

	vdev->running = true;
	return 0;
}

static int virtual_nci_close(struct nci_dev *ndev)
{
	struct virtual_nci_dev *vdev = nci_get_drvdata(ndev);

	mutex_lock(&vdev->mtx);
	kfree_skb(vdev->send_buff);
	vdev->send_buff = NULL;
	vdev->running = false;
	mutex_unlock(&vdev->mtx);

	return 0;
}

static int virtual_nci_send(struct nci_dev *ndev, struct sk_buff *skb)
{
	struct virtual_nci_dev *vdev = nci_get_drvdata(ndev);

	mutex_lock(&vdev->mtx);
	if (vdev->send_buff || !vdev->running) {
		mutex_unlock(&vdev->mtx);
		kfree_skb(skb);
		return -1;
	}
	vdev->send_buff = skb_copy(skb, GFP_KERNEL);
	if (!vdev->send_buff) {
		mutex_unlock(&vdev->mtx);
		kfree_skb(skb);
		return -1;
	}
	mutex_unlock(&vdev->mtx);
	wake_up_interruptible(&vdev->wq);
	consume_skb(skb);

	return 0;
}

static const struct nci_ops virtual_nci_ops = {
	.open = virtual_nci_open,
	.close = virtual_nci_close,
	.send = virtual_nci_send
};

static ssize_t virtual_ncidev_read(struct file *file, char __user *buf,
				   size_t count, loff_t *ppos)
{
	struct virtual_nci_dev *vdev = file->private_data;
	size_t actual_len;

	mutex_lock(&vdev->mtx);
	while (!vdev->send_buff) {
		mutex_unlock(&vdev->mtx);
		if (wait_event_interruptible(vdev->wq, vdev->send_buff))
			return -EFAULT;
		mutex_lock(&vdev->mtx);
	}

	actual_len = min_t(size_t, count, vdev->send_buff->len);

	if (copy_to_user(buf, vdev->send_buff->data, actual_len)) {
		mutex_unlock(&vdev->mtx);
		return -EFAULT;
	}

	skb_pull(vdev->send_buff, actual_len);
	if (vdev->send_buff->len == 0) {
		consume_skb(vdev->send_buff);
		vdev->send_buff = NULL;
	}
	mutex_unlock(&vdev->mtx);

	return actual_len;
}

static ssize_t virtual_ncidev_write(struct file *file,
				    const char __user *buf,
				    size_t count, loff_t *ppos)
{
	struct virtual_nci_dev *vdev = file->private_data;
	struct sk_buff *skb;

	skb = alloc_skb(count, GFP_KERNEL);
	if (!skb)
		return -ENOMEM;

	if (copy_from_user(skb_put(skb, count), buf, count)) {
		kfree_skb(skb);
		return -EFAULT;
	}

	nci_recv_frame(vdev->ndev, skb);
	return count;
}

static int virtual_ncidev_open(struct inode *inode, struct file *file)
{
	int ret = 0;
	struct virtual_nci_dev *vdev;

	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
	if (!vdev)
		return -ENOMEM;
	vdev->ndev = nci_allocate_device(&virtual_nci_ops,
		VIRTUAL_NFC_PROTOCOLS, 0, 0);
	if (!vdev->ndev) {
		kfree(vdev);
		return -ENOMEM;
	}

	mutex_init(&vdev->mtx);
	init_waitqueue_head(&vdev->wq);
	file->private_data = vdev;
	nci_set_drvdata(vdev->ndev, vdev);

	ret = nci_register_device(vdev->ndev);
	if (ret < 0) {
		nci_free_device(vdev->ndev);
		mutex_destroy(&vdev->mtx);
		kfree(vdev);
		return ret;
	}

	return 0;
}

static int virtual_ncidev_close(struct inode *inode, struct file *file)
{
	struct virtual_nci_dev *vdev = file->private_data;

	nci_unregister_device(vdev->ndev);
	nci_free_device(vdev->ndev);
	mutex_destroy(&vdev->mtx);
	kfree(vdev);

	return 0;
}

static long virtual_ncidev_ioctl(struct file *file, unsigned int cmd,
				 unsigned long arg)
{
	struct virtual_nci_dev *vdev = file->private_data;
	const struct nfc_dev *nfc_dev = vdev->ndev->nfc_dev;
	void __user *p = (void __user *)arg;

	if (cmd != IOCTL_GET_NCIDEV_IDX)
		return -ENOTTY;

	if (copy_to_user(p, &nfc_dev->idx, sizeof(nfc_dev->idx)))
		return -EFAULT;

	return 0;
}

static const struct file_operations virtual_ncidev_fops = {
	.owner = THIS_MODULE,
	.read = virtual_ncidev_read,
	.write = virtual_ncidev_write,
	.open = virtual_ncidev_open,
	.release = virtual_ncidev_close,
	.unlocked_ioctl = virtual_ncidev_ioctl
};

static struct miscdevice miscdev = {
	.minor = MISC_DYNAMIC_MINOR,
	.name = "virtual_nci",
	.fops = &virtual_ncidev_fops,
	.mode = 0600,
};

module_misc_device(miscdev);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Virtual NCI device simulation driver");
MODULE_AUTHOR("Bongsu Jeon <bongsu.jeon@samsung.com>");
Commit	Line	Data
e624e6c3 BJ	1	// SPDX-License-Identifier: GPL-2.0-or-later
	2	/*
	3	* Virtual NCI device simulation driver
	4	*
	5	* Copyright (C) 2020 Samsung Electrnoics
	6	* Bongsu Jeon <bongsu.jeon@samsung.com>
	7	*/
	8
	9	#include <linux/kernel.h>
	10	#include <linux/module.h>
	11	#include <linux/miscdevice.h>
	12	#include <linux/mutex.h>
8675569d	13	#include <linux/wait.h>
e624e6c3 BJ	14	#include <net/nfc/nci_core.h>
e624e6c3 BJ	15
e624e6c3 BJ	16	#define IOCTL_GET_NCIDEV_IDX 0
	17	#define VIRTUAL_NFC_PROTOCOLS (NFC_PROTO_JEWEL_MASK \| \
	18	NFC_PROTO_MIFARE_MASK \| \
	19	NFC_PROTO_FELICA_MASK \| \
	20	NFC_PROTO_ISO14443_MASK \| \
	21	NFC_PROTO_ISO14443_B_MASK \| \
	22	NFC_PROTO_ISO15693_MASK)
	23
b2e44aac DV	24	struct virtual_nci_dev {
	25	struct nci_dev *ndev;
	26	struct mutex mtx;
	27	struct sk_buff *send_buff;
	28	struct wait_queue_head wq;
84d2db91	29	bool running;
b2e44aac	30	};
e624e6c3 BJ	31
	32	static int virtual_nci_open(struct nci_dev *ndev)
	33	{
84d2db91 NDP	34	struct virtual_nci_dev *vdev = nci_get_drvdata(ndev);
	35
	36	vdev->running = true;
e624e6c3 BJ	37	return 0;
	38	}
	39
	40	static int virtual_nci_close(struct nci_dev *ndev)
	41	{
b2e44aac DV	42	struct virtual_nci_dev *vdev = nci_get_drvdata(ndev);
	43
	44	mutex_lock(&vdev->mtx);
	45	kfree_skb(vdev->send_buff);
	46	vdev->send_buff = NULL;
84d2db91	47	vdev->running = false;
b2e44aac	48	mutex_unlock(&vdev->mtx);
e624e6c3 BJ	49
	50	return 0;
	51	}
	52
	53	static int virtual_nci_send(struct nci_dev ndev, struct sk_buff skb)
	54	{
b2e44aac DV	55	struct virtual_nci_dev *vdev = nci_get_drvdata(ndev);
	56
	57	mutex_lock(&vdev->mtx);
84d2db91	58	if (vdev->send_buff \|\| !vdev->running) {
b2e44aac	59	mutex_unlock(&vdev->mtx);
e840d8f4	60	kfree_skb(skb);
b2e44aac	61	return -1;
e624e6c3	62	}
b2e44aac DV	63	vdev->send_buff = skb_copy(skb, GFP_KERNEL);
	64	if (!vdev->send_buff) {
	65	mutex_unlock(&vdev->mtx);
e840d8f4	66	kfree_skb(skb);
e624e6c3 BJ	67	return -1;
e624e6c3 BJ	68	}
b2e44aac DV	69	mutex_unlock(&vdev->mtx);
b2e44aac DV	70	wake_up_interruptible(&vdev->wq);
e840d8f4	71	consume_skb(skb);
e624e6c3 BJ	72
	73	return 0;
	74	}
	75
b9c28286	76	static const struct nci_ops virtual_nci_ops = {
e624e6c3 BJ	77	.open = virtual_nci_open,
	78	.close = virtual_nci_close,
	79	.send = virtual_nci_send
	80	};
	81
	82	static ssize_t virtual_ncidev_read(struct file file, char __user buf,
	83	size_t count, loff_t *ppos)
	84	{
b2e44aac	85	struct virtual_nci_dev *vdev = file->private_data;
e624e6c3 BJ	86	size_t actual_len;
e624e6c3 BJ	87
b2e44aac DV	88	mutex_lock(&vdev->mtx);
	89	while (!vdev->send_buff) {
	90	mutex_unlock(&vdev->mtx);
	91	if (wait_event_interruptible(vdev->wq, vdev->send_buff))
8675569d	92	return -EFAULT;
b2e44aac	93	mutex_lock(&vdev->mtx);
e624e6c3 BJ	94	}
e624e6c3 BJ	95
b2e44aac	96	actual_len = min_t(size_t, count, vdev->send_buff->len);
e624e6c3	97
b2e44aac DV	98	if (copy_to_user(buf, vdev->send_buff->data, actual_len)) {
b2e44aac DV	99	mutex_unlock(&vdev->mtx);
e624e6c3 BJ	100	return -EFAULT;
	101	}
	102
b2e44aac DV	103	skb_pull(vdev->send_buff, actual_len);
	104	if (vdev->send_buff->len == 0) {
	105	consume_skb(vdev->send_buff);
	106	vdev->send_buff = NULL;
e624e6c3	107	}
b2e44aac	108	mutex_unlock(&vdev->mtx);
e624e6c3 BJ	109
	110	return actual_len;
	111	}
	112
	113	static ssize_t virtual_ncidev_write(struct file *file,
	114	const char __user *buf,
	115	size_t count, loff_t *ppos)
	116	{
b2e44aac	117	struct virtual_nci_dev *vdev = file->private_data;
e624e6c3 BJ	118	struct sk_buff *skb;
	119
	120	skb = alloc_skb(count, GFP_KERNEL);
	121	if (!skb)
	122	return -ENOMEM;
	123
	124	if (copy_from_user(skb_put(skb, count), buf, count)) {
	125	kfree_skb(skb);
	126	return -EFAULT;
	127	}
	128
b2e44aac	129	nci_recv_frame(vdev->ndev, skb);
e624e6c3 BJ	130	return count;
	131	}
	132
	133	static int virtual_ncidev_open(struct inode inode, struct file file)
	134	{
	135	int ret = 0;
b2e44aac	136	struct virtual_nci_dev *vdev;
e624e6c3	137
b2e44aac DV	138	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
	139	if (!vdev)
	140	return -ENOMEM;
	141	vdev->ndev = nci_allocate_device(&virtual_nci_ops,
	142	VIRTUAL_NFC_PROTOCOLS, 0, 0);
	143	if (!vdev->ndev) {
	144	kfree(vdev);
e624e6c3 BJ	145	return -ENOMEM;
	146	}
	147
b2e44aac DV	148	mutex_init(&vdev->mtx);
	149	init_waitqueue_head(&vdev->wq);
	150	file->private_data = vdev;
	151	nci_set_drvdata(vdev->ndev, vdev);
	152
	153	ret = nci_register_device(vdev->ndev);
e624e6c3	154	if (ret < 0) {
b2e44aac DV	155	nci_free_device(vdev->ndev);
	156	mutex_destroy(&vdev->mtx);
	157	kfree(vdev);
e624e6c3 BJ	158	return ret;
e624e6c3 BJ	159	}
e624e6c3 BJ	160
	161	return 0;
	162	}
	163
	164	static int virtual_ncidev_close(struct inode inode, struct file file)
	165	{
b2e44aac	166	struct virtual_nci_dev *vdev = file->private_data;
e624e6c3	167
b2e44aac DV	168	nci_unregister_device(vdev->ndev);
	169	nci_free_device(vdev->ndev);
	170	mutex_destroy(&vdev->mtx);
	171	kfree(vdev);
e624e6c3 BJ	172
	173	return 0;
	174	}
	175
b2e44aac	176	static long virtual_ncidev_ioctl(struct file *file, unsigned int cmd,
e624e6c3 BJ	177	unsigned long arg)
e624e6c3 BJ	178	{
b2e44aac DV	179	struct virtual_nci_dev *vdev = file->private_data;
b2e44aac DV	180	const struct nfc_dev *nfc_dev = vdev->ndev->nfc_dev;
e624e6c3 BJ	181	void __user p = (void __user )arg;
	182
	183	if (cmd != IOCTL_GET_NCIDEV_IDX)
	184	return -ENOTTY;
	185
	186	if (copy_to_user(p, &nfc_dev->idx, sizeof(nfc_dev->idx)))
	187	return -EFAULT;
	188
	189	return 0;
	190	}
	191
	192	static const struct file_operations virtual_ncidev_fops = {
	193	.owner = THIS_MODULE,
	194	.read = virtual_ncidev_read,
	195	.write = virtual_ncidev_write,
	196	.open = virtual_ncidev_open,
	197	.release = virtual_ncidev_close,
	198	.unlocked_ioctl = virtual_ncidev_ioctl
	199	};
	200
b2e44aac DV	201	static struct miscdevice miscdev = {
	202	.minor = MISC_DYNAMIC_MINOR,
	203	.name = "virtual_nci",
	204	.fops = &virtual_ncidev_fops,
	205	.mode = 0600,
	206	};
	207
61a9b174	208	module_misc_device(miscdev);
e624e6c3 BJ	209
	210	MODULE_LICENSE("GPL");
	211	MODULE_DESCRIPTION("Virtual NCI device simulation driver");
	212	MODULE_AUTHOR("Bongsu Jeon <bongsu.jeon@samsung.com>");