[linux-2.6-block.git] / net / qrtr / tun.c

// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2018, Linaro Ltd */

#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/poll.h>
#include <linux/skbuff.h>
#include <linux/uaccess.h>

#include "qrtr.h"

struct qrtr_tun {
	struct qrtr_endpoint ep;

	struct sk_buff_head queue;
	wait_queue_head_t readq;
};

static int qrtr_tun_send(struct qrtr_endpoint *ep, struct sk_buff *skb)
{
	struct qrtr_tun *tun = container_of(ep, struct qrtr_tun, ep);

	skb_queue_tail(&tun->queue, skb);

	/* wake up any blocking processes, waiting for new data */
	wake_up_interruptible(&tun->readq);

	return 0;
}

static int qrtr_tun_open(struct inode *inode, struct file *filp)
{
	struct qrtr_tun *tun;

	tun = kzalloc(sizeof(*tun), GFP_KERNEL);
	if (!tun)
		return -ENOMEM;

	skb_queue_head_init(&tun->queue);
	init_waitqueue_head(&tun->readq);

	tun->ep.xmit = qrtr_tun_send;

	filp->private_data = tun;

	return qrtr_endpoint_register(&tun->ep, QRTR_EP_NID_AUTO);
}

static ssize_t qrtr_tun_read_iter(struct kiocb *iocb, struct iov_iter *to)
{
	struct file *filp = iocb->ki_filp;
	struct qrtr_tun *tun = filp->private_data;
	struct sk_buff *skb;
	int count;

	while (!(skb = skb_dequeue(&tun->queue))) {
		if (filp->f_flags & O_NONBLOCK)
			return -EAGAIN;

		/* Wait until we get data or the endpoint goes away */
		if (wait_event_interruptible(tun->readq,
					     !skb_queue_empty(&tun->queue)))
			return -ERESTARTSYS;
	}

	count = min_t(size_t, iov_iter_count(to), skb->len);
	if (copy_to_iter(skb->data, count, to) != count)
		count = -EFAULT;

	kfree_skb(skb);

	return count;
}

static ssize_t qrtr_tun_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
	struct file *filp = iocb->ki_filp;
	struct qrtr_tun *tun = filp->private_data;
	size_t len = iov_iter_count(from);
	ssize_t ret;
	void *kbuf;

	kbuf = kzalloc(len, GFP_KERNEL);
	if (!kbuf)
		return -ENOMEM;

	if (!copy_from_iter_full(kbuf, len, from)) {
		kfree(kbuf);
		return -EFAULT;
	}

	ret = qrtr_endpoint_post(&tun->ep, kbuf, len);

	kfree(kbuf);
	return ret < 0 ? ret : len;
}

static __poll_t qrtr_tun_poll(struct file *filp, poll_table *wait)
{
	struct qrtr_tun *tun = filp->private_data;
	__poll_t mask = 0;

	poll_wait(filp, &tun->readq, wait);

	if (!skb_queue_empty(&tun->queue))
		mask |= EPOLLIN | EPOLLRDNORM;

	return mask;
}

static int qrtr_tun_release(struct inode *inode, struct file *filp)
{
	struct qrtr_tun *tun = filp->private_data;
	struct sk_buff *skb;

	qrtr_endpoint_unregister(&tun->ep);

	/* Discard all SKBs */
	while (!skb_queue_empty(&tun->queue)) {
		skb = skb_dequeue(&tun->queue);
		kfree_skb(skb);
	}

	kfree(tun);

	return 0;
}

static const struct file_operations qrtr_tun_ops = {
	.owner = THIS_MODULE,
	.open = qrtr_tun_open,
	.poll = qrtr_tun_poll,
	.read_iter = qrtr_tun_read_iter,
	.write_iter = qrtr_tun_write_iter,
	.release = qrtr_tun_release,
};

static struct miscdevice qrtr_tun_miscdev = {
	MISC_DYNAMIC_MINOR,
	"qrtr-tun",
	&qrtr_tun_ops,
};

static int __init qrtr_tun_init(void)
{
	int ret;

	ret = misc_register(&qrtr_tun_miscdev);
	if (ret)
		pr_err("failed to register Qualcomm IPC Router tun device\n");

	return ret;
}

static void __exit qrtr_tun_exit(void)
{
	misc_deregister(&qrtr_tun_miscdev);
}

module_init(qrtr_tun_init);
module_exit(qrtr_tun_exit);

MODULE_DESCRIPTION("Qualcomm IPC Router TUN device");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
28fb4e59 BA	1	// SPDX-License-Identifier: GPL-2.0
	2	/* Copyright (c) 2018, Linaro Ltd */
	3
	4	#include <linux/miscdevice.h>
	5	#include <linux/module.h>
	6	#include <linux/poll.h>
	7	#include <linux/skbuff.h>
	8	#include <linux/uaccess.h>
	9
	10	#include "qrtr.h"
	11
	12	struct qrtr_tun {
	13	struct qrtr_endpoint ep;
	14
	15	struct sk_buff_head queue;
	16	wait_queue_head_t readq;
	17	};
	18
	19	static int qrtr_tun_send(struct qrtr_endpoint ep, struct sk_buff skb)
	20	{
	21	struct qrtr_tun *tun = container_of(ep, struct qrtr_tun, ep);
	22
	23	skb_queue_tail(&tun->queue, skb);
	24
	25	/* wake up any blocking processes, waiting for new data */
	26	wake_up_interruptible(&tun->readq);
	27
	28	return 0;
	29	}
	30
	31	static int qrtr_tun_open(struct inode inode, struct file filp)
	32	{
	33	struct qrtr_tun *tun;
	34
	35	tun = kzalloc(sizeof(*tun), GFP_KERNEL);
	36	if (!tun)
	37	return -ENOMEM;
	38
	39	skb_queue_head_init(&tun->queue);
	40	init_waitqueue_head(&tun->readq);
	41
	42	tun->ep.xmit = qrtr_tun_send;
	43
	44	filp->private_data = tun;
	45
	46	return qrtr_endpoint_register(&tun->ep, QRTR_EP_NID_AUTO);
	47	}
	48
	49	static ssize_t qrtr_tun_read_iter(struct kiocb iocb, struct iov_iter to)
	50	{
	51	struct file *filp = iocb->ki_filp;
	52	struct qrtr_tun *tun = filp->private_data;
	53	struct sk_buff *skb;
	54	int count;
	55
	56	while (!(skb = skb_dequeue(&tun->queue))) {
	57	if (filp->f_flags & O_NONBLOCK)
	58	return -EAGAIN;
	59
	60	/* Wait until we get data or the endpoint goes away */
	61	if (wait_event_interruptible(tun->readq,
	62	!skb_queue_empty(&tun->queue)))
	63	return -ERESTARTSYS;
	64	}
65
66	count = min_t(size_t, iov_iter_count(to), skb->len);
67	if (copy_to_iter(skb->data, count, to) != count)
68	count = -EFAULT;
69
70	kfree_skb(skb);
71
72	return count;
73	}
74
75	static ssize_t qrtr_tun_write_iter(struct kiocb iocb, struct iov_iter from)
76	{
77	struct file *filp = iocb->ki_filp;
78	struct qrtr_tun *tun = filp->private_data;
79	size_t len = iov_iter_count(from);
80	ssize_t ret;
81	void *kbuf;
82
83	kbuf = kzalloc(len, GFP_KERNEL);
84	if (!kbuf)
85	return -ENOMEM;
86
a21b7f0c NE	87	if (!copy_from_iter_full(kbuf, len, from)) {
a21b7f0c NE	88	kfree(kbuf);
28fb4e59	89	return -EFAULT;
a21b7f0c	90	}
28fb4e59 BA	91
	92	ret = qrtr_endpoint_post(&tun->ep, kbuf, len);
	93
a21b7f0c	94	kfree(kbuf);
28fb4e59 BA	95	return ret < 0 ? ret : len;
	96	}
	97
	98	static __poll_t qrtr_tun_poll(struct file filp, poll_table wait)
	99	{
	100	struct qrtr_tun *tun = filp->private_data;
	101	__poll_t mask = 0;
	102
	103	poll_wait(filp, &tun->readq, wait);
	104
	105	if (!skb_queue_empty(&tun->queue))
	106	mask \|= EPOLLIN \| EPOLLRDNORM;
	107
	108	return mask;
	109	}
	110
	111	static int qrtr_tun_release(struct inode inode, struct file filp)
	112	{
	113	struct qrtr_tun *tun = filp->private_data;
	114	struct sk_buff *skb;
	115
	116	qrtr_endpoint_unregister(&tun->ep);
	117
	118	/* Discard all SKBs */
	119	while (!skb_queue_empty(&tun->queue)) {
	120	skb = skb_dequeue(&tun->queue);
	121	kfree_skb(skb);
	122	}
	123
	124	kfree(tun);
	125
	126	return 0;
	127	}
	128
	129	static const struct file_operations qrtr_tun_ops = {
	130	.owner = THIS_MODULE,
	131	.open = qrtr_tun_open,
	132	.poll = qrtr_tun_poll,
	133	.read_iter = qrtr_tun_read_iter,
	134	.write_iter = qrtr_tun_write_iter,
	135	.release = qrtr_tun_release,
	136	};
	137
	138	static struct miscdevice qrtr_tun_miscdev = {
	139	MISC_DYNAMIC_MINOR,
	140	"qrtr-tun",
	141	&qrtr_tun_ops,
	142	};
	143
	144	static int __init qrtr_tun_init(void)
	145	{
	146	int ret;
	147
	148	ret = misc_register(&qrtr_tun_miscdev);
	149	if (ret)
	150	pr_err("failed to register Qualcomm IPC Router tun device\n");
	151
	152	return ret;
	153	}
	154
	155	static void __exit qrtr_tun_exit(void)
	156	{
	157	misc_deregister(&qrtr_tun_miscdev);
	158	}
159
160	module_init(qrtr_tun_init);
161	module_exit(qrtr_tun_exit);
162
163	MODULE_DESCRIPTION("Qualcomm IPC Router TUN device");
164	MODULE_LICENSE("GPL v2");