1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
|
// 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))
return -EFAULT;
ret = qrtr_endpoint_post(&tun->ep, kbuf, len);
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");
|
