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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>
13#include <linux/wait.h>
14#include <net/nfc/nci_core.h>
15
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
24struct virtual_nci_dev {
25 struct nci_dev *ndev;
26 struct mutex mtx;
27 struct sk_buff *send_buff;
28 struct wait_queue_head wq;
29};
30
31static int virtual_nci_open(struct nci_dev *ndev)
32{
33 return 0;
34}
35
36static int virtual_nci_close(struct nci_dev *ndev)
37{
38 struct virtual_nci_dev *vdev = nci_get_drvdata(ndev);
39
40 mutex_lock(&vdev->mtx);
41 kfree_skb(vdev->send_buff);
42 vdev->send_buff = NULL;
43 mutex_unlock(&vdev->mtx);
44
45 return 0;
46}
47
48static int virtual_nci_send(struct nci_dev *ndev, struct sk_buff *skb)
49{
50 struct virtual_nci_dev *vdev = nci_get_drvdata(ndev);
51
52 mutex_lock(&vdev->mtx);
53 if (vdev->send_buff) {
54 mutex_unlock(&vdev->mtx);
55 kfree_skb(skb);
56 return -1;
57 }
58 vdev->send_buff = skb_copy(skb, GFP_KERNEL);
59 if (!vdev->send_buff) {
60 mutex_unlock(&vdev->mtx);
61 kfree_skb(skb);
62 return -1;
63 }
64 mutex_unlock(&vdev->mtx);
65 wake_up_interruptible(&vdev->wq);
66 consume_skb(skb);
67
68 return 0;
69}
70
71static const struct nci_ops virtual_nci_ops = {
72 .open = virtual_nci_open,
73 .close = virtual_nci_close,
74 .send = virtual_nci_send
75};
76
77static ssize_t virtual_ncidev_read(struct file *file, char __user *buf,
78 size_t count, loff_t *ppos)
79{
80 struct virtual_nci_dev *vdev = file->private_data;
81 size_t actual_len;
82
83 mutex_lock(&vdev->mtx);
84 while (!vdev->send_buff) {
85 mutex_unlock(&vdev->mtx);
86 if (wait_event_interruptible(vdev->wq, vdev->send_buff))
87 return -EFAULT;
88 mutex_lock(&vdev->mtx);
89 }
90
91 actual_len = min_t(size_t, count, vdev->send_buff->len);
92
93 if (copy_to_user(buf, vdev->send_buff->data, actual_len)) {
94 mutex_unlock(&vdev->mtx);
95 return -EFAULT;
96 }
97
98 skb_pull(vdev->send_buff, actual_len);
99 if (vdev->send_buff->len == 0) {
100 consume_skb(vdev->send_buff);
101 vdev->send_buff = NULL;
102 }
103 mutex_unlock(&vdev->mtx);
104
105 return actual_len;
106}
107
108static ssize_t virtual_ncidev_write(struct file *file,
109 const char __user *buf,
110 size_t count, loff_t *ppos)
111{
112 struct virtual_nci_dev *vdev = file->private_data;
113 struct sk_buff *skb;
114
115 skb = alloc_skb(count, GFP_KERNEL);
116 if (!skb)
117 return -ENOMEM;
118
119 if (copy_from_user(skb_put(skb, count), buf, count)) {
120 kfree_skb(skb);
121 return -EFAULT;
122 }
123
124 nci_recv_frame(vdev->ndev, skb);
125 return count;
126}
127
128static int virtual_ncidev_open(struct inode *inode, struct file *file)
129{
130 int ret = 0;
131 struct virtual_nci_dev *vdev;
132
133 vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
134 if (!vdev)
135 return -ENOMEM;
136 vdev->ndev = nci_allocate_device(&virtual_nci_ops,
137 VIRTUAL_NFC_PROTOCOLS, 0, 0);
138 if (!vdev->ndev) {
139 kfree(vdev);
140 return -ENOMEM;
141 }
142
143 mutex_init(&vdev->mtx);
144 init_waitqueue_head(&vdev->wq);
145 file->private_data = vdev;
146 nci_set_drvdata(vdev->ndev, vdev);
147
148 ret = nci_register_device(vdev->ndev);
149 if (ret < 0) {
150 nci_free_device(vdev->ndev);
151 mutex_destroy(&vdev->mtx);
152 kfree(vdev);
153 return ret;
154 }
155
156 return 0;
157}
158
159static int virtual_ncidev_close(struct inode *inode, struct file *file)
160{
161 struct virtual_nci_dev *vdev = file->private_data;
162
163 nci_unregister_device(vdev->ndev);
164 nci_free_device(vdev->ndev);
165 mutex_destroy(&vdev->mtx);
166 kfree(vdev);
167
168 return 0;
169}
170
171static long virtual_ncidev_ioctl(struct file *file, unsigned int cmd,
172 unsigned long arg)
173{
174 struct virtual_nci_dev *vdev = file->private_data;
175 const struct nfc_dev *nfc_dev = vdev->ndev->nfc_dev;
176 void __user *p = (void __user *)arg;
177
178 if (cmd != IOCTL_GET_NCIDEV_IDX)
179 return -ENOTTY;
180
181 if (copy_to_user(p, &nfc_dev->idx, sizeof(nfc_dev->idx)))
182 return -EFAULT;
183
184 return 0;
185}
186
187static const struct file_operations virtual_ncidev_fops = {
188 .owner = THIS_MODULE,
189 .read = virtual_ncidev_read,
190 .write = virtual_ncidev_write,
191 .open = virtual_ncidev_open,
192 .release = virtual_ncidev_close,
193 .unlocked_ioctl = virtual_ncidev_ioctl
194};
195
196static struct miscdevice miscdev = {
197 .minor = MISC_DYNAMIC_MINOR,
198 .name = "virtual_nci",
199 .fops = &virtual_ncidev_fops,
200 .mode = 0600,
201};
202
203static int __init virtual_ncidev_init(void)
204{
205 return misc_register(&miscdev);
206}
207
208static void __exit virtual_ncidev_exit(void)
209{
210 misc_deregister(&miscdev);
211}
212
213module_init(virtual_ncidev_init);
214module_exit(virtual_ncidev_exit);
215
216MODULE_LICENSE("GPL");
217MODULE_DESCRIPTION("Virtual NCI device simulation driver");
218MODULE_AUTHOR("Bongsu Jeon <bongsu.jeon@samsung.com>");
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>
13#include <net/nfc/nci_core.h>
14
15enum virtual_ncidev_mode {
16 virtual_ncidev_enabled,
17 virtual_ncidev_disabled,
18 virtual_ncidev_disabling,
19};
20
21#define IOCTL_GET_NCIDEV_IDX 0
22#define VIRTUAL_NFC_PROTOCOLS (NFC_PROTO_JEWEL_MASK | \
23 NFC_PROTO_MIFARE_MASK | \
24 NFC_PROTO_FELICA_MASK | \
25 NFC_PROTO_ISO14443_MASK | \
26 NFC_PROTO_ISO14443_B_MASK | \
27 NFC_PROTO_ISO15693_MASK)
28
29static enum virtual_ncidev_mode state;
30static struct miscdevice miscdev;
31static struct sk_buff *send_buff;
32static struct nci_dev *ndev;
33static DEFINE_MUTEX(nci_mutex);
34
35static int virtual_nci_open(struct nci_dev *ndev)
36{
37 return 0;
38}
39
40static int virtual_nci_close(struct nci_dev *ndev)
41{
42 mutex_lock(&nci_mutex);
43 kfree_skb(send_buff);
44 send_buff = NULL;
45 mutex_unlock(&nci_mutex);
46
47 return 0;
48}
49
50static int virtual_nci_send(struct nci_dev *ndev, struct sk_buff *skb)
51{
52 mutex_lock(&nci_mutex);
53 if (state != virtual_ncidev_enabled) {
54 mutex_unlock(&nci_mutex);
55 return 0;
56 }
57
58 if (send_buff) {
59 mutex_unlock(&nci_mutex);
60 return -1;
61 }
62 send_buff = skb_copy(skb, GFP_KERNEL);
63 mutex_unlock(&nci_mutex);
64
65 return 0;
66}
67
68static struct nci_ops virtual_nci_ops = {
69 .open = virtual_nci_open,
70 .close = virtual_nci_close,
71 .send = virtual_nci_send
72};
73
74static ssize_t virtual_ncidev_read(struct file *file, char __user *buf,
75 size_t count, loff_t *ppos)
76{
77 size_t actual_len;
78
79 mutex_lock(&nci_mutex);
80 if (!send_buff) {
81 mutex_unlock(&nci_mutex);
82 return 0;
83 }
84
85 actual_len = min_t(size_t, count, send_buff->len);
86
87 if (copy_to_user(buf, send_buff->data, actual_len)) {
88 mutex_unlock(&nci_mutex);
89 return -EFAULT;
90 }
91
92 skb_pull(send_buff, actual_len);
93 if (send_buff->len == 0) {
94 consume_skb(send_buff);
95 send_buff = NULL;
96 }
97 mutex_unlock(&nci_mutex);
98
99 return actual_len;
100}
101
102static ssize_t virtual_ncidev_write(struct file *file,
103 const char __user *buf,
104 size_t count, loff_t *ppos)
105{
106 struct sk_buff *skb;
107
108 skb = alloc_skb(count, GFP_KERNEL);
109 if (!skb)
110 return -ENOMEM;
111
112 if (copy_from_user(skb_put(skb, count), buf, count)) {
113 kfree_skb(skb);
114 return -EFAULT;
115 }
116
117 nci_recv_frame(ndev, skb);
118 return count;
119}
120
121static int virtual_ncidev_open(struct inode *inode, struct file *file)
122{
123 int ret = 0;
124
125 mutex_lock(&nci_mutex);
126 if (state != virtual_ncidev_disabled) {
127 mutex_unlock(&nci_mutex);
128 return -EBUSY;
129 }
130
131 ndev = nci_allocate_device(&virtual_nci_ops, VIRTUAL_NFC_PROTOCOLS,
132 0, 0);
133 if (!ndev) {
134 mutex_unlock(&nci_mutex);
135 return -ENOMEM;
136 }
137
138 ret = nci_register_device(ndev);
139 if (ret < 0) {
140 nci_free_device(ndev);
141 mutex_unlock(&nci_mutex);
142 return ret;
143 }
144 state = virtual_ncidev_enabled;
145 mutex_unlock(&nci_mutex);
146
147 return 0;
148}
149
150static int virtual_ncidev_close(struct inode *inode, struct file *file)
151{
152 mutex_lock(&nci_mutex);
153
154 if (state == virtual_ncidev_enabled) {
155 state = virtual_ncidev_disabling;
156 mutex_unlock(&nci_mutex);
157
158 nci_unregister_device(ndev);
159 nci_free_device(ndev);
160
161 mutex_lock(&nci_mutex);
162 }
163
164 state = virtual_ncidev_disabled;
165 mutex_unlock(&nci_mutex);
166
167 return 0;
168}
169
170static long virtual_ncidev_ioctl(struct file *flip, unsigned int cmd,
171 unsigned long arg)
172{
173 struct nfc_dev *nfc_dev = ndev->nfc_dev;
174 void __user *p = (void __user *)arg;
175
176 if (cmd != IOCTL_GET_NCIDEV_IDX)
177 return -ENOTTY;
178
179 if (copy_to_user(p, &nfc_dev->idx, sizeof(nfc_dev->idx)))
180 return -EFAULT;
181
182 return 0;
183}
184
185static const struct file_operations virtual_ncidev_fops = {
186 .owner = THIS_MODULE,
187 .read = virtual_ncidev_read,
188 .write = virtual_ncidev_write,
189 .open = virtual_ncidev_open,
190 .release = virtual_ncidev_close,
191 .unlocked_ioctl = virtual_ncidev_ioctl
192};
193
194static int __init virtual_ncidev_init(void)
195{
196 state = virtual_ncidev_disabled;
197 miscdev.minor = MISC_DYNAMIC_MINOR;
198 miscdev.name = "virtual_nci";
199 miscdev.fops = &virtual_ncidev_fops;
200 miscdev.mode = S_IALLUGO;
201
202 return misc_register(&miscdev);
203}
204
205static void __exit virtual_ncidev_exit(void)
206{
207 misc_deregister(&miscdev);
208}
209
210module_init(virtual_ncidev_init);
211module_exit(virtual_ncidev_exit);
212
213MODULE_LICENSE("GPL");
214MODULE_DESCRIPTION("Virtual NCI device simulation driver");
215MODULE_AUTHOR("Bongsu Jeon <bongsu.jeon@samsung.com>");