Loading...
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 bool running;
30};
31
32static int virtual_nci_open(struct nci_dev *ndev)
33{
34 struct virtual_nci_dev *vdev = nci_get_drvdata(ndev);
35
36 vdev->running = true;
37 return 0;
38}
39
40static int virtual_nci_close(struct nci_dev *ndev)
41{
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;
47 vdev->running = false;
48 mutex_unlock(&vdev->mtx);
49
50 return 0;
51}
52
53static int virtual_nci_send(struct nci_dev *ndev, struct sk_buff *skb)
54{
55 struct virtual_nci_dev *vdev = nci_get_drvdata(ndev);
56
57 mutex_lock(&vdev->mtx);
58 if (vdev->send_buff || !vdev->running) {
59 mutex_unlock(&vdev->mtx);
60 kfree_skb(skb);
61 return -1;
62 }
63 vdev->send_buff = skb_copy(skb, GFP_KERNEL);
64 if (!vdev->send_buff) {
65 mutex_unlock(&vdev->mtx);
66 kfree_skb(skb);
67 return -1;
68 }
69 mutex_unlock(&vdev->mtx);
70 wake_up_interruptible(&vdev->wq);
71 consume_skb(skb);
72
73 return 0;
74}
75
76static const struct nci_ops virtual_nci_ops = {
77 .open = virtual_nci_open,
78 .close = virtual_nci_close,
79 .send = virtual_nci_send
80};
81
82static ssize_t virtual_ncidev_read(struct file *file, char __user *buf,
83 size_t count, loff_t *ppos)
84{
85 struct virtual_nci_dev *vdev = file->private_data;
86 size_t actual_len;
87
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))
92 return -EFAULT;
93 mutex_lock(&vdev->mtx);
94 }
95
96 actual_len = min_t(size_t, count, vdev->send_buff->len);
97
98 if (copy_to_user(buf, vdev->send_buff->data, actual_len)) {
99 mutex_unlock(&vdev->mtx);
100 return -EFAULT;
101 }
102
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;
107 }
108 mutex_unlock(&vdev->mtx);
109
110 return actual_len;
111}
112
113static ssize_t virtual_ncidev_write(struct file *file,
114 const char __user *buf,
115 size_t count, loff_t *ppos)
116{
117 struct virtual_nci_dev *vdev = file->private_data;
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
129 nci_recv_frame(vdev->ndev, skb);
130 return count;
131}
132
133static int virtual_ncidev_open(struct inode *inode, struct file *file)
134{
135 int ret = 0;
136 struct virtual_nci_dev *vdev;
137
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);
145 return -ENOMEM;
146 }
147
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);
154 if (ret < 0) {
155 nci_free_device(vdev->ndev);
156 mutex_destroy(&vdev->mtx);
157 kfree(vdev);
158 return ret;
159 }
160
161 return 0;
162}
163
164static int virtual_ncidev_close(struct inode *inode, struct file *file)
165{
166 struct virtual_nci_dev *vdev = file->private_data;
167
168 nci_unregister_device(vdev->ndev);
169 nci_free_device(vdev->ndev);
170 mutex_destroy(&vdev->mtx);
171 kfree(vdev);
172
173 return 0;
174}
175
176static long virtual_ncidev_ioctl(struct file *file, unsigned int cmd,
177 unsigned long arg)
178{
179 struct virtual_nci_dev *vdev = file->private_data;
180 const struct nfc_dev *nfc_dev = vdev->ndev->nfc_dev;
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
192static 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
201static struct miscdevice miscdev = {
202 .minor = MISC_DYNAMIC_MINOR,
203 .name = "virtual_nci",
204 .fops = &virtual_ncidev_fops,
205 .mode = 0600,
206};
207
208module_misc_device(miscdev);
209
210MODULE_LICENSE("GPL");
211MODULE_DESCRIPTION("Virtual NCI device simulation driver");
212MODULE_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>");