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215 lines
4.3 KiB
215 lines
4.3 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* Virtual NCI device simulation driver |
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* |
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* Copyright (C) 2020 Samsung Electrnoics |
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* Bongsu Jeon <[email protected]> |
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*/ |
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/miscdevice.h> |
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#include <linux/mutex.h> |
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#include <net/nfc/nci_core.h> |
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enum virtual_ncidev_mode { |
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virtual_ncidev_enabled, |
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virtual_ncidev_disabled, |
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virtual_ncidev_disabling, |
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}; |
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#define IOCTL_GET_NCIDEV_IDX 0 |
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#define VIRTUAL_NFC_PROTOCOLS (NFC_PROTO_JEWEL_MASK | \ |
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NFC_PROTO_MIFARE_MASK | \ |
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NFC_PROTO_FELICA_MASK | \ |
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NFC_PROTO_ISO14443_MASK | \ |
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NFC_PROTO_ISO14443_B_MASK | \ |
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NFC_PROTO_ISO15693_MASK) |
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static enum virtual_ncidev_mode state; |
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static struct miscdevice miscdev; |
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static struct sk_buff *send_buff; |
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static struct nci_dev *ndev; |
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static DEFINE_MUTEX(nci_mutex); |
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static int virtual_nci_open(struct nci_dev *ndev) |
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{ |
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return 0; |
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} |
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static int virtual_nci_close(struct nci_dev *ndev) |
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{ |
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mutex_lock(&nci_mutex); |
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kfree_skb(send_buff); |
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send_buff = NULL; |
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mutex_unlock(&nci_mutex); |
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return 0; |
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} |
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static int virtual_nci_send(struct nci_dev *ndev, struct sk_buff *skb) |
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{ |
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mutex_lock(&nci_mutex); |
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if (state != virtual_ncidev_enabled) { |
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mutex_unlock(&nci_mutex); |
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return 0; |
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} |
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if (send_buff) { |
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mutex_unlock(&nci_mutex); |
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return -1; |
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} |
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send_buff = skb_copy(skb, GFP_KERNEL); |
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mutex_unlock(&nci_mutex); |
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return 0; |
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} |
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static struct nci_ops virtual_nci_ops = { |
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.open = virtual_nci_open, |
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.close = virtual_nci_close, |
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.send = virtual_nci_send |
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}; |
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static ssize_t virtual_ncidev_read(struct file *file, char __user *buf, |
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size_t count, loff_t *ppos) |
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{ |
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size_t actual_len; |
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mutex_lock(&nci_mutex); |
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if (!send_buff) { |
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mutex_unlock(&nci_mutex); |
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return 0; |
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} |
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actual_len = min_t(size_t, count, send_buff->len); |
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if (copy_to_user(buf, send_buff->data, actual_len)) { |
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mutex_unlock(&nci_mutex); |
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return -EFAULT; |
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} |
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skb_pull(send_buff, actual_len); |
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if (send_buff->len == 0) { |
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consume_skb(send_buff); |
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send_buff = NULL; |
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} |
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mutex_unlock(&nci_mutex); |
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return actual_len; |
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} |
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static ssize_t virtual_ncidev_write(struct file *file, |
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const char __user *buf, |
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size_t count, loff_t *ppos) |
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{ |
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struct sk_buff *skb; |
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skb = alloc_skb(count, GFP_KERNEL); |
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if (!skb) |
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return -ENOMEM; |
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if (copy_from_user(skb_put(skb, count), buf, count)) { |
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kfree_skb(skb); |
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return -EFAULT; |
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} |
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nci_recv_frame(ndev, skb); |
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return count; |
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} |
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static int virtual_ncidev_open(struct inode *inode, struct file *file) |
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{ |
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int ret = 0; |
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mutex_lock(&nci_mutex); |
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if (state != virtual_ncidev_disabled) { |
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mutex_unlock(&nci_mutex); |
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return -EBUSY; |
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} |
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ndev = nci_allocate_device(&virtual_nci_ops, VIRTUAL_NFC_PROTOCOLS, |
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0, 0); |
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if (!ndev) { |
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mutex_unlock(&nci_mutex); |
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return -ENOMEM; |
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} |
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ret = nci_register_device(ndev); |
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if (ret < 0) { |
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nci_free_device(ndev); |
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mutex_unlock(&nci_mutex); |
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return ret; |
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} |
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state = virtual_ncidev_enabled; |
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mutex_unlock(&nci_mutex); |
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return 0; |
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} |
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static int virtual_ncidev_close(struct inode *inode, struct file *file) |
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{ |
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mutex_lock(&nci_mutex); |
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if (state == virtual_ncidev_enabled) { |
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state = virtual_ncidev_disabling; |
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mutex_unlock(&nci_mutex); |
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nci_unregister_device(ndev); |
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nci_free_device(ndev); |
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mutex_lock(&nci_mutex); |
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} |
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state = virtual_ncidev_disabled; |
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mutex_unlock(&nci_mutex); |
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return 0; |
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} |
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static long virtual_ncidev_ioctl(struct file *flip, unsigned int cmd, |
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unsigned long arg) |
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{ |
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struct nfc_dev *nfc_dev = ndev->nfc_dev; |
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void __user *p = (void __user *)arg; |
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if (cmd != IOCTL_GET_NCIDEV_IDX) |
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return -ENOTTY; |
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if (copy_to_user(p, &nfc_dev->idx, sizeof(nfc_dev->idx))) |
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return -EFAULT; |
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return 0; |
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} |
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static const struct file_operations virtual_ncidev_fops = { |
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.owner = THIS_MODULE, |
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.read = virtual_ncidev_read, |
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.write = virtual_ncidev_write, |
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.open = virtual_ncidev_open, |
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.release = virtual_ncidev_close, |
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.unlocked_ioctl = virtual_ncidev_ioctl |
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}; |
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static int __init virtual_ncidev_init(void) |
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{ |
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state = virtual_ncidev_disabled; |
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miscdev.minor = MISC_DYNAMIC_MINOR; |
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miscdev.name = "virtual_nci"; |
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miscdev.fops = &virtual_ncidev_fops; |
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miscdev.mode = S_IALLUGO; |
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return misc_register(&miscdev); |
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} |
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static void __exit virtual_ncidev_exit(void) |
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{ |
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misc_deregister(&miscdev); |
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} |
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module_init(virtual_ncidev_init); |
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module_exit(virtual_ncidev_exit); |
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MODULE_LICENSE("GPL"); |
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MODULE_DESCRIPTION("Virtual NCI device simulation driver"); |
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MODULE_AUTHOR("Bongsu Jeon <[email protected]>");
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