[net-next] nfc: Add a virtual nci device driver
diff mbox series

Message ID 20201228094507.32141-1-bongsu.jeon@samsung.com
State New, archived
Headers show
Series
  • [net-next] nfc: Add a virtual nci device driver
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Commit Message

Bongsu Jeon Dec. 28, 2020, 9:45 a.m. UTC
From: Bongsu Jeon <bongsu.jeon@samsung.com>

A NCI virtual device can be made to simulate a NCI device in user space.
Using the virtual NCI device, The NCI module and application can be
validated. This driver supports to communicate between the virtual NCI
device and NCI module.

Signed-off-by: Bongsu Jeon <bongsu.jeon@samsung.com>
---
 MAINTAINERS                  |   7 ++
 drivers/nfc/Kconfig          |  11 ++
 drivers/nfc/Makefile         |   1 +
 drivers/nfc/virtual_ncidev.c | 216 +++++++++++++++++++++++++++++++++++
 4 files changed, 235 insertions(+)
 create mode 100644 drivers/nfc/virtual_ncidev.c

Comments

Jakub Kicinski Dec. 28, 2020, 9:16 p.m. UTC | #1
On Mon, 28 Dec 2020 18:45:07 +0900 Bongsu Jeon wrote:
> From: Bongsu Jeon <bongsu.jeon@samsung.com>
> 
> A NCI virtual device can be made to simulate a NCI device in user space.
> Using the virtual NCI device, The NCI module and application can be
> validated. This driver supports to communicate between the virtual NCI
> device and NCI module.
> 
> Signed-off-by: Bongsu Jeon <bongsu.jeon@samsung.com>

net-next is still closed:

http://vger.kernel.org/~davem/net-next.html

Please repost in a few days.

As far as the patch goes - please include some tests for the NCI/NFC
subsystem based on this virtual device, best if they live in tree under
tools/testing/selftest.
Bongsu Jeon Dec. 31, 2020, 5:22 a.m. UTC | #2
On Tue, Dec 29, 2020 at 6:16 AM Jakub Kicinski <kuba@kernel.org> wrote:
>
> On Mon, 28 Dec 2020 18:45:07 +0900 Bongsu Jeon wrote:
> > From: Bongsu Jeon <bongsu.jeon@samsung.com>
> >
> > A NCI virtual device can be made to simulate a NCI device in user space.
> > Using the virtual NCI device, The NCI module and application can be
> > validated. This driver supports to communicate between the virtual NCI
> > device and NCI module.
> >
> > Signed-off-by: Bongsu Jeon <bongsu.jeon@samsung.com>
>
> net-next is still closed:
>
> http://vger.kernel.org/~davem/net-next.html
>
> Please repost in a few days.
>
> As far as the patch goes - please include some tests for the NCI/NFC
> subsystem based on this virtual device, best if they live in tree under
> tools/testing/selftest.

thank you for your answer.
I think that neard(NFC deamon) is necessary to test the NCI subsystem
meaningfully.
The NCI virtual device in user space can communicate with neard
through this driver.
Is it enough to make NCI virtual device at tools/nfc for some test?
Jakub Kicinski Jan. 4, 2021, 7:48 p.m. UTC | #3
On Thu, 31 Dec 2020 14:22:45 +0900 Bongsu Jeon wrote:
> On Tue, Dec 29, 2020 at 6:16 AM Jakub Kicinski <kuba@kernel.org> wrote:
> >
> > On Mon, 28 Dec 2020 18:45:07 +0900 Bongsu Jeon wrote:  
> > > From: Bongsu Jeon <bongsu.jeon@samsung.com>
> > >
> > > A NCI virtual device can be made to simulate a NCI device in user space.
> > > Using the virtual NCI device, The NCI module and application can be
> > > validated. This driver supports to communicate between the virtual NCI
> > > device and NCI module.
> > >
> > > Signed-off-by: Bongsu Jeon <bongsu.jeon@samsung.com>  
> >
> > net-next is still closed:
> >
> > http://vger.kernel.org/~davem/net-next.html
> >
> > Please repost in a few days.
> >
> > As far as the patch goes - please include some tests for the NCI/NFC
> > subsystem based on this virtual device, best if they live in tree under
> > tools/testing/selftest.  
> 
> thank you for your answer.
> I think that neard(NFC deamon) is necessary to test the NCI subsystem
> meaningfully.
> The NCI virtual device in user space can communicate with neard
> through this driver.
> Is it enough to make NCI virtual device at tools/nfc for some test?

I'm not sure if I understand. Are you asking if it's okay for the test
or have a dependency on neard?
Bongsu Jeon Jan. 5, 2021, 11:16 p.m. UTC | #4
On Tue, Jan 5, 2021 at 4:48 AM Jakub Kicinski <kuba@kernel.org> wrote:
>
> On Thu, 31 Dec 2020 14:22:45 +0900 Bongsu Jeon wrote:
> > On Tue, Dec 29, 2020 at 6:16 AM Jakub Kicinski <kuba@kernel.org> wrote:
> > >
> > > On Mon, 28 Dec 2020 18:45:07 +0900 Bongsu Jeon wrote:
> > > > From: Bongsu Jeon <bongsu.jeon@samsung.com>
> > > >
> > > > A NCI virtual device can be made to simulate a NCI device in user space.
> > > > Using the virtual NCI device, The NCI module and application can be
> > > > validated. This driver supports to communicate between the virtual NCI
> > > > device and NCI module.
> > > >
> > > > Signed-off-by: Bongsu Jeon <bongsu.jeon@samsung.com>
> > >
> > > net-next is still closed:
> > >
> > > http://vger.kernel.org/~davem/net-next.html
> > >
> > > Please repost in a few days.
> > >
> > > As far as the patch goes - please include some tests for the NCI/NFC
> > > subsystem based on this virtual device, best if they live in tree under
> > > tools/testing/selftest.
> >
> > thank you for your answer.
> > I think that neard(NFC deamon) is necessary to test the NCI subsystem
> > meaningfully.
> > The NCI virtual device in user space can communicate with neard
> > through this driver.
> > Is it enough to make NCI virtual device at tools/nfc for some test?
>
> I'm not sure if I understand. Are you asking if it's okay for the test
> or have a dependency on neard?

Sorry for confusing you.
There is no dependency between neard and a NCI virtual device.
But, To test the NCI module, it is necessary to make an application like neard.
Is it okay to just make a NCI virtual device as a tool at tools/nfc
without the application?
Jakub Kicinski Jan. 6, 2021, 5:01 p.m. UTC | #5
On Wed, 6 Jan 2021 08:16:47 +0900 Bongsu Jeon wrote:
> On Tue, Jan 5, 2021 at 4:48 AM Jakub Kicinski <kuba@kernel.org> wrote:
> > > thank you for your answer.
> > > I think that neard(NFC deamon) is necessary to test the NCI subsystem
> > > meaningfully.
> > > The NCI virtual device in user space can communicate with neard
> > > through this driver.
> > > Is it enough to make NCI virtual device at tools/nfc for some test?  
> >
> > I'm not sure if I understand. Are you asking if it's okay for the test
> > or have a dependency on neard?  
> 
> Sorry for confusing you.
> There is no dependency between neard and a NCI virtual device.
> But, To test the NCI module, it is necessary to make an application like neard.
> Is it okay to just make a NCI virtual device as a tool at tools/nfc
> without the application?

Meaning the device will be created but there will be no test cases in
the tree?

What we'd like to see is some form of a test which would exercise the
NFC-related kernel code on such a device and can signal success /
failure. It doesn't have to be very complex.

You can build a more complex user space applications and tests
separately.
Bongsu Jeon Jan. 7, 2021, 10:38 p.m. UTC | #6
On Thu, Jan 7, 2021 at 2:01 AM Jakub Kicinski <kuba@kernel.org> wrote:
>
> On Wed, 6 Jan 2021 08:16:47 +0900 Bongsu Jeon wrote:
> > On Tue, Jan 5, 2021 at 4:48 AM Jakub Kicinski <kuba@kernel.org> wrote:
> > > > thank you for your answer.
> > > > I think that neard(NFC deamon) is necessary to test the NCI subsystem
> > > > meaningfully.
> > > > The NCI virtual device in user space can communicate with neard
> > > > through this driver.
> > > > Is it enough to make NCI virtual device at tools/nfc for some test?
> > >
> > > I'm not sure if I understand. Are you asking if it's okay for the test
> > > or have a dependency on neard?
> >
> > Sorry for confusing you.
> > There is no dependency between neard and a NCI virtual device.
> > But, To test the NCI module, it is necessary to make an application like neard.
> > Is it okay to just make a NCI virtual device as a tool at tools/nfc
> > without the application?
>
> Meaning the device will be created but there will be no test cases in
> the tree?

yes.

>
> What we'd like to see is some form of a test which would exercise the
> NFC-related kernel code on such a device and can signal success /
> failure. It doesn't have to be very complex.
>
> You can build a more complex user space applications and tests
> separately.

okay. I understand it. I will try to make it.

Patch
diff mbox series

diff --git a/MAINTAINERS b/MAINTAINERS
index a355db292486..6479a4754a1e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12431,6 +12431,13 @@  F:	include/net/nfc/
 F:	include/uapi/linux/nfc.h
 F:	net/nfc/
 
+NFC VIRTUAL NCI DEVICE DRIVER
+M:	Bongsu Jeon <bongsu.jeon@samsung.com>
+L:	netdev@vger.kernel.org
+L:	linux-nfc@lists.01.org (moderated for non-subscribers)
+S:	Supported
+F:	drivers/nfc/virtual_ncidev.c
+
 NFS, SUNRPC, AND LOCKD CLIENTS
 M:	Trond Myklebust <trond.myklebust@hammerspace.com>
 M:	Anna Schumaker <anna.schumaker@netapp.com>
diff --git a/drivers/nfc/Kconfig b/drivers/nfc/Kconfig
index 75c65d339018..d32c3a8937ed 100644
--- a/drivers/nfc/Kconfig
+++ b/drivers/nfc/Kconfig
@@ -49,6 +49,17 @@  config NFC_PORT100
 
 	  If unsure, say N.
 
+config NFC_VIRTUAL_NCI
+	tristate "NCI device simulator driver"
+	depends on NFC_NCI
+	help
+	  A NCI virtual device can be made to simulate a NCI device in user
+	  level. Using the virtual NCI device, The NCI module and application
+	  can be validated. This driver supports to communicate between the
+	  virtual NCI device and NCI module.
+
+	  If unsure, say N.
+
 source "drivers/nfc/fdp/Kconfig"
 source "drivers/nfc/pn544/Kconfig"
 source "drivers/nfc/pn533/Kconfig"
diff --git a/drivers/nfc/Makefile b/drivers/nfc/Makefile
index 5393ba59b17d..7b1bfde1d971 100644
--- a/drivers/nfc/Makefile
+++ b/drivers/nfc/Makefile
@@ -17,3 +17,4 @@  obj-$(CONFIG_NFC_ST_NCI)	+= st-nci/
 obj-$(CONFIG_NFC_NXP_NCI)	+= nxp-nci/
 obj-$(CONFIG_NFC_S3FWRN5)	+= s3fwrn5/
 obj-$(CONFIG_NFC_ST95HF)	+= st95hf/
+obj-$(CONFIG_NFC_VIRTUAL_NCI)	+= virtual_ncidev.o
diff --git a/drivers/nfc/virtual_ncidev.c b/drivers/nfc/virtual_ncidev.c
new file mode 100644
index 000000000000..163d0b2dda2e
--- /dev/null
+++ b/drivers/nfc/virtual_ncidev.c
@@ -0,0 +1,216 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Virtual NCI device simulation driver
+ *
+ * Copyright (C) 2020 Samsung Electrnoics
+ * Bongsu Jeon <bongsu.jeon@samsung.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/miscdevice.h>
+#include <linux/mutex.h>
+#include <net/nfc/nci_core.h>
+
+enum virtual_ncidev_mode {
+	virtual_ncidev_enabled,
+	virtual_ncidev_disabled,
+	virtual_ncidev_disabling,
+};
+
+#define VIRTUAL_NFC_PROTOCOLS	(NFC_PROTO_JEWEL_MASK | \
+				 NFC_PROTO_MIFARE_MASK | \
+				 NFC_PROTO_FELICA_MASK | \
+				 NFC_PROTO_ISO14443_MASK | \
+				 NFC_PROTO_ISO14443_B_MASK | \
+				 NFC_PROTO_ISO15693_MASK)
+
+static enum virtual_ncidev_mode state;
+static struct mutex nci_send_mutex;
+static struct miscdevice miscdev;
+static struct sk_buff *send_buff;
+static struct mutex nci_mutex;
+static struct nci_dev *ndev;
+static bool full_txbuff;
+
+static bool virtual_ncidev_check_enabled(void)
+{
+	bool ret = true;
+
+	mutex_lock(&nci_mutex);
+	if (state != virtual_ncidev_enabled)
+		ret = false;
+	mutex_unlock(&nci_mutex);
+
+	return ret;
+}
+
+static int virtual_nci_open(struct nci_dev *ndev)
+{
+	return 0;
+}
+
+static int virtual_nci_close(struct nci_dev *ndev)
+{
+	mutex_lock(&nci_send_mutex);
+	if (full_txbuff)
+		kfree_skb(send_buff);
+	full_txbuff = false;
+	mutex_unlock(&nci_send_mutex);
+
+	return 0;
+}
+
+static int virtual_nci_send(struct nci_dev *ndev, struct sk_buff *skb)
+{
+	if (virtual_ncidev_check_enabled() == false)
+		return 0;
+
+	mutex_lock(&nci_send_mutex);
+	if (full_txbuff) {
+		mutex_unlock(&nci_send_mutex);
+		return -1;
+	}
+	send_buff = skb_copy(skb, GFP_KERNEL);
+	full_txbuff = true;
+	mutex_unlock(&nci_send_mutex);
+
+	return 0;
+}
+
+static struct nci_ops virtual_nci_ops = {
+	.open = virtual_nci_open,
+	.close = virtual_nci_close,
+	.send = virtual_nci_send
+};
+
+static ssize_t virtual_ncidev_read(struct file *file, char __user *buf,
+				   size_t count, loff_t *ppos)
+{
+	size_t actual_len;
+
+	mutex_lock(&nci_send_mutex);
+	if (!full_txbuff) {
+		mutex_unlock(&nci_send_mutex);
+		return 0;
+	}
+
+	actual_len = count > send_buff->len ? send_buff->len : count;
+
+	if (copy_to_user(buf, send_buff->data, actual_len)) {
+		mutex_unlock(&nci_send_mutex);
+		return -EFAULT;
+	}
+
+	skb_pull(send_buff, actual_len);
+	if (send_buff->len == 0) {
+		kfree_skb(send_buff);
+		full_txbuff = false;
+	}
+	mutex_unlock(&nci_send_mutex);
+
+	return actual_len;
+}
+
+static ssize_t virtual_ncidev_write(struct file *file,
+				    const char __user *buf,
+				    size_t count, loff_t *ppos)
+{
+	struct sk_buff *skb;
+
+	skb = alloc_skb(count, GFP_KERNEL);
+	if (!skb)
+		return -ENOMEM;
+
+	if (copy_from_user(skb_put(skb, count), buf, count))
+		return -EFAULT;
+
+	nci_recv_frame(ndev, skb);
+
+	return count;
+}
+
+static int virtual_ncidev_open(struct inode *inode, struct file *file)
+{
+	int ret = 0;
+
+	mutex_lock(&nci_mutex);
+	if (state != virtual_ncidev_disabled) {
+		mutex_unlock(&nci_mutex);
+		return -EBUSY;
+	}
+
+	mutex_init(&nci_send_mutex);
+
+	ndev = nci_allocate_device(&virtual_nci_ops, VIRTUAL_NFC_PROTOCOLS,
+				   0, 0);
+	if (!ndev) {
+		mutex_unlock(&nci_mutex);
+		return -ENOMEM;
+	}
+
+	ret = nci_register_device(ndev);
+	if (ret < 0) {
+		nci_free_device(ndev);
+		mutex_unlock(&nci_mutex);
+		return ret;
+	}
+	state = virtual_ncidev_enabled;
+	mutex_unlock(&nci_mutex);
+
+	return 0;
+}
+
+static int virtual_ncidev_close(struct inode *inode, struct file *file)
+{
+	mutex_lock(&nci_mutex);
+
+	if (state == virtual_ncidev_enabled) {
+		state = virtual_ncidev_disabling;
+		mutex_unlock(&nci_mutex);
+
+		nci_unregister_device(ndev);
+		nci_free_device(ndev);
+
+		mutex_lock(&nci_mutex);
+	}
+
+	state = virtual_ncidev_disabled;
+	mutex_unlock(&nci_mutex);
+
+	return 0;
+}
+
+static const struct file_operations virtual_ncidev_fops = {
+	.owner = THIS_MODULE,
+	.read = virtual_ncidev_read,
+	.write = virtual_ncidev_write,
+	.open = virtual_ncidev_open,
+	.release = virtual_ncidev_close,
+};
+
+static int __init virtual_ncidev_init(void)
+{
+	int ret;
+
+	mutex_init(&nci_mutex);
+	state = virtual_ncidev_disabled;
+	miscdev.minor = MISC_DYNAMIC_MINOR;
+	miscdev.name = "virtual_nci";
+	miscdev.fops = &virtual_ncidev_fops;
+	ret = misc_register(&miscdev);
+
+	return ret;
+}
+
+static void __exit virtual_ncidev_exit(void)
+{
+	misc_deregister(&miscdev);
+}
+
+module_init(virtual_ncidev_init);
+module_exit(virtual_ncidev_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Virtual NCI device simulation driver");
+MODULE_AUTHOR("Bongsu Jeon <bongsu.jeon@samsung.com>");