[PATCH] net: cdc_ncm: Export cdc_ncm_{tx,rx}_fixup functions for re-use

[PATCH] net: cdc_ncm: Export cdc_ncm_{tx,rx}_fixup functions for re-use

[Enrico Mioso]

Some drivers implementing NCM-like protocols, may re-use those functions, as is 
the case in the huawei_cdc_ncm driver.
Export them via EXPORT_SYMBOL_GPL.

Signed-off-by: Enrico Mioso <mrkiko.rs@gmail.com>
---

 drivers/net/usb/cdc_ncm.c   |    6 ++++--
 include/linux/usb/cdc_ncm.h |    3 +++
 2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
index 43afde8..62686be 100644
--- a/drivers/net/usb/cdc_ncm.c
+++ b/drivers/net/usb/cdc_ncm.c
@@ -858,7 +858,7 @@ static void cdc_ncm_txpath_bh(unsigned long param)
 	}
 }
 
-static struct sk_buff *
+struct sk_buff *
 cdc_ncm_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
 {
 	struct sk_buff *skb_out;
@@ -885,6 +885,7 @@ error:
 
 	return NULL;
 }
+EXPORT_SYMBOL_GPL(cdc_ncm_tx_fixup);
 
 /* verify NTB header and return offset of first NDP, or negative error */
 int cdc_ncm_rx_verify_nth16(struct cdc_ncm_ctx *ctx, struct sk_buff *skb_in)
@@ -965,7 +966,7 @@ error:
 }
 EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_ndp16);
 
-static int cdc_ncm_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in)
+int cdc_ncm_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in)
 {
 	struct sk_buff *skb;
 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
@@ -1040,6 +1041,7 @@ err_ndp:
 error:
 	return 0;
 }
+EXPORT_SYMBOL_GPL(cdc_ncm_rx_fixup);
 
 static void
 cdc_ncm_speed_change(struct cdc_ncm_ctx *ctx,
diff --git a/include/linux/usb/cdc_ncm.h b/include/linux/usb/cdc_ncm.h
index cc25b70..163244b 100644
--- a/include/linux/usb/cdc_ncm.h
+++ b/include/linux/usb/cdc_ncm.h
@@ -133,3 +133,6 @@ extern void cdc_ncm_unbind(struct usbnet *dev, struct usb_interface *intf);
 extern struct sk_buff *cdc_ncm_fill_tx_frame(struct cdc_ncm_ctx *ctx, struct sk_buff *skb, __le32 sign);
 extern int cdc_ncm_rx_verify_nth16(struct cdc_ncm_ctx *ctx, struct sk_buff *skb_in);
 extern int cdc_ncm_rx_verify_ndp16(struct sk_buff *skb_in, int ndpoffset);
+struct sk_buff *
+cdc_ncm_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags);
+int cdc_ncm_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in);

[PATCH] net: huawei_cdc_ncm: Introduce new huawei_cdc_ncm driver

[Enrico Mioso]

This driver supports devices using the NCM protocol as an encapsulation layer
for other protocols, like the E3131 Huawei 3G modem.

Suggested-by: Bjorn Mork <bjorn@mork.no>
Signed-off-by: Enrico Mioso <mrkiko.rs@gmail.com>
---

 drivers/net/usb/Kconfig          |   11 ++
 drivers/net/usb/Makefile         |    1 +
 drivers/net/usb/huawei_cdc_ncm.c |  210 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 222 insertions(+)
 create mode 100644 drivers/net/usb/huawei_cdc_ncm.c
diff --git a/drivers/net/usb/Kconfig b/drivers/net/usb/Kconfig
index d84bfd4..6e56751 100644
--- a/drivers/net/usb/Kconfig
+++ b/drivers/net/usb/Kconfig
@@ -242,6 +242,17 @@ config USB_NET_CDC_NCM
 	    * ST-Ericsson M343 HSPA Mobile Broadband Modem (reference design)
 	    * Ericsson F5521gw Mobile Broadband Module
 
+config USB_NET_HUAWEI_CDC_NCM
+	tristate "Huawei-style CDC NCM support"
+	depends on USB_USBNET
+	select USB_WDM
+	select USB_NET_CDC_NCM
+	help
+		This driver aims to support huawei-style NCM devices, that use ncm as a
+		transport for other protocols.
+		To compile this driver as a module, choose M here: the module will be
+		called huawei_cdc_ncm.
+
 config USB_NET_CDC_MBIM
 	tristate "CDC MBIM support"
 	depends on USB_USBNET
diff --git a/drivers/net/usb/Makefile b/drivers/net/usb/Makefile
index e817178..fd0e6a7 100644
--- a/drivers/net/usb/Makefile
+++ b/drivers/net/usb/Makefile
@@ -31,6 +31,7 @@ obj-$(CONFIG_USB_IPHETH)	+= ipheth.o
 obj-$(CONFIG_USB_SIERRA_NET)	+= sierra_net.o
 obj-$(CONFIG_USB_NET_CX82310_ETH)	+= cx82310_eth.o
 obj-$(CONFIG_USB_NET_CDC_NCM)	+= cdc_ncm.o
+obj-$(CONFIG_USB_NET_HUAWEI_CDC_NCM)	+= huawei_cdc_ncm.o
 obj-$(CONFIG_USB_VL600)		+= lg-vl600.o
 obj-$(CONFIG_USB_NET_QMI_WWAN)	+= qmi_wwan.o
 obj-$(CONFIG_USB_NET_CDC_MBIM)	+= cdc_mbim.o
diff --git a/drivers/net/usb/huawei_cdc_ncm.c b/drivers/net/usb/huawei_cdc_ncm.c
new file mode 100644
index 0000000..d3426b9
--- /dev/null
+++ b/drivers/net/usb/huawei_cdc_ncm.c
@@ -0,0 +1,210 @@
+/*
+ * huawei_cdc_ncm.c - handles huawei-style NCM devices.
+ * Copyright (C) 2013	 Enrico Mioso <mrkiko.rs@gmail.com>
+ * This driver handles devices resembling the CDC NCM standard, but
+ * encapsulating another protocol inside it. An example are some Huawei 3G
+ * devices, exposing an embedded AT channel where you can set up the NCM
+ * connection.
+ * This code has been heavily inspired by the cdc_mbim.c driver, which is
+ * Copyright (c) 2012  Smith Micro Software, Inc.
+ * Copyright (c) 2012  Bj??rn Mork <bjorn@mork.no>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/ethtool.h>
+#include <linux/if_vlan.h>
+#include <linux/ip.h>
+#include <linux/mii.h>
+#include <linux/usb.h>
+#include <linux/usb/cdc.h>
+#include <linux/usb/usbnet.h>
+#include <linux/usb/cdc-wdm.h>
+#include <linux/usb/cdc_ncm.h>
+
+/* Driver data */
+struct huawei_cdc_ncm_state {
+	struct cdc_ncm_ctx *ctx;
+	atomic_t pmcount;
+	struct usb_driver *subdriver;
+	struct usb_interface *control;
+	struct usb_interface *data;
+};
+
+static int huawei_cdc_ncm_manage_power(struct usbnet *usbnet_dev, int on)
+{
+	struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data;
+	int rv = 0;
+
+	if ((on && atomic_add_return(1, &drvstate->pmcount) == 1) || (!on && atomic_dec_and_test(&drvstate->pmcount))) {
+		rv = usb_autopm_get_interface(usbnet_dev->intf);
+		if (rv < 0)
+			goto err;
+		usbnet_dev->intf->needs_remote_wakeup = on;
+		usb_autopm_put_interface(usbnet_dev->intf);
+	}
+err:
+	return rv;
+}
+
+static int huawei_cdc_ncm_wdm_manage_power(struct usb_interface *intf, int status)
+{
+	struct usbnet *usbnet_dev = usb_get_intfdata(intf);
+
+	/* can be called while disconnecting */
+	if (!usbnet_dev)
+		return 0;
+
+	return huawei_cdc_ncm_manage_power(usbnet_dev, status);
+}
+
+
+static int huawei_cdc_ncm_bind(struct usbnet *usbnet_dev, struct usb_interface *intf)
+{
+	struct cdc_ncm_ctx *ctx;
+	struct usb_driver *subdriver = ERR_PTR(-ENODEV);
+	int ret = -ENODEV;
+	struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data;
+
+	ret = cdc_ncm_bind_common(usbnet_dev, intf, 1); /* altsetting should be 1 for NCM devices */
+	if (ret)
+		goto err;
+
+	ctx = drvstate->ctx;
+
+	if (usbnet_dev->status)
+		subdriver = usb_cdc_wdm_register(ctx->control,
+						 &usbnet_dev->status->desc,
+						 256, /* CDC-WMC r1.1 requires wMaxCommand to be "at least 256 decimal (0x100)" */
+						 huawei_cdc_ncm_wdm_manage_power);
+	if (IS_ERR(subdriver)) {
+		ret = PTR_ERR(subdriver);
+		cdc_ncm_unbind(usbnet_dev, intf);
+		goto err;
+	}
+
+	/* Prevent usbnet from using the status descriptor */
+	usbnet_dev->status = NULL;
+
+	drvstate->subdriver = subdriver;
+
+err:
+	return ret;
+}
+
+static void huawei_cdc_ncm_unbind(struct usbnet *usbnet_dev, struct usb_interface *intf)
+{
+	struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data;
+	struct cdc_ncm_ctx *ctx = drvstate->ctx;
+
+	if (drvstate->subdriver && drvstate->subdriver->disconnect)
+		drvstate->subdriver->disconnect(ctx->control);
+	drvstate->subdriver = NULL;
+
+	cdc_ncm_unbind(usbnet_dev, intf);
+}
+
+static int huawei_cdc_ncm_suspend(struct usb_interface *intf, pm_message_t message)
+{
+	int ret = 0;
+	struct usbnet *usbnet_dev = usb_get_intfdata(intf);
+	struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data;
+	struct cdc_ncm_ctx *ctx = drvstate->ctx;
+
+	if (ctx == NULL) {
+		ret = -1;
+		goto error;
+	}
+
+	ret = usbnet_suspend(intf, message);
+	if (ret < 0)
+		goto error;
+
+	if (intf == ctx->control && drvstate->subdriver && drvstate->subdriver->suspend)
+		ret = drvstate->subdriver->suspend(intf, message);
+	if (ret < 0)
+		usbnet_resume(intf);
+
+error:
+	return ret;
+}
+
+static int huawei_cdc_ncm_resume(struct usb_interface *intf)
+{
+	int ret = 0;
+	struct usbnet *usbnet_dev = usb_get_intfdata(intf);
+	struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data;
+	struct cdc_ncm_ctx *ctx = drvstate->ctx;
+	bool callsub = (intf == ctx->control && drvstate->subdriver && drvstate->subdriver->resume); /* should we call subdriver's resume? ? */
+
+	if (callsub)
+		ret = drvstate->subdriver->resume(intf);
+	if (ret < 0)
+		goto err;
+	ret = usbnet_resume(intf);
+	if (ret < 0 && callsub && drvstate->subdriver->suspend)
+		drvstate->subdriver->suspend(intf, PMSG_SUSPEND);
+err:
+	return ret;
+}
+
+static int huawei_cdc_ncm_check_connect(struct usbnet *usbnet_dev)
+{
+	struct cdc_ncm_ctx *ctx;
+
+	ctx = (struct cdc_ncm_ctx *)usbnet_dev->data[0];
+
+	if (ctx == NULL)
+		return 1; /* disconnected */
+
+	return !ctx->connected;
+}
+
+static const struct driver_info huawei_cdc_ncm_info = {
+	.description = "Huawei CDC NCM device",
+	.flags = FLAG_NO_SETINT | FLAG_MULTI_PACKET | FLAG_WWAN,
+	.bind = huawei_cdc_ncm_bind,
+	.unbind = huawei_cdc_ncm_unbind,
+	.check_connect = huawei_cdc_ncm_check_connect,
+	.manage_power = huawei_cdc_ncm_manage_power,
+	.rx_fixup = cdc_ncm_rx_fixup,
+	.tx_fixup = cdc_ncm_tx_fixup,
+};
+
+static const struct usb_device_id huawei_cdc_ncm_devs[] = {
+	/* Huawei NCM devices disguised as vendor specific */
+	{ USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x02, 0x16),
+	  .driver_info = (unsigned long)&huawei_cdc_ncm_info,
+	},
+	{ USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x02, 0x46),
+	  .driver_info = (unsigned long)&huawei_cdc_ncm_info,
+	},
+	{ USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x02, 0x76),
+	  .driver_info = (unsigned long)&huawei_cdc_ncm_info,
+	},
+
+	/* Terminating entry */
+	{
+	},
+};
+MODULE_DEVICE_TABLE(usb, huawei_cdc_ncm_devs);
+
+static struct usb_driver huawei_cdc_ncm_driver = {
+	.name = "huawei_cdc_ncm",
+	.id_table = huawei_cdc_ncm_devs,
+	.probe = usbnet_probe,
+	.disconnect = usbnet_disconnect,
+	.suspend = huawei_cdc_ncm_suspend,
+	.resume = huawei_cdc_ncm_resume,
+	.reset_resume = huawei_cdc_ncm_resume,
+	.supports_autosuspend = 1,
+	.disable_hub_initiated_lpm = 1,
+};
+module_usb_driver(huawei_cdc_ncm_driver);
+MODULE_AUTHOR("Enrico Mioso <mrkiko.rs@gmail.com>");
+MODULE_DESCRIPTION("USB CDC NCM host driver with encapsulated protocol support");
+MODULE_LICENSE("GPL");

Re: [PATCH] net: cdc_ncm: Export cdc_ncm_{tx,rx}_fixup functions for re-use

[Greg Kroah-Hartman]

On Fri, Aug 16, 2013 at 03:39:19PM +0200, Enrico Mioso wrote:
> Some drivers implementing NCM-like protocols, may re-use those functions, as is 
> the case in the huawei_cdc_ncm driver.

Where is that driver at, I don't see it in the kernel tree.

> Export them via EXPORT_SYMBOL_GPL.

Normally we don't export symbols until code that actually uses the
symbols lands in the tree at the same time.

thanks,

greg k-h

Re: [PATCH] net: cdc_ncm: Export cdc_ncm_{tx,rx}_fixup functions for re-use

[Enrico Mioso]

Yes, you're right. I'm sorry - this time I didn't apply numbering scheme to 
those 3 patches - yet they are consequential, but not depending on each other 
from a strict point of view.

Thank you for your review Greg!


On Fri, 16 Aug 2013, Greg Kroah-Hartman wrote:

==Date: Fri, 16 Aug 2013 06:49:07 -0700
==From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
==To: Enrico Mioso <mrkiko.rs@gmail.com>
==Cc: Bj?rn Mork <bjorn@mork.no>, linux-kernel@vger.kernel.org,
==    linux-usb@vger.kernel.org, netdev@vger.kernel.org
==Subject: Re: [PATCH] net: cdc_ncm: Export cdc_ncm_{tx,
==    rx}_fixup functions for re-use
==
==On Fri, Aug 16, 2013 at 03:39:19PM +0200, Enrico Mioso wrote:
==> Some drivers implementing NCM-like protocols, may re-use those functions, as is 
==> the case in the huawei_cdc_ncm driver.
==
==Where is that driver at, I don't see it in the kernel tree.
==
==> Export them via EXPORT_SYMBOL_GPL.
==
==Normally we don't export symbols until code that actually uses the
==symbols lands in the tree at the same time.
==
==thanks,
==
==greg k-h
==

Re: [PATCH] net: cdc_ncm: Export cdc_ncm_{tx,rx}_fixup functions for re-use

[Greg Kroah-Hartman]

On Fri, Aug 16, 2013 at 06:49:07AM -0700, Greg Kroah-Hartman wrote:
> On Fri, Aug 16, 2013 at 03:39:19PM +0200, Enrico Mioso wrote:
> > Some drivers implementing NCM-like protocols, may re-use those functions, as is 
> > the case in the huawei_cdc_ncm driver.
> 
> Where is that driver at, I don't see it in the kernel tree.

And you sent it in a different email, sorry about that.

Normally you would number the patches (i.e. [1/3], and so on), so that
people know which order to apply them in, and that there really is 3
patches in the series...

thanks,

greg k-h