net/usb: add sierra_net.c driver

Re-submitted based on comments from netdev community.
Summary of the changes:
1. Improved error handling.
2. Added the missing timeout arguments to usb_control_msg().

The following is a new Linux driver which exposes certain models of Sierra
Wireless modems to the operating system as Network Interface Cards (NICs).

This driver requires a version of the sierra.c driver which supports
blacklisting to work properly. The blacklist in sierra.c rejects the interfaces
claimed by sierra_net.c. Likewise, the sierra_net.c driver only accepts
(i.e. whitelists) the interface(s) used for USB-to-WWAN traffic.
The version of sierra.c which supports blacklisting is
available from the sierra wireless knowledge base page for older kernels. It is
also available in Linux kernel starting from version 2.6.31.

This driver works with all Sierra Wireless devices configured with PID=68A3
like USB305, USB306 provided the corresponding firmware version is I2.0
(for USB305) or M3.0 (for USB306) and later.
This driver will not work with earlier firmware versions than the ones shown
above. In this case the driver will issue an error message indicating
incompatibility and will not serve the device's USB-to-WWAN interface.

Sierra_net.c sits atop a pre-existing Linux driver called usbnet.c.
A series of hook functions are provided in sierra_net.c which are called by
usbnet.c in response to a particular condition such as receipt or transmission
of a data packet. As such, usbnet.c does most of the work of making
a modem appear to the system as a network device and for properly exchanging
traffic between the USB subsystem and the Network card interface.
Sierra_net.c is concerned with managing the data exchanged between the
USB-to-WWAN interface and the upper layers of the operating system.

Signed-off-by: Elina Pasheva <epasheva@sierrawireless.com>
Signed-off-by: Rory Filer <rfiler@sierrawireless.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 1012 insertions, 0 deletions

diff --git a/drivers/net/usb/Kconfig b/drivers/net/usb/Kconfig
index 63be4caec70..5d58abc224f 100644
--- a/drivers/net/usb/Kconfig
+++ b/drivers/net/usb/Kconfig
@@ -397,4 +397,14 @@ config USB_IPHETH
 
 	  For more information: http://giagio.com/wiki/moin.cgi/iPhoneEthernetDriver
 
+config USB_SIERRA_NET
+	tristate "USB-to-WWAN Driver for Sierra Wireless modems"
+	depends on USB_USBNET
+	default y
+	help
+	  Choose this option if you have a Sierra Wireless USB-to-WWAN device.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called sierra_net.
+
 endmenu
diff --git a/drivers/net/usb/Makefile b/drivers/net/usb/Makefile
index edb09c0ddf8..b13a279663b 100644
--- a/drivers/net/usb/Makefile
+++ b/drivers/net/usb/Makefile
@@ -24,4 +24,5 @@ obj-$(CONFIG_USB_USBNET)	+= usbnet.o
 obj-$(CONFIG_USB_NET_INT51X1)	+= int51x1.o
 obj-$(CONFIG_USB_CDC_PHONET)	+= cdc-phonet.o
 obj-$(CONFIG_USB_IPHETH)	+= ipheth.o
+obj-$(CONFIG_USB_SIERRA_NET)	+= sierra_net.o
 
diff --git a/drivers/net/usb/sierra_net.c b/drivers/net/usb/sierra_net.c
new file mode 100644
index 00000000000..a44f9e0ea09
--- /dev/null
+++ b/drivers/net/usb/sierra_net.c
@@ -0,0 +1,1001 @@
+/*
+ * USB-to-WWAN Driver for Sierra Wireless modems
+ *
+ * Copyright (C) 2008, 2009, 2010 Paxton Smith, Matthew Safar, Rory Filer
+ *                          <linux@sierrawireless.com>
+ *
+ * Portions of this based on the cdc_ether driver by David Brownell (2003-2005)
+ * and Ole Andre Vadla Ravnas (ActiveSync) (2006).
+ *
+ * IMPORTANT DISCLAIMER: This driver is not commercially supported by
+ * Sierra Wireless. Use at your own risk.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#define DRIVER_VERSION "v.2.0"
+#define DRIVER_AUTHOR "Paxton Smith, Matthew Safar, Rory Filer"
+#define DRIVER_DESC "USB-to-WWAN Driver for Sierra Wireless modems"
+static const char driver_name[] = "sierra_net";
+
+/* if defined debug messages enabled */
+/*#define	DEBUG*/
+
+#include <linux/module.h>
+#include <linux/etherdevice.h>
+#include <linux/ethtool.h>
+#include <linux/mii.h>
+#include <linux/sched.h>
+#include <linux/timer.h>
+#include <linux/usb.h>
+#include <linux/usb/cdc.h>
+#include <net/ip.h>
+#include <net/udp.h>
+#include <asm/unaligned.h>
+#include <linux/usb/usbnet.h>
+
+#define SWI_USB_REQUEST_GET_FW_ATTR	0x06
+#define SWI_GET_FW_ATTR_MASK		0x08
+
+/* atomic counter partially included in MAC address to make sure 2 devices
+ * do not end up with the same MAC - concept breaks in case of > 255 ifaces
+ */
+static	atomic_t iface_counter = ATOMIC_INIT(0);
+
+/*
+ * SYNC Timer Delay definition used to set the expiry time
+ */
+#define SIERRA_NET_SYNCDELAY (2*HZ)
+
+/* Max. MTU supported. The modem buffers are limited to 1500 */
+#define SIERRA_NET_MAX_SUPPORTED_MTU	1500
+
+/* The SIERRA_NET_USBCTL_BUF_LEN defines a buffer size allocated for control
+ * message reception ... and thus the max. received packet.
+ * (May be the cause for parse_hip returning -EINVAL)
+ */
+#define SIERRA_NET_USBCTL_BUF_LEN	1024
+
+/* list of interface numbers - used for constructing interface lists */
+struct sierra_net_iface_info {
+	const u32 infolen;	/* number of interface numbers on list */
+	const u8  *ifaceinfo;	/* pointer to the array holding the numbers */
+};
+
+struct sierra_net_info_data {
+	u16 rx_urb_size;
+	struct sierra_net_iface_info whitelist;
+};
+
+/* Private data structure */
+struct sierra_net_data {
+
+	u8 ethr_hdr_tmpl[ETH_HLEN]; /* ethernet header template for rx'd pkts */
+
+	u16 link_up;		/* air link up or down */
+	u8 tx_hdr_template[4];	/* part of HIP hdr for tx'd packets */
+
+	u8 sync_msg[4];		/* SYNC message */
+	u8 shdwn_msg[4];	/* Shutdown message */
+
+	/* Backpointer to the container */
+	struct usbnet *usbnet;
+
+	u8 ifnum;	/* interface number */
+
+/* Bit masks, must be a power of 2 */
+#define SIERRA_NET_EVENT_RESP_AVAIL    0x01
+#define SIERRA_NET_TIMER_EXPIRY        0x02
+	unsigned long kevent_flags;
+	struct work_struct sierra_net_kevent;
+	struct timer_list sync_timer; /* For retrying SYNC sequence */
+};
+
+struct param {
+	int is_present;
+	union {
+		void  *ptr;
+		u32    dword;
+		u16    word;
+		u8     byte;
+	};
+};
+
+/* HIP message type */
+#define SIERRA_NET_HIP_EXTENDEDID	0x7F
+#define SIERRA_NET_HIP_HSYNC_ID		0x60	/* Modem -> host */
+#define SIERRA_NET_HIP_RESTART_ID	0x62	/* Modem -> host */
+#define SIERRA_NET_HIP_MSYNC_ID		0x20	/* Host -> modem */
+#define SIERRA_NET_HIP_SHUTD_ID		0x26	/* Host -> modem */
+
+#define SIERRA_NET_HIP_EXT_IP_IN_ID   0x0202
+#define SIERRA_NET_HIP_EXT_IP_OUT_ID  0x0002
+
+/* 3G UMTS Link Sense Indication definitions */
+#define SIERRA_NET_HIP_LSI_UMTSID	0x78
+
+/* Reverse Channel Grant Indication HIP message */
+#define SIERRA_NET_HIP_RCGI		0x64
+
+/* LSI Protocol types */
+#define SIERRA_NET_PROTOCOL_UMTS      0x01
+/* LSI Coverage */
+#define SIERRA_NET_COVERAGE_NONE      0x00
+#define SIERRA_NET_COVERAGE_NOPACKET  0x01
+
+/* LSI Session */
+#define SIERRA_NET_SESSION_IDLE       0x00
+/* LSI Link types */
+#define SIERRA_NET_AS_LINK_TYPE_IPv4  0x00
+
+struct lsi_umts {
+	u8 protocol;
+	u8 unused1;
+	__be16 length;
+	/* eventually use a union for the rest - assume umts for now */
+	u8 coverage;
+	u8 unused2[41];
+	u8 session_state;
+	u8 unused3[33];
+	u8 link_type;
+	u8 pdp_addr_len; /* NW-supplied PDP address len */
+	u8 pdp_addr[16]; /* NW-supplied PDP address (bigendian)) */
+	u8 unused4[23];
+	u8 dns1_addr_len; /* NW-supplied 1st DNS address len (bigendian) */
+	u8 dns1_addr[16]; /* NW-supplied 1st DNS address */
+	u8 dns2_addr_len; /* NW-supplied 2nd DNS address len */
+	u8 dns2_addr[16]; /* NW-supplied 2nd DNS address (bigendian)*/
+	u8 wins1_addr_len; /* NW-supplied 1st Wins address len */
+	u8 wins1_addr[16]; /* NW-supplied 1st Wins address (bigendian)*/
+	u8 wins2_addr_len; /* NW-supplied 2nd Wins address len */
+	u8 wins2_addr[16]; /* NW-supplied 2nd Wins address (bigendian) */
+	u8 unused5[4];
+	u8 gw_addr_len; /* NW-supplied GW address len */
+	u8 gw_addr[16]; /* NW-supplied GW address (bigendian) */
+	u8 reserved[8];
+} __attribute__ ((packed));
+
+#define SIERRA_NET_LSI_COMMON_LEN      4
+#define SIERRA_NET_LSI_UMTS_LEN        (sizeof(struct lsi_umts))
+#define SIERRA_NET_LSI_UMTS_STATUS_LEN \
+	(SIERRA_NET_LSI_UMTS_LEN - SIERRA_NET_LSI_COMMON_LEN)
+
+/* Forward definitions */
+static void sierra_sync_timer(unsigned long syncdata);
+static int sierra_net_change_mtu(struct net_device *net, int new_mtu);
+
+/* Our own net device operations structure */
+static const struct net_device_ops sierra_net_device_ops = {
+	.ndo_open               = usbnet_open,
+	.ndo_stop               = usbnet_stop,
+	.ndo_start_xmit         = usbnet_start_xmit,
+	.ndo_tx_timeout         = usbnet_tx_timeout,
+	.ndo_change_mtu         = sierra_net_change_mtu,
+	.ndo_set_mac_address    = eth_mac_addr,
+	.ndo_validate_addr      = eth_validate_addr,
+};
+
+/* get private data associated with passed in usbnet device */
+static inline struct sierra_net_data *sierra_net_get_private(struct usbnet *dev)
+{
+	return (struct sierra_net_data *)dev->data[0];
+}
+
+/* set private data associated with passed in usbnet device */
+static inline void sierra_net_set_private(struct usbnet *dev,
+			struct sierra_net_data *priv)
+{
+	dev->data[0] = (unsigned long)priv;
+}
+
+/* is packet IPv4 */
+static inline int is_ip(struct sk_buff *skb)
+{
+	return (skb->protocol == cpu_to_be16(ETH_P_IP));
+}
+
+/*
+ * check passed in packet and make sure that:
+ *  - it is linear (no scatter/gather)
+ *  - it is ethernet (mac_header properly set)
+ */
+static int check_ethip_packet(struct sk_buff *skb, struct usbnet *dev)
+{
+	skb_reset_mac_header(skb); /* ethernet header */
+
+	if (skb_is_nonlinear(skb)) {
+		netdev_err(dev->net, "Non linear buffer-dropping\n");
+		return 0;
+	}
+
+	if (!pskb_may_pull(skb, ETH_HLEN))
+		return 0;
+	skb->protocol = eth_hdr(skb)->h_proto;
+
+	return 1;
+}
+
+static const u8 *save16bit(struct param *p, const u8 *datap)
+{
+	p->is_present = 1;
+	p->word = get_unaligned_be16(datap);
+	return datap + sizeof(p->word);
+}
+
+static const u8 *save8bit(struct param *p, const u8 *datap)
+{
+	p->is_present = 1;
+	p->byte = *datap;
+	return datap + sizeof(p->byte);
+}
+
+/*----------------------------------------------------------------------------*
+ *                              BEGIN HIP                                     *
+ *----------------------------------------------------------------------------*/
+/* HIP header */
+#define SIERRA_NET_HIP_HDR_LEN 4
+/* Extended HIP header */
+#define SIERRA_NET_HIP_EXT_HDR_LEN 6
+
+struct hip_hdr {
+	int    hdrlen;
+	struct param payload_len;
+	struct param msgid;
+	struct param msgspecific;
+	struct param extmsgid;
+};
+
+static int parse_hip(const u8 *buf, const u32 buflen, struct hip_hdr *hh)
+{
+	const u8 *curp = buf;
+	int    padded;
+
+	if (buflen < SIERRA_NET_HIP_HDR_LEN)
+		return -EPROTO;
+
+	curp = save16bit(&hh->payload_len, curp);
+	curp = save8bit(&hh->msgid, curp);
+	curp = save8bit(&hh->msgspecific, curp);
+
+	padded = hh->msgid.byte & 0x80;
+	hh->msgid.byte &= 0x7F;			/* 7 bits */
+
+	hh->extmsgid.is_present = (hh->msgid.byte == SIERRA_NET_HIP_EXTENDEDID);
+	if (hh->extmsgid.is_present) {
+		if (buflen < SIERRA_NET_HIP_EXT_HDR_LEN)
+			return -EPROTO;
+
+		hh->payload_len.word &= 0x3FFF; /* 14 bits */
+
+		curp = save16bit(&hh->extmsgid, curp);
+		hh->extmsgid.word &= 0x03FF;	/* 10 bits */
+
+		hh->hdrlen = SIERRA_NET_HIP_EXT_HDR_LEN;
+	} else {
+		hh->payload_len.word &= 0x07FF;	/* 11 bits */
+		hh->hdrlen = SIERRA_NET_HIP_HDR_LEN;
+	}
+
+	if (padded) {
+		hh->hdrlen++;
+		hh->payload_len.word--;
+	}
+
+	/* if real packet shorter than the claimed length */
+	if (buflen < (hh->hdrlen + hh->payload_len.word))
+		return -EINVAL;
+
+	return 0;
+}
+
+static void build_hip(u8 *buf, const u16 payloadlen,
+		struct sierra_net_data *priv)
+{
+	/* the following doesn't have the full functionality. We
+	 * currently build only one kind of header, so it is faster this way
+	 */
+	put_unaligned_be16(payloadlen, buf);
+	memcpy(buf+2, priv->tx_hdr_template, sizeof(priv->tx_hdr_template));
+}
+/*----------------------------------------------------------------------------*
+ *                              END HIP                                       *
+ *----------------------------------------------------------------------------*/
+
+static int sierra_net_send_cmd(struct usbnet *dev,
+		u8 *cmd, int cmdlen, const char * cmd_name)
+{
+	struct sierra_net_data *priv = sierra_net_get_private(dev);
+	int  status;
+
+	status = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
+			USB_CDC_SEND_ENCAPSULATED_COMMAND,
+			USB_DIR_OUT|USB_TYPE_CLASS|USB_RECIP_INTERFACE,	0,
+			priv->ifnum, cmd, cmdlen, USB_CTRL_SET_TIMEOUT);
+
+	if (status != cmdlen && status != -ENODEV)
+		netdev_err(dev->net, "Submit %s failed %d\n", cmd_name, status);
+
+	return status;
+}
+
+static int sierra_net_send_sync(struct usbnet *dev)
+{
+	int  status;
+	struct sierra_net_data *priv = sierra_net_get_private(dev);
+
+	dev_dbg(&dev->udev->dev, "%s", __func__);
+
+	status = sierra_net_send_cmd(dev, priv->sync_msg,
+			sizeof(priv->sync_msg), "SYNC");
+
+	return status;
+}
+
+static void sierra_net_set_ctx_index(struct sierra_net_data *priv, u8 ctx_ix)
+{
+	dev_dbg(&(priv->usbnet->udev->dev), "%s %d", __func__, ctx_ix);
+	priv->tx_hdr_template[0] = 0x3F;
+	priv->tx_hdr_template[1] = ctx_ix;
+	*((u16 *)&priv->tx_hdr_template[2]) =
+		cpu_to_be16(SIERRA_NET_HIP_EXT_IP_OUT_ID);
+}
+
+static inline int sierra_net_is_valid_addrlen(u8 len)
+{
+	return (len == sizeof(struct in_addr));
+}
+
+static int sierra_net_parse_lsi(struct usbnet *dev, char *data, int datalen)
+{
+	struct lsi_umts *lsi = (struct lsi_umts *)data;
+
+	if (datalen < sizeof(struct lsi_umts)) {
+		netdev_err(dev->net, "%s: Data length %d, exp %Zu\n",
+				__func__, datalen,
+				sizeof(struct lsi_umts));
+		return -1;
+	}
+
+	if (lsi->length != cpu_to_be16(SIERRA_NET_LSI_UMTS_STATUS_LEN)) {
+		netdev_err(dev->net, "%s: LSI_UMTS_STATUS_LEN %d, exp %u\n",
+				__func__, be16_to_cpu(lsi->length),
+				(u32)SIERRA_NET_LSI_UMTS_STATUS_LEN);
+		return -1;
+	}
+
+	/* Validate the protocol  - only support UMTS for now */
+	if (lsi->protocol != SIERRA_NET_PROTOCOL_UMTS) {
+		netdev_err(dev->net, "Protocol unsupported, 0x%02x\n",
+			lsi->protocol);
+		return -1;
+	}
+
+	/* Validate the link type */
+	if (lsi->link_type != SIERRA_NET_AS_LINK_TYPE_IPv4) {
+		netdev_err(dev->net, "Link type unsupported: 0x%02x\n",
+			lsi->link_type);
+		return -1;
+	}
+
+	/* Validate the coverage */
+	if (lsi->coverage == SIERRA_NET_COVERAGE_NONE
+	   || lsi->coverage == SIERRA_NET_COVERAGE_NOPACKET) {
+		netdev_err(dev->net, "No coverage, 0x%02x\n", lsi->coverage);
+		return 0;
+	}
+
+	/* Validate the session state */
+	if (lsi->session_state == SIERRA_NET_SESSION_IDLE) {
+		netdev_err(dev->net, "Session idle, 0x%02x\n",
+			lsi->session_state);
+		return 0;
+	}
+
+	/* Set link_sense true */
+	return 1;
+}
+
+static void sierra_net_handle_lsi(struct usbnet *dev, char *data,
+		struct hip_hdr	*hh)
+{
+	struct sierra_net_data *priv = sierra_net_get_private(dev);
+	int link_up;
+
+	link_up = sierra_net_parse_lsi(dev, data + hh->hdrlen,
+					hh->payload_len.word);
+	if (link_up < 0) {
+		netdev_err(dev->net, "Invalid LSI\n");
+		return;
+	}
+	if (link_up) {
+		sierra_net_set_ctx_index(priv, hh->msgspecific.byte);
+		priv->link_up = 1;
+		netif_carrier_on(dev->net);
+	} else {
+		priv->link_up = 0;
+		netif_carrier_off(dev->net);
+	}
+}
+
+static void sierra_net_dosync(struct usbnet *dev)
+{
+	int status;
+	struct sierra_net_data *priv = sierra_net_get_private(dev);
+
+	dev_dbg(&dev->udev->dev, "%s", __func__);
+
+	/* tell modem we are ready */
+	status = sierra_net_send_sync(dev);
+	if (status < 0)
+		netdev_err(dev->net,
+			"Send SYNC failed, status %d\n", status);
+	status = sierra_net_send_sync(dev);
+	if (status < 0)
+		netdev_err(dev->net,
+			"Send SYNC failed, status %d\n", status);
+
+	/* Now, start a timer and make sure we get the Restart Indication */
+	priv->sync_timer.function = sierra_sync_timer;
+	priv->sync_timer.data = (unsigned long) dev;
+	priv->sync_timer.expires = jiffies + SIERRA_NET_SYNCDELAY;
+	add_timer(&priv->sync_timer);
+}
+
+static void sierra_net_kevent(struct work_struct *work)
+{
+	struct sierra_net_data *priv =
+		container_of(work, struct sierra_net_data, sierra_net_kevent);
+	struct usbnet *dev = priv->usbnet;
+	int  len;
+	int  err;
+	u8  *buf;
+	u8   ifnum;
+
+	if (test_bit(SIERRA_NET_EVENT_RESP_AVAIL, &priv->kevent_flags)) {
+		clear_bit(SIERRA_NET_EVENT_RESP_AVAIL, &priv->kevent_flags);
+
+		/* Query the modem for the LSI message */
+		buf = kzalloc(SIERRA_NET_USBCTL_BUF_LEN, GFP_KERNEL);
+		if (!buf) {
+			netdev_err(dev->net,
+				"failed to allocate buf for LS msg\n");
+			return;
+		}
+		ifnum = priv->ifnum;
+		len = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
+				USB_CDC_GET_ENCAPSULATED_RESPONSE,
+				USB_DIR_IN|USB_TYPE_CLASS|USB_RECIP_INTERFACE,
+				0, ifnum, buf, SIERRA_NET_USBCTL_BUF_LEN,
+				USB_CTRL_SET_TIMEOUT);
+
+		if (len < 0) {
+			netdev_err(dev->net,
+				"usb_control_msg failed, status %d\n", len);
+		} else {
+			struct hip_hdr	hh;
+
+			dev_dbg(&dev->udev->dev, "%s: Received status message,"
+				" %04x bytes", __func__, len);
+
+			err = parse_hip(buf, len, &hh);
+			if (err) {
+				netdev_err(dev->net, "%s: Bad packet,"
+					" parse result %d\n", __func__, err);
+				kfree(buf);
+				return;
+			}
+
+			/* Validate packet length */
+			if (len != hh.hdrlen + hh.payload_len.word) {
+				netdev_err(dev->net, "%s: Bad packet, received"
+					" %d, expected %d\n",	__func__, len,
+					hh.hdrlen + hh.payload_len.word);
+				kfree(buf);
+				return;
+			}
+
+			/* Switch on received message types */
+			switch (hh.msgid.byte) {
+			case SIERRA_NET_HIP_LSI_UMTSID:
+				dev_dbg(&dev->udev->dev, "LSI for ctx:%d",
+					hh.msgspecific.byte);
+				sierra_net_handle_lsi(dev, buf, &hh);
+				break;
+			case SIERRA_NET_HIP_RESTART_ID:
+				dev_dbg(&dev->udev->dev, "Restart reported: %d,"
+						" stopping sync timer",
+						hh.msgspecific.byte);
+				/* Got sync resp - stop timer & clear mask */
+				del_timer_sync(&priv->sync_timer);
+				clear_bit(SIERRA_NET_TIMER_EXPIRY,
+					  &priv->kevent_flags);
+				break;
+			case SIERRA_NET_HIP_HSYNC_ID:
+				dev_dbg(&dev->udev->dev, "SYNC received");
+				err = sierra_net_send_sync(dev);
+				if (err < 0)
+					netdev_err(dev->net,
+						"Send SYNC failed %d\n", err);
+				break;
+			case SIERRA_NET_HIP_EXTENDEDID:
+				netdev_err(dev->net, "Unrecognized HIP msg, "
+					"extmsgid 0x%04x\n", hh.extmsgid.word);
+				break;
+			case SIERRA_NET_HIP_RCGI:
+				/* Ignored */
+				break;
+			default:
+				netdev_err(dev->net, "Unrecognized HIP msg, "
+					"msgid 0x%02x\n", hh.msgid.byte);
+				break;
+			}
+		}
+		kfree(buf);
+	}
+	/* The sync timer bit might be set */
+	if (test_bit(SIERRA_NET_TIMER_EXPIRY, &priv->kevent_flags)) {
+		clear_bit(SIERRA_NET_TIMER_EXPIRY, &priv->kevent_flags);
+		dev_dbg(&dev->udev->dev, "Deferred sync timer expiry");
+		sierra_net_dosync(priv->usbnet);
+	}
+
+	if (priv->kevent_flags)
+		dev_dbg(&dev->udev->dev, "sierra_net_kevent done, "
+			"kevent_flags = 0x%lx", priv->kevent_flags);
+}
+
+static void sierra_net_defer_kevent(struct usbnet *dev, int work)
+{
+	struct sierra_net_data *priv = sierra_net_get_private(dev);
+
+	set_bit(work, &priv->kevent_flags);
+	schedule_work(&priv->sierra_net_kevent);
+}
+
+/*
+ * Sync Retransmit Timer Handler. On expiry, kick the work queue
+ */
+void sierra_sync_timer(unsigned long syncdata)
+{
+	struct usbnet *dev = (struct usbnet *)syncdata;
+
+	dev_dbg(&dev->udev->dev, "%s", __func__);
+	/* Kick the tasklet */
+	sierra_net_defer_kevent(dev, SIERRA_NET_TIMER_EXPIRY);
+}
+
+static void sierra_net_status(struct usbnet *dev, struct urb *urb)
+{
+	struct usb_cdc_notification *event;
+
+	dev_dbg(&dev->udev->dev, "%s", __func__);
+
+	if (urb->actual_length < sizeof *event)
+		return;
+
+	/* Add cases to handle other standard notifications. */
+	event = urb->transfer_buffer;
+	switch (event->bNotificationType) {
+	case USB_CDC_NOTIFY_NETWORK_CONNECTION:
+	case USB_CDC_NOTIFY_SPEED_CHANGE:
+		/* USB 305 sends those */
+		break;
+	case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
+		sierra_net_defer_kevent(dev, SIERRA_NET_EVENT_RESP_AVAIL);
+		break;
+	default:
+		netdev_err(dev->net, ": unexpected notification %02x!\n",
+				event->bNotificationType);
+		break;
+	}
+}
+
+static void sierra_net_get_drvinfo(struct net_device *net,
+		struct ethtool_drvinfo *info)
+{
+	/* Inherit standard device info */
+	usbnet_get_drvinfo(net, info);
+	strncpy(info->driver, driver_name, sizeof info->driver);
+	strncpy(info->version, DRIVER_VERSION, sizeof info->version);
+}
+
+static u32 sierra_net_get_link(struct net_device *net)
+{
+	struct usbnet *dev = netdev_priv(net);
+	/* Report link is down whenever the interface is down */
+	return sierra_net_get_private(dev)->link_up && netif_running(net);
+}
+
+static struct ethtool_ops sierra_net_ethtool_ops = {
+	.get_drvinfo = sierra_net_get_drvinfo,
+	.get_link = sierra_net_get_link,
+	.get_msglevel = usbnet_get_msglevel,
+	.set_msglevel = usbnet_set_msglevel,
+	.get_settings = usbnet_get_settings,
+	.set_settings = usbnet_set_settings,
+	.nway_reset = usbnet_nway_reset,
+};
+
+/* MTU can not be more than 1500 bytes, enforce it. */
+static int sierra_net_change_mtu(struct net_device *net, int new_mtu)
+{
+	if (new_mtu > SIERRA_NET_MAX_SUPPORTED_MTU)
+		return -EINVAL;
+
+	return usbnet_change_mtu(net, new_mtu);
+}
+
+static int is_whitelisted(const u8 ifnum,
+			const struct sierra_net_iface_info *whitelist)
+{
+	if (whitelist) {
+		const u8 *list = whitelist->ifaceinfo;
+		int i;
+
+		for (i = 0; i < whitelist->infolen; i++) {
+			if (list[i] == ifnum)
+				return 1;
+		}
+	}
+	return 0;
+}
+
+static int sierra_net_get_fw_attr(struct usbnet *dev, u16 *datap)
+{
+	int result = 0;
+	u16 *attrdata;
+
+	attrdata = kmalloc(sizeof(*attrdata), GFP_KERNEL);
+	if (!attrdata)
+		return -ENOMEM;
+
+	result = usb_control_msg(
+			dev->udev,
+			usb_rcvctrlpipe(dev->udev, 0),
+			/* _u8 vendor specific request */
+			SWI_USB_REQUEST_GET_FW_ATTR,
+			USB_DIR_IN | USB_TYPE_VENDOR,	/* __u8 request type */
+			0x0000,		/* __u16 value not used */
+			0x0000,		/* __u16 index  not used */
+			attrdata,	/* char *data */
+			sizeof(*attrdata),		/* __u16 size */
+			USB_CTRL_SET_TIMEOUT);	/* int timeout */
+
+	if (result < 0) {
+		kfree(attrdata);
+		return -EIO;
+	}
+
+	*datap = *attrdata;
+
+	kfree(attrdata);
+	return result;
+}
+
+/*
+ * collects the bulk endpoints, the status endpoint.
+ */
+static int sierra_net_bind(struct usbnet *dev, struct usb_interface *intf)
+{
+	u8	ifacenum;
+	u8	numendpoints;
+	u16	fwattr = 0;
+	int	status;
+	struct ethhdr *eth;
+	struct sierra_net_data *priv;
+	static const u8 sync_tmplate[sizeof(priv->sync_msg)] = {
+		0x00, 0x00, SIERRA_NET_HIP_MSYNC_ID, 0x00};
+	static const u8 shdwn_tmplate[sizeof(priv->shdwn_msg)] = {
+		0x00, 0x00, SIERRA_NET_HIP_SHUTD_ID, 0x00};
+
+	struct sierra_net_info_data *data =
+			(struct sierra_net_info_data *)dev->driver_info->data;
+
+	dev_dbg(&dev->udev->dev, "%s", __func__);
+
+	ifacenum = intf->cur_altsetting->desc.bInterfaceNumber;
+	/* We only accept certain interfaces */
+	if (!is_whitelisted(ifacenum, &data->whitelist)) {
+		dev_dbg(&dev->udev->dev, "Ignoring interface: %d", ifacenum);
+		return -ENODEV;
+	}
+	numendpoints = intf->cur_altsetting->desc.bNumEndpoints;
+	/* We have three endpoints, bulk in and out, and a status */
+	if (numendpoints != 3) {
+		dev_err(&dev->udev->dev, "Expected 3 endpoints, found: %d",
+			numendpoints);
+		return -ENODEV;
+	}
+	/* Status endpoint set in usbnet_get_endpoints() */
+	dev->status = NULL;
+	status = usbnet_get_endpoints(dev, intf);
+	if (status < 0) {
+		dev_err(&dev->udev->dev, "Error in usbnet_get_endpoints (%d)",
+			status);
+		return -ENODEV;
+	}
+	/* Initialize sierra private data */
+	priv = kzalloc(sizeof *priv, GFP_KERNEL);
+	if (!priv) {
+		dev_err(&dev->udev->dev, "No memory");
+		return -ENOMEM;
+	}
+
+	priv->usbnet = dev;
+	priv->ifnum = ifacenum;
+	dev->net->netdev_ops = &sierra_net_device_ops;
+
+	/* change MAC addr to include, ifacenum, and to be unique */
+	dev->net->dev_addr[ETH_ALEN-2] = atomic_inc_return(&iface_counter);
+	dev->net->dev_addr[ETH_ALEN-1] = ifacenum;
+
+	/* we will have to manufacture ethernet headers, prepare template */
+	eth = (struct ethhdr *)priv->ethr_hdr_tmpl;
+	memcpy(&eth->h_dest, dev->net->dev_addr, ETH_ALEN);
+	eth->h_proto = cpu_to_be16(ETH_P_IP);
+
+	/* prepare shutdown message template */
+	memcpy(priv->shdwn_msg, shdwn_tmplate, sizeof(priv->shdwn_msg));
+	/* set context index initially to 0 - prepares tx hdr template */
+	sierra_net_set_ctx_index(priv, 0);
+
+	/* decrease the rx_urb_size and max_tx_size to 4k on USB 1.1 */
+	dev->rx_urb_size  = data->rx_urb_size;
+	if (dev->udev->speed != USB_SPEED_HIGH)
+		dev->rx_urb_size  = min_t(size_t, 4096, data->rx_urb_size);
+
+	dev->net->hard_header_len += SIERRA_NET_HIP_EXT_HDR_LEN;
+	dev->hard_mtu = dev->net->mtu + dev->net->hard_header_len;
+
+	/* Set up the netdev */
+	dev->net->flags |= IFF_NOARP;
+	dev->net->ethtool_ops = &sierra_net_ethtool_ops;
+	netif_carrier_off(dev->net);
+
+	sierra_net_set_private(dev, priv);
+
+	priv->kevent_flags = 0;
+
+	/* Use the shared workqueue */
+	INIT_WORK(&priv->sierra_net_kevent, sierra_net_kevent);
+
+	/* Only need to do this once */
+	init_timer(&priv->sync_timer);
+
+	/* verify fw attributes */
+	status = sierra_net_get_fw_attr(dev, &fwattr);
+	dev_dbg(&dev->udev->dev, "Fw attr: %x\n", fwattr);
+
+	/* test whether firmware supports DHCP */
+	if (!(status == sizeof(fwattr) && (fwattr & SWI_GET_FW_ATTR_MASK))) {
+		/* found incompatible firmware version */
+		dev_err(&dev->udev->dev, "Incompatible driver and firmware"
+			" versions\n");
+		kfree(priv);
+		return -ENODEV;
+	}
+	/* prepare sync message from template */
+	memcpy(priv->sync_msg, sync_tmplate, sizeof(priv->sync_msg));
+
+	return 0;
+}
+
+static void sierra_net_unbind(struct usbnet *dev, struct usb_interface *intf)
+{
+	int status;
+	struct sierra_net_data *priv = sierra_net_get_private(dev);
+
+	dev_dbg(&dev->udev->dev, "%s", __func__);
+
+	/* Kill the timer then flush the work queue */
+	del_timer_sync(&priv->sync_timer);
+
+	flush_scheduled_work();
+
+	/* tell modem we are going away */
+	status = sierra_net_send_cmd(dev, priv->shdwn_msg,
+			sizeof(priv->shdwn_msg), "Shutdown");
+	if (status < 0)
+		netdev_err(dev->net,
+			"usb_control_msg failed, status %d\n", status);
+
+	sierra_net_set_private(dev, NULL);
+
+	kfree(priv);
+}
+
+static struct sk_buff *sierra_net_skb_clone(struct usbnet *dev,
+		struct sk_buff *skb, int len)
+{
+	struct sk_buff *new_skb;
+
+	/* clone skb */
+	new_skb = skb_clone(skb, GFP_ATOMIC);
+
+	/* remove len bytes from original */
+	skb_pull(skb, len);
+
+	/* trim next packet to it's length */
+	if (new_skb) {
+		skb_trim(new_skb, len);
+	} else {
+		if (netif_msg_rx_err(dev))
+			netdev_err(dev->net, "failed to get skb\n");
+		dev->net->stats.rx_dropped++;
+	}
+
+	return new_skb;
+}
+
+/* ---------------------------- Receive data path ----------------------*/
+static int sierra_net_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
+{
+	int err;
+	struct hip_hdr  hh;
+	struct sk_buff *new_skb;
+
+	dev_dbg(&dev->udev->dev, "%s", __func__);
+
+	/* could contain multiple packets */
+	while (likely(skb->len)) {
+		err = parse_hip(skb->data, skb->len, &hh);
+		if (err) {
+			if (netif_msg_rx_err(dev))
+				netdev_err(dev->net, "Invalid HIP header %d\n",
+					err);
+			/* dev->net->stats.rx_errors incremented by caller */
+			dev->net->stats.rx_length_errors++;
+			return 0;
+		}
+
+		/* Validate Extended HIP header */
+		if (!hh.extmsgid.is_present
+		    || hh.extmsgid.word != SIERRA_NET_HIP_EXT_IP_IN_ID) {
+			if (netif_msg_rx_err(dev))
+				netdev_err(dev->net, "HIP/ETH: Invalid pkt\n");
+
+			dev->net->stats.rx_frame_errors++;
+			/* dev->net->stats.rx_errors incremented by caller */;
+			return 0;
+		}
+
+		skb_pull(skb, hh.hdrlen);
+
+		/* We are going to accept this packet, prepare it */
+		memcpy(skb->data, sierra_net_get_private(dev)->ethr_hdr_tmpl,
+			ETH_HLEN);
+
+		/* Last packet in batch handled by usbnet */
+		if (hh.payload_len.word == skb->len)
+			return 1;
+
+		new_skb = sierra_net_skb_clone(dev, skb, hh.payload_len.word);
+		if (new_skb)
+			usbnet_skb_return(dev, new_skb);
+
+	} /* while */
+
+	return 0;
+}
+
+/* ---------------------------- Transmit data path ----------------------*/
+struct sk_buff *sierra_net_tx_fixup(struct usbnet *dev, struct sk_buff *skb,
+		gfp_t flags)
+{
+	struct sierra_net_data *priv = sierra_net_get_private(dev);
+	u16 len;
+	bool need_tail;
+
+	dev_dbg(&dev->udev->dev, "%s", __func__);
+	if (priv->link_up && check_ethip_packet(skb, dev) && is_ip(skb)) {
+		/* enough head room as is? */
+		if (SIERRA_NET_HIP_EXT_HDR_LEN <= skb_headroom(skb)) {
+			/* Save the Eth/IP length and set up HIP hdr */
+			len = skb->len;
+			skb_push(skb, SIERRA_NET_HIP_EXT_HDR_LEN);
+			/* Handle ZLP issue */
+			need_tail = ((len + SIERRA_NET_HIP_EXT_HDR_LEN)
+				% dev->maxpacket == 0);
+			if (need_tail) {
+				if (unlikely(skb_tailroom(skb) == 0)) {
+					netdev_err(dev->net, "tx_fixup:"
+						"no room for packet\n");
+					dev_kfree_skb_any(skb);
+					return NULL;
+				} else {
+					skb->data[skb->len] = 0;
+					__skb_put(skb, 1);
+					len = len + 1;
+				}
+			}
+			build_hip(skb->data, len, priv);
+			return skb;
+		} else {
+			/*
+			 * compensate in the future if necessary
+			 */
+			netdev_err(dev->net, "tx_fixup: no room for HIP\n");
+		} /* headroom */
+	}
+
+	if (!priv->link_up)
+		dev->net->stats.tx_carrier_errors++;
+
+	/* tx_dropped incremented by usbnet */
+
+	/* filter the packet out, release it  */
+	dev_kfree_skb_any(skb);
+	return NULL;
+}
+
+static const u8 sierra_net_ifnum_list[] = { 7, 10, 11 };
+static const struct sierra_net_info_data sierra_net_info_data_68A3 = {
+	.rx_urb_size = 8 * 1024,
+	.whitelist = {
+		.infolen = ARRAY_SIZE(sierra_net_ifnum_list),
+		.ifaceinfo = sierra_net_ifnum_list
+	}
+};
+
+static const struct driver_info sierra_net_info_68A3 = {
+	.description = "Sierra Wireless USB-to-WWAN Modem",
+	.flags = FLAG_WWAN | FLAG_SEND_ZLP,
+	.bind = sierra_net_bind,
+	.unbind = sierra_net_unbind,
+	.status = sierra_net_status,
+	.rx_fixup = sierra_net_rx_fixup,
+	.tx_fixup = sierra_net_tx_fixup,
+	.data = (unsigned long)&sierra_net_info_data_68A3,
+};
+
+static const struct usb_device_id products[] = {
+	{USB_DEVICE(0x1199, 0x68A3), /* Sierra Wireless USB-to-WWAN modem */
+	.driver_info = (unsigned long) &sierra_net_info_68A3},
+
+	{}, /* last item */
+};
+MODULE_DEVICE_TABLE(usb, products);
+
+/* We are based on usbnet, so let it handle the USB driver specifics */
+static struct usb_driver sierra_net_driver = {
+	.name = "sierra_net",
+	.id_table = products,
+	.probe = usbnet_probe,
+	.disconnect = usbnet_disconnect,
+	.suspend = usbnet_suspend,
+	.resume = usbnet_resume,
+	.no_dynamic_id = 1,
+};
+
+static int __init sierra_net_init(void)
+{
+	BUILD_BUG_ON(FIELD_SIZEOF(struct usbnet, data)
+				< sizeof(struct cdc_state));
+
+	return usb_register(&sierra_net_driver);
+}
+
+static void __exit sierra_net_exit(void)
+{
+	usb_deregister(&sierra_net_driver);
+}
+
+module_exit(sierra_net_exit);
+module_init(sierra_net_init);
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_LICENSE("GPL");