/*
 * CDC Ethernet based networking peripherals
 * Copyright (C) 2003-2005 by David Brownell
 * Copyright (C) 2006 by Ole Andre Vadla Ravnas (ActiveSync)
 *
 * 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      DEBUG                   // error path messages, extra info
// #define      VERBOSE                 // more; success messages

#include <linux/module.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/workqueue.h>
#include <linux/mii.h>
#include <linux/usb.h>
#include <linux/usb/cdc.h>
#include <linux/usb/usbnet.h>


#if defined(CONFIG_USB_NET_RNDIS_HOST) || defined(CONFIG_USB_NET_RNDIS_HOST_MODULE)

static int is_rndis(struct usb_interface_descriptor *desc)
{
        return (desc->bInterfaceClass == USB_CLASS_COMM &&
                desc->bInterfaceSubClass == 2 &&
                desc->bInterfaceProtocol == 0xff);
}

static int is_activesync(struct usb_interface_descriptor *desc)
{
        return (desc->bInterfaceClass == USB_CLASS_MISC &&
                desc->bInterfaceSubClass == 1 &&
                desc->bInterfaceProtocol == 1);
}

static int is_wireless_rndis(struct usb_interface_descriptor *desc)
{
        return (desc->bInterfaceClass == USB_CLASS_WIRELESS_CONTROLLER &&
                desc->bInterfaceSubClass == 1 &&
                desc->bInterfaceProtocol == 3);
}

#else

#define is_rndis(desc)          0
#define is_activesync(desc)     0
#define is_wireless_rndis(desc) 0

#endif

static const u8 mbm_guid[16] = {
        0xa3, 0x17, 0xa8, 0x8b, 0x04, 0x5e, 0x4f, 0x01,
        0xa6, 0x07, 0xc0, 0xff, 0xcb, 0x7e, 0x39, 0x2a,
};

/*
 * probes control interface, claims data interface, collects the bulk
 * endpoints, activates data interface (if needed), maybe sets MTU.
 * all pure cdc, except for certain firmware workarounds, and knowing
 * that rndis uses one different rule.
 */
int usbnet_generic_cdc_bind(struct usbnet *dev, struct usb_interface *intf)
{
        u8                              *buf = intf->cur_altsetting->extra;
        int                             len = intf->cur_altsetting->extralen;
        struct usb_interface_descriptor *d;
        struct cdc_state                *info = (void *) &dev->data;
        int                             status;
        int                             rndis;
        struct usb_driver               *driver = driver_of(intf);
        struct usb_cdc_mdlm_desc        *desc = NULL;
        struct usb_cdc_mdlm_detail_desc *detail = NULL;

        if (sizeof dev->data < sizeof *info)
                return -EDOM;

        /* expect strict spec conformance for the descriptors, but
         * cope with firmware which stores them in the wrong place
         */
        if (len == 0 && dev->udev->actconfig->extralen) {
                /* Motorola SB4100 (and others: Brad Hards says it's
                 * from a Broadcom design) put CDC descriptors here
                 */
                buf = dev->udev->actconfig->extra;
                len = dev->udev->actconfig->extralen;
                dev_dbg(&intf->dev, "CDC descriptors on config\n");
        }

        /* Maybe CDC descriptors are after the endpoint?  This bug has
         * been seen on some 2Wire Inc RNDIS-ish products.
         */
        if (len == 0) {
                struct usb_host_endpoint        *hep;

                hep = intf->cur_altsetting->endpoint;
                if (hep) {
                        buf = hep->extra;
                        len = hep->extralen;
                }
                if (len)
                        dev_dbg(&intf->dev,
                                "CDC descriptors on endpoint\n");
        }

        /* this assumes that if there's a non-RNDIS vendor variant
         * of cdc-acm, it'll fail RNDIS requests cleanly.
         */
        rndis = (is_rndis(&intf->cur_altsetting->desc) ||
                 is_activesync(&intf->cur_altsetting->desc) ||
                 is_wireless_rndis(&intf->cur_altsetting->desc));

        memset(info, 0, sizeof *info);
        info->control = intf;
        while (len > 3) {
                if (buf [1] != USB_DT_CS_INTERFACE)
                        goto next_desc;

                /* use bDescriptorSubType to identify the CDC descriptors.
                 * We expect devices with CDC header and union descriptors.
                 * For CDC Ethernet we need the ethernet descriptor.
                 * For RNDIS, ignore two (pointless) CDC modem descriptors
                 * in favor of a complicated OID-based RPC scheme doing what
                 * CDC Ethernet achieves with a simple descriptor.
                 */
                switch (buf [2]) {
                case USB_CDC_HEADER_TYPE:
                        if (info->header) {
                                dev_dbg(&intf->dev, "extra CDC header\n");
                                goto bad_desc;
                        }
                        info->header = (void *) buf;
                        if (info->header->bLength != sizeof *info->header) {
                                dev_dbg(&intf->dev, "CDC header len %u\n",
                                        info->header->bLength);
                                goto bad_desc;
                        }
                        break;
                case USB_CDC_ACM_TYPE:
                        /* paranoia:  disambiguate a "real" vendor-specific
                         * modem interface from an RNDIS non-modem.
                         */
                        if (rndis) {
                                struct usb_cdc_acm_descriptor *acm;

                                acm = (void *) buf;
                                if (acm->bmCapabilities) {
                                        dev_dbg(&intf->dev,
                                                "ACM capabilities %02x, "
                                                "not really RNDIS?\n",
                                                acm->bmCapabilities);
                                        goto bad_desc;
                                }
                        }
                        break;
                case USB_CDC_UNION_TYPE:
                        if (info->u) {
                                dev_dbg(&intf->dev, "extra CDC union\n");
                                goto bad_desc;
                        }
                        info->u = (void *) buf;
                        if (info->u->bLength != sizeof *info->u) {
                                dev_dbg(&intf->dev, "CDC union len %u\n",
                                        info->u->bLength);
                                goto bad_desc;
                        }

                        /* we need a master/control interface (what we're
                         * probed with) and a slave/data interface; union
                         * descriptors sort this all out.
                         */
                        info->control = usb_ifnum_to_if(dev->udev,
                                                info->u->bMasterInterface0);
                        info->data = usb_ifnum_to_if(dev->udev,
                                                info->u->bSlaveInterface0);
                        if (!info->control || !info->data) {
                                dev_dbg(&intf->dev,
                                        "master #%u/%p slave #%u/%p\n",
                                        info->u->bMasterInterface0,
                                        info->control,
                                        info->u->bSlaveInterface0,
                                        info->data);
                                goto bad_desc;
                        }
                        if (info->control != intf) {
                                dev_dbg(&intf->dev, "bogus CDC Union\n");
                                /* Ambit USB Cable Modem (and maybe others)
                                 * interchanges master and slave interface.
                                 */
                                if (info->data == intf) {
                                        info->data = info->control;
                                        info->control = intf;
                                } else
                                        goto bad_desc;
                        }

                        /* a data interface altsetting does the real i/o */
                        d = &info->data->cur_altsetting->desc;
                        if (d->bInterfaceClass != USB_CLASS_CDC_DATA) {
                                dev_dbg(&intf->dev, "slave class %u\n",
                                        d->bInterfaceClass);
                                goto bad_desc;
                        }
                        break;
                case USB_CDC_ETHERNET_TYPE:
                        if (info->ether) {
                                dev_dbg(&intf->dev, "extra CDC ether\n");
                                goto bad_desc;
                        }
                        info->ether = (void *) buf;
                        if (info->ether->bLength != sizeof *info->ether) {
                                dev_dbg(&intf->dev, "CDC ether len %u\n",
                                        info->ether->bLength);
                                goto bad_desc;
                        }
                        dev->hard_mtu = le16_to_cpu(
                                                info->ether->wMaxSegmentSize);
                        /* because of Zaurus, we may be ignoring the host
                         * side link address we were given.
                         */
                        break;
                case USB_CDC_MDLM_TYPE:
                        if (desc) {
                                dev_dbg(&intf->dev, "extra MDLM descriptor\n");
                                goto bad_desc;
                        }

                        desc = (void *)buf;

                        if (desc->bLength != sizeof(*desc))
                                goto bad_desc;

                        if (memcmp(&desc->bGUID, mbm_guid, 16))
                                goto bad_desc;
                        break;
                case USB_CDC_MDLM_DETAIL_TYPE:
                        if (detail) {
                                dev_dbg(&intf->dev, "extra MDLM detail descriptor\n");
                                goto bad_desc;
                        }

                        detail = (void *)buf;

                        if (detail->bGuidDescriptorType == 0) {
                                if (detail->bLength < (sizeof(*detail) + 1))
                                        goto bad_desc;
                        } else
                                goto bad_desc;
                        break;
                }
next_desc:
                len -= buf [0]; /* bLength */
                buf += buf [0];
        }

        /* Microsoft ActiveSync based and some regular RNDIS devices lack the
         * CDC descriptors, so we'll hard-wire the interfaces and not check
         * for descriptors.
         */
        if (rndis && !info->u) {
                info->control = usb_ifnum_to_if(dev->udev, 0);
                info->data = usb_ifnum_to_if(dev->udev, 1);
                if (!info->control || !info->data) {
                        dev_dbg(&intf->dev,
                                "rndis: master #0/%p slave #1/%p\n",
                                info->control,
                                info->data);
                        goto bad_desc;
                }

        } else if (!info->header || !info->u || (!rndis && !info->ether)) {
                dev_dbg(&intf->dev, "missing cdc %s%s%sdescriptor\n",
                        info->header ? "" : "header ",
                        info->u ? "" : "union ",
                        info->ether ? "" : "ether ");
                goto bad_desc;
        }

        /* claim data interface and set it up ... with side effects.
         * network traffic can't flow until an altsetting is enabled.
         */
        status = usb_driver_claim_interface(driver, info->data, dev);
        if (status < 0)
                return status;
        status = usbnet_get_endpoints(dev, info->data);
        if (status < 0) {
                /* ensure immediate exit from usbnet_disconnect */
                usb_set_intfdata(info->data, NULL);
                usb_driver_release_interface(driver, info->data);
                return status;
        }

        /* status endpoint: optional for CDC Ethernet, not RNDIS (or ACM) */
        dev->status = NULL;
        if (info->control->cur_altsetting->desc.bNumEndpoints == 1) {
                struct usb_endpoint_descriptor  *desc;

                dev->status = &info->control->cur_altsetting->endpoint [0];
                desc = &dev->status->desc;
                if (!usb_endpoint_is_int_in(desc) ||
                    (le16_to_cpu(desc->wMaxPacketSize)
                     < sizeof(struct usb_cdc_notification)) ||
                    !desc->bInterval) {
                        dev_dbg(&intf->dev, "bad notification endpoint\n");
                        dev->status = NULL;
                }
        }
        if (rndis && !dev->status) {
                dev_dbg(&intf->dev, "missing RNDIS status endpoint\n");
                usb_set_intfdata(info->data, NULL);
                usb_driver_release_interface(driver, info->data);
                return -ENODEV;
        }
        return 0;

bad_desc:
        dev_info(&dev->udev->dev, "bad CDC descriptors\n");
        return -ENODEV;
}
EXPORT_SYMBOL_GPL(usbnet_generic_cdc_bind);

void usbnet_cdc_unbind(struct usbnet *dev, struct usb_interface *intf)
{
        struct cdc_state                *info = (void *) &dev->data;
        struct usb_driver               *driver = driver_of(intf);

        /* disconnect master --> disconnect slave */
        if (intf == info->control && info->data) {
                /* ensure immediate exit from usbnet_disconnect */
                usb_set_intfdata(info->data, NULL);
                usb_driver_release_interface(driver, info->data);
                info->data = NULL;
        }

        /* and vice versa (just in case) */
        else if (intf == info->data && info->control) {
                /* ensure immediate exit from usbnet_disconnect */
                usb_set_intfdata(info->control, NULL);
                usb_driver_release_interface(driver, info->control);
                info->control = NULL;
        }
}
EXPORT_SYMBOL_GPL(usbnet_cdc_unbind);

/*-------------------------------------------------------------------------
 *
 * Communications Device Class, Ethernet Control model
 *
 * Takes two interfaces.  The DATA interface is inactive till an altsetting
 * is selected.  Configuration data includes class descriptors.  There's
 * an optional status endpoint on the control interface.
 *
 * This should interop with whatever the 2.4 "CDCEther.c" driver
 * (by Brad Hards) talked with, with more functionality.
 *
 *-------------------------------------------------------------------------*/

static void dumpspeed(struct usbnet *dev, __le32 *speeds)
{
        netif_info(dev, timer, dev->net,
                   "link speeds: %u kbps up, %u kbps down\n",
                   __le32_to_cpu(speeds[0]) / 1000,
                   __le32_to_cpu(speeds[1]) / 1000);
}

void usbnet_cdc_status(struct usbnet *dev, struct urb *urb)
{
        struct usb_cdc_notification     *event;

        if (urb->actual_length < sizeof *event)
                return;

        /* SPEED_CHANGE can get split into two 8-byte packets */
        if (test_and_clear_bit(EVENT_STS_SPLIT, &dev->flags)) {
                dumpspeed(dev, (__le32 *) urb->transfer_buffer);
                return;
        }

        event = urb->transfer_buffer;
        switch (event->bNotificationType) {
        case USB_CDC_NOTIFY_NETWORK_CONNECTION:
                netif_dbg(dev, timer, dev->net, "CDC: carrier %s\n",
                          event->wValue ? "on" : "off");
                if (event->wValue)
                        netif_carrier_on(dev->net);
                else
                        netif_carrier_off(dev->net);
                break;
        case USB_CDC_NOTIFY_SPEED_CHANGE:       /* tx/rx rates */
                netif_dbg(dev, timer, dev->net, "CDC: speed change (len %d)\n",
                          urb->actual_length);
                if (urb->actual_length != (sizeof *event + 8))
                        set_bit(EVENT_STS_SPLIT, &dev->flags);
                else
                        dumpspeed(dev, (__le32 *) &event[1]);
                break;
        /* USB_CDC_NOTIFY_RESPONSE_AVAILABLE can happen too (e.g. RNDIS),
         * but there are no standard formats for the response data.
         */
        default:
                netdev_err(dev->net, "CDC: unexpected notification %02x!\n",
                           event->bNotificationType);
                break;
        }
}
EXPORT_SYMBOL_GPL(usbnet_cdc_status);

int usbnet_cdc_bind(struct usbnet *dev, struct usb_interface *intf)
{
        int                             status;
        struct cdc_state                *info = (void *) &dev->data;

        status = usbnet_generic_cdc_bind(dev, intf);
        if (status < 0)
                return status;

        status = usbnet_get_ethernet_addr(dev, info->ether->iMACAddress);
        if (status < 0) {
                usb_set_intfdata(info->data, NULL);
                usb_driver_release_interface(driver_of(intf), info->data);
                return status;
        }

        /* FIXME cdc-ether has some multicast code too, though it complains
         * in routine cases.  info->ether describes the multicast support.
         * Implement that here, manipulating the cdc filter as needed.
         */
        return 0;
}
EXPORT_SYMBOL_GPL(usbnet_cdc_bind);

static int cdc_manage_power(struct usbnet *dev, int on)
{
        dev->intf->needs_remote_wakeup = on;
        return 0;
}

static const struct driver_info cdc_info = {
        .description =  "CDC Ethernet Device",
        .flags =        FLAG_ETHER | FLAG_POINTTOPOINT,
        // .check_connect = cdc_check_connect,
        .bind =         usbnet_cdc_bind,
        .unbind =       usbnet_cdc_unbind,
        .status =       usbnet_cdc_status,
        .manage_power = cdc_manage_power,
};

static const struct driver_info wwan_info = {
        .description =  "Mobile Broadband Network Device",
        .flags =        FLAG_WWAN,
        .bind =         usbnet_cdc_bind,
        .unbind =       usbnet_cdc_unbind,
        .status =       usbnet_cdc_status,
        .manage_power = cdc_manage_power,
};

/*-------------------------------------------------------------------------*/

#define HUAWEI_VENDOR_ID        0x12D1

static const struct usb_device_id       products [] = {
/*
 * BLACKLIST !!
 *
 * First blacklist any products that are egregiously nonconformant
 * with the CDC Ethernet specs.  Minor braindamage we cope with; when
 * they're not even trying, needing a separate driver is only the first
 * of the differences to show up.
 */

#define ZAURUS_MASTER_INTERFACE \
        .bInterfaceClass        = USB_CLASS_COMM, \
        .bInterfaceSubClass     = USB_CDC_SUBCLASS_ETHERNET, \
        .bInterfaceProtocol     = USB_CDC_PROTO_NONE

/* SA-1100 based Sharp Zaurus ("collie"), or compatible;
 * wire-incompatible with true CDC Ethernet implementations.
 * (And, it seems, needlessly so...)
 */
{
        .match_flags    =   USB_DEVICE_ID_MATCH_INT_INFO
                          | USB_DEVICE_ID_MATCH_DEVICE,
        .idVendor               = 0x04DD,
        .idProduct              = 0x8004,
        ZAURUS_MASTER_INTERFACE,
        .driver_info            = 0,
},

/* PXA-25x based Sharp Zaurii.  Note that it seems some of these
 * (later models especially) may have shipped only with firmware
 * advertising false "CDC MDLM" compatibility ... but we're not
 * clear which models did that, so for now let's assume the worst.
 */
{
        .match_flags    =   USB_DEVICE_ID_MATCH_INT_INFO
                          | USB_DEVICE_ID_MATCH_DEVICE,
        .idVendor               = 0x04DD,
        .idProduct              = 0x8005,       /* A-300 */
        ZAURUS_MASTER_INTERFACE,
        .driver_info            = 0,
}, {
        .match_flags    =   USB_DEVICE_ID_MATCH_INT_INFO
                          | USB_DEVICE_ID_MATCH_DEVICE,
        .idVendor               = 0x04DD,
        .idProduct              = 0x8006,       /* B-500/SL-5600 */
        ZAURUS_MASTER_INTERFACE,
        .driver_info            = 0,
}, {
        .match_flags    =   USB_DEVICE_ID_MATCH_INT_INFO
                  | USB_DEVICE_ID_MATCH_DEVICE,
        .idVendor               = 0x04DD,
        .idProduct              = 0x8007,       /* C-700 */
        ZAURUS_MASTER_INTERFACE,
        .driver_info            = 0,
}, {
        .match_flags    =   USB_DEVICE_ID_MATCH_INT_INFO
                 | USB_DEVICE_ID_MATCH_DEVICE,
        .idVendor               = 0x04DD,
        .idProduct              = 0x9031,       /* C-750 C-760 */
        ZAURUS_MASTER_INTERFACE,
        .driver_info            = 0,
}, {
        .match_flags    =   USB_DEVICE_ID_MATCH_INT_INFO
                 | USB_DEVICE_ID_MATCH_DEVICE,
        .idVendor               = 0x04DD,
        .idProduct              = 0x9032,       /* SL-6000 */
        ZAURUS_MASTER_INTERFACE,
        .driver_info            = 0,
}, {
        .match_flags    =   USB_DEVICE_ID_MATCH_INT_INFO
                 | USB_DEVICE_ID_MATCH_DEVICE,
        .idVendor               = 0x04DD,
        /* reported with some C860 units */
        .idProduct              = 0x9050,       /* C-860 */
        ZAURUS_MASTER_INTERFACE,
        .driver_info            = 0,
},

/* Olympus has some models with a Zaurus-compatible option.
 * R-1000 uses a FreeScale i.MXL cpu (ARMv4T)
 */
{
        .match_flags    =   USB_DEVICE_ID_MATCH_INT_INFO
                 | USB_DEVICE_ID_MATCH_DEVICE,
        .idVendor               = 0x07B4,
        .idProduct              = 0x0F02,       /* R-1000 */
        ZAURUS_MASTER_INTERFACE,
        .driver_info            = 0,
},

/* LG Electronics VL600 wants additional headers on every frame */
{
        USB_DEVICE_AND_INTERFACE_INFO(0x1004, 0x61aa, USB_CLASS_COMM,
                        USB_CDC_SUBCLASS_ETHERNET, USB_CDC_PROTO_NONE),
        .driver_info = (unsigned long)&wwan_info,
},

/*
 * WHITELIST!!!
 *
 * CDC Ether uses two interfaces, not necessarily consecutive.
 * We match the main interface, ignoring the optional device
 * class so we could handle devices that aren't exclusively
 * CDC ether.
 *
 * NOTE:  this match must come AFTER entries blacklisting devices
 * because of bugs/quirks in a given product (like Zaurus, above).
 */
{
        USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ETHERNET,
                        USB_CDC_PROTO_NONE),
        .driver_info = (unsigned long) &cdc_info,
}, {
        USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_MDLM,
                        USB_CDC_PROTO_NONE),
        .driver_info = (unsigned long)&wwan_info,

}, {
        /* Various Huawei modems with a network port like the UMG1831 */
        .match_flags    =   USB_DEVICE_ID_MATCH_VENDOR
                 | USB_DEVICE_ID_MATCH_INT_INFO,
        .idVendor               = HUAWEI_VENDOR_ID,
        .bInterfaceClass        = USB_CLASS_COMM,
        .bInterfaceSubClass     = USB_CDC_SUBCLASS_ETHERNET,
        .bInterfaceProtocol     = 255,
        .driver_info = (unsigned long)&wwan_info,
},
        { },            // END
};
MODULE_DEVICE_TABLE(usb, products);

static struct usb_driver cdc_driver = {
        .name =         "cdc_ether",
        .id_table =     products,
        .probe =        usbnet_probe,
        .disconnect =   usbnet_disconnect,
        .suspend =      usbnet_suspend,
        .resume =       usbnet_resume,
        .reset_resume = usbnet_resume,
        .supports_autosuspend = 1,
};


static int __init cdc_init(void)
{
        BUILD_BUG_ON((sizeof(((struct usbnet *)0)->data)
                        < sizeof(struct cdc_state)));

        return usb_register(&cdc_driver);
}
module_init(cdc_init);

static void __exit cdc_exit(void)
{
        usb_deregister(&cdc_driver);
}
module_exit(cdc_exit);

MODULE_AUTHOR("David Brownell");
MODULE_DESCRIPTION("USB CDC Ethernet devices");
MODULE_LICENSE("GPL");