/*      $NetBSD: if_cdce.c,v 1.4 2004/10/24 12:50:54 augustss Exp $ */

/*-
 * Copyright (c) 1997, 1998, 1999, 2000-2003 Bill Paul <wpaul@windriver.com>
 * Copyright (c) 2003-2005 Craig Boston
 * Copyright (c) 2004 Daniel Hartmeier
 * Copyright (c) 2009 Hans Petter Selasky
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Bill Paul.
 * 4. Neither the name of the author nor the names of any co-contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL Bill Paul, THE VOICES IN HIS HEAD OR
 * THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * USB Communication Device Class (Ethernet Networking Control Model)
 * http://www.usb.org/developers/devclass_docs/usbcdc11.pdf
 */

/*
 * USB Network Control Model (NCM)
 * http://www.usb.org/developers/devclass_docs/NCM10.zip
 */

#include <sys/cdefs.h>

#include <sys/stdint.h>
#include <sys/param.h>
#include <sys/queue.h>
#include <sys/types.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/bus.h>
#include <sys/module.h>
#include <sys/lock.h>
#include <sys/condvar.h>
#include <sys/sysctl.h>
#include <sys/unistd.h>
#include <sys/callout.h>
#include <sys/malloc.h>
#include <sys/caps.h>

#include <net/if.h>
#include <net/if_var.h>
#include <net/ifq_var.h>

#include <bus/u4b/usb.h>
#include <bus/u4b/usbdi.h>
#include <bus/u4b/usbdi_util.h>
#include <bus/u4b/usb_cdc.h>
#include "usbdevs.h"

#define USB_DEBUG_VAR cdce_debug
#include <bus/u4b/usb_debug.h>
#include <bus/u4b/usb_process.h>
#include <bus/u4b/usb_msctest.h>
#include "usb_if.h"

#include <bus/u4b/net/usb_ethernet.h>
#include <bus/u4b/net/if_cdcereg.h>

static device_probe_t cdce_probe;
static device_attach_t cdce_attach;
static device_detach_t cdce_detach;
static device_suspend_t cdce_suspend;
static device_resume_t cdce_resume;
static usb_handle_request_t cdce_handle_request;

static usb_callback_t cdce_bulk_write_callback;
static usb_callback_t cdce_bulk_read_callback;
static usb_callback_t cdce_intr_read_callback;
static usb_callback_t cdce_intr_write_callback;

#if CDCE_HAVE_NCM
static usb_callback_t cdce_ncm_bulk_write_callback;
static usb_callback_t cdce_ncm_bulk_read_callback;
#endif

static uether_fn_t cdce_attach_post;
static uether_fn_t cdce_init;
static uether_fn_t cdce_stop;
static uether_fn_t cdce_start;
static uether_fn_t cdce_setmulti;
static uether_fn_t cdce_setpromisc;

static uint32_t cdce_m_crc32(struct mbuf *, uint32_t, uint32_t);

#ifdef USB_DEBUG
static int cdce_debug = 0;
static int cdce_tx_interval = 0;

static SYSCTL_NODE(_hw_usb, OID_AUTO, cdce, CTLFLAG_RW, 0, "USB CDC-Ethernet");
SYSCTL_INT(_hw_usb_cdce, OID_AUTO, debug, CTLFLAG_RW, &cdce_debug, 0,
    "Debug level");
SYSCTL_INT(_hw_usb_cdce, OID_AUTO, interval, CTLFLAG_RW, &cdce_tx_interval, 0,
    "NCM transmit interval in ms");
#endif

static const struct usb_config cdce_config[CDCE_N_TRANSFER] = {

        [CDCE_BULK_RX] = {
                .type = UE_BULK,
                .endpoint = UE_ADDR_ANY,
                .direction = UE_DIR_RX,
                .if_index = 0,
                .frames = CDCE_FRAMES_MAX,
                .bufsize = (CDCE_FRAMES_MAX * MCLBYTES),
                .flags = {.pipe_bof = 1,.short_frames_ok = 1,.short_xfer_ok = 1,.ext_buffer = 1,},
                .callback = cdce_bulk_read_callback,
                .timeout = 0,   /* no timeout */
                .usb_mode = USB_MODE_DUAL,      /* both modes */
        },

        [CDCE_BULK_TX] = {
                .type = UE_BULK,
                .endpoint = UE_ADDR_ANY,
                .direction = UE_DIR_TX,
                .if_index = 0,
                .frames = CDCE_FRAMES_MAX,
                .bufsize = (CDCE_FRAMES_MAX * MCLBYTES),
                .flags = {.pipe_bof = 1,.force_short_xfer = 1,.ext_buffer = 1,},
                .callback = cdce_bulk_write_callback,
                .timeout = 10000,       /* 10 seconds */
                .usb_mode = USB_MODE_DUAL,      /* both modes */
        },

        [CDCE_INTR_RX] = {
                .type = UE_INTERRUPT,
                .endpoint = UE_ADDR_ANY,
                .direction = UE_DIR_RX,
                .if_index = 1,
                .bufsize = CDCE_IND_SIZE_MAX,
                .flags = {.pipe_bof = 1,.short_xfer_ok = 1,.no_pipe_ok = 1,},
                .callback = cdce_intr_read_callback,
                .timeout = 0,
                .usb_mode = USB_MODE_HOST,
        },

        [CDCE_INTR_TX] = {
                .type = UE_INTERRUPT,
                .endpoint = UE_ADDR_ANY,
                .direction = UE_DIR_TX,
                .if_index = 1,
                .bufsize = CDCE_IND_SIZE_MAX,
                .flags = {.pipe_bof = 1,.force_short_xfer = 1,.no_pipe_ok = 1,},
                .callback = cdce_intr_write_callback,
                .timeout = 10000,       /* 10 seconds */
                .usb_mode = USB_MODE_DEVICE,
        },
};

#if CDCE_HAVE_NCM
static const struct usb_config cdce_ncm_config[CDCE_N_TRANSFER] = {

        [CDCE_BULK_RX] = {
                .type = UE_BULK,
                .endpoint = UE_ADDR_ANY,
                .direction = UE_DIR_RX,
                .if_index = 0,
                .frames = CDCE_NCM_RX_FRAMES_MAX,
                .bufsize = (CDCE_NCM_RX_FRAMES_MAX * CDCE_NCM_RX_MAXLEN),
                .flags = {.pipe_bof = 1,.short_frames_ok = 1,.short_xfer_ok = 1,},
                .callback = cdce_ncm_bulk_read_callback,
                .timeout = 0,   /* no timeout */
                .usb_mode = USB_MODE_DUAL,      /* both modes */
        },

        [CDCE_BULK_TX] = {
                .type = UE_BULK,
                .endpoint = UE_ADDR_ANY,
                .direction = UE_DIR_TX,
                .if_index = 0,
                .frames = CDCE_NCM_TX_FRAMES_MAX,
                .bufsize = (CDCE_NCM_TX_FRAMES_MAX * CDCE_NCM_TX_MAXLEN),
                .flags = {.pipe_bof = 1,},
                .callback = cdce_ncm_bulk_write_callback,
                .timeout = 10000,       /* 10 seconds */
                .usb_mode = USB_MODE_DUAL,      /* both modes */
        },

        [CDCE_INTR_RX] = {
                .type = UE_INTERRUPT,
                .endpoint = UE_ADDR_ANY,
                .direction = UE_DIR_RX,
                .if_index = 1,
                .bufsize = CDCE_IND_SIZE_MAX,
                .flags = {.pipe_bof = 1,.short_xfer_ok = 1,.no_pipe_ok = 1,},
                .callback = cdce_intr_read_callback,
                .timeout = 0,
                .usb_mode = USB_MODE_HOST,
        },

        [CDCE_INTR_TX] = {
                .type = UE_INTERRUPT,
                .endpoint = UE_ADDR_ANY,
                .direction = UE_DIR_TX,
                .if_index = 1,
                .bufsize = CDCE_IND_SIZE_MAX,
                .flags = {.pipe_bof = 1,.force_short_xfer = 1,.no_pipe_ok = 1,},
                .callback = cdce_intr_write_callback,
                .timeout = 10000,       /* 10 seconds */
                .usb_mode = USB_MODE_DEVICE,
        },
};
#endif

static device_method_t cdce_methods[] = {
        /* USB interface */
        DEVMETHOD(usb_handle_request, cdce_handle_request),

        /* Device interface */
        DEVMETHOD(device_probe, cdce_probe),
        DEVMETHOD(device_attach, cdce_attach),
        DEVMETHOD(device_detach, cdce_detach),
        DEVMETHOD(device_suspend, cdce_suspend),
        DEVMETHOD(device_resume, cdce_resume),

        DEVMETHOD_END
};

static driver_t cdce_driver = {
        .name = "cdce",
        .methods = cdce_methods,
        .size = sizeof(struct cdce_softc),
};

static devclass_t cdce_devclass;
static eventhandler_tag cdce_etag;

static int cdce_driver_loaded(struct module *, int, void *);

DRIVER_MODULE(cdce, uhub, cdce_driver, cdce_devclass, cdce_driver_loaded, NULL);
MODULE_VERSION(cdce, 1);
MODULE_DEPEND(cdce, uether, 1, 1, 1);
MODULE_DEPEND(cdce, usb, 1, 1, 1);
MODULE_DEPEND(cdce, ether, 1, 1, 1);

static const struct usb_ether_methods cdce_ue_methods = {
        .ue_attach_post = cdce_attach_post,
        .ue_start = cdce_start,
        .ue_init = cdce_init,
        .ue_stop = cdce_stop,
        .ue_setmulti = cdce_setmulti,
        .ue_setpromisc = cdce_setpromisc,
};


static const STRUCT_USB_HOST_ID cdce_switch_devs[] = {
    {USB_VPI(USB_VENDOR_HUAWEI, USB_PRODUCT_HUAWEI_E3272_INIT, MSC_EJECT_HUAWEI2)},
};

static const STRUCT_USB_HOST_ID cdce_host_devs[] = {
        {USB_VPI(USB_VENDOR_ACERLABS, USB_PRODUCT_ACERLABS_M5632, CDCE_FLAG_NO_UNION)},
        {USB_VPI(USB_VENDOR_AMBIT, USB_PRODUCT_AMBIT_NTL_250, CDCE_FLAG_NO_UNION)},
        {USB_VPI(USB_VENDOR_COMPAQ, USB_PRODUCT_COMPAQ_IPAQLINUX, CDCE_FLAG_NO_UNION)},
        {USB_VPI(USB_VENDOR_GMATE, USB_PRODUCT_GMATE_YP3X00, CDCE_FLAG_NO_UNION)},
        {USB_VPI(USB_VENDOR_MOTOROLA2, USB_PRODUCT_MOTOROLA2_USBLAN, CDCE_FLAG_ZAURUS | CDCE_FLAG_NO_UNION)},
        {USB_VPI(USB_VENDOR_MOTOROLA2, USB_PRODUCT_MOTOROLA2_USBLAN2, CDCE_FLAG_ZAURUS | CDCE_FLAG_NO_UNION)},
        {USB_VPI(USB_VENDOR_NETCHIP, USB_PRODUCT_NETCHIP_ETHERNETGADGET, CDCE_FLAG_NO_UNION)},
        {USB_VPI(USB_VENDOR_PROLIFIC, USB_PRODUCT_PROLIFIC_PL2501, CDCE_FLAG_NO_UNION)},
        {USB_VPI(USB_VENDOR_SHARP, USB_PRODUCT_SHARP_SL5500, CDCE_FLAG_ZAURUS)},
        {USB_VPI(USB_VENDOR_SHARP, USB_PRODUCT_SHARP_SL5600, CDCE_FLAG_ZAURUS | CDCE_FLAG_NO_UNION)},
        {USB_VPI(USB_VENDOR_SHARP, USB_PRODUCT_SHARP_SLA300, CDCE_FLAG_ZAURUS | CDCE_FLAG_NO_UNION)},
        {USB_VPI(USB_VENDOR_SHARP, USB_PRODUCT_SHARP_SLC700, CDCE_FLAG_ZAURUS | CDCE_FLAG_NO_UNION)},
        {USB_VPI(USB_VENDOR_SHARP, USB_PRODUCT_SHARP_SLC750, CDCE_FLAG_ZAURUS | CDCE_FLAG_NO_UNION)},

        {USB_VENDOR(USB_VENDOR_HUAWEI), USB_IFACE_CLASS(UICLASS_VENDOR),
   USB_IFACE_SUBCLASS(0x02), USB_IFACE_PROTOCOL(0x16),
   USB_DRIVER_INFO(0)},
        {USB_VENDOR(USB_VENDOR_HUAWEI), USB_IFACE_CLASS(UICLASS_VENDOR),
   USB_IFACE_SUBCLASS(0x02), USB_IFACE_PROTOCOL(0x46),
   USB_DRIVER_INFO(0)},
        {USB_VENDOR(USB_VENDOR_HUAWEI), USB_IFACE_CLASS(UICLASS_VENDOR),
   USB_IFACE_SUBCLASS(0x02), USB_IFACE_PROTOCOL(0x76),
   USB_DRIVER_INFO(0)},
        {USB_VENDOR(USB_VENDOR_HUAWEI), USB_IFACE_CLASS(UICLASS_VENDOR),
   USB_IFACE_SUBCLASS(0x03), USB_IFACE_PROTOCOL(0x16),
   USB_DRIVER_INFO(0)},

};

static const STRUCT_USB_DUAL_ID cdce_dual_devs[] = {
        {USB_IF_CSI(UICLASS_CDC, UISUBCLASS_ETHERNET_NETWORKING_CONTROL_MODEL, 0)},
        {USB_IF_CSI(UICLASS_CDC, UISUBCLASS_MOBILE_DIRECT_LINE_MODEL, 0)},
        {USB_IF_CSI(UICLASS_CDC, UISUBCLASS_NETWORK_CONTROL_MODEL, 0)},
};

#if CDCE_HAVE_NCM
/*------------------------------------------------------------------------*
 *      cdce_ncm_init
 *
 * Return values:
 * 0: Success
 * Else: Failure
 *------------------------------------------------------------------------*/
static uint8_t
cdce_ncm_init(struct cdce_softc *sc)
{
        struct usb_ncm_parameters temp;
        struct usb_device_request req;
        struct usb_ncm_func_descriptor *ufd;
        uint8_t value[8];
        int err;

        ufd = usbd_find_descriptor(sc->sc_ue.ue_udev, NULL,
            sc->sc_ifaces_index[1], UDESC_CS_INTERFACE, 0 - 1,
            UCDC_NCM_FUNC_DESC_SUBTYPE, 0 - 1);

        /* verify length of NCM functional descriptor */
        if (ufd != NULL) {
                if (ufd->bLength < sizeof(*ufd))
                        ufd = NULL;
                else
                        DPRINTFN(1, "Found NCM functional descriptor.\n");
        }

        req.bmRequestType = UT_READ_CLASS_INTERFACE;
        req.bRequest = UCDC_NCM_GET_NTB_PARAMETERS;
        USETW(req.wValue, 0);
        req.wIndex[0] = sc->sc_ifaces_index[1];
        req.wIndex[1] = 0;
        USETW(req.wLength, sizeof(temp));

        err = usbd_do_request_flags(sc->sc_ue.ue_udev, NULL, &req,
            &temp, 0, NULL, 1000 /* ms */);
        if (err)
                return (1);

        /* Read correct set of parameters according to device mode */

        if (usbd_get_mode(sc->sc_ue.ue_udev) == USB_MODE_HOST) {
                sc->sc_ncm.rx_max = UGETDW(temp.dwNtbInMaxSize);
                sc->sc_ncm.tx_max = UGETDW(temp.dwNtbOutMaxSize);
                sc->sc_ncm.tx_remainder = UGETW(temp.wNdpOutPayloadRemainder);
                sc->sc_ncm.tx_modulus = UGETW(temp.wNdpOutDivisor);
                sc->sc_ncm.tx_struct_align = UGETW(temp.wNdpOutAlignment);
                sc->sc_ncm.tx_nframe = UGETW(temp.wNtbOutMaxDatagrams);
        } else {
                sc->sc_ncm.rx_max = UGETDW(temp.dwNtbOutMaxSize);
                sc->sc_ncm.tx_max = UGETDW(temp.dwNtbInMaxSize);
                sc->sc_ncm.tx_remainder = UGETW(temp.wNdpInPayloadRemainder);
                sc->sc_ncm.tx_modulus = UGETW(temp.wNdpInDivisor);
                sc->sc_ncm.tx_struct_align = UGETW(temp.wNdpInAlignment);
                sc->sc_ncm.tx_nframe = UGETW(temp.wNtbOutMaxDatagrams);
        }

        /* Verify maximum receive length */

        if ((sc->sc_ncm.rx_max < 32) ||
            (sc->sc_ncm.rx_max > CDCE_NCM_RX_MAXLEN)) {
                DPRINTFN(1, "Using default maximum receive length\n");
                sc->sc_ncm.rx_max = CDCE_NCM_RX_MAXLEN;
        }

        /* Verify maximum transmit length */

        if ((sc->sc_ncm.tx_max < 32) ||
            (sc->sc_ncm.tx_max > CDCE_NCM_TX_MAXLEN)) {
                DPRINTFN(1, "Using default maximum transmit length\n");
                sc->sc_ncm.tx_max = CDCE_NCM_TX_MAXLEN;
        }

        /*
         * Verify that the structure alignment is:
         * - power of two
         * - not greater than the maximum transmit length
         * - not less than four bytes
         */
        if ((sc->sc_ncm.tx_struct_align < 4) ||
            (sc->sc_ncm.tx_struct_align !=
             ((-sc->sc_ncm.tx_struct_align) & sc->sc_ncm.tx_struct_align)) ||
            (sc->sc_ncm.tx_struct_align >= sc->sc_ncm.tx_max)) {
                DPRINTFN(1, "Using default other alignment: 4 bytes\n");
                sc->sc_ncm.tx_struct_align = 4;
        }

        /*
         * Verify that the payload alignment is:
         * - power of two
         * - not greater than the maximum transmit length
         * - not less than four bytes
         */
        if ((sc->sc_ncm.tx_modulus < 4) ||
            (sc->sc_ncm.tx_modulus !=
             ((-sc->sc_ncm.tx_modulus) & sc->sc_ncm.tx_modulus)) ||
            (sc->sc_ncm.tx_modulus >= sc->sc_ncm.tx_max)) {
                DPRINTFN(1, "Using default transmit modulus: 4 bytes\n");
                sc->sc_ncm.tx_modulus = 4;
        }

        /* Verify that the payload remainder */

        if ((sc->sc_ncm.tx_remainder >= sc->sc_ncm.tx_modulus)) {
                DPRINTFN(1, "Using default transmit remainder: 0 bytes\n");
                sc->sc_ncm.tx_remainder = 0;
        }

        /*
         * Offset the TX remainder so that IP packet payload starts at
         * the tx_modulus. This is not too clear in the specification.
         */

        sc->sc_ncm.tx_remainder =
            (sc->sc_ncm.tx_remainder - ETHER_HDR_LEN) &
            (sc->sc_ncm.tx_modulus - 1);

        /* Verify max datagrams */

        if (sc->sc_ncm.tx_nframe == 0 ||
            sc->sc_ncm.tx_nframe > (CDCE_NCM_SUBFRAMES_MAX - 1)) {
                DPRINTFN(1, "Using default max "
                    "subframes: %u units\n", CDCE_NCM_SUBFRAMES_MAX - 1);
                /* need to reserve one entry for zero padding */
                sc->sc_ncm.tx_nframe = (CDCE_NCM_SUBFRAMES_MAX - 1);
        }

        /* Additional configuration, will fail in device side mode, which is OK. */

        req.bmRequestType = UT_WRITE_CLASS_INTERFACE;
        req.bRequest = UCDC_NCM_SET_NTB_INPUT_SIZE;
        USETW(req.wValue, 0);
        req.wIndex[0] = sc->sc_ifaces_index[1];
        req.wIndex[1] = 0;

        if (ufd != NULL &&
            (ufd->bmNetworkCapabilities & UCDC_NCM_CAP_MAX_DGRAM)) {
                USETW(req.wLength, 8);
                USETDW(value, sc->sc_ncm.rx_max);
                USETW(value + 4, (CDCE_NCM_SUBFRAMES_MAX - 1));
                USETW(value + 6, 0);
        } else {
                USETW(req.wLength, 4);
                USETDW(value, sc->sc_ncm.rx_max);
        }

        err = usbd_do_request_flags(sc->sc_ue.ue_udev, NULL, &req,
            &value, 0, NULL, 1000 /* ms */);
        if (err) {
                DPRINTFN(1, "Setting input size "
                    "to %u failed.\n", sc->sc_ncm.rx_max);
        }

        req.bmRequestType = UT_WRITE_CLASS_INTERFACE;
        req.bRequest = UCDC_NCM_SET_CRC_MODE;
        USETW(req.wValue, 0);   /* no CRC */
        req.wIndex[0] = sc->sc_ifaces_index[1];
        req.wIndex[1] = 0;
        USETW(req.wLength, 0);

        err = usbd_do_request_flags(sc->sc_ue.ue_udev, NULL, &req,
            NULL, 0, NULL, 1000 /* ms */);
        if (err) {
                DPRINTFN(1, "Setting CRC mode to off failed.\n");
        }

        req.bmRequestType = UT_WRITE_CLASS_INTERFACE;
        req.bRequest = UCDC_NCM_SET_NTB_FORMAT;
        USETW(req.wValue, 0);   /* NTB-16 */
        req.wIndex[0] = sc->sc_ifaces_index[1];
        req.wIndex[1] = 0;
        USETW(req.wLength, 0);

        err = usbd_do_request_flags(sc->sc_ue.ue_udev, NULL, &req,
            NULL, 0, NULL, 1000 /* ms */);
        if (err) {
                DPRINTFN(1, "Setting NTB format to 16-bit failed.\n");
        }

        return (0);             /* success */
}
#endif

static void
cdce_test_autoinst(void *arg, struct usb_device *udev,
    struct usb_attach_arg *uaa)
{
        struct usb_interface *iface;
        struct usb_interface_descriptor *id;

        if (uaa->dev_state != UAA_DEV_READY)
                return;

        iface = usbd_get_iface(udev, 0);
        if (iface == NULL)
                return;
        id = iface->idesc;
        if (id == NULL || id->bInterfaceClass != UICLASS_MASS)
                return;
        if (usbd_lookup_id_by_uaa(cdce_switch_devs, sizeof(cdce_switch_devs), uaa))
                return;         /* no device match */

        if (usb_msc_eject(udev, 0, USB_GET_DRIVER_INFO(uaa)) == 0) {
                /* success, mark the udev as disappearing */
                uaa->dev_state = UAA_DEV_EJECTING;
        }
}

static int
cdce_driver_loaded(struct module *mod, int what, void *arg)
{
        switch (what) {
        case MOD_LOAD:
                /* register our autoinstall handler */
                cdce_etag = EVENTHANDLER_REGISTER(usb_dev_configured,
                    cdce_test_autoinst, NULL, EVENTHANDLER_PRI_ANY);
                return (0);
        case MOD_UNLOAD:
                EVENTHANDLER_DEREGISTER(usb_dev_configured, cdce_etag);
                return (0);
        default:
                return (EOPNOTSUPP);
        }
}

static int
cdce_probe(device_t dev)
{
        struct usb_attach_arg *uaa = device_get_ivars(dev);
        int error;

        error = usbd_lookup_id_by_uaa(cdce_host_devs, sizeof(cdce_host_devs), uaa);
        if (error)
                error = usbd_lookup_id_by_uaa(cdce_dual_devs, sizeof(cdce_dual_devs), uaa);
        return (error);
}

static void
cdce_attach_post(struct usb_ether *ue)
{
        struct ifnet *ifp = uether_getifp(ue);
        ifq_set_maxlen(&ifp->if_snd, ifqmaxlen);
        ifq_set_ready(&ifp->if_snd);
}

static int
cdce_attach(device_t dev)
{
        struct cdce_softc *sc = device_get_softc(dev);
        struct usb_ether *ue = &sc->sc_ue;
        struct usb_attach_arg *uaa = device_get_ivars(dev);
        struct usb_interface *iface;
        const struct usb_cdc_union_descriptor *ud;
        const struct usb_interface_descriptor *id;
        const struct usb_cdc_ethernet_descriptor *ued;
        const struct usb_config *pcfg;
        uint32_t seed;
        int error;
        uint8_t i;
        uint8_t data_iface_no;
        char eaddr_str[5 * ETHER_ADDR_LEN];     /* approx */

        sc->sc_flags = USB_GET_DRIVER_INFO(uaa);
        sc->sc_ue.ue_udev = uaa->device;

        device_set_usb_desc(dev);

        lockinit(&sc->sc_lock, device_get_nameunit(dev), 0, 0);

        ud = usbd_find_descriptor
            (uaa->device, NULL, uaa->info.bIfaceIndex,
            UDESC_CS_INTERFACE, 0 - 1, UDESCSUB_CDC_UNION, 0 - 1);

        if ((ud == NULL) || (ud->bLength < sizeof(*ud)) ||
            (sc->sc_flags & CDCE_FLAG_NO_UNION)) {
                DPRINTFN(1, "No union descriptor!\n");
                sc->sc_ifaces_index[0] = uaa->info.bIfaceIndex;
                sc->sc_ifaces_index[1] = uaa->info.bIfaceIndex;
                goto alloc_transfers;
        }
        data_iface_no = ud->bSlaveInterface[0];

        for (i = 0;; i++) {

                iface = usbd_get_iface(uaa->device, i);

                if (iface) {

                        id = usbd_get_interface_descriptor(iface);

                        if (id && (id->bInterfaceNumber == data_iface_no)) {
                                sc->sc_ifaces_index[0] = i;
                                sc->sc_ifaces_index[1] = uaa->info.bIfaceIndex;
                                usbd_set_parent_iface(uaa->device, i, uaa->info.bIfaceIndex);
                                break;
                        }
                } else {
                        device_printf(dev, "no data interface found\n");
                        goto detach;
                }
        }

        /*
         * <quote>
         *
         *  The Data Class interface of a networking device shall have
         *  a minimum of two interface settings. The first setting
         *  (the default interface setting) includes no endpoints and
         *  therefore no networking traffic is exchanged whenever the
         *  default interface setting is selected. One or more
         *  additional interface settings are used for normal
         *  operation, and therefore each includes a pair of endpoints
         *  (one IN, and one OUT) to exchange network traffic. Select
         *  an alternate interface setting to initialize the network
         *  aspects of the device and to enable the exchange of
         *  network traffic.
         *
         * </quote>
         *
         * Some devices, most notably cable modems, include interface
         * settings that have no IN or OUT endpoint, therefore loop
         * through the list of all available interface settings
         * looking for one with both IN and OUT endpoints.
         */

alloc_transfers:

        pcfg = cdce_config;     /* Default Configuration */

        for (i = 0; i != 32; i++) {

                error = usbd_set_alt_interface_index(uaa->device,
                    sc->sc_ifaces_index[0], i);
                if (error)
                        break;
#if CDCE_HAVE_NCM
                if ((i == 0) && (cdce_ncm_init(sc) == 0))
                        pcfg = cdce_ncm_config;
#endif
                error = usbd_transfer_setup(uaa->device,
                    sc->sc_ifaces_index, sc->sc_xfer,
                    pcfg, CDCE_N_TRANSFER, sc, &sc->sc_lock);

                if (error == 0)
                        break;
        }

        if (error || (i == 32)) {
                device_printf(dev, "No valid alternate "
                    "setting found\n");
                goto detach;
        }

        ued = usbd_find_descriptor
            (uaa->device, NULL, uaa->info.bIfaceIndex,
            UDESC_CS_INTERFACE, 0 - 1, UDESCSUB_CDC_ENF, 0 - 1);

        if ((ued == NULL) || (ued->bLength < sizeof(*ued))) {
                error = USB_ERR_INVAL;
        } else {
                error = usbd_req_get_string_any(uaa->device, NULL,
                    eaddr_str, sizeof(eaddr_str), ued->iMacAddress);
        }

        if (error) {

                /* fake MAC address */

                device_printf(dev, "faking MAC address\n");
                seed = ticks;
                sc->sc_ue.ue_eaddr[0] = 0x2a;
                memcpy(&sc->sc_ue.ue_eaddr[1], &seed, sizeof(uint32_t));
                sc->sc_ue.ue_eaddr[5] = device_get_unit(dev);

        } else {

                memset(sc->sc_ue.ue_eaddr, 0, sizeof(sc->sc_ue.ue_eaddr));

                for (i = 0; i != (ETHER_ADDR_LEN * 2); i++) {

                        char c = eaddr_str[i];

                        if ('0' <= c && c <= '9')
                                c -= '0';
                        else if (c != 0)
                                c -= 'A' - 10;
                        else
                                break;

                        c &= 0xf;

                        if ((i & 1) == 0)
                                c <<= 4;
                        sc->sc_ue.ue_eaddr[i / 2] |= c;
                }

                if (uaa->usb_mode == USB_MODE_DEVICE) {
                        /*
                         * Do not use the same MAC address like the peer !
                         */
                        sc->sc_ue.ue_eaddr[5] ^= 0xFF;
                }
        }

        ue->ue_sc = sc;
        ue->ue_dev = dev;
        ue->ue_udev = uaa->device;
        ue->ue_lock = &sc->sc_lock;
        ue->ue_methods = &cdce_ue_methods;

        error = uether_ifattach(ue);
        if (error) {
                device_printf(dev, "could not attach interface\n");
                goto detach;
        }
        return (0);                     /* success */

detach:
        cdce_detach(dev);
        return (ENXIO);                 /* failure */
}

static int
cdce_detach(device_t dev)
{
        struct cdce_softc *sc = device_get_softc(dev);
        struct usb_ether *ue = &sc->sc_ue;

        /* stop all USB transfers first */
        usbd_transfer_unsetup(sc->sc_xfer, CDCE_N_TRANSFER);
        uether_ifdetach(ue);
        lockuninit(&sc->sc_lock);

        return (0);
}

static void
cdce_start(struct usb_ether *ue)
{
        struct cdce_softc *sc = uether_getsc(ue);

        /*
         * Start the USB transfers, if not already started:
         */
        usbd_transfer_start(sc->sc_xfer[CDCE_BULK_TX]);
        usbd_transfer_start(sc->sc_xfer[CDCE_BULK_RX]);
}

static void
cdce_free_queue(struct mbuf **ppm, uint8_t n)
{
        uint8_t x;
        for (x = 0; x != n; x++) {
                if (ppm[x] != NULL) {
                        m_freem(ppm[x]);
                        ppm[x] = NULL;
                }
        }
}

static void
cdce_bulk_write_callback(struct usb_xfer *xfer, usb_error_t error)
{
        struct cdce_softc *sc = usbd_xfer_softc(xfer);
        struct ifnet *ifp = uether_getifp(&sc->sc_ue);
        struct mbuf *m;
        struct mbuf *mt;
        uint32_t crc;
        uint8_t x;
        int actlen, aframes;

        usbd_xfer_status(xfer, &actlen, NULL, &aframes, NULL);

        DPRINTFN(1, "\n");

        switch (USB_GET_STATE(xfer)) {
        case USB_ST_TRANSFERRED:
                DPRINTFN(11, "transfer complete: %u bytes in %u frames\n",
                    actlen, aframes);
                ifq_clr_oactive(&ifp->if_snd);
                IFNET_STAT_INC(ifp, opackets, 1);

                /* free all previous TX buffers */
                cdce_free_queue(sc->sc_tx_buf, CDCE_FRAMES_MAX);

                /* FALLTHROUGH */
        case USB_ST_SETUP:
tr_setup:
                DPRINTFN(11, "transfer setup\n");
                if(ifq_is_oactive(&ifp->if_snd))
                        return;

                for (x = 0; x != CDCE_FRAMES_MAX; x++) {

                        m = ifq_dequeue(&ifp->if_snd);

                        if (m == NULL)
                                break;

                        if (sc->sc_flags & CDCE_FLAG_ZAURUS) {
                                /*
                                 * Zaurus wants a 32-bit CRC appended
                                 * to every frame
                                 */

                                crc = cdce_m_crc32(m, 0, m->m_pkthdr.len);
                                crc = htole32(crc);

                                if (!m_append(m, 4, &crc)) {
                                        m_freem(m);
                                        IFNET_STAT_INC(ifp, oerrors, 1);
                                        continue;
                                }
                        }
                        if (m->m_len != m->m_pkthdr.len) {
                                mt = m_defrag(m, M_NOWAIT);
                                if (mt == NULL) {
                                        m_freem(m);
                                        ifp->if_oerrors++;
                                        continue;
                                }
                                m = mt;
                        }
                        if (m->m_pkthdr.len > MCLBYTES) {
                                m->m_pkthdr.len = MCLBYTES;
                        }
                        sc->sc_tx_buf[x] = m;
                        usbd_xfer_set_frame_data(xfer, x, m->m_data, m->m_len);

                        /*
                         * If there's a BPF listener, bounce a copy of
                         * this frame to him:
                         */
                        BPF_MTAP(ifp, m);
                }
                if (x != 0) {
                        usbd_xfer_set_frames(xfer, x);
                        usbd_transfer_submit(xfer);
                        ifq_set_oactive(&ifp->if_snd);
                }
                break;

        default:                        /* Error */
                DPRINTFN(11, "transfer error, %s\n",
                    usbd_errstr(error));

                /* free all previous TX buffers */
                cdce_free_queue(sc->sc_tx_buf, CDCE_FRAMES_MAX);

                /* count output errors */
    IFNET_STAT_INC(ifp, oerrors, 1);
                ifq_clr_oactive(&ifp->if_snd);
                if (error != USB_ERR_CANCELLED) {
                        if (usbd_get_mode(sc->sc_ue.ue_udev) == USB_MODE_HOST) {
                                /* try to clear stall first */
                                usbd_xfer_set_stall(xfer);
                        }
                        goto tr_setup;
                }
                break;
        }
}

static int32_t
cdce_m_crc32_cb(void *arg, void *src, uint32_t count)
{
        uint32_t *p_crc = arg;

        *p_crc = crc32_ext(src, count, *p_crc);

        return (0);
}

static uint32_t
cdce_m_crc32(struct mbuf *m, uint32_t src_offset, uint32_t src_len)
{
        uint32_t crc = 0xFFFFFFFF;
        int error;

        error = m_apply(m, src_offset, src_len, cdce_m_crc32_cb, &crc);
        return (crc ^ 0xFFFFFFFF);
}

static void
cdce_init(struct usb_ether *ue)
{
        struct cdce_softc *sc = uether_getsc(ue);
        struct ifnet *ifp = uether_getifp(ue);

        CDCE_LOCK_ASSERT(sc, MA_OWNED);

        ifp->if_flags |= IFF_RUNNING;

        /* start interrupt transfer */
        usbd_transfer_start(sc->sc_xfer[CDCE_INTR_RX]);
        usbd_transfer_start(sc->sc_xfer[CDCE_INTR_TX]);

        /*
         * Stall data write direction, which depends on USB mode.
         *
         * Some USB host stacks (e.g. Mac OS X) don't clears stall
         * bit as it should, so set it in our host mode only.
         */
        if (usbd_get_mode(sc->sc_ue.ue_udev) == USB_MODE_HOST)
                usbd_xfer_set_stall(sc->sc_xfer[CDCE_BULK_TX]);

        /* start data transfers */
        cdce_start(ue);
}

static void
cdce_stop(struct usb_ether *ue)
{
        struct cdce_softc *sc = uether_getsc(ue);
        struct ifnet *ifp = uether_getifp(ue);

        CDCE_LOCK_ASSERT(sc, MA_OWNED);

        ifp->if_flags &= ~IFF_RUNNING;
        ifq_clr_oactive(&ifp->if_snd);

        /*
         * stop all the transfers, if not already stopped:
         */
        usbd_transfer_stop(sc->sc_xfer[CDCE_BULK_RX]);
        usbd_transfer_stop(sc->sc_xfer[CDCE_BULK_TX]);
        usbd_transfer_stop(sc->sc_xfer[CDCE_INTR_RX]);
        usbd_transfer_stop(sc->sc_xfer[CDCE_INTR_TX]);
}

static void
cdce_setmulti(struct usb_ether *ue)
{
        /* no-op */
        return;
}

static void
cdce_setpromisc(struct usb_ether *ue)
{
        /* no-op */
        return;
}

static int
cdce_suspend(device_t dev)
{
        device_printf(dev, "Suspending\n");
        return (0);
}

static int
cdce_resume(device_t dev)
{
        device_printf(dev, "Resuming\n");
        return (0);
}

static void
cdce_bulk_read_callback(struct usb_xfer *xfer, usb_error_t error)
{
        struct cdce_softc *sc = usbd_xfer_softc(xfer);
        struct mbuf *m;
        uint8_t x;
        int actlen, aframes, len;

        usbd_xfer_status(xfer, &actlen, NULL, &aframes, NULL);

        switch (USB_GET_STATE(xfer)) {
        case USB_ST_TRANSFERRED:

                DPRINTF("received %u bytes in %u frames\n", actlen, aframes);

                for (x = 0; x != aframes; x++) {

                        m = sc->sc_rx_buf[x];
                        sc->sc_rx_buf[x] = NULL;
                        len = usbd_xfer_frame_len(xfer, x);

                        /* Strip off CRC added by Zaurus, if any */
                        if ((sc->sc_flags & CDCE_FLAG_ZAURUS) && len >= 14)
                                len -= 4;

                        if (len < (int)sizeof(struct ether_header)) {
                                m_freem(m);
                                continue;
                        }
                        /* queue up mbuf */
                        uether_rxmbuf(&sc->sc_ue, m, len);
                }

                /* FALLTHROUGH */
        case USB_ST_SETUP:
                /*
                 * TODO: Implement support for multi frame transfers,
                 * when the USB hardware supports it.
                 */
                for (x = 0; x != 1; x++) {
                        if (sc->sc_rx_buf[x] == NULL) {
                                m = uether_newbuf();
                                if (m == NULL)
                                        goto tr_stall;
                                sc->sc_rx_buf[x] = m;
                        } else {
                                m = sc->sc_rx_buf[x];
                        }

                        usbd_xfer_set_frame_data(xfer, x, m->m_data, m->m_len);
                }
                /* set number of frames and start hardware */
                usbd_xfer_set_frames(xfer, x);
                usbd_transfer_submit(xfer);
                /* flush any received frames */
                uether_rxflush(&sc->sc_ue);
                break;

        default:                        /* Error */
                DPRINTF("error = %s\n",
                    usbd_errstr(error));

                if (error != USB_ERR_CANCELLED) {
tr_stall:
                        if (usbd_get_mode(sc->sc_ue.ue_udev) == USB_MODE_HOST) {
                                /* try to clear stall first */
                                usbd_xfer_set_stall(xfer);
                                usbd_xfer_set_frames(xfer, 0);
                                usbd_transfer_submit(xfer);
                        }
                        break;
                }

                /* need to free the RX-mbufs when we are cancelled */
                cdce_free_queue(sc->sc_rx_buf, CDCE_FRAMES_MAX);
                break;
        }
}

static void
cdce_intr_read_callback(struct usb_xfer *xfer, usb_error_t error)
{
        struct cdce_softc *sc = usbd_xfer_softc(xfer);
        int actlen;

        usbd_xfer_status(xfer, &actlen, NULL, NULL, NULL);

        switch (USB_GET_STATE(xfer)) {
        case USB_ST_TRANSFERRED:

                DPRINTF("Received %d bytes\n", actlen);

                /* TODO: decode some indications */

                /* FALLTHROUGH */
        case USB_ST_SETUP:
tr_setup:
                usbd_xfer_set_frame_len(xfer, 0, usbd_xfer_max_len(xfer));
                usbd_transfer_submit(xfer);
                break;

        default:                        /* Error */
                if (error != USB_ERR_CANCELLED) {
                        /* start clear stall */
                        if (usbd_get_mode(sc->sc_ue.ue_udev) == USB_MODE_HOST)
                                usbd_xfer_set_stall(xfer);
                        goto tr_setup;
                }
                break;
        }
}

static void
cdce_intr_write_callback(struct usb_xfer *xfer, usb_error_t error)
{
        struct cdce_softc *sc = usbd_xfer_softc(xfer);
        struct usb_cdc_notification req;
        struct usb_page_cache *pc;
        uint32_t speed;
        int actlen;

        usbd_xfer_status(xfer, &actlen, NULL, NULL, NULL);

        switch (USB_GET_STATE(xfer)) {
        case USB_ST_TRANSFERRED:

                DPRINTF("Transferred %d bytes\n", actlen);

                switch (sc->sc_notify_state) {
                case CDCE_NOTIFY_NETWORK_CONNECTION:
                        sc->sc_notify_state = CDCE_NOTIFY_SPEED_CHANGE;
                        break;
                case CDCE_NOTIFY_SPEED_CHANGE:
                        sc->sc_notify_state = CDCE_NOTIFY_DONE;
                        break;
                default:
                        break;
                }

                /* FALLTHROUGH */
        case USB_ST_SETUP:
tr_setup:
                /*
                 * Inform host about connection. Required according to USB CDC
                 * specification and communicating to Mac OS X USB host stack.
                 * Some of the values seems ignored by Mac OS X though.
                 */
                if (sc->sc_notify_state == CDCE_NOTIFY_NETWORK_CONNECTION) {
                        req.bmRequestType = UCDC_NOTIFICATION;
                        req.bNotification = UCDC_N_NETWORK_CONNECTION;
                        req.wIndex[0] = sc->sc_ifaces_index[1];
                        req.wIndex[1] = 0;
                        USETW(req.wValue, 1); /* Connected */
                        USETW(req.wLength, 0);

                        pc = usbd_xfer_get_frame(xfer, 0);
                        usbd_copy_in(pc, 0, &req, sizeof(req));
                        usbd_xfer_set_frame_len(xfer, 0, sizeof(req));
                        usbd_xfer_set_frames(xfer, 1);
                        usbd_transfer_submit(xfer);

                } else if (sc->sc_notify_state == CDCE_NOTIFY_SPEED_CHANGE) {
                        req.bmRequestType = UCDC_NOTIFICATION;
                        req.bNotification = UCDC_N_CONNECTION_SPEED_CHANGE;
                        req.wIndex[0] = sc->sc_ifaces_index[1];
                        req.wIndex[1] = 0;
                        USETW(req.wValue, 0);
                        USETW(req.wLength, 8);

                        /* Peak theoretical bulk trasfer rate in bits/s */
                        if (usbd_get_speed(sc->sc_ue.ue_udev) != USB_SPEED_FULL)
                                speed = (13 * 512 * 8 * 1000 * 8);
                        else
                                speed = (19 * 64 * 1 * 1000 * 8);

                        USETDW(req.data + 0, speed); /* Upstream bit rate */
                        USETDW(req.data + 4, speed); /* Downstream bit rate */

                        pc = usbd_xfer_get_frame(xfer, 0);
                        usbd_copy_in(pc, 0, &req, sizeof(req));
                        usbd_xfer_set_frame_len(xfer, 0, sizeof(req));
                        usbd_xfer_set_frames(xfer, 1);
                        usbd_transfer_submit(xfer);
                }
                break;

        default:                        /* Error */
                if (error != USB_ERR_CANCELLED) {
                        if (usbd_get_mode(sc->sc_ue.ue_udev) == USB_MODE_HOST) {
                                /* start clear stall */
                                usbd_xfer_set_stall(xfer);
                        }
                        goto tr_setup;
                }
                break;
        }
}

static int
cdce_handle_request(device_t dev,
    const void *preq, void **pptr, uint16_t *plen,
    uint16_t offset, uint8_t *pstate)
{
        struct cdce_softc *sc = device_get_softc(dev);
        const struct usb_device_request *req = preq;
        uint8_t is_complete = *pstate;

        /*
         * When Mac OS X resumes after suspending it expects
         * to be notified again after this request.
         */
        if (req->bmRequestType == UT_WRITE_CLASS_INTERFACE && \
            req->bRequest == UCDC_NCM_SET_ETHERNET_PACKET_FILTER) {

                if (is_complete == 1) {
                        CDCE_LOCK(sc);
                        sc->sc_notify_state = CDCE_NOTIFY_SPEED_CHANGE;
                        usbd_transfer_start(sc->sc_xfer[CDCE_INTR_TX]);
                        CDCE_UNLOCK(sc);
                }

                return (0);
        }

        return (ENXIO);                 /* use builtin handler */
}

#if CDCE_HAVE_NCM
static void
cdce_ncm_tx_zero(struct usb_page_cache *pc,
    uint32_t start, uint32_t end)
{
        if (start >= CDCE_NCM_TX_MAXLEN)
                return;
        if (end > CDCE_NCM_TX_MAXLEN)
                end = CDCE_NCM_TX_MAXLEN;

        usbd_frame_zero(pc, start, end - start);
}

static uint8_t
cdce_ncm_fill_tx_frames(struct usb_xfer *xfer, uint8_t index)
{
        struct cdce_softc *sc = usbd_xfer_softc(xfer);
        struct ifnet *ifp = uether_getifp(&sc->sc_ue);
        struct usb_page_cache *pc = usbd_xfer_get_frame(xfer, index);
        struct mbuf *m;
        uint32_t rem;
        uint32_t offset;
        uint32_t last_offset;
        uint16_t n;
        uint8_t retval;

        usbd_xfer_set_frame_offset(xfer, index * CDCE_NCM_TX_MAXLEN, index);

        offset = sizeof(sc->sc_ncm.hdr) +
            sizeof(sc->sc_ncm.dpt) + sizeof(sc->sc_ncm.dp);

        /* Store last valid offset before alignment */
        last_offset = offset;

        /* Align offset */
        offset = CDCE_NCM_ALIGN(sc->sc_ncm.tx_remainder,
            offset, sc->sc_ncm.tx_modulus);

        /* Zero pad */
        cdce_ncm_tx_zero(pc, last_offset, offset);

        /* buffer full */
        retval = 2;

        for (n = 0; n != sc->sc_ncm.tx_nframe; n++) {

                /* check if end of transmit buffer is reached */

                if (offset >= sc->sc_ncm.tx_max)
                        break;

                /* compute maximum buffer size */

                rem = sc->sc_ncm.tx_max - offset;

                m = ifq_dequeue(&ifp->if_snd);

                if (m == NULL) {
                        /* buffer not full */
                        retval = 1;
                        break;
                }

                if (m->m_pkthdr.len > (int)rem) {
                        if (n == 0) {
                                /* The frame won't fit in our buffer */
                                DPRINTFN(1, "Frame too big to be transmitted!\n");
                                m_freem(m);
                                ifp->if_oerrors++;
                                n--;
                                continue;
                        }
                        /* Wait till next buffer becomes ready */
                        ifq_prepend(&ifp->if_snd, m);
                        break;
                }
                usbd_m_copy_in(pc, offset, m, 0, m->m_pkthdr.len);

                USETW(sc->sc_ncm.dp[n].wFrameLength, m->m_pkthdr.len);
                USETW(sc->sc_ncm.dp[n].wFrameIndex, offset);

                /* Update offset */
                offset += m->m_pkthdr.len;

                /* Store last valid offset before alignment */
                last_offset = offset;

                /* Align offset */
                offset = CDCE_NCM_ALIGN(sc->sc_ncm.tx_remainder,
                    offset, sc->sc_ncm.tx_modulus);

                /* Zero pad */
                cdce_ncm_tx_zero(pc, last_offset, offset);

                /*
                 * If there's a BPF listener, bounce a copy
                 * of this frame to him:
                 */
                BPF_MTAP(ifp, m);

                /* Free mbuf */

                m_freem(m);

                /* Pre-increment interface counter */

                IFNET_STAT_INC(ifp, opackets, 1);
        }

        if (n == 0)
                return (0);

        rem = (sizeof(sc->sc_ncm.dpt) + (4 * n) + 4);

        USETW(sc->sc_ncm.dpt.wLength, rem);

        /* zero the rest of the data pointer entries */
        for (; n != CDCE_NCM_SUBFRAMES_MAX; n++) {
                USETW(sc->sc_ncm.dp[n].wFrameLength, 0);
                USETW(sc->sc_ncm.dp[n].wFrameIndex, 0);
        }

        offset = last_offset;

        /* Align offset */
        offset = CDCE_NCM_ALIGN(0, offset, CDCE_NCM_TX_MINLEN);

        /* Optimise, save bandwidth and force short termination */
        if (offset >= sc->sc_ncm.tx_max)
                offset = sc->sc_ncm.tx_max;
        else
                offset ++;

        /* Zero pad */
        cdce_ncm_tx_zero(pc, last_offset, offset);

        /* set frame length */
        usbd_xfer_set_frame_len(xfer, index, offset);

        /* Fill out 16-bit header */
        sc->sc_ncm.hdr.dwSignature[0] = 'N';
        sc->sc_ncm.hdr.dwSignature[1] = 'C';
        sc->sc_ncm.hdr.dwSignature[2] = 'M';
        sc->sc_ncm.hdr.dwSignature[3] = 'H';
        USETW(sc->sc_ncm.hdr.wHeaderLength, sizeof(sc->sc_ncm.hdr));
        USETW(sc->sc_ncm.hdr.wBlockLength, offset);
        USETW(sc->sc_ncm.hdr.wSequence, sc->sc_ncm.tx_seq);
        USETW(sc->sc_ncm.hdr.wDptIndex, sizeof(sc->sc_ncm.hdr));

        sc->sc_ncm.tx_seq++;

        /* Fill out 16-bit frame table header */
        sc->sc_ncm.dpt.dwSignature[0] = 'N';
        sc->sc_ncm.dpt.dwSignature[1] = 'C';
        sc->sc_ncm.dpt.dwSignature[2] = 'M';
        sc->sc_ncm.dpt.dwSignature[3] = '0';
        USETW(sc->sc_ncm.dpt.wNextNdpIndex, 0);         /* reserved */

        usbd_copy_in(pc, 0, &(sc->sc_ncm.hdr), sizeof(sc->sc_ncm.hdr));
        usbd_copy_in(pc, sizeof(sc->sc_ncm.hdr), &(sc->sc_ncm.dpt),
            sizeof(sc->sc_ncm.dpt));
        usbd_copy_in(pc, sizeof(sc->sc_ncm.hdr) + sizeof(sc->sc_ncm.dpt),
            &(sc->sc_ncm.dp), sizeof(sc->sc_ncm.dp));
        return (retval);
}

static void
cdce_ncm_bulk_write_callback(struct usb_xfer *xfer, usb_error_t error)
{
        struct cdce_softc *sc = usbd_xfer_softc(xfer);
        struct ifnet *ifp = uether_getifp(&sc->sc_ue);
        uint16_t x;
        uint8_t temp;
        int actlen;
        int aframes;

        switch (USB_GET_STATE(xfer)) {
        case USB_ST_TRANSFERRED:

                usbd_xfer_status(xfer, &actlen, NULL, &aframes, NULL);

                DPRINTFN(10, "transfer complete: "
                    "%u bytes in %u frames\n", actlen, aframes);

        case USB_ST_SETUP:
                for (x = 0; x != CDCE_NCM_TX_FRAMES_MAX; x++) {
                        temp = cdce_ncm_fill_tx_frames(xfer, x);
                        if (temp == 0)
                                break;
                        if (temp == 1) {
                                x++;
                                break;
                        }
                }

                if (x != 0) {
#ifdef USB_DEBUG
                        usbd_xfer_set_interval(xfer, cdce_tx_interval);
#endif
                        usbd_xfer_set_frames(xfer, x);
                        usbd_transfer_submit(xfer);
                }
                break;

        default:                        /* Error */
                DPRINTFN(10, "Transfer error: %s\n",
                    usbd_errstr(error));

                /* update error counter */
                ifp->if_oerrors += 1;

                if (error != USB_ERR_CANCELLED) {
                        if (usbd_get_mode(sc->sc_ue.ue_udev) == USB_MODE_HOST) {
                                /* try to clear stall first */
                                usbd_xfer_set_stall(xfer);
                                usbd_xfer_set_frames(xfer, 0);
                                usbd_transfer_submit(xfer);
                        }
                }
                break;
        }
}

static void
cdce_ncm_bulk_read_callback(struct usb_xfer *xfer, usb_error_t error)
{
        struct cdce_softc *sc = usbd_xfer_softc(xfer);
        struct usb_page_cache *pc = usbd_xfer_get_frame(xfer, 0);
        struct ifnet *ifp = uether_getifp(&sc->sc_ue);
        struct mbuf *m;
        int sumdata;
        int sumlen;
        int actlen;
        int aframes;
        int temp;
        int nframes;
        int x;
        int offset;

        switch (USB_GET_STATE(xfer)) {
        case USB_ST_TRANSFERRED:

                usbd_xfer_status(xfer, &actlen, &sumlen, &aframes, NULL);

                DPRINTFN(1, "received %u bytes in %u frames\n",
                    actlen, aframes);

                if (actlen < (int)(sizeof(sc->sc_ncm.hdr) +
                    sizeof(sc->sc_ncm.dpt))) {
                        DPRINTFN(1, "frame too short\n");
                        goto tr_setup;
                }
                usbd_copy_out(pc, 0, &(sc->sc_ncm.hdr),
                    sizeof(sc->sc_ncm.hdr));

                if ((sc->sc_ncm.hdr.dwSignature[0] != 'N') ||
                    (sc->sc_ncm.hdr.dwSignature[1] != 'C') ||
                    (sc->sc_ncm.hdr.dwSignature[2] != 'M') ||
                    (sc->sc_ncm.hdr.dwSignature[3] != 'H')) {
                        DPRINTFN(1, "invalid HDR signature: "
                            "0x%02x:0x%02x:0x%02x:0x%02x\n",
                            sc->sc_ncm.hdr.dwSignature[0],
                            sc->sc_ncm.hdr.dwSignature[1],
                            sc->sc_ncm.hdr.dwSignature[2],
                            sc->sc_ncm.hdr.dwSignature[3]);
                        goto tr_stall;
                }
                temp = UGETW(sc->sc_ncm.hdr.wBlockLength);
                if (temp > sumlen) {
                        DPRINTFN(1, "unsupported block length %u/%u\n",
                            temp, sumlen);
                        goto tr_stall;
                }
                temp = UGETW(sc->sc_ncm.hdr.wDptIndex);
                if ((int)(temp + sizeof(sc->sc_ncm.dpt)) > actlen) {
                        DPRINTFN(1, "invalid DPT index: 0x%04x\n", temp);
                        goto tr_stall;
                }
                usbd_copy_out(pc, temp, &(sc->sc_ncm.dpt),
                    sizeof(sc->sc_ncm.dpt));

                if ((sc->sc_ncm.dpt.dwSignature[0] != 'N') ||
                    (sc->sc_ncm.dpt.dwSignature[1] != 'C') ||
                    (sc->sc_ncm.dpt.dwSignature[2] != 'M') ||
                    (sc->sc_ncm.dpt.dwSignature[3] != '0')) {
                        DPRINTFN(1, "invalid DPT signature"
                            "0x%02x:0x%02x:0x%02x:0x%02x\n",
                            sc->sc_ncm.dpt.dwSignature[0],
                            sc->sc_ncm.dpt.dwSignature[1],
                            sc->sc_ncm.dpt.dwSignature[2],
                            sc->sc_ncm.dpt.dwSignature[3]);
                        goto tr_stall;
                }
                nframes = UGETW(sc->sc_ncm.dpt.wLength) / 4;

                /* Subtract size of header and last zero padded entry */
                if (nframes >= (2 + 1))
                        nframes -= (2 + 1);
                else
                        nframes = 0;

                DPRINTFN(1, "nframes = %u\n", nframes);

                temp += sizeof(sc->sc_ncm.dpt);

                if ((temp + (4 * nframes)) > actlen)
                        goto tr_stall;

                if (nframes > CDCE_NCM_SUBFRAMES_MAX) {
                        DPRINTFN(1, "Truncating number of frames from %u to %u\n",
                            nframes, CDCE_NCM_SUBFRAMES_MAX);
                        nframes = CDCE_NCM_SUBFRAMES_MAX;
                }
                usbd_copy_out(pc, temp, &(sc->sc_ncm.dp), (4 * nframes));

                sumdata = 0;

                for (x = 0; x != nframes; x++) {

                        offset = UGETW(sc->sc_ncm.dp[x].wFrameIndex);
                        temp = UGETW(sc->sc_ncm.dp[x].wFrameLength);

                        if ((offset == 0) ||
                            (temp < (int)sizeof(struct ether_header)) ||
                            (temp > (MCLBYTES - ETHER_ALIGN))) {
                                DPRINTFN(1, "NULL frame detected at %d\n", x);
                                m = NULL;
                                /* silently ignore this frame */
                                continue;
                        } else if ((offset + temp) > actlen) {
                                DPRINTFN(1, "invalid frame "
                                    "detected at %d\n", x);
                                m = NULL;
                                /* silently ignore this frame */
                                continue;
                        } else if (temp > (int)(MHLEN - ETHER_ALIGN)) {
                                m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
                        } else {
                                m = m_gethdr(M_NOWAIT, MT_DATA);
                        }

                        DPRINTFN(16, "frame %u, offset = %u, length = %u \n",
                            x, offset, temp);

                        /* check if we have a buffer */
                        if (m) {
                                m->m_len = m->m_pkthdr.len = temp + ETHER_ALIGN;
                                m_adj(m, ETHER_ALIGN);

                                usbd_copy_out(pc, offset, m->m_data, temp);

                                /* enqueue */
                                uether_rxmbuf(&sc->sc_ue, m, temp);

                                sumdata += temp;
                        } else {
                                ifp->if_ierrors++;
                        }
                }

                DPRINTFN(1, "Efficiency: %u/%u bytes\n", sumdata, actlen);

        case USB_ST_SETUP:
tr_setup:
                usbd_xfer_set_frame_len(xfer, 0, sc->sc_ncm.rx_max);
                usbd_xfer_set_frames(xfer, 1);
                usbd_transfer_submit(xfer);
                uether_rxflush(&sc->sc_ue);     /* must be last */
                break;

        default:                        /* Error */
                DPRINTFN(1, "error = %s\n",
                    usbd_errstr(error));

                if (error != USB_ERR_CANCELLED) {
tr_stall:
                        if (usbd_get_mode(sc->sc_ue.ue_udev) == USB_MODE_HOST) {
                                /* try to clear stall first */
                                usbd_xfer_set_stall(xfer);
                                usbd_xfer_set_frames(xfer, 0);
                                usbd_transfer_submit(xfer);
                        }
                }
                break;
        }
}
#endif