/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2010 Hans Petter Selasky. All rights reserved.
 * Copyright (c) 2009 Diego Giagio. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 THE AUTHOR OR 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.
 */

/*
 * Thanks to Diego Giagio for figuring out the programming details for
 * the Apple iPhone Ethernet driver.
 */

#include <sys/stdint.h>
#include <sys/stddef.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/mutex.h>
#include <sys/condvar.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <sys/sx.h>
#include <sys/unistd.h>
#include <sys/callout.h>
#include <sys/malloc.h>
#include <sys/priv.h>

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

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

#define USB_DEBUG_VAR ipheth_debug
#include <dev/usb/usb_debug.h>
#include <dev/usb/usb_process.h>

#include <dev/usb/net/usb_ethernet.h>
#include <dev/usb/net/if_iphethvar.h>

static device_probe_t ipheth_probe;
static device_attach_t ipheth_attach;
static device_detach_t ipheth_detach;

static usb_callback_t ipheth_bulk_write_callback;
static usb_callback_t ipheth_bulk_read_callback;

static uether_fn_t ipheth_attach_post;
static uether_fn_t ipheth_tick;
static uether_fn_t ipheth_init;
static uether_fn_t ipheth_stop;
static uether_fn_t ipheth_start;
static uether_fn_t ipheth_setmulti;
static uether_fn_t ipheth_setpromisc;

static ipheth_consumer_t ipheth_consume_read;
static ipheth_consumer_t ipheth_consume_read_ncm;

#ifdef USB_DEBUG
static int ipheth_debug = 0;

static SYSCTL_NODE(_hw_usb, OID_AUTO, ipheth, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
    "USB iPhone ethernet");
SYSCTL_INT(_hw_usb_ipheth, OID_AUTO, debug, CTLFLAG_RWTUN, &ipheth_debug, 0, "Debug level");
#endif

static const struct usb_config ipheth_config[IPHETH_N_TRANSFER] = {
        [IPHETH_BULK_RX] = {
                .type = UE_BULK,
                .endpoint = UE_ADDR_ANY,
                .direction = UE_DIR_RX,
                .frames = IPHETH_RX_FRAMES_MAX,
                .bufsize = (IPHETH_RX_FRAMES_MAX * MCLBYTES),
                .flags = {.short_frames_ok = 1, .short_xfer_ok = 1, .ext_buffer = 1,},
                .callback = ipheth_bulk_read_callback,
                .timeout = 0,           /* no timeout */
        },

        [IPHETH_BULK_TX] = {
                .type = UE_BULK,
                .endpoint = UE_ADDR_ANY,
                .direction = UE_DIR_TX,
                .frames = IPHETH_TX_FRAMES_MAX,
                .bufsize = (IPHETH_TX_FRAMES_MAX * IPHETH_BUF_SIZE),
                .flags = {.force_short_xfer = 1,},
                .callback = ipheth_bulk_write_callback,
                .timeout = IPHETH_TX_TIMEOUT,
        },
};

static const struct usb_config ipheth_config_ncm[IPHETH_N_TRANSFER] = {
        [IPHETH_BULK_RX] = {
                .type = UE_BULK,
                .endpoint = UE_ADDR_ANY,
                .direction = UE_DIR_RX,
                .frames = 1,
                .bufsize = IPHETH_RX_NCM_BUF_SIZE,
                .flags = {.short_frames_ok = 1, .short_xfer_ok = 1,},
                .callback = ipheth_bulk_read_callback,
                .timeout = 0,           /* no timeout */
        },

        [IPHETH_BULK_TX] = {
                .type = UE_BULK,
                .endpoint = UE_ADDR_ANY,
                .direction = UE_DIR_TX,
                .frames = IPHETH_TX_FRAMES_MAX,
                .bufsize = (IPHETH_TX_FRAMES_MAX * IPHETH_BUF_SIZE),
                .flags = {.force_short_xfer = 1,},
                .callback = ipheth_bulk_write_callback,
                .timeout = IPHETH_TX_TIMEOUT,
        },
};

static device_method_t ipheth_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe, ipheth_probe),
        DEVMETHOD(device_attach, ipheth_attach),
        DEVMETHOD(device_detach, ipheth_detach),

        DEVMETHOD_END
};

static driver_t ipheth_driver = {
        .name = "ipheth",
        .methods = ipheth_methods,
        .size = sizeof(struct ipheth_softc),
};

static const STRUCT_USB_HOST_ID ipheth_devs[] = {
#if 0
        {IPHETH_ID(USB_VENDOR_APPLE, USB_PRODUCT_APPLE_IPHONE,
            IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
            IPHETH_USBINTF_PROTO)},
        {IPHETH_ID(USB_VENDOR_APPLE, USB_PRODUCT_APPLE_IPHONE_3G,
            IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
            IPHETH_USBINTF_PROTO)},
        {IPHETH_ID(USB_VENDOR_APPLE, USB_PRODUCT_APPLE_IPHONE_3GS,
            IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
            IPHETH_USBINTF_PROTO)},
        {IPHETH_ID(USB_VENDOR_APPLE, USB_PRODUCT_APPLE_IPHONE_4,
            IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
            IPHETH_USBINTF_PROTO)},
        {IPHETH_ID(USB_VENDOR_APPLE, USB_PRODUCT_APPLE_IPHONE_4S,
            IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
            IPHETH_USBINTF_PROTO)},
        {IPHETH_ID(USB_VENDOR_APPLE, USB_PRODUCT_APPLE_IPHONE_5,
            IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
            IPHETH_USBINTF_PROTO)},
#else
        /* product agnostic interface match */
        {USB_VENDOR(USB_VENDOR_APPLE),
         USB_IFACE_CLASS(IPHETH_USBINTF_CLASS),
         USB_IFACE_SUBCLASS(IPHETH_USBINTF_SUBCLASS),
         USB_IFACE_PROTOCOL(IPHETH_USBINTF_PROTO)},
#endif
};

DRIVER_MODULE(ipheth, uhub, ipheth_driver, NULL, NULL);
MODULE_VERSION(ipheth, 1);
MODULE_DEPEND(ipheth, uether, 1, 1, 1);
MODULE_DEPEND(ipheth, usb, 1, 1, 1);
MODULE_DEPEND(ipheth, ether, 1, 1, 1);
USB_PNP_HOST_INFO(ipheth_devs);

static const struct usb_ether_methods ipheth_ue_methods = {
        .ue_attach_post = ipheth_attach_post,
        .ue_start = ipheth_start,
        .ue_init = ipheth_init,
        .ue_tick = ipheth_tick,
        .ue_stop = ipheth_stop,
        .ue_setmulti = ipheth_setmulti,
        .ue_setpromisc = ipheth_setpromisc,
};

#define IPHETH_ID(v,p,c,sc,pt) \
    USB_VENDOR(v), USB_PRODUCT(p), \
    USB_IFACE_CLASS(c), USB_IFACE_SUBCLASS(sc), \
    USB_IFACE_PROTOCOL(pt)

static int
ipheth_get_mac_addr(struct ipheth_softc *sc)
{
        struct usb_device_request req;
        int error;

        req.bmRequestType = UT_READ_VENDOR_DEVICE;
        req.bRequest = IPHETH_CMD_GET_MACADDR;
        req.wValue[0] = 0;
        req.wValue[1] = 0;
        req.wIndex[0] = sc->sc_iface_no;
        req.wIndex[1] = 0;
        req.wLength[0] = ETHER_ADDR_LEN;
        req.wLength[1] = 0;

        error = usbd_do_request(sc->sc_ue.ue_udev, NULL, &req, sc->sc_data);

        if (error)
                return (error);

        memcpy(sc->sc_ue.ue_eaddr, sc->sc_data, ETHER_ADDR_LEN);

        return (0);
}

static bool
ipheth_enable_ncm(struct ipheth_softc *sc)
{
        struct usb_device_request req;

        req.bmRequestType = UT_WRITE_VENDOR_INTERFACE;
        req.bRequest = IPHETH_CMD_ENABLE_NCM;
        USETW(req.wValue, 0);
        req.wIndex[0] = sc->sc_iface_no;
        req.wIndex[1] = 0;
        USETW(req.wLength, 0);

        return (usbd_do_request(sc->sc_ue.ue_udev, NULL, &req, NULL) == 0);
}

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

        if (uaa->usb_mode != USB_MODE_HOST)
                return (ENXIO);

        return (usbd_lookup_id_by_uaa(ipheth_devs, sizeof(ipheth_devs), uaa));
}

static int
ipheth_attach(device_t dev)
{
        struct ipheth_softc *sc = device_get_softc(dev);
        struct usb_ether *ue = &sc->sc_ue;
        struct usb_attach_arg *uaa = device_get_ivars(dev);
        const struct usb_config *config;
        int error;

        sc->sc_iface_no = uaa->info.bIfaceIndex;

        device_set_usb_desc(dev);

        mtx_init(&sc->sc_mtx, device_get_nameunit(dev), NULL, MTX_DEF);

        error = usbd_set_alt_interface_index(uaa->device,
            uaa->info.bIfaceIndex, IPHETH_ALT_INTFNUM);
        if (error) {
                device_printf(dev, "Cannot set alternate setting\n");
                goto detach;
        }

        ue->ue_sc = sc;
        ue->ue_dev = dev;
        ue->ue_udev = uaa->device;
        ue->ue_mtx = &sc->sc_mtx;
        ue->ue_methods = &ipheth_ue_methods;

        if (ipheth_enable_ncm(sc)) {
                config = ipheth_config_ncm;
                sc->is_ncm = true;
                sc->consume = &ipheth_consume_read_ncm;
        } else {
                config = ipheth_config;
                sc->consume = &ipheth_consume_read;
        }

        error = usbd_transfer_setup(uaa->device, &sc->sc_iface_no, sc->sc_xfer,
            config, IPHETH_N_TRANSFER, sc, &sc->sc_mtx);
        if (error) {
                device_printf(dev, "Cannot setup USB transfers\n");
                goto detach;
        }

        error = ipheth_get_mac_addr(sc);
        if (error) {
                device_printf(dev, "Cannot get MAC address\n");
                goto detach;
        }

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

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

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

        /* stop all USB transfers first */
        usbd_transfer_unsetup(sc->sc_xfer, IPHETH_N_TRANSFER);

        uether_ifdetach(ue);

        mtx_destroy(&sc->sc_mtx);

        return (0);
}

static void
ipheth_start(struct usb_ether *ue)
{
        struct ipheth_softc *sc = uether_getsc(ue);

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

static void
ipheth_stop(struct usb_ether *ue)
{
        struct ipheth_softc *sc = uether_getsc(ue);

        /*
         * Stop the USB transfers, if not already stopped:
         */
        usbd_transfer_stop(sc->sc_xfer[IPHETH_BULK_TX]);
        usbd_transfer_stop(sc->sc_xfer[IPHETH_BULK_RX]);
}

static void
ipheth_tick(struct usb_ether *ue)
{
        struct ipheth_softc *sc = uether_getsc(ue);
        struct usb_device_request req;
        int error;

        req.bmRequestType = UT_READ_VENDOR_DEVICE;
        req.bRequest = IPHETH_CMD_CARRIER_CHECK;
        req.wValue[0] = 0;
        req.wValue[1] = 0;
        req.wIndex[0] = sc->sc_iface_no;
        req.wIndex[1] = 0;
        req.wLength[0] = IPHETH_CTRL_BUF_SIZE;
        req.wLength[1] = 0;

        error = uether_do_request(ue, &req, sc->sc_data, IPHETH_CTRL_TIMEOUT);

        if (error)
                return;

        sc->sc_carrier_on =
            (sc->sc_data[0] == IPHETH_CARRIER_ON);
}

static void
ipheth_attach_post(struct usb_ether *ue)
{

}

static void
ipheth_init(struct usb_ether *ue)
{
        struct ipheth_softc *sc = uether_getsc(ue);
        if_t ifp = uether_getifp(ue);

        IPHETH_LOCK_ASSERT(sc, MA_OWNED);

        if_setdrvflagbits(ifp, IFF_DRV_RUNNING, 0);

        /* stall data write direction, which depends on USB mode */
        usbd_xfer_set_stall(sc->sc_xfer[IPHETH_BULK_TX]);

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

static void
ipheth_setmulti(struct usb_ether *ue)
{

}

static void
ipheth_setpromisc(struct usb_ether *ue)
{

}

static void
ipheth_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
ipheth_bulk_write_callback(struct usb_xfer *xfer, usb_error_t error)
{
        struct ipheth_softc *sc = usbd_xfer_softc(xfer);
        if_t ifp = uether_getifp(&sc->sc_ue);
        struct usb_page_cache *pc;
        struct mbuf *m;
        uint8_t x;
        int actlen;
        int aframes;

        switch (USB_GET_STATE(xfer)) {
        case USB_ST_TRANSFERRED:
                usbd_xfer_status(xfer, &actlen, NULL, &aframes, NULL);
                DPRINTFN(11, "transfer complete: %u bytes in %u frames\n",
                    actlen, aframes);

                if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);

                /* free all previous TX buffers */
                ipheth_free_queue(sc->sc_tx_buf, IPHETH_TX_FRAMES_MAX);

                /* FALLTHROUGH */
        case USB_ST_SETUP:
tr_setup:
                for (x = 0; x != IPHETH_TX_FRAMES_MAX; x++) {
                        m = if_dequeue(ifp);

                        if (m == NULL)
                                break;

                        usbd_xfer_set_frame_offset(xfer,
                            x * IPHETH_BUF_SIZE, x);

                        pc = usbd_xfer_get_frame(xfer, x);

                        sc->sc_tx_buf[x] = m;

                        if (m->m_pkthdr.len > IPHETH_BUF_SIZE)
                                m->m_pkthdr.len = IPHETH_BUF_SIZE;

                        usbd_m_copy_in(pc, 0, m, 0, m->m_pkthdr.len);

                        usbd_xfer_set_frame_len(xfer, x, IPHETH_BUF_SIZE);

                        if (IPHETH_BUF_SIZE != m->m_pkthdr.len) {
                                usbd_frame_zero(pc, m->m_pkthdr.len,
                                        IPHETH_BUF_SIZE - m->m_pkthdr.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);
                }
                break;

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

                /* free all previous TX buffers */
                ipheth_free_queue(sc->sc_tx_buf, IPHETH_TX_FRAMES_MAX);

                /* count output errors */
                if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);

                if (error != USB_ERR_CANCELLED) {
                        /* try to clear stall first */
                        usbd_xfer_set_stall(xfer);
                        goto tr_setup;
                }
                break;
        }
}

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

        switch (USB_GET_STATE(xfer)) {
        case USB_ST_TRANSFERRED:
                usbd_xfer_status(xfer, &actlen, NULL, &aframes, NULL);
                DPRINTF("received %u bytes in %u frames\n", actlen, aframes);

                for (x = 0; x != aframes; x++)
                        sc->consume(xfer, x);

                /* FALLTHROUGH */
        case USB_ST_SETUP:
                if (!sc->is_ncm) {
                        for (x = 0; x != IPHETH_RX_FRAMES_MAX; x++) {
                                if (sc->sc_rx_buf[x] == NULL) {
                                        m = uether_newbuf();
                                        if (m == NULL)
                                                goto tr_stall;

                                        /* cancel alignment for ethernet */
                                        m_adj(m, ETHER_ALIGN);

                                        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);
                        }
                        usbd_xfer_set_frames(xfer, x);
                } else {
                        usbd_xfer_set_frame_len(xfer, 0,
                            IPHETH_RX_NCM_BUF_SIZE);
                        usbd_xfer_set_frames(xfer, 1);
                }

                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:
                        /* 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 */
                ipheth_free_queue(sc->sc_rx_buf, IPHETH_RX_FRAMES_MAX);
                break;
        }
}

static void
ipheth_consume_read(struct usb_xfer *xfer, int x)
{
        struct ipheth_softc *sc = usbd_xfer_softc(xfer);
        struct mbuf *m = sc->sc_rx_buf[x];
        int len;

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

        if (len < (int)(sizeof(struct ether_header) + IPHETH_RX_ADJ)) {
                m_freem(m);
                return;
        }

        m_adj(m, IPHETH_RX_ADJ);

        /* queue up mbuf */
        uether_rxmbuf(&sc->sc_ue, m, len - IPHETH_RX_ADJ);
}

static void
ipheth_consume_read_ncm(struct usb_xfer *xfer, int x)
{
        struct ipheth_softc *sc = usbd_xfer_softc(xfer);
        struct usb_page_cache *pc = usbd_xfer_get_frame(xfer, 0);
        struct ncm_data_cache ncm;
        if_t ifp = uether_getifp(&sc->sc_ue);
        struct mbuf *new_buf;
        int i, actlen;
        uint16_t dp_offset, dp_len;

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

        if (actlen < IPHETH_NCM_HEADER_SIZE)
                return;

        usbd_copy_out(pc, 0, &ncm.hdr, sizeof(ncm.hdr));

        if (UGETDW(ncm.hdr.dwSignature) != 0x484D434E)
                return;

        /* Dpt follows the hdr on iOS */
        if (UGETW(ncm.hdr.wDptIndex) != (int)(sizeof(struct usb_ncm16_hdr)))
                return;

        usbd_copy_out(pc, UGETW(ncm.hdr.wDptIndex), &ncm.dpt, sizeof(ncm.dpt));

        if (UGETDW(ncm.dpt.dwSignature) != 0x304D434E)
                return;

        usbd_copy_out(pc, UGETW(ncm.hdr.wDptIndex) + sizeof(ncm.dpt), &ncm.dp,
            sizeof(ncm.dp));

        for (i = 0; i < IPHETH_NCM_DPT_DP_NUM; ++i) {
                dp_offset = UGETW(ncm.dp[i].wFrameIndex);
                dp_len = UGETW(ncm.dp[i].wFrameLength);

                /* (3.3.1 USB CDC NCM spec v1.0) */
                if (dp_offset == 0 && dp_len == 0)
                        break;

                if (dp_offset < IPHETH_NCM_HEADER_SIZE || dp_offset >= actlen ||
                    actlen < (dp_len + dp_offset) ||
                    dp_len < sizeof(struct ether_header)) {
                        if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
                        continue;
                }
                if (dp_len > (MCLBYTES - ETHER_ALIGN)) {
                        if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
                        continue;
                }

                new_buf = uether_newbuf();
                if (new_buf == NULL) {
                        if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
                        continue;
                }
                usbd_copy_out(pc, dp_offset, new_buf->m_data, dp_len);
                uether_rxmbuf(&sc->sc_ue, new_buf, dp_len);
        }
}