Archipelago » qemu

/*

 * USB Mass Storage Device emulation

 *

 * Copyright (c) 2006 CodeSourcery.

 * Written by Paul Brook

 *

 * This code is licenced under the LGPL.

 */

#include "qemu-common.h"

#include "qemu-option.h"

#include "qemu-config.h"

#include "usb.h"

#include "usb-desc.h"

#include "scsi.h"

#include "console.h"

#include "monitor.h"

#include "sysemu.h"

#include "blockdev.h"

//#define DEBUG_MSD

#ifdef DEBUG_MSD

#define DPRINTF(fmt, ...) \

do { printf("usb-msd: " fmt , ## __VA_ARGS__); } while (0)

#else

#define DPRINTF(fmt, ...) do {} while(0)

#endif

/* USB requests.  */

#define MassStorageReset  0xff

#define GetMaxLun         0xfe

enum USBMSDMode {

    USB_MSDM_CBW, /* Command Block.  */

    USB_MSDM_DATAOUT, /* Tranfer data to device.  */

    USB_MSDM_DATAIN, /* Transfer data from device.  */

    USB_MSDM_CSW /* Command Status.  */

};

typedef struct {

    USBDevice dev;

    enum USBMSDMode mode;

    uint32_t scsi_len;

    uint8_t *scsi_buf;

    uint32_t usb_len;

    uint8_t *usb_buf;

    uint32_t data_len;

    uint32_t residue;

    uint32_t tag;

    SCSIBus bus;

    BlockConf conf;

    SCSIDevice *scsi_dev;

    int result;

    /* For async completion.  */

    USBPacket *packet;

} MSDState;

struct usb_msd_cbw {

    uint32_t sig;

    uint32_t tag;

    uint32_t data_len;

    uint8_t flags;

    uint8_t lun;

    uint8_t cmd_len;

    uint8_t cmd[16];

};

struct usb_msd_csw {

    uint32_t sig;

    uint32_t tag;

    uint32_t residue;

    uint8_t status;

};

enum {

    STR_MANUFACTURER = 1,

    STR_PRODUCT,

    STR_SERIALNUMBER,

};

static const USBDescStrings desc_strings = {

    [STR_MANUFACTURER] = "QEMU " QEMU_VERSION,

    [STR_PRODUCT]      = "QEMU USB HARDDRIVE",

    [STR_SERIALNUMBER] = "1",

};

static const USBDescIface desc_iface0 = {

    .bInterfaceNumber              = 0,

    .bNumEndpoints                 = 2,

    .bInterfaceClass               = USB_CLASS_MASS_STORAGE,

    .bInterfaceSubClass            = 0x06, /* SCSI */

    .bInterfaceProtocol            = 0x50, /* Bulk */

    .eps = (USBDescEndpoint[]) {

        {

            .bEndpointAddress      = USB_DIR_IN | 0x01,

            .bmAttributes          = USB_ENDPOINT_XFER_BULK,

            .wMaxPacketSize        = 64,

        },{

            .bEndpointAddress      = USB_DIR_OUT | 0x02,

            .bmAttributes          = USB_ENDPOINT_XFER_BULK,

            .wMaxPacketSize        = 64,

        },

    }

};

static const USBDescDevice desc_device = {

    .bcdUSB                        = 0x0100,

    .bMaxPacketSize0               = 8,

    .bNumConfigurations            = 1,

    .confs = (USBDescConfig[]) {

        {

            .bNumInterfaces        = 1,

            .bConfigurationValue   = 1,

            .bmAttributes          = 0xc0,

            .ifs = &desc_iface0,

        },

    },

};

static const USBDesc desc = {

    .id = {

        .idVendor          = 0,

        .idProduct         = 0,

        .bcdDevice         = 0,

        .iManufacturer     = STR_MANUFACTURER,

        .iProduct          = STR_PRODUCT,

        .iSerialNumber     = STR_SERIALNUMBER,

    },

    .full = &desc_device,

    .str  = desc_strings,

};

static void usb_msd_copy_data(MSDState *s)

{

    uint32_t len;

    len = s->usb_len;

    if (len > s->scsi_len)

        len = s->scsi_len;

    if (s->mode == USB_MSDM_DATAIN) {

        memcpy(s->usb_buf, s->scsi_buf, len);

    } else {

        memcpy(s->scsi_buf, s->usb_buf, len);

    }

    s->usb_len -= len;

    s->scsi_len -= len;

    s->usb_buf += len;

    s->scsi_buf += len;

    s->data_len -= len;

    if (s->scsi_len == 0) {

        if (s->mode == USB_MSDM_DATAIN) {

            s->scsi_dev->info->read_data(s->scsi_dev, s->tag);

        } else if (s->mode == USB_MSDM_DATAOUT) {

            s->scsi_dev->info->write_data(s->scsi_dev, s->tag);

        }

    }

}

static void usb_msd_send_status(MSDState *s)

{

    struct usb_msd_csw csw;

    csw.sig = cpu_to_le32(0x53425355);

    csw.tag = cpu_to_le32(s->tag);

    csw.residue = s->residue;

    csw.status = s->result;

    memcpy(s->usb_buf, &csw, 13);

}

static void usb_msd_command_complete(SCSIBus *bus, int reason, uint32_t tag,

                                     uint32_t arg)

{

    MSDState *s = DO_UPCAST(MSDState, dev.qdev, bus->qbus.parent);

    USBPacket *p = s->packet;

    if (tag != s->tag) {

        fprintf(stderr, "usb-msd: Unexpected SCSI Tag 0x%x\n", tag);

    }

    if (reason == SCSI_REASON_DONE) {

        DPRINTF("Command complete %d\n", arg);

        s->residue = s->data_len;

        s->result = arg != 0;

        if (s->packet) {

            if (s->data_len == 0 && s->mode == USB_MSDM_DATAOUT) {

                /* A deferred packet with no write data remaining must be

                   the status read packet.  */

                usb_msd_send_status(s);

                s->mode = USB_MSDM_CBW;

            } else {

                if (s->data_len) {

                    s->data_len -= s->usb_len;

                    if (s->mode == USB_MSDM_DATAIN)

                        memset(s->usb_buf, 0, s->usb_len);

                    s->usb_len = 0;

                }

                if (s->data_len == 0)

                    s->mode = USB_MSDM_CSW;

            }

            s->packet = NULL;

            usb_packet_complete(p);

        } else if (s->data_len == 0) {

            s->mode = USB_MSDM_CSW;

        }

        return;

    }

    s->scsi_len = arg;

    s->scsi_buf = s->scsi_dev->info->get_buf(s->scsi_dev, tag);

    if (p) {

        usb_msd_copy_data(s);

        if (s->usb_len == 0) {

            /* Set s->packet to NULL before calling usb_packet_complete

               because annother request may be issued before

               usb_packet_complete returns.  */

            DPRINTF("Packet complete %p\n", p);

            s->packet = NULL;

            usb_packet_complete(p);

        }

    }

}

static void usb_msd_handle_reset(USBDevice *dev)

{

    MSDState *s = (MSDState *)dev;

    DPRINTF("Reset\n");

    s->mode = USB_MSDM_CBW;

}

static int usb_msd_handle_control(USBDevice *dev, int request, int value,

                                  int index, int length, uint8_t *data)

{

    MSDState *s = (MSDState *)dev;

    int ret;

    ret = usb_desc_handle_control(dev, request, value, index, length, data);

    if (ret >= 0) {

        return ret;

    }

    ret = 0;

    switch (request) {

    case DeviceRequest | USB_REQ_GET_INTERFACE:

        data[0] = 0;

        ret = 1;

        break;

    case DeviceOutRequest | USB_REQ_SET_INTERFACE:

        ret = 0;

        break;

    case EndpointOutRequest | USB_REQ_CLEAR_FEATURE:

        ret = 0;

        break;

    case InterfaceOutRequest | USB_REQ_SET_INTERFACE:

        ret = 0;

        break;

        /* Class specific requests.  */

    case ClassInterfaceOutRequest | MassStorageReset:

        /* Reset state ready for the next CBW.  */

        s->mode = USB_MSDM_CBW;

        ret = 0;

        break;

    case ClassInterfaceRequest | GetMaxLun:

        data[0] = 0;

        ret = 1;

        break;

    default:

        ret = USB_RET_STALL;

        break;

    }

    return ret;

}

static void usb_msd_cancel_io(USBPacket *p, void *opaque)

{

    MSDState *s = opaque;

    s->scsi_dev->info->cancel_io(s->scsi_dev, s->tag);

    s->packet = NULL;

    s->scsi_len = 0;

}

static int usb_msd_handle_data(USBDevice *dev, USBPacket *p)

{

    MSDState *s = (MSDState *)dev;

    int ret = 0;

    struct usb_msd_cbw cbw;

    uint8_t devep = p->devep;

    uint8_t *data = p->data;

    int len = p->len;

    switch (p->pid) {

    case USB_TOKEN_OUT:

        if (devep != 2)

            goto fail;

        switch (s->mode) {

        case USB_MSDM_CBW:

            if (len != 31) {

                fprintf(stderr, "usb-msd: Bad CBW size");

                goto fail;

            }

            memcpy(&cbw, data, 31);

            if (le32_to_cpu(cbw.sig) != 0x43425355) {

                fprintf(stderr, "usb-msd: Bad signature %08x\n",

                        le32_to_cpu(cbw.sig));

                goto fail;

            }

            DPRINTF("Command on LUN %d\n", cbw.lun);

            if (cbw.lun != 0) {

                fprintf(stderr, "usb-msd: Bad LUN %d\n", cbw.lun);

                goto fail;

            }

            s->tag = le32_to_cpu(cbw.tag);

            s->data_len = le32_to_cpu(cbw.data_len);

            if (s->data_len == 0) {

                s->mode = USB_MSDM_CSW;

            } else if (cbw.flags & 0x80) {

                s->mode = USB_MSDM_DATAIN;

            } else {

                s->mode = USB_MSDM_DATAOUT;

            }

            DPRINTF("Command tag 0x%x flags %08x len %d data %d\n",

                    s->tag, cbw.flags, cbw.cmd_len, s->data_len);

            s->residue = 0;

            s->scsi_dev->info->send_command(s->scsi_dev, s->tag, cbw.cmd, 0);

            /* ??? Should check that USB and SCSI data transfer

               directions match.  */

            if (s->residue == 0) {

                if (s->mode == USB_MSDM_DATAIN) {

                    s->scsi_dev->info->read_data(s->scsi_dev, s->tag);

                } else if (s->mode == USB_MSDM_DATAOUT) {

                    s->scsi_dev->info->write_data(s->scsi_dev, s->tag);

                }

            }

            ret = len;

            break;

        case USB_MSDM_DATAOUT:

            DPRINTF("Data out %d/%d\n", len, s->data_len);

            if (len > s->data_len)

                goto fail;

            s->usb_buf = data;

            s->usb_len = len;

            if (s->scsi_len) {

                usb_msd_copy_data(s);

            }

            if (s->residue && s->usb_len) {

                s->data_len -= s->usb_len;

                if (s->data_len == 0)

                    s->mode = USB_MSDM_CSW;

                s->usb_len = 0;

            }

            if (s->usb_len) {

                DPRINTF("Deferring packet %p\n", p);

                usb_defer_packet(p, usb_msd_cancel_io, s);

                s->packet = p;

                ret = USB_RET_ASYNC;

            } else {

                ret = len;

            }

            break;

        default:

            DPRINTF("Unexpected write (len %d)\n", len);

            goto fail;

        }

        break;

    case USB_TOKEN_IN:

        if (devep != 1)

            goto fail;

        switch (s->mode) {

        case USB_MSDM_DATAOUT:

            if (s->data_len != 0 || len < 13)

                goto fail;

            /* Waiting for SCSI write to complete.  */

            usb_defer_packet(p, usb_msd_cancel_io, s);

            s->packet = p;

            ret = USB_RET_ASYNC;

            break;

        case USB_MSDM_CSW:

            DPRINTF("Command status %d tag 0x%x, len %d\n",

                    s->result, s->tag, len);

            if (len < 13)

                goto fail;

            s->usb_len = len;

            s->usb_buf = data;

            usb_msd_send_status(s);

            s->mode = USB_MSDM_CBW;

            ret = 13;

            break;

        case USB_MSDM_DATAIN:

            DPRINTF("Data in %d/%d\n", len, s->data_len);

            if (len > s->data_len)

                len = s->data_len;

            s->usb_buf = data;

            s->usb_len = len;

            if (s->scsi_len) {

                usb_msd_copy_data(s);

            }

            if (s->residue && s->usb_len) {

                s->data_len -= s->usb_len;

                memset(s->usb_buf, 0, s->usb_len);

                if (s->data_len == 0)

                    s->mode = USB_MSDM_CSW;

                s->usb_len = 0;

            }

            if (s->usb_len) {

                DPRINTF("Deferring packet %p\n", p);

                usb_defer_packet(p, usb_msd_cancel_io, s);

                s->packet = p;

                ret = USB_RET_ASYNC;

            } else {

                ret = len;

            }

            break;

        default:

            DPRINTF("Unexpected read (len %d)\n", len);

            goto fail;

        }

        break;

    default:

        DPRINTF("Bad token\n");

    fail:

        ret = USB_RET_STALL;

        break;

    }

    return ret;

}

static void usb_msd_password_cb(void *opaque, int err)

{

    MSDState *s = opaque;

    if (!err)

        usb_device_attach(&s->dev);

    else

        qdev_unplug(&s->dev.qdev);

}

static int usb_msd_initfn(USBDevice *dev)

{

    MSDState *s = DO_UPCAST(MSDState, dev, dev);

    BlockDriverState *bs = s->conf.bs;

    DriveInfo *dinfo;

    if (!bs) {

        error_report("usb-msd: drive property not set");

        return -1;

    }

    /*

     * Hack alert: this pretends to be a block device, but it's really

     * a SCSI bus that can serve only a single device, which it

     * creates automatically.  But first it needs to detach from its

     * blockdev, or else scsi_bus_legacy_add_drive() dies when it

     * attaches again.

     *

     * The hack is probably a bad idea.

     */

    bdrv_detach(bs, &s->dev.qdev);

    s->conf.bs = NULL;

    dinfo = drive_get_by_blockdev(bs);

    if (dinfo && dinfo->serial) {

        usb_desc_set_string(dev, STR_SERIALNUMBER, dinfo->serial);

    }

    usb_desc_init(dev);

    scsi_bus_new(&s->bus, &s->dev.qdev, 0, 1, usb_msd_command_complete);

    s->scsi_dev = scsi_bus_legacy_add_drive(&s->bus, bs, 0);

    if (!s->scsi_dev) {

        return -1;

    }

    s->bus.qbus.allow_hotplug = 0;

    usb_msd_handle_reset(dev);

    if (bdrv_key_required(bs)) {

        if (cur_mon) {

            monitor_read_bdrv_key_start(cur_mon, bs, usb_msd_password_cb, s);

            s->dev.auto_attach = 0;

        } else {

            autostart = 0;

        }

    }

    return 0;

}

static USBDevice *usb_msd_init(const char *filename)

{

    static int nr=0;

    char id[8];

    QemuOpts *opts;

    DriveInfo *dinfo;

    USBDevice *dev;

    int fatal_error;

    const char *p1;

    char fmt[32];

    /* parse -usbdevice disk: syntax into drive opts */

    snprintf(id, sizeof(id), "usb%d", nr++);

    opts = qemu_opts_create(qemu_find_opts("drive"), id, 0);

    p1 = strchr(filename, ':');

    if (p1++) {

        const char *p2;

        if (strstart(filename, "format=", &p2)) {

            int len = MIN(p1 - p2, sizeof(fmt));

            pstrcpy(fmt, len, p2);

            qemu_opt_set(opts, "format", fmt);

        } else if (*filename != ':') {

            printf("unrecognized USB mass-storage option %s\n", filename);

            return NULL;

        }

        filename = p1;

    }

    if (!*filename) {

        printf("block device specification needed\n");

        return NULL;

    }

    qemu_opt_set(opts, "file", filename);

    qemu_opt_set(opts, "if", "none");

    /* create host drive */

    dinfo = drive_init(opts, 0, &fatal_error);

    if (!dinfo) {

        qemu_opts_del(opts);

        return NULL;

    }

    /* create guest device */

    dev = usb_create(NULL /* FIXME */, "usb-storage");

    if (!dev) {

        return NULL;

    }

    if (qdev_prop_set_drive(&dev->qdev, "drive", dinfo->bdrv) < 0) {

        qdev_free(&dev->qdev);

        return NULL;

    }

    if (qdev_init(&dev->qdev) < 0)

        return NULL;

    return dev;

}

static struct USBDeviceInfo msd_info = {

    .product_desc   = "QEMU USB MSD",

    .qdev.name      = "usb-storage",

    .qdev.size      = sizeof(MSDState),

    .usb_desc       = &desc,

    .init           = usb_msd_initfn,

    .handle_packet  = usb_generic_handle_packet,

    .handle_reset   = usb_msd_handle_reset,

    .handle_control = usb_msd_handle_control,

    .handle_data    = usb_msd_handle_data,

    .usbdevice_name = "disk",

    .usbdevice_init = usb_msd_init,

    .qdev.props     = (Property[]) {

        DEFINE_BLOCK_PROPERTIES(MSDState, conf),

        DEFINE_PROP_END_OF_LIST(),

    },

};

static void usb_msd_register_devices(void)

{

    usb_qdev_register(&msd_info);

}

device_init(usb_msd_register_devices)