usb-msd.c

xen 3.2.2 源码

                /* language ids */
                data[0] = 4;
                data[1] = 3;
                data[2] = 0x09;
                data[3] = 0x04;
                ret = 4;
                break;
            case 1:
                /* vendor description */
                ret = set_usb_string(data, "QEMU " QEMU_VERSION);
                break;
            case 2:
                /* product description */
                ret = set_usb_string(data, "QEMU USB HARDDRIVE");
                break;
            case 3:
                /* serial number */
                ret = set_usb_string(data, "1");
                break;
            default:
                goto fail;
            }
            break;
        default:
            goto fail;
        }
        break;
    case DeviceRequest | USB_REQ_GET_CONFIGURATION:
        data[0] = 1;
        ret = 1;
        break;
    case DeviceOutRequest | USB_REQ_SET_CONFIGURATION:
        ret = 0;
        break;
    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:
        if (value == 0 && index != 0x81) { /* clear ep halt */
            goto fail;
        }
        ret = 0;
        break;
        /* Class specific requests.  */
    case MassStorageReset:
        /* Reset state ready for the next CBW.  */
        s->mode = USB_MSDM_CBW;
        ret = 0;
        break;
    case GetMaxLun:
        data[0] = 0;
        ret = 1;
        break;
    default:
    fail:
        ret = USB_RET_STALL;
        break;
    }
    return ret;
}

static void usb_msd_cancel_io(USBPacket *p, void *opaque)
{
    MSDState *s = opaque;
    scsi_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;
            scsi_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) {
                    scsi_read_data(s->scsi_dev, s->tag);
                } else if (s->mode == USB_MSDM_DATAOUT) {
                    scsi_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_handle_destroy(USBDevice *dev)
{
    MSDState *s = (MSDState *)dev;

    scsi_disk_destroy(s->scsi_dev);
    bdrv_delete(s->bs);
    qemu_free(s);
}

USBDevice *usb_msd_init(const char *filename, BlockDriver *drv)
{
    MSDState *s;
    BlockDriverState *bdrv;

    s = qemu_mallocz(sizeof(MSDState));
    if (!s)
        return NULL;

    bdrv = bdrv_new("usb");
    if (bdrv_open2(bdrv, filename, 0, drv) < 0)
        goto fail;
    s->bs = bdrv;

    s->dev.speed = USB_SPEED_FULL;
    s->dev.handle_packet = usb_generic_handle_packet;

    s->dev.handle_reset = usb_msd_handle_reset;
    s->dev.handle_control = usb_msd_handle_control;
    s->dev.handle_data = usb_msd_handle_data;
    s->dev.handle_destroy = usb_msd_handle_destroy;

    snprintf(s->dev.devname, sizeof(s->dev.devname), "QEMU USB MSD(%.16s)",
             filename);

    s->scsi_dev = scsi_disk_init(bdrv, 0, usb_msd_command_complete, s);
    usb_msd_handle_reset((USBDevice *)s);
    return (USBDevice *)s;
 fail:
    qemu_free(s);
    return NULL;
}