Archipelago » qemu

/*

 * USB Mass Storage Device emulation

 *

 * Copyright (c) 2006 CodeSourcery.

 * Written by Paul Brook

 *

 * This code is licenced under the LGPL.

 */

#include "vl.h"

//#define DEBUG_MSD

#ifdef DEBUG_MSD

#define DPRINTF(fmt, args...) \

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

#else

#define DPRINTF(fmt, args...) 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;

    BlockDriverState *bs;

    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;

};

static const uint8_t qemu_msd_dev_descriptor[] = {

        0x12,       /*  u8 bLength; */

        0x01,       /*  u8 bDescriptorType; Device */

        0x00, 0x01, /*  u16 bcdUSB; v1.0 */

        0x00,            /*  u8  bDeviceClass; */

        0x00,            /*  u8  bDeviceSubClass; */

        0x00,       /*  u8  bDeviceProtocol; [ low/full speeds only ] */

        0x08,       /*  u8  bMaxPacketSize0; 8 Bytes */

        /* Vendor and product id are arbitrary.  */

        0x00, 0x00, /*  u16 idVendor; */

         0x00, 0x00, /*  u16 idProduct; */

        0x00, 0x00, /*  u16 bcdDevice */

        0x01,       /*  u8  iManufacturer; */

        0x02,       /*  u8  iProduct; */

        0x03,       /*  u8  iSerialNumber; */

        0x01        /*  u8  bNumConfigurations; */

};

static const uint8_t qemu_msd_config_descriptor[] = {

        /* one configuration */

        0x09,       /*  u8  bLength; */

        0x02,       /*  u8  bDescriptorType; Configuration */

        0x20, 0x00, /*  u16 wTotalLength; */

        0x01,       /*  u8  bNumInterfaces; (1) */

        0x01,       /*  u8  bConfigurationValue; */

        0x00,       /*  u8  iConfiguration; */

        0xc0,       /*  u8  bmAttributes;

                                 Bit 7: must be set,

                                     6: Self-powered,

                                     5: Remote wakeup,

                                     4..0: resvd */

        0x00,       /*  u8  MaxPower; */

        /* one interface */

        0x09,       /*  u8  if_bLength; */

        0x04,       /*  u8  if_bDescriptorType; Interface */

        0x00,       /*  u8  if_bInterfaceNumber; */

        0x00,       /*  u8  if_bAlternateSetting; */

        0x02,       /*  u8  if_bNumEndpoints; */

        0x08,       /*  u8  if_bInterfaceClass; MASS STORAGE */

        0x06,       /*  u8  if_bInterfaceSubClass; SCSI */

        0x50,       /*  u8  if_bInterfaceProtocol; Bulk Only */

        0x00,       /*  u8  if_iInterface; */

        /* Bulk-In endpoint */

        0x07,       /*  u8  ep_bLength; */

        0x05,       /*  u8  ep_bDescriptorType; Endpoint */

        0x81,       /*  u8  ep_bEndpointAddress; IN Endpoint 1 */

         0x02,       /*  u8  ep_bmAttributes; Bulk */

         0x40, 0x00, /*  u16 ep_wMaxPacketSize; */

        0x00,       /*  u8  ep_bInterval; */

        /* Bulk-Out endpoint */

        0x07,       /*  u8  ep_bLength; */

        0x05,       /*  u8  ep_bDescriptorType; Endpoint */

        0x02,       /*  u8  ep_bEndpointAddress; OUT Endpoint 2 */

         0x02,       /*  u8  ep_bmAttributes; Bulk */

         0x40, 0x00, /*  u16 ep_wMaxPacketSize; */

        0x00        /*  u8  ep_bInterval; */

};

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) {

            scsi_read_data(s->scsi_dev, s->tag);

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

            scsi_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(void *opaque, int reason, uint32_t tag,

                                     uint32_t arg)

{

    MSDState *s = (MSDState *)opaque;

    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 = scsi_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 = 0;

    switch (request) {

    case DeviceRequest | USB_REQ_GET_STATUS:

        data[0] = (1 << USB_DEVICE_SELF_POWERED) |

            (dev->remote_wakeup << USB_DEVICE_REMOTE_WAKEUP);

        data[1] = 0x00;

        ret = 2;

        break;

    case DeviceOutRequest | USB_REQ_CLEAR_FEATURE:

        if (value == USB_DEVICE_REMOTE_WAKEUP) {

            dev->remote_wakeup = 0;

        } else {

            goto fail;

        }

        ret = 0;

        break;

    case DeviceOutRequest | USB_REQ_SET_FEATURE:

        if (value == USB_DEVICE_REMOTE_WAKEUP) {

            dev->remote_wakeup = 1;

        } else {

            goto fail;

        }

        ret = 0;

        break;

    case DeviceOutRequest | USB_REQ_SET_ADDRESS:

        dev->addr = value;

        ret = 0;

        break;

    case DeviceRequest | USB_REQ_GET_DESCRIPTOR:

        switch(value >> 8) {

        case USB_DT_DEVICE:

            memcpy(data, qemu_msd_dev_descriptor,

                   sizeof(qemu_msd_dev_descriptor));

            ret = sizeof(qemu_msd_dev_descriptor);

            break;

        case USB_DT_CONFIG:

            memcpy(data, qemu_msd_config_descriptor,

                   sizeof(qemu_msd_config_descriptor));

            ret = sizeof(qemu_msd_config_descriptor);

            break;

        case USB_DT_STRING:

            switch(value & 0xff) {

            case 0:

                /* 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)

{

    MSDState *s;

    BlockDriverState *bdrv;

    s = qemu_mallocz(sizeof(MSDState));

    if (!s)

        return NULL;

    bdrv = bdrv_new("usb");

    if (bdrv_open(bdrv, filename, 0) < 0)

        goto fail;

    if (qemu_key_check(bdrv, filename))

        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;

}