Archipelago » qemu

/*

 * Block driver for RAW files (posix)

 *

 * Copyright (c) 2006 Fabrice Bellard

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

#include "qemu-common.h"

#include "qemu-timer.h"

#include "qemu-char.h"

#include "qemu-log.h"

#include "block_int.h"

#include "module.h"

#include "block/raw-posix-aio.h"

#if defined(__APPLE__) && (__MACH__)

#include <paths.h>

#include <sys/param.h>

#include <IOKit/IOKitLib.h>

#include <IOKit/IOBSD.h>

#include <IOKit/storage/IOMediaBSDClient.h>

#include <IOKit/storage/IOMedia.h>

#include <IOKit/storage/IOCDMedia.h>

//#include <IOKit/storage/IOCDTypes.h>

#include <CoreFoundation/CoreFoundation.h>

#endif

#ifdef __sun__

#define _POSIX_PTHREAD_SEMANTICS 1

#include <sys/dkio.h>

#endif

#ifdef __linux__

#include <sys/types.h>

#include <sys/stat.h>

#include <sys/ioctl.h>

#include <sys/param.h>

#include <linux/cdrom.h>

#include <linux/fd.h>

#include <linux/fs.h>

#endif

#ifdef CONFIG_FIEMAP

#include <linux/fiemap.h>

#endif

#if defined (__FreeBSD__) || defined(__FreeBSD_kernel__)

#include <sys/disk.h>

#include <sys/cdio.h>

#endif

#ifdef __OpenBSD__

#include <sys/ioctl.h>

#include <sys/disklabel.h>

#include <sys/dkio.h>

#endif

#ifdef __NetBSD__

#include <sys/ioctl.h>

#include <sys/disklabel.h>

#include <sys/dkio.h>

#include <sys/disk.h>

#endif

#ifdef __DragonFly__

#include <sys/ioctl.h>

#include <sys/diskslice.h>

#endif

#ifdef CONFIG_XFS

#include <xfs/xfs.h>

#endif

//#define DEBUG_FLOPPY

//#define DEBUG_BLOCK

#if defined(DEBUG_BLOCK)

#define DEBUG_BLOCK_PRINT(formatCstr, ...) do { if (qemu_log_enabled()) \

    { qemu_log(formatCstr, ## __VA_ARGS__); qemu_log_flush(); } } while (0)

#else

#define DEBUG_BLOCK_PRINT(formatCstr, ...)

#endif

/* OS X does not have O_DSYNC */

#ifndef O_DSYNC

#ifdef O_SYNC

#define O_DSYNC O_SYNC

#elif defined(O_FSYNC)

#define O_DSYNC O_FSYNC

#endif

#endif

/* Approximate O_DIRECT with O_DSYNC if O_DIRECT isn't available */

#ifndef O_DIRECT

#define O_DIRECT O_DSYNC

#endif

#define FTYPE_FILE   0

#define FTYPE_CD     1

#define FTYPE_FD     2

/* if the FD is not accessed during that time (in ns), we try to

   reopen it to see if the disk has been changed */

#define FD_OPEN_TIMEOUT (1000000000)

#define MAX_BLOCKSIZE        4096

typedef struct BDRVRawState {

    int fd;

    int type;

    int open_flags;

#if defined(__linux__)

    /* linux floppy specific */

    int64_t fd_open_time;

    int64_t fd_error_time;

    int fd_got_error;

    int fd_media_changed;

#endif

#ifdef CONFIG_LINUX_AIO

    int use_aio;

    void *aio_ctx;

#endif

    uint8_t *aligned_buf;

    unsigned aligned_buf_size;

#ifdef CONFIG_XFS

    bool is_xfs : 1;

#endif

} BDRVRawState;

static int fd_open(BlockDriverState *bs);

static int64_t raw_getlength(BlockDriverState *bs);

#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)

static int cdrom_reopen(BlockDriverState *bs);

#endif

#if defined(__NetBSD__)

static int raw_normalize_devicepath(const char **filename)

{

    static char namebuf[PATH_MAX];

    const char *dp, *fname;

    struct stat sb;

    fname = *filename;

    dp = strrchr(fname, '/');

    if (lstat(fname, &sb) < 0) {

        fprintf(stderr, "%s: stat failed: %s\n",

            fname, strerror(errno));

        return -errno;

    }

    if (!S_ISBLK(sb.st_mode)) {

        return 0;

    }

    if (dp == NULL) {

        snprintf(namebuf, PATH_MAX, "r%s", fname);

    } else {

        snprintf(namebuf, PATH_MAX, "%.*s/r%s",

            (int)(dp - fname), fname, dp + 1);

    }

    fprintf(stderr, "%s is a block device", fname);

    *filename = namebuf;

    fprintf(stderr, ", using %s\n", *filename);

    return 0;

}

#else

static int raw_normalize_devicepath(const char **filename)

{

    return 0;

}

#endif

#ifdef CONFIG_LINUX_AIO

static int raw_set_aio(void **aio_ctx, int *use_aio, int bdrv_flags)

{

    int ret = -1;

    assert(aio_ctx != NULL);

    assert(use_aio != NULL);

    /*

     * Currently Linux do AIO only for files opened with O_DIRECT

     * specified so check NOCACHE flag too

     */

    if ((bdrv_flags & (BDRV_O_NOCACHE|BDRV_O_NATIVE_AIO)) ==

                      (BDRV_O_NOCACHE|BDRV_O_NATIVE_AIO)) {

        /* if non-NULL, laio_init() has already been run */

        if (*aio_ctx == NULL) {

            *aio_ctx = laio_init();

            if (!*aio_ctx) {

                goto error;

            }

        }

        *use_aio = 1;

    } else {

        *use_aio = 0;

    }

    ret = 0;

error:

    return ret;

}

#endif

static int raw_open_common(BlockDriverState *bs, const char *filename,

                           int bdrv_flags, int open_flags)

{

    BDRVRawState *s = bs->opaque;

    int fd, ret;

    ret = raw_normalize_devicepath(&filename);

    if (ret != 0) {

        return ret;

    }

    s->open_flags = open_flags | O_BINARY;

    s->open_flags &= ~O_ACCMODE;

    if (bdrv_flags & BDRV_O_RDWR) {

        s->open_flags |= O_RDWR;

    } else {

        s->open_flags |= O_RDONLY;

    }

    /* Use O_DSYNC for write-through caching, no flags for write-back caching,

     * and O_DIRECT for no caching. */

    if ((bdrv_flags & BDRV_O_NOCACHE))

        s->open_flags |= O_DIRECT;

    if (!(bdrv_flags & BDRV_O_CACHE_WB))

        s->open_flags |= O_DSYNC;

    s->fd = -1;

    fd = qemu_open(filename, s->open_flags, 0644);

    if (fd < 0) {

        ret = -errno;

        if (ret == -EROFS)

            ret = -EACCES;

        return ret;

    }

    s->fd = fd;

    s->aligned_buf = NULL;

    if ((bdrv_flags & BDRV_O_NOCACHE)) {

        /*

         * Allocate a buffer for read/modify/write cycles.  Chose the size

         * pessimistically as we don't know the block size yet.

         */

        s->aligned_buf_size = 32 * MAX_BLOCKSIZE;

        s->aligned_buf = qemu_memalign(MAX_BLOCKSIZE, s->aligned_buf_size);

        if (s->aligned_buf == NULL) {

            goto out_close;

        }

    }

    /* We're falling back to POSIX AIO in some cases so init always */

    if (paio_init() < 0) {

        goto out_free_buf;

    }

#ifdef CONFIG_LINUX_AIO

    if (raw_set_aio(&s->aio_ctx, &s->use_aio, bdrv_flags)) {

        goto out_close;

    }

#endif

#ifdef CONFIG_XFS

    if (platform_test_xfs_fd(s->fd)) {

        s->is_xfs = 1;

    }

#endif

    return 0;

out_free_buf:

    qemu_vfree(s->aligned_buf);

out_close:

    qemu_close(fd);

    return -errno;

}

static int raw_open(BlockDriverState *bs, const char *filename, int flags)

{

    BDRVRawState *s = bs->opaque;

    s->type = FTYPE_FILE;

    return raw_open_common(bs, filename, flags, 0);

}

/* XXX: use host sector size if necessary with:

#ifdef DIOCGSECTORSIZE

        {

            unsigned int sectorsize = 512;

            if (!ioctl(fd, DIOCGSECTORSIZE, &sectorsize) &&

                sectorsize > bufsize)

                bufsize = sectorsize;

        }

#endif

#ifdef CONFIG_COCOA

        uint32_t blockSize = 512;

        if ( !ioctl( fd, DKIOCGETBLOCKSIZE, &blockSize ) && blockSize > bufsize) {

            bufsize = blockSize;

        }

#endif

*/

/*

 * Check if all memory in this vector is sector aligned.

 */

static int qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov)

{

    int i;

    for (i = 0; i < qiov->niov; i++) {

        if ((uintptr_t) qiov->iov[i].iov_base % bs->buffer_alignment) {

            return 0;

        }

    }

    return 1;

}

static BlockDriverAIOCB *raw_aio_submit(BlockDriverState *bs,

        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,

        BlockDriverCompletionFunc *cb, void *opaque, int type)

{

    BDRVRawState *s = bs->opaque;

    if (fd_open(bs) < 0)

        return NULL;

    /*

     * If O_DIRECT is used the buffer needs to be aligned on a sector

     * boundary.  Check if this is the case or tell the low-level

     * driver that it needs to copy the buffer.

     */

    if (s->aligned_buf) {

        if (!qiov_is_aligned(bs, qiov)) {

            type |= QEMU_AIO_MISALIGNED;

#ifdef CONFIG_LINUX_AIO

        } else if (s->use_aio) {

            return laio_submit(bs, s->aio_ctx, s->fd, sector_num, qiov,

                               nb_sectors, cb, opaque, type);

#endif

        }

    }

    return paio_submit(bs, s->fd, sector_num, qiov, nb_sectors,

                       cb, opaque, type);

}

static BlockDriverAIOCB *raw_aio_readv(BlockDriverState *bs,

        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,

        BlockDriverCompletionFunc *cb, void *opaque)

{

    return raw_aio_submit(bs, sector_num, qiov, nb_sectors,

                          cb, opaque, QEMU_AIO_READ);

}

static BlockDriverAIOCB *raw_aio_writev(BlockDriverState *bs,

        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,

        BlockDriverCompletionFunc *cb, void *opaque)

{

    return raw_aio_submit(bs, sector_num, qiov, nb_sectors,

                          cb, opaque, QEMU_AIO_WRITE);

}

static BlockDriverAIOCB *raw_aio_flush(BlockDriverState *bs,

        BlockDriverCompletionFunc *cb, void *opaque)

{

    BDRVRawState *s = bs->opaque;

    if (fd_open(bs) < 0)

        return NULL;

    return paio_submit(bs, s->fd, 0, NULL, 0, cb, opaque, QEMU_AIO_FLUSH);

}

static void raw_close(BlockDriverState *bs)

{

    BDRVRawState *s = bs->opaque;

    if (s->fd >= 0) {

        qemu_close(s->fd);

        s->fd = -1;

        if (s->aligned_buf != NULL)

            qemu_vfree(s->aligned_buf);

    }

}

static int raw_truncate(BlockDriverState *bs, int64_t offset)

{

    BDRVRawState *s = bs->opaque;

    struct stat st;

    if (fstat(s->fd, &st)) {

        return -errno;

    }

    if (S_ISREG(st.st_mode)) {

        if (ftruncate(s->fd, offset) < 0) {

            return -errno;

        }

    } else if (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode)) {

       if (offset > raw_getlength(bs)) {

           return -EINVAL;

       }

    } else {

        return -ENOTSUP;

    }

    return 0;

}

#ifdef __OpenBSD__

static int64_t raw_getlength(BlockDriverState *bs)

{

    BDRVRawState *s = bs->opaque;

    int fd = s->fd;

    struct stat st;

    if (fstat(fd, &st))

        return -1;

    if (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode)) {

        struct disklabel dl;

        if (ioctl(fd, DIOCGDINFO, &dl))

            return -1;

        return (uint64_t)dl.d_secsize *

            dl.d_partitions[DISKPART(st.st_rdev)].p_size;

    } else

        return st.st_size;

}

#elif defined(__NetBSD__)

static int64_t raw_getlength(BlockDriverState *bs)

{

    BDRVRawState *s = bs->opaque;

    int fd = s->fd;

    struct stat st;

    if (fstat(fd, &st))

        return -1;

    if (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode)) {

        struct dkwedge_info dkw;

        if (ioctl(fd, DIOCGWEDGEINFO, &dkw) != -1) {

            return dkw.dkw_size * 512;

        } else {

            struct disklabel dl;

            if (ioctl(fd, DIOCGDINFO, &dl))

                return -1;

            return (uint64_t)dl.d_secsize *

                dl.d_partitions[DISKPART(st.st_rdev)].p_size;

        }

    } else

        return st.st_size;

}

#elif defined(__sun__)

static int64_t raw_getlength(BlockDriverState *bs)

{

    BDRVRawState *s = bs->opaque;

    struct dk_minfo minfo;

    int ret;

    ret = fd_open(bs);

    if (ret < 0) {

        return ret;

    }

    /*

     * Use the DKIOCGMEDIAINFO ioctl to read the size.

     */

    ret = ioctl(s->fd, DKIOCGMEDIAINFO, &minfo);

    if (ret != -1) {

        return minfo.dki_lbsize * minfo.dki_capacity;

    }

    /*

     * There are reports that lseek on some devices fails, but

     * irc discussion said that contingency on contingency was overkill.

     */

    return lseek(s->fd, 0, SEEK_END);

}

#elif defined(CONFIG_BSD)

static int64_t raw_getlength(BlockDriverState *bs)

{

    BDRVRawState *s = bs->opaque;

    int fd = s->fd;

    int64_t size;

    struct stat sb;

#if defined (__FreeBSD__) || defined(__FreeBSD_kernel__)

    int reopened = 0;

#endif

    int ret;

    ret = fd_open(bs);

    if (ret < 0)

        return ret;

#if defined (__FreeBSD__) || defined(__FreeBSD_kernel__)

again:

#endif

    if (!fstat(fd, &sb) && (S_IFCHR & sb.st_mode)) {

#ifdef DIOCGMEDIASIZE

        if (ioctl(fd, DIOCGMEDIASIZE, (off_t *)&size))

#elif defined(DIOCGPART)

        {

                struct partinfo pi;

                if (ioctl(fd, DIOCGPART, &pi) == 0)

                        size = pi.media_size;

                else

                        size = 0;

        }

        if (size == 0)

#endif

#if defined(__APPLE__) && defined(__MACH__)

        size = LONG_LONG_MAX;

#else

        size = lseek(fd, 0LL, SEEK_END);

#endif

#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)

        switch(s->type) {

        case FTYPE_CD:

            /* XXX FreeBSD acd returns UINT_MAX sectors for an empty drive */

            if (size == 2048LL * (unsigned)-1)

                size = 0;

            /* XXX no disc?  maybe we need to reopen... */

            if (size <= 0 && !reopened && cdrom_reopen(bs) >= 0) {

                reopened = 1;

                goto again;

            }

        }

#endif

    } else {

        size = lseek(fd, 0, SEEK_END);

    }

    return size;

}

#else

static int64_t raw_getlength(BlockDriverState *bs)

{

    BDRVRawState *s = bs->opaque;

    int ret;

    ret = fd_open(bs);

    if (ret < 0) {

        return ret;

    }

    return lseek(s->fd, 0, SEEK_END);

}

#endif

static int64_t raw_get_allocated_file_size(BlockDriverState *bs)

{

    struct stat st;

    BDRVRawState *s = bs->opaque;

    if (fstat(s->fd, &st) < 0) {

        return -errno;

    }

    return (int64_t)st.st_blocks * 512;

}

static int raw_create(const char *filename, QEMUOptionParameter *options)

{

    int fd;

    int result = 0;

    int64_t total_size = 0;

    /* Read out options */

    while (options && options->name) {

        if (!strcmp(options->name, BLOCK_OPT_SIZE)) {

            total_size = options->value.n / BDRV_SECTOR_SIZE;

        }

        options++;

    }

    fd = qemu_open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,

                   0644);

    if (fd < 0) {

        result = -errno;

    } else {

        if (ftruncate(fd, total_size * BDRV_SECTOR_SIZE) != 0) {

            result = -errno;

        }

        if (qemu_close(fd) != 0) {

            result = -errno;

        }

    }

    return result;

}

/*

 * Returns true iff the specified sector is present in the disk image. Drivers

 * not implementing the functionality are assumed to not support backing files,

 * hence all their sectors are reported as allocated.

 *

 * If 'sector_num' is beyond the end of the disk image the return value is 0

 * and 'pnum' is set to 0.

 *

 * 'pnum' is set to the number of sectors (including and immediately following

 * the specified sector) that are known to be in the same

 * allocated/unallocated state.

 *

 * 'nb_sectors' is the max value 'pnum' should be set to.  If nb_sectors goes

 * beyond the end of the disk image it will be clamped.

 */

static int coroutine_fn raw_co_is_allocated(BlockDriverState *bs,

                                            int64_t sector_num,

                                            int nb_sectors, int *pnum)

{

    off_t start, data, hole;

    int ret;

    ret = fd_open(bs);

    if (ret < 0) {

        return ret;

    }

    start = sector_num * BDRV_SECTOR_SIZE;

#ifdef CONFIG_FIEMAP

    BDRVRawState *s = bs->opaque;

    struct {

        struct fiemap fm;

        struct fiemap_extent fe;

    } f;

    f.fm.fm_start = start;

    f.fm.fm_length = (int64_t)nb_sectors * BDRV_SECTOR_SIZE;

    f.fm.fm_flags = 0;

    f.fm.fm_extent_count = 1;

    f.fm.fm_reserved = 0;

    if (ioctl(s->fd, FS_IOC_FIEMAP, &f) == -1) {

        /* Assume everything is allocated.  */

        *pnum = nb_sectors;

        return 1;

    }

    if (f.fm.fm_mapped_extents == 0) {

        /* No extents found, data is beyond f.fm.fm_start + f.fm.fm_length.

         * f.fm.fm_start + f.fm.fm_length must be clamped to the file size!

         */

        off_t length = lseek(s->fd, 0, SEEK_END);

        hole = f.fm.fm_start;

        data = MIN(f.fm.fm_start + f.fm.fm_length, length);

    } else {

        data = f.fe.fe_logical;

        hole = f.fe.fe_logical + f.fe.fe_length;

    }

#elif defined SEEK_HOLE && defined SEEK_DATA

    BDRVRawState *s = bs->opaque;

    hole = lseek(s->fd, start, SEEK_HOLE);

    if (hole == -1) {

        /* -ENXIO indicates that sector_num was past the end of the file.

         * There is a virtual hole there.  */

        assert(errno != -ENXIO);

        /* Most likely EINVAL.  Assume everything is allocated.  */

        *pnum = nb_sectors;

        return 1;

    }

    if (hole > start) {

        data = start;

    } else {

        /* On a hole.  We need another syscall to find its end.  */

        data = lseek(s->fd, start, SEEK_DATA);

        if (data == -1) {

            data = lseek(s->fd, 0, SEEK_END);

        }

    }

#else

    *pnum = nb_sectors;

    return 1;

#endif

    if (data <= start) {

        /* On a data extent, compute sectors to the end of the extent.  */

        *pnum = MIN(nb_sectors, (hole - start) / BDRV_SECTOR_SIZE);

        return 1;

    } else {

        /* On a hole, compute sectors to the beginning of the next extent.  */

        *pnum = MIN(nb_sectors, (data - start) / BDRV_SECTOR_SIZE);

        return 0;

    }

}

#ifdef CONFIG_XFS

static int xfs_discard(BDRVRawState *s, int64_t sector_num, int nb_sectors)

{

    struct xfs_flock64 fl;

    memset(&fl, 0, sizeof(fl));

    fl.l_whence = SEEK_SET;

    fl.l_start = sector_num << 9;

    fl.l_len = (int64_t)nb_sectors << 9;

    if (xfsctl(NULL, s->fd, XFS_IOC_UNRESVSP64, &fl) < 0) {

        DEBUG_BLOCK_PRINT("cannot punch hole (%s)\n", strerror(errno));

        return -errno;

    }

    return 0;

}

#endif

static coroutine_fn int raw_co_discard(BlockDriverState *bs,

    int64_t sector_num, int nb_sectors)

{

#ifdef CONFIG_XFS

    BDRVRawState *s = bs->opaque;

    if (s->is_xfs) {

        return xfs_discard(s, sector_num, nb_sectors);

    }

#endif

    return 0;

}

static QEMUOptionParameter raw_create_options[] = {

    {

        .name = BLOCK_OPT_SIZE,

        .type = OPT_SIZE,

        .help = "Virtual disk size"

    },

    { NULL }

};

static BlockDriver bdrv_file = {

    .format_name = "file",

    .protocol_name = "file",

    .instance_size = sizeof(BDRVRawState),

    .bdrv_probe = NULL, /* no probe for protocols */

    .bdrv_file_open = raw_open,

    .bdrv_close = raw_close,

    .bdrv_create = raw_create,

    .bdrv_co_discard = raw_co_discard,

    .bdrv_co_is_allocated = raw_co_is_allocated,

    .bdrv_aio_readv = raw_aio_readv,

    .bdrv_aio_writev = raw_aio_writev,

    .bdrv_aio_flush = raw_aio_flush,

    .bdrv_truncate = raw_truncate,

    .bdrv_getlength = raw_getlength,

    .bdrv_get_allocated_file_size

                        = raw_get_allocated_file_size,

    .create_options = raw_create_options,

};

/***********************************************/

/* host device */

#if defined(__APPLE__) && defined(__MACH__)

static kern_return_t FindEjectableCDMedia( io_iterator_t *mediaIterator );

static kern_return_t GetBSDPath( io_iterator_t mediaIterator, char *bsdPath, CFIndex maxPathSize );

kern_return_t FindEjectableCDMedia( io_iterator_t *mediaIterator )

{

    kern_return_t       kernResult;

    mach_port_t     masterPort;

    CFMutableDictionaryRef  classesToMatch;

    kernResult = IOMasterPort( MACH_PORT_NULL, &masterPort );

    if ( KERN_SUCCESS != kernResult ) {

        printf( "IOMasterPort returned %d\n", kernResult );

    }

    classesToMatch = IOServiceMatching( kIOCDMediaClass );

    if ( classesToMatch == NULL ) {

        printf( "IOServiceMatching returned a NULL dictionary.\n" );

    } else {

    CFDictionarySetValue( classesToMatch, CFSTR( kIOMediaEjectableKey ), kCFBooleanTrue );

    }

    kernResult = IOServiceGetMatchingServices( masterPort, classesToMatch, mediaIterator );

    if ( KERN_SUCCESS != kernResult )

    {

        printf( "IOServiceGetMatchingServices returned %d\n", kernResult );

    }

    return kernResult;

}

kern_return_t GetBSDPath( io_iterator_t mediaIterator, char *bsdPath, CFIndex maxPathSize )

{

    io_object_t     nextMedia;

    kern_return_t   kernResult = KERN_FAILURE;

    *bsdPath = '\0';

    nextMedia = IOIteratorNext( mediaIterator );

    if ( nextMedia )

    {

        CFTypeRef   bsdPathAsCFString;

    bsdPathAsCFString = IORegistryEntryCreateCFProperty( nextMedia, CFSTR( kIOBSDNameKey ), kCFAllocatorDefault, 0 );

        if ( bsdPathAsCFString ) {

            size_t devPathLength;

            strcpy( bsdPath, _PATH_DEV );

            strcat( bsdPath, "r" );

            devPathLength = strlen( bsdPath );

            if ( CFStringGetCString( bsdPathAsCFString, bsdPath + devPathLength, maxPathSize - devPathLength, kCFStringEncodingASCII ) ) {

                kernResult = KERN_SUCCESS;

            }

            CFRelease( bsdPathAsCFString );

        }

        IOObjectRelease( nextMedia );

    }

    return kernResult;

}

#endif

static int hdev_probe_device(const char *filename)

{

    struct stat st;

    /* allow a dedicated CD-ROM driver to match with a higher priority */

    if (strstart(filename, "/dev/cdrom", NULL))

        return 50;

    if (stat(filename, &st) >= 0 &&

            (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode))) {

        return 100;

    }

    return 0;

}

static int hdev_open(BlockDriverState *bs, const char *filename, int flags)

{

    BDRVRawState *s = bs->opaque;

#if defined(__APPLE__) && defined(__MACH__)

    if (strstart(filename, "/dev/cdrom", NULL)) {

        kern_return_t kernResult;

        io_iterator_t mediaIterator;

        char bsdPath[ MAXPATHLEN ];

        int fd;

        kernResult = FindEjectableCDMedia( &mediaIterator );

        kernResult = GetBSDPath( mediaIterator, bsdPath, sizeof( bsdPath ) );

        if ( bsdPath[ 0 ] != '\0' ) {

            strcat(bsdPath,"s0");

            /* some CDs don't have a partition 0 */

            fd = qemu_open(bsdPath, O_RDONLY | O_BINARY | O_LARGEFILE);

            if (fd < 0) {

                bsdPath[strlen(bsdPath)-1] = '1';

            } else {

                qemu_close(fd);

            }

            filename = bsdPath;

        }

        if ( mediaIterator )

            IOObjectRelease( mediaIterator );

    }

#endif

    s->type = FTYPE_FILE;

#if defined(__linux__)

    {

        char resolved_path[ MAXPATHLEN ], *temp;

        temp = realpath(filename, resolved_path);

        if (temp && strstart(temp, "/dev/sg", NULL)) {

            bs->sg = 1;

        }

    }

#endif

    return raw_open_common(bs, filename, flags, 0);

}

#if defined(__linux__)