Archipelago » qemu

/*

 * QEMU System Emulator block driver

 * 

 * Copyright (c) 2003 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 "vl.h"

#include "block_int.h"

static BlockDriverState *bdrv_first;

static BlockDriver *first_drv;

void bdrv_register(BlockDriver *bdrv)

{

    bdrv->next = first_drv;

    first_drv = bdrv;

}

/* create a new block device (by default it is empty) */

BlockDriverState *bdrv_new(const char *device_name)

{

    BlockDriverState **pbs, *bs;

    bs = qemu_mallocz(sizeof(BlockDriverState));

    if(!bs)

        return NULL;

    pstrcpy(bs->device_name, sizeof(bs->device_name), device_name);

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

        /* insert at the end */

        pbs = &bdrv_first;

        while (*pbs != NULL)

            pbs = &(*pbs)->next;

        *pbs = bs;

    }

    return bs;

}

BlockDriver *bdrv_find_format(const char *format_name)

{

    BlockDriver *drv1;

    for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {

        if (!strcmp(drv1->format_name, format_name))

            return drv1;

    }

    return NULL;

}

int bdrv_create(BlockDriver *drv, 

                const char *filename, int64_t size_in_sectors,

                const char *backing_file, int flags)

{

    if (!drv->bdrv_create)

        return -ENOTSUP;

    return drv->bdrv_create(filename, size_in_sectors, backing_file, flags);

}

#ifdef _WIN32

static void get_tmp_filename(char *filename, int size)

{

    /* XXX: find a better function */

    tmpnam(filename);

}

#else

static void get_tmp_filename(char *filename, int size)

{

    int fd;

    /* XXX: race condition possible */

    pstrcpy(filename, size, "/tmp/vl.XXXXXX");

    fd = mkstemp(filename);

    close(fd);

}

#endif

static BlockDriver *find_image_format(const char *filename)

{

    int fd, ret, score, score_max;

    BlockDriver *drv1, *drv;

    uint8_t buf[1024];

    fd = open(filename, O_RDONLY | O_BINARY | O_LARGEFILE);

    if (fd < 0)

        return NULL;

    ret = read(fd, buf, sizeof(buf));

    if (ret < 0) {

        close(fd);

        return NULL;

    }

    close(fd);

    drv = NULL;

    score_max = 0;

    for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {

        score = drv1->bdrv_probe(buf, ret, filename);

        if (score > score_max) {

            score_max = score;

            drv = drv1;

        }

    }

    return drv;

}

int bdrv_open(BlockDriverState *bs, const char *filename, int snapshot)

{

    return bdrv_open2(bs, filename, snapshot, NULL);

}

int bdrv_open2(BlockDriverState *bs, const char *filename, int snapshot,

               BlockDriver *drv)

{

    int ret;

    char tmp_filename[1024];

    bs->read_only = 0;

    bs->is_temporary = 0;

    bs->encrypted = 0;

    if (snapshot) {

        BlockDriverState *bs1;

        int64_t total_size;

        /* if snapshot, we create a temporary backing file and open it

           instead of opening 'filename' directly */

        /* if there is a backing file, use it */

        bs1 = bdrv_new("");

        if (!bs1) {

            return -1;

        }

        if (bdrv_open(bs1, filename, 0) < 0) {

            bdrv_delete(bs1);

            return -1;

        }

        total_size = bs1->total_sectors;

        bdrv_delete(bs1);

        get_tmp_filename(tmp_filename, sizeof(tmp_filename));

        /* XXX: use cow for linux as it is more efficient ? */

        if (bdrv_create(&bdrv_qcow, tmp_filename, 

                        total_size, filename, 0) < 0) {

            return -1;

        }

        filename = tmp_filename;

        bs->is_temporary = 1;

    }

    pstrcpy(bs->filename, sizeof(bs->filename), filename);

    if (!drv) {

        drv = find_image_format(filename);

        if (!drv)

            return -1;

    }

    bs->drv = drv;

    bs->opaque = qemu_mallocz(drv->instance_size);

    if (bs->opaque == NULL && drv->instance_size > 0)

        return -1;

    ret = drv->bdrv_open(bs, filename);

    if (ret < 0) {

        qemu_free(bs->opaque);

        return -1;

    }

#ifndef _WIN32

    if (bs->is_temporary) {

        unlink(filename);

    }

#endif

    if (bs->backing_file[0] != '\0' && drv->bdrv_is_allocated) {

        /* if there is a backing file, use it */

        bs->backing_hd = bdrv_new("");

        if (!bs->backing_hd) {

        fail:

            bdrv_close(bs);

            return -1;

        }

        if (bdrv_open(bs->backing_hd, bs->backing_file, 0) < 0)

            goto fail;

    }

    bs->inserted = 1;

    /* call the change callback */

    if (bs->change_cb)

        bs->change_cb(bs->change_opaque);

    return 0;

}

void bdrv_close(BlockDriverState *bs)

{

    if (bs->inserted) {

        if (bs->backing_hd)

            bdrv_delete(bs->backing_hd);

        bs->drv->bdrv_close(bs);

        qemu_free(bs->opaque);

#ifdef _WIN32

        if (bs->is_temporary) {

            unlink(bs->filename);

        }

#endif

        bs->opaque = NULL;

        bs->drv = NULL;

        bs->inserted = 0;

        /* call the change callback */

        if (bs->change_cb)

            bs->change_cb(bs->change_opaque);

    }

}

void bdrv_delete(BlockDriverState *bs)

{

    /* XXX: remove the driver list */

    bdrv_close(bs);

    qemu_free(bs);

}

/* commit COW file into the raw image */

int bdrv_commit(BlockDriverState *bs)

{

    int64_t i;

    int n, j;

    unsigned char sector[512];

    if (!bs->inserted)

        return -ENOENT;

    if (bs->read_only) {

        return -EACCES;

    }

    if (!bs->backing_hd) {

        return -ENOTSUP;

    }

    for (i = 0; i < bs->total_sectors;) {

        if (bs->drv->bdrv_is_allocated(bs, i, 65536, &n)) {

            for(j = 0; j < n; j++) {

                if (bdrv_read(bs, i, sector, 1) != 0) {

                    return -EIO;

                }

                if (bdrv_write(bs->backing_hd, i, sector, 1) != 0) {

                    return -EIO;

                }

                i++;

            }

        } else {

            i += n;

        }

    }

    return 0;

}

/* return -1 if error */

int bdrv_read(BlockDriverState *bs, int64_t sector_num, 

              uint8_t *buf, int nb_sectors)

{

    int ret, n;

    BlockDriver *drv = bs->drv;

    if (!bs->inserted)

        return -1;

    while (nb_sectors > 0) {

        if (sector_num == 0 && bs->boot_sector_enabled) {

            memcpy(buf, bs->boot_sector_data, 512);

            n = 1;

        } else if (bs->backing_hd) {

            if (drv->bdrv_is_allocated(bs, sector_num, nb_sectors, &n)) {

                ret = drv->bdrv_read(bs, sector_num, buf, n);

                if (ret < 0)

                    return -1;

            } else {

                /* read from the base image */

                ret = bdrv_read(bs->backing_hd, sector_num, buf, n);

                if (ret < 0)

                    return -1;

            }

        } else {

            ret = drv->bdrv_read(bs, sector_num, buf, nb_sectors);

            if (ret < 0)

                return -1;

            /* no need to loop */

            break;

        }

        nb_sectors -= n;

        sector_num += n;

        buf += n * 512;

    }

    return 0;

}

/* return -1 if error */

int bdrv_write(BlockDriverState *bs, int64_t sector_num, 

               const uint8_t *buf, int nb_sectors)

{

    if (!bs->inserted)

        return -1;

    if (bs->read_only)

        return -1;

    return bs->drv->bdrv_write(bs, sector_num, buf, nb_sectors);

}

void bdrv_get_geometry(BlockDriverState *bs, int64_t *nb_sectors_ptr)

{

    *nb_sectors_ptr = bs->total_sectors;

}

/* force a given boot sector. */

void bdrv_set_boot_sector(BlockDriverState *bs, const uint8_t *data, int size)

{

    bs->boot_sector_enabled = 1;

    if (size > 512)

        size = 512;

    memcpy(bs->boot_sector_data, data, size);

    memset(bs->boot_sector_data + size, 0, 512 - size);

}

void bdrv_set_geometry_hint(BlockDriverState *bs, 

                            int cyls, int heads, int secs)

{

    bs->cyls = cyls;

    bs->heads = heads;

    bs->secs = secs;

}

void bdrv_set_type_hint(BlockDriverState *bs, int type)

{

    bs->type = type;

    bs->removable = ((type == BDRV_TYPE_CDROM ||

                      type == BDRV_TYPE_FLOPPY));

}

void bdrv_get_geometry_hint(BlockDriverState *bs, 

                            int *pcyls, int *pheads, int *psecs)

{

    *pcyls = bs->cyls;

    *pheads = bs->heads;

    *psecs = bs->secs;

}

int bdrv_get_type_hint(BlockDriverState *bs)

{

    return bs->type;

}

int bdrv_is_removable(BlockDriverState *bs)

{

    return bs->removable;

}

int bdrv_is_read_only(BlockDriverState *bs)

{

    return bs->read_only;

}

int bdrv_is_inserted(BlockDriverState *bs)

{

    return bs->inserted;

}

int bdrv_is_locked(BlockDriverState *bs)

{

    return bs->locked;

}

void bdrv_set_locked(BlockDriverState *bs, int locked)

{

    bs->locked = locked;

}

void bdrv_set_change_cb(BlockDriverState *bs, 

                        void (*change_cb)(void *opaque), void *opaque)

{

    bs->change_cb = change_cb;

    bs->change_opaque = opaque;

}

int bdrv_is_encrypted(BlockDriverState *bs)

{

    if (bs->backing_hd && bs->backing_hd->encrypted)

        return 1;

    return bs->encrypted;

}

int bdrv_set_key(BlockDriverState *bs, const char *key)

{

    int ret;

    if (bs->backing_hd && bs->backing_hd->encrypted) {

        ret = bdrv_set_key(bs->backing_hd, key);

        if (ret < 0)

            return ret;

        if (!bs->encrypted)

            return 0;

    }

    if (!bs->encrypted || !bs->drv || !bs->drv->bdrv_set_key)

        return -1;

    return bs->drv->bdrv_set_key(bs, key);

}

void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size)

{

    if (!bs->inserted || !bs->drv) {

        buf[0] = '\0';

    } else {

        pstrcpy(buf, buf_size, bs->drv->format_name);

    }

}

void bdrv_iterate_format(void (*it)(void *opaque, const char *name), 

                         void *opaque)

{

    BlockDriver *drv;

    for (drv = first_drv; drv != NULL; drv = drv->next) {

        it(opaque, drv->format_name);

    }

}

BlockDriverState *bdrv_find(const char *name)

{

    BlockDriverState *bs;

    for (bs = bdrv_first; bs != NULL; bs = bs->next) {

        if (!strcmp(name, bs->device_name))

            return bs;

    }

    return NULL;

}

void bdrv_iterate(void (*it)(void *opaque, const char *name), void *opaque)

{

    BlockDriverState *bs;

    for (bs = bdrv_first; bs != NULL; bs = bs->next) {

        it(opaque, bs->device_name);

    }

}

const char *bdrv_get_device_name(BlockDriverState *bs)

{

    return bs->device_name;

}

void bdrv_info(void)

{

    BlockDriverState *bs;

    for (bs = bdrv_first; bs != NULL; bs = bs->next) {

        term_printf("%s:", bs->device_name);

        term_printf(" type=");

        switch(bs->type) {

        case BDRV_TYPE_HD:

            term_printf("hd");

            break;

        case BDRV_TYPE_CDROM:

            term_printf("cdrom");

            break;

        case BDRV_TYPE_FLOPPY:

            term_printf("floppy");

            break;

        }

        term_printf(" removable=%d", bs->removable);

        if (bs->removable) {

            term_printf(" locked=%d", bs->locked);

        }

        if (bs->inserted) {

            term_printf(" file=%s", bs->filename);

            if (bs->backing_file[0] != '\0')

                term_printf(" backing_file=%s", bs->backing_file);

            term_printf(" ro=%d", bs->read_only);

            term_printf(" drv=%s", bs->drv->format_name);

            if (bs->encrypted)

                term_printf(" encrypted");

        } else {

            term_printf(" [not inserted]");

        }

        term_printf("\n");

    }

}

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

/* RAW block driver */

typedef struct BDRVRawState {

    int fd;

} BDRVRawState;

static int raw_probe(const uint8_t *buf, int buf_size, const char *filename)

{

    return 1; /* maybe */

}

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

{

    BDRVRawState *s = bs->opaque;

    int fd;

    int64_t size;

    fd = open(filename, O_RDWR | O_BINARY | O_LARGEFILE);

    if (fd < 0) {

        fd = open(filename, O_RDONLY | O_BINARY | O_LARGEFILE);

        if (fd < 0)

            return -1;

        bs->read_only = 1;

    }

    size = lseek(fd, 0, SEEK_END);

    bs->total_sectors = size / 512;

    s->fd = fd;

    return 0;

}

static int raw_read(BlockDriverState *bs, int64_t sector_num, 

                    uint8_t *buf, int nb_sectors)

{

    BDRVRawState *s = bs->opaque;

    int ret;

    lseek(s->fd, sector_num * 512, SEEK_SET);

    ret = read(s->fd, buf, nb_sectors * 512);

    if (ret != nb_sectors * 512) 

        return -1;

    return 0;

}

static int raw_write(BlockDriverState *bs, int64_t sector_num, 

                     const uint8_t *buf, int nb_sectors)

{

    BDRVRawState *s = bs->opaque;

    int ret;

    lseek(s->fd, sector_num * 512, SEEK_SET);

    ret = write(s->fd, buf, nb_sectors * 512);

    if (ret != nb_sectors * 512) 

        return -1;

    return 0;

}

static void raw_close(BlockDriverState *bs)

{

    BDRVRawState *s = bs->opaque;

    close(s->fd);

}

static int raw_create(const char *filename, int64_t total_size,

                      const char *backing_file, int flags)

{

    int fd;

    if (flags || backing_file)

        return -ENOTSUP;

    fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE, 

              0644);

    if (fd < 0)

        return -EIO;

    ftruncate(fd, total_size * 512);

    close(fd);

    return 0;

}

BlockDriver bdrv_raw = {

    "raw",

    sizeof(BDRVRawState),

    raw_probe,

    raw_open,

    raw_read,

    raw_write,

    raw_close,

    raw_create,

};

void bdrv_init(void)

{

    bdrv_register(&bdrv_raw);

#ifndef _WIN32

    bdrv_register(&bdrv_cow);

#endif

    bdrv_register(&bdrv_qcow);

    bdrv_register(&bdrv_vmdk);

    bdrv_register(&bdrv_cloop);

}