/*

 * Block driver for the VMDK format

 *

 * Copyright (c) 2004 Fabrice Bellard

 * Copyright (c) 2005 Filip Navara

 *

 * 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 "block_int.h"

#define VMDK3_MAGIC (('C' << 24) | ('O' << 16) | ('W' << 8) | 'D')

#define VMDK4_MAGIC (('K' << 24) | ('D' << 16) | ('M' << 8) | 'V')

typedef struct {

    uint32_t version;

    uint32_t flags;

    uint32_t disk_sectors;

    uint32_t granularity;

    uint32_t l1dir_offset;

    uint32_t l1dir_size;

    uint32_t file_sectors;

    uint32_t cylinders;

    uint32_t heads;

    uint32_t sectors_per_track;

} VMDK3Header;

typedef struct {

    uint32_t version;

    uint32_t flags;

    int64_t capacity;

    int64_t granularity;

    int64_t desc_offset;

    int64_t desc_size;

    int32_t num_gtes_per_gte;

    int64_t rgd_offset;

    int64_t gd_offset;

    int64_t grain_offset;

    char filler[1];

    char check_bytes[4];

} __attribute__((packed)) VMDK4Header;

#define L2_CACHE_SIZE 16

typedef struct BDRVVmdkState {

    BlockDriverState *hd;

    int64_t l1_table_offset;

    int64_t l1_backup_table_offset;

    uint32_t *l1_table;

    uint32_t *l1_backup_table;

    unsigned int l1_size;

    uint32_t l1_entry_sectors;

    unsigned int l2_size;

    uint32_t *l2_cache;

    uint32_t l2_cache_offsets[L2_CACHE_SIZE];

    uint32_t l2_cache_counts[L2_CACHE_SIZE];

    unsigned int cluster_sectors;

    uint32_t parent_cid;

    int is_parent;

} BDRVVmdkState;

typedef struct VmdkMetaData {

    uint32_t offset;

    unsigned int l1_index;

    unsigned int l2_index;

    unsigned int l2_offset;

    int valid;

} VmdkMetaData;

typedef struct ActiveBDRVState{

    BlockDriverState *hd;            // active image handler

    uint64_t cluster_offset;         // current write offset

}ActiveBDRVState;

static ActiveBDRVState activeBDRV;

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

{

    uint32_t magic;

    if (buf_size < 4)

        return 0;

    magic = be32_to_cpu(*(uint32_t *)buf);

    if (magic == VMDK3_MAGIC ||

        magic == VMDK4_MAGIC)

        return 100;

    else

        return 0;

}

#define CHECK_CID 1

#define SECTOR_SIZE 512

#define DESC_SIZE 20*SECTOR_SIZE	// 20 sectors of 512 bytes each

#define HEADER_SIZE 512   			// first sector of 512 bytes

static uint32_t vmdk_read_cid(BlockDriverState *bs, int parent)

{

    BDRVVmdkState *s = bs->opaque;

    char desc[DESC_SIZE];

    uint32_t cid;

    const char *p_name, *cid_str;

    size_t cid_str_size;

    /* the descriptor offset = 0x200 */

    if (bdrv_pread(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)

        return 0;

    if (parent) {

        cid_str = "parentCID";

        cid_str_size = sizeof("parentCID");

    } else {

        cid_str = "CID";

        cid_str_size = sizeof("CID");

    }

    if ((p_name = strstr(desc,cid_str)) != 0) {

        p_name += cid_str_size;

        sscanf(p_name,"%x",&cid);

    }

    return cid;

}

static int vmdk_write_cid(BlockDriverState *bs, uint32_t cid)

{

    BDRVVmdkState *s = bs->opaque;

    char desc[DESC_SIZE], tmp_desc[DESC_SIZE];

    char *p_name, *tmp_str;

    /* the descriptor offset = 0x200 */

    if (bdrv_pread(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)

        return -1;

    tmp_str = strstr(desc,"parentCID");

    pstrcpy(tmp_desc, sizeof(tmp_desc), tmp_str);

    if ((p_name = strstr(desc,"CID")) != 0) {

        p_name += sizeof("CID");

        snprintf(p_name, sizeof(desc) - (p_name - desc), "%x\n", cid);

        pstrcat(desc, sizeof(desc), tmp_desc);

    }

    if (bdrv_pwrite(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)

        return -1;

    return 0;

}

static int vmdk_is_cid_valid(BlockDriverState *bs)

{

#ifdef CHECK_CID

    BDRVVmdkState *s = bs->opaque;

    BlockDriverState *p_bs = s->hd->backing_hd;

    uint32_t cur_pcid;

    if (p_bs) {

        cur_pcid = vmdk_read_cid(p_bs,0);

        if (s->parent_cid != cur_pcid)

            // CID not valid

            return 0;

    }

#endif

    // CID valid

    return 1;

}

static int vmdk_snapshot_create(const char *filename, const char *backing_file)

{

    int snp_fd, p_fd;

    uint32_t p_cid;

    char *p_name, *gd_buf, *rgd_buf;

    const char *real_filename, *temp_str;

    VMDK4Header header;

    uint32_t gde_entries, gd_size;

    int64_t gd_offset, rgd_offset, capacity, gt_size;

    char p_desc[DESC_SIZE], s_desc[DESC_SIZE], hdr[HEADER_SIZE];

    static const char desc_template[] =

    "# Disk DescriptorFile\n"

    "version=1\n"

    "CID=%x\n"

    "parentCID=%x\n"

    "createType=\"monolithicSparse\"\n"

    "parentFileNameHint=\"%s\"\n"

    "\n"

    "# Extent description\n"

    "RW %u SPARSE \"%s\"\n"

    "\n"

    "# The Disk Data Base \n"

    "#DDB\n"

    "\n";

    snp_fd = open(filename, O_RDWR | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE, 0644);

    if (snp_fd < 0)

        return -1;

    p_fd = open(backing_file, O_RDONLY | O_BINARY | O_LARGEFILE);

    if (p_fd < 0) {

        close(snp_fd);

        return -1;

    }

    /* read the header */

    if (lseek(p_fd, 0x0, SEEK_SET) == -1)

        goto fail;

    if (read(p_fd, hdr, HEADER_SIZE) != HEADER_SIZE)

        goto fail;

    /* write the header */

    if (lseek(snp_fd, 0x0, SEEK_SET) == -1)

        goto fail;

    if (write(snp_fd, hdr, HEADER_SIZE) == -1)

        goto fail;

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

    memcpy(&header,&hdr[4], sizeof(header)); // skip the VMDK4_MAGIC

    ftruncate(snp_fd, header.grain_offset << 9);

    /* the descriptor offset = 0x200 */

    if (lseek(p_fd, 0x200, SEEK_SET) == -1)

        goto fail;

    if (read(p_fd, p_desc, DESC_SIZE) != DESC_SIZE)

        goto fail;

    if ((p_name = strstr(p_desc,"CID")) != 0) {

        p_name += sizeof("CID");

        sscanf(p_name,"%x",&p_cid);

    }

    real_filename = filename;

    if ((temp_str = strrchr(real_filename, '\\')) != NULL)

        real_filename = temp_str + 1;

    if ((temp_str = strrchr(real_filename, '/')) != NULL)

        real_filename = temp_str + 1;

    if ((temp_str = strrchr(real_filename, ':')) != NULL)

        real_filename = temp_str + 1;

    snprintf(s_desc, sizeof(s_desc), desc_template, p_cid, p_cid, backing_file,

             (uint32_t)header.capacity, real_filename);

    /* write the descriptor */

    if (lseek(snp_fd, 0x200, SEEK_SET) == -1)

        goto fail;

    if (write(snp_fd, s_desc, strlen(s_desc)) == -1)

        goto fail;

    gd_offset = header.gd_offset * SECTOR_SIZE;     // offset of GD table

    rgd_offset = header.rgd_offset * SECTOR_SIZE;   // offset of RGD table

    capacity = header.capacity * SECTOR_SIZE;       // Extent size

    /*

     * Each GDE span 32M disk, means:

     * 512 GTE per GT, each GTE points to grain

     */

    gt_size = (int64_t)header.num_gtes_per_gte * header.granularity * SECTOR_SIZE;

    if (!gt_size)

        goto fail;

    gde_entries = (uint32_t)(capacity / gt_size);  // number of gde/rgde

    gd_size = gde_entries * sizeof(uint32_t);

    /* write RGD */

    rgd_buf = qemu_malloc(gd_size);

    if (!rgd_buf)

        goto fail;

    if (lseek(p_fd, rgd_offset, SEEK_SET) == -1)

        goto fail_rgd;

    if (read(p_fd, rgd_buf, gd_size) != gd_size)

        goto fail_rgd;

    if (lseek(snp_fd, rgd_offset, SEEK_SET) == -1)

        goto fail_rgd;

    if (write(snp_fd, rgd_buf, gd_size) == -1)

        goto fail_rgd;

    qemu_free(rgd_buf);

    /* write GD */

    gd_buf = qemu_malloc(gd_size);

    if (!gd_buf)

        goto fail_rgd;

    if (lseek(p_fd, gd_offset, SEEK_SET) == -1)

        goto fail_gd;

    if (read(p_fd, gd_buf, gd_size) != gd_size)

        goto fail_gd;

    if (lseek(snp_fd, gd_offset, SEEK_SET) == -1)

        goto fail_gd;

    if (write(snp_fd, gd_buf, gd_size) == -1)

        goto fail_gd;

    qemu_free(gd_buf);

    close(p_fd);

    close(snp_fd);

    return 0;

    fail_gd:

    qemu_free(gd_buf);

    fail_rgd:

    qemu_free(rgd_buf);

    fail:

    close(p_fd);

    close(snp_fd);

    return -1;

}

static void vmdk_parent_close(BlockDriverState *bs)

{

    if (bs->backing_hd)

        bdrv_close(bs->backing_hd);

}

static int parent_open = 0;

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

{

    BDRVVmdkState *s = bs->opaque;

    char *p_name;

    char desc[DESC_SIZE];

    char parent_img_name[1024];

    /* the descriptor offset = 0x200 */

    if (bdrv_pread(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)

        return -1;

    if ((p_name = strstr(desc,"parentFileNameHint")) != 0) {

        char *end_name;

        struct stat file_buf;

        p_name += sizeof("parentFileNameHint") + 1;

        if ((end_name = strchr(p_name,'\"')) == 0)

            return -1;

        if ((end_name - p_name) > sizeof (s->hd->backing_file) - 1)

            return -1;

        pstrcpy(s->hd->backing_file, end_name - p_name + 1, p_name);

        if (stat(s->hd->backing_file, &file_buf) != 0) {

            path_combine(parent_img_name, sizeof(parent_img_name),

                         filename, s->hd->backing_file);

        } else {

            pstrcpy(parent_img_name, sizeof(parent_img_name),

                    s->hd->backing_file);

        }

        s->hd->backing_hd = bdrv_new("");

        if (!s->hd->backing_hd) {

            failure:

            bdrv_close(s->hd);

            return -1;

        }

        parent_open = 1;

        if (bdrv_open(s->hd->backing_hd, parent_img_name, BDRV_O_RDONLY) < 0)

            goto failure;

        parent_open = 0;

    }

    return 0;

}

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

{

    BDRVVmdkState *s = bs->opaque;

    uint32_t magic;

    int l1_size, i, ret;

    if (parent_open)

        // Parent must be opened as RO.

        flags = BDRV_O_RDONLY;

    ret = bdrv_file_open(&s->hd, filename, flags);

    if (ret < 0)

        return ret;

    if (bdrv_pread(s->hd, 0, &magic, sizeof(magic)) != sizeof(magic))

        goto fail;

    magic = be32_to_cpu(magic);

    if (magic == VMDK3_MAGIC) {

        VMDK3Header header;

        if (bdrv_pread(s->hd, sizeof(magic), &header, sizeof(header)) != sizeof(header))

            goto fail;

        s->cluster_sectors = le32_to_cpu(header.granularity);

        s->l2_size = 1 << 9;

        s->l1_size = 1 << 6;

        bs->total_sectors = le32_to_cpu(header.disk_sectors);

        s->l1_table_offset = le32_to_cpu(header.l1dir_offset) << 9;

        s->l1_backup_table_offset = 0;

        s->l1_entry_sectors = s->l2_size * s->cluster_sectors;

    } else if (magic == VMDK4_MAGIC) {

        VMDK4Header header;

        if (bdrv_pread(s->hd, sizeof(magic), &header, sizeof(header)) != sizeof(header))

            goto fail;

        bs->total_sectors = le64_to_cpu(header.capacity);

        s->cluster_sectors = le64_to_cpu(header.granularity);

        s->l2_size = le32_to_cpu(header.num_gtes_per_gte);

        s->l1_entry_sectors = s->l2_size * s->cluster_sectors;

        if (s->l1_entry_sectors <= 0)

            goto fail;

        s->l1_size = (bs->total_sectors + s->l1_entry_sectors - 1)

            / s->l1_entry_sectors;

        s->l1_table_offset = le64_to_cpu(header.rgd_offset) << 9;

        s->l1_backup_table_offset = le64_to_cpu(header.gd_offset) << 9;

        if (parent_open)

            s->is_parent = 1;

        else

            s->is_parent = 0;

        // try to open parent images, if exist

        if (vmdk_parent_open(bs, filename) != 0)

            goto fail;

        // write the CID once after the image creation

        s->parent_cid = vmdk_read_cid(bs,1);

    } else {

        goto fail;

    }

    /* read the L1 table */

    l1_size = s->l1_size * sizeof(uint32_t);

    s->l1_table = qemu_malloc(l1_size);

    if (!s->l1_table)

        goto fail;

    if (bdrv_pread(s->hd, s->l1_table_offset, s->l1_table, l1_size) != l1_size)

        goto fail;

    for(i = 0; i < s->l1_size; i++) {

        le32_to_cpus(&s->l1_table[i]);

    }

    if (s->l1_backup_table_offset) {

        s->l1_backup_table = qemu_malloc(l1_size);

        if (!s->l1_backup_table)

            goto fail;

        if (bdrv_pread(s->hd, s->l1_backup_table_offset, s->l1_backup_table, l1_size) != l1_size)

            goto fail;

        for(i = 0; i < s->l1_size; i++) {

            le32_to_cpus(&s->l1_backup_table[i]);

        }

    }

    s->l2_cache = qemu_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint32_t));

    if (!s->l2_cache)

        goto fail;

    return 0;

 fail:

    qemu_free(s->l1_backup_table);

    qemu_free(s->l1_table);

    qemu_free(s->l2_cache);

    bdrv_delete(s->hd);

    return -1;

}

static uint64_t get_cluster_offset(BlockDriverState *bs, VmdkMetaData *m_data,

                                   uint64_t offset, int allocate);

static int get_whole_cluster(BlockDriverState *bs, uint64_t cluster_offset,

                             uint64_t offset, int allocate)

{

    uint64_t parent_cluster_offset;

    BDRVVmdkState *s = bs->opaque;

    uint8_t  whole_grain[s->cluster_sectors*512];        // 128 sectors * 512 bytes each = grain size 64KB

    // we will be here if it's first write on non-exist grain(cluster).

    // try to read from parent image, if exist

    if (s->hd->backing_hd) {

        BDRVVmdkState *ps = s->hd->backing_hd->opaque;

        if (!vmdk_is_cid_valid(bs))

            return -1;

        parent_cluster_offset = get_cluster_offset(s->hd->backing_hd, NULL, offset, allocate);

        if (parent_cluster_offset) {

            BDRVVmdkState *act_s = activeBDRV.hd->opaque;

            if (bdrv_pread(ps->hd, parent_cluster_offset, whole_grain, ps->cluster_sectors*512) != ps->cluster_sectors*512)

                return -1;

            //Write grain only into the active image

            if (bdrv_pwrite(act_s->hd, activeBDRV.cluster_offset << 9, whole_grain, sizeof(whole_grain)) != sizeof(whole_grain))

                return -1;

        }

    }

    return 0;

}

static int vmdk_L2update(BlockDriverState *bs, VmdkMetaData *m_data)

{

    BDRVVmdkState *s = bs->opaque;

    /* update L2 table */

    if (bdrv_pwrite(s->hd, ((int64_t)m_data->l2_offset * 512) + (m_data->l2_index * sizeof(m_data->offset)),

                    &(m_data->offset), sizeof(m_data->offset)) != sizeof(m_data->offset))

        return -1;

    /* update backup L2 table */

    if (s->l1_backup_table_offset != 0) {

        m_data->l2_offset = s->l1_backup_table[m_data->l1_index];

        if (bdrv_pwrite(s->hd, ((int64_t)m_data->l2_offset * 512) + (m_data->l2_index * sizeof(m_data->offset)),

                        &(m_data->offset), sizeof(m_data->offset)) != sizeof(m_data->offset))

            return -1;

    }

    return 0;

}

static uint64_t get_cluster_offset(BlockDriverState *bs, VmdkMetaData *m_data,

                                   uint64_t offset, int allocate)

{

    BDRVVmdkState *s = bs->opaque;

    unsigned int l1_index, l2_offset, l2_index;

    int min_index, i, j;

    uint32_t min_count, *l2_table, tmp = 0;

    uint64_t cluster_offset;

    if (m_data)

        m_data->valid = 0;