/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2014 Juniper Networks, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
#include <sys/errno.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "endian.h"
#include "image.h"
#include "format.h"
#include "mkimg.h"

#define VMDK_IMAGE_ROUND        1048576
#define VMDK_MIN_GRAIN_SIZE     8192
#define VMDK_SECTOR_SIZE        512

struct vmdk_header {
        uint32_t        magic;
#define VMDK_MAGIC              0x564d444b
        uint32_t        version;
#define VMDK_VERSION            1
        uint32_t        flags;
#define VMDK_FLAGS_NL_TEST      (1 << 0)
#define VMDK_FLAGS_RGT_USED     (1 << 1)
#define VMDK_FLAGS_COMPRESSED   (1 << 16)
#define VMDK_FLAGS_MARKERS      (1 << 17)
        uint64_t        capacity;
        uint64_t        grain_size;
        uint64_t        desc_offset;
        uint64_t        desc_size;
        uint32_t        ngtes;
#define VMDK_NGTES              512
        uint64_t        rgd_offset;
        uint64_t        gd_offset;
        uint64_t        overhead;
        uint8_t         unclean;
        uint32_t        nl_test;
#define VMDK_NL_TEST            0x0a200d0a
        uint16_t        compress;
#define VMDK_COMPRESS_NONE      0
#define VMDK_COMPRESS_DEFLATE   1
        char            padding[433];
} __attribute__((__packed__));

static const char desc_fmt[] =
    "# Disk DescriptorFile\n"
    "version=%d\n"
    "CID=%08x\n"
    "parentCID=ffffffff\n"
    "createType=\"monolithicSparse\"\n"
    "# Extent description\n"
    "RW %ju SPARSE \"%s\"\n"
    "# The Disk Data Base\n"
    "#DDB\n"
    "ddb.adapterType = \"ide\"\n"
    "ddb.geometry.cylinders = \"%u\"\n"
    "ddb.geometry.heads = \"%u\"\n"
    "ddb.geometry.sectors = \"%u\"\n";

static uint64_t grainsz;

static int
vmdk_resize(lba_t imgsz)
{
        uint64_t imagesz;

        imagesz = imgsz * secsz;
        imagesz = (imagesz + VMDK_IMAGE_ROUND - 1) & ~(VMDK_IMAGE_ROUND - 1);
        grainsz = (blksz < VMDK_MIN_GRAIN_SIZE) ? VMDK_MIN_GRAIN_SIZE : blksz;

        if (verbose)
                fprintf(stderr, "VMDK: image size = %ju, grain size = %ju\n",
                    (uintmax_t)imagesz, (uintmax_t)grainsz);

        grainsz /= VMDK_SECTOR_SIZE;
        return (image_set_size(imagesz / secsz));
}

static int
vmdk_write(int fd)
{
        struct vmdk_header hdr;
        uint32_t *gt, *gd, *rgd;
        char *buf, *desc;
        off_t cur, lim;
        uint64_t imagesz;
        lba_t blkofs, blkcnt;
        size_t gdsz, gtsz;
        uint32_t sec, cursec;
        int error, desc_len, n, ngrains, ngts;

        imagesz = (image_get_size() * secsz) / VMDK_SECTOR_SIZE;

        memset(&hdr, 0, sizeof(hdr));
        le32enc(&hdr.magic, VMDK_MAGIC);
        le32enc(&hdr.version, VMDK_VERSION);
        le32enc(&hdr.flags, VMDK_FLAGS_NL_TEST | VMDK_FLAGS_RGT_USED);
        le64enc(&hdr.capacity, imagesz);
        le64enc(&hdr.grain_size, grainsz);

        n = asprintf(&desc, desc_fmt, 1 /*version*/, 0 /*CID*/,
            (uintmax_t)imagesz /*size*/, "" /*name*/,
            ncyls /*cylinders*/, nheads /*heads*/, nsecs /*sectors*/);
        if (n == -1)
                return (ENOMEM);

        desc_len = (n + VMDK_SECTOR_SIZE - 1) & ~(VMDK_SECTOR_SIZE - 1);
        desc = realloc(desc, desc_len);
        memset(desc + n, 0, desc_len - n);

        le64enc(&hdr.desc_offset, 1);
        le64enc(&hdr.desc_size, desc_len / VMDK_SECTOR_SIZE);
        le32enc(&hdr.ngtes, VMDK_NGTES);

        sec = desc_len / VMDK_SECTOR_SIZE + 1;

        ngrains = imagesz / grainsz;
        ngts = (ngrains + VMDK_NGTES - 1) / VMDK_NGTES;
        gdsz = (ngts * sizeof(uint32_t) + VMDK_SECTOR_SIZE - 1) &
            ~(VMDK_SECTOR_SIZE - 1);

        gd = calloc(1, gdsz);
        if (gd == NULL) {
                free(desc);
                return (ENOMEM);
        }
        le64enc(&hdr.gd_offset, sec);
        sec += gdsz / VMDK_SECTOR_SIZE;
        for (n = 0; n < ngts; n++) {
                le32enc(gd + n, sec);
                sec += VMDK_NGTES * sizeof(uint32_t) / VMDK_SECTOR_SIZE;
        }

        rgd = calloc(1, gdsz);
        if (rgd == NULL) {
                free(gd);
                free(desc);
                return (ENOMEM);
        }
        le64enc(&hdr.rgd_offset, sec);
        sec += gdsz / VMDK_SECTOR_SIZE;
        for (n = 0; n < ngts; n++) {
                le32enc(rgd + n, sec);
                sec += VMDK_NGTES * sizeof(uint32_t) / VMDK_SECTOR_SIZE;
        }

        sec = (sec + grainsz - 1) & ~(grainsz - 1);

        if (verbose)
                fprintf(stderr, "VMDK: overhead = %ju\n",
                    (uintmax_t)(sec * VMDK_SECTOR_SIZE));

        le64enc(&hdr.overhead, sec);
        be32enc(&hdr.nl_test, VMDK_NL_TEST);

        gt = calloc(ngts, VMDK_NGTES * sizeof(uint32_t));
        if (gt == NULL) {
                free(rgd);
                free(gd);
                free(desc);
                return (ENOMEM);
        }
        gtsz = ngts * VMDK_NGTES * sizeof(uint32_t);

        cursec = sec;
        blkcnt = (grainsz * VMDK_SECTOR_SIZE) / secsz;
        for (n = 0; n < ngrains; n++) {
                blkofs = n * blkcnt;
                if (image_data(blkofs, blkcnt)) {
                        le32enc(gt + n, cursec);
                        cursec += grainsz;
                }
        }

        error = 0;
        if (!error && sparse_write(fd, &hdr, VMDK_SECTOR_SIZE) < 0)
                error = errno;
        if (!error && sparse_write(fd, desc, desc_len) < 0)
                error = errno;
        if (!error && sparse_write(fd, gd, gdsz) < 0)
                error = errno;
        if (!error && sparse_write(fd, gt, gtsz) < 0)
                error = errno;
        if (!error && sparse_write(fd, rgd, gdsz) < 0)
                error = errno;
        if (!error && sparse_write(fd, gt, gtsz) < 0)
                error = errno;
        free(gt);
        free(rgd);
        free(gd);
        free(desc);
        if (error)
                return (error);

        cur = VMDK_SECTOR_SIZE + desc_len + (gdsz + gtsz) * 2;
        lim = sec * VMDK_SECTOR_SIZE;
        if (cur < lim) {
                buf = calloc(1, VMDK_SECTOR_SIZE);
                if (buf == NULL)
                        error = ENOMEM;
                while (!error && cur < lim) {
                        if (sparse_write(fd, buf, VMDK_SECTOR_SIZE) < 0)
                                error = errno;
                        cur += VMDK_SECTOR_SIZE;
                }
                if (buf != NULL)
                        free(buf);
        }
        if (error)
                return (error);

        blkcnt = (grainsz * VMDK_SECTOR_SIZE) / secsz;
        for (n = 0; n < ngrains; n++) {
                blkofs = n * blkcnt;
                if (image_data(blkofs, blkcnt)) {
                        error = image_copyout_region(fd, blkofs, blkcnt);
                        if (error)
                                return (error);
                }
        }
        return (image_copyout_done(fd));
}

static struct mkimg_format vmdk_format = {
        .name = "vmdk",
        .description = "Virtual Machine Disk",
        .resize = vmdk_resize,
        .write = vmdk_write,
};

FORMAT_DEFINE(vmdk_format);