/*-
 * 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/param.h>
#include <sys/errno.h>
#include <stddef.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>

#include <gpt.h>
#include <mbr.h>

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

static mkimg_uuid_t gpt_uuid_efi = GPT_ENT_TYPE_EFI;
static mkimg_uuid_t gpt_uuid_freebsd = GPT_ENT_TYPE_FREEBSD;
static mkimg_uuid_t gpt_uuid_freebsd_boot = GPT_ENT_TYPE_FREEBSD_BOOT;
static mkimg_uuid_t gpt_uuid_freebsd_nandfs = GPT_ENT_TYPE_FREEBSD_NANDFS;
static mkimg_uuid_t gpt_uuid_freebsd_swap = GPT_ENT_TYPE_FREEBSD_SWAP;
static mkimg_uuid_t gpt_uuid_freebsd_ufs = GPT_ENT_TYPE_FREEBSD_UFS;
static mkimg_uuid_t gpt_uuid_freebsd_vinum = GPT_ENT_TYPE_FREEBSD_VINUM;
static mkimg_uuid_t gpt_uuid_freebsd_zfs = GPT_ENT_TYPE_FREEBSD_ZFS;
static mkimg_uuid_t gpt_uuid_mbr = GPT_ENT_TYPE_MBR;
static mkimg_uuid_t gpt_uuid_ms_basic_data = GPT_ENT_TYPE_MS_BASIC_DATA;
static mkimg_uuid_t gpt_uuid_prep_boot = GPT_ENT_TYPE_PREP_BOOT;

static struct mkimg_alias gpt_aliases[] = {
    {   ALIAS_EFI, ALIAS_PTR2TYPE(&gpt_uuid_efi) },
    {   ALIAS_FREEBSD, ALIAS_PTR2TYPE(&gpt_uuid_freebsd) },
    {   ALIAS_FREEBSD_BOOT, ALIAS_PTR2TYPE(&gpt_uuid_freebsd_boot) },
    {   ALIAS_FREEBSD_NANDFS, ALIAS_PTR2TYPE(&gpt_uuid_freebsd_nandfs) },
    {   ALIAS_FREEBSD_SWAP, ALIAS_PTR2TYPE(&gpt_uuid_freebsd_swap) },
    {   ALIAS_FREEBSD_UFS, ALIAS_PTR2TYPE(&gpt_uuid_freebsd_ufs) },
    {   ALIAS_FREEBSD_VINUM, ALIAS_PTR2TYPE(&gpt_uuid_freebsd_vinum) },
    {   ALIAS_FREEBSD_ZFS, ALIAS_PTR2TYPE(&gpt_uuid_freebsd_zfs) },
    {   ALIAS_MBR, ALIAS_PTR2TYPE(&gpt_uuid_mbr) },
    {   ALIAS_NTFS, ALIAS_PTR2TYPE(&gpt_uuid_ms_basic_data) },
    {   ALIAS_PPCBOOT, ALIAS_PTR2TYPE(&gpt_uuid_prep_boot) },
    {   ALIAS_NONE, 0 }         /* Keep last! */
};

/* CRC32 code derived from work by Gary S. Brown. */
static const uint32_t crc32_tab[] = {
        0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,
        0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
        0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2,
        0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
        0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
        0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
        0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c,
        0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
        0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423,
        0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
        0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x01db7106,
        0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
        0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d,
        0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
        0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
        0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
        0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7,
        0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
        0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa,
        0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
        0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81,
        0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
        0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84,
        0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
        0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
        0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
        0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e,
        0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
        0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55,
        0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
        0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28,
        0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
        0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f,
        0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
        0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
        0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
        0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69,
        0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
        0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc,
        0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
        0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693,
        0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
        0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
};

static uint32_t
crc32(const void *buf, size_t sz)
{
        const uint8_t *p = (const uint8_t *)buf;
        uint32_t crc = ~0U;

        while (sz--)
                crc = crc32_tab[(crc ^ *p++) & 0xff] ^ (crc >> 8);
        return (crc ^ ~0U);
}

/*
 * Return the number of sectors needed to store the partition table.
 */
static u_int
gpt_tblsz(void)
{
        u_int eps;              /* Entries per Sector */

        /*
         * Count the number of sectors needed for the GPT Entry Array to store
         * the number of partitions defined for this image.  Enforce the 16kB
         * minimum space for the GPT Entry Array per UEFI v2.10 Section 5.3.
         */
        eps = secsz / sizeof(struct gpt_ent);
        return (MAX(howmany(GPT_MIN_RESERVED, secsz), howmany(nparts, eps)));
}

static lba_t
gpt_metadata(u_int where, lba_t blk)
{

        if (where == SCHEME_META_IMG_START || where == SCHEME_META_IMG_END) {
                blk += gpt_tblsz();
                blk += (where == SCHEME_META_IMG_START) ? 2 : 1;
        }
        return (round_block(blk));
}

static int
gpt_write_pmbr(lba_t blks, void *bootcode)
{
        u_char *pmbr;
        uint32_t secs;
        int error;

        secs = (blks > UINT32_MAX) ? UINT32_MAX : (uint32_t)blks - 1;

        pmbr = malloc(secsz);
        if (pmbr == NULL)
                return (errno);
        if (bootcode != NULL) {
                memcpy(pmbr, bootcode, DOSPARTOFF);
                memset(pmbr + DOSPARTOFF, 0, secsz - DOSPARTOFF);
        } else
                memset(pmbr, 0, secsz);
        pmbr[DOSPARTOFF + 2] = 2;
        pmbr[DOSPARTOFF + 4] = 0xee;
        pmbr[DOSPARTOFF + 5] = 0xff;
        pmbr[DOSPARTOFF + 6] = 0xff;
        pmbr[DOSPARTOFF + 7] = 0xff;
        le32enc(pmbr + DOSPARTOFF + 8, 1);
        le32enc(pmbr + DOSPARTOFF + 12, secs);
        le16enc(pmbr + DOSMAGICOFFSET, DOSMAGIC);
        error = image_write(0, pmbr, 1);
        free(pmbr);
        return (error);
}

static struct gpt_ent *
gpt_mktbl(u_int tblsz)
{
        mkimg_uuid_t uuid;
        struct gpt_ent *tbl, *ent;
        struct part *part;
        int c, idx;

        tbl = calloc(tblsz, secsz);
        if (tbl == NULL)
                return (NULL);

        TAILQ_FOREACH(part, &partlist, link) {
                ent = tbl + part->index;
                mkimg_uuid_enc(&ent->ent_type, ALIAS_TYPE2PTR(part->type));
                mkimg_uuid(&uuid);
                mkimg_uuid_enc(&ent->ent_uuid, &uuid);
                le64enc(&ent->ent_lba_start, part->block);
                le64enc(&ent->ent_lba_end, part->block + part->size - 1);
                if (part->label != NULL) {
                        idx = 0;
                        while ((c = part->label[idx]) != '\0') {
                                le16enc(ent->ent_name + idx, c);
                                idx++;
                        }
                }
        }
        return (tbl);
}

static int
gpt_write_hdr(struct gpt_hdr *hdr, uint64_t self, uint64_t alt, uint64_t tbl)
{
        uint32_t crc;

        le64enc(&hdr->hdr_lba_self, self);
        le64enc(&hdr->hdr_lba_alt, alt);
        le64enc(&hdr->hdr_lba_table, tbl);
        hdr->hdr_crc_self = 0;
        crc = crc32(hdr, offsetof(struct gpt_hdr, padding));
        le64enc(&hdr->hdr_crc_self, crc);
        return (image_write(self, hdr, 1));
}

static int
gpt_write(lba_t imgsz, void *bootcode)
{
        mkimg_uuid_t uuid;
        struct gpt_ent *tbl;
        struct gpt_hdr *hdr;
        uint32_t crc;
        u_int tblsz;
        int error;

        /* PMBR */
        error = gpt_write_pmbr(imgsz, bootcode);
        if (error)
                return (error);

        /* GPT table(s) */
        tblsz = gpt_tblsz();
        tbl = gpt_mktbl(tblsz);
        if (tbl == NULL)
                return (errno);
        error = image_write(2, tbl, tblsz);
        if (error)
                goto out;
        error = image_write(imgsz - (tblsz + 1), tbl, tblsz);
        if (error)
                goto out;

        /* GPT header(s) */
        hdr = malloc(secsz);
        if (hdr == NULL) {
                error = errno;
                goto out;
        }
        memset(hdr, 0, secsz);
        memcpy(hdr->hdr_sig, GPT_HDR_SIG, sizeof(hdr->hdr_sig));
        le32enc(&hdr->hdr_revision, GPT_HDR_REVISION);
        le32enc(&hdr->hdr_size, offsetof(struct gpt_hdr, padding));
        le64enc(&hdr->hdr_lba_start, 2 + tblsz);
        le64enc(&hdr->hdr_lba_end, imgsz - tblsz - 2);
        mkimg_uuid(&uuid);
        mkimg_uuid_enc(&hdr->hdr_uuid, &uuid);
        le32enc(&hdr->hdr_entries, tblsz * secsz / sizeof(struct gpt_ent));
        le32enc(&hdr->hdr_entsz, sizeof(struct gpt_ent));
        crc = crc32(tbl, tblsz * secsz);
        le32enc(&hdr->hdr_crc_table, crc);
        error = gpt_write_hdr(hdr, 1, imgsz - 1, 2);
        if (!error)
                error = gpt_write_hdr(hdr, imgsz - 1, 1, imgsz - tblsz - 1);
        free(hdr);

 out:
        free(tbl);
        return (error);
}

static struct mkimg_scheme gpt_scheme = {
        .name = "gpt",
        .description = "GUID Partition Table",
        .aliases = gpt_aliases,
        .metadata = gpt_metadata,
        .write = gpt_write,
        .nparts = 4096,
        .labellen = 36,
        .bootcode = 512,
        .maxsecsz = 4096
};

SCHEME_DEFINE(gpt_scheme);