/*
 * Copyright (c) 2007 The DragonFly Project.  All rights reserved.
 *
 * This code is derived from software contributed to The DragonFly Project
 * by Matthew Dillon <dillon@backplane.com>
 *
 * 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.
 * 3. Neither the name of The DragonFly Project nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific, prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
 * COPYRIGHT HOLDERS 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/systm.h>
#include <sys/conf.h>
#include <sys/endian.h>
#include <sys/diskslice.h>
#include <sys/diskmbr.h>
#include <sys/disk.h>
#include <sys/buf.h>
#include <sys/malloc.h>
#include <sys/syslog.h>
#include <sys/bus.h>
#include <sys/device.h>
#include <sys/gpt.h>
#include <sys/uuid.h>

#define MAX_GPT_ENTRIES 128     /* max number of GPT entries */

static void gpt_setslice(const char *sname, struct disk_info *info,
                         struct diskslice *sp, const struct gpt_ent *sent);

/*
 * Handle GPT on raw disk.  Note that GPTs are not recursive.  The MBR is
 * ignored once a GPT has been detected.
 *
 * GPTs always start at block #1, regardless of how the MBR has been set up.
 * In fact, the MBR's starting block might be pointing to the boot partition
 * in the GPT rather then to the start of the GPT.
 *
 * This routine is called from mbrinit() when a GPT has been detected.
 */
int
gptinit(cdev_t dev, struct disk_info *info, struct diskslices **sspp)
{
        struct buf *bp1 = NULL;
        struct buf *bp2 = NULL;
        struct gpt_hdr *gpt;
        struct gpt_ent *ent;
        struct diskslice *sp;
        struct diskslices *ssp;
        cdev_t wdev;
        int error;
        uint32_t len;
        uint32_t entries;
        uint32_t entsz;
        uint32_t crc;
        uint32_t table_lba;
        uint32_t table_blocks;
        int i;
        const char *dname;

        error = 0;

        /*
         * The GPT starts in sector 1.
         */
        wdev = dev;
        dname = dev_dname(wdev);
        bp1 = getpbuf_mem(NULL);
        KKASSERT(info->d_media_blksize <= bp1->b_bufsize);
        bp1->b_bio1.bio_offset = info->d_media_blksize;
        bp1->b_bio1.bio_done = biodone_sync;
        bp1->b_bio1.bio_flags |= BIO_SYNC;
        bp1->b_bcount = info->d_media_blksize;
        bp1->b_cmd = BUF_CMD_READ;
        bp1->b_flags |= B_FAILONDIS;
        dev_dstrategy(wdev, &bp1->b_bio1);
        if (biowait(&bp1->b_bio1, "gptrd") != 0) {
                kprintf("%s: reading GPT @ block 1: error %d\n",
                        dname, bp1->b_error);
                error = EIO;
                goto done;
        }

        /*
         * Header sanity check
         */
        gpt = (void *)bp1->b_data;
        len = le32toh(gpt->hdr_size);
        if (len < GPT_MIN_HDR_SIZE || len > info->d_media_blksize) {
                kprintf("%s: Illegal GPT header size %d\n", dname, len);
                error = EINVAL;
                goto done;
        }

        crc = le32toh(gpt->hdr_crc_self);
        gpt->hdr_crc_self = 0;
        if (crc32(gpt, len) != crc) {
                kprintf("%s: GPT CRC32 did not match\n", dname);
                error = EINVAL;
                goto done;
        }

        /*
         * Validate the partition table and its location, then read it
         * into a buffer.
         */
        entries = le32toh(gpt->hdr_entries);
        entsz = le32toh(gpt->hdr_entsz);
        table_lba = le32toh(gpt->hdr_lba_table);
        table_blocks = (entries * entsz + info->d_media_blksize - 1) /
                       info->d_media_blksize;
        if (entries < 1 || entries > MAX_GPT_ENTRIES ||
            entsz < sizeof(struct gpt_ent) || (entsz & 7) ||
            entsz > MAXBSIZE / entries ||
            table_lba < 2 || table_lba + table_blocks > info->d_media_blocks)
        {
                kprintf("%s: GPT partition table is out of bounds\n", dname);
                error = EINVAL;
                goto done;
        }

        /*
         * XXX subject to device dma size limitations
         */
        bp2 = getpbuf_mem(NULL);
        KKASSERT((int)(table_blocks * info->d_media_blksize) <= bp2->b_bufsize);
        bp2->b_bio1.bio_offset = (off_t)table_lba * info->d_media_blksize;
        bp2->b_bio1.bio_done = biodone_sync;
        bp2->b_bio1.bio_flags |= BIO_SYNC;
        bp2->b_bcount = table_blocks * info->d_media_blksize;
        bp2->b_cmd = BUF_CMD_READ;
        bp2->b_flags |= B_FAILONDIS;
        dev_dstrategy(wdev, &bp2->b_bio1);
        if (biowait(&bp2->b_bio1, "gptrd") != 0) {
                kprintf("%s: reading GPT partition table @ %lld: error %d\n",
                        dname,
                        (long long)bp2->b_bio1.bio_offset,
                        bp2->b_error);
                error = EIO;
                goto done;
        }

        /*
         * We are passed a pointer to a minimal slices struct.  Replace
         * it with a maximal one (128 slices + special slices).  Well,
         * really there is only one special slice (the WHOLE_DISK_SLICE)
         * since we use the compatibility slice for s0, but don't quibble.
         *
         */
        kfree(*sspp, M_DEVBUF);
        ssp = *sspp = dsmakeslicestruct(BASE_SLICE + MAX_GPT_ENTRIES, info);

        /*
         * Create a slice for each partition.
         */
        for (i = 0; i < (int)entries && i < MAX_GPT_ENTRIES; ++i) {
                struct gpt_ent sent;
                char partname[2];
                char *sname;
                size_t j;

                ent = (void *)((char *)bp2->b_data + i * entsz);
                le_uuid_dec(&ent->ent_type, &sent.ent_type);
                le_uuid_dec(&ent->ent_uuid, &sent.ent_uuid);
                sent.ent_lba_start = le64toh(ent->ent_lba_start);
                sent.ent_lba_end = le64toh(ent->ent_lba_end);
                sent.ent_attr = le64toh(ent->ent_attr);

                for (j = 0; j < NELEM(ent->ent_name); ++j)
                        sent.ent_name[j] = le16toh(ent->ent_name[j]);

                /*
                 * The COMPATIBILITY_SLICE is actually slice 0 (s0).  This
                 * is a bit weird becaue the whole-disk slice is #1, so
                 * slice 1 (s1) starts at BASE_SLICE.
                 */
                if (i == 0)
                        sp = &ssp->dss_slices[COMPATIBILITY_SLICE];
                else
                        sp = &ssp->dss_slices[BASE_SLICE+i-1];
                sname = dsname(dev, dkunit(dev), WHOLE_DISK_SLICE,
                               WHOLE_SLICE_PART, partname);

                if (kuuid_is_nil(&sent.ent_type))
                        continue;

                if (sent.ent_lba_start < table_lba + table_blocks ||
                    sent.ent_lba_end >= info->d_media_blocks ||
                    sent.ent_lba_start > sent.ent_lba_end) {
                        kprintf("%s part %d: bad lba_start=%ju or "
                                "lba_end=%ju\n",
                                sname, i, (uintmax_t)sent.ent_lba_start,
                                (uintmax_t)sent.ent_lba_end);
                } else {
                        gpt_setslice(sname, info, sp, &sent);
                }
        }
        ssp->dss_nslices = BASE_SLICE + i;

done:
        if (bp1) {
                bp1->b_flags |= B_INVAL | B_AGE;
                relpbuf(bp1, NULL);
        }
        if (bp2) {
                bp2->b_flags |= B_INVAL | B_AGE;
                relpbuf(bp2, NULL);
        }
        return (error);
}

static void
gpt_setslice(const char *sname, struct disk_info *info, struct diskslice *sp,
             const struct gpt_ent *sent)
{
        static const struct {
                struct uuid     uuid;
                int             type;
        } slice_types[] = {
                { GPT_ENT_TYPE_DRAGONFLY_LABEL32,       DOSPTYP_DFLYBSD },
                { GPT_ENT_TYPE_DRAGONFLY_LABEL64,       DOSPTYP_DFLYBSD },
                { GPT_ENT_TYPE_DRAGONFLY_LEGACY,        DOSPTYP_DFLYBSD },
                { GPT_ENT_TYPE_FREEBSD,                 DOSPTYP_386BSD },
        };
        size_t i;

        for (i = 0; i < NELEM(slice_types); i++) {
                if (kuuid_compare(&slice_types[i].uuid, &sent->ent_type) == 0) {
                        sp->ds_type = slice_types[i].type;
                        break;
                }
        }

        sp->ds_offset = sent->ent_lba_start;
        sp->ds_size   = sent->ent_lba_end + 1 - sent->ent_lba_start;
        sp->ds_type_uuid = sent->ent_type;
        sp->ds_stor_uuid = sent->ent_uuid;
        sp->ds_reserved = 0;    /* no reserved sectors */
}