source: mainline/uspace/lib/label/src/gpt.c@ 3faa03d

/*
 * Copyright (c) 2015 Jiri Svoboda
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - 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.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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.
 */

/** @addtogroup liblabel
 * @{
 */
/**
 * @file GUID Partition Table label.
 */

#include <block.h>
#include <byteorder.h>
#include <errno.h>
#include <stdlib.h>

#include "std/gpt.h"
#include "gpt.h"

static int gpt_open(service_id_t, label_t **);
static int gpt_create(service_id_t, label_t **);
static void gpt_close(label_t *);
static int gpt_destroy(label_t *);
static label_part_t *gpt_part_first(label_t *);
static label_part_t *gpt_part_next(label_part_t *);
static void gpt_part_get_info(label_part_t *, label_part_info_t *);
static int gpt_part_create(label_t *, label_part_spec_t *, label_part_t **);
static int gpt_part_destroy(label_part_t *);

static int gpt_pte_to_part(label_t *, gpt_entry_t *);

const uint8_t efi_signature[8] = {
        /* "EFI PART" in ASCII */
        0x45, 0x46, 0x49, 0x20, 0x50, 0x41, 0x52, 0x54
};

label_ops_t gpt_label_ops = {
        .open = gpt_open,
        .create = gpt_create,
        .close = gpt_close,
        .destroy = gpt_destroy,
        .part_first = gpt_part_first,
        .part_next = gpt_part_next,
        .part_get_info = gpt_part_get_info,
        .part_create = gpt_part_create,
        .part_destroy = gpt_part_destroy
};

static int gpt_open(service_id_t sid, label_t **rlabel)
{
        label_t *label = NULL;
        gpt_header_t *gpt_hdr = NULL;
        gpt_entry_t *eptr;
        uint8_t *etable = NULL;
        size_t bsize;
        uint32_t num_entries;
        uint32_t esize;
        uint32_t bcnt;
        uint64_t ba;
        uint32_t entry;
        int i;
        int rc;

        rc = block_get_bsize(sid, &bsize);
        if (rc != EOK) {
                rc = EIO;
                goto error;
        }

        if (bsize < 512 || (bsize % 512) != 0) {
                rc = EINVAL;
                goto error;
        }

        gpt_hdr = calloc(1, bsize);
        if (gpt_hdr == NULL) {
                rc = ENOMEM;
                goto error;
        }

        rc = block_read_direct(sid, GPT_HDR_BA, 1, gpt_hdr);
        if (rc != EOK) {
                rc = EIO;
                goto error;
        }

        label = calloc(1, sizeof(label_t));
        if (label == NULL)
                return ENOMEM;

        list_initialize(&label->parts);

        for (i = 0; i < 8; ++i) {
                if (gpt_hdr->efi_signature[i] != efi_signature[i]) {
                        rc = EINVAL;
                        goto error;
                }
        }

        num_entries = uint32_t_le2host(gpt_hdr->num_entries);
        esize = uint32_t_le2host(gpt_hdr->entry_size);
        bcnt = (num_entries + esize - 1) / esize;
        ba = uint64_t_le2host(gpt_hdr->entry_lba);

        if (num_entries < 1) {
                rc = EINVAL;
                goto error;
        }

        if (esize < sizeof(gpt_entry_t)) {
                rc = EINVAL;
                goto error;
        }

        etable = calloc(num_entries, esize);
        if (etable == NULL) {
                rc = ENOMEM;
                goto error;
        }

        rc = block_read_direct(sid, ba, bcnt, etable);
        if (rc != EOK) {
                rc = EIO;
                goto error;
        }

        for (entry = 0; entry < num_entries; entry++) {
                eptr = (gpt_entry_t *)(etable + entry * esize);
                rc = gpt_pte_to_part(label, eptr);
                if (rc != EOK)
                        goto error;
        }

        free(etable);
        etable = NULL;
        free(gpt_hdr);
        gpt_hdr = NULL;

        label->ops = &gpt_label_ops;
        label->ltype = lt_gpt;
        *rlabel = label;
        return EOK;
error:
        free(etable);
        free(gpt_hdr);
        free(label);
        return rc;
}

static int gpt_create(service_id_t sid, label_t **rlabel)
{
        return EOK;
}

static void gpt_close(label_t *label)
{
        free(label);
}

static int gpt_destroy(label_t *label)
{
        return EOK;
}

static label_part_t *gpt_part_first(label_t *label)
{
        link_t *link;

        link = list_first(&label->parts);
        if (link == NULL)
                return NULL;

        return list_get_instance(link, label_part_t, llabel);
}

static label_part_t *gpt_part_next(label_part_t *part)
{
        link_t *link;

        link = list_next(&part->llabel, &part->label->parts);
        if (link == NULL)
                return NULL;

        return list_get_instance(link, label_part_t, llabel);
}

static void gpt_part_get_info(label_part_t *part, label_part_info_t *pinfo)
{
        pinfo->block0 = part->block0;
        pinfo->nblocks = part->nblocks;
}

static int gpt_part_create(label_t *label, label_part_spec_t *pspec,
    label_part_t **rpart)
{
        return EOK;
}

static int gpt_part_destroy(label_part_t *part)
{
        return EOK;
}

static int gpt_pte_to_part(label_t *label, gpt_entry_t *pte)
{
        label_part_t *part;
        bool present;
        uint64_t b0, b1;
        int i;

        present = false;
        for (i = 0; i < 8; i++)
                if (pte->part_type[i] != 0x00)
                        present = true;

        if (!present)
                return EOK;

        part = calloc(1, sizeof(label_part_t));
        if (part == NULL)
                return ENOMEM;

        b0 = uint64_t_le2host(pte->start_lba);
        b1 = uint64_t_le2host(pte->end_lba);
        if (b1 <= b0)
                return EINVAL;

        part->block0 = b0;
        part->nblocks = b1 - b0 + 1;

        part->label = label;
        list_append(&part->llabel, &label->parts);
        return EOK;
}

/** @}
 */