/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

 * Copyright by The HDF Group.                                               *

 * All rights reserved.                                                      *

 *                                                                           *

 * This file is part of HDF5.  The full HDF5 copyright notice, including     *

 * terms governing use, modification, and redistribution, is contained in    *

 * the LICENSE file, which can be found at the root of the source code       *

 * distribution tree, or in https://www.hdfgroup.org/licenses.               *

 * If you do not have access to either file, you may request a copy from     *

 * help@hdfgroup.org.                                                        *

 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/*

 * Onion Virtual File Driver (VFD)

 *

 * Purpose:     Code for the onion file's header

 */

#include "H5FDmodule.h" /* This source code file is part of the H5FD module */

#include "H5private.h"      /* Generic Functions                        */

#include "H5Eprivate.h"     /* Error handling                           */

#include "H5FDpkg.h"        /* File drivers                             */

#include "H5FDonion_priv.h" /* Onion file driver internals              */

#include "H5MMprivate.h"    /* Memory management                        */

/*-----------------------------------------------------------------------------

 * Function:    H5FD_ingest_header

 *

 * Purpose:     Read and decode the history header information from `raw_file`

 *              at `addr`, and store the decoded information in the structure

 *              at `hdr_out`.

 *

 * Return:      SUCCEED/FAIL

 *-----------------------------------------------------------------------------

 */

herr_t

H5FD__onion_ingest_header(H5FD_onion_header_t *hdr_out, H5FD_t *raw_file, haddr_t addr)

{

    unsigned char *buf       = NULL;

    herr_t         ret_value = SUCCEED;

    haddr_t        size      = (haddr_t)H5FD_ONION_ENCODED_SIZE_HEADER;

    uint32_t       sum       = 0;

    FUNC_ENTER_PACKAGE

    if (H5FD_get_eof(raw_file, H5FD_MEM_DRAW) < (addr + size))

        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "header indicates history beyond EOF");

    if (NULL == (buf = H5MM_malloc(sizeof(char) * size)))

        HGOTO_ERROR(H5E_VFL, H5E_CANTALLOC, FAIL, "can't allocate buffer space");

    if (H5FD_set_eoa(raw_file, H5FD_MEM_DRAW, (addr + size)) < 0)

        HGOTO_ERROR(H5E_VFL, H5E_CANTSET, FAIL, "can't modify EOA");

    if (H5FD_read(raw_file, H5FD_MEM_DRAW, addr, size, buf) < 0)

        HGOTO_ERROR(H5E_VFL, H5E_READERROR, FAIL, "can't read history header from file");

    if (H5FD__onion_header_decode(buf, hdr_out) == 0)

        HGOTO_ERROR(H5E_VFL, H5E_CANTDECODE, FAIL, "can't decode history header");

    sum = H5_checksum_fletcher32(buf, size - 4);

    if (hdr_out->checksum != sum)

        HGOTO_ERROR(H5E_VFL, H5E_BADVALUE, FAIL, "checksum mismatch between buffer and stored");

done:

    H5MM_xfree(buf);

    FUNC_LEAVE_NOAPI(ret_value)

} /* end H5FD__onion_ingest_header() */

/*-------------------------------------------------------------------------

 * Function:    H5FD__onion_write_header

 *

 * Purpose:     Write in-memory history header to appropriate backing file.

 *              Overwrites existing header data.

 *

 * Return:      SUCCEED/FAIL

 *-------------------------------------------------------------------------

 */

herr_t

H5FD__onion_write_header(H5FD_onion_header_t *header, H5FD_t *file)

{

    uint32_t       sum       = 0; /* Not used, but required by the encoder */

    uint64_t       size      = 0;

    unsigned char *buf       = NULL;

    herr_t         ret_value = SUCCEED;

    FUNC_ENTER_PACKAGE

    if (NULL == (buf = H5MM_malloc(H5FD_ONION_ENCODED_SIZE_HEADER)))

        HGOTO_ERROR(H5E_VFL, H5E_CANTALLOC, FAIL, "can't allocate buffer for updated history header");

    if (0 == (size = H5FD__onion_header_encode(header, buf, &sum)))

        HGOTO_ERROR(H5E_VFL, H5E_BADVALUE, FAIL, "problem encoding updated history header");

    if (H5FD_write(file, H5FD_MEM_DRAW, 0, (haddr_t)size, buf) < 0)

        HGOTO_ERROR(H5E_VFL, H5E_WRITEERROR, FAIL, "can't write updated history header");

done:

    H5MM_xfree(buf);

    FUNC_LEAVE_NOAPI(ret_value)

} /* end H5FD__onion_write_header()*/

/*-----------------------------------------------------------------------------

 * Function:    H5FD__onion_header_decode

 *

 * Purpose:     Attempt to read a buffer and store it as a history-header

 *              structure.

 *

 *              Implementation must correspond with

 *              H5FD__onion_header_encode().

 *

 * Return:      Success:    Number of bytes read from buffer

 *              Failure:    0

 *-----------------------------------------------------------------------------

 */

size_t

H5FD__onion_header_decode(unsigned char *buf, H5FD_onion_header_t *header)

{

    uint32_t       ui32      = 0;

    uint32_t       sum       = 0;

    uint64_t       ui64      = 0;

    uint8_t       *ui8p      = NULL;

    unsigned char *ptr       = NULL;

    size_t         ret_value = 0;

    FUNC_ENTER_PACKAGE

    assert(buf != NULL);

    assert(header != NULL);

    assert(H5FD_ONION_HEADER_VERSION_CURR == header->version);

    if (strncmp((const char *)buf, H5FD_ONION_HEADER_SIGNATURE, 4))

        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, 0, "invalid header signature");

    if (buf[4] != H5FD_ONION_HEADER_VERSION_CURR)

        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, 0, "invalid header version");

    ptr  = buf + 5;

    ui32 = 0;

    H5MM_memcpy(&ui32, ptr, 3);

    ui8p = (uint8_t *)&ui32;

    UINT32DECODE(ui8p, header->flags);

    ptr += 3;

    H5MM_memcpy(&ui32, ptr, 4);

    ui8p = (uint8_t *)&ui32;

    UINT32DECODE(ui8p, header->page_size);

    ptr += 4;

    H5MM_memcpy(&ui64, ptr, 8);

    ui8p = (uint8_t *)&ui64;

    UINT32DECODE(ui8p, header->origin_eof);

    ptr += 8;

    H5MM_memcpy(&ui64, ptr, 8);

    ui8p = (uint8_t *)&ui64;

    UINT32DECODE(ui8p, header->history_addr);

    ptr += 8;

    H5MM_memcpy(&ui64, ptr, 8);

    ui8p = (uint8_t *)&ui64;

    UINT32DECODE(ui8p, header->history_size);

    ptr += 8;

    sum = H5_checksum_fletcher32(buf, (size_t)(ptr - buf));

    H5MM_memcpy(&ui32, ptr, 4);

    ui8p = (uint8_t *)&ui32;

    UINT32DECODE(ui8p, header->checksum);

    ptr += 4;

    if (sum != header->checksum)

        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, 0, "checksum mismatch");

    ret_value = (size_t)(ptr - buf);

done:

    FUNC_LEAVE_NOAPI(ret_value)

} /* end H5FD__onion_header_decode() */

/*-----------------------------------------------------------------------------

 * Function:    H5FD__onion_header_encode

 *

 * Purpose:     Write history-header structure to the given buffer.

 *              All multi-byte elements are stored in little-endian word order.

 *

 *              Implementation must correspond with

 *              H5FD__onion_header_decode().

 *

 *              The destination buffer must be sufficiently large to hold the

 *              encoded contents (H5FD_ONION_ENCODED_SIZE_HEADER).

 *

 * Return:      Number of bytes written to buffer.

 *              The checksum of the generated buffer contents (excluding the

 *              checksum itself) is stored in the pointer `checksum`).

 *-----------------------------------------------------------------------------

 */

size_t

H5FD__onion_header_encode(H5FD_onion_header_t *header, unsigned char *buf, uint32_t *checksum /*out*/)

{

    unsigned char *ptr       = buf;

    size_t         ret_value = 0;

    FUNC_ENTER_PACKAGE_NOERR

    assert(buf != NULL);

    assert(checksum != NULL);

    assert(header != NULL);

    assert(H5FD_ONION_HEADER_VERSION_CURR == header->version);

    assert(0 == (header->flags & 0xFF000000)); /* max three bits long */

    H5MM_memcpy(ptr, H5FD_ONION_HEADER_SIGNATURE, 4);

    ptr += 4;

    H5MM_memcpy(ptr, (unsigned char *)&header->version, 1);

    ptr += 1;

    UINT32ENCODE(ptr, header->flags);

    ptr -= 1; /* truncate to three bytes */

    UINT32ENCODE(ptr, header->page_size);

    UINT64ENCODE(ptr, header->origin_eof);

    UINT64ENCODE(ptr, header->history_addr);

    UINT64ENCODE(ptr, header->history_size);

    *checksum = H5_checksum_fletcher32(buf, (size_t)(ptr - buf));

    UINT32ENCODE(ptr, *checksum);

    ret_value = (size_t)(ptr - buf);

    FUNC_LEAVE_NOAPI(ret_value)

} /* end H5FD__onion_header_encode() */