index_v1.c

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/*
 * This file is part of the Aaru Data Preservation Suite.
 * Copyright (c) 2019-2025 Natalia Portillo.
 *
 * This library is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of the
 * License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
 */
 
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
 
#include "aaruformat.h"
#include "log.h"
#include "utarray.h"

UT_array *process_index_v1(aaruformat_context *ctx)
{
    TRACE("Entering process_index_v1(%p)", ctx);
 
    UT_array  *index_entries = NULL;
    IndexEntry entry;
 
    if(ctx == NULL || ctx->imageStream == NULL) return NULL;
 
    // Initialize the index entries array
    const UT_icd index_entry_icd = {sizeof(IndexEntry), NULL, NULL, NULL};
 
    utarray_new(index_entries, &index_entry_icd);
 
    if(index_entries == NULL)
    {
        FATAL("Could not allocate memory for index entries array.");
        TRACE("Exiting process_index_v1() = NULL");
        return NULL;
    }
 
    // Read the index header
    TRACE("Reading index header at position %llu", ctx->header.indexOffset);
    if(fseek(ctx->imageStream, ctx->header.indexOffset, SEEK_SET) != 0)
    {
        FATAL("Could not seek to index header at %llu.", ctx->header.indexOffset);
        utarray_free(index_entries);
 
        TRACE("Exiting process_index_v1() = NULL");
        return NULL;
    }
 
    IndexHeader idx_header;
    if(fread(&idx_header, sizeof(IndexHeader), 1, ctx->imageStream) != 1)
    {
        FATAL("Could not read index header at %llu.", ctx->header.indexOffset);
        utarray_free(index_entries);
 
        TRACE("Exiting process_index_v1() = NULL");
        return NULL;
    }
 
    // Check if the index header is valid
    if(idx_header.identifier != IndexBlock)
    {
        FATAL("Incorrect index identifier.");
        utarray_free(index_entries);
 
        TRACE("Exiting process_index_v1() = NULL");
        return NULL;
    }
 
    for(int i = 0; i < idx_header.entries; i++)
    {
        if(fread(&entry, sizeof(IndexEntry), 1, ctx->imageStream) != 1)
        {
            FATAL("Could not read index entry %d at %llu.", i, ctx->header.indexOffset);
            utarray_free(index_entries);
 
            TRACE("Exiting process_index_v1() = NULL");
            return NULL;
        }
 
        utarray_push_back(index_entries, &entry);
    }
 
    TRACE("Read %d index entries from index block at position %llu", idx_header.entries, ctx->header.indexOffset);
    return index_entries;
}

int32_t verify_index_v1(aaruformat_context *ctx)
{
    TRACE("Entering verify_index_v1(%p)", ctx);
 
    size_t      read_bytes = 0;
    IndexHeader index_header;
    uint64_t    crc64         = 0;
    IndexEntry *index_entries = NULL;
 
    if(ctx == NULL || ctx->imageStream == NULL)
    {
        FATAL("Invalid context or image stream.");
 
        TRACE("Exiting verify_index_v1() = AARUF_ERROR_NOT_AARUFORMAT");
        return AARUF_ERROR_NOT_AARUFORMAT;
    }
 
    // This will traverse all blocks and check their CRC64 without uncompressing them
    TRACE("Checking index integrity at %llu.", ctx->header.indexOffset);
    if(fseek(ctx->imageStream, ctx->header.indexOffset, SEEK_SET) != 0)
    {
        FATAL("Could not seek to index header at %llu.", ctx->header.indexOffset);
 
        TRACE("Exiting verify_index_v1() = AARUF_ERROR_CANNOT_READ_HEADER");
        return AARUF_ERROR_CANNOT_READ_HEADER;
    }
 
    // Read the index header
    TRACE("Reading index header at position %llu", ctx->header.indexOffset);
    read_bytes = fread(&index_header, 1, sizeof(IndexHeader), ctx->imageStream);
 
    if(read_bytes != sizeof(IndexHeader))
    {
        FATAL("Could not read index header.");
 
        TRACE("Exiting verify_index_v1() = AARUF_ERROR_CANNOT_READ_HEADER");
        return AARUF_ERROR_CANNOT_READ_HEADER;
    }
 
    if(index_header.identifier != IndexBlock)
    {
        FATAL("Incorrect index identifier.");
 
        TRACE("Exiting verify_index_v1() = AARUF_ERROR_CANNOT_READ_INDEX");
        return AARUF_ERROR_CANNOT_READ_INDEX;
    }
 
    TRACE("Index at %llu contains %d entries.", ctx->header.indexOffset, index_header.entries);
    fprintf(stderr, "Index at %llu contains %d entries.", ctx->header.indexOffset, index_header.entries);
 
    index_entries = malloc(sizeof(IndexEntry) * index_header.entries);
 
    if(index_entries == NULL)
    {
        FATAL("Cannot allocate memory for index entries.");
        return AARUF_ERROR_NOT_ENOUGH_MEMORY;
    }
 
    read_bytes = fread(index_entries, 1, sizeof(IndexEntry) * index_header.entries, ctx->imageStream);
 
    if(read_bytes != sizeof(IndexEntry) * index_header.entries)
    {
        FATAL("Could not read index entries.");
        free(index_entries);
 
        TRACE("Exiting verify_index_v1() = AARUF_ERROR_CANNOT_READ_INDEX");
        return AARUF_ERROR_CANNOT_READ_INDEX;
    }
 
    crc64 = aaruf_crc64_data((const uint8_t *)index_entries, sizeof(IndexEntry) * index_header.entries);
 
    // Due to how C# wrote it, it is effectively reversed
    if(ctx->header.imageMajorVersion <= AARUF_VERSION_V1) crc64 = bswap_64(crc64);
 
    if(crc64 != index_header.crc64)
    {
        FATAL("Expected index CRC 0x%16llX but got 0x%16llX.", index_header.crc64, crc64);
        free(index_entries);
 
        TRACE("Exiting verify_index_v1() = AARUF_ERROR_INVALID_BLOCK_CRC");
        return AARUF_ERROR_INVALID_BLOCK_CRC;
    }
 
    free(index_entries);
 
    TRACE("Exiting verify_index_v1() = AARUF_OK");
    return AARUF_STATUS_OK;
}