libaaruformat/src/read.c

/*
 * 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 <stdlib.h>
#include <string.h>

#include <aaruformat.h>

int32_t aaruf_read_media_tag(void *context, uint8_t *data, int32_t tag, uint32_t *length)
{
    aaruformatContext *ctx;
    mediaTagEntry     *item;

    if(context == NULL) return AARUF_ERROR_NOT_AARUFORMAT;

    ctx = context;

    // Not a libaaruformat context
    if(ctx->magic != AARU_MAGIC) return AARUF_ERROR_NOT_AARUFORMAT;

    HASH_FIND_INT(ctx->mediaTags, &tag, item);

    if(item == NULL)
    {
        *length = 0;
        return AARUF_ERROR_MEDIA_TAG_NOT_PRESENT;
    }

    if(data == NULL || *length < item->length)
    {
        *length = item->length;
        return AARUF_ERROR_BUFFER_TOO_SMALL;
    }

    *length = item->length;
    memcpy(data, item->data, item->length);

    return AARUF_STATUS_OK;
}

int32_t aaruf_read_sector(void *context, uint64_t sectorAddress, uint8_t *data, uint32_t *length)
{
    aaruformatContext *ctx = NULL;
    uint64_t ddtEntry = 0;
    uint32_t offsetMask = 0;
    uint64_t offset = 0;
    uint64_t blockOffset = 0;
    BlockHeader *blockHeader = NULL;
    uint8_t *block = NULL;
    size_t readBytes = 0;
    uint8_t            lzmaProperties[LZMA_PROPERTIES_LENGTH];
    size_t lzmaSize = 0;
    uint8_t *cmpData = NULL;
    int errorNo = 0;

    if(context == NULL) return AARUF_ERROR_NOT_AARUFORMAT;

    ctx = context;

    // Not a libaaruformat context
    if(ctx->magic != AARU_MAGIC) return AARUF_ERROR_NOT_AARUFORMAT;

    if(sectorAddress > ctx->imageInfo.Sectors - 1) return AARUF_ERROR_SECTOR_OUT_OF_BOUNDS;

    ddtEntry    = ctx->userDataDdt[sectorAddress];
    offsetMask  = (uint32_t)((1 << ctx->shift) - 1);
    offset      = ddtEntry & offsetMask;
    blockOffset = ddtEntry >> ctx->shift;

    // Partially written image... as we can't know the real sector size just assume it's common :/
    if(ddtEntry == 0)
    {
        memset(data, 0, ctx->imageInfo.SectorSize);
        *length = ctx->imageInfo.SectorSize;
        return AARUF_STATUS_SECTOR_NOT_DUMPED;
    }

    // Check if block header is cached
    blockHeader = find_in_cache_uint64(&ctx->blockHeaderCache, blockOffset);

    // Read block header
    if(blockHeader == NULL)
    {
        blockHeader = malloc(sizeof(BlockHeader));
        if(blockHeader == NULL) return AARUF_ERROR_NOT_ENOUGH_MEMORY;

        fseek(ctx->imageStream, blockOffset, SEEK_SET);
        readBytes = fread(blockHeader, 1, sizeof(BlockHeader), ctx->imageStream);

        if(readBytes != sizeof(BlockHeader)) return AARUF_ERROR_CANNOT_READ_HEADER;

        add_to_cache_uint64(&ctx->blockHeaderCache, blockOffset, blockHeader);
    }
    else
        fseek(ctx->imageStream, blockOffset + sizeof(BlockHeader), SEEK_SET);  // Advance as if reading the header

    if(data == NULL || *length < blockHeader->sectorSize)
    {
        *length = blockHeader->sectorSize;
        return AARUF_ERROR_BUFFER_TOO_SMALL;
    }

    // Check if block is cached
    block = find_in_cache_uint64(&ctx->blockCache, blockOffset);

    if(block != NULL)
    {
        memcpy(data, block + offset, blockHeader->sectorSize);
        *length = blockHeader->sectorSize;
        return AARUF_STATUS_OK;
    }

    // Decompress block
    switch(blockHeader->compression)
    {
        case None:
            block = (uint8_t *)malloc(blockHeader->length);
            if(block == NULL) return AARUF_ERROR_NOT_ENOUGH_MEMORY;

            readBytes = fread(block, 1, blockHeader->length, ctx->imageStream);

            if(readBytes != blockHeader->length)
            {
                free(block);
                return AARUF_ERROR_CANNOT_READ_BLOCK;
            }

            break;
        case Lzma:
            lzmaSize = blockHeader->cmpLength - LZMA_PROPERTIES_LENGTH;
            cmpData  = malloc(lzmaSize);

            if(cmpData == NULL)
            {
                fprintf(stderr, "Cannot allocate memory for block...\n");
                return AARUF_ERROR_NOT_ENOUGH_MEMORY;
            }

            block = malloc(blockHeader->length);
            if(block == NULL)
            {
                fprintf(stderr, "Cannot allocate memory for block...\n");
                free(cmpData);
                return AARUF_ERROR_NOT_ENOUGH_MEMORY;
            }

            readBytes = fread(lzmaProperties, 1, LZMA_PROPERTIES_LENGTH, ctx->imageStream);

            if(readBytes != LZMA_PROPERTIES_LENGTH)
            {
                fprintf(stderr, "Could not read LZMA properties...\n");
                free(block);
                free(cmpData);
                return AARUF_ERROR_CANNOT_DECOMPRESS_BLOCK;
            }

            readBytes = fread(cmpData, 1, lzmaSize, ctx->imageStream);
            if(readBytes != lzmaSize)
            {
                fprintf(stderr, "Could not read compressed block...\n");
                free(cmpData);
                free(block);
                break;
            }

            readBytes = blockHeader->length;
            errorNo =
                aaruf_lzma_decode_buffer(block, &readBytes, cmpData, &lzmaSize, lzmaProperties, LZMA_PROPERTIES_LENGTH);

            if(errorNo != 0)
            {
                fprintf(stderr, "Got error %d from LZMA...\n", errorNo);
                free(cmpData);
                free(block);
                return AARUF_ERROR_CANNOT_DECOMPRESS_BLOCK;
            }

            if(readBytes != blockHeader->length)
            {
                fprintf(stderr, "Error decompressing block, should be {0} bytes but got {1} bytes...\n");
                free(cmpData);
                free(block);
                return AARUF_ERROR_CANNOT_DECOMPRESS_BLOCK;
            }

            free(cmpData);

            break;
        case Flac:
            cmpData = malloc(blockHeader->cmpLength);

            if(cmpData == NULL)
            {
                fprintf(stderr, "Cannot allocate memory for block...\n");
                return AARUF_ERROR_NOT_ENOUGH_MEMORY;
            }

            block = malloc(blockHeader->length);
            if(block == NULL)
            {
                fprintf(stderr, "Cannot allocate memory for block...\n");
                free(cmpData);
                return AARUF_ERROR_NOT_ENOUGH_MEMORY;
            }

            readBytes = fread(cmpData, 1, blockHeader->cmpLength, ctx->imageStream);
            if(readBytes != blockHeader->cmpLength)
            {
                fprintf(stderr, "Could not read compressed block...\n");
                free(cmpData);
                free(block);
                break;
            }

            readBytes = aaruf_flac_decode_redbook_buffer(block, blockHeader->length, cmpData, blockHeader->cmpLength);

            if(readBytes != blockHeader->length)
            {
                fprintf(stderr, "Error decompressing block, should be {0} bytes but got {1} bytes...\n");
                free(cmpData);
                free(block);
                return AARUF_ERROR_CANNOT_DECOMPRESS_BLOCK;
            }

            free(cmpData);

            break;
        default:
            return AARUF_ERROR_UNSUPPORTED_COMPRESSION;
    }

    // Add block to cache
    add_to_cache_uint64(&ctx->blockCache, blockOffset, block);

    memcpy(data, block + (offset * blockHeader->sectorSize), blockHeader->sectorSize);
    *length = blockHeader->sectorSize;
    return AARUF_STATUS_OK;
}

int32_t aaruf_read_track_sector(void *context, uint8_t *data, uint64_t sectorAddress, uint32_t *length, uint8_t track)
{
    aaruformatContext *ctx;
    int                i;

    if(context == NULL) return AARUF_ERROR_NOT_AARUFORMAT;

    ctx = context;

    // Not a libaaruformat context
    if(ctx->magic != AARU_MAGIC) return AARUF_ERROR_NOT_AARUFORMAT;

    if(ctx->imageInfo.XmlMediaType != OpticalDisc) return AARUF_ERROR_INCORRECT_MEDIA_TYPE;

    for(i = 0; i < ctx->numberOfDataTracks; i++)
    {
        if(ctx->dataTracks[i].sequence == track)
        {
            return aaruf_read_sector(context, ctx->dataTracks[i].start + sectorAddress, data, length);
        }
    }

    return AARUF_ERROR_TRACK_NOT_FOUND;
}

int32_t aaruf_read_sector_long(void *context, uint64_t sectorAddress, uint8_t *data, uint32_t *length)
{
    aaruformatContext *ctx = NULL;
    uint32_t bareLength = 0;
    uint32_t tagLength = 0;
    uint8_t *bareData = NULL;
    int32_t res = 0;
    TrackEntry         trk;
    int i = 0;
    bool trkFound = false;

    if(context == NULL) return AARUF_ERROR_NOT_AARUFORMAT;

    ctx = context;

    // Not a libaaruformat context
    if(ctx->magic != AARU_MAGIC) return AARUF_ERROR_NOT_AARUFORMAT;

    switch(ctx->imageInfo.XmlMediaType)
    {
        case OpticalDisc:
            if(*length < 2352 || data == NULL)
            {
                *length = 2352;
                return AARUF_ERROR_BUFFER_TOO_SMALL;
            }
            if((ctx->sectorSuffix == NULL || ctx->sectorPrefix == NULL) &&
               (ctx->sectorSuffixCorrected == NULL || ctx->sectorPrefixCorrected == NULL))
                return aaruf_read_sector(context, sectorAddress, data, length);

            bareLength = 0;
            aaruf_read_sector(context, sectorAddress, NULL, &bareLength);

            bareData = (uint8_t *)malloc(bareLength);

            if(bareData == NULL) return AARUF_ERROR_NOT_ENOUGH_MEMORY;

            res = aaruf_read_sector(context, sectorAddress, bareData, &bareLength);

            if(res < AARUF_STATUS_OK)
            {
                free(bareData);
                return res;
            }

            trkFound = false;

            for(i = 0; i < ctx->numberOfDataTracks; i++)
            {
                if(sectorAddress >= ctx->dataTracks[i].start && sectorAddress <= ctx->dataTracks[i].end)
                {
                    trkFound = true;
                    trk      = ctx->dataTracks[i];
                    break;
                }
            }

            if(!trkFound) return AARUF_ERROR_TRACK_NOT_FOUND;

            switch(trk.type)
            {
                case Audio:
                case Data:
                    memcpy(data, bareData, bareLength);
                    return res;
                case CdMode1:
                    memcpy(data + 16, bareData, 2048);

                    if(ctx->sectorPrefix != NULL)
                        memcpy(data, ctx->sectorPrefix + (sectorAddress * 16), 16);
                    else if(ctx->sectorPrefixDdt != NULL)
                    {
                        if((ctx->sectorPrefixDdt[sectorAddress] & CD_XFIX_MASK) == Correct)
                        {
                            aaruf_ecc_cd_reconstruct_prefix(data, trk.type, sectorAddress);
                            res = AARUF_STATUS_OK;
                        }
                        else if((ctx->sectorPrefixDdt[sectorAddress] & CD_XFIX_MASK) == NotDumped)
                        {
                            res = AARUF_STATUS_SECTOR_NOT_DUMPED;
                        }
                        else
                        {
                            memcpy(data,
                                   ctx->sectorPrefixCorrected +
                                       ((ctx->sectorPrefixDdt[sectorAddress] & CD_DFIX_MASK) - 1) * 16,
                                   16);
                        }
                    }
                    else
                        return AARUF_ERROR_REACHED_UNREACHABLE_CODE;

                    if(res != AARUF_STATUS_OK) return res;

                    if(ctx->sectorSuffix != NULL)
                        memcpy(data + 2064, ctx->sectorSuffix + sectorAddress * 288, 288);
                    else if(ctx->sectorSuffixDdt != NULL)
                    {
                        if((ctx->sectorSuffixDdt[sectorAddress] & CD_XFIX_MASK) == Correct)
                        {
                            aaruf_ecc_cd_reconstruct(ctx->eccCdContext, data, trk.type);
                            res = AARUF_STATUS_OK;
                        }
                        else if((ctx->sectorSuffixDdt[sectorAddress] & CD_XFIX_MASK) == NotDumped)
                        {
                            res = AARUF_STATUS_SECTOR_NOT_DUMPED;
                        }
                        else
                        {
                            memcpy(data + 2064,
                                   ctx->sectorSuffixCorrected +
                                       ((ctx->sectorSuffixDdt[sectorAddress] & CD_DFIX_MASK) - 1) * 288,
                                   288);
                        }
                    }
                    else
                        return AARUF_ERROR_REACHED_UNREACHABLE_CODE;

                    return res;
                case CdMode2Formless:
                case CdMode2Form1:
                case CdMode2Form2:
                    if(ctx->sectorPrefix != NULL)
                        memcpy(data, ctx->sectorPrefix + sectorAddress * 16, 16);
                    else if(ctx->sectorPrefixDdt != NULL)
                    {
                        if((ctx->sectorPrefixDdt[sectorAddress] & CD_XFIX_MASK) == Correct)
                        {
                            aaruf_ecc_cd_reconstruct_prefix(data, trk.type, sectorAddress);
                            res = AARUF_STATUS_OK;
                        }
                        else if((ctx->sectorPrefixDdt[sectorAddress] & CD_XFIX_MASK) == NotDumped)
                        {
                            res = AARUF_STATUS_SECTOR_NOT_DUMPED;
                        }
                        else
                        {
                            memcpy(data,
                                   ctx->sectorPrefixCorrected +
                                       ((ctx->sectorPrefixDdt[sectorAddress] & CD_DFIX_MASK) - 1) * 16,
                                   16);
                        }
                    }
                    else
                        return AARUF_ERROR_REACHED_UNREACHABLE_CODE;

                    if(res != AARUF_STATUS_OK) return res;

                    if(ctx->mode2Subheaders != NULL && ctx->sectorSuffixDdt != NULL)
                    {
                        memcpy(data + 16, ctx->mode2Subheaders + sectorAddress * 8, 8);

                        if((ctx->sectorSuffixDdt[sectorAddress] & CD_XFIX_MASK) == Mode2Form1Ok)
                        {
                            memcpy(data + 24, bareData, 2048);
                            aaruf_ecc_cd_reconstruct(ctx->eccCdContext, data, CdMode2Form1);
                        }
                        else if((ctx->sectorSuffixDdt[sectorAddress] & CD_XFIX_MASK) == Mode2Form2Ok ||
                                (ctx->sectorSuffixDdt[sectorAddress] & CD_XFIX_MASK) == Mode2Form2NoCrc)
                        {
                            memcpy(data + 24, bareData, 2324);
                            if((ctx->sectorSuffixDdt[sectorAddress] & CD_XFIX_MASK) == Mode2Form2Ok)
                                aaruf_ecc_cd_reconstruct(ctx->eccCdContext, data, CdMode2Form2);
                        }
                        else if((ctx->sectorSuffixDdt[sectorAddress] & CD_XFIX_MASK) == NotDumped)
                        {
                            res = AARUF_STATUS_SECTOR_NOT_DUMPED;
                        }
                        else
                            // Mode 2 where ECC failed
                            memcpy(data + 24, bareData, 2328);
                    }
                    else if(ctx->mode2Subheaders != NULL)
                    {
                        memcpy(data + 16, ctx->mode2Subheaders + sectorAddress * 8, 8);
                        memcpy(data + 24, bareData, 2328);
                    }
                    else
                        memcpy(data + 16, bareData, 2336);

                    return res;
                default:
                    return AARUF_ERROR_INVALID_TRACK_FORMAT;
            }
        case BlockMedia:
            switch(ctx->imageInfo.MediaType)
            {
                case AppleFileWare:
                case AppleProfile:
                case AppleSonySS:
                case AppleSonyDS:
                case AppleWidget:
                case PriamDataTower:
                    if(ctx->sectorSubchannel == NULL) return aaruf_read_sector(context, sectorAddress, data, length);

                    switch(ctx->imageInfo.MediaType)
                    {
                        case AppleFileWare:
                        case AppleProfile:
                        case AppleWidget:
                            tagLength = 20;
                            break;
                        case AppleSonySS:
                        case AppleSonyDS:
                            tagLength = 12;
                            break;
                        case PriamDataTower:
                            tagLength = 24;
                            break;
                        default:
                            return AARUF_ERROR_INCORRECT_MEDIA_TYPE;
                    }

                    bareLength = 512;

                    if(*length < tagLength + bareLength || data == NULL)
                    {
                        *length = tagLength + bareLength;
                        return AARUF_ERROR_BUFFER_TOO_SMALL;
                    }

                    bareData = malloc(bareLength);

                    if(bareData == NULL) return AARUF_ERROR_NOT_ENOUGH_MEMORY;

                    res = aaruf_read_sector(context, sectorAddress, bareData, &bareLength);

                    if(bareLength != 512) return res;

                    memcpy(data, ctx->sectorSubchannel + sectorAddress * tagLength, tagLength);
                    memcpy(data, bareData, 512);

                    free(bareData);

                    return res;
                default:
                    return AARUF_ERROR_INCORRECT_MEDIA_TYPE;
            }
        default:
            return AARUF_ERROR_INCORRECT_MEDIA_TYPE;
    }
}