Add support for processing tape files and update context structures

This commit is contained in:
2025-10-07 11:30:11 +01:00
parent 01152f5c25
commit f62899ed06
5 changed files with 236 additions and 1 deletions

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@@ -136,7 +136,8 @@ add_library(aaruformat SHARED include/aaruformat/consts.h include/aaruformat/enu
include/aaruformat/structs/lisa_tag.h
src/metadata.c
src/dump.c
include/aaruformat/structs/tape.h)
include/aaruformat/structs/tape.h
src/blocks/tape.c)
include_directories(include include/aaruformat 3rdparty/uthash/include 3rdparty/uthash/src)

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@@ -123,6 +123,13 @@ typedef struct mediaTagEntry
UT_hash_handle hh; ///< uthash linkage.
} mediaTagEntry;
typedef struct TapeFileHashEntry
{
uint64_t key; ///< Composite key: partition << 32 | file
TapeFileEntry fileEntry; ///< The actual tape file data
UT_hash_handle hh; ///< UTHASH handle
} tapeFileHashEntry;
/** \struct aaruformatContext
* \brief Master context representing an open or increation Aaru image.
*
@@ -248,6 +255,8 @@ typedef struct aaruformatContext
bool compression_enabled; ///< True if block compression enabled (writing path).
uint32_t lzma_dict_size; ///< LZMA dictionary size (writing path).
tapeFileHashEntry *tapeFiles; ///< Hash table root for tape files
} aaruformatContext;
/** \struct DumpHardwareEntriesWithData

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@@ -37,6 +37,7 @@ void process_cicm_block(aaruformatContext *ctx, const IndexEntry *entry);
void process_aaru_metadata_json_block(aaruformatContext *ctx, const IndexEntry *entry);
void process_dumphw_block(aaruformatContext *ctx, const IndexEntry *entry);
void process_checksum_block(aaruformatContext *ctx, const IndexEntry *entry);
void process_tape_files_block(aaruformatContext *ctx, const IndexEntry *entry);
void add_subindex_entries(aaruformatContext *ctx, UT_array *index_entries, IndexEntry *subindex_entry);
int32_t decode_ddt_entry_v1(aaruformatContext *ctx, uint64_t sector_address, uint64_t *offset, uint64_t *block_offset,
uint8_t *sector_status);

221
src/blocks/tape.c Normal file
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@@ -0,0 +1,221 @@
/*
* 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 "aaruformat.h"
#include "log.h"
/**
* @brief Processes a tape file metadata block from the image stream.
*
* Reads and parses a TapeFileBlock from the Aaru image, validates its integrity,
* and populates the context's tape file hash table with file layout information.
* Each tape file entry defines a logical file on the tape medium by specifying
* its partition, file number, and block range (FirstBlock to LastBlock inclusive).
*
* The function performs the following operations:
* 1. Seeks to the block position indicated by the index entry
* 2. Reads and validates the TapeFileHeader structure
* 3. Allocates and reads the array of TapeFileEntry structures
* 4. Validates data integrity using CRC64-ECMA checksum
* 5. Inserts each file entry into the context's UTHASH table with a composite key
* 6. Updates image size statistics
*
* **Composite Key Construction:**
* Each tape file is uniquely identified by a 64-bit composite key:
* key = (partition << 32) | file_number
* This allows files with the same file number in different partitions to coexist
* in the hash table without conflicts.
*
* **Hash Table Management:**
* The function uses HASH_REPLACE to insert entries, which automatically:
* - Adds new entries if the key doesn't exist
* - Replaces existing entries if the key is found (freeing the old entry)
* This ensures that duplicate entries (same partition/file combination) are
* properly handled by keeping only the most recent definition.
*
* **Error Handling:**
* The function treats most errors as non-fatal and continues processing:
* - Invalid context or stream: Returns immediately (FATAL log)
* - Seek failures: Returns immediately (FATAL log)
* - Header read failures: Returns early (TRACE log)
* - Incorrect block identifier: Logs warning but continues
* - Memory allocation failures: Logs error and returns
* - Entry read failures: Frees buffer and returns
* - CRC64 mismatch: Logs warning, frees buffer, and returns
* - Per-entry allocation failures: Logs error and skips that entry
*
* **Block Structure:**
* The tape file block consists of:
* ```
* +-------------------------+
* | TapeFileHeader (24 B) | <- identifier, entries, length, crc64
* +-------------------------+
* | TapeFileEntry 0 (21 B) | <- File, Partition, FirstBlock, LastBlock
* | TapeFileEntry 1 (21 B) |
* | ... |
* | TapeFileEntry (n-1) |
* +-------------------------+
* ```
*
* **CRC64 Validation:**
* The CRC64 checksum in the header is computed over the entire array of
* TapeFileEntry structures (excluding the header itself). This provides
* integrity verification to detect corruption in the file table.
*
* **Memory Management:**
* - Allocates a temporary buffer to read all file entries
* - Allocates individual hash table entries for each file
* - Frees the temporary buffer before returning
* - Frees replaced hash entries automatically
* - Hash table entries remain in context until cleanup
*
* @param ctx Pointer to the aaruformat context. Must not be NULL.
* The context must have a valid imageStream open for reading.
* The ctx->tapeFiles hash table will be populated with file entries.
* The ctx->imageInfo.ImageSize will be updated with the block size.
*
* @param entry Pointer to the index entry describing the tape file block.
* Must not be NULL. The entry->offset field indicates the file
* position where the TapeFileHeader begins.
*
* @note This function does not return a status code. All errors are handled
* internally with appropriate logging and the function returns early
* on fatal errors.
*
* @note The tape file hash table (ctx->tapeFiles) must be initialized to NULL
* before the first call to this function. UTHASH will manage the table
* automatically as entries are added.
*
* @note Files are ordered in the hash table by their composite key value, not
* by insertion order. To iterate files in partition/file number order,
* use HASH_SORT with an appropriate comparison function.
*
* @note The function updates ctx->imageInfo.ImageSize by adding the size of
* all file entries (entries × sizeof(TapeFileEntry)). This contributes
* to the total reported image size but does not include the header size.
*
* @warning The context and imageStream must be valid. Passing NULL pointers
* will result in immediate return with a FATAL log message.
*
* @warning If the CRC64 checksum validation fails, all entries in the block
* are discarded. The function does not attempt partial recovery.
*
* @warning If memory allocation fails for a hash entry, that specific file
* entry is skipped but processing continues with remaining entries.
*
* @see TapeFileHeader for the block header structure
* @see TapeFileEntry for individual file entry structure
* @see tapeFileHashEntry for the hash table entry structure
* @see process_tape_partition_block() for partition metadata processing
*/
void process_tape_files_block(aaruformatContext *ctx, const IndexEntry *entry)
{
long pos = 0;
size_t read_bytes = 0;
TapeFileHeader tape_file_header = {0};
// Check if the context and image stream are valid
if(ctx == NULL || ctx->imageStream == NULL)
{
FATAL("Invalid context or image stream.");
return;
}
// Seek to block
pos = fseek(ctx->imageStream, entry->offset, SEEK_SET);
if(pos < 0 || ftell(ctx->imageStream) != entry->offset)
{
FATAL("Could not seek to %" PRIu64 " as indicated by index entry...\n", entry->offset);
return;
}
// Even if those two checks shall have been done before
read_bytes = fread(&tape_file_header, 1, sizeof(TapeFileHeader), ctx->imageStream);
if(read_bytes != sizeof(TapeFileHeader))
{
TRACE("Could not read tape files header, continuing...\n");
return;
}
if(tape_file_header.identifier != TapeFileBlock)
TRACE("Incorrect identifier for data block at position %" PRIu64 "\n", entry->offset);
ctx->imageInfo.ImageSize += sizeof(TapeFileEntry) * tape_file_header.entries;
uint8_t *buffer = malloc(sizeof(TapeFileEntry) * tape_file_header.entries);
if(buffer == NULL)
{
FATAL("Could not allocate memory for tape files block, continuing...\n");
return;
}
read_bytes = fread(buffer, sizeof(TapeFileEntry), tape_file_header.entries, ctx->imageStream);
if(read_bytes != tape_file_header.entries)
{
free(buffer);
FATAL("Could not read tape files block, continuing...\n");
return;
}
// Check CRC64
uint64_t crc64 = aaruf_crc64_data(buffer, sizeof(TapeFileEntry) * tape_file_header.entries);
if(crc64 != tape_file_header.crc64)
{
TRACE("Incorrect CRC found: 0x%" PRIx64 " found, expected 0x%" PRIx64 ", continuing...\n", crc64,
tape_file_header.crc64);
free(buffer);
return;
}
// Insert entries into UTHASH array indexed by partition << 32 | file number
const TapeFileEntry *entries = (TapeFileEntry *)buffer;
for(uint32_t i = 0; i < tape_file_header.entries; i++)
{
// Create hash table entry
tapeFileHashEntry *hash_entry = malloc(sizeof(tapeFileHashEntry));
if(hash_entry == NULL)
{
FATAL("Could not allocate memory for tape file hash entry\n");
continue;
}
// Create composite key: partition << 32 | file number
hash_entry->key = (uint64_t)entries[i].Partition << 32 | entries[i].File;
// Copy the tape file entry data
hash_entry->fileEntry = entries[i];
// Replace if exists, add if new
tapeFileHashEntry *old_entry = NULL;
HASH_REPLACE(hh, ctx->tapeFiles, key, sizeof(uint64_t), hash_entry, old_entry);
// Free old entry if it was replaced
if(old_entry != NULL)
{
TRACE("Replaced existing tape file entry for partition %u, file %u\n", entries[i].Partition,
entries[i].File);
free(old_entry);
}
else
TRACE("Added new tape file entry for partition %u, file %u\n", entries[i].Partition, entries[i].File);
}
free(buffer);
}

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@@ -385,6 +385,9 @@ void *aaruf_open(const char *filepath)
process_checksum_block(ctx, entry);
break;
case TapeFileBlock:
process_tape_files_block(ctx, entry);
default:
TRACE("Unhandled block type %4.4s with data type %d is indexed to be at %" PRIu64 "",
(char *)&entry->blockType, entry->dataType, entry->offset);