/*

** The Sleuth Kit

**

** Copyright (c) 2022 Basis Technology Corp.  All rights reserved

** Contact: Brian Carrier [carrier <at> sleuthkit [dot] org]

**

** This software is distributed under the Common Public License 1.0

**

*/

/**

 * Internal code to open and read logical directories

 */

#include "tsk_img_i.h"

#include "legacy_cache.h"

#include "logical_img.h"

#include "tsk/util/file_system_utils.h"

/**

 * \internal

 * Display information about the disk image set.

 *

 * @param img_info Disk image to analyze

 * @param hFile Handle to print information to

 */

static void

logical_imgstat(TSK_IMG_INFO * img_info, FILE * hFile)

{

  IMG_LOGICAL_INFO *dir_info = (IMG_LOGICAL_INFO *) img_info;

    tsk_fprintf(hFile, "IMAGE FILE INFORMATION\n");

    tsk_fprintf(hFile, "--------------------------------------------\n");

    tsk_fprintf(hFile, "Image Type: logical directory\n");

  tsk_fprintf(hFile,

    "Base Directory Path: %" PRIttocTSK "\n",

    dir_info->base_path);

}

/*

 * Clear a cache entry. Assumes we acquired the cache_lock already or are in the process

 * of closing the image and don't need it.

 */

void

clear_inum_cache_entry(IMG_LOGICAL_INFO *logical_img_info, int index) {

  logical_img_info->inum_cache[index].inum = LOGICAL_INVALID_INUM;

  if (logical_img_info->inum_cache[index].path != NULL) {

    free(logical_img_info->inum_cache[index].path);

    logical_img_info->inum_cache[index].path = NULL;

  }

  logical_img_info->inum_cache[index].cache_age = 0;

}

/**

 * \internal

 *

 *

 * @param img_info logical directory to close

 */

static void

logical_close(TSK_IMG_INFO * img_info)

{

  IMG_LOGICAL_INFO *logical_img_info = (IMG_LOGICAL_INFO *)img_info;

  free(logical_img_info->base_path);

  for (int i = 0; i < LOGICAL_FILE_HANDLE_CACHE_LEN; i++) {

#ifdef TSK_WIN32

    if (logical_img_info->file_handle_cache[i].fd != 0) {

      CloseHandle(logical_img_info->file_handle_cache[i].fd);

    }

#endif

  }

  for (int i = 0; i < LOGICAL_INUM_CACHE_LEN; i++) {

    clear_inum_cache_entry(logical_img_info, i);

  }

  delete logical_img_info->cache;

  tsk_img_free(img_info);

}

static ssize_t

logical_read(

  [[maybe_unused]] TSK_IMG_INFO * img_info,

  [[maybe_unused]] TSK_OFF_T offset,

  [[maybe_unused]] char *buf,

  [[maybe_unused]] size_t len)

{

  tsk_error_reset();

  tsk_error_set_errno(TSK_ERR_IMG_READ);

  tsk_error_set_errstr("logical_read: Logical image read is not supported");

  return 0;

}

/**

 * \internal

 *

 *

 * @param a_num_img Number of images in set

 * @param a_images List of disk image paths (in sorted order)

 * @param a_ssize Size of device sector in bytes (or 0 for default)

 *

 * @return NULL on error

 */

TSK_IMG_INFO *

logical_open(

  int a_num_img,

  const TSK_TCHAR * const a_images[],

  [[maybe_unused]] unsigned int a_ssize)

{

  IMG_LOGICAL_INFO *logical_info;

  TSK_IMG_INFO *img_info;

  if (LOGICAL_IMG_DEBUG_PRINT) fprintf(stderr, "logical_open - Opening image\n");

  fflush(stderr);

#ifndef TSK_WIN32

  tsk_error_reset();

  tsk_error_set_errno(TSK_ERR_IMG_ARG);

  tsk_error_set_errstr("logical_open: Logical directories not supported for non-Windows systems");

  return NULL;

#endif

  if (a_num_img != 1) {

    tsk_error_reset();

    tsk_error_set_errno(TSK_ERR_IMG_ARG);

    tsk_error_set_errstr("logical_open: Only one directory (image name) is supported for logical directories");

    return NULL;

  }

  if ((logical_info =

    (IMG_LOGICAL_INFO *)tsk_img_malloc(sizeof(IMG_LOGICAL_INFO))) == NULL)

    return NULL;

  img_info = (TSK_IMG_INFO *)logical_info;

  logical_info->is_winobj = 0;

#ifdef TSK_WIN32

  logical_info->is_winobj = is_windows_device_path(a_images[0]);

#endif

  // Check that the given path exists and is a directory (return value = -3)

  TSK_OFF_T size_result = get_size_of_file_on_disk(a_images[0], logical_info->is_winobj);

  if (size_result != -3) {

    tsk_error_reset();

    tsk_error_set_errno(TSK_ERR_IMG_ARG);

    tsk_error_set_errstr("logical_open: Image path is not a directory");

    tsk_img_free(img_info);

    return NULL;

  }

  img_info->size = INT64_MAX;

  img_info->itype = TSK_IMG_TYPE_LOGICAL;

  // Initialize file handle cache

  for (int i = 0; i < LOGICAL_FILE_HANDLE_CACHE_LEN; i++) {

    logical_info->file_handle_cache[i].fd = 0;

    logical_info->file_handle_cache[i].inum = LOGICAL_INVALID_INUM;

  }

  logical_info->next_file_handle_cache_slot = 0;

  // Initialize the inum cache

  for (int i = 0; i < LOGICAL_INUM_CACHE_LEN; i++) {

    logical_info->inum_cache[i].inum = LOGICAL_INVALID_INUM;

    logical_info->inum_cache[i].path = NULL;

    logical_info->inum_cache[i].cache_age = 0;

  }

  logical_info->img_info.read = logical_read;

  logical_info->img_info.close = logical_close;

  logical_info->img_info.imgstat = logical_imgstat;

  size_t len = TSTRLEN(a_images[0]);

  logical_info->base_path =

    (TSK_TCHAR *)tsk_malloc(sizeof(TSK_TCHAR) * (len + 1));

  if (logical_info->base_path == NULL) {

    tsk_img_free(img_info);

    return NULL;

  }

  TSTRNCPY(logical_info->base_path, a_images[0], len + 1);

  // Remove trailing slash

#ifdef TSK_WIN32

  if ((logical_info->base_path[TSTRLEN(logical_info->base_path) - 1] == L'/')

      || (logical_info->base_path[TSTRLEN(logical_info->base_path) - 1] == L'\\')) {

    logical_info->base_path[TSTRLEN(logical_info->base_path) - 1] = '\0';

  }

#else

  if (logical_info->base_path[TSTRLEN(logical_info->base_path) - 1] == '/') {

    logical_info->base_path[TSTRLEN(logical_info->base_path) - 1] = '\0';

  }

#endif

  logical_info->cache = new LegacyCache();

  if (LOGICAL_IMG_DEBUG_PRINT) fprintf(stderr, "logical_open - Image opened successfully\n");

  fflush(stderr);

    return img_info;

}