/*

 * muscle-filesystem.c: Support for MuscleCard Applet from musclecard.com

 *

 * Copyright (C) 2006, Identity Alliance, Thomas Harning <support@identityalliance.com>

 *

 * 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, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include <memory.h>

#include <stdio.h>

#include <assert.h>

#include "libopensc/muscle-filesystem.h"

#include "libopensc/errors.h"

#define MSCFS_NO_MEMORY   SC_ERROR_OUT_OF_MEMORY

#define MSCFS_INVALID_ARGS  SC_ERROR_INVALID_ARGUMENTS

#define MSCFS_FILE_NOT_FOUND  SC_ERROR_FILE_NOT_FOUND

#define MSCFS_CACHE_INCREMENT 128

static msc_id rootId = { { 0x3F, 0x00, 0x3F, 0x00 } };

static const u8* ignoredFiles[] = {

  (const u8*)"l0\0\0",

  (const u8*)"L0\0\0",

  NULL

};

mscfs_t *mscfs_new(void) {

  mscfs_t *fs = malloc(sizeof(mscfs_t));

  if (!fs)

    return NULL;

  memset(fs, 0, sizeof(mscfs_t));

  memcpy(fs->currentPath, "\x3F\x00", 2);

  return fs;

}

void mscfs_free(mscfs_t *fs) {

  mscfs_clear_cache(fs);

  free(fs);

}

void mscfs_clear_cache(mscfs_t* fs) {

  if(!fs->cache.array) {

    return;

  }

  free(fs->cache.array);

  fs->cache.array = NULL;

  fs->cache.totalSize = 0;

  fs->cache.size = 0;

}

static int mscfs_is_ignored(mscfs_t* fs, msc_id objectId)

{

  int ignored = 0;

  const u8** ptr = ignoredFiles;

  while(ptr && *ptr && !ignored) {

    if(0 == memcmp(objectId.id, *ptr, 4))

      ignored = 1;

    ptr++;

  }

  return ignored;

}

#define MAX_FILES 10000

int mscfs_push_file(mscfs_t* fs, mscfs_file_t *file)

{

  mscfs_cache_t *cache = &fs->cache;

  if (cache->size >= MAX_FILES)

    return SC_ERROR_INTERNAL;

  if(!cache->array || cache->size == cache->totalSize) {

    int length = cache->totalSize + MSCFS_CACHE_INCREMENT;

    mscfs_file_t *oldArray;

    cache->totalSize = length;

    oldArray = cache->array;

    cache->array = malloc(sizeof(mscfs_file_t) * length);

    if(!cache->array)

      return MSCFS_NO_MEMORY;

    if(oldArray) {

      memcpy(cache->array, oldArray, sizeof(mscfs_file_t) * cache->size);

      free(oldArray);

    }

  }

  cache->array[cache->size] = *file;

  cache->size++;

  return SC_SUCCESS;

}

int mscfs_update_cache(mscfs_t* fs) {

  mscfs_file_t file;

  int r;

  mscfs_clear_cache(fs);

  r = fs->listFile(&file, 1, fs->udata);

  if(r == 0)

    return 0;

  else if(r < 0)

    return r;

  while(1) {

    if(!mscfs_is_ignored(fs, file.objectId)) {

      /* Check if its a directory in the root */

      u8* oid = file.objectId.id;

      if(oid[2] == 0 && oid[3] == 0) {

        oid[2] = oid[0];

        oid[3] = oid[1];

        oid[0] = 0x3F;

        oid[1] = 0x00;

        file.ef = 0;

      } else  {

        file.ef = 1; /* File is a working elementary file */

      }

      r = mscfs_push_file(fs, &file);

      if (r != SC_SUCCESS)

        return r;

    }

    r = fs->listFile(&file, 0, fs->udata);

    if(r == 0)

      break;

    else if(r < 0)

      return r;

  }

  return fs->cache.size;

}

int mscfs_check_cache(mscfs_t* fs)

{

  int r = SC_SUCCESS;

  if(!fs->cache.array) {

    r = mscfs_update_cache(fs);

  }

  return r;

}

int mscfs_lookup_path(mscfs_t* fs, const u8 *path, size_t pathlen, msc_id* objectId, int isDirectory)

{

  u8* oid = objectId->id;

  if ((pathlen & 1) != 0) /* not divisible by 2 */

    return MSCFS_INVALID_ARGS;

  if(isDirectory) {

    /* Directory must be right next to root */

    if ((pathlen == 4 && 0 == memcmp(path, "\x3F\x00", 2)) ||

        (pathlen == 2 && 0 == memcmp(fs->currentPath, "\x3F\x00", 2))) {

      oid[0] = path[pathlen - 2];

      oid[1] = path[pathlen - 1];

      oid[2] = oid[3] = 0;

    } else {

      return MSCFS_INVALID_ARGS;

    }

  }

  oid[0] = fs->currentPath[0];

  oid[1] = fs->currentPath[1];

  /* Chop off the root in the path */

  if(pathlen > 2 && memcmp(path, "\x3F\x00", 2) == 0) {

    path += 2;

    pathlen -= 2;

    oid[0] = 0x3F;

    oid[1] = 0x00;

  }

  /* Limit to a single directory */

  if(pathlen > 4)

    return MSCFS_INVALID_ARGS;

  /* Reset to root */

  if(pathlen == 2 && 0 == memcmp(path, "\x3F\x00", 2)) {

    oid[0] = oid[2] = path[0];

    oid[1] = oid[3] = path[1];

  } else if(pathlen == 2) { /* Path preserved for current-path */

    oid[2] = path[0];

    oid[3] = path[1];

  } else if(pathlen == 4) {

    oid[0] = path[0];

    oid[1] = path[1];

    oid[2] = path[2];

    oid[3] = path[3];

  }

  return 0;

}

int mscfs_lookup_local(mscfs_t* fs, const int id, msc_id* objectId)

{

  u8* oid = objectId->id;

  oid[0] = fs->currentPath[0];

  oid[1] = fs->currentPath[1];

  oid[2] = (id >> 8) & 0xFF;

  oid[3] = id & 0xFF;

  return 0;

}

/* -1 any, 0 DF, 1 EF */

int mscfs_check_selection(mscfs_t *fs, int requiredItem)

{

  if(fs->currentPath[0] == 0 && fs->currentPath[1] == 0)

    return MSCFS_INVALID_ARGS;

  if(requiredItem == 1 && fs->currentFile[0] == 0 && fs->currentFile[1] == 0)

    return MSCFS_INVALID_ARGS;

  return 0;

}

int mscfs_loadFileInfo(mscfs_t* fs, const u8 *path, size_t pathlen, mscfs_file_t **file_data, int* idx)

{

  msc_id fullPath = {{0, 0, 0, 0}};

  int x, rc;

  assert(fs != NULL && path != NULL && file_data != NULL);

  rc = mscfs_lookup_path(fs, path, pathlen, &fullPath, 0);

  if (rc != SC_SUCCESS) {

    return rc;

  }

  /* Obtain file information while checking if it exists */

  rc = mscfs_check_cache(fs);

  if (rc < 0)

    return rc;

  if(idx) *idx = -1;

  for(x = 0; x < fs->cache.size; x++) {

    *file_data = &fs->cache.array[x];

    if (*file_data) {

      msc_id objectId;

      objectId = (*file_data)->objectId;

      if(0 == memcmp(objectId.id, fullPath.id, 4)) {

        if (idx)

          *idx = x;

        break;

      }

      *file_data = NULL;

    }

  }

  if(*file_data == NULL && (0 == memcmp("\x3F\x00\x00\x00", fullPath.id, 4) || 0 == memcmp("\x3F\x00\x50\x15", fullPath.id, 4 ) || 0 == memcmp("\x3F\x00\x3F\x00", fullPath.id, 4))) {

    static mscfs_file_t ROOT_FILE;

    ROOT_FILE.ef = 0;

    ROOT_FILE.size = 0;

    /* Faked Root ID */

    ROOT_FILE.objectId = rootId;

    ROOT_FILE.read = 0;

    ROOT_FILE.write = 0x02; /* User Pin access */

    ROOT_FILE.delete = 0x02;

    *file_data = &ROOT_FILE;

    if(idx) *idx = -2;

  } else if(*file_data == NULL) {

    return MSCFS_FILE_NOT_FOUND;

  }

  return 0;

}