diff options
Diffstat (limited to '')
| -rw-r--r-- | libparted/fs/r/fat/traverse.c | 368 |
1 files changed, 368 insertions, 0 deletions
diff --git a/libparted/fs/r/fat/traverse.c b/libparted/fs/r/fat/traverse.c new file mode 100644 index 0000000..42eeff9 --- /dev/null +++ b/libparted/fs/r/fat/traverse.c @@ -0,0 +1,368 @@ +/* + libparted + Copyright (C) 1998-2000, 2005, 2007-2014, 2019-2023 Free Software + Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include <config.h> +#include "fat.h" +#include "traverse.h" + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#ifndef DISCOVER_ONLY + +#define NO_CLUSTER -1 + +static char tmp_buffer [4096]; + +int _GL_ATTRIBUTE_PURE +fat_traverse_entries_per_buffer (FatTraverseInfo* trav_info) +{ + return trav_info->buffer_size / sizeof (FatDirEntry); +} + +/* returns 1 if there are no more directory entries in the directory being + * traversed, 0 otherwise. + */ +static int +is_last_buffer (FatTraverseInfo* trav_info) { + FatSpecific* fs_info = FAT_SPECIFIC (trav_info->fs); + + if (trav_info->is_legacy_root_dir) + return 1; + else + return fat_table_is_eof (fs_info->fat, trav_info->next_buffer); +} + +static int +write_root_dir (FatTraverseInfo* trav_info) +{ + FatSpecific* fs_info = FAT_SPECIFIC (trav_info->fs); + + if (!ped_geometry_write (trav_info->fs->geom, trav_info->dir_entries, + fs_info->root_dir_offset, + fs_info->root_dir_sector_count)) + return 0; + if (!ped_geometry_sync (trav_info->fs->geom)) + return 0; + trav_info->dirty = 0; + return 1; +} + +static int +write_dir_cluster (FatTraverseInfo* trav_info) +{ + if (!fat_write_sync_cluster (trav_info->fs, + (void*) trav_info->dir_entries, + trav_info->this_buffer)) + return 0; + trav_info->dirty = 0; + return 1; +} + +static int +write_dir_buffer (FatTraverseInfo* trav_info) +{ + if (trav_info->is_legacy_root_dir) + return write_root_dir (trav_info); + else + return write_dir_cluster (trav_info); +} + +static int +read_next_dir_buffer (FatTraverseInfo* trav_info) +{ + FatSpecific* fs_info = FAT_SPECIFIC (trav_info->fs); + + PED_ASSERT (!trav_info->is_legacy_root_dir); + + trav_info->this_buffer = trav_info->next_buffer; + + if (trav_info->this_buffer < 2 + || trav_info->this_buffer >= fs_info->cluster_count + 2) { + ped_exception_throw ( + PED_EXCEPTION_ERROR, + PED_EXCEPTION_CANCEL, + "Cluster %ld in directory %s is outside file system!", + (long) trav_info->this_buffer, + trav_info->dir_name); + return 0; + } + + trav_info->next_buffer + = fat_table_get (fs_info->fat, trav_info->this_buffer); + + return fat_read_cluster (trav_info->fs, (void *) trav_info->dir_entries, + trav_info->this_buffer); +} + +/* FIXME: put into fat_dir_entry_* operations */ +void +fat_traverse_mark_dirty (FatTraverseInfo* trav_info) +{ + trav_info->dirty = 1; +} + +FatTraverseInfo* +fat_traverse_begin (PedFileSystem* fs, FatCluster start_cluster, + const char* dir_name) +{ + FatSpecific* fs_info = FAT_SPECIFIC (fs); + FatTraverseInfo* trav_info; + + trav_info = (FatTraverseInfo*) ped_malloc (sizeof (FatTraverseInfo)); + if (!trav_info) + goto error; + + trav_info->dir_name = strdup (dir_name); + if (!trav_info->dir_name) + goto error_free_trav_info; + + trav_info->fs = fs; + trav_info->is_legacy_root_dir + = (fs_info->fat_type == FAT_TYPE_FAT16) && (start_cluster == 0); + trav_info->dirty = 0; + trav_info->eof = 0; + trav_info->current_entry = -1; + + if (trav_info->is_legacy_root_dir) { + trav_info->buffer_size = 512 * fs_info->root_dir_sector_count; + } else { + trav_info->next_buffer = start_cluster; + trav_info->buffer_size = fs_info->cluster_size; + } + + trav_info->dir_entries + = (FatDirEntry*) ped_malloc (trav_info->buffer_size); + if (!trav_info->dir_entries) + goto error_free_dir_name; + + if (trav_info->is_legacy_root_dir) { + if (!ped_geometry_read (fs->geom, trav_info->dir_entries, + fs_info->root_dir_offset, + fs_info->root_dir_sector_count)) + goto error_free_dir_entries; + } else { + if (!read_next_dir_buffer (trav_info)) + goto error_free_dir_entries; + } + + return trav_info; + +error_free_dir_entries: + free (trav_info->dir_entries); +error_free_dir_name: + free (trav_info->dir_name); +error_free_trav_info: + free (trav_info); +error: + return NULL; +} + +int +fat_traverse_complete (FatTraverseInfo* trav_info) +{ + if (trav_info->dirty) { + if (!write_dir_buffer (trav_info)) + return 0; + } + free (trav_info->dir_entries); + free (trav_info->dir_name); + free (trav_info); + return 1; +} + +FatTraverseInfo* +fat_traverse_directory (FatTraverseInfo *trav_info, FatDirEntry* parent) +{ + strcpy (tmp_buffer, trav_info->dir_name); + fat_dir_entry_get_name (parent, + tmp_buffer + strlen (trav_info->dir_name)); + strcat (tmp_buffer, "\\"); + + return fat_traverse_begin (trav_info->fs, + fat_dir_entry_get_first_cluster (parent, trav_info->fs), + tmp_buffer); +} + +FatDirEntry* +fat_traverse_next_dir_entry (FatTraverseInfo *trav_info) +{ + if (trav_info->eof) + return NULL; + + trav_info->current_entry++; + if (trav_info->current_entry + >= fat_traverse_entries_per_buffer (trav_info)) { + if (trav_info->dirty) { + if (!write_dir_buffer (trav_info)) + return NULL; + } + + trav_info->current_entry = 0; + if (is_last_buffer (trav_info)) { + trav_info->eof = 1; + return NULL; + } + if (!read_next_dir_buffer (trav_info)) + return NULL; + } + return trav_info->dir_entries + trav_info->current_entry; +} + +FatCluster _GL_ATTRIBUTE_PURE +fat_dir_entry_get_first_cluster (FatDirEntry* dir_entry, PedFileSystem *fs) +{ + FatSpecific* fs_info = FAT_SPECIFIC (fs); + + switch (fs_info->fat_type) { + case FAT_TYPE_FAT12: + case FAT_TYPE_FAT16: + return PED_LE16_TO_CPU (dir_entry->first_cluster); + + case FAT_TYPE_FAT32: + return PED_LE16_TO_CPU (dir_entry->first_cluster_high) + * 65536L + + PED_LE16_TO_CPU (dir_entry->first_cluster); + } + + return 0; +} + +void +fat_dir_entry_set_first_cluster (FatDirEntry* dir_entry, PedFileSystem* fs, + FatCluster cluster) +{ + FatSpecific* fs_info = FAT_SPECIFIC (fs); + + switch (fs_info->fat_type) { + case FAT_TYPE_FAT12: + PED_ASSERT (0); + break; + + case FAT_TYPE_FAT16: + dir_entry->first_cluster = PED_CPU_TO_LE16 (cluster); + break; + + case FAT_TYPE_FAT32: + dir_entry->first_cluster + = PED_CPU_TO_LE16 (cluster & 0xffff); + dir_entry->first_cluster_high + = PED_CPU_TO_LE16 (cluster / 0x10000); + break; + } +} + +uint32_t _GL_ATTRIBUTE_PURE +fat_dir_entry_get_length (FatDirEntry* dir_entry) +{ + return PED_LE32_TO_CPU (dir_entry->length); +} + +int +fat_dir_entry_is_null_term (const FatDirEntry* dir_entry) +{ + FatDirEntry null_entry; + + memset (&null_entry, 0, sizeof (null_entry)); + return memcmp (&null_entry, dir_entry, sizeof (null_entry)) == 0; +} + +int _GL_ATTRIBUTE_PURE +fat_dir_entry_is_active (FatDirEntry* dir_entry) +{ + if ((unsigned char) dir_entry->name[0] == DELETED_FLAG) return 0; + if ((unsigned char) dir_entry->name[0] == 0) return 0; + if ((unsigned char) dir_entry->name[0] == 0xF6) return 0; + return 1; +} + +int _GL_ATTRIBUTE_PURE +fat_dir_entry_is_file (FatDirEntry* dir_entry) { + if (dir_entry->attributes == VFAT_ATTR) return 0; + if (dir_entry->attributes & VOLUME_LABEL_ATTR) return 0; + if (!fat_dir_entry_is_active (dir_entry)) return 0; + if ((dir_entry->attributes & DIRECTORY_ATTR) == DIRECTORY_ATTR) return 0; + return 1; +} + +int _GL_ATTRIBUTE_PURE +fat_dir_entry_is_system_file (FatDirEntry* dir_entry) +{ + if (!fat_dir_entry_is_file (dir_entry)) return 0; + return (dir_entry->attributes & SYSTEM_ATTR) + || (dir_entry->attributes & HIDDEN_ATTR); +} + +int _GL_ATTRIBUTE_PURE +fat_dir_entry_is_directory (FatDirEntry* dir_entry) +{ + if (dir_entry->attributes == VFAT_ATTR) return 0; + if (dir_entry->attributes & VOLUME_LABEL_ATTR) return 0; + if (!fat_dir_entry_is_active (dir_entry)) return 0; + return (dir_entry->attributes & DIRECTORY_ATTR) == DIRECTORY_ATTR; +} + +int +fat_dir_entry_has_first_cluster (FatDirEntry* dir_entry, PedFileSystem* fs) +{ + FatSpecific* fs_info = FAT_SPECIFIC (fs); + FatCluster first_cluster; + + if (!fat_dir_entry_is_file (dir_entry) + && !fat_dir_entry_is_directory (dir_entry)) + return 0; + + first_cluster = fat_dir_entry_get_first_cluster (dir_entry, fs); + if (first_cluster == 0 + || fat_table_is_eof (fs_info->fat, first_cluster)) + return 0; + + return 1; +} + +/* + decrypts silly DOS names to FILENAME.EXT +*/ +void +fat_dir_entry_get_name (const FatDirEntry *dir_entry, char *result) { + size_t i; + const char *src; + const char *ext; + + src = dir_entry->name; + + for (i=0; i < sizeof dir_entry->name; i++) { + if (src[i] == ' ' || src[i] == 0) break; + *result++ = src[i]; + } + + ext = (const char *) dir_entry->extension; + if (ext[0] != ' ' && ext[0] != 0) { + *result++ = '.'; + for (i=0; i < sizeof dir_entry->extension; i++) { + if (ext[i] == ' ' || ext[i] == 0) break; + *result++ = ext[i]; + } + } + + *result = 0; +} + +#endif /* !DISCOVER_ONLY */ |