ntfs-3g,Linux加载ntfs驱动

/** * attrib.c - Attribute handling code. Originated from the Linux-NTFS project. * * Copyright (c) 2000-2010 Anton Altaparmakov * Copyright (c) 2002-2005 Richard Russon * Copyright (c) 2002-2008 Szabolcs Szakacsits * Copyright (c) 2004-2007 Yura Pakhuchiy * Copyright (c) 2007-2021 Jean-Pierre Andre * Copyright (c) 2010 Erik Larsson * * This program/include file 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 2 of the License, or * (at your option) any later version. * * This program/include file 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 (in the main directory of the NTFS-3G * distribution in the file COPYING); if not, write to the Free Software * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #ifdef HAVE_STDIO_H #include <stdio.h> #endif #ifdef HAVE_STRING_H #include <string.h> #endif #ifdef HAVE_STDLIB_H #include <stdlib.h> #endif #ifdef HAVE_ERRNO_H #include <errno.h> #endif #ifdef HAVE_LIMITS_H #include <limits.h> #endif #include "param.h" #include "compat.h" #include "attrib.h" #include "attrlist.h" #include "device.h" #include "mft.h" #include "debug.h" #include "mst.h" #include "volume.h" #include "types.h" #include "layout.h" #include "inode.h" #include "runlist.h" #include "lcnalloc.h" #include "dir.h" #include "compress.h" #include "bitmap.h" #include "logging.h" #include "misc.h" #include "efs.h" ntfschar AT_UNNAMED[] = { const_cpu_to_le16('\0') }; ntfschar STREAM_SDS[] = { const_cpu_to_le16('$'), const_cpu_to_le16('S'), const_cpu_to_le16('D'), const_cpu_to_le16('S'), const_cpu_to_le16('\0') }; ntfschar TXF_DATA[] = { const_cpu_to_le16('$'), const_cpu_to_le16('T'), const_cpu_to_le16('X'), const_cpu_to_le16('F'), const_cpu_to_le16('_'), const_cpu_to_le16('D'), const_cpu_to_le16('A'), const_cpu_to_le16('T'), const_cpu_to_le16('A'), const_cpu_to_le16('\0') }; static int NAttrFlag(ntfs_attr *na, FILE_ATTR_FLAGS flag) { if (na->type == AT_DATA && na->name == AT_UNNAMED) return (na->ni->flags & flag); return 0; } static void NAttrSetFlag(ntfs_attr *na, FILE_ATTR_FLAGS flag) { if (na->type == AT_DATA && na->name == AT_UNNAMED) na->ni->flags |= flag; else ntfs_log_trace("Denied setting flag %d for not unnamed data " "attribute\n", le32_to_cpu(flag)); } static void NAttrClearFlag(ntfs_attr *na, FILE_ATTR_FLAGS flag) { if (na->type == AT_DATA && na->name == AT_UNNAMED) na->ni->flags &= ~flag; } #define GenNAttrIno(func_name, flag) \ int NAttr##func_name(ntfs_attr *na) { return NAttrFlag (na, flag); } \ void NAttrSet##func_name(ntfs_attr *na) { NAttrSetFlag (na, flag); } \ void NAttrClear##func_name(ntfs_attr *na){ NAttrClearFlag(na, flag); } GenNAttrIno(Compressed, FILE_ATTR_COMPRESSED) GenNAttrIno(Encrypted, FILE_ATTR_ENCRYPTED) GenNAttrIno(Sparse, FILE_ATTR_SPARSE_FILE) /** * ntfs_get_attribute_value_length - Find the length of an attribute * @a: * * Description... * * Returns: */ s64 ntfs_get_attribute_value_length(const ATTR_RECORD *a) { if (!a) { errno = EINVAL; return 0; } errno = 0; if (a->non_resident) return sle64_to_cpu(a->data_size); return (s64)le32_to_cpu(a->value_length); } /** * ntfs_get_attribute_value - Get a copy of an attribute * @vol: * @a: * @b: * * Description... * * Returns: */ s64 ntfs_get_attribute_value(const ntfs_volume *vol, const ATTR_RECORD *a, u8 *b) { runlist *rl; s64 total, r; int i; /* Sanity checks. */ if (!vol || !a || !b) { errno = EINVAL; return 0; } /* Complex attribute? */ /* * Ignore the flags in case they are not zero for an attribute list * attribute. Windows does not complain about invalid flags and chkdsk * does not detect or fix them so we need to cope with it, too. */ if (a->type != AT_ATTRIBUTE_LIST && a->flags) { ntfs_log_error("Non-zero (%04x) attribute flags. Cannot handle " "this yet.\n", le16_to_cpu(a->flags)); errno = EOPNOTSUPP; return 0; } if (!a->non_resident) { /* Attribute is resident. */ /* Sanity check. */ if (le32_to_cpu(a->value_length) + le16_to_cpu(a->value_offset) > le32_to_cpu(a->length)) { return 0; } memcpy(b, (const char*)a + le16_to_cpu(a->value_offset), le32_to_cpu(a->value_length)); errno = 0; return (s64)le32_to_cpu(a->value_length); } /* Attribute is not resident. */ /* If no data, return 0. */ if (!(a->data_size)) { errno = 0; return 0; } /* * FIXME: What about attribute lists?!? (AIA) */ /* Decompress the mapping pairs array into a runlist. */ rl = ntfs_mapping_pairs_decompress(vol, a, NULL); if (!rl) { errno = EINVAL; return 0; } /* * FIXED: We were overflowing here in a nasty fashion when we * reach the last cluster in the runlist as the buffer will * only be big enough to hold data_size bytes while we are * reading in allocated_size bytes which is usually larger * than data_size, since the actual data is unlikely to have a * size equal to a multiple of the cluster size! * FIXED2: We were also overflowing here in the same fashion * when the data_size was more than one run smaller than the * allocated size which happens with Windows XP sometimes. */ /* Now load all clusters in the runlist into b. */ for (i = 0, total = 0; rl[i].length; i++) { if (total + (rl[i].length << vol->cluster_size_bits) >= sle64_to_cpu(a->data_size)) { unsigned char *intbuf = NULL; s64 intlth; /* * We have reached the last run so we were going to * overflow when executing the ntfs_pread() which is * BAAAAAAAD! * Temporary fix: * Allocate a new buffer with size: * rl[i].length << vol->cluster_size_bits, do the * read into our buffer, then memcpy the correct * amount of data into the caller supplied buffer, * free our buffer, and continue. * We have reached the end of data size so we were * going to overflow in the same fashion. * Temporary fix: same as above. * * For safety, limit the amount to read to the * needed size, knowing that the whole attribute * size has been checked to be <= 0x40000. */ intlth = (sle64_to_cpu(a->data_size) - total + vol->cluster_size - 1) >> vol->cluster_size_bits; if (rl[i].length < intlth) intlth = rl[i].length; intbuf = (u8*)ntfs_malloc(intlth << vol->cluster_size_bits); if (!intbuf) { free(rl); return 0; } /* * FIXME: If compressed file: Only read if lcn != -1. * Otherwise, we are dealing with a sparse run and we * just memset the user buffer to 0 for the length of * the run, which should be 16 (= compression unit * size). * FIXME: Really only when file is compressed, or can * we have sparse runs in uncompressed files as well? * - Yes we can, in sparse files! But not necessarily * size of 16, just run length. */ r = ntfs_pread(vol->dev, rl[i].lcn << vol->cluster_size_bits, intlth << vol->cluster_size_bits, intbuf); if (r != intlth << vol->cluster_size_bits) { #define ESTR "Error reading attribute value" if (r == -1) ntfs_log_perror(ESTR); else if (r < intlth << vol->cluster_size_bits) { ntfs_log_debug(ESTR ": Ran out of input data.\n"); errno = EIO; } else { ntfs_log_debug(ESTR ": unknown error\n"); errno = EIO; } #undef ESTR free(rl); free(intbuf); return 0; } memcpy(b + total, intbuf, sle64_to_cpu(a->data_size) - total); free(intbuf); total = sle64_to_cpu(a->data_size);