148 files changed, 141286 insertions, 0 deletions
diff --git a/libntfs-3g/runlist.c b/libntfs-3g/runlist.c new file mode 100755 index 0000000..6c99e8e --- a/dev/null +++ b/libntfs-3g/runlist.c @@ -0,0 +1,2166 @@ +/** + * runlist.c - Run list handling code. Originated from the Linux-NTFS project. + * + * Copyright (c) 2002-2005 Anton Altaparmakov + * Copyright (c) 2002-2005 Richard Russon + * Copyright (c) 2002-2008 Szabolcs Szakacsits + * Copyright (c) 2004 Yura Pakhuchiy + * Copyright (c) 2007-2009 Jean-Pierre Andre + * + * 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 + +#include "compat.h" +#include "types.h" +#include "volume.h" +#include "layout.h" +#include "debug.h" +#include "device.h" +#include "logging.h" +#include "misc.h" + +/** + * ntfs_rl_mm - runlist memmove + * @base: + * @dst: + * @src: + * @size: + * + * Description... + * + * Returns: + */ +static void ntfs_rl_mm(runlist_element *base, int dst, int src, int size) +{ + if ((dst != src) && (size > 0)) + memmove(base + dst, base + src, size * sizeof(*base)); +} + +/** + * ntfs_rl_mc - runlist memory copy + * @dstbase: + * @dst: + * @srcbase: + * @src: + * @size: + * + * Description... + * + * Returns: + */ +static void ntfs_rl_mc(runlist_element *dstbase, int dst, + runlist_element *srcbase, int src, int size) +{ + if (size > 0) + memcpy(dstbase + dst, srcbase + src, size * sizeof(*dstbase)); +} + +/** + * ntfs_rl_realloc - Reallocate memory for runlists + * @rl: original runlist + * @old_size: number of runlist elements in the original runlist @rl + * @new_size: number of runlist elements we need space for + * + * As the runlists grow, more memory will be required. To prevent large + * numbers of small reallocations of memory, this function returns a 4kiB block + * of memory. + * + * N.B. If the new allocation doesn't require a different number of 4kiB + * blocks in memory, the function will return the original pointer. + * + * On success, return a pointer to the newly allocated, or recycled, memory. + * On error, return NULL with errno set to the error code. + */ +static runlist_element *ntfs_rl_realloc(runlist_element *rl, int old_size, + int new_size) +{ + old_size = (old_size * sizeof(runlist_element) + 0xfff) & ~0xfff; + new_size = (new_size * sizeof(runlist_element) + 0xfff) & ~0xfff; + if (old_size == new_size) + return rl; + return realloc(rl, new_size); +} + +/* + * Extend a runlist by some entry count + * The runlist may have to be reallocated + * + * Returns the reallocated runlist + * or NULL if reallocation was not possible (with errno set) + */ + +runlist_element *ntfs_rl_extend(runlist_element *rl, int more_entries) +{ + int last; + + last = 0; + while (rl[last].length) + last++; + rl = ntfs_rl_realloc(rl,last+1,last+more_entries+1); + if (!rl) + errno = ENOMEM; + return (rl); +} + +/** + * ntfs_rl_are_mergeable - test if two runlists can be joined together + * @dst: original runlist + * @src: new runlist to test for mergeability with @dst + * + * Test if two runlists can be joined together. For this, their VCNs and LCNs + * must be adjacent. + * + * Return: TRUE Success, the runlists can be merged. + * FALSE Failure, the runlists cannot be merged. + */ +static BOOL ntfs_rl_are_mergeable(runlist_element *dst, runlist_element *src) +{ + if (!dst || !src) { + ntfs_log_debug("Eeek. ntfs_rl_are_mergeable() invoked with NULL " + "pointer!\n"); + return FALSE; + } + + /* We can merge unmapped regions even if they are misaligned. */ + if ((dst->lcn == LCN_RL_NOT_MAPPED) && (src->lcn == LCN_RL_NOT_MAPPED)) + return TRUE; + /* If the runs are misaligned, we cannot merge them. */ + if ((dst->vcn + dst->length) != src->vcn) + return FALSE; + /* If both runs are non-sparse and contiguous, we can merge them. */ + if ((dst->lcn >= 0) && (src->lcn >= 0) && + ((dst->lcn + dst->length) == src->lcn)) + return TRUE; + /* If we are merging two holes, we can merge them. */ + if ((dst->lcn == LCN_HOLE) && (src->lcn == LCN_HOLE)) + return TRUE; + /* Cannot merge. */ + return FALSE; +} + +/** + * __ntfs_rl_merge - merge two runlists without testing if they can be merged + * @dst: original, destination runlist + * @src: new runlist to merge with @dst + * + * Merge the two runlists, writing into the destination runlist @dst. The + * caller must make sure the runlists can be merged or this will corrupt the + * destination runlist. + */ +static void __ntfs_rl_merge(runlist_element *dst, runlist_element *src) +{ + dst->length += src->length; +} + +/** + * ntfs_rl_append - append a runlist after a given element + * @dst: original runlist to be worked on + * @dsize: number of elements in @dst (including end marker) + * @src: runlist to be inserted into @dst + * @ssize: number of elements in @src (excluding end marker) + * @loc: append the new runlist @src after this element in @dst + * + * Append the runlist @src after element @loc in @dst. Merge the right end of + * the new runlist, if necessary. Adjust the size of the hole before the + * appended runlist. + * + * On success, return a pointer to the new, combined, runlist. Note, both + * runlists @dst and @src are deallocated before returning so you cannot use + * the pointers for anything any more. (Strictly speaking the returned runlist + * may be the same as @dst but this is irrelevant.) + * + * On error, return NULL, with errno set to the error code. Both runlists are + * left unmodified. + */ +static runlist_element *ntfs_rl_append(runlist_element *dst, int dsize, + runlist_element *src, int ssize, int loc) +{ + BOOL right = FALSE; /* Right end of @src needs merging */ + int marker; /* End of the inserted runs */ + + if (!dst || !src) { + ntfs_log_debug("Eeek. ntfs_rl_append() invoked with NULL " + "pointer!\n"); + errno = EINVAL; + return NULL; + } + + /* First, check if the right hand end needs merging. */ + if ((loc + 1) < dsize) + right = ntfs_rl_are_mergeable(src + ssize - 1, dst + loc + 1); + + /* Space required: @dst size + @src size, less one if we merged. */ + dst = ntfs_rl_realloc(dst, dsize, dsize + ssize - right); + if (!dst) + return NULL; + /* + * We are guaranteed to succeed from here so can start modifying the + * original runlists. + */ + + /* First, merge the right hand end, if necessary. */ + if (right) + __ntfs_rl_merge(src + ssize - 1, dst + loc + 1); + + /* marker - First run after the @src runs that have been inserted */ + marker = loc + ssize + 1; + + /* Move the tail of @dst out of the way, then copy in @src. */ + ntfs_rl_mm(dst, marker, loc + 1 + right, dsize - loc - 1 - right); + ntfs_rl_mc(dst, loc + 1, src, 0, ssize); + + /* Adjust the size of the preceding hole. */ + dst[loc].length = dst[loc + 1].vcn - dst[loc].vcn; + + /* We may have changed the length of the file, so fix the end marker */ + if (dst[marker].lcn == LCN_ENOENT) + dst[marker].vcn = dst[marker-1].vcn + dst[marker-1].length; + + return dst; +} + +/** + * ntfs_rl_insert - insert a runlist into another + * @dst: original runlist to be worked on + * @dsize: number of elements in @dst (including end marker) + * @src: new runlist to be inserted + * @ssize: number of elements in @src (excluding end marker) + * @loc: insert the new runlist @src before this element in @dst + * + * Insert the runlist @src before element @loc in the runlist @dst. Merge the + * left end of the new runlist, if necessary. Adjust the size of the hole + * after the inserted runlist. + * + * On success, return a pointer to the new, combined, runlist. Note, both + * runlists @dst and @src are deallocated before returning so you cannot use + * the pointers for anything any more. (Strictly speaking the returned runlist + * may be the same as @dst but this is irrelevant.) + * + * On error, return NULL, with errno set to the error code. Both runlists are + * left unmodified. + */ +static runlist_element *ntfs_rl_insert(runlist_element *dst, int dsize, + runlist_element *src, int ssize, int loc) +{ + BOOL left = FALSE; /* Left end of @src needs merging */ + BOOL disc = FALSE; /* Discontinuity between @dst and @src */ + int marker; /* End of the inserted runs */ + + if (!dst || !src) { + ntfs_log_debug("Eeek. ntfs_rl_insert() invoked with NULL " + "pointer!\n"); + errno = EINVAL; + return NULL; + } + + /* disc => Discontinuity between the end of @dst and the start of @src. + * This means we might need to insert a "notmapped" run. + */ + if (loc == 0) + disc = (src[0].vcn > 0); + else { + s64 merged_length; + + left = ntfs_rl_are_mergeable(dst + loc - 1, src); + + merged_length = dst[loc - 1].length; + if (left) + merged_length += src->length; + + disc = (src[0].vcn > dst[loc - 1].vcn + merged_length); + } + + /* Space required: @dst size + @src size, less one if we merged, plus + * one if there was a discontinuity. + */ + dst = ntfs_rl_realloc(dst, dsize, dsize + ssize - left + disc); + if (!dst) + return NULL; + /* + * We are guaranteed to succeed from here so can start modifying the + * original runlist. + */ + + if (left) + __ntfs_rl_merge(dst + loc - 1, src); + + /* + * marker - First run after the @src runs that have been inserted + * Nominally: marker = @loc + @ssize (location + number of runs in @src) + * If "left", then the first run in @src has been merged with one in @dst. + * If "disc", then @dst and @src don't meet and we need an extra run to fill the gap. + */ + marker = loc + ssize - left + disc; + + /* Move the tail of @dst out of the way, then copy in @src. */ + ntfs_rl_mm(dst, marker, loc, dsize - loc); + ntfs_rl_mc(dst, loc + disc, src, left, ssize - left); + + /* Adjust the VCN of the first run after the insertion ... */ + dst[marker].vcn = dst[marker - 1].vcn + dst[marker - 1].length; + /* ... and the length. */ + if (dst[marker].lcn == LCN_HOLE || dst[marker].lcn == LCN_RL_NOT_MAPPED) + dst[marker].length = dst[marker + 1].vcn - dst[marker].vcn; + + /* Writing beyond the end of the file and there's a discontinuity. */ + if (disc) { + if (loc > 0) { + dst[loc].vcn = dst[loc - 1].vcn + dst[loc - 1].length; + dst[loc].length = dst[loc + 1].vcn - dst[loc].vcn; + } else { + dst[loc].vcn = 0; + dst[loc].length = dst[loc + 1].vcn; + } + dst[loc].lcn = LCN_RL_NOT_MAPPED; + } + return dst; +} + +/** + * ntfs_rl_replace - overwrite a runlist element with another runlist + * @dst: original runlist to be worked on + * @dsize: number of elements in @dst (including end marker) + * @src: new runlist to be inserted + * @ssize: number of elements in @src (excluding end marker) + * @loc: index in runlist @dst to overwrite with @src + * + * Replace the runlist element @dst at @loc with @src. Merge the left and + * right ends of the inserted runlist, if necessary. + * + * On success, return a pointer to the new, combined, runlist. Note, both + * runlists @dst and @src are deallocated before returning so you cannot use + * the pointers for anything any more. (Strictly speaking the returned runlist + * may be the same as @dst but this is irrelevant.) + * + * On error, return NULL, with errno set to the error code. Both runlists are + * left unmodified. + */ +static runlist_element *ntfs_rl_replace(runlist_element *dst, int dsize, + runlist_element *src, int ssize, + int loc) +{ + signed delta; + BOOL left = FALSE; /* Left end of @src needs merging */ + BOOL right = FALSE; /* Right end of @src needs merging */ + int tail; /* Start of tail of @dst */ + int marker; /* End of the inserted runs */ + + if (!dst || !src) { + ntfs_log_debug("Eeek. ntfs_rl_replace() invoked with NULL " + "pointer!\n"); + errno = EINVAL; + return NULL; + } + + /* First, see if the left and right ends need merging. */ + if ((loc + 1) < dsize) + right = ntfs_rl_are_mergeable(src + ssize - 1, dst + loc + 1); + if (loc > 0) + left = ntfs_rl_are_mergeable(dst + loc - 1, src); + + /* Allocate some space. We'll need less if the left, right, or both + * ends get merged. The -1 accounts for the run being replaced. + */ + delta = ssize - 1 - left - right; + if (delta > 0) { + dst = ntfs_rl_realloc(dst, dsize, dsize + delta); + if (!dst) + return NULL; + } + /* + * We are guaranteed to succeed from here so can start modifying the + * original runlists. + */ + + /* First, merge the left and right ends, if necessary. */ + if (right) + __ntfs_rl_merge(src + ssize - 1, dst + loc + 1); + if (left) + __ntfs_rl_merge(dst + loc - 1, src); + + /* + * tail - Offset of the tail of @dst + * Nominally: @tail = @loc + 1 (location, skipping the replaced run) + * If "right", then one of @dst's runs is already merged into @src. + */ + tail = loc + right + 1; + + /* + * marker - First run after the @src runs that have been inserted + * Nominally: @marker = @loc + @ssize (location + number of runs in @src) + * If "left", then the first run in @src has been merged with one in @dst. + */ + marker = loc + ssize - left; + + /* Move the tail of @dst out of the way, then copy in @src. */ + ntfs_rl_mm(dst, marker, tail, dsize - tail); + ntfs_rl_mc(dst, loc, src, left, ssize - left); + + /* We may have changed the length of the file, so fix the end marker */ + if (((dsize - tail) > 0) && (dst[marker].lcn == LCN_ENOENT)) + dst[marker].vcn = dst[marker - 1].vcn + dst[marker - 1].length; + + return dst; +} + +/** + * ntfs_rl_split - insert a runlist into the centre of a hole + * @dst: original runlist to be worked on + * @dsize: number of elements in @dst (including end marker) + * @src: new runlist to be inserted + * @ssize: number of elements in @src (excluding end marker) + * @loc: index in runlist @dst at which to split and insert @src + * + * Split the runlist @dst at @loc into two and insert @new in between the two + * fragments. No merging of runlists is necessary. Adjust the size of the + * holes either side. + * + * On success, return a pointer to the new, combined, runlist. Note, both + * runlists @dst and @src are deallocated before returning so you cannot use + * the pointers for anything any more. (Strictly speaking the returned runlist + * may be the same as @dst but this is irrelevant.) + * + * On error, return NULL, with errno set to the error code. Both runlists are + * left unmodified. + */ +static runlist_element *ntfs_rl_split(runlist_element *dst, int dsize, + runlist_element *src, int ssize, int loc) +{ + if (!dst || !src) { + ntfs_log_debug("Eeek. ntfs_rl_split() invoked with NULL pointer!\n"); + errno = EINVAL; + return NULL; + } + + /* Space required: @dst size + @src size + one new hole. */ + dst = ntfs_rl_realloc(dst, dsize, dsize + ssize + 1); + if (!dst) + return dst; + /* + * We are guaranteed to succeed from here so can start modifying the + * original runlists. + */ + + /* Move the tail of @dst out of the way, then copy in @src. */ + ntfs_rl_mm(dst, loc + 1 + ssize, loc, dsize - loc); + ntfs_rl_mc(dst, loc + 1, src, 0, ssize); + + /* Adjust the size of the holes either size of @src. */ + dst[loc].length = dst[loc+1].vcn - dst[loc].vcn; + dst[loc+ssize+1].vcn = dst[loc+ssize].vcn + dst[loc+ssize].length; + dst[loc+ssize+1].length = dst[loc+ssize+2].vcn - dst[loc+ssize+1].vcn; + + return dst; +} + + +/** + * ntfs_runlists_merge_i - see ntfs_runlists_merge + */ +static runlist_element *ntfs_runlists_merge_i(runlist_element *drl, + runlist_element *srl) +{ + int di, si; /* Current index into @[ds]rl. */ + int sstart; /* First index with lcn > LCN_RL_NOT_MAPPED. */ + int dins; /* Index into @drl at which to insert @srl. */ + int dend, send; /* Last index into @[ds]rl. */ + int dfinal, sfinal; /* The last index into @[ds]rl with + lcn >= LCN_HOLE. */ + int marker = 0; + VCN marker_vcn = 0; + + ntfs_log_debug("dst:\n"); + ntfs_debug_runlist_dump(drl); + ntfs_log_debug("src:\n"); + ntfs_debug_runlist_dump(srl); + + /* Check for silly calling... */ + if (!srl) + return drl; + + /* Check for the case where the first mapping is being done now. */ + if (!drl) { + drl = srl; + /* Complete the source runlist if necessary. */ + if (drl[0].vcn) { + /* Scan to the end of the source runlist. */ + for (dend = 0; drl[dend].length; dend++) + ; + dend++; + drl = ntfs_rl_realloc(drl, dend, dend + 1); + if (!drl) + return drl; + /* Insert start element at the front of the runlist. */ + ntfs_rl_mm(drl, 1, 0, dend); + drl[0].vcn = 0; + drl[0].lcn = LCN_RL_NOT_MAPPED; + drl[0].length = drl[1].vcn; + } + goto finished; + } + + si = di = 0; + + /* Skip any unmapped start element(s) in the source runlist. */ + while (srl[si].length && srl[si].lcn < (LCN)LCN_HOLE) + si++; + + /* Can't have an entirely unmapped source runlist. */ + if (!srl[si].length) { + errno = EINVAL; + ntfs_log_perror("%s: unmapped source runlist", __FUNCTION__); + return NULL; + } + + /* Record the starting points. */ + sstart = si; + + /* + * Skip forward in @drl until we reach the position where @srl needs to + * be inserted. If we reach the end of @drl, @srl just needs to be + * appended to @drl. + */ + for (; drl[di].length; di++) { + if (drl[di].vcn + drl[di].length > srl[sstart].vcn) + break; + } + dins = di; + + /* Sanity check for illegal overlaps. */ + if ((drl[di].vcn == srl[si].vcn) && (drl[di].lcn >= 0) && + (srl[si].lcn >= 0)) { + errno = ERANGE; + ntfs_log_perror("Run lists overlap. Cannot merge"); + return NULL; + } + + /* Scan to the end of both runlists in order to know their sizes. */ + for (send = si; srl[send].length; send++) + ; + for (dend = di; drl[dend].length; dend++) + ; + + if (srl[send].lcn == (LCN)LCN_ENOENT) + marker_vcn = srl[marker = send].vcn; + + /* Scan to the last element with lcn >= LCN_HOLE. */ + for (sfinal = send; sfinal >= 0 && srl[sfinal].lcn < LCN_HOLE; sfinal--) + ; + for (dfinal = dend; dfinal >= 0 && drl[dfinal].lcn < LCN_HOLE; dfinal--) + ; + + { + BOOL start; + BOOL finish; + int ds = dend + 1; /* Number of elements in drl & srl */ + int ss = sfinal - sstart + 1; + + start = ((drl[dins].lcn < LCN_RL_NOT_MAPPED) || /* End of file */ + (drl[dins].vcn == srl[sstart].vcn)); /* Start of hole */ + finish = ((drl[dins].lcn >= LCN_RL_NOT_MAPPED) && /* End of file */ + ((drl[dins].vcn + drl[dins].length) <= /* End of hole */ + (srl[send - 1].vcn + srl[send - 1].length))); + + /* Or we'll lose an end marker */ + if (finish && !drl[dins].length) + ss++; + if (marker && (drl[dins].vcn + drl[dins].length > srl[send - 1].vcn)) + finish = FALSE; + + ntfs_log_debug("dfinal = %i, dend = %i\n", dfinal, dend); + ntfs_log_debug("sstart = %i, sfinal = %i, send = %i\n", sstart, sfinal, send); + ntfs_log_debug("start = %i, finish = %i\n", start, finish); + ntfs_log_debug("ds = %i, ss = %i, dins = %i\n", ds, ss, dins); + + if (start) { + if (finish) + drl = ntfs_rl_replace(drl, ds, srl + sstart, ss, dins); + else + drl = ntfs_rl_insert(drl, ds, srl + sstart, ss, dins); + } else { + if (finish) + drl = ntfs_rl_append(drl, ds, srl + sstart, ss, dins); + else + drl = ntfs_rl_split(drl, ds, srl + sstart, ss, dins); + } + if (!drl) { + ntfs_log_perror("Merge failed"); + return drl; + } + free(srl); + if (marker) { + ntfs_log_debug("Triggering marker code.\n"); + for (ds = dend; drl[ds].length; ds++) + ; + /* We only need to care if @srl ended after @drl. */ + if (drl[ds].vcn <= marker_vcn) { + int slots = 0; + + if (drl[ds].vcn == marker_vcn) { + ntfs_log_debug("Old marker = %lli, replacing with " + "LCN_ENOENT.\n", + (long long)drl[ds].lcn); + drl[ds].lcn = (LCN)LCN_ENOENT; + goto finished; + } + /* + * We need to create an unmapped runlist element in + * @drl or extend an existing one before adding the + * ENOENT terminator. + */ + if (drl[ds].lcn == (LCN)LCN_ENOENT) { + ds--; + slots = 1; + } + if (drl[ds].lcn != (LCN)LCN_RL_NOT_MAPPED) { + /* Add an unmapped runlist element. */ + if (!slots) { + /* FIXME/TODO: We need to have the + * extra memory already! (AIA) + */ + drl = ntfs_rl_realloc(drl, ds, ds + 2); + if (!drl) + goto critical_error; + slots = 2; + } + ds++; + /* Need to set vcn if it isn't set already. */ + if (slots != 1) + drl[ds].vcn = drl[ds - 1].vcn + + drl[ds - 1].length; + drl[ds].lcn = (LCN)LCN_RL_NOT_MAPPED; + /* We now used up a slot. */ + slots--; + } + drl[ds].length = marker_vcn - drl[ds].vcn; + /* Finally add the ENOENT terminator. */ + ds++; + if (!slots) { + /* FIXME/TODO: We need to have the extra + * memory already! (AIA) + */ + drl = ntfs_rl_realloc(drl, ds, ds + 1); + if (!drl) + goto critical_error; + } + drl[ds].vcn = marker_vcn; + drl[ds].lcn = (LCN)LCN_ENOENT; + drl[ds].length = (s64)0; + } + } + } + +finished: + /* The merge was completed successfully. */ + ntfs_log_debug("Merged runlist:\n"); + ntfs_debug_runlist_dump(drl); + return drl; + +critical_error: + /* Critical error! We cannot afford to fail here. */ + ntfs_log_perror("libntfs: Critical error"); + ntfs_log_debug("Forcing segmentation fault!\n"); + marker_vcn = ((runlist*)NULL)->lcn; + return drl; +} + +/** + * ntfs_runlists_merge - merge two runlists into one + * @drl: original runlist to be worked on + * @srl: new runlist to be merged into @drl + * + * First we sanity check the two runlists @srl and @drl to make sure that they + * are sensible and can be merged. The runlist @srl must be either after the + * runlist @drl or completely within a hole (or unmapped region) in @drl. + * + * Merging of runlists is necessary in two cases: + * 1. When attribute lists are used and a further extent is being mapped. + * 2. When new clusters are allocated to fill a hole or extend a file. + * + * There are four possible ways @srl can be merged. It can: + * - be inserted at the beginning of a hole, + * - split the hole in two and be inserted between the two fragments, + * - be appended at the end of a hole, or it can + * - replace the whole hole. + * It can also be appended to the end of the runlist, which is just a variant + * of the insert case. + * + * On success, return a pointer to the new, combined, runlist. Note, both + * runlists @drl and @srl are deallocated before returning so you cannot use + * the pointers for anything any more. (Strictly speaking the returned runlist + * may be the same as @dst but this is irrelevant.) + * + * On error, return NULL, with errno set to the error code. Both runlists are + * left unmodified. The following error codes are defined: + * ENOMEM Not enough memory to allocate runlist array. + * EINVAL Invalid parameters were passed in. + * ERANGE The runlists overlap and cannot be merged. + */ +runlist_element *ntfs_runlists_merge(runlist_element *drl, + runlist_element *srl) +{ + runlist_element *rl; + + ntfs_log_enter("Entering\n"); + rl = ntfs_runlists_merge_i(drl, srl); + ntfs_log_leave("\n"); + return rl; +} + +/** + * ntfs_mapping_pairs_decompress - convert mapping pairs array to runlist + * @vol: ntfs volume on which the attribute resides + * @attr: attribute record whose mapping pairs array to decompress + * @old_rl: optional runlist in which to insert @attr's runlist + * + * Decompress the attribute @attr's mapping pairs array into a runlist. On + * success, return the decompressed runlist. + * + * If @old_rl is not NULL, decompressed runlist is inserted into the + * appropriate place in @old_rl and the resultant, combined runlist is + * returned. The original @old_rl is deallocated. + * + * On error, return NULL with errno set to the error code. @old_rl is left + * unmodified in that case. + * + * The following error codes are defined: + * ENOMEM Not enough memory to allocate runlist array. + * EIO Corrupt runlist. + * EINVAL Invalid parameters were passed in. + * ERANGE The two runlists overlap. + * + * FIXME: For now we take the conceptionally simplest approach of creating the + * new runlist disregarding the already existing one and then splicing the + * two into one, if that is possible (we check for overlap and discard the new + * runlist if overlap present before returning NULL, with errno = ERANGE). + */ +static runlist_element *ntfs_mapping_pairs_decompress_i(const ntfs_volume *vol, + const ATTR_RECORD *attr, runlist_element *old_rl) +{ + VCN vcn; /* Current vcn. */ + LCN lcn; /* Current lcn. */ + s64 deltaxcn; /* Change in [vl]cn. */ + runlist_element *rl; /* The output runlist. */ + const u8 *buf; /* Current position in mapping pairs array. */ + const u8 *attr_end; /* End of attribute. */ + int err, rlsize; /* Size of runlist buffer. */ + u16 rlpos; /* Current runlist position in units of + runlist_elements. */ + u8 b; /* Current byte offset in buf. */ + + ntfs_log_trace("Entering for attr 0x%x.\n", + (unsigned)le32_to_cpu(attr->type)); + /* Make sure attr exists and is non-resident. */ + if (!attr || !attr->non_resident || + sle64_to_cpu(attr->lowest_vcn) < (VCN)0) { + errno = EINVAL; + return NULL; + } + /* Start at vcn = lowest_vcn and lcn 0. */ + vcn = sle64_to_cpu(attr->lowest_vcn); + lcn = 0; + /* Get start of the mapping pairs array. */ + buf = (const u8*)attr + le16_to_cpu(attr->mapping_pairs_offset); + attr_end = (const u8*)attr + le32_to_cpu(attr->length); + if (buf < (const u8*)attr || buf > attr_end) { + ntfs_log_debug("Corrupt attribute.\n"); + errno = EIO; + return NULL; + } + /* Current position in runlist array. */ + rlpos = 0; + /* Allocate first 4kiB block and set current runlist size to 4kiB. */ + rlsize = 0x1000; + rl = ntfs_malloc(rlsize); + if (!rl) + return NULL; + /* Insert unmapped starting element if necessary. */ + if (vcn) { + rl->vcn = (VCN)0; + rl->lcn = (LCN)LCN_RL_NOT_MAPPED; + rl->length = vcn; + rlpos++; + } + while (buf < attr_end && *buf) { + /* + * Allocate more memory if needed, including space for the + * not-mapped and terminator elements. + */ + if ((int)((rlpos + 3) * sizeof(*old_rl)) > rlsize) { + runlist_element *rl2; + + rlsize += 0x1000; + rl2 = realloc(rl, rlsize); + if (!rl2) { + int eo = errno; + free(rl); + errno = eo; + return NULL; + } + rl = rl2; + } + /* Enter the current vcn into the current runlist element. */ + rl[rlpos].vcn = vcn; + /* + * Get the change in vcn, i.e. the run length in clusters. + * Doing it this way ensures that we signextend negative values. + * A negative run length doesn't make any sense, but hey, I + * didn't make up the NTFS specs and Windows NT4 treats the run + * length as a signed value so that's how it is... + */ + b = *buf & 0xf; + if (b) { + if (buf + b > attr_end) + goto io_error; + for (deltaxcn = (s8)buf[b--]; b; b--) + deltaxcn = (deltaxcn << 8) + buf[b]; + } else { /* The length entry is compulsory. */ + ntfs_log_debug("Missing length entry in mapping pairs " + "array.\n"); + deltaxcn = (s64)-1; + } + /* + * Assume a negative length to indicate data corruption and + * hence clean-up and return NULL. + */ + if (deltaxcn < 0) { + ntfs_log_debug("Invalid length in mapping pairs array.\n"); + goto err_out; + } + /* + * Enter the current run length into the current runlist + * element. + */ + rl[rlpos].length = deltaxcn; + /* Increment the current vcn by the current run length. */ + vcn += deltaxcn; + /* + * There might be no lcn change at all, as is the case for + * sparse clusters on NTFS 3.0+, in which case we set the lcn + * to LCN_HOLE. + */ + if (!(*buf & 0xf0)) + rl[rlpos].lcn = (LCN)LCN_HOLE; + else { + /* Get the lcn change which really can be negative. */ + u8 b2 = *buf & 0xf; + b = b2 + ((*buf >> 4) & 0xf); + if (buf + b > attr_end) + goto io_error; + for (deltaxcn = (s8)buf[b--]; b > b2; b--) + deltaxcn = (deltaxcn << 8) + buf[b]; + /* Change the current lcn to it's new value. */ + lcn += deltaxcn; +#ifdef DEBUG + /* + * On NTFS 1.2-, apparently can have lcn == -1 to + * indicate a hole. But we haven't verified ourselves + * whether it is really the lcn or the deltaxcn that is + * -1. So if either is found give us a message so we + * can investigate it further! + */ + if (vol->major_ver < 3) { + if (deltaxcn == (LCN)-1) + ntfs_log_debug("lcn delta == -1\n"); + if (lcn == (LCN)-1) + ntfs_log_debug("lcn == -1\n"); + } +#endif + /* Check lcn is not below -1. */ + if (lcn < (LCN)-1) { + ntfs_log_debug("Invalid LCN < -1 in mapping pairs " + "array.\n"); + goto err_out; + } + /* Enter the current lcn into the runlist element. */ + rl[rlpos].lcn = lcn; + } + /* Get to the next runlist element. */ + rlpos++; + /* Increment the buffer position to the next mapping pair. */ + buf += (*buf & 0xf) + ((*buf >> 4) & 0xf) + 1; + } + if (buf >= attr_end) + goto io_error; + /* + * If there is a highest_vcn specified, it must be equal to the final + * vcn in the runlist - 1, or something has gone badly wrong. + */ + deltaxcn = sle64_to_cpu(attr->highest_vcn); + if (deltaxcn && vcn - 1 != deltaxcn) { +mpa_err: + ntfs_log_debug("Corrupt mapping pairs array in non-resident " + "attribute.\n"); + goto err_out; + } + /* Setup not mapped runlist element if this is the base extent. */ + if (!attr->lowest_vcn) { + VCN max_cluster; + + max_cluster = ((sle64_to_cpu(attr->allocated_size) + + vol->cluster_size - 1) >> + vol->cluster_size_bits) - 1; + /* + * A highest_vcn of zero means this is a single extent + * attribute so simply terminate the runlist with LCN_ENOENT). + */ + if (deltaxcn) { + /* + * If there is a difference between the highest_vcn and + * the highest cluster, the runlist is either corrupt + * or, more likely, there are more extents following + * this one. + */ + if (deltaxcn < max_cluster) { + ntfs_log_debug("More extents to follow; deltaxcn = " + "0x%llx, max_cluster = 0x%llx\n", + (long long)deltaxcn, + (long long)max_cluster); + rl[rlpos].vcn = vcn; + vcn += rl[rlpos].length = max_cluster - deltaxcn; + rl[rlpos].lcn = (LCN)LCN_RL_NOT_MAPPED; + rlpos++; + } else if (deltaxcn > max_cluster) { + ntfs_log_debug("Corrupt attribute. deltaxcn = " + "0x%llx, max_cluster = 0x%llx\n", + (long long)deltaxcn, + (long long)max_cluster); + goto mpa_err; + } + } + rl[rlpos].lcn = (LCN)LCN_ENOENT; + } else /* Not the base extent. There may be more extents to follow. */ + rl[rlpos].lcn = (LCN)LCN_RL_NOT_MAPPED; + + /* Setup terminating runlist element. */ + rl[rlpos].vcn = vcn; + rl[rlpos].length = (s64)0; + /* If no existing runlist was specified, we are done. */ + if (!old_rl) { + ntfs_log_debug("Mapping pairs array successfully decompressed:\n"); + ntfs_debug_runlist_dump(rl); + return rl; + } + /* Now combine the new and old runlists checking for overlaps. */ + old_rl = ntfs_runlists_merge(old_rl, rl); + if (old_rl) + return old_rl; + err = errno; + free(rl); + ntfs_log_debug("Failed to merge runlists.\n"); + errno = err; + return NULL; +io_error: + ntfs_log_debug("Corrupt attribute.\n"); +err_out: + free(rl); + errno = EIO; + return NULL; +} + +runlist_element *ntfs_mapping_pairs_decompress(const ntfs_volume *vol, + const ATTR_RECORD *attr, runlist_element *old_rl) +{ + runlist_element *rle; + + ntfs_log_enter("Entering\n"); + rle = ntfs_mapping_pairs_decompress_i(vol, attr, old_rl); + ntfs_log_leave("\n"); + return rle; +} + +/** + * ntfs_rl_vcn_to_lcn - convert a vcn into a lcn given a runlist + * @rl: runlist to use for conversion + * @vcn: vcn to convert + * + * Convert the virtual cluster number @vcn of an attribute into a logical + * cluster number (lcn) of a device using the runlist @rl to map vcns to their + * corresponding lcns. + * + * Since lcns must be >= 0, we use negative return values with special meaning: + * + * Return value Meaning / Description + * ================================================== + * -1 = LCN_HOLE Hole / not allocated on disk. + * -2 = LCN_RL_NOT_MAPPED This is part of the runlist which has not been + * inserted into the runlist yet. + * -3 = LCN_ENOENT There is no such vcn in the attribute. + * -4 = LCN_EINVAL Input parameter error. + */ +LCN ntfs_rl_vcn_to_lcn(const runlist_element *rl, const VCN vcn) +{ + int i; + + if (vcn < (VCN)0) + return (LCN)LCN_EINVAL; + /* + * If rl is NULL, assume that we have found an unmapped runlist. The + * caller can then attempt to map it and fail appropriately if + * necessary. + */ + if (!rl) + return (LCN)LCN_RL_NOT_MAPPED; + + /* Catch out of lower bounds vcn. */ + if (vcn < rl[0].vcn) + return (LCN)LCN_ENOENT; + + for (i = 0; rl[i].length; i++) { + if (vcn < rl[i+1].vcn) { + if (rl[i].lcn >= (LCN)0) + return rl[i].lcn + (vcn - rl[i].vcn); + return rl[i].lcn; + } + } + /* + * The terminator element is setup to the correct value, i.e. one of + * LCN_HOLE, LCN_RL_NOT_MAPPED, or LCN_ENOENT. + */ + if (rl[i].lcn < (LCN)0) + return rl[i].lcn; + /* Just in case... We could replace this with BUG() some day. */ + return (LCN)LCN_ENOENT; +} + +/** + * ntfs_rl_pread - gather read from disk + * @vol: ntfs volume to read from + * @rl: runlist specifying where to read the data from + * @pos: byte position within runlist @rl at which to begin the read + * @count: number of bytes to read + * @b: data buffer into which to read from disk + * + * This function will read @count bytes from the volume @vol to the data buffer + * @b gathering the data as specified by the runlist @rl. The read begins at + * offset @pos into the runlist @rl. + * + * On success, return the number of successfully read bytes. If this number is + * lower than @count this means that the read reached end of file or that an + * error was encountered during the read so that the read is partial. 0 means + * nothing was read (also return 0 when @count is 0). + * + * On error and nothing has been read, return -1 with errno set appropriately + * to the return code of ntfs_pread(), or to EINVAL in case of invalid + * arguments. + * + * NOTE: If we encounter EOF while reading we return EIO because we assume that + * the run list must point to valid locations within the ntfs volume. + */ +s64 ntfs_rl_pread(const ntfs_volume *vol, const runlist_element *rl, + const s64 pos, s64 count, void *b) +{ + s64 bytes_read, to_read, ofs, total; + int err = EIO; + + if (!vol || !rl || pos < 0 || count < 0) { + errno = EINVAL; + ntfs_log_perror("Failed to read runlist [vol: %p rl: %p " + "pos: %lld count: %lld]", vol, rl, + (long long)pos, (long long)count); + return -1; + } + if (!count) + return count; + /* Seek in @rl to the run containing @pos. */ + for (ofs = 0; rl->length && (ofs + (rl->length << + vol->cluster_size_bits) <= pos); rl++) + ofs += (rl->length << vol->cluster_size_bits); + /* Offset in the run at which to begin reading. */ + ofs = pos - ofs; + for (total = 0LL; count; rl++, ofs = 0) { + if (!rl->length) + goto rl_err_out; + if (rl->lcn < (LCN)0) { + if (rl->lcn != (LCN)LCN_HOLE) + goto rl_err_out; + /* It is a hole. Just fill buffer @b with zeroes. */ + to_read = min(count, (rl->length << + vol->cluster_size_bits) - ofs); + memset(b, 0, to_read); + /* Update counters and proceed with next run. */ + total += to_read; + count -= to_read; + b = (u8*)b + to_read; + continue; + } + /* It is a real lcn, read it from the volume. */ + to_read = min(count, (rl->length << vol->cluster_size_bits) - + ofs); +retry: + bytes_read = ntfs_pread(vol->dev, (rl->lcn << + vol->cluster_size_bits) + ofs, to_read, b); + /* If everything ok, update progress counters and continue. */ + if (bytes_read > 0) { + total += bytes_read; + count -= bytes_read; + b = (u8*)b + bytes_read; + continue; + } + /* If the syscall was interrupted, try again. */ + if (bytes_read == (s64)-1 && errno == EINTR) + goto retry; + if (bytes_read == (s64)-1) + err = errno; + goto rl_err_out; + } + /* Finally, return the number of bytes read. */ + return total; +rl_err_out: + if (total) + return total; + errno = err; + return -1; +} + +/** + * ntfs_rl_pwrite - scatter write to disk + * @vol: ntfs volume to write to + * @rl: runlist entry specifying where to write the data to + * @ofs: offset in file for runlist element indicated in @rl + * @pos: byte position from runlist beginning at which to begin the write + * @count: number of bytes to write + * @b: data buffer to write to disk + * + * This function will write @count bytes from data buffer @b to the volume @vol + * scattering the data as specified by the runlist @rl. The write begins at + * offset @pos into the runlist @rl. If a run is sparse then the related buffer + * data is ignored which means that the caller must ensure they are consistent. + * + * On success, return the number of successfully written bytes. If this number + * is lower than @count this means that the write has been interrupted in + * flight or that an error was encountered during the write so that the write + * is partial. 0 means nothing was written (also return 0 when @count is 0). + * + * On error and nothing has been written, return -1 with errno set + * appropriately to the return code of ntfs_pwrite(), or to to EINVAL in case + * of invalid arguments. + */ +s64 ntfs_rl_pwrite(const ntfs_volume *vol, const runlist_element *rl, + s64 ofs, const s64 pos, s64 count, void *b) +{ + s64 written, to_write, total = 0; + int err = EIO; + + if (!vol || !rl || pos < 0 || count < 0) { + errno = EINVAL; + ntfs_log_perror("Failed to write runlist [vol: %p rl: %p " + "pos: %lld count: %lld]", vol, rl, + (long long)pos, (long long)count); + goto errno_set; + } + if (!count) + goto out; + /* Seek in @rl to the run containing @pos. */ + while (rl->length && (ofs + (rl->length << + vol->cluster_size_bits) <= pos)) { + ofs += (rl->length << vol->cluster_size_bits); + rl++; + } + /* Offset in the run at which to begin writing. */ + ofs = pos - ofs; + for (total = 0LL; count; rl++, ofs = 0) { + if (!rl->length) + goto rl_err_out; + if (rl->lcn < (LCN)0) { + + if (rl->lcn != (LCN)LCN_HOLE) + goto rl_err_out; + + to_write = min(count, (rl->length << + vol->cluster_size_bits) - ofs); + + total += to_write; + count -= to_write; + b = (u8*)b + to_write; + continue; + } + /* It is a real lcn, write it to the volume. */ + to_write = min(count, (rl->length << vol->cluster_size_bits) - + ofs); +retry: + if (!NVolReadOnly(vol)) + written = ntfs_pwrite(vol->dev, (rl->lcn << + vol->cluster_size_bits) + ofs, + to_write, b); + else + written = to_write; + /* If everything ok, update progress counters and continue. */ + if (written > 0) { + total += written; + count -= written; + b = (u8*)b + written; + continue; + } + /* If the syscall was interrupted, try again. */ + if (written == (s64)-1 && errno == EINTR) + goto retry; + if (written == (s64)-1) + err = errno; + goto rl_err_out; + } +out: + return total; +rl_err_out: + if (total) + goto out; + errno = err; +errno_set: + total = -1; + goto out; +} + +/** + * ntfs_get_nr_significant_bytes - get number of bytes needed to store a number + * @n: number for which to get the number of bytes for + * + * Return the number of bytes required to store @n unambiguously as + * a signed number. + * + * This is used in the context of the mapping pairs array to determine how + * many bytes will be needed in the array to store a given logical cluster + * number (lcn) or a specific run length. + * + * Return the number of bytes written. This function cannot fail. + */ +int ntfs_get_nr_significant_bytes(const s64 n) +{ + u64 l; + int i; + + l = (n < 0 ? ~n : n); + i = 1; + if (l >= 128) { + l >>= 7; + do { + i++; + l >>= 8; + } while (l); + } + return i; +} + +/** + * ntfs_get_size_for_mapping_pairs - get bytes needed for mapping pairs array + * @vol: ntfs volume (needed for the ntfs version) + * @rl: runlist for which to determine the size of the mapping pairs + * @start_vcn: vcn at which to start the mapping pairs array + * + * Walk the runlist @rl and calculate the size in bytes of the mapping pairs + * array corresponding to the runlist @rl, starting at vcn @start_vcn. This + * for example allows us to allocate a buffer of the right size when building + * the mapping pairs array. + * + * If @rl is NULL, just return 1 (for the single terminator byte). + * + * Return the calculated size in bytes on success. On error, return -1 with + * errno set to the error code. The following error codes are defined: + * EINVAL - Run list contains unmapped elements. Make sure to only pass + * fully mapped runlists to this function. + * - @start_vcn is invalid. + * EIO - The runlist is corrupt. + */ +int ntfs_get_size_for_mapping_pairs(const ntfs_volume *vol, + const runlist_element *rl, const VCN start_vcn, int max_size) +{ + LCN prev_lcn; + int rls; + + if (start_vcn < 0) { + ntfs_log_trace("start_vcn %lld (should be >= 0)\n", + (long long) start_vcn); + errno = EINVAL; + goto errno_set; + } + if (!rl) { + if (start_vcn) { + ntfs_log_trace("rl NULL, start_vcn %lld (should be > 0)\n", + (long long) start_vcn); + errno = EINVAL; + goto errno_set; + } + rls = 1; + goto out; + } + /* Skip to runlist element containing @start_vcn. */ + while (rl->length && start_vcn >= rl[1].vcn) + rl++; + if ((!rl->length && start_vcn > rl->vcn) || start_vcn < rl->vcn) { + errno = EINVAL; + goto errno_set; + } + prev_lcn = 0; + /* Always need the terminating zero byte. */ + rls = 1; + /* Do the first partial run if present. */ + if (start_vcn > rl->vcn) { + s64 delta; + + /* We know rl->length != 0 already. */ + if (rl->length < 0 || rl->lcn < LCN_HOLE) + goto err_out; + delta = start_vcn - rl->vcn; + /* Header byte + length. */ + rls += 1 + ntfs_get_nr_significant_bytes(rl->length - delta); + /* + * If the logical cluster number (lcn) denotes a hole and we + * are on NTFS 3.0+, we don't store it at all, i.e. we need + * zero space. On earlier NTFS versions we just store the lcn. + * Note: this assumes that on NTFS 1.2-, holes are stored with + * an lcn of -1 and not a delta_lcn of -1 (unless both are -1). + */ + if (rl->lcn >= 0 || vol->major_ver < 3) { + prev_lcn = rl->lcn; + if (rl->lcn >= 0) + prev_lcn += delta; + /* Change in lcn. */ + rls += ntfs_get_nr_significant_bytes(prev_lcn); + } + /* Go to next runlist element. */ + rl++; + } + /* Do the full runs. */ + for (; rl->length && (rls <= max_size); rl++) { + if (rl->length < 0 || rl->lcn < LCN_HOLE) + goto err_out; + /* Header byte + length. */ + rls += 1 + ntfs_get_nr_significant_bytes(rl->length); + /* + * If the logical cluster number (lcn) denotes a hole and we + * are on NTFS 3.0+, we don't store it at all, i.e. we need + * zero space. On earlier NTFS versions we just store the lcn. + * Note: this assumes that on NTFS 1.2-, holes are stored with + * an lcn of -1 and not a delta_lcn of -1 (unless both are -1). + */ + if (rl->lcn >= 0 || vol->major_ver < 3) { + /* Change in lcn. */ + rls += ntfs_get_nr_significant_bytes(rl->lcn - + prev_lcn); + prev_lcn = rl->lcn; + } + } +out: + return rls; +err_out: + if (rl->lcn == LCN_RL_NOT_MAPPED) + errno = EINVAL; + else + errno = EIO; +errno_set: + rls = -1; + goto out; +} + +/** + * ntfs_write_significant_bytes - write the significant bytes of a number + * @dst: destination buffer to write to + * @dst_max: pointer to last byte of destination buffer for bounds checking + * @n: number whose significant bytes to write + * + * Store in @dst, the minimum bytes of the number @n which are required to + * identify @n unambiguously as a signed number, taking care not to exceed + * @dest_max, the maximum position within @dst to which we are allowed to + * write. + * + * This is used when building the mapping pairs array of a runlist to compress + * a given logical cluster number (lcn) or a specific run length to the minimum + * size possible. + * + * Return the number of bytes written on success. On error, i.e. the + * destination buffer @dst is too small, return -1 with errno set ENOSPC. + */ +int ntfs_write_significant_bytes(u8 *dst, const u8 *dst_max, const s64 n) +{ + s64 l = n; + int i; + s8 j; + + i = 0; + do { + if (dst > dst_max) + goto err_out; + *dst++ = l & 0xffLL; + l >>= 8; + i++; + } while (l != 0LL && l != -1LL); + j = (n >> 8 * (i - 1)) & 0xff; + /* If the sign bit is wrong, we need an extra byte. */ + if (n < 0LL && j >= 0) { + if (dst > dst_max) + goto err_out; + i++; + *dst = (u8)-1; + } else if (n > 0LL && j < 0) { + if (dst > dst_max) + goto err_out; + i++; + *dst = 0; + } + return i; +err_out: + errno = ENOSPC; + return -1; +} + +/** + * ntfs_mapping_pairs_build - build the mapping pairs array from a runlist + * @vol: ntfs volume (needed for the ntfs version) + * @dst: destination buffer to which to write the mapping pairs array + * @dst_len: size of destination buffer @dst in bytes + * @rl: runlist for which to build the mapping pairs array + * @start_vcn: vcn at which to start the mapping pairs array + * @stop_vcn: first vcn outside destination buffer on success or ENOSPC error + * + * Create the mapping pairs array from the runlist @rl, starting at vcn + * @start_vcn and save the array in @dst. @dst_len is the size of @dst in + * bytes and it should be at least equal to the value obtained by calling + * ntfs_get_size_for_mapping_pairs(). + * + * If @rl is NULL, just write a single terminator byte to @dst. + * + * On success or ENOSPC error, if @stop_vcn is not NULL, *@stop_vcn is set to + * the first vcn outside the destination buffer. Note that on error @dst has + * been filled with all the mapping pairs that will fit, thus it can be treated + * as partial success, in that a new attribute extent needs to be created or the + * next extent has to be used and the mapping pairs build has to be continued + * with @start_vcn set to *@stop_vcn. + * + * Return 0 on success. On error, return -1 with errno set to the error code. + * The following error codes are defined: + * EINVAL - Run list contains unmapped elements. Make sure to only pass + * fully mapped runlists to this function. + * - @start_vcn is invalid. + * EIO - The runlist is corrupt. + * ENOSPC - The destination buffer is too small. + */ +int ntfs_mapping_pairs_build(const ntfs_volume *vol, u8 *dst, + const int dst_len, const runlist_element *rl, + const VCN start_vcn, runlist_element const **stop_rl) +{ + LCN prev_lcn; + u8 *dst_max, *dst_next; + s8 len_len, lcn_len; + int ret = 0; + + if (start_vcn < 0) + goto val_err; + if (!rl) { + if (start_vcn) + goto val_err; + if (stop_rl) + *stop_rl = rl; + if (dst_len < 1) + goto nospc_err; + goto ok; + } + /* Skip to runlist element containing @start_vcn. */ + while (rl->length && start_vcn >= rl[1].vcn) + rl++; + if ((!rl->length && start_vcn > rl->vcn) || start_vcn < rl->vcn) + goto val_err; + /* + * @dst_max is used for bounds checking in + * ntfs_write_significant_bytes(). + */ + dst_max = dst + dst_len - 1; + prev_lcn = 0; + /* Do the first partial run if present. */ + if (start_vcn > rl->vcn) { + s64 delta; + + /* We know rl->length != 0 already. */ + if (rl->length < 0 || rl->lcn < LCN_HOLE) + goto err_out; + delta = start_vcn - rl->vcn; + /* Write length. */ + len_len = ntfs_write_significant_bytes(dst + 1, dst_max, + rl->length - delta); + if (len_len < 0) + goto size_err; + /* + * If the logical cluster number (lcn) denotes a hole and we + * are on NTFS 3.0+, we don't store it at all, i.e. we need + * zero space. On earlier NTFS versions we just write the lcn + * change. FIXME: Do we need to write the lcn change or just + * the lcn in that case? Not sure as I have never seen this + * case on NT4. - We assume that we just need to write the lcn + * change until someone tells us otherwise... (AIA) + */ + if (rl->lcn >= 0 || vol->major_ver < 3) { + prev_lcn = rl->lcn; + if (rl->lcn >= 0) + prev_lcn += delta; + /* Write change in lcn. */ + lcn_len = ntfs_write_significant_bytes(dst + 1 + + len_len, dst_max, prev_lcn); + if (lcn_len < 0) + goto size_err; + } else + lcn_len = 0; + dst_next = dst + len_len + lcn_len + 1; + if (dst_next > dst_max) + goto size_err; + /* Update header byte. */ + *dst = lcn_len << 4 | len_len; + /* Position at next mapping pairs array element. */ + dst = dst_next; + /* Go to next runlist element. */ + rl++; + } + /* Do the full runs. */ + for (; rl->length; rl++) { + if (rl->length < 0 || rl->lcn < LCN_HOLE) + goto err_out; + /* Write length. */ + len_len = ntfs_write_significant_bytes(dst + 1, dst_max, + rl->length); + if (len_len < 0) + goto size_err; + /* + * If the logical cluster number (lcn) denotes a hole and we + * are on NTFS 3.0+, we don't store it at all, i.e. we need + * zero space. On earlier NTFS versions we just write the lcn + * change. FIXME: Do we need to write the lcn change or just + * the lcn in that case? Not sure as I have never seen this + * case on NT4. - We assume that we just need to write the lcn + * change until someone tells us otherwise... (AIA) + */ + if (rl->lcn >= 0 || vol->major_ver < 3) { + /* Write change in lcn. */ + lcn_len = ntfs_write_significant_bytes(dst + 1 + + len_len, dst_max, rl->lcn - prev_lcn); + if (lcn_len < 0) + goto size_err; + prev_lcn = rl->lcn; + } else + lcn_len = 0; + dst_next = dst + len_len + lcn_len + 1; + if (dst_next > dst_max) + goto size_err; + /* Update header byte. */ + *dst = lcn_len << 4 | len_len; + /* Position at next mapping pairs array element. */ + dst += 1 + len_len + lcn_len; + } + /* Set stop vcn. */ + if (stop_rl) + *stop_rl = rl; +ok: + /* Add terminator byte. */ + *dst = 0; +out: + return ret; +size_err: + /* Set stop vcn. */ + if (stop_rl) + *stop_rl = rl; + /* Add terminator byte. */ + *dst = 0; +nospc_err: + errno = ENOSPC; + goto errno_set; +val_err: + errno = EINVAL; + goto errno_set; +err_out: + if (rl->lcn == LCN_RL_NOT_MAPPED) + errno = EINVAL; + else + errno = EIO; +errno_set: + ret = -1; + goto out; +} + +/** + * ntfs_rl_truncate - truncate a runlist starting at a specified vcn + * @arl: address of runlist to truncate + * @start_vcn: first vcn which should be cut off + * + * Truncate the runlist *@arl starting at vcn @start_vcn as well as the memory + * buffer holding the runlist. + * + * Return 0 on success and -1 on error with errno set to the error code. + * + * NOTE: @arl is the address of the runlist. We need the address so we can + * modify the pointer to the runlist with the new, reallocated memory buffer. + */ +int ntfs_rl_truncate(runlist **arl, const VCN start_vcn) +{ + runlist *rl; + BOOL is_end = FALSE; + + if (!arl || !*arl) { + errno = EINVAL; + if (!arl) + ntfs_log_perror("rl_truncate error: arl: %p", arl); + else + ntfs_log_perror("rl_truncate error:" + " arl: %p *arl: %p", arl, *arl); + return -1; + } + + rl = *arl; + + if (start_vcn < rl->vcn) { + errno = EINVAL; + ntfs_log_perror("Start_vcn lies outside front of runlist"); + return -1; + } + + /* Find the starting vcn in the run list. */ + while (rl->length) { + if (start_vcn < rl[1].vcn) + break; + rl++; + } + + if (!rl->length) { + errno = EIO; + ntfs_log_trace("Truncating already truncated runlist?\n"); + return -1; + } + + /* Truncate the run. */ + rl->length = start_vcn - rl->vcn; + + /* + * If a run was partially truncated, make the following runlist + * element a terminator instead of the truncated runlist + * element itself. + */ + if (rl->length) { + ++rl; + if (!rl->length) + is_end = TRUE; + rl->vcn = start_vcn; + rl->length = 0; + } + rl->lcn = (LCN)LCN_ENOENT; + /** + * Reallocate memory if necessary. + * FIXME: Below code is broken, because runlist allocations must be + * a multiply of 4096. The code caused crashes and corruptions. + */ +/* + if (!is_end) { + size_t new_size = (rl - *arl + 1) * sizeof(runlist_element); + rl = realloc(*arl, new_size); + if (rl) + *arl = rl; + } +*/ + return 0; +} + +/** + * ntfs_rl_sparse - check whether runlist have sparse regions or not. + * @rl: runlist to check + * + * Return 1 if have, 0 if not, -1 on error with errno set to the error code. + */ +int ntfs_rl_sparse(runlist *rl) +{ + runlist *rlc; + + if (!rl) { + errno = EINVAL; + ntfs_log_perror("%s: ", __FUNCTION__); + return -1; + } + + for (rlc = rl; rlc->length; rlc++) + if (rlc->lcn < 0) { + if (rlc->lcn != LCN_HOLE) { + errno = EINVAL; + ntfs_log_perror("%s: bad runlist", __FUNCTION__); + return -1; + } + return 1; + } + return 0; +} + +/** + * ntfs_rl_get_compressed_size - calculate length of non sparse regions + * @vol: ntfs volume (need for cluster size) + * @rl: runlist to calculate for + * + * Return compressed size or -1 on error with errno set to the error code. + */ +s64 ntfs_rl_get_compressed_size(ntfs_volume *vol, runlist *rl) +{ + runlist *rlc; + s64 ret = 0; + + if (!rl) { + errno = EINVAL; + ntfs_log_perror("%s: ", __FUNCTION__); + return -1; + } + + for (rlc = rl; rlc->length; rlc++) { + if (rlc->lcn < 0) { + if (rlc->lcn != LCN_HOLE) { + errno = EINVAL; + ntfs_log_perror("%s: bad runlist", __FUNCTION__); + return -1; + } + } else + ret += rlc->length; + } + return ret << vol->cluster_size_bits; +} + + +#ifdef NTFS_TEST +/** + * test_rl_helper + */ +#define MKRL(R,V,L,S) \ + (R)->vcn = V; \ + (R)->lcn = L; \ + (R)->length = S; +/* +} +*/ +/** + * test_rl_dump_runlist - Runlist test: Display the contents of a runlist + * @rl: + * + * Description... + * + * Returns: + */ +static void test_rl_dump_runlist(const runlist_element *rl) +{ + int abbr = 0; /* abbreviate long lists */ + int len = 0; + int i; + const char *lcn_str[5] = { "HOLE", "NOTMAP", "ENOENT", "XXXX" }; + + if (!rl) { + printf(" Run list not present.\n"); + return; + } + + if (abbr) + for (len = 0; rl[len].length; len++) ; + + printf(" VCN LCN len\n"); + for (i = 0; ; i++, rl++) { + LCN lcn = rl->lcn; + + if ((abbr) && (len > 20)) { + if (i == 4) + printf(" ...\n"); + if ((i > 3) && (i < (len - 3))) + continue; + } + + if (lcn < (LCN)0) { + int ind = -lcn - 1; + + if (ind > -LCN_ENOENT - 1) + ind = 3; + printf("%8lld %8s %8lld\n", + rl->vcn, lcn_str[ind], rl->length); + } else + printf("%8lld %8lld %8lld\n", + rl->vcn, rl->lcn, rl->length); + if (!rl->length) + break; + } + if ((abbr) && (len > 20)) + printf(" (%d entries)\n", len+1); + printf("\n"); +} + +/** + * test_rl_runlists_merge - Runlist test: Merge two runlists + * @drl: + * @srl: + * + * Description... + * + * Returns: + */ +static runlist_element * test_rl_runlists_merge(runlist_element *drl, runlist_element *srl) +{ + runlist_element *res = NULL; + + printf("dst:\n"); + test_rl_dump_runlist(drl); + printf("src:\n"); + test_rl_dump_runlist(srl); + + res = ntfs_runlists_merge(drl, srl); + + printf("res:\n"); + test_rl_dump_runlist(res); + + return res; +} + +/** + * test_rl_read_buffer - Runlist test: Read a file containing a runlist + * @file: + * @buf: + * @bufsize: + * + * Description... + * + * Returns: + */ +static int test_rl_read_buffer(const char *file, u8 *buf, int bufsize) +{ + FILE *fptr; + + fptr = fopen(file, "r"); + if (!fptr) { + printf("open %s\n", file); + return 0; + } + + if (fread(buf, bufsize, 1, fptr) == 99) { + printf("read %s\n", file); + return 0; + } + + fclose(fptr); + return 1; +} + +/** + * test_rl_pure_src - Runlist test: Complicate the simple tests a little + * @contig: + * @multi: + * @vcn: + * @len: + * + * Description... + * + * Returns: + */ +static runlist_element * test_rl_pure_src(BOOL contig, BOOL multi, int vcn, int len) +{ + runlist_element *result; + int fudge; + + if (contig) + fudge = 0; + else + fudge = 999; + + result = ntfs_malloc(4096); + if (!result) + return NULL; + + if (multi) { + MKRL(result+0, vcn + (0*len/4), fudge + vcn + 1000 + (0*len/4), len / 4) + MKRL(result+1, vcn + (1*len/4), fudge + vcn + 1000 + (1*len/4), len / 4) + MKRL(result+2, vcn + (2*len/4), fudge + vcn + 1000 + (2*len/4), len / 4) + MKRL(result+3, vcn + (3*len/4), fudge + vcn + 1000 + (3*len/4), len / 4) + MKRL(result+4, vcn + (4*len/4), LCN_RL_NOT_MAPPED, 0) + } else { + MKRL(result+0, vcn, fudge + vcn + 1000, len) + MKRL(result+1, vcn + len, LCN_RL_NOT_MAPPED, 0) + } + return result; +} + +/** + * test_rl_pure_test - Runlist test: Perform tests using simple runlists + * @test: + * @contig: + * @multi: + * @vcn: + * @len: + * @file: + * @size: + * + * Description... + * + * Returns: + */ +static void test_rl_pure_test(int test, BOOL contig, BOOL multi, int vcn, int len, runlist_element *file, int size) +{ + runlist_element *src; + runlist_element *dst; + runlist_element *res; + + src = test_rl_pure_src(contig, multi, vcn, len); + dst = ntfs_malloc(4096); + if (!src || !dst) { + printf("Test %2d ---------- FAILED! (no free memory?)\n", test); + return; + } + + memcpy(dst, file, size); + + printf("Test %2d ----------\n", test); + res = test_rl_runlists_merge(dst, src); + + free(res); +} + +/** + * test_rl_pure - Runlist test: Create tests using simple runlists + * @contig: + * @multi: + * + * Description... + * + * Returns: + */ +static void test_rl_pure(char *contig, char *multi) +{ + /* VCN, LCN, len */ + static runlist_element file1[] = { + { 0, -1, 100 }, /* HOLE */ + { 100, 1100, 100 }, /* DATA */ + { 200, -1, 100 }, /* HOLE */ + { 300, 1300, 100 }, /* DATA */ + { 400, -1, 100 }, /* HOLE */ + { 500, -3, 0 } /* NOENT */ + }; + static runlist_element file2[] = { + { 0, 1000, 100 }, /* DATA */ + { 100, -1, 100 }, /* HOLE */ + { 200, -3, 0 } /* NOENT */ + }; + static runlist_element file3[] = { + { 0, 1000, 100 }, /* DATA */ + { 100, -3, 0 } /* NOENT */ + }; + static runlist_element file4[] = { + { 0, -3, 0 } /* NOENT */ + }; + static runlist_element file5[] = { + { 0, -2, 100 }, /* NOTMAP */ + { 100, 1100, 100 }, /* DATA */ + { 200, -2, 100 }, /* NOTMAP */ + { 300, 1300, 100 }, /* DATA */ + { 400, -2, 100 }, /* NOTMAP */ + { 500, -3, 0 } /* NOENT */ + }; + static runlist_element file6[] = { + { 0, 1000, 100 }, /* DATA */ + { 100, -2, 100 }, /* NOTMAP */ + { 200, -3, 0 } /* NOENT */ + }; + BOOL c, m; + + if (strcmp(contig, "contig") == 0) + c = TRUE; + else if (strcmp(contig, "noncontig") == 0) + c = FALSE; + else { + printf("rl pure [contig|noncontig] [single|multi]\n"); + return; + } + if (strcmp(multi, "multi") == 0) + m = TRUE; + else if (strcmp(multi, "single") == 0) + m = FALSE; + else { + printf("rl pure [contig|noncontig] [single|multi]\n"); + return; + } + + test_rl_pure_test(1, c, m, 0, 40, file1, sizeof(file1)); + test_rl_pure_test(2, c, m, 40, 40, file1, sizeof(file1)); + test_rl_pure_test(3, c, m, 60, 40, file1, sizeof(file1)); + test_rl_pure_test(4, c, m, 0, 100, file1, sizeof(file1)); + test_rl_pure_test(5, c, m, 200, 40, file1, sizeof(file1)); + test_rl_pure_test(6, c, m, 240, 40, file1, sizeof(file1)); + test_rl_pure_test(7, c, m, 260, 40, file1, sizeof(file1)); + test_rl_pure_test(8, c, m, 200, 100, file1, sizeof(file1)); + test_rl_pure_test(9, c, m, 400, 40, file1, sizeof(file1)); + test_rl_pure_test(10, c, m, 440, 40, file1, sizeof(file1)); + test_rl_pure_test(11, c, m, 460, 40, file1, sizeof(file1)); + test_rl_pure_test(12, c, m, 400, 100, file1, sizeof(file1)); + test_rl_pure_test(13, c, m, 160, 100, file2, sizeof(file2)); + test_rl_pure_test(14, c, m, 100, 140, file2, sizeof(file2)); + test_rl_pure_test(15, c, m, 200, 40, file2, sizeof(file2)); + test_rl_pure_test(16, c, m, 240, 40, file2, sizeof(file2)); + test_rl_pure_test(17, c, m, 100, 40, file3, sizeof(file3)); + test_rl_pure_test(18, c, m, 140, 40, file3, sizeof(file3)); + test_rl_pure_test(19, c, m, 0, 40, file4, sizeof(file4)); + test_rl_pure_test(20, c, m, 40, 40, file4, sizeof(file4)); + test_rl_pure_test(21, c, m, 0, 40, file5, sizeof(file5)); + test_rl_pure_test(22, c, m, 40, 40, file5, sizeof(file5)); + test_rl_pure_test(23, c, m, 60, 40, file5, sizeof(file5)); + test_rl_pure_test(24, c, m, 0, 100, file5, sizeof(file5)); + test_rl_pure_test(25, c, m, 200, 40, file5, sizeof(file5)); + test_rl_pure_test(26, c, m, 240, 40, file5, sizeof(file5)); + test_rl_pure_test(27, c, m, 260, 40, file5, sizeof(file5)); + test_rl_pure_test(28, c, m, 200, 100, file5, sizeof(file5)); + test_rl_pure_test(29, c, m, 400, 40, file5, sizeof(file5)); + test_rl_pure_test(30, c, m, 440, 40, file5, sizeof(file5)); + test_rl_pure_test(31, c, m, 460, 40, file5, sizeof(file5)); + test_rl_pure_test(32, c, m, 400, 100, file5, sizeof(file5)); + test_rl_pure_test(33, c, m, 160, 100, file6, sizeof(file6)); + test_rl_pure_test(34, c, m, 100, 140, file6, sizeof(file6)); +} + +/** + * test_rl_zero - Runlist test: Merge a zero-length runlist + * + * Description... + * + * Returns: + */ +static void test_rl_zero(void) +{ + runlist_element *jim = NULL; + runlist_element *bob = NULL; + + bob = calloc(3, sizeof(runlist_element)); + if (!bob) + return; + + MKRL(bob+0, 10, 99, 5) + MKRL(bob+1, 15, LCN_RL_NOT_MAPPED, 0) + + jim = test_rl_runlists_merge(jim, bob); + if (!jim) + return; + + free(jim); +} + +/** + * test_rl_frag_combine - Runlist test: Perform tests using fragmented files + * @vol: + * @attr1: + * @attr2: + * @attr3: + * + * Description... + * + * Returns: + */ +static void test_rl_frag_combine(ntfs_volume *vol, ATTR_RECORD *attr1, ATTR_RECORD *attr2, ATTR_RECORD *attr3) +{ + runlist_element *run1; + runlist_element *run2; + runlist_element *run3; + + run1 = ntfs_mapping_pairs_decompress(vol, attr1, NULL); + if (!run1) + return; + + run2 = ntfs_mapping_pairs_decompress(vol, attr2, NULL); + if (!run2) + return; + + run1 = test_rl_runlists_merge(run1, run2); + + run3 = ntfs_mapping_pairs_decompress(vol, attr3, NULL); + if (!run3) + return; + + run1 = test_rl_runlists_merge(run1, run3); + + free(run1); +} + +/** + * test_rl_frag - Runlist test: Create tests using very fragmented files + * @test: + * + * Description... + * + * Returns: + */ +static void test_rl_frag(char *test) +{ + ntfs_volume vol; + ATTR_RECORD *attr1 = ntfs_malloc(1024); + ATTR_RECORD *attr2 = ntfs_malloc(1024); + ATTR_RECORD *attr3 = ntfs_malloc(1024); + + if (!attr1 || !attr2 || !attr3) + goto out; + + vol.sb = NULL; + vol.sector_size_bits = 9; + vol.cluster_size = 2048; + vol.cluster_size_bits = 11; + vol.major_ver = 3; + + if (!test_rl_read_buffer("runlist-data/attr1.bin", (u8*) attr1, 1024)) + goto out; + if (!test_rl_read_buffer("runlist-data/attr2.bin", (u8*) attr2, 1024)) + goto out; + if (!test_rl_read_buffer("runlist-data/attr3.bin", (u8*) attr3, 1024)) + goto out; + + if (strcmp(test, "123") == 0) test_rl_frag_combine(&vol, attr1, attr2, attr3); + else if (strcmp(test, "132") == 0) test_rl_frag_combine(&vol, attr1, attr3, attr2); + else if (strcmp(test, "213") == 0) test_rl_frag_combine(&vol, attr2, attr1, attr3); + else if (strcmp(test, "231") == 0) test_rl_frag_combine(&vol, attr2, attr3, attr1); + else if (strcmp(test, "312") == 0) test_rl_frag_combine(&vol, attr3, attr1, attr2); + else if (strcmp(test, "321") == 0) test_rl_frag_combine(&vol, attr3, attr2, attr1); + else + printf("Frag: No such test '%s'\n", test); + +out: + free(attr1); + free(attr2); + free(attr3); +} + +/** + * test_rl_main - Runlist test: Program start (main) + * @argc: + * @argv: + * + * Description... + * + * Returns: + */ +int test_rl_main(int argc, char *argv[]) +{ + if ((argc == 2) && (strcmp(argv[1], "zero") == 0)) test_rl_zero(); + else if ((argc == 3) && (strcmp(argv[1], "frag") == 0)) test_rl_frag(argv[2]); + else if ((argc == 4) && (strcmp(argv[1], "pure") == 0)) test_rl_pure(argv[2], argv[3]); + else + printf("rl [zero|frag|pure] {args}\n"); + + return 0; +} + +#endif + |