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HardenedBSD/sbin/fsck_msdosfs/dir.c
John F. Carr deeb1d3402 fsck_msdosfs: do not call checksize() if the cluster is bad 
PR:	276464
MFC after:	1 week
2024-01-21 01:20:24 +02:00

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29 KiB
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/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2019 Google LLC
* Copyright (C) 1995, 1996, 1997 Wolfgang Solfrank
* Copyright (c) 1995 Martin Husemann
* Some structure declaration borrowed from Paul Popelka
* (paulp@uts.amdahl.com), see /sys/msdosfs/ for reference.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: dir.c,v 1.20 2006/06/05 16:51:18 christos Exp $");
#endif /* not lint */
#include <assert.h>
#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <unistd.h>
#include <time.h>
#include <sys/param.h>
#include "ext.h"
#include "fsutil.h"
#define SLOT_EMPTY 0x00 /* slot has never been used */
#define SLOT_E5 0x05 /* the real value is 0xe5 */
#define SLOT_DELETED 0xe5 /* file in this slot deleted */
#define ATTR_NORMAL 0x00 /* normal file */
#define ATTR_READONLY 0x01 /* file is readonly */
#define ATTR_HIDDEN 0x02 /* file is hidden */
#define ATTR_SYSTEM 0x04 /* file is a system file */
#define ATTR_VOLUME 0x08 /* entry is a volume label */
#define ATTR_DIRECTORY 0x10 /* entry is a directory name */
#define ATTR_ARCHIVE 0x20 /* file is new or modified */
#define ATTR_WIN95 0x0f /* long name record */
/*
* This is the format of the contents of the deTime field in the direntry
* structure.
* We don't use bitfields because we don't know how compilers for
* arbitrary machines will lay them out.
*/
#define DT_2SECONDS_MASK 0x1F /* seconds divided by 2 */
#define DT_2SECONDS_SHIFT 0
#define DT_MINUTES_MASK 0x7E0 /* minutes */
#define DT_MINUTES_SHIFT 5
#define DT_HOURS_MASK 0xF800 /* hours */
#define DT_HOURS_SHIFT 11
/*
* This is the format of the contents of the deDate field in the direntry
* structure.
*/
#define DD_DAY_MASK 0x1F /* day of month */
#define DD_DAY_SHIFT 0
#define DD_MONTH_MASK 0x1E0 /* month */
#define DD_MONTH_SHIFT 5
#define DD_YEAR_MASK 0xFE00 /* year - 1980 */
#define DD_YEAR_SHIFT 9
/* dir.c */
static struct dosDirEntry *newDosDirEntry(void);
static void freeDosDirEntry(struct dosDirEntry *);
static struct dirTodoNode *newDirTodo(void);
static void freeDirTodo(struct dirTodoNode *);
static char *fullpath(struct dosDirEntry *);
static u_char calcShortSum(u_char *);
static int delete(struct fat_descriptor *, cl_t, int, cl_t, int, int);
static int removede(struct fat_descriptor *, u_char *, u_char *,
cl_t, cl_t, cl_t, char *, int);
static int checksize(struct fat_descriptor *, u_char *, struct dosDirEntry *);
static int readDosDirSection(struct fat_descriptor *, struct dosDirEntry *);
/*
* Manage free dosDirEntry structures.
*/
static struct dosDirEntry *freede;
static struct dosDirEntry *
newDosDirEntry(void)
{
struct dosDirEntry *de;
if (!(de = freede)) {
if (!(de = malloc(sizeof *de)))
return (NULL);
} else
freede = de->next;
return de;
}
static void
freeDosDirEntry(struct dosDirEntry *de)
{
de->next = freede;
freede = de;
}
/*
* The same for dirTodoNode structures.
*/
static struct dirTodoNode *freedt;
static struct dirTodoNode *
newDirTodo(void)
{
struct dirTodoNode *dt;
if (!(dt = freedt)) {
if (!(dt = malloc(sizeof *dt)))
return 0;
} else
freedt = dt->next;
return dt;
}
static void
freeDirTodo(struct dirTodoNode *dt)
{
dt->next = freedt;
freedt = dt;
}
/*
* The stack of unread directories
*/
static struct dirTodoNode *pendingDirectories = NULL;
/*
* Return the full pathname for a directory entry.
*/
static char *
fullpath(struct dosDirEntry *dir)
{
static char namebuf[MAXPATHLEN + 1];
char *cp, *np;
int nl;
cp = namebuf + sizeof namebuf;
*--cp = '\0';
for(;;) {
np = dir->lname[0] ? dir->lname : dir->name;
nl = strlen(np);
if (cp <= namebuf + 1 + nl) {
*--cp = '?';
break;
}
cp -= nl;
memcpy(cp, np, nl);
dir = dir->parent;
if (!dir)
break;
*--cp = '/';
}
return cp;
}
/*
* Calculate a checksum over an 8.3 alias name
*/
static inline u_char
calcShortSum(u_char *p)
{
u_char sum = 0;
int i;
for (i = 0; i < 11; i++) {
sum = (sum << 7)|(sum >> 1); /* rotate right */
sum += p[i];
}
return sum;
}
/*
* Global variables temporarily used during a directory scan
*/
static char longName[DOSLONGNAMELEN] = "";
static u_char *buffer = NULL;
static u_char *delbuf = NULL;
static struct dosDirEntry *rootDir;
static struct dosDirEntry *lostDir;
/*
* Init internal state for a new directory scan.
*/
int
resetDosDirSection(struct fat_descriptor *fat)
{
int rootdir_size, cluster_size;
int ret = FSOK;
size_t len;
struct bootblock *boot;
boot = fat_get_boot(fat);
rootdir_size = boot->bpbRootDirEnts * 32;
cluster_size = boot->bpbSecPerClust * boot->bpbBytesPerSec;
if ((buffer = malloc(len = MAX(rootdir_size, cluster_size))) == NULL) {
perr("No space for directory buffer (%zu)", len);
return FSFATAL;
}
if ((delbuf = malloc(len = cluster_size)) == NULL) {
free(buffer);
perr("No space for directory delbuf (%zu)", len);
return FSFATAL;
}
if ((rootDir = newDosDirEntry()) == NULL) {
free(buffer);
free(delbuf);
perr("No space for directory entry");
return FSFATAL;
}
memset(rootDir, 0, sizeof *rootDir);
if (boot->flags & FAT32) {
if (!fat_is_cl_head(fat, boot->bpbRootClust)) {
pfatal("Root directory doesn't start a cluster chain");
return FSFATAL;
}
rootDir->head = boot->bpbRootClust;
}
return ret;
}
/*
* Cleanup after a directory scan
*/
void
finishDosDirSection(void)
{
struct dirTodoNode *p, *np;
struct dosDirEntry *d, *nd;
for (p = pendingDirectories; p; p = np) {
np = p->next;
freeDirTodo(p);
}
pendingDirectories = NULL;
for (d = rootDir; d; d = nd) {
if ((nd = d->child) != NULL) {
d->child = 0;
continue;
}
if (!(nd = d->next))
nd = d->parent;
freeDosDirEntry(d);
}
rootDir = lostDir = NULL;
free(buffer);
free(delbuf);
buffer = NULL;
delbuf = NULL;
}
/*
* Delete directory entries between startcl, startoff and endcl, endoff.
*/
static int
delete(struct fat_descriptor *fat, cl_t startcl,
int startoff, cl_t endcl, int endoff, int notlast)
{
u_char *s, *e;
off_t off;
int clsz, fd;
struct bootblock *boot;
boot = fat_get_boot(fat);
fd = fat_get_fd(fat);
clsz = boot->bpbSecPerClust * boot->bpbBytesPerSec;
s = delbuf + startoff;
e = delbuf + clsz;
while (fat_is_valid_cl(fat, startcl)) {
if (startcl == endcl) {
if (notlast)
break;
e = delbuf + endoff;
}
off = (startcl - CLUST_FIRST) * boot->bpbSecPerClust + boot->FirstCluster;
off *= boot->bpbBytesPerSec;
if (lseek(fd, off, SEEK_SET) != off) {
perr("Unable to lseek to %" PRId64, off);
return FSFATAL;
}
if (read(fd, delbuf, clsz) != clsz) {
perr("Unable to read directory");
return FSFATAL;
}
while (s < e) {
*s = SLOT_DELETED;
s += 32;
}
if (lseek(fd, off, SEEK_SET) != off) {
perr("Unable to lseek to %" PRId64, off);
return FSFATAL;
}
if (write(fd, delbuf, clsz) != clsz) {
perr("Unable to write directory");
return FSFATAL;
}
if (startcl == endcl)
break;
startcl = fat_get_cl_next(fat, startcl);
s = delbuf;
}
return FSOK;
}
static int
removede(struct fat_descriptor *fat, u_char *start,
u_char *end, cl_t startcl, cl_t endcl, cl_t curcl,
char *path, int type)
{
switch (type) {
case 0:
pwarn("Invalid long filename entry for %s\n", path);
break;
case 1:
pwarn("Invalid long filename entry at end of directory %s\n",
path);
break;
case 2:
pwarn("Invalid long filename entry for volume label\n");
break;
}
if (ask(0, "Remove")) {
if (startcl != curcl) {
if (delete(fat,
startcl, start - buffer,
endcl, end - buffer,
endcl == curcl) == FSFATAL)
return FSFATAL;
start = buffer;
}
/* startcl is < CLUST_FIRST for !FAT32 root */
if ((endcl == curcl) || (startcl < CLUST_FIRST))
for (; start < end; start += 32)
*start = SLOT_DELETED;
return FSDIRMOD;
}
return FSERROR;
}
/*
* Check an in-memory file entry
*/
static int
checksize(struct fat_descriptor *fat, u_char *p, struct dosDirEntry *dir)
{
int ret = FSOK;
size_t chainsize;
u_int64_t physicalSize;
struct bootblock *boot;
boot = fat_get_boot(fat);
/*
* Check size on ordinary files
*/
if (dir->head == CLUST_FREE) {
physicalSize = 0;
} else {
if (!fat_is_valid_cl(fat, dir->head) || !fat_is_cl_head(fat, dir->head)) {
pwarn("Directory entry %s of size %u referencing invalid cluster %u\n",
fullpath(dir), dir->size, dir->head);
if (ask(1, "Truncate")) {
p[28] = p[29] = p[30] = p[31] = 0;
p[26] = p[27] = 0;
if (boot->ClustMask == CLUST32_MASK)
p[20] = p[21] = 0;
dir->size = 0;
dir->head = CLUST_FREE;
return FSDIRMOD;
} else {
return FSERROR;
}
}
ret = checkchain(fat, dir->head, &chainsize);
/*
* Upon return, chainsize would hold the chain length
* that checkchain() was able to validate, but if the user
* refused the proposed repair, it would be unsafe to
* proceed with directory entry fix, so bail out in that
* case.
*/
if (ret == FSERROR) {
return (FSERROR);
}
/*
* The maximum file size on FAT32 is 4GiB - 1, which
* will occupy a cluster chain of exactly 4GiB in
* size. On 32-bit platforms, since size_t is 32-bit,
* it would wrap back to 0.
*/
physicalSize = (u_int64_t)chainsize * boot->ClusterSize;
}
if (physicalSize < dir->size) {
pwarn("size of %s is %u, should at most be %ju\n",
fullpath(dir), dir->size, (uintmax_t)physicalSize);
if (ask(1, "Truncate")) {
dir->size = physicalSize;
p[28] = (u_char)physicalSize;
p[29] = (u_char)(physicalSize >> 8);
p[30] = (u_char)(physicalSize >> 16);
p[31] = (u_char)(physicalSize >> 24);
return FSDIRMOD;
} else
return FSERROR;
} else if (physicalSize - dir->size >= boot->ClusterSize) {
pwarn("%s has too many clusters allocated\n",
fullpath(dir));
if (ask(1, "Drop superfluous clusters")) {
cl_t cl;
u_int32_t sz, len;
for (cl = dir->head, len = sz = 0;
(sz += boot->ClusterSize) < dir->size; len++)
cl = fat_get_cl_next(fat, cl);
clearchain(fat, fat_get_cl_next(fat, cl));
ret = fat_set_cl_next(fat, cl, CLUST_EOF);
return (FSFATMOD | ret);
} else
return FSERROR;
}
return FSOK;
}
static const u_char dot_name[11] = ". ";
static const u_char dotdot_name[11] = ".. ";
/*
* Basic sanity check if the subdirectory have good '.' and '..' entries,
* and they are directory entries. Further sanity checks are performed
* when we traverse into it.
*/
static int
check_subdirectory(struct fat_descriptor *fat, struct dosDirEntry *dir)
{
u_char *buf, *cp;
off_t off;
cl_t cl;
int retval = FSOK;
int fd;
struct bootblock *boot;
boot = fat_get_boot(fat);
fd = fat_get_fd(fat);
cl = dir->head;
if (dir->parent && !fat_is_valid_cl(fat, cl)) {
return FSERROR;
}
if (!(boot->flags & FAT32) && !dir->parent) {
off = boot->bpbResSectors + boot->bpbFATs *
boot->FATsecs;
} else {
off = (cl - CLUST_FIRST) * boot->bpbSecPerClust + boot->FirstCluster;
}
/*
* We only need to check the first two entries of the directory,
* which is found in the first sector of the directory entry,
* so read in only the first sector.
*/
buf = malloc(boot->bpbBytesPerSec);
if (buf == NULL) {
perr("No space for directory buffer (%u)",
boot->bpbBytesPerSec);
return FSFATAL;
}
off *= boot->bpbBytesPerSec;
if (lseek(fd, off, SEEK_SET) != off ||
read(fd, buf, boot->bpbBytesPerSec) != (ssize_t)boot->bpbBytesPerSec) {
perr("Unable to read directory");
free(buf);
return FSFATAL;
}
/*
* Both `.' and `..' must be present and be the first two entries
* and be ATTR_DIRECTORY of a valid subdirectory.
*/
cp = buf;
if (memcmp(cp, dot_name, sizeof(dot_name)) != 0 ||
(cp[11] & ATTR_DIRECTORY) != ATTR_DIRECTORY) {
pwarn("%s: Incorrect `.' for %s.\n", __func__, dir->name);
retval |= FSERROR;
}
cp += 32;
if (memcmp(cp, dotdot_name, sizeof(dotdot_name)) != 0 ||
(cp[11] & ATTR_DIRECTORY) != ATTR_DIRECTORY) {
pwarn("%s: Incorrect `..' for %s. \n", __func__, dir->name);
retval |= FSERROR;
}
free(buf);
return retval;
}
/*
* Read a directory and
* - resolve long name records
* - enter file and directory records into the parent's list
* - push directories onto the todo-stack
*/
static int
readDosDirSection(struct fat_descriptor *fat, struct dosDirEntry *dir)
{
struct bootblock *boot;
struct dosDirEntry dirent, *d;
u_char *p, *vallfn, *invlfn, *empty;
off_t off;
int fd, i, j, k, iosize, entries;
bool is_legacyroot;
cl_t cl, valcl = ~0, invcl = ~0, empcl = ~0;
char *t;
u_int lidx = 0;
int shortSum;
int mod = FSOK;
size_t dirclusters;
#define THISMOD 0x8000 /* Only used within this routine */
boot = fat_get_boot(fat);
fd = fat_get_fd(fat);
cl = dir->head;
if (dir->parent && (!fat_is_valid_cl(fat, cl))) {
/*
* Already handled somewhere else.
*/
return FSOK;
}
shortSum = -1;
vallfn = invlfn = empty = NULL;
/*
* If we are checking the legacy root (for FAT12/FAT16),
* we will operate on the whole directory; otherwise, we
* will operate on one cluster at a time, and also take
* this opportunity to examine the chain.
*
* Derive how many entries we are going to encounter from
* the I/O size.
*/
is_legacyroot = (dir->parent == NULL && !(boot->flags & FAT32));
if (is_legacyroot) {
iosize = boot->bpbRootDirEnts * 32;
entries = boot->bpbRootDirEnts;
} else {
iosize = boot->bpbSecPerClust * boot->bpbBytesPerSec;
entries = iosize / 32;
mod |= checkchain(fat, dir->head, &dirclusters);
}
do {
if (is_legacyroot) {
/*
* Special case for FAT12/FAT16 root -- read
* in the whole root directory.
*/
off = boot->bpbResSectors + boot->bpbFATs *
boot->FATsecs;
} else {
/*
* Otherwise, read in a cluster of the
* directory.
*/
off = (cl - CLUST_FIRST) * boot->bpbSecPerClust + boot->FirstCluster;
}
off *= boot->bpbBytesPerSec;
if (lseek(fd, off, SEEK_SET) != off ||
read(fd, buffer, iosize) != iosize) {
perr("Unable to read directory");
return FSFATAL;
}
for (p = buffer, i = 0; i < entries; i++, p += 32) {
if (dir->fsckflags & DIREMPWARN) {
*p = SLOT_EMPTY;
continue;
}
if (*p == SLOT_EMPTY || *p == SLOT_DELETED) {
if (*p == SLOT_EMPTY) {
dir->fsckflags |= DIREMPTY;
empty = p;
empcl = cl;
}
continue;
}
if (dir->fsckflags & DIREMPTY) {
if (!(dir->fsckflags & DIREMPWARN)) {
pwarn("%s has entries after end of directory\n",
fullpath(dir));
if (ask(1, "Extend")) {
u_char *q;
dir->fsckflags &= ~DIREMPTY;
if (delete(fat,
empcl, empty - buffer,
cl, p - buffer, 1) == FSFATAL)
return FSFATAL;
q = ((empcl == cl) ? empty : buffer);
assert(q != NULL);
for (; q < p; q += 32)
*q = SLOT_DELETED;
mod |= THISMOD|FSDIRMOD;
} else if (ask(0, "Truncate"))
dir->fsckflags |= DIREMPWARN;
}
if (dir->fsckflags & DIREMPWARN) {
*p = SLOT_DELETED;
mod |= THISMOD|FSDIRMOD;
continue;
} else if (dir->fsckflags & DIREMPTY)
mod |= FSERROR;
empty = NULL;
}
if (p[11] == ATTR_WIN95) {
if (*p & LRFIRST) {
if (shortSum != -1) {
if (!invlfn) {
invlfn = vallfn;
invcl = valcl;
}
}
memset(longName, 0, sizeof longName);
shortSum = p[13];
vallfn = p;
valcl = cl;
} else if (shortSum != p[13]
|| lidx != (*p & LRNOMASK)) {
if (!invlfn) {
invlfn = vallfn;
invcl = valcl;
}
if (!invlfn) {
invlfn = p;
invcl = cl;
}
vallfn = NULL;
}
lidx = *p & LRNOMASK;
if (lidx == 0) {
pwarn("invalid long name\n");
if (!invlfn) {
invlfn = vallfn;
invcl = valcl;
}
vallfn = NULL;
continue;
}
t = longName + --lidx * 13;
for (k = 1; k < 11 && t < longName +
sizeof(longName); k += 2) {
if (!p[k] && !p[k + 1])
break;
*t++ = p[k];
/*
* Warn about those unusable chars in msdosfs here? XXX
*/
if (p[k + 1])
t[-1] = '?';
}
if (k >= 11)
for (k = 14; k < 26 && t < longName + sizeof(longName); k += 2) {
if (!p[k] && !p[k + 1])
break;
*t++ = p[k];
if (p[k + 1])
t[-1] = '?';
}
if (k >= 26)
for (k = 28; k < 32 && t < longName + sizeof(longName); k += 2) {
if (!p[k] && !p[k + 1])
break;
*t++ = p[k];
if (p[k + 1])
t[-1] = '?';
}
if (t >= longName + sizeof(longName)) {
pwarn("long filename too long\n");
if (!invlfn) {
invlfn = vallfn;
invcl = valcl;
}
vallfn = NULL;
}
if (p[26] | (p[27] << 8)) {
pwarn("long filename record cluster start != 0\n");
if (!invlfn) {
invlfn = vallfn;
invcl = cl;
}
vallfn = NULL;
}
continue; /* long records don't carry further
* information */
}
/*
* This is a standard msdosfs directory entry.
*/
memset(&dirent, 0, sizeof dirent);
/*
* it's a short name record, but we need to know
* more, so get the flags first.
*/
dirent.flags = p[11];
/*
* Translate from 850 to ISO here XXX
*/
for (j = 0; j < 8; j++)
dirent.name[j] = p[j];
dirent.name[8] = '\0';
for (k = 7; k >= 0 && dirent.name[k] == ' '; k--)
dirent.name[k] = '\0';
if (k < 0 || dirent.name[k] != '\0')
k++;
if (dirent.name[0] == SLOT_E5)
dirent.name[0] = 0xe5;
if (dirent.flags & ATTR_VOLUME) {
if (vallfn || invlfn) {
mod |= removede(fat,
invlfn ? invlfn : vallfn, p,
invlfn ? invcl : valcl, -1, 0,
fullpath(dir), 2);
vallfn = NULL;
invlfn = NULL;
}
continue;
}
if (p[8] != ' ')
dirent.name[k++] = '.';
for (j = 0; j < 3; j++)
dirent.name[k++] = p[j+8];
dirent.name[k] = '\0';
for (k--; k >= 0 && dirent.name[k] == ' '; k--)
dirent.name[k] = '\0';
if (vallfn && shortSum != calcShortSum(p)) {
if (!invlfn) {
invlfn = vallfn;
invcl = valcl;
}
vallfn = NULL;
}
dirent.head = p[26] | (p[27] << 8);
if (boot->ClustMask == CLUST32_MASK)
dirent.head |= (p[20] << 16) | (p[21] << 24);
dirent.size = p[28] | (p[29] << 8) | (p[30] << 16) | (p[31] << 24);
if (vallfn) {
strlcpy(dirent.lname, longName,
sizeof(dirent.lname));
longName[0] = '\0';
shortSum = -1;
}
dirent.parent = dir;
dirent.next = dir->child;
if (invlfn) {
mod |= k = removede(fat,
invlfn, vallfn ? vallfn : p,
invcl, vallfn ? valcl : cl, cl,
fullpath(&dirent), 0);
if (mod & FSFATAL)
return FSFATAL;
if (vallfn
? (valcl == cl && vallfn != buffer)
: p != buffer)
if (k & FSDIRMOD)
mod |= THISMOD;
}
vallfn = NULL; /* not used any longer */
invlfn = NULL;
/*
* Check if the directory entry is sane.
*
* '.' and '..' are skipped, their sanity is
* checked somewhere else.
*
* For everything else, check if we have a new,
* valid cluster chain (beginning of a file or
* directory that was never previously claimed
* by another file) when it's a non-empty file
* or a directory. The sanity of the cluster
* chain is checked at a later time when we
* traverse into the directory, or examine the
* file's directory entry.
*
* The only possible fix is to delete the entry
* if it's a directory; for file, we have to
* truncate the size to 0.
*/
if (!(dirent.flags & ATTR_DIRECTORY) ||
(strcmp(dirent.name, ".") != 0 &&
strcmp(dirent.name, "..") != 0)) {
if ((dirent.size != 0 || (dirent.flags & ATTR_DIRECTORY)) &&
((!fat_is_valid_cl(fat, dirent.head) ||
!fat_is_cl_head(fat, dirent.head)))) {
if (!fat_is_valid_cl(fat, dirent.head)) {
pwarn("%s starts with cluster out of range(%u)\n",
fullpath(&dirent),
dirent.head);
} else {
pwarn("%s doesn't start a new cluster chain\n",
fullpath(&dirent));
}
if (dirent.flags & ATTR_DIRECTORY) {
if (ask(0, "Remove")) {
*p = SLOT_DELETED;
mod |= THISMOD|FSDIRMOD;
} else
mod |= FSERROR;
continue;
} else {
if (ask(1, "Truncate")) {
p[28] = p[29] = p[30] = p[31] = 0;
p[26] = p[27] = 0;
if (boot->ClustMask == CLUST32_MASK)
p[20] = p[21] = 0;
dirent.size = 0;
dirent.head = 0;
mod |= THISMOD|FSDIRMOD;
} else
mod |= FSERROR;
}
}
}
if (dirent.flags & ATTR_DIRECTORY) {
/*
* gather more info for directories
*/
struct dirTodoNode *n;
if (dirent.size) {
pwarn("Directory %s has size != 0\n",
fullpath(&dirent));
if (ask(1, "Correct")) {
p[28] = p[29] = p[30] = p[31] = 0;
dirent.size = 0;
mod |= THISMOD|FSDIRMOD;
} else
mod |= FSERROR;
}
/*
* handle `.' and `..' specially
*/
if (strcmp(dirent.name, ".") == 0) {
if (dirent.head != dir->head) {
pwarn("`.' entry in %s has incorrect start cluster\n",
fullpath(dir));
if (ask(1, "Correct")) {
dirent.head = dir->head;
p[26] = (u_char)dirent.head;
p[27] = (u_char)(dirent.head >> 8);
if (boot->ClustMask == CLUST32_MASK) {
p[20] = (u_char)(dirent.head >> 16);
p[21] = (u_char)(dirent.head >> 24);
}
mod |= THISMOD|FSDIRMOD;
} else
mod |= FSERROR;
}
continue;
} else if (strcmp(dirent.name, "..") == 0) {
if (dir->parent) { /* XXX */
if (!dir->parent->parent) {
if (dirent.head) {
pwarn("`..' entry in %s has non-zero start cluster\n",
fullpath(dir));
if (ask(1, "Correct")) {
dirent.head = 0;
p[26] = p[27] = 0;
if (boot->ClustMask == CLUST32_MASK)
p[20] = p[21] = 0;
mod |= THISMOD|FSDIRMOD;
} else
mod |= FSERROR;
}
} else if (dirent.head != dir->parent->head) {
pwarn("`..' entry in %s has incorrect start cluster\n",
fullpath(dir));
if (ask(1, "Correct")) {
dirent.head = dir->parent->head;
p[26] = (u_char)dirent.head;
p[27] = (u_char)(dirent.head >> 8);
if (boot->ClustMask == CLUST32_MASK) {
p[20] = (u_char)(dirent.head >> 16);
p[21] = (u_char)(dirent.head >> 24);
}
mod |= THISMOD|FSDIRMOD;
} else
mod |= FSERROR;
}
}
continue;
} else {
/*
* Only one directory entry can point
* to dir->head, it's '.'.
*/
if (dirent.head == dir->head) {
pwarn("%s entry in %s has incorrect start cluster\n",
dirent.name, fullpath(dir));
if (ask(1, "Remove")) {
*p = SLOT_DELETED;
mod |= THISMOD|FSDIRMOD;
} else
mod |= FSERROR;
continue;
} else if ((check_subdirectory(fat,
&dirent) & FSERROR) == FSERROR) {
/*
* A subdirectory should have
* a dot (.) entry and a dot-dot
* (..) entry of ATTR_DIRECTORY,
* we will inspect further when
* traversing into it.
*/
if (ask(1, "Remove")) {
*p = SLOT_DELETED;
mod |= THISMOD|FSDIRMOD;
} else
mod |= FSERROR;
continue;
}
}
/* create directory tree node */
if (!(d = newDosDirEntry())) {
perr("No space for directory");
return FSFATAL;
}
memcpy(d, &dirent, sizeof(struct dosDirEntry));
/* link it into the tree */
dir->child = d;
/* Enter this directory into the todo list */
if (!(n = newDirTodo())) {
perr("No space for todo list");
return FSFATAL;
}
n->next = pendingDirectories;
n->dir = d;
pendingDirectories = n;
} else if (!(mod & FSERROR)) {
mod |= k = checksize(fat, p, &dirent);
if (k & FSDIRMOD)
mod |= THISMOD;
}
boot->NumFiles++;
}
if (is_legacyroot) {
/*
* Don't bother to write back right now because
* we may continue to make modification to the
* non-FAT32 root directory below.
*/
break;
} else if (mod & THISMOD) {
if (lseek(fd, off, SEEK_SET) != off
|| write(fd, buffer, iosize) != iosize) {
perr("Unable to write directory");
return FSFATAL;
}
mod &= ~THISMOD;
}
} while (fat_is_valid_cl(fat, (cl = fat_get_cl_next(fat, cl))));
if (invlfn || vallfn)
mod |= removede(fat,
invlfn ? invlfn : vallfn, p,
invlfn ? invcl : valcl, -1, 0,
fullpath(dir), 1);
/*
* The root directory of non-FAT32 filesystems is in a special
* area and may have been modified above removede() without
* being written out.
*/
if ((mod & FSDIRMOD) && is_legacyroot) {
if (lseek(fd, off, SEEK_SET) != off
|| write(fd, buffer, iosize) != iosize) {
perr("Unable to write directory");
return FSFATAL;
}
mod &= ~THISMOD;
}
return mod & ~THISMOD;
}
int
handleDirTree(struct fat_descriptor *fat)
{
int mod;
mod = readDosDirSection(fat, rootDir);
if (mod & FSFATAL)
return FSFATAL;
/*
* process the directory todo list
*/
while (pendingDirectories) {
struct dosDirEntry *dir = pendingDirectories->dir;
struct dirTodoNode *n = pendingDirectories->next;
/*
* remove TODO entry now, the list might change during
* directory reads
*/
freeDirTodo(pendingDirectories);
pendingDirectories = n;
/*
* handle subdirectory
*/
mod |= readDosDirSection(fat, dir);
if (mod & FSFATAL)
return FSFATAL;
}
return mod;
}
/*
* Try to reconnect a FAT chain into dir
*/
static u_char *lfbuf;
static cl_t lfcl;
static off_t lfoff;
int
reconnect(struct fat_descriptor *fat, cl_t head, size_t length)
{
struct bootblock *boot = fat_get_boot(fat);
struct dosDirEntry d;
int len, dosfs;
u_char *p;
dosfs = fat_get_fd(fat);
if (!ask(1, "Reconnect"))
return FSERROR;
if (!lostDir) {
for (lostDir = rootDir->child; lostDir; lostDir = lostDir->next) {
if (!strcmp(lostDir->name, LOSTDIR))
break;
}
if (!lostDir) { /* Create LOSTDIR? XXX */
pwarn("No %s directory\n", LOSTDIR);
return FSERROR;
}
}
if (!lfbuf) {
lfbuf = malloc(boot->ClusterSize);
if (!lfbuf) {
perr("No space for buffer");
return FSFATAL;
}
p = NULL;
} else
p = lfbuf;
while (1) {
if (p)
for (; p < lfbuf + boot->ClusterSize; p += 32)
if (*p == SLOT_EMPTY
|| *p == SLOT_DELETED)
break;
if (p && p < lfbuf + boot->ClusterSize)
break;
lfcl = p ? fat_get_cl_next(fat, lfcl) : lostDir->head;
if (lfcl < CLUST_FIRST || lfcl >= boot->NumClusters) {
/* Extend LOSTDIR? XXX */
pwarn("No space in %s\n", LOSTDIR);
lfcl = (lostDir->head < boot->NumClusters) ? lostDir->head : 0;
return FSERROR;
}
lfoff = (lfcl - CLUST_FIRST) * boot->ClusterSize
+ boot->FirstCluster * boot->bpbBytesPerSec;
if (lseek(dosfs, lfoff, SEEK_SET) != lfoff
|| (size_t)read(dosfs, lfbuf, boot->ClusterSize) != boot->ClusterSize) {
perr("could not read LOST.DIR");
return FSFATAL;
}
p = lfbuf;
}
boot->NumFiles++;
/* Ensure uniqueness of entry here! XXX */
memset(&d, 0, sizeof d);
/* worst case -1 = 4294967295, 10 digits */
len = snprintf(d.name, sizeof(d.name), "%u", head);
d.flags = 0;
d.head = head;
d.size = length * boot->ClusterSize;
memcpy(p, d.name, len);
memset(p + len, ' ', 11 - len);
memset(p + 11, 0, 32 - 11);
p[26] = (u_char)d.head;
p[27] = (u_char)(d.head >> 8);
if (boot->ClustMask == CLUST32_MASK) {
p[20] = (u_char)(d.head >> 16);
p[21] = (u_char)(d.head >> 24);
}
p[28] = (u_char)d.size;
p[29] = (u_char)(d.size >> 8);
p[30] = (u_char)(d.size >> 16);
p[31] = (u_char)(d.size >> 24);
if (lseek(dosfs, lfoff, SEEK_SET) != lfoff
|| (size_t)write(dosfs, lfbuf, boot->ClusterSize) != boot->ClusterSize) {
perr("could not write LOST.DIR");
return FSFATAL;
}
return FSDIRMOD;
}
void
finishlf(void)
{
if (lfbuf)
free(lfbuf);
lfbuf = NULL;
}
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