freebsd-skq/sbin/fsck_msdosfs/dir.c
Xin LI aa031ef4a3 Prevent OOB access on corrupted msdos directories.
Submitted by:	Veo Zhang <veo live com>
MFC after:	2 weeks
2017-11-30 08:28:17 +00:00

1017 lines
25 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* 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 $");
static const char rcsid[] =
"$FreeBSD$";
#endif /* not lint */
#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(int, struct bootblock *, struct fatEntry *, cl_t, int,
cl_t, int, int);
static int removede(int, struct bootblock *, struct fatEntry *, u_char *,
u_char *, cl_t, cl_t, cl_t, char *, int);
static int checksize(struct bootblock *, struct fatEntry *, u_char *,
struct dosDirEntry *);
static int readDosDirSection(int, struct bootblock *, struct fatEntry *,
struct dosDirEntry *);
/*
* Manage free dosDirEntry structures.
*/
static struct dosDirEntry *freede;
static struct dosDirEntry *
newDosDirEntry(void)
{
struct dosDirEntry *de;
if (!(de = freede)) {
if (!(de = (struct dosDirEntry *)malloc(sizeof *de)))
return 0;
} 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 = (struct dirTodoNode *)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 - 1;
*cp = '\0';
do {
np = dir->lname[0] ? dir->lname : dir->name;
nl = strlen(np);
if ((cp -= nl) <= namebuf + 1)
break;
memcpy(cp, np, nl);
*--cp = '/';
} while ((dir = dir->parent) != NULL);
if (dir)
*--cp = '?';
else
cp++;
return cp;
}
/*
* Calculate a checksum over an 8.3 alias name
*/
static 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 bootblock *boot, struct fatEntry *fat)
{
int b1, b2;
cl_t cl;
int ret = FSOK;
size_t len;
b1 = boot->bpbRootDirEnts * 32;
b2 = boot->bpbSecPerClust * boot->bpbBytesPerSec;
if ((buffer = malloc(len = MAX(b1, b2))) == NULL) {
perr("No space for directory buffer (%zu)", len);
return FSFATAL;
}
if ((delbuf = malloc(len = b2)) == 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 (boot->bpbRootClust < CLUST_FIRST ||
boot->bpbRootClust >= boot->NumClusters) {
pfatal("Root directory starts with cluster out of range(%u)",
boot->bpbRootClust);
return FSFATAL;
}
cl = fat[boot->bpbRootClust].next;
if (cl < CLUST_FIRST
|| (cl >= CLUST_RSRVD && cl< CLUST_EOFS)
|| fat[boot->bpbRootClust].head != boot->bpbRootClust) {
if (cl == CLUST_FREE)
pwarn("Root directory starts with free cluster\n");
else if (cl >= CLUST_RSRVD)
pwarn("Root directory starts with cluster marked %s\n",
rsrvdcltype(cl));
else {
pfatal("Root directory doesn't start a cluster chain");
return FSFATAL;
}
if (ask(1, "Fix")) {
fat[boot->bpbRootClust].next = CLUST_FREE;
ret = FSFATMOD;
} else
ret = FSFATAL;
}
fat[boot->bpbRootClust].flags |= FAT_USED;
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(int f, struct bootblock *boot, struct fatEntry *fat, cl_t startcl,
int startoff, cl_t endcl, int endoff, int notlast)
{
u_char *s, *e;
off_t off;
int clsz = boot->bpbSecPerClust * boot->bpbBytesPerSec;
s = delbuf + startoff;
e = delbuf + clsz;
while (startcl >= CLUST_FIRST && startcl < boot->NumClusters) {
if (startcl == endcl) {
if (notlast)
break;
e = delbuf + endoff;
}
off = startcl * boot->bpbSecPerClust + boot->ClusterOffset;
off *= boot->bpbBytesPerSec;
if (lseek(f, off, SEEK_SET) != off
|| read(f, delbuf, clsz) != clsz) {
perr("Unable to read directory");
return FSFATAL;
}
while (s < e) {
*s = SLOT_DELETED;
s += 32;
}
if (lseek(f, off, SEEK_SET) != off
|| write(f, delbuf, clsz) != clsz) {
perr("Unable to write directory");
return FSFATAL;
}
if (startcl == endcl)
break;
startcl = fat[startcl].next;
s = delbuf;
}
return FSOK;
}
static int
removede(int f, struct bootblock *boot, struct fatEntry *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(f, boot, 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 bootblock *boot, struct fatEntry *fat, u_char *p,
struct dosDirEntry *dir)
{
/*
* Check size on ordinary files
*/
u_int32_t physicalSize;
if (dir->head == CLUST_FREE)
physicalSize = 0;
else {
if (dir->head < CLUST_FIRST || dir->head >= boot->NumClusters)
return FSERROR;
physicalSize = fat[dir->head].length * boot->ClusterSize;
}
if (physicalSize < dir->size) {
pwarn("size of %s is %u, should at most be %u\n",
fullpath(dir), dir->size, 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[cl].next;
clearchain(boot, fat, fat[cl].next);
fat[cl].next = CLUST_EOF;
fat[dir->head].length = len;
return FSFATMOD;
} else
return FSERROR;
}
return FSOK;
}
/*
* 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(int f, struct bootblock *boot, struct fatEntry *fat,
struct dosDirEntry *dir)
{
struct dosDirEntry dirent, *d;
u_char *p, *vallfn, *invlfn, *empty;
off_t off;
int i, j, k, last;
cl_t cl, valcl = ~0, invcl = ~0, empcl = ~0;
char *t;
u_int lidx = 0;
int shortSum;
int mod = FSOK;
#define THISMOD 0x8000 /* Only used within this routine */
cl = dir->head;
if (dir->parent && (cl < CLUST_FIRST || cl >= boot->NumClusters)) {
/*
* Already handled somewhere else.
*/
return FSOK;
}
shortSum = -1;
vallfn = invlfn = empty = NULL;
do {
if (!(boot->flags & FAT32) && !dir->parent) {
last = boot->bpbRootDirEnts * 32;
off = boot->bpbResSectors + boot->bpbFATs *
boot->FATsecs;
} else {
last = boot->bpbSecPerClust * boot->bpbBytesPerSec;
off = cl * boot->bpbSecPerClust + boot->ClusterOffset;
}
off *= boot->bpbBytesPerSec;
if (lseek(f, off, SEEK_SET) != off
|| read(f, buffer, last) != last) {
perr("Unable to read directory");
return FSFATAL;
}
last /= 32;
/*
* Check `.' and `..' entries here? XXX
*/
for (p = buffer, i = 0; i < last; 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(f, boot, fat,
empcl, empty - buffer,
cl, p - buffer, 1) == FSFATAL)
return FSFATAL;
q = empcl == cl ? empty : buffer;
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;
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(f, boot, 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(f, boot, 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;
if (dirent.size == 0 && !(dirent.flags & ATTR_DIRECTORY)) {
if (dirent.head != 0) {
pwarn("%s has clusters, but size 0\n",
fullpath(&dirent));
if (ask(1, "Drop allocated clusters")) {
p[26] = p[27] = 0;
if (boot->ClustMask == CLUST32_MASK)
p[20] = p[21] = 0;
clearchain(boot, fat, dirent.head);
dirent.head = 0;
mod |= THISMOD|FSDIRMOD|FSFATMOD;
} else
mod |= FSERROR;
}
} else if (dirent.head == 0
&& !strcmp(dirent.name, "..")
&& dir->parent /* XXX */
&& !dir->parent->parent) {
/*
* Do nothing, the parent is the root
*/
} else if (dirent.head < CLUST_FIRST
|| dirent.head >= boot->NumClusters
|| fat[dirent.head].next == CLUST_FREE
|| (fat[dirent.head].next >= CLUST_RSRVD
&& fat[dirent.head].next < CLUST_EOFS)
|| fat[dirent.head].head != dirent.head) {
if (dirent.head == 0)
pwarn("%s has no clusters\n",
fullpath(&dirent));
else if (dirent.head < CLUST_FIRST
|| dirent.head >= boot->NumClusters)
pwarn("%s starts with cluster out of range(%u)\n",
fullpath(&dirent),
dirent.head);
else if (fat[dirent.head].next == CLUST_FREE)
pwarn("%s starts with free cluster\n",
fullpath(&dirent));
else if (fat[dirent.head].next >= CLUST_RSRVD)
pwarn("%s starts with cluster marked %s\n",
fullpath(&dirent),
rsrvdcltype(fat[dirent.head].next));
else
pwarn("%s doesn't start a 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;
mod |= THISMOD|FSDIRMOD;
} else
mod |= FSERROR;
}
}
if (dirent.head >= CLUST_FIRST && dirent.head < boot->NumClusters)
fat[dirent.head].flags |= FAT_USED;
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;
}
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;
}
/* 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 {
mod |= k = checksize(boot, fat, p, &dirent);
if (k & FSDIRMOD)
mod |= THISMOD;
}
boot->NumFiles++;
}
if (!(boot->flags & FAT32) && !dir->parent)
break;
if (mod & THISMOD) {
last *= 32;
if (lseek(f, off, SEEK_SET) != off
|| write(f, buffer, last) != last) {
perr("Unable to write directory");
return FSFATAL;
}
mod &= ~THISMOD;
}
} while ((cl = fat[cl].next) >= CLUST_FIRST && cl < boot->NumClusters);
if (invlfn || vallfn)
mod |= removede(f, boot, 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 without being written out.
*/
if ((mod & FSDIRMOD) && !(boot->flags & FAT32) && !dir->parent) {
last *= 32;
if (lseek(f, off, SEEK_SET) != off
|| write(f, buffer, last) != last) {
perr("Unable to write directory");
return FSFATAL;
}
mod &= ~THISMOD;
}
return mod & ~THISMOD;
}
int
handleDirTree(int dosfs, struct bootblock *boot, struct fatEntry *fat)
{
int mod;
mod = readDosDirSection(dosfs, boot, 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(dosfs, boot, 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(int dosfs, struct bootblock *boot, struct fatEntry *fat, cl_t head)
{
struct dosDirEntry d;
int len;
u_char *p;
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[lfcl].next : lostDir->head;
if (lfcl < CLUST_FIRST || lfcl >= boot->NumClusters) {
/* Extend LOSTDIR? XXX */
pwarn("No space in %s\n", LOSTDIR);
return FSERROR;
}
lfoff = lfcl * boot->ClusterSize
+ boot->ClusterOffset * 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 = fat[head].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);
fat[head].flags |= FAT_USED;
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;
}