freebsd-dev/stand/libsa/ufsread.c
2017-11-14 23:02:19 +00:00

327 lines
8.7 KiB
C

/*-
* Copyright (c) 2002 McAfee, Inc.
* All rights reserved.
*
* This software was developed for the FreeBSD Project by Marshall
* Kirk McKusick and McAfee Research,, the Security Research Division of
* McAfee, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as
* part of the DARPA CHATS research program
*
* 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 AUTHOR AND CONTRIBUTORS ``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 AUTHOR OR CONTRIBUTORS 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.
*/
/*-
* Copyright (c) 1998 Robert Nordier
* All rights reserved.
*
* Redistribution and use in source and binary forms are freely
* permitted provided that the above copyright notice and this
* paragraph and the following disclaimer are duplicated in all
* such forms.
*
* This software is provided "AS IS" and without any express or
* implied warranties, including, without limitation, the implied
* warranties of merchantability and fitness for a particular
* purpose.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <ufs/ufs/dinode.h>
#include <ufs/ufs/dir.h>
#include <ufs/ffs/fs.h>
#ifdef UFS_SMALL_CGBASE
/* XXX: Revert to old (broken for over 1.5Tb filesystems) version of cgbase
(see sys/ufs/ffs/fs.h rev 1.39) so that small boot loaders (e.g. boot2) can
support both UFS1 and UFS2. */
#undef cgbase
#define cgbase(fs, c) ((ufs2_daddr_t)((fs)->fs_fpg * (c)))
#endif
typedef uint32_t ufs_ino_t;
/*
* We use 4k `virtual' blocks for filesystem data, whatever the actual
* filesystem block size. FFS blocks are always a multiple of 4k.
*/
#define VBLKSHIFT 12
#define VBLKSIZE (1 << VBLKSHIFT)
#define VBLKMASK (VBLKSIZE - 1)
#define DBPERVBLK (VBLKSIZE / DEV_BSIZE)
#define INDIRPERVBLK(fs) (NINDIR(fs) / ((fs)->fs_bsize >> VBLKSHIFT))
#define IPERVBLK(fs) (INOPB(fs) / ((fs)->fs_bsize >> VBLKSHIFT))
#define INO_TO_VBA(fs, ipervblk, x) \
(fsbtodb(fs, cgimin(fs, ino_to_cg(fs, x))) + \
(((x) % (fs)->fs_ipg) / (ipervblk) * DBPERVBLK))
#define INO_TO_VBO(ipervblk, x) ((x) % ipervblk)
#define FS_TO_VBA(fs, fsb, off) (fsbtodb(fs, fsb) + \
((off) / VBLKSIZE) * DBPERVBLK)
#define FS_TO_VBO(fs, fsb, off) ((off) & VBLKMASK)
/* Buffers that must not span a 64k boundary. */
struct dmadat {
char blkbuf[VBLKSIZE]; /* filesystem blocks */
char indbuf[VBLKSIZE]; /* indir blocks */
char sbbuf[SBLOCKSIZE]; /* superblock */
char secbuf[DEV_BSIZE]; /* for MBR/disklabel */
};
static struct dmadat *dmadat;
static ufs_ino_t lookup(const char *);
static ssize_t fsread(ufs_ino_t, void *, size_t);
static uint8_t ls, dsk_meta;
static uint32_t fs_off;
static __inline uint8_t
fsfind(const char *name, ufs_ino_t * ino)
{
static char buf[DEV_BSIZE];
static struct direct d;
char *s;
ssize_t n;
fs_off = 0;
while ((n = fsread(*ino, buf, DEV_BSIZE)) > 0)
for (s = buf; s < buf + DEV_BSIZE;) {
memcpy(&d, s, sizeof(struct direct));
if (ls)
printf("%s ", d.d_name);
else if (!strcmp(name, d.d_name)) {
*ino = d.d_ino;
return d.d_type;
}
s += d.d_reclen;
}
if (n != -1 && ls)
printf("\n");
return 0;
}
static ufs_ino_t
lookup(const char *path)
{
static char name[UFS_MAXNAMLEN + 1];
const char *s;
ufs_ino_t ino;
ssize_t n;
uint8_t dt;
ino = UFS_ROOTINO;
dt = DT_DIR;
for (;;) {
if (*path == '/')
path++;
if (!*path)
break;
for (s = path; *s && *s != '/'; s++);
if ((n = s - path) > UFS_MAXNAMLEN)
return 0;
ls = *path == '?' && n == 1 && !*s;
memcpy(name, path, n);
name[n] = 0;
if (dt != DT_DIR) {
printf("%s: not a directory.\n", name);
return (0);
}
if ((dt = fsfind(name, &ino)) <= 0)
break;
path = s;
}
return dt == DT_REG ? ino : 0;
}
/*
* Possible superblock locations ordered from most to least likely.
*/
static int sblock_try[] = SBLOCKSEARCH;
#if defined(UFS2_ONLY)
#define DIP(field) dp2.field
#elif defined(UFS1_ONLY)
#define DIP(field) dp1.field
#else
#define DIP(field) fs.fs_magic == FS_UFS1_MAGIC ? dp1.field : dp2.field
#endif
static ssize_t
fsread_size(ufs_ino_t inode, void *buf, size_t nbyte, size_t *fsizep)
{
#ifndef UFS2_ONLY
static struct ufs1_dinode dp1;
ufs1_daddr_t addr1;
#endif
#ifndef UFS1_ONLY
static struct ufs2_dinode dp2;
#endif
static struct fs fs;
static ufs_ino_t inomap;
char *blkbuf;
void *indbuf;
char *s;
size_t n, nb, size, off, vboff;
ufs_lbn_t lbn;
ufs2_daddr_t addr2, vbaddr;
static ufs2_daddr_t blkmap, indmap;
u_int u;
/* Basic parameter validation. */
if ((buf == NULL && nbyte != 0) || dmadat == NULL)
return (-1);
blkbuf = dmadat->blkbuf;
indbuf = dmadat->indbuf;
/*
* Force probe if inode is zero to ensure we have a valid fs, otherwise
* when probing multiple paritions, reads from subsequent parititions
* will incorrectly succeed.
*/
if (!dsk_meta || inode == 0) {
inomap = 0;
dsk_meta = 0;
for (n = 0; sblock_try[n] != -1; n++) {
if (dskread(dmadat->sbbuf, sblock_try[n] / DEV_BSIZE,
SBLOCKSIZE / DEV_BSIZE))
return -1;
memcpy(&fs, dmadat->sbbuf, sizeof(struct fs));
if ((
#if defined(UFS1_ONLY)
fs.fs_magic == FS_UFS1_MAGIC
#elif defined(UFS2_ONLY)
(fs.fs_magic == FS_UFS2_MAGIC &&
fs.fs_sblockloc == sblock_try[n])
#else
fs.fs_magic == FS_UFS1_MAGIC ||
(fs.fs_magic == FS_UFS2_MAGIC &&
fs.fs_sblockloc == sblock_try[n])
#endif
) &&
fs.fs_bsize <= MAXBSIZE &&
fs.fs_bsize >= (int32_t)sizeof(struct fs))
break;
}
if (sblock_try[n] == -1) {
return -1;
}
dsk_meta++;
} else
memcpy(&fs, dmadat->sbbuf, sizeof(struct fs));
if (!inode)
return 0;
if (inomap != inode) {
n = IPERVBLK(&fs);
if (dskread(blkbuf, INO_TO_VBA(&fs, n, inode), DBPERVBLK))
return -1;
n = INO_TO_VBO(n, inode);
#if defined(UFS1_ONLY)
memcpy(&dp1, (struct ufs1_dinode *)(void *)blkbuf + n,
sizeof(dp1));
#elif defined(UFS2_ONLY)
memcpy(&dp2, (struct ufs2_dinode *)(void *)blkbuf + n,
sizeof(dp2));
#else
if (fs.fs_magic == FS_UFS1_MAGIC)
memcpy(&dp1, (struct ufs1_dinode *)(void *)blkbuf + n,
sizeof(dp1));
else
memcpy(&dp2, (struct ufs2_dinode *)(void *)blkbuf + n,
sizeof(dp2));
#endif
inomap = inode;
fs_off = 0;
blkmap = indmap = 0;
}
s = buf;
size = DIP(di_size);
n = size - fs_off;
if (nbyte > n)
nbyte = n;
nb = nbyte;
while (nb) {
lbn = lblkno(&fs, fs_off);
off = blkoff(&fs, fs_off);
if (lbn < UFS_NDADDR) {
addr2 = DIP(di_db[lbn]);
} else if (lbn < UFS_NDADDR + NINDIR(&fs)) {
n = INDIRPERVBLK(&fs);
addr2 = DIP(di_ib[0]);
u = (u_int)(lbn - UFS_NDADDR) / n * DBPERVBLK;
vbaddr = fsbtodb(&fs, addr2) + u;
if (indmap != vbaddr) {
if (dskread(indbuf, vbaddr, DBPERVBLK))
return -1;
indmap = vbaddr;
}
n = (lbn - UFS_NDADDR) & (n - 1);
#if defined(UFS1_ONLY)
memcpy(&addr1, (ufs1_daddr_t *)indbuf + n,
sizeof(ufs1_daddr_t));
addr2 = addr1;
#elif defined(UFS2_ONLY)
memcpy(&addr2, (ufs2_daddr_t *)indbuf + n,
sizeof(ufs2_daddr_t));
#else
if (fs.fs_magic == FS_UFS1_MAGIC) {
memcpy(&addr1, (ufs1_daddr_t *)indbuf + n,
sizeof(ufs1_daddr_t));
addr2 = addr1;
} else
memcpy(&addr2, (ufs2_daddr_t *)indbuf + n,
sizeof(ufs2_daddr_t));
#endif
} else
return -1;
vbaddr = fsbtodb(&fs, addr2) + (off >> VBLKSHIFT) * DBPERVBLK;
vboff = off & VBLKMASK;
n = sblksize(&fs, (off_t)size, lbn) - (off & ~VBLKMASK);
if (n > VBLKSIZE)
n = VBLKSIZE;
if (blkmap != vbaddr) {
if (dskread(blkbuf, vbaddr, n >> DEV_BSHIFT))
return -1;
blkmap = vbaddr;
}
n -= vboff;
if (n > nb)
n = nb;
memcpy(s, blkbuf + vboff, n);
s += n;
fs_off += n;
nb -= n;
}
if (fsizep != NULL)
*fsizep = size;
return nbyte;
}
static ssize_t
fsread(ufs_ino_t inode, void *buf, size_t nbyte)
{
return fsread_size(inode, buf, nbyte, NULL);
}