HardenedBSD/lib/libufs/libufs.h
Kirk McKusick 8f829a5cf0 Continuing efforts to provide hardening of FFS. This change adds a
check hash to the filesystem inodes. Access attempts to files
associated with an inode with an invalid check hash will fail with
EINVAL (Invalid argument). Access is reestablished after an fsck
is run to find and validate the inodes with invalid check-hashes.
This check avoids a class of filesystem panics related to corrupted
inodes. The hash is done using crc32c.

Note this check-hash is for the inode itself and not any of its
indirect blocks. Check-hash validation may be extended to also
cover indirect block pointers, but that will be a separate (and
more costly) feature.

Check hashes are added only to UFS2 and not to UFS1 as UFS1 is
primarily used in embedded systems with small memories and low-powered
processors which need as light-weight a filesystem as possible.

Reviewed by:  kib
Tested by:    Peter Holm
Sponsored by: Netflix
2018-12-11 22:14:37 +00:00

179 lines
5.1 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2002 Juli Mallett. All rights reserved.
*
* This software was written by Juli Mallett <jmallett@FreeBSD.org> for the
* FreeBSD project. Redistribution and use in source and binary forms, with
* or without modification, are permitted provided that the following
* conditions are met:
*
* 1. Redistribution of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistribution 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 ``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 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.
*
* $FreeBSD$
*/
#ifndef __LIBUFS_H__
#define __LIBUFS_H__
/*
* libufs structures.
*/
union dinodep {
struct ufs1_dinode *dp1;
struct ufs2_dinode *dp2;
};
/*
* userland ufs disk.
*/
struct uufsd {
const char *d_name; /* disk name */
int d_ufs; /* decimal UFS version */
int d_fd; /* raw device file descriptor */
long d_bsize; /* device bsize */
ufs2_daddr_t d_sblock; /* superblock location */
struct csum *d_sbcsum; /* Superblock summary info */
caddr_t d_inoblock; /* inode block */
uint32_t d_inomin; /* low inode (not ino_t for ABI compat) */
uint32_t d_inomax; /* high inode (not ino_t for ABI compat) */
union dinodep d_dp; /* pointer to currently active inode */
union {
struct fs d_fs; /* filesystem information */
char d_sb[MAXBSIZE];
/* superblock as buffer */
} d_sbunion;
union {
struct cg d_cg; /* cylinder group */
char d_buf[MAXBSIZE];
/* cylinder group storage */
} d_cgunion;
int d_ccg; /* current cylinder group */
int d_lcg; /* last cylinder group (in d_cg) */
const char *d_error; /* human readable disk error */
int d_mine; /* internal flags */
#define d_fs d_sbunion.d_fs
#define d_sb d_sbunion.d_sb
#define d_cg d_cgunion.d_cg
};
/*
* libufs macros (internal, non-exported).
*/
#ifdef _LIBUFS
/*
* Trace steps through libufs, to be used at entry and erroneous return.
*/
static inline void
ERROR(struct uufsd *u, const char *str)
{
#ifdef _LIBUFS_DEBUGGING
if (str != NULL) {
fprintf(stderr, "libufs: %s", str);
if (errno != 0)
fprintf(stderr, ": %s", strerror(errno));
fprintf(stderr, "\n");
}
#endif
if (u != NULL)
u->d_error = str;
}
#endif /* _LIBUFS */
__BEGIN_DECLS
/*
* libufs prototypes.
*/
/*
* ffs_subr.c
*/
void ffs_clrblock(struct fs *, u_char *, ufs1_daddr_t);
void ffs_clusteracct(struct fs *, struct cg *, ufs1_daddr_t, int);
void ffs_fragacct(struct fs *, int, int32_t [], int);
int ffs_isblock(struct fs *, u_char *, ufs1_daddr_t);
int ffs_isfreeblock(struct fs *, u_char *, ufs1_daddr_t);
void ffs_setblock(struct fs *, u_char *, ufs1_daddr_t);
int ffs_sbget(void *, struct fs **, off_t, char *,
int (*)(void *, off_t, void **, int));
int ffs_sbput(void *, struct fs *, off_t,
int (*)(void *, off_t, void *, int));
void ffs_update_dinode_ckhash(struct fs *, struct ufs2_dinode *);
int ffs_verify_dinode_ckhash(struct fs *, struct ufs2_dinode *);
/*
* Request standard superblock location in ffs_sbget
*/
#define STDSB -1 /* Fail if check-hash is bad */
#define STDSB_NOHASHFAIL -2 /* Ignore check-hash failure */
/*
* block.c
*/
ssize_t bread(struct uufsd *, ufs2_daddr_t, void *, size_t);
ssize_t bwrite(struct uufsd *, ufs2_daddr_t, const void *, size_t);
int berase(struct uufsd *, ufs2_daddr_t, ufs2_daddr_t);
/*
* cgroup.c
*/
ufs2_daddr_t cgballoc(struct uufsd *);
int cgbfree(struct uufsd *, ufs2_daddr_t, long);
ino_t cgialloc(struct uufsd *);
int cgget(struct uufsd *, int, struct cg *);
int cgput(struct uufsd *, struct cg *);
int cgread(struct uufsd *);
int cgread1(struct uufsd *, int);
int cgwrite(struct uufsd *);
int cgwrite1(struct uufsd *, int);
/*
* inode.c
*/
int getinode(struct uufsd *, union dinodep *, ino_t);
int putinode(struct uufsd *);
/*
* sblock.c
*/
int sbread(struct uufsd *);
int sbwrite(struct uufsd *, int);
/* low level superblock read/write functions */
int sbget(int, struct fs **, off_t);
int sbput(int, struct fs *, int);
/*
* type.c
*/
int ufs_disk_close(struct uufsd *);
int ufs_disk_fillout(struct uufsd *, const char *);
int ufs_disk_fillout_blank(struct uufsd *, const char *);
int ufs_disk_write(struct uufsd *);
/*
* crc32c.c
*/
uint32_t calculate_crc32c(uint32_t, const void *, size_t);
__END_DECLS
#endif /* __LIBUFS_H__ */