freebsd-dev/lib/libgeom/libgeom.h
Juli Mallett 3dce589cb9 Fix 32-bit libgeom consumers run on 64-bit kernels with COMPAT_FREEBSD32.
Kernel pointer values are used as opaque unique identifiers, which are then
used to reconstruct references between various providers, classes, etc., inside
libgeom from the source XML.  Unfortunately, they're converted to pointer-width
integers (in the form of pointers) to do this, and 32-bit userland pointers
cannot hold sensible representations (however opaque) of 64-bit kernel pointers
on all systems.

In the case where the leading bits are zero and 32 distinct bits of pointer can
be identified, this will happen to work.  On systems where the upper 32-bits of
kernel pointers are non-zero and the same for all kernel pointers, this will
result in double frees and all kinds of bizarre crashes and linkage between
objects inside libgeom.

To mitigate this problem, treat the opaque identifiers in the XML as C strings
instead, and internalize them to give unique and consistent per-object pointer
values in userland for each identifier in the XML.  This allows us to keep the
libgeom logic the same with only minor changes to initial setup and parsing.

It might be more sensible for speed reasons to treat the identifiers as numbers
of a large size (uintmax_t, say) rather than strings, but strings seem fine for
now.

(As an added side-effect, this makes it slightly easier to identify unresolved
 references, but nothing has been added to inform the user of those.)
2012-03-29 03:13:43 +00:00

168 lines
4.4 KiB
C

/*-
* Copyright (c) 2003 Poul-Henning Kamp
* All rights reserved.
*
* 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.
* 3. The names of the authors may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* 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.
*
* $FreeBSD$
*/
#ifndef _LIBGEOM_H_
#define _LIBGEOM_H_
#include <sys/cdefs.h>
#include <sys/queue.h>
#include <sys/time.h>
#include <geom/geom_ctl.h>
__BEGIN_DECLS
void geom_stats_close(void);
void geom_stats_resync(void);
int geom_stats_open(void);
void *geom_stats_snapshot_get(void);
void geom_stats_snapshot_free(void *);
void geom_stats_snapshot_timestamp(void *, struct timespec *);
void geom_stats_snapshot_reset(void *);
struct devstat *geom_stats_snapshot_next(void *);
char *geom_getxml(void);
/* geom_xml2tree.c */
/*
* These structs are used to build the tree based on the XML.
* they're named as the kernel variant without the first '_'.
*/
struct gclass;
struct ggeom;
struct gconsumer;
struct gprovider;
LIST_HEAD(gconf, gconfig);
struct gident {
void *lg_id;
void *lg_ptr;
enum { ISCLASS,
ISGEOM,
ISPROVIDER,
ISCONSUMER,
ISUNRESOLVED } lg_what;
};
struct gmesh {
LIST_HEAD(, gclass) lg_class;
struct gident *lg_ident;
};
struct gconfig {
LIST_ENTRY(gconfig) lg_config;
char *lg_name;
char *lg_val;
};
struct gclass {
void *lg_id;
char *lg_name;
LIST_ENTRY(gclass) lg_class;
LIST_HEAD(, ggeom) lg_geom;
struct gconf lg_config;
};
struct ggeom {
void *lg_id;
struct gclass *lg_class;
char *lg_name;
u_int lg_rank;
LIST_ENTRY(ggeom) lg_geom;
LIST_HEAD(, gconsumer) lg_consumer;
LIST_HEAD(, gprovider) lg_provider;
struct gconf lg_config;
};
struct gconsumer {
void *lg_id;
struct ggeom *lg_geom;
LIST_ENTRY(gconsumer) lg_consumer;
struct gprovider *lg_provider;
LIST_ENTRY(gconsumer) lg_consumers;
char *lg_mode;
struct gconf lg_config;
};
struct gprovider {
void *lg_id;
char *lg_name;
struct ggeom *lg_geom;
LIST_ENTRY(gprovider) lg_provider;
LIST_HEAD(, gconsumer) lg_consumers;
char *lg_mode;
off_t lg_mediasize;
u_int lg_sectorsize;
off_t lg_stripeoffset;
off_t lg_stripesize;
struct gconf lg_config;
};
struct gident * geom_lookupid(struct gmesh *, const void *);
int geom_xml2tree(struct gmesh *, char *);
int geom_gettree(struct gmesh *);
void geom_deletetree(struct gmesh *);
/* geom_ctl.c */
struct gctl_req;
#ifdef _STDIO_H_ /* limit #include pollution */
void gctl_dump(struct gctl_req *, FILE *);
#endif
void gctl_free(struct gctl_req *);
struct gctl_req *gctl_get_handle(void);
const char *gctl_issue(struct gctl_req *);
void gctl_ro_param(struct gctl_req *, const char *, int, const void *);
void gctl_rw_param(struct gctl_req *, const char *, int, void *);
/* geom_util.c */
int g_open(const char *, int);
int g_close(int);
off_t g_mediasize(int);
ssize_t g_sectorsize(int);
off_t g_stripeoffset(int);
off_t g_stripesize(int);
int g_flush(int);
int g_delete(int, off_t, off_t);
int g_get_ident(int, char *, size_t);
int g_get_name(const char *, char *, size_t);
int g_open_by_ident(const char *, int, char *, size_t);
char *g_device_path(const char *);
char *g_providername(int);
__END_DECLS
#endif /* _LIBGEOM_H_ */