Paul Moore b1edeb1023 netlabel: Replace protocol/NetLabel linking with refrerence counts
NetLabel has always had a list of backpointers in the CIPSO DOI definition
structure which pointed to the NetLabel LSM domain mapping structures which
referenced the CIPSO DOI struct.  The rationale for this was that when an
administrator removed a CIPSO DOI from the system all of the associated
NetLabel LSM domain mappings should be removed as well; a list of
backpointers made this a simple operation.

Unfortunately, while the backpointers did make the removal easier they were
a bit of a mess from an implementation point of view which was making
further development difficult.  Since the removal of a CIPSO DOI is a
realtively rare event it seems to make sense to remove this backpointer
list as the optimization was hurting us more then it was helping.  However,
we still need to be able to track when a CIPSO DOI definition is being used
so replace the backpointer list with a reference count.  In order to
preserve the current functionality of removing the associated LSM domain
mappings when a CIPSO DOI is removed we walk the LSM domain mapping table,
removing the relevant entries.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Reviewed-by: James Morris <jmorris@namei.org>
2008-10-10 10:16:31 -04:00

248 lines
6.1 KiB
C

/*
* CIPSO - Commercial IP Security Option
*
* This is an implementation of the CIPSO 2.2 protocol as specified in
* draft-ietf-cipso-ipsecurity-01.txt with additional tag types as found in
* FIPS-188, copies of both documents can be found in the Documentation
* directory. While CIPSO never became a full IETF RFC standard many vendors
* have chosen to adopt the protocol and over the years it has become a
* de-facto standard for labeled networking.
*
* Author: Paul Moore <paul.moore@hp.com>
*
*/
/*
* (c) Copyright Hewlett-Packard Development Company, L.P., 2006
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
* the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#ifndef _CIPSO_IPV4_H
#define _CIPSO_IPV4_H
#include <linux/types.h>
#include <linux/rcupdate.h>
#include <linux/list.h>
#include <linux/net.h>
#include <linux/skbuff.h>
#include <net/netlabel.h>
#include <asm/atomic.h>
/* known doi values */
#define CIPSO_V4_DOI_UNKNOWN 0x00000000
/* tag types */
#define CIPSO_V4_TAG_INVALID 0
#define CIPSO_V4_TAG_RBITMAP 1
#define CIPSO_V4_TAG_ENUM 2
#define CIPSO_V4_TAG_RANGE 5
#define CIPSO_V4_TAG_PBITMAP 6
#define CIPSO_V4_TAG_FREEFORM 7
/* doi mapping types */
#define CIPSO_V4_MAP_UNKNOWN 0
#define CIPSO_V4_MAP_STD 1
#define CIPSO_V4_MAP_PASS 2
/* limits */
#define CIPSO_V4_MAX_REM_LVLS 255
#define CIPSO_V4_INV_LVL 0x80000000
#define CIPSO_V4_MAX_LOC_LVLS (CIPSO_V4_INV_LVL - 1)
#define CIPSO_V4_MAX_REM_CATS 65534
#define CIPSO_V4_INV_CAT 0x80000000
#define CIPSO_V4_MAX_LOC_CATS (CIPSO_V4_INV_CAT - 1)
/*
* CIPSO DOI definitions
*/
/* DOI definition struct */
#define CIPSO_V4_TAG_MAXCNT 5
struct cipso_v4_doi {
u32 doi;
u32 type;
union {
struct cipso_v4_std_map_tbl *std;
} map;
u8 tags[CIPSO_V4_TAG_MAXCNT];
atomic_t refcount;
struct list_head list;
struct rcu_head rcu;
};
/* Standard CIPSO mapping table */
/* NOTE: the highest order bit (i.e. 0x80000000) is an 'invalid' flag, if the
* bit is set then consider that value as unspecified, meaning the
* mapping for that particular level/category is invalid */
struct cipso_v4_std_map_tbl {
struct {
u32 *cipso;
u32 *local;
u32 cipso_size;
u32 local_size;
} lvl;
struct {
u32 *cipso;
u32 *local;
u32 cipso_size;
u32 local_size;
} cat;
};
/*
* Sysctl Variables
*/
#ifdef CONFIG_NETLABEL
extern int cipso_v4_cache_enabled;
extern int cipso_v4_cache_bucketsize;
extern int cipso_v4_rbm_optfmt;
extern int cipso_v4_rbm_strictvalid;
#endif
/*
* Helper Functions
*/
#define CIPSO_V4_OPTEXIST(x) (IPCB(x)->opt.cipso != 0)
#define CIPSO_V4_OPTPTR(x) (skb_network_header(x) + IPCB(x)->opt.cipso)
/*
* DOI List Functions
*/
#ifdef CONFIG_NETLABEL
int cipso_v4_doi_add(struct cipso_v4_doi *doi_def);
void cipso_v4_doi_free(struct cipso_v4_doi *doi_def);
int cipso_v4_doi_remove(u32 doi, struct netlbl_audit *audit_info);
struct cipso_v4_doi *cipso_v4_doi_getdef(u32 doi);
void cipso_v4_doi_putdef(struct cipso_v4_doi *doi_def);
int cipso_v4_doi_walk(u32 *skip_cnt,
int (*callback) (struct cipso_v4_doi *doi_def, void *arg),
void *cb_arg);
#else
static inline int cipso_v4_doi_add(struct cipso_v4_doi *doi_def)
{
return -ENOSYS;
}
static inline void cipso_v4_doi_free(struct cipso_v4_doi *doi_def)
{
return;
}
static inline int cipso_v4_doi_remove(u32 doi,
struct netlbl_audit *audit_info)
{
return 0;
}
static inline struct cipso_v4_doi *cipso_v4_doi_getdef(u32 doi)
{
return NULL;
}
static inline int cipso_v4_doi_walk(u32 *skip_cnt,
int (*callback) (struct cipso_v4_doi *doi_def, void *arg),
void *cb_arg)
{
return 0;
}
static inline int cipso_v4_doi_domhsh_add(struct cipso_v4_doi *doi_def,
const char *domain)
{
return -ENOSYS;
}
static inline int cipso_v4_doi_domhsh_remove(struct cipso_v4_doi *doi_def,
const char *domain)
{
return 0;
}
#endif /* CONFIG_NETLABEL */
/*
* Label Mapping Cache Functions
*/
#ifdef CONFIG_NETLABEL
void cipso_v4_cache_invalidate(void);
int cipso_v4_cache_add(const struct sk_buff *skb,
const struct netlbl_lsm_secattr *secattr);
#else
static inline void cipso_v4_cache_invalidate(void)
{
return;
}
static inline int cipso_v4_cache_add(const struct sk_buff *skb,
const struct netlbl_lsm_secattr *secattr)
{
return 0;
}
#endif /* CONFIG_NETLABEL */
/*
* Protocol Handling Functions
*/
#ifdef CONFIG_NETLABEL
void cipso_v4_error(struct sk_buff *skb, int error, u32 gateway);
int cipso_v4_sock_setattr(struct sock *sk,
const struct cipso_v4_doi *doi_def,
const struct netlbl_lsm_secattr *secattr);
int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr);
int cipso_v4_skbuff_getattr(const struct sk_buff *skb,
struct netlbl_lsm_secattr *secattr);
int cipso_v4_validate(unsigned char **option);
#else
static inline void cipso_v4_error(struct sk_buff *skb,
int error,
u32 gateway)
{
return;
}
static inline int cipso_v4_sock_setattr(struct sock *sk,
const struct cipso_v4_doi *doi_def,
const struct netlbl_lsm_secattr *secattr)
{
return -ENOSYS;
}
static inline int cipso_v4_sock_getattr(struct sock *sk,
struct netlbl_lsm_secattr *secattr)
{
return -ENOSYS;
}
static inline int cipso_v4_skbuff_getattr(const struct sk_buff *skb,
struct netlbl_lsm_secattr *secattr)
{
return -ENOSYS;
}
static inline int cipso_v4_validate(unsigned char **option)
{
return -ENOSYS;
}
#endif /* CONFIG_NETLABEL */
#endif /* _CIPSO_IPV4_H */