linux/include/net/cipso_ipv4.h
Paul Moore 389fb800ac netlabel: Label incoming TCP connections correctly in SELinux
The current NetLabel/SELinux behavior for incoming TCP connections works but
only through a series of happy coincidences that rely on the limited nature of
standard CIPSO (only able to convey MLS attributes) and the write equality
imposed by the SELinux MLS constraints.  The problem is that network sockets
created as the result of an incoming TCP connection were not on-the-wire
labeled based on the security attributes of the parent socket but rather based
on the wire label of the remote peer.  The issue had to do with how IP options
were managed as part of the network stack and where the LSM hooks were in
relation to the code which set the IP options on these newly created child
sockets.  While NetLabel/SELinux did correctly set the socket's on-the-wire
label it was promptly cleared by the network stack and reset based on the IP
options of the remote peer.

This patch, in conjunction with a prior patch that adjusted the LSM hook
locations, works to set the correct on-the-wire label format for new incoming
connections through the security_inet_conn_request() hook.  Besides the
correct behavior there are many advantages to this change, the most significant
is that all of the NetLabel socket labeling code in SELinux now lives in hooks
which can return error codes to the core stack which allows us to finally get
ride of the selinux_netlbl_inode_permission() logic which greatly simplfies
the NetLabel/SELinux glue code.  In the process of developing this patch I
also ran into a small handful of AF_INET6 cleanliness issues that have been
fixed which should make the code safer and easier to extend in the future.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-03-28 15:01:36 +11:00

293 lines
7.4 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 <net/request_sock.h>
#include <asm/atomic.h>
/* known doi values */
#define CIPSO_V4_DOI_UNKNOWN 0x00000000
/* standard 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
/* non-standard tag types (tags > 127) */
#define CIPSO_V4_TAG_LOCAL 128
/* doi mapping types */
#define CIPSO_V4_MAP_UNKNOWN 0
#define CIPSO_V4_MAP_TRANS 1
#define CIPSO_V4_MAP_PASS 2
#define CIPSO_V4_MAP_LOCAL 3
/* 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,
struct netlbl_audit *audit_info);
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,
struct netlbl_audit *audit_info)
{
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);
void cipso_v4_sock_delattr(struct sock *sk);
int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr);
int cipso_v4_req_setattr(struct request_sock *req,
const struct cipso_v4_doi *doi_def,
const struct netlbl_lsm_secattr *secattr);
void cipso_v4_req_delattr(struct request_sock *req);
int cipso_v4_skbuff_setattr(struct sk_buff *skb,
const struct cipso_v4_doi *doi_def,
const struct netlbl_lsm_secattr *secattr);
int cipso_v4_skbuff_delattr(struct sk_buff *skb);
int cipso_v4_skbuff_getattr(const struct sk_buff *skb,
struct netlbl_lsm_secattr *secattr);
int cipso_v4_validate(const struct sk_buff *skb, 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 void cipso_v4_sock_delattr(struct sock *sk)
{
}
static inline int cipso_v4_sock_getattr(struct sock *sk,
struct netlbl_lsm_secattr *secattr)
{
return -ENOSYS;
}
static inline int cipso_v4_req_setattr(struct request_sock *req,
const struct cipso_v4_doi *doi_def,
const struct netlbl_lsm_secattr *secattr)
{
return -ENOSYS;
}
static inline void cipso_v4_req_delattr(struct request_sock *req)
{
return;
}
static inline int cipso_v4_skbuff_setattr(struct sk_buff *skb,
const struct cipso_v4_doi *doi_def,
const struct netlbl_lsm_secattr *secattr)
{
return -ENOSYS;
}
static inline int cipso_v4_skbuff_delattr(struct sk_buff *skb)
{
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(const struct sk_buff *skb,
unsigned char **option)
{
return -ENOSYS;
}
#endif /* CONFIG_NETLABEL */
#endif /* _CIPSO_IPV4_H */