linux/include/net/netlabel.h
Paul Moore 23bcdc1ade SELinux: enable dynamic activation/deactivation of NetLabel/SELinux enforcement
Create a new NetLabel KAPI interface, netlbl_enabled(), which reports on the
current runtime status of NetLabel based on the existing configuration.  LSMs
that make use of NetLabel, i.e. SELinux, can use this new function to determine
if they should perform NetLabel access checks.  This patch changes the
NetLabel/SELinux glue code such that SELinux only enforces NetLabel related
access checks when netlbl_enabled() returns true.

At present NetLabel is considered to be enabled when there is at least one
labeled protocol configuration present.  The result is that by default NetLabel
is considered to be disabled, however, as soon as an administrator configured
a CIPSO DOI definition NetLabel is enabled and SELinux starts enforcing
NetLabel related access controls - including unlabeled packet controls.

This patch also tries to consolidate the multiple "#ifdef CONFIG_NETLABEL"
blocks into a single block to ease future review as recommended by Linus.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
2007-07-19 10:21:11 -04:00

380 lines
11 KiB
C

/*
* NetLabel System
*
* The NetLabel system manages static and dynamic label mappings for network
* protocols such as CIPSO and RIPSO.
*
* 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 _NETLABEL_H
#define _NETLABEL_H
#include <linux/types.h>
#include <linux/net.h>
#include <linux/skbuff.h>
#include <net/netlink.h>
#include <asm/atomic.h>
/*
* NetLabel - A management interface for maintaining network packet label
* mapping tables for explicit packet labling protocols.
*
* Network protocols such as CIPSO and RIPSO require a label translation layer
* to convert the label on the packet into something meaningful on the host
* machine. In the current Linux implementation these mapping tables live
* inside the kernel; NetLabel provides a mechanism for user space applications
* to manage these mapping tables.
*
* NetLabel makes use of the Generic NETLINK mechanism as a transport layer to
* send messages between kernel and user space. The general format of a
* NetLabel message is shown below:
*
* +-----------------+-------------------+--------- --- -- -
* | struct nlmsghdr | struct genlmsghdr | payload
* +-----------------+-------------------+--------- --- -- -
*
* The 'nlmsghdr' and 'genlmsghdr' structs should be dealt with like normal.
* The payload is dependent on the subsystem specified in the
* 'nlmsghdr->nlmsg_type' and should be defined below, supporting functions
* should be defined in the corresponding net/netlabel/netlabel_<subsys>.h|c
* file. All of the fields in the NetLabel payload are NETLINK attributes, see
* the include/net/netlink.h file for more information on NETLINK attributes.
*
*/
/*
* NetLabel NETLINK protocol
*/
#define NETLBL_PROTO_VERSION 1
/* NetLabel NETLINK types/families */
#define NETLBL_NLTYPE_NONE 0
#define NETLBL_NLTYPE_MGMT 1
#define NETLBL_NLTYPE_MGMT_NAME "NLBL_MGMT"
#define NETLBL_NLTYPE_RIPSO 2
#define NETLBL_NLTYPE_RIPSO_NAME "NLBL_RIPSO"
#define NETLBL_NLTYPE_CIPSOV4 3
#define NETLBL_NLTYPE_CIPSOV4_NAME "NLBL_CIPSOv4"
#define NETLBL_NLTYPE_CIPSOV6 4
#define NETLBL_NLTYPE_CIPSOV6_NAME "NLBL_CIPSOv6"
#define NETLBL_NLTYPE_UNLABELED 5
#define NETLBL_NLTYPE_UNLABELED_NAME "NLBL_UNLBL"
/*
* NetLabel - Kernel API for accessing the network packet label mappings.
*
* The following functions are provided for use by other kernel modules,
* specifically kernel LSM modules, to provide a consistent, transparent API
* for dealing with explicit packet labeling protocols such as CIPSO and
* RIPSO. The functions defined here are implemented in the
* net/netlabel/netlabel_kapi.c file.
*
*/
/* NetLabel audit information */
struct netlbl_audit {
u32 secid;
uid_t loginuid;
};
/* Domain mapping definition struct */
struct netlbl_dom_map;
/* Domain mapping operations */
int netlbl_domhsh_remove(const char *domain, struct netlbl_audit *audit_info);
/* LSM security attributes */
struct netlbl_lsm_cache {
atomic_t refcount;
void (*free) (const void *data);
void *data;
};
/* The catmap bitmap field MUST be a power of two in length and large
* enough to hold at least 240 bits. Special care (i.e. check the code!)
* should be used when changing these values as the LSM implementation
* probably has functions which rely on the sizes of these types to speed
* processing. */
#define NETLBL_CATMAP_MAPTYPE u64
#define NETLBL_CATMAP_MAPCNT 4
#define NETLBL_CATMAP_MAPSIZE (sizeof(NETLBL_CATMAP_MAPTYPE) * 8)
#define NETLBL_CATMAP_SIZE (NETLBL_CATMAP_MAPSIZE * \
NETLBL_CATMAP_MAPCNT)
#define NETLBL_CATMAP_BIT (NETLBL_CATMAP_MAPTYPE)0x01
struct netlbl_lsm_secattr_catmap {
u32 startbit;
NETLBL_CATMAP_MAPTYPE bitmap[NETLBL_CATMAP_MAPCNT];
struct netlbl_lsm_secattr_catmap *next;
};
#define NETLBL_SECATTR_NONE 0x00000000
#define NETLBL_SECATTR_DOMAIN 0x00000001
#define NETLBL_SECATTR_CACHE 0x00000002
#define NETLBL_SECATTR_MLS_LVL 0x00000004
#define NETLBL_SECATTR_MLS_CAT 0x00000008
struct netlbl_lsm_secattr {
u32 flags;
char *domain;
u32 mls_lvl;
struct netlbl_lsm_secattr_catmap *mls_cat;
struct netlbl_lsm_cache *cache;
};
/*
* LSM security attribute operations (inline)
*/
/**
* netlbl_secattr_cache_alloc - Allocate and initialize a secattr cache
* @flags: the memory allocation flags
*
* Description:
* Allocate and initialize a netlbl_lsm_cache structure. Returns a pointer
* on success, NULL on failure.
*
*/
static inline struct netlbl_lsm_cache *netlbl_secattr_cache_alloc(gfp_t flags)
{
struct netlbl_lsm_cache *cache;
cache = kzalloc(sizeof(*cache), flags);
if (cache)
atomic_set(&cache->refcount, 1);
return cache;
}
/**
* netlbl_secattr_cache_free - Frees a netlbl_lsm_cache struct
* @cache: the struct to free
*
* Description:
* Frees @secattr including all of the internal buffers.
*
*/
static inline void netlbl_secattr_cache_free(struct netlbl_lsm_cache *cache)
{
if (!atomic_dec_and_test(&cache->refcount))
return;
if (cache->free)
cache->free(cache->data);
kfree(cache);
}
/**
* netlbl_secattr_catmap_alloc - Allocate a LSM secattr catmap
* @flags: memory allocation flags
*
* Description:
* Allocate memory for a LSM secattr catmap, returns a pointer on success, NULL
* on failure.
*
*/
static inline struct netlbl_lsm_secattr_catmap *netlbl_secattr_catmap_alloc(
gfp_t flags)
{
return kzalloc(sizeof(struct netlbl_lsm_secattr_catmap), flags);
}
/**
* netlbl_secattr_catmap_free - Free a LSM secattr catmap
* @catmap: the category bitmap
*
* Description:
* Free a LSM secattr catmap.
*
*/
static inline void netlbl_secattr_catmap_free(
struct netlbl_lsm_secattr_catmap *catmap)
{
struct netlbl_lsm_secattr_catmap *iter;
do {
iter = catmap;
catmap = catmap->next;
kfree(iter);
} while (catmap);
}
/**
* netlbl_secattr_init - Initialize a netlbl_lsm_secattr struct
* @secattr: the struct to initialize
*
* Description:
* Initialize an already allocated netlbl_lsm_secattr struct.
*
*/
static inline void netlbl_secattr_init(struct netlbl_lsm_secattr *secattr)
{
secattr->flags = 0;
secattr->domain = NULL;
secattr->mls_cat = NULL;
secattr->cache = NULL;
}
/**
* netlbl_secattr_destroy - Clears a netlbl_lsm_secattr struct
* @secattr: the struct to clear
*
* Description:
* Destroys the @secattr struct, including freeing all of the internal buffers.
* The struct must be reset with a call to netlbl_secattr_init() before reuse.
*
*/
static inline void netlbl_secattr_destroy(struct netlbl_lsm_secattr *secattr)
{
if (secattr->cache)
netlbl_secattr_cache_free(secattr->cache);
kfree(secattr->domain);
if (secattr->mls_cat)
netlbl_secattr_catmap_free(secattr->mls_cat);
}
/**
* netlbl_secattr_alloc - Allocate and initialize a netlbl_lsm_secattr struct
* @flags: the memory allocation flags
*
* Description:
* Allocate and initialize a netlbl_lsm_secattr struct. Returns a valid
* pointer on success, or NULL on failure.
*
*/
static inline struct netlbl_lsm_secattr *netlbl_secattr_alloc(gfp_t flags)
{
return kzalloc(sizeof(struct netlbl_lsm_secattr), flags);
}
/**
* netlbl_secattr_free - Frees a netlbl_lsm_secattr struct
* @secattr: the struct to free
*
* Description:
* Frees @secattr including all of the internal buffers.
*
*/
static inline void netlbl_secattr_free(struct netlbl_lsm_secattr *secattr)
{
netlbl_secattr_destroy(secattr);
kfree(secattr);
}
#ifdef CONFIG_NETLABEL
/*
* LSM security attribute operations
*/
int netlbl_secattr_catmap_walk(struct netlbl_lsm_secattr_catmap *catmap,
u32 offset);
int netlbl_secattr_catmap_walk_rng(struct netlbl_lsm_secattr_catmap *catmap,
u32 offset);
int netlbl_secattr_catmap_setbit(struct netlbl_lsm_secattr_catmap *catmap,
u32 bit,
gfp_t flags);
int netlbl_secattr_catmap_setrng(struct netlbl_lsm_secattr_catmap *catmap,
u32 start,
u32 end,
gfp_t flags);
/*
* LSM protocol operations
*/
int netlbl_enabled(void);
int netlbl_sock_setattr(struct sock *sk,
const struct netlbl_lsm_secattr *secattr);
int netlbl_sock_getattr(struct sock *sk,
struct netlbl_lsm_secattr *secattr);
int netlbl_skbuff_getattr(const struct sk_buff *skb,
struct netlbl_lsm_secattr *secattr);
void netlbl_skbuff_err(struct sk_buff *skb, int error);
/*
* LSM label mapping cache operations
*/
void netlbl_cache_invalidate(void);
int netlbl_cache_add(const struct sk_buff *skb,
const struct netlbl_lsm_secattr *secattr);
#else
static inline int netlbl_secattr_catmap_walk(
struct netlbl_lsm_secattr_catmap *catmap,
u32 offset)
{
return -ENOENT;
}
static inline int netlbl_secattr_catmap_walk_rng(
struct netlbl_lsm_secattr_catmap *catmap,
u32 offset)
{
return -ENOENT;
}
static inline int netlbl_secattr_catmap_setbit(
struct netlbl_lsm_secattr_catmap *catmap,
u32 bit,
gfp_t flags)
{
return 0;
}
static inline int netlbl_secattr_catmap_setrng(
struct netlbl_lsm_secattr_catmap *catmap,
u32 start,
u32 end,
gfp_t flags)
{
return 0;
}
static inline int netlbl_enabled(void)
{
return 0;
}
static inline int netlbl_sock_setattr(struct sock *sk,
const struct netlbl_lsm_secattr *secattr)
{
return -ENOSYS;
}
static inline int netlbl_sock_getattr(struct sock *sk,
struct netlbl_lsm_secattr *secattr)
{
return -ENOSYS;
}
static inline int netlbl_skbuff_getattr(const struct sk_buff *skb,
struct netlbl_lsm_secattr *secattr)
{
return -ENOSYS;
}
static inline void netlbl_skbuff_err(struct sk_buff *skb, int error)
{
return;
}
static inline void netlbl_cache_invalidate(void)
{
return;
}
static inline int netlbl_cache_add(const struct sk_buff *skb,
const struct netlbl_lsm_secattr *secattr)
{
return 0;
}
#endif /* CONFIG_NETLABEL */
#endif /* _NETLABEL_H */