/*
* 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/skbuff.h>
#include <net/netlink.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, the
* length of each field is the length of the NETLINK attribute payload, see
* include/net/netlink.h 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 return codes */
#define NETLBL_E_OK 0
/*
* Helper functions
*/
#define NETLBL_LEN_U8 nla_total_size(sizeof(u8))
#define NETLBL_LEN_U16 nla_total_size(sizeof(u16))
#define NETLBL_LEN_U32 nla_total_size(sizeof(u32))
/**
* netlbl_netlink_alloc_skb - Allocate a NETLINK message buffer
* @head: the amount of headroom in bytes
* @body: the desired size (minus headroom) in bytes
* @gfp_flags: the alloc flags to pass to alloc_skb()
*
* Description:
* Allocate a NETLINK message buffer based on the sizes given in @head and
* @body. If @head is greater than zero skb_reserve() is called to reserve
* @head bytes at the start of the buffer. Returns a valid sk_buff pointer on
* success, NULL on failure.
*
*/
static inline struct sk_buff *netlbl_netlink_alloc_skb(size_t head,
size_t body,
int gfp_flags)
{
struct sk_buff *skb;
skb = alloc_skb(NLMSG_ALIGN(head + body), gfp_flags);
if (skb == NULL)
return NULL;
if (head > 0) {
skb_reserve(skb, head);
if (skb_tailroom(skb) < body) {
kfree_skb(skb);
return NULL;
}
}
return skb;
}
/*
* 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.
*
*/
/* Domain mapping definition struct */
struct netlbl_dom_map;
/* Domain mapping operations */
int netlbl_domhsh_remove(const char *domain);
/* LSM security attributes */
struct netlbl_lsm_cache {
void (*free) (const void *data);
void *data;
};
struct netlbl_lsm_secattr {
char *domain;
u32 mls_lvl;
u32 mls_lvl_vld;
unsigned char *mls_cat;
size_t mls_cat_len;
struct netlbl_lsm_cache cache;
};
/*
* LSM security attribute operations
*/
/**
* netlbl_secattr_init - Initialize a netlbl_lsm_secattr struct
* @secattr: the struct to initialize
*
* Description:
* Initialize an already allocated netlbl_lsm_secattr struct. Returns zero on
* success, negative values on error.
*
*/
static inline int netlbl_secattr_init(struct netlbl_lsm_secattr *secattr)
{
memset(secattr, 0, sizeof(*secattr));
return 0;
}
/**
* netlbl_secattr_destroy - Clears a netlbl_lsm_secattr struct
* @secattr: the struct to clear
* @clear_cache: cache clear flag
*
* Description:
* Destroys the @secattr struct, including freeing all of the internal buffers.
* If @clear_cache is true then free the cache fields, otherwise leave them
* intact. 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,
u32 clear_cache)
{
if (clear_cache && secattr->cache.data != NULL && secattr->cache.free)
secattr->cache.free(secattr->cache.data);
kfree(secattr->domain);
kfree(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(int flags)
{
return kzalloc(sizeof(struct netlbl_lsm_secattr), flags);
}
/**
* netlbl_secattr_free - Frees a netlbl_lsm_secattr struct
* @secattr: the struct to free
* @clear_cache: cache clear flag
*
* Description:
* Frees @secattr including all of the internal buffers. If @clear_cache is
* true then free the cache fields, otherwise leave them intact.
*
*/
static inline void netlbl_secattr_free(struct netlbl_lsm_secattr *secattr,
u32 clear_cache)
{
netlbl_secattr_destroy(secattr, clear_cache);
kfree(secattr);
}
/*
* LSM protocol operations
*/
#ifdef CONFIG_NETLABEL
int netlbl_socket_setattr(const struct socket *sock,
const struct netlbl_lsm_secattr *secattr);
int netlbl_socket_getattr(const struct socket *sock,
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);
#else
static inline int netlbl_socket_setattr(const struct socket *sock,
const struct netlbl_lsm_secattr *secattr)
{
return -ENOSYS;
}
static inline int netlbl_socket_getattr(const struct socket *sock,
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;
}
#endif /* CONFIG_NETLABEL */
/*
* LSM label mapping cache operations
*/
#ifdef CONFIG_NETLABEL
void netlbl_cache_invalidate(void);
int netlbl_cache_add(const struct sk_buff *skb,
const struct netlbl_lsm_secattr *secattr);
#else
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 */
