4 * The NetLabel system manages static and dynamic label mappings for network
5 * protocols such as CIPSO and RIPSO.
7 * Author: Paul Moore <paul.moore@hp.com>
12 * (c) Copyright Hewlett-Packard Development Company, L.P., 2006
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
22 * the GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, write to the Free Software
26 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
33 #include <linux/types.h>
34 #include <linux/net.h>
35 #include <linux/skbuff.h>
36 #include <net/netlink.h>
39 * NetLabel - A management interface for maintaining network packet label
40 * mapping tables for explicit packet labling protocols.
42 * Network protocols such as CIPSO and RIPSO require a label translation layer
43 * to convert the label on the packet into something meaningful on the host
44 * machine. In the current Linux implementation these mapping tables live
45 * inside the kernel; NetLabel provides a mechanism for user space applications
46 * to manage these mapping tables.
48 * NetLabel makes use of the Generic NETLINK mechanism as a transport layer to
49 * send messages between kernel and user space. The general format of a
50 * NetLabel message is shown below:
52 * +-----------------+-------------------+--------- --- -- -
53 * | struct nlmsghdr | struct genlmsghdr | payload
54 * +-----------------+-------------------+--------- --- -- -
56 * The 'nlmsghdr' and 'genlmsghdr' structs should be dealt with like normal.
57 * The payload is dependent on the subsystem specified in the
58 * 'nlmsghdr->nlmsg_type' and should be defined below, supporting functions
59 * should be defined in the corresponding net/netlabel/netlabel_<subsys>.h|c
60 * file. All of the fields in the NetLabel payload are NETLINK attributes, the
61 * length of each field is the length of the NETLINK attribute payload, see
62 * include/net/netlink.h for more information on NETLINK attributes.
67 * NetLabel NETLINK protocol
70 #define NETLBL_PROTO_VERSION 1
72 /* NetLabel NETLINK types/families */
73 #define NETLBL_NLTYPE_NONE 0
74 #define NETLBL_NLTYPE_MGMT 1
75 #define NETLBL_NLTYPE_MGMT_NAME "NLBL_MGMT"
76 #define NETLBL_NLTYPE_RIPSO 2
77 #define NETLBL_NLTYPE_RIPSO_NAME "NLBL_RIPSO"
78 #define NETLBL_NLTYPE_CIPSOV4 3
79 #define NETLBL_NLTYPE_CIPSOV4_NAME "NLBL_CIPSOv4"
80 #define NETLBL_NLTYPE_CIPSOV6 4
81 #define NETLBL_NLTYPE_CIPSOV6_NAME "NLBL_CIPSOv6"
82 #define NETLBL_NLTYPE_UNLABELED 5
83 #define NETLBL_NLTYPE_UNLABELED_NAME "NLBL_UNLBL"
85 /* NetLabel return codes */
92 #define NETLBL_LEN_U8 nla_total_size(sizeof(u8))
93 #define NETLBL_LEN_U16 nla_total_size(sizeof(u16))
94 #define NETLBL_LEN_U32 nla_total_size(sizeof(u32))
97 * netlbl_netlink_alloc_skb - Allocate a NETLINK message buffer
98 * @head: the amount of headroom in bytes
99 * @body: the desired size (minus headroom) in bytes
100 * @gfp_flags: the alloc flags to pass to alloc_skb()
103 * Allocate a NETLINK message buffer based on the sizes given in @head and
104 * @body. If @head is greater than zero skb_reserve() is called to reserve
105 * @head bytes at the start of the buffer. Returns a valid sk_buff pointer on
106 * success, NULL on failure.
109 static inline struct sk_buff *netlbl_netlink_alloc_skb(size_t head,
115 skb = alloc_skb(NLMSG_ALIGN(head + body), gfp_flags);
119 skb_reserve(skb, head);
120 if (skb_tailroom(skb) < body) {
130 * NetLabel - Kernel API for accessing the network packet label mappings.
132 * The following functions are provided for use by other kernel modules,
133 * specifically kernel LSM modules, to provide a consistent, transparent API
134 * for dealing with explicit packet labeling protocols such as CIPSO and
135 * RIPSO. The functions defined here are implemented in the
136 * net/netlabel/netlabel_kapi.c file.
140 /* Domain mapping definition struct */
141 struct netlbl_dom_map;
143 /* Domain mapping operations */
144 int netlbl_domhsh_remove(const char *domain);
146 /* LSM security attributes */
147 struct netlbl_lsm_cache {
148 void (*free) (const void *data);
151 struct netlbl_lsm_secattr {
156 unsigned char *mls_cat;
159 struct netlbl_lsm_cache cache;
163 * LSM security attribute operations
168 * netlbl_secattr_init - Initialize a netlbl_lsm_secattr struct
169 * @secattr: the struct to initialize
172 * Initialize an already allocated netlbl_lsm_secattr struct. Returns zero on
173 * success, negative values on error.
176 static inline int netlbl_secattr_init(struct netlbl_lsm_secattr *secattr)
178 memset(secattr, 0, sizeof(*secattr));
183 * netlbl_secattr_destroy - Clears a netlbl_lsm_secattr struct
184 * @secattr: the struct to clear
185 * @clear_cache: cache clear flag
188 * Destroys the @secattr struct, including freeing all of the internal buffers.
189 * If @clear_cache is true then free the cache fields, otherwise leave them
190 * intact. The struct must be reset with a call to netlbl_secattr_init()
194 static inline void netlbl_secattr_destroy(struct netlbl_lsm_secattr *secattr,
197 if (clear_cache && secattr->cache.data != NULL && secattr->cache.free)
198 secattr->cache.free(secattr->cache.data);
199 kfree(secattr->domain);
200 kfree(secattr->mls_cat);
204 * netlbl_secattr_alloc - Allocate and initialize a netlbl_lsm_secattr struct
205 * @flags: the memory allocation flags
208 * Allocate and initialize a netlbl_lsm_secattr struct. Returns a valid
209 * pointer on success, or NULL on failure.
212 static inline struct netlbl_lsm_secattr *netlbl_secattr_alloc(int flags)
214 return kzalloc(sizeof(struct netlbl_lsm_secattr), flags);
218 * netlbl_secattr_free - Frees a netlbl_lsm_secattr struct
219 * @secattr: the struct to free
220 * @clear_cache: cache clear flag
223 * Frees @secattr including all of the internal buffers. If @clear_cache is
224 * true then free the cache fields, otherwise leave them intact.
227 static inline void netlbl_secattr_free(struct netlbl_lsm_secattr *secattr,
230 netlbl_secattr_destroy(secattr, clear_cache);
235 * LSM protocol operations
238 #ifdef CONFIG_NETLABEL
239 int netlbl_socket_setattr(const struct socket *sock,
240 const struct netlbl_lsm_secattr *secattr);
241 int netlbl_socket_getattr(const struct socket *sock,
242 struct netlbl_lsm_secattr *secattr);
243 int netlbl_skbuff_getattr(const struct sk_buff *skb,
244 struct netlbl_lsm_secattr *secattr);
245 void netlbl_skbuff_err(struct sk_buff *skb, int error);
247 static inline int netlbl_socket_setattr(const struct socket *sock,
248 const struct netlbl_lsm_secattr *secattr)
253 static inline int netlbl_socket_getattr(const struct socket *sock,
254 struct netlbl_lsm_secattr *secattr)
259 static inline int netlbl_skbuff_getattr(const struct sk_buff *skb,
260 struct netlbl_lsm_secattr *secattr)
265 static inline void netlbl_skbuff_err(struct sk_buff *skb, int error)
269 #endif /* CONFIG_NETLABEL */
272 * LSM label mapping cache operations
275 #ifdef CONFIG_NETLABEL
276 void netlbl_cache_invalidate(void);
277 int netlbl_cache_add(const struct sk_buff *skb,
278 const struct netlbl_lsm_secattr *secattr);
280 static inline void netlbl_cache_invalidate(void)
285 static inline int netlbl_cache_add(const struct sk_buff *skb,
286 const struct netlbl_lsm_secattr *secattr)
290 #endif /* CONFIG_NETLABEL */
292 #endif /* _NETLABEL_H */