1 /* 2 * NetLabel System 3 * 4 * The NetLabel system manages static and dynamic label mappings for network 5 * protocols such as CIPSO and RIPSO. 6 * 7 * Author: Paul Moore <paul.moore@hp.com> 8 * 9 */ 10 11 /* 12 * (c) Copyright Hewlett-Packard Development Company, L.P., 2006 13 * 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. 18 * 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. 23 * 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 27 * 28 */ 29 30 #ifndef _NETLABEL_H 31 #define _NETLABEL_H 32 33 #include <linux/types.h> 34 #include <linux/skbuff.h> 35 #include <net/netlink.h> 36 37 /* 38 * NetLabel - A management interface for maintaining network packet label 39 * mapping tables for explicit packet labling protocols. 40 * 41 * Network protocols such as CIPSO and RIPSO require a label translation layer 42 * to convert the label on the packet into something meaningful on the host 43 * machine. In the current Linux implementation these mapping tables live 44 * inside the kernel; NetLabel provides a mechanism for user space applications 45 * to manage these mapping tables. 46 * 47 * NetLabel makes use of the Generic NETLINK mechanism as a transport layer to 48 * send messages between kernel and user space. The general format of a 49 * NetLabel message is shown below: 50 * 51 * +-----------------+-------------------+--------- --- -- - 52 * | struct nlmsghdr | struct genlmsghdr | payload 53 * +-----------------+-------------------+--------- --- -- - 54 * 55 * The 'nlmsghdr' and 'genlmsghdr' structs should be dealt with like normal. 56 * The payload is dependent on the subsystem specified in the 57 * 'nlmsghdr->nlmsg_type' and should be defined below, supporting functions 58 * should be defined in the corresponding net/netlabel/netlabel_<subsys>.h|c 59 * file. All of the fields in the NetLabel payload are NETLINK attributes, the 60 * length of each field is the length of the NETLINK attribute payload, see 61 * include/net/netlink.h for more information on NETLINK attributes. 62 * 63 */ 64 65 /* 66 * NetLabel NETLINK protocol 67 */ 68 69 #define NETLBL_PROTO_VERSION 1 70 71 /* NetLabel NETLINK types/families */ 72 #define NETLBL_NLTYPE_NONE 0 73 #define NETLBL_NLTYPE_MGMT 1 74 #define NETLBL_NLTYPE_MGMT_NAME "NLBL_MGMT" 75 #define NETLBL_NLTYPE_RIPSO 2 76 #define NETLBL_NLTYPE_RIPSO_NAME "NLBL_RIPSO" 77 #define NETLBL_NLTYPE_CIPSOV4 3 78 #define NETLBL_NLTYPE_CIPSOV4_NAME "NLBL_CIPSOv4" 79 #define NETLBL_NLTYPE_CIPSOV6 4 80 #define NETLBL_NLTYPE_CIPSOV6_NAME "NLBL_CIPSOv6" 81 #define NETLBL_NLTYPE_UNLABELED 5 82 #define NETLBL_NLTYPE_UNLABELED_NAME "NLBL_UNLBL" 83 84 /* NetLabel return codes */ 85 #define NETLBL_E_OK 0 86 87 /* 88 * Helper functions 89 */ 90 91 #define NETLBL_LEN_U8 nla_total_size(sizeof(u8)) 92 #define NETLBL_LEN_U16 nla_total_size(sizeof(u16)) 93 #define NETLBL_LEN_U32 nla_total_size(sizeof(u32)) 94 95 /** 96 * netlbl_netlink_alloc_skb - Allocate a NETLINK message buffer 97 * @head: the amount of headroom in bytes 98 * @body: the desired size (minus headroom) in bytes 99 * @gfp_flags: the alloc flags to pass to alloc_skb() 100 * 101 * Description: 102 * Allocate a NETLINK message buffer based on the sizes given in @head and 103 * @body. If @head is greater than zero skb_reserve() is called to reserve 104 * @head bytes at the start of the buffer. Returns a valid sk_buff pointer on 105 * success, NULL on failure. 106 * 107 */ 108 static inline struct sk_buff *netlbl_netlink_alloc_skb(size_t head, 109 size_t body, 110 int gfp_flags) 111 { 112 struct sk_buff *skb; 113 114 skb = alloc_skb(NLMSG_ALIGN(head + body), gfp_flags); 115 if (skb == NULL) 116 return NULL; 117 if (head > 0) { 118 skb_reserve(skb, head); 119 if (skb_tailroom(skb) < body) { 120 kfree_skb(skb); 121 return NULL; 122 } 123 } 124 125 return skb; 126 } 127 128 /* 129 * NetLabel - Kernel API for accessing the network packet label mappings. 130 * 131 * The following functions are provided for use by other kernel modules, 132 * specifically kernel LSM modules, to provide a consistent, transparent API 133 * for dealing with explicit packet labeling protocols such as CIPSO and 134 * RIPSO. The functions defined here are implemented in the 135 * net/netlabel/netlabel_kapi.c file. 136 * 137 */ 138 139 /* Domain mapping definition struct */ 140 struct netlbl_dom_map; 141 142 /* Domain mapping operations */ 143 int netlbl_domhsh_remove(const char *domain); 144 145 /* LSM security attributes */ 146 struct netlbl_lsm_cache { 147 void (*free) (const void *data); 148 void *data; 149 }; 150 struct netlbl_lsm_secattr { 151 char *domain; 152 153 u32 mls_lvl; 154 u32 mls_lvl_vld; 155 unsigned char *mls_cat; 156 size_t mls_cat_len; 157 158 struct netlbl_lsm_cache cache; 159 }; 160 161 /* 162 * LSM security attribute operations 163 */ 164 165 166 /** 167 * netlbl_secattr_init - Initialize a netlbl_lsm_secattr struct 168 * @secattr: the struct to initialize 169 * 170 * Description: 171 * Initialize an already allocated netlbl_lsm_secattr struct. Returns zero on 172 * success, negative values on error. 173 * 174 */ 175 static inline int netlbl_secattr_init(struct netlbl_lsm_secattr *secattr) 176 { 177 memset(secattr, 0, sizeof(*secattr)); 178 return 0; 179 } 180 181 /** 182 * netlbl_secattr_destroy - Clears a netlbl_lsm_secattr struct 183 * @secattr: the struct to clear 184 * @clear_cache: cache clear flag 185 * 186 * Description: 187 * Destroys the @secattr struct, including freeing all of the internal buffers. 188 * If @clear_cache is true then free the cache fields, otherwise leave them 189 * intact. The struct must be reset with a call to netlbl_secattr_init() 190 * before reuse. 191 * 192 */ 193 static inline void netlbl_secattr_destroy(struct netlbl_lsm_secattr *secattr, 194 u32 clear_cache) 195 { 196 if (clear_cache && secattr->cache.data != NULL && secattr->cache.free) 197 secattr->cache.free(secattr->cache.data); 198 kfree(secattr->domain); 199 kfree(secattr->mls_cat); 200 } 201 202 /** 203 * netlbl_secattr_alloc - Allocate and initialize a netlbl_lsm_secattr struct 204 * @flags: the memory allocation flags 205 * 206 * Description: 207 * Allocate and initialize a netlbl_lsm_secattr struct. Returns a valid 208 * pointer on success, or NULL on failure. 209 * 210 */ 211 static inline struct netlbl_lsm_secattr *netlbl_secattr_alloc(int flags) 212 { 213 return kzalloc(sizeof(struct netlbl_lsm_secattr), flags); 214 } 215 216 /** 217 * netlbl_secattr_free - Frees a netlbl_lsm_secattr struct 218 * @secattr: the struct to free 219 * @clear_cache: cache clear flag 220 * 221 * Description: 222 * Frees @secattr including all of the internal buffers. If @clear_cache is 223 * true then free the cache fields, otherwise leave them intact. 224 * 225 */ 226 static inline void netlbl_secattr_free(struct netlbl_lsm_secattr *secattr, 227 u32 clear_cache) 228 { 229 netlbl_secattr_destroy(secattr, clear_cache); 230 kfree(secattr); 231 } 232 233 /* 234 * LSM protocol operations 235 */ 236 237 #ifdef CONFIG_NETLABEL 238 int netlbl_socket_setattr(const struct socket *sock, 239 const struct netlbl_lsm_secattr *secattr); 240 int netlbl_socket_getattr(const struct socket *sock, 241 struct netlbl_lsm_secattr *secattr); 242 int netlbl_skbuff_getattr(const struct sk_buff *skb, 243 struct netlbl_lsm_secattr *secattr); 244 void netlbl_skbuff_err(struct sk_buff *skb, int error); 245 #else 246 static inline int netlbl_socket_setattr(const struct socket *sock, 247 const struct netlbl_lsm_secattr *secattr) 248 { 249 return -ENOSYS; 250 } 251 252 static inline int netlbl_socket_getattr(const struct socket *sock, 253 struct netlbl_lsm_secattr *secattr) 254 { 255 return -ENOSYS; 256 } 257 258 static inline int netlbl_skbuff_getattr(const struct sk_buff *skb, 259 struct netlbl_lsm_secattr *secattr) 260 { 261 return -ENOSYS; 262 } 263 264 static inline void netlbl_skbuff_err(struct sk_buff *skb, int error) 265 { 266 return; 267 } 268 #endif /* CONFIG_NETLABEL */ 269 270 /* 271 * LSM label mapping cache operations 272 */ 273 274 #ifdef CONFIG_NETLABEL 275 void netlbl_cache_invalidate(void); 276 int netlbl_cache_add(const struct sk_buff *skb, 277 const struct netlbl_lsm_secattr *secattr); 278 #else 279 static inline void netlbl_cache_invalidate(void) 280 { 281 return; 282 } 283 284 static inline int netlbl_cache_add(const struct sk_buff *skb, 285 const struct netlbl_lsm_secattr *secattr) 286 { 287 return 0; 288 } 289 #endif /* CONFIG_NETLABEL */ 290 291 #endif /* _NETLABEL_H */ 292