net/netlabel/netlabel_kapi.c

   1 /*
   2  * NetLabel Kernel API
   3  *
   4  * This file defines the kernel API for the NetLabel system.  The NetLabel
   5  * system manages static and dynamic label mappings for network protocols such
   6  * as CIPSO and RIPSO.
   7  *
   8  * Author: Paul Moore <paul.moore@hp.com>
   9  *
  10  */
  11
  12 /*
  13  * (c) Copyright Hewlett-Packard Development Company, L.P., 2006
  14  *
  15  * This program is free software;  you can redistribute it and/or modify
  16  * it under the terms of the GNU General Public License as published by
  17  * the Free Software Foundation; either version 2 of the License, or
  18  * (at your option) any later version.
  19  *
  20  * This program is distributed in the hope that it will be useful,
  21  * but WITHOUT ANY WARRANTY;  without even the implied warranty of
  22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  23  * the GNU General Public License for more details.
  24  *
  25  * You should have received a copy of the GNU General Public License
  26  * along with this program;  if not, write to the Free Software
  27  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  28  *
  29  */
  30
  31 #include <linux/init.h>
  32 #include <linux/types.h>
  33 #include <net/ip.h>
  34 #include <net/netlabel.h>
  35 #include <net/cipso_ipv4.h>
  36 #include <asm/bug.h>
  37
  38 #include "netlabel_domainhash.h"
  39 #include "netlabel_unlabeled.h"
  40 #include "netlabel_user.h"
  41
  42 /*
  43  * LSM Functions
  44  */
  45
  46 /**
  47  * netlbl_socket_setattr - Label a socket using the correct protocol
  48  * @sock: the socket to label
  49  * @secattr: the security attributes
  50  *
  51  * Description:
  52  * Attach the correct label to the given socket using the security attributes
  53  * specified in @secattr.  This function requires exclusive access to
  54  * @sock->sk, which means it either needs to be in the process of being
  55  * created or locked via lock_sock(sock->sk).  Returns zero on success,
  56  * negative values on failure.
  57  *
  58  */
  59 int netlbl_socket_setattr(const struct socket *sock,
  60                           const struct netlbl_lsm_secattr *secattr)
  61 {
  62         int ret_val = -ENOENT;
  63         struct netlbl_dom_map *dom_entry;
  64
  65         if ((secattr->flags & NETLBL_SECATTR_DOMAIN) == 0)
  66                 return -ENOENT;
  67
  68         rcu_read_lock();
  69         dom_entry = netlbl_domhsh_getentry(secattr->domain);
  70         if (dom_entry == NULL)
  71                 goto socket_setattr_return;
  72         switch (dom_entry->type) {
  73         case NETLBL_NLTYPE_CIPSOV4:
  74                 ret_val = cipso_v4_socket_setattr(sock,
  75                                                   dom_entry->type_def.cipsov4,
  76                                                   secattr);
  77                 break;
  78         case NETLBL_NLTYPE_UNLABELED:
  79                 ret_val = 0;
  80                 break;
  81         default:
  82                 ret_val = -ENOENT;
  83         }
  84
  85 socket_setattr_return:
  86         rcu_read_unlock();
  87         return ret_val;
  88 }
  89
  90 /**
  91  * netlbl_sock_getattr - Determine the security attributes of a sock
  92  * @sk: the sock
  93  * @secattr: the security attributes
  94  *
  95  * Description:
  96  * Examines the given sock to see any NetLabel style labeling has been
  97  * applied to the sock, if so it parses the socket label and returns the
  98  * security attributes in @secattr.  Returns zero on success, negative values
  99  * on failure.
 100  *
 101  */
 102 int netlbl_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr)
 103 {
 104         int ret_val;
 105
 106         ret_val = cipso_v4_sock_getattr(sk, secattr);
 107         if (ret_val == 0)
 108                 return 0;
 109
 110         return netlbl_unlabel_getattr(secattr);
 111 }
 112
 113 /**
 114  * netlbl_socket_getattr - Determine the security attributes of a socket
 115  * @sock: the socket
 116  * @secattr: the security attributes
 117  *
 118  * Description:
 119  * Examines the given socket to see any NetLabel style labeling has been
 120  * applied to the socket, if so it parses the socket label and returns the
 121  * security attributes in @secattr.  Returns zero on success, negative values
 122  * on failure.
 123  *
 124  */
 125 int netlbl_socket_getattr(const struct socket *sock,
 126                           struct netlbl_lsm_secattr *secattr)
 127 {
 128         int ret_val;
 129
 130         ret_val = cipso_v4_socket_getattr(sock, secattr);
 131         if (ret_val == 0)
 132                 return 0;
 133
 134         return netlbl_unlabel_getattr(secattr);
 135 }
 136
 137 /**
 138  * netlbl_skbuff_getattr - Determine the security attributes of a packet
 139  * @skb: the packet
 140  * @secattr: the security attributes
 141  *
 142  * Description:
 143  * Examines the given packet to see if a recognized form of packet labeling
 144  * is present, if so it parses the packet label and returns the security
 145  * attributes in @secattr.  Returns zero on success, negative values on
 146  * failure.
 147  *
 148  */
 149 int netlbl_skbuff_getattr(const struct sk_buff *skb,
 150                           struct netlbl_lsm_secattr *secattr)
 151 {
 152         int ret_val;
 153
 154         ret_val = cipso_v4_skbuff_getattr(skb, secattr);
 155         if (ret_val == 0)
 156                 return 0;
 157
 158         return netlbl_unlabel_getattr(secattr);
 159 }
 160
 161 /**
 162  * netlbl_skbuff_err - Handle a LSM error on a sk_buff
 163  * @skb: the packet
 164  * @error: the error code
 165  *
 166  * Description:
 167  * Deal with a LSM problem when handling the packet in @skb, typically this is
 168  * a permission denied problem (-EACCES).  The correct action is determined
 169  * according to the packet's labeling protocol.
 170  *
 171  */
 172 void netlbl_skbuff_err(struct sk_buff *skb, int error)
 173 {
 174         if (CIPSO_V4_OPTEXIST(skb))
 175                 cipso_v4_error(skb, error, 0);
 176 }
 177
 178 /**
 179  * netlbl_cache_invalidate - Invalidate all of the NetLabel protocol caches
 180  *
 181  * Description:
 182  * For all of the NetLabel protocols that support some form of label mapping
 183  * cache, invalidate the cache.  Returns zero on success, negative values on
 184  * error.
 185  *
 186  */
 187 void netlbl_cache_invalidate(void)
 188 {
 189         cipso_v4_cache_invalidate();
 190 }
 191
 192 /**
 193  * netlbl_cache_add - Add an entry to a NetLabel protocol cache
 194  * @skb: the packet
 195  * @secattr: the packet's security attributes
 196  *
 197  * Description:
 198  * Add the LSM security attributes for the given packet to the underlying
 199  * NetLabel protocol's label mapping cache.  Returns zero on success, negative
 200  * values on error.
 201  *
 202  */
 203 int netlbl_cache_add(const struct sk_buff *skb,
 204                      const struct netlbl_lsm_secattr *secattr)
 205 {
 206         if ((secattr->flags & NETLBL_SECATTR_CACHE) == 0)
 207                 return -ENOMSG;
 208
 209         if (CIPSO_V4_OPTEXIST(skb))
 210                 return cipso_v4_cache_add(skb, secattr);
 211
 212         return -ENOMSG;
 213 }
 214
 215 /*
 216  * Setup Functions
 217  */
 218
 219 /**
 220  * netlbl_init - Initialize NetLabel
 221  *
 222  * Description:
 223  * Perform the required NetLabel initialization before first use.
 224  *
 225  */
 226 static int __init netlbl_init(void)
 227 {
 228         int ret_val;
 229
 230         printk(KERN_INFO "NetLabel: Initializing\n");
 231         printk(KERN_INFO "NetLabel:  domain hash size = %u\n",
 232                (1 << NETLBL_DOMHSH_BITSIZE));
 233         printk(KERN_INFO "NetLabel:  protocols ="
 234                " UNLABELED"
 235                " CIPSOv4"
 236                "\n");
 237
 238         ret_val = netlbl_domhsh_init(NETLBL_DOMHSH_BITSIZE);
 239         if (ret_val != 0)
 240                 goto init_failure;
 241
 242         ret_val = netlbl_netlink_init();
 243         if (ret_val != 0)
 244                 goto init_failure;
 245
 246         ret_val = netlbl_unlabel_defconf();
 247         if (ret_val != 0)
 248                 goto init_failure;
 249         printk(KERN_INFO "NetLabel:  unlabeled traffic allowed by default\n");
 250
 251         return 0;
 252
 253 init_failure:
 254         panic("NetLabel: failed to initialize properly (%d)\n", ret_val);
 255 }
 256
 257 subsys_initcall(netlbl_init);