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         rcu_read_lock();
  66         dom_entry = netlbl_domhsh_getentry(secattr->domain);
  67         if (dom_entry == NULL)
  68                 goto socket_setattr_return;
  69         switch (dom_entry->type) {
  70         case NETLBL_NLTYPE_CIPSOV4:
  71                 ret_val = cipso_v4_socket_setattr(sock,
  72                                                   dom_entry->type_def.cipsov4,
  73                                                   secattr);
  74                 break;
  75         case NETLBL_NLTYPE_UNLABELED:
  76                 ret_val = 0;
  77                 break;
  78         default:
  79                 ret_val = -ENOENT;
  80         }
  81
  82 socket_setattr_return:
  83         rcu_read_unlock();
  84         return ret_val;
  85 }
  86
  87 /**
  88  * netlbl_sock_getattr - Determine the security attributes of a sock
  89  * @sk: the sock
  90  * @secattr: the security attributes
  91  *
  92  * Description:
  93  * Examines the given sock to see any NetLabel style labeling has been
  94  * applied to the sock, if so it parses the socket label and returns the
  95  * security attributes in @secattr.  Returns zero on success, negative values
  96  * on failure.
  97  *
  98  */
  99 int netlbl_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr)
 100 {
 101         int ret_val;
 102
 103         ret_val = cipso_v4_sock_getattr(sk, secattr);
 104         if (ret_val == 0)
 105                 return 0;
 106
 107         return netlbl_unlabel_getattr(secattr);
 108 }
 109
 110 /**
 111  * netlbl_socket_getattr - Determine the security attributes of a socket
 112  * @sock: the socket
 113  * @secattr: the security attributes
 114  *
 115  * Description:
 116  * Examines the given socket to see any NetLabel style labeling has been
 117  * applied to the socket, if so it parses the socket label and returns the
 118  * security attributes in @secattr.  Returns zero on success, negative values
 119  * on failure.
 120  *
 121  */
 122 int netlbl_socket_getattr(const struct socket *sock,
 123                           struct netlbl_lsm_secattr *secattr)
 124 {
 125         int ret_val;
 126
 127         ret_val = cipso_v4_socket_getattr(sock, secattr);
 128         if (ret_val == 0)
 129                 return 0;
 130
 131         return netlbl_unlabel_getattr(secattr);
 132 }
 133
 134 /**
 135  * netlbl_skbuff_getattr - Determine the security attributes of a packet
 136  * @skb: the packet
 137  * @secattr: the security attributes
 138  *
 139  * Description:
 140  * Examines the given packet to see if a recognized form of packet labeling
 141  * is present, if so it parses the packet label and returns the security
 142  * attributes in @secattr.  Returns zero on success, negative values on
 143  * failure.
 144  *
 145  */
 146 int netlbl_skbuff_getattr(const struct sk_buff *skb,
 147                           struct netlbl_lsm_secattr *secattr)
 148 {
 149         int ret_val;
 150
 151         ret_val = cipso_v4_skbuff_getattr(skb, secattr);
 152         if (ret_val == 0)
 153                 return 0;
 154
 155         return netlbl_unlabel_getattr(secattr);
 156 }
 157
 158 /**
 159  * netlbl_skbuff_err - Handle a LSM error on a sk_buff
 160  * @skb: the packet
 161  * @error: the error code
 162  *
 163  * Description:
 164  * Deal with a LSM problem when handling the packet in @skb, typically this is
 165  * a permission denied problem (-EACCES).  The correct action is determined
 166  * according to the packet's labeling protocol.
 167  *
 168  */
 169 void netlbl_skbuff_err(struct sk_buff *skb, int error)
 170 {
 171         if (CIPSO_V4_OPTEXIST(skb))
 172                 cipso_v4_error(skb, error, 0);
 173 }
 174
 175 /**
 176  * netlbl_cache_invalidate - Invalidate all of the NetLabel protocol caches
 177  *
 178  * Description:
 179  * For all of the NetLabel protocols that support some form of label mapping
 180  * cache, invalidate the cache.  Returns zero on success, negative values on
 181  * error.
 182  *
 183  */
 184 void netlbl_cache_invalidate(void)
 185 {
 186         cipso_v4_cache_invalidate();
 187 }
 188
 189 /**
 190  * netlbl_cache_add - Add an entry to a NetLabel protocol cache
 191  * @skb: the packet
 192  * @secattr: the packet's security attributes
 193  *
 194  * Description:
 195  * Add the LSM security attributes for the given packet to the underlying
 196  * NetLabel protocol's label mapping cache.  Returns zero on success, negative
 197  * values on error.
 198  *
 199  */
 200 int netlbl_cache_add(const struct sk_buff *skb,
 201                      const struct netlbl_lsm_secattr *secattr)
 202 {
 203         if (secattr->cache == NULL)
 204                 return -ENOMSG;
 205
 206         if (CIPSO_V4_OPTEXIST(skb))
 207                 return cipso_v4_cache_add(skb, secattr);
 208
 209         return -ENOMSG;
 210 }
 211
 212 /*
 213  * Setup Functions
 214  */
 215
 216 /**
 217  * netlbl_init - Initialize NetLabel
 218  *
 219  * Description:
 220  * Perform the required NetLabel initialization before first use.
 221  *
 222  */
 223 static int __init netlbl_init(void)
 224 {
 225         int ret_val;
 226
 227         printk(KERN_INFO "NetLabel: Initializing\n");
 228         printk(KERN_INFO "NetLabel:  domain hash size = %u\n",
 229                (1 << NETLBL_DOMHSH_BITSIZE));
 230         printk(KERN_INFO "NetLabel:  protocols ="
 231                " UNLABELED"
 232                " CIPSOv4"
 233                "\n");
 234
 235         ret_val = netlbl_domhsh_init(NETLBL_DOMHSH_BITSIZE);
 236         if (ret_val != 0)
 237                 goto init_failure;
 238
 239         ret_val = netlbl_netlink_init();
 240         if (ret_val != 0)
 241                 goto init_failure;
 242
 243         ret_val = netlbl_unlabel_defconf();
 244         if (ret_val != 0)
 245                 goto init_failure;
 246         printk(KERN_INFO "NetLabel:  unlabeled traffic allowed by default\n");
 247
 248         return 0;
 249
 250 init_failure:
 251         panic("NetLabel: failed to initialize properly (%d)\n", ret_val);
 252 }
 253
 254 subsys_initcall(netlbl_init);