netlabel_unlabeled.c 7.1 KB

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  1. /*
  2. * NetLabel Unlabeled Support
  3. *
  4. * This file defines functions for dealing with unlabeled packets for the
  5. * NetLabel system. The NetLabel system manages static and dynamic label
  6. * mappings for network protocols such as CIPSO and RIPSO.
  7. *
  8. * Author: Paul Moore <paul.moore@hp.com>
  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. #include <linux/types.h>
  30. #include <linux/rcupdate.h>
  31. #include <linux/list.h>
  32. #include <linux/spinlock.h>
  33. #include <linux/socket.h>
  34. #include <linux/string.h>
  35. #include <linux/skbuff.h>
  36. #include <net/sock.h>
  37. #include <net/netlink.h>
  38. #include <net/genetlink.h>
  39. #include <net/netlabel.h>
  40. #include <asm/bug.h>
  41. #include "netlabel_user.h"
  42. #include "netlabel_domainhash.h"
  43. #include "netlabel_unlabeled.h"
  44. /* Accept unlabeled packets flag */
  45. static DEFINE_SPINLOCK(netlabel_unlabel_acceptflg_lock);
  46. static u8 netlabel_unlabel_acceptflg = 0;
  47. /* NetLabel Generic NETLINK CIPSOv4 family */
  48. static struct genl_family netlbl_unlabel_gnl_family = {
  49. .id = GENL_ID_GENERATE,
  50. .hdrsize = 0,
  51. .name = NETLBL_NLTYPE_UNLABELED_NAME,
  52. .version = NETLBL_PROTO_VERSION,
  53. .maxattr = NLBL_UNLABEL_A_MAX,
  54. };
  55. /* NetLabel Netlink attribute policy */
  56. static struct nla_policy netlbl_unlabel_genl_policy[NLBL_UNLABEL_A_MAX + 1] = {
  57. [NLBL_UNLABEL_A_ACPTFLG] = { .type = NLA_U8 },
  58. };
  59. /*
  60. * Helper Functions
  61. */
  62. /**
  63. * netlbl_unlabel_acceptflg_set - Set the unlabeled accept flag
  64. * @value: desired value
  65. * @audit_info: NetLabel audit information
  66. *
  67. * Description:
  68. * Set the value of the unlabeled accept flag to @value.
  69. *
  70. */
  71. static void netlbl_unlabel_acceptflg_set(u8 value,
  72. struct netlbl_audit *audit_info)
  73. {
  74. struct audit_buffer *audit_buf;
  75. u8 old_val;
  76. rcu_read_lock();
  77. old_val = netlabel_unlabel_acceptflg;
  78. spin_lock(&netlabel_unlabel_acceptflg_lock);
  79. netlabel_unlabel_acceptflg = value;
  80. spin_unlock(&netlabel_unlabel_acceptflg_lock);
  81. rcu_read_unlock();
  82. audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_ALLOW,
  83. audit_info);
  84. audit_log_format(audit_buf, " unlbl_accept=%u old=%u", value, old_val);
  85. audit_log_end(audit_buf);
  86. }
  87. /*
  88. * NetLabel Command Handlers
  89. */
  90. /**
  91. * netlbl_unlabel_accept - Handle an ACCEPT message
  92. * @skb: the NETLINK buffer
  93. * @info: the Generic NETLINK info block
  94. *
  95. * Description:
  96. * Process a user generated ACCEPT message and set the accept flag accordingly.
  97. * Returns zero on success, negative values on failure.
  98. *
  99. */
  100. static int netlbl_unlabel_accept(struct sk_buff *skb, struct genl_info *info)
  101. {
  102. u8 value;
  103. struct netlbl_audit audit_info;
  104. if (info->attrs[NLBL_UNLABEL_A_ACPTFLG]) {
  105. value = nla_get_u8(info->attrs[NLBL_UNLABEL_A_ACPTFLG]);
  106. if (value == 1 || value == 0) {
  107. netlbl_netlink_auditinfo(skb, &audit_info);
  108. netlbl_unlabel_acceptflg_set(value, &audit_info);
  109. return 0;
  110. }
  111. }
  112. return -EINVAL;
  113. }
  114. /**
  115. * netlbl_unlabel_list - Handle a LIST message
  116. * @skb: the NETLINK buffer
  117. * @info: the Generic NETLINK info block
  118. *
  119. * Description:
  120. * Process a user generated LIST message and respond with the current status.
  121. * Returns zero on success, negative values on failure.
  122. *
  123. */
  124. static int netlbl_unlabel_list(struct sk_buff *skb, struct genl_info *info)
  125. {
  126. int ret_val = -EINVAL;
  127. struct sk_buff *ans_skb;
  128. void *data;
  129. ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
  130. if (ans_skb == NULL)
  131. goto list_failure;
  132. data = genlmsg_put_reply(ans_skb, info, &netlbl_unlabel_gnl_family,
  133. 0, NLBL_UNLABEL_C_LIST);
  134. if (data == NULL) {
  135. ret_val = -ENOMEM;
  136. goto list_failure;
  137. }
  138. rcu_read_lock();
  139. ret_val = nla_put_u8(ans_skb,
  140. NLBL_UNLABEL_A_ACPTFLG,
  141. netlabel_unlabel_acceptflg);
  142. rcu_read_unlock();
  143. if (ret_val != 0)
  144. goto list_failure;
  145. genlmsg_end(ans_skb, data);
  146. ret_val = genlmsg_reply(ans_skb, info);
  147. if (ret_val != 0)
  148. goto list_failure;
  149. return 0;
  150. list_failure:
  151. kfree(ans_skb);
  152. return ret_val;
  153. }
  154. /*
  155. * NetLabel Generic NETLINK Command Definitions
  156. */
  157. static struct genl_ops netlbl_unlabel_genl_c_accept = {
  158. .cmd = NLBL_UNLABEL_C_ACCEPT,
  159. .flags = GENL_ADMIN_PERM,
  160. .policy = netlbl_unlabel_genl_policy,
  161. .doit = netlbl_unlabel_accept,
  162. .dumpit = NULL,
  163. };
  164. static struct genl_ops netlbl_unlabel_genl_c_list = {
  165. .cmd = NLBL_UNLABEL_C_LIST,
  166. .flags = 0,
  167. .policy = netlbl_unlabel_genl_policy,
  168. .doit = netlbl_unlabel_list,
  169. .dumpit = NULL,
  170. };
  171. /*
  172. * NetLabel Generic NETLINK Protocol Functions
  173. */
  174. /**
  175. * netlbl_unlabel_genl_init - Register the Unlabeled NetLabel component
  176. *
  177. * Description:
  178. * Register the unlabeled packet NetLabel component with the Generic NETLINK
  179. * mechanism. Returns zero on success, negative values on failure.
  180. *
  181. */
  182. int netlbl_unlabel_genl_init(void)
  183. {
  184. int ret_val;
  185. ret_val = genl_register_family(&netlbl_unlabel_gnl_family);
  186. if (ret_val != 0)
  187. return ret_val;
  188. ret_val = genl_register_ops(&netlbl_unlabel_gnl_family,
  189. &netlbl_unlabel_genl_c_accept);
  190. if (ret_val != 0)
  191. return ret_val;
  192. ret_val = genl_register_ops(&netlbl_unlabel_gnl_family,
  193. &netlbl_unlabel_genl_c_list);
  194. if (ret_val != 0)
  195. return ret_val;
  196. return 0;
  197. }
  198. /*
  199. * NetLabel KAPI Hooks
  200. */
  201. /**
  202. * netlbl_unlabel_getattr - Get the security attributes for an unlabled packet
  203. * @secattr: the security attributes
  204. *
  205. * Description:
  206. * Determine the security attributes, if any, for an unlabled packet and return
  207. * them in @secattr. Returns zero on success and negative values on failure.
  208. *
  209. */
  210. int netlbl_unlabel_getattr(struct netlbl_lsm_secattr *secattr)
  211. {
  212. int ret_val;
  213. rcu_read_lock();
  214. if (netlabel_unlabel_acceptflg == 1) {
  215. netlbl_secattr_init(secattr);
  216. ret_val = 0;
  217. } else
  218. ret_val = -ENOMSG;
  219. rcu_read_unlock();
  220. return ret_val;
  221. }
  222. /**
  223. * netlbl_unlabel_defconf - Set the default config to allow unlabeled packets
  224. *
  225. * Description:
  226. * Set the default NetLabel configuration to allow incoming unlabeled packets
  227. * and to send unlabeled network traffic by default.
  228. *
  229. */
  230. int netlbl_unlabel_defconf(void)
  231. {
  232. int ret_val;
  233. struct netlbl_dom_map *entry;
  234. struct netlbl_audit audit_info;
  235. /* Only the kernel is allowed to call this function and the only time
  236. * it is called is at bootup before the audit subsystem is reporting
  237. * messages so don't worry to much about these values. */
  238. security_task_getsecid(current, &audit_info.secid);
  239. audit_info.loginuid = 0;
  240. entry = kzalloc(sizeof(*entry), GFP_KERNEL);
  241. if (entry == NULL)
  242. return -ENOMEM;
  243. entry->type = NETLBL_NLTYPE_UNLABELED;
  244. ret_val = netlbl_domhsh_add_default(entry, &audit_info);
  245. if (ret_val != 0)
  246. return ret_val;
  247. netlbl_unlabel_acceptflg_set(1, &audit_info);
  248. return 0;
  249. }