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 <linux/audit.h>
  37. #include <net/sock.h>
  38. #include <net/netlink.h>
  39. #include <net/genetlink.h>
  40. #include <net/netlabel.h>
  41. #include <asm/bug.h>
  42. #include "netlabel_user.h"
  43. #include "netlabel_domainhash.h"
  44. #include "netlabel_unlabeled.h"
  45. /* Accept unlabeled packets flag */
  46. static DEFINE_SPINLOCK(netlabel_unlabel_acceptflg_lock);
  47. static u8 netlabel_unlabel_acceptflg = 0;
  48. /* NetLabel Generic NETLINK CIPSOv4 family */
  49. static struct genl_family netlbl_unlabel_gnl_family = {
  50. .id = GENL_ID_GENERATE,
  51. .hdrsize = 0,
  52. .name = NETLBL_NLTYPE_UNLABELED_NAME,
  53. .version = NETLBL_PROTO_VERSION,
  54. .maxattr = NLBL_UNLABEL_A_MAX,
  55. };
  56. /* NetLabel Netlink attribute policy */
  57. static const struct nla_policy netlbl_unlabel_genl_policy[NLBL_UNLABEL_A_MAX + 1] = {
  58. [NLBL_UNLABEL_A_ACPTFLG] = { .type = NLA_U8 },
  59. };
  60. /*
  61. * Helper Functions
  62. */
  63. /**
  64. * netlbl_unlabel_acceptflg_set - Set the unlabeled accept flag
  65. * @value: desired value
  66. * @audit_info: NetLabel audit information
  67. *
  68. * Description:
  69. * Set the value of the unlabeled accept flag to @value.
  70. *
  71. */
  72. static void netlbl_unlabel_acceptflg_set(u8 value,
  73. struct netlbl_audit *audit_info)
  74. {
  75. struct audit_buffer *audit_buf;
  76. u8 old_val;
  77. spin_lock(&netlabel_unlabel_acceptflg_lock);
  78. old_val = netlabel_unlabel_acceptflg;
  79. netlabel_unlabel_acceptflg = value;
  80. spin_unlock(&netlabel_unlabel_acceptflg_lock);
  81. audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_ALLOW,
  82. audit_info);
  83. if (audit_buf != NULL) {
  84. audit_log_format(audit_buf,
  85. " unlbl_accept=%u old=%u", value, old_val);
  86. audit_log_end(audit_buf);
  87. }
  88. }
  89. /*
  90. * NetLabel Command Handlers
  91. */
  92. /**
  93. * netlbl_unlabel_accept - Handle an ACCEPT message
  94. * @skb: the NETLINK buffer
  95. * @info: the Generic NETLINK info block
  96. *
  97. * Description:
  98. * Process a user generated ACCEPT message and set the accept flag accordingly.
  99. * Returns zero on success, negative values on failure.
  100. *
  101. */
  102. static int netlbl_unlabel_accept(struct sk_buff *skb, struct genl_info *info)
  103. {
  104. u8 value;
  105. struct netlbl_audit audit_info;
  106. if (info->attrs[NLBL_UNLABEL_A_ACPTFLG]) {
  107. value = nla_get_u8(info->attrs[NLBL_UNLABEL_A_ACPTFLG]);
  108. if (value == 1 || value == 0) {
  109. netlbl_netlink_auditinfo(skb, &audit_info);
  110. netlbl_unlabel_acceptflg_set(value, &audit_info);
  111. return 0;
  112. }
  113. }
  114. return -EINVAL;
  115. }
  116. /**
  117. * netlbl_unlabel_list - Handle a LIST message
  118. * @skb: the NETLINK buffer
  119. * @info: the Generic NETLINK info block
  120. *
  121. * Description:
  122. * Process a user generated LIST message and respond with the current status.
  123. * Returns zero on success, negative values on failure.
  124. *
  125. */
  126. static int netlbl_unlabel_list(struct sk_buff *skb, struct genl_info *info)
  127. {
  128. int ret_val = -EINVAL;
  129. struct sk_buff *ans_skb;
  130. void *data;
  131. ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
  132. if (ans_skb == NULL)
  133. goto list_failure;
  134. data = genlmsg_put_reply(ans_skb, info, &netlbl_unlabel_gnl_family,
  135. 0, NLBL_UNLABEL_C_LIST);
  136. if (data == NULL) {
  137. ret_val = -ENOMEM;
  138. goto list_failure;
  139. }
  140. rcu_read_lock();
  141. ret_val = nla_put_u8(ans_skb,
  142. NLBL_UNLABEL_A_ACPTFLG,
  143. netlabel_unlabel_acceptflg);
  144. rcu_read_unlock();
  145. if (ret_val != 0)
  146. goto list_failure;
  147. genlmsg_end(ans_skb, data);
  148. ret_val = genlmsg_reply(ans_skb, info);
  149. if (ret_val != 0)
  150. goto list_failure;
  151. return 0;
  152. list_failure:
  153. kfree_skb(ans_skb);
  154. return ret_val;
  155. }
  156. /*
  157. * NetLabel Generic NETLINK Command Definitions
  158. */
  159. static struct genl_ops netlbl_unlabel_genl_c_accept = {
  160. .cmd = NLBL_UNLABEL_C_ACCEPT,
  161. .flags = GENL_ADMIN_PERM,
  162. .policy = netlbl_unlabel_genl_policy,
  163. .doit = netlbl_unlabel_accept,
  164. .dumpit = NULL,
  165. };
  166. static struct genl_ops netlbl_unlabel_genl_c_list = {
  167. .cmd = NLBL_UNLABEL_C_LIST,
  168. .flags = 0,
  169. .policy = netlbl_unlabel_genl_policy,
  170. .doit = netlbl_unlabel_list,
  171. .dumpit = NULL,
  172. };
  173. /*
  174. * NetLabel Generic NETLINK Protocol Functions
  175. */
  176. /**
  177. * netlbl_unlabel_genl_init - Register the Unlabeled NetLabel component
  178. *
  179. * Description:
  180. * Register the unlabeled packet NetLabel component with the Generic NETLINK
  181. * mechanism. Returns zero on success, negative values on failure.
  182. *
  183. */
  184. int netlbl_unlabel_genl_init(void)
  185. {
  186. int ret_val;
  187. ret_val = genl_register_family(&netlbl_unlabel_gnl_family);
  188. if (ret_val != 0)
  189. return ret_val;
  190. ret_val = genl_register_ops(&netlbl_unlabel_gnl_family,
  191. &netlbl_unlabel_genl_c_accept);
  192. if (ret_val != 0)
  193. return ret_val;
  194. ret_val = genl_register_ops(&netlbl_unlabel_gnl_family,
  195. &netlbl_unlabel_genl_c_list);
  196. if (ret_val != 0)
  197. return ret_val;
  198. return 0;
  199. }
  200. /*
  201. * NetLabel KAPI Hooks
  202. */
  203. /**
  204. * netlbl_unlabel_getattr - Get the security attributes for an unlabled packet
  205. * @secattr: the security attributes
  206. *
  207. * Description:
  208. * Determine the security attributes, if any, for an unlabled packet and return
  209. * them in @secattr. Returns zero on success and negative values on failure.
  210. *
  211. */
  212. int netlbl_unlabel_getattr(struct netlbl_lsm_secattr *secattr)
  213. {
  214. int ret_val;
  215. rcu_read_lock();
  216. if (netlabel_unlabel_acceptflg == 1) {
  217. netlbl_secattr_init(secattr);
  218. ret_val = 0;
  219. } else
  220. ret_val = -ENOMSG;
  221. rcu_read_unlock();
  222. return ret_val;
  223. }
  224. /**
  225. * netlbl_unlabel_defconf - Set the default config to allow unlabeled packets
  226. *
  227. * Description:
  228. * Set the default NetLabel configuration to allow incoming unlabeled packets
  229. * and to send unlabeled network traffic by default.
  230. *
  231. */
  232. int netlbl_unlabel_defconf(void)
  233. {
  234. int ret_val;
  235. struct netlbl_dom_map *entry;
  236. struct netlbl_audit audit_info;
  237. /* Only the kernel is allowed to call this function and the only time
  238. * it is called is at bootup before the audit subsystem is reporting
  239. * messages so don't worry to much about these values. */
  240. security_task_getsecid(current, &audit_info.secid);
  241. audit_info.loginuid = 0;
  242. entry = kzalloc(sizeof(*entry), GFP_KERNEL);
  243. if (entry == NULL)
  244. return -ENOMEM;
  245. entry->type = NETLBL_NLTYPE_UNLABELED;
  246. ret_val = netlbl_domhsh_add_default(entry, &audit_info);
  247. if (ret_val != 0)
  248. return ret_val;
  249. netlbl_unlabel_acceptflg_set(1, &audit_info);
  250. return 0;
  251. }