net.c 9.3 KB

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  1. /*
  2. * net/tipc/net.c: TIPC network routing code
  3. *
  4. * Copyright (c) 1995-2006, 2014, Ericsson AB
  5. * Copyright (c) 2005, 2010-2011, Wind River Systems
  6. * All rights reserved.
  7. *
  8. * Redistribution and use in source and binary forms, with or without
  9. * modification, are permitted provided that the following conditions are met:
  10. *
  11. * 1. Redistributions of source code must retain the above copyright
  12. * notice, this list of conditions and the following disclaimer.
  13. * 2. Redistributions in binary form must reproduce the above copyright
  14. * notice, this list of conditions and the following disclaimer in the
  15. * documentation and/or other materials provided with the distribution.
  16. * 3. Neither the names of the copyright holders nor the names of its
  17. * contributors may be used to endorse or promote products derived from
  18. * this software without specific prior written permission.
  19. *
  20. * Alternatively, this software may be distributed under the terms of the
  21. * GNU General Public License ("GPL") version 2 as published by the Free
  22. * Software Foundation.
  23. *
  24. * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  25. * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26. * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27. * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  28. * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29. * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  30. * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  31. * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  32. * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  33. * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  34. * POSSIBILITY OF SUCH DAMAGE.
  35. */
  36. #include "core.h"
  37. #include "net.h"
  38. #include "name_distr.h"
  39. #include "subscr.h"
  40. #include "socket.h"
  41. #include "node.h"
  42. #include "bcast.h"
  43. #include "netlink.h"
  44. #include "monitor.h"
  45. /*
  46. * The TIPC locking policy is designed to ensure a very fine locking
  47. * granularity, permitting complete parallel access to individual
  48. * port and node/link instances. The code consists of four major
  49. * locking domains, each protected with their own disjunct set of locks.
  50. *
  51. * 1: The bearer level.
  52. * RTNL lock is used to serialize the process of configuring bearer
  53. * on update side, and RCU lock is applied on read side to make
  54. * bearer instance valid on both paths of message transmission and
  55. * reception.
  56. *
  57. * 2: The node and link level.
  58. * All node instances are saved into two tipc_node_list and node_htable
  59. * lists. The two lists are protected by node_list_lock on write side,
  60. * and they are guarded with RCU lock on read side. Especially node
  61. * instance is destroyed only when TIPC module is removed, and we can
  62. * confirm that there has no any user who is accessing the node at the
  63. * moment. Therefore, Except for iterating the two lists within RCU
  64. * protection, it's no needed to hold RCU that we access node instance
  65. * in other places.
  66. *
  67. * In addition, all members in node structure including link instances
  68. * are protected by node spin lock.
  69. *
  70. * 3: The transport level of the protocol.
  71. * This consists of the structures port, (and its user level
  72. * representations, such as user_port and tipc_sock), reference and
  73. * tipc_user (port.c, reg.c, socket.c).
  74. *
  75. * This layer has four different locks:
  76. * - The tipc_port spin_lock. This is protecting each port instance
  77. * from parallel data access and removal. Since we can not place
  78. * this lock in the port itself, it has been placed in the
  79. * corresponding reference table entry, which has the same life
  80. * cycle as the module. This entry is difficult to access from
  81. * outside the TIPC core, however, so a pointer to the lock has
  82. * been added in the port instance, -to be used for unlocking
  83. * only.
  84. * - A read/write lock to protect the reference table itself (teg.c).
  85. * (Nobody is using read-only access to this, so it can just as
  86. * well be changed to a spin_lock)
  87. * - A spin lock to protect the registry of kernel/driver users (reg.c)
  88. * - A global spin_lock (tipc_port_lock), which only task is to ensure
  89. * consistency where more than one port is involved in an operation,
  90. * i.e., whe a port is part of a linked list of ports.
  91. * There are two such lists; 'port_list', which is used for management,
  92. * and 'wait_list', which is used to queue ports during congestion.
  93. *
  94. * 4: The name table (name_table.c, name_distr.c, subscription.c)
  95. * - There is one big read/write-lock (tipc_nametbl_lock) protecting the
  96. * overall name table structure. Nothing must be added/removed to
  97. * this structure without holding write access to it.
  98. * - There is one local spin_lock per sub_sequence, which can be seen
  99. * as a sub-domain to the tipc_nametbl_lock domain. It is used only
  100. * for translation operations, and is needed because a translation
  101. * steps the root of the 'publication' linked list between each lookup.
  102. * This is always used within the scope of a tipc_nametbl_lock(read).
  103. * - A local spin_lock protecting the queue of subscriber events.
  104. */
  105. struct tipc_net_work {
  106. struct work_struct work;
  107. struct net *net;
  108. u32 addr;
  109. };
  110. static void tipc_net_finalize(struct net *net, u32 addr);
  111. int tipc_net_init(struct net *net, u8 *node_id, u32 addr)
  112. {
  113. if (tipc_own_id(net)) {
  114. pr_info("Cannot configure node identity twice\n");
  115. return -1;
  116. }
  117. pr_info("Started in network mode\n");
  118. if (node_id)
  119. tipc_set_node_id(net, node_id);
  120. if (addr)
  121. tipc_net_finalize(net, addr);
  122. return 0;
  123. }
  124. static void tipc_net_finalize(struct net *net, u32 addr)
  125. {
  126. struct tipc_net *tn = tipc_net(net);
  127. if (cmpxchg(&tn->node_addr, 0, addr))
  128. return;
  129. tipc_set_node_addr(net, addr);
  130. tipc_named_reinit(net);
  131. tipc_sk_reinit(net);
  132. tipc_mon_reinit_self(net);
  133. tipc_nametbl_publish(net, TIPC_CFG_SRV, addr, addr,
  134. TIPC_CLUSTER_SCOPE, 0, addr);
  135. }
  136. static void tipc_net_finalize_work(struct work_struct *work)
  137. {
  138. struct tipc_net_work *fwork;
  139. fwork = container_of(work, struct tipc_net_work, work);
  140. tipc_net_finalize(fwork->net, fwork->addr);
  141. kfree(fwork);
  142. }
  143. void tipc_sched_net_finalize(struct net *net, u32 addr)
  144. {
  145. struct tipc_net_work *fwork = kzalloc(sizeof(*fwork), GFP_ATOMIC);
  146. if (!fwork)
  147. return;
  148. INIT_WORK(&fwork->work, tipc_net_finalize_work);
  149. fwork->net = net;
  150. fwork->addr = addr;
  151. schedule_work(&fwork->work);
  152. }
  153. void tipc_net_stop(struct net *net)
  154. {
  155. if (!tipc_own_id(net))
  156. return;
  157. rtnl_lock();
  158. tipc_bearer_stop(net);
  159. tipc_node_stop(net);
  160. rtnl_unlock();
  161. pr_info("Left network mode\n");
  162. }
  163. static int __tipc_nl_add_net(struct net *net, struct tipc_nl_msg *msg)
  164. {
  165. struct tipc_net *tn = net_generic(net, tipc_net_id);
  166. u64 *w0 = (u64 *)&tn->node_id[0];
  167. u64 *w1 = (u64 *)&tn->node_id[8];
  168. struct nlattr *attrs;
  169. void *hdr;
  170. hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
  171. NLM_F_MULTI, TIPC_NL_NET_GET);
  172. if (!hdr)
  173. return -EMSGSIZE;
  174. attrs = nla_nest_start(msg->skb, TIPC_NLA_NET);
  175. if (!attrs)
  176. goto msg_full;
  177. if (nla_put_u32(msg->skb, TIPC_NLA_NET_ID, tn->net_id))
  178. goto attr_msg_full;
  179. if (nla_put_u64_64bit(msg->skb, TIPC_NLA_NET_NODEID, *w0, 0))
  180. goto attr_msg_full;
  181. if (nla_put_u64_64bit(msg->skb, TIPC_NLA_NET_NODEID_W1, *w1, 0))
  182. goto attr_msg_full;
  183. nla_nest_end(msg->skb, attrs);
  184. genlmsg_end(msg->skb, hdr);
  185. return 0;
  186. attr_msg_full:
  187. nla_nest_cancel(msg->skb, attrs);
  188. msg_full:
  189. genlmsg_cancel(msg->skb, hdr);
  190. return -EMSGSIZE;
  191. }
  192. int tipc_nl_net_dump(struct sk_buff *skb, struct netlink_callback *cb)
  193. {
  194. struct net *net = sock_net(skb->sk);
  195. int err;
  196. int done = cb->args[0];
  197. struct tipc_nl_msg msg;
  198. if (done)
  199. return 0;
  200. msg.skb = skb;
  201. msg.portid = NETLINK_CB(cb->skb).portid;
  202. msg.seq = cb->nlh->nlmsg_seq;
  203. err = __tipc_nl_add_net(net, &msg);
  204. if (err)
  205. goto out;
  206. done = 1;
  207. out:
  208. cb->args[0] = done;
  209. return skb->len;
  210. }
  211. int __tipc_nl_net_set(struct sk_buff *skb, struct genl_info *info)
  212. {
  213. struct nlattr *attrs[TIPC_NLA_NET_MAX + 1];
  214. struct net *net = sock_net(skb->sk);
  215. struct tipc_net *tn = tipc_net(net);
  216. int err;
  217. if (!info->attrs[TIPC_NLA_NET])
  218. return -EINVAL;
  219. err = nla_parse_nested(attrs, TIPC_NLA_NET_MAX,
  220. info->attrs[TIPC_NLA_NET], tipc_nl_net_policy,
  221. info->extack);
  222. if (err)
  223. return err;
  224. /* Can't change net id once TIPC has joined a network */
  225. if (tipc_own_addr(net))
  226. return -EPERM;
  227. if (attrs[TIPC_NLA_NET_ID]) {
  228. u32 val;
  229. val = nla_get_u32(attrs[TIPC_NLA_NET_ID]);
  230. if (val < 1 || val > 9999)
  231. return -EINVAL;
  232. tn->net_id = val;
  233. }
  234. if (attrs[TIPC_NLA_NET_ADDR]) {
  235. u32 addr;
  236. addr = nla_get_u32(attrs[TIPC_NLA_NET_ADDR]);
  237. if (!addr)
  238. return -EINVAL;
  239. tn->legacy_addr_format = true;
  240. tipc_net_init(net, NULL, addr);
  241. }
  242. if (attrs[TIPC_NLA_NET_NODEID]) {
  243. u8 node_id[NODE_ID_LEN];
  244. u64 *w0 = (u64 *)&node_id[0];
  245. u64 *w1 = (u64 *)&node_id[8];
  246. if (!attrs[TIPC_NLA_NET_NODEID_W1])
  247. return -EINVAL;
  248. *w0 = nla_get_u64(attrs[TIPC_NLA_NET_NODEID]);
  249. *w1 = nla_get_u64(attrs[TIPC_NLA_NET_NODEID_W1]);
  250. tipc_net_init(net, node_id, 0);
  251. }
  252. return 0;
  253. }
  254. int tipc_nl_net_set(struct sk_buff *skb, struct genl_info *info)
  255. {
  256. int err;
  257. rtnl_lock();
  258. err = __tipc_nl_net_set(skb, info);
  259. rtnl_unlock();
  260. return err;
  261. }