net.c 9.7 KB

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  1. /*
  2. * net/tipc/net.c: TIPC network routing code
  3. *
  4. * Copyright (c) 1995-2006, Ericsson AB
  5. * Copyright (c) 2005, 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 "bearer.h"
  38. #include "net.h"
  39. #include "zone.h"
  40. #include "addr.h"
  41. #include "name_table.h"
  42. #include "name_distr.h"
  43. #include "subscr.h"
  44. #include "link.h"
  45. #include "msg.h"
  46. #include "port.h"
  47. #include "bcast.h"
  48. #include "discover.h"
  49. #include "config.h"
  50. /*
  51. * The TIPC locking policy is designed to ensure a very fine locking
  52. * granularity, permitting complete parallel access to individual
  53. * port and node/link instances. The code consists of three major
  54. * locking domains, each protected with their own disjunct set of locks.
  55. *
  56. * 1: The routing hierarchy.
  57. * Comprises the structures 'zone', 'cluster', 'node', 'link'
  58. * and 'bearer'. The whole hierarchy is protected by a big
  59. * read/write lock, tipc_net_lock, to enssure that nothing is added
  60. * or removed while code is accessing any of these structures.
  61. * This layer must not be called from the two others while they
  62. * hold any of their own locks.
  63. * Neither must it itself do any upcalls to the other two before
  64. * it has released tipc_net_lock and other protective locks.
  65. *
  66. * Within the tipc_net_lock domain there are two sub-domains;'node' and
  67. * 'bearer', where local write operations are permitted,
  68. * provided that those are protected by individual spin_locks
  69. * per instance. Code holding tipc_net_lock(read) and a node spin_lock
  70. * is permitted to poke around in both the node itself and its
  71. * subordinate links. I.e, it can update link counters and queues,
  72. * change link state, send protocol messages, and alter the
  73. * "active_links" array in the node; but it can _not_ remove a link
  74. * or a node from the overall structure.
  75. * Correspondingly, individual bearers may change status within a
  76. * tipc_net_lock(read), protected by an individual spin_lock ber bearer
  77. * instance, but it needs tipc_net_lock(write) to remove/add any bearers.
  78. *
  79. *
  80. * 2: The transport level of the protocol.
  81. * This consists of the structures port, (and its user level
  82. * representations, such as user_port and tipc_sock), reference and
  83. * tipc_user (port.c, reg.c, socket.c).
  84. *
  85. * This layer has four different locks:
  86. * - The tipc_port spin_lock. This is protecting each port instance
  87. * from parallel data access and removal. Since we can not place
  88. * this lock in the port itself, it has been placed in the
  89. * corresponding reference table entry, which has the same life
  90. * cycle as the module. This entry is difficult to access from
  91. * outside the TIPC core, however, so a pointer to the lock has
  92. * been added in the port instance, -to be used for unlocking
  93. * only.
  94. * - A read/write lock to protect the reference table itself (teg.c).
  95. * (Nobody is using read-only access to this, so it can just as
  96. * well be changed to a spin_lock)
  97. * - A spin lock to protect the registry of kernel/driver users (reg.c)
  98. * - A global spin_lock (tipc_port_lock), which only task is to ensure
  99. * consistency where more than one port is involved in an operation,
  100. * i.e., whe a port is part of a linked list of ports.
  101. * There are two such lists; 'port_list', which is used for management,
  102. * and 'wait_list', which is used to queue ports during congestion.
  103. *
  104. * 3: The name table (name_table.c, name_distr.c, subscription.c)
  105. * - There is one big read/write-lock (tipc_nametbl_lock) protecting the
  106. * overall name table structure. Nothing must be added/removed to
  107. * this structure without holding write access to it.
  108. * - There is one local spin_lock per sub_sequence, which can be seen
  109. * as a sub-domain to the tipc_nametbl_lock domain. It is used only
  110. * for translation operations, and is needed because a translation
  111. * steps the root of the 'publication' linked list between each lookup.
  112. * This is always used within the scope of a tipc_nametbl_lock(read).
  113. * - A local spin_lock protecting the queue of subscriber events.
  114. */
  115. DEFINE_RWLOCK(tipc_net_lock);
  116. struct network tipc_net = { NULL };
  117. struct node *tipc_net_select_remote_node(u32 addr, u32 ref)
  118. {
  119. return tipc_zone_select_remote_node(tipc_net.zones[tipc_zone(addr)], addr, ref);
  120. }
  121. u32 tipc_net_select_router(u32 addr, u32 ref)
  122. {
  123. return tipc_zone_select_router(tipc_net.zones[tipc_zone(addr)], addr, ref);
  124. }
  125. #if 0
  126. u32 tipc_net_next_node(u32 a)
  127. {
  128. if (tipc_net.zones[tipc_zone(a)])
  129. return tipc_zone_next_node(a);
  130. return 0;
  131. }
  132. #endif
  133. void tipc_net_remove_as_router(u32 router)
  134. {
  135. u32 z_num;
  136. for (z_num = 1; z_num <= tipc_max_zones; z_num++) {
  137. if (!tipc_net.zones[z_num])
  138. continue;
  139. tipc_zone_remove_as_router(tipc_net.zones[z_num], router);
  140. }
  141. }
  142. void tipc_net_send_external_routes(u32 dest)
  143. {
  144. u32 z_num;
  145. for (z_num = 1; z_num <= tipc_max_zones; z_num++) {
  146. if (tipc_net.zones[z_num])
  147. tipc_zone_send_external_routes(tipc_net.zones[z_num], dest);
  148. }
  149. }
  150. static int net_init(void)
  151. {
  152. memset(&tipc_net, 0, sizeof(tipc_net));
  153. tipc_net.zones = kcalloc(tipc_max_zones + 1, sizeof(struct _zone *), GFP_ATOMIC);
  154. if (!tipc_net.zones) {
  155. return -ENOMEM;
  156. }
  157. return TIPC_OK;
  158. }
  159. static void net_stop(void)
  160. {
  161. u32 z_num;
  162. if (!tipc_net.zones)
  163. return;
  164. for (z_num = 1; z_num <= tipc_max_zones; z_num++) {
  165. tipc_zone_delete(tipc_net.zones[z_num]);
  166. }
  167. kfree(tipc_net.zones);
  168. tipc_net.zones = NULL;
  169. }
  170. static void net_route_named_msg(struct sk_buff *buf)
  171. {
  172. struct tipc_msg *msg = buf_msg(buf);
  173. u32 dnode;
  174. u32 dport;
  175. if (!msg_named(msg)) {
  176. msg_dbg(msg, "tipc_net->drop_nam:");
  177. buf_discard(buf);
  178. return;
  179. }
  180. dnode = addr_domain(msg_lookup_scope(msg));
  181. dport = tipc_nametbl_translate(msg_nametype(msg), msg_nameinst(msg), &dnode);
  182. dbg("tipc_net->lookup<%u,%u>-><%u,%x>\n",
  183. msg_nametype(msg), msg_nameinst(msg), dport, dnode);
  184. if (dport) {
  185. msg_set_destnode(msg, dnode);
  186. msg_set_destport(msg, dport);
  187. tipc_net_route_msg(buf);
  188. return;
  189. }
  190. msg_dbg(msg, "tipc_net->rej:NO NAME: ");
  191. tipc_reject_msg(buf, TIPC_ERR_NO_NAME);
  192. }
  193. void tipc_net_route_msg(struct sk_buff *buf)
  194. {
  195. struct tipc_msg *msg;
  196. u32 dnode;
  197. if (!buf)
  198. return;
  199. msg = buf_msg(buf);
  200. msg_incr_reroute_cnt(msg);
  201. if (msg_reroute_cnt(msg) > 6) {
  202. if (msg_errcode(msg)) {
  203. msg_dbg(msg, "NET>DISC>:");
  204. buf_discard(buf);
  205. } else {
  206. msg_dbg(msg, "NET>REJ>:");
  207. tipc_reject_msg(buf, msg_destport(msg) ?
  208. TIPC_ERR_NO_PORT : TIPC_ERR_NO_NAME);
  209. }
  210. return;
  211. }
  212. msg_dbg(msg, "tipc_net->rout: ");
  213. /* Handle message for this node */
  214. dnode = msg_short(msg) ? tipc_own_addr : msg_destnode(msg);
  215. if (in_scope(dnode, tipc_own_addr)) {
  216. if (msg_isdata(msg)) {
  217. if (msg_mcast(msg))
  218. tipc_port_recv_mcast(buf, NULL);
  219. else if (msg_destport(msg))
  220. tipc_port_recv_msg(buf);
  221. else
  222. net_route_named_msg(buf);
  223. return;
  224. }
  225. switch (msg_user(msg)) {
  226. case ROUTE_DISTRIBUTOR:
  227. tipc_cltr_recv_routing_table(buf);
  228. break;
  229. case NAME_DISTRIBUTOR:
  230. tipc_named_recv(buf);
  231. break;
  232. case CONN_MANAGER:
  233. tipc_port_recv_proto_msg(buf);
  234. break;
  235. default:
  236. msg_dbg(msg,"DROP/NET/<REC<");
  237. buf_discard(buf);
  238. }
  239. return;
  240. }
  241. /* Handle message for another node */
  242. msg_dbg(msg, "NET>SEND>: ");
  243. tipc_link_send(buf, dnode, msg_link_selector(msg));
  244. }
  245. int tipc_net_start(void)
  246. {
  247. char addr_string[16];
  248. int res;
  249. if (tipc_mode != TIPC_NODE_MODE)
  250. return -ENOPROTOOPT;
  251. tipc_mode = TIPC_NET_MODE;
  252. tipc_named_reinit();
  253. tipc_port_reinit();
  254. if ((res = tipc_bearer_init()) ||
  255. (res = net_init()) ||
  256. (res = tipc_cltr_init()) ||
  257. (res = tipc_bclink_init())) {
  258. return res;
  259. }
  260. tipc_subscr_stop();
  261. tipc_cfg_stop();
  262. tipc_k_signal((Handler)tipc_subscr_start, 0);
  263. tipc_k_signal((Handler)tipc_cfg_init, 0);
  264. info("Started in network mode\n");
  265. info("Own node address %s, network identity %u\n",
  266. addr_string_fill(addr_string, tipc_own_addr), tipc_net_id);
  267. return TIPC_OK;
  268. }
  269. void tipc_net_stop(void)
  270. {
  271. if (tipc_mode != TIPC_NET_MODE)
  272. return;
  273. write_lock_bh(&tipc_net_lock);
  274. tipc_bearer_stop();
  275. tipc_mode = TIPC_NODE_MODE;
  276. tipc_bclink_stop();
  277. net_stop();
  278. write_unlock_bh(&tipc_net_lock);
  279. info("Left network mode \n");
  280. }