eth_media.c 8.4 KB

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  1. /*
  2. * net/tipc/eth_media.c: Ethernet bearer support for TIPC
  3. *
  4. * Copyright (c) 2001-2006, Ericsson AB
  5. * Copyright (c) 2005-2006, 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 <net/tipc/tipc.h>
  37. #include <net/tipc/tipc_bearer.h>
  38. #include <net/tipc/tipc_msg.h>
  39. #include <linux/netdevice.h>
  40. #define MAX_ETH_BEARERS 2
  41. #define ETH_LINK_PRIORITY TIPC_DEF_LINK_PRI
  42. #define ETH_LINK_TOLERANCE TIPC_DEF_LINK_TOL
  43. #define ETH_LINK_WINDOW TIPC_DEF_LINK_WIN
  44. /**
  45. * struct eth_bearer - Ethernet bearer data structure
  46. * @bearer: ptr to associated "generic" bearer structure
  47. * @dev: ptr to associated Ethernet network device
  48. * @tipc_packet_type: used in binding TIPC to Ethernet driver
  49. */
  50. struct eth_bearer {
  51. struct tipc_bearer *bearer;
  52. struct net_device *dev;
  53. struct packet_type tipc_packet_type;
  54. };
  55. static struct eth_bearer eth_bearers[MAX_ETH_BEARERS];
  56. static int eth_started = 0;
  57. static struct notifier_block notifier;
  58. /**
  59. * send_msg - send a TIPC message out over an Ethernet interface
  60. */
  61. static int send_msg(struct sk_buff *buf, struct tipc_bearer *tb_ptr,
  62. struct tipc_media_addr *dest)
  63. {
  64. struct sk_buff *clone;
  65. struct net_device *dev;
  66. clone = skb_clone(buf, GFP_ATOMIC);
  67. if (clone) {
  68. clone->nh.raw = clone->data;
  69. dev = ((struct eth_bearer *)(tb_ptr->usr_handle))->dev;
  70. clone->dev = dev;
  71. dev->hard_header(clone, dev, ETH_P_TIPC,
  72. &dest->dev_addr.eth_addr,
  73. dev->dev_addr, clone->len);
  74. dev_queue_xmit(clone);
  75. }
  76. return TIPC_OK;
  77. }
  78. /**
  79. * recv_msg - handle incoming TIPC message from an Ethernet interface
  80. *
  81. * Routine truncates any Ethernet padding/CRC appended to the message,
  82. * and ensures message size matches actual length
  83. */
  84. static int recv_msg(struct sk_buff *buf, struct net_device *dev,
  85. struct packet_type *pt, struct net_device *orig_dev)
  86. {
  87. struct eth_bearer *eb_ptr = (struct eth_bearer *)pt->af_packet_priv;
  88. u32 size;
  89. if (likely(eb_ptr->bearer)) {
  90. if (likely(!dev->promiscuity) ||
  91. !memcmp(buf->mac.raw,dev->dev_addr,ETH_ALEN) ||
  92. !memcmp(buf->mac.raw,dev->broadcast,ETH_ALEN)) {
  93. size = msg_size((struct tipc_msg *)buf->data);
  94. skb_trim(buf, size);
  95. if (likely(buf->len == size)) {
  96. buf->next = NULL;
  97. tipc_recv_msg(buf, eb_ptr->bearer);
  98. return TIPC_OK;
  99. }
  100. }
  101. }
  102. kfree_skb(buf);
  103. return TIPC_OK;
  104. }
  105. /**
  106. * enable_bearer - attach TIPC bearer to an Ethernet interface
  107. */
  108. static int enable_bearer(struct tipc_bearer *tb_ptr)
  109. {
  110. struct net_device *dev = dev_base;
  111. struct eth_bearer *eb_ptr = &eth_bearers[0];
  112. struct eth_bearer *stop = &eth_bearers[MAX_ETH_BEARERS];
  113. char *driver_name = strchr((const char *)tb_ptr->name, ':') + 1;
  114. /* Find device with specified name */
  115. while (dev && dev->name && strncmp(dev->name, driver_name, IFNAMSIZ)) {
  116. dev = dev->next;
  117. }
  118. if (!dev)
  119. return -ENODEV;
  120. /* Find Ethernet bearer for device (or create one) */
  121. for (;(eb_ptr != stop) && eb_ptr->dev && (eb_ptr->dev != dev); eb_ptr++);
  122. if (eb_ptr == stop)
  123. return -EDQUOT;
  124. if (!eb_ptr->dev) {
  125. eb_ptr->dev = dev;
  126. eb_ptr->tipc_packet_type.type = __constant_htons(ETH_P_TIPC);
  127. eb_ptr->tipc_packet_type.dev = dev;
  128. eb_ptr->tipc_packet_type.func = recv_msg;
  129. eb_ptr->tipc_packet_type.af_packet_priv = eb_ptr;
  130. INIT_LIST_HEAD(&(eb_ptr->tipc_packet_type.list));
  131. dev_hold(dev);
  132. dev_add_pack(&eb_ptr->tipc_packet_type);
  133. }
  134. /* Associate TIPC bearer with Ethernet bearer */
  135. eb_ptr->bearer = tb_ptr;
  136. tb_ptr->usr_handle = (void *)eb_ptr;
  137. tb_ptr->mtu = dev->mtu;
  138. tb_ptr->blocked = 0;
  139. tb_ptr->addr.type = htonl(TIPC_MEDIA_TYPE_ETH);
  140. memcpy(&tb_ptr->addr.dev_addr, &dev->dev_addr, ETH_ALEN);
  141. return 0;
  142. }
  143. /**
  144. * disable_bearer - detach TIPC bearer from an Ethernet interface
  145. *
  146. * We really should do dev_remove_pack() here, but this function can not be
  147. * called at tasklet level. => Use eth_bearer->bearer as a flag to throw away
  148. * incoming buffers, & postpone dev_remove_pack() to eth_media_stop() on exit.
  149. */
  150. static void disable_bearer(struct tipc_bearer *tb_ptr)
  151. {
  152. ((struct eth_bearer *)tb_ptr->usr_handle)->bearer = NULL;
  153. }
  154. /**
  155. * recv_notification - handle device updates from OS
  156. *
  157. * Change the state of the Ethernet bearer (if any) associated with the
  158. * specified device.
  159. */
  160. static int recv_notification(struct notifier_block *nb, unsigned long evt,
  161. void *dv)
  162. {
  163. struct net_device *dev = (struct net_device *)dv;
  164. struct eth_bearer *eb_ptr = &eth_bearers[0];
  165. struct eth_bearer *stop = &eth_bearers[MAX_ETH_BEARERS];
  166. while ((eb_ptr->dev != dev)) {
  167. if (++eb_ptr == stop)
  168. return NOTIFY_DONE; /* couldn't find device */
  169. }
  170. if (!eb_ptr->bearer)
  171. return NOTIFY_DONE; /* bearer had been disabled */
  172. eb_ptr->bearer->mtu = dev->mtu;
  173. switch (evt) {
  174. case NETDEV_CHANGE:
  175. if (netif_carrier_ok(dev))
  176. tipc_continue(eb_ptr->bearer);
  177. else
  178. tipc_block_bearer(eb_ptr->bearer->name);
  179. break;
  180. case NETDEV_UP:
  181. tipc_continue(eb_ptr->bearer);
  182. break;
  183. case NETDEV_DOWN:
  184. tipc_block_bearer(eb_ptr->bearer->name);
  185. break;
  186. case NETDEV_CHANGEMTU:
  187. case NETDEV_CHANGEADDR:
  188. tipc_block_bearer(eb_ptr->bearer->name);
  189. tipc_continue(eb_ptr->bearer);
  190. break;
  191. case NETDEV_UNREGISTER:
  192. case NETDEV_CHANGENAME:
  193. tipc_disable_bearer(eb_ptr->bearer->name);
  194. break;
  195. }
  196. return NOTIFY_OK;
  197. }
  198. /**
  199. * eth_addr2str - convert Ethernet address to string
  200. */
  201. static char *eth_addr2str(struct tipc_media_addr *a, char *str_buf, int str_size)
  202. {
  203. unchar *addr = (unchar *)&a->dev_addr;
  204. if (str_size < 18)
  205. *str_buf = '\0';
  206. else
  207. sprintf(str_buf, "%02x:%02x:%02x:%02x:%02x:%02x",
  208. addr[0], addr[1], addr[2], addr[3], addr[4], addr[5]);
  209. return str_buf;
  210. }
  211. /**
  212. * tipc_eth_media_start - activate Ethernet bearer support
  213. *
  214. * Register Ethernet media type with TIPC bearer code. Also register
  215. * with OS for notifications about device state changes.
  216. */
  217. int tipc_eth_media_start(void)
  218. {
  219. struct tipc_media_addr bcast_addr;
  220. int res;
  221. if (eth_started)
  222. return -EINVAL;
  223. bcast_addr.type = htonl(TIPC_MEDIA_TYPE_ETH);
  224. memset(&bcast_addr.dev_addr, 0xff, ETH_ALEN);
  225. memset(eth_bearers, 0, sizeof(eth_bearers));
  226. res = tipc_register_media(TIPC_MEDIA_TYPE_ETH, "eth",
  227. enable_bearer, disable_bearer, send_msg,
  228. eth_addr2str, &bcast_addr, ETH_LINK_PRIORITY,
  229. ETH_LINK_TOLERANCE, ETH_LINK_WINDOW);
  230. if (res)
  231. return res;
  232. notifier.notifier_call = &recv_notification;
  233. notifier.priority = 0;
  234. res = register_netdevice_notifier(&notifier);
  235. if (!res)
  236. eth_started = 1;
  237. return res;
  238. }
  239. /**
  240. * tipc_eth_media_stop - deactivate Ethernet bearer support
  241. */
  242. void tipc_eth_media_stop(void)
  243. {
  244. int i;
  245. if (!eth_started)
  246. return;
  247. unregister_netdevice_notifier(&notifier);
  248. for (i = 0; i < MAX_ETH_BEARERS ; i++) {
  249. if (eth_bearers[i].bearer) {
  250. eth_bearers[i].bearer->blocked = 1;
  251. eth_bearers[i].bearer = NULL;
  252. }
  253. if (eth_bearers[i].dev) {
  254. dev_remove_pack(&eth_bearers[i].tipc_packet_type);
  255. dev_put(eth_bearers[i].dev);
  256. }
  257. }
  258. memset(&eth_bearers, 0, sizeof(eth_bearers));
  259. eth_started = 0;
  260. }