br_stp_if.c 7.2 KB

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  1. /*
  2. * Spanning tree protocol; interface code
  3. * Linux ethernet bridge
  4. *
  5. * Authors:
  6. * Lennert Buytenhek <buytenh@gnu.org>
  7. *
  8. * $Id: br_stp_if.c,v 1.4 2001/04/14 21:14:39 davem Exp $
  9. *
  10. * This program is free software; you can redistribute it and/or
  11. * modify it under the terms of the GNU General Public License
  12. * as published by the Free Software Foundation; either version
  13. * 2 of the License, or (at your option) any later version.
  14. */
  15. #include <linux/kernel.h>
  16. #include <linux/smp_lock.h>
  17. #include <linux/etherdevice.h>
  18. #include <linux/rtnetlink.h>
  19. #include "br_private.h"
  20. #include "br_private_stp.h"
  21. /* Port id is composed of priority and port number.
  22. * NB: least significant bits of priority are dropped to
  23. * make room for more ports.
  24. */
  25. static inline port_id br_make_port_id(__u8 priority, __u16 port_no)
  26. {
  27. return ((u16)priority << BR_PORT_BITS)
  28. | (port_no & ((1<<BR_PORT_BITS)-1));
  29. }
  30. /* called under bridge lock */
  31. void br_init_port(struct net_bridge_port *p)
  32. {
  33. p->port_id = br_make_port_id(p->priority, p->port_no);
  34. br_become_designated_port(p);
  35. p->state = BR_STATE_BLOCKING;
  36. p->topology_change_ack = 0;
  37. p->config_pending = 0;
  38. }
  39. /* called under bridge lock */
  40. void br_stp_enable_bridge(struct net_bridge *br)
  41. {
  42. struct net_bridge_port *p;
  43. spin_lock_bh(&br->lock);
  44. mod_timer(&br->hello_timer, jiffies + br->hello_time);
  45. mod_timer(&br->gc_timer, jiffies + HZ/10);
  46. br_config_bpdu_generation(br);
  47. list_for_each_entry(p, &br->port_list, list) {
  48. if ((p->dev->flags & IFF_UP) && netif_carrier_ok(p->dev))
  49. br_stp_enable_port(p);
  50. }
  51. spin_unlock_bh(&br->lock);
  52. }
  53. /* NO locks held */
  54. void br_stp_disable_bridge(struct net_bridge *br)
  55. {
  56. struct net_bridge_port *p;
  57. spin_lock_bh(&br->lock);
  58. list_for_each_entry(p, &br->port_list, list) {
  59. if (p->state != BR_STATE_DISABLED)
  60. br_stp_disable_port(p);
  61. }
  62. br->topology_change = 0;
  63. br->topology_change_detected = 0;
  64. spin_unlock_bh(&br->lock);
  65. del_timer_sync(&br->hello_timer);
  66. del_timer_sync(&br->topology_change_timer);
  67. del_timer_sync(&br->tcn_timer);
  68. del_timer_sync(&br->gc_timer);
  69. }
  70. /* called under bridge lock */
  71. void br_stp_enable_port(struct net_bridge_port *p)
  72. {
  73. br_init_port(p);
  74. br_port_state_selection(p->br);
  75. }
  76. /* called under bridge lock */
  77. void br_stp_disable_port(struct net_bridge_port *p)
  78. {
  79. struct net_bridge *br;
  80. int wasroot;
  81. br = p->br;
  82. printk(KERN_INFO "%s: port %i(%s) entering %s state\n",
  83. br->dev->name, p->port_no, p->dev->name, "disabled");
  84. wasroot = br_is_root_bridge(br);
  85. br_become_designated_port(p);
  86. p->state = BR_STATE_DISABLED;
  87. p->topology_change_ack = 0;
  88. p->config_pending = 0;
  89. del_timer(&p->message_age_timer);
  90. del_timer(&p->forward_delay_timer);
  91. del_timer(&p->hold_timer);
  92. br_fdb_delete_by_port(br, p, 0);
  93. br_configuration_update(br);
  94. br_port_state_selection(br);
  95. if (br_is_root_bridge(br) && !wasroot)
  96. br_become_root_bridge(br);
  97. }
  98. static void br_stp_start(struct net_bridge *br)
  99. {
  100. int r;
  101. char *argv[] = { BR_STP_PROG, br->dev->name, "start", NULL };
  102. char *envp[] = { NULL };
  103. r = call_usermodehelper(BR_STP_PROG, argv, envp, 1);
  104. if (r == 0) {
  105. br->stp_enabled = BR_USER_STP;
  106. printk(KERN_INFO "%s: userspace STP started\n", br->dev->name);
  107. } else {
  108. br->stp_enabled = BR_KERNEL_STP;
  109. printk(KERN_INFO "%s: starting userspace STP failed, "
  110. "staring kernel STP\n", br->dev->name);
  111. /* To start timers on any ports left in blocking */
  112. spin_lock_bh(&br->lock);
  113. br_port_state_selection(br);
  114. spin_unlock_bh(&br->lock);
  115. }
  116. }
  117. static void br_stp_stop(struct net_bridge *br)
  118. {
  119. int r;
  120. char *argv[] = { BR_STP_PROG, br->dev->name, "stop", NULL };
  121. char *envp[] = { NULL };
  122. if (br->stp_enabled == BR_USER_STP) {
  123. r = call_usermodehelper(BR_STP_PROG, argv, envp, 1);
  124. printk(KERN_INFO "%s: userspace STP stopped, return code %d\n",
  125. br->dev->name, r);
  126. /* To start timers on any ports left in blocking */
  127. spin_lock_bh(&br->lock);
  128. br_port_state_selection(br);
  129. spin_unlock_bh(&br->lock);
  130. }
  131. br->stp_enabled = BR_NO_STP;
  132. }
  133. void br_stp_set_enabled(struct net_bridge *br, unsigned long val)
  134. {
  135. ASSERT_RTNL();
  136. if (val) {
  137. if (br->stp_enabled == BR_NO_STP)
  138. br_stp_start(br);
  139. } else {
  140. if (br->stp_enabled != BR_NO_STP)
  141. br_stp_stop(br);
  142. }
  143. }
  144. /* called under bridge lock */
  145. void br_stp_change_bridge_id(struct net_bridge *br, const unsigned char *addr)
  146. {
  147. /* should be aligned on 2 bytes for compare_ether_addr() */
  148. unsigned short oldaddr_aligned[ETH_ALEN >> 1];
  149. unsigned char *oldaddr = (unsigned char *)oldaddr_aligned;
  150. struct net_bridge_port *p;
  151. int wasroot;
  152. wasroot = br_is_root_bridge(br);
  153. memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN);
  154. memcpy(br->bridge_id.addr, addr, ETH_ALEN);
  155. memcpy(br->dev->dev_addr, addr, ETH_ALEN);
  156. list_for_each_entry(p, &br->port_list, list) {
  157. if (!compare_ether_addr(p->designated_bridge.addr, oldaddr))
  158. memcpy(p->designated_bridge.addr, addr, ETH_ALEN);
  159. if (!compare_ether_addr(p->designated_root.addr, oldaddr))
  160. memcpy(p->designated_root.addr, addr, ETH_ALEN);
  161. }
  162. br_configuration_update(br);
  163. br_port_state_selection(br);
  164. if (br_is_root_bridge(br) && !wasroot)
  165. br_become_root_bridge(br);
  166. }
  167. /* should be aligned on 2 bytes for compare_ether_addr() */
  168. static const unsigned short br_mac_zero_aligned[ETH_ALEN >> 1];
  169. /* called under bridge lock */
  170. void br_stp_recalculate_bridge_id(struct net_bridge *br)
  171. {
  172. const unsigned char *br_mac_zero =
  173. (const unsigned char *)br_mac_zero_aligned;
  174. const unsigned char *addr = br_mac_zero;
  175. struct net_bridge_port *p;
  176. list_for_each_entry(p, &br->port_list, list) {
  177. if (addr == br_mac_zero ||
  178. memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0)
  179. addr = p->dev->dev_addr;
  180. }
  181. if (compare_ether_addr(br->bridge_id.addr, addr))
  182. br_stp_change_bridge_id(br, addr);
  183. }
  184. /* called under bridge lock */
  185. void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio)
  186. {
  187. struct net_bridge_port *p;
  188. int wasroot;
  189. wasroot = br_is_root_bridge(br);
  190. list_for_each_entry(p, &br->port_list, list) {
  191. if (p->state != BR_STATE_DISABLED &&
  192. br_is_designated_port(p)) {
  193. p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF;
  194. p->designated_bridge.prio[1] = newprio & 0xFF;
  195. }
  196. }
  197. br->bridge_id.prio[0] = (newprio >> 8) & 0xFF;
  198. br->bridge_id.prio[1] = newprio & 0xFF;
  199. br_configuration_update(br);
  200. br_port_state_selection(br);
  201. if (br_is_root_bridge(br) && !wasroot)
  202. br_become_root_bridge(br);
  203. }
  204. /* called under bridge lock */
  205. void br_stp_set_port_priority(struct net_bridge_port *p, u8 newprio)
  206. {
  207. port_id new_port_id = br_make_port_id(newprio, p->port_no);
  208. if (br_is_designated_port(p))
  209. p->designated_port = new_port_id;
  210. p->port_id = new_port_id;
  211. p->priority = newprio;
  212. if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) &&
  213. p->port_id < p->designated_port) {
  214. br_become_designated_port(p);
  215. br_port_state_selection(p->br);
  216. }
  217. }
  218. /* called under bridge lock */
  219. void br_stp_set_path_cost(struct net_bridge_port *p, u32 path_cost)
  220. {
  221. p->path_cost = path_cost;
  222. br_configuration_update(p->br);
  223. br_port_state_selection(p->br);
  224. }
  225. ssize_t br_show_bridge_id(char *buf, const struct bridge_id *id)
  226. {
  227. return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
  228. id->prio[0], id->prio[1],
  229. id->addr[0], id->addr[1], id->addr[2],
  230. id->addr[3], id->addr[4], id->addr[5]);
  231. }