br_stp_if.c 5.9 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 1.1.1.1 2007/06/12 07:27:14 eyryu 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_ifinfo_notify(RTM_NEWLINK, p);
  75. br_port_state_selection(p->br);
  76. }
  77. /* called under bridge lock */
  78. void br_stp_disable_port(struct net_bridge_port *p)
  79. {
  80. struct net_bridge *br;
  81. int wasroot;
  82. br = p->br;
  83. printk(KERN_INFO "%s: port %i(%s) entering %s state\n",
  84. br->dev->name, p->port_no, p->dev->name, "disabled");
  85. br_ifinfo_notify(RTM_DELLINK, p);
  86. wasroot = br_is_root_bridge(br);
  87. br_become_designated_port(p);
  88. p->state = BR_STATE_DISABLED;
  89. p->topology_change_ack = 0;
  90. p->config_pending = 0;
  91. del_timer(&p->message_age_timer);
  92. del_timer(&p->forward_delay_timer);
  93. del_timer(&p->hold_timer);
  94. br_fdb_delete_by_port(br, p, 0);
  95. br_configuration_update(br);
  96. br_port_state_selection(br);
  97. if (br_is_root_bridge(br) && !wasroot)
  98. br_become_root_bridge(br);
  99. }
  100. /* called under bridge lock */
  101. void br_stp_change_bridge_id(struct net_bridge *br, const unsigned char *addr)
  102. {
  103. /* should be aligned on 2 bytes for compare_ether_addr() */
  104. unsigned short oldaddr_aligned[ETH_ALEN >> 1];
  105. unsigned char *oldaddr = (unsigned char *)oldaddr_aligned;
  106. struct net_bridge_port *p;
  107. int wasroot;
  108. wasroot = br_is_root_bridge(br);
  109. memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN);
  110. memcpy(br->bridge_id.addr, addr, ETH_ALEN);
  111. memcpy(br->dev->dev_addr, addr, ETH_ALEN);
  112. list_for_each_entry(p, &br->port_list, list) {
  113. if (!compare_ether_addr(p->designated_bridge.addr, oldaddr))
  114. memcpy(p->designated_bridge.addr, addr, ETH_ALEN);
  115. if (!compare_ether_addr(p->designated_root.addr, oldaddr))
  116. memcpy(p->designated_root.addr, addr, ETH_ALEN);
  117. }
  118. br_configuration_update(br);
  119. br_port_state_selection(br);
  120. if (br_is_root_bridge(br) && !wasroot)
  121. br_become_root_bridge(br);
  122. }
  123. /* should be aligned on 2 bytes for compare_ether_addr() */
  124. static const unsigned short br_mac_zero_aligned[ETH_ALEN >> 1];
  125. /* called under bridge lock */
  126. void br_stp_recalculate_bridge_id(struct net_bridge *br)
  127. {
  128. const unsigned char *br_mac_zero =
  129. (const unsigned char *)br_mac_zero_aligned;
  130. const unsigned char *addr = br_mac_zero;
  131. struct net_bridge_port *p;
  132. list_for_each_entry(p, &br->port_list, list) {
  133. if (addr == br_mac_zero ||
  134. memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0)
  135. addr = p->dev->dev_addr;
  136. }
  137. if (compare_ether_addr(br->bridge_id.addr, addr))
  138. br_stp_change_bridge_id(br, addr);
  139. }
  140. /* called under bridge lock */
  141. void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio)
  142. {
  143. struct net_bridge_port *p;
  144. int wasroot;
  145. wasroot = br_is_root_bridge(br);
  146. list_for_each_entry(p, &br->port_list, list) {
  147. if (p->state != BR_STATE_DISABLED &&
  148. br_is_designated_port(p)) {
  149. p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF;
  150. p->designated_bridge.prio[1] = newprio & 0xFF;
  151. }
  152. }
  153. br->bridge_id.prio[0] = (newprio >> 8) & 0xFF;
  154. br->bridge_id.prio[1] = newprio & 0xFF;
  155. br_configuration_update(br);
  156. br_port_state_selection(br);
  157. if (br_is_root_bridge(br) && !wasroot)
  158. br_become_root_bridge(br);
  159. }
  160. /* called under bridge lock */
  161. void br_stp_set_port_priority(struct net_bridge_port *p, u8 newprio)
  162. {
  163. port_id new_port_id = br_make_port_id(newprio, p->port_no);
  164. if (br_is_designated_port(p))
  165. p->designated_port = new_port_id;
  166. p->port_id = new_port_id;
  167. p->priority = newprio;
  168. if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) &&
  169. p->port_id < p->designated_port) {
  170. br_become_designated_port(p);
  171. br_port_state_selection(p->br);
  172. }
  173. }
  174. /* called under bridge lock */
  175. void br_stp_set_path_cost(struct net_bridge_port *p, u32 path_cost)
  176. {
  177. p->path_cost = path_cost;
  178. br_configuration_update(p->br);
  179. br_port_state_selection(p->br);
  180. }
  181. ssize_t br_show_bridge_id(char *buf, const struct bridge_id *id)
  182. {
  183. return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
  184. id->prio[0], id->prio[1],
  185. id->addr[0], id->addr[1], id->addr[2],
  186. id->addr[3], id->addr[4], id->addr[5]);
  187. }