br_stp_timer.c 4.2 KB

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  1. // SPDX-License-Identifier: GPL-2.0-or-later
  2. /*
  3. * Spanning tree protocol; timer-related code
  4. * Linux ethernet bridge
  5. *
  6. * Authors:
  7. * Lennert Buytenhek <buytenh@gnu.org>
  8. */
  9. #include <linux/kernel.h>
  10. #include <linux/times.h>
  11. #include "br_private.h"
  12. #include "br_private_stp.h"
  13. /* called under bridge lock */
  14. static int br_is_designated_for_some_port(const struct net_bridge *br)
  15. {
  16. struct net_bridge_port *p;
  17. list_for_each_entry(p, &br->port_list, list) {
  18. if (p->state != BR_STATE_DISABLED &&
  19. !memcmp(&p->designated_bridge, &br->bridge_id, 8))
  20. return 1;
  21. }
  22. return 0;
  23. }
  24. static void br_hello_timer_expired(struct timer_list *t)
  25. {
  26. struct net_bridge *br = from_timer(br, t, hello_timer);
  27. br_debug(br, "hello timer expired\n");
  28. spin_lock(&br->lock);
  29. if (br->dev->flags & IFF_UP) {
  30. br_config_bpdu_generation(br);
  31. if (br->stp_enabled == BR_KERNEL_STP)
  32. mod_timer(&br->hello_timer,
  33. round_jiffies(jiffies + br->hello_time));
  34. }
  35. spin_unlock(&br->lock);
  36. }
  37. static void br_message_age_timer_expired(struct timer_list *t)
  38. {
  39. struct net_bridge_port *p = from_timer(p, t, message_age_timer);
  40. struct net_bridge *br = p->br;
  41. const bridge_id *id = &p->designated_bridge;
  42. int was_root;
  43. if (p->state == BR_STATE_DISABLED)
  44. return;
  45. br_info(br, "port %u(%s) neighbor %.2x%.2x.%pM lost\n",
  46. (unsigned int) p->port_no, p->dev->name,
  47. id->prio[0], id->prio[1], &id->addr);
  48. /*
  49. * According to the spec, the message age timer cannot be
  50. * running when we are the root bridge. So.. this was_root
  51. * check is redundant. I'm leaving it in for now, though.
  52. */
  53. spin_lock(&br->lock);
  54. if (p->state == BR_STATE_DISABLED)
  55. goto unlock;
  56. was_root = br_is_root_bridge(br);
  57. br_become_designated_port(p);
  58. br_configuration_update(br);
  59. br_port_state_selection(br);
  60. if (br_is_root_bridge(br) && !was_root)
  61. br_become_root_bridge(br);
  62. unlock:
  63. spin_unlock(&br->lock);
  64. }
  65. static void br_forward_delay_timer_expired(struct timer_list *t)
  66. {
  67. struct net_bridge_port *p = from_timer(p, t, forward_delay_timer);
  68. struct net_bridge *br = p->br;
  69. br_debug(br, "port %u(%s) forward delay timer\n",
  70. (unsigned int) p->port_no, p->dev->name);
  71. spin_lock(&br->lock);
  72. if (p->state == BR_STATE_LISTENING) {
  73. br_set_state(p, BR_STATE_LEARNING);
  74. mod_timer(&p->forward_delay_timer,
  75. jiffies + br->forward_delay);
  76. } else if (p->state == BR_STATE_LEARNING) {
  77. br_set_state(p, BR_STATE_FORWARDING);
  78. if (br_is_designated_for_some_port(br))
  79. br_topology_change_detection(br);
  80. netif_carrier_on(br->dev);
  81. }
  82. rcu_read_lock();
  83. br_ifinfo_notify(RTM_NEWLINK, NULL, p);
  84. rcu_read_unlock();
  85. spin_unlock(&br->lock);
  86. }
  87. static void br_tcn_timer_expired(struct timer_list *t)
  88. {
  89. struct net_bridge *br = from_timer(br, t, tcn_timer);
  90. br_debug(br, "tcn timer expired\n");
  91. spin_lock(&br->lock);
  92. if (!br_is_root_bridge(br) && (br->dev->flags & IFF_UP)) {
  93. br_transmit_tcn(br);
  94. mod_timer(&br->tcn_timer, jiffies + br->bridge_hello_time);
  95. }
  96. spin_unlock(&br->lock);
  97. }
  98. static void br_topology_change_timer_expired(struct timer_list *t)
  99. {
  100. struct net_bridge *br = from_timer(br, t, topology_change_timer);
  101. br_debug(br, "topo change timer expired\n");
  102. spin_lock(&br->lock);
  103. br->topology_change_detected = 0;
  104. __br_set_topology_change(br, 0);
  105. spin_unlock(&br->lock);
  106. }
  107. static void br_hold_timer_expired(struct timer_list *t)
  108. {
  109. struct net_bridge_port *p = from_timer(p, t, hold_timer);
  110. br_debug(p->br, "port %u(%s) hold timer expired\n",
  111. (unsigned int) p->port_no, p->dev->name);
  112. spin_lock(&p->br->lock);
  113. if (p->config_pending)
  114. br_transmit_config(p);
  115. spin_unlock(&p->br->lock);
  116. }
  117. void br_stp_timer_init(struct net_bridge *br)
  118. {
  119. timer_setup(&br->hello_timer, br_hello_timer_expired, 0);
  120. timer_setup(&br->tcn_timer, br_tcn_timer_expired, 0);
  121. timer_setup(&br->topology_change_timer,
  122. br_topology_change_timer_expired, 0);
  123. }
  124. void br_stp_port_timer_init(struct net_bridge_port *p)
  125. {
  126. timer_setup(&p->message_age_timer, br_message_age_timer_expired, 0);
  127. timer_setup(&p->forward_delay_timer, br_forward_delay_timer_expired, 0);
  128. timer_setup(&p->hold_timer, br_hold_timer_expired, 0);
  129. }
  130. /* Report ticks left (in USER_HZ) used for API */
  131. unsigned long br_timer_value(const struct timer_list *timer)
  132. {
  133. return timer_pending(timer)
  134. ? jiffies_delta_to_clock_t(timer->expires - jiffies) : 0;
  135. }