lapb_timer.c 4.0 KB

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  1. // SPDX-License-Identifier: GPL-2.0-or-later
  2. /*
  3. * LAPB release 002
  4. *
  5. * This code REQUIRES 2.1.15 or higher/ NET3.038
  6. *
  7. * History
  8. * LAPB 001 Jonathan Naylor Started Coding
  9. * LAPB 002 Jonathan Naylor New timer architecture.
  10. */
  11. #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  12. #include <linux/errno.h>
  13. #include <linux/types.h>
  14. #include <linux/socket.h>
  15. #include <linux/in.h>
  16. #include <linux/kernel.h>
  17. #include <linux/jiffies.h>
  18. #include <linux/timer.h>
  19. #include <linux/string.h>
  20. #include <linux/sockios.h>
  21. #include <linux/net.h>
  22. #include <linux/inet.h>
  23. #include <linux/skbuff.h>
  24. #include <net/sock.h>
  25. #include <linux/uaccess.h>
  26. #include <linux/fcntl.h>
  27. #include <linux/mm.h>
  28. #include <linux/interrupt.h>
  29. #include <net/lapb.h>
  30. static void lapb_t1timer_expiry(struct timer_list *);
  31. static void lapb_t2timer_expiry(struct timer_list *);
  32. void lapb_start_t1timer(struct lapb_cb *lapb)
  33. {
  34. del_timer(&lapb->t1timer);
  35. lapb->t1timer.function = lapb_t1timer_expiry;
  36. lapb->t1timer.expires = jiffies + lapb->t1;
  37. add_timer(&lapb->t1timer);
  38. }
  39. void lapb_start_t2timer(struct lapb_cb *lapb)
  40. {
  41. del_timer(&lapb->t2timer);
  42. lapb->t2timer.function = lapb_t2timer_expiry;
  43. lapb->t2timer.expires = jiffies + lapb->t2;
  44. add_timer(&lapb->t2timer);
  45. }
  46. void lapb_stop_t1timer(struct lapb_cb *lapb)
  47. {
  48. del_timer(&lapb->t1timer);
  49. }
  50. void lapb_stop_t2timer(struct lapb_cb *lapb)
  51. {
  52. del_timer(&lapb->t2timer);
  53. }
  54. int lapb_t1timer_running(struct lapb_cb *lapb)
  55. {
  56. return timer_pending(&lapb->t1timer);
  57. }
  58. static void lapb_t2timer_expiry(struct timer_list *t)
  59. {
  60. struct lapb_cb *lapb = from_timer(lapb, t, t2timer);
  61. if (lapb->condition & LAPB_ACK_PENDING_CONDITION) {
  62. lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
  63. lapb_timeout_response(lapb);
  64. }
  65. }
  66. static void lapb_t1timer_expiry(struct timer_list *t)
  67. {
  68. struct lapb_cb *lapb = from_timer(lapb, t, t1timer);
  69. switch (lapb->state) {
  70. /*
  71. * If we are a DCE, keep going DM .. DM .. DM
  72. */
  73. case LAPB_STATE_0:
  74. if (lapb->mode & LAPB_DCE)
  75. lapb_send_control(lapb, LAPB_DM, LAPB_POLLOFF, LAPB_RESPONSE);
  76. break;
  77. /*
  78. * Awaiting connection state, send SABM(E), up to N2 times.
  79. */
  80. case LAPB_STATE_1:
  81. if (lapb->n2count == lapb->n2) {
  82. lapb_clear_queues(lapb);
  83. lapb->state = LAPB_STATE_0;
  84. lapb_disconnect_indication(lapb, LAPB_TIMEDOUT);
  85. lapb_dbg(0, "(%p) S1 -> S0\n", lapb->dev);
  86. return;
  87. } else {
  88. lapb->n2count++;
  89. if (lapb->mode & LAPB_EXTENDED) {
  90. lapb_dbg(1, "(%p) S1 TX SABME(1)\n",
  91. lapb->dev);
  92. lapb_send_control(lapb, LAPB_SABME, LAPB_POLLON, LAPB_COMMAND);
  93. } else {
  94. lapb_dbg(1, "(%p) S1 TX SABM(1)\n",
  95. lapb->dev);
  96. lapb_send_control(lapb, LAPB_SABM, LAPB_POLLON, LAPB_COMMAND);
  97. }
  98. }
  99. break;
  100. /*
  101. * Awaiting disconnection state, send DISC, up to N2 times.
  102. */
  103. case LAPB_STATE_2:
  104. if (lapb->n2count == lapb->n2) {
  105. lapb_clear_queues(lapb);
  106. lapb->state = LAPB_STATE_0;
  107. lapb_disconnect_confirmation(lapb, LAPB_TIMEDOUT);
  108. lapb_dbg(0, "(%p) S2 -> S0\n", lapb->dev);
  109. return;
  110. } else {
  111. lapb->n2count++;
  112. lapb_dbg(1, "(%p) S2 TX DISC(1)\n", lapb->dev);
  113. lapb_send_control(lapb, LAPB_DISC, LAPB_POLLON, LAPB_COMMAND);
  114. }
  115. break;
  116. /*
  117. * Data transfer state, restransmit I frames, up to N2 times.
  118. */
  119. case LAPB_STATE_3:
  120. if (lapb->n2count == lapb->n2) {
  121. lapb_clear_queues(lapb);
  122. lapb->state = LAPB_STATE_0;
  123. lapb_stop_t2timer(lapb);
  124. lapb_disconnect_indication(lapb, LAPB_TIMEDOUT);
  125. lapb_dbg(0, "(%p) S3 -> S0\n", lapb->dev);
  126. return;
  127. } else {
  128. lapb->n2count++;
  129. lapb_requeue_frames(lapb);
  130. lapb_kick(lapb);
  131. }
  132. break;
  133. /*
  134. * Frame reject state, restransmit FRMR frames, up to N2 times.
  135. */
  136. case LAPB_STATE_4:
  137. if (lapb->n2count == lapb->n2) {
  138. lapb_clear_queues(lapb);
  139. lapb->state = LAPB_STATE_0;
  140. lapb_disconnect_indication(lapb, LAPB_TIMEDOUT);
  141. lapb_dbg(0, "(%p) S4 -> S0\n", lapb->dev);
  142. return;
  143. } else {
  144. lapb->n2count++;
  145. lapb_transmit_frmr(lapb);
  146. }
  147. break;
  148. }
  149. lapb_start_t1timer(lapb);
  150. }