1 /* 2 * LAPB release 002 3 * 4 * This code REQUIRES 2.1.15 or higher/ NET3.038 5 * 6 * This module: 7 * This module is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License 9 * as published by the Free Software Foundation; either version 10 * 2 of the License, or (at your option) any later version. 11 * 12 * History 13 * LAPB 001 Jonathan Naylor Started Coding 14 * LAPB 002 Jonathan Naylor New timer architecture. 15 */ 16 17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 18 19 #include <linux/errno.h> 20 #include <linux/types.h> 21 #include <linux/socket.h> 22 #include <linux/in.h> 23 #include <linux/kernel.h> 24 #include <linux/jiffies.h> 25 #include <linux/timer.h> 26 #include <linux/string.h> 27 #include <linux/sockios.h> 28 #include <linux/net.h> 29 #include <linux/inet.h> 30 #include <linux/skbuff.h> 31 #include <net/sock.h> 32 #include <asm/uaccess.h> 33 #include <linux/fcntl.h> 34 #include <linux/mm.h> 35 #include <linux/interrupt.h> 36 #include <net/lapb.h> 37 38 static void lapb_t1timer_expiry(unsigned long); 39 static void lapb_t2timer_expiry(unsigned long); 40 41 void lapb_start_t1timer(struct lapb_cb *lapb) 42 { 43 del_timer(&lapb->t1timer); 44 45 lapb->t1timer.data = (unsigned long)lapb; 46 lapb->t1timer.function = &lapb_t1timer_expiry; 47 lapb->t1timer.expires = jiffies + lapb->t1; 48 49 add_timer(&lapb->t1timer); 50 } 51 52 void lapb_start_t2timer(struct lapb_cb *lapb) 53 { 54 del_timer(&lapb->t2timer); 55 56 lapb->t2timer.data = (unsigned long)lapb; 57 lapb->t2timer.function = &lapb_t2timer_expiry; 58 lapb->t2timer.expires = jiffies + lapb->t2; 59 60 add_timer(&lapb->t2timer); 61 } 62 63 void lapb_stop_t1timer(struct lapb_cb *lapb) 64 { 65 del_timer(&lapb->t1timer); 66 } 67 68 void lapb_stop_t2timer(struct lapb_cb *lapb) 69 { 70 del_timer(&lapb->t2timer); 71 } 72 73 int lapb_t1timer_running(struct lapb_cb *lapb) 74 { 75 return timer_pending(&lapb->t1timer); 76 } 77 78 static void lapb_t2timer_expiry(unsigned long param) 79 { 80 struct lapb_cb *lapb = (struct lapb_cb *)param; 81 82 if (lapb->condition & LAPB_ACK_PENDING_CONDITION) { 83 lapb->condition &= ~LAPB_ACK_PENDING_CONDITION; 84 lapb_timeout_response(lapb); 85 } 86 } 87 88 static void lapb_t1timer_expiry(unsigned long param) 89 { 90 struct lapb_cb *lapb = (struct lapb_cb *)param; 91 92 switch (lapb->state) { 93 94 /* 95 * If we are a DCE, keep going DM .. DM .. DM 96 */ 97 case LAPB_STATE_0: 98 if (lapb->mode & LAPB_DCE) 99 lapb_send_control(lapb, LAPB_DM, LAPB_POLLOFF, LAPB_RESPONSE); 100 break; 101 102 /* 103 * Awaiting connection state, send SABM(E), up to N2 times. 104 */ 105 case LAPB_STATE_1: 106 if (lapb->n2count == lapb->n2) { 107 lapb_clear_queues(lapb); 108 lapb->state = LAPB_STATE_0; 109 lapb_disconnect_indication(lapb, LAPB_TIMEDOUT); 110 lapb_dbg(0, "(%p) S1 -> S0\n", lapb->dev); 111 return; 112 } else { 113 lapb->n2count++; 114 if (lapb->mode & LAPB_EXTENDED) { 115 lapb_dbg(1, "(%p) S1 TX SABME(1)\n", 116 lapb->dev); 117 lapb_send_control(lapb, LAPB_SABME, LAPB_POLLON, LAPB_COMMAND); 118 } else { 119 lapb_dbg(1, "(%p) S1 TX SABM(1)\n", 120 lapb->dev); 121 lapb_send_control(lapb, LAPB_SABM, LAPB_POLLON, LAPB_COMMAND); 122 } 123 } 124 break; 125 126 /* 127 * Awaiting disconnection state, send DISC, up to N2 times. 128 */ 129 case LAPB_STATE_2: 130 if (lapb->n2count == lapb->n2) { 131 lapb_clear_queues(lapb); 132 lapb->state = LAPB_STATE_0; 133 lapb_disconnect_confirmation(lapb, LAPB_TIMEDOUT); 134 lapb_dbg(0, "(%p) S2 -> S0\n", lapb->dev); 135 return; 136 } else { 137 lapb->n2count++; 138 lapb_dbg(1, "(%p) S2 TX DISC(1)\n", lapb->dev); 139 lapb_send_control(lapb, LAPB_DISC, LAPB_POLLON, LAPB_COMMAND); 140 } 141 break; 142 143 /* 144 * Data transfer state, restransmit I frames, up to N2 times. 145 */ 146 case LAPB_STATE_3: 147 if (lapb->n2count == lapb->n2) { 148 lapb_clear_queues(lapb); 149 lapb->state = LAPB_STATE_0; 150 lapb_stop_t2timer(lapb); 151 lapb_disconnect_indication(lapb, LAPB_TIMEDOUT); 152 lapb_dbg(0, "(%p) S3 -> S0\n", lapb->dev); 153 return; 154 } else { 155 lapb->n2count++; 156 lapb_requeue_frames(lapb); 157 } 158 break; 159 160 /* 161 * Frame reject state, restransmit FRMR frames, up to N2 times. 162 */ 163 case LAPB_STATE_4: 164 if (lapb->n2count == lapb->n2) { 165 lapb_clear_queues(lapb); 166 lapb->state = LAPB_STATE_0; 167 lapb_disconnect_indication(lapb, LAPB_TIMEDOUT); 168 lapb_dbg(0, "(%p) S4 -> S0\n", lapb->dev); 169 return; 170 } else { 171 lapb->n2count++; 172 lapb_transmit_frmr(lapb); 173 } 174 break; 175 } 176 177 lapb_start_t1timer(lapb); 178 } 179