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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 | // SPDX-License-Identifier: GPL-2.0-or-later /* * LAPB release 002 * * This code REQUIRES 2.1.15 or higher/ NET3.038 * * History * LAPB 001 Jonathan Naylor Started Coding * LAPB 002 Jonathan Naylor New timer architecture. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/errno.h> #include <linux/types.h> #include <linux/socket.h> #include <linux/in.h> #include <linux/kernel.h> #include <linux/jiffies.h> #include <linux/timer.h> #include <linux/string.h> #include <linux/sockios.h> #include <linux/net.h> #include <linux/inet.h> #include <linux/skbuff.h> #include <net/sock.h> #include <linux/uaccess.h> #include <linux/fcntl.h> #include <linux/mm.h> #include <linux/interrupt.h> #include <net/lapb.h> static void lapb_t1timer_expiry(struct timer_list *); static void lapb_t2timer_expiry(struct timer_list *); void lapb_start_t1timer(struct lapb_cb *lapb) { del_timer(&lapb->t1timer); lapb->t1timer.function = lapb_t1timer_expiry; lapb->t1timer.expires = jiffies + lapb->t1; lapb->t1timer_running = true; add_timer(&lapb->t1timer); } void lapb_start_t2timer(struct lapb_cb *lapb) { del_timer(&lapb->t2timer); lapb->t2timer.function = lapb_t2timer_expiry; lapb->t2timer.expires = jiffies + lapb->t2; lapb->t2timer_running = true; add_timer(&lapb->t2timer); } void lapb_stop_t1timer(struct lapb_cb *lapb) { lapb->t1timer_running = false; del_timer(&lapb->t1timer); } void lapb_stop_t2timer(struct lapb_cb *lapb) { lapb->t2timer_running = false; del_timer(&lapb->t2timer); } int lapb_t1timer_running(struct lapb_cb *lapb) { return lapb->t1timer_running; } static void lapb_t2timer_expiry(struct timer_list *t) { struct lapb_cb *lapb = from_timer(lapb, t, t2timer); spin_lock_bh(&lapb->lock); if (timer_pending(&lapb->t2timer)) /* A new timer has been set up */ goto out; if (!lapb->t2timer_running) /* The timer has been stopped */ goto out; if (lapb->condition & LAPB_ACK_PENDING_CONDITION) { lapb->condition &= ~LAPB_ACK_PENDING_CONDITION; lapb_timeout_response(lapb); } lapb->t2timer_running = false; out: spin_unlock_bh(&lapb->lock); } static void lapb_t1timer_expiry(struct timer_list *t) { struct lapb_cb *lapb = from_timer(lapb, t, t1timer); spin_lock_bh(&lapb->lock); if (timer_pending(&lapb->t1timer)) /* A new timer has been set up */ goto out; if (!lapb->t1timer_running) /* The timer has been stopped */ goto out; switch (lapb->state) { /* * If we are a DCE, send DM up to N2 times, then switch to * STATE_1 and send SABM(E). */ case LAPB_STATE_0: if (lapb->mode & LAPB_DCE && lapb->n2count != lapb->n2) { lapb->n2count++; lapb_send_control(lapb, LAPB_DM, LAPB_POLLOFF, LAPB_RESPONSE); } else { lapb->state = LAPB_STATE_1; lapb_establish_data_link(lapb); } break; /* * Awaiting connection state, send SABM(E), up to N2 times. */ case LAPB_STATE_1: if (lapb->n2count == lapb->n2) { lapb_clear_queues(lapb); lapb->state = LAPB_STATE_0; lapb_disconnect_indication(lapb, LAPB_TIMEDOUT); lapb_dbg(0, "(%p) S1 -> S0\n", lapb->dev); lapb->t1timer_running = false; goto out; } else { lapb->n2count++; if (lapb->mode & LAPB_EXTENDED) { lapb_dbg(1, "(%p) S1 TX SABME(1)\n", lapb->dev); lapb_send_control(lapb, LAPB_SABME, LAPB_POLLON, LAPB_COMMAND); } else { lapb_dbg(1, "(%p) S1 TX SABM(1)\n", lapb->dev); lapb_send_control(lapb, LAPB_SABM, LAPB_POLLON, LAPB_COMMAND); } } break; /* * Awaiting disconnection state, send DISC, up to N2 times. */ case LAPB_STATE_2: if (lapb->n2count == lapb->n2) { lapb_clear_queues(lapb); lapb->state = LAPB_STATE_0; lapb_disconnect_confirmation(lapb, LAPB_TIMEDOUT); lapb_dbg(0, "(%p) S2 -> S0\n", lapb->dev); lapb->t1timer_running = false; goto out; } else { lapb->n2count++; lapb_dbg(1, "(%p) S2 TX DISC(1)\n", lapb->dev); lapb_send_control(lapb, LAPB_DISC, LAPB_POLLON, LAPB_COMMAND); } break; /* * Data transfer state, restransmit I frames, up to N2 times. */ case LAPB_STATE_3: if (lapb->n2count == lapb->n2) { lapb_clear_queues(lapb); lapb->state = LAPB_STATE_0; lapb_stop_t2timer(lapb); lapb_disconnect_indication(lapb, LAPB_TIMEDOUT); lapb_dbg(0, "(%p) S3 -> S0\n", lapb->dev); lapb->t1timer_running = false; goto out; } else { lapb->n2count++; lapb_requeue_frames(lapb); lapb_kick(lapb); } break; /* * Frame reject state, restransmit FRMR frames, up to N2 times. */ case LAPB_STATE_4: if (lapb->n2count == lapb->n2) { lapb_clear_queues(lapb); lapb->state = LAPB_STATE_0; lapb_disconnect_indication(lapb, LAPB_TIMEDOUT); lapb_dbg(0, "(%p) S4 -> S0\n", lapb->dev); lapb->t1timer_running = false; goto out; } else { lapb->n2count++; lapb_transmit_frmr(lapb); } break; } lapb_start_t1timer(lapb); out: spin_unlock_bh(&lapb->lock); } |