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206 lines
4.9 KiB
206 lines
4.9 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* LAPB release 002 |
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* |
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* This code REQUIRES 2.1.15 or higher/ NET3.038 |
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* |
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* History |
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* LAPB 001 Jonathan Naylor Started Coding |
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* LAPB 002 Jonathan Naylor New timer architecture. |
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*/ |
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
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#include <linux/errno.h> |
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#include <linux/types.h> |
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#include <linux/socket.h> |
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#include <linux/in.h> |
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#include <linux/kernel.h> |
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#include <linux/jiffies.h> |
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#include <linux/timer.h> |
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#include <linux/string.h> |
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#include <linux/sockios.h> |
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#include <linux/net.h> |
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#include <linux/inet.h> |
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#include <linux/skbuff.h> |
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#include <net/sock.h> |
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#include <linux/uaccess.h> |
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#include <linux/fcntl.h> |
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#include <linux/mm.h> |
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#include <linux/interrupt.h> |
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#include <net/lapb.h> |
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static void lapb_t1timer_expiry(struct timer_list *); |
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static void lapb_t2timer_expiry(struct timer_list *); |
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void lapb_start_t1timer(struct lapb_cb *lapb) |
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{ |
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del_timer(&lapb->t1timer); |
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lapb->t1timer.function = lapb_t1timer_expiry; |
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lapb->t1timer.expires = jiffies + lapb->t1; |
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lapb->t1timer_running = true; |
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add_timer(&lapb->t1timer); |
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} |
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void lapb_start_t2timer(struct lapb_cb *lapb) |
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{ |
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del_timer(&lapb->t2timer); |
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lapb->t2timer.function = lapb_t2timer_expiry; |
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lapb->t2timer.expires = jiffies + lapb->t2; |
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lapb->t2timer_running = true; |
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add_timer(&lapb->t2timer); |
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} |
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void lapb_stop_t1timer(struct lapb_cb *lapb) |
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{ |
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lapb->t1timer_running = false; |
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del_timer(&lapb->t1timer); |
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} |
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void lapb_stop_t2timer(struct lapb_cb *lapb) |
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{ |
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lapb->t2timer_running = false; |
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del_timer(&lapb->t2timer); |
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} |
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int lapb_t1timer_running(struct lapb_cb *lapb) |
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{ |
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return lapb->t1timer_running; |
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} |
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static void lapb_t2timer_expiry(struct timer_list *t) |
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{ |
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struct lapb_cb *lapb = from_timer(lapb, t, t2timer); |
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spin_lock_bh(&lapb->lock); |
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if (timer_pending(&lapb->t2timer)) /* A new timer has been set up */ |
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goto out; |
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if (!lapb->t2timer_running) /* The timer has been stopped */ |
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goto out; |
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if (lapb->condition & LAPB_ACK_PENDING_CONDITION) { |
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lapb->condition &= ~LAPB_ACK_PENDING_CONDITION; |
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lapb_timeout_response(lapb); |
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} |
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lapb->t2timer_running = false; |
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out: |
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spin_unlock_bh(&lapb->lock); |
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} |
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static void lapb_t1timer_expiry(struct timer_list *t) |
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{ |
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struct lapb_cb *lapb = from_timer(lapb, t, t1timer); |
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spin_lock_bh(&lapb->lock); |
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if (timer_pending(&lapb->t1timer)) /* A new timer has been set up */ |
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goto out; |
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if (!lapb->t1timer_running) /* The timer has been stopped */ |
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goto out; |
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switch (lapb->state) { |
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/* |
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* If we are a DCE, send DM up to N2 times, then switch to |
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* STATE_1 and send SABM(E). |
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*/ |
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case LAPB_STATE_0: |
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if (lapb->mode & LAPB_DCE && |
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lapb->n2count != lapb->n2) { |
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lapb->n2count++; |
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lapb_send_control(lapb, LAPB_DM, LAPB_POLLOFF, LAPB_RESPONSE); |
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} else { |
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lapb->state = LAPB_STATE_1; |
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lapb_establish_data_link(lapb); |
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} |
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break; |
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/* |
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* Awaiting connection state, send SABM(E), up to N2 times. |
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*/ |
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case LAPB_STATE_1: |
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if (lapb->n2count == lapb->n2) { |
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lapb_clear_queues(lapb); |
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lapb->state = LAPB_STATE_0; |
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lapb_disconnect_indication(lapb, LAPB_TIMEDOUT); |
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lapb_dbg(0, "(%p) S1 -> S0\n", lapb->dev); |
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lapb->t1timer_running = false; |
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goto out; |
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} else { |
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lapb->n2count++; |
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if (lapb->mode & LAPB_EXTENDED) { |
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lapb_dbg(1, "(%p) S1 TX SABME(1)\n", |
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lapb->dev); |
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lapb_send_control(lapb, LAPB_SABME, LAPB_POLLON, LAPB_COMMAND); |
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} else { |
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lapb_dbg(1, "(%p) S1 TX SABM(1)\n", |
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lapb->dev); |
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lapb_send_control(lapb, LAPB_SABM, LAPB_POLLON, LAPB_COMMAND); |
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} |
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} |
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break; |
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/* |
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* Awaiting disconnection state, send DISC, up to N2 times. |
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*/ |
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case LAPB_STATE_2: |
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if (lapb->n2count == lapb->n2) { |
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lapb_clear_queues(lapb); |
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lapb->state = LAPB_STATE_0; |
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lapb_disconnect_confirmation(lapb, LAPB_TIMEDOUT); |
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lapb_dbg(0, "(%p) S2 -> S0\n", lapb->dev); |
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lapb->t1timer_running = false; |
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goto out; |
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} else { |
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lapb->n2count++; |
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lapb_dbg(1, "(%p) S2 TX DISC(1)\n", lapb->dev); |
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lapb_send_control(lapb, LAPB_DISC, LAPB_POLLON, LAPB_COMMAND); |
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} |
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break; |
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/* |
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* Data transfer state, restransmit I frames, up to N2 times. |
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*/ |
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case LAPB_STATE_3: |
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if (lapb->n2count == lapb->n2) { |
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lapb_clear_queues(lapb); |
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lapb->state = LAPB_STATE_0; |
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lapb_stop_t2timer(lapb); |
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lapb_disconnect_indication(lapb, LAPB_TIMEDOUT); |
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lapb_dbg(0, "(%p) S3 -> S0\n", lapb->dev); |
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lapb->t1timer_running = false; |
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goto out; |
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} else { |
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lapb->n2count++; |
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lapb_requeue_frames(lapb); |
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lapb_kick(lapb); |
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} |
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break; |
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/* |
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* Frame reject state, restransmit FRMR frames, up to N2 times. |
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*/ |
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case LAPB_STATE_4: |
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if (lapb->n2count == lapb->n2) { |
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lapb_clear_queues(lapb); |
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lapb->state = LAPB_STATE_0; |
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lapb_disconnect_indication(lapb, LAPB_TIMEDOUT); |
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lapb_dbg(0, "(%p) S4 -> S0\n", lapb->dev); |
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lapb->t1timer_running = false; |
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goto out; |
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} else { |
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lapb->n2count++; |
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lapb_transmit_frmr(lapb); |
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} |
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break; |
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} |
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lapb_start_t1timer(lapb); |
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out: |
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spin_unlock_bh(&lapb->lock); |
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}
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