1 // SPDX-License-Identifier: GPL-2.0-or-later
5 * This code REQUIRES 2.1.15 or higher/ NET3.038
8 * LAPB 001 Jonathan Naylor Started Coding
9 * LAPB 002 Jonathan Naylor New timer architecture.
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 #include <linux/errno.h>
15 #include <linux/types.h>
16 #include <linux/socket.h>
18 #include <linux/kernel.h>
19 #include <linux/jiffies.h>
20 #include <linux/timer.h>
21 #include <linux/string.h>
22 #include <linux/sockios.h>
23 #include <linux/net.h>
24 #include <linux/inet.h>
25 #include <linux/skbuff.h>
27 #include <linux/uaccess.h>
28 #include <linux/fcntl.h>
30 #include <linux/interrupt.h>
33 static void lapb_t1timer_expiry(struct timer_list
*);
34 static void lapb_t2timer_expiry(struct timer_list
*);
36 void lapb_start_t1timer(struct lapb_cb
*lapb
)
38 del_timer(&lapb
->t1timer
);
40 lapb
->t1timer
.function
= lapb_t1timer_expiry
;
41 lapb
->t1timer
.expires
= jiffies
+ lapb
->t1
;
43 lapb
->t1timer_running
= true;
44 add_timer(&lapb
->t1timer
);
47 void lapb_start_t2timer(struct lapb_cb
*lapb
)
49 del_timer(&lapb
->t2timer
);
51 lapb
->t2timer
.function
= lapb_t2timer_expiry
;
52 lapb
->t2timer
.expires
= jiffies
+ lapb
->t2
;
54 lapb
->t2timer_running
= true;
55 add_timer(&lapb
->t2timer
);
58 void lapb_stop_t1timer(struct lapb_cb
*lapb
)
60 lapb
->t1timer_running
= false;
61 del_timer(&lapb
->t1timer
);
64 void lapb_stop_t2timer(struct lapb_cb
*lapb
)
66 lapb
->t2timer_running
= false;
67 del_timer(&lapb
->t2timer
);
70 int lapb_t1timer_running(struct lapb_cb
*lapb
)
72 return lapb
->t1timer_running
;
75 static void lapb_t2timer_expiry(struct timer_list
*t
)
77 struct lapb_cb
*lapb
= from_timer(lapb
, t
, t2timer
);
79 spin_lock_bh(&lapb
->lock
);
80 if (timer_pending(&lapb
->t2timer
)) /* A new timer has been set up */
82 if (!lapb
->t2timer_running
) /* The timer has been stopped */
85 if (lapb
->condition
& LAPB_ACK_PENDING_CONDITION
) {
86 lapb
->condition
&= ~LAPB_ACK_PENDING_CONDITION
;
87 lapb_timeout_response(lapb
);
89 lapb
->t2timer_running
= false;
92 spin_unlock_bh(&lapb
->lock
);
95 static void lapb_t1timer_expiry(struct timer_list
*t
)
97 struct lapb_cb
*lapb
= from_timer(lapb
, t
, t1timer
);
99 spin_lock_bh(&lapb
->lock
);
100 if (timer_pending(&lapb
->t1timer
)) /* A new timer has been set up */
102 if (!lapb
->t1timer_running
) /* The timer has been stopped */
105 switch (lapb
->state
) {
108 * If we are a DCE, send DM up to N2 times, then switch to
109 * STATE_1 and send SABM(E).
112 if (lapb
->mode
& LAPB_DCE
&&
113 lapb
->n2count
!= lapb
->n2
) {
115 lapb_send_control(lapb
, LAPB_DM
, LAPB_POLLOFF
, LAPB_RESPONSE
);
117 lapb
->state
= LAPB_STATE_1
;
118 lapb_establish_data_link(lapb
);
123 * Awaiting connection state, send SABM(E), up to N2 times.
126 if (lapb
->n2count
== lapb
->n2
) {
127 lapb_clear_queues(lapb
);
128 lapb
->state
= LAPB_STATE_0
;
129 lapb_disconnect_indication(lapb
, LAPB_TIMEDOUT
);
130 lapb_dbg(0, "(%p) S1 -> S0\n", lapb
->dev
);
131 lapb
->t1timer_running
= false;
135 if (lapb
->mode
& LAPB_EXTENDED
) {
136 lapb_dbg(1, "(%p) S1 TX SABME(1)\n",
138 lapb_send_control(lapb
, LAPB_SABME
, LAPB_POLLON
, LAPB_COMMAND
);
140 lapb_dbg(1, "(%p) S1 TX SABM(1)\n",
142 lapb_send_control(lapb
, LAPB_SABM
, LAPB_POLLON
, LAPB_COMMAND
);
148 * Awaiting disconnection state, send DISC, up to N2 times.
151 if (lapb
->n2count
== lapb
->n2
) {
152 lapb_clear_queues(lapb
);
153 lapb
->state
= LAPB_STATE_0
;
154 lapb_disconnect_confirmation(lapb
, LAPB_TIMEDOUT
);
155 lapb_dbg(0, "(%p) S2 -> S0\n", lapb
->dev
);
156 lapb
->t1timer_running
= false;
160 lapb_dbg(1, "(%p) S2 TX DISC(1)\n", lapb
->dev
);
161 lapb_send_control(lapb
, LAPB_DISC
, LAPB_POLLON
, LAPB_COMMAND
);
166 * Data transfer state, restransmit I frames, up to N2 times.
169 if (lapb
->n2count
== lapb
->n2
) {
170 lapb_clear_queues(lapb
);
171 lapb
->state
= LAPB_STATE_0
;
172 lapb_stop_t2timer(lapb
);
173 lapb_disconnect_indication(lapb
, LAPB_TIMEDOUT
);
174 lapb_dbg(0, "(%p) S3 -> S0\n", lapb
->dev
);
175 lapb
->t1timer_running
= false;
179 lapb_requeue_frames(lapb
);
185 * Frame reject state, restransmit FRMR frames, up to N2 times.
188 if (lapb
->n2count
== lapb
->n2
) {
189 lapb_clear_queues(lapb
);
190 lapb
->state
= LAPB_STATE_0
;
191 lapb_disconnect_indication(lapb
, LAPB_TIMEDOUT
);
192 lapb_dbg(0, "(%p) S4 -> S0\n", lapb
->dev
);
193 lapb
->t1timer_running
= false;
197 lapb_transmit_frmr(lapb
);
202 lapb_start_t1timer(lapb
);
205 spin_unlock_bh(&lapb
->lock
);