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 add_timer(&lapb->t1timer);
46 void lapb_start_t2timer(struct lapb_cb *lapb)
48 del_timer(&lapb->t2timer);
50 lapb->t2timer.function = lapb_t2timer_expiry;
51 lapb->t2timer.expires = jiffies + lapb->t2;
53 add_timer(&lapb->t2timer);
56 void lapb_stop_t1timer(struct lapb_cb *lapb)
58 del_timer(&lapb->t1timer);
61 void lapb_stop_t2timer(struct lapb_cb *lapb)
63 del_timer(&lapb->t2timer);
66 int lapb_t1timer_running(struct lapb_cb *lapb)
68 return timer_pending(&lapb->t1timer);
71 static void lapb_t2timer_expiry(struct timer_list *t)
73 struct lapb_cb *lapb = from_timer(lapb, t, t2timer);
75 if (lapb->condition & LAPB_ACK_PENDING_CONDITION) {
76 lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
77 lapb_timeout_response(lapb);
81 static void lapb_t1timer_expiry(struct timer_list *t)
83 struct lapb_cb *lapb = from_timer(lapb, t, t1timer);
85 switch (lapb->state) {
88 * If we are a DCE, send DM up to N2 times, then switch to
89 * STATE_1 and send SABM(E).
92 if (lapb->mode & LAPB_DCE &&
93 lapb->n2count != lapb->n2) {
95 lapb_send_control(lapb, LAPB_DM, LAPB_POLLOFF, LAPB_RESPONSE);
97 lapb->state = LAPB_STATE_1;
98 lapb_establish_data_link(lapb);
103 * Awaiting connection state, send SABM(E), up to N2 times.
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);
114 if (lapb->mode & LAPB_EXTENDED) {
115 lapb_dbg(1, "(%p) S1 TX SABME(1)\n",
117 lapb_send_control(lapb, LAPB_SABME, LAPB_POLLON, LAPB_COMMAND);
119 lapb_dbg(1, "(%p) S1 TX SABM(1)\n",
121 lapb_send_control(lapb, LAPB_SABM, LAPB_POLLON, LAPB_COMMAND);
127 * Awaiting disconnection state, send DISC, up to N2 times.
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);
138 lapb_dbg(1, "(%p) S2 TX DISC(1)\n", lapb->dev);
139 lapb_send_control(lapb, LAPB_DISC, LAPB_POLLON, LAPB_COMMAND);
144 * Data transfer state, restransmit I frames, up to N2 times.
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);
156 lapb_requeue_frames(lapb);
162 * Frame reject state, restransmit FRMR frames, up to N2 times.
165 if (lapb->n2count == lapb->n2) {
166 lapb_clear_queues(lapb);
167 lapb->state = LAPB_STATE_0;
168 lapb_disconnect_indication(lapb, LAPB_TIMEDOUT);
169 lapb_dbg(0, "(%p) S4 -> S0\n", lapb->dev);
173 lapb_transmit_frmr(lapb);
178 lapb_start_t1timer(lapb);