GNU Linux-libre 4.14.266-gnu1
[releases.git] / net / lapb / lapb_timer.c
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 <linux/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                                 lapb_kick(lapb);
158                         }
159                         break;
160
161                 /*
162                  *      Frame reject state, restransmit FRMR frames, up to N2 times.
163                  */
164                 case LAPB_STATE_4:
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);
170                                 return;
171                         } else {
172                                 lapb->n2count++;
173                                 lapb_transmit_frmr(lapb);
174                         }
175                         break;
176         }
177
178         lapb_start_t1timer(lapb);
179 }