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1/*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License as published by
4 * the Free Software Foundation; either version 2 of the License, or
5 * (at your option) any later version.
6 *
7 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
8 * Copyright (C) Joerg Reuter DL1BKE (jreuter@yaina.de)
9 */
10#include <linux/errno.h>
11#include <linux/types.h>
12#include <linux/socket.h>
13#include <linux/in.h>
14#include <linux/kernel.h>
15#include <linux/timer.h>
16#include <linux/string.h>
17#include <linux/sockios.h>
18#include <linux/spinlock.h>
19#include <linux/net.h>
20#include <linux/gfp.h>
21#include <net/ax25.h>
22#include <linux/inet.h>
23#include <linux/netdevice.h>
24#include <linux/skbuff.h>
25#include <net/sock.h>
26#include <linux/uaccess.h>
27#include <linux/fcntl.h>
28#include <linux/mm.h>
29#include <linux/interrupt.h>
30
31void ax25_ds_nr_error_recovery(ax25_cb *ax25)
32{
33 ax25_ds_establish_data_link(ax25);
34}
35
36/*
37 * dl1bke 960114: transmit I frames on DAMA poll
38 */
39void ax25_ds_enquiry_response(ax25_cb *ax25)
40{
41 ax25_cb *ax25o;
42
43 /* Please note that neither DK4EG's nor DG2FEF's
44 * DAMA spec mention the following behaviour as seen
45 * with TheFirmware:
46 *
47 * DB0ACH->DL1BKE <RR C P R0> [DAMA]
48 * DL1BKE->DB0ACH <I NR=0 NS=0>
49 * DL1BKE-7->DB0PRA-6 DB0ACH <I C S3 R5>
50 * DL1BKE->DB0ACH <RR R F R0>
51 *
52 * The Flexnet DAMA Master implementation apparently
53 * insists on the "proper" AX.25 behaviour:
54 *
55 * DB0ACH->DL1BKE <RR C P R0> [DAMA]
56 * DL1BKE->DB0ACH <RR R F R0>
57 * DL1BKE->DB0ACH <I NR=0 NS=0>
58 * DL1BKE-7->DB0PRA-6 DB0ACH <I C S3 R5>
59 *
60 * Flexnet refuses to send us *any* I frame if we send
61 * a REJ in case AX25_COND_REJECT is set. It is superfluous in
62 * this mode anyway (a RR or RNR invokes the retransmission).
63 * Is this a Flexnet bug?
64 */
65
66 ax25_std_enquiry_response(ax25);
67
68 if (!(ax25->condition & AX25_COND_PEER_RX_BUSY)) {
69 ax25_requeue_frames(ax25);
70 ax25_kick(ax25);
71 }
72
73 if (ax25->state == AX25_STATE_1 || ax25->state == AX25_STATE_2 || skb_peek(&ax25->ack_queue) != NULL)
74 ax25_ds_t1_timeout(ax25);
75 else
76 ax25->n2count = 0;
77
78 ax25_start_t3timer(ax25);
79 ax25_ds_set_timer(ax25->ax25_dev);
80
81 spin_lock(&ax25_list_lock);
82 ax25_for_each(ax25o, &ax25_list) {
83 if (ax25o == ax25)
84 continue;
85
86 if (ax25o->ax25_dev != ax25->ax25_dev)
87 continue;
88
89 if (ax25o->state == AX25_STATE_1 || ax25o->state == AX25_STATE_2) {
90 ax25_ds_t1_timeout(ax25o);
91 continue;
92 }
93
94 if (!(ax25o->condition & AX25_COND_PEER_RX_BUSY) && ax25o->state == AX25_STATE_3) {
95 ax25_requeue_frames(ax25o);
96 ax25_kick(ax25o);
97 }
98
99 if (ax25o->state == AX25_STATE_1 || ax25o->state == AX25_STATE_2 || skb_peek(&ax25o->ack_queue) != NULL)
100 ax25_ds_t1_timeout(ax25o);
101
102 /* do not start T3 for listening sockets (tnx DD8NE) */
103
104 if (ax25o->state != AX25_STATE_0)
105 ax25_start_t3timer(ax25o);
106 }
107 spin_unlock(&ax25_list_lock);
108}
109
110void ax25_ds_establish_data_link(ax25_cb *ax25)
111{
112 ax25->condition &= AX25_COND_DAMA_MODE;
113 ax25->n2count = 0;
114 ax25_calculate_t1(ax25);
115 ax25_start_t1timer(ax25);
116 ax25_stop_t2timer(ax25);
117 ax25_start_t3timer(ax25);
118}
119
120/*
121 * :::FIXME:::
122 * This is a kludge. Not all drivers recognize kiss commands.
123 * We need a driver level request to switch duplex mode, that does
124 * either SCC changing, PI config or KISS as required. Currently
125 * this request isn't reliable.
126 */
127static void ax25_kiss_cmd(ax25_dev *ax25_dev, unsigned char cmd, unsigned char param)
128{
129 struct sk_buff *skb;
130 unsigned char *p;
131
132 if (ax25_dev->dev == NULL)
133 return;
134
135 if ((skb = alloc_skb(2, GFP_ATOMIC)) == NULL)
136 return;
137
138 skb_reset_network_header(skb);
139 p = skb_put(skb, 2);
140
141 *p++ = cmd;
142 *p++ = param;
143
144 skb->protocol = ax25_type_trans(skb, ax25_dev->dev);
145
146 dev_queue_xmit(skb);
147}
148
149/*
150 * A nasty problem arises if we count the number of DAMA connections
151 * wrong, especially when connections on the device already existed
152 * and our network node (or the sysop) decides to turn on DAMA Master
153 * mode. We thus flag the 'real' slave connections with
154 * ax25->dama_slave=1 and look on every disconnect if still slave
155 * connections exist.
156 */
157static int ax25_check_dama_slave(ax25_dev *ax25_dev)
158{
159 ax25_cb *ax25;
160 int res = 0;
161
162 spin_lock(&ax25_list_lock);
163 ax25_for_each(ax25, &ax25_list)
164 if (ax25->ax25_dev == ax25_dev && (ax25->condition & AX25_COND_DAMA_MODE) && ax25->state > AX25_STATE_1) {
165 res = 1;
166 break;
167 }
168 spin_unlock(&ax25_list_lock);
169
170 return res;
171}
172
173static void ax25_dev_dama_on(ax25_dev *ax25_dev)
174{
175 if (ax25_dev == NULL)
176 return;
177
178 if (ax25_dev->dama.slave == 0)
179 ax25_kiss_cmd(ax25_dev, 5, 1);
180
181 ax25_dev->dama.slave = 1;
182 ax25_ds_set_timer(ax25_dev);
183}
184
185void ax25_dev_dama_off(ax25_dev *ax25_dev)
186{
187 if (ax25_dev == NULL)
188 return;
189
190 if (ax25_dev->dama.slave && !ax25_check_dama_slave(ax25_dev)) {
191 ax25_kiss_cmd(ax25_dev, 5, 0);
192 ax25_dev->dama.slave = 0;
193 ax25_ds_del_timer(ax25_dev);
194 }
195}
196
197void ax25_dama_on(ax25_cb *ax25)
198{
199 ax25_dev_dama_on(ax25->ax25_dev);
200 ax25->condition |= AX25_COND_DAMA_MODE;
201}
202
203void ax25_dama_off(ax25_cb *ax25)
204{
205 ax25->condition &= ~AX25_COND_DAMA_MODE;
206 ax25_dev_dama_off(ax25->ax25_dev);
207}
208
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *
4 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
5 * Copyright (C) Joerg Reuter DL1BKE (jreuter@yaina.de)
6 */
7#include <linux/errno.h>
8#include <linux/types.h>
9#include <linux/socket.h>
10#include <linux/in.h>
11#include <linux/kernel.h>
12#include <linux/timer.h>
13#include <linux/string.h>
14#include <linux/sockios.h>
15#include <linux/spinlock.h>
16#include <linux/net.h>
17#include <linux/gfp.h>
18#include <net/ax25.h>
19#include <linux/inet.h>
20#include <linux/netdevice.h>
21#include <linux/skbuff.h>
22#include <net/sock.h>
23#include <linux/uaccess.h>
24#include <linux/fcntl.h>
25#include <linux/mm.h>
26#include <linux/interrupt.h>
27
28void ax25_ds_nr_error_recovery(ax25_cb *ax25)
29{
30 ax25_ds_establish_data_link(ax25);
31}
32
33/*
34 * dl1bke 960114: transmit I frames on DAMA poll
35 */
36void ax25_ds_enquiry_response(ax25_cb *ax25)
37{
38 ax25_cb *ax25o;
39
40 /* Please note that neither DK4EG's nor DG2FEF's
41 * DAMA spec mention the following behaviour as seen
42 * with TheFirmware:
43 *
44 * DB0ACH->DL1BKE <RR C P R0> [DAMA]
45 * DL1BKE->DB0ACH <I NR=0 NS=0>
46 * DL1BKE-7->DB0PRA-6 DB0ACH <I C S3 R5>
47 * DL1BKE->DB0ACH <RR R F R0>
48 *
49 * The Flexnet DAMA Master implementation apparently
50 * insists on the "proper" AX.25 behaviour:
51 *
52 * DB0ACH->DL1BKE <RR C P R0> [DAMA]
53 * DL1BKE->DB0ACH <RR R F R0>
54 * DL1BKE->DB0ACH <I NR=0 NS=0>
55 * DL1BKE-7->DB0PRA-6 DB0ACH <I C S3 R5>
56 *
57 * Flexnet refuses to send us *any* I frame if we send
58 * a REJ in case AX25_COND_REJECT is set. It is superfluous in
59 * this mode anyway (a RR or RNR invokes the retransmission).
60 * Is this a Flexnet bug?
61 */
62
63 ax25_std_enquiry_response(ax25);
64
65 if (!(ax25->condition & AX25_COND_PEER_RX_BUSY)) {
66 ax25_requeue_frames(ax25);
67 ax25_kick(ax25);
68 }
69
70 if (ax25->state == AX25_STATE_1 || ax25->state == AX25_STATE_2 || skb_peek(&ax25->ack_queue) != NULL)
71 ax25_ds_t1_timeout(ax25);
72 else
73 ax25->n2count = 0;
74
75 ax25_start_t3timer(ax25);
76 ax25_ds_set_timer(ax25->ax25_dev);
77
78 spin_lock(&ax25_list_lock);
79 ax25_for_each(ax25o, &ax25_list) {
80 if (ax25o == ax25)
81 continue;
82
83 if (ax25o->ax25_dev != ax25->ax25_dev)
84 continue;
85
86 if (ax25o->state == AX25_STATE_1 || ax25o->state == AX25_STATE_2) {
87 ax25_ds_t1_timeout(ax25o);
88 continue;
89 }
90
91 if (!(ax25o->condition & AX25_COND_PEER_RX_BUSY) && ax25o->state == AX25_STATE_3) {
92 ax25_requeue_frames(ax25o);
93 ax25_kick(ax25o);
94 }
95
96 if (ax25o->state == AX25_STATE_1 || ax25o->state == AX25_STATE_2 || skb_peek(&ax25o->ack_queue) != NULL)
97 ax25_ds_t1_timeout(ax25o);
98
99 /* do not start T3 for listening sockets (tnx DD8NE) */
100
101 if (ax25o->state != AX25_STATE_0)
102 ax25_start_t3timer(ax25o);
103 }
104 spin_unlock(&ax25_list_lock);
105}
106
107void ax25_ds_establish_data_link(ax25_cb *ax25)
108{
109 ax25->condition &= AX25_COND_DAMA_MODE;
110 ax25->n2count = 0;
111 ax25_calculate_t1(ax25);
112 ax25_start_t1timer(ax25);
113 ax25_stop_t2timer(ax25);
114 ax25_start_t3timer(ax25);
115}
116
117/*
118 * :::FIXME:::
119 * This is a kludge. Not all drivers recognize kiss commands.
120 * We need a driver level request to switch duplex mode, that does
121 * either SCC changing, PI config or KISS as required. Currently
122 * this request isn't reliable.
123 */
124static void ax25_kiss_cmd(ax25_dev *ax25_dev, unsigned char cmd, unsigned char param)
125{
126 struct sk_buff *skb;
127 unsigned char *p;
128
129 if (ax25_dev->dev == NULL)
130 return;
131
132 if ((skb = alloc_skb(2, GFP_ATOMIC)) == NULL)
133 return;
134
135 skb_reset_network_header(skb);
136 p = skb_put(skb, 2);
137
138 *p++ = cmd;
139 *p++ = param;
140
141 skb->protocol = ax25_type_trans(skb, ax25_dev->dev);
142
143 dev_queue_xmit(skb);
144}
145
146/*
147 * A nasty problem arises if we count the number of DAMA connections
148 * wrong, especially when connections on the device already existed
149 * and our network node (or the sysop) decides to turn on DAMA Master
150 * mode. We thus flag the 'real' slave connections with
151 * ax25->dama_slave=1 and look on every disconnect if still slave
152 * connections exist.
153 */
154static int ax25_check_dama_slave(ax25_dev *ax25_dev)
155{
156 ax25_cb *ax25;
157 int res = 0;
158
159 spin_lock(&ax25_list_lock);
160 ax25_for_each(ax25, &ax25_list)
161 if (ax25->ax25_dev == ax25_dev && (ax25->condition & AX25_COND_DAMA_MODE) && ax25->state > AX25_STATE_1) {
162 res = 1;
163 break;
164 }
165 spin_unlock(&ax25_list_lock);
166
167 return res;
168}
169
170static void ax25_dev_dama_on(ax25_dev *ax25_dev)
171{
172 if (ax25_dev == NULL)
173 return;
174
175 if (ax25_dev->dama.slave == 0)
176 ax25_kiss_cmd(ax25_dev, 5, 1);
177
178 ax25_dev->dama.slave = 1;
179 ax25_ds_set_timer(ax25_dev);
180}
181
182void ax25_dev_dama_off(ax25_dev *ax25_dev)
183{
184 if (ax25_dev == NULL)
185 return;
186
187 if (ax25_dev->dama.slave && !ax25_check_dama_slave(ax25_dev)) {
188 ax25_kiss_cmd(ax25_dev, 5, 0);
189 ax25_dev->dama.slave = 0;
190 ax25_ds_del_timer(ax25_dev);
191 }
192}
193
194void ax25_dama_on(ax25_cb *ax25)
195{
196 ax25_dev_dama_on(ax25->ax25_dev);
197 ax25->condition |= AX25_COND_DAMA_MODE;
198}
199
200void ax25_dama_off(ax25_cb *ax25)
201{
202 ax25->condition &= ~AX25_COND_DAMA_MODE;
203 ax25_dev_dama_off(ax25->ax25_dev);
204}