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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 <asm/uaccess.h>
27#include <asm/system.h>
28#include <linux/fcntl.h>
29#include <linux/mm.h>
30#include <linux/interrupt.h>
31
32void ax25_ds_nr_error_recovery(ax25_cb *ax25)
33{
34 ax25_ds_establish_data_link(ax25);
35}
36
37/*
38 * dl1bke 960114: transmit I frames on DAMA poll
39 */
40void ax25_ds_enquiry_response(ax25_cb *ax25)
41{
42 ax25_cb *ax25o;
43 struct hlist_node *node;
44
45 /* Please note that neither DK4EG's nor DG2FEF's
46 * DAMA spec mention the following behaviour as seen
47 * with TheFirmware:
48 *
49 * DB0ACH->DL1BKE <RR C P R0> [DAMA]
50 * DL1BKE->DB0ACH <I NR=0 NS=0>
51 * DL1BKE-7->DB0PRA-6 DB0ACH <I C S3 R5>
52 * DL1BKE->DB0ACH <RR R F R0>
53 *
54 * The Flexnet DAMA Master implementation apparently
55 * insists on the "proper" AX.25 behaviour:
56 *
57 * DB0ACH->DL1BKE <RR C P R0> [DAMA]
58 * DL1BKE->DB0ACH <RR R F R0>
59 * DL1BKE->DB0ACH <I NR=0 NS=0>
60 * DL1BKE-7->DB0PRA-6 DB0ACH <I C S3 R5>
61 *
62 * Flexnet refuses to send us *any* I frame if we send
63 * a REJ in case AX25_COND_REJECT is set. It is superfluous in
64 * this mode anyway (a RR or RNR invokes the retransmission).
65 * Is this a Flexnet bug?
66 */
67
68 ax25_std_enquiry_response(ax25);
69
70 if (!(ax25->condition & AX25_COND_PEER_RX_BUSY)) {
71 ax25_requeue_frames(ax25);
72 ax25_kick(ax25);
73 }
74
75 if (ax25->state == AX25_STATE_1 || ax25->state == AX25_STATE_2 || skb_peek(&ax25->ack_queue) != NULL)
76 ax25_ds_t1_timeout(ax25);
77 else
78 ax25->n2count = 0;
79
80 ax25_start_t3timer(ax25);
81 ax25_ds_set_timer(ax25->ax25_dev);
82
83 spin_lock(&ax25_list_lock);
84 ax25_for_each(ax25o, node, &ax25_list) {
85 if (ax25o == ax25)
86 continue;
87
88 if (ax25o->ax25_dev != ax25->ax25_dev)
89 continue;
90
91 if (ax25o->state == AX25_STATE_1 || ax25o->state == AX25_STATE_2) {
92 ax25_ds_t1_timeout(ax25o);
93 continue;
94 }
95
96 if (!(ax25o->condition & AX25_COND_PEER_RX_BUSY) && ax25o->state == AX25_STATE_3) {
97 ax25_requeue_frames(ax25o);
98 ax25_kick(ax25o);
99 }
100
101 if (ax25o->state == AX25_STATE_1 || ax25o->state == AX25_STATE_2 || skb_peek(&ax25o->ack_queue) != NULL)
102 ax25_ds_t1_timeout(ax25o);
103
104 /* do not start T3 for listening sockets (tnx DD8NE) */
105
106 if (ax25o->state != AX25_STATE_0)
107 ax25_start_t3timer(ax25o);
108 }
109 spin_unlock(&ax25_list_lock);
110}
111
112void ax25_ds_establish_data_link(ax25_cb *ax25)
113{
114 ax25->condition &= AX25_COND_DAMA_MODE;
115 ax25->n2count = 0;
116 ax25_calculate_t1(ax25);
117 ax25_start_t1timer(ax25);
118 ax25_stop_t2timer(ax25);
119 ax25_start_t3timer(ax25);
120}
121
122/*
123 * :::FIXME:::
124 * This is a kludge. Not all drivers recognize kiss commands.
125 * We need a driver level request to switch duplex mode, that does
126 * either SCC changing, PI config or KISS as required. Currently
127 * this request isn't reliable.
128 */
129static void ax25_kiss_cmd(ax25_dev *ax25_dev, unsigned char cmd, unsigned char param)
130{
131 struct sk_buff *skb;
132 unsigned char *p;
133
134 if (ax25_dev->dev == NULL)
135 return;
136
137 if ((skb = alloc_skb(2, GFP_ATOMIC)) == NULL)
138 return;
139
140 skb_reset_network_header(skb);
141 p = skb_put(skb, 2);
142
143 *p++ = cmd;
144 *p++ = param;
145
146 skb->protocol = ax25_type_trans(skb, ax25_dev->dev);
147
148 dev_queue_xmit(skb);
149}
150
151/*
152 * A nasty problem arises if we count the number of DAMA connections
153 * wrong, especially when connections on the device already existed
154 * and our network node (or the sysop) decides to turn on DAMA Master
155 * mode. We thus flag the 'real' slave connections with
156 * ax25->dama_slave=1 and look on every disconnect if still slave
157 * connections exist.
158 */
159static int ax25_check_dama_slave(ax25_dev *ax25_dev)
160{
161 ax25_cb *ax25;
162 int res = 0;
163 struct hlist_node *node;
164
165 spin_lock(&ax25_list_lock);
166 ax25_for_each(ax25, node, &ax25_list)
167 if (ax25->ax25_dev == ax25_dev && (ax25->condition & AX25_COND_DAMA_MODE) && ax25->state > AX25_STATE_1) {
168 res = 1;
169 break;
170 }
171 spin_unlock(&ax25_list_lock);
172
173 return res;
174}
175
176static void ax25_dev_dama_on(ax25_dev *ax25_dev)
177{
178 if (ax25_dev == NULL)
179 return;
180
181 if (ax25_dev->dama.slave == 0)
182 ax25_kiss_cmd(ax25_dev, 5, 1);
183
184 ax25_dev->dama.slave = 1;
185 ax25_ds_set_timer(ax25_dev);
186}
187
188void ax25_dev_dama_off(ax25_dev *ax25_dev)
189{
190 if (ax25_dev == NULL)
191 return;
192
193 if (ax25_dev->dama.slave && !ax25_check_dama_slave(ax25_dev)) {
194 ax25_kiss_cmd(ax25_dev, 5, 0);
195 ax25_dev->dama.slave = 0;
196 ax25_ds_del_timer(ax25_dev);
197 }
198}
199
200void ax25_dama_on(ax25_cb *ax25)
201{
202 ax25_dev_dama_on(ax25->ax25_dev);
203 ax25->condition |= AX25_COND_DAMA_MODE;
204}
205
206void ax25_dama_off(ax25_cb *ax25)
207{
208 ax25->condition &= ~AX25_COND_DAMA_MODE;
209 ax25_dev_dama_off(ax25->ax25_dev);
210}
211
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}