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.
7 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
8 * Copyright (C) Joerg Reuter DL1BKE (jreuter@yaina.de)
10 #include <linux/errno.h>
11 #include <linux/types.h>
12 #include <linux/socket.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>
22 #include <linux/inet.h>
23 #include <linux/netdevice.h>
24 #include <linux/skbuff.h>
26 #include <asm/uaccess.h>
27 #include <asm/system.h>
28 #include <linux/fcntl.h>
30 #include <linux/interrupt.h>
32 void ax25_ds_nr_error_recovery(ax25_cb
*ax25
)
34 ax25_ds_establish_data_link(ax25
);
38 * dl1bke 960114: transmit I frames on DAMA poll
40 void ax25_ds_enquiry_response(ax25_cb
*ax25
)
43 struct hlist_node
*node
;
45 /* Please note that neither DK4EG's nor DG2FEF's
46 * DAMA spec mention the following behaviour as seen
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>
54 * The Flexnet DAMA Master implementation apparently
55 * insists on the "proper" AX.25 behaviour:
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>
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?
68 ax25_std_enquiry_response(ax25
);
70 if (!(ax25
->condition
& AX25_COND_PEER_RX_BUSY
)) {
71 ax25_requeue_frames(ax25
);
75 if (ax25
->state
== AX25_STATE_1
|| ax25
->state
== AX25_STATE_2
|| skb_peek(&ax25
->ack_queue
) != NULL
)
76 ax25_ds_t1_timeout(ax25
);
80 ax25_start_t3timer(ax25
);
81 ax25_ds_set_timer(ax25
->ax25_dev
);
83 spin_lock(&ax25_list_lock
);
84 ax25_for_each(ax25o
, node
, &ax25_list
) {
88 if (ax25o
->ax25_dev
!= ax25
->ax25_dev
)
91 if (ax25o
->state
== AX25_STATE_1
|| ax25o
->state
== AX25_STATE_2
) {
92 ax25_ds_t1_timeout(ax25o
);
96 if (!(ax25o
->condition
& AX25_COND_PEER_RX_BUSY
) && ax25o
->state
== AX25_STATE_3
) {
97 ax25_requeue_frames(ax25o
);
101 if (ax25o
->state
== AX25_STATE_1
|| ax25o
->state
== AX25_STATE_2
|| skb_peek(&ax25o
->ack_queue
) != NULL
)
102 ax25_ds_t1_timeout(ax25o
);
104 /* do not start T3 for listening sockets (tnx DD8NE) */
106 if (ax25o
->state
!= AX25_STATE_0
)
107 ax25_start_t3timer(ax25o
);
109 spin_unlock(&ax25_list_lock
);
112 void ax25_ds_establish_data_link(ax25_cb
*ax25
)
114 ax25
->condition
&= AX25_COND_DAMA_MODE
;
116 ax25_calculate_t1(ax25
);
117 ax25_start_t1timer(ax25
);
118 ax25_stop_t2timer(ax25
);
119 ax25_start_t3timer(ax25
);
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.
129 static void ax25_kiss_cmd(ax25_dev
*ax25_dev
, unsigned char cmd
, unsigned char param
)
134 if (ax25_dev
->dev
== NULL
)
137 if ((skb
= alloc_skb(2, GFP_ATOMIC
)) == NULL
)
140 skb_reset_network_header(skb
);
146 skb
->protocol
= ax25_type_trans(skb
, ax25_dev
->dev
);
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
159 static int ax25_check_dama_slave(ax25_dev
*ax25_dev
)
163 struct hlist_node
*node
;
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
) {
171 spin_unlock(&ax25_list_lock
);
176 static void ax25_dev_dama_on(ax25_dev
*ax25_dev
)
178 if (ax25_dev
== NULL
)
181 if (ax25_dev
->dama
.slave
== 0)
182 ax25_kiss_cmd(ax25_dev
, 5, 1);
184 ax25_dev
->dama
.slave
= 1;
185 ax25_ds_set_timer(ax25_dev
);
188 void ax25_dev_dama_off(ax25_dev
*ax25_dev
)
190 if (ax25_dev
== NULL
)
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
);
200 void ax25_dama_on(ax25_cb
*ax25
)
202 ax25_dev_dama_on(ax25
->ax25_dev
);
203 ax25
->condition
|= AX25_COND_DAMA_MODE
;
206 void ax25_dama_off(ax25_cb
*ax25
)
208 ax25
->condition
&= ~AX25_COND_DAMA_MODE
;
209 ax25_dev_dama_off(ax25
->ax25_dev
);
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