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>
21 #include <linux/inet.h>
22 #include <linux/netdevice.h>
23 #include <linux/skbuff.h>
25 #include <asm/uaccess.h>
26 #include <asm/system.h>
27 #include <linux/fcntl.h>
29 #include <linux/interrupt.h>
31 void ax25_ds_nr_error_recovery(ax25_cb *ax25)
33 ax25_ds_establish_data_link(ax25);
37 * dl1bke 960114: transmit I frames on DAMA poll
39 void ax25_ds_enquiry_response(ax25_cb *ax25)
42 struct hlist_node *node;
44 /* Please note that neither DK4EG´s nor DG2FEF´s
45 * DAMA spec mention the following behaviour as seen
48 * DB0ACH->DL1BKE <RR C P R0> [DAMA]
49 * DL1BKE->DB0ACH <I NR=0 NS=0>
50 * DL1BKE-7->DB0PRA-6 DB0ACH <I C S3 R5>
51 * DL1BKE->DB0ACH <RR R F R0>
53 * The Flexnet DAMA Master implementation apparently
54 * insists on the "proper" AX.25 behaviour:
56 * DB0ACH->DL1BKE <RR C P R0> [DAMA]
57 * DL1BKE->DB0ACH <RR R F R0>
58 * DL1BKE->DB0ACH <I NR=0 NS=0>
59 * DL1BKE-7->DB0PRA-6 DB0ACH <I C S3 R5>
61 * Flexnet refuses to send us *any* I frame if we send
62 * a REJ in case AX25_COND_REJECT is set. It is superfluous in
63 * this mode anyway (a RR or RNR invokes the retransmission).
64 * Is this a Flexnet bug?
67 ax25_std_enquiry_response(ax25);
69 if (!(ax25->condition & AX25_COND_PEER_RX_BUSY)) {
70 ax25_requeue_frames(ax25);
74 if (ax25->state == AX25_STATE_1 || ax25->state == AX25_STATE_2 || skb_peek(&ax25->ack_queue) != NULL)
75 ax25_ds_t1_timeout(ax25);
79 ax25_start_t3timer(ax25);
80 ax25_ds_set_timer(ax25->ax25_dev);
82 spin_lock(&ax25_list_lock);
83 ax25_for_each(ax25o, node, &ax25_list) {
87 if (ax25o->ax25_dev != ax25->ax25_dev)
90 if (ax25o->state == AX25_STATE_1 || ax25o->state == AX25_STATE_2) {
91 ax25_ds_t1_timeout(ax25o);
95 if (!(ax25o->condition & AX25_COND_PEER_RX_BUSY) && ax25o->state == AX25_STATE_3) {
96 ax25_requeue_frames(ax25o);
100 if (ax25o->state == AX25_STATE_1 || ax25o->state == AX25_STATE_2 || skb_peek(&ax25o->ack_queue) != NULL)
101 ax25_ds_t1_timeout(ax25o);
103 /* do not start T3 for listening sockets (tnx DD8NE) */
105 if (ax25o->state != AX25_STATE_0)
106 ax25_start_t3timer(ax25o);
108 spin_unlock(&ax25_list_lock);
111 void ax25_ds_establish_data_link(ax25_cb *ax25)
113 ax25->condition &= AX25_COND_DAMA_MODE;
115 ax25_calculate_t1(ax25);
116 ax25_start_t1timer(ax25);
117 ax25_stop_t2timer(ax25);
118 ax25_start_t3timer(ax25);
123 * This is a kludge. Not all drivers recognize kiss commands.
124 * We need a driver level request to switch duplex mode, that does
125 * either SCC changing, PI config or KISS as required. Currently
126 * this request isn't reliable.
128 static void ax25_kiss_cmd(ax25_dev *ax25_dev, unsigned char cmd, unsigned char param)
133 if (ax25_dev->dev == NULL)
136 if ((skb = alloc_skb(2, GFP_ATOMIC)) == NULL)
139 skb_reset_network_header(skb);
145 skb->protocol = ax25_type_trans(skb, ax25_dev->dev);
151 * A nasty problem arises if we count the number of DAMA connections
152 * wrong, especially when connections on the device already existed
153 * and our network node (or the sysop) decides to turn on DAMA Master
154 * mode. We thus flag the 'real' slave connections with
155 * ax25->dama_slave=1 and look on every disconnect if still slave
158 static int ax25_check_dama_slave(ax25_dev *ax25_dev)
162 struct hlist_node *node;
164 spin_lock(&ax25_list_lock);
165 ax25_for_each(ax25, node, &ax25_list)
166 if (ax25->ax25_dev == ax25_dev && (ax25->condition & AX25_COND_DAMA_MODE) && ax25->state > AX25_STATE_1) {
170 spin_unlock(&ax25_list_lock);
175 static void ax25_dev_dama_on(ax25_dev *ax25_dev)
177 if (ax25_dev == NULL)
180 if (ax25_dev->dama.slave == 0)
181 ax25_kiss_cmd(ax25_dev, 5, 1);
183 ax25_dev->dama.slave = 1;
184 ax25_ds_set_timer(ax25_dev);
187 void ax25_dev_dama_off(ax25_dev *ax25_dev)
189 if (ax25_dev == NULL)
192 if (ax25_dev->dama.slave && !ax25_check_dama_slave(ax25_dev)) {
193 ax25_kiss_cmd(ax25_dev, 5, 0);
194 ax25_dev->dama.slave = 0;
195 ax25_ds_del_timer(ax25_dev);
199 void ax25_dama_on(ax25_cb *ax25)
201 ax25_dev_dama_on(ax25->ax25_dev);
202 ax25->condition |= AX25_COND_DAMA_MODE;
205 void ax25_dama_off(ax25_cb *ax25)
207 ax25->condition &= ~AX25_COND_DAMA_MODE;
208 ax25_dev_dama_off(ax25->ax25_dev);