Commit | Line | Data |
---|---|---|
2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1da177e4 | 2 | /* |
1da177e4 LT |
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> | |
1da177e4 LT |
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> | |
5a0e3ad6 | 17 | #include <linux/gfp.h> |
1da177e4 LT |
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> | |
7c0f6ba6 | 23 | #include <linux/uaccess.h> |
1da177e4 LT |
24 | #include <linux/fcntl.h> |
25 | #include <linux/mm.h> | |
26 | #include <linux/interrupt.h> | |
27 | ||
28 | void 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 | */ | |
36 | void ax25_ds_enquiry_response(ax25_cb *ax25) | |
37 | { | |
38 | ax25_cb *ax25o; | |
1da177e4 | 39 | |
96de0e25 | 40 | /* Please note that neither DK4EG's nor DG2FEF's |
1da177e4 LT |
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 | ||
c19c4b9c | 78 | spin_lock(&ax25_list_lock); |
b67bfe0d | 79 | ax25_for_each(ax25o, &ax25_list) { |
1da177e4 LT |
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 | } | |
c19c4b9c | 104 | spin_unlock(&ax25_list_lock); |
1da177e4 LT |
105 | } |
106 | ||
107 | void 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 | */ | |
124 | static 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 | ||
c1d2bbe1 | 135 | skb_reset_network_header(skb); |
1da177e4 LT |
136 | p = skb_put(skb, 2); |
137 | ||
138 | *p++ = cmd; | |
139 | *p++ = param; | |
140 | ||
56cb5156 | 141 | skb->protocol = ax25_type_trans(skb, ax25_dev->dev); |
1da177e4 LT |
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 | */ | |
154 | static int ax25_check_dama_slave(ax25_dev *ax25_dev) | |
155 | { | |
156 | ax25_cb *ax25; | |
157 | int res = 0; | |
1da177e4 | 158 | |
c19c4b9c | 159 | spin_lock(&ax25_list_lock); |
b67bfe0d | 160 | ax25_for_each(ax25, &ax25_list) |
1da177e4 LT |
161 | if (ax25->ax25_dev == ax25_dev && (ax25->condition & AX25_COND_DAMA_MODE) && ax25->state > AX25_STATE_1) { |
162 | res = 1; | |
163 | break; | |
164 | } | |
c19c4b9c | 165 | spin_unlock(&ax25_list_lock); |
1da177e4 LT |
166 | |
167 | return res; | |
168 | } | |
169 | ||
170 | static 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 | ||
182 | void 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 | ||
194 | void ax25_dama_on(ax25_cb *ax25) | |
195 | { | |
196 | ax25_dev_dama_on(ax25->ax25_dev); | |
197 | ax25->condition |= AX25_COND_DAMA_MODE; | |
198 | } | |
199 | ||
200 | void ax25_dama_off(ax25_cb *ax25) | |
201 | { | |
202 | ax25->condition &= ~AX25_COND_DAMA_MODE; | |
203 | ax25_dev_dama_off(ax25->ax25_dev); | |
204 | } |