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 */
9 #include <linux/errno.h>
10 #include <linux/types.h>
11 #include <linux/socket.h>
12 #include <linux/in.h>
13 #include <linux/kernel.h>
14 #include <linux/jiffies.h>
15 #include <linux/timer.h>
16 #include <linux/string.h>
17 #include <linux/sockios.h>
18 #include <linux/net.h>
19 #include <linux/slab.h>
20 #include <net/ax25.h>
21 #include <linux/inet.h>
22 #include <linux/netdevice.h>
23 #include <linux/skbuff.h>
24 #include <net/sock.h>
25 #include <asm/system.h>
26 #include <linux/fcntl.h>
27 #include <linux/mm.h>
28 #include <linux/interrupt.h>
29 #include <linux/netfilter.h>
30 #include <net/rose.h>
31
32 static void rose_ftimer_expiry(unsigned long);
33 static void rose_t0timer_expiry(unsigned long);
34
35 static void rose_transmit_restart_confirmation(struct rose_neigh *neigh);
36 static void rose_transmit_restart_request(struct rose_neigh *neigh);
37
rose_start_ftimer(struct rose_neigh * neigh)38 void rose_start_ftimer(struct rose_neigh *neigh)
39 {
40 del_timer(&neigh->ftimer);
41
42 neigh->ftimer.data = (unsigned long)neigh;
43 neigh->ftimer.function = &rose_ftimer_expiry;
44 neigh->ftimer.expires =
45 jiffies + msecs_to_jiffies(sysctl_rose_link_fail_timeout);
46
47 add_timer(&neigh->ftimer);
48 }
49
rose_start_t0timer(struct rose_neigh * neigh)50 static void rose_start_t0timer(struct rose_neigh *neigh)
51 {
52 del_timer(&neigh->t0timer);
53
54 neigh->t0timer.data = (unsigned long)neigh;
55 neigh->t0timer.function = &rose_t0timer_expiry;
56 neigh->t0timer.expires =
57 jiffies + msecs_to_jiffies(sysctl_rose_restart_request_timeout);
58
59 add_timer(&neigh->t0timer);
60 }
61
rose_stop_ftimer(struct rose_neigh * neigh)62 void rose_stop_ftimer(struct rose_neigh *neigh)
63 {
64 del_timer(&neigh->ftimer);
65 }
66
rose_stop_t0timer(struct rose_neigh * neigh)67 void rose_stop_t0timer(struct rose_neigh *neigh)
68 {
69 del_timer(&neigh->t0timer);
70 }
71
rose_ftimer_running(struct rose_neigh * neigh)72 int rose_ftimer_running(struct rose_neigh *neigh)
73 {
74 return timer_pending(&neigh->ftimer);
75 }
76
rose_t0timer_running(struct rose_neigh * neigh)77 static int rose_t0timer_running(struct rose_neigh *neigh)
78 {
79 return timer_pending(&neigh->t0timer);
80 }
81
rose_ftimer_expiry(unsigned long param)82 static void rose_ftimer_expiry(unsigned long param)
83 {
84 }
85
rose_t0timer_expiry(unsigned long param)86 static void rose_t0timer_expiry(unsigned long param)
87 {
88 struct rose_neigh *neigh = (struct rose_neigh *)param;
89
90 rose_transmit_restart_request(neigh);
91
92 neigh->dce_mode = 0;
93
94 rose_start_t0timer(neigh);
95 }
96
97 /*
98 * Interface to ax25_send_frame. Changes my level 2 callsign depending
99 * on whether we have a global ROSE callsign or use the default port
100 * callsign.
101 */
rose_send_frame(struct sk_buff * skb,struct rose_neigh * neigh)102 static int rose_send_frame(struct sk_buff *skb, struct rose_neigh *neigh)
103 {
104 ax25_address *rose_call;
105 ax25_cb *ax25s;
106
107 if (ax25cmp(&rose_callsign, &null_ax25_address) == 0)
108 rose_call = (ax25_address *)neigh->dev->dev_addr;
109 else
110 rose_call = &rose_callsign;
111
112 ax25s = neigh->ax25;
113 neigh->ax25 = ax25_send_frame(skb, 260, rose_call, &neigh->callsign, neigh->digipeat, neigh->dev);
114 if (ax25s)
115 ax25_cb_put(ax25s);
116
117 return neigh->ax25 != NULL;
118 }
119
120 /*
121 * Interface to ax25_link_up. Changes my level 2 callsign depending
122 * on whether we have a global ROSE callsign or use the default port
123 * callsign.
124 */
rose_link_up(struct rose_neigh * neigh)125 static int rose_link_up(struct rose_neigh *neigh)
126 {
127 ax25_address *rose_call;
128 ax25_cb *ax25s;
129
130 if (ax25cmp(&rose_callsign, &null_ax25_address) == 0)
131 rose_call = (ax25_address *)neigh->dev->dev_addr;
132 else
133 rose_call = &rose_callsign;
134
135 ax25s = neigh->ax25;
136 neigh->ax25 = ax25_find_cb(rose_call, &neigh->callsign, neigh->digipeat, neigh->dev);
137 if (ax25s)
138 ax25_cb_put(ax25s);
139
140 return neigh->ax25 != NULL;
141 }
142
143 /*
144 * This handles all restart and diagnostic frames.
145 */
rose_link_rx_restart(struct sk_buff * skb,struct rose_neigh * neigh,unsigned short frametype)146 void rose_link_rx_restart(struct sk_buff *skb, struct rose_neigh *neigh, unsigned short frametype)
147 {
148 struct sk_buff *skbn;
149
150 switch (frametype) {
151 case ROSE_RESTART_REQUEST:
152 rose_stop_t0timer(neigh);
153 neigh->restarted = 1;
154 neigh->dce_mode = (skb->data[3] == ROSE_DTE_ORIGINATED);
155 rose_transmit_restart_confirmation(neigh);
156 break;
157
158 case ROSE_RESTART_CONFIRMATION:
159 rose_stop_t0timer(neigh);
160 neigh->restarted = 1;
161 break;
162
163 case ROSE_DIAGNOSTIC:
164 printk(KERN_WARNING "ROSE: received diagnostic #%d - %02X %02X %02X\n", skb->data[3], skb->data[4], skb->data[5], skb->data[6]);
165 break;
166
167 default:
168 printk(KERN_WARNING "ROSE: received unknown %02X with LCI 000\n", frametype);
169 break;
170 }
171
172 if (neigh->restarted) {
173 while ((skbn = skb_dequeue(&neigh->queue)) != NULL)
174 if (!rose_send_frame(skbn, neigh))
175 kfree_skb(skbn);
176 }
177 }
178
179 /*
180 * This routine is called when a Restart Request is needed
181 */
rose_transmit_restart_request(struct rose_neigh * neigh)182 static void rose_transmit_restart_request(struct rose_neigh *neigh)
183 {
184 struct sk_buff *skb;
185 unsigned char *dptr;
186 int len;
187
188 len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 3;
189
190 if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
191 return;
192
193 skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN);
194
195 dptr = skb_put(skb, ROSE_MIN_LEN + 3);
196
197 *dptr++ = AX25_P_ROSE;
198 *dptr++ = ROSE_GFI;
199 *dptr++ = 0x00;
200 *dptr++ = ROSE_RESTART_REQUEST;
201 *dptr++ = ROSE_DTE_ORIGINATED;
202 *dptr++ = 0;
203
204 if (!rose_send_frame(skb, neigh))
205 kfree_skb(skb);
206 }
207
208 /*
209 * This routine is called when a Restart Confirmation is needed
210 */
rose_transmit_restart_confirmation(struct rose_neigh * neigh)211 static void rose_transmit_restart_confirmation(struct rose_neigh *neigh)
212 {
213 struct sk_buff *skb;
214 unsigned char *dptr;
215 int len;
216
217 len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 1;
218
219 if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
220 return;
221
222 skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN);
223
224 dptr = skb_put(skb, ROSE_MIN_LEN + 1);
225
226 *dptr++ = AX25_P_ROSE;
227 *dptr++ = ROSE_GFI;
228 *dptr++ = 0x00;
229 *dptr++ = ROSE_RESTART_CONFIRMATION;
230
231 if (!rose_send_frame(skb, neigh))
232 kfree_skb(skb);
233 }
234
235 /*
236 * This routine is called when a Clear Request is needed outside of the context
237 * of a connected socket.
238 */
rose_transmit_clear_request(struct rose_neigh * neigh,unsigned int lci,unsigned char cause,unsigned char diagnostic)239 void rose_transmit_clear_request(struct rose_neigh *neigh, unsigned int lci, unsigned char cause, unsigned char diagnostic)
240 {
241 struct sk_buff *skb;
242 unsigned char *dptr;
243 int len;
244
245 len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 3;
246
247 if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
248 return;
249
250 skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN);
251
252 dptr = skb_put(skb, ROSE_MIN_LEN + 3);
253
254 *dptr++ = AX25_P_ROSE;
255 *dptr++ = ((lci >> 8) & 0x0F) | ROSE_GFI;
256 *dptr++ = ((lci >> 0) & 0xFF);
257 *dptr++ = ROSE_CLEAR_REQUEST;
258 *dptr++ = cause;
259 *dptr++ = diagnostic;
260
261 if (!rose_send_frame(skb, neigh))
262 kfree_skb(skb);
263 }
264
rose_transmit_link(struct sk_buff * skb,struct rose_neigh * neigh)265 void rose_transmit_link(struct sk_buff *skb, struct rose_neigh *neigh)
266 {
267 unsigned char *dptr;
268
269 #if 0
270 if (call_fw_firewall(PF_ROSE, skb->dev, skb->data, NULL, &skb) != FW_ACCEPT) {
271 kfree_skb(skb);
272 return;
273 }
274 #endif
275
276 if (neigh->loopback) {
277 rose_loopback_queue(skb, neigh);
278 return;
279 }
280
281 if (!rose_link_up(neigh))
282 neigh->restarted = 0;
283
284 dptr = skb_push(skb, 1);
285 *dptr++ = AX25_P_ROSE;
286
287 if (neigh->restarted) {
288 if (!rose_send_frame(skb, neigh))
289 kfree_skb(skb);
290 } else {
291 skb_queue_tail(&neigh->queue, skb);
292
293 if (!rose_t0timer_running(neigh)) {
294 rose_transmit_restart_request(neigh);
295 neigh->dce_mode = 0;
296 rose_start_t0timer(neigh);
297 }
298 }
299 }
300