1 /*
2 * X.25 Packet Layer release 002
3 *
4 * This is ALPHA test software. This code may break your machine, randomly fail to work with new
5 * releases, misbehave and/or generally screw up. It might even work.
6 *
7 * This code REQUIRES 2.1.15 or higher
8 *
9 * This module:
10 * This module is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version
13 * 2 of the License, or (at your option) any later version.
14 *
15 * History
16 * X.25 001 Jonathan Naylor Started coding.
17 * X.25 002 Jonathan Naylor New timer architecture.
18 * mar/20/00 Daniela Squassoni Disabling/enabling of facilities
19 * negotiation.
20 * 2000-09-04 Henner Eisen dev_hold() / dev_put() for x25_neigh.
21 */
22
23 #include <linux/errno.h>
24 #include <linux/types.h>
25 #include <linux/socket.h>
26 #include <linux/in.h>
27 #include <linux/kernel.h>
28 #include <linux/sched.h>
29 #include <linux/timer.h>
30 #include <linux/string.h>
31 #include <linux/sockios.h>
32 #include <linux/net.h>
33 #include <linux/inet.h>
34 #include <linux/netdevice.h>
35 #include <linux/skbuff.h>
36 #include <net/sock.h>
37 #include <asm/segment.h>
38 #include <asm/system.h>
39 #include <asm/uaccess.h>
40 #include <linux/fcntl.h>
41 #include <linux/mm.h>
42 #include <linux/interrupt.h>
43 #include <linux/init.h>
44 #include <net/x25.h>
45
46 static struct x25_neigh *x25_neigh_list /* = NULL initially */;
47
48 static void x25_t20timer_expiry(unsigned long);
49
50 /*
51 * Linux set/reset timer routines
52 */
x25_start_t20timer(struct x25_neigh * neigh)53 static void x25_start_t20timer(struct x25_neigh *neigh)
54 {
55 del_timer(&neigh->t20timer);
56
57 neigh->t20timer.data = (unsigned long)neigh;
58 neigh->t20timer.function = &x25_t20timer_expiry;
59 neigh->t20timer.expires = jiffies + neigh->t20;
60
61 add_timer(&neigh->t20timer);
62 }
63
x25_t20timer_expiry(unsigned long param)64 static void x25_t20timer_expiry(unsigned long param)
65 {
66 struct x25_neigh *neigh = (struct x25_neigh *)param;
67
68 x25_transmit_restart_request(neigh);
69
70 x25_start_t20timer(neigh);
71 }
72
x25_stop_t20timer(struct x25_neigh * neigh)73 static void x25_stop_t20timer(struct x25_neigh *neigh)
74 {
75 del_timer(&neigh->t20timer);
76 }
77
x25_t20timer_pending(struct x25_neigh * neigh)78 static int x25_t20timer_pending(struct x25_neigh *neigh)
79 {
80 return timer_pending(&neigh->t20timer);
81 }
82
83 /*
84 * This handles all restart and diagnostic frames.
85 */
x25_link_control(struct sk_buff * skb,struct x25_neigh * neigh,unsigned short frametype)86 void x25_link_control(struct sk_buff *skb, struct x25_neigh *neigh, unsigned short frametype)
87 {
88 struct sk_buff *skbn;
89 int confirm;
90
91 switch (frametype) {
92 case X25_RESTART_REQUEST:
93 confirm = !x25_t20timer_pending(neigh);
94 x25_stop_t20timer(neigh);
95 neigh->state = X25_LINK_STATE_3;
96 if (confirm) x25_transmit_restart_confirmation(neigh);
97 break;
98
99 case X25_RESTART_CONFIRMATION:
100 x25_stop_t20timer(neigh);
101 neigh->state = X25_LINK_STATE_3;
102 break;
103
104 case X25_DIAGNOSTIC:
105 printk(KERN_WARNING "x25: diagnostic #%d - %02X %02X %02X\n", skb->data[3], skb->data[4], skb->data[5], skb->data[6]);
106 break;
107
108 default:
109 printk(KERN_WARNING "x25: received unknown %02X with LCI 000\n", frametype);
110 break;
111 }
112
113 if (neigh->state == X25_LINK_STATE_3) {
114 while ((skbn = skb_dequeue(&neigh->queue)) != NULL)
115 x25_send_frame(skbn, neigh);
116 }
117 }
118
119 /*
120 * This routine is called when a Restart Request is needed
121 */
x25_transmit_restart_request(struct x25_neigh * neigh)122 void x25_transmit_restart_request(struct x25_neigh *neigh)
123 {
124 struct sk_buff *skb;
125 unsigned char *dptr;
126 int len;
127
128 len = X25_MAX_L2_LEN + X25_STD_MIN_LEN + 2;
129
130 if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
131 return;
132
133 skb_reserve(skb, X25_MAX_L2_LEN);
134
135 dptr = skb_put(skb, X25_STD_MIN_LEN + 2);
136
137 *dptr++ = (neigh->extended) ? X25_GFI_EXTSEQ : X25_GFI_STDSEQ;
138 *dptr++ = 0x00;
139 *dptr++ = X25_RESTART_REQUEST;
140 *dptr++ = 0x00;
141 *dptr++ = 0;
142
143 skb->sk = NULL;
144
145 x25_send_frame(skb, neigh);
146 }
147
148 /*
149 * This routine is called when a Restart Confirmation is needed
150 */
x25_transmit_restart_confirmation(struct x25_neigh * neigh)151 void x25_transmit_restart_confirmation(struct x25_neigh *neigh)
152 {
153 struct sk_buff *skb;
154 unsigned char *dptr;
155 int len;
156
157 len = X25_MAX_L2_LEN + X25_STD_MIN_LEN;
158
159 if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
160 return;
161
162 skb_reserve(skb, X25_MAX_L2_LEN);
163
164 dptr = skb_put(skb, X25_STD_MIN_LEN);
165
166 *dptr++ = (neigh->extended) ? X25_GFI_EXTSEQ : X25_GFI_STDSEQ;
167 *dptr++ = 0x00;
168 *dptr++ = X25_RESTART_CONFIRMATION;
169
170 skb->sk = NULL;
171
172 x25_send_frame(skb, neigh);
173 }
174
175 /*
176 * This routine is called when a Diagnostic is required.
177 */
x25_transmit_diagnostic(struct x25_neigh * neigh,unsigned char diag)178 void x25_transmit_diagnostic(struct x25_neigh *neigh, unsigned char diag)
179 {
180 struct sk_buff *skb;
181 unsigned char *dptr;
182 int len;
183
184 len = X25_MAX_L2_LEN + X25_STD_MIN_LEN + 1;
185
186 if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
187 return;
188
189 skb_reserve(skb, X25_MAX_L2_LEN);
190
191 dptr = skb_put(skb, X25_STD_MIN_LEN + 1);
192
193 *dptr++ = (neigh->extended) ? X25_GFI_EXTSEQ : X25_GFI_STDSEQ;
194 *dptr++ = 0x00;
195 *dptr++ = X25_DIAGNOSTIC;
196 *dptr++ = diag;
197
198 skb->sk = NULL;
199
200 x25_send_frame(skb, neigh);
201 }
202
203 /*
204 * This routine is called when a Clear Request is needed outside of the context
205 * of a connected socket.
206 */
x25_transmit_clear_request(struct x25_neigh * neigh,unsigned int lci,unsigned char cause)207 void x25_transmit_clear_request(struct x25_neigh *neigh, unsigned int lci, unsigned char cause)
208 {
209 struct sk_buff *skb;
210 unsigned char *dptr;
211 int len;
212
213 len = X25_MAX_L2_LEN + X25_STD_MIN_LEN + 2;
214
215 if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
216 return;
217
218 skb_reserve(skb, X25_MAX_L2_LEN);
219
220 dptr = skb_put(skb, X25_STD_MIN_LEN + 2);
221
222 *dptr++ = ((lci >> 8) & 0x0F) | (neigh->extended ? X25_GFI_EXTSEQ : X25_GFI_STDSEQ);
223 *dptr++ = ((lci >> 0) & 0xFF);
224 *dptr++ = X25_CLEAR_REQUEST;
225 *dptr++ = cause;
226 *dptr++ = 0x00;
227
228 skb->sk = NULL;
229
230 x25_send_frame(skb, neigh);
231 }
232
x25_transmit_link(struct sk_buff * skb,struct x25_neigh * neigh)233 void x25_transmit_link(struct sk_buff *skb, struct x25_neigh *neigh)
234 {
235 switch (neigh->state) {
236 case X25_LINK_STATE_0:
237 skb_queue_tail(&neigh->queue, skb);
238 neigh->state = X25_LINK_STATE_1;
239 x25_establish_link(neigh);
240 break;
241 case X25_LINK_STATE_1:
242 case X25_LINK_STATE_2:
243 skb_queue_tail(&neigh->queue, skb);
244 break;
245 case X25_LINK_STATE_3:
246 x25_send_frame(skb, neigh);
247 break;
248 }
249 }
250
251 /*
252 * Called when the link layer has become established.
253 */
x25_link_established(struct x25_neigh * neigh)254 void x25_link_established(struct x25_neigh *neigh)
255 {
256 switch (neigh->state) {
257 case X25_LINK_STATE_0:
258 neigh->state = X25_LINK_STATE_2;
259 break;
260 case X25_LINK_STATE_1:
261 x25_transmit_restart_request(neigh);
262 neigh->state = X25_LINK_STATE_2;
263 x25_start_t20timer(neigh);
264 break;
265 }
266 }
267
268 /*
269 * Called when the link layer has terminated, or an establishment
270 * request has failed.
271 */
272
x25_link_terminated(struct x25_neigh * neigh)273 void x25_link_terminated(struct x25_neigh *neigh)
274 {
275 neigh->state = X25_LINK_STATE_0;
276 /* Out of order: clear existing virtual calls (X.25 03/93 4.6.3) */
277 x25_kill_by_neigh(neigh);
278 }
279
280 /*
281 * Add a new device.
282 */
x25_link_device_up(struct net_device * dev)283 void x25_link_device_up(struct net_device *dev)
284 {
285 struct x25_neigh *x25_neigh;
286 unsigned long flags;
287
288 if ((x25_neigh = kmalloc(sizeof(*x25_neigh), GFP_ATOMIC)) == NULL)
289 return;
290
291 skb_queue_head_init(&x25_neigh->queue);
292
293 init_timer(&x25_neigh->t20timer);
294
295 dev_hold(dev);
296 x25_neigh->dev = dev;
297 x25_neigh->state = X25_LINK_STATE_0;
298 x25_neigh->extended = 0;
299 x25_neigh->global_facil_mask = (X25_MASK_REVERSE | X25_MASK_THROUGHPUT | X25_MASK_PACKET_SIZE | X25_MASK_WINDOW_SIZE); /* enables negotiation */
300 x25_neigh->t20 = sysctl_x25_restart_request_timeout;
301
302 save_flags(flags); cli();
303 x25_neigh->next = x25_neigh_list;
304 x25_neigh_list = x25_neigh;
305 restore_flags(flags);
306 }
307
x25_remove_neigh(struct x25_neigh * x25_neigh)308 static void x25_remove_neigh(struct x25_neigh *x25_neigh)
309 {
310 struct x25_neigh *s;
311 unsigned long flags;
312
313 skb_queue_purge(&x25_neigh->queue);
314
315 x25_stop_t20timer(x25_neigh);
316
317 save_flags(flags); cli();
318
319 if ((s = x25_neigh_list) == x25_neigh) {
320 x25_neigh_list = x25_neigh->next;
321 restore_flags(flags);
322 kfree(x25_neigh);
323 return;
324 }
325
326 while (s != NULL && s->next != NULL) {
327 if (s->next == x25_neigh) {
328 s->next = x25_neigh->next;
329 restore_flags(flags);
330 kfree(x25_neigh);
331 return;
332 }
333
334 s = s->next;
335 }
336
337 restore_flags(flags);
338 }
339
340 /*
341 * A device has been removed, remove its links.
342 */
x25_link_device_down(struct net_device * dev)343 void x25_link_device_down(struct net_device *dev)
344 {
345 struct x25_neigh *neigh, *x25_neigh = x25_neigh_list;
346
347 while (x25_neigh != NULL) {
348 neigh = x25_neigh;
349 x25_neigh = x25_neigh->next;
350
351 if (neigh->dev == dev){
352 x25_remove_neigh(neigh);
353 dev_put(dev);
354 }
355 }
356 }
357
358 /*
359 * Given a device, return the neighbour address.
360 */
x25_get_neigh(struct net_device * dev)361 struct x25_neigh *x25_get_neigh(struct net_device *dev)
362 {
363 struct x25_neigh *x25_neigh;
364
365 for (x25_neigh = x25_neigh_list; x25_neigh != NULL; x25_neigh = x25_neigh->next)
366 if (x25_neigh->dev == dev)
367 return x25_neigh;
368
369 return NULL;
370 }
371
372 /*
373 * Handle the ioctls that control the subscription functions.
374 */
x25_subscr_ioctl(unsigned int cmd,void * arg)375 int x25_subscr_ioctl(unsigned int cmd, void *arg)
376 {
377 struct x25_subscrip_struct x25_subscr;
378 struct x25_neigh *x25_neigh;
379 struct net_device *dev;
380
381 switch (cmd) {
382
383 case SIOCX25GSUBSCRIP:
384 if (copy_from_user(&x25_subscr, arg, sizeof(struct x25_subscrip_struct)))
385 return -EFAULT;
386 if ((dev = x25_dev_get(x25_subscr.device)) == NULL)
387 return -EINVAL;
388 if ((x25_neigh = x25_get_neigh(dev)) == NULL) {
389 dev_put(dev);
390 return -EINVAL;
391 }
392 dev_put(dev);
393 x25_subscr.extended = x25_neigh->extended;
394 x25_subscr.global_facil_mask = x25_neigh->global_facil_mask;
395 if (copy_to_user(arg, &x25_subscr, sizeof(struct x25_subscrip_struct)))
396 return -EFAULT;
397 break;
398
399 case SIOCX25SSUBSCRIP:
400 if (copy_from_user(&x25_subscr, arg, sizeof(struct x25_subscrip_struct)))
401 return -EFAULT;
402 if ((dev = x25_dev_get(x25_subscr.device)) == NULL)
403 return -EINVAL;
404 if ((x25_neigh = x25_get_neigh(dev)) == NULL) {
405 dev_put(dev);
406 return -EINVAL;
407 }
408 dev_put(dev);
409 if (x25_subscr.extended != 0 && x25_subscr.extended != 1)
410 return -EINVAL;
411 x25_neigh->extended = x25_subscr.extended;
412 x25_neigh->global_facil_mask = x25_subscr.global_facil_mask;
413 break;
414
415 default:
416 return -EINVAL;
417 }
418
419 return 0;
420 }
421
422
423 /*
424 * Release all memory associated with X.25 neighbour structures.
425 */
x25_link_free(void)426 void __exit x25_link_free(void)
427 {
428 struct x25_neigh *neigh, *x25_neigh = x25_neigh_list;
429
430 while (x25_neigh != NULL) {
431 neigh = x25_neigh;
432 x25_neigh = x25_neigh->next;
433
434 x25_remove_neigh(neigh);
435 }
436 }
437