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/timer.h>
15 #include <linux/string.h>
16 #include <linux/sockios.h>
17 #include <linux/net.h>
18 #include <linux/slab.h>
19 #include <net/ax25.h>
20 #include <linux/inet.h>
21 #include <linux/netdevice.h>
22 #include <linux/skbuff.h>
23 #include <net/sock.h>
24 #include <net/tcp_states.h>
25 #include <asm/system.h>
26 #include <linux/fcntl.h>
27 #include <linux/mm.h>
28 #include <linux/interrupt.h>
29 #include <net/rose.h>
30
31 static int rose_create_facilities(unsigned char *buffer, struct rose_sock *rose);
32
33 /*
34 * This routine purges all of the queues of frames.
35 */
rose_clear_queues(struct sock * sk)36 void rose_clear_queues(struct sock *sk)
37 {
38 skb_queue_purge(&sk->sk_write_queue);
39 skb_queue_purge(&rose_sk(sk)->ack_queue);
40 }
41
42 /*
43 * This routine purges the input queue of those frames that have been
44 * acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the
45 * SDL diagram.
46 */
rose_frames_acked(struct sock * sk,unsigned short nr)47 void rose_frames_acked(struct sock *sk, unsigned short nr)
48 {
49 struct sk_buff *skb;
50 struct rose_sock *rose = rose_sk(sk);
51
52 /*
53 * Remove all the ack-ed frames from the ack queue.
54 */
55 if (rose->va != nr) {
56 while (skb_peek(&rose->ack_queue) != NULL && rose->va != nr) {
57 skb = skb_dequeue(&rose->ack_queue);
58 kfree_skb(skb);
59 rose->va = (rose->va + 1) % ROSE_MODULUS;
60 }
61 }
62 }
63
rose_requeue_frames(struct sock * sk)64 void rose_requeue_frames(struct sock *sk)
65 {
66 struct sk_buff *skb, *skb_prev = NULL;
67
68 /*
69 * Requeue all the un-ack-ed frames on the output queue to be picked
70 * up by rose_kick. This arrangement handles the possibility of an
71 * empty output queue.
72 */
73 while ((skb = skb_dequeue(&rose_sk(sk)->ack_queue)) != NULL) {
74 if (skb_prev == NULL)
75 skb_queue_head(&sk->sk_write_queue, skb);
76 else
77 skb_append(skb_prev, skb, &sk->sk_write_queue);
78 skb_prev = skb;
79 }
80 }
81
82 /*
83 * Validate that the value of nr is between va and vs. Return true or
84 * false for testing.
85 */
rose_validate_nr(struct sock * sk,unsigned short nr)86 int rose_validate_nr(struct sock *sk, unsigned short nr)
87 {
88 struct rose_sock *rose = rose_sk(sk);
89 unsigned short vc = rose->va;
90
91 while (vc != rose->vs) {
92 if (nr == vc) return 1;
93 vc = (vc + 1) % ROSE_MODULUS;
94 }
95
96 return nr == rose->vs;
97 }
98
99 /*
100 * This routine is called when the packet layer internally generates a
101 * control frame.
102 */
rose_write_internal(struct sock * sk,int frametype)103 void rose_write_internal(struct sock *sk, int frametype)
104 {
105 struct rose_sock *rose = rose_sk(sk);
106 struct sk_buff *skb;
107 unsigned char *dptr;
108 unsigned char lci1, lci2;
109 char buffer[100];
110 int len, faclen = 0;
111
112 len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 1;
113
114 switch (frametype) {
115 case ROSE_CALL_REQUEST:
116 len += 1 + ROSE_ADDR_LEN + ROSE_ADDR_LEN;
117 faclen = rose_create_facilities(buffer, rose);
118 len += faclen;
119 break;
120 case ROSE_CALL_ACCEPTED:
121 case ROSE_CLEAR_REQUEST:
122 case ROSE_RESET_REQUEST:
123 len += 2;
124 break;
125 }
126
127 if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
128 return;
129
130 /*
131 * Space for AX.25 header and PID.
132 */
133 skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + 1);
134
135 dptr = skb_put(skb, skb_tailroom(skb));
136
137 lci1 = (rose->lci >> 8) & 0x0F;
138 lci2 = (rose->lci >> 0) & 0xFF;
139
140 switch (frametype) {
141 case ROSE_CALL_REQUEST:
142 *dptr++ = ROSE_GFI | lci1;
143 *dptr++ = lci2;
144 *dptr++ = frametype;
145 *dptr++ = ROSE_CALL_REQ_ADDR_LEN_VAL;
146 memcpy(dptr, &rose->dest_addr, ROSE_ADDR_LEN);
147 dptr += ROSE_ADDR_LEN;
148 memcpy(dptr, &rose->source_addr, ROSE_ADDR_LEN);
149 dptr += ROSE_ADDR_LEN;
150 memcpy(dptr, buffer, faclen);
151 dptr += faclen;
152 break;
153
154 case ROSE_CALL_ACCEPTED:
155 *dptr++ = ROSE_GFI | lci1;
156 *dptr++ = lci2;
157 *dptr++ = frametype;
158 *dptr++ = 0x00; /* Address length */
159 *dptr++ = 0; /* Facilities length */
160 break;
161
162 case ROSE_CLEAR_REQUEST:
163 *dptr++ = ROSE_GFI | lci1;
164 *dptr++ = lci2;
165 *dptr++ = frametype;
166 *dptr++ = rose->cause;
167 *dptr++ = rose->diagnostic;
168 break;
169
170 case ROSE_RESET_REQUEST:
171 *dptr++ = ROSE_GFI | lci1;
172 *dptr++ = lci2;
173 *dptr++ = frametype;
174 *dptr++ = ROSE_DTE_ORIGINATED;
175 *dptr++ = 0;
176 break;
177
178 case ROSE_RR:
179 case ROSE_RNR:
180 *dptr++ = ROSE_GFI | lci1;
181 *dptr++ = lci2;
182 *dptr = frametype;
183 *dptr++ |= (rose->vr << 5) & 0xE0;
184 break;
185
186 case ROSE_CLEAR_CONFIRMATION:
187 case ROSE_RESET_CONFIRMATION:
188 *dptr++ = ROSE_GFI | lci1;
189 *dptr++ = lci2;
190 *dptr++ = frametype;
191 break;
192
193 default:
194 printk(KERN_ERR "ROSE: rose_write_internal - invalid frametype %02X\n", frametype);
195 kfree_skb(skb);
196 return;
197 }
198
199 rose_transmit_link(skb, rose->neighbour);
200 }
201
rose_decode(struct sk_buff * skb,int * ns,int * nr,int * q,int * d,int * m)202 int rose_decode(struct sk_buff *skb, int *ns, int *nr, int *q, int *d, int *m)
203 {
204 unsigned char *frame;
205
206 frame = skb->data;
207
208 *ns = *nr = *q = *d = *m = 0;
209
210 switch (frame[2]) {
211 case ROSE_CALL_REQUEST:
212 case ROSE_CALL_ACCEPTED:
213 case ROSE_CLEAR_REQUEST:
214 case ROSE_CLEAR_CONFIRMATION:
215 case ROSE_RESET_REQUEST:
216 case ROSE_RESET_CONFIRMATION:
217 return frame[2];
218 default:
219 break;
220 }
221
222 if ((frame[2] & 0x1F) == ROSE_RR ||
223 (frame[2] & 0x1F) == ROSE_RNR) {
224 *nr = (frame[2] >> 5) & 0x07;
225 return frame[2] & 0x1F;
226 }
227
228 if ((frame[2] & 0x01) == ROSE_DATA) {
229 *q = (frame[0] & ROSE_Q_BIT) == ROSE_Q_BIT;
230 *d = (frame[0] & ROSE_D_BIT) == ROSE_D_BIT;
231 *m = (frame[2] & ROSE_M_BIT) == ROSE_M_BIT;
232 *nr = (frame[2] >> 5) & 0x07;
233 *ns = (frame[2] >> 1) & 0x07;
234 return ROSE_DATA;
235 }
236
237 return ROSE_ILLEGAL;
238 }
239
rose_parse_national(unsigned char * p,struct rose_facilities_struct * facilities,int len)240 static int rose_parse_national(unsigned char *p, struct rose_facilities_struct *facilities, int len)
241 {
242 unsigned char *pt;
243 unsigned char l, lg, n = 0;
244 int fac_national_digis_received = 0;
245
246 do {
247 switch (*p & 0xC0) {
248 case 0x00:
249 if (len < 2)
250 return -1;
251 p += 2;
252 n += 2;
253 len -= 2;
254 break;
255
256 case 0x40:
257 if (len < 3)
258 return -1;
259 if (*p == FAC_NATIONAL_RAND)
260 facilities->rand = ((p[1] << 8) & 0xFF00) + ((p[2] << 0) & 0x00FF);
261 p += 3;
262 n += 3;
263 len -= 3;
264 break;
265
266 case 0x80:
267 if (len < 4)
268 return -1;
269 p += 4;
270 n += 4;
271 len -= 4;
272 break;
273
274 case 0xC0:
275 if (len < 2)
276 return -1;
277 l = p[1];
278 if (len < 2 + l)
279 return -1;
280 if (*p == FAC_NATIONAL_DEST_DIGI) {
281 if (!fac_national_digis_received) {
282 if (l < AX25_ADDR_LEN)
283 return -1;
284 memcpy(&facilities->source_digis[0], p + 2, AX25_ADDR_LEN);
285 facilities->source_ndigis = 1;
286 }
287 }
288 else if (*p == FAC_NATIONAL_SRC_DIGI) {
289 if (!fac_national_digis_received) {
290 if (l < AX25_ADDR_LEN)
291 return -1;
292 memcpy(&facilities->dest_digis[0], p + 2, AX25_ADDR_LEN);
293 facilities->dest_ndigis = 1;
294 }
295 }
296 else if (*p == FAC_NATIONAL_FAIL_CALL) {
297 if (l < AX25_ADDR_LEN)
298 return -1;
299 memcpy(&facilities->fail_call, p + 2, AX25_ADDR_LEN);
300 }
301 else if (*p == FAC_NATIONAL_FAIL_ADD) {
302 if (l < 1 + ROSE_ADDR_LEN)
303 return -1;
304 memcpy(&facilities->fail_addr, p + 3, ROSE_ADDR_LEN);
305 }
306 else if (*p == FAC_NATIONAL_DIGIS) {
307 if (l % AX25_ADDR_LEN)
308 return -1;
309 fac_national_digis_received = 1;
310 facilities->source_ndigis = 0;
311 facilities->dest_ndigis = 0;
312 for (pt = p + 2, lg = 0 ; lg < l ; pt += AX25_ADDR_LEN, lg += AX25_ADDR_LEN) {
313 if (pt[6] & AX25_HBIT) {
314 if (facilities->dest_ndigis >= ROSE_MAX_DIGIS)
315 return -1;
316 memcpy(&facilities->dest_digis[facilities->dest_ndigis++], pt, AX25_ADDR_LEN);
317 } else {
318 if (facilities->source_ndigis >= ROSE_MAX_DIGIS)
319 return -1;
320 memcpy(&facilities->source_digis[facilities->source_ndigis++], pt, AX25_ADDR_LEN);
321 }
322 }
323 }
324 p += l + 2;
325 n += l + 2;
326 len -= l + 2;
327 break;
328 }
329 } while (*p != 0x00 && len > 0);
330
331 return n;
332 }
333
rose_parse_ccitt(unsigned char * p,struct rose_facilities_struct * facilities,int len)334 static int rose_parse_ccitt(unsigned char *p, struct rose_facilities_struct *facilities, int len)
335 {
336 unsigned char l, n = 0;
337 char callsign[11];
338
339 do {
340 switch (*p & 0xC0) {
341 case 0x00:
342 if (len < 2)
343 return -1;
344 p += 2;
345 n += 2;
346 len -= 2;
347 break;
348
349 case 0x40:
350 if (len < 3)
351 return -1;
352 p += 3;
353 n += 3;
354 len -= 3;
355 break;
356
357 case 0x80:
358 if (len < 4)
359 return -1;
360 p += 4;
361 n += 4;
362 len -= 4;
363 break;
364
365 case 0xC0:
366 if (len < 2)
367 return -1;
368 l = p[1];
369
370 /* Prevent overflows*/
371 if (l < 10 || l > 20)
372 return -1;
373
374 if (*p == FAC_CCITT_DEST_NSAP) {
375 memcpy(&facilities->source_addr, p + 7, ROSE_ADDR_LEN);
376 memcpy(callsign, p + 12, l - 10);
377 callsign[l - 10] = '\0';
378 asc2ax(&facilities->source_call, callsign);
379 }
380 if (*p == FAC_CCITT_SRC_NSAP) {
381 memcpy(&facilities->dest_addr, p + 7, ROSE_ADDR_LEN);
382 memcpy(callsign, p + 12, l - 10);
383 callsign[l - 10] = '\0';
384 asc2ax(&facilities->dest_call, callsign);
385 }
386 p += l + 2;
387 n += l + 2;
388 len -= l + 2;
389 break;
390 }
391 } while (*p != 0x00 && len > 0);
392
393 return n;
394 }
395
rose_parse_facilities(unsigned char * p,unsigned packet_len,struct rose_facilities_struct * facilities)396 int rose_parse_facilities(unsigned char *p, unsigned packet_len,
397 struct rose_facilities_struct *facilities)
398 {
399 int facilities_len, len;
400
401 facilities_len = *p++;
402
403 if (facilities_len == 0 || (unsigned)facilities_len > packet_len)
404 return 0;
405
406 while (facilities_len >= 3 && *p == 0x00) {
407 facilities_len--;
408 p++;
409
410 switch (*p) {
411 case FAC_NATIONAL: /* National */
412 len = rose_parse_national(p + 1, facilities, facilities_len - 1);
413 break;
414
415 case FAC_CCITT: /* CCITT */
416 len = rose_parse_ccitt(p + 1, facilities, facilities_len - 1);
417 break;
418
419 default:
420 printk(KERN_DEBUG "ROSE: rose_parse_facilities - unknown facilities family %02X\n", *p);
421 len = 1;
422 break;
423 }
424
425 if (len < 0)
426 return 0;
427 if (WARN_ON(len >= facilities_len))
428 return 0;
429 facilities_len -= len + 1;
430 p += len + 1;
431 }
432
433 return facilities_len == 0;
434 }
435
rose_create_facilities(unsigned char * buffer,struct rose_sock * rose)436 static int rose_create_facilities(unsigned char *buffer, struct rose_sock *rose)
437 {
438 unsigned char *p = buffer + 1;
439 char *callsign;
440 char buf[11];
441 int len, nb;
442
443 /* National Facilities */
444 if (rose->rand != 0 || rose->source_ndigis == 1 || rose->dest_ndigis == 1) {
445 *p++ = 0x00;
446 *p++ = FAC_NATIONAL;
447
448 if (rose->rand != 0) {
449 *p++ = FAC_NATIONAL_RAND;
450 *p++ = (rose->rand >> 8) & 0xFF;
451 *p++ = (rose->rand >> 0) & 0xFF;
452 }
453
454 /* Sent before older facilities */
455 if ((rose->source_ndigis > 0) || (rose->dest_ndigis > 0)) {
456 int maxdigi = 0;
457 *p++ = FAC_NATIONAL_DIGIS;
458 *p++ = AX25_ADDR_LEN * (rose->source_ndigis + rose->dest_ndigis);
459 for (nb = 0 ; nb < rose->source_ndigis ; nb++) {
460 if (++maxdigi >= ROSE_MAX_DIGIS)
461 break;
462 memcpy(p, &rose->source_digis[nb], AX25_ADDR_LEN);
463 p[6] |= AX25_HBIT;
464 p += AX25_ADDR_LEN;
465 }
466 for (nb = 0 ; nb < rose->dest_ndigis ; nb++) {
467 if (++maxdigi >= ROSE_MAX_DIGIS)
468 break;
469 memcpy(p, &rose->dest_digis[nb], AX25_ADDR_LEN);
470 p[6] &= ~AX25_HBIT;
471 p += AX25_ADDR_LEN;
472 }
473 }
474
475 /* For compatibility */
476 if (rose->source_ndigis > 0) {
477 *p++ = FAC_NATIONAL_SRC_DIGI;
478 *p++ = AX25_ADDR_LEN;
479 memcpy(p, &rose->source_digis[0], AX25_ADDR_LEN);
480 p += AX25_ADDR_LEN;
481 }
482
483 /* For compatibility */
484 if (rose->dest_ndigis > 0) {
485 *p++ = FAC_NATIONAL_DEST_DIGI;
486 *p++ = AX25_ADDR_LEN;
487 memcpy(p, &rose->dest_digis[0], AX25_ADDR_LEN);
488 p += AX25_ADDR_LEN;
489 }
490 }
491
492 *p++ = 0x00;
493 *p++ = FAC_CCITT;
494
495 *p++ = FAC_CCITT_DEST_NSAP;
496
497 callsign = ax2asc(buf, &rose->dest_call);
498
499 *p++ = strlen(callsign) + 10;
500 *p++ = (strlen(callsign) + 9) * 2; /* ??? */
501
502 *p++ = 0x47; *p++ = 0x00; *p++ = 0x11;
503 *p++ = ROSE_ADDR_LEN * 2;
504 memcpy(p, &rose->dest_addr, ROSE_ADDR_LEN);
505 p += ROSE_ADDR_LEN;
506
507 memcpy(p, callsign, strlen(callsign));
508 p += strlen(callsign);
509
510 *p++ = FAC_CCITT_SRC_NSAP;
511
512 callsign = ax2asc(buf, &rose->source_call);
513
514 *p++ = strlen(callsign) + 10;
515 *p++ = (strlen(callsign) + 9) * 2; /* ??? */
516
517 *p++ = 0x47; *p++ = 0x00; *p++ = 0x11;
518 *p++ = ROSE_ADDR_LEN * 2;
519 memcpy(p, &rose->source_addr, ROSE_ADDR_LEN);
520 p += ROSE_ADDR_LEN;
521
522 memcpy(p, callsign, strlen(callsign));
523 p += strlen(callsign);
524
525 len = p - buffer;
526 buffer[0] = len - 1;
527
528 return len;
529 }
530
rose_disconnect(struct sock * sk,int reason,int cause,int diagnostic)531 void rose_disconnect(struct sock *sk, int reason, int cause, int diagnostic)
532 {
533 struct rose_sock *rose = rose_sk(sk);
534
535 rose_stop_timer(sk);
536 rose_stop_idletimer(sk);
537
538 rose_clear_queues(sk);
539
540 rose->lci = 0;
541 rose->state = ROSE_STATE_0;
542
543 if (cause != -1)
544 rose->cause = cause;
545
546 if (diagnostic != -1)
547 rose->diagnostic = diagnostic;
548
549 sk->sk_state = TCP_CLOSE;
550 sk->sk_err = reason;
551 sk->sk_shutdown |= SEND_SHUTDOWN;
552
553 if (!sock_flag(sk, SOCK_DEAD)) {
554 sk->sk_state_change(sk);
555 sock_set_flag(sk, SOCK_DEAD);
556 }
557 }
558