xref: /openbmc/linux/net/rose/rose_subr.c (revision 1da177e4)
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/sched.h>
15 #include <linux/timer.h>
16 #include <linux/string.h>
17 #include <linux/sockios.h>
18 #include <linux/net.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.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  */
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  */
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 
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);
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  */
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  */
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++ = 0xAA;
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 
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 
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 			p   += 2;
250 			n   += 2;
251 			len -= 2;
252 			break;
253 
254 		case 0x40:
255 			if (*p == FAC_NATIONAL_RAND)
256 				facilities->rand = ((p[1] << 8) & 0xFF00) + ((p[2] << 0) & 0x00FF);
257 			p   += 3;
258 			n   += 3;
259 			len -= 3;
260 			break;
261 
262 		case 0x80:
263 			p   += 4;
264 			n   += 4;
265 			len -= 4;
266 			break;
267 
268 		case 0xC0:
269 			l = p[1];
270 			if (*p == FAC_NATIONAL_DEST_DIGI) {
271 				if (!fac_national_digis_received) {
272 					memcpy(&facilities->source_digis[0], p + 2, AX25_ADDR_LEN);
273 					facilities->source_ndigis = 1;
274 				}
275 			}
276 			else if (*p == FAC_NATIONAL_SRC_DIGI) {
277 				if (!fac_national_digis_received) {
278 					memcpy(&facilities->dest_digis[0], p + 2, AX25_ADDR_LEN);
279 					facilities->dest_ndigis = 1;
280 				}
281 			}
282 			else if (*p == FAC_NATIONAL_FAIL_CALL) {
283 				memcpy(&facilities->fail_call, p + 2, AX25_ADDR_LEN);
284 			}
285 			else if (*p == FAC_NATIONAL_FAIL_ADD) {
286 				memcpy(&facilities->fail_addr, p + 3, ROSE_ADDR_LEN);
287 			}
288 			else if (*p == FAC_NATIONAL_DIGIS) {
289 				fac_national_digis_received = 1;
290 				facilities->source_ndigis = 0;
291 				facilities->dest_ndigis   = 0;
292 				for (pt = p + 2, lg = 0 ; lg < l ; pt += AX25_ADDR_LEN, lg += AX25_ADDR_LEN) {
293 					if (pt[6] & AX25_HBIT)
294 						memcpy(&facilities->dest_digis[facilities->dest_ndigis++], pt, AX25_ADDR_LEN);
295 					else
296 						memcpy(&facilities->source_digis[facilities->source_ndigis++], pt, AX25_ADDR_LEN);
297 				}
298 			}
299 			p   += l + 2;
300 			n   += l + 2;
301 			len -= l + 2;
302 			break;
303 		}
304 	} while (*p != 0x00 && len > 0);
305 
306 	return n;
307 }
308 
309 static int rose_parse_ccitt(unsigned char *p, struct rose_facilities_struct *facilities, int len)
310 {
311 	unsigned char l, n = 0;
312 	char callsign[11];
313 
314 	do {
315 		switch (*p & 0xC0) {
316 		case 0x00:
317 			p   += 2;
318 			n   += 2;
319 			len -= 2;
320 			break;
321 
322 		case 0x40:
323 			p   += 3;
324 			n   += 3;
325 			len -= 3;
326 			break;
327 
328 		case 0x80:
329 			p   += 4;
330 			n   += 4;
331 			len -= 4;
332 			break;
333 
334 		case 0xC0:
335 			l = p[1];
336 			if (*p == FAC_CCITT_DEST_NSAP) {
337 				memcpy(&facilities->source_addr, p + 7, ROSE_ADDR_LEN);
338 				memcpy(callsign, p + 12,   l - 10);
339 				callsign[l - 10] = '\0';
340 				facilities->source_call = *asc2ax(callsign);
341 			}
342 			if (*p == FAC_CCITT_SRC_NSAP) {
343 				memcpy(&facilities->dest_addr, p + 7, ROSE_ADDR_LEN);
344 				memcpy(callsign, p + 12, l - 10);
345 				callsign[l - 10] = '\0';
346 				facilities->dest_call = *asc2ax(callsign);
347 			}
348 			p   += l + 2;
349 			n   += l + 2;
350 			len -= l + 2;
351 			break;
352 		}
353 	} while (*p != 0x00 && len > 0);
354 
355 	return n;
356 }
357 
358 int rose_parse_facilities(unsigned char *p,
359 	struct rose_facilities_struct *facilities)
360 {
361 	int facilities_len, len;
362 
363 	facilities_len = *p++;
364 
365 	if (facilities_len == 0)
366 		return 0;
367 
368 	while (facilities_len > 0) {
369 		if (*p == 0x00) {
370 			facilities_len--;
371 			p++;
372 
373 			switch (*p) {
374 			case FAC_NATIONAL:		/* National */
375 				len = rose_parse_national(p + 1, facilities, facilities_len - 1);
376 				facilities_len -= len + 1;
377 				p += len + 1;
378 				break;
379 
380 			case FAC_CCITT:		/* CCITT */
381 				len = rose_parse_ccitt(p + 1, facilities, facilities_len - 1);
382 				facilities_len -= len + 1;
383 				p += len + 1;
384 				break;
385 
386 			default:
387 				printk(KERN_DEBUG "ROSE: rose_parse_facilities - unknown facilities family %02X\n", *p);
388 				facilities_len--;
389 				p++;
390 				break;
391 			}
392 		} else
393 			break;	/* Error in facilities format */
394 	}
395 
396 	return 1;
397 }
398 
399 static int rose_create_facilities(unsigned char *buffer, struct rose_sock *rose)
400 {
401 	unsigned char *p = buffer + 1;
402 	char *callsign;
403 	int len, nb;
404 
405 	/* National Facilities */
406 	if (rose->rand != 0 || rose->source_ndigis == 1 || rose->dest_ndigis == 1) {
407 		*p++ = 0x00;
408 		*p++ = FAC_NATIONAL;
409 
410 		if (rose->rand != 0) {
411 			*p++ = FAC_NATIONAL_RAND;
412 			*p++ = (rose->rand >> 8) & 0xFF;
413 			*p++ = (rose->rand >> 0) & 0xFF;
414 		}
415 
416 		/* Sent before older facilities */
417 		if ((rose->source_ndigis > 0) || (rose->dest_ndigis > 0)) {
418 			int maxdigi = 0;
419 			*p++ = FAC_NATIONAL_DIGIS;
420 			*p++ = AX25_ADDR_LEN * (rose->source_ndigis + rose->dest_ndigis);
421 			for (nb = 0 ; nb < rose->source_ndigis ; nb++) {
422 				if (++maxdigi >= ROSE_MAX_DIGIS)
423 					break;
424 				memcpy(p, &rose->source_digis[nb], AX25_ADDR_LEN);
425 				p[6] |= AX25_HBIT;
426 				p += AX25_ADDR_LEN;
427 			}
428 			for (nb = 0 ; nb < rose->dest_ndigis ; nb++) {
429 				if (++maxdigi >= ROSE_MAX_DIGIS)
430 					break;
431 				memcpy(p, &rose->dest_digis[nb], AX25_ADDR_LEN);
432 				p[6] &= ~AX25_HBIT;
433 				p += AX25_ADDR_LEN;
434 			}
435 		}
436 
437 		/* For compatibility */
438 		if (rose->source_ndigis > 0) {
439 			*p++ = FAC_NATIONAL_SRC_DIGI;
440 			*p++ = AX25_ADDR_LEN;
441 			memcpy(p, &rose->source_digis[0], AX25_ADDR_LEN);
442 			p   += AX25_ADDR_LEN;
443 		}
444 
445 		/* For compatibility */
446 		if (rose->dest_ndigis > 0) {
447 			*p++ = FAC_NATIONAL_DEST_DIGI;
448 			*p++ = AX25_ADDR_LEN;
449 			memcpy(p, &rose->dest_digis[0], AX25_ADDR_LEN);
450 			p   += AX25_ADDR_LEN;
451 		}
452 	}
453 
454 	*p++ = 0x00;
455 	*p++ = FAC_CCITT;
456 
457 	*p++ = FAC_CCITT_DEST_NSAP;
458 
459 	callsign = ax2asc(&rose->dest_call);
460 
461 	*p++ = strlen(callsign) + 10;
462 	*p++ = (strlen(callsign) + 9) * 2;		/* ??? */
463 
464 	*p++ = 0x47; *p++ = 0x00; *p++ = 0x11;
465 	*p++ = ROSE_ADDR_LEN * 2;
466 	memcpy(p, &rose->dest_addr, ROSE_ADDR_LEN);
467 	p   += ROSE_ADDR_LEN;
468 
469 	memcpy(p, callsign, strlen(callsign));
470 	p   += strlen(callsign);
471 
472 	*p++ = FAC_CCITT_SRC_NSAP;
473 
474 	callsign = ax2asc(&rose->source_call);
475 
476 	*p++ = strlen(callsign) + 10;
477 	*p++ = (strlen(callsign) + 9) * 2;		/* ??? */
478 
479 	*p++ = 0x47; *p++ = 0x00; *p++ = 0x11;
480 	*p++ = ROSE_ADDR_LEN * 2;
481 	memcpy(p, &rose->source_addr, ROSE_ADDR_LEN);
482 	p   += ROSE_ADDR_LEN;
483 
484 	memcpy(p, callsign, strlen(callsign));
485 	p   += strlen(callsign);
486 
487 	len       = p - buffer;
488 	buffer[0] = len - 1;
489 
490 	return len;
491 }
492 
493 void rose_disconnect(struct sock *sk, int reason, int cause, int diagnostic)
494 {
495 	struct rose_sock *rose = rose_sk(sk);
496 
497 	rose_stop_timer(sk);
498 	rose_stop_idletimer(sk);
499 
500 	rose_clear_queues(sk);
501 
502 	rose->lci   = 0;
503 	rose->state = ROSE_STATE_0;
504 
505 	if (cause != -1)
506 		rose->cause = cause;
507 
508 	if (diagnostic != -1)
509 		rose->diagnostic = diagnostic;
510 
511 	sk->sk_state     = TCP_CLOSE;
512 	sk->sk_err       = reason;
513 	sk->sk_shutdown |= SEND_SHUTDOWN;
514 
515 	if (!sock_flag(sk, SOCK_DEAD)) {
516 		sk->sk_state_change(sk);
517 		sock_set_flag(sk, SOCK_DEAD);
518 	}
519 }
520