xref: /openbmc/linux/net/rose/rose_subr.c (revision 384740dc)
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 <net/ax25.h>
19 #include <linux/inet.h>
20 #include <linux/netdevice.h>
21 #include <linux/skbuff.h>
22 #include <net/sock.h>
23 #include <net/tcp_states.h>
24 #include <asm/system.h>
25 #include <linux/fcntl.h>
26 #include <linux/mm.h>
27 #include <linux/interrupt.h>
28 #include <net/rose.h>
29 
30 static int rose_create_facilities(unsigned char *buffer, struct rose_sock *rose);
31 
32 /*
33  *	This routine purges all of the queues of frames.
34  */
35 void rose_clear_queues(struct sock *sk)
36 {
37 	skb_queue_purge(&sk->sk_write_queue);
38 	skb_queue_purge(&rose_sk(sk)->ack_queue);
39 }
40 
41 /*
42  * This routine purges the input queue of those frames that have been
43  * acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the
44  * SDL diagram.
45  */
46 void rose_frames_acked(struct sock *sk, unsigned short nr)
47 {
48 	struct sk_buff *skb;
49 	struct rose_sock *rose = rose_sk(sk);
50 
51 	/*
52 	 * Remove all the ack-ed frames from the ack queue.
53 	 */
54 	if (rose->va != nr) {
55 		while (skb_peek(&rose->ack_queue) != NULL && rose->va != nr) {
56 			skb = skb_dequeue(&rose->ack_queue);
57 			kfree_skb(skb);
58 			rose->va = (rose->va + 1) % ROSE_MODULUS;
59 		}
60 	}
61 }
62 
63 void rose_requeue_frames(struct sock *sk)
64 {
65 	struct sk_buff *skb, *skb_prev = NULL;
66 
67 	/*
68 	 * Requeue all the un-ack-ed frames on the output queue to be picked
69 	 * up by rose_kick. This arrangement handles the possibility of an
70 	 * empty output queue.
71 	 */
72 	while ((skb = skb_dequeue(&rose_sk(sk)->ack_queue)) != NULL) {
73 		if (skb_prev == NULL)
74 			skb_queue_head(&sk->sk_write_queue, skb);
75 		else
76 			skb_append(skb_prev, skb, &sk->sk_write_queue);
77 		skb_prev = skb;
78 	}
79 }
80 
81 /*
82  *	Validate that the value of nr is between va and vs. Return true or
83  *	false for testing.
84  */
85 int rose_validate_nr(struct sock *sk, unsigned short nr)
86 {
87 	struct rose_sock *rose = rose_sk(sk);
88 	unsigned short vc = rose->va;
89 
90 	while (vc != rose->vs) {
91 		if (nr == vc) return 1;
92 		vc = (vc + 1) % ROSE_MODULUS;
93 	}
94 
95 	return nr == rose->vs;
96 }
97 
98 /*
99  *  This routine is called when the packet layer internally generates a
100  *  control frame.
101  */
102 void rose_write_internal(struct sock *sk, int frametype)
103 {
104 	struct rose_sock *rose = rose_sk(sk);
105 	struct sk_buff *skb;
106 	unsigned char  *dptr;
107 	unsigned char  lci1, lci2;
108 	char buffer[100];
109 	int len, faclen = 0;
110 
111 	len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 1;
112 
113 	switch (frametype) {
114 	case ROSE_CALL_REQUEST:
115 		len   += 1 + ROSE_ADDR_LEN + ROSE_ADDR_LEN;
116 		faclen = rose_create_facilities(buffer, rose);
117 		len   += faclen;
118 		break;
119 	case ROSE_CALL_ACCEPTED:
120 	case ROSE_CLEAR_REQUEST:
121 	case ROSE_RESET_REQUEST:
122 		len   += 2;
123 		break;
124 	}
125 
126 	if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
127 		return;
128 
129 	/*
130 	 *	Space for AX.25 header and PID.
131 	 */
132 	skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + 1);
133 
134 	dptr = skb_put(skb, skb_tailroom(skb));
135 
136 	lci1 = (rose->lci >> 8) & 0x0F;
137 	lci2 = (rose->lci >> 0) & 0xFF;
138 
139 	switch (frametype) {
140 	case ROSE_CALL_REQUEST:
141 		*dptr++ = ROSE_GFI | lci1;
142 		*dptr++ = lci2;
143 		*dptr++ = frametype;
144 		*dptr++ = 0xAA;
145 		memcpy(dptr, &rose->dest_addr,  ROSE_ADDR_LEN);
146 		dptr   += ROSE_ADDR_LEN;
147 		memcpy(dptr, &rose->source_addr, ROSE_ADDR_LEN);
148 		dptr   += ROSE_ADDR_LEN;
149 		memcpy(dptr, buffer, faclen);
150 		dptr   += faclen;
151 		break;
152 
153 	case ROSE_CALL_ACCEPTED:
154 		*dptr++ = ROSE_GFI | lci1;
155 		*dptr++ = lci2;
156 		*dptr++ = frametype;
157 		*dptr++ = 0x00;		/* Address length */
158 		*dptr++ = 0;		/* Facilities length */
159 		break;
160 
161 	case ROSE_CLEAR_REQUEST:
162 		*dptr++ = ROSE_GFI | lci1;
163 		*dptr++ = lci2;
164 		*dptr++ = frametype;
165 		*dptr++ = rose->cause;
166 		*dptr++ = rose->diagnostic;
167 		break;
168 
169 	case ROSE_RESET_REQUEST:
170 		*dptr++ = ROSE_GFI | lci1;
171 		*dptr++ = lci2;
172 		*dptr++ = frametype;
173 		*dptr++ = ROSE_DTE_ORIGINATED;
174 		*dptr++ = 0;
175 		break;
176 
177 	case ROSE_RR:
178 	case ROSE_RNR:
179 		*dptr++ = ROSE_GFI | lci1;
180 		*dptr++ = lci2;
181 		*dptr   = frametype;
182 		*dptr++ |= (rose->vr << 5) & 0xE0;
183 		break;
184 
185 	case ROSE_CLEAR_CONFIRMATION:
186 	case ROSE_RESET_CONFIRMATION:
187 		*dptr++ = ROSE_GFI | lci1;
188 		*dptr++ = lci2;
189 		*dptr++  = frametype;
190 		break;
191 
192 	default:
193 		printk(KERN_ERR "ROSE: rose_write_internal - invalid frametype %02X\n", frametype);
194 		kfree_skb(skb);
195 		return;
196 	}
197 
198 	rose_transmit_link(skb, rose->neighbour);
199 }
200 
201 int rose_decode(struct sk_buff *skb, int *ns, int *nr, int *q, int *d, int *m)
202 {
203 	unsigned char *frame;
204 
205 	frame = skb->data;
206 
207 	*ns = *nr = *q = *d = *m = 0;
208 
209 	switch (frame[2]) {
210 	case ROSE_CALL_REQUEST:
211 	case ROSE_CALL_ACCEPTED:
212 	case ROSE_CLEAR_REQUEST:
213 	case ROSE_CLEAR_CONFIRMATION:
214 	case ROSE_RESET_REQUEST:
215 	case ROSE_RESET_CONFIRMATION:
216 		return frame[2];
217 	default:
218 		break;
219 	}
220 
221 	if ((frame[2] & 0x1F) == ROSE_RR  ||
222 	    (frame[2] & 0x1F) == ROSE_RNR) {
223 		*nr = (frame[2] >> 5) & 0x07;
224 		return frame[2] & 0x1F;
225 	}
226 
227 	if ((frame[2] & 0x01) == ROSE_DATA) {
228 		*q  = (frame[0] & ROSE_Q_BIT) == ROSE_Q_BIT;
229 		*d  = (frame[0] & ROSE_D_BIT) == ROSE_D_BIT;
230 		*m  = (frame[2] & ROSE_M_BIT) == ROSE_M_BIT;
231 		*nr = (frame[2] >> 5) & 0x07;
232 		*ns = (frame[2] >> 1) & 0x07;
233 		return ROSE_DATA;
234 	}
235 
236 	return ROSE_ILLEGAL;
237 }
238 
239 static int rose_parse_national(unsigned char *p, struct rose_facilities_struct *facilities, int len)
240 {
241 	unsigned char *pt;
242 	unsigned char l, lg, n = 0;
243 	int fac_national_digis_received = 0;
244 
245 	do {
246 		switch (*p & 0xC0) {
247 		case 0x00:
248 			p   += 2;
249 			n   += 2;
250 			len -= 2;
251 			break;
252 
253 		case 0x40:
254 			if (*p == FAC_NATIONAL_RAND)
255 				facilities->rand = ((p[1] << 8) & 0xFF00) + ((p[2] << 0) & 0x00FF);
256 			p   += 3;
257 			n   += 3;
258 			len -= 3;
259 			break;
260 
261 		case 0x80:
262 			p   += 4;
263 			n   += 4;
264 			len -= 4;
265 			break;
266 
267 		case 0xC0:
268 			l = p[1];
269 			if (*p == FAC_NATIONAL_DEST_DIGI) {
270 				if (!fac_national_digis_received) {
271 					memcpy(&facilities->source_digis[0], p + 2, AX25_ADDR_LEN);
272 					facilities->source_ndigis = 1;
273 				}
274 			}
275 			else if (*p == FAC_NATIONAL_SRC_DIGI) {
276 				if (!fac_national_digis_received) {
277 					memcpy(&facilities->dest_digis[0], p + 2, AX25_ADDR_LEN);
278 					facilities->dest_ndigis = 1;
279 				}
280 			}
281 			else if (*p == FAC_NATIONAL_FAIL_CALL) {
282 				memcpy(&facilities->fail_call, p + 2, AX25_ADDR_LEN);
283 			}
284 			else if (*p == FAC_NATIONAL_FAIL_ADD) {
285 				memcpy(&facilities->fail_addr, p + 3, ROSE_ADDR_LEN);
286 			}
287 			else if (*p == FAC_NATIONAL_DIGIS) {
288 				fac_national_digis_received = 1;
289 				facilities->source_ndigis = 0;
290 				facilities->dest_ndigis   = 0;
291 				for (pt = p + 2, lg = 0 ; lg < l ; pt += AX25_ADDR_LEN, lg += AX25_ADDR_LEN) {
292 					if (pt[6] & AX25_HBIT)
293 						memcpy(&facilities->dest_digis[facilities->dest_ndigis++], pt, AX25_ADDR_LEN);
294 					else
295 						memcpy(&facilities->source_digis[facilities->source_ndigis++], pt, AX25_ADDR_LEN);
296 				}
297 			}
298 			p   += l + 2;
299 			n   += l + 2;
300 			len -= l + 2;
301 			break;
302 		}
303 	} while (*p != 0x00 && len > 0);
304 
305 	return n;
306 }
307 
308 static int rose_parse_ccitt(unsigned char *p, struct rose_facilities_struct *facilities, int len)
309 {
310 	unsigned char l, n = 0;
311 	char callsign[11];
312 
313 	do {
314 		switch (*p & 0xC0) {
315 		case 0x00:
316 			p   += 2;
317 			n   += 2;
318 			len -= 2;
319 			break;
320 
321 		case 0x40:
322 			p   += 3;
323 			n   += 3;
324 			len -= 3;
325 			break;
326 
327 		case 0x80:
328 			p   += 4;
329 			n   += 4;
330 			len -= 4;
331 			break;
332 
333 		case 0xC0:
334 			l = p[1];
335 			if (*p == FAC_CCITT_DEST_NSAP) {
336 				memcpy(&facilities->source_addr, p + 7, ROSE_ADDR_LEN);
337 				memcpy(callsign, p + 12,   l - 10);
338 				callsign[l - 10] = '\0';
339 				asc2ax(&facilities->source_call, callsign);
340 			}
341 			if (*p == FAC_CCITT_SRC_NSAP) {
342 				memcpy(&facilities->dest_addr, p + 7, ROSE_ADDR_LEN);
343 				memcpy(callsign, p + 12, l - 10);
344 				callsign[l - 10] = '\0';
345 				asc2ax(&facilities->dest_call, callsign);
346 			}
347 			p   += l + 2;
348 			n   += l + 2;
349 			len -= l + 2;
350 			break;
351 		}
352 	} while (*p != 0x00 && len > 0);
353 
354 	return n;
355 }
356 
357 int rose_parse_facilities(unsigned char *p,
358 	struct rose_facilities_struct *facilities)
359 {
360 	int facilities_len, len;
361 
362 	facilities_len = *p++;
363 
364 	if (facilities_len == 0)
365 		return 0;
366 
367 	while (facilities_len > 0) {
368 		if (*p == 0x00) {
369 			facilities_len--;
370 			p++;
371 
372 			switch (*p) {
373 			case FAC_NATIONAL:		/* National */
374 				len = rose_parse_national(p + 1, facilities, facilities_len - 1);
375 				facilities_len -= len + 1;
376 				p += len + 1;
377 				break;
378 
379 			case FAC_CCITT:		/* CCITT */
380 				len = rose_parse_ccitt(p + 1, facilities, facilities_len - 1);
381 				facilities_len -= len + 1;
382 				p += len + 1;
383 				break;
384 
385 			default:
386 				printk(KERN_DEBUG "ROSE: rose_parse_facilities - unknown facilities family %02X\n", *p);
387 				facilities_len--;
388 				p++;
389 				break;
390 			}
391 		} else
392 			break;	/* Error in facilities format */
393 	}
394 
395 	return 1;
396 }
397 
398 static int rose_create_facilities(unsigned char *buffer, struct rose_sock *rose)
399 {
400 	unsigned char *p = buffer + 1;
401 	char *callsign;
402 	char buf[11];
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(buf, &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(buf, &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