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
31static int rose_create_facilities(unsigned char *buffer, struct rose_sock *rose);
32
33/*
34 *	This routine purges all of the queues of frames.
35 */
36void 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 */
47void 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
64void 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 */
86int 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 */
103void 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
202int 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
240static 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
309static 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				asc2ax(&facilities->source_call, 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				asc2ax(&facilities->dest_call, 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
358int 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
399static int rose_create_facilities(unsigned char *buffer, struct rose_sock *rose)
400{
401	unsigned char *p = buffer + 1;
402	char *callsign;
403	char buf[11];
404	int len, nb;
405
406	/* National Facilities */
407	if (rose->rand != 0 || rose->source_ndigis == 1 || rose->dest_ndigis == 1) {
408		*p++ = 0x00;
409		*p++ = FAC_NATIONAL;
410
411		if (rose->rand != 0) {
412			*p++ = FAC_NATIONAL_RAND;
413			*p++ = (rose->rand >> 8) & 0xFF;
414			*p++ = (rose->rand >> 0) & 0xFF;
415		}
416
417		/* Sent before older facilities */
418		if ((rose->source_ndigis > 0) || (rose->dest_ndigis > 0)) {
419			int maxdigi = 0;
420			*p++ = FAC_NATIONAL_DIGIS;
421			*p++ = AX25_ADDR_LEN * (rose->source_ndigis + rose->dest_ndigis);
422			for (nb = 0 ; nb < rose->source_ndigis ; nb++) {
423				if (++maxdigi >= ROSE_MAX_DIGIS)
424					break;
425				memcpy(p, &rose->source_digis[nb], AX25_ADDR_LEN);
426				p[6] |= AX25_HBIT;
427				p += AX25_ADDR_LEN;
428			}
429			for (nb = 0 ; nb < rose->dest_ndigis ; nb++) {
430				if (++maxdigi >= ROSE_MAX_DIGIS)
431					break;
432				memcpy(p, &rose->dest_digis[nb], AX25_ADDR_LEN);
433				p[6] &= ~AX25_HBIT;
434				p += AX25_ADDR_LEN;
435			}
436		}
437
438		/* For compatibility */
439		if (rose->source_ndigis > 0) {
440			*p++ = FAC_NATIONAL_SRC_DIGI;
441			*p++ = AX25_ADDR_LEN;
442			memcpy(p, &rose->source_digis[0], AX25_ADDR_LEN);
443			p   += AX25_ADDR_LEN;
444		}
445
446		/* For compatibility */
447		if (rose->dest_ndigis > 0) {
448			*p++ = FAC_NATIONAL_DEST_DIGI;
449			*p++ = AX25_ADDR_LEN;
450			memcpy(p, &rose->dest_digis[0], AX25_ADDR_LEN);
451			p   += AX25_ADDR_LEN;
452		}
453	}
454
455	*p++ = 0x00;
456	*p++ = FAC_CCITT;
457
458	*p++ = FAC_CCITT_DEST_NSAP;
459
460	callsign = ax2asc(buf, &rose->dest_call);
461
462	*p++ = strlen(callsign) + 10;
463	*p++ = (strlen(callsign) + 9) * 2;		/* ??? */
464
465	*p++ = 0x47; *p++ = 0x00; *p++ = 0x11;
466	*p++ = ROSE_ADDR_LEN * 2;
467	memcpy(p, &rose->dest_addr, ROSE_ADDR_LEN);
468	p   += ROSE_ADDR_LEN;
469
470	memcpy(p, callsign, strlen(callsign));
471	p   += strlen(callsign);
472
473	*p++ = FAC_CCITT_SRC_NSAP;
474
475	callsign = ax2asc(buf, &rose->source_call);
476
477	*p++ = strlen(callsign) + 10;
478	*p++ = (strlen(callsign) + 9) * 2;		/* ??? */
479
480	*p++ = 0x47; *p++ = 0x00; *p++ = 0x11;
481	*p++ = ROSE_ADDR_LEN * 2;
482	memcpy(p, &rose->source_addr, ROSE_ADDR_LEN);
483	p   += ROSE_ADDR_LEN;
484
485	memcpy(p, callsign, strlen(callsign));
486	p   += strlen(callsign);
487
488	len       = p - buffer;
489	buffer[0] = len - 1;
490
491	return len;
492}
493
494void rose_disconnect(struct sock *sk, int reason, int cause, int diagnostic)
495{
496	struct rose_sock *rose = rose_sk(sk);
497
498	rose_stop_timer(sk);
499	rose_stop_idletimer(sk);
500
501	rose_clear_queues(sk);
502
503	rose->lci   = 0;
504	rose->state = ROSE_STATE_0;
505
506	if (cause != -1)
507		rose->cause = cause;
508
509	if (diagnostic != -1)
510		rose->diagnostic = diagnostic;
511
512	sk->sk_state     = TCP_CLOSE;
513	sk->sk_err       = reason;
514	sk->sk_shutdown |= SEND_SHUTDOWN;
515
516	if (!sock_flag(sk, SOCK_DEAD)) {
517		sk->sk_state_change(sk);
518		sock_set_flag(sk, SOCK_DEAD);
519	}
520}
521