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/jiffies.h>
15#include <linux/timer.h>
16#include <linux/string.h>
17#include <linux/sockios.h>
18#include <linux/net.h>
19#include <linux/slab.h>
20#include <net/ax25.h>
21#include <linux/inet.h>
22#include <linux/netdevice.h>
23#include <linux/skbuff.h>
24#include <net/sock.h>
25#include <asm/system.h>
26#include <linux/fcntl.h>
27#include <linux/mm.h>
28#include <linux/interrupt.h>
29#include <linux/netfilter.h>
30#include <net/rose.h>
31
32static void rose_ftimer_expiry(unsigned long);
33static void rose_t0timer_expiry(unsigned long);
34
35static void rose_transmit_restart_confirmation(struct rose_neigh *neigh);
36static void rose_transmit_restart_request(struct rose_neigh *neigh);
37
38void rose_start_ftimer(struct rose_neigh *neigh)
39{
40	del_timer(&neigh->ftimer);
41
42	neigh->ftimer.data     = (unsigned long)neigh;
43	neigh->ftimer.function = &rose_ftimer_expiry;
44	neigh->ftimer.expires  =
45		jiffies + msecs_to_jiffies(sysctl_rose_link_fail_timeout);
46
47	add_timer(&neigh->ftimer);
48}
49
50static void rose_start_t0timer(struct rose_neigh *neigh)
51{
52	del_timer(&neigh->t0timer);
53
54	neigh->t0timer.data     = (unsigned long)neigh;
55	neigh->t0timer.function = &rose_t0timer_expiry;
56	neigh->t0timer.expires  =
57		jiffies + msecs_to_jiffies(sysctl_rose_restart_request_timeout);
58
59	add_timer(&neigh->t0timer);
60}
61
62void rose_stop_ftimer(struct rose_neigh *neigh)
63{
64	del_timer(&neigh->ftimer);
65}
66
67void rose_stop_t0timer(struct rose_neigh *neigh)
68{
69	del_timer(&neigh->t0timer);
70}
71
72int rose_ftimer_running(struct rose_neigh *neigh)
73{
74	return timer_pending(&neigh->ftimer);
75}
76
77static int rose_t0timer_running(struct rose_neigh *neigh)
78{
79	return timer_pending(&neigh->t0timer);
80}
81
82static void rose_ftimer_expiry(unsigned long param)
83{
84}
85
86static void rose_t0timer_expiry(unsigned long param)
87{
88	struct rose_neigh *neigh = (struct rose_neigh *)param;
89
90	rose_transmit_restart_request(neigh);
91
92	neigh->dce_mode = 0;
93
94	rose_start_t0timer(neigh);
95}
96
97/*
98 *	Interface to ax25_send_frame. Changes my level 2 callsign depending
99 *	on whether we have a global ROSE callsign or use the default port
100 *	callsign.
101 */
102static int rose_send_frame(struct sk_buff *skb, struct rose_neigh *neigh)
103{
104	ax25_address *rose_call;
105	ax25_cb *ax25s;
106
107	if (ax25cmp(&rose_callsign, &null_ax25_address) == 0)
108		rose_call = (ax25_address *)neigh->dev->dev_addr;
109	else
110		rose_call = &rose_callsign;
111
112	ax25s = neigh->ax25;
113	neigh->ax25 = ax25_send_frame(skb, 260, rose_call, &neigh->callsign, neigh->digipeat, neigh->dev);
114	if (ax25s)
115		ax25_cb_put(ax25s);
116
117	return (neigh->ax25 != NULL);
118}
119
120/*
121 *	Interface to ax25_link_up. Changes my level 2 callsign depending
122 *	on whether we have a global ROSE callsign or use the default port
123 *	callsign.
124 */
125static int rose_link_up(struct rose_neigh *neigh)
126{
127	ax25_address *rose_call;
128	ax25_cb *ax25s;
129
130	if (ax25cmp(&rose_callsign, &null_ax25_address) == 0)
131		rose_call = (ax25_address *)neigh->dev->dev_addr;
132	else
133		rose_call = &rose_callsign;
134
135	ax25s = neigh->ax25;
136	neigh->ax25 = ax25_find_cb(rose_call, &neigh->callsign, neigh->digipeat, neigh->dev);
137	if (ax25s)
138		ax25_cb_put(ax25s);
139
140	return (neigh->ax25 != NULL);
141}
142
143/*
144 *	This handles all restart and diagnostic frames.
145 */
146void rose_link_rx_restart(struct sk_buff *skb, struct rose_neigh *neigh, unsigned short frametype)
147{
148	struct sk_buff *skbn;
149
150	switch (frametype) {
151	case ROSE_RESTART_REQUEST:
152		rose_stop_t0timer(neigh);
153		neigh->restarted = 1;
154		neigh->dce_mode  = (skb->data[3] == ROSE_DTE_ORIGINATED);
155		rose_transmit_restart_confirmation(neigh);
156		break;
157
158	case ROSE_RESTART_CONFIRMATION:
159		rose_stop_t0timer(neigh);
160		neigh->restarted = 1;
161		break;
162
163	case ROSE_DIAGNOSTIC:
164		printk(KERN_WARNING "ROSE: received diagnostic #%d - %02X %02X %02X\n", skb->data[3], skb->data[4], skb->data[5], skb->data[6]);
165		break;
166
167	default:
168		printk(KERN_WARNING "ROSE: received unknown %02X with LCI 000\n", frametype);
169		break;
170	}
171
172	if (neigh->restarted) {
173		while ((skbn = skb_dequeue(&neigh->queue)) != NULL)
174			if (!rose_send_frame(skbn, neigh))
175				kfree_skb(skbn);
176	}
177}
178
179/*
180 *	This routine is called when a Restart Request is needed
181 */
182static void rose_transmit_restart_request(struct rose_neigh *neigh)
183{
184	struct sk_buff *skb;
185	unsigned char *dptr;
186	int len;
187
188	len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 3;
189
190	if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
191		return;
192
193	skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN);
194
195	dptr = skb_put(skb, ROSE_MIN_LEN + 3);
196
197	*dptr++ = AX25_P_ROSE;
198	*dptr++ = ROSE_GFI;
199	*dptr++ = 0x00;
200	*dptr++ = ROSE_RESTART_REQUEST;
201	*dptr++ = ROSE_DTE_ORIGINATED;
202	*dptr++ = 0;
203
204	if (!rose_send_frame(skb, neigh))
205		kfree_skb(skb);
206}
207
208/*
209 * This routine is called when a Restart Confirmation is needed
210 */
211static void rose_transmit_restart_confirmation(struct rose_neigh *neigh)
212{
213	struct sk_buff *skb;
214	unsigned char *dptr;
215	int len;
216
217	len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 1;
218
219	if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
220		return;
221
222	skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN);
223
224	dptr = skb_put(skb, ROSE_MIN_LEN + 1);
225
226	*dptr++ = AX25_P_ROSE;
227	*dptr++ = ROSE_GFI;
228	*dptr++ = 0x00;
229	*dptr++ = ROSE_RESTART_CONFIRMATION;
230
231	if (!rose_send_frame(skb, neigh))
232		kfree_skb(skb);
233}
234
235/*
236 * This routine is called when a Clear Request is needed outside of the context
237 * of a connected socket.
238 */
239void rose_transmit_clear_request(struct rose_neigh *neigh, unsigned int lci, unsigned char cause, unsigned char diagnostic)
240{
241	struct sk_buff *skb;
242	unsigned char *dptr;
243	int len;
244
245	len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 3;
246
247	if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
248		return;
249
250	skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN);
251
252	dptr = skb_put(skb, ROSE_MIN_LEN + 3);
253
254	*dptr++ = AX25_P_ROSE;
255	*dptr++ = ((lci >> 8) & 0x0F) | ROSE_GFI;
256	*dptr++ = ((lci >> 0) & 0xFF);
257	*dptr++ = ROSE_CLEAR_REQUEST;
258	*dptr++ = cause;
259	*dptr++ = diagnostic;
260
261	if (!rose_send_frame(skb, neigh))
262		kfree_skb(skb);
263}
264
265void rose_transmit_link(struct sk_buff *skb, struct rose_neigh *neigh)
266{
267	unsigned char *dptr;
268
269
270	if (neigh->loopback) {
271		rose_loopback_queue(skb, neigh);
272		return;
273	}
274
275	if (!rose_link_up(neigh))
276		neigh->restarted = 0;
277
278	dptr = skb_push(skb, 1);
279	*dptr++ = AX25_P_ROSE;
280
281	if (neigh->restarted) {
282		if (!rose_send_frame(skb, neigh))
283			kfree_skb(skb);
284	} else {
285		skb_queue_tail(&neigh->queue, skb);
286
287		if (!rose_t0timer_running(neigh)) {
288			rose_transmit_restart_request(neigh);
289			neigh->dce_mode = 0;
290			rose_start_t0timer(neigh);
291		}
292	}
293}
294