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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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 <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 <asm/system.h>
25#include <linux/fcntl.h>
26#include <linux/mm.h>
27#include <linux/interrupt.h>
28#include <linux/netfilter.h>
29#include <net/rose.h>
30
31static void rose_ftimer_expiry(unsigned long);
32static void rose_t0timer_expiry(unsigned long);
33
34static void rose_transmit_restart_confirmation(struct rose_neigh *neigh);
35static void rose_transmit_restart_request(struct rose_neigh *neigh);
36
37void rose_start_ftimer(struct rose_neigh *neigh)
38{
39 del_timer(&neigh->ftimer);
40
41 neigh->ftimer.data = (unsigned long)neigh;
42 neigh->ftimer.function = &rose_ftimer_expiry;
43 neigh->ftimer.expires = jiffies + sysctl_rose_link_fail_timeout;
44
45 add_timer(&neigh->ftimer);
46}
47
48static void rose_start_t0timer(struct rose_neigh *neigh)
49{
50 del_timer(&neigh->t0timer);
51
52 neigh->t0timer.data = (unsigned long)neigh;
53 neigh->t0timer.function = &rose_t0timer_expiry;
54 neigh->t0timer.expires = jiffies + sysctl_rose_restart_request_timeout;
55
56 add_timer(&neigh->t0timer);
57}
58
59void rose_stop_ftimer(struct rose_neigh *neigh)
60{
61 del_timer(&neigh->ftimer);
62}
63
64void rose_stop_t0timer(struct rose_neigh *neigh)
65{
66 del_timer(&neigh->t0timer);
67}
68
69int rose_ftimer_running(struct rose_neigh *neigh)
70{
71 return timer_pending(&neigh->ftimer);
72}
73
74static int rose_t0timer_running(struct rose_neigh *neigh)
75{
76 return timer_pending(&neigh->t0timer);
77}
78
79static void rose_ftimer_expiry(unsigned long param)
80{
81}
82
83static void rose_t0timer_expiry(unsigned long param)
84{
85 struct rose_neigh *neigh = (struct rose_neigh *)param;
86
87 rose_transmit_restart_request(neigh);
88
89 neigh->dce_mode = 0;
90
91 rose_start_t0timer(neigh);
92}
93
94/*
95 * Interface to ax25_send_frame. Changes my level 2 callsign depending
96 * on whether we have a global ROSE callsign or use the default port
97 * callsign.
98 */
99static int rose_send_frame(struct sk_buff *skb, struct rose_neigh *neigh)
100{
101 ax25_address *rose_call;
102
103 if (ax25cmp(&rose_callsign, &null_ax25_address) == 0)
104 rose_call = (ax25_address *)neigh->dev->dev_addr;
105 else
106 rose_call = &rose_callsign;
107
108 neigh->ax25 = ax25_send_frame(skb, 260, rose_call, &neigh->callsign, neigh->digipeat, neigh->dev);
109
110 return (neigh->ax25 != NULL);
111}
112
113/*
114 * Interface to ax25_link_up. Changes my level 2 callsign depending
115 * on whether we have a global ROSE callsign or use the default port
116 * callsign.
117 */
118static int rose_link_up(struct rose_neigh *neigh)
119{
120 ax25_address *rose_call;
121
122 if (ax25cmp(&rose_callsign, &null_ax25_address) == 0)
123 rose_call = (ax25_address *)neigh->dev->dev_addr;
124 else
125 rose_call = &rose_callsign;
126
127 neigh->ax25 = ax25_find_cb(rose_call, &neigh->callsign, neigh->digipeat, neigh->dev);
128
129 return (neigh->ax25 != NULL);
130}
131
132/*
133 * This handles all restart and diagnostic frames.
134 */
135void rose_link_rx_restart(struct sk_buff *skb, struct rose_neigh *neigh, unsigned short frametype)
136{
137 struct sk_buff *skbn;
138
139 switch (frametype) {
140 case ROSE_RESTART_REQUEST:
141 rose_stop_t0timer(neigh);
142 neigh->restarted = 1;
143 neigh->dce_mode = (skb->data[3] == ROSE_DTE_ORIGINATED);
144 rose_transmit_restart_confirmation(neigh);
145 break;
146
147 case ROSE_RESTART_CONFIRMATION:
148 rose_stop_t0timer(neigh);
149 neigh->restarted = 1;
150 break;
151
152 case ROSE_DIAGNOSTIC:
153 printk(KERN_WARNING "ROSE: received diagnostic #%d - %02X %02X %02X\n", skb->data[3], skb->data[4], skb->data[5], skb->data[6]);
154 break;
155
156 default:
157 printk(KERN_WARNING "ROSE: received unknown %02X with LCI 000\n", frametype);
158 break;
159 }
160
161 if (neigh->restarted) {
162 while ((skbn = skb_dequeue(&neigh->queue)) != NULL)
163 if (!rose_send_frame(skbn, neigh))
164 kfree_skb(skbn);
165 }
166}
167
168/*
169 * This routine is called when a Restart Request is needed
170 */
171static void rose_transmit_restart_request(struct rose_neigh *neigh)
172{
173 struct sk_buff *skb;
174 unsigned char *dptr;
175 int len;
176
177 len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 3;
178
179 if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
180 return;
181
182 skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN);
183
184 dptr = skb_put(skb, ROSE_MIN_LEN + 3);
185
186 *dptr++ = AX25_P_ROSE;
187 *dptr++ = ROSE_GFI;
188 *dptr++ = 0x00;
189 *dptr++ = ROSE_RESTART_REQUEST;
190 *dptr++ = ROSE_DTE_ORIGINATED;
191 *dptr++ = 0;
192
193 if (!rose_send_frame(skb, neigh))
194 kfree_skb(skb);
195}
196
197/*
198 * This routine is called when a Restart Confirmation is needed
199 */
200static void rose_transmit_restart_confirmation(struct rose_neigh *neigh)
201{
202 struct sk_buff *skb;
203 unsigned char *dptr;
204 int len;
205
206 len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 1;
207
208 if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
209 return;
210
211 skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN);
212
213 dptr = skb_put(skb, ROSE_MIN_LEN + 1);
214
215 *dptr++ = AX25_P_ROSE;
216 *dptr++ = ROSE_GFI;
217 *dptr++ = 0x00;
218 *dptr++ = ROSE_RESTART_CONFIRMATION;
219
220 if (!rose_send_frame(skb, neigh))
221 kfree_skb(skb);
222}
223
224/*
225 * This routine is called when a Clear Request is needed outside of the context
226 * of a connected socket.
227 */
228void rose_transmit_clear_request(struct rose_neigh *neigh, unsigned int lci, unsigned char cause, unsigned char diagnostic)
229{
230 struct sk_buff *skb;
231 unsigned char *dptr;
232 int len;
233
234 len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 3;
235
236 if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
237 return;
238
239 skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN);
240
241 dptr = skb_put(skb, ROSE_MIN_LEN + 3);
242
243 *dptr++ = AX25_P_ROSE;
244 *dptr++ = ((lci >> 8) & 0x0F) | ROSE_GFI;
245 *dptr++ = ((lci >> 0) & 0xFF);
246 *dptr++ = ROSE_CLEAR_REQUEST;
247 *dptr++ = cause;
248 *dptr++ = diagnostic;
249
250 if (!rose_send_frame(skb, neigh))
251 kfree_skb(skb);
252}
253
254void rose_transmit_link(struct sk_buff *skb, struct rose_neigh *neigh)
255{
256 unsigned char *dptr;
257
258#if 0
259 if (call_fw_firewall(PF_ROSE, skb->dev, skb->data, NULL, &skb) != FW_ACCEPT) {
260 kfree_skb(skb);
261 return;
262 }
263#endif
264
265 if (neigh->loopback) {
266 rose_loopback_queue(skb, neigh);
267 return;
268 }
269
270 if (!rose_link_up(neigh))
271 neigh->restarted = 0;
272
273 dptr = skb_push(skb, 1);
274 *dptr++ = AX25_P_ROSE;
275
276 if (neigh->restarted) {
277 if (!rose_send_frame(skb, neigh))
278 kfree_skb(skb);
279 } else {
280 skb_queue_tail(&neigh->queue, skb);
281
282 if (!rose_t0timer_running(neigh)) {
283 rose_transmit_restart_request(neigh);
284 neigh->dce_mode = 0;
285 rose_start_t0timer(neigh);
286 }
287 }
288}