net: 8021q: Fix one possible panic caused by BUG_ON in free_netdev
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / rose / rose_link.c
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1da177e4
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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>
5a0e3ad6 19#include <linux/slab.h>
1da177e4
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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>
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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;
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43 neigh->ftimer.expires =
44 jiffies + msecs_to_jiffies(sysctl_rose_link_fail_timeout);
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45
46 add_timer(&neigh->ftimer);
47}
48
49static void rose_start_t0timer(struct rose_neigh *neigh)
50{
51 del_timer(&neigh->t0timer);
52
53 neigh->t0timer.data = (unsigned long)neigh;
54 neigh->t0timer.function = &rose_t0timer_expiry;
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55 neigh->t0timer.expires =
56 jiffies + msecs_to_jiffies(sysctl_rose_restart_request_timeout);
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57
58 add_timer(&neigh->t0timer);
59}
60
61void rose_stop_ftimer(struct rose_neigh *neigh)
62{
63 del_timer(&neigh->ftimer);
64}
65
66void rose_stop_t0timer(struct rose_neigh *neigh)
67{
68 del_timer(&neigh->t0timer);
69}
70
71int rose_ftimer_running(struct rose_neigh *neigh)
72{
73 return timer_pending(&neigh->ftimer);
74}
75
76static int rose_t0timer_running(struct rose_neigh *neigh)
77{
78 return timer_pending(&neigh->t0timer);
79}
80
81static void rose_ftimer_expiry(unsigned long param)
82{
83}
84
85static void rose_t0timer_expiry(unsigned long param)
86{
87 struct rose_neigh *neigh = (struct rose_neigh *)param;
88
89 rose_transmit_restart_request(neigh);
90
91 neigh->dce_mode = 0;
92
93 rose_start_t0timer(neigh);
94}
95
96/*
97 * Interface to ax25_send_frame. Changes my level 2 callsign depending
98 * on whether we have a global ROSE callsign or use the default port
99 * callsign.
100 */
101static int rose_send_frame(struct sk_buff *skb, struct rose_neigh *neigh)
102{
103 ax25_address *rose_call;
d00c362f 104 ax25_cb *ax25s;
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105
106 if (ax25cmp(&rose_callsign, &null_ax25_address) == 0)
107 rose_call = (ax25_address *)neigh->dev->dev_addr;
108 else
109 rose_call = &rose_callsign;
110
d00c362f 111 ax25s = neigh->ax25;
1da177e4 112 neigh->ax25 = ax25_send_frame(skb, 260, rose_call, &neigh->callsign, neigh->digipeat, neigh->dev);
d00c362f
JP
113 if (ax25s)
114 ax25_cb_put(ax25s);
1da177e4 115
a02cec21 116 return neigh->ax25 != NULL;
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117}
118
119/*
120 * Interface to ax25_link_up. Changes my level 2 callsign depending
121 * on whether we have a global ROSE callsign or use the default port
122 * callsign.
123 */
124static int rose_link_up(struct rose_neigh *neigh)
125{
126 ax25_address *rose_call;
d00c362f 127 ax25_cb *ax25s;
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128
129 if (ax25cmp(&rose_callsign, &null_ax25_address) == 0)
130 rose_call = (ax25_address *)neigh->dev->dev_addr;
131 else
132 rose_call = &rose_callsign;
133
d00c362f 134 ax25s = neigh->ax25;
1da177e4 135 neigh->ax25 = ax25_find_cb(rose_call, &neigh->callsign, neigh->digipeat, neigh->dev);
d00c362f
JP
136 if (ax25s)
137 ax25_cb_put(ax25s);
1da177e4 138
a02cec21 139 return neigh->ax25 != NULL;
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140}
141
142/*
143 * This handles all restart and diagnostic frames.
144 */
145void rose_link_rx_restart(struct sk_buff *skb, struct rose_neigh *neigh, unsigned short frametype)
146{
147 struct sk_buff *skbn;
148
149 switch (frametype) {
150 case ROSE_RESTART_REQUEST:
151 rose_stop_t0timer(neigh);
152 neigh->restarted = 1;
153 neigh->dce_mode = (skb->data[3] == ROSE_DTE_ORIGINATED);
154 rose_transmit_restart_confirmation(neigh);
155 break;
156
157 case ROSE_RESTART_CONFIRMATION:
158 rose_stop_t0timer(neigh);
159 neigh->restarted = 1;
160 break;
161
162 case ROSE_DIAGNOSTIC:
163 printk(KERN_WARNING "ROSE: received diagnostic #%d - %02X %02X %02X\n", skb->data[3], skb->data[4], skb->data[5], skb->data[6]);
164 break;
165
166 default:
167 printk(KERN_WARNING "ROSE: received unknown %02X with LCI 000\n", frametype);
168 break;
169 }
170
171 if (neigh->restarted) {
172 while ((skbn = skb_dequeue(&neigh->queue)) != NULL)
173 if (!rose_send_frame(skbn, neigh))
174 kfree_skb(skbn);
175 }
176}
177
178/*
179 * This routine is called when a Restart Request is needed
180 */
181static void rose_transmit_restart_request(struct rose_neigh *neigh)
182{
183 struct sk_buff *skb;
184 unsigned char *dptr;
185 int len;
186
187 len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 3;
188
189 if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
190 return;
191
192 skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN);
193
194 dptr = skb_put(skb, ROSE_MIN_LEN + 3);
195
196 *dptr++ = AX25_P_ROSE;
197 *dptr++ = ROSE_GFI;
198 *dptr++ = 0x00;
199 *dptr++ = ROSE_RESTART_REQUEST;
200 *dptr++ = ROSE_DTE_ORIGINATED;
201 *dptr++ = 0;
202
203 if (!rose_send_frame(skb, neigh))
204 kfree_skb(skb);
205}
206
207/*
208 * This routine is called when a Restart Confirmation is needed
209 */
210static void rose_transmit_restart_confirmation(struct rose_neigh *neigh)
211{
212 struct sk_buff *skb;
213 unsigned char *dptr;
214 int len;
215
216 len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 1;
217
218 if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
219 return;
220
221 skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN);
222
223 dptr = skb_put(skb, ROSE_MIN_LEN + 1);
224
225 *dptr++ = AX25_P_ROSE;
226 *dptr++ = ROSE_GFI;
227 *dptr++ = 0x00;
228 *dptr++ = ROSE_RESTART_CONFIRMATION;
229
230 if (!rose_send_frame(skb, neigh))
231 kfree_skb(skb);
232}
233
234/*
235 * This routine is called when a Clear Request is needed outside of the context
236 * of a connected socket.
237 */
238void rose_transmit_clear_request(struct rose_neigh *neigh, unsigned int lci, unsigned char cause, unsigned char diagnostic)
239{
240 struct sk_buff *skb;
241 unsigned char *dptr;
242 int len;
243
244 len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 3;
245
246 if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
247 return;
248
249 skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN);
250
251 dptr = skb_put(skb, ROSE_MIN_LEN + 3);
252
253 *dptr++ = AX25_P_ROSE;
254 *dptr++ = ((lci >> 8) & 0x0F) | ROSE_GFI;
255 *dptr++ = ((lci >> 0) & 0xFF);
256 *dptr++ = ROSE_CLEAR_REQUEST;
257 *dptr++ = cause;
258 *dptr++ = diagnostic;
259
260 if (!rose_send_frame(skb, neigh))
261 kfree_skb(skb);
262}
263
264void rose_transmit_link(struct sk_buff *skb, struct rose_neigh *neigh)
265{
266 unsigned char *dptr;
267
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268 if (neigh->loopback) {
269 rose_loopback_queue(skb, neigh);
270 return;
271 }
272
273 if (!rose_link_up(neigh))
274 neigh->restarted = 0;
275
276 dptr = skb_push(skb, 1);
277 *dptr++ = AX25_P_ROSE;
278
279 if (neigh->restarted) {
280 if (!rose_send_frame(skb, neigh))
281 kfree_skb(skb);
282 } else {
283 skb_queue_tail(&neigh->queue, skb);
284
285 if (!rose_t0timer_running(neigh)) {
286 rose_transmit_restart_request(neigh);
287 neigh->dce_mode = 0;
288 rose_start_t0timer(neigh);
289 }
290 }
291}