[PATCH] as-iosched: use new io context counting mechanism
[linux-2.6.git] / net / rose / rose_link.c
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 <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
31 static void rose_ftimer_expiry(unsigned long);
32 static void rose_t0timer_expiry(unsigned long);
33
34 static void rose_transmit_restart_confirmation(struct rose_neigh *neigh);
35 static void rose_transmit_restart_request(struct rose_neigh *neigh);
36
37 void 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  =
44                 jiffies + msecs_to_jiffies(sysctl_rose_link_fail_timeout);
45
46         add_timer(&neigh->ftimer);
47 }
48
49 static 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;
55         neigh->t0timer.expires  =
56                 jiffies + msecs_to_jiffies(sysctl_rose_restart_request_timeout);
57
58         add_timer(&neigh->t0timer);
59 }
60
61 void rose_stop_ftimer(struct rose_neigh *neigh)
62 {
63         del_timer(&neigh->ftimer);
64 }
65
66 void rose_stop_t0timer(struct rose_neigh *neigh)
67 {
68         del_timer(&neigh->t0timer);
69 }
70
71 int rose_ftimer_running(struct rose_neigh *neigh)
72 {
73         return timer_pending(&neigh->ftimer);
74 }
75
76 static int rose_t0timer_running(struct rose_neigh *neigh)
77 {
78         return timer_pending(&neigh->t0timer);
79 }
80
81 static void rose_ftimer_expiry(unsigned long param)
82 {
83 }
84
85 static 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  */
101 static int rose_send_frame(struct sk_buff *skb, struct rose_neigh *neigh)
102 {
103         ax25_address *rose_call;
104
105         if (ax25cmp(&rose_callsign, &null_ax25_address) == 0)
106                 rose_call = (ax25_address *)neigh->dev->dev_addr;
107         else
108                 rose_call = &rose_callsign;
109
110         neigh->ax25 = ax25_send_frame(skb, 260, rose_call, &neigh->callsign, neigh->digipeat, neigh->dev);
111
112         return (neigh->ax25 != NULL);
113 }
114
115 /*
116  *      Interface to ax25_link_up. Changes my level 2 callsign depending
117  *      on whether we have a global ROSE callsign or use the default port
118  *      callsign.
119  */
120 static int rose_link_up(struct rose_neigh *neigh)
121 {
122         ax25_address *rose_call;
123
124         if (ax25cmp(&rose_callsign, &null_ax25_address) == 0)
125                 rose_call = (ax25_address *)neigh->dev->dev_addr;
126         else
127                 rose_call = &rose_callsign;
128
129         neigh->ax25 = ax25_find_cb(rose_call, &neigh->callsign, neigh->digipeat, neigh->dev);
130
131         return (neigh->ax25 != NULL);
132 }
133
134 /*
135  *      This handles all restart and diagnostic frames.
136  */
137 void rose_link_rx_restart(struct sk_buff *skb, struct rose_neigh *neigh, unsigned short frametype)
138 {
139         struct sk_buff *skbn;
140
141         switch (frametype) {
142         case ROSE_RESTART_REQUEST:
143                 rose_stop_t0timer(neigh);
144                 neigh->restarted = 1;
145                 neigh->dce_mode  = (skb->data[3] == ROSE_DTE_ORIGINATED);
146                 rose_transmit_restart_confirmation(neigh);
147                 break;
148
149         case ROSE_RESTART_CONFIRMATION:
150                 rose_stop_t0timer(neigh);
151                 neigh->restarted = 1;
152                 break;
153
154         case ROSE_DIAGNOSTIC:
155                 printk(KERN_WARNING "ROSE: received diagnostic #%d - %02X %02X %02X\n", skb->data[3], skb->data[4], skb->data[5], skb->data[6]);
156                 break;
157
158         default:
159                 printk(KERN_WARNING "ROSE: received unknown %02X with LCI 000\n", frametype);
160                 break;
161         }
162
163         if (neigh->restarted) {
164                 while ((skbn = skb_dequeue(&neigh->queue)) != NULL)
165                         if (!rose_send_frame(skbn, neigh))
166                                 kfree_skb(skbn);
167         }
168 }
169
170 /*
171  *      This routine is called when a Restart Request is needed
172  */
173 static void rose_transmit_restart_request(struct rose_neigh *neigh)
174 {
175         struct sk_buff *skb;
176         unsigned char *dptr;
177         int len;
178
179         len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 3;
180
181         if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
182                 return;
183
184         skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN);
185
186         dptr = skb_put(skb, ROSE_MIN_LEN + 3);
187
188         *dptr++ = AX25_P_ROSE;
189         *dptr++ = ROSE_GFI;
190         *dptr++ = 0x00;
191         *dptr++ = ROSE_RESTART_REQUEST;
192         *dptr++ = ROSE_DTE_ORIGINATED;
193         *dptr++ = 0;
194
195         if (!rose_send_frame(skb, neigh))
196                 kfree_skb(skb);
197 }
198
199 /*
200  * This routine is called when a Restart Confirmation is needed
201  */
202 static void rose_transmit_restart_confirmation(struct rose_neigh *neigh)
203 {
204         struct sk_buff *skb;
205         unsigned char *dptr;
206         int len;
207
208         len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 1;
209
210         if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
211                 return;
212
213         skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN);
214
215         dptr = skb_put(skb, ROSE_MIN_LEN + 1);
216
217         *dptr++ = AX25_P_ROSE;
218         *dptr++ = ROSE_GFI;
219         *dptr++ = 0x00;
220         *dptr++ = ROSE_RESTART_CONFIRMATION;
221
222         if (!rose_send_frame(skb, neigh))
223                 kfree_skb(skb);
224 }
225
226 /*
227  * This routine is called when a Clear Request is needed outside of the context
228  * of a connected socket.
229  */
230 void rose_transmit_clear_request(struct rose_neigh *neigh, unsigned int lci, unsigned char cause, unsigned char diagnostic)
231 {
232         struct sk_buff *skb;
233         unsigned char *dptr;
234         int len;
235
236         len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 3;
237
238         if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
239                 return;
240
241         skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN);
242
243         dptr = skb_put(skb, ROSE_MIN_LEN + 3);
244
245         *dptr++ = AX25_P_ROSE;
246         *dptr++ = ((lci >> 8) & 0x0F) | ROSE_GFI;
247         *dptr++ = ((lci >> 0) & 0xFF);
248         *dptr++ = ROSE_CLEAR_REQUEST;
249         *dptr++ = cause;
250         *dptr++ = diagnostic;
251
252         if (!rose_send_frame(skb, neigh))
253                 kfree_skb(skb);
254 }
255
256 void rose_transmit_link(struct sk_buff *skb, struct rose_neigh *neigh)
257 {
258         unsigned char *dptr;
259
260 #if 0
261         if (call_fw_firewall(PF_ROSE, skb->dev, skb->data, NULL, &skb) != FW_ACCEPT) {
262                 kfree_skb(skb);
263                 return;
264         }
265 #endif
266
267         if (neigh->loopback) {
268                 rose_loopback_queue(skb, neigh);
269                 return;
270         }
271
272         if (!rose_link_up(neigh))
273                 neigh->restarted = 0;
274
275         dptr = skb_push(skb, 1);
276         *dptr++ = AX25_P_ROSE;
277
278         if (neigh->restarted) {
279                 if (!rose_send_frame(skb, neigh))
280                         kfree_skb(skb);
281         } else {
282                 skb_queue_tail(&neigh->queue, skb);
283
284                 if (!rose_t0timer_running(neigh)) {
285                         rose_transmit_restart_request(neigh);
286                         neigh->dce_mode = 0;
287                         rose_start_t0timer(neigh);
288                 }
289         }
290 }