net/rose/rose_link.c

   1 /*
   2  *      ROSE release 003
   3  *
   4  *      This code REQUIRES 2.1.15 or higher/ NET3.038
   5  *
   6  *      This module:
   7  *              This module is free software; you can redistribute it and/or
   8  *              modify it under the terms of the GNU General Public License
   9  *              as published by the Free Software Foundation; either version
  10  *              2 of the License, or (at your option) any later version.
  11  *
  12  *      History
  13  *      ROSE 001        Jonathan(G4KLX) Cloned from rose_timer.c
  14  *      ROSE 003        Jonathan(G4KLX) New timer architecture.
  15  */
  16
  17 #include <linux/config.h>
  18 #if defined(CONFIG_ROSE) || defined(CONFIG_ROSE_MODULE)
  19 #include <linux/errno.h>
  20 #include <linux/types.h>
  21 #include <linux/socket.h>
  22 #include <linux/in.h>
  23 #include <linux/kernel.h>
  24 #include <linux/sched.h>
  25 #include <linux/timer.h>
  26 #include <linux/string.h>
  27 #include <linux/sockios.h>
  28 #include <linux/net.h>
  29 #include <net/ax25.h>
  30 #include <linux/inet.h>
  31 #include <linux/netdevice.h>
  32 #include <linux/skbuff.h>
  33 #include <net/sock.h>
  34 #include <asm/segment.h>
  35 #include <asm/system.h>
  36 #include <linux/fcntl.h>
  37 #include <linux/mm.h>
  38 #include <linux/interrupt.h>
  39 #include <linux/netfilter.h>
  40 #include <net/rose.h>
  41
  42 static void rose_ftimer_expiry(unsigned long);
  43 static void rose_t0timer_expiry(unsigned long);
  44
  45 void rose_start_ftimer(struct rose_neigh *neigh)
  46 {
  47         del_timer(&neigh->ftimer);
  48
  49         neigh->ftimer.data     = (unsigned long)neigh;
  50         neigh->ftimer.function = &rose_ftimer_expiry;
  51         neigh->ftimer.expires  = jiffies + sysctl_rose_link_fail_timeout;
  52
  53         add_timer(&neigh->ftimer);
  54 }
  55
  56 void rose_start_t0timer(struct rose_neigh *neigh)
  57 {
  58         del_timer(&neigh->t0timer);
  59
  60         neigh->t0timer.data     = (unsigned long)neigh;
  61         neigh->t0timer.function = &rose_t0timer_expiry;
  62         neigh->t0timer.expires  = jiffies + sysctl_rose_restart_request_timeout;
  63
  64         add_timer(&neigh->t0timer);
  65 }
  66
  67 void rose_stop_ftimer(struct rose_neigh *neigh)
  68 {
  69         del_timer(&neigh->ftimer);
  70 }
  71
  72 void rose_stop_t0timer(struct rose_neigh *neigh)
  73 {
  74         del_timer(&neigh->t0timer);
  75 }
  76
  77 int rose_ftimer_running(struct rose_neigh *neigh)
  78 {
  79         return (neigh->ftimer.prev != NULL || neigh->ftimer.next != NULL);
  80 }
  81
  82 int rose_t0timer_running(struct rose_neigh *neigh)
  83 {
  84         return (neigh->t0timer.prev != NULL || neigh->t0timer.next != NULL);
  85 }
  86
  87 static void rose_ftimer_expiry(unsigned long param)
  88 {
  89 }
  90
  91 static void rose_t0timer_expiry(unsigned long param)
  92 {
  93         struct rose_neigh *neigh = (struct rose_neigh *)param;
  94
  95         rose_transmit_restart_request(neigh);
  96
  97         neigh->dce_mode = 0;
  98
  99         rose_start_t0timer(neigh);
 100 }
 101
 102 /*
 103  *      Interface to ax25_send_frame. Changes my level 2 callsign depending
 104  *      on whether we have a global ROSE callsign or use the default port
 105  *      callsign.
 106  */
 107 static int rose_send_frame(struct sk_buff *skb, struct rose_neigh *neigh)
 108 {
 109         ax25_address *rose_call;
 110
 111         if (ax25cmp(&rose_callsign, &null_ax25_address) == 0)
 112                 rose_call = (ax25_address *)neigh->dev->dev_addr;
 113         else
 114                 rose_call = &rose_callsign;
 115
 116         neigh->ax25 = ax25_send_frame(skb, 260, rose_call, &neigh->callsign, neigh->digipeat, neigh->dev);
 117
 118         return (neigh->ax25 != NULL);
 119 }
 120
 121 /*
 122  *      Interface to ax25_link_up. Changes my level 2 callsign depending
 123  *      on whether we have a global ROSE callsign or use the default port
 124  *      callsign.
 125  */
 126 static int rose_link_up(struct rose_neigh *neigh)
 127 {
 128         ax25_address *rose_call;
 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         neigh->ax25 = ax25_find_cb(rose_call, &neigh->callsign, neigh->digipeat, neigh->dev);
 136
 137         return (neigh->ax25 != NULL);
 138 }
 139
 140 /*
 141  *      This handles all restart and diagnostic frames.
 142  */
 143 void rose_link_rx_restart(struct sk_buff *skb, struct rose_neigh *neigh, unsigned short frametype)
 144 {
 145         struct sk_buff *skbn;
 146
 147         switch (frametype) {
 148                 case ROSE_RESTART_REQUEST:
 149                         rose_stop_t0timer(neigh);
 150                         neigh->restarted = 1;
 151                         neigh->dce_mode  = (skb->data[3] == ROSE_DTE_ORIGINATED);
 152                         rose_transmit_restart_confirmation(neigh);
 153                         break;
 154
 155                 case ROSE_RESTART_CONFIRMATION:
 156                         rose_stop_t0timer(neigh);
 157                         neigh->restarted = 1;
 158                         break;
 159
 160                 case ROSE_DIAGNOSTIC:
 161                         printk(KERN_WARNING "ROSE: received diagnostic #%d - %02X %02X %02X\n", skb->data[3], skb->data[4], skb->data[5], skb->data[6]);
 162                         break;
 163
 164                 default:
 165                         printk(KERN_WARNING "ROSE: received unknown %02X with LCI 000\n", frametype);
 166                         break;
 167         }
 168
 169         if (neigh->restarted) {
 170                 while ((skbn = skb_dequeue(&neigh->queue)) != NULL)
 171                         if (!rose_send_frame(skbn, neigh))
 172                                 kfree_skb(skbn);
 173         }
 174 }
 175
 176 /*
 177  *      This routine is called when a Restart Request is needed
 178  */
 179 void rose_transmit_restart_request(struct rose_neigh *neigh)
 180 {
 181         struct sk_buff *skb;
 182         unsigned char *dptr;
 183         int len;
 184
 185         len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 3;
 186
 187         if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
 188                 return;
 189
 190         skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN);
 191
 192         dptr = skb_put(skb, ROSE_MIN_LEN + 3);
 193
 194         *dptr++ = AX25_P_ROSE;
 195         *dptr++ = ROSE_GFI;
 196         *dptr++ = 0x00;
 197         *dptr++ = ROSE_RESTART_REQUEST;
 198         *dptr++ = ROSE_DTE_ORIGINATED;
 199         *dptr++ = 0;
 200
 201         if (!rose_send_frame(skb, neigh))
 202                 kfree_skb(skb);
 203 }
 204
 205 /*
 206  * This routine is called when a Restart Confirmation is needed
 207  */
 208 void rose_transmit_restart_confirmation(struct rose_neigh *neigh)
 209 {
 210         struct sk_buff *skb;
 211         unsigned char *dptr;
 212         int len;
 213
 214         len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 1;
 215
 216         if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
 217                 return;
 218
 219         skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN);
 220
 221         dptr = skb_put(skb, ROSE_MIN_LEN + 1);
 222
 223         *dptr++ = AX25_P_ROSE;
 224         *dptr++ = ROSE_GFI;
 225         *dptr++ = 0x00;
 226         *dptr++ = ROSE_RESTART_CONFIRMATION;
 227
 228         if (!rose_send_frame(skb, neigh))
 229                 kfree_skb(skb);
 230 }
 231
 232 /*
 233  * This routine is called when a Diagnostic is required.
 234  */
 235 void rose_transmit_diagnostic(struct rose_neigh *neigh, unsigned char diag)
 236 {
 237         struct sk_buff *skb;
 238         unsigned char *dptr;
 239         int len;
 240
 241         len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 2;
 242
 243         if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
 244                 return;
 245
 246         skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN);
 247
 248         dptr = skb_put(skb, ROSE_MIN_LEN + 2);
 249
 250         *dptr++ = AX25_P_ROSE;
 251         *dptr++ = ROSE_GFI;
 252         *dptr++ = 0x00;
 253         *dptr++ = ROSE_DIAGNOSTIC;
 254         *dptr++ = diag;
 255
 256         if (!rose_send_frame(skb, neigh))
 257                 kfree_skb(skb);
 258 }
 259
 260 /*
 261  * This routine is called when a Clear Request is needed outside of the context
 262  * of a connected socket.
 263  */
 264 void rose_transmit_clear_request(struct rose_neigh *neigh, unsigned int lci, unsigned char cause, unsigned char diagnostic)
 265 {
 266         struct sk_buff *skb;
 267         unsigned char *dptr;
 268         int len;
 269
 270         len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 3;
 271
 272         if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
 273                 return;
 274
 275         skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN);
 276
 277         dptr = skb_put(skb, ROSE_MIN_LEN + 3);
 278
 279         *dptr++ = AX25_P_ROSE;
 280         *dptr++ = ((lci >> 8) & 0x0F) | ROSE_GFI;
 281         *dptr++ = ((lci >> 0) & 0xFF);
 282         *dptr++ = ROSE_CLEAR_REQUEST;
 283         *dptr++ = cause;
 284         *dptr++ = diagnostic;
 285
 286         if (!rose_send_frame(skb, neigh))
 287                 kfree_skb(skb);
 288 }
 289
 290 void rose_transmit_link(struct sk_buff *skb, struct rose_neigh *neigh)
 291 {
 292         unsigned char *dptr;
 293
 294 #if 0
 295         if (call_fw_firewall(PF_ROSE, skb->dev, skb->data, NULL, &skb) != FW_ACCEPT) {
 296                 kfree_skb(skb);
 297                 return;
 298         }
 299 #endif
 300
 301         if (neigh->loopback) {
 302                 rose_loopback_queue(skb, neigh);
 303                 return;
 304         }
 305
 306         if (!rose_link_up(neigh))
 307                 neigh->restarted = 0;
 308
 309         dptr = skb_push(skb, 1);
 310         *dptr++ = AX25_P_ROSE;
 311
 312         if (neigh->restarted) {
 313                 if (!rose_send_frame(skb, neigh))
 314                         kfree_skb(skb);
 315         } else {
 316                 skb_queue_tail(&neigh->queue, skb);
 317
 318                 if (!rose_t0timer_running(neigh)) {
 319                         rose_transmit_restart_request(neigh);
 320                         neigh->dce_mode = 0;
 321                         rose_start_t0timer(neigh);
 322                 }
 323         }
 324 }
 325
 326 #endif