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/errno.h>
  18 #include <linux/types.h>
  19 #include <linux/socket.h>
  20 #include <linux/in.h>
  21 #include <linux/kernel.h>
  22 #include <linux/sched.h>
  23 #include <linux/timer.h>
  24 #include <linux/string.h>
  25 #include <linux/sockios.h>
  26 #include <linux/net.h>
  27 #include <net/ax25.h>
  28 #include <linux/inet.h>
  29 #include <linux/netdevice.h>
  30 #include <linux/skbuff.h>
  31 #include <net/sock.h>
  32 #include <asm/segment.h>
  33 #include <asm/system.h>
  34 #include <linux/fcntl.h>
  35 #include <linux/mm.h>
  36 #include <linux/interrupt.h>
  37 #include <linux/netfilter.h>
  38 #include <net/rose.h>
  39
  40 static void rose_ftimer_expiry(unsigned long);
  41 static void rose_t0timer_expiry(unsigned long);
  42
  43 void rose_start_ftimer(struct rose_neigh *neigh)
  44 {
  45         del_timer(&neigh->ftimer);
  46
  47         neigh->ftimer.data     = (unsigned long)neigh;
  48         neigh->ftimer.function = &rose_ftimer_expiry;
  49         neigh->ftimer.expires  = jiffies + sysctl_rose_link_fail_timeout;
  50
  51         add_timer(&neigh->ftimer);
  52 }
  53
  54 void rose_start_t0timer(struct rose_neigh *neigh)
  55 {
  56         del_timer(&neigh->t0timer);
  57
  58         neigh->t0timer.data     = (unsigned long)neigh;
  59         neigh->t0timer.function = &rose_t0timer_expiry;
  60         neigh->t0timer.expires  = jiffies + sysctl_rose_restart_request_timeout;
  61
  62         add_timer(&neigh->t0timer);
  63 }
  64
  65 void rose_stop_ftimer(struct rose_neigh *neigh)
  66 {
  67         del_timer(&neigh->ftimer);
  68 }
  69
  70 void rose_stop_t0timer(struct rose_neigh *neigh)
  71 {
  72         del_timer(&neigh->t0timer);
  73 }
  74
  75 int rose_ftimer_running(struct rose_neigh *neigh)
  76 {
  77         return timer_pending(&neigh->ftimer);
  78 }
  79
  80 int rose_t0timer_running(struct rose_neigh *neigh)
  81 {
  82         return timer_pending(&neigh->t0timer);
  83 }
  84
  85 static void rose_ftimer_expiry(unsigned long param)
  86 {
  87 }
  88
  89 static void rose_t0timer_expiry(unsigned long param)
  90 {
  91         struct rose_neigh *neigh = (struct rose_neigh *)param;
  92
  93         rose_transmit_restart_request(neigh);
  94
  95         neigh->dce_mode = 0;
  96
  97         rose_start_t0timer(neigh);
  98 }
  99
 100 /*
 101  *      Interface to ax25_send_frame. Changes my level 2 callsign depending
 102  *      on whether we have a global ROSE callsign or use the default port
 103  *      callsign.
 104  */
 105 static int rose_send_frame(struct sk_buff *skb, struct rose_neigh *neigh)
 106 {
 107         ax25_address *rose_call;
 108
 109         if (ax25cmp(&rose_callsign, &null_ax25_address) == 0)
 110                 rose_call = (ax25_address *)neigh->dev->dev_addr;
 111         else
 112                 rose_call = &rose_callsign;
 113
 114         neigh->ax25 = ax25_send_frame(skb, 260, rose_call, &neigh->callsign, neigh->digipeat, neigh->dev);
 115
 116         return (neigh->ax25 != NULL);
 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  */
 124 static int rose_link_up(struct rose_neigh *neigh)
 125 {
 126         ax25_address *rose_call;
 127
 128         if (ax25cmp(&rose_callsign, &null_ax25_address) == 0)
 129                 rose_call = (ax25_address *)neigh->dev->dev_addr;
 130         else
 131                 rose_call = &rose_callsign;
 132
 133         neigh->ax25 = ax25_find_cb(rose_call, &neigh->callsign, neigh->digipeat, neigh->dev);
 134
 135         return (neigh->ax25 != NULL);
 136 }
 137
 138 /*
 139  *      This handles all restart and diagnostic frames.
 140  */
 141 void rose_link_rx_restart(struct sk_buff *skb, struct rose_neigh *neigh, unsigned short frametype)
 142 {
 143         struct sk_buff *skbn;
 144
 145         switch (frametype) {
 146                 case ROSE_RESTART_REQUEST:
 147                         rose_stop_t0timer(neigh);
 148                         neigh->restarted = 1;
 149                         neigh->dce_mode  = (skb->data[3] == ROSE_DTE_ORIGINATED);
 150                         rose_transmit_restart_confirmation(neigh);
 151                         break;
 152
 153                 case ROSE_RESTART_CONFIRMATION:
 154                         rose_stop_t0timer(neigh);
 155                         neigh->restarted = 1;
 156                         break;
 157
 158                 case ROSE_DIAGNOSTIC:
 159                         printk(KERN_WARNING "ROSE: received diagnostic #%d - %02X %02X %02X\n", skb->data[3], skb->data[4], skb->data[5], skb->data[6]);
 160                         break;
 161
 162                 default:
 163                         printk(KERN_WARNING "ROSE: received unknown %02X with LCI 000\n", frametype);
 164                         break;
 165         }
 166
 167         if (neigh->restarted) {
 168                 while ((skbn = skb_dequeue(&neigh->queue)) != NULL)
 169                         if (!rose_send_frame(skbn, neigh))
 170                                 kfree_skb(skbn);
 171         }
 172 }
 173
 174 /*
 175  *      This routine is called when a Restart Request is needed
 176  */
 177 void rose_transmit_restart_request(struct rose_neigh *neigh)
 178 {
 179         struct sk_buff *skb;
 180         unsigned char *dptr;
 181         int len;
 182
 183         len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 3;
 184
 185         if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
 186                 return;
 187
 188         skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN);
 189
 190         dptr = skb_put(skb, ROSE_MIN_LEN + 3);
 191
 192         *dptr++ = AX25_P_ROSE;
 193         *dptr++ = ROSE_GFI;
 194         *dptr++ = 0x00;
 195         *dptr++ = ROSE_RESTART_REQUEST;
 196         *dptr++ = ROSE_DTE_ORIGINATED;
 197         *dptr++ = 0;
 198
 199         if (!rose_send_frame(skb, neigh))
 200                 kfree_skb(skb);
 201 }
 202
 203 /*
 204  * This routine is called when a Restart Confirmation is needed
 205  */
 206 void rose_transmit_restart_confirmation(struct rose_neigh *neigh)
 207 {
 208         struct sk_buff *skb;
 209         unsigned char *dptr;
 210         int len;
 211
 212         len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 1;
 213
 214         if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
 215                 return;
 216
 217         skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN);
 218
 219         dptr = skb_put(skb, ROSE_MIN_LEN + 1);
 220
 221         *dptr++ = AX25_P_ROSE;
 222         *dptr++ = ROSE_GFI;
 223         *dptr++ = 0x00;
 224         *dptr++ = ROSE_RESTART_CONFIRMATION;
 225
 226         if (!rose_send_frame(skb, neigh))
 227                 kfree_skb(skb);
 228 }
 229
 230 /*
 231  * This routine is called when a Diagnostic is required.
 232  */
 233 void rose_transmit_diagnostic(struct rose_neigh *neigh, unsigned char diag)
 234 {
 235         struct sk_buff *skb;
 236         unsigned char *dptr;
 237         int len;
 238
 239         len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 2;
 240
 241         if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
 242                 return;
 243
 244         skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN);
 245
 246         dptr = skb_put(skb, ROSE_MIN_LEN + 2);
 247
 248         *dptr++ = AX25_P_ROSE;
 249         *dptr++ = ROSE_GFI;
 250         *dptr++ = 0x00;
 251         *dptr++ = ROSE_DIAGNOSTIC;
 252         *dptr++ = diag;
 253
 254         if (!rose_send_frame(skb, neigh))
 255                 kfree_skb(skb);
 256 }
 257
 258 /*
 259  * This routine is called when a Clear Request is needed outside of the context
 260  * of a connected socket.
 261  */
 262 void rose_transmit_clear_request(struct rose_neigh *neigh, unsigned int lci, unsigned char cause, unsigned char diagnostic)
 263 {
 264         struct sk_buff *skb;
 265         unsigned char *dptr;
 266         int len;
 267         struct net_device *first;
 268         int faclen = 0;
 269
 270         len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 3;
 271
 272         first = rose_dev_first();
 273         if (first)
 274                 faclen = 6 + AX25_ADDR_LEN + 3 + ROSE_ADDR_LEN;
 275
 276         if ((skb = alloc_skb(len + faclen, GFP_ATOMIC)) == NULL)
 277                 return;
 278
 279         skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN);
 280
 281         dptr = skb_put(skb, ROSE_MIN_LEN + 3 + faclen);
 282
 283         *dptr++ = AX25_P_ROSE;
 284         *dptr++ = ((lci >> 8) & 0x0F) | ROSE_GFI;
 285         *dptr++ = ((lci >> 0) & 0xFF);
 286         *dptr++ = ROSE_CLEAR_REQUEST;
 287         *dptr++ = cause;
 288         *dptr++ = diagnostic;
 289
 290         if (first) {
 291                 *dptr++ = 0x00;         /* Address length */
 292                 *dptr++ = 4 + AX25_ADDR_LEN + 3 + ROSE_ADDR_LEN; /* Facilities length */
 293                 *dptr++ = 0;
 294                 *dptr++ = FAC_NATIONAL;
 295                 *dptr++ = FAC_NATIONAL_FAIL_CALL;
 296                 *dptr++ = AX25_ADDR_LEN;
 297                 memcpy(dptr, &rose_callsign, AX25_ADDR_LEN);
 298                 dptr += AX25_ADDR_LEN;
 299                 *dptr++ = FAC_NATIONAL_FAIL_ADD;
 300                 *dptr++ = ROSE_ADDR_LEN + 1;
 301                 *dptr++ = ROSE_ADDR_LEN * 2;
 302                 memcpy(dptr, first->dev_addr, ROSE_ADDR_LEN);
 303         }
 304
 305         if (!rose_send_frame(skb, neigh))
 306                 kfree_skb(skb);
 307 }
 308
 309 void rose_transmit_link(struct sk_buff *skb, struct rose_neigh *neigh)
 310 {
 311         unsigned char *dptr;
 312
 313 #if 0
 314         if (call_fw_firewall(PF_ROSE, skb->dev, skb->data, NULL, &skb) != FW_ACCEPT) {
 315                 kfree_skb(skb);
 316                 return;
 317         }
 318 #endif
 319
 320         if (neigh->loopback) {
 321                 rose_loopback_queue(skb, neigh);
 322                 return;
 323         }
 324
 325         if (!rose_link_up(neigh))
 326                 neigh->restarted = 0;
 327
 328         dptr = skb_push(skb, 1);
 329         *dptr++ = AX25_P_ROSE;
 330
 331         if (neigh->restarted) {
 332                 if (!rose_send_frame(skb, neigh))
 333                         kfree_skb(skb);
 334         } else {
 335                 skb_queue_tail(&neigh->queue, skb);
 336
 337                 if (!rose_t0timer_running(neigh)) {
 338                         rose_transmit_restart_request(neigh);
 339                         neigh->dce_mode = 0;
 340                         rose_start_t0timer(neigh);
 341                 }
 342         }
 343 }