net/rose/rose_subr.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 nr_subr.c
  14  *      ROSE 002        Jonathan(G4KLX) Centralised disconnect processing.
  15  *      ROSE 003        Jonathan(G4KLX) Added use count to neighbours.
  16  */
  17
  18 #include <linux/errno.h>
  19 #include <linux/types.h>
  20 #include <linux/socket.h>
  21 #include <linux/in.h>
  22 #include <linux/kernel.h>
  23 #include <linux/sched.h>
  24 #include <linux/timer.h>
  25 #include <linux/string.h>
  26 #include <linux/sockios.h>
  27 #include <linux/net.h>
  28 #include <net/ax25.h>
  29 #include <linux/inet.h>
  30 #include <linux/netdevice.h>
  31 #include <linux/skbuff.h>
  32 #include <net/sock.h>
  33 #include <asm/segment.h>
  34 #include <asm/system.h>
  35 #include <linux/fcntl.h>
  36 #include <linux/mm.h>
  37 #include <linux/interrupt.h>
  38 #include <net/rose.h>
  39
  40 /*
  41  *      This routine purges all of the queues of frames.
  42  */
  43 void rose_clear_queues(struct sock *sk)
  44 {
  45         skb_queue_purge(&sk->write_queue);
  46         skb_queue_purge(&sk->protinfo.rose->ack_queue);
  47 }
  48
  49 /*
  50  * This routine purges the input queue of those frames that have been
  51  * acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the
  52  * SDL diagram.
  53  */
  54 void rose_frames_acked(struct sock *sk, unsigned short nr)
  55 {
  56         struct sk_buff *skb;
  57
  58         /*
  59          * Remove all the ack-ed frames from the ack queue.
  60          */
  61         if (sk->protinfo.rose->va != nr) {
  62                 while (skb_peek(&sk->protinfo.rose->ack_queue) != NULL && sk->protinfo.rose->va != nr) {
  63                         skb = skb_dequeue(&sk->protinfo.rose->ack_queue);
  64                         kfree_skb(skb);
  65                         sk->protinfo.rose->va = (sk->protinfo.rose->va + 1) % ROSE_MODULUS;
  66                 }
  67         }
  68 }
  69
  70 void rose_requeue_frames(struct sock *sk)
  71 {
  72         struct sk_buff *skb, *skb_prev = NULL;
  73
  74         /*
  75          * Requeue all the un-ack-ed frames on the output queue to be picked
  76          * up by rose_kick. This arrangement handles the possibility of an
  77          * empty output queue.
  78          */
  79         while ((skb = skb_dequeue(&sk->protinfo.rose->ack_queue)) != NULL) {
  80                 if (skb_prev == NULL)
  81                         skb_queue_head(&sk->write_queue, skb);
  82                 else
  83                         skb_append(skb_prev, skb);
  84                 skb_prev = skb;
  85         }
  86 }
  87
  88 /*
  89  *      Validate that the value of nr is between va and vs. Return true or
  90  *      false for testing.
  91  */
  92 int rose_validate_nr(struct sock *sk, unsigned short nr)
  93 {
  94         unsigned short vc = sk->protinfo.rose->va;
  95
  96         while (vc != sk->protinfo.rose->vs) {
  97                 if (nr == vc) return 1;
  98                 vc = (vc + 1) % ROSE_MODULUS;
  99         }
 100
 101         if (nr == sk->protinfo.rose->vs) return 1;
 102
 103         return 0;
 104 }
 105
 106 /*
 107  *  This routine is called when the packet layer internally generates a
 108  *  control frame.
 109  */
 110 void rose_write_internal(struct sock *sk, int frametype)
 111 {
 112         struct sk_buff *skb;
 113         unsigned char  *dptr;
 114         unsigned char  lci1, lci2;
 115         char buffer[100];
 116         int len, faclen = 0;
 117         int ax25_header_len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + 1;
 118
 119         len = ax25_header_len + ROSE_MIN_LEN;
 120
 121         switch (frametype) {
 122                 case ROSE_CALL_REQUEST:
 123                         len   += 1 + ROSE_ADDR_LEN + ROSE_ADDR_LEN;
 124                         faclen = rose_create_facilities(buffer, sk->protinfo.rose);
 125                         len   += faclen;
 126                         break;
 127                 case ROSE_CALL_ACCEPTED:
 128                 case ROSE_RESET_REQUEST:
 129                         len   += 2;
 130                         break;
 131                 case ROSE_CLEAR_REQUEST:
 132                         len   += 3;
 133                         /* facilities */
 134                         faclen = 3 + 2 + AX25_ADDR_LEN + 3 + ROSE_ADDR_LEN;
 135                         dptr = buffer;
 136                         *dptr++ = faclen-1;     /* Facilities length */
 137                         *dptr++ = 0;
 138                         *dptr++ = FAC_NATIONAL;
 139                         *dptr++ = FAC_NATIONAL_FAIL_CALL;
 140                         *dptr++ = AX25_ADDR_LEN;
 141                         memcpy(dptr, &rose_callsign, AX25_ADDR_LEN);
 142                         dptr += AX25_ADDR_LEN;
 143                         *dptr++ = FAC_NATIONAL_FAIL_ADD;
 144                         *dptr++ = ROSE_ADDR_LEN + 1;
 145                         *dptr++ = ROSE_ADDR_LEN * 2;
 146                         memcpy(dptr, &sk->protinfo.rose->source_addr, ROSE_ADDR_LEN);
 147                         len   += faclen;
 148                         break;
 149         }
 150
 151         if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
 152                 return;
 153
 154         /*
 155          *      Space for AX.25 header and PID.
 156          */
 157         skb_reserve(skb, ax25_header_len);
 158
 159         dptr = skb_put(skb, len - ax25_header_len);
 160
 161         lci1 = (sk->protinfo.rose->lci >> 8) & 0x0F;
 162         lci2 = (sk->protinfo.rose->lci >> 0) & 0xFF;
 163
 164         switch (frametype) {
 165
 166                 case ROSE_CALL_REQUEST:
 167                         *dptr++ = ROSE_GFI | lci1;
 168                         *dptr++ = lci2;
 169                         *dptr++ = frametype;
 170                         *dptr++ = 0xAA;
 171                         memcpy(dptr, &sk->protinfo.rose->dest_addr,  ROSE_ADDR_LEN);
 172                         dptr   += ROSE_ADDR_LEN;
 173                         memcpy(dptr, &sk->protinfo.rose->source_addr, ROSE_ADDR_LEN);
 174                         dptr   += ROSE_ADDR_LEN;
 175                         memcpy(dptr, buffer, faclen);
 176                         dptr   += faclen;
 177                         break;
 178
 179                 case ROSE_CALL_ACCEPTED:
 180                         *dptr++ = ROSE_GFI | lci1;
 181                         *dptr++ = lci2;
 182                         *dptr++ = frametype;
 183                         *dptr++ = 0x00;         /* Address length */
 184                         *dptr++ = 0;            /* Facilities length */
 185                         break;
 186
 187                 case ROSE_CLEAR_REQUEST:
 188                         *dptr++ = ROSE_GFI | lci1;
 189                         *dptr++ = lci2;
 190                         *dptr++ = frametype;
 191                         *dptr++ = sk->protinfo.rose->cause;
 192                         *dptr++ = sk->protinfo.rose->diagnostic;
 193                         *dptr++ = 0x00;         /* Address length */
 194                         memcpy(dptr, buffer, faclen);
 195                         dptr   += faclen;
 196                         break;
 197
 198                 case ROSE_RESET_REQUEST:
 199                         *dptr++ = ROSE_GFI | lci1;
 200                         *dptr++ = lci2;
 201                         *dptr++ = frametype;
 202                         *dptr++ = ROSE_DTE_ORIGINATED;
 203                         *dptr++ = 0;
 204                         break;
 205
 206                 case ROSE_RR:
 207                 case ROSE_RNR:
 208                         *dptr++ = ROSE_GFI | lci1;
 209                         *dptr++ = lci2;
 210                         *dptr   = frametype;
 211                         *dptr++ |= (sk->protinfo.rose->vr << 5) & 0xE0;
 212                         break;
 213
 214                 case ROSE_CLEAR_CONFIRMATION:
 215                 case ROSE_RESET_CONFIRMATION:
 216                         *dptr++ = ROSE_GFI | lci1;
 217                         *dptr++ = lci2;
 218                         *dptr++  = frametype;
 219                         break;
 220
 221                 default:
 222                         printk(KERN_ERR "ROSE: rose_write_internal - invalid frametype %02X\n", frametype);
 223                         kfree_skb(skb);
 224                         return;
 225         }
 226
 227         rose_transmit_link(skb, sk->protinfo.rose->neighbour);
 228 }
 229
 230 int rose_decode(struct sk_buff *skb, int *ns, int *nr, int *q, int *d, int *m)
 231 {
 232         unsigned char *frame;
 233
 234         frame = skb->data;
 235
 236         *ns = *nr = *q = *d = *m = 0;
 237
 238         switch (frame[2]) {
 239                 case ROSE_CALL_REQUEST:
 240                 case ROSE_CALL_ACCEPTED:
 241                 case ROSE_CLEAR_REQUEST:
 242                 case ROSE_CLEAR_CONFIRMATION:
 243                 case ROSE_RESET_REQUEST:
 244                 case ROSE_RESET_CONFIRMATION:
 245                         return frame[2];
 246                 default:
 247                         break;
 248         }
 249
 250         if ((frame[2] & 0x1F) == ROSE_RR  ||
 251             (frame[2] & 0x1F) == ROSE_RNR) {
 252                 *nr = (frame[2] >> 5) & 0x07;
 253                 return frame[2] & 0x1F;
 254         }
 255
 256         if ((frame[2] & 0x01) == ROSE_DATA) {
 257                 *q  = (frame[0] & ROSE_Q_BIT) == ROSE_Q_BIT;
 258                 *d  = (frame[0] & ROSE_D_BIT) == ROSE_D_BIT;
 259                 *m  = (frame[2] & ROSE_M_BIT) == ROSE_M_BIT;
 260                 *nr = (frame[2] >> 5) & 0x07;
 261                 *ns = (frame[2] >> 1) & 0x07;
 262                 return ROSE_DATA;
 263         }
 264
 265         return ROSE_ILLEGAL;
 266 }
 267
 268 static int rose_parse_national(unsigned char *p, struct rose_facilities_struct *facilities, int len)
 269 {
 270         unsigned char *pt;
 271         unsigned char l, lg, n = 0;
 272         int fac_national_digis_received = 0;
 273
 274         do {
 275                 switch (*p & 0xC0) {
 276                         case 0x00:
 277                                 p   += 2;
 278                                 n   += 2;
 279                                 len -= 2;
 280                                 break;
 281
 282                         case 0x40:
 283                                 if (*p == FAC_NATIONAL_RAND)
 284                                         facilities->rand = ((p[1] << 8) & 0xFF00) + ((p[2] << 0) & 0x00FF);
 285                                 p   += 3;
 286                                 n   += 3;
 287                                 len -= 3;
 288                                 break;
 289
 290                         case 0x80:
 291                                 p   += 4;
 292                                 n   += 4;
 293                                 len -= 4;
 294                                 break;
 295
 296                         case 0xC0:
 297                                 l = p[1];
 298                                 if (*p == FAC_NATIONAL_DEST_DIGI) {
 299                                         if (!fac_national_digis_received) {
 300                                                 memcpy(&facilities->source_digis[0], p + 2, AX25_ADDR_LEN);
 301                                                 facilities->source_ndigis = 1;
 302                                         }
 303                                 }
 304                                 else if (*p == FAC_NATIONAL_SRC_DIGI) {
 305                                         if (!fac_national_digis_received) {
 306                                                 memcpy(&facilities->dest_digis[0], p + 2, AX25_ADDR_LEN);
 307                                                 facilities->dest_ndigis = 1;
 308                                         }
 309                                 }
 310                                 else if (*p == FAC_NATIONAL_FAIL_CALL) {
 311                                         memcpy(&facilities->fail_call, p + 2, AX25_ADDR_LEN);
 312                                 }
 313                                 else if (*p == FAC_NATIONAL_FAIL_ADD) {
 314                                         memcpy(&facilities->fail_addr, p + 3, ROSE_ADDR_LEN);
 315                                 }
 316                                 else if (*p == FAC_NATIONAL_DIGIS) {
 317                                         fac_national_digis_received = 1;
 318                                         facilities->source_ndigis = 0;
 319                                         facilities->dest_ndigis   = 0;
 320                                         for (pt = p + 2, lg = 0 ; lg < l ; pt += AX25_ADDR_LEN, lg += AX25_ADDR_LEN) {
 321                                                 if (pt[6] & AX25_HBIT)
 322                                                         memcpy(&facilities->dest_digis[facilities->dest_ndigis++], pt, AX25_ADDR_LEN);
 323                                                 else
 324                                                         memcpy(&facilities->source_digis[facilities->source_ndigis++], pt, AX25_ADDR_LEN);
 325                                         }
 326                                 }
 327                                 p   += l + 2;
 328                                 n   += l + 2;
 329                                 len -= l + 2;
 330                                 break;
 331                 }
 332         } while (*p != 0x00 && len > 0);
 333
 334         return n;
 335 }
 336
 337 static int rose_parse_ccitt(unsigned char *p, struct rose_facilities_struct *facilities, int len)
 338 {
 339         unsigned char l, n = 0;
 340         char callsign[11];
 341
 342         do {
 343                 switch (*p & 0xC0) {
 344                         case 0x00:
 345                                 p   += 2;
 346                                 n   += 2;
 347                                 len -= 2;
 348                                 break;
 349
 350                         case 0x40:
 351                                 p   += 3;
 352                                 n   += 3;
 353                                 len -= 3;
 354                                 break;
 355
 356                         case 0x80:
 357                                 p   += 4;
 358                                 n   += 4;
 359                                 len -= 4;
 360                                 break;
 361
 362                         case 0xC0:
 363                                 l = p[1];
 364                                 if (*p == FAC_CCITT_DEST_NSAP) {
 365                                         memcpy(&facilities->source_addr, p + 7, ROSE_ADDR_LEN);
 366                                         memcpy(callsign, p + 12,   l - 10);
 367                                         callsign[l - 10] = '\0';
 368                                         facilities->source_call = *asc2ax(callsign);
 369                                 }
 370                                 if (*p == FAC_CCITT_SRC_NSAP) {
 371                                         memcpy(&facilities->dest_addr, p + 7, ROSE_ADDR_LEN);
 372                                         memcpy(callsign, p + 12, l - 10);
 373                                         callsign[l - 10] = '\0';
 374                                         facilities->dest_call = *asc2ax(callsign);
 375                                 }
 376                                 p   += l + 2;
 377                                 n   += l + 2;
 378                                 len -= l + 2;
 379                                 break;
 380                 }
 381         } while (*p != 0x00 && len > 0);
 382
 383         return n;
 384 }
 385
 386 int rose_parse_facilities(unsigned char *p, struct rose_facilities_struct *facilities)
 387 {
 388         int facilities_len, len;
 389
 390         facilities_len = *p++;
 391
 392         if (facilities_len == 0)
 393                 return 0;
 394
 395         while (facilities_len > 0) {
 396                 if (*p == 0x00) {
 397                         facilities_len--;
 398                         p++;
 399
 400                         switch (*p) {
 401                                 case FAC_NATIONAL:              /* National */
 402                                         len = rose_parse_national(p + 1, facilities, facilities_len - 1);
 403                                         facilities_len -= len + 1;
 404                                         p += len + 1;
 405                                         break;
 406
 407                                 case FAC_CCITT:         /* CCITT */
 408                                         len = rose_parse_ccitt(p + 1, facilities, facilities_len - 1);
 409                                         facilities_len -= len + 1;
 410                                         p += len + 1;
 411                                         break;
 412
 413                                 default:
 414                                         printk(KERN_DEBUG "ROSE: rose_parse_facilities - unknown facilities family %02X\n", *p);
 415                                         facilities_len--;
 416                                         p++;
 417                                         break;
 418                         }
 419                 }
 420                 else break;     /* Error in facilities format */
 421         }
 422
 423         return 1;
 424 }
 425
 426 int rose_create_facilities(unsigned char *buffer, rose_cb *rose)
 427 {
 428         unsigned char *p = buffer + 1;
 429         char *callsign;
 430         int len, nb;
 431
 432         /* National Facilities */
 433         if (rose->rand != 0 || rose->source_ndigis == 1 || rose->dest_ndigis == 1) {
 434                 *p++ = 0x00;
 435                 *p++ = FAC_NATIONAL;
 436
 437                 if (rose->rand != 0) {
 438                         *p++ = FAC_NATIONAL_RAND;
 439                         *p++ = (rose->rand >> 8) & 0xFF;
 440                         *p++ = (rose->rand >> 0) & 0xFF;
 441                 }
 442
 443                 /* Sent before older facilities */
 444                 if ((rose->source_ndigis > 0) || (rose->dest_ndigis > 0)) {
 445                         int maxdigi = 0;
 446                         *p++ = FAC_NATIONAL_DIGIS;
 447                         *p++ = AX25_ADDR_LEN * (rose->source_ndigis + rose->dest_ndigis);
 448                         for (nb = 0 ; nb < rose->source_ndigis ; nb++) {
 449                                 if (++maxdigi >= ROSE_MAX_DIGIS)
 450                                         break;
 451                                 memcpy(p, &rose->source_digis[nb], AX25_ADDR_LEN);
 452                                 p[6] |= AX25_HBIT;
 453                                 p += AX25_ADDR_LEN;
 454                         }
 455                         for (nb = 0 ; nb < rose->dest_ndigis ; nb++) {
 456                                 if (++maxdigi >= ROSE_MAX_DIGIS)
 457                                         break;
 458                                 memcpy(p, &rose->dest_digis[nb], AX25_ADDR_LEN);
 459                                 p[6] &= ~AX25_HBIT;
 460                                 p += AX25_ADDR_LEN;
 461                         }
 462                 }
 463
 464                 /* For compatibility */
 465                 if (rose->source_ndigis > 0) {
 466                         *p++ = FAC_NATIONAL_SRC_DIGI;
 467                         *p++ = AX25_ADDR_LEN;
 468                         memcpy(p, &rose->source_digis[0], AX25_ADDR_LEN);
 469                         p   += AX25_ADDR_LEN;
 470                 }
 471
 472                 /* For compatibility */
 473                 if (rose->dest_ndigis > 0) {
 474                         *p++ = FAC_NATIONAL_DEST_DIGI;
 475                         *p++ = AX25_ADDR_LEN;
 476                         memcpy(p, &rose->dest_digis[0], AX25_ADDR_LEN);
 477                         p   += AX25_ADDR_LEN;
 478                 }
 479         }
 480
 481         *p++ = 0x00;
 482         *p++ = FAC_CCITT;
 483
 484         *p++ = FAC_CCITT_DEST_NSAP;
 485
 486         callsign = ax2asc(&rose->dest_call);
 487
 488         *p++ = strlen(callsign) + 10;
 489         *p++ = (strlen(callsign) + 9) * 2;              /* ??? */
 490
 491         *p++ = 0x47; *p++ = 0x00; *p++ = 0x11;
 492         *p++ = ROSE_ADDR_LEN * 2;
 493         memcpy(p, &rose->dest_addr, ROSE_ADDR_LEN);
 494         p   += ROSE_ADDR_LEN;
 495
 496         memcpy(p, callsign, strlen(callsign));
 497         p   += strlen(callsign);
 498
 499         *p++ = FAC_CCITT_SRC_NSAP;
 500
 501         callsign = ax2asc(&rose->source_call);
 502
 503         *p++ = strlen(callsign) + 10;
 504         *p++ = (strlen(callsign) + 9) * 2;              /* ??? */
 505
 506         *p++ = 0x47; *p++ = 0x00; *p++ = 0x11;
 507         *p++ = ROSE_ADDR_LEN * 2;
 508         memcpy(p, &rose->source_addr, ROSE_ADDR_LEN);
 509         p   += ROSE_ADDR_LEN;
 510
 511         memcpy(p, callsign, strlen(callsign));
 512         p   += strlen(callsign);
 513
 514         len       = p - buffer;
 515         buffer[0] = len - 1;
 516
 517         return len;
 518 }
 519
 520 void rose_disconnect(struct sock *sk, int reason, int cause, int diagnostic)
 521 {
 522         rose_stop_timer(sk);
 523         rose_stop_idletimer(sk);
 524
 525         rose_clear_queues(sk);
 526
 527         sk->protinfo.rose->lci   = 0;
 528         sk->protinfo.rose->state = ROSE_STATE_0;
 529
 530         if (cause != -1)
 531                 sk->protinfo.rose->cause = cause;
 532
 533         if (diagnostic != -1)
 534                 sk->protinfo.rose->diagnostic = diagnostic;
 535
 536         sk->state     = TCP_CLOSE;
 537         sk->err       = reason;
 538         sk->shutdown |= SEND_SHUTDOWN;
 539
 540         if (!sk->dead)
 541                 sk->state_change(sk);
 542
 543         sk->dead  = 1;
 544 }