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