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/timer.h>
  15 #include <linux/string.h>
  16 #include <linux/sockios.h>
  17 #include <linux/net.h>
  18 #include <linux/slab.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_states.h>
  25 #include <linux/fcntl.h>
  26 #include <linux/mm.h>
  27 #include <linux/interrupt.h>
  28 #include <net/rose.h>
  29
  30 static int rose_create_facilities(unsigned char *buffer, struct rose_sock *rose);
  31
  32 /*
  33  *      This routine purges all of the queues of frames.
  34  */
  35 void rose_clear_queues(struct sock *sk)
  36 {
  37         skb_queue_purge(&sk->sk_write_queue);
  38         skb_queue_purge(&rose_sk(sk)->ack_queue);
  39 }
  40
  41 /*
  42  * This routine purges the input queue of those frames that have been
  43  * acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the
  44  * SDL diagram.
  45  */
  46 void rose_frames_acked(struct sock *sk, unsigned short nr)
  47 {
  48         struct sk_buff *skb;
  49         struct rose_sock *rose = rose_sk(sk);
  50
  51         /*
  52          * Remove all the ack-ed frames from the ack queue.
  53          */
  54         if (rose->va != nr) {
  55                 while (skb_peek(&rose->ack_queue) != NULL && rose->va != nr) {
  56                         skb = skb_dequeue(&rose->ack_queue);
  57                         kfree_skb(skb);
  58                         rose->va = (rose->va + 1) % ROSE_MODULUS;
  59                 }
  60         }
  61 }
  62
  63 void rose_requeue_frames(struct sock *sk)
  64 {
  65         struct sk_buff *skb, *skb_prev = NULL;
  66
  67         /*
  68          * Requeue all the un-ack-ed frames on the output queue to be picked
  69          * up by rose_kick. This arrangement handles the possibility of an
  70          * empty output queue.
  71          */
  72         while ((skb = skb_dequeue(&rose_sk(sk)->ack_queue)) != NULL) {
  73                 if (skb_prev == NULL)
  74                         skb_queue_head(&sk->sk_write_queue, skb);
  75                 else
  76                         skb_append(skb_prev, skb, &sk->sk_write_queue);
  77                 skb_prev = skb;
  78         }
  79 }
  80
  81 /*
  82  *      Validate that the value of nr is between va and vs. Return true or
  83  *      false for testing.
  84  */
  85 int rose_validate_nr(struct sock *sk, unsigned short nr)
  86 {
  87         struct rose_sock *rose = rose_sk(sk);
  88         unsigned short vc = rose->va;
  89
  90         while (vc != rose->vs) {
  91                 if (nr == vc) return 1;
  92                 vc = (vc + 1) % ROSE_MODULUS;
  93         }
  94
  95         return nr == rose->vs;
  96 }
  97
  98 /*
  99  *  This routine is called when the packet layer internally generates a
 100  *  control frame.
 101  */
 102 void rose_write_internal(struct sock *sk, int frametype)
 103 {
 104         struct rose_sock *rose = rose_sk(sk);
 105         struct sk_buff *skb;
 106         unsigned char  *dptr;
 107         unsigned char  lci1, lci2;
 108         int maxfaclen = 0;
 109         int len, faclen;
 110         int reserve;
 111
 112         reserve = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + 1;
 113         len = ROSE_MIN_LEN;
 114
 115         switch (frametype) {
 116         case ROSE_CALL_REQUEST:
 117                 len   += 1 + ROSE_ADDR_LEN + ROSE_ADDR_LEN;
 118                 maxfaclen = 256;
 119                 break;
 120         case ROSE_CALL_ACCEPTED:
 121         case ROSE_CLEAR_REQUEST:
 122         case ROSE_RESET_REQUEST:
 123                 len   += 2;
 124                 break;
 125         }
 126
 127         skb = alloc_skb(reserve + len + maxfaclen, GFP_ATOMIC);
 128         if (!skb)
 129                 return;
 130
 131         /*
 132          *      Space for AX.25 header and PID.
 133          */
 134         skb_reserve(skb, reserve);
 135
 136         dptr = skb_put(skb, len);
 137
 138         lci1 = (rose->lci >> 8) & 0x0F;
 139         lci2 = (rose->lci >> 0) & 0xFF;
 140
 141         switch (frametype) {
 142         case ROSE_CALL_REQUEST:
 143                 *dptr++ = ROSE_GFI | lci1;
 144                 *dptr++ = lci2;
 145                 *dptr++ = frametype;
 146                 *dptr++ = ROSE_CALL_REQ_ADDR_LEN_VAL;
 147                 memcpy(dptr, &rose->dest_addr,  ROSE_ADDR_LEN);
 148                 dptr   += ROSE_ADDR_LEN;
 149                 memcpy(dptr, &rose->source_addr, ROSE_ADDR_LEN);
 150                 dptr   += ROSE_ADDR_LEN;
 151                 faclen = rose_create_facilities(dptr, rose);
 152                 skb_put(skb, faclen);
 153                 dptr   += faclen;
 154                 break;
 155
 156         case ROSE_CALL_ACCEPTED:
 157                 *dptr++ = ROSE_GFI | lci1;
 158                 *dptr++ = lci2;
 159                 *dptr++ = frametype;
 160                 *dptr++ = 0x00;         /* Address length */
 161                 *dptr++ = 0;            /* Facilities length */
 162                 break;
 163
 164         case ROSE_CLEAR_REQUEST:
 165                 *dptr++ = ROSE_GFI | lci1;
 166                 *dptr++ = lci2;
 167                 *dptr++ = frametype;
 168                 *dptr++ = rose->cause;
 169                 *dptr++ = rose->diagnostic;
 170                 break;
 171
 172         case ROSE_RESET_REQUEST:
 173                 *dptr++ = ROSE_GFI | lci1;
 174                 *dptr++ = lci2;
 175                 *dptr++ = frametype;
 176                 *dptr++ = ROSE_DTE_ORIGINATED;
 177                 *dptr++ = 0;
 178                 break;
 179
 180         case ROSE_RR:
 181         case ROSE_RNR:
 182                 *dptr++ = ROSE_GFI | lci1;
 183                 *dptr++ = lci2;
 184                 *dptr   = frametype;
 185                 *dptr++ |= (rose->vr << 5) & 0xE0;
 186                 break;
 187
 188         case ROSE_CLEAR_CONFIRMATION:
 189         case ROSE_RESET_CONFIRMATION:
 190                 *dptr++ = ROSE_GFI | lci1;
 191                 *dptr++ = lci2;
 192                 *dptr++  = frametype;
 193                 break;
 194
 195         default:
 196                 printk(KERN_ERR "ROSE: rose_write_internal - invalid frametype %02X\n", frametype);
 197                 kfree_skb(skb);
 198                 return;
 199         }
 200
 201         rose_transmit_link(skb, rose->neighbour);
 202 }
 203
 204 int rose_decode(struct sk_buff *skb, int *ns, int *nr, int *q, int *d, int *m)
 205 {
 206         unsigned char *frame;
 207
 208         frame = skb->data;
 209
 210         *ns = *nr = *q = *d = *m = 0;
 211
 212         switch (frame[2]) {
 213         case ROSE_CALL_REQUEST:
 214         case ROSE_CALL_ACCEPTED:
 215         case ROSE_CLEAR_REQUEST:
 216         case ROSE_CLEAR_CONFIRMATION:
 217         case ROSE_RESET_REQUEST:
 218         case ROSE_RESET_CONFIRMATION:
 219                 return frame[2];
 220         default:
 221                 break;
 222         }
 223
 224         if ((frame[2] & 0x1F) == ROSE_RR  ||
 225             (frame[2] & 0x1F) == ROSE_RNR) {
 226                 *nr = (frame[2] >> 5) & 0x07;
 227                 return frame[2] & 0x1F;
 228         }
 229
 230         if ((frame[2] & 0x01) == ROSE_DATA) {
 231                 *q  = (frame[0] & ROSE_Q_BIT) == ROSE_Q_BIT;
 232                 *d  = (frame[0] & ROSE_D_BIT) == ROSE_D_BIT;
 233                 *m  = (frame[2] & ROSE_M_BIT) == ROSE_M_BIT;
 234                 *nr = (frame[2] >> 5) & 0x07;
 235                 *ns = (frame[2] >> 1) & 0x07;
 236                 return ROSE_DATA;
 237         }
 238
 239         return ROSE_ILLEGAL;
 240 }
 241
 242 static int rose_parse_national(unsigned char *p, struct rose_facilities_struct *facilities, int len)
 243 {
 244         unsigned char *pt;
 245         unsigned char l, lg, n = 0;
 246         int fac_national_digis_received = 0;
 247
 248         do {
 249                 switch (*p & 0xC0) {
 250                 case 0x00:
 251                         if (len < 2)
 252                                 return -1;
 253                         p   += 2;
 254                         n   += 2;
 255                         len -= 2;
 256                         break;
 257
 258                 case 0x40:
 259                         if (len < 3)
 260                                 return -1;
 261                         if (*p == FAC_NATIONAL_RAND)
 262                                 facilities->rand = ((p[1] << 8) & 0xFF00) + ((p[2] << 0) & 0x00FF);
 263                         p   += 3;
 264                         n   += 3;
 265                         len -= 3;
 266                         break;
 267
 268                 case 0x80:
 269                         if (len < 4)
 270                                 return -1;
 271                         p   += 4;
 272                         n   += 4;
 273                         len -= 4;
 274                         break;
 275
 276                 case 0xC0:
 277                         if (len < 2)
 278                                 return -1;
 279                         l = p[1];
 280                         if (len < 2 + l)
 281                                 return -1;
 282                         if (*p == FAC_NATIONAL_DEST_DIGI) {
 283                                 if (!fac_national_digis_received) {
 284                                         if (l < AX25_ADDR_LEN)
 285                                                 return -1;
 286                                         memcpy(&facilities->source_digis[0], p + 2, AX25_ADDR_LEN);
 287                                         facilities->source_ndigis = 1;
 288                                 }
 289                         }
 290                         else if (*p == FAC_NATIONAL_SRC_DIGI) {
 291                                 if (!fac_national_digis_received) {
 292                                         if (l < AX25_ADDR_LEN)
 293                                                 return -1;
 294                                         memcpy(&facilities->dest_digis[0], p + 2, AX25_ADDR_LEN);
 295                                         facilities->dest_ndigis = 1;
 296                                 }
 297                         }
 298                         else if (*p == FAC_NATIONAL_FAIL_CALL) {
 299                                 if (l < AX25_ADDR_LEN)
 300                                         return -1;
 301                                 memcpy(&facilities->fail_call, p + 2, AX25_ADDR_LEN);
 302                         }
 303                         else if (*p == FAC_NATIONAL_FAIL_ADD) {
 304                                 if (l < 1 + ROSE_ADDR_LEN)
 305                                         return -1;
 306                                 memcpy(&facilities->fail_addr, p + 3, ROSE_ADDR_LEN);
 307                         }
 308                         else if (*p == FAC_NATIONAL_DIGIS) {
 309                                 if (l % AX25_ADDR_LEN)
 310                                         return -1;
 311                                 fac_national_digis_received = 1;
 312                                 facilities->source_ndigis = 0;
 313                                 facilities->dest_ndigis   = 0;
 314                                 for (pt = p + 2, lg = 0 ; lg < l ; pt += AX25_ADDR_LEN, lg += AX25_ADDR_LEN) {
 315                                         if (pt[6] & AX25_HBIT) {
 316                                                 if (facilities->dest_ndigis >= ROSE_MAX_DIGIS)
 317                                                         return -1;
 318                                                 memcpy(&facilities->dest_digis[facilities->dest_ndigis++], pt, AX25_ADDR_LEN);
 319                                         } else {
 320                                                 if (facilities->source_ndigis >= ROSE_MAX_DIGIS)
 321                                                         return -1;
 322                                                 memcpy(&facilities->source_digis[facilities->source_ndigis++], pt, AX25_ADDR_LEN);
 323                                         }
 324                                 }
 325                         }
 326                         p   += l + 2;
 327                         n   += l + 2;
 328                         len -= l + 2;
 329                         break;
 330                 }
 331         } while (*p != 0x00 && len > 0);
 332
 333         return n;
 334 }
 335
 336 static int rose_parse_ccitt(unsigned char *p, struct rose_facilities_struct *facilities, int len)
 337 {
 338         unsigned char l, n = 0;
 339         char callsign[11];
 340
 341         do {
 342                 switch (*p & 0xC0) {
 343                 case 0x00:
 344                         if (len < 2)
 345                                 return -1;
 346                         p   += 2;
 347                         n   += 2;
 348                         len -= 2;
 349                         break;
 350
 351                 case 0x40:
 352                         if (len < 3)
 353                                 return -1;
 354                         p   += 3;
 355                         n   += 3;
 356                         len -= 3;
 357                         break;
 358
 359                 case 0x80:
 360                         if (len < 4)
 361                                 return -1;
 362                         p   += 4;
 363                         n   += 4;
 364                         len -= 4;
 365                         break;
 366
 367                 case 0xC0:
 368                         if (len < 2)
 369                                 return -1;
 370                         l = p[1];
 371
 372                         /* Prevent overflows*/
 373                         if (l < 10 || l > 20)
 374                                 return -1;
 375
 376                         if (*p == FAC_CCITT_DEST_NSAP) {
 377                                 memcpy(&facilities->source_addr, p + 7, ROSE_ADDR_LEN);
 378                                 memcpy(callsign, p + 12,   l - 10);
 379                                 callsign[l - 10] = '\0';
 380                                 asc2ax(&facilities->source_call, callsign);
 381                         }
 382                         if (*p == FAC_CCITT_SRC_NSAP) {
 383                                 memcpy(&facilities->dest_addr, p + 7, ROSE_ADDR_LEN);
 384                                 memcpy(callsign, p + 12, l - 10);
 385                                 callsign[l - 10] = '\0';
 386                                 asc2ax(&facilities->dest_call, callsign);
 387                         }
 388                         p   += l + 2;
 389                         n   += l + 2;
 390                         len -= l + 2;
 391                         break;
 392                 }
 393         } while (*p != 0x00 && len > 0);
 394
 395         return n;
 396 }
 397
 398 int rose_parse_facilities(unsigned char *p, unsigned packet_len,
 399         struct rose_facilities_struct *facilities)
 400 {
 401         int facilities_len, len;
 402
 403         facilities_len = *p++;
 404
 405         if (facilities_len == 0 || (unsigned int)facilities_len > packet_len)
 406                 return 0;
 407
 408         while (facilities_len >= 3 && *p == 0x00) {
 409                 facilities_len--;
 410                 p++;
 411
 412                 switch (*p) {
 413                 case FAC_NATIONAL:              /* National */
 414                         len = rose_parse_national(p + 1, facilities, facilities_len - 1);
 415                         break;
 416
 417                 case FAC_CCITT:         /* CCITT */
 418                         len = rose_parse_ccitt(p + 1, facilities, facilities_len - 1);
 419                         break;
 420
 421                 default:
 422                         printk(KERN_DEBUG "ROSE: rose_parse_facilities - unknown facilities family %02X\n", *p);
 423                         len = 1;
 424                         break;
 425                 }
 426
 427                 if (len < 0)
 428                         return 0;
 429                 if (WARN_ON(len >= facilities_len))
 430                         return 0;
 431                 facilities_len -= len + 1;
 432                 p += len + 1;
 433         }
 434
 435         return facilities_len == 0;
 436 }
 437
 438 static int rose_create_facilities(unsigned char *buffer, struct rose_sock *rose)
 439 {
 440         unsigned char *p = buffer + 1;
 441         char *callsign;
 442         char buf[11];
 443         int len, nb;
 444
 445         /* National Facilities */
 446         if (rose->rand != 0 || rose->source_ndigis == 1 || rose->dest_ndigis == 1) {
 447                 *p++ = 0x00;
 448                 *p++ = FAC_NATIONAL;
 449
 450                 if (rose->rand != 0) {
 451                         *p++ = FAC_NATIONAL_RAND;
 452                         *p++ = (rose->rand >> 8) & 0xFF;
 453                         *p++ = (rose->rand >> 0) & 0xFF;
 454                 }
 455
 456                 /* Sent before older facilities */
 457                 if ((rose->source_ndigis > 0) || (rose->dest_ndigis > 0)) {
 458                         int maxdigi = 0;
 459                         *p++ = FAC_NATIONAL_DIGIS;
 460                         *p++ = AX25_ADDR_LEN * (rose->source_ndigis + rose->dest_ndigis);
 461                         for (nb = 0 ; nb < rose->source_ndigis ; nb++) {
 462                                 if (++maxdigi >= ROSE_MAX_DIGIS)
 463                                         break;
 464                                 memcpy(p, &rose->source_digis[nb], AX25_ADDR_LEN);
 465                                 p[6] |= AX25_HBIT;
 466                                 p += AX25_ADDR_LEN;
 467                         }
 468                         for (nb = 0 ; nb < rose->dest_ndigis ; nb++) {
 469                                 if (++maxdigi >= ROSE_MAX_DIGIS)
 470                                         break;
 471                                 memcpy(p, &rose->dest_digis[nb], AX25_ADDR_LEN);
 472                                 p[6] &= ~AX25_HBIT;
 473                                 p += AX25_ADDR_LEN;
 474                         }
 475                 }
 476
 477                 /* For compatibility */
 478                 if (rose->source_ndigis > 0) {
 479                         *p++ = FAC_NATIONAL_SRC_DIGI;
 480                         *p++ = AX25_ADDR_LEN;
 481                         memcpy(p, &rose->source_digis[0], AX25_ADDR_LEN);
 482                         p   += AX25_ADDR_LEN;
 483                 }
 484
 485                 /* For compatibility */
 486                 if (rose->dest_ndigis > 0) {
 487                         *p++ = FAC_NATIONAL_DEST_DIGI;
 488                         *p++ = AX25_ADDR_LEN;
 489                         memcpy(p, &rose->dest_digis[0], AX25_ADDR_LEN);
 490                         p   += AX25_ADDR_LEN;
 491                 }
 492         }
 493
 494         *p++ = 0x00;
 495         *p++ = FAC_CCITT;
 496
 497         *p++ = FAC_CCITT_DEST_NSAP;
 498
 499         callsign = ax2asc(buf, &rose->dest_call);
 500
 501         *p++ = strlen(callsign) + 10;
 502         *p++ = (strlen(callsign) + 9) * 2;              /* ??? */
 503
 504         *p++ = 0x47; *p++ = 0x00; *p++ = 0x11;
 505         *p++ = ROSE_ADDR_LEN * 2;
 506         memcpy(p, &rose->dest_addr, ROSE_ADDR_LEN);
 507         p   += ROSE_ADDR_LEN;
 508
 509         memcpy(p, callsign, strlen(callsign));
 510         p   += strlen(callsign);
 511
 512         *p++ = FAC_CCITT_SRC_NSAP;
 513
 514         callsign = ax2asc(buf, &rose->source_call);
 515
 516         *p++ = strlen(callsign) + 10;
 517         *p++ = (strlen(callsign) + 9) * 2;              /* ??? */
 518
 519         *p++ = 0x47; *p++ = 0x00; *p++ = 0x11;
 520         *p++ = ROSE_ADDR_LEN * 2;
 521         memcpy(p, &rose->source_addr, ROSE_ADDR_LEN);
 522         p   += ROSE_ADDR_LEN;
 523
 524         memcpy(p, callsign, strlen(callsign));
 525         p   += strlen(callsign);
 526
 527         len       = p - buffer;
 528         buffer[0] = len - 1;
 529
 530         return len;
 531 }
 532
 533 void rose_disconnect(struct sock *sk, int reason, int cause, int diagnostic)
 534 {
 535         struct rose_sock *rose = rose_sk(sk);
 536
 537         rose_stop_timer(sk);
 538         rose_stop_idletimer(sk);
 539
 540         rose_clear_queues(sk);
 541
 542         rose->lci   = 0;
 543         rose->state = ROSE_STATE_0;
 544
 545         if (cause != -1)
 546                 rose->cause = cause;
 547
 548         if (diagnostic != -1)
 549                 rose->diagnostic = diagnostic;
 550
 551         sk->sk_state     = TCP_CLOSE;
 552         sk->sk_err       = reason;
 553         sk->sk_shutdown |= SEND_SHUTDOWN;
 554
 555         if (!sock_flag(sk, SOCK_DEAD)) {
 556                 sk->sk_state_change(sk);
 557                 sock_set_flag(sk, SOCK_DEAD);
 558         }
 559 }