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