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++ = 0xAA;
 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                         p   += 2;
 250                         n   += 2;
 251                         len -= 2;
 252                         break;
 253
 254                 case 0x40:
 255                         if (*p == FAC_NATIONAL_RAND)
 256                                 facilities->rand = ((p[1] << 8) & 0xFF00) + ((p[2] << 0) & 0x00FF);
 257                         p   += 3;
 258                         n   += 3;
 259                         len -= 3;
 260                         break;
 261
 262                 case 0x80:
 263                         p   += 4;
 264                         n   += 4;
 265                         len -= 4;
 266                         break;
 267
 268                 case 0xC0:
 269                         l = p[1];
 270                         if (*p == FAC_NATIONAL_DEST_DIGI) {
 271                                 if (!fac_national_digis_received) {
 272                                         memcpy(&facilities->source_digis[0], p + 2, AX25_ADDR_LEN);
 273                                         facilities->source_ndigis = 1;
 274                                 }
 275                         }
 276                         else if (*p == FAC_NATIONAL_SRC_DIGI) {
 277                                 if (!fac_national_digis_received) {
 278                                         memcpy(&facilities->dest_digis[0], p + 2, AX25_ADDR_LEN);
 279                                         facilities->dest_ndigis = 1;
 280                                 }
 281                         }
 282                         else if (*p == FAC_NATIONAL_FAIL_CALL) {
 283                                 memcpy(&facilities->fail_call, p + 2, AX25_ADDR_LEN);
 284                         }
 285                         else if (*p == FAC_NATIONAL_FAIL_ADD) {
 286                                 memcpy(&facilities->fail_addr, p + 3, ROSE_ADDR_LEN);
 287                         }
 288                         else if (*p == FAC_NATIONAL_DIGIS) {
 289                                 fac_national_digis_received = 1;
 290                                 facilities->source_ndigis = 0;
 291                                 facilities->dest_ndigis   = 0;
 292                                 for (pt = p + 2, lg = 0 ; lg < l ; pt += AX25_ADDR_LEN, lg += AX25_ADDR_LEN) {
 293                                         if (pt[6] & AX25_HBIT)
 294                                                 memcpy(&facilities->dest_digis[facilities->dest_ndigis++], pt, AX25_ADDR_LEN);
 295                                         else
 296                                                 memcpy(&facilities->source_digis[facilities->source_ndigis++], pt, AX25_ADDR_LEN);
 297                                 }
 298                         }
 299                         p   += l + 2;
 300                         n   += l + 2;
 301                         len -= l + 2;
 302                         break;
 303                 }
 304         } while (*p != 0x00 && len > 0);
 305
 306         return n;
 307 }
 308
 309 static int rose_parse_ccitt(unsigned char *p, struct rose_facilities_struct *facilities, int len)
 310 {
 311         unsigned char l, n = 0;
 312         char callsign[11];
 313
 314         do {
 315                 switch (*p & 0xC0) {
 316                 case 0x00:
 317                         p   += 2;
 318                         n   += 2;
 319                         len -= 2;
 320                         break;
 321
 322                 case 0x40:
 323                         p   += 3;
 324                         n   += 3;
 325                         len -= 3;
 326                         break;
 327
 328                 case 0x80:
 329                         p   += 4;
 330                         n   += 4;
 331                         len -= 4;
 332                         break;
 333
 334                 case 0xC0:
 335                         l = p[1];
 336                         if (*p == FAC_CCITT_DEST_NSAP) {
 337                                 memcpy(&facilities->source_addr, p + 7, ROSE_ADDR_LEN);
 338                                 memcpy(callsign, p + 12,   l - 10);
 339                                 callsign[l - 10] = '\0';
 340                                 asc2ax(&facilities->source_call, callsign);
 341                         }
 342                         if (*p == FAC_CCITT_SRC_NSAP) {
 343                                 memcpy(&facilities->dest_addr, p + 7, ROSE_ADDR_LEN);
 344                                 memcpy(callsign, p + 12, l - 10);
 345                                 callsign[l - 10] = '\0';
 346                                 asc2ax(&facilities->dest_call, callsign);
 347                         }
 348                         p   += l + 2;
 349                         n   += l + 2;
 350                         len -= l + 2;
 351                         break;
 352                 }
 353         } while (*p != 0x00 && len > 0);
 354
 355         return n;
 356 }
 357
 358 int rose_parse_facilities(unsigned char *p,
 359         struct rose_facilities_struct *facilities)
 360 {
 361         int facilities_len, len;
 362
 363         facilities_len = *p++;
 364
 365         if (facilities_len == 0)
 366                 return 0;
 367
 368         while (facilities_len > 0) {
 369                 if (*p == 0x00) {
 370                         facilities_len--;
 371                         p++;
 372
 373                         switch (*p) {
 374                         case FAC_NATIONAL:              /* National */
 375                                 len = rose_parse_national(p + 1, facilities, facilities_len - 1);
 376                                 facilities_len -= len + 1;
 377                                 p += len + 1;
 378                                 break;
 379
 380                         case FAC_CCITT:         /* CCITT */
 381                                 len = rose_parse_ccitt(p + 1, facilities, facilities_len - 1);
 382                                 facilities_len -= len + 1;
 383                                 p += len + 1;
 384                                 break;
 385
 386                         default:
 387                                 printk(KERN_DEBUG "ROSE: rose_parse_facilities - unknown facilities family %02X\n", *p);
 388                                 facilities_len--;
 389                                 p++;
 390                                 break;
 391                         }
 392                 } else
 393                         break;  /* Error in facilities format */
 394         }
 395
 396         return 1;
 397 }
 398
 399 static int rose_create_facilities(unsigned char *buffer, struct rose_sock *rose)
 400 {
 401         unsigned char *p = buffer + 1;
 402         char *callsign;
 403         char buf[11];
 404         int len, nb;
 405
 406         /* National Facilities */
 407         if (rose->rand != 0 || rose->source_ndigis == 1 || rose->dest_ndigis == 1) {
 408                 *p++ = 0x00;
 409                 *p++ = FAC_NATIONAL;
 410
 411                 if (rose->rand != 0) {
 412                         *p++ = FAC_NATIONAL_RAND;
 413                         *p++ = (rose->rand >> 8) & 0xFF;
 414                         *p++ = (rose->rand >> 0) & 0xFF;
 415                 }
 416
 417                 /* Sent before older facilities */
 418                 if ((rose->source_ndigis > 0) || (rose->dest_ndigis > 0)) {
 419                         int maxdigi = 0;
 420                         *p++ = FAC_NATIONAL_DIGIS;
 421                         *p++ = AX25_ADDR_LEN * (rose->source_ndigis + rose->dest_ndigis);
 422                         for (nb = 0 ; nb < rose->source_ndigis ; nb++) {
 423                                 if (++maxdigi >= ROSE_MAX_DIGIS)
 424                                         break;
 425                                 memcpy(p, &rose->source_digis[nb], AX25_ADDR_LEN);
 426                                 p[6] |= AX25_HBIT;
 427                                 p += AX25_ADDR_LEN;
 428                         }
 429                         for (nb = 0 ; nb < rose->dest_ndigis ; nb++) {
 430                                 if (++maxdigi >= ROSE_MAX_DIGIS)
 431                                         break;
 432                                 memcpy(p, &rose->dest_digis[nb], AX25_ADDR_LEN);
 433                                 p[6] &= ~AX25_HBIT;
 434                                 p += AX25_ADDR_LEN;
 435                         }
 436                 }
 437
 438                 /* For compatibility */
 439                 if (rose->source_ndigis > 0) {
 440                         *p++ = FAC_NATIONAL_SRC_DIGI;
 441                         *p++ = AX25_ADDR_LEN;
 442                         memcpy(p, &rose->source_digis[0], AX25_ADDR_LEN);
 443                         p   += AX25_ADDR_LEN;
 444                 }
 445
 446                 /* For compatibility */
 447                 if (rose->dest_ndigis > 0) {
 448                         *p++ = FAC_NATIONAL_DEST_DIGI;
 449                         *p++ = AX25_ADDR_LEN;
 450                         memcpy(p, &rose->dest_digis[0], AX25_ADDR_LEN);
 451                         p   += AX25_ADDR_LEN;
 452                 }
 453         }
 454
 455         *p++ = 0x00;
 456         *p++ = FAC_CCITT;
 457
 458         *p++ = FAC_CCITT_DEST_NSAP;
 459
 460         callsign = ax2asc(buf, &rose->dest_call);
 461
 462         *p++ = strlen(callsign) + 10;
 463         *p++ = (strlen(callsign) + 9) * 2;              /* ??? */
 464
 465         *p++ = 0x47; *p++ = 0x00; *p++ = 0x11;
 466         *p++ = ROSE_ADDR_LEN * 2;
 467         memcpy(p, &rose->dest_addr, ROSE_ADDR_LEN);
 468         p   += ROSE_ADDR_LEN;
 469
 470         memcpy(p, callsign, strlen(callsign));
 471         p   += strlen(callsign);
 472
 473         *p++ = FAC_CCITT_SRC_NSAP;
 474
 475         callsign = ax2asc(buf, &rose->source_call);
 476
 477         *p++ = strlen(callsign) + 10;
 478         *p++ = (strlen(callsign) + 9) * 2;              /* ??? */
 479
 480         *p++ = 0x47; *p++ = 0x00; *p++ = 0x11;
 481         *p++ = ROSE_ADDR_LEN * 2;
 482         memcpy(p, &rose->source_addr, ROSE_ADDR_LEN);
 483         p   += ROSE_ADDR_LEN;
 484
 485         memcpy(p, callsign, strlen(callsign));
 486         p   += strlen(callsign);
 487
 488         len       = p - buffer;
 489         buffer[0] = len - 1;
 490
 491         return len;
 492 }
 493
 494 void rose_disconnect(struct sock *sk, int reason, int cause, int diagnostic)
 495 {
 496         struct rose_sock *rose = rose_sk(sk);
 497
 498         rose_stop_timer(sk);
 499         rose_stop_idletimer(sk);
 500
 501         rose_clear_queues(sk);
 502
 503         rose->lci   = 0;
 504         rose->state = ROSE_STATE_0;
 505
 506         if (cause != -1)
 507                 rose->cause = cause;
 508
 509         if (diagnostic != -1)
 510                 rose->diagnostic = diagnostic;
 511
 512         sk->sk_state     = TCP_CLOSE;
 513         sk->sk_err       = reason;
 514         sk->sk_shutdown |= SEND_SHUTDOWN;
 515
 516         if (!sock_flag(sk, SOCK_DEAD)) {
 517                 sk->sk_state_change(sk);
 518                 sock_set_flag(sk, SOCK_DEAD);
 519         }
 520 }