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 <net/ax25.h>
  19 #include <linux/inet.h>
  20 #include <linux/netdevice.h>
  21 #include <linux/skbuff.h>
  22 #include <net/sock.h>
  23 #include <net/tcp_states.h>
  24 #include <asm/system.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         char buffer[100];
 109         int len, faclen = 0;
 110
 111         len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 1;
 112
 113         switch (frametype) {
 114         case ROSE_CALL_REQUEST:
 115                 len   += 1 + ROSE_ADDR_LEN + ROSE_ADDR_LEN;
 116                 faclen = rose_create_facilities(buffer, rose);
 117                 len   += faclen;
 118                 break;
 119         case ROSE_CALL_ACCEPTED:
 120         case ROSE_CLEAR_REQUEST:
 121         case ROSE_RESET_REQUEST:
 122                 len   += 2;
 123                 break;
 124         }
 125
 126         if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
 127                 return;
 128
 129         /*
 130          *      Space for AX.25 header and PID.
 131          */
 132         skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + 1);
 133
 134         dptr = skb_put(skb, skb_tailroom(skb));
 135
 136         lci1 = (rose->lci >> 8) & 0x0F;
 137         lci2 = (rose->lci >> 0) & 0xFF;
 138
 139         switch (frametype) {
 140         case ROSE_CALL_REQUEST:
 141                 *dptr++ = ROSE_GFI | lci1;
 142                 *dptr++ = lci2;
 143                 *dptr++ = frametype;
 144                 *dptr++ = 0xAA;
 145                 memcpy(dptr, &rose->dest_addr,  ROSE_ADDR_LEN);
 146                 dptr   += ROSE_ADDR_LEN;
 147                 memcpy(dptr, &rose->source_addr, ROSE_ADDR_LEN);
 148                 dptr   += ROSE_ADDR_LEN;
 149                 memcpy(dptr, buffer, faclen);
 150                 dptr   += faclen;
 151                 break;
 152
 153         case ROSE_CALL_ACCEPTED:
 154                 *dptr++ = ROSE_GFI | lci1;
 155                 *dptr++ = lci2;
 156                 *dptr++ = frametype;
 157                 *dptr++ = 0x00;         /* Address length */
 158                 *dptr++ = 0;            /* Facilities length */
 159                 break;
 160
 161         case ROSE_CLEAR_REQUEST:
 162                 *dptr++ = ROSE_GFI | lci1;
 163                 *dptr++ = lci2;
 164                 *dptr++ = frametype;
 165                 *dptr++ = rose->cause;
 166                 *dptr++ = rose->diagnostic;
 167                 break;
 168
 169         case ROSE_RESET_REQUEST:
 170                 *dptr++ = ROSE_GFI | lci1;
 171                 *dptr++ = lci2;
 172                 *dptr++ = frametype;
 173                 *dptr++ = ROSE_DTE_ORIGINATED;
 174                 *dptr++ = 0;
 175                 break;
 176
 177         case ROSE_RR:
 178         case ROSE_RNR:
 179                 *dptr++ = ROSE_GFI | lci1;
 180                 *dptr++ = lci2;
 181                 *dptr   = frametype;
 182                 *dptr++ |= (rose->vr << 5) & 0xE0;
 183                 break;
 184
 185         case ROSE_CLEAR_CONFIRMATION:
 186         case ROSE_RESET_CONFIRMATION:
 187                 *dptr++ = ROSE_GFI | lci1;
 188                 *dptr++ = lci2;
 189                 *dptr++  = frametype;
 190                 break;
 191
 192         default:
 193                 printk(KERN_ERR "ROSE: rose_write_internal - invalid frametype %02X\n", frametype);
 194                 kfree_skb(skb);
 195                 return;
 196         }
 197
 198         rose_transmit_link(skb, rose->neighbour);
 199 }
 200
 201 int rose_decode(struct sk_buff *skb, int *ns, int *nr, int *q, int *d, int *m)
 202 {
 203         unsigned char *frame;
 204
 205         frame = skb->data;
 206
 207         *ns = *nr = *q = *d = *m = 0;
 208
 209         switch (frame[2]) {
 210         case ROSE_CALL_REQUEST:
 211         case ROSE_CALL_ACCEPTED:
 212         case ROSE_CLEAR_REQUEST:
 213         case ROSE_CLEAR_CONFIRMATION:
 214         case ROSE_RESET_REQUEST:
 215         case ROSE_RESET_CONFIRMATION:
 216                 return frame[2];
 217         default:
 218                 break;
 219         }
 220
 221         if ((frame[2] & 0x1F) == ROSE_RR  ||
 222             (frame[2] & 0x1F) == ROSE_RNR) {
 223                 *nr = (frame[2] >> 5) & 0x07;
 224                 return frame[2] & 0x1F;
 225         }
 226
 227         if ((frame[2] & 0x01) == ROSE_DATA) {
 228                 *q  = (frame[0] & ROSE_Q_BIT) == ROSE_Q_BIT;
 229                 *d  = (frame[0] & ROSE_D_BIT) == ROSE_D_BIT;
 230                 *m  = (frame[2] & ROSE_M_BIT) == ROSE_M_BIT;
 231                 *nr = (frame[2] >> 5) & 0x07;
 232                 *ns = (frame[2] >> 1) & 0x07;
 233                 return ROSE_DATA;
 234         }
 235
 236         return ROSE_ILLEGAL;
 237 }
 238
 239 static int rose_parse_national(unsigned char *p, struct rose_facilities_struct *facilities, int len)
 240 {
 241         unsigned char *pt;
 242         unsigned char l, lg, n = 0;
 243         int fac_national_digis_received = 0;
 244
 245         do {
 246                 switch (*p & 0xC0) {
 247                 case 0x00:
 248                         p   += 2;
 249                         n   += 2;
 250                         len -= 2;
 251                         break;
 252
 253                 case 0x40:
 254                         if (*p == FAC_NATIONAL_RAND)
 255                                 facilities->rand = ((p[1] << 8) & 0xFF00) + ((p[2] << 0) & 0x00FF);
 256                         p   += 3;
 257                         n   += 3;
 258                         len -= 3;
 259                         break;
 260
 261                 case 0x80:
 262                         p   += 4;
 263                         n   += 4;
 264                         len -= 4;
 265                         break;
 266
 267                 case 0xC0:
 268                         l = p[1];
 269                         if (*p == FAC_NATIONAL_DEST_DIGI) {
 270                                 if (!fac_national_digis_received) {
 271                                         memcpy(&facilities->source_digis[0], p + 2, AX25_ADDR_LEN);
 272                                         facilities->source_ndigis = 1;
 273                                 }
 274                         }
 275                         else if (*p == FAC_NATIONAL_SRC_DIGI) {
 276                                 if (!fac_national_digis_received) {
 277                                         memcpy(&facilities->dest_digis[0], p + 2, AX25_ADDR_LEN);
 278                                         facilities->dest_ndigis = 1;
 279                                 }
 280                         }
 281                         else if (*p == FAC_NATIONAL_FAIL_CALL) {
 282                                 memcpy(&facilities->fail_call, p + 2, AX25_ADDR_LEN);
 283                         }
 284                         else if (*p == FAC_NATIONAL_FAIL_ADD) {
 285                                 memcpy(&facilities->fail_addr, p + 3, ROSE_ADDR_LEN);
 286                         }
 287                         else if (*p == FAC_NATIONAL_DIGIS) {
 288                                 fac_national_digis_received = 1;
 289                                 facilities->source_ndigis = 0;
 290                                 facilities->dest_ndigis   = 0;
 291                                 for (pt = p + 2, lg = 0 ; lg < l ; pt += AX25_ADDR_LEN, lg += AX25_ADDR_LEN) {
 292                                         if (pt[6] & AX25_HBIT) {
 293                                                 if (facilities->dest_ndigis >= ROSE_MAX_DIGIS)
 294                                                         return -1;
 295                                                 memcpy(&facilities->dest_digis[facilities->dest_ndigis++], pt, AX25_ADDR_LEN);
 296                                         } else {
 297                                                 if (facilities->source_ndigis >= ROSE_MAX_DIGIS)
 298                                                         return -1;
 299                                                 memcpy(&facilities->source_digis[facilities->source_ndigis++], pt, AX25_ADDR_LEN);
 300                                         }
 301                                 }
 302                         }
 303                         p   += l + 2;
 304                         n   += l + 2;
 305                         len -= l + 2;
 306                         break;
 307                 }
 308         } while (*p != 0x00 && len > 0);
 309
 310         return n;
 311 }
 312
 313 static int rose_parse_ccitt(unsigned char *p, struct rose_facilities_struct *facilities, int len)
 314 {
 315         unsigned char l, n = 0;
 316         char callsign[11];
 317
 318         do {
 319                 switch (*p & 0xC0) {
 320                 case 0x00:
 321                         p   += 2;
 322                         n   += 2;
 323                         len -= 2;
 324                         break;
 325
 326                 case 0x40:
 327                         p   += 3;
 328                         n   += 3;
 329                         len -= 3;
 330                         break;
 331
 332                 case 0x80:
 333                         p   += 4;
 334                         n   += 4;
 335                         len -= 4;
 336                         break;
 337
 338                 case 0xC0:
 339                         l = p[1];
 340
 341                         /* Prevent overflows*/
 342                         if (l < 10 || l > 20)
 343                                 return -1;
 344
 345                         if (*p == FAC_CCITT_DEST_NSAP) {
 346                                 memcpy(&facilities->source_addr, p + 7, ROSE_ADDR_LEN);
 347                                 memcpy(callsign, p + 12,   l - 10);
 348                                 callsign[l - 10] = '\0';
 349                                 asc2ax(&facilities->source_call, callsign);
 350                         }
 351                         if (*p == FAC_CCITT_SRC_NSAP) {
 352                                 memcpy(&facilities->dest_addr, p + 7, ROSE_ADDR_LEN);
 353                                 memcpy(callsign, p + 12, l - 10);
 354                                 callsign[l - 10] = '\0';
 355                                 asc2ax(&facilities->dest_call, callsign);
 356                         }
 357                         p   += l + 2;
 358                         n   += l + 2;
 359                         len -= l + 2;
 360                         break;
 361                 }
 362         } while (*p != 0x00 && len > 0);
 363
 364         return n;
 365 }
 366
 367 int rose_parse_facilities(unsigned char *p,
 368         struct rose_facilities_struct *facilities)
 369 {
 370         int facilities_len, len;
 371
 372         facilities_len = *p++;
 373
 374         if (facilities_len == 0)
 375                 return 0;
 376
 377         while (facilities_len > 0) {
 378                 if (*p == 0x00) {
 379                         facilities_len--;
 380                         p++;
 381
 382                         switch (*p) {
 383                         case FAC_NATIONAL:              /* National */
 384                                 len = rose_parse_national(p + 1, facilities, facilities_len - 1);
 385                                 if (len < 0)
 386                                         return 0;
 387                                 facilities_len -= len + 1;
 388                                 p += len + 1;
 389                                 break;
 390
 391                         case FAC_CCITT:         /* CCITT */
 392                                 len = rose_parse_ccitt(p + 1, facilities, facilities_len - 1);
 393                                 if (len < 0)
 394                                         return 0;
 395                                 facilities_len -= len + 1;
 396                                 p += len + 1;
 397                                 break;
 398
 399                         default:
 400                                 printk(KERN_DEBUG "ROSE: rose_parse_facilities - unknown facilities family %02X\n", *p);
 401                                 facilities_len--;
 402                                 p++;
 403                                 break;
 404                         }
 405                 } else
 406                         break;  /* Error in facilities format */
 407         }
 408
 409         return 1;
 410 }
 411
 412 static int rose_create_facilities(unsigned char *buffer, struct rose_sock *rose)
 413 {
 414         unsigned char *p = buffer + 1;
 415         char *callsign;
 416         char buf[11];
 417         int len, nb;
 418
 419         /* National Facilities */
 420         if (rose->rand != 0 || rose->source_ndigis == 1 || rose->dest_ndigis == 1) {
 421                 *p++ = 0x00;
 422                 *p++ = FAC_NATIONAL;
 423
 424                 if (rose->rand != 0) {
 425                         *p++ = FAC_NATIONAL_RAND;
 426                         *p++ = (rose->rand >> 8) & 0xFF;
 427                         *p++ = (rose->rand >> 0) & 0xFF;
 428                 }
 429
 430                 /* Sent before older facilities */
 431                 if ((rose->source_ndigis > 0) || (rose->dest_ndigis > 0)) {
 432                         int maxdigi = 0;
 433                         *p++ = FAC_NATIONAL_DIGIS;
 434                         *p++ = AX25_ADDR_LEN * (rose->source_ndigis + rose->dest_ndigis);
 435                         for (nb = 0 ; nb < rose->source_ndigis ; nb++) {
 436                                 if (++maxdigi >= ROSE_MAX_DIGIS)
 437                                         break;
 438                                 memcpy(p, &rose->source_digis[nb], AX25_ADDR_LEN);
 439                                 p[6] |= AX25_HBIT;
 440                                 p += AX25_ADDR_LEN;
 441                         }
 442                         for (nb = 0 ; nb < rose->dest_ndigis ; nb++) {
 443                                 if (++maxdigi >= ROSE_MAX_DIGIS)
 444                                         break;
 445                                 memcpy(p, &rose->dest_digis[nb], AX25_ADDR_LEN);
 446                                 p[6] &= ~AX25_HBIT;
 447                                 p += AX25_ADDR_LEN;
 448                         }
 449                 }
 450
 451                 /* For compatibility */
 452                 if (rose->source_ndigis > 0) {
 453                         *p++ = FAC_NATIONAL_SRC_DIGI;
 454                         *p++ = AX25_ADDR_LEN;
 455                         memcpy(p, &rose->source_digis[0], AX25_ADDR_LEN);
 456                         p   += AX25_ADDR_LEN;
 457                 }
 458
 459                 /* For compatibility */
 460                 if (rose->dest_ndigis > 0) {
 461                         *p++ = FAC_NATIONAL_DEST_DIGI;
 462                         *p++ = AX25_ADDR_LEN;
 463                         memcpy(p, &rose->dest_digis[0], AX25_ADDR_LEN);
 464                         p   += AX25_ADDR_LEN;
 465                 }
 466         }
 467
 468         *p++ = 0x00;
 469         *p++ = FAC_CCITT;
 470
 471         *p++ = FAC_CCITT_DEST_NSAP;
 472
 473         callsign = ax2asc(buf, &rose->dest_call);
 474
 475         *p++ = strlen(callsign) + 10;
 476         *p++ = (strlen(callsign) + 9) * 2;              /* ??? */
 477
 478         *p++ = 0x47; *p++ = 0x00; *p++ = 0x11;
 479         *p++ = ROSE_ADDR_LEN * 2;
 480         memcpy(p, &rose->dest_addr, ROSE_ADDR_LEN);
 481         p   += ROSE_ADDR_LEN;
 482
 483         memcpy(p, callsign, strlen(callsign));
 484         p   += strlen(callsign);
 485
 486         *p++ = FAC_CCITT_SRC_NSAP;
 487
 488         callsign = ax2asc(buf, &rose->source_call);
 489
 490         *p++ = strlen(callsign) + 10;
 491         *p++ = (strlen(callsign) + 9) * 2;              /* ??? */
 492
 493         *p++ = 0x47; *p++ = 0x00; *p++ = 0x11;
 494         *p++ = ROSE_ADDR_LEN * 2;
 495         memcpy(p, &rose->source_addr, ROSE_ADDR_LEN);
 496         p   += ROSE_ADDR_LEN;
 497
 498         memcpy(p, callsign, strlen(callsign));
 499         p   += strlen(callsign);
 500
 501         len       = p - buffer;
 502         buffer[0] = len - 1;
 503
 504         return len;
 505 }
 506
 507 void rose_disconnect(struct sock *sk, int reason, int cause, int diagnostic)
 508 {
 509         struct rose_sock *rose = rose_sk(sk);
 510
 511         rose_stop_timer(sk);
 512         rose_stop_idletimer(sk);
 513
 514         rose_clear_queues(sk);
 515
 516         rose->lci   = 0;
 517         rose->state = ROSE_STATE_0;
 518
 519         if (cause != -1)
 520                 rose->cause = cause;
 521
 522         if (diagnostic != -1)
 523                 rose->diagnostic = diagnostic;
 524
 525         sk->sk_state     = TCP_CLOSE;
 526         sk->sk_err       = reason;
 527         sk->sk_shutdown |= SEND_SHUTDOWN;
 528
 529         if (!sock_flag(sk, SOCK_DEAD)) {
 530                 sk->sk_state_change(sk);
 531                 sock_set_flag(sk, SOCK_DEAD);
 532         }
 533 }