linux-old/net/rose/rose_subr.c
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   1/*
   2 *      ROSE release 003
   3 *
   4 *      This code REQUIRES 2.1.15 or higher/ NET3.038
   5 *
   6 *      This module:
   7 *              This module is free software; you can redistribute it and/or
   8 *              modify it under the terms of the GNU General Public License
   9 *              as published by the Free Software Foundation; either version
  10 *              2 of the License, or (at your option) any later version.
  11 *
  12 *      History
  13 *      ROSE 001        Jonathan(G4KLX) Cloned from nr_subr.c
  14 *      ROSE 002        Jonathan(G4KLX) Centralised disconnect processing.
  15 *      ROSE 003        Jonathan(G4KLX) Added use count to neighbours.
  16 */
  17
  18#include <linux/errno.h>
  19#include <linux/types.h>
  20#include <linux/socket.h>
  21#include <linux/in.h>
  22#include <linux/kernel.h>
  23#include <linux/sched.h>
  24#include <linux/timer.h>
  25#include <linux/string.h>
  26#include <linux/sockios.h>
  27#include <linux/net.h>
  28#include <net/ax25.h>
  29#include <linux/inet.h>
  30#include <linux/netdevice.h>
  31#include <linux/skbuff.h>
  32#include <net/sock.h>
  33#include <asm/segment.h>
  34#include <asm/system.h>
  35#include <linux/fcntl.h>
  36#include <linux/mm.h>
  37#include <linux/interrupt.h>
  38#include <net/rose.h>
  39
  40/*
  41 *      This routine purges all of the queues of frames.
  42 */
  43void rose_clear_queues(struct sock *sk)
  44{
  45        skb_queue_purge(&sk->write_queue);
  46        skb_queue_purge(&sk->protinfo.rose->ack_queue);
  47}
  48
  49/*
  50 * This routine purges the input queue of those frames that have been
  51 * acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the
  52 * SDL diagram.
  53 */
  54void rose_frames_acked(struct sock *sk, unsigned short nr)
  55{
  56        struct sk_buff *skb;
  57
  58        /*
  59         * Remove all the ack-ed frames from the ack queue.
  60         */
  61        if (sk->protinfo.rose->va != nr) {
  62                while (skb_peek(&sk->protinfo.rose->ack_queue) != NULL && sk->protinfo.rose->va != nr) {
  63                        skb = skb_dequeue(&sk->protinfo.rose->ack_queue);
  64                        kfree_skb(skb);
  65                        sk->protinfo.rose->va = (sk->protinfo.rose->va + 1) % ROSE_MODULUS;
  66                }
  67        }
  68}
  69
  70void rose_requeue_frames(struct sock *sk)
  71{
  72        struct sk_buff *skb, *skb_prev = NULL;
  73
  74        /*
  75         * Requeue all the un-ack-ed frames on the output queue to be picked
  76         * up by rose_kick. This arrangement handles the possibility of an
  77         * empty output queue.
  78         */
  79        while ((skb = skb_dequeue(&sk->protinfo.rose->ack_queue)) != NULL) {
  80                if (skb_prev == NULL)
  81                        skb_queue_head(&sk->write_queue, skb);
  82                else
  83                        skb_append(skb_prev, skb);
  84                skb_prev = skb;
  85        }
  86}
  87
  88/*
  89 *      Validate that the value of nr is between va and vs. Return true or
  90 *      false for testing.
  91 */
  92int rose_validate_nr(struct sock *sk, unsigned short nr)
  93{
  94        unsigned short vc = sk->protinfo.rose->va;
  95
  96        while (vc != sk->protinfo.rose->vs) {
  97                if (nr == vc) return 1;
  98                vc = (vc + 1) % ROSE_MODULUS;
  99        }
 100
 101        if (nr == sk->protinfo.rose->vs) return 1;
 102
 103        return 0;
 104}
 105
 106/* 
 107 *  This routine is called when the packet layer internally generates a
 108 *  control frame.
 109 */
 110void rose_write_internal(struct sock *sk, int frametype)
 111{
 112        struct sk_buff *skb;
 113        unsigned char  *dptr;
 114        unsigned char  lci1, lci2;
 115        char buffer[100];
 116        int len, faclen = 0;
 117        int ax25_header_len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + 1;
 118
 119        len = ax25_header_len + ROSE_MIN_LEN;
 120        
 121        switch (frametype) {
 122                case ROSE_CALL_REQUEST:
 123                        len   += 1 + ROSE_ADDR_LEN + ROSE_ADDR_LEN;
 124                        faclen = rose_create_facilities(buffer, sk->protinfo.rose);
 125                        len   += faclen;
 126                        break;
 127                case ROSE_CALL_ACCEPTED:
 128                case ROSE_RESET_REQUEST:
 129                        len   += 2;
 130                        break;
 131                case ROSE_CLEAR_REQUEST:
 132                        len   += 3;
 133                        /* facilities */
 134                        faclen = 3 + 2 + AX25_ADDR_LEN + 3 + ROSE_ADDR_LEN;
 135                        dptr = buffer;
 136                        *dptr++ = faclen-1;     /* Facilities length */
 137                        *dptr++ = 0;
 138                        *dptr++ = FAC_NATIONAL;
 139                        *dptr++ = FAC_NATIONAL_FAIL_CALL;
 140                        *dptr++ = AX25_ADDR_LEN;
 141                        memcpy(dptr, &rose_callsign, AX25_ADDR_LEN);
 142                        dptr += AX25_ADDR_LEN;
 143                        *dptr++ = FAC_NATIONAL_FAIL_ADD;
 144                        *dptr++ = ROSE_ADDR_LEN + 1;
 145                        *dptr++ = ROSE_ADDR_LEN * 2;
 146                        memcpy(dptr, &sk->protinfo.rose->source_addr, ROSE_ADDR_LEN);
 147                        len   += faclen;
 148                        break;
 149        }
 150
 151        if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
 152                return;
 153
 154        /*
 155         *      Space for AX.25 header and PID.
 156         */
 157        skb_reserve(skb, ax25_header_len);
 158        
 159        dptr = skb_put(skb, len - ax25_header_len);
 160
 161        lci1 = (sk->protinfo.rose->lci >> 8) & 0x0F;
 162        lci2 = (sk->protinfo.rose->lci >> 0) & 0xFF;
 163
 164        switch (frametype) {
 165
 166                case ROSE_CALL_REQUEST:
 167                        *dptr++ = ROSE_GFI | lci1;
 168                        *dptr++ = lci2;
 169                        *dptr++ = frametype;
 170                        *dptr++ = 0xAA;
 171                        memcpy(dptr, &sk->protinfo.rose->dest_addr,  ROSE_ADDR_LEN);
 172                        dptr   += ROSE_ADDR_LEN;
 173                        memcpy(dptr, &sk->protinfo.rose->source_addr, ROSE_ADDR_LEN);
 174                        dptr   += ROSE_ADDR_LEN;
 175                        memcpy(dptr, buffer, faclen);
 176                        dptr   += faclen;
 177                        break;
 178
 179                case ROSE_CALL_ACCEPTED:
 180                        *dptr++ = ROSE_GFI | lci1;
 181                        *dptr++ = lci2;
 182                        *dptr++ = frametype;
 183                        *dptr++ = 0x00;         /* Address length */
 184                        *dptr++ = 0;            /* Facilities length */
 185                        break;
 186
 187                case ROSE_CLEAR_REQUEST:
 188                        *dptr++ = ROSE_GFI | lci1;
 189                        *dptr++ = lci2;
 190                        *dptr++ = frametype;
 191                        *dptr++ = sk->protinfo.rose->cause;
 192                        *dptr++ = sk->protinfo.rose->diagnostic;
 193                        *dptr++ = 0x00;         /* Address length */
 194                        memcpy(dptr, buffer, faclen);
 195                        dptr   += faclen;
 196                        break;
 197
 198                case ROSE_RESET_REQUEST:
 199                        *dptr++ = ROSE_GFI | lci1;
 200                        *dptr++ = lci2;
 201                        *dptr++ = frametype;
 202                        *dptr++ = ROSE_DTE_ORIGINATED;
 203                        *dptr++ = 0;
 204                        break;
 205
 206                case ROSE_RR:
 207                case ROSE_RNR:
 208                        *dptr++ = ROSE_GFI | lci1;
 209                        *dptr++ = lci2;
 210                        *dptr   = frametype;
 211                        *dptr++ |= (sk->protinfo.rose->vr << 5) & 0xE0;
 212                        break;
 213
 214                case ROSE_CLEAR_CONFIRMATION:
 215                case ROSE_RESET_CONFIRMATION:
 216                        *dptr++ = ROSE_GFI | lci1;
 217                        *dptr++ = lci2;
 218                        *dptr++  = frametype;
 219                        break;
 220
 221                default:
 222                        printk(KERN_ERR "ROSE: rose_write_internal - invalid frametype %02X\n", frametype);
 223                        kfree_skb(skb);
 224                        return;
 225        }
 226
 227        rose_transmit_link(skb, sk->protinfo.rose->neighbour);
 228}
 229
 230int rose_decode(struct sk_buff *skb, int *ns, int *nr, int *q, int *d, int *m)
 231{
 232        unsigned char *frame;
 233
 234        frame = skb->data;
 235
 236        *ns = *nr = *q = *d = *m = 0;
 237
 238        switch (frame[2]) {
 239                case ROSE_CALL_REQUEST:
 240                case ROSE_CALL_ACCEPTED:
 241                case ROSE_CLEAR_REQUEST:
 242                case ROSE_CLEAR_CONFIRMATION:
 243                case ROSE_RESET_REQUEST:
 244                case ROSE_RESET_CONFIRMATION:
 245                        return frame[2];
 246                default:
 247                        break;
 248        }
 249
 250        if ((frame[2] & 0x1F) == ROSE_RR  ||
 251            (frame[2] & 0x1F) == ROSE_RNR) {
 252                *nr = (frame[2] >> 5) & 0x07;
 253                return frame[2] & 0x1F;
 254        }
 255
 256        if ((frame[2] & 0x01) == ROSE_DATA) {
 257                *q  = (frame[0] & ROSE_Q_BIT) == ROSE_Q_BIT;
 258                *d  = (frame[0] & ROSE_D_BIT) == ROSE_D_BIT;
 259                *m  = (frame[2] & ROSE_M_BIT) == ROSE_M_BIT;
 260                *nr = (frame[2] >> 5) & 0x07;
 261                *ns = (frame[2] >> 1) & 0x07;
 262                return ROSE_DATA;
 263        }
 264
 265        return ROSE_ILLEGAL;
 266}
 267
 268static int rose_parse_national(unsigned char *p, struct rose_facilities_struct *facilities, int len)
 269{
 270        unsigned char *pt;
 271        unsigned char l, lg, n = 0;
 272        int fac_national_digis_received = 0;
 273
 274        do {
 275                switch (*p & 0xC0) {
 276                        case 0x00:
 277                                p   += 2;
 278                                n   += 2;
 279                                len -= 2;
 280                                break;
 281
 282                        case 0x40:
 283                                if (*p == FAC_NATIONAL_RAND)
 284                                        facilities->rand = ((p[1] << 8) & 0xFF00) + ((p[2] << 0) & 0x00FF);
 285                                p   += 3;
 286                                n   += 3;
 287                                len -= 3;
 288                                break;
 289
 290                        case 0x80:
 291                                p   += 4;
 292                                n   += 4;
 293                                len -= 4;
 294                                break;
 295
 296                        case 0xC0:
 297                                l = p[1];
 298                                if (*p == FAC_NATIONAL_DEST_DIGI) {
 299                                        if (!fac_national_digis_received) {
 300                                                memcpy(&facilities->source_digis[0], p + 2, AX25_ADDR_LEN);
 301                                                facilities->source_ndigis = 1;
 302                                        }
 303                                }
 304                                else if (*p == FAC_NATIONAL_SRC_DIGI) {
 305                                        if (!fac_national_digis_received) {
 306                                                memcpy(&facilities->dest_digis[0], p + 2, AX25_ADDR_LEN);
 307                                                facilities->dest_ndigis = 1;
 308                                        }
 309                                }
 310                                else if (*p == FAC_NATIONAL_FAIL_CALL) {
 311                                        memcpy(&facilities->fail_call, p + 2, AX25_ADDR_LEN);
 312                                }
 313                                else if (*p == FAC_NATIONAL_FAIL_ADD) {
 314                                        memcpy(&facilities->fail_addr, p + 3, ROSE_ADDR_LEN);
 315                                }
 316                                else if (*p == FAC_NATIONAL_DIGIS) {
 317                                        fac_national_digis_received = 1;
 318                                        facilities->source_ndigis = 0;
 319                                        facilities->dest_ndigis   = 0;
 320                                        for (pt = p + 2, lg = 0 ; lg < l ; pt += AX25_ADDR_LEN, lg += AX25_ADDR_LEN) {
 321                                                if (pt[6] & AX25_HBIT)
 322                                                        memcpy(&facilities->dest_digis[facilities->dest_ndigis++], pt, AX25_ADDR_LEN);
 323                                                else
 324                                                        memcpy(&facilities->source_digis[facilities->source_ndigis++], pt, AX25_ADDR_LEN);
 325                                        }
 326                                }
 327                                p   += l + 2;
 328                                n   += l + 2;
 329                                len -= l + 2;
 330                                break;
 331                }
 332        } while (*p != 0x00 && len > 0);
 333
 334        return n;
 335}
 336
 337static int rose_parse_ccitt(unsigned char *p, struct rose_facilities_struct *facilities, int len)
 338{
 339        unsigned char l, n = 0;
 340        char callsign[11];
 341
 342        do {
 343                switch (*p & 0xC0) {
 344                        case 0x00:
 345                                p   += 2;
 346                                n   += 2;
 347                                len -= 2;
 348                                break;
 349
 350                        case 0x40:
 351                                p   += 3;
 352                                n   += 3;
 353                                len -= 3;
 354                                break;
 355
 356                        case 0x80:
 357                                p   += 4;
 358                                n   += 4;
 359                                len -= 4;
 360                                break;
 361
 362                        case 0xC0:
 363                                l = p[1];
 364                                if (*p == FAC_CCITT_DEST_NSAP) {
 365                                        memcpy(&facilities->source_addr, p + 7, ROSE_ADDR_LEN);
 366                                        memcpy(callsign, p + 12,   l - 10);
 367                                        callsign[l - 10] = '\0';
 368                                        facilities->source_call = *asc2ax(callsign);
 369                                }
 370                                if (*p == FAC_CCITT_SRC_NSAP) {
 371                                        memcpy(&facilities->dest_addr, p + 7, ROSE_ADDR_LEN);
 372                                        memcpy(callsign, p + 12, l - 10);
 373                                        callsign[l - 10] = '\0';
 374                                        facilities->dest_call = *asc2ax(callsign);
 375                                }
 376                                p   += l + 2;
 377                                n   += l + 2;
 378                                len -= l + 2;
 379                                break;
 380                }
 381        } while (*p != 0x00 && len > 0);
 382
 383        return n;
 384}
 385
 386int rose_parse_facilities(unsigned char *p, struct rose_facilities_struct *facilities)
 387{
 388        int facilities_len, len;
 389
 390        facilities_len = *p++;
 391
 392        if (facilities_len == 0)
 393                return 0;
 394
 395        while (facilities_len > 0) {
 396                if (*p == 0x00) {
 397                        facilities_len--;
 398                        p++;
 399
 400                        switch (*p) {
 401                                case FAC_NATIONAL:              /* National */
 402                                        len = rose_parse_national(p + 1, facilities, facilities_len - 1);
 403                                        facilities_len -= len + 1;
 404                                        p += len + 1;
 405                                        break;
 406
 407                                case FAC_CCITT:         /* CCITT */
 408                                        len = rose_parse_ccitt(p + 1, facilities, facilities_len - 1);
 409                                        facilities_len -= len + 1;
 410                                        p += len + 1;
 411                                        break;
 412
 413                                default:
 414                                        printk(KERN_DEBUG "ROSE: rose_parse_facilities - unknown facilities family %02X\n", *p);
 415                                        facilities_len--;
 416                                        p++;
 417                                        break;
 418                        }
 419                }
 420                else break;     /* Error in facilities format */
 421        }
 422
 423        return 1;
 424}
 425
 426int rose_create_facilities(unsigned char *buffer, rose_cb *rose)
 427{
 428        unsigned char *p = buffer + 1;
 429        char *callsign;
 430        int len, nb;
 431
 432        /* National Facilities */
 433        if (rose->rand != 0 || rose->source_ndigis == 1 || rose->dest_ndigis == 1) {
 434                *p++ = 0x00;
 435                *p++ = FAC_NATIONAL;
 436
 437                if (rose->rand != 0) {
 438                        *p++ = FAC_NATIONAL_RAND;
 439                        *p++ = (rose->rand >> 8) & 0xFF;
 440                        *p++ = (rose->rand >> 0) & 0xFF;
 441                }
 442
 443                /* Sent before older facilities */
 444                if ((rose->source_ndigis > 0) || (rose->dest_ndigis > 0)) {
 445                        int maxdigi = 0;
 446                        *p++ = FAC_NATIONAL_DIGIS;
 447                        *p++ = AX25_ADDR_LEN * (rose->source_ndigis + rose->dest_ndigis);
 448                        for (nb = 0 ; nb < rose->source_ndigis ; nb++) {
 449                                if (++maxdigi >= ROSE_MAX_DIGIS)
 450                                        break;
 451                                memcpy(p, &rose->source_digis[nb], AX25_ADDR_LEN);
 452                                p[6] |= AX25_HBIT;
 453                                p += AX25_ADDR_LEN;
 454                        }
 455                        for (nb = 0 ; nb < rose->dest_ndigis ; nb++) {
 456                                if (++maxdigi >= ROSE_MAX_DIGIS)
 457                                        break;
 458                                memcpy(p, &rose->dest_digis[nb], AX25_ADDR_LEN);
 459                                p[6] &= ~AX25_HBIT;
 460                                p += AX25_ADDR_LEN;
 461                        }
 462                }
 463
 464                /* For compatibility */
 465                if (rose->source_ndigis > 0) {
 466                        *p++ = FAC_NATIONAL_SRC_DIGI;
 467                        *p++ = AX25_ADDR_LEN;
 468                        memcpy(p, &rose->source_digis[0], AX25_ADDR_LEN);
 469                        p   += AX25_ADDR_LEN;
 470                }
 471
 472                /* For compatibility */
 473                if (rose->dest_ndigis > 0) {
 474                        *p++ = FAC_NATIONAL_DEST_DIGI;
 475                        *p++ = AX25_ADDR_LEN;
 476                        memcpy(p, &rose->dest_digis[0], AX25_ADDR_LEN);
 477                        p   += AX25_ADDR_LEN;
 478                }
 479        }
 480
 481        *p++ = 0x00;
 482        *p++ = FAC_CCITT;
 483
 484        *p++ = FAC_CCITT_DEST_NSAP;
 485
 486        callsign = ax2asc(&rose->dest_call);
 487
 488        *p++ = strlen(callsign) + 10;
 489        *p++ = (strlen(callsign) + 9) * 2;              /* ??? */
 490
 491        *p++ = 0x47; *p++ = 0x00; *p++ = 0x11;
 492        *p++ = ROSE_ADDR_LEN * 2;
 493        memcpy(p, &rose->dest_addr, ROSE_ADDR_LEN);
 494        p   += ROSE_ADDR_LEN;
 495
 496        memcpy(p, callsign, strlen(callsign));
 497        p   += strlen(callsign);
 498
 499        *p++ = FAC_CCITT_SRC_NSAP;
 500
 501        callsign = ax2asc(&rose->source_call);
 502
 503        *p++ = strlen(callsign) + 10;
 504        *p++ = (strlen(callsign) + 9) * 2;              /* ??? */
 505
 506        *p++ = 0x47; *p++ = 0x00; *p++ = 0x11;
 507        *p++ = ROSE_ADDR_LEN * 2;
 508        memcpy(p, &rose->source_addr, ROSE_ADDR_LEN);
 509        p   += ROSE_ADDR_LEN;
 510
 511        memcpy(p, callsign, strlen(callsign));
 512        p   += strlen(callsign);
 513
 514        len       = p - buffer;
 515        buffer[0] = len - 1;
 516
 517        return len;
 518}
 519
 520void rose_disconnect(struct sock *sk, int reason, int cause, int diagnostic)
 521{
 522        rose_stop_timer(sk);
 523        rose_stop_idletimer(sk);
 524
 525        rose_clear_queues(sk);
 526
 527        sk->protinfo.rose->lci   = 0;
 528        sk->protinfo.rose->state = ROSE_STATE_0;
 529
 530        if (cause != -1)
 531                sk->protinfo.rose->cause = cause;
 532
 533        if (diagnostic != -1)
 534                sk->protinfo.rose->diagnostic = diagnostic;
 535
 536        sk->state     = TCP_CLOSE;
 537        sk->err       = reason;
 538        sk->shutdown |= SEND_SHUTDOWN;
 539
 540        if (!sk->dead)
 541                sk->state_change(sk);
 542
 543        sk->dead  = 1;
 544}
 545
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