linux/net/rose/rose_subr.c
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   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
  31static int rose_create_facilities(unsigned char *buffer, struct rose_sock *rose);
  32
  33/*
  34 *      This routine purges all of the queues of frames.
  35 */
  36void 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 */
  47void 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
  64void 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 */
  86int 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 */
 103void 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
 202int 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
 240static 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
 334static 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
 396int 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
 436static 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
 531void 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}
 558