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++ = 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
 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                        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
 309static 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
 358int 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
 399static 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
 494void 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}
 521
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