sys/i4b/layer2/i4b_util.c

   1 /*-
   2  * Copyright (c) 1997, 2002 Hellmuth Michaelis. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  23  * SUCH DAMAGE.
  24  */
  25
  26 /*---------------------------------------------------------------------------
  27  *
  28  *      i4b_util.c - layer 2 utility routines
  29  *      -------------------------------------
  30  *      last edit-date: [Sat Mar  9 17:55:03 2002]
  31  *
  32  *---------------------------------------------------------------------------*/
  33
  34 #include <sys/cdefs.h>
  35 __FBSDID("$FreeBSD$");
  36
  37 #include <sys/param.h>
  38 #include <sys/systm.h>
  39 #include <sys/mbuf.h>
  40 #include <sys/socket.h>
  41 #include <net/if.h>
  42
  43 #include <i4b/include/i4b_debug.h>
  44
  45 #include <i4b/include/i4b_global.h>
  46 #include <i4b/include/i4b_l1l2.h>
  47 #include <i4b/include/i4b_mbuf.h>
  48
  49 #include <i4b/layer2/i4b_l2.h>
  50
  51 /*---------------------------------------------------------------------------*
  52  *      routine ESTABLISH DATA LINK (Q.921 03/93 page 83)
  53  *---------------------------------------------------------------------------*/
  54 void
  55 i4b_establish_data_link(l2_softc_t *l2sc)
  56 {
  57         i4b_l1_activate(l2sc);
  58
  59         i4b_clear_exception_conditions(l2sc);
  60
  61         l2sc->RC = 0;
  62
  63         i4b_tx_sabme(l2sc, P1);
  64
  65         i4b_T200_restart(l2sc);
  66
  67         i4b_T203_stop(l2sc);
  68 }
  69
  70 /*---------------------------------------------------------------------------*
  71  *      routine CLEAR EXCEPTION CONDITIONS (Q.921 03/93 page 83)
  72  *---------------------------------------------------------------------------*/
  73 void
  74 i4b_clear_exception_conditions(l2_softc_t *l2sc)
  75 {
  76         CRIT_VAR;
  77
  78         CRIT_BEG;
  79
  80 /*XXX -------------------------------------------------------------- */
  81 /*XXX is this really appropriate here or should it moved elsewhere ? */
  82
  83         i4b_Dcleanifq(&l2sc->i_queue);
  84
  85         if(l2sc->ua_num != UA_EMPTY)
  86         {
  87                 i4b_Dfreembuf(l2sc->ua_frame);
  88                 l2sc->ua_num = UA_EMPTY;
  89         }
  90 /*XXX -------------------------------------------------------------- */
  91
  92         l2sc->peer_busy = 0;
  93
  94         l2sc->rej_excpt = 0;
  95
  96         l2sc->own_busy = 0;
  97
  98         l2sc->ack_pend = 0;
  99
 100         CRIT_END;
 101 }
 102
 103 /*---------------------------------------------------------------------------*
 104  *      routine TRANSMIT ENQUIRE (Q.921 03/93 page 83)
 105  *---------------------------------------------------------------------------*/
 106 void
 107 i4b_transmit_enquire(l2_softc_t *l2sc)
 108 {
 109         if(l2sc->own_busy)
 110                 i4b_tx_rnr_command(l2sc, P1);
 111         else
 112                 i4b_tx_rr_command(l2sc, P1);
 113
 114         l2sc->ack_pend = 0;
 115
 116         i4b_T200_start(l2sc);
 117 }
 118
 119 /*---------------------------------------------------------------------------*
 120  *      routine NR ERROR RECOVERY (Q.921 03/93 page 83)
 121  *---------------------------------------------------------------------------*/
 122 void
 123 i4b_nr_error_recovery(l2_softc_t *l2sc)
 124 {
 125         i4b_mdl_error_ind(l2sc, "i4b_nr_error_recovery", MDL_ERR_J);
 126
 127         i4b_establish_data_link(l2sc);
 128
 129         l2sc->l3initiated = 0;
 130 }
 131
 132 /*---------------------------------------------------------------------------*
 133  *      routine ENQUIRY RESPONSE (Q.921 03/93 page 84)
 134  *---------------------------------------------------------------------------*/
 135 void
 136 i4b_enquiry_response(l2_softc_t *l2sc)
 137 {
 138         if(l2sc->own_busy)
 139                 i4b_tx_rnr_response(l2sc, F1);
 140         else
 141                 i4b_tx_rr_response(l2sc, F1);
 142
 143         l2sc->ack_pend = 0;
 144 }
 145
 146 /*---------------------------------------------------------------------------*
 147  *      routine INVOKE RETRANSMISSION (Q.921 03/93 page 84)
 148  *---------------------------------------------------------------------------*/
 149 void
 150 i4b_invoke_retransmission(l2_softc_t *l2sc, int nr)
 151 {
 152         CRIT_VAR;
 153
 154         CRIT_BEG;
 155
 156         NDBGL2(L2_ERROR, "nr = %d", nr );
 157
 158         while(l2sc->vs != nr)
 159         {
 160                 NDBGL2(L2_ERROR, "nr(%d) != vs(%d)", nr, l2sc->vs);
 161
 162                 M128DEC(l2sc->vs);
 163
 164 /* XXXXXXXXXXXXXXXXX */
 165
 166                 if((l2sc->ua_num != UA_EMPTY) && (l2sc->vs == l2sc->ua_num))
 167                 {
 168                         if(_IF_QFULL(&l2sc->i_queue))
 169                         {
 170                                 NDBGL2(L2_ERROR, "ERROR, I-queue full!");
 171                         }
 172                         else
 173                         {
 174                                 IF_ENQUEUE(&l2sc->i_queue, l2sc->ua_frame);
 175                                 l2sc->ua_num = UA_EMPTY;
 176                         }
 177                 }
 178                 else
 179                 {
 180                         NDBGL2(L2_ERROR, "ERROR, l2sc->vs = %d, l2sc->ua_num = %d ",l2sc->vs, l2sc->ua_num);
 181                 }
 182
 183 /* XXXXXXXXXXXXXXXXX */
 184
 185                 i4b_i_frame_queued_up(l2sc);
 186         }
 187
 188         CRIT_END;
 189 }
 190
 191 /*---------------------------------------------------------------------------*
 192  *      routine ACKNOWLEDGE PENDING (Q.921 03/93 p 70)
 193  *---------------------------------------------------------------------------*/
 194 void
 195 i4b_acknowledge_pending(l2_softc_t *l2sc)
 196 {
 197         if(l2sc->ack_pend)
 198         {
 199                 l2sc->ack_pend = 0;
 200                 i4b_tx_rr_response(l2sc, F0);
 201         }
 202 }
 203
 204 /*---------------------------------------------------------------------------*
 205  *      i4b_print_frame - just print the hex contents of a frame
 206  *---------------------------------------------------------------------------*/
 207 void
 208 i4b_print_frame(int len, u_char *buf)
 209 {
 210 #if DO_I4B_DEBUG
 211         int i;
 212
 213         if (!(i4b_l2_debug & L2_ERROR))         /* XXXXXXXXXXXXXXXXXXXXX */
 214                 return;
 215
 216         for(i = 0; i < len; i++)
 217                 printf(" 0x%x", buf[i]);
 218         printf("\n");
 219 #endif
 220 }
 221
 222 /*---------------------------------------------------------------------------*
 223  *      i4b_print_l2var - print some l2softc vars
 224  *---------------------------------------------------------------------------*/
 225 void
 226 i4b_print_l2var(l2_softc_t *l2sc)
 227 {
 228         NDBGL2(L2_ERROR, "unit%d V(R)=%d, V(S)=%d, V(A)=%d,ACKP=%d,PBSY=%d,OBSY=%d",
 229                 l2sc->unit,
 230                 l2sc->vr,
 231                 l2sc->vs,
 232                 l2sc->va,
 233                 l2sc->ack_pend,
 234                 l2sc->peer_busy,
 235                 l2sc->own_busy);
 236 }
 237
 238 /*---------------------------------------------------------------------------*
 239  *      got s or i frame, check if valid ack for last sent frame
 240  *---------------------------------------------------------------------------*/
 241 void
 242 i4b_rxd_ack(l2_softc_t *l2sc, int nr)
 243 {
 244
 245 #ifdef NOTDEF
 246         NDBGL2(L2_ERROR, "N(R)=%d, UA=%d, V(R)=%d, V(S)=%d, V(A)=%d",
 247                 nr,
 248                 l2sc->ua_num,
 249                 l2sc->vr,
 250                 l2sc->vs,
 251                 l2sc->va);
 252 #endif
 253
 254         if(l2sc->ua_num != UA_EMPTY)
 255         {
 256                 CRIT_VAR;
 257
 258                 CRIT_BEG;
 259
 260                 M128DEC(nr);
 261
 262                 if(l2sc->ua_num != nr)
 263                         NDBGL2(L2_ERROR, "((N(R)-1)=%d) != (UA=%d) !!!", nr, l2sc->ua_num);
 264
 265                 i4b_Dfreembuf(l2sc->ua_frame);
 266                 l2sc->ua_num = UA_EMPTY;
 267
 268                 CRIT_END;
 269         }
 270 }
 271
 272 /*---------------------------------------------------------------------------*
 273  *      if not already active, activate layer 1
 274  *---------------------------------------------------------------------------*/
 275 void
 276 i4b_l1_activate(l2_softc_t *l2sc)
 277 {
 278         if(l2sc->ph_active == PH_INACTIVE)
 279         {
 280                 l2sc->ph_active = PH_ACTIVEPEND;
 281                 PH_Act_Req(l2sc->unit);
 282         }
 283 };
 284
 285 /*---------------------------------------------------------------------------*
 286  *      check for v(a) <= n(r) <= v(s)
 287  *      nr = receive sequence frame counter, va = acknowledge sequence frame
 288  *      counter and vs = transmit sequence frame counter
 289  *---------------------------------------------------------------------------*/
 290 int
 291 i4b_l2_nr_ok(int nr, int va, int vs)
 292 {
 293         if((va > nr) && ((nr != 0) || (va != 127)))
 294         {
 295                 NDBGL2(L2_ERROR, "ERROR, va = %d, nr = %d, vs = %d [1]", va, nr, vs);
 296                 return 0;       /* fail */
 297         }
 298
 299         if((nr > vs) && ((vs != 0) || (nr != 127)))
 300         {
 301                 NDBGL2(L2_ERROR, "ERROR, va = %d, nr = %d, vs = %d [2]", va, nr, vs);
 302                 return 0;       /* fail */
 303         }
 304         return 1;               /* good */
 305 }