bsd/netat/adsp_RxData.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * RxData.c
  24  *
  25  * From v01.28   Handle an incoming Data Packet       06/21/90 mbs
  26  */
  27 /*
  28  * Change log:
  29  *   06/29/95 - Modified to handle flow control for writing (Tuyen Nguyen)
  30  *    Modified for MP, 1996 by Tuyen Nguyen
  31  *   Modified, April 9, 1997 by Tuyen Nguyen for MacOSX.
  32  */
  33
  34 #include <sys/errno.h>
  35 #include <sys/types.h>
  36 #include <sys/param.h>
  37 #include <machine/spl.h>
  38 #include <sys/systm.h>
  39 #include <sys/kernel.h>
  40 #include <sys/proc.h>
  41 #include <sys/filedesc.h>
  42 #include <sys/fcntl.h>
  43 #include <sys/mbuf.h>
  44 #include <sys/socket.h>
  45 #include <sys/socketvar.h>
  46 #include <sys/time.h>
  47
  48 #include <netat/sysglue.h>
  49 #include <netat/appletalk.h>
  50 #include <netat/at_pcb.h>
  51 #include <netat/debug.h>
  52 #include <netat/adsp.h>
  53 #include <netat/adsp_internal.h>
  54
  55 gbuf_t *releaseData(mp, len)
  56     gbuf_t *mp;
  57     int len;
  58 {
  59     register gbuf_t *tmp;
  60     register int cnt;
  61     int freeit;
  62
  63     dPrintf(D_M_ADSP, D_L_TRACE,
  64             ("releaseData: mbuf=0x%x, len=%d\n", (unsigned)mp, len));
  65
  66     KERNEL_DEBUG(DBG_ADSP_RCV, 0, mp, len, 0, 0);
  67
  68     do {
  69         freeit = 1;             /* assume we use the whole mblk */
  70         if ((cnt = gbuf_len(mp)) > len) {
  71             freeit = 0;         /* using only part of the mblk */
  72             cnt = len;
  73         }
  74         gbuf_rinc(mp,cnt);
  75         len -= cnt;
  76         tmp = mp;
  77         mp = gbuf_cont(mp);
  78         if (freeit) {
  79             gbuf_freeb(tmp);
  80         } else
  81             return tmp;         /* if we don't use the whole block */
  82                                 /* pass back the partial gbuf_t pointer */
  83     } while (len && mp);
  84     return mp;
  85 }
  86
  87 /*
  88  * CheckRecvSeq
  89  *
  90  * We just got a non-attention packet.  Check the pktNextRecvSeq field
  91  * to see if it acknowledges any of our sent data.
  92  *
  93  * If any data was acked, check to see if we have anything to fill the
  94  * newly opened up remote receive window. Otherwise, if the ACK request
  95  * bit was set, we need to send an Ack Packet
  96  *
  97  * Always called as the result of receiving a packet.  Interrupts
  98  * are completely masked when this routine is called.
  99  *
 100  * INPUTS:
 101  *    sp stream
 102  *    f  pointer to ASDP header
 103  * OUTPUTS:
 104  *    none
 105  */
 106 void CheckRecvSeq(sp, f)        /* (CCBPtr sp, ADSP_FRAMEPtr f) */
 107     register CCBPtr sp;
 108     register ADSP_FRAMEPtr f;
 109 {
 110     int s;
 111     int pktNextRecvSeq;
 112     int sendWdwSeq;
 113     int eom;
 114     int hlen;
 115     register gbuf_t *mp;
 116
 117     ATDISABLE(s, sp->lock);
 118     if (f->descriptor & ADSP_ACK_REQ_BIT) { /* He wants an Ack */
 119         sp->sendDataAck = 1;
 120         sp->callSend = 1;
 121     }
 122
 123     pktNextRecvSeq = netdw(UAL_VALUE(f->pktNextRecvSeq)); /* Local copy */
 124
 125     /*
 126      * Make sure the sequence number corresponds to reality -- i.e. for
 127      * unacknowledged data that we have sent
 128      */
 129
 130     if (GT(pktNextRecvSeq, sp->maxSendSeq)) /* We've never sent this seq #! */
 131         goto noack;
 132
 133     if (GTE(pktNextRecvSeq, sp->timerSeq) && sp->waitingAck) {
 134         /* This acks our Ack Request */
 135         sp->waitingAck = 0;     /* Allow sending more */
 136         sp->pktSendCnt = 0;     /* Reset packet count */
 137         /* Remove retry timer */
 138         RemoveTimerElem(&adspGlobal.fastTimers, &sp->RetryTimer);
 139
 140         if (!sp->resentData) {  /* Data sent without retries */
 141             short diff;         /* Signed!! */
 142             /* All timings done in 6th second base */
 143             /* The contortions here are to prevent C from promoting
 144              * everything to longs and then using a library routine
 145              * to do the division. As 16-bit words, a DIVU instruction
 146              * is used.
 147              */
 148
 149             diff = (((word)(SysTicks() - sp->sendStamp)) / (word)10) -
 150                 sp->roundTrip + 1;
 151
 152             sp->roundTrip += diff >> 3; /* Update average */
 153
 154             if (diff < 0)       /* Take absolute value */
 155                 diff = -diff;
 156             sp->deviation += (diff - sp->deviation) >> 2; /* Update deviation*/
 157
 158             sp->rtmtInterval = sp->roundTrip +
 159                 ((short)2 * (short)sp->deviation);
 160
 161             if (!sp->noXmitFlow &&
 162                 sp->pktSendMax < 50) /* Bump # of sequential */
 163                 sp->pktSendMax++; /* Packets we'll send */
 164
 165             sp->noXmitFlow = 0;
 166         }
 167         else
 168             sp->resentData = 0;
 169
 170     }                           /* Acked our data */
 171
 172     if (LTE(pktNextRecvSeq,
 173             sp->firstRtmtSeq)) /* Was duplicate ack, so ignore */
 174         goto noack;
 175
 176     if (!sp->sData)             /* If nothing in send queue, ignore */
 177         goto noack;
 178
 179
 180     do {                        /* This acks bytes in our buffer */
 181         if (mp = sp->sbuf_mb) { /* Get ptr to oldest data header */
 182             sp->sbuf_mb = gbuf_next(mp); /* unlink it from send queue */
 183             eom = 1;
 184         } else {
 185             mp = sp->csbuf_mb;
 186             sp->csbuf_mb = 0;
 187             eom = 0;
 188         }
 189
 190         if (mp == 0) {          /* shouldn't happen! */
 191             sp->sData = 0;
 192             goto noack;
 193         }
 194         /*
 195          * Does this ack the entire data block we're now pointing at?
 196          */
 197         if (LTE((sp->firstRtmtSeq + eom + (hlen = gbuf_msgsize(mp))),
 198                  pktNextRecvSeq)) {
 199
 200             gbuf_freem(mp);
 201
 202             /* Update seq # of oldest byte in bfr */
 203             sp->firstRtmtSeq += eom + hlen;
 204
 205             if ((sp->sbuf_mb == 0) && (sp->csbuf_mb == 0)) {
 206                 /* If this was only block, then ... */
 207                 sp->sData = 0;  /* ... no data in queue */
 208                 sp->writeFlush = 0;
 209                 if (sp->state == sClosing) /* this may allow us to close... */
 210                     CheckOkToClose(sp);
 211                 atalk_enablew(sp->gref);
 212                 break;
 213             }
 214         }                       /* whole data block acked */
 215         else                    /* Only some of the data was acked */
 216         {
 217             short acked;
 218
 219             acked = (pktNextRecvSeq - sp->firstRtmtSeq);
 220             mp = releaseData(mp, acked);
 221             if (eom) {
 222                 if (mp) {
 223                         gbuf_next(mp) = sp->sbuf_mb;
 224                         sp->sbuf_mb = mp;
 225                 }
 226             } else
 227                 sp->csbuf_mb = mp;
 228
 229             sp->firstRtmtSeq = pktNextRecvSeq; /* Update seq # oldest byte */
 230             break;
 231         }
 232     } while (LT(sp->firstRtmtSeq, pktNextRecvSeq));
 233
 234     if (sp->sData)              /* We've got stuff to send */
 235         sp->callSend = 1;
 236
 237 noack:
 238     sendWdwSeq = netw(UAS_VALUE(f->pktRecvWdw)) - 1 + pktNextRecvSeq;
 239
 240     if (GT(sendWdwSeq, sp->sendWdwSeq)) /* Don't make send window smaller */
 241     {
 242         sp->callSend = 1;       /* His recv wdw opened, so see */
 243                                 /* if we can send more data */
 244         sp->sendWdwSeq  = sendWdwSeq;
 245     }
 246     ATENABLE(s, sp->lock);
 247 }
 248
 249 /*
 250  * RXData
 251  *
 252  * We just got a Data Packet
 253  * See if it came from anybody we know.
 254  *
 255  * Called from ADSP Packet with interrupts masked completely OFF
 256  *  *** In MacOSX interrupts do not seem to be off! ***
 257  *
 258  * INPUTS:
 259  *    Stream pointer
 260  *    gbuf_t pointer
 261  *    Pointer to ADSP header, (part of the mblk pointer to by mp)
 262  *    Length of header plus data
 263  * OUTPUTS:
 264  *    Returns 1 if packet was ignored
 265  */
 266 int RXData(sp, mp, f, len)      /* (CCBPtr sp, ADSP_FRAMEPtr f, word len) */
 267     CCBPtr sp;
 268     register gbuf_t *mp;
 269     ADSP_FRAMEPtr f;
 270     int len;
 271 {
 272     int s, offset;
 273     int PktFirstByteSeq;
 274     short cnt;
 275     char eom;
 276
 277     len -= ADSP_FRAME_LEN;
 278
 279     /* Does packet have eom bit set? */
 280     eom = (f->descriptor & ADSP_EOM_BIT) ? 1 : 0;
 281
 282     dPrintf(D_M_ADSP, D_L_TRACE,
 283             ("RXData: sp=0x%x, mbuf=0x%x, f=0x%x, len=%d, eom=%d\n",
 284              (unsigned)sp, (unsigned)mp, (unsigned)f, len, eom));
 285
 286     KERNEL_DEBUG(DBG_ADSP_RCV, 1, sp, mp, len, eom);
 287
 288     trace_mbufs(D_M_ADSP, "  mp", mp);
 289
 290     PktFirstByteSeq = netdw(UAL_VALUE(f->pktFirstByteSeq)); /* Local copy */
 291
 292     ATDISABLE(s, sp->lock);
 293     if (GT(PktFirstByteSeq, sp->recvSeq)) /* missed a packet (out of order) */
 294     {
 295         if (sp->badSeqCnt++ > sp->badSeqCnt) /* Need to send rexmit advice */
 296             sp->sendCtl |= B_CTL_RETRANSMIT;
 297         ATENABLE(s, sp->lock);
 298         CheckRecvSeq(sp, f);    /* Will set send ACK flag if requested */
 299         CheckReadQueue(sp);
 300         gbuf_freem(mp);
 301
 302         KERNEL_DEBUG(DBG_ADSP_RCV, 2, sp, 0, 0, 0);
 303         trace_mbufs(D_M_ADSP, "  exRXD m", sp->rbuf_mb);
 304         dPrintf(D_M_ADSP, D_L_TRACE, ("    End RXData - missed a packet\n"));
 305
 306         return 0;
 307     }
 308
 309     if (LTE(PktFirstByteSeq + len + eom, sp->recvSeq)) { /* duplicate data? */
 310         ATENABLE(s, sp->lock);
 311         CheckRecvSeq(sp, f);    /* Will set send ACK flag if requested */
 312         CheckReadQueue(sp);
 313         gbuf_freem(mp);
 314
 315         KERNEL_DEBUG(DBG_ADSP_RCV, 3, sp, 0, 0, 0);
 316         trace_mbufs(D_M_ADSP, "  exRXD m", sp->rbuf_mb);
 317         dPrintf(D_M_ADSP, D_L_TRACE, ("    End RXData - duplicate data\n"));
 318
 319         return 0;
 320     }
 321
 322     sp->badSeqCnt = 0;          /* reset out of sequence pckt counter */
 323
 324     cnt = sp->recvSeq - PktFirstByteSeq; /* # bytes we've seen already */
 325
 326     offset = ((unsigned char *)&f->data[cnt]) - (unsigned char *)gbuf_rptr(mp);
 327     gbuf_rinc(mp,offset);
 328                                 /* point recv mblk to data (past headers) */
 329
 330     len -= cnt;                 /* # of new data bytes */
 331
 332     cnt = len;                  /* # bytes left to deal with */
 333
 334     if (!sp->rData)             /* Recv bfr is empty */
 335     {
 336         sp->rData = 1;          /* Not empty any more */
 337
 338         if ((sp->rpb)->ioc == mp) {
 339            dPrintf(D_M_ADSP, D_L_TRACE,
 340                    ("RXData: (pb->ioc == mp) no stored data\n"));
 341            KERNEL_DEBUG(DBG_ADSP_RCV, 4, sp, sp->rpb, 0, 0);
 342         }
 343         if (eom)
 344             sp->rbuf_mb = mp;
 345         else
 346             sp->crbuf_mb = mp;
 347     }                           /* Recv queue is empty */
 348
 349     /*
 350      * Else, there's already stored data.
 351      */
 352     else {
 353         gbuf_t *rmp;
 354         /*
 355          * Is this a new "message?"
 356          */
 357         if (eom) {
 358             if (sp->crbuf_mb) {
 359                 gbuf_linkb(sp->crbuf_mb, mp);
 360                 mp = sp->crbuf_mb;
 361                 sp->crbuf_mb = 0;
 362             }
 363             if (rmp = sp->rbuf_mb) {
 364                 /*
 365                  * Add it to the end
 366                  */
 367                 while(gbuf_next(rmp))
 368                     rmp = gbuf_next(rmp);
 369                 gbuf_next(rmp) = mp;
 370             } else
 371                 sp->rbuf_mb = mp;
 372         } else if (sp->crbuf_mb)
 373             gbuf_linkb(sp->crbuf_mb, mp);
 374         else
 375             sp->crbuf_mb = mp;
 376     }
 377     sp->recvSeq += (cnt + eom); /* We've got these bytes */
 378
 379     /* %%% We really should call check recv seq first, but let's
 380      * continue to do it down here.  We really want to service the
 381      * received packet first, and maybe reenable scc ints before
 382      * doing anything that might take a long while
 383      */
 384
 385     ATENABLE(s, sp->lock);
 386     CheckRecvSeq(sp, f);        /* Will set send ACK flag if requested */
 387     CheckReadQueue(sp);
 388     KERNEL_DEBUG(DBG_ADSP_RCV, 5, sp, sp->rbuf_mb, 0, 0);
 389     trace_mbufs(D_M_ADSP, "  eRXD m", sp->rbuf_mb);
 390     return 0;
 391 } /* RXData */