bsd/netat/adsp_RxData.c

   1 /*
   2  * Copyright (c) 2006 Apple Computer, Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License.  The rights granted to you under the
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 /*
  31  * RxData.c
  32  *
  33  * From v01.28   Handle an incoming Data Packet       06/21/90 mbs
  34  */
  35 /*
  36  * Change log:
  37  *   06/29/95 - Modified to handle flow control for writing (Tuyen Nguyen)
  38  *    Modified for MP, 1996 by Tuyen Nguyen
  39  *   Modified, April 9, 1997 by Tuyen Nguyen for MacOSX.
  40  */
  41
  42 #include <sys/errno.h>
  43 #include <sys/types.h>
  44 #include <sys/param.h>
  45 #include <machine/spl.h>
  46 #include <sys/systm.h>
  47 #include <sys/kernel.h>
  48 #include <sys/proc.h>
  49 #include <sys/filedesc.h>
  50 #include <sys/fcntl.h>
  51 #include <sys/mbuf.h>
  52 #include <sys/socket.h>
  53 #include <sys/socketvar.h>
  54 #include <sys/time.h>
  55
  56 #include <netat/sysglue.h>
  57 #include <netat/appletalk.h>
  58 #include <netat/at_pcb.h>
  59 #include <netat/debug.h>
  60 #include <netat/adsp.h>
  61 #include <netat/adsp_internal.h>
  62
  63 gbuf_t *releaseData(mp, len)
  64     gbuf_t *mp;
  65     int len;
  66 {
  67     register gbuf_t *tmp;
  68     register int cnt;
  69     int freeit;
  70
  71     dPrintf(D_M_ADSP, D_L_TRACE,
  72             ("releaseData: mbuf=0x%x, len=%d\n", (unsigned)mp, len));
  73
  74     KERNEL_DEBUG(DBG_ADSP_RCV, 0, mp, len, 0, 0);
  75
  76     do {
  77         freeit = 1;             /* assume we use the whole mblk */
  78         if ((cnt = gbuf_len(mp)) > len) {
  79             freeit = 0;         /* using only part of the mblk */
  80             cnt = len;
  81         }
  82         gbuf_rinc(mp,cnt);
  83         len -= cnt;
  84         tmp = mp;
  85         mp = gbuf_cont(mp);
  86         if (freeit) {
  87             gbuf_freeb(tmp);
  88         } else
  89             return tmp;         /* if we don't use the whole block */
  90                                 /* pass back the partial gbuf_t pointer */
  91     } while (len && mp);
  92     return mp;
  93 }
  94
  95 /*
  96  * CheckRecvSeq
  97  *
  98  * We just got a non-attention packet.  Check the pktNextRecvSeq field
  99  * to see if it acknowledges any of our sent data.
 100  *
 101  * If any data was acked, check to see if we have anything to fill the
 102  * newly opened up remote receive window. Otherwise, if the ACK request
 103  * bit was set, we need to send an Ack Packet
 104  *
 105  * Always called as the result of receiving a packet.  Interrupts
 106  * are completely masked when this routine is called.
 107  *
 108  * INPUTS:
 109  *    sp stream
 110  *    f  pointer to ASDP header
 111  * OUTPUTS:
 112  *    none
 113  */
 114 void CheckRecvSeq(sp, f)        /* (CCBPtr sp, ADSP_FRAMEPtr f) */
 115     register CCBPtr sp;
 116     register ADSP_FRAMEPtr f;
 117 {
 118     int s;
 119     int pktNextRecvSeq;
 120     int sendWdwSeq;
 121     int eom;
 122     int hlen;
 123     register gbuf_t *mp;
 124
 125     ATDISABLE(s, sp->lock);
 126     if (f->descriptor & ADSP_ACK_REQ_BIT) { /* He wants an Ack */
 127         sp->sendDataAck = 1;
 128         sp->callSend = 1;
 129     }
 130
 131     pktNextRecvSeq = netdw(UAL_VALUE(f->pktNextRecvSeq)); /* Local copy */
 132
 133     /*
 134      * Make sure the sequence number corresponds to reality -- i.e. for
 135      * unacknowledged data that we have sent
 136      */
 137
 138     if (GT(pktNextRecvSeq, sp->maxSendSeq)) /* We've never sent this seq #! */
 139         goto noack;
 140
 141     if (GTE(pktNextRecvSeq, sp->timerSeq) && sp->waitingAck) {
 142         /* This acks our Ack Request */
 143         sp->waitingAck = 0;     /* Allow sending more */
 144         sp->pktSendCnt = 0;     /* Reset packet count */
 145         /* Remove retry timer */
 146         RemoveTimerElem(&adspGlobal.fastTimers, &sp->RetryTimer);
 147
 148         if (!sp->resentData) {  /* Data sent without retries */
 149             short diff;         /* Signed!! */
 150             /* All timings done in 6th second base */
 151             /* The contortions here are to prevent C from promoting
 152              * everything to longs and then using a library routine
 153              * to do the division. As 16-bit words, a DIVU instruction
 154              * is used.
 155              */
 156
 157             diff = (((word)(SysTicks() - sp->sendStamp)) / (word)10) -
 158                 sp->roundTrip + 1;
 159
 160             sp->roundTrip += diff >> 3; /* Update average */
 161
 162             if (diff < 0)       /* Take absolute value */
 163                 diff = -diff;
 164             sp->deviation += (diff - sp->deviation) >> 2; /* Update deviation*/
 165
 166             sp->rtmtInterval = sp->roundTrip +
 167                 ((short)2 * (short)sp->deviation);
 168
 169             if (!sp->noXmitFlow &&
 170                 sp->pktSendMax < 50) /* Bump # of sequential */
 171                 sp->pktSendMax++; /* Packets we'll send */
 172
 173             sp->noXmitFlow = 0;
 174         }
 175         else
 176             sp->resentData = 0;
 177
 178     }                           /* Acked our data */
 179
 180     if (LTE(pktNextRecvSeq,
 181             sp->firstRtmtSeq)) /* Was duplicate ack, so ignore */
 182         goto noack;
 183
 184     if (!sp->sData)             /* If nothing in send queue, ignore */
 185         goto noack;
 186
 187
 188     do {                        /* This acks bytes in our buffer */
 189         if (mp = sp->sbuf_mb) { /* Get ptr to oldest data header */
 190             sp->sbuf_mb = gbuf_next(mp); /* unlink it from send queue */
 191             eom = 1;
 192         } else {
 193             mp = sp->csbuf_mb;
 194             sp->csbuf_mb = 0;
 195             eom = 0;
 196         }
 197
 198         if (mp == 0) {          /* shouldn't happen! */
 199             sp->sData = 0;
 200             goto noack;
 201         }
 202         /*
 203          * Does this ack the entire data block we're now pointing at?
 204          */
 205         if (LTE((sp->firstRtmtSeq + eom + (hlen = gbuf_msgsize(mp))),
 206                  pktNextRecvSeq)) {
 207
 208             gbuf_freem(mp);
 209
 210             /* Update seq # of oldest byte in bfr */
 211             sp->firstRtmtSeq += eom + hlen;
 212
 213             if ((sp->sbuf_mb == 0) && (sp->csbuf_mb == 0)) {
 214                 /* If this was only block, then ... */
 215                 sp->sData = 0;  /* ... no data in queue */
 216                 sp->writeFlush = 0;
 217                 if (sp->state == sClosing) /* this may allow us to close... */
 218                     CheckOkToClose(sp);
 219                 atalk_enablew(sp->gref);
 220                 break;
 221             }
 222         }                       /* whole data block acked */
 223         else                    /* Only some of the data was acked */
 224         {
 225             short acked;
 226
 227             acked = (pktNextRecvSeq - sp->firstRtmtSeq);
 228             mp = releaseData(mp, acked);
 229             if (eom) {
 230                 if (mp) {
 231                         gbuf_next(mp) = sp->sbuf_mb;
 232                         sp->sbuf_mb = mp;
 233                 }
 234             } else
 235                 sp->csbuf_mb = mp;
 236
 237             sp->firstRtmtSeq = pktNextRecvSeq; /* Update seq # oldest byte */
 238             break;
 239         }
 240     } while (LT(sp->firstRtmtSeq, pktNextRecvSeq));
 241
 242     if (sp->sData)              /* We've got stuff to send */
 243         sp->callSend = 1;
 244
 245 noack:
 246     sendWdwSeq = netw(UAS_VALUE(f->pktRecvWdw)) - 1 + pktNextRecvSeq;
 247
 248     if (GT(sendWdwSeq, sp->sendWdwSeq)) /* Don't make send window smaller */
 249     {
 250         sp->callSend = 1;       /* His recv wdw opened, so see */
 251                                 /* if we can send more data */
 252         sp->sendWdwSeq  = sendWdwSeq;
 253     }
 254     ATENABLE(s, sp->lock);
 255 }
 256
 257 /*
 258  * RXData
 259  *
 260  * We just got a Data Packet
 261  * See if it came from anybody we know.
 262  *
 263  * Called from ADSP Packet with interrupts masked completely OFF
 264  *  *** In MacOSX interrupts do not seem to be off! ***
 265  *
 266  * INPUTS:
 267  *    Stream pointer
 268  *    gbuf_t pointer
 269  *    Pointer to ADSP header, (part of the mblk pointer to by mp)
 270  *    Length of header plus data
 271  * OUTPUTS:
 272  *    Returns 1 if packet was ignored
 273  */
 274 int RXData(sp, mp, f, len)      /* (CCBPtr sp, ADSP_FRAMEPtr f, word len) */
 275     CCBPtr sp;
 276     register gbuf_t *mp;
 277     ADSP_FRAMEPtr f;
 278     int len;
 279 {
 280     int s, offset;
 281     int PktFirstByteSeq;
 282     short cnt;
 283     char eom;
 284
 285     len -= ADSP_FRAME_LEN;
 286
 287     /* Does packet have eom bit set? */
 288     eom = (f->descriptor & ADSP_EOM_BIT) ? 1 : 0;
 289
 290     dPrintf(D_M_ADSP, D_L_TRACE,
 291             ("RXData: sp=0x%x, mbuf=0x%x, f=0x%x, len=%d, eom=%d\n",
 292              (unsigned)sp, (unsigned)mp, (unsigned)f, len, eom));
 293
 294     KERNEL_DEBUG(DBG_ADSP_RCV, 1, sp, mp, len, eom);
 295
 296     trace_mbufs(D_M_ADSP, "  mp", mp);
 297
 298     PktFirstByteSeq = netdw(UAL_VALUE(f->pktFirstByteSeq)); /* Local copy */
 299
 300     ATDISABLE(s, sp->lock);
 301     if (GT(PktFirstByteSeq, sp->recvSeq)) /* missed a packet (out of order) */
 302     {
 303         if (sp->badSeqCnt++ > sp->badSeqCnt) /* Need to send rexmit advice */
 304             sp->sendCtl |= B_CTL_RETRANSMIT;
 305         ATENABLE(s, sp->lock);
 306         CheckRecvSeq(sp, f);    /* Will set send ACK flag if requested */
 307         CheckReadQueue(sp);
 308         gbuf_freem(mp);
 309
 310         KERNEL_DEBUG(DBG_ADSP_RCV, 2, sp, 0, 0, 0);
 311         trace_mbufs(D_M_ADSP, "  exRXD m", sp->rbuf_mb);
 312         dPrintf(D_M_ADSP, D_L_TRACE, ("    End RXData - missed a packet\n"));
 313
 314         return 0;
 315     }
 316
 317     if (LTE(PktFirstByteSeq + len + eom, sp->recvSeq)) { /* duplicate data? */
 318         ATENABLE(s, sp->lock);
 319         CheckRecvSeq(sp, f);    /* Will set send ACK flag if requested */
 320         CheckReadQueue(sp);
 321         gbuf_freem(mp);
 322
 323         KERNEL_DEBUG(DBG_ADSP_RCV, 3, sp, 0, 0, 0);
 324         trace_mbufs(D_M_ADSP, "  exRXD m", sp->rbuf_mb);
 325         dPrintf(D_M_ADSP, D_L_TRACE, ("    End RXData - duplicate data\n"));
 326
 327         return 0;
 328     }
 329
 330     sp->badSeqCnt = 0;          /* reset out of sequence pckt counter */
 331
 332     cnt = sp->recvSeq - PktFirstByteSeq; /* # bytes we've seen already */
 333
 334     offset = ((unsigned char *)&f->data[cnt]) - (unsigned char *)gbuf_rptr(mp);
 335     gbuf_rinc(mp,offset);
 336                                 /* point recv mblk to data (past headers) */
 337
 338     len -= cnt;                 /* # of new data bytes */
 339
 340     cnt = len;                  /* # bytes left to deal with */
 341
 342     if (!sp->rData)             /* Recv bfr is empty */
 343     {
 344         sp->rData = 1;          /* Not empty any more */
 345
 346         if ((sp->rpb)->ioc == (caddr_t)mp) {
 347            dPrintf(D_M_ADSP, D_L_TRACE,
 348                    ("RXData: (pb->ioc == mp) no stored data\n"));
 349            KERNEL_DEBUG(DBG_ADSP_RCV, 4, sp, sp->rpb, 0, 0);
 350         }
 351         if (eom)
 352             sp->rbuf_mb = mp;
 353         else
 354             sp->crbuf_mb = mp;
 355     }                           /* Recv queue is empty */
 356
 357     /*
 358      * Else, there's already stored data.
 359      */
 360     else {
 361         gbuf_t *rmp;
 362         /*
 363          * Is this a new "message?"
 364          */
 365         if (eom) {
 366             if (sp->crbuf_mb) {
 367                 gbuf_linkb(sp->crbuf_mb, mp);
 368                 mp = sp->crbuf_mb;
 369                 sp->crbuf_mb = 0;
 370             }
 371             if (rmp = sp->rbuf_mb) {
 372                 /*
 373                  * Add it to the end
 374                  */
 375                 while(gbuf_next(rmp))
 376                     rmp = gbuf_next(rmp);
 377                 gbuf_next(rmp) = mp;
 378             } else
 379                 sp->rbuf_mb = mp;
 380         } else if (sp->crbuf_mb)
 381             gbuf_linkb(sp->crbuf_mb, mp);
 382         else
 383             sp->crbuf_mb = mp;
 384     }
 385     sp->recvSeq += (cnt + eom); /* We've got these bytes */
 386
 387     /* %%% We really should call check recv seq first, but let's
 388      * continue to do it down here.  We really want to service the
 389      * received packet first, and maybe reenable scc ints before
 390      * doing anything that might take a long while
 391      */
 392
 393     ATENABLE(s, sp->lock);
 394     CheckRecvSeq(sp, f);        /* Will set send ACK flag if requested */
 395     CheckReadQueue(sp);
 396     KERNEL_DEBUG(DBG_ADSP_RCV, 5, sp, sp->rbuf_mb, 0, 0);
 397     trace_mbufs(D_M_ADSP, "  eRXD m", sp->rbuf_mb);
 398     return 0;
 399 } /* RXData */