bsd/netat/adsp_RxData.c

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