Source to bsd/netat/adsp_RxData.c
/*
* Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
*
* @APPLE_LICENSE_HEADER_START@
*
* The contents of this file constitute Original Code as defined in and
* are subject to the Apple Public Source License Version 1.1 (the
* "License"). You may not use this file except in compliance with the
* License. Please obtain a copy of the License at
* http://www.apple.com/publicsource and read it before using this file.
*
* This Original Code and all software distributed under the License are
* distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
* License for the specific language governing rights and limitations
* under the License.
*
* @APPLE_LICENSE_HEADER_END@
*/
/*
* RxData.c
*
* From v01.28 Handle an incoming Data Packet 06/21/90 mbs
*/
/*
* Change log:
* 06/29/95 - Modified to handle flow control for writing (Tuyen Nguyen)
* Modified for MP, 1996 by Tuyen Nguyen
* Modified, April 9, 1997 by Tuyen Nguyen for MacOSX.
*/
#include <sys/errno.h>
#include <sys/types.h>
#include <sys/param.h>
#include <machine/spl.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/filedesc.h>
#include <sys/fcntl.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/time.h>
#include <netat/sysglue.h>
#include <netat/appletalk.h>
#include <netat/at_pcb.h>
#include <netat/debug.h>
#include <netat/adsp.h>
#include <netat/adsp_internal.h>
gbuf_t *releaseData(mp, len)
gbuf_t *mp;
int len;
{
register gbuf_t *tmp;
register int cnt;
int freeit;
dPrintf(D_M_ADSP, D_L_TRACE,
("releaseData: mbuf=0x%x, len=%d\n", (unsigned)mp, len));
KERNEL_DEBUG(DBG_ADSP_RCV, 0, mp, len, 0, 0);
do {
freeit = 1; /* assume we use the whole mblk */
if ((cnt = gbuf_len(mp)) > len) {
freeit = 0; /* using only part of the mblk */
cnt = len;
}
gbuf_rinc(mp,cnt);
len -= cnt;
tmp = mp;
mp = gbuf_cont(mp);
if (freeit) {
gbuf_freeb(tmp);
} else
return tmp; /* if we don't use the whole block */
/* pass back the partial gbuf_t pointer */
} while (len && mp);
return mp;
}
/*
* CheckRecvSeq
*
* We just got a non-attention packet. Check the pktNextRecvSeq field
* to see if it acknowledges any of our sent data.
*
* If any data was acked, check to see if we have anything to fill the
* newly opened up remote receive window. Otherwise, if the ACK request
* bit was set, we need to send an Ack Packet
*
* Always called as the result of receiving a packet. Interrupts
* are completely masked when this routine is called.
*
* INPUTS:
* sp stream
* f pointer to ASDP header
* OUTPUTS:
* none
*/
void CheckRecvSeq(sp, f) /* (CCBPtr sp, ADSP_FRAMEPtr f) */
register CCBPtr sp;
register ADSP_FRAMEPtr f;
{
int s;
int pktNextRecvSeq;
int sendWdwSeq;
int eom;
int hlen;
register gbuf_t *mp;
ATDISABLE(s, sp->lock);
if (f->descriptor & ADSP_ACK_REQ_BIT) { /* He wants an Ack */
sp->sendDataAck = 1;
sp->callSend = 1;
}
pktNextRecvSeq = netdw(UAL_VALUE(f->pktNextRecvSeq)); /* Local copy */
/*
* Make sure the sequence number corresponds to reality -- i.e. for
* unacknowledged data that we have sent
*/
if (GT(pktNextRecvSeq, sp->maxSendSeq)) /* We've never sent this seq #! */
goto noack;
if (GTE(pktNextRecvSeq, sp->timerSeq) && sp->waitingAck) {
/* This acks our Ack Request */
sp->waitingAck = 0; /* Allow sending more */
sp->pktSendCnt = 0; /* Reset packet count */
/* Remove retry timer */
RemoveTimerElem(&adspGlobal.fastTimers, &sp->RetryTimer);
if (!sp->resentData) { /* Data sent without retries */
short diff; /* Signed!! */
/* All timings done in 6th second base */
/* The contortions here are to prevent C from promoting
* everything to longs and then using a library routine
* to do the division. As 16-bit words, a DIVU instruction
* is used.
*/
diff = (((word)(SysTicks() - sp->sendStamp)) / (word)10) -
sp->roundTrip + 1;
sp->roundTrip += diff >> 3; /* Update average */
if (diff < 0) /* Take absolute value */
diff = -diff;
sp->deviation += (diff - sp->deviation) >> 2; /* Update deviation*/
sp->rtmtInterval = sp->roundTrip +
((short)2 * (short)sp->deviation);
if (!sp->noXmitFlow &&
sp->pktSendMax < 50) /* Bump # of sequential */
sp->pktSendMax++; /* Packets we'll send */
sp->noXmitFlow = 0;
}
else
sp->resentData = 0;
} /* Acked our data */
if (LTE(pktNextRecvSeq,
sp->firstRtmtSeq)) /* Was duplicate ack, so ignore */
goto noack;
if (!sp->sData) /* If nothing in send queue, ignore */
goto noack;
do { /* This acks bytes in our buffer */
if (mp = sp->sbuf_mb) { /* Get ptr to oldest data header */
sp->sbuf_mb = gbuf_next(mp); /* unlink it from send queue */
eom = 1;
} else {
mp = sp->csbuf_mb;
sp->csbuf_mb = 0;
eom = 0;
}
if (mp == 0) { /* shouldn't happen! */
sp->sData = 0;
goto noack;
}
/*
* Does this ack the entire data block we're now pointing at?
*/
if (LTE((sp->firstRtmtSeq + eom + (hlen = gbuf_msgsize(mp))),
pktNextRecvSeq)) {
gbuf_freem(mp);
/* Update seq # of oldest byte in bfr */
sp->firstRtmtSeq += eom + hlen;
if ((sp->sbuf_mb == 0) && (sp->csbuf_mb == 0)) {
/* If this was only block, then ... */
sp->sData = 0; /* ... no data in queue */
sp->writeFlush = 0;
if (sp->state == sClosing) /* this may allow us to close... */
CheckOkToClose(sp);
atalk_enablew(sp->gref);
break;
}
} /* whole data block acked */
else /* Only some of the data was acked */
{
short acked;
acked = (pktNextRecvSeq - sp->firstRtmtSeq);
mp = releaseData(mp, acked);
if (eom) {
if (mp) {
gbuf_next(mp) = sp->sbuf_mb;
sp->sbuf_mb = mp;
}
} else
sp->csbuf_mb = mp;
sp->firstRtmtSeq = pktNextRecvSeq; /* Update seq # oldest byte */
break;
}
} while (LT(sp->firstRtmtSeq, pktNextRecvSeq));
if (sp->sData) /* We've got stuff to send */
sp->callSend = 1;
noack:
sendWdwSeq = netw(UAS_VALUE(f->pktRecvWdw)) - 1 + pktNextRecvSeq;
if (GT(sendWdwSeq, sp->sendWdwSeq)) /* Don't make send window smaller */
{
sp->callSend = 1; /* His recv wdw opened, so see */
/* if we can send more data */
sp->sendWdwSeq = sendWdwSeq;
}
ATENABLE(s, sp->lock);
}
/*
* RXData
*
* We just got a Data Packet
* See if it came from anybody we know.
*
* Called from ADSP Packet with interrupts masked completely OFF
* *** In MacOSX interrupts do not seem to be off! ***
*
* INPUTS:
* Stream pointer
* gbuf_t pointer
* Pointer to ADSP header, (part of the mblk pointer to by mp)
* Length of header plus data
* OUTPUTS:
* Returns 1 if packet was ignored
*/
int RXData(sp, mp, f, len) /* (CCBPtr sp, ADSP_FRAMEPtr f, word len) */
CCBPtr sp;
register gbuf_t *mp;
ADSP_FRAMEPtr f;
int len;
{
int s, offset;
int PktFirstByteSeq;
short cnt;
char eom;
len -= ADSP_FRAME_LEN;
/* Does packet have eom bit set? */
eom = (f->descriptor & ADSP_EOM_BIT) ? 1 : 0;
dPrintf(D_M_ADSP, D_L_TRACE,
("RXData: sp=0x%x, mbuf=0x%x, f=0x%x, len=%d, eom=%d\n",
(unsigned)sp, (unsigned)mp, (unsigned)f, len, eom));
KERNEL_DEBUG(DBG_ADSP_RCV, 1, sp, mp, len, eom);
trace_mbufs(D_M_ADSP, " mp", mp);
PktFirstByteSeq = netdw(UAL_VALUE(f->pktFirstByteSeq)); /* Local copy */
ATDISABLE(s, sp->lock);
if (GT(PktFirstByteSeq, sp->recvSeq)) /* missed a packet (out of order) */
{
if (sp->badSeqCnt++ > sp->badSeqCnt) /* Need to send rexmit advice */
sp->sendCtl |= B_CTL_RETRANSMIT;
ATENABLE(s, sp->lock);
CheckRecvSeq(sp, f); /* Will set send ACK flag if requested */
CheckReadQueue(sp);
gbuf_freem(mp);
KERNEL_DEBUG(DBG_ADSP_RCV, 2, sp, 0, 0, 0);
trace_mbufs(D_M_ADSP, " exRXD m", sp->rbuf_mb);
dPrintf(D_M_ADSP, D_L_TRACE, (" End RXData - missed a packet\n"));
return 0;
}
if (LTE(PktFirstByteSeq + len + eom, sp->recvSeq)) { /* duplicate data? */
ATENABLE(s, sp->lock);
CheckRecvSeq(sp, f); /* Will set send ACK flag if requested */
CheckReadQueue(sp);
gbuf_freem(mp);
KERNEL_DEBUG(DBG_ADSP_RCV, 3, sp, 0, 0, 0);
trace_mbufs(D_M_ADSP, " exRXD m", sp->rbuf_mb);
dPrintf(D_M_ADSP, D_L_TRACE, (" End RXData - duplicate data\n"));
return 0;
}
sp->badSeqCnt = 0; /* reset out of sequence pckt counter */
cnt = sp->recvSeq - PktFirstByteSeq; /* # bytes we've seen already */
offset = ((unsigned char *)&f->data[cnt]) - (unsigned char *)gbuf_rptr(mp);
gbuf_rinc(mp,offset);
/* point recv mblk to data (past headers) */
len -= cnt; /* # of new data bytes */
cnt = len; /* # bytes left to deal with */
if (!sp->rData) /* Recv bfr is empty */
{
sp->rData = 1; /* Not empty any more */
if ((sp->rpb)->ioc == mp) {
dPrintf(D_M_ADSP, D_L_TRACE,
("RXData: (pb->ioc == mp) no stored data\n"));
KERNEL_DEBUG(DBG_ADSP_RCV, 4, sp, sp->rpb, 0, 0);
}
if (eom)
sp->rbuf_mb = mp;
else
sp->crbuf_mb = mp;
} /* Recv queue is empty */
/*
* Else, there's already stored data.
*/
else {
gbuf_t *rmp;
/*
* Is this a new "message?"
*/
if (eom) {
if (sp->crbuf_mb) {
gbuf_linkb(sp->crbuf_mb, mp);
mp = sp->crbuf_mb;
sp->crbuf_mb = 0;
}
if (rmp = sp->rbuf_mb) {
/*
* Add it to the end
*/
while(gbuf_next(rmp))
rmp = gbuf_next(rmp);
gbuf_next(rmp) = mp;
} else
sp->rbuf_mb = mp;
} else if (sp->crbuf_mb)
gbuf_linkb(sp->crbuf_mb, mp);
else
sp->crbuf_mb = mp;
}
sp->recvSeq += (cnt + eom); /* We've got these bytes */
/* %%% We really should call check recv seq first, but let's
* continue to do it down here. We really want to service the
* received packet first, and maybe reenable scc ints before
* doing anything that might take a long while
*/
ATENABLE(s, sp->lock);
CheckRecvSeq(sp, f); /* Will set send ACK flag if requested */
CheckReadQueue(sp);
KERNEL_DEBUG(DBG_ADSP_RCV, 5, sp, sp->rbuf_mb, 0, 0);
trace_mbufs(D_M_ADSP, " eRXD m", sp->rbuf_mb);
return 0;
} /* RXData */