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date and time created 82/07/31 21:28:05 by root
[unix-history] / usr / src / sys / deprecated / netdecnet / nsp_input.c
/* nsp_input.c 1.2 82/05/15 */
#include "../h/param.h"
#include "../h/systm.h"
#include "../h/mbuf.h"
#include "../h/protosw.h"
#include "../h/socket.h"
#include "../h/socketvar.h"
#include "../net/dn_systm.h"
#include "../net/nsp.h"
#include "../net/nsp_var.h"
#include "../errno.h"
int nspidebug = 1;
#define printd if(nspidebug)printf
/*
* NSP input routine: decode incoming packet and dispatch
* to appropriate socket. Called from the software interrupt
* at splnet.
*
* TODO:
* count occurances of various error conditions.
*/
nspintr()
{
struct mbuf *m;
struct tprh *t;
int s, bom, eom;
u_short srcnode;
char *p;
struct nspcb *np;
/*
* Loop pulling packets off the interrupt queue.
*/
next:
s = splimp();
IF_DEQUEUE(&nspintrq, m);
splx(s);
printd("nsp_input: m 0x%x", m);
if (m == 0)
return;
t = mtod(m, struct tprh *);
srcnode = t->tprh_srcnode;
m->m_len -= sizeof (struct tprh); /* use m_adj??? */
m->m_off += sizeof (struct tprh);
printd(", srcnode %d, len %d", srcnode, m->m_len);
if (m->m_len <= 0) {
m_freem(m);
goto next;
}
/*
* Switch on the type of the message.
*/
p = mtod(m, char *);
switch (*p) {
/*
* Got a Data message, possibly with EOM and
* BOM flags set. Call nsp_chkaddr to do ack
* and flow controll processing, then pass the
* data to the user.
*/
case NSP_DATA|NSP_EOM|NSP_BOM:
eom = bom = 1;
goto data;
case NSP_DATA|NSP_EOM:
eom = 1;
goto data;
case NSP_DATA|NSP_BOM:
bom = 1;
case NSP_DATA:
data:
printd(", DATA (%d,%d)", bom, eom);
np = nsp_chkaddr(m, srcnode, NSP_DATA, &segnum);
if (np == 0) {
m_freem(m);
goto next;
}
/*
* Data messages only valid in Run state
*/
if (np->n_state != NS_RUN) {
printf(", !RUN (%d)\n", np->n_state);
m_freem(m);
goto next;
}
if (SEQ_GTR(segnum, np->na_xmtdat)) {
/* SHOULD DO SEGMENT RECONSTRUCTION HERE */
printd(", got data!");
sbpappend(m, &np->n_socket->sb_rcv);
} else
np->n_flags |= NF_DATACK;
break;
/*
* Got an interrupt message. Call nsp_chkaddr
* (as usual). Save the interrupt data for the
* user.
* GENERATE A SIGNAL OF SOME SORT???
*/
case NSP_INTR:
printd(", INTR");
np = nsp_chkaddr(m, srcnode, NSP_INTR, &segnum);
if (np == 0) {
m_freem(m);
goto next;
}
/*
* If we are in the Connect Confirm state then
* this Interrupt packet causes the transition
* to the Run state. Otherwise we better be in
* the Run state already.
*/
if (np->n_state == NS_CC)
np->n_state = NS_RUN;
else if (np->n_state != NS_RUN) {
printf(", !RUN %d\n", np->n_state);
m_freem(m);
goto next;
}
/*
* If this segment is the one after the last
* other data segment we acked, and there is
* no waiting interrupt message, then queue
* this one up.
*/
if (segnum == SEQ_ADD(np->na_xmtoth, 1) &&
np->nf_locint == NFL_EMPTY) {
if (np->nb_rcv) {
printd(", flush old intr data");
m_freem(np->nb_rcv);
}
if (m->m_len > 16) {
printd(", intr data too long\n");
m_freem(m);
goto next;
}
np->nb_rcv = m;
np->nf_locint = NFL_INTR;
np->na_xmtoth = segnum; /* really += 1 */
np->n_flags |= NF_OTHACK;
} else if (SEQ_LEQ(segnum, np->na_xmtoth))
np->n_flags |= NF_OTHACK;
break;
/*
* Got a Link Service message. Process options
* to modify flow control values.
*/
case NSP_LS:
printd(", LS");
np = nsp_chkaddr(m, srcnode, NSP_LS, &segnum);
if (np == 0) {
m_freem(m);
goto next;
}
/*
* If we are in the Connect Confirm state then
* this Link Service packet causes the transition
* to the Run state. Otherwise we better be in
* the Run state already.
*/
if (np->n_state == NS_CC)
np->n_state = NS_RUN;
else if (np->n_state != NS_RUN) {
printd(", !RUN %d\n", np->n_state);
m_freem(m);
goto next;
}
p = mtod(m, char *);
lsf = *p++;
fcval = *p;
printd(", lsf 0x%x, fcval %d", lsf, fcval);
switch (lsf & NSPLS_FCVALINT) {
case NSPLS_DATREQ:
if (seqnum == SEQ_ADD(np->na_xmtoth, 1)) {
if (np->nf_remdat + fcval >= -128 &&
np->nf_remdat + fcval <= 127) {
np->nf_remdat += fcval;
np->na_xmtoth = segnum;
np->n_flags |= NF_OTHACK;
switch (lsf & NSPLS_FCMOD) {
case NSPLS_NOCHANGE:
break;
case NSPLS_ON:
np->n_flags &= ~NF_DATOFF;
break;
case NSPLS_OFF:
np->n_flags |= NF_DATOFF;
break;
default:
printd(", bad fcmod");
}
}
} else if (SEQ_LEQ(segnum, np->na_xmtoth))
np->n_flags |= NF_OTHACK;
break;
case NSPLS_INTREQ:
if (seqnum == SEQ_ADD(np->na_xmtoth, 1)) {
if (fcval >= 0 && np->nf_remint+fcval <= 127) {
np->nf_remint += fcval;
np->na_xmtoth = segnum;
np->n_flags |= NF_OTHACK;
} else if (SEQ_LEQ(segnum, np->na_xmtoth))
np->n_flags |= NF_OTHACK;
break;
default:
printd(", bad fcvalint");
}
break;
/*
* Got an acknowledgement for a Data message.
* Nsp_chkaddr processes the ack, nothing else
* to do.
*/
case NSP_DATACK:
printd(", DATACK");
np = nsp_chkaddr(m, srcnode, NSP_DATACK, &segnum);
if (np == 0) {
m_freem(m);
goto next;
}
break;
/*
* Got an acknowledgement for an Other Data message.
* Nsp_chkaddr processes the ack, nothing else to do.
*/
case NSP_OTHACK:
printd(", OTHACK");
np = nsp_chkaddr(m, srcnode, NSP_OTHACK, &segnum);
if (np == 0) {
m_freem(m);
goto next;
}
break;
/*
* Got a Connect Acknowledgement. Just verify
* the address and perform the state transition.
*/
case NSP_CONACK:
DOIT
break;
/*
* Got an unknown message, count it and flush it.
*/
default:
printd(", UNKNOWN!!!");
m_freem(m);
break;
}
printd("\n");
goto next;
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.