SRI-NOSC/ncpk/dti/impi2.c
#
#include "../h/param.h"
#include "../h/user.h"
#include "../h/buf.h"
#include "../h/net.h"
#include "../h/netbuf.h"
#include "../h/imp.h"
#include "../h/file.h"
#include "../h/ncp.h"
#include "../h/contab.h"
#include "../h/proc.h"
#include "../h/src.h"
/*
defines for dealing with host to host protocol */
#define hhnop 0 /* nop */
#define hhall 4 /* allocate */
#define hhinr 7 /* interrupt by receiver */
#define hhins 8 /* interrupt by sender */
char hhsize[14];
char host_map[32];
/* name:
flushimp
function:
increment number of imp flushes and reload imp interface with
buffer to dump data into
algorithm:
set impflushing flag
handle statistics
reload imp interface with black hole
parameters:
none
returns:
nothing
globals:
impflushing=
imp_stat.i_flushes=
calls:
emerbuf to get address of black hole
impread to load imp interface with address of hole
called by:
imp_input
hh
history:
initial coding 1/7/75 by Steve Holmgren
*/
flushimp()
{ /* repeatedly called when we want imp interface cleaned out */
impflushing = 1;
imp_stat.i_flushes++;
impread( emerbuf(),net_b_size );
}
/* name:
ihbget
function:
To reload the imp interface with a buffer to store data into
algorithm:
If a buffer is available set impmsg to address
call impread to reload imp interface registers
else
couldnt get a buffer start flushing data
parameters:
none
returns:
nothing
globals:
impmsg=
calls:
appendb to add another buffer to impmsg
impread to load imp interface registers
flushimp to flush imp data if couldnt get buffer
called by:
imp_input
hh
history:
initial coding 1/7/75 by Steve Holmgren
*/
ihbget() /* stands for imp host buffer getter */
{
register struct netbuf *bp;
/* called when there is data to buffer from the imp */
/* appendb returns 0 if cant get buffer */
if( bp=appendb( impmsg ) )
{
impmsg = bp;
impread( bp->b_data,net_b_size );
}
else
{
printf("flush bfr\n");
flushimp();
}
}
/*
*/
struct salloc /* structure to lay over an allocate command */
{
char a_op;
char a_link;
int a_msgs;
int a_bitshi;
int a_bitslo;
};
/* name:
hh1
function:
To search through host to host protocol messages strip out any
that apply to the user ( allocates for now )
algorithm:
loops thru looking for hh commands in IMPMSG
it copies a command at a time to HHPROTO, process the
protocol if it is an allocate, inr, or ins. If it is
none of the above, it is stuck in an output message.
once all of the input has been messed with, if there is an
output message it is sent to the ncpdaemon with our blessing.
parameters:
none
returns:
nothing
globals:
impmsg
implen
hhsize[]
impncp
calls:
allocate to deal with allocate commands rcvd from net
to_ncp to send uninteresting protocol to ncpdaemon
ipc_trans to send ins or inr
psignal if old style i/o to send ins or inr
called by:
hh
history:
initial coding 1/7/75 by Steve Holmgren
modified to send events when ins or inr arrives 12/8/76 by David Healy
re-written (the pile before had mucho bugs) Feb 1977 S. F. Holmgren
*/
hh1()
{
register char hhcom;
register cnt;
register char *sktp;
static char *daemsg;
static char hhproto[96];
daemsg = 0;
while( implen > 0 ) /* while things in msg */
{
hhcom = (impmsg->b_qlink)->b_data[0] & 0377;
if( hhcom > NUMHHOPS )
{
daemsg = catmsg( daemsg,impmsg );
goto fordaemon;
}
cnt = hhsize[ hhcom ]; /* get bytes in this command */
implen =- cnt; /* decrement implen */
if( bytesout( &impmsg,&hhproto,cnt,1 )) /* msg not long enough */
{
printf("imp bad protocol msg\n");
implen = 0; /* force msg empty */
continue;
}
else
if( hhcom == hhall && (sktp=imphostlink( hhproto[1]|0200 )) )
{
allocate( sktp,&hhproto );
continue;
}
else
if( hhcom == hhins && (sktp=imphostlink( hhproto[1]&0177 )) )
{
if( &proc[sktp->r_pid]->p_stat ) /* there ? */
{
if( sktp->r_flags&n_nbio )
ipc_trans( SRC_INS | ( 1 << 8 ), sktp->r_pid,sktp->r_ufid,0 );
else
psignal( &proc[sktp->r_pid],SIGINR );
}
continue;
}
else
if( hhcom == hhinr && (sktp=imphostlink( hhproto[1]|0200 )) )
{
if( &proc[sktp->r_pid]->p_stat )
{
if( sktp->w_flags&n_nbio )
ipc_trans( SRC_INR | ( 1 << 8 ),sktp->w_pid,sktp->w_ufid,0 );
else
psignal( &proc[sktp->w_pid],SIGINR );
}
continue;
}
else
if( hhcom == hhnop )
continue;
vectomsg( &hhproto,cnt,&daemsg,1 ); /* got here then give it to daemon */
}
if( daemsg != 0 ) /* something in msg */
fordaemon:
to_ncp( impncp,5,daemsg ); /* send to daemon */
}
/* name:
allocate
function:
To look over host to host allocate protocol messages .
determine whether they are going to ncpdaemon or user
send off to ncpdaemon, inc appropriate user fields.
algorithm:
if host_link in conn tab
if socket flags say to ncpdaemon
send to ncpdaemon with imp to host leader
else
update num of messages alocated
update number of bits allocated
tell user allocate came in
let user run
parameters:
allocp pointer to a host host allocate
returns:
nothing
globals:
impncp
sktp->w_msgs=
sktp->w_falloc=
sktp->w_flags=
calls:
imphostlink to get pointer to socket inode from host link
vectomsg to build a msg from vec passed to send to ncp daemon
to_ncp to ship the allocate off to the ncp daemon
dpadd (sys) to add two double precision words
wakeup (sys) to let the user run
called by:
hh1
history:
initial coding 1/7/75 by Steve Holmgren
modified to implement nbio 12/8/76 by Dave Healy
*/
allocate( skt_ptr,allocp )
struct wrtskt *skt_ptr;
{
/* called from hh1 when a hh allocate is received */
register char *ap;
register struct wrtskt *sktp;
int nbytes; /* allocation */
struct netbuf *msgp;
sktp = skt_ptr;
ap = allocp;
msgp = 0;
if (sktp->w_flags & n_toncp)
{
vectomsg( allocp,8,&msgp,1 );
to_ncp( impncp,5,msgp );
}
else
{
sktp->w_msgs =+ swab( ap->a_msgs );
dpadd(sktp->w_falloc,swab(ap->a_bitslo));
sktp->w_falloc[0] =+ swab( ap->a_bitshi );
sktp->w_flags =| n_allocwt;
if ((sktp -> w_flags & n_waiting) == 0)
{
if( (sktp->w_flags&n_open) == 0 )
return;
if ((sktp -> w_flags & n_event) && ((nbytes = anyalloc (sktp)) != 0))
{
sktp -> w_flags =& ~n_event;
ipc_trans (SRC_WRITE | (1 << 8),
sktp -> w_pid, sktp -> w_ufid, nbytes);
}
else
wakeup( sktp );
}
}
}
/* name:
rmovepad
function:
To remove the padding attached to every host host protocol msg
and standard message by the imp
algorithm:
given a bytesize in number of bytes in that size, calculate
the number of 8 bit bytes.
set the message length to that size
run through the message a buffer at a time subtracting
the buffer length from the calculated size. eventually
it will go negative, since the number of bytes calculated
is less that the actual number of bytes in the msg
subtract the number of pad bytes from the last buffer in
the message to setthe number of actual number of data bytes
then free any remaining buffers.
set impmsg to the new last buffer.
parameters:
none
returns:
nothing
globals:
implen=
impmsg=
calls:
swab (sys) to switch top and bottom bytes
freebuf to release the last buffer from the message
called by:
hh
history:
initial coding 1/7/75 by Steve Holmgren
*/
int last_nbytes;
rmovepad()
{
/* calculates number of bytes from impleader then runs through impsg buffers
adding up counts until number calculated or end of msg is reached.
sets impcnt tothe min of amt in msg and calculated and discards
any excess bytes */
register struct netbuf *bfrp;
register cnt;
impmsg = bfrp = impmsg->b_qlink; /* point at first bfr */
implen = swab( imp.bcnt ); /* get num bytes */
cnt = imp.bsize * implen; /* calc number of bits */
cnt = ( cnt+7 ) / 8;
while( (cnt =- bfrp->b_len) > 0 )
{
if( bfrp->b_qlink == impmsg ) /* wrapped around? */
{
printf("imp msg wrap\n");
break;
}
bfrp = bfrp->b_qlink;
}
if( cnt < 0 )
bfrp->b_len = (bfrp->b_len & 0377) + cnt;
while( bfrp->b_qlink != impmsg )
freebuf( bfrp );
impmsg = bfrp;
if( cnt > 0 ) /* didnt eat them all? */
{
printf("IMP: missing %d data bytes\n",cnt);
return(1);
}
return(0);
}
/* name:
imphostlink
function:
Checks to see if the current host and link are in the connection
table (conn tab). Checks to see if the socket is open, if so
returns a pointer to the socket. If not in conn tab or socket
not open returns zero
algorithm:
if host link in conn tab
if skt open
return socket ptr
return zero
parameters:
link link to be checked with current host
returns:
zero if not in conn tab or socket not open
socket ptr if in conn tab and socket open
globals:
imp.host
sktp->r_flags
calls:
incontab to see if host link is in conn tab
called by:
imp_input
siguser
allocate
history:
initial coding 1/7/75 by Steve Holmgren
*/
imphostlink( link )
char link;
{
register sktp;
if( sktp = incontab( ((imp.host<<8) | (link & 0377)),0 ))
{
sktp = sktp->c_siptr; /* contab returns ptr to entry
must get skt pointer
*/
return( sktp );
}
return( 0 );
}