SRI-NOSC/ncpk/dti/impi1.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/src.h"
/*
defines for dealing with host to host protocol */
#define hhnop 0 /* nop */
#define hhall 4 /* allocate */
/* this array is indexed by the above op codes to give the length of the command */
char hhsize[14]
{
1, /* nop */
10, /* rts */
10, /* str */
9, /* cls */
8, /* all */
4, /* gvb */
8, /* ret */
2, /* inr */
2, /* ins */
2, /* eco */
2, /* erp */
12, /* err */
1, /* rst */
1 /* rrp */
};
/* this array holds the rfnm wait bits for sending allocations to hosts */
char host_map[32];
/*
name:
imp_iint
function:
Simply wakes up the input handling process to tell something
has arrived from the network
algorithm:
calls wakeup
parameters:
none
returns:
i hope so
globals:
imp_proc
calls:
wakeup to start input handling process running
called by:
hardware
history:
coded by Steve Holmgren 04/28/75
*/
imp_iint()
{
wakeup( &imp );
}
/* name:
imp_input
function:
Started in response to a wakeup from the input interrupt
initiates and switches all transfers received from the imp.
algorithm:
There are two logical states -
1. The driver will setup an 8 byte read from the imp when
it is in the leader state evidenced by impleader != 0
even if there is more data to be received from the imp
the interface will interrupt and come here for decoding.
2. After a leader has been received and the endmsg bit of
interface is not sent, the driver falls into a data
buffering mode reloaded by ihbget until the endmsg
flag is raised.
if buffering data
call hh let him handle it
else
if leaderread and endmsg means imp to host msg received
call ih and let him deal with that type
else
must be a normal leader with further data waiting in imp
is imp pad byte != 0
yes error do stats and flush imp
else
legal leader
if hh protocol msg (imp.link == 0)
set flag
continue buffering data
else
if host & link number are in conntab
then set ptr to associated inode
and continue reading data
else
error flush imp
parameters:
none
returns:
nothing
globals:
impleader= toggle as to whether doing leader reads
struct imp struct for accessing various imp leader fields
impiptr= set to addr of user inode
calls:
hh to handle hh protocol msgs
ih to handle imp to host protocol msgs
flushimp to keep reading data until endmsg is on
ihbget to reload imp with fresh imp data buffer
imphostlink to look host link number up in conn tab return sktp ptr
called by:
history:
initial coding 1/7/75 by Steve Holmgren
*/
imp_input() /* imp input handler */
{
/* check of imp error bit */
if (IMPADDR->istat < 0 && IMPADDR -> iwcnt != 0) /* imp incomplete sets error also */
{
printf("IMP error -- resetting\n");
while( IMPADDR->istat < 0 )
imp_init();
return;
}
if (impleader == 0) /* leader read ? */
hh(); /* no data is being buffered */
else
{
if( IMPADDR->istat & iendmsg ) /* ih msg? */
ih(); /* yes let him deal with it */
else
{ /* host to host leader */
/* legal leader */
if( ((imp.type&07) != 0) || (imp.pad1 != 0) )
{
iherr:
impiptr = 0;
imp_stat.i_leaderr++;
flushimp();
return;
}
else
{ /* yes legal leader */
if (imp.link == 0) /* hh protocol? */
{
impiptr = 0;
nxtbuf:
ihbget();
return;
}
/* data read -- we know this guy?? */
if( impiptr = imphostlink( imp.link & 0177 ))
goto nxtbuf; /* got iptr cont reading */
else
{
goto iherr; /* whos he err */
}
}
}
}
}
/* name:
hh
function:
If data received was not an imp leader to continue buffering
until endmsg is raised on imp interface, once raised, msg is
switched either to user or passed to hh1 for further decoding
and possible switching.
algorithm:
if endmsg raised
if flushing imp
discard data
reset flushing switch
if data for user
indicate error
allow him to run
else
not flushing so data is either for ncp daemon or user
decrement users byte allocation by msg size
link msg to user msg queue
increment users msg queue byte total
let user run
msg is a host to host msg call hh1 for further decoding
start another leader read
else
endmsg not set so either keep buffering or flushing
if flushing
keep flushing
else
keep reading
parameters:
none
returns:
nothing
globals:
impmsg->b_len=
impflushing=
sktp->r_flags=
sktp->r_bytes=
sktp->r_msgs=
sktp->r_msgq
sktp->r_qtotal=
calls:
freemsg to destroy buffer data
wakeup (sys) to allow user to run
bytesout to destroy first data byte
rmovepad to remove imp padding and set length
to_ncp to pass data to ncpdaemon
hh1 for further decoding and switching of data
impldrd to start another leader read
flushimp to continue flushing data from imp
ihbget continue bufferin data
called by:
imp_input
history:
initial coding 1/7/75 by Steve Holmgren
check for something in impmsg 8/16/76 S. Holmgren
modified to do send events 12/8/76 by David Healy
*/
hh()
{
register struct rdskt *sktp;
register struct netbuf *bufp;
int temp;
sktp = impiptr;
if( impmsg ) /* if there is anything in the msg */
impmsg->b_len = net_b_size; /* by defination the buffer
is either full or the last.
if last rmovepad will set
length correctly */
if( IMPADDR->istat & iendmsg) /* end of msg? */
{
if( impflushing ) /* finished flushing */
{
freemsg( impmsg ); /* destroy any bfred data */
impmsg = 0; /* get rid of previous msg */
impflushing = 0; /* reset flushing */
if (sktp) /* was user proc involved */
{
sktp->r_flags =| n_eof; /* set err */
if (sktp -> w_flags & n_nbio)
ipc_trans (SRC_READ | (1 << 8),
sktp -> r_pid, sktp -> r_ufid, -1);
else
wakeup( sktp );
}
}
else
{
if( impmsg == 0 ) /* empty msg? */
{
printf("zero impmsg\n");
return;
}
if( bytesout( &impmsg,&temp,1,1 ) )
printf("imp odd byte\n");
if( rmovepad() ) /* remove padding and set len */
{
impldrd();
return;
}
if (sktp) /* user or hh msg? */
{
if( sktp->r_flags&n_toncp) /* data to ncp? */
to_ncp(impncp,5,impmsg);
else /* no give to user and wakeup */
{
/* dec msgs allocated */
sktp->r_msgs--;
sktp->r_qtotal =+ implen;
sktp->r_msgq = catmsg( sktp->r_msgq,impmsg );
if (sktp -> r_flags & n_nbio)
{
if (sktp -> r_flags & n_event)
{
ipc_trans (SRC_READ | (1 << 8), sktp -> r_pid,
sktp -> r_ufid, sktp -> r_qtotal);
sktp -> r_flags =& ~n_event;
}
}
else
wakeup( sktp );
}
}
else /* nope hh msg */
hh1(); /* let him handle this */
}
impldrd(); /* start another leader read */
}
else
if (IMPADDR -> iwcnt == 0) /* how about buffer full then */
{
/* not end msg - keep flushing or reading */
if( impflushing ) /* flushing? */
flushimp(); /* yes - keep flushing */
else
ihbget(); /* no cont reading data */
}
else
printf("IMP interface spurious interrupt\n");
}
/* name:
ih
function:
To look at all imp to host messages and handle rfnms, incomplete
transmissions, and nops
algorithm:
if imp.type is request for next message (rfnm)
tell user rfnm arrived
if imp.type is nop
start another leader read
if imp.type is error_in_data or incomplete_transmission
tell user last data he sent is in error or imp couldnt handle
if imp.type is non of the above
send imp leader to ncpdaemon for processing
in any case start another leader read
parameters:
none
returns:
nothing
globals:
imp.type
calls:
siguser to let user see rfnms, incomptrans or err data
to_ncp to ship leaders to ncpdaemon
impldrd to start another leader read
calls:
called by:
imp_input
history:
initial coding 1/7/75 by Steve Holmgren
*/
ih()
{
switch( imp.type )
{
case ih_rfnm: siguser( n_rfnm ); /* tell user rfnm arrived */
case ih_nop: break; /* ignore nops */
case ih_edata:
case ih_ictrans:siguser( n_xmterr ); /* tell user about his problem */
break;
default: to_ncp( impncp,5,0 ); /* send leader to ncp */
}
impldrd(); /* start another leader read */
}
/* name:
siguser
function:
ostensibly to or the parameter into the users flag field and
let him run. If the socket is closed send a close command
to the ncp daemon he was waiting for a msg to clear the imp sys
If the ncp daemon is monitoring all data going to a user send
the rfnm to him
if this is a host to host protocol rfnm let the ncp daemon
know he can now send further protocol msgs to that host.
algorithm:
If imp.link!=0 andif the host link entry is in the conn tab
If conn closed
send close to ncpdaemon
if data for ncpdaemon
send leader to ncpdaemon
else
or param into flag field
if got a rfnm
update msg and bit allocations
if non blocking i/o
if event wanted
send rfnm or xmiterr event
else
wakeup user
turn of waiting and n_event bits
else
host to host protocol return response so
allow ncpdaemon to process
parameters:
sigflg bits to be ored into the users flag field
returns:
nothing
globals:
imp.link
impncp
conentry->w_flags=
calls:
imphostlink to relate host link to socket entry
wakeup (sys) to allow user to run
to_ncp to send data to ncp daemon
called by:
ih
history:
initial coding 1/7/75 by Steve Holmgren
removed check for rfnm so incomplete transmissions
will also reset the host rfnm bit 8/20/76 S. Holmgren
modified to send completion events 12/8/76 by David Healy
*/
siguser( sigflg ) /* called when user needs waking up. the
passed flag is ored into his flag field
and he is awakened */
{
register conentry;
register src; /* for sending events */
register int cnt; /* for sending events */
if( imp.link != 0 )
{
if( (conentry = imphostlink( imp.link | 0200 )) == 0 )
{
/* printf("rfnm on bad link %o %o\n",imp.host,imp.link); /* */
to_ncp( impncp,5,0 );
return;
}
if( (conentry->w_flags&n_open) == 0 )
return;
if( conentry->w_flags & n_toncp )
to_ncp( impncp,5,0 ); /* give to ncp */
else
{
conentry -> w_flags =& ~n_waiting;
conentry->w_flags =| (sigflg); /* set flags */
if (sigflg & n_rfnm) /* update allocation? */
{
conentry -> w_msgs =- 1; /* dec msg cnt */
dpsub (conentry -> w_falloc, conentry -> w_xfalloc); /* and bits */
conentry->w_xfalloc = 0;
}
if (conentry -> w_flags & n_nbio)
{
conentry -> w_flags =| n_event;
src = (sigflg & n_rfnm) ? SRC_WRITE : SRC_NAK;
if ((cnt = anyalloc (conentry)) || src == SRC_NAK)
{
conentry -> w_flags =& ~n_event;
ipc_trans (src | (1 << 8), conentry -> w_pid, conentry -> w_ufid,cnt);
}
}
else
wakeup( conentry );
}
}
else
{
/* user waiting for control link rfnm? */
if( bit_on( host_map,imp.host & 0377) != 0 )
{
/* say rfnm here */
reset_bit( host_map,imp.host & 0377);
/* let any users battle it out */
wakeup( host_map+(imp.host&0377) );
}
else
/* no users waiting ship to daemon */
to_ncp( impncp,5,0 );
}
}