#
#include	"../h/param.h"
#include	"../h/user.h"
#include	"../h/userx.h"
#include	"../h/buf.h"
#include	"../h/inode.h"
#include	"../h/file.h"
#include	"../h/reg.h"
#include	"../h/pkts.h"
#include	"../h/net.h"

extern		viixmt();

/* Xmit i/o contol block
* Interlock via B_BUSY bit
* Interlocking done by physio(bio.c) and
*  viixint(vii.c) wh. calls iodone(bio.c);
* If a strange error situation occurs,
* netflush(vii.c) may unlock buffer
*/
struct buf	xmtbuf;


netwrite(dev)
{
	struct pkt		pkbuf;
	register struct pkt	*uppkt, *ppkt;
	register short		iphlen;
	struct netino		*nip;

/* addrok called by physio
   Assume for copyin and copyout that pkt is
   in user data space and that copyin/copyout
   will return(-1) if mem. fault encountered
	if (addrok()) return;
*/

	uppkt = u.u_base;
	iphlen = (fubyte(&uppkt->pk_inet.ip_ihlver) & 017) << 2;
	if ((iphlen < IPHSIZ) || (iphlen > (IPHSIZ + IPOPTSZ)) ) 
		return( netu_err(ENOSPC) );
	if (copyin(&uppkt->pk_inet, &pkbuf.pk_inet, iphlen) == ERR) 
		return( netu_err(EFAULT) );

	ppkt = &pkbuf;

	if (mk_inet(&ppkt->pk_inet, u.u_count) == ERR) 
		return( netu_err(ENOSPC) );

	nip = (u.u_ofile[u.u_ar0[R0]])->f_inode;
	if (mk_net(ppkt, nip) == ERR)
		return( netu_err(EACCES) );

	if (copyout(ppkt, uppkt, (NETHSIZ + IPHSIZ)) == ERR)
		return( netu_err(EFAULT) );

	physio(&viixmt, &xmtbuf, dev, B_WRITE);
}

netwr_done()
{
	if (xmtbuf.b_flags & B_BUSY) {
		neterrp("last net close and xmtbuf busy",
			neti_que.q_head, xmtbuf.b_flags, PROGERR);
		return(FALSE);
		}

	return(TRUE);
}

netread(dev)
{
	register struct netino	*nip;
	register struct rcvpkt	*rp;
	struct buf		rbuf;
	register struct buf	*bp;
	short			flag;

	nip = (u.u_ofile[u.u_ar0[R0]])->f_inode;

	spl6();
	for (rp = rcvpktdir.rd_head; rp != NULL;
		rp = rp->rp_forw) 
		if (rp->rp_inode == nip) break;

	if (rp == NULL) goto done;
	if (rp->rp_len > u.u_count) {
		u.u_error = ENOSPC;
		goto done;
		}
	rp->rp_flags |= N_LOCK;
	spl0();

	bp = &rbuf;
	bp->b_addr = &rp->rp_net;
	iomove(bp, 0, rp->rp_len, B_READ);

	spl6();
	flag = rp->rp_flags;
	if (u.u_error == 0)
		netp_deque(rp);
	else
		rp->rp_flags &= (~(N_LOCK|N_WANTED));
	if (flag & N_WANTED)
		netr_start();

done:	spl0();
	return;
}

/* netrcnt
Search rcv memory for first packet for
net connection nip - return packet length
*/
netrcnt(nip)
register struct netino	*nip;
{
	register struct rcvpkt *rp;
	register int		nbyte;

	nbyte = 0;

	spl6();
	for (rp = rcvpktdir.rd_head; rp != NULL;
		rp = rp->rp_forw)
		if (rp->rp_inode == nip) {
			nbyte = rp->rp_len;
			break;
			}
	spl0();

	return(nbyte);
}