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


/* Net inode queue
* Queue is modified by netopen, netclose, and ioctl;
*  it is not modified at interrupt time
* Queue is searched at interrupt time as well
*  as non-interrupt time
* Interlocking rule:  lock out interrupts when
*  modify queue but not when search it
*/
struct que	neti_que;	


netinit()
{
	viiinit();		

	neti_que.q_head = NULL;
	neti_que.q_tail = NULL;
	neti_que.q_cnt = 0;

	netr_init();

	inn_init();
}

/* netopen
nt_rte filled w. local net first hop dest. addr.
if foreign host is specified in net connection and
1) foreign host is on my net/subnet or
2) foreign host is in host gate table
*/
netopen()
{
	extern			uchar;
	register struct inode	*ip;
	register struct netino	*nip;
	register struct netdf	*netdp;
	int			dev;
	int			prot;
	int			err;
	register struct file	*fp;

	if ( (ip = namei(&uchar, 0)) == NULL) return;
	dev = ip->i_addr[0];
	iput(ip);
	if (dev != netdev) {
		u.u_error = ENODEV;
		return;
		}

	netdp = u.u_arg[1];

	prot = fuword(&netdp->n_prot1);
	if (prot != INETPROT) {
		u.u_error = EINVAL;
		return;
		}

	if ( (ip = ialloc(rootdev)) == NULL) return;
	ip->i_flag = IACC|IUPD;
	ip->i_mode = IALLOC|IFCHR|0666;
	ip->i_addr[0].d_major = dev.d_major & 0377;

	nip = ip;
	nip->nt_flags = NINTRUP;
	nip->nt_prot = fuword(&netdp->n_prot2);
	nip->nt_fhost.nt_shost[0] = fuword(&netdp->n_sfhost[0]);
	nip->nt_fhost.nt_shost[1] = fuword(&netdp->n_sfhost[1]);
	nip->nt_fskt = fuword(&netdp->n_fskt);
	nip->nt_lskt = fuword(&netdp->n_lskt);
	nip->nt_procp = u.u_procp;
	nip->nt_rte = net_rte(nip->nt_fhost.nt_lhost);

	if ((err = net_dchk(nip)) != 0) {
		u.u_error = err;
		iput(ip);
		return;
		}

	if ( (fp = falloc()) == NULL) {
		iput(ip);
		return;
		}
	fp->f_flag = FREAD|FWRITE;
	fp->f_inode = nip;

	spl6();
	neti_enque(&neti_que, nip);
	spl0();

	netr_start();
	spl0();

#ifdef	DEBUG
	show_niq();
#endif
}

/* net_dchk  chk net definition
* TCP protocol rules:
*  local socket must be specified
*  foreign host/socket must both be specified 
*   or both be NULL
*  connection must be unique
* Datagram protocol rules:
*  if local is NULL, foreign host/socket
*   must be NULL
*  if local socket is specified,
*  foreign host/socket must both be specified
*   or both be NULL
*  local socket must be unique
*  if foreign host/socket are specified,
*   pair must be unique
* Otherwise
*  foreign host, foreign socket and local
*   socket must be NULL
*  connection must be unique
*/
net_dchk(nip)
register struct netino	*nip;
{
	register int		prot;
	register struct netino	*nip2;

	prot = nip->nt_prot;

	switch(prot) {
	case TCPPROT:
		if ( (nip->nt_lskt == NULL) ||
			((nip->nt_fhost.nt_lhost == NULL) && (nip->nt_fskt != NULL)) ||
			((nip->nt_fhost.nt_lhost != NULL) && (nip->nt_fskt == NULL)) )
				return(EINVAL);

		for (nip2 = neti_que.q_head; nip2 != NULL;
			nip2 = nip2->nt_forw) 
			if ((prot == nip2->nt_prot) &&
				(nip->nt_fhost.nt_lhost == nip2->nt_fhost.nt_lhost) &&
				(nip->nt_fskt == nip2->nt_fskt) &&
				(nip->nt_lskt == nip2->nt_lskt) ) 
					return(EACCES);

		break;

	case DGPROT:
		if (nip->nt_lskt == NULL) {
			if ((nip->nt_fhost.nt_lhost != NULL) ||
				(nip->nt_fskt != NULL) ) return(EINVAL);
			}
		else {
			if ( ((nip->nt_fhost.nt_lhost == NULL) && (nip->nt_fskt != NULL)) ||
			((nip->nt_fhost.nt_lhost != NULL) && (nip->nt_fskt == NULL)) )
				return(EINVAL);
			}

		for (nip2 = neti_que.q_head; nip2 != NULL;
			nip2 = nip2->nt_forw)
			if ( (prot == nip2->nt_prot) &&
				((nip->nt_lskt == nip2->nt_lskt) ||
				( (nip->nt_fhost.nt_lhost != NULL) &&
				  (nip->nt_fhost.nt_lhost == nip2->nt_fhost.nt_lhost) &&
				   (nip->nt_fskt == nip2->nt_fskt) ) ) )
				return(EACCES);

		break;

	default:
		if ( (nip->nt_fhost.nt_lhost != NULL) ||
			(nip->nt_fskt != NULL) ||
			(nip->nt_lskt != NULL) ) 
				return(EINVAL);

		for (nip2 = neti_que.q_head; nip2 != NULL;
			nip2 = nip2->nt_forw)
			if (prot == nip2->nt_prot) 
				return(EACCES);

		break;
		}

	return(0);
}

netclose(fp)
register struct file	*fp;
{
	register struct netino	*nip;

	nip = fp->f_inode;

	if (--fp->f_count > 0) {
		if ( (nip->nt_flags & NINTRUP) &&
			(nip->nt_procp == u.u_procp) ) {
			nip->nt_flags &= (~NINTRUP);
			nip->nt_procp = NULL;
			}
		return;
		}

	spl6();
	neti_deque(&neti_que, nip);
	neti_pdque(nip);
	spl0();

	iput(nip);

#ifdef	DEBUG
	show_niq();
#endif
	if (neti_que.q_cnt == 0) {
		netwr_done();
		netflush();
		}

	return;
}

neti_enque(pque, nip)
register struct que	*pque;
register struct netino	*nip;
{
	nip->nt_forw = NULL;
	nip->nt_back = pque->q_tail;

	if (pque->q_head == NULL)
		pque->q_head = nip;
	else
		pque->q_tail->nt_forw = nip;
	pque->q_tail = nip;

	pque->q_cnt++;
}

neti_deque(pque, nip)
register struct que	*pque;
register struct netino	*nip;
{
	if (nip->nt_back == NULL)
		pque->q_head = nip->nt_forw;	/* First on queue */
	else
		nip->nt_back->nt_forw = nip->nt_forw;

	if (nip->nt_forw == NULL)
		pque->q_tail = nip->nt_back;	/* Last on queue */
	else
		nip->nt_forw->nt_back = nip->nt_back;

	pque->q_cnt--;
}


netu_err(ecode)
short	ecode;
{
	u.u_error = ecode;
}
	
#ifdef	DEBUG
show_niq()
{
	register struct netino	*nip;

	printf("\nNeti_que\n");

	for (nip = neti_que.q_head; nip != NULL;
		nip = nip->nt_forw) {
		printf("nip %o forw %o back %o dev %o flags %o procp %o\n",
			nip, nip->nt_forw, nip->nt_back, nip->nt_dev,
			nip->nt_flags, nip->nt_procp);
		printf("   prot %d lskt %d fhost %o %o fskt %d\n",
			nip->nt_prot, nip->nt_lskt,
			nip->nt_fhost.nt_shost[0], nip->nt_fhost.nt_shost[1],
			nip->nt_fskt);
		}
}
#endif