#

#include	"util.h"
#include	"pkts.h"
#include	"buf.h"
#include	<ioctl.h>

/* inet_init  store away constant inet info in tcb
and tcb send pkt.  Compute max tcp segment (data) size we
will accept.
*/
inet_init(ptcb, fhost)
struct tcb	*ptcb;
long		fhost;
{
	register struct inet_hdr	*inp;
	register struct tcp_phdr	*phd;

	struct maxdata {
		long	md_fhost;
		short	md_maxfrag;
		}	maxdata;
	register struct maxdata	*mdp;

	inp = &ptcb->t_inet;

	inp->ip_ihlver = IP_VERHL;
	inp->ip_tsrv = IP_TSRV;
	inp->ip_frag = 0;
	inp->ip_time = IP_TIME;
	inp->ip_prot = TCPPROT;
	inp->ip_src = mymach;
	inp->ip_dest = fhost;

	phd = &ptcb->t_phdr;
	phd->pt_src = mymach;
	phd->pt_dest = fhost;
	phd->pt_zero = 0;
	phd->pt_prot = TCPPROT;

	mdp = &maxdata;
	mdp->md_fhost = fhost;
	mdp->md_maxfrag = 0;
	ioctl(net, NIONWRITE, mdp);
	mdp->md_maxfrag -= (IPHSIZ + TCPHSIZ);
	ptcb->t_maxdata = (mdp->md_maxfrag < MAXDATA) ?
				mdp->md_maxfrag:MAXDATA;
	ptcb->t_maxsdata = ptcb->t_maxdata;
	if (ptcb->t_maxdata < 5) {
		logerr("inet_init  data size too small %d fhost %X\n",
			ptcb->t_maxdata, fhost);
		return(FALSE);
		}

	return(TRUE);
}

ch_inet(ptcb, ppkt)
struct tcb		*ptcb;
register struct rcvpkt	*ppkt;
{
	register struct inet_hdr	*inp;

	inp = &ppkt->rp_inet;

	if ( (((inp->ip_ihlver & 017) << 2) > ppkt->rp_len) ||
		(inp->ip_len < IPHSIZ) ||
		(inp->ip_len > ppkt->rp_len) ) {
		logerr("ch_inet bad rcvpkt or inet length %d %d\n",
			ppkt->rp_len, inp->ip_len);
		return(FALSE);
		}

	if ((inp->ip_prot != TCPPROT) ||
		(inp->ip_src != ptcb->t_inet.ip_dest) ||
		(inp->ip_dest != mymach)) {
		logerr("ch_inet  bad protocol, src host,or dest host %d %X %X\n",
			inp->ip_prot, inp->ip_src, inp->ip_dest);
		return(FALSE);
		}

	return(TRUE);
}

ch_security(ptcb, inp)
struct tcb			*ptcb;
register struct inet_hdr	*inp;
{
	register char	*ipo, *ipoe;
	short		*security, *compart;
	short		iphlen;

	if ((inp->ip_tsrv & 0340) != 0) {
		logerr("ch_security  bad precedence fhost %X\n",
			inp->ip_src);
		return(FALSE);
		}

	iphlen = (inp->ip_ihlver & 017) << 2;
	if (iphlen <= IPHSIZ) return(TRUE);

	ipo = (char *) inp + IPHSIZ;
	ipoe = (char *) inp + iphlen;
	while (ipo < ipoe) {
		switch(*ipo) {
		case 0:
			return(TRUE);
		case 1:
			ipo++;
			break;
		default:
			if (*ipo == IPOPT_SECURITY) {
				security = ipo + 2;
				compart = ipo + 4;
				if (*security || *compart) {
					logerr("ch_security  bad security fhost %X\n",
						inp->ip_src);
					return(FALSE);
					}
				return(TRUE);
				}
			ipo += (*(ipo + 1));
			break;
			}
		}

	return(TRUE);
}