/*	$OpenBSD: if_enc.c,v 1.9 1998/06/28 18:49:40 deraadt Exp $	*/

/*
 * The authors of this code are John Ioannidis (ji@tla.org),
 * Angelos D. Keromytis (kermit@csd.uch.gr) and 
 * Niels Provos (provos@physnet.uni-hamburg.de).
 *
 * This code was written by John Ioannidis for BSD/OS in Athens, Greece, 
 * in November 1995.
 *
 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
 * by Angelos D. Keromytis.
 *
 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
 * and Niels Provos.
 *
 * Copyright (C) 1995, 1996, 1997, 1998 by John Ioannidis, Angelos D. Keromytis
 * and Niels Provos.
 *	
 * Permission to use, copy, and modify this software without fee
 * is hereby granted, provided that this entire notice is included in
 * all copies of any software which is or includes a copy or
 * modification of this software. 
 * You may use this code under the GNU public license if you so wish. Please
 * contribute changes back to the authors under this freer than GPL license
 * so that we may further the use of strong encryption without limitations to
 * all.
 *
 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
 * PURPOSE.
 */

/*
 * Encapsulation interface driver.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/errno.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <machine/cpu.h>

#include <net/if.h>
#include <net/if_types.h>
#include <net/netisr.h>
#include <net/route.h>
#include <net/bpf.h>
#include <net/if_enc.h>

#ifdef	INET
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#endif

#ifdef ISO
extern struct ifqueue clnlintrq;
#endif

#ifdef NS
extern struct ifqueue nsintrq;
#endif

#include "bpfilter.h"

struct ifnet enc_softc;

void	encattach __P((int));
int	encoutput __P((struct ifnet *, struct mbuf *, struct sockaddr *,
	    	       struct rtentry *));
int	encioctl __P((struct ifnet *, u_long, caddr_t));
void	encrtrequest __P((int, struct rtentry *, struct sockaddr *));

void
encattach(int nenc)
{
	struct ifaddr *ifa;

	bzero(&enc_softc, sizeof(struct ifnet));

	/* We only need one interface anyway under the new mode of operation */
	enc_softc.if_index = 0;

	sprintf(enc_softc.if_xname, "enc0");
	enc_softc.if_list.tqe_next = NULL;
	enc_softc.if_mtu = ENCMTU;
	enc_softc.if_flags = IFF_LOOPBACK;
	enc_softc.if_type = IFT_ENC;
	enc_softc.if_ioctl = encioctl;
	enc_softc.if_output = encoutput;
	enc_softc.if_hdrlen = ENC_HDRLEN;
	enc_softc.if_addrlen = 0;
	if_attach(&enc_softc);

#if NBPFILTER > 0
	bpfattach(&enc_softc.if_bpf, &enc_softc, DLT_ENC, ENC_HDRLEN);
#endif

	/* Just a bogus entry */
	ifa = (struct ifaddr *) malloc(sizeof(struct ifaddr) + 
	    sizeof(struct sockaddr), M_IFADDR, M_WAITOK);
	bzero(ifa, sizeof(struct ifaddr) + sizeof(struct sockaddr));
	ifa->ifa_addr = ifa->ifa_dstaddr = (struct sockaddr *) (ifa + 1);
	ifa->ifa_ifp = &enc_softc;
	TAILQ_INSERT_HEAD(&(enc_softc.if_addrlist), ifa, ifa_list);
}

/*
 * Shamelessly stolen from looutput()
 */
int
encoutput(ifp, m, dst, rt)
struct ifnet *ifp;
register struct mbuf *m;
struct sockaddr *dst;
register struct rtentry *rt;
{
	register struct ifqueue *ifq = 0;
	int s, isr;

	if ((m->m_flags & M_PKTHDR) == 0)
		panic("encoutput(): no HDR");

	ifp->if_lastchange = time;
	m->m_pkthdr.rcvif = ifp;
    
	if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
		m_freem(m);
		return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
		    rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
	}

	ifp->if_opackets++;
	ifp->if_obytes += m->m_pkthdr.len;

	switch (dst->sa_family) {
#ifdef INET
	case AF_INET:
		ifq = &ipintrq;
		isr = NETISR_IP;
		break;
#endif
#ifdef NS
	case AF_NS:
		ifq = &nsintrq;
		isr = NETISR_NS;
		break;
#endif
#ifdef ISO
	case AF_ISO:
		ifq = &clnlintrq;
		isr = NETISR_ISO;
		break;
#endif
	default:
		m_freem(m);
		return (EAFNOSUPPORT);
	}
    
	s = splimp();
	if (IF_QFULL(ifq)) {
		IF_DROP(ifq);
		m_freem(m);
		splx(s);
		return (ENOBUFS);
	}
	
	IF_ENQUEUE(ifq, m);
	schednetisr(isr);

	/* Statistics */
	ifp->if_ipackets++;
	ifp->if_ibytes += m->m_pkthdr.len;
	splx(s);
	return (0);
}

/* ARGSUSED */
void
encrtrequest(cmd, rt, sa)
	int cmd;
	struct rtentry *rt;
	struct sockaddr *sa;
{
	if (rt)
		rt->rt_rmx.rmx_mtu = ENCMTU;
}

/* ARGSUSED */
int
encioctl(ifp, cmd, data)
	register struct ifnet *ifp;
	u_long cmd;
	caddr_t data;
{
	register struct ifaddr *ifa;
	register int error = 0;

	switch (cmd) {
	case SIOCSIFADDR:
		/*
		 * Everything else is done at a higher level.
		 */
		ifp->if_flags |= IFF_UP;
		ifa = (struct ifaddr *) data;
		break;

	default:
		error = EINVAL;
		break;
	}
	return (error);
}