/*	$OpenBSD: if_enc.c,v 1.3 1997/02/27 04:05:45 angelos Exp $	*/

/*
 * The author of this code is John Ioannidis, ji@tla.org,
 * 	(except when noted otherwise).
 *
 * This code was written for BSD/OS in Athens, Greece, in November 1995.
 *
 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
 * by Angelos D. Keromytis, kermit@forthnet.gr.
 *
 * Copyright (C) 1995, 1996, 1997 by John Ioannidis and Angelos D. Keromytis.
 *	
 * 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.
 *
 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTY. IN PARTICULAR, NEITHER AUTHOR 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>

#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"

#define	ENCMTU	(1024+512)

/*
 * Called from boot code to establish enc interfaces.
 */

struct enc_softc
{
	struct ifnet enc_if;
} ;

struct enc_softc *enc_softc;

int nencap;

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)
{
	register struct enc_softc *enc;
	register int i = 0;

	nencap = nenc;
	
	enc_softc = malloc(nenc * sizeof (*enc_softc), M_DEVBUF, M_WAIT);
	bzero(enc_softc, nenc * sizeof (*enc_softc));
	for (enc = enc_softc; i < nenc; enc++)
	{
		enc->enc_if.if_index = i;
		sprintf(enc->enc_if.if_xname, "enc%d", i++);
		enc->enc_if.if_list.tqe_next = NULL;
		enc->enc_if.if_mtu = ENCMTU;
		enc->enc_if.if_flags = IFF_LOOPBACK;
		enc->enc_if.if_type = IFT_ENC;
		enc->enc_if.if_ioctl = encioctl;
		enc->enc_if.if_output = encoutput;
		enc->enc_if.if_hdrlen = 0;
		enc->enc_if.if_addrlen = 0;
		if_attach(&enc->enc_if);
#if NBPFILTER > 0
		bpfattach(&enc->enc_if.if_bpf, &enc->enc_if, DLT_NULL, sizeof(u_int));
#endif
	}
}

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

	/* register struct enc_softc *ec = &enc_softc[ifp->if_index]; */
	
	if ((m->m_flags & M_PKTHDR) == 0)
		panic("encoutput no HDR");
	ifp->if_lastchange = time;
#if NBPFILTER > 0
	if (ifp->if_bpf) {
		/*
		 * We need to prepend the address family as
		 * a four byte field.  Cons up a dummy header
		 * to pacify bpf.  This is safe because bpf
		 * will only read from the mbuf (i.e., it won't
		 * try to free it or keep a pointer a to it).
		 */
		struct mbuf m0;
		u_int af = dst->sa_family;

		m0.m_next = m;
		m0.m_len = 4;
		m0.m_data = (char *)&af;
		
		bpf_mtap(ifp->if_bpf, &m0);
	}
#endif
	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);
	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;
}

/*
 * Process an ioctl request.
 * Also shamelessly stolen from loioctl()
 */

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

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

		switch (ifr->ifr_addr.sa_family) {

#ifdef INET
		      case AF_INET:
			break;
#endif
		      case AF_ENCAP:
			break;
			
		      default:
			error = EAFNOSUPPORT;
			break;
		}
		break;

	      default:
		error = EINVAL;
	}
	return error;
}