4.3BSD-Reno/src/sys/net/if_loop.c

/*
 * Copyright (c) 1982, 1986 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution is only permitted until one year after the first shipment
 * of 4.4BSD by the Regents.  Otherwise, redistribution and use in source and
 * binary forms are permitted provided that: (1) source distributions retain
 * this entire copyright notice and comment, and (2) distributions including
 * binaries display the following acknowledgement:  This product includes
 * software developed by the University of California, Berkeley and its
 * contributors'' in the documentation or other materials provided with the
 * distribution and in all advertising materials mentioning features or use
 * of this software.  Neither the name of the University nor the names of
 * its contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 *	@(#)if_loop.c	7.10 (Berkeley) 6/28/90
 */

/*
 * Loopback interface driver for protocol testing and timing.
 */

#include "param.h"
#include "systm.h"
#include "mbuf.h"
#include "socket.h"
#include "errno.h"
#include "ioctl.h"

#include "../net/if.h"
#include "../net/if_types.h"
#include "../net/netisr.h"
#include "../net/route.h"

#include "machine/mtpr.h"

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

#ifdef NS
#include "../netns/ns.h"
#include "../netns/ns_if.h"
#endif

#ifdef ISO
#include "../netiso/iso.h"
#include "../netiso/iso_var.h"
#endif

#define	LOMTU	(1024+512)

struct	ifnet loif;
int	looutput(), loioctl();

loattach()
{
	register struct ifnet *ifp = &loif;

	ifp->if_name = "lo";
	ifp->if_mtu = LOMTU;
	ifp->if_flags = IFF_LOOPBACK;
	ifp->if_ioctl = loioctl;
	ifp->if_output = looutput;
	ifp->if_type = IFT_LOOP;
	ifp->if_hdrlen = 0;
	ifp->if_addrlen = 0;
	if_attach(ifp);
}

struct mbuf *Loop_Sanity;

looutput(ifp, m, dst)
	struct ifnet *ifp;
	register struct mbuf *m;
	struct sockaddr *dst;
{
	int s;
	register struct ifqueue *ifq;

	if ((m->m_flags & M_PKTHDR) == 0)
		panic("looutput no HDR");
	m->m_pkthdr.rcvif = ifp;

{struct mbuf *mm; int mlen = 0;
for (mm = m; m; m = m->m_next) /* XXX debugging code -- sklower */
    mlen += m->m_len;
m = mm;
if (mlen != m->m_pkthdr.len) {
	if (Loop_Sanity)
		m_freem(Loop_Sanity);
	Loop_Sanity = m_copy(m, 0, (int)M_COPYALL);
}
}

	s = splimp();
	ifp->if_opackets++;
	ifp->if_obytes += m->m_pkthdr.len;
	switch (dst->sa_family) {

#ifdef INET
	case AF_INET:
		ifq = &ipintrq;
		if (IF_QFULL(ifq)) {
			IF_DROP(ifq);
			m_freem(m);
			splx(s);
			return (ENOBUFS);
		}
		IF_ENQUEUE(ifq, m);
		schednetisr(NETISR_IP);
		break;
#endif
#ifdef NS
	case AF_NS:
		ifq = &nsintrq;
		if (IF_QFULL(ifq)) {
			IF_DROP(ifq);
			m_freem(m);
			splx(s);
			return (ENOBUFS);
		}
		IF_ENQUEUE(ifq, m);
		schednetisr(NETISR_NS);
		break;
#endif
#ifdef ISO
	case AF_ISO:
		ifq = &clnlintrq;
		if (IF_QFULL(ifq)) {
			IF_DROP(ifq);
			m_freem(m);
			splx(s);
			return (ENOBUFS);
		}
		IF_ENQUEUE(ifq, m);
		schednetisr(NETISR_ISO);
		break;
#endif
	default:
		splx(s);
		printf("lo%d: can't handle af%d\n", ifp->if_unit,
			dst->sa_family);
		m_freem(m);
		return (EAFNOSUPPORT);
	}
	ifp->if_ipackets++;
	ifp->if_ibytes += m->m_pkthdr.len;
	splx(s);
	return (0);
}

/*
 * Process an ioctl request.
 */
/* ARGSUSED */
loioctl(ifp, cmd, data)
	register struct ifnet *ifp;
	int cmd;
	caddr_t data;
{
	int error = 0;

	switch (cmd) {

	case SIOCSIFADDR:
		ifp->if_flags |= IFF_UP;
		/*
		 * Everything else is done at a higher level.
		 */
		break;

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