Ultrix-3.1/sys/net/if_loop.c

/**********************************************************************
 *   Copyright (c) Digital Equipment Corporation 1984, 1985, 1986.    *
 *   All Rights Reserved. 					      *
 *   Reference "/usr/src/COPYRIGHT" for applicable restrictions.      *
 **********************************************************************/

/*
 * Copyright (c) 1982 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 *
 * SCCSID: @(#)if_loop.c	3.0	4/21/86
 *	Based on: @(#)if_loop.c	6.6 (Berkeley) 6/8/85
 */

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

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <errno.h>
#include <sys/ioctl.h>

#include <net/if.h>
#include <net/netisr.h>
#include <net/route.h>

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>

#ifdef vax
#include "../vax/mtpr.h"
#endif

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

#define	LOMTU	(1024+512)

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

static char LOname[] = { 'l', 'o', '\0' };
loattach()
{
	register struct ifnet *ifp = &loif;
	register struct sockaddr_in *sin;

	ifp->if_name = "lo";
	ifp->if_mtu = LOMTU;
	ifp->if_ioctl = loioctl;
	ifp->if_output = looutput;
	if_attach(ifp);
}

looutput(ifp, m0, dst)
	struct ifnet *ifp;
	struct mbuf *m0;
	struct sockaddr *dst;
{
	int s = splimp();
	register struct ifqueue *ifq;

	ifp->if_opackets++;
	switch (dst->sa_family) {

#ifdef INET
	case AF_INET:
		ifq = &ipintrq;
		if (IF_QFULL(ifq)) {
			IF_DROP(ifq);
			m_freem(m0);
			splx(s);
			return (ENOBUFS);
		}
		IF_ENQUEUE(ifq, m0);
		schednetisr(NETISR_IP);
		break;
#endif
#ifdef NS
	case AF_NS:
		ifq = &nsintrq;
		if (IF_QFULL(ifq)) {
			IF_DROP(ifq);
			m_freem(m0);
			splx(s);
			return (ENOBUFS);
		}
		IF_ENQUEUE(ifq, m0);
		schednetisr(NETISR_NS);
		break;
#endif
	default:
		splx(s);
		printf("lo%d: can't handle af%d\n", ifp->if_unit,
			dst->sa_family);
		m_freem(m0);
		return (EAFNOSUPPORT);
	}
	ifp->if_ipackets++;
	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);
}