xref: /csrg-svn/sys/net/if_loop.c (revision 54718)

/*
 * Copyright (c) 1982, 1986 Regents of the University of California.
 * All rights reserved.
 *
 * %sccs.include.redist.c%
 *
 *	@(#)if_loop.c	7.17 (Berkeley) 07/06/92
 */

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

#include "param.h"
#include "systm.h"
#include "kernel.h"
#include "mbuf.h"
#include "socket.h"
#include "errno.h"
#include "ioctl.h"
#include "machine/cpu.h"
#include "time.h"

#include "if.h"
#include "if_types.h"
#include "netisr.h"
#include "route.h"
#include "bpf.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

#include "bpfilter.h"

#define	LOMTU	(1024+512)

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

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

	ifp->if_name = "lo";
	ifp->if_mtu = LOMTU;
#ifdef MULTICAST
	ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
#else
	ifp->if_flags = IFF_LOOPBACK;
#endif
	ifp->if_ioctl = loioctl;
	ifp->if_output = looutput;
	ifp->if_type = IFT_LOOP;
	ifp->if_hdrlen = 0;
	ifp->if_addrlen = 0;
	if_attach(ifp);
#if NBPFILTER > 0
	bpfattach(&ifp->if_bpf, ifp, DLT_NULL, sizeof(u_int));
#endif
}

looutput(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;

	if ((m->m_flags & M_PKTHDR) == 0)
		panic("looutput no HDR");
	ifp->if_lastchange = time;
#if NBPFILTER > 0
	if (loif.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 *)⁡

		bpf_mtap(loif.if_bpf, &m0);
	}
#endif
	m->m_pkthdr.rcvif = ifp;

	if (rt && rt->rt_flags & RTF_REJECT) {
		m_freem(m);
		return (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:
		printf("lo%d: can't handle af%d\n", ifp->if_unit,
			dst->sa_family);
		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
lortrequest(cmd, rt, sa)
	int cmd;
	struct rtentry *rt;
	struct sockaddr *sa;
{

	if (rt)
		rt->rt_rmx.rmx_mtu = LOMTU;
}

/*
 * Process an ioctl request.
 */
/* ARGSUSED */
loioctl(ifp, cmd, data)
	register struct ifnet *ifp;
	int cmd;
	caddr_t data;
{
	register struct ifaddr *ifa;
#ifdef MULTICAST
	register struct ifreq *ifr;
#endif
	register int error = 0;

	switch (cmd) {

	case SIOCSIFADDR:
		ifp->if_flags |= IFF_UP;
		ifa = (struct ifaddr *)data;
		if (ifa != 0 && ifa->ifa_addr->sa_family == AF_ISO)
			ifa->ifa_rtrequest = lortrequest;
		/*
		 * Everything else is done at a higher level.
		 */
		break;

#ifdef MULTICAST
	case SIOCADDMULTI:
	case SIOCDELMULTI:
		ifr = (struct ifreq *)data;
		if (ifr == 0) {
			error = EAFNOSUPPORT;		/* XXX */
			break;
		}
		switch (ifr->ifr_addr.sa_family) {

#ifdef INET
		case AF_INET:
			break;
#endif

		default:
			error = EAFNOSUPPORT;
			break;
		}
		break;
#endif

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