sys/net/if_loop.c

/*
 * Copyright (c) 1982, 1986 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. 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 BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      from: @(#)if_loop.c     7.13 (Berkeley) 4/26/91
 *      $Id$
 */

/*
 * 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

#include "bpfilter.h"
#if NBPFILTER > 0
#include <sys/time.h>
#include <net/bpf.h>
static caddr_t lo_bpf;
#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);
#if NBPFILTER > 0
        bpfattach(&lo_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");
#if NBPFILTER > 0
        if (lo_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 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(lo_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 */
lortrequest(cmd, rt, sa)
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;
        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;

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