source: rtems/cpukit/libnetworking/net/if_loop.c @ 787f51f

/*
 * Copyright (c) 1982, 1986, 1993
 *      The 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.
 * 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.
 *
 *      @(#)if_loop.c   8.2 (Berkeley) 1/9/95
 * $FreeBSD: src/sys/net/if_loop.c,v 1.104 2005/02/24 01:34:01 sam Exp $
 */


#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

/*
 * Loopback interface driver for protocol testing and timing.
 */
#include "loop.h"
#if NLOOP > 0

#include "opt_atalk.h"
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_ipx.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <errno.h>
#include <sys/sockio.h>
#include <sys/time.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 IPX
#include <netipx/ipx.h>
#include <netipx/ipx_if.h>
#endif

#ifdef INET6
#ifndef INET
#include <netinet/in.h>
#endif
#include <netinet6/in6_var.h>
#include <netinet/ip6.h>
#endif

#ifdef NETATALK
#include <netatalk/at.h>
#include <netatalk/at_var.h>
#endif

static int loioctl(struct ifnet *, ioctl_command_t, caddr_t);
static void lortrequest(int, struct rtentry *, struct sockaddr *);

#ifdef TINY_LOMTU
#define LOMTU   (1024+512)
#elif defined(LARGE_LOMTU)
#define LOMTU  131072
#else
#define LOMTU   16384
#endif

struct  ifnet loif[NLOOP];

void
rtems_bsdnet_initialize_loop(void)
{
        register struct ifnet *ifp;
        register int i = 0;

        for (ifp = loif; i < NLOOP; ifp++) {
            ifp->if_name = "lo";
            ifp->if_next = NULL;
            ifp->if_unit = i++;
            ifp->if_mtu = LOMTU;
            ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
            ifp->if_ioctl = loioctl;
            ifp->if_output = looutput;
            ifp->if_type = IFT_LOOP;
            ifp->if_hdrlen = 0;
            ifp->if_addrlen = 0;
            ifp->if_snd.ifq_maxlen = ifqmaxlen;
            if_attach(ifp);
#if NBPFILTER > 0
            bpfattach(ifp, DLT_NULL, sizeof(u_int));
#endif
        }
}

int
looutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
    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
        /* BPF write needs to be handled specially */
        if (dst->sa_family == AF_UNSPEC) {
                dst->sa_family = *(mtod(m, int *));
                m->m_len -= sizeof(int);
                m->m_pkthdr.len -= sizeof(int);
                m->m_data += sizeof(int);
        }

        /* Let BPF see incoming packet */
        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, &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 IPX
        case AF_IPX:
                ifq = &ipxintrq;
                isr = NETISR_IPX;
                break;
#endif
#ifdef NETATALK
        case AF_APPLETALK:
                ifq = &atintrq2;
                isr = NETISR_ATALK;
                break;
#endif /* NETATALK */
        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);
}

static void
lortrequest(int cmd, struct rtentry *rt, struct sockaddr *sa)
{
        if (rt) {
                rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; /* for ISO */
                /*
                 * For optimal performance, the send and receive buffers
                 * should be at least twice the MTU plus a little more for
                 * overhead.
                 */
                rt->rt_rmx.rmx_recvpipe = 
                        rt->rt_rmx.rmx_sendpipe = 3L * (long)LOMTU;
        }
}

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

        switch (cmd) {

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

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

#ifdef INET
                case AF_INET:
                        break;
#endif
#ifdef INET6
                case AF_INET6:
                        break;
#endif

                default:
                        error = EAFNOSUPPORT;
                        break;
                }
                break;

        case SIOCSIFMTU:
                ifp->if_mtu = ifr->ifr_mtu;
                break;

        case SIOCSIFFLAGS:
                break;

        default:
                error = EINVAL;
        }
        return (error);
}
#endif /* NLOOP > 0 */