Source to 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.
*
* @(#)if_loop.c 7.13 (Berkeley) 4/26/91
*/
/*
* 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);
}
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");
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);
}