freebsd-nq/sys/net/if_loop.c

360 lines
8.0 KiB
C

/*
* 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.
* 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 8.1 (Berkeley) 6/10/93
* $Id: if_loop.c,v 1.36 1998/06/14 23:53:43 julian Exp $
*/
/*
* Loopback interface driver for protocol testing and timing.
*/
#include "loop.h"
#if NLOOP > 0
#include "opt_atalk.h"
#include "opt_inet.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 <sys/sockio.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_var.h>
#endif
#ifdef IPX
#include <netipx/ipx.h>
#include <netipx/ipx_if.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
#ifdef NETATALK
#include <netatalk/at.h>
#include <netatalk/at_var.h>
#endif NETATALK
#include "bpfilter.h"
#if NBPFILTER > 0
#include <net/bpfdesc.h>
#endif
static int loioctl __P((struct ifnet *, u_long, caddr_t));
static void lortrequest __P((int, struct rtentry *, struct sockaddr *));
static void loopattach __P((void *));
PSEUDO_SET(loopattach, if_loop);
static int looutput __P((struct ifnet *ifp,
struct mbuf *m, struct sockaddr *dst, struct rtentry *rt));
#ifdef TINY_LOMTU
#define LOMTU (1024+512)
#else
#define LOMTU 16384
#endif
struct ifnet loif[NLOOP];
/* ARGSUSED */
static void
loopattach(dummy)
void *dummy;
{
register struct ifnet *ifp;
register int i = 0;
for (ifp = loif; i < NLOOP; ifp++) {
ifp->if_name = "lo";
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;
if_attach(ifp);
#if NBPFILTER > 0
bpfattach(ifp, DLT_NULL, sizeof(u_int));
#endif
}
}
static int
looutput(ifp, m, dst, rt)
struct ifnet *ifp;
register struct mbuf *m;
struct sockaddr *dst;
register struct rtentry *rt;
{
if ((m->m_flags & M_PKTHDR) == 0)
panic("looutput no HDR");
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;
#if 1 /* XXX */
switch (dst->sa_family) {
case AF_INET:
case AF_IPX:
case AF_NS:
case AF_ISO:
case AF_APPLETALK:
break;
default:
printf("looutput: af=%d unexpected", dst->sa_family);
m_freem(m);
return (EAFNOSUPPORT);
}
#endif
return(if_simloop(ifp, m, dst, 0));
}
/*
* if_simloop()
*
* This function is to support software emulation of hardware loopback,
* i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't
* hear their own broadcasts, we create a copy of the packet that we
* would normally receive via a hardware loopback.
*
* This function expects the packet to include the media header of length hlen.
*/
int
if_simloop(ifp, m, dst, hlen)
struct ifnet *ifp;
register struct mbuf *m;
struct sockaddr *dst;
int hlen;
{
int s, isr;
register struct ifqueue *ifq = 0;
if ((m->m_flags & M_PKTHDR) == 0)
panic("if_simloop: no HDR");
m->m_pkthdr.rcvif = ifp;
#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);
}
if (ifp->if_bpf) {
struct mbuf m0, *n = m;
u_int af = dst->sa_family;
if (ifp->if_bpf->bif_dlt == DLT_NULL) {
/*
* 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).
*/
m0.m_next = m;
m0.m_len = 4;
m0.m_data = (char *)&af;
n = &m0;
}
bpf_mtap(ifp, n);
}
#endif
/* Strip away media header */
if (hlen > 0) {
#ifdef __alpha__
/* The alpha doesn't like unaligned data.
* We move data down in the first mbuf */
if (hlen & 3) {
bcopy(m->m_data + hlen, m->m_data, m->m_len - hlen);
m->m_len -= hlen;
if (m->m_flags & M_PKTHDR)
m->m_pkthdr.len -= hlen;
} else
#endif
m_adj(m, hlen);
}
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 NS
case AF_NS:
ifq = &nsintrq;
isr = NETISR_NS;
break;
#endif
#ifdef ISO
case AF_ISO:
ifq = &clnlintrq;
isr = NETISR_ISO;
break;
#endif
#ifdef NETATALK
case AF_APPLETALK:
ifq = &atintrq2;
isr = NETISR_ATALK;
break;
#endif NETATALK
default:
printf("if_simloop: can't handle af=%d\n", 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 */
static void
lortrequest(cmd, rt, sa)
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 = 3 * LOMTU;
}
}
/*
* Process an ioctl request.
*/
/* ARGSUSED */
static int
loioctl(ifp, cmd, data)
register struct ifnet *ifp;
u_long 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
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 */