freebsd-dev/sys/net/if_loop.c
2001-12-14 19:32:47 +00:00

463 lines
10 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 8.2 (Berkeley) 1/9/95
* $FreeBSD$
*/
/*
* Loopback interface driver for protocol testing and timing.
*/
#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/malloc.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/if_types.h>
#include <net/netisr.h>
#include <net/route.h>
#include <net/bpf.h>
#include <net/bpfdesc.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 INET6
#ifndef INET
#include <netinet/in.h>
#endif
#include <netinet6/in6_var.h>
#include <netinet/ip6.h>
#endif
#ifdef NS
#include <netns/ns.h>
#include <netns/ns_if.h>
#endif
#ifdef NETATALK
#include <netatalk/at.h>
#include <netatalk/at_var.h>
#endif
int loioctl __P((struct ifnet *, u_long, caddr_t));
static void lortrequest __P((int, struct rtentry *, struct rt_addrinfo *));
int looutput __P((struct ifnet *ifp,
struct mbuf *m, struct sockaddr *dst, struct rtentry *rt));
#ifdef TINY_LOMTU
#define LOMTU (1024+512)
#elif defined(LARGE_LOMTU)
#define LOMTU 131072
#else
#define LOMTU 16384
#endif
static int nloop = 1;
struct ifnet *loif; /* Used externally */
static MALLOC_DEFINE(M_LO, "lo", "Loopback Interface");
struct lo_softc {
struct ifnet sc_if; /* network-visible interface */
LIST_ENTRY(lo_softc) sc_next;
};
static LIST_HEAD(lo_list, lo_softc) lo_list;
static void
locreate(int unit)
{
struct lo_softc *sc;
MALLOC(sc, struct lo_softc *, sizeof(*sc), M_LO, M_WAITOK | M_ZERO);
sc->sc_if.if_name = "lo";
sc->sc_if.if_unit = unit;
sc->sc_if.if_mtu = LOMTU;
sc->sc_if.if_flags = IFF_LOOPBACK | IFF_MULTICAST;
sc->sc_if.if_ioctl = loioctl;
sc->sc_if.if_output = looutput;
sc->sc_if.if_type = IFT_LOOP;
sc->sc_if.if_snd.ifq_maxlen = ifqmaxlen;
if_attach(&sc->sc_if);
bpfattach(&sc->sc_if, DLT_NULL, sizeof(u_int));
LIST_INSERT_HEAD(&lo_list, sc, sc_next);
if (loif == NULL)
loif = &sc->sc_if;
}
static void
lodestroy(struct lo_softc *sc)
{
bpfdetach(&sc->sc_if);
if_detach(&sc->sc_if);
LIST_REMOVE(sc, sc_next);
FREE(sc, M_LO);
}
static int
sysctl_net_nloop(SYSCTL_HANDLER_ARGS)
{
int newnloop;
int error;
newnloop = nloop;
error = sysctl_handle_opaque(oidp, &newnloop, sizeof newnloop, req);
if (error || !req->newptr)
return (error);
if (newnloop < 1)
return (EINVAL);
while (newnloop > nloop) {
locreate(nloop);
nloop++;
}
while (newnloop < nloop) {
lodestroy(LIST_FIRST(&lo_list));
nloop--;
}
return (0);
}
SYSCTL_PROC(_net, OID_AUTO, nloop, CTLTYPE_INT | CTLFLAG_RW,
0, 0, sysctl_net_nloop, "I", "");
static int
loop_modevent(module_t mod, int type, void *data)
{
int i;
switch (type) {
case MOD_LOAD:
TUNABLE_INT_FETCH("net.nloop", &nloop);
if (nloop < 1) /* sanity check */
nloop = 1;
for (i = 0; i < nloop; i++)
locreate(i);
break;
case MOD_UNLOAD:
printf("loop module unload - not possible for this module type\n");
return EINVAL;
}
return 0;
}
static moduledata_t loop_mod = {
"loop",
loop_modevent,
0
};
DECLARE_MODULE(loop, loop_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
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);
}
/*
* KAME requires that the packet to be contiguous on the
* mbuf. We need to make that sure.
* this kind of code should be avoided.
* XXX: fails to join if interface MTU > MCLBYTES. jumbogram?
*/
if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) {
struct mbuf *n;
MGETHDR(n, M_DONTWAIT, MT_HEADER);
if (!n)
goto contiguousfail;
MCLGET(n, M_DONTWAIT);
if (! (n->m_flags & M_EXT)) {
m_freem(n);
goto contiguousfail;
}
m_copydata(m, 0, m->m_pkthdr.len, mtod(n, caddr_t));
n->m_pkthdr = m->m_pkthdr;
n->m_len = m->m_pkthdr.len;
n->m_pkthdr.aux = m->m_pkthdr.aux;
m->m_pkthdr.aux = (struct mbuf *)NULL;
m_freem(m);
m = n;
}
if (0) {
contiguousfail:
printf("looutput: mbuf allocation failed\n");
}
ifp->if_opackets++;
ifp->if_obytes += m->m_pkthdr.len;
#if 1 /* XXX */
switch (dst->sa_family) {
case AF_INET:
case AF_INET6:
case AF_IPX:
case AF_NS:
case AF_APPLETALK:
break;
default:
printf("looutput: af=%d unexpected\n", dst->sa_family);
m_freem(m);
return (EAFNOSUPPORT);
}
#endif
return(if_simloop(ifp, m, dst->sa_family, 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, af, hlen)
struct ifnet *ifp;
struct mbuf *m;
int af;
int hlen;
{
int isr;
struct ifqueue *inq = 0;
KASSERT((m->m_flags & M_PKTHDR) != 0, ("if_simloop: no HDR"));
m->m_pkthdr.rcvif = ifp;
/* BPF write needs to be handled specially */
if (af == AF_UNSPEC) {
KASSERT(m->m_len >= sizeof(int), ("if_simloop: m_len"));
af = *(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) {
struct mbuf m0, *n = m;
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);
}
/* Strip away media header */
if (hlen > 0) {
m_adj(m, hlen);
#if defined(__alpha__) || defined(__ia64__)
/* The alpha doesn't like unaligned data.
* We move data down in the first mbuf */
if (mtod(m, vm_offset_t) & 3) {
KASSERT(hlen >= 3, ("if_simloop: hlen too small"));
bcopy(m->m_data,
(char *)(mtod(m, vm_offset_t)
- (mtod(m, vm_offset_t) & 3)),
m->m_len);
mtod(m,vm_offset_t) -= (mtod(m, vm_offset_t) & 3);
}
#endif
}
/* Deliver to upper layer protocol */
switch (af) {
#ifdef INET
case AF_INET:
inq = &ipintrq;
isr = NETISR_IP;
break;
#endif
#ifdef INET6
case AF_INET6:
m->m_flags |= M_LOOP;
inq = &ip6intrq;
isr = NETISR_IPV6;
break;
#endif
#ifdef IPX
case AF_IPX:
inq = &ipxintrq;
isr = NETISR_IPX;
break;
#endif
#ifdef NS
case AF_NS:
inq = &nsintrq;
isr = NETISR_NS;
break;
#endif
#ifdef NETATALK
case AF_APPLETALK:
inq = &atintrq2;
isr = NETISR_ATALK;
break;
#endif
default:
printf("if_simloop: can't handle af=%d\n", af);
m_freem(m);
return (EAFNOSUPPORT);
}
ifp->if_ipackets++;
ifp->if_ibytes += m->m_pkthdr.len;
(void) IF_HANDOFF(inq, m, NULL);
schednetisr(isr);
return (0);
}
/* ARGSUSED */
static void
lortrequest(cmd, rt, info)
int cmd;
struct rtentry *rt;
struct rt_addrinfo *info;
{
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 */
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
#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);
}