68b11e74f4
It should be the final follow-up to an old yet unfinished discussion on whether IFF_LOOPBACK is necessary for disc(4) and why.
246 lines
5.7 KiB
C
246 lines
5.7 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.
|
|
* 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 8.1 (Berkeley) 6/10/93
|
|
* $FreeBSD$
|
|
*/
|
|
|
|
/*
|
|
* Discard interface driver for protocol testing and timing.
|
|
* (Based on the loopback.)
|
|
*/
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/module.h>
|
|
#include <sys/mbuf.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/sockio.h>
|
|
|
|
#include <net/if.h>
|
|
#include <net/if_clone.h>
|
|
#include <net/if_types.h>
|
|
#include <net/route.h>
|
|
#include <net/bpf.h>
|
|
|
|
#include "opt_inet.h"
|
|
#include "opt_inet6.h"
|
|
|
|
#ifdef TINY_DSMTU
|
|
#define DSMTU (1024+512)
|
|
#else
|
|
#define DSMTU 65532
|
|
#endif
|
|
|
|
#define DISCNAME "disc"
|
|
|
|
struct disc_softc {
|
|
struct ifnet *sc_ifp;
|
|
};
|
|
|
|
static int discoutput(struct ifnet *, struct mbuf *,
|
|
struct sockaddr *, struct rtentry *);
|
|
static void discrtrequest(int, struct rtentry *, struct rt_addrinfo *);
|
|
static int discioctl(struct ifnet *, u_long, caddr_t);
|
|
static int disc_clone_create(struct if_clone *, int, caddr_t);
|
|
static void disc_clone_destroy(struct ifnet *);
|
|
|
|
static MALLOC_DEFINE(M_DISC, DISCNAME, "Discard interface");
|
|
|
|
IFC_SIMPLE_DECLARE(disc, 0);
|
|
|
|
static int
|
|
disc_clone_create(struct if_clone *ifc, int unit, caddr_t params)
|
|
{
|
|
struct ifnet *ifp;
|
|
struct disc_softc *sc;
|
|
|
|
sc = malloc(sizeof(struct disc_softc), M_DISC, M_WAITOK | M_ZERO);
|
|
ifp = sc->sc_ifp = if_alloc(IFT_LOOP);
|
|
if (ifp == NULL) {
|
|
free(sc, M_DISC);
|
|
return (ENOSPC);
|
|
}
|
|
|
|
ifp->if_softc = sc;
|
|
if_initname(ifp, ifc->ifc_name, unit);
|
|
ifp->if_mtu = DSMTU;
|
|
/*
|
|
* IFF_LOOPBACK should not be removed from disc's flags because
|
|
* it controls what PF-specific routes are magically added when
|
|
* a network address is assigned to the interface. Things just
|
|
* won't work as intended w/o such routes because the output
|
|
* interface selection for a packet is totally route-driven.
|
|
* A valid alternative to IFF_LOOPBACK can be IFF_BROADCAST or
|
|
* IFF_POINTOPOINT, but it would result in different properties
|
|
* of the interface.
|
|
*/
|
|
ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
|
|
ifp->if_drv_flags = IFF_DRV_RUNNING;
|
|
ifp->if_ioctl = discioctl;
|
|
ifp->if_output = discoutput;
|
|
ifp->if_hdrlen = 0;
|
|
ifp->if_addrlen = 0;
|
|
ifp->if_snd.ifq_maxlen = 20;
|
|
if_attach(ifp);
|
|
bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
|
|
|
|
return (0);
|
|
}
|
|
|
|
static void
|
|
disc_clone_destroy(struct ifnet *ifp)
|
|
{
|
|
struct disc_softc *sc;
|
|
|
|
sc = ifp->if_softc;
|
|
|
|
bpfdetach(ifp);
|
|
if_detach(ifp);
|
|
if_free(ifp);
|
|
|
|
free(sc, M_DISC);
|
|
}
|
|
|
|
static int
|
|
disc_modevent(module_t mod, int type, void *data)
|
|
{
|
|
|
|
switch (type) {
|
|
case MOD_LOAD:
|
|
if_clone_attach(&disc_cloner);
|
|
break;
|
|
case MOD_UNLOAD:
|
|
if_clone_detach(&disc_cloner);
|
|
break;
|
|
default:
|
|
return (EOPNOTSUPP);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
static moduledata_t disc_mod = {
|
|
"if_disc",
|
|
disc_modevent,
|
|
NULL
|
|
};
|
|
|
|
DECLARE_MODULE(if_disc, disc_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
|
|
|
|
static int
|
|
discoutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
|
|
struct rtentry *rt)
|
|
{
|
|
u_int32_t af;
|
|
|
|
M_ASSERTPKTHDR(m);
|
|
|
|
/* BPF writes need to be handled specially. */
|
|
if (dst->sa_family == AF_UNSPEC) {
|
|
bcopy(dst->sa_data, &af, sizeof(af));
|
|
dst->sa_family = af;
|
|
}
|
|
|
|
if (bpf_peers_present(ifp->if_bpf)) {
|
|
u_int af = dst->sa_family;
|
|
bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
|
|
}
|
|
m->m_pkthdr.rcvif = ifp;
|
|
|
|
ifp->if_opackets++;
|
|
ifp->if_obytes += m->m_pkthdr.len;
|
|
|
|
m_freem(m);
|
|
return (0);
|
|
}
|
|
|
|
/* ARGSUSED */
|
|
static void
|
|
discrtrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info)
|
|
{
|
|
RT_LOCK_ASSERT(rt);
|
|
rt->rt_rmx.rmx_mtu = DSMTU;
|
|
}
|
|
|
|
/*
|
|
* Process an ioctl request.
|
|
*/
|
|
static int
|
|
discioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
|
|
{
|
|
struct ifaddr *ifa;
|
|
struct ifreq *ifr = (struct ifreq *)data;
|
|
int error = 0;
|
|
|
|
switch (cmd) {
|
|
|
|
case SIOCSIFADDR:
|
|
ifp->if_flags |= IFF_UP;
|
|
ifa = (struct ifaddr *)data;
|
|
if (ifa != 0)
|
|
ifa->ifa_rtrequest = discrtrequest;
|
|
/*
|
|
* 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;
|
|
|
|
default:
|
|
error = EINVAL;
|
|
}
|
|
return (error);
|
|
}
|