2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1982, 1986, 1993
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8 * modification, are permitted provided that the following conditions
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19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * Discard interface driver for protocol testing and timing.
34 * (Based on the loopback.)
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/kernel.h>
40 #include <sys/malloc.h>
41 #include <sys/module.h>
43 #include <sys/socket.h>
44 #include <sys/sockio.h>
47 #include <net/if_var.h>
48 #include <net/if_private.h>
49 #include <net/if_clone.h>
50 #include <net/if_types.h>
51 #include <net/route.h>
56 #include "opt_inet6.h"
59 #define DSMTU (1024+512)
68 static int discoutput(struct ifnet *, struct mbuf *,
69 const struct sockaddr *, struct route *);
70 static int discioctl(struct ifnet *, u_long, caddr_t);
71 static int disc_clone_create(struct if_clone *, int, caddr_t);
72 static void disc_clone_destroy(struct ifnet *);
74 static const char discname[] = "disc";
75 static MALLOC_DEFINE(M_DISC, discname, "Discard interface");
77 VNET_DEFINE_STATIC(struct if_clone *, disc_cloner);
78 #define V_disc_cloner VNET(disc_cloner)
81 disc_clone_create(struct if_clone *ifc, int unit, caddr_t params)
84 struct disc_softc *sc;
86 sc = malloc(sizeof(struct disc_softc), M_DISC, M_WAITOK | M_ZERO);
87 ifp = sc->sc_ifp = if_alloc(IFT_LOOP);
94 if_initname(ifp, discname, unit);
97 * IFF_LOOPBACK should not be removed from disc's flags because
98 * it controls what PF-specific routes are magically added when
99 * a network address is assigned to the interface. Things just
100 * won't work as intended w/o such routes because the output
101 * interface selection for a packet is totally route-driven.
102 * A valid alternative to IFF_LOOPBACK can be IFF_BROADCAST or
103 * IFF_POINTOPOINT, but it would result in different properties
106 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
107 ifp->if_drv_flags = IFF_DRV_RUNNING;
108 ifp->if_ioctl = discioctl;
109 ifp->if_output = discoutput;
112 ifp->if_snd.ifq_maxlen = 20;
114 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
120 disc_clone_destroy(struct ifnet *ifp)
122 struct disc_softc *sc;
134 vnet_disc_init(const void *unused __unused)
137 V_disc_cloner = if_clone_simple(discname, disc_clone_create,
138 disc_clone_destroy, 0);
140 VNET_SYSINIT(vnet_disc_init, SI_SUB_PSEUDO, SI_ORDER_ANY,
141 vnet_disc_init, NULL);
144 vnet_disc_uninit(const void *unused __unused)
147 if_clone_detach(V_disc_cloner);
149 VNET_SYSUNINIT(vnet_disc_uninit, SI_SUB_INIT_IF, SI_ORDER_ANY,
150 vnet_disc_uninit, NULL);
153 disc_modevent(module_t mod, int type, void *data)
166 static moduledata_t disc_mod = {
172 DECLARE_MODULE(if_disc, disc_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
175 discoutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
182 /* BPF writes need to be handled specially. */
183 if (dst->sa_family == AF_UNSPEC)
184 bcopy(dst->sa_data, &af, sizeof(af));
186 af = RO_GET_FAMILY(ro, dst);
188 if (bpf_peers_present(ifp->if_bpf))
189 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
191 m->m_pkthdr.rcvif = ifp;
193 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
194 if_inc_counter(ifp, IFCOUNTER_OBYTES, m->m_pkthdr.len);
201 * Process an ioctl request.
204 discioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
206 struct ifreq *ifr = (struct ifreq *)data;
211 ifp->if_flags |= IFF_UP;
214 * Everything else is done at a higher level.
220 error = EAFNOSUPPORT; /* XXX */
223 switch (ifr->ifr_addr.sa_family) {
233 error = EAFNOSUPPORT;
238 ifp->if_mtu = ifr->ifr_mtu;