if_disc.c revision 131669
1/* 2 * Copyright (c) 1982, 1986, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * From: @(#)if_loop.c 8.1 (Berkeley) 6/10/93 30 * $FreeBSD: head/sys/net/if_disc.c 131669 2004-07-06 03:07:50Z bms $ 31 */ 32 33/* 34 * Discard interface driver for protocol testing and timing. 35 * (Based on the loopback.) 36 */ 37 38#include <sys/param.h> 39#include <sys/systm.h> 40#include <sys/kernel.h> 41#include <sys/malloc.h> 42#include <sys/module.h> 43#include <sys/mbuf.h> 44#include <sys/socket.h> 45#include <sys/sockio.h> 46 47#include <net/if.h> 48#include <net/if_clone.h> 49#include <net/if_types.h> 50#include <net/route.h> 51#include <net/bpf.h> 52 53#include "opt_inet.h" 54#include "opt_inet6.h" 55 56#ifdef TINY_DSMTU 57#define DSMTU (1024+512) 58#else 59#define DSMTU 65532 60#endif 61 62#define DISCNAME "disc" 63 64struct disc_softc { 65 struct ifnet sc_if; /* must be first */ 66 LIST_ENTRY(disc_softc) sc_list; 67}; 68 69static int discoutput(struct ifnet *, struct mbuf *, 70 struct sockaddr *, struct rtentry *); 71static void discrtrequest(int, struct rtentry *, struct rt_addrinfo *); 72static int discioctl(struct ifnet *, u_long, caddr_t); 73static int disc_clone_create(struct if_clone *, int); 74static void disc_clone_destroy(struct ifnet *); 75 76static struct mtx disc_mtx; 77static MALLOC_DEFINE(M_DISC, DISCNAME, "Discard interface"); 78static LIST_HEAD(, disc_softc) disc_softc_list; 79 80IFC_SIMPLE_DECLARE(disc, 0); 81 82static int 83disc_clone_create(struct if_clone *ifc, int unit) 84{ 85 struct ifnet *ifp; 86 struct disc_softc *sc; 87 88 sc = malloc(sizeof(struct disc_softc), M_DISC, M_WAITOK); 89 bzero(sc, sizeof(struct disc_softc)); 90 91 ifp = &sc->sc_if; 92 93 ifp->if_softc = sc; 94 if_initname(ifp, ifc->ifc_name, unit); 95 ifp->if_mtu = DSMTU; 96 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 97 ifp->if_ioctl = discioctl; 98 ifp->if_output = discoutput; 99 ifp->if_type = IFT_LOOP; 100 ifp->if_hdrlen = 0; 101 ifp->if_addrlen = 0; 102 ifp->if_snd.ifq_maxlen = 20; 103 if_attach(ifp); 104 bpfattach(ifp, DLT_NULL, sizeof(u_int)); 105 mtx_lock(&disc_mtx); 106 LIST_INSERT_HEAD(&disc_softc_list, sc, sc_list); 107 mtx_unlock(&disc_mtx); 108 109 return (0); 110} 111 112static void 113disc_destroy(struct disc_softc *sc) 114{ 115 116 bpfdetach(&sc->sc_if); 117 if_detach(&sc->sc_if); 118 119 free(sc, M_DISC); 120} 121 122static void 123disc_clone_destroy(struct ifnet *ifp) 124{ 125 struct disc_softc *sc; 126 127 sc = ifp->if_softc; 128 mtx_lock(&disc_mtx); 129 LIST_REMOVE(sc, sc_list); 130 mtx_unlock(&disc_mtx); 131 132 disc_destroy(sc); 133} 134 135static int 136disc_modevent(module_t mod, int type, void *data) 137{ 138 struct disc_softc *sc; 139 140 switch (type) { 141 case MOD_LOAD: 142 mtx_init(&disc_mtx, "disc_mtx", NULL, MTX_DEF); 143 LIST_INIT(&disc_softc_list); 144 if_clone_attach(&disc_cloner); 145 break; 146 case MOD_UNLOAD: 147 if_clone_detach(&disc_cloner); 148 149 mtx_lock(&disc_mtx); 150 while ((sc = LIST_FIRST(&disc_softc_list)) != NULL) { 151 LIST_REMOVE(sc, sc_list); 152 mtx_unlock(&disc_mtx); 153 disc_destroy(sc); 154 mtx_lock(&disc_mtx); 155 } 156 mtx_unlock(&disc_mtx); 157 mtx_destroy(&disc_mtx); 158 break; 159 } 160 return (0); 161} 162 163static moduledata_t disc_mod = { 164 "if_disc", 165 disc_modevent, 166 NULL 167}; 168 169DECLARE_MODULE(if_disc, disc_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 170 171static int 172discoutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 173 struct rtentry *rt) 174{ 175 176 M_ASSERTPKTHDR(m); 177 178 /* BPF write needs to be handled specially */ 179 if (dst->sa_family == AF_UNSPEC) { 180 dst->sa_family = *(mtod(m, int *)); 181 m->m_len -= sizeof(int); 182 m->m_pkthdr.len -= sizeof(int); 183 m->m_data += sizeof(int); 184 } 185 186 if (ifp->if_bpf) { 187 u_int af = dst->sa_family; 188 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 189 } 190 m->m_pkthdr.rcvif = ifp; 191 192 ifp->if_opackets++; 193 ifp->if_obytes += m->m_pkthdr.len; 194 195 m_freem(m); 196 return (0); 197} 198 199/* ARGSUSED */ 200static void 201discrtrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info) 202{ 203 RT_LOCK_ASSERT(rt); 204 205 if (rt) 206 rt->rt_rmx.rmx_mtu = DSMTU; 207} 208 209/* 210 * Process an ioctl request. 211 */ 212static int 213discioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 214{ 215 struct ifaddr *ifa; 216 struct ifreq *ifr = (struct ifreq *)data; 217 int error = 0; 218 219 switch (cmd) { 220 221 case SIOCSIFADDR: 222 ifp->if_flags |= IFF_UP; 223 ifa = (struct ifaddr *)data; 224 if (ifa != 0) 225 ifa->ifa_rtrequest = discrtrequest; 226 /* 227 * Everything else is done at a higher level. 228 */ 229 break; 230 231 case SIOCADDMULTI: 232 case SIOCDELMULTI: 233 if (ifr == 0) { 234 error = EAFNOSUPPORT; /* XXX */ 235 break; 236 } 237 switch (ifr->ifr_addr.sa_family) { 238 239#ifdef INET 240 case AF_INET: 241 break; 242#endif 243#ifdef INET6 244 case AF_INET6: 245 break; 246#endif 247 248 default: 249 error = EAFNOSUPPORT; 250 break; 251 } 252 break; 253 254 case SIOCSIFMTU: 255 ifp->if_mtu = ifr->ifr_mtu; 256 break; 257 258 default: 259 error = EINVAL; 260 } 261 return (error); 262} 263