if_disc.c revision 131670
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 131670 2004-07-06 03:16:55Z 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 | M_ZERO); 89 90 ifp = &sc->sc_if; 91 92 ifp->if_softc = sc; 93 if_initname(ifp, ifc->ifc_name, unit); 94 ifp->if_mtu = DSMTU; 95 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 96 ifp->if_ioctl = discioctl; 97 ifp->if_output = discoutput; 98 ifp->if_type = IFT_LOOP; 99 ifp->if_hdrlen = 0; 100 ifp->if_addrlen = 0; 101 ifp->if_snd.ifq_maxlen = 20; 102 if_attach(ifp); 103 bpfattach(ifp, DLT_NULL, sizeof(u_int)); 104 mtx_lock(&disc_mtx); 105 LIST_INSERT_HEAD(&disc_softc_list, sc, sc_list); 106 mtx_unlock(&disc_mtx); 107 108 return (0); 109} 110 111static void 112disc_destroy(struct disc_softc *sc) 113{ 114 115 bpfdetach(&sc->sc_if); 116 if_detach(&sc->sc_if); 117 118 free(sc, M_DISC); 119} 120 121static void 122disc_clone_destroy(struct ifnet *ifp) 123{ 124 struct disc_softc *sc; 125 126 sc = ifp->if_softc; 127 mtx_lock(&disc_mtx); 128 LIST_REMOVE(sc, sc_list); 129 mtx_unlock(&disc_mtx); 130 131 disc_destroy(sc); 132} 133 134static int 135disc_modevent(module_t mod, int type, void *data) 136{ 137 struct disc_softc *sc; 138 139 switch (type) { 140 case MOD_LOAD: 141 mtx_init(&disc_mtx, "disc_mtx", NULL, MTX_DEF); 142 LIST_INIT(&disc_softc_list); 143 if_clone_attach(&disc_cloner); 144 break; 145 case MOD_UNLOAD: 146 if_clone_detach(&disc_cloner); 147 148 mtx_lock(&disc_mtx); 149 while ((sc = LIST_FIRST(&disc_softc_list)) != NULL) { 150 LIST_REMOVE(sc, sc_list); 151 mtx_unlock(&disc_mtx); 152 disc_destroy(sc); 153 mtx_lock(&disc_mtx); 154 } 155 mtx_unlock(&disc_mtx); 156 mtx_destroy(&disc_mtx); 157 break; 158 } 159 return (0); 160} 161 162static moduledata_t disc_mod = { 163 "if_disc", 164 disc_modevent, 165 NULL 166}; 167 168DECLARE_MODULE(if_disc, disc_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 169 170static int 171discoutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 172 struct rtentry *rt) 173{ 174 175 M_ASSERTPKTHDR(m); 176 177 /* BPF write needs to be handled specially */ 178 if (dst->sa_family == AF_UNSPEC) { 179 dst->sa_family = *(mtod(m, int *)); 180 m->m_len -= sizeof(int); 181 m->m_pkthdr.len -= sizeof(int); 182 m->m_data += sizeof(int); 183 } 184 185 if (ifp->if_bpf) { 186 u_int af = dst->sa_family; 187 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 188 } 189 m->m_pkthdr.rcvif = ifp; 190 191 ifp->if_opackets++; 192 ifp->if_obytes += m->m_pkthdr.len; 193 194 m_freem(m); 195 return (0); 196} 197 198/* ARGSUSED */ 199static void 200discrtrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info) 201{ 202 RT_LOCK_ASSERT(rt); 203 204 if (rt) 205 rt->rt_rmx.rmx_mtu = DSMTU; 206} 207 208/* 209 * Process an ioctl request. 210 */ 211static int 212discioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 213{ 214 struct ifaddr *ifa; 215 struct ifreq *ifr = (struct ifreq *)data; 216 int error = 0; 217 218 switch (cmd) { 219 220 case SIOCSIFADDR: 221 ifp->if_flags |= IFF_UP; 222 ifa = (struct ifaddr *)data; 223 if (ifa != 0) 224 ifa->ifa_rtrequest = discrtrequest; 225 /* 226 * Everything else is done at a higher level. 227 */ 228 break; 229 230 case SIOCADDMULTI: 231 case SIOCDELMULTI: 232 if (ifr == 0) { 233 error = EAFNOSUPPORT; /* XXX */ 234 break; 235 } 236 switch (ifr->ifr_addr.sa_family) { 237 238#ifdef INET 239 case AF_INET: 240 break; 241#endif 242#ifdef INET6 243 case AF_INET6: 244 break; 245#endif 246 247 default: 248 error = EAFNOSUPPORT; 249 break; 250 } 251 break; 252 253 case SIOCSIFMTU: 254 ifp->if_mtu = ifr->ifr_mtu; 255 break; 256 257 default: 258 error = EINVAL; 259 } 260 return (error); 261} 262