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 * $FreeBSD$ 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_types.h> 49 #include <net/route.h> 50 #include <net/bpf.h> 51 52 #include "opt_inet.h" 53 #include "opt_inet6.h" 54 55 #ifdef TINY_DSMTU 56 #define DSMTU (1024+512) 57 #else 58 #define DSMTU 65532 59 #endif 60 61 #define DISCNAME "disc" 62 63 struct disc_softc { 64 struct ifnet sc_if; /* must be first */ 65 LIST_ENTRY(disc_softc) sc_list; 66 }; 67 68 static int discoutput(struct ifnet *, struct mbuf *, 69 struct sockaddr *, struct rtentry *); 70 static void discrtrequest(int, struct rtentry *, struct rt_addrinfo *); 71 static int discioctl(struct ifnet *, u_long, caddr_t); 72 static int disc_clone_create(struct if_clone *, int); 73 static void disc_clone_destroy(struct ifnet *); 74 75 static struct mtx disc_mtx; 76 static MALLOC_DEFINE(M_DISC, DISCNAME, "Discard interface"); 77 static LIST_HEAD(, disc_softc) disc_softc_list; 78 static struct if_clone disc_cloner = IF_CLONE_INITIALIZER(DISCNAME, 79 disc_clone_create, disc_clone_destroy, 0, IF_MAXUNIT); 80 81 static int 82 disc_clone_create(struct if_clone *ifc, int unit) 83 { 84 struct ifnet *ifp; 85 struct disc_softc *sc; 86 87 sc = malloc(sizeof(struct disc_softc), M_DISC, M_WAITOK); 88 bzero(sc, sizeof(struct disc_softc)); 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 } 110 111 static void 112 disc_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 } 120 121 static void 122 disc_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 } 133 134 static int 135 disc_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 } 161 162 static moduledata_t disc_mod = { 163 "if_disc", 164 disc_modevent, 165 NULL 166 }; 167 168 DECLARE_MODULE(if_disc, disc_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 169 170 static int 171 discoutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 172 struct rtentry *rt) 173 { 174 M_ASSERTPKTHDR(m); 175 /* BPF write needs to be handled specially */ 176 if (dst->sa_family == AF_UNSPEC) { 177 dst->sa_family = *(mtod(m, int *)); 178 m->m_len -= sizeof(int); 179 m->m_pkthdr.len -= sizeof(int); 180 m->m_data += sizeof(int); 181 } 182 183 if (ifp->if_bpf) { 184 u_int af = dst->sa_family; 185 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 186 } 187 m->m_pkthdr.rcvif = ifp; 188 189 ifp->if_opackets++; 190 ifp->if_obytes += m->m_pkthdr.len; 191 192 m_freem(m); 193 return 0; 194 } 195 196 /* ARGSUSED */ 197 static void 198 discrtrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info) 199 { 200 RT_LOCK_ASSERT(rt); 201 202 if (rt) 203 rt->rt_rmx.rmx_mtu = DSMTU; 204 } 205 206 /* 207 * Process an ioctl request. 208 */ 209 static int 210 discioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 211 { 212 struct ifaddr *ifa; 213 struct ifreq *ifr = (struct ifreq *)data; 214 int error = 0; 215 216 switch (cmd) { 217 218 case SIOCSIFADDR: 219 ifp->if_flags |= IFF_UP; 220 ifa = (struct ifaddr *)data; 221 if (ifa != 0) 222 ifa->ifa_rtrequest = discrtrequest; 223 /* 224 * Everything else is done at a higher level. 225 */ 226 break; 227 228 case SIOCADDMULTI: 229 case SIOCDELMULTI: 230 if (ifr == 0) { 231 error = EAFNOSUPPORT; /* XXX */ 232 break; 233 } 234 switch (ifr->ifr_addr.sa_family) { 235 236 #ifdef INET 237 case AF_INET: 238 break; 239 #endif 240 #ifdef INET6 241 case AF_INET6: 242 break; 243 #endif 244 245 default: 246 error = EAFNOSUPPORT; 247 break; 248 } 249 break; 250 251 case SIOCSIFMTU: 252 ifp->if_mtu = ifr->ifr_mtu; 253 break; 254 255 default: 256 error = EINVAL; 257 } 258 return (error); 259 } 260