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 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * From: @(#)if_loop.c 8.1 (Berkeley) 6/10/93 34 * $FreeBSD$ 35 */ 36 37 /* 38 * Discard interface driver for protocol testing and timing. 39 * (Based on the loopback.) 40 */ 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/kernel.h> 45 #include <sys/malloc.h> 46 #include <sys/module.h> 47 #include <sys/mbuf.h> 48 #include <sys/socket.h> 49 #include <sys/sockio.h> 50 51 #include <net/if.h> 52 #include <net/if_types.h> 53 #include <net/route.h> 54 #include <net/bpf.h> 55 56 #include "opt_inet.h" 57 #include "opt_inet6.h" 58 59 #ifdef TINY_DSMTU 60 #define DSMTU (1024+512) 61 #else 62 #define DSMTU 65532 63 #endif 64 65 #define DISCNAME "disc" 66 67 struct disc_softc { 68 struct ifnet sc_if; /* must be first */ 69 LIST_ENTRY(disc_softc) sc_list; 70 }; 71 72 static int discoutput(struct ifnet *, struct mbuf *, 73 struct sockaddr *, struct rtentry *); 74 static void discrtrequest(int, struct rtentry *, struct rt_addrinfo *); 75 static int discioctl(struct ifnet *, u_long, caddr_t); 76 static int disc_clone_create(struct if_clone *, int); 77 static void disc_clone_destroy(struct ifnet *); 78 79 static MALLOC_DEFINE(M_DISC, DISCNAME, "Discard interface"); 80 static LIST_HEAD(, disc_softc) disc_softc_list; 81 static struct if_clone disc_cloner = IF_CLONE_INITIALIZER(DISCNAME, 82 disc_clone_create, disc_clone_destroy, 0, IF_MAXUNIT); 83 84 static int 85 disc_clone_create(struct if_clone *ifc, int unit) 86 { 87 struct ifnet *ifp; 88 struct disc_softc *sc; 89 90 sc = malloc(sizeof(struct disc_softc), M_DISC, M_WAITOK); 91 bzero(sc, sizeof(struct disc_softc)); 92 93 ifp = &sc->sc_if; 94 95 ifp->if_softc = sc; 96 if_initname(ifp, ifc->ifc_name, unit); 97 ifp->if_mtu = DSMTU; 98 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 99 ifp->if_ioctl = discioctl; 100 ifp->if_output = discoutput; 101 ifp->if_type = IFT_LOOP; 102 ifp->if_hdrlen = 0; 103 ifp->if_addrlen = 0; 104 ifp->if_snd.ifq_maxlen = 20; 105 if_attach(ifp); 106 bpfattach(ifp, DLT_NULL, sizeof(u_int)); 107 LIST_INSERT_HEAD(&disc_softc_list, sc, sc_list); 108 109 return (0); 110 } 111 112 static void 113 disc_clone_destroy(struct ifnet *ifp) 114 { 115 struct disc_softc *sc; 116 117 sc = ifp->if_softc; 118 119 LIST_REMOVE(sc, sc_list); 120 bpfdetach(ifp); 121 if_detach(ifp); 122 123 free(sc, M_DISC); 124 } 125 126 static int 127 disc_modevent(module_t mod, int type, void *data) 128 { 129 switch (type) { 130 case MOD_LOAD: 131 LIST_INIT(&disc_softc_list); 132 if_clone_attach(&disc_cloner); 133 break; 134 case MOD_UNLOAD: 135 if_clone_detach(&disc_cloner); 136 137 while (!LIST_EMPTY(&disc_softc_list)) 138 disc_clone_destroy( 139 &LIST_FIRST(&disc_softc_list)->sc_if); 140 break; 141 } 142 return 0; 143 } 144 145 static moduledata_t disc_mod = { 146 "if_disc", 147 disc_modevent, 148 NULL 149 }; 150 151 DECLARE_MODULE(if_disc, disc_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 152 153 static int 154 discoutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 155 struct rtentry *rt) 156 { 157 M_ASSERTPKTHDR(m); 158 /* BPF write needs to be handled specially */ 159 if (dst->sa_family == AF_UNSPEC) { 160 dst->sa_family = *(mtod(m, int *)); 161 m->m_len -= sizeof(int); 162 m->m_pkthdr.len -= sizeof(int); 163 m->m_data += sizeof(int); 164 } 165 166 if (ifp->if_bpf) { 167 /* 168 * We need to prepend the address family as 169 * a four byte field. Cons up a dummy header 170 * to pacify bpf. This is safe because bpf 171 * will only read from the mbuf (i.e., it won't 172 * try to free it or keep a pointer a to it). 173 */ 174 struct mbuf m0; 175 u_int af = dst->sa_family; 176 177 m0.m_next = m; 178 m0.m_len = 4; 179 m0.m_data = (char *)⁡ 180 181 BPF_MTAP(ifp, &m0); 182 } 183 m->m_pkthdr.rcvif = ifp; 184 185 ifp->if_opackets++; 186 ifp->if_obytes += m->m_pkthdr.len; 187 188 m_freem(m); 189 return 0; 190 } 191 192 /* ARGSUSED */ 193 static void 194 discrtrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info) 195 { 196 RT_LOCK_ASSERT(rt); 197 198 if (rt) 199 rt->rt_rmx.rmx_mtu = DSMTU; 200 } 201 202 /* 203 * Process an ioctl request. 204 */ 205 static int 206 discioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 207 { 208 struct ifaddr *ifa; 209 struct ifreq *ifr = (struct ifreq *)data; 210 int error = 0; 211 212 switch (cmd) { 213 214 case SIOCSIFADDR: 215 ifp->if_flags |= IFF_UP; 216 ifa = (struct ifaddr *)data; 217 if (ifa != 0) 218 ifa->ifa_rtrequest = discrtrequest; 219 /* 220 * Everything else is done at a higher level. 221 */ 222 break; 223 224 case SIOCADDMULTI: 225 case SIOCDELMULTI: 226 if (ifr == 0) { 227 error = EAFNOSUPPORT; /* XXX */ 228 break; 229 } 230 switch (ifr->ifr_addr.sa_family) { 231 232 #ifdef INET 233 case AF_INET: 234 break; 235 #endif 236 #ifdef INET6 237 case AF_INET6: 238 break; 239 #endif 240 241 default: 242 error = EAFNOSUPPORT; 243 break; 244 } 245 break; 246 247 case SIOCSIFMTU: 248 ifp->if_mtu = ifr->ifr_mtu; 249 break; 250 251 default: 252 error = EINVAL; 253 } 254 return (error); 255 } 256