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_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 64 struct disc_softc { 65 struct ifnet sc_if; /* must be first */ 66 LIST_ENTRY(disc_softc) sc_list; 67 }; 68 69 static int discoutput(struct ifnet *, struct mbuf *, 70 struct sockaddr *, struct rtentry *); 71 static void discrtrequest(int, struct rtentry *, struct rt_addrinfo *); 72 static int discioctl(struct ifnet *, u_long, caddr_t); 73 static int disc_clone_create(struct if_clone *, int); 74 static void disc_clone_destroy(struct ifnet *); 75 76 static struct mtx disc_mtx; 77 static MALLOC_DEFINE(M_DISC, DISCNAME, "Discard interface"); 78 static LIST_HEAD(, disc_softc) disc_softc_list; 79 80 IFC_SIMPLE_DECLARE(disc, 0); 81 82 static int 83 disc_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 } 110 111 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 default: 159 return (EOPNOTSUPP); 160 } 161 return (0); 162 } 163 164 static moduledata_t disc_mod = { 165 "if_disc", 166 disc_modevent, 167 NULL 168 }; 169 170 DECLARE_MODULE(if_disc, disc_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 171 172 static int 173 discoutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 174 struct rtentry *rt) 175 { 176 177 M_ASSERTPKTHDR(m); 178 179 /* BPF write needs to be handled specially */ 180 if (dst->sa_family == AF_UNSPEC) { 181 dst->sa_family = *(mtod(m, int *)); 182 m->m_len -= sizeof(int); 183 m->m_pkthdr.len -= sizeof(int); 184 m->m_data += sizeof(int); 185 } 186 187 if (ifp->if_bpf) { 188 u_int af = dst->sa_family; 189 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 190 } 191 m->m_pkthdr.rcvif = ifp; 192 193 ifp->if_opackets++; 194 ifp->if_obytes += m->m_pkthdr.len; 195 196 m_freem(m); 197 return (0); 198 } 199 200 /* ARGSUSED */ 201 static void 202 discrtrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info) 203 { 204 RT_LOCK_ASSERT(rt); 205 206 if (rt) 207 rt->rt_rmx.rmx_mtu = DSMTU; 208 } 209 210 /* 211 * Process an ioctl request. 212 */ 213 static int 214 discioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 215 { 216 struct ifaddr *ifa; 217 struct ifreq *ifr = (struct ifreq *)data; 218 int error = 0; 219 220 switch (cmd) { 221 222 case SIOCSIFADDR: 223 ifp->if_flags |= IFF_UP; 224 ifa = (struct ifaddr *)data; 225 if (ifa != 0) 226 ifa->ifa_rtrequest = discrtrequest; 227 /* 228 * Everything else is done at a higher level. 229 */ 230 break; 231 232 case SIOCADDMULTI: 233 case SIOCDELMULTI: 234 if (ifr == 0) { 235 error = EAFNOSUPPORT; /* XXX */ 236 break; 237 } 238 switch (ifr->ifr_addr.sa_family) { 239 240 #ifdef INET 241 case AF_INET: 242 break; 243 #endif 244 #ifdef INET6 245 case AF_INET6: 246 break; 247 #endif 248 249 default: 250 error = EAFNOSUPPORT; 251 break; 252 } 253 break; 254 255 case SIOCSIFMTU: 256 ifp->if_mtu = ifr->ifr_mtu; 257 break; 258 259 default: 260 error = EINVAL; 261 } 262 return (error); 263 } 264