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_ifp; /* 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 ifp = sc->sc_ifp = if_alloc(IFT_LOOP); 90 if (ifp == NULL) { 91 free(sc, M_DISC); 92 return (ENOSPC); 93 } 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_hdrlen = 0; 102 ifp->if_addrlen = 0; 103 ifp->if_snd.ifq_maxlen = 20; 104 if_attach(ifp); 105 bpfattach(ifp, DLT_NULL, sizeof(u_int)); 106 mtx_lock(&disc_mtx); 107 LIST_INSERT_HEAD(&disc_softc_list, sc, sc_list); 108 mtx_unlock(&disc_mtx); 109 110 return (0); 111 } 112 113 static void 114 disc_destroy(struct disc_softc *sc) 115 { 116 117 bpfdetach(sc->sc_ifp); 118 if_detach(sc->sc_ifp); 119 if_free(sc->sc_ifp); 120 121 free(sc, M_DISC); 122 } 123 124 static void 125 disc_clone_destroy(struct ifnet *ifp) 126 { 127 struct disc_softc *sc; 128 129 sc = ifp->if_softc; 130 mtx_lock(&disc_mtx); 131 LIST_REMOVE(sc, sc_list); 132 mtx_unlock(&disc_mtx); 133 134 disc_destroy(sc); 135 } 136 137 static int 138 disc_modevent(module_t mod, int type, void *data) 139 { 140 struct disc_softc *sc; 141 142 switch (type) { 143 case MOD_LOAD: 144 mtx_init(&disc_mtx, "disc_mtx", NULL, MTX_DEF); 145 LIST_INIT(&disc_softc_list); 146 if_clone_attach(&disc_cloner); 147 break; 148 case MOD_UNLOAD: 149 if_clone_detach(&disc_cloner); 150 151 mtx_lock(&disc_mtx); 152 while ((sc = LIST_FIRST(&disc_softc_list)) != NULL) { 153 LIST_REMOVE(sc, sc_list); 154 mtx_unlock(&disc_mtx); 155 disc_destroy(sc); 156 mtx_lock(&disc_mtx); 157 } 158 mtx_unlock(&disc_mtx); 159 mtx_destroy(&disc_mtx); 160 break; 161 default: 162 return (EOPNOTSUPP); 163 } 164 return (0); 165 } 166 167 static moduledata_t disc_mod = { 168 "if_disc", 169 disc_modevent, 170 NULL 171 }; 172 173 DECLARE_MODULE(if_disc, disc_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 174 175 static int 176 discoutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 177 struct rtentry *rt) 178 { 179 180 M_ASSERTPKTHDR(m); 181 182 /* BPF write needs to be handled specially */ 183 if (dst->sa_family == AF_UNSPEC) { 184 dst->sa_family = *(mtod(m, int *)); 185 m->m_len -= sizeof(int); 186 m->m_pkthdr.len -= sizeof(int); 187 m->m_data += sizeof(int); 188 } 189 190 if (ifp->if_bpf) { 191 u_int af = dst->sa_family; 192 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 193 } 194 m->m_pkthdr.rcvif = ifp; 195 196 ifp->if_opackets++; 197 ifp->if_obytes += m->m_pkthdr.len; 198 199 m_freem(m); 200 return (0); 201 } 202 203 /* ARGSUSED */ 204 static void 205 discrtrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info) 206 { 207 RT_LOCK_ASSERT(rt); 208 rt->rt_rmx.rmx_mtu = DSMTU; 209 } 210 211 /* 212 * Process an ioctl request. 213 */ 214 static int 215 discioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 216 { 217 struct ifaddr *ifa; 218 struct ifreq *ifr = (struct ifreq *)data; 219 int error = 0; 220 221 switch (cmd) { 222 223 case SIOCSIFADDR: 224 ifp->if_flags |= IFF_UP; 225 ifa = (struct ifaddr *)data; 226 if (ifa != 0) 227 ifa->ifa_rtrequest = discrtrequest; 228 /* 229 * Everything else is done at a higher level. 230 */ 231 break; 232 233 case SIOCADDMULTI: 234 case SIOCDELMULTI: 235 if (ifr == 0) { 236 error = EAFNOSUPPORT; /* XXX */ 237 break; 238 } 239 switch (ifr->ifr_addr.sa_family) { 240 241 #ifdef INET 242 case AF_INET: 243 break; 244 #endif 245 #ifdef INET6 246 case AF_INET6: 247 break; 248 #endif 249 250 default: 251 error = EAFNOSUPPORT; 252 break; 253 } 254 break; 255 256 case SIOCSIFMTU: 257 ifp->if_mtu = ifr->ifr_mtu; 258 break; 259 260 default: 261 error = EINVAL; 262 } 263 return (error); 264 } 265