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_var.h> 49 #include <net/if_clone.h> 50 #include <net/if_types.h> 51 #include <net/route.h> 52 #include <net/route_internal.h> 53 #include <net/bpf.h> 54 #include <net/vnet.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 struct disc_softc { 66 struct ifnet *sc_ifp; 67 }; 68 69 static int discoutput(struct ifnet *, struct mbuf *, 70 const struct sockaddr *, struct nhop_info *); 71 static int discioctl(struct ifnet *, u_long, caddr_t); 72 static int disc_clone_create(struct if_clone *, int, caddr_t); 73 static void disc_clone_destroy(struct ifnet *); 74 75 static const char discname[] = "disc"; 76 static MALLOC_DEFINE(M_DISC, discname, "Discard interface"); 77 78 static VNET_DEFINE(struct if_clone *, disc_cloner); 79 #define V_disc_cloner VNET(disc_cloner) 80 81 static int 82 disc_clone_create(struct if_clone *ifc, int unit, caddr_t params) 83 { 84 struct ifnet *ifp; 85 struct disc_softc *sc; 86 87 sc = malloc(sizeof(struct disc_softc), M_DISC, M_WAITOK | M_ZERO); 88 ifp = sc->sc_ifp = if_alloc(IFT_LOOP); 89 if (ifp == NULL) { 90 free(sc, M_DISC); 91 return (ENOSPC); 92 } 93 94 ifp->if_softc = sc; 95 if_initname(ifp, discname, unit); 96 ifp->if_mtu = DSMTU; 97 /* 98 * IFF_LOOPBACK should not be removed from disc's flags because 99 * it controls what PF-specific routes are magically added when 100 * a network address is assigned to the interface. Things just 101 * won't work as intended w/o such routes because the output 102 * interface selection for a packet is totally route-driven. 103 * A valid alternative to IFF_LOOPBACK can be IFF_BROADCAST or 104 * IFF_POINTOPOINT, but it would result in different properties 105 * of the interface. 106 */ 107 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 108 ifp->if_drv_flags = IFF_DRV_RUNNING; 109 ifp->if_ioctl = discioctl; 110 ifp->if_output = discoutput; 111 ifp->if_hdrlen = 0; 112 ifp->if_addrlen = 0; 113 ifp->if_snd.ifq_maxlen = 20; 114 if_attach(ifp); 115 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 116 117 return (0); 118 } 119 120 static void 121 disc_clone_destroy(struct ifnet *ifp) 122 { 123 struct disc_softc *sc; 124 125 sc = ifp->if_softc; 126 127 bpfdetach(ifp); 128 if_detach(ifp); 129 if_free(ifp); 130 131 free(sc, M_DISC); 132 } 133 134 static void 135 vnet_disc_init(const void *unused __unused) 136 { 137 138 V_disc_cloner = if_clone_simple(discname, disc_clone_create, 139 disc_clone_destroy, 0); 140 } 141 VNET_SYSINIT(vnet_disc_init, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY, 142 vnet_disc_init, NULL); 143 144 static void 145 vnet_disc_uninit(const void *unused __unused) 146 { 147 148 if_clone_detach(V_disc_cloner); 149 } 150 VNET_SYSUNINIT(vnet_disc_uninit, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY, 151 vnet_disc_uninit, NULL); 152 153 static int 154 disc_modevent(module_t mod, int type, void *data) 155 { 156 157 switch (type) { 158 case MOD_LOAD: 159 case MOD_UNLOAD: 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, const struct sockaddr *dst, 177 struct nhop_info *ni) 178 { 179 u_int32_t af; 180 181 M_ASSERTPKTHDR(m); 182 183 /* BPF writes need to be handled specially. */ 184 if (dst->sa_family == AF_UNSPEC) 185 bcopy(dst->sa_data, &af, sizeof(af)); 186 else 187 af = dst->sa_family; 188 189 if (bpf_peers_present(ifp->if_bpf)) 190 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 191 192 m->m_pkthdr.rcvif = ifp; 193 194 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); 195 if_inc_counter(ifp, IFCOUNTER_OBYTES, m->m_pkthdr.len); 196 197 m_freem(m); 198 return (0); 199 } 200 201 /* 202 * Process an ioctl request. 203 */ 204 static int 205 discioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 206 { 207 struct ifreq *ifr = (struct ifreq *)data; 208 int error = 0; 209 210 switch (cmd) { 211 case SIOCSIFADDR: 212 ifp->if_flags |= IFF_UP; 213 214 /* 215 * Everything else is done at a higher level. 216 */ 217 break; 218 case SIOCADDMULTI: 219 case SIOCDELMULTI: 220 if (ifr == 0) { 221 error = EAFNOSUPPORT; /* XXX */ 222 break; 223 } 224 switch (ifr->ifr_addr.sa_family) { 225 #ifdef INET 226 case AF_INET: 227 break; 228 #endif 229 #ifdef INET6 230 case AF_INET6: 231 break; 232 #endif 233 default: 234 error = EAFNOSUPPORT; 235 break; 236 } 237 break; 238 case SIOCSIFMTU: 239 ifp->if_mtu = ifr->ifr_mtu; 240 break; 241 default: 242 error = EINVAL; 243 } 244 return (error); 245 } 246