if_disc.c revision 111119
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: head/sys/net/if_disc.c 111119 2003-02-19 05:47:46Z imp $ 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 67struct disc_softc { 68 struct ifnet sc_if; /* must be first */ 69 LIST_ENTRY(disc_softc) sc_list; 70}; 71 72static int discoutput(struct ifnet *, struct mbuf *, 73 struct sockaddr *, struct rtentry *); 74static void discrtrequest(int, struct rtentry *, struct rt_addrinfo *); 75static int discioctl(struct ifnet *, u_long, caddr_t); 76static int disc_clone_create(struct if_clone *, int); 77static void disc_clone_destroy(struct ifnet *); 78 79static MALLOC_DEFINE(M_DISC, DISCNAME, "Discard interface"); 80static LIST_HEAD(, disc_softc) disc_softc_list; 81static struct if_clone disc_cloner = IF_CLONE_INITIALIZER(DISCNAME, 82 disc_clone_create, disc_clone_destroy, 0, IF_MAXUNIT); 83 84static int 85disc_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 ifp->if_name = DISCNAME; 97 ifp->if_unit = unit; 98 ifp->if_mtu = DSMTU; 99 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 100 ifp->if_ioctl = discioctl; 101 ifp->if_output = discoutput; 102 ifp->if_type = IFT_LOOP; 103 ifp->if_hdrlen = 0; 104 ifp->if_addrlen = 0; 105 ifp->if_snd.ifq_maxlen = 20; 106 if_attach(ifp); 107 bpfattach(ifp, DLT_NULL, sizeof(u_int)); 108 LIST_INSERT_HEAD(&disc_softc_list, sc, sc_list); 109 110 return (0); 111} 112 113static void 114disc_clone_destroy(struct ifnet *ifp) 115{ 116 struct disc_softc *sc; 117 118 sc = ifp->if_softc; 119 120 LIST_REMOVE(sc, sc_list); 121 bpfdetach(ifp); 122 if_detach(ifp); 123 124 free(sc, M_DISC); 125} 126 127static int 128disc_modevent(module_t mod, int type, void *data) 129{ 130 switch (type) { 131 case MOD_LOAD: 132 LIST_INIT(&disc_softc_list); 133 if_clone_attach(&disc_cloner); 134 break; 135 case MOD_UNLOAD: 136 if_clone_detach(&disc_cloner); 137 138 while (!LIST_EMPTY(&disc_softc_list)) 139 disc_clone_destroy( 140 &LIST_FIRST(&disc_softc_list)->sc_if); 141 break; 142 } 143 return 0; 144} 145 146static moduledata_t disc_mod = { 147 "if_disc", 148 disc_modevent, 149 NULL 150}; 151 152DECLARE_MODULE(if_disc, disc_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 153 154static int 155discoutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 156 struct rtentry *rt) 157{ 158 if ((m->m_flags & M_PKTHDR) == 0) 159 panic("discoutput no HDR"); 160 /* BPF write needs to be handled specially */ 161 if (dst->sa_family == AF_UNSPEC) { 162 dst->sa_family = *(mtod(m, int *)); 163 m->m_len -= sizeof(int); 164 m->m_pkthdr.len -= sizeof(int); 165 m->m_data += sizeof(int); 166 } 167 168 if (ifp->if_bpf) { 169 /* 170 * We need to prepend the address family as 171 * a four byte field. Cons up a dummy header 172 * to pacify bpf. This is safe because bpf 173 * will only read from the mbuf (i.e., it won't 174 * try to free it or keep a pointer a to it). 175 */ 176 struct mbuf m0; 177 u_int af = dst->sa_family; 178 179 m0.m_next = m; 180 m0.m_len = 4; 181 m0.m_data = (char *)⁡ 182 183 BPF_MTAP(ifp, &m0); 184 } 185 m->m_pkthdr.rcvif = ifp; 186 187 ifp->if_opackets++; 188 ifp->if_obytes += m->m_pkthdr.len; 189 190 m_freem(m); 191 return 0; 192} 193 194/* ARGSUSED */ 195static void 196discrtrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info) 197{ 198 if (rt) 199 rt->rt_rmx.rmx_mtu = DSMTU; 200} 201 202/* 203 * Process an ioctl request. 204 */ 205static int 206discioctl(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