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 * @(#)if_loop.c 8.2 (Berkeley) 1/9/95 34 * $FreeBSD$ 35 */ 36 37 /* 38 * Loopback interface driver for protocol testing and timing. 39 */ 40 41 #include "opt_atalk.h" 42 #include "opt_inet.h" 43 #include "opt_inet6.h" 44 #include "opt_ipx.h" 45 #include "opt_mac.h" 46 47 #include <sys/param.h> 48 #include <sys/systm.h> 49 #include <sys/kernel.h> 50 #include <sys/mac.h> 51 #include <sys/malloc.h> 52 #include <sys/mbuf.h> 53 #include <sys/module.h> 54 #include <machine/bus.h> 55 #include <sys/rman.h> 56 #include <sys/socket.h> 57 #include <sys/sockio.h> 58 #include <sys/sysctl.h> 59 60 #include <net/if.h> 61 #include <net/if_types.h> 62 #include <net/netisr.h> 63 #include <net/route.h> 64 #include <net/bpf.h> 65 #include <net/bpfdesc.h> 66 67 #ifdef INET 68 #include <netinet/in.h> 69 #include <netinet/in_var.h> 70 #endif 71 72 #ifdef IPX 73 #include <netipx/ipx.h> 74 #include <netipx/ipx_if.h> 75 #endif 76 77 #ifdef INET6 78 #ifndef INET 79 #include <netinet/in.h> 80 #endif 81 #include <netinet6/in6_var.h> 82 #include <netinet/ip6.h> 83 #endif 84 85 #ifdef NETATALK 86 #include <netatalk/at.h> 87 #include <netatalk/at_var.h> 88 #endif 89 90 #ifdef TINY_LOMTU 91 #define LOMTU (1024+512) 92 #elif defined(LARGE_LOMTU) 93 #define LOMTU 131072 94 #else 95 #define LOMTU 16384 96 #endif 97 98 #define LONAME "lo" 99 100 struct lo_softc { 101 struct ifnet sc_if; /* network-visible interface */ 102 LIST_ENTRY(lo_softc) sc_next; 103 }; 104 105 int loioctl(struct ifnet *, u_long, caddr_t); 106 static void lortrequest(int, struct rtentry *, struct rt_addrinfo *); 107 int looutput(struct ifnet *ifp, struct mbuf *m, 108 struct sockaddr *dst, struct rtentry *rt); 109 int lo_clone_create(struct if_clone *, int); 110 void lo_clone_destroy(struct ifnet *); 111 112 struct ifnet *loif = NULL; /* Used externally */ 113 114 static MALLOC_DEFINE(M_LO, LONAME, "Loopback Interface"); 115 116 static struct mtx lo_mtx; 117 static LIST_HEAD(lo_list, lo_softc) lo_list; 118 119 struct if_clone lo_cloner = IF_CLONE_INITIALIZER(LONAME, 120 lo_clone_create, lo_clone_destroy, 1, IF_MAXUNIT); 121 122 void 123 lo_clone_destroy(ifp) 124 struct ifnet *ifp; 125 { 126 struct lo_softc *sc; 127 128 sc = ifp->if_softc; 129 130 /* XXX: destroying lo0 will lead to panics. */ 131 KASSERT(loif != ifp, ("%s: destroying lo0", __func__)); 132 133 mtx_lock(&lo_mtx); 134 LIST_REMOVE(sc, sc_next); 135 mtx_unlock(&lo_mtx); 136 bpfdetach(ifp); 137 if_detach(ifp); 138 free(sc, M_LO); 139 } 140 141 int 142 lo_clone_create(ifc, unit) 143 struct if_clone *ifc; 144 int unit; 145 { 146 struct lo_softc *sc; 147 148 MALLOC(sc, struct lo_softc *, sizeof(*sc), M_LO, M_WAITOK | M_ZERO); 149 150 if_initname(&sc->sc_if, ifc->ifc_name, unit); 151 sc->sc_if.if_mtu = LOMTU; 152 sc->sc_if.if_flags = IFF_LOOPBACK | IFF_MULTICAST; 153 sc->sc_if.if_ioctl = loioctl; 154 sc->sc_if.if_output = looutput; 155 sc->sc_if.if_type = IFT_LOOP; 156 sc->sc_if.if_snd.ifq_maxlen = ifqmaxlen; 157 sc->sc_if.if_softc = sc; 158 if_attach(&sc->sc_if); 159 bpfattach(&sc->sc_if, DLT_NULL, sizeof(u_int)); 160 mtx_lock(&lo_mtx); 161 LIST_INSERT_HEAD(&lo_list, sc, sc_next); 162 mtx_unlock(&lo_mtx); 163 if (loif == NULL) 164 loif = &sc->sc_if; 165 166 return (0); 167 } 168 169 static int 170 loop_modevent(module_t mod, int type, void *data) 171 { 172 switch (type) { 173 case MOD_LOAD: 174 mtx_init(&lo_mtx, "lo_mtx", NULL, MTX_DEF); 175 LIST_INIT(&lo_list); 176 if_clone_attach(&lo_cloner); 177 break; 178 case MOD_UNLOAD: 179 printf("loop module unload - not possible for this module type\n"); 180 return EINVAL; 181 } 182 return 0; 183 } 184 185 static moduledata_t loop_mod = { 186 "loop", 187 loop_modevent, 188 0 189 }; 190 191 DECLARE_MODULE(loop, loop_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 192 193 int 194 looutput(ifp, m, dst, rt) 195 struct ifnet *ifp; 196 register struct mbuf *m; 197 struct sockaddr *dst; 198 register struct rtentry *rt; 199 { 200 M_ASSERTPKTHDR(m); /* check if we have the packet header */ 201 202 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 203 m_freem(m); 204 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 205 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 206 } 207 208 ifp->if_opackets++; 209 ifp->if_obytes += m->m_pkthdr.len; 210 #if 1 /* XXX */ 211 switch (dst->sa_family) { 212 case AF_INET: 213 case AF_INET6: 214 case AF_IPX: 215 case AF_APPLETALK: 216 break; 217 default: 218 printf("looutput: af=%d unexpected\n", dst->sa_family); 219 m_freem(m); 220 return (EAFNOSUPPORT); 221 } 222 #endif 223 return(if_simloop(ifp, m, dst->sa_family, 0)); 224 } 225 226 /* 227 * if_simloop() 228 * 229 * This function is to support software emulation of hardware loopback, 230 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 231 * hear their own broadcasts, we create a copy of the packet that we 232 * would normally receive via a hardware loopback. 233 * 234 * This function expects the packet to include the media header of length hlen. 235 */ 236 237 int 238 if_simloop(ifp, m, af, hlen) 239 struct ifnet *ifp; 240 struct mbuf *m; 241 int af; 242 int hlen; 243 { 244 int isr; 245 246 M_ASSERTPKTHDR(m); 247 m_tag_delete_nonpersistent(m); 248 m->m_pkthdr.rcvif = ifp; 249 250 /* BPF write needs to be handled specially */ 251 if (af == AF_UNSPEC) { 252 KASSERT(m->m_len >= sizeof(int), ("if_simloop: m_len")); 253 af = *(mtod(m, int *)); 254 m->m_len -= sizeof(int); 255 m->m_pkthdr.len -= sizeof(int); 256 m->m_data += sizeof(int); 257 } 258 259 /* Let BPF see incoming packet */ 260 if (ifp->if_bpf) { 261 if (ifp->if_bpf->bif_dlt == DLT_NULL) { 262 u_int32_t af1 = af; /* XXX beware sizeof(af) != 4 */ 263 /* 264 * We need to prepend the address family. 265 */ 266 bpf_mtap2(ifp->if_bpf, &af1, sizeof(af1), m); 267 } else 268 bpf_mtap(ifp->if_bpf, m); 269 } 270 271 /* Strip away media header */ 272 if (hlen > 0) { 273 m_adj(m, hlen); 274 #if defined(__alpha__) || defined(__ia64__) || defined(__sparc64__) 275 /* The alpha doesn't like unaligned data. 276 * We move data down in the first mbuf */ 277 if (mtod(m, vm_offset_t) & 3) { 278 KASSERT(hlen >= 3, ("if_simloop: hlen too small")); 279 bcopy(m->m_data, 280 (char *)(mtod(m, vm_offset_t) 281 - (mtod(m, vm_offset_t) & 3)), 282 m->m_len); 283 mtod(m,vm_offset_t) -= (mtod(m, vm_offset_t) & 3); 284 } 285 #endif 286 } 287 288 /* Deliver to upper layer protocol */ 289 switch (af) { 290 #ifdef INET 291 case AF_INET: 292 isr = NETISR_IP; 293 break; 294 #endif 295 #ifdef INET6 296 case AF_INET6: 297 m->m_flags |= M_LOOP; 298 isr = NETISR_IPV6; 299 break; 300 #endif 301 #ifdef IPX 302 case AF_IPX: 303 isr = NETISR_IPX; 304 break; 305 #endif 306 #ifdef NETATALK 307 case AF_APPLETALK: 308 isr = NETISR_ATALK2; 309 break; 310 #endif 311 default: 312 printf("if_simloop: can't handle af=%d\n", af); 313 m_freem(m); 314 return (EAFNOSUPPORT); 315 } 316 ifp->if_ipackets++; 317 ifp->if_ibytes += m->m_pkthdr.len; 318 netisr_queue(isr, m); 319 return (0); 320 } 321 322 /* ARGSUSED */ 323 static void 324 lortrequest(cmd, rt, info) 325 int cmd; 326 struct rtentry *rt; 327 struct rt_addrinfo *info; 328 { 329 RT_LOCK_ASSERT(rt); 330 if (rt) 331 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; 332 } 333 334 /* 335 * Process an ioctl request. 336 */ 337 /* ARGSUSED */ 338 int 339 loioctl(ifp, cmd, data) 340 register struct ifnet *ifp; 341 u_long cmd; 342 caddr_t data; 343 { 344 register struct ifaddr *ifa; 345 register struct ifreq *ifr = (struct ifreq *)data; 346 register int error = 0; 347 348 switch (cmd) { 349 350 case SIOCSIFADDR: 351 ifp->if_flags |= IFF_UP | IFF_RUNNING; 352 ifa = (struct ifaddr *)data; 353 ifa->ifa_rtrequest = lortrequest; 354 /* 355 * Everything else is done at a higher level. 356 */ 357 break; 358 359 case SIOCADDMULTI: 360 case SIOCDELMULTI: 361 if (ifr == 0) { 362 error = EAFNOSUPPORT; /* XXX */ 363 break; 364 } 365 switch (ifr->ifr_addr.sa_family) { 366 367 #ifdef INET 368 case AF_INET: 369 break; 370 #endif 371 #ifdef INET6 372 case AF_INET6: 373 break; 374 #endif 375 376 default: 377 error = EAFNOSUPPORT; 378 break; 379 } 380 break; 381 382 case SIOCSIFMTU: 383 ifp->if_mtu = ifr->ifr_mtu; 384 break; 385 386 case SIOCSIFFLAGS: 387 break; 388 389 default: 390 error = EINVAL; 391 } 392 return (error); 393 } 394