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 LIST_HEAD(lo_list, lo_softc) lo_list; 117 118 struct if_clone lo_cloner = IF_CLONE_INITIALIZER(LONAME, 119 lo_clone_create, lo_clone_destroy, 1, IF_MAXUNIT); 120 121 void 122 lo_clone_destroy(ifp) 123 struct ifnet *ifp; 124 { 125 struct lo_softc *sc; 126 127 sc = ifp->if_softc; 128 129 /* XXX: destroying lo0 will lead to panics. */ 130 KASSERT(loif != ifp, ("%s: destroying lo0", __func__)); 131 132 bpfdetach(ifp); 133 if_detach(ifp); 134 LIST_REMOVE(sc, sc_next); 135 free(sc, M_LO); 136 } 137 138 int 139 lo_clone_create(ifc, unit) 140 struct if_clone *ifc; 141 int unit; 142 { 143 struct lo_softc *sc; 144 145 MALLOC(sc, struct lo_softc *, sizeof(*sc), M_LO, M_WAITOK | M_ZERO); 146 147 if_initname(&sc->sc_if, ifc->ifc_name, unit); 148 sc->sc_if.if_mtu = LOMTU; 149 sc->sc_if.if_flags = IFF_LOOPBACK | IFF_MULTICAST; 150 sc->sc_if.if_ioctl = loioctl; 151 sc->sc_if.if_output = looutput; 152 sc->sc_if.if_type = IFT_LOOP; 153 sc->sc_if.if_snd.ifq_maxlen = ifqmaxlen; 154 sc->sc_if.if_softc = sc; 155 if_attach(&sc->sc_if); 156 bpfattach(&sc->sc_if, DLT_NULL, sizeof(u_int)); 157 LIST_INSERT_HEAD(&lo_list, sc, sc_next); 158 if (loif == NULL) 159 loif = &sc->sc_if; 160 161 return (0); 162 } 163 164 static int 165 loop_modevent(module_t mod, int type, void *data) 166 { 167 switch (type) { 168 case MOD_LOAD: 169 LIST_INIT(&lo_list); 170 if_clone_attach(&lo_cloner); 171 break; 172 case MOD_UNLOAD: 173 printf("loop module unload - not possible for this module type\n"); 174 return EINVAL; 175 } 176 return 0; 177 } 178 179 static moduledata_t loop_mod = { 180 "loop", 181 loop_modevent, 182 0 183 }; 184 185 DECLARE_MODULE(loop, loop_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 186 187 int 188 looutput(ifp, m, dst, rt) 189 struct ifnet *ifp; 190 register struct mbuf *m; 191 struct sockaddr *dst; 192 register struct rtentry *rt; 193 { 194 M_ASSERTPKTHDR(m); /* check if we have the packet header */ 195 196 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 197 m_freem(m); 198 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 199 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 200 } 201 202 ifp->if_opackets++; 203 ifp->if_obytes += m->m_pkthdr.len; 204 #if 1 /* XXX */ 205 switch (dst->sa_family) { 206 case AF_INET: 207 case AF_INET6: 208 case AF_IPX: 209 case AF_APPLETALK: 210 break; 211 default: 212 printf("looutput: af=%d unexpected\n", dst->sa_family); 213 m_freem(m); 214 return (EAFNOSUPPORT); 215 } 216 #endif 217 return(if_simloop(ifp, m, dst->sa_family, 0)); 218 } 219 220 /* 221 * if_simloop() 222 * 223 * This function is to support software emulation of hardware loopback, 224 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 225 * hear their own broadcasts, we create a copy of the packet that we 226 * would normally receive via a hardware loopback. 227 * 228 * This function expects the packet to include the media header of length hlen. 229 */ 230 231 int 232 if_simloop(ifp, m, af, hlen) 233 struct ifnet *ifp; 234 struct mbuf *m; 235 int af; 236 int hlen; 237 { 238 int isr; 239 240 M_ASSERTPKTHDR(m); 241 m_tag_delete_nonpersistent(m); 242 m->m_pkthdr.rcvif = ifp; 243 244 /* BPF write needs to be handled specially */ 245 if (af == AF_UNSPEC) { 246 KASSERT(m->m_len >= sizeof(int), ("if_simloop: m_len")); 247 af = *(mtod(m, int *)); 248 m->m_len -= sizeof(int); 249 m->m_pkthdr.len -= sizeof(int); 250 m->m_data += sizeof(int); 251 } 252 253 /* Let BPF see incoming packet */ 254 if (ifp->if_bpf) { 255 struct mbuf m0, *n = m; 256 257 if (ifp->if_bpf->bif_dlt == DLT_NULL) { 258 /* 259 * We need to prepend the address family as 260 * a four byte field. Cons up a dummy header 261 * to pacify bpf. This is safe because bpf 262 * will only read from the mbuf (i.e., it won't 263 * try to free it or keep a pointer a to it). 264 */ 265 m0.m_next = m; 266 m0.m_len = 4; 267 m0.m_data = (char *)⁡ 268 n = &m0; 269 } 270 BPF_MTAP(ifp, n); 271 } 272 273 /* Strip away media header */ 274 if (hlen > 0) { 275 m_adj(m, hlen); 276 #if defined(__alpha__) || defined(__ia64__) || defined(__sparc64__) 277 /* The alpha doesn't like unaligned data. 278 * We move data down in the first mbuf */ 279 if (mtod(m, vm_offset_t) & 3) { 280 KASSERT(hlen >= 3, ("if_simloop: hlen too small")); 281 bcopy(m->m_data, 282 (char *)(mtod(m, vm_offset_t) 283 - (mtod(m, vm_offset_t) & 3)), 284 m->m_len); 285 mtod(m,vm_offset_t) -= (mtod(m, vm_offset_t) & 3); 286 } 287 #endif 288 } 289 290 /* Deliver to upper layer protocol */ 291 switch (af) { 292 #ifdef INET 293 case AF_INET: 294 isr = NETISR_IP; 295 break; 296 #endif 297 #ifdef INET6 298 case AF_INET6: 299 m->m_flags |= M_LOOP; 300 isr = NETISR_IPV6; 301 break; 302 #endif 303 #ifdef IPX 304 case AF_IPX: 305 isr = NETISR_IPX; 306 break; 307 #endif 308 #ifdef NETATALK 309 case AF_APPLETALK: 310 isr = NETISR_ATALK2; 311 break; 312 #endif 313 default: 314 printf("if_simloop: can't handle af=%d\n", af); 315 m_freem(m); 316 return (EAFNOSUPPORT); 317 } 318 ifp->if_ipackets++; 319 ifp->if_ibytes += m->m_pkthdr.len; 320 netisr_queue(isr, m); 321 return (0); 322 } 323 324 /* ARGSUSED */ 325 static void 326 lortrequest(cmd, rt, info) 327 int cmd; 328 struct rtentry *rt; 329 struct rt_addrinfo *info; 330 { 331 RT_LOCK_ASSERT(rt); 332 333 if (rt) { 334 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; /* for ISO */ 335 /* 336 * For optimal performance, the send and receive buffers 337 * should be at least twice the MTU plus a little more for 338 * overhead. 339 */ 340 rt->rt_rmx.rmx_recvpipe = 341 rt->rt_rmx.rmx_sendpipe = 3 * LOMTU; 342 } 343 } 344 345 /* 346 * Process an ioctl request. 347 */ 348 /* ARGSUSED */ 349 int 350 loioctl(ifp, cmd, data) 351 register struct ifnet *ifp; 352 u_long cmd; 353 caddr_t data; 354 { 355 register struct ifaddr *ifa; 356 register struct ifreq *ifr = (struct ifreq *)data; 357 register int error = 0; 358 359 switch (cmd) { 360 361 case SIOCSIFADDR: 362 ifp->if_flags |= IFF_UP | IFF_RUNNING; 363 ifa = (struct ifaddr *)data; 364 ifa->ifa_rtrequest = lortrequest; 365 /* 366 * Everything else is done at a higher level. 367 */ 368 break; 369 370 case SIOCADDMULTI: 371 case SIOCDELMULTI: 372 if (ifr == 0) { 373 error = EAFNOSUPPORT; /* XXX */ 374 break; 375 } 376 switch (ifr->ifr_addr.sa_family) { 377 378 #ifdef INET 379 case AF_INET: 380 break; 381 #endif 382 #ifdef INET6 383 case AF_INET6: 384 break; 385 #endif 386 387 default: 388 error = EAFNOSUPPORT; 389 break; 390 } 391 break; 392 393 case SIOCSIFMTU: 394 ifp->if_mtu = ifr->ifr_mtu; 395 break; 396 397 case SIOCSIFFLAGS: 398 break; 399 400 default: 401 error = EINVAL; 402 } 403 return (error); 404 } 405