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 #ifdef INET6 195 struct mbuf *n; 196 #endif 197 198 M_ASSERTPKTHDR(m); /* check if we have the packet header */ 199 200 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 201 m_freem(m); 202 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 203 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 204 } 205 #ifdef INET6 206 /* 207 * KAME requires that the packet to be contiguous on the 208 * mbuf. We need to make that sure. 209 * this kind of code should be avoided. 210 * 211 * XXX: KAME may no longer need contiguous packets. Once 212 * that has been verified, the following code _should_ be 213 * removed. 214 */ 215 216 if (m && m->m_next != NULL) { 217 218 n = m_defrag(m, M_DONTWAIT); 219 220 if (n == NULL) { 221 m_freem(m); 222 return (ENOBUFS); 223 } else { 224 m = n; 225 } 226 } 227 #endif 228 229 ifp->if_opackets++; 230 ifp->if_obytes += m->m_pkthdr.len; 231 #if 1 /* XXX */ 232 switch (dst->sa_family) { 233 case AF_INET: 234 case AF_INET6: 235 case AF_IPX: 236 case AF_APPLETALK: 237 break; 238 default: 239 printf("looutput: af=%d unexpected\n", dst->sa_family); 240 m_freem(m); 241 return (EAFNOSUPPORT); 242 } 243 #endif 244 return(if_simloop(ifp, m, dst->sa_family, 0)); 245 } 246 247 /* 248 * if_simloop() 249 * 250 * This function is to support software emulation of hardware loopback, 251 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 252 * hear their own broadcasts, we create a copy of the packet that we 253 * would normally receive via a hardware loopback. 254 * 255 * This function expects the packet to include the media header of length hlen. 256 */ 257 258 int 259 if_simloop(ifp, m, af, hlen) 260 struct ifnet *ifp; 261 struct mbuf *m; 262 int af; 263 int hlen; 264 { 265 int isr; 266 267 M_ASSERTPKTHDR(m); 268 m_tag_delete_nonpersistent(m); 269 m->m_pkthdr.rcvif = ifp; 270 271 /* BPF write needs to be handled specially */ 272 if (af == AF_UNSPEC) { 273 KASSERT(m->m_len >= sizeof(int), ("if_simloop: m_len")); 274 af = *(mtod(m, int *)); 275 m->m_len -= sizeof(int); 276 m->m_pkthdr.len -= sizeof(int); 277 m->m_data += sizeof(int); 278 } 279 280 /* Let BPF see incoming packet */ 281 if (ifp->if_bpf) { 282 struct mbuf m0, *n = m; 283 284 if (ifp->if_bpf->bif_dlt == DLT_NULL) { 285 /* 286 * We need to prepend the address family as 287 * a four byte field. Cons up a dummy header 288 * to pacify bpf. This is safe because bpf 289 * will only read from the mbuf (i.e., it won't 290 * try to free it or keep a pointer a to it). 291 */ 292 m0.m_next = m; 293 m0.m_len = 4; 294 m0.m_data = (char *)⁡ 295 n = &m0; 296 } 297 BPF_MTAP(ifp, n); 298 } 299 300 /* Strip away media header */ 301 if (hlen > 0) { 302 m_adj(m, hlen); 303 #if defined(__alpha__) || defined(__ia64__) || defined(__sparc64__) 304 /* The alpha doesn't like unaligned data. 305 * We move data down in the first mbuf */ 306 if (mtod(m, vm_offset_t) & 3) { 307 KASSERT(hlen >= 3, ("if_simloop: hlen too small")); 308 bcopy(m->m_data, 309 (char *)(mtod(m, vm_offset_t) 310 - (mtod(m, vm_offset_t) & 3)), 311 m->m_len); 312 mtod(m,vm_offset_t) -= (mtod(m, vm_offset_t) & 3); 313 } 314 #endif 315 } 316 317 /* Deliver to upper layer protocol */ 318 switch (af) { 319 #ifdef INET 320 case AF_INET: 321 isr = NETISR_IP; 322 break; 323 #endif 324 #ifdef INET6 325 case AF_INET6: 326 m->m_flags |= M_LOOP; 327 isr = NETISR_IPV6; 328 break; 329 #endif 330 #ifdef IPX 331 case AF_IPX: 332 isr = NETISR_IPX; 333 break; 334 #endif 335 #ifdef NETATALK 336 case AF_APPLETALK: 337 isr = NETISR_ATALK2; 338 break; 339 #endif 340 default: 341 printf("if_simloop: can't handle af=%d\n", af); 342 m_freem(m); 343 return (EAFNOSUPPORT); 344 } 345 ifp->if_ipackets++; 346 ifp->if_ibytes += m->m_pkthdr.len; 347 netisr_queue(isr, m); 348 return (0); 349 } 350 351 /* ARGSUSED */ 352 static void 353 lortrequest(cmd, rt, info) 354 int cmd; 355 struct rtentry *rt; 356 struct rt_addrinfo *info; 357 { 358 RT_LOCK_ASSERT(rt); 359 360 if (rt) { 361 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; /* for ISO */ 362 /* 363 * For optimal performance, the send and receive buffers 364 * should be at least twice the MTU plus a little more for 365 * overhead. 366 */ 367 rt->rt_rmx.rmx_recvpipe = 368 rt->rt_rmx.rmx_sendpipe = 3 * LOMTU; 369 } 370 } 371 372 /* 373 * Process an ioctl request. 374 */ 375 /* ARGSUSED */ 376 int 377 loioctl(ifp, cmd, data) 378 register struct ifnet *ifp; 379 u_long cmd; 380 caddr_t data; 381 { 382 register struct ifaddr *ifa; 383 register struct ifreq *ifr = (struct ifreq *)data; 384 register int error = 0; 385 386 switch (cmd) { 387 388 case SIOCSIFADDR: 389 ifp->if_flags |= IFF_UP | IFF_RUNNING; 390 ifa = (struct ifaddr *)data; 391 ifa->ifa_rtrequest = lortrequest; 392 /* 393 * Everything else is done at a higher level. 394 */ 395 break; 396 397 case SIOCADDMULTI: 398 case SIOCDELMULTI: 399 if (ifr == 0) { 400 error = EAFNOSUPPORT; /* XXX */ 401 break; 402 } 403 switch (ifr->ifr_addr.sa_family) { 404 405 #ifdef INET 406 case AF_INET: 407 break; 408 #endif 409 #ifdef INET6 410 case AF_INET6: 411 break; 412 #endif 413 414 default: 415 error = EAFNOSUPPORT; 416 break; 417 } 418 break; 419 420 case SIOCSIFMTU: 421 ifp->if_mtu = ifr->ifr_mtu; 422 break; 423 424 case SIOCSIFFLAGS: 425 break; 426 427 default: 428 error = EINVAL; 429 } 430 return (error); 431 } 432