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 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/kernel.h> 49 #include <sys/malloc.h> 50 #include <sys/mbuf.h> 51 #include <sys/module.h> 52 #include <machine/bus.h> 53 #include <sys/rman.h> 54 #include <sys/socket.h> 55 #include <sys/sockio.h> 56 #include <sys/sysctl.h> 57 58 #include <net/if.h> 59 #include <net/if_types.h> 60 #include <net/netisr.h> 61 #include <net/route.h> 62 #include <net/bpf.h> 63 #include <net/bpfdesc.h> 64 65 #ifdef INET 66 #include <netinet/in.h> 67 #include <netinet/in_var.h> 68 #endif 69 70 #ifdef IPX 71 #include <netipx/ipx.h> 72 #include <netipx/ipx_if.h> 73 #endif 74 75 #ifdef INET6 76 #ifndef INET 77 #include <netinet/in.h> 78 #endif 79 #include <netinet6/in6_var.h> 80 #include <netinet/ip6.h> 81 #endif 82 83 #ifdef NS 84 #include <netns/ns.h> 85 #include <netns/ns_if.h> 86 #endif 87 88 #ifdef NETATALK 89 #include <netatalk/at.h> 90 #include <netatalk/at_var.h> 91 #endif 92 93 #ifdef TINY_LOMTU 94 #define LOMTU (1024+512) 95 #elif defined(LARGE_LOMTU) 96 #define LOMTU 131072 97 #else 98 #define LOMTU 16384 99 #endif 100 101 #define LONAME "lo" 102 103 struct lo_softc { 104 struct ifnet sc_if; /* network-visible interface */ 105 LIST_ENTRY(lo_softc) sc_next; 106 }; 107 108 int loioctl(struct ifnet *, u_long, caddr_t); 109 static void lortrequest(int, struct rtentry *, struct rt_addrinfo *); 110 int looutput(struct ifnet *ifp, struct mbuf *m, 111 struct sockaddr *dst, struct rtentry *rt); 112 int lo_clone_create(struct if_clone *, int); 113 int lo_clone_destroy(struct ifnet *); 114 115 struct ifnet *loif = NULL; /* Used externally */ 116 117 static MALLOC_DEFINE(M_LO, LONAME, "Loopback Interface"); 118 119 static LIST_HEAD(lo_list, lo_softc) lo_list; 120 121 struct if_clone lo_cloner = 122 IF_CLONE_INITIALIZER(LONAME, lo_clone_create, lo_clone_destroy, IF_MAXUNIT); 123 124 int 125 lo_clone_destroy(ifp) 126 struct ifnet *ifp; 127 { 128 struct lo_softc *sc; 129 130 sc = ifp->if_softc; 131 132 /* 133 * Prevent lo0 from being destroyed. 134 */ 135 if (loif == ifp) 136 return (EINVAL); 137 138 bpfdetach(ifp); 139 if_detach(ifp); 140 LIST_REMOVE(sc, sc_next); 141 free(sc, M_LO); 142 return (0); 143 } 144 145 int 146 lo_clone_create(ifc, unit) 147 struct if_clone *ifc; 148 int unit; 149 { 150 struct lo_softc *sc; 151 152 MALLOC(sc, struct lo_softc *, sizeof(*sc), M_LO, M_WAITOK | M_ZERO); 153 154 sc->sc_if.if_name = LONAME; 155 sc->sc_if.if_unit = unit; 156 sc->sc_if.if_mtu = LOMTU; 157 sc->sc_if.if_flags = IFF_LOOPBACK | IFF_MULTICAST; 158 sc->sc_if.if_ioctl = loioctl; 159 sc->sc_if.if_output = looutput; 160 sc->sc_if.if_type = IFT_LOOP; 161 sc->sc_if.if_snd.ifq_maxlen = ifqmaxlen; 162 sc->sc_if.if_softc = sc; 163 if_attach(&sc->sc_if); 164 bpfattach(&sc->sc_if, DLT_NULL, sizeof(u_int)); 165 LIST_INSERT_HEAD(&lo_list, sc, sc_next); 166 if (loif == NULL) 167 loif = &sc->sc_if; 168 169 return (0); 170 } 171 172 static int 173 loop_modevent(module_t mod, int type, void *data) 174 { 175 int err; 176 177 switch (type) { 178 case MOD_LOAD: 179 LIST_INIT(&lo_list); 180 if_clone_attach(&lo_cloner); 181 182 /* Create lo0 */ 183 err = if_clone_create("lo0", sizeof ("lo0")); 184 KASSERT(err == 0, ("%s: can't create lo0", __func__)); 185 break; 186 case MOD_UNLOAD: 187 printf("loop module unload - not possible for this module type\n"); 188 return EINVAL; 189 } 190 return 0; 191 } 192 193 static moduledata_t loop_mod = { 194 "loop", 195 loop_modevent, 196 0 197 }; 198 199 DECLARE_MODULE(loop, loop_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 200 201 int 202 looutput(ifp, m, dst, rt) 203 struct ifnet *ifp; 204 register struct mbuf *m; 205 struct sockaddr *dst; 206 register struct rtentry *rt; 207 { 208 if ((m->m_flags & M_PKTHDR) == 0) 209 panic("looutput no HDR"); 210 211 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 212 m_freem(m); 213 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 214 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 215 } 216 /* 217 * KAME requires that the packet to be contiguous on the 218 * mbuf. We need to make that sure. 219 * this kind of code should be avoided. 220 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 221 */ 222 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 223 struct mbuf *n; 224 225 MGETHDR(n, M_DONTWAIT, MT_HEADER); 226 if (!n) 227 goto contiguousfail; 228 MCLGET(n, M_DONTWAIT); 229 if (! (n->m_flags & M_EXT)) { 230 m_freem(n); 231 goto contiguousfail; 232 } 233 234 m_copydata(m, 0, m->m_pkthdr.len, mtod(n, caddr_t)); 235 n->m_pkthdr = m->m_pkthdr; 236 n->m_len = m->m_pkthdr.len; 237 n->m_pkthdr.aux = m->m_pkthdr.aux; 238 m->m_pkthdr.aux = (struct mbuf *)NULL; 239 m_freem(m); 240 m = n; 241 } 242 if (0) { 243 contiguousfail: 244 printf("looutput: mbuf allocation failed\n"); 245 } 246 247 ifp->if_opackets++; 248 ifp->if_obytes += m->m_pkthdr.len; 249 #if 1 /* XXX */ 250 switch (dst->sa_family) { 251 case AF_INET: 252 case AF_INET6: 253 case AF_IPX: 254 case AF_NS: 255 case AF_APPLETALK: 256 break; 257 default: 258 printf("looutput: af=%d unexpected\n", dst->sa_family); 259 m_freem(m); 260 return (EAFNOSUPPORT); 261 } 262 #endif 263 return(if_simloop(ifp, m, dst->sa_family, 0)); 264 } 265 266 /* 267 * if_simloop() 268 * 269 * This function is to support software emulation of hardware loopback, 270 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 271 * hear their own broadcasts, we create a copy of the packet that we 272 * would normally receive via a hardware loopback. 273 * 274 * This function expects the packet to include the media header of length hlen. 275 */ 276 277 int 278 if_simloop(ifp, m, af, hlen) 279 struct ifnet *ifp; 280 struct mbuf *m; 281 int af; 282 int hlen; 283 { 284 int isr; 285 struct ifqueue *inq = 0; 286 287 KASSERT((m->m_flags & M_PKTHDR) != 0, ("if_simloop: no HDR")); 288 m->m_pkthdr.rcvif = ifp; 289 290 /* BPF write needs to be handled specially */ 291 if (af == AF_UNSPEC) { 292 KASSERT(m->m_len >= sizeof(int), ("if_simloop: m_len")); 293 af = *(mtod(m, int *)); 294 m->m_len -= sizeof(int); 295 m->m_pkthdr.len -= sizeof(int); 296 m->m_data += sizeof(int); 297 } 298 299 /* Let BPF see incoming packet */ 300 if (ifp->if_bpf) { 301 struct mbuf m0, *n = m; 302 303 if (ifp->if_bpf->bif_dlt == DLT_NULL) { 304 /* 305 * We need to prepend the address family as 306 * a four byte field. Cons up a dummy header 307 * to pacify bpf. This is safe because bpf 308 * will only read from the mbuf (i.e., it won't 309 * try to free it or keep a pointer a to it). 310 */ 311 m0.m_next = m; 312 m0.m_len = 4; 313 m0.m_data = (char *)⁡ 314 n = &m0; 315 } 316 bpf_mtap(ifp, n); 317 } 318 319 /* Strip away media header */ 320 if (hlen > 0) { 321 m_adj(m, hlen); 322 #if defined(__alpha__) || defined(__ia64__) || defined(__sparc64__) 323 /* The alpha doesn't like unaligned data. 324 * We move data down in the first mbuf */ 325 if (mtod(m, vm_offset_t) & 3) { 326 KASSERT(hlen >= 3, ("if_simloop: hlen too small")); 327 bcopy(m->m_data, 328 (char *)(mtod(m, vm_offset_t) 329 - (mtod(m, vm_offset_t) & 3)), 330 m->m_len); 331 mtod(m,vm_offset_t) -= (mtod(m, vm_offset_t) & 3); 332 } 333 #endif 334 } 335 336 /* Deliver to upper layer protocol */ 337 switch (af) { 338 #ifdef INET 339 case AF_INET: 340 inq = &ipintrq; 341 isr = NETISR_IP; 342 break; 343 #endif 344 #ifdef INET6 345 case AF_INET6: 346 m->m_flags |= M_LOOP; 347 inq = &ip6intrq; 348 isr = NETISR_IPV6; 349 break; 350 #endif 351 #ifdef IPX 352 case AF_IPX: 353 inq = &ipxintrq; 354 isr = NETISR_IPX; 355 break; 356 #endif 357 #ifdef NS 358 case AF_NS: 359 inq = &nsintrq; 360 isr = NETISR_NS; 361 break; 362 #endif 363 #ifdef NETATALK 364 case AF_APPLETALK: 365 inq = &atintrq2; 366 isr = NETISR_ATALK; 367 break; 368 #endif 369 default: 370 printf("if_simloop: can't handle af=%d\n", af); 371 m_freem(m); 372 return (EAFNOSUPPORT); 373 } 374 ifp->if_ipackets++; 375 ifp->if_ibytes += m->m_pkthdr.len; 376 (void) IF_HANDOFF(inq, m, NULL); 377 schednetisr(isr); 378 return (0); 379 } 380 381 /* ARGSUSED */ 382 static void 383 lortrequest(cmd, rt, info) 384 int cmd; 385 struct rtentry *rt; 386 struct rt_addrinfo *info; 387 { 388 if (rt) { 389 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; /* for ISO */ 390 /* 391 * For optimal performance, the send and receive buffers 392 * should be at least twice the MTU plus a little more for 393 * overhead. 394 */ 395 rt->rt_rmx.rmx_recvpipe = 396 rt->rt_rmx.rmx_sendpipe = 3 * LOMTU; 397 } 398 } 399 400 /* 401 * Process an ioctl request. 402 */ 403 /* ARGSUSED */ 404 int 405 loioctl(ifp, cmd, data) 406 register struct ifnet *ifp; 407 u_long cmd; 408 caddr_t data; 409 { 410 register struct ifaddr *ifa; 411 register struct ifreq *ifr = (struct ifreq *)data; 412 register int error = 0; 413 414 switch (cmd) { 415 416 case SIOCSIFADDR: 417 ifp->if_flags |= IFF_UP | IFF_RUNNING; 418 ifa = (struct ifaddr *)data; 419 ifa->ifa_rtrequest = lortrequest; 420 /* 421 * Everything else is done at a higher level. 422 */ 423 break; 424 425 case SIOCADDMULTI: 426 case SIOCDELMULTI: 427 if (ifr == 0) { 428 error = EAFNOSUPPORT; /* XXX */ 429 break; 430 } 431 switch (ifr->ifr_addr.sa_family) { 432 433 #ifdef INET 434 case AF_INET: 435 break; 436 #endif 437 #ifdef INET6 438 case AF_INET6: 439 break; 440 #endif 441 442 default: 443 error = EAFNOSUPPORT; 444 break; 445 } 446 break; 447 448 case SIOCSIFMTU: 449 ifp->if_mtu = ifr->ifr_mtu; 450 break; 451 452 case SIOCSIFFLAGS: 453 break; 454 455 default: 456 error = EINVAL; 457 } 458 return (error); 459 } 460