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 void 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 = IF_CLONE_INITIALIZER(LONAME, 122 lo_clone_create, lo_clone_destroy, 1, IF_MAXUNIT); 123 124 void 125 lo_clone_destroy(ifp) 126 struct ifnet *ifp; 127 { 128 struct lo_softc *sc; 129 130 sc = ifp->if_softc; 131 132 /* XXX: destroying lo0 will lead to panics. */ 133 KASSERT(loif != ifp, ("%s: destroying lo0", __func__)); 134 135 bpfdetach(ifp); 136 if_detach(ifp); 137 LIST_REMOVE(sc, sc_next); 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 sc->sc_if.if_name = LONAME; 151 sc->sc_if.if_unit = unit; 152 sc->sc_if.if_mtu = LOMTU; 153 sc->sc_if.if_flags = IFF_LOOPBACK | IFF_MULTICAST; 154 sc->sc_if.if_ioctl = loioctl; 155 sc->sc_if.if_output = looutput; 156 sc->sc_if.if_type = IFT_LOOP; 157 sc->sc_if.if_snd.ifq_maxlen = ifqmaxlen; 158 sc->sc_if.if_softc = sc; 159 if_attach(&sc->sc_if); 160 bpfattach(&sc->sc_if, DLT_NULL, sizeof(u_int)); 161 LIST_INSERT_HEAD(&lo_list, sc, sc_next); 162 if (loif == NULL) 163 loif = &sc->sc_if; 164 165 return (0); 166 } 167 168 static int 169 loop_modevent(module_t mod, int type, void *data) 170 { 171 switch (type) { 172 case MOD_LOAD: 173 LIST_INIT(&lo_list); 174 if_clone_attach(&lo_cloner); 175 break; 176 case MOD_UNLOAD: 177 printf("loop module unload - not possible for this module type\n"); 178 return EINVAL; 179 } 180 return 0; 181 } 182 183 static moduledata_t loop_mod = { 184 "loop", 185 loop_modevent, 186 0 187 }; 188 189 DECLARE_MODULE(loop, loop_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 190 191 int 192 looutput(ifp, m, dst, rt) 193 struct ifnet *ifp; 194 register struct mbuf *m; 195 struct sockaddr *dst; 196 register struct rtentry *rt; 197 { 198 if ((m->m_flags & M_PKTHDR) == 0) 199 panic("looutput no HDR"); 200 201 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 202 m_freem(m); 203 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 204 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 205 } 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 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 211 */ 212 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 213 struct mbuf *n; 214 215 MGETHDR(n, M_DONTWAIT, MT_HEADER); 216 if (!n) 217 goto contiguousfail; 218 MCLGET(n, M_DONTWAIT); 219 if (! (n->m_flags & M_EXT)) { 220 m_freem(n); 221 goto contiguousfail; 222 } 223 224 m_copydata(m, 0, m->m_pkthdr.len, mtod(n, caddr_t)); 225 n->m_pkthdr = m->m_pkthdr; 226 n->m_len = m->m_pkthdr.len; 227 n->m_pkthdr.aux = m->m_pkthdr.aux; 228 m->m_pkthdr.aux = (struct mbuf *)NULL; 229 m_freem(m); 230 m = n; 231 } 232 if (0) { 233 contiguousfail: 234 printf("looutput: mbuf allocation failed\n"); 235 } 236 237 ifp->if_opackets++; 238 ifp->if_obytes += m->m_pkthdr.len; 239 #if 1 /* XXX */ 240 switch (dst->sa_family) { 241 case AF_INET: 242 case AF_INET6: 243 case AF_IPX: 244 case AF_NS: 245 case AF_APPLETALK: 246 break; 247 default: 248 printf("looutput: af=%d unexpected\n", dst->sa_family); 249 m_freem(m); 250 return (EAFNOSUPPORT); 251 } 252 #endif 253 return(if_simloop(ifp, m, dst->sa_family, 0)); 254 } 255 256 /* 257 * if_simloop() 258 * 259 * This function is to support software emulation of hardware loopback, 260 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 261 * hear their own broadcasts, we create a copy of the packet that we 262 * would normally receive via a hardware loopback. 263 * 264 * This function expects the packet to include the media header of length hlen. 265 */ 266 267 int 268 if_simloop(ifp, m, af, hlen) 269 struct ifnet *ifp; 270 struct mbuf *m; 271 int af; 272 int hlen; 273 { 274 int isr; 275 struct ifqueue *inq = 0; 276 277 KASSERT((m->m_flags & M_PKTHDR) != 0, ("if_simloop: no HDR")); 278 m->m_pkthdr.rcvif = ifp; 279 280 /* BPF write needs to be handled specially */ 281 if (af == AF_UNSPEC) { 282 KASSERT(m->m_len >= sizeof(int), ("if_simloop: m_len")); 283 af = *(mtod(m, int *)); 284 m->m_len -= sizeof(int); 285 m->m_pkthdr.len -= sizeof(int); 286 m->m_data += sizeof(int); 287 } 288 289 /* Let BPF see incoming packet */ 290 if (ifp->if_bpf) { 291 struct mbuf m0, *n = m; 292 293 if (ifp->if_bpf->bif_dlt == DLT_NULL) { 294 /* 295 * We need to prepend the address family as 296 * a four byte field. Cons up a dummy header 297 * to pacify bpf. This is safe because bpf 298 * will only read from the mbuf (i.e., it won't 299 * try to free it or keep a pointer a to it). 300 */ 301 m0.m_next = m; 302 m0.m_len = 4; 303 m0.m_data = (char *)⁡ 304 n = &m0; 305 } 306 bpf_mtap(ifp, n); 307 } 308 309 /* Strip away media header */ 310 if (hlen > 0) { 311 m_adj(m, hlen); 312 #if defined(__alpha__) || defined(__ia64__) || defined(__sparc64__) 313 /* The alpha doesn't like unaligned data. 314 * We move data down in the first mbuf */ 315 if (mtod(m, vm_offset_t) & 3) { 316 KASSERT(hlen >= 3, ("if_simloop: hlen too small")); 317 bcopy(m->m_data, 318 (char *)(mtod(m, vm_offset_t) 319 - (mtod(m, vm_offset_t) & 3)), 320 m->m_len); 321 mtod(m,vm_offset_t) -= (mtod(m, vm_offset_t) & 3); 322 } 323 #endif 324 } 325 326 /* Deliver to upper layer protocol */ 327 switch (af) { 328 #ifdef INET 329 case AF_INET: 330 inq = &ipintrq; 331 isr = NETISR_IP; 332 break; 333 #endif 334 #ifdef INET6 335 case AF_INET6: 336 m->m_flags |= M_LOOP; 337 inq = &ip6intrq; 338 isr = NETISR_IPV6; 339 break; 340 #endif 341 #ifdef IPX 342 case AF_IPX: 343 inq = &ipxintrq; 344 isr = NETISR_IPX; 345 break; 346 #endif 347 #ifdef NS 348 case AF_NS: 349 inq = &nsintrq; 350 isr = NETISR_NS; 351 break; 352 #endif 353 #ifdef NETATALK 354 case AF_APPLETALK: 355 inq = &atintrq2; 356 isr = NETISR_ATALK; 357 break; 358 #endif 359 default: 360 printf("if_simloop: can't handle af=%d\n", af); 361 m_freem(m); 362 return (EAFNOSUPPORT); 363 } 364 ifp->if_ipackets++; 365 ifp->if_ibytes += m->m_pkthdr.len; 366 (void) IF_HANDOFF(inq, m, NULL); 367 schednetisr(isr); 368 return (0); 369 } 370 371 /* ARGSUSED */ 372 static void 373 lortrequest(cmd, rt, info) 374 int cmd; 375 struct rtentry *rt; 376 struct rt_addrinfo *info; 377 { 378 if (rt) { 379 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; /* for ISO */ 380 /* 381 * For optimal performance, the send and receive buffers 382 * should be at least twice the MTU plus a little more for 383 * overhead. 384 */ 385 rt->rt_rmx.rmx_recvpipe = 386 rt->rt_rmx.rmx_sendpipe = 3 * LOMTU; 387 } 388 } 389 390 /* 391 * Process an ioctl request. 392 */ 393 /* ARGSUSED */ 394 int 395 loioctl(ifp, cmd, data) 396 register struct ifnet *ifp; 397 u_long cmd; 398 caddr_t data; 399 { 400 register struct ifaddr *ifa; 401 register struct ifreq *ifr = (struct ifreq *)data; 402 register int error = 0; 403 404 switch (cmd) { 405 406 case SIOCSIFADDR: 407 ifp->if_flags |= IFF_UP | IFF_RUNNING; 408 ifa = (struct ifaddr *)data; 409 ifa->ifa_rtrequest = lortrequest; 410 /* 411 * Everything else is done at a higher level. 412 */ 413 break; 414 415 case SIOCADDMULTI: 416 case SIOCDELMULTI: 417 if (ifr == 0) { 418 error = EAFNOSUPPORT; /* XXX */ 419 break; 420 } 421 switch (ifr->ifr_addr.sa_family) { 422 423 #ifdef INET 424 case AF_INET: 425 break; 426 #endif 427 #ifdef INET6 428 case AF_INET6: 429 break; 430 #endif 431 432 default: 433 error = EAFNOSUPPORT; 434 break; 435 } 436 break; 437 438 case SIOCSIFMTU: 439 ifp->if_mtu = ifr->ifr_mtu; 440 break; 441 442 case SIOCSIFFLAGS: 443 break; 444 445 default: 446 error = EINVAL; 447 } 448 return (error); 449 } 450