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