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 8.1 (Berkeley) 6/10/93 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 <sys/socket.h> 53 #include <sys/sockio.h> 54 #include <sys/sysctl.h> 55 56 #include <net/if.h> 57 #include <net/if_types.h> 58 #include <net/netisr.h> 59 #include <net/route.h> 60 #include <net/bpf.h> 61 #include <net/bpfdesc.h> 62 63 #ifdef INET 64 #include <netinet/in.h> 65 #include <netinet/in_var.h> 66 #endif 67 68 #ifdef IPX 69 #include <netipx/ipx.h> 70 #include <netipx/ipx_if.h> 71 #endif 72 73 #ifdef INET6 74 #ifndef INET 75 #include <netinet/in.h> 76 #endif 77 #include <netinet6/in6_var.h> 78 #include <netinet/ip6.h> 79 #endif 80 81 #ifdef NS 82 #include <netns/ns.h> 83 #include <netns/ns_if.h> 84 #endif 85 86 #ifdef NETATALK 87 #include <netatalk/at.h> 88 #include <netatalk/at_var.h> 89 #endif 90 91 int loioctl __P((struct ifnet *, u_long, caddr_t)); 92 static void lortrequest __P((int, struct rtentry *, struct sockaddr *)); 93 94 int looutput __P((struct ifnet *ifp, 95 struct mbuf *m, struct sockaddr *dst, struct rtentry *rt)); 96 97 #ifdef TINY_LOMTU 98 #define LOMTU (1024+512) 99 #elif defined(LARGE_LOMTU) 100 #define LOMTU 131072 101 #else 102 #define LOMTU 16384 103 #endif 104 105 static int nloop = 1; 106 107 struct ifnet *loif; /* Used externally */ 108 109 static MALLOC_DEFINE(M_LO, "lo", "Loopback Interface"); 110 111 struct lo_softc { 112 struct ifnet sc_if; /* network-visible interface */ 113 LIST_ENTRY(lo_softc) sc_next; 114 }; 115 static LIST_HEAD(lo_list, lo_softc) lo_list; 116 117 static void 118 locreate(int unit) 119 { 120 struct lo_softc *sc; 121 122 MALLOC(sc, struct lo_softc *, sizeof(*sc), M_LO, M_WAITOK | M_ZERO); 123 124 sc->sc_if.if_name = "lo"; 125 sc->sc_if.if_unit = unit; 126 sc->sc_if.if_mtu = LOMTU; 127 sc->sc_if.if_flags = IFF_LOOPBACK | IFF_MULTICAST; 128 sc->sc_if.if_ioctl = loioctl; 129 sc->sc_if.if_output = looutput; 130 sc->sc_if.if_type = IFT_LOOP; 131 sc->sc_if.if_snd.ifq_maxlen = ifqmaxlen; 132 if_attach(&sc->sc_if); 133 bpfattach(&sc->sc_if, DLT_NULL, sizeof(u_int)); 134 LIST_INSERT_HEAD(&lo_list, sc, sc_next); 135 if (loif == NULL) 136 loif = &sc->sc_if; 137 } 138 139 static void 140 lodestroy(struct lo_softc *sc) 141 { 142 bpfdetach(&sc->sc_if); 143 if_detach(&sc->sc_if); 144 LIST_REMOVE(sc, sc_next); 145 FREE(sc, M_LO); 146 } 147 148 149 static int 150 sysctl_net_nloop(SYSCTL_HANDLER_ARGS) 151 { 152 int newnloop; 153 int error; 154 155 newnloop = nloop; 156 157 error = sysctl_handle_opaque(oidp, &newnloop, sizeof newnloop, req); 158 if (error || !req->newptr) 159 return (error); 160 161 if (newnloop < 1) 162 return (EINVAL); 163 while (newnloop > nloop) { 164 locreate(nloop); 165 nloop++; 166 } 167 while (newnloop < nloop) { 168 lodestroy(LIST_FIRST(&lo_list)); 169 nloop--; 170 } 171 return (0); 172 } 173 SYSCTL_PROC(_net, OID_AUTO, nloop, CTLTYPE_INT | CTLFLAG_RW, 174 0, 0, sysctl_net_nloop, "I", ""); 175 176 static int 177 loop_modevent(module_t mod, int type, void *data) 178 { 179 int i; 180 181 switch (type) { 182 case MOD_LOAD: 183 TUNABLE_INT_FETCH("net.nloop", &nloop); 184 if (nloop < 1) /* sanity check */ 185 nloop = 1; 186 for (i = 0; i < nloop; i++) 187 locreate(i); 188 break; 189 case MOD_UNLOAD: 190 printf("loop module unload - not possible for this module type\n"); 191 return EINVAL; 192 } 193 return 0; 194 } 195 196 static moduledata_t loop_mod = { 197 "loop", 198 loop_modevent, 199 0 200 }; 201 202 DECLARE_MODULE(loop, loop_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 203 204 int 205 looutput(ifp, m, dst, rt) 206 struct ifnet *ifp; 207 register struct mbuf *m; 208 struct sockaddr *dst; 209 register struct rtentry *rt; 210 { 211 if ((m->m_flags & M_PKTHDR) == 0) 212 panic("looutput no HDR"); 213 214 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 215 m_freem(m); 216 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 217 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 218 } 219 /* 220 * KAME requires that the packet to be contiguous on the 221 * mbuf. We need to make that sure. 222 * this kind of code should be avoided. 223 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 224 */ 225 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 226 struct mbuf *n; 227 228 MGETHDR(n, M_DONTWAIT, MT_HEADER); 229 if (!n) 230 goto contiguousfail; 231 MCLGET(n, M_DONTWAIT); 232 if (! (n->m_flags & M_EXT)) { 233 m_freem(n); 234 goto contiguousfail; 235 } 236 237 m_copydata(m, 0, m->m_pkthdr.len, mtod(n, caddr_t)); 238 n->m_pkthdr = m->m_pkthdr; 239 n->m_len = m->m_pkthdr.len; 240 n->m_pkthdr.aux = m->m_pkthdr.aux; 241 m->m_pkthdr.aux = (struct mbuf *)NULL; 242 m_freem(m); 243 m = n; 244 } 245 if (0) { 246 contiguousfail: 247 printf("looutput: mbuf allocation failed\n"); 248 } 249 250 ifp->if_opackets++; 251 ifp->if_obytes += m->m_pkthdr.len; 252 #if 1 /* XXX */ 253 switch (dst->sa_family) { 254 case AF_INET: 255 case AF_INET6: 256 case AF_IPX: 257 case AF_NS: 258 case AF_APPLETALK: 259 break; 260 default: 261 printf("looutput: af=%d unexpected\n", dst->sa_family); 262 m_freem(m); 263 return (EAFNOSUPPORT); 264 } 265 #endif 266 return(if_simloop(ifp, m, dst->sa_family, 0)); 267 } 268 269 /* 270 * if_simloop() 271 * 272 * This function is to support software emulation of hardware loopback, 273 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 274 * hear their own broadcasts, we create a copy of the packet that we 275 * would normally receive via a hardware loopback. 276 * 277 * This function expects the packet to include the media header of length hlen. 278 */ 279 280 int 281 if_simloop(ifp, m, af, hlen) 282 struct ifnet *ifp; 283 struct mbuf *m; 284 int af; 285 int hlen; 286 { 287 int isr; 288 struct ifqueue *inq = 0; 289 290 KASSERT((m->m_flags & M_PKTHDR) != 0, ("if_simloop: no HDR")); 291 m->m_pkthdr.rcvif = ifp; 292 293 /* BPF write needs to be handled specially */ 294 if (af == AF_UNSPEC) { 295 KASSERT(m->m_len >= sizeof(int), ("if_simloop: m_len")); 296 af = *(mtod(m, int *)); 297 m->m_len -= sizeof(int); 298 m->m_pkthdr.len -= sizeof(int); 299 m->m_data += sizeof(int); 300 } 301 302 /* Let BPF see incoming packet */ 303 if (ifp->if_bpf) { 304 struct mbuf m0, *n = m; 305 306 if (ifp->if_bpf->bif_dlt == DLT_NULL) { 307 /* 308 * We need to prepend the address family as 309 * a four byte field. Cons up a dummy header 310 * to pacify bpf. This is safe because bpf 311 * will only read from the mbuf (i.e., it won't 312 * try to free it or keep a pointer a to it). 313 */ 314 m0.m_next = m; 315 m0.m_len = 4; 316 m0.m_data = (char *)⁡ 317 n = &m0; 318 } 319 bpf_mtap(ifp, n); 320 } 321 322 /* Strip away media header */ 323 if (hlen > 0) { 324 m_adj(m, hlen); 325 #ifdef __alpha__ 326 /* The alpha doesn't like unaligned data. 327 * We move data down in the first mbuf */ 328 if (mtod(m, vm_offset_t) & 3) { 329 KASSERT(hlen >= 3, ("if_simloop: hlen too small")); 330 bcopy(m->m_data, 331 (char *)(mtod(m, vm_offset_t) 332 - (mtod(m, vm_offset_t) & 3)), 333 m->m_len); 334 mtod(m,vm_offset_t) -= (mtod(m, vm_offset_t) & 3); 335 } 336 #endif 337 } 338 339 /* Deliver to upper layer protocol */ 340 switch (af) { 341 #ifdef INET 342 case AF_INET: 343 inq = &ipintrq; 344 isr = NETISR_IP; 345 break; 346 #endif 347 #ifdef INET6 348 case AF_INET6: 349 m->m_flags |= M_LOOP; 350 inq = &ip6intrq; 351 isr = NETISR_IPV6; 352 break; 353 #endif 354 #ifdef IPX 355 case AF_IPX: 356 inq = &ipxintrq; 357 isr = NETISR_IPX; 358 break; 359 #endif 360 #ifdef NS 361 case AF_NS: 362 inq = &nsintrq; 363 isr = NETISR_NS; 364 break; 365 #endif 366 #ifdef NETATALK 367 case AF_APPLETALK: 368 inq = &atintrq2; 369 isr = NETISR_ATALK; 370 break; 371 #endif 372 default: 373 printf("if_simloop: can't handle af=%d\n", af); 374 m_freem(m); 375 return (EAFNOSUPPORT); 376 } 377 ifp->if_ipackets++; 378 ifp->if_ibytes += m->m_pkthdr.len; 379 (void) IF_HANDOFF(inq, m, NULL); 380 schednetisr(isr); 381 return (0); 382 } 383 384 /* ARGSUSED */ 385 static void 386 lortrequest(cmd, rt, sa) 387 int cmd; 388 struct rtentry *rt; 389 struct sockaddr *sa; 390 { 391 if (rt) { 392 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; /* for ISO */ 393 /* 394 * For optimal performance, the send and receive buffers 395 * should be at least twice the MTU plus a little more for 396 * overhead. 397 */ 398 rt->rt_rmx.rmx_recvpipe = 399 rt->rt_rmx.rmx_sendpipe = 3 * LOMTU; 400 } 401 } 402 403 /* 404 * Process an ioctl request. 405 */ 406 /* ARGSUSED */ 407 int 408 loioctl(ifp, cmd, data) 409 register struct ifnet *ifp; 410 u_long cmd; 411 caddr_t data; 412 { 413 register struct ifaddr *ifa; 414 register struct ifreq *ifr = (struct ifreq *)data; 415 register int error = 0; 416 417 switch (cmd) { 418 419 case SIOCSIFADDR: 420 ifp->if_flags |= IFF_UP | IFF_RUNNING; 421 ifa = (struct ifaddr *)data; 422 ifa->ifa_rtrequest = lortrequest; 423 /* 424 * Everything else is done at a higher level. 425 */ 426 break; 427 428 case SIOCADDMULTI: 429 case SIOCDELMULTI: 430 if (ifr == 0) { 431 error = EAFNOSUPPORT; /* XXX */ 432 break; 433 } 434 switch (ifr->ifr_addr.sa_family) { 435 436 #ifdef INET 437 case AF_INET: 438 break; 439 #endif 440 #ifdef INET6 441 case AF_INET6: 442 break; 443 #endif 444 445 default: 446 error = EAFNOSUPPORT; 447 break; 448 } 449 break; 450 451 case SIOCSIFMTU: 452 ifp->if_mtu = ifr->ifr_mtu; 453 break; 454 455 case SIOCSIFFLAGS: 456 break; 457 458 default: 459 error = EINVAL; 460 } 461 return (error); 462 } 463