if_loop.c revision 105194
1209908Sraj/* 2209908Sraj * Copyright (c) 1982, 1986, 1993 3209908Sraj * The Regents of the University of California. All rights reserved. 4209908Sraj * 5209908Sraj * Redistribution and use in source and binary forms, with or without 6209908Sraj * modification, are permitted provided that the following conditions 7209908Sraj * are met: 8209908Sraj * 1. Redistributions of source code must retain the above copyright 9209908Sraj * notice, this list of conditions and the following disclaimer. 10209908Sraj * 2. Redistributions in binary form must reproduce the above copyright 11209908Sraj * notice, this list of conditions and the following disclaimer in the 12209908Sraj * documentation and/or other materials provided with the distribution. 13209908Sraj * 3. All advertising materials mentioning features or use of this software 14209908Sraj * must display the following acknowledgement: 15209908Sraj * This product includes software developed by the University of 16209908Sraj * California, Berkeley and its contributors. 17209908Sraj * 4. Neither the name of the University nor the names of its contributors 18209908Sraj * may be used to endorse or promote products derived from this software 19209908Sraj * without specific prior written permission. 20209908Sraj * 21209908Sraj * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22209908Sraj * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23209908Sraj * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24209908Sraj * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25209908Sraj * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26209908Sraj * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27209908Sraj * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28209908Sraj * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29209908Sraj * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30209908Sraj * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31209908Sraj * SUCH DAMAGE. 32209908Sraj * 33209908Sraj * @(#)if_loop.c 8.2 (Berkeley) 1/9/95 34209908Sraj * $FreeBSD: head/sys/net/if_loop.c 105194 2002-10-16 01:54:46Z sam $ 35209908Sraj */ 36209908Sraj 37209908Sraj/* 38209908Sraj * Loopback interface driver for protocol testing and timing. 39209908Sraj */ 40209908Sraj 41209908Sraj#include "opt_atalk.h" 42209908Sraj#include "opt_inet.h" 43209908Sraj#include "opt_inet6.h" 44209908Sraj#include "opt_ipx.h" 45209908Sraj 46209908Sraj#include <sys/param.h> 47209908Sraj#include <sys/systm.h> 48209908Sraj#include <sys/kernel.h> 49209908Sraj#include <sys/malloc.h> 50209908Sraj#include <sys/mbuf.h> 51209908Sraj#include <sys/module.h> 52209908Sraj#include <machine/bus.h> 53209908Sraj#include <sys/rman.h> 54209908Sraj#include <sys/socket.h> 55209908Sraj#include <sys/sockio.h> 56209908Sraj#include <sys/sysctl.h> 57209908Sraj 58209908Sraj#include <net/if.h> 59209908Sraj#include <net/if_types.h> 60209908Sraj#include <net/netisr.h> 61209908Sraj#include <net/route.h> 62209908Sraj#include <net/bpf.h> 63209908Sraj#include <net/bpfdesc.h> 64209908Sraj 65209908Sraj#ifdef INET 66209908Sraj#include <netinet/in.h> 67209908Sraj#include <netinet/in_var.h> 68209908Sraj#endif 69209908Sraj 70209908Sraj#ifdef IPX 71209908Sraj#include <netipx/ipx.h> 72209908Sraj#include <netipx/ipx_if.h> 73209908Sraj#endif 74209908Sraj 75209908Sraj#ifdef INET6 76209908Sraj#ifndef INET 77209908Sraj#include <netinet/in.h> 78209908Sraj#endif 79209908Sraj#include <netinet6/in6_var.h> 80209908Sraj#include <netinet/ip6.h> 81209908Sraj#endif 82209908Sraj 83209908Sraj#ifdef NS 84209908Sraj#include <netns/ns.h> 85209908Sraj#include <netns/ns_if.h> 86209908Sraj#endif 87209908Sraj 88209908Sraj#ifdef NETATALK 89209908Sraj#include <netatalk/at.h> 90209908Sraj#include <netatalk/at_var.h> 91209908Sraj#endif 92209908Sraj 93227843Smarius#ifdef TINY_LOMTU 94227843Smarius#define LOMTU (1024+512) 95209908Sraj#elif defined(LARGE_LOMTU) 96209908Sraj#define LOMTU 131072 97209908Sraj#else 98209908Sraj#define LOMTU 16384 99209908Sraj#endif 100209908Sraj 101209908Sraj#define LONAME "lo" 102209908Sraj 103209908Srajstruct lo_softc { 104209908Sraj struct ifnet sc_if; /* network-visible interface */ 105209908Sraj LIST_ENTRY(lo_softc) sc_next; 106209908Sraj}; 107209908Sraj 108209908Srajint loioctl(struct ifnet *, u_long, caddr_t); 109209908Srajstatic void lortrequest(int, struct rtentry *, struct rt_addrinfo *); 110209908Srajint looutput(struct ifnet *ifp, struct mbuf *m, 111209908Sraj struct sockaddr *dst, struct rtentry *rt); 112209908Srajint lo_clone_create(struct if_clone *, int); 113209908Srajvoid lo_clone_destroy(struct ifnet *); 114209908Sraj 115209908Srajstruct ifnet *loif = NULL; /* Used externally */ 116209908Sraj 117209908Srajstatic MALLOC_DEFINE(M_LO, LONAME, "Loopback Interface"); 118209908Sraj 119209908Srajstatic LIST_HEAD(lo_list, lo_softc) lo_list; 120209908Sraj 121209908Srajstruct if_clone lo_cloner = IF_CLONE_INITIALIZER(LONAME, 122209908Sraj lo_clone_create, lo_clone_destroy, 1, IF_MAXUNIT); 123209908Sraj 124209908Srajvoid 125209908Srajlo_clone_destroy(ifp) 126209908Sraj struct ifnet *ifp; 127209908Sraj{ 128209908Sraj struct lo_softc *sc; 129209908Sraj 130209908Sraj sc = ifp->if_softc; 131209908Sraj 132209908Sraj /* XXX: destroying lo0 will lead to panics. */ 133209908Sraj KASSERT(loif != ifp, ("%s: destroying lo0", __func__)); 134209908Sraj 135209908Sraj bpfdetach(ifp); 136209908Sraj if_detach(ifp); 137209908Sraj LIST_REMOVE(sc, sc_next); 138209908Sraj free(sc, M_LO); 139209908Sraj} 140209908Sraj 141209908Srajint 142209908Srajlo_clone_create(ifc, unit) 143209908Sraj struct if_clone *ifc; 144209908Sraj int unit; 145209908Sraj{ 146209908Sraj struct lo_softc *sc; 147209908Sraj 148209908Sraj MALLOC(sc, struct lo_softc *, sizeof(*sc), M_LO, M_WAITOK | M_ZERO); 149209908Sraj 150209908Sraj sc->sc_if.if_name = LONAME; 151209908Sraj sc->sc_if.if_unit = unit; 152209908Sraj sc->sc_if.if_mtu = LOMTU; 153209908Sraj sc->sc_if.if_flags = IFF_LOOPBACK | IFF_MULTICAST; 154209908Sraj sc->sc_if.if_ioctl = loioctl; 155209908Sraj sc->sc_if.if_output = looutput; 156209908Sraj sc->sc_if.if_type = IFT_LOOP; 157209908Sraj sc->sc_if.if_snd.ifq_maxlen = ifqmaxlen; 158232518Sraj sc->sc_if.if_softc = sc; 159232518Sraj if_attach(&sc->sc_if); 160209908Sraj bpfattach(&sc->sc_if, DLT_NULL, sizeof(u_int)); 161209908Sraj LIST_INSERT_HEAD(&lo_list, sc, sc_next); 162209908Sraj if (loif == NULL) 163209908Sraj loif = &sc->sc_if; 164209908Sraj 165209908Sraj return (0); 166209908Sraj} 167209908Sraj 168209908Srajstatic int 169209908Srajloop_modevent(module_t mod, int type, void *data) 170209908Sraj{ 171209908Sraj switch (type) { 172209908Sraj case MOD_LOAD: 173209908Sraj LIST_INIT(&lo_list); 174209908Sraj if_clone_attach(&lo_cloner); 175209908Sraj break; 176209908Sraj case MOD_UNLOAD: 177209908Sraj printf("loop module unload - not possible for this module type\n"); 178209908Sraj return EINVAL; 179209908Sraj } 180209908Sraj return 0; 181209908Sraj} 182209908Sraj 183209908Srajstatic moduledata_t loop_mod = { 184209908Sraj "loop", 185209908Sraj loop_modevent, 186209908Sraj 0 187209908Sraj}; 188209908Sraj 189209908SrajDECLARE_MODULE(loop, loop_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 190209908Sraj 191209908Srajint 192209908Srajlooutput(ifp, m, dst, rt) 193209908Sraj struct ifnet *ifp; 194209908Sraj register struct mbuf *m; 195209908Sraj struct sockaddr *dst; 196209908Sraj register struct rtentry *rt; 197209908Sraj{ 198209908Sraj if ((m->m_flags & M_PKTHDR) == 0) 199209908Sraj panic("looutput no HDR"); 200209908Sraj 201209908Sraj if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 202209908Sraj m_freem(m); 203209908Sraj return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 204209908Sraj rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 205209908Sraj } 206209908Sraj /* 207209908Sraj * KAME requires that the packet to be contiguous on the 208209908Sraj * mbuf. We need to make that sure. 209209908Sraj * this kind of code should be avoided. 210209908Sraj * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 211209908Sraj */ 212209908Sraj if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 213209908Sraj struct mbuf *n; 214209908Sraj 215209908Sraj MGETHDR(n, M_DONTWAIT, MT_HEADER); 216209908Sraj if (!n) 217209908Sraj goto contiguousfail; 218209908Sraj MCLGET(n, M_DONTWAIT); 219209908Sraj if (! (n->m_flags & M_EXT)) { 220209908Sraj m_freem(n); 221209908Sraj goto contiguousfail; 222209908Sraj } 223209908Sraj 224209908Sraj m_copydata(m, 0, m->m_pkthdr.len, mtod(n, caddr_t)); 225209908Sraj n->m_pkthdr = m->m_pkthdr; 226209908Sraj n->m_len = m->m_pkthdr.len; 227209908Sraj SLIST_INIT(&m->m_pkthdr.tags); 228209908Sraj m_freem(m); 229209908Sraj m = n; 230209908Sraj } 231209908Sraj if (0) { 232209908Srajcontiguousfail: 233209908Sraj printf("looutput: mbuf allocation failed\n"); 234209908Sraj } 235209908Sraj 236209908Sraj ifp->if_opackets++; 237209908Sraj ifp->if_obytes += m->m_pkthdr.len; 238209908Sraj#if 1 /* XXX */ 239209908Sraj switch (dst->sa_family) { 240209908Sraj case AF_INET: 241209908Sraj case AF_INET6: 242209908Sraj case AF_IPX: 243209908Sraj case AF_NS: 244209908Sraj case AF_APPLETALK: 245209908Sraj break; 246209908Sraj default: 247209908Sraj printf("looutput: af=%d unexpected\n", dst->sa_family); 248209908Sraj m_freem(m); 249209908Sraj return (EAFNOSUPPORT); 250209908Sraj } 251209908Sraj#endif 252209908Sraj return(if_simloop(ifp, m, dst->sa_family, 0)); 253209908Sraj} 254209908Sraj 255209908Sraj/* 256209908Sraj * if_simloop() 257209908Sraj * 258209908Sraj * This function is to support software emulation of hardware loopback, 259209908Sraj * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 260209908Sraj * hear their own broadcasts, we create a copy of the packet that we 261209908Sraj * would normally receive via a hardware loopback. 262209908Sraj * 263209908Sraj * This function expects the packet to include the media header of length hlen. 264209908Sraj */ 265209908Sraj 266209908Srajint 267209908Srajif_simloop(ifp, m, af, hlen) 268209908Sraj struct ifnet *ifp; 269209908Sraj struct mbuf *m; 270209908Sraj int af; 271209908Sraj int hlen; 272209908Sraj{ 273209908Sraj int isr; 274209908Sraj struct ifqueue *inq = 0; 275209908Sraj 276209908Sraj KASSERT((m->m_flags & M_PKTHDR) != 0, ("if_simloop: no HDR")); 277209908Sraj m->m_pkthdr.rcvif = ifp; 278209908Sraj 279209908Sraj /* BPF write needs to be handled specially */ 280209908Sraj if (af == AF_UNSPEC) { 281209908Sraj KASSERT(m->m_len >= sizeof(int), ("if_simloop: m_len")); 282209908Sraj af = *(mtod(m, int *)); 283209908Sraj m->m_len -= sizeof(int); 284209908Sraj m->m_pkthdr.len -= sizeof(int); 285209908Sraj m->m_data += sizeof(int); 286209908Sraj } 287209908Sraj 288209908Sraj /* Let BPF see incoming packet */ 289209908Sraj if (ifp->if_bpf) { 290209908Sraj struct mbuf m0, *n = m; 291209908Sraj 292209908Sraj if (ifp->if_bpf->bif_dlt == DLT_NULL) { 293209908Sraj /* 294209908Sraj * We need to prepend the address family as 295209908Sraj * a four byte field. Cons up a dummy header 296209908Sraj * to pacify bpf. This is safe because bpf 297209908Sraj * will only read from the mbuf (i.e., it won't 298209908Sraj * try to free it or keep a pointer a to it). 299209908Sraj */ 300209908Sraj m0.m_next = m; 301209908Sraj m0.m_len = 4; 302209908Sraj m0.m_data = (char *)⁡ 303209908Sraj n = &m0; 304209908Sraj } 305209908Sraj bpf_mtap(ifp, n); 306209908Sraj } 307209908Sraj 308209908Sraj /* Strip away media header */ 309209908Sraj if (hlen > 0) { 310209908Sraj m_adj(m, hlen); 311209908Sraj#if defined(__alpha__) || defined(__ia64__) || defined(__sparc64__) 312209908Sraj /* The alpha doesn't like unaligned data. 313209908Sraj * We move data down in the first mbuf */ 314209908Sraj if (mtod(m, vm_offset_t) & 3) { 315218050Smarcel KASSERT(hlen >= 3, ("if_simloop: hlen too small")); 316209908Sraj bcopy(m->m_data, 317209908Sraj (char *)(mtod(m, vm_offset_t) 318218050Smarcel - (mtod(m, vm_offset_t) & 3)), 319218050Smarcel m->m_len); 320218050Smarcel mtod(m,vm_offset_t) -= (mtod(m, vm_offset_t) & 3); 321218050Smarcel } 322218050Smarcel#endif 323218050Smarcel } 324209908Sraj 325209908Sraj /* Deliver to upper layer protocol */ 326209908Sraj switch (af) { 327209908Sraj#ifdef INET 328209908Sraj case AF_INET: 329209908Sraj inq = &ipintrq; 330209908Sraj isr = NETISR_IP; 331218050Smarcel break; 332218050Smarcel#endif 333209908Sraj#ifdef INET6 334218050Smarcel case AF_INET6: 335209908Sraj m->m_flags |= M_LOOP; 336 inq = &ip6intrq; 337 isr = NETISR_IPV6; 338 break; 339#endif 340#ifdef IPX 341 case AF_IPX: 342 inq = &ipxintrq; 343 isr = NETISR_IPX; 344 break; 345#endif 346#ifdef NS 347 case AF_NS: 348 inq = &nsintrq; 349 isr = NETISR_NS; 350 break; 351#endif 352#ifdef NETATALK 353 case AF_APPLETALK: 354 inq = &atintrq2; 355 isr = NETISR_ATALK; 356 break; 357#endif 358 default: 359 printf("if_simloop: can't handle af=%d\n", af); 360 m_freem(m); 361 return (EAFNOSUPPORT); 362 } 363 ifp->if_ipackets++; 364 ifp->if_ibytes += m->m_pkthdr.len; 365 (void) IF_HANDOFF(inq, m, NULL); 366 schednetisr(isr); 367 return (0); 368} 369 370/* ARGSUSED */ 371static void 372lortrequest(cmd, rt, info) 373 int cmd; 374 struct rtentry *rt; 375 struct rt_addrinfo *info; 376{ 377 if (rt) { 378 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; /* for ISO */ 379 /* 380 * For optimal performance, the send and receive buffers 381 * should be at least twice the MTU plus a little more for 382 * overhead. 383 */ 384 rt->rt_rmx.rmx_recvpipe = 385 rt->rt_rmx.rmx_sendpipe = 3 * LOMTU; 386 } 387} 388 389/* 390 * Process an ioctl request. 391 */ 392/* ARGSUSED */ 393int 394loioctl(ifp, cmd, data) 395 register struct ifnet *ifp; 396 u_long cmd; 397 caddr_t data; 398{ 399 register struct ifaddr *ifa; 400 register struct ifreq *ifr = (struct ifreq *)data; 401 register int error = 0; 402 403 switch (cmd) { 404 405 case SIOCSIFADDR: 406 ifp->if_flags |= IFF_UP | IFF_RUNNING; 407 ifa = (struct ifaddr *)data; 408 ifa->ifa_rtrequest = lortrequest; 409 /* 410 * Everything else is done at a higher level. 411 */ 412 break; 413 414 case SIOCADDMULTI: 415 case SIOCDELMULTI: 416 if (ifr == 0) { 417 error = EAFNOSUPPORT; /* XXX */ 418 break; 419 } 420 switch (ifr->ifr_addr.sa_family) { 421 422#ifdef INET 423 case AF_INET: 424 break; 425#endif 426#ifdef INET6 427 case AF_INET6: 428 break; 429#endif 430 431 default: 432 error = EAFNOSUPPORT; 433 break; 434 } 435 break; 436 437 case SIOCSIFMTU: 438 ifp->if_mtu = ifr->ifr_mtu; 439 break; 440 441 case SIOCSIFFLAGS: 442 break; 443 444 default: 445 error = EINVAL; 446 } 447 return (error); 448} 449