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 62 #ifdef INET 63 #include <netinet/in.h> 64 #include <netinet/in_var.h> 65 #endif 66 67 #ifdef IPX 68 #include <netipx/ipx.h> 69 #include <netipx/ipx_if.h> 70 #endif 71 72 #ifdef INET6 73 #ifndef INET 74 #include <netinet/in.h> 75 #endif 76 #include <netinet6/in6_var.h> 77 #include <netinet/ip6.h> 78 #endif 79 80 #ifdef NS 81 #include <netns/ns.h> 82 #include <netns/ns_if.h> 83 #endif 84 85 #ifdef NETATALK 86 #include <netatalk/at.h> 87 #include <netatalk/at_var.h> 88 #endif NETATALK 89 90 int loioctl __P((struct ifnet *, u_long, caddr_t)); 91 static void lortrequest __P((int, struct rtentry *, struct sockaddr *)); 92 93 int looutput __P((struct ifnet *ifp, 94 struct mbuf *m, struct sockaddr *dst, struct rtentry *rt)); 95 96 #ifdef TINY_LOMTU 97 #define LOMTU (1024+512) 98 #elif defined(LARGE_LOMTU) 99 #define LOMTU 131072 100 #else 101 #define LOMTU 16384 102 #endif 103 104 static int nloop; 105 106 struct ifnet *loif; /* Used externally */ 107 108 static MALLOC_DEFINE(M_LO, "lo", "Loopback Interface"); 109 110 struct lo_softc { 111 struct ifnet sc_if; /* network-visible interface */ 112 LIST_ENTRY(lo_softc) sc_next; 113 }; 114 static LIST_HEAD(lo_list, lo_softc) lo_list; 115 116 static void 117 locreate(int unit) 118 { 119 struct lo_softc *sc; 120 121 MALLOC(sc, struct lo_softc *, sizeof(*sc), M_LO, M_WAITOK | M_ZERO); 122 123 sc->sc_if.if_name = "lo"; 124 sc->sc_if.if_unit = unit; 125 sc->sc_if.if_mtu = LOMTU; 126 sc->sc_if.if_flags = IFF_LOOPBACK | IFF_MULTICAST; 127 sc->sc_if.if_ioctl = loioctl; 128 sc->sc_if.if_output = looutput; 129 sc->sc_if.if_type = IFT_LOOP; 130 sc->sc_if.if_snd.ifq_maxlen = ifqmaxlen; 131 if_attach(&sc->sc_if); 132 bpfattach(&sc->sc_if, DLT_NULL, sizeof(u_int)); 133 LIST_INSERT_HEAD(&lo_list, sc, sc_next); 134 if (loif == NULL) 135 loif = &sc->sc_if; 136 } 137 138 static void 139 lodestroy(struct lo_softc *sc) 140 { 141 bpfdetach(&sc->sc_if); 142 if_detach(&sc->sc_if); 143 LIST_REMOVE(sc, sc_next); 144 FREE(sc, M_LO); 145 } 146 147 148 static int 149 sysctl_net_nloop(SYSCTL_HANDLER_ARGS) 150 { 151 int newnloop; 152 int error; 153 154 newnloop = nloop; 155 156 error = sysctl_handle_opaque(oidp, &newnloop, sizeof newnloop, req); 157 if (error || !req->newptr) 158 return (error); 159 160 if (newnloop < 1) 161 return (EINVAL); 162 while (newnloop > nloop) { 163 locreate(nloop); 164 nloop++; 165 } 166 while (newnloop < nloop) { 167 lodestroy(LIST_FIRST(&lo_list)); 168 nloop--; 169 } 170 return (0); 171 } 172 SYSCTL_PROC(_net, OID_AUTO, nloop, CTLTYPE_INT | CTLFLAG_RW, 173 0, 0, sysctl_net_nloop, "I", ""); 174 175 static int 176 loop_modevent(module_t mod, int type, void *data) 177 { 178 int i; 179 180 switch (type) { 181 case MOD_LOAD: 182 TUNABLE_INT_FETCH("net.nloop", 1, nloop); 183 if (nloop < 1) /* sanity check */ 184 nloop = 1; 185 for (i = 0; i < nloop; i++) 186 locreate(i); 187 break; 188 case MOD_UNLOAD: 189 printf("loop module unload - not possible for this module type\n"); 190 return EINVAL; 191 } 192 return 0; 193 } 194 195 static moduledata_t loop_mod = { 196 "loop", 197 loop_modevent, 198 0 199 }; 200 201 DECLARE_MODULE(loop, loop_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 202 203 int 204 looutput(ifp, m, dst, rt) 205 struct ifnet *ifp; 206 register struct mbuf *m; 207 struct sockaddr *dst; 208 register struct rtentry *rt; 209 { 210 if ((m->m_flags & M_PKTHDR) == 0) 211 panic("looutput no HDR"); 212 213 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 214 m_freem(m); 215 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 216 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 217 } 218 /* 219 * KAME requires that the packet to be contiguous on the 220 * mbuf. We need to make that sure. 221 * this kind of code should be avoided. 222 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 223 */ 224 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 225 struct mbuf *n; 226 227 MGETHDR(n, M_DONTWAIT, MT_HEADER); 228 if (!n) 229 goto contiguousfail; 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, m->m_pkthdr.len, mtod(n, caddr_t)); 237 n->m_pkthdr = m->m_pkthdr; 238 n->m_len = m->m_pkthdr.len; 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 register 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 /* 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 bpf_mtap(ifp, n); 315 } 316 317 /* Strip away media header */ 318 if (hlen > 0) { 319 m_adj(m, hlen); 320 #ifdef __alpha__ 321 /* The alpha doesn't like unaligned data. 322 * We move data down in the first mbuf */ 323 if (mtod(m, vm_offset_t) & 3) { 324 KASSERT(hlen >= 3, ("if_simloop: hlen too small")); 325 bcopy(m->m_data, 326 (char *)(mtod(m, vm_offset_t) 327 - (mtod(m, vm_offset_t) & 3)), 328 m->m_len); 329 mtod(m,vm_offset_t) -= (mtod(m, vm_offset_t) & 3); 330 } 331 #endif 332 } 333 334 /* Deliver to upper layer protocol */ 335 switch (af) { 336 #ifdef INET 337 case AF_INET: 338 inq = &ipintrq; 339 isr = NETISR_IP; 340 break; 341 #endif 342 #ifdef INET6 343 case AF_INET6: 344 m->m_flags |= M_LOOP; 345 inq = &ip6intrq; 346 isr = NETISR_IPV6; 347 break; 348 #endif 349 #ifdef IPX 350 case AF_IPX: 351 inq = &ipxintrq; 352 isr = NETISR_IPX; 353 break; 354 #endif 355 #ifdef NS 356 case AF_NS: 357 inq = &nsintrq; 358 isr = NETISR_NS; 359 break; 360 #endif 361 #ifdef NETATALK 362 case AF_APPLETALK: 363 inq = &atintrq2; 364 isr = NETISR_ATALK; 365 break; 366 #endif NETATALK 367 default: 368 printf("if_simloop: can't handle af=%d\n", af); 369 m_freem(m); 370 return (EAFNOSUPPORT); 371 } 372 ifp->if_ipackets++; 373 ifp->if_ibytes += m->m_pkthdr.len; 374 (void) IF_HANDOFF(inq, m, NULL); 375 schednetisr(isr); 376 return (0); 377 } 378 379 /* ARGSUSED */ 380 static void 381 lortrequest(cmd, rt, sa) 382 int cmd; 383 struct rtentry *rt; 384 struct sockaddr *sa; 385 { 386 if (rt) { 387 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; /* for ISO */ 388 /* 389 * For optimal performance, the send and receive buffers 390 * should be at least twice the MTU plus a little more for 391 * overhead. 392 */ 393 rt->rt_rmx.rmx_recvpipe = 394 rt->rt_rmx.rmx_sendpipe = 3 * LOMTU; 395 } 396 } 397 398 /* 399 * Process an ioctl request. 400 */ 401 /* ARGSUSED */ 402 int 403 loioctl(ifp, cmd, data) 404 register struct ifnet *ifp; 405 u_long cmd; 406 caddr_t data; 407 { 408 register struct ifaddr *ifa; 409 register struct ifreq *ifr = (struct ifreq *)data; 410 register int error = 0; 411 412 switch (cmd) { 413 414 case SIOCSIFADDR: 415 ifp->if_flags |= IFF_UP | IFF_RUNNING; 416 ifa = (struct ifaddr *)data; 417 ifa->ifa_rtrequest = lortrequest; 418 /* 419 * Everything else is done at a higher level. 420 */ 421 break; 422 423 case SIOCADDMULTI: 424 case SIOCDELMULTI: 425 if (ifr == 0) { 426 error = EAFNOSUPPORT; /* XXX */ 427 break; 428 } 429 switch (ifr->ifr_addr.sa_family) { 430 431 #ifdef INET 432 case AF_INET: 433 break; 434 #endif 435 #ifdef INET6 436 case AF_INET6: 437 break; 438 #endif 439 440 default: 441 error = EAFNOSUPPORT; 442 break; 443 } 444 break; 445 446 case SIOCSIFMTU: 447 ifp->if_mtu = ifr->ifr_mtu; 448 break; 449 450 case SIOCSIFFLAGS: 451 break; 452 453 default: 454 error = EINVAL; 455 } 456 return (error); 457 } 458