1 /* $NetBSD: if_loop.c,v 1.80 2014/06/07 11:00:29 rmind Exp $ */ 2 3 /* 4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 /* 33 * Copyright (c) 1982, 1986, 1993 34 * The Regents of the University of California. All rights reserved. 35 * 36 * Redistribution and use in source and binary forms, with or without 37 * modification, are permitted provided that the following conditions 38 * are met: 39 * 1. Redistributions of source code must retain the above copyright 40 * notice, this list of conditions and the following disclaimer. 41 * 2. Redistributions in binary form must reproduce the above copyright 42 * notice, this list of conditions and the following disclaimer in the 43 * documentation and/or other materials provided with the distribution. 44 * 3. Neither the name of the University nor the names of its contributors 45 * may be used to endorse or promote products derived from this software 46 * without specific prior written permission. 47 * 48 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 51 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 52 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 53 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 54 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 55 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 56 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 57 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 58 * SUCH DAMAGE. 59 * 60 * @(#)if_loop.c 8.2 (Berkeley) 1/9/95 61 */ 62 63 /* 64 * Loopback interface driver for protocol testing and timing. 65 */ 66 67 #include <sys/cdefs.h> 68 __KERNEL_RCSID(0, "$NetBSD: if_loop.c,v 1.80 2014/06/07 11:00:29 rmind Exp $"); 69 70 #include "opt_inet.h" 71 #include "opt_atalk.h" 72 #include "opt_ipx.h" 73 #include "opt_mbuftrace.h" 74 #include "opt_mpls.h" 75 76 77 #include <sys/param.h> 78 #include <sys/systm.h> 79 #include <sys/kernel.h> 80 #include <sys/mbuf.h> 81 #include <sys/socket.h> 82 #include <sys/errno.h> 83 #include <sys/ioctl.h> 84 #include <sys/time.h> 85 86 #include <sys/cpu.h> 87 88 #include <net/if.h> 89 #include <net/if_types.h> 90 #include <net/netisr.h> 91 #include <net/route.h> 92 93 #ifdef INET 94 #include <netinet/in.h> 95 #include <netinet/in_systm.h> 96 #include <netinet/in_var.h> 97 #include <netinet/in_offload.h> 98 #include <netinet/ip.h> 99 #endif 100 101 #ifdef INET6 102 #ifndef INET 103 #include <netinet/in.h> 104 #endif 105 #include <netinet6/in6_var.h> 106 #include <netinet6/in6_offload.h> 107 #include <netinet/ip6.h> 108 #endif 109 110 #ifdef IPX 111 #include <netipx/ipx.h> 112 #include <netipx/ipx_if.h> 113 #endif 114 115 #ifdef MPLS 116 #include <netmpls/mpls.h> 117 #include <netmpls/mpls_var.h> 118 #endif 119 120 #ifdef NETATALK 121 #include <netatalk/at.h> 122 #include <netatalk/at_var.h> 123 #endif 124 125 #include <net/bpf.h> 126 127 #if defined(LARGE_LOMTU) 128 #define LOMTU (131072 + MHLEN + MLEN) 129 #define LOMTU_MAX LOMTU 130 #else 131 #define LOMTU (32768 + MHLEN + MLEN) 132 #define LOMTU_MAX (65536 + MHLEN + MLEN) 133 #endif 134 135 #ifdef ALTQ 136 static void lostart(struct ifnet *); 137 #endif 138 139 static int loop_clone_create(struct if_clone *, int); 140 static int loop_clone_destroy(struct ifnet *); 141 142 static struct if_clone loop_cloner = 143 IF_CLONE_INITIALIZER("lo", loop_clone_create, loop_clone_destroy); 144 145 void 146 loopattach(int n) 147 { 148 149 (void)loop_clone_create(&loop_cloner, 0); /* lo0 always exists */ 150 if_clone_attach(&loop_cloner); 151 } 152 153 static int 154 loop_clone_create(struct if_clone *ifc, int unit) 155 { 156 struct ifnet *ifp; 157 158 ifp = if_alloc(IFT_LOOP); 159 160 if_initname(ifp, ifc->ifc_name, unit); 161 162 ifp->if_mtu = LOMTU; 163 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST | IFF_RUNNING; 164 ifp->if_ioctl = loioctl; 165 ifp->if_output = looutput; 166 #ifdef ALTQ 167 ifp->if_start = lostart; 168 #endif 169 ifp->if_type = IFT_LOOP; 170 ifp->if_hdrlen = 0; 171 ifp->if_addrlen = 0; 172 ifp->if_dlt = DLT_NULL; 173 IFQ_SET_READY(&ifp->if_snd); 174 if (unit == 0) 175 lo0ifp = ifp; 176 if_attach(ifp); 177 if_alloc_sadl(ifp); 178 bpf_attach(ifp, DLT_NULL, sizeof(u_int)); 179 #ifdef MBUFTRACE 180 ifp->if_mowner = malloc(sizeof(struct mowner), M_DEVBUF, 181 M_WAITOK | M_ZERO); 182 strlcpy(ifp->if_mowner->mo_name, ifp->if_xname, 183 sizeof(ifp->if_mowner->mo_name)); 184 MOWNER_ATTACH(ifp->if_mowner); 185 #endif 186 187 return (0); 188 } 189 190 static int 191 loop_clone_destroy(struct ifnet *ifp) 192 { 193 194 if (ifp == lo0ifp) 195 return (EPERM); 196 197 #ifdef MBUFTRACE 198 MOWNER_DETACH(ifp->if_mowner); 199 free(ifp->if_mowner, M_DEVBUF); 200 #endif 201 202 bpf_detach(ifp); 203 if_detach(ifp); 204 205 if_free(ifp); 206 207 return (0); 208 } 209 210 int 211 looutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 212 struct rtentry *rt) 213 { 214 pktqueue_t *pktq = NULL; 215 struct ifqueue *ifq = NULL; 216 int s, isr = -1; 217 int csum_flags; 218 size_t pktlen; 219 220 MCLAIM(m, ifp->if_mowner); 221 KASSERT(KERNEL_LOCKED_P()); 222 223 if ((m->m_flags & M_PKTHDR) == 0) 224 panic("looutput: no header mbuf"); 225 if (ifp->if_flags & IFF_LOOPBACK) 226 bpf_mtap_af(ifp, dst->sa_family, m); 227 m->m_pkthdr.rcvif = ifp; 228 229 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 230 m_freem(m); 231 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 232 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 233 } 234 235 pktlen = m->m_pkthdr.len; 236 ifp->if_opackets++; 237 ifp->if_obytes += pktlen; 238 239 #ifdef ALTQ 240 /* 241 * ALTQ on the loopback interface is just for debugging. It's 242 * used only for loopback interfaces, not for a simplex interface. 243 */ 244 if ((ALTQ_IS_ENABLED(&ifp->if_snd) || TBR_IS_ENABLED(&ifp->if_snd)) && 245 ifp->if_start == lostart) { 246 struct altq_pktattr pktattr; 247 int error; 248 249 /* 250 * If the queueing discipline needs packet classification, 251 * do it before prepending the link headers. 252 */ 253 IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr); 254 255 M_PREPEND(m, sizeof(uint32_t), M_DONTWAIT); 256 if (m == NULL) 257 return (ENOBUFS); 258 *(mtod(m, uint32_t *)) = dst->sa_family; 259 260 s = splnet(); 261 IFQ_ENQUEUE(&ifp->if_snd, m, &pktattr, error); 262 (*ifp->if_start)(ifp); 263 splx(s); 264 return (error); 265 } 266 #endif /* ALTQ */ 267 268 m_tag_delete_nonpersistent(m); 269 270 #ifdef MPLS 271 if (rt != NULL && rt_gettag(rt) != NULL && 272 rt_gettag(rt)->sa_family == AF_MPLS && 273 (m->m_flags & (M_MCAST | M_BCAST)) == 0) { 274 union mpls_shim msh; 275 msh.s_addr = MPLS_GETSADDR(rt); 276 if (msh.shim.label != MPLS_LABEL_IMPLNULL) { 277 ifq = &mplsintrq; 278 isr = NETISR_MPLS; 279 } 280 } 281 if (isr != NETISR_MPLS) 282 #endif 283 switch (dst->sa_family) { 284 285 #ifdef INET 286 case AF_INET: 287 csum_flags = m->m_pkthdr.csum_flags; 288 KASSERT((csum_flags & ~(M_CSUM_IPv4|M_CSUM_UDPv4)) == 0); 289 if (csum_flags != 0 && IN_LOOPBACK_NEED_CHECKSUM(csum_flags)) { 290 ip_undefer_csum(m, 0, csum_flags); 291 } 292 m->m_pkthdr.csum_flags = 0; 293 pktq = ip_pktq; 294 break; 295 #endif 296 #ifdef INET6 297 case AF_INET6: 298 csum_flags = m->m_pkthdr.csum_flags; 299 KASSERT((csum_flags & ~M_CSUM_UDPv6) == 0); 300 if (csum_flags != 0 && 301 IN6_LOOPBACK_NEED_CHECKSUM(csum_flags)) { 302 ip6_undefer_csum(m, 0, csum_flags); 303 } 304 m->m_pkthdr.csum_flags = 0; 305 m->m_flags |= M_LOOP; 306 pktq = ip6_pktq; 307 break; 308 #endif 309 #ifdef IPX 310 case AF_IPX: 311 ifq = &ipxintrq; 312 isr = NETISR_IPX; 313 break; 314 #endif 315 #ifdef NETATALK 316 case AF_APPLETALK: 317 ifq = &atintrq2; 318 isr = NETISR_ATALK; 319 break; 320 #endif 321 default: 322 printf("%s: can't handle af%d\n", ifp->if_xname, 323 dst->sa_family); 324 m_freem(m); 325 return (EAFNOSUPPORT); 326 } 327 328 s = splnet(); 329 if (__predict_true(pktq)) { 330 int error = 0; 331 332 if (__predict_true(pktq_enqueue(pktq, m, 0))) { 333 ifp->if_ipackets++; 334 ifp->if_ibytes += pktlen; 335 } else { 336 m_freem(m); 337 error = ENOBUFS; 338 } 339 splx(s); 340 return error; 341 } 342 if (IF_QFULL(ifq)) { 343 IF_DROP(ifq); 344 m_freem(m); 345 splx(s); 346 return (ENOBUFS); 347 } 348 IF_ENQUEUE(ifq, m); 349 schednetisr(isr); 350 ifp->if_ipackets++; 351 ifp->if_ibytes += m->m_pkthdr.len; 352 splx(s); 353 return (0); 354 } 355 356 #ifdef ALTQ 357 static void 358 lostart(struct ifnet *ifp) 359 { 360 for (;;) { 361 pktqueue_t *pktq = NULL; 362 struct ifqueue *ifq = NULL; 363 struct mbuf *m; 364 size_t pktlen; 365 uint32_t af; 366 int s, isr = 0; 367 368 IFQ_DEQUEUE(&ifp->if_snd, m); 369 if (m == NULL) 370 return; 371 372 af = *(mtod(m, uint32_t *)); 373 m_adj(m, sizeof(uint32_t)); 374 375 switch (af) { 376 #ifdef INET 377 case AF_INET: 378 pktq = ip_pktq; 379 break; 380 #endif 381 #ifdef INET6 382 case AF_INET6: 383 m->m_flags |= M_LOOP; 384 pktq = ip6_pktq; 385 break; 386 #endif 387 #ifdef IPX 388 case AF_IPX: 389 ifq = &ipxintrq; 390 isr = NETISR_IPX; 391 break; 392 #endif 393 #ifdef NETATALK 394 case AF_APPLETALK: 395 ifq = &atintrq2; 396 isr = NETISR_ATALK; 397 break; 398 #endif 399 default: 400 printf("%s: can't handle af%d\n", ifp->if_xname, af); 401 m_freem(m); 402 return; 403 } 404 pktlen = m->m_pkthdr.len; 405 406 s = splnet(); 407 if (__predict_true(pktq)) { 408 if (__predict_false(pktq_enqueue(pktq, m, 0))) { 409 m_freem(m); 410 splx(s); 411 return; 412 } 413 ifp->if_ipackets++; 414 ifp->if_ibytes += pktlen; 415 splx(s); 416 continue; 417 } 418 if (IF_QFULL(ifq)) { 419 IF_DROP(ifq); 420 splx(s); 421 m_freem(m); 422 return; 423 } 424 IF_ENQUEUE(ifq, m); 425 schednetisr(isr); 426 ifp->if_ipackets++; 427 ifp->if_ibytes += pktlen; 428 splx(s); 429 } 430 } 431 #endif /* ALTQ */ 432 433 /* ARGSUSED */ 434 void 435 lortrequest(int cmd, struct rtentry *rt, 436 const struct rt_addrinfo *info) 437 { 438 439 if (rt) 440 rt->rt_rmx.rmx_mtu = lo0ifp->if_mtu; 441 } 442 443 /* 444 * Process an ioctl request. 445 */ 446 /* ARGSUSED */ 447 int 448 loioctl(struct ifnet *ifp, u_long cmd, void *data) 449 { 450 struct ifaddr *ifa; 451 struct ifreq *ifr = data; 452 int error = 0; 453 454 switch (cmd) { 455 456 case SIOCINITIFADDR: 457 ifp->if_flags |= IFF_UP; 458 ifa = (struct ifaddr *)data; 459 if (ifa != NULL) 460 ifa->ifa_rtrequest = lortrequest; 461 /* 462 * Everything else is done at a higher level. 463 */ 464 break; 465 466 case SIOCSIFMTU: 467 if ((unsigned)ifr->ifr_mtu > LOMTU_MAX) 468 error = EINVAL; 469 else if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET){ 470 error = 0; 471 } 472 break; 473 474 case SIOCADDMULTI: 475 case SIOCDELMULTI: 476 if (ifr == NULL) { 477 error = EAFNOSUPPORT; /* XXX */ 478 break; 479 } 480 switch (ifreq_getaddr(cmd, ifr)->sa_family) { 481 482 #ifdef INET 483 case AF_INET: 484 break; 485 #endif 486 #ifdef INET6 487 case AF_INET6: 488 break; 489 #endif 490 491 default: 492 error = EAFNOSUPPORT; 493 break; 494 } 495 break; 496 497 default: 498 error = ifioctl_common(ifp, cmd, data); 499 } 500 return (error); 501 } 502