if_loop.c revision 1.103
1 /* $NetBSD: if_loop.c,v 1.103 2018/06/28 06:02:24 ozaki-r 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 1.103 2018/06/28 06:02:24 ozaki-r Exp $"); 69 70 #ifdef _KERNEL_OPT 71 #include "opt_inet.h" 72 #include "opt_atalk.h" 73 #include "opt_mbuftrace.h" 74 #include "opt_mpls.h" 75 #include "opt_net_mpsafe.h" 76 #endif 77 78 #include <sys/param.h> 79 #include <sys/systm.h> 80 #include <sys/kernel.h> 81 #include <sys/mbuf.h> 82 #include <sys/socket.h> 83 #include <sys/errno.h> 84 #include <sys/ioctl.h> 85 #include <sys/time.h> 86 #include <sys/device.h> 87 #include <sys/module.h> 88 89 #include <sys/cpu.h> 90 91 #include <net/if.h> 92 #include <net/if_types.h> 93 #include <net/netisr.h> 94 #include <net/route.h> 95 96 #ifdef INET 97 #include <netinet/in.h> 98 #include <netinet/in_systm.h> 99 #include <netinet/in_var.h> 100 #include <netinet/in_offload.h> 101 #include <netinet/ip.h> 102 #endif 103 104 #ifdef INET6 105 #ifndef INET 106 #include <netinet/in.h> 107 #endif 108 #include <netinet6/in6_var.h> 109 #include <netinet6/in6_offload.h> 110 #include <netinet/ip6.h> 111 #endif 112 113 #ifdef MPLS 114 #include <netmpls/mpls.h> 115 #include <netmpls/mpls_var.h> 116 #endif 117 118 #ifdef NETATALK 119 #include <netatalk/at.h> 120 #include <netatalk/at_var.h> 121 #endif 122 123 #include <net/bpf.h> 124 125 #if defined(LARGE_LOMTU) 126 #define LOMTU (131072 + MHLEN + MLEN) 127 #define LOMTU_MAX LOMTU 128 #else 129 #define LOMTU (32768 + MHLEN + MLEN) 130 #define LOMTU_MAX (65536 + MHLEN + MLEN) 131 #endif 132 133 #ifdef ALTQ 134 static void lostart(struct ifnet *); 135 #endif 136 137 static int loop_clone_create(struct if_clone *, int); 138 static int loop_clone_destroy(struct ifnet *); 139 140 static void loop_rtrequest(int, struct rtentry *, const struct rt_addrinfo *); 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 #ifndef _MODULE 150 loop_clone_create(&loop_cloner, 0); /* lo0 always exists */ 151 #endif 152 } 153 154 void 155 loopinit(void) 156 { 157 158 if (lo0ifp != NULL) /* can happen in rump kernel */ 159 return; 160 161 #ifdef _MODULE 162 loop_clone_create(&loop_cloner, 0); /* lo0 always exists */ 163 #endif 164 if_clone_attach(&loop_cloner); 165 } 166 167 static int 168 loopdetach(void) 169 { 170 /* no detach for now; we don't allow lo0 to be deleted */ 171 return EBUSY; 172 } 173 174 static int 175 loop_clone_create(struct if_clone *ifc, int unit) 176 { 177 struct ifnet *ifp; 178 int rv; 179 180 ifp = if_alloc(IFT_LOOP); 181 182 if_initname(ifp, ifc->ifc_name, unit); 183 184 ifp->if_mtu = LOMTU; 185 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 186 ifp->if_extflags = IFEF_NO_LINK_STATE_CHANGE; 187 #ifdef NET_MPSAFE 188 ifp->if_extflags |= IFEF_MPSAFE; 189 #endif 190 ifp->if_ioctl = loioctl; 191 ifp->if_output = looutput; 192 #ifdef ALTQ 193 ifp->if_start = lostart; 194 #endif 195 ifp->if_type = IFT_LOOP; 196 ifp->if_hdrlen = 0; 197 ifp->if_addrlen = 0; 198 ifp->if_dlt = DLT_NULL; 199 IFQ_SET_READY(&ifp->if_snd); 200 if (unit == 0) 201 lo0ifp = ifp; 202 rv = if_attach(ifp); 203 if (rv != 0) { 204 if_free(ifp); 205 return rv; 206 } 207 if_alloc_sadl(ifp); 208 bpf_attach(ifp, DLT_NULL, sizeof(u_int)); 209 #ifdef MBUFTRACE 210 ifp->if_mowner = malloc(sizeof(struct mowner), M_DEVBUF, 211 M_WAITOK | M_ZERO); 212 strlcpy(ifp->if_mowner->mo_name, ifp->if_xname, 213 sizeof(ifp->if_mowner->mo_name)); 214 MOWNER_ATTACH(ifp->if_mowner); 215 #endif 216 217 ifp->if_flags |= IFF_RUNNING; 218 219 return (0); 220 } 221 222 static int 223 loop_clone_destroy(struct ifnet *ifp) 224 { 225 226 if (ifp == lo0ifp) 227 return (EPERM); 228 229 ifp->if_flags &= ~IFF_RUNNING; 230 231 #ifdef MBUFTRACE 232 MOWNER_DETACH(ifp->if_mowner); 233 free(ifp->if_mowner, M_DEVBUF); 234 #endif 235 236 bpf_detach(ifp); 237 if_detach(ifp); 238 239 if_free(ifp); 240 241 return (0); 242 } 243 244 int 245 looutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 246 const struct rtentry *rt) 247 { 248 pktqueue_t *pktq = NULL; 249 struct ifqueue *ifq = NULL; 250 int s, isr = -1; 251 int csum_flags; 252 int error = 0; 253 size_t pktlen; 254 255 MCLAIM(m, ifp->if_mowner); 256 257 KERNEL_LOCK_UNLESS_NET_MPSAFE(); 258 259 if ((m->m_flags & M_PKTHDR) == 0) 260 panic("looutput: no header mbuf"); 261 if (ifp->if_flags & IFF_LOOPBACK) 262 bpf_mtap_af(ifp, dst->sa_family, m, BPF_D_OUT); 263 m_set_rcvif(m, ifp); 264 265 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 266 m_freem(m); 267 error = (rt->rt_flags & RTF_BLACKHOLE ? 0 : 268 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 269 goto out; 270 } 271 272 pktlen = m->m_pkthdr.len; 273 ifp->if_opackets++; 274 ifp->if_obytes += pktlen; 275 276 #ifdef ALTQ 277 /* 278 * ALTQ on the loopback interface is just for debugging. It's 279 * used only for loopback interfaces, not for a simplex interface. 280 */ 281 if ((ALTQ_IS_ENABLED(&ifp->if_snd) || TBR_IS_ENABLED(&ifp->if_snd)) && 282 ifp->if_start == lostart) { 283 /* 284 * If the queueing discipline needs packet classification, 285 * do it before prepending the link headers. 286 */ 287 IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family); 288 289 M_PREPEND(m, sizeof(uint32_t), M_DONTWAIT); 290 if (m == NULL) { 291 error = ENOBUFS; 292 goto out; 293 } 294 *(mtod(m, uint32_t *)) = dst->sa_family; 295 296 error = if_transmit_lock(ifp, m); 297 goto out; 298 } 299 #endif /* ALTQ */ 300 301 m_tag_delete_nonpersistent(m); 302 303 #ifdef MPLS 304 if (rt != NULL && rt_gettag(rt) != NULL && 305 rt_gettag(rt)->sa_family == AF_MPLS && 306 (m->m_flags & (M_MCAST | M_BCAST)) == 0) { 307 union mpls_shim msh; 308 msh.s_addr = MPLS_GETSADDR(rt); 309 if (msh.shim.label != MPLS_LABEL_IMPLNULL) { 310 ifq = &mplsintrq; 311 isr = NETISR_MPLS; 312 } 313 } 314 if (isr != NETISR_MPLS) 315 #endif 316 switch (dst->sa_family) { 317 318 #ifdef INET 319 case AF_INET: 320 csum_flags = m->m_pkthdr.csum_flags; 321 KASSERT((csum_flags & ~(M_CSUM_IPv4|M_CSUM_UDPv4)) == 0); 322 if (csum_flags != 0 && IN_LOOPBACK_NEED_CHECKSUM(csum_flags)) { 323 ip_undefer_csum(m, 0, csum_flags); 324 } 325 m->m_pkthdr.csum_flags = 0; 326 pktq = ip_pktq; 327 break; 328 #endif 329 #ifdef INET6 330 case AF_INET6: 331 csum_flags = m->m_pkthdr.csum_flags; 332 KASSERT((csum_flags & ~M_CSUM_UDPv6) == 0); 333 if (csum_flags != 0 && 334 IN6_LOOPBACK_NEED_CHECKSUM(csum_flags)) { 335 ip6_undefer_csum(m, 0, csum_flags); 336 } 337 m->m_pkthdr.csum_flags = 0; 338 m->m_flags |= M_LOOP; 339 pktq = ip6_pktq; 340 break; 341 #endif 342 #ifdef NETATALK 343 case AF_APPLETALK: 344 ifq = &atintrq2; 345 isr = NETISR_ATALK; 346 break; 347 #endif 348 default: 349 printf("%s: can't handle af%d\n", ifp->if_xname, 350 dst->sa_family); 351 m_freem(m); 352 error = EAFNOSUPPORT; 353 goto out; 354 } 355 356 s = splnet(); 357 if (__predict_true(pktq)) { 358 error = 0; 359 360 if (__predict_true(pktq_enqueue(pktq, m, 0))) { 361 ifp->if_ipackets++; 362 ifp->if_ibytes += pktlen; 363 } else { 364 m_freem(m); 365 error = ENOBUFS; 366 } 367 splx(s); 368 goto out; 369 } 370 if (IF_QFULL(ifq)) { 371 IF_DROP(ifq); 372 m_freem(m); 373 splx(s); 374 error = ENOBUFS; 375 goto out; 376 } 377 ifp->if_ipackets++; 378 ifp->if_ibytes += m->m_pkthdr.len; 379 IF_ENQUEUE(ifq, m); 380 schednetisr(isr); 381 splx(s); 382 out: 383 KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 384 return error; 385 } 386 387 #ifdef ALTQ 388 static void 389 lostart(struct ifnet *ifp) 390 { 391 for (;;) { 392 pktqueue_t *pktq = NULL; 393 struct ifqueue *ifq = NULL; 394 struct mbuf *m; 395 size_t pktlen; 396 uint32_t af; 397 int s, isr = 0; 398 399 IFQ_DEQUEUE(&ifp->if_snd, m); 400 if (m == NULL) 401 return; 402 403 af = *(mtod(m, uint32_t *)); 404 m_adj(m, sizeof(uint32_t)); 405 406 switch (af) { 407 #ifdef INET 408 case AF_INET: 409 pktq = ip_pktq; 410 break; 411 #endif 412 #ifdef INET6 413 case AF_INET6: 414 m->m_flags |= M_LOOP; 415 pktq = ip6_pktq; 416 break; 417 #endif 418 #ifdef NETATALK 419 case AF_APPLETALK: 420 ifq = &atintrq2; 421 isr = NETISR_ATALK; 422 break; 423 #endif 424 default: 425 printf("%s: can't handle af%d\n", ifp->if_xname, af); 426 m_freem(m); 427 return; 428 } 429 pktlen = m->m_pkthdr.len; 430 431 s = splnet(); 432 if (__predict_true(pktq)) { 433 if (__predict_false(pktq_enqueue(pktq, m, 0))) { 434 m_freem(m); 435 splx(s); 436 return; 437 } 438 ifp->if_ipackets++; 439 ifp->if_ibytes += pktlen; 440 splx(s); 441 continue; 442 } 443 if (IF_QFULL(ifq)) { 444 IF_DROP(ifq); 445 splx(s); 446 m_freem(m); 447 return; 448 } 449 IF_ENQUEUE(ifq, m); 450 schednetisr(isr); 451 ifp->if_ipackets++; 452 ifp->if_ibytes += pktlen; 453 splx(s); 454 } 455 } 456 #endif /* ALTQ */ 457 458 /* ARGSUSED */ 459 static void 460 loop_rtrequest(int cmd, struct rtentry *rt, 461 const struct rt_addrinfo *info) 462 { 463 464 if (rt) 465 rt->rt_rmx.rmx_mtu = lo0ifp->if_mtu; 466 } 467 468 /* 469 * Process an ioctl request. 470 */ 471 /* ARGSUSED */ 472 int 473 loioctl(struct ifnet *ifp, u_long cmd, void *data) 474 { 475 struct ifaddr *ifa; 476 struct ifreq *ifr = data; 477 int error = 0; 478 479 switch (cmd) { 480 481 case SIOCINITIFADDR: 482 ifp->if_flags |= IFF_UP; 483 ifa = (struct ifaddr *)data; 484 if (ifa != NULL) 485 ifa->ifa_rtrequest = loop_rtrequest; 486 /* 487 * Everything else is done at a higher level. 488 */ 489 break; 490 491 case SIOCSIFMTU: 492 if ((unsigned)ifr->ifr_mtu > LOMTU_MAX) 493 error = EINVAL; 494 else if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET){ 495 error = 0; 496 } 497 break; 498 499 case SIOCADDMULTI: 500 case SIOCDELMULTI: 501 if (ifr == NULL) { 502 error = EAFNOSUPPORT; /* XXX */ 503 break; 504 } 505 switch (ifreq_getaddr(cmd, ifr)->sa_family) { 506 507 #ifdef INET 508 case AF_INET: 509 break; 510 #endif 511 #ifdef INET6 512 case AF_INET6: 513 break; 514 #endif 515 516 default: 517 error = EAFNOSUPPORT; 518 break; 519 } 520 break; 521 522 default: 523 error = ifioctl_common(ifp, cmd, data); 524 } 525 return (error); 526 } 527 528 /* 529 * Module infrastructure 530 */ 531 #include "if_module.h" 532 533 IF_MODULE(MODULE_CLASS_DRIVER, loop, "") 534
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