if_loop.c revision 1.109
1 /* $NetBSD: if_loop.c,v 1.109 2019/11/14 04:14:30 msaitoh 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 1.109 2019/11/14 04:14:30 msaitoh 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_chain(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 in_undefer_cksum(m, 0, csum_flags); 324 m->m_pkthdr.csum_flags = 0; 325 } else { 326 /* 327 * Do nothing. Pass M_CSUM_IPv4 and M_CSUM_UDPv4 as 328 * they are to tell those are calculated and good. 329 */ 330 } 331 pktq = ip_pktq; 332 break; 333 #endif 334 #ifdef INET6 335 case AF_INET6: 336 csum_flags = m->m_pkthdr.csum_flags; 337 KASSERT((csum_flags & ~M_CSUM_UDPv6) == 0); 338 if (csum_flags != 0 && 339 IN6_LOOPBACK_NEED_CHECKSUM(csum_flags)) { 340 in6_undefer_cksum(m, 0, csum_flags); 341 m->m_pkthdr.csum_flags = 0; 342 } else { 343 /* 344 * Do nothing. Pass M_CSUM_UDPv6 as 345 * they are to tell those are calculated and good. 346 */ 347 } 348 m->m_flags |= M_LOOP; 349 pktq = ip6_pktq; 350 break; 351 #endif 352 #ifdef NETATALK 353 case AF_APPLETALK: 354 ifq = &atintrq2; 355 isr = NETISR_ATALK; 356 break; 357 #endif 358 default: 359 printf("%s: can't handle af%d\n", ifp->if_xname, 360 dst->sa_family); 361 m_freem(m); 362 error = EAFNOSUPPORT; 363 goto out; 364 } 365 366 s = splnet(); 367 if (__predict_true(pktq)) { 368 error = 0; 369 370 if (__predict_true(pktq_enqueue(pktq, m, 0))) { 371 ifp->if_ipackets++; 372 ifp->if_ibytes += pktlen; 373 } else { 374 m_freem(m); 375 error = ENOBUFS; 376 } 377 splx(s); 378 goto out; 379 } 380 if (IF_QFULL(ifq)) { 381 IF_DROP(ifq); 382 m_freem(m); 383 splx(s); 384 error = ENOBUFS; 385 goto out; 386 } 387 ifp->if_ipackets++; 388 ifp->if_ibytes += m->m_pkthdr.len; 389 IF_ENQUEUE(ifq, m); 390 schednetisr(isr); 391 splx(s); 392 out: 393 KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 394 return error; 395 } 396 397 #ifdef ALTQ 398 static void 399 lostart(struct ifnet *ifp) 400 { 401 for (;;) { 402 pktqueue_t *pktq = NULL; 403 struct ifqueue *ifq = NULL; 404 struct mbuf *m; 405 size_t pktlen; 406 uint32_t af; 407 int s, isr = 0; 408 409 IFQ_DEQUEUE(&ifp->if_snd, m); 410 if (m == NULL) 411 return; 412 413 af = *(mtod(m, uint32_t *)); 414 m_adj(m, sizeof(uint32_t)); 415 416 switch (af) { 417 #ifdef INET 418 case AF_INET: 419 pktq = ip_pktq; 420 break; 421 #endif 422 #ifdef INET6 423 case AF_INET6: 424 m->m_flags |= M_LOOP; 425 pktq = ip6_pktq; 426 break; 427 #endif 428 #ifdef NETATALK 429 case AF_APPLETALK: 430 ifq = &atintrq2; 431 isr = NETISR_ATALK; 432 break; 433 #endif 434 default: 435 printf("%s: can't handle af%d\n", ifp->if_xname, af); 436 m_freem(m); 437 return; 438 } 439 pktlen = m->m_pkthdr.len; 440 441 s = splnet(); 442 if (__predict_true(pktq)) { 443 if (__predict_false(pktq_enqueue(pktq, m, 0))) { 444 m_freem(m); 445 splx(s); 446 return; 447 } 448 ifp->if_ipackets++; 449 ifp->if_ibytes += pktlen; 450 splx(s); 451 continue; 452 } 453 if (IF_QFULL(ifq)) { 454 IF_DROP(ifq); 455 splx(s); 456 m_freem(m); 457 return; 458 } 459 IF_ENQUEUE(ifq, m); 460 schednetisr(isr); 461 ifp->if_ipackets++; 462 ifp->if_ibytes += pktlen; 463 splx(s); 464 } 465 } 466 #endif /* ALTQ */ 467 468 /* ARGSUSED */ 469 static void 470 loop_rtrequest(int cmd, struct rtentry *rt, 471 const struct rt_addrinfo *info) 472 { 473 474 if (rt) 475 rt->rt_rmx.rmx_mtu = lo0ifp->if_mtu; 476 } 477 478 /* 479 * Process an ioctl request. 480 */ 481 /* ARGSUSED */ 482 int 483 loioctl(struct ifnet *ifp, u_long cmd, void *data) 484 { 485 struct ifaddr *ifa; 486 struct ifreq *ifr = data; 487 int error = 0; 488 489 switch (cmd) { 490 491 case SIOCINITIFADDR: 492 ifp->if_flags |= IFF_UP; 493 ifa = (struct ifaddr *)data; 494 if (ifa != NULL) 495 ifa->ifa_rtrequest = loop_rtrequest; 496 /* 497 * Everything else is done at a higher level. 498 */ 499 break; 500 501 case SIOCSIFMTU: 502 if ((unsigned)ifr->ifr_mtu > LOMTU_MAX) 503 error = EINVAL; 504 else if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET){ 505 error = 0; 506 } 507 break; 508 509 case SIOCADDMULTI: 510 case SIOCDELMULTI: 511 if (ifr == NULL) { 512 error = EAFNOSUPPORT; /* XXX */ 513 break; 514 } 515 switch (ifreq_getaddr(cmd, ifr)->sa_family) { 516 517 #ifdef INET 518 case AF_INET: 519 break; 520 #endif 521 #ifdef INET6 522 case AF_INET6: 523 break; 524 #endif 525 526 default: 527 error = EAFNOSUPPORT; 528 break; 529 } 530 break; 531 532 default: 533 error = ifioctl_common(ifp, cmd, data); 534 } 535 return (error); 536 } 537 538 /* 539 * Module infrastructure 540 */ 541 #include "if_module.h" 542 543 IF_MODULE(MODULE_CLASS_DRIVER, loop, NULL) 544
Indexes created Tue Sep 23 07:09:52 GMT 2025