if_loop.c revision 1.111
1 /* $NetBSD: if_loop.c,v 1.111 2020/10/14 15:55:49 roy 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 1.111 2020/10/14 15:55:49 roy 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 #ifdef NET_MPSAFE 187 ifp->if_extflags = IFEF_MPSAFE; 188 #endif 189 ifp->if_ioctl = loioctl; 190 ifp->if_output = looutput; 191 #ifdef ALTQ 192 ifp->if_start = lostart; 193 #endif 194 ifp->if_type = IFT_LOOP; 195 ifp->if_hdrlen = 0; 196 ifp->if_addrlen = 0; 197 ifp->if_dlt = DLT_NULL; 198 IFQ_SET_READY(&ifp->if_snd); 199 if (unit == 0) 200 lo0ifp = ifp; 201 rv = if_initialize(ifp); 202 if (rv != 0) { 203 if_free(ifp); 204 return rv; 205 } 206 if_alloc_sadl(ifp); 207 bpf_attach(ifp, DLT_NULL, sizeof(u_int)); 208 #ifdef MBUFTRACE 209 ifp->if_mowner = malloc(sizeof(struct mowner), M_DEVBUF, 210 M_WAITOK | M_ZERO); 211 strlcpy(ifp->if_mowner->mo_name, ifp->if_xname, 212 sizeof(ifp->if_mowner->mo_name)); 213 MOWNER_ATTACH(ifp->if_mowner); 214 #endif 215 216 ifp->if_flags |= IFF_RUNNING; 217 ifp->if_link_state = LINK_STATE_UP; 218 if_register(ifp); 219 220 return (0); 221 } 222 223 static int 224 loop_clone_destroy(struct ifnet *ifp) 225 { 226 227 if (ifp == lo0ifp) 228 return (EPERM); 229 230 ifp->if_flags &= ~IFF_RUNNING; 231 232 #ifdef MBUFTRACE 233 MOWNER_DETACH(ifp->if_mowner); 234 free(ifp->if_mowner, M_DEVBUF); 235 #endif 236 237 bpf_detach(ifp); 238 if_detach(ifp); 239 240 if_free(ifp); 241 242 return (0); 243 } 244 245 int 246 looutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 247 const struct rtentry *rt) 248 { 249 pktqueue_t *pktq = NULL; 250 struct ifqueue *ifq = NULL; 251 int s, isr = -1; 252 int csum_flags; 253 int error = 0; 254 size_t pktlen; 255 256 MCLAIM(m, ifp->if_mowner); 257 258 KERNEL_LOCK_UNLESS_NET_MPSAFE(); 259 260 if ((m->m_flags & M_PKTHDR) == 0) 261 panic("looutput: no header mbuf"); 262 if (ifp->if_flags & IFF_LOOPBACK) 263 bpf_mtap_af(ifp, dst->sa_family, m, BPF_D_OUT); 264 m_set_rcvif(m, ifp); 265 266 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 267 m_freem(m); 268 error = (rt->rt_flags & RTF_BLACKHOLE ? 0 : 269 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 270 goto out; 271 } 272 273 pktlen = m->m_pkthdr.len; 274 275 if_statadd2(ifp, if_opackets, 1, if_obytes, pktlen); 276 277 #ifdef ALTQ 278 /* 279 * ALTQ on the loopback interface is just for debugging. It's 280 * used only for loopback interfaces, not for a simplex interface. 281 */ 282 if ((ALTQ_IS_ENABLED(&ifp->if_snd) || TBR_IS_ENABLED(&ifp->if_snd)) && 283 ifp->if_start == lostart) { 284 /* 285 * If the queueing discipline needs packet classification, 286 * do it before prepending the link headers. 287 */ 288 IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family); 289 290 M_PREPEND(m, sizeof(uint32_t), M_DONTWAIT); 291 if (m == NULL) { 292 error = ENOBUFS; 293 goto out; 294 } 295 *(mtod(m, uint32_t *)) = dst->sa_family; 296 297 error = if_transmit_lock(ifp, m); 298 goto out; 299 } 300 #endif /* ALTQ */ 301 302 m_tag_delete_chain(m); 303 304 #ifdef MPLS 305 if (rt != NULL && rt_gettag(rt) != NULL && 306 rt_gettag(rt)->sa_family == AF_MPLS && 307 (m->m_flags & (M_MCAST | M_BCAST)) == 0) { 308 union mpls_shim msh; 309 msh.s_addr = MPLS_GETSADDR(rt); 310 if (msh.shim.label != MPLS_LABEL_IMPLNULL) { 311 ifq = &mplsintrq; 312 isr = NETISR_MPLS; 313 } 314 } 315 if (isr != NETISR_MPLS) 316 #endif 317 switch (dst->sa_family) { 318 319 #ifdef INET 320 case AF_INET: 321 csum_flags = m->m_pkthdr.csum_flags; 322 KASSERT((csum_flags & ~(M_CSUM_IPv4|M_CSUM_UDPv4)) == 0); 323 if (csum_flags != 0 && IN_LOOPBACK_NEED_CHECKSUM(csum_flags)) { 324 in_undefer_cksum(m, 0, csum_flags); 325 m->m_pkthdr.csum_flags = 0; 326 } else { 327 /* 328 * Do nothing. Pass M_CSUM_IPv4 and M_CSUM_UDPv4 as 329 * they are to tell those are calculated and good. 330 */ 331 } 332 pktq = ip_pktq; 333 break; 334 #endif 335 #ifdef INET6 336 case AF_INET6: 337 csum_flags = m->m_pkthdr.csum_flags; 338 KASSERT((csum_flags & ~M_CSUM_UDPv6) == 0); 339 if (csum_flags != 0 && 340 IN6_LOOPBACK_NEED_CHECKSUM(csum_flags)) { 341 in6_undefer_cksum(m, 0, csum_flags); 342 m->m_pkthdr.csum_flags = 0; 343 } else { 344 /* 345 * Do nothing. Pass M_CSUM_UDPv6 as 346 * they are to tell those are calculated and good. 347 */ 348 } 349 m->m_flags |= M_LOOP; 350 pktq = ip6_pktq; 351 break; 352 #endif 353 #ifdef NETATALK 354 case AF_APPLETALK: 355 ifq = &atintrq2; 356 isr = NETISR_ATALK; 357 break; 358 #endif 359 default: 360 printf("%s: can't handle af%d\n", ifp->if_xname, 361 dst->sa_family); 362 m_freem(m); 363 error = EAFNOSUPPORT; 364 goto out; 365 } 366 367 s = splnet(); 368 if (__predict_true(pktq)) { 369 error = 0; 370 371 if (__predict_true(pktq_enqueue(pktq, m, 0))) { 372 if_statadd2(ifp, if_ipackets, 1, 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 if_statadd2(ifp, if_ipackets, 1, if_ibytes, m->m_pkthdr.len); 388 IF_ENQUEUE(ifq, m); 389 schednetisr(isr); 390 splx(s); 391 out: 392 KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 393 return error; 394 } 395 396 #ifdef ALTQ 397 static void 398 lostart(struct ifnet *ifp) 399 { 400 for (;;) { 401 pktqueue_t *pktq = NULL; 402 struct ifqueue *ifq = NULL; 403 struct mbuf *m; 404 size_t pktlen; 405 uint32_t af; 406 int s, isr = 0; 407 408 IFQ_DEQUEUE(&ifp->if_snd, m); 409 if (m == NULL) 410 return; 411 412 af = *(mtod(m, uint32_t *)); 413 m_adj(m, sizeof(uint32_t)); 414 415 switch (af) { 416 #ifdef INET 417 case AF_INET: 418 pktq = ip_pktq; 419 break; 420 #endif 421 #ifdef INET6 422 case AF_INET6: 423 m->m_flags |= M_LOOP; 424 pktq = ip6_pktq; 425 break; 426 #endif 427 #ifdef NETATALK 428 case AF_APPLETALK: 429 ifq = &atintrq2; 430 isr = NETISR_ATALK; 431 break; 432 #endif 433 default: 434 printf("%s: can't handle af%d\n", ifp->if_xname, af); 435 m_freem(m); 436 return; 437 } 438 pktlen = m->m_pkthdr.len; 439 440 s = splnet(); 441 if (__predict_true(pktq)) { 442 if (__predict_false(pktq_enqueue(pktq, m, 0))) { 443 m_freem(m); 444 splx(s); 445 return; 446 } 447 if_statadd2(ifp, if_ipackets, 1, if_ibytes, pktlen); 448 splx(s); 449 continue; 450 } 451 if (IF_QFULL(ifq)) { 452 IF_DROP(ifq); 453 splx(s); 454 m_freem(m); 455 return; 456 } 457 IF_ENQUEUE(ifq, m); 458 schednetisr(isr); 459 if_statadd2(ifp, if_ipackets, 1, if_ibytes, pktlen); 460 splx(s); 461 } 462 } 463 #endif /* ALTQ */ 464 465 /* ARGSUSED */ 466 static void 467 loop_rtrequest(int cmd, struct rtentry *rt, 468 const struct rt_addrinfo *info) 469 { 470 471 if (rt) 472 rt->rt_rmx.rmx_mtu = lo0ifp->if_mtu; 473 } 474 475 /* 476 * Process an ioctl request. 477 */ 478 /* ARGSUSED */ 479 int 480 loioctl(struct ifnet *ifp, u_long cmd, void *data) 481 { 482 struct ifaddr *ifa; 483 struct ifreq *ifr = data; 484 int error = 0; 485 486 switch (cmd) { 487 488 case SIOCINITIFADDR: 489 ifp->if_flags |= IFF_UP; 490 ifa = (struct ifaddr *)data; 491 if (ifa != NULL) 492 ifa->ifa_rtrequest = loop_rtrequest; 493 /* 494 * Everything else is done at a higher level. 495 */ 496 break; 497 498 case SIOCSIFMTU: 499 if ((unsigned)ifr->ifr_mtu > LOMTU_MAX) 500 error = EINVAL; 501 else if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET){ 502 error = 0; 503 } 504 break; 505 506 case SIOCADDMULTI: 507 case SIOCDELMULTI: 508 if (ifr == NULL) { 509 error = EAFNOSUPPORT; /* XXX */ 510 break; 511 } 512 switch (ifreq_getaddr(cmd, ifr)->sa_family) { 513 514 #ifdef INET 515 case AF_INET: 516 break; 517 #endif 518 #ifdef INET6 519 case AF_INET6: 520 break; 521 #endif 522 523 default: 524 error = EAFNOSUPPORT; 525 break; 526 } 527 break; 528 529 default: 530 error = ifioctl_common(ifp, cmd, data); 531 } 532 return (error); 533 } 534 535 /* 536 * Module infrastructure 537 */ 538 #include "if_module.h" 539 540 IF_MODULE(MODULE_CLASS_DRIVER, loop, NULL) 541
Indexes created Wed Sep 24 05:09:52 GMT 2025