if_loop.c revision 1.94
1 /* $NetBSD: if_loop.c,v 1.94 2017/03/28 08:47:19 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 1.94 2017/03/28 08:47:19 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 /* 150 * Nothing to do here, initialization is handled by the 151 * module initialization code in loopnit() below). 152 */ 153 } 154 155 void 156 loopinit(void) 157 { 158 159 if (lo0ifp != NULL) /* can happen in rump kernel */ 160 return; 161 162 (void)loop_clone_create(&loop_cloner, 0); /* lo0 always exists */ 163 if_clone_attach(&loop_cloner); 164 } 165 166 static int 167 loopdetach(void) 168 { 169 /* no detach for now; we don't allow lo0 to be deleted */ 170 return EBUSY; 171 } 172 173 static int 174 loop_clone_create(struct if_clone *ifc, int unit) 175 { 176 struct ifnet *ifp; 177 178 ifp = if_alloc(IFT_LOOP); 179 180 if_initname(ifp, ifc->ifc_name, unit); 181 182 ifp->if_mtu = LOMTU; 183 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST | IFF_RUNNING; 184 ifp->if_extflags = IFEF_OUTPUT_MPSAFE; 185 ifp->if_ioctl = loioctl; 186 ifp->if_output = looutput; 187 #ifdef ALTQ 188 ifp->if_start = lostart; 189 #endif 190 ifp->if_type = IFT_LOOP; 191 ifp->if_hdrlen = 0; 192 ifp->if_addrlen = 0; 193 ifp->if_dlt = DLT_NULL; 194 IFQ_SET_READY(&ifp->if_snd); 195 if (unit == 0) 196 lo0ifp = ifp; 197 if_attach(ifp); 198 if_alloc_sadl(ifp); 199 bpf_attach(ifp, DLT_NULL, sizeof(u_int)); 200 #ifdef MBUFTRACE 201 ifp->if_mowner = malloc(sizeof(struct mowner), M_DEVBUF, 202 M_WAITOK | M_ZERO); 203 strlcpy(ifp->if_mowner->mo_name, ifp->if_xname, 204 sizeof(ifp->if_mowner->mo_name)); 205 MOWNER_ATTACH(ifp->if_mowner); 206 #endif 207 208 return (0); 209 } 210 211 static int 212 loop_clone_destroy(struct ifnet *ifp) 213 { 214 215 if (ifp == lo0ifp) 216 return (EPERM); 217 218 #ifdef MBUFTRACE 219 MOWNER_DETACH(ifp->if_mowner); 220 free(ifp->if_mowner, M_DEVBUF); 221 #endif 222 223 bpf_detach(ifp); 224 if_detach(ifp); 225 226 if_free(ifp); 227 228 return (0); 229 } 230 231 int 232 looutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 233 const struct rtentry *rt) 234 { 235 pktqueue_t *pktq = NULL; 236 struct ifqueue *ifq = NULL; 237 int s, isr = -1; 238 int csum_flags; 239 int error = 0; 240 size_t pktlen; 241 242 MCLAIM(m, ifp->if_mowner); 243 244 KERNEL_LOCK(1, NULL); 245 246 if ((m->m_flags & M_PKTHDR) == 0) 247 panic("looutput: no header mbuf"); 248 if (ifp->if_flags & IFF_LOOPBACK) 249 bpf_mtap_af(ifp, dst->sa_family, m); 250 m_set_rcvif(m, ifp); 251 252 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 253 m_freem(m); 254 error = (rt->rt_flags & RTF_BLACKHOLE ? 0 : 255 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 256 goto out; 257 } 258 259 pktlen = m->m_pkthdr.len; 260 ifp->if_opackets++; 261 ifp->if_obytes += pktlen; 262 263 #ifdef ALTQ 264 /* 265 * ALTQ on the loopback interface is just for debugging. It's 266 * used only for loopback interfaces, not for a simplex interface. 267 */ 268 if ((ALTQ_IS_ENABLED(&ifp->if_snd) || TBR_IS_ENABLED(&ifp->if_snd)) && 269 ifp->if_start == lostart) { 270 /* 271 * If the queueing discipline needs packet classification, 272 * do it before prepending the link headers. 273 */ 274 IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family); 275 276 M_PREPEND(m, sizeof(uint32_t), M_DONTWAIT); 277 if (m == NULL) { 278 error = ENOBUFS; 279 goto out; 280 } 281 *(mtod(m, uint32_t *)) = dst->sa_family; 282 283 error = if_transmit_lock(ifp, m); 284 goto out; 285 } 286 #endif /* ALTQ */ 287 288 m_tag_delete_nonpersistent(m); 289 290 #ifdef MPLS 291 if (rt != NULL && rt_gettag(rt) != NULL && 292 rt_gettag(rt)->sa_family == AF_MPLS && 293 (m->m_flags & (M_MCAST | M_BCAST)) == 0) { 294 union mpls_shim msh; 295 msh.s_addr = MPLS_GETSADDR(rt); 296 if (msh.shim.label != MPLS_LABEL_IMPLNULL) { 297 ifq = &mplsintrq; 298 isr = NETISR_MPLS; 299 } 300 } 301 if (isr != NETISR_MPLS) 302 #endif 303 switch (dst->sa_family) { 304 305 #ifdef INET 306 case AF_INET: 307 csum_flags = m->m_pkthdr.csum_flags; 308 KASSERT((csum_flags & ~(M_CSUM_IPv4|M_CSUM_UDPv4)) == 0); 309 if (csum_flags != 0 && IN_LOOPBACK_NEED_CHECKSUM(csum_flags)) { 310 ip_undefer_csum(m, 0, csum_flags); 311 } 312 m->m_pkthdr.csum_flags = 0; 313 pktq = ip_pktq; 314 break; 315 #endif 316 #ifdef INET6 317 case AF_INET6: 318 csum_flags = m->m_pkthdr.csum_flags; 319 KASSERT((csum_flags & ~M_CSUM_UDPv6) == 0); 320 if (csum_flags != 0 && 321 IN6_LOOPBACK_NEED_CHECKSUM(csum_flags)) { 322 ip6_undefer_csum(m, 0, csum_flags); 323 } 324 m->m_pkthdr.csum_flags = 0; 325 m->m_flags |= M_LOOP; 326 pktq = ip6_pktq; 327 break; 328 #endif 329 #ifdef NETATALK 330 case AF_APPLETALK: 331 ifq = &atintrq2; 332 isr = NETISR_ATALK; 333 break; 334 #endif 335 default: 336 printf("%s: can't handle af%d\n", ifp->if_xname, 337 dst->sa_family); 338 m_freem(m); 339 error = EAFNOSUPPORT; 340 goto out; 341 } 342 343 s = splnet(); 344 if (__predict_true(pktq)) { 345 error = 0; 346 347 if (__predict_true(pktq_enqueue(pktq, m, 0))) { 348 ifp->if_ipackets++; 349 ifp->if_ibytes += pktlen; 350 } else { 351 m_freem(m); 352 error = ENOBUFS; 353 } 354 splx(s); 355 goto out; 356 } 357 if (IF_QFULL(ifq)) { 358 IF_DROP(ifq); 359 m_freem(m); 360 splx(s); 361 error = ENOBUFS; 362 goto out; 363 } 364 ifp->if_ipackets++; 365 ifp->if_ibytes += m->m_pkthdr.len; 366 IF_ENQUEUE(ifq, m); 367 schednetisr(isr); 368 splx(s); 369 out: 370 KERNEL_UNLOCK_ONE(NULL); 371 return error; 372 } 373 374 #ifdef ALTQ 375 static void 376 lostart(struct ifnet *ifp) 377 { 378 for (;;) { 379 pktqueue_t *pktq = NULL; 380 struct ifqueue *ifq = NULL; 381 struct mbuf *m; 382 size_t pktlen; 383 uint32_t af; 384 int s, isr = 0; 385 386 IFQ_DEQUEUE(&ifp->if_snd, m); 387 if (m == NULL) 388 return; 389 390 af = *(mtod(m, uint32_t *)); 391 m_adj(m, sizeof(uint32_t)); 392 393 switch (af) { 394 #ifdef INET 395 case AF_INET: 396 pktq = ip_pktq; 397 break; 398 #endif 399 #ifdef INET6 400 case AF_INET6: 401 m->m_flags |= M_LOOP; 402 pktq = ip6_pktq; 403 break; 404 #endif 405 #ifdef NETATALK 406 case AF_APPLETALK: 407 ifq = &atintrq2; 408 isr = NETISR_ATALK; 409 break; 410 #endif 411 default: 412 printf("%s: can't handle af%d\n", ifp->if_xname, af); 413 m_freem(m); 414 return; 415 } 416 pktlen = m->m_pkthdr.len; 417 418 s = splnet(); 419 if (__predict_true(pktq)) { 420 if (__predict_false(pktq_enqueue(pktq, m, 0))) { 421 m_freem(m); 422 splx(s); 423 return; 424 } 425 ifp->if_ipackets++; 426 ifp->if_ibytes += pktlen; 427 splx(s); 428 continue; 429 } 430 if (IF_QFULL(ifq)) { 431 IF_DROP(ifq); 432 splx(s); 433 m_freem(m); 434 return; 435 } 436 IF_ENQUEUE(ifq, m); 437 schednetisr(isr); 438 ifp->if_ipackets++; 439 ifp->if_ibytes += pktlen; 440 splx(s); 441 } 442 } 443 #endif /* ALTQ */ 444 445 /* ARGSUSED */ 446 static void 447 loop_rtrequest(int cmd, struct rtentry *rt, 448 const struct rt_addrinfo *info) 449 { 450 451 if (rt) 452 rt->rt_rmx.rmx_mtu = lo0ifp->if_mtu; 453 } 454 455 /* 456 * Process an ioctl request. 457 */ 458 /* ARGSUSED */ 459 int 460 loioctl(struct ifnet *ifp, u_long cmd, void *data) 461 { 462 struct ifaddr *ifa; 463 struct ifreq *ifr = data; 464 int error = 0; 465 466 switch (cmd) { 467 468 case SIOCINITIFADDR: 469 ifp->if_flags |= IFF_UP; 470 ifa = (struct ifaddr *)data; 471 if (ifa != NULL) 472 ifa->ifa_rtrequest = loop_rtrequest; 473 /* 474 * Everything else is done at a higher level. 475 */ 476 break; 477 478 case SIOCSIFMTU: 479 if ((unsigned)ifr->ifr_mtu > LOMTU_MAX) 480 error = EINVAL; 481 else if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET){ 482 error = 0; 483 } 484 break; 485 486 case SIOCADDMULTI: 487 case SIOCDELMULTI: 488 if (ifr == NULL) { 489 error = EAFNOSUPPORT; /* XXX */ 490 break; 491 } 492 switch (ifreq_getaddr(cmd, ifr)->sa_family) { 493 494 #ifdef INET 495 case AF_INET: 496 break; 497 #endif 498 #ifdef INET6 499 case AF_INET6: 500 break; 501 #endif 502 503 default: 504 error = EAFNOSUPPORT; 505 break; 506 } 507 break; 508 509 default: 510 error = ifioctl_common(ifp, cmd, data); 511 } 512 return (error); 513 } 514 515 /* 516 * Module infrastructure 517 */ 518 #include "if_module.h" 519 520 IF_MODULE(MODULE_CLASS_DRIVER, loop, "") 521
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