if_loop.c revision 1.90
1 /* $NetBSD: if_loop.c,v 1.90 2016/08/07 17:38:34 christos 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 1.90 2016/08/07 17:38:34 christos 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 struct if_clone loop_cloner = 141 IF_CLONE_INITIALIZER("lo", loop_clone_create, loop_clone_destroy); 142 143 void 144 loopattach(int n) 145 { 146 147 /* 148 * Nothing to do here, initialization is handled by the 149 * module initialization code in loopnit() below). 150 */ 151 } 152 153 static void 154 loopinit(void) 155 { 156 157 (void)loop_clone_create(&loop_cloner, 0); /* lo0 always exists */ 158 if_clone_attach(&loop_cloner); 159 } 160 161 static int 162 loopdetach(void) 163 { 164 /* no detach for now; we don't allow lo0 to be deleted */ 165 return EBUSY; 166 } 167 168 static int 169 loop_clone_create(struct if_clone *ifc, int unit) 170 { 171 struct ifnet *ifp; 172 173 ifp = if_alloc(IFT_LOOP); 174 175 if_initname(ifp, ifc->ifc_name, unit); 176 177 ifp->if_mtu = LOMTU; 178 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST | IFF_RUNNING; 179 ifp->if_extflags = IFEF_OUTPUT_MPSAFE; 180 ifp->if_ioctl = loioctl; 181 ifp->if_output = looutput; 182 #ifdef ALTQ 183 ifp->if_start = lostart; 184 #endif 185 ifp->if_type = IFT_LOOP; 186 ifp->if_hdrlen = 0; 187 ifp->if_addrlen = 0; 188 ifp->if_dlt = DLT_NULL; 189 IFQ_SET_READY(&ifp->if_snd); 190 if (unit == 0) 191 lo0ifp = ifp; 192 if_attach(ifp); 193 if_alloc_sadl(ifp); 194 bpf_attach(ifp, DLT_NULL, sizeof(u_int)); 195 #ifdef MBUFTRACE 196 ifp->if_mowner = malloc(sizeof(struct mowner), M_DEVBUF, 197 M_WAITOK | M_ZERO); 198 strlcpy(ifp->if_mowner->mo_name, ifp->if_xname, 199 sizeof(ifp->if_mowner->mo_name)); 200 MOWNER_ATTACH(ifp->if_mowner); 201 #endif 202 203 return (0); 204 } 205 206 static int 207 loop_clone_destroy(struct ifnet *ifp) 208 { 209 210 if (ifp == lo0ifp) 211 return (EPERM); 212 213 #ifdef MBUFTRACE 214 MOWNER_DETACH(ifp->if_mowner); 215 free(ifp->if_mowner, M_DEVBUF); 216 #endif 217 218 bpf_detach(ifp); 219 if_detach(ifp); 220 221 if_free(ifp); 222 223 return (0); 224 } 225 226 int 227 looutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 228 const struct rtentry *rt) 229 { 230 pktqueue_t *pktq = NULL; 231 struct ifqueue *ifq = NULL; 232 int s, isr = -1; 233 int csum_flags; 234 int error = 0; 235 size_t pktlen; 236 237 MCLAIM(m, ifp->if_mowner); 238 239 KERNEL_LOCK(1, NULL); 240 241 if ((m->m_flags & M_PKTHDR) == 0) 242 panic("looutput: no header mbuf"); 243 if (ifp->if_flags & IFF_LOOPBACK) 244 bpf_mtap_af(ifp, dst->sa_family, m); 245 m_set_rcvif(m, ifp); 246 247 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 248 m_freem(m); 249 error = (rt->rt_flags & RTF_BLACKHOLE ? 0 : 250 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 251 goto out; 252 } 253 254 pktlen = m->m_pkthdr.len; 255 ifp->if_opackets++; 256 ifp->if_obytes += pktlen; 257 258 #ifdef ALTQ 259 /* 260 * ALTQ on the loopback interface is just for debugging. It's 261 * used only for loopback interfaces, not for a simplex interface. 262 */ 263 if ((ALTQ_IS_ENABLED(&ifp->if_snd) || TBR_IS_ENABLED(&ifp->if_snd)) && 264 ifp->if_start == lostart) { 265 /* 266 * If the queueing discipline needs packet classification, 267 * do it before prepending the link headers. 268 */ 269 IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family); 270 271 M_PREPEND(m, sizeof(uint32_t), M_DONTWAIT); 272 if (m == NULL) { 273 error = ENOBUFS; 274 goto out; 275 } 276 *(mtod(m, uint32_t *)) = dst->sa_family; 277 278 error = if_transmit_lock(ifp, m); 279 goto out; 280 } 281 #endif /* ALTQ */ 282 283 m_tag_delete_nonpersistent(m); 284 285 #ifdef MPLS 286 if (rt != NULL && rt_gettag(rt) != NULL && 287 rt_gettag(rt)->sa_family == AF_MPLS && 288 (m->m_flags & (M_MCAST | M_BCAST)) == 0) { 289 union mpls_shim msh; 290 msh.s_addr = MPLS_GETSADDR(rt); 291 if (msh.shim.label != MPLS_LABEL_IMPLNULL) { 292 ifq = &mplsintrq; 293 isr = NETISR_MPLS; 294 } 295 } 296 if (isr != NETISR_MPLS) 297 #endif 298 switch (dst->sa_family) { 299 300 #ifdef INET 301 case AF_INET: 302 csum_flags = m->m_pkthdr.csum_flags; 303 KASSERT((csum_flags & ~(M_CSUM_IPv4|M_CSUM_UDPv4)) == 0); 304 if (csum_flags != 0 && IN_LOOPBACK_NEED_CHECKSUM(csum_flags)) { 305 ip_undefer_csum(m, 0, csum_flags); 306 } 307 m->m_pkthdr.csum_flags = 0; 308 pktq = ip_pktq; 309 break; 310 #endif 311 #ifdef INET6 312 case AF_INET6: 313 csum_flags = m->m_pkthdr.csum_flags; 314 KASSERT((csum_flags & ~M_CSUM_UDPv6) == 0); 315 if (csum_flags != 0 && 316 IN6_LOOPBACK_NEED_CHECKSUM(csum_flags)) { 317 ip6_undefer_csum(m, 0, csum_flags); 318 } 319 m->m_pkthdr.csum_flags = 0; 320 m->m_flags |= M_LOOP; 321 pktq = ip6_pktq; 322 break; 323 #endif 324 #ifdef NETATALK 325 case AF_APPLETALK: 326 ifq = &atintrq2; 327 isr = NETISR_ATALK; 328 break; 329 #endif 330 default: 331 printf("%s: can't handle af%d\n", ifp->if_xname, 332 dst->sa_family); 333 m_freem(m); 334 error = EAFNOSUPPORT; 335 goto out; 336 } 337 338 s = splnet(); 339 if (__predict_true(pktq)) { 340 error = 0; 341 342 if (__predict_true(pktq_enqueue(pktq, m, 0))) { 343 ifp->if_ipackets++; 344 ifp->if_ibytes += pktlen; 345 } else { 346 m_freem(m); 347 error = ENOBUFS; 348 } 349 splx(s); 350 goto out; 351 } 352 if (IF_QFULL(ifq)) { 353 IF_DROP(ifq); 354 m_freem(m); 355 splx(s); 356 error = ENOBUFS; 357 goto out; 358 } 359 IF_ENQUEUE(ifq, m); 360 schednetisr(isr); 361 ifp->if_ipackets++; 362 ifp->if_ibytes += m->m_pkthdr.len; 363 splx(s); 364 out: 365 KERNEL_UNLOCK_ONE(NULL); 366 return error; 367 } 368 369 #ifdef ALTQ 370 static void 371 lostart(struct ifnet *ifp) 372 { 373 for (;;) { 374 pktqueue_t *pktq = NULL; 375 struct ifqueue *ifq = NULL; 376 struct mbuf *m; 377 size_t pktlen; 378 uint32_t af; 379 int s, isr = 0; 380 381 IFQ_DEQUEUE(&ifp->if_snd, m); 382 if (m == NULL) 383 return; 384 385 af = *(mtod(m, uint32_t *)); 386 m_adj(m, sizeof(uint32_t)); 387 388 switch (af) { 389 #ifdef INET 390 case AF_INET: 391 pktq = ip_pktq; 392 break; 393 #endif 394 #ifdef INET6 395 case AF_INET6: 396 m->m_flags |= M_LOOP; 397 pktq = ip6_pktq; 398 break; 399 #endif 400 #ifdef NETATALK 401 case AF_APPLETALK: 402 ifq = &atintrq2; 403 isr = NETISR_ATALK; 404 break; 405 #endif 406 default: 407 printf("%s: can't handle af%d\n", ifp->if_xname, af); 408 m_freem(m); 409 return; 410 } 411 pktlen = m->m_pkthdr.len; 412 413 s = splnet(); 414 if (__predict_true(pktq)) { 415 if (__predict_false(pktq_enqueue(pktq, m, 0))) { 416 m_freem(m); 417 splx(s); 418 return; 419 } 420 ifp->if_ipackets++; 421 ifp->if_ibytes += pktlen; 422 splx(s); 423 continue; 424 } 425 if (IF_QFULL(ifq)) { 426 IF_DROP(ifq); 427 splx(s); 428 m_freem(m); 429 return; 430 } 431 IF_ENQUEUE(ifq, m); 432 schednetisr(isr); 433 ifp->if_ipackets++; 434 ifp->if_ibytes += pktlen; 435 splx(s); 436 } 437 } 438 #endif /* ALTQ */ 439 440 /* ARGSUSED */ 441 void 442 lortrequest(int cmd, struct rtentry *rt, 443 const struct rt_addrinfo *info) 444 { 445 446 if (rt) 447 rt->rt_rmx.rmx_mtu = lo0ifp->if_mtu; 448 } 449 450 /* 451 * Process an ioctl request. 452 */ 453 /* ARGSUSED */ 454 int 455 loioctl(struct ifnet *ifp, u_long cmd, void *data) 456 { 457 struct ifaddr *ifa; 458 struct ifreq *ifr = data; 459 int error = 0; 460 461 switch (cmd) { 462 463 case SIOCINITIFADDR: 464 ifp->if_flags |= IFF_UP; 465 ifa = (struct ifaddr *)data; 466 if (ifa != NULL) 467 ifa->ifa_rtrequest = lortrequest; 468 /* 469 * Everything else is done at a higher level. 470 */ 471 break; 472 473 case SIOCSIFMTU: 474 if ((unsigned)ifr->ifr_mtu > LOMTU_MAX) 475 error = EINVAL; 476 else if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET){ 477 error = 0; 478 } 479 break; 480 481 case SIOCADDMULTI: 482 case SIOCDELMULTI: 483 if (ifr == NULL) { 484 error = EAFNOSUPPORT; /* XXX */ 485 break; 486 } 487 switch (ifreq_getaddr(cmd, ifr)->sa_family) { 488 489 #ifdef INET 490 case AF_INET: 491 break; 492 #endif 493 #ifdef INET6 494 case AF_INET6: 495 break; 496 #endif 497 498 default: 499 error = EAFNOSUPPORT; 500 break; 501 } 502 break; 503 504 default: 505 error = ifioctl_common(ifp, cmd, data); 506 } 507 return (error); 508 } 509 510 /* 511 * Module infrastructure 512 */ 513 #include "if_module.h" 514 515 IF_MODULE(MODULE_CLASS_DRIVER, loop, "") 516
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