1 /* $NetBSD: ip_output.c,v 1.227 2014/05/23 00:02:14 rmind 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) 1998 The NetBSD Foundation, Inc. 34 * All rights reserved. 35 * 36 * This code is derived from software contributed to The NetBSD Foundation 37 * by Public Access Networks Corporation ("Panix"). It was developed under 38 * contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon. 39 * 40 * Redistribution and use in source and binary forms, with or without 41 * modification, are permitted provided that the following conditions 42 * are met: 43 * 1. Redistributions of source code must retain the above copyright 44 * notice, this list of conditions and the following disclaimer. 45 * 2. Redistributions in binary form must reproduce the above copyright 46 * notice, this list of conditions and the following disclaimer in the 47 * documentation and/or other materials provided with the distribution. 48 * 49 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 50 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 51 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 52 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 53 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 54 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 55 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 56 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 57 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 58 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 59 * POSSIBILITY OF SUCH DAMAGE. 60 */ 61 62 /* 63 * Copyright (c) 1982, 1986, 1988, 1990, 1993 64 * The Regents of the University of California. All rights reserved. 65 * 66 * Redistribution and use in source and binary forms, with or without 67 * modification, are permitted provided that the following conditions 68 * are met: 69 * 1. Redistributions of source code must retain the above copyright 70 * notice, this list of conditions and the following disclaimer. 71 * 2. Redistributions in binary form must reproduce the above copyright 72 * notice, this list of conditions and the following disclaimer in the 73 * documentation and/or other materials provided with the distribution. 74 * 3. Neither the name of the University nor the names of its contributors 75 * may be used to endorse or promote products derived from this software 76 * without specific prior written permission. 77 * 78 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 79 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 80 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 81 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 82 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 83 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 84 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 85 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 86 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 87 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 88 * SUCH DAMAGE. 89 * 90 * @(#)ip_output.c 8.3 (Berkeley) 1/21/94 91 */ 92 93 #include <sys/cdefs.h> 94 __KERNEL_RCSID(0, "$NetBSD: ip_output.c,v 1.227 2014/05/23 00:02:14 rmind Exp $"); 95 96 #include "opt_inet.h" 97 #include "opt_ipsec.h" 98 #include "opt_mrouting.h" 99 100 #include <sys/param.h> 101 #include <sys/kmem.h> 102 #include <sys/mbuf.h> 103 #include <sys/protosw.h> 104 #include <sys/socket.h> 105 #include <sys/socketvar.h> 106 #include <sys/kauth.h> 107 #ifdef IPSEC 108 #include <sys/domain.h> 109 #endif 110 #include <sys/systm.h> 111 112 #include <net/if.h> 113 #include <net/route.h> 114 #include <net/pfil.h> 115 116 #include <netinet/in.h> 117 #include <netinet/in_systm.h> 118 #include <netinet/ip.h> 119 #include <netinet/in_pcb.h> 120 #include <netinet/in_var.h> 121 #include <netinet/ip_var.h> 122 #include <netinet/ip_private.h> 123 #include <netinet/in_offload.h> 124 #include <netinet/portalgo.h> 125 #include <netinet/udp.h> 126 127 #ifdef MROUTING 128 #include <netinet/ip_mroute.h> 129 #endif 130 131 #include <netipsec/ipsec.h> 132 #include <netipsec/key.h> 133 134 static int ip_pcbopts(struct inpcb *, const struct sockopt *); 135 static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *); 136 static struct ifnet *ip_multicast_if(struct in_addr *, int *); 137 static void ip_mloopback(struct ifnet *, struct mbuf *, 138 const struct sockaddr_in *); 139 static int ip_setmoptions(struct inpcb *, const struct sockopt *); 140 static int ip_getmoptions(struct inpcb *, struct sockopt *); 141 142 extern pfil_head_t *inet_pfil_hook; /* XXX */ 143 144 int ip_do_loopback_cksum = 0; 145 146 /* 147 * IP output. The packet in mbuf chain m contains a skeletal IP 148 * header (with len, off, ttl, proto, tos, src, dst). 149 * The mbuf chain containing the packet will be freed. 150 * The mbuf opt, if present, will not be freed. 151 */ 152 int 153 ip_output(struct mbuf *m0, ...) 154 { 155 struct rtentry *rt; 156 struct ip *ip; 157 struct ifnet *ifp; 158 struct mbuf *m = m0; 159 int hlen = sizeof (struct ip); 160 int len, error = 0; 161 struct route iproute; 162 const struct sockaddr_in *dst; 163 struct in_ifaddr *ia; 164 struct ifaddr *xifa; 165 struct mbuf *opt; 166 struct route *ro; 167 int flags, sw_csum; 168 u_long mtu; 169 struct ip_moptions *imo; 170 struct socket *so; 171 va_list ap; 172 struct secpolicy *sp = NULL; 173 bool natt_frag = false; 174 bool __unused done = false; 175 union { 176 struct sockaddr dst; 177 struct sockaddr_in dst4; 178 } u; 179 struct sockaddr *rdst = &u.dst; /* real IP destination, as opposed 180 * to the nexthop 181 */ 182 183 len = 0; 184 va_start(ap, m0); 185 opt = va_arg(ap, struct mbuf *); 186 ro = va_arg(ap, struct route *); 187 flags = va_arg(ap, int); 188 imo = va_arg(ap, struct ip_moptions *); 189 so = va_arg(ap, struct socket *); 190 va_end(ap); 191 192 MCLAIM(m, &ip_tx_mowner); 193 194 KASSERT((m->m_flags & M_PKTHDR) != 0); 195 KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_TCPv6|M_CSUM_UDPv6)) == 0); 196 KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) != 197 (M_CSUM_TCPv4|M_CSUM_UDPv4)); 198 199 if (opt) { 200 m = ip_insertoptions(m, opt, &len); 201 if (len >= sizeof(struct ip)) 202 hlen = len; 203 } 204 ip = mtod(m, struct ip *); 205 206 /* 207 * Fill in IP header. 208 */ 209 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 210 ip->ip_v = IPVERSION; 211 ip->ip_off = htons(0); 212 /* ip->ip_id filled in after we find out source ia */ 213 ip->ip_hl = hlen >> 2; 214 IP_STATINC(IP_STAT_LOCALOUT); 215 } else { 216 hlen = ip->ip_hl << 2; 217 } 218 219 /* 220 * Route packet. 221 */ 222 memset(&iproute, 0, sizeof(iproute)); 223 if (ro == NULL) 224 ro = &iproute; 225 sockaddr_in_init(&u.dst4, &ip->ip_dst, 0); 226 dst = satocsin(rtcache_getdst(ro)); 227 228 /* 229 * If there is a cached route, check that it is to the same 230 * destination and is still up. If not, free it and try again. 231 * The address family should also be checked in case of sharing 232 * the cache with IPv6. 233 */ 234 if (dst && (dst->sin_family != AF_INET || 235 !in_hosteq(dst->sin_addr, ip->ip_dst))) 236 rtcache_free(ro); 237 238 if ((rt = rtcache_validate(ro)) == NULL && 239 (rt = rtcache_update(ro, 1)) == NULL) { 240 dst = &u.dst4; 241 rtcache_setdst(ro, &u.dst); 242 } 243 244 /* 245 * If routing to interface only, short circuit routing lookup. 246 */ 247 if (flags & IP_ROUTETOIF) { 248 if ((ia = ifatoia(ifa_ifwithladdr(sintocsa(dst)))) == NULL) { 249 IP_STATINC(IP_STAT_NOROUTE); 250 error = ENETUNREACH; 251 goto bad; 252 } 253 ifp = ia->ia_ifp; 254 mtu = ifp->if_mtu; 255 ip->ip_ttl = 1; 256 } else if ((IN_MULTICAST(ip->ip_dst.s_addr) || 257 ip->ip_dst.s_addr == INADDR_BROADCAST) && 258 imo != NULL && imo->imo_multicast_ifp != NULL) { 259 ifp = imo->imo_multicast_ifp; 260 mtu = ifp->if_mtu; 261 IFP_TO_IA(ifp, ia); 262 } else { 263 if (rt == NULL) 264 rt = rtcache_init(ro); 265 if (rt == NULL) { 266 IP_STATINC(IP_STAT_NOROUTE); 267 error = EHOSTUNREACH; 268 goto bad; 269 } 270 ia = ifatoia(rt->rt_ifa); 271 ifp = rt->rt_ifp; 272 if ((mtu = rt->rt_rmx.rmx_mtu) == 0) 273 mtu = ifp->if_mtu; 274 rt->rt_use++; 275 if (rt->rt_flags & RTF_GATEWAY) 276 dst = satosin(rt->rt_gateway); 277 } 278 279 if (IN_MULTICAST(ip->ip_dst.s_addr) || 280 (ip->ip_dst.s_addr == INADDR_BROADCAST)) { 281 struct in_multi *inm; 282 283 m->m_flags |= (ip->ip_dst.s_addr == INADDR_BROADCAST) ? 284 M_BCAST : M_MCAST; 285 /* 286 * See if the caller provided any multicast options 287 */ 288 if (imo != NULL) 289 ip->ip_ttl = imo->imo_multicast_ttl; 290 else 291 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 292 293 /* 294 * if we don't know the outgoing ifp yet, we can't generate 295 * output 296 */ 297 if (!ifp) { 298 IP_STATINC(IP_STAT_NOROUTE); 299 error = ENETUNREACH; 300 goto bad; 301 } 302 303 /* 304 * If the packet is multicast or broadcast, confirm that 305 * the outgoing interface can transmit it. 306 */ 307 if (((m->m_flags & M_MCAST) && 308 (ifp->if_flags & IFF_MULTICAST) == 0) || 309 ((m->m_flags & M_BCAST) && 310 (ifp->if_flags & (IFF_BROADCAST|IFF_POINTOPOINT)) == 0)) { 311 IP_STATINC(IP_STAT_NOROUTE); 312 error = ENETUNREACH; 313 goto bad; 314 } 315 /* 316 * If source address not specified yet, use an address 317 * of outgoing interface. 318 */ 319 if (in_nullhost(ip->ip_src)) { 320 struct in_ifaddr *xia; 321 322 IFP_TO_IA(ifp, xia); 323 if (!xia) { 324 error = EADDRNOTAVAIL; 325 goto bad; 326 } 327 xifa = &xia->ia_ifa; 328 if (xifa->ifa_getifa != NULL) { 329 xia = ifatoia((*xifa->ifa_getifa)(xifa, rdst)); 330 } 331 ip->ip_src = xia->ia_addr.sin_addr; 332 } 333 334 IN_LOOKUP_MULTI(ip->ip_dst, ifp, inm); 335 if (inm != NULL && 336 (imo == NULL || imo->imo_multicast_loop)) { 337 /* 338 * If we belong to the destination multicast group 339 * on the outgoing interface, and the caller did not 340 * forbid loopback, loop back a copy. 341 */ 342 ip_mloopback(ifp, m, &u.dst4); 343 } 344 #ifdef MROUTING 345 else { 346 /* 347 * If we are acting as a multicast router, perform 348 * multicast forwarding as if the packet had just 349 * arrived on the interface to which we are about 350 * to send. The multicast forwarding function 351 * recursively calls this function, using the 352 * IP_FORWARDING flag to prevent infinite recursion. 353 * 354 * Multicasts that are looped back by ip_mloopback(), 355 * above, will be forwarded by the ip_input() routine, 356 * if necessary. 357 */ 358 extern struct socket *ip_mrouter; 359 360 if (ip_mrouter && (flags & IP_FORWARDING) == 0) { 361 if (ip_mforward(m, ifp) != 0) { 362 m_freem(m); 363 goto done; 364 } 365 } 366 } 367 #endif 368 /* 369 * Multicasts with a time-to-live of zero may be looped- 370 * back, above, but must not be transmitted on a network. 371 * Also, multicasts addressed to the loopback interface 372 * are not sent -- the above call to ip_mloopback() will 373 * loop back a copy if this host actually belongs to the 374 * destination group on the loopback interface. 375 */ 376 if (ip->ip_ttl == 0 || (ifp->if_flags & IFF_LOOPBACK) != 0) { 377 m_freem(m); 378 goto done; 379 } 380 381 goto sendit; 382 } 383 /* 384 * If source address not specified yet, use address 385 * of outgoing interface. 386 */ 387 if (in_nullhost(ip->ip_src)) { 388 xifa = &ia->ia_ifa; 389 if (xifa->ifa_getifa != NULL) 390 ia = ifatoia((*xifa->ifa_getifa)(xifa, rdst)); 391 ip->ip_src = ia->ia_addr.sin_addr; 392 } 393 394 /* 395 * packets with Class-D address as source are not valid per 396 * RFC 1112 397 */ 398 if (IN_MULTICAST(ip->ip_src.s_addr)) { 399 IP_STATINC(IP_STAT_ODROPPED); 400 error = EADDRNOTAVAIL; 401 goto bad; 402 } 403 404 /* 405 * Look for broadcast address and 406 * and verify user is allowed to send 407 * such a packet. 408 */ 409 if (in_broadcast(dst->sin_addr, ifp)) { 410 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 411 error = EADDRNOTAVAIL; 412 goto bad; 413 } 414 if ((flags & IP_ALLOWBROADCAST) == 0) { 415 error = EACCES; 416 goto bad; 417 } 418 /* don't allow broadcast messages to be fragmented */ 419 if (ntohs(ip->ip_len) > ifp->if_mtu) { 420 error = EMSGSIZE; 421 goto bad; 422 } 423 m->m_flags |= M_BCAST; 424 } else 425 m->m_flags &= ~M_BCAST; 426 427 sendit: 428 if ((flags & (IP_FORWARDING|IP_NOIPNEWID)) == 0) { 429 if (m->m_pkthdr.len < IP_MINFRAGSIZE) { 430 ip->ip_id = 0; 431 } else if ((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) { 432 ip->ip_id = ip_newid(ia); 433 } else { 434 435 /* 436 * TSO capable interfaces (typically?) increment 437 * ip_id for each segment. 438 * "allocate" enough ids here to increase the chance 439 * for them to be unique. 440 * 441 * note that the following calculation is not 442 * needed to be precise. wasting some ip_id is fine. 443 */ 444 445 unsigned int segsz = m->m_pkthdr.segsz; 446 unsigned int datasz = ntohs(ip->ip_len) - hlen; 447 unsigned int num = howmany(datasz, segsz); 448 449 ip->ip_id = ip_newid_range(ia, num); 450 } 451 } 452 /* 453 * If we're doing Path MTU Discovery, we need to set DF unless 454 * the route's MTU is locked. 455 */ 456 if ((flags & IP_MTUDISC) != 0 && rt != NULL && 457 (rt->rt_rmx.rmx_locks & RTV_MTU) == 0) 458 ip->ip_off |= htons(IP_DF); 459 460 #ifdef IPSEC 461 /* Perform IPsec processing, if any. */ 462 error = ipsec4_output(m, so, flags, &sp, &mtu, &natt_frag, &done); 463 if (error || done) { 464 goto done; 465 } 466 #endif 467 468 /* 469 * Run through list of hooks for output packets. 470 */ 471 if ((error = pfil_run_hooks(inet_pfil_hook, &m, ifp, PFIL_OUT)) != 0) 472 goto done; 473 if (m == NULL) 474 goto done; 475 476 ip = mtod(m, struct ip *); 477 hlen = ip->ip_hl << 2; 478 479 m->m_pkthdr.csum_data |= hlen << 16; 480 481 #if IFA_STATS 482 /* 483 * search for the source address structure to 484 * maintain output statistics. 485 */ 486 INADDR_TO_IA(ip->ip_src, ia); 487 #endif 488 489 /* Maybe skip checksums on loopback interfaces. */ 490 if (IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) { 491 m->m_pkthdr.csum_flags |= M_CSUM_IPv4; 492 } 493 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_csum_flags_tx; 494 /* 495 * If small enough for mtu of path, or if using TCP segmentation 496 * offload, can just send directly. 497 */ 498 if (ntohs(ip->ip_len) <= mtu || 499 (m->m_pkthdr.csum_flags & M_CSUM_TSOv4) != 0) { 500 #if IFA_STATS 501 if (ia) 502 ia->ia_ifa.ifa_data.ifad_outbytes += ntohs(ip->ip_len); 503 #endif 504 /* 505 * Always initialize the sum to 0! Some HW assisted 506 * checksumming requires this. 507 */ 508 ip->ip_sum = 0; 509 510 if ((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) { 511 /* 512 * Perform any checksums that the hardware can't do 513 * for us. 514 * 515 * XXX Does any hardware require the {th,uh}_sum 516 * XXX fields to be 0? 517 */ 518 if (sw_csum & M_CSUM_IPv4) { 519 KASSERT(IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)); 520 ip->ip_sum = in_cksum(m, hlen); 521 m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4; 522 } 523 if (sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 524 if (IN_NEED_CHECKSUM(ifp, 525 sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4))) { 526 in_delayed_cksum(m); 527 } 528 m->m_pkthdr.csum_flags &= 529 ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 530 } 531 } 532 533 if (__predict_true( 534 (m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0 || 535 (ifp->if_capenable & IFCAP_TSOv4) != 0)) { 536 KERNEL_LOCK(1, NULL); 537 error = 538 (*ifp->if_output)(ifp, m, 539 (m->m_flags & M_MCAST) ? 540 sintocsa(rdst) : sintocsa(dst), 541 rt); 542 KERNEL_UNLOCK_ONE(NULL); 543 } else { 544 error = 545 ip_tso_output(ifp, m, 546 (m->m_flags & M_MCAST) ? 547 sintocsa(rdst) : sintocsa(dst), 548 rt); 549 } 550 goto done; 551 } 552 553 /* 554 * We can't use HW checksumming if we're about to 555 * to fragment the packet. 556 * 557 * XXX Some hardware can do this. 558 */ 559 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 560 if (IN_NEED_CHECKSUM(ifp, 561 m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4))) { 562 in_delayed_cksum(m); 563 } 564 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 565 } 566 567 /* 568 * Too large for interface; fragment if possible. 569 * Must be able to put at least 8 bytes per fragment. 570 */ 571 if (ntohs(ip->ip_off) & IP_DF) { 572 if (flags & IP_RETURNMTU) { 573 struct inpcb *inp; 574 575 KASSERT(so && solocked(so)); 576 inp = sotoinpcb(so); 577 inp->inp_errormtu = mtu; 578 } 579 error = EMSGSIZE; 580 IP_STATINC(IP_STAT_CANTFRAG); 581 goto bad; 582 } 583 584 error = ip_fragment(m, ifp, mtu); 585 if (error) { 586 m = NULL; 587 goto bad; 588 } 589 590 for (; m; m = m0) { 591 m0 = m->m_nextpkt; 592 m->m_nextpkt = 0; 593 if (error == 0) { 594 #if IFA_STATS 595 if (ia) 596 ia->ia_ifa.ifa_data.ifad_outbytes += 597 ntohs(ip->ip_len); 598 #endif 599 /* 600 * If we get there, the packet has not been handled by 601 * IPsec whereas it should have. Now that it has been 602 * fragmented, re-inject it in ip_output so that IPsec 603 * processing can occur. 604 */ 605 if (natt_frag) { 606 error = ip_output(m, opt, ro, 607 flags | IP_RAWOUTPUT | IP_NOIPNEWID, 608 imo, so); 609 } else { 610 KASSERT((m->m_pkthdr.csum_flags & 611 (M_CSUM_UDPv4 | M_CSUM_TCPv4)) == 0); 612 KERNEL_LOCK(1, NULL); 613 error = (*ifp->if_output)(ifp, m, 614 (m->m_flags & M_MCAST) ? 615 sintocsa(rdst) : sintocsa(dst), rt); 616 KERNEL_UNLOCK_ONE(NULL); 617 } 618 } else 619 m_freem(m); 620 } 621 622 if (error == 0) 623 IP_STATINC(IP_STAT_FRAGMENTED); 624 done: 625 rtcache_free(&iproute); 626 if (sp) { 627 #ifdef IPSEC 628 KEY_FREESP(&sp); 629 #endif 630 } 631 return error; 632 bad: 633 m_freem(m); 634 goto done; 635 } 636 637 int 638 ip_fragment(struct mbuf *m, struct ifnet *ifp, u_long mtu) 639 { 640 struct ip *ip, *mhip; 641 struct mbuf *m0; 642 int len, hlen, off; 643 int mhlen, firstlen; 644 struct mbuf **mnext; 645 int sw_csum = m->m_pkthdr.csum_flags; 646 int fragments = 0; 647 int s; 648 int error = 0; 649 650 ip = mtod(m, struct ip *); 651 hlen = ip->ip_hl << 2; 652 if (ifp != NULL) 653 sw_csum &= ~ifp->if_csum_flags_tx; 654 655 len = (mtu - hlen) &~ 7; 656 if (len < 8) { 657 m_freem(m); 658 return (EMSGSIZE); 659 } 660 661 firstlen = len; 662 mnext = &m->m_nextpkt; 663 664 /* 665 * Loop through length of segment after first fragment, 666 * make new header and copy data of each part and link onto chain. 667 */ 668 m0 = m; 669 mhlen = sizeof (struct ip); 670 for (off = hlen + len; off < ntohs(ip->ip_len); off += len) { 671 MGETHDR(m, M_DONTWAIT, MT_HEADER); 672 if (m == 0) { 673 error = ENOBUFS; 674 IP_STATINC(IP_STAT_ODROPPED); 675 goto sendorfree; 676 } 677 MCLAIM(m, m0->m_owner); 678 *mnext = m; 679 mnext = &m->m_nextpkt; 680 m->m_data += max_linkhdr; 681 mhip = mtod(m, struct ip *); 682 *mhip = *ip; 683 /* we must inherit MCAST and BCAST flags */ 684 m->m_flags |= m0->m_flags & (M_MCAST|M_BCAST); 685 if (hlen > sizeof (struct ip)) { 686 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 687 mhip->ip_hl = mhlen >> 2; 688 } 689 m->m_len = mhlen; 690 mhip->ip_off = ((off - hlen) >> 3) + 691 (ntohs(ip->ip_off) & ~IP_MF); 692 if (ip->ip_off & htons(IP_MF)) 693 mhip->ip_off |= IP_MF; 694 if (off + len >= ntohs(ip->ip_len)) 695 len = ntohs(ip->ip_len) - off; 696 else 697 mhip->ip_off |= IP_MF; 698 HTONS(mhip->ip_off); 699 mhip->ip_len = htons((u_int16_t)(len + mhlen)); 700 m->m_next = m_copym(m0, off, len, M_DONTWAIT); 701 if (m->m_next == 0) { 702 error = ENOBUFS; /* ??? */ 703 IP_STATINC(IP_STAT_ODROPPED); 704 goto sendorfree; 705 } 706 m->m_pkthdr.len = mhlen + len; 707 m->m_pkthdr.rcvif = NULL; 708 mhip->ip_sum = 0; 709 KASSERT((m->m_pkthdr.csum_flags & M_CSUM_IPv4) == 0); 710 if (sw_csum & M_CSUM_IPv4) { 711 mhip->ip_sum = in_cksum(m, mhlen); 712 } else { 713 /* 714 * checksum is hw-offloaded or not necessary. 715 */ 716 m->m_pkthdr.csum_flags |= 717 m0->m_pkthdr.csum_flags & M_CSUM_IPv4; 718 m->m_pkthdr.csum_data |= mhlen << 16; 719 KASSERT(!(ifp != NULL && 720 IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) 721 || (m->m_pkthdr.csum_flags & M_CSUM_IPv4) != 0); 722 } 723 IP_STATINC(IP_STAT_OFRAGMENTS); 724 fragments++; 725 } 726 /* 727 * Update first fragment by trimming what's been copied out 728 * and updating header, then send each fragment (in order). 729 */ 730 m = m0; 731 m_adj(m, hlen + firstlen - ntohs(ip->ip_len)); 732 m->m_pkthdr.len = hlen + firstlen; 733 ip->ip_len = htons((u_int16_t)m->m_pkthdr.len); 734 ip->ip_off |= htons(IP_MF); 735 ip->ip_sum = 0; 736 if (sw_csum & M_CSUM_IPv4) { 737 ip->ip_sum = in_cksum(m, hlen); 738 m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4; 739 } else { 740 /* 741 * checksum is hw-offloaded or not necessary. 742 */ 743 KASSERT(!(ifp != NULL && IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) 744 || (m->m_pkthdr.csum_flags & M_CSUM_IPv4) != 0); 745 KASSERT(M_CSUM_DATA_IPv4_IPHL(m->m_pkthdr.csum_data) >= 746 sizeof(struct ip)); 747 } 748 sendorfree: 749 /* 750 * If there is no room for all the fragments, don't queue 751 * any of them. 752 */ 753 if (ifp != NULL) { 754 s = splnet(); 755 if (ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len < fragments && 756 error == 0) { 757 error = ENOBUFS; 758 IP_STATINC(IP_STAT_ODROPPED); 759 IFQ_INC_DROPS(&ifp->if_snd); 760 } 761 splx(s); 762 } 763 if (error) { 764 for (m = m0; m; m = m0) { 765 m0 = m->m_nextpkt; 766 m->m_nextpkt = NULL; 767 m_freem(m); 768 } 769 } 770 return (error); 771 } 772 773 /* 774 * Process a delayed payload checksum calculation. 775 */ 776 void 777 in_delayed_cksum(struct mbuf *m) 778 { 779 struct ip *ip; 780 u_int16_t csum, offset; 781 782 ip = mtod(m, struct ip *); 783 offset = ip->ip_hl << 2; 784 csum = in4_cksum(m, 0, offset, ntohs(ip->ip_len) - offset); 785 if (csum == 0 && (m->m_pkthdr.csum_flags & M_CSUM_UDPv4) != 0) 786 csum = 0xffff; 787 788 offset += M_CSUM_DATA_IPv4_OFFSET(m->m_pkthdr.csum_data); 789 790 if ((offset + sizeof(u_int16_t)) > m->m_len) { 791 /* This happen when ip options were inserted 792 printf("in_delayed_cksum: pullup len %d off %d proto %d\n", 793 m->m_len, offset, ip->ip_p); 794 */ 795 m_copyback(m, offset, sizeof(csum), (void *) &csum); 796 } else 797 *(u_int16_t *)(mtod(m, char *) + offset) = csum; 798 } 799 800 /* 801 * Determine the maximum length of the options to be inserted; 802 * we would far rather allocate too much space rather than too little. 803 */ 804 805 u_int 806 ip_optlen(struct inpcb *inp) 807 { 808 struct mbuf *m = inp->inp_options; 809 810 if (m && m->m_len > offsetof(struct ipoption, ipopt_dst)) { 811 return (m->m_len - offsetof(struct ipoption, ipopt_dst)); 812 } 813 return 0; 814 } 815 816 /* 817 * Insert IP options into preformed packet. 818 * Adjust IP destination as required for IP source routing, 819 * as indicated by a non-zero in_addr at the start of the options. 820 */ 821 static struct mbuf * 822 ip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phlen) 823 { 824 struct ipoption *p = mtod(opt, struct ipoption *); 825 struct mbuf *n; 826 struct ip *ip = mtod(m, struct ip *); 827 unsigned optlen; 828 829 optlen = opt->m_len - sizeof(p->ipopt_dst); 830 if (optlen + ntohs(ip->ip_len) > IP_MAXPACKET) 831 return (m); /* XXX should fail */ 832 if (!in_nullhost(p->ipopt_dst)) 833 ip->ip_dst = p->ipopt_dst; 834 if (M_READONLY(m) || M_LEADINGSPACE(m) < optlen) { 835 MGETHDR(n, M_DONTWAIT, MT_HEADER); 836 if (n == 0) 837 return (m); 838 MCLAIM(n, m->m_owner); 839 M_MOVE_PKTHDR(n, m); 840 m->m_len -= sizeof(struct ip); 841 m->m_data += sizeof(struct ip); 842 n->m_next = m; 843 m = n; 844 m->m_len = optlen + sizeof(struct ip); 845 m->m_data += max_linkhdr; 846 bcopy((void *)ip, mtod(m, void *), sizeof(struct ip)); 847 } else { 848 m->m_data -= optlen; 849 m->m_len += optlen; 850 memmove(mtod(m, void *), ip, sizeof(struct ip)); 851 } 852 m->m_pkthdr.len += optlen; 853 ip = mtod(m, struct ip *); 854 bcopy((void *)p->ipopt_list, (void *)(ip + 1), (unsigned)optlen); 855 *phlen = sizeof(struct ip) + optlen; 856 ip->ip_len = htons(ntohs(ip->ip_len) + optlen); 857 return (m); 858 } 859 860 /* 861 * Copy options from ip to jp, 862 * omitting those not copied during fragmentation. 863 */ 864 int 865 ip_optcopy(struct ip *ip, struct ip *jp) 866 { 867 u_char *cp, *dp; 868 int opt, optlen, cnt; 869 870 cp = (u_char *)(ip + 1); 871 dp = (u_char *)(jp + 1); 872 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 873 for (; cnt > 0; cnt -= optlen, cp += optlen) { 874 opt = cp[0]; 875 if (opt == IPOPT_EOL) 876 break; 877 if (opt == IPOPT_NOP) { 878 /* Preserve for IP mcast tunnel's LSRR alignment. */ 879 *dp++ = IPOPT_NOP; 880 optlen = 1; 881 continue; 882 } 883 884 KASSERT(cnt >= IPOPT_OLEN + sizeof(*cp)); 885 optlen = cp[IPOPT_OLEN]; 886 KASSERT(optlen >= IPOPT_OLEN + sizeof(*cp) && optlen < cnt); 887 888 /* Invalid lengths should have been caught by ip_dooptions. */ 889 if (optlen > cnt) 890 optlen = cnt; 891 if (IPOPT_COPIED(opt)) { 892 bcopy((void *)cp, (void *)dp, (unsigned)optlen); 893 dp += optlen; 894 } 895 } 896 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 897 *dp++ = IPOPT_EOL; 898 return (optlen); 899 } 900 901 /* 902 * IP socket option processing. 903 */ 904 int 905 ip_ctloutput(int op, struct socket *so, struct sockopt *sopt) 906 { 907 struct inpcb *inp = sotoinpcb(so); 908 struct ip *ip = &inp->inp_ip; 909 int inpflags = inp->inp_flags; 910 int optval = 0, error = 0; 911 912 if (sopt->sopt_level != IPPROTO_IP) { 913 if (sopt->sopt_level == SOL_SOCKET && sopt->sopt_name == SO_NOHEADER) 914 return 0; 915 return ENOPROTOOPT; 916 } 917 918 switch (op) { 919 case PRCO_SETOPT: 920 switch (sopt->sopt_name) { 921 case IP_OPTIONS: 922 #ifdef notyet 923 case IP_RETOPTS: 924 #endif 925 error = ip_pcbopts(inp, sopt); 926 break; 927 928 case IP_TOS: 929 case IP_TTL: 930 case IP_MINTTL: 931 case IP_PKTINFO: 932 case IP_RECVOPTS: 933 case IP_RECVRETOPTS: 934 case IP_RECVDSTADDR: 935 case IP_RECVIF: 936 case IP_RECVPKTINFO: 937 case IP_RECVTTL: 938 error = sockopt_getint(sopt, &optval); 939 if (error) 940 break; 941 942 switch (sopt->sopt_name) { 943 case IP_TOS: 944 ip->ip_tos = optval; 945 break; 946 947 case IP_TTL: 948 ip->ip_ttl = optval; 949 break; 950 951 case IP_MINTTL: 952 if (optval > 0 && optval <= MAXTTL) 953 inp->inp_ip_minttl = optval; 954 else 955 error = EINVAL; 956 break; 957 #define OPTSET(bit) \ 958 if (optval) \ 959 inpflags |= bit; \ 960 else \ 961 inpflags &= ~bit; 962 963 case IP_PKTINFO: 964 OPTSET(INP_PKTINFO); 965 break; 966 967 case IP_RECVOPTS: 968 OPTSET(INP_RECVOPTS); 969 break; 970 971 case IP_RECVPKTINFO: 972 OPTSET(INP_RECVPKTINFO); 973 break; 974 975 case IP_RECVRETOPTS: 976 OPTSET(INP_RECVRETOPTS); 977 break; 978 979 case IP_RECVDSTADDR: 980 OPTSET(INP_RECVDSTADDR); 981 break; 982 983 case IP_RECVIF: 984 OPTSET(INP_RECVIF); 985 break; 986 987 case IP_RECVTTL: 988 OPTSET(INP_RECVTTL); 989 break; 990 } 991 break; 992 #undef OPTSET 993 994 case IP_MULTICAST_IF: 995 case IP_MULTICAST_TTL: 996 case IP_MULTICAST_LOOP: 997 case IP_ADD_MEMBERSHIP: 998 case IP_DROP_MEMBERSHIP: 999 error = ip_setmoptions(inp, sopt); 1000 break; 1001 1002 case IP_PORTRANGE: 1003 error = sockopt_getint(sopt, &optval); 1004 if (error) 1005 break; 1006 1007 switch (optval) { 1008 case IP_PORTRANGE_DEFAULT: 1009 case IP_PORTRANGE_HIGH: 1010 inpflags &= ~(INP_LOWPORT); 1011 break; 1012 1013 case IP_PORTRANGE_LOW: 1014 inpflags |= INP_LOWPORT; 1015 break; 1016 1017 default: 1018 error = EINVAL; 1019 break; 1020 } 1021 break; 1022 1023 case IP_PORTALGO: 1024 error = sockopt_getint(sopt, &optval); 1025 if (error) 1026 break; 1027 1028 error = portalgo_algo_index_select( 1029 (struct inpcb_hdr *)inp, optval); 1030 break; 1031 1032 #if defined(IPSEC) 1033 case IP_IPSEC_POLICY: 1034 error = ipsec4_set_policy(inp, sopt->sopt_name, 1035 sopt->sopt_data, sopt->sopt_size, curlwp->l_cred); 1036 break; 1037 #endif /*IPSEC*/ 1038 1039 default: 1040 error = ENOPROTOOPT; 1041 break; 1042 } 1043 break; 1044 1045 case PRCO_GETOPT: 1046 switch (sopt->sopt_name) { 1047 case IP_OPTIONS: 1048 case IP_RETOPTS: { 1049 struct mbuf *mopts = inp->inp_options; 1050 1051 if (mopts) { 1052 struct mbuf *m; 1053 1054 m = m_copym(mopts, 0, M_COPYALL, M_DONTWAIT); 1055 if (m == NULL) { 1056 error = ENOBUFS; 1057 break; 1058 } 1059 error = sockopt_setmbuf(sopt, m); 1060 } 1061 break; 1062 } 1063 case IP_PKTINFO: 1064 case IP_TOS: 1065 case IP_TTL: 1066 case IP_MINTTL: 1067 case IP_RECVOPTS: 1068 case IP_RECVRETOPTS: 1069 case IP_RECVDSTADDR: 1070 case IP_RECVIF: 1071 case IP_RECVPKTINFO: 1072 case IP_RECVTTL: 1073 case IP_ERRORMTU: 1074 switch (sopt->sopt_name) { 1075 case IP_TOS: 1076 optval = ip->ip_tos; 1077 break; 1078 1079 case IP_TTL: 1080 optval = ip->ip_ttl; 1081 break; 1082 1083 case IP_MINTTL: 1084 optval = inp->inp_ip_minttl; 1085 break; 1086 1087 case IP_ERRORMTU: 1088 optval = inp->inp_errormtu; 1089 break; 1090 1091 #define OPTBIT(bit) (inpflags & bit ? 1 : 0) 1092 1093 case IP_PKTINFO: 1094 optval = OPTBIT(INP_PKTINFO); 1095 break; 1096 1097 case IP_RECVOPTS: 1098 optval = OPTBIT(INP_RECVOPTS); 1099 break; 1100 1101 case IP_RECVPKTINFO: 1102 optval = OPTBIT(INP_RECVPKTINFO); 1103 break; 1104 1105 case IP_RECVRETOPTS: 1106 optval = OPTBIT(INP_RECVRETOPTS); 1107 break; 1108 1109 case IP_RECVDSTADDR: 1110 optval = OPTBIT(INP_RECVDSTADDR); 1111 break; 1112 1113 case IP_RECVIF: 1114 optval = OPTBIT(INP_RECVIF); 1115 break; 1116 1117 case IP_RECVTTL: 1118 optval = OPTBIT(INP_RECVTTL); 1119 break; 1120 } 1121 error = sockopt_setint(sopt, optval); 1122 break; 1123 1124 #if 0 /* defined(IPSEC) */ 1125 case IP_IPSEC_POLICY: 1126 { 1127 struct mbuf *m = NULL; 1128 1129 /* XXX this will return EINVAL as sopt is empty */ 1130 error = ipsec4_get_policy(inp, sopt->sopt_data, 1131 sopt->sopt_size, &m); 1132 if (error == 0) 1133 error = sockopt_setmbuf(sopt, m); 1134 break; 1135 } 1136 #endif /*IPSEC*/ 1137 1138 case IP_MULTICAST_IF: 1139 case IP_MULTICAST_TTL: 1140 case IP_MULTICAST_LOOP: 1141 case IP_ADD_MEMBERSHIP: 1142 case IP_DROP_MEMBERSHIP: 1143 error = ip_getmoptions(inp, sopt); 1144 break; 1145 1146 case IP_PORTRANGE: 1147 if (inpflags & INP_LOWPORT) 1148 optval = IP_PORTRANGE_LOW; 1149 else 1150 optval = IP_PORTRANGE_DEFAULT; 1151 error = sockopt_setint(sopt, optval); 1152 break; 1153 1154 case IP_PORTALGO: 1155 optval = inp->inp_portalgo; 1156 error = sockopt_setint(sopt, optval); 1157 break; 1158 1159 default: 1160 error = ENOPROTOOPT; 1161 break; 1162 } 1163 break; 1164 } 1165 1166 if (!error) { 1167 inp->inp_flags = inpflags; 1168 } 1169 return error; 1170 } 1171 1172 /* 1173 * Set up IP options in pcb for insertion in output packets. 1174 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1175 * with destination address if source routed. 1176 */ 1177 static int 1178 ip_pcbopts(struct inpcb *inp, const struct sockopt *sopt) 1179 { 1180 struct mbuf *m; 1181 const u_char *cp; 1182 u_char *dp; 1183 int cnt; 1184 1185 /* Turn off any old options. */ 1186 if (inp->inp_options) { 1187 m_free(inp->inp_options); 1188 } 1189 inp->inp_options = NULL; 1190 if ((cnt = sopt->sopt_size) == 0) { 1191 /* Only turning off any previous options. */ 1192 return 0; 1193 } 1194 cp = sopt->sopt_data; 1195 1196 #ifndef __vax__ 1197 if (cnt % sizeof(int32_t)) 1198 return (EINVAL); 1199 #endif 1200 1201 m = m_get(M_DONTWAIT, MT_SOOPTS); 1202 if (m == NULL) 1203 return (ENOBUFS); 1204 1205 dp = mtod(m, u_char *); 1206 memset(dp, 0, sizeof(struct in_addr)); 1207 dp += sizeof(struct in_addr); 1208 m->m_len = sizeof(struct in_addr); 1209 1210 /* 1211 * IP option list according to RFC791. Each option is of the form 1212 * 1213 * [optval] [olen] [(olen - 2) data bytes] 1214 * 1215 * We validate the list and copy options to an mbuf for prepending 1216 * to data packets. The IP first-hop destination address will be 1217 * stored before actual options and is zero if unset. 1218 */ 1219 while (cnt > 0) { 1220 uint8_t optval, olen, offset; 1221 1222 optval = cp[IPOPT_OPTVAL]; 1223 1224 if (optval == IPOPT_EOL || optval == IPOPT_NOP) { 1225 olen = 1; 1226 } else { 1227 if (cnt < IPOPT_OLEN + 1) 1228 goto bad; 1229 1230 olen = cp[IPOPT_OLEN]; 1231 if (olen < IPOPT_OLEN + 1 || olen > cnt) 1232 goto bad; 1233 } 1234 1235 if (optval == IPOPT_LSRR || optval == IPOPT_SSRR) { 1236 /* 1237 * user process specifies route as: 1238 * ->A->B->C->D 1239 * D must be our final destination (but we can't 1240 * check that since we may not have connected yet). 1241 * A is first hop destination, which doesn't appear in 1242 * actual IP option, but is stored before the options. 1243 */ 1244 if (olen < IPOPT_OFFSET + 1 + sizeof(struct in_addr)) 1245 goto bad; 1246 1247 offset = cp[IPOPT_OFFSET]; 1248 memcpy(mtod(m, u_char *), cp + IPOPT_OFFSET + 1, 1249 sizeof(struct in_addr)); 1250 1251 cp += sizeof(struct in_addr); 1252 cnt -= sizeof(struct in_addr); 1253 olen -= sizeof(struct in_addr); 1254 1255 if (m->m_len + olen > MAX_IPOPTLEN + sizeof(struct in_addr)) 1256 goto bad; 1257 1258 memcpy(dp, cp, olen); 1259 dp[IPOPT_OPTVAL] = optval; 1260 dp[IPOPT_OLEN] = olen; 1261 dp[IPOPT_OFFSET] = offset; 1262 break; 1263 } else { 1264 if (m->m_len + olen > MAX_IPOPTLEN + sizeof(struct in_addr)) 1265 goto bad; 1266 1267 memcpy(dp, cp, olen); 1268 break; 1269 } 1270 1271 dp += olen; 1272 m->m_len += olen; 1273 1274 if (optval == IPOPT_EOL) 1275 break; 1276 1277 cp += olen; 1278 cnt -= olen; 1279 } 1280 1281 inp->inp_options = m; 1282 return 0; 1283 bad: 1284 (void)m_free(m); 1285 return EINVAL; 1286 } 1287 1288 /* 1289 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1290 */ 1291 static struct ifnet * 1292 ip_multicast_if(struct in_addr *a, int *ifindexp) 1293 { 1294 int ifindex; 1295 struct ifnet *ifp = NULL; 1296 struct in_ifaddr *ia; 1297 1298 if (ifindexp) 1299 *ifindexp = 0; 1300 if (ntohl(a->s_addr) >> 24 == 0) { 1301 ifindex = ntohl(a->s_addr) & 0xffffff; 1302 ifp = if_byindex(ifindex); 1303 if (!ifp) 1304 return NULL; 1305 if (ifindexp) 1306 *ifindexp = ifindex; 1307 } else { 1308 LIST_FOREACH(ia, &IN_IFADDR_HASH(a->s_addr), ia_hash) { 1309 if (in_hosteq(ia->ia_addr.sin_addr, *a) && 1310 (ia->ia_ifp->if_flags & IFF_MULTICAST) != 0) { 1311 ifp = ia->ia_ifp; 1312 break; 1313 } 1314 } 1315 } 1316 return ifp; 1317 } 1318 1319 static int 1320 ip_getoptval(const struct sockopt *sopt, u_int8_t *val, u_int maxval) 1321 { 1322 u_int tval; 1323 u_char cval; 1324 int error; 1325 1326 if (sopt == NULL) 1327 return EINVAL; 1328 1329 switch (sopt->sopt_size) { 1330 case sizeof(u_char): 1331 error = sockopt_get(sopt, &cval, sizeof(u_char)); 1332 tval = cval; 1333 break; 1334 1335 case sizeof(u_int): 1336 error = sockopt_get(sopt, &tval, sizeof(u_int)); 1337 break; 1338 1339 default: 1340 error = EINVAL; 1341 } 1342 1343 if (error) 1344 return error; 1345 1346 if (tval > maxval) 1347 return EINVAL; 1348 1349 *val = tval; 1350 return 0; 1351 } 1352 1353 /* 1354 * Set the IP multicast options in response to user setsockopt(). 1355 */ 1356 static int 1357 ip_setmoptions(struct inpcb *inp, const struct sockopt *sopt) 1358 { 1359 struct ip_moptions *imo = inp->inp_moptions; 1360 struct in_addr addr; 1361 struct ip_mreq lmreq, *mreq; 1362 struct ifnet *ifp; 1363 int i, ifindex, error = 0; 1364 1365 if (!imo) { 1366 /* 1367 * No multicast option buffer attached to the pcb; 1368 * allocate one and initialize to default values. 1369 */ 1370 imo = kmem_intr_alloc(sizeof(*imo), KM_NOSLEEP); 1371 if (imo == NULL) 1372 return ENOBUFS; 1373 1374 imo->imo_multicast_ifp = NULL; 1375 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1376 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1377 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1378 imo->imo_num_memberships = 0; 1379 inp->inp_moptions = imo; 1380 } 1381 1382 switch (sopt->sopt_name) { 1383 case IP_MULTICAST_IF: 1384 /* 1385 * Select the interface for outgoing multicast packets. 1386 */ 1387 error = sockopt_get(sopt, &addr, sizeof(addr)); 1388 if (error) 1389 break; 1390 1391 /* 1392 * INADDR_ANY is used to remove a previous selection. 1393 * When no interface is selected, a default one is 1394 * chosen every time a multicast packet is sent. 1395 */ 1396 if (in_nullhost(addr)) { 1397 imo->imo_multicast_ifp = NULL; 1398 break; 1399 } 1400 /* 1401 * The selected interface is identified by its local 1402 * IP address. Find the interface and confirm that 1403 * it supports multicasting. 1404 */ 1405 ifp = ip_multicast_if(&addr, &ifindex); 1406 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1407 error = EADDRNOTAVAIL; 1408 break; 1409 } 1410 imo->imo_multicast_ifp = ifp; 1411 if (ifindex) 1412 imo->imo_multicast_addr = addr; 1413 else 1414 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1415 break; 1416 1417 case IP_MULTICAST_TTL: 1418 /* 1419 * Set the IP time-to-live for outgoing multicast packets. 1420 */ 1421 error = ip_getoptval(sopt, &imo->imo_multicast_ttl, MAXTTL); 1422 break; 1423 1424 case IP_MULTICAST_LOOP: 1425 /* 1426 * Set the loopback flag for outgoing multicast packets. 1427 * Must be zero or one. 1428 */ 1429 error = ip_getoptval(sopt, &imo->imo_multicast_loop, 1); 1430 break; 1431 1432 case IP_ADD_MEMBERSHIP: 1433 /* 1434 * Add a multicast group membership. 1435 * Group must be a valid IP multicast address. 1436 */ 1437 error = sockopt_get(sopt, &lmreq, sizeof(lmreq)); 1438 if (error) 1439 break; 1440 1441 mreq = &lmreq; 1442 1443 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1444 error = EINVAL; 1445 break; 1446 } 1447 /* 1448 * If no interface address was provided, use the interface of 1449 * the route to the given multicast address. 1450 */ 1451 if (in_nullhost(mreq->imr_interface)) { 1452 struct rtentry *rt; 1453 union { 1454 struct sockaddr dst; 1455 struct sockaddr_in dst4; 1456 } u; 1457 struct route ro; 1458 1459 memset(&ro, 0, sizeof(ro)); 1460 1461 sockaddr_in_init(&u.dst4, &mreq->imr_multiaddr, 0); 1462 rtcache_setdst(&ro, &u.dst); 1463 ifp = (rt = rtcache_init(&ro)) != NULL ? rt->rt_ifp 1464 : NULL; 1465 rtcache_free(&ro); 1466 } else { 1467 ifp = ip_multicast_if(&mreq->imr_interface, NULL); 1468 } 1469 /* 1470 * See if we found an interface, and confirm that it 1471 * supports multicast. 1472 */ 1473 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1474 error = EADDRNOTAVAIL; 1475 break; 1476 } 1477 /* 1478 * See if the membership already exists or if all the 1479 * membership slots are full. 1480 */ 1481 for (i = 0; i < imo->imo_num_memberships; ++i) { 1482 if (imo->imo_membership[i]->inm_ifp == ifp && 1483 in_hosteq(imo->imo_membership[i]->inm_addr, 1484 mreq->imr_multiaddr)) 1485 break; 1486 } 1487 if (i < imo->imo_num_memberships) { 1488 error = EADDRINUSE; 1489 break; 1490 } 1491 if (i == IP_MAX_MEMBERSHIPS) { 1492 error = ETOOMANYREFS; 1493 break; 1494 } 1495 /* 1496 * Everything looks good; add a new record to the multicast 1497 * address list for the given interface. 1498 */ 1499 if ((imo->imo_membership[i] = 1500 in_addmulti(&mreq->imr_multiaddr, ifp)) == NULL) { 1501 error = ENOBUFS; 1502 break; 1503 } 1504 ++imo->imo_num_memberships; 1505 break; 1506 1507 case IP_DROP_MEMBERSHIP: 1508 /* 1509 * Drop a multicast group membership. 1510 * Group must be a valid IP multicast address. 1511 */ 1512 error = sockopt_get(sopt, &lmreq, sizeof(lmreq)); 1513 if (error) 1514 break; 1515 1516 mreq = &lmreq; 1517 1518 if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { 1519 error = EINVAL; 1520 break; 1521 } 1522 /* 1523 * If an interface address was specified, get a pointer 1524 * to its ifnet structure. 1525 */ 1526 if (in_nullhost(mreq->imr_interface)) 1527 ifp = NULL; 1528 else { 1529 ifp = ip_multicast_if(&mreq->imr_interface, NULL); 1530 if (ifp == NULL) { 1531 error = EADDRNOTAVAIL; 1532 break; 1533 } 1534 } 1535 /* 1536 * Find the membership in the membership array. 1537 */ 1538 for (i = 0; i < imo->imo_num_memberships; ++i) { 1539 if ((ifp == NULL || 1540 imo->imo_membership[i]->inm_ifp == ifp) && 1541 in_hosteq(imo->imo_membership[i]->inm_addr, 1542 mreq->imr_multiaddr)) 1543 break; 1544 } 1545 if (i == imo->imo_num_memberships) { 1546 error = EADDRNOTAVAIL; 1547 break; 1548 } 1549 /* 1550 * Give up the multicast address record to which the 1551 * membership points. 1552 */ 1553 in_delmulti(imo->imo_membership[i]); 1554 /* 1555 * Remove the gap in the membership array. 1556 */ 1557 for (++i; i < imo->imo_num_memberships; ++i) 1558 imo->imo_membership[i-1] = imo->imo_membership[i]; 1559 --imo->imo_num_memberships; 1560 break; 1561 1562 default: 1563 error = EOPNOTSUPP; 1564 break; 1565 } 1566 1567 /* 1568 * If all options have default values, no need to keep the mbuf. 1569 */ 1570 if (imo->imo_multicast_ifp == NULL && 1571 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 1572 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 1573 imo->imo_num_memberships == 0) { 1574 kmem_free(imo, sizeof(*imo)); 1575 inp->inp_moptions = NULL; 1576 } 1577 1578 return error; 1579 } 1580 1581 /* 1582 * Return the IP multicast options in response to user getsockopt(). 1583 */ 1584 static int 1585 ip_getmoptions(struct inpcb *inp, struct sockopt *sopt) 1586 { 1587 struct ip_moptions *imo = inp->inp_moptions; 1588 struct in_addr addr; 1589 struct in_ifaddr *ia; 1590 uint8_t optval; 1591 int error = 0; 1592 1593 switch (sopt->sopt_name) { 1594 case IP_MULTICAST_IF: 1595 if (imo == NULL || imo->imo_multicast_ifp == NULL) 1596 addr = zeroin_addr; 1597 else if (imo->imo_multicast_addr.s_addr) { 1598 /* return the value user has set */ 1599 addr = imo->imo_multicast_addr; 1600 } else { 1601 IFP_TO_IA(imo->imo_multicast_ifp, ia); 1602 addr = ia ? ia->ia_addr.sin_addr : zeroin_addr; 1603 } 1604 error = sockopt_set(sopt, &addr, sizeof(addr)); 1605 break; 1606 1607 case IP_MULTICAST_TTL: 1608 optval = imo ? imo->imo_multicast_ttl 1609 : IP_DEFAULT_MULTICAST_TTL; 1610 1611 error = sockopt_set(sopt, &optval, sizeof(optval)); 1612 break; 1613 1614 case IP_MULTICAST_LOOP: 1615 optval = imo ? imo->imo_multicast_loop 1616 : IP_DEFAULT_MULTICAST_LOOP; 1617 1618 error = sockopt_set(sopt, &optval, sizeof(optval)); 1619 break; 1620 1621 default: 1622 error = EOPNOTSUPP; 1623 } 1624 1625 return error; 1626 } 1627 1628 /* 1629 * Discard the IP multicast options. 1630 */ 1631 void 1632 ip_freemoptions(struct ip_moptions *imo) 1633 { 1634 int i; 1635 1636 if (imo != NULL) { 1637 for (i = 0; i < imo->imo_num_memberships; ++i) 1638 in_delmulti(imo->imo_membership[i]); 1639 kmem_free(imo, sizeof(*imo)); 1640 } 1641 } 1642 1643 /* 1644 * Routine called from ip_output() to loop back a copy of an IP multicast 1645 * packet to the input queue of a specified interface. Note that this 1646 * calls the output routine of the loopback "driver", but with an interface 1647 * pointer that might NOT be lo0ifp -- easier than replicating that code here. 1648 */ 1649 static void 1650 ip_mloopback(struct ifnet *ifp, struct mbuf *m, const struct sockaddr_in *dst) 1651 { 1652 struct ip *ip; 1653 struct mbuf *copym; 1654 1655 copym = m_copypacket(m, M_DONTWAIT); 1656 if (copym != NULL 1657 && (copym->m_flags & M_EXT || copym->m_len < sizeof(struct ip))) 1658 copym = m_pullup(copym, sizeof(struct ip)); 1659 if (copym == NULL) 1660 return; 1661 /* 1662 * We don't bother to fragment if the IP length is greater 1663 * than the interface's MTU. Can this possibly matter? 1664 */ 1665 ip = mtod(copym, struct ip *); 1666 1667 if (copym->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 1668 in_delayed_cksum(copym); 1669 copym->m_pkthdr.csum_flags &= 1670 ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 1671 } 1672 1673 ip->ip_sum = 0; 1674 ip->ip_sum = in_cksum(copym, ip->ip_hl << 2); 1675 (void)looutput(ifp, copym, sintocsa(dst), NULL); 1676 } 1677