1 /* $NetBSD: ip_output.c,v 1.255 2016/05/09 07:02:10 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) 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 1.255 2016/05/09 07:02:10 ozaki-r Exp $"); 95 96 #ifdef _KERNEL_OPT 97 #include "opt_inet.h" 98 #include "opt_ipsec.h" 99 #include "opt_mrouting.h" 100 #include "opt_net_mpsafe.h" 101 #include "opt_mpls.h" 102 #endif 103 104 #include <sys/param.h> 105 #include <sys/kmem.h> 106 #include <sys/mbuf.h> 107 #include <sys/protosw.h> 108 #include <sys/socket.h> 109 #include <sys/socketvar.h> 110 #include <sys/kauth.h> 111 #ifdef IPSEC 112 #include <sys/domain.h> 113 #endif 114 #include <sys/systm.h> 115 116 #include <net/if.h> 117 #include <net/if_types.h> 118 #include <net/route.h> 119 #include <net/pfil.h> 120 121 #include <netinet/in.h> 122 #include <netinet/in_systm.h> 123 #include <netinet/ip.h> 124 #include <netinet/in_pcb.h> 125 #include <netinet/in_var.h> 126 #include <netinet/ip_var.h> 127 #include <netinet/ip_private.h> 128 #include <netinet/in_offload.h> 129 #include <netinet/portalgo.h> 130 #include <netinet/udp.h> 131 132 #ifdef INET6 133 #include <netinet6/ip6_var.h> 134 #endif 135 136 #ifdef MROUTING 137 #include <netinet/ip_mroute.h> 138 #endif 139 140 #ifdef IPSEC 141 #include <netipsec/ipsec.h> 142 #include <netipsec/key.h> 143 #endif 144 145 #ifdef MPLS 146 #include <netmpls/mpls.h> 147 #include <netmpls/mpls_var.h> 148 #endif 149 150 static int ip_pcbopts(struct inpcb *, const struct sockopt *); 151 static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *); 152 static struct ifnet *ip_multicast_if(struct in_addr *, int *); 153 static void ip_mloopback(struct ifnet *, struct mbuf *, 154 const struct sockaddr_in *); 155 156 extern pfil_head_t *inet_pfil_hook; /* XXX */ 157 158 int ip_do_loopback_cksum = 0; 159 160 static int 161 ip_mark_mpls(struct ifnet * const ifp, struct mbuf * const m, 162 const struct rtentry *rt) 163 { 164 int error = 0; 165 #ifdef MPLS 166 union mpls_shim msh; 167 168 if (rt == NULL || rt_gettag(rt) == NULL || 169 rt_gettag(rt)->sa_family != AF_MPLS || 170 (m->m_flags & (M_MCAST | M_BCAST)) != 0 || 171 ifp->if_type != IFT_ETHER) 172 return 0; 173 174 msh.s_addr = MPLS_GETSADDR(rt); 175 if (msh.shim.label != MPLS_LABEL_IMPLNULL) { 176 struct m_tag *mtag; 177 /* 178 * XXX tentative solution to tell ether_output 179 * it's MPLS. Need some more efficient solution. 180 */ 181 mtag = m_tag_get(PACKET_TAG_MPLS, 182 sizeof(int) /* dummy */, 183 M_NOWAIT); 184 if (mtag == NULL) 185 return ENOMEM; 186 m_tag_prepend(m, mtag); 187 } 188 #endif 189 return error; 190 } 191 192 /* 193 * Send an IP packet to a host. 194 */ 195 int 196 ip_if_output(struct ifnet * const ifp, struct mbuf * const m, 197 const struct sockaddr * const dst, const struct rtentry *rt) 198 { 199 int error = 0; 200 201 if (rt != NULL) { 202 error = rt_check_reject_route(rt, ifp); 203 if (error != 0) { 204 m_freem(m); 205 return error; 206 } 207 } 208 209 error = ip_mark_mpls(ifp, m, rt); 210 if (error != 0) { 211 m_freem(m); 212 return error; 213 } 214 215 #ifndef NET_MPSAFE 216 KERNEL_LOCK(1, NULL); 217 #endif 218 219 error = (*ifp->if_output)(ifp, m, dst, rt); 220 221 #ifndef NET_MPSAFE 222 KERNEL_UNLOCK_ONE(NULL); 223 #endif 224 return error; 225 } 226 227 /* 228 * IP output. The packet in mbuf chain m contains a skeletal IP 229 * header (with len, off, ttl, proto, tos, src, dst). 230 * The mbuf chain containing the packet will be freed. 231 * The mbuf opt, if present, will not be freed. 232 */ 233 int 234 ip_output(struct mbuf *m0, struct mbuf *opt, struct route *ro, int flags, 235 struct ip_moptions *imo, struct socket *so) 236 { 237 struct rtentry *rt; 238 struct ip *ip; 239 struct ifnet *ifp; 240 struct mbuf *m = m0; 241 int hlen = sizeof (struct ip); 242 int len, error = 0; 243 struct route iproute; 244 const struct sockaddr_in *dst; 245 struct in_ifaddr *ia; 246 int isbroadcast; 247 int sw_csum; 248 u_long mtu; 249 #ifdef IPSEC 250 struct secpolicy *sp = NULL; 251 #endif 252 bool natt_frag = false; 253 bool rtmtu_nolock; 254 union { 255 struct sockaddr dst; 256 struct sockaddr_in dst4; 257 } u; 258 struct sockaddr *rdst = &u.dst; /* real IP destination, as opposed 259 * to the nexthop 260 */ 261 262 len = 0; 263 264 MCLAIM(m, &ip_tx_mowner); 265 266 KASSERT((m->m_flags & M_PKTHDR) != 0); 267 KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_TCPv6|M_CSUM_UDPv6)) == 0); 268 KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) != 269 (M_CSUM_TCPv4|M_CSUM_UDPv4)); 270 271 if (opt) { 272 m = ip_insertoptions(m, opt, &len); 273 if (len >= sizeof(struct ip)) 274 hlen = len; 275 } 276 ip = mtod(m, struct ip *); 277 278 /* 279 * Fill in IP header. 280 */ 281 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 282 ip->ip_v = IPVERSION; 283 ip->ip_off = htons(0); 284 /* ip->ip_id filled in after we find out source ia */ 285 ip->ip_hl = hlen >> 2; 286 IP_STATINC(IP_STAT_LOCALOUT); 287 } else { 288 hlen = ip->ip_hl << 2; 289 } 290 291 /* 292 * Route packet. 293 */ 294 if (ro == NULL) { 295 memset(&iproute, 0, sizeof(iproute)); 296 ro = &iproute; 297 } 298 sockaddr_in_init(&u.dst4, &ip->ip_dst, 0); 299 dst = satocsin(rtcache_getdst(ro)); 300 301 /* 302 * If there is a cached route, check that it is to the same 303 * destination and is still up. If not, free it and try again. 304 * The address family should also be checked in case of sharing 305 * the cache with IPv6. 306 */ 307 if (dst && (dst->sin_family != AF_INET || 308 !in_hosteq(dst->sin_addr, ip->ip_dst))) 309 rtcache_free(ro); 310 311 if ((rt = rtcache_validate(ro)) == NULL && 312 (rt = rtcache_update(ro, 1)) == NULL) { 313 dst = &u.dst4; 314 error = rtcache_setdst(ro, &u.dst); 315 if (error != 0) 316 goto bad; 317 } 318 319 /* 320 * If routing to interface only, short circuit routing lookup. 321 */ 322 if (flags & IP_ROUTETOIF) { 323 if ((ia = ifatoia(ifa_ifwithladdr(sintocsa(dst)))) == NULL) { 324 IP_STATINC(IP_STAT_NOROUTE); 325 error = ENETUNREACH; 326 goto bad; 327 } 328 ifp = ia->ia_ifp; 329 mtu = ifp->if_mtu; 330 ip->ip_ttl = 1; 331 isbroadcast = in_broadcast(dst->sin_addr, ifp); 332 } else if ((IN_MULTICAST(ip->ip_dst.s_addr) || 333 ip->ip_dst.s_addr == INADDR_BROADCAST) && 334 imo != NULL && imo->imo_multicast_ifp != NULL) { 335 ifp = imo->imo_multicast_ifp; 336 mtu = ifp->if_mtu; 337 IFP_TO_IA(ifp, ia); 338 isbroadcast = 0; 339 } else { 340 if (rt == NULL) 341 rt = rtcache_init(ro); 342 if (rt == NULL) { 343 IP_STATINC(IP_STAT_NOROUTE); 344 error = EHOSTUNREACH; 345 goto bad; 346 } 347 ia = ifatoia(rt->rt_ifa); 348 ifp = rt->rt_ifp; 349 if ((mtu = rt->rt_rmx.rmx_mtu) == 0) 350 mtu = ifp->if_mtu; 351 rt->rt_use++; 352 if (rt->rt_flags & RTF_GATEWAY) 353 dst = satosin(rt->rt_gateway); 354 if (rt->rt_flags & RTF_HOST) 355 isbroadcast = rt->rt_flags & RTF_BROADCAST; 356 else 357 isbroadcast = in_broadcast(dst->sin_addr, ifp); 358 } 359 rtmtu_nolock = rt && (rt->rt_rmx.rmx_locks & RTV_MTU) == 0; 360 361 if (IN_MULTICAST(ip->ip_dst.s_addr) || 362 (ip->ip_dst.s_addr == INADDR_BROADCAST)) { 363 bool inmgroup; 364 365 m->m_flags |= (ip->ip_dst.s_addr == INADDR_BROADCAST) ? 366 M_BCAST : M_MCAST; 367 /* 368 * See if the caller provided any multicast options 369 */ 370 if (imo != NULL) 371 ip->ip_ttl = imo->imo_multicast_ttl; 372 else 373 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 374 375 /* 376 * if we don't know the outgoing ifp yet, we can't generate 377 * output 378 */ 379 if (!ifp) { 380 IP_STATINC(IP_STAT_NOROUTE); 381 error = ENETUNREACH; 382 goto bad; 383 } 384 385 /* 386 * If the packet is multicast or broadcast, confirm that 387 * the outgoing interface can transmit it. 388 */ 389 if (((m->m_flags & M_MCAST) && 390 (ifp->if_flags & IFF_MULTICAST) == 0) || 391 ((m->m_flags & M_BCAST) && 392 (ifp->if_flags & (IFF_BROADCAST|IFF_POINTOPOINT)) == 0)) { 393 IP_STATINC(IP_STAT_NOROUTE); 394 error = ENETUNREACH; 395 goto bad; 396 } 397 /* 398 * If source address not specified yet, use an address 399 * of outgoing interface. 400 */ 401 if (in_nullhost(ip->ip_src)) { 402 struct in_ifaddr *xia; 403 struct ifaddr *xifa; 404 405 IFP_TO_IA(ifp, xia); 406 if (!xia) { 407 error = EADDRNOTAVAIL; 408 goto bad; 409 } 410 xifa = &xia->ia_ifa; 411 if (xifa->ifa_getifa != NULL) { 412 xia = ifatoia((*xifa->ifa_getifa)(xifa, rdst)); 413 if (xia == NULL) { 414 error = EADDRNOTAVAIL; 415 goto bad; 416 } 417 } 418 ip->ip_src = xia->ia_addr.sin_addr; 419 } 420 421 inmgroup = in_multi_group(ip->ip_dst, ifp, flags); 422 if (inmgroup && (imo == NULL || imo->imo_multicast_loop)) { 423 /* 424 * If we belong to the destination multicast group 425 * on the outgoing interface, and the caller did not 426 * forbid loopback, loop back a copy. 427 */ 428 ip_mloopback(ifp, m, &u.dst4); 429 } 430 #ifdef MROUTING 431 else { 432 /* 433 * If we are acting as a multicast router, perform 434 * multicast forwarding as if the packet had just 435 * arrived on the interface to which we are about 436 * to send. The multicast forwarding function 437 * recursively calls this function, using the 438 * IP_FORWARDING flag to prevent infinite recursion. 439 * 440 * Multicasts that are looped back by ip_mloopback(), 441 * above, will be forwarded by the ip_input() routine, 442 * if necessary. 443 */ 444 extern struct socket *ip_mrouter; 445 446 if (ip_mrouter && (flags & IP_FORWARDING) == 0) { 447 if (ip_mforward(m, ifp) != 0) { 448 m_freem(m); 449 goto done; 450 } 451 } 452 } 453 #endif 454 /* 455 * Multicasts with a time-to-live of zero may be looped- 456 * back, above, but must not be transmitted on a network. 457 * Also, multicasts addressed to the loopback interface 458 * are not sent -- the above call to ip_mloopback() will 459 * loop back a copy if this host actually belongs to the 460 * destination group on the loopback interface. 461 */ 462 if (ip->ip_ttl == 0 || (ifp->if_flags & IFF_LOOPBACK) != 0) { 463 m_freem(m); 464 goto done; 465 } 466 goto sendit; 467 } 468 469 /* 470 * If source address not specified yet, use address 471 * of outgoing interface. 472 */ 473 if (in_nullhost(ip->ip_src)) { 474 struct ifaddr *xifa; 475 476 xifa = &ia->ia_ifa; 477 if (xifa->ifa_getifa != NULL) { 478 ia = ifatoia((*xifa->ifa_getifa)(xifa, rdst)); 479 if (ia == NULL) { 480 error = EADDRNOTAVAIL; 481 goto bad; 482 } 483 } 484 ip->ip_src = ia->ia_addr.sin_addr; 485 } 486 487 /* 488 * packets with Class-D address as source are not valid per 489 * RFC 1112 490 */ 491 if (IN_MULTICAST(ip->ip_src.s_addr)) { 492 IP_STATINC(IP_STAT_ODROPPED); 493 error = EADDRNOTAVAIL; 494 goto bad; 495 } 496 497 /* 498 * Look for broadcast address and and verify user is allowed to 499 * send such a packet. 500 */ 501 if (isbroadcast) { 502 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 503 error = EADDRNOTAVAIL; 504 goto bad; 505 } 506 if ((flags & IP_ALLOWBROADCAST) == 0) { 507 error = EACCES; 508 goto bad; 509 } 510 /* don't allow broadcast messages to be fragmented */ 511 if (ntohs(ip->ip_len) > ifp->if_mtu) { 512 error = EMSGSIZE; 513 goto bad; 514 } 515 m->m_flags |= M_BCAST; 516 } else 517 m->m_flags &= ~M_BCAST; 518 519 sendit: 520 if ((flags & (IP_FORWARDING|IP_NOIPNEWID)) == 0) { 521 if (m->m_pkthdr.len < IP_MINFRAGSIZE) { 522 ip->ip_id = 0; 523 } else if ((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) { 524 ip->ip_id = ip_newid(ia); 525 } else { 526 527 /* 528 * TSO capable interfaces (typically?) increment 529 * ip_id for each segment. 530 * "allocate" enough ids here to increase the chance 531 * for them to be unique. 532 * 533 * note that the following calculation is not 534 * needed to be precise. wasting some ip_id is fine. 535 */ 536 537 unsigned int segsz = m->m_pkthdr.segsz; 538 unsigned int datasz = ntohs(ip->ip_len) - hlen; 539 unsigned int num = howmany(datasz, segsz); 540 541 ip->ip_id = ip_newid_range(ia, num); 542 } 543 } 544 545 /* 546 * If we're doing Path MTU Discovery, we need to set DF unless 547 * the route's MTU is locked. 548 */ 549 if ((flags & IP_MTUDISC) != 0 && rtmtu_nolock) { 550 ip->ip_off |= htons(IP_DF); 551 } 552 553 #ifdef IPSEC 554 if (ipsec_used) { 555 bool ipsec_done = false; 556 557 /* Perform IPsec processing, if any. */ 558 error = ipsec4_output(m, so, flags, &sp, &mtu, &natt_frag, 559 &ipsec_done); 560 if (error || ipsec_done) 561 goto done; 562 } 563 #endif 564 565 /* 566 * Run through list of hooks for output packets. 567 */ 568 error = pfil_run_hooks(inet_pfil_hook, &m, ifp, PFIL_OUT); 569 if (error) 570 goto done; 571 if (m == NULL) 572 goto done; 573 574 ip = mtod(m, struct ip *); 575 hlen = ip->ip_hl << 2; 576 577 m->m_pkthdr.csum_data |= hlen << 16; 578 579 #if IFA_STATS 580 /* 581 * search for the source address structure to 582 * maintain output statistics. 583 */ 584 INADDR_TO_IA(ip->ip_src, ia); 585 #endif 586 587 /* Maybe skip checksums on loopback interfaces. */ 588 if (IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) { 589 m->m_pkthdr.csum_flags |= M_CSUM_IPv4; 590 } 591 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_csum_flags_tx; 592 /* 593 * If small enough for mtu of path, or if using TCP segmentation 594 * offload, can just send directly. 595 */ 596 if (ntohs(ip->ip_len) <= mtu || 597 (m->m_pkthdr.csum_flags & M_CSUM_TSOv4) != 0) { 598 const struct sockaddr *sa; 599 600 #if IFA_STATS 601 if (ia) 602 ia->ia_ifa.ifa_data.ifad_outbytes += ntohs(ip->ip_len); 603 #endif 604 /* 605 * Always initialize the sum to 0! Some HW assisted 606 * checksumming requires this. 607 */ 608 ip->ip_sum = 0; 609 610 if ((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) { 611 /* 612 * Perform any checksums that the hardware can't do 613 * for us. 614 * 615 * XXX Does any hardware require the {th,uh}_sum 616 * XXX fields to be 0? 617 */ 618 if (sw_csum & M_CSUM_IPv4) { 619 KASSERT(IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)); 620 ip->ip_sum = in_cksum(m, hlen); 621 m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4; 622 } 623 if (sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 624 if (IN_NEED_CHECKSUM(ifp, 625 sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4))) { 626 in_delayed_cksum(m); 627 } 628 m->m_pkthdr.csum_flags &= 629 ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 630 } 631 } 632 633 sa = (m->m_flags & M_MCAST) ? sintocsa(rdst) : sintocsa(dst); 634 if (__predict_true( 635 (m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0 || 636 (ifp->if_capenable & IFCAP_TSOv4) != 0)) { 637 error = ip_if_output(ifp, m, sa, rt); 638 } else { 639 error = ip_tso_output(ifp, m, sa, rt); 640 } 641 goto done; 642 } 643 644 /* 645 * We can't use HW checksumming if we're about to 646 * to fragment the packet. 647 * 648 * XXX Some hardware can do this. 649 */ 650 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 651 if (IN_NEED_CHECKSUM(ifp, 652 m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4))) { 653 in_delayed_cksum(m); 654 } 655 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 656 } 657 658 /* 659 * Too large for interface; fragment if possible. 660 * Must be able to put at least 8 bytes per fragment. 661 */ 662 if (ntohs(ip->ip_off) & IP_DF) { 663 if (flags & IP_RETURNMTU) { 664 struct inpcb *inp; 665 666 KASSERT(so && solocked(so)); 667 inp = sotoinpcb(so); 668 inp->inp_errormtu = mtu; 669 } 670 error = EMSGSIZE; 671 IP_STATINC(IP_STAT_CANTFRAG); 672 goto bad; 673 } 674 675 error = ip_fragment(m, ifp, mtu); 676 if (error) { 677 m = NULL; 678 goto bad; 679 } 680 681 for (; m; m = m0) { 682 m0 = m->m_nextpkt; 683 m->m_nextpkt = 0; 684 if (error) { 685 m_freem(m); 686 continue; 687 } 688 #if IFA_STATS 689 if (ia) 690 ia->ia_ifa.ifa_data.ifad_outbytes += ntohs(ip->ip_len); 691 #endif 692 /* 693 * If we get there, the packet has not been handled by 694 * IPsec whereas it should have. Now that it has been 695 * fragmented, re-inject it in ip_output so that IPsec 696 * processing can occur. 697 */ 698 if (natt_frag) { 699 error = ip_output(m, opt, ro, 700 flags | IP_RAWOUTPUT | IP_NOIPNEWID, 701 imo, so); 702 } else { 703 KASSERT((m->m_pkthdr.csum_flags & 704 (M_CSUM_UDPv4 | M_CSUM_TCPv4)) == 0); 705 error = ip_if_output(ifp, m, 706 (m->m_flags & M_MCAST) ? 707 sintocsa(rdst) : sintocsa(dst), rt); 708 } 709 } 710 if (error == 0) { 711 IP_STATINC(IP_STAT_FRAGMENTED); 712 } 713 done: 714 if (ro == &iproute) { 715 rtcache_free(&iproute); 716 } 717 #ifdef IPSEC 718 if (sp) { 719 KEY_FREESP(&sp); 720 } 721 #endif 722 return error; 723 bad: 724 m_freem(m); 725 goto done; 726 } 727 728 int 729 ip_fragment(struct mbuf *m, struct ifnet *ifp, u_long mtu) 730 { 731 struct ip *ip, *mhip; 732 struct mbuf *m0; 733 int len, hlen, off; 734 int mhlen, firstlen; 735 struct mbuf **mnext; 736 int sw_csum = m->m_pkthdr.csum_flags; 737 int fragments = 0; 738 int s; 739 int error = 0; 740 741 ip = mtod(m, struct ip *); 742 hlen = ip->ip_hl << 2; 743 if (ifp != NULL) 744 sw_csum &= ~ifp->if_csum_flags_tx; 745 746 len = (mtu - hlen) &~ 7; 747 if (len < 8) { 748 m_freem(m); 749 return (EMSGSIZE); 750 } 751 752 firstlen = len; 753 mnext = &m->m_nextpkt; 754 755 /* 756 * Loop through length of segment after first fragment, 757 * make new header and copy data of each part and link onto chain. 758 */ 759 m0 = m; 760 mhlen = sizeof (struct ip); 761 for (off = hlen + len; off < ntohs(ip->ip_len); off += len) { 762 MGETHDR(m, M_DONTWAIT, MT_HEADER); 763 if (m == 0) { 764 error = ENOBUFS; 765 IP_STATINC(IP_STAT_ODROPPED); 766 goto sendorfree; 767 } 768 MCLAIM(m, m0->m_owner); 769 *mnext = m; 770 mnext = &m->m_nextpkt; 771 m->m_data += max_linkhdr; 772 mhip = mtod(m, struct ip *); 773 *mhip = *ip; 774 /* we must inherit MCAST and BCAST flags */ 775 m->m_flags |= m0->m_flags & (M_MCAST|M_BCAST); 776 if (hlen > sizeof (struct ip)) { 777 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 778 mhip->ip_hl = mhlen >> 2; 779 } 780 m->m_len = mhlen; 781 mhip->ip_off = ((off - hlen) >> 3) + 782 (ntohs(ip->ip_off) & ~IP_MF); 783 if (ip->ip_off & htons(IP_MF)) 784 mhip->ip_off |= IP_MF; 785 if (off + len >= ntohs(ip->ip_len)) 786 len = ntohs(ip->ip_len) - off; 787 else 788 mhip->ip_off |= IP_MF; 789 HTONS(mhip->ip_off); 790 mhip->ip_len = htons((u_int16_t)(len + mhlen)); 791 m->m_next = m_copym(m0, off, len, M_DONTWAIT); 792 if (m->m_next == 0) { 793 error = ENOBUFS; /* ??? */ 794 IP_STATINC(IP_STAT_ODROPPED); 795 goto sendorfree; 796 } 797 m->m_pkthdr.len = mhlen + len; 798 m->m_pkthdr.rcvif = NULL; 799 mhip->ip_sum = 0; 800 KASSERT((m->m_pkthdr.csum_flags & M_CSUM_IPv4) == 0); 801 if (sw_csum & M_CSUM_IPv4) { 802 mhip->ip_sum = in_cksum(m, mhlen); 803 } else { 804 /* 805 * checksum is hw-offloaded or not necessary. 806 */ 807 m->m_pkthdr.csum_flags |= 808 m0->m_pkthdr.csum_flags & M_CSUM_IPv4; 809 m->m_pkthdr.csum_data |= mhlen << 16; 810 KASSERT(!(ifp != NULL && 811 IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) || 812 (m->m_pkthdr.csum_flags & M_CSUM_IPv4) != 0); 813 } 814 IP_STATINC(IP_STAT_OFRAGMENTS); 815 fragments++; 816 } 817 /* 818 * Update first fragment by trimming what's been copied out 819 * and updating header, then send each fragment (in order). 820 */ 821 m = m0; 822 m_adj(m, hlen + firstlen - ntohs(ip->ip_len)); 823 m->m_pkthdr.len = hlen + firstlen; 824 ip->ip_len = htons((u_int16_t)m->m_pkthdr.len); 825 ip->ip_off |= htons(IP_MF); 826 ip->ip_sum = 0; 827 if (sw_csum & M_CSUM_IPv4) { 828 ip->ip_sum = in_cksum(m, hlen); 829 m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4; 830 } else { 831 /* 832 * checksum is hw-offloaded or not necessary. 833 */ 834 KASSERT(!(ifp != NULL && IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) || 835 (m->m_pkthdr.csum_flags & M_CSUM_IPv4) != 0); 836 KASSERT(M_CSUM_DATA_IPv4_IPHL(m->m_pkthdr.csum_data) >= 837 sizeof(struct ip)); 838 } 839 sendorfree: 840 /* 841 * If there is no room for all the fragments, don't queue 842 * any of them. 843 */ 844 if (ifp != NULL) { 845 s = splnet(); 846 if (ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len < fragments && 847 error == 0) { 848 error = ENOBUFS; 849 IP_STATINC(IP_STAT_ODROPPED); 850 IFQ_INC_DROPS(&ifp->if_snd); 851 } 852 splx(s); 853 } 854 if (error) { 855 for (m = m0; m; m = m0) { 856 m0 = m->m_nextpkt; 857 m->m_nextpkt = NULL; 858 m_freem(m); 859 } 860 } 861 return (error); 862 } 863 864 /* 865 * Process a delayed payload checksum calculation. 866 */ 867 void 868 in_delayed_cksum(struct mbuf *m) 869 { 870 struct ip *ip; 871 u_int16_t csum, offset; 872 873 ip = mtod(m, struct ip *); 874 offset = ip->ip_hl << 2; 875 csum = in4_cksum(m, 0, offset, ntohs(ip->ip_len) - offset); 876 if (csum == 0 && (m->m_pkthdr.csum_flags & M_CSUM_UDPv4) != 0) 877 csum = 0xffff; 878 879 offset += M_CSUM_DATA_IPv4_OFFSET(m->m_pkthdr.csum_data); 880 881 if ((offset + sizeof(u_int16_t)) > m->m_len) { 882 /* This happen when ip options were inserted 883 printf("in_delayed_cksum: pullup len %d off %d proto %d\n", 884 m->m_len, offset, ip->ip_p); 885 */ 886 m_copyback(m, offset, sizeof(csum), (void *) &csum); 887 } else 888 *(u_int16_t *)(mtod(m, char *) + offset) = csum; 889 } 890 891 /* 892 * Determine the maximum length of the options to be inserted; 893 * we would far rather allocate too much space rather than too little. 894 */ 895 896 u_int 897 ip_optlen(struct inpcb *inp) 898 { 899 struct mbuf *m = inp->inp_options; 900 901 if (m && m->m_len > offsetof(struct ipoption, ipopt_dst)) { 902 return (m->m_len - offsetof(struct ipoption, ipopt_dst)); 903 } 904 return 0; 905 } 906 907 /* 908 * Insert IP options into preformed packet. 909 * Adjust IP destination as required for IP source routing, 910 * as indicated by a non-zero in_addr at the start of the options. 911 */ 912 static struct mbuf * 913 ip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phlen) 914 { 915 struct ipoption *p = mtod(opt, struct ipoption *); 916 struct mbuf *n; 917 struct ip *ip = mtod(m, struct ip *); 918 unsigned optlen; 919 920 optlen = opt->m_len - sizeof(p->ipopt_dst); 921 if (optlen + ntohs(ip->ip_len) > IP_MAXPACKET) 922 return (m); /* XXX should fail */ 923 if (!in_nullhost(p->ipopt_dst)) 924 ip->ip_dst = p->ipopt_dst; 925 if (M_READONLY(m) || M_LEADINGSPACE(m) < optlen) { 926 MGETHDR(n, M_DONTWAIT, MT_HEADER); 927 if (n == 0) 928 return (m); 929 MCLAIM(n, m->m_owner); 930 M_MOVE_PKTHDR(n, m); 931 m->m_len -= sizeof(struct ip); 932 m->m_data += sizeof(struct ip); 933 n->m_next = m; 934 m = n; 935 m->m_len = optlen + sizeof(struct ip); 936 m->m_data += max_linkhdr; 937 bcopy((void *)ip, mtod(m, void *), sizeof(struct ip)); 938 } else { 939 m->m_data -= optlen; 940 m->m_len += optlen; 941 memmove(mtod(m, void *), ip, sizeof(struct ip)); 942 } 943 m->m_pkthdr.len += optlen; 944 ip = mtod(m, struct ip *); 945 bcopy((void *)p->ipopt_list, (void *)(ip + 1), (unsigned)optlen); 946 *phlen = sizeof(struct ip) + optlen; 947 ip->ip_len = htons(ntohs(ip->ip_len) + optlen); 948 return (m); 949 } 950 951 /* 952 * Copy options from ip to jp, 953 * omitting those not copied during fragmentation. 954 */ 955 int 956 ip_optcopy(struct ip *ip, struct ip *jp) 957 { 958 u_char *cp, *dp; 959 int opt, optlen, cnt; 960 961 cp = (u_char *)(ip + 1); 962 dp = (u_char *)(jp + 1); 963 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 964 for (; cnt > 0; cnt -= optlen, cp += optlen) { 965 opt = cp[0]; 966 if (opt == IPOPT_EOL) 967 break; 968 if (opt == IPOPT_NOP) { 969 /* Preserve for IP mcast tunnel's LSRR alignment. */ 970 *dp++ = IPOPT_NOP; 971 optlen = 1; 972 continue; 973 } 974 975 KASSERT(cnt >= IPOPT_OLEN + sizeof(*cp)); 976 optlen = cp[IPOPT_OLEN]; 977 KASSERT(optlen >= IPOPT_OLEN + sizeof(*cp) && optlen < cnt); 978 979 /* Invalid lengths should have been caught by ip_dooptions. */ 980 if (optlen > cnt) 981 optlen = cnt; 982 if (IPOPT_COPIED(opt)) { 983 bcopy((void *)cp, (void *)dp, (unsigned)optlen); 984 dp += optlen; 985 } 986 } 987 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 988 *dp++ = IPOPT_EOL; 989 return (optlen); 990 } 991 992 /* 993 * IP socket option processing. 994 */ 995 int 996 ip_ctloutput(int op, struct socket *so, struct sockopt *sopt) 997 { 998 struct inpcb *inp = sotoinpcb(so); 999 struct ip *ip = &inp->inp_ip; 1000 int inpflags = inp->inp_flags; 1001 int optval = 0, error = 0; 1002 1003 if (sopt->sopt_level != IPPROTO_IP) { 1004 if (sopt->sopt_level == SOL_SOCKET && sopt->sopt_name == SO_NOHEADER) 1005 return 0; 1006 return ENOPROTOOPT; 1007 } 1008 1009 switch (op) { 1010 case PRCO_SETOPT: 1011 switch (sopt->sopt_name) { 1012 case IP_OPTIONS: 1013 #ifdef notyet 1014 case IP_RETOPTS: 1015 #endif 1016 error = ip_pcbopts(inp, sopt); 1017 break; 1018 1019 case IP_TOS: 1020 case IP_TTL: 1021 case IP_MINTTL: 1022 case IP_PKTINFO: 1023 case IP_RECVOPTS: 1024 case IP_RECVRETOPTS: 1025 case IP_RECVDSTADDR: 1026 case IP_RECVIF: 1027 case IP_RECVPKTINFO: 1028 case IP_RECVTTL: 1029 error = sockopt_getint(sopt, &optval); 1030 if (error) 1031 break; 1032 1033 switch (sopt->sopt_name) { 1034 case IP_TOS: 1035 ip->ip_tos = optval; 1036 break; 1037 1038 case IP_TTL: 1039 ip->ip_ttl = optval; 1040 break; 1041 1042 case IP_MINTTL: 1043 if (optval > 0 && optval <= MAXTTL) 1044 inp->inp_ip_minttl = optval; 1045 else 1046 error = EINVAL; 1047 break; 1048 #define OPTSET(bit) \ 1049 if (optval) \ 1050 inpflags |= bit; \ 1051 else \ 1052 inpflags &= ~bit; 1053 1054 case IP_PKTINFO: 1055 OPTSET(INP_PKTINFO); 1056 break; 1057 1058 case IP_RECVOPTS: 1059 OPTSET(INP_RECVOPTS); 1060 break; 1061 1062 case IP_RECVPKTINFO: 1063 OPTSET(INP_RECVPKTINFO); 1064 break; 1065 1066 case IP_RECVRETOPTS: 1067 OPTSET(INP_RECVRETOPTS); 1068 break; 1069 1070 case IP_RECVDSTADDR: 1071 OPTSET(INP_RECVDSTADDR); 1072 break; 1073 1074 case IP_RECVIF: 1075 OPTSET(INP_RECVIF); 1076 break; 1077 1078 case IP_RECVTTL: 1079 OPTSET(INP_RECVTTL); 1080 break; 1081 } 1082 break; 1083 #undef OPTSET 1084 1085 case IP_MULTICAST_IF: 1086 case IP_MULTICAST_TTL: 1087 case IP_MULTICAST_LOOP: 1088 case IP_ADD_MEMBERSHIP: 1089 case IP_DROP_MEMBERSHIP: 1090 error = ip_setmoptions(&inp->inp_moptions, sopt); 1091 break; 1092 1093 case IP_PORTRANGE: 1094 error = sockopt_getint(sopt, &optval); 1095 if (error) 1096 break; 1097 1098 switch (optval) { 1099 case IP_PORTRANGE_DEFAULT: 1100 case IP_PORTRANGE_HIGH: 1101 inpflags &= ~(INP_LOWPORT); 1102 break; 1103 1104 case IP_PORTRANGE_LOW: 1105 inpflags |= INP_LOWPORT; 1106 break; 1107 1108 default: 1109 error = EINVAL; 1110 break; 1111 } 1112 break; 1113 1114 case IP_PORTALGO: 1115 error = sockopt_getint(sopt, &optval); 1116 if (error) 1117 break; 1118 1119 error = portalgo_algo_index_select( 1120 (struct inpcb_hdr *)inp, optval); 1121 break; 1122 1123 #if defined(IPSEC) 1124 case IP_IPSEC_POLICY: 1125 if (ipsec_enabled) { 1126 error = ipsec4_set_policy(inp, sopt->sopt_name, 1127 sopt->sopt_data, sopt->sopt_size, 1128 curlwp->l_cred); 1129 break; 1130 } 1131 /*FALLTHROUGH*/ 1132 #endif /* IPSEC */ 1133 1134 default: 1135 error = ENOPROTOOPT; 1136 break; 1137 } 1138 break; 1139 1140 case PRCO_GETOPT: 1141 switch (sopt->sopt_name) { 1142 case IP_OPTIONS: 1143 case IP_RETOPTS: { 1144 struct mbuf *mopts = inp->inp_options; 1145 1146 if (mopts) { 1147 struct mbuf *m; 1148 1149 m = m_copym(mopts, 0, M_COPYALL, M_DONTWAIT); 1150 if (m == NULL) { 1151 error = ENOBUFS; 1152 break; 1153 } 1154 error = sockopt_setmbuf(sopt, m); 1155 } 1156 break; 1157 } 1158 case IP_PKTINFO: 1159 case IP_TOS: 1160 case IP_TTL: 1161 case IP_MINTTL: 1162 case IP_RECVOPTS: 1163 case IP_RECVRETOPTS: 1164 case IP_RECVDSTADDR: 1165 case IP_RECVIF: 1166 case IP_RECVPKTINFO: 1167 case IP_RECVTTL: 1168 case IP_ERRORMTU: 1169 switch (sopt->sopt_name) { 1170 case IP_TOS: 1171 optval = ip->ip_tos; 1172 break; 1173 1174 case IP_TTL: 1175 optval = ip->ip_ttl; 1176 break; 1177 1178 case IP_MINTTL: 1179 optval = inp->inp_ip_minttl; 1180 break; 1181 1182 case IP_ERRORMTU: 1183 optval = inp->inp_errormtu; 1184 break; 1185 1186 #define OPTBIT(bit) (inpflags & bit ? 1 : 0) 1187 1188 case IP_PKTINFO: 1189 optval = OPTBIT(INP_PKTINFO); 1190 break; 1191 1192 case IP_RECVOPTS: 1193 optval = OPTBIT(INP_RECVOPTS); 1194 break; 1195 1196 case IP_RECVPKTINFO: 1197 optval = OPTBIT(INP_RECVPKTINFO); 1198 break; 1199 1200 case IP_RECVRETOPTS: 1201 optval = OPTBIT(INP_RECVRETOPTS); 1202 break; 1203 1204 case IP_RECVDSTADDR: 1205 optval = OPTBIT(INP_RECVDSTADDR); 1206 break; 1207 1208 case IP_RECVIF: 1209 optval = OPTBIT(INP_RECVIF); 1210 break; 1211 1212 case IP_RECVTTL: 1213 optval = OPTBIT(INP_RECVTTL); 1214 break; 1215 } 1216 error = sockopt_setint(sopt, optval); 1217 break; 1218 1219 #if 0 /* defined(IPSEC) */ 1220 case IP_IPSEC_POLICY: 1221 { 1222 struct mbuf *m = NULL; 1223 1224 /* XXX this will return EINVAL as sopt is empty */ 1225 error = ipsec4_get_policy(inp, sopt->sopt_data, 1226 sopt->sopt_size, &m); 1227 if (error == 0) 1228 error = sockopt_setmbuf(sopt, m); 1229 break; 1230 } 1231 #endif /*IPSEC*/ 1232 1233 case IP_MULTICAST_IF: 1234 case IP_MULTICAST_TTL: 1235 case IP_MULTICAST_LOOP: 1236 case IP_ADD_MEMBERSHIP: 1237 case IP_DROP_MEMBERSHIP: 1238 error = ip_getmoptions(inp->inp_moptions, sopt); 1239 break; 1240 1241 case IP_PORTRANGE: 1242 if (inpflags & INP_LOWPORT) 1243 optval = IP_PORTRANGE_LOW; 1244 else 1245 optval = IP_PORTRANGE_DEFAULT; 1246 error = sockopt_setint(sopt, optval); 1247 break; 1248 1249 case IP_PORTALGO: 1250 optval = inp->inp_portalgo; 1251 error = sockopt_setint(sopt, optval); 1252 break; 1253 1254 default: 1255 error = ENOPROTOOPT; 1256 break; 1257 } 1258 break; 1259 } 1260 1261 if (!error) { 1262 inp->inp_flags = inpflags; 1263 } 1264 return error; 1265 } 1266 1267 /* 1268 * Set up IP options in pcb for insertion in output packets. 1269 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1270 * with destination address if source routed. 1271 */ 1272 static int 1273 ip_pcbopts(struct inpcb *inp, const struct sockopt *sopt) 1274 { 1275 struct mbuf *m; 1276 const u_char *cp; 1277 u_char *dp; 1278 int cnt; 1279 1280 /* Turn off any old options. */ 1281 if (inp->inp_options) { 1282 m_free(inp->inp_options); 1283 } 1284 inp->inp_options = NULL; 1285 if ((cnt = sopt->sopt_size) == 0) { 1286 /* Only turning off any previous options. */ 1287 return 0; 1288 } 1289 cp = sopt->sopt_data; 1290 1291 #ifndef __vax__ 1292 if (cnt % sizeof(int32_t)) 1293 return (EINVAL); 1294 #endif 1295 1296 m = m_get(M_DONTWAIT, MT_SOOPTS); 1297 if (m == NULL) 1298 return (ENOBUFS); 1299 1300 dp = mtod(m, u_char *); 1301 memset(dp, 0, sizeof(struct in_addr)); 1302 dp += sizeof(struct in_addr); 1303 m->m_len = sizeof(struct in_addr); 1304 1305 /* 1306 * IP option list according to RFC791. Each option is of the form 1307 * 1308 * [optval] [olen] [(olen - 2) data bytes] 1309 * 1310 * We validate the list and copy options to an mbuf for prepending 1311 * to data packets. The IP first-hop destination address will be 1312 * stored before actual options and is zero if unset. 1313 */ 1314 while (cnt > 0) { 1315 uint8_t optval, olen, offset; 1316 1317 optval = cp[IPOPT_OPTVAL]; 1318 1319 if (optval == IPOPT_EOL || optval == IPOPT_NOP) { 1320 olen = 1; 1321 } else { 1322 if (cnt < IPOPT_OLEN + 1) 1323 goto bad; 1324 1325 olen = cp[IPOPT_OLEN]; 1326 if (olen < IPOPT_OLEN + 1 || olen > cnt) 1327 goto bad; 1328 } 1329 1330 if (optval == IPOPT_LSRR || optval == IPOPT_SSRR) { 1331 /* 1332 * user process specifies route as: 1333 * ->A->B->C->D 1334 * D must be our final destination (but we can't 1335 * check that since we may not have connected yet). 1336 * A is first hop destination, which doesn't appear in 1337 * actual IP option, but is stored before the options. 1338 */ 1339 if (olen < IPOPT_OFFSET + 1 + sizeof(struct in_addr)) 1340 goto bad; 1341 1342 offset = cp[IPOPT_OFFSET]; 1343 memcpy(mtod(m, u_char *), cp + IPOPT_OFFSET + 1, 1344 sizeof(struct in_addr)); 1345 1346 cp += sizeof(struct in_addr); 1347 cnt -= sizeof(struct in_addr); 1348 olen -= sizeof(struct in_addr); 1349 1350 if (m->m_len + olen > MAX_IPOPTLEN + sizeof(struct in_addr)) 1351 goto bad; 1352 1353 memcpy(dp, cp, olen); 1354 dp[IPOPT_OPTVAL] = optval; 1355 dp[IPOPT_OLEN] = olen; 1356 dp[IPOPT_OFFSET] = offset; 1357 break; 1358 } else { 1359 if (m->m_len + olen > MAX_IPOPTLEN + sizeof(struct in_addr)) 1360 goto bad; 1361 1362 memcpy(dp, cp, olen); 1363 break; 1364 } 1365 1366 dp += olen; 1367 m->m_len += olen; 1368 1369 if (optval == IPOPT_EOL) 1370 break; 1371 1372 cp += olen; 1373 cnt -= olen; 1374 } 1375 1376 inp->inp_options = m; 1377 return 0; 1378 bad: 1379 (void)m_free(m); 1380 return EINVAL; 1381 } 1382 1383 /* 1384 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1385 */ 1386 static struct ifnet * 1387 ip_multicast_if(struct in_addr *a, int *ifindexp) 1388 { 1389 int ifindex; 1390 struct ifnet *ifp = NULL; 1391 struct in_ifaddr *ia; 1392 1393 if (ifindexp) 1394 *ifindexp = 0; 1395 if (ntohl(a->s_addr) >> 24 == 0) { 1396 ifindex = ntohl(a->s_addr) & 0xffffff; 1397 ifp = if_byindex(ifindex); 1398 if (!ifp) 1399 return NULL; 1400 if (ifindexp) 1401 *ifindexp = ifindex; 1402 } else { 1403 LIST_FOREACH(ia, &IN_IFADDR_HASH(a->s_addr), ia_hash) { 1404 if (in_hosteq(ia->ia_addr.sin_addr, *a) && 1405 (ia->ia_ifp->if_flags & IFF_MULTICAST) != 0) { 1406 ifp = ia->ia_ifp; 1407 break; 1408 } 1409 } 1410 } 1411 return ifp; 1412 } 1413 1414 static int 1415 ip_getoptval(const struct sockopt *sopt, u_int8_t *val, u_int maxval) 1416 { 1417 u_int tval; 1418 u_char cval; 1419 int error; 1420 1421 if (sopt == NULL) 1422 return EINVAL; 1423 1424 switch (sopt->sopt_size) { 1425 case sizeof(u_char): 1426 error = sockopt_get(sopt, &cval, sizeof(u_char)); 1427 tval = cval; 1428 break; 1429 1430 case sizeof(u_int): 1431 error = sockopt_get(sopt, &tval, sizeof(u_int)); 1432 break; 1433 1434 default: 1435 error = EINVAL; 1436 } 1437 1438 if (error) 1439 return error; 1440 1441 if (tval > maxval) 1442 return EINVAL; 1443 1444 *val = tval; 1445 return 0; 1446 } 1447 1448 static int 1449 ip_get_membership(const struct sockopt *sopt, struct ifnet **ifp, 1450 struct in_addr *ia, bool add) 1451 { 1452 int error; 1453 struct ip_mreq mreq; 1454 1455 error = sockopt_get(sopt, &mreq, sizeof(mreq)); 1456 if (error) 1457 return error; 1458 1459 if (!IN_MULTICAST(mreq.imr_multiaddr.s_addr)) 1460 return EINVAL; 1461 1462 memcpy(ia, &mreq.imr_multiaddr, sizeof(*ia)); 1463 1464 if (in_nullhost(mreq.imr_interface)) { 1465 union { 1466 struct sockaddr dst; 1467 struct sockaddr_in dst4; 1468 } u; 1469 struct route ro; 1470 1471 if (!add) { 1472 *ifp = NULL; 1473 return 0; 1474 } 1475 /* 1476 * If no interface address was provided, use the interface of 1477 * the route to the given multicast address. 1478 */ 1479 struct rtentry *rt; 1480 memset(&ro, 0, sizeof(ro)); 1481 1482 sockaddr_in_init(&u.dst4, ia, 0); 1483 error = rtcache_setdst(&ro, &u.dst); 1484 if (error != 0) 1485 return error; 1486 *ifp = (rt = rtcache_init(&ro)) != NULL ? rt->rt_ifp : NULL; 1487 rtcache_free(&ro); 1488 } else { 1489 *ifp = ip_multicast_if(&mreq.imr_interface, NULL); 1490 if (!add && *ifp == NULL) 1491 return EADDRNOTAVAIL; 1492 } 1493 return 0; 1494 } 1495 1496 /* 1497 * Add a multicast group membership. 1498 * Group must be a valid IP multicast address. 1499 */ 1500 static int 1501 ip_add_membership(struct ip_moptions *imo, const struct sockopt *sopt) 1502 { 1503 struct ifnet *ifp = NULL; // XXX: gcc [ppc] 1504 struct in_addr ia; 1505 int i, error; 1506 1507 if (sopt->sopt_size == sizeof(struct ip_mreq)) 1508 error = ip_get_membership(sopt, &ifp, &ia, true); 1509 else 1510 #ifdef INET6 1511 error = ip6_get_membership(sopt, &ifp, &ia, sizeof(ia)); 1512 #else 1513 return EINVAL; 1514 #endif 1515 1516 if (error) 1517 return error; 1518 1519 /* 1520 * See if we found an interface, and confirm that it 1521 * supports multicast. 1522 */ 1523 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) 1524 return EADDRNOTAVAIL; 1525 1526 /* 1527 * See if the membership already exists or if all the 1528 * membership slots are full. 1529 */ 1530 for (i = 0; i < imo->imo_num_memberships; ++i) { 1531 if (imo->imo_membership[i]->inm_ifp == ifp && 1532 in_hosteq(imo->imo_membership[i]->inm_addr, ia)) 1533 break; 1534 } 1535 if (i < imo->imo_num_memberships) 1536 return EADDRINUSE; 1537 1538 if (i == IP_MAX_MEMBERSHIPS) 1539 return ETOOMANYREFS; 1540 1541 /* 1542 * Everything looks good; add a new record to the multicast 1543 * address list for the given interface. 1544 */ 1545 if ((imo->imo_membership[i] = in_addmulti(&ia, ifp)) == NULL) 1546 return ENOBUFS; 1547 1548 ++imo->imo_num_memberships; 1549 return 0; 1550 } 1551 1552 /* 1553 * Drop a multicast group membership. 1554 * Group must be a valid IP multicast address. 1555 */ 1556 static int 1557 ip_drop_membership(struct ip_moptions *imo, const struct sockopt *sopt) 1558 { 1559 struct in_addr ia = { .s_addr = 0 }; // XXX: gcc [ppc] 1560 struct ifnet *ifp = NULL; // XXX: gcc [ppc] 1561 int i, error; 1562 1563 if (sopt->sopt_size == sizeof(struct ip_mreq)) 1564 error = ip_get_membership(sopt, &ifp, &ia, false); 1565 else 1566 #ifdef INET6 1567 error = ip6_get_membership(sopt, &ifp, &ia, sizeof(ia)); 1568 #else 1569 return EINVAL; 1570 #endif 1571 1572 if (error) 1573 return error; 1574 1575 /* 1576 * Find the membership in the membership array. 1577 */ 1578 for (i = 0; i < imo->imo_num_memberships; ++i) { 1579 if ((ifp == NULL || 1580 imo->imo_membership[i]->inm_ifp == ifp) && 1581 in_hosteq(imo->imo_membership[i]->inm_addr, ia)) 1582 break; 1583 } 1584 if (i == imo->imo_num_memberships) 1585 return EADDRNOTAVAIL; 1586 1587 /* 1588 * Give up the multicast address record to which the 1589 * membership points. 1590 */ 1591 in_delmulti(imo->imo_membership[i]); 1592 1593 /* 1594 * Remove the gap in the membership array. 1595 */ 1596 for (++i; i < imo->imo_num_memberships; ++i) 1597 imo->imo_membership[i-1] = imo->imo_membership[i]; 1598 --imo->imo_num_memberships; 1599 return 0; 1600 } 1601 1602 /* 1603 * Set the IP multicast options in response to user setsockopt(). 1604 */ 1605 int 1606 ip_setmoptions(struct ip_moptions **pimo, const struct sockopt *sopt) 1607 { 1608 struct ip_moptions *imo = *pimo; 1609 struct in_addr addr; 1610 struct ifnet *ifp; 1611 int ifindex, error = 0; 1612 1613 if (!imo) { 1614 /* 1615 * No multicast option buffer attached to the pcb; 1616 * allocate one and initialize to default values. 1617 */ 1618 imo = kmem_intr_alloc(sizeof(*imo), KM_NOSLEEP); 1619 if (imo == NULL) 1620 return ENOBUFS; 1621 1622 imo->imo_multicast_ifp = NULL; 1623 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1624 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1625 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1626 imo->imo_num_memberships = 0; 1627 *pimo = imo; 1628 } 1629 1630 switch (sopt->sopt_name) { 1631 case IP_MULTICAST_IF: 1632 /* 1633 * Select the interface for outgoing multicast packets. 1634 */ 1635 error = sockopt_get(sopt, &addr, sizeof(addr)); 1636 if (error) 1637 break; 1638 1639 /* 1640 * INADDR_ANY is used to remove a previous selection. 1641 * When no interface is selected, a default one is 1642 * chosen every time a multicast packet is sent. 1643 */ 1644 if (in_nullhost(addr)) { 1645 imo->imo_multicast_ifp = NULL; 1646 break; 1647 } 1648 /* 1649 * The selected interface is identified by its local 1650 * IP address. Find the interface and confirm that 1651 * it supports multicasting. 1652 */ 1653 ifp = ip_multicast_if(&addr, &ifindex); 1654 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1655 error = EADDRNOTAVAIL; 1656 break; 1657 } 1658 imo->imo_multicast_ifp = ifp; 1659 if (ifindex) 1660 imo->imo_multicast_addr = addr; 1661 else 1662 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1663 break; 1664 1665 case IP_MULTICAST_TTL: 1666 /* 1667 * Set the IP time-to-live for outgoing multicast packets. 1668 */ 1669 error = ip_getoptval(sopt, &imo->imo_multicast_ttl, MAXTTL); 1670 break; 1671 1672 case IP_MULTICAST_LOOP: 1673 /* 1674 * Set the loopback flag for outgoing multicast packets. 1675 * Must be zero or one. 1676 */ 1677 error = ip_getoptval(sopt, &imo->imo_multicast_loop, 1); 1678 break; 1679 1680 case IP_ADD_MEMBERSHIP: /* IPV6_JOIN_GROUP */ 1681 error = ip_add_membership(imo, sopt); 1682 break; 1683 1684 case IP_DROP_MEMBERSHIP: /* IPV6_LEAVE_GROUP */ 1685 error = ip_drop_membership(imo, sopt); 1686 break; 1687 1688 default: 1689 error = EOPNOTSUPP; 1690 break; 1691 } 1692 1693 /* 1694 * If all options have default values, no need to keep the mbuf. 1695 */ 1696 if (imo->imo_multicast_ifp == NULL && 1697 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 1698 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 1699 imo->imo_num_memberships == 0) { 1700 kmem_free(imo, sizeof(*imo)); 1701 *pimo = NULL; 1702 } 1703 1704 return error; 1705 } 1706 1707 /* 1708 * Return the IP multicast options in response to user getsockopt(). 1709 */ 1710 int 1711 ip_getmoptions(struct ip_moptions *imo, struct sockopt *sopt) 1712 { 1713 struct in_addr addr; 1714 struct in_ifaddr *ia; 1715 uint8_t optval; 1716 int error = 0; 1717 1718 switch (sopt->sopt_name) { 1719 case IP_MULTICAST_IF: 1720 if (imo == NULL || imo->imo_multicast_ifp == NULL) 1721 addr = zeroin_addr; 1722 else if (imo->imo_multicast_addr.s_addr) { 1723 /* return the value user has set */ 1724 addr = imo->imo_multicast_addr; 1725 } else { 1726 IFP_TO_IA(imo->imo_multicast_ifp, ia); 1727 addr = ia ? ia->ia_addr.sin_addr : zeroin_addr; 1728 } 1729 error = sockopt_set(sopt, &addr, sizeof(addr)); 1730 break; 1731 1732 case IP_MULTICAST_TTL: 1733 optval = imo ? imo->imo_multicast_ttl 1734 : IP_DEFAULT_MULTICAST_TTL; 1735 1736 error = sockopt_set(sopt, &optval, sizeof(optval)); 1737 break; 1738 1739 case IP_MULTICAST_LOOP: 1740 optval = imo ? imo->imo_multicast_loop 1741 : IP_DEFAULT_MULTICAST_LOOP; 1742 1743 error = sockopt_set(sopt, &optval, sizeof(optval)); 1744 break; 1745 1746 default: 1747 error = EOPNOTSUPP; 1748 } 1749 1750 return error; 1751 } 1752 1753 /* 1754 * Discard the IP multicast options. 1755 */ 1756 void 1757 ip_freemoptions(struct ip_moptions *imo) 1758 { 1759 int i; 1760 1761 if (imo != NULL) { 1762 for (i = 0; i < imo->imo_num_memberships; ++i) 1763 in_delmulti(imo->imo_membership[i]); 1764 kmem_free(imo, sizeof(*imo)); 1765 } 1766 } 1767 1768 /* 1769 * Routine called from ip_output() to loop back a copy of an IP multicast 1770 * packet to the input queue of a specified interface. Note that this 1771 * calls the output routine of the loopback "driver", but with an interface 1772 * pointer that might NOT be lo0ifp -- easier than replicating that code here. 1773 */ 1774 static void 1775 ip_mloopback(struct ifnet *ifp, struct mbuf *m, const struct sockaddr_in *dst) 1776 { 1777 struct ip *ip; 1778 struct mbuf *copym; 1779 1780 copym = m_copypacket(m, M_DONTWAIT); 1781 if (copym != NULL && 1782 (copym->m_flags & M_EXT || copym->m_len < sizeof(struct ip))) 1783 copym = m_pullup(copym, sizeof(struct ip)); 1784 if (copym == NULL) 1785 return; 1786 /* 1787 * We don't bother to fragment if the IP length is greater 1788 * than the interface's MTU. Can this possibly matter? 1789 */ 1790 ip = mtod(copym, struct ip *); 1791 1792 if (copym->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 1793 in_delayed_cksum(copym); 1794 copym->m_pkthdr.csum_flags &= 1795 ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 1796 } 1797 1798 ip->ip_sum = 0; 1799 ip->ip_sum = in_cksum(copym, ip->ip_hl << 2); 1800 #ifndef NET_MPSAFE 1801 KERNEL_LOCK(1, NULL); 1802 #endif 1803 (void)looutput(ifp, copym, sintocsa(dst), NULL); 1804 #ifndef NET_MPSAFE 1805 KERNEL_UNLOCK_ONE(NULL); 1806 #endif 1807 } 1808