1 /* $NetBSD: ip_output.c,v 1.248 2016/01/20 22:12:22 riastradh 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 1.248 2016/01/20 22:12:22 riastradh 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 bool 161 ip_hresolv_needed(const struct ifnet * const ifp) 162 { 163 switch (ifp->if_type) { 164 case IFT_ARCNET: 165 case IFT_ATM: 166 case IFT_ECONET: 167 case IFT_ETHER: 168 case IFT_FDDI: 169 case IFT_HIPPI: 170 case IFT_IEEE1394: 171 case IFT_ISO88025: 172 case IFT_SLIP: 173 return true; 174 default: 175 return false; 176 } 177 } 178 179 static int 180 klock_if_output(struct ifnet * const ifp, struct mbuf * const m, 181 const struct sockaddr * const dst, struct rtentry *rt) 182 { 183 int error; 184 185 #ifndef NET_MPSAFE 186 KERNEL_LOCK(1, NULL); 187 #endif 188 189 error = (*ifp->if_output)(ifp, m, dst, rt); 190 191 #ifndef NET_MPSAFE 192 KERNEL_UNLOCK_ONE(NULL); 193 #endif 194 195 return error; 196 } 197 198 /* 199 * Send an IP packet to a host. 200 * 201 * If necessary, resolve the arbitrary IP route, rt0, to an IP host route before 202 * calling ifp's output routine. 203 */ 204 int 205 ip_hresolv_output(struct ifnet * const ifp0, struct mbuf * const m, 206 const struct sockaddr * const dst, struct rtentry *rt00) 207 { 208 int error = 0; 209 struct ifnet *ifp = ifp0; 210 struct rtentry *rt, *rt0, *gwrt; 211 212 #define RTFREE_IF_NEEDED(_rt) \ 213 if ((_rt) != NULL && (_rt) != rt00) \ 214 rtfree((_rt)); 215 216 rt0 = rt00; 217 retry: 218 if (!ip_hresolv_needed(ifp)) { 219 rt = rt0; 220 goto out; 221 } 222 223 if (rt0 == NULL) { 224 rt = NULL; 225 goto out; 226 } 227 228 rt = rt0; 229 230 /* 231 * The following block is highly questionable. How did we get here 232 * with a !RTF_UP route? Does rtalloc1() always return an RTF_UP 233 * route? 234 */ 235 if ((rt->rt_flags & RTF_UP) == 0) { 236 rt = rtalloc1(dst, 1); 237 if (rt == NULL) { 238 error = EHOSTUNREACH; 239 goto bad; 240 } 241 rt0 = rt; 242 if (rt->rt_ifp != ifp) { 243 ifp = rt->rt_ifp; 244 goto retry; 245 } 246 } 247 248 if ((rt->rt_flags & RTF_GATEWAY) == 0) 249 goto out; 250 251 gwrt = rt_get_gwroute(rt); 252 RTFREE_IF_NEEDED(rt); 253 rt = gwrt; 254 if (rt == NULL || (rt->rt_flags & RTF_UP) == 0) { 255 if (rt != NULL) { 256 RTFREE_IF_NEEDED(rt); 257 rt = rt0; 258 } 259 if (rt == NULL) { 260 error = EHOSTUNREACH; 261 goto bad; 262 } 263 gwrt = rtalloc1(rt->rt_gateway, 1); 264 rt_set_gwroute(rt, gwrt); 265 RTFREE_IF_NEEDED(rt); 266 rt = gwrt; 267 if (rt == NULL) { 268 error = EHOSTUNREACH; 269 goto bad; 270 } 271 /* the "G" test below also prevents rt == rt0 */ 272 if ((rt->rt_flags & RTF_GATEWAY) != 0 || rt->rt_ifp != ifp) { 273 if (rt0->rt_gwroute != NULL) 274 rtfree(rt0->rt_gwroute); 275 rt0->rt_gwroute = NULL; 276 error = EHOSTUNREACH; 277 goto bad; 278 } 279 } 280 if ((rt->rt_flags & RTF_REJECT) != 0) { 281 if (rt->rt_rmx.rmx_expire == 0 || 282 time_uptime < rt->rt_rmx.rmx_expire) { 283 error = (rt == rt0) ? EHOSTDOWN : EHOSTUNREACH; 284 goto bad; 285 } 286 } 287 288 out: 289 #ifdef MPLS 290 if (rt0 != NULL && rt_gettag(rt0) != NULL && 291 rt_gettag(rt0)->sa_family == AF_MPLS && 292 (m->m_flags & (M_MCAST | M_BCAST)) == 0 && 293 ifp->if_type == IFT_ETHER) { 294 union mpls_shim msh; 295 msh.s_addr = MPLS_GETSADDR(rt0); 296 if (msh.shim.label != MPLS_LABEL_IMPLNULL) { 297 struct m_tag *mtag; 298 /* 299 * XXX tentative solution to tell ether_output 300 * it's MPLS. Need some more efficient solution. 301 */ 302 mtag = m_tag_get(PACKET_TAG_MPLS, 303 sizeof(int) /* dummy */, 304 M_NOWAIT); 305 if (mtag == NULL) { 306 error = ENOMEM; 307 goto bad; 308 } 309 m_tag_prepend(m, mtag); 310 } 311 } 312 #endif 313 314 error = klock_if_output(ifp, m, dst, rt); 315 goto exit; 316 317 bad: 318 if (m != NULL) 319 m_freem(m); 320 exit: 321 RTFREE_IF_NEEDED(rt); 322 323 return error; 324 325 #undef RTFREE_IF_NEEDED 326 } 327 328 /* 329 * IP output. The packet in mbuf chain m contains a skeletal IP 330 * header (with len, off, ttl, proto, tos, src, dst). 331 * The mbuf chain containing the packet will be freed. 332 * The mbuf opt, if present, will not be freed. 333 */ 334 int 335 ip_output(struct mbuf *m0, struct mbuf *opt, struct route *ro, int flags, 336 struct ip_moptions *imo, struct socket *so) 337 { 338 struct rtentry *rt; 339 struct ip *ip; 340 struct ifnet *ifp; 341 struct mbuf *m = m0; 342 int hlen = sizeof (struct ip); 343 int len, error = 0; 344 struct route iproute; 345 const struct sockaddr_in *dst; 346 struct in_ifaddr *ia; 347 int isbroadcast; 348 int sw_csum; 349 u_long mtu; 350 #ifdef IPSEC 351 struct secpolicy *sp = NULL; 352 #endif 353 bool natt_frag = false; 354 bool rtmtu_nolock; 355 union { 356 struct sockaddr dst; 357 struct sockaddr_in dst4; 358 } u; 359 struct sockaddr *rdst = &u.dst; /* real IP destination, as opposed 360 * to the nexthop 361 */ 362 363 len = 0; 364 365 MCLAIM(m, &ip_tx_mowner); 366 367 KASSERT((m->m_flags & M_PKTHDR) != 0); 368 KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_TCPv6|M_CSUM_UDPv6)) == 0); 369 KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) != 370 (M_CSUM_TCPv4|M_CSUM_UDPv4)); 371 372 if (opt) { 373 m = ip_insertoptions(m, opt, &len); 374 if (len >= sizeof(struct ip)) 375 hlen = len; 376 } 377 ip = mtod(m, struct ip *); 378 379 /* 380 * Fill in IP header. 381 */ 382 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 383 ip->ip_v = IPVERSION; 384 ip->ip_off = htons(0); 385 /* ip->ip_id filled in after we find out source ia */ 386 ip->ip_hl = hlen >> 2; 387 IP_STATINC(IP_STAT_LOCALOUT); 388 } else { 389 hlen = ip->ip_hl << 2; 390 } 391 392 /* 393 * Route packet. 394 */ 395 if (ro == NULL) { 396 memset(&iproute, 0, sizeof(iproute)); 397 ro = &iproute; 398 } 399 sockaddr_in_init(&u.dst4, &ip->ip_dst, 0); 400 dst = satocsin(rtcache_getdst(ro)); 401 402 /* 403 * If there is a cached route, check that it is to the same 404 * destination and is still up. If not, free it and try again. 405 * The address family should also be checked in case of sharing 406 * the cache with IPv6. 407 */ 408 if (dst && (dst->sin_family != AF_INET || 409 !in_hosteq(dst->sin_addr, ip->ip_dst))) 410 rtcache_free(ro); 411 412 if ((rt = rtcache_validate(ro)) == NULL && 413 (rt = rtcache_update(ro, 1)) == NULL) { 414 dst = &u.dst4; 415 error = rtcache_setdst(ro, &u.dst); 416 if (error != 0) 417 goto bad; 418 } 419 420 /* 421 * If routing to interface only, short circuit routing lookup. 422 */ 423 if (flags & IP_ROUTETOIF) { 424 if ((ia = ifatoia(ifa_ifwithladdr(sintocsa(dst)))) == NULL) { 425 IP_STATINC(IP_STAT_NOROUTE); 426 error = ENETUNREACH; 427 goto bad; 428 } 429 ifp = ia->ia_ifp; 430 mtu = ifp->if_mtu; 431 ip->ip_ttl = 1; 432 isbroadcast = in_broadcast(dst->sin_addr, ifp); 433 } else if ((IN_MULTICAST(ip->ip_dst.s_addr) || 434 ip->ip_dst.s_addr == INADDR_BROADCAST) && 435 imo != NULL && imo->imo_multicast_ifp != NULL) { 436 ifp = imo->imo_multicast_ifp; 437 mtu = ifp->if_mtu; 438 IFP_TO_IA(ifp, ia); 439 isbroadcast = 0; 440 } else { 441 if (rt == NULL) 442 rt = rtcache_init(ro); 443 if (rt == NULL) { 444 IP_STATINC(IP_STAT_NOROUTE); 445 error = EHOSTUNREACH; 446 goto bad; 447 } 448 ia = ifatoia(rt->rt_ifa); 449 ifp = rt->rt_ifp; 450 if ((mtu = rt->rt_rmx.rmx_mtu) == 0) 451 mtu = ifp->if_mtu; 452 rt->rt_use++; 453 if (rt->rt_flags & RTF_GATEWAY) 454 dst = satosin(rt->rt_gateway); 455 if (rt->rt_flags & RTF_HOST) 456 isbroadcast = rt->rt_flags & RTF_BROADCAST; 457 else 458 isbroadcast = in_broadcast(dst->sin_addr, ifp); 459 } 460 rtmtu_nolock = rt && (rt->rt_rmx.rmx_locks & RTV_MTU) == 0; 461 462 if (IN_MULTICAST(ip->ip_dst.s_addr) || 463 (ip->ip_dst.s_addr == INADDR_BROADCAST)) { 464 bool inmgroup; 465 466 m->m_flags |= (ip->ip_dst.s_addr == INADDR_BROADCAST) ? 467 M_BCAST : M_MCAST; 468 /* 469 * See if the caller provided any multicast options 470 */ 471 if (imo != NULL) 472 ip->ip_ttl = imo->imo_multicast_ttl; 473 else 474 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 475 476 /* 477 * if we don't know the outgoing ifp yet, we can't generate 478 * output 479 */ 480 if (!ifp) { 481 IP_STATINC(IP_STAT_NOROUTE); 482 error = ENETUNREACH; 483 goto bad; 484 } 485 486 /* 487 * If the packet is multicast or broadcast, confirm that 488 * the outgoing interface can transmit it. 489 */ 490 if (((m->m_flags & M_MCAST) && 491 (ifp->if_flags & IFF_MULTICAST) == 0) || 492 ((m->m_flags & M_BCAST) && 493 (ifp->if_flags & (IFF_BROADCAST|IFF_POINTOPOINT)) == 0)) { 494 IP_STATINC(IP_STAT_NOROUTE); 495 error = ENETUNREACH; 496 goto bad; 497 } 498 /* 499 * If source address not specified yet, use an address 500 * of outgoing interface. 501 */ 502 if (in_nullhost(ip->ip_src)) { 503 struct in_ifaddr *xia; 504 struct ifaddr *xifa; 505 506 IFP_TO_IA(ifp, xia); 507 if (!xia) { 508 error = EADDRNOTAVAIL; 509 goto bad; 510 } 511 xifa = &xia->ia_ifa; 512 if (xifa->ifa_getifa != NULL) { 513 xia = ifatoia((*xifa->ifa_getifa)(xifa, rdst)); 514 if (xia == NULL) { 515 error = EADDRNOTAVAIL; 516 goto bad; 517 } 518 } 519 ip->ip_src = xia->ia_addr.sin_addr; 520 } 521 522 inmgroup = in_multi_group(ip->ip_dst, ifp, flags); 523 if (inmgroup && (imo == NULL || imo->imo_multicast_loop)) { 524 /* 525 * If we belong to the destination multicast group 526 * on the outgoing interface, and the caller did not 527 * forbid loopback, loop back a copy. 528 */ 529 ip_mloopback(ifp, m, &u.dst4); 530 } 531 #ifdef MROUTING 532 else { 533 /* 534 * If we are acting as a multicast router, perform 535 * multicast forwarding as if the packet had just 536 * arrived on the interface to which we are about 537 * to send. The multicast forwarding function 538 * recursively calls this function, using the 539 * IP_FORWARDING flag to prevent infinite recursion. 540 * 541 * Multicasts that are looped back by ip_mloopback(), 542 * above, will be forwarded by the ip_input() routine, 543 * if necessary. 544 */ 545 extern struct socket *ip_mrouter; 546 547 if (ip_mrouter && (flags & IP_FORWARDING) == 0) { 548 if (ip_mforward(m, ifp) != 0) { 549 m_freem(m); 550 goto done; 551 } 552 } 553 } 554 #endif 555 /* 556 * Multicasts with a time-to-live of zero may be looped- 557 * back, above, but must not be transmitted on a network. 558 * Also, multicasts addressed to the loopback interface 559 * are not sent -- the above call to ip_mloopback() will 560 * loop back a copy if this host actually belongs to the 561 * destination group on the loopback interface. 562 */ 563 if (ip->ip_ttl == 0 || (ifp->if_flags & IFF_LOOPBACK) != 0) { 564 m_freem(m); 565 goto done; 566 } 567 goto sendit; 568 } 569 570 /* 571 * If source address not specified yet, use address 572 * of outgoing interface. 573 */ 574 if (in_nullhost(ip->ip_src)) { 575 struct ifaddr *xifa; 576 577 xifa = &ia->ia_ifa; 578 if (xifa->ifa_getifa != NULL) { 579 ia = ifatoia((*xifa->ifa_getifa)(xifa, rdst)); 580 if (ia == NULL) { 581 error = EADDRNOTAVAIL; 582 goto bad; 583 } 584 } 585 ip->ip_src = ia->ia_addr.sin_addr; 586 } 587 588 /* 589 * packets with Class-D address as source are not valid per 590 * RFC 1112 591 */ 592 if (IN_MULTICAST(ip->ip_src.s_addr)) { 593 IP_STATINC(IP_STAT_ODROPPED); 594 error = EADDRNOTAVAIL; 595 goto bad; 596 } 597 598 /* 599 * Look for broadcast address and and verify user is allowed to 600 * send such a packet. 601 */ 602 if (isbroadcast) { 603 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 604 error = EADDRNOTAVAIL; 605 goto bad; 606 } 607 if ((flags & IP_ALLOWBROADCAST) == 0) { 608 error = EACCES; 609 goto bad; 610 } 611 /* don't allow broadcast messages to be fragmented */ 612 if (ntohs(ip->ip_len) > ifp->if_mtu) { 613 error = EMSGSIZE; 614 goto bad; 615 } 616 m->m_flags |= M_BCAST; 617 } else 618 m->m_flags &= ~M_BCAST; 619 620 sendit: 621 if ((flags & (IP_FORWARDING|IP_NOIPNEWID)) == 0) { 622 if (m->m_pkthdr.len < IP_MINFRAGSIZE) { 623 ip->ip_id = 0; 624 } else if ((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) { 625 ip->ip_id = ip_newid(ia); 626 } else { 627 628 /* 629 * TSO capable interfaces (typically?) increment 630 * ip_id for each segment. 631 * "allocate" enough ids here to increase the chance 632 * for them to be unique. 633 * 634 * note that the following calculation is not 635 * needed to be precise. wasting some ip_id is fine. 636 */ 637 638 unsigned int segsz = m->m_pkthdr.segsz; 639 unsigned int datasz = ntohs(ip->ip_len) - hlen; 640 unsigned int num = howmany(datasz, segsz); 641 642 ip->ip_id = ip_newid_range(ia, num); 643 } 644 } 645 646 /* 647 * If we're doing Path MTU Discovery, we need to set DF unless 648 * the route's MTU is locked. 649 */ 650 if ((flags & IP_MTUDISC) != 0 && rtmtu_nolock) { 651 ip->ip_off |= htons(IP_DF); 652 } 653 654 #ifdef IPSEC 655 if (ipsec_used) { 656 bool ipsec_done = false; 657 658 /* Perform IPsec processing, if any. */ 659 error = ipsec4_output(m, so, flags, &sp, &mtu, &natt_frag, 660 &ipsec_done); 661 if (error || ipsec_done) 662 goto done; 663 } 664 #endif 665 666 /* 667 * Run through list of hooks for output packets. 668 */ 669 error = pfil_run_hooks(inet_pfil_hook, &m, ifp, PFIL_OUT); 670 if (error) 671 goto done; 672 if (m == NULL) 673 goto done; 674 675 ip = mtod(m, struct ip *); 676 hlen = ip->ip_hl << 2; 677 678 m->m_pkthdr.csum_data |= hlen << 16; 679 680 #if IFA_STATS 681 /* 682 * search for the source address structure to 683 * maintain output statistics. 684 */ 685 INADDR_TO_IA(ip->ip_src, ia); 686 #endif 687 688 /* Maybe skip checksums on loopback interfaces. */ 689 if (IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) { 690 m->m_pkthdr.csum_flags |= M_CSUM_IPv4; 691 } 692 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_csum_flags_tx; 693 /* 694 * If small enough for mtu of path, or if using TCP segmentation 695 * offload, can just send directly. 696 */ 697 if (ntohs(ip->ip_len) <= mtu || 698 (m->m_pkthdr.csum_flags & M_CSUM_TSOv4) != 0) { 699 const struct sockaddr *sa; 700 701 #if IFA_STATS 702 if (ia) 703 ia->ia_ifa.ifa_data.ifad_outbytes += ntohs(ip->ip_len); 704 #endif 705 /* 706 * Always initialize the sum to 0! Some HW assisted 707 * checksumming requires this. 708 */ 709 ip->ip_sum = 0; 710 711 if ((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) { 712 /* 713 * Perform any checksums that the hardware can't do 714 * for us. 715 * 716 * XXX Does any hardware require the {th,uh}_sum 717 * XXX fields to be 0? 718 */ 719 if (sw_csum & M_CSUM_IPv4) { 720 KASSERT(IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)); 721 ip->ip_sum = in_cksum(m, hlen); 722 m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4; 723 } 724 if (sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 725 if (IN_NEED_CHECKSUM(ifp, 726 sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4))) { 727 in_delayed_cksum(m); 728 } 729 m->m_pkthdr.csum_flags &= 730 ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 731 } 732 } 733 734 sa = (m->m_flags & M_MCAST) ? sintocsa(rdst) : sintocsa(dst); 735 if (__predict_true( 736 (m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0 || 737 (ifp->if_capenable & IFCAP_TSOv4) != 0)) { 738 error = ip_hresolv_output(ifp, m, sa, rt); 739 } else { 740 error = ip_tso_output(ifp, m, sa, rt); 741 } 742 goto done; 743 } 744 745 /* 746 * We can't use HW checksumming if we're about to 747 * to fragment the packet. 748 * 749 * XXX Some hardware can do this. 750 */ 751 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 752 if (IN_NEED_CHECKSUM(ifp, 753 m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4))) { 754 in_delayed_cksum(m); 755 } 756 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 757 } 758 759 /* 760 * Too large for interface; fragment if possible. 761 * Must be able to put at least 8 bytes per fragment. 762 */ 763 if (ntohs(ip->ip_off) & IP_DF) { 764 if (flags & IP_RETURNMTU) { 765 struct inpcb *inp; 766 767 KASSERT(so && solocked(so)); 768 inp = sotoinpcb(so); 769 inp->inp_errormtu = mtu; 770 } 771 error = EMSGSIZE; 772 IP_STATINC(IP_STAT_CANTFRAG); 773 goto bad; 774 } 775 776 error = ip_fragment(m, ifp, mtu); 777 if (error) { 778 m = NULL; 779 goto bad; 780 } 781 782 for (; m; m = m0) { 783 m0 = m->m_nextpkt; 784 m->m_nextpkt = 0; 785 if (error) { 786 m_freem(m); 787 continue; 788 } 789 #if IFA_STATS 790 if (ia) 791 ia->ia_ifa.ifa_data.ifad_outbytes += ntohs(ip->ip_len); 792 #endif 793 /* 794 * If we get there, the packet has not been handled by 795 * IPsec whereas it should have. Now that it has been 796 * fragmented, re-inject it in ip_output so that IPsec 797 * processing can occur. 798 */ 799 if (natt_frag) { 800 error = ip_output(m, opt, ro, 801 flags | IP_RAWOUTPUT | IP_NOIPNEWID, 802 imo, so); 803 } else { 804 KASSERT((m->m_pkthdr.csum_flags & 805 (M_CSUM_UDPv4 | M_CSUM_TCPv4)) == 0); 806 error = ip_hresolv_output(ifp, m, 807 (m->m_flags & M_MCAST) ? 808 sintocsa(rdst) : sintocsa(dst), rt); 809 } 810 } 811 if (error == 0) { 812 IP_STATINC(IP_STAT_FRAGMENTED); 813 } 814 done: 815 if (ro == &iproute) { 816 rtcache_free(&iproute); 817 } 818 #ifdef IPSEC 819 if (sp) { 820 KEY_FREESP(&sp); 821 } 822 #endif 823 return error; 824 bad: 825 m_freem(m); 826 goto done; 827 } 828 829 int 830 ip_fragment(struct mbuf *m, struct ifnet *ifp, u_long mtu) 831 { 832 struct ip *ip, *mhip; 833 struct mbuf *m0; 834 int len, hlen, off; 835 int mhlen, firstlen; 836 struct mbuf **mnext; 837 int sw_csum = m->m_pkthdr.csum_flags; 838 int fragments = 0; 839 int s; 840 int error = 0; 841 842 ip = mtod(m, struct ip *); 843 hlen = ip->ip_hl << 2; 844 if (ifp != NULL) 845 sw_csum &= ~ifp->if_csum_flags_tx; 846 847 len = (mtu - hlen) &~ 7; 848 if (len < 8) { 849 m_freem(m); 850 return (EMSGSIZE); 851 } 852 853 firstlen = len; 854 mnext = &m->m_nextpkt; 855 856 /* 857 * Loop through length of segment after first fragment, 858 * make new header and copy data of each part and link onto chain. 859 */ 860 m0 = m; 861 mhlen = sizeof (struct ip); 862 for (off = hlen + len; off < ntohs(ip->ip_len); off += len) { 863 MGETHDR(m, M_DONTWAIT, MT_HEADER); 864 if (m == 0) { 865 error = ENOBUFS; 866 IP_STATINC(IP_STAT_ODROPPED); 867 goto sendorfree; 868 } 869 MCLAIM(m, m0->m_owner); 870 *mnext = m; 871 mnext = &m->m_nextpkt; 872 m->m_data += max_linkhdr; 873 mhip = mtod(m, struct ip *); 874 *mhip = *ip; 875 /* we must inherit MCAST and BCAST flags */ 876 m->m_flags |= m0->m_flags & (M_MCAST|M_BCAST); 877 if (hlen > sizeof (struct ip)) { 878 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 879 mhip->ip_hl = mhlen >> 2; 880 } 881 m->m_len = mhlen; 882 mhip->ip_off = ((off - hlen) >> 3) + 883 (ntohs(ip->ip_off) & ~IP_MF); 884 if (ip->ip_off & htons(IP_MF)) 885 mhip->ip_off |= IP_MF; 886 if (off + len >= ntohs(ip->ip_len)) 887 len = ntohs(ip->ip_len) - off; 888 else 889 mhip->ip_off |= IP_MF; 890 HTONS(mhip->ip_off); 891 mhip->ip_len = htons((u_int16_t)(len + mhlen)); 892 m->m_next = m_copym(m0, off, len, M_DONTWAIT); 893 if (m->m_next == 0) { 894 error = ENOBUFS; /* ??? */ 895 IP_STATINC(IP_STAT_ODROPPED); 896 goto sendorfree; 897 } 898 m->m_pkthdr.len = mhlen + len; 899 m->m_pkthdr.rcvif = NULL; 900 mhip->ip_sum = 0; 901 KASSERT((m->m_pkthdr.csum_flags & M_CSUM_IPv4) == 0); 902 if (sw_csum & M_CSUM_IPv4) { 903 mhip->ip_sum = in_cksum(m, mhlen); 904 } else { 905 /* 906 * checksum is hw-offloaded or not necessary. 907 */ 908 m->m_pkthdr.csum_flags |= 909 m0->m_pkthdr.csum_flags & M_CSUM_IPv4; 910 m->m_pkthdr.csum_data |= mhlen << 16; 911 KASSERT(!(ifp != NULL && 912 IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) || 913 (m->m_pkthdr.csum_flags & M_CSUM_IPv4) != 0); 914 } 915 IP_STATINC(IP_STAT_OFRAGMENTS); 916 fragments++; 917 } 918 /* 919 * Update first fragment by trimming what's been copied out 920 * and updating header, then send each fragment (in order). 921 */ 922 m = m0; 923 m_adj(m, hlen + firstlen - ntohs(ip->ip_len)); 924 m->m_pkthdr.len = hlen + firstlen; 925 ip->ip_len = htons((u_int16_t)m->m_pkthdr.len); 926 ip->ip_off |= htons(IP_MF); 927 ip->ip_sum = 0; 928 if (sw_csum & M_CSUM_IPv4) { 929 ip->ip_sum = in_cksum(m, hlen); 930 m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4; 931 } else { 932 /* 933 * checksum is hw-offloaded or not necessary. 934 */ 935 KASSERT(!(ifp != NULL && IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) || 936 (m->m_pkthdr.csum_flags & M_CSUM_IPv4) != 0); 937 KASSERT(M_CSUM_DATA_IPv4_IPHL(m->m_pkthdr.csum_data) >= 938 sizeof(struct ip)); 939 } 940 sendorfree: 941 /* 942 * If there is no room for all the fragments, don't queue 943 * any of them. 944 */ 945 if (ifp != NULL) { 946 s = splnet(); 947 if (ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len < fragments && 948 error == 0) { 949 error = ENOBUFS; 950 IP_STATINC(IP_STAT_ODROPPED); 951 IFQ_INC_DROPS(&ifp->if_snd); 952 } 953 splx(s); 954 } 955 if (error) { 956 for (m = m0; m; m = m0) { 957 m0 = m->m_nextpkt; 958 m->m_nextpkt = NULL; 959 m_freem(m); 960 } 961 } 962 return (error); 963 } 964 965 /* 966 * Process a delayed payload checksum calculation. 967 */ 968 void 969 in_delayed_cksum(struct mbuf *m) 970 { 971 struct ip *ip; 972 u_int16_t csum, offset; 973 974 ip = mtod(m, struct ip *); 975 offset = ip->ip_hl << 2; 976 csum = in4_cksum(m, 0, offset, ntohs(ip->ip_len) - offset); 977 if (csum == 0 && (m->m_pkthdr.csum_flags & M_CSUM_UDPv4) != 0) 978 csum = 0xffff; 979 980 offset += M_CSUM_DATA_IPv4_OFFSET(m->m_pkthdr.csum_data); 981 982 if ((offset + sizeof(u_int16_t)) > m->m_len) { 983 /* This happen when ip options were inserted 984 printf("in_delayed_cksum: pullup len %d off %d proto %d\n", 985 m->m_len, offset, ip->ip_p); 986 */ 987 m_copyback(m, offset, sizeof(csum), (void *) &csum); 988 } else 989 *(u_int16_t *)(mtod(m, char *) + offset) = csum; 990 } 991 992 /* 993 * Determine the maximum length of the options to be inserted; 994 * we would far rather allocate too much space rather than too little. 995 */ 996 997 u_int 998 ip_optlen(struct inpcb *inp) 999 { 1000 struct mbuf *m = inp->inp_options; 1001 1002 if (m && m->m_len > offsetof(struct ipoption, ipopt_dst)) { 1003 return (m->m_len - offsetof(struct ipoption, ipopt_dst)); 1004 } 1005 return 0; 1006 } 1007 1008 /* 1009 * Insert IP options into preformed packet. 1010 * Adjust IP destination as required for IP source routing, 1011 * as indicated by a non-zero in_addr at the start of the options. 1012 */ 1013 static struct mbuf * 1014 ip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phlen) 1015 { 1016 struct ipoption *p = mtod(opt, struct ipoption *); 1017 struct mbuf *n; 1018 struct ip *ip = mtod(m, struct ip *); 1019 unsigned optlen; 1020 1021 optlen = opt->m_len - sizeof(p->ipopt_dst); 1022 if (optlen + ntohs(ip->ip_len) > IP_MAXPACKET) 1023 return (m); /* XXX should fail */ 1024 if (!in_nullhost(p->ipopt_dst)) 1025 ip->ip_dst = p->ipopt_dst; 1026 if (M_READONLY(m) || M_LEADINGSPACE(m) < optlen) { 1027 MGETHDR(n, M_DONTWAIT, MT_HEADER); 1028 if (n == 0) 1029 return (m); 1030 MCLAIM(n, m->m_owner); 1031 M_MOVE_PKTHDR(n, m); 1032 m->m_len -= sizeof(struct ip); 1033 m->m_data += sizeof(struct ip); 1034 n->m_next = m; 1035 m = n; 1036 m->m_len = optlen + sizeof(struct ip); 1037 m->m_data += max_linkhdr; 1038 bcopy((void *)ip, mtod(m, void *), sizeof(struct ip)); 1039 } else { 1040 m->m_data -= optlen; 1041 m->m_len += optlen; 1042 memmove(mtod(m, void *), ip, sizeof(struct ip)); 1043 } 1044 m->m_pkthdr.len += optlen; 1045 ip = mtod(m, struct ip *); 1046 bcopy((void *)p->ipopt_list, (void *)(ip + 1), (unsigned)optlen); 1047 *phlen = sizeof(struct ip) + optlen; 1048 ip->ip_len = htons(ntohs(ip->ip_len) + optlen); 1049 return (m); 1050 } 1051 1052 /* 1053 * Copy options from ip to jp, 1054 * omitting those not copied during fragmentation. 1055 */ 1056 int 1057 ip_optcopy(struct ip *ip, struct ip *jp) 1058 { 1059 u_char *cp, *dp; 1060 int opt, optlen, cnt; 1061 1062 cp = (u_char *)(ip + 1); 1063 dp = (u_char *)(jp + 1); 1064 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 1065 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1066 opt = cp[0]; 1067 if (opt == IPOPT_EOL) 1068 break; 1069 if (opt == IPOPT_NOP) { 1070 /* Preserve for IP mcast tunnel's LSRR alignment. */ 1071 *dp++ = IPOPT_NOP; 1072 optlen = 1; 1073 continue; 1074 } 1075 1076 KASSERT(cnt >= IPOPT_OLEN + sizeof(*cp)); 1077 optlen = cp[IPOPT_OLEN]; 1078 KASSERT(optlen >= IPOPT_OLEN + sizeof(*cp) && optlen < cnt); 1079 1080 /* Invalid lengths should have been caught by ip_dooptions. */ 1081 if (optlen > cnt) 1082 optlen = cnt; 1083 if (IPOPT_COPIED(opt)) { 1084 bcopy((void *)cp, (void *)dp, (unsigned)optlen); 1085 dp += optlen; 1086 } 1087 } 1088 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 1089 *dp++ = IPOPT_EOL; 1090 return (optlen); 1091 } 1092 1093 /* 1094 * IP socket option processing. 1095 */ 1096 int 1097 ip_ctloutput(int op, struct socket *so, struct sockopt *sopt) 1098 { 1099 struct inpcb *inp = sotoinpcb(so); 1100 struct ip *ip = &inp->inp_ip; 1101 int inpflags = inp->inp_flags; 1102 int optval = 0, error = 0; 1103 1104 if (sopt->sopt_level != IPPROTO_IP) { 1105 if (sopt->sopt_level == SOL_SOCKET && sopt->sopt_name == SO_NOHEADER) 1106 return 0; 1107 return ENOPROTOOPT; 1108 } 1109 1110 switch (op) { 1111 case PRCO_SETOPT: 1112 switch (sopt->sopt_name) { 1113 case IP_OPTIONS: 1114 #ifdef notyet 1115 case IP_RETOPTS: 1116 #endif 1117 error = ip_pcbopts(inp, sopt); 1118 break; 1119 1120 case IP_TOS: 1121 case IP_TTL: 1122 case IP_MINTTL: 1123 case IP_PKTINFO: 1124 case IP_RECVOPTS: 1125 case IP_RECVRETOPTS: 1126 case IP_RECVDSTADDR: 1127 case IP_RECVIF: 1128 case IP_RECVPKTINFO: 1129 case IP_RECVTTL: 1130 error = sockopt_getint(sopt, &optval); 1131 if (error) 1132 break; 1133 1134 switch (sopt->sopt_name) { 1135 case IP_TOS: 1136 ip->ip_tos = optval; 1137 break; 1138 1139 case IP_TTL: 1140 ip->ip_ttl = optval; 1141 break; 1142 1143 case IP_MINTTL: 1144 if (optval > 0 && optval <= MAXTTL) 1145 inp->inp_ip_minttl = optval; 1146 else 1147 error = EINVAL; 1148 break; 1149 #define OPTSET(bit) \ 1150 if (optval) \ 1151 inpflags |= bit; \ 1152 else \ 1153 inpflags &= ~bit; 1154 1155 case IP_PKTINFO: 1156 OPTSET(INP_PKTINFO); 1157 break; 1158 1159 case IP_RECVOPTS: 1160 OPTSET(INP_RECVOPTS); 1161 break; 1162 1163 case IP_RECVPKTINFO: 1164 OPTSET(INP_RECVPKTINFO); 1165 break; 1166 1167 case IP_RECVRETOPTS: 1168 OPTSET(INP_RECVRETOPTS); 1169 break; 1170 1171 case IP_RECVDSTADDR: 1172 OPTSET(INP_RECVDSTADDR); 1173 break; 1174 1175 case IP_RECVIF: 1176 OPTSET(INP_RECVIF); 1177 break; 1178 1179 case IP_RECVTTL: 1180 OPTSET(INP_RECVTTL); 1181 break; 1182 } 1183 break; 1184 #undef OPTSET 1185 1186 case IP_MULTICAST_IF: 1187 case IP_MULTICAST_TTL: 1188 case IP_MULTICAST_LOOP: 1189 case IP_ADD_MEMBERSHIP: 1190 case IP_DROP_MEMBERSHIP: 1191 error = ip_setmoptions(&inp->inp_moptions, sopt); 1192 break; 1193 1194 case IP_PORTRANGE: 1195 error = sockopt_getint(sopt, &optval); 1196 if (error) 1197 break; 1198 1199 switch (optval) { 1200 case IP_PORTRANGE_DEFAULT: 1201 case IP_PORTRANGE_HIGH: 1202 inpflags &= ~(INP_LOWPORT); 1203 break; 1204 1205 case IP_PORTRANGE_LOW: 1206 inpflags |= INP_LOWPORT; 1207 break; 1208 1209 default: 1210 error = EINVAL; 1211 break; 1212 } 1213 break; 1214 1215 case IP_PORTALGO: 1216 error = sockopt_getint(sopt, &optval); 1217 if (error) 1218 break; 1219 1220 error = portalgo_algo_index_select( 1221 (struct inpcb_hdr *)inp, optval); 1222 break; 1223 1224 #if defined(IPSEC) 1225 case IP_IPSEC_POLICY: 1226 if (ipsec_enabled) { 1227 error = ipsec4_set_policy(inp, sopt->sopt_name, 1228 sopt->sopt_data, sopt->sopt_size, 1229 curlwp->l_cred); 1230 break; 1231 } 1232 /*FALLTHROUGH*/ 1233 #endif /* IPSEC */ 1234 1235 default: 1236 error = ENOPROTOOPT; 1237 break; 1238 } 1239 break; 1240 1241 case PRCO_GETOPT: 1242 switch (sopt->sopt_name) { 1243 case IP_OPTIONS: 1244 case IP_RETOPTS: { 1245 struct mbuf *mopts = inp->inp_options; 1246 1247 if (mopts) { 1248 struct mbuf *m; 1249 1250 m = m_copym(mopts, 0, M_COPYALL, M_DONTWAIT); 1251 if (m == NULL) { 1252 error = ENOBUFS; 1253 break; 1254 } 1255 error = sockopt_setmbuf(sopt, m); 1256 } 1257 break; 1258 } 1259 case IP_PKTINFO: 1260 case IP_TOS: 1261 case IP_TTL: 1262 case IP_MINTTL: 1263 case IP_RECVOPTS: 1264 case IP_RECVRETOPTS: 1265 case IP_RECVDSTADDR: 1266 case IP_RECVIF: 1267 case IP_RECVPKTINFO: 1268 case IP_RECVTTL: 1269 case IP_ERRORMTU: 1270 switch (sopt->sopt_name) { 1271 case IP_TOS: 1272 optval = ip->ip_tos; 1273 break; 1274 1275 case IP_TTL: 1276 optval = ip->ip_ttl; 1277 break; 1278 1279 case IP_MINTTL: 1280 optval = inp->inp_ip_minttl; 1281 break; 1282 1283 case IP_ERRORMTU: 1284 optval = inp->inp_errormtu; 1285 break; 1286 1287 #define OPTBIT(bit) (inpflags & bit ? 1 : 0) 1288 1289 case IP_PKTINFO: 1290 optval = OPTBIT(INP_PKTINFO); 1291 break; 1292 1293 case IP_RECVOPTS: 1294 optval = OPTBIT(INP_RECVOPTS); 1295 break; 1296 1297 case IP_RECVPKTINFO: 1298 optval = OPTBIT(INP_RECVPKTINFO); 1299 break; 1300 1301 case IP_RECVRETOPTS: 1302 optval = OPTBIT(INP_RECVRETOPTS); 1303 break; 1304 1305 case IP_RECVDSTADDR: 1306 optval = OPTBIT(INP_RECVDSTADDR); 1307 break; 1308 1309 case IP_RECVIF: 1310 optval = OPTBIT(INP_RECVIF); 1311 break; 1312 1313 case IP_RECVTTL: 1314 optval = OPTBIT(INP_RECVTTL); 1315 break; 1316 } 1317 error = sockopt_setint(sopt, optval); 1318 break; 1319 1320 #if 0 /* defined(IPSEC) */ 1321 case IP_IPSEC_POLICY: 1322 { 1323 struct mbuf *m = NULL; 1324 1325 /* XXX this will return EINVAL as sopt is empty */ 1326 error = ipsec4_get_policy(inp, sopt->sopt_data, 1327 sopt->sopt_size, &m); 1328 if (error == 0) 1329 error = sockopt_setmbuf(sopt, m); 1330 break; 1331 } 1332 #endif /*IPSEC*/ 1333 1334 case IP_MULTICAST_IF: 1335 case IP_MULTICAST_TTL: 1336 case IP_MULTICAST_LOOP: 1337 case IP_ADD_MEMBERSHIP: 1338 case IP_DROP_MEMBERSHIP: 1339 error = ip_getmoptions(inp->inp_moptions, sopt); 1340 break; 1341 1342 case IP_PORTRANGE: 1343 if (inpflags & INP_LOWPORT) 1344 optval = IP_PORTRANGE_LOW; 1345 else 1346 optval = IP_PORTRANGE_DEFAULT; 1347 error = sockopt_setint(sopt, optval); 1348 break; 1349 1350 case IP_PORTALGO: 1351 optval = inp->inp_portalgo; 1352 error = sockopt_setint(sopt, optval); 1353 break; 1354 1355 default: 1356 error = ENOPROTOOPT; 1357 break; 1358 } 1359 break; 1360 } 1361 1362 if (!error) { 1363 inp->inp_flags = inpflags; 1364 } 1365 return error; 1366 } 1367 1368 /* 1369 * Set up IP options in pcb for insertion in output packets. 1370 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1371 * with destination address if source routed. 1372 */ 1373 static int 1374 ip_pcbopts(struct inpcb *inp, const struct sockopt *sopt) 1375 { 1376 struct mbuf *m; 1377 const u_char *cp; 1378 u_char *dp; 1379 int cnt; 1380 1381 /* Turn off any old options. */ 1382 if (inp->inp_options) { 1383 m_free(inp->inp_options); 1384 } 1385 inp->inp_options = NULL; 1386 if ((cnt = sopt->sopt_size) == 0) { 1387 /* Only turning off any previous options. */ 1388 return 0; 1389 } 1390 cp = sopt->sopt_data; 1391 1392 #ifndef __vax__ 1393 if (cnt % sizeof(int32_t)) 1394 return (EINVAL); 1395 #endif 1396 1397 m = m_get(M_DONTWAIT, MT_SOOPTS); 1398 if (m == NULL) 1399 return (ENOBUFS); 1400 1401 dp = mtod(m, u_char *); 1402 memset(dp, 0, sizeof(struct in_addr)); 1403 dp += sizeof(struct in_addr); 1404 m->m_len = sizeof(struct in_addr); 1405 1406 /* 1407 * IP option list according to RFC791. Each option is of the form 1408 * 1409 * [optval] [olen] [(olen - 2) data bytes] 1410 * 1411 * We validate the list and copy options to an mbuf for prepending 1412 * to data packets. The IP first-hop destination address will be 1413 * stored before actual options and is zero if unset. 1414 */ 1415 while (cnt > 0) { 1416 uint8_t optval, olen, offset; 1417 1418 optval = cp[IPOPT_OPTVAL]; 1419 1420 if (optval == IPOPT_EOL || optval == IPOPT_NOP) { 1421 olen = 1; 1422 } else { 1423 if (cnt < IPOPT_OLEN + 1) 1424 goto bad; 1425 1426 olen = cp[IPOPT_OLEN]; 1427 if (olen < IPOPT_OLEN + 1 || olen > cnt) 1428 goto bad; 1429 } 1430 1431 if (optval == IPOPT_LSRR || optval == IPOPT_SSRR) { 1432 /* 1433 * user process specifies route as: 1434 * ->A->B->C->D 1435 * D must be our final destination (but we can't 1436 * check that since we may not have connected yet). 1437 * A is first hop destination, which doesn't appear in 1438 * actual IP option, but is stored before the options. 1439 */ 1440 if (olen < IPOPT_OFFSET + 1 + sizeof(struct in_addr)) 1441 goto bad; 1442 1443 offset = cp[IPOPT_OFFSET]; 1444 memcpy(mtod(m, u_char *), cp + IPOPT_OFFSET + 1, 1445 sizeof(struct in_addr)); 1446 1447 cp += sizeof(struct in_addr); 1448 cnt -= sizeof(struct in_addr); 1449 olen -= sizeof(struct in_addr); 1450 1451 if (m->m_len + olen > MAX_IPOPTLEN + sizeof(struct in_addr)) 1452 goto bad; 1453 1454 memcpy(dp, cp, olen); 1455 dp[IPOPT_OPTVAL] = optval; 1456 dp[IPOPT_OLEN] = olen; 1457 dp[IPOPT_OFFSET] = offset; 1458 break; 1459 } else { 1460 if (m->m_len + olen > MAX_IPOPTLEN + sizeof(struct in_addr)) 1461 goto bad; 1462 1463 memcpy(dp, cp, olen); 1464 break; 1465 } 1466 1467 dp += olen; 1468 m->m_len += olen; 1469 1470 if (optval == IPOPT_EOL) 1471 break; 1472 1473 cp += olen; 1474 cnt -= olen; 1475 } 1476 1477 inp->inp_options = m; 1478 return 0; 1479 bad: 1480 (void)m_free(m); 1481 return EINVAL; 1482 } 1483 1484 /* 1485 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1486 */ 1487 static struct ifnet * 1488 ip_multicast_if(struct in_addr *a, int *ifindexp) 1489 { 1490 int ifindex; 1491 struct ifnet *ifp = NULL; 1492 struct in_ifaddr *ia; 1493 1494 if (ifindexp) 1495 *ifindexp = 0; 1496 if (ntohl(a->s_addr) >> 24 == 0) { 1497 ifindex = ntohl(a->s_addr) & 0xffffff; 1498 ifp = if_byindex(ifindex); 1499 if (!ifp) 1500 return NULL; 1501 if (ifindexp) 1502 *ifindexp = ifindex; 1503 } else { 1504 LIST_FOREACH(ia, &IN_IFADDR_HASH(a->s_addr), ia_hash) { 1505 if (in_hosteq(ia->ia_addr.sin_addr, *a) && 1506 (ia->ia_ifp->if_flags & IFF_MULTICAST) != 0) { 1507 ifp = ia->ia_ifp; 1508 break; 1509 } 1510 } 1511 } 1512 return ifp; 1513 } 1514 1515 static int 1516 ip_getoptval(const struct sockopt *sopt, u_int8_t *val, u_int maxval) 1517 { 1518 u_int tval; 1519 u_char cval; 1520 int error; 1521 1522 if (sopt == NULL) 1523 return EINVAL; 1524 1525 switch (sopt->sopt_size) { 1526 case sizeof(u_char): 1527 error = sockopt_get(sopt, &cval, sizeof(u_char)); 1528 tval = cval; 1529 break; 1530 1531 case sizeof(u_int): 1532 error = sockopt_get(sopt, &tval, sizeof(u_int)); 1533 break; 1534 1535 default: 1536 error = EINVAL; 1537 } 1538 1539 if (error) 1540 return error; 1541 1542 if (tval > maxval) 1543 return EINVAL; 1544 1545 *val = tval; 1546 return 0; 1547 } 1548 1549 static int 1550 ip_get_membership(const struct sockopt *sopt, struct ifnet **ifp, 1551 struct in_addr *ia, bool add) 1552 { 1553 int error; 1554 struct ip_mreq mreq; 1555 1556 error = sockopt_get(sopt, &mreq, sizeof(mreq)); 1557 if (error) 1558 return error; 1559 1560 if (!IN_MULTICAST(mreq.imr_multiaddr.s_addr)) 1561 return EINVAL; 1562 1563 memcpy(ia, &mreq.imr_multiaddr, sizeof(*ia)); 1564 1565 if (in_nullhost(mreq.imr_interface)) { 1566 union { 1567 struct sockaddr dst; 1568 struct sockaddr_in dst4; 1569 } u; 1570 struct route ro; 1571 1572 if (!add) { 1573 *ifp = NULL; 1574 return 0; 1575 } 1576 /* 1577 * If no interface address was provided, use the interface of 1578 * the route to the given multicast address. 1579 */ 1580 struct rtentry *rt; 1581 memset(&ro, 0, sizeof(ro)); 1582 1583 sockaddr_in_init(&u.dst4, ia, 0); 1584 error = rtcache_setdst(&ro, &u.dst); 1585 if (error != 0) 1586 return error; 1587 *ifp = (rt = rtcache_init(&ro)) != NULL ? rt->rt_ifp : NULL; 1588 rtcache_free(&ro); 1589 } else { 1590 *ifp = ip_multicast_if(&mreq.imr_interface, NULL); 1591 if (!add && *ifp == NULL) 1592 return EADDRNOTAVAIL; 1593 } 1594 return 0; 1595 } 1596 1597 /* 1598 * Add a multicast group membership. 1599 * Group must be a valid IP multicast address. 1600 */ 1601 static int 1602 ip_add_membership(struct ip_moptions *imo, const struct sockopt *sopt) 1603 { 1604 struct ifnet *ifp; 1605 struct in_addr ia; 1606 int i, error; 1607 1608 if (sopt->sopt_size == sizeof(struct ip_mreq)) 1609 error = ip_get_membership(sopt, &ifp, &ia, true); 1610 else 1611 #ifdef INET6 1612 error = ip6_get_membership(sopt, &ifp, &ia, sizeof(ia)); 1613 #else 1614 return EINVAL; 1615 #endif 1616 1617 if (error) 1618 return error; 1619 1620 /* 1621 * See if we found an interface, and confirm that it 1622 * supports multicast. 1623 */ 1624 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) 1625 return EADDRNOTAVAIL; 1626 1627 /* 1628 * See if the membership already exists or if all the 1629 * membership slots are full. 1630 */ 1631 for (i = 0; i < imo->imo_num_memberships; ++i) { 1632 if (imo->imo_membership[i]->inm_ifp == ifp && 1633 in_hosteq(imo->imo_membership[i]->inm_addr, ia)) 1634 break; 1635 } 1636 if (i < imo->imo_num_memberships) 1637 return EADDRINUSE; 1638 1639 if (i == IP_MAX_MEMBERSHIPS) 1640 return ETOOMANYREFS; 1641 1642 /* 1643 * Everything looks good; add a new record to the multicast 1644 * address list for the given interface. 1645 */ 1646 if ((imo->imo_membership[i] = in_addmulti(&ia, ifp)) == NULL) 1647 return ENOBUFS; 1648 1649 ++imo->imo_num_memberships; 1650 return 0; 1651 } 1652 1653 /* 1654 * Drop a multicast group membership. 1655 * Group must be a valid IP multicast address. 1656 */ 1657 static int 1658 ip_drop_membership(struct ip_moptions *imo, const struct sockopt *sopt) 1659 { 1660 struct in_addr ia; 1661 struct ifnet *ifp; 1662 int i, error; 1663 1664 if (sopt->sopt_size == sizeof(struct ip_mreq)) 1665 error = ip_get_membership(sopt, &ifp, &ia, false); 1666 else 1667 #ifdef INET6 1668 error = ip6_get_membership(sopt, &ifp, &ia, sizeof(ia)); 1669 #else 1670 return EINVAL; 1671 #endif 1672 1673 if (error) 1674 return error; 1675 1676 /* 1677 * Find the membership in the membership array. 1678 */ 1679 for (i = 0; i < imo->imo_num_memberships; ++i) { 1680 if ((ifp == NULL || 1681 imo->imo_membership[i]->inm_ifp == ifp) && 1682 in_hosteq(imo->imo_membership[i]->inm_addr, ia)) 1683 break; 1684 } 1685 if (i == imo->imo_num_memberships) 1686 return EADDRNOTAVAIL; 1687 1688 /* 1689 * Give up the multicast address record to which the 1690 * membership points. 1691 */ 1692 in_delmulti(imo->imo_membership[i]); 1693 1694 /* 1695 * Remove the gap in the membership array. 1696 */ 1697 for (++i; i < imo->imo_num_memberships; ++i) 1698 imo->imo_membership[i-1] = imo->imo_membership[i]; 1699 --imo->imo_num_memberships; 1700 return 0; 1701 } 1702 1703 /* 1704 * Set the IP multicast options in response to user setsockopt(). 1705 */ 1706 int 1707 ip_setmoptions(struct ip_moptions **pimo, const struct sockopt *sopt) 1708 { 1709 struct ip_moptions *imo = *pimo; 1710 struct in_addr addr; 1711 struct ifnet *ifp; 1712 int ifindex, error = 0; 1713 1714 if (!imo) { 1715 /* 1716 * No multicast option buffer attached to the pcb; 1717 * allocate one and initialize to default values. 1718 */ 1719 imo = kmem_intr_alloc(sizeof(*imo), KM_NOSLEEP); 1720 if (imo == NULL) 1721 return ENOBUFS; 1722 1723 imo->imo_multicast_ifp = NULL; 1724 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1725 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1726 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1727 imo->imo_num_memberships = 0; 1728 *pimo = imo; 1729 } 1730 1731 switch (sopt->sopt_name) { 1732 case IP_MULTICAST_IF: 1733 /* 1734 * Select the interface for outgoing multicast packets. 1735 */ 1736 error = sockopt_get(sopt, &addr, sizeof(addr)); 1737 if (error) 1738 break; 1739 1740 /* 1741 * INADDR_ANY is used to remove a previous selection. 1742 * When no interface is selected, a default one is 1743 * chosen every time a multicast packet is sent. 1744 */ 1745 if (in_nullhost(addr)) { 1746 imo->imo_multicast_ifp = NULL; 1747 break; 1748 } 1749 /* 1750 * The selected interface is identified by its local 1751 * IP address. Find the interface and confirm that 1752 * it supports multicasting. 1753 */ 1754 ifp = ip_multicast_if(&addr, &ifindex); 1755 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1756 error = EADDRNOTAVAIL; 1757 break; 1758 } 1759 imo->imo_multicast_ifp = ifp; 1760 if (ifindex) 1761 imo->imo_multicast_addr = addr; 1762 else 1763 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1764 break; 1765 1766 case IP_MULTICAST_TTL: 1767 /* 1768 * Set the IP time-to-live for outgoing multicast packets. 1769 */ 1770 error = ip_getoptval(sopt, &imo->imo_multicast_ttl, MAXTTL); 1771 break; 1772 1773 case IP_MULTICAST_LOOP: 1774 /* 1775 * Set the loopback flag for outgoing multicast packets. 1776 * Must be zero or one. 1777 */ 1778 error = ip_getoptval(sopt, &imo->imo_multicast_loop, 1); 1779 break; 1780 1781 case IP_ADD_MEMBERSHIP: /* IPV6_JOIN_GROUP */ 1782 error = ip_add_membership(imo, sopt); 1783 break; 1784 1785 case IP_DROP_MEMBERSHIP: /* IPV6_LEAVE_GROUP */ 1786 error = ip_drop_membership(imo, sopt); 1787 break; 1788 1789 default: 1790 error = EOPNOTSUPP; 1791 break; 1792 } 1793 1794 /* 1795 * If all options have default values, no need to keep the mbuf. 1796 */ 1797 if (imo->imo_multicast_ifp == NULL && 1798 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 1799 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 1800 imo->imo_num_memberships == 0) { 1801 kmem_free(imo, sizeof(*imo)); 1802 *pimo = NULL; 1803 } 1804 1805 return error; 1806 } 1807 1808 /* 1809 * Return the IP multicast options in response to user getsockopt(). 1810 */ 1811 int 1812 ip_getmoptions(struct ip_moptions *imo, struct sockopt *sopt) 1813 { 1814 struct in_addr addr; 1815 struct in_ifaddr *ia; 1816 uint8_t optval; 1817 int error = 0; 1818 1819 switch (sopt->sopt_name) { 1820 case IP_MULTICAST_IF: 1821 if (imo == NULL || imo->imo_multicast_ifp == NULL) 1822 addr = zeroin_addr; 1823 else if (imo->imo_multicast_addr.s_addr) { 1824 /* return the value user has set */ 1825 addr = imo->imo_multicast_addr; 1826 } else { 1827 IFP_TO_IA(imo->imo_multicast_ifp, ia); 1828 addr = ia ? ia->ia_addr.sin_addr : zeroin_addr; 1829 } 1830 error = sockopt_set(sopt, &addr, sizeof(addr)); 1831 break; 1832 1833 case IP_MULTICAST_TTL: 1834 optval = imo ? imo->imo_multicast_ttl 1835 : IP_DEFAULT_MULTICAST_TTL; 1836 1837 error = sockopt_set(sopt, &optval, sizeof(optval)); 1838 break; 1839 1840 case IP_MULTICAST_LOOP: 1841 optval = imo ? imo->imo_multicast_loop 1842 : IP_DEFAULT_MULTICAST_LOOP; 1843 1844 error = sockopt_set(sopt, &optval, sizeof(optval)); 1845 break; 1846 1847 default: 1848 error = EOPNOTSUPP; 1849 } 1850 1851 return error; 1852 } 1853 1854 /* 1855 * Discard the IP multicast options. 1856 */ 1857 void 1858 ip_freemoptions(struct ip_moptions *imo) 1859 { 1860 int i; 1861 1862 if (imo != NULL) { 1863 for (i = 0; i < imo->imo_num_memberships; ++i) 1864 in_delmulti(imo->imo_membership[i]); 1865 kmem_free(imo, sizeof(*imo)); 1866 } 1867 } 1868 1869 /* 1870 * Routine called from ip_output() to loop back a copy of an IP multicast 1871 * packet to the input queue of a specified interface. Note that this 1872 * calls the output routine of the loopback "driver", but with an interface 1873 * pointer that might NOT be lo0ifp -- easier than replicating that code here. 1874 */ 1875 static void 1876 ip_mloopback(struct ifnet *ifp, struct mbuf *m, const struct sockaddr_in *dst) 1877 { 1878 struct ip *ip; 1879 struct mbuf *copym; 1880 1881 copym = m_copypacket(m, M_DONTWAIT); 1882 if (copym != NULL && 1883 (copym->m_flags & M_EXT || copym->m_len < sizeof(struct ip))) 1884 copym = m_pullup(copym, sizeof(struct ip)); 1885 if (copym == NULL) 1886 return; 1887 /* 1888 * We don't bother to fragment if the IP length is greater 1889 * than the interface's MTU. Can this possibly matter? 1890 */ 1891 ip = mtod(copym, struct ip *); 1892 1893 if (copym->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 1894 in_delayed_cksum(copym); 1895 copym->m_pkthdr.csum_flags &= 1896 ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 1897 } 1898 1899 ip->ip_sum = 0; 1900 ip->ip_sum = in_cksum(copym, ip->ip_hl << 2); 1901 #ifndef NET_MPSAFE 1902 KERNEL_LOCK(1, NULL); 1903 #endif 1904 (void)looutput(ifp, copym, sintocsa(dst), NULL); 1905 #ifndef NET_MPSAFE 1906 KERNEL_UNLOCK_ONE(NULL); 1907 #endif 1908 } 1909