ip_output.c revision 1.246
1 /* $NetBSD: ip_output.c,v 1.246 2015/08/24 22:21:26 pooka 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 1.246 2015/08/24 22:21:26 pooka 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 = rt->rt_gwroute = rtalloc1(rt->rt_gateway, 1); 264 RTFREE_IF_NEEDED(rt); 265 rt = gwrt; 266 if (rt == NULL) { 267 error = EHOSTUNREACH; 268 goto bad; 269 } 270 /* the "G" test below also prevents rt == rt0 */ 271 if ((rt->rt_flags & RTF_GATEWAY) != 0 || rt->rt_ifp != ifp) { 272 rt0->rt_gwroute = NULL; 273 error = EHOSTUNREACH; 274 goto bad; 275 } 276 } 277 if ((rt->rt_flags & RTF_REJECT) != 0) { 278 if (rt->rt_rmx.rmx_expire == 0 || 279 time_uptime < rt->rt_rmx.rmx_expire) { 280 error = (rt == rt0) ? EHOSTDOWN : EHOSTUNREACH; 281 goto bad; 282 } 283 } 284 285 out: 286 #ifdef MPLS 287 if (rt0 != NULL && rt_gettag(rt0) != NULL && 288 rt_gettag(rt0)->sa_family == AF_MPLS && 289 (m->m_flags & (M_MCAST | M_BCAST)) == 0 && 290 ifp->if_type == IFT_ETHER) { 291 union mpls_shim msh; 292 msh.s_addr = MPLS_GETSADDR(rt0); 293 if (msh.shim.label != MPLS_LABEL_IMPLNULL) { 294 struct m_tag *mtag; 295 /* 296 * XXX tentative solution to tell ether_output 297 * it's MPLS. Need some more efficient solution. 298 */ 299 mtag = m_tag_get(PACKET_TAG_MPLS, 300 sizeof(int) /* dummy */, 301 M_NOWAIT); 302 if (mtag == NULL) { 303 error = ENOMEM; 304 goto bad; 305 } 306 m_tag_prepend(m, mtag); 307 } 308 } 309 #endif 310 311 error = klock_if_output(ifp, m, dst, rt); 312 goto exit; 313 314 bad: 315 if (m != NULL) 316 m_freem(m); 317 exit: 318 RTFREE_IF_NEEDED(rt); 319 320 return error; 321 322 #undef RTFREE_IF_NEEDED 323 } 324 325 /* 326 * IP output. The packet in mbuf chain m contains a skeletal IP 327 * header (with len, off, ttl, proto, tos, src, dst). 328 * The mbuf chain containing the packet will be freed. 329 * The mbuf opt, if present, will not be freed. 330 */ 331 int 332 ip_output(struct mbuf *m0, ...) 333 { 334 struct rtentry *rt; 335 struct ip *ip; 336 struct ifnet *ifp; 337 struct mbuf *m = m0; 338 int hlen = sizeof (struct ip); 339 int len, error = 0; 340 struct route iproute; 341 const struct sockaddr_in *dst; 342 struct in_ifaddr *ia; 343 int isbroadcast; 344 struct mbuf *opt; 345 struct route *ro; 346 int flags, sw_csum; 347 u_long mtu; 348 struct ip_moptions *imo; 349 struct socket *so; 350 va_list ap; 351 #ifdef IPSEC 352 struct secpolicy *sp = NULL; 353 #endif 354 bool natt_frag = false; 355 bool rtmtu_nolock; 356 union { 357 struct sockaddr dst; 358 struct sockaddr_in dst4; 359 } u; 360 struct sockaddr *rdst = &u.dst; /* real IP destination, as opposed 361 * to the nexthop 362 */ 363 364 len = 0; 365 va_start(ap, m0); 366 opt = va_arg(ap, struct mbuf *); 367 ro = va_arg(ap, struct route *); 368 flags = va_arg(ap, int); 369 imo = va_arg(ap, struct ip_moptions *); 370 so = va_arg(ap, struct socket *); 371 va_end(ap); 372 373 MCLAIM(m, &ip_tx_mowner); 374 375 KASSERT((m->m_flags & M_PKTHDR) != 0); 376 KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_TCPv6|M_CSUM_UDPv6)) == 0); 377 KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) != 378 (M_CSUM_TCPv4|M_CSUM_UDPv4)); 379 380 if (opt) { 381 m = ip_insertoptions(m, opt, &len); 382 if (len >= sizeof(struct ip)) 383 hlen = len; 384 } 385 ip = mtod(m, struct ip *); 386 387 /* 388 * Fill in IP header. 389 */ 390 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 391 ip->ip_v = IPVERSION; 392 ip->ip_off = htons(0); 393 /* ip->ip_id filled in after we find out source ia */ 394 ip->ip_hl = hlen >> 2; 395 IP_STATINC(IP_STAT_LOCALOUT); 396 } else { 397 hlen = ip->ip_hl << 2; 398 } 399 400 /* 401 * Route packet. 402 */ 403 if (ro == NULL) { 404 memset(&iproute, 0, sizeof(iproute)); 405 ro = &iproute; 406 } 407 sockaddr_in_init(&u.dst4, &ip->ip_dst, 0); 408 dst = satocsin(rtcache_getdst(ro)); 409 410 /* 411 * If there is a cached route, check that it is to the same 412 * destination and is still up. If not, free it and try again. 413 * The address family should also be checked in case of sharing 414 * the cache with IPv6. 415 */ 416 if (dst && (dst->sin_family != AF_INET || 417 !in_hosteq(dst->sin_addr, ip->ip_dst))) 418 rtcache_free(ro); 419 420 if ((rt = rtcache_validate(ro)) == NULL && 421 (rt = rtcache_update(ro, 1)) == NULL) { 422 dst = &u.dst4; 423 error = rtcache_setdst(ro, &u.dst); 424 if (error != 0) 425 goto bad; 426 } 427 428 /* 429 * If routing to interface only, short circuit routing lookup. 430 */ 431 if (flags & IP_ROUTETOIF) { 432 if ((ia = ifatoia(ifa_ifwithladdr(sintocsa(dst)))) == NULL) { 433 IP_STATINC(IP_STAT_NOROUTE); 434 error = ENETUNREACH; 435 goto bad; 436 } 437 ifp = ia->ia_ifp; 438 mtu = ifp->if_mtu; 439 ip->ip_ttl = 1; 440 isbroadcast = in_broadcast(dst->sin_addr, ifp); 441 } else if ((IN_MULTICAST(ip->ip_dst.s_addr) || 442 ip->ip_dst.s_addr == INADDR_BROADCAST) && 443 imo != NULL && imo->imo_multicast_ifp != NULL) { 444 ifp = imo->imo_multicast_ifp; 445 mtu = ifp->if_mtu; 446 IFP_TO_IA(ifp, ia); 447 isbroadcast = 0; 448 } else { 449 if (rt == NULL) 450 rt = rtcache_init(ro); 451 if (rt == NULL) { 452 IP_STATINC(IP_STAT_NOROUTE); 453 error = EHOSTUNREACH; 454 goto bad; 455 } 456 ia = ifatoia(rt->rt_ifa); 457 ifp = rt->rt_ifp; 458 if ((mtu = rt->rt_rmx.rmx_mtu) == 0) 459 mtu = ifp->if_mtu; 460 rt->rt_use++; 461 if (rt->rt_flags & RTF_GATEWAY) 462 dst = satosin(rt->rt_gateway); 463 if (rt->rt_flags & RTF_HOST) 464 isbroadcast = rt->rt_flags & RTF_BROADCAST; 465 else 466 isbroadcast = in_broadcast(dst->sin_addr, ifp); 467 } 468 rtmtu_nolock = rt && (rt->rt_rmx.rmx_locks & RTV_MTU) == 0; 469 470 if (IN_MULTICAST(ip->ip_dst.s_addr) || 471 (ip->ip_dst.s_addr == INADDR_BROADCAST)) { 472 bool inmgroup; 473 474 m->m_flags |= (ip->ip_dst.s_addr == INADDR_BROADCAST) ? 475 M_BCAST : M_MCAST; 476 /* 477 * See if the caller provided any multicast options 478 */ 479 if (imo != NULL) 480 ip->ip_ttl = imo->imo_multicast_ttl; 481 else 482 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 483 484 /* 485 * if we don't know the outgoing ifp yet, we can't generate 486 * output 487 */ 488 if (!ifp) { 489 IP_STATINC(IP_STAT_NOROUTE); 490 error = ENETUNREACH; 491 goto bad; 492 } 493 494 /* 495 * If the packet is multicast or broadcast, confirm that 496 * the outgoing interface can transmit it. 497 */ 498 if (((m->m_flags & M_MCAST) && 499 (ifp->if_flags & IFF_MULTICAST) == 0) || 500 ((m->m_flags & M_BCAST) && 501 (ifp->if_flags & (IFF_BROADCAST|IFF_POINTOPOINT)) == 0)) { 502 IP_STATINC(IP_STAT_NOROUTE); 503 error = ENETUNREACH; 504 goto bad; 505 } 506 /* 507 * If source address not specified yet, use an address 508 * of outgoing interface. 509 */ 510 if (in_nullhost(ip->ip_src)) { 511 struct in_ifaddr *xia; 512 struct ifaddr *xifa; 513 514 IFP_TO_IA(ifp, xia); 515 if (!xia) { 516 error = EADDRNOTAVAIL; 517 goto bad; 518 } 519 xifa = &xia->ia_ifa; 520 if (xifa->ifa_getifa != NULL) { 521 xia = ifatoia((*xifa->ifa_getifa)(xifa, rdst)); 522 if (xia == NULL) { 523 error = EADDRNOTAVAIL; 524 goto bad; 525 } 526 } 527 ip->ip_src = xia->ia_addr.sin_addr; 528 } 529 530 inmgroup = in_multi_group(ip->ip_dst, ifp, flags); 531 if (inmgroup && (imo == NULL || imo->imo_multicast_loop)) { 532 /* 533 * If we belong to the destination multicast group 534 * on the outgoing interface, and the caller did not 535 * forbid loopback, loop back a copy. 536 */ 537 ip_mloopback(ifp, m, &u.dst4); 538 } 539 #ifdef MROUTING 540 else { 541 /* 542 * If we are acting as a multicast router, perform 543 * multicast forwarding as if the packet had just 544 * arrived on the interface to which we are about 545 * to send. The multicast forwarding function 546 * recursively calls this function, using the 547 * IP_FORWARDING flag to prevent infinite recursion. 548 * 549 * Multicasts that are looped back by ip_mloopback(), 550 * above, will be forwarded by the ip_input() routine, 551 * if necessary. 552 */ 553 extern struct socket *ip_mrouter; 554 555 if (ip_mrouter && (flags & IP_FORWARDING) == 0) { 556 if (ip_mforward(m, ifp) != 0) { 557 m_freem(m); 558 goto done; 559 } 560 } 561 } 562 #endif 563 /* 564 * Multicasts with a time-to-live of zero may be looped- 565 * back, above, but must not be transmitted on a network. 566 * Also, multicasts addressed to the loopback interface 567 * are not sent -- the above call to ip_mloopback() will 568 * loop back a copy if this host actually belongs to the 569 * destination group on the loopback interface. 570 */ 571 if (ip->ip_ttl == 0 || (ifp->if_flags & IFF_LOOPBACK) != 0) { 572 m_freem(m); 573 goto done; 574 } 575 goto sendit; 576 } 577 578 /* 579 * If source address not specified yet, use address 580 * of outgoing interface. 581 */ 582 if (in_nullhost(ip->ip_src)) { 583 struct ifaddr *xifa; 584 585 xifa = &ia->ia_ifa; 586 if (xifa->ifa_getifa != NULL) { 587 ia = ifatoia((*xifa->ifa_getifa)(xifa, rdst)); 588 if (ia == NULL) { 589 error = EADDRNOTAVAIL; 590 goto bad; 591 } 592 } 593 ip->ip_src = ia->ia_addr.sin_addr; 594 } 595 596 /* 597 * packets with Class-D address as source are not valid per 598 * RFC 1112 599 */ 600 if (IN_MULTICAST(ip->ip_src.s_addr)) { 601 IP_STATINC(IP_STAT_ODROPPED); 602 error = EADDRNOTAVAIL; 603 goto bad; 604 } 605 606 /* 607 * Look for broadcast address and and verify user is allowed to 608 * send such a packet. 609 */ 610 if (isbroadcast) { 611 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 612 error = EADDRNOTAVAIL; 613 goto bad; 614 } 615 if ((flags & IP_ALLOWBROADCAST) == 0) { 616 error = EACCES; 617 goto bad; 618 } 619 /* don't allow broadcast messages to be fragmented */ 620 if (ntohs(ip->ip_len) > ifp->if_mtu) { 621 error = EMSGSIZE; 622 goto bad; 623 } 624 m->m_flags |= M_BCAST; 625 } else 626 m->m_flags &= ~M_BCAST; 627 628 sendit: 629 if ((flags & (IP_FORWARDING|IP_NOIPNEWID)) == 0) { 630 if (m->m_pkthdr.len < IP_MINFRAGSIZE) { 631 ip->ip_id = 0; 632 } else if ((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) { 633 ip->ip_id = ip_newid(ia); 634 } else { 635 636 /* 637 * TSO capable interfaces (typically?) increment 638 * ip_id for each segment. 639 * "allocate" enough ids here to increase the chance 640 * for them to be unique. 641 * 642 * note that the following calculation is not 643 * needed to be precise. wasting some ip_id is fine. 644 */ 645 646 unsigned int segsz = m->m_pkthdr.segsz; 647 unsigned int datasz = ntohs(ip->ip_len) - hlen; 648 unsigned int num = howmany(datasz, segsz); 649 650 ip->ip_id = ip_newid_range(ia, num); 651 } 652 } 653 654 /* 655 * If we're doing Path MTU Discovery, we need to set DF unless 656 * the route's MTU is locked. 657 */ 658 if ((flags & IP_MTUDISC) != 0 && rtmtu_nolock) { 659 ip->ip_off |= htons(IP_DF); 660 } 661 662 #ifdef IPSEC 663 if (ipsec_used) { 664 bool ipsec_done = false; 665 666 /* Perform IPsec processing, if any. */ 667 error = ipsec4_output(m, so, flags, &sp, &mtu, &natt_frag, 668 &ipsec_done); 669 if (error || ipsec_done) 670 goto done; 671 } 672 #endif 673 674 /* 675 * Run through list of hooks for output packets. 676 */ 677 error = pfil_run_hooks(inet_pfil_hook, &m, ifp, PFIL_OUT); 678 if (error) 679 goto done; 680 if (m == NULL) 681 goto done; 682 683 ip = mtod(m, struct ip *); 684 hlen = ip->ip_hl << 2; 685 686 m->m_pkthdr.csum_data |= hlen << 16; 687 688 #if IFA_STATS 689 /* 690 * search for the source address structure to 691 * maintain output statistics. 692 */ 693 INADDR_TO_IA(ip->ip_src, ia); 694 #endif 695 696 /* Maybe skip checksums on loopback interfaces. */ 697 if (IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) { 698 m->m_pkthdr.csum_flags |= M_CSUM_IPv4; 699 } 700 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_csum_flags_tx; 701 /* 702 * If small enough for mtu of path, or if using TCP segmentation 703 * offload, can just send directly. 704 */ 705 if (ntohs(ip->ip_len) <= mtu || 706 (m->m_pkthdr.csum_flags & M_CSUM_TSOv4) != 0) { 707 const struct sockaddr *sa; 708 709 #if IFA_STATS 710 if (ia) 711 ia->ia_ifa.ifa_data.ifad_outbytes += ntohs(ip->ip_len); 712 #endif 713 /* 714 * Always initialize the sum to 0! Some HW assisted 715 * checksumming requires this. 716 */ 717 ip->ip_sum = 0; 718 719 if ((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) { 720 /* 721 * Perform any checksums that the hardware can't do 722 * for us. 723 * 724 * XXX Does any hardware require the {th,uh}_sum 725 * XXX fields to be 0? 726 */ 727 if (sw_csum & M_CSUM_IPv4) { 728 KASSERT(IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)); 729 ip->ip_sum = in_cksum(m, hlen); 730 m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4; 731 } 732 if (sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 733 if (IN_NEED_CHECKSUM(ifp, 734 sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4))) { 735 in_delayed_cksum(m); 736 } 737 m->m_pkthdr.csum_flags &= 738 ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 739 } 740 } 741 742 sa = (m->m_flags & M_MCAST) ? sintocsa(rdst) : sintocsa(dst); 743 if (__predict_true( 744 (m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0 || 745 (ifp->if_capenable & IFCAP_TSOv4) != 0)) { 746 error = ip_hresolv_output(ifp, m, sa, rt); 747 } else { 748 error = ip_tso_output(ifp, m, sa, rt); 749 } 750 goto done; 751 } 752 753 /* 754 * We can't use HW checksumming if we're about to 755 * to fragment the packet. 756 * 757 * XXX Some hardware can do this. 758 */ 759 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 760 if (IN_NEED_CHECKSUM(ifp, 761 m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4))) { 762 in_delayed_cksum(m); 763 } 764 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 765 } 766 767 /* 768 * Too large for interface; fragment if possible. 769 * Must be able to put at least 8 bytes per fragment. 770 */ 771 if (ntohs(ip->ip_off) & IP_DF) { 772 if (flags & IP_RETURNMTU) { 773 struct inpcb *inp; 774 775 KASSERT(so && solocked(so)); 776 inp = sotoinpcb(so); 777 inp->inp_errormtu = mtu; 778 } 779 error = EMSGSIZE; 780 IP_STATINC(IP_STAT_CANTFRAG); 781 goto bad; 782 } 783 784 error = ip_fragment(m, ifp, mtu); 785 if (error) { 786 m = NULL; 787 goto bad; 788 } 789 790 for (; m; m = m0) { 791 m0 = m->m_nextpkt; 792 m->m_nextpkt = 0; 793 if (error) { 794 m_freem(m); 795 continue; 796 } 797 #if IFA_STATS 798 if (ia) 799 ia->ia_ifa.ifa_data.ifad_outbytes += ntohs(ip->ip_len); 800 #endif 801 /* 802 * If we get there, the packet has not been handled by 803 * IPsec whereas it should have. Now that it has been 804 * fragmented, re-inject it in ip_output so that IPsec 805 * processing can occur. 806 */ 807 if (natt_frag) { 808 error = ip_output(m, opt, ro, 809 flags | IP_RAWOUTPUT | IP_NOIPNEWID, 810 imo, so); 811 } else { 812 KASSERT((m->m_pkthdr.csum_flags & 813 (M_CSUM_UDPv4 | M_CSUM_TCPv4)) == 0); 814 error = ip_hresolv_output(ifp, m, 815 (m->m_flags & M_MCAST) ? 816 sintocsa(rdst) : sintocsa(dst), rt); 817 } 818 } 819 if (error == 0) { 820 IP_STATINC(IP_STAT_FRAGMENTED); 821 } 822 done: 823 if (ro == &iproute) { 824 rtcache_free(&iproute); 825 } 826 #ifdef IPSEC 827 if (sp) { 828 KEY_FREESP(&sp); 829 } 830 #endif 831 return error; 832 bad: 833 m_freem(m); 834 goto done; 835 } 836 837 int 838 ip_fragment(struct mbuf *m, struct ifnet *ifp, u_long mtu) 839 { 840 struct ip *ip, *mhip; 841 struct mbuf *m0; 842 int len, hlen, off; 843 int mhlen, firstlen; 844 struct mbuf **mnext; 845 int sw_csum = m->m_pkthdr.csum_flags; 846 int fragments = 0; 847 int s; 848 int error = 0; 849 850 ip = mtod(m, struct ip *); 851 hlen = ip->ip_hl << 2; 852 if (ifp != NULL) 853 sw_csum &= ~ifp->if_csum_flags_tx; 854 855 len = (mtu - hlen) &~ 7; 856 if (len < 8) { 857 m_freem(m); 858 return (EMSGSIZE); 859 } 860 861 firstlen = len; 862 mnext = &m->m_nextpkt; 863 864 /* 865 * Loop through length of segment after first fragment, 866 * make new header and copy data of each part and link onto chain. 867 */ 868 m0 = m; 869 mhlen = sizeof (struct ip); 870 for (off = hlen + len; off < ntohs(ip->ip_len); off += len) { 871 MGETHDR(m, M_DONTWAIT, MT_HEADER); 872 if (m == 0) { 873 error = ENOBUFS; 874 IP_STATINC(IP_STAT_ODROPPED); 875 goto sendorfree; 876 } 877 MCLAIM(m, m0->m_owner); 878 *mnext = m; 879 mnext = &m->m_nextpkt; 880 m->m_data += max_linkhdr; 881 mhip = mtod(m, struct ip *); 882 *mhip = *ip; 883 /* we must inherit MCAST and BCAST flags */ 884 m->m_flags |= m0->m_flags & (M_MCAST|M_BCAST); 885 if (hlen > sizeof (struct ip)) { 886 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 887 mhip->ip_hl = mhlen >> 2; 888 } 889 m->m_len = mhlen; 890 mhip->ip_off = ((off - hlen) >> 3) + 891 (ntohs(ip->ip_off) & ~IP_MF); 892 if (ip->ip_off & htons(IP_MF)) 893 mhip->ip_off |= IP_MF; 894 if (off + len >= ntohs(ip->ip_len)) 895 len = ntohs(ip->ip_len) - off; 896 else 897 mhip->ip_off |= IP_MF; 898 HTONS(mhip->ip_off); 899 mhip->ip_len = htons((u_int16_t)(len + mhlen)); 900 m->m_next = m_copym(m0, off, len, M_DONTWAIT); 901 if (m->m_next == 0) { 902 error = ENOBUFS; /* ??? */ 903 IP_STATINC(IP_STAT_ODROPPED); 904 goto sendorfree; 905 } 906 m->m_pkthdr.len = mhlen + len; 907 m->m_pkthdr.rcvif = NULL; 908 mhip->ip_sum = 0; 909 KASSERT((m->m_pkthdr.csum_flags & M_CSUM_IPv4) == 0); 910 if (sw_csum & M_CSUM_IPv4) { 911 mhip->ip_sum = in_cksum(m, mhlen); 912 } else { 913 /* 914 * checksum is hw-offloaded or not necessary. 915 */ 916 m->m_pkthdr.csum_flags |= 917 m0->m_pkthdr.csum_flags & M_CSUM_IPv4; 918 m->m_pkthdr.csum_data |= mhlen << 16; 919 KASSERT(!(ifp != NULL && 920 IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) || 921 (m->m_pkthdr.csum_flags & M_CSUM_IPv4) != 0); 922 } 923 IP_STATINC(IP_STAT_OFRAGMENTS); 924 fragments++; 925 } 926 /* 927 * Update first fragment by trimming what's been copied out 928 * and updating header, then send each fragment (in order). 929 */ 930 m = m0; 931 m_adj(m, hlen + firstlen - ntohs(ip->ip_len)); 932 m->m_pkthdr.len = hlen + firstlen; 933 ip->ip_len = htons((u_int16_t)m->m_pkthdr.len); 934 ip->ip_off |= htons(IP_MF); 935 ip->ip_sum = 0; 936 if (sw_csum & M_CSUM_IPv4) { 937 ip->ip_sum = in_cksum(m, hlen); 938 m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4; 939 } else { 940 /* 941 * checksum is hw-offloaded or not necessary. 942 */ 943 KASSERT(!(ifp != NULL && IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) || 944 (m->m_pkthdr.csum_flags & M_CSUM_IPv4) != 0); 945 KASSERT(M_CSUM_DATA_IPv4_IPHL(m->m_pkthdr.csum_data) >= 946 sizeof(struct ip)); 947 } 948 sendorfree: 949 /* 950 * If there is no room for all the fragments, don't queue 951 * any of them. 952 */ 953 if (ifp != NULL) { 954 s = splnet(); 955 if (ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len < fragments && 956 error == 0) { 957 error = ENOBUFS; 958 IP_STATINC(IP_STAT_ODROPPED); 959 IFQ_INC_DROPS(&ifp->if_snd); 960 } 961 splx(s); 962 } 963 if (error) { 964 for (m = m0; m; m = m0) { 965 m0 = m->m_nextpkt; 966 m->m_nextpkt = NULL; 967 m_freem(m); 968 } 969 } 970 return (error); 971 } 972 973 /* 974 * Process a delayed payload checksum calculation. 975 */ 976 void 977 in_delayed_cksum(struct mbuf *m) 978 { 979 struct ip *ip; 980 u_int16_t csum, offset; 981 982 ip = mtod(m, struct ip *); 983 offset = ip->ip_hl << 2; 984 csum = in4_cksum(m, 0, offset, ntohs(ip->ip_len) - offset); 985 if (csum == 0 && (m->m_pkthdr.csum_flags & M_CSUM_UDPv4) != 0) 986 csum = 0xffff; 987 988 offset += M_CSUM_DATA_IPv4_OFFSET(m->m_pkthdr.csum_data); 989 990 if ((offset + sizeof(u_int16_t)) > m->m_len) { 991 /* This happen when ip options were inserted 992 printf("in_delayed_cksum: pullup len %d off %d proto %d\n", 993 m->m_len, offset, ip->ip_p); 994 */ 995 m_copyback(m, offset, sizeof(csum), (void *) &csum); 996 } else 997 *(u_int16_t *)(mtod(m, char *) + offset) = csum; 998 } 999 1000 /* 1001 * Determine the maximum length of the options to be inserted; 1002 * we would far rather allocate too much space rather than too little. 1003 */ 1004 1005 u_int 1006 ip_optlen(struct inpcb *inp) 1007 { 1008 struct mbuf *m = inp->inp_options; 1009 1010 if (m && m->m_len > offsetof(struct ipoption, ipopt_dst)) { 1011 return (m->m_len - offsetof(struct ipoption, ipopt_dst)); 1012 } 1013 return 0; 1014 } 1015 1016 /* 1017 * Insert IP options into preformed packet. 1018 * Adjust IP destination as required for IP source routing, 1019 * as indicated by a non-zero in_addr at the start of the options. 1020 */ 1021 static struct mbuf * 1022 ip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phlen) 1023 { 1024 struct ipoption *p = mtod(opt, struct ipoption *); 1025 struct mbuf *n; 1026 struct ip *ip = mtod(m, struct ip *); 1027 unsigned optlen; 1028 1029 optlen = opt->m_len - sizeof(p->ipopt_dst); 1030 if (optlen + ntohs(ip->ip_len) > IP_MAXPACKET) 1031 return (m); /* XXX should fail */ 1032 if (!in_nullhost(p->ipopt_dst)) 1033 ip->ip_dst = p->ipopt_dst; 1034 if (M_READONLY(m) || M_LEADINGSPACE(m) < optlen) { 1035 MGETHDR(n, M_DONTWAIT, MT_HEADER); 1036 if (n == 0) 1037 return (m); 1038 MCLAIM(n, m->m_owner); 1039 M_MOVE_PKTHDR(n, m); 1040 m->m_len -= sizeof(struct ip); 1041 m->m_data += sizeof(struct ip); 1042 n->m_next = m; 1043 m = n; 1044 m->m_len = optlen + sizeof(struct ip); 1045 m->m_data += max_linkhdr; 1046 bcopy((void *)ip, mtod(m, void *), sizeof(struct ip)); 1047 } else { 1048 m->m_data -= optlen; 1049 m->m_len += optlen; 1050 memmove(mtod(m, void *), ip, sizeof(struct ip)); 1051 } 1052 m->m_pkthdr.len += optlen; 1053 ip = mtod(m, struct ip *); 1054 bcopy((void *)p->ipopt_list, (void *)(ip + 1), (unsigned)optlen); 1055 *phlen = sizeof(struct ip) + optlen; 1056 ip->ip_len = htons(ntohs(ip->ip_len) + optlen); 1057 return (m); 1058 } 1059 1060 /* 1061 * Copy options from ip to jp, 1062 * omitting those not copied during fragmentation. 1063 */ 1064 int 1065 ip_optcopy(struct ip *ip, struct ip *jp) 1066 { 1067 u_char *cp, *dp; 1068 int opt, optlen, cnt; 1069 1070 cp = (u_char *)(ip + 1); 1071 dp = (u_char *)(jp + 1); 1072 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 1073 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1074 opt = cp[0]; 1075 if (opt == IPOPT_EOL) 1076 break; 1077 if (opt == IPOPT_NOP) { 1078 /* Preserve for IP mcast tunnel's LSRR alignment. */ 1079 *dp++ = IPOPT_NOP; 1080 optlen = 1; 1081 continue; 1082 } 1083 1084 KASSERT(cnt >= IPOPT_OLEN + sizeof(*cp)); 1085 optlen = cp[IPOPT_OLEN]; 1086 KASSERT(optlen >= IPOPT_OLEN + sizeof(*cp) && optlen < cnt); 1087 1088 /* Invalid lengths should have been caught by ip_dooptions. */ 1089 if (optlen > cnt) 1090 optlen = cnt; 1091 if (IPOPT_COPIED(opt)) { 1092 bcopy((void *)cp, (void *)dp, (unsigned)optlen); 1093 dp += optlen; 1094 } 1095 } 1096 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 1097 *dp++ = IPOPT_EOL; 1098 return (optlen); 1099 } 1100 1101 /* 1102 * IP socket option processing. 1103 */ 1104 int 1105 ip_ctloutput(int op, struct socket *so, struct sockopt *sopt) 1106 { 1107 struct inpcb *inp = sotoinpcb(so); 1108 struct ip *ip = &inp->inp_ip; 1109 int inpflags = inp->inp_flags; 1110 int optval = 0, error = 0; 1111 1112 if (sopt->sopt_level != IPPROTO_IP) { 1113 if (sopt->sopt_level == SOL_SOCKET && sopt->sopt_name == SO_NOHEADER) 1114 return 0; 1115 return ENOPROTOOPT; 1116 } 1117 1118 switch (op) { 1119 case PRCO_SETOPT: 1120 switch (sopt->sopt_name) { 1121 case IP_OPTIONS: 1122 #ifdef notyet 1123 case IP_RETOPTS: 1124 #endif 1125 error = ip_pcbopts(inp, sopt); 1126 break; 1127 1128 case IP_TOS: 1129 case IP_TTL: 1130 case IP_MINTTL: 1131 case IP_PKTINFO: 1132 case IP_RECVOPTS: 1133 case IP_RECVRETOPTS: 1134 case IP_RECVDSTADDR: 1135 case IP_RECVIF: 1136 case IP_RECVPKTINFO: 1137 case IP_RECVTTL: 1138 error = sockopt_getint(sopt, &optval); 1139 if (error) 1140 break; 1141 1142 switch (sopt->sopt_name) { 1143 case IP_TOS: 1144 ip->ip_tos = optval; 1145 break; 1146 1147 case IP_TTL: 1148 ip->ip_ttl = optval; 1149 break; 1150 1151 case IP_MINTTL: 1152 if (optval > 0 && optval <= MAXTTL) 1153 inp->inp_ip_minttl = optval; 1154 else 1155 error = EINVAL; 1156 break; 1157 #define OPTSET(bit) \ 1158 if (optval) \ 1159 inpflags |= bit; \ 1160 else \ 1161 inpflags &= ~bit; 1162 1163 case IP_PKTINFO: 1164 OPTSET(INP_PKTINFO); 1165 break; 1166 1167 case IP_RECVOPTS: 1168 OPTSET(INP_RECVOPTS); 1169 break; 1170 1171 case IP_RECVPKTINFO: 1172 OPTSET(INP_RECVPKTINFO); 1173 break; 1174 1175 case IP_RECVRETOPTS: 1176 OPTSET(INP_RECVRETOPTS); 1177 break; 1178 1179 case IP_RECVDSTADDR: 1180 OPTSET(INP_RECVDSTADDR); 1181 break; 1182 1183 case IP_RECVIF: 1184 OPTSET(INP_RECVIF); 1185 break; 1186 1187 case IP_RECVTTL: 1188 OPTSET(INP_RECVTTL); 1189 break; 1190 } 1191 break; 1192 #undef OPTSET 1193 1194 case IP_MULTICAST_IF: 1195 case IP_MULTICAST_TTL: 1196 case IP_MULTICAST_LOOP: 1197 case IP_ADD_MEMBERSHIP: 1198 case IP_DROP_MEMBERSHIP: 1199 error = ip_setmoptions(&inp->inp_moptions, sopt); 1200 break; 1201 1202 case IP_PORTRANGE: 1203 error = sockopt_getint(sopt, &optval); 1204 if (error) 1205 break; 1206 1207 switch (optval) { 1208 case IP_PORTRANGE_DEFAULT: 1209 case IP_PORTRANGE_HIGH: 1210 inpflags &= ~(INP_LOWPORT); 1211 break; 1212 1213 case IP_PORTRANGE_LOW: 1214 inpflags |= INP_LOWPORT; 1215 break; 1216 1217 default: 1218 error = EINVAL; 1219 break; 1220 } 1221 break; 1222 1223 case IP_PORTALGO: 1224 error = sockopt_getint(sopt, &optval); 1225 if (error) 1226 break; 1227 1228 error = portalgo_algo_index_select( 1229 (struct inpcb_hdr *)inp, optval); 1230 break; 1231 1232 #if defined(IPSEC) 1233 case IP_IPSEC_POLICY: 1234 if (ipsec_enabled) { 1235 error = ipsec4_set_policy(inp, sopt->sopt_name, 1236 sopt->sopt_data, sopt->sopt_size, 1237 curlwp->l_cred); 1238 break; 1239 } 1240 /*FALLTHROUGH*/ 1241 #endif /* IPSEC */ 1242 1243 default: 1244 error = ENOPROTOOPT; 1245 break; 1246 } 1247 break; 1248 1249 case PRCO_GETOPT: 1250 switch (sopt->sopt_name) { 1251 case IP_OPTIONS: 1252 case IP_RETOPTS: { 1253 struct mbuf *mopts = inp->inp_options; 1254 1255 if (mopts) { 1256 struct mbuf *m; 1257 1258 m = m_copym(mopts, 0, M_COPYALL, M_DONTWAIT); 1259 if (m == NULL) { 1260 error = ENOBUFS; 1261 break; 1262 } 1263 error = sockopt_setmbuf(sopt, m); 1264 } 1265 break; 1266 } 1267 case IP_PKTINFO: 1268 case IP_TOS: 1269 case IP_TTL: 1270 case IP_MINTTL: 1271 case IP_RECVOPTS: 1272 case IP_RECVRETOPTS: 1273 case IP_RECVDSTADDR: 1274 case IP_RECVIF: 1275 case IP_RECVPKTINFO: 1276 case IP_RECVTTL: 1277 case IP_ERRORMTU: 1278 switch (sopt->sopt_name) { 1279 case IP_TOS: 1280 optval = ip->ip_tos; 1281 break; 1282 1283 case IP_TTL: 1284 optval = ip->ip_ttl; 1285 break; 1286 1287 case IP_MINTTL: 1288 optval = inp->inp_ip_minttl; 1289 break; 1290 1291 case IP_ERRORMTU: 1292 optval = inp->inp_errormtu; 1293 break; 1294 1295 #define OPTBIT(bit) (inpflags & bit ? 1 : 0) 1296 1297 case IP_PKTINFO: 1298 optval = OPTBIT(INP_PKTINFO); 1299 break; 1300 1301 case IP_RECVOPTS: 1302 optval = OPTBIT(INP_RECVOPTS); 1303 break; 1304 1305 case IP_RECVPKTINFO: 1306 optval = OPTBIT(INP_RECVPKTINFO); 1307 break; 1308 1309 case IP_RECVRETOPTS: 1310 optval = OPTBIT(INP_RECVRETOPTS); 1311 break; 1312 1313 case IP_RECVDSTADDR: 1314 optval = OPTBIT(INP_RECVDSTADDR); 1315 break; 1316 1317 case IP_RECVIF: 1318 optval = OPTBIT(INP_RECVIF); 1319 break; 1320 1321 case IP_RECVTTL: 1322 optval = OPTBIT(INP_RECVTTL); 1323 break; 1324 } 1325 error = sockopt_setint(sopt, optval); 1326 break; 1327 1328 #if 0 /* defined(IPSEC) */ 1329 case IP_IPSEC_POLICY: 1330 { 1331 struct mbuf *m = NULL; 1332 1333 /* XXX this will return EINVAL as sopt is empty */ 1334 error = ipsec4_get_policy(inp, sopt->sopt_data, 1335 sopt->sopt_size, &m); 1336 if (error == 0) 1337 error = sockopt_setmbuf(sopt, m); 1338 break; 1339 } 1340 #endif /*IPSEC*/ 1341 1342 case IP_MULTICAST_IF: 1343 case IP_MULTICAST_TTL: 1344 case IP_MULTICAST_LOOP: 1345 case IP_ADD_MEMBERSHIP: 1346 case IP_DROP_MEMBERSHIP: 1347 error = ip_getmoptions(inp->inp_moptions, sopt); 1348 break; 1349 1350 case IP_PORTRANGE: 1351 if (inpflags & INP_LOWPORT) 1352 optval = IP_PORTRANGE_LOW; 1353 else 1354 optval = IP_PORTRANGE_DEFAULT; 1355 error = sockopt_setint(sopt, optval); 1356 break; 1357 1358 case IP_PORTALGO: 1359 optval = inp->inp_portalgo; 1360 error = sockopt_setint(sopt, optval); 1361 break; 1362 1363 default: 1364 error = ENOPROTOOPT; 1365 break; 1366 } 1367 break; 1368 } 1369 1370 if (!error) { 1371 inp->inp_flags = inpflags; 1372 } 1373 return error; 1374 } 1375 1376 /* 1377 * Set up IP options in pcb for insertion in output packets. 1378 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1379 * with destination address if source routed. 1380 */ 1381 static int 1382 ip_pcbopts(struct inpcb *inp, const struct sockopt *sopt) 1383 { 1384 struct mbuf *m; 1385 const u_char *cp; 1386 u_char *dp; 1387 int cnt; 1388 1389 /* Turn off any old options. */ 1390 if (inp->inp_options) { 1391 m_free(inp->inp_options); 1392 } 1393 inp->inp_options = NULL; 1394 if ((cnt = sopt->sopt_size) == 0) { 1395 /* Only turning off any previous options. */ 1396 return 0; 1397 } 1398 cp = sopt->sopt_data; 1399 1400 #ifndef __vax__ 1401 if (cnt % sizeof(int32_t)) 1402 return (EINVAL); 1403 #endif 1404 1405 m = m_get(M_DONTWAIT, MT_SOOPTS); 1406 if (m == NULL) 1407 return (ENOBUFS); 1408 1409 dp = mtod(m, u_char *); 1410 memset(dp, 0, sizeof(struct in_addr)); 1411 dp += sizeof(struct in_addr); 1412 m->m_len = sizeof(struct in_addr); 1413 1414 /* 1415 * IP option list according to RFC791. Each option is of the form 1416 * 1417 * [optval] [olen] [(olen - 2) data bytes] 1418 * 1419 * We validate the list and copy options to an mbuf for prepending 1420 * to data packets. The IP first-hop destination address will be 1421 * stored before actual options and is zero if unset. 1422 */ 1423 while (cnt > 0) { 1424 uint8_t optval, olen, offset; 1425 1426 optval = cp[IPOPT_OPTVAL]; 1427 1428 if (optval == IPOPT_EOL || optval == IPOPT_NOP) { 1429 olen = 1; 1430 } else { 1431 if (cnt < IPOPT_OLEN + 1) 1432 goto bad; 1433 1434 olen = cp[IPOPT_OLEN]; 1435 if (olen < IPOPT_OLEN + 1 || olen > cnt) 1436 goto bad; 1437 } 1438 1439 if (optval == IPOPT_LSRR || optval == IPOPT_SSRR) { 1440 /* 1441 * user process specifies route as: 1442 * ->A->B->C->D 1443 * D must be our final destination (but we can't 1444 * check that since we may not have connected yet). 1445 * A is first hop destination, which doesn't appear in 1446 * actual IP option, but is stored before the options. 1447 */ 1448 if (olen < IPOPT_OFFSET + 1 + sizeof(struct in_addr)) 1449 goto bad; 1450 1451 offset = cp[IPOPT_OFFSET]; 1452 memcpy(mtod(m, u_char *), cp + IPOPT_OFFSET + 1, 1453 sizeof(struct in_addr)); 1454 1455 cp += sizeof(struct in_addr); 1456 cnt -= sizeof(struct in_addr); 1457 olen -= sizeof(struct in_addr); 1458 1459 if (m->m_len + olen > MAX_IPOPTLEN + sizeof(struct in_addr)) 1460 goto bad; 1461 1462 memcpy(dp, cp, olen); 1463 dp[IPOPT_OPTVAL] = optval; 1464 dp[IPOPT_OLEN] = olen; 1465 dp[IPOPT_OFFSET] = offset; 1466 break; 1467 } else { 1468 if (m->m_len + olen > MAX_IPOPTLEN + sizeof(struct in_addr)) 1469 goto bad; 1470 1471 memcpy(dp, cp, olen); 1472 break; 1473 } 1474 1475 dp += olen; 1476 m->m_len += olen; 1477 1478 if (optval == IPOPT_EOL) 1479 break; 1480 1481 cp += olen; 1482 cnt -= olen; 1483 } 1484 1485 inp->inp_options = m; 1486 return 0; 1487 bad: 1488 (void)m_free(m); 1489 return EINVAL; 1490 } 1491 1492 /* 1493 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1494 */ 1495 static struct ifnet * 1496 ip_multicast_if(struct in_addr *a, int *ifindexp) 1497 { 1498 int ifindex; 1499 struct ifnet *ifp = NULL; 1500 struct in_ifaddr *ia; 1501 1502 if (ifindexp) 1503 *ifindexp = 0; 1504 if (ntohl(a->s_addr) >> 24 == 0) { 1505 ifindex = ntohl(a->s_addr) & 0xffffff; 1506 ifp = if_byindex(ifindex); 1507 if (!ifp) 1508 return NULL; 1509 if (ifindexp) 1510 *ifindexp = ifindex; 1511 } else { 1512 LIST_FOREACH(ia, &IN_IFADDR_HASH(a->s_addr), ia_hash) { 1513 if (in_hosteq(ia->ia_addr.sin_addr, *a) && 1514 (ia->ia_ifp->if_flags & IFF_MULTICAST) != 0) { 1515 ifp = ia->ia_ifp; 1516 break; 1517 } 1518 } 1519 } 1520 return ifp; 1521 } 1522 1523 static int 1524 ip_getoptval(const struct sockopt *sopt, u_int8_t *val, u_int maxval) 1525 { 1526 u_int tval; 1527 u_char cval; 1528 int error; 1529 1530 if (sopt == NULL) 1531 return EINVAL; 1532 1533 switch (sopt->sopt_size) { 1534 case sizeof(u_char): 1535 error = sockopt_get(sopt, &cval, sizeof(u_char)); 1536 tval = cval; 1537 break; 1538 1539 case sizeof(u_int): 1540 error = sockopt_get(sopt, &tval, sizeof(u_int)); 1541 break; 1542 1543 default: 1544 error = EINVAL; 1545 } 1546 1547 if (error) 1548 return error; 1549 1550 if (tval > maxval) 1551 return EINVAL; 1552 1553 *val = tval; 1554 return 0; 1555 } 1556 1557 static int 1558 ip_get_membership(const struct sockopt *sopt, struct ifnet **ifp, 1559 struct in_addr *ia, bool add) 1560 { 1561 int error; 1562 struct ip_mreq mreq; 1563 1564 error = sockopt_get(sopt, &mreq, sizeof(mreq)); 1565 if (error) 1566 return error; 1567 1568 if (!IN_MULTICAST(mreq.imr_multiaddr.s_addr)) 1569 return EINVAL; 1570 1571 memcpy(ia, &mreq.imr_multiaddr, sizeof(*ia)); 1572 1573 if (in_nullhost(mreq.imr_interface)) { 1574 union { 1575 struct sockaddr dst; 1576 struct sockaddr_in dst4; 1577 } u; 1578 struct route ro; 1579 1580 if (!add) { 1581 *ifp = NULL; 1582 return 0; 1583 } 1584 /* 1585 * If no interface address was provided, use the interface of 1586 * the route to the given multicast address. 1587 */ 1588 struct rtentry *rt; 1589 memset(&ro, 0, sizeof(ro)); 1590 1591 sockaddr_in_init(&u.dst4, ia, 0); 1592 error = rtcache_setdst(&ro, &u.dst); 1593 if (error != 0) 1594 return error; 1595 *ifp = (rt = rtcache_init(&ro)) != NULL ? rt->rt_ifp : NULL; 1596 rtcache_free(&ro); 1597 } else { 1598 *ifp = ip_multicast_if(&mreq.imr_interface, NULL); 1599 if (!add && *ifp == NULL) 1600 return EADDRNOTAVAIL; 1601 } 1602 return 0; 1603 } 1604 1605 /* 1606 * Add a multicast group membership. 1607 * Group must be a valid IP multicast address. 1608 */ 1609 static int 1610 ip_add_membership(struct ip_moptions *imo, const struct sockopt *sopt) 1611 { 1612 struct ifnet *ifp; 1613 struct in_addr ia; 1614 int i, error; 1615 1616 if (sopt->sopt_size == sizeof(struct ip_mreq)) 1617 error = ip_get_membership(sopt, &ifp, &ia, true); 1618 else 1619 #ifdef INET6 1620 error = ip6_get_membership(sopt, &ifp, &ia, sizeof(ia)); 1621 #else 1622 return EINVAL; 1623 #endif 1624 1625 if (error) 1626 return error; 1627 1628 /* 1629 * See if we found an interface, and confirm that it 1630 * supports multicast. 1631 */ 1632 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) 1633 return EADDRNOTAVAIL; 1634 1635 /* 1636 * See if the membership already exists or if all the 1637 * membership slots are full. 1638 */ 1639 for (i = 0; i < imo->imo_num_memberships; ++i) { 1640 if (imo->imo_membership[i]->inm_ifp == ifp && 1641 in_hosteq(imo->imo_membership[i]->inm_addr, ia)) 1642 break; 1643 } 1644 if (i < imo->imo_num_memberships) 1645 return EADDRINUSE; 1646 1647 if (i == IP_MAX_MEMBERSHIPS) 1648 return ETOOMANYREFS; 1649 1650 /* 1651 * Everything looks good; add a new record to the multicast 1652 * address list for the given interface. 1653 */ 1654 if ((imo->imo_membership[i] = in_addmulti(&ia, ifp)) == NULL) 1655 return ENOBUFS; 1656 1657 ++imo->imo_num_memberships; 1658 return 0; 1659 } 1660 1661 /* 1662 * Drop a multicast group membership. 1663 * Group must be a valid IP multicast address. 1664 */ 1665 static int 1666 ip_drop_membership(struct ip_moptions *imo, const struct sockopt *sopt) 1667 { 1668 struct in_addr ia; 1669 struct ifnet *ifp; 1670 int i, error; 1671 1672 if (sopt->sopt_size == sizeof(struct ip_mreq)) 1673 error = ip_get_membership(sopt, &ifp, &ia, false); 1674 else 1675 #ifdef INET6 1676 error = ip6_get_membership(sopt, &ifp, &ia, sizeof(ia)); 1677 #else 1678 return EINVAL; 1679 #endif 1680 1681 if (error) 1682 return error; 1683 1684 /* 1685 * Find the membership in the membership array. 1686 */ 1687 for (i = 0; i < imo->imo_num_memberships; ++i) { 1688 if ((ifp == NULL || 1689 imo->imo_membership[i]->inm_ifp == ifp) && 1690 in_hosteq(imo->imo_membership[i]->inm_addr, ia)) 1691 break; 1692 } 1693 if (i == imo->imo_num_memberships) 1694 return EADDRNOTAVAIL; 1695 1696 /* 1697 * Give up the multicast address record to which the 1698 * membership points. 1699 */ 1700 in_delmulti(imo->imo_membership[i]); 1701 1702 /* 1703 * Remove the gap in the membership array. 1704 */ 1705 for (++i; i < imo->imo_num_memberships; ++i) 1706 imo->imo_membership[i-1] = imo->imo_membership[i]; 1707 --imo->imo_num_memberships; 1708 return 0; 1709 } 1710 1711 /* 1712 * Set the IP multicast options in response to user setsockopt(). 1713 */ 1714 int 1715 ip_setmoptions(struct ip_moptions **pimo, const struct sockopt *sopt) 1716 { 1717 struct ip_moptions *imo = *pimo; 1718 struct in_addr addr; 1719 struct ifnet *ifp; 1720 int ifindex, error = 0; 1721 1722 if (!imo) { 1723 /* 1724 * No multicast option buffer attached to the pcb; 1725 * allocate one and initialize to default values. 1726 */ 1727 imo = kmem_intr_alloc(sizeof(*imo), KM_NOSLEEP); 1728 if (imo == NULL) 1729 return ENOBUFS; 1730 1731 imo->imo_multicast_ifp = NULL; 1732 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1733 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1734 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1735 imo->imo_num_memberships = 0; 1736 *pimo = imo; 1737 } 1738 1739 switch (sopt->sopt_name) { 1740 case IP_MULTICAST_IF: 1741 /* 1742 * Select the interface for outgoing multicast packets. 1743 */ 1744 error = sockopt_get(sopt, &addr, sizeof(addr)); 1745 if (error) 1746 break; 1747 1748 /* 1749 * INADDR_ANY is used to remove a previous selection. 1750 * When no interface is selected, a default one is 1751 * chosen every time a multicast packet is sent. 1752 */ 1753 if (in_nullhost(addr)) { 1754 imo->imo_multicast_ifp = NULL; 1755 break; 1756 } 1757 /* 1758 * The selected interface is identified by its local 1759 * IP address. Find the interface and confirm that 1760 * it supports multicasting. 1761 */ 1762 ifp = ip_multicast_if(&addr, &ifindex); 1763 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1764 error = EADDRNOTAVAIL; 1765 break; 1766 } 1767 imo->imo_multicast_ifp = ifp; 1768 if (ifindex) 1769 imo->imo_multicast_addr = addr; 1770 else 1771 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1772 break; 1773 1774 case IP_MULTICAST_TTL: 1775 /* 1776 * Set the IP time-to-live for outgoing multicast packets. 1777 */ 1778 error = ip_getoptval(sopt, &imo->imo_multicast_ttl, MAXTTL); 1779 break; 1780 1781 case IP_MULTICAST_LOOP: 1782 /* 1783 * Set the loopback flag for outgoing multicast packets. 1784 * Must be zero or one. 1785 */ 1786 error = ip_getoptval(sopt, &imo->imo_multicast_loop, 1); 1787 break; 1788 1789 case IP_ADD_MEMBERSHIP: /* IPV6_JOIN_GROUP */ 1790 error = ip_add_membership(imo, sopt); 1791 break; 1792 1793 case IP_DROP_MEMBERSHIP: /* IPV6_LEAVE_GROUP */ 1794 error = ip_drop_membership(imo, sopt); 1795 break; 1796 1797 default: 1798 error = EOPNOTSUPP; 1799 break; 1800 } 1801 1802 /* 1803 * If all options have default values, no need to keep the mbuf. 1804 */ 1805 if (imo->imo_multicast_ifp == NULL && 1806 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 1807 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 1808 imo->imo_num_memberships == 0) { 1809 kmem_free(imo, sizeof(*imo)); 1810 *pimo = NULL; 1811 } 1812 1813 return error; 1814 } 1815 1816 /* 1817 * Return the IP multicast options in response to user getsockopt(). 1818 */ 1819 int 1820 ip_getmoptions(struct ip_moptions *imo, struct sockopt *sopt) 1821 { 1822 struct in_addr addr; 1823 struct in_ifaddr *ia; 1824 uint8_t optval; 1825 int error = 0; 1826 1827 switch (sopt->sopt_name) { 1828 case IP_MULTICAST_IF: 1829 if (imo == NULL || imo->imo_multicast_ifp == NULL) 1830 addr = zeroin_addr; 1831 else if (imo->imo_multicast_addr.s_addr) { 1832 /* return the value user has set */ 1833 addr = imo->imo_multicast_addr; 1834 } else { 1835 IFP_TO_IA(imo->imo_multicast_ifp, ia); 1836 addr = ia ? ia->ia_addr.sin_addr : zeroin_addr; 1837 } 1838 error = sockopt_set(sopt, &addr, sizeof(addr)); 1839 break; 1840 1841 case IP_MULTICAST_TTL: 1842 optval = imo ? imo->imo_multicast_ttl 1843 : IP_DEFAULT_MULTICAST_TTL; 1844 1845 error = sockopt_set(sopt, &optval, sizeof(optval)); 1846 break; 1847 1848 case IP_MULTICAST_LOOP: 1849 optval = imo ? imo->imo_multicast_loop 1850 : IP_DEFAULT_MULTICAST_LOOP; 1851 1852 error = sockopt_set(sopt, &optval, sizeof(optval)); 1853 break; 1854 1855 default: 1856 error = EOPNOTSUPP; 1857 } 1858 1859 return error; 1860 } 1861 1862 /* 1863 * Discard the IP multicast options. 1864 */ 1865 void 1866 ip_freemoptions(struct ip_moptions *imo) 1867 { 1868 int i; 1869 1870 if (imo != NULL) { 1871 for (i = 0; i < imo->imo_num_memberships; ++i) 1872 in_delmulti(imo->imo_membership[i]); 1873 kmem_free(imo, sizeof(*imo)); 1874 } 1875 } 1876 1877 /* 1878 * Routine called from ip_output() to loop back a copy of an IP multicast 1879 * packet to the input queue of a specified interface. Note that this 1880 * calls the output routine of the loopback "driver", but with an interface 1881 * pointer that might NOT be lo0ifp -- easier than replicating that code here. 1882 */ 1883 static void 1884 ip_mloopback(struct ifnet *ifp, struct mbuf *m, const struct sockaddr_in *dst) 1885 { 1886 struct ip *ip; 1887 struct mbuf *copym; 1888 1889 copym = m_copypacket(m, M_DONTWAIT); 1890 if (copym != NULL && 1891 (copym->m_flags & M_EXT || copym->m_len < sizeof(struct ip))) 1892 copym = m_pullup(copym, sizeof(struct ip)); 1893 if (copym == NULL) 1894 return; 1895 /* 1896 * We don't bother to fragment if the IP length is greater 1897 * than the interface's MTU. Can this possibly matter? 1898 */ 1899 ip = mtod(copym, struct ip *); 1900 1901 if (copym->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 1902 in_delayed_cksum(copym); 1903 copym->m_pkthdr.csum_flags &= 1904 ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 1905 } 1906 1907 ip->ip_sum = 0; 1908 ip->ip_sum = in_cksum(copym, ip->ip_hl << 2); 1909 #ifndef NET_MPSAFE 1910 KERNEL_LOCK(1, NULL); 1911 #endif 1912 (void)looutput(ifp, copym, sintocsa(dst), NULL); 1913 #ifndef NET_MPSAFE 1914 KERNEL_UNLOCK_ONE(NULL); 1915 #endif 1916 } 1917
Indexes created Tue Sep 23 23:09:58 GMT 2025