ip_output.c revision 1.259.2.2
1 /* $NetBSD: ip_output.c,v 1.259.2.2 2016/11/04 14:49:21 pgoyette 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 1.259.2.2 2016/11/04 14:49:21 pgoyette 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 "arp.h" 105 106 #include <sys/param.h> 107 #include <sys/kmem.h> 108 #include <sys/mbuf.h> 109 #include <sys/protosw.h> 110 #include <sys/socket.h> 111 #include <sys/socketvar.h> 112 #include <sys/kauth.h> 113 #ifdef IPSEC 114 #include <sys/domain.h> 115 #endif 116 #include <sys/systm.h> 117 #include <sys/syslog.h> 118 119 #include <net/if.h> 120 #include <net/if_types.h> 121 #include <net/route.h> 122 #include <net/pfil.h> 123 124 #include <netinet/in.h> 125 #include <netinet/in_systm.h> 126 #include <netinet/ip.h> 127 #include <netinet/in_pcb.h> 128 #include <netinet/in_var.h> 129 #include <netinet/ip_var.h> 130 #include <netinet/ip_private.h> 131 #include <netinet/in_offload.h> 132 #include <netinet/portalgo.h> 133 #include <netinet/udp.h> 134 135 #ifdef INET6 136 #include <netinet6/ip6_var.h> 137 #endif 138 139 #ifdef MROUTING 140 #include <netinet/ip_mroute.h> 141 #endif 142 143 #ifdef IPSEC 144 #include <netipsec/ipsec.h> 145 #include <netipsec/key.h> 146 #endif 147 148 #ifdef MPLS 149 #include <netmpls/mpls.h> 150 #include <netmpls/mpls_var.h> 151 #endif 152 153 static int ip_pcbopts(struct inpcb *, const struct sockopt *); 154 static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *); 155 static struct ifnet *ip_multicast_if(struct in_addr *, int *); 156 static void ip_mloopback(struct ifnet *, struct mbuf *, 157 const struct sockaddr_in *); 158 static int ip_ifaddrvalid(const struct in_ifaddr *); 159 160 extern pfil_head_t *inet_pfil_hook; /* XXX */ 161 162 int ip_do_loopback_cksum = 0; 163 164 static int 165 ip_mark_mpls(struct ifnet * const ifp, struct mbuf * const m, 166 const struct rtentry *rt) 167 { 168 int error = 0; 169 #ifdef MPLS 170 union mpls_shim msh; 171 172 if (rt == NULL || rt_gettag(rt) == NULL || 173 rt_gettag(rt)->sa_family != AF_MPLS || 174 (m->m_flags & (M_MCAST | M_BCAST)) != 0 || 175 ifp->if_type != IFT_ETHER) 176 return 0; 177 178 msh.s_addr = MPLS_GETSADDR(rt); 179 if (msh.shim.label != MPLS_LABEL_IMPLNULL) { 180 struct m_tag *mtag; 181 /* 182 * XXX tentative solution to tell ether_output 183 * it's MPLS. Need some more efficient solution. 184 */ 185 mtag = m_tag_get(PACKET_TAG_MPLS, 186 sizeof(int) /* dummy */, 187 M_NOWAIT); 188 if (mtag == NULL) 189 return ENOMEM; 190 m_tag_prepend(m, mtag); 191 } 192 #endif 193 return error; 194 } 195 196 /* 197 * Send an IP packet to a host. 198 */ 199 int 200 ip_if_output(struct ifnet * const ifp, struct mbuf * const m, 201 const struct sockaddr * const dst, const struct rtentry *rt) 202 { 203 int error = 0; 204 205 if (rt != NULL) { 206 error = rt_check_reject_route(rt, ifp); 207 if (error != 0) { 208 m_freem(m); 209 return error; 210 } 211 } 212 213 error = ip_mark_mpls(ifp, m, rt); 214 if (error != 0) { 215 m_freem(m); 216 return error; 217 } 218 219 error = if_output_lock(ifp, ifp, m, dst, rt); 220 221 return error; 222 } 223 224 /* 225 * IP output. The packet in mbuf chain m contains a skeletal IP 226 * header (with len, off, ttl, proto, tos, src, dst). 227 * The mbuf chain containing the packet will be freed. 228 * The mbuf opt, if present, will not be freed. 229 */ 230 int 231 ip_output(struct mbuf *m0, struct mbuf *opt, struct route *ro, int flags, 232 struct ip_moptions *imo, struct socket *so) 233 { 234 struct rtentry *rt; 235 struct ip *ip; 236 struct ifnet *ifp, *mifp = NULL; 237 struct mbuf *m = m0; 238 int hlen = sizeof (struct ip); 239 int len, error = 0; 240 struct route iproute; 241 const struct sockaddr_in *dst; 242 struct in_ifaddr *ia = NULL; 243 int isbroadcast; 244 int sw_csum; 245 u_long mtu; 246 #ifdef IPSEC 247 struct secpolicy *sp = NULL; 248 #endif 249 bool natt_frag = false; 250 bool rtmtu_nolock; 251 union { 252 struct sockaddr dst; 253 struct sockaddr_in dst4; 254 } u; 255 struct sockaddr *rdst = &u.dst; /* real IP destination, as opposed 256 * to the nexthop 257 */ 258 struct psref psref, psref_ia; 259 int bound; 260 bool bind_need_restore = false; 261 262 len = 0; 263 264 MCLAIM(m, &ip_tx_mowner); 265 266 KASSERT((m->m_flags & M_PKTHDR) != 0); 267 KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_TCPv6|M_CSUM_UDPv6)) == 0); 268 KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) != 269 (M_CSUM_TCPv4|M_CSUM_UDPv4)); 270 271 if (opt) { 272 m = ip_insertoptions(m, opt, &len); 273 if (len >= sizeof(struct ip)) 274 hlen = len; 275 } 276 ip = mtod(m, struct ip *); 277 278 /* 279 * Fill in IP header. 280 */ 281 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 282 ip->ip_v = IPVERSION; 283 ip->ip_off = htons(0); 284 /* ip->ip_id filled in after we find out source ia */ 285 ip->ip_hl = hlen >> 2; 286 IP_STATINC(IP_STAT_LOCALOUT); 287 } else { 288 hlen = ip->ip_hl << 2; 289 } 290 291 /* 292 * Route packet. 293 */ 294 if (ro == NULL) { 295 memset(&iproute, 0, sizeof(iproute)); 296 ro = &iproute; 297 } 298 sockaddr_in_init(&u.dst4, &ip->ip_dst, 0); 299 dst = satocsin(rtcache_getdst(ro)); 300 301 /* 302 * If there is a cached route, check that it is to the same 303 * destination and is still up. If not, free it and try again. 304 * The address family should also be checked in case of sharing 305 * the cache with IPv6. 306 */ 307 if (dst && (dst->sin_family != AF_INET || 308 !in_hosteq(dst->sin_addr, ip->ip_dst))) 309 rtcache_free(ro); 310 311 if ((rt = rtcache_validate(ro)) == NULL && 312 (rt = rtcache_update(ro, 1)) == NULL) { 313 dst = &u.dst4; 314 error = rtcache_setdst(ro, &u.dst); 315 if (error != 0) 316 goto bad; 317 } 318 319 bound = curlwp_bind(); 320 bind_need_restore = true; 321 /* 322 * If routing to interface only, short circuit routing lookup. 323 */ 324 if (flags & IP_ROUTETOIF) { 325 struct ifaddr *ifa; 326 327 ifa = ifa_ifwithladdr_psref(sintocsa(dst), &psref_ia); 328 if (ifa == NULL) { 329 IP_STATINC(IP_STAT_NOROUTE); 330 error = ENETUNREACH; 331 goto bad; 332 } 333 /* ia is already referenced by psref_ia */ 334 ia = ifatoia(ifa); 335 336 ifp = ia->ia_ifp; 337 mtu = ifp->if_mtu; 338 ip->ip_ttl = 1; 339 isbroadcast = in_broadcast(dst->sin_addr, ifp); 340 } else if ((IN_MULTICAST(ip->ip_dst.s_addr) || 341 ip->ip_dst.s_addr == INADDR_BROADCAST) && 342 imo != NULL && imo->imo_multicast_if_index != 0) { 343 ifp = mifp = if_get_byindex(imo->imo_multicast_if_index, &psref); 344 if (ifp == NULL) { 345 IP_STATINC(IP_STAT_NOROUTE); 346 error = ENETUNREACH; 347 goto bad; 348 } 349 mtu = ifp->if_mtu; 350 ia = in_get_ia_from_ifp_psref(ifp, &psref_ia); 351 if (ia == NULL) { 352 error = EADDRNOTAVAIL; 353 goto bad; 354 } 355 isbroadcast = 0; 356 } else { 357 if (rt == NULL) 358 rt = rtcache_init(ro); 359 if (rt == NULL) { 360 IP_STATINC(IP_STAT_NOROUTE); 361 error = EHOSTUNREACH; 362 goto bad; 363 } 364 /* 365 * XXX NOMPSAFE: depends on accessing rt->rt_ifa isn't racy. 366 * Revisit when working on rtentry MP-ification. 367 */ 368 ifa_acquire(rt->rt_ifa, &psref_ia); 369 ia = ifatoia(rt->rt_ifa); 370 ifp = rt->rt_ifp; 371 if ((mtu = rt->rt_rmx.rmx_mtu) == 0) 372 mtu = ifp->if_mtu; 373 rt->rt_use++; 374 if (rt->rt_flags & RTF_GATEWAY) 375 dst = satosin(rt->rt_gateway); 376 if (rt->rt_flags & RTF_HOST) 377 isbroadcast = rt->rt_flags & RTF_BROADCAST; 378 else 379 isbroadcast = in_broadcast(dst->sin_addr, ifp); 380 } 381 rtmtu_nolock = rt && (rt->rt_rmx.rmx_locks & RTV_MTU) == 0; 382 383 if (IN_MULTICAST(ip->ip_dst.s_addr) || 384 (ip->ip_dst.s_addr == INADDR_BROADCAST)) { 385 bool inmgroup; 386 387 m->m_flags |= (ip->ip_dst.s_addr == INADDR_BROADCAST) ? 388 M_BCAST : M_MCAST; 389 /* 390 * See if the caller provided any multicast options 391 */ 392 if (imo != NULL) 393 ip->ip_ttl = imo->imo_multicast_ttl; 394 else 395 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 396 397 /* 398 * if we don't know the outgoing ifp yet, we can't generate 399 * output 400 */ 401 if (!ifp) { 402 IP_STATINC(IP_STAT_NOROUTE); 403 error = ENETUNREACH; 404 goto bad; 405 } 406 407 /* 408 * If the packet is multicast or broadcast, confirm that 409 * the outgoing interface can transmit it. 410 */ 411 if (((m->m_flags & M_MCAST) && 412 (ifp->if_flags & IFF_MULTICAST) == 0) || 413 ((m->m_flags & M_BCAST) && 414 (ifp->if_flags & (IFF_BROADCAST|IFF_POINTOPOINT)) == 0)) { 415 IP_STATINC(IP_STAT_NOROUTE); 416 error = ENETUNREACH; 417 goto bad; 418 } 419 /* 420 * If source address not specified yet, use an address 421 * of outgoing interface. 422 */ 423 if (in_nullhost(ip->ip_src)) { 424 struct in_ifaddr *xia; 425 struct ifaddr *xifa; 426 struct psref _psref; 427 428 xia = in_get_ia_from_ifp_psref(ifp, &_psref); 429 if (!xia) { 430 error = EADDRNOTAVAIL; 431 goto bad; 432 } 433 xifa = &xia->ia_ifa; 434 if (xifa->ifa_getifa != NULL) { 435 ia4_release(xia, &_psref); 436 /* FIXME NOMPSAFE */ 437 xia = ifatoia((*xifa->ifa_getifa)(xifa, rdst)); 438 if (xia == NULL) { 439 error = EADDRNOTAVAIL; 440 goto bad; 441 } 442 ia4_acquire(xia, &_psref); 443 } 444 ip->ip_src = xia->ia_addr.sin_addr; 445 ia4_release(xia, &_psref); 446 } 447 448 inmgroup = in_multi_group(ip->ip_dst, ifp, flags); 449 if (inmgroup && (imo == NULL || imo->imo_multicast_loop)) { 450 /* 451 * If we belong to the destination multicast group 452 * on the outgoing interface, and the caller did not 453 * forbid loopback, loop back a copy. 454 */ 455 ip_mloopback(ifp, m, &u.dst4); 456 } 457 #ifdef MROUTING 458 else { 459 /* 460 * If we are acting as a multicast router, perform 461 * multicast forwarding as if the packet had just 462 * arrived on the interface to which we are about 463 * to send. The multicast forwarding function 464 * recursively calls this function, using the 465 * IP_FORWARDING flag to prevent infinite recursion. 466 * 467 * Multicasts that are looped back by ip_mloopback(), 468 * above, will be forwarded by the ip_input() routine, 469 * if necessary. 470 */ 471 extern struct socket *ip_mrouter; 472 473 if (ip_mrouter && (flags & IP_FORWARDING) == 0) { 474 if (ip_mforward(m, ifp) != 0) { 475 m_freem(m); 476 goto done; 477 } 478 } 479 } 480 #endif 481 /* 482 * Multicasts with a time-to-live of zero may be looped- 483 * back, above, but must not be transmitted on a network. 484 * Also, multicasts addressed to the loopback interface 485 * are not sent -- the above call to ip_mloopback() will 486 * loop back a copy if this host actually belongs to the 487 * destination group on the loopback interface. 488 */ 489 if (ip->ip_ttl == 0 || (ifp->if_flags & IFF_LOOPBACK) != 0) { 490 m_freem(m); 491 goto done; 492 } 493 goto sendit; 494 } 495 496 /* 497 * If source address not specified yet, use address 498 * of outgoing interface. 499 */ 500 if (in_nullhost(ip->ip_src)) { 501 struct ifaddr *xifa; 502 503 xifa = &ia->ia_ifa; 504 if (xifa->ifa_getifa != NULL) { 505 ia4_release(ia, &psref_ia); 506 /* FIXME NOMPSAFE */ 507 ia = ifatoia((*xifa->ifa_getifa)(xifa, rdst)); 508 if (ia == NULL) { 509 error = EADDRNOTAVAIL; 510 goto bad; 511 } 512 ia4_acquire(ia, &psref_ia); 513 } 514 ip->ip_src = ia->ia_addr.sin_addr; 515 } 516 517 /* 518 * packets with Class-D address as source are not valid per 519 * RFC 1112 520 */ 521 if (IN_MULTICAST(ip->ip_src.s_addr)) { 522 IP_STATINC(IP_STAT_ODROPPED); 523 error = EADDRNOTAVAIL; 524 goto bad; 525 } 526 527 /* 528 * Look for broadcast address and and verify user is allowed to 529 * send such a packet. 530 */ 531 if (isbroadcast) { 532 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 533 error = EADDRNOTAVAIL; 534 goto bad; 535 } 536 if ((flags & IP_ALLOWBROADCAST) == 0) { 537 error = EACCES; 538 goto bad; 539 } 540 /* don't allow broadcast messages to be fragmented */ 541 if (ntohs(ip->ip_len) > ifp->if_mtu) { 542 error = EMSGSIZE; 543 goto bad; 544 } 545 m->m_flags |= M_BCAST; 546 } else 547 m->m_flags &= ~M_BCAST; 548 549 sendit: 550 if ((flags & (IP_FORWARDING|IP_NOIPNEWID)) == 0) { 551 if (m->m_pkthdr.len < IP_MINFRAGSIZE) { 552 ip->ip_id = 0; 553 } else if ((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) { 554 ip->ip_id = ip_newid(ia); 555 } else { 556 557 /* 558 * TSO capable interfaces (typically?) increment 559 * ip_id for each segment. 560 * "allocate" enough ids here to increase the chance 561 * for them to be unique. 562 * 563 * note that the following calculation is not 564 * needed to be precise. wasting some ip_id is fine. 565 */ 566 567 unsigned int segsz = m->m_pkthdr.segsz; 568 unsigned int datasz = ntohs(ip->ip_len) - hlen; 569 unsigned int num = howmany(datasz, segsz); 570 571 ip->ip_id = ip_newid_range(ia, num); 572 } 573 } 574 if (ia != NULL) { 575 ia4_release(ia, &psref_ia); 576 ia = NULL; 577 } 578 579 /* 580 * If we're doing Path MTU Discovery, we need to set DF unless 581 * the route's MTU is locked. 582 */ 583 if ((flags & IP_MTUDISC) != 0 && rtmtu_nolock) { 584 ip->ip_off |= htons(IP_DF); 585 } 586 587 #ifdef IPSEC 588 if (ipsec_used) { 589 bool ipsec_done = false; 590 591 /* Perform IPsec processing, if any. */ 592 error = ipsec4_output(m, so, flags, &sp, &mtu, &natt_frag, 593 &ipsec_done); 594 if (error || ipsec_done) 595 goto done; 596 } 597 #endif 598 599 /* 600 * Run through list of hooks for output packets. 601 */ 602 error = pfil_run_hooks(inet_pfil_hook, &m, ifp, PFIL_OUT); 603 if (error) 604 goto done; 605 if (m == NULL) 606 goto done; 607 608 ip = mtod(m, struct ip *); 609 hlen = ip->ip_hl << 2; 610 611 m->m_pkthdr.csum_data |= hlen << 16; 612 613 /* 614 * search for the source address structure to 615 * maintain output statistics. 616 */ 617 KASSERT(ia == NULL); 618 ia = in_get_ia_psref(ip->ip_src, &psref_ia); 619 620 /* Ensure we only send from a valid address. */ 621 if ((ia != NULL || (flags & IP_FORWARDING) == 0) && 622 (error = ip_ifaddrvalid(ia)) != 0) 623 { 624 arplog(LOG_ERR, 625 "refusing to send from invalid address %s (pid %d)\n", 626 in_fmtaddr(ip->ip_src), curproc->p_pid); 627 IP_STATINC(IP_STAT_ODROPPED); 628 if (error == 1) 629 /* 630 * Address exists, but is tentative or detached. 631 * We can't send from it because it's invalid, 632 * so we drop the packet. 633 */ 634 error = 0; 635 else 636 error = EADDRNOTAVAIL; 637 goto bad; 638 } 639 640 /* Maybe skip checksums on loopback interfaces. */ 641 if (IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) { 642 m->m_pkthdr.csum_flags |= M_CSUM_IPv4; 643 } 644 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_csum_flags_tx; 645 /* 646 * If small enough for mtu of path, or if using TCP segmentation 647 * offload, can just send directly. 648 */ 649 if (ntohs(ip->ip_len) <= mtu || 650 (m->m_pkthdr.csum_flags & M_CSUM_TSOv4) != 0) { 651 const struct sockaddr *sa; 652 653 #if IFA_STATS 654 if (ia) 655 ia->ia_ifa.ifa_data.ifad_outbytes += ntohs(ip->ip_len); 656 #endif 657 /* 658 * Always initialize the sum to 0! Some HW assisted 659 * checksumming requires this. 660 */ 661 ip->ip_sum = 0; 662 663 if ((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) { 664 /* 665 * Perform any checksums that the hardware can't do 666 * for us. 667 * 668 * XXX Does any hardware require the {th,uh}_sum 669 * XXX fields to be 0? 670 */ 671 if (sw_csum & M_CSUM_IPv4) { 672 KASSERT(IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)); 673 ip->ip_sum = in_cksum(m, hlen); 674 m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4; 675 } 676 if (sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 677 if (IN_NEED_CHECKSUM(ifp, 678 sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4))) { 679 in_delayed_cksum(m); 680 } 681 m->m_pkthdr.csum_flags &= 682 ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 683 } 684 } 685 686 sa = (m->m_flags & M_MCAST) ? sintocsa(rdst) : sintocsa(dst); 687 if (__predict_true( 688 (m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0 || 689 (ifp->if_capenable & IFCAP_TSOv4) != 0)) { 690 error = ip_if_output(ifp, m, sa, rt); 691 } else { 692 error = ip_tso_output(ifp, m, sa, rt); 693 } 694 goto done; 695 } 696 697 /* 698 * We can't use HW checksumming if we're about to 699 * to fragment the packet. 700 * 701 * XXX Some hardware can do this. 702 */ 703 if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 704 if (IN_NEED_CHECKSUM(ifp, 705 m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4))) { 706 in_delayed_cksum(m); 707 } 708 m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 709 } 710 711 /* 712 * Too large for interface; fragment if possible. 713 * Must be able to put at least 8 bytes per fragment. 714 */ 715 if (ntohs(ip->ip_off) & IP_DF) { 716 if (flags & IP_RETURNMTU) { 717 struct inpcb *inp; 718 719 KASSERT(so && solocked(so)); 720 inp = sotoinpcb(so); 721 inp->inp_errormtu = mtu; 722 } 723 error = EMSGSIZE; 724 IP_STATINC(IP_STAT_CANTFRAG); 725 goto bad; 726 } 727 728 error = ip_fragment(m, ifp, mtu); 729 if (error) { 730 m = NULL; 731 goto bad; 732 } 733 734 for (; m; m = m0) { 735 m0 = m->m_nextpkt; 736 m->m_nextpkt = 0; 737 if (error) { 738 m_freem(m); 739 continue; 740 } 741 #if IFA_STATS 742 if (ia) 743 ia->ia_ifa.ifa_data.ifad_outbytes += ntohs(ip->ip_len); 744 #endif 745 /* 746 * If we get there, the packet has not been handled by 747 * IPsec whereas it should have. Now that it has been 748 * fragmented, re-inject it in ip_output so that IPsec 749 * processing can occur. 750 */ 751 if (natt_frag) { 752 error = ip_output(m, opt, ro, 753 flags | IP_RAWOUTPUT | IP_NOIPNEWID, 754 imo, so); 755 } else { 756 KASSERT((m->m_pkthdr.csum_flags & 757 (M_CSUM_UDPv4 | M_CSUM_TCPv4)) == 0); 758 error = ip_if_output(ifp, m, 759 (m->m_flags & M_MCAST) ? 760 sintocsa(rdst) : sintocsa(dst), rt); 761 } 762 } 763 if (error == 0) { 764 IP_STATINC(IP_STAT_FRAGMENTED); 765 } 766 done: 767 ia4_release(ia, &psref_ia); 768 if (ro == &iproute) { 769 rtcache_free(&iproute); 770 } 771 #ifdef IPSEC 772 if (sp) { 773 KEY_FREESP(&sp); 774 } 775 #endif 776 if (mifp != NULL) { 777 if_put(mifp, &psref); 778 } 779 if (bind_need_restore) 780 curlwp_bindx(bound); 781 return error; 782 bad: 783 m_freem(m); 784 goto done; 785 } 786 787 int 788 ip_fragment(struct mbuf *m, struct ifnet *ifp, u_long mtu) 789 { 790 struct ip *ip, *mhip; 791 struct mbuf *m0; 792 int len, hlen, off; 793 int mhlen, firstlen; 794 struct mbuf **mnext; 795 int sw_csum = m->m_pkthdr.csum_flags; 796 int fragments = 0; 797 int s; 798 int error = 0; 799 800 ip = mtod(m, struct ip *); 801 hlen = ip->ip_hl << 2; 802 if (ifp != NULL) 803 sw_csum &= ~ifp->if_csum_flags_tx; 804 805 len = (mtu - hlen) &~ 7; 806 if (len < 8) { 807 m_freem(m); 808 return (EMSGSIZE); 809 } 810 811 firstlen = len; 812 mnext = &m->m_nextpkt; 813 814 /* 815 * Loop through length of segment after first fragment, 816 * make new header and copy data of each part and link onto chain. 817 */ 818 m0 = m; 819 mhlen = sizeof (struct ip); 820 for (off = hlen + len; off < ntohs(ip->ip_len); off += len) { 821 MGETHDR(m, M_DONTWAIT, MT_HEADER); 822 if (m == 0) { 823 error = ENOBUFS; 824 IP_STATINC(IP_STAT_ODROPPED); 825 goto sendorfree; 826 } 827 MCLAIM(m, m0->m_owner); 828 *mnext = m; 829 mnext = &m->m_nextpkt; 830 m->m_data += max_linkhdr; 831 mhip = mtod(m, struct ip *); 832 *mhip = *ip; 833 /* we must inherit MCAST and BCAST flags */ 834 m->m_flags |= m0->m_flags & (M_MCAST|M_BCAST); 835 if (hlen > sizeof (struct ip)) { 836 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 837 mhip->ip_hl = mhlen >> 2; 838 } 839 m->m_len = mhlen; 840 mhip->ip_off = ((off - hlen) >> 3) + 841 (ntohs(ip->ip_off) & ~IP_MF); 842 if (ip->ip_off & htons(IP_MF)) 843 mhip->ip_off |= IP_MF; 844 if (off + len >= ntohs(ip->ip_len)) 845 len = ntohs(ip->ip_len) - off; 846 else 847 mhip->ip_off |= IP_MF; 848 HTONS(mhip->ip_off); 849 mhip->ip_len = htons((u_int16_t)(len + mhlen)); 850 m->m_next = m_copym(m0, off, len, M_DONTWAIT); 851 if (m->m_next == 0) { 852 error = ENOBUFS; /* ??? */ 853 IP_STATINC(IP_STAT_ODROPPED); 854 goto sendorfree; 855 } 856 m->m_pkthdr.len = mhlen + len; 857 m_reset_rcvif(m); 858 mhip->ip_sum = 0; 859 KASSERT((m->m_pkthdr.csum_flags & M_CSUM_IPv4) == 0); 860 if (sw_csum & M_CSUM_IPv4) { 861 mhip->ip_sum = in_cksum(m, mhlen); 862 } else { 863 /* 864 * checksum is hw-offloaded or not necessary. 865 */ 866 m->m_pkthdr.csum_flags |= 867 m0->m_pkthdr.csum_flags & M_CSUM_IPv4; 868 m->m_pkthdr.csum_data |= mhlen << 16; 869 KASSERT(!(ifp != NULL && 870 IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) || 871 (m->m_pkthdr.csum_flags & M_CSUM_IPv4) != 0); 872 } 873 IP_STATINC(IP_STAT_OFRAGMENTS); 874 fragments++; 875 } 876 /* 877 * Update first fragment by trimming what's been copied out 878 * and updating header, then send each fragment (in order). 879 */ 880 m = m0; 881 m_adj(m, hlen + firstlen - ntohs(ip->ip_len)); 882 m->m_pkthdr.len = hlen + firstlen; 883 ip->ip_len = htons((u_int16_t)m->m_pkthdr.len); 884 ip->ip_off |= htons(IP_MF); 885 ip->ip_sum = 0; 886 if (sw_csum & M_CSUM_IPv4) { 887 ip->ip_sum = in_cksum(m, hlen); 888 m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4; 889 } else { 890 /* 891 * checksum is hw-offloaded or not necessary. 892 */ 893 KASSERT(!(ifp != NULL && IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) || 894 (m->m_pkthdr.csum_flags & M_CSUM_IPv4) != 0); 895 KASSERT(M_CSUM_DATA_IPv4_IPHL(m->m_pkthdr.csum_data) >= 896 sizeof(struct ip)); 897 } 898 sendorfree: 899 /* 900 * If there is no room for all the fragments, don't queue 901 * any of them. 902 */ 903 if (ifp != NULL) { 904 s = splnet(); 905 if (ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len < fragments && 906 error == 0) { 907 error = ENOBUFS; 908 IP_STATINC(IP_STAT_ODROPPED); 909 IFQ_INC_DROPS(&ifp->if_snd); 910 } 911 splx(s); 912 } 913 if (error) { 914 for (m = m0; m; m = m0) { 915 m0 = m->m_nextpkt; 916 m->m_nextpkt = NULL; 917 m_freem(m); 918 } 919 } 920 return (error); 921 } 922 923 /* 924 * Process a delayed payload checksum calculation. 925 */ 926 void 927 in_delayed_cksum(struct mbuf *m) 928 { 929 struct ip *ip; 930 u_int16_t csum, offset; 931 932 ip = mtod(m, struct ip *); 933 offset = ip->ip_hl << 2; 934 csum = in4_cksum(m, 0, offset, ntohs(ip->ip_len) - offset); 935 if (csum == 0 && (m->m_pkthdr.csum_flags & M_CSUM_UDPv4) != 0) 936 csum = 0xffff; 937 938 offset += M_CSUM_DATA_IPv4_OFFSET(m->m_pkthdr.csum_data); 939 940 if ((offset + sizeof(u_int16_t)) > m->m_len) { 941 /* This happen when ip options were inserted 942 printf("in_delayed_cksum: pullup len %d off %d proto %d\n", 943 m->m_len, offset, ip->ip_p); 944 */ 945 m_copyback(m, offset, sizeof(csum), (void *) &csum); 946 } else 947 *(u_int16_t *)(mtod(m, char *) + offset) = csum; 948 } 949 950 /* 951 * Determine the maximum length of the options to be inserted; 952 * we would far rather allocate too much space rather than too little. 953 */ 954 955 u_int 956 ip_optlen(struct inpcb *inp) 957 { 958 struct mbuf *m = inp->inp_options; 959 960 if (m && m->m_len > offsetof(struct ipoption, ipopt_dst)) { 961 return (m->m_len - offsetof(struct ipoption, ipopt_dst)); 962 } 963 return 0; 964 } 965 966 /* 967 * Insert IP options into preformed packet. 968 * Adjust IP destination as required for IP source routing, 969 * as indicated by a non-zero in_addr at the start of the options. 970 */ 971 static struct mbuf * 972 ip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phlen) 973 { 974 struct ipoption *p = mtod(opt, struct ipoption *); 975 struct mbuf *n; 976 struct ip *ip = mtod(m, struct ip *); 977 unsigned optlen; 978 979 optlen = opt->m_len - sizeof(p->ipopt_dst); 980 if (optlen + ntohs(ip->ip_len) > IP_MAXPACKET) 981 return (m); /* XXX should fail */ 982 if (!in_nullhost(p->ipopt_dst)) 983 ip->ip_dst = p->ipopt_dst; 984 if (M_READONLY(m) || M_LEADINGSPACE(m) < optlen) { 985 MGETHDR(n, M_DONTWAIT, MT_HEADER); 986 if (n == 0) 987 return (m); 988 MCLAIM(n, m->m_owner); 989 M_MOVE_PKTHDR(n, m); 990 m->m_len -= sizeof(struct ip); 991 m->m_data += sizeof(struct ip); 992 n->m_next = m; 993 m = n; 994 m->m_len = optlen + sizeof(struct ip); 995 m->m_data += max_linkhdr; 996 bcopy((void *)ip, mtod(m, void *), sizeof(struct ip)); 997 } else { 998 m->m_data -= optlen; 999 m->m_len += optlen; 1000 memmove(mtod(m, void *), ip, sizeof(struct ip)); 1001 } 1002 m->m_pkthdr.len += optlen; 1003 ip = mtod(m, struct ip *); 1004 bcopy((void *)p->ipopt_list, (void *)(ip + 1), (unsigned)optlen); 1005 *phlen = sizeof(struct ip) + optlen; 1006 ip->ip_len = htons(ntohs(ip->ip_len) + optlen); 1007 return (m); 1008 } 1009 1010 /* 1011 * Copy options from ip to jp, 1012 * omitting those not copied during fragmentation. 1013 */ 1014 int 1015 ip_optcopy(struct ip *ip, struct ip *jp) 1016 { 1017 u_char *cp, *dp; 1018 int opt, optlen, cnt; 1019 1020 cp = (u_char *)(ip + 1); 1021 dp = (u_char *)(jp + 1); 1022 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 1023 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1024 opt = cp[0]; 1025 if (opt == IPOPT_EOL) 1026 break; 1027 if (opt == IPOPT_NOP) { 1028 /* Preserve for IP mcast tunnel's LSRR alignment. */ 1029 *dp++ = IPOPT_NOP; 1030 optlen = 1; 1031 continue; 1032 } 1033 1034 KASSERT(cnt >= IPOPT_OLEN + sizeof(*cp)); 1035 optlen = cp[IPOPT_OLEN]; 1036 KASSERT(optlen >= IPOPT_OLEN + sizeof(*cp) && optlen < cnt); 1037 1038 /* Invalid lengths should have been caught by ip_dooptions. */ 1039 if (optlen > cnt) 1040 optlen = cnt; 1041 if (IPOPT_COPIED(opt)) { 1042 bcopy((void *)cp, (void *)dp, (unsigned)optlen); 1043 dp += optlen; 1044 } 1045 } 1046 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 1047 *dp++ = IPOPT_EOL; 1048 return (optlen); 1049 } 1050 1051 /* 1052 * IP socket option processing. 1053 */ 1054 int 1055 ip_ctloutput(int op, struct socket *so, struct sockopt *sopt) 1056 { 1057 struct inpcb *inp = sotoinpcb(so); 1058 struct ip *ip = &inp->inp_ip; 1059 int inpflags = inp->inp_flags; 1060 int optval = 0, error = 0; 1061 1062 if (sopt->sopt_level != IPPROTO_IP) { 1063 if (sopt->sopt_level == SOL_SOCKET && sopt->sopt_name == SO_NOHEADER) 1064 return 0; 1065 return ENOPROTOOPT; 1066 } 1067 1068 switch (op) { 1069 case PRCO_SETOPT: 1070 switch (sopt->sopt_name) { 1071 case IP_OPTIONS: 1072 #ifdef notyet 1073 case IP_RETOPTS: 1074 #endif 1075 error = ip_pcbopts(inp, sopt); 1076 break; 1077 1078 case IP_TOS: 1079 case IP_TTL: 1080 case IP_MINTTL: 1081 case IP_PKTINFO: 1082 case IP_RECVOPTS: 1083 case IP_RECVRETOPTS: 1084 case IP_RECVDSTADDR: 1085 case IP_RECVIF: 1086 case IP_RECVPKTINFO: 1087 case IP_RECVTTL: 1088 error = sockopt_getint(sopt, &optval); 1089 if (error) 1090 break; 1091 1092 switch (sopt->sopt_name) { 1093 case IP_TOS: 1094 ip->ip_tos = optval; 1095 break; 1096 1097 case IP_TTL: 1098 ip->ip_ttl = optval; 1099 break; 1100 1101 case IP_MINTTL: 1102 if (optval > 0 && optval <= MAXTTL) 1103 inp->inp_ip_minttl = optval; 1104 else 1105 error = EINVAL; 1106 break; 1107 #define OPTSET(bit) \ 1108 if (optval) \ 1109 inpflags |= bit; \ 1110 else \ 1111 inpflags &= ~bit; 1112 1113 case IP_PKTINFO: 1114 OPTSET(INP_PKTINFO); 1115 break; 1116 1117 case IP_RECVOPTS: 1118 OPTSET(INP_RECVOPTS); 1119 break; 1120 1121 case IP_RECVPKTINFO: 1122 OPTSET(INP_RECVPKTINFO); 1123 break; 1124 1125 case IP_RECVRETOPTS: 1126 OPTSET(INP_RECVRETOPTS); 1127 break; 1128 1129 case IP_RECVDSTADDR: 1130 OPTSET(INP_RECVDSTADDR); 1131 break; 1132 1133 case IP_RECVIF: 1134 OPTSET(INP_RECVIF); 1135 break; 1136 1137 case IP_RECVTTL: 1138 OPTSET(INP_RECVTTL); 1139 break; 1140 } 1141 break; 1142 #undef OPTSET 1143 1144 case IP_MULTICAST_IF: 1145 case IP_MULTICAST_TTL: 1146 case IP_MULTICAST_LOOP: 1147 case IP_ADD_MEMBERSHIP: 1148 case IP_DROP_MEMBERSHIP: 1149 error = ip_setmoptions(&inp->inp_moptions, sopt); 1150 break; 1151 1152 case IP_PORTRANGE: 1153 error = sockopt_getint(sopt, &optval); 1154 if (error) 1155 break; 1156 1157 switch (optval) { 1158 case IP_PORTRANGE_DEFAULT: 1159 case IP_PORTRANGE_HIGH: 1160 inpflags &= ~(INP_LOWPORT); 1161 break; 1162 1163 case IP_PORTRANGE_LOW: 1164 inpflags |= INP_LOWPORT; 1165 break; 1166 1167 default: 1168 error = EINVAL; 1169 break; 1170 } 1171 break; 1172 1173 case IP_PORTALGO: 1174 error = sockopt_getint(sopt, &optval); 1175 if (error) 1176 break; 1177 1178 error = portalgo_algo_index_select( 1179 (struct inpcb_hdr *)inp, optval); 1180 break; 1181 1182 #if defined(IPSEC) 1183 case IP_IPSEC_POLICY: 1184 if (ipsec_enabled) { 1185 error = ipsec4_set_policy(inp, sopt->sopt_name, 1186 sopt->sopt_data, sopt->sopt_size, 1187 curlwp->l_cred); 1188 break; 1189 } 1190 /*FALLTHROUGH*/ 1191 #endif /* IPSEC */ 1192 1193 default: 1194 error = ENOPROTOOPT; 1195 break; 1196 } 1197 break; 1198 1199 case PRCO_GETOPT: 1200 switch (sopt->sopt_name) { 1201 case IP_OPTIONS: 1202 case IP_RETOPTS: { 1203 struct mbuf *mopts = inp->inp_options; 1204 1205 if (mopts) { 1206 struct mbuf *m; 1207 1208 m = m_copym(mopts, 0, M_COPYALL, M_DONTWAIT); 1209 if (m == NULL) { 1210 error = ENOBUFS; 1211 break; 1212 } 1213 error = sockopt_setmbuf(sopt, m); 1214 } 1215 break; 1216 } 1217 case IP_PKTINFO: 1218 case IP_TOS: 1219 case IP_TTL: 1220 case IP_MINTTL: 1221 case IP_RECVOPTS: 1222 case IP_RECVRETOPTS: 1223 case IP_RECVDSTADDR: 1224 case IP_RECVIF: 1225 case IP_RECVPKTINFO: 1226 case IP_RECVTTL: 1227 case IP_ERRORMTU: 1228 switch (sopt->sopt_name) { 1229 case IP_TOS: 1230 optval = ip->ip_tos; 1231 break; 1232 1233 case IP_TTL: 1234 optval = ip->ip_ttl; 1235 break; 1236 1237 case IP_MINTTL: 1238 optval = inp->inp_ip_minttl; 1239 break; 1240 1241 case IP_ERRORMTU: 1242 optval = inp->inp_errormtu; 1243 break; 1244 1245 #define OPTBIT(bit) (inpflags & bit ? 1 : 0) 1246 1247 case IP_PKTINFO: 1248 optval = OPTBIT(INP_PKTINFO); 1249 break; 1250 1251 case IP_RECVOPTS: 1252 optval = OPTBIT(INP_RECVOPTS); 1253 break; 1254 1255 case IP_RECVPKTINFO: 1256 optval = OPTBIT(INP_RECVPKTINFO); 1257 break; 1258 1259 case IP_RECVRETOPTS: 1260 optval = OPTBIT(INP_RECVRETOPTS); 1261 break; 1262 1263 case IP_RECVDSTADDR: 1264 optval = OPTBIT(INP_RECVDSTADDR); 1265 break; 1266 1267 case IP_RECVIF: 1268 optval = OPTBIT(INP_RECVIF); 1269 break; 1270 1271 case IP_RECVTTL: 1272 optval = OPTBIT(INP_RECVTTL); 1273 break; 1274 } 1275 error = sockopt_setint(sopt, optval); 1276 break; 1277 1278 #if 0 /* defined(IPSEC) */ 1279 case IP_IPSEC_POLICY: 1280 { 1281 struct mbuf *m = NULL; 1282 1283 /* XXX this will return EINVAL as sopt is empty */ 1284 error = ipsec4_get_policy(inp, sopt->sopt_data, 1285 sopt->sopt_size, &m); 1286 if (error == 0) 1287 error = sockopt_setmbuf(sopt, m); 1288 break; 1289 } 1290 #endif /*IPSEC*/ 1291 1292 case IP_MULTICAST_IF: 1293 case IP_MULTICAST_TTL: 1294 case IP_MULTICAST_LOOP: 1295 case IP_ADD_MEMBERSHIP: 1296 case IP_DROP_MEMBERSHIP: 1297 error = ip_getmoptions(inp->inp_moptions, sopt); 1298 break; 1299 1300 case IP_PORTRANGE: 1301 if (inpflags & INP_LOWPORT) 1302 optval = IP_PORTRANGE_LOW; 1303 else 1304 optval = IP_PORTRANGE_DEFAULT; 1305 error = sockopt_setint(sopt, optval); 1306 break; 1307 1308 case IP_PORTALGO: 1309 optval = inp->inp_portalgo; 1310 error = sockopt_setint(sopt, optval); 1311 break; 1312 1313 default: 1314 error = ENOPROTOOPT; 1315 break; 1316 } 1317 break; 1318 } 1319 1320 if (!error) { 1321 inp->inp_flags = inpflags; 1322 } 1323 return error; 1324 } 1325 1326 /* 1327 * Set up IP options in pcb for insertion in output packets. 1328 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1329 * with destination address if source routed. 1330 */ 1331 static int 1332 ip_pcbopts(struct inpcb *inp, const struct sockopt *sopt) 1333 { 1334 struct mbuf *m; 1335 const u_char *cp; 1336 u_char *dp; 1337 int cnt; 1338 1339 /* Turn off any old options. */ 1340 if (inp->inp_options) { 1341 m_free(inp->inp_options); 1342 } 1343 inp->inp_options = NULL; 1344 if ((cnt = sopt->sopt_size) == 0) { 1345 /* Only turning off any previous options. */ 1346 return 0; 1347 } 1348 cp = sopt->sopt_data; 1349 1350 #ifndef __vax__ 1351 if (cnt % sizeof(int32_t)) 1352 return (EINVAL); 1353 #endif 1354 1355 m = m_get(M_DONTWAIT, MT_SOOPTS); 1356 if (m == NULL) 1357 return (ENOBUFS); 1358 1359 dp = mtod(m, u_char *); 1360 memset(dp, 0, sizeof(struct in_addr)); 1361 dp += sizeof(struct in_addr); 1362 m->m_len = sizeof(struct in_addr); 1363 1364 /* 1365 * IP option list according to RFC791. Each option is of the form 1366 * 1367 * [optval] [olen] [(olen - 2) data bytes] 1368 * 1369 * We validate the list and copy options to an mbuf for prepending 1370 * to data packets. The IP first-hop destination address will be 1371 * stored before actual options and is zero if unset. 1372 */ 1373 while (cnt > 0) { 1374 uint8_t optval, olen, offset; 1375 1376 optval = cp[IPOPT_OPTVAL]; 1377 1378 if (optval == IPOPT_EOL || optval == IPOPT_NOP) { 1379 olen = 1; 1380 } else { 1381 if (cnt < IPOPT_OLEN + 1) 1382 goto bad; 1383 1384 olen = cp[IPOPT_OLEN]; 1385 if (olen < IPOPT_OLEN + 1 || olen > cnt) 1386 goto bad; 1387 } 1388 1389 if (optval == IPOPT_LSRR || optval == IPOPT_SSRR) { 1390 /* 1391 * user process specifies route as: 1392 * ->A->B->C->D 1393 * D must be our final destination (but we can't 1394 * check that since we may not have connected yet). 1395 * A is first hop destination, which doesn't appear in 1396 * actual IP option, but is stored before the options. 1397 */ 1398 if (olen < IPOPT_OFFSET + 1 + sizeof(struct in_addr)) 1399 goto bad; 1400 1401 offset = cp[IPOPT_OFFSET]; 1402 memcpy(mtod(m, u_char *), cp + IPOPT_OFFSET + 1, 1403 sizeof(struct in_addr)); 1404 1405 cp += sizeof(struct in_addr); 1406 cnt -= sizeof(struct in_addr); 1407 olen -= sizeof(struct in_addr); 1408 1409 if (m->m_len + olen > MAX_IPOPTLEN + sizeof(struct in_addr)) 1410 goto bad; 1411 1412 memcpy(dp, cp, olen); 1413 dp[IPOPT_OPTVAL] = optval; 1414 dp[IPOPT_OLEN] = olen; 1415 dp[IPOPT_OFFSET] = offset; 1416 break; 1417 } else { 1418 if (m->m_len + olen > MAX_IPOPTLEN + sizeof(struct in_addr)) 1419 goto bad; 1420 1421 memcpy(dp, cp, olen); 1422 break; 1423 } 1424 1425 dp += olen; 1426 m->m_len += olen; 1427 1428 if (optval == IPOPT_EOL) 1429 break; 1430 1431 cp += olen; 1432 cnt -= olen; 1433 } 1434 1435 inp->inp_options = m; 1436 return 0; 1437 bad: 1438 (void)m_free(m); 1439 return EINVAL; 1440 } 1441 1442 /* 1443 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. 1444 */ 1445 static struct ifnet * 1446 ip_multicast_if(struct in_addr *a, int *ifindexp) 1447 { 1448 int ifindex; 1449 struct ifnet *ifp = NULL; 1450 struct in_ifaddr *ia; 1451 1452 if (ifindexp) 1453 *ifindexp = 0; 1454 if (ntohl(a->s_addr) >> 24 == 0) { 1455 ifindex = ntohl(a->s_addr) & 0xffffff; 1456 ifp = if_byindex(ifindex); 1457 if (!ifp) 1458 return NULL; 1459 if (ifindexp) 1460 *ifindexp = ifindex; 1461 } else { 1462 LIST_FOREACH(ia, &IN_IFADDR_HASH(a->s_addr), ia_hash) { 1463 if (in_hosteq(ia->ia_addr.sin_addr, *a) && 1464 (ia->ia_ifp->if_flags & IFF_MULTICAST) != 0) { 1465 ifp = ia->ia_ifp; 1466 break; 1467 } 1468 } 1469 } 1470 return ifp; 1471 } 1472 1473 static int 1474 ip_getoptval(const struct sockopt *sopt, u_int8_t *val, u_int maxval) 1475 { 1476 u_int tval; 1477 u_char cval; 1478 int error; 1479 1480 if (sopt == NULL) 1481 return EINVAL; 1482 1483 switch (sopt->sopt_size) { 1484 case sizeof(u_char): 1485 error = sockopt_get(sopt, &cval, sizeof(u_char)); 1486 tval = cval; 1487 break; 1488 1489 case sizeof(u_int): 1490 error = sockopt_get(sopt, &tval, sizeof(u_int)); 1491 break; 1492 1493 default: 1494 error = EINVAL; 1495 } 1496 1497 if (error) 1498 return error; 1499 1500 if (tval > maxval) 1501 return EINVAL; 1502 1503 *val = tval; 1504 return 0; 1505 } 1506 1507 static int 1508 ip_get_membership(const struct sockopt *sopt, struct ifnet **ifp, 1509 struct in_addr *ia, bool add) 1510 { 1511 int error; 1512 struct ip_mreq mreq; 1513 1514 error = sockopt_get(sopt, &mreq, sizeof(mreq)); 1515 if (error) 1516 return error; 1517 1518 if (!IN_MULTICAST(mreq.imr_multiaddr.s_addr)) 1519 return EINVAL; 1520 1521 memcpy(ia, &mreq.imr_multiaddr, sizeof(*ia)); 1522 1523 if (in_nullhost(mreq.imr_interface)) { 1524 union { 1525 struct sockaddr dst; 1526 struct sockaddr_in dst4; 1527 } u; 1528 struct route ro; 1529 1530 if (!add) { 1531 *ifp = NULL; 1532 return 0; 1533 } 1534 /* 1535 * If no interface address was provided, use the interface of 1536 * the route to the given multicast address. 1537 */ 1538 struct rtentry *rt; 1539 memset(&ro, 0, sizeof(ro)); 1540 1541 sockaddr_in_init(&u.dst4, ia, 0); 1542 error = rtcache_setdst(&ro, &u.dst); 1543 if (error != 0) 1544 return error; 1545 *ifp = (rt = rtcache_init(&ro)) != NULL ? rt->rt_ifp : NULL; 1546 rtcache_free(&ro); 1547 } else { 1548 *ifp = ip_multicast_if(&mreq.imr_interface, NULL); 1549 if (!add && *ifp == NULL) 1550 return EADDRNOTAVAIL; 1551 } 1552 return 0; 1553 } 1554 1555 /* 1556 * Add a multicast group membership. 1557 * Group must be a valid IP multicast address. 1558 */ 1559 static int 1560 ip_add_membership(struct ip_moptions *imo, const struct sockopt *sopt) 1561 { 1562 struct ifnet *ifp = NULL; // XXX: gcc [ppc] 1563 struct in_addr ia; 1564 int i, error; 1565 1566 if (sopt->sopt_size == sizeof(struct ip_mreq)) 1567 error = ip_get_membership(sopt, &ifp, &ia, true); 1568 else 1569 #ifdef INET6 1570 error = ip6_get_membership(sopt, &ifp, &ia, sizeof(ia)); 1571 #else 1572 return EINVAL; 1573 #endif 1574 1575 if (error) 1576 return error; 1577 1578 /* 1579 * See if we found an interface, and confirm that it 1580 * supports multicast. 1581 */ 1582 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) 1583 return EADDRNOTAVAIL; 1584 1585 /* 1586 * See if the membership already exists or if all the 1587 * membership slots are full. 1588 */ 1589 for (i = 0; i < imo->imo_num_memberships; ++i) { 1590 if (imo->imo_membership[i]->inm_ifp == ifp && 1591 in_hosteq(imo->imo_membership[i]->inm_addr, ia)) 1592 break; 1593 } 1594 if (i < imo->imo_num_memberships) 1595 return EADDRINUSE; 1596 1597 if (i == IP_MAX_MEMBERSHIPS) 1598 return ETOOMANYREFS; 1599 1600 /* 1601 * Everything looks good; add a new record to the multicast 1602 * address list for the given interface. 1603 */ 1604 if ((imo->imo_membership[i] = in_addmulti(&ia, ifp)) == NULL) 1605 return ENOBUFS; 1606 1607 ++imo->imo_num_memberships; 1608 return 0; 1609 } 1610 1611 /* 1612 * Drop a multicast group membership. 1613 * Group must be a valid IP multicast address. 1614 */ 1615 static int 1616 ip_drop_membership(struct ip_moptions *imo, const struct sockopt *sopt) 1617 { 1618 struct in_addr ia = { .s_addr = 0 }; // XXX: gcc [ppc] 1619 struct ifnet *ifp = NULL; // XXX: gcc [ppc] 1620 int i, error; 1621 1622 if (sopt->sopt_size == sizeof(struct ip_mreq)) 1623 error = ip_get_membership(sopt, &ifp, &ia, false); 1624 else 1625 #ifdef INET6 1626 error = ip6_get_membership(sopt, &ifp, &ia, sizeof(ia)); 1627 #else 1628 return EINVAL; 1629 #endif 1630 1631 if (error) 1632 return error; 1633 1634 /* 1635 * Find the membership in the membership array. 1636 */ 1637 for (i = 0; i < imo->imo_num_memberships; ++i) { 1638 if ((ifp == NULL || 1639 imo->imo_membership[i]->inm_ifp == ifp) && 1640 in_hosteq(imo->imo_membership[i]->inm_addr, ia)) 1641 break; 1642 } 1643 if (i == imo->imo_num_memberships) 1644 return EADDRNOTAVAIL; 1645 1646 /* 1647 * Give up the multicast address record to which the 1648 * membership points. 1649 */ 1650 in_delmulti(imo->imo_membership[i]); 1651 1652 /* 1653 * Remove the gap in the membership array. 1654 */ 1655 for (++i; i < imo->imo_num_memberships; ++i) 1656 imo->imo_membership[i-1] = imo->imo_membership[i]; 1657 --imo->imo_num_memberships; 1658 return 0; 1659 } 1660 1661 /* 1662 * Set the IP multicast options in response to user setsockopt(). 1663 */ 1664 int 1665 ip_setmoptions(struct ip_moptions **pimo, const struct sockopt *sopt) 1666 { 1667 struct ip_moptions *imo = *pimo; 1668 struct in_addr addr; 1669 struct ifnet *ifp; 1670 int ifindex, error = 0; 1671 1672 if (!imo) { 1673 /* 1674 * No multicast option buffer attached to the pcb; 1675 * allocate one and initialize to default values. 1676 */ 1677 imo = kmem_intr_alloc(sizeof(*imo), KM_NOSLEEP); 1678 if (imo == NULL) 1679 return ENOBUFS; 1680 1681 imo->imo_multicast_if_index = 0; 1682 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1683 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1684 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1685 imo->imo_num_memberships = 0; 1686 *pimo = imo; 1687 } 1688 1689 switch (sopt->sopt_name) { 1690 case IP_MULTICAST_IF: 1691 /* 1692 * Select the interface for outgoing multicast packets. 1693 */ 1694 error = sockopt_get(sopt, &addr, sizeof(addr)); 1695 if (error) 1696 break; 1697 1698 /* 1699 * INADDR_ANY is used to remove a previous selection. 1700 * When no interface is selected, a default one is 1701 * chosen every time a multicast packet is sent. 1702 */ 1703 if (in_nullhost(addr)) { 1704 imo->imo_multicast_if_index = 0; 1705 break; 1706 } 1707 /* 1708 * The selected interface is identified by its local 1709 * IP address. Find the interface and confirm that 1710 * it supports multicasting. 1711 */ 1712 ifp = ip_multicast_if(&addr, &ifindex); 1713 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1714 error = EADDRNOTAVAIL; 1715 break; 1716 } 1717 imo->imo_multicast_if_index = ifp->if_index; 1718 if (ifindex) 1719 imo->imo_multicast_addr = addr; 1720 else 1721 imo->imo_multicast_addr.s_addr = INADDR_ANY; 1722 break; 1723 1724 case IP_MULTICAST_TTL: 1725 /* 1726 * Set the IP time-to-live for outgoing multicast packets. 1727 */ 1728 error = ip_getoptval(sopt, &imo->imo_multicast_ttl, MAXTTL); 1729 break; 1730 1731 case IP_MULTICAST_LOOP: 1732 /* 1733 * Set the loopback flag for outgoing multicast packets. 1734 * Must be zero or one. 1735 */ 1736 error = ip_getoptval(sopt, &imo->imo_multicast_loop, 1); 1737 break; 1738 1739 case IP_ADD_MEMBERSHIP: /* IPV6_JOIN_GROUP */ 1740 error = ip_add_membership(imo, sopt); 1741 break; 1742 1743 case IP_DROP_MEMBERSHIP: /* IPV6_LEAVE_GROUP */ 1744 error = ip_drop_membership(imo, sopt); 1745 break; 1746 1747 default: 1748 error = EOPNOTSUPP; 1749 break; 1750 } 1751 1752 /* 1753 * If all options have default values, no need to keep the mbuf. 1754 */ 1755 if (imo->imo_multicast_if_index == 0 && 1756 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 1757 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 1758 imo->imo_num_memberships == 0) { 1759 kmem_free(imo, sizeof(*imo)); 1760 *pimo = NULL; 1761 } 1762 1763 return error; 1764 } 1765 1766 /* 1767 * Return the IP multicast options in response to user getsockopt(). 1768 */ 1769 int 1770 ip_getmoptions(struct ip_moptions *imo, struct sockopt *sopt) 1771 { 1772 struct in_addr addr; 1773 uint8_t optval; 1774 int error = 0; 1775 1776 switch (sopt->sopt_name) { 1777 case IP_MULTICAST_IF: 1778 if (imo == NULL || imo->imo_multicast_if_index == 0) 1779 addr = zeroin_addr; 1780 else if (imo->imo_multicast_addr.s_addr) { 1781 /* return the value user has set */ 1782 addr = imo->imo_multicast_addr; 1783 } else { 1784 struct ifnet *ifp; 1785 struct in_ifaddr *ia = NULL; 1786 int s = pserialize_read_enter(); 1787 1788 ifp = if_byindex(imo->imo_multicast_if_index); 1789 if (ifp != NULL) { 1790 ia = in_get_ia_from_ifp(ifp); 1791 } 1792 addr = ia ? ia->ia_addr.sin_addr : zeroin_addr; 1793 pserialize_read_exit(s); 1794 } 1795 error = sockopt_set(sopt, &addr, sizeof(addr)); 1796 break; 1797 1798 case IP_MULTICAST_TTL: 1799 optval = imo ? imo->imo_multicast_ttl 1800 : IP_DEFAULT_MULTICAST_TTL; 1801 1802 error = sockopt_set(sopt, &optval, sizeof(optval)); 1803 break; 1804 1805 case IP_MULTICAST_LOOP: 1806 optval = imo ? imo->imo_multicast_loop 1807 : IP_DEFAULT_MULTICAST_LOOP; 1808 1809 error = sockopt_set(sopt, &optval, sizeof(optval)); 1810 break; 1811 1812 default: 1813 error = EOPNOTSUPP; 1814 } 1815 1816 return error; 1817 } 1818 1819 /* 1820 * Discard the IP multicast options. 1821 */ 1822 void 1823 ip_freemoptions(struct ip_moptions *imo) 1824 { 1825 int i; 1826 1827 if (imo != NULL) { 1828 for (i = 0; i < imo->imo_num_memberships; ++i) 1829 in_delmulti(imo->imo_membership[i]); 1830 kmem_free(imo, sizeof(*imo)); 1831 } 1832 } 1833 1834 /* 1835 * Routine called from ip_output() to loop back a copy of an IP multicast 1836 * packet to the input queue of a specified interface. Note that this 1837 * calls the output routine of the loopback "driver", but with an interface 1838 * pointer that might NOT be lo0ifp -- easier than replicating that code here. 1839 */ 1840 static void 1841 ip_mloopback(struct ifnet *ifp, struct mbuf *m, const struct sockaddr_in *dst) 1842 { 1843 struct ip *ip; 1844 struct mbuf *copym; 1845 1846 copym = m_copypacket(m, M_DONTWAIT); 1847 if (copym != NULL && 1848 (copym->m_flags & M_EXT || copym->m_len < sizeof(struct ip))) 1849 copym = m_pullup(copym, sizeof(struct ip)); 1850 if (copym == NULL) 1851 return; 1852 /* 1853 * We don't bother to fragment if the IP length is greater 1854 * than the interface's MTU. Can this possibly matter? 1855 */ 1856 ip = mtod(copym, struct ip *); 1857 1858 if (copym->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { 1859 in_delayed_cksum(copym); 1860 copym->m_pkthdr.csum_flags &= 1861 ~(M_CSUM_TCPv4|M_CSUM_UDPv4); 1862 } 1863 1864 ip->ip_sum = 0; 1865 ip->ip_sum = in_cksum(copym, ip->ip_hl << 2); 1866 #ifndef NET_MPSAFE 1867 KERNEL_LOCK(1, NULL); 1868 #endif 1869 (void)looutput(ifp, copym, sintocsa(dst), NULL); 1870 #ifndef NET_MPSAFE 1871 KERNEL_UNLOCK_ONE(NULL); 1872 #endif 1873 } 1874 1875 /* 1876 * Ensure sending address is valid. 1877 * Returns 0 on success, -1 if an error should be sent back or 1 1878 * if the packet could be dropped without error (protocol dependent). 1879 */ 1880 static int 1881 ip_ifaddrvalid(const struct in_ifaddr *ia) 1882 { 1883 1884 if (ia == NULL) 1885 return -1; 1886 1887 if (ia->ia_addr.sin_addr.s_addr == INADDR_ANY) 1888 return 0; 1889 1890 if (ia->ia4_flags & IN_IFF_DUPLICATED) 1891 return -1; 1892 else if (ia->ia4_flags & (IN_IFF_TENTATIVE | IN_IFF_DETACHED)) 1893 return 1; 1894 1895 return 0; 1896 } 1897
Indexes created Wed Oct 01 12:09:54 GMT 2025