ip_output.c revision 262747
1/*- 2 * Copyright (c) 1982, 1986, 1988, 1990, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)ip_output.c 8.3 (Berkeley) 1/21/94 30 */ 31 32#include <sys/cdefs.h> 33__FBSDID("$FreeBSD: head/sys/netinet/ip_output.c 262747 2014-03-04 19:49:41Z glebius $"); 34 35#include "opt_inet.h" 36#include "opt_ipfw.h" 37#include "opt_ipsec.h" 38#include "opt_mbuf_stress_test.h" 39#include "opt_mpath.h" 40#include "opt_route.h" 41#include "opt_sctp.h" 42 43#include <sys/param.h> 44#include <sys/systm.h> 45#include <sys/kernel.h> 46#include <sys/malloc.h> 47#include <sys/mbuf.h> 48#include <sys/priv.h> 49#include <sys/proc.h> 50#include <sys/protosw.h> 51#include <sys/sdt.h> 52#include <sys/socket.h> 53#include <sys/socketvar.h> 54#include <sys/sysctl.h> 55#include <sys/ucred.h> 56 57#include <net/if.h> 58#include <net/if_var.h> 59#include <net/if_llatbl.h> 60#include <net/netisr.h> 61#include <net/pfil.h> 62#include <net/route.h> 63#include <net/flowtable.h> 64#ifdef RADIX_MPATH 65#include <net/radix_mpath.h> 66#endif 67#include <net/vnet.h> 68 69#include <netinet/in.h> 70#include <netinet/in_kdtrace.h> 71#include <netinet/in_systm.h> 72#include <netinet/ip.h> 73#include <netinet/in_pcb.h> 74#include <netinet/in_var.h> 75#include <netinet/ip_var.h> 76#include <netinet/ip_options.h> 77#ifdef SCTP 78#include <netinet/sctp.h> 79#include <netinet/sctp_crc32.h> 80#endif 81 82#ifdef IPSEC 83#include <netinet/ip_ipsec.h> 84#include <netipsec/ipsec.h> 85#endif /* IPSEC*/ 86 87#include <machine/in_cksum.h> 88 89#include <security/mac/mac_framework.h> 90 91VNET_DEFINE(u_short, ip_id); 92 93#ifdef MBUF_STRESS_TEST 94static int mbuf_frag_size = 0; 95SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW, 96 &mbuf_frag_size, 0, "Fragment outgoing mbufs to this size"); 97#endif 98 99static void ip_mloopback 100 (struct ifnet *, struct mbuf *, struct sockaddr_in *, int); 101 102 103extern int in_mcast_loop; 104extern struct protosw inetsw[]; 105 106/* 107 * IP output. The packet in mbuf chain m contains a skeletal IP 108 * header (with len, off, ttl, proto, tos, src, dst). 109 * The mbuf chain containing the packet will be freed. 110 * The mbuf opt, if present, will not be freed. 111 * If route ro is present and has ro_rt initialized, route lookup would be 112 * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL, 113 * then result of route lookup is stored in ro->ro_rt. 114 * 115 * In the IP forwarding case, the packet will arrive with options already 116 * inserted, so must have a NULL opt pointer. 117 */ 118int 119ip_output(struct mbuf *m, struct mbuf *opt, struct route *ro, int flags, 120 struct ip_moptions *imo, struct inpcb *inp) 121{ 122 struct ip *ip; 123 struct ifnet *ifp = NULL; /* keep compiler happy */ 124 struct mbuf *m0; 125 int hlen = sizeof (struct ip); 126 int mtu; 127 int error = 0; 128 struct sockaddr_in *dst; 129 const struct sockaddr_in *gw; 130 struct in_ifaddr *ia; 131 int isbroadcast; 132 uint16_t ip_len, ip_off; 133 struct route iproute; 134 struct rtentry *rte; /* cache for ro->ro_rt */ 135 struct in_addr odst; 136 struct m_tag *fwd_tag = NULL; 137#ifdef IPSEC 138 int no_route_but_check_spd = 0; 139#endif 140 M_ASSERTPKTHDR(m); 141 142 if (inp != NULL) { 143 INP_LOCK_ASSERT(inp); 144 M_SETFIB(m, inp->inp_inc.inc_fibnum); 145 if (inp->inp_flags & (INP_HW_FLOWID|INP_SW_FLOWID)) { 146 m->m_pkthdr.flowid = inp->inp_flowid; 147 m->m_flags |= M_FLOWID; 148 } 149 } 150 151 if (ro == NULL) { 152 ro = &iproute; 153 bzero(ro, sizeof (*ro)); 154 } 155 156#ifdef FLOWTABLE 157 if (ro->ro_rt == NULL) 158 (void )flowtable_lookup(AF_INET, m, ro); 159#endif 160 161 if (opt) { 162 int len = 0; 163 m = ip_insertoptions(m, opt, &len); 164 if (len != 0) 165 hlen = len; /* ip->ip_hl is updated above */ 166 } 167 ip = mtod(m, struct ip *); 168 ip_len = ntohs(ip->ip_len); 169 ip_off = ntohs(ip->ip_off); 170 171 /* 172 * Fill in IP header. If we are not allowing fragmentation, 173 * then the ip_id field is meaningless, but we don't set it 174 * to zero. Doing so causes various problems when devices along 175 * the path (routers, load balancers, firewalls, etc.) illegally 176 * disable DF on our packet. Note that a 16-bit counter 177 * will wrap around in less than 10 seconds at 100 Mbit/s on a 178 * medium with MTU 1500. See Steven M. Bellovin, "A Technique 179 * for Counting NATted Hosts", Proc. IMW'02, available at 180 * <http://www.cs.columbia.edu/~smb/papers/fnat.pdf>. 181 */ 182 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 183 ip->ip_v = IPVERSION; 184 ip->ip_hl = hlen >> 2; 185 ip->ip_id = ip_newid(); 186 IPSTAT_INC(ips_localout); 187 } else { 188 /* Header already set, fetch hlen from there */ 189 hlen = ip->ip_hl << 2; 190 } 191 192 /* 193 * dst/gw handling: 194 * 195 * dst can be rewritten but always points to &ro->ro_dst. 196 * gw is readonly but can point either to dst OR rt_gateway, 197 * therefore we need restore gw if we're redoing lookup. 198 */ 199 gw = dst = (struct sockaddr_in *)&ro->ro_dst; 200again: 201 ia = NULL; 202 /* 203 * If there is a cached route, check that it is to the same 204 * destination and is still up. If not, free it and try again. 205 * The address family should also be checked in case of sharing 206 * the cache with IPv6. 207 */ 208 rte = ro->ro_rt; 209 if (rte && ((rte->rt_flags & RTF_UP) == 0 || 210 rte->rt_ifp == NULL || 211 !RT_LINK_IS_UP(rte->rt_ifp) || 212 dst->sin_family != AF_INET || 213 dst->sin_addr.s_addr != ip->ip_dst.s_addr)) { 214 RO_RTFREE(ro); 215 ro->ro_lle = NULL; 216 rte = NULL; 217 gw = dst; 218 } 219 if (rte == NULL && fwd_tag == NULL) { 220 bzero(dst, sizeof(*dst)); 221 dst->sin_family = AF_INET; 222 dst->sin_len = sizeof(*dst); 223 dst->sin_addr = ip->ip_dst; 224 } 225 /* 226 * If routing to interface only, short circuit routing lookup. 227 * The use of an all-ones broadcast address implies this; an 228 * interface is specified by the broadcast address of an interface, 229 * or the destination address of a ptp interface. 230 */ 231 if (flags & IP_SENDONES) { 232 if ((ia = ifatoia(ifa_ifwithbroadaddr(sintosa(dst)))) == NULL && 233 (ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL) { 234 IPSTAT_INC(ips_noroute); 235 error = ENETUNREACH; 236 goto bad; 237 } 238 ip->ip_dst.s_addr = INADDR_BROADCAST; 239 dst->sin_addr = ip->ip_dst; 240 ifp = ia->ia_ifp; 241 ip->ip_ttl = 1; 242 isbroadcast = 1; 243 } else if (flags & IP_ROUTETOIF) { 244 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL && 245 (ia = ifatoia(ifa_ifwithnet(sintosa(dst), 0))) == NULL) { 246 IPSTAT_INC(ips_noroute); 247 error = ENETUNREACH; 248 goto bad; 249 } 250 ifp = ia->ia_ifp; 251 ip->ip_ttl = 1; 252 isbroadcast = in_broadcast(dst->sin_addr, ifp); 253 } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) && 254 imo != NULL && imo->imo_multicast_ifp != NULL) { 255 /* 256 * Bypass the normal routing lookup for multicast 257 * packets if the interface is specified. 258 */ 259 ifp = imo->imo_multicast_ifp; 260 IFP_TO_IA(ifp, ia); 261 isbroadcast = 0; /* fool gcc */ 262 } else { 263 /* 264 * We want to do any cloning requested by the link layer, 265 * as this is probably required in all cases for correct 266 * operation (as it is for ARP). 267 */ 268 if (rte == NULL) { 269#ifdef RADIX_MPATH 270 rtalloc_mpath_fib(ro, 271 ntohl(ip->ip_src.s_addr ^ ip->ip_dst.s_addr), 272 inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m)); 273#else 274 in_rtalloc_ign(ro, 0, 275 inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m)); 276#endif 277 rte = ro->ro_rt; 278 } 279 if (rte == NULL || 280 rte->rt_ifp == NULL || 281 !RT_LINK_IS_UP(rte->rt_ifp)) { 282#ifdef IPSEC 283 /* 284 * There is no route for this packet, but it is 285 * possible that a matching SPD entry exists. 286 */ 287 no_route_but_check_spd = 1; 288 mtu = 0; /* Silence GCC warning. */ 289 goto sendit; 290#endif 291 IPSTAT_INC(ips_noroute); 292 error = EHOSTUNREACH; 293 goto bad; 294 } 295 ia = ifatoia(rte->rt_ifa); 296 ifp = rte->rt_ifp; 297 rte->rt_rmx.rmx_pksent++; 298 if (rte->rt_flags & RTF_GATEWAY) 299 gw = (struct sockaddr_in *)rte->rt_gateway; 300 if (rte->rt_flags & RTF_HOST) 301 isbroadcast = (rte->rt_flags & RTF_BROADCAST); 302 else 303 isbroadcast = in_broadcast(gw->sin_addr, ifp); 304 } 305 /* 306 * Calculate MTU. If we have a route that is up, use that, 307 * otherwise use the interface's MTU. 308 */ 309 if (rte != NULL && (rte->rt_flags & (RTF_UP|RTF_HOST))) { 310 /* 311 * This case can happen if the user changed the MTU 312 * of an interface after enabling IP on it. Because 313 * most netifs don't keep track of routes pointing to 314 * them, there is no way for one to update all its 315 * routes when the MTU is changed. 316 */ 317 if (rte->rt_rmx.rmx_mtu > ifp->if_mtu) 318 rte->rt_rmx.rmx_mtu = ifp->if_mtu; 319 mtu = rte->rt_rmx.rmx_mtu; 320 } else { 321 mtu = ifp->if_mtu; 322 } 323 /* Catch a possible divide by zero later. */ 324 KASSERT(mtu > 0, ("%s: mtu %d <= 0, rte=%p (rt_flags=0x%08x) ifp=%p", 325 __func__, mtu, rte, (rte != NULL) ? rte->rt_flags : 0, ifp)); 326 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) { 327 m->m_flags |= M_MCAST; 328 /* 329 * IP destination address is multicast. Make sure "gw" 330 * still points to the address in "ro". (It may have been 331 * changed to point to a gateway address, above.) 332 */ 333 gw = dst; 334 /* 335 * See if the caller provided any multicast options 336 */ 337 if (imo != NULL) { 338 ip->ip_ttl = imo->imo_multicast_ttl; 339 if (imo->imo_multicast_vif != -1) 340 ip->ip_src.s_addr = 341 ip_mcast_src ? 342 ip_mcast_src(imo->imo_multicast_vif) : 343 INADDR_ANY; 344 } else 345 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 346 /* 347 * Confirm that the outgoing interface supports multicast. 348 */ 349 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) { 350 if ((ifp->if_flags & IFF_MULTICAST) == 0) { 351 IPSTAT_INC(ips_noroute); 352 error = ENETUNREACH; 353 goto bad; 354 } 355 } 356 /* 357 * If source address not specified yet, use address 358 * of outgoing interface. 359 */ 360 if (ip->ip_src.s_addr == INADDR_ANY) { 361 /* Interface may have no addresses. */ 362 if (ia != NULL) 363 ip->ip_src = IA_SIN(ia)->sin_addr; 364 } 365 366 if ((imo == NULL && in_mcast_loop) || 367 (imo && imo->imo_multicast_loop)) { 368 /* 369 * Loop back multicast datagram if not expressly 370 * forbidden to do so, even if we are not a member 371 * of the group; ip_input() will filter it later, 372 * thus deferring a hash lookup and mutex acquisition 373 * at the expense of a cheap copy using m_copym(). 374 */ 375 ip_mloopback(ifp, m, dst, hlen); 376 } else { 377 /* 378 * If we are acting as a multicast router, perform 379 * multicast forwarding as if the packet had just 380 * arrived on the interface to which we are about 381 * to send. The multicast forwarding function 382 * recursively calls this function, using the 383 * IP_FORWARDING flag to prevent infinite recursion. 384 * 385 * Multicasts that are looped back by ip_mloopback(), 386 * above, will be forwarded by the ip_input() routine, 387 * if necessary. 388 */ 389 if (V_ip_mrouter && (flags & IP_FORWARDING) == 0) { 390 /* 391 * If rsvp daemon is not running, do not 392 * set ip_moptions. This ensures that the packet 393 * is multicast and not just sent down one link 394 * as prescribed by rsvpd. 395 */ 396 if (!V_rsvp_on) 397 imo = NULL; 398 if (ip_mforward && 399 ip_mforward(ip, ifp, m, imo) != 0) { 400 m_freem(m); 401 goto done; 402 } 403 } 404 } 405 406 /* 407 * Multicasts with a time-to-live of zero may be looped- 408 * back, above, but must not be transmitted on a network. 409 * Also, multicasts addressed to the loopback interface 410 * are not sent -- the above call to ip_mloopback() will 411 * loop back a copy. ip_input() will drop the copy if 412 * this host does not belong to the destination group on 413 * the loopback interface. 414 */ 415 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) { 416 m_freem(m); 417 goto done; 418 } 419 420 goto sendit; 421 } 422 423 /* 424 * If the source address is not specified yet, use the address 425 * of the outoing interface. 426 */ 427 if (ip->ip_src.s_addr == INADDR_ANY) { 428 /* Interface may have no addresses. */ 429 if (ia != NULL) { 430 ip->ip_src = IA_SIN(ia)->sin_addr; 431 } 432 } 433 434 /* 435 * Both in the SMP world, pre-emption world if_transmit() world, 436 * the following code doesn't really function as intended any further. 437 * 438 * + There can and will be multiple CPUs running this code path 439 * in parallel, and we do no lock holding when checking the 440 * queue depth; 441 * + And since other threads can be running concurrently, even if 442 * we do pass this check, another thread may queue some frames 443 * before this thread does and it will end up partially or fully 444 * failing to send anyway; 445 * + if_transmit() based drivers don't necessarily set ifq_len 446 * at all. 447 * 448 * This should be replaced with a method of pushing an entire list 449 * of fragment frames to the driver and have the driver decide 450 * whether it can queue or not queue the entire set. 451 */ 452#if 0 453 /* 454 * Verify that we have any chance at all of being able to queue the 455 * packet or packet fragments, unless ALTQ is enabled on the given 456 * interface in which case packetdrop should be done by queueing. 457 */ 458 n = ip_len / mtu + 1; /* how many fragments ? */ 459 if ( 460#ifdef ALTQ 461 (!ALTQ_IS_ENABLED(&ifp->if_snd)) && 462#endif /* ALTQ */ 463 (ifp->if_snd.ifq_len + n) >= ifp->if_snd.ifq_maxlen ) { 464 error = ENOBUFS; 465 IPSTAT_INC(ips_odropped); 466 ifp->if_snd.ifq_drops += n; 467 goto bad; 468 } 469#endif 470 471 /* 472 * Look for broadcast address and 473 * verify user is allowed to send 474 * such a packet. 475 */ 476 if (isbroadcast) { 477 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 478 error = EADDRNOTAVAIL; 479 goto bad; 480 } 481 if ((flags & IP_ALLOWBROADCAST) == 0) { 482 error = EACCES; 483 goto bad; 484 } 485 /* don't allow broadcast messages to be fragmented */ 486 if (ip_len > mtu) { 487 error = EMSGSIZE; 488 goto bad; 489 } 490 m->m_flags |= M_BCAST; 491 } else { 492 m->m_flags &= ~M_BCAST; 493 } 494 495sendit: 496#ifdef IPSEC 497 switch(ip_ipsec_output(&m, inp, &flags, &error)) { 498 case 1: 499 goto bad; 500 case -1: 501 goto done; 502 case 0: 503 default: 504 break; /* Continue with packet processing. */ 505 } 506 /* 507 * Check if there was a route for this packet; return error if not. 508 */ 509 if (no_route_but_check_spd) { 510 IPSTAT_INC(ips_noroute); 511 error = EHOSTUNREACH; 512 goto bad; 513 } 514 /* Update variables that are affected by ipsec4_output(). */ 515 ip = mtod(m, struct ip *); 516 hlen = ip->ip_hl << 2; 517#endif /* IPSEC */ 518 519 /* Jump over all PFIL processing if hooks are not active. */ 520 if (!PFIL_HOOKED(&V_inet_pfil_hook)) 521 goto passout; 522 523 /* Run through list of hooks for output packets. */ 524 odst.s_addr = ip->ip_dst.s_addr; 525 error = pfil_run_hooks(&V_inet_pfil_hook, &m, ifp, PFIL_OUT, inp); 526 if (error != 0 || m == NULL) 527 goto done; 528 529 ip = mtod(m, struct ip *); 530 531 /* See if destination IP address was changed by packet filter. */ 532 if (odst.s_addr != ip->ip_dst.s_addr) { 533 m->m_flags |= M_SKIP_FIREWALL; 534 /* If destination is now ourself drop to ip_input(). */ 535 if (in_localip(ip->ip_dst)) { 536 m->m_flags |= M_FASTFWD_OURS; 537 if (m->m_pkthdr.rcvif == NULL) 538 m->m_pkthdr.rcvif = V_loif; 539 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 540 m->m_pkthdr.csum_flags |= 541 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 542 m->m_pkthdr.csum_data = 0xffff; 543 } 544 m->m_pkthdr.csum_flags |= 545 CSUM_IP_CHECKED | CSUM_IP_VALID; 546#ifdef SCTP 547 if (m->m_pkthdr.csum_flags & CSUM_SCTP) 548 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID; 549#endif 550 error = netisr_queue(NETISR_IP, m); 551 goto done; 552 } else 553 goto again; /* Redo the routing table lookup. */ 554 } 555 556 /* See if local, if yes, send it to netisr with IP_FASTFWD_OURS. */ 557 if (m->m_flags & M_FASTFWD_OURS) { 558 if (m->m_pkthdr.rcvif == NULL) 559 m->m_pkthdr.rcvif = V_loif; 560 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 561 m->m_pkthdr.csum_flags |= 562 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 563 m->m_pkthdr.csum_data = 0xffff; 564 } 565#ifdef SCTP 566 if (m->m_pkthdr.csum_flags & CSUM_SCTP) 567 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID; 568#endif 569 m->m_pkthdr.csum_flags |= 570 CSUM_IP_CHECKED | CSUM_IP_VALID; 571 572 error = netisr_queue(NETISR_IP, m); 573 goto done; 574 } 575 /* Or forward to some other address? */ 576 if ((m->m_flags & M_IP_NEXTHOP) && 577 (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) { 578 bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in)); 579 m->m_flags |= M_SKIP_FIREWALL; 580 m->m_flags &= ~M_IP_NEXTHOP; 581 m_tag_delete(m, fwd_tag); 582 goto again; 583 } 584 585passout: 586 /* 127/8 must not appear on wire - RFC1122. */ 587 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET || 588 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) { 589 if ((ifp->if_flags & IFF_LOOPBACK) == 0) { 590 IPSTAT_INC(ips_badaddr); 591 error = EADDRNOTAVAIL; 592 goto bad; 593 } 594 } 595 596 m->m_pkthdr.csum_flags |= CSUM_IP; 597 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA & ~ifp->if_hwassist) { 598 in_delayed_cksum(m); 599 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 600 } 601#ifdef SCTP 602 if (m->m_pkthdr.csum_flags & CSUM_SCTP & ~ifp->if_hwassist) { 603 sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2)); 604 m->m_pkthdr.csum_flags &= ~CSUM_SCTP; 605 } 606#endif 607 608 /* 609 * If small enough for interface, or the interface will take 610 * care of the fragmentation for us, we can just send directly. 611 */ 612 if (ip_len <= mtu || 613 (m->m_pkthdr.csum_flags & ifp->if_hwassist & CSUM_TSO) != 0 || 614 ((ip_off & IP_DF) == 0 && (ifp->if_hwassist & CSUM_FRAGMENT))) { 615 ip->ip_sum = 0; 616 if (m->m_pkthdr.csum_flags & CSUM_IP & ~ifp->if_hwassist) { 617 ip->ip_sum = in_cksum(m, hlen); 618 m->m_pkthdr.csum_flags &= ~CSUM_IP; 619 } 620 621 /* 622 * Record statistics for this interface address. 623 * With CSUM_TSO the byte/packet count will be slightly 624 * incorrect because we count the IP+TCP headers only 625 * once instead of for every generated packet. 626 */ 627 if (!(flags & IP_FORWARDING) && ia) { 628 if (m->m_pkthdr.csum_flags & CSUM_TSO) 629 counter_u64_add(ia->ia_ifa.ifa_opackets, 630 m->m_pkthdr.len / m->m_pkthdr.tso_segsz); 631 else 632 counter_u64_add(ia->ia_ifa.ifa_opackets, 1); 633 634 counter_u64_add(ia->ia_ifa.ifa_obytes, m->m_pkthdr.len); 635 } 636#ifdef MBUF_STRESS_TEST 637 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size) 638 m = m_fragment(m, M_NOWAIT, mbuf_frag_size); 639#endif 640 /* 641 * Reset layer specific mbuf flags 642 * to avoid confusing lower layers. 643 */ 644 m_clrprotoflags(m); 645 IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL); 646 error = (*ifp->if_output)(ifp, m, 647 (const struct sockaddr *)gw, ro); 648 goto done; 649 } 650 651 /* Balk when DF bit is set or the interface didn't support TSO. */ 652 if ((ip_off & IP_DF) || (m->m_pkthdr.csum_flags & CSUM_TSO)) { 653 error = EMSGSIZE; 654 IPSTAT_INC(ips_cantfrag); 655 goto bad; 656 } 657 658 /* 659 * Too large for interface; fragment if possible. If successful, 660 * on return, m will point to a list of packets to be sent. 661 */ 662 error = ip_fragment(ip, &m, mtu, ifp->if_hwassist); 663 if (error) 664 goto bad; 665 for (; m; m = m0) { 666 m0 = m->m_nextpkt; 667 m->m_nextpkt = 0; 668 if (error == 0) { 669 /* Record statistics for this interface address. */ 670 if (ia != NULL) { 671 counter_u64_add(ia->ia_ifa.ifa_opackets, 1); 672 counter_u64_add(ia->ia_ifa.ifa_obytes, 673 m->m_pkthdr.len); 674 } 675 /* 676 * Reset layer specific mbuf flags 677 * to avoid confusing upper layers. 678 */ 679 m_clrprotoflags(m); 680 681 IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL); 682 error = (*ifp->if_output)(ifp, m, 683 (const struct sockaddr *)gw, ro); 684 } else 685 m_freem(m); 686 } 687 688 if (error == 0) 689 IPSTAT_INC(ips_fragmented); 690 691done: 692 if (ro == &iproute) 693 RO_RTFREE(ro); 694 return (error); 695bad: 696 m_freem(m); 697 goto done; 698} 699 700/* 701 * Create a chain of fragments which fit the given mtu. m_frag points to the 702 * mbuf to be fragmented; on return it points to the chain with the fragments. 703 * Return 0 if no error. If error, m_frag may contain a partially built 704 * chain of fragments that should be freed by the caller. 705 * 706 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist) 707 */ 708int 709ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu, 710 u_long if_hwassist_flags) 711{ 712 int error = 0; 713 int hlen = ip->ip_hl << 2; 714 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */ 715 int off; 716 struct mbuf *m0 = *m_frag; /* the original packet */ 717 int firstlen; 718 struct mbuf **mnext; 719 int nfrags; 720 uint16_t ip_len, ip_off; 721 722 ip_len = ntohs(ip->ip_len); 723 ip_off = ntohs(ip->ip_off); 724 725 if (ip_off & IP_DF) { /* Fragmentation not allowed */ 726 IPSTAT_INC(ips_cantfrag); 727 return EMSGSIZE; 728 } 729 730 /* 731 * Must be able to put at least 8 bytes per fragment. 732 */ 733 if (len < 8) 734 return EMSGSIZE; 735 736 /* 737 * If the interface will not calculate checksums on 738 * fragmented packets, then do it here. 739 */ 740 if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 741 in_delayed_cksum(m0); 742 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 743 } 744#ifdef SCTP 745 if (m0->m_pkthdr.csum_flags & CSUM_SCTP) { 746 sctp_delayed_cksum(m0, hlen); 747 m0->m_pkthdr.csum_flags &= ~CSUM_SCTP; 748 } 749#endif 750 if (len > PAGE_SIZE) { 751 /* 752 * Fragment large datagrams such that each segment 753 * contains a multiple of PAGE_SIZE amount of data, 754 * plus headers. This enables a receiver to perform 755 * page-flipping zero-copy optimizations. 756 * 757 * XXX When does this help given that sender and receiver 758 * could have different page sizes, and also mtu could 759 * be less than the receiver's page size ? 760 */ 761 int newlen; 762 struct mbuf *m; 763 764 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next) 765 off += m->m_len; 766 767 /* 768 * firstlen (off - hlen) must be aligned on an 769 * 8-byte boundary 770 */ 771 if (off < hlen) 772 goto smart_frag_failure; 773 off = ((off - hlen) & ~7) + hlen; 774 newlen = (~PAGE_MASK) & mtu; 775 if ((newlen + sizeof (struct ip)) > mtu) { 776 /* we failed, go back the default */ 777smart_frag_failure: 778 newlen = len; 779 off = hlen + len; 780 } 781 len = newlen; 782 783 } else { 784 off = hlen + len; 785 } 786 787 firstlen = off - hlen; 788 mnext = &m0->m_nextpkt; /* pointer to next packet */ 789 790 /* 791 * Loop through length of segment after first fragment, 792 * make new header and copy data of each part and link onto chain. 793 * Here, m0 is the original packet, m is the fragment being created. 794 * The fragments are linked off the m_nextpkt of the original 795 * packet, which after processing serves as the first fragment. 796 */ 797 for (nfrags = 1; off < ip_len; off += len, nfrags++) { 798 struct ip *mhip; /* ip header on the fragment */ 799 struct mbuf *m; 800 int mhlen = sizeof (struct ip); 801 802 m = m_gethdr(M_NOWAIT, MT_DATA); 803 if (m == NULL) { 804 error = ENOBUFS; 805 IPSTAT_INC(ips_odropped); 806 goto done; 807 } 808 m->m_flags |= (m0->m_flags & M_MCAST); 809 /* 810 * In the first mbuf, leave room for the link header, then 811 * copy the original IP header including options. The payload 812 * goes into an additional mbuf chain returned by m_copym(). 813 */ 814 m->m_data += max_linkhdr; 815 mhip = mtod(m, struct ip *); 816 *mhip = *ip; 817 if (hlen > sizeof (struct ip)) { 818 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 819 mhip->ip_v = IPVERSION; 820 mhip->ip_hl = mhlen >> 2; 821 } 822 m->m_len = mhlen; 823 /* XXX do we need to add ip_off below ? */ 824 mhip->ip_off = ((off - hlen) >> 3) + ip_off; 825 if (off + len >= ip_len) 826 len = ip_len - off; 827 else 828 mhip->ip_off |= IP_MF; 829 mhip->ip_len = htons((u_short)(len + mhlen)); 830 m->m_next = m_copym(m0, off, len, M_NOWAIT); 831 if (m->m_next == NULL) { /* copy failed */ 832 m_free(m); 833 error = ENOBUFS; /* ??? */ 834 IPSTAT_INC(ips_odropped); 835 goto done; 836 } 837 m->m_pkthdr.len = mhlen + len; 838 m->m_pkthdr.rcvif = NULL; 839#ifdef MAC 840 mac_netinet_fragment(m0, m); 841#endif 842 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags; 843 mhip->ip_off = htons(mhip->ip_off); 844 mhip->ip_sum = 0; 845 if (m->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) { 846 mhip->ip_sum = in_cksum(m, mhlen); 847 m->m_pkthdr.csum_flags &= ~CSUM_IP; 848 } 849 *mnext = m; 850 mnext = &m->m_nextpkt; 851 } 852 IPSTAT_ADD(ips_ofragments, nfrags); 853 854 /* 855 * Update first fragment by trimming what's been copied out 856 * and updating header. 857 */ 858 m_adj(m0, hlen + firstlen - ip_len); 859 m0->m_pkthdr.len = hlen + firstlen; 860 ip->ip_len = htons((u_short)m0->m_pkthdr.len); 861 ip->ip_off = htons(ip_off | IP_MF); 862 ip->ip_sum = 0; 863 if (m0->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) { 864 ip->ip_sum = in_cksum(m0, hlen); 865 m0->m_pkthdr.csum_flags &= ~CSUM_IP; 866 } 867 868done: 869 *m_frag = m0; 870 return error; 871} 872 873void 874in_delayed_cksum(struct mbuf *m) 875{ 876 struct ip *ip; 877 uint16_t csum, offset, ip_len; 878 879 ip = mtod(m, struct ip *); 880 offset = ip->ip_hl << 2 ; 881 ip_len = ntohs(ip->ip_len); 882 csum = in_cksum_skip(m, ip_len, offset); 883 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0) 884 csum = 0xffff; 885 offset += m->m_pkthdr.csum_data; /* checksum offset */ 886 887 if (offset + sizeof(u_short) > m->m_len) { 888 printf("delayed m_pullup, m->len: %d off: %d p: %d\n", 889 m->m_len, offset, ip->ip_p); 890 /* 891 * XXX 892 * this shouldn't happen, but if it does, the 893 * correct behavior may be to insert the checksum 894 * in the appropriate next mbuf in the chain. 895 */ 896 return; 897 } 898 *(u_short *)(m->m_data + offset) = csum; 899} 900 901/* 902 * IP socket option processing. 903 */ 904int 905ip_ctloutput(struct socket *so, struct sockopt *sopt) 906{ 907 struct inpcb *inp = sotoinpcb(so); 908 int error, optval; 909 910 error = optval = 0; 911 if (sopt->sopt_level != IPPROTO_IP) { 912 error = EINVAL; 913 914 if (sopt->sopt_level == SOL_SOCKET && 915 sopt->sopt_dir == SOPT_SET) { 916 switch (sopt->sopt_name) { 917 case SO_REUSEADDR: 918 INP_WLOCK(inp); 919 if ((so->so_options & SO_REUSEADDR) != 0) 920 inp->inp_flags2 |= INP_REUSEADDR; 921 else 922 inp->inp_flags2 &= ~INP_REUSEADDR; 923 INP_WUNLOCK(inp); 924 error = 0; 925 break; 926 case SO_REUSEPORT: 927 INP_WLOCK(inp); 928 if ((so->so_options & SO_REUSEPORT) != 0) 929 inp->inp_flags2 |= INP_REUSEPORT; 930 else 931 inp->inp_flags2 &= ~INP_REUSEPORT; 932 INP_WUNLOCK(inp); 933 error = 0; 934 break; 935 case SO_SETFIB: 936 INP_WLOCK(inp); 937 inp->inp_inc.inc_fibnum = so->so_fibnum; 938 INP_WUNLOCK(inp); 939 error = 0; 940 break; 941 default: 942 break; 943 } 944 } 945 return (error); 946 } 947 948 switch (sopt->sopt_dir) { 949 case SOPT_SET: 950 switch (sopt->sopt_name) { 951 case IP_OPTIONS: 952#ifdef notyet 953 case IP_RETOPTS: 954#endif 955 { 956 struct mbuf *m; 957 if (sopt->sopt_valsize > MLEN) { 958 error = EMSGSIZE; 959 break; 960 } 961 m = m_get(sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA); 962 if (m == NULL) { 963 error = ENOBUFS; 964 break; 965 } 966 m->m_len = sopt->sopt_valsize; 967 error = sooptcopyin(sopt, mtod(m, char *), m->m_len, 968 m->m_len); 969 if (error) { 970 m_free(m); 971 break; 972 } 973 INP_WLOCK(inp); 974 error = ip_pcbopts(inp, sopt->sopt_name, m); 975 INP_WUNLOCK(inp); 976 return (error); 977 } 978 979 case IP_BINDANY: 980 if (sopt->sopt_td != NULL) { 981 error = priv_check(sopt->sopt_td, 982 PRIV_NETINET_BINDANY); 983 if (error) 984 break; 985 } 986 /* FALLTHROUGH */ 987 case IP_TOS: 988 case IP_TTL: 989 case IP_MINTTL: 990 case IP_RECVOPTS: 991 case IP_RECVRETOPTS: 992 case IP_RECVDSTADDR: 993 case IP_RECVTTL: 994 case IP_RECVIF: 995 case IP_FAITH: 996 case IP_ONESBCAST: 997 case IP_DONTFRAG: 998 case IP_RECVTOS: 999 error = sooptcopyin(sopt, &optval, sizeof optval, 1000 sizeof optval); 1001 if (error) 1002 break; 1003 1004 switch (sopt->sopt_name) { 1005 case IP_TOS: 1006 inp->inp_ip_tos = optval; 1007 break; 1008 1009 case IP_TTL: 1010 inp->inp_ip_ttl = optval; 1011 break; 1012 1013 case IP_MINTTL: 1014 if (optval >= 0 && optval <= MAXTTL) 1015 inp->inp_ip_minttl = optval; 1016 else 1017 error = EINVAL; 1018 break; 1019 1020#define OPTSET(bit) do { \ 1021 INP_WLOCK(inp); \ 1022 if (optval) \ 1023 inp->inp_flags |= bit; \ 1024 else \ 1025 inp->inp_flags &= ~bit; \ 1026 INP_WUNLOCK(inp); \ 1027} while (0) 1028 1029 case IP_RECVOPTS: 1030 OPTSET(INP_RECVOPTS); 1031 break; 1032 1033 case IP_RECVRETOPTS: 1034 OPTSET(INP_RECVRETOPTS); 1035 break; 1036 1037 case IP_RECVDSTADDR: 1038 OPTSET(INP_RECVDSTADDR); 1039 break; 1040 1041 case IP_RECVTTL: 1042 OPTSET(INP_RECVTTL); 1043 break; 1044 1045 case IP_RECVIF: 1046 OPTSET(INP_RECVIF); 1047 break; 1048 1049 case IP_FAITH: 1050 OPTSET(INP_FAITH); 1051 break; 1052 1053 case IP_ONESBCAST: 1054 OPTSET(INP_ONESBCAST); 1055 break; 1056 case IP_DONTFRAG: 1057 OPTSET(INP_DONTFRAG); 1058 break; 1059 case IP_BINDANY: 1060 OPTSET(INP_BINDANY); 1061 break; 1062 case IP_RECVTOS: 1063 OPTSET(INP_RECVTOS); 1064 break; 1065 } 1066 break; 1067#undef OPTSET 1068 1069 /* 1070 * Multicast socket options are processed by the in_mcast 1071 * module. 1072 */ 1073 case IP_MULTICAST_IF: 1074 case IP_MULTICAST_VIF: 1075 case IP_MULTICAST_TTL: 1076 case IP_MULTICAST_LOOP: 1077 case IP_ADD_MEMBERSHIP: 1078 case IP_DROP_MEMBERSHIP: 1079 case IP_ADD_SOURCE_MEMBERSHIP: 1080 case IP_DROP_SOURCE_MEMBERSHIP: 1081 case IP_BLOCK_SOURCE: 1082 case IP_UNBLOCK_SOURCE: 1083 case IP_MSFILTER: 1084 case MCAST_JOIN_GROUP: 1085 case MCAST_LEAVE_GROUP: 1086 case MCAST_JOIN_SOURCE_GROUP: 1087 case MCAST_LEAVE_SOURCE_GROUP: 1088 case MCAST_BLOCK_SOURCE: 1089 case MCAST_UNBLOCK_SOURCE: 1090 error = inp_setmoptions(inp, sopt); 1091 break; 1092 1093 case IP_PORTRANGE: 1094 error = sooptcopyin(sopt, &optval, sizeof optval, 1095 sizeof optval); 1096 if (error) 1097 break; 1098 1099 INP_WLOCK(inp); 1100 switch (optval) { 1101 case IP_PORTRANGE_DEFAULT: 1102 inp->inp_flags &= ~(INP_LOWPORT); 1103 inp->inp_flags &= ~(INP_HIGHPORT); 1104 break; 1105 1106 case IP_PORTRANGE_HIGH: 1107 inp->inp_flags &= ~(INP_LOWPORT); 1108 inp->inp_flags |= INP_HIGHPORT; 1109 break; 1110 1111 case IP_PORTRANGE_LOW: 1112 inp->inp_flags &= ~(INP_HIGHPORT); 1113 inp->inp_flags |= INP_LOWPORT; 1114 break; 1115 1116 default: 1117 error = EINVAL; 1118 break; 1119 } 1120 INP_WUNLOCK(inp); 1121 break; 1122 1123#ifdef IPSEC 1124 case IP_IPSEC_POLICY: 1125 { 1126 caddr_t req; 1127 struct mbuf *m; 1128 1129 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */ 1130 break; 1131 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */ 1132 break; 1133 req = mtod(m, caddr_t); 1134 error = ipsec_set_policy(inp, sopt->sopt_name, req, 1135 m->m_len, (sopt->sopt_td != NULL) ? 1136 sopt->sopt_td->td_ucred : NULL); 1137 m_freem(m); 1138 break; 1139 } 1140#endif /* IPSEC */ 1141 1142 default: 1143 error = ENOPROTOOPT; 1144 break; 1145 } 1146 break; 1147 1148 case SOPT_GET: 1149 switch (sopt->sopt_name) { 1150 case IP_OPTIONS: 1151 case IP_RETOPTS: 1152 if (inp->inp_options) 1153 error = sooptcopyout(sopt, 1154 mtod(inp->inp_options, 1155 char *), 1156 inp->inp_options->m_len); 1157 else 1158 sopt->sopt_valsize = 0; 1159 break; 1160 1161 case IP_TOS: 1162 case IP_TTL: 1163 case IP_MINTTL: 1164 case IP_RECVOPTS: 1165 case IP_RECVRETOPTS: 1166 case IP_RECVDSTADDR: 1167 case IP_RECVTTL: 1168 case IP_RECVIF: 1169 case IP_PORTRANGE: 1170 case IP_FAITH: 1171 case IP_ONESBCAST: 1172 case IP_DONTFRAG: 1173 case IP_BINDANY: 1174 case IP_RECVTOS: 1175 switch (sopt->sopt_name) { 1176 1177 case IP_TOS: 1178 optval = inp->inp_ip_tos; 1179 break; 1180 1181 case IP_TTL: 1182 optval = inp->inp_ip_ttl; 1183 break; 1184 1185 case IP_MINTTL: 1186 optval = inp->inp_ip_minttl; 1187 break; 1188 1189#define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1190 1191 case IP_RECVOPTS: 1192 optval = OPTBIT(INP_RECVOPTS); 1193 break; 1194 1195 case IP_RECVRETOPTS: 1196 optval = OPTBIT(INP_RECVRETOPTS); 1197 break; 1198 1199 case IP_RECVDSTADDR: 1200 optval = OPTBIT(INP_RECVDSTADDR); 1201 break; 1202 1203 case IP_RECVTTL: 1204 optval = OPTBIT(INP_RECVTTL); 1205 break; 1206 1207 case IP_RECVIF: 1208 optval = OPTBIT(INP_RECVIF); 1209 break; 1210 1211 case IP_PORTRANGE: 1212 if (inp->inp_flags & INP_HIGHPORT) 1213 optval = IP_PORTRANGE_HIGH; 1214 else if (inp->inp_flags & INP_LOWPORT) 1215 optval = IP_PORTRANGE_LOW; 1216 else 1217 optval = 0; 1218 break; 1219 1220 case IP_FAITH: 1221 optval = OPTBIT(INP_FAITH); 1222 break; 1223 1224 case IP_ONESBCAST: 1225 optval = OPTBIT(INP_ONESBCAST); 1226 break; 1227 case IP_DONTFRAG: 1228 optval = OPTBIT(INP_DONTFRAG); 1229 break; 1230 case IP_BINDANY: 1231 optval = OPTBIT(INP_BINDANY); 1232 break; 1233 case IP_RECVTOS: 1234 optval = OPTBIT(INP_RECVTOS); 1235 break; 1236 } 1237 error = sooptcopyout(sopt, &optval, sizeof optval); 1238 break; 1239 1240 /* 1241 * Multicast socket options are processed by the in_mcast 1242 * module. 1243 */ 1244 case IP_MULTICAST_IF: 1245 case IP_MULTICAST_VIF: 1246 case IP_MULTICAST_TTL: 1247 case IP_MULTICAST_LOOP: 1248 case IP_MSFILTER: 1249 error = inp_getmoptions(inp, sopt); 1250 break; 1251 1252#ifdef IPSEC 1253 case IP_IPSEC_POLICY: 1254 { 1255 struct mbuf *m = NULL; 1256 caddr_t req = NULL; 1257 size_t len = 0; 1258 1259 if (m != 0) { 1260 req = mtod(m, caddr_t); 1261 len = m->m_len; 1262 } 1263 error = ipsec_get_policy(sotoinpcb(so), req, len, &m); 1264 if (error == 0) 1265 error = soopt_mcopyout(sopt, m); /* XXX */ 1266 if (error == 0) 1267 m_freem(m); 1268 break; 1269 } 1270#endif /* IPSEC */ 1271 1272 default: 1273 error = ENOPROTOOPT; 1274 break; 1275 } 1276 break; 1277 } 1278 return (error); 1279} 1280 1281/* 1282 * Routine called from ip_output() to loop back a copy of an IP multicast 1283 * packet to the input queue of a specified interface. Note that this 1284 * calls the output routine of the loopback "driver", but with an interface 1285 * pointer that might NOT be a loopback interface -- evil, but easier than 1286 * replicating that code here. 1287 */ 1288static void 1289ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst, 1290 int hlen) 1291{ 1292 register struct ip *ip; 1293 struct mbuf *copym; 1294 1295 /* 1296 * Make a deep copy of the packet because we're going to 1297 * modify the pack in order to generate checksums. 1298 */ 1299 copym = m_dup(m, M_NOWAIT); 1300 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen)) 1301 copym = m_pullup(copym, hlen); 1302 if (copym != NULL) { 1303 /* If needed, compute the checksum and mark it as valid. */ 1304 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 1305 in_delayed_cksum(copym); 1306 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 1307 copym->m_pkthdr.csum_flags |= 1308 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 1309 copym->m_pkthdr.csum_data = 0xffff; 1310 } 1311 /* 1312 * We don't bother to fragment if the IP length is greater 1313 * than the interface's MTU. Can this possibly matter? 1314 */ 1315 ip = mtod(copym, struct ip *); 1316 ip->ip_sum = 0; 1317 ip->ip_sum = in_cksum(copym, hlen); 1318#if 1 /* XXX */ 1319 if (dst->sin_family != AF_INET) { 1320 printf("ip_mloopback: bad address family %d\n", 1321 dst->sin_family); 1322 dst->sin_family = AF_INET; 1323 } 1324#endif 1325 if_simloop(ifp, copym, dst->sin_family, 0); 1326 } 1327} 1328