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("$FreeBSD$"); 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 91 VNET_DEFINE(u_short, ip_id); 92 93 #ifdef MBUF_STRESS_TEST 94 static int mbuf_frag_size = 0; 95 SYSCTL_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 99 static void ip_mloopback 100 (struct ifnet *, struct mbuf *, struct sockaddr_in *, int); 101 102 103 extern int in_mcast_loop; 104 extern 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 */ 118 int 119 ip_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; 200 again: 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 ifa_ref(&ia->ia_ifa); 297 ifp = rte->rt_ifp; 298 rte->rt_rmx.rmx_pksent++; 299 if (rte->rt_flags & RTF_GATEWAY) 300 gw = (struct sockaddr_in *)rte->rt_gateway; 301 if (rte->rt_flags & RTF_HOST) 302 isbroadcast = (rte->rt_flags & RTF_BROADCAST); 303 else 304 isbroadcast = in_broadcast(gw->sin_addr, ifp); 305 } 306 /* 307 * Calculate MTU. If we have a route that is up, use that, 308 * otherwise use the interface's MTU. 309 */ 310 if (rte != NULL && (rte->rt_flags & (RTF_UP|RTF_HOST))) { 311 /* 312 * This case can happen if the user changed the MTU 313 * of an interface after enabling IP on it. Because 314 * most netifs don't keep track of routes pointing to 315 * them, there is no way for one to update all its 316 * routes when the MTU is changed. 317 */ 318 if (rte->rt_rmx.rmx_mtu > ifp->if_mtu) 319 rte->rt_rmx.rmx_mtu = ifp->if_mtu; 320 mtu = rte->rt_rmx.rmx_mtu; 321 } else { 322 mtu = ifp->if_mtu; 323 } 324 /* Catch a possible divide by zero later. */ 325 KASSERT(mtu > 0, ("%s: mtu %d <= 0, rte=%p (rt_flags=0x%08x) ifp=%p", 326 __func__, mtu, rte, (rte != NULL) ? rte->rt_flags : 0, ifp)); 327 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) { 328 m->m_flags |= M_MCAST; 329 /* 330 * IP destination address is multicast. Make sure "gw" 331 * still points to the address in "ro". (It may have been 332 * changed to point to a gateway address, above.) 333 */ 334 gw = dst; 335 /* 336 * See if the caller provided any multicast options 337 */ 338 if (imo != NULL) { 339 ip->ip_ttl = imo->imo_multicast_ttl; 340 if (imo->imo_multicast_vif != -1) 341 ip->ip_src.s_addr = 342 ip_mcast_src ? 343 ip_mcast_src(imo->imo_multicast_vif) : 344 INADDR_ANY; 345 } else 346 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 347 /* 348 * Confirm that the outgoing interface supports multicast. 349 */ 350 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) { 351 if ((ifp->if_flags & IFF_MULTICAST) == 0) { 352 IPSTAT_INC(ips_noroute); 353 error = ENETUNREACH; 354 goto bad; 355 } 356 } 357 /* 358 * If source address not specified yet, use address 359 * of outgoing interface. 360 */ 361 if (ip->ip_src.s_addr == INADDR_ANY) { 362 /* Interface may have no addresses. */ 363 if (ia != NULL) 364 ip->ip_src = IA_SIN(ia)->sin_addr; 365 } 366 367 if ((imo == NULL && in_mcast_loop) || 368 (imo && imo->imo_multicast_loop)) { 369 /* 370 * Loop back multicast datagram if not expressly 371 * forbidden to do so, even if we are not a member 372 * of the group; ip_input() will filter it later, 373 * thus deferring a hash lookup and mutex acquisition 374 * at the expense of a cheap copy using m_copym(). 375 */ 376 ip_mloopback(ifp, m, dst, hlen); 377 } else { 378 /* 379 * If we are acting as a multicast router, perform 380 * multicast forwarding as if the packet had just 381 * arrived on the interface to which we are about 382 * to send. The multicast forwarding function 383 * recursively calls this function, using the 384 * IP_FORWARDING flag to prevent infinite recursion. 385 * 386 * Multicasts that are looped back by ip_mloopback(), 387 * above, will be forwarded by the ip_input() routine, 388 * if necessary. 389 */ 390 if (V_ip_mrouter && (flags & IP_FORWARDING) == 0) { 391 /* 392 * If rsvp daemon is not running, do not 393 * set ip_moptions. This ensures that the packet 394 * is multicast and not just sent down one link 395 * as prescribed by rsvpd. 396 */ 397 if (!V_rsvp_on) 398 imo = NULL; 399 if (ip_mforward && 400 ip_mforward(ip, ifp, m, imo) != 0) { 401 m_freem(m); 402 goto done; 403 } 404 } 405 } 406 407 /* 408 * Multicasts with a time-to-live of zero may be looped- 409 * back, above, but must not be transmitted on a network. 410 * Also, multicasts addressed to the loopback interface 411 * are not sent -- the above call to ip_mloopback() will 412 * loop back a copy. ip_input() will drop the copy if 413 * this host does not belong to the destination group on 414 * the loopback interface. 415 */ 416 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) { 417 m_freem(m); 418 goto done; 419 } 420 421 goto sendit; 422 } 423 424 /* 425 * If the source address is not specified yet, use the address 426 * of the outoing interface. 427 */ 428 if (ip->ip_src.s_addr == INADDR_ANY) { 429 /* Interface may have no addresses. */ 430 if (ia != NULL) { 431 ip->ip_src = IA_SIN(ia)->sin_addr; 432 } 433 } 434 435 /* 436 * Both in the SMP world, pre-emption world if_transmit() world, 437 * the following code doesn't really function as intended any further. 438 * 439 * + There can and will be multiple CPUs running this code path 440 * in parallel, and we do no lock holding when checking the 441 * queue depth; 442 * + And since other threads can be running concurrently, even if 443 * we do pass this check, another thread may queue some frames 444 * before this thread does and it will end up partially or fully 445 * failing to send anyway; 446 * + if_transmit() based drivers don't necessarily set ifq_len 447 * at all. 448 * 449 * This should be replaced with a method of pushing an entire list 450 * of fragment frames to the driver and have the driver decide 451 * whether it can queue or not queue the entire set. 452 */ 453 #if 0 454 /* 455 * Verify that we have any chance at all of being able to queue the 456 * packet or packet fragments, unless ALTQ is enabled on the given 457 * interface in which case packetdrop should be done by queueing. 458 */ 459 n = ip_len / mtu + 1; /* how many fragments ? */ 460 if ( 461 #ifdef ALTQ 462 (!ALTQ_IS_ENABLED(&ifp->if_snd)) && 463 #endif /* ALTQ */ 464 (ifp->if_snd.ifq_len + n) >= ifp->if_snd.ifq_maxlen ) { 465 error = ENOBUFS; 466 IPSTAT_INC(ips_odropped); 467 ifp->if_snd.ifq_drops += n; 468 goto bad; 469 } 470 #endif 471 472 /* 473 * Look for broadcast address and 474 * verify user is allowed to send 475 * such a packet. 476 */ 477 if (isbroadcast) { 478 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 479 error = EADDRNOTAVAIL; 480 goto bad; 481 } 482 if ((flags & IP_ALLOWBROADCAST) == 0) { 483 error = EACCES; 484 goto bad; 485 } 486 /* don't allow broadcast messages to be fragmented */ 487 if (ip_len > mtu) { 488 error = EMSGSIZE; 489 goto bad; 490 } 491 m->m_flags |= M_BCAST; 492 } else { 493 m->m_flags &= ~M_BCAST; 494 } 495 496 sendit: 497 #ifdef IPSEC 498 switch(ip_ipsec_output(&m, inp, &flags, &error)) { 499 case 1: 500 goto bad; 501 case -1: 502 goto done; 503 case 0: 504 default: 505 break; /* Continue with packet processing. */ 506 } 507 /* 508 * Check if there was a route for this packet; return error if not. 509 */ 510 if (no_route_but_check_spd) { 511 IPSTAT_INC(ips_noroute); 512 error = EHOSTUNREACH; 513 goto bad; 514 } 515 /* Update variables that are affected by ipsec4_output(). */ 516 ip = mtod(m, struct ip *); 517 hlen = ip->ip_hl << 2; 518 #endif /* IPSEC */ 519 520 /* Jump over all PFIL processing if hooks are not active. */ 521 if (!PFIL_HOOKED(&V_inet_pfil_hook)) 522 goto passout; 523 524 /* Run through list of hooks for output packets. */ 525 odst.s_addr = ip->ip_dst.s_addr; 526 error = pfil_run_hooks(&V_inet_pfil_hook, &m, ifp, PFIL_OUT, inp); 527 if (error != 0 || m == NULL) 528 goto done; 529 530 ip = mtod(m, struct ip *); 531 532 /* See if destination IP address was changed by packet filter. */ 533 if (odst.s_addr != ip->ip_dst.s_addr) { 534 m->m_flags |= M_SKIP_FIREWALL; 535 /* If destination is now ourself drop to ip_input(). */ 536 if (in_localip(ip->ip_dst)) { 537 m->m_flags |= M_FASTFWD_OURS; 538 if (m->m_pkthdr.rcvif == NULL) 539 m->m_pkthdr.rcvif = V_loif; 540 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 541 m->m_pkthdr.csum_flags |= 542 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 543 m->m_pkthdr.csum_data = 0xffff; 544 } 545 m->m_pkthdr.csum_flags |= 546 CSUM_IP_CHECKED | CSUM_IP_VALID; 547 #ifdef SCTP 548 if (m->m_pkthdr.csum_flags & CSUM_SCTP) 549 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID; 550 #endif 551 error = netisr_queue(NETISR_IP, m); 552 goto done; 553 } else { 554 if (ia != NULL) 555 ifa_free(&ia->ia_ifa); 556 goto again; /* Redo the routing table lookup. */ 557 } 558 } 559 560 /* See if local, if yes, send it to netisr with IP_FASTFWD_OURS. */ 561 if (m->m_flags & M_FASTFWD_OURS) { 562 if (m->m_pkthdr.rcvif == NULL) 563 m->m_pkthdr.rcvif = V_loif; 564 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 565 m->m_pkthdr.csum_flags |= 566 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 567 m->m_pkthdr.csum_data = 0xffff; 568 } 569 #ifdef SCTP 570 if (m->m_pkthdr.csum_flags & CSUM_SCTP) 571 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID; 572 #endif 573 m->m_pkthdr.csum_flags |= 574 CSUM_IP_CHECKED | CSUM_IP_VALID; 575 576 error = netisr_queue(NETISR_IP, m); 577 goto done; 578 } 579 /* Or forward to some other address? */ 580 if ((m->m_flags & M_IP_NEXTHOP) && 581 (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) { 582 bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in)); 583 m->m_flags |= M_SKIP_FIREWALL; 584 m->m_flags &= ~M_IP_NEXTHOP; 585 m_tag_delete(m, fwd_tag); 586 if (ia != NULL) 587 ifa_free(&ia->ia_ifa); 588 goto again; 589 } 590 591 passout: 592 /* 127/8 must not appear on wire - RFC1122. */ 593 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET || 594 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) { 595 if ((ifp->if_flags & IFF_LOOPBACK) == 0) { 596 IPSTAT_INC(ips_badaddr); 597 error = EADDRNOTAVAIL; 598 goto bad; 599 } 600 } 601 602 m->m_pkthdr.csum_flags |= CSUM_IP; 603 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA & ~ifp->if_hwassist) { 604 in_delayed_cksum(m); 605 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 606 } 607 #ifdef SCTP 608 if (m->m_pkthdr.csum_flags & CSUM_SCTP & ~ifp->if_hwassist) { 609 sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2)); 610 m->m_pkthdr.csum_flags &= ~CSUM_SCTP; 611 } 612 #endif 613 614 /* 615 * If small enough for interface, or the interface will take 616 * care of the fragmentation for us, we can just send directly. 617 */ 618 if (ip_len <= mtu || 619 (m->m_pkthdr.csum_flags & ifp->if_hwassist & CSUM_TSO) != 0 || 620 ((ip_off & IP_DF) == 0 && (ifp->if_hwassist & CSUM_FRAGMENT))) { 621 ip->ip_sum = 0; 622 if (m->m_pkthdr.csum_flags & CSUM_IP & ~ifp->if_hwassist) { 623 ip->ip_sum = in_cksum(m, hlen); 624 m->m_pkthdr.csum_flags &= ~CSUM_IP; 625 } 626 627 /* 628 * Record statistics for this interface address. 629 * With CSUM_TSO the byte/packet count will be slightly 630 * incorrect because we count the IP+TCP headers only 631 * once instead of for every generated packet. 632 */ 633 if (!(flags & IP_FORWARDING) && ia) { 634 if (m->m_pkthdr.csum_flags & CSUM_TSO) 635 counter_u64_add(ia->ia_ifa.ifa_opackets, 636 m->m_pkthdr.len / m->m_pkthdr.tso_segsz); 637 else 638 counter_u64_add(ia->ia_ifa.ifa_opackets, 1); 639 640 counter_u64_add(ia->ia_ifa.ifa_obytes, m->m_pkthdr.len); 641 } 642 #ifdef MBUF_STRESS_TEST 643 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size) 644 m = m_fragment(m, M_NOWAIT, mbuf_frag_size); 645 #endif 646 /* 647 * Reset layer specific mbuf flags 648 * to avoid confusing lower layers. 649 */ 650 m_clrprotoflags(m); 651 IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL); 652 error = (*ifp->if_output)(ifp, m, 653 (const struct sockaddr *)gw, ro); 654 goto done; 655 } 656 657 /* Balk when DF bit is set or the interface didn't support TSO. */ 658 if ((ip_off & IP_DF) || (m->m_pkthdr.csum_flags & CSUM_TSO)) { 659 error = EMSGSIZE; 660 IPSTAT_INC(ips_cantfrag); 661 goto bad; 662 } 663 664 /* 665 * Too large for interface; fragment if possible. If successful, 666 * on return, m will point to a list of packets to be sent. 667 */ 668 error = ip_fragment(ip, &m, mtu, ifp->if_hwassist); 669 if (error) 670 goto bad; 671 for (; m; m = m0) { 672 m0 = m->m_nextpkt; 673 m->m_nextpkt = 0; 674 if (error == 0) { 675 /* Record statistics for this interface address. */ 676 if (ia != NULL) { 677 counter_u64_add(ia->ia_ifa.ifa_opackets, 1); 678 counter_u64_add(ia->ia_ifa.ifa_obytes, 679 m->m_pkthdr.len); 680 } 681 /* 682 * Reset layer specific mbuf flags 683 * to avoid confusing upper layers. 684 */ 685 m_clrprotoflags(m); 686 687 IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL); 688 error = (*ifp->if_output)(ifp, m, 689 (const struct sockaddr *)gw, ro); 690 } else 691 m_freem(m); 692 } 693 694 if (error == 0) 695 IPSTAT_INC(ips_fragmented); 696 697 done: 698 if (ro == &iproute) 699 RO_RTFREE(ro); 700 if (ia != NULL) 701 ifa_free(&ia->ia_ifa); 702 return (error); 703 bad: 704 m_freem(m); 705 goto done; 706 } 707 708 /* 709 * Create a chain of fragments which fit the given mtu. m_frag points to the 710 * mbuf to be fragmented; on return it points to the chain with the fragments. 711 * Return 0 if no error. If error, m_frag may contain a partially built 712 * chain of fragments that should be freed by the caller. 713 * 714 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist) 715 */ 716 int 717 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu, 718 u_long if_hwassist_flags) 719 { 720 int error = 0; 721 int hlen = ip->ip_hl << 2; 722 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */ 723 int off; 724 struct mbuf *m0 = *m_frag; /* the original packet */ 725 int firstlen; 726 struct mbuf **mnext; 727 int nfrags; 728 uint16_t ip_len, ip_off; 729 730 ip_len = ntohs(ip->ip_len); 731 ip_off = ntohs(ip->ip_off); 732 733 if (ip_off & IP_DF) { /* Fragmentation not allowed */ 734 IPSTAT_INC(ips_cantfrag); 735 return EMSGSIZE; 736 } 737 738 /* 739 * Must be able to put at least 8 bytes per fragment. 740 */ 741 if (len < 8) 742 return EMSGSIZE; 743 744 /* 745 * If the interface will not calculate checksums on 746 * fragmented packets, then do it here. 747 */ 748 if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 749 in_delayed_cksum(m0); 750 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 751 } 752 #ifdef SCTP 753 if (m0->m_pkthdr.csum_flags & CSUM_SCTP) { 754 sctp_delayed_cksum(m0, hlen); 755 m0->m_pkthdr.csum_flags &= ~CSUM_SCTP; 756 } 757 #endif 758 if (len > PAGE_SIZE) { 759 /* 760 * Fragment large datagrams such that each segment 761 * contains a multiple of PAGE_SIZE amount of data, 762 * plus headers. This enables a receiver to perform 763 * page-flipping zero-copy optimizations. 764 * 765 * XXX When does this help given that sender and receiver 766 * could have different page sizes, and also mtu could 767 * be less than the receiver's page size ? 768 */ 769 int newlen; 770 struct mbuf *m; 771 772 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next) 773 off += m->m_len; 774 775 /* 776 * firstlen (off - hlen) must be aligned on an 777 * 8-byte boundary 778 */ 779 if (off < hlen) 780 goto smart_frag_failure; 781 off = ((off - hlen) & ~7) + hlen; 782 newlen = (~PAGE_MASK) & mtu; 783 if ((newlen + sizeof (struct ip)) > mtu) { 784 /* we failed, go back the default */ 785 smart_frag_failure: 786 newlen = len; 787 off = hlen + len; 788 } 789 len = newlen; 790 791 } else { 792 off = hlen + len; 793 } 794 795 firstlen = off - hlen; 796 mnext = &m0->m_nextpkt; /* pointer to next packet */ 797 798 /* 799 * Loop through length of segment after first fragment, 800 * make new header and copy data of each part and link onto chain. 801 * Here, m0 is the original packet, m is the fragment being created. 802 * The fragments are linked off the m_nextpkt of the original 803 * packet, which after processing serves as the first fragment. 804 */ 805 for (nfrags = 1; off < ip_len; off += len, nfrags++) { 806 struct ip *mhip; /* ip header on the fragment */ 807 struct mbuf *m; 808 int mhlen = sizeof (struct ip); 809 810 m = m_gethdr(M_NOWAIT, MT_DATA); 811 if (m == NULL) { 812 error = ENOBUFS; 813 IPSTAT_INC(ips_odropped); 814 goto done; 815 } 816 m->m_flags |= (m0->m_flags & M_MCAST); 817 /* 818 * In the first mbuf, leave room for the link header, then 819 * copy the original IP header including options. The payload 820 * goes into an additional mbuf chain returned by m_copym(). 821 */ 822 m->m_data += max_linkhdr; 823 mhip = mtod(m, struct ip *); 824 *mhip = *ip; 825 if (hlen > sizeof (struct ip)) { 826 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 827 mhip->ip_v = IPVERSION; 828 mhip->ip_hl = mhlen >> 2; 829 } 830 m->m_len = mhlen; 831 /* XXX do we need to add ip_off below ? */ 832 mhip->ip_off = ((off - hlen) >> 3) + ip_off; 833 if (off + len >= ip_len) 834 len = ip_len - off; 835 else 836 mhip->ip_off |= IP_MF; 837 mhip->ip_len = htons((u_short)(len + mhlen)); 838 m->m_next = m_copym(m0, off, len, M_NOWAIT); 839 if (m->m_next == NULL) { /* copy failed */ 840 m_free(m); 841 error = ENOBUFS; /* ??? */ 842 IPSTAT_INC(ips_odropped); 843 goto done; 844 } 845 m->m_pkthdr.len = mhlen + len; 846 m->m_pkthdr.rcvif = NULL; 847 #ifdef MAC 848 mac_netinet_fragment(m0, m); 849 #endif 850 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags; 851 mhip->ip_off = htons(mhip->ip_off); 852 mhip->ip_sum = 0; 853 if (m->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) { 854 mhip->ip_sum = in_cksum(m, mhlen); 855 m->m_pkthdr.csum_flags &= ~CSUM_IP; 856 } 857 *mnext = m; 858 mnext = &m->m_nextpkt; 859 } 860 IPSTAT_ADD(ips_ofragments, nfrags); 861 862 /* 863 * Update first fragment by trimming what's been copied out 864 * and updating header. 865 */ 866 m_adj(m0, hlen + firstlen - ip_len); 867 m0->m_pkthdr.len = hlen + firstlen; 868 ip->ip_len = htons((u_short)m0->m_pkthdr.len); 869 ip->ip_off = htons(ip_off | IP_MF); 870 ip->ip_sum = 0; 871 if (m0->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) { 872 ip->ip_sum = in_cksum(m0, hlen); 873 m0->m_pkthdr.csum_flags &= ~CSUM_IP; 874 } 875 876 done: 877 *m_frag = m0; 878 return error; 879 } 880 881 void 882 in_delayed_cksum(struct mbuf *m) 883 { 884 struct ip *ip; 885 uint16_t csum, offset, ip_len; 886 887 ip = mtod(m, struct ip *); 888 offset = ip->ip_hl << 2 ; 889 ip_len = ntohs(ip->ip_len); 890 csum = in_cksum_skip(m, ip_len, offset); 891 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0) 892 csum = 0xffff; 893 offset += m->m_pkthdr.csum_data; /* checksum offset */ 894 895 if (offset + sizeof(u_short) > m->m_len) { 896 printf("delayed m_pullup, m->len: %d off: %d p: %d\n", 897 m->m_len, offset, ip->ip_p); 898 /* 899 * XXX 900 * this shouldn't happen, but if it does, the 901 * correct behavior may be to insert the checksum 902 * in the appropriate next mbuf in the chain. 903 */ 904 return; 905 } 906 *(u_short *)(m->m_data + offset) = csum; 907 } 908 909 /* 910 * IP socket option processing. 911 */ 912 int 913 ip_ctloutput(struct socket *so, struct sockopt *sopt) 914 { 915 struct inpcb *inp = sotoinpcb(so); 916 int error, optval; 917 918 error = optval = 0; 919 if (sopt->sopt_level != IPPROTO_IP) { 920 error = EINVAL; 921 922 if (sopt->sopt_level == SOL_SOCKET && 923 sopt->sopt_dir == SOPT_SET) { 924 switch (sopt->sopt_name) { 925 case SO_REUSEADDR: 926 INP_WLOCK(inp); 927 if ((so->so_options & SO_REUSEADDR) != 0) 928 inp->inp_flags2 |= INP_REUSEADDR; 929 else 930 inp->inp_flags2 &= ~INP_REUSEADDR; 931 INP_WUNLOCK(inp); 932 error = 0; 933 break; 934 case SO_REUSEPORT: 935 INP_WLOCK(inp); 936 if ((so->so_options & SO_REUSEPORT) != 0) 937 inp->inp_flags2 |= INP_REUSEPORT; 938 else 939 inp->inp_flags2 &= ~INP_REUSEPORT; 940 INP_WUNLOCK(inp); 941 error = 0; 942 break; 943 case SO_SETFIB: 944 INP_WLOCK(inp); 945 inp->inp_inc.inc_fibnum = so->so_fibnum; 946 INP_WUNLOCK(inp); 947 error = 0; 948 break; 949 default: 950 break; 951 } 952 } 953 return (error); 954 } 955 956 switch (sopt->sopt_dir) { 957 case SOPT_SET: 958 switch (sopt->sopt_name) { 959 case IP_OPTIONS: 960 #ifdef notyet 961 case IP_RETOPTS: 962 #endif 963 { 964 struct mbuf *m; 965 if (sopt->sopt_valsize > MLEN) { 966 error = EMSGSIZE; 967 break; 968 } 969 m = m_get(sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA); 970 if (m == NULL) { 971 error = ENOBUFS; 972 break; 973 } 974 m->m_len = sopt->sopt_valsize; 975 error = sooptcopyin(sopt, mtod(m, char *), m->m_len, 976 m->m_len); 977 if (error) { 978 m_free(m); 979 break; 980 } 981 INP_WLOCK(inp); 982 error = ip_pcbopts(inp, sopt->sopt_name, m); 983 INP_WUNLOCK(inp); 984 return (error); 985 } 986 987 case IP_BINDANY: 988 if (sopt->sopt_td != NULL) { 989 error = priv_check(sopt->sopt_td, 990 PRIV_NETINET_BINDANY); 991 if (error) 992 break; 993 } 994 /* FALLTHROUGH */ 995 case IP_TOS: 996 case IP_TTL: 997 case IP_MINTTL: 998 case IP_RECVOPTS: 999 case IP_RECVRETOPTS: 1000 case IP_RECVDSTADDR: 1001 case IP_RECVTTL: 1002 case IP_RECVIF: 1003 case IP_FAITH: 1004 case IP_ONESBCAST: 1005 case IP_DONTFRAG: 1006 case IP_RECVTOS: 1007 error = sooptcopyin(sopt, &optval, sizeof optval, 1008 sizeof optval); 1009 if (error) 1010 break; 1011 1012 switch (sopt->sopt_name) { 1013 case IP_TOS: 1014 inp->inp_ip_tos = optval; 1015 break; 1016 1017 case IP_TTL: 1018 inp->inp_ip_ttl = optval; 1019 break; 1020 1021 case IP_MINTTL: 1022 if (optval >= 0 && optval <= MAXTTL) 1023 inp->inp_ip_minttl = optval; 1024 else 1025 error = EINVAL; 1026 break; 1027 1028 #define OPTSET(bit) do { \ 1029 INP_WLOCK(inp); \ 1030 if (optval) \ 1031 inp->inp_flags |= bit; \ 1032 else \ 1033 inp->inp_flags &= ~bit; \ 1034 INP_WUNLOCK(inp); \ 1035 } while (0) 1036 1037 case IP_RECVOPTS: 1038 OPTSET(INP_RECVOPTS); 1039 break; 1040 1041 case IP_RECVRETOPTS: 1042 OPTSET(INP_RECVRETOPTS); 1043 break; 1044 1045 case IP_RECVDSTADDR: 1046 OPTSET(INP_RECVDSTADDR); 1047 break; 1048 1049 case IP_RECVTTL: 1050 OPTSET(INP_RECVTTL); 1051 break; 1052 1053 case IP_RECVIF: 1054 OPTSET(INP_RECVIF); 1055 break; 1056 1057 case IP_FAITH: 1058 OPTSET(INP_FAITH); 1059 break; 1060 1061 case IP_ONESBCAST: 1062 OPTSET(INP_ONESBCAST); 1063 break; 1064 case IP_DONTFRAG: 1065 OPTSET(INP_DONTFRAG); 1066 break; 1067 case IP_BINDANY: 1068 OPTSET(INP_BINDANY); 1069 break; 1070 case IP_RECVTOS: 1071 OPTSET(INP_RECVTOS); 1072 break; 1073 } 1074 break; 1075 #undef OPTSET 1076 1077 /* 1078 * Multicast socket options are processed by the in_mcast 1079 * module. 1080 */ 1081 case IP_MULTICAST_IF: 1082 case IP_MULTICAST_VIF: 1083 case IP_MULTICAST_TTL: 1084 case IP_MULTICAST_LOOP: 1085 case IP_ADD_MEMBERSHIP: 1086 case IP_DROP_MEMBERSHIP: 1087 case IP_ADD_SOURCE_MEMBERSHIP: 1088 case IP_DROP_SOURCE_MEMBERSHIP: 1089 case IP_BLOCK_SOURCE: 1090 case IP_UNBLOCK_SOURCE: 1091 case IP_MSFILTER: 1092 case MCAST_JOIN_GROUP: 1093 case MCAST_LEAVE_GROUP: 1094 case MCAST_JOIN_SOURCE_GROUP: 1095 case MCAST_LEAVE_SOURCE_GROUP: 1096 case MCAST_BLOCK_SOURCE: 1097 case MCAST_UNBLOCK_SOURCE: 1098 error = inp_setmoptions(inp, sopt); 1099 break; 1100 1101 case IP_PORTRANGE: 1102 error = sooptcopyin(sopt, &optval, sizeof optval, 1103 sizeof optval); 1104 if (error) 1105 break; 1106 1107 INP_WLOCK(inp); 1108 switch (optval) { 1109 case IP_PORTRANGE_DEFAULT: 1110 inp->inp_flags &= ~(INP_LOWPORT); 1111 inp->inp_flags &= ~(INP_HIGHPORT); 1112 break; 1113 1114 case IP_PORTRANGE_HIGH: 1115 inp->inp_flags &= ~(INP_LOWPORT); 1116 inp->inp_flags |= INP_HIGHPORT; 1117 break; 1118 1119 case IP_PORTRANGE_LOW: 1120 inp->inp_flags &= ~(INP_HIGHPORT); 1121 inp->inp_flags |= INP_LOWPORT; 1122 break; 1123 1124 default: 1125 error = EINVAL; 1126 break; 1127 } 1128 INP_WUNLOCK(inp); 1129 break; 1130 1131 #ifdef IPSEC 1132 case IP_IPSEC_POLICY: 1133 { 1134 caddr_t req; 1135 struct mbuf *m; 1136 1137 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */ 1138 break; 1139 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */ 1140 break; 1141 req = mtod(m, caddr_t); 1142 error = ipsec_set_policy(inp, sopt->sopt_name, req, 1143 m->m_len, (sopt->sopt_td != NULL) ? 1144 sopt->sopt_td->td_ucred : NULL); 1145 m_freem(m); 1146 break; 1147 } 1148 #endif /* IPSEC */ 1149 1150 default: 1151 error = ENOPROTOOPT; 1152 break; 1153 } 1154 break; 1155 1156 case SOPT_GET: 1157 switch (sopt->sopt_name) { 1158 case IP_OPTIONS: 1159 case IP_RETOPTS: 1160 if (inp->inp_options) 1161 error = sooptcopyout(sopt, 1162 mtod(inp->inp_options, 1163 char *), 1164 inp->inp_options->m_len); 1165 else 1166 sopt->sopt_valsize = 0; 1167 break; 1168 1169 case IP_TOS: 1170 case IP_TTL: 1171 case IP_MINTTL: 1172 case IP_RECVOPTS: 1173 case IP_RECVRETOPTS: 1174 case IP_RECVDSTADDR: 1175 case IP_RECVTTL: 1176 case IP_RECVIF: 1177 case IP_PORTRANGE: 1178 case IP_FAITH: 1179 case IP_ONESBCAST: 1180 case IP_DONTFRAG: 1181 case IP_BINDANY: 1182 case IP_RECVTOS: 1183 switch (sopt->sopt_name) { 1184 1185 case IP_TOS: 1186 optval = inp->inp_ip_tos; 1187 break; 1188 1189 case IP_TTL: 1190 optval = inp->inp_ip_ttl; 1191 break; 1192 1193 case IP_MINTTL: 1194 optval = inp->inp_ip_minttl; 1195 break; 1196 1197 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1198 1199 case IP_RECVOPTS: 1200 optval = OPTBIT(INP_RECVOPTS); 1201 break; 1202 1203 case IP_RECVRETOPTS: 1204 optval = OPTBIT(INP_RECVRETOPTS); 1205 break; 1206 1207 case IP_RECVDSTADDR: 1208 optval = OPTBIT(INP_RECVDSTADDR); 1209 break; 1210 1211 case IP_RECVTTL: 1212 optval = OPTBIT(INP_RECVTTL); 1213 break; 1214 1215 case IP_RECVIF: 1216 optval = OPTBIT(INP_RECVIF); 1217 break; 1218 1219 case IP_PORTRANGE: 1220 if (inp->inp_flags & INP_HIGHPORT) 1221 optval = IP_PORTRANGE_HIGH; 1222 else if (inp->inp_flags & INP_LOWPORT) 1223 optval = IP_PORTRANGE_LOW; 1224 else 1225 optval = 0; 1226 break; 1227 1228 case IP_FAITH: 1229 optval = OPTBIT(INP_FAITH); 1230 break; 1231 1232 case IP_ONESBCAST: 1233 optval = OPTBIT(INP_ONESBCAST); 1234 break; 1235 case IP_DONTFRAG: 1236 optval = OPTBIT(INP_DONTFRAG); 1237 break; 1238 case IP_BINDANY: 1239 optval = OPTBIT(INP_BINDANY); 1240 break; 1241 case IP_RECVTOS: 1242 optval = OPTBIT(INP_RECVTOS); 1243 break; 1244 } 1245 error = sooptcopyout(sopt, &optval, sizeof optval); 1246 break; 1247 1248 /* 1249 * Multicast socket options are processed by the in_mcast 1250 * module. 1251 */ 1252 case IP_MULTICAST_IF: 1253 case IP_MULTICAST_VIF: 1254 case IP_MULTICAST_TTL: 1255 case IP_MULTICAST_LOOP: 1256 case IP_MSFILTER: 1257 error = inp_getmoptions(inp, sopt); 1258 break; 1259 1260 #ifdef IPSEC 1261 case IP_IPSEC_POLICY: 1262 { 1263 struct mbuf *m = NULL; 1264 caddr_t req = NULL; 1265 size_t len = 0; 1266 1267 if (m != 0) { 1268 req = mtod(m, caddr_t); 1269 len = m->m_len; 1270 } 1271 error = ipsec_get_policy(sotoinpcb(so), req, len, &m); 1272 if (error == 0) 1273 error = soopt_mcopyout(sopt, m); /* XXX */ 1274 if (error == 0) 1275 m_freem(m); 1276 break; 1277 } 1278 #endif /* IPSEC */ 1279 1280 default: 1281 error = ENOPROTOOPT; 1282 break; 1283 } 1284 break; 1285 } 1286 return (error); 1287 } 1288 1289 /* 1290 * Routine called from ip_output() to loop back a copy of an IP multicast 1291 * packet to the input queue of a specified interface. Note that this 1292 * calls the output routine of the loopback "driver", but with an interface 1293 * pointer that might NOT be a loopback interface -- evil, but easier than 1294 * replicating that code here. 1295 */ 1296 static void 1297 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst, 1298 int hlen) 1299 { 1300 register struct ip *ip; 1301 struct mbuf *copym; 1302 1303 /* 1304 * Make a deep copy of the packet because we're going to 1305 * modify the pack in order to generate checksums. 1306 */ 1307 copym = m_dup(m, M_NOWAIT); 1308 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen)) 1309 copym = m_pullup(copym, hlen); 1310 if (copym != NULL) { 1311 /* If needed, compute the checksum and mark it as valid. */ 1312 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 1313 in_delayed_cksum(copym); 1314 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 1315 copym->m_pkthdr.csum_flags |= 1316 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 1317 copym->m_pkthdr.csum_data = 0xffff; 1318 } 1319 /* 1320 * We don't bother to fragment if the IP length is greater 1321 * than the interface's MTU. Can this possibly matter? 1322 */ 1323 ip = mtod(copym, struct ip *); 1324 ip->ip_sum = 0; 1325 ip->ip_sum = in_cksum(copym, hlen); 1326 #if 1 /* XXX */ 1327 if (dst->sin_family != AF_INET) { 1328 printf("ip_mloopback: bad address family %d\n", 1329 dst->sin_family); 1330 dst->sin_family = AF_INET; 1331 } 1332 #endif 1333 if_simloop(ifp, copym, dst->sin_family, 0); 1334 } 1335 } 1336