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 struct flentry *fle; 159 160 /* 161 * The flow table returns route entries valid for up to 30 162 * seconds; we rely on the remainder of ip_output() taking no 163 * longer than that long for the stability of ro_rt. The 164 * flow ID assignment must have happened before this point. 165 */ 166 fle = flowtable_lookup(AF_INET, m); 167 if (fle != NULL) 168 flow_to_route(fle, ro); 169 } 170 #endif 171 172 if (opt) { 173 int len = 0; 174 m = ip_insertoptions(m, opt, &len); 175 if (len != 0) 176 hlen = len; /* ip->ip_hl is updated above */ 177 } 178 ip = mtod(m, struct ip *); 179 ip_len = ntohs(ip->ip_len); 180 ip_off = ntohs(ip->ip_off); 181 182 /* 183 * Fill in IP header. If we are not allowing fragmentation, 184 * then the ip_id field is meaningless, but we don't set it 185 * to zero. Doing so causes various problems when devices along 186 * the path (routers, load balancers, firewalls, etc.) illegally 187 * disable DF on our packet. Note that a 16-bit counter 188 * will wrap around in less than 10 seconds at 100 Mbit/s on a 189 * medium with MTU 1500. See Steven M. Bellovin, "A Technique 190 * for Counting NATted Hosts", Proc. IMW'02, available at 191 * <http://www.cs.columbia.edu/~smb/papers/fnat.pdf>. 192 */ 193 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 194 ip->ip_v = IPVERSION; 195 ip->ip_hl = hlen >> 2; 196 ip->ip_id = ip_newid(); 197 IPSTAT_INC(ips_localout); 198 } else { 199 /* Header already set, fetch hlen from there */ 200 hlen = ip->ip_hl << 2; 201 } 202 203 /* 204 * dst/gw handling: 205 * 206 * dst can be rewritten but always points to &ro->ro_dst. 207 * gw is readonly but can point either to dst OR rt_gateway, 208 * therefore we need restore gw if we're redoing lookup. 209 */ 210 gw = dst = (struct sockaddr_in *)&ro->ro_dst; 211 again: 212 ia = NULL; 213 /* 214 * If there is a cached route, check that it is to the same 215 * destination and is still up. If not, free it and try again. 216 * The address family should also be checked in case of sharing 217 * the cache with IPv6. 218 */ 219 rte = ro->ro_rt; 220 if (rte && ((rte->rt_flags & RTF_UP) == 0 || 221 rte->rt_ifp == NULL || 222 !RT_LINK_IS_UP(rte->rt_ifp) || 223 dst->sin_family != AF_INET || 224 dst->sin_addr.s_addr != ip->ip_dst.s_addr)) { 225 RO_RTFREE(ro); 226 ro->ro_lle = NULL; 227 rte = NULL; 228 gw = dst; 229 } 230 if (rte == NULL && fwd_tag == NULL) { 231 bzero(dst, sizeof(*dst)); 232 dst->sin_family = AF_INET; 233 dst->sin_len = sizeof(*dst); 234 dst->sin_addr = ip->ip_dst; 235 } 236 /* 237 * If routing to interface only, short circuit routing lookup. 238 * The use of an all-ones broadcast address implies this; an 239 * interface is specified by the broadcast address of an interface, 240 * or the destination address of a ptp interface. 241 */ 242 if (flags & IP_SENDONES) { 243 if ((ia = ifatoia(ifa_ifwithbroadaddr(sintosa(dst)))) == NULL && 244 (ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL) { 245 IPSTAT_INC(ips_noroute); 246 error = ENETUNREACH; 247 goto bad; 248 } 249 ip->ip_dst.s_addr = INADDR_BROADCAST; 250 dst->sin_addr = ip->ip_dst; 251 ifp = ia->ia_ifp; 252 ip->ip_ttl = 1; 253 isbroadcast = 1; 254 } else if (flags & IP_ROUTETOIF) { 255 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL && 256 (ia = ifatoia(ifa_ifwithnet(sintosa(dst), 0))) == NULL) { 257 IPSTAT_INC(ips_noroute); 258 error = ENETUNREACH; 259 goto bad; 260 } 261 ifp = ia->ia_ifp; 262 ip->ip_ttl = 1; 263 isbroadcast = in_broadcast(dst->sin_addr, ifp); 264 } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) && 265 imo != NULL && imo->imo_multicast_ifp != NULL) { 266 /* 267 * Bypass the normal routing lookup for multicast 268 * packets if the interface is specified. 269 */ 270 ifp = imo->imo_multicast_ifp; 271 IFP_TO_IA(ifp, ia); 272 isbroadcast = 0; /* fool gcc */ 273 } else { 274 /* 275 * We want to do any cloning requested by the link layer, 276 * as this is probably required in all cases for correct 277 * operation (as it is for ARP). 278 */ 279 if (rte == NULL) { 280 #ifdef RADIX_MPATH 281 rtalloc_mpath_fib(ro, 282 ntohl(ip->ip_src.s_addr ^ ip->ip_dst.s_addr), 283 inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m)); 284 #else 285 in_rtalloc_ign(ro, 0, 286 inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m)); 287 #endif 288 rte = ro->ro_rt; 289 } 290 if (rte == NULL || 291 rte->rt_ifp == NULL || 292 !RT_LINK_IS_UP(rte->rt_ifp)) { 293 #ifdef IPSEC 294 /* 295 * There is no route for this packet, but it is 296 * possible that a matching SPD entry exists. 297 */ 298 no_route_but_check_spd = 1; 299 mtu = 0; /* Silence GCC warning. */ 300 goto sendit; 301 #endif 302 IPSTAT_INC(ips_noroute); 303 error = EHOSTUNREACH; 304 goto bad; 305 } 306 ia = ifatoia(rte->rt_ifa); 307 ifa_ref(&ia->ia_ifa); 308 ifp = rte->rt_ifp; 309 rte->rt_rmx.rmx_pksent++; 310 if (rte->rt_flags & RTF_GATEWAY) 311 gw = (struct sockaddr_in *)rte->rt_gateway; 312 if (rte->rt_flags & RTF_HOST) 313 isbroadcast = (rte->rt_flags & RTF_BROADCAST); 314 else 315 isbroadcast = in_broadcast(gw->sin_addr, ifp); 316 } 317 /* 318 * Calculate MTU. If we have a route that is up, use that, 319 * otherwise use the interface's MTU. 320 */ 321 if (rte != NULL && (rte->rt_flags & (RTF_UP|RTF_HOST))) { 322 /* 323 * This case can happen if the user changed the MTU 324 * of an interface after enabling IP on it. Because 325 * most netifs don't keep track of routes pointing to 326 * them, there is no way for one to update all its 327 * routes when the MTU is changed. 328 */ 329 if (rte->rt_rmx.rmx_mtu > ifp->if_mtu) 330 rte->rt_rmx.rmx_mtu = ifp->if_mtu; 331 mtu = rte->rt_rmx.rmx_mtu; 332 } else { 333 mtu = ifp->if_mtu; 334 } 335 /* Catch a possible divide by zero later. */ 336 KASSERT(mtu > 0, ("%s: mtu %d <= 0, rte=%p (rt_flags=0x%08x) ifp=%p", 337 __func__, mtu, rte, (rte != NULL) ? rte->rt_flags : 0, ifp)); 338 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) { 339 m->m_flags |= M_MCAST; 340 /* 341 * IP destination address is multicast. Make sure "gw" 342 * still points to the address in "ro". (It may have been 343 * changed to point to a gateway address, above.) 344 */ 345 gw = dst; 346 /* 347 * See if the caller provided any multicast options 348 */ 349 if (imo != NULL) { 350 ip->ip_ttl = imo->imo_multicast_ttl; 351 if (imo->imo_multicast_vif != -1) 352 ip->ip_src.s_addr = 353 ip_mcast_src ? 354 ip_mcast_src(imo->imo_multicast_vif) : 355 INADDR_ANY; 356 } else 357 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 358 /* 359 * Confirm that the outgoing interface supports multicast. 360 */ 361 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) { 362 if ((ifp->if_flags & IFF_MULTICAST) == 0) { 363 IPSTAT_INC(ips_noroute); 364 error = ENETUNREACH; 365 goto bad; 366 } 367 } 368 /* 369 * If source address not specified yet, use address 370 * of outgoing interface. 371 */ 372 if (ip->ip_src.s_addr == INADDR_ANY) { 373 /* Interface may have no addresses. */ 374 if (ia != NULL) 375 ip->ip_src = IA_SIN(ia)->sin_addr; 376 } 377 378 if ((imo == NULL && in_mcast_loop) || 379 (imo && imo->imo_multicast_loop)) { 380 /* 381 * Loop back multicast datagram if not expressly 382 * forbidden to do so, even if we are not a member 383 * of the group; ip_input() will filter it later, 384 * thus deferring a hash lookup and mutex acquisition 385 * at the expense of a cheap copy using m_copym(). 386 */ 387 ip_mloopback(ifp, m, dst, hlen); 388 } else { 389 /* 390 * If we are acting as a multicast router, perform 391 * multicast forwarding as if the packet had just 392 * arrived on the interface to which we are about 393 * to send. The multicast forwarding function 394 * recursively calls this function, using the 395 * IP_FORWARDING flag to prevent infinite recursion. 396 * 397 * Multicasts that are looped back by ip_mloopback(), 398 * above, will be forwarded by the ip_input() routine, 399 * if necessary. 400 */ 401 if (V_ip_mrouter && (flags & IP_FORWARDING) == 0) { 402 /* 403 * If rsvp daemon is not running, do not 404 * set ip_moptions. This ensures that the packet 405 * is multicast and not just sent down one link 406 * as prescribed by rsvpd. 407 */ 408 if (!V_rsvp_on) 409 imo = NULL; 410 if (ip_mforward && 411 ip_mforward(ip, ifp, m, imo) != 0) { 412 m_freem(m); 413 goto done; 414 } 415 } 416 } 417 418 /* 419 * Multicasts with a time-to-live of zero may be looped- 420 * back, above, but must not be transmitted on a network. 421 * Also, multicasts addressed to the loopback interface 422 * are not sent -- the above call to ip_mloopback() will 423 * loop back a copy. ip_input() will drop the copy if 424 * this host does not belong to the destination group on 425 * the loopback interface. 426 */ 427 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) { 428 m_freem(m); 429 goto done; 430 } 431 432 goto sendit; 433 } 434 435 /* 436 * If the source address is not specified yet, use the address 437 * of the outoing interface. 438 */ 439 if (ip->ip_src.s_addr == INADDR_ANY) { 440 /* Interface may have no addresses. */ 441 if (ia != NULL) { 442 ip->ip_src = IA_SIN(ia)->sin_addr; 443 } 444 } 445 446 /* 447 * Both in the SMP world, pre-emption world if_transmit() world, 448 * the following code doesn't really function as intended any further. 449 * 450 * + There can and will be multiple CPUs running this code path 451 * in parallel, and we do no lock holding when checking the 452 * queue depth; 453 * + And since other threads can be running concurrently, even if 454 * we do pass this check, another thread may queue some frames 455 * before this thread does and it will end up partially or fully 456 * failing to send anyway; 457 * + if_transmit() based drivers don't necessarily set ifq_len 458 * at all. 459 * 460 * This should be replaced with a method of pushing an entire list 461 * of fragment frames to the driver and have the driver decide 462 * whether it can queue or not queue the entire set. 463 */ 464 #if 0 465 /* 466 * Verify that we have any chance at all of being able to queue the 467 * packet or packet fragments, unless ALTQ is enabled on the given 468 * interface in which case packetdrop should be done by queueing. 469 */ 470 n = ip_len / mtu + 1; /* how many fragments ? */ 471 if ( 472 #ifdef ALTQ 473 (!ALTQ_IS_ENABLED(&ifp->if_snd)) && 474 #endif /* ALTQ */ 475 (ifp->if_snd.ifq_len + n) >= ifp->if_snd.ifq_maxlen ) { 476 error = ENOBUFS; 477 IPSTAT_INC(ips_odropped); 478 ifp->if_snd.ifq_drops += n; 479 goto bad; 480 } 481 #endif 482 483 /* 484 * Look for broadcast address and 485 * verify user is allowed to send 486 * such a packet. 487 */ 488 if (isbroadcast) { 489 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 490 error = EADDRNOTAVAIL; 491 goto bad; 492 } 493 if ((flags & IP_ALLOWBROADCAST) == 0) { 494 error = EACCES; 495 goto bad; 496 } 497 /* don't allow broadcast messages to be fragmented */ 498 if (ip_len > mtu) { 499 error = EMSGSIZE; 500 goto bad; 501 } 502 m->m_flags |= M_BCAST; 503 } else { 504 m->m_flags &= ~M_BCAST; 505 } 506 507 sendit: 508 #ifdef IPSEC 509 switch(ip_ipsec_output(&m, inp, &flags, &error)) { 510 case 1: 511 goto bad; 512 case -1: 513 goto done; 514 case 0: 515 default: 516 break; /* Continue with packet processing. */ 517 } 518 /* 519 * Check if there was a route for this packet; return error if not. 520 */ 521 if (no_route_but_check_spd) { 522 IPSTAT_INC(ips_noroute); 523 error = EHOSTUNREACH; 524 goto bad; 525 } 526 /* Update variables that are affected by ipsec4_output(). */ 527 ip = mtod(m, struct ip *); 528 hlen = ip->ip_hl << 2; 529 #endif /* IPSEC */ 530 531 /* Jump over all PFIL processing if hooks are not active. */ 532 if (!PFIL_HOOKED(&V_inet_pfil_hook)) 533 goto passout; 534 535 /* Run through list of hooks for output packets. */ 536 odst.s_addr = ip->ip_dst.s_addr; 537 error = pfil_run_hooks(&V_inet_pfil_hook, &m, ifp, PFIL_OUT, inp); 538 if (error != 0 || m == NULL) 539 goto done; 540 541 ip = mtod(m, struct ip *); 542 543 /* See if destination IP address was changed by packet filter. */ 544 if (odst.s_addr != ip->ip_dst.s_addr) { 545 m->m_flags |= M_SKIP_FIREWALL; 546 /* If destination is now ourself drop to ip_input(). */ 547 if (in_localip(ip->ip_dst)) { 548 m->m_flags |= M_FASTFWD_OURS; 549 if (m->m_pkthdr.rcvif == NULL) 550 m->m_pkthdr.rcvif = V_loif; 551 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 552 m->m_pkthdr.csum_flags |= 553 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 554 m->m_pkthdr.csum_data = 0xffff; 555 } 556 m->m_pkthdr.csum_flags |= 557 CSUM_IP_CHECKED | CSUM_IP_VALID; 558 #ifdef SCTP 559 if (m->m_pkthdr.csum_flags & CSUM_SCTP) 560 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID; 561 #endif 562 error = netisr_queue(NETISR_IP, m); 563 goto done; 564 } else { 565 if (ia != NULL) 566 ifa_free(&ia->ia_ifa); 567 goto again; /* Redo the routing table lookup. */ 568 } 569 } 570 571 /* See if local, if yes, send it to netisr with IP_FASTFWD_OURS. */ 572 if (m->m_flags & M_FASTFWD_OURS) { 573 if (m->m_pkthdr.rcvif == NULL) 574 m->m_pkthdr.rcvif = V_loif; 575 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 576 m->m_pkthdr.csum_flags |= 577 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 578 m->m_pkthdr.csum_data = 0xffff; 579 } 580 #ifdef SCTP 581 if (m->m_pkthdr.csum_flags & CSUM_SCTP) 582 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID; 583 #endif 584 m->m_pkthdr.csum_flags |= 585 CSUM_IP_CHECKED | CSUM_IP_VALID; 586 587 error = netisr_queue(NETISR_IP, m); 588 goto done; 589 } 590 /* Or forward to some other address? */ 591 if ((m->m_flags & M_IP_NEXTHOP) && 592 (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) { 593 bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in)); 594 m->m_flags |= M_SKIP_FIREWALL; 595 m->m_flags &= ~M_IP_NEXTHOP; 596 m_tag_delete(m, fwd_tag); 597 if (ia != NULL) 598 ifa_free(&ia->ia_ifa); 599 goto again; 600 } 601 602 passout: 603 /* 127/8 must not appear on wire - RFC1122. */ 604 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET || 605 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) { 606 if ((ifp->if_flags & IFF_LOOPBACK) == 0) { 607 IPSTAT_INC(ips_badaddr); 608 error = EADDRNOTAVAIL; 609 goto bad; 610 } 611 } 612 613 m->m_pkthdr.csum_flags |= CSUM_IP; 614 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA & ~ifp->if_hwassist) { 615 in_delayed_cksum(m); 616 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 617 } 618 #ifdef SCTP 619 if (m->m_pkthdr.csum_flags & CSUM_SCTP & ~ifp->if_hwassist) { 620 sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2)); 621 m->m_pkthdr.csum_flags &= ~CSUM_SCTP; 622 } 623 #endif 624 625 /* 626 * If small enough for interface, or the interface will take 627 * care of the fragmentation for us, we can just send directly. 628 */ 629 if (ip_len <= mtu || 630 (m->m_pkthdr.csum_flags & ifp->if_hwassist & CSUM_TSO) != 0 || 631 ((ip_off & IP_DF) == 0 && (ifp->if_hwassist & CSUM_FRAGMENT))) { 632 ip->ip_sum = 0; 633 if (m->m_pkthdr.csum_flags & CSUM_IP & ~ifp->if_hwassist) { 634 ip->ip_sum = in_cksum(m, hlen); 635 m->m_pkthdr.csum_flags &= ~CSUM_IP; 636 } 637 638 /* 639 * Record statistics for this interface address. 640 * With CSUM_TSO the byte/packet count will be slightly 641 * incorrect because we count the IP+TCP headers only 642 * once instead of for every generated packet. 643 */ 644 if (!(flags & IP_FORWARDING) && ia) { 645 if (m->m_pkthdr.csum_flags & CSUM_TSO) 646 counter_u64_add(ia->ia_ifa.ifa_opackets, 647 m->m_pkthdr.len / m->m_pkthdr.tso_segsz); 648 else 649 counter_u64_add(ia->ia_ifa.ifa_opackets, 1); 650 651 counter_u64_add(ia->ia_ifa.ifa_obytes, m->m_pkthdr.len); 652 } 653 #ifdef MBUF_STRESS_TEST 654 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size) 655 m = m_fragment(m, M_NOWAIT, mbuf_frag_size); 656 #endif 657 /* 658 * Reset layer specific mbuf flags 659 * to avoid confusing lower layers. 660 */ 661 m_clrprotoflags(m); 662 IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL); 663 error = (*ifp->if_output)(ifp, m, 664 (const struct sockaddr *)gw, ro); 665 goto done; 666 } 667 668 /* Balk when DF bit is set or the interface didn't support TSO. */ 669 if ((ip_off & IP_DF) || (m->m_pkthdr.csum_flags & CSUM_TSO)) { 670 error = EMSGSIZE; 671 IPSTAT_INC(ips_cantfrag); 672 goto bad; 673 } 674 675 /* 676 * Too large for interface; fragment if possible. If successful, 677 * on return, m will point to a list of packets to be sent. 678 */ 679 error = ip_fragment(ip, &m, mtu, ifp->if_hwassist); 680 if (error) 681 goto bad; 682 for (; m; m = m0) { 683 m0 = m->m_nextpkt; 684 m->m_nextpkt = 0; 685 if (error == 0) { 686 /* Record statistics for this interface address. */ 687 if (ia != NULL) { 688 counter_u64_add(ia->ia_ifa.ifa_opackets, 1); 689 counter_u64_add(ia->ia_ifa.ifa_obytes, 690 m->m_pkthdr.len); 691 } 692 /* 693 * Reset layer specific mbuf flags 694 * to avoid confusing upper layers. 695 */ 696 m_clrprotoflags(m); 697 698 IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL); 699 error = (*ifp->if_output)(ifp, m, 700 (const struct sockaddr *)gw, ro); 701 } else 702 m_freem(m); 703 } 704 705 if (error == 0) 706 IPSTAT_INC(ips_fragmented); 707 708 done: 709 if (ro == &iproute) 710 RO_RTFREE(ro); 711 if (ia != NULL) 712 ifa_free(&ia->ia_ifa); 713 return (error); 714 bad: 715 m_freem(m); 716 goto done; 717 } 718 719 /* 720 * Create a chain of fragments which fit the given mtu. m_frag points to the 721 * mbuf to be fragmented; on return it points to the chain with the fragments. 722 * Return 0 if no error. If error, m_frag may contain a partially built 723 * chain of fragments that should be freed by the caller. 724 * 725 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist) 726 */ 727 int 728 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu, 729 u_long if_hwassist_flags) 730 { 731 int error = 0; 732 int hlen = ip->ip_hl << 2; 733 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */ 734 int off; 735 struct mbuf *m0 = *m_frag; /* the original packet */ 736 int firstlen; 737 struct mbuf **mnext; 738 int nfrags; 739 uint16_t ip_len, ip_off; 740 741 ip_len = ntohs(ip->ip_len); 742 ip_off = ntohs(ip->ip_off); 743 744 if (ip_off & IP_DF) { /* Fragmentation not allowed */ 745 IPSTAT_INC(ips_cantfrag); 746 return EMSGSIZE; 747 } 748 749 /* 750 * Must be able to put at least 8 bytes per fragment. 751 */ 752 if (len < 8) 753 return EMSGSIZE; 754 755 /* 756 * If the interface will not calculate checksums on 757 * fragmented packets, then do it here. 758 */ 759 if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 760 in_delayed_cksum(m0); 761 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 762 } 763 #ifdef SCTP 764 if (m0->m_pkthdr.csum_flags & CSUM_SCTP) { 765 sctp_delayed_cksum(m0, hlen); 766 m0->m_pkthdr.csum_flags &= ~CSUM_SCTP; 767 } 768 #endif 769 if (len > PAGE_SIZE) { 770 /* 771 * Fragment large datagrams such that each segment 772 * contains a multiple of PAGE_SIZE amount of data, 773 * plus headers. This enables a receiver to perform 774 * page-flipping zero-copy optimizations. 775 * 776 * XXX When does this help given that sender and receiver 777 * could have different page sizes, and also mtu could 778 * be less than the receiver's page size ? 779 */ 780 int newlen; 781 struct mbuf *m; 782 783 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next) 784 off += m->m_len; 785 786 /* 787 * firstlen (off - hlen) must be aligned on an 788 * 8-byte boundary 789 */ 790 if (off < hlen) 791 goto smart_frag_failure; 792 off = ((off - hlen) & ~7) + hlen; 793 newlen = (~PAGE_MASK) & mtu; 794 if ((newlen + sizeof (struct ip)) > mtu) { 795 /* we failed, go back the default */ 796 smart_frag_failure: 797 newlen = len; 798 off = hlen + len; 799 } 800 len = newlen; 801 802 } else { 803 off = hlen + len; 804 } 805 806 firstlen = off - hlen; 807 mnext = &m0->m_nextpkt; /* pointer to next packet */ 808 809 /* 810 * Loop through length of segment after first fragment, 811 * make new header and copy data of each part and link onto chain. 812 * Here, m0 is the original packet, m is the fragment being created. 813 * The fragments are linked off the m_nextpkt of the original 814 * packet, which after processing serves as the first fragment. 815 */ 816 for (nfrags = 1; off < ip_len; off += len, nfrags++) { 817 struct ip *mhip; /* ip header on the fragment */ 818 struct mbuf *m; 819 int mhlen = sizeof (struct ip); 820 821 m = m_gethdr(M_NOWAIT, MT_DATA); 822 if (m == NULL) { 823 error = ENOBUFS; 824 IPSTAT_INC(ips_odropped); 825 goto done; 826 } 827 m->m_flags |= (m0->m_flags & M_MCAST); 828 /* 829 * In the first mbuf, leave room for the link header, then 830 * copy the original IP header including options. The payload 831 * goes into an additional mbuf chain returned by m_copym(). 832 */ 833 m->m_data += max_linkhdr; 834 mhip = mtod(m, struct ip *); 835 *mhip = *ip; 836 if (hlen > sizeof (struct ip)) { 837 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 838 mhip->ip_v = IPVERSION; 839 mhip->ip_hl = mhlen >> 2; 840 } 841 m->m_len = mhlen; 842 /* XXX do we need to add ip_off below ? */ 843 mhip->ip_off = ((off - hlen) >> 3) + ip_off; 844 if (off + len >= ip_len) 845 len = ip_len - off; 846 else 847 mhip->ip_off |= IP_MF; 848 mhip->ip_len = htons((u_short)(len + mhlen)); 849 m->m_next = m_copym(m0, off, len, M_NOWAIT); 850 if (m->m_next == NULL) { /* copy failed */ 851 m_free(m); 852 error = ENOBUFS; /* ??? */ 853 IPSTAT_INC(ips_odropped); 854 goto done; 855 } 856 m->m_pkthdr.len = mhlen + len; 857 m->m_pkthdr.rcvif = NULL; 858 #ifdef MAC 859 mac_netinet_fragment(m0, m); 860 #endif 861 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags; 862 mhip->ip_off = htons(mhip->ip_off); 863 mhip->ip_sum = 0; 864 if (m->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) { 865 mhip->ip_sum = in_cksum(m, mhlen); 866 m->m_pkthdr.csum_flags &= ~CSUM_IP; 867 } 868 *mnext = m; 869 mnext = &m->m_nextpkt; 870 } 871 IPSTAT_ADD(ips_ofragments, nfrags); 872 873 /* 874 * Update first fragment by trimming what's been copied out 875 * and updating header. 876 */ 877 m_adj(m0, hlen + firstlen - ip_len); 878 m0->m_pkthdr.len = hlen + firstlen; 879 ip->ip_len = htons((u_short)m0->m_pkthdr.len); 880 ip->ip_off = htons(ip_off | IP_MF); 881 ip->ip_sum = 0; 882 if (m0->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) { 883 ip->ip_sum = in_cksum(m0, hlen); 884 m0->m_pkthdr.csum_flags &= ~CSUM_IP; 885 } 886 887 done: 888 *m_frag = m0; 889 return error; 890 } 891 892 void 893 in_delayed_cksum(struct mbuf *m) 894 { 895 struct ip *ip; 896 uint16_t csum, offset, ip_len; 897 898 ip = mtod(m, struct ip *); 899 offset = ip->ip_hl << 2 ; 900 ip_len = ntohs(ip->ip_len); 901 csum = in_cksum_skip(m, ip_len, offset); 902 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0) 903 csum = 0xffff; 904 offset += m->m_pkthdr.csum_data; /* checksum offset */ 905 906 if (offset + sizeof(u_short) > m->m_len) { 907 printf("delayed m_pullup, m->len: %d off: %d p: %d\n", 908 m->m_len, offset, ip->ip_p); 909 /* 910 * XXX 911 * this shouldn't happen, but if it does, the 912 * correct behavior may be to insert the checksum 913 * in the appropriate next mbuf in the chain. 914 */ 915 return; 916 } 917 *(u_short *)(m->m_data + offset) = csum; 918 } 919 920 /* 921 * IP socket option processing. 922 */ 923 int 924 ip_ctloutput(struct socket *so, struct sockopt *sopt) 925 { 926 struct inpcb *inp = sotoinpcb(so); 927 int error, optval; 928 929 error = optval = 0; 930 if (sopt->sopt_level != IPPROTO_IP) { 931 error = EINVAL; 932 933 if (sopt->sopt_level == SOL_SOCKET && 934 sopt->sopt_dir == SOPT_SET) { 935 switch (sopt->sopt_name) { 936 case SO_REUSEADDR: 937 INP_WLOCK(inp); 938 if ((so->so_options & SO_REUSEADDR) != 0) 939 inp->inp_flags2 |= INP_REUSEADDR; 940 else 941 inp->inp_flags2 &= ~INP_REUSEADDR; 942 INP_WUNLOCK(inp); 943 error = 0; 944 break; 945 case SO_REUSEPORT: 946 INP_WLOCK(inp); 947 if ((so->so_options & SO_REUSEPORT) != 0) 948 inp->inp_flags2 |= INP_REUSEPORT; 949 else 950 inp->inp_flags2 &= ~INP_REUSEPORT; 951 INP_WUNLOCK(inp); 952 error = 0; 953 break; 954 case SO_SETFIB: 955 INP_WLOCK(inp); 956 inp->inp_inc.inc_fibnum = so->so_fibnum; 957 INP_WUNLOCK(inp); 958 error = 0; 959 break; 960 default: 961 break; 962 } 963 } 964 return (error); 965 } 966 967 switch (sopt->sopt_dir) { 968 case SOPT_SET: 969 switch (sopt->sopt_name) { 970 case IP_OPTIONS: 971 #ifdef notyet 972 case IP_RETOPTS: 973 #endif 974 { 975 struct mbuf *m; 976 if (sopt->sopt_valsize > MLEN) { 977 error = EMSGSIZE; 978 break; 979 } 980 m = m_get(sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA); 981 if (m == NULL) { 982 error = ENOBUFS; 983 break; 984 } 985 m->m_len = sopt->sopt_valsize; 986 error = sooptcopyin(sopt, mtod(m, char *), m->m_len, 987 m->m_len); 988 if (error) { 989 m_free(m); 990 break; 991 } 992 INP_WLOCK(inp); 993 error = ip_pcbopts(inp, sopt->sopt_name, m); 994 INP_WUNLOCK(inp); 995 return (error); 996 } 997 998 case IP_BINDANY: 999 if (sopt->sopt_td != NULL) { 1000 error = priv_check(sopt->sopt_td, 1001 PRIV_NETINET_BINDANY); 1002 if (error) 1003 break; 1004 } 1005 /* FALLTHROUGH */ 1006 case IP_TOS: 1007 case IP_TTL: 1008 case IP_MINTTL: 1009 case IP_RECVOPTS: 1010 case IP_RECVRETOPTS: 1011 case IP_RECVDSTADDR: 1012 case IP_RECVTTL: 1013 case IP_RECVIF: 1014 case IP_FAITH: 1015 case IP_ONESBCAST: 1016 case IP_DONTFRAG: 1017 case IP_RECVTOS: 1018 error = sooptcopyin(sopt, &optval, sizeof optval, 1019 sizeof optval); 1020 if (error) 1021 break; 1022 1023 switch (sopt->sopt_name) { 1024 case IP_TOS: 1025 inp->inp_ip_tos = optval; 1026 break; 1027 1028 case IP_TTL: 1029 inp->inp_ip_ttl = optval; 1030 break; 1031 1032 case IP_MINTTL: 1033 if (optval >= 0 && optval <= MAXTTL) 1034 inp->inp_ip_minttl = optval; 1035 else 1036 error = EINVAL; 1037 break; 1038 1039 #define OPTSET(bit) do { \ 1040 INP_WLOCK(inp); \ 1041 if (optval) \ 1042 inp->inp_flags |= bit; \ 1043 else \ 1044 inp->inp_flags &= ~bit; \ 1045 INP_WUNLOCK(inp); \ 1046 } while (0) 1047 1048 case IP_RECVOPTS: 1049 OPTSET(INP_RECVOPTS); 1050 break; 1051 1052 case IP_RECVRETOPTS: 1053 OPTSET(INP_RECVRETOPTS); 1054 break; 1055 1056 case IP_RECVDSTADDR: 1057 OPTSET(INP_RECVDSTADDR); 1058 break; 1059 1060 case IP_RECVTTL: 1061 OPTSET(INP_RECVTTL); 1062 break; 1063 1064 case IP_RECVIF: 1065 OPTSET(INP_RECVIF); 1066 break; 1067 1068 case IP_FAITH: 1069 OPTSET(INP_FAITH); 1070 break; 1071 1072 case IP_ONESBCAST: 1073 OPTSET(INP_ONESBCAST); 1074 break; 1075 case IP_DONTFRAG: 1076 OPTSET(INP_DONTFRAG); 1077 break; 1078 case IP_BINDANY: 1079 OPTSET(INP_BINDANY); 1080 break; 1081 case IP_RECVTOS: 1082 OPTSET(INP_RECVTOS); 1083 break; 1084 } 1085 break; 1086 #undef OPTSET 1087 1088 /* 1089 * Multicast socket options are processed by the in_mcast 1090 * module. 1091 */ 1092 case IP_MULTICAST_IF: 1093 case IP_MULTICAST_VIF: 1094 case IP_MULTICAST_TTL: 1095 case IP_MULTICAST_LOOP: 1096 case IP_ADD_MEMBERSHIP: 1097 case IP_DROP_MEMBERSHIP: 1098 case IP_ADD_SOURCE_MEMBERSHIP: 1099 case IP_DROP_SOURCE_MEMBERSHIP: 1100 case IP_BLOCK_SOURCE: 1101 case IP_UNBLOCK_SOURCE: 1102 case IP_MSFILTER: 1103 case MCAST_JOIN_GROUP: 1104 case MCAST_LEAVE_GROUP: 1105 case MCAST_JOIN_SOURCE_GROUP: 1106 case MCAST_LEAVE_SOURCE_GROUP: 1107 case MCAST_BLOCK_SOURCE: 1108 case MCAST_UNBLOCK_SOURCE: 1109 error = inp_setmoptions(inp, sopt); 1110 break; 1111 1112 case IP_PORTRANGE: 1113 error = sooptcopyin(sopt, &optval, sizeof optval, 1114 sizeof optval); 1115 if (error) 1116 break; 1117 1118 INP_WLOCK(inp); 1119 switch (optval) { 1120 case IP_PORTRANGE_DEFAULT: 1121 inp->inp_flags &= ~(INP_LOWPORT); 1122 inp->inp_flags &= ~(INP_HIGHPORT); 1123 break; 1124 1125 case IP_PORTRANGE_HIGH: 1126 inp->inp_flags &= ~(INP_LOWPORT); 1127 inp->inp_flags |= INP_HIGHPORT; 1128 break; 1129 1130 case IP_PORTRANGE_LOW: 1131 inp->inp_flags &= ~(INP_HIGHPORT); 1132 inp->inp_flags |= INP_LOWPORT; 1133 break; 1134 1135 default: 1136 error = EINVAL; 1137 break; 1138 } 1139 INP_WUNLOCK(inp); 1140 break; 1141 1142 #ifdef IPSEC 1143 case IP_IPSEC_POLICY: 1144 { 1145 caddr_t req; 1146 struct mbuf *m; 1147 1148 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */ 1149 break; 1150 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */ 1151 break; 1152 req = mtod(m, caddr_t); 1153 error = ipsec_set_policy(inp, sopt->sopt_name, req, 1154 m->m_len, (sopt->sopt_td != NULL) ? 1155 sopt->sopt_td->td_ucred : NULL); 1156 m_freem(m); 1157 break; 1158 } 1159 #endif /* IPSEC */ 1160 1161 default: 1162 error = ENOPROTOOPT; 1163 break; 1164 } 1165 break; 1166 1167 case SOPT_GET: 1168 switch (sopt->sopt_name) { 1169 case IP_OPTIONS: 1170 case IP_RETOPTS: 1171 if (inp->inp_options) 1172 error = sooptcopyout(sopt, 1173 mtod(inp->inp_options, 1174 char *), 1175 inp->inp_options->m_len); 1176 else 1177 sopt->sopt_valsize = 0; 1178 break; 1179 1180 case IP_TOS: 1181 case IP_TTL: 1182 case IP_MINTTL: 1183 case IP_RECVOPTS: 1184 case IP_RECVRETOPTS: 1185 case IP_RECVDSTADDR: 1186 case IP_RECVTTL: 1187 case IP_RECVIF: 1188 case IP_PORTRANGE: 1189 case IP_FAITH: 1190 case IP_ONESBCAST: 1191 case IP_DONTFRAG: 1192 case IP_BINDANY: 1193 case IP_RECVTOS: 1194 switch (sopt->sopt_name) { 1195 1196 case IP_TOS: 1197 optval = inp->inp_ip_tos; 1198 break; 1199 1200 case IP_TTL: 1201 optval = inp->inp_ip_ttl; 1202 break; 1203 1204 case IP_MINTTL: 1205 optval = inp->inp_ip_minttl; 1206 break; 1207 1208 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1209 1210 case IP_RECVOPTS: 1211 optval = OPTBIT(INP_RECVOPTS); 1212 break; 1213 1214 case IP_RECVRETOPTS: 1215 optval = OPTBIT(INP_RECVRETOPTS); 1216 break; 1217 1218 case IP_RECVDSTADDR: 1219 optval = OPTBIT(INP_RECVDSTADDR); 1220 break; 1221 1222 case IP_RECVTTL: 1223 optval = OPTBIT(INP_RECVTTL); 1224 break; 1225 1226 case IP_RECVIF: 1227 optval = OPTBIT(INP_RECVIF); 1228 break; 1229 1230 case IP_PORTRANGE: 1231 if (inp->inp_flags & INP_HIGHPORT) 1232 optval = IP_PORTRANGE_HIGH; 1233 else if (inp->inp_flags & INP_LOWPORT) 1234 optval = IP_PORTRANGE_LOW; 1235 else 1236 optval = 0; 1237 break; 1238 1239 case IP_FAITH: 1240 optval = OPTBIT(INP_FAITH); 1241 break; 1242 1243 case IP_ONESBCAST: 1244 optval = OPTBIT(INP_ONESBCAST); 1245 break; 1246 case IP_DONTFRAG: 1247 optval = OPTBIT(INP_DONTFRAG); 1248 break; 1249 case IP_BINDANY: 1250 optval = OPTBIT(INP_BINDANY); 1251 break; 1252 case IP_RECVTOS: 1253 optval = OPTBIT(INP_RECVTOS); 1254 break; 1255 } 1256 error = sooptcopyout(sopt, &optval, sizeof optval); 1257 break; 1258 1259 /* 1260 * Multicast socket options are processed by the in_mcast 1261 * module. 1262 */ 1263 case IP_MULTICAST_IF: 1264 case IP_MULTICAST_VIF: 1265 case IP_MULTICAST_TTL: 1266 case IP_MULTICAST_LOOP: 1267 case IP_MSFILTER: 1268 error = inp_getmoptions(inp, sopt); 1269 break; 1270 1271 #ifdef IPSEC 1272 case IP_IPSEC_POLICY: 1273 { 1274 struct mbuf *m = NULL; 1275 caddr_t req = NULL; 1276 size_t len = 0; 1277 1278 if (m != 0) { 1279 req = mtod(m, caddr_t); 1280 len = m->m_len; 1281 } 1282 error = ipsec_get_policy(sotoinpcb(so), req, len, &m); 1283 if (error == 0) 1284 error = soopt_mcopyout(sopt, m); /* XXX */ 1285 if (error == 0) 1286 m_freem(m); 1287 break; 1288 } 1289 #endif /* IPSEC */ 1290 1291 default: 1292 error = ENOPROTOOPT; 1293 break; 1294 } 1295 break; 1296 } 1297 return (error); 1298 } 1299 1300 /* 1301 * Routine called from ip_output() to loop back a copy of an IP multicast 1302 * packet to the input queue of a specified interface. Note that this 1303 * calls the output routine of the loopback "driver", but with an interface 1304 * pointer that might NOT be a loopback interface -- evil, but easier than 1305 * replicating that code here. 1306 */ 1307 static void 1308 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst, 1309 int hlen) 1310 { 1311 register struct ip *ip; 1312 struct mbuf *copym; 1313 1314 /* 1315 * Make a deep copy of the packet because we're going to 1316 * modify the pack in order to generate checksums. 1317 */ 1318 copym = m_dup(m, M_NOWAIT); 1319 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen)) 1320 copym = m_pullup(copym, hlen); 1321 if (copym != NULL) { 1322 /* If needed, compute the checksum and mark it as valid. */ 1323 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 1324 in_delayed_cksum(copym); 1325 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 1326 copym->m_pkthdr.csum_flags |= 1327 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 1328 copym->m_pkthdr.csum_data = 0xffff; 1329 } 1330 /* 1331 * We don't bother to fragment if the IP length is greater 1332 * than the interface's MTU. Can this possibly matter? 1333 */ 1334 ip = mtod(copym, struct ip *); 1335 ip->ip_sum = 0; 1336 ip->ip_sum = in_cksum(copym, hlen); 1337 #if 1 /* XXX */ 1338 if (dst->sin_family != AF_INET) { 1339 printf("ip_mloopback: bad address family %d\n", 1340 dst->sin_family); 1341 dst->sin_family = AF_INET; 1342 } 1343 #endif 1344 if_simloop(ifp, copym, dst->sin_family, 0); 1345 } 1346 } 1347