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 #include "opt_rss.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/kernel.h> 47 #include <sys/malloc.h> 48 #include <sys/mbuf.h> 49 #include <sys/priv.h> 50 #include <sys/proc.h> 51 #include <sys/protosw.h> 52 #include <sys/sdt.h> 53 #include <sys/socket.h> 54 #include <sys/socketvar.h> 55 #include <sys/sysctl.h> 56 #include <sys/ucred.h> 57 58 #include <net/if.h> 59 #include <net/if_var.h> 60 #include <net/if_llatbl.h> 61 #include <net/netisr.h> 62 #include <net/pfil.h> 63 #include <net/route.h> 64 #include <net/flowtable.h> 65 #ifdef RADIX_MPATH 66 #include <net/radix_mpath.h> 67 #endif 68 #include <net/vnet.h> 69 70 #include <netinet/in.h> 71 #include <netinet/in_kdtrace.h> 72 #include <netinet/in_systm.h> 73 #include <netinet/ip.h> 74 #include <netinet/in_pcb.h> 75 #include <netinet/in_rss.h> 76 #include <netinet/in_var.h> 77 #include <netinet/ip_var.h> 78 #include <netinet/ip_options.h> 79 #ifdef SCTP 80 #include <netinet/sctp.h> 81 #include <netinet/sctp_crc32.h> 82 #endif 83 84 #ifdef IPSEC 85 #include <netinet/ip_ipsec.h> 86 #include <netipsec/ipsec.h> 87 #endif /* IPSEC*/ 88 89 #include <machine/in_cksum.h> 90 91 #include <security/mac/mac_framework.h> 92 93 VNET_DEFINE(u_short, ip_id); 94 95 #ifdef MBUF_STRESS_TEST 96 static int mbuf_frag_size = 0; 97 SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW, 98 &mbuf_frag_size, 0, "Fragment outgoing mbufs to this size"); 99 #endif 100 101 static void ip_mloopback 102 (struct ifnet *, struct mbuf *, struct sockaddr_in *, int); 103 104 105 extern int in_mcast_loop; 106 extern struct protosw inetsw[]; 107 108 /* 109 * IP output. The packet in mbuf chain m contains a skeletal IP 110 * header (with len, off, ttl, proto, tos, src, dst). 111 * The mbuf chain containing the packet will be freed. 112 * The mbuf opt, if present, will not be freed. 113 * If route ro is present and has ro_rt initialized, route lookup would be 114 * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL, 115 * then result of route lookup is stored in ro->ro_rt. 116 * 117 * In the IP forwarding case, the packet will arrive with options already 118 * inserted, so must have a NULL opt pointer. 119 */ 120 int 121 ip_output(struct mbuf *m, struct mbuf *opt, struct route *ro, int flags, 122 struct ip_moptions *imo, struct inpcb *inp) 123 { 124 struct ip *ip; 125 struct ifnet *ifp = NULL; /* keep compiler happy */ 126 struct mbuf *m0; 127 int hlen = sizeof (struct ip); 128 int mtu; 129 int error = 0; 130 struct sockaddr_in *dst; 131 const struct sockaddr_in *gw; 132 struct in_ifaddr *ia; 133 int isbroadcast; 134 uint16_t ip_len, ip_off; 135 struct route iproute; 136 struct rtentry *rte; /* cache for ro->ro_rt */ 137 struct in_addr odst; 138 struct m_tag *fwd_tag = NULL; 139 #ifdef IPSEC 140 int no_route_but_check_spd = 0; 141 #endif 142 M_ASSERTPKTHDR(m); 143 144 if (inp != NULL) { 145 INP_LOCK_ASSERT(inp); 146 M_SETFIB(m, inp->inp_inc.inc_fibnum); 147 if (inp->inp_flags & (INP_HW_FLOWID|INP_SW_FLOWID)) { 148 m->m_pkthdr.flowid = inp->inp_flowid; 149 M_HASHTYPE_SET(m, inp->inp_flowtype); 150 m->m_flags |= M_FLOWID; 151 } 152 } 153 154 if (ro == NULL) { 155 ro = &iproute; 156 bzero(ro, sizeof (*ro)); 157 } 158 159 #ifdef FLOWTABLE 160 if (ro->ro_rt == NULL) 161 (void )flowtable_lookup(AF_INET, m, ro); 162 #endif 163 164 if (opt) { 165 int len = 0; 166 m = ip_insertoptions(m, opt, &len); 167 if (len != 0) 168 hlen = len; /* ip->ip_hl is updated above */ 169 } 170 ip = mtod(m, struct ip *); 171 ip_len = ntohs(ip->ip_len); 172 ip_off = ntohs(ip->ip_off); 173 174 /* 175 * Fill in IP header. If we are not allowing fragmentation, 176 * then the ip_id field is meaningless, but we don't set it 177 * to zero. Doing so causes various problems when devices along 178 * the path (routers, load balancers, firewalls, etc.) illegally 179 * disable DF on our packet. Note that a 16-bit counter 180 * will wrap around in less than 10 seconds at 100 Mbit/s on a 181 * medium with MTU 1500. See Steven M. Bellovin, "A Technique 182 * for Counting NATted Hosts", Proc. IMW'02, available at 183 * <http://www.cs.columbia.edu/~smb/papers/fnat.pdf>. 184 */ 185 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 186 ip->ip_v = IPVERSION; 187 ip->ip_hl = hlen >> 2; 188 ip->ip_id = ip_newid(); 189 IPSTAT_INC(ips_localout); 190 } else { 191 /* Header already set, fetch hlen from there */ 192 hlen = ip->ip_hl << 2; 193 } 194 195 /* 196 * dst/gw handling: 197 * 198 * dst can be rewritten but always points to &ro->ro_dst. 199 * gw is readonly but can point either to dst OR rt_gateway, 200 * therefore we need restore gw if we're redoing lookup. 201 */ 202 gw = dst = (struct sockaddr_in *)&ro->ro_dst; 203 again: 204 ia = NULL; 205 /* 206 * If there is a cached route, check that it is to the same 207 * destination and is still up. If not, free it and try again. 208 * The address family should also be checked in case of sharing 209 * the cache with IPv6. 210 */ 211 rte = ro->ro_rt; 212 if (rte && ((rte->rt_flags & RTF_UP) == 0 || 213 rte->rt_ifp == NULL || 214 !RT_LINK_IS_UP(rte->rt_ifp) || 215 dst->sin_family != AF_INET || 216 dst->sin_addr.s_addr != ip->ip_dst.s_addr)) { 217 RO_RTFREE(ro); 218 ro->ro_lle = NULL; 219 rte = NULL; 220 gw = dst; 221 } 222 if (rte == NULL && fwd_tag == NULL) { 223 bzero(dst, sizeof(*dst)); 224 dst->sin_family = AF_INET; 225 dst->sin_len = sizeof(*dst); 226 dst->sin_addr = ip->ip_dst; 227 } 228 /* 229 * If routing to interface only, short circuit routing lookup. 230 * The use of an all-ones broadcast address implies this; an 231 * interface is specified by the broadcast address of an interface, 232 * or the destination address of a ptp interface. 233 */ 234 if (flags & IP_SENDONES) { 235 if ((ia = ifatoia(ifa_ifwithbroadaddr(sintosa(dst)))) == NULL && 236 (ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst), 237 RT_DEFAULT_FIB))) == NULL) { 238 IPSTAT_INC(ips_noroute); 239 error = ENETUNREACH; 240 goto bad; 241 } 242 ip->ip_dst.s_addr = INADDR_BROADCAST; 243 dst->sin_addr = ip->ip_dst; 244 ifp = ia->ia_ifp; 245 ip->ip_ttl = 1; 246 isbroadcast = 1; 247 } else if (flags & IP_ROUTETOIF) { 248 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst), 249 RT_DEFAULT_FIB))) == NULL && 250 (ia = ifatoia(ifa_ifwithnet(sintosa(dst), 0, 251 RT_DEFAULT_FIB))) == NULL) { 252 IPSTAT_INC(ips_noroute); 253 error = ENETUNREACH; 254 goto bad; 255 } 256 ifp = ia->ia_ifp; 257 ip->ip_ttl = 1; 258 isbroadcast = in_broadcast(dst->sin_addr, ifp); 259 } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) && 260 imo != NULL && imo->imo_multicast_ifp != NULL) { 261 /* 262 * Bypass the normal routing lookup for multicast 263 * packets if the interface is specified. 264 */ 265 ifp = imo->imo_multicast_ifp; 266 IFP_TO_IA(ifp, ia); 267 isbroadcast = 0; /* fool gcc */ 268 } else { 269 /* 270 * We want to do any cloning requested by the link layer, 271 * as this is probably required in all cases for correct 272 * operation (as it is for ARP). 273 */ 274 if (rte == NULL) { 275 #ifdef RADIX_MPATH 276 rtalloc_mpath_fib(ro, 277 ntohl(ip->ip_src.s_addr ^ ip->ip_dst.s_addr), 278 inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m)); 279 #else 280 in_rtalloc_ign(ro, 0, 281 inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m)); 282 #endif 283 rte = ro->ro_rt; 284 } 285 if (rte == NULL || 286 rte->rt_ifp == NULL || 287 !RT_LINK_IS_UP(rte->rt_ifp)) { 288 #ifdef IPSEC 289 /* 290 * There is no route for this packet, but it is 291 * possible that a matching SPD entry exists. 292 */ 293 no_route_but_check_spd = 1; 294 mtu = 0; /* Silence GCC warning. */ 295 goto sendit; 296 #endif 297 IPSTAT_INC(ips_noroute); 298 error = EHOSTUNREACH; 299 goto bad; 300 } 301 ia = ifatoia(rte->rt_ifa); 302 ifp = rte->rt_ifp; 303 counter_u64_add(rte->rt_pksent, 1); 304 if (rte->rt_flags & RTF_GATEWAY) 305 gw = (struct sockaddr_in *)rte->rt_gateway; 306 if (rte->rt_flags & RTF_HOST) 307 isbroadcast = (rte->rt_flags & RTF_BROADCAST); 308 else 309 isbroadcast = in_broadcast(gw->sin_addr, ifp); 310 } 311 /* 312 * Calculate MTU. If we have a route that is up, use that, 313 * otherwise use the interface's MTU. 314 */ 315 if (rte != NULL && (rte->rt_flags & (RTF_UP|RTF_HOST))) { 316 /* 317 * This case can happen if the user changed the MTU 318 * of an interface after enabling IP on it. Because 319 * most netifs don't keep track of routes pointing to 320 * them, there is no way for one to update all its 321 * routes when the MTU is changed. 322 */ 323 if (rte->rt_mtu > ifp->if_mtu) 324 rte->rt_mtu = ifp->if_mtu; 325 mtu = rte->rt_mtu; 326 } else { 327 mtu = ifp->if_mtu; 328 } 329 /* Catch a possible divide by zero later. */ 330 KASSERT(mtu > 0, ("%s: mtu %d <= 0, rte=%p (rt_flags=0x%08x) ifp=%p", 331 __func__, mtu, rte, (rte != NULL) ? rte->rt_flags : 0, ifp)); 332 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) { 333 m->m_flags |= M_MCAST; 334 /* 335 * IP destination address is multicast. Make sure "gw" 336 * still points to the address in "ro". (It may have been 337 * changed to point to a gateway address, above.) 338 */ 339 gw = dst; 340 /* 341 * See if the caller provided any multicast options 342 */ 343 if (imo != NULL) { 344 ip->ip_ttl = imo->imo_multicast_ttl; 345 if (imo->imo_multicast_vif != -1) 346 ip->ip_src.s_addr = 347 ip_mcast_src ? 348 ip_mcast_src(imo->imo_multicast_vif) : 349 INADDR_ANY; 350 } else 351 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 352 /* 353 * Confirm that the outgoing interface supports multicast. 354 */ 355 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) { 356 if ((ifp->if_flags & IFF_MULTICAST) == 0) { 357 IPSTAT_INC(ips_noroute); 358 error = ENETUNREACH; 359 goto bad; 360 } 361 } 362 /* 363 * If source address not specified yet, use address 364 * of outgoing interface. 365 */ 366 if (ip->ip_src.s_addr == INADDR_ANY) { 367 /* Interface may have no addresses. */ 368 if (ia != NULL) 369 ip->ip_src = IA_SIN(ia)->sin_addr; 370 } 371 372 if ((imo == NULL && in_mcast_loop) || 373 (imo && imo->imo_multicast_loop)) { 374 /* 375 * Loop back multicast datagram if not expressly 376 * forbidden to do so, even if we are not a member 377 * of the group; ip_input() will filter it later, 378 * thus deferring a hash lookup and mutex acquisition 379 * at the expense of a cheap copy using m_copym(). 380 */ 381 ip_mloopback(ifp, m, dst, hlen); 382 } else { 383 /* 384 * If we are acting as a multicast router, perform 385 * multicast forwarding as if the packet had just 386 * arrived on the interface to which we are about 387 * to send. The multicast forwarding function 388 * recursively calls this function, using the 389 * IP_FORWARDING flag to prevent infinite recursion. 390 * 391 * Multicasts that are looped back by ip_mloopback(), 392 * above, will be forwarded by the ip_input() routine, 393 * if necessary. 394 */ 395 if (V_ip_mrouter && (flags & IP_FORWARDING) == 0) { 396 /* 397 * If rsvp daemon is not running, do not 398 * set ip_moptions. This ensures that the packet 399 * is multicast and not just sent down one link 400 * as prescribed by rsvpd. 401 */ 402 if (!V_rsvp_on) 403 imo = NULL; 404 if (ip_mforward && 405 ip_mforward(ip, ifp, m, imo) != 0) { 406 m_freem(m); 407 goto done; 408 } 409 } 410 } 411 412 /* 413 * Multicasts with a time-to-live of zero may be looped- 414 * back, above, but must not be transmitted on a network. 415 * Also, multicasts addressed to the loopback interface 416 * are not sent -- the above call to ip_mloopback() will 417 * loop back a copy. ip_input() will drop the copy if 418 * this host does not belong to the destination group on 419 * the loopback interface. 420 */ 421 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) { 422 m_freem(m); 423 goto done; 424 } 425 426 goto sendit; 427 } 428 429 /* 430 * If the source address is not specified yet, use the address 431 * of the outoing interface. 432 */ 433 if (ip->ip_src.s_addr == INADDR_ANY) { 434 /* Interface may have no addresses. */ 435 if (ia != NULL) { 436 ip->ip_src = IA_SIN(ia)->sin_addr; 437 } 438 } 439 440 /* 441 * Both in the SMP world, pre-emption world if_transmit() world, 442 * the following code doesn't really function as intended any further. 443 * 444 * + There can and will be multiple CPUs running this code path 445 * in parallel, and we do no lock holding when checking the 446 * queue depth; 447 * + And since other threads can be running concurrently, even if 448 * we do pass this check, another thread may queue some frames 449 * before this thread does and it will end up partially or fully 450 * failing to send anyway; 451 * + if_transmit() based drivers don't necessarily set ifq_len 452 * at all. 453 * 454 * This should be replaced with a method of pushing an entire list 455 * of fragment frames to the driver and have the driver decide 456 * whether it can queue or not queue the entire set. 457 */ 458 #if 0 459 /* 460 * Verify that we have any chance at all of being able to queue the 461 * packet or packet fragments, unless ALTQ is enabled on the given 462 * interface in which case packetdrop should be done by queueing. 463 */ 464 n = ip_len / mtu + 1; /* how many fragments ? */ 465 if ( 466 #ifdef ALTQ 467 (!ALTQ_IS_ENABLED(&ifp->if_snd)) && 468 #endif /* ALTQ */ 469 (ifp->if_snd.ifq_len + n) >= ifp->if_snd.ifq_maxlen ) { 470 error = ENOBUFS; 471 IPSTAT_INC(ips_odropped); 472 ifp->if_snd.ifq_drops += n; 473 goto bad; 474 } 475 #endif 476 477 /* 478 * Look for broadcast address and 479 * verify user is allowed to send 480 * such a packet. 481 */ 482 if (isbroadcast) { 483 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 484 error = EADDRNOTAVAIL; 485 goto bad; 486 } 487 if ((flags & IP_ALLOWBROADCAST) == 0) { 488 error = EACCES; 489 goto bad; 490 } 491 /* don't allow broadcast messages to be fragmented */ 492 if (ip_len > mtu) { 493 error = EMSGSIZE; 494 goto bad; 495 } 496 m->m_flags |= M_BCAST; 497 } else { 498 m->m_flags &= ~M_BCAST; 499 } 500 501 sendit: 502 #ifdef IPSEC 503 switch(ip_ipsec_output(&m, inp, &flags, &error)) { 504 case 1: 505 goto bad; 506 case -1: 507 goto done; 508 case 0: 509 default: 510 break; /* Continue with packet processing. */ 511 } 512 /* 513 * Check if there was a route for this packet; return error if not. 514 */ 515 if (no_route_but_check_spd) { 516 IPSTAT_INC(ips_noroute); 517 error = EHOSTUNREACH; 518 goto bad; 519 } 520 /* Update variables that are affected by ipsec4_output(). */ 521 ip = mtod(m, struct ip *); 522 hlen = ip->ip_hl << 2; 523 #endif /* IPSEC */ 524 525 /* Jump over all PFIL processing if hooks are not active. */ 526 if (!PFIL_HOOKED(&V_inet_pfil_hook)) 527 goto passout; 528 529 /* Run through list of hooks for output packets. */ 530 odst.s_addr = ip->ip_dst.s_addr; 531 error = pfil_run_hooks(&V_inet_pfil_hook, &m, ifp, PFIL_OUT, inp); 532 if (error != 0 || m == NULL) 533 goto done; 534 535 ip = mtod(m, struct ip *); 536 537 /* See if destination IP address was changed by packet filter. */ 538 if (odst.s_addr != ip->ip_dst.s_addr) { 539 m->m_flags |= M_SKIP_FIREWALL; 540 /* If destination is now ourself drop to ip_input(). */ 541 if (in_localip(ip->ip_dst)) { 542 m->m_flags |= M_FASTFWD_OURS; 543 if (m->m_pkthdr.rcvif == NULL) 544 m->m_pkthdr.rcvif = V_loif; 545 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 546 m->m_pkthdr.csum_flags |= 547 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 548 m->m_pkthdr.csum_data = 0xffff; 549 } 550 m->m_pkthdr.csum_flags |= 551 CSUM_IP_CHECKED | CSUM_IP_VALID; 552 #ifdef SCTP 553 if (m->m_pkthdr.csum_flags & CSUM_SCTP) 554 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID; 555 #endif 556 error = netisr_queue(NETISR_IP, m); 557 goto done; 558 } else 559 goto again; /* Redo the routing table lookup. */ 560 } 561 562 /* See if local, if yes, send it to netisr with IP_FASTFWD_OURS. */ 563 if (m->m_flags & M_FASTFWD_OURS) { 564 if (m->m_pkthdr.rcvif == NULL) 565 m->m_pkthdr.rcvif = V_loif; 566 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 567 m->m_pkthdr.csum_flags |= 568 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 569 m->m_pkthdr.csum_data = 0xffff; 570 } 571 #ifdef SCTP 572 if (m->m_pkthdr.csum_flags & CSUM_SCTP) 573 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID; 574 #endif 575 m->m_pkthdr.csum_flags |= 576 CSUM_IP_CHECKED | CSUM_IP_VALID; 577 578 error = netisr_queue(NETISR_IP, m); 579 goto done; 580 } 581 /* Or forward to some other address? */ 582 if ((m->m_flags & M_IP_NEXTHOP) && 583 (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) { 584 bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in)); 585 m->m_flags |= M_SKIP_FIREWALL; 586 m->m_flags &= ~M_IP_NEXTHOP; 587 m_tag_delete(m, fwd_tag); 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 return (error); 701 bad: 702 m_freem(m); 703 goto done; 704 } 705 706 /* 707 * Create a chain of fragments which fit the given mtu. m_frag points to the 708 * mbuf to be fragmented; on return it points to the chain with the fragments. 709 * Return 0 if no error. If error, m_frag may contain a partially built 710 * chain of fragments that should be freed by the caller. 711 * 712 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist) 713 */ 714 int 715 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu, 716 u_long if_hwassist_flags) 717 { 718 int error = 0; 719 int hlen = ip->ip_hl << 2; 720 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */ 721 int off; 722 struct mbuf *m0 = *m_frag; /* the original packet */ 723 int firstlen; 724 struct mbuf **mnext; 725 int nfrags; 726 uint16_t ip_len, ip_off; 727 728 ip_len = ntohs(ip->ip_len); 729 ip_off = ntohs(ip->ip_off); 730 731 if (ip_off & IP_DF) { /* Fragmentation not allowed */ 732 IPSTAT_INC(ips_cantfrag); 733 return EMSGSIZE; 734 } 735 736 /* 737 * Must be able to put at least 8 bytes per fragment. 738 */ 739 if (len < 8) 740 return EMSGSIZE; 741 742 /* 743 * If the interface will not calculate checksums on 744 * fragmented packets, then do it here. 745 */ 746 if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 747 in_delayed_cksum(m0); 748 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 749 } 750 #ifdef SCTP 751 if (m0->m_pkthdr.csum_flags & CSUM_SCTP) { 752 sctp_delayed_cksum(m0, hlen); 753 m0->m_pkthdr.csum_flags &= ~CSUM_SCTP; 754 } 755 #endif 756 if (len > PAGE_SIZE) { 757 /* 758 * Fragment large datagrams such that each segment 759 * contains a multiple of PAGE_SIZE amount of data, 760 * plus headers. This enables a receiver to perform 761 * page-flipping zero-copy optimizations. 762 * 763 * XXX When does this help given that sender and receiver 764 * could have different page sizes, and also mtu could 765 * be less than the receiver's page size ? 766 */ 767 int newlen; 768 struct mbuf *m; 769 770 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next) 771 off += m->m_len; 772 773 /* 774 * firstlen (off - hlen) must be aligned on an 775 * 8-byte boundary 776 */ 777 if (off < hlen) 778 goto smart_frag_failure; 779 off = ((off - hlen) & ~7) + hlen; 780 newlen = (~PAGE_MASK) & mtu; 781 if ((newlen + sizeof (struct ip)) > mtu) { 782 /* we failed, go back the default */ 783 smart_frag_failure: 784 newlen = len; 785 off = hlen + len; 786 } 787 len = newlen; 788 789 } else { 790 off = hlen + len; 791 } 792 793 firstlen = off - hlen; 794 mnext = &m0->m_nextpkt; /* pointer to next packet */ 795 796 /* 797 * Loop through length of segment after first fragment, 798 * make new header and copy data of each part and link onto chain. 799 * Here, m0 is the original packet, m is the fragment being created. 800 * The fragments are linked off the m_nextpkt of the original 801 * packet, which after processing serves as the first fragment. 802 */ 803 for (nfrags = 1; off < ip_len; off += len, nfrags++) { 804 struct ip *mhip; /* ip header on the fragment */ 805 struct mbuf *m; 806 int mhlen = sizeof (struct ip); 807 808 m = m_gethdr(M_NOWAIT, MT_DATA); 809 if (m == NULL) { 810 error = ENOBUFS; 811 IPSTAT_INC(ips_odropped); 812 goto done; 813 } 814 m->m_flags |= (m0->m_flags & M_MCAST); 815 /* 816 * In the first mbuf, leave room for the link header, then 817 * copy the original IP header including options. The payload 818 * goes into an additional mbuf chain returned by m_copym(). 819 */ 820 m->m_data += max_linkhdr; 821 mhip = mtod(m, struct ip *); 822 *mhip = *ip; 823 if (hlen > sizeof (struct ip)) { 824 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 825 mhip->ip_v = IPVERSION; 826 mhip->ip_hl = mhlen >> 2; 827 } 828 m->m_len = mhlen; 829 /* XXX do we need to add ip_off below ? */ 830 mhip->ip_off = ((off - hlen) >> 3) + ip_off; 831 if (off + len >= ip_len) 832 len = ip_len - off; 833 else 834 mhip->ip_off |= IP_MF; 835 mhip->ip_len = htons((u_short)(len + mhlen)); 836 m->m_next = m_copym(m0, off, len, M_NOWAIT); 837 if (m->m_next == NULL) { /* copy failed */ 838 m_free(m); 839 error = ENOBUFS; /* ??? */ 840 IPSTAT_INC(ips_odropped); 841 goto done; 842 } 843 m->m_pkthdr.len = mhlen + len; 844 m->m_pkthdr.rcvif = NULL; 845 #ifdef MAC 846 mac_netinet_fragment(m0, m); 847 #endif 848 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags; 849 mhip->ip_off = htons(mhip->ip_off); 850 mhip->ip_sum = 0; 851 if (m->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) { 852 mhip->ip_sum = in_cksum(m, mhlen); 853 m->m_pkthdr.csum_flags &= ~CSUM_IP; 854 } 855 *mnext = m; 856 mnext = &m->m_nextpkt; 857 } 858 IPSTAT_ADD(ips_ofragments, nfrags); 859 860 /* 861 * Update first fragment by trimming what's been copied out 862 * and updating header. 863 */ 864 m_adj(m0, hlen + firstlen - ip_len); 865 m0->m_pkthdr.len = hlen + firstlen; 866 ip->ip_len = htons((u_short)m0->m_pkthdr.len); 867 ip->ip_off = htons(ip_off | IP_MF); 868 ip->ip_sum = 0; 869 if (m0->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) { 870 ip->ip_sum = in_cksum(m0, hlen); 871 m0->m_pkthdr.csum_flags &= ~CSUM_IP; 872 } 873 874 done: 875 *m_frag = m0; 876 return error; 877 } 878 879 void 880 in_delayed_cksum(struct mbuf *m) 881 { 882 struct ip *ip; 883 uint16_t csum, offset, ip_len; 884 885 ip = mtod(m, struct ip *); 886 offset = ip->ip_hl << 2 ; 887 ip_len = ntohs(ip->ip_len); 888 csum = in_cksum_skip(m, ip_len, offset); 889 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0) 890 csum = 0xffff; 891 offset += m->m_pkthdr.csum_data; /* checksum offset */ 892 893 /* find the mbuf in the chain where the checksum starts*/ 894 while ((m != NULL) && (offset >= m->m_len)) { 895 offset -= m->m_len; 896 m = m->m_next; 897 } 898 KASSERT(m != NULL, ("in_delayed_cksum: checksum outside mbuf chain.")); 899 KASSERT(offset + sizeof(u_short) <= m->m_len, ("in_delayed_cksum: checksum split between mbufs.")); 900 *(u_short *)(m->m_data + offset) = csum; 901 } 902 903 /* 904 * IP socket option processing. 905 */ 906 int 907 ip_ctloutput(struct socket *so, struct sockopt *sopt) 908 { 909 struct inpcb *inp = sotoinpcb(so); 910 int error, optval; 911 912 error = optval = 0; 913 if (sopt->sopt_level != IPPROTO_IP) { 914 error = EINVAL; 915 916 if (sopt->sopt_level == SOL_SOCKET && 917 sopt->sopt_dir == SOPT_SET) { 918 switch (sopt->sopt_name) { 919 case SO_REUSEADDR: 920 INP_WLOCK(inp); 921 if ((so->so_options & SO_REUSEADDR) != 0) 922 inp->inp_flags2 |= INP_REUSEADDR; 923 else 924 inp->inp_flags2 &= ~INP_REUSEADDR; 925 INP_WUNLOCK(inp); 926 error = 0; 927 break; 928 case SO_REUSEPORT: 929 INP_WLOCK(inp); 930 if ((so->so_options & SO_REUSEPORT) != 0) 931 inp->inp_flags2 |= INP_REUSEPORT; 932 else 933 inp->inp_flags2 &= ~INP_REUSEPORT; 934 INP_WUNLOCK(inp); 935 error = 0; 936 break; 937 case SO_SETFIB: 938 INP_WLOCK(inp); 939 inp->inp_inc.inc_fibnum = so->so_fibnum; 940 INP_WUNLOCK(inp); 941 error = 0; 942 break; 943 default: 944 break; 945 } 946 } 947 return (error); 948 } 949 950 switch (sopt->sopt_dir) { 951 case SOPT_SET: 952 switch (sopt->sopt_name) { 953 case IP_OPTIONS: 954 #ifdef notyet 955 case IP_RETOPTS: 956 #endif 957 { 958 struct mbuf *m; 959 if (sopt->sopt_valsize > MLEN) { 960 error = EMSGSIZE; 961 break; 962 } 963 m = m_get(sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA); 964 if (m == NULL) { 965 error = ENOBUFS; 966 break; 967 } 968 m->m_len = sopt->sopt_valsize; 969 error = sooptcopyin(sopt, mtod(m, char *), m->m_len, 970 m->m_len); 971 if (error) { 972 m_free(m); 973 break; 974 } 975 INP_WLOCK(inp); 976 error = ip_pcbopts(inp, sopt->sopt_name, m); 977 INP_WUNLOCK(inp); 978 return (error); 979 } 980 981 case IP_BINDANY: 982 if (sopt->sopt_td != NULL) { 983 error = priv_check(sopt->sopt_td, 984 PRIV_NETINET_BINDANY); 985 if (error) 986 break; 987 } 988 /* FALLTHROUGH */ 989 case IP_TOS: 990 case IP_TTL: 991 case IP_MINTTL: 992 case IP_RECVOPTS: 993 case IP_RECVRETOPTS: 994 case IP_RECVDSTADDR: 995 case IP_RECVTTL: 996 case IP_RECVIF: 997 case IP_FAITH: 998 case IP_ONESBCAST: 999 case IP_DONTFRAG: 1000 case IP_RECVTOS: 1001 error = sooptcopyin(sopt, &optval, sizeof optval, 1002 sizeof optval); 1003 if (error) 1004 break; 1005 1006 switch (sopt->sopt_name) { 1007 case IP_TOS: 1008 inp->inp_ip_tos = optval; 1009 break; 1010 1011 case IP_TTL: 1012 inp->inp_ip_ttl = optval; 1013 break; 1014 1015 case IP_MINTTL: 1016 if (optval >= 0 && optval <= MAXTTL) 1017 inp->inp_ip_minttl = optval; 1018 else 1019 error = EINVAL; 1020 break; 1021 1022 #define OPTSET(bit) do { \ 1023 INP_WLOCK(inp); \ 1024 if (optval) \ 1025 inp->inp_flags |= bit; \ 1026 else \ 1027 inp->inp_flags &= ~bit; \ 1028 INP_WUNLOCK(inp); \ 1029 } while (0) 1030 1031 case IP_RECVOPTS: 1032 OPTSET(INP_RECVOPTS); 1033 break; 1034 1035 case IP_RECVRETOPTS: 1036 OPTSET(INP_RECVRETOPTS); 1037 break; 1038 1039 case IP_RECVDSTADDR: 1040 OPTSET(INP_RECVDSTADDR); 1041 break; 1042 1043 case IP_RECVTTL: 1044 OPTSET(INP_RECVTTL); 1045 break; 1046 1047 case IP_RECVIF: 1048 OPTSET(INP_RECVIF); 1049 break; 1050 1051 case IP_FAITH: 1052 OPTSET(INP_FAITH); 1053 break; 1054 1055 case IP_ONESBCAST: 1056 OPTSET(INP_ONESBCAST); 1057 break; 1058 case IP_DONTFRAG: 1059 OPTSET(INP_DONTFRAG); 1060 break; 1061 case IP_BINDANY: 1062 OPTSET(INP_BINDANY); 1063 break; 1064 case IP_RECVTOS: 1065 OPTSET(INP_RECVTOS); 1066 break; 1067 } 1068 break; 1069 #undef OPTSET 1070 1071 /* 1072 * Multicast socket options are processed by the in_mcast 1073 * module. 1074 */ 1075 case IP_MULTICAST_IF: 1076 case IP_MULTICAST_VIF: 1077 case IP_MULTICAST_TTL: 1078 case IP_MULTICAST_LOOP: 1079 case IP_ADD_MEMBERSHIP: 1080 case IP_DROP_MEMBERSHIP: 1081 case IP_ADD_SOURCE_MEMBERSHIP: 1082 case IP_DROP_SOURCE_MEMBERSHIP: 1083 case IP_BLOCK_SOURCE: 1084 case IP_UNBLOCK_SOURCE: 1085 case IP_MSFILTER: 1086 case MCAST_JOIN_GROUP: 1087 case MCAST_LEAVE_GROUP: 1088 case MCAST_JOIN_SOURCE_GROUP: 1089 case MCAST_LEAVE_SOURCE_GROUP: 1090 case MCAST_BLOCK_SOURCE: 1091 case MCAST_UNBLOCK_SOURCE: 1092 error = inp_setmoptions(inp, sopt); 1093 break; 1094 1095 case IP_PORTRANGE: 1096 error = sooptcopyin(sopt, &optval, sizeof optval, 1097 sizeof optval); 1098 if (error) 1099 break; 1100 1101 INP_WLOCK(inp); 1102 switch (optval) { 1103 case IP_PORTRANGE_DEFAULT: 1104 inp->inp_flags &= ~(INP_LOWPORT); 1105 inp->inp_flags &= ~(INP_HIGHPORT); 1106 break; 1107 1108 case IP_PORTRANGE_HIGH: 1109 inp->inp_flags &= ~(INP_LOWPORT); 1110 inp->inp_flags |= INP_HIGHPORT; 1111 break; 1112 1113 case IP_PORTRANGE_LOW: 1114 inp->inp_flags &= ~(INP_HIGHPORT); 1115 inp->inp_flags |= INP_LOWPORT; 1116 break; 1117 1118 default: 1119 error = EINVAL; 1120 break; 1121 } 1122 INP_WUNLOCK(inp); 1123 break; 1124 1125 #ifdef IPSEC 1126 case IP_IPSEC_POLICY: 1127 { 1128 caddr_t req; 1129 struct mbuf *m; 1130 1131 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */ 1132 break; 1133 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */ 1134 break; 1135 req = mtod(m, caddr_t); 1136 error = ipsec_set_policy(inp, sopt->sopt_name, req, 1137 m->m_len, (sopt->sopt_td != NULL) ? 1138 sopt->sopt_td->td_ucred : NULL); 1139 m_freem(m); 1140 break; 1141 } 1142 #endif /* IPSEC */ 1143 1144 default: 1145 error = ENOPROTOOPT; 1146 break; 1147 } 1148 break; 1149 1150 case SOPT_GET: 1151 switch (sopt->sopt_name) { 1152 case IP_OPTIONS: 1153 case IP_RETOPTS: 1154 if (inp->inp_options) 1155 error = sooptcopyout(sopt, 1156 mtod(inp->inp_options, 1157 char *), 1158 inp->inp_options->m_len); 1159 else 1160 sopt->sopt_valsize = 0; 1161 break; 1162 1163 case IP_TOS: 1164 case IP_TTL: 1165 case IP_MINTTL: 1166 case IP_RECVOPTS: 1167 case IP_RECVRETOPTS: 1168 case IP_RECVDSTADDR: 1169 case IP_RECVTTL: 1170 case IP_RECVIF: 1171 case IP_PORTRANGE: 1172 case IP_FAITH: 1173 case IP_ONESBCAST: 1174 case IP_DONTFRAG: 1175 case IP_BINDANY: 1176 case IP_RECVTOS: 1177 case IP_FLOWID: 1178 case IP_FLOWTYPE: 1179 #ifdef RSS 1180 case IP_RSSCPUID: 1181 #endif 1182 switch (sopt->sopt_name) { 1183 1184 case IP_TOS: 1185 optval = inp->inp_ip_tos; 1186 break; 1187 1188 case IP_TTL: 1189 optval = inp->inp_ip_ttl; 1190 break; 1191 1192 case IP_MINTTL: 1193 optval = inp->inp_ip_minttl; 1194 break; 1195 1196 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1197 1198 case IP_RECVOPTS: 1199 optval = OPTBIT(INP_RECVOPTS); 1200 break; 1201 1202 case IP_RECVRETOPTS: 1203 optval = OPTBIT(INP_RECVRETOPTS); 1204 break; 1205 1206 case IP_RECVDSTADDR: 1207 optval = OPTBIT(INP_RECVDSTADDR); 1208 break; 1209 1210 case IP_RECVTTL: 1211 optval = OPTBIT(INP_RECVTTL); 1212 break; 1213 1214 case IP_RECVIF: 1215 optval = OPTBIT(INP_RECVIF); 1216 break; 1217 1218 case IP_PORTRANGE: 1219 if (inp->inp_flags & INP_HIGHPORT) 1220 optval = IP_PORTRANGE_HIGH; 1221 else if (inp->inp_flags & INP_LOWPORT) 1222 optval = IP_PORTRANGE_LOW; 1223 else 1224 optval = 0; 1225 break; 1226 1227 case IP_FAITH: 1228 optval = OPTBIT(INP_FAITH); 1229 break; 1230 1231 case IP_ONESBCAST: 1232 optval = OPTBIT(INP_ONESBCAST); 1233 break; 1234 case IP_DONTFRAG: 1235 optval = OPTBIT(INP_DONTFRAG); 1236 break; 1237 case IP_BINDANY: 1238 optval = OPTBIT(INP_BINDANY); 1239 break; 1240 case IP_RECVTOS: 1241 optval = OPTBIT(INP_RECVTOS); 1242 break; 1243 case IP_FLOWID: 1244 optval = inp->inp_flowid; 1245 break; 1246 case IP_FLOWTYPE: 1247 optval = inp->inp_flowtype; 1248 break; 1249 #ifdef RSS 1250 case IP_RSSCPUID: 1251 optval = rss_hash2cpuid(inp->inp_flowid, 1252 inp->inp_flowtype); 1253 break; 1254 #endif 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