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_ipfw.h" 36 #include "opt_ipsec.h" 37 #include "opt_mbuf_stress_test.h" 38 #include "opt_mpath.h" 39 #include "opt_route.h" 40 #include "opt_sctp.h" 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/kernel.h> 45 #include <sys/malloc.h> 46 #include <sys/mbuf.h> 47 #include <sys/priv.h> 48 #include <sys/proc.h> 49 #include <sys/protosw.h> 50 #include <sys/sdt.h> 51 #include <sys/socket.h> 52 #include <sys/socketvar.h> 53 #include <sys/sysctl.h> 54 #include <sys/ucred.h> 55 56 #include <net/if.h> 57 #include <net/if_var.h> 58 #include <net/if_llatbl.h> 59 #include <net/netisr.h> 60 #include <net/pfil.h> 61 #include <net/route.h> 62 #include <net/flowtable.h> 63 #ifdef RADIX_MPATH 64 #include <net/radix_mpath.h> 65 #endif 66 #include <net/vnet.h> 67 68 #include <netinet/in.h> 69 #include <netinet/in_kdtrace.h> 70 #include <netinet/in_systm.h> 71 #include <netinet/ip.h> 72 #include <netinet/in_pcb.h> 73 #include <netinet/in_var.h> 74 #include <netinet/ip_var.h> 75 #include <netinet/ip_options.h> 76 #ifdef SCTP 77 #include <netinet/sctp.h> 78 #include <netinet/sctp_crc32.h> 79 #endif 80 81 #ifdef IPSEC 82 #include <netinet/ip_ipsec.h> 83 #include <netipsec/ipsec.h> 84 #endif /* IPSEC*/ 85 86 #include <machine/in_cksum.h> 87 88 #include <security/mac/mac_framework.h> 89 90 VNET_DEFINE(u_short, ip_id); 91 92 #ifdef MBUF_STRESS_TEST 93 static int mbuf_frag_size = 0; 94 SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW, 95 &mbuf_frag_size, 0, "Fragment outgoing mbufs to this size"); 96 #endif 97 98 static void ip_mloopback 99 (struct ifnet *, struct mbuf *, struct sockaddr_in *, int); 100 101 102 extern int in_mcast_loop; 103 extern struct protosw inetsw[]; 104 105 /* 106 * IP output. The packet in mbuf chain m contains a skeletal IP 107 * header (with len, off, ttl, proto, tos, src, dst). 108 * The mbuf chain containing the packet will be freed. 109 * The mbuf opt, if present, will not be freed. 110 * If route ro is present and has ro_rt initialized, route lookup would be 111 * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL, 112 * then result of route lookup is stored in ro->ro_rt. 113 * 114 * In the IP forwarding case, the packet will arrive with options already 115 * inserted, so must have a NULL opt pointer. 116 */ 117 int 118 ip_output(struct mbuf *m, struct mbuf *opt, struct route *ro, int flags, 119 struct ip_moptions *imo, struct inpcb *inp) 120 { 121 struct ip *ip; 122 struct ifnet *ifp = NULL; /* keep compiler happy */ 123 struct mbuf *m0; 124 int hlen = sizeof (struct ip); 125 int mtu; 126 #if 0 127 int n; /* scratchpad */ 128 #endif 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->m_flags |= M_FLOWID; 150 } 151 } 152 153 if (ro == NULL) { 154 ro = &iproute; 155 bzero(ro, sizeof (*ro)); 156 } 157 158 #ifdef FLOWTABLE 159 if (ro->ro_rt == NULL) { 160 struct flentry *fle; 161 162 /* 163 * The flow table returns route entries valid for up to 30 164 * seconds; we rely on the remainder of ip_output() taking no 165 * longer than that long for the stability of ro_rt. The 166 * flow ID assignment must have happened before this point. 167 */ 168 fle = flowtable_lookup_mbuf(V_ip_ft, m, AF_INET); 169 if (fle != NULL) 170 flow_to_route(fle, ro); 171 } 172 #endif 173 174 if (opt) { 175 int len = 0; 176 m = ip_insertoptions(m, opt, &len); 177 if (len != 0) 178 hlen = len; /* ip->ip_hl is updated above */ 179 } 180 ip = mtod(m, struct ip *); 181 ip_len = ntohs(ip->ip_len); 182 ip_off = ntohs(ip->ip_off); 183 184 /* 185 * Fill in IP header. If we are not allowing fragmentation, 186 * then the ip_id field is meaningless, but we don't set it 187 * to zero. Doing so causes various problems when devices along 188 * the path (routers, load balancers, firewalls, etc.) illegally 189 * disable DF on our packet. Note that a 16-bit counter 190 * will wrap around in less than 10 seconds at 100 Mbit/s on a 191 * medium with MTU 1500. See Steven M. Bellovin, "A Technique 192 * for Counting NATted Hosts", Proc. IMW'02, available at 193 * <http://www.cs.columbia.edu/~smb/papers/fnat.pdf>. 194 */ 195 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 196 ip->ip_v = IPVERSION; 197 ip->ip_hl = hlen >> 2; 198 ip->ip_id = ip_newid(); 199 IPSTAT_INC(ips_localout); 200 } else { 201 /* Header already set, fetch hlen from there */ 202 hlen = ip->ip_hl << 2; 203 } 204 205 gw = dst = (struct sockaddr_in *)&ro->ro_dst; 206 again: 207 ia = NULL; 208 /* 209 * If there is a cached route, 210 * check that it is to the same destination 211 * and is still up. If not, free it and try again. 212 * The address family should also be checked in case of sharing the 213 * cache with IPv6. 214 */ 215 rte = ro->ro_rt; 216 if (rte && ((rte->rt_flags & RTF_UP) == 0 || 217 rte->rt_ifp == NULL || 218 !RT_LINK_IS_UP(rte->rt_ifp) || 219 dst->sin_family != AF_INET || 220 dst->sin_addr.s_addr != ip->ip_dst.s_addr)) { 221 RO_RTFREE(ro); 222 ro->ro_lle = NULL; 223 rte = NULL; 224 } 225 if (rte == NULL && fwd_tag == NULL) { 226 bzero(dst, sizeof(*dst)); 227 dst->sin_family = AF_INET; 228 dst->sin_len = sizeof(*dst); 229 dst->sin_addr = ip->ip_dst; 230 } 231 /* 232 * If routing to interface only, short circuit routing lookup. 233 * The use of an all-ones broadcast address implies this; an 234 * interface is specified by the broadcast address of an interface, 235 * or the destination address of a ptp interface. 236 */ 237 if (flags & IP_SENDONES) { 238 if ((ia = ifatoia(ifa_ifwithbroadaddr(sintosa(dst)))) == NULL && 239 (ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL) { 240 IPSTAT_INC(ips_noroute); 241 error = ENETUNREACH; 242 goto bad; 243 } 244 ip->ip_dst.s_addr = INADDR_BROADCAST; 245 dst->sin_addr = ip->ip_dst; 246 ifp = ia->ia_ifp; 247 ip->ip_ttl = 1; 248 isbroadcast = 1; 249 } else if (flags & IP_ROUTETOIF) { 250 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL && 251 (ia = ifatoia(ifa_ifwithnet(sintosa(dst), 0))) == 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 ifa_ref(&ia->ia_ifa); 303 ifp = rte->rt_ifp; 304 rte->rt_rmx.rmx_pksent++; 305 if (rte->rt_flags & RTF_GATEWAY) 306 gw = (struct sockaddr_in *)rte->rt_gateway; 307 if (rte->rt_flags & RTF_HOST) 308 isbroadcast = (rte->rt_flags & RTF_BROADCAST); 309 else 310 isbroadcast = in_broadcast(gw->sin_addr, ifp); 311 } 312 /* 313 * Calculate MTU. If we have a route that is up, use that, 314 * otherwise use the interface's MTU. 315 */ 316 if (rte != NULL && (rte->rt_flags & (RTF_UP|RTF_HOST))) { 317 /* 318 * This case can happen if the user changed the MTU 319 * of an interface after enabling IP on it. Because 320 * most netifs don't keep track of routes pointing to 321 * them, there is no way for one to update all its 322 * routes when the MTU is changed. 323 */ 324 if (rte->rt_rmx.rmx_mtu > ifp->if_mtu) 325 rte->rt_rmx.rmx_mtu = ifp->if_mtu; 326 mtu = rte->rt_rmx.rmx_mtu; 327 } else { 328 mtu = ifp->if_mtu; 329 } 330 /* Catch a possible divide by zero later. */ 331 KASSERT(mtu > 0, ("%s: mtu %d <= 0, rte=%p (rt_flags=0x%08x) ifp=%p", 332 __func__, mtu, rte, (rte != NULL) ? rte->rt_flags : 0, ifp)); 333 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) { 334 m->m_flags |= M_MCAST; 335 /* 336 * IP destination address is multicast. Make sure "gw" 337 * still points to the address in "ro". (It may have been 338 * changed to point to a gateway address, above.) 339 */ 340 gw = dst; 341 /* 342 * See if the caller provided any multicast options 343 */ 344 if (imo != NULL) { 345 ip->ip_ttl = imo->imo_multicast_ttl; 346 if (imo->imo_multicast_vif != -1) 347 ip->ip_src.s_addr = 348 ip_mcast_src ? 349 ip_mcast_src(imo->imo_multicast_vif) : 350 INADDR_ANY; 351 } else 352 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 353 /* 354 * Confirm that the outgoing interface supports multicast. 355 */ 356 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) { 357 if ((ifp->if_flags & IFF_MULTICAST) == 0) { 358 IPSTAT_INC(ips_noroute); 359 error = ENETUNREACH; 360 goto bad; 361 } 362 } 363 /* 364 * If source address not specified yet, use address 365 * of outgoing interface. 366 */ 367 if (ip->ip_src.s_addr == INADDR_ANY) { 368 /* Interface may have no addresses. */ 369 if (ia != NULL) 370 ip->ip_src = IA_SIN(ia)->sin_addr; 371 } 372 373 if ((imo == NULL && in_mcast_loop) || 374 (imo && imo->imo_multicast_loop)) { 375 /* 376 * Loop back multicast datagram if not expressly 377 * forbidden to do so, even if we are not a member 378 * of the group; ip_input() will filter it later, 379 * thus deferring a hash lookup and mutex acquisition 380 * at the expense of a cheap copy using m_copym(). 381 */ 382 ip_mloopback(ifp, m, dst, hlen); 383 } else { 384 /* 385 * If we are acting as a multicast router, perform 386 * multicast forwarding as if the packet had just 387 * arrived on the interface to which we are about 388 * to send. The multicast forwarding function 389 * recursively calls this function, using the 390 * IP_FORWARDING flag to prevent infinite recursion. 391 * 392 * Multicasts that are looped back by ip_mloopback(), 393 * above, will be forwarded by the ip_input() routine, 394 * if necessary. 395 */ 396 if (V_ip_mrouter && (flags & IP_FORWARDING) == 0) { 397 /* 398 * If rsvp daemon is not running, do not 399 * set ip_moptions. This ensures that the packet 400 * is multicast and not just sent down one link 401 * as prescribed by rsvpd. 402 */ 403 if (!V_rsvp_on) 404 imo = NULL; 405 if (ip_mforward && 406 ip_mforward(ip, ifp, m, imo) != 0) { 407 m_freem(m); 408 goto done; 409 } 410 } 411 } 412 413 /* 414 * Multicasts with a time-to-live of zero may be looped- 415 * back, above, but must not be transmitted on a network. 416 * Also, multicasts addressed to the loopback interface 417 * are not sent -- the above call to ip_mloopback() will 418 * loop back a copy. ip_input() will drop the copy if 419 * this host does not belong to the destination group on 420 * the loopback interface. 421 */ 422 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) { 423 m_freem(m); 424 goto done; 425 } 426 427 goto sendit; 428 } 429 430 /* 431 * If the source address is not specified yet, use the address 432 * of the outoing interface. 433 */ 434 if (ip->ip_src.s_addr == INADDR_ANY) { 435 /* Interface may have no addresses. */ 436 if (ia != NULL) { 437 ip->ip_src = IA_SIN(ia)->sin_addr; 438 } 439 } 440 441 /* 442 * Both in the SMP world, pre-emption world if_transmit() world, 443 * the following code doesn't really function as intended any further. 444 * 445 * + There can and will be multiple CPUs running this code path 446 * in parallel, and we do no lock holding when checking the 447 * queue depth; 448 * + And since other threads can be running concurrently, even if 449 * we do pass this check, another thread may queue some frames 450 * before this thread does and it will end up partially or fully 451 * failing to send anyway; 452 * + if_transmit() based drivers don't necessarily set ifq_len 453 * at all. 454 * 455 * This should be replaced with a method of pushing an entire list 456 * of fragment frames to the driver and have the driver decide 457 * whether it can queue or not queue the entire set. 458 */ 459 #if 0 460 /* 461 * Verify that we have any chance at all of being able to queue the 462 * packet or packet fragments, unless ALTQ is enabled on the given 463 * interface in which case packetdrop should be done by queueing. 464 */ 465 n = ip_len / mtu + 1; /* how many fragments ? */ 466 if ( 467 #ifdef ALTQ 468 (!ALTQ_IS_ENABLED(&ifp->if_snd)) && 469 #endif /* ALTQ */ 470 (ifp->if_snd.ifq_len + n) >= ifp->if_snd.ifq_maxlen ) { 471 error = ENOBUFS; 472 IPSTAT_INC(ips_odropped); 473 ifp->if_snd.ifq_drops += n; 474 goto bad; 475 } 476 #endif 477 478 /* 479 * Look for broadcast address and 480 * verify user is allowed to send 481 * such a packet. 482 */ 483 if (isbroadcast) { 484 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 485 error = EADDRNOTAVAIL; 486 goto bad; 487 } 488 if ((flags & IP_ALLOWBROADCAST) == 0) { 489 error = EACCES; 490 goto bad; 491 } 492 /* don't allow broadcast messages to be fragmented */ 493 if (ip_len > mtu) { 494 error = EMSGSIZE; 495 goto bad; 496 } 497 m->m_flags |= M_BCAST; 498 } else { 499 m->m_flags &= ~M_BCAST; 500 } 501 502 sendit: 503 #ifdef IPSEC 504 switch(ip_ipsec_output(&m, inp, &flags, &error)) { 505 case 1: 506 goto bad; 507 case -1: 508 goto done; 509 case 0: 510 default: 511 break; /* Continue with packet processing. */ 512 } 513 /* 514 * Check if there was a route for this packet; return error if not. 515 */ 516 if (no_route_but_check_spd) { 517 IPSTAT_INC(ips_noroute); 518 error = EHOSTUNREACH; 519 goto bad; 520 } 521 /* Update variables that are affected by ipsec4_output(). */ 522 ip = mtod(m, struct ip *); 523 hlen = ip->ip_hl << 2; 524 #endif /* IPSEC */ 525 526 /* Jump over all PFIL processing if hooks are not active. */ 527 if (!PFIL_HOOKED(&V_inet_pfil_hook)) 528 goto passout; 529 530 /* Run through list of hooks for output packets. */ 531 odst.s_addr = ip->ip_dst.s_addr; 532 error = pfil_run_hooks(&V_inet_pfil_hook, &m, ifp, PFIL_OUT, inp); 533 if (error != 0 || m == NULL) 534 goto done; 535 536 ip = mtod(m, struct ip *); 537 538 /* See if destination IP address was changed by packet filter. */ 539 if (odst.s_addr != ip->ip_dst.s_addr) { 540 m->m_flags |= M_SKIP_FIREWALL; 541 /* If destination is now ourself drop to ip_input(). */ 542 if (in_localip(ip->ip_dst)) { 543 m->m_flags |= M_FASTFWD_OURS; 544 if (m->m_pkthdr.rcvif == NULL) 545 m->m_pkthdr.rcvif = V_loif; 546 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 547 m->m_pkthdr.csum_flags |= 548 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 549 m->m_pkthdr.csum_data = 0xffff; 550 } 551 m->m_pkthdr.csum_flags |= 552 CSUM_IP_CHECKED | CSUM_IP_VALID; 553 #ifdef SCTP 554 if (m->m_pkthdr.csum_flags & CSUM_SCTP) 555 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID; 556 #endif 557 error = netisr_queue(NETISR_IP, m); 558 goto done; 559 } else { 560 if (ia != NULL) 561 ifa_free(&ia->ia_ifa); 562 goto again; /* Redo the routing table lookup. */ 563 } 564 } 565 566 /* See if local, if yes, send it to netisr with IP_FASTFWD_OURS. */ 567 if (m->m_flags & M_FASTFWD_OURS) { 568 if (m->m_pkthdr.rcvif == NULL) 569 m->m_pkthdr.rcvif = V_loif; 570 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 571 m->m_pkthdr.csum_flags |= 572 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 573 m->m_pkthdr.csum_data = 0xffff; 574 } 575 #ifdef SCTP 576 if (m->m_pkthdr.csum_flags & CSUM_SCTP) 577 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID; 578 #endif 579 m->m_pkthdr.csum_flags |= 580 CSUM_IP_CHECKED | CSUM_IP_VALID; 581 582 error = netisr_queue(NETISR_IP, m); 583 goto done; 584 } 585 /* Or forward to some other address? */ 586 if ((m->m_flags & M_IP_NEXTHOP) && 587 (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) { 588 bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in)); 589 m->m_flags |= M_SKIP_FIREWALL; 590 m->m_flags &= ~M_IP_NEXTHOP; 591 m_tag_delete(m, fwd_tag); 592 if (ia != NULL) 593 ifa_free(&ia->ia_ifa); 594 goto again; 595 } 596 597 passout: 598 /* 127/8 must not appear on wire - RFC1122. */ 599 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET || 600 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) { 601 if ((ifp->if_flags & IFF_LOOPBACK) == 0) { 602 IPSTAT_INC(ips_badaddr); 603 error = EADDRNOTAVAIL; 604 goto bad; 605 } 606 } 607 608 m->m_pkthdr.csum_flags |= CSUM_IP; 609 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA & ~ifp->if_hwassist) { 610 in_delayed_cksum(m); 611 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 612 } 613 #ifdef SCTP 614 if (m->m_pkthdr.csum_flags & CSUM_SCTP & ~ifp->if_hwassist) { 615 sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2)); 616 m->m_pkthdr.csum_flags &= ~CSUM_SCTP; 617 } 618 #endif 619 620 /* 621 * If small enough for interface, or the interface will take 622 * care of the fragmentation for us, we can just send directly. 623 */ 624 if (ip_len <= mtu || 625 (m->m_pkthdr.csum_flags & ifp->if_hwassist & CSUM_TSO) != 0 || 626 ((ip_off & IP_DF) == 0 && (ifp->if_hwassist & CSUM_FRAGMENT))) { 627 ip->ip_sum = 0; 628 if (m->m_pkthdr.csum_flags & CSUM_IP & ~ifp->if_hwassist) { 629 ip->ip_sum = in_cksum(m, hlen); 630 m->m_pkthdr.csum_flags &= ~CSUM_IP; 631 } 632 633 /* 634 * Record statistics for this interface address. 635 * With CSUM_TSO the byte/packet count will be slightly 636 * incorrect because we count the IP+TCP headers only 637 * once instead of for every generated packet. 638 */ 639 if (!(flags & IP_FORWARDING) && ia) { 640 if (m->m_pkthdr.csum_flags & CSUM_TSO) 641 counter_u64_add(ia->ia_ifa.ifa_opackets, 642 m->m_pkthdr.len / m->m_pkthdr.tso_segsz); 643 else 644 counter_u64_add(ia->ia_ifa.ifa_opackets, 1); 645 646 counter_u64_add(ia->ia_ifa.ifa_obytes, m->m_pkthdr.len); 647 } 648 #ifdef MBUF_STRESS_TEST 649 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size) 650 m = m_fragment(m, M_NOWAIT, mbuf_frag_size); 651 #endif 652 /* 653 * Reset layer specific mbuf flags 654 * to avoid confusing lower layers. 655 */ 656 m_clrprotoflags(m); 657 IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL); 658 error = (*ifp->if_output)(ifp, m, 659 (const struct sockaddr *)gw, ro); 660 goto done; 661 } 662 663 /* Balk when DF bit is set or the interface didn't support TSO. */ 664 if ((ip_off & IP_DF) || (m->m_pkthdr.csum_flags & CSUM_TSO)) { 665 error = EMSGSIZE; 666 IPSTAT_INC(ips_cantfrag); 667 goto bad; 668 } 669 670 /* 671 * Too large for interface; fragment if possible. If successful, 672 * on return, m will point to a list of packets to be sent. 673 */ 674 error = ip_fragment(ip, &m, mtu, ifp->if_hwassist); 675 if (error) 676 goto bad; 677 for (; m; m = m0) { 678 m0 = m->m_nextpkt; 679 m->m_nextpkt = 0; 680 if (error == 0) { 681 /* Record statistics for this interface address. */ 682 if (ia != NULL) { 683 counter_u64_add(ia->ia_ifa.ifa_opackets, 1); 684 counter_u64_add(ia->ia_ifa.ifa_obytes, 685 m->m_pkthdr.len); 686 } 687 /* 688 * Reset layer specific mbuf flags 689 * to avoid confusing upper layers. 690 */ 691 m_clrprotoflags(m); 692 693 IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL); 694 error = (*ifp->if_output)(ifp, m, 695 (const struct sockaddr *)gw, ro); 696 } else 697 m_freem(m); 698 } 699 700 if (error == 0) 701 IPSTAT_INC(ips_fragmented); 702 703 done: 704 if (ro == &iproute) 705 RO_RTFREE(ro); 706 if (ia != NULL) 707 ifa_free(&ia->ia_ifa); 708 return (error); 709 bad: 710 m_freem(m); 711 goto done; 712 } 713 714 /* 715 * Create a chain of fragments which fit the given mtu. m_frag points to the 716 * mbuf to be fragmented; on return it points to the chain with the fragments. 717 * Return 0 if no error. If error, m_frag may contain a partially built 718 * chain of fragments that should be freed by the caller. 719 * 720 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist) 721 */ 722 int 723 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu, 724 u_long if_hwassist_flags) 725 { 726 int error = 0; 727 int hlen = ip->ip_hl << 2; 728 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */ 729 int off; 730 struct mbuf *m0 = *m_frag; /* the original packet */ 731 int firstlen; 732 struct mbuf **mnext; 733 int nfrags; 734 uint16_t ip_len, ip_off; 735 736 ip_len = ntohs(ip->ip_len); 737 ip_off = ntohs(ip->ip_off); 738 739 if (ip_off & IP_DF) { /* Fragmentation not allowed */ 740 IPSTAT_INC(ips_cantfrag); 741 return EMSGSIZE; 742 } 743 744 /* 745 * Must be able to put at least 8 bytes per fragment. 746 */ 747 if (len < 8) 748 return EMSGSIZE; 749 750 /* 751 * If the interface will not calculate checksums on 752 * fragmented packets, then do it here. 753 */ 754 if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 755 in_delayed_cksum(m0); 756 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 757 } 758 #ifdef SCTP 759 if (m0->m_pkthdr.csum_flags & CSUM_SCTP) { 760 sctp_delayed_cksum(m0, hlen); 761 m0->m_pkthdr.csum_flags &= ~CSUM_SCTP; 762 } 763 #endif 764 if (len > PAGE_SIZE) { 765 /* 766 * Fragment large datagrams such that each segment 767 * contains a multiple of PAGE_SIZE amount of data, 768 * plus headers. This enables a receiver to perform 769 * page-flipping zero-copy optimizations. 770 * 771 * XXX When does this help given that sender and receiver 772 * could have different page sizes, and also mtu could 773 * be less than the receiver's page size ? 774 */ 775 int newlen; 776 struct mbuf *m; 777 778 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next) 779 off += m->m_len; 780 781 /* 782 * firstlen (off - hlen) must be aligned on an 783 * 8-byte boundary 784 */ 785 if (off < hlen) 786 goto smart_frag_failure; 787 off = ((off - hlen) & ~7) + hlen; 788 newlen = (~PAGE_MASK) & mtu; 789 if ((newlen + sizeof (struct ip)) > mtu) { 790 /* we failed, go back the default */ 791 smart_frag_failure: 792 newlen = len; 793 off = hlen + len; 794 } 795 len = newlen; 796 797 } else { 798 off = hlen + len; 799 } 800 801 firstlen = off - hlen; 802 mnext = &m0->m_nextpkt; /* pointer to next packet */ 803 804 /* 805 * Loop through length of segment after first fragment, 806 * make new header and copy data of each part and link onto chain. 807 * Here, m0 is the original packet, m is the fragment being created. 808 * The fragments are linked off the m_nextpkt of the original 809 * packet, which after processing serves as the first fragment. 810 */ 811 for (nfrags = 1; off < ip_len; off += len, nfrags++) { 812 struct ip *mhip; /* ip header on the fragment */ 813 struct mbuf *m; 814 int mhlen = sizeof (struct ip); 815 816 m = m_gethdr(M_NOWAIT, MT_DATA); 817 if (m == NULL) { 818 error = ENOBUFS; 819 IPSTAT_INC(ips_odropped); 820 goto done; 821 } 822 m->m_flags |= (m0->m_flags & M_MCAST); 823 /* 824 * In the first mbuf, leave room for the link header, then 825 * copy the original IP header including options. The payload 826 * goes into an additional mbuf chain returned by m_copym(). 827 */ 828 m->m_data += max_linkhdr; 829 mhip = mtod(m, struct ip *); 830 *mhip = *ip; 831 if (hlen > sizeof (struct ip)) { 832 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 833 mhip->ip_v = IPVERSION; 834 mhip->ip_hl = mhlen >> 2; 835 } 836 m->m_len = mhlen; 837 /* XXX do we need to add ip_off below ? */ 838 mhip->ip_off = ((off - hlen) >> 3) + ip_off; 839 if (off + len >= ip_len) 840 len = ip_len - off; 841 else 842 mhip->ip_off |= IP_MF; 843 mhip->ip_len = htons((u_short)(len + mhlen)); 844 m->m_next = m_copym(m0, off, len, M_NOWAIT); 845 if (m->m_next == NULL) { /* copy failed */ 846 m_free(m); 847 error = ENOBUFS; /* ??? */ 848 IPSTAT_INC(ips_odropped); 849 goto done; 850 } 851 m->m_pkthdr.len = mhlen + len; 852 m->m_pkthdr.rcvif = NULL; 853 #ifdef MAC 854 mac_netinet_fragment(m0, m); 855 #endif 856 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags; 857 mhip->ip_off = htons(mhip->ip_off); 858 mhip->ip_sum = 0; 859 if (m->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) { 860 mhip->ip_sum = in_cksum(m, mhlen); 861 m->m_pkthdr.csum_flags &= ~CSUM_IP; 862 } 863 *mnext = m; 864 mnext = &m->m_nextpkt; 865 } 866 IPSTAT_ADD(ips_ofragments, nfrags); 867 868 /* 869 * Update first fragment by trimming what's been copied out 870 * and updating header. 871 */ 872 m_adj(m0, hlen + firstlen - ip_len); 873 m0->m_pkthdr.len = hlen + firstlen; 874 ip->ip_len = htons((u_short)m0->m_pkthdr.len); 875 ip->ip_off = htons(ip_off | IP_MF); 876 ip->ip_sum = 0; 877 if (m0->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) { 878 ip->ip_sum = in_cksum(m0, hlen); 879 m0->m_pkthdr.csum_flags &= ~CSUM_IP; 880 } 881 882 done: 883 *m_frag = m0; 884 return error; 885 } 886 887 void 888 in_delayed_cksum(struct mbuf *m) 889 { 890 struct ip *ip; 891 uint16_t csum, offset, ip_len; 892 893 ip = mtod(m, struct ip *); 894 offset = ip->ip_hl << 2 ; 895 ip_len = ntohs(ip->ip_len); 896 csum = in_cksum_skip(m, ip_len, offset); 897 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0) 898 csum = 0xffff; 899 offset += m->m_pkthdr.csum_data; /* checksum offset */ 900 901 if (offset + sizeof(u_short) > m->m_len) { 902 printf("delayed m_pullup, m->len: %d off: %d p: %d\n", 903 m->m_len, offset, ip->ip_p); 904 /* 905 * XXX 906 * this shouldn't happen, but if it does, the 907 * correct behavior may be to insert the checksum 908 * in the appropriate next mbuf in the chain. 909 */ 910 return; 911 } 912 *(u_short *)(m->m_data + offset) = csum; 913 } 914 915 /* 916 * IP socket option processing. 917 */ 918 int 919 ip_ctloutput(struct socket *so, struct sockopt *sopt) 920 { 921 struct inpcb *inp = sotoinpcb(so); 922 int error, optval; 923 924 error = optval = 0; 925 if (sopt->sopt_level != IPPROTO_IP) { 926 error = EINVAL; 927 928 if (sopt->sopt_level == SOL_SOCKET && 929 sopt->sopt_dir == SOPT_SET) { 930 switch (sopt->sopt_name) { 931 case SO_REUSEADDR: 932 INP_WLOCK(inp); 933 if ((so->so_options & SO_REUSEADDR) != 0) 934 inp->inp_flags2 |= INP_REUSEADDR; 935 else 936 inp->inp_flags2 &= ~INP_REUSEADDR; 937 INP_WUNLOCK(inp); 938 error = 0; 939 break; 940 case SO_REUSEPORT: 941 INP_WLOCK(inp); 942 if ((so->so_options & SO_REUSEPORT) != 0) 943 inp->inp_flags2 |= INP_REUSEPORT; 944 else 945 inp->inp_flags2 &= ~INP_REUSEPORT; 946 INP_WUNLOCK(inp); 947 error = 0; 948 break; 949 case SO_SETFIB: 950 INP_WLOCK(inp); 951 inp->inp_inc.inc_fibnum = so->so_fibnum; 952 INP_WUNLOCK(inp); 953 error = 0; 954 break; 955 default: 956 break; 957 } 958 } 959 return (error); 960 } 961 962 switch (sopt->sopt_dir) { 963 case SOPT_SET: 964 switch (sopt->sopt_name) { 965 case IP_OPTIONS: 966 #ifdef notyet 967 case IP_RETOPTS: 968 #endif 969 { 970 struct mbuf *m; 971 if (sopt->sopt_valsize > MLEN) { 972 error = EMSGSIZE; 973 break; 974 } 975 m = m_get(sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA); 976 if (m == NULL) { 977 error = ENOBUFS; 978 break; 979 } 980 m->m_len = sopt->sopt_valsize; 981 error = sooptcopyin(sopt, mtod(m, char *), m->m_len, 982 m->m_len); 983 if (error) { 984 m_free(m); 985 break; 986 } 987 INP_WLOCK(inp); 988 error = ip_pcbopts(inp, sopt->sopt_name, m); 989 INP_WUNLOCK(inp); 990 return (error); 991 } 992 993 case IP_BINDANY: 994 if (sopt->sopt_td != NULL) { 995 error = priv_check(sopt->sopt_td, 996 PRIV_NETINET_BINDANY); 997 if (error) 998 break; 999 } 1000 /* FALLTHROUGH */ 1001 case IP_TOS: 1002 case IP_TTL: 1003 case IP_MINTTL: 1004 case IP_RECVOPTS: 1005 case IP_RECVRETOPTS: 1006 case IP_RECVDSTADDR: 1007 case IP_RECVTTL: 1008 case IP_RECVIF: 1009 case IP_FAITH: 1010 case IP_ONESBCAST: 1011 case IP_DONTFRAG: 1012 case IP_RECVTOS: 1013 error = sooptcopyin(sopt, &optval, sizeof optval, 1014 sizeof optval); 1015 if (error) 1016 break; 1017 1018 switch (sopt->sopt_name) { 1019 case IP_TOS: 1020 inp->inp_ip_tos = optval; 1021 break; 1022 1023 case IP_TTL: 1024 inp->inp_ip_ttl = optval; 1025 break; 1026 1027 case IP_MINTTL: 1028 if (optval >= 0 && optval <= MAXTTL) 1029 inp->inp_ip_minttl = optval; 1030 else 1031 error = EINVAL; 1032 break; 1033 1034 #define OPTSET(bit) do { \ 1035 INP_WLOCK(inp); \ 1036 if (optval) \ 1037 inp->inp_flags |= bit; \ 1038 else \ 1039 inp->inp_flags &= ~bit; \ 1040 INP_WUNLOCK(inp); \ 1041 } while (0) 1042 1043 case IP_RECVOPTS: 1044 OPTSET(INP_RECVOPTS); 1045 break; 1046 1047 case IP_RECVRETOPTS: 1048 OPTSET(INP_RECVRETOPTS); 1049 break; 1050 1051 case IP_RECVDSTADDR: 1052 OPTSET(INP_RECVDSTADDR); 1053 break; 1054 1055 case IP_RECVTTL: 1056 OPTSET(INP_RECVTTL); 1057 break; 1058 1059 case IP_RECVIF: 1060 OPTSET(INP_RECVIF); 1061 break; 1062 1063 case IP_FAITH: 1064 OPTSET(INP_FAITH); 1065 break; 1066 1067 case IP_ONESBCAST: 1068 OPTSET(INP_ONESBCAST); 1069 break; 1070 case IP_DONTFRAG: 1071 OPTSET(INP_DONTFRAG); 1072 break; 1073 case IP_BINDANY: 1074 OPTSET(INP_BINDANY); 1075 break; 1076 case IP_RECVTOS: 1077 OPTSET(INP_RECVTOS); 1078 break; 1079 } 1080 break; 1081 #undef OPTSET 1082 1083 /* 1084 * Multicast socket options are processed by the in_mcast 1085 * module. 1086 */ 1087 case IP_MULTICAST_IF: 1088 case IP_MULTICAST_VIF: 1089 case IP_MULTICAST_TTL: 1090 case IP_MULTICAST_LOOP: 1091 case IP_ADD_MEMBERSHIP: 1092 case IP_DROP_MEMBERSHIP: 1093 case IP_ADD_SOURCE_MEMBERSHIP: 1094 case IP_DROP_SOURCE_MEMBERSHIP: 1095 case IP_BLOCK_SOURCE: 1096 case IP_UNBLOCK_SOURCE: 1097 case IP_MSFILTER: 1098 case MCAST_JOIN_GROUP: 1099 case MCAST_LEAVE_GROUP: 1100 case MCAST_JOIN_SOURCE_GROUP: 1101 case MCAST_LEAVE_SOURCE_GROUP: 1102 case MCAST_BLOCK_SOURCE: 1103 case MCAST_UNBLOCK_SOURCE: 1104 error = inp_setmoptions(inp, sopt); 1105 break; 1106 1107 case IP_PORTRANGE: 1108 error = sooptcopyin(sopt, &optval, sizeof optval, 1109 sizeof optval); 1110 if (error) 1111 break; 1112 1113 INP_WLOCK(inp); 1114 switch (optval) { 1115 case IP_PORTRANGE_DEFAULT: 1116 inp->inp_flags &= ~(INP_LOWPORT); 1117 inp->inp_flags &= ~(INP_HIGHPORT); 1118 break; 1119 1120 case IP_PORTRANGE_HIGH: 1121 inp->inp_flags &= ~(INP_LOWPORT); 1122 inp->inp_flags |= INP_HIGHPORT; 1123 break; 1124 1125 case IP_PORTRANGE_LOW: 1126 inp->inp_flags &= ~(INP_HIGHPORT); 1127 inp->inp_flags |= INP_LOWPORT; 1128 break; 1129 1130 default: 1131 error = EINVAL; 1132 break; 1133 } 1134 INP_WUNLOCK(inp); 1135 break; 1136 1137 #ifdef IPSEC 1138 case IP_IPSEC_POLICY: 1139 { 1140 caddr_t req; 1141 struct mbuf *m; 1142 1143 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */ 1144 break; 1145 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */ 1146 break; 1147 req = mtod(m, caddr_t); 1148 error = ipsec_set_policy(inp, sopt->sopt_name, req, 1149 m->m_len, (sopt->sopt_td != NULL) ? 1150 sopt->sopt_td->td_ucred : NULL); 1151 m_freem(m); 1152 break; 1153 } 1154 #endif /* IPSEC */ 1155 1156 default: 1157 error = ENOPROTOOPT; 1158 break; 1159 } 1160 break; 1161 1162 case SOPT_GET: 1163 switch (sopt->sopt_name) { 1164 case IP_OPTIONS: 1165 case IP_RETOPTS: 1166 if (inp->inp_options) 1167 error = sooptcopyout(sopt, 1168 mtod(inp->inp_options, 1169 char *), 1170 inp->inp_options->m_len); 1171 else 1172 sopt->sopt_valsize = 0; 1173 break; 1174 1175 case IP_TOS: 1176 case IP_TTL: 1177 case IP_MINTTL: 1178 case IP_RECVOPTS: 1179 case IP_RECVRETOPTS: 1180 case IP_RECVDSTADDR: 1181 case IP_RECVTTL: 1182 case IP_RECVIF: 1183 case IP_PORTRANGE: 1184 case IP_FAITH: 1185 case IP_ONESBCAST: 1186 case IP_DONTFRAG: 1187 case IP_BINDANY: 1188 case IP_RECVTOS: 1189 switch (sopt->sopt_name) { 1190 1191 case IP_TOS: 1192 optval = inp->inp_ip_tos; 1193 break; 1194 1195 case IP_TTL: 1196 optval = inp->inp_ip_ttl; 1197 break; 1198 1199 case IP_MINTTL: 1200 optval = inp->inp_ip_minttl; 1201 break; 1202 1203 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1204 1205 case IP_RECVOPTS: 1206 optval = OPTBIT(INP_RECVOPTS); 1207 break; 1208 1209 case IP_RECVRETOPTS: 1210 optval = OPTBIT(INP_RECVRETOPTS); 1211 break; 1212 1213 case IP_RECVDSTADDR: 1214 optval = OPTBIT(INP_RECVDSTADDR); 1215 break; 1216 1217 case IP_RECVTTL: 1218 optval = OPTBIT(INP_RECVTTL); 1219 break; 1220 1221 case IP_RECVIF: 1222 optval = OPTBIT(INP_RECVIF); 1223 break; 1224 1225 case IP_PORTRANGE: 1226 if (inp->inp_flags & INP_HIGHPORT) 1227 optval = IP_PORTRANGE_HIGH; 1228 else if (inp->inp_flags & INP_LOWPORT) 1229 optval = IP_PORTRANGE_LOW; 1230 else 1231 optval = 0; 1232 break; 1233 1234 case IP_FAITH: 1235 optval = OPTBIT(INP_FAITH); 1236 break; 1237 1238 case IP_ONESBCAST: 1239 optval = OPTBIT(INP_ONESBCAST); 1240 break; 1241 case IP_DONTFRAG: 1242 optval = OPTBIT(INP_DONTFRAG); 1243 break; 1244 case IP_BINDANY: 1245 optval = OPTBIT(INP_BINDANY); 1246 break; 1247 case IP_RECVTOS: 1248 optval = OPTBIT(INP_RECVTOS); 1249 break; 1250 } 1251 error = sooptcopyout(sopt, &optval, sizeof optval); 1252 break; 1253 1254 /* 1255 * Multicast socket options are processed by the in_mcast 1256 * module. 1257 */ 1258 case IP_MULTICAST_IF: 1259 case IP_MULTICAST_VIF: 1260 case IP_MULTICAST_TTL: 1261 case IP_MULTICAST_LOOP: 1262 case IP_MSFILTER: 1263 error = inp_getmoptions(inp, sopt); 1264 break; 1265 1266 #ifdef IPSEC 1267 case IP_IPSEC_POLICY: 1268 { 1269 struct mbuf *m = NULL; 1270 caddr_t req = NULL; 1271 size_t len = 0; 1272 1273 if (m != 0) { 1274 req = mtod(m, caddr_t); 1275 len = m->m_len; 1276 } 1277 error = ipsec_get_policy(sotoinpcb(so), req, len, &m); 1278 if (error == 0) 1279 error = soopt_mcopyout(sopt, m); /* XXX */ 1280 if (error == 0) 1281 m_freem(m); 1282 break; 1283 } 1284 #endif /* IPSEC */ 1285 1286 default: 1287 error = ENOPROTOOPT; 1288 break; 1289 } 1290 break; 1291 } 1292 return (error); 1293 } 1294 1295 /* 1296 * Routine called from ip_output() to loop back a copy of an IP multicast 1297 * packet to the input queue of a specified interface. Note that this 1298 * calls the output routine of the loopback "driver", but with an interface 1299 * pointer that might NOT be a loopback interface -- evil, but easier than 1300 * replicating that code here. 1301 */ 1302 static void 1303 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst, 1304 int hlen) 1305 { 1306 register struct ip *ip; 1307 struct mbuf *copym; 1308 1309 /* 1310 * Make a deep copy of the packet because we're going to 1311 * modify the pack in order to generate checksums. 1312 */ 1313 copym = m_dup(m, M_NOWAIT); 1314 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen)) 1315 copym = m_pullup(copym, hlen); 1316 if (copym != NULL) { 1317 /* If needed, compute the checksum and mark it as valid. */ 1318 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 1319 in_delayed_cksum(copym); 1320 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 1321 copym->m_pkthdr.csum_flags |= 1322 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 1323 copym->m_pkthdr.csum_data = 0xffff; 1324 } 1325 /* 1326 * We don't bother to fragment if the IP length is greater 1327 * than the interface's MTU. Can this possibly matter? 1328 */ 1329 ip = mtod(copym, struct ip *); 1330 ip->ip_sum = 0; 1331 ip->ip_sum = in_cksum(copym, hlen); 1332 #if 1 /* XXX */ 1333 if (dst->sin_family != AF_INET) { 1334 printf("ip_mloopback: bad address family %d\n", 1335 dst->sin_family); 1336 dst->sin_family = AF_INET; 1337 } 1338 #endif 1339 if_simloop(ifp, copym, dst->sin_family, 0); 1340 } 1341 } 1342