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 uint32_t fibnum; 140 int have_ia_ref; 141 int needfiblookup; 142 #ifdef IPSEC 143 int no_route_but_check_spd = 0; 144 #endif 145 M_ASSERTPKTHDR(m); 146 147 if (inp != NULL) { 148 INP_LOCK_ASSERT(inp); 149 M_SETFIB(m, inp->inp_inc.inc_fibnum); 150 if ((flags & IP_NODEFAULTFLOWID) == 0) { 151 m->m_pkthdr.flowid = inp->inp_flowid; 152 M_HASHTYPE_SET(m, inp->inp_flowtype); 153 } 154 } 155 156 if (ro == NULL) { 157 ro = &iproute; 158 bzero(ro, sizeof (*ro)); 159 } 160 161 #ifdef FLOWTABLE 162 if (ro->ro_rt == NULL) 163 (void )flowtable_lookup(AF_INET, m, ro); 164 #endif 165 166 if (opt) { 167 int len = 0; 168 m = ip_insertoptions(m, opt, &len); 169 if (len != 0) 170 hlen = len; /* ip->ip_hl is updated above */ 171 } 172 ip = mtod(m, struct ip *); 173 ip_len = ntohs(ip->ip_len); 174 ip_off = ntohs(ip->ip_off); 175 176 /* 177 * Fill in IP header. If we are not allowing fragmentation, 178 * then the ip_id field is meaningless, but we don't set it 179 * to zero. Doing so causes various problems when devices along 180 * the path (routers, load balancers, firewalls, etc.) illegally 181 * disable DF on our packet. Note that a 16-bit counter 182 * will wrap around in less than 10 seconds at 100 Mbit/s on a 183 * medium with MTU 1500. See Steven M. Bellovin, "A Technique 184 * for Counting NATted Hosts", Proc. IMW'02, available at 185 * <http://www.cs.columbia.edu/~smb/papers/fnat.pdf>. 186 */ 187 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 188 ip->ip_v = IPVERSION; 189 ip->ip_hl = hlen >> 2; 190 ip->ip_id = ip_newid(); 191 IPSTAT_INC(ips_localout); 192 } else { 193 /* Header already set, fetch hlen from there */ 194 hlen = ip->ip_hl << 2; 195 } 196 197 /* 198 * dst/gw handling: 199 * 200 * dst can be rewritten but always points to &ro->ro_dst. 201 * gw is readonly but can point either to dst OR rt_gateway, 202 * therefore we need restore gw if we're redoing lookup. 203 */ 204 gw = dst = (struct sockaddr_in *)&ro->ro_dst; 205 fibnum = (inp != NULL) ? inp->inp_inc.inc_fibnum : M_GETFIB(m); 206 again: 207 ia = NULL; 208 have_ia_ref = 0; 209 /* 210 * If there is a cached route, check that it is to the same 211 * destination and is still up. If not, free it and try again. 212 * The address family should also be checked in case of sharing 213 * the 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 gw = dst; 225 } 226 if (rte == NULL && fwd_tag == NULL) { 227 bzero(dst, sizeof(*dst)); 228 dst->sin_family = AF_INET; 229 dst->sin_len = sizeof(*dst); 230 dst->sin_addr = ip->ip_dst; 231 } 232 /* 233 * If routing to interface only, short circuit routing lookup. 234 * The use of an all-ones broadcast address implies this; an 235 * interface is specified by the broadcast address of an interface, 236 * or the destination address of a ptp interface. 237 */ 238 if (flags & IP_SENDONES) { 239 if ((ia = ifatoia(ifa_ifwithbroadaddr(sintosa(dst), 240 M_GETFIB(m)))) == NULL && 241 (ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst), 242 M_GETFIB(m)))) == NULL) { 243 IPSTAT_INC(ips_noroute); 244 error = ENETUNREACH; 245 goto bad; 246 } 247 have_ia_ref = 1; 248 ip->ip_dst.s_addr = INADDR_BROADCAST; 249 dst->sin_addr = ip->ip_dst; 250 ifp = ia->ia_ifp; 251 ip->ip_ttl = 1; 252 isbroadcast = 1; 253 } else if (flags & IP_ROUTETOIF) { 254 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst), 255 M_GETFIB(m)))) == NULL && 256 (ia = ifatoia(ifa_ifwithnet(sintosa(dst), 0, 257 M_GETFIB(m)))) == NULL) { 258 IPSTAT_INC(ips_noroute); 259 error = ENETUNREACH; 260 goto bad; 261 } 262 have_ia_ref = 1; 263 ifp = ia->ia_ifp; 264 ip->ip_ttl = 1; 265 isbroadcast = in_broadcast(dst->sin_addr, ifp); 266 } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) && 267 imo != NULL && imo->imo_multicast_ifp != NULL) { 268 /* 269 * Bypass the normal routing lookup for multicast 270 * packets if the interface is specified. 271 */ 272 ifp = imo->imo_multicast_ifp; 273 IFP_TO_IA(ifp, ia); 274 if (ia) 275 have_ia_ref = 1; 276 isbroadcast = 0; /* fool gcc */ 277 } else { 278 /* 279 * We want to do any cloning requested by the link layer, 280 * as this is probably required in all cases for correct 281 * operation (as it is for ARP). 282 */ 283 if (rte == NULL) { 284 #ifdef RADIX_MPATH 285 rtalloc_mpath_fib(ro, 286 ntohl(ip->ip_src.s_addr ^ ip->ip_dst.s_addr), 287 fibnum); 288 #else 289 in_rtalloc_ign(ro, 0, fibnum); 290 #endif 291 rte = ro->ro_rt; 292 } 293 if (rte == NULL || 294 rte->rt_ifp == NULL || 295 !RT_LINK_IS_UP(rte->rt_ifp)) { 296 #ifdef IPSEC 297 /* 298 * There is no route for this packet, but it is 299 * possible that a matching SPD entry exists. 300 */ 301 no_route_but_check_spd = 1; 302 mtu = 0; /* Silence GCC warning. */ 303 goto sendit; 304 #endif 305 IPSTAT_INC(ips_noroute); 306 error = EHOSTUNREACH; 307 goto bad; 308 } 309 ia = ifatoia(rte->rt_ifa); 310 ifp = rte->rt_ifp; 311 counter_u64_add(rte->rt_pksent, 1); 312 if (rte->rt_flags & RTF_GATEWAY) 313 gw = (struct sockaddr_in *)rte->rt_gateway; 314 if (rte->rt_flags & RTF_HOST) 315 isbroadcast = (rte->rt_flags & RTF_BROADCAST); 316 else 317 isbroadcast = in_broadcast(gw->sin_addr, ifp); 318 } 319 /* 320 * Calculate MTU. If we have a route that is up, use that, 321 * otherwise use the interface's MTU. 322 */ 323 if (rte != NULL && (rte->rt_flags & (RTF_UP|RTF_HOST))) 324 mtu = rte->rt_mtu; 325 else 326 mtu = ifp->if_mtu; 327 /* Catch a possible divide by zero later. */ 328 KASSERT(mtu > 0, ("%s: mtu %d <= 0, rte=%p (rt_flags=0x%08x) ifp=%p", 329 __func__, mtu, rte, (rte != NULL) ? rte->rt_flags : 0, ifp)); 330 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) { 331 m->m_flags |= M_MCAST; 332 /* 333 * IP destination address is multicast. Make sure "gw" 334 * still points to the address in "ro". (It may have been 335 * changed to point to a gateway address, above.) 336 */ 337 gw = dst; 338 /* 339 * See if the caller provided any multicast options 340 */ 341 if (imo != NULL) { 342 ip->ip_ttl = imo->imo_multicast_ttl; 343 if (imo->imo_multicast_vif != -1) 344 ip->ip_src.s_addr = 345 ip_mcast_src ? 346 ip_mcast_src(imo->imo_multicast_vif) : 347 INADDR_ANY; 348 } else 349 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 350 /* 351 * Confirm that the outgoing interface supports multicast. 352 */ 353 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) { 354 if ((ifp->if_flags & IFF_MULTICAST) == 0) { 355 IPSTAT_INC(ips_noroute); 356 error = ENETUNREACH; 357 goto bad; 358 } 359 } 360 /* 361 * If source address not specified yet, use address 362 * of outgoing interface. 363 */ 364 if (ip->ip_src.s_addr == INADDR_ANY) { 365 /* Interface may have no addresses. */ 366 if (ia != NULL) 367 ip->ip_src = IA_SIN(ia)->sin_addr; 368 } 369 370 if ((imo == NULL && in_mcast_loop) || 371 (imo && imo->imo_multicast_loop)) { 372 /* 373 * Loop back multicast datagram if not expressly 374 * forbidden to do so, even if we are not a member 375 * of the group; ip_input() will filter it later, 376 * thus deferring a hash lookup and mutex acquisition 377 * at the expense of a cheap copy using m_copym(). 378 */ 379 ip_mloopback(ifp, m, dst, hlen); 380 } else { 381 /* 382 * If we are acting as a multicast router, perform 383 * multicast forwarding as if the packet had just 384 * arrived on the interface to which we are about 385 * to send. The multicast forwarding function 386 * recursively calls this function, using the 387 * IP_FORWARDING flag to prevent infinite recursion. 388 * 389 * Multicasts that are looped back by ip_mloopback(), 390 * above, will be forwarded by the ip_input() routine, 391 * if necessary. 392 */ 393 if (V_ip_mrouter && (flags & IP_FORWARDING) == 0) { 394 /* 395 * If rsvp daemon is not running, do not 396 * set ip_moptions. This ensures that the packet 397 * is multicast and not just sent down one link 398 * as prescribed by rsvpd. 399 */ 400 if (!V_rsvp_on) 401 imo = NULL; 402 if (ip_mforward && 403 ip_mforward(ip, ifp, m, imo) != 0) { 404 m_freem(m); 405 goto done; 406 } 407 } 408 } 409 410 /* 411 * Multicasts with a time-to-live of zero may be looped- 412 * back, above, but must not be transmitted on a network. 413 * Also, multicasts addressed to the loopback interface 414 * are not sent -- the above call to ip_mloopback() will 415 * loop back a copy. ip_input() will drop the copy if 416 * this host does not belong to the destination group on 417 * the loopback interface. 418 */ 419 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) { 420 m_freem(m); 421 goto done; 422 } 423 424 goto sendit; 425 } 426 427 /* 428 * If the source address is not specified yet, use the address 429 * of the outoing interface. 430 */ 431 if (ip->ip_src.s_addr == INADDR_ANY) { 432 /* Interface may have no addresses. */ 433 if (ia != NULL) { 434 ip->ip_src = IA_SIN(ia)->sin_addr; 435 } 436 } 437 438 /* 439 * Look for broadcast address and 440 * verify user is allowed to send 441 * such a packet. 442 */ 443 if (isbroadcast) { 444 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 445 error = EADDRNOTAVAIL; 446 goto bad; 447 } 448 if ((flags & IP_ALLOWBROADCAST) == 0) { 449 error = EACCES; 450 goto bad; 451 } 452 /* don't allow broadcast messages to be fragmented */ 453 if (ip_len > mtu) { 454 error = EMSGSIZE; 455 goto bad; 456 } 457 m->m_flags |= M_BCAST; 458 } else { 459 m->m_flags &= ~M_BCAST; 460 } 461 462 sendit: 463 #ifdef IPSEC 464 switch(ip_ipsec_output(&m, inp, &error)) { 465 case 1: 466 goto bad; 467 case -1: 468 goto done; 469 case 0: 470 default: 471 break; /* Continue with packet processing. */ 472 } 473 /* 474 * Check if there was a route for this packet; return error if not. 475 */ 476 if (no_route_but_check_spd) { 477 IPSTAT_INC(ips_noroute); 478 error = EHOSTUNREACH; 479 goto bad; 480 } 481 /* Update variables that are affected by ipsec4_output(). */ 482 ip = mtod(m, struct ip *); 483 hlen = ip->ip_hl << 2; 484 #endif /* IPSEC */ 485 486 /* Jump over all PFIL processing if hooks are not active. */ 487 if (!PFIL_HOOKED(&V_inet_pfil_hook)) 488 goto passout; 489 490 /* Run through list of hooks for output packets. */ 491 odst.s_addr = ip->ip_dst.s_addr; 492 error = pfil_run_hooks(&V_inet_pfil_hook, &m, ifp, PFIL_OUT, inp); 493 if (error != 0 || m == NULL) 494 goto done; 495 496 ip = mtod(m, struct ip *); 497 needfiblookup = 0; 498 499 /* See if destination IP address was changed by packet filter. */ 500 if (odst.s_addr != ip->ip_dst.s_addr) { 501 m->m_flags |= M_SKIP_FIREWALL; 502 /* If destination is now ourself drop to ip_input(). */ 503 if (in_localip(ip->ip_dst)) { 504 m->m_flags |= M_FASTFWD_OURS; 505 if (m->m_pkthdr.rcvif == NULL) 506 m->m_pkthdr.rcvif = V_loif; 507 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 508 m->m_pkthdr.csum_flags |= 509 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 510 m->m_pkthdr.csum_data = 0xffff; 511 } 512 m->m_pkthdr.csum_flags |= 513 CSUM_IP_CHECKED | CSUM_IP_VALID; 514 #ifdef SCTP 515 if (m->m_pkthdr.csum_flags & CSUM_SCTP) 516 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID; 517 #endif 518 error = netisr_queue(NETISR_IP, m); 519 goto done; 520 } else { 521 if (have_ia_ref) 522 ifa_free(&ia->ia_ifa); 523 needfiblookup = 1; /* Redo the routing table lookup. */ 524 } 525 } 526 /* See if fib was changed by packet filter. */ 527 if (fibnum != M_GETFIB(m)) { 528 m->m_flags |= M_SKIP_FIREWALL; 529 fibnum = M_GETFIB(m); 530 RO_RTFREE(ro); 531 needfiblookup = 1; 532 } 533 if (needfiblookup) 534 goto again; 535 536 /* See if local, if yes, send it to netisr with IP_FASTFWD_OURS. */ 537 if (m->m_flags & M_FASTFWD_OURS) { 538 if (m->m_pkthdr.rcvif == NULL) 539 m->m_pkthdr.rcvif = V_loif; 540 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 541 m->m_pkthdr.csum_flags |= 542 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 543 m->m_pkthdr.csum_data = 0xffff; 544 } 545 #ifdef SCTP 546 if (m->m_pkthdr.csum_flags & CSUM_SCTP) 547 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID; 548 #endif 549 m->m_pkthdr.csum_flags |= 550 CSUM_IP_CHECKED | CSUM_IP_VALID; 551 552 error = netisr_queue(NETISR_IP, m); 553 goto done; 554 } 555 /* Or forward to some other address? */ 556 if ((m->m_flags & M_IP_NEXTHOP) && 557 (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) { 558 bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in)); 559 m->m_flags |= M_SKIP_FIREWALL; 560 m->m_flags &= ~M_IP_NEXTHOP; 561 m_tag_delete(m, fwd_tag); 562 if (have_ia_ref) 563 ifa_free(&ia->ia_ifa); 564 goto again; 565 } 566 567 passout: 568 /* 127/8 must not appear on wire - RFC1122. */ 569 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET || 570 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) { 571 if ((ifp->if_flags & IFF_LOOPBACK) == 0) { 572 IPSTAT_INC(ips_badaddr); 573 error = EADDRNOTAVAIL; 574 goto bad; 575 } 576 } 577 578 m->m_pkthdr.csum_flags |= CSUM_IP; 579 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA & ~ifp->if_hwassist) { 580 in_delayed_cksum(m); 581 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 582 } 583 #ifdef SCTP 584 if (m->m_pkthdr.csum_flags & CSUM_SCTP & ~ifp->if_hwassist) { 585 sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2)); 586 m->m_pkthdr.csum_flags &= ~CSUM_SCTP; 587 } 588 #endif 589 590 /* 591 * If small enough for interface, or the interface will take 592 * care of the fragmentation for us, we can just send directly. 593 */ 594 if (ip_len <= mtu || 595 (m->m_pkthdr.csum_flags & ifp->if_hwassist & CSUM_TSO) != 0) { 596 ip->ip_sum = 0; 597 if (m->m_pkthdr.csum_flags & CSUM_IP & ~ifp->if_hwassist) { 598 ip->ip_sum = in_cksum(m, hlen); 599 m->m_pkthdr.csum_flags &= ~CSUM_IP; 600 } 601 602 /* 603 * Record statistics for this interface address. 604 * With CSUM_TSO the byte/packet count will be slightly 605 * incorrect because we count the IP+TCP headers only 606 * once instead of for every generated packet. 607 */ 608 if (!(flags & IP_FORWARDING) && ia) { 609 if (m->m_pkthdr.csum_flags & CSUM_TSO) 610 counter_u64_add(ia->ia_ifa.ifa_opackets, 611 m->m_pkthdr.len / m->m_pkthdr.tso_segsz); 612 else 613 counter_u64_add(ia->ia_ifa.ifa_opackets, 1); 614 615 counter_u64_add(ia->ia_ifa.ifa_obytes, m->m_pkthdr.len); 616 } 617 #ifdef MBUF_STRESS_TEST 618 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size) 619 m = m_fragment(m, M_NOWAIT, mbuf_frag_size); 620 #endif 621 /* 622 * Reset layer specific mbuf flags 623 * to avoid confusing lower layers. 624 */ 625 m_clrprotoflags(m); 626 IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL); 627 error = (*ifp->if_output)(ifp, m, 628 (const struct sockaddr *)gw, ro); 629 goto done; 630 } 631 632 /* Balk when DF bit is set or the interface didn't support TSO. */ 633 if ((ip_off & IP_DF) || (m->m_pkthdr.csum_flags & CSUM_TSO)) { 634 error = EMSGSIZE; 635 IPSTAT_INC(ips_cantfrag); 636 goto bad; 637 } 638 639 /* 640 * Too large for interface; fragment if possible. If successful, 641 * on return, m will point to a list of packets to be sent. 642 */ 643 error = ip_fragment(ip, &m, mtu, ifp->if_hwassist); 644 if (error) 645 goto bad; 646 for (; m; m = m0) { 647 m0 = m->m_nextpkt; 648 m->m_nextpkt = 0; 649 if (error == 0) { 650 /* Record statistics for this interface address. */ 651 if (ia != NULL) { 652 counter_u64_add(ia->ia_ifa.ifa_opackets, 1); 653 counter_u64_add(ia->ia_ifa.ifa_obytes, 654 m->m_pkthdr.len); 655 } 656 /* 657 * Reset layer specific mbuf flags 658 * to avoid confusing upper layers. 659 */ 660 m_clrprotoflags(m); 661 662 IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL); 663 error = (*ifp->if_output)(ifp, m, 664 (const struct sockaddr *)gw, ro); 665 } else 666 m_freem(m); 667 } 668 669 if (error == 0) 670 IPSTAT_INC(ips_fragmented); 671 672 done: 673 if (ro == &iproute) 674 RO_RTFREE(ro); 675 if (have_ia_ref) 676 ifa_free(&ia->ia_ifa); 677 return (error); 678 bad: 679 m_freem(m); 680 goto done; 681 } 682 683 /* 684 * Create a chain of fragments which fit the given mtu. m_frag points to the 685 * mbuf to be fragmented; on return it points to the chain with the fragments. 686 * Return 0 if no error. If error, m_frag may contain a partially built 687 * chain of fragments that should be freed by the caller. 688 * 689 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist) 690 */ 691 int 692 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu, 693 u_long if_hwassist_flags) 694 { 695 int error = 0; 696 int hlen = ip->ip_hl << 2; 697 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */ 698 int off; 699 struct mbuf *m0 = *m_frag; /* the original packet */ 700 int firstlen; 701 struct mbuf **mnext; 702 int nfrags; 703 uint16_t ip_len, ip_off; 704 705 ip_len = ntohs(ip->ip_len); 706 ip_off = ntohs(ip->ip_off); 707 708 if (ip_off & IP_DF) { /* Fragmentation not allowed */ 709 IPSTAT_INC(ips_cantfrag); 710 return EMSGSIZE; 711 } 712 713 /* 714 * Must be able to put at least 8 bytes per fragment. 715 */ 716 if (len < 8) 717 return EMSGSIZE; 718 719 /* 720 * If the interface will not calculate checksums on 721 * fragmented packets, then do it here. 722 */ 723 if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 724 in_delayed_cksum(m0); 725 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 726 } 727 #ifdef SCTP 728 if (m0->m_pkthdr.csum_flags & CSUM_SCTP) { 729 sctp_delayed_cksum(m0, hlen); 730 m0->m_pkthdr.csum_flags &= ~CSUM_SCTP; 731 } 732 #endif 733 if (len > PAGE_SIZE) { 734 /* 735 * Fragment large datagrams such that each segment 736 * contains a multiple of PAGE_SIZE amount of data, 737 * plus headers. This enables a receiver to perform 738 * page-flipping zero-copy optimizations. 739 * 740 * XXX When does this help given that sender and receiver 741 * could have different page sizes, and also mtu could 742 * be less than the receiver's page size ? 743 */ 744 int newlen; 745 struct mbuf *m; 746 747 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next) 748 off += m->m_len; 749 750 /* 751 * firstlen (off - hlen) must be aligned on an 752 * 8-byte boundary 753 */ 754 if (off < hlen) 755 goto smart_frag_failure; 756 off = ((off - hlen) & ~7) + hlen; 757 newlen = (~PAGE_MASK) & mtu; 758 if ((newlen + sizeof (struct ip)) > mtu) { 759 /* we failed, go back the default */ 760 smart_frag_failure: 761 newlen = len; 762 off = hlen + len; 763 } 764 len = newlen; 765 766 } else { 767 off = hlen + len; 768 } 769 770 firstlen = off - hlen; 771 mnext = &m0->m_nextpkt; /* pointer to next packet */ 772 773 /* 774 * Loop through length of segment after first fragment, 775 * make new header and copy data of each part and link onto chain. 776 * Here, m0 is the original packet, m is the fragment being created. 777 * The fragments are linked off the m_nextpkt of the original 778 * packet, which after processing serves as the first fragment. 779 */ 780 for (nfrags = 1; off < ip_len; off += len, nfrags++) { 781 struct ip *mhip; /* ip header on the fragment */ 782 struct mbuf *m; 783 int mhlen = sizeof (struct ip); 784 785 m = m_gethdr(M_NOWAIT, MT_DATA); 786 if (m == NULL) { 787 error = ENOBUFS; 788 IPSTAT_INC(ips_odropped); 789 goto done; 790 } 791 m->m_flags |= (m0->m_flags & M_MCAST); 792 /* 793 * In the first mbuf, leave room for the link header, then 794 * copy the original IP header including options. The payload 795 * goes into an additional mbuf chain returned by m_copym(). 796 */ 797 m->m_data += max_linkhdr; 798 mhip = mtod(m, struct ip *); 799 *mhip = *ip; 800 if (hlen > sizeof (struct ip)) { 801 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 802 mhip->ip_v = IPVERSION; 803 mhip->ip_hl = mhlen >> 2; 804 } 805 m->m_len = mhlen; 806 /* XXX do we need to add ip_off below ? */ 807 mhip->ip_off = ((off - hlen) >> 3) + ip_off; 808 if (off + len >= ip_len) 809 len = ip_len - off; 810 else 811 mhip->ip_off |= IP_MF; 812 mhip->ip_len = htons((u_short)(len + mhlen)); 813 m->m_next = m_copym(m0, off, len, M_NOWAIT); 814 if (m->m_next == NULL) { /* copy failed */ 815 m_free(m); 816 error = ENOBUFS; /* ??? */ 817 IPSTAT_INC(ips_odropped); 818 goto done; 819 } 820 m->m_pkthdr.len = mhlen + len; 821 m->m_pkthdr.rcvif = NULL; 822 #ifdef MAC 823 mac_netinet_fragment(m0, m); 824 #endif 825 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags; 826 mhip->ip_off = htons(mhip->ip_off); 827 mhip->ip_sum = 0; 828 if (m->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) { 829 mhip->ip_sum = in_cksum(m, mhlen); 830 m->m_pkthdr.csum_flags &= ~CSUM_IP; 831 } 832 *mnext = m; 833 mnext = &m->m_nextpkt; 834 } 835 IPSTAT_ADD(ips_ofragments, nfrags); 836 837 /* 838 * Update first fragment by trimming what's been copied out 839 * and updating header. 840 */ 841 m_adj(m0, hlen + firstlen - ip_len); 842 m0->m_pkthdr.len = hlen + firstlen; 843 ip->ip_len = htons((u_short)m0->m_pkthdr.len); 844 ip->ip_off = htons(ip_off | IP_MF); 845 ip->ip_sum = 0; 846 if (m0->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) { 847 ip->ip_sum = in_cksum(m0, hlen); 848 m0->m_pkthdr.csum_flags &= ~CSUM_IP; 849 } 850 851 done: 852 *m_frag = m0; 853 return error; 854 } 855 856 void 857 in_delayed_cksum(struct mbuf *m) 858 { 859 struct ip *ip; 860 uint16_t csum, offset, ip_len; 861 862 ip = mtod(m, struct ip *); 863 offset = ip->ip_hl << 2 ; 864 ip_len = ntohs(ip->ip_len); 865 csum = in_cksum_skip(m, ip_len, offset); 866 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0) 867 csum = 0xffff; 868 offset += m->m_pkthdr.csum_data; /* checksum offset */ 869 870 /* find the mbuf in the chain where the checksum starts*/ 871 while ((m != NULL) && (offset >= m->m_len)) { 872 offset -= m->m_len; 873 m = m->m_next; 874 } 875 KASSERT(m != NULL, ("in_delayed_cksum: checksum outside mbuf chain.")); 876 KASSERT(offset + sizeof(u_short) <= m->m_len, ("in_delayed_cksum: checksum split between mbufs.")); 877 *(u_short *)(m->m_data + offset) = csum; 878 } 879 880 /* 881 * IP socket option processing. 882 */ 883 int 884 ip_ctloutput(struct socket *so, struct sockopt *sopt) 885 { 886 struct inpcb *inp = sotoinpcb(so); 887 int error, optval; 888 #ifdef RSS 889 uint32_t rss_bucket; 890 int retval; 891 #endif 892 893 error = optval = 0; 894 if (sopt->sopt_level != IPPROTO_IP) { 895 error = EINVAL; 896 897 if (sopt->sopt_level == SOL_SOCKET && 898 sopt->sopt_dir == SOPT_SET) { 899 switch (sopt->sopt_name) { 900 case SO_REUSEADDR: 901 INP_WLOCK(inp); 902 if ((so->so_options & SO_REUSEADDR) != 0) 903 inp->inp_flags2 |= INP_REUSEADDR; 904 else 905 inp->inp_flags2 &= ~INP_REUSEADDR; 906 INP_WUNLOCK(inp); 907 error = 0; 908 break; 909 case SO_REUSEPORT: 910 INP_WLOCK(inp); 911 if ((so->so_options & SO_REUSEPORT) != 0) 912 inp->inp_flags2 |= INP_REUSEPORT; 913 else 914 inp->inp_flags2 &= ~INP_REUSEPORT; 915 INP_WUNLOCK(inp); 916 error = 0; 917 break; 918 case SO_SETFIB: 919 INP_WLOCK(inp); 920 inp->inp_inc.inc_fibnum = so->so_fibnum; 921 INP_WUNLOCK(inp); 922 error = 0; 923 break; 924 default: 925 break; 926 } 927 } 928 return (error); 929 } 930 931 switch (sopt->sopt_dir) { 932 case SOPT_SET: 933 switch (sopt->sopt_name) { 934 case IP_OPTIONS: 935 #ifdef notyet 936 case IP_RETOPTS: 937 #endif 938 { 939 struct mbuf *m; 940 if (sopt->sopt_valsize > MLEN) { 941 error = EMSGSIZE; 942 break; 943 } 944 m = m_get(sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA); 945 if (m == NULL) { 946 error = ENOBUFS; 947 break; 948 } 949 m->m_len = sopt->sopt_valsize; 950 error = sooptcopyin(sopt, mtod(m, char *), m->m_len, 951 m->m_len); 952 if (error) { 953 m_free(m); 954 break; 955 } 956 INP_WLOCK(inp); 957 error = ip_pcbopts(inp, sopt->sopt_name, m); 958 INP_WUNLOCK(inp); 959 return (error); 960 } 961 962 case IP_BINDANY: 963 if (sopt->sopt_td != NULL) { 964 error = priv_check(sopt->sopt_td, 965 PRIV_NETINET_BINDANY); 966 if (error) 967 break; 968 } 969 /* FALLTHROUGH */ 970 case IP_BINDMULTI: 971 #ifdef RSS 972 case IP_RSS_LISTEN_BUCKET: 973 #endif 974 case IP_TOS: 975 case IP_TTL: 976 case IP_MINTTL: 977 case IP_RECVOPTS: 978 case IP_RECVRETOPTS: 979 case IP_RECVDSTADDR: 980 case IP_RECVTTL: 981 case IP_RECVIF: 982 case IP_ONESBCAST: 983 case IP_DONTFRAG: 984 case IP_RECVTOS: 985 case IP_RECVFLOWID: 986 #ifdef RSS 987 case IP_RECVRSSBUCKETID: 988 #endif 989 error = sooptcopyin(sopt, &optval, sizeof optval, 990 sizeof optval); 991 if (error) 992 break; 993 994 switch (sopt->sopt_name) { 995 case IP_TOS: 996 inp->inp_ip_tos = optval; 997 break; 998 999 case IP_TTL: 1000 inp->inp_ip_ttl = optval; 1001 break; 1002 1003 case IP_MINTTL: 1004 if (optval >= 0 && optval <= MAXTTL) 1005 inp->inp_ip_minttl = optval; 1006 else 1007 error = EINVAL; 1008 break; 1009 1010 #define OPTSET(bit) do { \ 1011 INP_WLOCK(inp); \ 1012 if (optval) \ 1013 inp->inp_flags |= bit; \ 1014 else \ 1015 inp->inp_flags &= ~bit; \ 1016 INP_WUNLOCK(inp); \ 1017 } while (0) 1018 1019 #define OPTSET2(bit, val) do { \ 1020 INP_WLOCK(inp); \ 1021 if (val) \ 1022 inp->inp_flags2 |= bit; \ 1023 else \ 1024 inp->inp_flags2 &= ~bit; \ 1025 INP_WUNLOCK(inp); \ 1026 } while (0) 1027 1028 case IP_RECVOPTS: 1029 OPTSET(INP_RECVOPTS); 1030 break; 1031 1032 case IP_RECVRETOPTS: 1033 OPTSET(INP_RECVRETOPTS); 1034 break; 1035 1036 case IP_RECVDSTADDR: 1037 OPTSET(INP_RECVDSTADDR); 1038 break; 1039 1040 case IP_RECVTTL: 1041 OPTSET(INP_RECVTTL); 1042 break; 1043 1044 case IP_RECVIF: 1045 OPTSET(INP_RECVIF); 1046 break; 1047 1048 case IP_ONESBCAST: 1049 OPTSET(INP_ONESBCAST); 1050 break; 1051 case IP_DONTFRAG: 1052 OPTSET(INP_DONTFRAG); 1053 break; 1054 case IP_BINDANY: 1055 OPTSET(INP_BINDANY); 1056 break; 1057 case IP_RECVTOS: 1058 OPTSET(INP_RECVTOS); 1059 break; 1060 case IP_BINDMULTI: 1061 OPTSET2(INP_BINDMULTI, optval); 1062 break; 1063 case IP_RECVFLOWID: 1064 OPTSET2(INP_RECVFLOWID, optval); 1065 break; 1066 #ifdef RSS 1067 case IP_RSS_LISTEN_BUCKET: 1068 if ((optval >= 0) && 1069 (optval < rss_getnumbuckets())) { 1070 inp->inp_rss_listen_bucket = optval; 1071 OPTSET2(INP_RSS_BUCKET_SET, 1); 1072 } else { 1073 error = EINVAL; 1074 } 1075 break; 1076 case IP_RECVRSSBUCKETID: 1077 OPTSET2(INP_RECVRSSBUCKETID, optval); 1078 break; 1079 #endif 1080 } 1081 break; 1082 #undef OPTSET 1083 #undef OPTSET2 1084 1085 /* 1086 * Multicast socket options are processed by the in_mcast 1087 * module. 1088 */ 1089 case IP_MULTICAST_IF: 1090 case IP_MULTICAST_VIF: 1091 case IP_MULTICAST_TTL: 1092 case IP_MULTICAST_LOOP: 1093 case IP_ADD_MEMBERSHIP: 1094 case IP_DROP_MEMBERSHIP: 1095 case IP_ADD_SOURCE_MEMBERSHIP: 1096 case IP_DROP_SOURCE_MEMBERSHIP: 1097 case IP_BLOCK_SOURCE: 1098 case IP_UNBLOCK_SOURCE: 1099 case IP_MSFILTER: 1100 case MCAST_JOIN_GROUP: 1101 case MCAST_LEAVE_GROUP: 1102 case MCAST_JOIN_SOURCE_GROUP: 1103 case MCAST_LEAVE_SOURCE_GROUP: 1104 case MCAST_BLOCK_SOURCE: 1105 case MCAST_UNBLOCK_SOURCE: 1106 error = inp_setmoptions(inp, sopt); 1107 break; 1108 1109 case IP_PORTRANGE: 1110 error = sooptcopyin(sopt, &optval, sizeof optval, 1111 sizeof optval); 1112 if (error) 1113 break; 1114 1115 INP_WLOCK(inp); 1116 switch (optval) { 1117 case IP_PORTRANGE_DEFAULT: 1118 inp->inp_flags &= ~(INP_LOWPORT); 1119 inp->inp_flags &= ~(INP_HIGHPORT); 1120 break; 1121 1122 case IP_PORTRANGE_HIGH: 1123 inp->inp_flags &= ~(INP_LOWPORT); 1124 inp->inp_flags |= INP_HIGHPORT; 1125 break; 1126 1127 case IP_PORTRANGE_LOW: 1128 inp->inp_flags &= ~(INP_HIGHPORT); 1129 inp->inp_flags |= INP_LOWPORT; 1130 break; 1131 1132 default: 1133 error = EINVAL; 1134 break; 1135 } 1136 INP_WUNLOCK(inp); 1137 break; 1138 1139 #ifdef IPSEC 1140 case IP_IPSEC_POLICY: 1141 { 1142 caddr_t req; 1143 struct mbuf *m; 1144 1145 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */ 1146 break; 1147 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */ 1148 break; 1149 req = mtod(m, caddr_t); 1150 error = ipsec_set_policy(inp, sopt->sopt_name, req, 1151 m->m_len, (sopt->sopt_td != NULL) ? 1152 sopt->sopt_td->td_ucred : NULL); 1153 m_freem(m); 1154 break; 1155 } 1156 #endif /* IPSEC */ 1157 1158 default: 1159 error = ENOPROTOOPT; 1160 break; 1161 } 1162 break; 1163 1164 case SOPT_GET: 1165 switch (sopt->sopt_name) { 1166 case IP_OPTIONS: 1167 case IP_RETOPTS: 1168 if (inp->inp_options) 1169 error = sooptcopyout(sopt, 1170 mtod(inp->inp_options, 1171 char *), 1172 inp->inp_options->m_len); 1173 else 1174 sopt->sopt_valsize = 0; 1175 break; 1176 1177 case IP_TOS: 1178 case IP_TTL: 1179 case IP_MINTTL: 1180 case IP_RECVOPTS: 1181 case IP_RECVRETOPTS: 1182 case IP_RECVDSTADDR: 1183 case IP_RECVTTL: 1184 case IP_RECVIF: 1185 case IP_PORTRANGE: 1186 case IP_ONESBCAST: 1187 case IP_DONTFRAG: 1188 case IP_BINDANY: 1189 case IP_RECVTOS: 1190 case IP_BINDMULTI: 1191 case IP_FLOWID: 1192 case IP_FLOWTYPE: 1193 case IP_RECVFLOWID: 1194 #ifdef RSS 1195 case IP_RSSBUCKETID: 1196 case IP_RECVRSSBUCKETID: 1197 #endif 1198 switch (sopt->sopt_name) { 1199 1200 case IP_TOS: 1201 optval = inp->inp_ip_tos; 1202 break; 1203 1204 case IP_TTL: 1205 optval = inp->inp_ip_ttl; 1206 break; 1207 1208 case IP_MINTTL: 1209 optval = inp->inp_ip_minttl; 1210 break; 1211 1212 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1213 #define OPTBIT2(bit) (inp->inp_flags2 & bit ? 1 : 0) 1214 1215 case IP_RECVOPTS: 1216 optval = OPTBIT(INP_RECVOPTS); 1217 break; 1218 1219 case IP_RECVRETOPTS: 1220 optval = OPTBIT(INP_RECVRETOPTS); 1221 break; 1222 1223 case IP_RECVDSTADDR: 1224 optval = OPTBIT(INP_RECVDSTADDR); 1225 break; 1226 1227 case IP_RECVTTL: 1228 optval = OPTBIT(INP_RECVTTL); 1229 break; 1230 1231 case IP_RECVIF: 1232 optval = OPTBIT(INP_RECVIF); 1233 break; 1234 1235 case IP_PORTRANGE: 1236 if (inp->inp_flags & INP_HIGHPORT) 1237 optval = IP_PORTRANGE_HIGH; 1238 else if (inp->inp_flags & INP_LOWPORT) 1239 optval = IP_PORTRANGE_LOW; 1240 else 1241 optval = 0; 1242 break; 1243 1244 case IP_ONESBCAST: 1245 optval = OPTBIT(INP_ONESBCAST); 1246 break; 1247 case IP_DONTFRAG: 1248 optval = OPTBIT(INP_DONTFRAG); 1249 break; 1250 case IP_BINDANY: 1251 optval = OPTBIT(INP_BINDANY); 1252 break; 1253 case IP_RECVTOS: 1254 optval = OPTBIT(INP_RECVTOS); 1255 break; 1256 case IP_FLOWID: 1257 optval = inp->inp_flowid; 1258 break; 1259 case IP_FLOWTYPE: 1260 optval = inp->inp_flowtype; 1261 break; 1262 case IP_RECVFLOWID: 1263 optval = OPTBIT2(INP_RECVFLOWID); 1264 break; 1265 #ifdef RSS 1266 case IP_RSSBUCKETID: 1267 retval = rss_hash2bucket(inp->inp_flowid, 1268 inp->inp_flowtype, 1269 &rss_bucket); 1270 if (retval == 0) 1271 optval = rss_bucket; 1272 else 1273 error = EINVAL; 1274 break; 1275 case IP_RECVRSSBUCKETID: 1276 optval = OPTBIT2(INP_RECVRSSBUCKETID); 1277 break; 1278 #endif 1279 case IP_BINDMULTI: 1280 optval = OPTBIT2(INP_BINDMULTI); 1281 break; 1282 } 1283 error = sooptcopyout(sopt, &optval, sizeof optval); 1284 break; 1285 1286 /* 1287 * Multicast socket options are processed by the in_mcast 1288 * module. 1289 */ 1290 case IP_MULTICAST_IF: 1291 case IP_MULTICAST_VIF: 1292 case IP_MULTICAST_TTL: 1293 case IP_MULTICAST_LOOP: 1294 case IP_MSFILTER: 1295 error = inp_getmoptions(inp, sopt); 1296 break; 1297 1298 #ifdef IPSEC 1299 case IP_IPSEC_POLICY: 1300 { 1301 struct mbuf *m = NULL; 1302 caddr_t req = NULL; 1303 size_t len = 0; 1304 1305 if (m != 0) { 1306 req = mtod(m, caddr_t); 1307 len = m->m_len; 1308 } 1309 error = ipsec_get_policy(sotoinpcb(so), req, len, &m); 1310 if (error == 0) 1311 error = soopt_mcopyout(sopt, m); /* XXX */ 1312 if (error == 0) 1313 m_freem(m); 1314 break; 1315 } 1316 #endif /* IPSEC */ 1317 1318 default: 1319 error = ENOPROTOOPT; 1320 break; 1321 } 1322 break; 1323 } 1324 return (error); 1325 } 1326 1327 /* 1328 * Routine called from ip_output() to loop back a copy of an IP multicast 1329 * packet to the input queue of a specified interface. Note that this 1330 * calls the output routine of the loopback "driver", but with an interface 1331 * pointer that might NOT be a loopback interface -- evil, but easier than 1332 * replicating that code here. 1333 */ 1334 static void 1335 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst, 1336 int hlen) 1337 { 1338 register struct ip *ip; 1339 struct mbuf *copym; 1340 1341 /* 1342 * Make a deep copy of the packet because we're going to 1343 * modify the pack in order to generate checksums. 1344 */ 1345 copym = m_dup(m, M_NOWAIT); 1346 if (copym != NULL && (!M_WRITABLE(copym) || copym->m_len < hlen)) 1347 copym = m_pullup(copym, hlen); 1348 if (copym != NULL) { 1349 /* If needed, compute the checksum and mark it as valid. */ 1350 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 1351 in_delayed_cksum(copym); 1352 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 1353 copym->m_pkthdr.csum_flags |= 1354 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 1355 copym->m_pkthdr.csum_data = 0xffff; 1356 } 1357 /* 1358 * We don't bother to fragment if the IP length is greater 1359 * than the interface's MTU. Can this possibly matter? 1360 */ 1361 ip = mtod(copym, struct ip *); 1362 ip->ip_sum = 0; 1363 ip->ip_sum = in_cksum(copym, hlen); 1364 #if 1 /* XXX */ 1365 if (dst->sin_family != AF_INET) { 1366 printf("ip_mloopback: bad address family %d\n", 1367 dst->sin_family); 1368 dst->sin_family = AF_INET; 1369 } 1370 #endif 1371 if_simloop(ifp, copym, dst->sin_family, 0); 1372 } 1373 } 1374