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 inp->inp_flags & (INP_HW_FLOWID|INP_SW_FLOWID)) { 152 m->m_pkthdr.flowid = inp->inp_flowid; 153 M_HASHTYPE_SET(m, inp->inp_flowtype); 154 m->m_flags |= M_FLOWID; 155 } 156 } 157 158 if (ro == NULL) { 159 ro = &iproute; 160 bzero(ro, sizeof (*ro)); 161 } 162 163 #ifdef FLOWTABLE 164 if (ro->ro_rt == NULL) 165 (void )flowtable_lookup(AF_INET, m, ro); 166 #endif 167 168 if (opt) { 169 int len = 0; 170 m = ip_insertoptions(m, opt, &len); 171 if (len != 0) 172 hlen = len; /* ip->ip_hl is updated above */ 173 } 174 ip = mtod(m, struct ip *); 175 ip_len = ntohs(ip->ip_len); 176 ip_off = ntohs(ip->ip_off); 177 178 /* 179 * Fill in IP header. If we are not allowing fragmentation, 180 * then the ip_id field is meaningless, but we don't set it 181 * to zero. Doing so causes various problems when devices along 182 * the path (routers, load balancers, firewalls, etc.) illegally 183 * disable DF on our packet. Note that a 16-bit counter 184 * will wrap around in less than 10 seconds at 100 Mbit/s on a 185 * medium with MTU 1500. See Steven M. Bellovin, "A Technique 186 * for Counting NATted Hosts", Proc. IMW'02, available at 187 * <http://www.cs.columbia.edu/~smb/papers/fnat.pdf>. 188 */ 189 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 190 ip->ip_v = IPVERSION; 191 ip->ip_hl = hlen >> 2; 192 ip->ip_id = ip_newid(); 193 IPSTAT_INC(ips_localout); 194 } else { 195 /* Header already set, fetch hlen from there */ 196 hlen = ip->ip_hl << 2; 197 } 198 199 /* 200 * dst/gw handling: 201 * 202 * dst can be rewritten but always points to &ro->ro_dst. 203 * gw is readonly but can point either to dst OR rt_gateway, 204 * therefore we need restore gw if we're redoing lookup. 205 */ 206 gw = dst = (struct sockaddr_in *)&ro->ro_dst; 207 fibnum = (inp != NULL) ? inp->inp_inc.inc_fibnum : M_GETFIB(m); 208 again: 209 ia = NULL; 210 have_ia_ref = 0; 211 /* 212 * If there is a cached route, check that it is to the same 213 * destination and is still up. If not, free it and try again. 214 * The address family should also be checked in case of sharing 215 * the cache with IPv6. 216 */ 217 rte = ro->ro_rt; 218 if (rte && ((rte->rt_flags & RTF_UP) == 0 || 219 rte->rt_ifp == NULL || 220 !RT_LINK_IS_UP(rte->rt_ifp) || 221 dst->sin_family != AF_INET || 222 dst->sin_addr.s_addr != ip->ip_dst.s_addr)) { 223 RO_RTFREE(ro); 224 ro->ro_lle = NULL; 225 rte = NULL; 226 gw = dst; 227 } 228 if (rte == NULL && fwd_tag == NULL) { 229 bzero(dst, sizeof(*dst)); 230 dst->sin_family = AF_INET; 231 dst->sin_len = sizeof(*dst); 232 dst->sin_addr = ip->ip_dst; 233 } 234 /* 235 * If routing to interface only, short circuit routing lookup. 236 * The use of an all-ones broadcast address implies this; an 237 * interface is specified by the broadcast address of an interface, 238 * or the destination address of a ptp interface. 239 */ 240 if (flags & IP_SENDONES) { 241 if ((ia = ifatoia(ifa_ifwithbroadaddr(sintosa(dst), 242 M_GETFIB(m)))) == NULL && 243 (ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst), 244 M_GETFIB(m)))) == NULL) { 245 IPSTAT_INC(ips_noroute); 246 error = ENETUNREACH; 247 goto bad; 248 } 249 have_ia_ref = 1; 250 ip->ip_dst.s_addr = INADDR_BROADCAST; 251 dst->sin_addr = ip->ip_dst; 252 ifp = ia->ia_ifp; 253 ip->ip_ttl = 1; 254 isbroadcast = 1; 255 } else if (flags & IP_ROUTETOIF) { 256 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst), 257 M_GETFIB(m)))) == NULL && 258 (ia = ifatoia(ifa_ifwithnet(sintosa(dst), 0, 259 M_GETFIB(m)))) == NULL) { 260 IPSTAT_INC(ips_noroute); 261 error = ENETUNREACH; 262 goto bad; 263 } 264 have_ia_ref = 1; 265 ifp = ia->ia_ifp; 266 ip->ip_ttl = 1; 267 isbroadcast = in_broadcast(dst->sin_addr, ifp); 268 } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) && 269 imo != NULL && imo->imo_multicast_ifp != NULL) { 270 /* 271 * Bypass the normal routing lookup for multicast 272 * packets if the interface is specified. 273 */ 274 ifp = imo->imo_multicast_ifp; 275 IFP_TO_IA(ifp, ia); 276 if (ia) 277 have_ia_ref = 1; 278 isbroadcast = 0; /* fool gcc */ 279 } else { 280 /* 281 * We want to do any cloning requested by the link layer, 282 * as this is probably required in all cases for correct 283 * operation (as it is for ARP). 284 */ 285 if (rte == NULL) { 286 #ifdef RADIX_MPATH 287 rtalloc_mpath_fib(ro, 288 ntohl(ip->ip_src.s_addr ^ ip->ip_dst.s_addr), 289 fibnum); 290 #else 291 in_rtalloc_ign(ro, 0, fibnum); 292 #endif 293 rte = ro->ro_rt; 294 } 295 if (rte == NULL || 296 rte->rt_ifp == NULL || 297 !RT_LINK_IS_UP(rte->rt_ifp)) { 298 #ifdef IPSEC 299 /* 300 * There is no route for this packet, but it is 301 * possible that a matching SPD entry exists. 302 */ 303 no_route_but_check_spd = 1; 304 mtu = 0; /* Silence GCC warning. */ 305 goto sendit; 306 #endif 307 IPSTAT_INC(ips_noroute); 308 error = EHOSTUNREACH; 309 goto bad; 310 } 311 ia = ifatoia(rte->rt_ifa); 312 ifp = rte->rt_ifp; 313 counter_u64_add(rte->rt_pksent, 1); 314 if (rte->rt_flags & RTF_GATEWAY) 315 gw = (struct sockaddr_in *)rte->rt_gateway; 316 if (rte->rt_flags & RTF_HOST) 317 isbroadcast = (rte->rt_flags & RTF_BROADCAST); 318 else 319 isbroadcast = in_broadcast(gw->sin_addr, ifp); 320 } 321 /* 322 * Calculate MTU. If we have a route that is up, use that, 323 * otherwise use the interface's MTU. 324 */ 325 if (rte != NULL && (rte->rt_flags & (RTF_UP|RTF_HOST))) 326 mtu = rte->rt_mtu; 327 else 328 mtu = ifp->if_mtu; 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 * Look for broadcast address and 442 * verify user is allowed to send 443 * such a packet. 444 */ 445 if (isbroadcast) { 446 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 447 error = EADDRNOTAVAIL; 448 goto bad; 449 } 450 if ((flags & IP_ALLOWBROADCAST) == 0) { 451 error = EACCES; 452 goto bad; 453 } 454 /* don't allow broadcast messages to be fragmented */ 455 if (ip_len > mtu) { 456 error = EMSGSIZE; 457 goto bad; 458 } 459 m->m_flags |= M_BCAST; 460 } else { 461 m->m_flags &= ~M_BCAST; 462 } 463 464 sendit: 465 #ifdef IPSEC 466 switch(ip_ipsec_output(&m, inp, &flags, &error)) { 467 case 1: 468 goto bad; 469 case -1: 470 goto done; 471 case 0: 472 default: 473 break; /* Continue with packet processing. */ 474 } 475 /* 476 * Check if there was a route for this packet; return error if not. 477 */ 478 if (no_route_but_check_spd) { 479 IPSTAT_INC(ips_noroute); 480 error = EHOSTUNREACH; 481 goto bad; 482 } 483 /* Update variables that are affected by ipsec4_output(). */ 484 ip = mtod(m, struct ip *); 485 hlen = ip->ip_hl << 2; 486 #endif /* IPSEC */ 487 488 /* Jump over all PFIL processing if hooks are not active. */ 489 if (!PFIL_HOOKED(&V_inet_pfil_hook)) 490 goto passout; 491 492 /* Run through list of hooks for output packets. */ 493 odst.s_addr = ip->ip_dst.s_addr; 494 error = pfil_run_hooks(&V_inet_pfil_hook, &m, ifp, PFIL_OUT, inp); 495 if (error != 0 || m == NULL) 496 goto done; 497 498 ip = mtod(m, struct ip *); 499 needfiblookup = 0; 500 501 /* See if destination IP address was changed by packet filter. */ 502 if (odst.s_addr != ip->ip_dst.s_addr) { 503 m->m_flags |= M_SKIP_FIREWALL; 504 /* If destination is now ourself drop to ip_input(). */ 505 if (in_localip(ip->ip_dst)) { 506 m->m_flags |= M_FASTFWD_OURS; 507 if (m->m_pkthdr.rcvif == NULL) 508 m->m_pkthdr.rcvif = V_loif; 509 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 510 m->m_pkthdr.csum_flags |= 511 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 512 m->m_pkthdr.csum_data = 0xffff; 513 } 514 m->m_pkthdr.csum_flags |= 515 CSUM_IP_CHECKED | CSUM_IP_VALID; 516 #ifdef SCTP 517 if (m->m_pkthdr.csum_flags & CSUM_SCTP) 518 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID; 519 #endif 520 error = netisr_queue(NETISR_IP, m); 521 goto done; 522 } else { 523 if (have_ia_ref) 524 ifa_free(&ia->ia_ifa); 525 needfiblookup = 1; /* Redo the routing table lookup. */ 526 } 527 } 528 /* See if fib was changed by packet filter. */ 529 if (fibnum != M_GETFIB(m)) { 530 m->m_flags |= M_SKIP_FIREWALL; 531 fibnum = M_GETFIB(m); 532 RO_RTFREE(ro); 533 needfiblookup = 1; 534 } 535 if (needfiblookup) 536 goto again; 537 538 /* See if local, if yes, send it to netisr with IP_FASTFWD_OURS. */ 539 if (m->m_flags & M_FASTFWD_OURS) { 540 if (m->m_pkthdr.rcvif == NULL) 541 m->m_pkthdr.rcvif = V_loif; 542 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 543 m->m_pkthdr.csum_flags |= 544 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 545 m->m_pkthdr.csum_data = 0xffff; 546 } 547 #ifdef SCTP 548 if (m->m_pkthdr.csum_flags & CSUM_SCTP) 549 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID; 550 #endif 551 m->m_pkthdr.csum_flags |= 552 CSUM_IP_CHECKED | CSUM_IP_VALID; 553 554 error = netisr_queue(NETISR_IP, m); 555 goto done; 556 } 557 /* Or forward to some other address? */ 558 if ((m->m_flags & M_IP_NEXTHOP) && 559 (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) { 560 bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in)); 561 m->m_flags |= M_SKIP_FIREWALL; 562 m->m_flags &= ~M_IP_NEXTHOP; 563 m_tag_delete(m, fwd_tag); 564 if (have_ia_ref) 565 ifa_free(&ia->ia_ifa); 566 goto again; 567 } 568 569 passout: 570 /* 127/8 must not appear on wire - RFC1122. */ 571 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET || 572 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) { 573 if ((ifp->if_flags & IFF_LOOPBACK) == 0) { 574 IPSTAT_INC(ips_badaddr); 575 error = EADDRNOTAVAIL; 576 goto bad; 577 } 578 } 579 580 m->m_pkthdr.csum_flags |= CSUM_IP; 581 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA & ~ifp->if_hwassist) { 582 in_delayed_cksum(m); 583 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 584 } 585 #ifdef SCTP 586 if (m->m_pkthdr.csum_flags & CSUM_SCTP & ~ifp->if_hwassist) { 587 sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2)); 588 m->m_pkthdr.csum_flags &= ~CSUM_SCTP; 589 } 590 #endif 591 592 /* 593 * If small enough for interface, or the interface will take 594 * care of the fragmentation for us, we can just send directly. 595 */ 596 if (ip_len <= mtu || 597 (m->m_pkthdr.csum_flags & ifp->if_hwassist & CSUM_TSO) != 0) { 598 ip->ip_sum = 0; 599 if (m->m_pkthdr.csum_flags & CSUM_IP & ~ifp->if_hwassist) { 600 ip->ip_sum = in_cksum(m, hlen); 601 m->m_pkthdr.csum_flags &= ~CSUM_IP; 602 } 603 604 /* 605 * Record statistics for this interface address. 606 * With CSUM_TSO the byte/packet count will be slightly 607 * incorrect because we count the IP+TCP headers only 608 * once instead of for every generated packet. 609 */ 610 if (!(flags & IP_FORWARDING) && ia) { 611 if (m->m_pkthdr.csum_flags & CSUM_TSO) 612 counter_u64_add(ia->ia_ifa.ifa_opackets, 613 m->m_pkthdr.len / m->m_pkthdr.tso_segsz); 614 else 615 counter_u64_add(ia->ia_ifa.ifa_opackets, 1); 616 617 counter_u64_add(ia->ia_ifa.ifa_obytes, m->m_pkthdr.len); 618 } 619 #ifdef MBUF_STRESS_TEST 620 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size) 621 m = m_fragment(m, M_NOWAIT, mbuf_frag_size); 622 #endif 623 /* 624 * Reset layer specific mbuf flags 625 * to avoid confusing lower layers. 626 */ 627 m_clrprotoflags(m); 628 IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL); 629 error = (*ifp->if_output)(ifp, m, 630 (const struct sockaddr *)gw, ro); 631 goto done; 632 } 633 634 /* Balk when DF bit is set or the interface didn't support TSO. */ 635 if ((ip_off & IP_DF) || (m->m_pkthdr.csum_flags & CSUM_TSO)) { 636 error = EMSGSIZE; 637 IPSTAT_INC(ips_cantfrag); 638 goto bad; 639 } 640 641 /* 642 * Too large for interface; fragment if possible. If successful, 643 * on return, m will point to a list of packets to be sent. 644 */ 645 error = ip_fragment(ip, &m, mtu, ifp->if_hwassist); 646 if (error) 647 goto bad; 648 for (; m; m = m0) { 649 m0 = m->m_nextpkt; 650 m->m_nextpkt = 0; 651 if (error == 0) { 652 /* Record statistics for this interface address. */ 653 if (ia != NULL) { 654 counter_u64_add(ia->ia_ifa.ifa_opackets, 1); 655 counter_u64_add(ia->ia_ifa.ifa_obytes, 656 m->m_pkthdr.len); 657 } 658 /* 659 * Reset layer specific mbuf flags 660 * to avoid confusing upper layers. 661 */ 662 m_clrprotoflags(m); 663 664 IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL); 665 error = (*ifp->if_output)(ifp, m, 666 (const struct sockaddr *)gw, ro); 667 } else 668 m_freem(m); 669 } 670 671 if (error == 0) 672 IPSTAT_INC(ips_fragmented); 673 674 done: 675 if (ro == &iproute) 676 RO_RTFREE(ro); 677 if (have_ia_ref) 678 ifa_free(&ia->ia_ifa); 679 return (error); 680 bad: 681 m_freem(m); 682 goto done; 683 } 684 685 /* 686 * Create a chain of fragments which fit the given mtu. m_frag points to the 687 * mbuf to be fragmented; on return it points to the chain with the fragments. 688 * Return 0 if no error. If error, m_frag may contain a partially built 689 * chain of fragments that should be freed by the caller. 690 * 691 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist) 692 */ 693 int 694 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu, 695 u_long if_hwassist_flags) 696 { 697 int error = 0; 698 int hlen = ip->ip_hl << 2; 699 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */ 700 int off; 701 struct mbuf *m0 = *m_frag; /* the original packet */ 702 int firstlen; 703 struct mbuf **mnext; 704 int nfrags; 705 uint16_t ip_len, ip_off; 706 707 ip_len = ntohs(ip->ip_len); 708 ip_off = ntohs(ip->ip_off); 709 710 if (ip_off & IP_DF) { /* Fragmentation not allowed */ 711 IPSTAT_INC(ips_cantfrag); 712 return EMSGSIZE; 713 } 714 715 /* 716 * Must be able to put at least 8 bytes per fragment. 717 */ 718 if (len < 8) 719 return EMSGSIZE; 720 721 /* 722 * If the interface will not calculate checksums on 723 * fragmented packets, then do it here. 724 */ 725 if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 726 in_delayed_cksum(m0); 727 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 728 } 729 #ifdef SCTP 730 if (m0->m_pkthdr.csum_flags & CSUM_SCTP) { 731 sctp_delayed_cksum(m0, hlen); 732 m0->m_pkthdr.csum_flags &= ~CSUM_SCTP; 733 } 734 #endif 735 if (len > PAGE_SIZE) { 736 /* 737 * Fragment large datagrams such that each segment 738 * contains a multiple of PAGE_SIZE amount of data, 739 * plus headers. This enables a receiver to perform 740 * page-flipping zero-copy optimizations. 741 * 742 * XXX When does this help given that sender and receiver 743 * could have different page sizes, and also mtu could 744 * be less than the receiver's page size ? 745 */ 746 int newlen; 747 struct mbuf *m; 748 749 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next) 750 off += m->m_len; 751 752 /* 753 * firstlen (off - hlen) must be aligned on an 754 * 8-byte boundary 755 */ 756 if (off < hlen) 757 goto smart_frag_failure; 758 off = ((off - hlen) & ~7) + hlen; 759 newlen = (~PAGE_MASK) & mtu; 760 if ((newlen + sizeof (struct ip)) > mtu) { 761 /* we failed, go back the default */ 762 smart_frag_failure: 763 newlen = len; 764 off = hlen + len; 765 } 766 len = newlen; 767 768 } else { 769 off = hlen + len; 770 } 771 772 firstlen = off - hlen; 773 mnext = &m0->m_nextpkt; /* pointer to next packet */ 774 775 /* 776 * Loop through length of segment after first fragment, 777 * make new header and copy data of each part and link onto chain. 778 * Here, m0 is the original packet, m is the fragment being created. 779 * The fragments are linked off the m_nextpkt of the original 780 * packet, which after processing serves as the first fragment. 781 */ 782 for (nfrags = 1; off < ip_len; off += len, nfrags++) { 783 struct ip *mhip; /* ip header on the fragment */ 784 struct mbuf *m; 785 int mhlen = sizeof (struct ip); 786 787 m = m_gethdr(M_NOWAIT, MT_DATA); 788 if (m == NULL) { 789 error = ENOBUFS; 790 IPSTAT_INC(ips_odropped); 791 goto done; 792 } 793 m->m_flags |= (m0->m_flags & M_MCAST); 794 /* 795 * In the first mbuf, leave room for the link header, then 796 * copy the original IP header including options. The payload 797 * goes into an additional mbuf chain returned by m_copym(). 798 */ 799 m->m_data += max_linkhdr; 800 mhip = mtod(m, struct ip *); 801 *mhip = *ip; 802 if (hlen > sizeof (struct ip)) { 803 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 804 mhip->ip_v = IPVERSION; 805 mhip->ip_hl = mhlen >> 2; 806 } 807 m->m_len = mhlen; 808 /* XXX do we need to add ip_off below ? */ 809 mhip->ip_off = ((off - hlen) >> 3) + ip_off; 810 if (off + len >= ip_len) 811 len = ip_len - off; 812 else 813 mhip->ip_off |= IP_MF; 814 mhip->ip_len = htons((u_short)(len + mhlen)); 815 m->m_next = m_copym(m0, off, len, M_NOWAIT); 816 if (m->m_next == NULL) { /* copy failed */ 817 m_free(m); 818 error = ENOBUFS; /* ??? */ 819 IPSTAT_INC(ips_odropped); 820 goto done; 821 } 822 m->m_pkthdr.len = mhlen + len; 823 m->m_pkthdr.rcvif = NULL; 824 #ifdef MAC 825 mac_netinet_fragment(m0, m); 826 #endif 827 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags; 828 mhip->ip_off = htons(mhip->ip_off); 829 mhip->ip_sum = 0; 830 if (m->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) { 831 mhip->ip_sum = in_cksum(m, mhlen); 832 m->m_pkthdr.csum_flags &= ~CSUM_IP; 833 } 834 *mnext = m; 835 mnext = &m->m_nextpkt; 836 } 837 IPSTAT_ADD(ips_ofragments, nfrags); 838 839 /* 840 * Update first fragment by trimming what's been copied out 841 * and updating header. 842 */ 843 m_adj(m0, hlen + firstlen - ip_len); 844 m0->m_pkthdr.len = hlen + firstlen; 845 ip->ip_len = htons((u_short)m0->m_pkthdr.len); 846 ip->ip_off = htons(ip_off | IP_MF); 847 ip->ip_sum = 0; 848 if (m0->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) { 849 ip->ip_sum = in_cksum(m0, hlen); 850 m0->m_pkthdr.csum_flags &= ~CSUM_IP; 851 } 852 853 done: 854 *m_frag = m0; 855 return error; 856 } 857 858 void 859 in_delayed_cksum(struct mbuf *m) 860 { 861 struct ip *ip; 862 uint16_t csum, offset, ip_len; 863 864 ip = mtod(m, struct ip *); 865 offset = ip->ip_hl << 2 ; 866 ip_len = ntohs(ip->ip_len); 867 csum = in_cksum_skip(m, ip_len, offset); 868 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0) 869 csum = 0xffff; 870 offset += m->m_pkthdr.csum_data; /* checksum offset */ 871 872 /* find the mbuf in the chain where the checksum starts*/ 873 while ((m != NULL) && (offset >= m->m_len)) { 874 offset -= m->m_len; 875 m = m->m_next; 876 } 877 KASSERT(m != NULL, ("in_delayed_cksum: checksum outside mbuf chain.")); 878 KASSERT(offset + sizeof(u_short) <= m->m_len, ("in_delayed_cksum: checksum split between mbufs.")); 879 *(u_short *)(m->m_data + offset) = csum; 880 } 881 882 /* 883 * IP socket option processing. 884 */ 885 int 886 ip_ctloutput(struct socket *so, struct sockopt *sopt) 887 { 888 struct inpcb *inp = sotoinpcb(so); 889 int error, optval; 890 #ifdef RSS 891 uint32_t rss_bucket; 892 int retval; 893 #endif 894 895 error = optval = 0; 896 if (sopt->sopt_level != IPPROTO_IP) { 897 error = EINVAL; 898 899 if (sopt->sopt_level == SOL_SOCKET && 900 sopt->sopt_dir == SOPT_SET) { 901 switch (sopt->sopt_name) { 902 case SO_REUSEADDR: 903 INP_WLOCK(inp); 904 if ((so->so_options & SO_REUSEADDR) != 0) 905 inp->inp_flags2 |= INP_REUSEADDR; 906 else 907 inp->inp_flags2 &= ~INP_REUSEADDR; 908 INP_WUNLOCK(inp); 909 error = 0; 910 break; 911 case SO_REUSEPORT: 912 INP_WLOCK(inp); 913 if ((so->so_options & SO_REUSEPORT) != 0) 914 inp->inp_flags2 |= INP_REUSEPORT; 915 else 916 inp->inp_flags2 &= ~INP_REUSEPORT; 917 INP_WUNLOCK(inp); 918 error = 0; 919 break; 920 case SO_SETFIB: 921 INP_WLOCK(inp); 922 inp->inp_inc.inc_fibnum = so->so_fibnum; 923 INP_WUNLOCK(inp); 924 error = 0; 925 break; 926 default: 927 break; 928 } 929 } 930 return (error); 931 } 932 933 switch (sopt->sopt_dir) { 934 case SOPT_SET: 935 switch (sopt->sopt_name) { 936 case IP_OPTIONS: 937 #ifdef notyet 938 case IP_RETOPTS: 939 #endif 940 { 941 struct mbuf *m; 942 if (sopt->sopt_valsize > MLEN) { 943 error = EMSGSIZE; 944 break; 945 } 946 m = m_get(sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA); 947 if (m == NULL) { 948 error = ENOBUFS; 949 break; 950 } 951 m->m_len = sopt->sopt_valsize; 952 error = sooptcopyin(sopt, mtod(m, char *), m->m_len, 953 m->m_len); 954 if (error) { 955 m_free(m); 956 break; 957 } 958 INP_WLOCK(inp); 959 error = ip_pcbopts(inp, sopt->sopt_name, m); 960 INP_WUNLOCK(inp); 961 return (error); 962 } 963 964 case IP_BINDANY: 965 if (sopt->sopt_td != NULL) { 966 error = priv_check(sopt->sopt_td, 967 PRIV_NETINET_BINDANY); 968 if (error) 969 break; 970 } 971 /* FALLTHROUGH */ 972 case IP_BINDMULTI: 973 #ifdef RSS 974 case IP_RSS_LISTEN_BUCKET: 975 #endif 976 case IP_TOS: 977 case IP_TTL: 978 case IP_MINTTL: 979 case IP_RECVOPTS: 980 case IP_RECVRETOPTS: 981 case IP_RECVDSTADDR: 982 case IP_RECVTTL: 983 case IP_RECVIF: 984 case IP_ONESBCAST: 985 case IP_DONTFRAG: 986 case IP_RECVTOS: 987 case IP_RECVFLOWID: 988 #ifdef RSS 989 case IP_RECVRSSBUCKETID: 990 #endif 991 error = sooptcopyin(sopt, &optval, sizeof optval, 992 sizeof optval); 993 if (error) 994 break; 995 996 switch (sopt->sopt_name) { 997 case IP_TOS: 998 inp->inp_ip_tos = optval; 999 break; 1000 1001 case IP_TTL: 1002 inp->inp_ip_ttl = optval; 1003 break; 1004 1005 case IP_MINTTL: 1006 if (optval >= 0 && optval <= MAXTTL) 1007 inp->inp_ip_minttl = optval; 1008 else 1009 error = EINVAL; 1010 break; 1011 1012 #define OPTSET(bit) do { \ 1013 INP_WLOCK(inp); \ 1014 if (optval) \ 1015 inp->inp_flags |= bit; \ 1016 else \ 1017 inp->inp_flags &= ~bit; \ 1018 INP_WUNLOCK(inp); \ 1019 } while (0) 1020 1021 #define OPTSET2(bit, val) do { \ 1022 INP_WLOCK(inp); \ 1023 if (val) \ 1024 inp->inp_flags2 |= bit; \ 1025 else \ 1026 inp->inp_flags2 &= ~bit; \ 1027 INP_WUNLOCK(inp); \ 1028 } while (0) 1029 1030 case IP_RECVOPTS: 1031 OPTSET(INP_RECVOPTS); 1032 break; 1033 1034 case IP_RECVRETOPTS: 1035 OPTSET(INP_RECVRETOPTS); 1036 break; 1037 1038 case IP_RECVDSTADDR: 1039 OPTSET(INP_RECVDSTADDR); 1040 break; 1041 1042 case IP_RECVTTL: 1043 OPTSET(INP_RECVTTL); 1044 break; 1045 1046 case IP_RECVIF: 1047 OPTSET(INP_RECVIF); 1048 break; 1049 1050 case IP_ONESBCAST: 1051 OPTSET(INP_ONESBCAST); 1052 break; 1053 case IP_DONTFRAG: 1054 OPTSET(INP_DONTFRAG); 1055 break; 1056 case IP_BINDANY: 1057 OPTSET(INP_BINDANY); 1058 break; 1059 case IP_RECVTOS: 1060 OPTSET(INP_RECVTOS); 1061 break; 1062 case IP_BINDMULTI: 1063 OPTSET2(INP_BINDMULTI, optval); 1064 break; 1065 case IP_RECVFLOWID: 1066 OPTSET2(INP_RECVFLOWID, optval); 1067 break; 1068 #ifdef RSS 1069 case IP_RSS_LISTEN_BUCKET: 1070 if ((optval >= 0) && 1071 (optval < rss_getnumbuckets())) { 1072 inp->inp_rss_listen_bucket = optval; 1073 OPTSET2(INP_RSS_BUCKET_SET, 1); 1074 } else { 1075 error = EINVAL; 1076 } 1077 break; 1078 case IP_RECVRSSBUCKETID: 1079 OPTSET2(INP_RECVRSSBUCKETID, optval); 1080 break; 1081 #endif 1082 } 1083 break; 1084 #undef OPTSET 1085 #undef OPTSET2 1086 1087 /* 1088 * Multicast socket options are processed by the in_mcast 1089 * module. 1090 */ 1091 case IP_MULTICAST_IF: 1092 case IP_MULTICAST_VIF: 1093 case IP_MULTICAST_TTL: 1094 case IP_MULTICAST_LOOP: 1095 case IP_ADD_MEMBERSHIP: 1096 case IP_DROP_MEMBERSHIP: 1097 case IP_ADD_SOURCE_MEMBERSHIP: 1098 case IP_DROP_SOURCE_MEMBERSHIP: 1099 case IP_BLOCK_SOURCE: 1100 case IP_UNBLOCK_SOURCE: 1101 case IP_MSFILTER: 1102 case MCAST_JOIN_GROUP: 1103 case MCAST_LEAVE_GROUP: 1104 case MCAST_JOIN_SOURCE_GROUP: 1105 case MCAST_LEAVE_SOURCE_GROUP: 1106 case MCAST_BLOCK_SOURCE: 1107 case MCAST_UNBLOCK_SOURCE: 1108 error = inp_setmoptions(inp, sopt); 1109 break; 1110 1111 case IP_PORTRANGE: 1112 error = sooptcopyin(sopt, &optval, sizeof optval, 1113 sizeof optval); 1114 if (error) 1115 break; 1116 1117 INP_WLOCK(inp); 1118 switch (optval) { 1119 case IP_PORTRANGE_DEFAULT: 1120 inp->inp_flags &= ~(INP_LOWPORT); 1121 inp->inp_flags &= ~(INP_HIGHPORT); 1122 break; 1123 1124 case IP_PORTRANGE_HIGH: 1125 inp->inp_flags &= ~(INP_LOWPORT); 1126 inp->inp_flags |= INP_HIGHPORT; 1127 break; 1128 1129 case IP_PORTRANGE_LOW: 1130 inp->inp_flags &= ~(INP_HIGHPORT); 1131 inp->inp_flags |= INP_LOWPORT; 1132 break; 1133 1134 default: 1135 error = EINVAL; 1136 break; 1137 } 1138 INP_WUNLOCK(inp); 1139 break; 1140 1141 #ifdef IPSEC 1142 case IP_IPSEC_POLICY: 1143 { 1144 caddr_t req; 1145 struct mbuf *m; 1146 1147 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */ 1148 break; 1149 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */ 1150 break; 1151 req = mtod(m, caddr_t); 1152 error = ipsec_set_policy(inp, sopt->sopt_name, req, 1153 m->m_len, (sopt->sopt_td != NULL) ? 1154 sopt->sopt_td->td_ucred : NULL); 1155 m_freem(m); 1156 break; 1157 } 1158 #endif /* IPSEC */ 1159 1160 default: 1161 error = ENOPROTOOPT; 1162 break; 1163 } 1164 break; 1165 1166 case SOPT_GET: 1167 switch (sopt->sopt_name) { 1168 case IP_OPTIONS: 1169 case IP_RETOPTS: 1170 if (inp->inp_options) 1171 error = sooptcopyout(sopt, 1172 mtod(inp->inp_options, 1173 char *), 1174 inp->inp_options->m_len); 1175 else 1176 sopt->sopt_valsize = 0; 1177 break; 1178 1179 case IP_TOS: 1180 case IP_TTL: 1181 case IP_MINTTL: 1182 case IP_RECVOPTS: 1183 case IP_RECVRETOPTS: 1184 case IP_RECVDSTADDR: 1185 case IP_RECVTTL: 1186 case IP_RECVIF: 1187 case IP_PORTRANGE: 1188 case IP_ONESBCAST: 1189 case IP_DONTFRAG: 1190 case IP_BINDANY: 1191 case IP_RECVTOS: 1192 case IP_BINDMULTI: 1193 case IP_FLOWID: 1194 case IP_FLOWTYPE: 1195 case IP_RECVFLOWID: 1196 #ifdef RSS 1197 case IP_RSSBUCKETID: 1198 case IP_RECVRSSBUCKETID: 1199 #endif 1200 switch (sopt->sopt_name) { 1201 1202 case IP_TOS: 1203 optval = inp->inp_ip_tos; 1204 break; 1205 1206 case IP_TTL: 1207 optval = inp->inp_ip_ttl; 1208 break; 1209 1210 case IP_MINTTL: 1211 optval = inp->inp_ip_minttl; 1212 break; 1213 1214 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 1215 #define OPTBIT2(bit) (inp->inp_flags2 & bit ? 1 : 0) 1216 1217 case IP_RECVOPTS: 1218 optval = OPTBIT(INP_RECVOPTS); 1219 break; 1220 1221 case IP_RECVRETOPTS: 1222 optval = OPTBIT(INP_RECVRETOPTS); 1223 break; 1224 1225 case IP_RECVDSTADDR: 1226 optval = OPTBIT(INP_RECVDSTADDR); 1227 break; 1228 1229 case IP_RECVTTL: 1230 optval = OPTBIT(INP_RECVTTL); 1231 break; 1232 1233 case IP_RECVIF: 1234 optval = OPTBIT(INP_RECVIF); 1235 break; 1236 1237 case IP_PORTRANGE: 1238 if (inp->inp_flags & INP_HIGHPORT) 1239 optval = IP_PORTRANGE_HIGH; 1240 else if (inp->inp_flags & INP_LOWPORT) 1241 optval = IP_PORTRANGE_LOW; 1242 else 1243 optval = 0; 1244 break; 1245 1246 case IP_ONESBCAST: 1247 optval = OPTBIT(INP_ONESBCAST); 1248 break; 1249 case IP_DONTFRAG: 1250 optval = OPTBIT(INP_DONTFRAG); 1251 break; 1252 case IP_BINDANY: 1253 optval = OPTBIT(INP_BINDANY); 1254 break; 1255 case IP_RECVTOS: 1256 optval = OPTBIT(INP_RECVTOS); 1257 break; 1258 case IP_FLOWID: 1259 optval = inp->inp_flowid; 1260 break; 1261 case IP_FLOWTYPE: 1262 optval = inp->inp_flowtype; 1263 break; 1264 case IP_RECVFLOWID: 1265 optval = OPTBIT2(INP_RECVFLOWID); 1266 break; 1267 #ifdef RSS 1268 case IP_RSSBUCKETID: 1269 retval = rss_hash2bucket(inp->inp_flowid, 1270 inp->inp_flowtype, 1271 &rss_bucket); 1272 if (retval == 0) 1273 optval = rss_bucket; 1274 else 1275 error = EINVAL; 1276 break; 1277 case IP_RECVRSSBUCKETID: 1278 optval = OPTBIT2(INP_RECVRSSBUCKETID); 1279 break; 1280 #endif 1281 case IP_BINDMULTI: 1282 optval = OPTBIT2(INP_BINDMULTI); 1283 break; 1284 } 1285 error = sooptcopyout(sopt, &optval, sizeof optval); 1286 break; 1287 1288 /* 1289 * Multicast socket options are processed by the in_mcast 1290 * module. 1291 */ 1292 case IP_MULTICAST_IF: 1293 case IP_MULTICAST_VIF: 1294 case IP_MULTICAST_TTL: 1295 case IP_MULTICAST_LOOP: 1296 case IP_MSFILTER: 1297 error = inp_getmoptions(inp, sopt); 1298 break; 1299 1300 #ifdef IPSEC 1301 case IP_IPSEC_POLICY: 1302 { 1303 struct mbuf *m = NULL; 1304 caddr_t req = NULL; 1305 size_t len = 0; 1306 1307 if (m != 0) { 1308 req = mtod(m, caddr_t); 1309 len = m->m_len; 1310 } 1311 error = ipsec_get_policy(sotoinpcb(so), req, len, &m); 1312 if (error == 0) 1313 error = soopt_mcopyout(sopt, m); /* XXX */ 1314 if (error == 0) 1315 m_freem(m); 1316 break; 1317 } 1318 #endif /* IPSEC */ 1319 1320 default: 1321 error = ENOPROTOOPT; 1322 break; 1323 } 1324 break; 1325 } 1326 return (error); 1327 } 1328 1329 /* 1330 * Routine called from ip_output() to loop back a copy of an IP multicast 1331 * packet to the input queue of a specified interface. Note that this 1332 * calls the output routine of the loopback "driver", but with an interface 1333 * pointer that might NOT be a loopback interface -- evil, but easier than 1334 * replicating that code here. 1335 */ 1336 static void 1337 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst, 1338 int hlen) 1339 { 1340 register struct ip *ip; 1341 struct mbuf *copym; 1342 1343 /* 1344 * Make a deep copy of the packet because we're going to 1345 * modify the pack in order to generate checksums. 1346 */ 1347 copym = m_dup(m, M_NOWAIT); 1348 if (copym != NULL && (!M_WRITABLE(copym) || copym->m_len < hlen)) 1349 copym = m_pullup(copym, hlen); 1350 if (copym != NULL) { 1351 /* If needed, compute the checksum and mark it as valid. */ 1352 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { 1353 in_delayed_cksum(copym); 1354 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; 1355 copym->m_pkthdr.csum_flags |= 1356 CSUM_DATA_VALID | CSUM_PSEUDO_HDR; 1357 copym->m_pkthdr.csum_data = 0xffff; 1358 } 1359 /* 1360 * We don't bother to fragment if the IP length is greater 1361 * than the interface's MTU. Can this possibly matter? 1362 */ 1363 ip = mtod(copym, struct ip *); 1364 ip->ip_sum = 0; 1365 ip->ip_sum = in_cksum(copym, hlen); 1366 #if 1 /* XXX */ 1367 if (dst->sin_family != AF_INET) { 1368 printf("ip_mloopback: bad address family %d\n", 1369 dst->sin_family); 1370 dst->sin_family = AF_INET; 1371 } 1372 #endif 1373 if_simloop(ifp, copym, dst->sin_family, 0); 1374 } 1375 } 1376