ip_output.c revision 37624
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 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)ip_output.c 8.3 (Berkeley) 1/21/94 34 * $Id: ip_output.c,v 1.78 1998/07/06 05:04:33 julian Exp $ 35 */ 36 37#define _IP_VHL 38 39#include "opt_ipfw.h" 40#include "opt_ipdivert.h" 41#include "opt_ipfilter.h" 42 43#include <sys/param.h> 44#include <sys/systm.h> 45#include <sys/malloc.h> 46#include <sys/mbuf.h> 47#include <sys/protosw.h> 48#include <sys/socket.h> 49#include <sys/socketvar.h> 50 51#include <net/if.h> 52#include <net/route.h> 53 54#include <netinet/in.h> 55#include <netinet/in_systm.h> 56#include <netinet/ip.h> 57#include <netinet/in_pcb.h> 58#include <netinet/in_var.h> 59#include <netinet/ip_var.h> 60 61#ifdef vax 62#include <machine/mtpr.h> 63#endif 64#include <machine/in_cksum.h> 65 66static MALLOC_DEFINE(M_IPMOPTS, "ip_moptions", "internet multicast options"); 67 68#if !defined(COMPAT_IPFW) || COMPAT_IPFW == 1 69#undef COMPAT_IPFW 70#define COMPAT_IPFW 1 71#else 72#undef COMPAT_IPFW 73#endif 74 75#ifdef IPFIREWALL_FORWARD_DEBUG 76#define print_ip(a) printf("%ld.%ld.%ld.%ld",(ntohl(a.s_addr)>>24)&0xFF,\ 77 (ntohl(a.s_addr)>>16)&0xFF,\ 78 (ntohl(a.s_addr)>>8)&0xFF,\ 79 (ntohl(a.s_addr))&0xFF); 80#endif 81 82u_short ip_id; 83 84static struct mbuf *ip_insertoptions __P((struct mbuf *, struct mbuf *, int *)); 85static void ip_mloopback 86 __P((struct ifnet *, struct mbuf *, struct sockaddr_in *, int)); 87static int ip_getmoptions 88 __P((int, struct ip_moptions *, struct mbuf **)); 89static int ip_pcbopts __P((struct mbuf **, struct mbuf *)); 90static int ip_setmoptions 91 __P((int, struct ip_moptions **, struct mbuf *)); 92 93#if defined(IPFILTER_LKM) || defined(IPFILTER) 94int ip_optcopy __P((struct ip *, struct ip *)); 95extern int (*fr_checkp) __P((struct ip *, int, struct ifnet *, int, struct mbuf **)); 96#else 97static int ip_optcopy __P((struct ip *, struct ip *)); 98#endif 99 100 101extern struct protosw inetsw[]; 102 103/* 104 * IP output. The packet in mbuf chain m contains a skeletal IP 105 * header (with len, off, ttl, proto, tos, src, dst). 106 * The mbuf chain containing the packet will be freed. 107 * The mbuf opt, if present, will not be freed. 108 */ 109int 110ip_output(m0, opt, ro, flags, imo) 111 struct mbuf *m0; 112 struct mbuf *opt; 113 struct route *ro; 114 int flags; 115 struct ip_moptions *imo; 116{ 117 struct ip *ip, *mhip; 118 struct ifnet *ifp; 119 struct mbuf *m = m0; 120 int hlen = sizeof (struct ip); 121 int len, off, error = 0; 122 struct sockaddr_in *dst; 123 struct in_ifaddr *ia; 124 int isbroadcast; 125#ifdef IPFIREWALL_FORWARD 126 int fwd_rewrite_src = 0; 127#endif 128 129#ifdef DIAGNOSTIC 130 if ((m->m_flags & M_PKTHDR) == 0) 131 panic("ip_output no HDR"); 132 if (!ro) 133 panic("ip_output no route, proto = %d", 134 mtod(m, struct ip *)->ip_p); 135#endif 136 if (opt) { 137 m = ip_insertoptions(m, opt, &len); 138 hlen = len; 139 } 140 ip = mtod(m, struct ip *); 141 /* 142 * Fill in IP header. 143 */ 144 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 145 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, hlen >> 2); 146 ip->ip_off &= IP_DF; 147 ip->ip_id = htons(ip_id++); 148 ipstat.ips_localout++; 149 } else { 150 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 151 } 152 153 dst = (struct sockaddr_in *)&ro->ro_dst; 154 /* 155 * If there is a cached route, 156 * check that it is to the same destination 157 * and is still up. If not, free it and try again. 158 */ 159 if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 || 160 dst->sin_addr.s_addr != ip->ip_dst.s_addr)) { 161 RTFREE(ro->ro_rt); 162 ro->ro_rt = (struct rtentry *)0; 163 } 164 if (ro->ro_rt == 0) { 165 dst->sin_family = AF_INET; 166 dst->sin_len = sizeof(*dst); 167 dst->sin_addr = ip->ip_dst; 168 } 169 /* 170 * If routing to interface only, 171 * short circuit routing lookup. 172 */ 173#define ifatoia(ifa) ((struct in_ifaddr *)(ifa)) 174#define sintosa(sin) ((struct sockaddr *)(sin)) 175 if (flags & IP_ROUTETOIF) { 176 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == 0 && 177 (ia = ifatoia(ifa_ifwithnet(sintosa(dst)))) == 0) { 178 ipstat.ips_noroute++; 179 error = ENETUNREACH; 180 goto bad; 181 } 182 ifp = ia->ia_ifp; 183 ip->ip_ttl = 1; 184 isbroadcast = in_broadcast(dst->sin_addr, ifp); 185 } else { 186 /* 187 * If this is the case, we probably don't want to allocate 188 * a protocol-cloned route since we didn't get one from the 189 * ULP. This lets TCP do its thing, while not burdening 190 * forwarding or ICMP with the overhead of cloning a route. 191 * Of course, we still want to do any cloning requested by 192 * the link layer, as this is probably required in all cases 193 * for correct operation (as it is for ARP). 194 */ 195 if (ro->ro_rt == 0) 196 rtalloc_ign(ro, RTF_PRCLONING); 197 if (ro->ro_rt == 0) { 198 ipstat.ips_noroute++; 199 error = EHOSTUNREACH; 200 goto bad; 201 } 202 ia = ifatoia(ro->ro_rt->rt_ifa); 203 ifp = ro->ro_rt->rt_ifp; 204 ro->ro_rt->rt_use++; 205 if (ro->ro_rt->rt_flags & RTF_GATEWAY) 206 dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway; 207 if (ro->ro_rt->rt_flags & RTF_HOST) 208 isbroadcast = (ro->ro_rt->rt_flags & RTF_BROADCAST); 209 else 210 isbroadcast = in_broadcast(dst->sin_addr, ifp); 211 } 212 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) { 213 struct in_multi *inm; 214 215 m->m_flags |= M_MCAST; 216 /* 217 * IP destination address is multicast. Make sure "dst" 218 * still points to the address in "ro". (It may have been 219 * changed to point to a gateway address, above.) 220 */ 221 dst = (struct sockaddr_in *)&ro->ro_dst; 222 /* 223 * See if the caller provided any multicast options 224 */ 225 if (imo != NULL) { 226 ip->ip_ttl = imo->imo_multicast_ttl; 227 if (imo->imo_multicast_ifp != NULL) 228 ifp = imo->imo_multicast_ifp; 229 if (imo->imo_multicast_vif != -1) 230 ip->ip_src.s_addr = 231 ip_mcast_src(imo->imo_multicast_vif); 232 } else 233 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 234 /* 235 * Confirm that the outgoing interface supports multicast. 236 */ 237 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) { 238 if ((ifp->if_flags & IFF_MULTICAST) == 0) { 239 ipstat.ips_noroute++; 240 error = ENETUNREACH; 241 goto bad; 242 } 243 } 244 /* 245 * If source address not specified yet, use address 246 * of outgoing interface. 247 */ 248 if (ip->ip_src.s_addr == INADDR_ANY) { 249 register struct in_ifaddr *ia1; 250 251 for (ia1 = in_ifaddrhead.tqh_first; ia1; 252 ia1 = ia1->ia_link.tqe_next) 253 if (ia1->ia_ifp == ifp) { 254 ip->ip_src = IA_SIN(ia1)->sin_addr; 255 break; 256 } 257 } 258 259 IN_LOOKUP_MULTI(ip->ip_dst, ifp, inm); 260 if (inm != NULL && 261 (imo == NULL || imo->imo_multicast_loop)) { 262 /* 263 * If we belong to the destination multicast group 264 * on the outgoing interface, and the caller did not 265 * forbid loopback, loop back a copy. 266 */ 267 ip_mloopback(ifp, m, dst, hlen); 268 } 269 else { 270 /* 271 * If we are acting as a multicast router, perform 272 * multicast forwarding as if the packet had just 273 * arrived on the interface to which we are about 274 * to send. The multicast forwarding function 275 * recursively calls this function, using the 276 * IP_FORWARDING flag to prevent infinite recursion. 277 * 278 * Multicasts that are looped back by ip_mloopback(), 279 * above, will be forwarded by the ip_input() routine, 280 * if necessary. 281 */ 282 if (ip_mrouter && (flags & IP_FORWARDING) == 0) { 283 /* 284 * Check if rsvp daemon is running. If not, don't 285 * set ip_moptions. This ensures that the packet 286 * is multicast and not just sent down one link 287 * as prescribed by rsvpd. 288 */ 289 if (!rsvp_on) 290 imo = NULL; 291 if (ip_mforward(ip, ifp, m, imo) != 0) { 292 m_freem(m); 293 goto done; 294 } 295 } 296 } 297 298 /* 299 * Multicasts with a time-to-live of zero may be looped- 300 * back, above, but must not be transmitted on a network. 301 * Also, multicasts addressed to the loopback interface 302 * are not sent -- the above call to ip_mloopback() will 303 * loop back a copy if this host actually belongs to the 304 * destination group on the loopback interface. 305 */ 306 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) { 307 m_freem(m); 308 goto done; 309 } 310 311 goto sendit; 312 } 313#ifndef notdef 314 /* 315 * If source address not specified yet, use address 316 * of outgoing interface. 317 */ 318 if (ip->ip_src.s_addr == INADDR_ANY) { 319 ip->ip_src = IA_SIN(ia)->sin_addr; 320#ifdef IPFIREWALL_FORWARD 321 /* Keep note that we did this - if the firewall changes 322 * the next-hop, our interface may change, changing the 323 * default source IP. It's a shame so much effort happens 324 * twice. Oh well. 325 */ 326 fwd_rewrite_src++; 327#endif /* IPFIREWALL_FORWARD */ 328 } 329#endif /* notdef */ 330 /* 331 * Verify that we have any chance at all of being able to queue 332 * the packet or packet fragments 333 */ 334 if ((ifp->if_snd.ifq_len + ip->ip_len / ifp->if_mtu + 1) >= 335 ifp->if_snd.ifq_maxlen) { 336 error = ENOBUFS; 337 goto bad; 338 } 339 340 /* 341 * Look for broadcast address and 342 * and verify user is allowed to send 343 * such a packet. 344 */ 345 if (isbroadcast) { 346 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 347 error = EADDRNOTAVAIL; 348 goto bad; 349 } 350 if ((flags & IP_ALLOWBROADCAST) == 0) { 351 error = EACCES; 352 goto bad; 353 } 354 /* don't allow broadcast messages to be fragmented */ 355 if ((u_short)ip->ip_len > ifp->if_mtu) { 356 error = EMSGSIZE; 357 goto bad; 358 } 359 m->m_flags |= M_BCAST; 360 } else { 361 m->m_flags &= ~M_BCAST; 362 } 363 364sendit: 365 /* 366 * IpHack's section. 367 * - Xlate: translate packet's addr/port (NAT). 368 * - Firewall: deny/allow/etc. 369 * - Wrap: fake packet's addr/port <unimpl.> 370 * - Encapsulate: put it in another IP and send out. <unimp.> 371 */ 372#if defined(IPFILTER) || defined(IPFILTER_LKM) 373 if (fr_checkp) { 374 struct mbuf *m1 = m; 375 376 if ((error = (*fr_checkp)(ip, hlen, ifp, 1, &m1)) || !m1) 377 goto done; 378 ip = mtod(m = m1, struct ip *); 379 } 380#endif 381 382#ifdef COMPAT_IPFW 383 if (ip_nat_ptr && !(*ip_nat_ptr)(&ip, &m, ifp, IP_NAT_OUT)) { 384 error = EACCES; 385 goto done; 386 } 387 388 /* 389 * Check with the firewall... 390 */ 391 if (ip_fw_chk_ptr) { 392#ifdef IPFIREWALL_FORWARD 393 struct sockaddr_in *old; 394 old = dst; 395#endif 396#ifdef IPDIVERT 397 ip_divert_port = (*ip_fw_chk_ptr)(&ip, 398 hlen, ifp, &ip_divert_cookie, &m, &dst); 399 if (ip_divert_port) { /* Divert packet */ 400 (*inetsw[ip_protox[IPPROTO_DIVERT]].pr_input)(m, 0); 401 goto done; 402 } 403#else /* !IPDIVERT */ 404 u_int16_t dummy = 0; 405 /* If ipfw says divert, we have to just drop packet */ 406 if ((*ip_fw_chk_ptr)(&ip, hlen, ifp, &dummy, &m, &dst)) { 407 m_freem(m); 408 goto done; 409 } 410#endif /* !IPDIVERT */ 411 if (!m) { 412 error = EACCES; 413 goto done; 414 } 415#ifdef IPFIREWALL_FORWARD 416 /* Here we check dst to make sure it's directly reachable on the 417 * interface we previously thought it was. 418 * If it isn't (which may be likely in some situations) we have 419 * to re-route it (ie, find a route for the next-hop and the 420 * associated interface) and set them here. This is nested 421 * forwarding which in most cases is undesirable, except where 422 * such control is nigh impossible. So we do it here. 423 * And I'm babbling. 424 */ 425 if (old != dst) { 426 struct in_ifaddr *ia; 427 428 /* It's changed... */ 429 /* There must be a better way to do this next line... */ 430 static struct route sro_fwd, *ro_fwd = &sro_fwd; 431#ifdef IPFIREWALL_FORWARD_DEBUG 432 printf("IPFIREWALL_FORWARD: New dst ip: "); 433 print_ip(dst->sin_addr); 434 printf("\n"); 435#endif 436 /* 437 * We need to figure out if we have been forwarded 438 * to a local socket. If so then we should somehow 439 * "loop back" to ip_input, and get directed to the 440 * PCB as if we had received this packet. This is 441 * because it may be dificult to identify the packets 442 * you want to forward until they are being output 443 * and have selected an interface. (e.g. locally 444 * initiated packets) If we used the loopback inteface, 445 * we would not be able to control what happens 446 * as the packet runs through ip_input() as 447 * it is done through a ISR. 448 */ 449 for (ia = TAILQ_FIRST(&in_ifaddrhead); ia; 450 ia = TAILQ_NEXT(ia, ia_link)) { 451 /* 452 * If the addr to forward to is one 453 * of ours, we pretend to 454 * be the destination for this packet. 455 */ 456 if (IA_SIN(ia)->sin_addr.s_addr == 457 dst->sin_addr.s_addr) 458 break; 459 } 460 if (ia) { 461 /* tell ip_input "dont filter" */ 462 ip_fw_fwd_addr = dst; 463 if (m->m_pkthdr.rcvif == NULL) 464 m->m_pkthdr.rcvif = ifunit("lo0"); 465 ip->ip_len = htons((u_short)ip->ip_len); 466 ip->ip_off = htons((u_short)ip->ip_off); 467 ip->ip_sum = 0; 468 if (ip->ip_vhl == IP_VHL_BORING) { 469 ip->ip_sum = in_cksum_hdr(ip); 470 } else { 471 ip->ip_sum = in_cksum(m, hlen); 472 } 473 ip_input(m); 474 goto done; 475 } 476 /* Some of the logic for this was 477 * nicked from above. 478 * 479 * This rewrites the cached route in a local PCB. 480 * Is this what we want to do? 481 */ 482 bcopy(dst, &ro_fwd->ro_dst, sizeof(*dst)); 483 484 ro_fwd->ro_rt = 0; 485 rtalloc_ign(ro_fwd, RTF_PRCLONING); 486 487 if (ro_fwd->ro_rt == 0) { 488 ipstat.ips_noroute++; 489 error = EHOSTUNREACH; 490 goto bad; 491 } 492 493 ia = ifatoia(ro_fwd->ro_rt->rt_ifa); 494 ifp = ro_fwd->ro_rt->rt_ifp; 495 ro_fwd->ro_rt->rt_use++; 496 if (ro_fwd->ro_rt->rt_flags & RTF_GATEWAY) 497 dst = (struct sockaddr_in *)ro_fwd->ro_rt->rt_gateway; 498 if (ro_fwd->ro_rt->rt_flags & RTF_HOST) 499 isbroadcast = 500 (ro_fwd->ro_rt->rt_flags & RTF_BROADCAST); 501 else 502 isbroadcast = in_broadcast(dst->sin_addr, ifp); 503 RTFREE(ro->ro_rt); 504 ro->ro_rt = ro_fwd->ro_rt; 505 dst = (struct sockaddr_in *)&ro_fwd->ro_dst; 506 507 /* 508 * If we added a default src ip earlier, 509 * which would have been gotten from the-then 510 * interface, do it again, from the new one. 511 */ 512 if (fwd_rewrite_src) 513 ip->ip_src = IA_SIN(ia)->sin_addr; 514 } 515#endif /* IPFIREWALL_FORWARD */ 516 } 517#endif /* COMPAT_IPFW */ 518 519 520 /* 521 * If small enough for interface, can just send directly. 522 */ 523 if ((u_short)ip->ip_len <= ifp->if_mtu) { 524 ip->ip_len = htons((u_short)ip->ip_len); 525 ip->ip_off = htons((u_short)ip->ip_off); 526 ip->ip_sum = 0; 527 if (ip->ip_vhl == IP_VHL_BORING) { 528 ip->ip_sum = in_cksum_hdr(ip); 529 } else { 530 ip->ip_sum = in_cksum(m, hlen); 531 } 532 error = (*ifp->if_output)(ifp, m, 533 (struct sockaddr *)dst, ro->ro_rt); 534 goto done; 535 } 536 /* 537 * Too large for interface; fragment if possible. 538 * Must be able to put at least 8 bytes per fragment. 539 */ 540 if (ip->ip_off & IP_DF) { 541 error = EMSGSIZE; 542 /* 543 * This case can happen if the user changed the MTU 544 * of an interface after enabling IP on it. Because 545 * most netifs don't keep track of routes pointing to 546 * them, there is no way for one to update all its 547 * routes when the MTU is changed. 548 */ 549 if ((ro->ro_rt->rt_flags & (RTF_UP | RTF_HOST)) 550 && !(ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) 551 && (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)) { 552 ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu; 553 } 554 ipstat.ips_cantfrag++; 555 goto bad; 556 } 557 len = (ifp->if_mtu - hlen) &~ 7; 558 if (len < 8) { 559 error = EMSGSIZE; 560 goto bad; 561 } 562 563 { 564 int mhlen, firstlen = len; 565 struct mbuf **mnext = &m->m_nextpkt; 566 567 /* 568 * Loop through length of segment after first fragment, 569 * make new header and copy data of each part and link onto chain. 570 */ 571 m0 = m; 572 mhlen = sizeof (struct ip); 573 for (off = hlen + len; off < (u_short)ip->ip_len; off += len) { 574 MGETHDR(m, M_DONTWAIT, MT_HEADER); 575 if (m == 0) { 576 error = ENOBUFS; 577 ipstat.ips_odropped++; 578 goto sendorfree; 579 } 580 m->m_data += max_linkhdr; 581 mhip = mtod(m, struct ip *); 582 *mhip = *ip; 583 if (hlen > sizeof (struct ip)) { 584 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 585 mhip->ip_vhl = IP_MAKE_VHL(IPVERSION, mhlen >> 2); 586 } 587 m->m_len = mhlen; 588 mhip->ip_off = ((off - hlen) >> 3) + (ip->ip_off & ~IP_MF); 589 if (ip->ip_off & IP_MF) 590 mhip->ip_off |= IP_MF; 591 if (off + len >= (u_short)ip->ip_len) 592 len = (u_short)ip->ip_len - off; 593 else 594 mhip->ip_off |= IP_MF; 595 mhip->ip_len = htons((u_short)(len + mhlen)); 596 m->m_next = m_copy(m0, off, len); 597 if (m->m_next == 0) { 598 (void) m_free(m); 599 error = ENOBUFS; /* ??? */ 600 ipstat.ips_odropped++; 601 goto sendorfree; 602 } 603 m->m_pkthdr.len = mhlen + len; 604 m->m_pkthdr.rcvif = (struct ifnet *)0; 605 mhip->ip_off = htons((u_short)mhip->ip_off); 606 mhip->ip_sum = 0; 607 if (mhip->ip_vhl == IP_VHL_BORING) { 608 mhip->ip_sum = in_cksum_hdr(mhip); 609 } else { 610 mhip->ip_sum = in_cksum(m, mhlen); 611 } 612 *mnext = m; 613 mnext = &m->m_nextpkt; 614 ipstat.ips_ofragments++; 615 } 616 /* 617 * Update first fragment by trimming what's been copied out 618 * and updating header, then send each fragment (in order). 619 */ 620 m = m0; 621 m_adj(m, hlen + firstlen - (u_short)ip->ip_len); 622 m->m_pkthdr.len = hlen + firstlen; 623 ip->ip_len = htons((u_short)m->m_pkthdr.len); 624 ip->ip_off = htons((u_short)(ip->ip_off | IP_MF)); 625 ip->ip_sum = 0; 626 if (ip->ip_vhl == IP_VHL_BORING) { 627 ip->ip_sum = in_cksum_hdr(ip); 628 } else { 629 ip->ip_sum = in_cksum(m, hlen); 630 } 631sendorfree: 632 for (m = m0; m; m = m0) { 633 m0 = m->m_nextpkt; 634 m->m_nextpkt = 0; 635 if (error == 0) 636 error = (*ifp->if_output)(ifp, m, 637 (struct sockaddr *)dst, ro->ro_rt); 638 else 639 m_freem(m); 640 } 641 642 if (error == 0) 643 ipstat.ips_fragmented++; 644 } 645done: 646 return (error); 647bad: 648 m_freem(m0); 649 goto done; 650} 651 652/* 653 * Insert IP options into preformed packet. 654 * Adjust IP destination as required for IP source routing, 655 * as indicated by a non-zero in_addr at the start of the options. 656 * 657 * XXX This routine assumes that the packet has no options in place. 658 */ 659static struct mbuf * 660ip_insertoptions(m, opt, phlen) 661 register struct mbuf *m; 662 struct mbuf *opt; 663 int *phlen; 664{ 665 register struct ipoption *p = mtod(opt, struct ipoption *); 666 struct mbuf *n; 667 register struct ip *ip = mtod(m, struct ip *); 668 unsigned optlen; 669 670 optlen = opt->m_len - sizeof(p->ipopt_dst); 671 if (optlen + (u_short)ip->ip_len > IP_MAXPACKET) 672 return (m); /* XXX should fail */ 673 if (p->ipopt_dst.s_addr) 674 ip->ip_dst = p->ipopt_dst; 675 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { 676 MGETHDR(n, M_DONTWAIT, MT_HEADER); 677 if (n == 0) 678 return (m); 679 n->m_pkthdr.len = m->m_pkthdr.len + optlen; 680 m->m_len -= sizeof(struct ip); 681 m->m_data += sizeof(struct ip); 682 n->m_next = m; 683 m = n; 684 m->m_len = optlen + sizeof(struct ip); 685 m->m_data += max_linkhdr; 686 (void)memcpy(mtod(m, void *), ip, sizeof(struct ip)); 687 } else { 688 m->m_data -= optlen; 689 m->m_len += optlen; 690 m->m_pkthdr.len += optlen; 691 ovbcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 692 } 693 ip = mtod(m, struct ip *); 694 bcopy(p->ipopt_list, ip + 1, optlen); 695 *phlen = sizeof(struct ip) + optlen; 696 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, *phlen >> 2); 697 ip->ip_len += optlen; 698 return (m); 699} 700 701/* 702 * Copy options from ip to jp, 703 * omitting those not copied during fragmentation. 704 */ 705#if !defined(IPFILTER) && !defined(IPFILTER_LKM) 706static 707#endif 708int 709ip_optcopy(ip, jp) 710 struct ip *ip, *jp; 711{ 712 register u_char *cp, *dp; 713 int opt, optlen, cnt; 714 715 cp = (u_char *)(ip + 1); 716 dp = (u_char *)(jp + 1); 717 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof (struct ip); 718 for (; cnt > 0; cnt -= optlen, cp += optlen) { 719 opt = cp[0]; 720 if (opt == IPOPT_EOL) 721 break; 722 if (opt == IPOPT_NOP) { 723 /* Preserve for IP mcast tunnel's LSRR alignment. */ 724 *dp++ = IPOPT_NOP; 725 optlen = 1; 726 continue; 727 } else 728 optlen = cp[IPOPT_OLEN]; 729 /* bogus lengths should have been caught by ip_dooptions */ 730 if (optlen > cnt) 731 optlen = cnt; 732 if (IPOPT_COPIED(opt)) { 733 bcopy(cp, dp, optlen); 734 dp += optlen; 735 } 736 } 737 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 738 *dp++ = IPOPT_EOL; 739 return (optlen); 740} 741 742/* 743 * IP socket option processing. 744 */ 745int 746ip_ctloutput(op, so, level, optname, mp, p) 747 int op; 748 struct socket *so; 749 int level, optname; 750 struct mbuf **mp; 751 struct proc *p; 752{ 753 register struct inpcb *inp = sotoinpcb(so); 754 register struct mbuf *m = *mp; 755 register int optval = 0; 756 int error = 0; 757 758 if (level != IPPROTO_IP) { 759 error = EINVAL; 760 if (op == PRCO_SETOPT && *mp) 761 (void) m_free(*mp); 762 } else switch (op) { 763 764 case PRCO_SETOPT: 765 switch (optname) { 766 case IP_OPTIONS: 767#ifdef notyet 768 case IP_RETOPTS: 769 return (ip_pcbopts(optname, &inp->inp_options, m)); 770#else 771 return (ip_pcbopts(&inp->inp_options, m)); 772#endif 773 774 case IP_TOS: 775 case IP_TTL: 776 case IP_RECVOPTS: 777 case IP_RECVRETOPTS: 778 case IP_RECVDSTADDR: 779 case IP_RECVIF: 780 if (m == 0 || m->m_len != sizeof(int)) 781 error = EINVAL; 782 else { 783 optval = *mtod(m, int *); 784 switch (optname) { 785 786 case IP_TOS: 787 inp->inp_ip_tos = optval; 788 break; 789 790 case IP_TTL: 791 inp->inp_ip_ttl = optval; 792 break; 793#define OPTSET(bit) \ 794 if (optval) \ 795 inp->inp_flags |= bit; \ 796 else \ 797 inp->inp_flags &= ~bit; 798 799 case IP_RECVOPTS: 800 OPTSET(INP_RECVOPTS); 801 break; 802 803 case IP_RECVRETOPTS: 804 OPTSET(INP_RECVRETOPTS); 805 break; 806 807 case IP_RECVDSTADDR: 808 OPTSET(INP_RECVDSTADDR); 809 break; 810 811 case IP_RECVIF: 812 OPTSET(INP_RECVIF); 813 break; 814 } 815 } 816 break; 817#undef OPTSET 818 819 case IP_MULTICAST_IF: 820 case IP_MULTICAST_VIF: 821 case IP_MULTICAST_TTL: 822 case IP_MULTICAST_LOOP: 823 case IP_ADD_MEMBERSHIP: 824 case IP_DROP_MEMBERSHIP: 825 error = ip_setmoptions(optname, &inp->inp_moptions, m); 826 break; 827 828 case IP_PORTRANGE: 829 if (m == 0 || m->m_len != sizeof(int)) 830 error = EINVAL; 831 else { 832 optval = *mtod(m, int *); 833 834 switch (optval) { 835 836 case IP_PORTRANGE_DEFAULT: 837 inp->inp_flags &= ~(INP_LOWPORT); 838 inp->inp_flags &= ~(INP_HIGHPORT); 839 break; 840 841 case IP_PORTRANGE_HIGH: 842 inp->inp_flags &= ~(INP_LOWPORT); 843 inp->inp_flags |= INP_HIGHPORT; 844 break; 845 846 case IP_PORTRANGE_LOW: 847 inp->inp_flags &= ~(INP_HIGHPORT); 848 inp->inp_flags |= INP_LOWPORT; 849 break; 850 851 default: 852 error = EINVAL; 853 break; 854 } 855 } 856 break; 857 858 default: 859 error = ENOPROTOOPT; 860 break; 861 } 862 if (m) 863 (void)m_free(m); 864 break; 865 866 case PRCO_GETOPT: 867 switch (optname) { 868 case IP_OPTIONS: 869 case IP_RETOPTS: 870 *mp = m = m_get(M_WAIT, MT_SOOPTS); 871 if (inp->inp_options) { 872 m->m_len = inp->inp_options->m_len; 873 bcopy(mtod(inp->inp_options, void *), 874 mtod(m, void *), m->m_len); 875 } else 876 m->m_len = 0; 877 break; 878 879 case IP_TOS: 880 case IP_TTL: 881 case IP_RECVOPTS: 882 case IP_RECVRETOPTS: 883 case IP_RECVDSTADDR: 884 case IP_RECVIF: 885 *mp = m = m_get(M_WAIT, MT_SOOPTS); 886 m->m_len = sizeof(int); 887 switch (optname) { 888 889 case IP_TOS: 890 optval = inp->inp_ip_tos; 891 break; 892 893 case IP_TTL: 894 optval = inp->inp_ip_ttl; 895 break; 896 897#define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 898 899 case IP_RECVOPTS: 900 optval = OPTBIT(INP_RECVOPTS); 901 break; 902 903 case IP_RECVRETOPTS: 904 optval = OPTBIT(INP_RECVRETOPTS); 905 break; 906 907 case IP_RECVDSTADDR: 908 optval = OPTBIT(INP_RECVDSTADDR); 909 break; 910 911 case IP_RECVIF: 912 optval = OPTBIT(INP_RECVIF); 913 break; 914 } 915 *mtod(m, int *) = optval; 916 break; 917 918 case IP_MULTICAST_IF: 919 case IP_MULTICAST_VIF: 920 case IP_MULTICAST_TTL: 921 case IP_MULTICAST_LOOP: 922 case IP_ADD_MEMBERSHIP: 923 case IP_DROP_MEMBERSHIP: 924 error = ip_getmoptions(optname, inp->inp_moptions, mp); 925 break; 926 927 case IP_PORTRANGE: 928 *mp = m = m_get(M_WAIT, MT_SOOPTS); 929 m->m_len = sizeof(int); 930 931 if (inp->inp_flags & INP_HIGHPORT) 932 optval = IP_PORTRANGE_HIGH; 933 else if (inp->inp_flags & INP_LOWPORT) 934 optval = IP_PORTRANGE_LOW; 935 else 936 optval = 0; 937 938 *mtod(m, int *) = optval; 939 break; 940 941 default: 942 error = ENOPROTOOPT; 943 break; 944 } 945 break; 946 } 947 return (error); 948} 949 950/* 951 * Set up IP options in pcb for insertion in output packets. 952 * Store in mbuf with pointer in pcbopt, adding pseudo-option 953 * with destination address if source routed. 954 */ 955static int 956#ifdef notyet 957ip_pcbopts(optname, pcbopt, m) 958 int optname; 959#else 960ip_pcbopts(pcbopt, m) 961#endif 962 struct mbuf **pcbopt; 963 register struct mbuf *m; 964{ 965 register int cnt, optlen; 966 register u_char *cp; 967 u_char opt; 968 969 /* turn off any old options */ 970 if (*pcbopt) 971 (void)m_free(*pcbopt); 972 *pcbopt = 0; 973 if (m == (struct mbuf *)0 || m->m_len == 0) { 974 /* 975 * Only turning off any previous options. 976 */ 977 if (m) 978 (void)m_free(m); 979 return (0); 980 } 981 982#ifndef vax 983 if (m->m_len % sizeof(int32_t)) 984 goto bad; 985#endif 986 /* 987 * IP first-hop destination address will be stored before 988 * actual options; move other options back 989 * and clear it when none present. 990 */ 991 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 992 goto bad; 993 cnt = m->m_len; 994 m->m_len += sizeof(struct in_addr); 995 cp = mtod(m, u_char *) + sizeof(struct in_addr); 996 ovbcopy(mtod(m, caddr_t), (caddr_t)cp, (unsigned)cnt); 997 bzero(mtod(m, caddr_t), sizeof(struct in_addr)); 998 999 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1000 opt = cp[IPOPT_OPTVAL]; 1001 if (opt == IPOPT_EOL) 1002 break; 1003 if (opt == IPOPT_NOP) 1004 optlen = 1; 1005 else { 1006 optlen = cp[IPOPT_OLEN]; 1007 if (optlen <= IPOPT_OLEN || optlen > cnt) 1008 goto bad; 1009 } 1010 switch (opt) { 1011 1012 default: 1013 break; 1014 1015 case IPOPT_LSRR: 1016 case IPOPT_SSRR: 1017 /* 1018 * user process specifies route as: 1019 * ->A->B->C->D 1020 * D must be our final destination (but we can't 1021 * check that since we may not have connected yet). 1022 * A is first hop destination, which doesn't appear in 1023 * actual IP option, but is stored before the options. 1024 */ 1025 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1026 goto bad; 1027 m->m_len -= sizeof(struct in_addr); 1028 cnt -= sizeof(struct in_addr); 1029 optlen -= sizeof(struct in_addr); 1030 cp[IPOPT_OLEN] = optlen; 1031 /* 1032 * Move first hop before start of options. 1033 */ 1034 bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), 1035 sizeof(struct in_addr)); 1036 /* 1037 * Then copy rest of options back 1038 * to close up the deleted entry. 1039 */ 1040 ovbcopy((caddr_t)(&cp[IPOPT_OFFSET+1] + 1041 sizeof(struct in_addr)), 1042 (caddr_t)&cp[IPOPT_OFFSET+1], 1043 (unsigned)cnt + sizeof(struct in_addr)); 1044 break; 1045 } 1046 } 1047 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1048 goto bad; 1049 *pcbopt = m; 1050 return (0); 1051 1052bad: 1053 (void)m_free(m); 1054 return (EINVAL); 1055} 1056 1057/* 1058 * Set the IP multicast options in response to user setsockopt(). 1059 */ 1060static int 1061ip_setmoptions(optname, imop, m) 1062 int optname; 1063 struct ip_moptions **imop; 1064 struct mbuf *m; 1065{ 1066 register int error = 0; 1067 u_char loop; 1068 register int i; 1069 struct in_addr addr; 1070 register struct ip_mreq *mreq; 1071 register struct ifnet *ifp; 1072 register struct ip_moptions *imo = *imop; 1073 struct route ro; 1074 register struct sockaddr_in *dst; 1075 int s; 1076 1077 if (imo == NULL) { 1078 /* 1079 * No multicast option buffer attached to the pcb; 1080 * allocate one and initialize to default values. 1081 */ 1082 imo = (struct ip_moptions*)malloc(sizeof(*imo), M_IPMOPTS, 1083 M_WAITOK); 1084 1085 if (imo == NULL) 1086 return (ENOBUFS); 1087 *imop = imo; 1088 imo->imo_multicast_ifp = NULL; 1089 imo->imo_multicast_vif = -1; 1090 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1091 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1092 imo->imo_num_memberships = 0; 1093 } 1094 1095 switch (optname) { 1096 /* store an index number for the vif you wanna use in the send */ 1097 case IP_MULTICAST_VIF: 1098 if (!legal_vif_num) { 1099 error = EOPNOTSUPP; 1100 break; 1101 } 1102 if (m == NULL || m->m_len != sizeof(int)) { 1103 error = EINVAL; 1104 break; 1105 } 1106 i = *(mtod(m, int *)); 1107 if (!legal_vif_num(i) && (i != -1)) { 1108 error = EINVAL; 1109 break; 1110 } 1111 imo->imo_multicast_vif = i; 1112 break; 1113 1114 case IP_MULTICAST_IF: 1115 /* 1116 * Select the interface for outgoing multicast packets. 1117 */ 1118 if (m == NULL || m->m_len != sizeof(struct in_addr)) { 1119 error = EINVAL; 1120 break; 1121 } 1122 addr = *(mtod(m, struct in_addr *)); 1123 /* 1124 * INADDR_ANY is used to remove a previous selection. 1125 * When no interface is selected, a default one is 1126 * chosen every time a multicast packet is sent. 1127 */ 1128 if (addr.s_addr == INADDR_ANY) { 1129 imo->imo_multicast_ifp = NULL; 1130 break; 1131 } 1132 /* 1133 * The selected interface is identified by its local 1134 * IP address. Find the interface and confirm that 1135 * it supports multicasting. 1136 */ 1137 s = splimp(); 1138 INADDR_TO_IFP(addr, ifp); 1139 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1140 splx(s); 1141 error = EADDRNOTAVAIL; 1142 break; 1143 } 1144 imo->imo_multicast_ifp = ifp; 1145 splx(s); 1146 break; 1147 1148 case IP_MULTICAST_TTL: 1149 /* 1150 * Set the IP time-to-live for outgoing multicast packets. 1151 */ 1152 if (m == NULL || m->m_len != 1) { 1153 error = EINVAL; 1154 break; 1155 } 1156 imo->imo_multicast_ttl = *(mtod(m, u_char *)); 1157 break; 1158 1159 case IP_MULTICAST_LOOP: 1160 /* 1161 * Set the loopback flag for outgoing multicast packets. 1162 * Must be zero or one. 1163 */ 1164 if (m == NULL || m->m_len != 1 || 1165 (loop = *(mtod(m, u_char *))) > 1) { 1166 error = EINVAL; 1167 break; 1168 } 1169 imo->imo_multicast_loop = loop; 1170 break; 1171 1172 case IP_ADD_MEMBERSHIP: 1173 /* 1174 * Add a multicast group membership. 1175 * Group must be a valid IP multicast address. 1176 */ 1177 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1178 error = EINVAL; 1179 break; 1180 } 1181 mreq = mtod(m, struct ip_mreq *); 1182 if (!IN_MULTICAST(ntohl(mreq->imr_multiaddr.s_addr))) { 1183 error = EINVAL; 1184 break; 1185 } 1186 s = splimp(); 1187 /* 1188 * If no interface address was provided, use the interface of 1189 * the route to the given multicast address. 1190 */ 1191 if (mreq->imr_interface.s_addr == INADDR_ANY) { 1192 bzero((caddr_t)&ro, sizeof(ro)); 1193 dst = (struct sockaddr_in *)&ro.ro_dst; 1194 dst->sin_len = sizeof(*dst); 1195 dst->sin_family = AF_INET; 1196 dst->sin_addr = mreq->imr_multiaddr; 1197 rtalloc(&ro); 1198 if (ro.ro_rt == NULL) { 1199 error = EADDRNOTAVAIL; 1200 splx(s); 1201 break; 1202 } 1203 ifp = ro.ro_rt->rt_ifp; 1204 rtfree(ro.ro_rt); 1205 } 1206 else { 1207 INADDR_TO_IFP(mreq->imr_interface, ifp); 1208 } 1209 1210 /* 1211 * See if we found an interface, and confirm that it 1212 * supports multicast. 1213 */ 1214 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1215 error = EADDRNOTAVAIL; 1216 splx(s); 1217 break; 1218 } 1219 /* 1220 * See if the membership already exists or if all the 1221 * membership slots are full. 1222 */ 1223 for (i = 0; i < imo->imo_num_memberships; ++i) { 1224 if (imo->imo_membership[i]->inm_ifp == ifp && 1225 imo->imo_membership[i]->inm_addr.s_addr 1226 == mreq->imr_multiaddr.s_addr) 1227 break; 1228 } 1229 if (i < imo->imo_num_memberships) { 1230 error = EADDRINUSE; 1231 splx(s); 1232 break; 1233 } 1234 if (i == IP_MAX_MEMBERSHIPS) { 1235 error = ETOOMANYREFS; 1236 splx(s); 1237 break; 1238 } 1239 /* 1240 * Everything looks good; add a new record to the multicast 1241 * address list for the given interface. 1242 */ 1243 if ((imo->imo_membership[i] = 1244 in_addmulti(&mreq->imr_multiaddr, ifp)) == NULL) { 1245 error = ENOBUFS; 1246 splx(s); 1247 break; 1248 } 1249 ++imo->imo_num_memberships; 1250 splx(s); 1251 break; 1252 1253 case IP_DROP_MEMBERSHIP: 1254 /* 1255 * Drop a multicast group membership. 1256 * Group must be a valid IP multicast address. 1257 */ 1258 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1259 error = EINVAL; 1260 break; 1261 } 1262 mreq = mtod(m, struct ip_mreq *); 1263 if (!IN_MULTICAST(ntohl(mreq->imr_multiaddr.s_addr))) { 1264 error = EINVAL; 1265 break; 1266 } 1267 1268 s = splimp(); 1269 /* 1270 * If an interface address was specified, get a pointer 1271 * to its ifnet structure. 1272 */ 1273 if (mreq->imr_interface.s_addr == INADDR_ANY) 1274 ifp = NULL; 1275 else { 1276 INADDR_TO_IFP(mreq->imr_interface, ifp); 1277 if (ifp == NULL) { 1278 error = EADDRNOTAVAIL; 1279 splx(s); 1280 break; 1281 } 1282 } 1283 /* 1284 * Find the membership in the membership array. 1285 */ 1286 for (i = 0; i < imo->imo_num_memberships; ++i) { 1287 if ((ifp == NULL || 1288 imo->imo_membership[i]->inm_ifp == ifp) && 1289 imo->imo_membership[i]->inm_addr.s_addr == 1290 mreq->imr_multiaddr.s_addr) 1291 break; 1292 } 1293 if (i == imo->imo_num_memberships) { 1294 error = EADDRNOTAVAIL; 1295 splx(s); 1296 break; 1297 } 1298 /* 1299 * Give up the multicast address record to which the 1300 * membership points. 1301 */ 1302 in_delmulti(imo->imo_membership[i]); 1303 /* 1304 * Remove the gap in the membership array. 1305 */ 1306 for (++i; i < imo->imo_num_memberships; ++i) 1307 imo->imo_membership[i-1] = imo->imo_membership[i]; 1308 --imo->imo_num_memberships; 1309 splx(s); 1310 break; 1311 1312 default: 1313 error = EOPNOTSUPP; 1314 break; 1315 } 1316 1317 /* 1318 * If all options have default values, no need to keep the mbuf. 1319 */ 1320 if (imo->imo_multicast_ifp == NULL && 1321 imo->imo_multicast_vif == -1 && 1322 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 1323 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 1324 imo->imo_num_memberships == 0) { 1325 free(*imop, M_IPMOPTS); 1326 *imop = NULL; 1327 } 1328 1329 return (error); 1330} 1331 1332/* 1333 * Return the IP multicast options in response to user getsockopt(). 1334 */ 1335static int 1336ip_getmoptions(optname, imo, mp) 1337 int optname; 1338 register struct ip_moptions *imo; 1339 register struct mbuf **mp; 1340{ 1341 u_char *ttl; 1342 u_char *loop; 1343 struct in_addr *addr; 1344 struct in_ifaddr *ia; 1345 1346 *mp = m_get(M_WAIT, MT_SOOPTS); 1347 1348 switch (optname) { 1349 1350 case IP_MULTICAST_VIF: 1351 if (imo != NULL) 1352 *(mtod(*mp, int *)) = imo->imo_multicast_vif; 1353 else 1354 *(mtod(*mp, int *)) = -1; 1355 (*mp)->m_len = sizeof(int); 1356 return(0); 1357 1358 case IP_MULTICAST_IF: 1359 addr = mtod(*mp, struct in_addr *); 1360 (*mp)->m_len = sizeof(struct in_addr); 1361 if (imo == NULL || imo->imo_multicast_ifp == NULL) 1362 addr->s_addr = INADDR_ANY; 1363 else { 1364 IFP_TO_IA(imo->imo_multicast_ifp, ia); 1365 addr->s_addr = (ia == NULL) ? INADDR_ANY 1366 : IA_SIN(ia)->sin_addr.s_addr; 1367 } 1368 return (0); 1369 1370 case IP_MULTICAST_TTL: 1371 ttl = mtod(*mp, u_char *); 1372 (*mp)->m_len = 1; 1373 *ttl = (imo == NULL) ? IP_DEFAULT_MULTICAST_TTL 1374 : imo->imo_multicast_ttl; 1375 return (0); 1376 1377 case IP_MULTICAST_LOOP: 1378 loop = mtod(*mp, u_char *); 1379 (*mp)->m_len = 1; 1380 *loop = (imo == NULL) ? IP_DEFAULT_MULTICAST_LOOP 1381 : imo->imo_multicast_loop; 1382 return (0); 1383 1384 default: 1385 return (EOPNOTSUPP); 1386 } 1387} 1388 1389/* 1390 * Discard the IP multicast options. 1391 */ 1392void 1393ip_freemoptions(imo) 1394 register struct ip_moptions *imo; 1395{ 1396 register int i; 1397 1398 if (imo != NULL) { 1399 for (i = 0; i < imo->imo_num_memberships; ++i) 1400 in_delmulti(imo->imo_membership[i]); 1401 free(imo, M_IPMOPTS); 1402 } 1403} 1404 1405/* 1406 * Routine called from ip_output() to loop back a copy of an IP multicast 1407 * packet to the input queue of a specified interface. Note that this 1408 * calls the output routine of the loopback "driver", but with an interface 1409 * pointer that might NOT be a loopback interface -- evil, but easier than 1410 * replicating that code here. 1411 */ 1412static void 1413ip_mloopback(ifp, m, dst, hlen) 1414 struct ifnet *ifp; 1415 register struct mbuf *m; 1416 register struct sockaddr_in *dst; 1417 int hlen; 1418{ 1419 register struct ip *ip; 1420 struct mbuf *copym; 1421 1422 copym = m_copy(m, 0, M_COPYALL); 1423 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen)) 1424 copym = m_pullup(copym, hlen); 1425 if (copym != NULL) { 1426 /* 1427 * We don't bother to fragment if the IP length is greater 1428 * than the interface's MTU. Can this possibly matter? 1429 */ 1430 ip = mtod(copym, struct ip *); 1431 ip->ip_len = htons((u_short)ip->ip_len); 1432 ip->ip_off = htons((u_short)ip->ip_off); 1433 ip->ip_sum = 0; 1434 if (ip->ip_vhl == IP_VHL_BORING) { 1435 ip->ip_sum = in_cksum_hdr(ip); 1436 } else { 1437 ip->ip_sum = in_cksum(copym, hlen); 1438 } 1439 /* 1440 * NB: 1441 * It's not clear whether there are any lingering 1442 * reentrancy problems in other areas which might 1443 * be exposed by using ip_input directly (in 1444 * particular, everything which modifies the packet 1445 * in-place). Yet another option is using the 1446 * protosw directly to deliver the looped back 1447 * packet. For the moment, we'll err on the side 1448 * of safety by using if_simloop(). 1449 */ 1450#if 1 /* XXX */ 1451 if (dst->sin_family != AF_INET) { 1452 printf("ip_mloopback: bad address family %d\n", 1453 dst->sin_family); 1454 dst->sin_family = AF_INET; 1455 } 1456#endif 1457 1458#ifdef notdef 1459 copym->m_pkthdr.rcvif = ifp; 1460 ip_input(copym); 1461#else 1462 if_simloop(ifp, copym, (struct sockaddr *)dst, 0); 1463#endif 1464 } 1465} 1466