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 1.79 1998/07/13 12:12:25 bde 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 66 static 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 82 u_short ip_id; 83 84 static struct mbuf *ip_insertoptions __P((struct mbuf *, struct mbuf *, int *)); 85 static void ip_mloopback 86 __P((struct ifnet *, struct mbuf *, struct sockaddr_in *, int)); 87 static int ip_getmoptions 88 __P((int, struct ip_moptions *, struct mbuf **)); 89 static int ip_pcbopts __P((struct mbuf **, struct mbuf *)); 90 static int ip_setmoptions 91 __P((int, struct ip_moptions **, struct mbuf *)); 92 93 #if defined(IPFILTER_LKM) || defined(IPFILTER) 94 int ip_optcopy __P((struct ip *, struct ip *)); 95 extern int (*fr_checkp) __P((struct ip *, int, struct ifnet *, int, struct mbuf **)); 96 #else 97 static int ip_optcopy __P((struct ip *, struct ip *)); 98 #endif 99 100 101 extern 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 */ 109 int 110 ip_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 } 363 364 sendit: 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 = dst; 394 #endif 395 #ifdef IPDIVERT 396 ip_divert_port = (*ip_fw_chk_ptr)(&ip, 397 hlen, ifp, &ip_divert_cookie, &m, &dst); 398 if (ip_divert_port) { /* Divert packet */ 399 (*inetsw[ip_protox[IPPROTO_DIVERT]].pr_input)(m, 0); 400 goto done; 401 } 402 #else /* !IPDIVERT */ 403 u_int16_t dummy = 0; 404 /* If ipfw says divert, we have to just drop packet */ 405 if ((*ip_fw_chk_ptr)(&ip, hlen, ifp, &dummy, &m, &dst)) { 406 m_freem(m); 407 goto done; 408 } 409 #endif /* !IPDIVERT */ 410 if (!m) { 411 error = EACCES; 412 goto done; 413 } 414 #ifdef IPFIREWALL_FORWARD 415 /* Here we check dst to make sure it's directly reachable on the 416 * interface we previously thought it was. 417 * If it isn't (which may be likely in some situations) we have 418 * to re-route it (ie, find a route for the next-hop and the 419 * associated interface) and set them here. This is nested 420 * forwarding which in most cases is undesirable, except where 421 * such control is nigh impossible. So we do it here. 422 * And I'm babbling. 423 */ 424 if (old != dst) { 425 struct in_ifaddr *ia; 426 427 /* It's changed... */ 428 /* There must be a better way to do this next line... */ 429 static struct route sro_fwd, *ro_fwd = &sro_fwd; 430 #ifdef IPFIREWALL_FORWARD_DEBUG 431 printf("IPFIREWALL_FORWARD: New dst ip: "); 432 print_ip(dst->sin_addr); 433 printf("\n"); 434 #endif 435 /* 436 * We need to figure out if we have been forwarded 437 * to a local socket. If so then we should somehow 438 * "loop back" to ip_input, and get directed to the 439 * PCB as if we had received this packet. This is 440 * because it may be dificult to identify the packets 441 * you want to forward until they are being output 442 * and have selected an interface. (e.g. locally 443 * initiated packets) If we used the loopback inteface, 444 * we would not be able to control what happens 445 * as the packet runs through ip_input() as 446 * it is done through a ISR. 447 */ 448 for (ia = TAILQ_FIRST(&in_ifaddrhead); ia; 449 ia = TAILQ_NEXT(ia, ia_link)) { 450 /* 451 * If the addr to forward to is one 452 * of ours, we pretend to 453 * be the destination for this packet. 454 */ 455 if (IA_SIN(ia)->sin_addr.s_addr == 456 dst->sin_addr.s_addr) 457 break; 458 } 459 if (ia) { 460 /* tell ip_input "dont filter" */ 461 ip_fw_fwd_addr = dst; 462 if (m->m_pkthdr.rcvif == NULL) 463 m->m_pkthdr.rcvif = ifunit("lo0"); 464 ip->ip_len = htons((u_short)ip->ip_len); 465 ip->ip_off = htons((u_short)ip->ip_off); 466 ip->ip_sum = 0; 467 if (ip->ip_vhl == IP_VHL_BORING) { 468 ip->ip_sum = in_cksum_hdr(ip); 469 } else { 470 ip->ip_sum = in_cksum(m, hlen); 471 } 472 ip_input(m); 473 goto done; 474 } 475 /* Some of the logic for this was 476 * nicked from above. 477 * 478 * This rewrites the cached route in a local PCB. 479 * Is this what we want to do? 480 */ 481 bcopy(dst, &ro_fwd->ro_dst, sizeof(*dst)); 482 483 ro_fwd->ro_rt = 0; 484 rtalloc_ign(ro_fwd, RTF_PRCLONING); 485 486 if (ro_fwd->ro_rt == 0) { 487 ipstat.ips_noroute++; 488 error = EHOSTUNREACH; 489 goto bad; 490 } 491 492 ia = ifatoia(ro_fwd->ro_rt->rt_ifa); 493 ifp = ro_fwd->ro_rt->rt_ifp; 494 ro_fwd->ro_rt->rt_use++; 495 if (ro_fwd->ro_rt->rt_flags & RTF_GATEWAY) 496 dst = (struct sockaddr_in *)ro_fwd->ro_rt->rt_gateway; 497 if (ro_fwd->ro_rt->rt_flags & RTF_HOST) 498 isbroadcast = 499 (ro_fwd->ro_rt->rt_flags & RTF_BROADCAST); 500 else 501 isbroadcast = in_broadcast(dst->sin_addr, ifp); 502 RTFREE(ro->ro_rt); 503 ro->ro_rt = ro_fwd->ro_rt; 504 dst = (struct sockaddr_in *)&ro_fwd->ro_dst; 505 506 /* 507 * If we added a default src ip earlier, 508 * which would have been gotten from the-then 509 * interface, do it again, from the new one. 510 */ 511 if (fwd_rewrite_src) 512 ip->ip_src = IA_SIN(ia)->sin_addr; 513 } 514 #endif /* IPFIREWALL_FORWARD */ 515 } 516 #endif /* COMPAT_IPFW */ 517 518 519 /* 520 * If small enough for interface, can just send directly. 521 */ 522 if ((u_short)ip->ip_len <= ifp->if_mtu) { 523 ip->ip_len = htons((u_short)ip->ip_len); 524 ip->ip_off = htons((u_short)ip->ip_off); 525 ip->ip_sum = 0; 526 if (ip->ip_vhl == IP_VHL_BORING) { 527 ip->ip_sum = in_cksum_hdr(ip); 528 } else { 529 ip->ip_sum = in_cksum(m, hlen); 530 } 531 error = (*ifp->if_output)(ifp, m, 532 (struct sockaddr *)dst, ro->ro_rt); 533 goto done; 534 } 535 /* 536 * Too large for interface; fragment if possible. 537 * Must be able to put at least 8 bytes per fragment. 538 */ 539 if (ip->ip_off & IP_DF) { 540 error = EMSGSIZE; 541 /* 542 * This case can happen if the user changed the MTU 543 * of an interface after enabling IP on it. Because 544 * most netifs don't keep track of routes pointing to 545 * them, there is no way for one to update all its 546 * routes when the MTU is changed. 547 */ 548 if ((ro->ro_rt->rt_flags & (RTF_UP | RTF_HOST)) 549 && !(ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) 550 && (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)) { 551 ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu; 552 } 553 ipstat.ips_cantfrag++; 554 goto bad; 555 } 556 len = (ifp->if_mtu - hlen) &~ 7; 557 if (len < 8) { 558 error = EMSGSIZE; 559 goto bad; 560 } 561 562 { 563 int mhlen, firstlen = len; 564 struct mbuf **mnext = &m->m_nextpkt; 565 566 /* 567 * Loop through length of segment after first fragment, 568 * make new header and copy data of each part and link onto chain. 569 */ 570 m0 = m; 571 mhlen = sizeof (struct ip); 572 for (off = hlen + len; off < (u_short)ip->ip_len; off += len) { 573 MGETHDR(m, M_DONTWAIT, MT_HEADER); 574 if (m == 0) { 575 error = ENOBUFS; 576 ipstat.ips_odropped++; 577 goto sendorfree; 578 } 579 m->m_data += max_linkhdr; 580 mhip = mtod(m, struct ip *); 581 *mhip = *ip; 582 if (hlen > sizeof (struct ip)) { 583 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 584 mhip->ip_vhl = IP_MAKE_VHL(IPVERSION, mhlen >> 2); 585 } 586 m->m_len = mhlen; 587 mhip->ip_off = ((off - hlen) >> 3) + (ip->ip_off & ~IP_MF); 588 if (ip->ip_off & IP_MF) 589 mhip->ip_off |= IP_MF; 590 if (off + len >= (u_short)ip->ip_len) 591 len = (u_short)ip->ip_len - off; 592 else 593 mhip->ip_off |= IP_MF; 594 mhip->ip_len = htons((u_short)(len + mhlen)); 595 m->m_next = m_copy(m0, off, len); 596 if (m->m_next == 0) { 597 (void) m_free(m); 598 error = ENOBUFS; /* ??? */ 599 ipstat.ips_odropped++; 600 goto sendorfree; 601 } 602 m->m_pkthdr.len = mhlen + len; 603 m->m_pkthdr.rcvif = (struct ifnet *)0; 604 mhip->ip_off = htons((u_short)mhip->ip_off); 605 mhip->ip_sum = 0; 606 if (mhip->ip_vhl == IP_VHL_BORING) { 607 mhip->ip_sum = in_cksum_hdr(mhip); 608 } else { 609 mhip->ip_sum = in_cksum(m, mhlen); 610 } 611 *mnext = m; 612 mnext = &m->m_nextpkt; 613 ipstat.ips_ofragments++; 614 } 615 /* 616 * Update first fragment by trimming what's been copied out 617 * and updating header, then send each fragment (in order). 618 */ 619 m = m0; 620 m_adj(m, hlen + firstlen - (u_short)ip->ip_len); 621 m->m_pkthdr.len = hlen + firstlen; 622 ip->ip_len = htons((u_short)m->m_pkthdr.len); 623 ip->ip_off = htons((u_short)(ip->ip_off | IP_MF)); 624 ip->ip_sum = 0; 625 if (ip->ip_vhl == IP_VHL_BORING) { 626 ip->ip_sum = in_cksum_hdr(ip); 627 } else { 628 ip->ip_sum = in_cksum(m, hlen); 629 } 630 sendorfree: 631 for (m = m0; m; m = m0) { 632 m0 = m->m_nextpkt; 633 m->m_nextpkt = 0; 634 if (error == 0) 635 error = (*ifp->if_output)(ifp, m, 636 (struct sockaddr *)dst, ro->ro_rt); 637 else 638 m_freem(m); 639 } 640 641 if (error == 0) 642 ipstat.ips_fragmented++; 643 } 644 done: 645 return (error); 646 bad: 647 m_freem(m0); 648 goto done; 649 } 650 651 /* 652 * Insert IP options into preformed packet. 653 * Adjust IP destination as required for IP source routing, 654 * as indicated by a non-zero in_addr at the start of the options. 655 * 656 * XXX This routine assumes that the packet has no options in place. 657 */ 658 static struct mbuf * 659 ip_insertoptions(m, opt, phlen) 660 register struct mbuf *m; 661 struct mbuf *opt; 662 int *phlen; 663 { 664 register struct ipoption *p = mtod(opt, struct ipoption *); 665 struct mbuf *n; 666 register struct ip *ip = mtod(m, struct ip *); 667 unsigned optlen; 668 669 optlen = opt->m_len - sizeof(p->ipopt_dst); 670 if (optlen + (u_short)ip->ip_len > IP_MAXPACKET) 671 return (m); /* XXX should fail */ 672 if (p->ipopt_dst.s_addr) 673 ip->ip_dst = p->ipopt_dst; 674 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { 675 MGETHDR(n, M_DONTWAIT, MT_HEADER); 676 if (n == 0) 677 return (m); 678 n->m_pkthdr.len = m->m_pkthdr.len + optlen; 679 m->m_len -= sizeof(struct ip); 680 m->m_data += sizeof(struct ip); 681 n->m_next = m; 682 m = n; 683 m->m_len = optlen + sizeof(struct ip); 684 m->m_data += max_linkhdr; 685 (void)memcpy(mtod(m, void *), ip, sizeof(struct ip)); 686 } else { 687 m->m_data -= optlen; 688 m->m_len += optlen; 689 m->m_pkthdr.len += optlen; 690 ovbcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 691 } 692 ip = mtod(m, struct ip *); 693 bcopy(p->ipopt_list, ip + 1, optlen); 694 *phlen = sizeof(struct ip) + optlen; 695 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, *phlen >> 2); 696 ip->ip_len += optlen; 697 return (m); 698 } 699 700 /* 701 * Copy options from ip to jp, 702 * omitting those not copied during fragmentation. 703 */ 704 #if !defined(IPFILTER) && !defined(IPFILTER_LKM) 705 static 706 #endif 707 int 708 ip_optcopy(ip, jp) 709 struct ip *ip, *jp; 710 { 711 register u_char *cp, *dp; 712 int opt, optlen, cnt; 713 714 cp = (u_char *)(ip + 1); 715 dp = (u_char *)(jp + 1); 716 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof (struct ip); 717 for (; cnt > 0; cnt -= optlen, cp += optlen) { 718 opt = cp[0]; 719 if (opt == IPOPT_EOL) 720 break; 721 if (opt == IPOPT_NOP) { 722 /* Preserve for IP mcast tunnel's LSRR alignment. */ 723 *dp++ = IPOPT_NOP; 724 optlen = 1; 725 continue; 726 } else 727 optlen = cp[IPOPT_OLEN]; 728 /* bogus lengths should have been caught by ip_dooptions */ 729 if (optlen > cnt) 730 optlen = cnt; 731 if (IPOPT_COPIED(opt)) { 732 bcopy(cp, dp, optlen); 733 dp += optlen; 734 } 735 } 736 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 737 *dp++ = IPOPT_EOL; 738 return (optlen); 739 } 740 741 /* 742 * IP socket option processing. 743 */ 744 int 745 ip_ctloutput(op, so, level, optname, mp, p) 746 int op; 747 struct socket *so; 748 int level, optname; 749 struct mbuf **mp; 750 struct proc *p; 751 { 752 register struct inpcb *inp = sotoinpcb(so); 753 register struct mbuf *m = *mp; 754 register int optval = 0; 755 int error = 0; 756 757 if (level != IPPROTO_IP) { 758 error = EINVAL; 759 if (op == PRCO_SETOPT && *mp) 760 (void) m_free(*mp); 761 } else switch (op) { 762 763 case PRCO_SETOPT: 764 switch (optname) { 765 case IP_OPTIONS: 766 #ifdef notyet 767 case IP_RETOPTS: 768 return (ip_pcbopts(optname, &inp->inp_options, m)); 769 #else 770 return (ip_pcbopts(&inp->inp_options, m)); 771 #endif 772 773 case IP_TOS: 774 case IP_TTL: 775 case IP_RECVOPTS: 776 case IP_RECVRETOPTS: 777 case IP_RECVDSTADDR: 778 case IP_RECVIF: 779 if (m == 0 || m->m_len != sizeof(int)) 780 error = EINVAL; 781 else { 782 optval = *mtod(m, int *); 783 switch (optname) { 784 785 case IP_TOS: 786 inp->inp_ip_tos = optval; 787 break; 788 789 case IP_TTL: 790 inp->inp_ip_ttl = optval; 791 break; 792 #define OPTSET(bit) \ 793 if (optval) \ 794 inp->inp_flags |= bit; \ 795 else \ 796 inp->inp_flags &= ~bit; 797 798 case IP_RECVOPTS: 799 OPTSET(INP_RECVOPTS); 800 break; 801 802 case IP_RECVRETOPTS: 803 OPTSET(INP_RECVRETOPTS); 804 break; 805 806 case IP_RECVDSTADDR: 807 OPTSET(INP_RECVDSTADDR); 808 break; 809 810 case IP_RECVIF: 811 OPTSET(INP_RECVIF); 812 break; 813 } 814 } 815 break; 816 #undef OPTSET 817 818 case IP_MULTICAST_IF: 819 case IP_MULTICAST_VIF: 820 case IP_MULTICAST_TTL: 821 case IP_MULTICAST_LOOP: 822 case IP_ADD_MEMBERSHIP: 823 case IP_DROP_MEMBERSHIP: 824 error = ip_setmoptions(optname, &inp->inp_moptions, m); 825 break; 826 827 case IP_PORTRANGE: 828 if (m == 0 || m->m_len != sizeof(int)) 829 error = EINVAL; 830 else { 831 optval = *mtod(m, int *); 832 833 switch (optval) { 834 835 case IP_PORTRANGE_DEFAULT: 836 inp->inp_flags &= ~(INP_LOWPORT); 837 inp->inp_flags &= ~(INP_HIGHPORT); 838 break; 839 840 case IP_PORTRANGE_HIGH: 841 inp->inp_flags &= ~(INP_LOWPORT); 842 inp->inp_flags |= INP_HIGHPORT; 843 break; 844 845 case IP_PORTRANGE_LOW: 846 inp->inp_flags &= ~(INP_HIGHPORT); 847 inp->inp_flags |= INP_LOWPORT; 848 break; 849 850 default: 851 error = EINVAL; 852 break; 853 } 854 } 855 break; 856 857 default: 858 error = ENOPROTOOPT; 859 break; 860 } 861 if (m) 862 (void)m_free(m); 863 break; 864 865 case PRCO_GETOPT: 866 switch (optname) { 867 case IP_OPTIONS: 868 case IP_RETOPTS: 869 *mp = m = m_get(M_WAIT, MT_SOOPTS); 870 if (inp->inp_options) { 871 m->m_len = inp->inp_options->m_len; 872 bcopy(mtod(inp->inp_options, void *), 873 mtod(m, void *), m->m_len); 874 } else 875 m->m_len = 0; 876 break; 877 878 case IP_TOS: 879 case IP_TTL: 880 case IP_RECVOPTS: 881 case IP_RECVRETOPTS: 882 case IP_RECVDSTADDR: 883 case IP_RECVIF: 884 *mp = m = m_get(M_WAIT, MT_SOOPTS); 885 m->m_len = sizeof(int); 886 switch (optname) { 887 888 case IP_TOS: 889 optval = inp->inp_ip_tos; 890 break; 891 892 case IP_TTL: 893 optval = inp->inp_ip_ttl; 894 break; 895 896 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 897 898 case IP_RECVOPTS: 899 optval = OPTBIT(INP_RECVOPTS); 900 break; 901 902 case IP_RECVRETOPTS: 903 optval = OPTBIT(INP_RECVRETOPTS); 904 break; 905 906 case IP_RECVDSTADDR: 907 optval = OPTBIT(INP_RECVDSTADDR); 908 break; 909 910 case IP_RECVIF: 911 optval = OPTBIT(INP_RECVIF); 912 break; 913 } 914 *mtod(m, int *) = optval; 915 break; 916 917 case IP_MULTICAST_IF: 918 case IP_MULTICAST_VIF: 919 case IP_MULTICAST_TTL: 920 case IP_MULTICAST_LOOP: 921 case IP_ADD_MEMBERSHIP: 922 case IP_DROP_MEMBERSHIP: 923 error = ip_getmoptions(optname, inp->inp_moptions, mp); 924 break; 925 926 case IP_PORTRANGE: 927 *mp = m = m_get(M_WAIT, MT_SOOPTS); 928 m->m_len = sizeof(int); 929 930 if (inp->inp_flags & INP_HIGHPORT) 931 optval = IP_PORTRANGE_HIGH; 932 else if (inp->inp_flags & INP_LOWPORT) 933 optval = IP_PORTRANGE_LOW; 934 else 935 optval = 0; 936 937 *mtod(m, int *) = optval; 938 break; 939 940 default: 941 error = ENOPROTOOPT; 942 break; 943 } 944 break; 945 } 946 return (error); 947 } 948 949 /* 950 * Set up IP options in pcb for insertion in output packets. 951 * Store in mbuf with pointer in pcbopt, adding pseudo-option 952 * with destination address if source routed. 953 */ 954 static int 955 #ifdef notyet 956 ip_pcbopts(optname, pcbopt, m) 957 int optname; 958 #else 959 ip_pcbopts(pcbopt, m) 960 #endif 961 struct mbuf **pcbopt; 962 register struct mbuf *m; 963 { 964 register int cnt, optlen; 965 register u_char *cp; 966 u_char opt; 967 968 /* turn off any old options */ 969 if (*pcbopt) 970 (void)m_free(*pcbopt); 971 *pcbopt = 0; 972 if (m == (struct mbuf *)0 || m->m_len == 0) { 973 /* 974 * Only turning off any previous options. 975 */ 976 if (m) 977 (void)m_free(m); 978 return (0); 979 } 980 981 #ifndef vax 982 if (m->m_len % sizeof(int32_t)) 983 goto bad; 984 #endif 985 /* 986 * IP first-hop destination address will be stored before 987 * actual options; move other options back 988 * and clear it when none present. 989 */ 990 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 991 goto bad; 992 cnt = m->m_len; 993 m->m_len += sizeof(struct in_addr); 994 cp = mtod(m, u_char *) + sizeof(struct in_addr); 995 ovbcopy(mtod(m, caddr_t), (caddr_t)cp, (unsigned)cnt); 996 bzero(mtod(m, caddr_t), sizeof(struct in_addr)); 997 998 for (; cnt > 0; cnt -= optlen, cp += optlen) { 999 opt = cp[IPOPT_OPTVAL]; 1000 if (opt == IPOPT_EOL) 1001 break; 1002 if (opt == IPOPT_NOP) 1003 optlen = 1; 1004 else { 1005 optlen = cp[IPOPT_OLEN]; 1006 if (optlen <= IPOPT_OLEN || optlen > cnt) 1007 goto bad; 1008 } 1009 switch (opt) { 1010 1011 default: 1012 break; 1013 1014 case IPOPT_LSRR: 1015 case IPOPT_SSRR: 1016 /* 1017 * user process specifies route as: 1018 * ->A->B->C->D 1019 * D must be our final destination (but we can't 1020 * check that since we may not have connected yet). 1021 * A is first hop destination, which doesn't appear in 1022 * actual IP option, but is stored before the options. 1023 */ 1024 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1025 goto bad; 1026 m->m_len -= sizeof(struct in_addr); 1027 cnt -= sizeof(struct in_addr); 1028 optlen -= sizeof(struct in_addr); 1029 cp[IPOPT_OLEN] = optlen; 1030 /* 1031 * Move first hop before start of options. 1032 */ 1033 bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), 1034 sizeof(struct in_addr)); 1035 /* 1036 * Then copy rest of options back 1037 * to close up the deleted entry. 1038 */ 1039 ovbcopy((caddr_t)(&cp[IPOPT_OFFSET+1] + 1040 sizeof(struct in_addr)), 1041 (caddr_t)&cp[IPOPT_OFFSET+1], 1042 (unsigned)cnt + sizeof(struct in_addr)); 1043 break; 1044 } 1045 } 1046 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1047 goto bad; 1048 *pcbopt = m; 1049 return (0); 1050 1051 bad: 1052 (void)m_free(m); 1053 return (EINVAL); 1054 } 1055 1056 /* 1057 * Set the IP multicast options in response to user setsockopt(). 1058 */ 1059 static int 1060 ip_setmoptions(optname, imop, m) 1061 int optname; 1062 struct ip_moptions **imop; 1063 struct mbuf *m; 1064 { 1065 register int error = 0; 1066 u_char loop; 1067 register int i; 1068 struct in_addr addr; 1069 register struct ip_mreq *mreq; 1070 register struct ifnet *ifp; 1071 register struct ip_moptions *imo = *imop; 1072 struct route ro; 1073 register struct sockaddr_in *dst; 1074 int s; 1075 1076 if (imo == NULL) { 1077 /* 1078 * No multicast option buffer attached to the pcb; 1079 * allocate one and initialize to default values. 1080 */ 1081 imo = (struct ip_moptions*)malloc(sizeof(*imo), M_IPMOPTS, 1082 M_WAITOK); 1083 1084 if (imo == NULL) 1085 return (ENOBUFS); 1086 *imop = imo; 1087 imo->imo_multicast_ifp = NULL; 1088 imo->imo_multicast_vif = -1; 1089 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1090 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1091 imo->imo_num_memberships = 0; 1092 } 1093 1094 switch (optname) { 1095 /* store an index number for the vif you wanna use in the send */ 1096 case IP_MULTICAST_VIF: 1097 if (!legal_vif_num) { 1098 error = EOPNOTSUPP; 1099 break; 1100 } 1101 if (m == NULL || m->m_len != sizeof(int)) { 1102 error = EINVAL; 1103 break; 1104 } 1105 i = *(mtod(m, int *)); 1106 if (!legal_vif_num(i) && (i != -1)) { 1107 error = EINVAL; 1108 break; 1109 } 1110 imo->imo_multicast_vif = i; 1111 break; 1112 1113 case IP_MULTICAST_IF: 1114 /* 1115 * Select the interface for outgoing multicast packets. 1116 */ 1117 if (m == NULL || m->m_len != sizeof(struct in_addr)) { 1118 error = EINVAL; 1119 break; 1120 } 1121 addr = *(mtod(m, struct in_addr *)); 1122 /* 1123 * INADDR_ANY is used to remove a previous selection. 1124 * When no interface is selected, a default one is 1125 * chosen every time a multicast packet is sent. 1126 */ 1127 if (addr.s_addr == INADDR_ANY) { 1128 imo->imo_multicast_ifp = NULL; 1129 break; 1130 } 1131 /* 1132 * The selected interface is identified by its local 1133 * IP address. Find the interface and confirm that 1134 * it supports multicasting. 1135 */ 1136 s = splimp(); 1137 INADDR_TO_IFP(addr, ifp); 1138 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1139 splx(s); 1140 error = EADDRNOTAVAIL; 1141 break; 1142 } 1143 imo->imo_multicast_ifp = ifp; 1144 splx(s); 1145 break; 1146 1147 case IP_MULTICAST_TTL: 1148 /* 1149 * Set the IP time-to-live for outgoing multicast packets. 1150 */ 1151 if (m == NULL || m->m_len != 1) { 1152 error = EINVAL; 1153 break; 1154 } 1155 imo->imo_multicast_ttl = *(mtod(m, u_char *)); 1156 break; 1157 1158 case IP_MULTICAST_LOOP: 1159 /* 1160 * Set the loopback flag for outgoing multicast packets. 1161 * Must be zero or one. 1162 */ 1163 if (m == NULL || m->m_len != 1 || 1164 (loop = *(mtod(m, u_char *))) > 1) { 1165 error = EINVAL; 1166 break; 1167 } 1168 imo->imo_multicast_loop = loop; 1169 break; 1170 1171 case IP_ADD_MEMBERSHIP: 1172 /* 1173 * Add a multicast group membership. 1174 * Group must be a valid IP multicast address. 1175 */ 1176 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1177 error = EINVAL; 1178 break; 1179 } 1180 mreq = mtod(m, struct ip_mreq *); 1181 if (!IN_MULTICAST(ntohl(mreq->imr_multiaddr.s_addr))) { 1182 error = EINVAL; 1183 break; 1184 } 1185 s = splimp(); 1186 /* 1187 * If no interface address was provided, use the interface of 1188 * the route to the given multicast address. 1189 */ 1190 if (mreq->imr_interface.s_addr == INADDR_ANY) { 1191 bzero((caddr_t)&ro, sizeof(ro)); 1192 dst = (struct sockaddr_in *)&ro.ro_dst; 1193 dst->sin_len = sizeof(*dst); 1194 dst->sin_family = AF_INET; 1195 dst->sin_addr = mreq->imr_multiaddr; 1196 rtalloc(&ro); 1197 if (ro.ro_rt == NULL) { 1198 error = EADDRNOTAVAIL; 1199 splx(s); 1200 break; 1201 } 1202 ifp = ro.ro_rt->rt_ifp; 1203 rtfree(ro.ro_rt); 1204 } 1205 else { 1206 INADDR_TO_IFP(mreq->imr_interface, ifp); 1207 } 1208 1209 /* 1210 * See if we found an interface, and confirm that it 1211 * supports multicast. 1212 */ 1213 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1214 error = EADDRNOTAVAIL; 1215 splx(s); 1216 break; 1217 } 1218 /* 1219 * See if the membership already exists or if all the 1220 * membership slots are full. 1221 */ 1222 for (i = 0; i < imo->imo_num_memberships; ++i) { 1223 if (imo->imo_membership[i]->inm_ifp == ifp && 1224 imo->imo_membership[i]->inm_addr.s_addr 1225 == mreq->imr_multiaddr.s_addr) 1226 break; 1227 } 1228 if (i < imo->imo_num_memberships) { 1229 error = EADDRINUSE; 1230 splx(s); 1231 break; 1232 } 1233 if (i == IP_MAX_MEMBERSHIPS) { 1234 error = ETOOMANYREFS; 1235 splx(s); 1236 break; 1237 } 1238 /* 1239 * Everything looks good; add a new record to the multicast 1240 * address list for the given interface. 1241 */ 1242 if ((imo->imo_membership[i] = 1243 in_addmulti(&mreq->imr_multiaddr, ifp)) == NULL) { 1244 error = ENOBUFS; 1245 splx(s); 1246 break; 1247 } 1248 ++imo->imo_num_memberships; 1249 splx(s); 1250 break; 1251 1252 case IP_DROP_MEMBERSHIP: 1253 /* 1254 * Drop a multicast group membership. 1255 * Group must be a valid IP multicast address. 1256 */ 1257 if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { 1258 error = EINVAL; 1259 break; 1260 } 1261 mreq = mtod(m, struct ip_mreq *); 1262 if (!IN_MULTICAST(ntohl(mreq->imr_multiaddr.s_addr))) { 1263 error = EINVAL; 1264 break; 1265 } 1266 1267 s = splimp(); 1268 /* 1269 * If an interface address was specified, get a pointer 1270 * to its ifnet structure. 1271 */ 1272 if (mreq->imr_interface.s_addr == INADDR_ANY) 1273 ifp = NULL; 1274 else { 1275 INADDR_TO_IFP(mreq->imr_interface, ifp); 1276 if (ifp == NULL) { 1277 error = EADDRNOTAVAIL; 1278 splx(s); 1279 break; 1280 } 1281 } 1282 /* 1283 * Find the membership in the membership array. 1284 */ 1285 for (i = 0; i < imo->imo_num_memberships; ++i) { 1286 if ((ifp == NULL || 1287 imo->imo_membership[i]->inm_ifp == ifp) && 1288 imo->imo_membership[i]->inm_addr.s_addr == 1289 mreq->imr_multiaddr.s_addr) 1290 break; 1291 } 1292 if (i == imo->imo_num_memberships) { 1293 error = EADDRNOTAVAIL; 1294 splx(s); 1295 break; 1296 } 1297 /* 1298 * Give up the multicast address record to which the 1299 * membership points. 1300 */ 1301 in_delmulti(imo->imo_membership[i]); 1302 /* 1303 * Remove the gap in the membership array. 1304 */ 1305 for (++i; i < imo->imo_num_memberships; ++i) 1306 imo->imo_membership[i-1] = imo->imo_membership[i]; 1307 --imo->imo_num_memberships; 1308 splx(s); 1309 break; 1310 1311 default: 1312 error = EOPNOTSUPP; 1313 break; 1314 } 1315 1316 /* 1317 * If all options have default values, no need to keep the mbuf. 1318 */ 1319 if (imo->imo_multicast_ifp == NULL && 1320 imo->imo_multicast_vif == -1 && 1321 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 1322 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 1323 imo->imo_num_memberships == 0) { 1324 free(*imop, M_IPMOPTS); 1325 *imop = NULL; 1326 } 1327 1328 return (error); 1329 } 1330 1331 /* 1332 * Return the IP multicast options in response to user getsockopt(). 1333 */ 1334 static int 1335 ip_getmoptions(optname, imo, mp) 1336 int optname; 1337 register struct ip_moptions *imo; 1338 register struct mbuf **mp; 1339 { 1340 u_char *ttl; 1341 u_char *loop; 1342 struct in_addr *addr; 1343 struct in_ifaddr *ia; 1344 1345 *mp = m_get(M_WAIT, MT_SOOPTS); 1346 1347 switch (optname) { 1348 1349 case IP_MULTICAST_VIF: 1350 if (imo != NULL) 1351 *(mtod(*mp, int *)) = imo->imo_multicast_vif; 1352 else 1353 *(mtod(*mp, int *)) = -1; 1354 (*mp)->m_len = sizeof(int); 1355 return(0); 1356 1357 case IP_MULTICAST_IF: 1358 addr = mtod(*mp, struct in_addr *); 1359 (*mp)->m_len = sizeof(struct in_addr); 1360 if (imo == NULL || imo->imo_multicast_ifp == NULL) 1361 addr->s_addr = INADDR_ANY; 1362 else { 1363 IFP_TO_IA(imo->imo_multicast_ifp, ia); 1364 addr->s_addr = (ia == NULL) ? INADDR_ANY 1365 : IA_SIN(ia)->sin_addr.s_addr; 1366 } 1367 return (0); 1368 1369 case IP_MULTICAST_TTL: 1370 ttl = mtod(*mp, u_char *); 1371 (*mp)->m_len = 1; 1372 *ttl = (imo == NULL) ? IP_DEFAULT_MULTICAST_TTL 1373 : imo->imo_multicast_ttl; 1374 return (0); 1375 1376 case IP_MULTICAST_LOOP: 1377 loop = mtod(*mp, u_char *); 1378 (*mp)->m_len = 1; 1379 *loop = (imo == NULL) ? IP_DEFAULT_MULTICAST_LOOP 1380 : imo->imo_multicast_loop; 1381 return (0); 1382 1383 default: 1384 return (EOPNOTSUPP); 1385 } 1386 } 1387 1388 /* 1389 * Discard the IP multicast options. 1390 */ 1391 void 1392 ip_freemoptions(imo) 1393 register struct ip_moptions *imo; 1394 { 1395 register int i; 1396 1397 if (imo != NULL) { 1398 for (i = 0; i < imo->imo_num_memberships; ++i) 1399 in_delmulti(imo->imo_membership[i]); 1400 free(imo, M_IPMOPTS); 1401 } 1402 } 1403 1404 /* 1405 * Routine called from ip_output() to loop back a copy of an IP multicast 1406 * packet to the input queue of a specified interface. Note that this 1407 * calls the output routine of the loopback "driver", but with an interface 1408 * pointer that might NOT be a loopback interface -- evil, but easier than 1409 * replicating that code here. 1410 */ 1411 static void 1412 ip_mloopback(ifp, m, dst, hlen) 1413 struct ifnet *ifp; 1414 register struct mbuf *m; 1415 register struct sockaddr_in *dst; 1416 int hlen; 1417 { 1418 register struct ip *ip; 1419 struct mbuf *copym; 1420 1421 copym = m_copy(m, 0, M_COPYALL); 1422 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen)) 1423 copym = m_pullup(copym, hlen); 1424 if (copym != NULL) { 1425 /* 1426 * We don't bother to fragment if the IP length is greater 1427 * than the interface's MTU. Can this possibly matter? 1428 */ 1429 ip = mtod(copym, struct ip *); 1430 ip->ip_len = htons((u_short)ip->ip_len); 1431 ip->ip_off = htons((u_short)ip->ip_off); 1432 ip->ip_sum = 0; 1433 if (ip->ip_vhl == IP_VHL_BORING) { 1434 ip->ip_sum = in_cksum_hdr(ip); 1435 } else { 1436 ip->ip_sum = in_cksum(copym, hlen); 1437 } 1438 /* 1439 * NB: 1440 * It's not clear whether there are any lingering 1441 * reentrancy problems in other areas which might 1442 * be exposed by using ip_input directly (in 1443 * particular, everything which modifies the packet 1444 * in-place). Yet another option is using the 1445 * protosw directly to deliver the looped back 1446 * packet. For the moment, we'll err on the side 1447 * of safety by using if_simloop(). 1448 */ 1449 #if 1 /* XXX */ 1450 if (dst->sin_family != AF_INET) { 1451 printf("ip_mloopback: bad address family %d\n", 1452 dst->sin_family); 1453 dst->sin_family = AF_INET; 1454 } 1455 #endif 1456 1457 #ifdef notdef 1458 copym->m_pkthdr.rcvif = ifp; 1459 ip_input(copym); 1460 #else 1461 if_simloop(ifp, copym, (struct sockaddr *)dst, 0); 1462 #endif 1463 } 1464 } 1465