Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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sys/netinet/ip_output.c
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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 * $FreeBSD$ 35 */ 36 37 #define _IP_VHL 38 39 #include "opt_ipfw.h" 40 #include "opt_ipdn.h" 41 #include "opt_ipdivert.h" 42 #include "opt_ipfilter.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/protosw.h> 50 #include <sys/socket.h> 51 #include <sys/socketvar.h> 52 53 #include <net/if.h> 54 #include <net/route.h> 55 56 #include <netinet/in.h> 57 #include <netinet/in_systm.h> 58 #include <netinet/ip.h> 59 #include <netinet/in_pcb.h> 60 #include <netinet/in_var.h> 61 #include <netinet/ip_var.h> 62 63 #ifdef vax 64 #include <machine/mtpr.h> 65 #endif 66 #include <machine/in_cksum.h> 67 68 static MALLOC_DEFINE(M_IPMOPTS, "ip_moptions", "internet multicast options"); 69 70 #if !defined(COMPAT_IPFW) || COMPAT_IPFW == 1 71 #undef COMPAT_IPFW 72 #define COMPAT_IPFW 1 73 #else 74 #undef COMPAT_IPFW 75 #endif 76 77 #ifdef COMPAT_IPFW 78 #include <netinet/ip_fw.h> 79 #endif 80 81 #ifdef DUMMYNET 82 #include <netinet/ip_dummynet.h> 83 #endif 84 85 #ifdef IPFIREWALL_FORWARD_DEBUG 86 #define print_ip(a) printf("%ld.%ld.%ld.%ld",(ntohl(a.s_addr)>>24)&0xFF,\ 87 (ntohl(a.s_addr)>>16)&0xFF,\ 88 (ntohl(a.s_addr)>>8)&0xFF,\ 89 (ntohl(a.s_addr))&0xFF); 90 #endif 91 92 u_short ip_id; 93 94 static struct mbuf *ip_insertoptions __P((struct mbuf *, struct mbuf *, int *)); 95 static void ip_mloopback 96 __P((struct ifnet *, struct mbuf *, struct sockaddr_in *, int)); 97 static int ip_getmoptions 98 __P((struct sockopt *, struct ip_moptions *)); 99 static int ip_pcbopts __P((int, struct mbuf **, struct mbuf *)); 100 static int ip_setmoptions 101 __P((struct sockopt *, struct ip_moptions **)); 102 103 #if defined(IPFILTER_LKM) || defined(IPFILTER) 104 int ip_optcopy __P((struct ip *, struct ip *)); 105 extern int (*fr_checkp) __P((struct ip *, int, struct ifnet *, int, struct mbuf **)); 106 #else 107 static int ip_optcopy __P((struct ip *, struct ip *)); 108 #endif 109 110 111 extern struct protosw inetsw[]; 112 113 /* 114 * IP output. The packet in mbuf chain m contains a skeletal IP 115 * header (with len, off, ttl, proto, tos, src, dst). 116 * The mbuf chain containing the packet will be freed. 117 * The mbuf opt, if present, will not be freed. 118 */ 119 int 120 ip_output(m0, opt, ro, flags, imo) 121 struct mbuf *m0; 122 struct mbuf *opt; 123 struct route *ro; 124 int flags; 125 struct ip_moptions *imo; 126 { 127 struct ip *ip, *mhip; 128 struct ifnet *ifp; 129 struct mbuf *m = m0; 130 int hlen = sizeof (struct ip); 131 int len, off, error = 0; 132 struct sockaddr_in *dst; 133 struct in_ifaddr *ia; 134 int isbroadcast; 135 #ifdef IPFIREWALL_FORWARD 136 int fwd_rewrite_src = 0; 137 #endif 138 139 #ifndef IPDIVERT /* dummy variable for the firewall code to play with */ 140 u_short ip_divert_cookie = 0 ; 141 #endif 142 #ifdef COMPAT_IPFW 143 struct ip_fw_chain *rule = NULL ; 144 #endif 145 146 #if defined(IPFIREWALL) && defined(DUMMYNET) 147 /* 148 * dummynet packet are prepended a vestigial mbuf with 149 * m_type = MT_DUMMYNET and m_data pointing to the matching 150 * rule. 151 */ 152 if (m->m_type == MT_DUMMYNET) { 153 /* 154 * the packet was already tagged, so part of the 155 * processing was already done, and we need to go down. 156 * Get parameters from the header. 157 */ 158 rule = (struct ip_fw_chain *)(m->m_data) ; 159 opt = NULL ; 160 ro = & ( ((struct dn_pkt *)m)->ro ) ; 161 flags = 0 ; /* XXX is this correct ? */ 162 imo = NULL ; 163 dst = ((struct dn_pkt *)m)->dn_dst ; 164 ifp = ((struct dn_pkt *)m)->ifp ; 165 166 m0 = m = m->m_next ; 167 ip = mtod(m, struct ip *); 168 hlen = IP_VHL_HL(ip->ip_vhl) << 2 ; 169 goto sendit; 170 } else 171 rule = NULL ; 172 #endif 173 174 #ifdef DIAGNOSTIC 175 if ((m->m_flags & M_PKTHDR) == 0) 176 panic("ip_output no HDR"); 177 if (!ro) 178 panic("ip_output no route, proto = %d", 179 mtod(m, struct ip *)->ip_p); 180 #endif 181 if (opt) { 182 m = ip_insertoptions(m, opt, &len); 183 hlen = len; 184 } 185 ip = mtod(m, struct ip *); 186 /* 187 * Fill in IP header. 188 */ 189 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { 190 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, hlen >> 2); 191 ip->ip_off &= IP_DF; 192 ip->ip_id = htons(ip_id++); 193 ipstat.ips_localout++; 194 } else { 195 hlen = IP_VHL_HL(ip->ip_vhl) << 2; 196 } 197 198 dst = (struct sockaddr_in *)&ro->ro_dst; 199 /* 200 * If there is a cached route, 201 * check that it is to the same destination 202 * and is still up. If not, free it and try again. 203 */ 204 if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 || 205 dst->sin_addr.s_addr != ip->ip_dst.s_addr)) { 206 RTFREE(ro->ro_rt); 207 ro->ro_rt = (struct rtentry *)0; 208 } 209 if (ro->ro_rt == 0) { 210 dst->sin_family = AF_INET; 211 dst->sin_len = sizeof(*dst); 212 dst->sin_addr = ip->ip_dst; 213 } 214 /* 215 * If routing to interface only, 216 * short circuit routing lookup. 217 */ 218 #define ifatoia(ifa) ((struct in_ifaddr *)(ifa)) 219 #define sintosa(sin) ((struct sockaddr *)(sin)) 220 if (flags & IP_ROUTETOIF) { 221 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == 0 && 222 (ia = ifatoia(ifa_ifwithnet(sintosa(dst)))) == 0) { 223 ipstat.ips_noroute++; 224 error = ENETUNREACH; 225 goto bad; 226 } 227 ifp = ia->ia_ifp; 228 ip->ip_ttl = 1; 229 isbroadcast = in_broadcast(dst->sin_addr, ifp); 230 } else { 231 /* 232 * If this is the case, we probably don't want to allocate 233 * a protocol-cloned route since we didn't get one from the 234 * ULP. This lets TCP do its thing, while not burdening 235 * forwarding or ICMP with the overhead of cloning a route. 236 * Of course, we still want to do any cloning requested by 237 * the link layer, as this is probably required in all cases 238 * for correct operation (as it is for ARP). 239 */ 240 if (ro->ro_rt == 0) 241 rtalloc_ign(ro, RTF_PRCLONING); 242 if (ro->ro_rt == 0) { 243 ipstat.ips_noroute++; 244 error = EHOSTUNREACH; 245 goto bad; 246 } 247 ia = ifatoia(ro->ro_rt->rt_ifa); 248 ifp = ro->ro_rt->rt_ifp; 249 ro->ro_rt->rt_use++; 250 if (ro->ro_rt->rt_flags & RTF_GATEWAY) 251 dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway; 252 if (ro->ro_rt->rt_flags & RTF_HOST) 253 isbroadcast = (ro->ro_rt->rt_flags & RTF_BROADCAST); 254 else 255 isbroadcast = in_broadcast(dst->sin_addr, ifp); 256 } 257 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) { 258 struct in_multi *inm; 259 260 m->m_flags |= M_MCAST; 261 /* 262 * IP destination address is multicast. Make sure "dst" 263 * still points to the address in "ro". (It may have been 264 * changed to point to a gateway address, above.) 265 */ 266 dst = (struct sockaddr_in *)&ro->ro_dst; 267 /* 268 * See if the caller provided any multicast options 269 */ 270 if (imo != NULL) { 271 ip->ip_ttl = imo->imo_multicast_ttl; 272 if (imo->imo_multicast_ifp != NULL) 273 ifp = imo->imo_multicast_ifp; 274 if (imo->imo_multicast_vif != -1) 275 ip->ip_src.s_addr = 276 ip_mcast_src(imo->imo_multicast_vif); 277 } else 278 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; 279 /* 280 * Confirm that the outgoing interface supports multicast. 281 */ 282 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) { 283 if ((ifp->if_flags & IFF_MULTICAST) == 0) { 284 ipstat.ips_noroute++; 285 error = ENETUNREACH; 286 goto bad; 287 } 288 } 289 /* 290 * If source address not specified yet, use address 291 * of outgoing interface. 292 */ 293 if (ip->ip_src.s_addr == INADDR_ANY) { 294 register struct in_ifaddr *ia1; 295 296 for (ia1 = in_ifaddrhead.tqh_first; ia1; 297 ia1 = ia1->ia_link.tqe_next) 298 if (ia1->ia_ifp == ifp) { 299 ip->ip_src = IA_SIN(ia1)->sin_addr; 300 break; 301 } 302 } 303 304 IN_LOOKUP_MULTI(ip->ip_dst, ifp, inm); 305 if (inm != NULL && 306 (imo == NULL || imo->imo_multicast_loop)) { 307 /* 308 * If we belong to the destination multicast group 309 * on the outgoing interface, and the caller did not 310 * forbid loopback, loop back a copy. 311 */ 312 ip_mloopback(ifp, m, dst, hlen); 313 } 314 else { 315 /* 316 * If we are acting as a multicast router, perform 317 * multicast forwarding as if the packet had just 318 * arrived on the interface to which we are about 319 * to send. The multicast forwarding function 320 * recursively calls this function, using the 321 * IP_FORWARDING flag to prevent infinite recursion. 322 * 323 * Multicasts that are looped back by ip_mloopback(), 324 * above, will be forwarded by the ip_input() routine, 325 * if necessary. 326 */ 327 if (ip_mrouter && (flags & IP_FORWARDING) == 0) { 328 /* 329 * Check if rsvp daemon is running. If not, don't 330 * set ip_moptions. This ensures that the packet 331 * is multicast and not just sent down one link 332 * as prescribed by rsvpd. 333 */ 334 if (!rsvp_on) 335 imo = NULL; 336 if (ip_mforward(ip, ifp, m, imo) != 0) { 337 m_freem(m); 338 goto done; 339 } 340 } 341 } 342 343 /* 344 * Multicasts with a time-to-live of zero may be looped- 345 * back, above, but must not be transmitted on a network. 346 * Also, multicasts addressed to the loopback interface 347 * are not sent -- the above call to ip_mloopback() will 348 * loop back a copy if this host actually belongs to the 349 * destination group on the loopback interface. 350 */ 351 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) { 352 m_freem(m); 353 goto done; 354 } 355 356 goto sendit; 357 } 358 #ifndef notdef 359 /* 360 * If source address not specified yet, use address 361 * of outgoing interface. 362 */ 363 if (ip->ip_src.s_addr == INADDR_ANY) { 364 ip->ip_src = IA_SIN(ia)->sin_addr; 365 #ifdef IPFIREWALL_FORWARD 366 /* Keep note that we did this - if the firewall changes 367 * the next-hop, our interface may change, changing the 368 * default source IP. It's a shame so much effort happens 369 * twice. Oh well. 370 */ 371 fwd_rewrite_src++; 372 #endif /* IPFIREWALL_FORWARD */ 373 } 374 #endif /* notdef */ 375 /* 376 * Verify that we have any chance at all of being able to queue 377 * the packet or packet fragments 378 */ 379 if ((ifp->if_snd.ifq_len + ip->ip_len / ifp->if_mtu + 1) >= 380 ifp->if_snd.ifq_maxlen) { 381 error = ENOBUFS; 382 goto bad; 383 } 384 385 /* 386 * Look for broadcast address and 387 * and verify user is allowed to send 388 * such a packet. 389 */ 390 if (isbroadcast) { 391 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 392 error = EADDRNOTAVAIL; 393 goto bad; 394 } 395 if ((flags & IP_ALLOWBROADCAST) == 0) { 396 error = EACCES; 397 goto bad; 398 } 399 /* don't allow broadcast messages to be fragmented */ 400 if ((u_short)ip->ip_len > ifp->if_mtu) { 401 error = EMSGSIZE; 402 goto bad; 403 } 404 m->m_flags |= M_BCAST; 405 } else { 406 m->m_flags &= ~M_BCAST; 407 } 408 409 sendit: 410 /* 411 * IpHack's section. 412 * - Xlate: translate packet's addr/port (NAT). 413 * - Firewall: deny/allow/etc. 414 * - Wrap: fake packet's addr/port <unimpl.> 415 * - Encapsulate: put it in another IP and send out. <unimp.> 416 */ 417 #if defined(IPFILTER) || defined(IPFILTER_LKM) 418 if (fr_checkp) { 419 struct mbuf *m1 = m; 420 421 if ((error = (*fr_checkp)(ip, hlen, ifp, 1, &m1)) || !m1) 422 goto done; 423 ip = mtod(m = m1, struct ip *); 424 } 425 #endif 426 427 #ifdef COMPAT_IPFW 428 /* 429 * Check with the firewall... 430 */ 431 if (fw_enable && ip_fw_chk_ptr) { 432 struct sockaddr_in *old = dst; 433 434 off = (*ip_fw_chk_ptr)(&ip, 435 hlen, ifp, &ip_divert_cookie, &m, &rule, &dst); 436 /* 437 * On return we must do the following: 438 * m == NULL -> drop the pkt 439 * 1<=off<= 0xffff -> DIVERT 440 * (off & 0x10000) -> send to a DUMMYNET pipe 441 * dst != old -> IPFIREWALL_FORWARD 442 * off==0, dst==old -> accept 443 * If some of the above modules is not compiled in, then 444 * we should't have to check the corresponding condition 445 * (because the ipfw control socket should not accept 446 * unsupported rules), but better play safe and drop 447 * packets in case of doubt. 448 */ 449 if (!m) { /* firewall said to reject */ 450 error = EACCES; 451 goto done; 452 } 453 if (off == 0 && dst == old) /* common case */ 454 goto pass ; 455 #ifdef DUMMYNET 456 if (off & 0x10000) { 457 /* 458 * pass the pkt to dummynet. Need to include 459 * pipe number, m, ifp, ro, dst because these are 460 * not recomputed in the next pass. 461 * All other parameters have been already used and 462 * so they are not needed anymore. 463 * XXX note: if the ifp or ro entry are deleted 464 * while a pkt is in dummynet, we are in trouble! 465 */ 466 dummynet_io(off & 0xffff, DN_TO_IP_OUT, m,ifp,ro,dst,rule); 467 goto done; 468 } 469 #endif 470 #ifdef IPDIVERT 471 if (off > 0 && off < 0x10000) { /* Divert packet */ 472 ip_divert_port = off & 0xffff ; 473 (*inetsw[ip_protox[IPPROTO_DIVERT]].pr_input)(m, 0); 474 goto done; 475 } 476 #endif 477 478 #ifdef IPFIREWALL_FORWARD 479 /* Here we check dst to make sure it's directly reachable on the 480 * interface we previously thought it was. 481 * If it isn't (which may be likely in some situations) we have 482 * to re-route it (ie, find a route for the next-hop and the 483 * associated interface) and set them here. This is nested 484 * forwarding which in most cases is undesirable, except where 485 * such control is nigh impossible. So we do it here. 486 * And I'm babbling. 487 */ 488 if (off == 0 && old != dst) { 489 struct in_ifaddr *ia; 490 491 /* It's changed... */ 492 /* There must be a better way to do this next line... */ 493 static struct route sro_fwd, *ro_fwd = &sro_fwd; 494 #ifdef IPFIREWALL_FORWARD_DEBUG 495 printf("IPFIREWALL_FORWARD: New dst ip: "); 496 print_ip(dst->sin_addr); 497 printf("\n"); 498 #endif 499 /* 500 * We need to figure out if we have been forwarded 501 * to a local socket. If so then we should somehow 502 * "loop back" to ip_input, and get directed to the 503 * PCB as if we had received this packet. This is 504 * because it may be dificult to identify the packets 505 * you want to forward until they are being output 506 * and have selected an interface. (e.g. locally 507 * initiated packets) If we used the loopback inteface, 508 * we would not be able to control what happens 509 * as the packet runs through ip_input() as 510 * it is done through a ISR. 511 */ 512 for (ia = TAILQ_FIRST(&in_ifaddrhead); ia; 513 ia = TAILQ_NEXT(ia, ia_link)) { 514 /* 515 * If the addr to forward to is one 516 * of ours, we pretend to 517 * be the destination for this packet. 518 */ 519 if (IA_SIN(ia)->sin_addr.s_addr == 520 dst->sin_addr.s_addr) 521 break; 522 } 523 if (ia) { 524 /* tell ip_input "dont filter" */ 525 ip_fw_fwd_addr = dst; 526 if (m->m_pkthdr.rcvif == NULL) 527 m->m_pkthdr.rcvif = ifunit("lo0"); 528 ip->ip_len = htons((u_short)ip->ip_len); 529 ip->ip_off = htons((u_short)ip->ip_off); 530 ip->ip_sum = 0; 531 if (ip->ip_vhl == IP_VHL_BORING) { 532 ip->ip_sum = in_cksum_hdr(ip); 533 } else { 534 ip->ip_sum = in_cksum(m, hlen); 535 } 536 ip_input(m); 537 goto done; 538 } 539 /* Some of the logic for this was 540 * nicked from above. 541 * 542 * This rewrites the cached route in a local PCB. 543 * Is this what we want to do? 544 */ 545 bcopy(dst, &ro_fwd->ro_dst, sizeof(*dst)); 546 547 ro_fwd->ro_rt = 0; 548 rtalloc_ign(ro_fwd, RTF_PRCLONING); 549 550 if (ro_fwd->ro_rt == 0) { 551 ipstat.ips_noroute++; 552 error = EHOSTUNREACH; 553 goto bad; 554 } 555 556 ia = ifatoia(ro_fwd->ro_rt->rt_ifa); 557 ifp = ro_fwd->ro_rt->rt_ifp; 558 ro_fwd->ro_rt->rt_use++; 559 if (ro_fwd->ro_rt->rt_flags & RTF_GATEWAY) 560 dst = (struct sockaddr_in *)ro_fwd->ro_rt->rt_gateway; 561 if (ro_fwd->ro_rt->rt_flags & RTF_HOST) 562 isbroadcast = 563 (ro_fwd->ro_rt->rt_flags & RTF_BROADCAST); 564 else 565 isbroadcast = in_broadcast(dst->sin_addr, ifp); 566 RTFREE(ro->ro_rt); 567 ro->ro_rt = ro_fwd->ro_rt; 568 dst = (struct sockaddr_in *)&ro_fwd->ro_dst; 569 570 /* 571 * If we added a default src ip earlier, 572 * which would have been gotten from the-then 573 * interface, do it again, from the new one. 574 */ 575 if (fwd_rewrite_src) 576 ip->ip_src = IA_SIN(ia)->sin_addr; 577 goto pass ; 578 } 579 #endif /* IPFIREWALL_FORWARD */ 580 /* 581 * if we get here, none of the above matches, and 582 * we have to drop the pkt 583 */ 584 m_freem(m); 585 error = EACCES; /* not sure this is the right error msg */ 586 goto done; 587 } 588 #endif /* COMPAT_IPFW */ 589 590 pass: 591 /* 592 * If small enough for interface, can just send directly. 593 */ 594 if ((u_short)ip->ip_len <= ifp->if_mtu) { 595 ip->ip_len = htons((u_short)ip->ip_len); 596 ip->ip_off = htons((u_short)ip->ip_off); 597 ip->ip_sum = 0; 598 if (ip->ip_vhl == IP_VHL_BORING) { 599 ip->ip_sum = in_cksum_hdr(ip); 600 } else { 601 ip->ip_sum = in_cksum(m, hlen); 602 } 603 error = (*ifp->if_output)(ifp, m, 604 (struct sockaddr *)dst, ro->ro_rt); 605 goto done; 606 } 607 /* 608 * Too large for interface; fragment if possible. 609 * Must be able to put at least 8 bytes per fragment. 610 */ 611 if (ip->ip_off & IP_DF) { 612 error = EMSGSIZE; 613 /* 614 * This case can happen if the user changed the MTU 615 * of an interface after enabling IP on it. Because 616 * most netifs don't keep track of routes pointing to 617 * them, there is no way for one to update all its 618 * routes when the MTU is changed. 619 */ 620 if ((ro->ro_rt->rt_flags & (RTF_UP | RTF_HOST)) 621 && !(ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) 622 && (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)) { 623 ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu; 624 } 625 ipstat.ips_cantfrag++; 626 goto bad; 627 } 628 len = (ifp->if_mtu - hlen) &~ 7; 629 if (len < 8) { 630 error = EMSGSIZE; 631 goto bad; 632 } 633 634 { 635 int mhlen, firstlen = len; 636 struct mbuf **mnext = &m->m_nextpkt; 637 638 /* 639 * Loop through length of segment after first fragment, 640 * make new header and copy data of each part and link onto chain. 641 */ 642 m0 = m; 643 mhlen = sizeof (struct ip); 644 for (off = hlen + len; off < (u_short)ip->ip_len; off += len) { 645 MGETHDR(m, M_DONTWAIT, MT_HEADER); 646 if (m == 0) { 647 error = ENOBUFS; 648 ipstat.ips_odropped++; 649 goto sendorfree; 650 } 651 m->m_flags |= (m0->m_flags & M_MCAST); 652 m->m_data += max_linkhdr; 653 mhip = mtod(m, struct ip *); 654 *mhip = *ip; 655 if (hlen > sizeof (struct ip)) { 656 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); 657 mhip->ip_vhl = IP_MAKE_VHL(IPVERSION, mhlen >> 2); 658 } 659 m->m_len = mhlen; 660 mhip->ip_off = ((off - hlen) >> 3) + (ip->ip_off & ~IP_MF); 661 if (ip->ip_off & IP_MF) 662 mhip->ip_off |= IP_MF; 663 if (off + len >= (u_short)ip->ip_len) 664 len = (u_short)ip->ip_len - off; 665 else 666 mhip->ip_off |= IP_MF; 667 mhip->ip_len = htons((u_short)(len + mhlen)); 668 m->m_next = m_copy(m0, off, len); 669 if (m->m_next == 0) { 670 (void) m_free(m); 671 error = ENOBUFS; /* ??? */ 672 ipstat.ips_odropped++; 673 goto sendorfree; 674 } 675 m->m_pkthdr.len = mhlen + len; 676 m->m_pkthdr.rcvif = (struct ifnet *)0; 677 mhip->ip_off = htons((u_short)mhip->ip_off); 678 mhip->ip_sum = 0; 679 if (mhip->ip_vhl == IP_VHL_BORING) { 680 mhip->ip_sum = in_cksum_hdr(mhip); 681 } else { 682 mhip->ip_sum = in_cksum(m, mhlen); 683 } 684 *mnext = m; 685 mnext = &m->m_nextpkt; 686 ipstat.ips_ofragments++; 687 } 688 /* 689 * Update first fragment by trimming what's been copied out 690 * and updating header, then send each fragment (in order). 691 */ 692 m = m0; 693 m_adj(m, hlen + firstlen - (u_short)ip->ip_len); 694 m->m_pkthdr.len = hlen + firstlen; 695 ip->ip_len = htons((u_short)m->m_pkthdr.len); 696 ip->ip_off = htons((u_short)(ip->ip_off | IP_MF)); 697 ip->ip_sum = 0; 698 if (ip->ip_vhl == IP_VHL_BORING) { 699 ip->ip_sum = in_cksum_hdr(ip); 700 } else { 701 ip->ip_sum = in_cksum(m, hlen); 702 } 703 sendorfree: 704 for (m = m0; m; m = m0) { 705 m0 = m->m_nextpkt; 706 m->m_nextpkt = 0; 707 if (error == 0) 708 error = (*ifp->if_output)(ifp, m, 709 (struct sockaddr *)dst, ro->ro_rt); 710 else 711 m_freem(m); 712 } 713 714 if (error == 0) 715 ipstat.ips_fragmented++; 716 } 717 done: 718 return (error); 719 bad: 720 m_freem(m0); 721 goto done; 722 } 723 724 /* 725 * Insert IP options into preformed packet. 726 * Adjust IP destination as required for IP source routing, 727 * as indicated by a non-zero in_addr at the start of the options. 728 * 729 * XXX This routine assumes that the packet has no options in place. 730 */ 731 static struct mbuf * 732 ip_insertoptions(m, opt, phlen) 733 register struct mbuf *m; 734 struct mbuf *opt; 735 int *phlen; 736 { 737 register struct ipoption *p = mtod(opt, struct ipoption *); 738 struct mbuf *n; 739 register struct ip *ip = mtod(m, struct ip *); 740 unsigned optlen; 741 742 optlen = opt->m_len - sizeof(p->ipopt_dst); 743 if (optlen + (u_short)ip->ip_len > IP_MAXPACKET) 744 return (m); /* XXX should fail */ 745 if (p->ipopt_dst.s_addr) 746 ip->ip_dst = p->ipopt_dst; 747 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { 748 MGETHDR(n, M_DONTWAIT, MT_HEADER); 749 if (n == 0) 750 return (m); 751 n->m_pkthdr.rcvif = (struct ifnet *)0; 752 n->m_pkthdr.len = m->m_pkthdr.len + optlen; 753 m->m_len -= sizeof(struct ip); 754 m->m_data += sizeof(struct ip); 755 n->m_next = m; 756 m = n; 757 m->m_len = optlen + sizeof(struct ip); 758 m->m_data += max_linkhdr; 759 (void)memcpy(mtod(m, void *), ip, sizeof(struct ip)); 760 } else { 761 m->m_data -= optlen; 762 m->m_len += optlen; 763 m->m_pkthdr.len += optlen; 764 ovbcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 765 } 766 ip = mtod(m, struct ip *); 767 bcopy(p->ipopt_list, ip + 1, optlen); 768 *phlen = sizeof(struct ip) + optlen; 769 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, *phlen >> 2); 770 ip->ip_len += optlen; 771 return (m); 772 } 773 774 /* 775 * Copy options from ip to jp, 776 * omitting those not copied during fragmentation. 777 */ 778 #if !defined(IPFILTER) && !defined(IPFILTER_LKM) 779 static 780 #endif 781 int 782 ip_optcopy(ip, jp) 783 struct ip *ip, *jp; 784 { 785 register u_char *cp, *dp; 786 int opt, optlen, cnt; 787 788 cp = (u_char *)(ip + 1); 789 dp = (u_char *)(jp + 1); 790 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof (struct ip); 791 for (; cnt > 0; cnt -= optlen, cp += optlen) { 792 opt = cp[0]; 793 if (opt == IPOPT_EOL) 794 break; 795 if (opt == IPOPT_NOP) { 796 /* Preserve for IP mcast tunnel's LSRR alignment. */ 797 *dp++ = IPOPT_NOP; 798 optlen = 1; 799 continue; 800 } else 801 optlen = cp[IPOPT_OLEN]; 802 /* bogus lengths should have been caught by ip_dooptions */ 803 if (optlen > cnt) 804 optlen = cnt; 805 if (IPOPT_COPIED(opt)) { 806 bcopy(cp, dp, optlen); 807 dp += optlen; 808 } 809 } 810 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 811 *dp++ = IPOPT_EOL; 812 return (optlen); 813 } 814 815 /* 816 * IP socket option processing. 817 */ 818 int 819 ip_ctloutput(so, sopt) 820 struct socket *so; 821 struct sockopt *sopt; 822 { 823 struct inpcb *inp = sotoinpcb(so); 824 int error, optval; 825 826 error = optval = 0; 827 if (sopt->sopt_level != IPPROTO_IP) { 828 return (EINVAL); 829 } 830 831 switch (sopt->sopt_dir) { 832 case SOPT_SET: 833 switch (sopt->sopt_name) { 834 case IP_OPTIONS: 835 #ifdef notyet 836 case IP_RETOPTS: 837 #endif 838 { 839 struct mbuf *m; 840 if (sopt->sopt_valsize > MLEN) { 841 error = EMSGSIZE; 842 break; 843 } 844 MGET(m, sopt->sopt_p ? M_WAIT : M_DONTWAIT, MT_HEADER); 845 if (m == 0) { 846 error = ENOBUFS; 847 break; 848 } 849 m->m_len = sopt->sopt_valsize; 850 error = sooptcopyin(sopt, mtod(m, char *), m->m_len, 851 m->m_len); 852 853 return (ip_pcbopts(sopt->sopt_name, &inp->inp_options, 854 m)); 855 } 856 857 case IP_TOS: 858 case IP_TTL: 859 case IP_RECVOPTS: 860 case IP_RECVRETOPTS: 861 case IP_RECVDSTADDR: 862 case IP_RECVIF: 863 error = sooptcopyin(sopt, &optval, sizeof optval, 864 sizeof optval); 865 if (error) 866 break; 867 868 switch (sopt->sopt_name) { 869 case IP_TOS: 870 inp->inp_ip_tos = optval; 871 break; 872 873 case IP_TTL: 874 inp->inp_ip_ttl = optval; 875 break; 876 #define OPTSET(bit) \ 877 if (optval) \ 878 inp->inp_flags |= bit; \ 879 else \ 880 inp->inp_flags &= ~bit; 881 882 case IP_RECVOPTS: 883 OPTSET(INP_RECVOPTS); 884 break; 885 886 case IP_RECVRETOPTS: 887 OPTSET(INP_RECVRETOPTS); 888 break; 889 890 case IP_RECVDSTADDR: 891 OPTSET(INP_RECVDSTADDR); 892 break; 893 894 case IP_RECVIF: 895 OPTSET(INP_RECVIF); 896 break; 897 } 898 break; 899 #undef OPTSET 900 901 case IP_MULTICAST_IF: 902 case IP_MULTICAST_VIF: 903 case IP_MULTICAST_TTL: 904 case IP_MULTICAST_LOOP: 905 case IP_ADD_MEMBERSHIP: 906 case IP_DROP_MEMBERSHIP: 907 error = ip_setmoptions(sopt, &inp->inp_moptions); 908 break; 909 910 case IP_PORTRANGE: 911 error = sooptcopyin(sopt, &optval, sizeof optval, 912 sizeof optval); 913 if (error) 914 break; 915 916 switch (optval) { 917 case IP_PORTRANGE_DEFAULT: 918 inp->inp_flags &= ~(INP_LOWPORT); 919 inp->inp_flags &= ~(INP_HIGHPORT); 920 break; 921 922 case IP_PORTRANGE_HIGH: 923 inp->inp_flags &= ~(INP_LOWPORT); 924 inp->inp_flags |= INP_HIGHPORT; 925 break; 926 927 case IP_PORTRANGE_LOW: 928 inp->inp_flags &= ~(INP_HIGHPORT); 929 inp->inp_flags |= INP_LOWPORT; 930 break; 931 932 default: 933 error = EINVAL; 934 break; 935 } 936 break; 937 938 default: 939 error = ENOPROTOOPT; 940 break; 941 } 942 break; 943 944 case SOPT_GET: 945 switch (sopt->sopt_name) { 946 case IP_OPTIONS: 947 case IP_RETOPTS: 948 if (inp->inp_options) 949 error = sooptcopyout(sopt, 950 mtod(inp->inp_options, 951 char *), 952 inp->inp_options->m_len); 953 else 954 sopt->sopt_valsize = 0; 955 break; 956 957 case IP_TOS: 958 case IP_TTL: 959 case IP_RECVOPTS: 960 case IP_RECVRETOPTS: 961 case IP_RECVDSTADDR: 962 case IP_RECVIF: 963 case IP_PORTRANGE: 964 switch (sopt->sopt_name) { 965 966 case IP_TOS: 967 optval = inp->inp_ip_tos; 968 break; 969 970 case IP_TTL: 971 optval = inp->inp_ip_ttl; 972 break; 973 974 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) 975 976 case IP_RECVOPTS: 977 optval = OPTBIT(INP_RECVOPTS); 978 break; 979 980 case IP_RECVRETOPTS: 981 optval = OPTBIT(INP_RECVRETOPTS); 982 break; 983 984 case IP_RECVDSTADDR: 985 optval = OPTBIT(INP_RECVDSTADDR); 986 break; 987 988 case IP_RECVIF: 989 optval = OPTBIT(INP_RECVIF); 990 break; 991 992 case IP_PORTRANGE: 993 if (inp->inp_flags & INP_HIGHPORT) 994 optval = IP_PORTRANGE_HIGH; 995 else if (inp->inp_flags & INP_LOWPORT) 996 optval = IP_PORTRANGE_LOW; 997 else 998 optval = 0; 999 break; 1000 } 1001 error = sooptcopyout(sopt, &optval, sizeof optval); 1002 break; 1003 1004 case IP_MULTICAST_IF: 1005 case IP_MULTICAST_VIF: 1006 case IP_MULTICAST_TTL: 1007 case IP_MULTICAST_LOOP: 1008 case IP_ADD_MEMBERSHIP: 1009 case IP_DROP_MEMBERSHIP: 1010 error = ip_getmoptions(sopt, inp->inp_moptions); 1011 break; 1012 1013 default: 1014 error = ENOPROTOOPT; 1015 break; 1016 } 1017 break; 1018 } 1019 return (error); 1020 } 1021 1022 /* 1023 * Set up IP options in pcb for insertion in output packets. 1024 * Store in mbuf with pointer in pcbopt, adding pseudo-option 1025 * with destination address if source routed. 1026 */ 1027 static int 1028 ip_pcbopts(optname, pcbopt, m) 1029 int optname; 1030 struct mbuf **pcbopt; 1031 register struct mbuf *m; 1032 { 1033 register int cnt, optlen; 1034 register u_char *cp; 1035 u_char opt; 1036 1037 /* turn off any old options */ 1038 if (*pcbopt) 1039 (void)m_free(*pcbopt); 1040 *pcbopt = 0; 1041 if (m == (struct mbuf *)0 || m->m_len == 0) { 1042 /* 1043 * Only turning off any previous options. 1044 */ 1045 if (m) 1046 (void)m_free(m); 1047 return (0); 1048 } 1049 1050 #ifndef vax 1051 if (m->m_len % sizeof(int32_t)) 1052 goto bad; 1053 #endif 1054 /* 1055 * IP first-hop destination address will be stored before 1056 * actual options; move other options back 1057 * and clear it when none present. 1058 */ 1059 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) 1060 goto bad; 1061 cnt = m->m_len; 1062 m->m_len += sizeof(struct in_addr); 1063 cp = mtod(m, u_char *) + sizeof(struct in_addr); 1064 ovbcopy(mtod(m, caddr_t), (caddr_t)cp, (unsigned)cnt); 1065 bzero(mtod(m, caddr_t), sizeof(struct in_addr)); 1066 1067 for (; cnt > 0; cnt -= optlen, cp += optlen) { 1068 opt = cp[IPOPT_OPTVAL]; 1069 if (opt == IPOPT_EOL) 1070 break; 1071 if (opt == IPOPT_NOP) 1072 optlen = 1; 1073 else { 1074 if (cnt < IPOPT_OLEN + sizeof(*cp)) 1075 goto bad; 1076 optlen = cp[IPOPT_OLEN]; 1077 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) 1078 goto bad; 1079 } 1080 switch (opt) { 1081 1082 default: 1083 break; 1084 1085 case IPOPT_LSRR: 1086 case IPOPT_SSRR: 1087 /* 1088 * user process specifies route as: 1089 * ->A->B->C->D 1090 * D must be our final destination (but we can't 1091 * check that since we may not have connected yet). 1092 * A is first hop destination, which doesn't appear in 1093 * actual IP option, but is stored before the options. 1094 */ 1095 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) 1096 goto bad; 1097 m->m_len -= sizeof(struct in_addr); 1098 cnt -= sizeof(struct in_addr); 1099 optlen -= sizeof(struct in_addr); 1100 cp[IPOPT_OLEN] = optlen; 1101 /* 1102 * Move first hop before start of options. 1103 */ 1104 bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), 1105 sizeof(struct in_addr)); 1106 /* 1107 * Then copy rest of options back 1108 * to close up the deleted entry. 1109 */ 1110 ovbcopy((caddr_t)(&cp[IPOPT_OFFSET+1] + 1111 sizeof(struct in_addr)), 1112 (caddr_t)&cp[IPOPT_OFFSET+1], 1113 (unsigned)cnt + sizeof(struct in_addr)); 1114 break; 1115 } 1116 } 1117 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) 1118 goto bad; 1119 *pcbopt = m; 1120 return (0); 1121 1122 bad: 1123 (void)m_free(m); 1124 return (EINVAL); 1125 } 1126 1127 /* 1128 * XXX 1129 * The whole multicast option thing needs to be re-thought. 1130 * Several of these options are equally applicable to non-multicast 1131 * transmission, and one (IP_MULTICAST_TTL) totally duplicates a 1132 * standard option (IP_TTL). 1133 */ 1134 /* 1135 * Set the IP multicast options in response to user setsockopt(). 1136 */ 1137 static int 1138 ip_setmoptions(sopt, imop) 1139 struct sockopt *sopt; 1140 struct ip_moptions **imop; 1141 { 1142 int error = 0; 1143 int i; 1144 struct in_addr addr; 1145 struct ip_mreq mreq; 1146 struct ifnet *ifp; 1147 struct ip_moptions *imo = *imop; 1148 struct route ro; 1149 struct sockaddr_in *dst; 1150 int s; 1151 1152 if (imo == NULL) { 1153 /* 1154 * No multicast option buffer attached to the pcb; 1155 * allocate one and initialize to default values. 1156 */ 1157 imo = (struct ip_moptions*)malloc(sizeof(*imo), M_IPMOPTS, 1158 M_WAITOK); 1159 1160 if (imo == NULL) 1161 return (ENOBUFS); 1162 *imop = imo; 1163 imo->imo_multicast_ifp = NULL; 1164 imo->imo_multicast_vif = -1; 1165 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; 1166 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; 1167 imo->imo_num_memberships = 0; 1168 } 1169 1170 switch (sopt->sopt_name) { 1171 /* store an index number for the vif you wanna use in the send */ 1172 case IP_MULTICAST_VIF: 1173 if (legal_vif_num == 0) { 1174 error = EOPNOTSUPP; 1175 break; 1176 } 1177 error = sooptcopyin(sopt, &i, sizeof i, sizeof i); 1178 if (error) 1179 break; 1180 if (!legal_vif_num(i) && (i != -1)) { 1181 error = EINVAL; 1182 break; 1183 } 1184 imo->imo_multicast_vif = i; 1185 break; 1186 1187 case IP_MULTICAST_IF: 1188 /* 1189 * Select the interface for outgoing multicast packets. 1190 */ 1191 error = sooptcopyin(sopt, &addr, sizeof addr, sizeof addr); 1192 if (error) 1193 break; 1194 /* 1195 * INADDR_ANY is used to remove a previous selection. 1196 * When no interface is selected, a default one is 1197 * chosen every time a multicast packet is sent. 1198 */ 1199 if (addr.s_addr == INADDR_ANY) { 1200 imo->imo_multicast_ifp = NULL; 1201 break; 1202 } 1203 /* 1204 * The selected interface is identified by its local 1205 * IP address. Find the interface and confirm that 1206 * it supports multicasting. 1207 */ 1208 s = splimp(); 1209 INADDR_TO_IFP(addr, ifp); 1210 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1211 splx(s); 1212 error = EADDRNOTAVAIL; 1213 break; 1214 } 1215 imo->imo_multicast_ifp = ifp; 1216 splx(s); 1217 break; 1218 1219 case IP_MULTICAST_TTL: 1220 /* 1221 * Set the IP time-to-live for outgoing multicast packets. 1222 * The original multicast API required a char argument, 1223 * which is inconsistent with the rest of the socket API. 1224 * We allow either a char or an int. 1225 */ 1226 if (sopt->sopt_valsize == 1) { 1227 u_char ttl; 1228 error = sooptcopyin(sopt, &ttl, 1, 1); 1229 if (error) 1230 break; 1231 imo->imo_multicast_ttl = ttl; 1232 } else { 1233 u_int ttl; 1234 error = sooptcopyin(sopt, &ttl, sizeof ttl, 1235 sizeof ttl); 1236 if (error) 1237 break; 1238 if (ttl > 255) 1239 error = EINVAL; 1240 else 1241 imo->imo_multicast_ttl = ttl; 1242 } 1243 break; 1244 1245 case IP_MULTICAST_LOOP: 1246 /* 1247 * Set the loopback flag for outgoing multicast packets. 1248 * Must be zero or one. The original multicast API required a 1249 * char argument, which is inconsistent with the rest 1250 * of the socket API. We allow either a char or an int. 1251 */ 1252 if (sopt->sopt_valsize == 1) { 1253 u_char loop; 1254 error = sooptcopyin(sopt, &loop, 1, 1); 1255 if (error) 1256 break; 1257 imo->imo_multicast_loop = !!loop; 1258 } else { 1259 u_int loop; 1260 error = sooptcopyin(sopt, &loop, sizeof loop, 1261 sizeof loop); 1262 if (error) 1263 break; 1264 imo->imo_multicast_loop = !!loop; 1265 } 1266 break; 1267 1268 case IP_ADD_MEMBERSHIP: 1269 /* 1270 * Add a multicast group membership. 1271 * Group must be a valid IP multicast address. 1272 */ 1273 error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq); 1274 if (error) 1275 break; 1276 1277 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { 1278 error = EINVAL; 1279 break; 1280 } 1281 s = splimp(); 1282 /* 1283 * If no interface address was provided, use the interface of 1284 * the route to the given multicast address. 1285 */ 1286 if (mreq.imr_interface.s_addr == INADDR_ANY) { 1287 bzero((caddr_t)&ro, sizeof(ro)); 1288 dst = (struct sockaddr_in *)&ro.ro_dst; 1289 dst->sin_len = sizeof(*dst); 1290 dst->sin_family = AF_INET; 1291 dst->sin_addr = mreq.imr_multiaddr; 1292 rtalloc(&ro); 1293 if (ro.ro_rt == NULL) { 1294 error = EADDRNOTAVAIL; 1295 splx(s); 1296 break; 1297 } 1298 ifp = ro.ro_rt->rt_ifp; 1299 rtfree(ro.ro_rt); 1300 } 1301 else { 1302 INADDR_TO_IFP(mreq.imr_interface, ifp); 1303 } 1304 1305 /* 1306 * See if we found an interface, and confirm that it 1307 * supports multicast. 1308 */ 1309 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { 1310 error = EADDRNOTAVAIL; 1311 splx(s); 1312 break; 1313 } 1314 /* 1315 * See if the membership already exists or if all the 1316 * membership slots are full. 1317 */ 1318 for (i = 0; i < imo->imo_num_memberships; ++i) { 1319 if (imo->imo_membership[i]->inm_ifp == ifp && 1320 imo->imo_membership[i]->inm_addr.s_addr 1321 == mreq.imr_multiaddr.s_addr) 1322 break; 1323 } 1324 if (i < imo->imo_num_memberships) { 1325 error = EADDRINUSE; 1326 splx(s); 1327 break; 1328 } 1329 if (i == IP_MAX_MEMBERSHIPS) { 1330 error = ETOOMANYREFS; 1331 splx(s); 1332 break; 1333 } 1334 /* 1335 * Everything looks good; add a new record to the multicast 1336 * address list for the given interface. 1337 */ 1338 if ((imo->imo_membership[i] = 1339 in_addmulti(&mreq.imr_multiaddr, ifp)) == NULL) { 1340 error = ENOBUFS; 1341 splx(s); 1342 break; 1343 } 1344 ++imo->imo_num_memberships; 1345 splx(s); 1346 break; 1347 1348 case IP_DROP_MEMBERSHIP: 1349 /* 1350 * Drop a multicast group membership. 1351 * Group must be a valid IP multicast address. 1352 */ 1353 error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq); 1354 if (error) 1355 break; 1356 1357 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) { 1358 error = EINVAL; 1359 break; 1360 } 1361 1362 s = splimp(); 1363 /* 1364 * If an interface address was specified, get a pointer 1365 * to its ifnet structure. 1366 */ 1367 if (mreq.imr_interface.s_addr == INADDR_ANY) 1368 ifp = NULL; 1369 else { 1370 INADDR_TO_IFP(mreq.imr_interface, ifp); 1371 if (ifp == NULL) { 1372 error = EADDRNOTAVAIL; 1373 splx(s); 1374 break; 1375 } 1376 } 1377 /* 1378 * Find the membership in the membership array. 1379 */ 1380 for (i = 0; i < imo->imo_num_memberships; ++i) { 1381 if ((ifp == NULL || 1382 imo->imo_membership[i]->inm_ifp == ifp) && 1383 imo->imo_membership[i]->inm_addr.s_addr == 1384 mreq.imr_multiaddr.s_addr) 1385 break; 1386 } 1387 if (i == imo->imo_num_memberships) { 1388 error = EADDRNOTAVAIL; 1389 splx(s); 1390 break; 1391 } 1392 /* 1393 * Give up the multicast address record to which the 1394 * membership points. 1395 */ 1396 in_delmulti(imo->imo_membership[i]); 1397 /* 1398 * Remove the gap in the membership array. 1399 */ 1400 for (++i; i < imo->imo_num_memberships; ++i) 1401 imo->imo_membership[i-1] = imo->imo_membership[i]; 1402 --imo->imo_num_memberships; 1403 splx(s); 1404 break; 1405 1406 default: 1407 error = EOPNOTSUPP; 1408 break; 1409 } 1410 1411 /* 1412 * If all options have default values, no need to keep the mbuf. 1413 */ 1414 if (imo->imo_multicast_ifp == NULL && 1415 imo->imo_multicast_vif == -1 && 1416 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && 1417 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && 1418 imo->imo_num_memberships == 0) { 1419 free(*imop, M_IPMOPTS); 1420 *imop = NULL; 1421 } 1422 1423 return (error); 1424 } 1425 1426 /* 1427 * Return the IP multicast options in response to user getsockopt(). 1428 */ 1429 static int 1430 ip_getmoptions(sopt, imo) 1431 struct sockopt *sopt; 1432 register struct ip_moptions *imo; 1433 { 1434 struct in_addr addr; 1435 struct in_ifaddr *ia; 1436 int error, optval; 1437 u_char coptval; 1438 1439 error = 0; 1440 switch (sopt->sopt_name) { 1441 case IP_MULTICAST_VIF: 1442 if (imo != NULL) 1443 optval = imo->imo_multicast_vif; 1444 else 1445 optval = -1; 1446 error = sooptcopyout(sopt, &optval, sizeof optval); 1447 break; 1448 1449 case IP_MULTICAST_IF: 1450 if (imo == NULL || imo->imo_multicast_ifp == NULL) 1451 addr.s_addr = INADDR_ANY; 1452 else { 1453 IFP_TO_IA(imo->imo_multicast_ifp, ia); 1454 addr.s_addr = (ia == NULL) ? INADDR_ANY 1455 : IA_SIN(ia)->sin_addr.s_addr; 1456 } 1457 error = sooptcopyout(sopt, &addr, sizeof addr); 1458 break; 1459 1460 case IP_MULTICAST_TTL: 1461 if (imo == 0) 1462 optval = coptval = IP_DEFAULT_MULTICAST_TTL; 1463 else 1464 optval = coptval = imo->imo_multicast_ttl; 1465 if (sopt->sopt_valsize == 1) 1466 error = sooptcopyout(sopt, &coptval, 1); 1467 else 1468 error = sooptcopyout(sopt, &optval, sizeof optval); 1469 break; 1470 1471 case IP_MULTICAST_LOOP: 1472 if (imo == 0) 1473 optval = coptval = IP_DEFAULT_MULTICAST_LOOP; 1474 else 1475 optval = coptval = imo->imo_multicast_loop; 1476 if (sopt->sopt_valsize == 1) 1477 error = sooptcopyout(sopt, &coptval, 1); 1478 else 1479 error = sooptcopyout(sopt, &optval, sizeof optval); 1480 break; 1481 1482 default: 1483 error = ENOPROTOOPT; 1484 break; 1485 } 1486 return (error); 1487 } 1488 1489 /* 1490 * Discard the IP multicast options. 1491 */ 1492 void 1493 ip_freemoptions(imo) 1494 register struct ip_moptions *imo; 1495 { 1496 register int i; 1497 1498 if (imo != NULL) { 1499 for (i = 0; i < imo->imo_num_memberships; ++i) 1500 in_delmulti(imo->imo_membership[i]); 1501 free(imo, M_IPMOPTS); 1502 } 1503 } 1504 1505 /* 1506 * Routine called from ip_output() to loop back a copy of an IP multicast 1507 * packet to the input queue of a specified interface. Note that this 1508 * calls the output routine of the loopback "driver", but with an interface 1509 * pointer that might NOT be a loopback interface -- evil, but easier than 1510 * replicating that code here. 1511 */ 1512 static void 1513 ip_mloopback(ifp, m, dst, hlen) 1514 struct ifnet *ifp; 1515 register struct mbuf *m; 1516 register struct sockaddr_in *dst; 1517 int hlen; 1518 { 1519 register struct ip *ip; 1520 struct mbuf *copym; 1521 1522 copym = m_copy(m, 0, M_COPYALL); 1523 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen)) 1524 copym = m_pullup(copym, hlen); 1525 if (copym != NULL) { 1526 /* 1527 * We don't bother to fragment if the IP length is greater 1528 * than the interface's MTU. Can this possibly matter? 1529 */ 1530 ip = mtod(copym, struct ip *); 1531 ip->ip_len = htons((u_short)ip->ip_len); 1532 ip->ip_off = htons((u_short)ip->ip_off); 1533 ip->ip_sum = 0; 1534 if (ip->ip_vhl == IP_VHL_BORING) { 1535 ip->ip_sum = in_cksum_hdr(ip); 1536 } else { 1537 ip->ip_sum = in_cksum(copym, hlen); 1538 } 1539 /* 1540 * NB: 1541 * It's not clear whether there are any lingering 1542 * reentrancy problems in other areas which might 1543 * be exposed by using ip_input directly (in 1544 * particular, everything which modifies the packet 1545 * in-place). Yet another option is using the 1546 * protosw directly to deliver the looped back 1547 * packet. For the moment, we'll err on the side 1548 * of safety by using if_simloop(). 1549 */ 1550 #if 1 /* XXX */ 1551 if (dst->sin_family != AF_INET) { 1552 printf("ip_mloopback: bad address family %d\n", 1553 dst->sin_family); 1554 dst->sin_family = AF_INET; 1555 } 1556 #endif 1557 1558 #ifdef notdef 1559 copym->m_pkthdr.rcvif = ifp; 1560 ip_input(copym); 1561 #else 1562 if_simloop(ifp, copym, (struct sockaddr *)dst, 0); 1563 #endif 1564 } 1565 }
Cache object: cbb21c57a464ff33316a9e5111bc96b2
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