sys/netinet/ip_output.c

   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. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  *      @(#)ip_output.c 8.3 (Berkeley) 1/21/94
  30  * $FreeBSD: src/sys/netinet/ip_output.c,v 1.99.2.37 2003/04/15 06:44:45 silby Exp $
  31  * $DragonFly: src/sys/netinet/ip_output.c,v 1.67 2008/10/28 03:07:28 sephe Exp $
  32  */
  33
  34 #define _IP_VHL
  35
  36 #include "opt_ipfw.h"
  37 #include "opt_ipdn.h"
  38 #include "opt_ipdivert.h"
  39 #include "opt_ipfilter.h"
  40 #include "opt_ipsec.h"
  41 #include "opt_mbuf_stress_test.h"
  42 #include "opt_mpls.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 #include <sys/proc.h>
  53 #include <sys/sysctl.h>
  54 #include <sys/thread2.h>
  55 #include <sys/in_cksum.h>
  56 #include <sys/lock.h>
  57
  58 #include <net/if.h>
  59 #include <net/netisr.h>
  60 #include <net/pfil.h>
  61 #include <net/route.h>
  62
  63 #include <netinet/in.h>
  64 #include <netinet/in_systm.h>
  65 #include <netinet/ip.h>
  66 #include <netinet/in_pcb.h>
  67 #include <netinet/in_var.h>
  68 #include <netinet/ip_var.h>
  69
  70 #include <netproto/mpls/mpls_var.h>
  71
  72 static MALLOC_DEFINE(M_IPMOPTS, "ip_moptions", "internet multicast options");
  73
  74 #ifdef IPSEC
  75 #include <netinet6/ipsec.h>
  76 #include <netproto/key/key.h>
  77 #ifdef IPSEC_DEBUG
  78 #include <netproto/key/key_debug.h>
  79 #else
  80 #define KEYDEBUG(lev,arg)
  81 #endif
  82 #endif /*IPSEC*/
  83
  84 #ifdef FAST_IPSEC
  85 #include <netproto/ipsec/ipsec.h>
  86 #include <netproto/ipsec/xform.h>
  87 #include <netproto/ipsec/key.h>
  88 #endif /*FAST_IPSEC*/
  89
  90 #include <net/ipfw/ip_fw.h>
  91 #include <net/dummynet/ip_dummynet.h>
  92
  93 #define print_ip(x, a, y)        kprintf("%s %d.%d.%d.%d%s",\
  94                                 x, (ntohl(a.s_addr)>>24)&0xFF,\
  95                                   (ntohl(a.s_addr)>>16)&0xFF,\
  96                                   (ntohl(a.s_addr)>>8)&0xFF,\
  97                                   (ntohl(a.s_addr))&0xFF, y);
  98
  99 u_short ip_id;
 100
 101 #ifdef MBUF_STRESS_TEST
 102 int mbuf_frag_size = 0;
 103 SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW,
 104         &mbuf_frag_size, 0, "Fragment outgoing mbufs to this size");
 105 #endif
 106
 107 static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *);
 108 static struct ifnet *ip_multicast_if(struct in_addr *, int *);
 109 static void     ip_mloopback
 110         (struct ifnet *, struct mbuf *, struct sockaddr_in *, int);
 111 static int      ip_getmoptions
 112         (struct sockopt *, struct ip_moptions *);
 113 static int      ip_pcbopts(int, struct mbuf **, struct mbuf *);
 114 static int      ip_setmoptions
 115         (struct sockopt *, struct ip_moptions **);
 116
 117 int     ip_optcopy(struct ip *, struct ip *);
 118
 119 extern  int route_assert_owner_access;
 120
 121 extern  struct protosw inetsw[];
 122
 123 static int
 124 ip_localforward(struct mbuf *m, const struct sockaddr_in *dst, int hlen)
 125 {
 126         struct in_ifaddr_container *iac;
 127
 128         /*
 129          * We need to figure out if we have been forwarded to a local
 130          * socket.  If so, then we should somehow "loop back" to
 131          * ip_input(), and get directed to the PCB as if we had received
 132          * this packet.  This is because it may be difficult to identify
 133          * the packets you want to forward until they are being output
 134          * and have selected an interface (e.g. locally initiated
 135          * packets).  If we used the loopback inteface, we would not be
 136          * able to control what happens as the packet runs through
 137          * ip_input() as it is done through a ISR.
 138          */
 139         LIST_FOREACH(iac, INADDR_HASH(dst->sin_addr.s_addr), ia_hash) {
 140                 /*
 141                  * If the addr to forward to is one of ours, we pretend
 142                  * to be the destination for this packet.
 143                  */
 144                 if (IA_SIN(iac->ia)->sin_addr.s_addr == dst->sin_addr.s_addr)
 145                         break;
 146         }
 147         if (iac != NULL) {
 148                 struct ip *ip;
 149
 150                 if (m->m_pkthdr.rcvif == NULL)
 151                         m->m_pkthdr.rcvif = ifunit("lo0");
 152                 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
 153                         m->m_pkthdr.csum_flags |= CSUM_DATA_VALID |
 154                                                   CSUM_PSEUDO_HDR;
 155                         m->m_pkthdr.csum_data = 0xffff;
 156                 }
 157                 m->m_pkthdr.csum_flags |= CSUM_IP_CHECKED | CSUM_IP_VALID;
 158
 159                 /*
 160                  * Make sure that the IP header is in one mbuf,
 161                  * required by ip_input
 162                  */
 163                 if (m->m_len < hlen) {
 164                         m = m_pullup(m, hlen);
 165                         if (m == NULL) {
 166                                 /* The packet was freed; we are done */
 167                                 return 1;
 168                         }
 169                 }
 170                 ip = mtod(m, struct ip *);
 171
 172                 ip->ip_len = htons(ip->ip_len);
 173                 ip->ip_off = htons(ip->ip_off);
 174                 ip_input(m);
 175
 176                 return 1; /* The packet gets forwarded locally */
 177         }
 178         return 0;
 179 }
 180
 181 /*
 182  * IP output.  The packet in mbuf chain m contains a skeletal IP
 183  * header (with len, off, ttl, proto, tos, src, dst).
 184  * The mbuf chain containing the packet will be freed.
 185  * The mbuf opt, if present, will not be freed.
 186  */
 187 int
 188 ip_output(struct mbuf *m0, struct mbuf *opt, struct route *ro,
 189           int flags, struct ip_moptions *imo, struct inpcb *inp)
 190 {
 191         struct ip *ip;
 192         struct ifnet *ifp = NULL;       /* keep compiler happy */
 193         struct mbuf *m;
 194         int hlen = sizeof(struct ip);
 195         int len, error = 0;
 196         struct sockaddr_in *dst = NULL; /* keep compiler happy */
 197         struct in_ifaddr *ia = NULL;
 198         int isbroadcast, sw_csum;
 199         struct in_addr pkt_dst;
 200         struct route iproute;
 201         struct m_tag *mtag;
 202 #ifdef IPSEC
 203         struct secpolicy *sp = NULL;
 204         struct socket *so = inp ? inp->inp_socket : NULL;
 205 #endif
 206 #ifdef FAST_IPSEC
 207         struct secpolicy *sp = NULL;
 208         struct tdb_ident *tdbi;
 209 #endif /* FAST_IPSEC */
 210         struct sockaddr_in *next_hop = NULL;
 211         int src_was_INADDR_ANY = 0;     /* as the name says... */
 212
 213         m = m0;
 214         M_ASSERTPKTHDR(m);
 215
 216         if (ro == NULL) {
 217                 ro = &iproute;
 218                 bzero(ro, sizeof *ro);
 219         } else if (ro->ro_rt != NULL && ro->ro_rt->rt_cpuid != mycpuid) {
 220                 if (flags & IP_DEBUGROUTE) {
 221                         if (route_assert_owner_access) {
 222                                 panic("ip_output: "
 223                                       "rt rt_cpuid %d accessed on cpu %d\n",
 224                                       ro->ro_rt->rt_cpuid, mycpuid);
 225                         } else {
 226                                 kprintf("ip_output: "
 227                                         "rt rt_cpuid %d accessed on cpu %d\n",
 228                                         ro->ro_rt->rt_cpuid, mycpuid);
 229                                 backtrace();
 230                         }
 231                 }
 232
 233                 /*
 234                  * XXX
 235                  * If the cached rtentry's owner CPU is not the current CPU,
 236                  * then don't touch the cached rtentry (remote free is too
 237                  * expensive in this context); just relocate the route.
 238                  */
 239                 ro = &iproute;
 240                 bzero(ro, sizeof *ro);
 241         }
 242
 243         if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) {
 244                 /* Next hop */
 245                 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
 246                 KKASSERT(mtag != NULL);
 247                 next_hop = m_tag_data(mtag);
 248         }
 249
 250         if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) {
 251                 struct dn_pkt *dn_pkt;
 252
 253                 /* Extract info from dummynet tag */
 254                 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL);
 255                 KKASSERT(mtag != NULL);
 256                 dn_pkt = m_tag_data(mtag);
 257
 258                 /*
 259                  * The packet was already tagged, so part of the
 260                  * processing was already done, and we need to go down.
 261                  * Get the calculated parameters from the tag.
 262                  */
 263                 ifp = dn_pkt->ifp;
 264
 265                 KKASSERT(ro == &iproute);
 266                 *ro = dn_pkt->ro; /* structure copy */
 267                 KKASSERT(ro->ro_rt == NULL || ro->ro_rt->rt_cpuid == mycpuid);
 268
 269                 dst = dn_pkt->dn_dst;
 270                 if (dst == (struct sockaddr_in *)&(dn_pkt->ro.ro_dst)) {
 271                         /* If 'dst' points into dummynet tag, adjust it */
 272                         dst = (struct sockaddr_in *)&(ro->ro_dst);
 273                 }
 274
 275                 ip = mtod(m, struct ip *);
 276                 hlen = IP_VHL_HL(ip->ip_vhl) << 2 ;
 277                 if (ro->ro_rt)
 278                         ia = ifatoia(ro->ro_rt->rt_ifa);
 279                 goto sendit;
 280         }
 281
 282         if (opt) {
 283                 len = 0;
 284                 m = ip_insertoptions(m, opt, &len);
 285                 if (len != 0)
 286                         hlen = len;
 287         }
 288         ip = mtod(m, struct ip *);
 289
 290         /*
 291          * Fill in IP header.
 292          */
 293         if (!(flags & (IP_FORWARDING|IP_RAWOUTPUT))) {
 294                 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, hlen >> 2);
 295                 ip->ip_off &= IP_DF;
 296                 ip->ip_id = ip_newid();
 297                 ipstat.ips_localout++;
 298         } else {
 299                 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
 300         }
 301
 302 reroute:
 303         pkt_dst = next_hop ? next_hop->sin_addr : ip->ip_dst;
 304
 305 #ifdef INVARIANTS
 306         if (IN_MULTICAST(ntohl(pkt_dst.s_addr))) {
 307                 /*
 308                  * XXX
 309                  * Multicast is not MPSAFE yet.  Caller must hold
 310                  * BGL when output a multicast IP packet.
 311                  */
 312                 ASSERT_MP_LOCK_HELD(curthread);
 313         }
 314 #endif
 315
 316         dst = (struct sockaddr_in *)&ro->ro_dst;
 317         /*
 318          * If there is a cached route,
 319          * check that it is to the same destination
 320          * and is still up.  If not, free it and try again.
 321          * The address family should also be checked in case of sharing the
 322          * cache with IPv6.
 323          */
 324         if (ro->ro_rt &&
 325             (!(ro->ro_rt->rt_flags & RTF_UP) ||
 326              dst->sin_family != AF_INET ||
 327              dst->sin_addr.s_addr != pkt_dst.s_addr)) {
 328                 rtfree(ro->ro_rt);
 329                 ro->ro_rt = (struct rtentry *)NULL;
 330         }
 331         if (ro->ro_rt == NULL) {
 332                 bzero(dst, sizeof *dst);
 333                 dst->sin_family = AF_INET;
 334                 dst->sin_len = sizeof *dst;
 335                 dst->sin_addr = pkt_dst;
 336         }
 337         /*
 338          * If routing to interface only,
 339          * short circuit routing lookup.
 340          */
 341         if (flags & IP_ROUTETOIF) {
 342                 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL &&
 343                     (ia = ifatoia(ifa_ifwithnet(sintosa(dst)))) == NULL) {
 344                         ipstat.ips_noroute++;
 345                         error = ENETUNREACH;
 346                         goto bad;
 347                 }
 348                 ifp = ia->ia_ifp;
 349                 ip->ip_ttl = 1;
 350                 isbroadcast = in_broadcast(dst->sin_addr, ifp);
 351         } else if (IN_MULTICAST(ntohl(pkt_dst.s_addr)) &&
 352                    imo != NULL && imo->imo_multicast_ifp != NULL) {
 353                 /*
 354                  * Bypass the normal routing lookup for multicast
 355                  * packets if the interface is specified.
 356                  */
 357                 ifp = imo->imo_multicast_ifp;
 358                 ia = IFP_TO_IA(ifp);
 359                 isbroadcast = 0;        /* fool gcc */
 360         } else {
 361                 /*
 362                  * If this is the case, we probably don't want to allocate
 363                  * a protocol-cloned route since we didn't get one from the
 364                  * ULP.  This lets TCP do its thing, while not burdening
 365                  * forwarding or ICMP with the overhead of cloning a route.
 366                  * Of course, we still want to do any cloning requested by
 367                  * the link layer, as this is probably required in all cases
 368                  * for correct operation (as it is for ARP).
 369                  */
 370                 if (ro->ro_rt == NULL)
 371                         rtalloc_ign(ro, RTF_PRCLONING);
 372                 if (ro->ro_rt == NULL) {
 373                         ipstat.ips_noroute++;
 374                         error = EHOSTUNREACH;
 375                         goto bad;
 376                 }
 377                 ia = ifatoia(ro->ro_rt->rt_ifa);
 378                 ifp = ro->ro_rt->rt_ifp;
 379                 ro->ro_rt->rt_use++;
 380                 if (ro->ro_rt->rt_flags & RTF_GATEWAY)
 381                         dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway;
 382                 if (ro->ro_rt->rt_flags & RTF_HOST)
 383                         isbroadcast = (ro->ro_rt->rt_flags & RTF_BROADCAST);
 384                 else
 385                         isbroadcast = in_broadcast(dst->sin_addr, ifp);
 386         }
 387         if (IN_MULTICAST(ntohl(pkt_dst.s_addr))) {
 388                 struct in_multi *inm;
 389
 390                 m->m_flags |= M_MCAST;
 391                 /*
 392                  * IP destination address is multicast.  Make sure "dst"
 393                  * still points to the address in "ro".  (It may have been
 394                  * changed to point to a gateway address, above.)
 395                  */
 396                 dst = (struct sockaddr_in *)&ro->ro_dst;
 397                 /*
 398                  * See if the caller provided any multicast options
 399                  */
 400                 if (imo != NULL) {
 401                         ip->ip_ttl = imo->imo_multicast_ttl;
 402                         if (imo->imo_multicast_vif != -1) {
 403                                 ip->ip_src.s_addr =
 404                                     ip_mcast_src ?
 405                                     ip_mcast_src(imo->imo_multicast_vif) :
 406                                     INADDR_ANY;
 407                         }
 408                 } else {
 409                         ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL;
 410                 }
 411                 /*
 412                  * Confirm that the outgoing interface supports multicast.
 413                  */
 414                 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) {
 415                         if (!(ifp->if_flags & IFF_MULTICAST)) {
 416                                 ipstat.ips_noroute++;
 417                                 error = ENETUNREACH;
 418                                 goto bad;
 419                         }
 420                 }
 421                 /*
 422                  * If source address not specified yet, use address
 423                  * of outgoing interface.
 424                  */
 425                 if (ip->ip_src.s_addr == INADDR_ANY) {
 426                         /* Interface may have no addresses. */
 427                         if (ia != NULL)
 428                                 ip->ip_src = IA_SIN(ia)->sin_addr;
 429                 }
 430
 431                 IN_LOOKUP_MULTI(pkt_dst, ifp, inm);
 432                 if (inm != NULL &&
 433                     (imo == NULL || imo->imo_multicast_loop)) {
 434                         /*
 435                          * If we belong to the destination multicast group
 436                          * on the outgoing interface, and the caller did not
 437                          * forbid loopback, loop back a copy.
 438                          */
 439                         ip_mloopback(ifp, m, dst, hlen);
 440                 } else {
 441                         /*
 442                          * If we are acting as a multicast router, perform
 443                          * multicast forwarding as if the packet had just
 444                          * arrived on the interface to which we are about
 445                          * to send.  The multicast forwarding function
 446                          * recursively calls this function, using the
 447                          * IP_FORWARDING flag to prevent infinite recursion.
 448                          *
 449                          * Multicasts that are looped back by ip_mloopback(),
 450                          * above, will be forwarded by the ip_input() routine,
 451                          * if necessary.
 452                          */
 453                         if (ip_mrouter && !(flags & IP_FORWARDING)) {
 454                                 /*
 455                                  * If rsvp daemon is not running, do not
 456                                  * set ip_moptions. This ensures that the packet
 457                                  * is multicast and not just sent down one link
 458                                  * as prescribed by rsvpd.
 459                                  */
 460                                 if (!rsvp_on)
 461                                         imo = NULL;
 462                                 if (ip_mforward &&
 463                                     ip_mforward(ip, ifp, m, imo) != 0) {
 464                                         m_freem(m);
 465                                         goto done;
 466                                 }
 467                         }
 468                 }
 469
 470                 /*
 471                  * Multicasts with a time-to-live of zero may be looped-
 472                  * back, above, but must not be transmitted on a network.
 473                  * Also, multicasts addressed to the loopback interface
 474                  * are not sent -- the above call to ip_mloopback() will
 475                  * loop back a copy if this host actually belongs to the
 476                  * destination group on the loopback interface.
 477                  */
 478                 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) {
 479                         m_freem(m);
 480                         goto done;
 481                 }
 482
 483                 goto sendit;
 484         } else {
 485                 m->m_flags &= ~M_MCAST;
 486         }
 487
 488         /*
 489          * If the source address is not specified yet, use the address
 490          * of the outoing interface. In case, keep note we did that, so
 491          * if the the firewall changes the next-hop causing the output
 492          * interface to change, we can fix that.
 493          */
 494         if (ip->ip_src.s_addr == INADDR_ANY || src_was_INADDR_ANY) {
 495                 /* Interface may have no addresses. */
 496                 if (ia != NULL) {
 497                         ip->ip_src = IA_SIN(ia)->sin_addr;
 498                         src_was_INADDR_ANY = 1;
 499                 }
 500         }
 501
 502 #ifdef ALTQ
 503         /*
 504          * Disable packet drop hack.
 505          * Packetdrop should be done by queueing.
 506          */
 507 #else /* !ALTQ */
 508         /*
 509          * Verify that we have any chance at all of being able to queue
 510          *      the packet or packet fragments
 511          */
 512         if ((ifp->if_snd.ifq_len + ip->ip_len / ifp->if_mtu + 1) >=
 513             ifp->if_snd.ifq_maxlen) {
 514                 error = ENOBUFS;
 515                 ipstat.ips_odropped++;
 516                 goto bad;
 517         }
 518 #endif /* !ALTQ */
 519
 520         /*
 521          * Look for broadcast address and
 522          * verify user is allowed to send
 523          * such a packet.
 524          */
 525         if (isbroadcast) {
 526                 if (!(ifp->if_flags & IFF_BROADCAST)) {
 527                         error = EADDRNOTAVAIL;
 528                         goto bad;
 529                 }
 530                 if (!(flags & IP_ALLOWBROADCAST)) {
 531                         error = EACCES;
 532                         goto bad;
 533                 }
 534                 /* don't allow broadcast messages to be fragmented */
 535                 if (ip->ip_len > ifp->if_mtu) {
 536                         error = EMSGSIZE;
 537                         goto bad;
 538                 }
 539                 m->m_flags |= M_BCAST;
 540         } else {
 541                 m->m_flags &= ~M_BCAST;
 542         }
 543
 544 sendit:
 545 #ifdef IPSEC
 546         /* get SP for this packet */
 547         if (so == NULL)
 548                 sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error);
 549         else
 550                 sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error);
 551
 552         if (sp == NULL) {
 553                 ipsecstat.out_inval++;
 554                 goto bad;
 555         }
 556
 557         error = 0;
 558
 559         /* check policy */
 560         switch (sp->policy) {
 561         case IPSEC_POLICY_DISCARD:
 562                 /*
 563                  * This packet is just discarded.
 564                  */
 565                 ipsecstat.out_polvio++;
 566                 goto bad;
 567
 568         case IPSEC_POLICY_BYPASS:
 569         case IPSEC_POLICY_NONE:
 570                 /* no need to do IPsec. */
 571                 goto skip_ipsec;
 572
 573         case IPSEC_POLICY_IPSEC:
 574                 if (sp->req == NULL) {
 575                         /* acquire a policy */
 576                         error = key_spdacquire(sp);
 577                         goto bad;
 578                 }
 579                 break;
 580
 581         case IPSEC_POLICY_ENTRUST:
 582         default:
 583                 kprintf("ip_output: Invalid policy found. %d\n", sp->policy);
 584         }
 585     {
 586         struct ipsec_output_state state;
 587         bzero(&state, sizeof state);
 588         state.m = m;
 589         if (flags & IP_ROUTETOIF) {
 590                 state.ro = &iproute;
 591                 bzero(&iproute, sizeof iproute);
 592         } else
 593                 state.ro = ro;
 594         state.dst = (struct sockaddr *)dst;
 595
 596         ip->ip_sum = 0;
 597
 598         /*
 599          * XXX
 600          * delayed checksums are not currently compatible with IPsec
 601          */
 602         if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
 603                 in_delayed_cksum(m);
 604                 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
 605         }
 606
 607         ip->ip_len = htons(ip->ip_len);
 608         ip->ip_off = htons(ip->ip_off);
 609
 610         error = ipsec4_output(&state, sp, flags);
 611
 612         m = state.m;
 613         if (flags & IP_ROUTETOIF) {
 614                 /*
 615                  * if we have tunnel mode SA, we may need to ignore
 616                  * IP_ROUTETOIF.
 617                  */
 618                 if (state.ro != &iproute || state.ro->ro_rt != NULL) {
 619                         flags &= ~IP_ROUTETOIF;
 620                         ro = state.ro;
 621                 }
 622         } else
 623                 ro = state.ro;
 624         dst = (struct sockaddr_in *)state.dst;
 625         if (error) {
 626                 /* mbuf is already reclaimed in ipsec4_output. */
 627                 m0 = NULL;
 628                 switch (error) {
 629                 case EHOSTUNREACH:
 630                 case ENETUNREACH:
 631                 case EMSGSIZE:
 632                 case ENOBUFS:
 633                 case ENOMEM:
 634                         break;
 635                 default:
 636                         kprintf("ip4_output (ipsec): error code %d\n", error);
 637                         /*fall through*/
 638                 case ENOENT:
 639                         /* don't show these error codes to the user */
 640                         error = 0;
 641                         break;
 642                 }
 643                 goto bad;
 644         }
 645     }
 646
 647         /* be sure to update variables that are affected by ipsec4_output() */
 648         ip = mtod(m, struct ip *);
 649 #ifdef _IP_VHL
 650         hlen = IP_VHL_HL(ip->ip_vhl) << 2;
 651 #else
 652         hlen = ip->ip_hl << 2;
 653 #endif
 654         if (ro->ro_rt == NULL) {
 655                 if (!(flags & IP_ROUTETOIF)) {
 656                         kprintf("ip_output: "
 657                                 "can't update route after IPsec processing\n");
 658                         error = EHOSTUNREACH;   /*XXX*/
 659                         goto bad;
 660                 }
 661         } else {
 662                 ia = ifatoia(ro->ro_rt->rt_ifa);
 663                 ifp = ro->ro_rt->rt_ifp;
 664         }
 665
 666         /* make it flipped, again. */
 667         ip->ip_len = ntohs(ip->ip_len);
 668         ip->ip_off = ntohs(ip->ip_off);
 669 skip_ipsec:
 670 #endif /*IPSEC*/
 671 #ifdef FAST_IPSEC
 672         /*
 673          * Check the security policy (SP) for the packet and, if
 674          * required, do IPsec-related processing.  There are two
 675          * cases here; the first time a packet is sent through
 676          * it will be untagged and handled by ipsec4_checkpolicy.
 677          * If the packet is resubmitted to ip_output (e.g. after
 678          * AH, ESP, etc. processing), there will be a tag to bypass
 679          * the lookup and related policy checking.
 680          */
 681         mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL);
 682         crit_enter();
 683         if (mtag != NULL) {
 684                 tdbi = (struct tdb_ident *)m_tag_data(mtag);
 685                 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND);
 686                 if (sp == NULL)
 687                         error = -EINVAL;        /* force silent drop */
 688                 m_tag_delete(m, mtag);
 689         } else {
 690                 sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags,
 691                                         &error, inp);
 692         }
 693         /*
 694          * There are four return cases:
 695          *    sp != NULL                    apply IPsec policy
 696          *    sp == NULL, error == 0        no IPsec handling needed
 697          *    sp == NULL, error == -EINVAL  discard packet w/o error
 698          *    sp == NULL, error != 0        discard packet, report error
 699          */
 700         if (sp != NULL) {
 701                 /* Loop detection, check if ipsec processing already done */
 702                 KASSERT(sp->req != NULL, ("ip_output: no ipsec request"));
 703                 for (mtag = m_tag_first(m); mtag != NULL;
 704                      mtag = m_tag_next(m, mtag)) {
 705                         if (mtag->m_tag_cookie != MTAG_ABI_COMPAT)
 706                                 continue;
 707                         if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE &&
 708                             mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED)
 709                                 continue;
 710                         /*
 711                          * Check if policy has an SA associated with it.
 712                          * This can happen when an SP has yet to acquire
 713                          * an SA; e.g. on first reference.  If it occurs,
 714                          * then we let ipsec4_process_packet do its thing.
 715                          */
 716                         if (sp->req->sav == NULL)
 717                                 break;
 718                         tdbi = (struct tdb_ident *)m_tag_data(mtag);
 719                         if (tdbi->spi == sp->req->sav->spi &&
 720                             tdbi->proto == sp->req->sav->sah->saidx.proto &&
 721                             bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst,
 722                                  sizeof(union sockaddr_union)) == 0) {
 723                                 /*
 724                                  * No IPsec processing is needed, free
 725                                  * reference to SP.
 726                                  *
 727                                  * NB: null pointer to avoid free at
 728                                  *     done: below.
 729                                  */
 730                                 KEY_FREESP(&sp), sp = NULL;
 731                                 crit_exit();
 732                                 goto spd_done;
 733                         }
 734                 }
 735
 736                 /*
 737                  * Do delayed checksums now because we send before
 738                  * this is done in the normal processing path.
 739                  */
 740                 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
 741                         in_delayed_cksum(m);
 742                         m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
 743                 }
 744
 745                 ip->ip_len = htons(ip->ip_len);
 746                 ip->ip_off = htons(ip->ip_off);
 747
 748                 /* NB: callee frees mbuf */
 749                 error = ipsec4_process_packet(m, sp->req, flags, 0);
 750                 /*
 751                  * Preserve KAME behaviour: ENOENT can be returned
 752                  * when an SA acquire is in progress.  Don't propagate
 753                  * this to user-level; it confuses applications.
 754                  *
 755                  * XXX this will go away when the SADB is redone.
 756                  */
 757                 if (error == ENOENT)
 758                         error = 0;
 759                 crit_exit();
 760                 goto done;
 761         } else {
 762                 crit_exit();
 763
 764                 if (error != 0) {
 765                         /*
 766                          * Hack: -EINVAL is used to signal that a packet
 767                          * should be silently discarded.  This is typically
 768                          * because we asked key management for an SA and
 769                          * it was delayed (e.g. kicked up to IKE).
 770                          */
 771                         if (error == -EINVAL)
 772                                 error = 0;
 773                         goto bad;
 774                 } else {
 775                         /* No IPsec processing for this packet. */
 776                 }
 777 #ifdef notyet
 778                 /*
 779                  * If deferred crypto processing is needed, check that
 780                  * the interface supports it.
 781                  */
 782                 mtag = m_tag_find(m, PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED, NULL);
 783                 if (mtag != NULL && !(ifp->if_capenable & IFCAP_IPSEC)) {
 784                         /* notify IPsec to do its own crypto */
 785                         ipsp_skipcrypto_unmark((struct tdb_ident *)m_tag_data(mtag));
 786                         error = EHOSTUNREACH;
 787                         goto bad;
 788                 }
 789 #endif
 790         }
 791 spd_done:
 792 #endif /* FAST_IPSEC */
 793
 794         /* We are already being fwd'd from a firewall. */
 795         if (next_hop != NULL)
 796                 goto pass;
 797
 798         /* No pfil hooks */
 799         if (!pfil_has_hooks(&inet_pfil_hook)) {
 800                 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) {
 801                         /*
 802                          * Strip dummynet tags from stranded packets
 803                          */
 804                         mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL);
 805                         KKASSERT(mtag != NULL);
 806                         m_tag_delete(m, mtag);
 807                         m->m_pkthdr.fw_flags &= ~DUMMYNET_MBUF_TAGGED;
 808                 }
 809                 goto pass;
 810         }
 811
 812         /*
 813          * IpHack's section.
 814          * - Xlate: translate packet's addr/port (NAT).
 815          * - Firewall: deny/allow/etc.
 816          * - Wrap: fake packet's addr/port <unimpl.>
 817          * - Encapsulate: put it in another IP and send out. <unimp.>
 818          */
 819
 820         /*
 821          * Run through list of hooks for output packets.
 822          */
 823         error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, PFIL_OUT);
 824         if (error != 0 || m == NULL)
 825                 goto done;
 826         ip = mtod(m, struct ip *);
 827
 828         if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) {
 829                 /*
 830                  * Check dst to make sure it is directly reachable on the
 831                  * interface we previously thought it was.
 832                  * If it isn't (which may be likely in some situations) we have
 833                  * to re-route it (ie, find a route for the next-hop and the
 834                  * associated interface) and set them here. This is nested
 835                  * forwarding which in most cases is undesirable, except where
 836                  * such control is nigh impossible. So we do it here.
 837                  * And I'm babbling.
 838                  */
 839                 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
 840                 KKASSERT(mtag != NULL);
 841                 next_hop = m_tag_data(mtag);
 842
 843                 /*
 844                  * Try local forwarding first
 845                  */
 846                 if (ip_localforward(m, next_hop, hlen))
 847                         goto done;
 848
 849                 /*
 850                  * Relocate the route based on next_hop.
 851                  * If the current route is inp's cache, keep it untouched.
 852                  */
 853                 if (ro == &iproute && ro->ro_rt != NULL) {
 854                         RTFREE(ro->ro_rt);
 855                         ro->ro_rt = NULL;
 856                 }
 857                 ro = &iproute;
 858                 bzero(ro, sizeof *ro);
 859
 860                 /*
 861                  * Forwarding to broadcast address is not allowed.
 862                  * XXX Should we follow IP_ROUTETOIF?
 863                  */
 864                 flags &= ~(IP_ALLOWBROADCAST | IP_ROUTETOIF);
 865
 866                 /* We are doing forwarding now */
 867                 flags |= IP_FORWARDING;
 868
 869                 goto reroute;
 870         }
 871
 872         if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) {
 873                 struct dn_pkt *dn_pkt;
 874
 875                 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL);
 876                 KKASSERT(mtag != NULL);
 877                 dn_pkt = m_tag_data(mtag);
 878
 879                 /*
 880                  * Under certain cases it is not possible to recalculate
 881                  * 'ro' and 'dst', let alone 'flags', so just save them in
 882                  * dummynet tag and avoid the possible wrong reculcalation
 883                  * when we come back to ip_output() again.
 884                  *
 885                  * All other parameters have been already used and so they
 886                  * are not needed anymore.
 887                  * XXX if the ifp is deleted while a pkt is in dummynet,
 888                  * we are in trouble! (TODO use ifnet_detach_event)
 889                  *
 890                  * We need to copy *ro because for ICMP pkts (and maybe
 891                  * others) the caller passed a pointer into the stack;
 892                  * dst might also be a pointer into *ro so it needs to
 893                  * be updated.
 894                  */
 895                 dn_pkt->ro = *ro;
 896                 if (ro->ro_rt)
 897                         ro->ro_rt->rt_refcnt++;
 898                 if (dst == (struct sockaddr_in *)&ro->ro_dst) {
 899                         /* 'dst' points into 'ro' */
 900                         dst = (struct sockaddr_in *)&(dn_pkt->ro.ro_dst);
 901                 }
 902                 dn_pkt->dn_dst = dst;
 903                 dn_pkt->flags = flags;
 904
 905                 ip_dn_queue(m);
 906                 goto done;
 907         }
 908 pass:
 909         /* 127/8 must not appear on wire - RFC1122. */
 910         if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
 911             (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
 912                 if (!(ifp->if_flags & IFF_LOOPBACK)) {
 913                         ipstat.ips_badaddr++;
 914                         error = EADDRNOTAVAIL;
 915                         goto bad;
 916                 }
 917         }
 918
 919         m->m_pkthdr.csum_flags |= CSUM_IP;
 920         sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist;
 921         if (sw_csum & CSUM_DELAY_DATA) {
 922                 in_delayed_cksum(m);
 923                 sw_csum &= ~CSUM_DELAY_DATA;
 924         }
 925         m->m_pkthdr.csum_flags &= ifp->if_hwassist;
 926
 927         /*
 928          * If small enough for interface, or the interface will take
 929          * care of the fragmentation for us, can just send directly.
 930          */
 931         if (ip->ip_len <= ifp->if_mtu || ((ifp->if_hwassist & CSUM_FRAGMENT) &&
 932             !(ip->ip_off & IP_DF))) {
 933                 ip->ip_len = htons(ip->ip_len);
 934                 ip->ip_off = htons(ip->ip_off);
 935                 ip->ip_sum = 0;
 936                 if (sw_csum & CSUM_DELAY_IP) {
 937                         if (ip->ip_vhl == IP_VHL_BORING)
 938                                 ip->ip_sum = in_cksum_hdr(ip);
 939                         else
 940                                 ip->ip_sum = in_cksum(m, hlen);
 941                 }
 942
 943                 /* Record statistics for this interface address. */
 944                 if (!(flags & IP_FORWARDING) && ia) {
 945                         ia->ia_ifa.if_opackets++;
 946                         ia->ia_ifa.if_obytes += m->m_pkthdr.len;
 947                 }
 948
 949 #ifdef IPSEC
 950                 /* clean ipsec history once it goes out of the node */
 951                 ipsec_delaux(m);
 952 #endif
 953
 954 #ifdef MBUF_STRESS_TEST
 955                 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size) {
 956                         struct mbuf *m1, *m2;
 957                         int length, tmp;
 958
 959                         tmp = length = m->m_pkthdr.len;
 960
 961                         while ((length -= mbuf_frag_size) >= 1) {
 962                                 m1 = m_split(m, length, MB_DONTWAIT);
 963                                 if (m1 == NULL)
 964                                         break;
 965                                 m2 = m;
 966                                 while (m2->m_next != NULL)
 967                                         m2 = m2->m_next;
 968                                 m2->m_next = m1;
 969                         }
 970                         m->m_pkthdr.len = tmp;
 971                 }
 972 #endif
 973
 974 #ifdef MPLS
 975                 if (!mpls_output_process(m, ro->ro_rt))
 976                         goto done;
 977 #endif
 978                 error = ifp->if_output(ifp, m, (struct sockaddr *)dst,
 979                                        ro->ro_rt);
 980                 goto done;
 981         }
 982
 983         if (ip->ip_off & IP_DF) {
 984                 error = EMSGSIZE;
 985                 /*
 986                  * This case can happen if the user changed the MTU
 987                  * of an interface after enabling IP on it.  Because
 988                  * most netifs don't keep track of routes pointing to
 989                  * them, there is no way for one to update all its
 990                  * routes when the MTU is changed.
 991                  */
 992                 if ((ro->ro_rt->rt_flags & (RTF_UP | RTF_HOST)) &&
 993                     !(ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) &&
 994                     (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)) {
 995                         ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu;
 996                 }
 997                 ipstat.ips_cantfrag++;
 998                 goto bad;
 999         }
1000
1001         /*
1002          * Too large for interface; fragment if possible. If successful,
1003          * on return, m will point to a list of packets to be sent.
1004          */
1005         error = ip_fragment(ip, &m, ifp->if_mtu, ifp->if_hwassist, sw_csum);
1006         if (error)
1007                 goto bad;
1008         for (; m; m = m0) {
1009                 m0 = m->m_nextpkt;
1010                 m->m_nextpkt = NULL;
1011 #ifdef IPSEC
1012                 /* clean ipsec history once it goes out of the node */
1013                 ipsec_delaux(m);
1014 #endif
1015                 if (error == 0) {
1016                         /* Record statistics for this interface address. */
1017                         if (ia != NULL) {
1018                                 ia->ia_ifa.if_opackets++;
1019                                 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
1020                         }
1021 #ifdef MPLS
1022                         if (!mpls_output_process(m, ro->ro_rt))
1023                                 continue;
1024 #endif
1025                         error = ifp->if_output(ifp, m, (struct sockaddr *)dst,
1026                                                ro->ro_rt);
1027                 } else {
1028                         m_freem(m);
1029                 }
1030         }
1031
1032         if (error == 0)
1033                 ipstat.ips_fragmented++;
1034
1035 done:
1036         if (ro == &iproute && ro->ro_rt != NULL) {
1037                 RTFREE(ro->ro_rt);
1038                 ro->ro_rt = NULL;
1039         }
1040 #ifdef IPSEC
1041         if (sp != NULL) {
1042                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
1043                         kprintf("DP ip_output call free SP:%p\n", sp));
1044                 key_freesp(sp);
1045         }
1046 #endif
1047 #ifdef FAST_IPSEC
1048         if (sp != NULL)
1049                 KEY_FREESP(&sp);
1050 #endif
1051         return (error);
1052 bad:
1053         m_freem(m);
1054         goto done;
1055 }
1056
1057 /*
1058  * Create a chain of fragments which fit the given mtu. m_frag points to the
1059  * mbuf to be fragmented; on return it points to the chain with the fragments.
1060  * Return 0 if no error. If error, m_frag may contain a partially built
1061  * chain of fragments that should be freed by the caller.
1062  *
1063  * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist)
1064  * sw_csum contains the delayed checksums flags (e.g., CSUM_DELAY_IP).
1065  */
1066 int
1067 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
1068             u_long if_hwassist_flags, int sw_csum)
1069 {
1070         int error = 0;
1071         int hlen = IP_VHL_HL(ip->ip_vhl) << 2;
1072         int len = (mtu - hlen) & ~7;    /* size of payload in each fragment */
1073         int off;
1074         struct mbuf *m0 = *m_frag;      /* the original packet          */
1075         int firstlen;
1076         struct mbuf **mnext;
1077         int nfrags;
1078
1079         if (ip->ip_off & IP_DF) {       /* Fragmentation not allowed */
1080                 ipstat.ips_cantfrag++;
1081                 return EMSGSIZE;
1082         }
1083
1084         /*
1085          * Must be able to put at least 8 bytes per fragment.
1086          */
1087         if (len < 8)
1088                 return EMSGSIZE;
1089
1090         /*
1091          * If the interface will not calculate checksums on
1092          * fragmented packets, then do it here.
1093          */
1094         if ((m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) &&
1095             !(if_hwassist_flags & CSUM_IP_FRAGS)) {
1096                 in_delayed_cksum(m0);
1097                 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
1098         }
1099
1100         if (len > PAGE_SIZE) {
1101                 /*
1102                  * Fragment large datagrams such that each segment
1103                  * contains a multiple of PAGE_SIZE amount of data,
1104                  * plus headers. This enables a receiver to perform
1105                  * page-flipping zero-copy optimizations.
1106                  *
1107                  * XXX When does this help given that sender and receiver
1108                  * could have different page sizes, and also mtu could
1109                  * be less than the receiver's page size ?
1110                  */
1111                 int newlen;
1112                 struct mbuf *m;
1113
1114                 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next)
1115                         off += m->m_len;
1116
1117                 /*
1118                  * firstlen (off - hlen) must be aligned on an
1119                  * 8-byte boundary
1120                  */
1121                 if (off < hlen)
1122                         goto smart_frag_failure;
1123                 off = ((off - hlen) & ~7) + hlen;
1124                 newlen = (~PAGE_MASK) & mtu;
1125                 if ((newlen + sizeof(struct ip)) > mtu) {
1126                         /* we failed, go back the default */
1127 smart_frag_failure:
1128                         newlen = len;
1129                         off = hlen + len;
1130                 }
1131                 len = newlen;
1132
1133         } else {
1134                 off = hlen + len;
1135         }
1136
1137         firstlen = off - hlen;
1138         mnext = &m0->m_nextpkt;         /* pointer to next packet */
1139
1140         /*
1141          * Loop through length of segment after first fragment,
1142          * make new header and copy data of each part and link onto chain.
1143          * Here, m0 is the original packet, m is the fragment being created.
1144          * The fragments are linked off the m_nextpkt of the original
1145          * packet, which after processing serves as the first fragment.
1146          */
1147         for (nfrags = 1; off < ip->ip_len; off += len, nfrags++) {
1148                 struct ip *mhip;        /* ip header on the fragment */
1149                 struct mbuf *m;
1150                 int mhlen = sizeof(struct ip);
1151
1152                 MGETHDR(m, MB_DONTWAIT, MT_HEADER);
1153                 if (m == NULL) {
1154                         error = ENOBUFS;
1155                         ipstat.ips_odropped++;
1156                         goto done;
1157                 }
1158                 m->m_flags |= (m0->m_flags & M_MCAST) | M_FRAG;
1159                 /*
1160                  * In the first mbuf, leave room for the link header, then
1161                  * copy the original IP header including options. The payload
1162                  * goes into an additional mbuf chain returned by m_copy().
1163                  */
1164                 m->m_data += max_linkhdr;
1165                 mhip = mtod(m, struct ip *);
1166                 *mhip = *ip;
1167                 if (hlen > sizeof(struct ip)) {
1168                         mhlen = ip_optcopy(ip, mhip) + sizeof(struct ip);
1169                         mhip->ip_vhl = IP_MAKE_VHL(IPVERSION, mhlen >> 2);
1170                 }
1171                 m->m_len = mhlen;
1172                 /* XXX do we need to add ip->ip_off below ? */
1173                 mhip->ip_off = ((off - hlen) >> 3) + ip->ip_off;
1174                 if (off + len >= ip->ip_len) {  /* last fragment */
1175                         len = ip->ip_len - off;
1176                         m->m_flags |= M_LASTFRAG;
1177                 } else
1178                         mhip->ip_off |= IP_MF;
1179                 mhip->ip_len = htons((u_short)(len + mhlen));
1180                 m->m_next = m_copy(m0, off, len);
1181                 if (m->m_next == NULL) {                /* copy failed */
1182                         m_free(m);
1183                         error = ENOBUFS;        /* ??? */
1184                         ipstat.ips_odropped++;
1185                         goto done;
1186                 }
1187                 m->m_pkthdr.len = mhlen + len;
1188                 m->m_pkthdr.rcvif = (struct ifnet *)NULL;
1189                 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags;
1190                 mhip->ip_off = htons(mhip->ip_off);
1191                 mhip->ip_sum = 0;
1192                 if (sw_csum & CSUM_DELAY_IP)
1193                         mhip->ip_sum = in_cksum(m, mhlen);
1194                 *mnext = m;
1195                 mnext = &m->m_nextpkt;
1196         }
1197         ipstat.ips_ofragments += nfrags;
1198
1199         /* set first marker for fragment chain */
1200         m0->m_flags |= M_FIRSTFRAG | M_FRAG;
1201         m0->m_pkthdr.csum_data = nfrags;
1202
1203         /*
1204          * Update first fragment by trimming what's been copied out
1205          * and updating header.
1206          */
1207         m_adj(m0, hlen + firstlen - ip->ip_len);
1208         m0->m_pkthdr.len = hlen + firstlen;
1209         ip->ip_len = htons((u_short)m0->m_pkthdr.len);
1210         ip->ip_off |= IP_MF;
1211         ip->ip_off = htons(ip->ip_off);
1212         ip->ip_sum = 0;
1213         if (sw_csum & CSUM_DELAY_IP)
1214                 ip->ip_sum = in_cksum(m0, hlen);
1215
1216 done:
1217         *m_frag = m0;
1218         return error;
1219 }
1220
1221 void
1222 in_delayed_cksum(struct mbuf *m)
1223 {
1224         struct ip *ip;
1225         u_short csum, offset;
1226
1227         ip = mtod(m, struct ip *);
1228         offset = IP_VHL_HL(ip->ip_vhl) << 2 ;
1229         csum = in_cksum_skip(m, ip->ip_len, offset);
1230         if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0)
1231                 csum = 0xffff;
1232         offset += m->m_pkthdr.csum_data;        /* checksum offset */
1233
1234         if (offset + sizeof(u_short) > m->m_len) {
1235                 kprintf("delayed m_pullup, m->len: %d  off: %d  p: %d\n",
1236                     m->m_len, offset, ip->ip_p);
1237                 /*
1238                  * XXX
1239                  * this shouldn't happen, but if it does, the
1240                  * correct behavior may be to insert the checksum
1241                  * in the existing chain instead of rearranging it.
1242                  */
1243                 m = m_pullup(m, offset + sizeof(u_short));
1244         }
1245         *(u_short *)(m->m_data + offset) = csum;
1246 }
1247
1248 /*
1249  * Insert IP options into preformed packet.
1250  * Adjust IP destination as required for IP source routing,
1251  * as indicated by a non-zero in_addr at the start of the options.
1252  *
1253  * XXX This routine assumes that the packet has no options in place.
1254  */
1255 static struct mbuf *
1256 ip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phlen)
1257 {
1258         struct ipoption *p = mtod(opt, struct ipoption *);
1259         struct mbuf *n;
1260         struct ip *ip = mtod(m, struct ip *);
1261         unsigned optlen;
1262
1263         optlen = opt->m_len - sizeof p->ipopt_dst;
1264         if (optlen + (u_short)ip->ip_len > IP_MAXPACKET) {
1265                 *phlen = 0;
1266                 return (m);             /* XXX should fail */
1267         }
1268         if (p->ipopt_dst.s_addr)
1269                 ip->ip_dst = p->ipopt_dst;
1270         if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) {
1271                 MGETHDR(n, MB_DONTWAIT, MT_HEADER);
1272                 if (n == NULL) {
1273                         *phlen = 0;
1274                         return (m);
1275                 }
1276                 n->m_pkthdr.rcvif = (struct ifnet *)NULL;
1277                 n->m_pkthdr.len = m->m_pkthdr.len + optlen;
1278                 m->m_len -= sizeof(struct ip);
1279                 m->m_data += sizeof(struct ip);
1280                 n->m_next = m;
1281                 m = n;
1282                 m->m_len = optlen + sizeof(struct ip);
1283                 m->m_data += max_linkhdr;
1284                 memcpy(mtod(m, void *), ip, sizeof(struct ip));
1285         } else {
1286                 m->m_data -= optlen;
1287                 m->m_len += optlen;
1288                 m->m_pkthdr.len += optlen;
1289                 ovbcopy(ip, mtod(m, caddr_t), sizeof(struct ip));
1290         }
1291         ip = mtod(m, struct ip *);
1292         bcopy(p->ipopt_list, ip + 1, optlen);
1293         *phlen = sizeof(struct ip) + optlen;
1294         ip->ip_vhl = IP_MAKE_VHL(IPVERSION, *phlen >> 2);
1295         ip->ip_len += optlen;
1296         return (m);
1297 }
1298
1299 /*
1300  * Copy options from ip to jp,
1301  * omitting those not copied during fragmentation.
1302  */
1303 int
1304 ip_optcopy(struct ip *ip, struct ip *jp)
1305 {
1306         u_char *cp, *dp;
1307         int opt, optlen, cnt;
1308
1309         cp = (u_char *)(ip + 1);
1310         dp = (u_char *)(jp + 1);
1311         cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip);
1312         for (; cnt > 0; cnt -= optlen, cp += optlen) {
1313                 opt = cp[0];
1314                 if (opt == IPOPT_EOL)
1315                         break;
1316                 if (opt == IPOPT_NOP) {
1317                         /* Preserve for IP mcast tunnel's LSRR alignment. */
1318                         *dp++ = IPOPT_NOP;
1319                         optlen = 1;
1320                         continue;
1321                 }
1322
1323                 KASSERT(cnt >= IPOPT_OLEN + sizeof *cp,
1324                     ("ip_optcopy: malformed ipv4 option"));
1325                 optlen = cp[IPOPT_OLEN];
1326                 KASSERT(optlen >= IPOPT_OLEN + sizeof *cp && optlen <= cnt,
1327                     ("ip_optcopy: malformed ipv4 option"));
1328
1329                 /* bogus lengths should have been caught by ip_dooptions */
1330                 if (optlen > cnt)
1331                         optlen = cnt;
1332                 if (IPOPT_COPIED(opt)) {
1333                         bcopy(cp, dp, optlen);
1334                         dp += optlen;
1335                 }
1336         }
1337         for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++)
1338                 *dp++ = IPOPT_EOL;
1339         return (optlen);
1340 }
1341
1342 /*
1343  * IP socket option processing.
1344  */
1345 int
1346 ip_ctloutput(struct socket *so, struct sockopt *sopt)
1347 {
1348         struct  inpcb *inp = so->so_pcb;
1349         int     error, optval;
1350
1351         error = optval = 0;
1352         if (sopt->sopt_level != IPPROTO_IP) {
1353                 return (EINVAL);
1354         }
1355
1356         switch (sopt->sopt_dir) {
1357         case SOPT_SET:
1358                 switch (sopt->sopt_name) {
1359                 case IP_OPTIONS:
1360 #ifdef notyet
1361                 case IP_RETOPTS:
1362 #endif
1363                 {
1364                         struct mbuf *m;
1365                         if (sopt->sopt_valsize > MLEN) {
1366                                 error = EMSGSIZE;
1367                                 break;
1368                         }
1369                         MGET(m, sopt->sopt_td ? MB_WAIT : MB_DONTWAIT, MT_HEADER);
1370                         if (m == NULL) {
1371                                 error = ENOBUFS;
1372                                 break;
1373                         }
1374                         m->m_len = sopt->sopt_valsize;
1375                         error = soopt_to_kbuf(sopt, mtod(m, void *), m->m_len,
1376                                               m->m_len);
1377                         return (ip_pcbopts(sopt->sopt_name, &inp->inp_options,
1378                                            m));
1379                 }
1380
1381                 case IP_TOS:
1382                 case IP_TTL:
1383                 case IP_MINTTL:
1384                 case IP_RECVOPTS:
1385                 case IP_RECVRETOPTS:
1386                 case IP_RECVDSTADDR:
1387                 case IP_RECVIF:
1388                 case IP_RECVTTL:
1389                 case IP_FAITH:
1390                         error = soopt_to_kbuf(sopt, &optval, sizeof optval,
1391                                              sizeof optval);
1392                         if (error)
1393                                 break;
1394                         switch (sopt->sopt_name) {
1395                         case IP_TOS:
1396                                 inp->inp_ip_tos = optval;
1397                                 break;
1398
1399                         case IP_TTL:
1400                                 inp->inp_ip_ttl = optval;
1401                                 break;
1402                         case IP_MINTTL:
1403                                 if (optval > 0 && optval <= MAXTTL)
1404                                         inp->inp_ip_minttl = optval;
1405                                 else
1406                                         error = EINVAL;
1407                                 break;
1408 #define OPTSET(bit) \
1409         if (optval) \
1410                 inp->inp_flags |= bit; \
1411         else \
1412                 inp->inp_flags &= ~bit;
1413
1414                         case IP_RECVOPTS:
1415                                 OPTSET(INP_RECVOPTS);
1416                                 break;
1417
1418                         case IP_RECVRETOPTS:
1419                                 OPTSET(INP_RECVRETOPTS);
1420                                 break;
1421
1422                         case IP_RECVDSTADDR:
1423                                 OPTSET(INP_RECVDSTADDR);
1424                                 break;
1425
1426                         case IP_RECVIF:
1427                                 OPTSET(INP_RECVIF);
1428                                 break;
1429
1430                         case IP_RECVTTL:
1431                                 OPTSET(INP_RECVTTL);
1432                                 break;
1433
1434                         case IP_FAITH:
1435                                 OPTSET(INP_FAITH);
1436                                 break;
1437                         }
1438                         break;
1439 #undef OPTSET
1440
1441                 case IP_MULTICAST_IF:
1442                 case IP_MULTICAST_VIF:
1443                 case IP_MULTICAST_TTL:
1444                 case IP_MULTICAST_LOOP:
1445                 case IP_ADD_MEMBERSHIP:
1446                 case IP_DROP_MEMBERSHIP:
1447                         error = ip_setmoptions(sopt, &inp->inp_moptions);
1448                         break;
1449
1450                 case IP_PORTRANGE:
1451                         error = soopt_to_kbuf(sopt, &optval, sizeof optval,
1452                                             sizeof optval);
1453                         if (error)
1454                                 break;
1455
1456                         switch (optval) {
1457                         case IP_PORTRANGE_DEFAULT:
1458                                 inp->inp_flags &= ~(INP_LOWPORT);
1459                                 inp->inp_flags &= ~(INP_HIGHPORT);
1460                                 break;
1461
1462                         case IP_PORTRANGE_HIGH:
1463                                 inp->inp_flags &= ~(INP_LOWPORT);
1464                                 inp->inp_flags |= INP_HIGHPORT;
1465                                 break;
1466
1467                         case IP_PORTRANGE_LOW:
1468                                 inp->inp_flags &= ~(INP_HIGHPORT);
1469                                 inp->inp_flags |= INP_LOWPORT;
1470                                 break;
1471
1472                         default:
1473                                 error = EINVAL;
1474                                 break;
1475                         }
1476                         break;
1477
1478 #if defined(IPSEC) || defined(FAST_IPSEC)
1479                 case IP_IPSEC_POLICY:
1480                 {
1481                         caddr_t req;
1482                         size_t len = 0;
1483                         int priv;
1484                         struct mbuf *m;
1485                         int optname;
1486
1487                         if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1488                                 break;
1489                         soopt_to_mbuf(sopt, m);
1490                         priv = (sopt->sopt_td != NULL &&
1491                                 suser(sopt->sopt_td) != 0) ? 0 : 1;
1492                         req = mtod(m, caddr_t);
1493                         len = m->m_len;
1494                         optname = sopt->sopt_name;
1495                         error = ipsec4_set_policy(inp, optname, req, len, priv);
1496                         m_freem(m);
1497                         break;
1498                 }
1499 #endif /*IPSEC*/
1500
1501                 default:
1502                         error = ENOPROTOOPT;
1503                         break;
1504                 }
1505                 break;
1506
1507         case SOPT_GET:
1508                 switch (sopt->sopt_name) {
1509                 case IP_OPTIONS:
1510                 case IP_RETOPTS:
1511                         if (inp->inp_options)
1512                                 soopt_from_kbuf(sopt, mtod(inp->inp_options,
1513                                                            char *),
1514                                                 inp->inp_options->m_len);
1515                         else
1516                                 sopt->sopt_valsize = 0;
1517                         break;
1518
1519                 case IP_TOS:
1520                 case IP_TTL:
1521                 case IP_MINTTL:
1522                 case IP_RECVOPTS:
1523                 case IP_RECVRETOPTS:
1524                 case IP_RECVDSTADDR:
1525                 case IP_RECVTTL:
1526                 case IP_RECVIF:
1527                 case IP_PORTRANGE:
1528                 case IP_FAITH:
1529                         switch (sopt->sopt_name) {
1530
1531                         case IP_TOS:
1532                                 optval = inp->inp_ip_tos;
1533                                 break;
1534
1535                         case IP_TTL:
1536                                 optval = inp->inp_ip_ttl;
1537                                 break;
1538                         case IP_MINTTL:
1539                                 optval = inp->inp_ip_minttl;
1540                                 break;
1541
1542 #define OPTBIT(bit)     (inp->inp_flags & bit ? 1 : 0)
1543
1544                         case IP_RECVOPTS:
1545                                 optval = OPTBIT(INP_RECVOPTS);
1546                                 break;
1547
1548                         case IP_RECVRETOPTS:
1549                                 optval = OPTBIT(INP_RECVRETOPTS);
1550                                 break;
1551
1552                         case IP_RECVDSTADDR:
1553                                 optval = OPTBIT(INP_RECVDSTADDR);
1554                                 break;
1555
1556                         case IP_RECVTTL:
1557                                 optval = OPTBIT(INP_RECVTTL);
1558                                 break;
1559
1560                         case IP_RECVIF:
1561                                 optval = OPTBIT(INP_RECVIF);
1562                                 break;
1563
1564                         case IP_PORTRANGE:
1565                                 if (inp->inp_flags & INP_HIGHPORT)
1566                                         optval = IP_PORTRANGE_HIGH;
1567                                 else if (inp->inp_flags & INP_LOWPORT)
1568                                         optval = IP_PORTRANGE_LOW;
1569                                 else
1570                                         optval = 0;
1571                                 break;
1572
1573                         case IP_FAITH:
1574                                 optval = OPTBIT(INP_FAITH);
1575                                 break;
1576                         }
1577                         soopt_from_kbuf(sopt, &optval, sizeof optval);
1578                         break;
1579
1580                 case IP_MULTICAST_IF:
1581                 case IP_MULTICAST_VIF:
1582                 case IP_MULTICAST_TTL:
1583                 case IP_MULTICAST_LOOP:
1584                 case IP_ADD_MEMBERSHIP:
1585                 case IP_DROP_MEMBERSHIP:
1586                         error = ip_getmoptions(sopt, inp->inp_moptions);
1587                         break;
1588
1589 #if defined(IPSEC) || defined(FAST_IPSEC)
1590                 case IP_IPSEC_POLICY:
1591                 {
1592                         struct mbuf *m = NULL;
1593                         caddr_t req = NULL;
1594                         size_t len = 0;
1595
1596                         if (m != NULL) {
1597                                 req = mtod(m, caddr_t);
1598                                 len = m->m_len;
1599                         }
1600                         error = ipsec4_get_policy(so->so_pcb, req, len, &m);
1601                         if (error == 0)
1602                                 error = soopt_from_mbuf(sopt, m); /* XXX */
1603                         if (error == 0)
1604                                 m_freem(m);
1605                         break;
1606                 }
1607 #endif /*IPSEC*/
1608
1609                 default:
1610                         error = ENOPROTOOPT;
1611                         break;
1612                 }
1613                 break;
1614         }
1615         return (error);
1616 }
1617
1618 /*
1619  * Set up IP options in pcb for insertion in output packets.
1620  * Store in mbuf with pointer in pcbopt, adding pseudo-option
1621  * with destination address if source routed.
1622  */
1623 static int
1624 ip_pcbopts(int optname, struct mbuf **pcbopt, struct mbuf *m)
1625 {
1626         int cnt, optlen;
1627         u_char *cp;
1628         u_char opt;
1629
1630         /* turn off any old options */
1631         if (*pcbopt)
1632                 m_free(*pcbopt);
1633         *pcbopt = 0;
1634         if (m == NULL || m->m_len == 0) {
1635                 /*
1636                  * Only turning off any previous options.
1637                  */
1638                 if (m != NULL)
1639                         m_free(m);
1640                 return (0);
1641         }
1642
1643         if (m->m_len % sizeof(int32_t))
1644                 goto bad;
1645         /*
1646          * IP first-hop destination address will be stored before
1647          * actual options; move other options back
1648          * and clear it when none present.
1649          */
1650         if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN])
1651                 goto bad;
1652         cnt = m->m_len;
1653         m->m_len += sizeof(struct in_addr);
1654         cp = mtod(m, u_char *) + sizeof(struct in_addr);
1655         ovbcopy(mtod(m, caddr_t), cp, cnt);
1656         bzero(mtod(m, caddr_t), sizeof(struct in_addr));
1657
1658         for (; cnt > 0; cnt -= optlen, cp += optlen) {
1659                 opt = cp[IPOPT_OPTVAL];
1660                 if (opt == IPOPT_EOL)
1661                         break;
1662                 if (opt == IPOPT_NOP)
1663                         optlen = 1;
1664                 else {
1665                         if (cnt < IPOPT_OLEN + sizeof *cp)
1666                                 goto bad;
1667                         optlen = cp[IPOPT_OLEN];
1668                         if (optlen < IPOPT_OLEN + sizeof *cp || optlen > cnt)
1669                                 goto bad;
1670                 }
1671                 switch (opt) {
1672
1673                 default:
1674                         break;
1675
1676                 case IPOPT_LSRR:
1677                 case IPOPT_SSRR:
1678                         /*
1679                          * user process specifies route as:
1680                          *      ->A->B->C->D
1681                          * D must be our final destination (but we can't
1682                          * check that since we may not have connected yet).
1683                          * A is first hop destination, which doesn't appear in
1684                          * actual IP option, but is stored before the options.
1685                          */
1686                         if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr))
1687                                 goto bad;
1688                         m->m_len -= sizeof(struct in_addr);
1689                         cnt -= sizeof(struct in_addr);
1690                         optlen -= sizeof(struct in_addr);
1691                         cp[IPOPT_OLEN] = optlen;
1692                         /*
1693                          * Move first hop before start of options.
1694                          */
1695                         bcopy(&cp[IPOPT_OFFSET+1], mtod(m, caddr_t),
1696                               sizeof(struct in_addr));
1697                         /*
1698                          * Then copy rest of options back
1699                          * to close up the deleted entry.
1700                          */
1701                         ovbcopy(&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr),
1702                                 &cp[IPOPT_OFFSET+1],
1703                                 cnt - (IPOPT_MINOFF - 1));
1704                         break;
1705                 }
1706         }
1707         if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr))
1708                 goto bad;
1709         *pcbopt = m;
1710         return (0);
1711
1712 bad:
1713         m_free(m);
1714         return (EINVAL);
1715 }
1716
1717 /*
1718  * XXX
1719  * The whole multicast option thing needs to be re-thought.
1720  * Several of these options are equally applicable to non-multicast
1721  * transmission, and one (IP_MULTICAST_TTL) totally duplicates a
1722  * standard option (IP_TTL).
1723  */
1724
1725 /*
1726  * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index.
1727  */
1728 static struct ifnet *
1729 ip_multicast_if(struct in_addr *a, int *ifindexp)
1730 {
1731         int ifindex;
1732         struct ifnet *ifp;
1733
1734         if (ifindexp)
1735                 *ifindexp = 0;
1736         if (ntohl(a->s_addr) >> 24 == 0) {
1737                 ifindex = ntohl(a->s_addr) & 0xffffff;
1738                 if (ifindex < 0 || if_index < ifindex)
1739                         return NULL;
1740                 ifp = ifindex2ifnet[ifindex];
1741                 if (ifindexp)
1742                         *ifindexp = ifindex;
1743         } else {
1744                 ifp = INADDR_TO_IFP(a);
1745         }
1746         return ifp;
1747 }
1748
1749 /*
1750  * Set the IP multicast options in response to user setsockopt().
1751  */
1752 static int
1753 ip_setmoptions(struct sockopt *sopt, struct ip_moptions **imop)
1754 {
1755         int error = 0;
1756         int i;
1757         struct in_addr addr;
1758         struct ip_mreq mreq;
1759         struct ifnet *ifp;
1760         struct ip_moptions *imo = *imop;
1761         int ifindex;
1762
1763         if (imo == NULL) {
1764                 /*
1765                  * No multicast option buffer attached to the pcb;
1766                  * allocate one and initialize to default values.
1767                  */
1768                 imo = kmalloc(sizeof *imo, M_IPMOPTS, M_WAITOK);
1769
1770                 *imop = imo;
1771                 imo->imo_multicast_ifp = NULL;
1772                 imo->imo_multicast_addr.s_addr = INADDR_ANY;
1773                 imo->imo_multicast_vif = -1;
1774                 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL;
1775                 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP;
1776                 imo->imo_num_memberships = 0;
1777         }
1778         switch (sopt->sopt_name) {
1779         /* store an index number for the vif you wanna use in the send */
1780         case IP_MULTICAST_VIF:
1781                 if (legal_vif_num == 0) {
1782                         error = EOPNOTSUPP;
1783                         break;
1784                 }
1785                 error = soopt_to_kbuf(sopt, &i, sizeof i, sizeof i);
1786                 if (error)
1787                         break;
1788                 if (!legal_vif_num(i) && (i != -1)) {
1789                         error = EINVAL;
1790                         break;
1791                 }
1792                 imo->imo_multicast_vif = i;
1793                 break;
1794
1795         case IP_MULTICAST_IF:
1796                 /*
1797                  * Select the interface for outgoing multicast packets.
1798                  */
1799                 error = soopt_to_kbuf(sopt, &addr, sizeof addr, sizeof addr);
1800                 if (error)
1801                         break;
1802
1803                 /*
1804                  * INADDR_ANY is used to remove a previous selection.
1805                  * When no interface is selected, a default one is
1806                  * chosen every time a multicast packet is sent.
1807                  */
1808                 if (addr.s_addr == INADDR_ANY) {
1809                         imo->imo_multicast_ifp = NULL;
1810                         break;
1811                 }
1812                 /*
1813                  * The selected interface is identified by its local
1814                  * IP address.  Find the interface and confirm that
1815                  * it supports multicasting.
1816                  */
1817                 crit_enter();
1818                 ifp = ip_multicast_if(&addr, &ifindex);
1819                 if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) {
1820                         crit_exit();
1821                         error = EADDRNOTAVAIL;
1822                         break;
1823                 }
1824                 imo->imo_multicast_ifp = ifp;
1825                 if (ifindex)
1826                         imo->imo_multicast_addr = addr;
1827                 else
1828                         imo->imo_multicast_addr.s_addr = INADDR_ANY;
1829                 crit_exit();
1830                 break;
1831
1832         case IP_MULTICAST_TTL:
1833                 /*
1834                  * Set the IP time-to-live for outgoing multicast packets.
1835                  * The original multicast API required a char argument,
1836                  * which is inconsistent with the rest of the socket API.
1837                  * We allow either a char or an int.
1838                  */
1839                 if (sopt->sopt_valsize == 1) {
1840                         u_char ttl;
1841                         error = soopt_to_kbuf(sopt, &ttl, 1, 1);
1842                         if (error)
1843                                 break;
1844                         imo->imo_multicast_ttl = ttl;
1845                 } else {
1846                         u_int ttl;
1847                         error = soopt_to_kbuf(sopt, &ttl, sizeof ttl, sizeof ttl);
1848                         if (error)
1849                                 break;
1850                         if (ttl > 255)
1851                                 error = EINVAL;
1852                         else
1853                                 imo->imo_multicast_ttl = ttl;
1854                 }
1855                 break;
1856
1857         case IP_MULTICAST_LOOP:
1858                 /*
1859                  * Set the loopback flag for outgoing multicast packets.
1860                  * Must be zero or one.  The original multicast API required a
1861                  * char argument, which is inconsistent with the rest
1862                  * of the socket API.  We allow either a char or an int.
1863                  */
1864                 if (sopt->sopt_valsize == 1) {
1865                         u_char loop;
1866
1867                         error = soopt_to_kbuf(sopt, &loop, 1, 1);
1868                         if (error)
1869                                 break;
1870                         imo->imo_multicast_loop = !!loop;
1871                 } else {
1872                         u_int loop;
1873
1874                         error = soopt_to_kbuf(sopt, &loop, sizeof loop,
1875                                             sizeof loop);
1876                         if (error)
1877                                 break;
1878                         imo->imo_multicast_loop = !!loop;
1879                 }
1880                 break;
1881
1882         case IP_ADD_MEMBERSHIP:
1883                 /*
1884                  * Add a multicast group membership.
1885                  * Group must be a valid IP multicast address.
1886                  */
1887                 error = soopt_to_kbuf(sopt, &mreq, sizeof mreq, sizeof mreq);
1888                 if (error)
1889                         break;
1890
1891                 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) {
1892                         error = EINVAL;
1893                         break;
1894                 }
1895                 crit_enter();
1896                 /*
1897                  * If no interface address was provided, use the interface of
1898                  * the route to the given multicast address.
1899                  */
1900                 if (mreq.imr_interface.s_addr == INADDR_ANY) {
1901                         struct sockaddr_in dst;
1902                         struct rtentry *rt;
1903
1904                         bzero(&dst, sizeof(struct sockaddr_in));
1905                         dst.sin_len = sizeof(struct sockaddr_in);
1906                         dst.sin_family = AF_INET;
1907                         dst.sin_addr = mreq.imr_multiaddr;
1908                         rt = rtlookup((struct sockaddr *)&dst);
1909                         if (rt == NULL) {
1910                                 error = EADDRNOTAVAIL;
1911                                 crit_exit();
1912                                 break;
1913                         }
1914                         --rt->rt_refcnt;
1915                         ifp = rt->rt_ifp;
1916                 } else {
1917                         ifp = ip_multicast_if(&mreq.imr_interface, NULL);
1918                 }
1919
1920                 /*
1921                  * See if we found an interface, and confirm that it
1922                  * supports multicast.
1923                  */
1924                 if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) {
1925                         error = EADDRNOTAVAIL;
1926                         crit_exit();
1927                         break;
1928                 }
1929                 /*
1930                  * See if the membership already exists or if all the
1931                  * membership slots are full.
1932                  */
1933                 for (i = 0; i < imo->imo_num_memberships; ++i) {
1934                         if (imo->imo_membership[i]->inm_ifp == ifp &&
1935                             imo->imo_membership[i]->inm_addr.s_addr
1936                                                 == mreq.imr_multiaddr.s_addr)
1937                                 break;
1938                 }
1939                 if (i < imo->imo_num_memberships) {
1940                         error = EADDRINUSE;
1941                         crit_exit();
1942                         break;
1943                 }
1944                 if (i == IP_MAX_MEMBERSHIPS) {
1945                         error = ETOOMANYREFS;
1946                         crit_exit();
1947                         break;
1948                 }
1949                 /*
1950                  * Everything looks good; add a new record to the multicast
1951                  * address list for the given interface.
1952                  */
1953                 if ((imo->imo_membership[i] =
1954                      in_addmulti(&mreq.imr_multiaddr, ifp)) == NULL) {
1955                         error = ENOBUFS;
1956                         crit_exit();
1957                         break;
1958                 }
1959                 ++imo->imo_num_memberships;
1960                 crit_exit();
1961                 break;
1962
1963         case IP_DROP_MEMBERSHIP:
1964                 /*
1965                  * Drop a multicast group membership.
1966                  * Group must be a valid IP multicast address.
1967                  */
1968                 error = soopt_to_kbuf(sopt, &mreq, sizeof mreq, sizeof mreq);
1969                 if (error)
1970                         break;
1971
1972                 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) {
1973                         error = EINVAL;
1974                         break;
1975                 }
1976
1977                 crit_enter();
1978                 /*
1979                  * If an interface address was specified, get a pointer
1980                  * to its ifnet structure.
1981                  */
1982                 if (mreq.imr_interface.s_addr == INADDR_ANY)
1983                         ifp = NULL;
1984                 else {
1985                         ifp = ip_multicast_if(&mreq.imr_interface, NULL);
1986                         if (ifp == NULL) {
1987                                 error = EADDRNOTAVAIL;
1988                                 crit_exit();
1989                                 break;
1990                         }
1991                 }
1992                 /*
1993                  * Find the membership in the membership array.
1994                  */
1995                 for (i = 0; i < imo->imo_num_memberships; ++i) {
1996                         if ((ifp == NULL ||
1997                              imo->imo_membership[i]->inm_ifp == ifp) &&
1998                             imo->imo_membership[i]->inm_addr.s_addr ==
1999                             mreq.imr_multiaddr.s_addr)
2000                                 break;
2001                 }
2002                 if (i == imo->imo_num_memberships) {
2003                         error = EADDRNOTAVAIL;
2004                         crit_exit();
2005                         break;
2006                 }
2007                 /*
2008                  * Give up the multicast address record to which the
2009                  * membership points.
2010                  */
2011                 in_delmulti(imo->imo_membership[i]);
2012                 /*
2013                  * Remove the gap in the membership array.
2014                  */
2015                 for (++i; i < imo->imo_num_memberships; ++i)
2016                         imo->imo_membership[i-1] = imo->imo_membership[i];
2017                 --imo->imo_num_memberships;
2018                 crit_exit();
2019                 break;
2020
2021         default:
2022                 error = EOPNOTSUPP;
2023                 break;
2024         }
2025
2026         /*
2027          * If all options have default values, no need to keep the mbuf.
2028          */
2029         if (imo->imo_multicast_ifp == NULL &&
2030             imo->imo_multicast_vif == -1 &&
2031             imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL &&
2032             imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP &&
2033             imo->imo_num_memberships == 0) {
2034                 kfree(*imop, M_IPMOPTS);
2035                 *imop = NULL;
2036         }
2037
2038         return (error);
2039 }
2040
2041 /*
2042  * Return the IP multicast options in response to user getsockopt().
2043  */
2044 static int
2045 ip_getmoptions(struct sockopt *sopt, struct ip_moptions *imo)
2046 {
2047         struct in_addr addr;
2048         struct in_ifaddr *ia;
2049         int error, optval;
2050         u_char coptval;
2051
2052         error = 0;
2053         switch (sopt->sopt_name) {
2054         case IP_MULTICAST_VIF:
2055                 if (imo != NULL)
2056                         optval = imo->imo_multicast_vif;
2057                 else
2058                         optval = -1;
2059                 soopt_from_kbuf(sopt, &optval, sizeof optval);
2060                 break;
2061
2062         case IP_MULTICAST_IF:
2063                 if (imo == NULL || imo->imo_multicast_ifp == NULL)
2064                         addr.s_addr = INADDR_ANY;
2065                 else if (imo->imo_multicast_addr.s_addr) {
2066                         /* return the value user has set */
2067                         addr = imo->imo_multicast_addr;
2068                 } else {
2069                         ia = IFP_TO_IA(imo->imo_multicast_ifp);
2070                         addr.s_addr = (ia == NULL) ? INADDR_ANY
2071                                 : IA_SIN(ia)->sin_addr.s_addr;
2072                 }
2073                 soopt_from_kbuf(sopt, &addr, sizeof addr);
2074                 break;
2075
2076         case IP_MULTICAST_TTL:
2077                 if (imo == NULL)
2078                         optval = coptval = IP_DEFAULT_MULTICAST_TTL;
2079                 else
2080                         optval = coptval = imo->imo_multicast_ttl;
2081                 if (sopt->sopt_valsize == 1)
2082                         soopt_from_kbuf(sopt, &coptval, 1);
2083                 else
2084                         soopt_from_kbuf(sopt, &optval, sizeof optval);
2085                 break;
2086
2087         case IP_MULTICAST_LOOP:
2088                 if (imo == NULL)
2089                         optval = coptval = IP_DEFAULT_MULTICAST_LOOP;
2090                 else
2091                         optval = coptval = imo->imo_multicast_loop;
2092                 if (sopt->sopt_valsize == 1)
2093                         soopt_from_kbuf(sopt, &coptval, 1);
2094                 else
2095                         soopt_from_kbuf(sopt, &optval, sizeof optval);
2096                 break;
2097
2098         default:
2099                 error = ENOPROTOOPT;
2100                 break;
2101         }
2102         return (error);
2103 }
2104
2105 /*
2106  * Discard the IP multicast options.
2107  */
2108 void
2109 ip_freemoptions(struct ip_moptions *imo)
2110 {
2111         int i;
2112
2113         if (imo != NULL) {
2114                 for (i = 0; i < imo->imo_num_memberships; ++i)
2115                         in_delmulti(imo->imo_membership[i]);
2116                 kfree(imo, M_IPMOPTS);
2117         }
2118 }
2119
2120 /*
2121  * Routine called from ip_output() to loop back a copy of an IP multicast
2122  * packet to the input queue of a specified interface.  Note that this
2123  * calls the output routine of the loopback "driver", but with an interface
2124  * pointer that might NOT be a loopback interface -- evil, but easier than
2125  * replicating that code here.
2126  */
2127 static void
2128 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst,
2129              int hlen)
2130 {
2131         struct ip *ip;
2132         struct mbuf *copym;
2133
2134         copym = m_copypacket(m, MB_DONTWAIT);
2135         if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen))
2136                 copym = m_pullup(copym, hlen);
2137         if (copym != NULL) {
2138                 /*
2139                  * if the checksum hasn't been computed, mark it as valid
2140                  */
2141                 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
2142                         in_delayed_cksum(copym);
2143                         copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
2144                         copym->m_pkthdr.csum_flags |=
2145                             CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
2146                         copym->m_pkthdr.csum_data = 0xffff;
2147                 }
2148                 /*
2149                  * We don't bother to fragment if the IP length is greater
2150                  * than the interface's MTU.  Can this possibly matter?
2151                  */
2152                 ip = mtod(copym, struct ip *);
2153                 ip->ip_len = htons(ip->ip_len);
2154                 ip->ip_off = htons(ip->ip_off);
2155                 ip->ip_sum = 0;
2156                 if (ip->ip_vhl == IP_VHL_BORING) {
2157                         ip->ip_sum = in_cksum_hdr(ip);
2158                 } else {
2159                         ip->ip_sum = in_cksum(copym, hlen);
2160                 }
2161                 /*
2162                  * NB:
2163                  * It's not clear whether there are any lingering
2164                  * reentrancy problems in other areas which might
2165                  * be exposed by using ip_input directly (in
2166                  * particular, everything which modifies the packet
2167                  * in-place).  Yet another option is using the
2168                  * protosw directly to deliver the looped back
2169                  * packet.  For the moment, we'll err on the side
2170                  * of safety by using if_simloop().
2171                  */
2172 #if 1 /* XXX */
2173                 if (dst->sin_family != AF_INET) {
2174                         kprintf("ip_mloopback: bad address family %d\n",
2175                                                 dst->sin_family);
2176                         dst->sin_family = AF_INET;
2177                 }
2178 #endif
2179                 if_simloop(ifp, copym, dst->sin_family, 0);
2180         }
2181 }