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  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  *      @(#)ip_output.c 8.3 (Berkeley) 1/21/94
  30  * $FreeBSD$
  31  */
  32
  33 #include "opt_ipfw.h"
  34 #include "opt_ipsec.h"
  35 #include "opt_mac.h"
  36 #include "opt_mbuf_stress_test.h"
  37
  38 #include <sys/param.h>
  39 #include <sys/systm.h>
  40 #include <sys/kernel.h>
  41 #include <sys/malloc.h>
  42 #include <sys/mbuf.h>
  43 #include <sys/priv.h>
  44 #include <sys/protosw.h>
  45 #include <sys/socket.h>
  46 #include <sys/socketvar.h>
  47 #include <sys/sysctl.h>
  48
  49 #include <net/if.h>
  50 #include <net/netisr.h>
  51 #include <net/pfil.h>
  52 #include <net/route.h>
  53
  54 #include <netinet/in.h>
  55 #include <netinet/in_systm.h>
  56 #include <netinet/ip.h>
  57 #include <netinet/in_pcb.h>
  58 #include <netinet/in_var.h>
  59 #include <netinet/ip_var.h>
  60 #include <netinet/ip_options.h>
  61
  62 #if defined(IPSEC) || defined(FAST_IPSEC)
  63 #include <netinet/ip_ipsec.h>
  64 #ifdef IPSEC
  65 #include <netinet6/ipsec.h>
  66 #endif
  67 #ifdef FAST_IPSEC
  68 #include <netipsec/ipsec.h>
  69 #endif
  70 #endif /*IPSEC*/
  71
  72 #include <machine/in_cksum.h>
  73
  74 #include <security/mac/mac_framework.h>
  75
  76 static MALLOC_DEFINE(M_IPMOPTS, "ip_moptions", "internet multicast options");
  77
  78 #define print_ip(x, a, y)        printf("%s %d.%d.%d.%d%s",\
  79                                 x, (ntohl(a.s_addr)>>24)&0xFF,\
  80                                   (ntohl(a.s_addr)>>16)&0xFF,\
  81                                   (ntohl(a.s_addr)>>8)&0xFF,\
  82                                   (ntohl(a.s_addr))&0xFF, y);
  83
  84 u_short ip_id;
  85
  86 #ifdef MBUF_STRESS_TEST
  87 int mbuf_frag_size = 0;
  88 SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW,
  89         &mbuf_frag_size, 0, "Fragment outgoing mbufs to this size");
  90 #endif
  91
  92 static struct ifnet *ip_multicast_if(struct in_addr *, int *);
  93 static void     ip_mloopback
  94         (struct ifnet *, struct mbuf *, struct sockaddr_in *, int);
  95 static int      ip_getmoptions(struct inpcb *, struct sockopt *);
  96 static int      ip_setmoptions(struct inpcb *, struct sockopt *);
  97
  98
  99 extern  struct protosw inetsw[];
 100
 101 /*
 102  * IP output.  The packet in mbuf chain m contains a skeletal IP
 103  * header (with len, off, ttl, proto, tos, src, dst).
 104  * The mbuf chain containing the packet will be freed.
 105  * The mbuf opt, if present, will not be freed.
 106  * In the IP forwarding case, the packet will arrive with options already
 107  * inserted, so must have a NULL opt pointer.
 108  */
 109 int
 110 ip_output(struct mbuf *m, struct mbuf *opt, struct route *ro,
 111         int flags, struct ip_moptions *imo, struct inpcb *inp)
 112 {
 113         struct ip *ip;
 114         struct ifnet *ifp = NULL;       /* keep compiler happy */
 115         struct mbuf *m0;
 116         int hlen = sizeof (struct ip);
 117         int mtu;
 118         int len, error = 0;
 119         struct sockaddr_in *dst = NULL; /* keep compiler happy */
 120         struct in_ifaddr *ia = NULL;
 121         int isbroadcast, sw_csum;
 122         struct route iproute;
 123         struct in_addr odst;
 124 #ifdef IPFIREWALL_FORWARD
 125         struct m_tag *fwd_tag = NULL;
 126 #endif
 127         M_ASSERTPKTHDR(m);
 128
 129         if (ro == NULL) {
 130                 ro = &iproute;
 131                 bzero(ro, sizeof (*ro));
 132         }
 133
 134         if (inp != NULL)
 135                 INP_LOCK_ASSERT(inp);
 136
 137         if (opt) {
 138                 len = 0;
 139                 m = ip_insertoptions(m, opt, &len);
 140                 if (len != 0)
 141                         hlen = len;
 142         }
 143         ip = mtod(m, struct ip *);
 144
 145         /*
 146          * Fill in IP header.  If we are not allowing fragmentation,
 147          * then the ip_id field is meaningless, but we don't set it
 148          * to zero.  Doing so causes various problems when devices along
 149          * the path (routers, load balancers, firewalls, etc.) illegally
 150          * disable DF on our packet.  Note that a 16-bit counter
 151          * will wrap around in less than 10 seconds at 100 Mbit/s on a
 152          * medium with MTU 1500.  See Steven M. Bellovin, "A Technique
 153          * for Counting NATted Hosts", Proc. IMW'02, available at
 154          * <http://www.cs.columbia.edu/~smb/papers/fnat.pdf>.
 155          */
 156         if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) {
 157                 ip->ip_v = IPVERSION;
 158                 ip->ip_hl = hlen >> 2;
 159                 ip->ip_id = ip_newid();
 160                 ipstat.ips_localout++;
 161         } else {
 162                 hlen = ip->ip_hl << 2;
 163         }
 164
 165         dst = (struct sockaddr_in *)&ro->ro_dst;
 166 again:
 167         /*
 168          * If there is a cached route,
 169          * check that it is to the same destination
 170          * and is still up.  If not, free it and try again.
 171          * The address family should also be checked in case of sharing the
 172          * cache with IPv6.
 173          */
 174         if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 ||
 175                           dst->sin_family != AF_INET ||
 176                           dst->sin_addr.s_addr != ip->ip_dst.s_addr)) {
 177                 RTFREE(ro->ro_rt);
 178                 ro->ro_rt = (struct rtentry *)NULL;
 179         }
 180 #ifdef IPFIREWALL_FORWARD
 181         if (ro->ro_rt == NULL && fwd_tag == NULL) {
 182 #else
 183         if (ro->ro_rt == NULL) {
 184 #endif
 185                 bzero(dst, sizeof(*dst));
 186                 dst->sin_family = AF_INET;
 187                 dst->sin_len = sizeof(*dst);
 188                 dst->sin_addr = ip->ip_dst;
 189         }
 190         /*
 191          * If routing to interface only, short circuit routing lookup.
 192          * The use of an all-ones broadcast address implies this; an
 193          * interface is specified by the broadcast address of an interface,
 194          * or the destination address of a ptp interface.
 195          */
 196         if (flags & IP_SENDONES) {
 197                 if ((ia = ifatoia(ifa_ifwithbroadaddr(sintosa(dst)))) == NULL &&
 198                     (ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL) {
 199                         ipstat.ips_noroute++;
 200                         error = ENETUNREACH;
 201                         goto bad;
 202                 }
 203                 ip->ip_dst.s_addr = INADDR_BROADCAST;
 204                 dst->sin_addr = ip->ip_dst;
 205                 ifp = ia->ia_ifp;
 206                 ip->ip_ttl = 1;
 207                 isbroadcast = 1;
 208         } else if (flags & IP_ROUTETOIF) {
 209                 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL &&
 210                     (ia = ifatoia(ifa_ifwithnet(sintosa(dst)))) == NULL) {
 211                         ipstat.ips_noroute++;
 212                         error = ENETUNREACH;
 213                         goto bad;
 214                 }
 215                 ifp = ia->ia_ifp;
 216                 ip->ip_ttl = 1;
 217                 isbroadcast = in_broadcast(dst->sin_addr, ifp);
 218         } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
 219             imo != NULL && imo->imo_multicast_ifp != NULL) {
 220                 /*
 221                  * Bypass the normal routing lookup for multicast
 222                  * packets if the interface is specified.
 223                  */
 224                 ifp = imo->imo_multicast_ifp;
 225                 IFP_TO_IA(ifp, ia);
 226                 isbroadcast = 0;        /* fool gcc */
 227         } else {
 228                 /*
 229                  * We want to do any cloning requested by the link layer,
 230                  * as this is probably required in all cases for correct
 231                  * operation (as it is for ARP).
 232                  */
 233                 if (ro->ro_rt == NULL)
 234                         rtalloc_ign(ro, 0);
 235                 if (ro->ro_rt == NULL) {
 236                         ipstat.ips_noroute++;
 237                         error = EHOSTUNREACH;
 238                         goto bad;
 239                 }
 240                 ia = ifatoia(ro->ro_rt->rt_ifa);
 241                 ifp = ro->ro_rt->rt_ifp;
 242                 ro->ro_rt->rt_rmx.rmx_pksent++;
 243                 if (ro->ro_rt->rt_flags & RTF_GATEWAY)
 244                         dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway;
 245                 if (ro->ro_rt->rt_flags & RTF_HOST)
 246                         isbroadcast = (ro->ro_rt->rt_flags & RTF_BROADCAST);
 247                 else
 248                         isbroadcast = in_broadcast(dst->sin_addr, ifp);
 249         }
 250         /*
 251          * Calculate MTU.  If we have a route that is up, use that,
 252          * otherwise use the interface's MTU.
 253          */
 254         if (ro->ro_rt != NULL && (ro->ro_rt->rt_flags & (RTF_UP|RTF_HOST))) {
 255                 /*
 256                  * This case can happen if the user changed the MTU
 257                  * of an interface after enabling IP on it.  Because
 258                  * most netifs don't keep track of routes pointing to
 259                  * them, there is no way for one to update all its
 260                  * routes when the MTU is changed.
 261                  */
 262                 if (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)
 263                         ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu;
 264                 mtu = ro->ro_rt->rt_rmx.rmx_mtu;
 265         } else {
 266                 mtu = ifp->if_mtu;
 267         }
 268         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
 269                 struct in_multi *inm;
 270
 271                 m->m_flags |= M_MCAST;
 272                 /*
 273                  * IP destination address is multicast.  Make sure "dst"
 274                  * still points to the address in "ro".  (It may have been
 275                  * changed to point to a gateway address, above.)
 276                  */
 277                 dst = (struct sockaddr_in *)&ro->ro_dst;
 278                 /*
 279                  * See if the caller provided any multicast options
 280                  */
 281                 if (imo != NULL) {
 282                         ip->ip_ttl = imo->imo_multicast_ttl;
 283                         if (imo->imo_multicast_vif != -1)
 284                                 ip->ip_src.s_addr =
 285                                     ip_mcast_src ?
 286                                     ip_mcast_src(imo->imo_multicast_vif) :
 287                                     INADDR_ANY;
 288                 } else
 289                         ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL;
 290                 /*
 291                  * Confirm that the outgoing interface supports multicast.
 292                  */
 293                 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) {
 294                         if ((ifp->if_flags & IFF_MULTICAST) == 0) {
 295                                 ipstat.ips_noroute++;
 296                                 error = ENETUNREACH;
 297                                 goto bad;
 298                         }
 299                 }
 300                 /*
 301                  * If source address not specified yet, use address
 302                  * of outgoing interface.
 303                  */
 304                 if (ip->ip_src.s_addr == INADDR_ANY) {
 305                         /* Interface may have no addresses. */
 306                         if (ia != NULL)
 307                                 ip->ip_src = IA_SIN(ia)->sin_addr;
 308                 }
 309
 310                 IN_MULTI_LOCK();
 311                 IN_LOOKUP_MULTI(ip->ip_dst, ifp, inm);
 312                 if (inm != NULL &&
 313                    (imo == NULL || imo->imo_multicast_loop)) {
 314                         IN_MULTI_UNLOCK();
 315                         /*
 316                          * If we belong to the destination multicast group
 317                          * on the outgoing interface, and the caller did not
 318                          * forbid loopback, loop back a copy.
 319                          */
 320                         ip_mloopback(ifp, m, dst, hlen);
 321                 }
 322                 else {
 323                         IN_MULTI_UNLOCK();
 324                         /*
 325                          * If we are acting as a multicast router, perform
 326                          * multicast forwarding as if the packet had just
 327                          * arrived on the interface to which we are about
 328                          * to send.  The multicast forwarding function
 329                          * recursively calls this function, using the
 330                          * IP_FORWARDING flag to prevent infinite recursion.
 331                          *
 332                          * Multicasts that are looped back by ip_mloopback(),
 333                          * above, will be forwarded by the ip_input() routine,
 334                          * if necessary.
 335                          */
 336                         if (ip_mrouter && (flags & IP_FORWARDING) == 0) {
 337                                 /*
 338                                  * If rsvp daemon is not running, do not
 339                                  * set ip_moptions. This ensures that the packet
 340                                  * is multicast and not just sent down one link
 341                                  * as prescribed by rsvpd.
 342                                  */
 343                                 if (!rsvp_on)
 344                                         imo = NULL;
 345                                 if (ip_mforward &&
 346                                     ip_mforward(ip, ifp, m, imo) != 0) {
 347                                         m_freem(m);
 348                                         goto done;
 349                                 }
 350                         }
 351                 }
 352
 353                 /*
 354                  * Multicasts with a time-to-live of zero may be looped-
 355                  * back, above, but must not be transmitted on a network.
 356                  * Also, multicasts addressed to the loopback interface
 357                  * are not sent -- the above call to ip_mloopback() will
 358                  * loop back a copy if this host actually belongs to the
 359                  * destination group on the loopback interface.
 360                  */
 361                 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) {
 362                         m_freem(m);
 363                         goto done;
 364                 }
 365
 366                 goto sendit;
 367         }
 368
 369         /*
 370          * If the source address is not specified yet, use the address
 371          * of the outoing interface.
 372          */
 373         if (ip->ip_src.s_addr == INADDR_ANY) {
 374                 /* Interface may have no addresses. */
 375                 if (ia != NULL) {
 376                         ip->ip_src = IA_SIN(ia)->sin_addr;
 377                 }
 378         }
 379
 380         /*
 381          * Verify that we have any chance at all of being able to queue the
 382          * packet or packet fragments, unless ALTQ is enabled on the given
 383          * interface in which case packetdrop should be done by queueing.
 384          */
 385 #ifdef ALTQ
 386         if ((!ALTQ_IS_ENABLED(&ifp->if_snd)) &&
 387             ((ifp->if_snd.ifq_len + ip->ip_len / mtu + 1) >=
 388             ifp->if_snd.ifq_maxlen))
 389 #else
 390         if ((ifp->if_snd.ifq_len + ip->ip_len / mtu + 1) >=
 391             ifp->if_snd.ifq_maxlen)
 392 #endif /* ALTQ */
 393         {
 394                 error = ENOBUFS;
 395                 ipstat.ips_odropped++;
 396                 ifp->if_snd.ifq_drops += (ip->ip_len / ifp->if_mtu + 1);
 397                 goto bad;
 398         }
 399
 400         /*
 401          * Look for broadcast address and
 402          * verify user is allowed to send
 403          * such a packet.
 404          */
 405         if (isbroadcast) {
 406                 if ((ifp->if_flags & IFF_BROADCAST) == 0) {
 407                         error = EADDRNOTAVAIL;
 408                         goto bad;
 409                 }
 410                 if ((flags & IP_ALLOWBROADCAST) == 0) {
 411                         error = EACCES;
 412                         goto bad;
 413                 }
 414                 /* don't allow broadcast messages to be fragmented */
 415                 if (ip->ip_len > mtu) {
 416                         error = EMSGSIZE;
 417                         goto bad;
 418                 }
 419                 m->m_flags |= M_BCAST;
 420         } else {
 421                 m->m_flags &= ~M_BCAST;
 422         }
 423
 424 sendit:
 425 #if defined(IPSEC) || defined(FAST_IPSEC)
 426         switch(ip_ipsec_output(&m, inp, &flags, &error, &ro, &iproute, &dst, &ia, &ifp)) {
 427         case 1:
 428                 goto bad;
 429         case -1:
 430                 goto done;
 431         case 0:
 432         default:
 433                 break;  /* Continue with packet processing. */
 434         }
 435         /* Update variables that are affected by ipsec4_output(). */
 436         ip = mtod(m, struct ip *);
 437         hlen = ip->ip_hl << 2;
 438 #endif /* IPSEC */
 439
 440         /* Jump over all PFIL processing if hooks are not active. */
 441         if (!PFIL_HOOKED(&inet_pfil_hook))
 442                 goto passout;
 443
 444         /* Run through list of hooks for output packets. */
 445         odst.s_addr = ip->ip_dst.s_addr;
 446         error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, PFIL_OUT, inp);
 447         if (error != 0 || m == NULL)
 448                 goto done;
 449
 450         ip = mtod(m, struct ip *);
 451
 452         /* See if destination IP address was changed by packet filter. */
 453         if (odst.s_addr != ip->ip_dst.s_addr) {
 454                 m->m_flags |= M_SKIP_FIREWALL;
 455                 /* If destination is now ourself drop to ip_input(). */
 456                 if (in_localip(ip->ip_dst)) {
 457                         m->m_flags |= M_FASTFWD_OURS;
 458                         if (m->m_pkthdr.rcvif == NULL)
 459                                 m->m_pkthdr.rcvif = loif;
 460                         if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
 461                                 m->m_pkthdr.csum_flags |=
 462                                     CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
 463                                 m->m_pkthdr.csum_data = 0xffff;
 464                         }
 465                         m->m_pkthdr.csum_flags |=
 466                             CSUM_IP_CHECKED | CSUM_IP_VALID;
 467
 468                         error = netisr_queue(NETISR_IP, m);
 469                         goto done;
 470                 } else
 471                         goto again;     /* Redo the routing table lookup. */
 472         }
 473
 474 #ifdef IPFIREWALL_FORWARD
 475         /* See if local, if yes, send it to netisr with IP_FASTFWD_OURS. */
 476         if (m->m_flags & M_FASTFWD_OURS) {
 477                 if (m->m_pkthdr.rcvif == NULL)
 478                         m->m_pkthdr.rcvif = loif;
 479                 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
 480                         m->m_pkthdr.csum_flags |=
 481                             CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
 482                         m->m_pkthdr.csum_data = 0xffff;
 483                 }
 484                 m->m_pkthdr.csum_flags |=
 485                             CSUM_IP_CHECKED | CSUM_IP_VALID;
 486
 487                 error = netisr_queue(NETISR_IP, m);
 488                 goto done;
 489         }
 490         /* Or forward to some other address? */
 491         fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
 492         if (fwd_tag) {
 493                 dst = (struct sockaddr_in *)&ro->ro_dst;
 494                 bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in));
 495                 m->m_flags |= M_SKIP_FIREWALL;
 496                 m_tag_delete(m, fwd_tag);
 497                 goto again;
 498         }
 499 #endif /* IPFIREWALL_FORWARD */
 500
 501 passout:
 502         /* 127/8 must not appear on wire - RFC1122. */
 503         if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
 504             (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
 505                 if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
 506                         ipstat.ips_badaddr++;
 507                         error = EADDRNOTAVAIL;
 508                         goto bad;
 509                 }
 510         }
 511
 512         m->m_pkthdr.csum_flags |= CSUM_IP;
 513         sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist;
 514         if (sw_csum & CSUM_DELAY_DATA) {
 515                 in_delayed_cksum(m);
 516                 sw_csum &= ~CSUM_DELAY_DATA;
 517         }
 518         m->m_pkthdr.csum_flags &= ifp->if_hwassist;
 519
 520         /*
 521          * If small enough for interface, or the interface will take
 522          * care of the fragmentation for us, we can just send directly.
 523          */
 524         if (ip->ip_len <= mtu ||
 525             (m->m_pkthdr.csum_flags & ifp->if_hwassist & CSUM_TSO) != 0 ||
 526             ((ip->ip_off & IP_DF) == 0 && (ifp->if_hwassist & CSUM_FRAGMENT))) {
 527                 ip->ip_len = htons(ip->ip_len);
 528                 ip->ip_off = htons(ip->ip_off);
 529                 ip->ip_sum = 0;
 530                 if (sw_csum & CSUM_DELAY_IP)
 531                         ip->ip_sum = in_cksum(m, hlen);
 532
 533                 /*
 534                  * Record statistics for this interface address.
 535                  * With CSUM_TSO the byte/packet count will be slightly
 536                  * incorrect because we count the IP+TCP headers only
 537                  * once instead of for every generated packet.
 538                  */
 539                 if (!(flags & IP_FORWARDING) && ia) {
 540                         if (m->m_pkthdr.csum_flags & CSUM_TSO)
 541                                 ia->ia_ifa.if_opackets +=
 542                                     m->m_pkthdr.len / m->m_pkthdr.tso_segsz;
 543                         else
 544                                 ia->ia_ifa.if_opackets++;
 545                         ia->ia_ifa.if_obytes += m->m_pkthdr.len;
 546                 }
 547 #ifdef IPSEC
 548                 /* clean ipsec history once it goes out of the node */
 549                 ipsec_delaux(m);
 550 #endif
 551 #ifdef MBUF_STRESS_TEST
 552                 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size)
 553                         m = m_fragment(m, M_DONTWAIT, mbuf_frag_size);
 554 #endif
 555                 /*
 556                  * Reset layer specific mbuf flags
 557                  * to avoid confusing lower layers.
 558                  */
 559                 m->m_flags &= ~(M_PROTOFLAGS);
 560
 561                 error = (*ifp->if_output)(ifp, m,
 562                                 (struct sockaddr *)dst, ro->ro_rt);
 563                 goto done;
 564         }
 565
 566         /* Balk when DF bit is set or the interface didn't support TSO. */
 567         if ((ip->ip_off & IP_DF) || (m->m_pkthdr.csum_flags & CSUM_TSO)) {
 568                 error = EMSGSIZE;
 569                 ipstat.ips_cantfrag++;
 570                 goto bad;
 571         }
 572
 573         /*
 574          * Too large for interface; fragment if possible. If successful,
 575          * on return, m will point to a list of packets to be sent.
 576          */
 577         error = ip_fragment(ip, &m, mtu, ifp->if_hwassist, sw_csum);
 578         if (error)
 579                 goto bad;
 580         for (; m; m = m0) {
 581                 m0 = m->m_nextpkt;
 582                 m->m_nextpkt = 0;
 583 #ifdef IPSEC
 584                 /* clean ipsec history once it goes out of the node */
 585                 ipsec_delaux(m);
 586 #endif
 587                 if (error == 0) {
 588                         /* Record statistics for this interface address. */
 589                         if (ia != NULL) {
 590                                 ia->ia_ifa.if_opackets++;
 591                                 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
 592                         }
 593                         /*
 594                          * Reset layer specific mbuf flags
 595                          * to avoid confusing upper layers.
 596                          */
 597                         m->m_flags &= ~(M_PROTOFLAGS);
 598
 599                         error = (*ifp->if_output)(ifp, m,
 600                             (struct sockaddr *)dst, ro->ro_rt);
 601                 } else
 602                         m_freem(m);
 603         }
 604
 605         if (error == 0)
 606                 ipstat.ips_fragmented++;
 607
 608 done:
 609         if (ro == &iproute && ro->ro_rt) {
 610                 RTFREE(ro->ro_rt);
 611         }
 612         return (error);
 613 bad:
 614         m_freem(m);
 615         goto done;
 616 }
 617
 618 /*
 619  * Create a chain of fragments which fit the given mtu. m_frag points to the
 620  * mbuf to be fragmented; on return it points to the chain with the fragments.
 621  * Return 0 if no error. If error, m_frag may contain a partially built
 622  * chain of fragments that should be freed by the caller.
 623  *
 624  * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist)
 625  * sw_csum contains the delayed checksums flags (e.g., CSUM_DELAY_IP).
 626  */
 627 int
 628 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
 629             u_long if_hwassist_flags, int sw_csum)
 630 {
 631         int error = 0;
 632         int hlen = ip->ip_hl << 2;
 633         int len = (mtu - hlen) & ~7;    /* size of payload in each fragment */
 634         int off;
 635         struct mbuf *m0 = *m_frag;      /* the original packet          */
 636         int firstlen;
 637         struct mbuf **mnext;
 638         int nfrags;
 639
 640         if (ip->ip_off & IP_DF) {       /* Fragmentation not allowed */
 641                 ipstat.ips_cantfrag++;
 642                 return EMSGSIZE;
 643         }
 644
 645         /*
 646          * Must be able to put at least 8 bytes per fragment.
 647          */
 648         if (len < 8)
 649                 return EMSGSIZE;
 650
 651         /*
 652          * If the interface will not calculate checksums on
 653          * fragmented packets, then do it here.
 654          */
 655         if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA &&
 656             (if_hwassist_flags & CSUM_IP_FRAGS) == 0) {
 657                 in_delayed_cksum(m0);
 658                 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
 659         }
 660
 661         if (len > PAGE_SIZE) {
 662                 /*
 663                  * Fragment large datagrams such that each segment
 664                  * contains a multiple of PAGE_SIZE amount of data,
 665                  * plus headers. This enables a receiver to perform
 666                  * page-flipping zero-copy optimizations.
 667                  *
 668                  * XXX When does this help given that sender and receiver
 669                  * could have different page sizes, and also mtu could
 670                  * be less than the receiver's page size ?
 671                  */
 672                 int newlen;
 673                 struct mbuf *m;
 674
 675                 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next)
 676                         off += m->m_len;
 677
 678                 /*
 679                  * firstlen (off - hlen) must be aligned on an
 680                  * 8-byte boundary
 681                  */
 682                 if (off < hlen)
 683                         goto smart_frag_failure;
 684                 off = ((off - hlen) & ~7) + hlen;
 685                 newlen = (~PAGE_MASK) & mtu;
 686                 if ((newlen + sizeof (struct ip)) > mtu) {
 687                         /* we failed, go back the default */
 688 smart_frag_failure:
 689                         newlen = len;
 690                         off = hlen + len;
 691                 }
 692                 len = newlen;
 693
 694         } else {
 695                 off = hlen + len;
 696         }
 697
 698         firstlen = off - hlen;
 699         mnext = &m0->m_nextpkt;         /* pointer to next packet */
 700
 701         /*
 702          * Loop through length of segment after first fragment,
 703          * make new header and copy data of each part and link onto chain.
 704          * Here, m0 is the original packet, m is the fragment being created.
 705          * The fragments are linked off the m_nextpkt of the original
 706          * packet, which after processing serves as the first fragment.
 707          */
 708         for (nfrags = 1; off < ip->ip_len; off += len, nfrags++) {
 709                 struct ip *mhip;        /* ip header on the fragment */
 710                 struct mbuf *m;
 711                 int mhlen = sizeof (struct ip);
 712
 713                 MGETHDR(m, M_DONTWAIT, MT_DATA);
 714                 if (m == NULL) {
 715                         error = ENOBUFS;
 716                         ipstat.ips_odropped++;
 717                         goto done;
 718                 }
 719                 m->m_flags |= (m0->m_flags & M_MCAST) | M_FRAG;
 720                 /*
 721                  * In the first mbuf, leave room for the link header, then
 722                  * copy the original IP header including options. The payload
 723                  * goes into an additional mbuf chain returned by m_copy().
 724                  */
 725                 m->m_data += max_linkhdr;
 726                 mhip = mtod(m, struct ip *);
 727                 *mhip = *ip;
 728                 if (hlen > sizeof (struct ip)) {
 729                         mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
 730                         mhip->ip_v = IPVERSION;
 731                         mhip->ip_hl = mhlen >> 2;
 732                 }
 733                 m->m_len = mhlen;
 734                 /* XXX do we need to add ip->ip_off below ? */
 735                 mhip->ip_off = ((off - hlen) >> 3) + ip->ip_off;
 736                 if (off + len >= ip->ip_len) {  /* last fragment */
 737                         len = ip->ip_len - off;
 738                         m->m_flags |= M_LASTFRAG;
 739                 } else
 740                         mhip->ip_off |= IP_MF;
 741                 mhip->ip_len = htons((u_short)(len + mhlen));
 742                 m->m_next = m_copy(m0, off, len);
 743                 if (m->m_next == NULL) {        /* copy failed */
 744                         m_free(m);
 745                         error = ENOBUFS;        /* ??? */
 746                         ipstat.ips_odropped++;
 747                         goto done;
 748                 }
 749                 m->m_pkthdr.len = mhlen + len;
 750                 m->m_pkthdr.rcvif = NULL;
 751 #ifdef MAC
 752                 mac_create_fragment(m0, m);
 753 #endif
 754                 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags;
 755                 mhip->ip_off = htons(mhip->ip_off);
 756                 mhip->ip_sum = 0;
 757                 if (sw_csum & CSUM_DELAY_IP)
 758                         mhip->ip_sum = in_cksum(m, mhlen);
 759                 *mnext = m;
 760                 mnext = &m->m_nextpkt;
 761         }
 762         ipstat.ips_ofragments += nfrags;
 763
 764         /* set first marker for fragment chain */
 765         m0->m_flags |= M_FIRSTFRAG | M_FRAG;
 766         m0->m_pkthdr.csum_data = nfrags;
 767
 768         /*
 769          * Update first fragment by trimming what's been copied out
 770          * and updating header.
 771          */
 772         m_adj(m0, hlen + firstlen - ip->ip_len);
 773         m0->m_pkthdr.len = hlen + firstlen;
 774         ip->ip_len = htons((u_short)m0->m_pkthdr.len);
 775         ip->ip_off |= IP_MF;
 776         ip->ip_off = htons(ip->ip_off);
 777         ip->ip_sum = 0;
 778         if (sw_csum & CSUM_DELAY_IP)
 779                 ip->ip_sum = in_cksum(m0, hlen);
 780
 781 done:
 782         *m_frag = m0;
 783         return error;
 784 }
 785
 786 void
 787 in_delayed_cksum(struct mbuf *m)
 788 {
 789         struct ip *ip;
 790         u_short csum, offset;
 791
 792         ip = mtod(m, struct ip *);
 793         offset = ip->ip_hl << 2 ;
 794         csum = in_cksum_skip(m, ip->ip_len, offset);
 795         if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0)
 796                 csum = 0xffff;
 797         offset += m->m_pkthdr.csum_data;        /* checksum offset */
 798
 799         if (offset + sizeof(u_short) > m->m_len) {
 800                 printf("delayed m_pullup, m->len: %d  off: %d  p: %d\n",
 801                     m->m_len, offset, ip->ip_p);
 802                 /*
 803                  * XXX
 804                  * this shouldn't happen, but if it does, the
 805                  * correct behavior may be to insert the checksum
 806                  * in the appropriate next mbuf in the chain.
 807                  */
 808                 return;
 809         }
 810         *(u_short *)(m->m_data + offset) = csum;
 811 }
 812
 813 /*
 814  * IP socket option processing.
 815  */
 816 int
 817 ip_ctloutput(so, sopt)
 818         struct socket *so;
 819         struct sockopt *sopt;
 820 {
 821         struct  inpcb *inp = sotoinpcb(so);
 822         int     error, optval;
 823
 824         error = optval = 0;
 825         if (sopt->sopt_level != IPPROTO_IP) {
 826                 return (EINVAL);
 827         }
 828
 829         switch (sopt->sopt_dir) {
 830         case SOPT_SET:
 831                 switch (sopt->sopt_name) {
 832                 case IP_OPTIONS:
 833 #ifdef notyet
 834                 case IP_RETOPTS:
 835 #endif
 836                 {
 837                         struct mbuf *m;
 838                         if (sopt->sopt_valsize > MLEN) {
 839                                 error = EMSGSIZE;
 840                                 break;
 841                         }
 842                         MGET(m, sopt->sopt_td ? M_TRYWAIT : M_DONTWAIT, MT_DATA);
 843                         if (m == NULL) {
 844                                 error = ENOBUFS;
 845                                 break;
 846                         }
 847                         m->m_len = sopt->sopt_valsize;
 848                         error = sooptcopyin(sopt, mtod(m, char *), m->m_len,
 849                                             m->m_len);
 850                         if (error) {
 851                                 m_free(m);
 852                                 break;
 853                         }
 854                         INP_LOCK(inp);
 855                         error = ip_pcbopts(inp, sopt->sopt_name, m);
 856                         INP_UNLOCK(inp);
 857                         return (error);
 858                 }
 859
 860                 case IP_TOS:
 861                 case IP_TTL:
 862                 case IP_MINTTL:
 863                 case IP_RECVOPTS:
 864                 case IP_RECVRETOPTS:
 865                 case IP_RECVDSTADDR:
 866                 case IP_RECVTTL:
 867                 case IP_RECVIF:
 868                 case IP_FAITH:
 869                 case IP_ONESBCAST:
 870                 case IP_DONTFRAG:
 871                         error = sooptcopyin(sopt, &optval, sizeof optval,
 872                                             sizeof optval);
 873                         if (error)
 874                                 break;
 875
 876                         switch (sopt->sopt_name) {
 877                         case IP_TOS:
 878                                 inp->inp_ip_tos = optval;
 879                                 break;
 880
 881                         case IP_TTL:
 882                                 inp->inp_ip_ttl = optval;
 883                                 break;
 884
 885                         case IP_MINTTL:
 886                                 if (optval > 0 && optval <= MAXTTL)
 887                                         inp->inp_ip_minttl = optval;
 888                                 else
 889                                         error = EINVAL;
 890                                 break;
 891
 892 #define OPTSET(bit) do {                                                \
 893         INP_LOCK(inp);                                                  \
 894         if (optval)                                                     \
 895                 inp->inp_flags |= bit;                                  \
 896         else                                                            \
 897                 inp->inp_flags &= ~bit;                                 \
 898         INP_UNLOCK(inp);                                                \
 899 } while (0)
 900
 901                         case IP_RECVOPTS:
 902                                 OPTSET(INP_RECVOPTS);
 903                                 break;
 904
 905                         case IP_RECVRETOPTS:
 906                                 OPTSET(INP_RECVRETOPTS);
 907                                 break;
 908
 909                         case IP_RECVDSTADDR:
 910                                 OPTSET(INP_RECVDSTADDR);
 911                                 break;
 912
 913                         case IP_RECVTTL:
 914                                 OPTSET(INP_RECVTTL);
 915                                 break;
 916
 917                         case IP_RECVIF:
 918                                 OPTSET(INP_RECVIF);
 919                                 break;
 920
 921                         case IP_FAITH:
 922                                 OPTSET(INP_FAITH);
 923                                 break;
 924
 925                         case IP_ONESBCAST:
 926                                 OPTSET(INP_ONESBCAST);
 927                                 break;
 928                         case IP_DONTFRAG:
 929                                 OPTSET(INP_DONTFRAG);
 930                                 break;
 931                         }
 932                         break;
 933 #undef OPTSET
 934
 935                 case IP_MULTICAST_IF:
 936                 case IP_MULTICAST_VIF:
 937                 case IP_MULTICAST_TTL:
 938                 case IP_MULTICAST_LOOP:
 939                 case IP_ADD_MEMBERSHIP:
 940                 case IP_DROP_MEMBERSHIP:
 941                         error = ip_setmoptions(inp, sopt);
 942                         break;
 943
 944                 case IP_PORTRANGE:
 945                         error = sooptcopyin(sopt, &optval, sizeof optval,
 946                                             sizeof optval);
 947                         if (error)
 948                                 break;
 949
 950                         INP_LOCK(inp);
 951                         switch (optval) {
 952                         case IP_PORTRANGE_DEFAULT:
 953                                 inp->inp_flags &= ~(INP_LOWPORT);
 954                                 inp->inp_flags &= ~(INP_HIGHPORT);
 955                                 break;
 956
 957                         case IP_PORTRANGE_HIGH:
 958                                 inp->inp_flags &= ~(INP_LOWPORT);
 959                                 inp->inp_flags |= INP_HIGHPORT;
 960                                 break;
 961
 962                         case IP_PORTRANGE_LOW:
 963                                 inp->inp_flags &= ~(INP_HIGHPORT);
 964                                 inp->inp_flags |= INP_LOWPORT;
 965                                 break;
 966
 967                         default:
 968                                 error = EINVAL;
 969                                 break;
 970                         }
 971                         INP_UNLOCK(inp);
 972                         break;
 973
 974 #if defined(IPSEC) || defined(FAST_IPSEC)
 975                 case IP_IPSEC_POLICY:
 976                 {
 977                         caddr_t req;
 978                         size_t len = 0;
 979                         int priv;
 980                         struct mbuf *m;
 981                         int optname;
 982
 983                         if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
 984                                 break;
 985                         if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
 986                                 break;
 987                         if (sopt->sopt_td != NULL) {
 988                                 /*
 989                                  * XXXRW: Would be more desirable to do this
 990                                  * one layer down so that we only exercise
 991                                  * privilege if it is needed.
 992                                  */
 993                                 error = priv_check(sopt->sopt_td,
 994                                     PRIV_NETINET_IPSEC);
 995                                 if (error)
 996                                         priv = 0;
 997                                 else
 998                                         priv = 1;
 999                         } else
1000                                 priv = 1;
1001                         req = mtod(m, caddr_t);
1002                         len = m->m_len;
1003                         optname = sopt->sopt_name;
1004                         error = ipsec4_set_policy(inp, optname, req, len, priv);
1005                         m_freem(m);
1006                         break;
1007                 }
1008 #endif /*IPSEC*/
1009
1010                 default:
1011                         error = ENOPROTOOPT;
1012                         break;
1013                 }
1014                 break;
1015
1016         case SOPT_GET:
1017                 switch (sopt->sopt_name) {
1018                 case IP_OPTIONS:
1019                 case IP_RETOPTS:
1020                         if (inp->inp_options)
1021                                 error = sooptcopyout(sopt,
1022                                                      mtod(inp->inp_options,
1023                                                           char *),
1024                                                      inp->inp_options->m_len);
1025                         else
1026                                 sopt->sopt_valsize = 0;
1027                         break;
1028
1029                 case IP_TOS:
1030                 case IP_TTL:
1031                 case IP_MINTTL:
1032                 case IP_RECVOPTS:
1033                 case IP_RECVRETOPTS:
1034                 case IP_RECVDSTADDR:
1035                 case IP_RECVTTL:
1036                 case IP_RECVIF:
1037                 case IP_PORTRANGE:
1038                 case IP_FAITH:
1039                 case IP_ONESBCAST:
1040                 case IP_DONTFRAG:
1041                         switch (sopt->sopt_name) {
1042
1043                         case IP_TOS:
1044                                 optval = inp->inp_ip_tos;
1045                                 break;
1046
1047                         case IP_TTL:
1048                                 optval = inp->inp_ip_ttl;
1049                                 break;
1050
1051                         case IP_MINTTL:
1052                                 optval = inp->inp_ip_minttl;
1053                                 break;
1054
1055 #define OPTBIT(bit)     (inp->inp_flags & bit ? 1 : 0)
1056
1057                         case IP_RECVOPTS:
1058                                 optval = OPTBIT(INP_RECVOPTS);
1059                                 break;
1060
1061                         case IP_RECVRETOPTS:
1062                                 optval = OPTBIT(INP_RECVRETOPTS);
1063                                 break;
1064
1065                         case IP_RECVDSTADDR:
1066                                 optval = OPTBIT(INP_RECVDSTADDR);
1067                                 break;
1068
1069                         case IP_RECVTTL:
1070                                 optval = OPTBIT(INP_RECVTTL);
1071                                 break;
1072
1073                         case IP_RECVIF:
1074                                 optval = OPTBIT(INP_RECVIF);
1075                                 break;
1076
1077                         case IP_PORTRANGE:
1078                                 if (inp->inp_flags & INP_HIGHPORT)
1079                                         optval = IP_PORTRANGE_HIGH;
1080                                 else if (inp->inp_flags & INP_LOWPORT)
1081                                         optval = IP_PORTRANGE_LOW;
1082                                 else
1083                                         optval = 0;
1084                                 break;
1085
1086                         case IP_FAITH:
1087                                 optval = OPTBIT(INP_FAITH);
1088                                 break;
1089
1090                         case IP_ONESBCAST:
1091                                 optval = OPTBIT(INP_ONESBCAST);
1092                                 break;
1093                         case IP_DONTFRAG:
1094                                 optval = OPTBIT(INP_DONTFRAG);
1095                                 break;
1096                         }
1097                         error = sooptcopyout(sopt, &optval, sizeof optval);
1098                         break;
1099
1100                 case IP_MULTICAST_IF:
1101                 case IP_MULTICAST_VIF:
1102                 case IP_MULTICAST_TTL:
1103                 case IP_MULTICAST_LOOP:
1104                         error = ip_getmoptions(inp, sopt);
1105                         break;
1106
1107 #if defined(IPSEC) || defined(FAST_IPSEC)
1108                 case IP_IPSEC_POLICY:
1109                 {
1110                         struct mbuf *m = NULL;
1111                         caddr_t req = NULL;
1112                         size_t len = 0;
1113
1114                         if (m != 0) {
1115                                 req = mtod(m, caddr_t);
1116                                 len = m->m_len;
1117                         }
1118                         error = ipsec4_get_policy(sotoinpcb(so), req, len, &m);
1119                         if (error == 0)
1120                                 error = soopt_mcopyout(sopt, m); /* XXX */
1121                         if (error == 0)
1122                                 m_freem(m);
1123                         break;
1124                 }
1125 #endif /*IPSEC*/
1126
1127                 default:
1128                         error = ENOPROTOOPT;
1129                         break;
1130                 }
1131                 break;
1132         }
1133         return (error);
1134 }
1135
1136 /*
1137  * XXX
1138  * The whole multicast option thing needs to be re-thought.
1139  * Several of these options are equally applicable to non-multicast
1140  * transmission, and one (IP_MULTICAST_TTL) totally duplicates a
1141  * standard option (IP_TTL).
1142  */
1143
1144 /*
1145  * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index.
1146  */
1147 static struct ifnet *
1148 ip_multicast_if(a, ifindexp)
1149         struct in_addr *a;
1150         int *ifindexp;
1151 {
1152         int ifindex;
1153         struct ifnet *ifp;
1154
1155         if (ifindexp)
1156                 *ifindexp = 0;
1157         if (ntohl(a->s_addr) >> 24 == 0) {
1158                 ifindex = ntohl(a->s_addr) & 0xffffff;
1159                 if (ifindex < 0 || if_index < ifindex)
1160                         return NULL;
1161                 ifp = ifnet_byindex(ifindex);
1162                 if (ifindexp)
1163                         *ifindexp = ifindex;
1164         } else {
1165                 INADDR_TO_IFP(*a, ifp);
1166         }
1167         return ifp;
1168 }
1169
1170 /*
1171  * Given an inpcb, return its multicast options structure pointer.  Accepts
1172  * an unlocked inpcb pointer, but will return it locked.  May sleep.
1173  */
1174 static struct ip_moptions *
1175 ip_findmoptions(struct inpcb *inp)
1176 {
1177         struct ip_moptions *imo;
1178         struct in_multi **immp;
1179
1180         INP_LOCK(inp);
1181         if (inp->inp_moptions != NULL)
1182                 return (inp->inp_moptions);
1183
1184         INP_UNLOCK(inp);
1185
1186         imo = (struct ip_moptions*)malloc(sizeof(*imo), M_IPMOPTS, M_WAITOK);
1187         immp = (struct in_multi **)malloc((sizeof(*immp) * IP_MIN_MEMBERSHIPS),
1188                                           M_IPMOPTS, M_WAITOK);
1189
1190         imo->imo_multicast_ifp = NULL;
1191         imo->imo_multicast_addr.s_addr = INADDR_ANY;
1192         imo->imo_multicast_vif = -1;
1193         imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL;
1194         imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP;
1195         imo->imo_num_memberships = 0;
1196         imo->imo_max_memberships = IP_MIN_MEMBERSHIPS;
1197         imo->imo_membership = immp;
1198
1199         INP_LOCK(inp);
1200         if (inp->inp_moptions != NULL) {
1201                 free(immp, M_IPMOPTS);
1202                 free(imo, M_IPMOPTS);
1203                 return (inp->inp_moptions);
1204         }
1205         inp->inp_moptions = imo;
1206         return (imo);
1207 }
1208
1209 /*
1210  * Set the IP multicast options in response to user setsockopt().
1211  */
1212 static int
1213 ip_setmoptions(struct inpcb *inp, struct sockopt *sopt)
1214 {
1215         int error = 0;
1216         int i;
1217         struct in_addr addr;
1218         struct ip_mreq mreq;
1219         struct ifnet *ifp;
1220         struct ip_moptions *imo;
1221         struct route ro;
1222         struct sockaddr_in *dst;
1223         int ifindex;
1224         int s;
1225
1226         switch (sopt->sopt_name) {
1227         /* store an index number for the vif you wanna use in the send */
1228         case IP_MULTICAST_VIF:
1229                 if (legal_vif_num == 0) {
1230                         error = EOPNOTSUPP;
1231                         break;
1232                 }
1233                 error = sooptcopyin(sopt, &i, sizeof i, sizeof i);
1234                 if (error)
1235                         break;
1236                 if (!legal_vif_num(i) && (i != -1)) {
1237                         error = EINVAL;
1238                         break;
1239                 }
1240                 imo = ip_findmoptions(inp);
1241                 imo->imo_multicast_vif = i;
1242                 INP_UNLOCK(inp);
1243                 break;
1244
1245         case IP_MULTICAST_IF:
1246                 /*
1247                  * Select the interface for outgoing multicast packets.
1248                  */
1249                 error = sooptcopyin(sopt, &addr, sizeof addr, sizeof addr);
1250                 if (error)
1251                         break;
1252                 /*
1253                  * INADDR_ANY is used to remove a previous selection.
1254                  * When no interface is selected, a default one is
1255                  * chosen every time a multicast packet is sent.
1256                  */
1257                 imo = ip_findmoptions(inp);
1258                 if (addr.s_addr == INADDR_ANY) {
1259                         imo->imo_multicast_ifp = NULL;
1260                         INP_UNLOCK(inp);
1261                         break;
1262                 }
1263                 /*
1264                  * The selected interface is identified by its local
1265                  * IP address.  Find the interface and confirm that
1266                  * it supports multicasting.
1267                  */
1268                 s = splimp();
1269                 ifp = ip_multicast_if(&addr, &ifindex);
1270                 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
1271                         INP_UNLOCK(inp);
1272                         splx(s);
1273                         error = EADDRNOTAVAIL;
1274                         break;
1275                 }
1276                 imo->imo_multicast_ifp = ifp;
1277                 if (ifindex)
1278                         imo->imo_multicast_addr = addr;
1279                 else
1280                         imo->imo_multicast_addr.s_addr = INADDR_ANY;
1281                 INP_UNLOCK(inp);
1282                 splx(s);
1283                 break;
1284
1285         case IP_MULTICAST_TTL:
1286                 /*
1287                  * Set the IP time-to-live for outgoing multicast packets.
1288                  * The original multicast API required a char argument,
1289                  * which is inconsistent with the rest of the socket API.
1290                  * We allow either a char or an int.
1291                  */
1292                 if (sopt->sopt_valsize == 1) {
1293                         u_char ttl;
1294                         error = sooptcopyin(sopt, &ttl, 1, 1);
1295                         if (error)
1296                                 break;
1297                         imo = ip_findmoptions(inp);
1298                         imo->imo_multicast_ttl = ttl;
1299                         INP_UNLOCK(inp);
1300                 } else {
1301                         u_int ttl;
1302                         error = sooptcopyin(sopt, &ttl, sizeof ttl,
1303                                             sizeof ttl);
1304                         if (error)
1305                                 break;
1306                         if (ttl > 255)
1307                                 error = EINVAL;
1308                         else {
1309                                 imo = ip_findmoptions(inp);
1310                                 imo->imo_multicast_ttl = ttl;
1311                                 INP_UNLOCK(inp);
1312                         }
1313                 }
1314                 break;
1315
1316         case IP_MULTICAST_LOOP:
1317                 /*
1318                  * Set the loopback flag for outgoing multicast packets.
1319                  * Must be zero or one.  The original multicast API required a
1320                  * char argument, which is inconsistent with the rest
1321                  * of the socket API.  We allow either a char or an int.
1322                  */
1323                 if (sopt->sopt_valsize == 1) {
1324                         u_char loop;
1325                         error = sooptcopyin(sopt, &loop, 1, 1);
1326                         if (error)
1327                                 break;
1328                         imo = ip_findmoptions(inp);
1329                         imo->imo_multicast_loop = !!loop;
1330                         INP_UNLOCK(inp);
1331                 } else {
1332                         u_int loop;
1333                         error = sooptcopyin(sopt, &loop, sizeof loop,
1334                                             sizeof loop);
1335                         if (error)
1336                                 break;
1337                         imo = ip_findmoptions(inp);
1338                         imo->imo_multicast_loop = !!loop;
1339                         INP_UNLOCK(inp);
1340                 }
1341                 break;
1342
1343         case IP_ADD_MEMBERSHIP:
1344                 /*
1345                  * Add a multicast group membership.
1346                  * Group must be a valid IP multicast address.
1347                  */
1348                 error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq);
1349                 if (error)
1350                         break;
1351
1352                 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) {
1353                         error = EINVAL;
1354                         break;
1355                 }
1356                 s = splimp();
1357                 /*
1358                  * If no interface address was provided, use the interface of
1359                  * the route to the given multicast address.
1360                  */
1361                 if (mreq.imr_interface.s_addr == INADDR_ANY) {
1362                         bzero((caddr_t)&ro, sizeof(ro));
1363                         dst = (struct sockaddr_in *)&ro.ro_dst;
1364                         dst->sin_len = sizeof(*dst);
1365                         dst->sin_family = AF_INET;
1366                         dst->sin_addr = mreq.imr_multiaddr;
1367                         rtalloc_ign(&ro, RTF_CLONING);
1368                         if (ro.ro_rt == NULL) {
1369                                 error = EADDRNOTAVAIL;
1370                                 splx(s);
1371                                 break;
1372                         }
1373                         ifp = ro.ro_rt->rt_ifp;
1374                         RTFREE(ro.ro_rt);
1375                 }
1376                 else {
1377                         ifp = ip_multicast_if(&mreq.imr_interface, NULL);
1378                 }
1379
1380                 /*
1381                  * See if we found an interface, and confirm that it
1382                  * supports multicast.
1383                  */
1384                 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
1385                         error = EADDRNOTAVAIL;
1386                         splx(s);
1387                         break;
1388                 }
1389                 /*
1390                  * See if the membership already exists or if all the
1391                  * membership slots are full.
1392                  */
1393                 imo = ip_findmoptions(inp);
1394                 for (i = 0; i < imo->imo_num_memberships; ++i) {
1395                         if (imo->imo_membership[i]->inm_ifp == ifp &&
1396                             imo->imo_membership[i]->inm_addr.s_addr
1397                                                 == mreq.imr_multiaddr.s_addr)
1398                                 break;
1399                 }
1400                 if (i < imo->imo_num_memberships) {
1401                         INP_UNLOCK(inp);
1402                         error = EADDRINUSE;
1403                         splx(s);
1404                         break;
1405                 }
1406                 if (imo->imo_num_memberships == imo->imo_max_memberships) {
1407                     struct in_multi **nmships, **omships;
1408                     size_t newmax;
1409                     /*
1410                      * Resize the vector to next power-of-two minus 1. If the
1411                      * size would exceed the maximum then we know we've really
1412                      * run out of entries. Otherwise, we realloc() the vector
1413                      * with the INP lock held to avoid introducing a race.
1414                      */
1415                     nmships = NULL;
1416                     omships = imo->imo_membership;
1417                     newmax = ((imo->imo_max_memberships + 1) * 2) - 1;
1418                     if (newmax <= IP_MAX_MEMBERSHIPS) {
1419                         nmships = (struct in_multi **)realloc(omships,
1420 sizeof(*nmships) * newmax, M_IPMOPTS, M_NOWAIT);
1421                         if (nmships != NULL) {
1422                             imo->imo_membership = nmships;
1423                             imo->imo_max_memberships = newmax;
1424                         }
1425                     }
1426                     if (nmships == NULL) {
1427                         INP_UNLOCK(inp);
1428                         error = ETOOMANYREFS;
1429                         splx(s);
1430                         break;
1431                     }
1432                 }
1433                 /*
1434                  * Everything looks good; add a new record to the multicast
1435                  * address list for the given interface.
1436                  */
1437                 if ((imo->imo_membership[i] =
1438                     in_addmulti(&mreq.imr_multiaddr, ifp)) == NULL) {
1439                         INP_UNLOCK(inp);
1440                         error = ENOBUFS;
1441                         splx(s);
1442                         break;
1443                 }
1444                 ++imo->imo_num_memberships;
1445                 INP_UNLOCK(inp);
1446                 splx(s);
1447                 break;
1448
1449         case IP_DROP_MEMBERSHIP:
1450                 /*
1451                  * Drop a multicast group membership.
1452                  * Group must be a valid IP multicast address.
1453                  */
1454                 error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq);
1455                 if (error)
1456                         break;
1457
1458                 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) {
1459                         error = EINVAL;
1460                         break;
1461                 }
1462
1463                 s = splimp();
1464                 /*
1465                  * If an interface address was specified, get a pointer
1466                  * to its ifnet structure.
1467                  */
1468                 if (mreq.imr_interface.s_addr == INADDR_ANY)
1469                         ifp = NULL;
1470                 else {
1471                         ifp = ip_multicast_if(&mreq.imr_interface, NULL);
1472                         if (ifp == NULL) {
1473                                 error = EADDRNOTAVAIL;
1474                                 splx(s);
1475                                 break;
1476                         }
1477                 }
1478                 /*
1479                  * Find the membership in the membership array.
1480                  */
1481                 imo = ip_findmoptions(inp);
1482                 for (i = 0; i < imo->imo_num_memberships; ++i) {
1483                         if ((ifp == NULL ||
1484                              imo->imo_membership[i]->inm_ifp == ifp) &&
1485                              imo->imo_membership[i]->inm_addr.s_addr ==
1486                              mreq.imr_multiaddr.s_addr)
1487                                 break;
1488                 }
1489                 if (i == imo->imo_num_memberships) {
1490                         INP_UNLOCK(inp);
1491                         error = EADDRNOTAVAIL;
1492                         splx(s);
1493                         break;
1494                 }
1495                 /*
1496                  * Give up the multicast address record to which the
1497                  * membership points.
1498                  */
1499                 in_delmulti(imo->imo_membership[i]);
1500                 /*
1501                  * Remove the gap in the membership array.
1502                  */
1503                 for (++i; i < imo->imo_num_memberships; ++i)
1504                         imo->imo_membership[i-1] = imo->imo_membership[i];
1505                 --imo->imo_num_memberships;
1506                 INP_UNLOCK(inp);
1507                 splx(s);
1508                 break;
1509
1510         default:
1511                 error = EOPNOTSUPP;
1512                 break;
1513         }
1514
1515         return (error);
1516 }
1517
1518 /*
1519  * Return the IP multicast options in response to user getsockopt().
1520  */
1521 static int
1522 ip_getmoptions(struct inpcb *inp, struct sockopt *sopt)
1523 {
1524         struct ip_moptions *imo;
1525         struct in_addr addr;
1526         struct in_ifaddr *ia;
1527         int error, optval;
1528         u_char coptval;
1529
1530         INP_LOCK(inp);
1531         imo = inp->inp_moptions;
1532
1533         error = 0;
1534         switch (sopt->sopt_name) {
1535         case IP_MULTICAST_VIF:
1536                 if (imo != NULL)
1537                         optval = imo->imo_multicast_vif;
1538                 else
1539                         optval = -1;
1540                 INP_UNLOCK(inp);
1541                 error = sooptcopyout(sopt, &optval, sizeof optval);
1542                 break;
1543
1544         case IP_MULTICAST_IF:
1545                 if (imo == NULL || imo->imo_multicast_ifp == NULL)
1546                         addr.s_addr = INADDR_ANY;
1547                 else if (imo->imo_multicast_addr.s_addr) {
1548                         /* return the value user has set */
1549                         addr = imo->imo_multicast_addr;
1550                 } else {
1551                         IFP_TO_IA(imo->imo_multicast_ifp, ia);
1552                         addr.s_addr = (ia == NULL) ? INADDR_ANY
1553                                 : IA_SIN(ia)->sin_addr.s_addr;
1554                 }
1555                 INP_UNLOCK(inp);
1556                 error = sooptcopyout(sopt, &addr, sizeof addr);
1557                 break;
1558
1559         case IP_MULTICAST_TTL:
1560                 if (imo == 0)
1561                         optval = coptval = IP_DEFAULT_MULTICAST_TTL;
1562                 else
1563                         optval = coptval = imo->imo_multicast_ttl;
1564                 INP_UNLOCK(inp);
1565                 if (sopt->sopt_valsize == 1)
1566                         error = sooptcopyout(sopt, &coptval, 1);
1567                 else
1568                         error = sooptcopyout(sopt, &optval, sizeof optval);
1569                 break;
1570
1571         case IP_MULTICAST_LOOP:
1572                 if (imo == 0)
1573                         optval = coptval = IP_DEFAULT_MULTICAST_LOOP;
1574                 else
1575                         optval = coptval = imo->imo_multicast_loop;
1576                 INP_UNLOCK(inp);
1577                 if (sopt->sopt_valsize == 1)
1578                         error = sooptcopyout(sopt, &coptval, 1);
1579                 else
1580                         error = sooptcopyout(sopt, &optval, sizeof optval);
1581                 break;
1582
1583         default:
1584                 INP_UNLOCK(inp);
1585                 error = ENOPROTOOPT;
1586                 break;
1587         }
1588         INP_UNLOCK_ASSERT(inp);
1589
1590         return (error);
1591 }
1592
1593 /*
1594  * Discard the IP multicast options.
1595  */
1596 void
1597 ip_freemoptions(imo)
1598         register struct ip_moptions *imo;
1599 {
1600         register int i;
1601
1602         if (imo != NULL) {
1603                 for (i = 0; i < imo->imo_num_memberships; ++i)
1604                         in_delmulti(imo->imo_membership[i]);
1605                 free(imo->imo_membership, M_IPMOPTS);
1606                 free(imo, M_IPMOPTS);
1607         }
1608 }
1609
1610 /*
1611  * Routine called from ip_output() to loop back a copy of an IP multicast
1612  * packet to the input queue of a specified interface.  Note that this
1613  * calls the output routine of the loopback "driver", but with an interface
1614  * pointer that might NOT be a loopback interface -- evil, but easier than
1615  * replicating that code here.
1616  */
1617 static void
1618 ip_mloopback(ifp, m, dst, hlen)
1619         struct ifnet *ifp;
1620         register struct mbuf *m;
1621         register struct sockaddr_in *dst;
1622         int hlen;
1623 {
1624         register struct ip *ip;
1625         struct mbuf *copym;
1626
1627         copym = m_copy(m, 0, M_COPYALL);
1628         if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen))
1629                 copym = m_pullup(copym, hlen);
1630         if (copym != NULL) {
1631                 /* If needed, compute the checksum and mark it as valid. */
1632                 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
1633                         in_delayed_cksum(copym);
1634                         copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
1635                         copym->m_pkthdr.csum_flags |=
1636                             CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1637                         copym->m_pkthdr.csum_data = 0xffff;
1638                 }
1639                 /*
1640                  * We don't bother to fragment if the IP length is greater
1641                  * than the interface's MTU.  Can this possibly matter?
1642                  */
1643                 ip = mtod(copym, struct ip *);
1644                 ip->ip_len = htons(ip->ip_len);
1645                 ip->ip_off = htons(ip->ip_off);
1646                 ip->ip_sum = 0;
1647                 ip->ip_sum = in_cksum(copym, hlen);
1648                 /*
1649                  * NB:
1650                  * It's not clear whether there are any lingering
1651                  * reentrancy problems in other areas which might
1652                  * be exposed by using ip_input directly (in
1653                  * particular, everything which modifies the packet
1654                  * in-place).  Yet another option is using the
1655                  * protosw directly to deliver the looped back
1656                  * packet.  For the moment, we'll err on the side
1657                  * of safety by using if_simloop().
1658                  */
1659 #if 1 /* XXX */
1660                 if (dst->sin_family != AF_INET) {
1661                         printf("ip_mloopback: bad address family %d\n",
1662                                                 dst->sin_family);
1663                         dst->sin_family = AF_INET;
1664                 }
1665 #endif
1666
1667 #ifdef notdef
1668                 copym->m_pkthdr.rcvif = ifp;
1669                 ip_input(copym);
1670 #else
1671                 if_simloop(ifp, copym, dst->sin_family, 0);
1672 #endif
1673         }
1674 }