sys/netinet/ip_output.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-3-Clause
   3  *
   4  * Copyright (c) 1982, 1986, 1988, 1990, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  *      @(#)ip_output.c 8.3 (Berkeley) 1/21/94
  32  */
  33
  34 #include <sys/cdefs.h>
  35 __FBSDID("$FreeBSD$");
  36
  37 #include "opt_inet.h"
  38 #include "opt_ipsec.h"
  39 #include "opt_kern_tls.h"
  40 #include "opt_mbuf_stress_test.h"
  41 #include "opt_mpath.h"
  42 #include "opt_ratelimit.h"
  43 #include "opt_route.h"
  44 #include "opt_rss.h"
  45 #include "opt_sctp.h"
  46
  47 #include <sys/param.h>
  48 #include <sys/systm.h>
  49 #include <sys/kernel.h>
  50 #include <sys/ktls.h>
  51 #include <sys/lock.h>
  52 #include <sys/malloc.h>
  53 #include <sys/mbuf.h>
  54 #include <sys/priv.h>
  55 #include <sys/proc.h>
  56 #include <sys/protosw.h>
  57 #include <sys/rmlock.h>
  58 #include <sys/sdt.h>
  59 #include <sys/socket.h>
  60 #include <sys/socketvar.h>
  61 #include <sys/sysctl.h>
  62 #include <sys/ucred.h>
  63
  64 #include <net/if.h>
  65 #include <net/if_var.h>
  66 #include <net/if_llatbl.h>
  67 #include <net/netisr.h>
  68 #include <net/pfil.h>
  69 #include <net/route.h>
  70 #ifdef RADIX_MPATH
  71 #include <net/radix_mpath.h>
  72 #endif
  73 #include <net/rss_config.h>
  74 #include <net/vnet.h>
  75
  76 #include <netinet/in.h>
  77 #include <netinet/in_fib.h>
  78 #include <netinet/in_kdtrace.h>
  79 #include <netinet/in_systm.h>
  80 #include <netinet/ip.h>
  81 #include <netinet/in_pcb.h>
  82 #include <netinet/in_rss.h>
  83 #include <netinet/in_var.h>
  84 #include <netinet/ip_var.h>
  85 #include <netinet/ip_options.h>
  86
  87 #include <netinet/udp.h>
  88 #include <netinet/udp_var.h>
  89
  90 #ifdef SCTP
  91 #include <netinet/sctp.h>
  92 #include <netinet/sctp_crc32.h>
  93 #endif
  94
  95 #include <netipsec/ipsec_support.h>
  96
  97 #include <machine/in_cksum.h>
  98
  99 #include <security/mac/mac_framework.h>
 100
 101 #ifdef MBUF_STRESS_TEST
 102 static 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 void     ip_mloopback(struct ifnet *, const struct mbuf *, int);
 108
 109
 110 extern int in_mcast_loop;
 111 extern  struct protosw inetsw[];
 112
 113 static inline int
 114 ip_output_pfil(struct mbuf **mp, struct ifnet *ifp, int flags,
 115     struct inpcb *inp, struct sockaddr_in *dst, int *fibnum, int *error)
 116 {
 117         struct m_tag *fwd_tag = NULL;
 118         struct mbuf *m;
 119         struct in_addr odst;
 120         struct ip *ip;
 121         int pflags = PFIL_OUT;
 122
 123         if (flags & IP_FORWARDING)
 124                 pflags |= PFIL_FWD;
 125
 126         m = *mp;
 127         ip = mtod(m, struct ip *);
 128
 129         /* Run through list of hooks for output packets. */
 130         odst.s_addr = ip->ip_dst.s_addr;
 131         switch (pfil_run_hooks(V_inet_pfil_head, mp, ifp, pflags, inp)) {
 132         case PFIL_DROPPED:
 133                 *error = EPERM;
 134                 /* FALLTHROUGH */
 135         case PFIL_CONSUMED:
 136                 return 1; /* Finished */
 137         case PFIL_PASS:
 138                 *error = 0;
 139         }
 140         m = *mp;
 141         ip = mtod(m, struct ip *);
 142
 143         /* See if destination IP address was changed by packet filter. */
 144         if (odst.s_addr != ip->ip_dst.s_addr) {
 145                 m->m_flags |= M_SKIP_FIREWALL;
 146                 /* If destination is now ourself drop to ip_input(). */
 147                 if (in_localip(ip->ip_dst)) {
 148                         m->m_flags |= M_FASTFWD_OURS;
 149                         if (m->m_pkthdr.rcvif == NULL)
 150                                 m->m_pkthdr.rcvif = V_loif;
 151                         if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
 152                                 m->m_pkthdr.csum_flags |=
 153                                         CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
 154                                 m->m_pkthdr.csum_data = 0xffff;
 155                         }
 156                         m->m_pkthdr.csum_flags |=
 157                                 CSUM_IP_CHECKED | CSUM_IP_VALID;
 158 #ifdef SCTP
 159                         if (m->m_pkthdr.csum_flags & CSUM_SCTP)
 160                                 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
 161 #endif
 162                         *error = netisr_queue(NETISR_IP, m);
 163                         return 1; /* Finished */
 164                 }
 165
 166                 bzero(dst, sizeof(*dst));
 167                 dst->sin_family = AF_INET;
 168                 dst->sin_len = sizeof(*dst);
 169                 dst->sin_addr = ip->ip_dst;
 170
 171                 return -1; /* Reloop */
 172         }
 173         /* See if fib was changed by packet filter. */
 174         if ((*fibnum) != M_GETFIB(m)) {
 175                 m->m_flags |= M_SKIP_FIREWALL;
 176                 *fibnum = M_GETFIB(m);
 177                 return -1; /* Reloop for FIB change */
 178         }
 179
 180         /* See if local, if yes, send it to netisr with IP_FASTFWD_OURS. */
 181         if (m->m_flags & M_FASTFWD_OURS) {
 182                 if (m->m_pkthdr.rcvif == NULL)
 183                         m->m_pkthdr.rcvif = V_loif;
 184                 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
 185                         m->m_pkthdr.csum_flags |=
 186                                 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
 187                         m->m_pkthdr.csum_data = 0xffff;
 188                 }
 189 #ifdef SCTP
 190                 if (m->m_pkthdr.csum_flags & CSUM_SCTP)
 191                         m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
 192 #endif
 193                 m->m_pkthdr.csum_flags |=
 194                         CSUM_IP_CHECKED | CSUM_IP_VALID;
 195
 196                 *error = netisr_queue(NETISR_IP, m);
 197                 return 1; /* Finished */
 198         }
 199         /* Or forward to some other address? */
 200         if ((m->m_flags & M_IP_NEXTHOP) &&
 201             ((fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL)) {
 202                 bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in));
 203                 m->m_flags |= M_SKIP_FIREWALL;
 204                 m->m_flags &= ~M_IP_NEXTHOP;
 205                 m_tag_delete(m, fwd_tag);
 206
 207                 return -1; /* Reloop for CHANGE of dst */
 208         }
 209
 210         return 0;
 211 }
 212
 213 static int
 214 ip_output_send(struct inpcb *inp, struct ifnet *ifp, struct mbuf *m,
 215     const struct sockaddr_in *gw, struct route *ro, bool stamp_tag)
 216 {
 217 #ifdef KERN_TLS
 218         struct ktls_session *tls = NULL;
 219 #endif
 220         struct m_snd_tag *mst;
 221         int error;
 222
 223         MPASS((m->m_pkthdr.csum_flags & CSUM_SND_TAG) == 0);
 224         mst = NULL;
 225
 226 #ifdef KERN_TLS
 227         /*
 228          * If this is an unencrypted TLS record, save a reference to
 229          * the record.  This local reference is used to call
 230          * ktls_output_eagain after the mbuf has been freed (thus
 231          * dropping the mbuf's reference) in if_output.
 232          */
 233         if (m->m_next != NULL && mbuf_has_tls_session(m->m_next)) {
 234                 tls = ktls_hold(m->m_next->m_ext.ext_pgs->tls);
 235                 mst = tls->snd_tag;
 236
 237                 /*
 238                  * If a TLS session doesn't have a valid tag, it must
 239                  * have had an earlier ifp mismatch, so drop this
 240                  * packet.
 241                  */
 242                 if (mst == NULL) {
 243                         error = EAGAIN;
 244                         goto done;
 245                 }
 246         }
 247 #endif
 248 #ifdef RATELIMIT
 249         if (inp != NULL && mst == NULL) {
 250                 if ((inp->inp_flags2 & INP_RATE_LIMIT_CHANGED) != 0 ||
 251                     (inp->inp_snd_tag != NULL &&
 252                     inp->inp_snd_tag->ifp != ifp))
 253                         in_pcboutput_txrtlmt(inp, ifp, m);
 254
 255                 if (inp->inp_snd_tag != NULL)
 256                         mst = inp->inp_snd_tag;
 257         }
 258 #endif
 259         if (stamp_tag && mst != NULL) {
 260                 KASSERT(m->m_pkthdr.rcvif == NULL,
 261                     ("trying to add a send tag to a forwarded packet"));
 262                 if (mst->ifp != ifp) {
 263                         error = EAGAIN;
 264                         goto done;
 265                 }
 266
 267                 /* stamp send tag on mbuf */
 268                 m->m_pkthdr.snd_tag = m_snd_tag_ref(mst);
 269                 m->m_pkthdr.csum_flags |= CSUM_SND_TAG;
 270         }
 271
 272         error = (*ifp->if_output)(ifp, m, (const struct sockaddr *)gw, ro);
 273
 274 done:
 275         /* Check for route change invalidating send tags. */
 276 #ifdef KERN_TLS
 277         if (tls != NULL) {
 278                 if (error == EAGAIN)
 279                         error = ktls_output_eagain(inp, tls);
 280                 ktls_free(tls);
 281         }
 282 #endif
 283 #ifdef RATELIMIT
 284         if (error == EAGAIN)
 285                 in_pcboutput_eagain(inp);
 286 #endif
 287         return (error);
 288 }
 289
 290 /*
 291  * IP output.  The packet in mbuf chain m contains a skeletal IP
 292  * header (with len, off, ttl, proto, tos, src, dst).
 293  * The mbuf chain containing the packet will be freed.
 294  * The mbuf opt, if present, will not be freed.
 295  * If route ro is present and has ro_rt initialized, route lookup would be
 296  * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL,
 297  * then result of route lookup is stored in ro->ro_rt.
 298  *
 299  * In the IP forwarding case, the packet will arrive with options already
 300  * inserted, so must have a NULL opt pointer.
 301  */
 302 int
 303 ip_output(struct mbuf *m, struct mbuf *opt, struct route *ro, int flags,
 304     struct ip_moptions *imo, struct inpcb *inp)
 305 {
 306         struct rm_priotracker in_ifa_tracker;
 307         struct epoch_tracker et;
 308         struct ip *ip;
 309         struct ifnet *ifp = NULL;       /* keep compiler happy */
 310         struct mbuf *m0;
 311         int hlen = sizeof (struct ip);
 312         int mtu;
 313         int error = 0;
 314         struct sockaddr_in *dst, sin;
 315         const struct sockaddr_in *gw;
 316         struct in_ifaddr *ia;
 317         struct in_addr src;
 318         int isbroadcast;
 319         uint16_t ip_len, ip_off;
 320         uint32_t fibnum;
 321 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
 322         int no_route_but_check_spd = 0;
 323 #endif
 324
 325         M_ASSERTPKTHDR(m);
 326
 327         if (inp != NULL) {
 328                 INP_LOCK_ASSERT(inp);
 329                 M_SETFIB(m, inp->inp_inc.inc_fibnum);
 330                 if ((flags & IP_NODEFAULTFLOWID) == 0) {
 331                         m->m_pkthdr.flowid = inp->inp_flowid;
 332                         M_HASHTYPE_SET(m, inp->inp_flowtype);
 333                 }
 334 #ifdef NUMA
 335                 m->m_pkthdr.numa_domain = inp->inp_numa_domain;
 336 #endif
 337         }
 338
 339         if (opt) {
 340                 int len = 0;
 341                 m = ip_insertoptions(m, opt, &len);
 342                 if (len != 0)
 343                         hlen = len; /* ip->ip_hl is updated above */
 344         }
 345         ip = mtod(m, struct ip *);
 346         ip_len = ntohs(ip->ip_len);
 347         ip_off = ntohs(ip->ip_off);
 348
 349         if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) {
 350                 ip->ip_v = IPVERSION;
 351                 ip->ip_hl = hlen >> 2;
 352                 ip_fillid(ip);
 353         } else {
 354                 /* Header already set, fetch hlen from there */
 355                 hlen = ip->ip_hl << 2;
 356         }
 357         if ((flags & IP_FORWARDING) == 0)
 358                 IPSTAT_INC(ips_localout);
 359
 360         /*
 361          * dst/gw handling:
 362          *
 363          * gw is readonly but can point either to dst OR rt_gateway,
 364          * therefore we need restore gw if we're redoing lookup.
 365          */
 366         fibnum = (inp != NULL) ? inp->inp_inc.inc_fibnum : M_GETFIB(m);
 367         if (ro != NULL)
 368                 dst = (struct sockaddr_in *)&ro->ro_dst;
 369         else
 370                 dst = &sin;
 371         if (ro == NULL || ro->ro_rt == NULL) {
 372                 bzero(dst, sizeof(*dst));
 373                 dst->sin_family = AF_INET;
 374                 dst->sin_len = sizeof(*dst);
 375                 dst->sin_addr = ip->ip_dst;
 376         }
 377         gw = dst;
 378         NET_EPOCH_ENTER(et);
 379 again:
 380         /*
 381          * Validate route against routing table additions;
 382          * a better/more specific route might have been added.
 383          */
 384         if (inp != NULL && ro != NULL && ro->ro_rt != NULL)
 385                 RT_VALIDATE(ro, &inp->inp_rt_cookie, fibnum);
 386         /*
 387          * If there is a cached route,
 388          * check that it is to the same destination
 389          * and is still up.  If not, free it and try again.
 390          * The address family should also be checked in case of sharing the
 391          * cache with IPv6.
 392          * Also check whether routing cache needs invalidation.
 393          */
 394         if (ro != NULL && ro->ro_rt != NULL &&
 395             ((ro->ro_rt->rt_flags & RTF_UP) == 0 ||
 396             ro->ro_rt->rt_ifp == NULL || !RT_LINK_IS_UP(ro->ro_rt->rt_ifp) ||
 397             dst->sin_family != AF_INET ||
 398             dst->sin_addr.s_addr != ip->ip_dst.s_addr))
 399                 RO_INVALIDATE_CACHE(ro);
 400         ia = NULL;
 401         /*
 402          * If routing to interface only, short circuit routing lookup.
 403          * The use of an all-ones broadcast address implies this; an
 404          * interface is specified by the broadcast address of an interface,
 405          * or the destination address of a ptp interface.
 406          */
 407         if (flags & IP_SENDONES) {
 408                 if ((ia = ifatoia(ifa_ifwithbroadaddr(sintosa(dst),
 409                                                       M_GETFIB(m)))) == NULL &&
 410                     (ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst),
 411                                                     M_GETFIB(m)))) == NULL) {
 412                         IPSTAT_INC(ips_noroute);
 413                         error = ENETUNREACH;
 414                         goto bad;
 415                 }
 416                 ip->ip_dst.s_addr = INADDR_BROADCAST;
 417                 dst->sin_addr = ip->ip_dst;
 418                 ifp = ia->ia_ifp;
 419                 mtu = ifp->if_mtu;
 420                 ip->ip_ttl = 1;
 421                 isbroadcast = 1;
 422                 src = IA_SIN(ia)->sin_addr;
 423         } else if (flags & IP_ROUTETOIF) {
 424                 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst),
 425                                                     M_GETFIB(m)))) == NULL &&
 426                     (ia = ifatoia(ifa_ifwithnet(sintosa(dst), 0,
 427                                                 M_GETFIB(m)))) == NULL) {
 428                         IPSTAT_INC(ips_noroute);
 429                         error = ENETUNREACH;
 430                         goto bad;
 431                 }
 432                 ifp = ia->ia_ifp;
 433                 mtu = ifp->if_mtu;
 434                 ip->ip_ttl = 1;
 435                 isbroadcast = ifp->if_flags & IFF_BROADCAST ?
 436                     in_ifaddr_broadcast(dst->sin_addr, ia) : 0;
 437                 src = IA_SIN(ia)->sin_addr;
 438         } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
 439             imo != NULL && imo->imo_multicast_ifp != NULL) {
 440                 /*
 441                  * Bypass the normal routing lookup for multicast
 442                  * packets if the interface is specified.
 443                  */
 444                 ifp = imo->imo_multicast_ifp;
 445                 mtu = ifp->if_mtu;
 446                 IFP_TO_IA(ifp, ia, &in_ifa_tracker);
 447                 isbroadcast = 0;        /* fool gcc */
 448                 /* Interface may have no addresses. */
 449                 if (ia != NULL)
 450                         src = IA_SIN(ia)->sin_addr;
 451                 else
 452                         src.s_addr = INADDR_ANY;
 453         } else if (ro != NULL) {
 454                 if (ro->ro_rt == NULL) {
 455                         /*
 456                          * We want to do any cloning requested by the link
 457                          * layer, as this is probably required in all cases
 458                          * for correct operation (as it is for ARP).
 459                          */
 460 #ifdef RADIX_MPATH
 461                         rtalloc_mpath_fib(ro,
 462                             ntohl(ip->ip_src.s_addr ^ ip->ip_dst.s_addr),
 463                             fibnum);
 464 #else
 465                         in_rtalloc_ign(ro, 0, fibnum);
 466 #endif
 467                         if (ro->ro_rt == NULL ||
 468                             (ro->ro_rt->rt_flags & RTF_UP) == 0 ||
 469                             ro->ro_rt->rt_ifp == NULL ||
 470                             !RT_LINK_IS_UP(ro->ro_rt->rt_ifp)) {
 471 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
 472                                 /*
 473                                  * There is no route for this packet, but it is
 474                                  * possible that a matching SPD entry exists.
 475                                  */
 476                                 no_route_but_check_spd = 1;
 477                                 mtu = 0; /* Silence GCC warning. */
 478                                 goto sendit;
 479 #endif
 480                                 IPSTAT_INC(ips_noroute);
 481                                 error = EHOSTUNREACH;
 482                                 goto bad;
 483                         }
 484                 }
 485                 ia = ifatoia(ro->ro_rt->rt_ifa);
 486                 ifp = ro->ro_rt->rt_ifp;
 487                 counter_u64_add(ro->ro_rt->rt_pksent, 1);
 488                 rt_update_ro_flags(ro);
 489                 if (ro->ro_rt->rt_flags & RTF_GATEWAY)
 490                         gw = (struct sockaddr_in *)ro->ro_rt->rt_gateway;
 491                 if (ro->ro_rt->rt_flags & RTF_HOST)
 492                         isbroadcast = (ro->ro_rt->rt_flags & RTF_BROADCAST);
 493                 else if (ifp->if_flags & IFF_BROADCAST)
 494                         isbroadcast = in_ifaddr_broadcast(gw->sin_addr, ia);
 495                 else
 496                         isbroadcast = 0;
 497                 if (ro->ro_rt->rt_flags & RTF_HOST)
 498                         mtu = ro->ro_rt->rt_mtu;
 499                 else
 500                         mtu = ifp->if_mtu;
 501                 src = IA_SIN(ia)->sin_addr;
 502         } else {
 503                 struct nhop4_extended nh;
 504
 505                 bzero(&nh, sizeof(nh));
 506                 if (fib4_lookup_nh_ext(M_GETFIB(m), ip->ip_dst, 0, 0, &nh) !=
 507                     0) {
 508 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
 509                         /*
 510                          * There is no route for this packet, but it is
 511                          * possible that a matching SPD entry exists.
 512                          */
 513                         no_route_but_check_spd = 1;
 514                         mtu = 0; /* Silence GCC warning. */
 515                         goto sendit;
 516 #endif
 517                         IPSTAT_INC(ips_noroute);
 518                         error = EHOSTUNREACH;
 519                         goto bad;
 520                 }
 521                 ifp = nh.nh_ifp;
 522                 mtu = nh.nh_mtu;
 523                 /*
 524                  * We are rewriting here dst to be gw actually, contradicting
 525                  * comment at the beginning of the function. However, in this
 526                  * case we are always dealing with on stack dst.
 527                  * In case if pfil(9) sends us back to beginning of the
 528                  * function, the dst would be rewritten by ip_output_pfil().
 529                  */
 530                 MPASS(dst == &sin);
 531                 dst->sin_addr = nh.nh_addr;
 532                 ia = nh.nh_ia;
 533                 src = nh.nh_src;
 534                 isbroadcast = (((nh.nh_flags & (NHF_HOST | NHF_BROADCAST)) ==
 535                     (NHF_HOST | NHF_BROADCAST)) ||
 536                     ((ifp->if_flags & IFF_BROADCAST) &&
 537                     in_ifaddr_broadcast(dst->sin_addr, ia)));
 538         }
 539
 540         /* Catch a possible divide by zero later. */
 541         KASSERT(mtu > 0, ("%s: mtu %d <= 0, ro=%p (rt_flags=0x%08x) ifp=%p",
 542             __func__, mtu, ro,
 543             (ro != NULL && ro->ro_rt != NULL) ? ro->ro_rt->rt_flags : 0, ifp));
 544
 545         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
 546                 m->m_flags |= M_MCAST;
 547                 /*
 548                  * IP destination address is multicast.  Make sure "gw"
 549                  * still points to the address in "ro".  (It may have been
 550                  * changed to point to a gateway address, above.)
 551                  */
 552                 gw = dst;
 553                 /*
 554                  * See if the caller provided any multicast options
 555                  */
 556                 if (imo != NULL) {
 557                         ip->ip_ttl = imo->imo_multicast_ttl;
 558                         if (imo->imo_multicast_vif != -1)
 559                                 ip->ip_src.s_addr =
 560                                     ip_mcast_src ?
 561                                     ip_mcast_src(imo->imo_multicast_vif) :
 562                                     INADDR_ANY;
 563                 } else
 564                         ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL;
 565                 /*
 566                  * Confirm that the outgoing interface supports multicast.
 567                  */
 568                 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) {
 569                         if ((ifp->if_flags & IFF_MULTICAST) == 0) {
 570                                 IPSTAT_INC(ips_noroute);
 571                                 error = ENETUNREACH;
 572                                 goto bad;
 573                         }
 574                 }
 575                 /*
 576                  * If source address not specified yet, use address
 577                  * of outgoing interface.
 578                  */
 579                 if (ip->ip_src.s_addr == INADDR_ANY)
 580                         ip->ip_src = src;
 581
 582                 if ((imo == NULL && in_mcast_loop) ||
 583                     (imo && imo->imo_multicast_loop)) {
 584                         /*
 585                          * Loop back multicast datagram if not expressly
 586                          * forbidden to do so, even if we are not a member
 587                          * of the group; ip_input() will filter it later,
 588                          * thus deferring a hash lookup and mutex acquisition
 589                          * at the expense of a cheap copy using m_copym().
 590                          */
 591                         ip_mloopback(ifp, m, hlen);
 592                 } else {
 593                         /*
 594                          * If we are acting as a multicast router, perform
 595                          * multicast forwarding as if the packet had just
 596                          * arrived on the interface to which we are about
 597                          * to send.  The multicast forwarding function
 598                          * recursively calls this function, using the
 599                          * IP_FORWARDING flag to prevent infinite recursion.
 600                          *
 601                          * Multicasts that are looped back by ip_mloopback(),
 602                          * above, will be forwarded by the ip_input() routine,
 603                          * if necessary.
 604                          */
 605                         if (V_ip_mrouter && (flags & IP_FORWARDING) == 0) {
 606                                 /*
 607                                  * If rsvp daemon is not running, do not
 608                                  * set ip_moptions. This ensures that the packet
 609                                  * is multicast and not just sent down one link
 610                                  * as prescribed by rsvpd.
 611                                  */
 612                                 if (!V_rsvp_on)
 613                                         imo = NULL;
 614                                 if (ip_mforward &&
 615                                     ip_mforward(ip, ifp, m, imo) != 0) {
 616                                         m_freem(m);
 617                                         goto done;
 618                                 }
 619                         }
 620                 }
 621
 622                 /*
 623                  * Multicasts with a time-to-live of zero may be looped-
 624                  * back, above, but must not be transmitted on a network.
 625                  * Also, multicasts addressed to the loopback interface
 626                  * are not sent -- the above call to ip_mloopback() will
 627                  * loop back a copy. ip_input() will drop the copy if
 628                  * this host does not belong to the destination group on
 629                  * the loopback interface.
 630                  */
 631                 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) {
 632                         m_freem(m);
 633                         goto done;
 634                 }
 635
 636                 goto sendit;
 637         }
 638
 639         /*
 640          * If the source address is not specified yet, use the address
 641          * of the outoing interface.
 642          */
 643         if (ip->ip_src.s_addr == INADDR_ANY)
 644                 ip->ip_src = src;
 645
 646         /*
 647          * Look for broadcast address and
 648          * verify user is allowed to send
 649          * such a packet.
 650          */
 651         if (isbroadcast) {
 652                 if ((ifp->if_flags & IFF_BROADCAST) == 0) {
 653                         error = EADDRNOTAVAIL;
 654                         goto bad;
 655                 }
 656                 if ((flags & IP_ALLOWBROADCAST) == 0) {
 657                         error = EACCES;
 658                         goto bad;
 659                 }
 660                 /* don't allow broadcast messages to be fragmented */
 661                 if (ip_len > mtu) {
 662                         error = EMSGSIZE;
 663                         goto bad;
 664                 }
 665                 m->m_flags |= M_BCAST;
 666         } else {
 667                 m->m_flags &= ~M_BCAST;
 668         }
 669
 670 sendit:
 671 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
 672         if (IPSEC_ENABLED(ipv4)) {
 673                 if ((error = IPSEC_OUTPUT(ipv4, m, inp)) != 0) {
 674                         if (error == EINPROGRESS)
 675                                 error = 0;
 676                         goto done;
 677                 }
 678         }
 679         /*
 680          * Check if there was a route for this packet; return error if not.
 681          */
 682         if (no_route_but_check_spd) {
 683                 IPSTAT_INC(ips_noroute);
 684                 error = EHOSTUNREACH;
 685                 goto bad;
 686         }
 687         /* Update variables that are affected by ipsec4_output(). */
 688         ip = mtod(m, struct ip *);
 689         hlen = ip->ip_hl << 2;
 690 #endif /* IPSEC */
 691
 692         /* Jump over all PFIL processing if hooks are not active. */
 693         if (PFIL_HOOKED_OUT(V_inet_pfil_head)) {
 694                 switch (ip_output_pfil(&m, ifp, flags, inp, dst, &fibnum,
 695                     &error)) {
 696                 case 1: /* Finished */
 697                         goto done;
 698
 699                 case 0: /* Continue normally */
 700                         ip = mtod(m, struct ip *);
 701                         break;
 702
 703                 case -1: /* Need to try again */
 704                         /* Reset everything for a new round */
 705                         if (ro != NULL) {
 706                                 RO_RTFREE(ro);
 707                                 ro->ro_prepend = NULL;
 708                         }
 709                         gw = dst;
 710                         ip = mtod(m, struct ip *);
 711                         goto again;
 712
 713                 }
 714         }
 715
 716         /* IN_LOOPBACK must not appear on the wire - RFC1122. */
 717         if (IN_LOOPBACK(ntohl(ip->ip_dst.s_addr)) ||
 718             IN_LOOPBACK(ntohl(ip->ip_src.s_addr))) {
 719                 if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
 720                         IPSTAT_INC(ips_badaddr);
 721                         error = EADDRNOTAVAIL;
 722                         goto bad;
 723                 }
 724         }
 725
 726         m->m_pkthdr.csum_flags |= CSUM_IP;
 727         if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA & ~ifp->if_hwassist) {
 728                 m = mb_unmapped_to_ext(m);
 729                 if (m == NULL) {
 730                         IPSTAT_INC(ips_odropped);
 731                         error = ENOBUFS;
 732                         goto bad;
 733                 }
 734                 in_delayed_cksum(m);
 735                 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
 736         } else if ((ifp->if_capenable & IFCAP_NOMAP) == 0) {
 737                 m = mb_unmapped_to_ext(m);
 738                 if (m == NULL) {
 739                         IPSTAT_INC(ips_odropped);
 740                         error = ENOBUFS;
 741                         goto bad;
 742                 }
 743         }
 744 #ifdef SCTP
 745         if (m->m_pkthdr.csum_flags & CSUM_SCTP & ~ifp->if_hwassist) {
 746                 m = mb_unmapped_to_ext(m);
 747                 if (m == NULL) {
 748                         IPSTAT_INC(ips_odropped);
 749                         error = ENOBUFS;
 750                         goto bad;
 751                 }
 752                 sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2));
 753                 m->m_pkthdr.csum_flags &= ~CSUM_SCTP;
 754         }
 755 #endif
 756
 757         /*
 758          * If small enough for interface, or the interface will take
 759          * care of the fragmentation for us, we can just send directly.
 760          */
 761         if (ip_len <= mtu ||
 762             (m->m_pkthdr.csum_flags & ifp->if_hwassist & CSUM_TSO) != 0) {
 763                 ip->ip_sum = 0;
 764                 if (m->m_pkthdr.csum_flags & CSUM_IP & ~ifp->if_hwassist) {
 765                         ip->ip_sum = in_cksum(m, hlen);
 766                         m->m_pkthdr.csum_flags &= ~CSUM_IP;
 767                 }
 768
 769                 /*
 770                  * Record statistics for this interface address.
 771                  * With CSUM_TSO the byte/packet count will be slightly
 772                  * incorrect because we count the IP+TCP headers only
 773                  * once instead of for every generated packet.
 774                  */
 775                 if (!(flags & IP_FORWARDING) && ia) {
 776                         if (m->m_pkthdr.csum_flags & CSUM_TSO)
 777                                 counter_u64_add(ia->ia_ifa.ifa_opackets,
 778                                     m->m_pkthdr.len / m->m_pkthdr.tso_segsz);
 779                         else
 780                                 counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
 781
 782                         counter_u64_add(ia->ia_ifa.ifa_obytes, m->m_pkthdr.len);
 783                 }
 784 #ifdef MBUF_STRESS_TEST
 785                 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size)
 786                         m = m_fragment(m, M_NOWAIT, mbuf_frag_size);
 787 #endif
 788                 /*
 789                  * Reset layer specific mbuf flags
 790                  * to avoid confusing lower layers.
 791                  */
 792                 m_clrprotoflags(m);
 793                 IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL);
 794                 error = ip_output_send(inp, ifp, m, gw, ro,
 795                     (flags & IP_NO_SND_TAG_RL) ? false : true);
 796                 goto done;
 797         }
 798
 799         /* Balk when DF bit is set or the interface didn't support TSO. */
 800         if ((ip_off & IP_DF) || (m->m_pkthdr.csum_flags & CSUM_TSO)) {
 801                 error = EMSGSIZE;
 802                 IPSTAT_INC(ips_cantfrag);
 803                 goto bad;
 804         }
 805
 806         /*
 807          * Too large for interface; fragment if possible. If successful,
 808          * on return, m will point to a list of packets to be sent.
 809          */
 810         error = ip_fragment(ip, &m, mtu, ifp->if_hwassist);
 811         if (error)
 812                 goto bad;
 813         for (; m; m = m0) {
 814                 m0 = m->m_nextpkt;
 815                 m->m_nextpkt = 0;
 816                 if (error == 0) {
 817                         /* Record statistics for this interface address. */
 818                         if (ia != NULL) {
 819                                 counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
 820                                 counter_u64_add(ia->ia_ifa.ifa_obytes,
 821                                     m->m_pkthdr.len);
 822                         }
 823                         /*
 824                          * Reset layer specific mbuf flags
 825                          * to avoid confusing upper layers.
 826                          */
 827                         m_clrprotoflags(m);
 828
 829                         IP_PROBE(send, NULL, NULL, mtod(m, struct ip *), ifp,
 830                             mtod(m, struct ip *), NULL);
 831                         error = ip_output_send(inp, ifp, m, gw, ro, true);
 832                 } else
 833                         m_freem(m);
 834         }
 835
 836         if (error == 0)
 837                 IPSTAT_INC(ips_fragmented);
 838
 839 done:
 840         NET_EPOCH_EXIT(et);
 841         return (error);
 842  bad:
 843         m_freem(m);
 844         goto done;
 845 }
 846
 847 /*
 848  * Create a chain of fragments which fit the given mtu. m_frag points to the
 849  * mbuf to be fragmented; on return it points to the chain with the fragments.
 850  * Return 0 if no error. If error, m_frag may contain a partially built
 851  * chain of fragments that should be freed by the caller.
 852  *
 853  * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist)
 854  */
 855 int
 856 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
 857     u_long if_hwassist_flags)
 858 {
 859         int error = 0;
 860         int hlen = ip->ip_hl << 2;
 861         int len = (mtu - hlen) & ~7;    /* size of payload in each fragment */
 862         int off;
 863         struct mbuf *m0 = *m_frag;      /* the original packet          */
 864         int firstlen;
 865         struct mbuf **mnext;
 866         int nfrags;
 867         uint16_t ip_len, ip_off;
 868
 869         ip_len = ntohs(ip->ip_len);
 870         ip_off = ntohs(ip->ip_off);
 871
 872         if (ip_off & IP_DF) {   /* Fragmentation not allowed */
 873                 IPSTAT_INC(ips_cantfrag);
 874                 return EMSGSIZE;
 875         }
 876
 877         /*
 878          * Must be able to put at least 8 bytes per fragment.
 879          */
 880         if (len < 8)
 881                 return EMSGSIZE;
 882
 883         /*
 884          * If the interface will not calculate checksums on
 885          * fragmented packets, then do it here.
 886          */
 887         if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
 888                 m0 = mb_unmapped_to_ext(m0);
 889                 if (m0 == NULL) {
 890                         error = ENOBUFS;
 891                         IPSTAT_INC(ips_odropped);
 892                         goto done;
 893                 }
 894                 in_delayed_cksum(m0);
 895                 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
 896         }
 897 #ifdef SCTP
 898         if (m0->m_pkthdr.csum_flags & CSUM_SCTP) {
 899                 m0 = mb_unmapped_to_ext(m0);
 900                 if (m0 == NULL) {
 901                         error = ENOBUFS;
 902                         IPSTAT_INC(ips_odropped);
 903                         goto done;
 904                 }
 905                 sctp_delayed_cksum(m0, hlen);
 906                 m0->m_pkthdr.csum_flags &= ~CSUM_SCTP;
 907         }
 908 #endif
 909         if (len > PAGE_SIZE) {
 910                 /*
 911                  * Fragment large datagrams such that each segment
 912                  * contains a multiple of PAGE_SIZE amount of data,
 913                  * plus headers. This enables a receiver to perform
 914                  * page-flipping zero-copy optimizations.
 915                  *
 916                  * XXX When does this help given that sender and receiver
 917                  * could have different page sizes, and also mtu could
 918                  * be less than the receiver's page size ?
 919                  */
 920                 int newlen;
 921
 922                 off = MIN(mtu, m0->m_pkthdr.len);
 923
 924                 /*
 925                  * firstlen (off - hlen) must be aligned on an
 926                  * 8-byte boundary
 927                  */
 928                 if (off < hlen)
 929                         goto smart_frag_failure;
 930                 off = ((off - hlen) & ~7) + hlen;
 931                 newlen = (~PAGE_MASK) & mtu;
 932                 if ((newlen + sizeof (struct ip)) > mtu) {
 933                         /* we failed, go back the default */
 934 smart_frag_failure:
 935                         newlen = len;
 936                         off = hlen + len;
 937                 }
 938                 len = newlen;
 939
 940         } else {
 941                 off = hlen + len;
 942         }
 943
 944         firstlen = off - hlen;
 945         mnext = &m0->m_nextpkt;         /* pointer to next packet */
 946
 947         /*
 948          * Loop through length of segment after first fragment,
 949          * make new header and copy data of each part and link onto chain.
 950          * Here, m0 is the original packet, m is the fragment being created.
 951          * The fragments are linked off the m_nextpkt of the original
 952          * packet, which after processing serves as the first fragment.
 953          */
 954         for (nfrags = 1; off < ip_len; off += len, nfrags++) {
 955                 struct ip *mhip;        /* ip header on the fragment */
 956                 struct mbuf *m;
 957                 int mhlen = sizeof (struct ip);
 958
 959                 m = m_gethdr(M_NOWAIT, MT_DATA);
 960                 if (m == NULL) {
 961                         error = ENOBUFS;
 962                         IPSTAT_INC(ips_odropped);
 963                         goto done;
 964                 }
 965                 /*
 966                  * Make sure the complete packet header gets copied
 967                  * from the originating mbuf to the newly created
 968                  * mbuf. This also ensures that existing firewall
 969                  * classification(s), VLAN tags and so on get copied
 970                  * to the resulting fragmented packet(s):
 971                  */
 972                 if (m_dup_pkthdr(m, m0, M_NOWAIT) == 0) {
 973                         m_free(m);
 974                         error = ENOBUFS;
 975                         IPSTAT_INC(ips_odropped);
 976                         goto done;
 977                 }
 978                 /*
 979                  * In the first mbuf, leave room for the link header, then
 980                  * copy the original IP header including options. The payload
 981                  * goes into an additional mbuf chain returned by m_copym().
 982                  */
 983                 m->m_data += max_linkhdr;
 984                 mhip = mtod(m, struct ip *);
 985                 *mhip = *ip;
 986                 if (hlen > sizeof (struct ip)) {
 987                         mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
 988                         mhip->ip_v = IPVERSION;
 989                         mhip->ip_hl = mhlen >> 2;
 990                 }
 991                 m->m_len = mhlen;
 992                 /* XXX do we need to add ip_off below ? */
 993                 mhip->ip_off = ((off - hlen) >> 3) + ip_off;
 994                 if (off + len >= ip_len)
 995                         len = ip_len - off;
 996                 else
 997                         mhip->ip_off |= IP_MF;
 998                 mhip->ip_len = htons((u_short)(len + mhlen));
 999                 m->m_next = m_copym(m0, off, len, M_NOWAIT);
1000                 if (m->m_next == NULL) {        /* copy failed */
1001                         m_free(m);
1002                         error = ENOBUFS;        /* ??? */
1003                         IPSTAT_INC(ips_odropped);
1004                         goto done;
1005                 }
1006                 m->m_pkthdr.len = mhlen + len;
1007 #ifdef MAC
1008                 mac_netinet_fragment(m0, m);
1009 #endif
1010                 mhip->ip_off = htons(mhip->ip_off);
1011                 mhip->ip_sum = 0;
1012                 if (m->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) {
1013                         mhip->ip_sum = in_cksum(m, mhlen);
1014                         m->m_pkthdr.csum_flags &= ~CSUM_IP;
1015                 }
1016                 *mnext = m;
1017                 mnext = &m->m_nextpkt;
1018         }
1019         IPSTAT_ADD(ips_ofragments, nfrags);
1020
1021         /*
1022          * Update first fragment by trimming what's been copied out
1023          * and updating header.
1024          */
1025         m_adj(m0, hlen + firstlen - ip_len);
1026         m0->m_pkthdr.len = hlen + firstlen;
1027         ip->ip_len = htons((u_short)m0->m_pkthdr.len);
1028         ip->ip_off = htons(ip_off | IP_MF);
1029         ip->ip_sum = 0;
1030         if (m0->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) {
1031                 ip->ip_sum = in_cksum(m0, hlen);
1032                 m0->m_pkthdr.csum_flags &= ~CSUM_IP;
1033         }
1034
1035 done:
1036         *m_frag = m0;
1037         return error;
1038 }
1039
1040 void
1041 in_delayed_cksum(struct mbuf *m)
1042 {
1043         struct ip *ip;
1044         struct udphdr *uh;
1045         uint16_t cklen, csum, offset;
1046
1047         ip = mtod(m, struct ip *);
1048         offset = ip->ip_hl << 2 ;
1049
1050         if (m->m_pkthdr.csum_flags & CSUM_UDP) {
1051                 /* if udp header is not in the first mbuf copy udplen */
1052                 if (offset + sizeof(struct udphdr) > m->m_len) {
1053                         m_copydata(m, offset + offsetof(struct udphdr,
1054                             uh_ulen), sizeof(cklen), (caddr_t)&cklen);
1055                         cklen = ntohs(cklen);
1056                 } else {
1057                         uh = (struct udphdr *)mtodo(m, offset);
1058                         cklen = ntohs(uh->uh_ulen);
1059                 }
1060                 csum = in_cksum_skip(m, cklen + offset, offset);
1061                 if (csum == 0)
1062                         csum = 0xffff;
1063         } else {
1064                 cklen = ntohs(ip->ip_len);
1065                 csum = in_cksum_skip(m, cklen, offset);
1066         }
1067         offset += m->m_pkthdr.csum_data;        /* checksum offset */
1068
1069         if (offset + sizeof(csum) > m->m_len)
1070                 m_copyback(m, offset, sizeof(csum), (caddr_t)&csum);
1071         else
1072                 *(u_short *)mtodo(m, offset) = csum;
1073 }
1074
1075 /*
1076  * IP socket option processing.
1077  */
1078 int
1079 ip_ctloutput(struct socket *so, struct sockopt *sopt)
1080 {
1081         struct inpcb *inp = sotoinpcb(so);
1082         int     error, optval;
1083 #ifdef  RSS
1084         uint32_t rss_bucket;
1085         int retval;
1086 #endif
1087
1088         error = optval = 0;
1089         if (sopt->sopt_level != IPPROTO_IP) {
1090                 error = EINVAL;
1091
1092                 if (sopt->sopt_level == SOL_SOCKET &&
1093                     sopt->sopt_dir == SOPT_SET) {
1094                         switch (sopt->sopt_name) {
1095                         case SO_REUSEADDR:
1096                                 INP_WLOCK(inp);
1097                                 if ((so->so_options & SO_REUSEADDR) != 0)
1098                                         inp->inp_flags2 |= INP_REUSEADDR;
1099                                 else
1100                                         inp->inp_flags2 &= ~INP_REUSEADDR;
1101                                 INP_WUNLOCK(inp);
1102                                 error = 0;
1103                                 break;
1104                         case SO_REUSEPORT:
1105                                 INP_WLOCK(inp);
1106                                 if ((so->so_options & SO_REUSEPORT) != 0)
1107                                         inp->inp_flags2 |= INP_REUSEPORT;
1108                                 else
1109                                         inp->inp_flags2 &= ~INP_REUSEPORT;
1110                                 INP_WUNLOCK(inp);
1111                                 error = 0;
1112                                 break;
1113                         case SO_REUSEPORT_LB:
1114                                 INP_WLOCK(inp);
1115                                 if ((so->so_options & SO_REUSEPORT_LB) != 0)
1116                                         inp->inp_flags2 |= INP_REUSEPORT_LB;
1117                                 else
1118                                         inp->inp_flags2 &= ~INP_REUSEPORT_LB;
1119                                 INP_WUNLOCK(inp);
1120                                 error = 0;
1121                                 break;
1122                         case SO_SETFIB:
1123                                 INP_WLOCK(inp);
1124                                 inp->inp_inc.inc_fibnum = so->so_fibnum;
1125                                 INP_WUNLOCK(inp);
1126                                 error = 0;
1127                                 break;
1128                         case SO_MAX_PACING_RATE:
1129 #ifdef RATELIMIT
1130                                 INP_WLOCK(inp);
1131                                 inp->inp_flags2 |= INP_RATE_LIMIT_CHANGED;
1132                                 INP_WUNLOCK(inp);
1133                                 error = 0;
1134 #else
1135                                 error = EOPNOTSUPP;
1136 #endif
1137                                 break;
1138                         default:
1139                                 break;
1140                         }
1141                 }
1142                 return (error);
1143         }
1144
1145         switch (sopt->sopt_dir) {
1146         case SOPT_SET:
1147                 switch (sopt->sopt_name) {
1148                 case IP_OPTIONS:
1149 #ifdef notyet
1150                 case IP_RETOPTS:
1151 #endif
1152                 {
1153                         struct mbuf *m;
1154                         if (sopt->sopt_valsize > MLEN) {
1155                                 error = EMSGSIZE;
1156                                 break;
1157                         }
1158                         m = m_get(sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA);
1159                         if (m == NULL) {
1160                                 error = ENOBUFS;
1161                                 break;
1162                         }
1163                         m->m_len = sopt->sopt_valsize;
1164                         error = sooptcopyin(sopt, mtod(m, char *), m->m_len,
1165                                             m->m_len);
1166                         if (error) {
1167                                 m_free(m);
1168                                 break;
1169                         }
1170                         INP_WLOCK(inp);
1171                         error = ip_pcbopts(inp, sopt->sopt_name, m);
1172                         INP_WUNLOCK(inp);
1173                         return (error);
1174                 }
1175
1176                 case IP_BINDANY:
1177                         if (sopt->sopt_td != NULL) {
1178                                 error = priv_check(sopt->sopt_td,
1179                                     PRIV_NETINET_BINDANY);
1180                                 if (error)
1181                                         break;
1182                         }
1183                         /* FALLTHROUGH */
1184                 case IP_BINDMULTI:
1185 #ifdef  RSS
1186                 case IP_RSS_LISTEN_BUCKET:
1187 #endif
1188                 case IP_TOS:
1189                 case IP_TTL:
1190                 case IP_MINTTL:
1191                 case IP_RECVOPTS:
1192                 case IP_RECVRETOPTS:
1193                 case IP_ORIGDSTADDR:
1194                 case IP_RECVDSTADDR:
1195                 case IP_RECVTTL:
1196                 case IP_RECVIF:
1197                 case IP_ONESBCAST:
1198                 case IP_DONTFRAG:
1199                 case IP_RECVTOS:
1200                 case IP_RECVFLOWID:
1201 #ifdef  RSS
1202                 case IP_RECVRSSBUCKETID:
1203 #endif
1204                         error = sooptcopyin(sopt, &optval, sizeof optval,
1205                                             sizeof optval);
1206                         if (error)
1207                                 break;
1208
1209                         switch (sopt->sopt_name) {
1210                         case IP_TOS:
1211                                 inp->inp_ip_tos = optval;
1212                                 break;
1213
1214                         case IP_TTL:
1215                                 inp->inp_ip_ttl = optval;
1216                                 break;
1217
1218                         case IP_MINTTL:
1219                                 if (optval >= 0 && optval <= MAXTTL)
1220                                         inp->inp_ip_minttl = optval;
1221                                 else
1222                                         error = EINVAL;
1223                                 break;
1224
1225 #define OPTSET(bit) do {                                                \
1226         INP_WLOCK(inp);                                                 \
1227         if (optval)                                                     \
1228                 inp->inp_flags |= bit;                                  \
1229         else                                                            \
1230                 inp->inp_flags &= ~bit;                                 \
1231         INP_WUNLOCK(inp);                                               \
1232 } while (0)
1233
1234 #define OPTSET2(bit, val) do {                                          \
1235         INP_WLOCK(inp);                                                 \
1236         if (val)                                                        \
1237                 inp->inp_flags2 |= bit;                                 \
1238         else                                                            \
1239                 inp->inp_flags2 &= ~bit;                                \
1240         INP_WUNLOCK(inp);                                               \
1241 } while (0)
1242
1243                         case IP_RECVOPTS:
1244                                 OPTSET(INP_RECVOPTS);
1245                                 break;
1246
1247                         case IP_RECVRETOPTS:
1248                                 OPTSET(INP_RECVRETOPTS);
1249                                 break;
1250
1251                         case IP_RECVDSTADDR:
1252                                 OPTSET(INP_RECVDSTADDR);
1253                                 break;
1254
1255                         case IP_ORIGDSTADDR:
1256                                 OPTSET2(INP_ORIGDSTADDR, optval);
1257                                 break;
1258
1259                         case IP_RECVTTL:
1260                                 OPTSET(INP_RECVTTL);
1261                                 break;
1262
1263                         case IP_RECVIF:
1264                                 OPTSET(INP_RECVIF);
1265                                 break;
1266
1267                         case IP_ONESBCAST:
1268                                 OPTSET(INP_ONESBCAST);
1269                                 break;
1270                         case IP_DONTFRAG:
1271                                 OPTSET(INP_DONTFRAG);
1272                                 break;
1273                         case IP_BINDANY:
1274                                 OPTSET(INP_BINDANY);
1275                                 break;
1276                         case IP_RECVTOS:
1277                                 OPTSET(INP_RECVTOS);
1278                                 break;
1279                         case IP_BINDMULTI:
1280                                 OPTSET2(INP_BINDMULTI, optval);
1281                                 break;
1282                         case IP_RECVFLOWID:
1283                                 OPTSET2(INP_RECVFLOWID, optval);
1284                                 break;
1285 #ifdef  RSS
1286                         case IP_RSS_LISTEN_BUCKET:
1287                                 if ((optval >= 0) &&
1288                                     (optval < rss_getnumbuckets())) {
1289                                         inp->inp_rss_listen_bucket = optval;
1290                                         OPTSET2(INP_RSS_BUCKET_SET, 1);
1291                                 } else {
1292                                         error = EINVAL;
1293                                 }
1294                                 break;
1295                         case IP_RECVRSSBUCKETID:
1296                                 OPTSET2(INP_RECVRSSBUCKETID, optval);
1297                                 break;
1298 #endif
1299                         }
1300                         break;
1301 #undef OPTSET
1302 #undef OPTSET2
1303
1304                 /*
1305                  * Multicast socket options are processed by the in_mcast
1306                  * module.
1307                  */
1308                 case IP_MULTICAST_IF:
1309                 case IP_MULTICAST_VIF:
1310                 case IP_MULTICAST_TTL:
1311                 case IP_MULTICAST_LOOP:
1312                 case IP_ADD_MEMBERSHIP:
1313                 case IP_DROP_MEMBERSHIP:
1314                 case IP_ADD_SOURCE_MEMBERSHIP:
1315                 case IP_DROP_SOURCE_MEMBERSHIP:
1316                 case IP_BLOCK_SOURCE:
1317                 case IP_UNBLOCK_SOURCE:
1318                 case IP_MSFILTER:
1319                 case MCAST_JOIN_GROUP:
1320                 case MCAST_LEAVE_GROUP:
1321                 case MCAST_JOIN_SOURCE_GROUP:
1322                 case MCAST_LEAVE_SOURCE_GROUP:
1323                 case MCAST_BLOCK_SOURCE:
1324                 case MCAST_UNBLOCK_SOURCE:
1325                         error = inp_setmoptions(inp, sopt);
1326                         break;
1327
1328                 case IP_PORTRANGE:
1329                         error = sooptcopyin(sopt, &optval, sizeof optval,
1330                                             sizeof optval);
1331                         if (error)
1332                                 break;
1333
1334                         INP_WLOCK(inp);
1335                         switch (optval) {
1336                         case IP_PORTRANGE_DEFAULT:
1337                                 inp->inp_flags &= ~(INP_LOWPORT);
1338                                 inp->inp_flags &= ~(INP_HIGHPORT);
1339                                 break;
1340
1341                         case IP_PORTRANGE_HIGH:
1342                                 inp->inp_flags &= ~(INP_LOWPORT);
1343                                 inp->inp_flags |= INP_HIGHPORT;
1344                                 break;
1345
1346                         case IP_PORTRANGE_LOW:
1347                                 inp->inp_flags &= ~(INP_HIGHPORT);
1348                                 inp->inp_flags |= INP_LOWPORT;
1349                                 break;
1350
1351                         default:
1352                                 error = EINVAL;
1353                                 break;
1354                         }
1355                         INP_WUNLOCK(inp);
1356                         break;
1357
1358 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
1359                 case IP_IPSEC_POLICY:
1360                         if (IPSEC_ENABLED(ipv4)) {
1361                                 error = IPSEC_PCBCTL(ipv4, inp, sopt);
1362                                 break;
1363                         }
1364                         /* FALLTHROUGH */
1365 #endif /* IPSEC */
1366
1367                 default:
1368                         error = ENOPROTOOPT;
1369                         break;
1370                 }
1371                 break;
1372
1373         case SOPT_GET:
1374                 switch (sopt->sopt_name) {
1375                 case IP_OPTIONS:
1376                 case IP_RETOPTS:
1377                         INP_RLOCK(inp);
1378                         if (inp->inp_options) {
1379                                 struct mbuf *options;
1380
1381                                 options = m_copym(inp->inp_options, 0,
1382                                     M_COPYALL, M_NOWAIT);
1383                                 INP_RUNLOCK(inp);
1384                                 if (options != NULL) {
1385                                         error = sooptcopyout(sopt,
1386                                                              mtod(options, char *),
1387                                                              options->m_len);
1388                                         m_freem(options);
1389                                 } else
1390                                         error = ENOMEM;
1391                         } else {
1392                                 INP_RUNLOCK(inp);
1393                                 sopt->sopt_valsize = 0;
1394                         }
1395                         break;
1396
1397                 case IP_TOS:
1398                 case IP_TTL:
1399                 case IP_MINTTL:
1400                 case IP_RECVOPTS:
1401                 case IP_RECVRETOPTS:
1402                 case IP_ORIGDSTADDR:
1403                 case IP_RECVDSTADDR:
1404                 case IP_RECVTTL:
1405                 case IP_RECVIF:
1406                 case IP_PORTRANGE:
1407                 case IP_ONESBCAST:
1408                 case IP_DONTFRAG:
1409                 case IP_BINDANY:
1410                 case IP_RECVTOS:
1411                 case IP_BINDMULTI:
1412                 case IP_FLOWID:
1413                 case IP_FLOWTYPE:
1414                 case IP_RECVFLOWID:
1415 #ifdef  RSS
1416                 case IP_RSSBUCKETID:
1417                 case IP_RECVRSSBUCKETID:
1418 #endif
1419                         switch (sopt->sopt_name) {
1420
1421                         case IP_TOS:
1422                                 optval = inp->inp_ip_tos;
1423                                 break;
1424
1425                         case IP_TTL:
1426                                 optval = inp->inp_ip_ttl;
1427                                 break;
1428
1429                         case IP_MINTTL:
1430                                 optval = inp->inp_ip_minttl;
1431                                 break;
1432
1433 #define OPTBIT(bit)     (inp->inp_flags & bit ? 1 : 0)
1434 #define OPTBIT2(bit)    (inp->inp_flags2 & bit ? 1 : 0)
1435
1436                         case IP_RECVOPTS:
1437                                 optval = OPTBIT(INP_RECVOPTS);
1438                                 break;
1439
1440                         case IP_RECVRETOPTS:
1441                                 optval = OPTBIT(INP_RECVRETOPTS);
1442                                 break;
1443
1444                         case IP_RECVDSTADDR:
1445                                 optval = OPTBIT(INP_RECVDSTADDR);
1446                                 break;
1447
1448                         case IP_ORIGDSTADDR:
1449                                 optval = OPTBIT2(INP_ORIGDSTADDR);
1450                                 break;
1451
1452                         case IP_RECVTTL:
1453                                 optval = OPTBIT(INP_RECVTTL);
1454                                 break;
1455
1456                         case IP_RECVIF:
1457                                 optval = OPTBIT(INP_RECVIF);
1458                                 break;
1459
1460                         case IP_PORTRANGE:
1461                                 if (inp->inp_flags & INP_HIGHPORT)
1462                                         optval = IP_PORTRANGE_HIGH;
1463                                 else if (inp->inp_flags & INP_LOWPORT)
1464                                         optval = IP_PORTRANGE_LOW;
1465                                 else
1466                                         optval = 0;
1467                                 break;
1468
1469                         case IP_ONESBCAST:
1470                                 optval = OPTBIT(INP_ONESBCAST);
1471                                 break;
1472                         case IP_DONTFRAG:
1473                                 optval = OPTBIT(INP_DONTFRAG);
1474                                 break;
1475                         case IP_BINDANY:
1476                                 optval = OPTBIT(INP_BINDANY);
1477                                 break;
1478                         case IP_RECVTOS:
1479                                 optval = OPTBIT(INP_RECVTOS);
1480                                 break;
1481                         case IP_FLOWID:
1482                                 optval = inp->inp_flowid;
1483                                 break;
1484                         case IP_FLOWTYPE:
1485                                 optval = inp->inp_flowtype;
1486                                 break;
1487                         case IP_RECVFLOWID:
1488                                 optval = OPTBIT2(INP_RECVFLOWID);
1489                                 break;
1490 #ifdef  RSS
1491                         case IP_RSSBUCKETID:
1492                                 retval = rss_hash2bucket(inp->inp_flowid,
1493                                     inp->inp_flowtype,
1494                                     &rss_bucket);
1495                                 if (retval == 0)
1496                                         optval = rss_bucket;
1497                                 else
1498                                         error = EINVAL;
1499                                 break;
1500                         case IP_RECVRSSBUCKETID:
1501                                 optval = OPTBIT2(INP_RECVRSSBUCKETID);
1502                                 break;
1503 #endif
1504                         case IP_BINDMULTI:
1505                                 optval = OPTBIT2(INP_BINDMULTI);
1506                                 break;
1507                         }
1508                         error = sooptcopyout(sopt, &optval, sizeof optval);
1509                         break;
1510
1511                 /*
1512                  * Multicast socket options are processed by the in_mcast
1513                  * module.
1514                  */
1515                 case IP_MULTICAST_IF:
1516                 case IP_MULTICAST_VIF:
1517                 case IP_MULTICAST_TTL:
1518                 case IP_MULTICAST_LOOP:
1519                 case IP_MSFILTER:
1520                         error = inp_getmoptions(inp, sopt);
1521                         break;
1522
1523 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
1524                 case IP_IPSEC_POLICY:
1525                         if (IPSEC_ENABLED(ipv4)) {
1526                                 error = IPSEC_PCBCTL(ipv4, inp, sopt);
1527                                 break;
1528                         }
1529                         /* FALLTHROUGH */
1530 #endif /* IPSEC */
1531
1532                 default:
1533                         error = ENOPROTOOPT;
1534                         break;
1535                 }
1536                 break;
1537         }
1538         return (error);
1539 }
1540
1541 /*
1542  * Routine called from ip_output() to loop back a copy of an IP multicast
1543  * packet to the input queue of a specified interface.  Note that this
1544  * calls the output routine of the loopback "driver", but with an interface
1545  * pointer that might NOT be a loopback interface -- evil, but easier than
1546  * replicating that code here.
1547  */
1548 static void
1549 ip_mloopback(struct ifnet *ifp, const struct mbuf *m, int hlen)
1550 {
1551         struct ip *ip;
1552         struct mbuf *copym;
1553
1554         /*
1555          * Make a deep copy of the packet because we're going to
1556          * modify the pack in order to generate checksums.
1557          */
1558         copym = m_dup(m, M_NOWAIT);
1559         if (copym != NULL && (!M_WRITABLE(copym) || copym->m_len < hlen))
1560                 copym = m_pullup(copym, hlen);
1561         if (copym != NULL) {
1562                 /* If needed, compute the checksum and mark it as valid. */
1563                 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
1564                         in_delayed_cksum(copym);
1565                         copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
1566                         copym->m_pkthdr.csum_flags |=
1567                             CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1568                         copym->m_pkthdr.csum_data = 0xffff;
1569                 }
1570                 /*
1571                  * We don't bother to fragment if the IP length is greater
1572                  * than the interface's MTU.  Can this possibly matter?
1573                  */
1574                 ip = mtod(copym, struct ip *);
1575                 ip->ip_sum = 0;
1576                 ip->ip_sum = in_cksum(copym, hlen);
1577                 if_simloop(ifp, copym, AF_INET, 0);
1578         }
1579 }