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_ratelimit.h"
  42 #include "opt_route.h"
  43 #include "opt_rss.h"
  44 #include "opt_sctp.h"
  45
  46 #include <sys/param.h>
  47 #include <sys/systm.h>
  48 #include <sys/kernel.h>
  49 #include <sys/ktls.h>
  50 #include <sys/lock.h>
  51 #include <sys/malloc.h>
  52 #include <sys/mbuf.h>
  53 #include <sys/priv.h>
  54 #include <sys/proc.h>
  55 #include <sys/protosw.h>
  56 #include <sys/rmlock.h>
  57 #include <sys/sdt.h>
  58 #include <sys/socket.h>
  59 #include <sys/socketvar.h>
  60 #include <sys/sysctl.h>
  61 #include <sys/ucred.h>
  62
  63 #include <net/if.h>
  64 #include <net/if_var.h>
  65 #include <net/if_llatbl.h>
  66 #include <net/netisr.h>
  67 #include <net/pfil.h>
  68 #include <net/route.h>
  69 #include <net/route/nhop.h>
  70 #include <net/rss_config.h>
  71 #include <net/vnet.h>
  72
  73 #include <netinet/in.h>
  74 #include <netinet/in_fib.h>
  75 #include <netinet/in_kdtrace.h>
  76 #include <netinet/in_systm.h>
  77 #include <netinet/ip.h>
  78 #include <netinet/in_fib.h>
  79 #include <netinet/in_pcb.h>
  80 #include <netinet/in_rss.h>
  81 #include <netinet/in_var.h>
  82 #include <netinet/ip_var.h>
  83 #include <netinet/ip_options.h>
  84
  85 #include <netinet/udp.h>
  86 #include <netinet/udp_var.h>
  87
  88 #if defined(SCTP) || defined(SCTP_SUPPORT)
  89 #include <netinet/sctp.h>
  90 #include <netinet/sctp_crc32.h>
  91 #endif
  92
  93 #include <netipsec/ipsec_support.h>
  94
  95 #include <machine/in_cksum.h>
  96
  97 #include <security/mac/mac_framework.h>
  98
  99 #ifdef MBUF_STRESS_TEST
 100 static int mbuf_frag_size = 0;
 101 SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW,
 102         &mbuf_frag_size, 0, "Fragment outgoing mbufs to this size");
 103 #endif
 104
 105 static void     ip_mloopback(struct ifnet *, const struct mbuf *, int);
 106
 107 extern int in_mcast_loop;
 108 extern  struct protosw inetsw[];
 109
 110 static inline int
 111 ip_output_pfil(struct mbuf **mp, struct ifnet *ifp, int flags,
 112     struct inpcb *inp, struct sockaddr_in *dst, int *fibnum, int *error)
 113 {
 114         struct m_tag *fwd_tag = NULL;
 115         struct mbuf *m;
 116         struct in_addr odst;
 117         struct ip *ip;
 118         int pflags = PFIL_OUT;
 119
 120         if (flags & IP_FORWARDING)
 121                 pflags |= PFIL_FWD;
 122
 123         m = *mp;
 124         ip = mtod(m, struct ip *);
 125
 126         /* Run through list of hooks for output packets. */
 127         odst.s_addr = ip->ip_dst.s_addr;
 128         switch (pfil_run_hooks(V_inet_pfil_head, mp, ifp, pflags, inp)) {
 129         case PFIL_DROPPED:
 130                 *error = EACCES;
 131                 /* FALLTHROUGH */
 132         case PFIL_CONSUMED:
 133                 return 1; /* Finished */
 134         case PFIL_PASS:
 135                 *error = 0;
 136         }
 137         m = *mp;
 138         ip = mtod(m, struct ip *);
 139
 140         /* See if destination IP address was changed by packet filter. */
 141         if (odst.s_addr != ip->ip_dst.s_addr) {
 142                 m->m_flags |= M_SKIP_FIREWALL;
 143                 /* If destination is now ourself drop to ip_input(). */
 144                 if (in_localip(ip->ip_dst)) {
 145                         m->m_flags |= M_FASTFWD_OURS;
 146                         if (m->m_pkthdr.rcvif == NULL)
 147                                 m->m_pkthdr.rcvif = V_loif;
 148                         if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
 149                                 m->m_pkthdr.csum_flags |=
 150                                         CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
 151                                 m->m_pkthdr.csum_data = 0xffff;
 152                         }
 153                         m->m_pkthdr.csum_flags |=
 154                                 CSUM_IP_CHECKED | CSUM_IP_VALID;
 155 #if defined(SCTP) || defined(SCTP_SUPPORT)
 156                         if (m->m_pkthdr.csum_flags & CSUM_SCTP)
 157                                 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
 158 #endif
 159                         *error = netisr_queue(NETISR_IP, m);
 160                         return 1; /* Finished */
 161                 }
 162
 163                 bzero(dst, sizeof(*dst));
 164                 dst->sin_family = AF_INET;
 165                 dst->sin_len = sizeof(*dst);
 166                 dst->sin_addr = ip->ip_dst;
 167
 168                 return -1; /* Reloop */
 169         }
 170         /* See if fib was changed by packet filter. */
 171         if ((*fibnum) != M_GETFIB(m)) {
 172                 m->m_flags |= M_SKIP_FIREWALL;
 173                 *fibnum = M_GETFIB(m);
 174                 return -1; /* Reloop for FIB change */
 175         }
 176
 177         /* See if local, if yes, send it to netisr with IP_FASTFWD_OURS. */
 178         if (m->m_flags & M_FASTFWD_OURS) {
 179                 if (m->m_pkthdr.rcvif == NULL)
 180                         m->m_pkthdr.rcvif = V_loif;
 181                 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
 182                         m->m_pkthdr.csum_flags |=
 183                                 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
 184                         m->m_pkthdr.csum_data = 0xffff;
 185                 }
 186 #if defined(SCTP) || defined(SCTP_SUPPORT)
 187                 if (m->m_pkthdr.csum_flags & CSUM_SCTP)
 188                         m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
 189 #endif
 190                 m->m_pkthdr.csum_flags |=
 191                         CSUM_IP_CHECKED | CSUM_IP_VALID;
 192
 193                 *error = netisr_queue(NETISR_IP, m);
 194                 return 1; /* Finished */
 195         }
 196         /* Or forward to some other address? */
 197         if ((m->m_flags & M_IP_NEXTHOP) &&
 198             ((fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL)) {
 199                 bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in));
 200                 m->m_flags |= M_SKIP_FIREWALL;
 201                 m->m_flags &= ~M_IP_NEXTHOP;
 202                 m_tag_delete(m, fwd_tag);
 203
 204                 return -1; /* Reloop for CHANGE of dst */
 205         }
 206
 207         return 0;
 208 }
 209
 210 static int
 211 ip_output_send(struct inpcb *inp, struct ifnet *ifp, struct mbuf *m,
 212     const struct sockaddr_in *gw, struct route *ro, bool stamp_tag)
 213 {
 214 #ifdef KERN_TLS
 215         struct ktls_session *tls = NULL;
 216 #endif
 217         struct m_snd_tag *mst;
 218         int error;
 219
 220         MPASS((m->m_pkthdr.csum_flags & CSUM_SND_TAG) == 0);
 221         mst = NULL;
 222
 223 #ifdef KERN_TLS
 224         /*
 225          * If this is an unencrypted TLS record, save a reference to
 226          * the record.  This local reference is used to call
 227          * ktls_output_eagain after the mbuf has been freed (thus
 228          * dropping the mbuf's reference) in if_output.
 229          */
 230         if (m->m_next != NULL && mbuf_has_tls_session(m->m_next)) {
 231                 tls = ktls_hold(m->m_next->m_epg_tls);
 232                 mst = tls->snd_tag;
 233
 234                 /*
 235                  * If a TLS session doesn't have a valid tag, it must
 236                  * have had an earlier ifp mismatch, so drop this
 237                  * packet.
 238                  */
 239                 if (mst == NULL) {
 240                         error = EAGAIN;
 241                         goto done;
 242                 }
 243                 /*
 244                  * Always stamp tags that include NIC ktls.
 245                  */
 246                 stamp_tag = true;
 247         }
 248 #endif
 249 #ifdef RATELIMIT
 250         if (inp != NULL && mst == NULL) {
 251                 if ((inp->inp_flags2 & INP_RATE_LIMIT_CHANGED) != 0 ||
 252                     (inp->inp_snd_tag != NULL &&
 253                     inp->inp_snd_tag->ifp != ifp))
 254                         in_pcboutput_txrtlmt(inp, ifp, m);
 255
 256                 if (inp->inp_snd_tag != NULL)
 257                         mst = inp->inp_snd_tag;
 258         }
 259 #endif
 260         if (stamp_tag && mst != NULL) {
 261                 KASSERT(m->m_pkthdr.rcvif == NULL,
 262                     ("trying to add a send tag to a forwarded packet"));
 263                 if (mst->ifp != ifp) {
 264                         error = EAGAIN;
 265                         goto done;
 266                 }
 267
 268                 /* stamp send tag on mbuf */
 269                 m->m_pkthdr.snd_tag = m_snd_tag_ref(mst);
 270                 m->m_pkthdr.csum_flags |= CSUM_SND_TAG;
 271         }
 272
 273         error = (*ifp->if_output)(ifp, m, (const struct sockaddr *)gw, ro);
 274
 275 done:
 276         /* Check for route change invalidating send tags. */
 277 #ifdef KERN_TLS
 278         if (tls != NULL) {
 279                 if (error == EAGAIN)
 280                         error = ktls_output_eagain(inp, tls);
 281                 ktls_free(tls);
 282         }
 283 #endif
 284 #ifdef RATELIMIT
 285         if (error == EAGAIN)
 286                 in_pcboutput_eagain(inp);
 287 #endif
 288         return (error);
 289 }
 290
 291 /* rte<>ro_flags translation */
 292 static inline void
 293 rt_update_ro_flags(struct route *ro)
 294 {
 295         int nh_flags = ro->ro_nh->nh_flags;
 296
 297         ro->ro_flags &= ~ (RT_REJECT|RT_BLACKHOLE|RT_HAS_GW);
 298
 299         ro->ro_flags |= (nh_flags & NHF_REJECT) ? RT_REJECT : 0;
 300         ro->ro_flags |= (nh_flags & NHF_BLACKHOLE) ? RT_BLACKHOLE : 0;
 301         ro->ro_flags |= (nh_flags & NHF_GATEWAY) ? RT_HAS_GW : 0;
 302 }
 303
 304 /*
 305  * IP output.  The packet in mbuf chain m contains a skeletal IP
 306  * header (with len, off, ttl, proto, tos, src, dst).
 307  * The mbuf chain containing the packet will be freed.
 308  * The mbuf opt, if present, will not be freed.
 309  * If route ro is present and has ro_rt initialized, route lookup would be
 310  * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL,
 311  * then result of route lookup is stored in ro->ro_rt.
 312  *
 313  * In the IP forwarding case, the packet will arrive with options already
 314  * inserted, so must have a NULL opt pointer.
 315  */
 316 int
 317 ip_output(struct mbuf *m, struct mbuf *opt, struct route *ro, int flags,
 318     struct ip_moptions *imo, struct inpcb *inp)
 319 {
 320         struct rm_priotracker in_ifa_tracker;
 321         struct ip *ip;
 322         struct ifnet *ifp = NULL;       /* keep compiler happy */
 323         struct mbuf *m0;
 324         int hlen = sizeof (struct ip);
 325         int mtu = 0;
 326         int error = 0;
 327         struct sockaddr_in *dst, sin;
 328         const struct sockaddr_in *gw;
 329         struct in_ifaddr *ia = NULL;
 330         struct in_addr src;
 331         int isbroadcast;
 332         uint16_t ip_len, ip_off;
 333         uint32_t fibnum;
 334 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
 335         int no_route_but_check_spd = 0;
 336 #endif
 337
 338         M_ASSERTPKTHDR(m);
 339         NET_EPOCH_ASSERT();
 340
 341         if (inp != NULL) {
 342                 INP_LOCK_ASSERT(inp);
 343                 M_SETFIB(m, inp->inp_inc.inc_fibnum);
 344                 if ((flags & IP_NODEFAULTFLOWID) == 0) {
 345                         m->m_pkthdr.flowid = inp->inp_flowid;
 346                         M_HASHTYPE_SET(m, inp->inp_flowtype);
 347                 }
 348 #ifdef NUMA
 349                 m->m_pkthdr.numa_domain = inp->inp_numa_domain;
 350 #endif
 351         }
 352
 353         if (opt) {
 354                 int len = 0;
 355                 m = ip_insertoptions(m, opt, &len);
 356                 if (len != 0)
 357                         hlen = len; /* ip->ip_hl is updated above */
 358         }
 359         ip = mtod(m, struct ip *);
 360         ip_len = ntohs(ip->ip_len);
 361         ip_off = ntohs(ip->ip_off);
 362
 363         if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) {
 364                 ip->ip_v = IPVERSION;
 365                 ip->ip_hl = hlen >> 2;
 366                 ip_fillid(ip);
 367         } else {
 368                 /* Header already set, fetch hlen from there */
 369                 hlen = ip->ip_hl << 2;
 370         }
 371         if ((flags & IP_FORWARDING) == 0)
 372                 IPSTAT_INC(ips_localout);
 373
 374         /*
 375          * dst/gw handling:
 376          *
 377          * gw is readonly but can point either to dst OR rt_gateway,
 378          * therefore we need restore gw if we're redoing lookup.
 379          */
 380         fibnum = (inp != NULL) ? inp->inp_inc.inc_fibnum : M_GETFIB(m);
 381         if (ro != NULL)
 382                 dst = (struct sockaddr_in *)&ro->ro_dst;
 383         else
 384                 dst = &sin;
 385         if (ro == NULL || ro->ro_nh == NULL) {
 386                 bzero(dst, sizeof(*dst));
 387                 dst->sin_family = AF_INET;
 388                 dst->sin_len = sizeof(*dst);
 389                 dst->sin_addr = ip->ip_dst;
 390         }
 391         gw = dst;
 392 again:
 393         /*
 394          * Validate route against routing table additions;
 395          * a better/more specific route might have been added.
 396          */
 397         if (inp != NULL && ro != NULL && ro->ro_nh != NULL)
 398                 NH_VALIDATE(ro, &inp->inp_rt_cookie, fibnum);
 399         /*
 400          * If there is a cached route,
 401          * check that it is to the same destination
 402          * and is still up.  If not, free it and try again.
 403          * The address family should also be checked in case of sharing the
 404          * cache with IPv6.
 405          * Also check whether routing cache needs invalidation.
 406          */
 407         if (ro != NULL && ro->ro_nh != NULL &&
 408             ((!NH_IS_VALID(ro->ro_nh)) || dst->sin_family != AF_INET ||
 409             dst->sin_addr.s_addr != ip->ip_dst.s_addr))
 410                 RO_INVALIDATE_CACHE(ro);
 411         ia = NULL;
 412         /*
 413          * If routing to interface only, short circuit routing lookup.
 414          * The use of an all-ones broadcast address implies this; an
 415          * interface is specified by the broadcast address of an interface,
 416          * or the destination address of a ptp interface.
 417          */
 418         if (flags & IP_SENDONES) {
 419                 if ((ia = ifatoia(ifa_ifwithbroadaddr(sintosa(dst),
 420                                                       M_GETFIB(m)))) == NULL &&
 421                     (ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst),
 422                                                     M_GETFIB(m)))) == NULL) {
 423                         IPSTAT_INC(ips_noroute);
 424                         error = ENETUNREACH;
 425                         goto bad;
 426                 }
 427                 ip->ip_dst.s_addr = INADDR_BROADCAST;
 428                 dst->sin_addr = ip->ip_dst;
 429                 ifp = ia->ia_ifp;
 430                 mtu = ifp->if_mtu;
 431                 ip->ip_ttl = 1;
 432                 isbroadcast = 1;
 433                 src = IA_SIN(ia)->sin_addr;
 434         } else if (flags & IP_ROUTETOIF) {
 435                 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst),
 436                                                     M_GETFIB(m)))) == NULL &&
 437                     (ia = ifatoia(ifa_ifwithnet(sintosa(dst), 0,
 438                                                 M_GETFIB(m)))) == NULL) {
 439                         IPSTAT_INC(ips_noroute);
 440                         error = ENETUNREACH;
 441                         goto bad;
 442                 }
 443                 ifp = ia->ia_ifp;
 444                 mtu = ifp->if_mtu;
 445                 ip->ip_ttl = 1;
 446                 isbroadcast = ifp->if_flags & IFF_BROADCAST ?
 447                     in_ifaddr_broadcast(dst->sin_addr, ia) : 0;
 448                 src = IA_SIN(ia)->sin_addr;
 449         } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
 450             imo != NULL && imo->imo_multicast_ifp != NULL) {
 451                 /*
 452                  * Bypass the normal routing lookup for multicast
 453                  * packets if the interface is specified.
 454                  */
 455                 ifp = imo->imo_multicast_ifp;
 456                 mtu = ifp->if_mtu;
 457                 IFP_TO_IA(ifp, ia, &in_ifa_tracker);
 458                 isbroadcast = 0;        /* fool gcc */
 459                 /* Interface may have no addresses. */
 460                 if (ia != NULL)
 461                         src = IA_SIN(ia)->sin_addr;
 462                 else
 463                         src.s_addr = INADDR_ANY;
 464         } else if (ro != NULL) {
 465                 if (ro->ro_nh == NULL) {
 466                         /*
 467                          * We want to do any cloning requested by the link
 468                          * layer, as this is probably required in all cases
 469                          * for correct operation (as it is for ARP).
 470                          */
 471                         uint32_t flowid;
 472                         flowid = m->m_pkthdr.flowid;
 473                         ro->ro_nh = fib4_lookup(fibnum, dst->sin_addr, 0,
 474                             NHR_REF, flowid);
 475
 476                         if (ro->ro_nh == NULL || (!NH_IS_VALID(ro->ro_nh))) {
 477 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
 478                                 /*
 479                                  * There is no route for this packet, but it is
 480                                  * possible that a matching SPD entry exists.
 481                                  */
 482                                 no_route_but_check_spd = 1;
 483                                 goto sendit;
 484 #endif
 485                                 IPSTAT_INC(ips_noroute);
 486                                 error = EHOSTUNREACH;
 487                                 goto bad;
 488                         }
 489                 }
 490                 ia = ifatoia(ro->ro_nh->nh_ifa);
 491                 ifp = ro->ro_nh->nh_ifp;
 492                 counter_u64_add(ro->ro_nh->nh_pksent, 1);
 493                 rt_update_ro_flags(ro);
 494                 if (ro->ro_nh->nh_flags & NHF_GATEWAY)
 495                         gw = &ro->ro_nh->gw4_sa;
 496                 if (ro->ro_nh->nh_flags & NHF_HOST)
 497                         isbroadcast = (ro->ro_nh->nh_flags & NHF_BROADCAST);
 498                 else if (ifp->if_flags & IFF_BROADCAST)
 499                         isbroadcast = in_ifaddr_broadcast(gw->sin_addr, ia);
 500                 else
 501                         isbroadcast = 0;
 502                 if (ro->ro_nh->nh_flags & NHF_HOST)
 503                         mtu = ro->ro_nh->nh_mtu;
 504                 else
 505                         mtu = ifp->if_mtu;
 506                 src = IA_SIN(ia)->sin_addr;
 507         } else {
 508                 struct nhop_object *nh;
 509
 510                 nh = fib4_lookup(M_GETFIB(m), ip->ip_dst, 0, NHR_NONE,
 511                     m->m_pkthdr.flowid);
 512                 if (nh == NULL) {
 513 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
 514                         /*
 515                          * There is no route for this packet, but it is
 516                          * possible that a matching SPD entry exists.
 517                          */
 518                         no_route_but_check_spd = 1;
 519                         goto sendit;
 520 #endif
 521                         IPSTAT_INC(ips_noroute);
 522                         error = EHOSTUNREACH;
 523                         goto bad;
 524                 }
 525                 ifp = nh->nh_ifp;
 526                 mtu = nh->nh_mtu;
 527                 /*
 528                  * We are rewriting here dst to be gw actually, contradicting
 529                  * comment at the beginning of the function. However, in this
 530                  * case we are always dealing with on stack dst.
 531                  * In case if pfil(9) sends us back to beginning of the
 532                  * function, the dst would be rewritten by ip_output_pfil().
 533                  */
 534                 MPASS(dst == &sin);
 535                 if (nh->nh_flags & NHF_GATEWAY)
 536                         dst->sin_addr = nh->gw4_sa.sin_addr;
 537                 ia = ifatoia(nh->nh_ifa);
 538                 src = IA_SIN(ia)->sin_addr;
 539                 isbroadcast = (((nh->nh_flags & (NHF_HOST | NHF_BROADCAST)) ==
 540                     (NHF_HOST | NHF_BROADCAST)) ||
 541                     ((ifp->if_flags & IFF_BROADCAST) &&
 542                     in_ifaddr_broadcast(dst->sin_addr, ia)));
 543         }
 544
 545         /* Catch a possible divide by zero later. */
 546         KASSERT(mtu > 0, ("%s: mtu %d <= 0, ro=%p (nh_flags=0x%08x) ifp=%p",
 547             __func__, mtu, ro,
 548             (ro != NULL && ro->ro_nh != NULL) ? ro->ro_nh->nh_flags : 0, ifp));
 549
 550         if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
 551                 m->m_flags |= M_MCAST;
 552                 /*
 553                  * IP destination address is multicast.  Make sure "gw"
 554                  * still points to the address in "ro".  (It may have been
 555                  * changed to point to a gateway address, above.)
 556                  */
 557                 gw = dst;
 558                 /*
 559                  * See if the caller provided any multicast options
 560                  */
 561                 if (imo != NULL) {
 562                         ip->ip_ttl = imo->imo_multicast_ttl;
 563                         if (imo->imo_multicast_vif != -1)
 564                                 ip->ip_src.s_addr =
 565                                     ip_mcast_src ?
 566                                     ip_mcast_src(imo->imo_multicast_vif) :
 567                                     INADDR_ANY;
 568                 } else
 569                         ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL;
 570                 /*
 571                  * Confirm that the outgoing interface supports multicast.
 572                  */
 573                 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) {
 574                         if ((ifp->if_flags & IFF_MULTICAST) == 0) {
 575                                 IPSTAT_INC(ips_noroute);
 576                                 error = ENETUNREACH;
 577                                 goto bad;
 578                         }
 579                 }
 580                 /*
 581                  * If source address not specified yet, use address
 582                  * of outgoing interface.
 583                  */
 584                 if (ip->ip_src.s_addr == INADDR_ANY)
 585                         ip->ip_src = src;
 586
 587                 if ((imo == NULL && in_mcast_loop) ||
 588                     (imo && imo->imo_multicast_loop)) {
 589                         /*
 590                          * Loop back multicast datagram if not expressly
 591                          * forbidden to do so, even if we are not a member
 592                          * of the group; ip_input() will filter it later,
 593                          * thus deferring a hash lookup and mutex acquisition
 594                          * at the expense of a cheap copy using m_copym().
 595                          */
 596                         ip_mloopback(ifp, m, hlen);
 597                 } else {
 598                         /*
 599                          * If we are acting as a multicast router, perform
 600                          * multicast forwarding as if the packet had just
 601                          * arrived on the interface to which we are about
 602                          * to send.  The multicast forwarding function
 603                          * recursively calls this function, using the
 604                          * IP_FORWARDING flag to prevent infinite recursion.
 605                          *
 606                          * Multicasts that are looped back by ip_mloopback(),
 607                          * above, will be forwarded by the ip_input() routine,
 608                          * if necessary.
 609                          */
 610                         if (V_ip_mrouter && (flags & IP_FORWARDING) == 0) {
 611                                 /*
 612                                  * If rsvp daemon is not running, do not
 613                                  * set ip_moptions. This ensures that the packet
 614                                  * is multicast and not just sent down one link
 615                                  * as prescribed by rsvpd.
 616                                  */
 617                                 if (!V_rsvp_on)
 618                                         imo = NULL;
 619                                 if (ip_mforward &&
 620                                     ip_mforward(ip, ifp, m, imo) != 0) {
 621                                         m_freem(m);
 622                                         goto done;
 623                                 }
 624                         }
 625                 }
 626
 627                 /*
 628                  * Multicasts with a time-to-live of zero may be looped-
 629                  * back, above, but must not be transmitted on a network.
 630                  * Also, multicasts addressed to the loopback interface
 631                  * are not sent -- the above call to ip_mloopback() will
 632                  * loop back a copy. ip_input() will drop the copy if
 633                  * this host does not belong to the destination group on
 634                  * the loopback interface.
 635                  */
 636                 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) {
 637                         m_freem(m);
 638                         goto done;
 639                 }
 640
 641                 goto sendit;
 642         }
 643
 644         /*
 645          * If the source address is not specified yet, use the address
 646          * of the outoing interface.
 647          */
 648         if (ip->ip_src.s_addr == INADDR_ANY)
 649                 ip->ip_src = src;
 650
 651         /*
 652          * Look for broadcast address and
 653          * verify user is allowed to send
 654          * such a packet.
 655          */
 656         if (isbroadcast) {
 657                 if ((ifp->if_flags & IFF_BROADCAST) == 0) {
 658                         error = EADDRNOTAVAIL;
 659                         goto bad;
 660                 }
 661                 if ((flags & IP_ALLOWBROADCAST) == 0) {
 662                         error = EACCES;
 663                         goto bad;
 664                 }
 665                 /* don't allow broadcast messages to be fragmented */
 666                 if (ip_len > mtu) {
 667                         error = EMSGSIZE;
 668                         goto bad;
 669                 }
 670                 m->m_flags |= M_BCAST;
 671         } else {
 672                 m->m_flags &= ~M_BCAST;
 673         }
 674
 675 sendit:
 676 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
 677         if (IPSEC_ENABLED(ipv4)) {
 678                 if ((error = IPSEC_OUTPUT(ipv4, m, inp)) != 0) {
 679                         if (error == EINPROGRESS)
 680                                 error = 0;
 681                         goto done;
 682                 }
 683         }
 684         /*
 685          * Check if there was a route for this packet; return error if not.
 686          */
 687         if (no_route_but_check_spd) {
 688                 IPSTAT_INC(ips_noroute);
 689                 error = EHOSTUNREACH;
 690                 goto bad;
 691         }
 692         /* Update variables that are affected by ipsec4_output(). */
 693         ip = mtod(m, struct ip *);
 694         hlen = ip->ip_hl << 2;
 695 #endif /* IPSEC */
 696
 697         /* Jump over all PFIL processing if hooks are not active. */
 698         if (PFIL_HOOKED_OUT(V_inet_pfil_head)) {
 699                 switch (ip_output_pfil(&m, ifp, flags, inp, dst, &fibnum,
 700                     &error)) {
 701                 case 1: /* Finished */
 702                         goto done;
 703
 704                 case 0: /* Continue normally */
 705                         ip = mtod(m, struct ip *);
 706                         break;
 707
 708                 case -1: /* Need to try again */
 709                         /* Reset everything for a new round */
 710                         if (ro != NULL) {
 711                                 RO_NHFREE(ro);
 712                                 ro->ro_prepend = NULL;
 713                         }
 714                         gw = dst;
 715                         ip = mtod(m, struct ip *);
 716                         goto again;
 717                 }
 718         }
 719
 720         /* IN_LOOPBACK must not appear on the wire - RFC1122. */
 721         if (IN_LOOPBACK(ntohl(ip->ip_dst.s_addr)) ||
 722             IN_LOOPBACK(ntohl(ip->ip_src.s_addr))) {
 723                 if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
 724                         IPSTAT_INC(ips_badaddr);
 725                         error = EADDRNOTAVAIL;
 726                         goto bad;
 727                 }
 728         }
 729
 730         m->m_pkthdr.csum_flags |= CSUM_IP;
 731         if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA & ~ifp->if_hwassist) {
 732                 m = mb_unmapped_to_ext(m);
 733                 if (m == NULL) {
 734                         IPSTAT_INC(ips_odropped);
 735                         error = ENOBUFS;
 736                         goto bad;
 737                 }
 738                 in_delayed_cksum(m);
 739                 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
 740         } else if ((ifp->if_capenable & IFCAP_NOMAP) == 0) {
 741                 m = mb_unmapped_to_ext(m);
 742                 if (m == NULL) {
 743                         IPSTAT_INC(ips_odropped);
 744                         error = ENOBUFS;
 745                         goto bad;
 746                 }
 747         }
 748 #if defined(SCTP) || defined(SCTP_SUPPORT)
 749         if (m->m_pkthdr.csum_flags & CSUM_SCTP & ~ifp->if_hwassist) {
 750                 m = mb_unmapped_to_ext(m);
 751                 if (m == NULL) {
 752                         IPSTAT_INC(ips_odropped);
 753                         error = ENOBUFS;
 754                         goto bad;
 755                 }
 756                 sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2));
 757                 m->m_pkthdr.csum_flags &= ~CSUM_SCTP;
 758         }
 759 #endif
 760
 761         /*
 762          * If small enough for interface, or the interface will take
 763          * care of the fragmentation for us, we can just send directly.
 764          * Note that if_vxlan could have requested TSO even though the outer
 765          * frame is UDP.  It is correct to not fragment such datagrams and
 766          * instead just pass them on to the driver.
 767          */
 768         if (ip_len <= mtu ||
 769             (m->m_pkthdr.csum_flags & ifp->if_hwassist &
 770             (CSUM_TSO | CSUM_INNER_TSO)) != 0) {
 771                 ip->ip_sum = 0;
 772                 if (m->m_pkthdr.csum_flags & CSUM_IP & ~ifp->if_hwassist) {
 773                         ip->ip_sum = in_cksum(m, hlen);
 774                         m->m_pkthdr.csum_flags &= ~CSUM_IP;
 775                 }
 776
 777                 /*
 778                  * Record statistics for this interface address.
 779                  * With CSUM_TSO the byte/packet count will be slightly
 780                  * incorrect because we count the IP+TCP headers only
 781                  * once instead of for every generated packet.
 782                  */
 783                 if (!(flags & IP_FORWARDING) && ia) {
 784                         if (m->m_pkthdr.csum_flags &
 785                             (CSUM_TSO | CSUM_INNER_TSO))
 786                                 counter_u64_add(ia->ia_ifa.ifa_opackets,
 787                                     m->m_pkthdr.len / m->m_pkthdr.tso_segsz);
 788                         else
 789                                 counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
 790
 791                         counter_u64_add(ia->ia_ifa.ifa_obytes, m->m_pkthdr.len);
 792                 }
 793 #ifdef MBUF_STRESS_TEST
 794                 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size)
 795                         m = m_fragment(m, M_NOWAIT, mbuf_frag_size);
 796 #endif
 797                 /*
 798                  * Reset layer specific mbuf flags
 799                  * to avoid confusing lower layers.
 800                  */
 801                 m_clrprotoflags(m);
 802                 IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL);
 803                 error = ip_output_send(inp, ifp, m, gw, ro,
 804                     (flags & IP_NO_SND_TAG_RL) ? false : true);
 805                 goto done;
 806         }
 807
 808         /* Balk when DF bit is set or the interface didn't support TSO. */
 809         if ((ip_off & IP_DF) ||
 810             (m->m_pkthdr.csum_flags & (CSUM_TSO | CSUM_INNER_TSO))) {
 811                 error = EMSGSIZE;
 812                 IPSTAT_INC(ips_cantfrag);
 813                 goto bad;
 814         }
 815
 816         /*
 817          * Too large for interface; fragment if possible. If successful,
 818          * on return, m will point to a list of packets to be sent.
 819          */
 820         error = ip_fragment(ip, &m, mtu, ifp->if_hwassist);
 821         if (error)
 822                 goto bad;
 823         for (; m; m = m0) {
 824                 m0 = m->m_nextpkt;
 825                 m->m_nextpkt = 0;
 826                 if (error == 0) {
 827                         /* Record statistics for this interface address. */
 828                         if (ia != NULL) {
 829                                 counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
 830                                 counter_u64_add(ia->ia_ifa.ifa_obytes,
 831                                     m->m_pkthdr.len);
 832                         }
 833                         /*
 834                          * Reset layer specific mbuf flags
 835                          * to avoid confusing upper layers.
 836                          */
 837                         m_clrprotoflags(m);
 838
 839                         IP_PROBE(send, NULL, NULL, mtod(m, struct ip *), ifp,
 840                             mtod(m, struct ip *), NULL);
 841                         error = ip_output_send(inp, ifp, m, gw, ro, true);
 842                 } else
 843                         m_freem(m);
 844         }
 845
 846         if (error == 0)
 847                 IPSTAT_INC(ips_fragmented);
 848
 849 done:
 850         return (error);
 851  bad:
 852         m_freem(m);
 853         goto done;
 854 }
 855
 856 /*
 857  * Create a chain of fragments which fit the given mtu. m_frag points to the
 858  * mbuf to be fragmented; on return it points to the chain with the fragments.
 859  * Return 0 if no error. If error, m_frag may contain a partially built
 860  * chain of fragments that should be freed by the caller.
 861  *
 862  * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist)
 863  */
 864 int
 865 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
 866     u_long if_hwassist_flags)
 867 {
 868         int error = 0;
 869         int hlen = ip->ip_hl << 2;
 870         int len = (mtu - hlen) & ~7;    /* size of payload in each fragment */
 871         int off;
 872         struct mbuf *m0 = *m_frag;      /* the original packet          */
 873         int firstlen;
 874         struct mbuf **mnext;
 875         int nfrags;
 876         uint16_t ip_len, ip_off;
 877
 878         ip_len = ntohs(ip->ip_len);
 879         ip_off = ntohs(ip->ip_off);
 880
 881         if (ip_off & IP_DF) {   /* Fragmentation not allowed */
 882                 IPSTAT_INC(ips_cantfrag);
 883                 return EMSGSIZE;
 884         }
 885
 886         /*
 887          * Must be able to put at least 8 bytes per fragment.
 888          */
 889         if (len < 8)
 890                 return EMSGSIZE;
 891
 892         /*
 893          * If the interface will not calculate checksums on
 894          * fragmented packets, then do it here.
 895          */
 896         if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
 897                 m0 = mb_unmapped_to_ext(m0);
 898                 if (m0 == NULL) {
 899                         error = ENOBUFS;
 900                         IPSTAT_INC(ips_odropped);
 901                         goto done;
 902                 }
 903                 in_delayed_cksum(m0);
 904                 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
 905         }
 906 #if defined(SCTP) || defined(SCTP_SUPPORT)
 907         if (m0->m_pkthdr.csum_flags & CSUM_SCTP) {
 908                 m0 = mb_unmapped_to_ext(m0);
 909                 if (m0 == NULL) {
 910                         error = ENOBUFS;
 911                         IPSTAT_INC(ips_odropped);
 912                         goto done;
 913                 }
 914                 sctp_delayed_cksum(m0, hlen);
 915                 m0->m_pkthdr.csum_flags &= ~CSUM_SCTP;
 916         }
 917 #endif
 918         if (len > PAGE_SIZE) {
 919                 /*
 920                  * Fragment large datagrams such that each segment
 921                  * contains a multiple of PAGE_SIZE amount of data,
 922                  * plus headers. This enables a receiver to perform
 923                  * page-flipping zero-copy optimizations.
 924                  *
 925                  * XXX When does this help given that sender and receiver
 926                  * could have different page sizes, and also mtu could
 927                  * be less than the receiver's page size ?
 928                  */
 929                 int newlen;
 930
 931                 off = MIN(mtu, m0->m_pkthdr.len);
 932
 933                 /*
 934                  * firstlen (off - hlen) must be aligned on an
 935                  * 8-byte boundary
 936                  */
 937                 if (off < hlen)
 938                         goto smart_frag_failure;
 939                 off = ((off - hlen) & ~7) + hlen;
 940                 newlen = (~PAGE_MASK) & mtu;
 941                 if ((newlen + sizeof (struct ip)) > mtu) {
 942                         /* we failed, go back the default */
 943 smart_frag_failure:
 944                         newlen = len;
 945                         off = hlen + len;
 946                 }
 947                 len = newlen;
 948
 949         } else {
 950                 off = hlen + len;
 951         }
 952
 953         firstlen = off - hlen;
 954         mnext = &m0->m_nextpkt;         /* pointer to next packet */
 955
 956         /*
 957          * Loop through length of segment after first fragment,
 958          * make new header and copy data of each part and link onto chain.
 959          * Here, m0 is the original packet, m is the fragment being created.
 960          * The fragments are linked off the m_nextpkt of the original
 961          * packet, which after processing serves as the first fragment.
 962          */
 963         for (nfrags = 1; off < ip_len; off += len, nfrags++) {
 964                 struct ip *mhip;        /* ip header on the fragment */
 965                 struct mbuf *m;
 966                 int mhlen = sizeof (struct ip);
 967
 968                 m = m_gethdr(M_NOWAIT, MT_DATA);
 969                 if (m == NULL) {
 970                         error = ENOBUFS;
 971                         IPSTAT_INC(ips_odropped);
 972                         goto done;
 973                 }
 974                 /*
 975                  * Make sure the complete packet header gets copied
 976                  * from the originating mbuf to the newly created
 977                  * mbuf. This also ensures that existing firewall
 978                  * classification(s), VLAN tags and so on get copied
 979                  * to the resulting fragmented packet(s):
 980                  */
 981                 if (m_dup_pkthdr(m, m0, M_NOWAIT) == 0) {
 982                         m_free(m);
 983                         error = ENOBUFS;
 984                         IPSTAT_INC(ips_odropped);
 985                         goto done;
 986                 }
 987                 /*
 988                  * In the first mbuf, leave room for the link header, then
 989                  * copy the original IP header including options. The payload
 990                  * goes into an additional mbuf chain returned by m_copym().
 991                  */
 992                 m->m_data += max_linkhdr;
 993                 mhip = mtod(m, struct ip *);
 994                 *mhip = *ip;
 995                 if (hlen > sizeof (struct ip)) {
 996                         mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
 997                         mhip->ip_v = IPVERSION;
 998                         mhip->ip_hl = mhlen >> 2;
 999                 }
1000                 m->m_len = mhlen;
1001                 /* XXX do we need to add ip_off below ? */
1002                 mhip->ip_off = ((off - hlen) >> 3) + ip_off;
1003                 if (off + len >= ip_len)
1004                         len = ip_len - off;
1005                 else
1006                         mhip->ip_off |= IP_MF;
1007                 mhip->ip_len = htons((u_short)(len + mhlen));
1008                 m->m_next = m_copym(m0, off, len, M_NOWAIT);
1009                 if (m->m_next == NULL) {        /* copy failed */
1010                         m_free(m);
1011                         error = ENOBUFS;        /* ??? */
1012                         IPSTAT_INC(ips_odropped);
1013                         goto done;
1014                 }
1015                 m->m_pkthdr.len = mhlen + len;
1016 #ifdef MAC
1017                 mac_netinet_fragment(m0, m);
1018 #endif
1019                 mhip->ip_off = htons(mhip->ip_off);
1020                 mhip->ip_sum = 0;
1021                 if (m->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) {
1022                         mhip->ip_sum = in_cksum(m, mhlen);
1023                         m->m_pkthdr.csum_flags &= ~CSUM_IP;
1024                 }
1025                 *mnext = m;
1026                 mnext = &m->m_nextpkt;
1027         }
1028         IPSTAT_ADD(ips_ofragments, nfrags);
1029
1030         /*
1031          * Update first fragment by trimming what's been copied out
1032          * and updating header.
1033          */
1034         m_adj(m0, hlen + firstlen - ip_len);
1035         m0->m_pkthdr.len = hlen + firstlen;
1036         ip->ip_len = htons((u_short)m0->m_pkthdr.len);
1037         ip->ip_off = htons(ip_off | IP_MF);
1038         ip->ip_sum = 0;
1039         if (m0->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) {
1040                 ip->ip_sum = in_cksum(m0, hlen);
1041                 m0->m_pkthdr.csum_flags &= ~CSUM_IP;
1042         }
1043
1044 done:
1045         *m_frag = m0;
1046         return error;
1047 }
1048
1049 void
1050 in_delayed_cksum(struct mbuf *m)
1051 {
1052         struct ip *ip;
1053         struct udphdr *uh;
1054         uint16_t cklen, csum, offset;
1055
1056         ip = mtod(m, struct ip *);
1057         offset = ip->ip_hl << 2 ;
1058
1059         if (m->m_pkthdr.csum_flags & CSUM_UDP) {
1060                 /* if udp header is not in the first mbuf copy udplen */
1061                 if (offset + sizeof(struct udphdr) > m->m_len) {
1062                         m_copydata(m, offset + offsetof(struct udphdr,
1063                             uh_ulen), sizeof(cklen), (caddr_t)&cklen);
1064                         cklen = ntohs(cklen);
1065                 } else {
1066                         uh = (struct udphdr *)mtodo(m, offset);
1067                         cklen = ntohs(uh->uh_ulen);
1068                 }
1069                 csum = in_cksum_skip(m, cklen + offset, offset);
1070                 if (csum == 0)
1071                         csum = 0xffff;
1072         } else {
1073                 cklen = ntohs(ip->ip_len);
1074                 csum = in_cksum_skip(m, cklen, offset);
1075         }
1076         offset += m->m_pkthdr.csum_data;        /* checksum offset */
1077
1078         if (offset + sizeof(csum) > m->m_len)
1079                 m_copyback(m, offset, sizeof(csum), (caddr_t)&csum);
1080         else
1081                 *(u_short *)mtodo(m, offset) = csum;
1082 }
1083
1084 /*
1085  * IP socket option processing.
1086  */
1087 int
1088 ip_ctloutput(struct socket *so, struct sockopt *sopt)
1089 {
1090         struct inpcb *inp = sotoinpcb(so);
1091         int     error, optval;
1092 #ifdef  RSS
1093         uint32_t rss_bucket;
1094         int retval;
1095 #endif
1096
1097         error = optval = 0;
1098         if (sopt->sopt_level != IPPROTO_IP) {
1099                 error = EINVAL;
1100
1101                 if (sopt->sopt_level == SOL_SOCKET &&
1102                     sopt->sopt_dir == SOPT_SET) {
1103                         switch (sopt->sopt_name) {
1104                         case SO_REUSEADDR:
1105                                 INP_WLOCK(inp);
1106                                 if ((so->so_options & SO_REUSEADDR) != 0)
1107                                         inp->inp_flags2 |= INP_REUSEADDR;
1108                                 else
1109                                         inp->inp_flags2 &= ~INP_REUSEADDR;
1110                                 INP_WUNLOCK(inp);
1111                                 error = 0;
1112                                 break;
1113                         case SO_REUSEPORT:
1114                                 INP_WLOCK(inp);
1115                                 if ((so->so_options & SO_REUSEPORT) != 0)
1116                                         inp->inp_flags2 |= INP_REUSEPORT;
1117                                 else
1118                                         inp->inp_flags2 &= ~INP_REUSEPORT;
1119                                 INP_WUNLOCK(inp);
1120                                 error = 0;
1121                                 break;
1122                         case SO_REUSEPORT_LB:
1123                                 INP_WLOCK(inp);
1124                                 if ((so->so_options & SO_REUSEPORT_LB) != 0)
1125                                         inp->inp_flags2 |= INP_REUSEPORT_LB;
1126                                 else
1127                                         inp->inp_flags2 &= ~INP_REUSEPORT_LB;
1128                                 INP_WUNLOCK(inp);
1129                                 error = 0;
1130                                 break;
1131                         case SO_SETFIB:
1132                                 INP_WLOCK(inp);
1133                                 inp->inp_inc.inc_fibnum = so->so_fibnum;
1134                                 INP_WUNLOCK(inp);
1135                                 error = 0;
1136                                 break;
1137                         case SO_MAX_PACING_RATE:
1138 #ifdef RATELIMIT
1139                                 INP_WLOCK(inp);
1140                                 inp->inp_flags2 |= INP_RATE_LIMIT_CHANGED;
1141                                 INP_WUNLOCK(inp);
1142                                 error = 0;
1143 #else
1144                                 error = EOPNOTSUPP;
1145 #endif
1146                                 break;
1147                         default:
1148                                 break;
1149                         }
1150                 }
1151                 return (error);
1152         }
1153
1154         switch (sopt->sopt_dir) {
1155         case SOPT_SET:
1156                 switch (sopt->sopt_name) {
1157                 case IP_OPTIONS:
1158 #ifdef notyet
1159                 case IP_RETOPTS:
1160 #endif
1161                 {
1162                         struct mbuf *m;
1163                         if (sopt->sopt_valsize > MLEN) {
1164                                 error = EMSGSIZE;
1165                                 break;
1166                         }
1167                         m = m_get(sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA);
1168                         if (m == NULL) {
1169                                 error = ENOBUFS;
1170                                 break;
1171                         }
1172                         m->m_len = sopt->sopt_valsize;
1173                         error = sooptcopyin(sopt, mtod(m, char *), m->m_len,
1174                                             m->m_len);
1175                         if (error) {
1176                                 m_free(m);
1177                                 break;
1178                         }
1179                         INP_WLOCK(inp);
1180                         error = ip_pcbopts(inp, sopt->sopt_name, m);
1181                         INP_WUNLOCK(inp);
1182                         return (error);
1183                 }
1184
1185                 case IP_BINDANY:
1186                         if (sopt->sopt_td != NULL) {
1187                                 error = priv_check(sopt->sopt_td,
1188                                     PRIV_NETINET_BINDANY);
1189                                 if (error)
1190                                         break;
1191                         }
1192                         /* FALLTHROUGH */
1193                 case IP_BINDMULTI:
1194 #ifdef  RSS
1195                 case IP_RSS_LISTEN_BUCKET:
1196 #endif
1197                 case IP_TOS:
1198                 case IP_TTL:
1199                 case IP_MINTTL:
1200                 case IP_RECVOPTS:
1201                 case IP_RECVRETOPTS:
1202                 case IP_ORIGDSTADDR:
1203                 case IP_RECVDSTADDR:
1204                 case IP_RECVTTL:
1205                 case IP_RECVIF:
1206                 case IP_ONESBCAST:
1207                 case IP_DONTFRAG:
1208                 case IP_RECVTOS:
1209                 case IP_RECVFLOWID:
1210 #ifdef  RSS
1211                 case IP_RECVRSSBUCKETID:
1212 #endif
1213                         error = sooptcopyin(sopt, &optval, sizeof optval,
1214                                             sizeof optval);
1215                         if (error)
1216                                 break;
1217
1218                         switch (sopt->sopt_name) {
1219                         case IP_TOS:
1220                                 inp->inp_ip_tos = optval;
1221                                 break;
1222
1223                         case IP_TTL:
1224                                 inp->inp_ip_ttl = optval;
1225                                 break;
1226
1227                         case IP_MINTTL:
1228                                 if (optval >= 0 && optval <= MAXTTL)
1229                                         inp->inp_ip_minttl = optval;
1230                                 else
1231                                         error = EINVAL;
1232                                 break;
1233
1234 #define OPTSET(bit) do {                                                \
1235         INP_WLOCK(inp);                                                 \
1236         if (optval)                                                     \
1237                 inp->inp_flags |= bit;                                  \
1238         else                                                            \
1239                 inp->inp_flags &= ~bit;                                 \
1240         INP_WUNLOCK(inp);                                               \
1241 } while (0)
1242
1243 #define OPTSET2(bit, val) do {                                          \
1244         INP_WLOCK(inp);                                                 \
1245         if (val)                                                        \
1246                 inp->inp_flags2 |= bit;                                 \
1247         else                                                            \
1248                 inp->inp_flags2 &= ~bit;                                \
1249         INP_WUNLOCK(inp);                                               \
1250 } while (0)
1251
1252                         case IP_RECVOPTS:
1253                                 OPTSET(INP_RECVOPTS);
1254                                 break;
1255
1256                         case IP_RECVRETOPTS:
1257                                 OPTSET(INP_RECVRETOPTS);
1258                                 break;
1259
1260                         case IP_RECVDSTADDR:
1261                                 OPTSET(INP_RECVDSTADDR);
1262                                 break;
1263
1264                         case IP_ORIGDSTADDR:
1265                                 OPTSET2(INP_ORIGDSTADDR, optval);
1266                                 break;
1267
1268                         case IP_RECVTTL:
1269                                 OPTSET(INP_RECVTTL);
1270                                 break;
1271
1272                         case IP_RECVIF:
1273                                 OPTSET(INP_RECVIF);
1274                                 break;
1275
1276                         case IP_ONESBCAST:
1277                                 OPTSET(INP_ONESBCAST);
1278                                 break;
1279                         case IP_DONTFRAG:
1280                                 OPTSET(INP_DONTFRAG);
1281                                 break;
1282                         case IP_BINDANY:
1283                                 OPTSET(INP_BINDANY);
1284                                 break;
1285                         case IP_RECVTOS:
1286                                 OPTSET(INP_RECVTOS);
1287                                 break;
1288                         case IP_BINDMULTI:
1289                                 OPTSET2(INP_BINDMULTI, optval);
1290                                 break;
1291                         case IP_RECVFLOWID:
1292                                 OPTSET2(INP_RECVFLOWID, optval);
1293                                 break;
1294 #ifdef  RSS
1295                         case IP_RSS_LISTEN_BUCKET:
1296                                 if ((optval >= 0) &&
1297                                     (optval < rss_getnumbuckets())) {
1298                                         inp->inp_rss_listen_bucket = optval;
1299                                         OPTSET2(INP_RSS_BUCKET_SET, 1);
1300                                 } else {
1301                                         error = EINVAL;
1302                                 }
1303                                 break;
1304                         case IP_RECVRSSBUCKETID:
1305                                 OPTSET2(INP_RECVRSSBUCKETID, optval);
1306                                 break;
1307 #endif
1308                         }
1309                         break;
1310 #undef OPTSET
1311 #undef OPTSET2
1312
1313                 /*
1314                  * Multicast socket options are processed by the in_mcast
1315                  * module.
1316                  */
1317                 case IP_MULTICAST_IF:
1318                 case IP_MULTICAST_VIF:
1319                 case IP_MULTICAST_TTL:
1320                 case IP_MULTICAST_LOOP:
1321                 case IP_ADD_MEMBERSHIP:
1322                 case IP_DROP_MEMBERSHIP:
1323                 case IP_ADD_SOURCE_MEMBERSHIP:
1324                 case IP_DROP_SOURCE_MEMBERSHIP:
1325                 case IP_BLOCK_SOURCE:
1326                 case IP_UNBLOCK_SOURCE:
1327                 case IP_MSFILTER:
1328                 case MCAST_JOIN_GROUP:
1329                 case MCAST_LEAVE_GROUP:
1330                 case MCAST_JOIN_SOURCE_GROUP:
1331                 case MCAST_LEAVE_SOURCE_GROUP:
1332                 case MCAST_BLOCK_SOURCE:
1333                 case MCAST_UNBLOCK_SOURCE:
1334                         error = inp_setmoptions(inp, sopt);
1335                         break;
1336
1337                 case IP_PORTRANGE:
1338                         error = sooptcopyin(sopt, &optval, sizeof optval,
1339                                             sizeof optval);
1340                         if (error)
1341                                 break;
1342
1343                         INP_WLOCK(inp);
1344                         switch (optval) {
1345                         case IP_PORTRANGE_DEFAULT:
1346                                 inp->inp_flags &= ~(INP_LOWPORT);
1347                                 inp->inp_flags &= ~(INP_HIGHPORT);
1348                                 break;
1349
1350                         case IP_PORTRANGE_HIGH:
1351                                 inp->inp_flags &= ~(INP_LOWPORT);
1352                                 inp->inp_flags |= INP_HIGHPORT;
1353                                 break;
1354
1355                         case IP_PORTRANGE_LOW:
1356                                 inp->inp_flags &= ~(INP_HIGHPORT);
1357                                 inp->inp_flags |= INP_LOWPORT;
1358                                 break;
1359
1360                         default:
1361                                 error = EINVAL;
1362                                 break;
1363                         }
1364                         INP_WUNLOCK(inp);
1365                         break;
1366
1367 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
1368                 case IP_IPSEC_POLICY:
1369                         if (IPSEC_ENABLED(ipv4)) {
1370                                 error = IPSEC_PCBCTL(ipv4, inp, sopt);
1371                                 break;
1372                         }
1373                         /* FALLTHROUGH */
1374 #endif /* IPSEC */
1375
1376                 default:
1377                         error = ENOPROTOOPT;
1378                         break;
1379                 }
1380                 break;
1381
1382         case SOPT_GET:
1383                 switch (sopt->sopt_name) {
1384                 case IP_OPTIONS:
1385                 case IP_RETOPTS:
1386                         INP_RLOCK(inp);
1387                         if (inp->inp_options) {
1388                                 struct mbuf *options;
1389
1390                                 options = m_copym(inp->inp_options, 0,
1391                                     M_COPYALL, M_NOWAIT);
1392                                 INP_RUNLOCK(inp);
1393                                 if (options != NULL) {
1394                                         error = sooptcopyout(sopt,
1395                                                              mtod(options, char *),
1396                                                              options->m_len);
1397                                         m_freem(options);
1398                                 } else
1399                                         error = ENOMEM;
1400                         } else {
1401                                 INP_RUNLOCK(inp);
1402                                 sopt->sopt_valsize = 0;
1403                         }
1404                         break;
1405
1406                 case IP_TOS:
1407                 case IP_TTL:
1408                 case IP_MINTTL:
1409                 case IP_RECVOPTS:
1410                 case IP_RECVRETOPTS:
1411                 case IP_ORIGDSTADDR:
1412                 case IP_RECVDSTADDR:
1413                 case IP_RECVTTL:
1414                 case IP_RECVIF:
1415                 case IP_PORTRANGE:
1416                 case IP_ONESBCAST:
1417                 case IP_DONTFRAG:
1418                 case IP_BINDANY:
1419                 case IP_RECVTOS:
1420                 case IP_BINDMULTI:
1421                 case IP_FLOWID:
1422                 case IP_FLOWTYPE:
1423                 case IP_RECVFLOWID:
1424 #ifdef  RSS
1425                 case IP_RSSBUCKETID:
1426                 case IP_RECVRSSBUCKETID:
1427 #endif
1428                         switch (sopt->sopt_name) {
1429                         case IP_TOS:
1430                                 optval = inp->inp_ip_tos;
1431                                 break;
1432
1433                         case IP_TTL:
1434                                 optval = inp->inp_ip_ttl;
1435                                 break;
1436
1437                         case IP_MINTTL:
1438                                 optval = inp->inp_ip_minttl;
1439                                 break;
1440
1441 #define OPTBIT(bit)     (inp->inp_flags & bit ? 1 : 0)
1442 #define OPTBIT2(bit)    (inp->inp_flags2 & bit ? 1 : 0)
1443
1444                         case IP_RECVOPTS:
1445                                 optval = OPTBIT(INP_RECVOPTS);
1446                                 break;
1447
1448                         case IP_RECVRETOPTS:
1449                                 optval = OPTBIT(INP_RECVRETOPTS);
1450                                 break;
1451
1452                         case IP_RECVDSTADDR:
1453                                 optval = OPTBIT(INP_RECVDSTADDR);
1454                                 break;
1455
1456                         case IP_ORIGDSTADDR:
1457                                 optval = OPTBIT2(INP_ORIGDSTADDR);
1458                                 break;
1459
1460                         case IP_RECVTTL:
1461                                 optval = OPTBIT(INP_RECVTTL);
1462                                 break;
1463
1464                         case IP_RECVIF:
1465                                 optval = OPTBIT(INP_RECVIF);
1466                                 break;
1467
1468                         case IP_PORTRANGE:
1469                                 if (inp->inp_flags & INP_HIGHPORT)
1470                                         optval = IP_PORTRANGE_HIGH;
1471                                 else if (inp->inp_flags & INP_LOWPORT)
1472                                         optval = IP_PORTRANGE_LOW;
1473                                 else
1474                                         optval = 0;
1475                                 break;
1476
1477                         case IP_ONESBCAST:
1478                                 optval = OPTBIT(INP_ONESBCAST);
1479                                 break;
1480                         case IP_DONTFRAG:
1481                                 optval = OPTBIT(INP_DONTFRAG);
1482                                 break;
1483                         case IP_BINDANY:
1484                                 optval = OPTBIT(INP_BINDANY);
1485                                 break;
1486                         case IP_RECVTOS:
1487                                 optval = OPTBIT(INP_RECVTOS);
1488                                 break;
1489                         case IP_FLOWID:
1490                                 optval = inp->inp_flowid;
1491                                 break;
1492                         case IP_FLOWTYPE:
1493                                 optval = inp->inp_flowtype;
1494                                 break;
1495                         case IP_RECVFLOWID:
1496                                 optval = OPTBIT2(INP_RECVFLOWID);
1497                                 break;
1498 #ifdef  RSS
1499                         case IP_RSSBUCKETID:
1500                                 retval = rss_hash2bucket(inp->inp_flowid,
1501                                     inp->inp_flowtype,
1502                                     &rss_bucket);
1503                                 if (retval == 0)
1504                                         optval = rss_bucket;
1505                                 else
1506                                         error = EINVAL;
1507                                 break;
1508                         case IP_RECVRSSBUCKETID:
1509                                 optval = OPTBIT2(INP_RECVRSSBUCKETID);
1510                                 break;
1511 #endif
1512                         case IP_BINDMULTI:
1513                                 optval = OPTBIT2(INP_BINDMULTI);
1514                                 break;
1515                         }
1516                         error = sooptcopyout(sopt, &optval, sizeof optval);
1517                         break;
1518
1519                 /*
1520                  * Multicast socket options are processed by the in_mcast
1521                  * module.
1522                  */
1523                 case IP_MULTICAST_IF:
1524                 case IP_MULTICAST_VIF:
1525                 case IP_MULTICAST_TTL:
1526                 case IP_MULTICAST_LOOP:
1527                 case IP_MSFILTER:
1528                         error = inp_getmoptions(inp, sopt);
1529                         break;
1530
1531 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
1532                 case IP_IPSEC_POLICY:
1533                         if (IPSEC_ENABLED(ipv4)) {
1534                                 error = IPSEC_PCBCTL(ipv4, inp, sopt);
1535                                 break;
1536                         }
1537                         /* FALLTHROUGH */
1538 #endif /* IPSEC */
1539
1540                 default:
1541                         error = ENOPROTOOPT;
1542                         break;
1543                 }
1544                 break;
1545         }
1546         return (error);
1547 }
1548
1549 /*
1550  * Routine called from ip_output() to loop back a copy of an IP multicast
1551  * packet to the input queue of a specified interface.  Note that this
1552  * calls the output routine of the loopback "driver", but with an interface
1553  * pointer that might NOT be a loopback interface -- evil, but easier than
1554  * replicating that code here.
1555  */
1556 static void
1557 ip_mloopback(struct ifnet *ifp, const struct mbuf *m, int hlen)
1558 {
1559         struct ip *ip;
1560         struct mbuf *copym;
1561
1562         /*
1563          * Make a deep copy of the packet because we're going to
1564          * modify the pack in order to generate checksums.
1565          */
1566         copym = m_dup(m, M_NOWAIT);
1567         if (copym != NULL && (!M_WRITABLE(copym) || copym->m_len < hlen))
1568                 copym = m_pullup(copym, hlen);
1569         if (copym != NULL) {
1570                 /* If needed, compute the checksum and mark it as valid. */
1571                 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
1572                         in_delayed_cksum(copym);
1573                         copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
1574                         copym->m_pkthdr.csum_flags |=
1575                             CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1576                         copym->m_pkthdr.csum_data = 0xffff;
1577                 }
1578                 /*
1579                  * We don't bother to fragment if the IP length is greater
1580                  * than the interface's MTU.  Can this possibly matter?
1581                  */
1582                 ip = mtod(copym, struct ip *);
1583                 ip->ip_sum = 0;
1584                 ip->ip_sum = in_cksum(copym, hlen);
1585                 if_simloop(ifp, copym, AF_INET, 0);
1586         }
1587 }