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