bsd/netinet6/udp6_output.c

   1 /*
   2  * Copyright (c) 2000-2014 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29
  30 /*      $FreeBSD: src/sys/netinet6/udp6_output.c,v 1.1.2.3 2001/08/31 13:49:58 jlemon Exp $     */
  31 /*      $KAME: udp6_output.c,v 1.31 2001/05/21 16:39:15 jinmei Exp $    */
  32
  33 /*
  34  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
  35  * All rights reserved.
  36  *
  37  * Redistribution and use in source and binary forms, with or without
  38  * modification, are permitted provided that the following conditions
  39  * are met:
  40  * 1. Redistributions of source code must retain the above copyright
  41  *    notice, this list of conditions and the following disclaimer.
  42  * 2. Redistributions in binary form must reproduce the above copyright
  43  *    notice, this list of conditions and the following disclaimer in the
  44  *    documentation and/or other materials provided with the distribution.
  45  * 3. Neither the name of the project nor the names of its contributors
  46  *    may be used to endorse or promote products derived from this software
  47  *    without specific prior written permission.
  48  *
  49  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  59  * SUCH DAMAGE.
  60  */
  61
  62 /*
  63  * Copyright (c) 1982, 1986, 1989, 1993
  64  *      The Regents of the University of California.  All rights reserved.
  65  *
  66  * Redistribution and use in source and binary forms, with or without
  67  * modification, are permitted provided that the following conditions
  68  * are met:
  69  * 1. Redistributions of source code must retain the above copyright
  70  *    notice, this list of conditions and the following disclaimer.
  71  * 2. Redistributions in binary form must reproduce the above copyright
  72  *    notice, this list of conditions and the following disclaimer in the
  73  *    documentation and/or other materials provided with the distribution.
  74  * 3. All advertising materials mentioning features or use of this software
  75  *    must display the following acknowledgement:
  76  *      This product includes software developed by the University of
  77  *      California, Berkeley and its contributors.
  78  * 4. Neither the name of the University nor the names of its contributors
  79  *    may be used to endorse or promote products derived from this software
  80  *    without specific prior written permission.
  81  *
  82  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  83  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  84  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  85  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  86  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  87  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  88  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  89  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  90  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  91  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  92  * SUCH DAMAGE.
  93  *
  94  *      @(#)udp_var.h   8.1 (Berkeley) 6/10/93
  95  */
  96
  97 #include <sys/param.h>
  98 #include <sys/malloc.h>
  99 #include <sys/mbuf.h>
 100 #include <sys/protosw.h>
 101 #include <sys/socket.h>
 102 #include <sys/socketvar.h>
 103 #include <sys/sysctl.h>
 104 #include <sys/errno.h>
 105 #include <sys/stat.h>
 106 #include <sys/systm.h>
 107 #include <sys/proc.h>
 108 #include <sys/syslog.h>
 109
 110 #include <machine/endian.h>
 111
 112 #include <net/if.h>
 113 #include <net/route.h>
 114 #include <net/if_types.h>
 115 #include <net/ntstat.h>
 116
 117 #include <netinet/in.h>
 118 #include <netinet/in_var.h>
 119 #include <netinet/in_systm.h>
 120 #include <netinet/ip.h>
 121 #include <netinet/ip_var.h>
 122 #include <netinet/in_pcb.h>
 123 #include <netinet/udp.h>
 124 #include <netinet/udp_var.h>
 125 #include <netinet/ip6.h>
 126 #include <netinet6/ip6_var.h>
 127 #include <netinet6/in6_pcb.h>
 128 #include <netinet6/udp6_var.h>
 129 #include <netinet/icmp6.h>
 130 #include <netinet6/ip6protosw.h>
 131
 132 #if NECP
 133 #include <net/necp.h>
 134 #endif /* NECP */
 135
 136 #include <net/net_osdep.h>
 137
 138 /*
 139  * UDP protocol inplementation.
 140  * Per RFC 768, August, 1980.
 141  */
 142 extern int soreserveheadroom;
 143
 144 int
 145 udp6_output(struct in6pcb *in6p, struct mbuf *m, struct sockaddr *addr6,
 146     struct mbuf *control, struct proc *p)
 147 {
 148         u_int32_t ulen = m->m_pkthdr.len;
 149         u_int32_t plen = sizeof (struct udphdr) + ulen;
 150         struct ip6_hdr *ip6;
 151         struct udphdr *udp6;
 152         struct in6_addr *laddr, *faddr;
 153         u_short fport;
 154         int error = 0;
 155         struct ip6_pktopts opt, *optp = NULL;
 156         struct ip6_moptions *im6o;
 157         int af = AF_INET6, hlen = sizeof (struct ip6_hdr);
 158         int flags;
 159         struct sockaddr_in6 tmp;
 160         struct  in6_addr storage;
 161         mbuf_svc_class_t msc = MBUF_SC_UNSPEC;
 162         struct ip6_out_args ip6oa =
 163             { IFSCOPE_NONE, { 0 }, IP6OAF_SELECT_SRCIF, 0 };
 164         struct flowadv *adv = &ip6oa.ip6oa_flowadv;
 165         struct socket *so = in6p->in6p_socket;
 166         struct route_in6 ro;
 167         int flowadv = 0;
 168
 169         /* Enable flow advisory only when connected */
 170         flowadv = (so->so_state & SS_ISCONNECTED) ? 1 : 0;
 171
 172         if (flowadv && INP_WAIT_FOR_IF_FEEDBACK(in6p)) {
 173                 error = ENOBUFS;
 174                 goto release;
 175         }
 176
 177         if (in6p->inp_flags & INP_BOUND_IF) {
 178                 ip6oa.ip6oa_boundif = in6p->inp_boundifp->if_index;
 179                 ip6oa.ip6oa_flags |= IP6OAF_BOUND_IF;
 180         }
 181         if (INP_NO_CELLULAR(in6p))
 182                 ip6oa.ip6oa_flags |= IP6OAF_NO_CELLULAR;
 183         if (INP_NO_EXPENSIVE(in6p))
 184                 ip6oa.ip6oa_flags |= IP6OAF_NO_EXPENSIVE;
 185         if (INP_AWDL_UNRESTRICTED(in6p))
 186                 ip6oa.ip6oa_flags |= IP6OAF_AWDL_UNRESTRICTED;
 187
 188         if (control) {
 189                 msc = mbuf_service_class_from_control(control);
 190                 if ((error = ip6_setpktopts(control, &opt,
 191                     NULL, IPPROTO_UDP)) != 0)
 192                         goto release;
 193                 optp = &opt;
 194         } else
 195                 optp = in6p->in6p_outputopts;
 196
 197         if (addr6) {
 198                 /*
 199                  * IPv4 version of udp_output calls in_pcbconnect in this case,
 200                  * which has its costs.
 201                  *
 202                  * Since we saw no essential reason for calling in_pcbconnect,
 203                  * we get rid of such kind of logic, and call in6_selectsrc
 204                  * and in6_pcbsetport in order to fill in the local address
 205                  * and the local port.
 206                  */
 207                 struct sockaddr_in6 *sin6 =
 208                     (struct sockaddr_in6 *)(void *)addr6;
 209
 210                 if (sin6->sin6_port == 0) {
 211                         error = EADDRNOTAVAIL;
 212                         goto release;
 213                 }
 214
 215                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
 216                         /* how about ::ffff:0.0.0.0 case? */
 217                         error = EISCONN;
 218                         goto release;
 219                 }
 220
 221                 /* protect *sin6 from overwrites */
 222                 tmp = *sin6;
 223                 sin6 = &tmp;
 224
 225                 faddr = &sin6->sin6_addr;
 226                 fport = sin6->sin6_port; /* allow 0 port */
 227
 228                 if (IN6_IS_ADDR_V4MAPPED(faddr)) {
 229                         if ((in6p->in6p_flags & IN6P_IPV6_V6ONLY)) {
 230                                 /*
 231                                  * I believe we should explicitly discard the
 232                                  * packet when mapped addresses are disabled,
 233                                  * rather than send the packet as an IPv6 one.
 234                                  * If we chose the latter approach, the packet
 235                                  * might be sent out on the wire based on the
 236                                  * default route, the situation which we'd
 237                                  * probably want to avoid.
 238                                  * (20010421 jinmei@kame.net)
 239                                  */
 240                                 error = EINVAL;
 241                                 goto release;
 242                         } else {
 243                                 af = AF_INET;
 244                         }
 245                 }
 246
 247                 /* KAME hack: embed scopeid */
 248                 if (in6_embedscope(&sin6->sin6_addr, sin6, in6p, NULL,
 249                     optp) != 0) {
 250                         error = EINVAL;
 251                         goto release;
 252                 }
 253
 254                 if (!IN6_IS_ADDR_V4MAPPED(faddr)) {
 255                         laddr = in6_selectsrc(sin6, optp,
 256                             in6p, &in6p->in6p_route, NULL, &storage,
 257                             ip6oa.ip6oa_boundif, &error);
 258                 } else
 259                         laddr = &in6p->in6p_laddr;      /* XXX */
 260                 if (laddr == NULL) {
 261                         if (error == 0)
 262                                 error = EADDRNOTAVAIL;
 263                         goto release;
 264                 }
 265                 if (in6p->in6p_lport == 0 &&
 266                     (error = in6_pcbsetport(laddr, in6p, p, 0)) != 0)
 267                         goto release;
 268         } else {
 269                 if (IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
 270                         error = ENOTCONN;
 271                         goto release;
 272                 }
 273                 if (IN6_IS_ADDR_V4MAPPED(&in6p->in6p_faddr)) {
 274                         if ((in6p->in6p_flags & IN6P_IPV6_V6ONLY)) {
 275                                 /*
 276                                  * XXX: this case would happen when the
 277                                  * application sets the V6ONLY flag after
 278                                  * connecting the foreign address.
 279                                  * Such applications should be fixed,
 280                                  * so we bark here.
 281                                  */
 282                                 log(LOG_INFO, "udp6_output: IPV6_V6ONLY "
 283                                     "option was set for a connected socket\n");
 284                                 error = EINVAL;
 285                                 goto release;
 286                         } else
 287                                 af = AF_INET;
 288                 }
 289                 laddr = &in6p->in6p_laddr;
 290                 faddr = &in6p->in6p_faddr;
 291                 fport = in6p->in6p_fport;
 292         }
 293
 294         if (in6p->inp_flowhash == 0)
 295                 in6p->inp_flowhash = inp_calc_flowhash(in6p);
 296         /* update flowinfo - RFC 6437 */
 297         if (in6p->inp_flow == 0 && in6p->in6p_flags & IN6P_AUTOFLOWLABEL) {
 298                 in6p->inp_flow &= ~IPV6_FLOWLABEL_MASK;
 299                 in6p->inp_flow |=
 300                     (htonl(in6p->inp_flowhash) & IPV6_FLOWLABEL_MASK);
 301         }
 302
 303         if (af == AF_INET)
 304                 hlen = sizeof (struct ip);
 305
 306         /*
 307          * Calculate data length and get a mbuf
 308          * for UDP and IP6 headers.
 309          */
 310         M_PREPEND(m, hlen + sizeof (struct udphdr), M_DONTWAIT, 1);
 311         if (m == 0) {
 312                 error = ENOBUFS;
 313                 goto release;
 314         }
 315
 316         /*
 317          * Stuff checksum and output datagram.
 318          */
 319         udp6 = (struct udphdr *)(void *)(mtod(m, caddr_t) + hlen);
 320         udp6->uh_sport = in6p->in6p_lport; /* lport is always set in the PCB */
 321         udp6->uh_dport = fport;
 322         if (plen <= 0xffff)
 323                 udp6->uh_ulen = htons((u_short)plen);
 324         else
 325                 udp6->uh_ulen = 0;
 326         udp6->uh_sum = 0;
 327
 328         switch (af) {
 329         case AF_INET6:
 330                 ip6 = mtod(m, struct ip6_hdr *);
 331                 ip6->ip6_flow   = in6p->inp_flow & IPV6_FLOWINFO_MASK;
 332                 ip6->ip6_vfc    &= ~IPV6_VERSION_MASK;
 333                 ip6->ip6_vfc    |= IPV6_VERSION;
 334 #if 0           /* ip6_plen will be filled in ip6_output. */
 335                 ip6->ip6_plen   = htons((u_short)plen);
 336 #endif
 337                 ip6->ip6_nxt    = IPPROTO_UDP;
 338                 ip6->ip6_hlim   = in6_selecthlim(in6p, in6p->in6p_route.ro_rt ?
 339                     in6p->in6p_route.ro_rt->rt_ifp : NULL);
 340                 ip6->ip6_src    = *laddr;
 341                 ip6->ip6_dst    = *faddr;
 342
 343                 udp6->uh_sum = in6_pseudo(laddr, faddr,
 344                     htonl(plen + IPPROTO_UDP));
 345                 m->m_pkthdr.csum_flags = CSUM_UDPIPV6;
 346                 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
 347
 348                 if (!IN6_IS_ADDR_UNSPECIFIED(laddr))
 349                         ip6oa.ip6oa_flags |= IP6OAF_BOUND_SRCADDR;
 350
 351                 flags = IPV6_OUTARGS;
 352
 353                 udp6stat.udp6s_opackets++;
 354
 355 #if NECP
 356                 {
 357                         necp_kernel_policy_id policy_id;
 358                         u_int32_t route_rule_id;
 359                         if (!necp_socket_is_allowed_to_send_recv_v6(in6p, in6p->in6p_lport, fport, laddr, faddr, NULL, &policy_id, &route_rule_id)) {
 360                                 error = EHOSTUNREACH;
 361                                 goto release;
 362                         }
 363
 364                         necp_mark_packet_from_socket(m, in6p, policy_id, route_rule_id);
 365                 }
 366 #endif /* NECP */
 367
 368 #if IPSEC
 369                 if (in6p->in6p_sp != NULL && ipsec_setsocket(m, so) != 0) {
 370                         error = ENOBUFS;
 371                         goto release;
 372                 }
 373 #endif /*IPSEC*/
 374
 375                 /* In case of IPv4-mapped address used in previous send */
 376                 if (ROUTE_UNUSABLE(&in6p->in6p_route) ||
 377                     rt_key(in6p->in6p_route.ro_rt)->sa_family != AF_INET6)
 378                         ROUTE_RELEASE(&in6p->in6p_route);
 379
 380                 /* Copy the cached route and take an extra reference */
 381                 in6p_route_copyout(in6p, &ro);
 382
 383                 set_packet_service_class(m, so, msc, PKT_SCF_IPV6);
 384
 385                 m->m_pkthdr.pkt_flowsrc = FLOWSRC_INPCB;
 386                 m->m_pkthdr.pkt_flowid = in6p->inp_flowhash;
 387                 m->m_pkthdr.pkt_proto = IPPROTO_UDP;
 388                 m->m_pkthdr.pkt_flags |= (PKTF_FLOW_ID | PKTF_FLOW_LOCALSRC);
 389                 if (flowadv)
 390                         m->m_pkthdr.pkt_flags |= PKTF_FLOW_ADV;
 391
 392                 im6o = in6p->in6p_moptions;
 393                 if (im6o != NULL) {
 394                         IM6O_LOCK(im6o);
 395                         IM6O_ADDREF_LOCKED(im6o);
 396                         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
 397                             im6o->im6o_multicast_ifp != NULL) {
 398                                 in6p->in6p_last_outifp =
 399                                     im6o->im6o_multicast_ifp;
 400                         }
 401                         IM6O_UNLOCK(im6o);
 402                 }
 403
 404                 in6p->inp_sndinprog_cnt++;
 405
 406                 socket_unlock(so, 0);
 407                 error = ip6_output(m, optp, &ro, flags, im6o, NULL, &ip6oa);
 408                 m = NULL;
 409                 socket_lock(so, 0);
 410
 411                 if (im6o != NULL)
 412                         IM6O_REMREF(im6o);
 413
 414                 if (error == 0 && nstat_collect) {
 415                         boolean_t cell, wifi, wired;
 416
 417                         if (in6p->in6p_route.ro_rt != NULL) {
 418                                 cell = IFNET_IS_CELLULAR(in6p->in6p_route.
 419                                     ro_rt->rt_ifp);
 420                                 wifi = (!cell && IFNET_IS_WIFI(in6p->in6p_route.
 421                                     ro_rt->rt_ifp));
 422                                 wired = (!wifi && IFNET_IS_WIRED(in6p->in6p_route.
 423                                     ro_rt->rt_ifp));
 424                         } else {
 425                                 cell = wifi = wired = FALSE;
 426                         }
 427                         INP_ADD_STAT(in6p, cell, wifi, wired, txpackets, 1);
 428                         INP_ADD_STAT(in6p, cell, wifi, wired, txbytes, ulen);
 429                 }
 430
 431                 if (flowadv && (adv->code == FADV_FLOW_CONTROLLED ||
 432                     adv->code == FADV_SUSPENDED)) {
 433                         /*
 434                          * Return an error to indicate
 435                          * that the packet has been dropped.
 436                          */
 437                         error = ENOBUFS;
 438                         inp_set_fc_state(in6p, adv->code);
 439                 }
 440
 441                 VERIFY(in6p->inp_sndinprog_cnt > 0);
 442                 if ( --in6p->inp_sndinprog_cnt == 0)
 443                         in6p->inp_flags &= ~(INP_FC_FEEDBACK);
 444
 445                 if (ro.ro_rt != NULL) {
 446                         struct ifnet *outif = ro.ro_rt->rt_ifp;
 447
 448                         so->so_pktheadroom = P2ROUNDUP(
 449                             sizeof(struct udphdr) +
 450                             hlen +
 451                             ifnet_hdrlen(outif) +
 452                             ifnet_packetpreamblelen(outif),
 453                             sizeof(u_int32_t));
 454                 }
 455
 456                 /* Synchronize PCB cached route */
 457                 in6p_route_copyin(in6p, &ro);
 458
 459                 if (in6p->in6p_route.ro_rt != NULL) {
 460                         struct rtentry *rt = in6p->in6p_route.ro_rt;
 461                         struct ifnet *outif;
 462
 463                         if (rt->rt_flags & RTF_MULTICAST)
 464                                 rt = NULL;      /* unusable */
 465
 466                         /*
 467                          * Always discard the cached route for unconnected
 468                          * socket or if it is a multicast route.
 469                          */
 470                         if (rt == NULL)
 471                                 ROUTE_RELEASE(&in6p->in6p_route);
 472
 473                         /*
 474                          * If the destination route is unicast, update outif
 475                          * with that of the route interface used by IP.
 476                          */
 477                         if (rt != NULL &&
 478                             (outif = rt->rt_ifp) != in6p->in6p_last_outifp) {
 479                                 in6p->in6p_last_outifp = outif;
 480
 481                                 so->so_pktheadroom = P2ROUNDUP(
 482                                     sizeof(struct udphdr) +
 483                                     hlen +
 484                                     ifnet_hdrlen(outif) +
 485                                     ifnet_packetpreamblelen(outif),
 486                                     sizeof(u_int32_t));
 487                         }
 488                 } else {
 489                         ROUTE_RELEASE(&in6p->in6p_route);
 490                 }
 491
 492                 /*
 493                  * If output interface was cellular/expensive, and this
 494                  * socket is denied access to it, generate an event.
 495                  */
 496                 if (error != 0 && (ip6oa.ip6oa_retflags & IP6OARF_IFDENIED) &&
 497                     (INP_NO_CELLULAR(in6p) || INP_NO_EXPENSIVE(in6p)))
 498                         soevent(in6p->inp_socket, (SO_FILT_HINT_LOCKED|
 499                             SO_FILT_HINT_IFDENIED));
 500                 break;
 501         case AF_INET:
 502                 error = EAFNOSUPPORT;
 503                 goto release;
 504         }
 505         goto releaseopt;
 506
 507 release:
 508         if (m != NULL)
 509                 m_freem(m);
 510
 511 releaseopt:
 512         if (control != NULL) {
 513                 if (optp == &opt)
 514                         ip6_clearpktopts(optp, -1);
 515                 m_freem(control);
 516         }
 517         return (error);
 518 }