bsd/netinet6/udp6_output.c

   1 /*
   2  * Copyright (c) 2000-2013 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 IPSEC
 133 #include <netinet6/ipsec.h>
 134 #include <netinet6/ipsec6.h>
 135 extern int ipsec_bypass;
 136 #endif /* IPSEC */
 137
 138 #include <net/net_osdep.h>
 139
 140 /*
 141  * UDP protocol inplementation.
 142  * Per RFC 768, August, 1980.
 143  */
 144
 145 int
 146 udp6_output(struct in6pcb *in6p, struct mbuf *m, struct sockaddr *addr6,
 147     struct mbuf *control, struct proc *p)
 148 {
 149         u_int32_t ulen = m->m_pkthdr.len;
 150         u_int32_t plen = sizeof (struct udphdr) + ulen;
 151         struct ip6_hdr *ip6;
 152         struct udphdr *udp6;
 153         struct in6_addr *laddr, *faddr;
 154         u_short fport;
 155         int error = 0;
 156         struct ip6_pktopts opt, *optp = NULL;
 157         struct ip6_moptions *im6o;
 158         int af = AF_INET6, hlen = sizeof (struct ip6_hdr);
 159         int flags;
 160         struct sockaddr_in6 tmp;
 161         struct  in6_addr storage;
 162         mbuf_svc_class_t msc = MBUF_SC_UNSPEC;
 163         struct ip6_out_args ip6oa =
 164             { IFSCOPE_NONE, { 0 }, IP6OAF_SELECT_SRCIF, 0 };
 165         struct flowadv *adv = &ip6oa.ip6oa_flowadv;
 166         struct socket *so = in6p->in6p_socket;
 167         struct route_in6 ro;
 168         int flowadv = 0;
 169
 170         /* Enable flow advisory only when connected */
 171         flowadv = (so->so_state & SS_ISCONNECTED) ? 1 : 0;
 172
 173         if (flowadv && INP_WAIT_FOR_IF_FEEDBACK(in6p)) {
 174                 error = ENOBUFS;
 175                 goto release;
 176         }
 177
 178         if (in6p->inp_flags & INP_BOUND_IF) {
 179                 ip6oa.ip6oa_boundif = in6p->inp_boundifp->if_index;
 180                 ip6oa.ip6oa_flags |= IP6OAF_BOUND_IF;
 181         }
 182         if (in6p->inp_flags & INP_NO_IFT_CELLULAR)
 183                 ip6oa.ip6oa_flags |= IP6OAF_NO_CELLULAR;
 184
 185         if (control) {
 186                 msc = mbuf_service_class_from_control(control);
 187                 if ((error = ip6_setpktopts(control, &opt,
 188                     NULL, IPPROTO_UDP)) != 0)
 189                         goto release;
 190                 optp = &opt;
 191         } else
 192                 optp = in6p->in6p_outputopts;
 193
 194         if (addr6) {
 195                 /*
 196                  * IPv4 version of udp_output calls in_pcbconnect in this case,
 197                  * which has its costs.
 198                  *
 199                  * Since we saw no essential reason for calling in_pcbconnect,
 200                  * we get rid of such kind of logic, and call in6_selectsrc
 201                  * and in6_pcbsetport in order to fill in the local address
 202                  * and the local port.
 203                  */
 204                 struct sockaddr_in6 *sin6 =
 205                     (struct sockaddr_in6 *)(void *)addr6;
 206
 207                 if (sin6->sin6_port == 0) {
 208                         error = EADDRNOTAVAIL;
 209                         goto release;
 210                 }
 211
 212                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
 213                         /* how about ::ffff:0.0.0.0 case? */
 214                         error = EISCONN;
 215                         goto release;
 216                 }
 217
 218                 /* protect *sin6 from overwrites */
 219                 tmp = *sin6;
 220                 sin6 = &tmp;
 221
 222                 faddr = &sin6->sin6_addr;
 223                 fport = sin6->sin6_port; /* allow 0 port */
 224
 225                 if (IN6_IS_ADDR_V4MAPPED(faddr)) {
 226                         if ((in6p->in6p_flags & IN6P_IPV6_V6ONLY)) {
 227                                 /*
 228                                  * I believe we should explicitly discard the
 229                                  * packet when mapped addresses are disabled,
 230                                  * rather than send the packet as an IPv6 one.
 231                                  * If we chose the latter approach, the packet
 232                                  * might be sent out on the wire based on the
 233                                  * default route, the situation which we'd
 234                                  * probably want to avoid.
 235                                  * (20010421 jinmei@kame.net)
 236                                  */
 237                                 error = EINVAL;
 238                                 goto release;
 239                         } else {
 240                                 af = AF_INET;
 241                         }
 242                 }
 243
 244                 /* KAME hack: embed scopeid */
 245                 if (in6_embedscope(&sin6->sin6_addr, sin6, in6p, NULL,
 246                     optp) != 0) {
 247                         error = EINVAL;
 248                         goto release;
 249                 }
 250
 251                 if (!IN6_IS_ADDR_V4MAPPED(faddr)) {
 252                         laddr = in6_selectsrc(sin6, optp,
 253                             in6p, &in6p->in6p_route, NULL, &storage,
 254                             ip6oa.ip6oa_boundif, &error);
 255                 } else
 256                         laddr = &in6p->in6p_laddr;      /* XXX */
 257                 if (laddr == NULL) {
 258                         if (error == 0)
 259                                 error = EADDRNOTAVAIL;
 260                         goto release;
 261                 }
 262                 if (in6p->in6p_lport == 0 &&
 263                     (error = in6_pcbsetport(laddr, in6p, p, 0)) != 0)
 264                         goto release;
 265         } else {
 266                 if (IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
 267                         error = ENOTCONN;
 268                         goto release;
 269                 }
 270                 if (IN6_IS_ADDR_V4MAPPED(&in6p->in6p_faddr)) {
 271                         if ((in6p->in6p_flags & IN6P_IPV6_V6ONLY)) {
 272                                 /*
 273                                  * XXX: this case would happen when the
 274                                  * application sets the V6ONLY flag after
 275                                  * connecting the foreign address.
 276                                  * Such applications should be fixed,
 277                                  * so we bark here.
 278                                  */
 279                                 log(LOG_INFO, "udp6_output: IPV6_V6ONLY "
 280                                     "option was set for a connected socket\n");
 281                                 error = EINVAL;
 282                                 goto release;
 283                         } else
 284                                 af = AF_INET;
 285                 }
 286                 laddr = &in6p->in6p_laddr;
 287                 faddr = &in6p->in6p_faddr;
 288                 fport = in6p->in6p_fport;
 289         }
 290
 291         if (in6p->inp_flowhash == 0)
 292                 in6p->inp_flowhash = inp_calc_flowhash(in6p);
 293         /* update flowinfo - RFC 6437 */
 294         if (in6p->inp_flow == 0 && in6p->in6p_flags & IN6P_AUTOFLOWLABEL) {
 295                 in6p->inp_flow &= ~IPV6_FLOWLABEL_MASK;
 296                 in6p->inp_flow |=
 297                     (htonl(in6p->inp_flowhash) & IPV6_FLOWLABEL_MASK);
 298         }
 299
 300         if (af == AF_INET)
 301                 hlen = sizeof (struct ip);
 302
 303         /*
 304          * Calculate data length and get a mbuf
 305          * for UDP and IP6 headers.
 306          */
 307         M_PREPEND(m, hlen + sizeof (struct udphdr), M_DONTWAIT);
 308         if (m == 0) {
 309                 error = ENOBUFS;
 310                 goto release;
 311         }
 312
 313         /*
 314          * Stuff checksum and output datagram.
 315          */
 316         udp6 = (struct udphdr *)(void *)(mtod(m, caddr_t) + hlen);
 317         udp6->uh_sport = in6p->in6p_lport; /* lport is always set in the PCB */
 318         udp6->uh_dport = fport;
 319         if (plen <= 0xffff)
 320                 udp6->uh_ulen = htons((u_short)plen);
 321         else
 322                 udp6->uh_ulen = 0;
 323         udp6->uh_sum = 0;
 324
 325         switch (af) {
 326         case AF_INET6:
 327                 ip6 = mtod(m, struct ip6_hdr *);
 328                 ip6->ip6_flow   = in6p->inp_flow & IPV6_FLOWINFO_MASK;
 329                 ip6->ip6_vfc    &= ~IPV6_VERSION_MASK;
 330                 ip6->ip6_vfc    |= IPV6_VERSION;
 331 #if 0           /* ip6_plen will be filled in ip6_output. */
 332                 ip6->ip6_plen   = htons((u_short)plen);
 333 #endif
 334                 ip6->ip6_nxt    = IPPROTO_UDP;
 335                 ip6->ip6_hlim   = in6_selecthlim(in6p, in6p->in6p_route.ro_rt ?
 336                     in6p->in6p_route.ro_rt->rt_ifp : NULL);
 337                 ip6->ip6_src    = *laddr;
 338                 ip6->ip6_dst    = *faddr;
 339
 340                 udp6->uh_sum = in6_pseudo(laddr, faddr,
 341                     htonl(plen + IPPROTO_UDP));
 342                 m->m_pkthdr.csum_flags = CSUM_UDPIPV6;
 343                 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
 344
 345                 if (!IN6_IS_ADDR_UNSPECIFIED(laddr))
 346                         ip6oa.ip6oa_flags |= IP6OAF_BOUND_SRCADDR;
 347
 348                 flags = IPV6_OUTARGS;
 349
 350                 udp6stat.udp6s_opackets++;
 351 #if IPSEC
 352                 if (ipsec_bypass == 0 && ipsec_setsocket(m, so) != 0) {
 353                         error = ENOBUFS;
 354                         goto release;
 355                 }
 356 #endif /* IPSEC */
 357
 358                 /* In case of IPv4-mapped address used in previous send */
 359                 if (ROUTE_UNUSABLE(&in6p->in6p_route) ||
 360                     rt_key(in6p->in6p_route.ro_rt)->sa_family != AF_INET6)
 361                         ROUTE_RELEASE(&in6p->in6p_route);
 362
 363                 /* Copy the cached route and take an extra reference */
 364                 in6p_route_copyout(in6p, &ro);
 365
 366                 set_packet_service_class(m, so, msc, PKT_SCF_IPV6);
 367
 368                 m->m_pkthdr.pkt_flowsrc = FLOWSRC_INPCB;
 369                 m->m_pkthdr.pkt_flowid = in6p->inp_flowhash;
 370                 m->m_pkthdr.pkt_proto = IPPROTO_UDP;
 371                 m->m_pkthdr.pkt_flags |= (PKTF_FLOW_ID | PKTF_FLOW_LOCALSRC);
 372                 if (flowadv)
 373                         m->m_pkthdr.pkt_flags |= PKTF_FLOW_ADV;
 374
 375                 im6o = in6p->in6p_moptions;
 376                 if (im6o != NULL) {
 377                         IM6O_LOCK(im6o);
 378                         IM6O_ADDREF_LOCKED(im6o);
 379                         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
 380                             im6o->im6o_multicast_ifp != NULL) {
 381                                 in6p->in6p_last_outifp =
 382                                     im6o->im6o_multicast_ifp;
 383                         }
 384                         IM6O_UNLOCK(im6o);
 385                 }
 386
 387                 in6p->inp_sndinprog_cnt++;
 388
 389                 socket_unlock(so, 0);
 390                 error = ip6_output(m, optp, &ro, flags, im6o, NULL, &ip6oa);
 391                 m = NULL;
 392                 socket_lock(so, 0);
 393
 394                 if (im6o != NULL)
 395                         IM6O_REMREF(im6o);
 396
 397                 if (error == 0 && nstat_collect) {
 398                         boolean_t cell, wifi;
 399
 400                         if (in6p->in6p_route.ro_rt != NULL) {
 401                                 cell = IFNET_IS_CELLULAR(in6p->in6p_route.
 402                                     ro_rt->rt_ifp);
 403                                 wifi = (!cell && IFNET_IS_WIFI(in6p->in6p_route.
 404                                     ro_rt->rt_ifp));
 405                         } else {
 406                                 cell = wifi = FALSE;
 407                         }
 408                         INP_ADD_STAT(in6p, cell, wifi, txpackets, 1);
 409                         INP_ADD_STAT(in6p, cell, wifi, txbytes, ulen);
 410                 }
 411
 412                 if (flowadv && (adv->code == FADV_FLOW_CONTROLLED ||
 413                     adv->code == FADV_SUSPENDED)) {
 414                         /*
 415                          * Return an error to indicate
 416                          * that the packet has been dropped.
 417                          */
 418                         error = ENOBUFS;
 419                         inp_set_fc_state(in6p, adv->code);
 420                 }
 421
 422                 VERIFY(in6p->inp_sndinprog_cnt > 0);
 423                 if ( --in6p->inp_sndinprog_cnt == 0)
 424                         in6p->inp_flags &= ~(INP_FC_FEEDBACK);
 425
 426                 /* Synchronize PCB cached route */
 427                 in6p_route_copyin(in6p, &ro);
 428
 429                 if (in6p->in6p_route.ro_rt != NULL) {
 430                         struct rtentry *rt = in6p->in6p_route.ro_rt;
 431                         struct ifnet *outif;
 432
 433                         if (rt->rt_flags & RTF_MULTICAST)
 434                                 rt = NULL;      /* unusable */
 435
 436                         /*
 437                          * Always discard the cached route for unconnected
 438                          * socket or if it is a multicast route.
 439                          */
 440                         if (rt == NULL)
 441                                 ROUTE_RELEASE(&in6p->in6p_route);
 442
 443                         /*
 444                          * If the destination route is unicast, update outif
 445                          * with that of the route interface used by IP.
 446                          */
 447                         if (rt != NULL &&
 448                             (outif = rt->rt_ifp) != in6p->in6p_last_outifp)
 449                                 in6p->in6p_last_outifp = outif;
 450                 } else {
 451                         ROUTE_RELEASE(&in6p->in6p_route);
 452                 }
 453
 454                 /*
 455                  * If output interface was cellular, and this socket is
 456                  * denied access to it, generate an event.
 457                  */
 458                 if (error != 0 && (ip6oa.ip6oa_retflags & IP6OARF_IFDENIED) &&
 459                     (in6p->inp_flags & INP_NO_IFT_CELLULAR))
 460                         soevent(in6p->inp_socket, (SO_FILT_HINT_LOCKED|
 461                             SO_FILT_HINT_IFDENIED));
 462                 break;
 463         case AF_INET:
 464                 error = EAFNOSUPPORT;
 465                 goto release;
 466         }
 467         goto releaseopt;
 468
 469 release:
 470         if (m != NULL)
 471                 m_freem(m);
 472
 473 releaseopt:
 474         if (control != NULL) {
 475                 if (optp == &opt)
 476                         ip6_clearpktopts(optp, -1);
 477                 m_freem(control);
 478         }
 479         return (error);
 480 }