sys/netinet6/udp6_output.c

   1 /*      $NetBSD: udp6_output.c,v 1.36 2008/05/13 17:53:52 dyoung Exp $  */
   2 /*      $KAME: udp6_output.c,v 1.43 2001/10/15 09:19:52 itojun Exp $    */
   3
   4 /*
   5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the project nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 /*
  34  * Copyright (c) 1982, 1986, 1989, 1993
  35  *      The Regents of the University of California.  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 University 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 REGENTS 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 REGENTS 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  *      @(#)udp_var.h   8.1 (Berkeley) 6/10/93
  62  */
  63
  64 #include <sys/cdefs.h>
  65 __KERNEL_RCSID(0, "$NetBSD: udp6_output.c,v 1.36 2008/05/13 17:53:52 dyoung Exp $");
  66
  67 #include "opt_inet.h"
  68
  69 #include <sys/param.h>
  70 #include <sys/malloc.h>
  71 #include <sys/mbuf.h>
  72 #include <sys/protosw.h>
  73 #include <sys/socket.h>
  74 #include <sys/socketvar.h>
  75 #include <sys/errno.h>
  76 #include <sys/stat.h>
  77 #include <sys/systm.h>
  78 #include <sys/proc.h>
  79 #include <sys/syslog.h>
  80 #include <sys/kauth.h>
  81
  82 #include <net/if.h>
  83 #include <net/route.h>
  84 #include <net/if_types.h>
  85
  86 #include <netinet/in.h>
  87 #include <netinet/in_var.h>
  88 #include <netinet/in_systm.h>
  89 #include <netinet/ip.h>
  90 #include <netinet/ip_var.h>
  91 #include <netinet/in_pcb.h>
  92 #include <netinet/udp.h>
  93 #include <netinet/udp_var.h>
  94 #include <netinet/udp_private.h>
  95 #include <netinet/ip6.h>
  96 #include <netinet6/ip6_var.h>
  97 #include <netinet6/in6_pcb.h>
  98 #include <netinet6/udp6_var.h>
  99 #include <netinet6/udp6_private.h>
 100 #include <netinet/icmp6.h>
 101 #include <netinet6/ip6protosw.h>
 102 #include <netinet6/scope6_var.h>
 103
 104 #include "faith.h"
 105
 106 #include <net/net_osdep.h>
 107
 108 /*
 109  * UDP protocol inplementation.
 110  * Per RFC 768, August, 1980.
 111  */
 112
 113 int
 114 udp6_output(struct in6pcb *in6p, struct mbuf *m, struct mbuf *addr6,
 115         struct mbuf *control, struct lwp *l)
 116 {
 117         struct rtentry *rt;
 118         u_int32_t ulen = m->m_pkthdr.len;
 119         u_int32_t plen = sizeof(struct udphdr) + ulen;
 120         struct ip6_hdr *ip6;
 121         struct udphdr *udp6;
 122         struct in6_addr *laddr, *faddr;
 123         struct in6_addr laddr_mapped; /* XXX ugly */
 124         struct sockaddr_in6 *sin6 = NULL;
 125         struct ifnet *oifp = NULL;
 126         int scope_ambiguous = 0;
 127         u_int16_t fport;
 128         int error = 0;
 129         struct ip6_pktopts *optp, opt;
 130         int priv;
 131         int af = AF_INET6, hlen = sizeof(struct ip6_hdr);
 132 #ifdef INET
 133         struct ip *ip;
 134         struct udpiphdr *ui;
 135         int flags = 0;
 136 #endif
 137         struct sockaddr_in6 tmp;
 138
 139         priv = 0;
 140         if (l && !kauth_authorize_generic(l->l_cred, KAUTH_GENERIC_ISSUSER,
 141             NULL))
 142                 priv = 1;
 143
 144         if (addr6) {
 145                 if (addr6->m_len != sizeof(*sin6)) {
 146                         error = EINVAL;
 147                         goto release;
 148                 }
 149                 sin6 = mtod(addr6, struct sockaddr_in6 *);
 150                 if (sin6->sin6_family != AF_INET6) {
 151                         error = EAFNOSUPPORT;
 152                         goto release;
 153                 }
 154
 155                 /* protect *sin6 from overwrites */
 156                 tmp = *sin6;
 157                 sin6 = &tmp;
 158
 159                 /*
 160                  * Application should provide a proper zone ID or the use of
 161                  * default zone IDs should be enabled.  Unfortunately, some
 162                  * applications do not behave as it should, so we need a
 163                  * workaround.  Even if an appropriate ID is not determined,
 164                  * we'll see if we can determine the outgoing interface.  If we
 165                  * can, determine the zone ID based on the interface below.
 166                  */
 167                 if (sin6->sin6_scope_id == 0 && !ip6_use_defzone)
 168                         scope_ambiguous = 1;
 169                 if ((error = sa6_embedscope(sin6, ip6_use_defzone)) != 0)
 170                         return (error);
 171         }
 172
 173         if (control) {
 174                 if ((error = ip6_setpktopts(control, &opt,
 175                     in6p->in6p_outputopts, priv, IPPROTO_UDP)) != 0)
 176                         goto release;
 177                 optp = &opt;
 178         } else
 179                 optp = in6p->in6p_outputopts;
 180
 181
 182         if (sin6) {
 183                 faddr = &sin6->sin6_addr;
 184
 185                 /*
 186                  * IPv4 version of udp_output calls in_pcbconnect in this case,
 187                  * which needs splnet and affects performance.
 188                  * Since we saw no essential reason for calling in_pcbconnect,
 189                  * we get rid of such kind of logic, and call in6_selectsrc
 190                  * and in6_pcbsetport in order to fill in the local address
 191                  * and the local port.
 192                  */
 193                 if (sin6->sin6_port == 0) {
 194                         error = EADDRNOTAVAIL;
 195                         goto release;
 196                 }
 197
 198                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
 199                         /* how about ::ffff:0.0.0.0 case? */
 200                         error = EISCONN;
 201                         goto release;
 202                 }
 203
 204
 205                 faddr = &sin6->sin6_addr;
 206                 fport = sin6->sin6_port; /* allow 0 port */
 207
 208                 if (IN6_IS_ADDR_V4MAPPED(faddr)) {
 209                         if ((in6p->in6p_flags & IN6P_IPV6_V6ONLY))
 210                         {
 211                                 /*
 212                                  * I believe we should explicitly discard the
 213                                  * packet when mapped addresses are disabled,
 214                                  * rather than send the packet as an IPv6 one.
 215                                  * If we chose the latter approach, the packet
 216                                  * might be sent out on the wire based on the
 217                                  * default route, the situation which we'd
 218                                  * probably want to avoid.
 219                                  * (20010421 jinmei@kame.net)
 220                                  */
 221                                 error = EINVAL;
 222                                 goto release;
 223                         }
 224                         if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)
 225                             && !IN6_IS_ADDR_V4MAPPED(&in6p->in6p_laddr)) {
 226                                 /*
 227                                  * when remote addr is an IPv4-mapped address,
 228                                  * local addr should not be an IPv6 address,
 229                                  * since you cannot determine how to map IPv6
 230                                  * source address to IPv4.
 231                                  */
 232                                 error = EINVAL;
 233                                 goto release;
 234                         }
 235
 236                         af = AF_INET;
 237                 }
 238
 239                 if (!IN6_IS_ADDR_V4MAPPED(faddr)) {
 240                         laddr = in6_selectsrc(sin6, optp,
 241                             in6p->in6p_moptions,
 242                             &in6p->in6p_route,
 243                             &in6p->in6p_laddr, &oifp, &error);
 244                         if (oifp && scope_ambiguous &&
 245                             (error = in6_setscope(&sin6->sin6_addr,
 246                             oifp, NULL))) {
 247                                 goto release;
 248                         }
 249                 } else {
 250                         /*
 251                          * XXX: freebsd[34] does not have in_selectsrc, but
 252                          * we can omit the whole part because freebsd4 calls
 253                          * udp_output() directly in this case, and thus we'll
 254                          * never see this path.
 255                          */
 256                         if (IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
 257                                 struct sockaddr_in *sinp, sin_dst;
 258                                 struct in_addr ina;
 259
 260                                 memcpy(&ina, &faddr->s6_addr[12], sizeof(ina));
 261                                 sockaddr_in_init(&sin_dst, &ina, 0);
 262                                 sinp = in_selectsrc(&sin_dst, &in6p->in6p_route,
 263                                     in6p->in6p_socket->so_options, NULL,
 264                                     &error);
 265                                 if (sinp == NULL) {
 266                                         if (error == 0)
 267                                                 error = EADDRNOTAVAIL;
 268                                         goto release;
 269                                 }
 270                                 memset(&laddr_mapped, 0, sizeof(laddr_mapped));
 271                                 laddr_mapped.s6_addr16[5] = 0xffff; /* ugly */
 272                                 memcpy(&laddr_mapped.s6_addr[12],
 273                                       &sinp->sin_addr,
 274                                       sizeof(sinp->sin_addr));
 275                                 laddr = &laddr_mapped;
 276                         } else
 277                         {
 278                                 laddr = &in6p->in6p_laddr;      /* XXX */
 279                         }
 280                 }
 281                 if (laddr == NULL) {
 282                         if (error == 0)
 283                                 error = EADDRNOTAVAIL;
 284                         goto release;
 285                 }
 286                 if (in6p->in6p_lport == 0 &&
 287                     (error = in6_pcbsetport(laddr, in6p, l)) != 0)
 288                         goto release;
 289         } else {
 290                 if (IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
 291                         error = ENOTCONN;
 292                         goto release;
 293                 }
 294                 if (IN6_IS_ADDR_V4MAPPED(&in6p->in6p_faddr)) {
 295                         if ((in6p->in6p_flags & IN6P_IPV6_V6ONLY))
 296                         {
 297                                 /*
 298                                  * XXX: this case would happen when the
 299                                  * application sets the V6ONLY flag after
 300                                  * connecting the foreign address.
 301                                  * Such applications should be fixed,
 302                                  * so we bark here.
 303                                  */
 304                                 log(LOG_INFO, "udp6_output: IPV6_V6ONLY "
 305                                     "option was set for a connected socket\n");
 306                                 error = EINVAL;
 307                                 goto release;
 308                         } else
 309                                 af = AF_INET;
 310                 }
 311                 laddr = &in6p->in6p_laddr;
 312                 faddr = &in6p->in6p_faddr;
 313                 fport = in6p->in6p_fport;
 314         }
 315
 316         if (af == AF_INET)
 317                 hlen = sizeof(struct ip);
 318
 319         /*
 320          * Calculate data length and get a mbuf
 321          * for UDP and IP6 headers.
 322          */
 323         M_PREPEND(m, hlen + sizeof(struct udphdr), M_DONTWAIT);
 324         if (m == 0) {
 325                 error = ENOBUFS;
 326                 goto release;
 327         }
 328
 329         /*
 330          * Stuff checksum and output datagram.
 331          */
 332         udp6 = (struct udphdr *)(mtod(m, char *) + hlen);
 333         udp6->uh_sport = in6p->in6p_lport; /* lport is always set in the PCB */
 334         udp6->uh_dport = fport;
 335         if (plen <= 0xffff)
 336                 udp6->uh_ulen = htons((u_int16_t)plen);
 337         else
 338                 udp6->uh_ulen = 0;
 339         udp6->uh_sum = 0;
 340
 341         switch (af) {
 342         case AF_INET6:
 343                 ip6 = mtod(m, struct ip6_hdr *);
 344                 ip6->ip6_flow   = in6p->in6p_flowinfo & IPV6_FLOWINFO_MASK;
 345                 ip6->ip6_vfc    &= ~IPV6_VERSION_MASK;
 346                 ip6->ip6_vfc    |= IPV6_VERSION;
 347 #if 0                           /* ip6_plen will be filled in ip6_output. */
 348                 ip6->ip6_plen   = htons((u_int16_t)plen);
 349 #endif
 350                 ip6->ip6_nxt    = IPPROTO_UDP;
 351                 ip6->ip6_hlim   = in6_selecthlim(in6p,
 352                     (rt = rtcache_validate(&in6p->in6p_route)) != NULL
 353                         ? rt->rt_ifp : NULL);
 354                 ip6->ip6_src    = *laddr;
 355                 ip6->ip6_dst    = *faddr;
 356
 357                 udp6->uh_sum = in6_cksum_phdr(laddr, faddr,
 358                     htonl(plen), htonl(IPPROTO_UDP));
 359                 m->m_pkthdr.csum_flags = M_CSUM_UDPv6;
 360                 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
 361
 362                 UDP6_STATINC(UDP6_STAT_OPACKETS);
 363                 error = ip6_output(m, optp, &in6p->in6p_route, 0,
 364                     in6p->in6p_moptions, in6p->in6p_socket, NULL);
 365                 break;
 366         case AF_INET:
 367 #ifdef INET
 368                 /* can't transmit jumbogram over IPv4 */
 369                 if (plen > 0xffff) {
 370                         error = EMSGSIZE;
 371                         goto release;
 372                 }
 373
 374                 ip = mtod(m, struct ip *);
 375                 ui = (struct udpiphdr *)ip;
 376                 memset(ui->ui_x1, 0, sizeof(ui->ui_x1));
 377                 ui->ui_pr = IPPROTO_UDP;
 378                 ui->ui_len = htons(plen);
 379                 memcpy(&ui->ui_src, &laddr->s6_addr[12], sizeof(ui->ui_src));
 380                 ui->ui_ulen = ui->ui_len;
 381
 382                 flags = (in6p->in6p_socket->so_options &
 383                          (SO_DONTROUTE | SO_BROADCAST));
 384                 memcpy(&ui->ui_dst, &faddr->s6_addr[12], sizeof(ui->ui_dst));
 385
 386                 udp6->uh_sum = in_cksum(m, hlen + plen);
 387                 if (udp6->uh_sum == 0)
 388                         udp6->uh_sum = 0xffff;
 389
 390                 ip->ip_len = htons(hlen + plen);
 391                 ip->ip_ttl = in6_selecthlim(in6p, NULL); /* XXX */
 392                 ip->ip_tos = 0; /* XXX */
 393
 394                 UDP_STATINC(UDP_STAT_OPACKETS);
 395                 error = ip_output(m, NULL, &in6p->in6p_route, flags /* XXX */,
 396                     (struct ip_moptions *)NULL,
 397                     (struct socket *)in6p->in6p_socket);
 398                 break;
 399 #else
 400                 error = EAFNOSUPPORT;
 401                 goto release;
 402 #endif
 403         }
 404         goto releaseopt;
 405
 406 release:
 407         m_freem(m);
 408
 409 releaseopt:
 410         if (control) {
 411                 ip6_clearpktopts(&opt, -1);
 412                 m_freem(control);
 413         }
 414         return (error);
 415 }