sys/netipx/ipx_input.c

   1 /*
   2  * Copyright (c) 1995, Mike Mitchell
   3  * Copyright (c) 1984, 1985, 1986, 1987, 1993
   4  *      The Regents of the University of California.  All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. All advertising materials mentioning features or use of this software
  15  *    must display the following acknowledgement:
  16  *      This product includes software developed by the University of
  17  *      California, Berkeley and its contributors.
  18  * 4. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  *      @(#)ipx_input.c
  35  */
  36
  37 #include <sys/cdefs.h>
  38 __FBSDID("$FreeBSD$");
  39
  40 #include <sys/param.h>
  41 #include <sys/systm.h>
  42 #include <sys/mbuf.h>
  43 #include <sys/protosw.h>
  44 #include <sys/socket.h>
  45 #include <sys/kernel.h>
  46 #include <sys/random.h>
  47 #include <sys/sysctl.h>
  48
  49 #include <net/if.h>
  50 #include <net/route.h>
  51 #include <net/netisr.h>
  52
  53 #include <netipx/ipx.h>
  54 #include <netipx/spx.h>
  55 #include <netipx/ipx_if.h>
  56 #include <netipx/ipx_pcb.h>
  57 #include <netipx/ipx_var.h>
  58
  59 int     ipxcksum = 0;
  60 SYSCTL_INT(_net_ipx_ipx, OID_AUTO, checksum, CTLFLAG_RW,
  61            &ipxcksum, 0, "");
  62
  63 static int      ipxprintfs = 0;         /* printing forwarding information */
  64 SYSCTL_INT(_net_ipx_ipx, OID_AUTO, ipxprintfs, CTLFLAG_RW,
  65            &ipxprintfs, 0, "");
  66
  67 static int      ipxforwarding = 0;
  68 SYSCTL_INT(_net_ipx_ipx, OID_AUTO, ipxforwarding, CTLFLAG_RW,
  69             &ipxforwarding, 0, "");
  70
  71 static int      ipxnetbios = 0;
  72 SYSCTL_INT(_net_ipx, OID_AUTO, ipxnetbios, CTLFLAG_RW,
  73            &ipxnetbios, 0, "");
  74
  75 union   ipx_net ipx_zeronet;
  76 union   ipx_host ipx_zerohost;
  77
  78 union   ipx_net ipx_broadnet;
  79 union   ipx_host ipx_broadhost;
  80
  81 struct  ipxstat ipxstat;
  82 struct  sockaddr_ipx ipx_netmask, ipx_hostmask;
  83
  84 static  u_short allones[] = {-1, -1, -1};
  85
  86 struct  ipxpcb ipxpcb;
  87 struct  ipxpcb ipxrawpcb;
  88
  89 static int ipxqmaxlen = IFQ_MAXLEN;
  90 static  struct ifqueue ipxintrq;
  91
  92 long    ipx_pexseq;
  93
  94 static  int ipx_do_route(struct ipx_addr *src, struct route *ro);
  95 static  void ipx_undo_route(struct route *ro);
  96 static  void ipx_forward(struct mbuf *m);
  97 static  void ipxintr(struct mbuf *m);
  98
  99 /*
 100  * IPX initialization.
 101  */
 102
 103 void
 104 ipx_init()
 105 {
 106         ipx_broadnet = *(union ipx_net *)allones;
 107         ipx_broadhost = *(union ipx_host *)allones;
 108
 109         read_random(&ipx_pexseq, sizeof ipx_pexseq);
 110         ipxpcb.ipxp_next = ipxpcb.ipxp_prev = &ipxpcb;
 111         ipxrawpcb.ipxp_next = ipxrawpcb.ipxp_prev = &ipxrawpcb;
 112
 113         ipx_netmask.sipx_len = 6;
 114         ipx_netmask.sipx_addr.x_net = ipx_broadnet;
 115
 116         ipx_hostmask.sipx_len = 12;
 117         ipx_hostmask.sipx_addr.x_net = ipx_broadnet;
 118         ipx_hostmask.sipx_addr.x_host = ipx_broadhost;
 119
 120         ipxintrq.ifq_maxlen = ipxqmaxlen;
 121         mtx_init(&ipxintrq.ifq_mtx, "ipx_inq", NULL, MTX_DEF);
 122         netisr_register(NETISR_IPX, ipxintr, &ipxintrq, 0);
 123 }
 124
 125 /*
 126  * IPX input routine.  Pass to next level.
 127  */
 128 static void
 129 ipxintr(struct mbuf *m)
 130 {
 131         register struct ipx *ipx;
 132         register struct ipxpcb *ipxp;
 133         struct ipx_ifaddr *ia;
 134         int len;
 135
 136         GIANT_REQUIRED;
 137
 138         /*
 139          * If no IPX addresses have been set yet but the interfaces
 140          * are receiving, can't do anything with incoming packets yet.
 141          */
 142         if (ipx_ifaddr == NULL)
 143                 goto bad;
 144
 145         ipxstat.ipxs_total++;
 146
 147         if ((m->m_flags & M_EXT || m->m_len < sizeof(struct ipx)) &&
 148             (m = m_pullup(m, sizeof(struct ipx))) == 0) {
 149                 ipxstat.ipxs_toosmall++;
 150                 return;
 151         }
 152
 153         /*
 154          * Give any raw listeners a crack at the packet
 155          */
 156         for (ipxp = ipxrawpcb.ipxp_next; ipxp != &ipxrawpcb;
 157              ipxp = ipxp->ipxp_next) {
 158                 struct mbuf *m1 = m_copy(m, 0, (int)M_COPYALL);
 159                 if (m1 != NULL)
 160                         ipx_input(m1, ipxp);
 161         }
 162
 163         ipx = mtod(m, struct ipx *);
 164         len = ntohs(ipx->ipx_len);
 165         /*
 166          * Check that the amount of data in the buffers
 167          * is as at least much as the IPX header would have us expect.
 168          * Trim mbufs if longer than we expect.
 169          * Drop packet if shorter than we expect.
 170          */
 171         if (m->m_pkthdr.len < len) {
 172                 ipxstat.ipxs_tooshort++;
 173                 goto bad;
 174         }
 175         if (m->m_pkthdr.len > len) {
 176                 if (m->m_len == m->m_pkthdr.len) {
 177                         m->m_len = len;
 178                         m->m_pkthdr.len = len;
 179                 } else
 180                         m_adj(m, len - m->m_pkthdr.len);
 181         }
 182         if (ipxcksum && ipx->ipx_sum != 0xffff) {
 183                 if (ipx->ipx_sum != ipx_cksum(m, len)) {
 184                         ipxstat.ipxs_badsum++;
 185                         goto bad;
 186                 }
 187         }
 188
 189         /*
 190          * Propagated (Netbios) packets (type 20) has to be handled
 191          * different. :-(
 192          */
 193         if (ipx->ipx_pt == IPXPROTO_NETBIOS) {
 194                 if (ipxnetbios) {
 195                         ipx_output_type20(m);
 196                         return;
 197                 } else
 198                         goto bad;
 199         }
 200
 201         /*
 202          * Is this a directed broadcast?
 203          */
 204         if (ipx_hosteqnh(ipx_broadhost,ipx->ipx_dna.x_host)) {
 205                 if ((!ipx_neteq(ipx->ipx_dna, ipx->ipx_sna)) &&
 206                     (!ipx_neteqnn(ipx->ipx_dna.x_net, ipx_broadnet)) &&
 207                     (!ipx_neteqnn(ipx->ipx_sna.x_net, ipx_zeronet)) &&
 208                     (!ipx_neteqnn(ipx->ipx_dna.x_net, ipx_zeronet)) ) {
 209                         /*
 210                          * If it is a broadcast to the net where it was
 211                          * received from, treat it as ours.
 212                          */
 213                         for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
 214                                 if((ia->ia_ifa.ifa_ifp == m->m_pkthdr.rcvif) &&
 215                                    ipx_neteq(ia->ia_addr.sipx_addr,
 216                                              ipx->ipx_dna))
 217                                         goto ours;
 218
 219                         /*
 220                          * Look to see if I need to eat this packet.
 221                          * Algorithm is to forward all young packets
 222                          * and prematurely age any packets which will
 223                          * by physically broadcasted.
 224                          * Any very old packets eaten without forwarding
 225                          * would die anyway.
 226                          *
 227                          * Suggestion of Bill Nesheim, Cornell U.
 228                          */
 229                         if (ipx->ipx_tc < IPX_MAXHOPS) {
 230                                 ipx_forward(m);
 231                                 return;
 232                         }
 233                 }
 234         /*
 235          * Is this our packet? If not, forward.
 236          */
 237         } else {
 238                 for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
 239                         if (ipx_hosteq(ipx->ipx_dna, ia->ia_addr.sipx_addr) &&
 240                             (ipx_neteq(ipx->ipx_dna, ia->ia_addr.sipx_addr) ||
 241                              ipx_neteqnn(ipx->ipx_dna.x_net, ipx_zeronet)))
 242                                 break;
 243
 244                 if (ia == NULL) {
 245                         ipx_forward(m);
 246                         return;
 247                 }
 248         }
 249 ours:
 250         /*
 251          * Locate pcb for datagram.
 252          */
 253         ipxp = ipx_pcblookup(&ipx->ipx_sna, ipx->ipx_dna.x_port, IPX_WILDCARD);
 254         /*
 255          * Switch out to protocol's input routine.
 256          */
 257         if (ipxp != NULL) {
 258                 ipxstat.ipxs_delivered++;
 259                 if ((ipxp->ipxp_flags & IPXP_ALL_PACKETS) == 0)
 260                         switch (ipx->ipx_pt) {
 261                         case IPXPROTO_SPX:
 262                                 spx_input(m, ipxp);
 263                                 return;
 264                         }
 265                 ipx_input(m, ipxp);
 266         } else
 267                 goto bad;
 268
 269         return;
 270
 271 bad:
 272         m_freem(m);
 273 }
 274
 275 void
 276 ipx_ctlinput(cmd, arg_as_sa, dummy)
 277         int cmd;
 278         struct sockaddr *arg_as_sa;     /* XXX should be swapped with dummy */
 279         void *dummy;
 280 {
 281         caddr_t arg = (/* XXX */ caddr_t)arg_as_sa;
 282         struct ipx_addr *ipx;
 283
 284         if (cmd < 0 || cmd >= PRC_NCMDS)
 285                 return;
 286         switch (cmd) {
 287                 struct sockaddr_ipx *sipx;
 288
 289         case PRC_IFDOWN:
 290         case PRC_HOSTDEAD:
 291         case PRC_HOSTUNREACH:
 292                 sipx = (struct sockaddr_ipx *)arg;
 293                 if (sipx->sipx_family != AF_IPX)
 294                         return;
 295                 ipx = &sipx->sipx_addr;
 296                 break;
 297
 298         default:
 299                 if (ipxprintfs)
 300                         printf("ipx_ctlinput: cmd %d.\n", cmd);
 301                 break;
 302         }
 303 }
 304
 305 /*
 306  * Forward a packet. If some error occurs drop the packet. IPX don't
 307  * have a way to return errors to the sender.
 308  */
 309
 310 static struct route ipx_droute;
 311 static struct route ipx_sroute;
 312
 313 static void
 314 ipx_forward(m)
 315 struct mbuf *m;
 316 {
 317         register struct ipx *ipx = mtod(m, struct ipx *);
 318         register int error;
 319         struct mbuf *mcopy = NULL;
 320         int agedelta = 1;
 321         int flags = IPX_FORWARDING;
 322         int ok_there = 0;
 323         int ok_back = 0;
 324
 325         if (ipxforwarding == 0) {
 326                 /* can't tell difference between net and host */
 327                 ipxstat.ipxs_cantforward++;
 328                 m_freem(m);
 329                 goto cleanup;
 330         }
 331         ipx->ipx_tc++;
 332         if (ipx->ipx_tc > IPX_MAXHOPS) {
 333                 ipxstat.ipxs_cantforward++;
 334                 m_freem(m);
 335                 goto cleanup;
 336         }
 337
 338         if ((ok_there = ipx_do_route(&ipx->ipx_dna,&ipx_droute)) == 0) {
 339                 ipxstat.ipxs_noroute++;
 340                 m_freem(m);
 341                 goto cleanup;
 342         }
 343         /*
 344          * Here we think about  forwarding  broadcast packets,
 345          * so we try to insure that it doesn't go back out
 346          * on the interface it came in on.  Also, if we
 347          * are going to physically broadcast this, let us
 348          * age the packet so we can eat it safely the second time around.
 349          */
 350         if (ipx->ipx_dna.x_host.c_host[0] & 0x1) {
 351                 struct ipx_ifaddr *ia = ipx_iaonnetof(&ipx->ipx_dna);
 352                 struct ifnet *ifp;
 353                 if (ia != NULL) {
 354                         /* I'm gonna hafta eat this packet */
 355                         agedelta += IPX_MAXHOPS - ipx->ipx_tc;
 356                         ipx->ipx_tc = IPX_MAXHOPS;
 357                 }
 358                 if ((ok_back = ipx_do_route(&ipx->ipx_sna,&ipx_sroute)) == 0) {
 359                         /* error = ENETUNREACH; He'll never get it! */
 360                         ipxstat.ipxs_noroute++;
 361                         m_freem(m);
 362                         goto cleanup;
 363                 }
 364                 if (ipx_droute.ro_rt &&
 365                     (ifp = ipx_droute.ro_rt->rt_ifp) &&
 366                     ipx_sroute.ro_rt &&
 367                     (ifp != ipx_sroute.ro_rt->rt_ifp)) {
 368                         flags |= IPX_ALLOWBROADCAST;
 369                 } else {
 370                         ipxstat.ipxs_noroute++;
 371                         m_freem(m);
 372                         goto cleanup;
 373                 }
 374         }
 375         /*
 376          * We don't need to recompute checksum because ipx_tc field
 377          * is ignored by checksum calculation routine, however
 378          * it may be desirable to reset checksum if ipxcksum == 0
 379          */
 380 #if 0
 381         if (!ipxcksum)
 382                 ipx->ipx_sum = 0xffff;
 383 #endif
 384
 385         error = ipx_outputfl(m, &ipx_droute, flags);
 386         if (error == 0) {
 387                 ipxstat.ipxs_forward++;
 388
 389                 if (ipxprintfs) {
 390                         printf("forward: ");
 391                         ipx_printhost(&ipx->ipx_sna);
 392                         printf(" to ");
 393                         ipx_printhost(&ipx->ipx_dna);
 394                         printf(" hops %d\n", ipx->ipx_tc);
 395                 }
 396         } else if (mcopy != NULL) {
 397                 ipx = mtod(mcopy, struct ipx *);
 398                 switch (error) {
 399
 400                 case ENETUNREACH:
 401                 case EHOSTDOWN:
 402                 case EHOSTUNREACH:
 403                 case ENETDOWN:
 404                 case EPERM:
 405                         ipxstat.ipxs_noroute++;
 406                         break;
 407
 408                 case EMSGSIZE:
 409                         ipxstat.ipxs_mtutoosmall++;
 410                         break;
 411
 412                 case ENOBUFS:
 413                         ipxstat.ipxs_odropped++;
 414                         break;
 415                 }
 416                 mcopy = NULL;
 417                 m_freem(m);
 418         }
 419 cleanup:
 420         if (ok_there)
 421                 ipx_undo_route(&ipx_droute);
 422         if (ok_back)
 423                 ipx_undo_route(&ipx_sroute);
 424         if (mcopy != NULL)
 425                 m_freem(mcopy);
 426 }
 427
 428 static int
 429 ipx_do_route(src, ro)
 430 struct ipx_addr *src;
 431 struct route *ro;
 432 {
 433         struct sockaddr_ipx *dst;
 434
 435         bzero((caddr_t)ro, sizeof(*ro));
 436         dst = (struct sockaddr_ipx *)&ro->ro_dst;
 437
 438         dst->sipx_len = sizeof(*dst);
 439         dst->sipx_family = AF_IPX;
 440         dst->sipx_addr = *src;
 441         dst->sipx_addr.x_port = 0;
 442         rtalloc(ro);
 443         if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp == NULL) {
 444                 return (0);
 445         }
 446         ro->ro_rt->rt_use++;
 447         return (1);
 448 }
 449
 450 static void
 451 ipx_undo_route(ro)
 452 register struct route *ro;
 453 {
 454         if (ro->ro_rt != NULL) {
 455                 RTFREE(ro->ro_rt);
 456         }
 457 }
 458
 459 void
 460 ipx_watch_output(m, ifp)
 461 struct mbuf *m;
 462 struct ifnet *ifp;
 463 {
 464         register struct ipxpcb *ipxp;
 465         register struct ifaddr *ifa;
 466         register struct ipx_ifaddr *ia;
 467         /*
 468          * Give any raw listeners a crack at the packet
 469          */
 470         for (ipxp = ipxrawpcb.ipxp_next; ipxp != &ipxrawpcb;
 471              ipxp = ipxp->ipxp_next) {
 472                 struct mbuf *m0 = m_copy(m, 0, (int)M_COPYALL);
 473                 if (m0 != NULL) {
 474                         register struct ipx *ipx;
 475
 476                         M_PREPEND(m0, sizeof(*ipx), M_DONTWAIT);
 477                         if (m0 == NULL)
 478                                 continue;
 479                         ipx = mtod(m0, struct ipx *);
 480                         ipx->ipx_sna.x_net = ipx_zeronet;
 481                         for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
 482                                 if (ifp == ia->ia_ifp)
 483                                         break;
 484                         if (ia == NULL)
 485                                 ipx->ipx_sna.x_host = ipx_zerohost;
 486                         else
 487                                 ipx->ipx_sna.x_host =
 488                                     ia->ia_addr.sipx_addr.x_host;
 489
 490                         if (ifp != NULL && (ifp->if_flags & IFF_POINTOPOINT))
 491                             TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
 492                                 if (ifa->ifa_addr->sa_family == AF_IPX) {
 493                                     ipx->ipx_sna = IA_SIPX(ifa)->sipx_addr;
 494                                     break;
 495                                 }
 496                             }
 497                         ipx->ipx_len = ntohl(m0->m_pkthdr.len);
 498                         ipx_input(m0, ipxp);
 499                 }
 500         }
 501 }