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);
 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         /*
 137          * If no IPX addresses have been set yet but the interfaces
 138          * are receiving, can't do anything with incoming packets yet.
 139          */
 140         if (ipx_ifaddr == NULL)
 141                 goto bad;
 142
 143         ipxstat.ipxs_total++;
 144
 145         if ((m->m_flags & M_EXT || m->m_len < sizeof(struct ipx)) &&
 146             (m = m_pullup(m, sizeof(struct ipx))) == 0) {
 147                 ipxstat.ipxs_toosmall++;
 148                 return;
 149         }
 150
 151         /*
 152          * Give any raw listeners a crack at the packet
 153          */
 154         for (ipxp = ipxrawpcb.ipxp_next; ipxp != &ipxrawpcb;
 155              ipxp = ipxp->ipxp_next) {
 156                 struct mbuf *m1 = m_copy(m, 0, (int)M_COPYALL);
 157                 if (m1 != NULL)
 158                         ipx_input(m1, ipxp);
 159         }
 160
 161         ipx = mtod(m, struct ipx *);
 162         len = ntohs(ipx->ipx_len);
 163         /*
 164          * Check that the amount of data in the buffers
 165          * is as at least much as the IPX header would have us expect.
 166          * Trim mbufs if longer than we expect.
 167          * Drop packet if shorter than we expect.
 168          */
 169         if (m->m_pkthdr.len < len) {
 170                 ipxstat.ipxs_tooshort++;
 171                 goto bad;
 172         }
 173         if (m->m_pkthdr.len > len) {
 174                 if (m->m_len == m->m_pkthdr.len) {
 175                         m->m_len = len;
 176                         m->m_pkthdr.len = len;
 177                 } else
 178                         m_adj(m, len - m->m_pkthdr.len);
 179         }
 180         if (ipxcksum && ipx->ipx_sum != 0xffff) {
 181                 if (ipx->ipx_sum != ipx_cksum(m, len)) {
 182                         ipxstat.ipxs_badsum++;
 183                         goto bad;
 184                 }
 185         }
 186
 187         /*
 188          * Propagated (Netbios) packets (type 20) has to be handled
 189          * different. :-(
 190          */
 191         if (ipx->ipx_pt == IPXPROTO_NETBIOS) {
 192                 if (ipxnetbios) {
 193                         ipx_output_type20(m);
 194                         return;
 195                 } else
 196                         goto bad;
 197         }
 198
 199         /*
 200          * Is this a directed broadcast?
 201          */
 202         if (ipx_hosteqnh(ipx_broadhost,ipx->ipx_dna.x_host)) {
 203                 if ((!ipx_neteq(ipx->ipx_dna, ipx->ipx_sna)) &&
 204                     (!ipx_neteqnn(ipx->ipx_dna.x_net, ipx_broadnet)) &&
 205                     (!ipx_neteqnn(ipx->ipx_sna.x_net, ipx_zeronet)) &&
 206                     (!ipx_neteqnn(ipx->ipx_dna.x_net, ipx_zeronet)) ) {
 207                         /*
 208                          * If it is a broadcast to the net where it was
 209                          * received from, treat it as ours.
 210                          */
 211                         for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
 212                                 if((ia->ia_ifa.ifa_ifp == m->m_pkthdr.rcvif) &&
 213                                    ipx_neteq(ia->ia_addr.sipx_addr,
 214                                              ipx->ipx_dna))
 215                                         goto ours;
 216
 217                         /*
 218                          * Look to see if I need to eat this packet.
 219                          * Algorithm is to forward all young packets
 220                          * and prematurely age any packets which will
 221                          * by physically broadcasted.
 222                          * Any very old packets eaten without forwarding
 223                          * would die anyway.
 224                          *
 225                          * Suggestion of Bill Nesheim, Cornell U.
 226                          */
 227                         if (ipx->ipx_tc < IPX_MAXHOPS) {
 228                                 ipx_forward(m);
 229                                 return;
 230                         }
 231                 }
 232         /*
 233          * Is this our packet? If not, forward.
 234          */
 235         } else {
 236                 for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
 237                         if (ipx_hosteq(ipx->ipx_dna, ia->ia_addr.sipx_addr) &&
 238                             (ipx_neteq(ipx->ipx_dna, ia->ia_addr.sipx_addr) ||
 239                              ipx_neteqnn(ipx->ipx_dna.x_net, ipx_zeronet)))
 240                                 break;
 241
 242                 if (ia == NULL) {
 243                         ipx_forward(m);
 244                         return;
 245                 }
 246         }
 247 ours:
 248         /*
 249          * Locate pcb for datagram.
 250          */
 251         ipxp = ipx_pcblookup(&ipx->ipx_sna, ipx->ipx_dna.x_port, IPX_WILDCARD);
 252         /*
 253          * Switch out to protocol's input routine.
 254          */
 255         if (ipxp != NULL) {
 256                 ipxstat.ipxs_delivered++;
 257                 if ((ipxp->ipxp_flags & IPXP_ALL_PACKETS) == 0)
 258                         switch (ipx->ipx_pt) {
 259                         case IPXPROTO_SPX:
 260                                 spx_input(m, ipxp);
 261                                 return;
 262                         }
 263                 ipx_input(m, ipxp);
 264         } else
 265                 goto bad;
 266
 267         return;
 268
 269 bad:
 270         m_freem(m);
 271 }
 272
 273 void
 274 ipx_ctlinput(cmd, arg_as_sa, dummy)
 275         int cmd;
 276         struct sockaddr *arg_as_sa;     /* XXX should be swapped with dummy */
 277         void *dummy;
 278 {
 279         caddr_t arg = (/* XXX */ caddr_t)arg_as_sa;
 280         struct ipx_addr *ipx;
 281
 282         if (cmd < 0 || cmd >= PRC_NCMDS)
 283                 return;
 284         switch (cmd) {
 285                 struct sockaddr_ipx *sipx;
 286
 287         case PRC_IFDOWN:
 288         case PRC_HOSTDEAD:
 289         case PRC_HOSTUNREACH:
 290                 sipx = (struct sockaddr_ipx *)arg;
 291                 if (sipx->sipx_family != AF_IPX)
 292                         return;
 293                 ipx = &sipx->sipx_addr;
 294                 break;
 295
 296         default:
 297                 if (ipxprintfs)
 298                         printf("ipx_ctlinput: cmd %d.\n", cmd);
 299                 break;
 300         }
 301 }
 302
 303 /*
 304  * Forward a packet. If some error occurs drop the packet. IPX don't
 305  * have a way to return errors to the sender.
 306  */
 307
 308 static struct route ipx_droute;
 309 static struct route ipx_sroute;
 310
 311 static void
 312 ipx_forward(m)
 313 struct mbuf *m;
 314 {
 315         register struct ipx *ipx = mtod(m, struct ipx *);
 316         register int error;
 317         struct mbuf *mcopy = NULL;
 318         int agedelta = 1;
 319         int flags = IPX_FORWARDING;
 320         int ok_there = 0;
 321         int ok_back = 0;
 322
 323         if (ipxforwarding == 0) {
 324                 /* can't tell difference between net and host */
 325                 ipxstat.ipxs_cantforward++;
 326                 m_freem(m);
 327                 goto cleanup;
 328         }
 329         ipx->ipx_tc++;
 330         if (ipx->ipx_tc > IPX_MAXHOPS) {
 331                 ipxstat.ipxs_cantforward++;
 332                 m_freem(m);
 333                 goto cleanup;
 334         }
 335
 336         if ((ok_there = ipx_do_route(&ipx->ipx_dna,&ipx_droute)) == 0) {
 337                 ipxstat.ipxs_noroute++;
 338                 m_freem(m);
 339                 goto cleanup;
 340         }
 341         /*
 342          * Here we think about  forwarding  broadcast packets,
 343          * so we try to insure that it doesn't go back out
 344          * on the interface it came in on.  Also, if we
 345          * are going to physically broadcast this, let us
 346          * age the packet so we can eat it safely the second time around.
 347          */
 348         if (ipx->ipx_dna.x_host.c_host[0] & 0x1) {
 349                 struct ipx_ifaddr *ia = ipx_iaonnetof(&ipx->ipx_dna);
 350                 struct ifnet *ifp;
 351                 if (ia != NULL) {
 352                         /* I'm gonna hafta eat this packet */
 353                         agedelta += IPX_MAXHOPS - ipx->ipx_tc;
 354                         ipx->ipx_tc = IPX_MAXHOPS;
 355                 }
 356                 if ((ok_back = ipx_do_route(&ipx->ipx_sna,&ipx_sroute)) == 0) {
 357                         /* error = ENETUNREACH; He'll never get it! */
 358                         ipxstat.ipxs_noroute++;
 359                         m_freem(m);
 360                         goto cleanup;
 361                 }
 362                 if (ipx_droute.ro_rt &&
 363                     (ifp = ipx_droute.ro_rt->rt_ifp) &&
 364                     ipx_sroute.ro_rt &&
 365                     (ifp != ipx_sroute.ro_rt->rt_ifp)) {
 366                         flags |= IPX_ALLOWBROADCAST;
 367                 } else {
 368                         ipxstat.ipxs_noroute++;
 369                         m_freem(m);
 370                         goto cleanup;
 371                 }
 372         }
 373         /*
 374          * We don't need to recompute checksum because ipx_tc field
 375          * is ignored by checksum calculation routine, however
 376          * it may be desirable to reset checksum if ipxcksum == 0
 377          */
 378 #if 0
 379         if (!ipxcksum)
 380                 ipx->ipx_sum = 0xffff;
 381 #endif
 382
 383         error = ipx_outputfl(m, &ipx_droute, flags);
 384         if (error == 0) {
 385                 ipxstat.ipxs_forward++;
 386
 387                 if (ipxprintfs) {
 388                         printf("forward: ");
 389                         ipx_printhost(&ipx->ipx_sna);
 390                         printf(" to ");
 391                         ipx_printhost(&ipx->ipx_dna);
 392                         printf(" hops %d\n", ipx->ipx_tc);
 393                 }
 394         } else if (mcopy != NULL) {
 395                 ipx = mtod(mcopy, struct ipx *);
 396                 switch (error) {
 397
 398                 case ENETUNREACH:
 399                 case EHOSTDOWN:
 400                 case EHOSTUNREACH:
 401                 case ENETDOWN:
 402                 case EPERM:
 403                         ipxstat.ipxs_noroute++;
 404                         break;
 405
 406                 case EMSGSIZE:
 407                         ipxstat.ipxs_mtutoosmall++;
 408                         break;
 409
 410                 case ENOBUFS:
 411                         ipxstat.ipxs_odropped++;
 412                         break;
 413                 }
 414                 mcopy = NULL;
 415                 m_freem(m);
 416         }
 417 cleanup:
 418         if (ok_there)
 419                 ipx_undo_route(&ipx_droute);
 420         if (ok_back)
 421                 ipx_undo_route(&ipx_sroute);
 422         if (mcopy != NULL)
 423                 m_freem(mcopy);
 424 }
 425
 426 static int
 427 ipx_do_route(src, ro)
 428 struct ipx_addr *src;
 429 struct route *ro;
 430 {
 431         struct sockaddr_ipx *dst;
 432
 433         bzero((caddr_t)ro, sizeof(*ro));
 434         dst = (struct sockaddr_ipx *)&ro->ro_dst;
 435
 436         dst->sipx_len = sizeof(*dst);
 437         dst->sipx_family = AF_IPX;
 438         dst->sipx_addr = *src;
 439         dst->sipx_addr.x_port = 0;
 440         rtalloc(ro);
 441         if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp == NULL) {
 442                 return (0);
 443         }
 444         ro->ro_rt->rt_use++;
 445         return (1);
 446 }
 447
 448 static void
 449 ipx_undo_route(ro)
 450 register struct route *ro;
 451 {
 452         if (ro->ro_rt != NULL) {
 453                 RTFREE(ro->ro_rt);
 454         }
 455 }
 456
 457 void
 458 ipx_watch_output(m, ifp)
 459 struct mbuf *m;
 460 struct ifnet *ifp;
 461 {
 462         register struct ipxpcb *ipxp;
 463         register struct ifaddr *ifa;
 464         register struct ipx_ifaddr *ia;
 465         /*
 466          * Give any raw listeners a crack at the packet
 467          */
 468         for (ipxp = ipxrawpcb.ipxp_next; ipxp != &ipxrawpcb;
 469              ipxp = ipxp->ipxp_next) {
 470                 struct mbuf *m0 = m_copy(m, 0, (int)M_COPYALL);
 471                 if (m0 != NULL) {
 472                         register struct ipx *ipx;
 473
 474                         M_PREPEND(m0, sizeof(*ipx), M_DONTWAIT);
 475                         if (m0 == NULL)
 476                                 continue;
 477                         ipx = mtod(m0, struct ipx *);
 478                         ipx->ipx_sna.x_net = ipx_zeronet;
 479                         for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
 480                                 if (ifp == ia->ia_ifp)
 481                                         break;
 482                         if (ia == NULL)
 483                                 ipx->ipx_sna.x_host = ipx_zerohost;
 484                         else
 485                                 ipx->ipx_sna.x_host =
 486                                     ia->ia_addr.sipx_addr.x_host;
 487
 488                         if (ifp != NULL && (ifp->if_flags & IFF_POINTOPOINT))
 489                             TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
 490                                 if (ifa->ifa_addr->sa_family == AF_IPX) {
 491                                     ipx->ipx_sna = IA_SIPX(ifa)->sipx_addr;
 492                                     break;
 493                                 }
 494                             }
 495                         ipx->ipx_len = ntohl(m0->m_pkthdr.len);
 496                         ipx_input(m0, ipxp);
 497                 }
 498         }
 499 }