sys/netproto/ipx/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  * $FreeBSD: src/sys/netipx/ipx_input.c,v 1.22.2.2 2001/02/22 09:44:18 bp Exp $
  37  * $DragonFly: src/sys/netproto/ipx/ipx_input.c,v 1.12 2004/06/02 14:43:02 eirikn Exp $
  38  */
  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 <sys/thread2.h>
  50 #include <sys/msgport2.h>
  51
  52 #include <net/if.h>
  53 #include <net/route.h>
  54 #include <net/netisr.h>
  55 #include <net/intrq.h>
  56
  57 #include "ipx.h"
  58 #include "spx.h"
  59 #include "ipx_if.h"
  60 #include "ipx_pcb.h"
  61 #include "ipx_var.h"
  62
  63 int     ipxcksum = 0;
  64 SYSCTL_INT(_net_ipx_ipx, OID_AUTO, checksum, CTLFLAG_RW,
  65            &ipxcksum, 0, "");
  66
  67 static int      ipxprintfs = 0;         /* printing forwarding information */
  68 SYSCTL_INT(_net_ipx_ipx, OID_AUTO, ipxprintfs, CTLFLAG_RW,
  69            &ipxprintfs, 0, "");
  70
  71 static int      ipxforwarding = 0;
  72 SYSCTL_INT(_net_ipx_ipx, OID_AUTO, ipxforwarding, CTLFLAG_RW,
  73             &ipxforwarding, 0, "");
  74
  75 static int      ipxnetbios = 0;
  76 SYSCTL_INT(_net_ipx, OID_AUTO, ipxnetbios, CTLFLAG_RW,
  77            &ipxnetbios, 0, "");
  78
  79 union   ipx_net ipx_zeronet;
  80 union   ipx_host ipx_zerohost;
  81
  82 union   ipx_net ipx_broadnet;
  83 union   ipx_host ipx_broadhost;
  84
  85 struct  ipxstat ipxstat;
  86 struct  sockaddr_ipx ipx_netmask, ipx_hostmask;
  87
  88 static  u_short allones[] = {-1, -1, -1};
  89
  90 struct  ipxpcb ipxpcb;
  91 struct  ipxpcb ipxrawpcb;
  92
  93 long    ipx_pexseq;
  94
  95 static  int ipxintr(struct netmsg *);
  96 static  int ipx_do_route(struct ipx_addr *src, struct route *ro);
  97 static  void ipx_undo_route(struct route *ro);
  98 static  void ipx_forward(struct mbuf *m);
  99
 100 /*
 101  * IPX initialization.
 102  */
 103
 104 void
 105 ipx_init()
 106 {
 107         ipx_broadnet = *(union ipx_net *)allones;
 108         ipx_broadhost = *(union ipx_host *)allones;
 109
 110         read_random(&ipx_pexseq, sizeof ipx_pexseq);
 111         ipxpcb.ipxp_next = ipxpcb.ipxp_prev = &ipxpcb;
 112         ipxrawpcb.ipxp_next = ipxrawpcb.ipxp_prev = &ipxrawpcb;
 113
 114         ipx_netmask.sipx_len = 6;
 115         ipx_netmask.sipx_addr.x_net = ipx_broadnet;
 116
 117         ipx_hostmask.sipx_len = 12;
 118         ipx_hostmask.sipx_addr.x_net = ipx_broadnet;
 119         ipx_hostmask.sipx_addr.x_host = ipx_broadhost;
 120
 121         netisr_register(NETISR_IPX, cpu0_portfn, ipxintr);
 122 }
 123
 124 /*
 125  * IPX input routine.  Pass to next level.
 126  */
 127 static int
 128 ipxintr(struct netmsg *msg)
 129 {
 130         struct mbuf *m = ((struct netmsg_packet *)msg)->nm_packet;
 131         struct ipx *ipx;
 132         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                 goto out;
 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                         goto out;
 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                                 goto out;
 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                         goto out;
 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                                 goto out;
 262                         }
 263                 ipx_input(m, ipxp);
 264         } else
 265                 goto bad;
 266
 267         goto out;
 268
 269 bad:
 270         m_freem(m);
 271 out:
 272         lwkt_replymsg(&msg->nm_lmsg, 0);
 273         return(EASYNC);
 274 }
 275
 276 void
 277 ipx_ctlinput(cmd, arg_as_sa, dummy)
 278         int cmd;
 279         struct sockaddr *arg_as_sa;     /* XXX should be swapped with dummy */
 280         void *dummy;
 281 {
 282         caddr_t arg = (/* XXX */ caddr_t)arg_as_sa;
 283         struct ipx_addr *ipx;
 284
 285         if (cmd < 0 || cmd > PRC_NCMDS)
 286                 return;
 287         switch (cmd) {
 288                 struct sockaddr_ipx *sipx;
 289
 290         case PRC_IFDOWN:
 291         case PRC_HOSTDEAD:
 292         case PRC_HOSTUNREACH:
 293                 sipx = (struct sockaddr_ipx *)arg;
 294                 if (sipx->sipx_family != AF_IPX)
 295                         return;
 296                 ipx = &sipx->sipx_addr;
 297                 break;
 298
 299         default:
 300                 if (ipxprintfs)
 301                         printf("ipx_ctlinput: cmd %d.\n", cmd);
 302                 break;
 303         }
 304 }
 305
 306 /*
 307  * Forward a packet. If some error occurs drop the packet. IPX don't
 308  * have a way to return errors to the sender.
 309  */
 310
 311 static struct route ipx_droute;
 312 static struct route ipx_sroute;
 313
 314 static void
 315 ipx_forward(m)
 316 struct mbuf *m;
 317 {
 318         struct ipx *ipx = mtod(m, struct ipx *);
 319         int error;
 320         struct mbuf *mcopy = NULL;
 321         int agedelta = 1;
 322         int flags = IPX_FORWARDING;
 323         int ok_there = 0;
 324         int ok_back = 0;
 325
 326         if (ipxforwarding == 0) {
 327                 /* can't tell difference between net and host */
 328                 ipxstat.ipxs_cantforward++;
 329                 m_freem(m);
 330                 goto cleanup;
 331         }
 332         ipx->ipx_tc++;
 333         if (ipx->ipx_tc > IPX_MAXHOPS) {
 334                 ipxstat.ipxs_cantforward++;
 335                 m_freem(m);
 336                 goto cleanup;
 337         }
 338
 339         if ((ok_there = ipx_do_route(&ipx->ipx_dna,&ipx_droute)) == 0) {
 340                 ipxstat.ipxs_noroute++;
 341                 m_freem(m);
 342                 goto cleanup;
 343         }
 344         /*
 345          * Here we think about  forwarding  broadcast packets,
 346          * so we try to insure that it doesn't go back out
 347          * on the interface it came in on.  Also, if we
 348          * are going to physically broadcast this, let us
 349          * age the packet so we can eat it safely the second time around.
 350          */
 351         if (ipx->ipx_dna.x_host.c_host[0] & 0x1) {
 352                 struct ipx_ifaddr *ia = ipx_iaonnetof(&ipx->ipx_dna);
 353                 struct ifnet *ifp;
 354                 if (ia != NULL) {
 355                         /* I'm gonna hafta eat this packet */
 356                         agedelta += IPX_MAXHOPS - ipx->ipx_tc;
 357                         ipx->ipx_tc = IPX_MAXHOPS;
 358                 }
 359                 if ((ok_back = ipx_do_route(&ipx->ipx_sna,&ipx_sroute)) == 0) {
 360                         /* error = ENETUNREACH; He'll never get it! */
 361                         ipxstat.ipxs_noroute++;
 362                         m_freem(m);
 363                         goto cleanup;
 364                 }
 365                 if (ipx_droute.ro_rt &&
 366                     (ifp = ipx_droute.ro_rt->rt_ifp) &&
 367                     ipx_sroute.ro_rt &&
 368                     (ifp != ipx_sroute.ro_rt->rt_ifp)) {
 369                         flags |= IPX_ALLOWBROADCAST;
 370                 } else {
 371                         ipxstat.ipxs_noroute++;
 372                         m_freem(m);
 373                         goto cleanup;
 374                 }
 375         }
 376         /*
 377          * We don't need to recompute checksum because ipx_tc field
 378          * is ignored by checksum calculation routine, however
 379          * it may be desirable to reset checksum if ipxcksum == 0
 380          */
 381 #if 0
 382         if (!ipxcksum)
 383                 ipx->ipx_sum = 0xffff;
 384 #endif
 385
 386         error = ipx_outputfl(m, &ipx_droute, flags);
 387         if (error == 0) {
 388                 ipxstat.ipxs_forward++;
 389
 390                 if (ipxprintfs) {
 391                         printf("forward: ");
 392                         ipx_printhost(&ipx->ipx_sna);
 393                         printf(" to ");
 394                         ipx_printhost(&ipx->ipx_dna);
 395                         printf(" hops %d\n", ipx->ipx_tc);
 396                 }
 397         } else if (mcopy != NULL) {
 398                 ipx = mtod(mcopy, struct ipx *);
 399                 switch (error) {
 400
 401                 case ENETUNREACH:
 402                 case EHOSTDOWN:
 403                 case EHOSTUNREACH:
 404                 case ENETDOWN:
 405                 case EPERM:
 406                         ipxstat.ipxs_noroute++;
 407                         break;
 408
 409                 case EMSGSIZE:
 410                         ipxstat.ipxs_mtutoosmall++;
 411                         break;
 412
 413                 case ENOBUFS:
 414                         ipxstat.ipxs_odropped++;
 415                         break;
 416                 }
 417                 mcopy = NULL;
 418                 m_freem(m);
 419         }
 420 cleanup:
 421         if (ok_there)
 422                 ipx_undo_route(&ipx_droute);
 423         if (ok_back)
 424                 ipx_undo_route(&ipx_sroute);
 425         if (mcopy != NULL)
 426                 m_freem(mcopy);
 427 }
 428
 429 static int
 430 ipx_do_route(src, ro)
 431 struct ipx_addr *src;
 432 struct route *ro;
 433 {
 434         struct sockaddr_ipx *dst;
 435
 436         bzero((caddr_t)ro, sizeof(*ro));
 437         dst = (struct sockaddr_ipx *)&ro->ro_dst;
 438
 439         dst->sipx_len = sizeof(*dst);
 440         dst->sipx_family = AF_IPX;
 441         dst->sipx_addr = *src;
 442         dst->sipx_addr.x_port = 0;
 443         rtalloc(ro);
 444         if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp == NULL) {
 445                 return (0);
 446         }
 447         ro->ro_rt->rt_use++;
 448         return (1);
 449 }
 450
 451 static void
 452 ipx_undo_route(ro)
 453 struct route *ro;
 454 {
 455         if (ro->ro_rt != NULL) {
 456                 RTFREE(ro->ro_rt);
 457         }
 458 }
 459
 460 void
 461 ipx_watch_output(m, ifp)
 462 struct mbuf *m;
 463 struct ifnet *ifp;
 464 {
 465         struct ipxpcb *ipxp;
 466         struct ifaddr *ifa;
 467         struct ipx_ifaddr *ia;
 468         /*
 469          * Give any raw listeners a crack at the packet
 470          */
 471         for (ipxp = ipxrawpcb.ipxp_next; ipxp != &ipxrawpcb;
 472              ipxp = ipxp->ipxp_next) {
 473                 struct mbuf *m0 = m_copy(m, 0, (int)M_COPYALL);
 474                 if (m0 != NULL) {
 475                         struct ipx *ipx;
 476
 477                         M_PREPEND(m0, sizeof(*ipx), MB_DONTWAIT);
 478                         if (m0 == NULL)
 479                                 continue;
 480                         ipx = mtod(m0, struct ipx *);
 481                         ipx->ipx_sna.x_net = ipx_zeronet;
 482                         for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
 483                                 if (ifp == ia->ia_ifp)
 484                                         break;
 485                         if (ia == NULL)
 486                                 ipx->ipx_sna.x_host = ipx_zerohost;
 487                         else
 488                                 ipx->ipx_sna.x_host =
 489                                     ia->ia_addr.sipx_addr.x_host;
 490
 491                         if (ifp != NULL && (ifp->if_flags & IFF_POINTOPOINT))
 492                             TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
 493                                 if (ifa->ifa_addr->sa_family == AF_IPX) {
 494                                     ipx->ipx_sna = IA_SIPX(ifa)->sipx_addr;
 495                                     break;
 496                                 }
 497                             }
 498                         ipx->ipx_len = ntohl(m0->m_pkthdr.len);
 499                         ipx_input(m0, ipxp);
 500                 }
 501         }
 502 }