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 1.7 2004/02/24 19:17:08 joerg 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 <net/if.h>
  50 #include <net/route.h>
  51 #include <net/netisr.h>
  52 #include <net/intrq.h>
  53
  54 #include "ipx.h"
  55 #include "spx.h"
  56 #include "ipx_if.h"
  57 #include "ipx_pcb.h"
  58 #include "ipx_var.h"
  59
  60 int     ipxcksum = 0;
  61 SYSCTL_INT(_net_ipx_ipx, OID_AUTO, checksum, CTLFLAG_RW,
  62            &ipxcksum, 0, "");
  63
  64 static int      ipxprintfs = 0;         /* printing forwarding information */
  65 SYSCTL_INT(_net_ipx_ipx, OID_AUTO, ipxprintfs, CTLFLAG_RW,
  66            &ipxprintfs, 0, "");
  67
  68 static int      ipxforwarding = 0;
  69 SYSCTL_INT(_net_ipx_ipx, OID_AUTO, ipxforwarding, CTLFLAG_RW,
  70             &ipxforwarding, 0, "");
  71
  72 static int      ipxnetbios = 0;
  73 SYSCTL_INT(_net_ipx, OID_AUTO, ipxnetbios, CTLFLAG_RW,
  74            &ipxnetbios, 0, "");
  75
  76 union   ipx_net ipx_zeronet;
  77 union   ipx_host ipx_zerohost;
  78
  79 union   ipx_net ipx_broadnet;
  80 union   ipx_host ipx_broadhost;
  81
  82 struct  ipxstat ipxstat;
  83 struct  sockaddr_ipx ipx_netmask, ipx_hostmask;
  84
  85 static  u_short allones[] = {-1, -1, -1};
  86
  87 struct  ipxpcb ipxpcb;
  88 struct  ipxpcb ipxrawpcb;
  89
  90 long    ipx_pexseq;
  91
  92 static  void ipxintr(struct mbuf *);
  93 static  int ipx_do_route(struct ipx_addr *src, struct route *ro);
  94 static  void ipx_undo_route(struct route *ro);
  95 static  void ipx_forward(struct mbuf *m);
  96
  97 /*
  98  * IPX initialization.
  99  */
 100
 101 void
 102 ipx_init()
 103 {
 104         ipx_broadnet = *(union ipx_net *)allones;
 105         ipx_broadhost = *(union ipx_host *)allones;
 106
 107         read_random(&ipx_pexseq, sizeof ipx_pexseq);
 108         ipxpcb.ipxp_next = ipxpcb.ipxp_prev = &ipxpcb;
 109         ipxrawpcb.ipxp_next = ipxrawpcb.ipxp_prev = &ipxrawpcb;
 110
 111         ipx_netmask.sipx_len = 6;
 112         ipx_netmask.sipx_addr.x_net = ipx_broadnet;
 113
 114         ipx_hostmask.sipx_len = 12;
 115         ipx_hostmask.sipx_addr.x_net = ipx_broadnet;
 116         ipx_hostmask.sipx_addr.x_host = ipx_broadhost;
 117
 118         netisr_register(NETISR_IPX, cpu0_portfn, ipxintr);
 119 }
 120
 121 /*
 122  * IPX input routine.  Pass to next level.
 123  */
 124 static void
 125 ipxintr(struct mbuf *m)
 126 {
 127         struct ipx *ipx;
 128         struct ipxpcb *ipxp;
 129         struct ipx_ifaddr *ia;
 130         int len;
 131
 132         /*
 133          * If no IPX addresses have been set yet but the interfaces
 134          * are receiving, can't do anything with incoming packets yet.
 135          */
 136         if (ipx_ifaddr == NULL)
 137                 goto bad;
 138
 139         ipxstat.ipxs_total++;
 140
 141         if ((m->m_flags & M_EXT || m->m_len < sizeof(struct ipx)) &&
 142             (m = m_pullup(m, sizeof(struct ipx))) == 0) {
 143                 ipxstat.ipxs_toosmall++;
 144                 return;
 145         }
 146
 147         /*
 148          * Give any raw listeners a crack at the packet
 149          */
 150         for (ipxp = ipxrawpcb.ipxp_next; ipxp != &ipxrawpcb;
 151              ipxp = ipxp->ipxp_next) {
 152                 struct mbuf *m1 = m_copy(m, 0, (int)M_COPYALL);
 153                 if (m1 != NULL)
 154                         ipx_input(m1, ipxp);
 155         }
 156
 157         ipx = mtod(m, struct ipx *);
 158         len = ntohs(ipx->ipx_len);
 159         /*
 160          * Check that the amount of data in the buffers
 161          * is as at least much as the IPX header would have us expect.
 162          * Trim mbufs if longer than we expect.
 163          * Drop packet if shorter than we expect.
 164          */
 165         if (m->m_pkthdr.len < len) {
 166                 ipxstat.ipxs_tooshort++;
 167                 goto bad;
 168         }
 169         if (m->m_pkthdr.len > len) {
 170                 if (m->m_len == m->m_pkthdr.len) {
 171                         m->m_len = len;
 172                         m->m_pkthdr.len = len;
 173                 } else
 174                         m_adj(m, len - m->m_pkthdr.len);
 175         }
 176         if (ipxcksum && ipx->ipx_sum != 0xffff) {
 177                 if (ipx->ipx_sum != ipx_cksum(m, len)) {
 178                         ipxstat.ipxs_badsum++;
 179                         goto bad;
 180                 }
 181         }
 182
 183         /*
 184          * Propagated (Netbios) packets (type 20) has to be handled
 185          * different. :-(
 186          */
 187         if (ipx->ipx_pt == IPXPROTO_NETBIOS) {
 188                 if (ipxnetbios) {
 189                         ipx_output_type20(m);
 190                         return;
 191                 } else
 192                         goto bad;
 193         }
 194
 195         /*
 196          * Is this a directed broadcast?
 197          */
 198         if (ipx_hosteqnh(ipx_broadhost,ipx->ipx_dna.x_host)) {
 199                 if ((!ipx_neteq(ipx->ipx_dna, ipx->ipx_sna)) &&
 200                     (!ipx_neteqnn(ipx->ipx_dna.x_net, ipx_broadnet)) &&
 201                     (!ipx_neteqnn(ipx->ipx_sna.x_net, ipx_zeronet)) &&
 202                     (!ipx_neteqnn(ipx->ipx_dna.x_net, ipx_zeronet)) ) {
 203                         /*
 204                          * If it is a broadcast to the net where it was
 205                          * received from, treat it as ours.
 206                          */
 207                         for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
 208                                 if((ia->ia_ifa.ifa_ifp == m->m_pkthdr.rcvif) &&
 209                                    ipx_neteq(ia->ia_addr.sipx_addr,
 210                                              ipx->ipx_dna))
 211                                         goto ours;
 212
 213                         /*
 214                          * Look to see if I need to eat this packet.
 215                          * Algorithm is to forward all young packets
 216                          * and prematurely age any packets which will
 217                          * by physically broadcasted.
 218                          * Any very old packets eaten without forwarding
 219                          * would die anyway.
 220                          *
 221                          * Suggestion of Bill Nesheim, Cornell U.
 222                          */
 223                         if (ipx->ipx_tc < IPX_MAXHOPS) {
 224                                 ipx_forward(m);
 225                                 return;
 226                         }
 227                 }
 228         /*
 229          * Is this our packet? If not, forward.
 230          */
 231         } else {
 232                 for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
 233                         if (ipx_hosteq(ipx->ipx_dna, ia->ia_addr.sipx_addr) &&
 234                             (ipx_neteq(ipx->ipx_dna, ia->ia_addr.sipx_addr) ||
 235                              ipx_neteqnn(ipx->ipx_dna.x_net, ipx_zeronet)))
 236                                 break;
 237
 238                 if (ia == NULL) {
 239                         ipx_forward(m);
 240                         return;
 241                 }
 242         }
 243 ours:
 244         /*
 245          * Locate pcb for datagram.
 246          */
 247         ipxp = ipx_pcblookup(&ipx->ipx_sna, ipx->ipx_dna.x_port, IPX_WILDCARD);
 248         /*
 249          * Switch out to protocol's input routine.
 250          */
 251         if (ipxp != NULL) {
 252                 ipxstat.ipxs_delivered++;
 253                 if ((ipxp->ipxp_flags & IPXP_ALL_PACKETS) == 0)
 254                         switch (ipx->ipx_pt) {
 255                         case IPXPROTO_SPX:
 256                                 spx_input(m, ipxp);
 257                                 return;
 258                         }
 259                 ipx_input(m, ipxp);
 260         } else
 261                 goto bad;
 262
 263         return;
 264
 265 bad:
 266         m_freem(m);
 267 }
 268
 269 void
 270 ipx_ctlinput(cmd, arg_as_sa, dummy)
 271         int cmd;
 272         struct sockaddr *arg_as_sa;     /* XXX should be swapped with dummy */
 273         void *dummy;
 274 {
 275         caddr_t arg = (/* XXX */ caddr_t)arg_as_sa;
 276         struct ipx_addr *ipx;
 277
 278         if (cmd < 0 || cmd > PRC_NCMDS)
 279                 return;
 280         switch (cmd) {
 281                 struct sockaddr_ipx *sipx;
 282
 283         case PRC_IFDOWN:
 284         case PRC_HOSTDEAD:
 285         case PRC_HOSTUNREACH:
 286                 sipx = (struct sockaddr_ipx *)arg;
 287                 if (sipx->sipx_family != AF_IPX)
 288                         return;
 289                 ipx = &sipx->sipx_addr;
 290                 break;
 291
 292         default:
 293                 if (ipxprintfs)
 294                         printf("ipx_ctlinput: cmd %d.\n", cmd);
 295                 break;
 296         }
 297 }
 298
 299 /*
 300  * Forward a packet. If some error occurs drop the packet. IPX don't
 301  * have a way to return errors to the sender.
 302  */
 303
 304 static struct route ipx_droute;
 305 static struct route ipx_sroute;
 306
 307 static void
 308 ipx_forward(m)
 309 struct mbuf *m;
 310 {
 311         struct ipx *ipx = mtod(m, struct ipx *);
 312         int error;
 313         struct mbuf *mcopy = NULL;
 314         int agedelta = 1;
 315         int flags = IPX_FORWARDING;
 316         int ok_there = 0;
 317         int ok_back = 0;
 318
 319         if (ipxforwarding == 0) {
 320                 /* can't tell difference between net and host */
 321                 ipxstat.ipxs_cantforward++;
 322                 m_freem(m);
 323                 goto cleanup;
 324         }
 325         ipx->ipx_tc++;
 326         if (ipx->ipx_tc > IPX_MAXHOPS) {
 327                 ipxstat.ipxs_cantforward++;
 328                 m_freem(m);
 329                 goto cleanup;
 330         }
 331
 332         if ((ok_there = ipx_do_route(&ipx->ipx_dna,&ipx_droute)) == 0) {
 333                 ipxstat.ipxs_noroute++;
 334                 m_freem(m);
 335                 goto cleanup;
 336         }
 337         /*
 338          * Here we think about  forwarding  broadcast packets,
 339          * so we try to insure that it doesn't go back out
 340          * on the interface it came in on.  Also, if we
 341          * are going to physically broadcast this, let us
 342          * age the packet so we can eat it safely the second time around.
 343          */
 344         if (ipx->ipx_dna.x_host.c_host[0] & 0x1) {
 345                 struct ipx_ifaddr *ia = ipx_iaonnetof(&ipx->ipx_dna);
 346                 struct ifnet *ifp;
 347                 if (ia != NULL) {
 348                         /* I'm gonna hafta eat this packet */
 349                         agedelta += IPX_MAXHOPS - ipx->ipx_tc;
 350                         ipx->ipx_tc = IPX_MAXHOPS;
 351                 }
 352                 if ((ok_back = ipx_do_route(&ipx->ipx_sna,&ipx_sroute)) == 0) {
 353                         /* error = ENETUNREACH; He'll never get it! */
 354                         ipxstat.ipxs_noroute++;
 355                         m_freem(m);
 356                         goto cleanup;
 357                 }
 358                 if (ipx_droute.ro_rt &&
 359                     (ifp = ipx_droute.ro_rt->rt_ifp) &&
 360                     ipx_sroute.ro_rt &&
 361                     (ifp != ipx_sroute.ro_rt->rt_ifp)) {
 362                         flags |= IPX_ALLOWBROADCAST;
 363                 } else {
 364                         ipxstat.ipxs_noroute++;
 365                         m_freem(m);
 366                         goto cleanup;
 367                 }
 368         }
 369         /*
 370          * We don't need to recompute checksum because ipx_tc field
 371          * is ignored by checksum calculation routine, however
 372          * it may be desirable to reset checksum if ipxcksum == 0
 373          */
 374 #if 0
 375         if (!ipxcksum)
 376                 ipx->ipx_sum = 0xffff;
 377 #endif
 378
 379         error = ipx_outputfl(m, &ipx_droute, flags);
 380         if (error == 0) {
 381                 ipxstat.ipxs_forward++;
 382
 383                 if (ipxprintfs) {
 384                         printf("forward: ");
 385                         ipx_printhost(&ipx->ipx_sna);
 386                         printf(" to ");
 387                         ipx_printhost(&ipx->ipx_dna);
 388                         printf(" hops %d\n", ipx->ipx_tc);
 389                 }
 390         } else if (mcopy != NULL) {
 391                 ipx = mtod(mcopy, struct ipx *);
 392                 switch (error) {
 393
 394                 case ENETUNREACH:
 395                 case EHOSTDOWN:
 396                 case EHOSTUNREACH:
 397                 case ENETDOWN:
 398                 case EPERM:
 399                         ipxstat.ipxs_noroute++;
 400                         break;
 401
 402                 case EMSGSIZE:
 403                         ipxstat.ipxs_mtutoosmall++;
 404                         break;
 405
 406                 case ENOBUFS:
 407                         ipxstat.ipxs_odropped++;
 408                         break;
 409                 }
 410                 mcopy = NULL;
 411                 m_freem(m);
 412         }
 413 cleanup:
 414         if (ok_there)
 415                 ipx_undo_route(&ipx_droute);
 416         if (ok_back)
 417                 ipx_undo_route(&ipx_sroute);
 418         if (mcopy != NULL)
 419                 m_freem(mcopy);
 420 }
 421
 422 static int
 423 ipx_do_route(src, ro)
 424 struct ipx_addr *src;
 425 struct route *ro;
 426 {
 427         struct sockaddr_ipx *dst;
 428
 429         bzero((caddr_t)ro, sizeof(*ro));
 430         dst = (struct sockaddr_ipx *)&ro->ro_dst;
 431
 432         dst->sipx_len = sizeof(*dst);
 433         dst->sipx_family = AF_IPX;
 434         dst->sipx_addr = *src;
 435         dst->sipx_addr.x_port = 0;
 436         rtalloc(ro);
 437         if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp == NULL) {
 438                 return (0);
 439         }
 440         ro->ro_rt->rt_use++;
 441         return (1);
 442 }
 443
 444 static void
 445 ipx_undo_route(ro)
 446 struct route *ro;
 447 {
 448         if (ro->ro_rt != NULL) {
 449                 RTFREE(ro->ro_rt);
 450         }
 451 }
 452
 453 void
 454 ipx_watch_output(m, ifp)
 455 struct mbuf *m;
 456 struct ifnet *ifp;
 457 {
 458         struct ipxpcb *ipxp;
 459         struct ifaddr *ifa;
 460         struct ipx_ifaddr *ia;
 461         /*
 462          * Give any raw listeners a crack at the packet
 463          */
 464         for (ipxp = ipxrawpcb.ipxp_next; ipxp != &ipxrawpcb;
 465              ipxp = ipxp->ipxp_next) {
 466                 struct mbuf *m0 = m_copy(m, 0, (int)M_COPYALL);
 467                 if (m0 != NULL) {
 468                         struct ipx *ipx;
 469
 470                         M_PREPEND(m0, sizeof(*ipx), M_DONTWAIT);
 471                         if (m0 == NULL)
 472                                 continue;
 473                         ipx = mtod(m0, struct ipx *);
 474                         ipx->ipx_sna.x_net = ipx_zeronet;
 475                         for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
 476                                 if (ifp == ia->ia_ifp)
 477                                         break;
 478                         if (ia == NULL)
 479                                 ipx->ipx_sna.x_host = ipx_zerohost;
 480                         else
 481                                 ipx->ipx_sna.x_host =
 482                                     ia->ia_addr.sipx_addr.x_host;
 483
 484                         if (ifp != NULL && (ifp->if_flags & IFF_POINTOPOINT))
 485                             TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
 486                                 if (ifa->ifa_addr->sa_family == AF_IPX) {
 487                                     ipx->ipx_sna = IA_SIPX(ifa)->sipx_addr;
 488                                     break;
 489                                 }
 490                             }
 491                         ipx->ipx_len = ntohl(m0->m_pkthdr.len);
 492                         ipx_input(m0, ipxp);
 493                 }
 494         }
 495 }