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 1.8 2004/03/06 01:58:56 hsu 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 netmsg *);
  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 netmsg *msg)
 126 {
 127         struct mbuf *m = ((struct netmsg_packet *)msg)->nm_packet;
 128         struct ipx *ipx;
 129         struct ipxpcb *ipxp;
 130         struct ipx_ifaddr *ia;
 131         int len;
 132
 133         /*
 134          * If no IPX addresses have been set yet but the interfaces
 135          * are receiving, can't do anything with incoming packets yet.
 136          */
 137         if (ipx_ifaddr == NULL)
 138                 goto bad;
 139
 140         ipxstat.ipxs_total++;
 141
 142         if ((m->m_flags & M_EXT || m->m_len < sizeof(struct ipx)) &&
 143             (m = m_pullup(m, sizeof(struct ipx))) == 0) {
 144                 ipxstat.ipxs_toosmall++;
 145                 return;
 146         }
 147
 148         /*
 149          * Give any raw listeners a crack at the packet
 150          */
 151         for (ipxp = ipxrawpcb.ipxp_next; ipxp != &ipxrawpcb;
 152              ipxp = ipxp->ipxp_next) {
 153                 struct mbuf *m1 = m_copy(m, 0, (int)M_COPYALL);
 154                 if (m1 != NULL)
 155                         ipx_input(m1, ipxp);
 156         }
 157
 158         ipx = mtod(m, struct ipx *);
 159         len = ntohs(ipx->ipx_len);
 160         /*
 161          * Check that the amount of data in the buffers
 162          * is as at least much as the IPX header would have us expect.
 163          * Trim mbufs if longer than we expect.
 164          * Drop packet if shorter than we expect.
 165          */
 166         if (m->m_pkthdr.len < len) {
 167                 ipxstat.ipxs_tooshort++;
 168                 goto bad;
 169         }
 170         if (m->m_pkthdr.len > len) {
 171                 if (m->m_len == m->m_pkthdr.len) {
 172                         m->m_len = len;
 173                         m->m_pkthdr.len = len;
 174                 } else
 175                         m_adj(m, len - m->m_pkthdr.len);
 176         }
 177         if (ipxcksum && ipx->ipx_sum != 0xffff) {
 178                 if (ipx->ipx_sum != ipx_cksum(m, len)) {
 179                         ipxstat.ipxs_badsum++;
 180                         goto bad;
 181                 }
 182         }
 183
 184         /*
 185          * Propagated (Netbios) packets (type 20) has to be handled
 186          * different. :-(
 187          */
 188         if (ipx->ipx_pt == IPXPROTO_NETBIOS) {
 189                 if (ipxnetbios) {
 190                         ipx_output_type20(m);
 191                         return;
 192                 } else
 193                         goto bad;
 194         }
 195
 196         /*
 197          * Is this a directed broadcast?
 198          */
 199         if (ipx_hosteqnh(ipx_broadhost,ipx->ipx_dna.x_host)) {
 200                 if ((!ipx_neteq(ipx->ipx_dna, ipx->ipx_sna)) &&
 201                     (!ipx_neteqnn(ipx->ipx_dna.x_net, ipx_broadnet)) &&
 202                     (!ipx_neteqnn(ipx->ipx_sna.x_net, ipx_zeronet)) &&
 203                     (!ipx_neteqnn(ipx->ipx_dna.x_net, ipx_zeronet)) ) {
 204                         /*
 205                          * If it is a broadcast to the net where it was
 206                          * received from, treat it as ours.
 207                          */
 208                         for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
 209                                 if((ia->ia_ifa.ifa_ifp == m->m_pkthdr.rcvif) &&
 210                                    ipx_neteq(ia->ia_addr.sipx_addr,
 211                                              ipx->ipx_dna))
 212                                         goto ours;
 213
 214                         /*
 215                          * Look to see if I need to eat this packet.
 216                          * Algorithm is to forward all young packets
 217                          * and prematurely age any packets which will
 218                          * by physically broadcasted.
 219                          * Any very old packets eaten without forwarding
 220                          * would die anyway.
 221                          *
 222                          * Suggestion of Bill Nesheim, Cornell U.
 223                          */
 224                         if (ipx->ipx_tc < IPX_MAXHOPS) {
 225                                 ipx_forward(m);
 226                                 return;
 227                         }
 228                 }
 229         /*
 230          * Is this our packet? If not, forward.
 231          */
 232         } else {
 233                 for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
 234                         if (ipx_hosteq(ipx->ipx_dna, ia->ia_addr.sipx_addr) &&
 235                             (ipx_neteq(ipx->ipx_dna, ia->ia_addr.sipx_addr) ||
 236                              ipx_neteqnn(ipx->ipx_dna.x_net, ipx_zeronet)))
 237                                 break;
 238
 239                 if (ia == NULL) {
 240                         ipx_forward(m);
 241                         return;
 242                 }
 243         }
 244 ours:
 245         /*
 246          * Locate pcb for datagram.
 247          */
 248         ipxp = ipx_pcblookup(&ipx->ipx_sna, ipx->ipx_dna.x_port, IPX_WILDCARD);
 249         /*
 250          * Switch out to protocol's input routine.
 251          */
 252         if (ipxp != NULL) {
 253                 ipxstat.ipxs_delivered++;
 254                 if ((ipxp->ipxp_flags & IPXP_ALL_PACKETS) == 0)
 255                         switch (ipx->ipx_pt) {
 256                         case IPXPROTO_SPX:
 257                                 spx_input(m, ipxp);
 258                                 return;
 259                         }
 260                 ipx_input(m, ipxp);
 261         } else
 262                 goto bad;
 263
 264         return;
 265
 266 bad:
 267         m_freem(m);
 268 }
 269
 270 void
 271 ipx_ctlinput(cmd, arg_as_sa, dummy)
 272         int cmd;
 273         struct sockaddr *arg_as_sa;     /* XXX should be swapped with dummy */
 274         void *dummy;
 275 {
 276         caddr_t arg = (/* XXX */ caddr_t)arg_as_sa;
 277         struct ipx_addr *ipx;
 278
 279         if (cmd < 0 || cmd > PRC_NCMDS)
 280                 return;
 281         switch (cmd) {
 282                 struct sockaddr_ipx *sipx;
 283
 284         case PRC_IFDOWN:
 285         case PRC_HOSTDEAD:
 286         case PRC_HOSTUNREACH:
 287                 sipx = (struct sockaddr_ipx *)arg;
 288                 if (sipx->sipx_family != AF_IPX)
 289                         return;
 290                 ipx = &sipx->sipx_addr;
 291                 break;
 292
 293         default:
 294                 if (ipxprintfs)
 295                         printf("ipx_ctlinput: cmd %d.\n", cmd);
 296                 break;
 297         }
 298 }
 299
 300 /*
 301  * Forward a packet. If some error occurs drop the packet. IPX don't
 302  * have a way to return errors to the sender.
 303  */
 304
 305 static struct route ipx_droute;
 306 static struct route ipx_sroute;
 307
 308 static void
 309 ipx_forward(m)
 310 struct mbuf *m;
 311 {
 312         struct ipx *ipx = mtod(m, struct ipx *);
 313         int error;
 314         struct mbuf *mcopy = NULL;
 315         int agedelta = 1;
 316         int flags = IPX_FORWARDING;
 317         int ok_there = 0;
 318         int ok_back = 0;
 319
 320         if (ipxforwarding == 0) {
 321                 /* can't tell difference between net and host */
 322                 ipxstat.ipxs_cantforward++;
 323                 m_freem(m);
 324                 goto cleanup;
 325         }
 326         ipx->ipx_tc++;
 327         if (ipx->ipx_tc > IPX_MAXHOPS) {
 328                 ipxstat.ipxs_cantforward++;
 329                 m_freem(m);
 330                 goto cleanup;
 331         }
 332
 333         if ((ok_there = ipx_do_route(&ipx->ipx_dna,&ipx_droute)) == 0) {
 334                 ipxstat.ipxs_noroute++;
 335                 m_freem(m);
 336                 goto cleanup;
 337         }
 338         /*
 339          * Here we think about  forwarding  broadcast packets,
 340          * so we try to insure that it doesn't go back out
 341          * on the interface it came in on.  Also, if we
 342          * are going to physically broadcast this, let us
 343          * age the packet so we can eat it safely the second time around.
 344          */
 345         if (ipx->ipx_dna.x_host.c_host[0] & 0x1) {
 346                 struct ipx_ifaddr *ia = ipx_iaonnetof(&ipx->ipx_dna);
 347                 struct ifnet *ifp;
 348                 if (ia != NULL) {
 349                         /* I'm gonna hafta eat this packet */
 350                         agedelta += IPX_MAXHOPS - ipx->ipx_tc;
 351                         ipx->ipx_tc = IPX_MAXHOPS;
 352                 }
 353                 if ((ok_back = ipx_do_route(&ipx->ipx_sna,&ipx_sroute)) == 0) {
 354                         /* error = ENETUNREACH; He'll never get it! */
 355                         ipxstat.ipxs_noroute++;
 356                         m_freem(m);
 357                         goto cleanup;
 358                 }
 359                 if (ipx_droute.ro_rt &&
 360                     (ifp = ipx_droute.ro_rt->rt_ifp) &&
 361                     ipx_sroute.ro_rt &&
 362                     (ifp != ipx_sroute.ro_rt->rt_ifp)) {
 363                         flags |= IPX_ALLOWBROADCAST;
 364                 } else {
 365                         ipxstat.ipxs_noroute++;
 366                         m_freem(m);
 367                         goto cleanup;
 368                 }
 369         }
 370         /*
 371          * We don't need to recompute checksum because ipx_tc field
 372          * is ignored by checksum calculation routine, however
 373          * it may be desirable to reset checksum if ipxcksum == 0
 374          */
 375 #if 0
 376         if (!ipxcksum)
 377                 ipx->ipx_sum = 0xffff;
 378 #endif
 379
 380         error = ipx_outputfl(m, &ipx_droute, flags);
 381         if (error == 0) {
 382                 ipxstat.ipxs_forward++;
 383
 384                 if (ipxprintfs) {
 385                         printf("forward: ");
 386                         ipx_printhost(&ipx->ipx_sna);
 387                         printf(" to ");
 388                         ipx_printhost(&ipx->ipx_dna);
 389                         printf(" hops %d\n", ipx->ipx_tc);
 390                 }
 391         } else if (mcopy != NULL) {
 392                 ipx = mtod(mcopy, struct ipx *);
 393                 switch (error) {
 394
 395                 case ENETUNREACH:
 396                 case EHOSTDOWN:
 397                 case EHOSTUNREACH:
 398                 case ENETDOWN:
 399                 case EPERM:
 400                         ipxstat.ipxs_noroute++;
 401                         break;
 402
 403                 case EMSGSIZE:
 404                         ipxstat.ipxs_mtutoosmall++;
 405                         break;
 406
 407                 case ENOBUFS:
 408                         ipxstat.ipxs_odropped++;
 409                         break;
 410                 }
 411                 mcopy = NULL;
 412                 m_freem(m);
 413         }
 414 cleanup:
 415         if (ok_there)
 416                 ipx_undo_route(&ipx_droute);
 417         if (ok_back)
 418                 ipx_undo_route(&ipx_sroute);
 419         if (mcopy != NULL)
 420                 m_freem(mcopy);
 421 }
 422
 423 static int
 424 ipx_do_route(src, ro)
 425 struct ipx_addr *src;
 426 struct route *ro;
 427 {
 428         struct sockaddr_ipx *dst;
 429
 430         bzero((caddr_t)ro, sizeof(*ro));
 431         dst = (struct sockaddr_ipx *)&ro->ro_dst;
 432
 433         dst->sipx_len = sizeof(*dst);
 434         dst->sipx_family = AF_IPX;
 435         dst->sipx_addr = *src;
 436         dst->sipx_addr.x_port = 0;
 437         rtalloc(ro);
 438         if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp == NULL) {
 439                 return (0);
 440         }
 441         ro->ro_rt->rt_use++;
 442         return (1);
 443 }
 444
 445 static void
 446 ipx_undo_route(ro)
 447 struct route *ro;
 448 {
 449         if (ro->ro_rt != NULL) {
 450                 RTFREE(ro->ro_rt);
 451         }
 452 }
 453
 454 void
 455 ipx_watch_output(m, ifp)
 456 struct mbuf *m;
 457 struct ifnet *ifp;
 458 {
 459         struct ipxpcb *ipxp;
 460         struct ifaddr *ifa;
 461         struct ipx_ifaddr *ia;
 462         /*
 463          * Give any raw listeners a crack at the packet
 464          */
 465         for (ipxp = ipxrawpcb.ipxp_next; ipxp != &ipxrawpcb;
 466              ipxp = ipxp->ipxp_next) {
 467                 struct mbuf *m0 = m_copy(m, 0, (int)M_COPYALL);
 468                 if (m0 != NULL) {
 469                         struct ipx *ipx;
 470
 471                         M_PREPEND(m0, sizeof(*ipx), M_DONTWAIT);
 472                         if (m0 == NULL)
 473                                 continue;
 474                         ipx = mtod(m0, struct ipx *);
 475                         ipx->ipx_sna.x_net = ipx_zeronet;
 476                         for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
 477                                 if (ifp == ia->ia_ifp)
 478                                         break;
 479                         if (ia == NULL)
 480                                 ipx->ipx_sna.x_host = ipx_zerohost;
 481                         else
 482                                 ipx->ipx_sna.x_host =
 483                                     ia->ia_addr.sipx_addr.x_host;
 484
 485                         if (ifp != NULL && (ifp->if_flags & IFF_POINTOPOINT))
 486                             TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
 487                                 if (ifa->ifa_addr->sa_family == AF_IPX) {
 488                                     ipx->ipx_sna = IA_SIPX(ifa)->sipx_addr;
 489                                     break;
 490                                 }
 491                             }
 492                         ipx->ipx_len = ntohl(m0->m_pkthdr.len);
 493                         ipx_input(m0, ipxp);
 494                 }
 495         }
 496 }