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 1.6 2003/11/08 07:57:52 dillon 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 static int ipxqmaxlen = IFQ_MAXLEN;
  91
  92 long    ipx_pexseq;
  93
  94 static  void ipxintr(struct mbuf *);
  95 static  int ipx_do_route(struct ipx_addr *src, struct route *ro);
  96 static  void ipx_undo_route(struct route *ro);
  97 static  void ipx_forward(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         netisr_register(NETISR_IPX, cpu0_portfn, ipxintr);
 121 }
 122
 123 /*
 124  * IPX input routine.  Pass to next level.
 125  */
 126 static void
 127 ipxintr(struct mbuf *m)
 128 {
 129         struct ipx *ipx;
 130         struct ipxpcb *ipxp;
 131         struct ipx_ifaddr *ia;
 132         int len;
 133
 134         /*
 135          * If no IPX addresses have been set yet but the interfaces
 136          * are receiving, can't do anything with incoming packets yet.
 137          */
 138         if (ipx_ifaddr == NULL)
 139                 goto bad;
 140
 141         ipxstat.ipxs_total++;
 142
 143         if ((m->m_flags & M_EXT || m->m_len < sizeof(struct ipx)) &&
 144             (m = m_pullup(m, sizeof(struct ipx))) == 0) {
 145                 ipxstat.ipxs_toosmall++;
 146                 return;
 147         }
 148
 149         /*
 150          * Give any raw listeners a crack at the packet
 151          */
 152         for (ipxp = ipxrawpcb.ipxp_next; ipxp != &ipxrawpcb;
 153              ipxp = ipxp->ipxp_next) {
 154                 struct mbuf *m1 = m_copy(m, 0, (int)M_COPYALL);
 155                 if (m1 != NULL)
 156                         ipx_input(m1, ipxp);
 157         }
 158
 159         ipx = mtod(m, struct ipx *);
 160         len = ntohs(ipx->ipx_len);
 161         /*
 162          * Check that the amount of data in the buffers
 163          * is as at least much as the IPX header would have us expect.
 164          * Trim mbufs if longer than we expect.
 165          * Drop packet if shorter than we expect.
 166          */
 167         if (m->m_pkthdr.len < len) {
 168                 ipxstat.ipxs_tooshort++;
 169                 goto bad;
 170         }
 171         if (m->m_pkthdr.len > len) {
 172                 if (m->m_len == m->m_pkthdr.len) {
 173                         m->m_len = len;
 174                         m->m_pkthdr.len = len;
 175                 } else
 176                         m_adj(m, len - m->m_pkthdr.len);
 177         }
 178         if (ipxcksum && ipx->ipx_sum != 0xffff) {
 179                 if (ipx->ipx_sum != ipx_cksum(m, len)) {
 180                         ipxstat.ipxs_badsum++;
 181                         goto bad;
 182                 }
 183         }
 184
 185         /*
 186          * Propagated (Netbios) packets (type 20) has to be handled
 187          * different. :-(
 188          */
 189         if (ipx->ipx_pt == IPXPROTO_NETBIOS) {
 190                 if (ipxnetbios) {
 191                         ipx_output_type20(m);
 192                         return;
 193                 } else
 194                         goto bad;
 195         }
 196
 197         /*
 198          * Is this a directed broadcast?
 199          */
 200         if (ipx_hosteqnh(ipx_broadhost,ipx->ipx_dna.x_host)) {
 201                 if ((!ipx_neteq(ipx->ipx_dna, ipx->ipx_sna)) &&
 202                     (!ipx_neteqnn(ipx->ipx_dna.x_net, ipx_broadnet)) &&
 203                     (!ipx_neteqnn(ipx->ipx_sna.x_net, ipx_zeronet)) &&
 204                     (!ipx_neteqnn(ipx->ipx_dna.x_net, ipx_zeronet)) ) {
 205                         /*
 206                          * If it is a broadcast to the net where it was
 207                          * received from, treat it as ours.
 208                          */
 209                         for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
 210                                 if((ia->ia_ifa.ifa_ifp == m->m_pkthdr.rcvif) &&
 211                                    ipx_neteq(ia->ia_addr.sipx_addr,
 212                                              ipx->ipx_dna))
 213                                         goto ours;
 214
 215                         /*
 216                          * Look to see if I need to eat this packet.
 217                          * Algorithm is to forward all young packets
 218                          * and prematurely age any packets which will
 219                          * by physically broadcasted.
 220                          * Any very old packets eaten without forwarding
 221                          * would die anyway.
 222                          *
 223                          * Suggestion of Bill Nesheim, Cornell U.
 224                          */
 225                         if (ipx->ipx_tc < IPX_MAXHOPS) {
 226                                 ipx_forward(m);
 227                                 return;
 228                         }
 229                 }
 230         /*
 231          * Is this our packet? If not, forward.
 232          */
 233         } else {
 234                 for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
 235                         if (ipx_hosteq(ipx->ipx_dna, ia->ia_addr.sipx_addr) &&
 236                             (ipx_neteq(ipx->ipx_dna, ia->ia_addr.sipx_addr) ||
 237                              ipx_neteqnn(ipx->ipx_dna.x_net, ipx_zeronet)))
 238                                 break;
 239
 240                 if (ia == NULL) {
 241                         ipx_forward(m);
 242                         return;
 243                 }
 244         }
 245 ours:
 246         /*
 247          * Locate pcb for datagram.
 248          */
 249         ipxp = ipx_pcblookup(&ipx->ipx_sna, ipx->ipx_dna.x_port, IPX_WILDCARD);
 250         /*
 251          * Switch out to protocol's input routine.
 252          */
 253         if (ipxp != NULL) {
 254                 ipxstat.ipxs_delivered++;
 255                 if ((ipxp->ipxp_flags & IPXP_ALL_PACKETS) == 0)
 256                         switch (ipx->ipx_pt) {
 257                         case IPXPROTO_SPX:
 258                                 spx_input(m, ipxp);
 259                                 return;
 260                         }
 261                 ipx_input(m, ipxp);
 262         } else
 263                 goto bad;
 264
 265         return;
 266
 267 bad:
 268         m_freem(m);
 269 }
 270
 271 void
 272 ipx_ctlinput(cmd, arg_as_sa, dummy)
 273         int cmd;
 274         struct sockaddr *arg_as_sa;     /* XXX should be swapped with dummy */
 275         void *dummy;
 276 {
 277         caddr_t arg = (/* XXX */ caddr_t)arg_as_sa;
 278         struct ipx_addr *ipx;
 279
 280         if (cmd < 0 || cmd > PRC_NCMDS)
 281                 return;
 282         switch (cmd) {
 283                 struct sockaddr_ipx *sipx;
 284
 285         case PRC_IFDOWN:
 286         case PRC_HOSTDEAD:
 287         case PRC_HOSTUNREACH:
 288                 sipx = (struct sockaddr_ipx *)arg;
 289                 if (sipx->sipx_family != AF_IPX)
 290                         return;
 291                 ipx = &sipx->sipx_addr;
 292                 break;
 293
 294         default:
 295                 if (ipxprintfs)
 296                         printf("ipx_ctlinput: cmd %d.\n", cmd);
 297                 break;
 298         }
 299 }
 300
 301 /*
 302  * Forward a packet. If some error occurs drop the packet. IPX don't
 303  * have a way to return errors to the sender.
 304  */
 305
 306 static struct route ipx_droute;
 307 static struct route ipx_sroute;
 308
 309 static void
 310 ipx_forward(m)
 311 struct mbuf *m;
 312 {
 313         struct ipx *ipx = mtod(m, struct ipx *);
 314         int error;
 315         struct mbuf *mcopy = NULL;
 316         int agedelta = 1;
 317         int flags = IPX_FORWARDING;
 318         int ok_there = 0;
 319         int ok_back = 0;
 320
 321         if (ipxforwarding == 0) {
 322                 /* can't tell difference between net and host */
 323                 ipxstat.ipxs_cantforward++;
 324                 m_freem(m);
 325                 goto cleanup;
 326         }
 327         ipx->ipx_tc++;
 328         if (ipx->ipx_tc > IPX_MAXHOPS) {
 329                 ipxstat.ipxs_cantforward++;
 330                 m_freem(m);
 331                 goto cleanup;
 332         }
 333
 334         if ((ok_there = ipx_do_route(&ipx->ipx_dna,&ipx_droute)) == 0) {
 335                 ipxstat.ipxs_noroute++;
 336                 m_freem(m);
 337                 goto cleanup;
 338         }
 339         /*
 340          * Here we think about  forwarding  broadcast packets,
 341          * so we try to insure that it doesn't go back out
 342          * on the interface it came in on.  Also, if we
 343          * are going to physically broadcast this, let us
 344          * age the packet so we can eat it safely the second time around.
 345          */
 346         if (ipx->ipx_dna.x_host.c_host[0] & 0x1) {
 347                 struct ipx_ifaddr *ia = ipx_iaonnetof(&ipx->ipx_dna);
 348                 struct ifnet *ifp;
 349                 if (ia != NULL) {
 350                         /* I'm gonna hafta eat this packet */
 351                         agedelta += IPX_MAXHOPS - ipx->ipx_tc;
 352                         ipx->ipx_tc = IPX_MAXHOPS;
 353                 }
 354                 if ((ok_back = ipx_do_route(&ipx->ipx_sna,&ipx_sroute)) == 0) {
 355                         /* error = ENETUNREACH; He'll never get it! */
 356                         ipxstat.ipxs_noroute++;
 357                         m_freem(m);
 358                         goto cleanup;
 359                 }
 360                 if (ipx_droute.ro_rt &&
 361                     (ifp = ipx_droute.ro_rt->rt_ifp) &&
 362                     ipx_sroute.ro_rt &&
 363                     (ifp != ipx_sroute.ro_rt->rt_ifp)) {
 364                         flags |= IPX_ALLOWBROADCAST;
 365                 } else {
 366                         ipxstat.ipxs_noroute++;
 367                         m_freem(m);
 368                         goto cleanup;
 369                 }
 370         }
 371         /*
 372          * We don't need to recompute checksum because ipx_tc field
 373          * is ignored by checksum calculation routine, however
 374          * it may be desirable to reset checksum if ipxcksum == 0
 375          */
 376 #if 0
 377         if (!ipxcksum)
 378                 ipx->ipx_sum = 0xffff;
 379 #endif
 380
 381         error = ipx_outputfl(m, &ipx_droute, flags);
 382         if (error == 0) {
 383                 ipxstat.ipxs_forward++;
 384
 385                 if (ipxprintfs) {
 386                         printf("forward: ");
 387                         ipx_printhost(&ipx->ipx_sna);
 388                         printf(" to ");
 389                         ipx_printhost(&ipx->ipx_dna);
 390                         printf(" hops %d\n", ipx->ipx_tc);
 391                 }
 392         } else if (mcopy != NULL) {
 393                 ipx = mtod(mcopy, struct ipx *);
 394                 switch (error) {
 395
 396                 case ENETUNREACH:
 397                 case EHOSTDOWN:
 398                 case EHOSTUNREACH:
 399                 case ENETDOWN:
 400                 case EPERM:
 401                         ipxstat.ipxs_noroute++;
 402                         break;
 403
 404                 case EMSGSIZE:
 405                         ipxstat.ipxs_mtutoosmall++;
 406                         break;
 407
 408                 case ENOBUFS:
 409                         ipxstat.ipxs_odropped++;
 410                         break;
 411                 }
 412                 mcopy = NULL;
 413                 m_freem(m);
 414         }
 415 cleanup:
 416         if (ok_there)
 417                 ipx_undo_route(&ipx_droute);
 418         if (ok_back)
 419                 ipx_undo_route(&ipx_sroute);
 420         if (mcopy != NULL)
 421                 m_freem(mcopy);
 422 }
 423
 424 static int
 425 ipx_do_route(src, ro)
 426 struct ipx_addr *src;
 427 struct route *ro;
 428 {
 429         struct sockaddr_ipx *dst;
 430
 431         bzero((caddr_t)ro, sizeof(*ro));
 432         dst = (struct sockaddr_ipx *)&ro->ro_dst;
 433
 434         dst->sipx_len = sizeof(*dst);
 435         dst->sipx_family = AF_IPX;
 436         dst->sipx_addr = *src;
 437         dst->sipx_addr.x_port = 0;
 438         rtalloc(ro);
 439         if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp == NULL) {
 440                 return (0);
 441         }
 442         ro->ro_rt->rt_use++;
 443         return (1);
 444 }
 445
 446 static void
 447 ipx_undo_route(ro)
 448 struct route *ro;
 449 {
 450         if (ro->ro_rt != NULL) {
 451                 RTFREE(ro->ro_rt);
 452         }
 453 }
 454
 455 void
 456 ipx_watch_output(m, ifp)
 457 struct mbuf *m;
 458 struct ifnet *ifp;
 459 {
 460         struct ipxpcb *ipxp;
 461         struct ifaddr *ifa;
 462         struct ipx_ifaddr *ia;
 463         /*
 464          * Give any raw listeners a crack at the packet
 465          */
 466         for (ipxp = ipxrawpcb.ipxp_next; ipxp != &ipxrawpcb;
 467              ipxp = ipxp->ipxp_next) {
 468                 struct mbuf *m0 = m_copy(m, 0, (int)M_COPYALL);
 469                 if (m0 != NULL) {
 470                         struct ipx *ipx;
 471
 472                         M_PREPEND(m0, sizeof(*ipx), M_DONTWAIT);
 473                         if (m0 == NULL)
 474                                 continue;
 475                         ipx = mtod(m0, struct ipx *);
 476                         ipx->ipx_sna.x_net = ipx_zeronet;
 477                         for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
 478                                 if (ifp == ia->ia_ifp)
 479                                         break;
 480                         if (ia == NULL)
 481                                 ipx->ipx_sna.x_host = ipx_zerohost;
 482                         else
 483                                 ipx->ipx_sna.x_host =
 484                                     ia->ia_addr.sipx_addr.x_host;
 485
 486                         if (ifp != NULL && (ifp->if_flags & IFF_POINTOPOINT))
 487                             TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
 488                                 if (ifa->ifa_addr->sa_family == AF_IPX) {
 489                                     ipx->ipx_sna = IA_SIPX(ifa)->sipx_addr;
 490                                     break;
 491                                 }
 492                             }
 493                         ipx->ipx_len = ntohl(m0->m_pkthdr.len);
 494                         ipx_input(m0, ipxp);
 495                 }
 496         }
 497 }