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. Neither the name of the University nor the names of its contributors
  15  *    may be used to endorse or promote products derived from this software
  16  *    without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  28  * SUCH DAMAGE.
  29  *
  30  *      @(#)ipx_input.c
  31  *
  32  * $FreeBSD: src/sys/netipx/ipx_input.c,v 1.22.2.2 2001/02/22 09:44:18 bp Exp $
  33  */
  34
  35 #include <sys/param.h>
  36 #include <sys/systm.h>
  37 #include <sys/mbuf.h>
  38 #include <sys/protosw.h>
  39 #include <sys/socket.h>
  40 #include <sys/kernel.h>
  41 #include <sys/random.h>
  42 #include <sys/sysctl.h>
  43
  44 #include <sys/thread2.h>
  45 #include <sys/msgport2.h>
  46 #include <sys/mplock2.h>
  47
  48 #include <net/if.h>
  49 #include <net/route.h>
  50 #include <net/netisr.h>
  51
  52 #include "ipx.h"
  53 #include "spx.h"
  54 #include "ipx_if.h"
  55 #include "ipx_pcb.h"
  56 #include "ipx_var.h"
  57
  58 int     ipxcksum = 0;
  59 SYSCTL_INT(_net_ipx_ipx, OID_AUTO, checksum, CTLFLAG_RW,
  60            &ipxcksum, 0, "");
  61
  62 static int      ipxprintfs = 0;         /* printing forwarding information */
  63 SYSCTL_INT(_net_ipx_ipx, OID_AUTO, ipxprintfs, CTLFLAG_RW,
  64            &ipxprintfs, 0, "");
  65
  66 static int      ipxforwarding = 0;
  67 SYSCTL_INT(_net_ipx_ipx, OID_AUTO, ipxforwarding, CTLFLAG_RW,
  68             &ipxforwarding, 0, "");
  69
  70 static int      ipxnetbios = 0;
  71 SYSCTL_INT(_net_ipx, OID_AUTO, ipxnetbios, CTLFLAG_RW,
  72            &ipxnetbios, 0, "");
  73
  74 union   ipx_net ipx_zeronet;
  75 union   ipx_host ipx_zerohost;
  76
  77 union   ipx_net ipx_broadnet;
  78 union   ipx_host ipx_broadhost;
  79
  80 struct  ipxstat ipxstat;
  81 struct  sockaddr_ipx ipx_netmask, ipx_hostmask;
  82
  83 static  u_short allones[] = {-1, -1, -1};
  84
  85 struct  ipxpcbhead ipxpcb_list;
  86 struct  ipxpcbhead ipxrawpcb_list;
  87
  88 long    ipx_pexseq;
  89
  90 static  void ipxintr(netmsg_t msg);
  91 static  int ipx_do_route(struct ipx_addr *src, struct route *ro);
  92 static  void ipx_undo_route(struct route *ro);
  93 static  void ipx_forward(struct mbuf *m);
  94
  95 /*
  96  * IPX initialization.
  97  */
  98
  99 void
 100 ipx_init(void)
 101 {
 102         ipx_broadnet = *(union ipx_net *)allones;
 103         ipx_broadhost = *(union ipx_host *)allones;
 104
 105         read_random(&ipx_pexseq, sizeof ipx_pexseq);
 106         LIST_INIT(&ipxpcb_list);
 107         LIST_INIT(&ipxrawpcb_list);
 108
 109         ipx_netmask.sipx_len = 6;
 110         ipx_netmask.sipx_addr.x_net = ipx_broadnet;
 111
 112         ipx_hostmask.sipx_len = 12;
 113         ipx_hostmask.sipx_addr.x_net = ipx_broadnet;
 114         ipx_hostmask.sipx_addr.x_host = ipx_broadhost;
 115
 116         netisr_register(NETISR_IPX, ipxintr, NULL);
 117 }
 118
 119 /*
 120  * IPX input routine.  Pass to next level.
 121  */
 122 static void
 123 ipxintr(netmsg_t msg)
 124 {
 125         struct mbuf *m = msg->packet.nm_packet;
 126         struct ipx *ipx;
 127         struct ipxpcb *ipxp;
 128         struct ipx_ifaddr *ia;
 129         int len;
 130
 131         get_mplock();
 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))) == NULL) {
 144                 ipxstat.ipxs_toosmall++;
 145                 goto out;
 146         }
 147
 148         /*
 149          * Give any raw listeners a crack at the packet
 150          */
 151         LIST_FOREACH(ipxp, &ipxrawpcb_list, ipxp_list) {
 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                         goto out;
 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                                 goto out;
 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                         goto out;
 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                                 goto out;
 258                         }
 259                 ipx_input(m, ipxp);
 260         } else
 261                 goto bad;
 262
 263         goto out;
 264
 265 bad:
 266         m_freem(m);
 267 out:
 268         rel_mplock();
 269         /* msg was embedded in the mbuf, do not reply! */
 270 }
 271
 272 /*
 273  * Parameters:
 274  *      arg_as_sa:      XXX should be swapped with dummy
 275  */
 276 void
 277 ipx_ctlinput(netmsg_t msg)
 278 {
 279         int cmd = msg->ctlinput.nm_cmd;
 280         struct sockaddr *arg_as_sa = msg->ctlinput.nm_arg;
 281         caddr_t arg = (/* XXX */ caddr_t)arg_as_sa;
 282         struct sockaddr_ipx *sipx;
 283
 284         if (cmd < 0 || cmd > PRC_NCMDS)
 285                 goto out;
 286
 287         switch (cmd) {
 288         case PRC_IFDOWN:
 289         case PRC_HOSTDEAD:
 290         case PRC_HOSTUNREACH:
 291                 sipx = (struct sockaddr_ipx *)arg;
 292                 if (sipx->sipx_family != AF_IPX)
 293                         break;
 294                 break;
 295
 296         default:
 297                 if (ipxprintfs)
 298                         kprintf("ipx_ctlinput: cmd %d.\n", cmd);
 299                 break;
 300         }
 301 out:
 302         lwkt_replymsg(&msg->lmsg, 0);
 303 }
 304
 305 /*
 306  * Forward a packet. If some error occurs drop the packet. IPX don't
 307  * have a way to return errors to the sender.
 308  */
 309
 310 static struct route ipx_droute;
 311 static struct route ipx_sroute;
 312
 313 static void
 314 ipx_forward(struct mbuf *m)
 315 {
 316         struct ipx *ipx = mtod(m, struct ipx *);
 317         int error;
 318         struct mbuf *mcopy = NULL;
 319         int agedelta = 1;
 320         int flags = IPX_FORWARDING;
 321         int ok_there = 0;
 322         int ok_back = 0;
 323
 324         if (ipxforwarding == 0) {
 325                 /* can't tell difference between net and host */
 326                 ipxstat.ipxs_cantforward++;
 327                 m_freem(m);
 328                 goto cleanup;
 329         }
 330         ipx->ipx_tc++;
 331         if (ipx->ipx_tc > IPX_MAXHOPS) {
 332                 ipxstat.ipxs_cantforward++;
 333                 m_freem(m);
 334                 goto cleanup;
 335         }
 336
 337         if ((ok_there = ipx_do_route(&ipx->ipx_dna,&ipx_droute)) == 0) {
 338                 ipxstat.ipxs_noroute++;
 339                 m_freem(m);
 340                 goto cleanup;
 341         }
 342         /*
 343          * Here we think about  forwarding  broadcast packets,
 344          * so we try to insure that it doesn't go back out
 345          * on the interface it came in on.  Also, if we
 346          * are going to physically broadcast this, let us
 347          * age the packet so we can eat it safely the second time around.
 348          */
 349         if (ipx->ipx_dna.x_host.c_host[0] & 0x1) {
 350                 struct ipx_ifaddr *ia = ipx_iaonnetof(&ipx->ipx_dna);
 351                 struct ifnet *ifp;
 352                 if (ia != NULL) {
 353                         /* I'm gonna hafta eat this packet */
 354                         agedelta += IPX_MAXHOPS - ipx->ipx_tc;
 355                         ipx->ipx_tc = IPX_MAXHOPS;
 356                 }
 357                 if ((ok_back = ipx_do_route(&ipx->ipx_sna,&ipx_sroute)) == 0) {
 358                         /* error = ENETUNREACH; He'll never get it! */
 359                         ipxstat.ipxs_noroute++;
 360                         m_freem(m);
 361                         goto cleanup;
 362                 }
 363                 if (ipx_droute.ro_rt &&
 364                     (ifp = ipx_droute.ro_rt->rt_ifp) &&
 365                     ipx_sroute.ro_rt &&
 366                     (ifp != ipx_sroute.ro_rt->rt_ifp)) {
 367                         flags |= IPX_ALLOWBROADCAST;
 368                 } else {
 369                         ipxstat.ipxs_noroute++;
 370                         m_freem(m);
 371                         goto cleanup;
 372                 }
 373         }
 374         /*
 375          * We don't need to recompute checksum because ipx_tc field
 376          * is ignored by checksum calculation routine, however
 377          * it may be desirable to reset checksum if ipxcksum == 0
 378          */
 379 #if 0
 380         if (!ipxcksum)
 381                 ipx->ipx_sum = 0xffff;
 382 #endif
 383
 384         error = ipx_outputfl(m, &ipx_droute, flags);
 385         if (error == 0) {
 386                 ipxstat.ipxs_forward++;
 387
 388                 if (ipxprintfs) {
 389                         kprintf("forward: ");
 390                         ipx_printhost(&ipx->ipx_sna);
 391                         kprintf(" to ");
 392                         ipx_printhost(&ipx->ipx_dna);
 393                         kprintf(" hops %d\n", ipx->ipx_tc);
 394                 }
 395         } else if (mcopy != NULL) {
 396                 ipx = mtod(mcopy, struct ipx *);
 397                 switch (error) {
 398
 399                 case ENETUNREACH:
 400                 case EHOSTDOWN:
 401                 case EHOSTUNREACH:
 402                 case ENETDOWN:
 403                 case EPERM:
 404                         ipxstat.ipxs_noroute++;
 405                         break;
 406
 407                 case EMSGSIZE:
 408                         ipxstat.ipxs_mtutoosmall++;
 409                         break;
 410
 411                 case ENOBUFS:
 412                         ipxstat.ipxs_odropped++;
 413                         break;
 414                 }
 415                 mcopy = NULL;
 416                 m_freem(m);
 417         }
 418 cleanup:
 419         if (ok_there)
 420                 ipx_undo_route(&ipx_droute);
 421         if (ok_back)
 422                 ipx_undo_route(&ipx_sroute);
 423         if (mcopy != NULL)
 424                 m_freem(mcopy);
 425 }
 426
 427 static int
 428 ipx_do_route(struct ipx_addr *src, struct route *ro)
 429 {
 430         struct sockaddr_ipx *dst;
 431
 432         bzero((caddr_t)ro, sizeof(*ro));
 433         dst = (struct sockaddr_ipx *)&ro->ro_dst;
 434
 435         dst->sipx_len = sizeof(*dst);
 436         dst->sipx_family = AF_IPX;
 437         dst->sipx_addr = *src;
 438         dst->sipx_addr.x_port = 0;
 439         rtalloc(ro);
 440         if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp == NULL) {
 441                 return (0);
 442         }
 443         ro->ro_rt->rt_use++;
 444         return (1);
 445 }
 446
 447 static void
 448 ipx_undo_route(struct route *ro)
 449 {
 450         if (ro->ro_rt != NULL) {
 451                 RTFREE(ro->ro_rt);
 452         }
 453 }
 454
 455 void
 456 ipx_watch_output(struct mbuf *m, struct ifnet *ifp)
 457 {
 458         struct ipxpcb *ipxp;
 459         struct ipx_ifaddr *ia;
 460
 461         /*
 462          * Give any raw listeners a crack at the packet
 463          */
 464         LIST_FOREACH(ipxp, &ipxrawpcb_list, ipxp_list) {
 465                 struct mbuf *m0 = m_copy(m, 0, (int)M_COPYALL);
 466                 if (m0 != NULL) {
 467                         struct ipx *ipx;
 468
 469                         M_PREPEND(m0, sizeof(*ipx), MB_DONTWAIT);
 470                         if (m0 == NULL)
 471                                 continue;
 472                         ipx = mtod(m0, struct ipx *);
 473                         ipx->ipx_sna.x_net = ipx_zeronet;
 474                         for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
 475                                 if (ifp == ia->ia_ifp)
 476                                         break;
 477                         if (ia == NULL)
 478                                 ipx->ipx_sna.x_host = ipx_zerohost;
 479                         else
 480                                 ipx->ipx_sna.x_host =
 481                                     ia->ia_addr.sipx_addr.x_host;
 482
 483                         if (ifp != NULL && (ifp->if_flags & IFF_POINTOPOINT)) {
 484                             struct ifaddr_container *ifac;
 485
 486                             TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid],
 487                                           ifa_link) {
 488                                 struct ifaddr *ifa = ifac->ifa;
 489
 490                                 if (ifa->ifa_addr->sa_family == AF_IPX) {
 491                                     ipx->ipx_sna = IA_SIPX(ifa)->sipx_addr;
 492                                     break;
 493                                 }
 494                             }
 495                         }
 496                         ipx->ipx_len = ntohl(m0->m_pkthdr.len);
 497                         ipx_input(m0, ipxp);
 498                 }
 499         }
 500 }