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 1.20 2008/09/24 14:26:39 sephe 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 #include <sys/mplock2.h>
  52
  53 #include <net/if.h>
  54 #include <net/route.h>
  55 #include <net/netisr.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  ipxpcbhead ipxpcb_list;
  91 struct  ipxpcbhead ipxrawpcb_list;
  92
  93 long    ipx_pexseq;
  94
  95 static  void ipxintr(netmsg_t msg);
  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(void)
 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         LIST_INIT(&ipxpcb_list);
 112         LIST_INIT(&ipxrawpcb_list);
 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, ipxintr, NULL);
 122 }
 123
 124 /*
 125  * IPX input routine.  Pass to next level.
 126  */
 127 static void
 128 ipxintr(netmsg_t msg)
 129 {
 130         struct mbuf *m = msg->packet.nm_packet;
 131         struct ipx *ipx;
 132         struct ipxpcb *ipxp;
 133         struct ipx_ifaddr *ia;
 134         int len;
 135
 136         get_mplock();
 137
 138         /*
 139          * If no IPX addresses have been set yet but the interfaces
 140          * are receiving, can't do anything with incoming packets yet.
 141          */
 142         if (ipx_ifaddr == NULL)
 143                 goto bad;
 144
 145         ipxstat.ipxs_total++;
 146
 147         if ((m->m_flags & M_EXT || m->m_len < sizeof(struct ipx)) &&
 148             (m = m_pullup(m, sizeof(struct ipx))) == 0) {
 149                 ipxstat.ipxs_toosmall++;
 150                 goto out;
 151         }
 152
 153         /*
 154          * Give any raw listeners a crack at the packet
 155          */
 156         LIST_FOREACH(ipxp, &ipxrawpcb_list, ipxp_list) {
 157                 struct mbuf *m1 = m_copy(m, 0, (int)M_COPYALL);
 158                 if (m1 != NULL)
 159                         ipx_input(m1, ipxp);
 160         }
 161
 162         ipx = mtod(m, struct ipx *);
 163         len = ntohs(ipx->ipx_len);
 164         /*
 165          * Check that the amount of data in the buffers
 166          * is as at least much as the IPX header would have us expect.
 167          * Trim mbufs if longer than we expect.
 168          * Drop packet if shorter than we expect.
 169          */
 170         if (m->m_pkthdr.len < len) {
 171                 ipxstat.ipxs_tooshort++;
 172                 goto bad;
 173         }
 174         if (m->m_pkthdr.len > len) {
 175                 if (m->m_len == m->m_pkthdr.len) {
 176                         m->m_len = len;
 177                         m->m_pkthdr.len = len;
 178                 } else
 179                         m_adj(m, len - m->m_pkthdr.len);
 180         }
 181         if (ipxcksum && ipx->ipx_sum != 0xffff) {
 182                 if (ipx->ipx_sum != ipx_cksum(m, len)) {
 183                         ipxstat.ipxs_badsum++;
 184                         goto bad;
 185                 }
 186         }
 187
 188         /*
 189          * Propagated (Netbios) packets (type 20) has to be handled
 190          * different. :-(
 191          */
 192         if (ipx->ipx_pt == IPXPROTO_NETBIOS) {
 193                 if (ipxnetbios) {
 194                         ipx_output_type20(m);
 195                         goto out;
 196                 } else
 197                         goto bad;
 198         }
 199
 200         /*
 201          * Is this a directed broadcast?
 202          */
 203         if (ipx_hosteqnh(ipx_broadhost,ipx->ipx_dna.x_host)) {
 204                 if ((!ipx_neteq(ipx->ipx_dna, ipx->ipx_sna)) &&
 205                     (!ipx_neteqnn(ipx->ipx_dna.x_net, ipx_broadnet)) &&
 206                     (!ipx_neteqnn(ipx->ipx_sna.x_net, ipx_zeronet)) &&
 207                     (!ipx_neteqnn(ipx->ipx_dna.x_net, ipx_zeronet)) ) {
 208                         /*
 209                          * If it is a broadcast to the net where it was
 210                          * received from, treat it as ours.
 211                          */
 212                         for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
 213                                 if((ia->ia_ifa.ifa_ifp == m->m_pkthdr.rcvif) &&
 214                                    ipx_neteq(ia->ia_addr.sipx_addr,
 215                                              ipx->ipx_dna))
 216                                         goto ours;
 217
 218                         /*
 219                          * Look to see if I need to eat this packet.
 220                          * Algorithm is to forward all young packets
 221                          * and prematurely age any packets which will
 222                          * by physically broadcasted.
 223                          * Any very old packets eaten without forwarding
 224                          * would die anyway.
 225                          *
 226                          * Suggestion of Bill Nesheim, Cornell U.
 227                          */
 228                         if (ipx->ipx_tc < IPX_MAXHOPS) {
 229                                 ipx_forward(m);
 230                                 goto out;
 231                         }
 232                 }
 233         /*
 234          * Is this our packet? If not, forward.
 235          */
 236         } else {
 237                 for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
 238                         if (ipx_hosteq(ipx->ipx_dna, ia->ia_addr.sipx_addr) &&
 239                             (ipx_neteq(ipx->ipx_dna, ia->ia_addr.sipx_addr) ||
 240                              ipx_neteqnn(ipx->ipx_dna.x_net, ipx_zeronet)))
 241                                 break;
 242
 243                 if (ia == NULL) {
 244                         ipx_forward(m);
 245                         goto out;
 246                 }
 247         }
 248 ours:
 249         /*
 250          * Locate pcb for datagram.
 251          */
 252         ipxp = ipx_pcblookup(&ipx->ipx_sna, ipx->ipx_dna.x_port, IPX_WILDCARD);
 253         /*
 254          * Switch out to protocol's input routine.
 255          */
 256         if (ipxp != NULL) {
 257                 ipxstat.ipxs_delivered++;
 258                 if ((ipxp->ipxp_flags & IPXP_ALL_PACKETS) == 0)
 259                         switch (ipx->ipx_pt) {
 260                         case IPXPROTO_SPX:
 261                                 spx_input(m, ipxp);
 262                                 goto out;
 263                         }
 264                 ipx_input(m, ipxp);
 265         } else
 266                 goto bad;
 267
 268         goto out;
 269
 270 bad:
 271         m_freem(m);
 272 out:
 273         rel_mplock();
 274         /* msg was embedded in the mbuf, do not reply! */
 275 }
 276
 277 /*
 278  * Parameters:
 279  *      arg_as_sa:      XXX should be swapped with dummy
 280  */
 281 void
 282 ipx_ctlinput(netmsg_t msg)
 283 {
 284         int cmd = msg->ctlinput.nm_cmd;
 285         struct sockaddr *arg_as_sa = msg->ctlinput.nm_arg;
 286         caddr_t arg = (/* XXX */ caddr_t)arg_as_sa;
 287         struct ipx_addr *ipx;
 288         struct sockaddr_ipx *sipx;
 289
 290         if (cmd < 0 || cmd > PRC_NCMDS)
 291                 goto out;
 292
 293         switch (cmd) {
 294         case PRC_IFDOWN:
 295         case PRC_HOSTDEAD:
 296         case PRC_HOSTUNREACH:
 297                 sipx = (struct sockaddr_ipx *)arg;
 298                 if (sipx->sipx_family != AF_IPX)
 299                         break;
 300                 ipx = &sipx->sipx_addr;
 301                 break;
 302
 303         default:
 304                 if (ipxprintfs)
 305                         kprintf("ipx_ctlinput: cmd %d.\n", cmd);
 306                 break;
 307         }
 308 out:
 309         lwkt_replymsg(&msg->lmsg, 0);
 310 }
 311
 312 /*
 313  * Forward a packet. If some error occurs drop the packet. IPX don't
 314  * have a way to return errors to the sender.
 315  */
 316
 317 static struct route ipx_droute;
 318 static struct route ipx_sroute;
 319
 320 static void
 321 ipx_forward(struct mbuf *m)
 322 {
 323         struct ipx *ipx = mtod(m, struct ipx *);
 324         int error;
 325         struct mbuf *mcopy = NULL;
 326         int agedelta = 1;
 327         int flags = IPX_FORWARDING;
 328         int ok_there = 0;
 329         int ok_back = 0;
 330
 331         if (ipxforwarding == 0) {
 332                 /* can't tell difference between net and host */
 333                 ipxstat.ipxs_cantforward++;
 334                 m_freem(m);
 335                 goto cleanup;
 336         }
 337         ipx->ipx_tc++;
 338         if (ipx->ipx_tc > IPX_MAXHOPS) {
 339                 ipxstat.ipxs_cantforward++;
 340                 m_freem(m);
 341                 goto cleanup;
 342         }
 343
 344         if ((ok_there = ipx_do_route(&ipx->ipx_dna,&ipx_droute)) == 0) {
 345                 ipxstat.ipxs_noroute++;
 346                 m_freem(m);
 347                 goto cleanup;
 348         }
 349         /*
 350          * Here we think about  forwarding  broadcast packets,
 351          * so we try to insure that it doesn't go back out
 352          * on the interface it came in on.  Also, if we
 353          * are going to physically broadcast this, let us
 354          * age the packet so we can eat it safely the second time around.
 355          */
 356         if (ipx->ipx_dna.x_host.c_host[0] & 0x1) {
 357                 struct ipx_ifaddr *ia = ipx_iaonnetof(&ipx->ipx_dna);
 358                 struct ifnet *ifp;
 359                 if (ia != NULL) {
 360                         /* I'm gonna hafta eat this packet */
 361                         agedelta += IPX_MAXHOPS - ipx->ipx_tc;
 362                         ipx->ipx_tc = IPX_MAXHOPS;
 363                 }
 364                 if ((ok_back = ipx_do_route(&ipx->ipx_sna,&ipx_sroute)) == 0) {
 365                         /* error = ENETUNREACH; He'll never get it! */
 366                         ipxstat.ipxs_noroute++;
 367                         m_freem(m);
 368                         goto cleanup;
 369                 }
 370                 if (ipx_droute.ro_rt &&
 371                     (ifp = ipx_droute.ro_rt->rt_ifp) &&
 372                     ipx_sroute.ro_rt &&
 373                     (ifp != ipx_sroute.ro_rt->rt_ifp)) {
 374                         flags |= IPX_ALLOWBROADCAST;
 375                 } else {
 376                         ipxstat.ipxs_noroute++;
 377                         m_freem(m);
 378                         goto cleanup;
 379                 }
 380         }
 381         /*
 382          * We don't need to recompute checksum because ipx_tc field
 383          * is ignored by checksum calculation routine, however
 384          * it may be desirable to reset checksum if ipxcksum == 0
 385          */
 386 #if 0
 387         if (!ipxcksum)
 388                 ipx->ipx_sum = 0xffff;
 389 #endif
 390
 391         error = ipx_outputfl(m, &ipx_droute, flags);
 392         if (error == 0) {
 393                 ipxstat.ipxs_forward++;
 394
 395                 if (ipxprintfs) {
 396                         kprintf("forward: ");
 397                         ipx_printhost(&ipx->ipx_sna);
 398                         kprintf(" to ");
 399                         ipx_printhost(&ipx->ipx_dna);
 400                         kprintf(" hops %d\n", ipx->ipx_tc);
 401                 }
 402         } else if (mcopy != NULL) {
 403                 ipx = mtod(mcopy, struct ipx *);
 404                 switch (error) {
 405
 406                 case ENETUNREACH:
 407                 case EHOSTDOWN:
 408                 case EHOSTUNREACH:
 409                 case ENETDOWN:
 410                 case EPERM:
 411                         ipxstat.ipxs_noroute++;
 412                         break;
 413
 414                 case EMSGSIZE:
 415                         ipxstat.ipxs_mtutoosmall++;
 416                         break;
 417
 418                 case ENOBUFS:
 419                         ipxstat.ipxs_odropped++;
 420                         break;
 421                 }
 422                 mcopy = NULL;
 423                 m_freem(m);
 424         }
 425 cleanup:
 426         if (ok_there)
 427                 ipx_undo_route(&ipx_droute);
 428         if (ok_back)
 429                 ipx_undo_route(&ipx_sroute);
 430         if (mcopy != NULL)
 431                 m_freem(mcopy);
 432 }
 433
 434 static int
 435 ipx_do_route(struct ipx_addr *src, struct route *ro)
 436 {
 437         struct sockaddr_ipx *dst;
 438
 439         bzero((caddr_t)ro, sizeof(*ro));
 440         dst = (struct sockaddr_ipx *)&ro->ro_dst;
 441
 442         dst->sipx_len = sizeof(*dst);
 443         dst->sipx_family = AF_IPX;
 444         dst->sipx_addr = *src;
 445         dst->sipx_addr.x_port = 0;
 446         rtalloc(ro);
 447         if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp == NULL) {
 448                 return (0);
 449         }
 450         ro->ro_rt->rt_use++;
 451         return (1);
 452 }
 453
 454 static void
 455 ipx_undo_route(struct route *ro)
 456 {
 457         if (ro->ro_rt != NULL) {
 458                 RTFREE(ro->ro_rt);
 459         }
 460 }
 461
 462 void
 463 ipx_watch_output(struct mbuf *m, struct ifnet *ifp)
 464 {
 465         struct ipxpcb *ipxp;
 466         struct ipx_ifaddr *ia;
 467
 468         /*
 469          * Give any raw listeners a crack at the packet
 470          */
 471         LIST_FOREACH(ipxp, &ipxrawpcb_list, ipxp_list) {
 472                 struct mbuf *m0 = m_copy(m, 0, (int)M_COPYALL);
 473                 if (m0 != NULL) {
 474                         struct ipx *ipx;
 475
 476                         M_PREPEND(m0, sizeof(*ipx), MB_DONTWAIT);
 477                         if (m0 == NULL)
 478                                 continue;
 479                         ipx = mtod(m0, struct ipx *);
 480                         ipx->ipx_sna.x_net = ipx_zeronet;
 481                         for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
 482                                 if (ifp == ia->ia_ifp)
 483                                         break;
 484                         if (ia == NULL)
 485                                 ipx->ipx_sna.x_host = ipx_zerohost;
 486                         else
 487                                 ipx->ipx_sna.x_host =
 488                                     ia->ia_addr.sipx_addr.x_host;
 489
 490                         if (ifp != NULL && (ifp->if_flags & IFF_POINTOPOINT)) {
 491                             struct ifaddr_container *ifac;
 492
 493                             TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid],
 494                                           ifa_link) {
 495                                 struct ifaddr *ifa = ifac->ifa;
 496
 497                                 if (ifa->ifa_addr->sa_family == AF_IPX) {
 498                                     ipx->ipx_sna = IA_SIPX(ifa)->sipx_addr;
 499                                     break;
 500                                 }
 501                             }
 502                         }
 503                         ipx->ipx_len = ntohl(m0->m_pkthdr.len);
 504                         ipx_input(m0, ipxp);
 505                 }
 506         }
 507 }