usr.sbin/IPXrouted/sap_output.c

   1 /*
   2  * Copyright (c) 1995 John Hay.  All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  * 3. All advertising materials mentioning features or use of this software
  13  *    must display the following acknowledgement:
  14  *      This product includes software developed by John Hay.
  15  * 4. Neither the name of the author nor the names of any co-contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY John Hay AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL John Hay OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  * $FreeBSD: src/usr.sbin/IPXrouted/sap_output.c,v 1.9 1999/08/28 01:15:04 peter Exp $
  32  * $DragonFly: src/usr.sbin/IPXrouted/sap_output.c,v 1.4 2004/06/19 20:38:22 joerg Exp $
  33  */
  34
  35 /*
  36  * Routing Table Management Daemon
  37  */
  38 #include <unistd.h>
  39 #include "defs.h"
  40
  41 /*
  42  * Apply the function "f" to all non-passive
  43  * interfaces.  If the interface supports the
  44  * use of broadcasting use it, otherwise address
  45  * the output to the known router.
  46  */
  47 void
  48 sap_supply_toall(int changesonly)
  49 {
  50         struct interface *ifp;
  51         struct sockaddr dst;
  52         struct sockaddr_ipx *ipx_dst;
  53         int flags;
  54         extern struct interface *ifnet;
  55
  56         ipx_dst = (struct sockaddr_ipx *)&dst;
  57
  58         for (ifp = ifnet; ifp; ifp = ifp->int_next) {
  59                 if (ifp->int_flags & IFF_PASSIVE)
  60                         continue;
  61
  62                 dst = ifp->int_flags & IFF_BROADCAST ? ifp->int_broadaddr :
  63                       ifp->int_flags & IFF_POINTOPOINT ? ifp->int_dstaddr :
  64                       ifp->int_addr;
  65
  66                 ipx_dst->sipx_addr.x_port = htons(IPXPORT_SAP);
  67
  68                 flags = ifp->int_flags & IFF_INTERFACE ? MSG_DONTROUTE : 0;
  69                 sap_supply(&dst, flags, ifp, SAP_WILDCARD, changesonly);
  70         }
  71 }
  72
  73 void
  74 sapsndmsg(struct sockaddr *dst, int flags, struct interface *ifp,
  75           int changesonly)
  76 {
  77         struct sockaddr t_dst;
  78         struct sockaddr_ipx *ipx_dst;
  79
  80         t_dst = *dst;
  81         ipx_dst = (struct sockaddr_ipx *)&t_dst;
  82
  83         if (ipx_dst->sipx_addr.x_port == 0)
  84                 ipx_dst->sipx_addr.x_port = htons(IPXPORT_SAP);
  85
  86         (*afswitch[dst->sa_family].af_output)
  87                 (sapsock, flags, &t_dst,
  88                 sizeof (struct sap_packet) + sizeof(u_short));
  89         TRACE_SAP_OUTPUT(ifp, &t_dst,
  90                          sizeof (struct sap_packet) + sizeof(u_short));
  91 }
  92
  93 /*
  94  * Supply dst with the contents of the SAP tables. If the ServType ==
  95  * SAP_WILDCARD (0xFFFF) supply the whole table, otherwise only the
  96  * services that are of ServType. If this won't fit in one packet, chop
  97  * it up into several.
  98  *
  99  * This must be done using the split horizon algorithm.
 100  * 1. Don't send SAP info to the interface from where it was received.
 101  * 2. If a service is received from more than one interface and the cost is
 102  *    the same, don't publish it on either interface. I am calling this
 103  *    clones.
 104  */
 105 void
 106 sap_supply(struct sockaddr *dst, int flags, struct interface *ifp,
 107            int ServType, int changesonly)
 108 {
 109         struct sap_entry *sap;
 110         struct sap_entry *csap; /* Clone route */
 111         struct sap_hash *sh;
 112         struct sap_info *n = sap_msg->sap;
 113         struct sap_hash *base = sap_head;
 114         struct sockaddr_ipx *sipx =  (struct sockaddr_ipx *) dst;
 115         af_output_t *output = afswitch[dst->sa_family].af_output;
 116         int size, metric;
 117         int delay = 0;
 118
 119         if (sipx->sipx_port == 0)
 120                 sipx->sipx_port = htons(IPXPORT_SAP);
 121
 122         sap_msg->sap_cmd = ntohs(SAP_RESP);
 123
 124         for (sh = base; sh < &base[SAPHASHSIZ]; sh++)
 125         for (sap = sh->forw; sap != (struct sap_entry *)sh; sap = sap->forw) {
 126                 size = (char *)n - (char *)sap_msg;
 127                 if (size >= ((MAXSAPENTRIES * sizeof (struct sap_info)) +
 128                                 sizeof (sap_msg->sap_cmd))) {
 129                         (*output)(sapsock, flags, dst, size);
 130                         TRACE_SAP_OUTPUT(ifp, dst, size);
 131                         n = sap_msg->sap;
 132                         delay++;
 133                         if(delay == 2) {
 134                                 usleep(50000);
 135                                 delay = 0;
 136                         }
 137                 }
 138
 139                 if (changesonly && !(sap->state & RTS_CHANGED))
 140                         continue;
 141
 142                 /*
 143                  * Check for the servicetype except if the ServType is
 144                  * a wildcard (0xFFFF).
 145                  */
 146                 if ((ServType != SAP_WILDCARD) &&
 147                     (ServType != sap->sap.ServType))
 148                         continue;
 149
 150                 /*
 151                  * This should do rule one and two of the split horizon
 152                  * algorithm.
 153                  */
 154                 if (sap->ifp == ifp)
 155                         continue;
 156
 157                 /*
 158                  * Rule 2.
 159                  * Look if we have clones (different routes to the same
 160                  * place with exactly the same cost).
 161                  *
 162                  * We should not publish on any of the clone interfaces.
 163                  */
 164                 csap = sap->clone;
 165                 while (csap) {
 166                         if (csap->ifp == ifp)
 167                                 goto next;
 168                         csap = csap->clone;
 169                 }
 170
 171                 /*
 172                  * Don't advertise services with more than 15 hops. It
 173                  * will be confused with a service that has gone down.
 174                  */
 175                 if (ntohs(sap->sap.hops) == (HOPCNT_INFINITY - 1))
 176                         continue;
 177                 metric = min(ntohs(sap->sap.hops) + 1, HOPCNT_INFINITY);
 178
 179                 *n = sap->sap;
 180                 n->hops = htons(metric);
 181                 n++;
 182 next:
 183                 ;
 184         }
 185         if (n != sap_msg->sap) {
 186                 size = (char *)n - (char *)sap_msg;
 187                 (*output)(sapsock, flags, dst, size);
 188                 TRACE_SAP_OUTPUT(ifp, dst, size);
 189         }
 190 }
 191