usr.sbin/IPXrouted/sap_input.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_input.c,v 1.7 1999/08/28 01:15:04 peter Exp $
  32  * $DragonFly: src/usr.sbin/IPXrouted/sap_input.c,v 1.3 2004/03/11 09:38:59 hmp Exp $
  33  */
  34
  35 /*
  36  * IPX Routing Table Management Daemon
  37  */
  38 #include "defs.h"
  39
  40 int dognreply = 1;
  41
  42 /*
  43  * Process a newly received packet.
  44  */
  45 void
  46 sap_input(struct sockaddr *from, int size)
  47 {
  48         int newsize;
  49         int sapchanged = 0;
  50         struct sap_entry *sap;
  51         struct sap_info *n;
  52         struct interface *ifp = 0;
  53         struct afswitch *afp;
  54         struct sockaddr_ipx *ipxp;
  55
  56         ifp = if_ifwithnet(from);
  57         ipxp = (struct sockaddr_ipx *)from;
  58         if (ifp == 0) {
  59                 if(ftrace) {
  60                         fprintf(ftrace, "Received bogus packet from %s\n",
  61                                 ipxdp_ntoa(&ipxp->sipx_addr));
  62                 }
  63                 return;
  64         }
  65
  66         if (ftrace)
  67                 dumpsappacket(ftrace, "received", from, (char *)sap_msg , size);
  68
  69         if (from->sa_family >= AF_MAX)
  70                 return;
  71         afp = &afswitch[from->sa_family];
  72
  73         size -= sizeof (u_short)        /* command */;
  74         n = sap_msg->sap;
  75
  76         switch (ntohs(sap_msg->sap_cmd)) {
  77
  78         case SAP_REQ_NEAR:
  79                 if (ftrace)
  80                         fprintf(ftrace, "Received a sap REQ_NEAR packet.\n");
  81                 if (!dognreply)
  82                         return;
  83                 sap = sap_nearestserver(n->ServType, ifp);
  84                 if (sap == NULL)
  85                         return;
  86                 sap_msg->sap_cmd = htons(SAP_RESP_NEAR);
  87                 *n = sap->sap;
  88                 n->hops = htons(ntohs(n->hops) + 1);
  89                 if (ntohs(n->hops) >= HOPCNT_INFINITY)
  90                         return;
  91
  92                 newsize = sizeof(struct sap_info) + sizeof(struct sap_packet);
  93                 (*afp->af_output)(sapsock, 0, from, newsize);
  94                 if (ftrace) {
  95                         fprintf(ftrace, "sap_nearestserver %X %s returned:\n",
  96                                 ntohs(n->ServType),
  97                                 ifp->int_name);
  98                         fprintf(ftrace, "  service %04X %-20.20s "
  99                                         "addr %s.%04X metric %d\n",
 100                                         ntohs(sap->sap.ServType),
 101                                         sap->sap.ServName,
 102                                         ipxdp_ntoa(&sap->sap.ipx),
 103                                         ntohs(sap->sap.ipx.x_port),
 104                                         ntohs(sap->sap.hops));
 105                 }
 106                 return;
 107
 108         case SAP_REQ:
 109                 if (ftrace)
 110                         fprintf(ftrace, "Received a sap REQ packet.\n");
 111
 112                 sap_supply(from, 0, ifp, n->ServType, 0);
 113                 return;
 114
 115         case SAP_RESP_NEAR:
 116                 /* XXX We do nothing here, for the moment.
 117                  * Maybe we should check if the service is in our table?
 118                  *
 119                  */
 120                 if (ftrace)
 121                         fprintf(ftrace, "Received a sap RESP_NEAR packet.\n");
 122
 123                 return;
 124
 125         case SAP_RESP:
 126                 if (ftrace)
 127                         fprintf(ftrace, "Received a sap RESP packet.\n");
 128
 129                 (*afp->af_canon)(from);
 130
 131                 for (; size > 0; size -= sizeof (struct sap_info), n++) {
 132                         if (size < sizeof (struct netinfo))
 133                                 break;
 134                         /*
 135                          * The idea here is that if the hop count is more
 136                          * than INFINITY it is bogus and should be discarded.
 137                          * If it is equal to INFINITY it is a message to say
 138                          * that a service went down. If we don't allready
 139                          * have it in our tables discard it. Otherwise
 140                          * update our table and set the timer to EXPIRE_TIME
 141                          * so that it is removed next time we go through the
 142                          * tables.
 143                          */
 144                         if (ntohs(n->hops) > HOPCNT_INFINITY)
 145                                 continue;
 146                         sap = sap_lookup(n->ServType, n->ServName);
 147                         if (sap == 0) {
 148                                 if (ntohs(n->hops) == HOPCNT_INFINITY)
 149                                         continue;
 150                                 sap_add(n, from);
 151                                 sapchanged = 1;
 152                                 continue;
 153                         }
 154
 155                         /*
 156                          * A clone is a different route to the same service
 157                          * with exactly the same cost (metric).
 158                          * They must all be recorded because those interfaces
 159                          * must be handled in the same way as the first route
 160                          * to that service. ie When using the split horizon
 161                          * algorithm we must look at these interfaces also.
 162                          *
 163                          * Update if from gateway and different,
 164                          * from anywhere and less hops or
 165                          * getting stale and equivalent.
 166                          */
 167                         if (((ifp != sap->ifp) ||
 168                              !equal(&sap->source, from)) &&
 169                             (n->hops == sap->sap.hops) &&
 170                             (ntohs(n->hops) != HOPCNT_INFINITY)) {
 171                                 struct sap_entry *tsap = sap->clone;
 172
 173                                 while (tsap) {
 174                                         if ((ifp == tsap->ifp) &&
 175                                             equal(&tsap->source, from)) {
 176                                                 tsap->timer = 0;
 177                                                 break;
 178                                         }
 179                                         tsap = tsap->clone;
 180                                 }
 181                                 if (tsap == NULL) {
 182                                         sap_add_clone(sap, n, from);
 183                                 }
 184                                 continue;
 185                         }
 186                         if ((ifp == sap->ifp) &&
 187                             equal(&sap->source, from) &&
 188                             (ntohs(n->hops) == ntohs(sap->sap.hops)))
 189                                 sap->timer = 0;
 190                         else if (((ifp == sap->ifp) &&
 191                                   equal(&sap->source, from) &&
 192                                   (n->hops != sap->sap.hops)) ||
 193                                  (ntohs(n->hops) < ntohs(sap->sap.hops)) ||
 194                                  (sap->timer > (EXPIRE_TIME*2/3) &&
 195                                   ntohs(sap->sap.hops) == ntohs(n->hops) &&
 196                                   ntohs(n->hops) != HOPCNT_INFINITY)) {
 197                                 sap_change(sap, n, from);
 198                                 sapchanged = 1;
 199                         }
 200                 }
 201                 if (sapchanged) {
 202                         struct sap_entry *sap;
 203                         struct sap_hash *sh;
 204                         sap_supply_toall(1);
 205
 206                         for (sh = sap_head; sh < &sap_head[SAPHASHSIZ]; sh++)
 207                                 for (sap = sh->forw;
 208                                     sap != (struct sap_entry *)sh;
 209                                     sap = sap->forw)
 210                                         sap->state &= ~RTS_CHANGED;
 211                 }
 212                 return;
 213         }
 214 }