sap_input.c revision 27244
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 * $Id: sap_input.c,v 1.4 1997/02/22 16:00:59 peter Exp $ 32 */ 33 34/* 35 * IPX Routing Table Management Daemon 36 */ 37#include "defs.h" 38 39 40/* 41 * Process a newly received packet. 42 */ 43void 44sap_input(from, size) 45 struct sockaddr *from; 46 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 sap = sap_nearestserver(n->ServType, ifp); 82 if (sap == NULL) 83 return; 84 sap_msg->sap_cmd = htons(SAP_RESP_NEAR); 85 *n = sap->sap; 86 n->hops = htons(ntohs(n->hops) + 1); 87 if (ntohs(n->hops) >= HOPCNT_INFINITY) 88 return; 89 90 newsize = sizeof(struct sap_info) + sizeof(struct sap_packet); 91 (*afp->af_output)(sapsock, 0, from, newsize); 92 if (ftrace) { 93 fprintf(ftrace, "sap_nearestserver %X %s returned:\n", 94 ntohs(n->ServType), 95 ifp->int_name); 96 fprintf(ftrace, " service %04X %-20.20s " 97 "addr %s.%04X metric %d\n", 98 ntohs(sap->sap.ServType), 99 sap->sap.ServName, 100 ipxdp_ntoa(&sap->sap.ipx), 101 ntohs(sap->sap.ipx.x_port), 102 ntohs(sap->sap.hops)); 103 } 104 return; 105 106 case SAP_REQ: 107 if (ftrace) 108 fprintf(ftrace, "Received a sap REQ packet.\n"); 109 110 sap_supply(from, 0, ifp, n->ServType, 0); 111 return; 112 113 case SAP_RESP_NEAR: 114 /* XXX We do nothing here, for the moment. 115 * Maybe we should check if the service is in our table? 116 * 117 */ 118 if (ftrace) 119 fprintf(ftrace, "Received a sap RESP_NEAR packet.\n"); 120 121 return; 122 123 case SAP_RESP: 124 if (ftrace) 125 fprintf(ftrace, "Received a sap RESP packet.\n"); 126 127 (*afp->af_canon)(from); 128 129 for (; size > 0; size -= sizeof (struct sap_info), n++) { 130 if (size < sizeof (struct netinfo)) 131 break; 132 /* 133 * The idea here is that if the hop count is more 134 * than INFINITY it is bogus and should be discarded. 135 * If it is equal to INFINITY it is a message to say 136 * that a service went down. If we don't allready 137 * have it in our tables discard it. Otherwise 138 * update our table and set the timer to EXPIRE_TIME 139 * so that it is removed next time we go through the 140 * tables. 141 */ 142 if (ntohs(n->hops) > HOPCNT_INFINITY) 143 continue; 144 sap = sap_lookup(n->ServType, n->ServName); 145 if (sap == 0) { 146 if (ntohs(n->hops) == HOPCNT_INFINITY) 147 continue; 148 sap_add(n, from); 149 sapchanged = 1; 150 continue; 151 } 152 153 /* 154 * A clone is a different route to the same service 155 * with exactly the same cost (metric). 156 * They must all be recorded because those interfaces 157 * must be handled in the same way as the first route 158 * to that service. ie When using the split horizon 159 * algorithm we must look at these interfaces also. 160 * 161 * Update if from gateway and different, 162 * from anywhere and less hops or 163 * getting stale and equivalent. 164 */ 165 if (((ifp != sap->ifp) || 166 !equal(&sap->source, from)) && 167 (n->hops == sap->sap.hops) && 168 (ntohs(n->hops) != HOPCNT_INFINITY)) { 169 register struct sap_entry *tsap = sap->clone; 170 171 while (tsap) { 172 if ((ifp == tsap->ifp) && 173 equal(&tsap->source, from)) { 174 tsap->timer = 0; 175 break; 176 } 177 tsap = tsap->clone; 178 } 179 if (tsap == NULL) { 180 sap_add_clone(sap, n, from); 181 } 182 continue; 183 } 184 if ((ifp == sap->ifp) && 185 equal(&sap->source, from) && 186 (ntohs(n->hops) == ntohs(sap->sap.hops))) 187 sap->timer = 0; 188 else if (((ifp == sap->ifp) && 189 equal(&sap->source, from) && 190 (n->hops != sap->sap.hops)) || 191 (ntohs(n->hops) < ntohs(sap->sap.hops)) || 192 (sap->timer > (EXPIRE_TIME*2/3) && 193 ntohs(sap->sap.hops) == ntohs(n->hops) && 194 ntohs(n->hops) != HOPCNT_INFINITY)) { 195 sap_change(sap, n, from); 196 sapchanged = 1; 197 } 198 } 199 if (sapchanged) { 200 register struct sap_entry *sap; 201 register struct sap_hash *sh; 202 sap_supply_toall(1); 203 204 for (sh = sap_head; sh < &sap_head[SAPHASHSIZ]; sh++) 205 for (sap = sh->forw; 206 sap != (struct sap_entry *)sh; 207 sap = sap->forw) 208 sap->state &= ~RTS_CHANGED; 209 } 210 return; 211 } 212} 213