input.c revision 11820
1/* 2 * Copyright (c) 1985, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Copyright (c) 1995 John Hay. All rights reserved. 6 * 7 * This file includes significant work done at Cornell University by 8 * Bill Nesheim. That work included by permission. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * $Id: input.c,v 1.9 1995/10/11 18:57:17 jhay Exp $ 39 */ 40 41#ifndef lint 42static char sccsid[] = "@(#)input.c 8.1 (Berkeley) 6/5/93"; 43#endif /* not lint */ 44 45/* 46 * IPX Routing Table Management Daemon 47 */ 48#include "defs.h" 49 50struct sockaddr * 51ipx_nettosa(net) 52union ipx_net net; 53{ 54 static struct sockaddr_ipx sxn; 55 extern char ether_broadcast_addr[6]; 56 57 bzero(&sxn, sizeof (struct sockaddr_ipx)); 58 sxn.sipx_family = AF_IPX; 59 sxn.sipx_len = sizeof (sxn); 60 sxn.sipx_addr.x_net = net; 61 sxn.sipx_addr.x_host = *(union ipx_host *)ether_broadcast_addr; 62 return( (struct sockaddr *)&sxn); 63 64} 65 66/* 67 * Process a newly received packet. 68 */ 69void 70rip_input(from, size) 71 struct sockaddr *from; 72 int size; 73{ 74 struct rt_entry *rt; 75 struct netinfo *n; 76 struct interface *ifp = 0; 77 int newsize; 78 struct afswitch *afp; 79 struct sockaddr_ipx *ipxp; 80 81 ifp = if_ifwithnet(from); 82 ipxp = (struct sockaddr_ipx *)from; 83 if (ifp == 0) { 84 if(ftrace) { 85 fprintf(ftrace, "Received bogus packet from %s\n", 86 ipxdp_ntoa(&ipxp->sipx_addr)); 87 } 88 return; 89 } 90 91 TRACE_INPUT(ifp, from, size); 92 if (from->sa_family >= AF_MAX) 93 return; 94 afp = &afswitch[from->sa_family]; 95 96 size -= sizeof (u_short) /* command */; 97 n = msg->rip_nets; 98 99 switch (ntohs(msg->rip_cmd)) { 100 101 case RIPCMD_REQUEST: 102 if (ipx_hosteq(satoipx_addr(ifp->int_addr), ipxp->sipx_addr)) 103 return; 104 newsize = 0; 105 while (size > 0) { 106 if (size < sizeof (struct netinfo)) 107 break; 108 size -= sizeof (struct netinfo); 109 110 /* 111 * A single entry with rip_dst == DSTNETS_ALL and 112 * metric ``infinity'' means ``all routes''. 113 * 114 * XXX According to the IPX RIP spec the metric 115 * and tick fields can be anything. So maybe we 116 * should not check the metric??? 117 */ 118 if (ipx_neteqnn(n->rip_dst, ipx_anynet) && 119 ntohs(n->rip_metric) == HOPCNT_INFINITY && 120 size == 0) { 121 supply(from, 0, ifp); 122 return; 123 } 124 /* 125 * request for specific nets 126 */ 127 rt = rtlookup(ipx_nettosa(n->rip_dst)); 128 if (ftrace) { 129 fprintf(ftrace, 130 "specific request for %s", 131 ipxdp_nettoa(n->rip_dst)); 132 fprintf(ftrace, 133 " yields route %x\n", 134 (u_int)rt); 135 } 136 /* 137 * XXX We break out on the first net that isn't 138 * found. The specs is a bit vague here. I'm not 139 * sure what we should do. 140 */ 141 if (rt == 0) 142 return; 143 /* XXX 144 * According to the spec we should not include 145 * information about networks for which the number 146 * of hops is 16. 147 */ 148 if (rt->rt_metric == (HOPCNT_INFINITY-1)) 149 return; 150 n->rip_metric = htons( rt == 0 ? HOPCNT_INFINITY : 151 min(rt->rt_metric+1, HOPCNT_INFINITY)); 152 n->rip_ticks = htons(rt->rt_ticks+1); 153 154 /* 155 * We use split horizon with a twist. If the requested 156 * net is the directly connected net we supply an 157 * answer. This is so that the host can learn about 158 * the routers on its net. 159 */ 160 { 161 register struct rt_entry *trt = rt; 162 163 while (trt) { 164 if ((trt->rt_ifp == ifp) && 165 !ipx_neteqnn(n->rip_dst, 166 satoipx_addr(ifp->int_addr).x_net)) 167 return; 168 trt = trt->rt_clone; 169 } 170 n++; 171 newsize += sizeof (struct netinfo); 172 } 173 } 174 if (newsize > 0) { 175 msg->rip_cmd = htons(RIPCMD_RESPONSE); 176 newsize += sizeof (u_short); 177 /* should check for if with dstaddr(from) first */ 178 (*afp->af_output)(ripsock, 0, from, newsize); 179 TRACE_OUTPUT(ifp, from, newsize); 180 if (ftrace) { 181 /* XXX This should not happen anymore. */ 182 if(ifp == 0) 183 fprintf(ftrace, "--- ifp = 0\n"); 184 else 185 fprintf(ftrace, 186 "request arrived on interface %s\n", 187 ifp->int_name); 188 } 189 } 190 return; 191 192 case RIPCMD_RESPONSE: 193 /* verify message came from a router */ 194 if ((*afp->af_portmatch)(from) == 0) 195 return; 196 (*afp->af_canon)(from); 197 /* are we talking to ourselves? */ 198 if ((ifp = if_ifwithaddr(from)) != 0) { 199 rt = rtfind(from); 200 if (rt == 0 || (rt->rt_state & RTS_INTERFACE) == 0) 201 addrouteforif(ifp); 202 else 203 rt->rt_timer = 0; 204 return; 205 } 206 /* Update timer for interface on which the packet arrived. 207 * If from other end of a point-to-point link that isn't 208 * in the routing tables, (re-)add the route. 209 */ 210 if ((rt = rtfind(from)) && (rt->rt_state & RTS_INTERFACE)) { 211 if(ftrace) fprintf(ftrace, "Got route\n"); 212 rt->rt_timer = 0; 213 } else if ((ifp = if_ifwithdstaddr(from)) != 0) { 214 if(ftrace) fprintf(ftrace, "Got partner\n"); 215 addrouteforif(ifp); 216 } 217 for (; size > 0; size -= sizeof (struct netinfo), n++) { 218 struct sockaddr *sa; 219 if (size < sizeof (struct netinfo)) 220 break; 221 if ((unsigned) ntohs(n->rip_metric) >= HOPCNT_INFINITY) 222 continue; 223 rt = rtfind(sa = ipx_nettosa(n->rip_dst)); 224 if (rt == 0) { 225 rtadd(sa, from, ntohs(n->rip_metric), 226 ntohs(n->rip_ticks), 0); 227 continue; 228 } 229 230 /* 231 * A clone is a different route to the same net 232 * with exactly the same cost (ticks and metric). 233 * They must all be recorded because those interfaces 234 * must be handled in the same way as the first route 235 * to that net. ie When using the split horizon 236 * algorithm we must look at these interfaces also. 237 * 238 * Update if from gateway and different, 239 * from anywhere and less ticks or 240 * if same ticks and shorter, 241 * or getting stale and equivalent. 242 * 243 * XXX I don't think this is quite right. 244 */ 245 if (!equal(from, &rt->rt_router) && 246 ntohs(n->rip_ticks == rt->rt_ticks) && 247 ntohs(n->rip_metric == rt->rt_metric)) { 248 register struct rt_entry *trt = rt->rt_clone; 249 250 while (trt) { 251 if (equal(from, &trt->rt_router)) { 252 trt->rt_timer = 0; 253 break; 254 } 255 } 256 if (trt == NULL) { 257 rtadd_clone(rt, sa, from, 258 ntohs(n->rip_metric), 259 ntohs(n->rip_ticks), 0); 260 } 261 continue; 262 } 263 if ((equal(from, &rt->rt_router) && 264 ((ntohs(n->rip_ticks) != rt->rt_ticks) || 265 (ntohs(n->rip_metric) != rt->rt_metric))) || 266 (ntohs(n->rip_ticks) < rt->rt_ticks) || 267 ((ntohs(n->rip_ticks) == rt->rt_ticks) && 268 (ntohs(n->rip_metric) < rt->rt_metric)) || 269 (rt->rt_timer > (EXPIRE_TIME*2/3) && 270 rt->rt_metric == ntohs(n->rip_metric))) { 271 rtchange(rt, from, ntohs(n->rip_metric), 272 ntohs(n->rip_ticks)); 273 rt->rt_timer = 0; 274 } else if (equal(from, &rt->rt_router) && 275 (ntohs(n->rip_ticks) == rt->rt_ticks) && 276 (ntohs(n->rip_metric) == rt->rt_metric)) { 277 rt->rt_timer = 0; 278 } 279 } 280 return; 281 } 282} 283