input.c revision 1.8
1 /* 2 * Copyright (c) 1983, 1988, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #ifndef lint 35 /*static char sccsid[] = "from: @(#)input.c 8.1 (Berkeley) 6/5/93";*/ 36 static char *rcsid = "$Id: input.c,v 1.8 1994/12/18 05:43:54 cgd Exp $"; 37 #endif /* not lint */ 38 39 /* 40 * Routing Table Management Daemon 41 */ 42 #include "defs.h" 43 #include <sys/syslog.h> 44 45 /* 46 * Process a newly received packet. 47 */ 48 void 49 rip_input(from, rip, size) 50 struct sockaddr *from; 51 register struct rip *rip; 52 int size; 53 { 54 register struct rt_entry *rt; 55 register struct netinfo *n; 56 register struct interface *ifp; 57 struct interface *if_ifwithdstaddr(); 58 int count, changes = 0; 59 register struct afswitch *afp; 60 static struct sockaddr badfrom, badfrom2; 61 62 ifp = 0; 63 TRACE_INPUT(ifp, (struct sockaddr_in *)from, (char *)rip, size); 64 if (from->sa_family >= af_max || 65 (afp = &afswitch[from->sa_family])->af_hash == (int (*)())0) { 66 syslog(LOG_INFO, 67 "\"from\" address in unsupported address family (%d), cmd %d\n", 68 from->sa_family, rip->rip_cmd); 69 return; 70 } 71 if (rip->rip_vers == 0) { 72 syslog(LOG_ERR, 73 "RIP version 0 packet received from %s! (cmd %d)", 74 (*afswitch[from->sa_family].af_format)(from), rip->rip_cmd); 75 return; 76 } 77 switch (rip->rip_cmd) { 78 79 case RIPCMD_REQUEST: 80 n = rip->rip_nets; 81 count = size - ((char *)n - (char *)rip); 82 if (count < sizeof (struct netinfo)) 83 return; 84 for (; count > 0; n++) { 85 if (count < sizeof (struct netinfo)) 86 break; 87 count -= sizeof (struct netinfo); 88 89 #if BSD < 198810 90 if (sizeof(n->rip_dst.sa_family) > 1) /* XXX */ 91 n->rip_dst.sa_family = ntohs(n->rip_dst.sa_family); 92 #else 93 #define osa(x) ((struct osockaddr *)(&(x))) 94 n->rip_dst.sa_family = 95 ntohs(osa(n->rip_dst)->sa_family); 96 n->rip_dst.sa_len = sizeof(n->rip_dst); 97 #endif 98 n->rip_metric = ntohl(n->rip_metric); 99 /* 100 * A single entry with sa_family == AF_UNSPEC and 101 * metric ``infinity'' means ``all routes''. 102 * We respond to routers only if we are acting 103 * as a supplier, or to anyone other than a router 104 * (eg, query). 105 */ 106 if (n->rip_dst.sa_family == AF_UNSPEC && 107 n->rip_metric == HOPCNT_INFINITY && count == 0) { 108 if (supplier || (*afp->af_portmatch)(from) == 0) 109 supply(from, 0, 0, 0); 110 return; 111 } 112 if (n->rip_dst.sa_family < af_max && 113 afswitch[n->rip_dst.sa_family].af_hash) 114 rt = rtlookup(&n->rip_dst); 115 else 116 rt = 0; 117 #define min(a, b) (a < b ? a : b) 118 n->rip_metric = rt == 0 ? HOPCNT_INFINITY : 119 min(rt->rt_metric + 1, HOPCNT_INFINITY); 120 #if BSD < 198810 121 if (sizeof(n->rip_dst.sa_family) > 1) /* XXX */ 122 n->rip_dst.sa_family = htons(n->rip_dst.sa_family); 123 #else 124 osa(n->rip_dst)->sa_family = 125 htons(n->rip_dst.sa_family); 126 #endif 127 n->rip_metric = htonl(n->rip_metric); 128 } 129 rip->rip_cmd = RIPCMD_RESPONSE; 130 memcpy(packet, rip, size); 131 (*afp->af_output)(s, 0, from, size); 132 return; 133 134 case RIPCMD_TRACEON: 135 case RIPCMD_TRACEOFF: 136 /* verify message came from a privileged port */ 137 if ((*afp->af_portcheck)(from) == 0) 138 return; 139 if ((ifp = if_iflookup(from)) == 0 || (ifp->int_flags & 140 (IFF_BROADCAST | IFF_POINTOPOINT | IFF_REMOTE)) == 0 || 141 ifp->int_flags & IFF_PASSIVE) { 142 syslog(LOG_ERR, "trace command from unknown router, %s", 143 (*afswitch[from->sa_family].af_format)(from)); 144 return; 145 } 146 ((char *)rip)[size] = '\0'; 147 if (rip->rip_cmd == RIPCMD_TRACEON) 148 traceon(rip->rip_tracefile); 149 else 150 traceoff(); 151 return; 152 153 case RIPCMD_RESPONSE: 154 /* verify message came from a router */ 155 if ((*afp->af_portmatch)(from) == 0) 156 return; 157 (*afp->af_canon)(from); 158 /* are we talking to ourselves? */ 159 ifp = if_ifwithaddr(from); 160 if (ifp) { 161 if (ifp->int_flags & IFF_PASSIVE) { 162 syslog(LOG_ERR, 163 "bogus input (from passive interface, %s)", 164 (*afswitch[from->sa_family].af_format)(from)); 165 return; 166 } 167 rt = rtfind(from); 168 if (rt == 0 || ((rt->rt_state & RTS_INTERFACE) == 0) && 169 rt->rt_metric >= ifp->int_metric) 170 addrouteforif(ifp); 171 else 172 rt->rt_timer = 0; 173 return; 174 } 175 /* 176 * Update timer for interface on which the packet arrived. 177 * If from other end of a point-to-point link that isn't 178 * in the routing tables, (re-)add the route. 179 */ 180 if ((rt = rtfind(from)) && 181 (rt->rt_state & (RTS_INTERFACE | RTS_REMOTE))) 182 rt->rt_timer = 0; 183 else if ((ifp = if_ifwithdstaddr(from)) && 184 (rt == 0 || rt->rt_metric >= ifp->int_metric)) 185 addrouteforif(ifp); 186 /* 187 * "Authenticate" router from which message originated. 188 * We accept routing packets from routers directly connected 189 * via broadcast or point-to-point networks, 190 * and from those listed in /etc/gateways. 191 */ 192 if ((ifp = if_iflookup(from)) == 0 || (ifp->int_flags & 193 (IFF_BROADCAST | IFF_POINTOPOINT | IFF_REMOTE)) == 0 || 194 ifp->int_flags & IFF_PASSIVE) { 195 if (memcmp(from, &badfrom, sizeof(badfrom)) != 0) { 196 syslog(LOG_ERR, 197 "packet from unknown router, %s", 198 (*afswitch[from->sa_family].af_format)(from)); 199 badfrom = *from; 200 } 201 return; 202 } 203 size -= 4 * sizeof (char); 204 n = rip->rip_nets; 205 for (; size > 0; size -= sizeof (struct netinfo), n++) { 206 if (size < sizeof (struct netinfo)) 207 break; 208 #if BSD < 198810 209 if (sizeof(n->rip_dst.sa_family) > 1) /* XXX */ 210 n->rip_dst.sa_family = 211 ntohs(n->rip_dst.sa_family); 212 #else 213 n->rip_dst.sa_family = 214 ntohs(osa(n->rip_dst)->sa_family); 215 n->rip_dst.sa_len = sizeof(n->rip_dst); 216 #endif 217 n->rip_metric = ntohl(n->rip_metric); 218 if (n->rip_dst.sa_family >= af_max || 219 (afp = &afswitch[n->rip_dst.sa_family])->af_hash == 220 (int (*)())0) { 221 syslog(LOG_INFO, 222 "route in unsupported address family (%d), from %s (af %d)\n", 223 n->rip_dst.sa_family, 224 (*afswitch[from->sa_family].af_format)(from), 225 from->sa_family); 226 continue; 227 } 228 if (((*afp->af_checkhost)(&n->rip_dst)) == 0) { 229 syslog(LOG_DEBUG, 230 "bad host in route from %s (af %d)\n", 231 (*afswitch[from->sa_family].af_format)(from), 232 from->sa_family); 233 continue; 234 } 235 if (n->rip_metric == 0 || 236 (unsigned) n->rip_metric > HOPCNT_INFINITY) { 237 if (memcmp(from, &badfrom2, 238 sizeof(badfrom2)) != 0) { 239 syslog(LOG_ERR, 240 "bad metric (%d) from %s\n", 241 n->rip_metric, 242 (*afswitch[from->sa_family].af_format)(from)); 243 badfrom2 = *from; 244 } 245 continue; 246 } 247 /* 248 * Adjust metric according to incoming interface. 249 */ 250 if ((unsigned) n->rip_metric < HOPCNT_INFINITY) 251 n->rip_metric += ifp->int_metric; 252 if ((unsigned) n->rip_metric > HOPCNT_INFINITY) 253 n->rip_metric = HOPCNT_INFINITY; 254 rt = rtlookup(&n->rip_dst); 255 if (rt == 0 || 256 (rt->rt_state & (RTS_INTERNAL|RTS_INTERFACE)) == 257 (RTS_INTERNAL|RTS_INTERFACE)) { 258 /* 259 * If we're hearing a logical network route 260 * back from a peer to which we sent it, 261 * ignore it. 262 */ 263 if (rt && rt->rt_state & RTS_SUBNET && 264 (*afp->af_sendroute)(rt, from)) 265 continue; 266 if ((unsigned)n->rip_metric < HOPCNT_INFINITY) { 267 /* 268 * Look for an equivalent route that 269 * includes this one before adding 270 * this route. 271 */ 272 rt = rtfind(&n->rip_dst); 273 if (rt && equal(from, &rt->rt_router)) 274 continue; 275 rtadd(&n->rip_dst, from, n->rip_metric, 0); 276 changes++; 277 } 278 continue; 279 } 280 281 /* 282 * Update if from gateway and different, 283 * shorter, or equivalent but old route 284 * is getting stale. 285 */ 286 if (equal(from, &rt->rt_router)) { 287 if (n->rip_metric != rt->rt_metric) { 288 rtchange(rt, from, n->rip_metric); 289 changes++; 290 rt->rt_timer = 0; 291 if (rt->rt_metric >= HOPCNT_INFINITY) 292 rt->rt_timer = 293 GARBAGE_TIME - EXPIRE_TIME; 294 } else if (rt->rt_metric < HOPCNT_INFINITY) 295 rt->rt_timer = 0; 296 } else if ((unsigned) n->rip_metric < rt->rt_metric || 297 (rt->rt_metric == n->rip_metric && 298 rt->rt_timer > (EXPIRE_TIME/2) && 299 (unsigned) n->rip_metric < HOPCNT_INFINITY)) { 300 rtchange(rt, from, n->rip_metric); 301 changes++; 302 rt->rt_timer = 0; 303 } 304 } 305 break; 306 } 307 308 /* 309 * If changes have occurred, and if we have not sent a broadcast 310 * recently, send a dynamic update. This update is sent only 311 * on interfaces other than the one on which we received notice 312 * of the change. If we are within MIN_WAITTIME of a full update, 313 * don't bother sending; if we just sent a dynamic update 314 * and set a timer (nextbcast), delay until that time. 315 * If we just sent a full update, delay the dynamic update. 316 * Set a timer for a randomized value to suppress additional 317 * dynamic updates until it expires; if we delayed sending 318 * the current changes, set needupdate. 319 */ 320 if (changes && supplier && 321 now.tv_sec - lastfullupdate.tv_sec < SUPPLY_INTERVAL-MAX_WAITTIME) { 322 u_long delay; 323 extern long random(); 324 325 if (now.tv_sec - lastbcast.tv_sec >= MIN_WAITTIME && 326 timercmp(&nextbcast, &now, <)) { 327 if (traceactions) 328 fprintf(ftrace, "send dynamic update\n"); 329 toall(supply, RTS_CHANGED, ifp); 330 lastbcast = now; 331 needupdate = 0; 332 nextbcast.tv_sec = 0; 333 } else { 334 needupdate++; 335 if (traceactions) 336 fprintf(ftrace, "delay dynamic update\n"); 337 } 338 #define RANDOMDELAY() (MIN_WAITTIME * 1000000 + \ 339 (u_long)random() % ((MAX_WAITTIME - MIN_WAITTIME) * 1000000)) 340 341 if (nextbcast.tv_sec == 0) { 342 delay = RANDOMDELAY(); 343 if (traceactions) 344 fprintf(ftrace, 345 "inhibit dynamic update for %d usec\n", 346 delay); 347 nextbcast.tv_sec = delay / 1000000; 348 nextbcast.tv_usec = delay % 1000000; 349 timevaladd(&nextbcast, &now); 350 /* 351 * If the next possibly dynamic update 352 * is within MIN_WAITTIME of the next full update, 353 * force the delay past the full update, 354 * or we might send a dynamic update just before 355 * the full update. 356 */ 357 if (nextbcast.tv_sec > lastfullupdate.tv_sec + 358 SUPPLY_INTERVAL - MIN_WAITTIME) 359 nextbcast.tv_sec = lastfullupdate.tv_sec + 360 SUPPLY_INTERVAL + 1; 361 } 362 } 363 } 364
Indexes created Tue Sep 23 21:09:50 GMT 2025