input.c revision 1.15
1 /* $NetBSD: input.c,v 1.15 1995/06/20 22:27:50 christos Exp $ */ 2 3 /* 4 * Copyright (c) 1983, 1988, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #ifndef lint 37 #if 0 38 static char sccsid[] = "@(#)input.c 8.1 (Berkeley) 6/5/93"; 39 #else 40 static char rcsid[] = "$NetBSD: input.c,v 1.15 1995/06/20 22:27:50 christos Exp $"; 41 #endif 42 #endif /* not lint */ 43 44 /* 45 * Routing Table Management Daemon 46 */ 47 #include "defs.h" 48 #include <syslog.h> 49 50 51 /* 52 * "Authenticate" router from which message originated. 53 * We accept routing packets from routers directly connected 54 * via broadcast or point-to-point networks, 55 * and from those listed in /etc/gateways. 56 */ 57 static struct interface * 58 rip_verify(from) 59 struct sockaddr *from; 60 { 61 struct interface *ifp; 62 char buf[256]; 63 64 if ((ifp = if_iflookup(from)) == 0) { 65 syslog(LOG_ERR, "trace command from unknown router, %s", 66 (*afswitch[from->sa_family].af_format)(from, buf, 67 sizeof(buf))); 68 return NULL; 69 } 70 71 if ((ifp->int_flags & 72 (IFF_BROADCAST|IFF_POINTOPOINT|IFF_REMOTE)) == 0) { 73 syslog(LOG_ERR, 74 "trace command from router %s, with bad flags %x", 75 (*afswitch[from->sa_family].af_format)(from, buf, 76 sizeof(buf)), 77 ifp->int_flags); 78 return NULL; 79 } 80 81 if ((ifp->int_flags & IFF_PASSIVE) != 0) { 82 syslog(LOG_ERR, 83 "trace command from %s on an active interface", 84 (*afswitch[from->sa_family].af_format)(from, buf, 85 sizeof(buf))); 86 return NULL; 87 } 88 89 return ifp; 90 } 91 92 93 /* 94 * Process a newly received packet. 95 */ 96 void 97 rip_input(from, rip, size) 98 struct sockaddr *from; 99 register struct rip *rip; 100 int size; 101 { 102 register struct rt_entry *rt; 103 register struct netinfo *n; 104 register struct interface *ifp; 105 struct sockaddr dst, gateway, netmask; 106 int count, changes = 0; 107 register struct afswitch *afp; 108 static struct sockaddr badfrom; 109 char buf1[256], buf2[256]; 110 111 ifp = 0; 112 TRACE_INPUT(ifp, from, (char *)rip, size); 113 if (from->sa_family >= af_max || 114 (afp = &afswitch[from->sa_family])->af_hash == NULL) { 115 syslog(LOG_INFO, 116 "\"from\" address in unsupported address family (%d), cmd %d\n", 117 from->sa_family, rip->rip_cmd); 118 return; 119 } 120 if (rip->rip_vers == 0) { 121 syslog(LOG_ERR, 122 "RIP version 0 packet received from %s! (cmd %d)", 123 (*afswitch[from->sa_family].af_format)(from, buf1, 124 sizeof(buf1)), 125 rip->rip_cmd); 126 return; 127 } 128 129 switch (rip->rip_cmd) { 130 131 case RIPCMD_REQUEST: 132 n = rip->rip_nets; 133 count = size - ((char *)n - (char *)rip); 134 if (count < sizeof (struct netinfo)) 135 return; 136 for (; count > 0; n++) { 137 if (count < sizeof (struct netinfo)) 138 break; 139 count -= sizeof (struct netinfo); 140 141 n->rip_metric = ntohl(n->rip_metric); 142 n->rip_family = ntohs(n->rip_family); 143 /* 144 * A single entry with sa_family == AF_UNSPEC and 145 * metric ``infinity'' means ``all routes''. 146 * We respond to routers only if we are acting 147 * as a supplier, or to anyone other than a router 148 * (eg, query). 149 */ 150 if (n->rip_family == AF_UNSPEC && 151 n->rip_metric == HOPCNT_INFINITY && count == 0) { 152 if (supplier || (*afp->af_portmatch)(from) == 0) 153 supply(from, 0, 0, 0); 154 return; 155 } 156 if (dst.sa_family < af_max && 157 afswitch[dst.sa_family].af_hash) { 158 (*afswitch[n->rip_family].af_get)(DESTINATION, 159 n, &dst); 160 rt = rtlookup(&dst); 161 } 162 else 163 rt = 0; 164 #define min(a, b) (a < b ? a : b) 165 n->rip_metric = rt == 0 ? HOPCNT_INFINITY : 166 min(rt->rt_metric + 1, HOPCNT_INFINITY); 167 n->rip_metric = htonl(n->rip_metric); 168 } 169 rip->rip_cmd = RIPCMD_RESPONSE; 170 memcpy(packet, rip, size); 171 (*afp->af_output)(s, 0, from, size); 172 return; 173 174 case RIPCMD_TRACEON: 175 case RIPCMD_TRACEOFF: 176 /* verify message came from a privileged port */ 177 if ((*afp->af_portcheck)(from) == 0) 178 return; 179 180 if ((ifp = rip_verify(from)) == NULL) 181 return; 182 183 ((char *)rip)[size] = '\0'; 184 if (rip->rip_cmd == RIPCMD_TRACEON) 185 traceon(rip->rip_tracefile); 186 else 187 traceoff(); 188 return; 189 190 case RIPCMD_RESPONSE: 191 /* verify message came from a router */ 192 if ((*afp->af_portmatch)(from) == 0) 193 return; 194 (*afp->af_canon)(from); 195 /* are we talking to ourselves? */ 196 ifp = if_ifwithaddr(from); 197 if (ifp) { 198 if (ifp->int_flags & IFF_PASSIVE) { 199 syslog(LOG_ERR, 200 "bogus input (from passive interface, %s)", 201 (*afswitch[from->sa_family].af_format)(from, 202 buf1, sizeof(buf1))); 203 return; 204 } 205 rt = rtfind(from); 206 if (rt == 0 || (((rt->rt_state & RTS_INTERFACE) == 0) && 207 rt->rt_metric >= ifp->int_metric)) 208 addrouteforif(ifp); 209 else 210 rt->rt_timer = 0; 211 return; 212 } 213 /* 214 * Update timer for interface on which the packet arrived. 215 * If from other end of a point-to-point link that isn't 216 * in the routing tables, (re-)add the route. 217 */ 218 if ((rt = rtfind(from)) && 219 (rt->rt_state & (RTS_INTERFACE | RTS_REMOTE))) 220 rt->rt_timer = 0; 221 else if ((ifp = if_ifwithdstaddr(from)) && 222 (rt == 0 || rt->rt_metric >= ifp->int_metric)) 223 addrouteforif(ifp); 224 225 if ((ifp = rip_verify(from)) == NULL) 226 return; 227 228 size -= 4 * sizeof (char); 229 n = rip->rip_nets; 230 for (; size > 0; size -= sizeof (struct netinfo), n++) { 231 if (size < sizeof (struct netinfo)) 232 break; 233 n->rip_metric = ntohl(n->rip_metric); 234 n->rip_family = ntohs(n->rip_family); 235 if (!(*afswitch[n->rip_family].af_get)(DESTINATION, n, 236 &dst)) 237 continue; 238 if (!(*afswitch[n->rip_family].af_get)(NETMASK, 239 n, &netmask)) 240 memset(&netmask, 0, sizeof(netmask)); 241 if (!(*afswitch[n->rip_family].af_get)(GATEWAY, 242 n, &gateway)) 243 memcpy(&gateway, from, sizeof(gateway)); 244 if (dst.sa_family >= af_max || 245 (afp = &afswitch[dst.sa_family])->af_hash == NULL) { 246 syslog(LOG_INFO, 247 "route in unsupported address family (%d), from %s (af %d)\n", 248 dst.sa_family, 249 (*afswitch[from->sa_family].af_format)(from, 250 buf1, sizeof(buf1)), 251 from->sa_family); 252 continue; 253 } 254 if (((*afp->af_checkhost)(&dst)) == 0) { 255 syslog(LOG_DEBUG, 256 "bad host %s in route from %s (af %d)\n", 257 (*afswitch[dst.sa_family].af_format)( 258 &dst, buf1, sizeof(buf1)), 259 (*afswitch[from->sa_family].af_format)(from, 260 buf2, sizeof(buf2)), 261 from->sa_family); 262 continue; 263 } 264 if (n->rip_metric == 0 || 265 (unsigned) n->rip_metric > HOPCNT_INFINITY) { 266 if (memcmp(from, &badfrom, 267 sizeof(badfrom)) != 0) { 268 syslog(LOG_ERR, 269 "bad metric (%d) from %s\n", 270 n->rip_metric, 271 (*afswitch[from->sa_family].af_format)(from, 272 buf1, sizeof(buf1))); 273 badfrom = *from; 274 } 275 continue; 276 } 277 /* 278 * Adjust metric according to incoming interface. 279 */ 280 if ((unsigned) n->rip_metric < HOPCNT_INFINITY) 281 n->rip_metric += ifp->int_metric; 282 if ((unsigned) n->rip_metric > HOPCNT_INFINITY) 283 n->rip_metric = HOPCNT_INFINITY; 284 rt = rtlookup(&dst); 285 if (rt == 0 || 286 (rt->rt_state & (RTS_INTERNAL|RTS_INTERFACE)) == 287 (RTS_INTERNAL|RTS_INTERFACE)) { 288 /* 289 * If we're hearing a logical network route 290 * back from a peer to which we sent it, 291 * ignore it. 292 */ 293 if (rt && rt->rt_state & RTS_SUBNET && 294 (*afp->af_sendroute)(rt, from)) 295 continue; 296 if ((unsigned)n->rip_metric < HOPCNT_INFINITY) { 297 /* 298 * Look for an equivalent route that 299 * includes this one before adding 300 * this route. 301 */ 302 rt = rtfind(&dst); 303 if (rt && equal(&gateway, &rt->rt_router)) 304 continue; 305 rtadd(&dst, &gateway, &netmask, 306 n->rip_metric, 0); 307 changes++; 308 } 309 continue; 310 } 311 312 /* 313 * Update if from gateway and different, 314 * shorter, or equivalent but old route 315 * is getting stale. 316 */ 317 if (equal(&gateway, &rt->rt_router)) { 318 if (n->rip_metric != rt->rt_metric) { 319 rtchange(rt, &gateway, 320 &netmask, n->rip_metric); 321 changes++; 322 rt->rt_timer = 0; 323 if (rt->rt_metric >= HOPCNT_INFINITY) 324 rt->rt_timer = 325 GARBAGE_TIME - EXPIRE_TIME; 326 } else if (rt->rt_metric < HOPCNT_INFINITY) 327 rt->rt_timer = 0; 328 } else if ((unsigned) n->rip_metric < rt->rt_metric || 329 (rt->rt_metric == n->rip_metric && 330 rt->rt_timer > (EXPIRE_TIME/2) && 331 (unsigned) n->rip_metric < HOPCNT_INFINITY)) { 332 rtchange(rt, &gateway, &netmask, n->rip_metric); 333 changes++; 334 rt->rt_timer = 0; 335 } 336 } 337 break; 338 } 339 340 /* 341 * If changes have occurred, and if we have not sent a broadcast 342 * recently, send a dynamic update. This update is sent only 343 * on interfaces other than the one on which we received notice 344 * of the change. If we are within MIN_WAITTIME of a full update, 345 * don't bother sending; if we just sent a dynamic update 346 * and set a timer (nextbcast), delay until that time. 347 * If we just sent a full update, delay the dynamic update. 348 * Set a timer for a randomized value to suppress additional 349 * dynamic updates until it expires; if we delayed sending 350 * the current changes, set needupdate. 351 */ 352 if (changes && supplier && 353 now.tv_sec - lastfullupdate.tv_sec < SUPPLY_INTERVAL-MAX_WAITTIME) { 354 u_long delay; 355 356 if (now.tv_sec - lastbcast.tv_sec >= MIN_WAITTIME && 357 timercmp(&nextbcast, &now, <)) { 358 if (traceactions) 359 fprintf(ftrace, "send dynamic update\n"); 360 toall(supply, RTS_CHANGED, ifp); 361 lastbcast = now; 362 needupdate = 0; 363 nextbcast.tv_sec = 0; 364 } else { 365 needupdate++; 366 if (traceactions) 367 fprintf(ftrace, "delay dynamic update\n"); 368 } 369 #define RANDOMDELAY() (MIN_WAITTIME * 1000000 + \ 370 (u_long)random() % ((MAX_WAITTIME - MIN_WAITTIME) * 1000000)) 371 372 if (nextbcast.tv_sec == 0) { 373 delay = RANDOMDELAY(); 374 if (traceactions) 375 fprintf(ftrace, 376 "inhibit dynamic update for %d usec\n", 377 delay); 378 nextbcast.tv_sec = delay / 1000000; 379 nextbcast.tv_usec = delay % 1000000; 380 timeradd(&nextbcast, &now, &nextbcast); 381 /* 382 * If the next possibly dynamic update 383 * is within MIN_WAITTIME of the next full update, 384 * force the delay past the full update, 385 * or we might send a dynamic update just before 386 * the full update. 387 */ 388 if (nextbcast.tv_sec > lastfullupdate.tv_sec + 389 SUPPLY_INTERVAL - MIN_WAITTIME) 390 nextbcast.tv_sec = lastfullupdate.tv_sec + 391 SUPPLY_INTERVAL + 1; 392 } 393 } 394 } 395
Indexes created Wed Sep 24 22:09:59 GMT 2025