input.c revision 1.16
1 /* $NetBSD: input.c,v 1.16 1995/07/13 23:20:10 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 1.16 1995/07/13 23:20:10 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 (n->rip_family < af_max && 157 afswitch[n->rip_family].af_hash) { 158 if (!(*afswitch[n->rip_family].af_get)( 159 DESTINATION, n, &dst)) 160 return; 161 rt = rtlookup(&dst); 162 } 163 else 164 rt = 0; 165 #define min(a, b) (a < b ? a : b) 166 n->rip_metric = rt == 0 ? HOPCNT_INFINITY : 167 min(rt->rt_metric + 1, HOPCNT_INFINITY); 168 n->rip_metric = htonl(n->rip_metric); 169 } 170 rip->rip_cmd = RIPCMD_RESPONSE; 171 memcpy(packet, rip, size); 172 (*afp->af_output)(s, 0, from, size); 173 return; 174 175 case RIPCMD_TRACEON: 176 case RIPCMD_TRACEOFF: 177 /* verify message came from a privileged port */ 178 if ((*afp->af_portcheck)(from) == 0) 179 return; 180 181 if ((ifp = rip_verify(from)) == NULL) 182 return; 183 184 ((char *)rip)[size] = '\0'; 185 if (rip->rip_cmd == RIPCMD_TRACEON) 186 traceon(rip->rip_tracefile); 187 else 188 traceoff(); 189 return; 190 191 case RIPCMD_RESPONSE: 192 /* verify message came from a router */ 193 if ((*afp->af_portmatch)(from) == 0) 194 return; 195 (*afp->af_canon)(from); 196 /* are we talking to ourselves? */ 197 ifp = if_ifwithaddr(from); 198 if (ifp) { 199 if (ifp->int_flags & IFF_PASSIVE) { 200 syslog(LOG_ERR, 201 "bogus input (from passive interface, %s)", 202 (*afswitch[from->sa_family].af_format)(from, 203 buf1, sizeof(buf1))); 204 return; 205 } 206 rt = rtfind(from); 207 if (rt == 0 || (((rt->rt_state & RTS_INTERFACE) == 0) && 208 rt->rt_metric >= ifp->int_metric)) 209 addrouteforif(ifp); 210 else 211 rt->rt_timer = 0; 212 return; 213 } 214 /* 215 * Update timer for interface on which the packet arrived. 216 * If from other end of a point-to-point link that isn't 217 * in the routing tables, (re-)add the route. 218 */ 219 if ((rt = rtfind(from)) && 220 (rt->rt_state & (RTS_INTERFACE | RTS_REMOTE))) 221 rt->rt_timer = 0; 222 else if ((ifp = if_ifwithdstaddr(from)) && 223 (rt == 0 || rt->rt_metric >= ifp->int_metric)) 224 addrouteforif(ifp); 225 226 if ((ifp = rip_verify(from)) == NULL) 227 return; 228 229 size -= 4 * sizeof (char); 230 n = rip->rip_nets; 231 for (; size > 0; size -= sizeof (struct netinfo), n++) { 232 if (size < sizeof (struct netinfo)) 233 break; 234 n->rip_metric = ntohl(n->rip_metric); 235 n->rip_family = ntohs(n->rip_family); 236 if (!(*afswitch[n->rip_family].af_get)(DESTINATION, n, 237 &dst)) 238 continue; 239 if (!(*afswitch[n->rip_family].af_get)(NETMASK, 240 n, &netmask)) 241 memset(&netmask, 0, sizeof(netmask)); 242 if (!(*afswitch[n->rip_family].af_get)(GATEWAY, 243 n, &gateway)) 244 memcpy(&gateway, from, sizeof(gateway)); 245 if (dst.sa_family >= af_max || 246 (afp = &afswitch[dst.sa_family])->af_hash == NULL) { 247 syslog(LOG_INFO, 248 "route in unsupported address family (%d), from %s (af %d)\n", 249 dst.sa_family, 250 (*afswitch[from->sa_family].af_format)(from, 251 buf1, sizeof(buf1)), 252 from->sa_family); 253 continue; 254 } 255 if (((*afp->af_checkhost)(&dst)) == 0) { 256 syslog(LOG_DEBUG, 257 "bad host %s in route from %s (af %d)\n", 258 (*afswitch[dst.sa_family].af_format)( 259 &dst, buf1, sizeof(buf1)), 260 (*afswitch[from->sa_family].af_format)(from, 261 buf2, sizeof(buf2)), 262 from->sa_family); 263 continue; 264 } 265 if (n->rip_metric == 0 || 266 (unsigned) n->rip_metric > HOPCNT_INFINITY) { 267 if (memcmp(from, &badfrom, 268 sizeof(badfrom)) != 0) { 269 syslog(LOG_ERR, 270 "bad metric (%d) from %s\n", 271 n->rip_metric, 272 (*afswitch[from->sa_family].af_format)(from, 273 buf1, sizeof(buf1))); 274 badfrom = *from; 275 } 276 continue; 277 } 278 /* 279 * Adjust metric according to incoming interface. 280 */ 281 if ((unsigned) n->rip_metric < HOPCNT_INFINITY) 282 n->rip_metric += ifp->int_metric; 283 if ((unsigned) n->rip_metric > HOPCNT_INFINITY) 284 n->rip_metric = HOPCNT_INFINITY; 285 rt = rtlookup(&dst); 286 if (rt == 0 || 287 (rt->rt_state & (RTS_INTERNAL|RTS_INTERFACE)) == 288 (RTS_INTERNAL|RTS_INTERFACE)) { 289 /* 290 * If we're hearing a logical network route 291 * back from a peer to which we sent it, 292 * ignore it. 293 */ 294 if (rt && rt->rt_state & RTS_SUBNET && 295 (*afp->af_sendroute)(rt, from)) 296 continue; 297 if ((unsigned)n->rip_metric < HOPCNT_INFINITY) { 298 /* 299 * Look for an equivalent route that 300 * includes this one before adding 301 * this route. 302 */ 303 rt = rtfind(&dst); 304 if (rt && equal(&gateway, &rt->rt_router)) 305 continue; 306 rtadd(&dst, &gateway, &netmask, 307 n->rip_metric, 0); 308 changes++; 309 } 310 continue; 311 } 312 313 /* 314 * Update if from gateway and different, 315 * shorter, or equivalent but old route 316 * is getting stale. 317 */ 318 if (equal(&gateway, &rt->rt_router)) { 319 if (n->rip_metric != rt->rt_metric) { 320 rtchange(rt, &gateway, 321 &netmask, n->rip_metric); 322 changes++; 323 rt->rt_timer = 0; 324 if (rt->rt_metric >= HOPCNT_INFINITY) 325 rt->rt_timer = 326 GARBAGE_TIME - EXPIRE_TIME; 327 } else if (rt->rt_metric < HOPCNT_INFINITY) 328 rt->rt_timer = 0; 329 } else if ((unsigned) n->rip_metric < rt->rt_metric || 330 (rt->rt_metric == n->rip_metric && 331 rt->rt_timer > (EXPIRE_TIME/2) && 332 (unsigned) n->rip_metric < HOPCNT_INFINITY)) { 333 rtchange(rt, &gateway, &netmask, n->rip_metric); 334 changes++; 335 rt->rt_timer = 0; 336 } 337 } 338 break; 339 } 340 341 /* 342 * If changes have occurred, and if we have not sent a broadcast 343 * recently, send a dynamic update. This update is sent only 344 * on interfaces other than the one on which we received notice 345 * of the change. If we are within MIN_WAITTIME of a full update, 346 * don't bother sending; if we just sent a dynamic update 347 * and set a timer (nextbcast), delay until that time. 348 * If we just sent a full update, delay the dynamic update. 349 * Set a timer for a randomized value to suppress additional 350 * dynamic updates until it expires; if we delayed sending 351 * the current changes, set needupdate. 352 */ 353 if (changes && supplier && 354 now.tv_sec - lastfullupdate.tv_sec < SUPPLY_INTERVAL-MAX_WAITTIME) { 355 u_long delay; 356 357 if (now.tv_sec - lastbcast.tv_sec >= MIN_WAITTIME && 358 timercmp(&nextbcast, &now, <)) { 359 if (traceactions) 360 fprintf(ftrace, "send dynamic update\n"); 361 toall(supply, RTS_CHANGED, ifp); 362 lastbcast = now; 363 needupdate = 0; 364 nextbcast.tv_sec = 0; 365 } else { 366 needupdate++; 367 if (traceactions) 368 fprintf(ftrace, "delay dynamic update\n"); 369 } 370 #define RANDOMDELAY() (MIN_WAITTIME * 1000000 + \ 371 (u_long)random() % ((MAX_WAITTIME - MIN_WAITTIME) * 1000000)) 372 373 if (nextbcast.tv_sec == 0) { 374 delay = RANDOMDELAY(); 375 if (traceactions) 376 fprintf(ftrace, 377 "inhibit dynamic update for %d usec\n", 378 delay); 379 nextbcast.tv_sec = delay / 1000000; 380 nextbcast.tv_usec = delay % 1000000; 381 timeradd(&nextbcast, &now, &nextbcast); 382 /* 383 * If the next possibly dynamic update 384 * is within MIN_WAITTIME of the next full update, 385 * force the delay past the full update, 386 * or we might send a dynamic update just before 387 * the full update. 388 */ 389 if (nextbcast.tv_sec > lastfullupdate.tv_sec + 390 SUPPLY_INTERVAL - MIN_WAITTIME) 391 nextbcast.tv_sec = lastfullupdate.tv_sec + 392 SUPPLY_INTERVAL + 1; 393 } 394 } 395 } 396
Indexes created Wed Oct 15 16:09:53 GMT 2025