input.c revision 1.12
1 /* $NetBSD: input.c,v 1.12 1995/05/24 15:22:55 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 1.12 1995/05/24 15:22:55 christos Exp $"; 41 #endif 42 #endif /* not lint */ 43 44 /* 45 * Routing Table Management Daemon 46 */ 47 #include "defs.h" 48 #include <sys/syslog.h> 49 50 /* 51 * Process a newly received packet. 52 */ 53 void 54 rip_input(from, rip, size) 55 struct sockaddr *from; 56 register struct rip *rip; 57 int size; 58 { 59 register struct rt_entry *rt; 60 register struct netinfo *n; 61 register struct interface *ifp; 62 struct interface *if_ifwithdstaddr(); 63 int count, changes = 0; 64 register struct afswitch *afp; 65 static struct sockaddr badfrom, badfrom2; 66 char buf1[256], buf2[256]; 67 68 ifp = 0; 69 TRACE_INPUT(ifp, from, (char *)rip, size); 70 if (from->sa_family >= af_max || 71 (afp = &afswitch[from->sa_family])->af_hash == (int (*)())0) { 72 syslog(LOG_INFO, 73 "\"from\" address in unsupported address family (%d), cmd %d\n", 74 from->sa_family, rip->rip_cmd); 75 return; 76 } 77 if (rip->rip_vers == 0) { 78 syslog(LOG_ERR, 79 "RIP version 0 packet received from %s! (cmd %d)", 80 (*afswitch[from->sa_family].af_format)(from, buf1, 81 sizeof(buf1)), 82 rip->rip_cmd); 83 return; 84 } 85 switch (rip->rip_cmd) { 86 87 case RIPCMD_REQUEST: 88 n = rip->rip_nets; 89 count = size - ((char *)n - (char *)rip); 90 if (count < sizeof (struct netinfo)) 91 return; 92 for (; count > 0; n++) { 93 if (count < sizeof (struct netinfo)) 94 break; 95 count -= sizeof (struct netinfo); 96 97 #if BSD < 198810 98 if (sizeof(n->rip_dst.sa_family) > 1) /* XXX */ 99 n->rip_dst.sa_family = ntohs(n->rip_dst.sa_family); 100 #else 101 #define osa(x) ((struct osockaddr *)(&(x))) 102 n->rip_dst.sa_family = 103 ntohs(osa(n->rip_dst)->sa_family); 104 n->rip_dst.sa_len = sizeof(n->rip_dst); 105 #endif 106 n->rip_metric = ntohl(n->rip_metric); 107 /* 108 * A single entry with sa_family == AF_UNSPEC and 109 * metric ``infinity'' means ``all routes''. 110 * We respond to routers only if we are acting 111 * as a supplier, or to anyone other than a router 112 * (eg, query). 113 */ 114 if (n->rip_dst.sa_family == AF_UNSPEC && 115 n->rip_metric == HOPCNT_INFINITY && count == 0) { 116 if (supplier || (*afp->af_portmatch)(from) == 0) 117 supply(from, 0, 0, 0); 118 return; 119 } 120 if (n->rip_dst.sa_family < af_max && 121 afswitch[n->rip_dst.sa_family].af_hash) 122 rt = rtlookup(&n->rip_dst); 123 else 124 rt = 0; 125 #define min(a, b) (a < b ? a : b) 126 n->rip_metric = rt == 0 ? HOPCNT_INFINITY : 127 min(rt->rt_metric + 1, HOPCNT_INFINITY); 128 #if BSD < 198810 129 if (sizeof(n->rip_dst.sa_family) > 1) /* XXX */ 130 n->rip_dst.sa_family = htons(n->rip_dst.sa_family); 131 #else 132 osa(n->rip_dst)->sa_family = 133 htons(n->rip_dst.sa_family); 134 #endif 135 n->rip_metric = htonl(n->rip_metric); 136 } 137 rip->rip_cmd = RIPCMD_RESPONSE; 138 memcpy(packet, rip, size); 139 (*afp->af_output)(s, 0, from, size); 140 return; 141 142 case RIPCMD_TRACEON: 143 case RIPCMD_TRACEOFF: 144 /* verify message came from a privileged port */ 145 if ((*afp->af_portcheck)(from) == 0) 146 return; 147 if ((ifp = if_iflookup(from)) == 0) { 148 syslog(LOG_ERR, "trace command from unknown router, %s", 149 (*afswitch[from->sa_family].af_format)(from, buf1, 150 sizeof(buf1))); 151 return; 152 } 153 154 if ((ifp->int_flags & 155 (IFF_BROADCAST|IFF_POINTOPOINT|IFF_REMOTE)) == 0) { 156 syslog(LOG_ERR, 157 "trace command from router %s, with bad flags %x", 158 (*afswitch[from->sa_family].af_format)(from, buf1, 159 sizeof(buf1)), 160 ifp->int_flags); 161 return; 162 } 163 164 if ((ifp->int_flags & IFF_PASSIVE) != 0) { 165 syslog(LOG_ERR, 166 "trace command from %s on an active interface", 167 (*afswitch[from->sa_family].af_format)(from, buf1, 168 sizeof(buf1))); 169 return; 170 } 171 172 ((char *)rip)[size] = '\0'; 173 if (rip->rip_cmd == RIPCMD_TRACEON) 174 traceon(rip->rip_tracefile); 175 else 176 traceoff(); 177 return; 178 179 case RIPCMD_RESPONSE: 180 /* verify message came from a router */ 181 if ((*afp->af_portmatch)(from) == 0) 182 return; 183 (*afp->af_canon)(from); 184 /* are we talking to ourselves? */ 185 ifp = if_ifwithaddr(from); 186 if (ifp) { 187 if (ifp->int_flags & IFF_PASSIVE) { 188 syslog(LOG_ERR, 189 "bogus input (from passive interface, %s)", 190 (*afswitch[from->sa_family].af_format)(from, 191 buf1, sizeof(buf1))); 192 return; 193 } 194 rt = rtfind(from); 195 if (rt == 0 || ((rt->rt_state & RTS_INTERFACE) == 0) && 196 rt->rt_metric >= ifp->int_metric) 197 addrouteforif(ifp); 198 else 199 rt->rt_timer = 0; 200 return; 201 } 202 /* 203 * Update timer for interface on which the packet arrived. 204 * If from other end of a point-to-point link that isn't 205 * in the routing tables, (re-)add the route. 206 */ 207 if ((rt = rtfind(from)) && 208 (rt->rt_state & (RTS_INTERFACE | RTS_REMOTE))) 209 rt->rt_timer = 0; 210 else if ((ifp = if_ifwithdstaddr(from)) && 211 (rt == 0 || rt->rt_metric >= ifp->int_metric)) 212 addrouteforif(ifp); 213 /* 214 * "Authenticate" router from which message originated. 215 * We accept routing packets from routers directly connected 216 * via broadcast or point-to-point networks, 217 * and from those listed in /etc/gateways. 218 */ 219 if ((ifp = if_iflookup(from)) == 0 || (ifp->int_flags & 220 (IFF_BROADCAST | IFF_POINTOPOINT | IFF_REMOTE)) == 0 || 221 ifp->int_flags & IFF_PASSIVE) { 222 if (memcmp(from, &badfrom, sizeof(badfrom)) != 0) { 223 syslog(LOG_ERR, 224 "packet from unknown router, %s", 225 (*afswitch[from->sa_family].af_format)(from, 226 buf1, sizeof(buf1))); 227 badfrom = *from; 228 } 229 return; 230 } 231 size -= 4 * sizeof (char); 232 n = rip->rip_nets; 233 for (; size > 0; size -= sizeof (struct netinfo), n++) { 234 if (size < sizeof (struct netinfo)) 235 break; 236 #if BSD < 198810 237 if (sizeof(n->rip_dst.sa_family) > 1) /* XXX */ 238 n->rip_dst.sa_family = 239 ntohs(n->rip_dst.sa_family); 240 #else 241 n->rip_dst.sa_family = 242 ntohs(osa(n->rip_dst)->sa_family); 243 n->rip_dst.sa_len = sizeof(n->rip_dst); 244 #endif 245 n->rip_metric = ntohl(n->rip_metric); 246 if (n->rip_dst.sa_family >= af_max || 247 (afp = &afswitch[n->rip_dst.sa_family])->af_hash == 248 (int (*)())0) { 249 syslog(LOG_INFO, 250 "route in unsupported address family (%d), from %s (af %d)\n", 251 n->rip_dst.sa_family, 252 (*afswitch[from->sa_family].af_format)(from, 253 buf1, sizeof(buf1)), 254 from->sa_family); 255 continue; 256 } 257 if (((*afp->af_checkhost)(&n->rip_dst)) == 0) { 258 syslog(LOG_DEBUG, 259 "bad host %s in route from %s (af %d)\n", 260 (*afswitch[n->rip_dst.sa_family].af_format)( 261 &n->rip_dst, buf1, sizeof(buf1)), 262 (*afswitch[from->sa_family].af_format)(from, 263 buf2, sizeof(buf2)), 264 from->sa_family); 265 continue; 266 } 267 if (n->rip_metric == 0 || 268 (unsigned) n->rip_metric > HOPCNT_INFINITY) { 269 if (memcmp(from, &badfrom2, 270 sizeof(badfrom2)) != 0) { 271 syslog(LOG_ERR, 272 "bad metric (%d) from %s\n", 273 n->rip_metric, 274 (*afswitch[from->sa_family].af_format)(from, 275 buf1, sizeof(buf1))); 276 badfrom2 = *from; 277 } 278 continue; 279 } 280 /* 281 * Adjust metric according to incoming interface. 282 */ 283 if ((unsigned) n->rip_metric < HOPCNT_INFINITY) 284 n->rip_metric += ifp->int_metric; 285 if ((unsigned) n->rip_metric > HOPCNT_INFINITY) 286 n->rip_metric = HOPCNT_INFINITY; 287 rt = rtlookup(&n->rip_dst); 288 if (rt == 0 || 289 (rt->rt_state & (RTS_INTERNAL|RTS_INTERFACE)) == 290 (RTS_INTERNAL|RTS_INTERFACE)) { 291 /* 292 * If we're hearing a logical network route 293 * back from a peer to which we sent it, 294 * ignore it. 295 */ 296 if (rt && rt->rt_state & RTS_SUBNET && 297 (*afp->af_sendroute)(rt, from)) 298 continue; 299 if ((unsigned)n->rip_metric < HOPCNT_INFINITY) { 300 /* 301 * Look for an equivalent route that 302 * includes this one before adding 303 * this route. 304 */ 305 rt = rtfind(&n->rip_dst); 306 if (rt && equal(from, &rt->rt_router)) 307 continue; 308 rtadd(&n->rip_dst, from, n->rip_metric, 0); 309 changes++; 310 } 311 continue; 312 } 313 314 /* 315 * Update if from gateway and different, 316 * shorter, or equivalent but old route 317 * is getting stale. 318 */ 319 if (equal(from, &rt->rt_router)) { 320 if (n->rip_metric != rt->rt_metric) { 321 rtchange(rt, from, 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, from, 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 extern long random(); 357 358 if (now.tv_sec - lastbcast.tv_sec >= MIN_WAITTIME && 359 timercmp(&nextbcast, &now, <)) { 360 if (traceactions) 361 fprintf(ftrace, "send dynamic update\n"); 362 toall(supply, RTS_CHANGED, ifp); 363 lastbcast = now; 364 needupdate = 0; 365 nextbcast.tv_sec = 0; 366 } else { 367 needupdate++; 368 if (traceactions) 369 fprintf(ftrace, "delay dynamic update\n"); 370 } 371 #define RANDOMDELAY() (MIN_WAITTIME * 1000000 + \ 372 (u_long)random() % ((MAX_WAITTIME - MIN_WAITTIME) * 1000000)) 373 374 if (nextbcast.tv_sec == 0) { 375 delay = RANDOMDELAY(); 376 if (traceactions) 377 fprintf(ftrace, 378 "inhibit dynamic update for %d usec\n", 379 delay); 380 nextbcast.tv_sec = delay / 1000000; 381 nextbcast.tv_usec = delay % 1000000; 382 timeradd(&nextbcast, &now, &nextbcast); 383 /* 384 * If the next possibly dynamic update 385 * is within MIN_WAITTIME of the next full update, 386 * force the delay past the full update, 387 * or we might send a dynamic update just before 388 * the full update. 389 */ 390 if (nextbcast.tv_sec > lastfullupdate.tv_sec + 391 SUPPLY_INTERVAL - MIN_WAITTIME) 392 nextbcast.tv_sec = lastfullupdate.tv_sec + 393 SUPPLY_INTERVAL + 1; 394 } 395 } 396 } 397
Indexes created Wed Sep 24 05:09:52 GMT 2025