input.c revision 1.9
1 /* $NetBSD: input.c,v 1.9 1995/03/18 15:00:31 cgd 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 1.9 1995/03/18 15:00:31 cgd 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 67 ifp = 0; 68 TRACE_INPUT(ifp, (struct sockaddr_in *)from, (char *)rip, size); 69 if (from->sa_family >= af_max || 70 (afp = &afswitch[from->sa_family])->af_hash == (int (*)())0) { 71 syslog(LOG_INFO, 72 "\"from\" address in unsupported address family (%d), cmd %d\n", 73 from->sa_family, rip->rip_cmd); 74 return; 75 } 76 if (rip->rip_vers == 0) { 77 syslog(LOG_ERR, 78 "RIP version 0 packet received from %s! (cmd %d)", 79 (*afswitch[from->sa_family].af_format)(from), rip->rip_cmd); 80 return; 81 } 82 switch (rip->rip_cmd) { 83 84 case RIPCMD_REQUEST: 85 n = rip->rip_nets; 86 count = size - ((char *)n - (char *)rip); 87 if (count < sizeof (struct netinfo)) 88 return; 89 for (; count > 0; n++) { 90 if (count < sizeof (struct netinfo)) 91 break; 92 count -= sizeof (struct netinfo); 93 94 #if BSD < 198810 95 if (sizeof(n->rip_dst.sa_family) > 1) /* XXX */ 96 n->rip_dst.sa_family = ntohs(n->rip_dst.sa_family); 97 #else 98 #define osa(x) ((struct osockaddr *)(&(x))) 99 n->rip_dst.sa_family = 100 ntohs(osa(n->rip_dst)->sa_family); 101 n->rip_dst.sa_len = sizeof(n->rip_dst); 102 #endif 103 n->rip_metric = ntohl(n->rip_metric); 104 /* 105 * A single entry with sa_family == AF_UNSPEC and 106 * metric ``infinity'' means ``all routes''. 107 * We respond to routers only if we are acting 108 * as a supplier, or to anyone other than a router 109 * (eg, query). 110 */ 111 if (n->rip_dst.sa_family == AF_UNSPEC && 112 n->rip_metric == HOPCNT_INFINITY && count == 0) { 113 if (supplier || (*afp->af_portmatch)(from) == 0) 114 supply(from, 0, 0, 0); 115 return; 116 } 117 if (n->rip_dst.sa_family < af_max && 118 afswitch[n->rip_dst.sa_family].af_hash) 119 rt = rtlookup(&n->rip_dst); 120 else 121 rt = 0; 122 #define min(a, b) (a < b ? a : b) 123 n->rip_metric = rt == 0 ? HOPCNT_INFINITY : 124 min(rt->rt_metric + 1, HOPCNT_INFINITY); 125 #if BSD < 198810 126 if (sizeof(n->rip_dst.sa_family) > 1) /* XXX */ 127 n->rip_dst.sa_family = htons(n->rip_dst.sa_family); 128 #else 129 osa(n->rip_dst)->sa_family = 130 htons(n->rip_dst.sa_family); 131 #endif 132 n->rip_metric = htonl(n->rip_metric); 133 } 134 rip->rip_cmd = RIPCMD_RESPONSE; 135 memcpy(packet, rip, size); 136 (*afp->af_output)(s, 0, from, size); 137 return; 138 139 case RIPCMD_TRACEON: 140 case RIPCMD_TRACEOFF: 141 /* verify message came from a privileged port */ 142 if ((*afp->af_portcheck)(from) == 0) 143 return; 144 if ((ifp = if_iflookup(from)) == 0 || (ifp->int_flags & 145 (IFF_BROADCAST | IFF_POINTOPOINT | IFF_REMOTE)) == 0 || 146 ifp->int_flags & IFF_PASSIVE) { 147 syslog(LOG_ERR, "trace command from unknown router, %s", 148 (*afswitch[from->sa_family].af_format)(from)); 149 return; 150 } 151 ((char *)rip)[size] = '\0'; 152 if (rip->rip_cmd == RIPCMD_TRACEON) 153 traceon(rip->rip_tracefile); 154 else 155 traceoff(); 156 return; 157 158 case RIPCMD_RESPONSE: 159 /* verify message came from a router */ 160 if ((*afp->af_portmatch)(from) == 0) 161 return; 162 (*afp->af_canon)(from); 163 /* are we talking to ourselves? */ 164 ifp = if_ifwithaddr(from); 165 if (ifp) { 166 if (ifp->int_flags & IFF_PASSIVE) { 167 syslog(LOG_ERR, 168 "bogus input (from passive interface, %s)", 169 (*afswitch[from->sa_family].af_format)(from)); 170 return; 171 } 172 rt = rtfind(from); 173 if (rt == 0 || ((rt->rt_state & RTS_INTERFACE) == 0) && 174 rt->rt_metric >= ifp->int_metric) 175 addrouteforif(ifp); 176 else 177 rt->rt_timer = 0; 178 return; 179 } 180 /* 181 * Update timer for interface on which the packet arrived. 182 * If from other end of a point-to-point link that isn't 183 * in the routing tables, (re-)add the route. 184 */ 185 if ((rt = rtfind(from)) && 186 (rt->rt_state & (RTS_INTERFACE | RTS_REMOTE))) 187 rt->rt_timer = 0; 188 else if ((ifp = if_ifwithdstaddr(from)) && 189 (rt == 0 || rt->rt_metric >= ifp->int_metric)) 190 addrouteforif(ifp); 191 /* 192 * "Authenticate" router from which message originated. 193 * We accept routing packets from routers directly connected 194 * via broadcast or point-to-point networks, 195 * and from those listed in /etc/gateways. 196 */ 197 if ((ifp = if_iflookup(from)) == 0 || (ifp->int_flags & 198 (IFF_BROADCAST | IFF_POINTOPOINT | IFF_REMOTE)) == 0 || 199 ifp->int_flags & IFF_PASSIVE) { 200 if (memcmp(from, &badfrom, sizeof(badfrom)) != 0) { 201 syslog(LOG_ERR, 202 "packet from unknown router, %s", 203 (*afswitch[from->sa_family].af_format)(from)); 204 badfrom = *from; 205 } 206 return; 207 } 208 size -= 4 * sizeof (char); 209 n = rip->rip_nets; 210 for (; size > 0; size -= sizeof (struct netinfo), n++) { 211 if (size < sizeof (struct netinfo)) 212 break; 213 #if BSD < 198810 214 if (sizeof(n->rip_dst.sa_family) > 1) /* XXX */ 215 n->rip_dst.sa_family = 216 ntohs(n->rip_dst.sa_family); 217 #else 218 n->rip_dst.sa_family = 219 ntohs(osa(n->rip_dst)->sa_family); 220 n->rip_dst.sa_len = sizeof(n->rip_dst); 221 #endif 222 n->rip_metric = ntohl(n->rip_metric); 223 if (n->rip_dst.sa_family >= af_max || 224 (afp = &afswitch[n->rip_dst.sa_family])->af_hash == 225 (int (*)())0) { 226 syslog(LOG_INFO, 227 "route in unsupported address family (%d), from %s (af %d)\n", 228 n->rip_dst.sa_family, 229 (*afswitch[from->sa_family].af_format)(from), 230 from->sa_family); 231 continue; 232 } 233 if (((*afp->af_checkhost)(&n->rip_dst)) == 0) { 234 syslog(LOG_DEBUG, 235 "bad host in route from %s (af %d)\n", 236 (*afswitch[from->sa_family].af_format)(from), 237 from->sa_family); 238 continue; 239 } 240 if (n->rip_metric == 0 || 241 (unsigned) n->rip_metric > HOPCNT_INFINITY) { 242 if (memcmp(from, &badfrom2, 243 sizeof(badfrom2)) != 0) { 244 syslog(LOG_ERR, 245 "bad metric (%d) from %s\n", 246 n->rip_metric, 247 (*afswitch[from->sa_family].af_format)(from)); 248 badfrom2 = *from; 249 } 250 continue; 251 } 252 /* 253 * Adjust metric according to incoming interface. 254 */ 255 if ((unsigned) n->rip_metric < HOPCNT_INFINITY) 256 n->rip_metric += ifp->int_metric; 257 if ((unsigned) n->rip_metric > HOPCNT_INFINITY) 258 n->rip_metric = HOPCNT_INFINITY; 259 rt = rtlookup(&n->rip_dst); 260 if (rt == 0 || 261 (rt->rt_state & (RTS_INTERNAL|RTS_INTERFACE)) == 262 (RTS_INTERNAL|RTS_INTERFACE)) { 263 /* 264 * If we're hearing a logical network route 265 * back from a peer to which we sent it, 266 * ignore it. 267 */ 268 if (rt && rt->rt_state & RTS_SUBNET && 269 (*afp->af_sendroute)(rt, from)) 270 continue; 271 if ((unsigned)n->rip_metric < HOPCNT_INFINITY) { 272 /* 273 * Look for an equivalent route that 274 * includes this one before adding 275 * this route. 276 */ 277 rt = rtfind(&n->rip_dst); 278 if (rt && equal(from, &rt->rt_router)) 279 continue; 280 rtadd(&n->rip_dst, from, n->rip_metric, 0); 281 changes++; 282 } 283 continue; 284 } 285 286 /* 287 * Update if from gateway and different, 288 * shorter, or equivalent but old route 289 * is getting stale. 290 */ 291 if (equal(from, &rt->rt_router)) { 292 if (n->rip_metric != rt->rt_metric) { 293 rtchange(rt, from, n->rip_metric); 294 changes++; 295 rt->rt_timer = 0; 296 if (rt->rt_metric >= HOPCNT_INFINITY) 297 rt->rt_timer = 298 GARBAGE_TIME - EXPIRE_TIME; 299 } else if (rt->rt_metric < HOPCNT_INFINITY) 300 rt->rt_timer = 0; 301 } else if ((unsigned) n->rip_metric < rt->rt_metric || 302 (rt->rt_metric == n->rip_metric && 303 rt->rt_timer > (EXPIRE_TIME/2) && 304 (unsigned) n->rip_metric < HOPCNT_INFINITY)) { 305 rtchange(rt, from, n->rip_metric); 306 changes++; 307 rt->rt_timer = 0; 308 } 309 } 310 break; 311 } 312 313 /* 314 * If changes have occurred, and if we have not sent a broadcast 315 * recently, send a dynamic update. This update is sent only 316 * on interfaces other than the one on which we received notice 317 * of the change. If we are within MIN_WAITTIME of a full update, 318 * don't bother sending; if we just sent a dynamic update 319 * and set a timer (nextbcast), delay until that time. 320 * If we just sent a full update, delay the dynamic update. 321 * Set a timer for a randomized value to suppress additional 322 * dynamic updates until it expires; if we delayed sending 323 * the current changes, set needupdate. 324 */ 325 if (changes && supplier && 326 now.tv_sec - lastfullupdate.tv_sec < SUPPLY_INTERVAL-MAX_WAITTIME) { 327 u_long delay; 328 extern long random(); 329 330 if (now.tv_sec - lastbcast.tv_sec >= MIN_WAITTIME && 331 timercmp(&nextbcast, &now, <)) { 332 if (traceactions) 333 fprintf(ftrace, "send dynamic update\n"); 334 toall(supply, RTS_CHANGED, ifp); 335 lastbcast = now; 336 needupdate = 0; 337 nextbcast.tv_sec = 0; 338 } else { 339 needupdate++; 340 if (traceactions) 341 fprintf(ftrace, "delay dynamic update\n"); 342 } 343 #define RANDOMDELAY() (MIN_WAITTIME * 1000000 + \ 344 (u_long)random() % ((MAX_WAITTIME - MIN_WAITTIME) * 1000000)) 345 346 if (nextbcast.tv_sec == 0) { 347 delay = RANDOMDELAY(); 348 if (traceactions) 349 fprintf(ftrace, 350 "inhibit dynamic update for %d usec\n", 351 delay); 352 nextbcast.tv_sec = delay / 1000000; 353 nextbcast.tv_usec = delay % 1000000; 354 timevaladd(&nextbcast, &now); 355 /* 356 * If the next possibly dynamic update 357 * is within MIN_WAITTIME of the next full update, 358 * force the delay past the full update, 359 * or we might send a dynamic update just before 360 * the full update. 361 */ 362 if (nextbcast.tv_sec > lastfullupdate.tv_sec + 363 SUPPLY_INTERVAL - MIN_WAITTIME) 364 nextbcast.tv_sec = lastfullupdate.tv_sec + 365 SUPPLY_INTERVAL + 1; 366 } 367 } 368 } 369
Indexes created Wed Sep 24 22:09:59 GMT 2025