input.c revision 1.1
1 /* 2 * Copyright (c) 1983, 1988 Regents of the University of California. 3 * 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[] = "@(#)input.c 5.22 (Berkeley) 6/1/90"; 36 #endif /* not lint */ 37 38 /* 39 * Routing Table Management Daemon 40 */ 41 #include "defs.h" 42 #include <sys/syslog.h> 43 44 /* 45 * Process a newly received packet. 46 */ 47 rip_input(from, rip, size) 48 struct sockaddr *from; 49 register struct rip *rip; 50 int size; 51 { 52 register struct rt_entry *rt; 53 register struct netinfo *n; 54 register struct interface *ifp; 55 struct interface *if_ifwithdstaddr(); 56 int count, changes = 0; 57 register struct afswitch *afp; 58 static struct sockaddr badfrom, badfrom2; 59 60 ifp = 0; 61 TRACE_INPUT(ifp, from, (char *)rip, size); 62 if (from->sa_family >= af_max || 63 (afp = &afswitch[from->sa_family])->af_hash == (int (*)())0) { 64 syslog(LOG_INFO, 65 "\"from\" address in unsupported address family (%d), cmd %d\n", 66 from->sa_family, rip->rip_cmd); 67 return; 68 } 69 if (rip->rip_vers == 0) { 70 syslog(LOG_ERR, 71 "RIP version 0 packet received from %s! (cmd %d)", 72 (*afswitch[from->sa_family].af_format)(from), rip->rip_cmd); 73 return; 74 } 75 switch (rip->rip_cmd) { 76 77 case RIPCMD_REQUEST: 78 n = rip->rip_nets; 79 count = size - ((char *)n - (char *)rip); 80 if (count < sizeof (struct netinfo)) 81 return; 82 for (; count > 0; n++) { 83 if (count < sizeof (struct netinfo)) 84 break; 85 count -= sizeof (struct netinfo); 86 87 #if BSD < 198810 88 if (sizeof(n->rip_dst.sa_family) > 1) /* XXX */ 89 n->rip_dst.sa_family = ntohs(n->rip_dst.sa_family); 90 #else 91 #define osa(x) ((struct osockaddr *)(&(x))) 92 n->rip_dst.sa_family = 93 ntohs(osa(n->rip_dst)->sa_family); 94 n->rip_dst.sa_len = sizeof(n->rip_dst); 95 #endif 96 n->rip_metric = ntohl(n->rip_metric); 97 /* 98 * A single entry with sa_family == AF_UNSPEC and 99 * metric ``infinity'' means ``all routes''. 100 * We respond to routers only if we are acting 101 * as a supplier, or to anyone other than a router 102 * (eg, query). 103 */ 104 if (n->rip_dst.sa_family == AF_UNSPEC && 105 n->rip_metric == HOPCNT_INFINITY && count == 0) { 106 if (supplier || (*afp->af_portmatch)(from) == 0) 107 supply(from, 0, 0, 0); 108 return; 109 } 110 if (n->rip_dst.sa_family < af_max && 111 afswitch[n->rip_dst.sa_family].af_hash) 112 rt = rtlookup(&n->rip_dst); 113 else 114 rt = 0; 115 #define min(a, b) (a < b ? a : b) 116 n->rip_metric = rt == 0 ? HOPCNT_INFINITY : 117 min(rt->rt_metric + 1, HOPCNT_INFINITY); 118 #if BSD < 198810 119 if (sizeof(n->rip_dst.sa_family) > 1) /* XXX */ 120 n->rip_dst.sa_family = htons(n->rip_dst.sa_family); 121 #else 122 osa(n->rip_dst)->sa_family = 123 htons(n->rip_dst.sa_family); 124 #endif 125 n->rip_metric = htonl(n->rip_metric); 126 } 127 rip->rip_cmd = RIPCMD_RESPONSE; 128 bcopy((char *)rip, packet, size); 129 (*afp->af_output)(s, 0, from, size); 130 return; 131 132 case RIPCMD_TRACEON: 133 case RIPCMD_TRACEOFF: 134 /* verify message came from a privileged port */ 135 if ((*afp->af_portcheck)(from) == 0) 136 return; 137 if ((ifp = if_iflookup(from)) == 0 || (ifp->int_flags & 138 (IFF_BROADCAST | IFF_POINTOPOINT | IFF_REMOTE)) == 0 || 139 ifp->int_flags & IFF_PASSIVE) { 140 syslog(LOG_ERR, "trace command from unknown router, %s", 141 (*afswitch[from->sa_family].af_format)(from)); 142 return; 143 } 144 ((char *)rip)[size] = '\0'; 145 if (rip->rip_cmd == RIPCMD_TRACEON) 146 traceon(rip->rip_tracefile); 147 else 148 traceoff(); 149 return; 150 151 case RIPCMD_RESPONSE: 152 /* verify message came from a router */ 153 if ((*afp->af_portmatch)(from) == 0) 154 return; 155 (*afp->af_canon)(from); 156 /* are we talking to ourselves? */ 157 ifp = if_ifwithaddr(from); 158 if (ifp) { 159 if (ifp->int_flags & IFF_PASSIVE) { 160 syslog(LOG_ERR, 161 "bogus input (from passive interface, %s)", 162 (*afswitch[from->sa_family].af_format)(from)); 163 return; 164 } 165 rt = rtfind(from); 166 if (rt == 0 || ((rt->rt_state & RTS_INTERFACE) == 0) && 167 rt->rt_metric >= ifp->int_metric) 168 addrouteforif(ifp); 169 else 170 rt->rt_timer = 0; 171 return; 172 } 173 /* 174 * Update timer for interface on which the packet arrived. 175 * If from other end of a point-to-point link that isn't 176 * in the routing tables, (re-)add the route. 177 */ 178 if ((rt = rtfind(from)) && 179 (rt->rt_state & (RTS_INTERFACE | RTS_REMOTE))) 180 rt->rt_timer = 0; 181 else if ((ifp = if_ifwithdstaddr(from)) && 182 (rt == 0 || rt->rt_metric >= ifp->int_metric)) 183 addrouteforif(ifp); 184 /* 185 * "Authenticate" router from which message originated. 186 * We accept routing packets from routers directly connected 187 * via broadcast or point-to-point networks, 188 * and from those listed in /etc/gateways. 189 */ 190 if ((ifp = if_iflookup(from)) == 0 || (ifp->int_flags & 191 (IFF_BROADCAST | IFF_POINTOPOINT | IFF_REMOTE)) == 0 || 192 ifp->int_flags & IFF_PASSIVE) { 193 if (bcmp((char *)from, (char *)&badfrom, 194 sizeof(badfrom)) != 0) { 195 syslog(LOG_ERR, 196 "packet from unknown router, %s", 197 (*afswitch[from->sa_family].af_format)(from)); 198 badfrom = *from; 199 } 200 return; 201 } 202 size -= 4 * sizeof (char); 203 n = rip->rip_nets; 204 for (; size > 0; size -= sizeof (struct netinfo), n++) { 205 if (size < sizeof (struct netinfo)) 206 break; 207 #if BSD < 198810 208 if (sizeof(n->rip_dst.sa_family) > 1) /* XXX */ 209 n->rip_dst.sa_family = 210 ntohs(n->rip_dst.sa_family); 211 #else 212 n->rip_dst.sa_family = 213 ntohs(osa(n->rip_dst)->sa_family); 214 n->rip_dst.sa_len = sizeof(n->rip_dst); 215 #endif 216 n->rip_metric = ntohl(n->rip_metric); 217 if (n->rip_dst.sa_family >= af_max || 218 (afp = &afswitch[n->rip_dst.sa_family])->af_hash == 219 (int (*)())0) { 220 syslog(LOG_INFO, 221 "route in unsupported address family (%d), from %s (af %d)\n", 222 n->rip_dst.sa_family, 223 (*afswitch[from->sa_family].af_format)(from), 224 from->sa_family); 225 continue; 226 } 227 if (((*afp->af_checkhost)(&n->rip_dst)) == 0) { 228 syslog(LOG_DEBUG, 229 "bad host in route from %s (af %d)\n", 230 (*afswitch[from->sa_family].af_format)(from), 231 from->sa_family); 232 continue; 233 } 234 if (n->rip_metric == 0 || 235 (unsigned) n->rip_metric > HOPCNT_INFINITY) { 236 if (bcmp((char *)from, (char *)&badfrom2, 237 sizeof(badfrom2)) != 0) { 238 syslog(LOG_ERR, 239 "bad metric (%d) from %s\n", 240 n->rip_metric, 241 (*afswitch[from->sa_family].af_format)(from)); 242 badfrom2 = *from; 243 } 244 continue; 245 } 246 /* 247 * Adjust metric according to incoming interface. 248 */ 249 if ((unsigned) n->rip_metric < HOPCNT_INFINITY) 250 n->rip_metric += ifp->int_metric; 251 if ((unsigned) n->rip_metric > HOPCNT_INFINITY) 252 n->rip_metric = HOPCNT_INFINITY; 253 rt = rtlookup(&n->rip_dst); 254 if (rt == 0 || 255 (rt->rt_state & (RTS_INTERNAL|RTS_INTERFACE)) == 256 (RTS_INTERNAL|RTS_INTERFACE)) { 257 /* 258 * If we're hearing a logical network route 259 * back from a peer to which we sent it, 260 * ignore it. 261 */ 262 if (rt && rt->rt_state & RTS_SUBNET && 263 (*afp->af_sendroute)(rt, from)) 264 continue; 265 if ((unsigned)n->rip_metric < HOPCNT_INFINITY) { 266 /* 267 * Look for an equivalent route that 268 * includes this one before adding 269 * this route. 270 */ 271 rt = rtfind(&n->rip_dst); 272 if (rt && equal(from, &rt->rt_router)) 273 continue; 274 rtadd(&n->rip_dst, from, n->rip_metric, 0); 275 changes++; 276 } 277 continue; 278 } 279 280 /* 281 * Update if from gateway and different, 282 * shorter, or equivalent but old route 283 * is getting stale. 284 */ 285 if (equal(from, &rt->rt_router)) { 286 if (n->rip_metric != rt->rt_metric) { 287 rtchange(rt, from, n->rip_metric); 288 changes++; 289 rt->rt_timer = 0; 290 if (rt->rt_metric >= HOPCNT_INFINITY) 291 rt->rt_timer = 292 GARBAGE_TIME - EXPIRE_TIME; 293 } else if (rt->rt_metric < HOPCNT_INFINITY) 294 rt->rt_timer = 0; 295 } else if ((unsigned) n->rip_metric < rt->rt_metric || 296 (rt->rt_metric == n->rip_metric && 297 rt->rt_timer > (EXPIRE_TIME/2) && 298 (unsigned) n->rip_metric < HOPCNT_INFINITY)) { 299 rtchange(rt, from, n->rip_metric); 300 changes++; 301 rt->rt_timer = 0; 302 } 303 } 304 break; 305 } 306 307 /* 308 * If changes have occurred, and if we have not sent a broadcast 309 * recently, send a dynamic update. This update is sent only 310 * on interfaces other than the one on which we received notice 311 * of the change. If we are within MIN_WAITTIME of a full update, 312 * don't bother sending; if we just sent a dynamic update 313 * and set a timer (nextbcast), delay until that time. 314 * If we just sent a full update, delay the dynamic update. 315 * Set a timer for a randomized value to suppress additional 316 * dynamic updates until it expires; if we delayed sending 317 * the current changes, set needupdate. 318 */ 319 if (changes && supplier && 320 now.tv_sec - lastfullupdate.tv_sec < SUPPLY_INTERVAL-MAX_WAITTIME) { 321 u_long delay; 322 extern long random(); 323 324 if (now.tv_sec - lastbcast.tv_sec >= MIN_WAITTIME && 325 timercmp(&nextbcast, &now, <)) { 326 if (traceactions) 327 fprintf(ftrace, "send dynamic update\n"); 328 toall(supply, RTS_CHANGED, ifp); 329 lastbcast = now; 330 needupdate = 0; 331 nextbcast.tv_sec = 0; 332 } else { 333 needupdate++; 334 if (traceactions) 335 fprintf(ftrace, "delay dynamic update\n"); 336 } 337 #define RANDOMDELAY() (MIN_WAITTIME * 1000000 + \ 338 (u_long)random() % ((MAX_WAITTIME - MIN_WAITTIME) * 1000000)) 339 340 if (nextbcast.tv_sec == 0) { 341 delay = RANDOMDELAY(); 342 if (traceactions) 343 fprintf(ftrace, 344 "inhibit dynamic update for %d usec\n", 345 delay); 346 nextbcast.tv_sec = delay / 1000000; 347 nextbcast.tv_usec = delay % 1000000; 348 timevaladd(&nextbcast, &now); 349 /* 350 * If the next possibly dynamic update 351 * is within MIN_WAITTIME of the next full update, 352 * force the delay past the full update, 353 * or we might send a dynamic update just before 354 * the full update. 355 */ 356 if (nextbcast.tv_sec > lastfullupdate.tv_sec + 357 SUPPLY_INTERVAL - MIN_WAITTIME) 358 nextbcast.tv_sec = lastfullupdate.tv_sec + 359 SUPPLY_INTERVAL + 1; 360 } 361 } 362 } 363
Indexes created Tue Sep 23 20:09:58 GMT 2025