usr.sbin/in.routed/table.c

66 struct timeval age_timer;		/* next check of old routes */
77  * It is desirable to "aggregate" routes, to combine differing routes of
79  * or to suppress redundant routes, routes that add no information to
80  * routes with smaller netmasks.
82  * A route is redundant if and only if any and all routes with smaller
83  * but matching netmasks and nets are the same.  Since routes are
84  * kept sorted in the radix tree, redundant routes always come second.
86  * There are two kinds of aggregations.  First, two routes of the same bit
91  * coarse mask provided no incompatible routes with intermediate masks
92  * are present.  The second kind of aggregation involves suppressing routes.
97  * This code relies on the radix tree walk encountering routes
141 	 * Note that the order in which the radix tree code emits routes
231  * Flush routes waiting for aggregation.
232  * This must not suppress a route unless it is known that among all routes
234  * appropriate.  This is ensured by scanning the routes in lexical order,
235  * and with the most restrictive mask first among routes to the same
239 ag_flush(in_addr_t lim_dst_h,	/* flush routes to here */
252 		/* Work on only the specified routes. */
312 /* Try to aggregate a route with previous routes. */
334 	 * Don't bother trying to aggregate routes with non-contiguous
365 		 * Suppress old routes (i.e. combine with compatible routes
371 		 * This check keeps poor routes (e.g. with large hop counts)
372 		 * from preventing suppression of finer routes.
410 	 * Since the routes are encountered in lexical order,
427 				 * We have two routes to the same destination,
467 				 * multiple routes to same dest/mask with
476 		 * If one of the routes can be promoted and the other can
489 		 * A pair of even/odd twin routes can be combined
500 			 * Since the routes are encountered in order,
503 			 * Combine and promote (aggregate) the pair of routes.
612 	 * When we can no longer promote and combine routes,
614 	 * any finer routes that we know will never be aggregated by
1016  * responsible for adding new static routes to the daemon table.
1044 			 * way to compare metrics on static routes
1069 		 * RTM_CHANGE of interface routes
1234 	 * Put static routes with real metrics into the daemon table so
1326  * Eventually the daemon will delete any extra routes.
1344 	mib2_ipRouteEntry_t routes[8];
1388 		dbuf.buf = (caddr_t)routes;
1389 		dbuf.maxlen = sizeof (routes);
1441 		for (rp = routes; nroutes > 0; ++rp, nroutes--) {
1520 			 * Note static routes and interface routes, and also
1523 			 * unneeded changes.  Keep the old kernel routes for a
1544 			 * KS_DELETED routes have been removed from the
1547 			 * for KS_DELETED routes here.
1878 /* after aggregating, note routes that belong in the kernel */
1888 	 * Do not install bad routes if they are not already present.
1889 	 * This includes routes that had RS_NET_SYN for interfaces that
1928 			 * Must delete bad interface routes etc.
1984 	/* Do not install synthetic routes */
1989 	 * Do not install static routes here. Only
2004 		 * aggregate, ordinary good routes without regard to
2011 		 * Do not install host routes directly to hosts, to avoid
2020 		 * Do not install routes for "external" remote interfaces.
2025 		/* Interfaces should override received routes. */
2047 			 * Do not aggregate IS_PASSIVE routes.
2063 	 * dump all routes that have the same metric as rt_spares[0]
2069 		/* Do not install external routes */
2105 			/* Do not touch local interface routes */
2112 			/* Do not touch static routes */
2119 			/* check hold on routes deleted by the operator */
2163 			 * This deletes routes that disappear from the
2165 			 * will clear the bit for routes that have not
2208  * Delete all routes generated from ICMP Redirects that use a given gateway,
2209  * as well as old redirected routes.
2314 		msglog("have maximum (%d) routes", total_routes);
2390 	/* Keep various things from deciding ageless routes are stale. */
2438 	/* Do not change permanent routes */
2647 	/* fix any spare routes through the interface */
2668 	/* Bad routes for other than interfaces are easy. */
2696 	/* fix any spare routes through the interface */
2733 	 * age all of the spare routes, including the primary route
2744 				 * routes are stale
2750 			/* forget RIP routes after RIP has been turned off. */
2756 		/* age failing routes */
2762 		/* trash the spare routes when they go bad */
2797 /* Watch for dead routes and interfaces. */
2805 	 * If not listening to RIP, there is no need to age the routes in
2849 	/* Age routes. */
2853 	 * delete old redirected routes to keep the kernel table small