50 struct timeval age_timer;		/* next check of old routes */
59 /* zap any old routes through this gateway */
63 /* It is desirable to "aggregate" routes, to combine differing routes of
65  * or to suppress redundant routes, routes that add no information to
66  * routes with smaller netmasks.
68  * A route is redundant if and only if any and all routes with smaller
69  * but matching netmasks and nets are the same.  Since routes are
70  * kept sorted in the radix tree, redundant routes always come second.
72  * There are two kinds of aggregations.  First, two routes of the same bit
77  * coarse mask provided no incompatible routes with intermediate masks
78  * are present.  The second kind of aggregation involves suppressing routes.
83  * This code relies on the radix tree walk encountering routes
128 	 * Note that the order in which the radix tree code emits routes  in ag_out()
184 /* Flush routes waiting for aggregation.
186  *	routes with coarser masks that match it, the one with the longest
187  *	mask is appropriate.  This is ensured by scanning the routes
189  *	among routes to the same destination.
192 ag_flush(naddr lim_dst_h,		/* flush routes to here */  in ag_flush()
205 		/* work on only the specified routes */  in ag_flush()
270 /* Try to aggregate a route with previous routes.
319 		/* Suppress old routes (i.e. combine with compatible routes  in ag_check()
325 		 * This check keeps poor routes (e.g. with large hop counts)  in ag_check()
326 		 * from preventing suppression of finer routes.  in ag_check()
362 	 * Since the routes are encountered in lexical order,  in ag_check()
377 			/* We have two routes to the same destination.  in ag_check()
378 			 * Routes are encountered in lexical order, so a  in ag_check()
411 		/* If one of the routes can be promoted and the other can  in ag_check()
424 		/* A pair of even/odd twin routes can be combined  in ag_check()
435 			 * Since the routes are encountered in order,  in ag_check()
438 			 * Combine and promote (aggregate) the pair of routes.  in ag_check()
538 	/* When we can no longer promote and combine routes,  in ag_check()
540 	 * any finer routes that we know will never be aggregated by  in ag_check()
959 	/* Put static routes with real metrics into the daemon table so  in rtm_add()
1027  * Eventually the daemon will delete any extra routes.
1068 		 * BSD/OS 3.1, to not admit how many routes are in the  in flush_kern()
1103 		/* ignore cloned routes  in flush_kern()
1117 		/* Note static routes and interface routes, and also  in flush_kern()
1120 		 * unneeded changes.  Keep the old kernel routes for a  in flush_kern()
1326 /* after aggregating, note routes that belong in the kernel
1334 	/* Do not install bad routes if they are not already present.  in kern_out()
1335 	 * This includes routes that had RS_NET_SYN for interfaces that  in kern_out()
1362 		/* Must delete bad interface routes etc. to change them. */  in kern_out()
1413 	/* Do not install synthetic routes */  in walk_kern()
1421 		/* aggregate, ordinary good routes without regard to  in walk_kern()
1427 		/* Do not install host routes directly to hosts, to avoid  in walk_kern()
1436 		 * Do not install routes for "external" remote interfaces.  in walk_kern()
1441 		/* Interfaces should override received routes.  in walk_kern()
1458 	 * route suppress any RIP routes.  Eventually the RIP routes  in walk_kern()
1498 			/* Do not touch static routes */  in fix_kern()
1505 			/* check hold on routes deleted by the operator */  in fix_kern()
1540 			 * This deletes routes that disappear from the  in fix_kern()
1542 			 * will clear the bit for routes that have not  in fix_kern()
1586 /* Delete all routes generated from ICMP Redirects that use a given gateway,
1587  * as well as old redirected routes.
1734 		msglog("have maximum (%d) routes", total_routes);  in rtadd()
1780 	/* Keep various things from deciding ageless routes are stale.  in rtchange()
1823 	/* Do not change permanent routes */  in rtswitch()
1983 	/* fix any spare routes through the interface  in walk_bad()
2001 	/* Bad routes for other than interfaces are easy.  in walk_bad()
2027 	/* age all of the spare routes, including the primary route  in walk_age()
2037 				 * routes are stale  in walk_age()
2043 			/* forget RIP routes after RIP has been turned off.  in walk_age()
2051 		/* age failing routes  in walk_age()
2058 		/* trash the spare routes when they go bad */  in walk_age()
2089 /* Watch for dead routes and interfaces.
2097 	/* If not listening to RIP, there is no need to age the routes in  in age()
2139 	/* Age routes. */  in age()
2143 	/* delete old redirected routes to keep the kernel table small  in age()