freebsd-src/usr.sbin/mrouted/route.h

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/*
* The mrouted program is covered by the license in the accompanying file
* named "LICENSE". Use of the mrouted program represents acceptance of
* the terms and conditions listed in that file.
*
* The mrouted program is COPYRIGHT 1989 by The Board of Trustees of
* Leland Stanford Junior University.
*
*
1997-02-22 16:15:28 +00:00
* $Id$
*/
/*
* Routing Table Entry, one per subnet from which a multicast could originate.
* (Note: all addresses, subnet numbers and masks are kept in NETWORK order.)
*
* The Routing Table is stored as a doubly-linked list of these structures,
* ordered by decreasing value of rt_originmask and, secondarily, by
* decreasing value of rt_origin within each rt_originmask value.
* This data structure is efficient for generating route reports, whether
* full or partial, for processing received full reports, for clearing the
* CHANGED flags, and for periodically advancing the timers in all routes.
* It is not so efficient for updating a small number of routes in response
* to a partial report. In a stable topology, the latter are rare; if they
* turn out to be costing a lot, we can add an auxiliary hash table for
* faster access to arbitrary route entries.
*/
struct rtentry {
struct rtentry *rt_next; /* link to next entry MUST BE FIRST */
u_int32 rt_origin; /* subnet origin of multicasts */
u_int32 rt_originmask; /* subnet mask for origin */
short rt_originwidth; /* # bytes of origin subnet number */
u_char rt_metric; /* cost of route back to origin */
u_char rt_flags; /* RTF_ flags defined below */
u_int32 rt_gateway; /* first-hop gateway back to origin */
vifi_t rt_parent; /* incoming vif (ie towards origin) */
vifbitmap_t rt_children; /* outgoing children vifs */
vifbitmap_t rt_leaves; /* subset of outgoing children vifs */
u_int32 *rt_dominants; /* per vif dominant gateways */
u_int32 *rt_subordinates; /* per vif subordinate gateways */
u_int *rt_leaf_timers; /* per vif leaf confirmation timers */
u_int rt_timer; /* for timing out the route entry */
struct rtentry *rt_prev; /* link to previous entry */
struct gtable *rt_groups; /* link to active groups */
};
#define RTF_CHANGED 0x01 /* route changed but not reported */
#define RTF_LEAF_TIMING 0x02 /* some leaf timers are running */
#define ALL_ROUTES 0 /* possible arguments to report() */
#define CHANGED_ROUTES 1 /* and report_to_all_neighbors() */