/**
* "When new links are added or opened, and if we're configured to add nexthop routes, try to add
* a new route for the given link." [DTN2]
*/
public void add_nexthop_route(final Link link) {
// "If we're configured to do so, create a route entry for the eid
// specified by the link when it connected, using the
// scheme-specific code to transform the URI to wildcard
// the service part" [DTN2]
EndpointID eid = link.remote_eid();
if (config_.add_nexthop_routes() && !eid.equals(EndpointID.NULL_EID())) {
EndpointIDPattern eid_pattern = new EndpointIDPattern(link.remote_eid());
// "attempt to build a route pattern from link's remote_eid" [DTN2]
if (!eid_pattern.append_service_wildcard())
// "else assign remote_eid as-is" [DTN2]
eid_pattern.assign(link.remote_eid());
RouteEntryVec ignored = new RouteEntryVec();
if (route_table_.get_matching(eid_pattern, link, ignored) == 0) {
RouteEntry entry = new RouteEntry(eid_pattern, link);
entry.set_action(ForwardingInfo.action_t.FORWARD_ACTION);
add_route(entry);
}
}
}
/**
* "Check the route table entries that match the given bundle and have not already been found in
* the bundle history. If a match is found, call fwd_to_nexthop on it." [DTN2]
*
* @param bundle the bundle to forward
* @return "the number of links on which the bundle was queued (i.e. the number of matching route
* entries.)" [DTN2]
*/
protected int route_bundle(Bundle bundle) {
RouteEntryVec matches = new RouteEntryVec();
Log.d(TAG, String.format("route_bundle: checking bundle %d", bundle.bundleid()));
// "check to see if forwarding is suppressed to all nodes" [DTN2]
if (bundle
.fwdlog()
.get_count(
EndpointIDPattern.WILDCARD_EID(),
ForwardingInfo.state_t.SUPPRESSED.getCode(),
ForwardingInfo.ANY_ACTION)
> 0) {
Log.i(
TAG,
String.format(
"route_bundle: " + "ignoring bundle %d since forwarding is suppressed",
bundle.bundleid()));
return 0;
}
Link null_link = null;
route_table_.get_matching(bundle.dest(), null_link, matches);
// "sort the matching routes by priority, allowing subclasses to
// override the way in which the sorting occurs" [DTN2]
sort_routes(matches);
Log.d(
TAG,
String.format(
"route_bundle bundle id %d: checking %d route entry matches",
bundle.bundleid(), matches.size()));
int count = 0;
Iterator<RouteEntry> itr = matches.iterator();
while (itr.hasNext()) {
RouteEntry route = itr.next();
Log.d(
TAG,
String.format(
"checking route entry %s link %s (%s)",
route.toString(), route.link().name(), route.link()));
if (!should_fwd(bundle, route)) {
continue;
}
if (deferred_list(route.link()).list().contains(bundle)) {
Log.d(
TAG,
String.format(
"route_bundle bundle %d: " + "ignoring link %s since already deferred",
bundle.bundleid(), route.link().name()));
continue;
}
// "because there may be bundles that already have deferred
// transmission on the link, we first call check_next_hop to
// get them into the queue before trying to route the new
// arrival, otherwise it might leapfrog the other deferred
// bundles" [DTN2]
check_next_hop(route.link());
if (!fwd_to_nexthop(bundle, route)) {
continue;
}
++count;
}
Log.d(
TAG,
String.format(
"route_bundle bundle id %d: forwarded on %d links", bundle.bundleid(), count));
return count;
}