MergedTable< A > Class Template Reference

Make two route RouteTables behave like one. More...

#include <rt_tab_merged.hh>

Inheritance diagram for MergedTable< A >:

List of all members.

Public Member Functions
	MergedTable (RouteTable< A > *table_a, RouteTable< A > *table_b)
	MergedTable Constructor.
int	add_route (const IPRouteEntry< A > &route, RouteTable< A > *caller)
	An add_route request from a parent table causes a lookup on the other parent table.
int	delete_route (const IPRouteEntry< A > *route, RouteTable< A > *caller)
	An delete_route request from a parent table also causes a lookup on the other parent table.
const IPRouteEntry< A > *	lookup_route (const IPNet< A > &net) const
	Lookup a specific subnet.
const IPRouteEntry< A > *	lookup_route (const A &addr) const
	Lookup an IP address to get the most specific (longest prefix length) route that matches this address.
RouteRange< A > *	lookup_route_range (const A &addr) const
	Lookup an IP address to get the most specific (longest prefix length) route that matches this address, along with the RouteRange information for this address and route.
TableType	type () const
void	replumb (RouteTable< A > *old_parent, RouteTable< A > *new_parent)
	replumb the parent tables, so that new_parent replaces old_parent.
string	str () const
	Render this MergedTable as a string for debugging purposes.
Private Attributes
RouteTable< A > *	_table_a
RouteTable< A > *	_table_b

---

Detailed Description

template<class A>
class MergedTable< A >

Make two route RouteTables behave like one.

MergedTable takes two routing tables and combines them together to form a single table, where routes for the same subnet with a lower admin distance override those with a higher admin distance.

The two parent tables are not actually merged.

An add_route request from a parent tables causes a lookup on the other parent table. If the route is better than the one from the other table, or no route exists in the other table, then the new route is passed downstream.

An delete_route request from a parent table also causes a lookup on the other parent table. The delete_route is propagated downstream. If an alternative route is found, then that is then propagated downsteam as an add_route to replace the deleted route.

Lookups from downsteam cause lookups on both parent tables. The better response is given.

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Constructor & Destructor Documentation

template<class A >

MergedTable< A >::MergedTable	(	RouteTable< A > *	table_a,
		RouteTable< A > *	table_b
	)

MergedTable Constructor.

Parameters:

table_a	one of two parent RouteTables.
table_b	one of two parent RouteTables.

---

Member Function Documentation

template<class A >

int MergedTable< A >::add_route	(	const IPRouteEntry< A > &	route,
		RouteTable< A > *	caller
	)		[virtual]

An add_route request from a parent table causes a lookup on the other parent table.

If the route is better than the one from the other table, or no route exists in the other table then it is passed downstream.

Parameters:

route	the new route.
caller	the parent table sending the new route.

Returns:

XORP_OK on success, otherwise XORP_ERROR.

Implements RouteTable< A >.

template<class A >

int MergedTable< A >::delete_route	(	const IPRouteEntry< A > *	route,
		RouteTable< A > *	caller
	)		[virtual]

An delete_route request from a parent table also causes a lookup on the other parent table.

The delete_route is propagated downstream. If an alternative route is found, then that is then propagated downsteam as an add_route to replace the deleted route.

Parameters:

route	the route to be deleted.
caller	the parent table sending the delete_route.

Returns:

XORP_OK on success, otherwise XORP_ERROR.

Implements RouteTable< A >.

template<class A >

const IPRouteEntry< A > * MergedTable< A >::lookup_route

(

const A &

addr

)

const [virtual]

Lookup an IP address to get the most specific (longest prefix length) route that matches this address.

The lookup will be sent to both parent tables. If both give an answer, then the more specific route is returned. If both routes have the same prefix length, then the route with the better admin_distance is returned.

Parameters:

addr	the IP address to look up.

Returns:

a pointer to the best most specific route entry if any entry matches, NULL otherwise.

Implements RouteTable< A >.

template<class A >

const IPRouteEntry< A > * MergedTable< A >::lookup_route

(

const IPNet< A > &

net

)

const [virtual]

Lookup a specific subnet.

The lookup will be sent to both parent tables. If both give an answer, then the route with the better admin_distance is returned.

Parameters:

net	the subnet to look up.

Returns:

a pointer to the route entry if it exists, NULL otherwise.

Implements RouteTable< A >.

template<class A >

RouteRange< A > * MergedTable< A >::lookup_route_range

(

const A &

addr

)

const [virtual]

Lookup an IP address to get the most specific (longest prefix length) route that matches this address, along with the RouteRange information for this address and route.

As with lookup_route, this involves querying both parent tables. The best, most specific route is returned, and the tightest bounds on the answer are returned.

See also:

RouteRange

Parameters:

addr	the IP address to look up.

Returns:

a pointer to a RouteRange class instance containing the relevant answer. It is up to the recipient of this pointer to free the associated memory.

Implements RouteTable< A >.

template<class A >

void MergedTable< A >::replumb	(	RouteTable< A > *	old_parent,
		RouteTable< A > *	new_parent
	)		[virtual]

replumb the parent tables, so that new_parent replaces old_parent.

Parameters:

old_parent	the old parent table.
new_parent	the new parent table.

Implements RouteTable< A >.

template<class A >

TableType MergedTable< A >::type

(

)

const [inline, virtual]

Returns:

the table type (TableType).

Implements RouteTable< A >.

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The documentation for this class was generated from the following files:

• /home/greearb/git/xorp.ct.github/xorp/rib/rt_tab_merged.hh
• /home/greearb/git/xorp.ct.github/xorp/rib/rt_tab_merged.cc