Mostly corrections additions to commentary.
specific subnet. Kea will still match inbound client packets to a
subnet as before, but when the subnet's reservation mode is set to
<command>"global"</command>, Kea will look for host reservations only
- among the global reservations defined. Typcially, such resrvations would
+ among the global reservations defined. Typcially, such reservations would
be used to reserve hostnames for clients which may move from one subnet
to another.
</para>
<para>This feature can be used to assign certain parameters, such as
hostname or other dedicated, host-specific options. It can also be used to
- assign addresses or prefixes. However, global reservations that assign
- either of these bypass the whole topology determination provided by DHCP
- logic implemented in Kea. It is very easy to misuse this feature and get
- configuration that is inconsistent. To give a specific example, imagine a
- global reservation for an address 2001:db8:1111::1 and two subnets
- 2001:db8:1111::/64 and 2001:db8:ffff::/48. If global reservations are used
- in both subnets and a device matching global host reservations visits part
- of the network that is covered by 2001:db8:ffff::/48, it will get an IP
- address 2001:db8:ffff::/48, which will be outside of the prefix announced
+ assign addresses or prefixes. However, global reservations that assign
+ either of these bypass the whole topology determination provided by DHCP
+ logic implemented in Kea. It is very easy to misuse this feature and get
+ configuration that is inconsistent. To give a specific example, imagine a
+ global reservation for an address 2001:db8:1111::1 and two subnets
+ 2001:db8:1111::/48 and 2001:db8:ffff::/48. If global reservations are used
+ in both subnets and a device matching global host reservations visits part
+ of the network that is covered by 2001:db8:ffff::/48, it will get an IP
+ address 2001:db8:ffff::1, which will be outside of the prefix announced
by its local router using Router Advertisements. Such a configuration
- would be unsuable or at the very least ridden with issues, such as the
+ would be unsuable or at the very least ridden with issues, such as the
downlink traffic not reaching the device.</para>
<para>
"hostname": "hw-host-fixed",
// Use of IP address is global reservation is risky. If used outside of
- // matching subnet, such as 2001:db8:1::/64, it will result in a broken
+ // matching subnet, such as 3001::/64, it will result in a broken
// configuration being handled to the client.
"ip-address": "2001:db8:ff::77"
},
Lease6 lease_client = client.getLease(0);
EXPECT_EQ(exp_address, lease_client.addr_.toText());
- // Check that the server recorded the lease.
- // and that the server lease has NO hostname
+ // Check that the server recorded the lease
+ // and that the server lease has expected hostname.
Lease6Ptr lease_server = checkLease(lease_client);
ASSERT_TRUE(lease_server);
EXPECT_EQ(exp_hostname, lease_server->hostname_);
return (false);
}
- // We want to avoid allocating new lease for an IA if there is already
+ // We want to avoid allocating a new lease for an IA if there is already
// a valid lease for which client has reservation. So, we first check if
// we already have a lease for a reserved address or prefix.
BOOST_FOREACH(const Lease6Ptr& lease, existing_leases) {
.arg(lease->typeToText(lease->type_))
.arg(lease->addr_.toText());
+ // Besides IP reservations we're also going to return other reserved
// parameters, such as hostname. We want to hand out the hostname value
// from the same reservation entry as IP addresses. Thus, let's see if
// there is any hostname reservation.
///
/// If the current subnet's reservation mode is global and
/// there is a global host (i.e. reservation belonging to
- /// the global subnet), return it. Otherwise return an
+ /// the global subnet), return it. Otherwise return an
/// empty pointer.
///
/// @return Pointer to the host object.
if (lease.type_ == Lease::TYPE_NA) {
return (IPv6Resrv(IPv6Resrv::TYPE_NA, lease.addr_,
(lease.prefixlen_ ? lease.prefixlen_ : 128)));
- }
+ }
return (IPv6Resrv(IPv6Resrv::TYPE_PD, lease.addr_, lease.prefixlen_));
}
/// @brief Creates new leases based on reservations.
///
- /// This method allocates new leases, based on host reservation. Existing
- /// leases are specified in existing_leases parameter. A new lease is not created,
- /// if there is a lease for specified address on existing_leases list or there is
- /// a lease used by someone else.
+ /// This method allcoates new leases, based on host reservations.
+ /// Existing leases are specified in the existing_leases parameter.
+ /// It first calls @c allocateGlobalReservedLeases6 to accomodate
+ /// subnets using global reservations. If that method allocates
+ /// addresses, we return, otherwise we continue and check for non-global
+ /// reservations. A new lease is not created, if there is a lease for
+ /// specified address on existing_leases list or there is a lease used by
+ /// someone else.
///
/// @param ctx client context that contains all details (subnet, client-id, etc.)
/// @param existing_leases leases that are already associated with the client
void
allocateReservedLeases6(ClientContext6& ctx, Lease6Collection& existing_leases);
+ /// @brief Creates new leases based on global reservations.
+ ///
+ /// This method is used by @allocateReservedLeases6, to allocate new leases based
+ /// on global reservation if one exists and global reservations are enabled for
+ /// the selected subnet. It differs from it's caller by looking only at the global
+ /// reservation and therefore has no need to iterate over the selected subnet or it's
+ /// siblings looking for host reservations. Like it's caller, existing leases are
+ /// specified in existing_leases parameter. A new lease is not created, if there is
+ /// a lease for specified address on existing_leases list or there is a lease used by
+ /// someone else.
+ ///
+ /// @param ctx client context that contains all details (subnet, client-id, etc.)
+ /// @param existing_leases leases that are already associated with the client
bool
allocateGlobalReservedLeases6(ClientContext6& ctx, Lease6Collection& existing_leases);
projects / thirdparty / kea.git / commitdiff
