blob: 61a79c0c4866260e2db2ec0bf29fc0ce5bdee47a (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
|
// Copyright (C) 2016 Internet Systems Consortium, Inc. ("ISC")
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
/**
@page dhcpv4o6Dhcp6 DHCPv4-over-DHCPv6 DHCPv6 Server Side
Kea supports DHCPv4-over-DHCPv6 using cooperating DHCPv6 and DHCPv4
servers. This section describes the DHCPv6 server side. For its
DHCPv6 counter-part, see @ref dhcpv4o6Dhcp4.
@section dhcp6to4Ipc DHCPv6-to-DHCPv4 Inter Process Communication
The @c Dhcp6to4Ipc class is derived from the base @c Dhcp4o6IpcBase as
a singleton class (by the static @ref isc::dhcp::Dhcp6to4Ipc::instance
function). @ref isc::dhcp::Dhcp6to4Ipc::open is called to open IPC
UDP sockets and to register @ref isc::dhcp::Dhcp6to4Ipc::handler on
external sockets on the @c IfaceMgr.
@section dhcp6to4Process DHCPv6-to-DHCPv4 Packet Processing
Following the DHCPv4-over-DHCPv6 packet flow:
- a DHCPv6 DHCPv4-QUERY is received from a DHCPv4-over-DHCPv6 client
(standard incoming DHCPv6 message processing is done until
the message type specific part)
- the isc::dhcp::Dhcpv6Srv::processDhcp4Query method which verifies
a DHCPv4 message option is present and calls the (inherited) @ref
isc::dhcp::Dhcp4o6IpcBase::send method to transmit the DHCPv4-QUERY
with the interface name and remote IPv6 address to the DHCPv4 server
- the DHCPv4 server processes the DHCPv4-QUERY and returns a
DHCPv4-RESPONSE using the IPC
- the interface manager (@c IfaceMgr) using the external socket
mechanism invokes @ref isc::dhcp::Dhcp6to4Ipc::handler
- @ref isc::dhcp::Dhcp6to4Ipc::handler receives the packet by
(inherited) @ref isc::dhcp::Dhcp4o6IpcBase::receive which
decodes and strips the ISC Vendor option. From this point
the code mimics the sending part of standard DHCPv6 packet
processing.
- the callouts registered for "buffer6_send" hook point are called
(@ref dhcpv6HooksBuffer6Send). Note the "pkt6_send" hook is not used
because the matching query packet is not available
- the DHCPv6 DHCPv4-RESPONSE packet is sent back to the IPv6 remote address
*/
|
