Kea 2.4.1
ncr_generator.cc
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1// Copyright (C) 2015-2023 Internet Systems Consortium, Inc. ("ISC")
2//
3// This Source Code Form is subject to the terms of the Mozilla Public
4// License, v. 2.0. If a copy of the MPL was not distributed with this
5// file, You can obtain one at http://mozilla.org/MPL/2.0/.
6
7#include <config.h>
8
10#include <dhcpsrv/cfgmgr.h>
11#include <dhcpsrv/dhcpsrv_log.h>
14#include <stdint.h>
15#include <vector>
16
17using namespace isc;
18using namespace isc::dhcp;
19using namespace isc::dhcp_ddns;
20
21namespace {
22
38template<typename LeasePtrType, typename IdentifierType>
39void queueNCRCommon(const NameChangeType& chg_type, const LeasePtrType& lease,
40 const IdentifierType& identifier, const std::string& label,
41 NetworkPtr subnet) {
42 // Check if there is a need for update.
43 if (lease->hostname_.empty() || (!lease->fqdn_fwd_ && !lease->fqdn_rev_)
47 .arg(label)
48 .arg(lease->addr_.toText());
49
50 return;
51 }
52
53 bool use_conflict_resolution = true;
54 util::Optional<double> ddns_ttl_percent;
55 if (subnet) {
56 use_conflict_resolution = subnet->getDdnsUseConflictResolution();
57 ddns_ttl_percent = subnet->getDdnsTtlPercent();
58 }
59
60 try {
61 // Create DHCID
62 std::vector<uint8_t> hostname_wire;
63 OptionDataTypeUtil::writeFqdn(lease->hostname_, hostname_wire, true);
64 D2Dhcid dhcid = D2Dhcid(identifier, hostname_wire);
65
66 // Calculate the TTL based on lease life time.
67 uint32_t ttl = calculateDdnsTtl(lease->valid_lft_, ddns_ttl_percent);
68
69 // Create name change request.
71 (new NameChangeRequest(chg_type, lease->fqdn_fwd_, lease->fqdn_rev_,
72 lease->hostname_, lease->addr_.toText(),
73 dhcid, lease->cltt_ + ttl,
74 ttl, use_conflict_resolution));
75
77 .arg(label)
78 .arg(chg_type == CHG_ADD ? "add" : "remove")
79 .arg(ncr->toText());
80
81 // Send name change request.
83
84 } catch (const std::exception& ex) {
86 .arg(label)
87 .arg(chg_type == CHG_ADD ? "add" : "remove")
88 .arg(lease->addr_.toText())
89 .arg(ex.what());
90 }
91}
92
93} // end of anonymous namespace
94
95namespace isc {
96namespace dhcp {
97
98void queueNCR(const NameChangeType& chg_type, const Lease4Ptr& lease) {
99 if (lease) {
100 // Figure out from the lease's subnet if we should use conflict resolution.
101 // If there's no subnet, something hinky is going on so we'll set it true.
103 ->getCfgSubnets4()->getSubnet(lease->subnet_id_);
104
105 // Client id takes precedence over HW address.
106 if (lease->client_id_) {
107 queueNCRCommon(chg_type, lease, lease->client_id_->getClientId(),
108 Pkt4::makeLabel(lease->hwaddr_, lease->client_id_), subnet);
109 } else {
110 // Client id is not specified for the lease. Use HW address
111 // instead.
112 queueNCRCommon(chg_type, lease, lease->hwaddr_,
113 Pkt4::makeLabel(lease->hwaddr_, lease->client_id_), subnet);
114 }
115 }
116}
117
118void queueNCR(const NameChangeType& chg_type, const Lease6Ptr& lease) {
119 // DUID is required to generate NCR.
120 if (lease && (lease->type_ != Lease::TYPE_PD) && lease->duid_) {
121 // Figure out from the lease's subnet if we should use conflict resolution.
122 // If there's no subnet, something hinky is going on so we'll set it true.
124 ->getCfgSubnets6()->getSubnet(lease->subnet_id_);
125 queueNCRCommon(chg_type, lease, *(lease->duid_),
126 Pkt6::makeLabel(lease->duid_, lease->hwaddr_), subnet);
127 }
128}
129
130uint32_t calculateDdnsTtl(uint32_t lease_lft, const util::Optional<double>& ddns_ttl_percent) {
131 // If we have a configured percentage use it to calculate TTL.
132 if (!ddns_ttl_percent.unspecified() && (ddns_ttl_percent.get() > 0.0)) {
133 uint32_t new_lft = static_cast<uint32_t>(round(ddns_ttl_percent.get() * lease_lft));
134 if (new_lft > 0) {
135 return (new_lft);
136 } else {
139 .arg(ddns_ttl_percent.get())
140 .arg(lease_lft);
141 }
142 }
143
144 // Per RFC 4702 DDNS RR TTL should be given by:
145 // ((lease life time / 3) < 10 minutes) ? 10 minutes : (lease life time / 3)
146 if (lease_lft < 1800) {
147 return (600);
148 }
149
150 return (lease_lft / 3);
151}
152
153}
154}
D2ClientMgr & getD2ClientMgr()
Fetches the DHCP-DDNS manager.
Definition cfgmgr.cc:66
static CfgMgr & instance()
returns a single instance of Configuration Manager
Definition cfgmgr.cc:25
SrvConfigPtr getCurrentCfg()
Returns a pointer to the current configuration.
Definition cfgmgr.cc:161
bool ddnsEnabled()
Convenience method for checking if DHCP-DDNS is enabled.
void sendRequest(dhcp_ddns::NameChangeRequestPtr &ncr)
Send the given NameChangeRequests to kea-dhcp-ddns.
static void writeFqdn(const std::string &fqdn, std::vector< uint8_t > &buf, const bool downcase=false)
Append FQDN into a buffer.
static std::string makeLabel(const HWAddrPtr &hwaddr, const ClientIdPtr &client_id, const uint32_t transid)
Returns text representation of the given packet identifiers.
Definition pkt4.cc:405
static std::string makeLabel(const DuidPtr duid, const uint32_t transid, const HWAddrPtr &hwaddr)
Returns text representation of the given packet identifiers.
Definition pkt6.cc:695
Container class for handling the DHCID value within a NameChangeRequest.
Definition ncr_msg.h:86
Represents a DHCP-DDNS client request.
Definition ncr_msg.h:227
A template representing an optional value.
Definition optional.h:36
T get() const
Retrieves the encapsulated value.
Definition optional.h:114
void unspecified(bool unspecified)
Modifies the flag that indicates whether the value is specified or unspecified.
Definition optional.h:136
Defines the D2ClientMgr class.
#define LOG_ERROR(LOGGER, MESSAGE)
Macro to conveniently test error output and log it.
Definition macros.h:32
#define LOG_DEBUG(LOGGER, LEVEL, MESSAGE)
Macro to conveniently test debug output and log it.
Definition macros.h:14
boost::shared_ptr< NameChangeRequest > NameChangeRequestPtr
Defines a pointer to a NameChangeRequest.
Definition ncr_msg.h:214
NameChangeType
Defines the types of DNS updates that can be requested.
Definition ncr_msg.h:46
const int DHCPSRV_DBG_TRACE_DETAIL_DATA
Additional information.
Definition dhcpsrv_log.h:43
isc::log::Logger dhcpsrv_logger("dhcpsrv")
DHCP server library Logger.
Definition dhcpsrv_log.h:56
uint32_t calculateDdnsTtl(uint32_t lease_lft, const util::Optional< double > &ddns_ttl_percent)
Calculates TTL for a DNS resource record based on lease life time.
boost::shared_ptr< Subnet4 > Subnet4Ptr
A pointer to a Subnet4 object.
Definition subnet.h:498
const isc::log::MessageID DHCPSRV_QUEUE_NCR
void queueNCR(const NameChangeType &chg_type, const Lease4Ptr &lease)
Creates name change request from the DHCPv4 lease.
boost::shared_ptr< Lease6 > Lease6Ptr
Pointer to a Lease6 structure.
Definition lease.h:505
boost::shared_ptr< Subnet6 > Subnet6Ptr
A pointer to a Subnet6 object.
Definition subnet.h:663
const isc::log::MessageID DHCPSRV_QUEUE_NCR_FAILED
const int DHCPSRV_DBG_TRACE_DETAIL
Additional information.
Definition dhcpsrv_log.h:38
const isc::log::MessageID DHCPSRV_DDNS_TTL_PERCENT_TOO_SMALL
const isc::log::MessageID DHCPSRV_QUEUE_NCR_SKIP
boost::shared_ptr< Network > NetworkPtr
Pointer to the Network object.
Definition network.h:73
boost::shared_ptr< Lease4 > Lease4Ptr
Pointer to a Lease4 structure.
Definition lease.h:292
Defines the logger used by the top-level component of kea-lfc.
@ TYPE_PD
the lease contains IPv6 prefix (for prefix delegation)
Definition lease.h:49