1 // Copyright (C) 2012-2021 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 #include <asiolink/io_address.h>
9 #include <dhcp/iface_mgr.h>
10 #include <dhcp/libdhcp++.h>
11 #include <dhcpsrv/cfgmgr.h>
12 #include <dhcpsrv/dhcpsrv_log.h>
13 #include <sstream>
14 #include <string>
15
16 using namespace isc::asiolink;
17 using namespace isc::util;
18
19 namespace isc {
20 namespace dhcp {
21
22 const size_t CfgMgr::CONFIG_LIST_SIZE = 10;
23
24 CfgMgr&
instance()25 CfgMgr::instance() {
26 static CfgMgr cfg_mgr;
27 return (cfg_mgr);
28 }
29
30 Optional<std::string>
getDataDir() const31 CfgMgr::getDataDir() const {
32 return (datadir_);
33 }
34
35 void
setDataDir(const std::string & datadir,bool unspecified)36 CfgMgr::setDataDir(const std::string& datadir, bool unspecified) {
37 datadir_ = Optional<std::string>(datadir, unspecified);
38 }
39
40 void
setD2ClientConfig(D2ClientConfigPtr & new_config)41 CfgMgr::setD2ClientConfig(D2ClientConfigPtr& new_config) {
42 ensureCurrentAllocated();
43 // Note that D2ClientMgr::setD2Config() actually attempts to apply the
44 // configuration by stopping its sender and opening a new one and so
45 // forth per the new configuration.
46 d2_client_mgr_.setD2ClientConfig(new_config);
47
48 // Manager will throw if the set fails, if it succeeds
49 // we'll update our SrvConfig, configuration_, with the D2ClientConfig
50 // used. This is largely bookkeeping in case we ever want to compare
51 // configuration_ to another SrvConfig.
52 configuration_->setD2ClientConfig(new_config);
53 }
54
55 bool
ddnsEnabled()56 CfgMgr::ddnsEnabled() {
57 return (d2_client_mgr_.ddnsEnabled());
58 }
59
60 const D2ClientConfigPtr&
getD2ClientConfig() const61 CfgMgr::getD2ClientConfig() const {
62 return (d2_client_mgr_.getD2ClientConfig());
63 }
64
65 D2ClientMgr&
getD2ClientMgr()66 CfgMgr::getD2ClientMgr() {
67 return (d2_client_mgr_);
68 }
69
70 void
ensureCurrentAllocated()71 CfgMgr::ensureCurrentAllocated() {
72 if (!configuration_ || configs_.empty()) {
73 configuration_.reset(new SrvConfig());
74 configs_.push_back(configuration_);
75 }
76 }
77
78 void
clear()79 CfgMgr::clear() {
80 if (configuration_) {
81 configuration_->removeStatistics();
82 }
83 configs_.clear();
84 external_configs_.clear();
85 D2ClientConfigPtr d2_default_conf(new D2ClientConfig());
86 setD2ClientConfig(d2_default_conf);
87 }
88
89 void
commit()90 CfgMgr::commit() {
91 ensureCurrentAllocated();
92
93 // First we need to remove statistics. The new configuration can have fewer
94 // subnets. Also, it may change subnet-ids. So we need to remove them all
95 // and add it back.
96 configuration_->removeStatistics();
97
98 if (!configs_.back()->sequenceEquals(*configuration_)) {
99 configuration_ = configs_.back();
100 // Keep track of the maximum size of the configs history. Before adding
101 // new element, we have to remove the oldest one.
102 if (configs_.size() > CONFIG_LIST_SIZE) {
103 SrvConfigList::iterator it = configs_.begin();
104 std::advance(it, configs_.size() - CONFIG_LIST_SIZE);
105 configs_.erase(configs_.begin(), it);
106 }
107 }
108
109 // Set the last commit timestamp.
110 auto now = boost::posix_time::second_clock::universal_time();
111 configuration_->setLastCommitTime(now);
112
113 // Now we need to set the statistics back.
114 configuration_->updateStatistics();
115
116 configuration_->configureLowerLevelLibraries();
117 }
118
119 void
rollback()120 CfgMgr::rollback() {
121 ensureCurrentAllocated();
122 if (!configuration_->sequenceEquals(*configs_.back())) {
123 configs_.pop_back();
124 }
125 }
126
127 void
revert(const size_t index)128 CfgMgr::revert(const size_t index) {
129 ensureCurrentAllocated();
130 if (index == 0) {
131 isc_throw(isc::OutOfRange, "invalid commit index 0 when reverting"
132 " to an old configuration");
133 } else if (index > configs_.size() - 1) {
134 isc_throw(isc::OutOfRange, "unable to revert to commit index '"
135 << index << "', only '" << configs_.size() - 1
136 << "' previous commits available");
137 }
138
139 // Let's rollback an existing configuration to make sure that the last
140 // configuration on the list is the current one. Note that all remaining
141 // operations in this function should be exception free so there shouldn't
142 // be a problem that the revert operation fails and the staging
143 // configuration is destroyed by this rollback.
144 rollback();
145
146 // Get the iterator to the current configuration and then advance to the
147 // desired one.
148 SrvConfigList::const_reverse_iterator it = configs_.rbegin();
149 std::advance(it, index);
150
151 // Copy the desired configuration to the new staging configuration. The
152 // staging configuration is re-created here because we rolled back earlier
153 // in this function.
154 (*it)->copy(*getStagingCfg());
155
156 // Make the staging configuration a current one.
157 commit();
158 }
159
160 SrvConfigPtr
getCurrentCfg()161 CfgMgr::getCurrentCfg() {
162 ensureCurrentAllocated();
163 return (configuration_);
164 }
165
166 SrvConfigPtr
getStagingCfg()167 CfgMgr::getStagingCfg() {
168 ensureCurrentAllocated();
169 if (configuration_->sequenceEquals(*configs_.back())) {
170 uint32_t sequence = configuration_->getSequence();
171 configs_.push_back(SrvConfigPtr(new SrvConfig(++sequence)));
172 }
173 return (configs_.back());
174 }
175
176 SrvConfigPtr
createExternalCfg()177 CfgMgr::createExternalCfg() {
178 uint32_t seq = 0;
179
180 if (!external_configs_.empty()) {
181 seq = external_configs_.rbegin()->second->getSequence() + 1;
182 }
183
184 SrvConfigPtr srv_config(new SrvConfig(seq));
185 external_configs_[seq] = srv_config;
186 return (srv_config);
187 }
188
189 void
mergeIntoStagingCfg(const uint32_t seq)190 CfgMgr::mergeIntoStagingCfg(const uint32_t seq) {
191 mergeIntoCfg(getStagingCfg(), seq);
192 }
193
194 void
mergeIntoCurrentCfg(const uint32_t seq)195 CfgMgr::mergeIntoCurrentCfg(const uint32_t seq) {
196 try {
197 // First we need to remove statistics.
198 getCurrentCfg()->removeStatistics();
199 mergeIntoCfg(getCurrentCfg(), seq);
200
201 } catch (...) {
202 // Make sure the statistics is updated even if the merge failed.
203 getCurrentCfg()->updateStatistics();
204 throw;
205 }
206 getCurrentCfg()->updateStatistics();
207 }
208
209 void
mergeIntoCfg(const SrvConfigPtr & target_config,const uint32_t seq)210 CfgMgr::mergeIntoCfg(const SrvConfigPtr& target_config, const uint32_t seq) {
211 auto source_config = external_configs_.find(seq);
212 if (source_config != external_configs_.end()) {
213 target_config->merge(*source_config->second);
214 external_configs_.erase(source_config);
215
216 } else {
217 isc_throw(BadValue, "the external configuration with the sequence number "
218 "of " << seq << " was not found");
219 }
220 }
221
CfgMgr()222 CfgMgr::CfgMgr()
223 : datadir_(DHCP_DATA_DIR, true), d2_client_mgr_(), family_(AF_INET) {
224 // DHCP_DATA_DIR must be set set with -DDHCP_DATA_DIR="..." in Makefile.am
225 // Note: the definition of DHCP_DATA_DIR needs to include quotation marks
226 // See AM_CPPFLAGS definition in Makefile.am
227 }
228
~CfgMgr()229 CfgMgr::~CfgMgr() {
230 }
231
232 } // end of isc::dhcp namespace
233 } // end of isc namespace
234