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96779587 CH |
1 | /* |
2 | The software in this package is distributed under the GNU General | |
3 | Public License version 2 (with a special exception described below). | |
4 | ||
5 | A copy of GNU General Public License (GPL) is included in this distribution, | |
6 | in the file COPYING.GPL. | |
7 | ||
8 | As a special exception, if other files instantiate templates or use macros | |
9 | or inline functions from this file, or you compile this file and link it | |
10 | with other works to produce a work based on this file, this file | |
11 | does not by itself cause the resulting work to be covered | |
12 | by the GNU General Public License. | |
13 | ||
14 | However the source code for this file must still be made available | |
15 | in accordance with section (3) of the GNU General Public License. | |
16 | ||
17 | This exception does not invalidate any other reasons why a work based | |
18 | on this file might be covered by the GNU General Public License. | |
19 | ||
20 | Christian Herdtweck, Intra2net AG 2015 | |
21 | */ | |
22 | ||
c5b4902d | 23 | #include "dns/dnscache.h" |
96779587 | 24 | |
946356e1 | 25 | #include <fstream> |
96779587 | 26 | #include <logfunc.hpp> |
946356e1 | 27 | #include <filefunc.hxx> // I2n::file_exists |
e18c1337 | 28 | #include <boost/foreach.hpp> |
96779587 CH |
29 | #include <boost/bind.hpp> |
30 | #include <boost/date_time/posix_time/posix_time.hpp> | |
31 | #include <boost/asio/placeholders.hpp> | |
946356e1 CH |
32 | #include <boost/serialization/serialization.hpp> |
33 | #include <boost/serialization/map.hpp> | |
34 | #include <boost/serialization/string.hpp> | |
35 | #include <boost/serialization/vector.hpp> | |
36 | #include <boost/archive/xml_oarchive.hpp> | |
37 | #include <boost/archive/xml_iarchive.hpp> | |
96779587 CH |
38 | |
39 | using boost::bind; | |
40 | using boost::posix_time::seconds; | |
41 | using I2n::Logger::GlobalLogger; | |
42 | ||
43 | namespace Config | |
44 | { | |
45 | int SaveTimerSeconds = 60; | |
46 | } | |
47 | ||
48 | ||
49 | ||
50 | DnsCache::DnsCache(const IoServiceItem &io_serv, | |
51 | const std::string &cache_file) | |
ad83004d CH |
52 | : IpCache() |
53 | , CnameCache() | |
96779587 CH |
54 | , SaveTimer( *io_serv ) |
55 | , CacheFile( cache_file ) | |
56 | , HasChanged( false ) | |
57 | { | |
58 | // load cache from file | |
59 | load_from_cachefile(); | |
60 | ||
61 | // schedule next save | |
62 | (void) SaveTimer.expires_from_now( seconds( Config::SaveTimerSeconds ) ); | |
63 | SaveTimer.async_wait( bind( &DnsCache::schedule_save, this, | |
64 | boost::asio::placeholders::error ) ); | |
65 | } | |
66 | ||
67 | ||
68 | DnsCache::~DnsCache() | |
69 | { | |
e91538f0 CH |
70 | GlobalLogger.info() << "Dns Cache is being destructed"; |
71 | ||
96779587 CH |
72 | // save one last time without re-scheduling the next save |
73 | save_to_cachefile(); | |
74 | ||
75 | // cancel save timer | |
76 | SaveTimer.cancel(); | |
77 | } | |
78 | ||
79 | ||
80 | void DnsCache::schedule_save(const boost::system::error_code &error) | |
81 | { | |
82 | // just in case: ensure SaveTimer is cancelled | |
83 | SaveTimer.cancel(); // (will do nothing if already expired/cancelled) | |
84 | ||
85 | if ( error == boost::asio::error::operation_aborted ) // cancelled | |
86 | { | |
ad83004d | 87 | GlobalLogger.error() << "DnsCache: SaveTimer was cancelled " |
96779587 CH |
88 | << "--> no save and no re-schedule of saving!"; |
89 | return; | |
90 | } | |
91 | else if (error) | |
92 | { | |
ad83004d | 93 | GlobalLogger.error() << "DnsCache: Received error " << error |
96779587 CH |
94 | << " in schedule_save " |
95 | << "--> no save now but re-schedule saving"; | |
96 | } | |
97 | else | |
98 | save_to_cachefile(); | |
99 | ||
100 | // schedule next save | |
101 | (void) SaveTimer.expires_from_now( seconds( Config::SaveTimerSeconds ) ); | |
102 | SaveTimer.async_wait( bind( &DnsCache::schedule_save, this, | |
103 | boost::asio::placeholders::error ) ); | |
104 | } | |
105 | ||
106 | void DnsCache::save_to_cachefile() | |
107 | { | |
108 | if (!HasChanged) | |
109 | { | |
ad83004d | 110 | GlobalLogger.info() << "DnsCache: skip saving because has not changed"; |
96779587 CH |
111 | return; |
112 | } | |
946356e1 CH |
113 | else if (CacheFile.empty()) |
114 | { | |
115 | GlobalLogger.warning() | |
ad83004d | 116 | << "DnsCache: skip saving because file name empty!"; |
946356e1 CH |
117 | return; |
118 | } | |
96779587 | 119 | |
946356e1 CH |
120 | try |
121 | { | |
122 | std::ofstream ofs( CacheFile.c_str() ); | |
123 | boost::archive::xml_oarchive oa(ofs); | |
ad83004d CH |
124 | oa << boost::serialization::make_nvp("IpCache", IpCache); |
125 | oa << boost::serialization::make_nvp("CnameCache", CnameCache); | |
126 | GlobalLogger.info() << "DnsCache: saved to cache file " << CacheFile; | |
946356e1 CH |
127 | |
128 | HasChanged = false; | |
129 | } | |
130 | catch (std::exception &exc) | |
131 | { | |
132 | GlobalLogger.warning() << "Saving failed: " << exc.what(); | |
133 | } | |
96779587 CH |
134 | } |
135 | ||
136 | ||
137 | void DnsCache::load_from_cachefile() | |
138 | { | |
946356e1 CH |
139 | if (CacheFile.empty()) |
140 | { | |
141 | GlobalLogger.warning() | |
ad83004d | 142 | << "DnsCache: cannot load because cache file name is empty!"; |
946356e1 CH |
143 | return; |
144 | } | |
145 | else if ( !I2n::file_exists(CacheFile) ) | |
146 | { | |
ad83004d | 147 | GlobalLogger.warning() << "DnsCache: cannot load because cache file " |
946356e1 CH |
148 | << CacheFile << " does not exist!"; |
149 | return; | |
150 | } | |
151 | try | |
152 | { | |
153 | HostAddressVec cache; | |
154 | ||
155 | std::ifstream ifs( CacheFile.c_str() ); | |
156 | boost::archive::xml_iarchive ia(ifs); | |
157 | ||
ad83004d CH |
158 | ia >> boost::serialization::make_nvp("IpCache", cache); |
159 | ia >> boost::serialization::make_nvp("CnameCache", cache); | |
160 | GlobalLogger.info() << "DnsCache: loaded from file " << CacheFile; | |
946356e1 CH |
161 | } |
162 | catch (boost::archive::archive_exception &exc) | |
163 | { | |
ad83004d | 164 | GlobalLogger.warning() << "DnsCache: archive exception loading from " |
946356e1 CH |
165 | << CacheFile << ": " << exc.what(); |
166 | } | |
167 | catch (std::exception &exc) | |
168 | { | |
ad83004d | 169 | GlobalLogger.warning() << "DnsCache: exception while loading from " |
946356e1 CH |
170 | << CacheFile << ": " << exc.what(); |
171 | } | |
96779587 CH |
172 | } |
173 | ||
96779587 | 174 | void DnsCache::update(const std::string &hostname, |
4e7b6ff9 | 175 | const HostAddressVec &new_data) |
96779587 | 176 | { |
ad83004d | 177 | GlobalLogger.info() << "DnsCache: update IPs for " << hostname |
96779587 | 178 | << " to " << new_data.size() << "-list"; |
ad83004d | 179 | IpCache[hostname] = new_data; |
96779587 CH |
180 | HasChanged = true; |
181 | } | |
182 | ||
183 | ||
ad83004d CH |
184 | void DnsCache::update(const std::string &hostname, |
185 | const std::string &cname) | |
186 | { | |
187 | GlobalLogger.info() << "DnsCache: update CNAME for " << hostname | |
188 | << " to " << cname; | |
189 | CnameCache[hostname] = cname; | |
190 | HasChanged = true; | |
191 | } | |
192 | ||
193 | ||
194 | void DnsCache::update_ttl(const std::string &hostname, | |
195 | const uint32_t new_ttl) | |
196 | { | |
197 | GlobalLogger.info() << "DnsCache: ensure TTL for IPs for " << hostname | |
e18c1337 | 198 | << " is below " << new_ttl << "s"; |
ad83004d | 199 | HostAddressVec ips = IpCache[hostname]; |
ad83004d CH |
200 | TimeToLive current_ttl; |
201 | BOOST_FOREACH( HostAddress &addr, ips ) | |
202 | { | |
203 | current_ttl = addr.get_ttl(); | |
204 | if (current_ttl.get_value() > new_ttl) | |
205 | { | |
206 | current_ttl.set_value(new_ttl); | |
207 | addr.set_ttl(current_ttl); | |
208 | HasChanged = true; | |
209 | } | |
210 | } | |
e18c1337 | 211 | IpCache[hostname] = ips; |
ad83004d CH |
212 | } |
213 | ||
214 | ||
215 | HostAddressVec& DnsCache::get_ips(const std::string &hostname) | |
96779587 | 216 | { |
ad83004d CH |
217 | GlobalLogger.info() << "DnsCache: request IPs for " << hostname |
218 | << " --> " << IpCache[hostname].size() << "-list"; | |
219 | return IpCache[hostname]; | |
96779587 CH |
220 | } |
221 | ||
ad83004d CH |
222 | std::string& DnsCache::get_cname(const std::string &hostname) |
223 | { | |
224 | GlobalLogger.info() << "DnsCache: request CNAME for " << hostname | |
e18c1337 | 225 | << " --> \"" << CnameCache[hostname] << "\""; |
ad83004d CH |
226 | return CnameCache[hostname]; |
227 | } | |
228 | ||
e18c1337 CH |
229 | HostAddressVec& DnsCache::get_ips_recursive(const std::string &hostname) |
230 | { | |
231 | std::string current_host = hostname; | |
232 | HostAddressVec& result = get_ips(current_host); | |
233 | while ( result.empty() ) | |
234 | { | |
235 | current_host = get_cname(current_host); | |
236 | if (current_host.empty()) | |
237 | break; | |
238 | else | |
239 | result = get_ips(current_host); | |
240 | } | |
241 | return result; | |
242 | } | |
ad83004d | 243 | |
96779587 CH |
244 | // (created using vim -- the world's best text editor) |
245 |