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36ad976b 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/dnsmaster.h" |
36ad976b CH |
24 | |
25 | #include <logfunc.hpp> | |
26 | #include <boost/bind.hpp> | |
36ad976b CH |
27 | #include <boost/asio/placeholders.hpp> |
28 | ||
c5b4902d CH |
29 | #include "dns/ippseudoresolver.h" |
30 | #include "dns/dnsresolver.h" | |
96779587 | 31 | |
36ad976b | 32 | using boost::bind; |
36ad976b CH |
33 | using I2n::Logger::GlobalLogger; |
34 | ||
96779587 | 35 | |
36ad976b CH |
36 | DnsMasterItem DnsMaster::TheOnlyInstance; |
37 | ||
8d26221d | 38 | // just delegates work to other create_master function |
96779587 | 39 | void DnsMaster::create_master(const IoServiceItem &io_serv, |
ad83004d CH |
40 | const boost::asio::ip::address &default_name_server, |
41 | const int resolved_ip_ttl_threshold, | |
42 | const int max_address_resolution_attempts, | |
43 | const std::string &cache_file) | |
36ad976b | 44 | { |
c1abff61 | 45 | GlobalLogger.info() << "DnsMaster: Creating cache"; |
8d26221d CH |
46 | DnsCacheItem cache( new DnsCache(io_serv, cache_file) ); |
47 | create_master(io_serv, default_name_server, resolved_ip_ttl_threshold, | |
48 | max_address_resolution_attempts, cache); | |
49 | } | |
50 | ||
51 | void DnsMaster::create_master(const IoServiceItem &io_serv, | |
52 | const boost::asio::ip::address &default_name_server, | |
53 | const int resolved_ip_ttl_threshold, | |
54 | const int max_address_resolution_attempts, | |
55 | const DnsCacheItem &cache) | |
56 | { | |
36ad976b CH |
57 | if (TheOnlyInstance) |
58 | { | |
c1abff61 CH |
59 | GlobalLogger.warning() << "DnsMaster: " |
60 | << "Blocking attempt to create another instance!"; | |
96779587 | 61 | return; |
36ad976b CH |
62 | } |
63 | ||
c1abff61 | 64 | GlobalLogger.info() << "DNS Master: creating instance"; |
923626c0 | 65 | TheOnlyInstance.reset( new DnsMaster(io_serv, |
ad83004d | 66 | default_name_server, |
923626c0 CH |
67 | resolved_ip_ttl_threshold, |
68 | max_address_resolution_attempts, | |
69 | cache) | |
70 | ); | |
36ad976b CH |
71 | } |
72 | ||
36ad976b | 73 | DnsMaster::DnsMaster(const IoServiceItem &io_serv, |
ad83004d | 74 | const boost::asio::ip::address &default_name_server, |
923626c0 CH |
75 | const int resolved_ip_ttl_threshold, |
76 | const int max_address_resolution_attempts, | |
96779587 | 77 | const DnsCacheItem &cache) |
36ad976b | 78 | : IoService( io_serv ) |
ad83004d | 79 | , DefaultNameServer( default_name_server ) |
923626c0 CH |
80 | , ResolvedIpTtlThreshold( resolved_ip_ttl_threshold ) |
81 | , MaxAddressResolutionAttempts( max_address_resolution_attempts ) | |
96779587 | 82 | , Cache(cache) |
4e7b6ff9 | 83 | , ResolverMap() |
36ad976b | 84 | { |
36ad976b CH |
85 | } |
86 | ||
87 | ||
88 | DnsMasterItem& DnsMaster::get_instance() | |
89 | { | |
90 | if ( !TheOnlyInstance ) | |
c1abff61 CH |
91 | GlobalLogger.error() << "DnsMaster: " |
92 | << "Request to return instance before creating it!"; | |
36ad976b CH |
93 | return TheOnlyInstance; |
94 | } | |
95 | ||
c5b4902d CH |
96 | DnsMaster::~DnsMaster() |
97 | { | |
c1abff61 | 98 | GlobalLogger.info() << "DnsMaster: being destructed"; |
c5b4902d CH |
99 | |
100 | if (DnsMaster::TheOnlyInstance) | |
26b0f687 CH |
101 | { // apparently, this static variable still exists while itself is |
102 | // destructed... | |
c1abff61 | 103 | //GlobalLogger.warning() << "DnsMaster: being destructed but not " |
26b0f687 | 104 | // << "singleton instance TheOnlyInstance!"; |
c5b4902d CH |
105 | DnsMaster::TheOnlyInstance.reset(); |
106 | } | |
107 | ||
108 | // Items in ResolverMap and the DnsCache might still be referenced by | |
109 | // Resolvers and are smart pointers, anyway --> nothing to do here | |
110 | } | |
111 | ||
36ad976b CH |
112 | |
113 | ||
923626c0 CH |
114 | ResolverItem& DnsMaster::get_resolver_for( const std::string &hostname, |
115 | const PingProtocol &ping_protocol ) | |
116 | { | |
117 | // find suitable DnsIpProtocol for ping protocol | |
dbe986b9 | 118 | DnsIpProtocol protocol = ping2dns_protocol(ping_protocol); |
923626c0 CH |
119 | return get_resolver_for(hostname, protocol); |
120 | } | |
121 | ||
122 | ||
ad83004d | 123 | ResolverItem& DnsMaster::get_resolver_for(const std::string &hostname, |
e18c1337 | 124 | const DnsIpProtocol &protocol) |
36ad976b | 125 | { |
923626c0 CH |
126 | // create key to ResolverMap |
127 | resolver_key_type key(hostname, protocol); | |
dbe986b9 | 128 | if ( ResolverMap.count(key) == 0 ) |
36ad976b CH |
129 | { // need to create a resolver |
130 | ||
131 | // check if it is an ip address, so can create a simple pseudo resolver | |
dbe986b9 | 132 | if ( is_ip(hostname) ) |
36ad976b | 133 | { |
923626c0 CH |
134 | boost::asio::ip::address ip |
135 | = boost::asio::ip::address::from_string(hostname); | |
136 | if ( (protocol == DNS_IPv4 && !ip.is_v4()) || | |
137 | (protocol == DNS_IPv6 && !ip.is_v6()) ) | |
c1abff61 CH |
138 | GlobalLogger.warning() << "DnsMaster:" |
139 | << "Asked to create a DNS resolver " | |
923626c0 CH |
140 | << "for wrong IP protocol: v4 != v6! " |
141 | << "We will comply."; | |
c1abff61 CH |
142 | GlobalLogger.info() << "DnsMaster: Creating PseudoResolver for IP " |
143 | << ip; | |
4e7b6ff9 CH |
144 | ResolverItem new_resolver( new IpPseudoResolver(IoService, |
145 | hostname, | |
146 | Cache) ); | |
dbe986b9 | 147 | ResolverMap[key] = new_resolver; |
36ad976b CH |
148 | } |
149 | else | |
150 | { | |
dbe986b9 CH |
151 | GlobalLogger.info() << "DnsMaster: Creating Resolver for host " |
152 | << hostname << " and protocol " << to_string(protocol); | |
4e7b6ff9 CH |
153 | ResolverItem new_resolver( new DnsResolver(IoService, |
154 | hostname, | |
923626c0 | 155 | protocol, |
4e7b6ff9 | 156 | Cache, |
ad83004d | 157 | DefaultNameServer) ); |
dbe986b9 | 158 | ResolverMap[key] = new_resolver; |
36ad976b CH |
159 | } |
160 | } | |
dbe986b9 | 161 | return ResolverMap[key]; |
36ad976b CH |
162 | } |
163 | ||
164 | /** | |
165 | * return true if given hostname string actually is an IP | |
166 | * | |
96779587 | 167 | * delegates decision to boost::asio::ip::address::from_string |
36ad976b CH |
168 | */ |
169 | bool DnsMaster::is_ip(const std::string &hostname) const | |
170 | { | |
171 | try | |
172 | { | |
96779587 CH |
173 | boost::asio::ip::address ip = boost::asio::ip::address::from_string( |
174 | hostname); | |
36ad976b CH |
175 | return ip.is_v4() || ip.is_v6(); |
176 | } | |
177 | catch ( const std::exception &ex ) | |
178 | { | |
179 | return false; | |
180 | } | |
181 | } | |
182 | ||
923626c0 CH |
183 | |
184 | DnsIpProtocol DnsMaster::ping2dns_protocol(const PingProtocol& pprot) | |
185 | { | |
186 | switch (pprot) | |
187 | { | |
188 | case PingProtocol_ICMP: return DNS_IPv4; break; | |
189 | case PingProtocol_ICMPv6: return DNS_IPv6; break; | |
190 | case PingProtocol_TCP: return DNS_IPv4; break; | |
191 | case PingProtocol_TCP_IPv6: return DNS_IPv6; break; | |
192 | default: | |
c1abff61 | 193 | GlobalLogger.warning() << "DnsMaster: Unexpected ping protocol: " |
923626c0 CH |
194 | << static_cast<int>(pprot); |
195 | return DNS_IPALL; | |
196 | break; | |
197 | } | |
198 | } | |
199 | ||
200 | /*boost::asio::ip::address &DnsMaster::get_name_server() const | |
201 | { | |
202 | return NameServer; | |
203 | }*/ | |
204 | ||
205 | int DnsMaster::get_resolved_ip_ttl_threshold() const | |
206 | { | |
207 | return ResolvedIpTtlThreshold; | |
208 | } | |
209 | ||
210 | int DnsMaster::get_max_address_resolution_attempts() const | |
96779587 | 211 | { |
923626c0 | 212 | return MaxAddressResolutionAttempts; |
96779587 CH |
213 | } |
214 | ||
e18c1337 CH |
215 | std::string to_string(const DnsIpProtocol &protocol) |
216 | { | |
217 | switch (protocol) | |
218 | { | |
219 | case DNS_IPv4: return "IPv4"; break; | |
220 | case DNS_IPv6: return "IPv6"; break; | |
221 | case DNS_IPALL: return "IPv4/6"; break; | |
222 | default: GlobalLogger.warning() << "Unexpected protocol in to_string!"; | |
223 | return "Unexpected Protocol"; break; | |
224 | } | |
225 | } |