| 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 | |
| 23 | #include "dns/resolverbase.h" |
| 24 | #include "dns/dnsmaster.h" |
| 25 | |
| 26 | #include <boost/bind.hpp> |
| 27 | |
| 28 | #include <logfunc.hpp> |
| 29 | |
| 30 | using I2n::Logger::GlobalLogger; |
| 31 | |
| 32 | |
| 33 | ResolverBase::~ResolverBase() |
| 34 | { } |
| 35 | |
| 36 | /** |
| 37 | * callbacks should be of type |
| 38 | * void resolve_callback(const bool was_success, |
| 39 | * const int recursion_count) |
| 40 | */ |
| 41 | void ResolverBase::async_resolve(const callback_type &callback, |
| 42 | const int recursion_count) |
| 43 | { |
| 44 | // limit depth of recursion |
| 45 | if (recursion_count >= DnsMaster::get_instance()->get_max_recursion_count()) |
| 46 | { // if recursed too much, schedule callback with was_success = false |
| 47 | bool was_success = false; |
| 48 | IoService->post( boost::bind(callback, was_success, recursion_count) ); |
| 49 | } |
| 50 | else |
| 51 | { |
| 52 | // remember callback |
| 53 | CallbackList.push(callback); |
| 54 | |
| 55 | // check for trouble |
| 56 | if (CallbackList.size() > 10) |
| 57 | GlobalLogger.warning() << "ResolverBase: have " |
| 58 | << CallbackList.size() << " callback[s] listed for " << Hostname |
| 59 | << "!"; |
| 60 | |
| 61 | // let subclass do the resolving |
| 62 | do_resolve(recursion_count); |
| 63 | } |
| 64 | |
| 65 | } |
| 66 | |
| 67 | ResolverBase::ResolverBase(const IoServiceItem &io_serv, |
| 68 | const std::string &hostname, |
| 69 | const DnsIpProtocol &protocol, |
| 70 | const DnsCacheItem &cache ) |
| 71 | : IoService( io_serv ) |
| 72 | , Hostname( hostname ) |
| 73 | , Protocol( protocol ) |
| 74 | , Cache( cache ) |
| 75 | , CallbackList() |
| 76 | {} |
| 77 | |
| 78 | std::string ResolverBase::get_hostname() const |
| 79 | { return Hostname; } |
| 80 | |
| 81 | std::string ResolverBase::get_skip_cname() const |
| 82 | { |
| 83 | DnsMasterItem master = DnsMaster::get_instance(); |
| 84 | std::string first_out_of_date = Cache->get_first_outdated_cname( |
| 85 | Hostname, |
| 86 | master->get_resolved_ip_ttl_threshold() ); |
| 87 | if ( first_out_of_date == Hostname ) |
| 88 | return ""; |
| 89 | else |
| 90 | return first_out_of_date; |
| 91 | } |
| 92 | |
| 93 | void ResolverBase::update_cache( const std::string &hostname, |
| 94 | const HostAddressVec &new_ips ) const |
| 95 | { Cache->update( hostname, Protocol, new_ips ); } |
| 96 | |
| 97 | void ResolverBase::update_cache( const std::string &hostname, |
| 98 | const Cname &cname ) const |
| 99 | { Cache->update( hostname, cname ); } |
| 100 | |
| 101 | void ResolverBase::update_cache( const HostAddressVec &new_ips ) const |
| 102 | { Cache->update( Hostname, Protocol, new_ips ); } |
| 103 | |
| 104 | void ResolverBase::update_cache( const Cname &cname ) const |
| 105 | { Cache->update( Hostname, cname ); } |
| 106 | |
| 107 | |
| 108 | /** |
| 109 | * @brief get IPs like a "real" resolver, i.e. recursively going through CNAMEs |
| 110 | * |
| 111 | * if host is empty, will use this Resolver's Hostname and Protocol |
| 112 | * |
| 113 | * just calls DnsCache::get_ips_recursive |
| 114 | */ |
| 115 | HostAddressVec ResolverBase::get_cached_ips_recursively(const std::string host, |
| 116 | bool check_up_to_date) const |
| 117 | { |
| 118 | if (host.empty()) |
| 119 | return Cache->get_ips_recursive(Hostname, Protocol, check_up_to_date); |
| 120 | else |
| 121 | return Cache->get_ips_recursive(host, Protocol, check_up_to_date); |
| 122 | } |
| 123 | |
| 124 | void ResolverBase::schedule_callbacks(const bool was_success, |
| 125 | const int recursion_count) |
| 126 | { |
| 127 | while ( !CallbackList.empty() ) |
| 128 | { |
| 129 | callback_type callback = CallbackList.front(); |
| 130 | CallbackList.pop(); |
| 131 | IoService->post( boost::bind(callback, was_success, recursion_count) ); |
| 132 | } |
| 133 | } |
| 134 | |