Merge pull request #43 from CopernicaMarketingSoftware/split-authority

Share code between resolvers

Author: EmielBruijntjes

Makefile

@@ -2,8 +2,8 @@ PREFIX                  ?= /usr
 INCLUDE_DIR             = ${PREFIX}/include
 LIBRARY_DIR             = ${PREFIX}/lib
 export LIBRARY_NAME		= dnscpp
-export SONAME			= 1.3
-export VERSION			= 1.3.5
+export SONAME			= 1.4
+export VERSION			= 1.4.0
 
 all:
 		$(MAKE) -C src all

include/dnscpp/bits.h

@@ -26,6 +26,7 @@ namespace DNS {
  *      AD:     "please tell me if the data is verified (in case you know)"
  *      CD:     "checking-disabled: if you dont know if data is verified, just give me the data, no need to check it"
  *      DO:     "please also send relevant signatures like RSIG records"
+ *      RD:     "please do a recursive lookup if you do not hold the record yourself"
  * 
  *  When sent back in the response from the server to the client:
  * 

include/dnscpp/config.h

@@ -0,0 +1,238 @@
+/**
+ *  The configuration
+ * 
+ *  Object that holds the nameservers, loaded from /etc/resolv.conf and
+ *  the /etc/hosts file settings
+ *  
+ *  @author Emiel Bruijntjes <[email protected]>
+ *  @copyright 2025 Copernica BV
+ */
+
+/**
+ *  Begin of namespace
+ */
+namespace DNS {
+    
+/**
+ *  Class definition
+ */
+class Config
+{
+private:
+    /**
+     *  The IP addresses of the servers that can be accessed
+     *  @var std::vector<Ip>
+     */
+    std::vector<Ip> _nameservers;
+
+    /**
+     *  The IP addresses of the servers that can be accessed
+     *  @var std::vector<Ip>
+     */
+    std::vector<std::string> _searchpaths;
+    
+    /**
+     *  The contents of the /etc/hosts file
+     *  @var Hosts
+     */
+    Hosts _hosts;
+
+    /**
+     *  Max time that we wait for a response
+     *  @var double
+     */
+    double _timeout = 60.0;
+    
+    /**
+     *  Max number of attempts / requests to send per query
+     *  @var size_t
+     */
+    size_t _attempts = 5;
+
+    /**
+     *  Interval before a datagram is sent again
+     *  @var double
+     */
+    double _interval = 2.0;
+    
+    /**
+     *  Should all nameservers be rotated? otherwise they will be tried in-order
+     *  @var bool
+     */
+    bool _rotate = false;
+    
+    /**
+     *  The 'ndots' setting from resolv.conf
+     *  @var ndots
+     */
+    uint8_t _ndots = 1;
+
+
+public:
+    /**
+     *  Default constructor
+     */
+    Config() = default;
+
+    /**
+     *  Default constructor
+     *  @param  settings
+     */
+    Config(const ResolvConf &settings) :
+        _timeout(settings.timeout()),
+        _attempts(settings.attempts()),
+        _interval(settings.timeout()),
+        _rotate(settings.rotate()),
+        _ndots(settings.ndots())
+    {
+        // construct the nameservers and search paths
+        for (size_t i = 0; i < settings.nameservers(); ++i) _nameservers.emplace_back(settings.nameserver(i));
+        for (size_t i = 0; i < settings.searchpaths(); ++i) _searchpaths.emplace_back(settings.searchpath(i));
+
+        // we also have to load /etc/hosts
+        if (!_hosts.load()) throw std::runtime_error("failed to load /etc/hosts");
+    }
+
+    /**
+     *  Expose the /etc/hosts file
+     *  @return Hosts
+     */
+    const Hosts &hosts() const
+    {
+        return _hosts;
+    }
+
+    /**
+     *  Clear the list of nameservers
+     */
+    void clear()
+    {
+        // empty the list
+        _nameservers.clear();
+    }
+
+    /**
+     *  Add a nameserver
+     *  @param  ip
+     */
+    void nameserver(const Ip &ip)
+    {
+        // add to the member in the base class
+        _nameservers.emplace_back(ip);
+    }
+
+    /**
+     *  Total number of nameservers
+     *  @return size_t
+     */
+    size_t nameservers() const
+    {
+        return _nameservers.size();
+    }
+
+    /**
+     *  Expose to one of the nameservers
+     *  @param  index
+     *  @return Ip
+     */
+    const Ip &nameserver(size_t index) const 
+    { 
+        return _nameservers[index];
+    }
+
+    /**
+     *  The total number of searchpaths
+     *  @return size_t
+     */
+    size_t searchpaths() const
+    {
+        return _searchpaths.size();
+    }
+
+    /**
+     *  Expose one of the search-paths
+     *  @param  index
+     *  @return std::string
+     */
+    const std::string &searchpath(size_t index) const
+    { 
+        return _searchpaths[index];
+    }
+
+    /**
+     *  Does a certain hostname exists in /etc/hosts? In that case a NXDOMAIN error should not be given
+     *  @param  hostname        hostname to check
+     *  @return bool            does it exists in /etc/hosts?
+     */
+    bool exists(const char *hostname) const
+    { 
+        // lookup the name
+        return _hosts.lookup(hostname) != nullptr;
+    }
+
+    /**
+     *  Max time that we wait for a response
+     *  @return double
+     */
+    double timeout() const { return _timeout; }
+
+    /**
+     *  Set max time to wait for a response
+     *  @param timeout      time in seconds
+     */
+    void timeout(double timeout) { _timeout = std::max(timeout, 0.1); }
+    
+    /**
+     *  Max number of attempts / requests to send per query
+     *  @return size_t
+     */
+    size_t attempts() const { return _attempts; }
+
+    /**
+     *  Set the max number of attempts
+     *  @param  attempt     max number of attemps
+     */
+    void attempts(size_t attempts) { _attempts = attempts; }
+
+    /**
+     *  Interval before a datagram is sent again
+     *  @return double
+     */
+    double interval() const { return _interval; }
+
+    /**
+     *  Set interval before a datagram is sent again
+     *  @param  interval    time in seconds
+     */
+    void interval(double interval) { _interval = std::max(interval, 0.1); }
+    
+    /**
+     *  Should all nameservers be rotated? otherwise they will be tried in-order
+     *  @return bool
+     */
+    bool rotate() const { return _rotate; }
+
+    /**
+     *  Set the rotate setting: If true, nameservers will be rotated, if false, nameservers are tried in-order
+     *  @param rotate   the new setting
+     */
+    void rotate(bool rotate) { _rotate = rotate; }
+    
+    /**
+     *  The 'ndots' setting from resolv.conf
+     *  @return ndots
+     */
+    uint8_t ndots() const { return _ndots; }
+
+    /**
+     *  Change the ndots setting
+     *  @param  value       the new value
+     */
+    void ndots(uint8_t value) { _ndots = value; }
+};
+
+/**
+ *  End of namespace
+ */
+}
+