Add specialization for ConvToStr on a single char, return std::string(in,1) :p

[user/henk/code/inspircd.git] / include / dns.h

diff --git a/include/dns.h b/include/dns.h
index 92f3fe8f7e13fef9496ed68e270e466b48a39666..562a493221c23eb91a6d92206a8c8f594058f646 100644 (file)
--- a/include/dns.h
+++ b/include/dns.h
@@ -37,6 +37,8 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 #include "base.h"
 #include "socketengine.h"
 #include "socket.h"
+#include "hash_map.h"
+#include "hashcomp.h"
 
 using namespace std;
 using irc::sockets::insp_aton;
@@ -50,13 +52,46 @@ class Module;
 /**
  * Result status, used internally
  */
-typedef std::pair<int,std::string> DNSResult;
+class DNSResult : public classbase
+{
+ public:
+       int id;
+       std::string result;
+       unsigned long ttl;
+       std::string original;
+
+       DNSResult(int i, const std::string &res, unsigned long timetolive, const std::string &orig) : id(i), result(res), ttl(timetolive), original(orig) { }
+};
 
 /**
  * Information on a completed lookup, used internally
  */
 typedef std::pair<unsigned char*, std::string> DNSInfo;
 
+/** Cached item
+ */
+class CachedQuery
+{
+ public:
+       std::string data;
+       time_t expires;
+
+       CachedQuery(const std::string &res, unsigned int ttl) : data(res)
+       {
+               expires = time(NULL) + ttl;
+       }
+
+       int CalcTTLRemaining()
+       {
+               int n = expires - time(NULL);
+               return (n < 0 ? 0 : n);
+       }
+};
+
+/** DNS cache information
+ */
+typedef nspace::hash_map<irc::string, CachedQuery, nspace::hash<irc::string> > dnscache;
+
 /**
  * Error types that class Resolver can emit to its error method.
  */
@@ -159,6 +194,16 @@ class Resolver : public Extensible
         * The core uses this to route results to the correct objects.
         */
        int myid;
+
+       /**
+        * Cached result, if there is one
+        */
+       CachedQuery *CQ;
+
+       /**
+        * Time left before cache expiry
+        */
+       int time_left;
  public:
        /**
         * Initiate DNS lookup. Your class should not attempt to delete or free these
@@ -183,6 +228,14 @@ class Resolver : public Extensible
         * To get around this automatic behaviour, you must use one of the values
         * DNS_QUERY_PTR4 or DNS_QUERY_PTR6 to force ipv4 or ipv6 behaviour on the lookup,
         * irrespective of what protocol InspIRCd has been built for.
+        * @param cached The constructor will set this boolean to true or false depending
+        * on whether the DNS lookup you are attempting is cached (and not expired) or not.
+        * If the value is cached, upon return this will be set to true, otherwise it will
+        * be set to false. You should pass this value to InspIRCd::AddResolver(), which
+        * will then influence the behaviour of the method and determine whether a cached
+        * or non-cached result is obtained. The value in this variable is always correct
+        * for the given request when the constructor exits.
+        * @param creator See the note below.
         * @throw ModuleException This class may throw an instance of ModuleException, in the
         * event a lookup could not be allocated, or a similar hard error occurs such as
         * the network being down. This will also be thrown if an invalid IP address is
@@ -193,7 +246,7 @@ class Resolver : public Extensible
         * whilst lookups are in progress, they can be safely removed and your module will not
         * crash the server.
         */
-       Resolver(InspIRCd* Instance, const std::string &source, QueryType qt, Module* creator = NULL);
+       Resolver(InspIRCd* Instance, const std::string &source, QueryType qt, bool &cached, Module* creator = NULL);
 
        /**
         * The default destructor does nothing.
@@ -202,8 +255,12 @@ class Resolver : public Extensible
        /**
         * When your lookup completes, this method will be called.
         * @param result The resulting DNS lookup, either an IP address or a hostname.
+        * @param ttl The time-to-live value of the result, in the instance of a cached
+        * result, this is the number of seconds remaining before refresh/expiry.
+        * @param cached True if the result is a cached result, false if it was requested
+        * from the DNS server.
         */
-       virtual void OnLookupComplete(const std::string &result) = 0;
+       virtual void OnLookupComplete(const std::string &result, unsigned int ttl, bool cached) = 0;
        /**
         * If an error occurs (such as NXDOMAIN, no domain name found) then this method
         * will be called.
@@ -225,6 +282,8 @@ class Resolver : public Extensible
         * Returns the creator module, or NULL
         */
        Module* GetCreator();
+
+       void TriggerCachedResult();
 };
 
 /** DNS is a singleton class used by the core to dispatch dns
@@ -262,6 +321,13 @@ class DNS : public EventHandler
         */
        bool ip6munge;
 
+       /**
+        * Currently cached items
+        */
+       dnscache* cache;
+
+       class CacheTimer* PruneTimer;
+
        /**
         * Build a dns packet payload
         */
@@ -344,7 +410,7 @@ class DNS : public EventHandler
        /**
         * Add a query to the list to be sent
         */
-       DNSRequest* AddQuery(DNSHeader *header, int &id);
+       DNSRequest* AddQuery(DNSHeader *header, int &id, const char* original);
 
        /**
         * The constructor initialises the dns socket,
@@ -380,6 +446,13 @@ class DNS : public EventHandler
         * are dns requests currently in progress.
         */
        void CleanResolvers(Module* module);
+
+       CachedQuery* GetCache(const std::string &source);
+
+       void DelCache(const std::string &source);
+
+       int ClearCache();
+       int PruneCache();
 };
 
 #endif