#include "base.h"
#include "socketengine.h"
#include "socket.h"
+#include "hash_map.h"
+#include "hashcomp.h"
using namespace std;
using irc::sockets::insp_aton;
/**
* 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.
*/
*/
class ResourceRecord;
-/**
- * A set of requests keyed by request id
- */
-typedef std::map<int,DNSRequest*> requestlist;
-
-/**
- * An iterator into a set of requests
- */
-typedef requestlist::iterator requestlist_iter;
-
/**
* Query and resource record types
*/
* 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
* 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
* 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.
/**
* 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.
* Returns the creator module, or NULL
*/
Module* GetCreator();
+
+ void TriggerCachedResult();
};
/** DNS is a singleton class used by the core to dispatch dns
*/
static const int MAX_REQUEST_ID = 0xFFFF;
- /**
- * Requests that are currently 'in flight'
- */
- requestlist requests;
-
/**
* Server address being used currently
*/
*/
bool ip6munge;
+ /**
+ * Currently cached items
+ */
+ dnscache* cache;
+
+ class CacheTimer* PruneTimer;
+
/**
* Build a dns packet payload
*/
* Currently active Resolver classes
*/
Resolver* Classes[MAX_REQUEST_ID];
+ /**
+ * Requests that are currently 'in flight'
+ */
+ DNSRequest* requests[MAX_REQUEST_ID];
/**
* The port number DNS requests are made on,
* and replies have as a source-port number.
/**
* 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,
*/
DNS(InspIRCd* Instance);
+ /**
+ * Re-initialize the DNS subsystem.
+ */
+ void Rehash();
+
/**
* Destructor
*/
* 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