Improve PRNG

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

diff --git a/include/dns.h b/include/dns.h
index f0ad8dd7ad79e345c284b9369af3cb53d6afafed..41f42f46aa0019ac586e77769f81b2d2c4bd06ed 100644 (file)
--- a/include/dns.h
+++ b/include/dns.h
@@ -40,7 +40,14 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 #include "socket.h"
 #include "base.h"
 
+/**
+ * Result status, used internally
+ */
 typedef std::pair<int,std::string> DNSResult;
+
+/**
+ * Information on a completed lookup, used internally
+ */
 typedef std::pair<unsigned char*, std::string> DNSInfo;
 
 /**
@@ -55,14 +62,29 @@ enum ResolverError
        RESOLVER_BADIP          =       4
 };
 
+/**
+ * A DNS request
+ */
 class DNSRequest;
+
+/**
+ * A DNS packet header
+ */
 class DNSHeader;
+
+/**
+ * A DNS Resource Record (rr)
+ */
 class ResourceRecord;
 
-/* A set of requests keyed by request id */
+/**
+ * A set of requests keyed by request id
+ */
 typedef std::map<int,DNSRequest*> requestlist;
 
-/* An iterator into a set of requests */
+/**
+ * An iterator into a set of requests
+ */
 typedef requestlist::iterator requestlist_iter;
 
 /**
@@ -92,7 +114,7 @@ class Resolver : public Extensible
         */
        std::string server;
        /**
-        * The ID allocated to your lookup. This is a pseud-random number
+        * The ID allocated to your lookup. This is a pseudo-random number
         * between 0 and 65535, a value of -1 indicating a failure.
         * The core uses this to route results to the correct objects.
         */
@@ -143,7 +165,9 @@ class Resolver : public Extensible
        int GetId();
 };
 
-/* Query and resource record types */
+/**
+ * Query and resource record types
+ */
 enum QueryType
 {
        DNS_QUERY_A     = 1,    /* 'A' record: an IP address */
@@ -159,27 +183,109 @@ class DNS : public Extensible
 {
  private:
 
+       /**
+        * The maximum value of a dns request id,
+        * 16 bits wide, 0xFFFF.
+        */
+       static const int MAX_REQUEST_ID = 0xFFFF;
+
+       /**
+        * Requests that are currently 'in flight
+        */
        requestlist requests;
+
+       /**
+        * Server address being used currently
+        */
        insp_inaddr myserver;
+
+       /**
+        * File descriptor being used to perform queries
+        */
        static int MasterSocket;
-       Resolver* Classes[65536];
+
+       /**
+        * A counter used to form part of the pseudo-random id
+        */
+       int currid;
+
+       /**
+        * Currently active Resolver classes
+        */
+       Resolver* Classes[MAX_REQUEST_ID];
+
+       /**
+        * Build a dns packet payload
+        */
        int MakePayload(const char* name, const QueryType rr, const unsigned short rr_class, unsigned char* payload);
 
  public:
 
+       /**
+        * Fill an rr (resource record) with data from input
+        */
        static void FillResourceRecord(ResourceRecord* rr, const unsigned char* input);
+       /**
+        * Fill a header with data from input limited by a length
+        */
        static void FillHeader(DNSHeader *header, const unsigned char *input, const int length);
+       /**
+        * Empty out a header into a data stream ready for transmission "on the wire"
+        */
        static void EmptyHeader(unsigned char *output, const DNSHeader *header, const int length);
+       /**
+        * Get the master socket fd, used internally
+        */
        static int GetMasterSocket();
 
+       /**
+        * Start the lookup of an ip from a hostname
+        */
        int GetIP(const char* name);
+
+       /**
+        * Start the lookup of a hostname from an ip
+        */
        int GetName(const insp_inaddr* ip);
+
+       /**
+        * Fetch the result string (an ip or host)
+        * and/or an error message to go with it.
+        */
        DNSResult GetResult();
+
+       /**
+        * Handle a SocketEngine read event
+        */
        void MarshallReads(int fd);
+
+       /**
+        * Add a Resolver* to the list of active classes
+        */
        bool AddResolverClass(Resolver* r);
+
+       /**
+        * Add a query to the list to be sent
+        */
        DNSRequest* AddQuery(DNSHeader *header, int &id);
+
+       /**
+        * The constructor initialises the dns socket,
+        * and clears the request lists.
+        */
        DNS();
+
+       /**
+        * Destructor
+        */
        ~DNS();
+
+       /** Portable random number generator, generates
+        * its random number from the ircd stats counters,
+        * effective user id, time of day and the rollover
+        * counter (currid)
+        */
+       unsigned long PRNG();
 };
 
 #endif