summaryrefslogtreecommitdiff
path: root/include/dns.h
diff options
context:
space:
mode:
authorbrain <brain@e03df62e-2008-0410-955e-edbf42e46eb7>2007-01-09 22:31:19 +0000
committerbrain <brain@e03df62e-2008-0410-955e-edbf42e46eb7>2007-01-09 22:31:19 +0000
commit49e34a508d9070097fa6aae5bf611bdd5c2b0f2d (patch)
treec7b9ff06ae48b628a51515fe33e76daf362109c9 /include/dns.h
parentd569a50e74b431008d00740723e7189004d01fca (diff)
Comment on a lot of recently added stuff that wasnt properly documented (until now)
git-svn-id: http://svn.inspircd.org/repository/trunk/inspircd@6284 e03df62e-2008-0410-955e-edbf42e46eb7
Diffstat (limited to 'include/dns.h')
-rw-r--r--include/dns.h63
1 files changed, 59 insertions, 4 deletions
diff --git a/include/dns.h b/include/dns.h
index 562a49322..6913527ae 100644
--- a/include/dns.h
+++ b/include/dns.h
@@ -55,11 +55,25 @@ class Module;
class DNSResult : public classbase
{
public:
+ /** Result ID
+ */
int id;
+ /** Result body, a hostname or IP address
+ */
std::string result;
+ /** Time-to-live value of the result
+ */
unsigned long ttl;
+ /** The original request, a hostname or IP address
+ */
std::string original;
+ /** Build a DNS result.
+ * @param i The request ID
+ * @param res The request result, a hostname or IP
+ * @param timetolive The request time-to-live
+ * @param orig The original request, a hostname or IP
+ */
DNSResult(int i, const std::string &res, unsigned long timetolive, const std::string &orig) : id(i), result(res), ttl(timetolive), original(orig) { }
};
@@ -68,19 +82,30 @@ class DNSResult : public classbase
*/
typedef std::pair<unsigned char*, std::string> DNSInfo;
-/** Cached item
+/** Cached item stored in the query cache.
*/
class CachedQuery
{
public:
+ /** The cached result data, an IP or hostname
+ */
std::string data;
+ /** The time when the item is due to expire
+ */
time_t expires;
+ /** Build a cached query
+ * @param res The result data, an IP or hostname
+ * @param ttl The time-to-live value of the query result
+ */
CachedQuery(const std::string &res, unsigned int ttl) : data(res)
{
expires = time(NULL) + ttl;
}
+ /** Returns the number of seconds remaining before this
+ * cache item has expired and should be removed.
+ */
int CalcTTLRemaining()
{
int n = expires - time(NULL);
@@ -88,7 +113,7 @@ class CachedQuery
}
};
-/** DNS cache information
+/** DNS cache information. Holds IPs mapped to hostnames, and hostnames mapped to IPs.
*/
typedef nspace::hash_map<irc::string, CachedQuery, nspace::hash<irc::string> > dnscache;
@@ -277,12 +302,15 @@ class Resolver : public Extensible
* this method will return -1.
*/
int GetId();
-
/**
* Returns the creator module, or NULL
*/
Module* GetCreator();
-
+ /**
+ * If the result is a cached result, this triggers the objects
+ * OnLookupComplete. This is done because it is not safe to call
+ * the abstract virtual method from the constructor.
+ */
void TriggerCachedResult();
};
@@ -295,6 +323,9 @@ class DNS : public EventHandler
{
private:
+ /**
+ * Creator/Owner object
+ */
InspIRCd* ServerInstance;
/**
@@ -326,6 +357,9 @@ class DNS : public EventHandler
*/
dnscache* cache;
+ /** A timer which ticks every hour to remove expired
+ * items from the DNS cache.
+ */
class CacheTimer* PruneTimer;
/**
@@ -334,14 +368,17 @@ class DNS : public EventHandler
int MakePayload(const char* name, const QueryType rr, const unsigned short rr_class, unsigned char* payload);
public:
+
/**
* 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.
@@ -352,14 +389,17 @@ class DNS : public EventHandler
* 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);
+
/**
* Start the lookup of an ipv4 from a hostname
*/
@@ -447,11 +487,26 @@ class DNS : public EventHandler
*/
void CleanResolvers(Module* module);
+ /** Return the cached value of an IP or hostname
+ * @param source An IP or hostname to find in the cache.
+ * @return A pointer to a CachedQuery if the item exists,
+ * otherwise NULL.
+ */
CachedQuery* GetCache(const std::string &source);
+ /** Delete a cached item from the DNS cache.
+ * @param source An IP or hostname to remove
+ */
void DelCache(const std::string &source);
+ /** Clear all items from the DNS cache immediately.
+ */
int ClearCache();
+
+ /** Prune the DNS cache, e.g. remove all expired
+ * items and rehash the cache buckets, but leave
+ * items in the hash which are still valid.
+ */
int PruneCache();
};