* | Inspire Internet Relay Chat Daemon |
* +------------------------------------+
*
- * InspIRCd: (C) 2002-2007 InspIRCd Development Team
- * See: http://www.inspircd.org/wiki/index.php/Credits
+ * InspIRCd: (C) 2002-2009 InspIRCd Development Team
+ * See: http://wiki.inspircd.org/Credits
*
* This program is free but copyrighted software; see
* the file COPYING for details.
#ifndef _DNS_H
#define _DNS_H
-#include <string>
-#include "inspircd_config.h"
-#include "base.h"
-#include "socketengine.h"
#include "socket.h"
-#include "hash_map.h"
#include "hashcomp.h"
-using namespace std;
-using irc::sockets::insp_aton;
-using irc::sockets::insp_ntoa;
-using irc::sockets::insp_sockaddr;
-using irc::sockets::insp_inaddr;
-
-class InspIRCd;
class Module;
/**
* Result status, used internally
*/
-class DNSResult : public classbase
+class CoreExport 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) { }
};
*/
typedef std::pair<unsigned char*, std::string> DNSInfo;
-/** Cached item
+/** Cached item stored in the query cache.
*/
-class CachedQuery
+class CoreExport CachedQuery : public classbase
{
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);
+ int n = (int)expires - (int)time(NULL);
return (n < 0 ? 0 : n);
}
};
-/** DNS cache information
+/** DNS cache information. Holds IPs mapped to hostnames, and hostnames mapped to IPs.
*/
+#if defined(WINDOWS) && !defined(HASHMAP_DEPRECATED)
+typedef nspace::hash_map<irc::string, CachedQuery, nspace::hash_compare<irc::string> > dnscache;
+#else
typedef nspace::hash_map<irc::string, CachedQuery, nspace::hash<irc::string> > dnscache;
+#endif
/**
* Error types that class Resolver can emit to its error method.
RESOLVER_NOERROR = 0,
RESOLVER_NSDOWN = 1,
RESOLVER_NXDOMAIN = 2,
- RESOLVER_NOTREADY = 3,
- RESOLVER_BADIP = 4,
- RESOLVER_TIMEOUT = 5,
- RESLOVER_FORCEUNLOAD = 6
+ RESOLVER_BADIP = 3,
+ RESOLVER_TIMEOUT = 4,
+ RESOLVER_FORCEUNLOAD = 5
};
/**
/**
* A DNS Resource Record (rr)
*/
-class ResourceRecord;
+struct ResourceRecord;
/**
* Query and resource record types
*/
enum QueryType
{
- DNS_QUERY_NONE = 0, /* Uninitialized Query */
- DNS_QUERY_A = 1, /* 'A' record: an ipv4 address */
- DNS_QUERY_CNAME = 5, /* 'CNAME' record: An alias */
- DNS_QUERY_PTR = 12, /* 'PTR' record: a hostname */
- DNS_QUERY_AAAA = 28, /* 'AAAA' record: an ipv6 address */
-
- DNS_QUERY_PTR4 = 0xFFFD, /* Force 'PTR' to use IPV4 scemantics */
- DNS_QUERY_PTR6 = 0xFFFE, /* Force 'PTR' to use IPV6 scemantics */
+ /** Uninitialized Query */
+ DNS_QUERY_NONE = 0,
+ /** 'A' record: an ipv4 address */
+ DNS_QUERY_A = 1,
+ /** 'CNAME' record: An alias */
+ DNS_QUERY_CNAME = 5,
+ /** 'PTR' record: a hostname */
+ DNS_QUERY_PTR = 12,
+ /** 'AAAA' record: an ipv6 address */
+ DNS_QUERY_AAAA = 28,
+
+ /** Force 'PTR' to use IPV4 scemantics */
+ DNS_QUERY_PTR4 = 0xFFFD,
+ /** Force 'PTR' to use IPV6 scemantics */
+ DNS_QUERY_PTR6 = 0xFFFE
};
-#ifdef IPV6
-const QueryType DNS_QUERY_FORWARD = DNS_QUERY_AAAA;
-const QueryType DNS_QUERY_REVERSE = DNS_QUERY_PTR;
-#else
-const QueryType DNS_QUERY_FORWARD = DNS_QUERY_A;
-const QueryType DNS_QUERY_REVERSE = DNS_QUERY_PTR;
-#endif
-
/**
* Used internally to force PTR lookups to use a certain protocol scemantics,
* e.g. x.x.x.x.in-addr.arpa for v4, and *.ip6.arpa for v6.
*/
enum ForceProtocol
{
- PROTOCOL_IPV4 = 0, /* Forced to use ipv4 */
- PROTOCOL_IPV6 = 1 /* Forced to use ipv6 */
+ /** Forced to use ipv4 */
+ PROTOCOL_IPV4 = 0,
+ /** Forced to use ipv6 */
+ PROTOCOL_IPV6 = 1
};
/**
* can occur by calling virtual methods, one is a success situation, and the other
* an error situation.
*/
-class Resolver : public Extensible
+class CoreExport Resolver : public Extensible
{
protected:
/**
* Time left before cache expiry
*/
int time_left;
+
public:
/**
* Initiate DNS lookup. Your class should not attempt to delete or free these
* the object to go 'out of scope' and cause a segfault in the core if the result
* arrives at a later time.
* @param source The IP or hostname to resolve
- * @param qt The query type to perform. If you just want to perform a forward
- * or reverse lookup, and you don't care wether you get ipv4 or ipv6, then use
- * the constants DNS_QUERY_FORWARD and DNS_QUERY_REVERSE, which automatically
- * select from 'A' record or 'AAAA' record lookups. However, if you want to resolve
- * a specific record type, resolution of 'A', 'AAAA', 'PTR' and 'CNAME' records
+ * @param qt The query type to perform. Resolution of 'A', 'AAAA', 'PTR' and 'CNAME' records
* is supported. Use one of the QueryType enum values to initiate this type of
* lookup. Resolution of 'AAAA' ipv6 records is always supported, regardless of
* wether InspIRCd is built with ipv6 support.
- * If you attempt to resolve a 'PTR' record using DNS_QUERY_PTR, and InspIRCd is
- * built with ipv6 support, the 'PTR' record will be formatted to ipv6 specs,
- * e.g. x.x.x.x.x....ip6.arpa. otherwise it will be formatted to ipv4 specs,
- * e.g. x.x.x.x.in-addr.arpa. This translation is automatic.
- * 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.
+ * To look up reverse records, specify one of DNS_QUERY_PTR4 or DNS_QUERY_PTR6 depending
+ * on the type of address you are looking up.
* @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
* The default destructor does nothing.
*/
virtual ~Resolver();
+
/**
* When your lookup completes, this method will be called.
* @param result The resulting DNS lookup, either an IP address or a hostname.
* from the DNS server.
*/
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.
* @param errormessage The error text of the error that occured.
*/
virtual void OnError(ResolverError e, const std::string &errormessage);
+
/**
* Returns the id value of this class. This is primarily used by the core
* to determine where in various tables to place a pointer to your class, but it
*/
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();
};
* back to Resolver objects, based upon the request ID. You
* should never use this class yourself.
*/
-class DNS : public EventHandler
+class CoreExport DNS : public EventHandler
{
private:
+ /**
+ * Creator/Owner object
+ */
InspIRCd* ServerInstance;
/**
*/
static const int MAX_REQUEST_ID = 0xFFFF;
- /**
- * Server address being used currently
- */
- insp_inaddr myserver;
-
/**
* A counter used to form part of the pseudo-random id
*/
*/
dnscache* cache;
+ /** A timer which ticks every hour to remove expired
+ * items from the DNS cache.
+ */
class CacheTimer* PruneTimer;
/**
int MakePayload(const char* name, const QueryType rr, const unsigned short rr_class, unsigned char* payload);
public:
+
+ /**
+ * Server address being used currently
+ */
+ int socketfamily;
+
+ /**
+ * IPV6 server address
+ */
+ in6_addr myserver6;
+
+ /**
+ * IPV4 server address
+ */
+ in_addr myserver4;
+
/**
* 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.
* 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
*/
int GetIP(const char* name);
- /**
- * Start the lookup of a hostname from an ip,
- * always using the protocol inspircd is built for,
- * e.g. use ipv6 reverse lookup when built for ipv6,
- * or ipv4 lookup when built for ipv4.
- */
- int GetName(const insp_inaddr* ip);
-
/**
* Start lookup of a hostname from an ip, but
* force a specific protocol to be used for the lookup
*/
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();
};