X-Git-Url: https://git.netwichtig.de/gitweb/?a=blobdiff_plain;f=include%2Fdns.h;h=05df6f69cb3baeb1efb5ac747b120126bbc580dc;hb=09c716ce117e3c89b4da7ab88f4caaefb43511b5;hp=c7283f6b864dcfb4581f6f7edb366d800f3c65eb;hpb=fe46f3c228ae993b59fbf5eca423c3171d90e1b3;p=user%2Fhenk%2Fcode%2Finspircd.git diff --git a/include/dns.h b/include/dns.h index c7283f6b8..05df6f69c 100644 --- a/include/dns.h +++ b/include/dns.h @@ -1,16 +1,24 @@ -/* +------------------------------------+ - * | Inspire Internet Relay Chat Daemon | - * +------------------------------------+ +/* + * InspIRCd -- Internet Relay Chat Daemon + * + * Copyright (C) 2009 Daniel De Graaf + * Copyright (C) 2005-2008 Craig Edwards + * Copyright (C) 2007 Dennis Friis * - * InspIRCd: (C) 2002-2007 InspIRCd Development Team - * See: http://www.inspircd.org/wiki/index.php/Credits + * This file is part of InspIRCd. InspIRCd is free software: you can + * redistribute it and/or modify it under the terms of the GNU General Public + * License as published by the Free Software Foundation, version 2. * - * This program is free but copyrighted software; see - * the file COPYING for details. + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS + * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more + * details. * - * --------------------------------------------------- + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . */ + /* dns.h - dns library very very loosely based on firedns, Copyright (C) 2002 Ian Gulliver @@ -29,38 +37,64 @@ along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ -#ifndef _DNS_H -#define _DNS_H +#ifndef DNS_H +#define DNS_H -#include -#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; +/** + * Query and resource record types + */ +enum QueryType +{ + /** 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 +}; /** * Result status, used internally */ -class DNSResult : public classbase +class CoreExport DNSResult { 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; + /** The type of the request + */ + QueryType type; - DNSResult(int i, const std::string &res, unsigned long timetolive, const std::string &orig) : id(i), result(res), ttl(timetolive), original(orig) { } + /** 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 + * @param qt The type of DNS query this result represents. + */ + DNSResult(int i, const std::string &res, unsigned long timetolive, const std::string &orig, QueryType qt = DNS_QUERY_NONE) : id(i), result(res), ttl(timetolive), original(orig), type(qt) { } }; /** @@ -68,29 +102,37 @@ class DNSResult : public classbase */ typedef std::pair DNSInfo; -/** Cached item +/** Cached item stored in the query cache. */ -class CachedQuery +class CoreExport CachedQuery { public: + /** The cached result data, an IP or hostname + */ std::string data; + /** The type of result this is + */ + QueryType type; + /** The time when the item is due to expire + */ time_t expires; - CachedQuery(const std::string &res, unsigned int ttl) : data(res) - { - expires = time(NULL) + ttl; - } + /** Build a cached query + * @param res The result data, an IP or hostname + * @param qt The type of DNS query this instance represents. + * @param ttl The time-to-live value of the query result + */ + CachedQuery(const std::string &res, QueryType qt, unsigned int ttl); - int CalcTTLRemaining() - { - int n = expires - time(NULL); - return (n < 0 ? 0 : n); - } + /** Returns the number of seconds remaining before this + * cache item has expired and should be removed. + */ + int CalcTTLRemaining(); }; -/** DNS cache information +/** DNS cache information. Holds IPs mapped to hostnames, and hostnames mapped to IPs. */ -typedef nspace::hash_map > dnscache; +typedef nspace::hash_map dnscache; /** * Error types that class Resolver can emit to its error method. @@ -100,58 +142,21 @@ enum ResolverError 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 request - */ -class DNSRequest; - -/** - * A DNS packet header - */ -class DNSHeader; - -/** - * A DNS Resource Record (rr) - */ -class 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 */ -}; - -#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 }; /** @@ -164,17 +169,13 @@ enum ForceProtocol * can occur by calling virtual methods, one is a success situation, and the other * an error situation. */ -class Resolver : public Extensible +class CoreExport Resolver { protected: - /** - * Pointer to creator - */ - InspIRCd* ServerInstance; /** * Pointer to creator module (if any, or NULL) */ - Module* Creator; + ModuleRef Creator; /** * The input data, either a host or an IP address */ @@ -204,6 +205,7 @@ class Resolver : public Extensible * Time left before cache expiry */ int time_left; + public: /** * Initiate DNS lookup. Your class should not attempt to delete or free these @@ -213,21 +215,12 @@ class Resolver : public Extensible * 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 @@ -246,12 +239,13 @@ 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, bool &cached, Module* creator = NULL); + Resolver(const std::string &source, QueryType qt, bool &cached, Module* creator); /** * 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. @@ -261,6 +255,7 @@ class Resolver : public Extensible * 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. @@ -268,6 +263,7 @@ class Resolver : public Extensible * @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 @@ -283,6 +279,11 @@ class Resolver : public Extensible */ 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(); }; @@ -291,55 +292,49 @@ class Resolver : public Extensible * 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: - InspIRCd* ServerInstance; - /** * The maximum value of a dns request id, * 16 bits wide, 0xFFFF. */ static const int MAX_REQUEST_ID = 0xFFFF; - /** - * Server address being used currently + /** Maximum number of entries in cache */ - insp_inaddr myserver; - - /** - * A counter used to form part of the pseudo-random id - */ - int currid; - - /** - * We have to turn off a few checks on received packets - * when people are using 4in6 (e.g. ::ffff:xxxx). This is - * a temporary kludge, Please let me know if you know how - * to fix it. - */ - bool ip6munge; + static const unsigned int MAX_CACHE_SIZE = 1000; /** * Currently cached items */ dnscache* cache; + /** A timer which ticks every hour to remove expired + * items from the DNS cache. + */ + class CacheTimer* PruneTimer; + /** * Build a dns packet payload */ int MakePayload(const char* name, const QueryType rr, const unsigned short rr_class, unsigned char* payload); public: + + irc::sockets::sockaddrs myserver; + /** * 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. @@ -350,27 +345,22 @@ 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 */ 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 @@ -414,7 +404,7 @@ class DNS : public EventHandler * The constructor initialises the dns socket, * and clears the request lists. */ - DNS(InspIRCd* Instance); + DNS(); /** * Re-initialize the DNS subsystem. @@ -426,13 +416,6 @@ class DNS : public EventHandler */ ~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(); - /** * Turn an in6_addr into a .ip6.arpa domain */ @@ -445,9 +428,27 @@ 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(); }; #endif