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Diffstat (limited to 'include/dns.h')
| -rw-r--r-- | include/dns.h | 455 |
1 files changed, 0 insertions, 455 deletions
diff --git a/include/dns.h b/include/dns.h deleted file mode 100644 index 05df6f69c..000000000 --- a/include/dns.h +++ /dev/null @@ -1,455 +0,0 @@ -/* - * InspIRCd -- Internet Relay Chat Daemon - * - * Copyright (C) 2009 Daniel De Graaf <danieldg@inspircd.org> - * Copyright (C) 2005-2008 Craig Edwards <craigedwards@brainbox.cc> - * Copyright (C) 2007 Dennis Friis <peavey@inspircd.org> - * - * 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 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 <http://www.gnu.org/licenses/>. - */ - - -/* -dns.h - dns library very very loosely based on -firedns, Copyright (C) 2002 Ian Gulliver - -This program is free software; you can redistribute it and/or modify -it under the terms of version 2 of the GNU General Public License as -published by the Free Software Foundation. - -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, write to the Free Software -Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA -*/ - -#ifndef DNS_H -#define DNS_H - -#include "socket.h" -#include "hashcomp.h" - -/** - * 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 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; - - /** 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) { } -}; - -/** - * Information on a completed lookup, used internally - */ -typedef std::pair<unsigned char*, std::string> DNSInfo; - -/** Cached item stored in the query cache. - */ -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; - - /** 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); - - /** Returns the number of seconds remaining before this - * cache item has expired and should be removed. - */ - int CalcTTLRemaining(); -}; - -/** DNS cache information. Holds IPs mapped to hostnames, and hostnames mapped to IPs. - */ -typedef nspace::hash_map<irc::string, CachedQuery, irc::hash> dnscache; - -/** - * Error types that class Resolver can emit to its error method. - */ -enum ResolverError -{ - RESOLVER_NOERROR = 0, - RESOLVER_NSDOWN = 1, - RESOLVER_NXDOMAIN = 2, - RESOLVER_BADIP = 3, - RESOLVER_TIMEOUT = 4, - RESOLVER_FORCEUNLOAD = 5 -}; - -/** - * 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 -{ - /** Forced to use ipv4 */ - PROTOCOL_IPV4 = 0, - /** Forced to use ipv6 */ - PROTOCOL_IPV6 = 1 -}; - -/** - * The Resolver class is a high-level abstraction for resolving DNS entries. - * It can do forward and reverse IPv4 lookups, and where IPv6 is supported, will - * also be able to do those, transparent of protocols. Module developers must - * extend this class via inheritence, and then insert a pointer to their derived - * class into the core using Server::AddResolver(). Once you have done this, - * the class will be able to receive callbacks. There are two callbacks which - * can occur by calling virtual methods, one is a success situation, and the other - * an error situation. - */ -class CoreExport Resolver -{ - protected: - /** - * Pointer to creator module (if any, or NULL) - */ - ModuleRef Creator; - /** - * The input data, either a host or an IP address - */ - std::string input; - /** - * True if a forward lookup is being performed, false if otherwise - */ - QueryType querytype; - /** - * The DNS erver being used for lookups. If this is an empty string, - * the value of ServerConfig::DNSServer is used instead. - */ - std::string server; - /** - * 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. - */ - 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 - * objects, as the core will do this for you. They must always be created upon - * the heap using new, as you cannot be sure at what time they will be deleted. - * Allocating them on the stack or attempting to delete them yourself could cause - * 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. 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. - * 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 - * 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 - * passed when resolving a 'PTR' record. - * - * NOTE: If you are instantiating your DNS lookup from a module, you should set the - * value of creator to point at your Module class. This way if your module is unloaded - * whilst lookups are in progress, they can be safely removed and your module will not - * crash the server. - */ - 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. - * @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, unsigned int ttl, bool cached) = 0; - - /** - * If an error occurs (such as NXDOMAIN, no domain name found) then this method - * will be called. - * @param e A ResolverError enum containing the error type which has occured. - * @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 - * is safe to call and use this method. - * As specified in RFC1035, each dns request has a 16 bit ID value, ranging - * from 0 to 65535. If there is an issue and the core cannot send your request, - * 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(); -}; - -/** DNS is a singleton class used by the core to dispatch dns - * requests to the dns server, and route incoming dns replies - * back to Resolver objects, based upon the request ID. You - * should never use this class yourself. - */ -class CoreExport DNS : public EventHandler -{ - private: - - /** - * The maximum value of a dns request id, - * 16 bits wide, 0xFFFF. - */ - static const int MAX_REQUEST_ID = 0xFFFF; - - /** Maximum number of entries in cache - */ - 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. - */ - static const int QUERY_PORT = 53; - - /** - * 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 lookup of a hostname from an ip, but - * force a specific protocol to be used for the lookup - * for example to perform an ipv6 reverse lookup. - */ - int GetNameForce(const char *ip, ForceProtocol fp); - - /** - * Start lookup of an ipv6 from a hostname - */ - int GetIP6(const char *name); - - /** - * Start lookup of a CNAME from another hostname - */ - int GetCName(const char* alias); - - /** - * Fetch the result string (an ip or host) - * and/or an error message to go with it. - */ - DNSResult GetResult(); - - /** - * Handle a SocketEngine read event - * Inherited from EventHandler - */ - void HandleEvent(EventType et, int errornum = 0); - - /** - * 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, const char* original); - - /** - * The constructor initialises the dns socket, - * and clears the request lists. - */ - DNS(); - - /** - * Re-initialize the DNS subsystem. - */ - void Rehash(); - - /** - * Destructor - */ - ~DNS(); - - /** - * Turn an in6_addr into a .ip6.arpa domain - */ - static void MakeIP6Int(char* query, const in6_addr *ip); - - /** - * Clean out all dns resolvers owned by a particular - * module, to make unloading a module safe if there - * are dns requests currently in progress. - */ - 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 - |