X-Git-Url: https://git.netwichtig.de/gitweb/?a=blobdiff_plain;f=include%2Fdns.h;h=adb9fdab853d02ab2f5eb5b5f1e1a23d95b3e780;hb=84083a73e80734e39892f44411549d2381654c95;hp=bfced41846fef83949d9ec4bb0212708b232462d;hpb=f1ca6c6d71f3e31b333e0be45294bcb30fd89b4d;p=user%2Fhenk%2Fcode%2Finspircd.git diff --git a/include/dns.h b/include/dns.h index bfced4184..adb9fdab8 100644 --- a/include/dns.h +++ b/include/dns.h @@ -52,14 +52,28 @@ 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) { } }; @@ -68,29 +82,44 @@ 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 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. */ +#ifndef WIN32 typedef nspace::hash_map > dnscache; +#else +typedef nspace::hash_map > dnscache; +#endif /** * Error types that class Resolver can emit to its error method. @@ -119,31 +148,29 @@ class DNSHeader; /** * 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 */ + 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 - +const QueryType DNS_QUERY_REVERSE = DNS_QUERY_PTR; /** * 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. @@ -164,7 +191,7 @@ 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 : public Extensible { protected: /** @@ -228,6 +255,14 @@ class Resolver : public Extensible * 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. + * @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 @@ -247,8 +282,14 @@ class Resolver : public Extensible /** * 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. + * @param resultnum Result number, for records with multiple matching results. + * Normally, you will only want to act on this when the result is 0. */ - virtual void OnLookupComplete(const std::string &result, unsigned int ttl) = 0; + virtual void OnLookupComplete(const std::string &result, unsigned int ttl, bool cached, int resultnum = 0) = 0; /** * If an error occurs (such as NXDOMAIN, no domain name found) then this method * will be called. @@ -265,12 +306,15 @@ 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(); }; @@ -279,10 +323,13 @@ 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: + /** + * Creator/Owner object + */ InspIRCd* ServerInstance; /** @@ -291,11 +338,6 @@ class DNS : public EventHandler */ 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 */ @@ -314,20 +356,37 @@ class DNS : public EventHandler */ 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: + + /** + * Server address being used currently + */ + int socketfamily; +#ifdef IPV6 + in6_addr myserver6; +#endif + 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. @@ -338,14 +397,17 @@ 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 */ @@ -379,8 +441,9 @@ class DNS : public EventHandler /** * Fetch the result string (an ip or host) * and/or an error message to go with it. + * @param resultnum Result number to fetch */ - DNSResult GetResult(); + DNSResult GetResult(int resultnum); /** * Handle a SocketEngine read event @@ -433,9 +496,27 @@ 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