X-Git-Url: https://git.netwichtig.de/gitweb/?a=blobdiff_plain;f=include%2Fdns.h;h=4087e2476eef2bef4f176b1d583683bfa1236df5;hb=696ee9ff66bb94be2229bfa9c3dc288affc38a72;hp=41f42f46aa0019ac586e77769f81b2d2c4bd06ed;hpb=30911b2ae8c8d8bdf741fc642f49956b8c9b98c0;p=user%2Fhenk%2Fcode%2Finspircd.git diff --git a/include/dns.h b/include/dns.h index 41f42f46a..4087e2476 100644 --- a/include/dns.h +++ b/include/dns.h @@ -2,14 +2,11 @@ * | Inspire Internet Relay Chat Daemon | * +------------------------------------+ * - * InspIRCd is copyright (C) 2002-2006 ChatSpike-Dev. - * E-mail: - * - * + * InspIRCd: (C) 2002-2007 InspIRCd Development Team + * See: http://www.inspircd.org/wiki/index.php/Credits * - * Written by Craig Edwards, Craig McLure, and others. * This program is free but copyrighted software; see - * the file COPYING for details. + * the file COPYING for details. * * --------------------------------------------------- */ @@ -37,8 +34,18 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA #include #include "inspircd_config.h" -#include "socket.h" #include "base.h" +#include "socketengine.h" +#include "socket.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 @@ -59,7 +66,9 @@ enum ResolverError RESOLVER_NSDOWN = 1, RESOLVER_NXDOMAIN = 2, RESOLVER_NOTREADY = 3, - RESOLVER_BADIP = 4 + RESOLVER_BADIP = 4, + RESOLVER_TIMEOUT = 5, + RESLOVER_FORCEUNLOAD = 6 }; /** @@ -87,6 +96,39 @@ typedef std::map requestlist; */ typedef requestlist::iterator requestlist_iter; +/** + * 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 */ +}; + /** * 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 @@ -100,6 +142,14 @@ typedef requestlist::iterator requestlist_iter; class Resolver : public Extensible { protected: + /** + * Pointer to creator + */ + InspIRCd* ServerInstance; + /** + * Pointer to creator module (if any, or NULL) + */ + Module* Creator; /** * The input data, either a host or an IP address */ @@ -107,7 +157,7 @@ class Resolver : public Extensible /** * True if a forward lookup is being performed, false if otherwise */ - bool fwd; + QueryType querytype; /** * The DNS erver being used for lookups. If this is an empty string, * the value of ServerConfig::DNSServer is used instead. @@ -128,16 +178,33 @@ 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 forward Set to true to perform a forward lookup (hostname to ip) or false - * to perform a reverse lookup (ip to hostname). Lookups on A records and PTR - * records are supported. CNAME and MX are not supported by this resolver. - * If InspIRCd is compiled with ipv6 support, lookups on AAAA records are preferred - * and supported over A records. + * @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 + * 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. * @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. + * 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, bool forward); + Resolver(InspIRCd* Instance, const std::string &source, QueryType qt, Module* creator = NULL); + /** * The default destructor does nothing. */ @@ -163,15 +230,11 @@ class Resolver : public Extensible * this method will return -1. */ int GetId(); -}; -/** - * Query and resource record types - */ -enum QueryType -{ - DNS_QUERY_A = 1, /* 'A' record: an IP address */ - DNS_QUERY_PTR = 12 /* 'PTR' record: a hostname */ + /** + * Returns the creator module, or NULL + */ + Module* GetCreator(); }; /** DNS is a singleton class used by the core to dispatch dns @@ -179,10 +242,12 @@ enum QueryType * back to Resolver objects, based upon the request ID. You * should never use this class yourself. */ -class DNS : public Extensible +class DNS : public EventHandler { private: + InspIRCd* ServerInstance; + /** * The maximum value of a dns request id, * 16 bits wide, 0xFFFF. @@ -190,7 +255,7 @@ class DNS : public Extensible static const int MAX_REQUEST_ID = 0xFFFF; /** - * Requests that are currently 'in flight + * Requests that are currently 'in flight' */ requestlist requests; @@ -199,20 +264,18 @@ class DNS : public Extensible */ insp_inaddr myserver; - /** - * File descriptor being used to perform queries - */ - static int MasterSocket; - /** * A counter used to form part of the pseudo-random id */ int currid; /** - * Currently active Resolver classes + * 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. */ - Resolver* Classes[MAX_REQUEST_ID]; + bool ip6munge; /** * Build a dns packet payload @@ -220,6 +283,15 @@ class DNS : public Extensible 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]; + /** + * 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 @@ -234,19 +306,34 @@ class DNS : public Extensible */ static void EmptyHeader(unsigned char *output, const DNSHeader *header, const int length); /** - * Get the master socket fd, used internally + * Start the lookup of an ipv4 from a hostname */ - static int GetMasterSocket(); + int GetIP(const char* name); /** - * Start the lookup of an ip from a hostname + * 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 GetIP(const char* name); + int GetName(const insp_inaddr* ip); /** - * Start the lookup of a hostname from an ip + * 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 GetName(const insp_inaddr* ip); + 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) @@ -256,8 +343,9 @@ class DNS : public Extensible /** * Handle a SocketEngine read event + * Inherited from EventHandler */ - void MarshallReads(int fd); + void HandleEvent(EventType et, int errornum = 0); /** * Add a Resolver* to the list of active classes @@ -273,7 +361,7 @@ class DNS : public Extensible * The constructor initialises the dns socket, * and clears the request lists. */ - DNS(); + DNS(InspIRCd* Instance); /** * Destructor @@ -286,6 +374,18 @@ class DNS : public Extensible * counter (currid) */ unsigned long PRNG(); + + /** + * 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); }; #endif