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Diffstat (limited to 'include/modules/dns.h')
| -rw-r--r-- | include/modules/dns.h | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/include/modules/dns.h b/include/modules/dns.h new file mode 100644 index 000000000..c76c53805 --- /dev/null +++ b/include/modules/dns.h @@ -0,0 +1,193 @@ +/* + * InspIRCd -- Internet Relay Chat Daemon + * + * Copyright (C) 2013 Adam <Adam@anope.org> + * Copyright (C) 2003-2013 Anope Team <team@anope.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/>. + */ + +#pragma once + +namespace DNS +{ + /** Valid query types + */ + enum QueryType + { + /* Nothing */ + QUERY_NONE, + /* A simple A lookup */ + QUERY_A = 1, + /* A CNAME lookup */ + QUERY_CNAME = 5, + /* Reverse DNS lookup */ + QUERY_PTR = 12, + /* IPv6 AAAA lookup */ + QUERY_AAAA = 28 + }; + + /** Flags that can be AND'd into DNSPacket::flags to receive certain values + */ + enum + { + QUERYFLAGS_QR = 0x8000, + QUERYFLAGS_OPCODE = 0x7800, + QUERYFLAGS_AA = 0x400, + QUERYFLAGS_TC = 0x200, + QUERYFLAGS_RD = 0x100, + QUERYFLAGS_RA = 0x80, + QUERYFLAGS_Z = 0x70, + QUERYFLAGS_RCODE = 0xF + }; + + enum Error + { + ERROR_NONE, + ERROR_UNKNOWN, + ERROR_UNLOADED, + ERROR_TIMEDOUT, + ERROR_NOT_AN_ANSWER, + ERROR_NONSTANDARD_QUERY, + ERROR_FORMAT_ERROR, + ERROR_SERVER_FAILURE, + ERROR_DOMAIN_NOT_FOUND, + ERROR_NOT_IMPLEMENTED, + ERROR_REFUSED, + ERROR_NO_RECORDS, + ERROR_INVALIDTYPE + }; + + const int PORT = 53; + + /** + * The maximum value of a dns request id, + * 16 bits wide, 0xFFFF. + */ + const int MAX_REQUEST_ID = 0xFFFF; + + class Exception : public ModuleException + { + public: + Exception(const std::string& message) : ModuleException(message) { } + }; + + struct Question + { + std::string name; + QueryType type; + unsigned short qclass; + + Question() : type(QUERY_NONE), qclass(0) { } + Question(const std::string& n, QueryType t, unsigned short c = 1) : name(n), type(t), qclass(c) { } + inline bool operator==(const Question& other) const { return name == other.name && type == other.type && qclass == other.qclass; } + + struct hash + { + size_t operator()(const Question& question) const + { + return irc::insensitive()(question.name); + } + }; + }; + + struct ResourceRecord : Question + { + unsigned int ttl; + std::string rdata; + time_t created; + + ResourceRecord(const std::string& n, QueryType t, unsigned short c = 1) : Question(n, t, c), ttl(0), created(ServerInstance->Time()) { } + ResourceRecord(const Question& question) : Question(question), ttl(0), created(ServerInstance->Time()) { } + }; + + struct Query + { + std::vector<Question> questions; + std::vector<ResourceRecord> answers; + Error error; + bool cached; + + Query() : error(ERROR_NONE), cached(false) { } + Query(const Question& question) : error(ERROR_NONE), cached(false) { questions.push_back(question); } + }; + + class ReplySocket; + class Request; + + /** DNS manager + */ + class Manager : public DataProvider + { + public: + Manager(Module* mod) : DataProvider(mod, "DNS") { } + + virtual void Process(Request* req) = 0; + virtual void RemoveRequest(Request* req) = 0; + virtual std::string GetErrorStr(Error) = 0; + }; + + /** A DNS query. + */ + class Request : public Timer, public Question + { + protected: + Manager* const manager; + public: + /* Use result cache if available */ + bool use_cache; + /* Request id */ + unsigned short id; + /* Creator of this request */ + Module* const creator; + + Request(Manager* mgr, Module* mod, const std::string& addr, QueryType qt, bool usecache = true) + : Timer((ServerInstance->Config->dns_timeout ? ServerInstance->Config->dns_timeout : 5), ServerInstance->Time()) + , Question(addr, qt) + , manager(mgr) + , use_cache(usecache) + , id(0) + , creator(mod) + { + ServerInstance->Timers.AddTimer(this); + } + + virtual ~Request() + { + manager->RemoveRequest(this); + } + + /** Called when this request succeeds + * @param r The query sent back from the nameserver + */ + virtual void OnLookupComplete(const Query* req) = 0; + + /** Called when this request fails or times out. + * @param r The query sent back from the nameserver, check the error code. + */ + virtual void OnError(const Query* req) { } + + /** Used to time out the query, calls OnError and asks the TimerManager + * to delete this request + */ + bool Tick(time_t now) + { + Query rr(*this); + rr.error = ERROR_TIMEDOUT; + this->OnError(&rr); + delete this; + return false; + } + }; + +} // namespace DNS |