1 /* +------------------------------------+
2 * | Inspire Internet Relay Chat Daemon |
3 * +------------------------------------+
5 * InspIRCd is copyright (C) 2002-2006 ChatSpike-Dev.
7 * <brain@chatspike.net>
8 * <Craig@chatspike.net>
10 * Written by Craig Edwards, Craig McLure, and others.
11 * This program is free but copyrighted software; see
12 * the file COPYING for details.
14 * ---------------------------------------------------
18 dns.h - dns library very very loosely based on
19 firedns, Copyright (C) 2002 Ian Gulliver
21 This program is free software; you can redistribute it and/or modify
22 it under the terms of version 2 of the GNU General Public License as
23 published by the Free Software Foundation.
25 This program is distributed in the hope that it will be useful,
26 but WITHOUT ANY WARRANTY; without even the implied warranty of
27 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
28 GNU General Public License for more details.
30 You should have received a copy of the GNU General Public License
31 along with this program; if not, write to the Free Software
32 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
39 #include "inspircd_config.h"
43 typedef std::pair<int,std::string> DNSResult;
44 typedef std::pair<unsigned char*, std::string> DNSInfo;
47 * Error types that class Resolver can emit to its error method.
53 RESOLVER_NXDOMAIN = 2,
54 RESOLVER_NOTREADY = 3,
62 * The Resolver class is a high-level abstraction for resolving DNS entries.
63 * It can do forward and reverse IPv4 lookups, and where IPv6 is supported, will
64 * also be able to do those, transparent of protocols. Module developers must
65 * extend this class via inheritence, and then insert a pointer to their derived
66 * class into the core using Server::AddResolver(). Once you have done this,
67 * the class will be able to receive callbacks. There are two callbacks which
68 * can occur by calling virtual methods, one is a success situation, and the other
71 class Resolver : public Extensible
75 * The input data, either a host or an IP address
79 * True if a forward lookup is being performed, false if otherwise
83 * The DNS erver being used for lookups. If this is an empty string,
84 * the value of ServerConfig::DNSServer is used instead.
88 * The ID allocated to your lookup. This is a pseud-random number
89 * between 0 and 65535, a value of -1 indicating a failure.
90 * The core uses this to route results to the correct objects.
95 * Initiate DNS lookup. Your class should not attempt to delete or free these
96 * objects, as the core will do this for you. They must always be created upon
97 * the heap using new, as you cannot be sure at what time they will be deleted.
98 * Allocating them on the stack or attempting to delete them yourself could cause
99 * the object to go 'out of scope' and cause a segfault in the core if the result
100 * arrives at a later time.
101 * @param source The IP or hostname to resolve
102 * @param forward Set to true to perform a forward lookup (hostname to ip) or false
103 * to perform a reverse lookup (ip to hostname). Lookups on A records and PTR
104 * records are supported. CNAME and MX are not supported by this resolver.
105 * If InspIRCd is compiled with ipv6 support, lookups on AAAA records are preferred
106 * and supported over A records.
107 * @throw ModuleException This class may throw an instance of ModuleException, in the
108 * event a lookup could not be allocated, or a similar hard error occurs such as
109 * the network being down.
111 Resolver(const std::string &source, bool forward);
113 * The default destructor does nothing.
117 * When your lookup completes, this method will be called.
118 * @param result The resulting DNS lookup, either an IP address or a hostname.
120 virtual void OnLookupComplete(const std::string &result) = 0;
122 * If an error occurs (such as NXDOMAIN, no domain name found) then this method
124 * @param e A ResolverError enum containing the error type which has occured.
125 * @param errormessage The error text of the error that occured.
127 virtual void OnError(ResolverError e, const std::string &errormessage);
129 * Returns the id value of this class. This is primarily used by the core
130 * to determine where in various tables to place a pointer to your class, but it
131 * is safe to call and use this method.
132 * As specified in RFC1035, each dns request has a 16 bit ID value, ranging
133 * from 0 to 65535. If there is an issue and the core cannot send your request,
134 * this method will return -1.
139 /** DNS is a singleton class used by the core to dispatch dns
140 * requests to the dns server, and route incoming dns replies
141 * back to Resolver objects, based upon the request ID. You
142 * should never use this class yourself.
144 class DNS : public Extensible
147 insp_inaddr myserver;
148 static int MasterSocket;
149 Resolver* Classes[65536];
151 static int GetMasterSocket();
152 int GetIP(const char* name);
153 int GetName(const insp_inaddr* ip);
154 DNSResult GetResult();
155 void MarshallReads(int fd);
156 bool AddResolverClass(Resolver* r);
157 DNSRequest* DNSAddQuery(DNSHeader *header, int &id);