1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
|
/*
dns.h - dns library declarations 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 <string>
#include "inspircd_config.h"
#include "socket.h"
#include "base.h"
typedef std::pair<int,std::string> DNSResult;
typedef std::pair<unsigned char*, std::string> DNSInfo;
/**
* Error types that class Resolver can emit to its error method.
*/
enum ResolverError
{
RESOLVER_NOERROR = 0,
RESOLVER_NSDOWN = 1,
RESOLVER_NXDOMAIN = 2,
RESOLVER_NOTREADY = 3,
RESOLVER_BADIP = 4
};
/** 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 DNS : public Extensible
{
public:
int dns_getip(const char* name);
int dns_getname(const insp_inaddr* ip);
DNSResult dns_getresult();
DNS();
~DNS();
};
/**
* 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 Resolver : public Extensible
{
protected:
/**
* The input data, either a host or an IP address
*/
std::string input;
/**
* True if a forward lookup is being performed, false if otherwise
*/
bool fwd;
/**
* 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 pseud-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;
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 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.
* @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.
*/
Resolver(const std::string &source, bool forward);
/**
* 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.
*/
virtual void OnLookupComplete(const std::string &result) = 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();
};
/**
* Clear the pointer table used for Resolver classes,
* translate ServerConfig::DNSServer into an insp_inaddr,
* establish binding on UDP socket for DNS requests.
*/
void init_dns();
/**
* Deal with a Resolver class which has become readable
*/
void dns_deal_with_classes(int fd);
/**
* Add a resolver class to our active table
*/
bool dns_add_class(Resolver* r);
#endif
|
