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
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
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
|
