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
|
# Copyright, 2009, 2012, by Samuel G. D. Williams. <http://www.codeotaku.com>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
begin
require 'win32/resolv'
rescue LoadError
# Ignore this - we aren't running on windows.
end
module RubyDNS
# This module encapsulates system dependent name lookup functionality.
module System
RESOLV_CONF = "/etc/resolv.conf"
HOSTS = "/etc/hosts"
def self.hosts_path
if RUBY_PLATFORM =~ /mswin32|mingw|bccwin/
Win32::Resolv.get_hosts_path
else
HOSTS
end
end
# This code is very experimental
class Hosts
def initialize
@addresses = {}
@names = {}
end
attr :addresses
attr :names
# This is used to match names against the list of known hosts:
def call(name)
@names.include?(name)
end
def lookup(name)
addresses = @names[name]
if addresses
addresses.last
else
nil
end
end
alias [] lookup
def add(address, names)
@addresses[address] ||= []
@addresses[address] += names
names.each do |name|
@names[name] ||= []
@names[name] << address
end
end
def parse_hosts(io)
io.each do |line|
line.sub!(/#.*/, '')
address, hostname, *aliases = line.split(/\s+/)
add(address, [hostname] + aliases)
end
end
def self.local
hosts = self.new
path = System::hosts_path
if path and File.exist?(path)
File.open(path) do |file|
hosts.parse_hosts(file)
end
end
return hosts
end
end
def self.parse_resolv_configuration(path)
nameservers = []
File.open(path) do |file|
file.each do |line|
# Remove any comments:
line.sub!(/[#;].*/, '')
# Extract resolv.conf command:
keyword, *args = line.split(/\s+/)
case keyword
when 'nameserver'
nameservers += args
end
end
end
return nameservers
end
def self.standard_connections(nameservers)
connections = []
nameservers.each do |host|
connections << [:udp, host, 53]
connections << [:tcp, host, 53]
end
return connections
end
# Get a list of standard nameserver connections which can be used for querying any standard servers that the system has been configured with. There is no equivalent facility to use the `hosts` file at present.
def self.nameservers
nameservers = []
if File.exist? RESOLV_CONF
nameservers = parse_resolv_configuration(RESOLV_CONF)
elsif defined?(Win32::Resolv) and RUBY_PLATFORM =~ /mswin32|cygwin|mingw|bccwin/
search, nameservers = Win32::Resolv.get_resolv_info
end
return standard_connections(nameservers)
end
end
end
|
