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
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
|
module NetAddr
private
# IP MATH METHODS
#==============================================================================#
# binary_mirror()
#==============================================================================#
# given an integer and number of bits to consider, return its binary mirror
#
def binary_mirror(num, bit_count)
mirror = 0
bit_count.times do # make mirror image of num by capturning lsb and left-shifting it onto mirror
mirror = mirror << 1
lsb = num & 1
num = num >> 1
mirror = mirror | lsb
end
return(mirror)
end
module_function :binary_mirror
#==============================================================================#
# bits_to_mask()
#==============================================================================#
# convert a netmask (in bits) to an integer mask
#
def bits_to_mask(netmask,version)
return(0) if (netmask == 0)
all_f = 2**32-1
all_f = 2**128-1 if (version == 6)
return( all_f ^ (all_f >> netmask) )
end
module_function :bits_to_mask
#==============================================================================#
# detect_ip_version()
#==============================================================================#
# determine the ip version from ip address string.
#
# return 4, 6, or nil
#
def detect_ip_version(ip)
version = nil
if ( ip =~ /\./ && ip !~ /:/ )
version = 4
elsif (ip =~ /:/)
version = 6
else
raise ValidationError, "Could not auto-detect IP version for '#{ip}'."
end
return(version)
end
module_function :detect_ip_version
#==============================================================================#
# ip_count_to_size()
#==============================================================================#
# given an ip count, determine the most appropriate mask (in bits)
#
def ip_count_to_size(ipcount,version,extended=false)
address_len = 32
address_len = 128 if (version == 6 )
if (ipcount > 2**address_len)
raise BoundaryError, "Required IP count exceeds number of IP addresses available " +
"for IPv#{version}."
end
bits_needed = 0
until (2**bits_needed >= ipcount)
bits_needed += 1
end
subnet_bits = address_len - bits_needed
return( ip_int_to_str(bits_to_mask(subnet_bits, 4), 4) ) if (extended && version == 4)
return(subnet_bits)
end
module_function :ip_count_to_size
#==============================================================================#
# ip_int_to_str()
#==============================================================================#
# unpack an int into an ip address string
#
def ip_int_to_str(ip_int, version, ipv4_mapped=nil)
ip = nil
version = 4 if (!version && ip_int < 2**32)
if (version == 4)
octets = []
4.times do
octet = ip_int & 0xFF
octets.unshift(octet.to_s)
ip_int = ip_int >> 8
end
ip = octets.join('.')
else
fields = []
if (!ipv4_mapped)
loop_count = 8
else
loop_count = 6
ipv4_int = ip_int & 0xffffffff
ipv4_addr = ip_int_to_str(ipv4_int, 4)
fields.unshift(ipv4_addr)
ip_int = ip_int >> 32
end
loop_count.times do
octet = ip_int & 0xFFFF
octet = octet.to_s(16)
ip_int = ip_int >> 16
# if octet < 4 characters, then pad with 0's
(4 - octet.length).times do
octet = '0' << octet
end
fields.unshift(octet)
end
ip = fields.join(':')
end
return(ip)
end
module_function :ip_int_to_str
#==============================================================================#
# ip_str_to_int()
#==============================================================================#
# convert an ip string into an int
#
def ip_str_to_int(ip,version)
ip_int = 0
if ( version == 4)
octets = ip.split('.')
(0..3).each do |x|
octet = octets.pop.to_i
octet = octet << 8*x
ip_int = ip_int | octet
end
else
# if ipv4-mapped ipv6 addr
if (ip =~ /\./)
dotted_dec = true
end
# split up by ':'
fields = []
if (ip =~ /::/)
shrthnd = ip.split( /::/ )
if (shrthnd.length == 0)
return(0)
else
first_half = shrthnd[0].split( /:/ ) if (shrthnd[0])
sec_half = shrthnd[1].split( /:/ ) if (shrthnd[1])
first_half = [] if (!first_half)
sec_half = [] if (!sec_half)
end
missing_fields = 8 - first_half.length - sec_half.length
missing_fields -= 1 if dotted_dec
fields = fields.concat(first_half)
missing_fields.times {fields.push('0')}
fields = fields.concat(sec_half)
else
fields = ip.split(':')
end
if (dotted_dec)
ipv4_addr = fields.pop
ipv4_int = NetAddr.ip_to_i(ipv4_addr, :Version => 4)
octets = []
2.times do
octet = ipv4_int & 0xFFFF
octets.unshift(octet.to_s(16))
ipv4_int = ipv4_int >> 16
end
fields.concat(octets)
end
# pack
(0..7).each do |x|
field = fields.pop.to_i(16)
field = field << 16*x
ip_int = ip_int | field
end
end
return(ip_int)
end
module_function :ip_str_to_int
#==============================================================================#
# mask_to_bits()
#==============================================================================#
# convert integer into a cidr formatted netmask (bits)
#
def mask_to_bits(netmask_int)
return(netmask_int) if (netmask_int == 0)
mask = nil
if (netmask_int < 2**32)
mask = 32
validate_netmask_int(netmask_int, 4, true)
else
mask = 128
validate_netmask_int(netmask_int, 6, true)
end
mask.times do
if ( (netmask_int & 1) == 1)
break
end
netmask_int = netmask_int >> 1
mask = mask - 1
end
return(mask)
end
module_function :mask_to_bits
#==============================================================================#
# netmask_str_to_int()
#==============================================================================#
# convert string into integer mask
#
def netmask_str_to_int(netmask,version)
netmask_int = nil
all_f = 2**32-1
all_f = 2**128-1 if (version == 6)
if(netmask =~ /\./)
netmask_int = NetAddr.ip_to_i(netmask)
else
# remove '/' if present
if (netmask =~ /^\// )
netmask[0] = " "
netmask.lstrip!
end
netmask = netmask.to_i
netmask_int = all_f ^ (all_f >> netmask)
end
return(netmask_int)
end
module_function :netmask_str_to_int
end # module NetAddr
__END__
|
