1 #!powershell
2
3 # Copyright: (c) 2018, Micah Hunsberger (@mhunsber)
4 # GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
5
6 #AnsibleRequires -CSharpUtil Ansible.Basic
7
8 Set-StrictMode -Version 2
9 $ErrorActionPreference = "Stop"
10
11 $spec = @{
12 options = @{
13 state = @{ type = "str"; choices = "absent", "present"; default = "present" }
14 aliases = @{ type = "list"; elements = "str" }
15 canonical_name = @{ type = "str" }
16 ip_address = @{ type = "str" }
17 action = @{ type = "str"; choices = "add", "remove", "set"; default = "set" }
18 }
19 required_if = @(,@( "state", "present", @("canonical_name", "ip_address")))
20 supports_check_mode = $true
21 }
22
23 $module = [Ansible.Basic.AnsibleModule]::Create($args, $spec)
24
25 $state = $module.Params.state
26 $aliases = $module.Params.aliases
27 $canonical_name = $module.Params.canonical_name
28 $ip_address = $module.Params.ip_address
29 $action = $module.Params.action
30
31 $tmp = [ipaddress]::None
32 if($ip_address -and -not [ipaddress]::TryParse($ip_address, [ref]$tmp)){
33 $module.FailJson("win_hosts: Argument ip_address needs to be a valid ip address, but was $ip_address")
34 }
35 $ip_address_type = $tmp.AddressFamily
36
37 $hosts_file = Get-Item -LiteralPath "$env:SystemRoot\System32\drivers\etc\hosts"
38
Get-CommentIndex($line)39 Function Get-CommentIndex($line) {
40 $c_index = $line.IndexOf('#')
41 if($c_index -lt 0) {
42 $c_index = $line.Length
43 }
44 return $c_index
45 }
46
Get-HostEntryParts($line)47 Function Get-HostEntryParts($line) {
48 $success = $true
49 $c_index = Get-CommentIndex -line $line
50 $pure_line = $line.Substring(0,$c_index).Trim()
51 $bits = $pure_line -split "\s+"
52 if($bits.Length -lt 2){
53 return @{
54 success = $false
55 ip_address = ""
56 ip_type = ""
57 canonical_name = ""
58 aliases = @()
59 }
60 }
61 $ip_obj = [ipaddress]::None
62 if(-not [ipaddress]::TryParse($bits[0], [ref]$ip_obj) ){
63 $success = $false
64 }
65 $cname = $bits[1]
66 $als = New-Object string[] ($bits.Length - 2)
67 [array]::Copy($bits, 2, $als, 0, $als.Length)
68 return @{
69 success = $success
70 ip_address = $ip_obj.IPAddressToString
71 ip_type = $ip_obj.AddressFamily
72 canonical_name = $cname
73 aliases = $als
74 }
75 }
76
Find-HostName($line, $name)77 Function Find-HostName($line, $name) {
78 $c_idx = Get-CommentIndex -line $line
79 $re = New-Object regex ("\s+$($name.Replace('.',"\."))(\s|$)", [System.Text.RegularExpressions.RegexOptions]::IgnoreCase)
80 $match = $re.Match($line, 0, $c_idx)
81 return $match
82 }
83
Remove-HostEntry($list, $idx)84 Function Remove-HostEntry($list, $idx) {
85 $module.Result.changed = $true
86 $list.RemoveAt($idx)
87 }
88
Add-HostEntry($list, $cname, $aliases, $ip)89 Function Add-HostEntry($list, $cname, $aliases, $ip) {
90 $module.Result.changed = $true
91 $line = "$ip $cname $($aliases -join ' ')"
92 $list.Add($line) | Out-Null
93 }
94
Remove-HostnamesFromEntry($list, $idx, $aliases)95 Function Remove-HostnamesFromEntry($list, $idx, $aliases) {
96 $line = $list[$idx]
97 $line_removed = $false
98
99 foreach($name in $aliases){
100 $match = Find-HostName -line $line -name $name
101 if($match.Success){
102 $line = $line.Remove($match.Index + 1, $match.Length -1)
103 # was this the last alias? (check for space characters after trimming)
104 if($line.Substring(0,(Get-CommentIndex -line $line)).Trim() -inotmatch "\s") {
105 $list.RemoveAt($idx)
106 $line_removed = $true
107 # we're done
108 return @{
109 line_removed = $line_removed
110 }
111 }
112 }
113 }
114 if($line -ne $list[$idx]){
115 $module.Result.changed = $true
116 $list[$idx] = $line
117 }
118 return @{
119 line_removed = $line_removed
120 }
121 }
122
Add-AliasesToEntry($list, $idx, $aliases)123 Function Add-AliasesToEntry($list, $idx, $aliases) {
124 $line = $list[$idx]
125 foreach($name in $aliases){
126 $match = Find-HostName -line $line -name $name
127 if(-not $match.Success) {
128 # just add the alias before the comment
129 $line = $line.Insert((Get-CommentIndex -line $line), " $name ")
130 }
131 }
132 if($line -ne $list[$idx]){
133 $module.Result.changed = $true
134 $list[$idx] = $line
135 }
136 }
137
138 $hosts_lines = New-Object System.Collections.ArrayList
139
140 Get-Content -LiteralPath $hosts_file.FullName | ForEach-Object { $hosts_lines.Add($_) } | Out-Null
141 $module.Diff.before = ($hosts_lines -join "`n") + "`n"
142
143 if ($state -eq 'absent') {
144 # go through and remove canonical_name and ip
145 for($idx = 0; $idx -lt $hosts_lines.Count; $idx++) {
146 $entry = $hosts_lines[$idx]
147 # skip comment lines
148 if(-not $entry.Trim().StartsWith('#')) {
149 $entry_parts = Get-HostEntryParts -line $entry
150 if($entry_parts.success) {
151 if(-not $ip_address -or $entry_parts.ip_address -eq $ip_address) {
152 if(-not $canonical_name -or $entry_parts.canonical_name -eq $canonical_name) {
153 if(Remove-HostEntry -list $hosts_lines -idx $idx){
154 # keep index correct if we removed the line
155 $idx = $idx - 1
156 }
157 }
158 }
159 }
160 }
161 }
162 }
163 if($state -eq 'present') {
164 $entry_idx = -1
165 $aliases_to_keep = @()
166 # go through lines, find the entry and determine what to remove based on action
167 for($idx = 0; $idx -lt $hosts_lines.Count; $idx++) {
168 $entry = $hosts_lines[$idx]
169 # skip comment lines
170 if(-not $entry.Trim().StartsWith('#')) {
171 $entry_parts = Get-HostEntryParts -line $entry
172 if($entry_parts.success) {
173 $aliases_to_remove = @()
174 if($entry_parts.ip_address -eq $ip_address) {
175 if($entry_parts.canonical_name -eq $canonical_name) {
176 $entry_idx = $idx
177
178 if($action -eq 'set') {
179 $aliases_to_remove = $entry_parts.aliases | Where-Object { $aliases -notcontains $_ }
180 } elseif($action -eq 'remove') {
181 $aliases_to_remove = $aliases
182 }
183 } else {
184 # this is the right ip_address, but not the cname we were looking for.
185 # we need to make sure none of aliases or canonical_name exist for this entry
186 # since the given canonical_name should be an A/AAAA record,
187 # and aliases should be cname records for the canonical_name.
188 $aliases_to_remove = $aliases + $canonical_name
189 }
190 } else {
191 # this is not the ip_address we are looking for
192 if ($ip_address_type -eq $entry_parts.ip_type) {
193 if ($entry_parts.canonical_name -eq $canonical_name) {
194 Remove-HostEntry -list $hosts_lines -idx $idx
195 $idx = $idx - 1
196 if ($action -ne "set") {
197 # keep old aliases intact
198 $aliases_to_keep += $entry_parts.aliases | Where-Object { ($aliases + $aliases_to_keep + $canonical_name) -notcontains $_ }
199 }
200 } elseif ($action -eq "remove") {
201 $aliases_to_remove = $canonical_name
202 } elseif ($aliases -contains $entry_parts.canonical_name) {
203 Remove-HostEntry -list $hosts_lines -idx $idx
204 $idx = $idx - 1
205 if ($action -eq "add") {
206 # keep old aliases intact
207 $aliases_to_keep += $entry_parts.aliases | Where-Object { ($aliases + $aliases_to_keep + $canonical_name) -notcontains $_ }
208 }
209 } else {
210 $aliases_to_remove = $aliases + $canonical_name
211 }
212 } else {
213 # TODO: Better ipv6 support. There is odd behavior for when an alias can be used for both ipv6 and ipv4
214 }
215 }
216
217 if($aliases_to_remove) {
218 if((Remove-HostnamesFromEntry -list $hosts_lines -idx $idx -aliases $aliases_to_remove).line_removed) {
219 $idx = $idx - 1
220 }
221 }
222 }
223 }
224 }
225
226 if($entry_idx -ge 0) {
227 $aliases_to_add = @()
228 $entry_parts = Get-HostEntryParts -line $hosts_lines[$entry_idx]
229 if($action -eq 'remove') {
230 $aliases_to_add = $aliases_to_keep | Where-Object { $entry_parts.aliases -notcontains $_ }
231 } else {
232 $aliases_to_add = ($aliases + $aliases_to_keep) | Where-Object { $entry_parts.aliases -notcontains $_ }
233 }
234
235 if($aliases_to_add) {
236 Add-AliasesToEntry -list $hosts_lines -idx $entry_idx -aliases $aliases_to_add
237 }
238 } else {
239 # add the entry at the end
240 if($action -eq 'remove') {
241 if($aliases_to_keep) {
242 Add-HostEntry -list $hosts_lines -ip $ip_address -cname $canonical_name -aliases $aliases_to_keep
243 } else {
244 Add-HostEntry -list $hosts_lines -ip $ip_address -cname $canonical_name
245 }
246 } else {
247 Add-HostEntry -list $hosts_lines -ip $ip_address -cname $canonical_name -aliases ($aliases + $aliases_to_keep)
248 }
249 }
250 }
251
252 $module.Diff.after = ($hosts_lines -join "`n") + "`n"
253 if( $module.Result.changed -and -not $module.CheckMode ) {
254 Set-Content -LiteralPath $hosts_file.FullName -Value $hosts_lines
255 }
256
257 $module.ExitJson()
258