summaryrefslogtreecommitdiff
path: root/scripts/system/vyatta_update_resolv.pl
blob: 224d002d219e99b0e6c5069ee877002970f3fc84 (plain)
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
#!/usr/bin/perl -w
#
# Module: vyatta_update_resolv.pl
#
# **** License ****
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 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.
#
# This code was originally developed by Vyatta, Inc.
# Portions created by Vyatta are Copyright (C) 2007 Vyatta, Inc.
# All Rights Reserved.
#
# Author: Marat Nepomnyashy
# Date: December 2007
# Description: Script to update '/etc/resolv.conf' on commit of 'system domain-search domain' config.
#
# **** End License ****
#

use strict;
use lib "/opt/vyatta/share/perl5/";


use Getopt::Long;
my $dhclient_script = 0;
GetOptions("dhclient-script=i" => \$dhclient_script);

use Vyatta::Config;
my $vc = new Vyatta::Config();

$vc->setLevel('system');
my @domains;
my $domain_name = undef;

if ($dhclient_script == 1) {
   @domains = $vc->returnOrigValues('domain-search domain');
   $domain_name = $vc->returnOrigValue('domain-name');
} else {
   @domains = $vc->returnValues('domain-search domain');
   $domain_name = $vc->returnValue('domain-name');
}

if ($dhclient_script == 0 && @domains > 0 && $domain_name && length($domain_name) > 0) {
        $vc->outputError(["system domain-name","system domain-search"],"System configuration error.  Both \'domain-name\' and \'domain-search\' are specified, but only one of these mutually exclusive parameters is allowed.");
	exit(1);
}

my $doms = '';
foreach my $domain (@domains) {
	if (length($doms) > 0) {
		$doms .= ' ';
	}
	$doms .= $domain;
}

# add domain names received from dhcp client to domain search in /etc/resolv.conf if domain-name not set in CLI
if (!defined($domain_name)) {
  my @dhcp_interfaces_resolv_files = `ls /etc/ | grep resolv.conf.dhclient-new`;
  if ($#dhcp_interfaces_resolv_files >= 0) {
    for my $each_file (@dhcp_interfaces_resolv_files) {
       chomp $each_file;
       my $find_search = `grep "^search" /etc/$each_file 2> /dev/null | wc -l`;
       if ($find_search == 1) {
            my $search_string = `grep "^search" /etc/$each_file`;
            my @dhcp_domains = split(/\s+/, $search_string, 2);
            my $dhcp_domain = $dhcp_domains[1];
            chomp $dhcp_domain;
            $doms .= ' ' . $dhcp_domain;
       }
    }
  }
}

my $search = '';
if (length($doms) > 0) {
	$search = "search\t\t$doms\t\t#line generated by $0\n";
}

my $domain = '';
if ($domain_name && length($domain_name) > 0) {
	$domain = "domain\t\t$domain_name\t\t#line generated by $0\n";
}

# update /etc/resolv.conf for name-servers received from dhcp client, only done when dhclient-script calls this script
if ($dhclient_script == 1) {
  my @current_dhcp_nameservers;
  my $restart_ntp = 0;

  # code below to add new name-servers received from dhcp client

  my @dhcp_interfaces_resolv_files = `ls /etc/ | grep resolv.conf.dhclient-new`;
  if ($#dhcp_interfaces_resolv_files >= 0) {
    my $ns_count = 0;
    for my $each_file (@dhcp_interfaces_resolv_files) {
       chomp $each_file;
       my $find_nameserver = `grep nameserver /etc/$each_file 2> /dev/null | wc -l`;
       if ($find_nameserver > 0) {
            my @nameservers = `grep nameserver /etc/$each_file`;
            for my $each_nameserver (@nameservers) {
               my @nameserver = split(/ /, $each_nameserver, 2);
               my $ns = $nameserver[1];
               chomp $ns;
               $current_dhcp_nameservers[$ns_count] = $ns;
               $ns_count++;
               my @search_ns_in_resolvconf = `grep $ns /etc/resolv.conf`;
               my $ns_in_resolvconf = 0;
               if (@search_ns_in_resolvconf > 0) {
                  foreach my $ns_resolvconf (@search_ns_in_resolvconf) {
                       my @resolv_ns = split(/\s+/, $ns_resolvconf);
                       my $final_ns = $resolv_ns[1];
                       chomp $final_ns;
                       if ($final_ns eq $ns) {
                           $ns_in_resolvconf = 1;
                       }
                  }
               }
               if ($ns_in_resolvconf == 0) {
		   open (my $rf, '>>', '/etc/resolv.conf')
		       or die "$! error trying to overwrite";
		   print $rf "nameserver\t$ns\t\t#nameserver written by $0\n";
		   close $rf;
		   $restart_ntp = 1;
               }
            }
       }
    }
  }

  # code below to remove old name-servers from /etc/resolv.conf that were not received in this response from dhcp-server

  my @nameservers_dhcp_in_resolvconf = `grep 'nameserver written' /etc/resolv.conf`;
  my @dhcp_nameservers_in_resolvconf;
  my $count_nameservers_in_resolvconf = 0;
  for my $count_dhcp_nameserver (@nameservers_dhcp_in_resolvconf) {
     my @dhcp_nameserver = split(/\t/, $count_dhcp_nameserver, 3);
     $dhcp_nameservers_in_resolvconf[$count_nameservers_in_resolvconf] = $dhcp_nameserver[1];
     $count_nameservers_in_resolvconf++;
  }
  if ($#current_dhcp_nameservers < 0) {
    for my $dhcpnameserver (@dhcp_nameservers_in_resolvconf) {
        my $cmd = "sed -i '/$dhcpnameserver\t/d' /etc/resolv.conf";
        system($cmd);
        $restart_ntp = 1;
    }
  } else {
         for my $dhcpnameserver (@dhcp_nameservers_in_resolvconf) {
            my $found = 0;
            for my $currentnameserver (@current_dhcp_nameservers) {
               if ($dhcpnameserver eq $currentnameserver){
                  $found = 1;
               }
            }
            if ($found == 0) {
              my $cmd = "sed -i '/$dhcpnameserver\t/d' /etc/resolv.conf";
              system($cmd);
              $restart_ntp = 1;
            }

        }
   }
 if ($restart_ntp == 1) {
     # this corresponds to what is done in name-server/node.def as a fix for bug 1300
     my $cmd_ntp_restart = "if [ -f /etc/ntp.conf ] && grep -q '^server' /etc/ntp.conf; then /usr/sbin/invoke-rc.d ntp restart >&/dev/null; fi &";
     system($cmd_ntp_restart);
 }
}


# The following will re-write '/etc/resolv.conf' line by line,
# replacing the 'search' specifier with the latest values,
# or replacing the 'domain' specifier with the latest value.

my @resolv;
if (-e '/etc/resolv.conf') {
    open (my $f, '<', '/etc/resolv.conf')
	or die("$0:  Error!  Unable to open '/etc/resolv.conf' for input: $!\n");
    @resolv = <$f>;
    close ($f);
}


my $foundSearch = 0;
my $foundDomain = 0;

open (my $r, '>', '/etc/resolv.conf')
    or die("$0:  Error!  Unable to open '/etc/resolv.conf' for output: $!\n");

foreach my $line (@resolv) {
	if ($line =~ /^search\s/) {
		$foundSearch = 1;
		if (length($search) > 0) {
			print $r $search;
		}
	} elsif ($line =~ /^domain\s/) {
		$foundDomain = 1;
		if (length($domain) > 0) {
			print $r $domain;
		}
	} else {
		print $r $line;
	}
}
if ($foundSearch == 0 && length($search) > 0) {
	print $r $search;
}
if ($foundDomain == 0 && length($domain) > 0) {
	print $r $domain;
}

close ($r);